Novel microalgae and their uses
A novel microalgae species within the Cyanidiophyceae family, capable of both haploid and diploid cell morphologies, addresses the limited industrial applications of microalgae by offering a sustainable, nutritionally rich option for outdoor mass cultivation.
Patent Information
- Application Number
- JP2023093900
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- Priority Date
- 2018-09-21
- Filing Date
- 2023-06-07
- Publication Date
- 2025-05-22
- Estimated Expiration
- 2038-11-28
AI Technical Summary
Current industrial applications of microalgae are limited to a few species due to their specific requirements for outdoor mass cultivation, such as tolerance to environmental changes and ability to grow at high densities.
Development of a novel microalgae species belonging to the Cyanidiophyceae family, which can exhibit both haploid and diploid cell morphologies, and can be cultured under conditions where other organisms struggle to survive, thereby expanding the range of microalgae suitable for industrial use.
The novel microalgae species is rich in nutritional components like amino acids and vitamins, and can be mass-cultured outdoors, providing a sustainable source for industrial applications such as feed, functional foods, and cosmetic materials.
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Abstract
Description
[Technical field]
[0001] The present invention relates to a novel microalgae and its use. More specifically, the present invention relates to a novel microalgae and a method for producing the microalgae which are haploid. The present invention also relates to a nutritional component composition and a method for producing a nutritional component. This application claims priority based on Japanese Patent Application Nos. 2017-228394 and 2017-228396, filed in Japan on November 28, 2017, 2018-101753, filed in Japan on May 28, 2018, and 2018-177416, filed in Japan on September 21, 2018, the contents of which are incorporated herein by reference. [Background technology]
[0002] Microalgae have a higher carbon dioxide fixation capacity than terrestrial plants and do not compete with agricultural products for growing habitats. Therefore, some species are mass-cultured and used industrially as feed, functional foods, cosmetic materials, and the like. When microalgae are used industrially, it is desirable to use microalgae that can be mass-cultured outdoors, from the standpoint of cost, etc. However, in order for microalgae to be mass-cultured outdoors, they must be tolerant to environmental changes (light, temperature, etc.), be able to be cultured under conditions in which other organisms cannot survive, and be able to grow to high densities. For this reason, only a few species, such as Chlorella, Euglena, Dunaliella, and Spirulina, have been put into industrial use to date. The above algae species are characterized by their ability to be cultivated in environments where other organisms have difficulty growing, such as high salt concentrations, high pH, and low pH. These algae species are rich in amino acids and vitamins, and are used as raw materials for functional foods and supplements.
[0003] On the other hand, algae belonging to the Cyanidiophyceae, which are unicellular primitive red algae, preferentially grow in sulfuric acid hot springs. The Cyanidiophyceae includes the genera Cyanidioschyzon, Cyanidium, and Galdieria (Non-Patent Document 1), but only Cyanidioschyzon merolae is known as a haploid species (Non-Patent Document 2). Cyanidioschyzon merolae does not have a strong cell wall (Non-Patent Documents 1 and 2). C. melorae is composed of an extremely simple set of organelles, and its genome sequence has been completed. Therefore, it is used as a model organism for basic research on photosynthetic organisms, and genetic engineering techniques are being developed (Non-Patent Documents 3, 4). [Prior art documents] [Non-patent literature]
[0004] [Non-Patent Document 1] Pinto, G. (2007) Cyanidiophyceae: looking back - looking forward, In: J. Seckbach (ed.) Algae and Cyanobacteria in Extreme Environments. Springer, Dordrecht, The Netherlands, pp. 389-397. [Non-Patent Document 2] Misumi O et al. (2005) Cyanidioschyzon merolae Genome. A Tool for Facilitating Comparable Studies on Organelle Biogenesis in Photosynthetic Eukaryotes. Plant Physiol. 137(2): 567-585. [Non-Patent Document 3] Fujiwara T et al. (2013) Gene targeting in the red alga Cyanidioschyzon merolae: single- and multi-copy insertion using authentic and chimeric selection markers. PLOS ONE. Sep 5;8(9):e73608. [Non-Patent Document 4] Fujiwara T et al. (2015) A nitrogen source-dependent inducible and repressible gene expression system in the red alga Cyanidioschyzon merolae. Front Plant Sci. Aug 26;6:657. Summary of the Invention [Problem to be solved by the invention]
[0005] As described above, to date, the microalgae that have been put into industrial use are limited to a few algae species.
[0006] Therefore, an object of the present invention is to provide a novel microalgae that can be used industrially and a method for using the same. Another object of the present invention is to provide a nutritional component composition using microalgae that are rich in nutritional components, and a method for producing nutritional components using the microalgae. Another objective of the present invention is to provide a method for producing haploid cells from diploid algal cells, haploid cells produced by the method, and a population of haploid algal cells obtained by culturing the haploid cells. Another objective of the present invention is to provide a method for producing diploid cells from haploid algal cells, diploid cells produced by the method, and a population of diploid algal cells obtained by culturing the diploid cells. Another objective of the present invention is to provide an algal cell transformed by self-cloning or multiple self-cloning using a haploid algal cell. [Means for solving the problem]
[0007] The present inventors have discovered that among algae belonging to the class Polytrichum, there are some that have a generation with a haploid cell morphology and a generation with a diploid cell morphology, that among algae belonging to the class Polytrichum, those with strong cell walls are diploid cells, and that a method for inducing cells without strong cell walls from diploid cells with strong cell walls is found. Furthermore, the present inventors have found that the cells without strong cell walls obtained by the above method have a haploid cell morphology. Furthermore, the present inventors have found that algae belonging to the class Polytrichum are rich in nutritional components such as amino acids and vitamins. Based on these findings, the present inventors have completed the following invention.
[0008] The present invention includes the following aspects. (1) An algae belonging to the Cyanidiophyceae family, which has a diploid cell morphology and a haploid cell morphology. (1-2) A cell population of an alga according to (1), which is an alga belonging to the Cyanidiophyceae family and is composed of a cell population having a diploid cell morphology. (1-3) A cell population of an alga according to (1), which is an alga belonging to the Cyanidiophyceae family and is composed of a cell population having a haploid cell morphology. (1-4) A cell population of an alga described in (1), which is an alga belonging to the Cyanidiophyceae family and which comprises a mixture of cell populations with diploid cell morphology and cell populations with haploid cell morphology. (2) The algae described in (1), wherein the haploid cell morphology causes the cells to burst under a pH condition of 7. (3) The alga described in (1) or (2), in which the nucleotide sequence of the ribulose 1,5-bisphosphate carboxylase / oxygenase large subunit gene has 90% or more identity with the nucleotide sequence described in SEQ ID NO: 1 or 2. (4) The alga according to (3), which is selected from the group consisting of Cyanidium sp. YFU3 strain (FERM BP-22334), Cyanidium sp. HKN1 strain (FERM BP-22333), and mutant strains thereof. (5) The algae according to any one of (1) to (4), which is a transformant. (6) The algae according to (5), wherein the transformant is produced by self-cloning. (7) The algae according to any one of (1) to (6), wherein the algae has a haploid cell form. (8) A method for producing haploid algae, comprising: (a) a step of culturing cells (algae) having a diploid cell morphology, the cells (algae) being the algae described in any one of (1) to (6); and (b) a step of isolating cells (algae) having a haploid cell morphology produced during the culturing. (9) The culture in the step (a) is carried out at a temperature of 30 to 50° C., at a pH of 1.0 to 5.0, and in a CO 2 The method for producing haploid algae according to claim 8, which is carried out under conditions of a concentration of 1 to 3%. (10) An algal culture comprising the algae according to any one of (1) to (7), wherein the proportion of the number of cells of the algae having a haploid cell morphology to the total number of cells of the algae contained in the algal culture is 70 to 100%. (11) A dried and swollen product obtained by subjecting the algae according to any one of (1) to (7) to a dried and swollen treatment.
[0009] The present invention also includes the following aspects. (12) A method for producing a nutrient component, comprising: (a) a step of destroying cells of the algae described in any one of (1) to (7) to obtain a cell disruptant; and (b) a step of separating the nutrient component from the cell disruptant. (13) The method for producing a nutritional component according to (12), wherein the nutritional component is at least one selected from the group consisting of amino acids, vitamins, proteins, lipids, and dietary fiber. (14) The method for producing a nutritional component according to (13), wherein the amino acid is at least one selected from the group consisting of isoleucine, leucine, lysine, methionine, cystine, phenylalanine, tyrosine, threonine, tryptophan, valine, arginine, histidine, alanine, aspartic acid, glutamic acid, glycine, proline, serine, and γ-aminobutyric acid. (15) The vitamins are vitamin A, β-carotene, vitamin C, vitamin E, and vitamin K. 1 , and Vitamin K 2 The method for producing a nutritional component according to (13), wherein the nutritional component is at least one selected from the group consisting of: (16) The method for producing a nutritional component according to any one of (12) to (15), wherein the disruption of the cells in the step (a) is carried out by at least one treatment selected from the group consisting of a neutralization treatment, a hypotonic treatment, and a freeze-thaw treatment. (17) A method for producing a nutritional component according to any one of (12) to (16), comprising a step of subjecting the algae according to any one of (1) to (7) to a low-temperature treatment at a temperature of 0 to 5°C prior to the step (a). (18) A nutritional composition comprising the algae or an extract thereof according to any one of (1) to (7). (19) A food product comprising the nutritional composition according to (18). (20) The food according to (19), which is a functional food or a nutritional supplement. (21) A feed or pet food comprising the nutritional composition according to (18). (22) A cosmetic comprising the nutritional ingredient composition according to (18). (23) A nutrient comprising the algae or an extract thereof according to any one of (1) to (7). (24) A food product comprising the nutritional supplement described in (23). (25) The food according to (24), which is a functional food or a nutritional supplement. (26) A feed or pet food comprising the nutritional supplement according to (23). (27) A cosmetic comprising the nutritional supplement described in (23). (28) A composition for supplementing nutritional components, comprising the nutrient according to (23). (29) The nutritional composition according to (28), which is a food product. (30) The composition for supplementing nutritional components according to (29), which is a functional food or a nutritional supplement. (31) The nutritional composition according to (28), which is a feed or pet food. (32) The composition for supplementing nutritional ingredients according to (28), which is a cosmetic. (33) A nutritional composition comprising the algae culture or an extract thereof according to (10). (34) A food product comprising the nutritional composition according to (33). (35) The food according to (34), which is a functional food or a nutritional supplement. (36) A feed or pet food comprising the nutritional composition according to (33). (37) A cosmetic comprising the nutritional ingredient composition according to (33). (38) A nutrient comprising the algae culture or an extract thereof according to (10). (39) A food product comprising the nutritional supplement described in (38). (40) The food according to (39), which is a functional food or a nutritional supplement. (41) A feed or pet food comprising the nutritional supplement described in (38). (42) A cosmetic comprising the nutritional supplement described in (38). (43) A composition for supplementing nutritional components, comprising the nutrient according to (38). (44) The nutritional composition according to (43), which is a food product. (45) The composition for supplementing nutritional components according to (44), which is a functional food or a nutritional supplement. (46) The nutritional composition according to (43), which is a feed or pet food. (47) The composition for supplementing nutritional ingredients according to (43), which is a cosmetic. (48) (a) A method for producing a nutrient component, comprising: (a) recovering algae from the algae culture described in (10); (b) disrupting cells of the algae to obtain a cell disruptant; and (c) isolating at least one type of nutrient component from the cell disruptant. (49) The method for producing a nutritional component according to (48), wherein the nutritional component is at least one selected from the group consisting of amino acids, vitamins, proteins, lipids, and dietary fiber. (50) The method for producing a nutritional component according to (49), wherein the amino acid is at least one selected from the group consisting of isoleucine, leucine, lysine, methionine, cystine, phenylalanine, tyrosine, threonine, tryptophan, valine, arginine, histidine, alanine, aspartic acid, glutamic acid, glycine, proline, serine, and γ-aminobutyric acid. (51) The vitamins are vitamin A, β-carotene, vitamin C, vitamin E, and vitamin K. 1 , and Vitamin K 2 The method for producing a nutritional component according to (49), wherein the nutritional component is at least one selected from the group consisting of: (52) The method for producing a nutritional component according to any one of (48) to (51), wherein the disruption of the cells in the step (a) is carried out by at least one treatment selected from the group consisting of a neutralization treatment, a hypotonic treatment, a freeze-thaw treatment, and a dry-swelling treatment.
[0010] The present invention also includes the following aspects. (53) A nutritional composition comprising algae belonging to the Cyanidiophyceae family or an extract thereof. (54) The nutritional composition according to (53), wherein the algae is a haploid algae. (55) The nutritional composition according to (53) or (54), wherein the algae are ones whose cells burst under a pH 7 condition. (56) The nutritional composition according to any one of (53) to (55), wherein the algae are algae belonging to the genus Cyanidioschyzon. (57) The nutritional component composition according to any one of (53) to (56), wherein the algae is a transformant having an increased intracellular content of at least one type of nutritional component. (58) The nutritional composition according to (57), wherein the transformant is produced by self-cloning. (59) The nutritional component composition according to any one of (53) to (58), comprising at least one nutritional component selected from the group consisting of amino acids, vitamins, proteins, lipids, and dietary fibers. (60) A food product comprising the nutritional composition according to any one of (53) to (59). (61) The food according to (60), which is a functional food or a nutritional supplement. (62) A feed or pet food comprising the nutritional composition according to any one of (53) to (59). (63) A cosmetic comprising the nutritional ingredient composition according to any one of (53) to (59). (64) A method for producing a nutritional component, comprising: (a) a step of disrupting cells of an alga belonging to the class Cyanidiophyceae to obtain a cell disruptant; and (b) a step of separating at least one type of nutritional component from the cell disruptant. (65) The method for producing a nutritional component according to (64), wherein the nutritional component is at least one selected from the group consisting of amino acids, vitamins, proteins, lipids, and dietary fiber. (66) The method for producing a nutritional component according to (65), wherein the amino acid is at least one selected from the group consisting of isoleucine, leucine, lysine, methionine, cystine, phenylalanine, tyrosine, threonine, tryptophan, valine, arginine, histidine, alanine, aspartic acid, glutamic acid, glycine, proline, serine, and γ-aminobutyric acid. (67) The vitamins are vitamin A, β-carotene, vitamin B 1 , Vitamin B 2 , Vitamin B 6 , Vitamin C, Vitamin E, Vitamin K 1 , Vitamin K 2, niacin, inositol, folic acid, and biotin. (68) The method for producing a nutritional component according to any one of (64) to (67), wherein the algae is a haploid algae. (69) The method for producing a nutritional component according to any one of (64) to (68), wherein the algae are ones whose cells burst under a pH 7 condition. (70) The method for producing a nutrient component according to any one of (64) to (69), wherein the algae belong to the genus Cyanidioschyzon. (80) The method for producing a nutritional component according to any one of (64) to (70), wherein the algae is a transformant in which the intracellular content of at least one nutritional component is increased. (81) The method for producing a nutritional component according to (80), wherein the transformant is produced by self-cloning. (82) The method for producing a nutritional component according to any one of (64) to (81), wherein the disruption of the cells in the step (a) is carried out by at least one treatment selected from the group consisting of a neutralization treatment, a hypotonic treatment, a freeze-thaw treatment, and a dry-swelling treatment.
[0011] The present invention also includes the following aspects. (83) A nutritional supplement containing algae belonging to the Cyanidiophyceae family or an extract thereof. (84) The nutrient according to (83), wherein the algae is a haploid algae. (85) The nutrient according to (83) or (84), wherein the algae are those whose cells burst under a pH 7 condition. (86) The nutrient according to any one of (83) to (85), wherein the algae are algae belonging to the genus Cyanidioschyzon. (87) The nutrient according to any one of (83) to (86), wherein the algae is a transformant having an increased intracellular content of at least one type of nutrient component. (88) The nutritional supplement according to (87), wherein the transformant is produced by self-cloning. (89) The nutritional supplement according to any one of (83) to (88), which is for supplying at least one nutritional component selected from the group consisting of amino acids, vitamins, proteins, lipids, and dietary fibers. (90) A food comprising the nutritional supplement according to any one of (83) to (89). (91) The food according to (90), which is a functional food or a nutritional supplement. (92) A feed or pet food comprising the nutrient according to any one of (83) to (89). (93) A cosmetic comprising the nutritional supplement according to any one of (83) to (89). (94) A composition for supplementing nutritional components, comprising the nutrient according to any one of (83) to (89). (95) The nutritional composition according to (94), which is a food product. (96) The composition for supplementing nutritional components according to (95), which is a functional food or a nutritional supplement. (97) The nutritional composition according to (94), which is a feed or pet food. (98) The composition for supplementing nutritional ingredients according to (94), which is a cosmetic. (99) The composition for supplementing nutritional components according to any one of (94) to (98), which is for supplementing at least one nutritional component selected from the group consisting of amino acids, vitamins, proteins, lipids, and dietary fibers.
[0012] The present invention also includes the following aspects. (100) (a) A method for producing a diploid alga, comprising the steps of: (a) mixing and culturing two or more types of cells having a haploid cell morphology of the algae described in any one of (1) to (6); and (b) isolating cells having a diploid cell morphology produced during the culturing. (101) The method for producing a diploid alga according to (100), wherein the alga is selected from the group consisting of Cyanidium sp. YFU3 strain (FERM BP-22334), Cyanidium sp. HKN1 strain (FERM BP-22333), and Cyanidioschyzon melorae, and mutants thereof. (102) Cells having a diploid cell morphology of Cyanidium sp. YFU3 strain (FERM BP-22334) or its mutant strain. (103) Cells having a diploid cell morphology of Cyanidium sp. HKN1 strain (FERM BP-22333) or its mutant strain. (104) Diploid cytomorphology of Cyanidioschyzon melorae. (105) The method for producing haploid algae according to (8), wherein the algae is selected from the group consisting of algae belonging to the genus Gardellus and algae belonging to the genus Cyanidium. (106) A cell of haploid morphology from an alga belonging to the genus Galdieria. (107) The cell having a haploid cell morphology according to (106), wherein the algae belonging to the genus Galdieria are Galdieria sulphuraria or Galdieria partita. (108) A cell of haploid morphology of an alga belonging to the genus Cyanidium. (109) The cell having a haploid cell morphology according to (108), wherein the algae belonging to the genus Cyanidium are Cyanidium sp. YFU3 strain (FERM BP-22334) or Cyanidium sp. HKN1 strain (FERM BP-22333). Effect of the Invention
[0013] According to the present invention, there are provided a novel microalgae that can be used industrially and a method for using the same. In addition, according to the present invention, there are provided a nutrient component composition using the microalgae that is rich in nutritional components, and a method for producing nutritional components using the microalgae. The present invention also provides a method for producing haploid cells from diploid algal cells, haploid cells produced by the method, and a population of haploid algal cells obtained by culturing the haploid cells. The present invention also provides a method for producing diploid cells from haploid algal cells, diploid cells produced by the method, and a population of diploid algal cells obtained by culturing the diploid cells. The present invention also provides algal cells transformed by self-cloning or multiple self-cloning using haploid algal cells. [Brief description of the drawings]
[0014] [Figure 1A] 1 shows the construct of the transformation fragment (EGFP / URACm-Cm fragment) used in Example 2. [Figure 1B] The construct of the transformation fragment (GAD / URACm-Cm fragment) used in Example 2 is shown. [Figure 1C] The construct of the transformation fragment (GAD / URACm-Gs fragment) used in Example 2 is shown. [Diagram 2] This shows the results of immunoblotting of the transformants prepared in Example 2. The right panel shows the stained gel after SDS-PAGE, while the left panel shows the results of immunoblotting using an anti-HA antibody. [Diagram 3] 1 shows the results of immunoblotting comparing the GAD / URACm-Cm fragment transformant prepared in Example 2 with the wild-type strain (WT). [Figure 4] 1 shows the results of confirming the copy number of the glutamic acid decarboxylase gene in the GAD / URACm-Gs fragment transformant prepared in Example 2. [Diagram 5] Cyanidioschyzon melorae 10D and Cyanidium caldarium RK-1 were dried and swollen, and the cell suspension after the drying and swelling process was centrifuged. The centrifugal supernatant and centrifugal precipitate were subjected to SDS-polyacrylamide electrophoresis. [Figure 6A] This is a photograph of a microalga (Cyanidium sp. HKN1 strain) isolated from a hot spring in Hakone, Ashigarashimo-gun, Kanagawa Prefecture, Japan. The photograph shows the culture medium of Cyanidium sp. HKN1 strain when it was in the stationary phase after being cultured in MA medium. The arrow indicates Cyanidioschyzon melorae-like cells that appeared during the stationary phase. [Figure 6B] Photographs of microalgae (Cyanidium sp. HKN1 strain) isolated from a hot spring in Hakone, Ashigarashimo-gun, Kanagawa Prefecture, Japan are shown. Cyanidioschyzon melorae-like cells isolated from the stationary-phase culture in Figure 6A are shown. [Figure 7] The results of sequencing of a region of the genome of Cyanidium sp. HKN1 strain and Cyanidioschyzon melorae-like cells isolated from stationary phase cultures of Cyanidium sp. HKN1 strain are shown. It was confirmed that Cyanidioschyzon melorae-like cells are haploids (HKN1 strain (haploid)) resulting from meiosis of Cyanidium sp. HKN1 strain (diploid). [Figure 8] (A) is a micrograph of Galdieria sulphuraria 074, (B) is a micrograph of Cyanidium caldarium RK-1, (C) is a micrograph of Cyanidioschyzon merolae 10D, (D) is a strain YFU3 (haploid), and (E) is a strain HKN1 (haploid). Scale bars represent 5 μm. [Figure 9] The results of agarose electrophoresis comparing the sizes of ribosomal DNA ITS1 in strain YFU3 (haploid), strain HKN1 (haploid), and Cyanidioschyzon melorae are shown. [Figure 10]The molecular phylogenetic tree of the algae belonging to the class Polypodium based on the chloroplast ribulose 1,5-bisphosphate carboxylase / oxygenase large subunit gene is shown. Local bootstrap values by the maximum likelihood method (only values 50 or higher are shown, left) and posterior probabilities by the Bayes method (only values 0.95 or higher are shown, right) are shown near each branch. Known species of Cyanidioschyzon melorae are surrounded by dotted lines, and strains YFU3 and HKN1 are surrounded by solid lines. [Figure 11] 1 shows the chloramphenicol resistance of the chloramphenicol-resistant transformants of the YFU3 strain (haploid) and Cyanidioschyzon melorae 10D prepared in Example 6. [Figure 12] 1 shows the results of PCR confirmation of the insertion of the CAT gene into the genome of the chloramphenicol-resistant transformants of the YFU3 strain (haploid) and Cyanidioschyzon melorae 10D prepared in Example 6. [Figure 13] The construct of the CAT vector for transformation (upper figure: PCR product) and the insertion position into the genome of the HKN1 strain (haploid) (lower figure: Genome) used in Example 7 are shown. In the lower figure (genome), the arrows indicate the positions of the primers used to confirm the insertion of the mVenus-CAT gene in the genome of the chloramphenicol-resistant transformant. [Figure 14] 1 shows the results of confirming insertion of the mVenus-CAT gene in the genome of the chloramphenicol transformant prepared in Example 7 by PCR and agarose gel electrophoresis. [Figure 15] Fluorescence micrographs of the chloramphenicol transformed strain prepared in Example 7 are shown. The left image (mVenus) is a fluorescence micrograph in which mVenus fluorescence was detected, the middle image (Chl) is a fluorescence micrograph in which the autofluorescence of chloroplasts was detected, and the right image (merged) is a merge of the two fluorescence micrographs. [Figure 16] The results of performing a drying and swelling process on algae that do not have strong cell walls and algae that have cell walls, and then centrifuging the cell suspension after the swelling process, and performing SDS-polyacrylamide electrophoresis on the centrifugal supernatant and centrifugal precipitate obtained by centrifugal separation are shown. [Figure 17A] This is a micrograph of diploid-like cells with strong cell walls obtained by crossing HKN1 strains (haploid). [Figure 17B] The results of DAPI staining of diploid-like cells with strong cell walls and the HKN1 strain (haploid) are shown. [Figure 18A] These are micrographs of Galdieria sulphuraria SAG108.79 with normal cell morphology (diploid) (left) and with no strong cell wall (right). [Figure 18B] These are micrographs of Galdieria partita NBRC102759, showing normal cell morphology (diploid) (left) and cell morphology without a strong cell wall (right). [Figure 19] The results of sequence analysis of a region of the genome of Galdieria sulphuraria SAG108.79 in a cell form that does not have a strong cell wall are shown. 2N_allele1 (SEQ ID NO: 61) and 2N_allele2 (SEQ ID NO: 62) respectively show the sequences of each allele of Galdieria sulphuraria SAG108.79 in a normal cell form (diploid). N_clone1, N_clone2, and N_clone3 respectively show the sequences of alleles confirmed in three strains in a cell form that does not have a strong cell wall. [Figure 20] The cell morphology of diploid and haploid Galdieria sulphuraria SAG108.79 and Galdieria partita NBRC102759 was subjected to a drying and swelling treatment, and the cell suspension after the swelling treatment was centrifuged, and the centrifugal supernatant and centrifugal precipitate were subjected to SDS-polyacrylamide electrophoresis. [Figure 21] The construct of the transformation fragment (VE / URACm-Cm fragment) used in Example 12 is shown. [Figure 22]1 shows the results of immunoblotting of the transformants prepared in Example 12. The left panel (TC-HA) shows the results of immunoblotting using an anti-HA antibody, and the right panel (HPT-FLAG) shows the results of immunoblotting using an anti-FLAG antibody. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0015] [Algae belonging to the Cyanidiophyceae family] As shown in the examples described below, algae belonging to the class Cyanidiophyceae have been found to be rich in nutritional components such as amino acids, vitamins, proteins, lipids, and dietary fiber. Therefore, the present invention provides a nutritional component composition, a nutrient, a food, a feed or a pet food, a cosmetic product, and the like, using algae belonging to the class Cyanidiophyceae. The present invention also provides a method for producing nutritional components using algae belonging to the class Cyanidiophyceae.
[0016] Taxonomically, the class Cyanidiophyceae is classified into the division Rhodophyta and the class Cyanidiophyceae. Currently, the class Cyanidiophyceae is classified into three genera: Cyanidioschyzon, Cyanidium, and Galdieria. In the nutritional component composition according to the embodiment of the present invention, algae belonging to any of these genera may be used. Whether or not a certain alga belongs to the class Polypodium can be determined by, for example, phylogenetic analysis using the base sequence of the 18S rRNA gene or the chloroplast rbcL gene. The phylogenetic analysis may be performed by a known method. As used herein, "haploid cell morphology" refers to one set of genetic information in the cells to be observed, and "diploid cell morphology" refers to two sets of genetic information in the cells to be observed. Whether a cell morphology is haploid or diploid can be determined by measuring the DNA content of the cell, but can also be determined by using a next-generation sequencer, which will be described later. As used herein, "having a diploid cell morphology and a haploid cell morphology" means that in the case of algae belonging to the class Polytrichum commune, cells collected from nature may have a haploid cell morphology or a diploid cell morphology, and that in the case of previously unknown algae belonging to the class Polytrichum commune produced by the method of the present invention, there may be cases where the cells have a haploid cell morphology or a diploid cell morphology. As used herein, a "cell population having a diploid cell morphology" and a "cell population having a haploid cell morphology" may be a clonal cell population or a non-clonal cell population.
[0017] Among the algae belonging to the class Polytrichum, Cyanidioschyzon melorae was known to have no strong cell wall. Many algae belonging to the class Polytrichum other than Cyanidioschyzon melorae were found to have algal cells with a cell morphology having a strong cell wall. As shown in the examples described later, these cells with strong cell walls were confirmed to be diploid. However, according to a method according to one embodiment of the present invention described later, algal cells with a haploid cell morphology can be produced, and the produced haploid algal cells often do not have a strong cell wall. Such haploid algal cells without a strong cell wall can be destroyed by relatively mild treatments such as neutralization treatment, hypotonic treatment, and freeze-thaw treatment. In this specification, "does not have a strong cell wall" means that the cells are ruptured by any of the cell rupture treatments (A) to (C) below.
[0018] (A) Algal cells are suspended in an isotonic solution of pH 7 and allowed to stand for at least one week. (B) Algal cells are suspended in distilled water and allowed to stand for at least 1 minute. (C) Algal cells are dried and suspended in an isotonic solution of pH 7. In the above (A) to (C), when the algal cells are cultured cells, before each treatment, the medium may be removed by centrifugation or the like, and the algal cells may be washed with an isotonic solution or the like. In the above (A) and (C), the isotonic solution may be a buffer solution of pH 7 containing 10% sucrose and 20 mM HEPES. In the above (C), the drying treatment may be drying in a refrigerator (4°C), freeze-drying, etc. For the drying treatment, a precipitate of algal cells collected by centrifugation is used. When drying in a refrigerator, the drying treatment time depends on the amount of algal cells, but is, for example, 3 days or more.
[0019] Furthermore, whether or not cell rupture has occurred can be determined by centrifuging the algal cell suspension after the cell rupture treatments (A) to (C) above (1,500×g, 3 minutes) and determining the ratio of the protein amount in the centrifugal supernatant to the total protein amount in the algal cell suspension. Specifically, it can be determined that cell rupture has occurred when the rupture rate calculated by the following formula is 20% or more.
[0020]
number
[0021] Alternatively, the algal cells in the algal cell suspension may be observed under an optical microscope (e.g., 600x magnification), and it may be determined that cell rupture has occurred if the proportion of cells in which rupture has occurred is approximately 10% or more, and preferably approximately 20% or more, of the total algal cells.
[0022] In the above cell rupture treatments (A) to (C), an isotonic solution of pH 7 can be used. Therefore, cells that undergo cell rupture in any of the above cell rupture treatments (A) to (C) can be said to be cells that undergo cell rupture under conditions of pH 7. Not limited to algae belonging to the genus Cyanidioschyzon, any algae whose cells rupture under a pH of 7 is preferred because it is easy to extract nutritional components. In addition, even if the algae cells are mixed as they are in a nutrient solution, etc., which will be described later, there is also an advantage that the nutritional components in the algae cells are easily absorbed after the nutrient solution is ingested. Therefore, in the nutritional component composition of this embodiment, algae belonging to the class Polytrichum and whose cells rupture under a pH of 7 can be preferably used. Whether or not the algae cells will burst under pH 7 conditions can be determined by immersing the algae cells in a pH 7 buffer solution and observing them for about 10 to 30 minutes to confirm whether or not the algae cells burst. If an algal cell does not have a strong cell wall, the cell wall is usually not observed when observed with an optical microscope (eg, at a magnification of 600 times). Cyanidioschyzon melorae does not usually undergo cell rupture even when subjected to mild hypotonic treatment at a pH of less than 6. Therefore, whether or not cell rupture occurs upon mild hypotonic treatment at a pH of less than 6 does not affect the determination of whether or not the alga does not have a strong cell wall.
[0023] Among the algae belonging to the class Polyploidea, the algae belonging to the genus Cyanidioschizon, especially Cyanidioschizon merolae, are characterized by being haploid. They do not have a strong cell wall. Therefore, the algae belonging to the genus Cyanidioschizon, especially Cyanidioschizon merolae, can be transformed relatively easily using recombinant DNA technology. For example, as shown in the examples below, it is also possible to create transformants with increased intracellular content of nutrients using recombinant DNA technology. Not limited to algae belonging to the genus Cyanidioschyzon, particularly Cyanidioschyzon melorae, haploid algae are preferred because they can be transformed relatively easily. For example, algae belonging to the class Polytrichum, which has a diploid cell morphology and a haploid cell morphology as described below, and which have a haploid cell morphology are also preferred because they can be transformed relatively easily. Therefore, in the nutritional component composition and the like according to the embodiment of the present invention, haploid algae belonging to the class Polytrichum can be suitably used. Whether an alga is haploid or not can be determined by checking the copy number of the same gene locus. That is, if the copy number of the same gene locus is 1, it is determined to be haploid. It is also possible to determine whether an alga is haploid, for example, by using a next-generation sequencer. For example, whole genome sequence reads are obtained using a next-generation sequencer, and after assembling these sequence reads, the sequence reads are mapped to the assembled sequence. In a diploid, differences in bases for each allele are found in various regions of the genome, but in a haploid, since there is only one allele, such regions are not found. Also, if the algae is homodiploid, it is possible to determine whether it is haploid or diploid by measuring the DNA content of the cells: the DNA content of a haploid cell is half that of a diploid cell.
[0024] Examples of haploid algae belonging to the class Polytrichum that undergo cell rupture under pH 7 conditions include algae belonging to the genus Cyanidioschyzon. Currently, only one species, Cyanidioschyzon merolae, is classified into the genus Cyanidioschyzon. Therefore, Cyanidioschyzon merolae is a suitable example of algae to be used in the nutrient composition according to the embodiment of the present invention. Furthermore, suitable examples include not only haploid algae belonging to the genus Cyanidioschizon other than the previously unknown Cyanidioschizon melorae obtained by the present invention, but also haploid algae belonging to the genus Gardellus and haploid Cyanidium.
[0025] Algae belonging to the class Polytrichum commune can grow to high densities (approximately 30 g / L) under high temperature (30-55°C) and acidic (pH 0.1-3.0) conditions. Other organisms have difficulty growing in such high temperature and acidic environments, so algae belonging to the class Polytrichum commune are suitable for outdoor mass cultivation. In addition, algae belonging to the class Polytrichum commune can grow under a relatively wide range of environmental conditions, including not only high temperature and acidic conditions, but also mesophilic environments (15-30°C) and neutral environments (pH around 6), etc. Therefore, it is possible to change the culture conditions depending on the region and season, which also makes them suitable for outdoor mass cultivation. Furthermore, it is highly salt tolerant and can grow even under high salt (300 mM NaCl) conditions. The range of light intensities in which it can grow is also wide, from 5 to 1500 μmol / m 2 It can grow at high density in the range of s and can also grow under strong light.
[0026] As shown in the examples below, algae belonging to the class Polytrichum are rich in nutritional components such as amino acids, vitamins, proteins, lipids, and dietary fiber. In particular, it has been confirmed that they contain high concentrations of amino acids and vitamins compared to conventionally used algae (Chlorella, Euglena, Spirulina). In addition, their component composition is also unique. Therefore, by using algae belonging to the class Polytrichum, it is possible to produce a nutritional component composition and a nutritional supplement rich in nutritional components selected from the group consisting of amino acids, vitamins, proteins, lipids, and dietary fiber, particularly nutritional components such as amino acids and vitamins.
[0027] In this specification, the term "amino acids" refers to organic compounds having an amino group and a carboxy group. Examples of amino acids contained in algae belonging to the class Polytrichum commune include isoleucine, leucine, lysine, methionine, cystine, phenylalanine, tyrosine, threonine, tryptophan, valine, arginine, histidine, alanine, aspartic acid, glutamic acid, glycine, proline, serine, γ-aminobutyric acid, etc. Compared with algae that have been conventionally used, algae belonging to the class Polytrichum commune are characterized by a high total amino acid content, and the contents of individual amino acids also tend to be generally high. The total amino acid content of algae belonging to the class Polytrichum is, for example, 60 to 80 g / 100 g dry weight. In addition, algae belonging to the class Polytrichum are also characterized in that they contain γ-aminobutyric acid. The γ-aminobutyric acid content of algae belonging to the class Polytrichum is, for example, 0.1 to 0.3 g / 100 g dry weight. In this specification, the "total amino acid content" refers to the total content of isoleucine, leucine, lysine, methionine, cystine, phenylalanine, tyrosine, threonine, tryptophan, valine, arginine, histidine, alanine, aspartic acid, glutamic acid, glycine, proline, and serine.
[0028] As used herein, the term "vitamins" refers to organic compounds other than carbohydrates, proteins, and lipids, among the nutrients necessary for the survival of living organisms. Vitamins contained in algae belonging to the Polytrichum class include, for example, vitamin A, β-carotene, and vitamin B 1 , Vitamin B 2 , Vitamin B 6 , Vitamin C, Vitamin E, Vitamin K 1 , Vitamin K 2 , niacin, inositol, folic acid, biotin, etc. Among these, algae belonging to the Polytrichum class are richer in β-carotene, vitamin C, vitamin E, vitamin K, etc. than conventionally used algae. 1 , Vitamin K 2 It is characterized by its particularly high content of folic acid. The vitamin content of algae belonging to the Polytrichum commune is, for example, β-carotene content is 200-250 mg / 100 g dry weight, vitamin C content is 40-70 mg / 100 g dry weight, vitamin E content is 150-180 mg / 100 g dry weight, vitamin K content is 100-120 mg / 100 g dry weight, and vitamin C content is 100-120 mg / 100 g dry weight. 1 The content is 3000-5000μg / 100g dry weight, and vitamin K 2 The content of niacin in the diet is, for example, 4000 to 7000 μg / 100 g dry weight, and the content of folic acid is, for example, 3500 to 6500 μg / 100 g dry weight.
[0029] Among algae belonging to the class Polytrichum, those that do not have strong cell walls can efficiently absorb the above-mentioned nutritional components when ingested by humans or non-human animals. Also, when preparing an extract containing nutritional components from algae belonging to the class Polytrichum, those that do not have strong cell walls can be prepared by simple procedures such as the cell rupture treatments (A) to (C) above.
[0030] Algae belonging to the class Polytrichum can be isolated and obtained from sulfuric acid hot springs, etc., because they preferentially grow in sulfuric acid environments such as sulfuric acid hot springs. Alternatively, algae belonging to the class Polytrichum can be obtained from culture collections, etc. For example, Cyanidioschyzon melorae can be obtained from the Microbial Culture Collection of the National Institute for Environmental Studies (16-2 Onogawa, Tsukuba, Ibaraki, Japan), the American Type Culture Collection (ATCC; 10801 University Boulevard Manassas, VA 20110 USA), etc.
[0031] Algae belonging to the class Polytrichum can be cultured using a medium for culturing microalgae. The medium is not particularly limited, but examples thereof include inorganic salt mediums containing nitrogen sources, phosphorus sources, trace elements (zinc, boron, cobalt, copper, manganese, molybdenum, iron, etc.). For example, nitrogen sources include ammonium salts, nitrates, nitrites, etc., and phosphorus sources include phosphates, etc. Examples of such media include 2x Allen medium (Allen MB. Arch. Microbiol. 1959 32: 270-277.), M-Allen medium (Minoda A et al. Plant Cell Physiol. 2004 45: 667-71.), MA2 medium (Ohnuma M et al. Plant Cell Physiol. 2008 Jan;49(1):117-20.), modified M-Allen medium, etc.
[0032] As described above, algae belonging to the class Polytrichum can be grown at high density under a relatively wide range of culture conditions. Examples of pH conditions include pH 1.0 to 6.0, and pH 1.0 to 5.0 is preferred. When culturing outdoors, it is preferred to culture under highly acidic conditions to prevent the growth of other organisms, and examples of such conditions include pH 1.0 to 3.0. The temperature conditions can be, for example, 15 to 50° C., and preferably 30 to 50° C. When culturing outdoors, it is preferable to culture at high temperatures to prevent the proliferation of other organisms, and such conditions can be 35 to 50° C. The light intensity is 5 to 2000 μmol / m 2 Examples of the range are 5 to 1500 μmol / m 2 When culturing outdoors, the cells may be cultured under sunlight. When culturing indoors, the cells may be cultured under continuous light or with a light / dark cycle (e.g., 10L:14D).
[0033] The algae belonging to the class Polytrichum that have been grown by culture can be collected by known methods such as centrifugation or filtration, and then washed, dried, etc. as appropriate, and used in the nutrient of this embodiment.
[0034] In addition, the algae belonging to the class Polytrichum are not limited to those isolated from nature, and may be those in which a mutation has occurred in a natural algae belonging to the class Polytrichum. The mutation may be naturally occurring or artificially occurring. For example, Cyanidioschyzon melorae isolated from nature has a haploid cell form, but has a small genome size (about 16 Mbp) and its genome sequence has been completely deciphered (Matsuzaki M et al., Nature. 2004 Apr 8; 428 (6983): 653-7.), making it easy to perform genetic modification. Therefore, a transformant obtained by genetically modifying Cyanidioschyzon melorae is a suitable example of an algae belonging to the class Polytrichum. In addition, a transformant of an algae belonging to the class Polytrichum may be used in the nutritional component composition according to the embodiment of the present invention as long as it is genetically modifiable, not limited to Cyanidioschyzon melorae. For example, as described below, algae belonging to the genus Gardellina and algae belonging to the genus Cyanidium isolated from nature have a diploid cell morphology with a strong cell wall, but can be made haploid by the method of the present invention, so they have a haploid cell morphology and a diploid cell morphology. Either cell morphology may be used as a cell group. Among the haploid cell morphology cells of these algae, cells that do not have a strong cell wall like Anidioschyzon melorae are easy to genetically modify. Therefore, transformants obtained by genetically modifying cells of the haploid cell morphology or cells that do not have a strong cell wall of algae belonging to the genus Gardellina or Cyanidium are also suitable examples of algae belonging to the class Polypodium. More specifically, in addition to Cyanidioschyzon melorae, it is preferable to use haploids of the genus Gardellina, haploids of the genus Cyanidium, haploids of Cyanidioschyzon other than Cyanidioschyzon melorae, and haploids of Cyanidium. Among these, it is more preferable to use cells that do not have a strong cell wall. Also, diploids belonging to the class Polyploidea, which do not have a strong cell wall, are preferred.
[0035] Transformants of algae belonging to the class Polytrichum are not particularly limited, and examples thereof include transformants in which the intracellular content of at least one nutritional component is increased. Suitable examples of nutritional components whose intracellular content is increased include at least one nutritional component selected from the group consisting of amino acids, vitamins, proteins, lipids, and dietary fiber. In other words, preferred examples of transformants of algae belonging to the class Polytrichum have a higher intracellular content of at least one nutritional component selected from the group consisting of amino acids, vitamins, proteins, lipids, and dietary fiber compared to wild-type strains. In this specification, "wild-type strain" refers to the original cell that was the subject of transformation, but has not been transformed. Among these, at least one nutrient selected from the group consisting of amino acids and vitamins is preferred. Since such a transformant has a higher intracellular content of a specific nutrient than a wild strain, it is possible to prepare a nutrient composition and a nutrient agent rich in the nutrient. The method for increasing the intracellular content of the nutrient is not particularly limited. For example, gene modification may be performed so that the expression level of an enzyme that catalyzes any reaction in the synthetic pathway of the target nutritional component is increased. The method of gene modification to increase the expression level of the enzyme is not particularly limited, and known methods can be used. Examples of such methods include a method of introducing a gene that codes for the enzyme (hereinafter referred to as "enzyme gene"), a method of introducing a gene that codes for a factor that promotes the expression of the enzyme gene, and a method of destroying a gene that codes for a factor that inhibits the expression of the enzyme gene. When an enzyme gene is introduced into an algal cell, a promoter of a gene that is highly expressed in the introduced algal cell may be used instead of the promoter sequence of the enzyme gene. The enzyme is not particularly limited as long as it is an enzyme that catalyzes any reaction in the synthetic pathway of the target nutritional component, and examples of the enzyme include a synthetic enzyme of the target nutritional component, a synthetic enzyme of a precursor of the target nutritional component, and the like. The "precursor of the nutritional component" may be any compound that is generated in the synthetic pathway of the target nutritional component up to the stage before the nutritional component is synthesized.
[0036] A method for increasing the intracellular content of a nutritional component may be, for example, gene modification to reduce the expression level of a factor (hereinafter referred to as "inhibitor") that inhibits any reaction in the synthetic pathway of the target nutritional component. The method for reducing the expression level of an inhibitor is not particularly limited, and known methods can be used. Examples of such methods include a method for disrupting a gene encoding an inhibitor, a method for introducing a gene encoding a factor that suppresses the expression of a gene encoding an inhibitor, a method for disrupting a gene encoding a factor that promotes the expression of a gene encoding an inhibitor, and the like.
[0037] For example, glutamic acid decarboxylase is a synthesizing enzyme of γ-aminobutyric acid. Therefore, by genetically modifying algae belonging to the class Polytrichum commune so that the expression level of the glutamic acid decarboxylase gene is increased, a transformant having an increased intracellular content of γ-aminobutyric acid can be obtained. In addition, homogentisic acid phytyltransferase and tocopherol cyclase are enzymes that catalyze reactions in the biosynthetic pathway of vitamin E. That is, homogentisic acid phytyltransferase is an enzyme that synthesizes 2-methyl-6-phytylbenzoquinone, and tocopherol cyclase is an enzyme that synthesizes γ-tocotrienol. Therefore, by genetically modifying algae belonging to the class Polytrichum commune so that the expression level of either or both of these enzyme genes is increased, a transformant having an increased intracellular content of vitamin E can be obtained. In addition, in order to increase the intracellular content of vitamin E, the expression level of an enzyme that catalyzes another reaction in the biosynthetic pathway of vitamin E may be increased. Similarly, for other nutritional components, the intracellular content of the target nutritional component can be increased by increasing the expression level of an enzyme that catalyzes any reaction in the biosynthetic pathway of the nutritional component (preferably a rate-limiting reaction in the biosynthetic pathway). The sequence information of these synthase genes can be obtained from known sequence databases such as GenBank. The sequence of the glutamic acid decarboxylase gene (CMF072C) of Cyanidioschyzon melorae is shown in SEQ ID NO: 3, and the amino acid sequence is shown in SEQ ID NO: 4. The sequence of the homogentisate phytyltransferase gene (CMN202C) of Cyanidioschyzon melorae is shown in SEQ ID NO: 5, and the amino acid sequence is shown in SEQ ID NO: 6. The sequence of the tocopherol cyclase gene (CML326C) of Cyanidioschyzon melorae is shown in SEQ ID NO: 7, and the amino acid sequence is shown in SEQ ID NO: 8.
[0038] For example, by introducing a gene encoding a synthetic enzyme for a nutritional component (e.g., a glutamic acid decarboxylase gene) into an alga belonging to the class Polytrichum, a transformant having an increased intracellular content of the nutritional component can be obtained. The promoter used for the introduced gene may be the promoter for the synthetic enzyme gene, or may be a promoter for another gene. When a promoter for another gene is used, a promoter for a gene that is highly expressed in the target algal cell is preferred. In the case of Cyanidioschyzon melorae, such promoters include, for example, the promoter for APCC (CMO250C) (e.g., -600 to -1; "-1" indicates the nucleotide immediately before the start codon), the promoter for CPCC (CMP166C), and the promoter for Catalase (CMI050C). The sequence information of these promoters can be obtained from publicly known sequence databases such as GenBank. The promoter sequence of APCC of Cyanidioschyzon merolae is shown in SEQ ID NO: 9, the promoter sequence of CPCC (CMP166C) of Cyanidioschyzon merolae is shown in SEQ ID NO: 10, and the promoter sequence of Catalase (CMI050C) of Cyanidioschyzon merolae is shown in SEQ ID NO: 11.
[0039] Among the algae belonging to the class Polytrichum, Cyanidioschyzon melorae is an algae that can self-clone (Fujiwara et al., PLoS One. 2013 Sep 5;8(9):e73608). Note that "self-cloning" refers to a recombinant gene technology that uses only the following nucleic acids to be introduced into a cell: (1) nucleic acids of an organism belonging to the same taxonomic species as the organism from which the cell is derived, and (2) nucleic acids of an organism belonging to a species that exchanges nucleic acids with the taxonomic species to which the organism from which the cell is derived belongs under natural conditions. Transformants produced by self-cloning are excluded from the scope of genetically modified organisms under the Cartagena Protocol, and therefore can be cultivated outdoors. Therefore, a transformant of an alga belonging to the class Polytrichum by self-cloning is suitable as an algae to be used in the nutrient of this embodiment. Among them, a transformant of Cyanidioschyzon melorae by self-cloning is preferable.
[0040] The method for self-cloning in C. merolae is not particularly limited, but includes a method using the URA5.3 gene (CMK046C) as a selection marker. C. merolae has a uracil auxotrophic mutant, C. merolae M4 (Minoda et al., Plant Cell Physiol. 2004 Jun;45(6):667-71.). C. merolae M4 has a mutation in the URA5.3 gene and cannot synthesize uracil. Therefore, C. merolae M4 cannot grow in a medium that does not contain uracil. Therefore, self-cloning can be performed by using C. merolae M4 as a parent strain and the wild-type URA5.3 gene as a selection marker. More specifically, an arbitrary gene set of Cyanidioschyzon merolae is linked to the URA5.3 gene set of a Cyanidioschyzon merolae wild strain (e.g., 10D strain) and introduced into the Cyanidioschyzon merolae M4 strain. Then, by culturing in a medium not containing uracil, a cell into which an arbitrary gene set has been introduced can be obtained. In the above, the "gene set" means a combination of an arbitrary promoter, an ORF of a target gene, and an arbitrary 3'UTR. The 3'UTR is not particularly limited, and may be the 3'UTR of a target gene or the 3'UTR of another gene. An example of a commonly used 3'UTR is the 3'UTR of β-tubulin. The selection marker is not limited to the URA5.3 gene, and may be a gene related to another auxotrophy.
[0041] When genetic modification is performed using an auxotrophy-related gene as a selection marker as described above, the auxotrophy-related gene introduced into the algal cell can be knocked out, and genetic modification can be performed again using the same auxotrophy-related gene as a selection marker. In other words, multiple self-cloning is possible. There are no particular limitations on the method for knocking out the auxotrophy-related gene introduced as a selection marker, and any known knockout technique may be used. Examples of knockout techniques include homologous recombination and gene editing techniques. For example, as described above, in Cyanidioschyzon merolae, self-cloning can be performed using the URA5.3 gene (CMK046C) as a selection marker and the Cyanidioschyzon merolae M4 strain as a parent strain. Since untransformed cells cannot grow in a medium that does not contain uracil, transformants can be selected by culturing transformed cells in a medium that does not contain uracil. Furthermore, when performing self-cloning, the URA5.3 gene is knocked out by a known knockout technique such as homologous recombination. For example, the entire introduced URA5.3 gene may be deleted, the URA5.3 gene may be partially deleted, or a point mutation may be introduced into the URA5.3 gene. The URA5.3 gene knockout strain can be selected by culturing in a medium containing uracil and 5-fluoroacetic acid (5-FOA). This is because in strains that normally express the URA5.3 gene, uracil and 5-FOA are converted to toxic 5-fluorouracil by the gene product of the URA5.3 gene. If the URA5.3 knockout strain obtained in this way is used as a parent strain, self-cloning can be performed again using the URA5.3 gene as a selection marker. By repeating the same procedure, self-cloning can be performed a desired number of times.
[0042] The method for introducing any nucleic acid into algae belonging to the class Polytrichum commune is not particularly limited, and any known method can be used, such as the polyethylene glycol method, lipofection method, microinjection method, DEAE-dextran method, gene gun method, electroporation method, calcium phosphate method, etc.
[0043] When transforming algae belonging to the class Polytrichum, the introduced nucleic acid may be inserted into any of the nuclear genome, the chloroplast genome, and the mitochondrial genome. When the introduced nucleic acid is inserted into the genome, it may be inserted into a specific position in the genome or may be inserted randomly into the genome. A method for inserting an introduced nucleic acid into a specific position of the genome can be performed by homologous recombination. For example, the entire genome sequence of C. melorae has been completed (Matsuzaki M et al., Nature. 2004 Apr 8;428(6983):653-7.), so it is possible to insert an introduced nucleic acid into a desired position on the genome. The insertion position of an introduced gene in C. melorae is not particularly limited, but an example of the insertion position is the region between CMD184C and CMD185C.
[0044] Preferred specific examples of mutant strains of algae belonging to the class Polytrichum include, but are not limited to, the following (1) to (18). (1) A transformant of an alga belonging to the class Polytrichum, which has a higher intracellular content of at least one nutrient component selected from the group consisting of γ-aminobutyric acid and vitamin E compared to a wild-type strain. (2) A transformant of the algae belonging to the class Polytrichum according to (1), which has a higher expression level of the glutamic acid decarboxylase gene as compared to a wild-type strain. (3) A transformant of the algae belonging to the class Polytrichum according to (2), into which a nucleic acid containing a glutamic acid decarboxylase gene has been introduced in an expressible state. (4) A transformant of algae belonging to the class Polytrichum communes according to (3), wherein the nucleic acid comprises a promoter that functions in cells of algae belonging to the class Polytrichum communes and a glutamic acid decarboxylase gene functionally linked to the promoter. (5) A transformant of algae belonging to the class Polytrichum communes according to (1), which has a higher expression level of at least one gene selected from the group consisting of a homogentisic acid phytyltransferase gene and a tocopherol cyclase gene, as compared to a wild-type strain. (6) A transformant of an alga belonging to the class Polytrichum, described in (5), into which a nucleic acid containing at least one gene selected from the group consisting of a homogentisic acid phytyltransferase gene and a tocopherol cyclase gene has been introduced in an expressible state. (7) A transformant of algae belonging to the class Polytrichum communes described in (6), wherein the nucleic acid comprises a promoter that functions in cells of algae belonging to the class Polytrichum communes and a homogentisic acid phytyltransferase gene functionally linked to the promoter. (8) A transformant of algae belonging to the class Polytrichum communes according to (6) or (7), wherein the nucleic acid comprises a promoter that functions in cells of algae belonging to the class Polytrichum communes and a tocopherol cyclase gene functionally linked to the promoter. (9) A transformant of an alga belonging to the class Polytrichum according to any one of (4), (7), and (8), wherein the promoter is selected from the group consisting of an APCC promoter, a CPCC promoter, and a Catalase promoter. (10) A transformant of an alga belonging to the class Polytrichum according to any one of (3), (4), and (6) to (9), wherein the nucleic acid does not contain a base sequence derived from a cell belonging to a different taxonomic species. (11) The transformant of an alga belonging to the class Polytrichum according to (10), wherein the nucleic acid is introduced into the cell using an auxotrophy-related gene as a selection marker. (12) The transformant of an alga belonging to the class Polytrichum according to (10), wherein the nucleic acid is introduced into a knockout cell of an auxotrophy-related gene using the auxotrophy-related gene as a selection marker. (13) The transformant of algae belonging to the class Polytrichum according to any one of (1) to (12), wherein the algae belonging to the class Polytrichum are algae belonging to the genus Cyanidioschyzon. (14) A transformant of an alga belonging to the class Polytrichum according to (13), wherein the alga is Cyanidioschyzon melorae. (15) The transformant of algae belonging to the class Polytrichum according to (14), wherein the auxotrophic gene is a URA5.3 gene. (16) A transformant of an alga belonging to the class Polytrichum commune according to any one of (1) to (12), wherein the algae belonging to the class Polytrichum commune are cells of a haploid cell morphology of an algae belonging to the genus Garderia. (17) The transformant of algae belonging to the Galdieria class according to (16), wherein the algae belonging to the genus Galdieria are Galdieria sulphuraria or Galdieria partita. (18) A transformant of algae belonging to the class Polytrichum communes according to any one of (1) to (12), wherein the algae belonging to the class Polytrichum communes are cells having a haploid cell morphology of algae belonging to the genus Cyanidium.
[0045] As used herein, "functionally linked" means that a first base sequence is located sufficiently close to a second base sequence so that the first base sequence can affect the second base sequence or a region under the control of the second base sequence. For example, a gene is functionally linked to a promoter means that the gene is linked so as to be expressed under the control of the promoter. "In an expressible state" means that the gene is in a state in which it can be transcribed and translated in a cell into which the gene has been introduced.
[0046] [Extract from algae belonging to the class Polytrichum] The algae extract according to the embodiment of the present invention refers to an extract obtained from one type of algae belonging to the class Polytrichum commune, but may also be an extract obtained from two or more types of algae belonging to the class Polytrichum commune, or may contain a mixture of unbroken Polytrichum commune cells, or may contain a mixture of extracts or cells of algae that do not belong to the class Polytrichum commune. In the nutritional composition according to the embodiment of the present invention, an extract of algae belonging to the Cyanidiophyceae may be used instead of or together with algae belonging to the Cyanidiophyceae. The extract of algae belonging to the Cyanidiophyceae may be rich in nutritional components such as amino acids, vitamins, proteins, lipids, and dietary fiber, similar to algae belonging to the Cyanidiophyceae. Therefore, the present invention also provides a nutritional composition, a nutrient, a food, a feed or a pet food, a cosmetic product, etc., using an extract of algae belonging to the Cyanidiophyceae.
[0047] In this specification, "extract of algae belonging to the class Polytrichum" refers to an extract obtained by subjecting cells of algae belonging to the class Polytrichum to physical or chemical treatment to extract intracellular components. For example, the extract of algae belonging to the class Polytrichum may be a cell disruptant obtained by disrupting cells of algae belonging to the class Polytrichum by physical or chemical treatment. In addition, the extract of algae belonging to the class Polytrichum may be a concentrated cell disruptant, a cell disruptant from which solids have been removed, or a cell disruptant from which some components have been separated.
[0048] The method of physical or chemical treatment of cells is not particularly limited, and any method generally used for cell destruction can be used. Examples of physical treatment include cell destruction using glass beads, a mortar, ultrasonic treatment, a French press, a homogenizer, etc. Examples of the chemical treatment include neutralization treatment, hypotonic treatment, freeze-thaw treatment, dry expansion treatment, etc. More specifically, the above cell rupture treatments (A) to (C) are exemplified. When concentrating the cell disruptant, the concentration method is not particularly limited, and any commonly used concentration method may be used, such as drying, freeze-drying, drying under reduced pressure, etc. When removing solids from the cell disruption product, the method for removing solids is not particularly limited, and any method generally used for removing solids can be used. Examples of the method for removing solids include filtration, centrifugation, etc. When separating a part of the components from the cell disruption product, the separation method is not particularly limited, and a method generally used for the separation and purification of biochemical substances can be used. Examples of the separation method include salting out, dialysis, solvent extraction, adsorption, column chromatography, ion exchange chromatography, etc. These methods may be used alone, or two or more types of treatments may be combined. However, those purified into a single component are excluded from the "extract of algae belonging to the class Polytrichum". The extract of algae belonging to the class Polytrichum preferably contains 10 or more types of cell components of algae belonging to the class Polytrichum, more preferably 15 or more types, and even more preferably 20 or more types. Preferably, the extract of algae belonging to the class Polytrichum contains nutritional components selected from the group consisting of amino acids, vitamins, proteins, lipids, and dietary fibers, and more preferably contains nutritional components selected from the group consisting of amino acids and vitamins. Specific examples of amino acids include isoleucine, leucine, lysine, methionine, cystine, phenylalanine, tyrosine, threonine, tryptophan, valine, arginine, histidine, alanine, aspartic acid, glutamic acid, glycine, proline, serine, γ-aminobutyric acid, etc. Specific examples of vitamins include vitamin A, β-carotene, vitamin B 1 , Vitamin B 2 , Vitamin B 6 , Vitamin C, Vitamin E, Vitamin K 1 , Vitamin K 2 , niacin, inositol, folic acid, biotin, etc.
[0049] [Algae with diploid and haploid cell morphology] In one embodiment, the present invention provides an alga belonging to the Cyanidiophyceae family, the alga having a diploid cell morphology and a haploid cell morphology.
[0050] The algae of this embodiment are characterized by having both a diploid cell morphology and a haploid cell morphology in addition to being an algae belonging to the class Polytrichum. Conventionally, haploid algae belonging to the genus Cyanidioschizon have been known among the algae belonging to the class Polytrichum. However, no algae belonging to the class Polytrichum have been known to have both a diploid cell morphology and a haploid cell morphology. That is, only haploid algae of Cyanidioschizon melorae, which belongs to the genus Cyanidioschizon, which belongs to the class Polytrichum, have been collected from nature, and only diploid algae of the genera Garderia and Cyanidium, which belong to the class Polytrichum, have been collected from nature. The present invention provides algae having a haploid cell morphology produced from cells having a diploid cell morphology of algae belonging to the class Polytrichum, and algae having a diploid cell morphology generated from two or more haploid cells. In this specification, such a situation is expressed as "having both diploid and haploid cell morphology."
[0051] On the other hand, the algae of this embodiment have both diploid and haploid cell morphologies. In the algae of this embodiment, a haploid cell form arises as a result of meiosis of a diploid cell form. It is believed that a diploid cell is generated by the fusion of two haploid cells. Therefore, in the algae of this embodiment, by merging haploid cells having desired traits with each other, a diploid cell having both of those traits can be produced. For example, it is easier to create transformants using recombinant gene technology in haploid cells than in diploid cells, so it is possible to create multiple transformants with desired traits using haploid cells, and then cross-breed the transformants with the desired traits to create a diploid with both traits. The algae of the present embodiment can grow in a cell group consisting of only haploid cells. The algae of the present embodiment can grow in a cell group consisting of only diploid cells. Also, as is clear from the examples described later, it is possible to produce haploid cells from diploid cells and to produce diploid cells from two or more types of haploid cells. In addition, when producing haploid cells from diploid cells or when producing diploid cells from haploid cells, there may be a case where haploid cells and diploid cells are mixed.
[0052] The determination of whether the algae is diploid or haploid can be performed by the method exemplified in the above "[Algae belonging to the class Cyanidiophyceae]". In addition, the determination of whether the algae has both diploid and haploid cell forms can be performed, for example, by the following method. First, the cells with the diploid cell form are cultured until they reach the stationary phase, and when the culture is continued in the stationary phase, it is confirmed whether cells with a form different from that of the diploid cells appear. When cells with a form different from that of the diploid cells appear, those cells are collected and it is confirmed whether the cells are haploid cells. As a result, if the cells are haploid cells, it can be determined that the algae has both diploid and haploid cell forms.
[0053] In the algae of the present embodiment, it is preferable that at least one of the cell forms does not have a strong cell wall. By not having a strong cell wall, the cells can be destroyed by relatively mild treatments such as neutralization treatment, hypotonic treatment, and freeze-thaw treatment. The determination of whether the algae does not have a strong cell wall can be performed by the method described in the above "[Algae belonging to the class Cyanidiophyceae]".
[0054] In the algae of this embodiment, it is preferable that at least one of the diploid and haploid cell forms does not have a strong cell wall, and it is more preferable that the haploid cell form does not have a strong cell wall. In other words, it is preferable that the haploid cell form is one in which the cells are ruptured by any of the cell rupture treatments (A) to (C) above. When a cell does not have a strong cell wall, the cell wall is usually not observed under an optical microscope (for example, at a magnification of 600 times). In the algae of this embodiment, cells of a diploid cell morphology usually have a strong cell wall, but cells of a haploid cell morphology usually do not have a strong cell wall.
[0055] As shown in the examples described below, the algae of this embodiment is rich in nutritional components such as amino acids, vitamins, proteins, lipids, and dietary fiber. In particular, it has been confirmed that the algae contains amino acids and vitamins at higher concentrations than algae that have been used conventionally (Chlorella, Euglena, and Spirulina). Therefore, the algae can be used in the manufacturing method of nutrients and nutritional components described below.
[0056] Examples of amino acids contained in the algae of this embodiment include isoleucine, leucine, lysine, methionine, cystine, phenylalanine, tyrosine, threonine, tryptophan, valine, arginine, histidine, alanine, aspartic acid, glutamic acid, glycine, proline, serine, γ-aminobutyric acid, etc. The algae of this embodiment is characterized by a high total amino acid content compared to conventionally used algae, and the contents of each amino acid also tend to be generally high.
[0057] For example, the total amino acid content in the algae of this embodiment is preferably 50 g / 100 g dry weight or more. The range of the total amino acid content is, for example, 50 to 70 g / 100 g dry weight. In this specification, the "total amino acid content" refers to the total content of isoleucine, leucine, lysine, methionine, cystine, phenylalanine, tyrosine, threonine, tryptophan, valine, arginine, histidine, alanine, aspartic acid, glutamic acid, glycine, proline, and serine. The isoleucine content in the algae of this embodiment is preferably 1.5 g / 100 g dry weight or more, and the range of the isoleucine content is, for example, 1.5 to 5 g / 100 g dry weight. The leucine content in the algae of this embodiment is preferably 4.5 g or more per 100 g dry weight, and the isoleucine content is, for example, in the range of 4.5 to 8 g per 100 g dry weight. The lysine content in the algae of this embodiment is preferably 2.5 g or more per 100 g dry weight, and the lysine content ranges, for example, from 2.5 to 6 g per 100 g dry weight. The methionine content in the algae of the present embodiment is preferably 0.5 g or more per 100 g dry weight, and the range of the methionine content is, for example, 0.5 to 4 g per 100 g dry weight. The cystine content in the algae of this embodiment is preferably 0.5 g / 100 g dry weight or more, and the range of the cystine content is, for example, 0.5 to 3 g / 100 g dry weight. The phenylalanine content in the algae of this embodiment is preferably 1.5 g / 100 g dry weight or more, and the phenylalanine content ranges, for example, from 1.5 to 5 g / 100 g dry weight. The tyrosine content in the algae of this embodiment is preferably 2.0 g or more per 100 g dry weight, and the tyrosine content ranges, for example, from 2.0 to 5 g per 100 g dry weight. The threonine content in the algae of this embodiment is preferably 2.0 g or more per 100 g dry weight, and the threonine content ranges, for example, from 2.0 to 5 g per 100 g dry weight. The tryptophan content in the algae of this embodiment is preferably 0.5 g / 100 g dry weight or more, and the tryptophan content ranges, for example, from 0.5 to 3 g / 100 g dry weight. The valine content in the algae of this embodiment is preferably 2.5 g / 100 g dry weight or more, and the valine content ranges, for example, from 2.5 to 6 g / 100 g dry weight. The arginine content in the algae of this embodiment is preferably 4.5 g or more per 100 g dry weight, and the phenylalanine content is, for example, in the range of 4.5 to 8 g per 100 g dry weight. The histidine content in the algae of this embodiment is preferably 0.5 g / 100 g dry weight or more, and the histidine content ranges, for example, from 0.5 to 3 g / 100 g dry weight. The alanine content in the algae of this embodiment is preferably 3.5 g / 100 g dry weight or more, and the alanine content ranges, for example, from 3.5 to 7 g / 100 g dry weight. The content of aspartic acid in the algae of the present embodiment is preferably 4.5 g / 100 g dry weight or more, and the range of the content of aspartic acid is, for example, 4.5 to 8 g / 100 g dry weight. The glutamic acid content in the algae of this embodiment is preferably 5.5 g / 100 g dry weight or more, and the glutamic acid content ranges, for example, from 5.5 to 9 g / 100 g dry weight. The glycine content in the algae of this embodiment is preferably 2.0 g / 100 g dry weight or more, and the glycine content ranges, for example, from 2.0 to 5.5 g / 100 g dry weight. The proline content in the algae of this embodiment is preferably 1.5 g / 100 g dry weight or more, and the proline content ranges, for example, from 1.5 to 5 g / 100 g dry weight. The serine content in the algae of this embodiment is preferably 2.0 g / 100 g dry weight or more, and the serine content ranges, for example, from 2.0 to 5 g / 100 g dry weight. The content of γ-aminobutyric acid in the algae of this embodiment is preferably 0.05 g / 100 g dry weight or more, and the range of the content of γ-aminobutyric acid is, for example, 0.05 to 0.3 g / 100 g dry weight.
[0058] Examples of vitamins contained in the algae of this embodiment include vitamin A, β-carotene, vitamin C, vitamin E, and vitamin K. 1 , Vitamin K 2 , folic acid, etc. Among these, the algae of the present embodiment are richer in β-carotene, vitamin C, vitamin E, vitamin K, and vitamin D than conventionally used algae. 1 , Vitamin K 2 It is characterized by its particularly high content of folic acid.
[0059] The vitamin A content in the algae of this embodiment is preferably 8 mg / 100 g dry weight or more, and the vitamin A content range is, for example, 8 to 20 mg / 100 g dry weight. The β-carotene content in the algae of this embodiment is preferably 100 mg / 100 g dry weight or more, and the β-carotene content ranges, for example, from 100 to 200 mg / 100 g dry weight. The vitamin C content in the algae of this embodiment is preferably 20 mg / 100 g dry weight or more, and the vitamin C content ranges, for example, from 20 to 50 mg / 100 g dry weight. The content of vitamin E in the algae of this embodiment is preferably 80 mg / 100 g dry weight or more, and the range of the content of vitamin E is, for example, 80 to 150 mg / 100 g dry weight. Vitamin K in the algae of this embodiment 1 The content of vitamin K is preferably 4000 μg / 100 g dry weight or more. 1 The range of the content is, for example, 4000 to 8000 μg / 100 g dry weight. Vitamin K in the algae of this embodiment 2 The content of vitamin K is preferably 1000 μg / 100 g dry weight or more. 2 The range of the content is, for example, 1000 to 3000 μg / 100 g dry weight. The content of folic acid in the algae of this embodiment is preferably 1500 μg / 100 g dry weight or more, and the range of the content of folic acid is, for example, 1500 to 4000 μg / 100 g dry weight.
[0060] The algae of this embodiment can be cultured using a medium for culturing microalgae. The culture can be performed in the same manner as described in “[Algae belonging to the Cyanidiophyceae]” above.
[0061] The algae of this embodiment can also be cultured in a medium using acidic hot spring drainage. "Acidic hot spring drainage" refers to acidic drainage discharged from a hot spring facility. The acidic hot spring drainage is not particularly limited, but is preferably pH 1.0 to 4.0, more preferably pH 1.0 to 3.0. In addition, "a medium using acidic hot spring drainage" refers to a medium prepared by adding a nitrogen source, a phosphorus source, trace elements, and the like to acidic hot spring drainage. As a medium using acidic hot spring drainage, a medium to which a nitrogen source is added to acidic hot spring drainage is preferable, and a medium to which a nitrogen source and a phosphorus source are added is more preferable (for example, see Hirooka S and Miyagishima SY (2016) Cultivation of Acidophilic Algae Galdieria sulphuraria and Pseudochlorella sp. YKT1 in Media Derived from Acidic Hot Springs. Front Microbiol. Dec 20;7:2022.). Examples of the nitrogen source include ammonium salts (ammonium sulfate, etc.), urea, and nitrates (sodium nitrate, etc.), with ammonium salts and urea being preferred, and ammonium salts being more preferred. Examples of the amount of nitrogen source added include 1 to 50 mM in terms of nitrogen addition. Examples of the amount of nitrogen source added include 5 to 40 mM in terms of nitrogen addition, and more preferably 10 to 30 mM in terms of nitrogen addition. Examples of phosphorus sources include phosphates (potassium dihydrogen phosphate, etc.). Examples of the amount of phosphorus source added include 0.1 to 10 mM in terms of phosphorus addition, and the amount of phosphorus source added is preferably 0.5 to 5 mM in terms of phosphorus addition, and more preferably 1 to 3 mM in terms of phosphorus addition. The algae of this embodiment can also be cultured in a medium using acidic hot spring effluent, so that the acidic hot spring effluent can be effectively utilized, and the algae can be cultured at low cost. When the algae of the present embodiment are those belonging to the genus Galderia, the nitrogen source is preferably an ammonia salt or urea, more preferably an ammonia salt.When the algae of the present embodiment are those belonging to the genus Cyanidium, the nitrogen source is preferably an ammonia salt or nitrate, more preferably an ammonia salt.
[0062] (YFU3 strain, HKN1 strain) Specific examples of algae in this embodiment include Cyanidium sp. YFU3 strain (FERM BP-22334) (hereinafter referred to as "YFU3 strain") and Cyanidium sp. HKN1 strain (FERM BP-22333) (hereinafter referred to as "HKN1 strain"), as well as closely related species, mutant strains, and progeny thereof.
[0063] Both the YFU3 strain and the HKN1 strain have diploid and haploid cell morphologies. Hereinafter, when the diploid and haploid cell morphologies of the YFU3 strain are described separately, the diploid cell morphology is described as "YFU3 strain (diploid)" and the haploid cell morphology is described as "YFU3 strain (haploid)". Similarly, when the diploid and haploid cell morphologies of the HKN1 strain are described separately, the diploid cell morphology is described as "HKN1 strain (diploid)" and the haploid cell morphology is described as "HKN1 strain (haploid)". When simply referring to "YFU3 strain" or "HKN1 strain", both the diploid cell morphology and the haploid cell morphology are included.
[0064] The YFU3 strain (haploid) is a unicellular red alga isolated from high-temperature acidic water of a hot spring in Yufu City, Oita Prefecture, Japan. The YFU3 strain was deposited at the National Institute of Technology and Evaluation, Patent Microorganisms Deposit Center (2-5-8 Kazusa Kamatari, Kisarazu City, Chiba Prefecture, Japan) on June 28, 2017 under the accession number FERM P-22334, and transferred to an international deposit on May 23, 2018 under the accession number FERM BP-22334. The HKN1 strain is a unicellular red alga isolated from high-temperature acidic water of a hot spring in Hakone, Ashigarashimo-gun, Kanagawa Prefecture, Japan. The HKN1 strain (haploid) was deposited at the National Institute of Technology and Evaluation (NITE) Patent Microorganism Depositary under the accession number FERM P-22333 on June 28, 2017, and transferred to an international deposit under the accession number FERM BP-22333 on May 23, 2018.
[0065] Both the YFU3 and HKN1 strains have a blue-green color because they contain the blue pigment phycocyanin in addition to chlorophyll a. Both the YFU3 and HKN1 strains grow favorably in high-temperature acidic environments, with an optimum temperature of about 42°C and an optimum pH of around pH 2.
[0066] The cell size of both the YFU3 strain (diploid) and the HKN1 strain (diploid) is about 4 μm. The cell size of both the YFU3 strain (haploid) and the HKN1 strain (haploid) is about 2 μm. The YFU3 strain (diploid) and the HKN1 strain (diploid) have strong cell walls. In other words, cell rupture does not occur under pH 7 conditions. On the other hand, the YFU3 strain (haploid) and the HKN1 strain (haploid) do not have strong cell walls. In other words, cell rupture occurs under pH 7 conditions.
[0067] The cells of strain YFU3 (haploid) and strain HKN1 (haploid) are similar to the cells of Cyanidioschyzon merolae (see Figure 8). Cyanidioschyzon merolae is the only known species of haploid algae that does not have a strong cell wall among the algae belonging to the class Polyploidea. In this specification, cells similar to those of Cyanidioschyzon merolae are sometimes referred to as "Cyanidioschyzon merolae-like cells."
[0068] When the YFU3 strain (diploid) is cultured until it enters the stationary phase and culture is continued while it is in the stationary phase, some of the YFU3 strains (diploid) undergo meiosis, and one cell of the YFU3 strain (diploid) produces four cells of the YFU3 strain (haploid). Similarly, when the HKN1 strain (diploid) is cultured until it enters the stationary phase and culture is continued while it is in the stationary phase, some of the HKN1 strains (diploid) undergo meiosis, and one cell of the HKN1 strain (diploid) produces four cells of the HKN1 strain (haploid). Both the YFU3 strain (haploid) and the HKN1 strain (haploid) can grow by binary fission while maintaining the cell morphology of the haploid.
[0069] Suitable examples of algae of this embodiment include the above-mentioned YFU3 strain and HKN1 strain, as well as algae that are closely related to the YFU3 strain or HKN1 strain and have a diploid cell morphology and a haploid cell morphology. Examples of algae that are closely related to the YFU3 strain and the HKN1 strain include algae whose rbcL gene base sequence has 90% or more identity with the rbcL gene base sequence of the YFU3 strain or the HKN1 strain. The rbcL gene base sequence of the YFU3 strain is shown in SEQ ID NO: 1. The rbcL gene base sequence of the HKN1 strain is shown in SEQ ID NO: 2. Therefore, suitable examples of algae of this embodiment also include algae whose rbcL gene base sequence has 90% or more identity with the rbcL gene base sequence described in SEQ ID NO: 1 or 2. The identity between the base sequence of the rbcL gene possessed by the algae and the base sequence set forth in SEQ ID NO: 1 or 2 is preferably 95% or more, more preferably 97% or more, even more preferably 98% or more, and particularly preferably 99% or more. The base sequence of the rbcL gene of an alga can be obtained by a known method. For example, DNA can be extracted from cells of the target alga by a known method, a DNA fragment of the rbcL gene can be amplified by PCR or the like, and the base sequence of the amplified DNA fragment can be analyzed by a DNA sequencer to obtain the base sequence of the rbcL gene of the target alga. Examples of primers for amplifying the rbcL gene include the primers used in the Examples of this specification.
[0070] Suitable examples of algae of this embodiment include algae that are mutants of the YFU3 or HKN1 strain and have a diploid cell morphology and a haploid cell morphology. In this specification, the term "mutant" refers to an algae strain in which a mutation has occurred naturally or artificially in the genome (including the nuclear genome, chloroplast genome, and mitochondrial genome; the same applies below) of the original algae strain. The artificial method for causing a mutation in the genome is not particularly limited, and examples include chemical treatments such as ultraviolet irradiation, radiation irradiation, and nitrous acid; and genetic engineering methods such as gene introduction and genome editing. In this specification, the term "mutant of the YFU3 strain" refers to an algae strain in which a mutation has occurred in the genome of the YFU3 strain and has a diploid cell morphology and a haploid cell morphology. In addition, the term "mutant of the HKN1 strain" refers to an algae strain in which a mutation has occurred in the genome of the HKN1 strain and has a diploid cell morphology and a haploid cell morphology. For mutant strains of the YFU3 strain, the percentage of mutations relative to the entire genome of the YFU3 strain is preferably 10% or less, more preferably 5% or less, even more preferably 3% or less, and particularly preferably 2% or less or 1% or less. For mutant strains of the HKN1 strain, the proportion of mutations relative to the entire genome of the HKN1 strain is preferably 10% or less of the entire genome, more preferably 5% or less, even more preferably 3% or less, and particularly preferably 2% or less or 1% or less. In the above, the rate of mutation relative to the whole genome is calculated by comparing the whole genomes of diploid cell forms or the whole genomes of haploid cell forms.
[0071] Among the above, closely related species or mutants of the YFU3 strain or HKN1 strain are preferably those having a nutritional composition similar to that of the YFU3 strain or HNK1 strain. For example, the YFU3 strain and the HKN1 strain are characterized by being rich in amino acids and vitamins. Therefore, it is preferable that the amino acid or vitamin content is similar to that of the YFU3 strain and the HKN1 strain. The amino acid and vitamin content may be the content exemplified above.
[0072] Specific examples of mutant strains of YFU3 or HKN1 include transformants genetically modified using genetic engineering techniques. Genetic modification may be performed in either diploid or haploid cell form, but it is easier to perform the genetic modification in haploid cell form. The type of genetic modification is not particularly limited and may be any modification.
[0073] For example, examples of the transformant of the YFU3 strain or the HKN1 strain include a transformant in which the intracellular content of at least one nutritional component is increased. Suitable examples of the nutritional component in which the intracellular content is increased include at least one nutritional component selected from the group consisting of amino acids, vitamins, proteins, lipids, and dietary fiber. That is, preferred examples of the transformant of the YFU3 strain or the HKN1 strain include a transformant in which the intracellular content of at least one nutritional component selected from the group consisting of amino acids, vitamins, proteins, lipids, and dietary fiber is higher than that of the wild strain. Among these, at least one nutrient selected from the group consisting of amino acids and vitamins is preferred. Since such a transformant has a higher intracellular content of a specific nutrient than a wild-type strain, a nutrient rich in the nutrient can be prepared. The method for increasing the intracellular content of a nutritional component is not particularly limited, and any method can be used. For example, the same method as exemplified in the above "Algae belonging to the Cyanidiophyceae" can be used. For example, the intracellular content of any nutritional component can be increased by modifying the YFU3 strain or the HKN1 strain so as to increase the expression amount of any enzyme gene involved in the synthesis of a nutritional component, such as glutamic acid decarboxylase, homogentisic acid phytyltransferase, and tocopherol cyclase.
[0074] The sequence information of these synthetic enzyme genes can be obtained by cloning the target gene by a known method and analyzing the sequence of the cloned target gene. For example, primers may be designed based on the sequence information of a known homologous gene possessed by algae belonging to the class Polytrichum, and an amplified fragment of the target gene may be obtained by PCR or the like using the genome of the YFU3 or HKN1 strain as a template. Alternatively, a probe may be designed based on the sequence information of a known homologous gene possessed by algae belonging to the class Polytrichum, and a cDNA library of the YFU3 or HKN1 strain may be screened. In addition, genes from other organisms may be used as the introduced gene as long as they function in the introduced cell. For example, known genes from algae belonging to the class Polytrichum may be used. Sequence information of known genes can be obtained from known sequence databases such as GenBank. For example, the glutamic acid decarboxylase gene (CMF072C), homogentisic acid phytyltransferase gene (CMN202C), and tocopherol cyclase gene (CML326C) of Cyanidioschyzon melorae can be used.
[0075] For example, by introducing a synthetic enzyme gene of a nutritional component (e.g., glutamic acid decarboxylase gene) into the YFU3 strain or HKN1 strain, a transformant with an increased intracellular content of the nutritional component can be obtained. The promoter used for the introduced gene may be the promoter of the synthetic enzyme gene, or may be the promoter of another gene. When using a promoter of another gene, a promoter of a gene that is highly expressed in the algal cell to which the promoter is introduced is preferable. Examples of such promoters include the APCC (CMO250C) promoter, the CPCC (CMP166C) promoter, and the Catalase (CMI050C) promoter. As long as the promoter functions in the introduced cell, it may be derived from an organism of the same species as the introduced cell, or from an organism of another species. When a promoter of a known gene is used, its sequence information can be obtained from a known sequence database such as GenBank.
[0076] The transformants of the YFU3 or HKN1 strain may be those into which any nucleic acid has been introduced, but it is more preferable that they are prepared by self-cloning. For example, a self-cloning method has been established for Cyanidioschyzon melorae, an algae belonging to the class Polypodium (Fujiwara et al., PLoS One. 2013 Sep 5;8(9):e73608). Therefore, self-cloning can be performed for the YFU3 or HKN1 strain by the same method as for Cyanidioschyzon melorae.
[0077] The method for self-cloning is not particularly limited, but includes a method using an auxotrophic mutant. For example, in Cyanidioschyzon melorae, a method using the URA5.3 gene (CMK046C) as a selection marker has been proposed (see "Algae belonging to the Cyanidiophyceae" above).
[0078] In the YFU3 strain and the HKN1 strain, a gene related to auxotrophy can be knocked out by a known gene knockout technique or the like to prepare an auxotrophic mutant, and then self-cloning can be performed using the gene to be knocked out as a selection marker. The knockout technique is not particularly limited, and any known method may be used. Examples of the knockout technique include homologous recombination and gene editing techniques. The gene to be knocked out is not particularly limited as long as the auxotrophy is changed by knocking out the gene. Examples of the gene to be knocked out include orotidine-5'-decarboxylase.
[0079] Furthermore, when genetic modification is performed using an auxotrophy-related gene as a selection marker as described above, by knocking out the auxotrophy-related gene introduced into the algal cell, genetic modification can be performed again using the same auxotrophy-related gene as a selection marker. In other words, multiple self-cloning is possible. There are no particular limitations on the method for knocking out the auxotrophy-related gene introduced as a selection marker, and any known knockout technique may be used. Examples of knockout techniques include homologous recombination and gene editing techniques. For example, as described above, in Cyanidioschyzon merolae, self-cloning can be performed using the URA5.3 gene (CMK046C) as a selection marker and the Cyanidioschyzon merolae M4 strain as a parent strain. If a URA5.3 gene knockout strain is prepared for the YFU3 and HKN1 strains, the knockout strain cannot grow in a medium that does not contain uracil. The URA5.3 gene is introduced into the parent strain to transform it, and the transformed cell is cultured in a medium that does not contain uracil, whereby a transformant can be selected. Furthermore, when self-cloning is performed, the URA5.3 gene is knocked out again by a known knockout technique such as homologous recombination. The re-knockout strain of the URA5.3 gene can be selected by culturing it in a medium containing uracil and 5-fluoroacetic acid (5-FOA). This is because in a strain that normally expresses the URA5.3 gene, uracil and 5-FOA are converted to toxic 5-fluorouracil by the gene product of the URA5.3 gene. If the URA5.3 re-knockout strain thus obtained is used as a parent strain, self-cloning can be performed again using the URA5.3 gene as a selection marker. By repeating the same operation, it is possible to perform self-cloning a desired number of times. The knockout of the URA5.3 gene may be performed by deleting the entire URA5.3 gene, by partially deleting the URA5.3 gene, or by introducing a point mutation into the URA5.3 gene.
[0080] The method for introducing any nucleic acid into the YFU3 or HKN1 strain is not particularly limited, and any known method can be used, such as the polyethylene glycol method, lipofection method, microinjection method, DEAE-dextran method, gene gun method, electroporation method, calcium phosphate method, etc.
[0081] When transforming the YFU3 or HKN1 strain, the introduced nucleic acid may be inserted into any of the nuclear genome, the chloroplast genome, and the mitochondrial genome. When the introduced nucleic acid is inserted into the genome, it may be inserted into a specific position of the genome, or may be inserted randomly into the genome. As a method for inserting the introduced nucleic acid into a specific position of the genome, homologous recombination can be used.
[0082] An example of a method for transforming the YFU3 or HKN1 strain is shown below, but the method is not limited thereto. First, the YFU3 strain or the HKN1 strain is diluted to an appropriate concentration in an appropriate medium such as MA2U medium (see Example 7), and cultured under appropriate culture conditions (e.g., light / dark cycle 12L:12D, light 50 μmol / m 2 The cells are cultured at 42°C (95°C for 10 min) for about 40 to 80 hours with aeration. Next, Tween-20 is added to the culture solution to a final concentration of 0.002%, and the cells are then collected by centrifugation and suspended in an appropriate medium such as MA2U medium. The cells are dissolved in 450 μL of MA2U medium containing PEG4000 (95°C, 10 min) to prepare a 60% (w / v) PEG4000 solution. The PEG4000 solution was then maintained at 42°C on a heat block until use. A cell suspension of the YFU3 or HKN1 strain is added to a transformation mixture containing a transformation vector containing an appropriate selection marker and polyethylene glycol (e.g., PEG4000), and the mixture is stirred. The cells are then transferred to an appropriate medium such as MA2U medium and grown under appropriate culture conditions (e.g., continuous light, 20 μmol / m 2s) and a temperature of 42°C) for about 40 to 60 hours. Thereafter, the cells are collected by centrifugation and suspended in an appropriate medium such as Tsukahara mineral spring medium (Hirooka et al. 2016 Front in Microbiology) or modified MA medium (see Example 7). The cell suspension is added to a selection medium according to the selection marker used (e.g., Tsukahara mineral spring medium or modified MA medium to which a specific substance has been added, or the medium or the like from which a specific substance has been removed), and the cells are cultured under appropriate culture conditions (e.g., continuous light, 20 μmol / m 2 s, temperature 42℃, 3%CO 2 ) and culture statically for about 5 to 10 days. The culture fluid from the dark green part is collected and added to new selective medium, and cultured statically for another 5 to 10 days to select transformants. The transformants can be isolated one by one using a Pasteur pipette with a fine tip under an inverted microscope, and cultured statically in an appropriate medium such as Tsukahara mineral spring medium or modified MA medium to obtain transformed strains. Although the polyethylene glycol method has been described as an example of transformation, other transformation methods such as lipofection, microinjection, DEAE-dextran, gene gun, electroporation, and calcium phosphate may also be used.
[0083] Preferred specific examples of mutant strains of the YFU3 or HKN1 strain include, but are not limited to, the following (1) to (18). (1) A transformant of the YFU3 or HKN1 strain, which has a higher intracellular content of at least one nutritional component selected from the group consisting of γ-aminobutyric acid and vitamin E compared to a wild-type strain. (2) A transformant of the YFU3 strain or the HKN1 strain according to (1), which has a higher expression level of the glutamic acid decarboxylase gene as compared to a wild-type strain. (3) A transformant of the YFU3 or HKN1 strain described in (2), into which a nucleic acid containing a glutamic acid decarboxylase gene has been introduced in an expressible state. (4) A transformant of the YFU3 or HKN1 strain described in (3), wherein the nucleic acid comprises a promoter that functions in cells of an alga belonging to the Polytrichum class and a glutamic acid decarboxylase gene operably linked to the promoter. (5) A transformant of the YFU3 or HKN1 strain according to (1), which has a higher expression level of at least one gene selected from the group consisting of a homogentisic acid phytyltransferase gene and a tocopherol cyclase gene, as compared to a wild-type strain. (6) A transformant of the YFU3 or HKN1 strain according to (5), into which a nucleic acid containing at least one gene selected from the group consisting of a homogentisic acid phytyltransferase gene and a tocopherol cyclase gene has been introduced in an expressible state. (7) A transformant of the YFU3 or HKN1 strain described in (6), wherein the nucleic acid comprises a promoter that functions in cells of an alga belonging to the Polytrichum class and a homogentisic acid phytyltransferase gene operably linked to the promoter. (8) A transformant of the YFU3 or HKN1 strain described in (6) or (7), wherein the nucleic acid comprises a promoter that functions in cells of an alga belonging to the Polytrichum class and a tocopherol cyclase gene functionally linked to the promoter. (9) The transformant of the YFU3 strain or the HKN1 strain according to any one of (4), (7), and (8), wherein the promoter is selected from the group consisting of an APCC promoter, a CPCC promoter, and a Catalase promoter. (10) The transformant of the YFU3 strain or the HKN1 strain according to any one of (3), (4), and (6) to (9), wherein the nucleic acid does not contain a base sequence derived from a cell belonging to a different taxonomic species. (11) The transformant of an alga belonging to the class Polytrichum according to (10), wherein the nucleic acid is introduced into the cell using an auxotrophy-related gene as a selection marker. (12) The transformant of the YFU3 strain or the HKN1 strain according to (10), wherein the nucleic acid is introduced into a knockout cell of an auxotrophy-related gene, using the auxotrophy-related gene as a selection marker. (13) A transformant of the YFU3 or HKN1 strain described in any one of (3), (4), and (9), wherein the glutamic acid decarboxylase gene is a glutamic acid decarboxylase gene of Cyanidioschyzon melorae. (14) A transformant of the YFU3 or HKN1 strain described in any one of (6), (7), and (9), wherein the homogentisic acid phytyltransferase gene is a homogentisic acid phytyltransferase gene of Cyanidioschyzon melorae. (15) A transformant of the YFU3 or HKN1 strain described in any one of (6), (8), and (9), wherein the tocopherol cyclase gene is a tocopherol cyclase gene of Cyanidioschyzon melorae. (16) The transformant of the YFU3 strain or the HKN1 strain according to any one of (4) and (7) to (9), wherein the promoter is a promoter derived from Cyanidioschyzon melorae. (17) A transformant of the YFU3 strain or the HKN1 strain according to any one of (1) to (16), which is a cell having a haploid cell morphology. (18) A transformant of the YFU3 strain or the HKN1 strain according to any one of (1) to (16), which is a cell having a diploid cell morphology.
[0084] Furthermore, as shown in the examples described below, it has been confirmed that algae belonging to the genus Galderia also have a haploid cell morphology and a diploid cell morphology. Therefore, the algae of this embodiment may be algae belonging to the genus Galderia. Examples of algae belonging to the genus Galderia include Galdieria sulphuraria (e.g., SAG108.79 strain) and Galdieria partita (e.g., NBRC 102759 strain). Furthermore, the algae of this embodiment may be algae belonging to the genus Cyanidium other than the above-mentioned YFU3 strain and HKN1 strain.
[0085] [Method for producing haploid algae] The present invention provides a method for producing algae with a haploid cell morphology, the method comprising: (a) a step of culturing cells of a diploid cell morphology of algae belonging to the class Polytrichum commune, the algae having a diploid cell morphology and a haploid cell morphology; and (b) a step of isolating cells of the haploid cell morphology produced during the culturing.
[0086] Algae belonging to the class Polytrichum commune and having a diploid cell morphology and a haploid cell morphology (hereinafter, sometimes referred to as "this algae") are similar to the algae described above in "[Algae having a diploid cell morphology and a haploid cell morphology]." Preferred examples of this algae include the YFU3 and HKN1 strains, as well as mutants or related strains thereof. In addition, as shown in the examples described later, algae belonging to the genus Galderia (Galdieria sulphuraria SAG108.79 and Galdieria partita NBRC 102759) were also confirmed to have a diploid cell morphology and a haploid cell morphology. This result suggests that algae having a diploid cell morphology and a haploid cell morphology may be widely present in the class Polytrichum (e.g., Galderia and Cyanidium). Therefore, the algae to which the manufacturing method of this embodiment can be applied may be algae belonging to the genus Galderia or Cyanidium, and are not limited to the above-mentioned examples. Specific examples of algae belonging to the genus Galderia include, for example, Galdieria sulphuraria and Galdieria partita. According to the production method of this embodiment, algae having a haploid cell morphology can be produced from a diploid cell morphology. Transformation of haploid algae is easier than that of diploid algae.
[0087] (Step (a)) Step (a) is a step of culturing cells of a diploid cell morphology of an alga (Meloeophyceae) belonging to the class Polyploidea, which has both a diploid cell morphology and a haploid cell morphology.
[0088] The present algae is not particularly limited, and may be any algae belonging to the class Polypodiaceae that has been confirmed to have both diploid and haploid cell morphologies. Specific examples include the YFU3 strain (diploid) and the HKN1 strain (diploid), as well as related species and mutant strains thereof. Other examples include the diploid cell morphology of algae belonging to the genus Galdieria (Galdieria sulphuraria, Galdieria partita, etc.), and the diploid cell morphology of algae belonging to the genus Cyanidium.
[0089] Examples of the culture conditions include those listed in the above "Algae belonging to the Cyanidiophyceae" or "Algae having both diploid and haploid cell forms". Specifically, examples of pH conditions include pH 1.0 to 6.0, with pH 1.0 to 5.0 being preferred. Examples of temperature conditions include 15 to 50°C, with 30 to 50°C being preferred. Examples of the medium include those listed in the above "Algae belonging to the Cyanidiophyceae" or "Algae having both diploid and haploid cell forms", with a medium using acidic hot spring effluent being preferred. A specific example of a medium using acidic hot spring effluent is Tsukahara mineral spring medium (Hirooka et al. 2016 Front in Microbiology).
[0090] The culture is preferably carried out until the algae of the above embodiment reach the stationary phase, and more preferably, the culture is continued for an arbitrary period while the algae are in the stationary phase. Examples of the culture period include 2 to 60 days, 3 to 40 days, or 5 to 35 days. The period from the start of culture until the algae reach the stationary phase differs depending on the type of algae, and therefore the culture period can be set according to the type of algae. Furthermore, cells may be recovered from the culture medium in the stationary phase, subcultured, and further cultured for about 1 to 5 days.
[0091] (Step (b)) Step (b) is a step of isolating cells having a haploid cell morphology that arise during the culture.
[0092] By culturing in step (a), the present algae with a diploid cell morphology undergo meiosis to produce the present algae with a haploid cell morphology. When observed under an optical microscope, cells with a haploid cell morphology have a different cell shape from cells with a diploid cell morphology (for example, they are smaller in cell size than cells with a diploid cell morphology, and strong cell walls are not observed). Therefore, cells with a haploid cell morphology can be distinguished based on the difference in cell shape. By collecting and isolating the cells with a haploid cell morphology using a Pasteur pipette or the like, it is possible to produce algae with a haploid cell morphology. The isolated algae with haploid cell morphology may be cultured using a medium or the like listed above under "Algae belonging to the Cyanidiophyceae" or "Algae having both diploid and haploid cell morphology." The haploid cells that appear in the culture medium of the cells with diploid cell morphology can be isolated one by one and grown individually to obtain single-clone algae with haploid cell morphology.
[0093] In another aspect, the present invention provides algae (cells) that are haploid cellular forms of algae (Mesophyceae) that belong to the class Polypodiaceae and have a diploid cellular form and a haploid cellular form. The algae can be obtained by the above-mentioned method for producing haploid algae. The present invention also provides algae (cells) that are haploid cellular forms of the YFU3 strain, algae (cells) that are haploid cellular forms of the HKN1 strain, algae (cells) that are haploid cellular forms of algae belonging to the genus Cyanidium, and algae (cells) that are haploid cellular forms of algae belonging to the genus Galderia. Specific examples of algae belonging to the genus Galderia include Galdieria sulphuraria and Galdieria partita.
[0094] [Method for producing diploid algae] The present invention provides a method for producing haploid algae, which is an alga having a diploid cell form and a haploid cell form, and includes: (a) a step of mixing and culturing cells of two or more haploid cell forms; and (b) a step of isolating cells of the diploid cell form generated during the culturing.
[0095] As shown in the examples described below, cells of the diploid cell form can be obtained by mixing and culturing cells of the haploid cell form.
[0096] (Step (a)) Step (a) is a step of mixing and culturing cells of two or more haploid cell forms in an alga having a diploid cell form and a haploid cell form.
[0097] The cells of two or more haploid cell forms to be mixed in this step are preferably cells of the same species of alga. More preferably, cells of the haploid cell form derived from cells of the diploid cell form of the same strain are used.
[0098] As the culture conditions, the culture conditions listed in the above "[Algae belonging to the class Cyanidiophyceae]" or "[Algae having a diploid cell form and a haploid cell form]" can be mentioned. Specifically, as the pH conditions, pH 1.0 to 6.0 can be exemplified, and pH 1.0 to 5.0 is preferable. Also, as the temperature conditions, 15 to 50 °C can be exemplified, and 30 to 50 °C is preferable. The culture medium is exemplified by the culture media listed in the above "[Algae belonging to the class Cyanidiophyceae]" or "[Algae having a diploid cell form and a haploid cell form]".
[0099] The culturing is preferably carried out for about 1 to 4 weeks, for example, and further subculturing may be performed and the culturing may be carried out for about 3 to 10 days.
[0100] (Step (b)) Step (b) is a step of isolating cells of the diploid cell form generated during the culturing.
[0101] By culturing in step (a), cells with haploid morphology mate with each other to produce cells with diploid morphology. The cells with diploid morphology can be harvested and isolated using a Pasteur pipette or the like to produce diploid algae. The isolated diploid algae may be cultured using a medium such as those listed above under "Algae belonging to the Cyanidiophyceae family" or "Algae having both diploid and haploid cell morphologies" (preferably an artificial synthetic medium such as M-Allen medium).
[0102] In another aspect, the present invention provides an alga (cell) that is a diploid cell form of an alga (Melophyceae) belonging to the class Polypodiaceae and has a diploid cell form and a haploid cell form. The alga can be obtained by the above-mentioned method for producing diploid algae. The present invention also provides an alga (cell) that is a diploid cell form of the YFU3 strain, an alga (cell) that is a diploid cell form of the HKN1 strain, and an alga (cell) that is a haploid cell form of an alga belonging to the genus Cyanidioschyzon. A specific example of an alga belonging to the genus Cyanidioschyzon is Cyanidioschyzon merolae.
[0103] [Culture of this algae] The present invention provides an algae culture containing algae (this alga) belonging to the class Polypodiaceae, which have a diploid cell morphology and a haploid cell morphology. In the algae culture of this embodiment, the ratio of the number of algae cells having a haploid cell morphology to the total number of algae cells is 70 to 100%.
[0104] It is assumed that in nature, this algae exists in a mixture of diploid and haploid cell forms; however, since the known algae belonging to the genera Gardellina and Cyanidium have both been found to have cells with strong cell walls, it is believed that in nature, most of them exist in a diploid cell form. On the other hand, according to the method for producing haploid algae according to the above embodiment, the diploid algae undergo meiosis when the algae reach the stationary phase, and when the culture is continued, the diploid algae undergo meiosis, and haploid algae appear. The haploid algae grow by binary fission, and when the culture is continued, the proportion of haploid algae increases. Then, by continuing the culture or isolating and culturing the haploid algae, an algae culture containing 70 to 100% haploid algae can be obtained.
[0105] The present algae is not particularly limited, and it is sufficient to culture the diploid cell form of an algae belonging to the class Polytrichum that has been confirmed to have a diploid cell form and a haploid cell form. Specific examples include the YFU3 strain (diploid) and the HKN1 strain (diploid), as well as related species and mutant strains thereof. Other examples include the diploid cell form of algae belonging to the genus Galderia (Galdieria sulphuraria, Galdieria partita, etc.), and the diploid cell form of algae belonging to the genus Cyanidium. Culture conditions for this algae with a diploid cell morphology include the same conditions as those listed above under "[Algae belonging to the Cyanidiophyceae family]" or "[Algae having both diploid and haploid cell morphologies]".
[0106] In the algae culture of this embodiment, haploid cell forms account for 70 to 100%, which is significantly different from the proportion of haploid cell forms found in nature.
[0107] In another aspect, the present invention provides a cell population consisting of cells of diploid cell morphology of an alga belonging to the class Cyanidiophyceae, the alga having a diploid cell morphology and a haploid cell morphology. Preferred examples of the algae belonging to the class Cyanidiophyceae include the YFU3 strain, the HKN1 strain, and mutant strains thereof, and algae belonging to the genus Cyanidioschizon. Examples of the algae belonging to the genus Cyanidioschizon include Cyanidioschizon merolae. In another aspect, the present invention provides a cell group consisting of cells in the haploid cell form of an alga belonging to the class Cyanidiophyceae, which has a diploid cell form and a haploid cell form. Preferred examples of the alga belonging to the class Cyanidiophyceae include the YFU3 strain, the HKN1 strain, and mutants thereof, as well as algae belonging to the genus Cyanidium other than those described above and algae belonging to the genus Galdieria. Examples of the alga belonging to the genus Galdieria include Galdieria sulphuraria and Galdieria partita. In another aspect, the present invention provides a cell group in which cells in the diploid cell form and cells in the haploid cell form of an alga belonging to the class Cyanidiophyceae, which has a diploid cell form and a haploid cell form, are mixed.
[0108] [Dried and swollen treated product of this alga] The present invention provides a dried and swollen treated product obtained by subjecting an alga belonging to the class Cyanidiophyceae, which has a diploid cell form and a haploid cell form (this alga), to a drying and swelling treatment.
[0109] By subjecting this alga to a drying and swelling treatment, algal cells can be killed. Therefore, even a transformant not relying on self-cloning can be handled in an open system. Note that the "drying and swelling treatment" means drying algal cells and then adding an aqueous medium or the like to the dried product to moisten it again. Specific examples of the drying and swelling treatment include, for example, the cell disruption treatment in (3) above. The alga to be subjected to the drying and swelling treatment may be in the diploid cell form, may be in the haploid cell form, or may be a mixture of the diploid cell form and the haploid cell form. For example, it may be cells recovered from the algal culture of the above embodiment. The ploidy-changing type alga to be subjected to the drying and swelling treatment is preferably in the haploid cell form.
[0110] [Extract of this alga] As described above, the present algae are rich in nutritional components such as amino acids, vitamins, proteins, lipids, and dietary fiber, and therefore can be used as a nutritional component composition or a nutritional agent, as described below. In addition, by blending the present algae with food, feed, pet food, cosmetics, and the like, products with enhanced nutritional components can be provided. In addition, in such products, an extract of the present algae may be used instead of or in addition to the present algae. Therefore, the present invention also provides an extract of the present algae.
[0111] As used herein, the term "extract of this alga" refers to a product obtained by subjecting cells of this algae to physical or chemical treatment to extract intracellular components. For example, the extract of this algae may be a cell disruptant obtained by disrupting cells of this algae by physical or chemical treatment. In addition, the extract of this algae may be a concentrated product of the cell disruptant, a product of removing solids from the cell disruptant, or a product of separating some components from the cell disruptant.
[0112] The method of physical or chemical treatment of cells is not particularly limited, and any method generally used for cell destruction can be used. Examples of physical treatment include cell destruction using glass beads, a mortar, ultrasonic treatment, a French press, a homogenizer, etc. Examples of the chemical treatment include neutralization treatment, hypotonic treatment, freeze-thaw treatment, dry swelling treatment, etc. More specifically, the above cell rupture treatments (A) to (C) are exemplified. When concentrating the cell disruptant, the concentration method is not particularly limited, and any commonly used concentration method may be used, such as drying, freeze-drying, drying under reduced pressure, etc. In addition, when removing solids from the cell disruption product, the method for removing solids is not particularly limited, and a method generally used for removing solids can be used. Examples of the method for removing solids include filtration and centrifugation. When separating some components from the cell disruption product, the separation method is not particularly limited, and a method generally used for the separation and purification of biochemical substances can be used. Examples of separation methods include salting out, dialysis, solvent extraction, adsorption, column chromatography, ion exchange chromatography, and the like. These methods may be used alone, or two or more types of treatments may be combined. However, those purified into a single component are excluded from the "extract of this alga". The extract of this alga preferably contains 10 or more types of cellular components of this alga, more preferably 15 or more types, and even more preferably 20 or more types. Preferably, the extract of the present algae contains nutritional components selected from the group consisting of amino acids, vitamins, proteins, lipids, and dietary fibers, and more preferably contains nutritional components selected from the group consisting of amino acids and vitamins. Specific examples of amino acids include isoleucine, leucine, lysine, methionine, cystine, phenylalanine, tyrosine, threonine, tryptophan, valine, arginine, histidine, alanine, aspartic acid, glutamic acid, glycine, proline, serine, and γ-aminobutyric acid. Specific examples of vitamins include vitamin A, β-carotene, vitamin C, vitamin E, and vitamin K. 1 , Vitamin K 2 , folic acid, etc.
[0113] [Nutritional composition] In one embodiment, the present invention provides a nutritional composition comprising algae belonging to the Cyanidiophyceae family or an extract thereof.
[0114] The nutritional component composition of the present embodiment contains algae belonging to the Cyanidiophyceae family or an extract thereof, and therefore contains a wealth of nutritional components that are abundant in the algae. For example, the composition may be rich in nutritional components selected from the group consisting of amino acids, vitamins, proteins, lipids, and dietary fiber, and may be particularly rich in nutritional components selected from the group consisting of amino acids and vitamins. Therefore, the composition may be incorporated into nutrients, foods, feed, pet foods, cosmetics, etc., which will be described later.
[0115] The algae belonging to the class Polytrichum are not particularly limited, but preferred examples include the above-mentioned Polytrichum commune and algae belonging to the genus Cyanidioschyzon.
[0116] The present algae may have a diploid cell form, a haploid cell form, or a mixture of diploid and haploid cell forms. For example, the present algae may be cells recovered from the algae culture of the above embodiment. Examples of the present algae contained in the nutrient component composition of the present embodiment include those listed in the above section "Algae having diploid and haploid cell forms". Specific examples include the YFU3 strain and the HKN1 strain, as well as their closely related species and mutants. In addition, other algae belonging to the genus Cyanidium and algae belonging to the genus Garderia may also be mentioned. Among these, the YFU3 strain, the HKN1 strain, and mutants thereof, as well as algae belonging to the genus Garderia are preferred, and the YFU3 strain, the HKN1 strain, and mutants thereof are more preferred. When either the diploid cell form or the haploid cell form does not have a strong cell wall, it is preferable to use the cell form that does not have a strong cell wall. This has the advantage that it is easy to extract nutritional components. In addition, even if the algae cells are blended in the nutritional component composition as they are, it has the advantage that the nutritional components in the algae cells are easily absorbed after ingestion of the nutritional component composition. For example, when using the YFU3 strain, the HKN1 strain, or a mutant strain thereof, it is preferable to use the YFU3 strain (haploid), the HKN1 strain (haploid), or a mutant strain thereof. In addition, the haploid cell form of algae belonging to the genus Galdelia (e.g., Galdieria sulphuraria, Galdieria partita, etc.) and the haploid cell form of algae belonging to the genus Cyanidium are also preferred examples. Among them, the YFU3 strain (haploid), the HKN1 strain (haploid), or a mutant strain thereof, and the haploid cell form of algae belonging to the genus Galdelia are preferred.
[0117] The algae belonging to the class Polytrichum may be algae belonging to the class Polytrichum other than this alga. Among them, algae belonging to the genus Cyanidioschizon do not have a strong cell wall. Therefore, the cells can be destroyed by relatively mild treatments such as neutralization treatment, hypotonic treatment, and freeze-thaw treatment. Therefore, algae belonging to the genus Cyanidioschizon (e.g., Cyanidioschizon melorae) are preferred examples of algae belonging to the class Polytrichum.
[0118] Algae belonging to the class Polytrichum are cultured and grown in an appropriate medium, collected by a known method such as centrifugation or filtration, and appropriately washed, dried, etc., before being used in the nutrient of this embodiment. Alternatively, algae cells may be collected from the algae culture of the above embodiment, and appropriately washed, dried, etc., before being used in the nutrient composition of this embodiment.
[0119] Furthermore, the nutritional composition of this embodiment may contain an extract of algae belonging to the class Polytrichum communes, instead of or in addition to algae belonging to the class Polytrichum communes.
[0120] The nutritional component composition of the present embodiment may contain other components as appropriate in addition to the algae belonging to the class Polytrichum or an extract thereof. Examples of other components include, but are not limited to, pharmaceutical acceptable carriers. The term "pharmaceutical acceptable carrier" refers to a carrier that does not inhibit the function of the nutritional components contained in the algae belonging to the class Polytrichum and does not show substantial toxicity to the subject of administration. The term "not substantially toxic" means that the component does not show toxicity to the subject of administration at a dose normally used. Examples of pharmaceutical acceptable carriers include, but are not limited to, excipients, binders, disintegrants, lubricants, emulsifiers, stabilizers, diluents, oil bases, thickeners, antioxidants, reducing agents, oxidizing agents, chelating agents, solvents, etc. One type of pharmaceutical acceptable carrier may be used alone, or two or more types may be used in combination.
[0121] The content of the algae belonging to the class Polytrichum commune or an extract thereof in the nutritional component composition of this embodiment is not particularly limited and can be appropriately selected, for example, within the range of 1 to 100% by mass. The content of the algae belonging to the class Polytrichum commune or an extract thereof in the nutritional supplement of this embodiment is preferably 50 to 100% by mass, more preferably 60 to 100% by mass, and even more preferably 70 to 100% by mass. The algae belonging to the class Polytrichum or an extract thereof can be mixed with other ingredients as appropriate and made into a form such as dry powder, granules, tablets, jelly, liquid, capsules, etc. according to standard methods.
[0122] [Nutritional supplements] In one embodiment, the present invention provides a nutritional supplement comprising algae belonging to the class Polytrichum commune or an extract thereof.
[0123] A nutrient is used to supply nutritional components to humans or non-human animals, and there are no particular limitations on the dosage form, degree of purification, etc. As described above, algae belonging to the class Polytrichum contain many nutritional components such as amino acids and vitamins, so that by using algae belonging to the class Polytrichum or an extract thereof, a nutrient containing many nutritional components such as amino acids and vitamins can be obtained. The nutrient of this embodiment contains many nutritional components such as amino acids and vitamins, and can therefore be used for humans and non-human animals as a nutritional supplement for supplementing these nutritional components. Examples of nutritional components supplied by the nutrient of this embodiment include amino acids, vitamins, proteins, lipids, dietary fiber, and the like. In particular, the nutrient of this embodiment contains amino acids (isoleucine, leucine, lysine, methionine, cystine, phenylalanine, tyrosine, threonine, tryptophan, valine, arginine, histidine, alanine, aspartic acid, glutamic acid, glycine, proline, serine, γ-aminobutyric acid, etc.) and vitamins (vitamin A, β-carotene, vitamin B 1 , Vitamin B 2 , Vitamin B 6 , Vitamin C, Vitamin E, Vitamin K 1 , Vitamin K 2In the case where the algae belonging to the class Polytrichum commune are the present algae, the nutrient of this embodiment can be suitably used to supply amino acids (isoleucine, leucine, lysine, methionine, cystine, phenylalanine, tyrosine, threonine, tryptophan, valine, arginine, histidine, alanine, aspartic acid, glutamic acid, glycine, proline, serine, γ-aminobutyric acid, etc.) and vitamins (vitamin A, β-carotene, vitamin B 1 , Vitamin B 2 , Vitamin B 6 , Vitamin C, Vitamin E, Vitamin K 1 , Vitamin K 2 It can be suitably used to supplement vitamin C, niacin, inositol, folic acid, biotin, etc. The nutritional agent of the present embodiment is particularly composed of γ-aminobutyric acid, β-carotene, vitamin C, vitamin E, vitamin K, 1 , Vitamin K 2 It can be suitably used to supplement folic acid.
[0124] The nutritional agent of the present embodiment may contain other components as appropriate in addition to the algae belonging to the Polytrichum class or an extract thereof. Examples of other components include, but are not limited to, pharmaceutical acceptable carriers. Examples of pharmaceutical acceptable carriers include the same as those exemplified in the above "Nutritional component composition". One type of pharmaceutical acceptable carrier may be used alone, or two or more types may be used in combination.
[0125] The content of the algae belonging to the class Polytrichum commune or an extract thereof in the nutrient of this embodiment is not particularly limited and can be appropriately selected, for example, within the range of 1 to 100% by mass. The content of the algae belonging to the class Polytrichum commune or an extract thereof in the nutrient of this embodiment is preferably 50 to 100% by mass, more preferably 60 to 99% by mass, and even more preferably 70 to 99% by mass. The algae belonging to the class Polytrichum or an extract thereof can be mixed with other ingredients as appropriate and made into a form such as dry powder, granules, tablets, jelly, liquid, capsules, etc. according to standard methods.
[0126] The nutritional supplement of the present embodiment may be used as is for humans or organisms other than humans, or may be incorporated into nutritional supplement compositions such as foods, feeds, pet foods, cosmetics, etc., which will be described later. By incorporating the nutritional supplement of the present embodiment, a composition suitable for supplementing nutritional components such as amino acids and vitamins can be prepared.
[0127] In another aspect, the present invention provides a method for producing a nutrient supplement, comprising the steps of culturing algae belonging to the class Polytrichum commune, recovering the cultured algae belonging to the class Polytrichum commune, and formulating the recovered algae belonging to the class Polytrichum commune. In another aspect, the present invention provides a method for producing a nutrient supplement, comprising the steps of culturing algae belonging to the class Polytrichum commune, recovering the cultured algae belonging to the class Polytrichum commune, obtaining an extract of the recovered algae belonging to the class Polytrichum commune, and formulating the extract of the algae belonging to the class Polytrichum commune.
[0128] [Nutritional supplement composition] In one embodiment, the present invention provides a nutritional composition comprising the nutritional agent described above.
[0129] In this specification, the term "composition for supplementing nutritional components" refers to a composition used for humans or animals other than humans to take in nutritional components into the body. The intake of nutritional components into the body may be oral or parenteral.
[0130] The nutritional component supplement composition of the present embodiment contains a large amount of amino acids, vitamins, proteins, lipids, dietary fiber, etc. These components are the nutritional components that are contained in large amounts in the above-mentioned nutrients. Among these, the nutritional component supplement composition of the present embodiment is characterized by its high amino acid and vitamin content. In particular, it is characterized by its high content of gamma-aminobutyric acid among amino acids, and beta-carotene, vitamin C, vitamin E, and vitamin K among vitamins. 1 , Vitamin K 2 It is characterized by its high content of vitamin C, folic acid, and γ-aminobutyric acid, for example, is known to improve brain function and lower blood pressure. In addition, β-carotene, vitamin C, and vitamin E are known to have antioxidant properties. Vitamin K 1 , Vitamin K 2 is known to have an effect of improving osteoporosis. Folic acid is also known to be necessary for fetal development during pregnancy, and has also been reported to have an effect of improving cardiovascular diseases. Therefore, by taking the nutritional component supplement composition of this embodiment, the physical condition improving effect of the nutritional components as described above can be obtained. Therefore, the nutritional component supplement composition of this embodiment is preferably used to supplement at least one nutritional component selected from amino acids, vitamins, proteins, lipids, and dietary fibers. In addition, the nutritional component supplement composition of this embodiment is more preferably used to supplement at least one nutritional component selected from the group consisting of amino acids and vitamins.
[0131] The nutritional supplement composition of the present embodiment is not particularly limited as long as it is used for humans or animals other than humans to take in nutritional components into their bodies. Examples of the nutritional supplement composition of the present embodiment include food, feed, pet food, cosmetics, etc.
[0132] (food) The nutritional composition of the present embodiment may be a food. Therefore, the present invention also provides a food containing the nutritional composition or nutritional agent of the above embodiment. The present invention also provides a food containing algae belonging to the class Polytrichum or an extract thereof. When the nutritional supplement composition of the present embodiment is a food, the above-mentioned nutritional composition or nutrient agent may be added to the food as a food additive. By adding the above-mentioned nutritional composition or nutrient agent to a food, a food enriched with the nutritional components contained in the above-mentioned nutritional composition or nutrient agent can be prepared. Therefore, in another aspect, the present invention provides a food additive containing algae belonging to the class Polytrichum or an extract thereof. The food of this embodiment can be produced by adding the above-mentioned nutritional component composition or nutritional supplement to food ingredients, and optionally adding other food additives, according to a known method suitable for the type of food.
[0133] In the food of this embodiment, the type of food is not particularly limited. Examples of the food include various noodles such as soba, udon, harusame, Chinese noodles, instant noodles, and cup noodles; carbohydrates such as bread, wheat flour, rice flour, pancakes, and mashed potatoes; beverages such as green juice, soft drinks, carbonated drinks, nutritional drinks, fruit drinks, vegetable drinks, lactic acid drinks, milk drinks, sports drinks, tea, and coffee; soy products such as tofu, soybean pulp, and natto; various soups such as curry roux, stew roux, and instant soup; cold desserts such as ice cream, ice sherbet, and shaved ice; candy, cookies, candies, gum, chocolate, tablet sweets, Examples include, but are not limited to, confectioneries such as snacks, biscuits, jellies, jams, creams, and other baked goods; processed seafood and livestock foods such as kamaboko, hanpen, ham, and sausages; dairy products such as processed milk, fermented milk, butter, cheese, and yogurt; oils and fats and oil-based processed foods such as salad oil, tempura oil, margarine, mayonnaise, shortening, whipped cream, and dressings; condiments such as sauces, dressings, miso, soy sauce, and tare sauces; and other processed foods such as various retort foods, furikake, and pickles.
[0134] In the above-mentioned foods, the content of the above-mentioned nutritional composition or nutrient agent is not particularly limited, and the content may be appropriately set according to the type of food. For example, in consideration of the flavor of the food, the content of the above-mentioned nutritional composition or nutrient agent in the food can be 0.01 to 30 mass% as the content of algae belonging to the class Polytrichum or an extract thereof. From the viewpoint of the flavor of the food, the content is preferably 0.05 to 20 mass%, more preferably 0.1 to 15 mass%, further preferably 0.1 to 10 mass%, and particularly preferably 0.1 to 5 mass%.
[0135] The food may also be a functional food or a nutritional supplement. The functional food or nutritional supplement may be in the form of a general food as described above, or in the form of a dry powder, granules, tablets, jellies, drinks, etc. In this case, the above-mentioned nutritional component composition or nutritional agent can be mixed with other components as appropriate to form a dry powder, granules, tablets, jellies, drinks, etc. according to a standard method. The other components are not particularly limited, and examples thereof include pharmaceutical acceptable carriers. Examples of pharmaceutical acceptable carriers include those listed in the above "Nutritional component composition". In addition, in order to improve the flavor, etc., sweeteners, flavorings, various seasonings, flavorings, oils and fats, other food additives, etc. may be used as other components. The other components may be used alone or in combination of two or more types.
[0136] In the functional food or nutritional supplement as described above, the content of the above-mentioned nutritional component composition or nutrient agent is not particularly limited, and the content may be appropriately set according to the type of functional food or nutritional supplement. For example, when the functional food or nutritional supplement is in the form of a dry powder, granule, tablet, etc., the content of the above-mentioned nutritional component composition or nutrient agent in the functional food or nutritional supplement is, for example, 0.1 to 99 mass% as the content of algae belonging to the class Polytrichum or an extract thereof. From the viewpoint of flavor and efficient supply of nutritional components, 1 to 90% by mass is preferable, 10 to 85% by mass is more preferable, 20 to 85% by mass is even more preferable, and 25 to 85% by mass is particularly preferable. When the functional food or nutritional supplement is in the form of a jelly, drink, or the like, the content of the above-mentioned nutrients in the functional food or nutritional supplement is, for example, 0.05 to 80% by mass as the content of algae belonging to the class Polytrichum or an extract thereof. From the viewpoint of efficient supply of flavor and nutritional components, 1 to 75% by mass is preferable, 10 to 70% by mass is more preferable, 15 to 70% by mass is even more preferable, and 20 to 70% by mass is particularly preferable.
[0137] The food of the present embodiment can be ingested to efficiently replenish the above-mentioned nutritional components contained in the algae belonging to the class Polytrichum. The food of the present embodiment can be ingested to efficiently replenish nutritional components selected from the group consisting of amino acids, vitamins, proteins, lipids, and dietary fiber. Among these nutritional components, the food of the present embodiment is effective for the intake of nutritional components selected from the group consisting of amino acids and vitamins.
[0138] (Feed, pet food) The nutritional supplement composition of the present embodiment may be a feed or a pet food. Therefore, the present invention also provides a feed or a pet food containing the nutritional composition or the nutrient of the above embodiment. The present invention also provides a feed or a pet food containing an alga belonging to the class Polytrichum or an extract thereof. When the nutritional component supplement composition of this embodiment is a feed or pet food, the above-mentioned nutritional component composition or nutrient agent may be added to the feed or pet food as a feed additive or pet food additive. By adding the above-mentioned nutritional component composition or nutrient agent to the feed or pet food, a feed or pet food containing enhanced nutritional components contained in the above-mentioned nutritional component composition or nutrient agent can be prepared. Therefore, in another aspect, the present invention provides a feed additive or pet food additive containing algae belonging to the class Polytrichum or an extract thereof.
[0139] The feed or pet food of this embodiment can be produced by adding the above-mentioned nutritional component composition or nutritional supplement to feed raw materials or pet food raw materials, and optionally adding other feed additives or pet food additives, according to a known method appropriate for the type of feed raw materials or pet food.
[0140] The type of animal to which the feed or pet food of the present embodiment is given is not particularly limited, and examples thereof include, but are not limited to, livestock (cattle, pigs, chickens, horses, sheep, goats, etc.), fish, shellfish, and pets (dogs, cats, hamsters, rabbits, parakeets, tropical fish, reptiles, amphibians, insects, etc.).
[0141] In the feed or pet food of this embodiment, the content of the above-mentioned nutritional component composition or nutrient agent is not particularly limited, and the content may be appropriately set according to the type of feed or pet food. For example, the content of the above-mentioned nutritional component composition or nutrient agent in the feed or pet food is, for example, 0.01 to 90 mass % as the content of algae belonging to the class Polytrichum or an extract thereof, preferably 0.1 to 80 mass %, more preferably 1 to 70 mass %, and particularly preferably 1 to 60 mass %.
[0142] The feed or pet food of this embodiment can be used to efficiently supply the animal with the above-mentioned nutritional components contained in the algae belonging to the class Polytrichum. The feed or pet food of this embodiment can be used to efficiently supply the animal with nutritional components selected from the group consisting of amino acids, vitamins, proteins, lipids, and dietary fiber. Among these nutritional components, the feed or pet food of this embodiment is effective for the intake of nutritional components selected from the group consisting of amino acids and vitamins.
[0143] (cosmetics) The nutritional composition of the present embodiment may be a cosmetic. Thus, the present invention also provides a cosmetic comprising the nutritional composition or nutrient of the above embodiment. The present invention also provides a cosmetic comprising an alga belonging to the Polytrichum class or an extract thereof. When the nutritional component supplement composition of the present embodiment is a cosmetic product, the above-mentioned nutritional component composition or nutrient may be added to the cosmetic product as a cosmetic additive. By adding the above-mentioned nutritional component composition or nutrient to the cosmetic product, a cosmetic product containing the nutritional components contained in the above-mentioned nutritional component composition or nutrient can be prepared. Therefore, in another aspect, the present invention provides a cosmetic additive containing algae belonging to the class Polytrichum or an extract thereof.
[0144] The cosmetic product of this embodiment can be produced by mixing the above-mentioned nutritional component composition or nutritional supplement with other components as appropriate, according to a known method according to the type of cosmetic product. The other components are not particularly limited, and examples thereof include pharma- ceutically acceptable carriers. Examples of pharma-ceutically acceptable carriers include those listed in the above "[Nutritional component composition]". Materials known as cosmetic additives may also be used as other components. One type of other component may be used alone, or two or more types may be used in combination.
[0145] In the cosmetics of the present embodiment, the type of cosmetics is not particularly limited. Examples of cosmetics include, but are not limited to, basic cosmetics such as skin lotion, milky lotion, cream, gel, sunscreen, pack, mask, and beauty essence; makeup cosmetics such as foundations, makeup bases, lipsticks, lip gloss, and blush; cleansing agents such as face washes, body shampoos, and cleansing agents; hair cosmetics such as shampoos, rinses, hair conditioners, treatments, and hair styling agents; and body cosmetics such as body powders and body lotions.
[0146] In the cosmetic of this embodiment, the content of the nutritional component composition or nutrient agent is not particularly limited, and the content may be appropriately set according to the type of cosmetic. For example, in consideration of the feel of the cosmetic, the content of the nutritional component composition or nutrient agent in the cosmetic can be 0.01 to 30 mass% as the content of algae belonging to the class Polytrichum or an extract thereof. From the viewpoint of the feel of the cosmetic, the content is preferably 0.1 to 20 mass%, more preferably 0.1 to 15 mass%, even more preferably 0.1 to 10 mass%, and particularly preferably 0.1 to 5 mass%.
[0147] The cosmetic product of the present embodiment can be applied to the skin or hair to supply the skin or hair with the above-mentioned nutritional components contained in the algae belonging to the Polytrichum commune. The cosmetic product of the present embodiment can be applied to the skin or hair to supply the skin or hair with nutritional components selected from the group consisting of amino acids, vitamins, proteins, lipids, and dietary fiber. Among these nutritional components, the cosmetic product of the present embodiment is effective in supplying nutritional components selected from the group consisting of amino acids and vitamins.
[0148] In another aspect, the present invention provides a method for producing a food product, the method comprising the step of incorporating an alga belonging to the class Polytrichum or an extract thereof into a food product. In another aspect, the present invention provides a method for producing a functional food or dietary supplement, comprising the step of mixing an alga belonging to the class Polytrichum, or an extract thereof, with a pharma- ceutically acceptable carrier. In another aspect, the present invention provides a method for producing feed or pet food, comprising the step of incorporating an alga belonging to the class Polytrichum or an extract thereof into the feed or pet food. In another aspect, the present invention provides a method for producing a cosmetic, comprising the step of incorporating an alga belonging to the class Polytrichum or an extract thereof into a cosmetic. In another aspect, the present invention provides a method for producing a food additive, a feed additive, a pet food additive, or a cosmetic additive, comprising the steps of culturing algae belonging to the class Polytrichum commune, recovering the cultured algae belonging to the class Polytrichum commune, and formulating the recovered algae belonging to the class Polytrichum commune. In another aspect, the present invention provides a method for producing a food additive, a feed additive, a pet food additive, or a cosmetic additive, comprising the steps of culturing algae belonging to the class Polytrichum commune, recovering the cultured algae belonging to the class Polytrichum commune, obtaining an extract of the recovered algae belonging to the class Polytrichum commune, and formulating the extract of the algae belonging to the class Polytrichum commune.
[0149] [Manufacturing method of nutritional ingredients] In one embodiment, the present invention provides a method for producing a nutritional component, the method for producing a nutritional component of this embodiment comprising the steps of (a) disrupting cells of an alga belonging to the class Polytrichum to obtain a cell disruptant, and (b) separating at least one nutritional component from the cell disruptant. Each step of the manufacturing method of this embodiment will be described below.
[0150] (Step (a)) Step (a) is a step of disrupting cells of algae belonging to the class Polytrichum commune to obtain a cell disruptant.
[0151] Suitable examples of the algae belonging to the class Polytrichum used in this step include the above-mentioned algae and algae belonging to the genus Cyanidioschyzon (e.g., Cyanidioschyzon melorae). Suitable examples of the algae include those described in the above section "Algae having diploid and haploid cell morphologies". Specific examples include the YFU3 and HKN1 strains, as well as their closely related species and mutants. Other algae belonging to the genus Cyanidium and algae belonging to the genus Garderia are also suitable. Among these, the YFU3 and HKN1 strains and their mutants, as well as algae belonging to the genus Garderia are preferred, and the YFU3 and HKN1 strains and their mutants are more preferred. The algae may have a diploid cell morphology, a haploid cell morphology, or a mixture of diploid and haploid cell morphologies. For example, the cells may be cells recovered from the algae culture of the above embodiment. Therefore, the production method of this embodiment also provides a method for producing a nutrient component, comprising: (a) recovering algae from the algae culture of the above embodiment; (b) destroying the algae cells to obtain a cell disruptant; and (c) separating at least one nutrient component from the cell disruptant. When either the diploid cell form or the haploid cell form does not have a strong cell wall, it is preferable to use the cell form that does not have a strong cell wall. This allows the cells to be destroyed by a relatively mild treatment. For example, when using the YFU3 strain, the HKN1 strain, or a mutant strain thereof, it is preferable to use the YFU3 strain (haploid), the HKN1 strain (haploid), or a mutant strain thereof. In addition, the haploid cell form of algae belonging to the genus Galdelia (e.g., Galdieria sulphuraria, Galdieria partita, etc.) and the haploid cell form of algae belonging to the genus Cyanidium are also preferred examples. Among them, the YFU3 strain (haploid), the HKN1 strain (haploid), or a mutant strain thereof, and the haploid cell form of algae belonging to the genus Galdelia are preferred.
[0152] The method for disrupting the cells of algae belonging to the class Polytrichum commune is not particularly limited, and known methods can be used. Examples of cell disruption methods include physical treatments such as glass beads, mortars, ultrasonic treatment, French press, and homogenizers, and chemical treatments such as neutralization treatment, hypotonic treatment, freeze-thaw treatment, and dry-swelling treatment. These treatments may be performed alone or in combination of two or more types.
[0153] When algae belonging to the class Polytrichum commune do not have a strong cell wall, the cells can be destroyed by relatively mild treatments such as neutralization treatment, hypotonic treatment, freeze-thaw treatment, and dry-swelling treatment. These treatments have low energy costs and can be easily carried out compared to physical treatments. Therefore, when algae belonging to the class Polytrichum commune that do not have a strong cell wall are used, neutralization treatment, hypotonic treatment, freeze-thaw treatment, and dry-swelling treatment are preferred as cell destruction methods. In addition, any of the cell rupture treatments (1) to (3) above is also a suitable example of a cell destruction method.
[0154] As a method of neutralization treatment, a method of immersing cells of algae belonging to the class Polytrichum commune, which do not have a strong cell wall, in a neutralizing solution of about pH 7 to 10 can be mentioned. Since algae belonging to the class Polytrichum commune are adapted to an acidic pH range, if they do not have a strong cell wall, the cells are destroyed by immersing them in a neutral to basic neutralizing solution. The composition of the neutralizing solution is not particularly limited, but for example, a buffer solution such as a phosphate buffer or a Tris buffer can be used. The time for immersing the cells in the neutralizing solution may be a time sufficient for the cells to be destroyed, for example, about one week. A preferable example is the cell disruption treatment described in (1) above. An example of the hypotonic treatment method is a method of immersing cells of algae belonging to the class Polytrichum commune in a hypotonic solution such as water. Among algae belonging to the class Polytrichum commune, those that do not have a strong cell wall will burst when immersed in a hypotonic solution such as water. The composition of the hypotonic solution is not particularly limited, and any hypotonic liquid that can burst cells of algae belonging to the class Polytrichum commune may be used. Examples of the hypotonic solution include water and a buffer solution with a low salt concentration. The time for immersing the cells in the hypotonic solution may be a time that can burst cells, for example, about 1 to 30 minutes. After immersion in the hypotonic solution, the algae cells may be collected by centrifugation or the like and resuspended in the hypotonic solution repeatedly. The number of times of resuspension is not particularly limited, but may be 1 to 5 times. A preferable example is the cell rupture treatment described in (2) above. The method of the freeze-thaw treatment includes a method in which the cells of the algae belonging to the class Polytrichum commune are subjected to one or more cycles of freezing and thawing. The number of cycles of freezing and thawing is not particularly limited, and may be any number sufficient to destroy the cells of the algae belonging to the class Polytrichum commune, which do not have a strong cell wall. The number of cycles of freezing and thawing is, for example, about 1 to 5 times. The times for each of freezing and thawing are not particularly limited, and for example, each of about 10 to 30 minutes is exemplified. The drying and swelling treatment method may be a method in which the algae cells are subjected to one or more cycles of drying and resuspension in a buffer solution. The number of cycles of drying and resuspension is not particularly limited, and may be a number sufficient to destroy the cells of algae belonging to the class Polytrichum, which does not have a strong cell wall. The number of cycles of drying and resuspension may be, for example, about 1 to 5 times. A suitable example is the cell rupture treatment described in (3) above.
[0155] By disrupting the cells of algae belonging to the class Polytrichum commune using the method described above, a cell disruptant of algae belonging to the class Polytrichum commune can be obtained.
[0156] (Step (b)) Step (b) is a step of separating at least one nutrient component from the cell disruption of algae belonging to the class Polytrichum.
[0157] In this step, the nutritional components to be separated are not particularly limited as long as they are nutritional components contained in algae belonging to the class Polytrichum. As described above in "[Algae having diploid and haploid cell morphologies]", algae belonging to the class Polytrichum contain many nutritional components such as amino acids, vitamins, proteins, lipids, and dietary fiber. Therefore, the nutritional components to be separated in this step include at least one selected from the group consisting of amino acids, vitamins, proteins, lipids, and dietary fiber.
[0158] Among the above nutritional components, in this step, it is preferable to separate at least one nutritional component selected from the group consisting of amino acids and vitamins. Specific examples of amino acids include at least one selected from the group consisting of isoleucine, leucine, lysine, methionine, cystine, phenylalanine, tyrosine, threonine, tryptophan, valine, arginine, histidine, alanine, aspartic acid, glutamic acid, glycine, proline, serine, and γ-aminobutyric acid. Preferably, as amino acids, γ-aminobutyric acid is included. In addition, specific examples of vitamins include vitamin A, β-carotene, vitamin B 1 , vitamin B 2 , vitamin B 6 , vitamin C, vitamin E, vitamin K 1 , vitamin K 2 , and at least one selected from the group consisting of niacin, inositol, folic acid, and biotin. In particular, when the algae belong to the class Idejukogome, specific examples of vitamins include vitamin A, β-carotene, vitamin C, vitamin E, vitamin K 1 , vitamin K 2 , and at least one selected from the group consisting of folic acid. Preferably, as vitamins, at least one selected from the group consisting of β-carotene, vitamin C, vitamin E, vitamin K 1 , vitamin K 2 , and folic acid is included.
[0159] The nutritional components separated in this step may be one kind or two or more kinds. In addition, they may be separated by type, such as amino acids, fat-soluble vitamins (vitamin A, β-carotene, vitamin E, vitamin K 1 , vitamin K 2 , etc.), water-soluble vitamins (vitamin B 1 , vitamin B 2 , vitamin B 6 , vitamin C, niacin, inositol, folic acid, biotin, etc.).
[0160] The method for separating nutritional components from cell disruption products is not particularly limited, and an appropriate method may be selected depending on the type of nutritional components. As a method for separating nutritional components, a suitable combination of methods generally used for the separation and purification of biochemical substances can be used. Examples of the separation method include, but are not limited to, centrifugation, washing, salting out, dialysis, recrystallization, reprecipitation, solvent extraction, adsorption, concentration, filtration, gel filtration, ultrafiltration, and various types of chromatography (thin layer chromatography, column chromatography, ion exchange chromatography, high performance liquid chromatography, adsorption chromatography, etc.).
[0161] (Optional process) The manufacturing method of this embodiment may include other steps in addition to steps (a) and (b). Examples of the other steps include a step of culturing algae belonging to the class Polytrichum commune (cultivation step), a step of recovering algae belonging to the class Polytrichum commune from a culture solution (recovery step), a step of washing cells of algae belonging to the class Polytrichum commune (washing step), a step of low-temperature treating algae belonging to the class Polytrichum commune (low-temperature treatment step), a step of drying algae belonging to the class Polytrichum commune (drying step), a step of freezing algae belonging to the class Polytrichum commune (freezing step), etc. These steps can be performed before the above-mentioned step (a).
[0162] The culturing step can be carried out by the method described above in "Algae belonging to the class Cyanidiophyceae" or "Algae having diploid and haploid cell morphologies". The recovery step can be carried out by known methods such as filtration and centrifugation. The washing step can be carried out by suspending the cells in a washing solution (such as a buffer solution) of pH 1.0 to 6.0, and then recovering the cells from the washing solution by a method such as filtration or centrifugation.
[0163] The low-temperature treatment step can be carried out by treating algae belonging to the class Polytrichum commune at a temperature of 0 to 5°C. For example, when the cells of the algae belonging to the class Polytrichum commune recovered through the above-mentioned culture and recovery steps are placed in a temperature environment of 0 to 5° C., the algae cells can be killed. Therefore, even transformants that are not based on self-cloning can be handled in an open system. The duration of the low-temperature treatment is not particularly limited, but may be, for example, 8 days or more, preferably 10 days or more.
[0164] The drying step can be carried out by drying the algae belonging to the class Polytrichum commune in a dryer such as a room temperature dryer, a low temperature dryer, or a freeze dryer. For example, if the cells of the algae belonging to the class Polytrichum commune that have been recovered through the above-mentioned culturing step and recovery step are dried in a dryer, the algae cells can be killed. Therefore, even transformants that are not based on self-cloning can be handled in an open system.
[0165] The freezing step can be carried out by freezing algae belonging to the class Polytrichum commune using liquid nitrogen, a freezer, or the like. For example, the algal cells belonging to the class Polytrichum commune that have been recovered through the above-mentioned culture and recovery steps can be killed by placing them in an environment at or below −4° C., preferably at or below −20° C. Therefore, even transformants that are not based on self-cloning can be handled in an open system. The freezing time is not particularly limited, but may be, for example, 10 minutes or more, and preferably 30 minutes or more.
[0166] The nutritional components produced by the production method of this embodiment can be used for various purposes such as nutrients, foods, feeds, pet foods, cosmetics, pharmaceuticals, and reagents.
[0167] [Other aspects] Algae belonging to the class Polytrichum are acid resistant, and therefore are considered to be resistant to gastric acid. On the other hand, among algae belonging to the class Polytrichum, those that do not have a strong cell wall (e.g., YFU3 strain (haploid), HKN1 strain (haploid), algae belonging to Cyanidioschizon (e.g., Cyanidioschizon melorae), haploid algae belonging to the genus Garderia, haploid algae belonging to the genus Cyanidium, etc.) undergo cell rupture in a neutral environment (pH 7 to 10 or so), and therefore are considered to undergo cell rupture in the intestinal tract. Furthermore, a transformation system has been established, and any gene can be introduced. Therefore, by preparing a transformant into which a gene that produces any drug is introduced, the transformant can be used as a drug capsule resistant to gastric acid. Therefore, the present invention also provides a pharmaceutical composition containing algae belonging to the class Polytrichum into which a drug-producing gene is introduced. The term "drug-producing gene" refers to a gene that is expressed in the cells of algae belonging to the class Polypodiaceae, and the translation product of the gene produces a drug for treating or preventing a disease in humans or non-human animals (such as mammals). The translation product of the drug-producing gene may itself be a drug, or the translation product of the drug-producing gene may be an enzyme that catalyzes a drug synthesis reaction.
[0168] The drug is not particularly limited, but examples thereof include antigen proteins of pathogenic microorganisms or pathogenic viruses. Examples of pathogenic viruses include, but are not particularly limited to, rabies virus, porcine circovirus, bovine rotavirus, influenza virus, AIDS virus, etc. Algae belonging to the class Polytrichum into which antigen proteins of these pathogenic microorganisms or pathogenic viruses have been introduced can be used as vaccines against infectious diseases caused by these. EXAMPLES
[0169] The present invention will be described below with reference to examples, but the present invention is not limited to the following examples.
[0170] [Example 1] Analysis of components of algae belonging to the class Polytrichum. (Cultivation of algae belonging to the class Polytrichum) Cyanidioschyzon melorae 10D was cultured in 5 L of 2× Allen medium with aeration. The culture temperature was approximately 35°C and the medium was exposed to continuous white light (500 μmol / m 2 The culture was carried out for 2 weeks under the conditions of The composition of 2x Allen medium is shown in Table 1.
[0171] [Table 1]
[0172] (Component analysis of algae belonging to the class Polytrichum) [Amino acids, vitamins, etc.] The cells of C. melorae 10D cultured as described above were collected by centrifugation and analyzed by the Japan Food Research Center. The values per wet weight obtained by the above analysis were converted to values per dry weight by dividing them by 0.248.
[0173] The analytical methods for each component are shown in Tables 2 and 3.
[0174] [Table 2]
[0175] [Table 3]
[0176] The results of the component analysis are shown in Tables 4 to 6. Table 4 shows the results of the amino acid analysis, Table 5 shows the results of the vitamin analysis, and Table 6 shows the results of the other nutritional components analysis. For reference, published analytical values for Chlorella, Euglena, and Spirulina are also listed in Tables 4 and 5. In Tables 4 to 6, Cyanidioschyzon melorae 10D is abbreviated as "Schizon."
[0177] [Table 4]
[0178] [Table 5]
[0179] [Table 6]
[0180] As shown in Table 4, it was revealed that Cyanidioschyzon melorae 10D has a higher total amino acid content than other algae that are conventionally used for food, etc. In addition, the content of each amino acid in Schizon tended to be higher than that in other algae. It was also confirmed that Cyanidioschyzon melorae contains γ-aminobutyric acid. γ-aminobutyric acid functions as an inhibitory neurotransmitter, and is known to have effects such as improving brain function, lowering blood pressure, and sedative effects. Tomatoes are known as a food that contains a lot of γ-aminobutyric acid, and it has been reported that the γ-aminobutyric acid content of tomatoes is 0.062g / 100g wet weight (Understanding the increasingly popular supplements - for use by patients with renal failure [Special Topic] 8 GABA, Clinical Dialysis Vol. 24. No. 13, December 2008). It can be said that the γ-aminobutyric acid content of Cyanidioschyzon melorae is comparable to that of tomatoes.
[0181] As shown in Table 5, Cyanidioschyzon melorae tended to contain more vitamins than other algae. In particular, it contained more β-carotene, vitamin C, vitamin E, and vitamin K than other algae. 1 , Vitamin K 2 , and had a high folic acid content. Almonds are known to be a food rich in vitamin E, and the vitamin E content of almonds is reported to be 30.3 mg / 100 g wet weight (Standard Tables of Food Composition in Japan, 2015 edition). Natto is known to be a food rich in vitamin K, and the vitamin K content of natto is reported to be 600 μg / 100 g wet weight (Standard Tables of Food Composition in Japan, 2015 edition). The vitamin E and vitamin K content of Schizon is higher than those foods.
[0182] These results confirmed that Cyanidioschyzon melorae has a higher content of nutrients such as amino acids and vitamins than other algae that are traditionally used for food, etc.
[0183] [Example 2] Preparation of a strain with enhanced γ-aminobutyric acid production (Preparation of transformation fragments) The transformation fragment was prepared by the method described in Fujiwara et al. (PLoS One. 2013 Sep 5;8(9):e73608). The primers used to prepare the transformation fragment are shown in Table 7. The primers used are described below with the primer numbers shown in Table 7.
[0184] [Table 7]
[0185] <EGFP / URA Cm-Cm Preparation of fragments> URA Cm-CmTo generate a selection marker, a DNA fragment containing the URA5.3 gene (including 897 bp upstream sequence and 471 downstream sequence) was amplified by PCR using primer set No. 1 / 2 with the genomic DNA of Cyanidioschyzon melorae 10D as a template. The CMD184C fragment (including the last 1,961 bp and 1.9 kb downstream sequence of the CDC184C ORF) and the pQE80 vector (QIAGEN) were amplified by PCR using primer set No. 3 / 4 and primer set No. 5 / 6, respectively. The CMD184C fragment was subcloned into the pQE80 vector using the In-Fusion HD Cloning Kit (Clontech). The resulting pD184 vector was amplified by PCR using primer set No. 7 / 8. The upstream sequence of CMO250C (-600 to -1: SEQ ID NO: 9), EGFP The ORF (Takara Bio Inc.), and the downstream sequence of β-tubulin (+1 to +200) were amplified by PCR using primer set No. 9 / 10, primer set No. 11 / 12, and primer set No. 13 / 14, respectively, and subcloned into pQE using the In-Fusion HD Cloning Kit. Using the resulting pQ250-EGFP vector as template DNA, the assembly fragment (the upstream region of CMO250C [-600 to -1], EGFP ORF, and the downstream region of β-tubulin [+1 to +200]) was amplified by PCR using primer set No. 15 / 16, and subcloned into the amplified pD184 vector. The resulting pD184-O250-EGFP vector was amplified by PCR using primer set No. 17 / 18. URA Cm-Cm The selection marker was subcloned into the amplified pD184-O250-EGFP vector. The resulting vector was pD184-O250-EGFP-URA Cm-Cm The vector was amplified using primer set No. 19 / 20 to amplify EGFP / URA Cm-Cm The amplified DNA fragment (EGFP / URA Cm-CmThe EGFP / URA fragment was used for transformation. Cm-Cm The EGFP / URA fragment was used as a negative control. Cm-Cm The fragment constructs are shown in FIG. 1(A).
[0186] <GAD / URA Cm-Cm Preparation of fragments> The same procedure as described above was repeated except that a DNA fragment with a 3×HA tag added to the 3' end of CMF072C (glutamic acid decarboxylase: GAD: SEQ ID NO: 3) from Cyanidioschyzon melorae was used instead of the EGFP ORF. <EGFP / URA Cm-Cm In the same manner as in "Creation of the fragment >", Cm-Cm The vector was constructed as follows: pD184-O250-GAD-URA Cm-Cm Using the vector as a template and primer set No. 19 / 20, Cm-Cm The fragment was amplified by PCR. The amplified DNA fragment (GAD / URA Cm-Cm The GAD / URA fragment was used for transformation. Cm-Cm The construct of the fragment is shown in FIG. 1(B).
[0187] <GAD / URA Cm-Gs Preparation of fragments> pD184-O250-GAD-URA Cm-Cm From Vector, URA Cm-Cm To remove the sequence containing the OMP-decarboxylase domain of URA5.3 from Galdieria sulphuraria, the vector was amplified by PCR using primer set No. 21 / 22. To remove the sequence containing the OMP-decarboxylase domain of URA5.3 from Galdieria sulphuraria, the vector was amplified by PCR using primer set No. 23 / 24 and URA Cm-Gs The selection marker was used as template DNA and amplified by PCR, and the sequence was cloned as pD184-O250-GAD-URA Cm-Cm The resulting vector was pD184-O250-EGAD-URA. Cm-GsThe vector was ligated to GAD / URA using primer set No. 19 / 20 and PrimeSTAR® MAX (Takara). Cm-Gs The amplified DNA fragment (GAD / URA Cm-Gs The GAD / URA fragment was used for transformation. Cm-Gs The construct of the fragment is shown in FIG. 1(C).
[0188] (Transformation) The parent strain for transformation was the uracil auxotrophic mutant Cyanidioschyzon melorae M4 (Minoda et al., Plant Cell Physiol. 2004 Jun;45(6):667-71.). Cells were grown in MA2 medium (Ohnuma M et al. Plant Cell Physiol. 2008 Jan;49(1):117-20.) containing uracil (0.5mg / mL) and 5-fluoroorotic acid (0.8mg / mL). Cultures were grown under continuous white light (80μmol / m 2 The cells were cultured at 40°C with shaking at 130 rpm for 10 min. The MA2 medium was solidified with 0.5% (w / v) gellan gum (Wako). To adjust the pH to 2.3, sulfuric acid was added to a final concentration of 0.05% (v / v). Transformation was performed according to the method described by Ohnuma M et al. (Plant Cell Physiol. 2008 Jan;49(1):117-20.) and Imamura S et al. (Plant Cell Physiol. 2010 May;51(5):707-17). 4 μg of each transformation fragment prepared above was used for transformation. The cells were cultured at 40°C under continuous white light until colonies were formed. The colonies were then transferred to starch on MA2 solid medium containing uracil (0.5 mg / mL).
[0189] (Immunoblotting) Cell lysates (4 μg protein) of each transformant were separated by SDS-PAGE (1 mm thick gel, 10% acrylamide, 25 mA for 50 min). Proteins in the gel were then transferred to a PVDF membrane (300 V, 400 mA, 75 min). Blocking was performed with 5% skim milk, and anti-HA antibody (16B12, 1:2,000) was reacted as the primary antibody for 1 hour. Next, anti-mouse HRP-labeled antibody (1:25,000) was reacted as the secondary antibody for 1 hour. Chemiluminescent signals were detected using Immoblin Western Chemiluminescent HRP Substrate (Milipore) and LAS-3000 (FUJI FILM).
[0190] The results are shown in Figure 2. In Figure 2, the right panel shows the stained gel after SDS-PAGE, and the left panel shows the results of immunoblotting. GAD / URA Cm-Cm Fragment transformants and GAD / URA Cm-Gs In the fragment transformants, chemiluminescence signals were detected. Cm-Cm No signal was detected in the transformed cells with the GAD / URA fragment. Cm-Cm Fragment transformants and GAD / URA Cm-Gs The results show that HA-tagged GAD was expressed in the transformant. Cm-Cm GAD / URA Cm-Gs The expression level of HA-tagged GAD was higher in the fragment transformants. Also, GAD / URA Cm-Cm The results of comparing the fragment transformants with the wild type (WT) are shown in Figure 3. Cm-Cm As shown in Fig. 2, expression of HA-tagged GAD was confirmed in the fragment transformants, whereas no signal was detected in the wild-type strain.
[0191] (Confirmation of GAD copy number in transformed strains) Real-Time PCR was performed using the primers shown in Table 8. It has been confirmed that the wild type strain of C. melorae has one copy of GAD (CMF072C). Therefore, EGFP / URA was used as a negative control. Cm-Cm In the fragment transformed strain, the value amplified using primer set A in Table 8 (value A) / the value amplified using primer set B in Table 8 (value B) = 1, and the copy number of GAD (CMF072C) in other transformed strains was confirmed.
[0192] As a result, GAD / URA Cm-Cm In the fragment transformant, one copy of GAD was introduced by transformation, and it was confirmed that the transformant had two copies of GAD, including the endogenous GAD. Cm-Gs In the fragment transformant, nine copies of GAD were introduced by transformation, and it was confirmed that the transformant had a total of 10 copies including the endogenous GAD. Cm-Gs The results of confirming the copy number in the fragment transformants are shown in FIG.
[0193] [Table 8]
[0194] (Measurement of intracellular γ-aminobutyric acid content in transformants) EGFP / URA Cm-Cm Fragment transformant, GAD / URA Cm-Cm Fragment transformants and GAD / URA Cm-Gs The fragment transformants were grown in MA2 medium under continuous white light at 40°C. After the culture, the cells were collected by centrifugation, and the soluble matter was extracted from the collected cells with 75% ethanol. The amount of γ-aminobutyric acid in the extracted soluble matter was quantified by the OPA-post-column derivatization method using HPLC.
[0195] The results are shown in Table 9. In Table 9, EGFP / URA Cm-CmThe values are shown as relative values when the γ-aminobutyric acid concentration (per dry cell weight) in the fragment transformant was set at 1.0.
[0196] [Table 9]
[0197] As shown in Table 9, GAD / URA Cm-Cm Fragment transformants and GAD / URA Cm-Gs In the fragment transformants, the negative control EGFP / URA Cm-Cm The concentration of γ-aminobutyric acid was higher in the transformed strain than in the fragment transformant. Cm-Cm Compared with the fragment transformants, GAD / URA Cm-Gs The fragment transformants had higher γ-aminobutyric acid concentrations, indicating that the intracellular γ-aminobutyric acid concentration increases with the number of GAD copies introduced. These results confirmed that it is possible to increase the intracellular concentration of specific nutritional components in C. melorae by transformation.
[0198] [Example 3] Cell rupture treatment of algae belonging to the genus Cyanidioschison (drying and swelling treatment of algae cells) Cyanidioschyzon melorae 10D was cultured in the same manner as in Example 1, and 1 mL of the culture solution was centrifuged (1,500 x g, 2 minutes). The supernatant after centrifugation was discarded, and the algal cell pellet was suspended in an isotonic solution (10% sucrose, 20 mM HEPES, pH 7.0) and centrifuged (1,500 x g, 3 minutes) to wash the algal cells. The supernatant after centrifugation was discarded, and the algal cell pellet was left in a refrigerator (4°C) for 3 days to dry the algal cells. After 3 days, the algal cells were suspended in 45 μL of an isotonic solution (10% sucrose, 20 mM HEPES, pH 7.0) and centrifuged (1,500×g, 3 minutes), and the supernatant and precipitate were collected. In addition, Cyanidium caldarium RK-1, an algae belonging to the class Polytrichum commune with a strong cell wall, was cultivated and subjected to the same drying and swelling treatment as above, and a centrifugal supernatant and a precipitate were obtained.
[0199] (SDS-polyacrylamide gel electrophoresis (SDS-PAGE)) To prepare a sample for SDS-PAGE, 15 μL of 4×SDS-PAGE sample buffer was added to the above-mentioned centrifugal supernatant. Also, 60 μL of 1×SDS-PAGE sample buffer was added to the centrifugal precipitate. SDS-PAGE was performed on the supernatant sample and precipitate sample prepared as described above. The gel after SDS-PAGE was stained with Coomassie Brilliant Blue to confirm the proteins in the centrifugal supernatant and precipitate.
[0200] The results are shown in Figure 5. In Cyanidioschyzon melorae 10D, multiple types of proteins were detected in both the supernatant and precipitate after the dry swelling treatment. This result confirmed that the cells of Cyanidioschyzon melorae 10D undergo cell rupture upon dry swelling treatment. On the other hand, in Cyanidium caldarium RK-1, no proteins were detected in the supernatant after dry swelling treatment. This result indicates that the cells of Cyanidium caldarium RK-1 do not undergo cell rupture upon dry swelling treatment.
[0201] [Example 4] Isolation of novel microalgae (Isolation of new microalgae) High-temperature acidic water was collected from a hot spring in Yufu City, Oita Prefecture, Japan. Similarly, high-temperature acidic water was collected from a hot spring in Hakone Town, Ashigarashimo District, Kanagawa Prefecture, Japan. The collected high-temperature acidic water was cultured in M-Allen medium (40°C, pH 2.0, 100 μmol / m 2 The YFU3 strain was isolated from the high-temperature acidic water collected in Yufu City, and the HKN1 strain was isolated from the high-temperature acidic water collected in Hakone Town. The composition of M-Allen medium (hereinafter also referred to as "MA medium") is shown in Table 10.
[0202] [Table 10]
[0203] (Isolation of haploid algae) The HKN1 strain, isolated from high-temperature acidic water collected in Hakone Town, was statically cultured in M-Allen medium for approximately one month (40°C, 2% CO 2 After approximately one month of culture, the proliferation phase had ended and the cells had entered the stationary phase. When the culture medium of the HKN1 strain was observed at the stationary phase, small Cyanidioschyzon melorae-like cells were confirmed in all cultures. Figure 6(A) shows a photograph (magnification: 600x) of the stationary phase culture medium of the HKN1 strain. In Figure 6(A), the arrow indicates a Cyanidioschyzon melorae-like cell. Under an inverted microscope (CKX41; Olympus), a single C. melorae-like cell was isolated using a Pasteur pipette with a fine tip and statically cultured in 1 mL of hot spring medium or modified MA medium (see Example 7). The hot spring medium was prepared by adding 10 mM (NH 4 ) 2 SO 4 (Hirooka S and Miyagishima SY., Front Microbiol. 2016 Dec 20;7:2022.) After growth in hot spring medium, the cells that entered stationary phase were maintained in M-Allen medium or MA2 medium (Ohnuma M et al. Plant Cell Physiol. 2008 Jan;49(1):117-20.). Figure 6(B) shows a photograph (magnification: 600x) of C. melorae-like cells isolated from the stationary phase culture of HKN1 strain. The C. melorae-like cells maintained their C. melorae-like cell morphology even after continued cultivation.
[0204] To confirm the relationship between the isolated Cyanidioschyzon merolae-like cells and the HKN1 strain, we performed sequence analysis of a region of the genome for these cells using MiSeq (Illumina). As a result, it was confirmed that the Cyanidioschyzon merolae-like cells (HKN1-derived schizont-like cells) isolated from the stationary-phase culture medium of the HKN1 strain each had only one allele sequence for the analyzed region and were haploid cells. On the other hand, the HKN1 strain had two allele sequences for the analyzed region and were diploid cells. Similarly, the allele sequence of the HKN1-derived schizont-like cells was a crossover sequence of two allele sequences of HKN1. Figure 7 shows two allele sequences of the HKN1 strain (HKN1_allele 1: SEQ ID NO: 12, HKN1_allele 2: SEQ ID NO: 13) and an allele sequence of the HKN1 strain-derived schizon-like cell (HKN1 schizon-like_allele 1: SEQ ID NO: 14). In Figure 7, the arrowheads indicate bases where polymorphism is observed between alleles. These results confirmed that the HKN1-derived schizont-like cells were haploid cells generated by meiosis of the diploid HKN1 strain.
[0205] The YFU3 strain isolated from high-temperature acidic water collected in Yufu City was a cyanidioschyzon-like cell and a haploid cell.
[0206] Hereinafter, diploid cells of the YFU3 strain will be referred to as "YFU strain (diploid)", schizont-like cells derived from the haploid YFU3 strain will be referred to as "YFU3 strain (haploid)", and when referring to both collectively, they will be referred to as "YFU3 strain". Furthermore, diploid cells of the HKN1 strain will be referred to as HKN1 strain (diploid), schizont-like cells derived from the haploid HKN1 strain will be referred to as HKN1 strain (haploid), and when referring to both collectively, they will be referred to as "HKN1 strain".
[0207] Micrographs (magnification: 600x) of YFU3 strain (haploid) and HKN1 strain (haploid), as well as other Cyanidium species, taken under a microscope (BX51; Olympus) are shown in Figure 8. In Figure 8, (A) is a micrograph of Galdieria sulphuraria 074, (B) is a micrograph of Cyanidium caldarium RK-1, (C) is a micrograph of Cyanidioschyzon merolae 10D, (D) is a micrograph of YFU3 strain (haploid), and (E) is a micrograph of HKN1 strain (haploid). The scale bar in Figure 3 represents 5 μm. Galdieria sulphuraria 074 (Fig. 8A) and Cyanidium caldarium RK-1 (Fig. 8B) have a strong cell wall and grow by forming endospores within the mother cell wall. On the other hand, YFU3 (haploid) (Fig. 8D) and HKN1 (haploid) (Fig. 8E) did not have a strong cell wall and grew by binary fission, similar to Cyanidioschyzon melorae 10D (Fig. 8C). The cell size of both YFU3 (haploid) and HKN1 (haploid) was approximately 2 μm.
[0208] (Size comparison of ribosomal DNA ITS1) The size of ribosomal DNA ITS1 was compared between YFU3 strain (haploid), HKN1 strain (haploid), and Cyanidioschyzon melorae 10D. DNA was extracted from cells of YFU3, HKN1, and Cyanidioschyzon melorae 10D, and ribosomal DNA ITS1 was amplified by PCR. The amplified ITS1 fragments were subjected to agarose gel electrophoresis to compare the size of ITS1 from each microalga. The primers used for ITS1 amplification are as follows: Forward primer: TAGAGGAAGGAGAAGTCGTAA (SEQ ID NO: 15) Reverse primer: TTGCGTCAAAGACTCGATGATTC (SEQ ID NO: 16)
[0209] The results of agarose gel electrophoresis are shown in Figure 9. As shown in Figure 9, the size of ITS1 in both YFU3 strain (haploid) and HKN1 strain (haploid) was approximately 1.5 kb. In addition, the size of ITS1 in both YFU3 strain (haploid) and HKN1 strain (haploid) was larger than that of ITS1 in Cyanidioschyzon melorae 10D.
[0210] (Phylogenetic analysis based on rbcL gene sequences) The rbcL gene was amplified by PCR using DNA extracted from the cells of YFU3 strain (haploid) and HKN1 strain (haploid) as a template, and sequence analysis was performed. The nucleotide sequences of the rbcL gene of YFU3 strain (haploid) and HKN1 strain (haploid) are shown in SEQ ID NOs: 1 and 2, respectively. The sequences of the primers used for amplifying rbcL are as follows: Forward primer: aaaactttccaaggrccwgc (SEQ ID NO: 17) Reverse primer: gcwgttggtgtytchacwaaatc (SEQ ID NO: 18)
[0211] Based on the base sequences of the rbcL gene of the YFU3 strain (haploid) and the HKN1 strain (haploid), a molecular phylogenetic analysis was performed using the maximum likelihood method. The molecular phylogenetic tree based on the base sequences of the rbcL gene is shown in Figure 10.
[0212] From the results of the above molecular phylogenetic analysis, it was determined that the YFU3 and HKN1 strains belong to the genus Cyanidium.
[0213] (Cultivation of YFU3 strain (haploid) and HKN1 strain (haploid) in acidic hot spring drainage medium) We confirmed whether the YFU3 strain (haploid) and the HKN1 strain (haploid) could be cultured in an acidic hot spring drainage medium. The acidic hot spring drainage from Tsukahara Onsen or Tamagawa Onsen was used. The acidic hot spring drainage from Tsukahara Onsen or Tamagawa Onsen was supplemented with 10 mM (NH 4 ) 2 SO 4 Alternatively, 10 mM (NH 4 )2 SO 4 , and 2 mM KH as a phosphorus source. 2 PO 4 The YFU3 strain (haploid) or HKN1 strain (haploid) was aerated and cultured in 50 mL of acidic hot spring drainage medium. The culture temperature was 40°C and the medium was illuminated with continuous white light (100 μmol / m 2 The culture was carried out for 2 weeks under the conditions of As a result, the YFU3 strain (haploid) and the HKN1 strain (haploid) could be cultured in both acidic hot spring drainage media.
[0214] [Example 5] Nutritional component analysis of novel microalgae The YFU3 strain (haploid) was cultured in 5 L of M-Allen medium under aeration. The culture temperature was 35°C and the light was continuous white light (500 μmol / m 2 The culture was carried out for 2 weeks under the conditions of
[0215] The cells of the YFU3 strain (haploid) cultured as described above were collected by centrifugation and subjected to component analysis by the Japan Food Analysis Center, Inc. The analysis value per wet weight obtained by the component analysis was converted to a value per dry weight by dividing by 0.248. The analytical methods for each component are as shown in Tables 2 and 3 above.
[0216] The results of the component analysis are shown in Tables 11 and 12. Table 11 shows the analysis results of amino acids, and Table 12 shows the analysis results of vitamins. For reference, Tables 11 and 12 also show published analytical values for Chlorella, Euglena, and Spirulina.
[0217] [Table 11]
[0218] [Table 12]
[0219] As shown in Table 11, it was revealed that the YFU3 strain (haploid) has a higher total amino acid content than other algae that are conventionally used in foods, etc. In addition, the YFU3 strain (haploid) also tended to have a higher content of each amino acid than other algae. It was also confirmed that the YFU3 strain (haploid) contains γ-aminobutyric acid. γ-aminobutyric acid functions as an inhibitory neurotransmitter, and is known to have effects such as improving brain function, lowering blood pressure, and sedative effects. Tomatoes are known to be a food that contains a lot of γ-aminobutyric acid, and it has been reported that the γ-aminobutyric acid content of tomatoes is 0.062g / 100g wet weight (Understanding the increasingly popular supplements - for use by patients with renal failure [Special Discussion] 8 GABA, Clinical Dialysis Vol. 24. No. 13, December 2008). It can be said that the γ-aminobutyric acid content of the YFU strain (haploid) is comparable to that of tomatoes.
[0220] As shown in Table 12, the YFU3 strain (haploid) tended to contain more vitamins than other algae. In particular, the YFU3 strain had higher vitamin C, β-carotene, vitamin E, and vitamin K contents than other algae. 1 , Vitamin K 2 , and had a high folic acid content. Almonds are known to be a food rich in vitamin E, and the vitamin E content of almonds has been reported to be 30.3 mg / 100 g wet weight (Standard Tables of Food Composition in Japan, 2015 edition). Natto is known to be a food rich in vitamin K, and the vitamin K content of natto has been reported to be 600 μg / 100 g wet weight (Standard Tables of Food Composition in Japan, 2015 edition). The vitamin E and vitamin K content of the YFU strain is higher than those of these foods.
[0221] From the above results, it was confirmed that the YFU3 strain (haploid) has a higher content of nutritional components such as amino acids and vitamins compared to other algae that are traditionally used for food, etc.
[0222] [Example 6] Transformation of novel microalgae (YFU3 strain) (Preparation of transformation fragments) The transformation fragment was prepared by the method described in Fujiwara et al. (Front Plant Sci. 2017 Mar 14; 8: 343). The primers used to prepare the transformation fragment are shown in Table 13. Hereinafter, the primers used are described by the primer numbers in Table 13.
[0223] [Table 13]
[0224] <Construction of CAT vector for transformation of C. melorae> In the APCC ORF (CMO250C) of Cyanidioschyzon merolae, nucleotides 1 to 180 encoding a chloroplast transit sequence (60 amino acids) were amplified by PCR using primer set No. 1 / No. 2 with the genomic DNA of Cyanidioschyzon merolae 10D as a template. Also, downstream nucleotides (200 bp, βt3’) of the β-tubulin ORF of Cyanidioschyzon merolae were amplified by PCR using primer set No. 3 / No. 4 with the genomic DNA of Cyanidioschyzon merolae 10D as a template. The CAT ORF was amplified by PCR using primer set No. 5 / No. 6 with pC194 (pC194, Gene ID: 4594904; chloramphenicol acetyltransferase gene of Staphylococcus aureus) as a template. The sequence encoding the chloroplast transit sequence of APCC, the CAT ORF, and the downstream sequence of β-tubulin were cloned into pD184-O250-EGFP-URACm-Cm (Fujiwara et al., PLoS One. 2013 Sep 5;8(9):e73608) amplified using primer set No. 7 / No. 8 using the InFusion Cloning Kit (TAKARA) to construct plasmid pD184-CAT. Using plasmid pD18 as a template, a DNA fragment was amplified by PCR using primer set No. 9 / No. 10 to prepare a CAT vector for transformation of Cyanidioschyzon merolae.
[0225] <Preparation of a CAT Vector for Transformation of Novel Microalgae> Using the plasmid pD18 prepared above as a template, a DNA fragment was amplified by PCR using primer set No. 11 / No. 12 to prepare a CAT vector for transformation of novel microalgae.
[0226] (Transformation) Transformation was performed using a modified method described by Ohnuma M et al. (Plant Cell Physiol. 2008 Jan;49(1):117-20.). Cyanidioschyzon melorae 10D and YFU3 strain (haploid) were used as parent strains for transformation. Cells of each parent strain were diluted in 50 mL of MA2U medium (MA2 medium containing 0.5 mg / mL uracil) to a concentration of OD750 = 0.3 and incubated under continuous light (100 μmol / m 2 The cells were cultured for 19 hours under aeration (600 mL ambient air / min) at 37 °C for 1 min. Then, Tween-20 was added to the culture medium to a final concentration of 0.002%, and the cells were harvested by centrifugation (2,000 g, 5 min). The harvested cells were suspended in 270 μL of MA2U medium. Transformation was performed using a protocol using polyethylene glycol (PEG). 0.6 g of PEG4000 (Aldrich, #81240) was dissolved in 450 μL of MA2U medium (95° C., 10 min) to prepare a 60% (w / v) PEG4000 solution. The PEG4000 solution was then kept at 42° C. on a heat block until use. 4 μg of each CAT vector prepared above for transformation was dissolved in 90 μL of water. 90 μL of vector solution, 10 μL of 10xTF solution (400 mM (NH 4 ) 2 SO 4 , 40 mM MgSO 4 , 0.3% H 2 SO 4 ) and 100 μL of PEG4000 solution were mixed by pipetting in a 1.5 mL tube. Then, 25 μL of the cell suspension was added to 200 μL of the TF-CAT vector-PEG4000 mixture, inverted upside down 3 to 4 times to mix, and immediately transferred to 40 mL of MA2U medium and exposed to continuous light (100 μmol / m 2s) While aerating (300 mL ambient air / min), it was cultured for 1 day. Then, the cells were collected by centrifugation (1,500 g, 5 minutes) and suspended in 2 mL of MA2U medium. The cells were cultured in a 24-well plate (TPP Techno Plastic Products AG) under continuous light, 42 °C, 5% CO 2 Under the conditions of, it was cultured for 2 - 3 days. Then, chloramphenicol (CP) was added to the culture solution and cultured for 10 days to select CP-resistant transformants. The CP-resistant transformants were washed with CP-free MA2U medium and serially diluted, and spotted on a starch bed on an MA2U agar plate. The starch bed and the MA2U agar plate were prepared by a method described in Imamura S et al (Plant Cell Physiol. 2010 May;51(5):707 - 17) with minor modifications (Fujiwara et al., PLoS One. 2013 Sep 5;8(9):e73608). The plates were incubated in a 5% CO 2 incubator for 2 weeks until colonies appeared. The colonies were transferred to a starch bed on a new MA2U medium plate according to the method described in Fujiwara et al. (PLoS One. 2013 Sep 5;8(9):e73608).
[0227] (Evaluation of Chloramphenicol (CP) Resistance) After the above transformation, CP-resistant transformants of Cyanidioschyzon merolae 10D and YFU3 strains (haploid) were selected by culturing in MA2 liquid medium supplemented with CP. To evaluate the CP resistance concentration of each CP-transformed strain, the wild type (WT) and the transformant (TF) were cultured in MA2 liquid medium containing each concentration (0, 50, 100, 150, 200, 250 μg / mL) of CP for 10 days.
[0228] The results are shown in Figure 11. In Figure 11, 10D_TF and 10D_WT represent the CP-resistant transformant and wild-type strain of Cyanidium Schizon melorae 10D, respectively. Additionally, YFU3_TF and YFU3_WT represent the CP-resistant transformant and wild-type strain of the YFU3 strain (haploid), respectively. As shown in Figure 11, in both Cyanidium Schizon melorae 10D and the YFU3 strain (haploid), the CP-resistant transformant showed resistance to a higher CP concentration than the wild-type strain.
[0229] In addition, in order to confirm the introduction of the CAT gene into the cells cultured in Figure 11, primers were designed for the 5'-terminal sequence of the chloroplast targeting sequence of APCC and the 3'-terminal sequence of the CAT ORF. The primer sequences are as follows. APCC(1) forward primer: ATGTTCGTTCAGACCAGTTTCTTT (SEQ ID NO: 31) CAT(650) reverse primer: TAAAAGCCAGTCATTAGGCCTA (SEQ ID NO: 32)
[0230] In Figure 11, the cells of CP-resistant transformants (TF_0, TF_150) of Cyanidium Schizon mellorae 10D cultured with 0 μg / mL or 150 μg / mL of CP, and the cells of CP-resistant transformants (TF_0, TF_100) of YFU3 strain (haploid) cultured with 0 μg / mL or 100 μg / mL of CP were collected and subjected to PCR using the above primer set. Then, agarose gel electrophoresis was performed to confirm the presence or absence of PCR-amplified fragments.
[0231] The results are shown in Figure 12. In Figure 12, "w / o TF" indicates cells that were not transformed (wild type). As shown in Figure 12, in the CP-resistant transformants of YFU3 strain (haploid), the amplified fragment of the CAT gene was confirmed regardless of whether the transformants were cultured at a CP concentration of 0 μg / mL or 100 μg / mL. On the other hand, in C. melorae, the amplified fragment of the CAT gene was confirmed in the transformants cultured at a CP concentration of 150 μg / mL, but not in the transformants cultured at a CP concentration of 0 μg / mL. In C. melorae, it is believed that the introduced CAT gene was lost due to culture in the absence of CP. These results indicate that the YFU3 strain (haploid) can be transformed, as can C. melorae.
[0232] [Example 7] Transformation of novel microalgae (HKN1 strain) (Preparation of transformation fragments) The primers used to prepare the transformation fragments are shown in Table 14. Hereinafter, the primers used will be described with the primer numbers shown in Table 14.
[0233] [Table 14]
[0234] <Construction of a new CAT vector for microalgae transformation> A construct for introducing a gene upstream of the URA5.3 gene was prepared as follows. A DNA fragment of the upstream sequence (-2500 to -501) of the URA5.3 gene was amplified by PCR using the genomic DNA of the HKN1 strain as a template and primer set No. 1 / 2. The PCR-amplified fragment was then subcloned into pUC19 using the In-Fusion HD Cloning Kit. The resulting vector was designated as the pURA5.3up vector. Next, a DNA fragment of the upstream sequence of APCC (-500 to -1) was amplified by PCR using the genomic DNA of the HKN1 strain as a template and primer set No. 3 / 4. In addition, mVenus ORF (synthesized by Integrated DNA Technologies, Inc.) was amplified by PCR using primer set No. 5 / 6. In addition, a DNA fragment of the downstream sequence of β-tubulin (+1 to +250) was amplified by PCR using the genomic DNA of the HKN1 strain as a template and primer set No. 7 / 8. The three PCR-amplified fragments were subcloned into pUC19 using the In-Fusion HD Cloning Kit. The resulting vector was designated as pmVenus vector. Next, the DNA fragment of the upstream sequence of CPCC (-500 to -1) was amplified by PCR using the genomic DNA of the HKN1 strain as a template and primer set No. 9 / 10. The DNA fragment of the organelle transport sequence of POP was amplified by PCR using the genomic DNA of Cyanidioschyzon mellorae 10D as a template and primer set No. 11 / 12. The CAT ORF (synthesized by Integrated DNA Technologies Co., Ltd.) was amplified by PCR using primer set No. 13 / 14. The DNA fragment of the downstream sequence of ubiquitin (+1 to +250) was amplified by PCR using the genomic DNA of the HKN1 strain as a template and primer set No. 15 / 16. The four PCR-amplified fragments were subcloned into pUC19 using the In-Fusion HD Cloning Kit. The resulting vector was named pCAT vector. Subsequently, using the pmVenus vector as a template, a DNA fragment was amplified by PCR using primer set No. 17 / 18. Also, using the pCAT vector as a template, a DNA fragment was amplified by PCR using primer set No. 19 / 20. Furthermore, the pURA5.3up vector was amplified by PCR using primer set No. 21 / 22. Next, the amplified fragment of the pmVenus vector and the amplified fragment of the pCAT vector were cloned into the pURA5.3up vector amplified as described above using the In-Fusion HD Cloning Kit. Using the resulting pURA5.3up-mVenus-CAT vector as a template, a DNA fragment was amplified by PCR using primer set No. 23 / 24. This amplified DNA fragment was used as a transformation CAT vector. The structure of the transformation CAT vector is shown as a PCR Product in Fig. 13.
[0235] (Transformation) Transformation was carried out by modifying the method described by Ohnuma M et al (Plant Cell Physiol. 2008 Jan;49(1):117-20.). The HKN1 strain (haploid) was used as the parent strain for transformation. The cells of the parent strain were diluted in 50 mL of MA2U medium (MA2 medium containing 0.5 mg / mL uracil) to a concentration of OD750 = 0.3, and cultured for 60 hours with aeration (600 mL ambient air / min) under a light-dark cycle (12L:12D), light (50 μmol / m 2 s), and temperature (42°C). Subsequently, Tween-20 was added to the culture solution to a final concentration of 0.002%, and the cells were then collected by centrifugation (2,000 g, 5 minutes). The collected cells were suspended in 270 μL of MA2U medium. Transformation was carried out according to the protocol using polyethylene glycol (PEG). 0.6 g of PEG4000 (Aldrich, #81240) was dissolved in 450 μL of MA2U medium (95°C, 10 minutes) to prepare a 60% (w / v) PEG4000 solution. Thereafter, the PEG4000 solution was maintained at 42°C on a heat block until use. 4 μg of CAT vector for transformation was prepared in 90 μL of water. 90 μL of vector solution, 10 μL of 10xTF solution (400 mM (NH 4 ) 2 SO 4 , 40 mM MgSO 4 , 0.3% H 2 SO 4 ) and 100 μL of PEG4000 solution were mixed by pipetting in a 1.5 mL tube to prepare a TF-CAT vector-PEG4000 mixture. Next, 25 μL of the cell suspension was added to 200 μL of the TF-CAT vector-PEG4000 mixture, stirred by inverting upside down 3 to 4 times, and immediately transferred to 10 mL of MA2U medium and cultured stationarily for 2 days under continuous light (20 μmol / m2s) and temperature (42°C). Thereafter, the cells were recovered by centrifugation (1,500 g, 5 min) and suspended in 1 mL of Tsukahara mineral spring medium or modified MA medium. 100 μL of the cell suspension was added to 1 mL of Tsukahara mineral spring medium or modified MA medium containing 100 μg / mL of CP, and cultured in a 24-well plate (TPP Techno Plastic Products AG) under continuous light (20 μmol / m2s), 42°C, 3% CO 2 The dark green parts were added to 1 mL of fresh Tsukahara mineral spring medium or modified MA medium containing 100 μg / mL CP, and cultured for an additional 7 days to select CP-resistant transformants. The CP-resistant transformants were isolated as single cells using a fine-tipped Pasteur pipette under an inverted microscope (CKX41; Olympus), and cultured statically in 1 mL of Tsukahara mineral spring medium or modified MA medium. The composition of the modified MA medium is shown in Table 15.
[0236] [Table 15]
[0237] (Confirmation of transformants) Primers were designed to confirm that the mVenus-CAT gene had been introduced into the desired location in the cells of the isolated and cultured CP-resistant transformant (see FIG. 13; the approximate locations of the primers are indicated by arrows in the lower diagram (genome) of FIG. 13). The primer sequences are as follows: Forward primer: CATTGCACAGCAATGAAAAGCG (SEQ ID NO: 87) Reverse primer: ATCGAAACTGCGTAGATAGTGTCGG (SEQ ID NO: 88)
[0238] The CP transformant cells were harvested, and PCR was carried out using the above primer set, followed by agarose gel electrophoresis. The results are shown in Figure 14. In the wild type (WT), an amplified fragment was observed at approximately 2.5 kb, but in the CP-resistant transformed strain (TF), an amplified fragment was detected at approximately 5.5 kb. From this result, it was confirmed that the mVenus-CAT gene was inserted at the desired location (see Figure 13) in the transformed strain (TF). These results demonstrated that gene targeting is possible in HKN1 (haploid).
[0239] Furthermore, the CP-resistant transformed strains were observed using a fluorescence microscope to confirm whether green fluorescence of mVenus was observed. The results are shown in FIG. 15. In FIG. 15, the left image (mVenus) is a fluorescence micrograph in which mVenus fluorescence was detected, the middle image (Chl) is a fluorescence micrograph in which chloroplast autofluorescence was detected, and the right image (merged) is a merge of the two fluorescence micrographs. As shown in FIG. 15, in the CP-resistant transformed strains, mVenus was expressed in the cytoplasm, and green fluorescence was detected. These results demonstrated that HKN1 (haploid) is capable of expressing foreign genes.
[0240] [Example 8] Cell rupture treatment of YFU3 strain and HKN1 strain (Drying and swelling treatment of algae cells) YFU3 strain (haploid), HKN1 strain (haploid), and HKN1 strain (diploid) were cultured in the same manner as in Example 5, and 1 mL of the culture solution was centrifuged (1,500×g, 2 minutes). The supernatant after centrifugation was discarded, and the precipitate of the algal cells was suspended in an isotonic solution (10% sucrose, 20 mM HEPES, pH 7.0), and centrifuged (1,500×g, 3 minutes) to wash the algal cells. The supernatant after centrifugation was discarded, and the precipitate of the algal cells was left in a refrigerator (4° C.) for 3 days to dry the algal cells. After 3 days, the algal cells were suspended in 45 μL of an isotonic solution (10% sucrose, 20 mM HEPES, pH 7.0) and centrifuged (1,500×g, 3 minutes), and the supernatant and precipitate were collected. In addition, Cyanidium caldarium RK-1 was cultivated as a control for algae with strong cell walls, and Cyanidium schizont melorae 10D was cultivated as a control for algae without strong cell walls, and the same drying and swelling process was carried out as above to obtain the centrifugal supernatant and precipitate.
[0241] (SDS-polyacrylamide gel electrophoresis (SDS-PAGE)) To prepare a sample for SDS-PAGE, 15 μL of 4×SDS-PAGE sample buffer was added to the above-mentioned centrifugal supernatant. Also, 60 μL of 1×SDS-PAGE sample buffer was added to the centrifugal precipitate. SDS-PAGE was performed on the supernatant sample and precipitate sample prepared as described above. The gel after SDS-PAGE was stained with Coomassie Brilliant Blue to confirm the proteins in the centrifugal supernatant and precipitate.
[0242] The results are shown in Figure 16. In the case of YFU3 (haploid), HKN1 (haploid), and Cyanidioschyzon melorae 10D, multiple types of proteins were detected in both the supernatant and precipitate after the dry swelling treatment. This result confirmed that YFU3 (haploid), HKN1 (haploid), and Cyanidioschyzon melorae 10D cause cell rupture due to dry swelling treatment. On the other hand, in the case of HKN1 (diploid) and Cyanidium caldarium RK-1, no proteins were detected in the supernatant after dry swelling treatment. This result indicates that the cells of HKN1 (diploid) and Cyanidium caldarium RK-1 do not cause cell rupture due to dry swelling treatment.
[0243] [Example 9] Creation of diploids by crossing haploids (HKN1 strain (haploid) cross with another) HKN1 strain No. 1 and No. 5 were mixed and grown in MA medium at 40°C and 50 μmol / m 2 s, light-dark cycle (12L:12D), 2% CO 2 The algal cells were cultured for three weeks under the above culture conditions. After three weeks of culture, the cells were transferred to new medium (diluted 20-fold) and cultured for one week. The algal cells were then observed under a microscope. As a result, diploid-like cells with strong cell walls were confirmed (Figure 17A). The diploid-like cells were harvested and stained with DAPI to quantify the fluorescence intensity. For comparison, HKN1 strain (haploid) was also stained with DAPI. The results are shown in Figure 17B. As shown in FIG. 17B, the diploid-like cells showed twice the fluorescence intensity compared to the haploid strain. This result confirmed that the diploid-like cells were diploid. These results demonstrated that diploid cell morphology can be produced by mixing and culturing haploid cell morphologies.
[0244] (Mixture of YFU3 strains (haploid)) The same procedure was carried out on the YFU3 strain (haploid), and the appearance of diploid cell morphology was confirmed by optical microscopy.
[0245] [Example 10] Preparation of haploid cell morphology of algae belonging to the genus Galderia (Creation of a cell morphology without a strong cell wall: G. sulphuraria) (Method (a)) One milliliter of Tsukahara mineral spring medium (Hirooka et al. 2016 Front in Microbiology) or modified MA medium was placed in a 24-well plate, and approximately 10 Galdieria sulphuraria SAG108.79 cells were placed in each well. The plate was incubated at 42°C under 50 μmol / m light. 2 s,CO 2 The cells were cultured for one week at 2%. Tadpole-like cells and round cells were mixed in this medium. Using a Pasteur pipette with a fine tip, tadpole-like cells were isolated under a microscope and further cultured in MA medium at 42°C and 50 μE / m light. 2 S,CO 2 The cells were cultured at 2%.
[0246] (Method (b)) (Three-stage culture) Galdieria sulphuraria SAG108.79 was cultured in MA medium until it reached a plateau, and a group of cells was taken from the culture, diluted 100-fold, and then subcultured in MA medium. After 3 days of culture, tadpole-like cells appeared. Tadpole-like cells were isolated from the culture medium under a microscope using a Pasteur pipette with a fine tip, and further cultured in MA medium at 42°C and 50 μE / m light. 2 S,CO 2 The cells were cultured at 2%. FIG. 18A shows normal cell morphology of Galdieria sulphuraria SAG108.79 (left panel) and cell morphology without a strong cell wall observed after culturing the cells (right panel).
[0247] (Creation of a cell morphology without a strong cell wall: G.partita) A haploid was produced using Galdieria partita NBRC 102759 (obtained from NITE Biological Resource Center) instead of Galdieria sulphuraria SAG108.79 in a similar manner to the above (method (a)). Figure 18B shows the normal cell morphology of Galdieria partita NBRC 102759 (left panel) and the cell morphology without a strong cell wall confirmed after culturing the cell (right panel).
[0248] (Optical microscope observation) In both of the above cultures, the cells without strong cell walls could be easily disrupted by freezing and thawing, and the cell contents could be extracted. The cells without strong cell walls that appeared during the culture of algae belonging to the genus Galderia were a mixture of tadpole-like cells and round cells. In the left images of Figures 18A and 18B, the arrows indicate what is thought to be the mother cell wall shed after meiosis.
[0249] (Allele analysis) Cells with a cell morphology that does not have a strong cell wall that emerged during the cultivation of Galdieria sulphuraria SAG108.79 were collected, a region of genomic DNA was amplified by PCR, and sequence analysis was performed by the Sanger method. For comparison, the same region was also sequenced for cells with a cell morphology that has a strong cell wall. The results are shown in Figure 19. The cell morphology with a strong cell wall had two types of allele sequences (2N_allele1 (SEQ ID NO: 61) and 2N_allele2 (SEQ ID NO: 62)). On the other hand, the cell morphology without a strong cell wall had only either 2N_allele1 or 2N_allele2. This result confirmed that the cell morphology without a strong cell wall was haploid. Therefore, it was shown that algae belonging to the genus Garderia also have diploid and haploid cell morphologies.
[0250] Hereinafter, the diploid and haploid strains of Galdieria sulphuraria SAG108.79 will be referred to as SAG108.79 (diploid) and SAG108.79 (haploid), respectively. The diploid and haploid strains of Galdieria partita NBRC 102759 will be referred to as NBRC 102759 strain (diploid) and NBRC 102759 (haploid), respectively.
[0251] [Example 11] Cell rupture treatment of algae belonging to the genus Galderia Cell rupture treatment was performed in the same manner as in Example 8, except that SAG108.79 (diploid), SAG108.79 (haploid), NBRC 102759 strain (diploid) and NBRC 102759 (haploid) were used instead of YFU3 strain (haploid) and the like. SDS-PAGE was then performed in the same manner as in Example 8. The gel after SDS-PAGE was stained with Coomassie Brilliant Blue to confirm the proteins in the centrifugation supernatant and precipitate.
[0252] The results are shown in FIG. 20. In SAG108.79 (haploid) and NBRC 102759 strain (haploid), multiple types of proteins were detected in both the supernatant and precipitate after the dry swelling treatment. This result confirmed that SAG108.79 (haploid) and NBRC 102759 strain (haploid) cause cell rupture due to the dry swelling treatment. On the other hand, in SAG108.79 (diploid) and NBRC 102759 strain (diploid), no proteins were detected in the supernatant after the dry swelling treatment. This result indicates that the cells of SAG108.79 (diploid) and NBRC 102759 strain (diploid) do not cause cell rupture due to the dry swelling treatment.
[0253] [Example 12] Preparation of strains with enhanced vitamin production (Preparation of transformed strains) The procedure of Example 2 was repeated except that a DNA fragment in which a 3×HA tag was added to the 3′ end of CML326C (tocopherol cyclase: TC) from Cyanidioschyzon melorae was used instead of EGFP ORF. <EGFP / URA Cm-CmIn the same manner as in "Creation of the fragment >", Cm-Cm In addition, the upstream sequence of CMP166C (-500 to -1), CMN202C (homogentisic acid phytyltransferase: HPT) with a 3×FLAG tag added to the 3' end, and the downstream sequence of CMK296C (+1 to +278) were amplified by PCR and cloned into pD184-O250-TC-URA using the In-Fusion HD Cloning Kit. Cm-Cm URA Cm-Cm The selection marker was introduced downstream of pD184-O250-VE-URA Cm-Cm A vector was prepared. pD184-O250-VE-URACm-Cm vector was used as a template to generate VE / URA Cm-Cm The fragment was amplified by PCR. Cm-Cm The DNA fragment (VE / URA fragment) was used for transformation. Cm-Cm The composition of the DNA fragment (VE / URA Cm-Cm The uracil auxotrophic mutant, C. melorae M4, was transformed with the α-amino acid sequence fragment (A fragment of the α-amino acid sequence fragment). Transformation and post-transformation culture were performed in the same manner as in Example 2. Immunoblotting was then performed using anti-HA or anti-FLAG antibodies in the same manner as in Example 2.
[0254] The results are shown in Figure 22. The left panel shows the results of immunoblotting using an anti-HA antibody, and the right panel shows the results of immunoblotting using an anti-FLAG antibody. In Figure 22, "GFP" stands for EGFP / URA Cm-Cm Cells transformed with the fragment (Figure 1A) (EGFP / URA Cm-Cm "VE" indicates VE / URA Cm-Cm Cells transformed with the fragment (VE / URA Cm-Cm Fragment transformants) are shown. From the results in Figure 22, VE / URA Cm-CmThe fragment transformant was confirmed to express tocopherol cyclase and homogentisate phytyltransferase.
[0255] (Measurement of intracellular vitamin E content in transformed strains) EGFP / URA Cm-Cm Fragment transformants and VE / URA Cm-Cm The fragment transformant was grown in MA2 medium. The culture was performed under continuous white light at 40°C. After the culture, the cells were collected by centrifugation, and soluble matter was extracted from the collected cells with 75% ethanol. Vitamin E in the extracted soluble matter was quantified. The vitamin E quantification was entrusted to the Japan Food Analysis Center, a general incorporated foundation, and was performed by high performance liquid chromatography.
[0256] The results are shown in Table 16. In Table 16, EGFP / URA Cm-Cm The vitamin E concentration (per dry cell weight) in the fragment transformant was expressed as a relative value, assuming it to be 1.0.
[0257] [Table 16]
[0258] As shown in Table 16, VE / URA Cm-Cm In the fragment transformants, the negative control EGFP / URA Cm-Cm The vitamin E concentration was higher than that of the fragment-transformed strain. This result confirmed that the intracellular concentration of vitamin E can be increased by transformation of C. melorae. [Industrial Applicability]
[0259] According to the present invention, a novel microalgae that can be used industrially and its use are provided. The novel microalgae provided by the present invention can be used in nutritional component compositions, nutrients, nutritional component supplement compositions, and methods for producing nutritional components. Alternatively, the novel microalgae provided by the present invention can be used in various processed foods, functional foods, nutritional supplements, and other foods, feed, pet foods, cosmetics, and the like. The present invention also provides a nutritional composition or a nutritional agent rich in nutritional components such as amino acids, vitamins, etc. The nutritional composition or the nutritional agent can be used in foods such as various processed foods, functional foods, and nutritional supplements, as well as feed, pet food, cosmetics, etc. The present invention also provides a method for producing nutritional components such as amino acids, vitamins, proteins, lipids, and dietary fiber.
Claims
1. (a) mixing and culturing two or more types of haploid cells of the same algae belonging to the genus Gardellus or Cyanidium, the algae having a diploid cell morphology and a haploid cell morphology; (b) isolating cells having a diploid cell morphology produced during the culture; A method for producing diploid algae.
2. The method for producing diploid algae according to claim 1 , wherein at least one of the cells having the haploid cell form is a transformant.
3. The method for producing a diploid algae according to claim 2 , wherein the transformant is produced by self-cloning.
4. The culture in the step (a) is carried out at a temperature of 15 to 50° C., a pH of 1.0 to 6.0, and CO 2 The method for producing diploid algae according to claim 1 or 2, which is carried out under conditions of a concentration of 1 to 3%.
5. A step of producing diploid algae by the method for producing diploid algae according to claim 1 or 2; Producing a nutritional composition comprising the diploid algae or an extract thereof; A method for producing a nutritional composition comprising the steps of:
6. The method for producing a nutritional component composition according to claim 5 , wherein at least one of the cells having the haploid cell form is a transformant having an increased intracellular content of at least one nutritional component.
7. The method for producing a nutritional composition according to claim 6 , wherein the transformant is produced by self-cloning.
8. The method for producing a nutritional composition according to claim 5 , wherein the nutritional composition contains at least one nutritional component selected from the group consisting of amino acids, vitamins, proteins, lipids, and dietary fibers.
9. A step of producing a nutritional composition by the method for producing a nutritional composition according to claim 5; Producing a food product comprising the nutritional composition; A method for producing a food product, comprising:
10. The method for producing a food product according to claim 9, wherein the food product is a functional food product or a dietary supplement.
11. A step of producing a nutritional composition by the method for producing a nutritional composition according to claim 5; producing a feed or pet food comprising the nutritional composition; A method for producing a feed or pet food comprising the steps of:
12. A step of producing a nutritional composition by the method for producing a nutritional composition according to claim 5; Producing a cosmetic product containing the nutritional ingredient composition; A method for producing a cosmetic product comprising:
13. (a') producing a diploid algae by the method for producing a diploid algae according to claim 1 or 2; (a) disrupting the diploid algal cells to obtain cell disruptants; (b) separating at least one nutrient component from the cell disruption; A method for producing a nutritional ingredient comprising the steps of:
14. The method for producing a nutritional component according to claim 13, wherein the nutritional component is at least one selected from the group consisting of amino acids, vitamins, proteins, lipids, and dietary fibers.
15. The method for producing a nutritional component according to claim 14, wherein the amino acid is at least one selected from the group consisting of isoleucine, leucine, lysine, methionine, cystine, phenylalanine, tyrosine, threonine, tryptophan, valine, arginine, histidine, alanine, aspartic acid, glutamic acid, glycine, proline, serine, and γ-aminobutyric acid.
16. The vitamins are vitamin A, β-carotene, vitamin B 1 , Vitamin B 2 , Vitamin B 6 , Vitamin C, Vitamin E, Vitamin K 1 , Vitamin K 2 15. The method for producing a nutritional component according to claim 14, wherein the nutritional component is at least one selected from the group consisting of niacin, inositol, folic acid, and biotin.
17. The method for producing a nutritional component according to claim 13, wherein at least one of the cells having the haploid cell form is a transformant having an increased intracellular content of at least one nutritional component.
18. The method for producing a nutritional component according to claim 17, wherein the transformant is produced by self-cloning.
Citation Information
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