Microalgae growth promoter

Abstract

To provide a microalgae growth promoter.SOLUTION: A microalgae growth promoter contains at least one compound selected from (1) oxo fatty acid or a derivative thereof or a salt thereof or (2) a hydroxylated fatty acid or a derivative thereof or a salt thereof.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a growth promoter for microalgae. [Background technology]

[0002] Conventionally, microalgae have been grown to produce and store valuable materials such as lipids, which are used as raw materials for fuel, feed, health foods, etc., or proteins and vitamins within the cells of the microalgae, and the stored valuable materials are then used to produce fuel, food, etc.

[0003] Patent Document 1 describes a method for culturing heterotrophic microalgae using a medium containing POME.

[0004] However, in Patent Document 1, it is necessary to use wastewater from palm oil refineries, called POME, and importing such wastewater from Southeast Asia is undesirable from the standpoint of cost and stability of raw material supply. In addition, according to Non-Patent Document 1, POME contains 33% oleic acid (C18: 1 unsaturated bond), 31% palmitic acid (C16: 0 unsaturated bond), and 9% linoleic acid (C18: 2 unsaturated bonds), and the inventors' knowledge shows that such linear saturated and unsaturated fatty acids alone are not sufficient to promote the growth of microalgae. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2020 / 026794 [Non-patent literature]

[0006] [Non-Patent Document 1] Environmental Engineering Research. Vol. 40, 2003 Summary of the Invention [Problem to be solved by the invention]

[0007] In view of the above problems, an object of the present invention is to provide a growth promoter for microalgae that can efficiently grow algae. [Means for solving the problem]

[0008] The present invention relates to a growth promoter for microalgae, which contains at least one compound selected from (1) an oxo fatty acid or a derivative or a salt thereof, or (2) a hydroxylated fatty acid or a derivative or a salt thereof.

[0009] It is preferable that the microalgae growth promoter further contains an unsaturated fatty acid (excluding the oxo fatty acid and the hydroxylated fatty acid).

[0010] The microalgae growth promoter preferably contains an unsaturated fatty acid having 10 to 20 carbon atoms.

[0011] The microalgae growth promoter is preferably an unsaturated fatty acid selected from the group consisting of mono- or polyunsaturated fatty acids such as oleic acid, linoleic acid, α-linolenic acid, γ-linolenic acid, and arachidonic acid.

[0012] The microalgae growth promoter is preferably one in which the unsaturated fatty acid is linoleic acid.

[0013] The oxo fatty acid or a derivative or a salt thereof has the following formula: HOOC-(R 1 )-CH=CH-C(=O)-R 2 (I) (In the formula, R 1 : a linear or branched, saturated or unsaturated hydrocarbon group containing 6 to 12 carbon atoms, R 2 : an alkyl group having 2 to 8 carbon atoms, which may contain one or more branches and / or double bonds) A preferred microalgae growth promoter is an oxo fatty acid having the structural formula:

[0014] The oxo fatty acid is R 1 The hydrocarbon group has 8 to 10 carbon atoms, and R 2 The microalgae growth promoter is preferably an oxo fatty acid having an alkyl group with 4 to 6 carbon atoms.

[0015] The oxo fatty acid is R 1 is an oxo fatty acid that contains a double bond that forms a conjugated double bond with the double bond between the α and β carbons of the carbonyl group in formula (I).

[0016] The oxo fatty acid is R 1 is a linear or branched hydrocarbon group having 9 carbon atoms, R 2 However, a preferred microalgae growth promoter is an oxo fatty acid, which is an alkyl group having 5 carbon atoms.

[0017] The microalgae growth promoter is preferably such that the oxo fatty acid is ketooctadecadienoic acid.

[0018] The microalgae growth promoter is preferably such that the oxo fatty acid is 13-oxo-9,11-octadecadienoic acid.

[0019] The hydroxylated fatty acid or its derivative or salt thereof is represented by the following formula (II) and / or (III): HOOC-(R 3 )-CH(OH)-CH(OH)-CH=CH-CH(OH)-R 4 (II) HOOC-(R 3 )-CH(OH)-CH=CH-CH(OH)-CH(OH)-R 4 (III) (In the formula, R 3is a linear or branched hydrocarbon group having 4 to 12 carbon atoms, which may contain one or more double bonds and / or OH groups, and when it contains a double bond, the position of the double bond is not limited; R 4 is a linear or branched hydrocarbon group having 2 to 8 carbon atoms, which may contain one or more double bonds and / or OH groups, and when it contains a double bond, the position of the double bond is not limited. A preferred microalgae growth promoter is a hydroxylated fatty acid having the structural formula:

[0020] The hydroxylated fatty acid is R 3 The hydrocarbon group has 6 to 8 carbon atoms, and R 4 A growth promoter for microalgae in which the hydrocarbon group has 4 to 6 carbon atoms is preferred.

[0021] The hydroxylated fatty acid is R 3 But -(CH2) n -(n is an integer from 4 to 12), 4 But, C n H 2n+1 A microalgae growth promoter having the structure -(n is an integer of 2 to 8) is preferred.

[0022] The hydroxylated fatty acid is R 3 is an alkylene group having 7 carbon atoms (-(CH2)7-), and R 4 However, a microalgae growth promoter having an alkyl group having 5 carbon atoms (CH3CH2CH2CH2CH2-) is preferred.

[0023] The growth promoter for microalgae is preferably such that the hydroxylated fatty acid is hydroxyoctadecenoic acid.

[0024] The growth promoter for microalgae is preferably such that the hydroxylated fatty acid is 9,10,13-trihydroxy-11-octadecenoic acid.

[0025] The growth promoter for microalgae is preferably such that the hydroxylated fatty acid is 9,12,13-trihydroxy-10-octadecenoic acid.

[0026] In addition, "octadecaenoic acid" is a conventional notation (for example, JP-A-3-14539, etc.), and the above-mentioned "9,10,13-trihydroxy-11-octadecenoic acid" is also written as "9,10,13-trihydroxyoctadec-11-enoic acid" or "9,10,13-trihydroxy-11-octadecenoic acid". Similarly, the above-mentioned "9,12,13-trihydroxy-10-octadecenoic acid" is also written as "9,12,13-trihydroxyoctadec-10-enoic acid" or "9,12,13-trihydroxy-10-octadecenoic acid". In addition, in the examples, the manufacturer's name is also written in parentheses. In addition, the above explanation applies to all "octadecaenoic acid" used in this specification, claims and abstract.

[0027] The structural formula of “9,10,13-trihydroxy-11-octadecenoic acid” is shown in the following structural formula (1).

[0028] [ka]

[0029] The structural formula of “9,12,13-trihydroxy-10-octadecenoic acid” is shown in the following structural formula (2).

[0030] [ka]

[0031] It is preferable that the microalgae growth promoter contains the unsaturated fatty acid such that the ratio of the at least one compound selected from the oxo fatty acid or its derivative or salt thereof and the hydroxylated fatty acid or its derivative or salt thereof to the unsaturated fatty acid is 10% to 90% by weight.

[0032] The derivatives of the oxo fatty acids and hydroxylated fatty acids are preferably esters of oxo fatty acids and hydroxylated fatty acids, respectively. As salts of the oxo fatty acids and hydroxylated fatty acids, salts such as sodium salts, potassium salts, and ammonium salts, which will be described later, can be used.

[0033] The microalgae growth promoter is preferably used as a culture medium for microalgae.

[0034] It is desirable that the microalgae growth promoter is used for at least one species selected from Euglena, Chlorella, and Spirulina.

[0035] Furthermore, it is desirable that the growth promoter for microalgae contains at least one ion selected from potassium ions, carbonate ions, phosphate ions, calcium ions, and sodium ions. Effect of the Invention

[0036] The microalgae growth promoter of the present invention can efficiently grow microalgae. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0037] The microalgae growth promoter of the present invention contains at least one compound selected from (1) an oxo fatty acid or a derivative or a salt thereof, or (2) a hydroxylated fatty acid or a derivative or a salt thereof, as a growth-promoting component. Such oxo fatty acids and hydroxylated fatty acids have a higher microalgae growth-promoting effect than linear saturated fatty acids and unsaturated fatty acids that do not have a hydroxyl group or a carbonyl structure other than the carboxy group.

[0038] In the present invention, microalgae refers to a group of unicellular organisms that mainly exist in water and are classified as algae in a broad sense, and many of them perform photosynthesis. Microalgae may include those classified as green algae, xanthophytes, diatoms, dinoflagellates, unicellular eukaryotic algae, freshwater unicellular green algae, and cyanobacteria. Generally, it refers to microscopic algae, and specifically, it refers to algae with a cell size of about 1 to 500 μm in diameter as measured by the major axis diameter of the cell observed using an optical microscope. Note that microalgae also include those in which a plurality of cells form a colony. The microalgae growth promoter of the present invention can be used to promote the growth of any microalgae known to those skilled in the art, and there is no particular limitation on the type of microalgae to which it is applied.

[0039] The microalgae growth promoter of the present invention may further contain an unsaturated fatty acid in addition to the above-mentioned active ingredient, i.e., at least one compound selected from oxo fatty acids or derivatives or salts thereof and hydroxylated fatty acids or derivatives or salts thereof. The unsaturated fatty acids of the present invention exclude oxo fatty acids and hydroxylated fatty acids. The unsaturated fatty acids that may be contained in the microalgae growth promoter of the present invention have the effect of promoting the absorption of the oxo fatty acids and hydroxylated fatty acids by the microalgae. This is because the cell membrane of microalgae is composed of lipids, and the oxo fatty acids and hydroxylated fatty acids are more likely to permeate the cell membrane if the cell membrane contains the unsaturated fatty acids.

[0040] The oxo fatty acid or a derivative or a salt thereof of the present invention is represented by the following formula: HOOC-(R 1 )-CH=CH-C(=O)-R 2 (I) (In the formula, R 1 A linear or branched, saturated or unsaturated hydrocarbon group containing 6 to 12 carbon atoms. R 2 : an alkyl group having 2 to 8 carbon atoms, which may contain one or more branches and / or double bonds) An oxo fatty acid having the structural formula: or a derivative or salt thereof can be suitably used.

[0041] In one embodiment of the present invention, R in the oxo fatty acid 1 The hydrocarbon group has 8 to 10 carbon atoms, and R 2 The number of carbon atoms in the alkyl group is 4 to 6. In another embodiment, R 1 contains a double bond that forms a conjugated double bond with the double bond between the α and β carbons of the carbonyl group in formula (I). 1 is a linear or branched hydrocarbon group having 9 carbon atoms, and R 2 is preferably an alkyl group having 5 carbon atoms.

[0042] The oxo fatty acid of the present invention specifically includes ketooctadecadienoic acid. For example, ketooctadecadienoic acid includes, but is not limited to, 9-oxo-10,12-octadecadienoic acid (9-oxoODA), 13-oxo-9,11-octadecadienoic acid (13-oxoODA), 5-oxo-6,8-octadecadienoic acid, 6-oxo-9,12-octadecadienoic acid, 8-oxo-9,12-octadecadienoic acid, 10-oxo-8,12-octadecadienoic acid, 11-oxo-9,12-octadecadienoic acid, 12-oxo-9,13-octadecadienoic acid, and 14-oxo-9,12-octadecadienoic acid and their isomers.

[0043] In addition, esters are preferred as derivatives of oxo fatty acids. Examples of esters of oxo fatty acids of the present invention include, but are not limited to, methyl esters, ethyl esters, propyl esters, butyl esters, pentyl esters, isopentyl esters, octyl esters, etc. In addition, examples of salts of oxo fatty acids include ammonium salts such as ammonium salts, alkyl ammonium salts such as tetramethylammonium salts, alkaline earth metal salts such as calcium salts and magnesium salts, alkali metal salts such as sodium salts, lithium salts, potassium salts, and metal salts such as cobalt salts and manganese salts.

[0044] The hydroxylated fatty acid or its derivative or salt thereof of the present invention is represented by the following formula (II) and / or (III): HOOC-(R 3 )-CH(OH)-CH(OH)-CH=CH-CH(OH)-R 4 (II) HOOC-(R 3 )-CH(OH)-CH=CH-CH(OH)-CH(OH)-R 4 (III) (In the formula, R 3 is a linear or branched hydrocarbon group having 4 to 12 carbon atoms, which may contain one or more double bonds and / or OH groups, and when it contains a double bond, the position of the double bond is not limited; R 4 is a linear or branched hydrocarbon group having 2 to 8 carbon atoms, which may contain one or more double bonds and / or OH groups, and when it contains a double bond, the position of the double bond is not limited. A hydroxylated fatty acid having the structural formula: or a derivative or salt thereof can be suitably used.

[0045] In one embodiment of the present invention, R in the hydroxylated fatty acid 3 The hydrocarbon group has 6 to 8 carbon atoms, and R 4In another embodiment, the hydrocarbon group of R in the hydroxylated fatty acid has 4 to 6 carbon atoms. 3 is -(CH2) n -(n is an integer from 4 to 12), 4 is C n H 2n+1 -(n is an integer of 2 to 8). 3 is an alkylene group having 7 carbon atoms (-(CH2)7-), and R 4 is preferably an alkyl group having 5 carbon atoms (CH3CH2CH2CH2CH2-).

[0046] The hydroxylated fatty acids of the present invention specifically include hydroxyoctadecenoic acids, such as, but not limited to, 9,10,13-trihydroxy-11-octadecenoic acid and / or 9,12,13-trihydroxy-10-octadecenoic acid and their isomers.

[0047] In addition, as the derivative of hydroxylated fatty acid, ester is preferable. Examples of ester of hydroxylated fatty acid of the present invention include, but are not limited to, methyl ester, ethyl ester, propyl ester, butyl ester, pentyl ester, isopentyl ester, octyl ester, etc. In addition, examples of salt of hydroxylated fatty acid include ammonium salt such as ammonium salt, alkyl ammonium salt such as tetramethylammonium salt, alkaline earth metal salt such as calcium salt, magnesium salt, alkali metal salt such as sodium salt, lithium salt, potassium salt, metal salt such as cobalt salt, manganese salt, etc.

[0048] For example, the microalgae growth promoter of the present invention may contain at least one compound selected from ketooctadecadienoic acid or a derivative or a salt thereof and hydroxyoctadecadienoic acid or a derivative or a salt thereof. For example, the microalgae growth promoter of the present invention may contain at least one oxo fatty acid or a derivative or a salt thereof selected from 13-oxo-9,11-octadecadienoic acid and / or 9-oxo-10,12-octadecadienoic acid, and at least one hydroxylated fatty acid or a derivative or a salt thereof selected from 9,10,13-trihydroxy-11-octadecadienoic acid and / or 9,12,13-trihydroxy-10-octadecadienoic acid.

[0049] The unsaturated fatty acid of the present invention is not particularly limited, but an unsaturated fatty acid having about 10 to 20 carbon atoms has the effect of promoting the absorption of the oxo fatty acid or the hydroxylated fatty acid by the microalgae. The cell membrane of the microalgae is composed of lipids, and the oxo fatty acid or the hydroxylated fatty acid is more likely to permeate the cell membrane if the cell membrane contains the unsaturated fatty acid having about 10 to 20 carbon atoms. For example, an unsaturated fatty acid having 18 carbon atoms is preferable. In addition, the number of unsaturated bonds in the molecular structure of the unsaturated fatty acid of the present invention is not limited, and the unsaturated fatty acid may be a monounsaturated fatty acid or a polyunsaturated fatty acid. For example, the unsaturated fatty acid includes, but is not limited to, unsaturated fatty acids such as oleic acid, linoleic acid, oleic acid, α-linolenic acid, γ-linolenic acid, and arachidonic acid. In addition, the unsaturated fatty acid may be in the form of either a free fatty acid or a salt thereof (a salt that can be generally used, for example, the salt exemplified above), and one or more of these may be selected. The unsaturated fatty acid of the present invention may be a commercially available product, or may be a product synthesized from a commercially available compound. In addition, the unsaturated fatty acid may be one type of unsaturated fatty acid, or two or more types of unsaturated fatty acids.

[0050] In addition, when isomers exist in the compounds exemplified in this specification, all possible isomers can be used in the present invention, unless otherwise specified.

[0051] As a specific example of the microalgae growth promoter of the present invention, we will explain the case where it contains at least one compound selected from at least one oxo fatty acid or its derivative or salt and at least one hydroxylated fatty acid or its derivative or salt, and at least one unsaturated fatty acid (excluding oxo fatty acid and hydroxylated fatty acid).

[0052] That is, the unsaturated fatty acids that can be used in the present invention are not limited in compatibility with any particular type of oxo fatty acid or its derivative or salt thereof, or hydroxylated fatty acid or its derivative or salt thereof, and a wide range of unsaturated fatty acids can be used together with oxo fatty acid or its derivative or salt thereof, or hydroxylated fatty acid or its derivative or salt thereof in the microalgae growth promoter of the present invention. For example, the microalgae growth promoter of the present invention may contain at least one compound selected from at least one oxo fatty acid selected from 13-oxoODA and 9-oxoODA, or its derivative or salt thereof, and at least one hydroxylated fatty acid selected from 9,10,13-trihydroxy-11-octadecenoic acid and / or 9,12,13-trihydroxy-10-octadecenoic acid, or its derivative or salt thereof, and at least one unsaturated fatty acid selected from oleic acid, linoleic acid, α-linolenic acid, γ-linolenic acid, and arachidonic acid. For example, the microalgae growth promoter of the present invention may contain at least one compound selected from ketooctadecadienoic acid or a derivative or a salt thereof and hydroxyoctadecenoic acid or a derivative or a salt thereof, and at least one unsaturated fatty acid selected from oleic acid, linoleic acid, α-linolenic acid, γ-linolenic acid, and arachidonic acid. For example, the microalgae growth promoter of the present invention may contain 13-oxo-9,11-octadecadienoic acid, or a derivative or a salt thereof, and linoleic acid, or may contain 9,10,13-trihydroxy-11-octadecaenoic acid and / or 9,12,13-trihydroxy-10-octadecenoic acid, or a derivative or a salt thereof, and linoleic acid, or may contain 13-oxo-9,11-octadecadienoic acid and / or 9,10,13-trihydroxy-11-octadecaenoic acid and / or 9,12,13-trihydroxy-10-octadecenoic acid, or a derivative or a salt thereof, and linoleic acid.

[0053] In the present invention, when mixing at least one compound selected from at least one oxo fatty acid or its derivative or salt thereof, at least one hydroxylated fatty acid or its derivative or salt thereof, and at least one unsaturated fatty acid, it is desirable to use a stabilizer (emulsifier) ​​for ensuring that the at least one oxo fatty acid or its derivative or salt thereof, at least one compound selected from at least one hydroxylated fatty acid or its derivative or salt thereof, and at least one unsaturated fatty acid are stably present as an emulsion in water.

[0054] As the stabilizer (emulsifier), at least one selected from potassium carbonate and dipotassium hydrogen phosphate can be used.

[0055] In the microalgae growth promoter of the present invention, when unsaturated fatty acids (excluding oxo fatty acids and hydroxylated fatty acids) are contained, it is preferable that the ratio of at least one compound selected from oxo fatty acids, or derivatives or salts thereof, and hydroxylated fatty acids, or derivatives or salts thereof, to the unsaturated fatty acids is about 90% or less by weight. If the ratio of at least one compound selected from oxo fatty acids, or derivatives or salts thereof, and hydroxylated fatty acids, or derivatives or salts thereof, to the unsaturated fatty acids is more than 90%, the content of unsaturated fatty acids in the microalgae growth promoter is low, and it is considered that the absorption-promoting effect of oxo fatty acids and hydroxylated fatty acids in microalgae cannot be sufficiently expected.

[0056] In addition, the ratio of at least one compound selected from oxo fatty acids, or derivatives or salts thereof, and hydroxylated fatty acids, or derivatives or salts thereof, to the unsaturated fatty acids in the microalgae growth promoter is preferably about 10% or more by weight. If the ratio of at least one compound selected from oxo fatty acids, or derivatives or salts thereof, and hydroxylated fatty acids, or derivatives or salts thereof, to the unsaturated fatty acids is less than 10%, the amount of active ingredient for the growth promotion effect in the microalgae growth promoter is small, and the growth promotion effect of microalgae may be insufficient.

[0057] The microalgal growth promoter of the present invention may be in any dosage form, such as a liquid, powder, granule, or tablet. For example, the agent may be in a liquid form (i.e., a liquid agent) with an emphasis on ease of administration to microalgae, or may be in a solid form (i.e., a powder, granule, or tablet) with an emphasis on ease of transportation and storage. The microalgal growth promoter of the present invention may also be a dried product that has been made into a powder form using a conventional drying method. Preferably, the drying may be performed by, for example, a freeze-drying method. Preferably, the microalgal growth promoter of the present invention may be a powdered product of a freeze-dried product. The microalgal growth promoter of the present invention may also be a pulverized or crushed product of a freeze-dried product.

[0058] The microalgae growth promoter of the present invention may contain additives or carriers such as excipients, binders, disintegrants, etc., suitable for application to microalgae, as necessary.

[0059] The microalgae growth promoter of the present invention can be used as a culture medium for microalgae. Therefore, the present invention also relates to a method for culturing microalgae, characterized in that microalgae are cultured using the microalgae growth promoter of the present invention. When the microalgae growth promoter of the present invention is used as a culture medium, the culture medium may be prepared to have a composition suitable for culturing the type of microalgae by adding various additives in appropriate amounts to a culture medium containing at least one compound selected from at least one oxo fatty acid or a derivative or a salt thereof and at least one hydroxylated fatty acid or a derivative or a salt thereof, and at least one unsaturated fatty acid (excluding oxo fatty acid and hydroxylated fatty acid) added as necessary. Examples of the additives include, but are not limited to, sugars, organic acids, inorganic acids, organic bases, inorganic bases, vitamins, amino acids, peptides, proteins, and various ions (including natural seawater, artificial seawater, etc.).

[0060] The medium can be used as a medium in a normal culture process according to the type of microalgae. As in normal culture, even in culture using the microalgae growth promoter of the present invention as a medium, the culture conditions, such as the amount of light (light irradiation intensity), temperature, and the supply of CO2 and nutrients, can be changed according to the type of microalgae to be cultured. For example, the optimal light irradiation intensity may vary depending on the type of microalgae, but light may be irradiated at an intensity suitable for the microalgae to be cultured. Although a certain condition of carbon dioxide may be preferable, conditions without carbon dioxide may be acceptable because the microalgae can grow using sugars or organic acids depending on the type of microalgae. The culture temperature may also be set at a condition suitable for the microalgae to be cultured. In addition, the culture solution containing the microalgae being cultured may be stirred or circulated at an appropriate intensity as necessary. The culture time is not particularly limited, but may be, for example, 1 to 30 days.

[0061] Furthermore, the pH of the medium can be appropriately adjusted by adding an appropriate acid or base, if necessary. The suitable pH of the medium depends on the type of microalgae to be cultured, and may be adjusted to, for example, pH 6 to pH 7.

[0062] Sugars that may be added to the medium include, but are not limited to, one or more sugars selected from glucose, galactose, fructose, maltose, sucrose, lactose, oligosaccharides, and sugar alcohols such as glycerol.

[0063] The medium may be provided in a culture tank of a culture device. The culture tank may be equipped with one or more devices selected from a stirring device, a vibration device, a temperature control device, a pH adjustment device, a turbidity measurement device, a light control device, a device for measuring the concentration of a specific gas such as O2 or CO2, and a pressure measurement device. The microalgae may be cultured by any suitable liquid culture method such as a batch culture method, a semi-batch culture method (fed-batch culture method), or a continuous culture method (perfusion culture method).

[0064] The microalgae for which the microalgae growth promoter of the present invention can be used are not particularly limited, but since valuable materials can be extracted from the cultured microalgae, microalgae capable of producing sugars, proteins, oils, or compounds, and / or microalgae that themselves have food or cosmetic uses are preferred, and it is considered to be beneficial to apply the agent to microalgae that accumulate oils and fats as storage materials. The agent can efficiently grow microalgae, and the yield of valuable materials can be increased. Examples of such microalgae include Euglena algae, green algae belonging to the Trebouxiophyceae class, and algae belonging to the Cyanobacteria phylum, and the agent for the microalgae growth promoter of the present invention can be well applied to these microalgae to efficiently grow them. For example, the agent for the microalgae growth promoter of the present invention can be used for at least one or more types selected from algae of the Euglena class (such as Euglena), algae of the Chlorella genus (such as Chlorella), or cyanobacteria of the Oscillaria genus (such as Spirulina), but is not limited thereto. The microalgae to be cultured using the microalgae growth promoter of the present invention is not limited to a specific type of microalgae, but may be phytoplankton, which is a group of many types of microalgae. In addition, genetically modified cyanobacteria or microalgae may also be used as the microalgae.

[0065] Valuable materials can be obtained by extraction and purification from the cultured microalgae. Examples of such materials include raw materials and final products of pharmaceuticals, cosmetics, health foods, etc., oils such as hydrocarbon compounds and triglycerides, alcohol compounds, energy alternatives, enzymes, proteins, nucleic acids, sugars, lipid compounds, carotenoids, etc., and it is believed that the yield of these valuable materials from the cultured microalgae can be increased by using the microalgae growth promoter of the present invention. Therefore, the present invention also relates to a method for producing valuable materials, characterized by utilizing products produced by microalgae cultured using the microalgae growth promoter of the present invention. In addition, as a method for extracting valuable materials from microalgae, purification, extraction, fractionation methods, etc. that are generally used in this technical field can be appropriately used.

[0066] In one embodiment of the present invention, the microalgae growth promoter of the present invention contains at least one ion selected from potassium ions, carbonate ions, phosphate ions, calcium ions, and sodium ions, because these ions contribute to promoting the growth of microalgae.

[0067] When the microalgae growth promoter of the present invention contains these ions, the concentration of each ion is desirably 10 mg / L or more for potassium ions, 5 mg / L or more for carbonate ions, 5 mg / L or more for phosphate ions, 5 mg / L or more for calcium ions, and mg / L or more for sodium ions.

[0068] These ions may be derived from the stabilizer (emulsifier) ​​described above, or may be derived from salts of oxo fatty acids or hydroxylated fatty acids. Furthermore, these ions may be added as additional additives to the microalgae growth promoter of the present invention. EXAMPLES

[0069] The present invention will be described based on examples, but the present invention is not limited to only the examples.

[0070] [Example 1] As the oxo fatty acid or a derivative or salt thereof, 13-oxo-9,11-octadecadienoic acid (13-oxoODA) ((9Z,11E)-13-oxo-9,11-octadecadienoic acid, manufactured by Cayman Chemical Co.), which is a ketooctadecadienoic acid, was used. In addition, as the hydroxylated fatty acid or its derivative or salt thereof, a mixture of hydroxyoctadecaenoic acid, 9,10,13-trihydroxy-11-octadecenoic acid (Larodan Fine Chemicals, 9(S),10(S),13(S)-trihydroxy-11(E)-octadecenoic acid (English: 9(S),10(S),13(S)-trihydroxy-11(E)-octadecenoic acid)) and 9,12,13-trihydroxy-10-octadecenoic acid (Larodan Fine Chemicals, 9(S),12(S),13(S)-trihydroxy-10(E)-octadecenoic acid (English: 9(S),12(S),13(S)-trihydroxy-10(E)-octadecenoic acid)) in a ratio of 2:1 was used. Linoleic acid (primary linoleic acid manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was used as the unsaturated fatty acid. 1 g of linoleic acid was mixed with 0.1 g of 13-oxoODA, 0.02 g of 9,10,13-trihydroxy-11-octadecanoic acid, 0.01 g of 9,12,13-trihydroxy-10-octadecanoic acid, and 0.5 g of dipotassium hydrogen phosphate. This mixture was dispersed in water to prepare 2 L of an aqueous solution (aqueous dispersion) as a growth promoter solution.

[0071] 5 mL of Euglena culture solution (Fujimedaka) was diluted with water to 250 mL, and 50 mL of the solution was dispensed into a clear 100 mL glass bottle, and 1.0 mL of the above growth promoter solution was added to prepare the main culture solution. 1.0 mL of water was added instead of the growth promoter solution to prepare a comparative culture solution. The main culture solution and the comparative culture solution were left under a fluorescent light that was constantly turned on in a room adjusted to 25°C, and were mixed by inversion once a day. The absorbance of each culture solution at a wavelength of 660 nm was measured using a spectrophotometer (BioSpec-mini: Shimadzu Corporation, cell length 1 cm) to evaluate the growth rate of the microalgae.

[0072] On the fourth day of cultivation, the turbidity of the main culture solution was 0.0421, and the turbidity of the comparative culture solution was 0.0296. The microalgae growth promoter of the present invention promoted cell proliferation by about 1.4 times.

[0073] [Comparative Example 1] Solution A was prepared by dispersing 1 g of linoleic acid in 2 L of water, solution B was prepared by dispersing 1 g of oleic acid (primary oleic acid manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) in 2 L of water, and solution C was prepared by dispersing 0.5 g of dipotassium hydrogen phosphate in 2 L of water. 1.0 mL of each of these solutions was added to three 100 mL glass bottles containing 50 mL of Euglena culture dilution solution prepared in the same manner as in Example 1, and the turbidity was measured after culturing under the conditions of Example 1.

[0074] On the fourth day of cultivation, the turbidity of the culture medium with added solution A was 0.0257 (0.9 compared to the comparative culture medium), the turbidity of the culture medium with added solution B was 0.0301 (1.0 compared to the comparative culture medium), and the turbidity of the culture medium with added solution C was 0.0291 (1.0 compared to the comparative culture medium). The turbidity of each culture medium was equivalent to that of the comparative culture medium in Example 1, and no growth-promoting effect was observed with only linoleic acid, oleic acid, or dipotassium hydrogen phosphate.

[0075] [Example 2] A growth promoter solution was prepared in the same manner as in Example 1. 0.5 mL of Chlorella culture solution (manufactured by Medaka Gakuen) was diluted with water to 500 mL, and 50 mL of the solution was dispensed into a transparent 100 mL glass bottle, to which 0.5 mL of the growth promoter solution was added to prepare a main culture solution. A comparative culture solution was prepared by adding 0.5 mL of water instead of the growth promoter solution. The main culture solution and the comparative culture solution were left to stand under a fluorescent light that was constantly turned on in a room adjusted to a room temperature of 25°C, and were mixed by inversion once a day. The turbidity of each culture solution was measured with a spectrophotometer, and the growth rate of the microalgae was evaluated.

[0076] On the fourth day of cultivation, the turbidity of the main culture solution was 0.4559, and the turbidity of the comparative culture solution was 0.4061. The microalgae growth promoter of the present invention promoted cell proliferation by about 1.1 times.

[0077] [Comparative Example 2] Solutions A, B, and C were prepared in the same manner as in Comparative Example 1. 0.5 mL of each solution was added to three 100 mL glass bottles containing 50 mL of the Chlorella culture dilution solution prepared in the same manner as in Example 2, and after culturing under the conditions of Example 2, the turbidity was measured.

[0078] On the fourth day of cultivation, the turbidity of the culture medium to which solution A was added was 0.4082 (1.0 compared to the comparative culture medium), the turbidity of the culture medium to which solution B was added was 0.4141 (1.0 compared to the comparative culture medium), and the turbidity of the culture medium to which solution C was added was 0.4099 (1.0 compared to the comparative culture medium). The turbidity of each culture medium was equivalent to that of the comparative culture medium in Example 2, and no growth-promoting effect was observed with only linoleic acid, oleic acid, or dipotassium hydrogen phosphate.

[0079] [Example 3] A growth promoter solution was prepared in the same manner as in Example 1. 10 mL of Spirulina culture solution (manufactured by Fujimedaka) was diluted with water to 250 mL, and 50 mL of the solution was dispensed into a transparent 100 mL glass bottle, to which 0.05 mL of the growth promoter solution was added to prepare a main culture solution. A comparative culture solution was prepared by adding 0.05 mL of water instead of the growth promoter solution. The main culture solution and the comparative culture solution were left under a fluorescent light that was constantly turned on in a room adjusted to a room temperature of 25°C, and were mixed by inversion once a day. The turbidity of each culture solution was measured with a spectrophotometer, and the growth rate of the microalgae was evaluated.

[0080] On the fourth day of cultivation, the turbidity of the main culture solution was 0.5234, and the turbidity of the comparative culture solution was 0.4434. The microalgae growth promoter of the present invention promoted cell proliferation by about 1.2 times.

[0081] [Comparative Example 3] Solutions A, B, and C were prepared in the same manner as in Comparative Example 1. 0.05 mL of each of these solutions was added to three 100 mL glass bottles containing 50 mL of Spirulina culture dilution solution prepared in the same manner as in Example 3, and after cultivation under the conditions of Example 2, the turbidity was measured.

[0082] On the fourth day of cultivation, the turbidity of the culture medium to which solution A was added was 0.4265 (1.0 compared to the comparative culture medium), the turbidity of the culture medium to which solution B was added was 0.4345 (1.0 compared to the comparative culture medium), and the turbidity of the culture medium to which solution C was added was 0.4539 (1.0 compared to the comparative culture medium). The turbidity of each culture medium was equivalent to that of the comparative culture medium in Example 3, and no growth-promoting effect was observed with only linoleic acid, oleic acid, or dipotassium hydrogen phosphate.

[0083] From the above results, it can be seen that the microalgae growth promoter of the present invention is a growth promoter with a high growth-promoting effect that can efficiently grow microalgae.

Claims

1. A growth promoter for microalgae, comprising at least one compound selected from (1) an oxo fatty acid or a derivative or a salt thereof, or (2) a hydroxylated fatty acid or a derivative or a salt thereof.

2. The microalgae growth promoter according to claim 1 , further comprising an unsaturated fatty acid (excluding the oxo fatty acid and the hydroxylated fatty acid).

3. The microalgae growth promoter according to claim 2, wherein the unsaturated fatty acid is an unsaturated fatty acid having 10 to 20 carbon atoms.

4. The microalgae growth promoter according to claim 2 or 3, wherein the unsaturated fatty acid is an unsaturated fatty acid selected from the group consisting of monovalent or polyvalent unsaturated fatty acids consisting of oleic acid, linoleic acid, α-linolenic acid, γ-linolenic acid, and arachidonic acid.

5. The microalgae growth promoter according to any one of claims 2 to 4, wherein the unsaturated fatty acid is linoleic acid.

6. The microalgae growth promoter according to any one of claims 1 to 5, wherein the oxo fatty acid or a derivative or a salt thereof has the following formula: P.S. 1 )-CH=CH-C(=O)-R 2 (I) (In the formula, R 1 : a linear or branched, saturated or unsaturated hydrocarbon group containing 6 to 12 carbon atoms, R 2 : an alkyl group having 2 to 8 carbon atoms, which may contain one or more branches and / or double bonds) or a derivative or a salt thereof.

7. The oxo fatty acid is R 1 The hydrocarbon group has 8 to 10 carbon atoms, and R 2 The microalgae growth promoter according to any one of claims 1 to 6, wherein the alkyl group has 4 to 6 carbon atoms.

8. The growth promoter for microalgae according to any one of claims 1 to 7, wherein the oxo fatty acid is R 1 is an oxo fatty acid containing a double bond which forms a conjugated double bond with the double bond between the α and β carbons of the carbonyl group in formula (I).

9. The growth promoter for microalgae according to any one of claims 1 to 8, wherein the oxo fatty acid is R 1 is a linear or branched hydrocarbon group having 9 carbon atoms; R 2 is an oxo fatty acid, which is an alkyl group having 5 carbon atoms.

10. The microalgae growth promoter according to any one of claims 1 to 9, wherein the oxo fatty acid is ketooctadecadienoic acid.

11. The microalgae growth promoter according to any one of claims 1 to 10, wherein the oxo fatty acid is 13-oxo-9,11-octadecadienoic acid.

12. The growth promoter for microalgae according to any one of claims 1 to 11, wherein the hydroxylated fatty acid or a derivative or a salt thereof is represented by the following formula (II) and / or (III): P.S. 3 )-CH(OH)-CH(OH)-CH=CH-CH(OH)-R 4 (II) P.S. 3 )-CH(OH)-CH=CH-CH(OH)-CH(OH)-R 4 (III) (In the formula, R 3 is a linear or branched hydrocarbon group having 4 to 12 carbon atoms, which may contain one or more double bonds and / or OH groups, and when it contains a double bond, the position of the double bond is not limited; R 4 is a linear or branched hydrocarbon group having 2 to 8 carbon atoms, which may contain one or more double bonds and / or OH groups, and when it contains a double bond, the position of the double bond is not limited. or a derivative or a salt thereof.

13. The microalgae growth promoter according to claim 12, wherein the hydroxylated fatty acid is R 3 The hydrocarbon group has 6 to 8 carbon atoms, R 4 The hydrocarbon group has 4 to 6 carbon atoms.

14. The growth promoter for microalgae according to claim 12 or 13, wherein the hydroxylated fatty acid is R 3 But -(CH 2 ) n -(n is an integer from 4 to 12), R 4 But, C n H 2n+1 -(n is an integer from 2 to 8).

15. The growth promoter for microalgae according to any one of claims 12 to 14, wherein the hydroxylated fatty acid is R 3 is an alkylene group having 7 carbon atoms (-(CH 2 ) 7 -) and R 4 is an alkyl group having 5 carbon atoms (CH 3 CH 2 CH 2 CH 2 CH 2 -).

16. The microalgae growth promoter according to any one of claims 1 to 15, wherein the hydroxylated fatty acid is hydroxyoctadecaenoic acid.

17. The microalgae growth promoter according to any one of claims 1 to 16, wherein the hydroxylated fatty acid is 9,10,13-trihydroxy-11-octadecaenoic acid.

18. The microalgae growth promoter according to any one of claims 1 to 17, wherein the hydroxylated fatty acid is 9,12,13-trihydroxy-10-octadecaenoic acid.

19. The ratio of the at least one compound selected from the oxo fatty acid or its derivative or its salt and the hydroxylated fatty acid or its derivative or its salt to the unsaturated fatty acid is 10% to 90% by weight. The microalgae growth promoter according to any one of claims 1 to 18.

20. The growth promoter for microalgae according to any one of claims 1 to 19, which is used as a culture medium for microalgae.

21. The microalgae growth promoter according to any one of claims 1 to 20, wherein the microalgae growth promoter is used for at least one selected from Euglena, Chlorella, and Spirulina.

22. The microalgae growth promoter according to any one of claims 1 to 21, further comprising at least one selected from potassium ions, carbonate ions, phosphate ions, calcium ions, and sodium ions.

Images