Method for decolorizing blue-green algae, method for producing decolorized blue-green algae, method for producing blue-green algae-derived polysaccharide, cosmetic, moisturizer, Anti-inflammatory agent, barrier agent, fiber treatment agent, food, and pharmaceutical

Abstract

To provide a method for highly efficiently and simply decoloring blue-green algae.SOLUTION: The method for decoloring the blue-green algae comprises irradiating the blue-green algae with light of ≥ 80 μ molm - 2 * sec - 1 in a liquid at a temperature of ≤ pH5, culturing the blue-green algae, and decoloring the blue-green algae in the liquid at a temperature of ≤ pH5. The method for producing the decolorized blue-green algae includes a decolorization step of irradiating the blue-green algae obtained by the culture step with light of 80 μ molm-2. sec-1, the method for producing the polysaccharide derived from the blue-green algae includes a step of extracting the polysaccharide from the decolorized blue-green algae obtained by the decolorization method or the production method, and the cosmetic contains the polysaccharide derived from the blue-green algae obtained by the production method.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention mainly relates to a method for decolorizing cyanobacteria, and more specifically to a method for decolorizing cyanobacteria, a method for producing decolorized cyanobacteria, a method for producing cyanobacteria-derived polysaccharides, cosmetics, moisturizing agents, anti-inflammatory agents, barrier agents, fiber treatment agents, foods, and pharmaceuticals. [Background technology]

[0002] In recent years, attempts to search for active ingredients from various plants, animals, algae, fungi, etc. have been widely conducted. As a result, various useful substances have been discovered and are being used in a wide range of fields, including pharmaceuticals, foods, and cosmetics. In recent years, a high molecular weight sulfated polysaccharide with a molecular weight exceeding 10 million has been discovered in the blue-green algae (cyanobacteria) Aphanothece sacrum (scientific name: Aphanothece sacrum), and its high moisturizing power is expected to be utilized for beauty effects, burn treatment, etc. Aphanothece sacrum is a freshwater blue-green algae endemic to Japan, and is a rare species that grows in clear spring water in specific areas of the Kyushu region in particular. Many cells are enclosed in an agar matrix, forming amorphous colonies that grow by floating or sinking in the water (see Patent Document 1, etc.).

[0003] Algae generally have distinctive colors such as green, blue-green, red, and brown, and many cyanobacteria have a blue-green (indigo) color due to the presence of green chlorophyll and blue phycocyanin. Aphanothece sacrum has green chlorophyll a, blue phycocyanin, and red phycoerythrin, giving it a green to brown color. The color of algae can affect the color of the final products, such as pharmaceuticals, foods, and cosmetics, and this can lead to a decrease in consumer interest due to the unique color, uneven quality due to the fact that it is a naturally derived material, and a decrease in stability over time due to the fading of pigment proteins over time. Therefore, decolorization is an important process in the industrial use of algae.

[0004] Among the pigments contained in algae, water-soluble pigments such as phycocyanin and phycoerythrin are easily removed because they are released from the algae when the cell membrane is destroyed during cell death. On the other hand, water-insoluble chlorophyll tends to remain in the algae, and extracted sulfated polysaccharides from Aphanothece sacrum will retain their green color due to chlorophyll if not subjected to a decolorization process. Patent Document 2 discloses a method for decolorizing algae for food and beverage use, which includes a decolorization culture step in which the algae are cultured in a specific medium under specific culture conditions, and a decolorization step in which the algae are decolorized using an organic solvent. The method is said to produce algae that are less green or have a lighter color. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 4066443 [Patent Document 2] Patent Publication No. 2017-223313 Summary of the Invention [Problem to be solved by the invention]

[0006] As described above, from the viewpoint of utilizing cyanobacteria and components derived from cyanobacteria, a simple method for decolorizing cyanobacteria and cyanobacteria with reduced color are desired. However, a technology for efficiently decolorizing cyanobacteria has not yet been established. The method described in Patent Document 2 uses an organic solvent in the decolorization step, which raises safety concerns due to residual solvent and environmental concerns due to waste solvent. In addition, the method requires a special culture medium, which raises concerns about cost and effort. The present invention has been made in view of the above problems, and has as its object to decolorize blue-green algae with high efficiency and ease. [Means for solving the problem]

[0007] The present inventors have conducted extensive research to solve the above problems, and as a result have found that blue-green algae can be decolorized simply by irradiating them with light under acidic conditions, thereby completing the present invention. That is, the present invention includes the following aspects. (1) In a liquid with a pH of 5 or less, it is 80 μmol m -2 ·sec -1 A method for decolorizing blue-green algae, characterized by irradiating the blue-green algae with the above-mentioned light. (2) a culturing step of culturing blue-green algae; and In a liquid with a pH of 5 or less, 80 μmol m -2 ·sec -1 a bleaching step of irradiating the dye with light; A method for producing decolorized blue-green algae, comprising: (3) A method for producing polysaccharides derived from cyanobacteria, comprising a step of extracting polysaccharides from cyanobacteria decolorized by the decolorization method of (1) or from cyanobacteria obtained by the production method of (2). (4) The method for producing polysaccharides derived from cyanobacteria according to (3), wherein the cyanobacteria is Aphanothece saccharum. (5) A cosmetic product containing the cyanobacterial polysaccharide obtained by the production method of (4) above. (6) The cosmetic according to claim 5, which is for skin care, makeup, or hair care. (7) A moisturizing agent containing the cyanobacterium-derived polysaccharide obtained by the production method of (4) above. (8) An anti-inflammatory agent containing the cyanobacterial polysaccharide obtained by the production method of (4) above. (9) A barrier agent containing a cyanobacterial polysaccharide obtained by the production method of (4) above. (10) A fiber treatment agent containing the cyanobacterium-derived polysaccharide obtained by the production method of (4) above. (11) A food product containing the cyanobacterial polysaccharide obtained by the production method of (4) above. (12) A pharmaceutical product containing the cyanobacterial polysaccharide obtained by the production method of (4) above. [Effects of the Invention]

[0008] According to the present invention, it is possible to decolorize cyanobacteria simply and easily. The method of the present invention does not require a decolorizing agent, an organic solvent, a special culture solution, or the like, and therefore reduces the environmental impact while saving costs and labor. DETAILED DESCRIPTION OF THE INVENTION

[0009] The present invention will be described in further detail below, but the present invention is not limited to the following embodiments. In this specification, unless otherwise specified, "parts", "%" and "ppm" mean "parts by mass", "% by mass" and "ppm by mass". In this specification, unless otherwise specified, "XX or more and YY or less" or "XX to YY" means a range of values ​​including the lower and upper limit values, which are the endpoints. When a range of values ​​is described in stages, the upper and lower limit values ​​of each range can be combined in any way.

[0010] <Method for decolorizing blue-green algae> In the present invention, cyanobacteria are prokaryotic algae capable of photosynthesis, and are also known as cyanobacteria (blue-green bacteria). Examples of cyanobacteria include the genera Aphanothece, Spirulina, Arthrospira, Aphanizomenon, Fisherella, Anabaena, Nostoc, Synechocystis, Synechococcus, Tolypothrix, Mastigoclaus, and Pleurocapsa. As the cyanobacteria targeted by the present invention, Aphanothece sacrum, Nostoc commune, and Nostoc verrucosum are preferred, with Aphanothece sacrum being particularly preferred. The cyanobacteria used in the present invention may be natural products collected from those growing naturally in the wild, or may be artificially cultured products. In the case of cultured cyanobacteria, the cyanobacteria strain may be a wild-type strain similar to that found in nature, or may be a mutant strain that has been bred, genetically modified, acclimatized, or the like.

[0011] The cyanobacteria to be decolorized may be natural or cultured cyanobacteria themselves, or may have been pretreated by solid-liquid separation, drying, freezing, freeze-thawing, or water-soluble pigment removal. Water-soluble pigments can be removed, for example, by freezing and thawing the algae and then washing them with water. During the decolorization procedure, the cyanobacteria are placed in a liquid with a pH of 5 or less and exposed to light. The container for storing the cyanobacteria and liquid is not particularly limited, but is preferably a container similar to the culture tank described below, as this facilitates uniform irradiation of light from outside. Furthermore, from the viewpoint of uniformly irradiating the cyanobacteria inside with light, the container may be equipped with an aeration system for the purpose of agitation and / or stirring blades (stirring impellers).

[0012] The pH of the liquid is 5 or less, preferably 1.5 to 5.0, more preferably 2.0 to 4.0, and particularly preferably 2.5 to 3.5.

[0013] The liquid is not particularly limited as long as it has the above pH, and examples include water (distilled water, Milli-Q water, tap water, natural spring water) with the pH adjusted by adding an acid, or a medium in which a culture product has been cultured with the pH adjusted by adding an acid, etc. When acid is added to the culture solution in the culture tank used for culture to adjust the pH to the above range and light is irradiated from a light source in the same way as during culture, the process from culture to decolorization can be carried out in one go without the need for special equipment, which offers significant cost benefits.

[0014] The acid is not particularly limited and examples thereof include alginic acid, citric acid, malic acid, ascorbic acid, glucuronic acid, aspartic acid, glutamic acid, adipic acid, gluconic acid, tartaric acid, succinic acid, lactic acid, acetic acid, butyric acid, maleic acid, fumaric acid, hydrochloric acid, ethylenediaminetetraacetic acid (EDTA), sulfuric acid, carbonic acid, nitric acid, etc. An appropriate acid may be selected from these depending on the intended use of the cyanobacteria, and for example, for cosmetics, alginic acid, lactic acid, citric acid, hydrochloric acid, EDTA, acetic acid, sulfuric acid, carbonic acid, nitric acid, etc. are preferred, with citric acid being particularly preferred. The amount of acid added is not limited as long as it falls within the above pH range, but since it is preferable to maintain the pH at 5 or below for the time required for decolorization, it is preferable to appropriately measure and monitor the pH in the liquid and add acid as necessary to prevent the pH from rising. In particular, it is preferable to prevent the pH from rising due to basic components released from the algae cells after their death.

[0015] The light intensity used for bleaching was 80 μmol m -2 ·sec -1 or more, and 80 to 1000 μmol m -2 ·sec -1 is preferred, and 200 to 1000 μmol m -2 ·sec -1 More preferably, 300 to 1000 μmol m -2 ·sec -1 is more preferably 500 to 1000 μmol m -2 ·sec -1 The light source may be natural light or artificial light, and known light sources such as incandescent lamps, fluorescent lamps, arc lamps, and light-emitting diodes can be used as the light source for artificial light. The period of light irradiation is not particularly limited as long as it is a period that achieves good decolorization, but is preferably 0.5 to 200 hours, more preferably 2 to 120 hours, even more preferably 3 to 90 hours, and particularly preferably 6 to 42 hours.

[0016] The decolorization method of the present invention is characterized by irradiating the algae with light at a specific photon flux density or higher under acidic conditions of pH 5 or lower, thereby decomposing chlorophyll such as chlorophyll a in the algae and achieving decolorization. Although the mechanism of decolorization is unclear, it is thought that in a chlorophyll structure in which Mg is coordinated to the center of the tetrapyrrole ring, Mg is ionized under acidic conditions and removed from the tetrapyrrole ring, making the tetrapyrrole ring vulnerable and allowing it to be decomposed by light within a short period of time (1 to 100 hours, more specifically, 12 to 72 hours). Chlorophyll decomposition is known to occur depending on the physiological state within the cell and environmental factors, but the general half-life has been reported to be 300 hours, so it is clear that the method of the present invention decomposes chlorophyll in an overwhelmingly short period of time. In addition, during the decay of plant leaves or when heated, chlorophyll a decomposes by first removing the magnesium ion to produce the yellowish-brown-green pheophytin a, followed by hydrolysis of the phytyl group of pheophytin a to produce pheophorbide a and phytol. Pheophorbide a is then oxygenated by pheophorbide a oxygenase, converting it to the ring-opened tetrapyrrole derivative RCC, then to the red chlorophyll catabolite (pFCC), and finally back to NCC, resulting in a colorless compound (Ulrich et al., "How the Colorless 'Nonfluorescent' Chlorophyll Catabolites Rust," Chemistry - A European Journal, 17(8), 2011, pp. 2330-2334). In other words, the known decomposition mechanism of chlorophyll involves the removal of magnesium ions, decomposition into yellowish-brown-green pheophytin, and then several steps leading to decomposition of the color. However, in the present invention, partial decomposition of the pigment (transformation from green to transparent) occurs within a few hours, and it is expected that this is a significantly simplified decomposition pathway.

[0017] <Method for producing decolorized blue-green algae> The method for producing decolorized cyanobacteria includes a culture step of culturing cyanobacteria, and a method for cultivating cyanobacteria by adding 80 μmol m 2 of cyanobacteria obtained by the culture step in a liquid having a pH of 5 or less. -2 ·sec -1 and a bleaching step of irradiating the above-mentioned light.

[0018] (Culture process) The culturing step is a step of culturing blue-green algae in a liquid in a culture tank. The culture tank is not particularly limited as long as it is capable of storing a liquid and capable of culturing cyanobacteria inside. Specifically, it may be a culture vessel widely used for relatively small-scale cyanobacterial culture, such as a tube, flask, or bottle, a culture vessel incorporated into a culture system such as a (photo)bioreactor, such as a flat panel or tube, or a culture tank used for large-scale algae culture, such as a tank or outdoor culture pond. When a culture vessel is used as a culture tank, the material is not particularly limited, but from the viewpoint of transmitting natural light and artificial light, a material that combines transparency and strength, such as glass, acrylic, or polycarbonate, is preferable. The culture tank may be an open or closed system, but an open system is preferred from the viewpoint of ease of management and connection to peripheral devices and facilities. The culture tank may be equipped with an aeration device for aeration treatment, stirring blades (stirring impellers) for stirring the culture solution during culture, various light sources for irradiating light, a temperature control device for adjusting the temperature during culture, etc.

[0019] The culture can be carried out, for example, in a culture medium. The culture medium is not particularly limited as long as it can maintain and / or grow the cyanobacteria. Specifically, it may be a natural liquid present in nature, such as freshwater or seawater, or an artificial medium (liquid composition) containing nutrients necessary for maintenance and / or growth.

[0020] Known artificial media can be used. Among these, preferred are artificial media containing one or more salts selected from carbonate, bicarbonate, phosphate, and citrate. In addition to these salts, water and other minerals may be added to the artificial media. Known media such as those described in patent literature (Japanese Patent No. 6590144) and non-patent literature (J. Gen Appl Microbiol., 65, 39-46, 2019 Mar.) to which the above salts have been added may also be used. Furthermore, when natural liquids such as freshwater are used for cultivation, the above salts may be added to the natural liquid. These salts can further improve the cultivation efficiency of cyanobacteria, and since they are particularly suitable as carbon sources for photosynthesis by cyanobacteria, it is particularly preferable to add one or more salts selected from carbonates and bicarbonates, and specifically, it is most preferable to use sodium bicarbonate or calcium bicarbonate. For example, when the cyanobacteria are freshwater cyanobacteria such as Aphanothece sacrum, Aphanothece sacrum and the like efficiently utilize specific ions such as bicarbonate ions for photosynthesis, making it possible to rapidly and continuously cultivate large quantities of the target cyanobacteria while suppressing the growth of other algae.

[0021] The amount of one or more salts selected from carbonates, bicarbonates, phosphates, and citrates added to the liquid medium is preferably 1 mass ppm or more and 500 mass ppm or less, and particularly preferably 20 mass ppm or more and 200 mass ppm or less to maintain better growth of the cyanobacteria. Bicarbonates are consumed as a carbon source when the cyanobacteria photosynthesize, but when carbon dioxide is added to the liquid medium by a procedure such as bubbling, they are regenerated as bicarbonate ions, which can be used again as a carbon source for the cyanobacteria, allowing for efficient cultivation.

[0022] The pH of the liquid is not particularly limited, and in the case of natural liquids, pH adjustment may or may not be performed. Furthermore, when using an artificial medium, the pH is preferably adjusted and maintained within a range of pH 10 or less during cultivation, more preferably within a range of pH 7.5 to 10, and most preferably within a range of pH 8 to 9, as this significantly improves cultivation efficiency. Although pH adjustment may be performed throughout the cultivation period, it is preferable to adjust the pH during light irradiation, as this particularly improves cultivation efficiency. The method for adjusting the pH of the liquid medium is not particularly limited, but examples include a step of observing the increase in pH associated with the cultivation of cyanobacteria, and adding carbon dioxide to the liquid medium when the pH rises to around 10 to lower the pH. Details regarding the addition of carbon dioxide will be described later.

[0023] Cultivation can be initiated by inoculating a liquid with an appropriate amount of cyanobacteria. The algae to be inoculated into the medium may be those that have been passaged in a solid medium, those that have been pre-cultured in a liquid medium, or those that have been collected from nature. The amount of algae to be inoculated at the start of cultivation is not particularly limited. 800 The inoculation amount can be set so that the ratio of the number of bacteria to the number of bacteria is about 0.01 to 5, preferably about 0.05 to 3, and more preferably about 0.1 to 1. "OD 800 " means the optical density of the culture medium at a wavelength of 800 nm. OD 800 can be determined by measuring the optical density of the culture medium at a wavelength of 800 nm using a spectrophotometer.

[0024] The culture conditions are not particularly limited as long as they allow the growth of the cyanobacteria to be cultured. The light conditions are not particularly limited, but the light intensity for cyanobacteria that grow autotrophically through photosynthesis is 10 to 2000 μmol m -2 ·sec -1 and 30 to 1500 μmol m -2 ·sec -1 is preferred, and 50 to 1200 μmol m -2 ·sec-1 More preferably, 50 to 1000 μmol m -2 ·sec -1 is more preferable. The cells may be cultured in a bright place using natural light or artificial light; they may be cultured in a dark place and constantly exposed to artificial light; or they may be cultured in a dark place and a light-dark cycle (L / D) may be established using artificial light. Examples of the light-dark cycle include 10L:14D to 14L:10D. For artificial light irradiation, known light sources such as incandescent lamps, fluorescent lamps, arc lamps, and light-emitting diodes can be used.

[0025] The culture temperature is not particularly limited as long as it is a temperature at which the cyanobacteria to be cultured can grow. Examples of the culture temperature include 15 to 50°C. When culturing Aphanothece sacrum, the culture temperature is preferably between 15 and 30°C, more preferably between 20 and 25°C, and even more preferably between 23 and 25°C.

[0026] Although the culture may be performed by static culture, it is preferable to perform the culture by generating a water current in the liquid in order to prevent a shortage of carbon dioxide during photosynthesis and a shortage of oxygen during non-photosynthesis or in heterotrophic cyanobacteria. Here, "generating a water current" refers to bringing the liquid in the culture tank into a motile state by applying some external factor (addition of gas or liquid, or imparting energy) to the liquid. Examples of culture methods that generate a water current include aeration culture (aeration culture), shaking culture, and culture with stirring. The conditions for aeration (aeration), shaking (swirl), or stirring may be such that the dissolved carbon dioxide and dissolved oxygen in the liquid are not depleted and that the cyanobacteria to be cultured can grow.

[0027] In the case of cyanobacteria that grow autotrophically through photosynthesis, the concentration of dissolved carbon dioxide in the liquid may decrease due to the consumption of carbon dioxide under light irradiation conditions, resulting in an increase in pH. In such cases, aeration or aeration is preferably performed during light irradiation to adjust the pH and replenish carbon dioxide. The use of a liquid medium containing a salt such as bicarbonate as described above is particularly preferred, as the addition of carbon dioxide replenishes the consumed bicarbonate ions, improving the photosynthetic efficiency of the cyanobacteria. In addition, an operation may be carried out to maintain a constant pH so as not to increase the pH. Carbon dioxide added for the purpose of adjusting the pH may be ordinary air to which carbon dioxide has been added, or air to which carbon dioxide has been further added, or carbon dioxide alone may be added by aeration treatment as described below. Furthermore, in the case of cyanobacteria that grow heterotrophically by utilizing organic carbon sources or that grow mixotrophically (a combination of autotrophic and heterotrophic growth), the amount of oxygen consumed increases as the number of cyanobacteria increases, which can lead to a decrease in the dissolved oxygen concentration in the liquid. In such cases, it is preferable to perform aeration or ventilation to replenish oxygen.

[0028] The aeration rate should be such that the cyanobacteria can circulate in the liquid without foaming or the like and so that light is evenly irradiated onto the cyanobacteria in the liquid. There are no upper or lower limits for the aeration rate, but in practice it can be set to 12 vvm or less. Examples of lower limits for the aeration rate include 0.5 vvm or more, or 1.0 vvm or more. vvm (volume per volume per minute) is a unit that represents the amount of aeration per unit volume of culture solution per minute. Shaking and stirring can be carried out using a known shaking device, stirring device, or stirring blade. The rotation speed for shaking and stirring is, for example, 100 to 500 rpm, preferably 150 to 400 rpm, and more preferably 200 to 350 rpm.

[0029] The number of revolutions for shaking or stirring and / or the amount of aeration may be changed depending on the concentration of dissolved carbon dioxide or dissolved oxygen in the liquid during the culture period. Therefore, when the dissolved oxygen concentration in the medium decreases by a predetermined amount, the shaking or stirring speed and / or the aeration rate may be increased. For example, when the dissolved oxygen concentration decreases by 10 to 30% (e.g., 20%) relative to the dissolved oxygen concentration in the initial medium, the shaking or stirring speed and / or the aeration rate may be increased. The shaking or stirring speed may be increased, for example, by 30 to 60 rpm (e.g., 50 rpm) as the dissolved oxygen concentration in the medium decreases by a predetermined amount. The aeration rate may be increased, for example, by 0.5 to 1.0 vvm (e.g., 0.7 vvm) as the dissolved oxygen concentration in the medium decreases by a predetermined amount. The dissolved oxygen concentration in the medium can be measured using a dissolved oxygen meter.

[0030] (Decolorization process) The decolorization step is the same as that described in the "Decolorization Method for Cyanobacteria" above. When the decolorization step is performed following the culture step, it is simple and preferable to add an acid or the like to the culture solution containing the cultured cyanobacteria to adjust the pH, as described above, and then irradiate the culture solution with light from the light source used during culture.

[0031] <Method for producing blue-green algae-derived polysaccharides> The cyanobacteria produced by the above-mentioned "method for bleaching cyanobacteria" or "method for producing bleached cyanobacteria" can be used for various purposes after undergoing some kind of treatment, but if the cyanobacteria contain useful components (e.g., polysaccharides), they can be extracted to make them in a form that is easy to use as active ingredients. According to the present invention, the color of the cyanobacteria themselves is bleached in advance, and polysaccharides and other components that could be active ingredients are also bleached, making them easy to use industrially for a variety of purposes.

[0032] When the cyanobacterium is Aphanothece sacrum, polysaccharides extracted from Aphanothece sacrum are sold under the trademark "Sakuran" (registered trademark). Sakuran is derived from Aphanothece sacrum, has an average molecular weight of 2,000,000 or more, and has a repeating structure of sugar chain units in which sugar structures having hexose structures and sugar structures having pentose structures are linked in a linear or branched chain by α-glycosidic bonds or β-glycosidic bonds, and in the sugar chain units, 2.7 or more hydroxyl groups per 100 hydroxyl groups are sulfated, or sulfur accounts for 1.5% by weight or more of the total elements, and the sugar chain units are sugar derivatives that contain lactated sulfated sugars as sugar structures. An example of a method for extracting Aphanothece sacrum-derived polysaccharides from Aphanothece sacrum is described in International Publication WO2008 / 062574. Specific methods for extracting A. saccharin-derived polysaccharides from A. saccharin include drying the decolorized algae as described above, adding 0.1 to 0.5 N sodium hydroxide to the resulting dried A. saccharin algae, stirring at 60 to 80°C for 1 to 6 hours, neutralizing the resulting sugar derivative solution with acid, filtering, concentrating, and drying. In another example, saccharin can be extracted from A. saccharin by heating an aqueous dispersion of A. saccharin in an autoclave at 135°C for 30 minutes. The extracted A. saccharin-derived polysaccharides may be purified by centrifugation, filtration, alcohol washing, or the like.

[0033] <Applications (cosmetics, food, medicines, etc.)> The cyanobacterium-derived polysaccharide (Aphanothece sacrum-derived polysaccharide) obtained as described above can be used in cosmetics, foods, medicines, and the like. Polysaccharides derived from Aphanothece sacrum have been reported to have moisturizing, anti-inflammatory, and barrier effects, and therefore can be used as moisturizing agents, anti-inflammatory agents, and barrier agents in cosmetics and pharmaceuticals. Furthermore, it is known that polysaccharides derived from Aphanothece sacrum are used as a fiber treatment agent to impart moisture absorption, water absorption, quick-drying, moisture-releasing properties, stain resistance, antistatic properties, a good texture, and washing resistance, which do not lose these functionalities even after washing, and therefore are also suitable for use as a fiber treatment agent. When used as a fiber treatment agent, a solution containing polysaccharides derived from Aphanothece sacrum can be applied to the fiber substrate, followed by a drying step to remove liquid components from the applied fiber treatment composition, and then the fiber treatment can be carried out by applying it to the surface of the fiber substrate. [Example]

[0034] The present invention will be described below with reference to examples, but the present invention is not limited to the following examples.

[0035] [Example 1] One liter of sodium bicarbonate-supplemented medium described in Table 1 was placed in a 1-liter glass container, and 20 g of cultured Aphanothece sacrum (FPU1 strain: Ohki, K et al. J Gen Appl Microbiol. 2019 Mar 8;65(1):39-46.) was added in wet weight. The culture was maintained at 23°C in an atmosphere with an aeration rate of 0.5 L / min and a photosynthetic photon flux of 130 μmol m -2 ·sec -1 The plants were cultured under a 14-hour light / 10-hour dark cycle. During the light period, when the pH rose to around pH 9, carbon dioxide was injected to lower the pH to around pH 8, thereby controlling the pH. The culture was then terminated approximately 96 hours after the start of culture. The A. saccharinum was a deep green color at the end of culture.

[0036] [Table 1]

[0037] After the cultivation was completed, 1 L of the liquid described in Table 2 and 10 g (wet weight) of Aphanothece sacrum after the cultivation were placed in a glass container. The pH of the liquid was 5.0. -2 ·sec -1 The treated algae of Example 1 were obtained by decolorization treatment for 24 hours at a light intensity of 1000 kJ / cm. The light source used was a commercially available neutral white fluorescent lamp (Panasonic "Pallook Natural Color FL40SS ENW / 37"). Four of these light sources were installed to ensure that the light was evenly irradiated onto the algae, and the glass container was irradiated from four directions: front, back, left, and right. The lighting equipment, including the light sources, was the same as that used for cultivation.

[0038] [Examples 2 to 9] Treated algal bodies of Examples 2 to 9 were obtained in the same manner as in Example 1, except that the liquid and pH, amount of algal bodies (wet weight), amount of light, and treatment time were as shown in Table 2.

[0039] [Example 10] Cultivation was carried out in the same manner as in Example 1, except that Spirulina (Arthtrospira) platensis was used instead of Aphanothece sacrum, Zarrouk medium was used instead of the sodium bicarbonate-supplemented medium, and the cultivation was terminated when the wet weight reached 10 g / L. The spirulina was deep green at the end of the cultivation. Thereafter, decolorization treatment was carried out in the same manner as in Example 1, and treated algal bodies of Example 10 were obtained.

[0040] [Comparative Examples 1 to 9] Treated algal bodies of Comparative Examples 1 to 9 were obtained in the same manner as in Example 1, except that the liquid and pH, amount of algal bodies (wet weight), amount of light, and treatment time were as shown in Table 3.

[0041] (evaluation) The treated algal cells obtained in each example were visually evaluated based on the following criteria. The results are shown in Tables 2 and 3. A: Heavily bleached and white B: Slightly decolorized and brown C: Almost no bleaching, dark green

[0042] [Table 2]

[0043] [Table 3]

[0044] From the above results, it was confirmed that the algae could be successfully decolorized by performing treatment under low pH conditions with a specific light intensity and for a specific time.

Claims

1. In a liquid with a pH of 5 or less, it has an activity of 80 μmol m against blue-green algae. －２ ・sec －１ A method for decolorizing blue-green algae, characterized by irradiating the blue-green algae with the above-mentioned light.

2. A culturing step of culturing blue-green algae; In a liquid having a pH of 5 or less, the concentration of 80 μmol m －２ ・sec －１ a bleaching step of irradiating the dye with light; A method for producing decolorized blue-green algae, comprising:

3. A method for producing polysaccharides derived from cyanobacteria, comprising a step of extracting polysaccharides from cyanobacteria decolorized by the decolorization method of claim 1 or from cyanobacteria obtained by the production method of claim 2.

4. The method for producing a cyanobacterial polysaccharide according to claim 3, wherein the cyanobacterium is Aphanothece saccharum.

5. A cosmetic product containing the cyanobacterial polysaccharide obtained by the method of claim 4.

6. The cosmetic according to claim 5, which is used for skin care, makeup, or hair care.

7. A moisturizing agent containing the cyanobacterium-derived polysaccharide obtained by the production method according to claim 4.

8. An anti-inflammatory agent comprising the cyanobacterial polysaccharide obtained by the method of claim 4.

9. A barrier agent comprising the cyanobacterial polysaccharide obtained by the production method according to claim 4.

10. A fiber treating agent containing the cyanobacterial polysaccharide obtained by the method of claim 4.

11. A food product containing the cyanobacterial polysaccharide obtained by the method according to claim 4.

12. A pharmaceutical product comprising the cyanobacterial polysaccharide obtained by the method according to claim 4.

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