JPH04122701A - Beta-glucan and its production - Google Patents

Abstract

PURPOSE:To obtain a beta-glucan having high viscosity and improved stability and functional characteristics by specifying its manner of bonding, its molecular weight and its viscosity. CONSTITUTION:Microorganisms belonging to the genus Macrophomopsis are cultured to obtain a beta-glucan having a manner of bonding in which all of the D-glucopyranosyl residues (D-GP residues) in the main chain are bonded through a beta-1,3 bond, there is a branch in the C-6 position of the D-GP residue of the main chain and there is one D-GP residue bonded through a beta-1,6 bond as a side chain for every four D-GP residues bonded through a beta-1,3 bond in the main chain, having a molecular weight (as determined by high-performance liquid chromatography through a molecular sieve column) of about 10000000 Dalton or above, having a relationship of the temperature dependency of the viscosity in which the viscosity is constant in the range of 5-8 deg.C in a concentration of 0.3wt.% or below and is also constant in the range of 20-85 deg.C even in a concentration of above 0.3wt.% and having a viscosity which is stable even when it is autoclaved at 121 deg.C or below under a pressure of 1kg/cm<2> for 20min.

Description

[Detailed description of the invention]

[0001]

[Industrial application field]

The present invention relates to a novel β-glucan with high viscosity and a method for producing the same. [0002]

[Prior Art and Problems to be Solved by the Invention] Polysaccharides are used in a wide variety of fields, including the food industry, cosmetics industry, pharmaceutical industry, paper industry, and chemical industry. [0003] Conventionally, polysaccharides have been mainly supplied from plants, seaweed, etc., but recently polysaccharides from microorganisms that can be stably supplied whenever needed have been developed and supplied. [0004] Regarding polysaccharides produced by microorganisms, those produced by alkaline earth metals, bacteria belonging to the genus Xanthomonas, genus Pseudomonas, etc., and fungi belonging to the genus Plulania, genus Sclerotium, genus Aspergillus, etc. are known. ing. However, surprisingly few neutral polysaccharides are heat-stable, highly viscous at room temperature, have no sticky feel, and are sensually superior. [0005] Furthermore, looking at the structure of polysaccharides, homoglucans having β-1,3 glucoside bonds in the main chain, so-called β-1,3
Glucans are found in fungi such as basidiomycetes, yeasts, and filamentous fungi [000
6] - For example, lentinan from the fruiting bodies of shiitake mushrooms, β-1,3 glucan from basidiomycetes including ganoderan (2) from cultures of Canoderma sp., and scleroglucans produced by Sphlerotium deuteromycetes. and β-1,3 glucans such as Pestalotan produced by the Ascomycete Pestalotia. [0007] “Isolation and cultivation of mold, fixation, and production and application of useful substances” Mold Application Development Research Group (Dobundo) P, 354-369 [0008] However, among these, viscosity that is stable against heat shows,
There was no β-glucan with a molecular weight higher than D-glucopyra in the main chain. Moreover, there were surprisingly few products that did not have a sticky feeling and were sensually superior. [0009] The present invention aims to obtain a novel high-viscosity polysaccharide that is stable and has excellent organoleptic properties. [0010]

[Means to solve the problem]

The present invention provides high viscosity β characterized by having the following properties.
-It is a glucan. [0011] (a) The bonding mode is that all D-glucopyranosyl residues in the main chain are β-1,3 bonds, and there is a bond at the C-6 position of the D-glucopyranosyl residue in the main chain, and β-1,3-bonded D-glucopyranosyl residue 4, which is the main chain.
Each has one β-1,6-linked D-glucopyranosyl residue as a side chain. [0012] (b) The molecular weight is about 10 million Daltons or more as determined by high performance liquid chromatography using a molecular sieve column. [0013] (c) The temperature dependence of viscosity is such that at a concentration of 0.3% by weight or less, the viscosity is constant between 5°C and 85°C, and 0.
．． It has a constant viscosity between 20°C and 85°C even at concentrations exceeding 3% by weight. [0014] (d) The viscosity is stable even when heated at 121° C. in an autoclave at 1 kg/cm 2 (20 minutes). [0015] The present invention also provides macrophomopsis
A method for producing β-glucan, which comprises culturing a microorganism belonging to the genus Omo 5is) and collecting the above-mentioned β-glucan from the culture. and a method for producing β-glucan, which is characterized in that a sugar containing galactose as a backbone is used as a carbon source in culturing a microorganism belonging to the genus Macrophomopsis. Furthermore, it is a method for producing β-glucan in which the sugar containing galactose as a skeleton is lactose. [0016] The microorganism used in the present invention is Macrophomopsis (Mac
For example, the strain named Macrophomopsis KAB55, which was deposited as Fiber Entrustment No. 9366, belongs to the genus Macrophomopsis KAB55. [0017] The KAB55 will be explained below. ■Isolated from soil in Odawara City, Kanagawa Prefecture, where it was collected. [0018] Characteristics of KAB55 on various culture media based on macroscopic and microscopic observations are as described below. 1) Macroscopic Observation The growth form of the filamentous fungus KAB55 strain at 25°C was investigated. [0019] 1. Growth on Tzapek Dox agar medium was relatively fast, and hyphal elongation was observed on the second day of culture. On the 5th day of culture, white fluff-like hyphae were actively proliferating. Hyphae grow densely throughout. Around the 12th day, the colony grows to about 5.5 cm, and the back side of the center of the colony becomes yellowish brown. From around the third week, hyphae began to grow in the slightly peripheral areas rather than the center of the colony. [0020] 2. Growth on potato dextrose agar medium is relatively fast, and the hyphae are white and fluff-like. In the center of the colony, the hyphae are not very proliferative, but in the periphery they are very active, and the hyphae become dense and doughnut-like. Furthermore, the hyphae extend from there, forming a slightly sparse hyphal zone around the donut, and a dense hyphal zone around the tip. The sparse hyphal zone also becomes denser, forming an even larger donut-like colony. The colony reaches 6.5 to 7.5 crn around the 12th day. The underside of the center of the colony turns yellowish brown. After 3 weeks at the mouth, hyphae proliferate to the center of the colony, and the entire colony becomes covered with hyphae. After that, a swell of mycelia began to appear on the periphery of the colony, turning a dark green color. [0021] 3. Compared to malt extract agar medium 1.2, the initial growth of white fluff-like mycelium is slow. However, the colony expands quickly. From around the 5th day, a repeating pattern of sparse and dense hyphal zones is observed from the center of the colony to the periphery. By around day 12, the colony will be 8.5 cm. After three weeks, the mandala pattern fades and becomes completely covered with mycelium. [0022] 4. Growth on corn mill medium is extremely fast, and hyphae grow in a white fluff-like manner similar to potato dextrose agar medium. Suitable for non-conidial formation, both epiphytic and maturation of conidia occur rapidly. Conidiophores are formed slightly embedded in agar. 1%
When cultured with the addition of meat extract, the cells turn purple. [0023] 5. Oatmill agar medium It behaves almost the same as corn mill medium. [0024] 2) Morphology under a microscope Mycelium on an agar medium such as a corn mill is white fluff-like, grows as if it is wrapped in the agar, has branches, and has septa. The conidiospores formed on the agar medium are dark brown, spherical, and have an opening. The aperture is single and round, and the central conidiophore is colorless and branched, with septa visible only at the base, and has a cylindrical shape. All conidiogenic cells are amorphous. Conidia are colorless and spindle-shaped without septa. The tip of the conidium is acute;
The rear end is cut. [0025] 3) Growth pH It can grow in the pH range of pH 3.5 to 9.0, but at pH 2.
It cannot grow below 5. Optimum growth pH is 5.0 to 8.
．． It is 0. [0026] 4) Grows in a temperature range of 10°C to 40°C, but below 5°C or 4
It cannot grow above 5℃. Growth at 35°C to 40°C is
As fast as 28°C. Mainly the formation of white mycelium, and temperatures below 28°C are suitable for the formation and maturation of conidia. The optimal temperature for growth and conidiophore formation is 20℃~3
It is 0°C. The novel polysaccharide of the present invention has the following physical and chemical properties. Molecular weight of [0027]: Pullulan of a certain molecular weight was calibrated by high performance liquid chromatography (hereinafter abbreviated as HPLC) using an Asahipak G5-710 column (exclusion limit molecular weight: 10 million) using 50 mM sodium chloride solution as the mobile phase. When molecular sieving was performed using a wire,
A single peak is observed near the exclusion limit. Therefore, its molecular size is about 10 million Daltons or more, indicating an extremely large molecular size. [0028] (2) Ultraviolet absorption spectrum: No absorption is shown. [0029] (3) Infrared absorption spectrum: As shown in FIG.
Absorption at about 890 cm', which is characteristic of glycosidic bonds, is observed, but absorptions at about 9170 cm, about 844 cm, and about 766 cm, which are characteristic of α-glycosidic bonds, are not observed. Therefore, it was found that the polysaccharide of the present invention has only β-glycosidic bonds. [0030] (4) Solubility in solvents: Soluble in water, soluble in 0.5N sodium hydroxide, 90% formic acid, insoluble in organic solvents such as methanol, acetone, chloroform, and ethyl acetate. [0031] (5) Color reaction A) Phenol-sulfuric acid reaction: + B) Iodine reaction C) Carbazole-sulfuric acid reaction: D) Ninhydrin reaction [0032] (6) Distinction between basic, acidic, and neutral: Book The pH of an aqueous solution of a substance is neutral. [0033] (7) Color of substance: white. [0034] (8) Type of constituent sugar: 2.5N) Hydrolyzed with refluoroacetic acid for 8 hours and then
When analyzed by HPLC using an SK-gel Sugar AXG column (manufactured by Toyo Soda Co., Ltd.), it was found that the polysaccharide of the present invention had only glucose as its main component. [0035] (9) Degradability by enzymes: This polysaccharide is treated with downstream enzymes, each enzyme containing 2.5 Units.
s, pH 5.0, 37°C, 0-24 hr reaction) The hydrolyzable ability was determined by thin layer chromatography (developing solvent: n-
Butanol:acetic acid:ethyl ether:water=9:6
: 3 : 1) and Asahipak G5-71
As a result of observation by 0HPLC, α-amylase, β-
It was not hydrolyzed at all by amylase and glucoamylase, and only laminarinase showed degradable ability in both analytical methods. [0036] (10) Viscosity a) Viscosity: The solution of this polysaccharide becomes a highly viscous neutral solution. 1% when measuring the viscosity with a bismetron rotational viscometer
The viscosity is 1200 to 1700 centipoise in an aqueous solution, which is about twice the viscosity of existing xanthan gum.
At a concentration of 0.3% by weight or less, it has a constant viscosity between 5℃ and 85℃, and even at a concentration exceeding 0.3% by weight, it has a constant viscosity at 20℃
It has a constant viscosity between ~85°C. The measurement results are shown below. [0038] Polymer concentration 0.3% 0.5% 1°0% Temperature (cps) 5°C 240 728 262
010℃ 240 697 1
56020℃ 239 609
115930℃ 240 609
113740℃ 240 60
9 113085℃ 240
609 1130 [0039] Each sample solution was left in a constant temperature bath at a predetermined temperature for about 1 hour, then taken out of the constant temperature bath, and its viscosity was immediately measured. [0040] C) Stability against heating: 1 kg/cm2 at 121°C
The viscosity remains stable even after autoclave heating (20 minutes). That is, when the above autoclave treatment was performed using a 0.3% by weight solution, the viscosity before treatment was 207 CpS and after treatment was 210 cps. [0041] d) Stability against acids and alkalis: Shows relatively stable viscosity in the pH range of 2 to 13. [0042] E) Stability against salts It exhibits a certain viscosity and is stable even in the presence of any salt such as diborate, acetate, sulfate, sodium salt, potassium salt, calcium salt, magnesium salt, etc. [0043] (11) Bonding mode After dissolving the polysaccharide of the present invention in dimethyl sulfoxide, a methyl derivative is obtained by the Hakomori method using a methyl sulfonyl carbanion and methyl iodide. After hydrolyzing this with an acid, the methylated sugar is converted into an aldeitol, When induced into acetate, fixed and quantitatively analyzed using a combination of gas chromatography and mass spectrometry, the product was 2,3°4.6-tetra-0-
Methyl-D-glucose, 2,4.6-tri-O-methy[0044] Furthermore, the polysaccharide of the present invention was oxidized with periodic acid, reduced with sodium borohydride, and then hydrolyzed with acid (Smith
Disassembly). After reducing it again with sodium borohydride in the presence of ammonia, it was identified and quantified as an acetate derivative by gas chromatography, and the following product was observed. Glucose is 3.5 to 4.3 moles per 1.0 mole of glycerol. [0045] From the above results, in the β-glucan of the present invention, all of the D-glucopyranosyl residues in the main chain are β-1,3 bonds, and there is a branch at the C-6 position of the D-glucopyranosyl residue in the main chain. death,
It is a neutral polysaccharide having one β-1,6-linked D-glucopyranosyl residue as a side chain for every four β-1,3-linked D-glucopyranosyl residues in the main chain. [0046] (12) Water evaporation test Pour a certain amount of water into the sample bottles of the 4 groups, paste a second base paper (waxed thin paper used on a mimeograph board) on the mouth of the bottle, and place the top of each group's base paper on top of the bottle. 1% hyaluronic acid solution, 1 hyaluronic acid 0.5% solution, 1 polysaccharide 1% solution and 0.0% polysaccharide solution, respectively.
The amount of water evaporated was determined by applying a certain amount of the 5% solution and measuring the weight of the sample bottle over time. [0047] In addition, paper coated with water was used as a control, and three samples in each group were used for measurement. The results are shown below. [0048] Moisture transpiration test, test water transpiration amount (mg) Coating material Toh 7-7-1-Publication 4th day 1
8th day 112th day 1 Polysaccharide 1% 0.5% Hyaluronic acid Oo 1% 5% Water (measured at 3 points per group, and the average value is shown) [004
9] This polysaccharide contains hyaluronic acid, which has a moisturizing effect. [0050] (13) Safety test The sensitization test of the polysaccharide of the present invention (Maximizat i
On method, sample concentration: induction 1% (twice), challenge 0.5% and 1%), no animals were found to be septum positive in guinea pig 10. In addition, the photosensitivity test (Adjuvant) of the polysaccharide of the present invention
-5tri ip method, sample concentration: induction 1%, induction 0.5%
and 1%), none of the 10 guinea pigs was recognized as septate. [0051] From the above, the polysaccharide of the present invention was a polysaccharide with low sensitization and high safety. [0052] (14) Other characteristic properties The polysaccharide of the present invention is tasteless and odorless. In addition, the polysaccharide of the present invention exhibits a smooth feel when applied, without the slippery feeling that existing xanthan gum has, as shown by the results of the sensory test in the application example described below. [0053] Next, a culture method and a purification method will be described. Examples of the carbon source used for culturing this polysaccharide-producing bacterium include glucose, glycerin, maltose, starch, sucrose, fructose, molasses, and mixtures thereof. [0054] When the above sugars are used, β-glucan and α-glucan are simultaneously accumulated in the culture, but when a sugar containing galactose as a backbone is used as a carbon source, microorganisms belonging to the genus Macrophomopsis Moreover, only β-glucan can be selectively produced and accumulated in the culture, which is more preferable because β-glucan can be recovered and used more easily and at low cost. [0055] Examples of sugars containing galactose as a skeleton include galactose, lactose melibiose, raffinose, and stachyose, but lactose is particularly preferred in terms of yield. [0056] As the nitrogen source, all organic and inorganic nitrogen sources used for culturing microorganisms can be used, such as absorbent cottonseed powder (Pharmamed ia), cornstarch liquor, yeast extract, and dried Examples include yeast, various peptones, oatmeal meat extract casein hydrolyzate, ammonium salts, nitrates, and the like. [0057] Examples of the geothermal additive include inorganic salts such as sodium chloride, magnesium, calcium, and phosphoric acid. [0058] Further, if necessary, a small amount of metal salts such as iron, copper, manganese, etc. may be added to the medium. [0059] Cultivation is carried out in an ordinary aqueous medium containing the above-mentioned culture medium by shaking culture, deep aeration culture, Deep aeration agitation culture and single-rotation drum culture can also be carried out. [00601 Culture conditions are pH 3.5-9. O1 preferably pH 5.0
~8.0, culture temperature is 10~40℃, preferably 20~
Culture is usually carried out at 35°C for 3 to 7 days. The polysaccharide of interest of the present invention can be obtained from the culture thus obtained. [0061] This culture solution is treated with an appropriate method such as filtration or centrifugation to remove the microbial cells. Next, approximately 10 to 35% by weight of an organic precipitant such as a suitable precipitant such as ethanol, methanol, isopropanol, acetone, etc. is added to the obtained filtrate or supernatant to precipitate β-glucan. This precipitate is separated by an appropriate method such as filtration or centrifugation, and then redissolved in water, followed by repeated precipitation with a precipitant, followed by dialysis and freeze-drying.
A purified polysaccharide is obtained. [0062] By this operation, β-glucan can be separated and purified from α-glucan and other components in the culture. When using a sugar containing galactose as a backbone, only β-glucan is accumulated, so α-glucan and β-glucan are
It has a lower viscosity than glucan mixed systems, and filtration or centrifugation of bacterial cells can be completed easily and in a short time. [0063] Since only β-glucan is accumulated in the culture, α
- Although a separation step from glucan is not necessary, highly pure β-glucan can be efficiently recovered by adding a suitable precipitant such as ethanol or isopropanol. [0064] Purification can also be carried out by desalting the filtrate or the supernatant after centrifugation using an ion exchange resin and, if necessary, decolorizing it with activated carbon. [0065]

【Example】

Hereinafter, the present invention will be explained in more detail with reference to Examples and Application Examples. [0066] Example 1 Bacterial strain KAB55 (Feikoken Contract No. 9366) belonging to the genus Macrophomopsis was precultured for 3 days in a medium with the following composition, and 6 ml of this was added to a 500-ml culture medium containing 100 ml of a medium with the same composition.
The cells were inoculated into a m1 Erlenmeyer flask and cultured at 25° C. for 4 days with rotation at 120 revolutions/minute. [0067] (Composition) Glucose 100g
Pharmame di a 5
gKH2P04 1g Mg50 ・7HO3g Tap water 1 liter (N
(adjusted to pH 6 with aOH) [0068] The obtained culture solution was centrifuged at 8000 rpm for 20 minutes to remove bacterial cells, and an equal amount of 40% isopropanol was added to the supernatant to precipitate polysaccharides. I let it happen. Rotate this 10,000 times/
The polysaccharide was obtained by centrifugation for 5 minutes and 5 minutes. The obtained polysaccharide was dissolved in water again and the above operation was repeated to obtain 0.22 g of a tasteless, odorless and white highly viscous polysaccharide. [0069] Various measurements were performed on this polysaccharide to determine its physical and chemical properties. The results are as already described. [0070] Example 2 50 liter jar fermenter (manufactured by Mitsuwa Bio)
Add 30 liters of the following medium to the tank, inoculate 1 liter of KAB55 pre-cultured in the same manner as in Example 1, and heat at 25°C.
Amount of ventilation 1. Cultured in Ovvm for 4 days. [0071] (Composition) Glucose 3000
gPharmamedia 150gKH2
PO430g Mg5O・7H2090g Tap water 30 liters (N
(adjusted to pH 6 with aOH) [0072] The obtained culture solution was subjected to continuous centrifugation at 10,000 rpm to remove bacterial cells, and an equal volume of 60% ethanol was added to the obtained supernatant to precipitate polysaccharides. . This was purified by the same procedure as in Example 1, and a tasteless, odorless, white, highly viscous polysaccharide 2 was obtained.
5g was obtained. [0073] Example 3 KAB55 was precultured for 3 days in a medium with the following composition, and the entire amount was inoculated into a 50 liter jar fermentor containing 30 liters of a medium with the same composition, and the mixture was incubated at 25° C. with 1 aeration. Culture was carried out for 4 days at a volume of 1.5 vvm. [0074] (Composition) Glucose 50
gPh a rma me di a 10g KH2PO41g Mg50 ・7H203g Tap water 1 liter (N
(adjusted to pH 6 with aOH) [0075] The supernatant obtained by separating and removing the bacterial cells from this culture solution by centrifugation (10,00 Orpm, 12 minutes) was used as a mobile phase for 5 mL.
Asahipak with 0mM sodium chloride solution
When subjected to high performance liquid chromatography using a G5-710 column, as shown in Figure 3(A), in addition to the peak due to a substance with a molecular weight of 10 million daltons (β-glucan), there was a peak due to a substance with a molecular weight of 1 million daltons. A peak due to Dalton's substance (α-glucan) was observed. [0076] The yield of β-glucan at this time was 45 g, based on a calibration curve using β-glucan of a known concentration. [0077] Example 4 An experiment was conducted in the same manner as in Example 3, except that the composition of the medium was changed as follows. [0078] (Composition) Lactose 50
gPharmamedia 10gKH2
PO41g M g S O4・7 H203g Tap water 1 liter (N
(adjusted to pH 6 with aOH) [0079] In this case, centrifugation for bacterial cell isolation was performed at 10.00 Orp.
The separation was easier than in Example 3, as it only took m·5 minutes. [00801 In addition, when subjected to high performance liquid chromatography in the same manner as in Example 3, as shown in FIG. A peak derived from α-glucan near 1 million daltons was not observed. [0081] The yield of β-glucan at this time was 51 g based on the calibration curve. [0082] Application examples, comparative examples - Emulsion formulation Composition 1 formulation Amount 1 (wt%) 1 oil 1 liquid paraffin octyldodecyl myristate phase Cetyl alcohol monostearate glycerin 10.01 5.0 2.0 1, O Propylene glycol water I Sodium cetyl sulfate Methyl paraoxybenzoate Phase 1 Purified polysaccharide water of the present invention [0083] (2) Preparation method Quickly cool while stirring to obtain a milky lotion containing the polysaccharide of the present invention. Ta. [0084] As a comparative example, emulsions were similarly prepared using existing xanthan gum instead of the polysaccharide of the present invention, and these were used in the following sensory test. [0085] (Sensory test) Approximately 0.5 g of the above-mentioned application example and comparative emulsions were applied to each side of the left and right sides of the face to 20 female subjects. The evaluation item of "skin smoothness" was evaluated by the test subjects themselves using the paired comparison method. [0086] (3) Test Results The results of a comparison between the above application example and comparative example are shown in the table below. [0087] Evaluation item 1 [Feeling of stickiness is 1. “Skin smoothness” 1. “Skin smoothness” 1. There is a feeling.” Applied example is better 1 17 people 1 13 people 1 Applied example and comparative example are the same 1 3 people 1 7 people 1 Comparative example is better 1 0 people 1 0 people [00
88] As is clear from the table, application examples (containing the polysaccharide of the present invention)
Compared to the comparative example (containing existing xanthan gum), it had a light and fresh feel with no sticky feeling. [0089]

【Effect of the invention】

As described above, the present invention provides a polysaccharide (β-glucan) that can be used as a thickener, emulsifier, stability agent, and humectant in the fields of foods, cosmetics, etc., and a method for producing the same. It is. [0090] Furthermore, if a sugar containing galactose as a backbone is used as a carbon source, it is possible to selectively produce only β-glucan, which can be used to isolate bacterial cells. Labor and effort can be reduced considerably.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an infrared absorption spectrum of the polysaccharide of the present invention. In addition, in FIG. 1, the wavelength and absorbance of the peaks indicated by OO to 15 are as follows. Wavelength (cm) Absorbance 00 3421.14 0.164401
1652.72 0.064302
1641.15 0.064803
1430.94 0.089004 13
73.09 0.090005 1317
．． 16 0.082406 1253.5
2 0.082407 1201.45
0.089408 1160.95
0.108809 1076.10 0
．． 132210 890.96 0.0
55111 624.83 0.0,7
0312 570.83 0.0773
13 566.98 0.077314
460.91 0.070215
418.48 0.0643

[Figure 2]

FIG. 3 (A) shows the high performance liquid chromatography pattern of Example 3, and (X/) shows the high performance liquid chromatography pattern of Example 4.

[Explanation of symbols]

■ Peak derived from β-glucan ■ Peak derived from α-glucan (B

[Document base]

[Figure 1] drawing

[Figure 2] ↑

[Figure 3]

Claims (4)

[Claims] 1. A highly viscous β-glucan characterized by having the following properties: (a) The bonding pattern is that all the D-glucopyranosyl residues in the main chain are β-1,3 bonds, and the D-glucopyranosyl residues in the main chain are branched at the C-6 position, and A β-glucan having one β-1,6-linked D-glucopyranosyl residue as a side chain for every four β-1,3-linked D-glucopyranosyl residues. (b) has a molecular weight of about 10 million daltons or more as determined by high performance liquid chromatography using a molecular sieve column; (c) The temperature dependence of viscosity is such that at a concentration of 0.3% by weight or less, the viscosity is constant between 5°C and 85°C;
It has a constant viscosity between 20°C and 85°C even at concentrations exceeding 3% by weight. (d) The viscosity is stable even when heated at 121° C. in an autoclave at 1 kg/cm^2 (20 minutes). Claim 2: Macrophomopsis (¥Macropho
A method for producing β-glucan, which comprises culturing a microorganism belonging to the genus P. mopsis and collecting the β-glucan according to claim 1 from the culture. 3. The β-saccharide according to claim 2, characterized in that a sugar containing galactose as a backbone is used as a carbon source in the cultivation of a microorganism belonging to the genus Macrophomopsis.
Method for producing glucan. 4. The method for producing β-glucan according to claim 3, wherein the sugar containing galactose as a backbone is lactose.