JPS6219838B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for immobilizing yeast having alcoholic fermentation ability, and more particularly to a method for immobilizing yeast having alcoholic fermentation ability as a granular molded product.

Many methods have been known for immobilizing microorganisms, including entrapment methods, physical adsorption methods, and covalent bonding methods. When the immobilized material obtained by these methods is used in a microbial reaction, it is usually cut into small pieces or ground and then packed into a column. However, in that case, the immobilized objects often come into close contact with each other,
There are also disadvantages such as the efficiency of the microbial reaction is reduced and channeling phenomenon often occurs, clogging the column.

The present inventors believe that if microbial cells can be immobilized in the form of granular moldings, they will be fluid and easy to fill into columns, and the contact area between particles will be small, increasing the efficiency of microbial reactions. As a result of intensive research into a method of immobilizing microbial cells in the form of granular moldings, we discovered that a type of hydrophilic photocurable resin used as an immobilization carrier has the ability to gel when brought into contact with polyvalent metal ions. The present invention has been based on the discovery that a granular immobilized product with high mechanical strength can be produced extremely easily from an aqueous medium without loss of microbial cells by using a combination with a certain water-soluble polymeric polysaccharide. I was able to complete it.

Therefore, according to the present invention, (a) a hydrophilic curable resin having at least two ethylenically unsaturated bonds in one molecule, (b) a photopolymerization initiator, and (c) a combination with a polyvalent metal ion. A liquid composition comprising a water-soluble polymeric polysaccharide capable of gelling upon contact and (d) yeast capable of exerting alcoholic fermentation power is dropped into an aqueous medium containing polyvalent metal ions. A granular immobilized molded product of yeast having alcoholic fermentation ability, characterized in that the composition is gelatinized into granules, and then the resulting granular gel is irradiated with actinic rays to cure the photocurable resin in the granular gel. A manufacturing method is provided.

The method of the present invention will be explained in more detail below.

(a) Hydrophilic photocurable resin In the method of the present invention, a hydrophilic photocurable resin having at least two ethylenically unsaturated bonds in one molecule is used as one of the immobilization carriers. The photocurable resin is generally 300
~30,000, preferably in the range of 500 to 20,000, and sufficient ionic or nonionic hydrophilicity to uniformly disperse the microbial cells in the aqueous medium in which they are suspended. When it contains groups such as hydroxyl groups, carboxyl groups, phosphoric acid groups, sulfonic acid groups, amino groups, ether bonds, etc., and is irradiated with actinic light having a wavelength in the range of about 250 to about 600 nm, it hardens and becomes substantially soluble in water. It is preferable to use a material that is a substitute for a physically insoluble resin. Such photocurable resins are already known as immobilization carriers for enzymes or microbial cells (for example, Japanese Patent Publication No. 55-40, Japanese Patent Publication No. 55-20676).
(Refer to Japanese Patent Publications, etc.), and the following are typical examples: (i) High acid value unsaturated polyesters: For example, maleic anhydride, maleic acid, fumaric acid, itaconic acid, itaconic anhydride. at least one unsaturated polyhydric carboxylic acid such as an acid, trimellitic acid, trimellitic anhydride, pyromellitic acid,
Salts of unsaturated polyesters having an acid value within the range of 40 to 200 obtained by esterifying a polycarboxylic acid component consisting of at least one saturated polycarboxylic acid such as pyromellitic anhydride with a polyhydric alcohol; At least 5% by weight of at least one unsaturated polyhydric carboxylic acid such as maleic anhydride, maleic acid, fumaric acid, itaconic acid, and itaconic anhydride, and a polyhydric alcohol having more than 3 hydroxyl groups in one molecule. Unsaturated polyesters with an acid value within the range of 40 to 200 obtained by reacting an acid anhydride with the residual hydroxyl group in the esterified product with a polyhydric alcohol component.

(ii) Highly oxidized unsaturated epoxides: polyglycidyl compounds such as Epicote 828, Epicote 1001, and Epicote 1004 manufactured by Ciel Chemical Co., Ltd.
Hydroxyl residue remaining in the addition reaction product of n equivalents such as and (n-1) equivalents of a polyhydric carboxylic acid, such as maleic acid, adipic acid, trimellitic acid, etc., and 2 equivalents of an unsaturated carboxyl compound such as (meth)acrylic acid. Unsaturated epoxides with an acid value within the range of 40 to 200 obtained by adding an acid anhydride to the group; addition reaction between n equivalents of the above polyglycidyl compound and (n+2) equivalents of the above polyhydric carboxylic acid Unsaturated epoxides with an acid value of 40 to 200 are obtained by reacting an unsaturated glycidyl compound such as glycidyl (meth)acrylate with a compound obtained by adding an acid anhydride to the hydroxyl groups remaining in a substance.

(iii) Anionic unsaturated acrylic resins; the anionic unsaturated acrylic resins are at least two (meth)acrylic acid esters selected from (meth)acrylic acid and (meth)acrylic ester.
It is a resin in which a photopolymerizable ethylenically unsaturated group is introduced into a copolymer containing a carboxyl group, a phosphoric acid group and/or a sulfonic acid group obtained by copolymerizing an acrylic monomer, and it has the following formula: C+5P+10S=A (1) [In the formula, C is the concentration of carboxyl groups in the resin (mol/Kg), P is the concentration of phosphoric acid groups in the resin (mol/Kg), and S is the concentration of sulfonic acid groups in the resin. (mol/Kg)] The value of A calculated by is 0.8 to 5 (mol/Kg).
Kg), and the concentration of photopolymerizable ethylenically unsaturated groups in the resin is from 0.1 to
5 (mol/Kg).
Such a copolymer can be synthesized by a known method. In this case, if an unsaturated carboxylic acid such as acrylic acid or methacrylic acid is used as a comonomer, a copolymer containing a carboxyl group can be obtained, and a copolymer containing a carboxyl group can be obtained by using a phosmer as a comonomer. M,
Hosmer Cl [both manufactured by Yushi Products Co., Ltd.]
A copolymer containing a phosphoric acid group can be obtained by using an unsaturated phosphoric acid ester such as If a saturated sulfonic acid ester is used, a copolymer containing sulfonic acid groups can be obtained. In order to introduce a photopolymerizable ethylenically unsaturated group into the copolymer thus obtained, glycidyl (meth)acrylate or the like is added to the carboxyl group, phosphoric acid group or sulfonic acid group present in the copolymer. This is possible by reacting unsaturated glycidyl compounds.

(iv) Cationic unsaturated acrylic resin: e.g.
Copolymers of (meth)acrylic acid esters containing more than 5% by weight of unsaturated amino compounds such as 2-diethylaminoethyl (meth)acrylate, tert-butylaminoethyl (meth)acrylate, and vinylpyridine. unsaturated acrylic resin obtained by reacting unsaturated glycidyl compounds such as glycidyl (meth)acrylate; unsaturated acrylic resin obtained by chloromethylating polystyrene and then quaternizing it with an unsaturated amino compound; polyethylene Adducts of imines and unsaturated glycidyl compounds, etc.

(v) Polyesters of polyethylene glycol and (meth)acrylic acid: e.g.
Diesters of unsaturated monocarboxylic acids such as (meth)acrylic acid of polyethylene glycol containing from 400 to 10,000 and less than 30% by weight of propylene oxide groups; molecular weight of n moles of a dibasic acid such as maleic anhydride and (n+1) moles. 600〜
Esterified product of an unsaturated monocarboxylic acid such as 10000 polyethylene glycol and 2 moles (meth)acrylic acid; molecular weight of n moles tribasic acid such as trimellitic acid and n+2 moles
600-10000 polyethylene glycol and 3 mol esters of unsaturated carboxylic acids such as (meth)acrylic acid, etc.

(vi) Urethane adducts of polyethylene glycol and 2-hydroxyethyl (meth)acrylate: for example, n moles of diisocyanate such as tolylene diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate and (n-1) moles of diisocyanate; Molecular weight 800~
10,000 polyethylene glycol and 2 mol of an unsaturated monohydroxy compound such as 2-hydroxyethyl (meth)acrylate; n mol of a triisocyanate such as Desmodyur L (Bayer AG) and (n-1) mol. Urethane compound with polyethylene glycol having a molecular weight of 800 to 10,000 and (n+2) moles of an unsaturated monohydroxy compound such as 2-hydroxyethyl (meth)acrylate; 1 mole of a trifunctional hydroxy compound such as trimethylolpropane and 4 moles and 2 moles of polyethylene glycol having a molecular weight of 400 to 10,000 and 2 moles of an unsaturated monohydroxy compound such as 2-hydroxyethyl (meth)acrylate.

(vii) Unsaturated celluloses: For example, water-soluble cellulose such as cellulose acetate phthalate, hydroxypropyl methyl cellulose phthalate, hydroxyethyl cellulose, unsaturated glycidyl compounds such as glycidyl (meth)acrylate, or itaconic anhydride, maleic anhydride, etc. Addition reaction product with unsaturated acid anhydride.

(viii) Unsaturated polyamide: For example, an adduct of 1 mol of a diisocyanate such as tolylene diisocyanate or xylylene diisocyanate and 1 mol of an unsaturated hydroxy compound such as 2-hydroxyethyl acrylate is added to a water-soluble polyamide such as gelatin. Unsaturated polyamide subjected to addition reaction.

The photocurable resins exemplified above can be used alone, or in combination of two or more. Among these photocurable resins, those that can be particularly advantageously used in the present invention include polyesters of polyethylene glycol and (meth)acrylic acid (v) and polyesters of polyethylene glycol and (meth)acrylic acid (vi). Mention may be made of urethanized adducts with 2-hydroxyethyl acid.

(b) Photopolymerization initiator For the purpose of promoting the photopolymerization reaction of the photocurable resin described in (a) above, the liquid composition according to the present invention contains a photopolymerization initiator (photosensitizer). The photopolymerization initiators that can be used are those that decompose by light irradiation to generate radicals, which act as polymerization initiation species to cause a cross-linking reaction between resins having polymerizable unsaturated groups, such as benzoin, α-Carbonyl alcohols such as acetoin; Acilloin ethers such as benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, anisoin ethyl ether, pivaloin ethyl ether; Polycyclic aromatic compounds such as naphthol and hydroxyanthracene α-substituted acyloins such as methylbenzoin and α-methoxybenzoin; 2-cyano-
Examples include azoamide compounds such as 2-butylazoformamide; metal salts such as lauryl nitrate and ferric chloride; mercaptans; disulfides; halogen compounds; dyes and the like.

These photopolymerization initiators are used alone or in combination of two or more, and usually have a concentration of 0.01 to 10 pHR (per hundred pHR).
Resin) can be used.

(c) Water-soluble polymeric polysaccharide In the method of the present invention, in order to achieve gelation of an enzyme or microbial cell immobilization carrier in an aqueous medium, the immobilization carrier is used as described in the preceding paragraph (a). One major feature is the use of a water-soluble polymeric polysaccharide in combination with a photocurable resin.

The water-soluble polymeric polysaccharide used in the present invention is a polymeric polysaccharide that is water-soluble and has the ability to change into a gel that is insoluble or poorly soluble in water when it comes into contact with polyvalent metal ions in an aqueous medium. , generally has a molecular weight of about 3,000 to about 2,000,000, and
Those which normally exhibit a solubility of at least about 10 g/(25° C.) in a water-soluble state before being brought into contact with polyvalent metal ions are preferably used.

Specific examples of water-soluble polymeric polysaccharides having such properties include alkali metal salts of alginic acid, carrageenan, konjac mannan, and the like.

These water-soluble polymeric polysaccharides, while dissolved in a water-soluble medium, contain polyvalent metal ions, such as alkaline earth metal ions such as magnesium ions, calcium ions, strontium ions, and barium ions, or aluminum ions, cerium ions, and nickel. When contacted with at least one polyvalent metal ion among other polyvalent metal ions such as ions, it may gel. It should be noted that the water-soluble polymeric polysaccharide that can be used in the present invention does not need to have gelling ability upon contact with all polyvalent metal ions, but at least one type of polyvalent metal ion, preferably It is sufficient that it has the ability to gel when contacted with alkaline earth metal ions. The concentration of polyvalent metal ions at which gelation occurs varies depending on the type of water-soluble polymeric polysaccharide, but is generally at least 0.01 mol/.

(d) Yeast with alcoholic fermentation ability There is no particular restriction on the type of yeast with alcoholic fermentation ability that can be immobilized by the method of the present invention, and according to the method of the present invention, any type of yeast with alcoholic fermentation ability can be immobilized by the method of the present invention. Yeast can also be immobilized without substantially deactivating its alcoholic fermentation ability.

Therefore, the yeast having alcoholic fermentation ability that can be immobilized by the method of the present invention is not particularly limited, and examples thereof include Saccharomyces formosensis, Saccharomyces cerevisiae, and Saccharomyces formosensis.
cerevisiae), Saccharomyces carlsbergensis, Saccharomyces robustus
robustus), Saccharomyces rouxii, Zygosaccharomyces japonicus
japonicus), Zygosaccharomyces majar, Zygosaccharomyces soya,
These include Schizosaccharomyces pmbo, Schizosaccharomyces octosporus, and Schizosaccharomyces mellacei. These may be used alone or in a mixture of two or more, or in some cases may be used alone and simultaneously.

Preparation of liquid composition: Each of the components (a), (b), (c) and (d) described above can be made into a liquid composition by sufficiently mixing them with each other in an aqueous medium. . The aqueous medium that can be used is preferably water or an aqueous buffer solution, but in some cases, a mixture of water-soluble alcohols and water or an aqueous buffer solution, or a mixture of water-soluble ketones and water or an aqueous buffer solution. It is also possible to use an ester solvent solution that can be uniformly mixed with water or an aqueous buffer solution.

The mutual usage ratio of each component (a), (b), (c) and (d) above is not strictly limited and can be varied over a wide range depending on the type of each component, etc. However, in general, 100% of the hydrophilic photocurable resin of component (a)
It is appropriate to use the following content based on parts by weight (within the preferred range).

(b) Photopolymerization initiator: 0.5 to 5 parts by weight (1 to 3 parts by weight) (c) Water-soluble polymeric polysaccharide: 0.5 to 15 parts by weight (1 to 3 parts by weight)
(8 parts by weight) (d) Yeast with alcoholic fermentation ability: 0.001-50
Parts by weight (0.01 to 20 parts by weight) In addition, the aqueous medium is 10 parts to the total of (a) to (d) above.
~1500 parts by weight (50-900 parts by weight) can be used.

Gelation: The liquid composition prepared as described above is then gelled into particles by dropping it into an aqueous medium containing polyvalent metal ions.

As the polyvalent metal ion that can be included in the aqueous medium, one is selected that has the ability to gel the water-soluble polymeric polysaccharide in the liquid composition. At that time, whether or not the polyvalent metal ion has the ability to gel the water-soluble polymeric polysaccharide is determined by, for example, a mixture uniformly containing a hydrophilic photocurable resin and a water-soluble polymeric polysaccharide. This can be easily determined by dropping an aqueous solution into the polyvalent metal ion liquid and observing whether it gels into particles.

Preparation of an aqueous medium containing selected polyvalent metal ions involves adding water-soluble compounds of the polyvalent metal, such as halides, carbonates, etc. of the polyvalent metal, into the aqueous medium.
This can be done by dissolving hydrogen carbonate, sulfate, nitrate, etc. At that time, the concentration of polyvalent metal ions in the aqueous medium is generally 0.01 to 5 mol/
, preferably within the range of 0.1 to 2 mol/.

Dropping of the liquid composition into the aqueous medium containing such polyvalent metal ions can be carried out, for example, by dropping the liquid composition from the tip of a tube with a narrow tip such as a syringe needle, or by using centrifugal force. This can be carried out by methods such as scattering the liquid composition into particles, or atomizing the liquid composition into particles and dropping the liquid composition dropwise from the tip of a spray nozzle. The size of the droplets dropped can be varied freely depending on the desired particle size of the final granular fixation material, but typically the diameter is approximately
Conveniently, the droplets are applied in droplets of 0.1 to about 5 mm, preferably about 0.5 to about 3 mm.

The dropped liquid composition contacts polyvalent metal ions in an aqueous medium and immediately gels to form a granular gel.

Room temperature is usually sufficient for the above gelation temperature, but
If necessary, gelation may be carried out under heating to an extent that yeast having alcoholic fermentation ability is not inactivated, or may be carried out under cooling.

Photo-curing: The granular gel produced as described above can be directly dispersed in an aqueous medium, or after being separated from the aqueous medium, it can be irradiated with active light to photo-cure the hydrophilic properties in the granular gel. harden the resin. As a result, the granular gel is obtained as a granular immobilized yeast substance that is substantially insoluble in water, has high mechanical strength, and has alcoholic fermentation ability.

The wavelength of the active light that can be used for the above photocuring differs depending on the type of photocurable resin contained in the granular gel, but generally a light source that emits light with a wavelength in the range of about 250 to about 600 nm is used. Advantageously, it is used for irradiation. Examples of such light sources include low pressure mercury lamps, high pressure mercury lamps, fluorescent lamps, xenon lamps, carbon arc lamps, sunlight, and the like. The irradiation time needs to be changed depending on the light intensity of the light source, the distance from the light source, etc., but can generally be within a range of about 0.5 to about 10 minutes. Note that the irradiation time may be shortened if the irradiation is performed in an inert gas atmosphere.

Irradiation should be done so that the actinic rays are distributed as evenly as possible to all the granular gels that have been formed. For example, when irradiating active rays to granular gels that have been separated from an aqueous medium, the separated granular gels are It is convenient to arrange the irradiation material in substantially a single layer in a suitable transparent glass plate or glass container and to irradiate the glass plate or glass container both from above and from below.

The granular gel that has been irradiated in this manner can be washed with water or an aqueous buffer solution and stored as is, or the granular gel can be lyophilized and stored.

Thus, according to the present invention, a granular immobilized yeast product having a particle size of about 0.5 to about 5 mm and having alcoholic fermentation ability can be produced by an extremely simple operation, and continuous production is also possible.

According to the method of the present invention, it has become possible to immobilize yeast with alcoholic fermentation power in granular form using a synthetic carrier, which has been difficult until now, and yeast with alcoholic fermentation power can be obtained by using water-soluble polymeric polysaccharides. It is possible to achieve a protective effect on the activity of the water-soluble polymeric polysaccharide, and to improve the reaction rate due to the increase in substrate permeability due to the fine porosity imparted to the granular immobilized material when the water-soluble polymeric polysaccharide is decomposed. Benefits such as:

In addition, these granular immobilized products can be easily used particularly in reactors whose scale is not very large, fluidized bed type reactors, and the like.

Next, the present invention will be further explained using examples.

Example 1 2000g of polyethylene glycol with a molecular weight of approximately 4000
and isophorone diisocyanate 1 mol (222 g)
and a photocurable resin (resin) consisting of a mixture of 1 mole (130 g) of 2-hydroxyethyl methacrylate
100 parts by weight of prepolymer, 2 parts by weight of benzoin isobutyl ether and 100 parts by weight of distilled water are thoroughly mixed. To this, 100 parts by weight of a 2% sodium alginate aqueous solution and 100 parts by weight of Saccharomyces cerevisiae (ATCC 11909) bacterial cell suspension (10% concentration) were added and mixed well. When the solution was dropped into a calcium chloride solution from a height of 10 cm from the liquid level through the injection needle at the tip of the syringe, granules with a diameter of about 2 mm were obtained.

Place this granular material in a Petri dish with a flat bottom, and apply a wavelength of 300 to 400 nm from the top and bottom surfaces of the Petri dish.
Compressive strength was 20 when exposed to active light of m for 3 minutes.
Kg/cm ² of granular immobilized yeast was obtained.

The granular immobilized yeast obtained in this way was subjected to an alcohol fermentation test using the method below.
The concentration of ethanol produced was 7.5%. When unimmobilized Satucharomyces cerevisiae was used, it was 7.2%.

Alcohol fermentation test: 20% molasses medium containing 3 g of granular immobilized yeast and 0.5% ammonium sulfate in a 100 ml Erlenmeyer flask with a wire stopper.
ml and cultured for 24 hours at 30°C to obtain fermented mash. 1 μm of this mash is collected using a microsyringe, and the concentration of alcohol produced is measured using a gas chromatograph.

Example 2 Polyethylene glycol 2000 (molecular weight 2000)
Add 100 parts by weight of distilled water to 100 parts by weight of a photocurable (resin) prepolymer consisting of 1000 g and 2 moles of methyl methacrylate, heat to about 50°C and mix thoroughly to make a uniform aqueous resin solution. 2 parts by weight of benzoin ethyl ether was added and mixed and dissolved.

Add 3% k-carrageenan aqueous solution to this resin mixture.
75 parts by weight and 25 parts by weight of Satucharomyces callusbergensis (ATCC9080) bacterial cell suspension (10% concentration) were added to prepare a uniform mixed solution. When this homogeneous mixed solution was dropped from the tip of a syringe needle into a 5% potassium chloride aqueous solution from a position 20 cm from the liquid surface, the particle size was
1.5 granules were obtained.

The granules were transferred to a Petri dish with a flat bottom in a single layer along with the potassium chloride solution, and placed at a depth of 2
When the granules were present in an aqueous solution of 30 mm in size and irradiated with actinic light having a wavelength of 300 to 400 nm for 3 minutes from the top surface and 3 minutes from the bottom surface, granular immobilized yeast with a compressive strength of 30 Kg/cm ² was obtained.

An alcohol fermentation test was performed on the granular immobilized yeast thus obtained, and the resulting ethanol concentration was 10.8%. When yeast without immobilization was used, it was 10.5%. The alcohol fermentation test was conducted in the same manner as in Example 1, except that a 25% molasses medium was used and the static culture time was 36 hours.

Example 3 1 mole of Epicoat 1001 resin (molecular weight: about 900, epoxy equivalent: about 475, manufactured by Shell Chemical Co., Ltd., trade name) was reacted with 1.5 moles of adipic acid, and then esterified with 4.5 moles of succinic anhydride, followed by 2.75 moles of glycidyl methacrylate. Add 1 part by weight of benzoin ethyl ether to 100 parts by weight of a resin liquid (solid content 50%) obtained by neutralizing a photocurable resin with an acid value of 75 (number average molecular weight approximately 4100) with caustic soda. Mix parts by weight uniformly, and further add 50 parts by weight of 3% sodium alginate aqueous solution and bacterial cell paste of Satucharomyces robustan (IFO0224).
1.0 part by weight (30% concentration) was uniformly mixed and dispersed.
Thereafter, when the dispersion was dropped into a 1.0M aluminum chloride solution from the tip of a syringe, it gelled into a spherical shape. When the spherical gel was transferred to a Petri dish and irradiated with actinic light with a wavelength of 300 to 400 nm for 3 minutes from the top and bottom of the Petri dish, the diameter was 3 mm.
A spherical immobilized yeast with a compressive strength of 26 kg/cm ² was obtained.

Using this granular immobilized yeast, an alcohol yeast test was conducted in the same manner as in Example 1. As a result, the concentration of ethanol produced was 6.8%.

Example 4 300 parts by weight of ethyl acrylate, methacrylic acid
100 parts by weight, 80 parts by weight of styrene, 20 parts by weight of Phosmer M [methacrylate phosphate monoester, manufactured by Yushi Products Co., Ltd.], and glycidyl methacrylate.
The number average molecular weight of 50 parts by weight of the copolymer is approximately
2 parts by weight of benzoin isobutyl ether were added to 90 parts by weight of a resin liquid (solid content 75%) obtained by neutralizing 25,000 photocurable resin with caustic potassium and mixed uniformly. To this mixture, 50 parts by weight of a 3% sodium alginate aqueous solution and 50 parts by weight of a bacterial cell suspension (10% concentration) of Satucharomyces phorumocensis (IFO0216) were uniformly mixed, and the resulting resin mixture was poured into a syringe. When dropped from the tip into a Petri dish containing 10% ammonia alum aqueous solution, it gelled into particles. This granular gel has a wavelength of 300~ from the top and bottom surfaces.
When irradiated with 400nm active light for 3 minutes each,
A granular immobilized yeast with a diameter of about 2 mm and a compressive strength of 18 Kg/cm ² was obtained.

Using this granular immobilized yeast, an alcohol fermentation test was conducted in the same manner as in Example 1, and the resulting ethanol concentration was 7.0%.

Example 5 500g of polyvinyl alcohol with a degree of polymerization of 500,
0.5 parts by weight of benzoin isobutyl ether was uniformly mixed with 100 parts by weight of a 25% aqueous solution of a photocurable resin obtained by adding 1.0 mol of N-methylol acrylamide, and 100 parts by weight of a 3% aqueous k-carrageenan solution and digosatucaromi were added. 10 parts by weight of a bacterial cell suspension (10% concentration) of Seth japonicus (ATCC11069) were uniformly mixed and dispersed. The thus obtained photocurable resin-yeast mixture is supplied onto a rotating disk,
The mixed resin liquid was scattered by the centrifugal force, and the scattered particles were dropped into a 0.5 molar potassium chloride solution and gelled into particles. This was placed in a Petri dish and irradiated with 300 to 400 nm light for 3 minutes from the top and bottom at the same time, resulting in a diameter of 3 mm and a compressive strength of 15 kg/
cm ² granular immobilized yeast were obtained.

Using this granular immobilized yeast, an alcohol fermentation test was conducted in the same manner as in Example 1, and the resulting ethanol concentration was 5.7%.

Claims (1)

[Scope of Claims] 1 (a) a hydrophilic photocurable resin having at least two ethylenically unsaturated bonds in one molecule, (b) a photopolymerization initiator, (c) at least one polyvalent metal A liquid composition comprising a water-soluble polymeric polysaccharide capable of gelling upon contact with ions, and (d) yeast having alcoholic fermentation ability is dropped into an aqueous medium containing polyvalent metal ions. granular immobilization of yeast having alcoholic fermentation ability, characterized in that the composition is gelatinized into granules, and then the resulting granular gel is irradiated with actinic rays to cure the photocurable resin in the granular gel. Method for manufacturing molded products.