JP2710816B2 - Biocatalyst-immobilized polyvinyl alcohol gel fiber and method for producing the same - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a biocatalyst-immobilized polyvinyl alcohol gel fiber and a method for producing the same, and more particularly, to a gel base comprising polyvinyl alcohol and a water-soluble polymer polysaccharide. ,
The present invention relates to a biocatalyst-immobilized polyvinyl alcohol gel fiber comprising a biocatalyst and water, and a simple production method thereof.

The biocatalyst-immobilized polyvinyl alcohol gel-like fiber of the present invention has excellent abrasion resistance, and a biocatalyst such as a microorganism and an enzyme entrapped and immobilized therein can efficiently exhibit its activity. It is useful as an immobilized biocatalyst.

B. Conventional Technology Polyvinyl alcohol (hereinafter sometimes abbreviated as PVA) fiber is described in, for example, “Polyvinyl Alcohol Fiber” by Sakurada.
s)] [1985, Marcel Dekker, USA
er), a method of extruding an aqueous PVA solution into an aqueous solution containing a high concentration of salts such as sodium sulfate to cause dehydration and coagulation, and a coagulation solution of an alkali salt after adding boric acid to PVA. It has been obtained by a method of coagulating while forming a cross-linking point of PVA by extruding it inside, a method of spinning while extruding PVA into a high-concentration alkaline coagulation bath and gelling.

C. Problems to be Solved by the Invention In the above method, in order to increase the strength of the gel during coagulation,
It is necessary to increase the PVA concentration in the PVA aqueous solution and the salt concentration in the coagulation liquid, and therefore, the temperature of the PVA aqueous solution is set to 90 to 110 ° C.
It was necessary to reach a high temperature. When trying to entrap biocatalysts such as microorganisms in PVA gel fibers,
The above method of contacting a high-temperature aqueous PVA solution with a coagulating solution containing a high concentration of salt cannot be used because the biocatalyst is placed in an excessive environment. Furthermore, the PVA gel obtained by using a high-concentration PVA aqueous solution has a low water content, but the biocatalyst entrapped and immobilized in the PVA gel having such a low water content can sufficiently enhance its biological activity. Can not demonstrate.

Gel fibers with immobilized biocatalyst do not cause separation problems when used in bioreactors, such as when using gel particles with immobilized biocatalysts. Although it has an advantage, such a gel fiber is required to satisfy the following conditions in order to be put to practical use.

(1) Regarding fiber properties, it must have fiber strength, water resistance, and abrasion resistance as a fluidized bed reactor.

(2) In terms of function, the activity of the inclusive biocatalyst inside the fiber is not lost, the activity of restoring from the dormant state is fast, the growth of cells in the carrier is possible, and the affinity for the biocatalyst is high. High permeability, high moisture content, good permeability of substrate and oxygen from outside.

However, in reality, gel fibers immobilized with a biocatalyst satisfying these conditions have not yet been obtained.

Therefore, an object of the present invention is to provide a biocatalyst-immobilized PVA gel fiber satisfying the above conditions, and to provide a simple method for producing the biocatalyst-immobilized PVA gel fiber. is there.

D. Means for Solving the Problems According to the present invention, the object described above is to provide (a) an inner film made of polyvinyl alcohol and a water-soluble polysaccharide and an outer film, and an average of the inner film in a dry state. The thickness is in the range of 0.005 to 0.20 μm, the average thickness of the outer coating is in the range of 0.1 to 10 μm, and the average maximum diameter of the inner coating or the space formed by the inner coating and the outer coating is A gel base material in the range of 0.1 to 10 μm, (b) a biocatalyst entrapped and immobilized inside the gel base material, and (c)
A water-soluble polymer which is achieved by providing a biocatalyst-immobilized polyvinyl alcohol gel fiber characterized by comprising water, and which has a gelling ability upon contact with a biocatalyst, polyvinyl alcohol and a cation. The mixed aqueous solution containing the polysaccharide is discharged and brought into contact with an aqueous solution containing a compound containing a cation to form the mixed aqueous solution into a fibrous form. The present invention is attained by providing a method for producing the biocatalyst-immobilized polyvinyl alcohol gel-like fiber, which comprises performing at least one treatment comprising the following freezing and subsequent thawing.

The gel base material constituting the gel-like fiber of the present invention is composed of PVA and a water-soluble polymer polysaccharide. The PVA has an average degree of polymerization of 1,000 or more, preferably 1700 or more, and a saponification degree of 98.5%. As described above, completely saponified PVA having a degree of saponification of preferably 99.85 mol% or more is desirable for formation of a PVA gel. As described below, the gel-like fiber of the present invention is formed through a freezing step.However, when the saponification degree of the PVA used is reduced, the freezing conditions of the gel molding become severe, and in order to obtain a gel having a necessary strength, Since a lower freezing temperature and a lower freezing time are required, it is not preferable in terms of productivity. Also, as PVA,
Various known modified PVAs can be used as long as the object of the present invention is not inhibited. Examples of the water-soluble high molecular weight polysaccharide which is another polymer component constituting the gel base include, specifically, a gel formed by contact with a cation such as an alkali metal salt of alginic acid, carrageenan, mannan or chitosan. And water-soluble high-molecular-weight polysaccharides having the ability to be converted. The water-soluble polymer polysaccharides include alkaline earth metal ions such as magnesium ion, calcium ion, strontium ion and barium ion; other polyvalent metal ions such as aluminum ion, cerium ion and nickel ion; potassium ion; sodium ion It may be present together with a cation capable of gelling the above-mentioned water-soluble polysaccharide such as ammonium ion. The polymerization ratio of PVA to the water-soluble polysaccharide is preferably in the range of 35:65 to 95: 5. The gel base material further comprises components of a microorganism culture medium, a reinforcing material for increasing the strength of the immobilized carrier, a filler for adjusting the specific gravity of the produced gel, a protective agent against freezing damage of microorganisms by freezing treatment, a hormone, and a nutritional supplement. May be included.

The gel base material constituting the gel-like fiber of the present invention is covered with an outer coating, has a network structure inside, and has an inner coating (in a dry state) having an average thickness in the range of 0.005 to 0.20 μm. This forms a mesh) and an outer coating having an average thickness in the range of 0.1 to 10 μm, and the average maximum diameter of the inner coating or the space formed by the outer coating and the inner coating is 0.1 to 10 μm in a dry state. Is within the range. These dimensions are determined by observing the cross section of the gel base in a dry state with an electron microscope. Here, the dry state means, for example, that the water in the gel is replaced with ethanol by sequentially immersing the hydrogel in an aqueous ethanol solution and ethanol, the ethanol-containing gel obtained is frozen in liquid nitrogen, and then dried under vacuum. This is the state achieved by doing so. The average maximum diameter of the space is determined by arbitrarily picking up 50 places in the space that has appeared in an electron micrograph of the cross section of the gel base material, measuring the maximum diameter in each space, and taking the arithmetic average of the numerical values.
The average thickness of the internal coating is determined by arbitrarily selecting one point of the internal coating forming the space for each of the above 50 spaces, measuring the thickness of the film at that portion, and arithmetically calculating the numerical value. Determined by taking the average. The average thickness of the outer coating is determined by taking 50 arbitrary locations of the outer coating, measuring the thickness of the outer coating at those positions, and taking the arithmetic average of the values.

If the average thickness of the inner coating is less than 0.005 μm, it becomes weak due to lack of elasticity as a gel molded body, and the space created by this coating is very small, so that the biocatalyst is included and immobilized as a space. Is not preferred. On the other hand, if it exceeds 0.20 μm, the film becomes thick and the skeleton of the gel structure becomes large, so that it lacks the permeability of the substrate and oxygen, and the growth of microorganisms and the activity as a biocatalyst are not preferable.

If the average maximum diameter of the space formed by the inner film or the inner film and the outer film is less than 0.1 μm, the permeability of the substrate and oxygen to the inside of the gel base material is impaired, and the living space for microorganisms is not preferable because it is too small. . On the other hand, if the thickness exceeds 10 μm, the space is too large, which impairs the mechanical strength of the gel and results in low gel strength, which is not preferable. In addition, if the space has the dimensions specified in the present invention, the space containing the microorganisms can contain 8 to 15 times the amount of water, thereby imparting affinity to the microorganisms.

When the average thickness of the outer coating is less than 0.1 μm, the mechanical performance of the gel is inferior in the strength and elasticity of the gel, and the abrasion is severe due to the collision and friction between the gel fibers in the reaction layer and the inner wall of the packed layer, and the durability is long-term. Is impaired. Further, the biocatalyst in the gel wrapped at a high concentration may leak to the external environment, which is not preferable. On the other hand, when covered with an outer coating exceeding 10 μm, the permeability of the substrate and oxygen deteriorates extremely, so that the microorganisms gather on the surface portion of the gel, and the substrate and oxygen do not pass through to the inside of the gel, which is not preferable as a biocatalyst. .

The biocatalyst entrapped and immobilized inside the gel substrate is not particularly limited, such as microorganisms, enzymes, animal and plant cells. The microorganism may be any of bacteria, actinomycetes, molds, yeasts, and the like, and may be obtained by pure culture, obtained by mixed culture, or activated sludge. As the microorganism, for example, Mucor (Muccor)
Genus, Fusarium genus, Cladotricus (Cl
adothrix), Sphaerotilus, Zoogloea, Leptomitus
Genus, Aspergillus, Rhizopus (Rhi
zopus), Pseudomonas, Acetobacter, Streptomyces (Str)
genus eptomyces, genus Escherichia, genus Saccharomyces,
and microorganisms belonging to genera such as the genera dida), and examples thereof include sulfur bacteria, methane bacteria, butyric bacteria, lactic acid bacteria, Bacillus subtilis, deformed bacteria, deficient bacteria, nitric acid bacteria, and nitrite bacteria. For the purpose of wastewater treatment, it is desirable to immobilize bacteria that produce proteases, carbohydrate degradation enzymes, and lipolytic enzymes. As an enzyme, regardless of its origin,
Those derived from animals and those derived from microorganisms can be arbitrarily selected. Representative examples of enzymes include lactate dehydrogenase (1.1.2.3) and lactate oxidase (1.1.
3.2), glucose oxidase (1.1.3.4), formate dehydrogenase (1.2.1.2), aldehyde dehydrogenase (1.2.1.3), aldehyde oxidase (1.2.
3.1), xanthine oxidase (1.2.3.2), pyruvate oxidase (1.2.3.3), pyruvate reductase (1.2.4.1), cortisone-α-reductase (1.3.1.
4), acyl-CoA-dehydrogenase (13.99.3), 3-
Ketosteroid ^{１ 1} -dehydrogenase (1.3.99.4),
3-ketosteroid ^{４ 4} -dehydrogenase (1.3.99.
5), L-alanine dehydrogenase (1.4.1.1), L-alanine dehydrogenase
Glutamate dehydrogenase (1.4.1.3), L-amino acid oxidase (1.4.3.2), D-amino acid oxidase (1.4.3.3), pyridoxal phosphate oxidase (1.4.3.5), catalase (1.11.1.6), catechol methyltransferase (2.1.1.6), carnitine acetyltransferase (2.3.1.7), acetyl-CoA acetyltransferase (2.3.1.9), asperate aminotransferase (2.6.1.1), alanine aminotransferase (2.6.1.2) ), Pyridoxamine pyruvate transferase (2.6.1), hexokinase (2.7.11), glucokinase (2.7.1.2), fructokinase (2.7.1.4), phosphoglucokinase (2.7.1.1)
0), phosphofructokinase (2.7.1.11), pyruvate kinase (2.7.1.40), carboxyesterase (3.
1.1.1), arylesterase (3.1.1.2), lipase (3.1.1.3), phospholipase A (3.1.1.4), acetylesterase (3.1.1.6), cholesterol esterase (3.1.1.13), glucoamylase (3.2.1.3) ), Cellulase (3.2.1.4), inulase (3.2.1.7), α-glucosidase (3.2.1.20), β-glucosidase (3.2.1.
21), α-galactosidase (3.2.1.22), β-galactosidase (3.2.1.23), invertase (3.2.1.2
6), pepsin (3.4.4.1), trypsin (3.4.4.4),
Chymotrypsin A (3.4.4.5), cathepsin A (3.4),
Papain (3.4.4.10), thrombin (3.4.4.13), amidase (3.5.1.4), urease (3.5.1.5), penicillin acidase (3.5.1.11), aminoacylase (3.5.1.
14), adenine deaminase (3.5.4.2), ATPase (3.6.1.3), pyruvate decarboxylase (4.1.
1.1), oxalate decarboxylase (4.1.1.2),
Tryptophan decarboxylase (4.1.1.27), aldolase (4.1.2.13), malate sucidase (4.1.3.
2), tryptophan synthase (4.2.1.20), asperase (4.3.1.1), lysine racemase (5.1.1.5),
Glucose-6-phosphate isomerase (5.3.1.9), steroid △ -isomerase (5.3.3.1), maxinyl-CoA
Synthetase (6.2.1.5) [(Note) Numbers in Kakko represent enzyme numbers. And the like. Also,
Examples of animal and plant cells include meristem cells, calli, and embryos.

The properties of the gel fibers of the present invention are generally as follows. The water content of the gel (proportion of water in the total amount of gel) is 70 ~
It is very high at 90% by weight. The amount of water to PVA is 8 to 15 times. Regarding the permeability of the substrate, the gel fiber of the present invention was immersed in an aqueous solution in which a constant concentration of the substrate was dissolved, the solvent was sampled at regular intervals, and the concentration of the substrate was determined by gas chromatography to reach equilibrium. The concentration of the substrate in the gel at the time point was determined. The partition coefficient (substrate concentration in gel / substrate concentration) was determined from this value. Ethanol
0.97, methanol 0.98, sucrose 0.98, glucose 0.98, synthetic sewage 0.89, very high and close to 1. The tensile strength of the gel-like fiber of the present invention is 3 kg / cm ² or more, and the elongation at that time is 100 to 400%, and exhibits rubber-like elasticity (measurement is performed using Shimadzu Autograph IM-100. Went).

On the other hand, the abrasion resistance in water was measured using a bundle of gel-like fibers at a filling rate of 10% and charged into an aeration tank by the standard activated sludge method, aerated in upward water, and the weight change after each day was examined. (Water temperature was 10-20 ° C). The weight change during the first 30 days of the test showed a decrease of about 10-18% of the total weight,
After that, the reduction rate after 360 days was as small as 1 to 2%, and no fiber cutting was observed.

The cross-sectional shape of the gel-like fiber of the present invention is not particularly limited, and is circular, triangular, square, pentagonal, hexagonal, star-shaped, flat,
Any shape such as a rectangle can be adopted.

The biocatalyst-immobilized PVA gel fiber of the present invention has a high affinity for a biocatalyst, has strength and durability applicable to various types of reaction tanks, and has excellent water resistance and chemical resistance. And has desirable characteristics as an immobilized biocatalyst.
As described below, this gel-like fiber can be produced by a simple operation of freezing treatment and without using any chemical solution harmful to microorganisms.

The biocatalyst-immobilized PVA gel fiber of the present invention can be used in a bioreactor for wastewater treatment, production of alcohol and acetic acid for industrial production, and the like. Agricultural uses include use as artificial seeds by encapsulating seeds, encapsulating cells or callus, and immobilizing useful bacteria. In addition, as an industrial material, it can be used for filters, wallpaper, etc. in which bacteria having odor eliminating performance are immobilized. For medical use, it can be processed into cotton, spun yarn, non-woven fabric or the like and used as a local cold insulator. Furthermore, it can be used for drainage treatment and greening by being installed in the channel as an artificial algae. It can also be used as an egg-laying material and as a culture material.

Hereinafter, the method for producing the biocatalyst-immobilized PVA gel fiber of the present invention will be described in detail.

As described above, the biocatalyst-immobilized PVA gel fiber of the present invention discharges a mixed aqueous solution containing a water-soluble polymer polysaccharide capable of gelling by contact with a biocatalyst, polyvinyl alcohol and a cation. The mixed aqueous solution is formed into a fibrous form by contact with an aqueous solution containing a compound containing a cation, and then the resulting fibrous formed product is treated at -5 ° C or lower by freezing and subsequent thawing. At least once. As the water-soluble high molecular polysaccharide, various ones can be used as described above, but it is preferable to use sodium alginate or κ-carrageenan. When sodium alginate is used, as a compound containing a cation capable of gelling it, calcium chloride (hereinafter, CaCl 2)
₂ ).
When κ-carrageenan is used, it is preferable to use potassium sulfate or aluminum sulfate together with sodium sulfate as the compound containing a cation capable of gelling it. The concentration of PVA in the PVA mixed aqueous solution can be from 3 to 40% by weight from the range of the PVA gel forming ability. As the PVA concentration increases, a stronger gel is generated, but if the required gel strength is obtained, , PV
The lower the A concentration, the higher the affinity of the gel substrate for the biocatalyst, the higher the water content, and the better the permeability of the substrate and oxygen. Types and concentrations of additives other than PVA, P
Depending on the temperature of the VA mixed aqueous solution, the diameter of the discharge nozzle, etc.,
It is necessary to select an appropriate concentration.
When the mixed aqueous solution is discharged into the aqueous solution of the cation-containing compound, if the PVA concentration is 3 to 10% by weight, coagulation is easy, and practically sufficient gel strength is obtained.

The concentration of the water-soluble polymer polysaccharide added to the aqueous PVA mixed solution is 0.2 to 4% by weight, more preferably 0.5 to 2% by weight based on water.
Is good. If the content is less than 0.2 wt%, the surface solidification of the PVA mixed aqueous solution becomes insufficient, and the inner coating and the outer coating are thin, so that only a gel having insufficient durability and strength is obtained, which is not preferable. Conversely, the concentration of the water-soluble polysaccharide is 4w
If it is larger than t%, a hard fibrous molded product is obtained, but not only the solution viscosity is increased, but also the outer coating of the gel becomes thicker, and the permeability of the substrate and the enzyme is hindered. It is not preferable because the microbial properties become insufficient and the fiber strength is low and the fiber becomes brittle. The biocatalyst of the present invention for encapsulating and immobilizing the gel fibers is mixed in a PVA mixed aqueous solution. In addition, the PVA mixed aqueous solution contains a biocatalyst medium, a reinforcing material for increasing the strength of the immobilized carrier, a filler for adjusting the specific gravity of the produced gel, and a biomaterial obtained by freezing treatment within a range that does not inhibit gelation of PVA. Protective agents against freeze damage of the catalyst, hormones, nutrients and the like may be added.

The surface of the PVA mixed aqueous solution is solidified by discharging the above PVA mixed aqueous solution from a nozzle having an arbitrary shape and bringing the mixed aqueous solution into contact with an aqueous solution of a cation-containing compound, thereby obtaining a fibrous molded product. At this time, the PVA mixed aqueous solution
For example, it is sent from a raw material tank kept at a constant temperature with hot water to a nozzle having a hole diameter of 0.1 to 5 mm through a metering pump. The aqueous solution of the cation-containing compound in the coagulation bath is CaCl 2 when the water-soluble polysaccharide is sodium alginate.
₂ aqueous solution is preferred, the concentration of CaCl ₂ aqueous solution is 0.05-1.0 m
ol / is preferable, and usually 0.1 to 0.5 mol / is preferable from the viewpoint of the PVA concentration and the sodium alginate concentration, or the hardness of the molded product of the PVA mixed aqueous solution. When the water-soluble polymer polysaccharide is κ-carrageenan, the aqueous solution of the cation-containing compound is preferably a mixed aqueous solution of sodium sulfate 0.1 to 2 mol / and potassium sulfate 0.05 to 1.0 mol /. The PVA mixed aqueous solution discharged from the nozzle hole is immersed in such a coagulation liquid and wound up while moving upward or laterally while loosely coagulating. If the hole diameter of the nozzle to be discharged exceeds 5 mm, it is not preferable because it takes time until internal solidification becomes uniform, and the fibrous material becomes thick, which causes a problem in handleability. On the other hand, when the nozzle hole diameter is as small as less than 0.05 mm, the coagulability is good, but the fiber diameter is too thin, which causes a problem in handleability, which is not preferable. Preferably, a nozzle having a hole diameter of 0.1 to 2 mm is good. The diameter of the fibers obtained is usually between 0.05 and 7 mm. In the coagulation bath, it is desirable to add a concentration correction in order to maintain a constant salt concentration, and it is also desirable to perform slow circulation and liquid circulation in order to obtain uniform coagulation. Further, it is desirable to perform temperature control in order to keep the coagulation bath temperature constant.

The gel of the fibrous PVA mixed aqueous solution is separated from the coagulation bath aqueous solution and frozen as it is or after washing with water. The freezing temperature may be -5 ° C or lower, but -20 ° C or lower is more preferable to obtain a stronger PVA gel. The freeze-holding time is 2 hours or more, preferably 10 hours or more. By the freezing treatment, the fiber molded product of the PVA mixed aqueous solution gels. This is left in a temperature range that does not adversely affect the biocatalyst and is thawed to obtain a fibrous PVA gel.

The fibrous PVA gel can be obtained by a single freeze-thaw treatment, but the strength may not reach the required strength depending on the composition of the PVA mixed aqueous solution and the freezing conditions. More preferably, by repeating freeze-thaw at least three times, a fibrous gel having sufficiently high strength can be obtained.

E. Examples Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited to these Examples.

Example 1 PVA manufactured by Kuraray Co., Ltd. (average polymerization degree 1740, saponification degree 99.
85 mol%) with 40 ° C warm water for about 1 hr, PVA concentration 8wt%
Then, water was added to PVA to make the total amount 40 g, and the pH was adjusted to 6. This is treated in an autoclave at 120 ° C for 30 minutes, and PVA
Was dissolved and then allowed to cool to room temperature. After adding 0.4 g of sodium alginate to this aqueous PVA solution and mixing, 0.5 g-wet cell of yeast (Saccharomyces cerevisiae) was further added.
4 ml of sterilized water containing s / ml was added and stirred sufficiently.

The mixed solution is fed at a rate of 0.5 ml / min by a roller pump using one vinyl tube having an inner diameter of 2 mmφ, and a 0.5 mol / aqueous calcium chloride solution is introduced through a 0.8 mm inner diameter injection needle attached to the end of the vinyl tube. It was discharged into a coagulation bath of 1 m. The take-up speed at this time was 0.8 m / min, and the film was wound up.

These fibrous PVA mixed liquid molded products were separated from the aqueous CaCl ₂ solution, washed lightly with sterilized water, and then frozen in a freezer at −27 ° C. ± 3 ° C. After freezing for 20 hours and thawing at room temperature, an opaque yellow-white flexible fibrous gel was obtained. The gel was not sticky. Further, in order to increase the strength of the gel, the above freeze-thaw treatment was repeated twice.

Fibrous PVA with immobilized yeast obtained in this way
The average diameter of the gel was 0.7 mm (by cross-sectional optical microscopy). Table 1 shows the water content, distribution coefficient, underwater wear strength, gel strength, inner and outer coating average thickness, and space average maximum diameter of this PVA gel fiber.

Example 2 The same PVA used in Example 1 was subjected to the same treatment as in Example 1 to obtain a 16% aqueous solution. to this,
Κ-carrageenan and MLSS 20000 prepared in a 3% aqueous solution
Activated sludge collected from the Kuraray Yamaoka Plant (1-2-1, Kaigandori, Okayama City, Okayama Prefecture) adjusted to mg / mg was added to obtain a 7% PVA mixed aqueous solution. This mixed aqueous solution was extruded into a mixed aqueous solution (coagulating liquid) of sodium sulfate having a concentration of 0.5 mol / and 0.1 mol / potassium sulfate in the same manner as in Example 1. The take-off speed at this time was 1 m / min. Otherwise, the same treatment as in Example 1 was performed to obtain a fiber having an average diameter of 0.8 mm. The performance obtained is shown in Table 1.

Comparative Example 1 The same PVA as used in Example 1 was subjected to the same treatment as in Example 1 to obtain a 20% PVA aqueous solution, and adjusted to a 3% aqueous solution, the sodium alginate used in Example 1
20 parts and 60 parts of water were added, and the same amount of the same yeast as used in Example 1 was further added thereto, followed by coagulation in a 2 mol / calcium chloride aqueous solution. Except for the above, the same treatment as in Example 1 was carried out to obtain a PVA gel-like fiber having a diameter of 0.8 mm. The physical properties of the obtained gel are shown in Table 1.

Comparative Example 2 The same PVA used in Example 1 was subjected to the same treatment as in Example 1 to obtain a 10% PVA aqueous solution. Except for the above, a microorganism mixed aqueous solution was obtained in the same manner as in Example 1.
This aqueous solution was discharged into a saturated boric acid aqueous solution in the same manner as in Example 1. The PVA gel was too soft, but a gel-like fibrous material could not be obtained.

Reference Example 1 16 g of the PVA gel fiber obtained in Example 1 was packed in a column kept at 30 ° C., and 100 g of a reaction solution for producing ethyl alcohol (glucose 10 wt%, MgSO ₄ .7H ₂ O 60 ppm, pH 6) was added.
The liquid was circulated with a rotary pump. Similarly, another column was filled with 16 g of PVA gel-like fiber, and 100 g of a liquid medium (peptone 1%, yeast extract 1%, glucose 1%, sodium chloride 0.5%, pH 6) was added at 30 ° C. for culture and growth. After shaking for 18 hours, 100 g of ethanol production reaction solution with the same composition as above
And circulated. The concentration of the produced ethanol was measured by gas chromatography. For comparison, the same amount of yeast as the yeast contained in the gel fiber packed in the column was packed, and an ethanol production reaction was attempted in the same manner. As a result, the ethanol concentration (%) was as shown in Table 2.

The gel fiber obtained in Example 1 showed no change even after 7 days.

It was also found that the ethanol production was the same as the control.

Reference Example 2 The PVA gel fibers obtained in Example 2 were bundled at one end so as to be 0.2, and attached around an air diffuser in the second aeration tank. The PVA gel-like fibers swayed upward like algae due to the upward flow of air. As artificial sewage in the aeration tank, peptone 20 g /, meat extract 16 g /, urea 4 g /, NaCl
1.2 g /, KCl 0.56 g /, MgSO ₄ 0.4 g /, Na ₂ HPO ₄ 4 g /
, Was prepared by diluting BOD24000mg / things to 80-fold with CaCl ₂ 0.56 g /. The treatment status was observed while aerating. The average value of the results is as shown in Table 3.

F. Effects of the Invention According to the present invention, as is apparent from the above-described examples,
A biocatalyst-immobilized PVA gel fiber having a high water content and excellent abrasion resistance and a simple method for producing the same are provided. The biocatalyst-immobilized PVA gel fiber of the present invention can efficiently exhibit the activity of the immobilized biocatalyst over a long period of time.

Continued on the front page (72) Inventor Hiroaki Fujii 1-2-1, Kaigandori, Okayama-shi, Okayama Pref.

Claims (2)

(57) [Claims] (1) comprising (a) an inner film and an outer film made of polyvinyl alcohol and a water-soluble polymer polysaccharide,
The average thickness of the inner coating in the dry state is 0.005 to 0.20μ
m and the average thickness of the outer coating is 0.1 to 10 μm
(B) a gel base material having an average maximum diameter of a space formed by the inner coating or the inner coating and the outer coating in the range of 0.1 to 10 μm; A biocatalyst-immobilized polyvinyl alcohol gel fiber, comprising an immobilized biocatalyst and (c) water. 2. A mixed aqueous solution containing a water-soluble polymer polysaccharide capable of gelling by contact with a biocatalyst, polyvinyl alcohol and a cation is discharged to come into contact with an aqueous solution containing a cation-containing compound. The mixed aqueous solution is formed into a fibrous form by causing the mixture, and the resulting fibrous formed body is subjected to at least one treatment comprising freezing at -5 ° C or lower and subsequent thawing. 2. The method for producing a biocatalyst-immobilized polyvinyl alcohol gel fiber according to 1.