JPH06494A - Molded form for bioreactor - Google Patents

Abstract

(57) [Summary] [Purpose] A bioreactor molded article capable of uniformly and sufficiently supplying oxygen to a fibrous gel or fibers, and using the molded article to conduct a biocatalytic reaction in a reactor. Provided is a molded body for bioreactor which can be carried out on an industrial scale. [Structure] (1) A fibrous gel or fibers is fixed in a forested manner in the vicinity of the ventilation holes of a strip base having ventilation holes having a corrugated cross section or a strip base having ventilation holes having a plurality of pipe cross sections. Molded article for bioreactor. (2) A fibrous gel or fibers are juxtaposed in the vicinity of the ventilation holes of a sheet-shaped strip base having a corrugated cross-section vent or a sheet strip base having a plurality of pipe cross-sections. A molded article for bioreactor having a structure in which the sheet-shaped base is rolled up and fixed in a sheet shape.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fibrous gel or a fiber-holding and immobilizing structure in which biocatalysts such as microorganisms and enzymes used in wastewater treatment and fermentation reactions are entrapped and immobilized. More specifically, when a large number of fibrous gels or fibers are used at a practical level, it is possible to supply oxygen (air) uniformly and sufficiently to each of the extremely large number of fibrous gels or fibers. To a molded article for a bioreactor.

[0002]

2. Description of the Related Art Conventionally, a granular gel has been known as a biocatalyst-immobilized molded article, and it is also known to use polyvinyl alcohol (hereinafter abbreviated as PVA) as a gel material. Further, it is also known to form a PVA gel into a fibrous shape (for example, JP-A-2-112407 and JP-A-2-21875). However, when these gels are granular gels, the surface area of the gels is so small that the amount of immobilized biocatalyst cannot be increased, and as a result, highly active and highly efficient treatments cannot be performed. . In order to solve this problem, it is conceivable to reduce the particle size of the granular gel and increase the packing density thereof, but if the particle size of the granular gel is reduced, a drift of the treatment liquid may occur, Trouble such as the gel flowing out of the system occurs, or the efficiency of the immobilized biocatalyst is low because oxygen cannot be sufficiently supplied to the entire gel filled, and in some cases it is immobilized. There were problems such as the death of the biocatalyst.

As one means for solving this problem, it is conceivable to increase the biocatalyst fixing area by making the gel into a fibrous shape, but in order to use the fibrous gel on an industrial scale, , A very large number of fibrous gels must be used. However, in order to sufficiently express the activity of the entrapped and immobilized biocatalyst, a very large number of fibrous gels are effectively installed in the bioreactor, and oxygen is uniformly and sufficiently supplied to these fibrous gels. A molded article for a bioreactor that can be used was not known.

In the above-mentioned Japanese Patent Laid-Open No. 2-112407, the woven fabric, knitted fabric,
A cloth shape and the like are described. However, the method of simply preparing the fibrous gel into a cloth-like body such as a woven or knitted fabric is difficult to fix and install a large number of cloth-like bodies in the bioreactor,
Even if fixedly installed, it is difficult to supply oxygen uniformly, and the energy load for supplying oxygen is large. Further, when a large number of cloth-like bodies are placed in the bioreactor in a non-fixed manner, the cloth-like bodies become unevenly distributed, oxygen cannot be uniformly supplied, and it is difficult to obtain high treatment efficiency.

Further, in the above-mentioned Japanese Patent Application Laid-Open No. 2-212875, there is an experiment in which one end of a fibrous gel is bundled and attached around a diffuser pipe in a 2-liter aeration tank, and an artificial sewage is purified by using this. It is disclosed. However, although the method of bundling one end of the fibrous gel can be carried out on a laboratory scale, it cannot be said that it can be carried out on an industrial scale. The reason is that in order to increase the activity, a very large number of fibrous gels or fibers to which a biocatalyst is fixed must be used, and it is difficult to supply sufficient oxygen to each of these fibrous gels or fibers, and high This is because it is impossible to maintain the active state for a long time on an industrial scale.

[0006]

DISCLOSURE OF THE INVENTION An object of the present invention is to provide a bioreactor capable of efficiently carrying out a biocatalytic reaction on an industrial scale by using an extremely large number of fibrous gels or fibers in the bioreactor. To provide a molded product for use.

[0007]

As a result of intensive studies to solve the above problems, as a result, a strip-shaped base having a ventilation hole having a corrugated cross section or a strip-shaped base having a ventilation hole having a plurality of pipe-shaped cross sections is formed. The present invention has been completed by finding a bioreactor molded product in which fibrous gel or fibers are fixed in a forest shape near the ventilation holes.

The present invention will be described in detail below. The present invention relates to a fibrous gel on which a biocatalyst for immobilizing a biocatalyst is fixed in a bioreactor, or a molded article on which a fiber is immobilized, and the fibrous gel or fiber includes a biocatalyst. It may be fixed or not entrapped, but encapsulation of biocatalyst is preferred. The fibrous gel or fibers may be organic fibers or inorganic fibers. In the following, the case of a fibrous gel is described in order to avoid language complexity.

Examples of the biocatalyst that is entrapped and immobilized inside the gel substrate include microorganisms, enzymes, animal and plant cells, but is not particularly limited. The microorganism may be any of bacteria, actinomycetes, fungi, yeast, etc., and may be one obtained by pure culture, one obtained by mixed culture, or activated sludge fungus. Examples of microorganisms include
Fusarium (Fusar)
ium, Cladothrix
x) genus, Sphaerotilus
Genus, Zoogloea genus, Leptomitus genus, Aspergillus (Asp)
ergillus), Rhizopus
Genus, Pseudomonas genus, Acetobacter genus, Streptomyces genus, Escherichia genus, Saccharomyces genus, Candida (C)
and microorganisms belonging to the genus such as the genus
Sulfur bacteria, methane bacteria, butyric acid bacteria, lactic acid bacteria, Bacillus subtilis, deformed bacteria, defective bacteria, nitric acid bacteria, nitrite bacteria and the like are also exemplified. For the purpose of wastewater treatment, it is desirable to immobilize bacteria that produce proteolytic enzymes, carbohydrate degrading enzymes, and lipolytic enzymes. As the enzyme, regardless of its origin, animal-derived ones, microorganism-derived ones and the like can be arbitrarily selected. As typical examples of the enzyme, lactate dehydrogenase (1.1.2.3), lactate oxidase (1.1.3.2), glucose oxidase (1.1.3.4), formate 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 Δ1-dehydrogenase (1.3.9.4),
3-ketosteroid Δ4-dehydrogenase (1.3.
99.5), L-alanine dehydrogenase (1.4.
1.1), L-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 acetyl transferase (2.3.1.9), aspertate amino transferase (2.6.1.1), alanine amino transferase (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 (2.7.1.10), phosphofructokinase (2.7.1.11), pyruvate kinase (2.7). .1.40), carboxyesterase (3.
1.1.1), aryl esterase (3.1.1.
2), lipase (3.1.1.3), phospholipase A
(3.1.1.4), acetyl esterase (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.
26), bepsin (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), A. T. P. ASE (3.
6.1.3), pyruvate decarboxylase (4.
1.1.1), oxalate decarboxylase (4.
1.1.2), tryptophan decarboxylase (4.1.1.27), aldolase (4.1.2.1)
3), malate sutase (4.1.3.2), tryptophansidase (4.2.1.20), aspertase (4.3.1.1), lysine racemase (5.1.
1.5), glucose-6-phosphate isomerase (5.
3.1.9), steroid Δ-isomerase (5.3.
3.1), maxinyl CoA synthetase (6.2.
1.5) [(Note) Numbers in parentheses represent enzyme numbers. ] Etc. can be mentioned. In addition, examples of the animal and plant cells include growing point cells, callus, embryos and the like.

The above-mentioned fibrous gel in which the biocatalyst is entrapped and fixed, for example, a PVA-based fibrous gel can be obtained, for example, by the production method of the above-mentioned patent publication, but is not limited thereto. Among the above-mentioned patent publications, the production method described in Japanese Patent Application Laid-Open No. 2-211875 is more preferable in that a gel-like fiber optimal for use in a bioreactor can be obtained in various respects. That is, a mixed aqueous solution obtained by adding PVA and a water-soluble polymer polysaccharide capable of gelling upon contact with cations and a biocatalyst is added from a nozzle to a cation-containing compound to be a coagulating liquid. It is preferable that the fibrous substance is formed into a fibrous substance by discharging it into an aqueous solution, and the obtained fibrous substance is subjected to at least one treatment of freezing at −5 ° C. or lower and subsequent thawing. As PVA, the average degree of polymerization is preferably 1000 or more, more preferably 1700 or more, still more preferably 2500 or more. PV
The saponification degree of A is preferably 98.5 mol% or more, and 99.
Complete saponification of 85 mol% or more is more preferable. In addition, various modified PVA can be used within the range that does not impair the object of the present invention. Further, PVA having high syndiotacticity can also be used.

Examples of the water-soluble polymer polysaccharide having the ability to gel upon contact with cations include alkali metal salts of alginic acid, carrageenan, mannan, chitosan and the like. Among them, sodium alginate and k-carrageenan. Is particularly preferable. The mixing ratio (weight ratio) of PVA and water-soluble polymer polysaccharide is 35:65 to 95 :.
A range of 5 is preferred. Calcium chloride (CaCl ↓ 2) is preferable as a compound containing a cation that serves as a coagulating liquid. The concentration of the aqueous coagulating liquid is 0.05 to 1.0 mol /
1 and more preferably 0.1 to 0.5 mol / l. When k-carrageenan is used, it is preferable to use 0.05 to 1.0 mol / l of potassium sulfate or aluminum sulfate together with 0.1 to 2 mol / l of sodium sulfate.

The PVA concentration in the PVA mixed aqueous solution is
From the range of PVA gel forming ability, 3 to 40% by weight is possible. The higher the PVA concentration, the stronger the gel is formed, but if the required gel strength is obtained, the lower the PVA concentration, the higher the affinity of the gel base material for the biocatalyst,
Since the water content is high and the permeability of the substrate and oxygen tends to be good, it is necessary to select the PVA concentration depending on the purpose.

The concentration of the water-soluble polymeric polysaccharide added to the PVA mixed aqueous solution is preferably 0.2 to 4% by weight, more preferably 0.5 to 2% by weight, based on water. If the concentration of the water-soluble polymer polysaccharide is less than 0.2% by weight, the durability and strength of the gel will be insufficient, and if it exceeds 4% by weight, a hard gel will be obtained, but the permeability of the substrate and oxygen will be impaired. Therefore, the activity of the biocatalyst becomes insufficient, the fiber strength of the gel is low, and the gel becomes brittle, which is not preferable.

The nozzle has a hole diameter of 0.1 to 5 mm, preferably 0.1 to 2 mm.

The diameter of the fibrous gel is usually 0.05 to 7 m.
m. This fibrous gel is separated from the coagulation bath aqueous solution and then either as it is or after being washed with water and then frozen at -5 ° C or lower. Freezing below -20 ° C is required to obtain stronger PVA gels. Freezing retention time is 2 hours or more, preferably 10
More than time is good. The frozen gelled product is then left in a temperature range that does not adversely affect the biocatalyst and thawed to obtain fibrous PVA. When the gel does not reach the required strength, it is preferable to repeat the freeze-thaw treatment twice or more.

The above-mentioned method is a method for improving the strength of gel using gel fibers alone. However, the fiber structure has ordinary fibers having excellent strength in the core as a reinforcing material, and the gel covers the core. By using a core-sheath structure as a sheath, the strength of the gel-like fiber can be remarkably improved and the gel-like fiber can be prevented from being cut. An example of the method for producing the core-sheath structure gel-like fiber is obtained by discharging the PVA mixed stock solution, which is to be the above-mentioned gel, together with ordinary fibers having excellent strength from the nozzle into the coagulation bath. The fiber used as the core material is not particularly limited as long as it has a strength capable of withstanding use in a reaction tank. For example, natural fibers such as cotton, hemp, wool and silk, recycled fibers such as rayon, semi-synthetic fibers such as acetate, polyamide-based, polyvinyl alcohol-based, polyvinylidene chloride-based,
Polyvinyl chloride-based, polyester-based, polyacrylonitrile-based, polyethylene-based, polypropylene-based, polyurethane-based, polyalkylene paraoxybenzoate-based, phenol-based, polyfluoroethylene-based synthetic fibers, etc.
Inorganic fibers such as glass fiber and carbon fiber can be mentioned,
Considering durability in the bioreactor, synthetic fibers that are not decomposed by a biocatalyst are preferable. Further, as a form of the fiber used as the core agent, a form excellent in sticking property of the gel serving as the sheath portion, that is, a processed fiber such as fluffy spun yarn or taslan is preferable.

In the present invention, the biocatalyst-immobilized PVA-based fibrous gel thus obtained is used to obtain oxygen, which is indispensable for the survival of the immobilized biocatalyst, in the form of minute bubbles while maintaining high density. The basic idea is to make it pass evenly in the vicinity of the gel. 1 (a),
As shown in (b), (c), and (d), in the vicinity of the ventilation holes of the strip-shaped base 2 having ventilation holes having a corrugated cross section or the strip-shaped base 2 having ventilation holes having a plurality of pipe-shaped cross sections. Has a structure in which an extremely large number of fibrous gels 1 are joined together at a high density with appropriate equal intervals, and oxygen (air) fed from below passes through the vent holes of the base to join them. Around the formed fibrous gel, it can be supplied from below to above. The cross-sectional area of such a vent is preferably 0.2 to 80 mm ↑ 2, more preferably 3 to 30 mm ↑ 2.

FIG. 2A shows a rectangular base 2 having a corrugated cross-section shown in FIG. It is a molded product 3 obtained by winding up the sheet-shaped base obtained by joining. 2B shows that the strip-shaped base 2 having the ventilation holes having the corrugated cross section shown in FIG. 1A is joined in parallel in the vicinity of the ventilation holes at appropriate intervals. It is a molded product 3 obtained by stacking the obtained sheet bases. As can be understood by the above manufacturing method,
The distance between the fibrous gels is determined by the distance between the fibrous gels when the fibrous gels are attached to the sheet and the thickness of the strip-shaped sheet. Therefore, the distance between the fibrous gels can be set closely within the range in which the aerated air can rise well in the holes of the base, which enables a high-density implant structure. It should be noted that the fibrous gel can be joined to the strip-shaped base by such a degree that the position of the fibrous gel does not shift during roll-up molding of the sheet-shaped base. Temporary fixing is sufficient.

The strip-shaped base can hold and fix the end of the fibrous gel, can supply aerated air evenly to the vicinity of the held and fixed fibrous gel, and can supply the aerated air with a pressure loss as small as possible. It is necessary to be able to. From this point of view, the length of the short sides of the strip-shaped base may be appropriately adjusted, and the raw material of the strip-shaped base is preferably water-resistant, hard, and not deteriorated by the treated water.

The installation of the molded article 3 of the present invention in the bioreactor 4 is typically carried out by installing it in the lower part of the bioreactor as shown in FIG. 3, and feeding aerated air from below through the filter 6. Is adopted.

Due to its structure, the molded product of the present invention has a fiber bundle part of the fibrous gel and a terminal fixing part of the fibrous gel,
A cartridge-like structure in which it is wrapped with a cylindrical body 5 having a return hole can be used. This cartridge molded body 4
Since it is easy to handle, it is recommended to have such a structure depending on the purpose of use.

Since the present invention is configured as described above, it has the following effects. That is, (1) using a fibrous gel or fibers, preferably using a fibrous gel on which a biocatalyst is immobilized, and further densifying the same, regardless of the densification Since oxygen, which is indispensable for biocatalyst, can be uniformly and sufficiently supplied to the gel or fiber, high-speed treatment of the bioreactor becomes possible. (2) Further, since the oxygen supply property and the catalytic activity are high, the biocatalytic reaction can be carried out extremely efficiently, and when it is used for treating wastewater, the sludge generation amount is reduced. (3) It can be made into a cartridge and is easy to handle.

[0023]

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. Example 1: PVA manufactured by Kuraray Co., Ltd. (average degree of polymerization: 400
0, saponification degree 99.85 mol%) was washed with warm water at 40 ° C. for about 1 hour, and then PVA concentration was adjusted to 10% by weight.
Water was added to VA to make the total amount 400 g, and the pH was adjusted to 6. This was treated in an autoclave at 120 ° C. for 30 minutes to dissolve PVA and then allowed to cool to room temperature. This PV
A 4% by weight aqueous solution of sodium alginate 200
Activated sludge (MLSS) obtained by adding g and mixing, and collecting by the wastewater treatment tank of the Kuraray Okayama Factory (1-2-1, Kaigandori, Okayama City, Okayama Prefecture) and subjecting to concentration
200,000 (80,000 mg / liter) was added and sufficiently stirred. This mixed liquid was discharged together with a polyester spun yarn (20th count) manufactured by Kuraray Co., Ltd. from an injection needle-shaped discharge port having an inner diameter of 1.2 mm. The discharge port was immersed in a 0.2 mol / l calcium chloride (CaCl ↓ 2) aqueous solution, and the discharge product was drawn at a speed of 5 m / min. Discharged product C
The residence time in the aCl ↓ 2 aqueous solution was set to 1 minute. The discharged material immediately covered the surface of the yarn and solidified by contact with the CaCl ↓ 2 aqueous solution. After lightly washing this with distilled water, -2
It was frozen in a 0 ° C. freezer for 24 hours and then thawed at room temperature. Further, this freezing and thawing operation was repeated twice. This gave an opaque brown flexible core-sheath fibrous gel. This fiber had an average diameter of 1.2 mm, a tensile strength of 101 kg / cm ↑ 2 and a water content of 94%. This fiber was immersed in an activated sludge aeration tank of Kuraray Okayama Factory for 10 days. Since the color of the core-sheath fibrous gel changed from light brown to dark brown, the growth of activated sludge was confirmed. Further, since the shape of the core-sheath fibrous gel did not change before and after the culture, it was found that the core-sheath fibrous gel also has excellent durability.

On the other hand, a sheet-shaped strip-shaped base having a vent having a corrugated cross-section for fixing the above-mentioned fibrous gel is 100 g / m ↑ 2 in unit weight of vinylon fiber having a single fiber fineness of 2 denier and a thickness of ↑ 2. A 0.6 mm paper was used, and a sheet-shaped strip base having a short side length of 30 mm was used.

As shown in FIG. 1 (a), the end portions of the fibrous gel are arranged on the sheet-shaped strip-shaped base in parallel so that the distance between them is about 2 mm, and the length is about 10 mm.
It was cut to a length of 00 mm and fixed with an adhesive. Next, the sheet-shaped strip-shaped base was wound up by winding a bandage from one end side thereof to form a molded body having a diameter of 5 cm shown in FIG.

The above-mentioned molded body was formed into an inner diameter of 60 mm and a height of 150.
The bioreactor having a cylindrical shape of 0 mm and made of transparent vinyl chloride was installed as shown in FIG. 3, the following artificial sewage was introduced, and the treatment situation was observed while blowing aeration air from below the reactor. <Artificial sewage> (The water used has the following composition and is BOD240
80 mg diluted with 80 mg / l) Peptone: 20 g / l Meat extract: 16 g / l Urea: 4 g / l NaCl: 1.2 g / l KCl: 0.56 g / l MgSO4: 0.4 g / l Na2HPO4: 4g / l CaCl2: 0.56g / l

The results are shown in Table 1 below. The molded article of the present invention, even though the bioreactor is densely packed with the fibrous gel, since the aerated air passes evenly in the vicinity of the individual gels, the activity of the activated sludge is Can be increased and maintained over the long term. Also, aeration energy may be small.

[0028]

[Table 1]

[Brief description of drawings]

FIG. 1 is an explanatory view illustrating an example of the molded product of the present invention.

FIG. 2 is an explanatory view illustrating an example of the molded product of the present invention.

FIG. 3 is a conceptual diagram of an example of a bioreactor in which the molded cartridge product of the present invention is installed.

[Explanation of Codes] 1 Fibrous gel 2 Sheet-shaped strip base 3 Bioreactor molding 4 Bioreactor 5 Cylindrical substance in bioreactor 6 Air filter

Claims (2)

[Claims] 1. A fibrous gel or fibers are fixed in a forest-like manner in the vicinity of the ventilation holes of a strip base having ventilation holes having a corrugated cross section or a strip base having ventilation holes having a plurality of pipe cross sections. Molded product for bioreactor. 2. A fibrous gel or a fiber in the vicinity of a vent hole of a sheet-shaped strip base having a vent having a corrugated cross section or a sheet strip base having a vent having a plurality of pipe cross sections. Fixed in parallel,
A molded article for a bioreactor having a structure obtained by rolling up the sheet-shaped base.