JPS63294783A - Immobilization of cell of microorganism - Google Patents

Abstract

PURPOSE:To form a microorganism immobilized carrier having high treating activity, by blending a cell of microorganism with a first material to hydrate and to gelatinize by after-treatment, adding a second material to be solubilized by physiological action of the cell of microorganism to give a mixture and gelatinizing. CONSTITUTION:A cell of microorganism is blended with a first material to hydrate and to gelatinize by after-treatment and mixed with a second material to be solubilized by physiological action of the cell of microorganism to form a mixture, which is gelatinized to form a microorganisms immobilized carrier. As another method, a small amount of a substance to be a substrate for the gelatinized cell of microorganism and at least part of the second material is decomposed so that the microorganism immobilized carrier can be formed. Protein, starch and lipid are suitable as the second material.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for immobilizing microbial cells, and particularly to a method for increasing the activity of microbial cells.

[Prior art and its problems]

Various microorganisms, which have been researched and developed only in limited industrial fields such as the pharmaceutical industry and the food industry, have recently attracted attention for their use in a wide range of fields, from the semiconductor industry to wastewater treatment systems.

Therefore, the problem is how to immobilize microorganisms, and various methods for immobilizing microorganisms have been proposed that take into consideration the required conditions such as the type of microorganisms and usage conditions.

For example, JP-A-57-141292, JP-A-59-
A method of immobilizing microorganisms in a gel whose main component is an organic polymer, as seen in the 37tan publication, or “
As shown in "Immobilized Enzyme" by Chibata, published by Tokyo Kagaku Doujin,
There are methods that utilize polymerization of acrylamide, methods that utilize carrageenan, and methods that utilize photopolymerization of polymers.

In addition, in order to improve its strength and stability, it is possible to combine two or more materials (Japanese Unexamined Patent Publication No. 153794/1982), or to mix substances such as minerals that are not decomposed and metabolized by living organisms with the above materials. Method of
141291>, and furthermore, as a method of increasing the surface area of the immobilization carrier that contributes to the reaction, a method of pouring a mixture of gel raw material and bacterial cells into a mold having protrusions (Japanese Unexamined Patent Application Publication No. 1983-1999)
159826>, a method of vacuum drying a frozen gel material in the gelling process in order to make the gel porous (Japanese Patent Application Laid-open No.
-180587) etc. have also been proposed.

In this method of immobilizing microorganisms with a water-containing gel, microorganisms can be retained at a high concentration by covering (enclosing) the microbial cells in the gel. The problem was that only a small portion of the immobilized microorganisms could be used.

In addition, methods to increase the surface area by using molds with protrusions or by freeze-drying are effective in effectively using immobilized microorganisms, but they are difficult to manufacture and increase costs. It is not suitable for mass production because it invites Especially drainage 51! There is a problem in that it is not suitable for cases where a large amount of carrier is required at low cost, such as L31.

The present invention was made in view of the above circumstances, and an object of the present invention is to provide a microorganism-immobilized carrier with high treatment activity without reducing gel strength.

[Means for solving problems]

Therefore, one aspect of the present invention is to add a second material that can be decomposed by the action of the microbial cells when mixing the microbial cells with a first material (hereinafter referred to as gelling material) that can be hydrogelized by post-treatment. A microorganism-immobilized carrier is formed by allowing the gel to form.

In addition, in another aspect of the present invention, when mixing the microbial body with the first material n (hereinafter referred to as gelling material) that can be turned into a water-containing gel by post-treatment, a second material that can be decomposed by the action of the microorganism body is added. A microorganism-immobilized carrier is formed by adding a material, gelling it, adding a small amount of a substance that becomes a substrate for microorganism cells, and causing at least a part of the second material to be decomposed by the action of the microorganism cells. ing.

[For production]

In the present invention, a second material that is dissolved by the action of microorganism cells is added in advance together with the gelling material, and when gelled, the second material is dissolved by the action of the microorganism cells and becomes pore-formed. This was developed by paying attention to the phenomenon of the formation of microorganisms, and the presence of numerous pores created by this decomposition makes it a microorganism-immobilized carrier with high substrate permeability.

In addition, if a small amount of a substance that is a substrate for microorganisms is added and cultured to promote gelation, dissolution can be promoted.
Furthermore, a microorganism-immobilized carrier with high substrate permeability can be obtained.

That is, the added second material is decomposed by microorganisms within the carrier or external microorganisms, and is eventually metabolized or diffused and dissolved into the gel.

As a result, the spaces in the gel where the second material existed become pores, and these pores are filled with the solvent. In this way, many pores are generated in the gel, improving mass transfer within the carrier and improving substrate permeability of immobilized microorganisms.
Most of the microorganisms in the carrier can be made active, and the processing activity of the microorganism-immobilized carrier is enhanced.

In this way, by providing a large number of microscopic pores inside the gel and filling the pores with water, the substrate permeability of the entire carrier can be significantly improved without changing the strength and substrate permeability coefficient of the gel matrix. A microorganism immobilization carrier is formed that is inexpensive and easy to produce by hanging from the ceiling.

There are no particular restrictions on the microorganisms to which this method can be applied, and it can be applied to both anaerobic and aerobic microorganisms, as long as the microorganisms are capable of dissolving and are resistant to dissolution, decomposition, or alteration in the gel. All you need is a substance that doesn't exist.

〔Example〕

Examples of the present invention will be described in detail below.

Experimental Example 1 First, 100 g of 20% polyvinyl alcohol (PVA) manufactured by Kuraray, which is commercially available under the name PVA-HC.
In contrast, the activated sludge is centrifuged at a rotation speed of 2500.
Activated sludge wet bacterial cells formed by concentrating for 10 minutes with RPI 20
Mix g.

Next, 10 g of toilet paper previously suspended in a small amount of water is further mixed into this mixture and stirred well.

Thereafter, this mixture was dropped into saturated boric acid water to gel the polyvinyl alcohol, thereby creating a spherical microorganism-immobilized carrier with a diameter of 6M.

The microorganism immobilization carrier prepared in this way was divided into 5 equal parts.
00- container and cultured for 20 days. As the culture solution, artificial sewage prepared from yeast extract, meat extract, hepton, etc. was used, and the microorganism-immobilized carrier was placed in this artificial sewage and cultured while blowing air.

After culturing in this way, total organic carbon (TOC>1
The carrier after culture was added to 100rd of 20ppm artificial sewage.
The results of measuring TOC after 0% filling and processing for 2 hours while supplying air were 181) I) 11, as shown in Table 1 a2 below.
The C removal rate was 85%, showing an extremely good result.

In addition, as an additive material, instead of toilet paper,
If the same amount of flour is added and everything else is the same as above, or if nothing is added at all, follow al in Table 1.
, the TOC removal rates are 87% and 75%, respectively, as shown in a3.
%, and from these comparisons, it can be seen that a microorganism-immobilized carrier with high treatment activity can be obtained when toilet paper or flour that is dissolved by microorganisms is added.

Moreover, this method is extremely inexpensive and easy to produce large sums of money.

Next, the culture conditions were changed as shown in Table 2 for the carrier (with 10 g of wheat flour added as the material to be decomposed) that had been gelled in exactly the same manner as in Example 1, and the culture conditions were b1 to b1. The relationship between b6 (TOC of culture solution and culture time) and treatment activity was measured.

The treatment activity was also measured in the same manner as in Experimental Example 1. - TOCI 20ppn 100d of artificial sewage 1
The treatment was carried out while flowing at a rate of 1 d/h, and 10-1 after the start of the test.
The T self-weight on the 4th day was measured to determine the TOC removal rate.

b6 is an example conducted for comparison, and is an example in which wheat flour as a material to be dissolved is not added.

From the results in Table 2, the introduction of the culture process has significantly improved the TOC removal rate, and the TOC of the culture solution is approximately 5/12 lower than the TOC used under normal processing conditions. .

The culture conditions are not limited to those in the experimental examples; it is sufficient that the microorganisms used are cultured for an appropriate amount of time with a low amount of substrate so as not to die, and the added materials are dissolved. A good effect is exhibited for about 1 week to 1 month at about 1/10 to 3/4 of the mass.

This is because the microorganisms produce more enzymes when they come into contact with the 9-layered substrate, increasing their activity.

First, to 100 g of an aqueous solution prepared by adding 1.1% of N,N-methylenebisacrylamide as a crosslinking agent to 16% of acrylamide monomer, 20 g of digested sludge wet bacterial cells with a water content of 90% and the digested sludge were added. and dry powder 109.

To this mixture was added 10 g of β-dimethylaminopropiontolyl as a 5% polymerization accelerator and 2% as a polymerization initiator.
．． After adding 10 g of 5% potassium peroxonisulfate, the microorganism-immobilized carrier is turned blue by placing it in a mold for forming a plate-like body with a thickness of 2 JuI and heating it to 35° C. to polymerize (gelatinize).

Then, 50 g of the microorganism immobilization carrier formed in this way was punched out into a disk shape with a diameter of 8 s+, and placed in a 100 d cylindrical container.
of artificial sewage was continuously flowed at a rate of 11 d/h.
The TOC removal rate was measured 31 to 35 days after the start of treatment, and the results are shown as C1 in Table 3.

Table 3 Here, C2 was prepared in the same manner as C1 except that 10 g of dry powder of digested sludge was not added.

A comparison between cl and 02 also shows that the addition of dry powder of digested sludge as an additive material results in a microorganism immobilization carrier with low treatment activity.

In addition, the additive materials include flour, toilet vapor,
In addition to dried powder of digested sludge, the main components are grain flour, cellulose fiber, yeast powder, dried microorganisms such as powdered sewage sludge, vegetable or animal fats and oils, carbohydrates, proteins, lipids, etc. I can give you things.

This additive material is effective in an amount of about 1 to 80% of the mixture of microbial cells and gelling material. If the amount is too small, the effect of addition will not be sufficiently exhibited, and if it is too large, the strength of the entire carrier will decrease.

In addition, the particle size of the additive material (dispersion diameter in the case of liquids such as oils and fats)
A value of 5M or less is desirable, and the smaller the value, the better the results.

In addition, in the examples, bacterial cells were mixed with acrylamide monomer, N,N'-methylenebisacrylamide, and lucium silicate as an entrapping immobilization material (gelling material). In addition to the entrapping immobilization material, substances such as minerals, cement, wood, synthetic resins, etc. that are not dissolved or are difficult to be dissolved by microorganisms may be added.

In addition, the entrapping immobilization material itself is not limited to the examples, but may include polyvinyl alcohol (PVA),
Acrylamide, sodium alginate, potassium alginate, ammonium alginate, carrageenan,
It can be appropriately selected from polyurethane, photocurable resin, etc.

Furthermore, the gelling step is not limited to the examples, and can be appropriately selected in consideration of the additive materials. For example, when polyvinyl alcohol is used as the entrapping immobilization material, it may be cooled to -6° C. or lower and frozen, then dried or brought into contact with boric acid. Also, algin Mm
When used, it is immobilized by contacting with calcium or aluminum salts.

〔Effect of the invention〕

As explained above, according to the method of the present invention, when forming a microorganism-immobilized carrier, a substance that can be dissolved by the physiological action of microorganisms is added prior to gelation, so that a large number of pores are formed. A microorganism-immobilized carrier with high treatment activity is easily formed.

In addition, the treatment activity can be further improved by introducing a step of culturing in the presence of a small matrix substrate prior to use.

Claims (6)

[Claims] (1) Immobilization of microbial cells, including a mixing step of mixing microbial cells and a first material that can be turned into a hydrogel by post-treatment to form a mixture, and a gelling step of turning this mixture into a gel. A method for immobilizing microorganism cells, wherein the mixing step includes a step of adding a second material that can be dissolved by the physiological action of the microorganism cells. (2) The method for immobilizing microorganism cells according to claim (1), wherein the second material is cellulose. (3) The method for immobilizing microorganism cells according to claim (1), wherein the second material is protein, starch, lipid, or a mixture thereof. (4) Immobilization of microbial cells, including a mixing step of mixing microbial cells and a first material that can be turned into a hydrous gel by post-treatment to form a mixture, and a gelling step of turning this mixture into a gel. In the method, the mixing step further includes the step of adding a second material that can be dissolved by the physiological action of the microbial cells, and after the gelling step, a small amount of the substance that becomes a substrate for the microbial cells is added. 1. A method for immobilizing microbial cells, comprising a culturing step of culturing under existing conditions. (5) The method for immobilizing microbial cells according to claim (4), wherein the second material is cellulose. (6) The method for immobilizing microbial cells according to claim (4), wherein the second material is protein, starch, lipid, or a mixture thereof.