JPH05115277A - Water scattering filter bed type bioreactor using comb type support - Google Patents

Abstract

PURPOSE:To obtain the subject device capable of completely preventing clogging by microbial cells while maintaining a large immobilized amount of the microbial cells by laminating a comb type support for immobilization of the microbial cells having a specific constitution in the interior and providing a spray nozzle for spraying a fermenting substrate from the upper part of the support. CONSTITUTION:A comb type support 5 for immobilization of a microorganism consisting of ceramics having 30-75wt.% porosity and a comb blade of 2-10mm thickness is laminated in a reactor 1 and, simultaneously, a spray nozzle 3 for spraying a fermenting substrate from the upper part of the support 5 is provided. Thereby vertical flow path 7 is provided between comb blades 6 and 6 to prevent the inside of the support from clogging by the microbial cells. Furthermore, it is preferable that vertical flow paths of upper and lower comb type supports 5... laminated in multi stage coincide with each other so as to prevent clogging.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved sprinkler filter type bioreactor used for causing a substrate to act on a microorganism to produce a useful substance.

[0002]

2. Description of the Related Art As a sprinkler filter bed type bioreactor used for the above purpose, as shown in JP-A-2-284694, a plurality of granular carriers randomly packed in the reactor is known. There is. However, in the case of using such a granular carrier, if the particle size of the granular carrier is made fine in order to increase the amount of immobilized cells and improve the productivity, it is possible to completely prevent clogging between the particles by the cells. I can't. On the contrary, when the particle size is increased, the clogging can be prevented, but the dead space inside the particle becomes large, and there is a problem that the productivity of the entire reactor decreases.

[0003]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, and can completely prevent occlusion by bacterial cells while maintaining a large amount of immobilized cells, which results in high productivity. It was made to provide a sprinkling filter type bioreactor using a comb-shaped carrier capable of obtaining

[0004]

DISCLOSURE OF THE INVENTION The present invention, which has been made to solve the above-mentioned problems, is for immobilizing microorganisms having a comb tooth with a porosity of 30 to 75% and a thickness of 2 to 10 mm. It is characterized in that a spray nozzle is provided for stacking the comb-shaped carrier of (1) in the reactor and spraying the fermentation substrate from above.

[0005]

The present invention will be described in more detail below with reference to the illustrated embodiments. In FIG. 1, 1 is a vertically long reactor, 2 is a fixed bed unit laminated inside the reactor 1, and 3 is a spray nozzle provided above the reactor 1. This type of reactor is used for anaerobic fermentations and fermentations with relatively low oxygen demand. For fermentation with a relatively high oxygen demand, or fermentation in which the concentration of the product cannot be increased unless the fermentation liquid is circulated, the circulation liquid is sucked from the bottom by the circulation pump 3 as shown in FIG. A reactor of the type that sprays water from the spray nozzle 4 is used. The following description will be given for an example using the reactor of FIG.

A large number of comb-shaped carriers 5 for immobilizing microorganisms as shown in FIGS. 3 and 4 are housed inside the fixed bed unit 2 of the present invention. These comb-shaped carriers 5 are provided with a large number of short comb teeth 6, and the groove formed between the comb teeth 6 serves as a vertical flow path 7. In order to prevent blockage, it is preferable that the vertical flow paths 7 of the upper and lower comb-shaped carriers 5 stacked in multiple stages be aligned. In the comb-shaped carrier 5 of FIG. 4, both the thickness and the protruding length of the comb teeth 6 are 5 mm.

In the present invention, the comb carrier 5 has a porosity of
It is composed of 30-75% ceramic material. The reason is shown in FIG. That is, FIG. 5 shows that the comb-shaped carrier 5 is made of various ceramics having different porosities, and the comb-shaped carrier 5 is set in the reactor 1 and fermented for one week. 6 is a graph in which the total amount of the immobilized bacterial cells and the bacterial cells floating in the fermentation solution) is shown on the left vertical axis, and the compressive strength of the comb carrier 5 itself is shown on the right vertical axis.

First, in the case of ordinary continuous fermentation using no carrier, the dry cell weight of the fermentation broth in the reactor is 8 g / L-reactor. There is no point in using a carrier unless you turn it around. Therefore, the porosity of the carrier must be 30% or more. Next, from the viewpoint of handling the carrier, the compressive strength is 20 kgf / cm ²
The following is not preferable. Therefore, the upper limit of the porosity of the carrier is
75%, and the porosity of the comb-shaped carrier 5 is
30 to 75%, more preferably 50 to 70%.

FIG. 6 is a graph showing the relationship between the thickness of the comb teeth 6 of the comb-shaped carrier 5 and the amount of bacterial cells in the reactor 1. In this case, various comb-shaped carriers 5 having comb teeth 6 having different thicknesses were placed in the reactor 1, and the total amount of bacterial cells in the reactor 1 after fermentation for one week was measured. As described above, the amount of bacterial cells when the carrier is not filled at all is 8 g / L-reactor, so it can be seen that it is meaningless to use the carrier when the thickness of the comb teeth 6 is 10 mm or more. This is because when the thickness is large, the cells cannot enter inside, and even if they enter, they cannot contact the fermentation liquid. On the contrary, when the thickness is reduced, the amount of bacteria increases, but it is difficult to form the comb teeth 6 having a diameter of 2 mm or less from ceramic.
It is preferably about 10 mm, and particularly preferably about 3 to 7 mm.

[0010]

The sprinkler filter bed type bioreactor of the present invention thus constructed has a method in which microorganisms are immobilized on the surface of a comb-shaped carrier 5 made of a ceramic having a porosity of 30 to 75% by a conventional method.
A substrate containing a nutrient source is supplied into the reactor 1 to produce useful substances by the action of microorganisms. The fermented liquor, which is a mixture of the produced useful substance and the substrate, flows down to the bottom of the reactor 1, is sucked up by the circulation pump 4 and is sprayed again from the spray nozzle 3 onto the comb-shaped carrier 5, and such circulation is performed. The concentration of the product is gradually increased while repeating the above, and a part of the product is taken out.

As described above, in the present invention, the fermentation liquid circulates inside the comb-shaped carrier 5 at all times, but since the vertical flow path 7 is secured between the comb teeth 6, the carrier made of bacterial cells There is no risk of internal blockage. Since the comb carrier 5 has a porosity of 30 to 75% and the comb teeth 6 have a thickness of 2 to 10 mm, it is possible to immobilize a large amount of bacterial cells on the surface layer while maintaining sufficient mechanical strength. it can. For this reason reactor 1
The production rate can be improved by maintaining the bacterial cell amount in the cell at a high level.

[0012]

INDUSTRIAL APPLICABILITY As described above, according to the present invention, by devising the shape of the carrier for immobilizing microorganisms, it is possible to prevent the clogging by the bacterial cells and maintain the bacterial cell amount in the reactor at a high level. It is possible. Therefore, the present invention is extremely important in contributing to industrial development as a sprinkler filter type bioreactor using a comb-shaped carrier that solves the conventional problems.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing an embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view showing another embodiment of the present invention.

FIG. 3 is a plan view of a comb carrier.

FIG. 4 is a perspective view of one comb-shaped carrier.

FIG. 5 is a graph showing the relationship between the porosity of a comb-shaped carrier, the weight of cells and the compressive strength of the carrier.

FIG. 6 is a graph showing the relationship between the thickness of comb teeth of a comb-shaped carrier and the weight of bacterial cells.

[Explanation of symbols]

 1 Reactor 2 Fixed Bed Unit 3 Spray Nozzle 4 Circulation Pump 5 Comb Carrier 6 Comb 7 Vertical Channel

Claims (1)

[Claims] 1. A comb-shaped carrier for immobilizing microorganisms having comb teeth with a porosity of 30 to 75% and a comb tooth thickness of 2 to 10 mm is laminated in a reactor, and a fermentation substrate is sprinkled from above. A sprinkler filter bed bioreactor using a comb-shaped carrier, characterized in that a spray nozzle is provided.