JPH048032B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for supplying a medium to a bioreactor such as a fermentor or a culture tank, and particularly to a method for supplying a medium to a fixed bed bioreactor.

[Conventional technology]

Bioreactors for fermentation or culturing of animal and plant cells are of the fluidized bed type, in which a carrier on which cells, enzymes, yeast, microorganisms, etc. (hereinafter collectively referred to as biocatalysts) are immobilized, is kept in a suspended state; There is a fixed bed type in which a tower or column is filled with a carrier on which is immobilized. Furthermore, fixed bed bioreactors are of the hollow fiber type using so-called hollow fibers such as hollow fiber as a carrier, and granular carriers such as foam glass.
It can be classified as a three-dimensional network carrier such as a porous ceramic material, a packed bed type using a honeycomb carrier, or a multilayer flat carrier. As shown in FIG. 4, an example of a packed bed type bioreactor is one in which a cylindrical tank is filled with a granular carrier on which a biocatalyst is immobilized to form a fixed bed. In the bioreactor shown in FIG. 4, the culture medium is supplied from the bottom of the tank, flows upward through the tank in a state similar to an extrusion flow, and is recovered from the top of the tank. Furthermore, the packed bed is composed of a mobile phase in which the medium is flowing and a stationary phase (packed phase) in which the flow is slow.

[Problem to be solved by the invention]

However, in the above-mentioned bioreactor, the concentration of nutrients and dissolved As shown in FIG. 5, the oxygen concentration and useful substance productivity decrease from the bottom to the top, while the waste product concentration increases. Therefore, there is a problem in that the metabolic activity of the biocatalyst is low on the exit side of the bioreactor (upper part in the illustrated example) and the biocatalyst does not function effectively. Such problems are
This problem also occurs in horizontal bioreactors in which the tank axis is horizontal, and also in fixed bed bioreactors, whether hollow fiber or packed bed.

The present invention was devised in view of the above circumstances, and an object of the present invention is to provide a culture medium supply method that allows a biocatalyst in a fixed bed bioreactor to function effectively.

[Means to solve the problem]

In the present invention, a plurality of culture medium supply nozzles having different lengths to the tip are disposed on the circumference at approximately equal intervals and in the same direction in parallel to the axial direction in the tank of a bioreactor, The culture medium is supplied from the tip of the nozzle to the fixed layer arranged in the tank.

[Effect]

The medium is uniformly supplied to the entire fixed layer of the bioreactor by flowing out the medium from the tips of the medium supply nozzles that are distributed in the axial and circumferential directions within the cylindrical tank of the bioreactor.
The gradients of nutrient concentration, dissolved oxygen concentration and waste product concentration in the mobile phase are small. Therefore, the metabolic activity of the biocatalyst fixed on the fixed bed is maintained in a uniform and high state, and the biocatalyst functions effectively.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 and FIG. 2 are a vertical cross-sectional view and a cross-sectional view of a packed bed type bioreactor among the fixed bed type bioreactors for explaining one embodiment of the culture medium supply method of the present invention. In FIGS. 1 and 2, a bioreactor 1 has a cylindrical tank 2 with its axial direction horizontal and both ends connected to flange seal members 20 and 2, respectively.
A cylindrical mesh 4 is arranged concentrically with the tank 2 inside the tank 2, and a plurality of oxygen supply pipes oriented in the same axial direction are installed inside the mesh 4. 6. A medium recovery pipe 8 is provided. Further, the inside of the mesh 4 is filled with a carrier for immobilizing enzymes, cells, etc. A plurality of culture medium supply nozzles 10 are disposed on the outside of the mesh 4 and between it and the tank 2.

The tank 2 may be made of ordinary bioreactor materials such as glass or metal.
The diameter and length of the bioreactor can be appropriately determined depending on the scale of the bioreactor.

The flange seal members 20 and 22 that close both ends of the tank 2 may be made of the same material as the tank 2. As shown in FIG. 3, on the surface 20a of the flange seal member 20 exposed in the tank 2, a plurality of culture medium supply nozzles 10 are arranged approximately equally on a circumference concentric with the outer circumference of the surface 20a. They are arranged perpendicularly to the surface 20a at intervals. An opening is formed in the tip 10a of this culture medium supply nozzle 10, and the length from the surface 20a to the tip 10a (nozzle length)
may be changed periodically. That is, the nozzle length may be determined so that the tip portion 10a draws a shape such as a sine curve or a rectangular wave along the circumferential direction of the medium supply nozzle 10. The number and nozzle length of the culture medium supply nozzles 10 can be appropriately determined depending on the scale of the bioreactor so that the tips 10a are uniformly distributed in the axial and circumferential directions of the tank 2. Further, in the illustrated example, the culture medium supply nozzles 10 are arranged so as to be located on a single circumference, but they can also be arranged so as to be located on a plurality of circumferences. As shown in FIG. 1, inside the flange seal member 20, a culture medium supply channel 21 for feeding the culture medium to the culture medium supply nozzle 10 is formed.

Also, inside the flange seal member 22, there is an oxygen supply channel 23 for sending oxygen to the oxygen supply pipe 6, and a culture medium recovery pipe 8 to send recovered culture medium, products, waste materials, etc. to the next process. A medium recovery channel 24 is formed for this purpose.

The mesh 4 may be, for example, a wire mesh formed by spirally winding wire at regular intervals on the outside of support rods arranged at equal intervals on the same circumference, or a wire mesh made of punched metal, etc. That's fine. This mesh 4 is concentric with the tank 2 and has both open ends connected to flange seal members 20, 22.
Therefore, the inside of the tank 2 is divided into an inner and an outer part by a mesh 4, and the inside of the mesh 4 is filled with a carrier for immobilizing the biocatalyst.

The oxygen supply pipe 6 replenishes the oxygen consumed in the culture medium by the biocatalyst to keep the dissolved oxygen concentration of the culture constant, and the oxygen sent through the oxygen supply channel 23 supplies oxygen. It passes through the wall of the pipe 6 and is replenished into the culture medium. In this case, in order to protect biocatalysts that do not have cell membranes, such as animal and plant cells, from the shearing force that occurs when oxygen bubbles disappear, the oxygen supply pipe 6 supplies oxygen into the culture medium in a non-foaming state. is preferred. As such an oxygen supply pipe 6, for example, a porous sintered material is used.
There are those in which the SUS support pipe is covered and sealed with a water-repellent porous Teflon membrane, and those in which a water-repellent silicon thin film is formed on the outer peripheral wall of the porous sintered SUS support pipe.

In the example shown in FIG. 2, six such oxygen supply pipes 6 are arranged at equal intervals inside the mesh 4 so as to be located on a circumference concentric with the mesh 4. The number and location of the oxygen supply pipes can be determined as appropriate depending on the scale of the bioreactor.

The medium recovery pipe 8 is for recovering the products, used medium, and waste products produced in the bioreactor and sending them to the next process (purification process, etc.).
The opening side of a porous sintered SUS pipe with an opening on one side is connected to the culture medium recovery channel 24 of the flange seal member 22. In the example shown in FIG. 2, a total of seven culture medium recovery pipes 8 are arranged, six at equal intervals and one at the center so as to be located on a concentric circumference inside the mesh 4. .

Next, the supply of the medium in the above-mentioned bioreactor will be explained.

Culture medium supply channel 2 in flange seal member 20
The culture medium sent into the tank 2 and the mesh 4 from the opening of the tip 10a of each culture medium supply nozzle 10
It leaks into the part between and. Here, as described above, since each culture medium supply nozzle 10 is arranged so that the tip portion 10a is uniformly present in the axial direction and circumferential direction within the tank 2, the culture medium is uniformly distributed outside the mesh 4. supplied to The supplied medium passes through the mesh 4 and flows toward the inside of the tank 2 in the radial direction, and is recovered together with products, wastes, etc. from the medium recovery pipe 8 and sent to the next process. According to the present invention, since the culture medium is supplied as described above, it passes only through the mesh 4 in the vicinity of the flange seal member 20 (medium supply side), and passes through the mesh 4 in the vicinity of the flange seal member 22 (medium recovery side), for example. The occurrence of so-called shoot passes, where fresh medium is not supplied to the biocatalyst, is effectively prevented.

The present invention is not limited to the above-mentioned bioreactor in which the culture medium flows in the radial direction in the tank, but
It is also applicable to the vertical bioreactor shown in the figure and the horizontal bioreactor shown in FIG. 4, which is made horizontal. Furthermore, the present invention is applicable even if the fixed layer for immobilizing the biocatalyst is any known carrier with excellent biocompatibility, such as a granular carrier, a three-dimensional network carrier, a honeycomb carrier, a multilayer flat carrier, or a hollow fiber carrier. can do.
That is, in the packed bed type vertical bioreactor using the granular carrier shown in FIG. 4, by arranging the culture medium supply nozzle 10 as shown in FIG. 3 from the bottom of the tank to the top, Since the tip portions 10a are uniformly dispersed in the granular carrier in the tank, it is possible to uniformly supply the culture medium to the packed bed.

Further, biocatalysts to which the present invention is applicable include various biocatalysts such as adherent animal cells, yeast, and microorganisms.

〔Effect of the invention〕

According to the present invention, the culture medium is uniformly supplied to the entire fixed layer from the tips of the culture medium supply nozzles located dispersedly in the axial and circumferential directions in the cylindrical tank of the bioreactor, and is fixed to the fixed bed. The metabolic activity of the biocatalyst being used is maintained at a uniform and high level,
The biocatalyst functions effectively and the production efficiency of products in the bioreactor is improved.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a bioreactor for explaining one embodiment of the present invention, FIG. 2 is a cross-sectional view of the same, and FIG. 3 is an example of a medium supply nozzle for implementing the present invention A perspective view, FIG. 4 is a diagram showing a conventional packed bed type bioreactor, and FIG. 5 is a diagram showing a concentration gradient in the conventional packed bed type bioreactor. 1...bioreactor, 2...tank, 4...
mesh, 6... oxygen supply pipe, 8... culture medium recovery pipe, 10... culture medium supply nozzle, 2
0, 22... Flange seal member, 21... Channel for medium supply, 23... Channel for oxygen supply, 24...
Channel for medium recovery.

Claims (1)

[Scope of Claims] 1. A plurality of culture medium supply nozzles having different lengths to the tip are arranged on the circumference at approximately equal intervals and in the same direction in parallel to the axial direction in the tank of the bioreactor, A culture medium supply method for a fixed bed bioreactor, characterized in that a culture medium is supplied from the tip of the culture medium supply nozzle to a fixed bed arranged in the tank. 2. The culture medium supply nozzle is located near the inner circumferential wall of the tank, and the culture medium supplied from the tip of the culture medium supply nozzle flows inside the tank from the outside in the radial direction toward the inside. The method for supplying a culture medium to a fixed bed bioreactor according to claim 1. 3. The culture medium supply nozzle is located near the center axis of the tank, and the culture medium supplied from the tip of the culture medium supply nozzle flows inside the tank from the inside in the radial direction to the outside. The method for supplying a culture medium to a fixed bed bioreactor according to claim 1.