JPH048799Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) The present invention is a stirred tank type culture device, in particular, a porous substance is fixed to the stirring blade so that microbial cells released in the culture solution can be absorbed into the porous substance. The present invention relates to a culture device for culturing cells therein.

(Prior Art) When various microorganisms, including molds and other filamentous fungi and actinomycetes, are cultured in liquid culture in a culture tank, the microorganism cells grow in the form of pellet growth or pulpy growth, depending on the type of microorganism. Pellet growth refers to a growth form in which microbial hyphae become entangled with each other during culture to form granular cell clusters and grow. Pellet growth is observed, for example, in the production process of penicillin. What is pulpy proliferation?
It refers to a growth form in which microbial cells grow while being uniformly distributed in a culture solution, and is observed, for example, in the production process of streptomycin. When pellet growth occurs, the cell growth rate is extremely low. When pulpy multiplication occurs, the proliferated microbial cells exist in a uniformly mixed state in the culture solution, and therefore the viscosity of the culture solution becomes extremely high. Therefore, a large amount of power is required to stir the culture solution. In both pellet growth and pulpy growth, microbial cells exist in a mixed state in the culture solution, making it difficult to separate and extract metabolites from the culture solution. Monitoring of the culture fluid also becomes cumbersome and time consuming.

In order to overcome these disadvantages of pellet growth or pulpy growth, the present inventors have proposed a method of culturing microorganisms by dispersing in a culture medium a porous material that is not metabolized by microorganisms (particularly (Gan Sho 59-71515). According to this method, the microorganisms to be cultured grow within the pores of the porous material, such as polyurethane foam. Since the inner surface of the porous material has a large contact area with air, sufficient air is supplied to the microorganisms present in the pores of the porous material, and the microorganisms multiply extremely rapidly. Moreover, since there are almost no bacterial cells in the culture solution, microbial cells do not undergo pellet growth or pulpy growth. Therefore, no particularly large power is required to stir the culture solution. However, when this culture method is used in a normal stirred tank type culture device, the culture solution cannot be uniformly stirred because the bacterial cells and porous substances are held still by stirring blades or baffles on the inner wall of the tank. In addition, bacterial cells adhere to the DO (dissolved oxygen concentration) sensor, making it impossible to accurately monitor the pH and DO of the culture solution. Therefore, accurate PH control and
There is a problem that the DO cannot be controlled.

(Problems to be solved by the invention) The present invention solves the above-mentioned conventional problems, and its purpose is to minimize the adhesion of bacterial cells to the inner wall of the tank and various sensors, and to reduce the amount of culture fluid. It is an object of the present invention to provide a stirring tank type culture device capable of uniformly stirring. Another purpose of the present invention is to maintain the viscosity of the culture solution at a low level by suppressing pellet growth and pulpy growth in the culture solution of bacterial cells, thereby making it possible to uniformly stir the culture solution. The purpose of this invention is to provide a culture device.

(Means for Solving the Problems) In the stirred tank type culture device of the present invention, a porous substance is fixed to at least a portion of the stirring blade, thereby achieving the above object.

The culture device itself and the stirring blade used in the present invention are both devices and blades that are commonly used for liquid culture of microorganisms, and do not need to be anything special. For example, a synthetic resin foam can be used as the porous material to be fixed to the blade.
As the synthetic resin foam, for example, a foam made of polyvinyl alcohol, polyurethane, or the like is used. In particular, polyurethane foams having a polyoxyethylene structure are preferably used because they have excellent hydrophilicity and water retention ability.

Such polyurethane is obtained by reacting a polyol having a polyoxyethylene structure with a polyisocyanate. Examples of polyols having a polyoxyethylene structure include polyethylene glycol; a mixture of polyethylene glycol and polypropylene glycol; and polyethylene glycol-polypropylene glycol, which is a copolymer of ethylene oxide and propylene oxide. Basic polyols can also be used. The basic polyol here is obtained by adding ethylene oxide polyoxyethylene to amines such as ethylenediamine, diethylenetriamine, methylamine, butylamine, piperazine, ethynolamine, propanolamine, and N-methyldiethanolamine. As the polyol having a polyoxyethylene structure, polyethylene glycol having a molecular weight of about 400 to 1000 is preferably used. When the polypropylene component is added to the polyethylene glycol, it is preferred that its content be less than about 80 parts by weight. If it is in excess, the hydrophilicity of the resulting foam will decrease.

As the above-mentioned polyisocyanate, various polyisocyanates such as aromatic, aliphatic, and polyether are used. Examples include tolylene diisocyanate, diphenylmethane diisocyanate, diphenyl diisocyanate, naphthalene diisocyanate, xylene diisocyanate, butane diisocyanate, triphenylmethane-4,4',4''-triisocyanate, and the like.

Polyols that do not have a polyoxyethylene structure can also be used alone or in combination with the polyols that have a polyoxyethylene structure. Examples of such polyols include glycerin, trimethylolethane, trimethylolpropane, 1,2,6-hexanetriol, pentaerythritol, sorbitol, sutucarose,
α-methyl glucoside is mentioned. Natural polymers such as cellulose, carboxymethylcellulose, and hydroxymethylcellulose and derivatives thereof can also be used as polyols.

When a peptide such as collagen, albumin, or gelatin is present in the reaction system during the reaction between a polyol and a polyisocyanate, a polyurethane in which a peptide matrix is formed within the molecule can be obtained. Peptides are biocompatible materials, so using polyurethane foam with a peptide matrix formed within the molecule as a porous material increases the affinity between microorganisms and the porous material, allowing microorganisms to grow more quickly. Become.

As the foam, both semi-open foam and open foam can be used. It is preferable to use open foam because the wider the air-liquid surface where the culture medium and air come into contact, the better.

The average pore diameter of the porous material is 10 μm to 10 μm, preferably 100 μm to 3 mm. If the pore diameter is too small, it becomes difficult for microorganisms to penetrate into the porous material, and if it is too large, the internal surface area of the porous material becomes small.

(Example) The present invention will be described below with reference to embodiments.

The stirred tank type culture device of the present invention has a culture tank 1 and a stirring blade 2 provided around a rotating shaft 20, as shown in FIGS. 1 and 2. Culture tank 1
A baffle plate 3, a bubble cutter 4, a ventilation pipe 5, a PH sensor 6, a temperature sensor 7, a DO sensor 8, etc. are provided as appropriate.

The shape and structure of the blades 21 constituting the stirring blades 2 are not particularly limited, as long as they can uniformly stir the culture solution in the culture tank 1. The wings 21 are, for example,
A plurality of them are arranged around the rotating shaft 20 in the lower part and the center part of the culture tank 1. This wing 21 is provided with a porous material 22 made of synthetic resin foam.
It is fixed so as to wrap around each of 1.
An adhesive or a suitable fixing means is used to fix the porous material 22.

As the stirring blade 2, for example, as shown in FIG. 3, the same effect can be achieved even if porous material 22 is fixed only to each tip of the blade 21 in FIG. 1. As shown in FIG.
It is also possible to fix the blade and configure it in the shape of a single blade. Porous material 2 fixed to these wings 21
2 are arranged such that their tips are in contact with the baffle plate 3, various sensors 6, 7, and 8, etc. The microbial cells are effectively incorporated into the porous material 22 through culturing, and do not adhere to the baffle plate 3 or the various sensors 6, 7, and 8. Cells entrapped within the porous material 22 proliferate therein. Since the cells are present in the culture solution and do not proliferate therein, there is almost no increase in the viscosity of the culture solution, and therefore the culture solution is uniformly stirred. Various sensors are kept clean at all times because cells do not stagnate there. As a result, PH monitoring and DO monitoring can be performed accurately, and culture conditions can be maintained at predetermined optimal conditions throughout the culture period. This makes the growth of cells within the porous material 22 more efficient.

This device is particularly useful for culturing molds and actinomycetes that take the form of pellet growth or pulpy growth, but it goes without saying that it can also be applied not only to the culture of other microorganisms but also to the culture of plant cells. .

(Effect of the invention) A porous material is fixed to at least a part of the stirring blade, and the porous material is arranged so that all of them are located in the culture solution. It is possible to prevent microorganisms from multiplying in the culture solution, thereby suppressing an increase in the viscosity of the culture solution, and also to prevent microorganisms from multiplying in the culture solution. It has the advantage that it prevents the adhesion of dirt and allows various controls to be performed accurately.

[Brief explanation of the drawing]

FIGS. 1 and 2 are a sectional front view and a sectional plan view showing one embodiment of the stirred tank culture device of the present invention, respectively, and FIGS. 3 and 4 are perspective views showing other embodiments, respectively. . 1... Culture tank, 2... Stirring device, 3... Baffle plate, 4... Bubble cutter, 5... Ventilation pipe, 6... PH sensor, 7... Temperature sensor, 8... DO sensor, 20... ...rotating shaft, 21...blade, 22...porous material.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. A stirring device comprising a culture tank, stirring blades disposed in the culture tank, and a ventilation pipe for supplying oxygen to a culture solution placed in the culture tank. A tank-type culture device, at least a part of the stirring blade,
A stirring tank type culture device in which a porous material capable of taking microbial cells inside is fixed such that it is always located in the culture solution while the stirring blade rotates. 2 Utility model registration claim 1 in which the porous material is a foam made of polyvinyl alcohol or a foam made of polyurethane.
The equipment described in section.