JPH07135958A - Agitated culture tank - Google Patents

Abstract

PURPOSE:To increase the amount of the substance produced by a microorganism, even when the reactor is stirred over a certain rotation number per minute by setting the baffle plates on the positions apart from the inner wall of the culture tank. CONSTITUTION:In the culture tank, baffle plates are arranged in the positions apart from the inner wall of the culture tank to make the bubble diameter small and make the vortex large in the culture mixture stirred with the stirring blades. Usually 2 to 8 baffle plates are set about 0.5 to 5cm, preferably about 0.5 to 2cm apart from the inner wall.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a stirred culture tank.
More specifically, the present invention relates to a stirred culture tank that achieves high efficiency of substance production by microorganisms.

[0002]

2. Description of the Related Art A substance is generally produced by microorganisms by using a stirring culture tank having a baffle plate directly attached to the inner wall surface of the culture tank. At that time, if the rotation speed of the stirring blade is increased,
The amount of substances produced will increase due to the increase in the number of contact with the substrate and the decrease in the diffusion layer around the microorganisms.

However, in reality, due to shearing of microorganisms by the stirring blades, bubbles in the culture broth with an increase in the stirring rotation number, especially an increase in the bubble diameter, the substance production amount rather decreases at a certain stirring rotation number. Like In addition, the substance production amount is greatly influenced by the vortex generated by the baffle plate installed in the culture tank.

[0004]

DISCLOSURE OF THE INVENTION An object of the present invention is to provide a stirring culture tank which not only reduces the amount of substances produced by microorganisms but rather increases the amount even when agitating at a stirring speed of a certain level or more. Especially.

[0005]

The object of the present invention is as follows.
In a stirring culture tank having a baffle plate, this is achieved by a stirring culture tank having the baffle plate installed at a position separated from the inner wall surface of the culture tank.

As the culture tank, any one such as a circular one and a rectangular one can be used, but a circular culture tank is generally used. Inside the circular culture tank, one or more baffle plates, generally about 2 to 8 baffles, are installed in the radial direction of the circular culture tank, and at this time, between the inner wall surface of the culture tank and the end face of the baffle plate. However, depending on the size of the circular culture tank, they are generally installed so as to be separated by about 0.5 to 5 cm, preferably about 0.5 to 2 cm. The baffle plate may have any shape, such as a rectangle or a right triangle, as long as the stirring effect is not impaired.

In such a culture tank, the stirring blades are generally installed at a position lower than the lower part of the baffle plate, and culture with various microorganisms is carried out while stirring the culture solution having a liquid surface at a position lower than the upper part of the baffle plate.

[0008]

By installing the baffle plate of the stirring culture tank at a position separated from the inner wall surface of the culture tank, the bubble diameter in the culture solution stirred by the stirring blade can be reduced and the generation of vortices can be increased. As a result, in the case of using a culture tank with a baffle plate directly attached to the inner wall surface of the culture tank, it is quite symmetrical with the sudden decrease in the amount of substances produced by microorganisms when the stirring speed is higher than a certain value. , The effect of increasing the amount of produced substances will be seen.

[0009]

EXAMPLES The present invention will now be described with reference to examples.

Example Using an incubator having the following structure, Enterbacter Cloacae No. 11-5
Production of indole acetic acid by (FERM P-8884) (Japanese Patent Laid-Open No. 63-4
The speed was measured.

A culture solution having a diameter of 10.5 cm is filled with a culture solution having an initial liquid level of 6 cm, and an inverted L-shaped baffle plate having a width of 2.5 cm and a thickness of 0.5 cm is 1.5 cm out of a length of 10 cm. It was placed 1.5 cm away from the inner wall surface of the culture tank so that the part of was immersed in the culture solution. Then, a stirring blade having a diameter of 8.0 cm was installed at a position 1.5 cm from the bottom of the culture tank.

In such a state, the liquid level depth (difference between the initial liquid level before stirring and the liquid level when stirring) when the stirring blade was rotated at 200 rpm or 300 rpm was
It was 1.1 cm and 1.5 cm. In addition, the bubble diameter (500 ml of an aqueous solution containing 0.1% surfactant was charged and stirred, after generating the bubbles, the stirring was stopped, and the diameter of the bubbles rising near the liquid surface was photographed and averaged) Was 0.30 mm.

Further, the indole acetic acid production rate (the stirring blade was rotated at a stirring speed of 750 rpm, and the mixture was incubated at 37 ° C.
Using NaH ₂ PO ₄ , 15% acetonitrile, pH 3.5 as developing solvent, column: Tosoh ODS.80TM, column temperature: 35 ° C,
The value obtained by dividing the concentration of indole acetic acid by HPLC measured by the conditions of flow rate: 2 ml / min and wavelength: 254 nm by the number of culture days) was 41.
It was μg / ml / day.

Comparative Example When a conventional culture tank was used and a baffle plate having a width of 2.5 cm and a thickness of 0.5 cm was installed in direct contact with the inner wall surface of the culture tank, the stirring blade was rotated at 200 rpm or 300 rpm. The liquid surface depth is 0.5 cm and 1.1 cm, respectively, and the bubble diameter is 0.28 mm.
Met. Indole acetic acid production rate is 6.5 μg / m
It was l / day.

The indole acetic acid (IAA) production rate when the stirring speed was variously changed in these Examples and Comparative Examples is shown in FIG. 1, and was produced by the microorganism when stirring at a stirring speed above a certain level. It can be seen that the amount of substance that is consumed increases.

[Brief description of drawings]

FIG. 1 Stirring speed and IAA in Examples and Comparative Examples
It is a graph which shows the relationship with a production rate.

Claims (1)

[Claims] 1. A stirring culture tank equipped with a baffle plate,
A stirring culture tank in which a baffle plate is installed at a position separated from the inner wall surface of the culture tank.