JPS59220182A - Cultivation tank - Google Patents

Abstract

PURPOSE:To provide an aerobic cultivation tank free from ventilation and having little danger of the contamination with sundry germs, by using a water-repellent gas-permeable membrane as a part of the wall contacting with the liquid phase, and attaching a ventilation hole furnished with a water-repellent gas- permeable membrane to the wall contacting with the vapor phase. CONSTITUTION:In the cultivation tank composed of the top plate 1 made of stainless steel, the glass cylinder 2, etc., the bottom plate contacting with the liquid phase is composed of a water-repellent gas-permeable membrane 3, and a ventilation hole 11 furnished with a water-repellent gas-permeable membrane 12 is attached to the wall contacting with the vapor phase to equilibrate the pressure in the tank to atmosphere during the steam sterilization. The shielding of the cultivation tank from the outer atmosphere is made complete by the use of the above water-repellent gas-permeable membrane. The membrane is preferably porous Teflon film. Oxygen is permeated through the water-repellent gas-permeable membrane attached to the wall contacting with the liquid phase, and is dissolved in the culture liquid. The tank has various advantages such as the simplified structure, the lowered danger of the contamination with sundry germs, the retention of bubbles in the cultivation tank, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a culture tank. In aerobic culture, sterile air is usually aerated into the culture tank. However, in order to deliver sterile air, not only compressed air is required as equipment (the culture tank also requires a filter, an air inlet/outlet, a sparger, etc.).

These things complicate the device, cause bacterial contamination, and furthermore, if bubbles are generated, there is a risk that the culture solution will spill out from the air outlet along with the bubbles. In addition, the culture solution evaporates due to aeration, resulting in a significant decrease in the amount of the solution.

JP-A-54-9268 discloses a method for efficiently sending oxygen gas and quickly dissolving it in the culture solution during aerobic culture.
It is taught in Publication No. 7.

In this method, oxygen gas is introduced into a gas phase formed by an air-permeable water-repellent membrane, and the oxygen can be dissolved into the culture medium through the membrane due to a partial pressure difference.

The present invention relates to an improvement of a device for implementing the above method. That is, the culture tank is characterized in that a portion of the wall in contact with the liquid phase portion is formed of a water-repellent gas-permeable membrane, and a vent hole is further provided in the wall in contact with the gas phase portion.

The present invention provides an aerobic culture tank without ventilation. That is, the present invention is a culture tank in which a part of the wall is made of a water-repellent gas-permeable membrane, and a ventilation hole is provided in the wall that contacts the aerobic part, which is useful for maintaining pressure balance during steam sterilization.

If the ventilation holes are formed with a water-repellent gas-permeable membrane that blocks the atmosphere from the outside world, the culture tank will be completely isolated from the outside world.

The culture tank is cylindrical, and if part or all of its bottom is made of a water-repellent gas-permeable membrane, it can be used in the same way as a normal aerated culture tank. A porous Teflon membrane is preferably used as the water-repellent gas-permeable membrane. This culture tank may be stirred using a stirring method using a normal stirring blade, or may be stirred using a method in which the culture tank is shaken. When this culture tank is used, oxygen passes through a water-repellent gas-permeable membrane provided on the wall in contact with the liquid phase and is dissolved in the culture solution.

When this culture solution is used, there is no need to provide any other entrances and exits for the air, so the culture tank becomes airtight, which not only simplifies the equipment, but also has the advantage that there is no risk of bacterial contamination. The culture solution passes through the water-repellent gas-permeable membrane and evaporates, but the amount of evaporation is significantly smaller than that in the case of aeration.

Furthermore, in order to accommodate the oxygen demand of various microorganisms, a culture tank may be used in which the area ratio of the gas permeable membrane to the volume is adjusted.

Ventilation holes provided on the walls in contact with the gas phase are necessary to maintain the same pressure inside and outside of the original seeds to be steam sterilized by putting the culture solution into the culture tank. There is a risk that pressure will be applied to the water-repellent gas-permeable membrane that forms the membrane, causing damage to the membrane.

Next, the present invention will be specifically described with reference to the accompanying drawings. FIG. 1 shows a top view of an embodiment of the present invention, and FIG. 2 shows a longitudinal sectional view thereof. The culture tank has 1 stainless steel top plate and 2 glass cylinders.
It is a container whose bottom surface is formed of a water-repellent gas-permeable membrane 6, and the upper and lower ends of the glass cylinder 2 are sealed with rubber gaskets 4, respectively. These are fixed between the stainless steel ring 5 and the top plate 1 with a support 6 and a nut 7. P on top plate 1
There are nozzles including an H electrode hole 8, a dissolved oxygen electrode hole 9, a liquid feed hole 10, and a ventilation hole 11. The vent hole is also used as an inoculation hole. The vent hole 11 is equipped with a water-repellent gas-permeable membrane 12 that blocks the gas phase of the culture tank from the outside world, and is effective for maintaining pressure balance during autoclave sterilization. There is a buntle plate 161 in the culture tank. < f i 14, bearing 15
, a rotating shaft 16, a turbine blade 17, a magnetic stirrer 18, and the like. A washer 19 and a wire mesh 20 are placed under the water-repellent gas-permeable membrane 6 on the bottom to support the weight of the culture solution. In this culture tank, oxygen passes through the gas permeable membrane 6 and dissolves in the culture solution. This dissolution rate depends on the area of the gas permeable membrane 60 and gas permeability. As the gas permeable membrane 6, various materials such as silicon thin ML, porous Teflon, synthetic resin membrane, water-repellent metal mesh, etc. can be used, but the permeation rate of the silicon thin film is higher than that of porous Teflon. Below, heat resistance,
Porous Teflon membranes are also superior in terms of economy and ease of use.

FIG. 6 shows the rotating mechanism of the previous embodiment, namely the stay 14, bearing 15, rotating shaft 16, turbine blade 17, and magnetic stirrer 1.
8 is removed, and even if it is rotated or shaken reciprocally, it can be used in the same way as a conventional shaking culture tank such as a triangular 7 Cisco or Sakaro flask. By shaking this culture tank, you can obtain information about the culture solution using electrodes that could not be obtained with conventional flasks.Although flasks are convenient, the relationship with a stirred culture tank is advantageous (although it was good, this Culture tanks have advantages such as being similar in shape, making it easy to obtain correlations, and selecting a gas-permeable membrane to achieve a high oxygen dissolution rate, which allows for higher bacterial concentration and larger liquid volume compared to flasks. In this example, the diameter is 7 cm and the height is 1.
Oxygen permeation rate when the bottom of a 4c1n culture tank is made of a porous Teflon membrane with a pore size of 5 microns and a thickness of 200 microns, and when the bottom is made of a metal plate and the vent hole with an inner diameter of 25 Tnm is plugged with a bolt. When compared, the former was about 7 times faster.

A bacterial contamination test using a bouillon medium was carried out for 4 days while rotating the culture tank, but no contamination was found. During this test, the culture solution evaporated and decreased, so sterile water was added during the test.

[Brief explanation of drawings]

1 and 2 show a top view and a vertical sectional view, respectively, of an embodiment of the present invention. FIG. 3 is a partially cutaway sectional view of another embodiment) FIG. 4 shows another embodiment of the ventilation hole. Main wing of code 1 Stainless steel top plate 2 Glass cylinder 3 Water-repellent gas permeable membrane 4 Rubber gasket 5 Stainless steel ring 6 Support 7 Nut 8 p) I electrode hole 9 Dissolved oxygen electrode hole 10 Liquid feed hole 11 Vent hole 12 Water-repellent gas permeable Membrane 16 Baffle plate 14 Stay 15 Bearing 16 Rotating shaft 17 Turbine blade 18 Magnetic stirrer 19 Washer 20 Wire mesh Name 11Y 2 Mouth stone 3 Diagram

Claims (1)

[Claims] 1. A culture tank characterized in that a part of the wall in contact with the liquid phase portion is formed of a water-repellent gas-permeable membrane, and further vent holes are provided in the wall in contact with the air layer portion. . 2. The culture tank according to item 1, characterized in that the ventilation holes are formed with a water-repellent gas-permeable membrane. 6. The first aspect, characterized in that the culture tank is cylindrical, and a part or all of the bottom of the tank is made of a water-repellent gas-permeable membrane.
Culture tank described in section. 4. The culture tank according to item 1 or 2, wherein the water-repellent gas-permeable membrane is a porous Teflon membrane. 5. The culture tank according to item 1 or 2, wherein the culture tank is of a shaking type.