Characteristics and development of biological fermentation technology

Biotechnology (boteChnobgy) is a technology that uses biological systems, living organisms and their derivatives to produce or improve products or processes for specific uses. Modern bioengineering techniques include geneengnwing, cell engineering `WILL process' has a MILA (production procedures).

The microbial fermentation process, that is, the microbial reaction process, refers to the biochemical reaction process caused by the growth and reproduction of microorganisms.

According to the different types of microorganisms (aerobic, anaerobic, facultative anaerobic), it can be divided into two categories: aerobic fermentation and anaerobic fermentation.

(1) Aerobic fermentation In the fermentation process, it is necessary to continuously pass a certain amount of sterile air, such as citrate fermentation by Aspergillus niger, glutamic acid fermentation by coryneform bacteria, polysaccharide fermentation by using yellow bacterium, etc. Wait.

(2) Anaerobic fermentation It is not necessary to supply air during fermentation, such as lactic acid fermentation by Lactobacillus, acetone, butanol fermentation by Clostridium.

(3) The facultative yeast is a facultative anaerobic microorganism that accumulates alcohol under anaerobic fermentation under anoxic conditions, and aerobic fermentation under aerobic or aeration conditions, and multiplies the cells.

According to the equipment, fermentation can be divided into open fermentation, closed fermentation, shallow fermentation and deep fermentation.

Generally, open-type fermentation is applied to a type that is fast-growing and aerobic fermentation, such as yeast production, which can inhibit the growth of other bacteria due to the rapid proliferation of the bacteria. Therefore, the requirements for open fermentation equipment are simple. On the contrary, the closed fermentation is carried out in a closed device, so the equipment is strict and the process is complicated. Shallow tray fermentation (surface culture method) is to use a shallow plate to hold only a thin layer of culture solution, and then carry out surface culture after receiving human strains to form a layer of bacteria on the liquid. In the absence of ventilation equipment, this method can be used for some fast-growing aerobic microorganisms. Submerged fermentation refers to the process of microbial culture carried out inside a liquid medium (not just on the surface).

Compared to other fermentation methods, it has many characteristics:

1 The liquid suspension state is a suitable environment for the growth of many microorganisms.

2 In the liquid, the bacteria and nutrients, products (including heat) are easy to spread, so that the fermentation can be carried out under homogeneous or pseudo-homogeneous conditions, which is easy to control and easy to expand the scale of production.

3 liquid transport is convenient, easy to mechanized operation.

4 The workshop area is small, the production efficiency is high, the automation is easy to control, and the product quality is stable.

5 products are easy to extract, refine and so on. Therefore, liquid submerged fermentation is widely used in the fermentation industry.