Fermentation technology for improving production level of recombinant collagen

Abstract

The invention provides a fermentation technology for improving the production level of recombinant collagen, and relates to the technical field of genetic recombination engineering bacterium fermentation. The fermentation technology for improving the production level of the recombinant collagen comprises the following steps of: S1, pichia pastoris engineering bacteria are inoculated into a seed tank to be cultured, glycerin and a supplemented medium are supplemented after dissolved oxygen is greatly increased, and when wet weight is increased to be larger than 100 g / L, the pichia pastoris engineering bacteria are transferred into a fermentation tank to start fermentation culture; S2, after the pichia pastoris engineering bacteria in the fermentation tank are cultured till the dissolved oxygen is greatly increased, a mixed carbon source material supplementation is carried out by using a carbon source culture medium and a supplemented medium, and the mixed carbon source material supplementation is stopped when the wet weight of the material is increased to be greater than 150g / L; and S3, after the carbon source is used up, methanol and the supplemented medium are added for carrying out induced expression until fermentation is finished. The fermentation technology disclosed by the invention can improve the expression quantity of the recombinant collagen and shorten a fermentation period, so that the fermentation production level of the recombinant collagen is improved, and the fermentation technology is suitable for stable industrial production.

Description

technical field [0001] The invention relates to the technical field of gene recombination engineering bacteria fermentation, in particular to a fermentation process for improving the production level of recombinant collagen. Background technique [0002] Collagen is the most abundant protein in the body and the main component of the extracellular matrix (ECM), which plays an important role in maintaining the normal physiological functions of cells, tissues and organs and repairing damage. Because of its unique structure, collagen has excellent biocompatibility and low immunogenicity, and has been widely used in medicine, health care products and cosmetics industries. [0003] In the prior art, the main source of collagen is animal tissue extraction, and with the development of biotechnology, the use of gene recombination technology, recombinant collagen obtained through microbial fermentation has achieved great results, compared with natural collagen, The recombinant collag...

AI Technical Summary

Problems solved by technology

[0005] (1) Use BSM medium to cultivate seeds, the wet weight is 90-100g / L, the overall bacterial count is low, and the lag period after being transferred into the fermentation medium is long, which affects the overall production level;

[0006] (2) The concentration of salt ions in the BSM medium is too high, which inhibits the growth of the bacteria and affects the vitality of the bacteria, making it difficult to quickly reach the high-density fermentation level;

[0007] (3) Glycerin is viscous, and an excessively high proportion affects the oxygen mass transfer and the uniformity of the feed liquid;

[0008] (4) The high salt of BSM medium and the single use of glycerol and methanol can easily lead to the decline of bacteria in the middle and late stages, the increase of protease secretion, and the intensification of protein degradation, thereby affecting the quality of the overall protein;

[0009] (5) BSM medium contains high concentration of phosphoric acid, the initial pH of the medium is lower than 1.5, which will greatly damage the electrodes and other components, seriously affecting the service life of the fermenter;

[0010] (6) BSM medium and feed glycerin and methanol contain PTM1. PTM1 is complicated to prepare and cannot be sterilized by high temperature, and requires sterile filtration, which causes great troubles for industrial scale-up;

[0011] (7) Pichia engineered bacteria need the introduction of pure oxygen to maintain dissolved oxygen, which increases production costs on the one hand, and on the other hand, pure oxygen is flammable and explosive, which is likely to cause safety accidents

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