Screening method for preparing medium-molecular-weight dextran strain

Abstract

The invention discloses a screening method for preparing medium-molecular-weight dextran strains, belonging to the field of dextran. The present invention utilizes the microorganisms on the grape skins for cultivation, and modifies the cultured microorganisms with α-aminoisobutyric acid under the irradiation of an X-ray apparatus, filters the modified bacterial cell suspension, and smears the bacterial cell suspension Cultivate on a medium prepared by biotin, add 6-benzylaminopurine ethanol solution during the cultivation process, inoculate the cultured mycelium into a screening medium for cultivation, sieve, and finally collect strains. The present invention Using the microorganisms on the grape skin for modification, cultivation, and screening, the process is simple and the cost is low. The strains obtained by screening not only have high activity and good stability, but also use them to degrade dextran, and can obtain medium molecular weight dextran with uniform molecular weight distribution. , the quality and quality of dextran are good, the conditions of the degradation process are mild, and the energy consumption is small.

Description

technical field [0001] The invention discloses a strain for screening medium-molecular-weight dextran, which belongs to the field of dextran. Background technique [0002] Dextran, also known as dextran, is a polymer formed by the dehydration of several glucose. It is the first microbial polysaccharide discovered in the world and used as the main plasma substitute earlier. Dextran is a polymer formed by the dehydration of several glucans, which is mainly connected by α-1,6 glycosidic bonds of glucose. [0003] At present, the fermentation method is mostly used in China to prepare high-molecular dextran, and then hydrochloric acid is used to hydrolyze to obtain medicinal dextran with different molecular weights. Because the produced dextran contains a large amount of chloride, the quality and quality of dextran are seriously affected, and allergic reactions often occur during clinical use. Can cause skin reactions, severe respiratory and circulatory failure, and even death....

AI Technical Summary

Problems solved by technology

[0005] The technical problem mainly solved by the present invention is to regulate the molecular weight of dextran by traditional chemical method, mainly to degrade the dextran with large molecular weight into dextran with small molecular weight by hydrochloric acid. This method is difficult to control due to severe reaction conditions, and the produced dextran contains a large amount of chloride Seriously affecting the quality and quality of dextran, the present invention utilizes the microorganisms on the grape skin to cultivate, and the cultured microorganisms are modified with α-aminoisobutyric acid under the irradiation of an X-ray instrument, and filtered to obtain thallus after modification Suspension liquid, smear the bacterial cell suspension liquid on the culture medium made of biotin, add 6-benzylaminopurine ethanol solution during the culture process, inoculate the cultured mycelium into the screening medium for cultivation, and sieve Finally, it is enough to collect the strains. The present invention uses the microorganisms on the grape skins to modify, cultivate, and screen. The process is simple and the cost is low. The strains obtained by screening not only have high activity and good stability, but also use their Dextran, medium molecular weight dextran with uniform molecular weight distribution can be obtained, the quality and quality of dextran are good, the degradation process is mild, and the energy consumption is less