Medium temperature Alpha-amylase high yielding strain and building method thereof

Abstract

The invention relates to a medium temperature Alpha-amylase strain and a building method thereof. Bacillus subtilis AS 1.108 medium temperature Alpha-amylase gene obtained by PRC is cloned to bacillus subtilis expression plasmid pWB980 and is switched to WB600 to facilitate medium temperature Alpha-amylase to obtain high expression. The medium temperature Alpha-amylase gene has 1431 basic groups and codes 447 amino acids. The molecular mass of recombinase is 49.1KDa by SDS-PAGE detection, the optimal operation temperature and pH value are 60 DEG C and 6.0 respectively. The activity of the enzyme is about 2 times of the activity of the original strain, thus the problems of stink generated by the original strain and long fermentation period are solved. The method not only saves grains for industrial uses, reduces cost and provides better condition for deep processing of starch material, but also greatly reduces energy consumption and better suits industrialized production and application, thus having important economic benefits and obvious social benefits.

Description

technical field [0001] The invention belongs to the field of bioengineering, in particular to a medium-temperature α-amylase high-yield bacterial strain and a construction method thereof. Background technique [0002] α-amylase (α-1,4-glucan-glucanhydrolase EC 3.2.1.1), also known as liquefied amylase, can arbitrarily cut α-1,4 glycosidic bonds from the inside of starch molecules, resulting in relatively small molecular weight of maltodextrin. Under the action of α-amylase, the starch molecules will be degraded rapidly, the viscosity will drop, and the liquefaction will be completed. α-amylase has considerable commercial value and is widely used in starch deep processing industry, alcohol industry, beer industry, citric acid industry, monosodium glutamate and starch saccharification industry, pharmaceutical industry and textile industry. α-amylase can be produced by microbial fermentation, and can also be extracted from plants and animals. At present, most of the industria...

AI Technical Summary

Problems solved by technology

[0009] In recent years, my country's enzyme preparation industry has developed vigorously, and the variety output has also continued to increase, but there is still a gap compared with foreign enzyme preparation industries.

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