Bacillus licheniformis high-temperature alpha-amylase mutant and application thereof

Abstract

Provided are a bacillus licheniformis high-temperature alpha-amylase mutant and application thereof.A nucleotide sequence of the high-temperature alpha-amylase mutant is shown as SEQ ID NO.1, and an amino acid sequence of the high-temperature alpha-amylase mutant is shown as SEQ ID NO.2.The mutant is obtained by conducting protein engineering improvement and selection on high-temperature alpha-amylase from bacillus licheniformis, the glucose content in a product of hydrolyzed starch can be improved and the dextrin and oligosaccharide content can be reduced by applying mutant enzyme in the hydrolyzed starch, the glucose content in syrup obtained through separate starch hydrolysis is 72%, the using amount of saccharifying enzyme in the follow-up further glucose production can be decreased, and reduction of the production costs is promoted.

Description

technical field [0001] The invention relates to the fields of enzyme engineering and genetic engineering, in particular to a bacillus licheniformis high-temperature alpha-amylase mutant. Background technique [0002] Bacillus licheniformis (Bacillus licheniformis) high temperature-resistant α-amylase BLA has high temperature resistance and high activity, and can randomly hydrolyze starch, glycogen and the α-1.4 glucoside key in the interior of its degradation products to make the viscosity of gelatinous starch solution drop rapidly. The instantaneous temperature in the liquefaction process reaches 105-110°C, and the starch can still be effectively hydrolyzed and the liquefied syrup obtained from the liquefied starch is of high quality, which is widely used in the starch liquefaction process of food fermentation industries such as alcohol, beer, organic acid and starch sugar. , and is currently the most widely used high-temperature α-amylase. But its disadvantages are also o...

AI Technical Summary

Problems solved by technology

Since the main components of the syrup obtained by liquefying starch with high temperature resistant α-amylase are dextrin and oligosaccharides, and the glucose content is usually only 30%. A large number of saccharification enzymes and prolonging the saccharification time can obtain high-conversion glucose syrup, which increases the production cost and reduces the benefit

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