|
KMID : 0545120150250060828
|
|
Journal of Microbiology and Biotechnology
2015 Volume.25 No. 6 p.828 ~ p.836
|
|
|
Screening, Gene Cloning, and Characterizations of an Acid-Stable α-Amylase
|
|
Xinyu Liu
Wei Jia
Yi An
Kun Cheng
Mingdao Wang
Sen Yang
Hongge Chen
|
|
|
Abstract
|
|
|
|
Based on its α-amylase activity at pH 5.0 and optimal pH of the crude enzyme, a strain (named B-5) with acid α-amylase production was screened. The B-5 strain was identified as Bacillus amyloliquefaciens through morphological, physiological, and biochemical characteristics analysis, as well as 16S rDNA phylogenetic analysis. Its α-amylase gene of GenBank Accession No. GU318401 was cloned and expressed in Escherichia coli. The purified recombinant α-amylase AMY-Ba showed the optimal pH of 5.0, and was stable at a pH range of 4.0-6.0. When hydrolyzing soluble starch, amylose, and amylopectin, AMY-Ba released glucose and maltose as major end products. The α-amylase AMY-Ba in this work was a different type from the well-investigated J01542 (GenBank Accession No.)-type α-amylase from the same species. AMY-Ba exhibited notable adsorption and hydrolysis ability towards various raw starches. Structure analysis of AMY-Ba suggested the presence of a new starch-binding domain at its C-terminal region.
|
|
|
KEYWORD
|
|
|
α-amylase, Bacillus amyloliquefaciens, raw starch, starch-binding domain
|
|
|
FullTexts / Linksout information
|
|
|
|
|
|
Listed journal information
|
|
  
|
|