Cloning，Experssion and Characterization of Alkali-Stable β-Glucosidase from Bacillus altitudinis SYBC hb4

Abstract:

In order to obtain alkali-stable β-glucosidase and study its enzyme characterization，an alkali-stable strain Bacillus altitudinis SYBC hb4 was screened and isolated from native honey. Based on the β-glucosidasecoding sequences from Bacillus altitudinis SYBC hb4，design up and downstream oligonucleotide primers were designed，and the target gene（bglA） was amplified by using PCR.The expression vector pColdII-bglA was constructed by subcloning the target gene into plasmid pColdII，and then transformed into E. coli BL21（DE3）for heterogeneous expression.The expression β-glucosidase acticity reached to 12.40 U/mL. The optimum temperature and pH of the recombinant β-glucosidase were 60 ℃ and 8.0，respectively. And 5mmol/L Mg2+ could increased 50% β-glucosidase activity.