Translated Title
Cloning, expression and characterization of the thermostable alpha-amylase gene from Geobacillus sp.WQJ-1 isolated from hot springs
Translated Abstract
The amy WQJ gene encoding alpha-amylase from Geobacillus sp.WQJ-1 was amplified by PCR,and linked with vector pET-28a (+).The constructed recombinant plasmid pET-28a (+)-amyWQJ was transformed into E.coli BL21 (DE3),and the recombinant protein was obtained via induction of expression and purified by nickel affinity chromatography,the purified enzyme presented as one protein band on SDS-PAGE with molecular weight of 59 ku.The study showed that the optimum pH value was 6.0,and it has good pH stability,optimum temperature of purified alpha-amylase was 70 ℃C.Ca2+can significantly improve the thermostability of the enzyme.The activity of the enzyme was inhibited by Hg2+,EDTA,SDS,Cr3+,Mn2+,Cu2+ and Pb2+in different degrees,and activated by Co2+,Na+andβ-Mercaptoethanol.By using starch soluble as substrate,the Km was 6.62 mg · mL-1 and vmax was 2 197.80 μmol · (mg · min)-1.Oligosaccharide is the final product of enzymatic hydrolysis of Starch cassava.
Translated Keyword
alpha-amylase
characterization
cloning
expression
Geobacillus
Access Number
WF:perioarticalfzdxxb201801023
