Expression and secretion of barley alpha-amylase and A.niger glucoamylase inSaccharomyces cerevisiae.
cDNAs of barley alpha-amylase andA. niger glucoamylase were cloned in oneE. coli-yeast shuttle plasmid resulting in the construction of expression secretion vector pMAG15. pMAG15 was transformed intoS. cerevisiae GRF18 by protoplast transformation. The barley alpha-amylase andA. niger glucoamylase were efficiently expressed under the control of promoter and terminator of yeast PGK gene and their own signal sequence. Over 99% of the enzyme activity expressed was secreted to the medium. The recombinant yeast strain, S.cerevisiae GRF18 (pMAG15), hydrolyzes 99% of the starch in YPS medium containing 15% starch in 47 h. The glucose produced can be used for the production of ethanol.
Luo
J
J
Department of Biochemistry and Biotech-Research Center, Zhongshan University, 510275, Guangzhou, China.
Li
Z
Z
Li
W
W