Expression and secretion of barley alpha-amylase and A.niger glucoamylase inSaccharomyces cerevisiae

Sci China C Life Sci. 1998 Apr;41(2):113-8. doi: 10.1007/BF02882714.

Abstract

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.