Effect of Divalent Metal Ions on Glucoamylase Activity of Glucoamylase Isolated from Aspergillus niger

Effect of maltose on glucoamylase formation by Aspergillus niger.

Low levels of glucoamylase are produced when Aspergillus niger is grown on sorbitol, but substitution of the latter by glucose, maltose, or starch results in greater formation of glucoamylase as measured by enzymatic activity. Both glucoamylase I and glucoamylase II are formed in a yeast extract medium; however, glucoamylase I appears to be the only form produced when ammonium chloride is the n...

Structure of the catalytic domain of glucoamylase from Aspergillus niger.

Glucoamylase from Aspergillus niger is an industrially important biocatalyst that is utilized in the mass production of glucose from raw starch or soluble oligosaccharides. The G1 isoform consists of a catalytic domain and a starch-binding domain connected by a heavily glycosylated linker region. The amino-terminal catalytic domain of the G1 isoform generated by subtilisin cleavage has been cry...

Directed evolution of Aspergillus niger glucoamylase to increase thermostability

Using directed evolution and site-directed mutagenesis, we have isolated a highly thermostable variant of Aspergillus niger glucoamylase (GA), designated CR2-1. CR2-1 includes the previously described mutations Asn20Cys and Ala27Cys (forming a new disulfide bond), Ser30Pro, Thr62Ala, Ser119Pro, Gly137Ala, Thr290Ala, His391Tyr and Ser436Pro. In addition, CR2-1 includes several new putative therm...

Kinetic patterns of glucoamylase isozymes isolated from Aspergillus species.

Production of Glucoamylase by Aspergillus Niger under Solid State Fermentation

In this study, Glucoamylase production by Aspergillus niger was investigated under solid state fermentation using low cost by-products of agricultural processes as substrate. Highest enzyme production was observed when a combination of wheat bran (WB) and corn flour (CF) was used as compared to WB+ rice bran, WB+ rice flour and WB alone. Several compositions of corn flours were experimented. Th...