Effects of Different Carbon Sources on Activity of Glucoamylase Produced by Aspergillus niger

Choosing soluble starch,glucose,sucrose,maltose,lactose and β-cyclodextrin as carbon sources of A. niger to produce glucoamulase,their effects on the activity of glucoamulase were studied. The results showed that the glucoamylase activity is the highest,reaching 350.34±14.06 U/ml,when soluble starch was used as carbon source,followed by glucose,sucrose and maltose in turn(no significant difference at 0.05 probability level among them) . The glucoamylase activity by lactose is less than that by sucrose or maltose. Almost no glucoamylase is produced when β-cyclodextrin is used as carbon source. The results of mycelia biomass of A. niger showed that A. niger can assimilate starch,glucose,sucrose and maltose apart from β-cyclodextrin.