Biosynthesis of glucoamylase from Aspergillus niger by solid-state fermentation using tea waste as the basis of a solid substrate

Tea waste, supplemented with minerals, was used as the solid substrate for the synthesis of glucoamylase by a strain of Aspergillus niger NCIM 1248. Maximum glucoamylase synthesis [198.4 IU/g dry substrate (gds)] was obtained on the mineralised tea waste at 96 h with an inoculum, initial moisture and pH of 4%, 60% and 4.5, respectively at 30°C. Among different carbon sources, sucrose favoured the increase of glucoamylase synthesis (212.6 IU/gds) in 96 h, whereas among different nitrogen sources, malt extract gave the highest enzyme titre (226.0 IU/gds) at 72 h.