A solid state fermentation based bacterial α-amylase and fungal glucoamylase system and its suitability for the hydrolysis of wheat starch

Abstract

Laboratory isolates of Bacillus sp. AS-1 and Aspergillus sp. AS-2, produced very high titers of thermostable α-amylase (198 950 U/g fermented dry matter) and glucoamylase (3426 U/g fermented dry matter), respectively, during solid state fermentation of wheat bran. Both enzymes were active and stable over a wide range of temperature and pH. α-Amylase exhibited a high liquefying efficiency of 96% while glucoamylase revealed a high saccharification efficiency of 87%, in a 15% starch solution, at 50 °C. When used in combination, these enzymes could effectively hydrolyze wheat mash revealing a maximum conversion efficiency of 96%.