Development of a solid-state fermentation process for production of bacterial α-Amylase from agro-byproducts and its optimization

Solid-state fermentation (SSF) was carried out using different agro-byproducts as substrate for the production of α-amylase using a bacterial culture of Bacillus licheniformis. Among all the substrates wheat bran supported maximum growth and produced maximum alpha amylase (154.17 IU) under Triton –X as extraction medium. Production optimization was conducted using wheat bran. The maximum alpha amylase production was obtained at pH 6 (170.34 IU) 40°C (168.78 IU), 48 h (155.06 IU) and with 80% initial moisture (171.89 IU). Supplementation with 1% maltose further enhanced enzyme yield (178.46 IU). However, glucose and lactose inhibited the enzyme production. Increase in the enzyme yield (171.68 IU and 172.36 IU) was obtained when fermentation medium was supplemented with 1% soy peptone and (0.15 M) ammonium chloride, respectively. Addition of 0.01 M phosphate concentration also enhanced amylase production. Therefore, from the present study it can be concluded that starch digesting α- amylase produced by Bacillus licheniformis in solid state fermentation could be important in biotechnological application.