Improving α-amylase production by Bacillus licheniformis ATCC 6346 with local nitrogen sources and amino acids supplementations

Microbial α-amylase is highly demanded industrial enzyme in various sectors such as pharmaceuticals, food, textile and detergents, etc. In this study production of α-amylase by Bacillus licheniformis ATCC 6346 was investigated with locally available nitrogen sources such as mustard, sesamum and coconut seed cake powders instead of peptone (6 gL-1). The highest α- amylase activity (32.95 UmL-1) was produced in the medium containing mustard powder while negligible amount (0.69 UmL-1) was obtained in the medium with coconut seed cake powder. Among the defatted local nitrogen sources, highest α-amylase activity (58.14 UmL-1) was produced in the medium with defatted mustard seed cake powder (18 gL-1) and least activity (29.61 UmL-1) was produced in presence of defatted coconut seed cake powder (24 gL-1). Sesamum seed cake powder (18 gL-1) and coconut seed cake powder (24 gL-1) containing media were supplemented with different amino acids or their mixture equivalent to the present in mustard seed cake (18 gL-1) powder. Supplementation of 0.0147 and 0.10801 gL-1 tryptophane respectively to defatted sesamum (18 gL-1) and coconut seed cake powder (24 gL-1) containing media increased the production of α-amylase to 57.42 and 58.26 UmL-1, which were almost equalent to that produced in defatted mustard seed cake powder.