Optimization and alphα-amylase production secreted by mutant and wild-type of Bacillus subtilis C5 from cassava effluent in Ile-Ife, Nigeria

The study investigated the production and optimization of α-amylase from both wild-type and chemically induced mutant strains of Bacillus subtilis C5 isolated from cassava effluent in Ile-Ife, Nigeria. Mutagenesis was carried out using ethyl methyl sulfonate (EMS) and ethidium bromide (EtBr), and the mutants were screened on starch agar for hydrolytic efficiency. Screening revealed that strain MttEB6 exhibited the highest amylase activity. The enzyme production was further optimized under submerged fermentation by evaluating the effects of incubation time, temperature, pH, carbon and nitrogen sources, and starch concentration. Optimal conditions for enzyme production were observed at 48 h of incubation, pH 7.0, 45 ˚C, 1.0% starch concentration, with starch and peptone as the best carbon and nitrogen sources, respectively. Under these conditions, mutant MttEB6 produced up to 2.67 times more α-amylase than the wild-type strain. The enhanced production by the mutant strain highlights its industrial potential. This research contributes to microbial enzyme biotechnology by demonstrating the efficacy of mutagenesis in improving enzyme yields.