Production of Industry-Viable Thermo-Amylase from <i>Geobacillus stearothermophilus</i> KTRAM Using Agricultural By-Product as a Substrate

Herein, a thermophilic Geobacillus stearothermophilus strain KTRAM was studied for optimization parameters for amylase production. Among the four isolates screened, only isolate T2 was positive for amylase production. T2 has a maximum homology to the other G. stearothermophilus with similar growth and tolerability indices. Qualitative enzyme assays showed both amylase and lipase activities in starch, and olive oil/rhodamine B media, respectively. In later steps, the optimization of amylase was carried out using an agricultural by-product rice bran as a substrate, supplemented with other carbon and nitrogen sources. With the varying stimulatory effects, optimum production was achieved at 55°C and pH 7.5 between 48 and 72 hours. The partially purified enzyme was found to have a molecular weight of ∼55 kDa, which is in contrast to related Geobacillus amylases. Besides, G. stearothermophilus KTRAM can grow even up to 70°C and produces various other thermozymes, manifesting its role in critical industrial bioprocess.