초록
<P><I>Bacillus licheniformis</I> TSI‐14 was isolated form a natural hot water reservoir of TulsiShyam in the Gir Forest, Gujarat (India). The bacterium was identified by 16S rDNA gene sequencing. Amylase production was optimized using an RSM approach (Response Surface Methodology; variables: temperature, pH, medium yeast extract and peptone, and incubation period). These data were refined using Central Composite Design (CCD). The conditions deduced for the maximal α‐amylase production were 50°C, pH 7.0, and incubation times of 2 days. A 4.6 fold increase in α‐amylase was achieved. The molecular weight of the purified enzyme is 31 KDa by SDS‐PAGE. It is active at elevated temperatures such as 90°C, and it prefers pH values around neutral. Optimum catalysis and stability occurred at 70°C and pH 7. There is a strong Mg<SUP>++</SUP> dependency evident; other metal ions show inhibition to a lesser or greater extent. The chelator EDTA completely inhibits while inhibitors urea and beta‐mercaptoethanol show inhibition to a greater extent; thiourea enhances activity. Malto–oligosaccharides are intermediate products along with maltose as expected of a α‐amylase.</P>