Partial characterization and optimization of alkali ne amylase production from Bacillus lehensis isolated from alkaline saline Lonar Lake

A Gram positive bacterium isolated from a water sample from the alkaline saline Lonar Lake. It was identified as Bacillus lehensis BW3(2) by morphological, biochemical characterization and 16S rDNA sequencing. The bacterium grew in sodium chloride (NaCl w/v ) from 0.5 to 7% and at pH 7‐ 12. A substantial level of extracellular alkaline amyla se was produced by Bacillus lehensis BW3(2). Optimum enzyme activity was found to be at 80°C, pH 10.0, and 2% NaCl. The amylase was highly stable over broad temperature from 40 to 100°C, pH 6.0-12.0, and NaCl concentration 0.5-10% ranges, showing excellent thermostablity, and haloa lkaline tolerant nature. A Lineweaver-Burk plot indicates that enzyme has a Km of 6.66 mg of starch per mL and a Vmax of 55.55 mg of maltose per mL/ min. The enzyme activity has enhanced by BaCl 2 but highly inhibited by KCl, indicating it was a metalloenzyme. Among the organic nitrogen sources, optimum growth and amylase production were supported by the combination of peptone and yeast extract. This is a valuable information for enzyme production and optimization of amylase from Bacillus lehensis BW3(2) has bright future towards the improvement and production of novel enzymes for entirely new areas of industrial and biotechnological applications.