A Surfactant, Oxidant and Inhibitor Compatible Thermo-solvent-tolerant Amylase From a Novel Extrimophilic Bacillus Subtilis Strain Clb-34 Mk443366: Study on Purification and Characterization

It is the first time when thermo-tolerant, heavy metal resistance amylase producing strain Bacillus subtilis isolated from soil sample. Amylase was purified 3.8-fold with a specific activity of 11,305.0 U mg -1 . The molecular weight of purified amylase was 67 kDa as revealed by SDS-PAGE and activity gel analysis. The amylase was active in broad pH and temperature range of 4.0-11.0 and 35-110°C, respectively, with maxima at pH 7.0 and 85°C temperature. The amylase has Km and Vmax value of 2.181 mg ml -1 and 909.09 µg ml -1 min -1 , respectively when starch used as substrate. The amylase was not only stable but also its activity enhanced in the presence of n-dodecane, iso-octane, n-decane, xylene, toluene, n-butanol, acetone, and cyclohexane, after prolonged incubation (7 days). Amylase activity and stability was inhibited in the presence of Hg 2+ , benzene, sodium perborate. The unique property of solvent tolerance and heavy metal resistance proves the potential candidature of this isolate not only for starch liquefaction for food application but also for bioremediation strategies involved in environmental cleanup.