CHARACTERIZATION AND STABILITY OF EXTRACELLULAR ALKALINE PROTEASES FROM HALOPHILIC AND ALKALIPHILIC BACTERIA ISOLATED FROM SALINE HABITAT OF LONAR SODA LAKE, INDIAAbstract
Culture dependent phenotypic characterization analyses were applied to study the protease producing bacteria from Indian Soda (Lonar crater). The uniqueness of the Lonar lake water is its salinity and alkalinity. A total of one hundred and fourteen bacterial cultures were isolated from the water and sediment samples collected from the hyper alkaline saline environment of Lonar lake. The thirty two bacterial strains were found protease producing bacterial culture, out of them strain EW2 was selected for 16S rDNA sequencing, production and partial characterizations of protease on the basis of their maximum proteolytic activity. The phylogenetic position indicated the strain was related to phylum Firmicutes. Optimum enzyme activity was found to be at 80 °C and pH 9.5. The protease was highly stable over broad temperature from 40 to 90 °C, pH 7.0 – 12.0, showing excellent thermostablity and alkaline tolerant nature. The enzyme activity has enhanced by all metal ion which was tested in this studies indicating it was a metalloenzyme but inhibited by organic solvent except acetone. This is valuable information for enzyme production and optimization of protease from Bacillus pumilus EW2 has bright future towards the improvement and production of novel enzymes for leather, detergent and pharmaceuticals industries and biotechnological potential.