OPTIMIZATION OF THE PRODUCTION AND PARTIAL CHARACTERIZATION OF AN EXTRACELLULAR ALKALINE PROTEASE FROM THERMO-HALO-ALKALOPHILIC LONAR LAKE BACTERIA

LONAR Lake, an impact crater located in the Buldhana district of Maharashtra State, India is occupied by saline water and harbors various unidentified, unique haloalkaliphilic bacterial bacillus species which produces thermo-halo-alkaliphilic proteases. The present study deals with the isolation, production dynamics, purification, characterization and optimization of a protease from Bacillus pseudofirmus, Cohnella thermotolerans and Bacillus odysseyi isolated and identified by 16S rRNA ribotyping from the Alkaline Lonar Lake. The Bacillus pseudofirmus, Cohnella thermotolerans and Bacillus odysseyi produced protease at maximum rate after 72 h of incubation at 370C with agitation speed of 120 rpm and 5% of starter culture. The best carbon sources for this Bacillus pseudofirmus, Cohnella thermotolerans and Bacillus odysseyi were fructose, maltose, starch and lactose respectively where as the best nitrogen sources were yeast extract, soy tone and soyabean cake respectively. While the most effective inorganic nitrogen sources was ammonium carbonate for Bacillus pseudofirmus, Cohnella thermotolerans and urea for Bacillus odysseyi. Supplementation of the culture medium with amino acid L-glutamic acid for Bacillus pseudofirmus and L-glycine for Cohnella thermotolerans and Bacillus odysseyi and metal ion Mg2+ for all the three bacillus species improved the protease production substantially. Under these conditions, newly isolated Bacillus pseudofirmus, Cohnella thermotolerans and Bacillus odysseyi strain were found to produce alkaline proteases at a maximum rate of optimum pH 10 and temperature at 750C.