OPTIMIZATION OF PRODUCTION AND PARTIAL CHARACTERIZATION OF ALKALINE PROTEASE BY NEWLY ISOLATED BACILLUS SUBTILIS STRAIN RS2 FROM DESERT SOIL
Shine K, Kanimozhi K, Panneerselvam A, Muthukumar C, Thajuddin N
A bacterial strain RS2 with high proteolytic activity was isolated from desert soil samples of Riyadh, Saudi Arabia. The strain was identified as Bacillus subtilis by morphological and biochemical characteristics as well as by 16S rRNA gene sequence analysis. Process parameters influencing the maximum production of extracellular alkaline protease by Bacillus subtilis strain RS2 were optimized using one factor constant at a time method along with its characterization. The maximum level of alkaline protease enzyme production was obtained when the incubation temperature was 400 C in growth medium of pH 9 with 2% inoculum and continuous agitation at 140 rpm for 48 hours. The Bacillus subtilis strain RS2 utilized several carbon sources for the production of alkaline proteases, lactose was the best carbon source followed by glucose and sucrose. Among the various organic and inorganic nitrogen sources, casein was found to be the best nitrogen source for the maximum production of alkaline protease. The crude alkaline protease enzyme showed maximum activity at pH 9 and temperature 500 C. These findings suggested that the protease enzyme produced by Bacillus subtilis strain RS2 has a potential for industrial applications by its activity at high temperature and high alkaline pH.