Medium Formulation and its Optimization to Enhance Protease Production by Streptomyces sp. Isolated from Mangroves

Abstract

Streptomyces sp. LCJ12A was isolated from the soil and sediments of Pichavaram Mangrove Forest, Tamil Nadu, India. Production of protease from the Streptomyces sp. LCJ12A was carried out by using submerged fermentation. To enhance the protease production, the fermentation medium was formulated and optimized. Different carbon, nitrogen and inducer sources were used for the optimization. In that fructose, sodium nitrate and red gram husk showed greater quantity of protease production and their different concentrations were optimized in Protease production broth (PPB). Response surface methodology (RSM) was employed for the medium optimization at a low cost for the production of industrially important enzyme. The optimized values showed that fructose at 2.0 g/L enhances the yield of protease up to 120.08±2.2 U/mL, sodium nitrate at 2.0 g/L maximize the protease production up to 180.35±1.9 U/mL and red gram husk at 2.0 g/L yields 194.16±2.2 U/mL which was 1.6 times higher when compared to the unoptimized medium. Statistical optimization by using RSM predicted that 327.16 U/mL of protease enzyme can be produced. Through experimentation based on RSM, the protease yield reached up to 323.4 U/mL. When compared to unoptimized medium, the statistically optimized medium produced 3 times higher yield. As a result of the optimization studies, an increase in protease activity was reached compared to the unoptimized conditions and thus offers a new approach for industrial enzyme production.