ISOLATION AND PURIFICATION OF AN EXTRACELLULAR PROTEASE FROM BACILLUS SUBTILIS ASASBT ISOLATED FROM TERMITE SOIL

Proteases are one of the most important enzymes in many industrial applications, particularly as additives in laundry detergent industry. Hence, the present study investigates the isolation and purification of an extracellular protease from the Bacillus subtilis ASASBT isolated from termite soil sample. Among the five protease producers, one of the isolates was selected for further studies.  It was related to Bacillus subtilis on the basis of 16S rRNA gene sequencing and biochemical properties. The maximum protease activity recorded at 48 h of incubation at 37°C was 154.13 U/ml. Based on the maximum activity of the enzyme, further optimization studies were done with Bacillus subtilis ASASBT. Its optima pH and temperature of enzyme production were pH 7.0 and 40 °C, respectively. Starch and gelatin were the best carbon and nitrogen sources for the production of protease. The isolated protease was purified in four steps involving ammonium sulphate precipitation, dialysis, DEAE-Cellulose and sephadex G-100 chromatography had a 4.01 fold increase in specific activity (86.51 U/mg) and 23.73 % increase in recovery percentage. These properties suggest that protease from Bacillus subtilis ASASBT could find potential application in various industries.