Effect of salt and pH on the growth and production of alkaline proteases from Haloalkaliphilic bacteria isolated from saline desert

Abstract

Saline desert of Kutch is yet unexplored for its microbial diversity and biotechnological potential. Proteases are significant with respect to their applications and cellular roles. A total of 15 bacteria isolated from the Little Rann of Kutch were isolated and screened for their growth and protease secretion at different pH and salt concentrations. Effect of NaCl concentrations and pH was assessed on growth and production of the proteases. Overall, 50 % of the isolates grew in the range of 0-20 % (w/v) NaCl, while nearly 45 % of them optimally produced extracellular proteases at 10 % (w/v) NaCl and 20 % isolates produced protease optimally at 15% (w/v) NaCl concentration. Majority of the isolates secreted protease in pH range 7-11 and nearly 70 % the isolates produced enzyme in the broad range of pH, 7-11 and nearly 6 % isolates produced protease in the range of pH 9-11. Further, around 40% of the isolates produced proteases optimally at pH 9-11. Therefore, the isolates demonstrated a broad range of pH and salt for growth and protease production. The study suggests wide prospective of the applications of these organisms and their enzymes