Journal of Pure and Applied MicrobiologyVol. 9 No. 1

Optimized Alkaline Protease Production by Bacillus thuringiensis

Misha V. Patel*, Prateek Shilpkar and Arvind Dungrechia

Biogas Research Centre and Post Graduate Department of Microbiology, Gujarat Vidyapeeth, Sadra 382 320, Gandhinagar, Gujarat, India.

Received on 15 November 2014 and accepted on 21 December 2014



In a laboratory study 18 different types of bacteria were isolated from soil showing protease production in 1% casein agar medium. After screening, one potent bacterial culture was identified as Bacillus thuringiensis and its protease production was further optimized for various fermentation conditions. Results show that the culture gives maximum alkaline protease production under optimum condition of pH- 11.5 (40.7 U/mL), temperature- 25?C (60.13 U/mL), substrate concentration- 3% (33.54 U/mL) inoculum size - 1mL (v/v) with optimum activity 60.13 U/mL, incubation time- 24 hr (60.13 U/mL), 0.30% beef extract as nitrogen source (61.23 U/mL), and 1% lactose as carbon source (37.77 U/mL).

Keywords : Bacillus thuringiensis, alkaline protease, pods of Cassia fistula.