Abstract

CELLULASE PRODUCTION AND OPTIMIZATION OF PROCESS PARAMETERS BY ONE FACTOR AT A TIME TECHNIQUE FROM MUTANT STRAIN OF BACILLUS STRATOSPHERICUS N12 (M) AND ITS SCALE UP IN A STIRRED TANK BIOREACTOR

Nisha Sharma* and Nivedita Sharma

ABSTRACT

In the present study, enhanced production of cellulase by a stable ethidium bromide treated mutant strain of Bacillus stratosphericus N12 (M) by optimizing various process parameters using one factor at a time (OFAT) technique and scale up in a stirred tank bioreactor has been done. The ethidium bromide mutated strain of B. stratosphericus N12 (M) has shown an increased cellulase production over the wild type strain of B. stratosphericus N12 (W). A good stability until 8 generations has also been observed. Optimization of process parameters by OFAT for enhanced enzyme production yielded 5.983 IU of enzyme on PYC medium at 8.0 pH with 10.0% inoculum following 72 h of incubation time. Further scale up of enzyme production in a 7.5 L stirred tank bioreactor, utilizing the optimized conditions yielded 2.443 IU after 8 h of fermentation thus proving the efficiency of a stirred tank bioreactor in enzyme production with higher volumes in short time.

Keywords: Bacillus stratosphericus, cellulase, mutation, ethidium bromide, bioreactor.