Screening of the Nutrient Parameters for Protease Production by Bacillus cereus Using Plackett-Burman Design under Submerged Fermentation

Abstract

Plackett-Burman experimental design was used to screen important nutrient parameters influencing the production of protease by Bacillus cereus, which was isolated from fish waste soil. The Plackett-Burman design is orthogonal in nature and it is a set of small and efficient experiments, which are very powerful in biotechnology research and development. Screening of 11 factors was done in 12 experiments. The 11 factors included one process parameter (initial pH of medium), two inoculum conditions (inoculum age and inoculum volume), five medium constituents (yeast extract, ammonium sulphate, maltose, peptone and MgSO₄) along with three dummy variables. From standard Plackett-Burman data analysis, it was confirmed that pH, maltose and peptone had contributed to a large extent while inoculum age, MgSO₄ and yeast extract contributed moderately for protease production by B. cereus under submerged fermentation.