Optimization of medium composition for thermostable protease production by Bacillus sp . HS08 with a statistical method

Abstract

4fullfactorial central composite design (CCD) was chosen to explain the combined effects of the four medium constituents; corn starch, soybean meal, glucose and yeast extract. The optimized values obtained by the statistical analysis showed that corn starch at 19.8 g/l, soybean meal at 9.7 g/l, glucose at 3.6 g/l and yeast extract at 3.9 g/l gived maximum protease activity of 6804 U/ml.