Optimization of Cultivation Conditions for Protease Production from Marine Bacteria by Response Surface Methodology

Minitab 16 software was applied to optimize the conditions for protease production of marine bacteria SE2011.On the basis of single factor experiments,the Plackett-Burman design was utilized to analyze effect factors.Among the eight factors studied,salinity,pH value and volume of medium per flask had significant effects on protease production(P0.05).The path of steepest ascent was undertaken to approach the optimal region of the protease production.The regression analysis was further investigated by using Box-Behnken design and response surface analysis.By solving regession equation,the highest protease production was obtained at salinity 2.0%,pH 8.0 and volume of medium 23 ml per flask.The protease production reached to 1336.462 U/ml,which increased 82.3% compared to the initial 733.269 U/ml.