Optimization of medium components for production of chitin deacetylase by Bacillus amyloliquefaciens Z7, using response surface methodology

Plackett-Burman design and Box-Behnken response surface methodology (RSM) was employed to optimize the medium components for the chitin deacetylase (CDA) activity from Bacillus amyloliquefaciens Z7. Plackett-Burman design was applied to determine the specific medium components affecting CDA activity and found that starch, chitin and MgSO₄ were critical in augmenting CDA activity. These significant parameters were further optimized using Box-Behnken RSM and the optimum concentrations of starch, chitin and MgSO₄ were found to be 24.4, 8.8 and 0.19 g/L, respectively. The optimum medium composition was chitin 8.8 g/L, starch 24.4 g/L, yeast extract 10g/L, MgSO₄ 0.19 g/L, K₂HPO₄ 0.3 g/L and NaCl 5 g/L. Under these optimal conditions, the CDA activity of Bacillus amyloliquefaciens Z7 increased distinctly from 18.75 to 27.48 U/mL (46.6% increase in total yield).