Résumé
Chitinase production by newly isolated Serratia marcescens B4A was optimized following Taguchi's array methods. Twenty-three bacterial isolates were screened from shrimp culture ponds in the South of Iran. A chitinase-producing bacterium was isolated based on it's ability to utilize chitin as the sole carbon source. The isolate designated as B4A, was identified as Serratia marcescens based on its 16S rRNA sequence and key morphological, physiological and biochemical characteristics. The cultivation of Serratia marcescens B4A in the appropriate liquid medium resulted in production of high levels of chitinase. The malt extract and colloidal chitin represented the best nitrogen and carbon sources, respectively. Chitinase production by Serratia marcescens B4A was optimized following the Taguchi orthogonal array [OA] for the design of experiments [DOE]. Statistical experimental design via the Taguchi method was applied to determine the optimal levels of physical parameters and key media components in the medium, such as temperature, pH, NaCl and chitin concentrations. The results of this study showed that temperature of 30§C, pH 7.9, NaCl 0.1% [w/v] and chitin 1% [w/v] are optimal conditions for this protocol