Serratia marcescens B4A chitinase product optimization using Taguchi approach

Document Type: Research Paper

Authors

1 Department of Animal and Marine Biotechnology, National Institute of Genetic Engineering and Biotechnology (NIGEB), P.O. Box 14965/161, Tehran, I.R. Iran.

2 Faculty of Marine Sciences, Khorramshahr Marine Sciences and Technology University, P.O. Box 669, Khorramshahr, I.R. Iran.

3 Iranian Fisheries Research Organization, P.O. Box 14155/6116, Tehran, I.R. Iran.

Abstract

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 30ºC, pH 7.9, NaCl 0.1% (w/v) and chitin 1% (w/v) are optimal conditions for this protocol.

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