Optimization Studies for Chitinase Production from Parapeneopsis hardwickii (spear shrimp) exoskeleton by solid-state fermentation with marine isolate Citrobacter freundii str. nov haritD11

The aim of this study was to report traditional and statistical optimization of fermentation conditions for chitinase production by a novel bacterial strain, Citrobacter freundii haritD11 isolated from marine sediment. A sequential optimization methodology comprising of traditional one-variable-at-a-time approach and response surface methodology was applied to enhance the fermentative production of chitinase under solid-state fermentation using shrimp shellfish waste. Maximum chitinase activity (128.47 U/gds) was obtained at basic optimum conditions. To improve the chitinase production activity, chosen parameters were further optimized statistically through Box-Behnken method and the critical levels of the three examined independent variables as predicted from the model are 34.6 degrees C of temperature, 58.19% v/w moisture content and 2.36 % w/w yeast extract concentration. At these conditions, predicted chitinase activity of 141.787 U/gds was observed, a verification experiment was accomplished and the experimental value was 143.15 U/gds at the critical conditions predicted. Statistical optimization showed 1.1-fold of improved chitinase activity compared to traditional one-variable-at-a-time method. Hence fermentation of shrimp waste for chitinase production using Citrobacter showed biodegradation of the chitinous waste and concomitantly the enzyme was reported to have antifungal activity.