Optimization of pullulanase production by Aspergillus flavus under solid-state fermentation

Abstract

Pullulanase is a promising candidate for industrial applications. But less yield and high cost limited its application. Hence, the present study aims to optimize nutrients for increasing the yield of fungal pullulanase to resolve these limitations. The findings of Plackett Burman Design showed that only 5 of 19 nutrients influenced the yield of pullulanase significantly. Box-Behnken Design (BBD) was implemented to establish the optimal concentration of the significant nutrients. After statistical optimization for KH2PO4, yeast extract, peptone, and MnSO4, supplemented in the substrate wheat bran, the overall increase in yield was 1.63 fold. In all the flasks (500 to 5000 mL capacity containing 10–100 g dry substrate), almost the same yield has been produced (647.00 ± 25.139 U/gds) suggesting that the production of pullulanase can readily be scaled up under optimized conditions. This is the first nutrient optimization study of pullulanase production by Aspergillus flavus in solid state fermentation using wheat bran.