Optimal conditions for maximizing production of reducing sugars from microwave-assisted FeCl3 pretreated rice straw degraded by Trichoderma viride and Bacillus pumilus

Abstract

Microwave-assisted FeCl₃ pretreated rice straw was degraded to reducing sugars with Trichoderma viride and Bacillus pumilus. Response surface methodology (RSM) and Box-Behnken design (BBD) were used to optimize degradation conditions of pretreated rice straw with respect to initial pH, degradation temperature, T. viride/B. pumilus inoculum ratio (T/B inoculum ratio) and degradation time to achieve the highest production of reducing sugars. The maximum production of reducing sugars obtained was 7.19 g/L at the optimal conditions of initial pH, 8; degradation temperature, 32°C; T/B inoculum ratio, 3 ml/1 ml; degradation time, 60 h. This optimization strategy enhanced the production of reducing sugars from 6.62 to 7.19 g/L after optimization, which shows the beneficial effect on optimization of degradation conditions.