Abstract

Microwave-assisted FeCl₃ pretreated rice straw was degraded to reducing sugars withTrichoderma 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. pumilusinoculum 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.

Key words: Microwave-assisted FeCl₃ pretreated rice straw, Trichoderma viride, Bacillus pumilus, degradation conditions, response surface methodology (RSM) optimization.