Abstract
•Fenton pretreatment effectively destroyed the resistant structure of rice straw.•The recalcitrant lignin was effectively degraded by 15.01%.•The activities of ligninolytic enzymes were enormously enhanced after pretreatment.•GC–MS analysis gave further insight into the degradation of Fenton pretreatment.
The rice straw (RS) is a kind of recalcitrant lignocellulosic material. The Fenton reaction has been widely used for the degradation of organic compounds and toxic chemicals. Therefore, applying it to pretreatment straw seems to have good potential. This study was to investigate the degradation of the pretreated RS by the mixed solid-state culture with Phanerochaete chrysosporium and Aspergillus nigert. The results showed that the degree of delignifition was 15.01% by using an optimized Fenton reagent (6 g/L of FeSO4·7H2O and 15% concentration of H2O2) at a solids loading of 5% (w/v) and a moderate temperature for 15 h. The analysis of the Fenton pretreated RS by Scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FTIR) showed significant changes in physicochemical structure, favoring the subsequently susceptibility of ligninolytic enzymes. The volatile organic compounds collected from the mixed solid-state culture implied the degradation degree of the lignocellulose to some extent. In conclusion, Fenton pretreatment could effectively disrupt the recalcitrant structure of RS and accelerate its biodegradation, which has high potential application in the energy conversion and utilization of lignocellulose.