Enhancement of fungal delignification of rice straw by Trichoderma viride sp. to improve its saccharification

• Fungal delignification was optimized for important operational factors.
• Effect of wet milling and the presence of surfactant in the system was investigated.
• Biodelignification efficiency increased to 74% at the optimum conditions.
• Efficient saccarification was achieved by low activity enzymatic hydrolysis.

Fungal delignification can be considered as a feasible process to pre-treat lignocellulosic biomass in biofuel production, if its performance is improved in terms of efficiency thorough a few modifications. In this study, Trichoderma viride was utilized to investigate the effect of wet-milling, addition of surfactant (Tween 80) and optimization of operating factors such as temperature, biomass to liquid medium ratio and glucose concentration on biodelignification of rice straw. Next, the enzymatic hydrolysis of pretreated biomass was studied at various pretreatment times. Results revealed that the wet milling and addition of surfactant increases the lignin removal about 15% and 11%, respectively. The optimization of operating factors resulted in high lignin removal efficiency equal to 74% in a 30 day pretreatment. The maximum enzymatic saccharification of pretreated biomass at optimum conditions was obtained equal to 56%. Conversion of cellulose to reducing sugars during the pretreatment stage was 21% which suggests that higher saccharification efficiency could be achieved in a simultaneous pretreatment and saccharification process.