Simultaneous delignification and saccharification of rice straw as a lignocellulosic biomass by immobilized Thrichoderma viride sp. to enhance enzymatic sugar production

Simultaneous biological delignification and saccharification of rice straw by the immobilized Trichoderma viride cells were studied in this work. Response surface methodology as a multiple responses optimization technique was utilized to optimize several important factors such as the biomass content of the medium (w/v), inoculum size and agitation rate. Results indicated that at the obtained optimum conditions the lignin removal efficiency of 74% and sugar concentration equal to 8.52 g/L could be achieved in ten days of pretreatment. In addition, the influence of initial glucose concentration in the medium on both the pretreatment saccharification and the subsequent enzymatic hydrolysis efficiencies was investigated. It was revealed that the higher initial glucose concentration is beneficial to obtain higher total saccharification efficiency from pretreatment and the following enzymatic hydrolysis and a total efficiency equal to 81% was obtained for 15 g/L initial glucose concentration. Accordingly, it can be concluded that the immobilized Trichoderma viride in this work can be considered as a potentially applicable strain to design a promising lignocellulosic materials bio-pretreatment process.