The sequential Fenton oxidation and sulfomethylation pretreatment for alleviating the negative effects of lignin in enzymatic saccharification of sugarcane bagasse

The sugarcane bagasse (SCB) was pretreated by the sequential Fenton oxidation and sulfomethylation pretreatment (FSP) for reducing the lignin inhibition in enzymatic saccharification. The FSP showed the delignification of 67.76% and the glucan retention in pretreated solid of 97.81%. Compared with sulfomethylation pretreated SCB (SP-SCB), the lignin surface coverage and surface hydrophobicity of FSP-SCB decreased by 1.84 and 4.84 times, respectively, led to enzymatic accessibility increased by 20%. Using the cellulase loading of 20 FPU/g glucan, the 72 h yields of glucose and xylose were 76.24% and 64.83%, respectively, which was 1.3-2.0 times higher than that of sulfomethylation treated SCB alone. Fenton oxidative reaction as a pre-step will help sulfomethyl group to easily and more introduce on aromatic ring, thereby accelerating the delignification.