Biofuels Production from Organosolv Treated Lignocellulose:\nNondetoxified Fermentation and Microbial Community Analysis

Wastewater\ngeneration has been a universal problem during the detoxification\nprocess of pretreated residue. To break the recalcitrant structure\nof sugar cane bagasse and minimize wastewater generation, biocompatible\ntriethylene glycol (TEG) solvent was used for pretreatment and enabled\nthe bioethanol and/or biomethane production from nondetoxified sugar\ncane bagasse (NDSCB). The yield of ethanol from NDSCB was 62.45% (P-I).\nCompared to the methane production process (P-II), a fast start-up\nand 2946 mL of methane were obtained from ∼2.50 g of volatile\nsolids NDSCB during the ethanol–methane coproduction process\n(P-III), while that of P-II is 2618 mL. The material flow indicates\nthat nondetoxified fermentation is suitable for methane production.\nMoreover, the P-III process changed the distribution of the bacterial\nand methanogenic communities as <i>Syntrophotalea</i> and <i>Methanobacterium</i> were dominant. The possible reason for\nthe longer lag phase in P-II might stem from the rivalry between <i>Mestoga</i> and acetoclastic methanogens in acetate usage. This\nstudy introduces environmentally friendly biofuel processes for the\nvalorization of lignocellulose.