Effects of synergistic fungal pretreatment on structure and thermal properties of lignin from corncob.

Synergistic fungal pretreatment involving white-rot and brown-rot fugal pretreatment has shown great potential for enhancing the yield of sugars from biomass time-effectively and environmentally benign. In this work, the effects of this integrated fungal pretreatment on lignin characteristics and thermal behavior of corncob were examined in the view of whole plant valorization. The results show that an efficient deconstruction of lignin was achieved by white-rot fungus, and subsequent brown-rot fungus promoted the preferential breakdown of guaiacyl units, further enhancing lignin extraction efficiency (62.3%). Consequently, less phenolic hydroxyl, methoxyl, tricin, ester-linked p-coumaric acid, more carboxylic acid, ratio of syringyl to guaiacyl units, β-O-4' linkage and molecular weight were found in W-BL. Thermal stability was improved and the increased phenol and alkyl-phenols contents in pyrolysis products demonstrated that synergistic fungal pretreatment definitely improved the lignin oil quality. These discoveries provide new insights into set strategy for microbial screening, pretreatment and lignin processing.