Analyses using Cell Wall Glycan-directed Monoclonal Antibodies Reveal Xylan-degradation by Two Microbial Glycosyl Hydrolases in Cell Walls from Poplar and Switchgrass Biomass

Plant biomass is considered as an important renewable resource for future bioenergy needs. Cell walls, which are typically highly recalcitrant, constitute the major part of this biomass. Overcoming the cell wall recalcitrance is considered as a major bottleneck towards achieving a highly sustainable and cost-effective production of biofuels from ligno-cellulosic materials [1]. Cell wall components, such as lignin and hemicelluloses, have been documented to contribute to cell wall recalcitrance [1,2]. In plant biomass, removal or reduction in the proportions of xylans, a major hemicellulose component of secondary wall-rich biomass, and that of lignin results in a significant reduction in cell wall recalcitrance [3,4]. This is because a reduction in xylan and lignin, in general, is thought to result in an increased exposure of cellulose microfibrils to subsequent microbial/enzymatic conversions [1]. Hence, any success in the generation of biomass raw materials with reduced amounts of hemicellulosic components, particularly xylan, could potentially be of high importance to efficient biofuel production from plant biomass. Such modifications are also important for other plant biomass-based bio-refinery applications, such as production of various value-added products including biochemical and biopolymers.