(714a) Insights of Biomass Recalcitrance in Populus for Biomass Valorization

For the effective utilization of biomass, understanding of its properties, in particular, biomass recalcitrance-related properties is essential. Diverse approaches are applicable to reveal the secret of biomass recalcitrance. Among many, physicochemical characteristics of biomass feedstock do not only elucidate the biomass recalcitrance, but also provide clues to overcome its physical and chemical barriers for biomass conversion. Transcriptome analysis also gives important overview about transcriptional regulation network of biomass synthesis related gene families. Populus has been investigated as a promising biomass feedstock for alternative fuels and chemicals. However, biomass recalcitrance-related properties and their causable variation of gene expression are not sufficiently understood. Here, recalcitrance of Populus natural variants was elucidated in three aspects: (1) fermentable sugar release, (2) physicochemical properties of biomass, and (3) relative variation of gene expression. Sugar release and physicochemical characteristics of Populus natural variants including chemical composition, cellulose and lignin’s molecular weights/degree of polymerization, cellulose crystallinity, lignin composition, and cellulose accessibility were measured by diverse analytical methods such as HPLC, GPC, 2D ¹³C-¹H HSQC NMR, solid-state NMR, and others. Differential Gene expression of each variant was also investigated by RNA-seq analysis.