2-07: Monitoring the effects of hydrothermal pretreatment on the chemistry and structure of Populus trichocarpa to identify characteristics that affect digestibility

Although pretreatment processes are known to effectively decrease the natural recalcitrance of biomass and dramatically improve sugar yields, few details are understood about the in-depth effects of pretreatment due to limitations in methods for studying plant cell walls.  In this study, we demonstrate the use of a high-throughput tool, Glycome Profiling, to investigate the effects of hydrothermal pretreatment of varying severity.  Glycome Profiling, and related immunolabeling approaches, rely upon a currently available array of monoclonal antibodies that is large and diverse enough to monitor changes occurring in most major plant cell wall polysaccharides.  We have utilized these techniques to monitor changes in the plant cell walls of Populus trichocarpa that result from pretreatment, and will demonstrate their usefulness in relating observed structural changes to improvements in digestibility.  Based on these initial results, additional Populus trichocarpa samples are being produced by applying the sequential chemical extraction procedures used in Glycome Profiling to create a subset of samples that vary in pectin, hemicelluose, cellulose, and lignin content and composition.  These samples will then be characterized by a variety of analytical techniques, and will also be subjected to enzymatic hydrolysis to further aid in the identification of specific cell wall characteristics that have an impact on digestibility.