12-01: Identification of Desirable Traits in Miscanthus to Enhance Total Sugar Yields in Biological Conversion

Miscanthus, which has a very high productivity, was selected by DOE as one of the potential biomass crops to support large scale production of fuels. Improving our understanding of features that control enzymatic hydrolysis and how pretreatment alters these features for this prolific crop would be a significant step to identifying better strategies and opportunities to genetically alter the susceptibility of biomass to deconstruction and achieve very high total sugar yields at low costs.   In this study, a number of Miscanthus species were screened based on chemical composition and structure to identify the most promising species for more detailed characterization by pretreatment and enzymatic hydrolysis. Then, water-only and dilute acid batch and flowthrough pretreatments were applied to those varieties to define how sugar yields and release profiles vary among species and to develop meaningful cause-and-effect relationships of factors that control deconstruction of hemicellulose, cellulose, lignin, and other subcomponents. Profiles of glucose, xylose, and total sugar release from selected Mischanthus species were determined for various combinations of  time, acid concentration, flow rate, and temperature followed by enzymatic hydrolysis of the pretreated solids. The resulting data and models provide a new perspective on how sugar yields vary with species of Miscanthus during pretreatment and biological processes and key features that could govern sugar yields.