(387b) Application of An Integrated High Throughput Pretreatment and Enzymatic Hydrolysis (HTPH) Screening Tool to Investigate Radial Variation in Populus Conference: AIChE Annual MeetingYear: 2010Proceeding: 2010 AIChE Annual MeetingGroup: Forest and Plant Bioproducts DivisionSession: Biorefinery - Biochemical Conversion and Biomass Recalcitrance Time: Wednesday, November 10, 2010 - 8:55am-9:20am Authors: DeMartini, J. D., University of California Riverside Wyman, C. E., University of California, Riverside A high throughput pretreatment and enzymatic hydrolysis (HTPH) method was developed to screen natural and genetically modified biomass types to identify those with lower recalcitrance to sugar release, define pretreatment conditions, and screen enzyme formulations. In support of this system, a scaled-down method was devised to accurately measure biomass compositions without prior calibrations, dramatically reducing the amount of material sacrificed for compositional analysis and allowing easier replication of samples. Application of these two methods facilitated the investigation of radial variation in composition, sugar release, and recalcitrance in two cross sections of Populus tremuloides. The data revealed that while substantial within tree radial variation existed for composition and sugar release (g sugar released / g biomass), sugar yields (g sugar released / g sugar available) were far less variable across the radial sections. Results from this study will be presented to provide insight on structural changes in wood resulting from juvenile to mature transitions that effect recalcitrance, results which may also have implications for determining the optimal harvest age of Populus trees for conversion to sugars.