This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Cellulosic biomass, the inedible fibrous part of plant cell walls, has great potential as a source of sugars that could be used as platform chemicals to make fuels, materials and other chemicals. However, the complex structure and composition of biomass impedes its efficient degradation and conversion into sugars. Most sugars are locked in crystalline cellulose fibers which are sheathed in hemicellulose and encrusted in lignin. We are looking to nature to overcome this technical roadblock. Although many fungi degrade parts of biomass, white rot fungi are unique in their ability to degrade it completely. By using a combination of different techniques we hope to capture the degradation strategies of white rot fungus Phanerochaete chrysosporium on Poplar (a biomass source with commercial potential) and then to optimize for possible industrial application. Our major scientific objectives are to define the key metabolites and enzymes secreted by P.chrysosporium during degradation, using mass spectrometry, and then to relate these factors to specific degradation events in the Poplar samples. We hope to identify those specific degradation events by careful structural and compositional analysis of Poplar samples at different stages of fungal degradation. We are using scanning microprobe X-ray diffraction (SMX) using the BioCAT beamline 18ID as one of our tools to approach this problem, Our hope is that not only will this work advance our understanding of a biological process of fundamental importance to our ecosystem but that it will also provide insights that guide the design for industrial