Systems Biology Research on Cellulose and Lignin Degrading Fungi
Plant biomass is made up of long, repeated sugar chains (cellulose and hemicelluloses) interwoven with a complex interlinked network of aromatic compounds (lignin). The resulting structures are remarkably resilient to degradation, but a number of microbes have evolved sophisticated enzymatic systems that allow them to deconstruct and feed on biomass. A collaborative team of researchers at the DOE Great Lakes Bioenergy Research Center (GLBRC), the DOE Joint Genome Institute, and the USDA Forest Products Laboratory have now completed a systems biology study examining gene expression and enzyme secretion by two wood-degrading fungi. The goal of the research was to compare mechanisms of wood-decay between a relatively well characterized cellulose-degrading fungus and a poorly understood fungus capable of degrading the lignin portion of wood. Although the two fungi were shown to share some common mechanisms for biomass deconstruction, substantial differences were observed in the timing and types of enzymes expressed during wood degradation, especially in those mediating the iron catalyzed reaction that breaks apart lignin moieties. The results of this study increase our understanding of molecular mechanisms that allow degradation of complex biomass, providing new insights into a major carbon cycling process in forest ecosystems and development of novel approaches for biofuels production.
A.V. Wymelenberg et al. 2010 “Comparative Transcriptome and Secretome Analysis of Wood Decay Fungi Postia placenta and Phanerochaete chrysosporium” Applied and Environmental Microbiology 76: 3599-3610.