The researchers found that growth on switchgrass prompted the organism to express an expanded set of proteins that deal specifically with the hemicellulose content of the plant, including hemicellulose-targeted glycosidases and extracellular solute-binding proteins. Acting together, these two sub-systems work to break down the plant material and import the resulting sugars into the cell. The scientists went on to show that once inside the cell, the organism "switches on" certain enzymes involved in pentose metabolism in order to further process these hemicellulose-derived sugars into usable energy.
"By comparing how C. obsidiansis reacted to switchgrass, relative to pure cellulose, we were able to pinpoint the specific proteins and enzymes that are important to plant cell wall deconstruction—a major roadblock to the production of advanced biofuels," Giannone said.
Journal of proteome published paper http://pubs.acs.org/doi/abs/10.1021/pr200536j