Disclosed herein are methods of degrading plant biomass, and microorganisms and polypeptides used in such methods, hi certain embodiments, the methods include growing Anaerocellum thermophilum on a substrate that comprises plant biomass under conditions effective for the A. thermophilum to convert at least a portion of the plant biomass to a water soluble product or a water insoluble product, hi some cases, the method can further include one or more steps to further process the water soluble product or a water insoluble product to produce, for example, a biofuel or commodity chemical. In another aspect, microorganisms that include at least one A. thermophilum plant biomass utilization polynucleotide are disclosed. Also disclosed are methods of transferring one or more A. thermophilum plant biomass utilization polynucleotides to a recipient microorganism. A. thermophilum plant biomass utilization polynucleotides and polypeptides encoded by such polynucleotides are also disclosed. Also disclosed are methods of degrading plant biomass by providing an isolated A. thermophilum polypeptide capable of degrading unprocessed plant biomass, and contacting the A. thermophilum polypeptide with plant biomass under conditions effective for the A. thermophilum polypeptide to at least partially degrade the plant biomass.
STATEMENT OF GOVERNMENT RIGHTS
 This invention was made with government support under a grant from the Department of Energy, Grant No. DE-PS02-06ER64304. The U.S. Government has certain rights in this invention.