The 2.4 Mb genome of the cellulose-degrading thermophile, Acidothermus cellulolyticus 11B, was completely sequenced by the Joint Genome Institute (DOE) in 2006. The genome offers useful insights into the lignocellulose deconstruction capabilities of the organism. The A. cellulolyticus genome revealed several new secreted glycoside hydrolases and carbohydrate esterases, indicating a diverse biomass-degrading enzyme repertoire, and significantly elevating the industrial value of this organism. A sizeable fraction of these hydrolytic enzymes break down plant and fungal cell walls. Findings from functional enzyme studies and insights into the evolutionary and functional implications of the A. cellulolyticus cellulolytic and xylanolytic capabilities will be presented.