S111: Extreme thermophiles from Yellowstone National Park for deconstructing lignocellulosic biomass

Extreme environments such as terrestrial hot springs are known to support the growth of thermophilic bacteria capable of hydrolyzing cellulosic biomass. Obsidian Pool, located in the Mud Volcano area of Yellowstone National Park, USA, was chosen for an in-depth compositional analysis of its anaerobic, cellulolytic microbial community. Novel isolates from several different bacterial genera including Caldicellulosiruptor, Dictyoglomus, and Thermoanaerobacter were recovered from enrichments on biomass substrates using a high-throughput single-cell isolation technique. A new species of Caldicellulosirptor, designated C. obsidiansis, displayed rapid growth on a wide range of polymeric carbohydrates at 80^oC and was chosen for further study. The genome sequence revealed several large open reading frames encoding multifunctional enzymes with glycoside hydrolase family 5, 9, 10, and 48 catalytic domains. Classical strain development techniques are being applied to manipulate end product profiles and ethanol tolerance. In addition, co-cultures with hydrogenotrophic bacteria were established to evaluate cooperative growth on crystalline cellulose and xylan. Further characterization of these organisms will provide insights into their potential use in bioenergy production and other biotechnological applications.