Cellulose and hemicellulose are considered the largest components of plant biomass and researchers have been looking for ways to break down these materials efficiently and cost-effectively for commercial cellulosic biofuel production.
Many microbes that can break down biomass do so with the help of enzyme complexes known as cellulosomes, and the DOE JGI has been sequencing the genomes of several bacteria and archaea to harness their capabilities in this field.
|The anaerobic bacterium Clostridium thermocellum can directly convert cellulose from biomasss into ethanol.(Image by E. A. Bayer and R. L. Lamed)|
In a paper published online October 1, 2010 in the Journal of Bacteriology, several DOE JGI researchers including Director Eddy Rubin report that 20 species of the bacteria Clostridia have been sequenced at the Institute using Sanger, 454 and Solexa (Illumina) methods. Due to assembly and finishing issues, seven of the 20 genomes, including the heavily-studied thermophile C. thermocellum, are left as high-quality permanent draft genomes.
Of the remaining 13 bacterial species, nine of the genomes have been finished, including C. cellulolyticum, which was isolated from decayed grass compost and can ferment plant materials to produce ethanol and hydrogen for use as alternative energy sources. Three of the Clostridia genomes are still being sequenced and the other three genomes are in queue to be sequenced. In keeping with Director Rubin’s goals of providing users with services beyond sequencing, all draft genomes were annotated through the JGI-ORNL annotation pipeline and then analyzed using the JGI Integrated Microbial Genomes data management system.