Verenium Corporation has announced the results of a study designed to sequence and analyze the genes found in microbes populating the hindgut of a Costa Rican termite.
The goal of the study, conducted by a consortium of scientific partners including Verenium, California Institute of Technology (CalTech) and the the U.S. Department of Energy's (DoE) Joint Genome Institute (JGI), was to better understand how termites break down cellulose and xylan into component sugars. Such an understanding may reveal better ways of engineering the manufacture of next-generation biofuels.
Although the primary function of the microflora in the termite's hindgut is to degrade cellulosic material, the number and range of novel bacterial genes that scientists found was unexpected and intriguing.
"We were all surprised by the enormous diversity that was revealed, and are excited by the possibilities for future research into the role each gene and enzyme might play in degrading the structural polysaccharides of plants," said Geoff Hazlewood, Ph.D., Verenium's Senior Vice President of Research. "These are important insights into nature's mechanisms that may provide keys to unlocking more effective, industrial methods for converting cellulose to ethanol."
The study findings are being reported in the November 22 issue of the journal Nature, the international journal of science, Volume 450, issue 7169, pp. 560-565.
The work was funded through DoE's Community Sequencing program. The principal investigator was Dr. Jared Leadbetter, Associate Professor of Environmental Microbiology at CalTech. Other partners in the research included JGI, Verenium and INBio, the National Biodiversity Institute of Costa Rica. Together, the team sequenced and analyzed more than 80,000 genes encoded by many of the termites' hindgut bacteria species, including about 1,000 cellulase/xylanase genes.
In partnership with INBio, Verenium created an environmental library of DNA collected from the wood-feeding "higher" termite species, Nasutitermes, found in the rainforest of Costa Rica. The DNA was then sent to JGI for sequencing.
"The degradation of wood components, such as cellulose and xylan, requires a battery of enzymes, and termites are extremely successful in breaking down wood, so they're a rich potential source of biochemical catalysts for converting wood into simple sugars and therefore biofuels," Dr. Hazlewood said.
"Prior to this study, only one gene had been connected to the termite's rare ability to digest and nourish itself with wood, a substance that is energy rich but difficult to break down," Dr. Leadbetter noted.
"The scientific community long suspected that the bacterial species found in a 'higher' termites' hindgut might be involved in this process and results of this study from the gut community of the Nasutitermes termite demonstrated that these suspicions are correct."
Based on these results, Verenium plans to utilize its advanced gene technologies and high-throughput screening capabilities to evaluate the activity of novel cellulases and hemicellulases encoded in this large collection of novel genes in order to attempt to identify enzyme combinations that can be exploited for converting biomass feedstocks into biofuels.