A team of researchers at the Department of Energy's BioEnergy Science Center (BESC) have pinpointed the exact, single gene that controls ethanol production capacity in a microorganism. This discovery could be the missing link in developing biomass crops that produce higher concentrations of ethanol at lower costs.

"The Department of Energy relies on the scientific discoveries of its labs and research centers to improve the production of clean energy sources," said Energy Secretary Steven Chu. "This discovery is an important step in developing biomass crops that could increase yield of ethanol, lower production costs and help reduce our reliance on imported oil."

The discovery of the gene controlling ethanol production in a microorganism known as Clostridium thermocellum will mean that scientists can now experiment with genetically altering biomass plants to produce more ethanol. Current methods to make ethanol from a type of biomass found in switchgrass and agricultural waste require the addition of expensive enzymes to break down the plant's barriers that guard energy-rich sugars.

Scientists, including those at BESC, have been working to develop a more streamlined approach in which tailor-made microorganisms produce their own enzymes that unlock the plant's sugars and ferment them into ethanol in a single step. Identifying this gene is a key step towards making the first tailor-made microorganism that produces more ethanol.

Although scientists have studied Clostridium thermocellum for decades, the genetic basis for its ability to tolerate higher concentrations of ethanol had not been determined. Rather than using just one technique or one approach, the research team that made the discovery was able to draw upon multiple experts spanning several scientific disciplines to contribute a broader set of analyses because of the BESC partnership.

BESC is led by Oak Ridge National Laboratory and is one of three DOE Bioenergy Research Centers established by the DOE's Office of Science in 2007. The centers support multidisciplinary, multi-institutional research teams pursuing the fundamental scientific breakthroughs needed to make production of cellulosic biofuels, or biofuels from nonfood plant fiber, cost-effective on a national scale.

The team's results were published in the Proceedings of the National Academy of Sciences. The invention is available for licensing.

(ScienceDaily, 16/08/2011)