Good to the Last Drop

Researchers at the Joint BioEnergy Institute have developed a biological mechanism to keep microbes from poisoning themselves after they produce biofuels, says ClimateWire's Umair Irfan. This dynamic sensor-regulator system "acts as a shock absorber, slowing down chemical production in a cell before it reaches toxic levels and scaling it back up when the coast is clear," Irfan says. "Organisms using a DSRS survive longer and produce more fuel." The researchers used a version of E. coli engineered to produce diesel fuel. The diesel itself is not dangerous to the microbes, but precursors like fatty acids and ethanol can be lethal in high concentrations. The DSRS responds to high concentrations of these molecules and trigger enzymes that convert them into diesel before they become toxic, Irfan says. "Bacteria engineered with a DSRS produced up to three times more fuel than those without," he adds. Further, these results could be used in other microbial pathways, to make drugs as well as fuels.