Researchers have reported that they have engineered a microbe to produce diesel fuel from carbon dioxide.
“We’ve shown that the bacterium Ralstonia eutropha growing with carbon dioxide and hydrogen gas is able to generate significant quantities of diesel-range methyl ketones,” says lead researcher Harry Beller, a microbiologist at the US Department of Energy’s Joint BioEnergy Institute (JBEI).
“This holds the promise of making carbon-neutral biofuels using non-photosynthetic, carbon-dioxide fixing bacteria as a less resource-intensive alternative to making these biofuels from cellulosic biomass,” he added.
Current strategies for producing advanced biofuels that could replace petrol, diesel or jet fuels in today’s engines and infrastructures are based on extracting fermentable sugars stored in the cellulosic biomass of green plants. Those sugars represent chemical energy that was converted from solar energy via photosynthesis and provide the carbon atoms needed to make fuels. R. eutropha is a common soil bacterium that can naturally use hydrogen rather than sunlight as an energy source for converting carbon dioxide into various organic compounds. However, native strains of R. eutropha do not produce detectable levels of methyl ketones and generate very low levels of the fatty acids that are precursors to methyl ketones.
“Since our engineered strains of R. eutropha can use fixed carbon dioxide to make methyl ketones, its biofuels don’t require many of the steps needed to convert cellulosic biomass into fuels,” Beller says. “The resources needed for these steps could therefore be eliminated if R. eutropha were used to make biofuels directly from carbon dioxide.”
Source: Lawrence Berkeley Lab