Researchers from the University of California, Berkeley have improved the way that genetically-modified E.coli bacteria can produce biofuels from ethanol and fatty acids.
They have developed a genetic sensor that allows the bacteria to regulate their gene expression as a response to varying levels of ethanol or fatty acids. So far, the biofuel production by such bacteria had been limited by this imbalance of biological compounds.
“The pathways weren’t in balance,” said Jay Keasling, professor of chemical engineering and bioengineering. “The cells were wasting resources producing one precursor at a higher level than another.” What’s more, he says, biofuel production would sometimes consume too many fatty acids, which the bacteria need at certain stages of their life cycle, making the strain unstable.
The microbe that Keasling and his colleagues designed uses a naturally-occurring sensor which regulates the microbe’s internal activity of its pathways to correspond to the amounts of internal fatty acids and related molecules.
This improvement made the biofuel production much more stable, because the biofuel production activity doesn’t stop the cell from growing. That, in turn, increased the biofuel production to 28 percent of the theoretical maximum, which was still three times more than what earlier experiments could produce.
However, this technology still can’t brag itself for being efficient enough for commercial production, but it’s nevertheless an important step towards viable bacteria-based biofuels.