E. coli Bacteria Engineered To Produce Diesel From Biomass.

E. coli Bacteria Engineered To Produce Diesel From Biomass.

AFP (1/28) reports, "Gene scientists have coaxed bacteria into eating agricultural waste and secreting diesel, offering a potentially cheaper, greener energy source than present-day biofuels," according to the results of a recent study published in the journal Nature. The researchers created "a genetically-engineered version" of Escherichia coli that "feasts on the simple sugars found in wood chips, straw and other biomass waste and secretes molecules of fuel." Jay Keasling, a chemical engineer with Lawrence Berkeley National Laboratory and the lead author of the study said, "The engineered E. coli secretes the biodiesel from the cell, which means that we don't need to break open the cell to get the diesel out." Further, Keasling said, "the biodiesel is insoluble in water, which means that it forms a separate phase when it is secreted from the engineered E. coli."

        Scientific American (1/28, Biello) reports explains that the biodiesel "floats to the top of a fermentation vat, so there is neither the necessity for distillation or other purification processes nor the need, as in biodiesel from algae, to break the cell to get the oil out." The researchers "cloned genes from Clostridium stercorarium and Bacteroides ovatus...which produce enzymes that break down cellulose," and "then added an extra bit of genetic code in the form of short amino acid sequences that instruct the altered E. coli cells to secrete the bacterial enzyme, which breaks down the plant cellulose, turning it into sugar; the E. coli in turn transforms that sugar into biodiesel." According to Scientific American, "the process is perfect for making hydrocarbons with at least 12 carbon atoms in them, ranging from diesel to chemical precursors -- and even jet fuel, or kerosene." However, "it cannot, yet, make shorter chain hydrocarbons like gasoline."

        Technology Review (1/28, Bourzac) notes that the bacteria was "developed by South San Francisco company LS9 in collaboration with researchers at the University of California, Berkeley." The company "has demonstrated the bacteria in pilot-scale reactors and plans to scale the process to a commercial level later this year." The project "is part of an increasing push by bioengineers to bring down the cost of biofuels by developing microbes that can turn biomass...into fuels without any additional processing that would require expensive catalysts and high temperatures."

        In the MSNBC (1/28) "Cosmic Log" blog, Alan Boyle notes that "Keasling emphasized that the study...was a 'proof of concept' rather than the demonstration of a commercially viable process." CNET (1/28, LaMonica) also reports the story.