A genetically engineered E. coli bacteria that produces fuel ethanol from biomass waste such as corn stover is being used as the basis for a commercial ethanol plant currently under development.
The bioconversion technology, selected by the Department of Commerce to become Landmark Patent No. 5,000,000, is being commercialized with assistance from the Department of Energy (DOE). BC International Corp., based in Dedham, Mass., holds exclusive rights to use and license the engineered bacteria.
Lonnie Ingram, a professor of microbiology at the University of Florida and a member of the National Academy of Sciences, genetically engineered the E. coli organisms by cloning the unique genes needed to direct the digestion of sugars into ethanol, the same pathway found in yeast and higher plants. He inserted these genes into a variety of bacteria that have the ability to use all sugars found in plant material, but normally produce a worthless mixture of acetic and lactic acids as fermentation products. With the ethanol genes, the engineered bacteria produce ethanol from biomass sugars with 90%–95% efficiency.
Until we developed this new technology, the chemical makeup of biomass prevented it from being used to make ethanol economically. Biomass is a much cheaper source of ethanol than traditional feedstocks such as cornstarch and cane syrup, but the cost of processing is higher.—Prof. Ingram
BC International plans to build a 30-million-gallon biomass-to-ethanol plant in Jennings, La, based on the genetically engineered bacteria. The plant, due to be operational by the end of 2006, will use sugarcane waste as the main feedstock.