Scientists have transformed E. coli, the bacteria responsible for most cases of food poisoning, into an efficient biological factory to produce diesel and other hydrocarbons from sugars cheaply and also secrete enzymes to break down cellulose.
Chemical engineer Jay Keasling of the University of California, Berkeley (UC-B), and his colleagues have manipulated the genetic code of E. coli, a common gut bacteria, so that it can chew up plant-derived sugar to produce diesel and other hydrocarbons.
“The fuel that is produced by our E. coli can be used directly as bio-diesel. In contrast, fats or oils from plants must be chemically esterified before they can be used.”
“We incorporated genes that enabled production of bio-diesel — esters [organic compounds] of fatty acids and ethanol — directly,” Keasling explains.
“The organism can produce the fuel from a very inexpensive sugar supply, namely cellulosic biomass,” Keasling adds.
The E. coli directly secretes the resulting bio-diesel, which then 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 bio-diesel from algae, to break the cell to get the oil out.
This new process for transforming E. coli into a cellulosic bio-diesel refinery involves the tools of synthetic biology.
After all, the U.S. alone burns some 140 billion gallons of gasoline a year, compared with just two billion gallons of bio-diesel, says an UC-B release.
These findings were published in the January issue of Nature.
