14 DAY TRIAL // In a bid to provide clean and environmentally-safer fuel for the transportation industry, experts at the University of California in Berkeley (UCB) have engineered bacteria that are capable of producing biofuel similar to gasoline at ten times the rate microbes are capable of.
The breakthrough could stir up a competition between research teams using either of the two types of microorganisms, and it's the people and nature that would ultimately stand to gain from it.
The study was led by UCB assistant professor of chemistry Michelle C. Y. Chang, who was helped by graduate students Brooks B. Bond-Watts and Robert J. Bellerose. Details were published in the latest issue of the esteemed journal Nature Chemical Biology.
The scientists decided to focus their attention on the chemical n-butanol, which is the most basic and common form of butanol. This substance was proposed as a potential substitute for gasoline and diesel some time ago, the team explains.
As such, the UCB group decided to investigate the properties of bacteria called Clostridium, which was found to be producing n-butanol naturally. The experts then genetically-altered the organism.
They were however aware of avoiding a problem that other scientists stumbled upon when doing the same things. This is not the first time that enzymes responsible for butanol production are taken out of Clostridium and inserted in other organisms, such as yeast and E. coli.
However, past experiments were only able to boost butanol production to half a gram per liter, far too low to allow the fuel to be sold at prices lower than that of gasoline and diesel fuel.
One of the main problems that were encountered was that the same enzymes that created butanol in these organisms were also responsible for converting some of it back into its constituents.
In order to circumvent this issue, the UCB team replaced two of the five enzymes taken from the Clostridium bacteria with similar chemical components, but taken from other microorganisms.
E. coli bacteria modified in this manner were able to sustain a butanol production level of 5 grams per liter, 10 times more than their industrial microbe system counterparts.
“We are in a host that is easier to work with, and we have a chance to make it even better. We are reaching yields where, if we could make two to three times more, we could probably start to think about designing an industrial process around it,” Chang says.
“We were excited to break through the multi-gram barrier, which was challenging,” the expert concludes.