A team of scientists at MIT has tweaked a common bacteria into producing biofuel the way a cow produces milk: without having to be squished. The new bacteria simply expels biofuel into its growing medium instead of retaining it within its body. If the process can be scaled up to a commercial level, it could be far more economical than conventional systems, in which the microorganism must be destroyed in order to recover the fuel.
Milking Microscopic Cows for Biofuel
The MIT team used the soil-dwelling bacteria Ralstonia eutropha as its subject. According to MIT writer David Chandler, when the bug is starved for certain nutrients it will stop growing, but it will continue to produce and store complex carbon compounds.
In its natural state, R. eutropha stores the compounds as a type of bioplastic.
The team has engineered a new strain that will release the compounds in the form of isobutanol, which is beginning to find use as a drop-in replacement for gasoline.
More Green Jobs for Microbes
The Department of Energy’s ARPA-E cutting-edge-technology funding arm is behind the MIT research, and the agency sees a lot of promise in bio-based isobutanol. In addition to funding outside projects, DOE’s BioEnergy Science Center is developing a way to convert woody plants into isobutanol with the help of a cellulose-destroying microbe called Clostridium celluloyticum.
Environmental restoration, fuel cells and bioplastic production are some of the other ways in which the natural processes of microorganisms are being harnessed to replace petrochemicals and other potentially toxic substances.
Sustainable Biofuel Farming
Algae biofuel is already providing the biofuel industry with an opportunity to go big, without impinging on land needed for food, conservation, or habitat preservation. Biofuel from bacteria fits into this category, too.
Like algae, bacteria biofuel farming could lend itself to urban farming, potentially making use of derelict sites under the EPA’s brownfields-to-clean energy program.
Also like algae, a bacteria biofuel farm could be sited at active industrial facilities, where it could capture carbon dioxide as a nutrient.
In that regard, we are still a bit far off from free-flowing fountains of bacterial biofuel. According to Chandler, MIT’s bug is currently chugging away in the laboratory on a rather dainty diet of fructose.
The next step is to get it to use carbon dioxide as a carbon source. Agricultural and municipal waste are also potential sources.
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Tina Casey specializes in military and corporate sustainability, advanced technology, emerging materials, biofuels, and water and wastewater issues. Tina’s articles are reposted frequently on Reuters, Scientific American, and many other sites. You can also follow her on Twitter @TinaMCasey and Google+.
