What if the bacteria in your gut could produce a cleaner fuel for cars and trucks? It turns out, with a little fiddling, they can!

Researchers in the United Kingdom took the common gut bacteria, Escherichia coli, and added genes from the camphor tree, blue-green algae and two other bacteria (Photorhabdus luminescens and Bacillus subtilis). The addition of genes from blue-green algae and the two bacteria allow E.coli to make hydrocarbons from fatty acids; the camphor tree genes makes the hydrocarbons a similar length to those found in fossil fuels.

So when the scientists fed the glucose from plants to the souped-up E. coli, the gut bacteria turned the food into a fuel very similar to the diesel fuel derived from crude oil. Voilà! Gut Fuel!

The remarkable thing about this biofuel—a fuel derived directly from living matter— is that it can be pumped into current gas tanks with absolutely no modifications. Most other biofuels require vehicle owners to adjust their engines to operate with the more sustainable liquids, or involve mixing the biofuel with traditional fossil fuels.

John Love, of the University of Exeter, says this was a priority. “Producing a commercial biofuel that can be used without needing to modify vehicles has been the goal of this project from the outset. Replacing conventional diesel with a carbon neutral biofuel in commercial volumes would be a tremendous step towards meeting our target of an 80% reduction in greenhouse gas emissions by 2050.”

Well, not so fast… Producing this new biofuel en masse will take a lot more work. The scientists are hoping to wean the E. coli off plants and use animal or agriculture waste instead. Otherwise, they foresee a similar problem for their new biofuel as that faced by current biofuels—it’s tough to argue that we should be devoting our farmlands to growing fuels over growing food.

In addition, E. coli hydrocarbons cost more to produce than fossil fuel hydrocarbons. At least on paper. But in the long run, probably not.

The research is published in this week’s Proceedings of the National Academy of Sciences.

Image: Marian Littlejohn

An article published earlier this month in the New York Times demonstrates how the high price of corn in places like Guatemala is devastating:

Recent laws in the United States and Europe that mandate the increasing use of biofuel in cars have had far-flung ripple effects, economists say, as land once devoted to growing food for humans is now sometimes more profitably used for churning out vehicle fuel.

And, cows are feeling it, too, according to a recent post on Wired called “When Corn Costs Soar, Cows Eat Cake.” Literally.

But researchers across the country are looking for alternatives.

A study in Nature this week begins:

Legislation on biofuels production in the USA and Europe is directing food crops towards the production of grain-based ethanol which can have detrimental consequences for soil carbon sequestration nitrous oxide emissions, nitrate pollution, biodiversity and human health.

So the researchers ask, why not use some of the native grasses and flowers that grow on fallow land anyway? Scientific American describes it:

… species such as goldenrod, frost aster, and couch grass, among others—can deliver roughly the same amount of biofuel energy per hectare per year if fertilized, yet also reducing CO2 by more than twice as much as corn.

The scientists also propose small, local biorefineries to process the fuels, saving on transportation. But the ideas are not without their critics—NPR offers a few of the arguments against the study.

A recent article in the San Francisco Chronicle reports on an older study in Nature about local researchers developing a new biofuel from a process formally used to create explosives. The process could potentially use sugar sources from non-food plants and contains more energy per gallon than corn-based ethanol. The article says that in California, the fuel could be used “in trucks, trains and other vehicles that need more oomph than hybrid or battery power can provide.”

We’ve written in the past about algae biofuels. How about fungi biofuels? An NSF-supported study looks at the potential of endophytes, fungi that live inside of plants and naturally produce monoterpenes, which can be used as fuel. And the fungi could produce this biofuel from agricultural, forestry and urban wastes! NSF Discoveries has more information about the cutting-edge idea.

Finally, the Department of Energy announced funding for five sustainable biofuel projects earlier this month, National Geographic reports.

Any way you look at it, our future will be fueled by a variety of sources—hopefully all clean and renewable…

Image: J.E. Doll, Michigan State University