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

“It looked too perfect to be a rock,” he told the Associated Press.

This is a great example of citizen science, says the Academy’s Peter Roopnarine, curator of Invertebrate Zoology and Geology.

Initial dating by the Transbay’s paleontology consultant put the fossil’s age at around 11,000 years old. The huge tooth—“about a foot in length and 8 inches tall,” according to The Bay Citizen—will be donated to the Academy.

The Academy has other mammoth teeth in its collection, including three specimens found in San Francisco. Other collections from that time period in California include a saber-tooth cat skeleton, bison and dire wolves.

Peter says if we’re able to put the recent find on display, it will be a great opportunity to tell the story of the recent fossil history of San Francisco.

The late Ice Age in California had a rich diversity of mammals—large saber-tooth cats, horses, wolves, bison and of course, mastadons and mammoths. Peter explains that the area was a series of lush valleys with open plains. The nearby ocean provided a very moderate climate—making this region a cooler version of today’s African savannah.

Peter says that it’s always difficult to reconstruct the past in modern, metropolitan areas, where fossils are moved or buried without a second thought. That’s what makes Brandon Valasik’s discovery such a treasure. And the fact that Valasik himself recognized it.

We’re not sure when we will receive the tooth here, but when it does arrive, our scientists will examine the specimen for more clues to the species and age. Stay tuned!