Scientists Engineer E. Coli to Make Propane

E. coli is an exceedingly common bacteria that lives in many places including your very own gut. It's also a favorite organism for synthetic biologists looking to engineer useful microbes. By inserting just a few genes in E. coli, scientists have found they can coax the bacterium into making ready-to-use propane.

You might know propane best as the gas that fires up your grill, but it powers a lot more than summer barbecues. Along with butane, propane also makes up liquid petroleum gas, which is used for heating, cooking, and fueling some vehicles. In other words, a renewable source of propane could do a lot of good for the environment.

Scientists Engineer E. Coli to Make Propane

A diagram of the pathway for making propane. Kallio et al, Nature Communication.

E. coli don't make propane naturally, but they do make fatty acids, which can be turned into fuel with some clever bioengineering. In a study published today in Nature Communications, scientists detail how they inserted a synthetic pathway into E. coli. The E. coli is engineered to make three new enzymes, which convert the fatty acid into useable propane.

Eventually, the team hopes to make these bacteria also photosynthetic, so they can manufacture propane from solar energy—a miniature factory in a bacteria cell. That's an ambitious and still far-off goal, given that the amount of propane E. coli can currently make is still about one thousandth of what would be commercially viable. (Fossil fuels are still cheap, for better or worse.) But this is a promising line of research—last year, researchers engineered E. coli to also make diesel—that could one day make our energy consumption a little less terrible for the planet. [Nature Communications via Real Clear Science, Imperial College]

Top image: Liqid petroleum gas tanks. Photo Africa / shutterstock