Microbes: Cleaning Up (and Improving) Biodiesel's Act

Biodiesel plants, while "green," are not entirely environmentally sustainable. Now a pair of genetically engineered microbes may be the perfect solution, cleaning up biodiesel plant wastewater while producing ethanol and electricity to help fuel the fuel-making process.

According to Michigan State University (MSU) researcher Gemma Reguera, current bio-diesel plants "pay hefty fees to have toxic wastewater hauled off to treatment plants" - a problem which makes the "green" fuel costly and not entirely sustainable, according to a university press release.

To solve this problem, Reuguera and a team of graduate students genetically tweaked a microbe called Geobacter so that it could thrive in heavy amounts of toxic glycerol - a toxin that is the byproduct of traditional biofuel production. Geobacter, which have shown promise in cleaning up nuclear waste in past studies, have also been known to manage electrical activity during biofuel production, increasing the efficiency of the process.

Another bacteria was then incorporated that could ferment toxic glycerol into ethanol while simultaneously producing byproducts that the Gerobacter could survive off.

"We matched them up like dance partners, modifying each of them to work seamlessly together and eliminate all of the waste," Reugera said. "One bacterium ferments the glycerol waste to produce bioethanol, which can be reused to make biodiesel from oil feedstocks. Geobacter removes any waste produced during glycerol fermentation to generate electricity. It is a win-win situation."

In-fact, it's such a 'win-win,' that the patented process, which was presented in the journal Environmental Science and Technology, has already garnered attention of economic developers.

"Through a Michigan Translational Research and Commercialization grant, Reguera and her team are developing prototypes that can handle larger volumes of waste," according to an MSU press release.

Still, it will likely be a long time before any industrial sized microbe-assisted bio-fuel plants begin popping up across the country. As of now, it has only been successfully achieved on a small scale in a lab-controlled environment.

The study was published in Environmental Science and Technology on May 6.