Humans are enamored with our own energy technology. We burn coal, trigger nuclear fission and dam rivers to excite electrons, but the sad fact is that lowly bacteria and algae outperform us every day. Microbes’ metabolism, whether it is converting sunshine or consuming sugar, is state of the art. We can only attempt to imitate it, and poorly at that.
But what if we could build a biological power plant: an energy assembly line made from photosynthetic algae and sugar-hungry bacteria that could directly synthesize the chemicals we want? No expensive refineries, no elaborate engineering—just a sunny, hospitable space for something that nature has quietly perfected during billions of years.
That’s exactly what a group of researchers at the University of Minnesota has done with a Department of Energy (DOE) grant, a firm called BioCee, and an obscure bacteria called Shewanella. The bacteria acts as almost like a biological oil well, directly producing "biohydrocarbons" which can be rendered into anything from diesel fuel to medicines. Their work, if it scales, promises to open up a whole new field of biofuel and chemical research.
"This general approach of taking two different bacteria that would have complementary metabolisms, and then putting them into the latest thin films, that’s novel," says the lead researcher and professor of biochemistry at the University of Michigan, Larry Wackett.
The insight was hiding in plain sight for a few million years. Lichen, a symbiotic organism, operates on a similar principle. Fungal fibers surround algae to convert photosynthetic sugars into hydrocarbons and energy. While the two species are technically independent, they form a symbiotic organism.
The Michigan researchers rewrote this equation with concepts from the chemical industry. The bioreactors manufactured by BioCee are plastic sheets with a 100 micron layer of latex, similar to paint, in which the microorganisms are embedded. Placed together, one sheet acts as a solar collector and the other uses designer bacteria to convert sugar into chemicals. The photosynthetic layer works for months, even if a different bioreactor sheet is swapped out to produce new chemicals. The system is so simple, it can even be mailed and then revived later with water and nutrients.
But it’s early days. "It’s still not proven at scale by any means," says Wackett, "but idea has merit." So far, the researchers have successfully created diesel fuel with the system, and BioCee is touting "a completely new business model for the bioprocess industry" by reducing 90% of capital costs and 50% of operating costs versus conventional fermentation.
If it can scale, and overcome the technical challenges that have plagued other biofuel firms now flirting with bankruptcy, the approach has the potential to turn parts of the biofuel and chemical industries into solar powered sectors available anywhere—eventually.
"The view of the people at [DOE’s] ARPA-E was that … they wanted to hear more proposals that had potential to change the industry," said Wackett in a statement. "This is a high-risk, high-reward venture."