Bacteria that Eat Carbon and Poop Fuel Might Just Save the Planet

The biggest physical advantages of fossil fuels are that they’re energy-dense and portable, which means they store a lot of power. That storage issue is one of the biggest barriers to developing a power grid reliant solely on renewable technologies. Wind strength and sun levels fluctuate at their own whims, as does energy use. Without a way to efficiently store electricity when its being produced in excess to mete out when production dips or demand rises, a fully-renewable grid isn’t feasible.

The problem is the fact that current battery technology sucks. Biofuels are a good replacement for some fossil fuels, but even as demand increases, the bulk of production is still by plants using first-generation biofuel tech that relies on food sources like corn. From a cost standpoint, it’s not likely feasible to replace gasoline with our food supply.

A team of researchers at UCLA has an alternative answer: using modified microbes to convert carbon dioxide into alcohol-based biofuels. Better yet, the microbes sequester and convert atmospheric carbon through electrolysis; with nothing more than a jolt of energy, the amazing microbes create liquid fuel, which is energy-dense and doesn’t lose its charge over time. That’s means it’s a development that could potentially change the energy landscape.

The report, published today in Science, explains how the team of chemical and biomolecular engineers developed a strain of Ralstonia bacteria to produce isobutanol, a high-demand liquid fuel that’s also a target product of cellulosic biofuel producers, who basically create ethanol from trash. The advantage lies in the simplicity; the microbes fixate carbon and convert it to higher alcohols without any more fiddling that electric current.

From the paper:

This integrated process to convert CO2 to liquid fuels does not depend on biological "light reactions." Electricity generated from photovoltaic cells, wind turbines, or off-peak grid power sources can be used to drive CO2 fixation and fuel production. Thus, this process provides a way to increase photosynthetic efficiency by coupling man-made photoelectric generation device with biological CO2 fixation and fuel production capability.

In addition to smoothing out power production from renewable sources – and thereby making them more cost-effective – the report explains that the process could likely be modified to create other compounds based from CO2.

That could be a huge boost to folks looking to commericialize the process; the current trend in biofuel startups is to start by producing high-value boutique petrochemicals, like those used in pharmaceuticals and cosmetics. Those chemicals have great profit margins but a low overall volume of demand, which helps a company keep the lights on as it works towards growing into the high-volum biofuel game.

In any case, the concept of using microbes to suck carbon out of the air and create fuel is mind-blowing. Biofuel production has always been beholden to securing feedstock, whether it be corn, sugar cane, or, in the case of cellulosic producers, railroad ties and municipal waste. Yet here’s a process where the feedstock is not only available in the air, but people want to actively get rid of it. Receiving subsidies for carbon sequestration using a process like this doesn’t seem crazy – especially given the EPA’s serious new regulations on carbon – which makes for an even more attractive business case.

There is a lot of refinement and testing to be done before the process could be economically feasible – cellulosic producers, which rely on proprietary microbial process to convert cellulose to ethanol, have long struggled to ramp up to industrial-scale production due to production complications. But with all of the potential and attractive aspects of the CO2-to-alcohol process, I doubt it will be long before someone tries to take it commercial.

Follow Derek Mead on Twitter.

• Driving the Biofuel Revolution
• Is Renewable Energy a Myth?
• Green Fuels: Not So Green?