Hungry Microbes Making Biodiesel
May 23, 2014

Hungry Microbes Making Biodiesel

Some of the things holding back the development of biodiesel fuels is that, firstly, fossil fuels have been needed in the production process and, secondly, that producers have had to pay very hefty fees to have all the toxic runoff of the process hauled off to treatment plants. While far from the only things holding back the development of these more eco-friendly fuels, they have been major deterrents for a number of potential developers and investors. Fortunately, these problems may have just been solved, thanks to an astonishing new development from Michigan State University. This new concept, developed by Gemma Reguera, a microbiologist from MSU, will put an end to the creation of hazardous wastes during the production process while also taking the dependence on fossil fuels out of the equation all together.

Reguera’s process uses microbes to draw ethanol from glycerol and, as part of the process, even cleans up the waste-water which will allow producers to reincorporate the ethanol and water back into the fuel-making process. How is all this possible? Through Reguera’s patented adaptive-engineered bacteria called Geobacter sulfurrenducens.

Having shown a great deal of promise in cleaning up nuclear waste and improving other biofuel processes, Reguera has been working on engineering the conductive pili of Geobacter to allow them to withstand increased levels of toxic glycerol. Next, Reguera and her team needed a partner bacteria that would ferment the glycerol into ethanol while generating byproducts that would then be consumed by the Geobacter. After developing this robust bacterium, they paired it with Geobacter to create Geobacter sulfurrenducens. According to Reguera, “We matched them up like dance partners, modifying each of them to work seamlessly together and eliminate all of the waste.” Together, these bacteria have a nigh inexhaustible appetite for the toxic byproducts generated in the process of making ethanol from glycerol. “They feast like they’re at a Las Vegas buffet,” Rugeura added. “One bacterium ferments the glycerol waste to produce bio-ethanol, which can be reused to make bio-diesel from oil feedstock. Geobacter removes any waste produced during glycerol fermentation to generate electricity. It is a win-win situation.”

These hungry little microbes are the primary component of Reguera’s microbial electrolysis cells, or MECs for short. Rather than harvesting electricity as an output, these fuel cells Reguara has theorized use a small electrical input platform to make hydrogen and thereby increase the efficiency of the MECs. Showing incredible potential, Reguera’s process has already drawn the attention of several economic developers who are all helping to scale up her efforts. At present, thanks to a Michigan Translational Research and Commercialization grant, Reguera and her team are working on developing prototype MECs that can handle larger volumes of waste than anything they have tried before in their labs. There are also talks with MBI, the bio-based technology “de-risking” enterprise operated by the MSU Foundation, to develop industrial-scale MECs that could potentially handle the capacities of a full-scale plant.

Reguera’s work is a tremendous breakthrough in the name of a cleaner, less fossil-fuel dependent future. With the next step being field tests with a Michigan-based biodiesel manufacturer, we will have to wait and see just how well these MECs work and if they can perform well enough to meet the demands of our fuel-driven lives.

As of now, the outcome looks to be very promising.

Image Credit: Thinkstock

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