Biological wizardry ferments carbon monoxide into biofuel

Cornell biological engineers have deciphered the cellular strategy to make the biofuel ethanol, using an anaerobic microbe feeding on carbon monoxide - a common industrial waste gas. 'Instead of having the waste - pardon the pun - go to waste, you make it into something you want,' said Ludmilla Aristilde , assistant professor in biological and environmental engineering. 'In order to make the microbes do our work, we had to figure out how they work, their metabolism.' Aristilde collaborated with her colleague Lars Angenent, professor of biological and environmental engineering, on the project. She explained, 'The Angenent group had taken a waste product and turned it into a useful product.' To make biofuel from inorganic, gaseous industrial rubbish, the researchers learned that the bacterium Clostridium ljungdahlii responds thermodynamically - rather than genetically - in the process of tuning favorable enzymatic reactions. Postdoctoral researcher Bastian Molitor, research specialist Wei Chen, former postdoctoral researcher Hua Wei, and former senior research associate Hanno Richter are also co-authors on the paper, 'Ethanol Production in Syngas-Fermenting Clostridium ljungdahlii Is Controlled by Thermodynamics Rather Than by Enzyme Expression,' published in the May 2016 issue of Energy and Environmental Science. Synthetic gas - or syngas - fermentation is emerging as a key biotechnological solution, as industrial-sized operations are looking to produce ethanol from their gaseous waste streams, according to Angenent, a fellow at Cornell's Atkinson Center for a Sustainable Future.