Fermenting carbon monoxide into biofuel

Cornell University have announced that their biological engineers have developed a strategy than enables the production of biofuel ethanol from the common waste gas, carbon monoxide.

The paper in which this technology was revealed is called, “Ethanol Production in Syngas-Fermenting Clostridium ljungdahlii Is Controlled by Thermodynamics Rather Than by Enzyme Expression”, it was first published in the May 2016 issue of Energy and Environmental Science and was authored by Postdoctoral Researcher Bastian Molitor, Research Specialist Wei Chen, Former Postdoctoral Researcher Hua Wei, and Former Senior Research Associate Hanno Richter.

“In order to make the microbes do our work, we had to figure out how they work, their metabolism” said Ludmilla Aristilde, Assistant Professor in biological and environmental engineering. Aristilde collaborated with her colleague Lars Angenent, Professor of biological and environmental engineering and a fellow at Cornell’s Atkinson Center for a Sustainable Future, on the project.

In order to manufacture biofuel from inorganic, gaseous industrial rubbish, researchers learned that the bacterium Clostridium ljungdahlii responds thermodynamically, rather than genetically, in the process of tuning favourable enzymatic reactions.

Synthetic gas (syngas) fermentation is growing in popularity as a key biotechnological solution, as industrial operations are beginning to look into taking their gaseous waste streams and producing ethanol, according to Angenent. The scientists sought to understand the physiological nature of the process. “These findings are important for the syngas fermentation community to design future strategies to improve production,” Angenent said.

The scientists discovered that the microbe digests and then ferments carbon monoxide. Likening microbial digestion to the digestive process that humans undergo when we eat Aristilde said, “Microbes are the same. In terms of biostructure, the bacterial cells are starving for nutrients, so they are responding metabolically, which leads to a desired outcome, ethanol production.”

To get the microbe to ferment the carbon monoxide, scientists “bubble it in the growth medium solution,” explains Angenent, where the cells can feed on it. Angenent said carbon monoxide gas emitted as a byproduct of heavy industries has the potential to be redirected to bioreactors that contain these bacterial cells.

Aristilde continued, “The microbial cells then turn it into ethanol, an organic molecule. And carbon monoxide, an inorganic molecule, turns into something valuable we can use. That’s what makes this special.”

Research funding was provided by the National Science Foundation, the German Research Foundation, Philanthropist Yossie Hollander and the Foundation des Fondateurs, which was managed through the Atkinson Center for a Sustainable Future.

Edited from various sources by Francesca Brindle

Sources: Cornell Chronicle, Science Daily

Read the article online at: https://www.hydrocarbonengineering.com/clean-fuels/27072016/cornell-university-biological-engineers-discover-anaerobic-digestion-turning-carbon-monoxide-into-biofuel-3787/