Scientists use bacteria to convert CO2 into valuable chemicals

In a new study from Northwestern University, scientists have engineered bacteria that can break down carbon waste into valuable industrial chemicals. The team optimized one particular strain of bacteria to convert carbon dioxide into acetone and isopropanol (IPA). 

The technology has the potential to help remove greenhouse gases from the atmosphere while reducing the use of fossil fuels, ultimately contributing to a net-zero emissions economy. 

Study senior author Michael Jewett is a professor of Chemical and Biological Engineering at Northwestern’s McCormick School of Engineering and director of the Center for Synthetic Biology. He co-led the study with Michael Koepke and Ching Leang, who are both researchers at LanzaTech.

“The accelerating climate crisis, combined with rapid population growth, pose some of the most urgent challenges to humankind, all linked to the unabated release and accumulation of CO2 across the entire biosphere,” said Jewett. 

“By harnessing our capacity to partner with biology to make what is needed, where and when it is needed, on a sustainable and renewable basis, we can begin to take advantage of the available CO2 to transform the bioeconomy.”

Acetone and isopropanol are versatile chemical solvents that are widely used for a number of different applications. The chemicals have a combined global market value of $10 billion. But while these chemicals are incredibly useful and high in demand, their production requires the use of the fossil fuels that drive global warming. 

The Northwestern team has found a way to manufacture these chemicals more sustainably through a new gas fermentation process. The technique uses Clostridium autoethanogenum, an anaerobic bacterium engineered at LanzaTech, and synthetic biology tools which ferment CO2 to make acetone and IPA.

“These innovations, led by cell-free strategies that guided both strain engineering and optimization of pathway enzymes, accelerated time to production by more than a year,” said Jewett.

The Northwestern and LanzaTech teams believe the developed bacterial strains and fermentation process could be used on an industrial scale. 

“This discovery is a major step forward in avoiding a climate catastrophe,” said Jennifer Holmgren, LanzaTech CEO.

“Today, most of our commodity chemicals are derived exclusively from new fossil resources such as oil, natural gas or coal. Acetone and IPA are two examples with a combined global market of $10 billion. The acetone and IPA pathways developed will accelerate the development of other new products by closing the carbon cycle for their use in multiple industries.”

The study is published in the journal Nature Biotechnology.

–—

By Chrissy Sexton, Earth.com Staff Writer