UW synthetic biologist James Carothers wins ARPA-E award to develop new CO2 bioconversion process

An interdisciplinary research team led by University of Washington chemical engineering associate professor James Carothers received $1.7 million in funding from the U.S. Department of Energy’s Advanced Research Projects Agency-Energy (ARPA-E). The funding will be used to develop scalable, cell-free platforms that enable the capture and conversion of carbon dioxide (CO2) into industrial chemicals, providing manufacturers with a cheaper, more efficient and sustainable means of chemical production.

James Carothers
James Carothers

“Cell-free systems have the potential to revolutionize biomanufacturing; however, it has been challenging to integrate the large number of disparate functionalities required for complex processes,” said Carothers, who is also member faculty at the UW’s Molecular Engineering & Sciences Institute and the Center for Synthetic Biology. “We are developing technologies that could be used to assemble novel biocatalytic pathways, paving the way for the robust transformation of greenhouse gases like CO2 to desirable chemical products.”

Building a functional multi-enzyme system from the bottom up requires a vast array of expertise. The team includes Dr. Alex Beliaev, a microbial physiology expert and senior staff scientist at the Pacific Northwest National Laboratory, professor Neha Kamat, membrane-based biomaterials expert at Northwestern University, professor Vincent Noireaux, a pioneer of cell-free transcription-translation systems at the University of Minnesota, and Georgia Tech professor Pamela Peralta-Yahya, a metabolic engineer specializing in the production of advanced biofuels and commodity chemicals.

Carothers received this competitive award from ARPA-E’s Energy and Carbon Optimized Synthesis for the Bioeconomy (ECOSynBio) program, which focuses on developing advanced synthetic biology tools to engineer novel biomass conversion platforms and systems that are more efficient and produce less emissions than current fermentation processes widely used in biorefining.

The team’s initial goal is to develop a cell-free system to convert CO2 into malic acid. Malic acid can be made into a variety of chemicals, including maleic anhydride which had a 2018 market size of $2.77 billion and is used to make everything from plastics for cars and boats, to water treatment detergents, insecticides and fungicides, and pharmaceuticals. Malic acid – like most commodity chemicals – is made using fossil fuels, generating significant CO2 emissions in the process. Despite the urgent need to reduce our reliance on fossil fuels, alternative approaches have not yet been adopted due to lack of scalability and cost.

Instead of going through the inefficient and costly process of independently producing and purifying every enzyme needed to convert CO2 to malic acid, the team will use the cell’s own machinery – in the form of cell lysates – to synthesize scalable quantities of enzymes from DNA templates in a reaction mixture outside of the cell. To further optimize the bioconversion of CO2, researchers will engineer technologies to control the timing and expression level of different enzymes. This cell-free system will also include a biosynthetic module that regenerates cofactors – non-protein chemical compounds required for an enzyme’s catalytic activity – reducing the need for expensive cofactor supplements.

“Our platform will not only slash CO2 emissions compared to petroleum-based maleic anhydride production, but will actually sequester one ton of CO2 for each ton of product that it makes,” said Carothers. “The potential greenhouse gas savings here are significant.”

By enabling the industrial-scale, carbon-negative synthesis of high-value chemicals, this promising platform could help make a robust and sustainable bioeconomy a reality.

Read the full press release from DOE here.