Genomic Science Program
U.S. Department of Energy | Office of Science | Biological and Environmental Research Program

Engineering Cupriavidus necator for Efficient Aerobic Conversion of Carbon Dioxide (CO2) to Fuels and Chemicals

Authors:

Engineering Cupriavidus necator for Efficient Aerobic Conversion of Carbon Dioxide (CO2) to Fuels and Chemicals

Institutions:

1Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory; 2Department of Bioengineering, Stanford University

Goals

This project broadly aims to establish platforms for in vivo and in vitro conversion of carbon dioxide (CO2) to fuels and chemicals through the advancement of genetic engineering and predictive biosystems design tools.

Abstract

The ecological and societal consequences of anthropogenic climate change necessitate the transition away from fossil fuels as a primary source of energy and chemical products. Biological processes utilizing microbes as a platform for synthesizing fuels and chemicals from ubiquitous, renewable carbon sources such as CO2 provide an opportunity to replace traditional industrial processes with sustainable, carbon-negative biomanufacturing. However, engineering chassis microbes to convert CO2 to product efficiently in scaled-up industrial bioprocesses remains challenging. This project broadly aims to establish platforms for in vivo and in vitro conversion of CO2 to fuels and chemicals through the advancement of genetic engineering and predictive biosystems design tools. At NREL, researchers are focused on: (1) developing new machine-learning tools for enzyme engineering and strategies for evaluating enzyme activity; and (2) improving the ability of the industrial host Cupriavidus necator to assimilate CO2 and produce fuel and nylon precursor molecules aerobically. In this poster, the team will highlight ongoing work establishing methods for screening native and engineered enzyme activity and discuss in-depth the efforts to engineer C. necator for efficient CO2 conversion. C. necator has a highly versatile and robust metabolism and can grow to high cell densities on a variety of carbon and energy sources, including CO2  and H2 as the sole source of carbon and energy. Researchers focus efforts on enabling C. necator to produce high titers of β-ketoadipate (βKA), a dicarboxylic acid that can be incorporated into high-performance nylons, and the terpenoids myrcene and bisabolene, which are precursors for sustainable aviation fuel and diesel blendstocks. Researchers will describe the work to identify which of the 70+ putative βKA-degradation enzymes in the C. necator genome are active in degrading βKA, and report progress on deleting these enzymes to engineer a strain that accumulates high amounts of βKA. Additionally, researchers will discuss work towards enabling high-titer terpenoid production via the addition of a heterologous synthesis pathway. Finally, researchers will briefly highlight efforts to streamline the genome of C. necator for efficient autotrophic growth in a bioreactor environment. Overall, this work will result in next-generation tools for biosystems design and advance C. necator as an industrial chassis for conversion of CO2 to value-added products in carbon-negative manufacturing processes.

Funding Information

Funding provided by the U.S. DOE Office of Science, BER program.