Research Insights

Bioproduction of sustainable fuels and materials, including aviation fuel, is a pressing and urgent issue. The knowledge and technologies developed in this proposal, mitigates climate change by creating carbon-neutral fuel. These biotechnologies increase rural economic development by creating a demand for sustainably grown plant biomass, decrease reliance on fossil carbon, and increase U.S. economic competitiveness. This project identifies long chain organic acid biosynthetic pathways in Megasphaera elsdenii, evaluates their activity under varying growth conditions, develops advanced genetic tools, and leverages those tools to improve the production of hexanoic acid, which is a sustainable aviation fuel precursor. The project is linked to a Women in Science program for 5th graders in the Clarke County public school system. As a new initiative, the project institutes joint training in STEM education for preservice student teachers, in conjunction with the University of Georgia College of Education. The metabolic diversity of microorganisms is only beginning to be understood and represents an untapped source of pathways to produce compounds that are difficult or impossible to engineer in existing model microbes. Megasphaera elsdenii, has the native ability to condense acetyl-CoA to efficiently generate C4 to C8 compounds at high flux and high yield, making it a compelling platform for the study of these pathways and to engineer the organism for production of fuels, chemicals and biomaterials. This project identifies long chain organic acid biosynthetic pathways in Megasphaera elsdenii, evaluates their activity under varying growth parameters, develops advanced genetic tools, and leverages those tools to improve flux to hexanoic acid, which is a sustainable aviation fuel precursor. A basic genetic toolset that allows gene deletion and heterologous expression is used to delete every nonessential gene predicted to be involved in chain elongation and analyze the impact on fermentation products to enable understanding of the genes responsible for each step. M. elsdenii has the rare ability to grow anaerobically on lactic acid as a carbon source as well as the ability to co-utilize lactic and acetic acids. The project involves physiological studies on wild type as well as mutational analysis to dissect the pathway(s) for anaerobic acetic acid utilization and lactic acid bioconversion. This project lays the foundation for engineering plant sugars to longer chain molecules and for alternate approaches to bioprocessing, such as the co-culture or sequential fermentation in which one organism converts sugars or biomass to lactic acid and an engineered M. elsdenii converts the lactic acid to a higher value product enabling strategies for a broad range of anaerobic microbial fermentations.

Funder: NSF

Amount: $899,897

PI: Janet Westpheling, Franklin College of Arts and Sciences, Department of Genetics