Evidence for the Novel Metabolic Pathway of Ralstonia eutropha H16 to Metabolize L‐ascorbate Ryan Joyce, Tyler Stack, Michael Carter

L‐Ascorbate is an antioxidant produced by many eukaryotes and is available for microbial organisms in eukaryotic detritus. Ralstonia eutropha H16, a soil bacterium that is studied due to its extensive metabolism and bioplastic producing capabilities, can use L‐ascorbate via a metabolic pathway that is different from the known pathways of Escherichia coli and plants. Transcript levels were measured in L‐ascorbate‐grown Ralstonia eutropha H16 and compared to transcript levels of succinate‐ and fructose‐grown Ralstonia eutropha H16. Genes with a larger than 50‐fold upregulation during L‐ascorbate growth were investigated. A BLAST search suggested that the proteins encoded by the genes of interest in Ralstonia eutropha H16 differ from enzymes of the Escherichia coli L‐ascorbate metabolic pathway. Ralstonia eutropha H16 does not convert L‐ascorbate into L‐threonate and oxalate, as plants do. Genes of interest, h16_rs15015 and h16_rs19815, were deleted. The resultant mutants do not grow with L‐ascorbate. The deletion of specific metabolic genes allows us to better understand their function and importance to the cell's metabolism, furthering our understanding of how different enzymatic metabolic pathways function in nature.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.