Photorespiration pathways in a chemolithoautotroph

摘要: Carbon fixation via the Calvin cycle is constrained by side activity of Rubisco with dioxygen, generating 2-phosphoglycolate. The metabolic recycling 2-phosphoglycolate, an essential process termed photorespiration, was extensively studied in photoautotrophic organisms, including plants, algae, and cyanobacteria, but remains uncharacterized chemolithoautotrophic bacteria. Here, we study photorespiration model chemolithoautotroph Cupriavidus necator (Ralstonia eutropha) characterizing proxy-process glycolate metabolism, performing comparative transcriptomics autotrophic growth under low high CO2 concentrations, testing phenotypes gene deletion strains at ambient CO2. We find that canonical plant-like C2 does not operate this bacterium instead bacterial-like glycerate pathway main photorespiratory pathway. Upon disruption pathway, oxidative which term malate cycle, supports photorespiration. In glyoxylate condensed acetyl-CoA to give malate, undergoes two decarboxylation steps regenerate acetyl-CoA. When both pathways are disrupted, abolished present bioinformatic data suggesting may support diverse This thus demonstrates a so-far unknown highlighting important diversity microbial carbon metabolism.