RT Journal Article SR Electronic(1) A1 Taylor, Stephen C. A1 Dalton, Howard A1 Dow, Crawford S.YR 1981 T1 Ribulose-1,5-bisphosphate Carboxylase/Oxygenase and Carbon Assimilation in Methylococcus capsulatus (Bath) JF Microbiology, VO 122 IS 1 SP 89 OP 94 DO https://doi.org/10.1099/00221287-122-1-89 PB Microbiology Society, SN 1465-2080, AB Intact cells of chemostat-grown Methylococcus capsulatus (Bath) assimilated CO2 such that approximately 2.5% (w/w) of cell carbon arose from CO2 during growth with methane as carbon substrate. Radiolabelling studies suggested that CO2 was fixed by both ribulose-1,5-bisphosphate (RuBP) carboxylase and known heterotrophic mechanisms. The pattern of CO2 fixation was similar to that in heterotrophically grown autotrophs. Enzyme analysis suggested the presence of a complete Calvin cycle but attempts to grow the organism autotrophically were unsuccessful. A specific phosphoglycollate phosphatase, required for the metabolism of phosphoglycollate arising as a result of RuBP oxygenase activity, was present. The product of this reaction, glycollate, was further metabolized by reactions of the serine cycle, used for C1 assimilation in type II methylotrophs. The possession of this pathway explains both the presence of hydroxypyruvate reductase and the results of [14C]formate uptake reported by other workers. The relationship between RuBP carboxylase/oxygenase and net carbon assimilation is discussed., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-122-1-89