The exchange of 18O between H218O and exogeneously added 15N16O-2 which occurs during oxidation of ammonia by Nitrosomonas is shown to occur one oxygen at a time. Conditions in which the exchange is diminished (notably the presence of 14NO-2 and CCCP) allowed demonstration that water and dioxygen are each the source of one oxygen in nitrite produced from 15NH3. The nitrate produced in the presence of 18O2 consisted of 67 and 0% 15N18O16O- and 15N18O18O-, respectively. Analysis was made using the 18O-isotope shift in 15N-NMR. © 1983.
Andersson, K. K., & Hooper, A. B. (1983). O2 and H2O are each the source of one O in NO-2 produced from NH3 by Nitrosomonas: 15N-NMR evidence. FEBS Letters, 164(2), 236–240. https://doi.org/10.1016/0014-5793(83)80292-0