OPENAIRE OpenAire Crossref White Rose Research Online PubMed Central Environmental Microbiology Reports Open Access 2025-08-11 ABSTRACT <p> We investigate the potential for the globally distributed marine ammonia oxidising archaeon (AOA) Nitrosopumilus maritimus to oxidise iodide (I ￢ﾈﾒ ), with the aim of identifying a key driver of seawater iodate (IO 3 ￢ﾈﾒ ) renewal. Batch cultures of N. maritimus grew well in concentrations of 0.1 to 1￢ﾀﾉmM NH 4 + and from 0.0001 to 1￢ﾀﾉmM I ￢ﾈﾒ . There was near 100% conversion of ammonium to nitrite over an 8￢ﾀﾐday growth period. No loss of I ￢ﾈﾒ or production of IO 3 ￢ﾈﾒ was detected in cultures where I ￢ﾈﾒ was added, indicating that N. maritimus is unable to drive I ￢ﾈﾒ oxidation under the tested conditions. This contrasts with previous observations of I ￢ﾈﾒ oxidation by ammonium oxidising bacteria (AOB). We explore whether differences between the metabolism of AOA and AOB could explain their differing actions on I ￢ﾈﾒ . N. maritimus cultures grown with the equivalent IO 3 ￢ﾈﾒ concentrations also showed no reduction in [IO 3 ￢ﾈﾒ ]. In addition, the growth of the N. maritimus culture was unaffected by inorganic iodine concentrations over 1000 times higher than in ambient seawater, suggesting a resilience to high iodine. These results suggest that AOA might have very little role in inorganic iodine turnover in the global ocean. </p ammonium iodate archaea oxidation iodide Nitrosopumilus maritimus nitrification Research Article Alison L. Webb, Barbora Oudova‐Rivera, Martyn Ward, Lucy J. Carpenter, Laura E. Lehtovirta‐Morley, Rosie Chance, 2025-08-01 journalpaper ABSTRACT <p> We investigate the potential for the globally distributed marine ammonia oxidising archaeon (AOA) Nitrosopumilus maritimus to oxidise iodide (I ￢ﾈﾒ ), with the aim of identifying a key driver of seawater iodate (IO 3 ￢ﾈﾒ ) renewal. Batch cultures of N. maritimus grew well in concentrations of 0.1 to 1￢ﾀﾉmM NH 4 + and from 0.0001 to 1￢ﾀﾉmM I ￢ﾈﾒ . There was near 100% conversion of ammonium to nitrite over an 8￢ﾀﾐday growth period. No loss of I ￢ﾈﾒ or production of IO 3 ￢ﾈﾒ was detected in cultures where I ￢ﾈﾒ was added, indicating that N. maritimus is unable to drive I ￢ﾈﾒ oxidation under the tested conditions. This contrasts with previous observations of I ￢ﾈﾒ oxidation by ammonium oxidising bacteria (AOB). We explore whether differences between the metabolism of AOA and AOB could explain their differing actions on I ￢ﾈﾒ . N. maritimus cultures grown with the equivalent IO 3 ￢ﾈﾒ concentrations also showed no reduction in [IO 3 ￢ﾈﾒ ]. In addition, the growth of the N. maritimus culture was unaffected by inorganic iodine concentrations over 1000 times higher than in ambient seawater, suggesting a resilience to high iodine. These results suggest that AOA might have very little role in inorganic iodine turnover in the global ocean. </p The Ammonia Oxidising Archaeon Nitrosopumilus maritimus Does Not Alter Iodine Oxidation State in Oxic Seawater 10.1111/1758-2229.70168 https://doi.org/10.1111/1758-2229.70168 852993