Tianhua Liao, Sishuo Wang, Hao Zhang, Eva E Stüeken, Haiwei Luo, Dating Ammonia-Oxidizing Bacteria with Abundant Eukaryotic Fossils (Dr. Luo's lab new publication)

Using Bayesian sequential dating anchored by eukaryotic fossil calibrations, we reveal that marine Gamma-proteobacterial ammonia oxidizers (Gamma-AOB) emerged 2.1–1.9 billion years ago, postdating the Great Oxidation Event (GOE). To reconcile earlier geochemical evidence of ammonia oxidation near the GOE, we propose that ancestral methanotrophs (Gamma-proteobacteria or Actinobacteria/Verrucomicrobia) or terrestrial archaea may have initiated nitrite production. Crucially, Gamma-AOB predated anaerobic ammonium-oxidizing (anammox) bacteria, implying aerobic nitrification supplied the nitrite required for anammox to thrive. These findings redefine the tempo of nitrogen redox cycling, suggesting marine nitrogen oxide pathways evolved later than previously hypothesized.Read the full study here: https://doi.org/10.1093/molbev/msae096  

 (Tianhua Liao, Sishuo Wang, Hao Zhang, Eva E Stüeken, Haiwei Luo, Dating Ammonia-Oxidizing Bacteria with Abundant Eukaryotic Fossils, Molecular Biology and Evolution, Volume 41, Issue 5, May 2024, msae096, https://doi.org/10.1093/molbev/msae096)