Genomic and Physiological Signatures of Evolution in ANAMMOX Bacteria

ANAMMOX bacteria are a group of strictly anaerobic bacteria that offer a sustainable and energy-saving alternative to the conventional, energy-intensive aerobic bacteria-based fixed nitrogen removal technology from wastewater treatment plants. Since their discovery, research on ANAMMOX bacteria has expanded significantly, as reflected in the growing number of publications and patents. This review examines the evolutionary and physiological adaptations that have shaped these microorganisms, drawing from genomic and physiological studies. The distinct cellular architecture and membrane composition of ANAMMOX bacteria are discussed, alongside experimental literature that assesses their activity across various temperatures and pH conditions. Genomic analyses reveal significant differences between halophilic and non-halophilic ANAMMOX bacteria, with halophiles sharing a unique set of genes absent in other species. Analysis of proteomic investigations further demonstrates evolutionary divergence, with halophilic strains exhibiting a bias toward acidic amino acids, as shown through principal component analysis. Together, these insights provide a comprehensive view of ANAMMOX bacterial evolution, linking genomic diversity to physiological adaptation.