This notification list documents new bacterial and archaeal names and taxonomic combinations formally published in volume 51, part 3 of the International Journal of Systematic and Evolutionary Microbiology (IJSEM) in 2001. The list includes validly published new species names, new genus names, and new combinations where previously named organisms were reclassified into different genera. Notable inclusions are Candidatus species designations for unculturable organisms like Mycoplasma haemofelis and related hemotropic bacteria, new Corynebacterium and Actinomyces species, Sporosarcina species reclassified from Bacillus, new Legionella species, halophilic Natrialba species, and several other clinically or environmentally relevant bacteria. The list also documents nomenclatural corrections and subspecies designations created automatically under bacteriological nomenclature rules. Each entry identifies the proposing authors and indicates whether names represent entirely new descriptions, combinations reclassifying existing organisms, or corrections to previously published names.

Key findings

• The notification documents 60+ new bacterial and archaeal taxa validly published in IJSEM volume 51, part 3, including new species, genera, and combinations
• Multiple Candidatus species for unculturable organisms were formally proposed, including hemotropic Mycoplasma species previously classified as Haemobartonella and Eperythrozoon
• Several previously named bacteria were reclassified into new genera, such as Sporosarcina species moved from Bacillus and Raoultella species separated from Klebsiella
• Nomenclatural corrections and automatic subspecies designations were documented according to bacteriological nomenclature rules