Notification that new names and new combinations have appeared in volume 50, part 2, of the IJSEM.

This article is a notification list published in the International Journal of Systematic and Evolutionary Microbiology, documenting new bacterial and archaeal names and taxonomic combinations that appeared in volume 50, part 2 of the journal. The list includes 63 newly proposed species names, amended genus descriptions, and reclassified species transferred to new genera. Notable new organisms described include Sphingomonas wittichii, multiple Geobacillus species (reclassified from Bacillus), Mycoplasma species from animals, and various specialized bacteria such as thermophilic and alkaliphilic organisms. Several entries include nomenclatural corrections, indicated by "corrig." designations. The notification serves an administrative function in microbial taxonomy, providing researchers with a comprehensive reference of validly published names according to priority rules based on journal page numbers. This procedure was established by the Judicial Commission to assist the bacteriological community in recognizing and tracking new taxonomic nomenclature.

Key findings

• Sixty-three new bacterial and archaeal names were validly published in IJSEM volume 50, part 2
• Multiple thermophilic and thermoacidophilic genera were described, including new Geobacillus species reclassified from Bacillus
• Several nomenclatural corrections were made to previously published names to ensure accuracy
• New specialized bacteria were identified, including alkaliphilic sulfur-oxidizing bacteria and mycoplasmas from animal hosts
• The notification list serves as a systematic registry of validly published names assigned according to journal page priority