Nitrobacter Winogradsky 1892 emend. Watson 1974 (Approved Lists 1980) Nitrobacter winogradskyi Winslow et al. 1917 (Approved Lists 1980) emend. Hördt et al. 2020 Universal Root Woese et al. 1990 Bacteria (None 2015) Woese et al. 1990 Proteobacteria (sic) Garrity et al. 2021 Pseudomonadota corrig. Garrity et al. 2021 Alphaproteobacteriota (sic) Garrity et al. 2021 Alphaproteobacteria Garrity et al. 2006 Hyphomicrobiales Douglas 1957 (Approved Lists 1980) emend. Hördt et al. 2020 Nitrobacteraceae Buchanan 1917 (Approved Lists 1980) emend. Hördt et al. 2020 Nitrobacter Winogradsky 1892 emend. Watson 1974 (Approved Lists 1980) Nitrobacteraceae Buchanan 1917 (Approved Lists 1980) emend. Hördt et al. 2020 Nitrosomonas Winogradsky 1892 (Approved Lists 1980) emend. Campbell et al. 2011 Nitrosospira Winogradsky and Winogradsky 1933 (Approved Lists 1980) emend. Head et al. 1993 Nitrosococcus Winogradsky 1892 (Approved Lists 1980) emend. Wang et al. 2016 Afipia Brenner et al. 1992 emend. La Scola et al. 2002 Blastobacter Zavarzin 1961 (Approved Lists 1980) emend. Sly 1985 Bradyrhizobium Jordan 1982 Agromonas Ohta and Hattori 1985 Pseudolabrys Kämpfer et al. 2006 emend. Jung et al. 2022 Pseudorhodoplanes Tirandaz et al. 2015 Rhodopseudomonas Czurda and Maresch 1937 (Approved Lists 1980) emend. Imhoff et al. 1984 Tardiphaga De Meyer et al. 2012 Variibacter Kim et al. 2014 Rhodoplanes Hiraishi and Ueda 1994 Undibacter Jung et al. 2022 Nitrobacter vulgaris Bock et al. 2001 Nitrobacter winogradskyi Winslow et al. 1917 (Approved Lists 1980) emend. Hördt et al. 2020 Nitrobacter hamburgensis Bock et al. 2001 Nitrobacter sp. None 2015 Nitrobacter alkalicus Sorokin et al. 1999 Garrity G.M. Bell J.A. Lilburn T. Garrity G.M. Brenner D.J. Krieg N.R. Staley J.T. Family VII. Bradyrhizobiaceae fam. nov. 2005 2, Part C 2 438 Bergey's Manual of Systematic Bacteriology Springer New York 0387241450 Bock E. Sundermeyer-Klinger H. Stackebrandt E. New facultative lithoautotrophic nitrite-oxidizing bacteria. 1983 136 281 284 Archives of Microbiology Arch Microbiol 0302-8933 1432-072X 10.1007/BF00425217 Sorokin D.Y. Muyzer G. Brinkhoff T. Kuenen J.G. Jetten M.S.M. Isolation and characterization of a novel facultatively alkaliphilic Nitrobacter species, N. alkalicus sp. nov. 1998 170 345 352 Archives of Microbiology Arch Microbiol 0302-8933 1432-072X 10.1007/s002030050652 9818354 Winslow C.E. Broadhurst J. Buchanan R.E. Krumwiede C. Rogers L.A. Smith G.H. The Families and Genera of the Bacteria: Preliminary Report of the Committee of the Society of American Bacteriologists on Characterization and Classification of Bacterial Types. 1917 2 5 505 66 Journal of Bacteriology J Bacteriol 0021-9193 1098-5530 16558764 Bock E. Koops H.P. Moller U.C. Rudert M. A new facultatively nitrite oxidizing bacterium, Nitrobacter vulgaris sp. nov. 1990 153 105 110 Archives of Microbiology Arch Microbiol 0302-8933 1432-072X Hördt A. García-López M. Meier-Kolthoff J.P. Tindall B.J. Weinhold L.-M. Gronow S. Kyrpides N. Woyke T. Schleuning M. Göker M. Analysis of 1,000+ Type-Strain Genomes Substantially Improves Taxonomic Classification of Alphaproteobacteria 2020 11 468 Frontiers in Microbiology Front. Microbio. 1664-302X 10.3389/fmicb.2020.00468 32373076 No reference is available 2015 Buchanan 1917 placed Nitrobacter in the Nitrobacteraceae. This genus was included in the Bradyrhizobiaceae by Garrity et al. 2005 and later transferred back to Nitrobacteraceae by Hördt et al. 2020.