Actinobacteria Stackebrandt et al. 1997 emend. Nouioui et al. 2018 non Actinobacteria Goodfellow 2021 Actinobacteria Stackebrandt et al. 1997 emend. Nouioui et al. 2018 non Actinobacteria Goodfellow 2021 Universal Root Woese et al. 1990 Bacteria (None 2015) Woese et al. 1990 Actinobacteria (sic) Goodfellow 2021 non Actinobacteria Stackebrandt et al. 1997 Actinomycetota corrig. Goodfellow 2021 Actinobacteriota corrig. Goodfellow 2021 Actinobacteria Stackebrandt et al. 1997 emend. Nouioui et al. 2018 non Actinobacteria Goodfellow 2021 Actinobacteria (sic) Goodfellow 2021 non Actinobacteria Stackebrandt et al. 1997 Actinomycetota corrig. Goodfellow 2021 Actinobacteriota corrig. Goodfellow 2021 Rubrobacteria Suzuki 2013 emend. Foesel et al. 2016 Coriobacteriia König 2013 emend. Gupta et al. 2013 Acidimicrobiia Norris 2013 Thermoleophilia Suzuki and Whitman 2013 emend. Foesel et al. 2016 Actinomycetes Krasil'nikov 1949 (Approved Lists 1980) Nitriliruptoria Ludwig et al. 2013 Actinomycetia (Stackebrandt et al. 1997) Salam et al. 2020 pro synon. Actinomycetes Krasil'nikov 1949 (Approved Lists 1980) Syntrophaliphaticia corrig. Liu et al. 2020 Syntraliphaticia (sic) Liu et al. 2020 Incertae sedis 722 Merino et al. 2020 Actinobacteridae Stackebrandt et al. 1997 emend. Zhi et al. 2009 Solirubrobacterales Reddy and Garcia-Pichel 2009 emend. Foesel et al. 2016 Gaiellales Albuquerque et al. 2012 emend. Foesel et al. 2016 Geodermatophilales Sen et al. 2014 Nakamurellales Sen et al. 2014 Frankiales Sen et al. 2014 Micromonosporales (Stackebrandt et al. 1997) Genilloud 2015 Actinopolysporales (Zhi et al. 2009) Goodfellow and Trujillo 2015 Catenulisporales (Cavaletti et al. 2006) Donadio et al. 2015 Kineosporiales (Zhi et al. 2009) Kämpfer 2015 Streptosporangiales Goodfellow 2015 emend. Nouioui et al. 2018 Pseudonocardiales Labeda and Goodfellow 2015 Corynebacteriales Goodfellow and Jones 2015 emend. Nouioui et al. 2018 Propionibacteriales (Rainey et al. 1997) Patrick and McDowell 2015 emend. Nouioui et al. 2018 Glycomycetales Labeda 2015 Jiangellales Tang et al. 2015 Acidimicrobidae Stackebrandt et al. 1997 emend. Zhi et al. 2009 Rubrobacteridae Rainey et al. 1997 emend. Zhi et al. 2009 Coriobacteridae Stackebrandt et al. 1997 emend. Zhi et al. 2009 Sphaerobacteridae Stackebrandt et al. 1997 Incertae sedis 175 None 2015 Acidothermales Sen et al. 2014 Streptomycetales Kämpfer 2012 Actinomarinidae Ghai et al. 2013 Nanopelagicales Neuenschwander et al. 2018 Goodfellow M. Trujillo M.E. Goodfellow M. Kämpfer P. Busse H.-J. Trujillo M.E. Suzuki K.-I. Ludwig W. Whitman W.B. Order II. Actinopolysporales ord. nov. 2012 5, Part A 2 162 Bergey's Manual of Systematic Bacteriology Springer New York Albuquerque L. França L. Rainey F.A. Schumann P. Nobre M.F. da Costa M.S. Gaiella occulta gen. nov., sp. nov., a novel representative of a deep branching phylogenetic lineage within the class Actinobacteria and proposal of Gaiellaceae fam. nov. and Gaiellales ord. nov. 2011 34 8 595 599 Systematic and Applied Microbiology Syst Appl Microbiol 0723-2020 10.1016/j.syapm.2011.07.001 21899973 Labeda D.P. Goodfellow M. Goodfellow M. Kämpfer P. Busse H.-J. Trujillo M.E. Suzuki K.-I. Ludwig W. Whitman W.B. Order XIII. Pseudonocardiales ord. nov. 2012 5, Part B 2 1301 Bergey's Manual of Systematic Bacteriology Springer New York Sen A. Daubin V. Abrouk D. Gifford I. Berry A.M. Normand P. Phylogeny of the class Actinobacteria revisited in the light of complete genomes. The orders 'Frankiales' and Micrococcales should be split into coherent entities: proposal of Frankiales ord. nov., Geodermatophilales ord. nov., Acidothermales ord. nov. and Nakamurellales ord. nov. 2014 64 11 3821 3832 International Journal of Systematic and Evolutionary Microbiology Int J Syst Evol Microbiol 1466-5026 1466-5034 10.1099/ijs.0.063966-0 25168610 Kämpfer P. Goodfellow M. Kämpfer P. Busse H.-J. Trujillo M.E. Suzuki K.-I. Ludwig W. Whitman W.B. Order XIV. Streptomycetales ord. nov. 2012 5, Part B 2 1446 Bergey's Manual of Systematic Bacteriology Springer New York Patrick S. McDowell A. Goodfellow M. Kämpfer P. Busse H.-J. Trujillo M.E. Suzuki K.-I. Ludwig W. Whitman W.B. Order XII. Propionibacteriales ord. nov. 2012 5, Part B 2 1137 Bergey's Manual of Systematic Bacteriology Springer New York Kämpfer P. Goodfellow M. Kämpfer P. Busse H.-J. Trujillo M.E. Suzuki K.-I. Ludwig W. Whitman W.B. Order IX. Kineosporiales ord. nov. 2012 5, Part A 2 561 Bergey's Manual of Systematic Bacteriology Springer New York Meklat A. Bouras N. Mokrane S. Zitouni A. Schumann P. Spröer C. Klenk H.-P. Sabaou N. Bounagaea algeriensis gen. nov., sp. nov., an extremely halophilic actinobacterium isolated from a Saharan soil of Algeria 2015 108 473 482 Antonie van Leeuwenhoek 0003-6072 1572-9699 10.1007/s10482-015-0500-9 26050246 Genilloud O. Goodfellow M. Kämpfer P. Busse H.-J. Trujillo M.E. Suzuki K.-I. Ludwig W. Whitman W.B. Order XI. Micromonosporales ord. nov. 2012 5, Part B 2 1035 Bergey's Manual of Systematic Bacteriology Springer New York Donadio S. Cavaletti L. Monciardini P. Goodfellow M. Kämpfer P. Busse H.-J. Trujillo M.E. Suzuki K.-I. Ludwig W. Whitman W.B. Order IV. Catenulisporales ord. nov. 2012 5, Part A 2 225 Bergey's Manual of Systematic Bacteriology Springer New York Ghai R. Mizuno C.M. Picazo A. Camacho A. Rodriguez-Valera F. Metagenomics uncovers a new group of low GC and ultra-small marine Actinobacteria. 2013 3 2471 2471 Scientific Reports Sci Rep 2045-2322 10.1038/srep02471 23959135 Goodfellow M. Jones A.L. Goodfellow M. Kämpfer P. Busse H.-J. Trujillo M.E. Suzuki K.-I. Ludwig W. Whitman W.B. Order V. Corynebacteriales ord. nov. 2012 5, Part A 2 235 243 Bergey's Manual of Systematic Bacteriology Springer New York Goodfellow M. Goodfellow M. Kämpfer P. Busse H.-J. Trujillo M.E. Suzuki K.-I. Ludwig W. Whitman W.B. Order XV. Streptosporangiales ord. nov. 2012 5, Part B 2 1805 Bergey's Manual of Systematic Bacteriology Springer New York Neuenschwander S.M. Ghai R. Pernthaler J. Salcher M.M. Microdiversification in genome-streamlined ubiquitous freshwater Actinobacteria. 2018 12 1 185 198 The ISME Journal ISME J 1751-7362 1751-7370 10.1038/ismej.2017.156 29027997 Goodfellow M. Goodfellow M. Kämpfer P. Busse H.-J. Trujillo M.E. Suzuki K.-I. Ludwig W. Whitman W.B. Class I. Actinobacteria 2012 5, Part A 2 34 Bergey's Manual of Systematic Bacteriology Springer New York Stackebrandt E. Rainey F.A. Ward-Rainey N.L. Proposal for a new hierarchic classification system, Actinobacteria classis nov. 1997 47 2 479 491 International Journal of Systematic Bacteriology Int J Syst Bacteriol 0020-7713 10.1099/00207713-47-2-479 Reddy G.S.N. Garcia-Pichel F. Description of Patulibacter americanus sp. nov., isolated from biological soil crusts, emended description of the genus Patulibacter Takahashi et al. 2006 and proposal of Solirubrobacterales ord. nov. and Thermoleophilales ord. nov. 2009 59 1 87 94 International Journal of Systematic and Evolutionary Microbiology Int J Syst Evol Microbiol 1466-5026 1466-5034 10.1099/ijs.0.64185-0 19126730 Stackebrandt et al. 1997 did not declare a nomenclatural type for this taxon. It was eventually replaced by Actinomycetia. Actinomycetia (Stackebrandt et al. 1997) Salam et al. 2020 pro synon. Actinomycetes Krasil'nikov 1949 (Approved Lists 1980) Actinomycetes Krasil'nikov 1949 (Approved Lists 1980) Nouioui I. Carro L. García-López M. Meier-Kolthoff J.P. Woyke T. Kyrpides N.C. Pukall R. Klenk H.-P. Goodfellow M. Göker M. Genome-Based Taxonomic Classification of the Phylum Actinobacteria 2018 9 2007 2007 Frontiers in Microbiology Front. Microbio. 1664-302X 10.3389/fmicb.2018.02007 30186281 Salam N. Jiao J.-Y. Zhang X.-T. Li W.-J. Update on the classification of higher ranks in the phylum Actinobacteria. 2020 70 2 1331 1355 International Journal of Systematic and Evolutionary Microbiology Int J Syst Evol Microbiol 1466-5026 1466-5034 10.1099/ijsem.0.003920 31808738 Euzéby J.P. Tindall B.J. Nomenclatural type of orders: corrections necessary according to Rules 15 and 21a of the Bacteriological Code (1990 Revision), and designation of appropriate nomenclatural types of classes and subclasses. Request for an opinion. 2001 51 2 725 727 International Journal of Systematic and Evolutionary Microbiology Int J Syst Evol Microbiol 1466-5026 1466-5034 10.1099/00207713-51-2-725 11321122 Judicial Commission of the International Committee on Systematics of Prokaryotes Names at the rank of class, subclass and order, their typification and current status: Supplementary information to Opinion 79. 2014 64 10 3599 3602 International Journal of Systematic and Evolutionary Microbiology Int J Syst Evol Microbiol 1466-5026 1466-5034 10.1099/ijs.0.069310-0 25288668 Stackebrandt E. Rainey F.A. Ward-Rainey N.L. Proposal for a new hierarchic classification system, Actinobacteria classis nov. 1997 47 2 479 491 International Journal of Systematic Bacteriology Int J Syst Bacteriol 0020-7713 10.1099/00207713-47-2-479 Zhi X.Y. Li W.J. Stackebrandt E. An update of the structure and 16S rRNA gene sequence-based definition of higher ranks of the class Actinobacteria, with the proposal of two new suborders and four new families and emended descriptions of the existing higher taxa. 2009 59 3 589 608 International Journal of Systematic and Evolutionary Microbiology Int J Syst Evol Microbiol 1466-5026 1466-5034 10.1099/ijs.0.65780-0 19244447 This class is illegitimate because no nomenclatural type was designated. However, at this time no suitable replacement taxon has been published. Opinion 79 (Supplement) states, "Actinobacteria Stackebrandt et al. 1997, a name proposed without the designation of a type to replace the name Actinomycetes Krassilnikov 1949, contravening Rules 15 (Table 2), 22, 27 (3), 51b and 55 of the International Code of Nomenclature of Bacteria (Lapage et al. 1992)."