Actinobacteria Stackebrandt et al. 1997
General information
Description and emendation
The class is definable in phylogenetic terms as derived from the analysis of macromolecules of universally homologous functions. Strains of the class Actinobacteria can consistently be recovered as members of the same phylogenetic lineage, revealing >80% 16S rDNA/rRNA sequence similarity among each other, and the presence of the following signature nucleotides in the 16S rDNA/rRNA an A residue at position 906 and either an A or a C residue at position 955 (except for members of the subclasses Rubrubacteridae and Sphaerobacteridae [which show U residues at these positions]), The intraclass relatedness reveals the presence of six phylogenetically distinct lineages which are consistently recovered from phylogenetic analyses (42). These lineages are described as orders. The 16S rDNA/rRNA signatures defining the higher taxa are based on the available 16S rDNA/rRNA sequences of the type strains of type species of the genera. As certain taxa contain only one or two species, the pattern of signature nucleotides may need to be modified as new species are added to the respective genera.
1: The original proposal of the class 'Actinobacteria' (Stackebrandt et al., 1997) did not designate a type order hence this name is not validly published under Rule 27 of the International Code of Nomenclature of Prokaryotes (Parker et al., 2015). However, since this name is in common currency it is used here. The type order is likely to be Actinomycetales Buchanan 1917 162AL emend. Zhi et al. 2009, 594, a move that would require the approval of the Judicial Commission. Actinobacteria show amazingly diverse morphologies that range from cocci (e.g., Lapillicoccus and Micrococcus), short rods (e.g., Mycobacterium and Tropheryma), irregular rods (e.g., Arcanobacterium and Cellulomonas), rods and cocci (e.g., Arthrobacter and Brevibacterium) to mycelia that fragment into coccoid and rod-like forms (e.g., Nocardia and Promicromonospora). Others show more pronounced morphological differentiation which ranges from extensively branched substrate hyphae that carry spores (e.g., Catellatospora and Micromonospora) or spores vesicles (e.g., Actinoplanes and Dactylosporangium) to strains that produce a stable branched substrate mycelium which bears aerial hyphae which differentiate into long chains of spores (e.g., Nonomuraea and Streptomyces) or into spore vesicles (e.g., Planotetraspora and Streptosporangium). In general, spores are non-motile though ones released from spore vesicles tend to be motile.
Subdivision(s)
MID | Name | Rank | Taxon ID |
---|---|---|---|
MSG084083 | 'Actinobacteria bacterium ' | Species | |
MSG075142 | 'Actinobacteria bacterium' | Species | |
MSG100069 | 'Actinobacteria sp.' | Species | |
MSG072603 | 'Actinobacteriota bacterium' | Species | |
MSG073182 | 'Actinobacterium bacterium' | Species | |
MSG100050 | 'Actinomycetia sp.' | Species | |
MSG071659 | 'Candidatus Actinobacteria Cadiz_LYX9' | Species | |
MSG086799 | 'Nanopelagicus sp000383815' | Species | |
MSG086752 | 'UBA3012 sp002346305' | Species | |
M02020201 | Acidothermales | Order | 1643683 |
M02020202 | Actinomycetales | Order | 2037 |
M02020203 | Actinopolysporales | Order | 622450 |
M02020204 | Bifidobacteriales | Order | 85004 |
M020202000001 | Bounagaea | Genus | 1931219 |
M02020205 | Catenulisporales | Order | 414714 |
M02020206 | Corynebacteriales | Order | 85007 |
M02020219 | Cryptosporangiales | Order | 2495577 |
M02020207 | Frankiales | Order | 85013 |
M02020208 | Geodermatophilales | Order | 1643682 |
M02020209 | Glycomycetales | Order | 85014 |
M0202020001 | Jatrophihabitantaceae | Family | |
M02020210 | Jiangellales | Order | 1217098 |
M02020211 | Kineosporiales | Order | 622452 |
M02020212 | Micrococcales | Order | 85006 |
M02020213 | Micromonosporales | Order | 85008 |
M02020214 | Nakamurellales | Order | 1643684 |
M02020215 | Propionibacteriales | Order | 85009 |
M02020216 | Pseudonocardiales | Order | 85010 |
M02020220 | Sporichthyales | Order | 2495578 |
M02020217 | Streptomycetales | Order | 85011 |
M02020218 | Streptosporangiales | Order | 85012 |