|Taxonomy Citation ID||Reference|
( 2012 )
Arthrobacter cupressi sp. nov., an actinomycete isolated from the rhizosphere soil of Cupressus sempervirens.
PMID : 22228666 DOI : 10.1099/ijs.0.036889-0
An actinobacterial strain, designated D48(T), was isolated from the rhizosphere soil of a cypress tree collected from Mianyang in Sichuan province, China. The strain was Gram-stain-positive, catalase-positive, oxidase-negative and non-motile, with lysine as the peptidoglycan diagnostic diamino acid and acetyl as the peptidoglycan acyl type. The predominant menaquinone was MK-9(H(2)); small amounts of MK-7(H(2)), MK-10(H(2)) and MK-6 were also present. The major fatty acids were anteiso-C(15:0), anteiso-C(17:0) and iso-C(16:0). The isolate underwent a rod-coccus morphological cycle, had a high DNA G+C content, was aerobic and grew between 12 and 37 �XC (optimum, 28 �XC). On the basis of the phenotypic and chemotaxonomic analyses, 16S rRNA gene sequence comparisons and DNA-DNA hybridization data, the isolate represents a novel species of the genus Arthrobacter, for which the name Arthrobacter cupressi sp. nov. is proposed. The type strain is D48(T) (=DSM 24664(T)=CGMCC 1.10783(T)).
( 2018 )
Genome-Based Taxonomic Classification of the Phylum Actinobacteria.
PMID : 30186281 DOI : 10.3389/fmicb.2018.02007 PMC : PMC6113628
The application of phylogenetic taxonomic procedures led to improvements in the classification of bacteria assigned to the phylum Actinobacteria but even so there remains a need to further clarify relationships within a taxon that encompasses organisms of agricultural, biotechnological, clinical, and ecological importance. Classification of the morphologically diverse bacteria belonging to this large phylum based on a limited number of features has proved to be difficult, not least when taxonomic decisions rested heavily on interpretation of poorly resolved 16S rRNA gene trees. Here, draft genome sequences of a large collection of actinobacterial type strains were used to infer phylogenetic trees from genome-scale data using principles drawn from phylogenetic systematics. The majority of taxa were found to be monophyletic but several orders, families, and genera, as well as many species and a few subspecies were shown to be in need of revision leading to proposals for the recognition of 2 orders, 10 families, and 17 genera, as well as the transfer of over 100 species to other genera. In addition, emended descriptions are given for many species mainly involving the addition of data on genome size and DNA G+C content, the former can be considered to be a valuable taxonomic marker in actinobacterial systematics. Many of the incongruities detected when the results of the present study were compared with existing classifications had been recognized from 16S rRNA gene trees though whole-genome phylogenies proved to be much better resolved. The few significant incongruities found between 16S/23S rRNA and whole genome trees underline the pitfalls inherent in phylogenies based upon single gene sequences. Similarly good congruence was found between the discontinuous distribution of phenotypic properties and taxa delineated in the phylogenetic trees though diverse non-monophyletic taxa appeared to be based on the use of plesiomorphic character states as diagnostic features.