The taxonomic positions of members within the family
Pseudonocardiaceae
were assessed based on phylogenomic trees reconstructed using core-proteome and genome blast distance phylogeny approaches. The closely clustered genome sequences from the type strains of validly published names within the family
Pseudonocardiaceae
were analysed using overall genome-related indices based on average nucleotide identity, average amino acid identity and digital DNA–DNA hybridization values. The family
Pseudonocardiaceae
consists of the type genus
Pseudonocardia
, as well as the genera
Actinoalloteichus
,
Actinocrispum
,
Actinokineospora
,
Actinomycetospora
,
Actinophytocola
,
Actinopolyspora
,
Actinorectispora
,
Actinosynnema
,
Allokutzneria
, Allosaccharopolyspora gen. nov.,
Amycolatopsis
,
Bounagaea
,
Crossiella
,
Gandjariella
,
Goodfellowiella
,
Haloactinomyces
,
Haloechinothrix
,
Halopolyspora
, Halosaccharopolyspora gen. nov.,
Herbihabitans
,
Kibdelosporangium
,
Kutzneria
,
Labedaea
,
Lentzea
,
Longimycelium
,
Prauserella
,
Saccharomonospora
,
Saccharopolyspora
,
Saccharothrix
,
Salinifilum
,
Sciscionella
,
Streptoalloteichus
,
Tamaricihabitans
,
Thermocrispum
,
Thermotunica
and
Umezawaea
. The G+C contents of the
Pseudonocardiaceae
genomes ranged from 66.2 to 74.6 mol% and genome sizes ranged from 3.69 to 12.28 Mbp. Based on the results of phylogenomic analysis, the names Allosaccharopolyspora coralli comb. nov., Halosaccharopolyspora lacisalsi comb. nov. and Actinoalloteichus caeruleus comb. nov. are proposed. This study revealed that
Actinokineospora mzabensis
is a heterotypic synonym of
Actinokineospora spheciospongiae
,
Lentzea deserti
is a heterotypic synonym of
Lentzea atacamensis
,
Prauserella endophytica
is a heterotypic synonym of
Prauserella coralliicola
, and
Prauserella flava
and
Prauserella sediminis
are heterotypic synonyms of
Prauserella salsuginis
. This study addresses the nomenclature conundrums of
Actinoalloteichus cyanogriseus
and
Streptomyces caeruleus
as well as
Micropolyspora internatus
and
Saccharomonospora viridis
.
The taxonomic positions of three thermophilic actinomycetes isolated from arid soil samples were established by using a polyphasic approach. The organisms had chemical and morphological features that were consistent with their classification in the genus
Amycolatopsis
. 16S rRNA gene sequence data supported the classification of the isolates in the genus
Amycolatopsis
and showed that they formed distinct branches in the
Amycolatopsis methanolica
subclade. DNA–DNA relatedness studies between the isolates and their phylogenetic neighbours showed that they belonged to distinct genomic species. The three isolates were readily distinguished from one another and from the type strains of species classified in the
A. methanolica
subclade based on a combination of phenotypic properties and by genomic fingerprinting. Consequently, it is proposed that the three isolates be classified in the genus
Amycolatopsis
as representatives of Amycolatopsis granulosa sp. nov. (type strain GY307T = NCIMB 14709T = NRRL B-24844T), Amycolatopsis ruanii sp. nov. (type strain NMG112T = NCIMB 14711T = NRRL B-24848T) and Amycolatopsis thermalba sp. nov. (type strain SF45T = NCIMB 14705T = NRRL B-24845T).
The taxonomic position of a group of mesophilic actinomycetes isolated from arid Australian soils was determined using a polyphasic approach. The organisms shared chemical and morphological markers typical of members of the genus Amycolatopsis. They had identical 16S rRNA gene sequences and formed a distinct phyletic line in the Amycolatopsis mediterranei clade, being most closely related to A. mediterranei. In addition, they shared a range of phenotypic properties that distinguished them from representatives of all of the species classified in this clade. The combined genotypic and phenotypic data indicate that the strains merit species status within the genus Amycolatopsis. The name proposed for the novel species is Amycolatopsis australiensis sp. nov.; the type strain is GY048T (=DSM 44671T=NCIMB 14142T).