There is a need to clarify relationships within the actinobacterial genus Micromonospora, the type genus of the family Micromonosporaceae, given its biotechnological and ecological importance. Here, draft genomes of 40 Micromonospora type strains and two non-type strains are made available through the Genomic Encyclopedia of Bacteria and Archaea project and used to generate a phylogenomic tree which showed they could be assigned to well supported phyletic lines that were not evident in corresponding trees based on single and concatenated sequences of conserved genes. DNA G+C ratios derived from genome sequences showed that corresponding data from species descriptions were imprecise. Emended descriptions include precise base composition data and approximate genome sizes of the type strains. antiSMASH analyses of the draft genomes show that micromonosporae have a previously unrealised potential to synthesize novel specialized metabolites. Close to one thousand biosynthetic gene clusters were detected, including NRPS, PKS, terpenes and siderophores clusters that were discontinuously distributed thereby opening up the prospect of prioritising gifted strains for natural product discovery. The distribution of key stress related genes provide an insight into how micromonosporae adapt to key environmental variables. Genes associated with plant interactions highlight the potential use of micromonosporae in agriculture and biotechnology.

A novel actinobacterial strain, designated 13K301^T, was isolated from a soil sample collected from the Karakum Desert, Turkmenistan. The taxonomic position of strain 13K301^T was revealed by using a polyphasic approach. On the basis of 16S rRNA gene sequence analysis, strain 13K301^T belongs to the genus Streptomyces and had highest sequence similarity to ‘Streptomyces qaidamensis’ S10^T (99.2 %), Streptomyces flavovariabilis NRRL B-16367^T (98.9 %) and Streptomyces phaeoluteigriseus DSM 41896^T (98.8 %), but the strain formed a distinct clade in the phylogenetic tree. The DNA–DNA relatedness and average nucleotide identity values as well as evolutionary distances based on multilocus (atpD, gyrB, recA, rpoB and trpB) sequences between strain 13K301^T and closely related type strains were significantly lower than the recommended threshold values. The cell wall contained ll-diaminopimelic acid and the whole-cell hydrolysates were glucose and ribose. Diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and phosphatidylinositol were determined as the predominant polar lipids. The major menaquinones were identified as MK-9(H₈) and MK-9(H₆). On the basis of these genotypic and phenotypic data, it is proposed that strain 13K301^T should be classified as representative of a novel species of the genus Streptomyces , for which the name Streptomyces cahuitamycinicus sp. nov. is proposed. The type strain is 13K301^T (=DSM 106873^T=KCTC 49110^T). In addition, the whole genome-based comparisons as well as the multilocus sequence analysis revealed that the type strains of Streptomyces galilaeus and Streptomyces bobili belong to a single species. It is, therefore, proposed that S. galilaeus be recognised as a heterotypic synonym of S. bobili for which an emended description is given.

Five actinobacteria isolates, KC201T, KC401, KC310T, KC712T and 6K102T, were recovered from the Karakum Desert during an investigation of novel actinobacteria with biotechnological potential. A polyphasic approach confirmed the affiliation of the strains to the genus Nonomuraea . The strains showed chemotaxonomic and morphological properties consistent with their classification in the genus Nonomuraea . Furthermore, these strains clearly distinguished and formed well supperted clades in phylogenetic and phylogenomic trees. Low ANI and dDDH values and distinguishing phenotypic properties between isolates KC201T, KC310T, KC712T and 6K102T showed that these strains belonged to novel Nonomuraea species, the names proposed for these taxa are Nonomuraea deserti sp. nov., Nonomuraea diastatica sp. nov., Nonomuraea longispora sp. nov. and Nonomuraea mesophila sp. nov., with the type strains KC310T (=CGMCC 4.7331T =DSM 102919T =KCTC 39774T), KC712T (=CGMCC 4.7334T =DSM 102925T =KCTC 39776), KC201T (=CGMCC 4.7339T =DSM 102917T =KCTC 39781T) and 6K102T (=CGMCC 4.7541T =JCM 32916), respectively.