A novel non-motile, Gram-staining-negative, yellow-pigmented bacterium, designated AG13^T, isolated from a rain water pond at a plant nursery in Spain and characterized as a plant-growth-promoting bacterium, was investigated to determine its taxonomic status. The isolate grew best over a temperature range of 15–40 °C, at pH 5.0–8.0 and with 0–4 % (w/v) NaCl. Chemotaxonomic and molecular characteristics of the isolate matched those described for members of the genus Chryseobacterium . The DNA G+C content of the novel strain was 37.2 mol%. The strain had a polyamine pattern withsym-homospermidine as the major compound and produced flexirubin-type pigments. MK-6 was the dominant menaquinone and the major cellular fatty acids were iso-C_15 : 0, C_17 : 1ω9cand iso-C_17 : 03-OH. The main polar lipids were phosphatidylethanolamine, aminolipids and several unidentified lipids. The 16S rRNA gene showed 92.0–97.2 % sequence similarity with those of the members of the genus Chryseobacterium . Based on chemotaxonomic and phenotypic traits, and DNA–DNA hybridizations with the type strains of the most closely related species, the isolate is proposed to represent a novel species,Chryseobacterium hispalense, type strain AG13^T( = DSM 25574^T = CCUG 63019^T). Emended descriptions of the species Chryseobacterium defluvii , Chryseobacterium indologenes , Chryseobacterium wanjuense and Chryseobacterium gregarium are also provided.

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.

Geodermatophilaceae (order Geodermatophilales, class Actinobacteria) form a comparatively isolated family within the phylum Actinobacteria and harbour many strains adapted to extreme ecological niches and tolerant against reactive oxygen species. Clarifying the evolutionary history of Geodermatophilaceae was so far mainly hampered by the insufficient resolution of the main phylogenetic marker in use, the 16S rRNA gene. In conjunction with the taxonomic characterisation of a motile and aerobic strain, designated YIM M13156T and phylogenetically located within the family, we here carried out a phylogenetic analysis of the genome sequences now available for the type strains of Geodermatophilaceae and re-analysed the previously assembled phenotypic data. The results indicated that the largest genus, Geodermatophilus, is not monophyletic, hence the arrangement of the genera of Geodermatophilaceae must be reconsidered. Taxonomic markers such as polar lipids and fatty-acids profile, cellular features and temperature ranges are indeed heterogeneous within Geodermatophilus. In contrast to previous studies, we also address which of these features can be interpreted as apomorphies of which taxon, according to the principles of phylogenetic systematics. We thus propose a novel genus, Klenkia, with the type species Klenkia marina sp. nov. and harbouring four species formerly assigned to Geodermatophilus, G. brasiliensis, G. soli, G. taihuensis and G. terrae. Emended descriptions of all species of Geodermatophilaceae are provided for which type-strain genome sequences are publicly available. Our study again demonstrates that the principles of phylogenetic systematics can and should guide the interpretation of both genomic and phenotypic data.

Before the establishment of pure cultures, the species Frankia alni , ‘ Frankia casuarinae ’ and ‘ Frankia elaeagni ’ were proposed to encompass all causal agents of the nitrogen-fixing root nodules of dicotyledonous plants from the genera Alnus, Casuarina or Elaeagnus. The sole Frankia species with a validly published name, the type species F. alni , was described by Woronin (1866) as present in the root of alder. Until now no type strain has been designated for F. alni , even though the absence of a type strain has seriously inhibited the application of modern taxonomic methods to the genus Frankia . Thus, we propose that strain ACN14aT, isolated in pure culture from Alnus viridis ssp. crispa with morphological properties matching the original description of F. alni , be recognized as the type strain of this species according to Rule 18f of the International Code of Nomenclature of Bacteria. We compared ACN14aT to two strains, CcI3T and BMG5.12T, isolated from Casuarina cunninghamiana and Elaeagnus angustifolia, respectively, based on chemotaxonomy, phenotype microarray data and molecular data retrieved from genome sequences. All three tested strains grew as branched hyphae, produced vesicles and multilocular sporangia containing non-motile spores and metabolized short fatty acids, TCA-cycle intermediates and carbohydrates. Chemotaxonomically, the three strains were indistinguishable with respect to phospholipids (phosphatidylinositol, diphosphatidylglycerol, glycophospholipids and phosphatidylglycerol) and cell-sugar composition (glucose, mannose, ribose, rhamnose, galactose and xylose, with the latter two being diagnostic for the genus). The major fatty acids identified in all three strains were iso-C16 : 0, C17 : 1 ω8c, C15 : 0, C17 : 0 and C16 : 0. ACN14aT and BMG5.12T also shared C15 : 1 ω6c, while C18 : 1 ω9c was found to be unique to BMG5.12T. The major menaquinones identified in all three novel type strains were MK-9(H8), MK-9(H6) and MK-9(H4). MK-9(H2) was shared by ACN14aT and BMG5.12T, while MK-10(H4) and MK-8(H4) were only found in BMG5.12T. Analysis of 16S rRNA gene sequences showed 98.1–98.9 % identity between strains ACN14aT, CcI3T and BMG5.12T. Digital DNA–DNA hybridization values between the three type strains were well below 70 %. These results confirm the separation of the strains into three distinct species, Frankia alni , Frankia casuarinae sp. nov. and Frankia elaeagni sp. nov. Thus, we propose ACN14aT (=DSM 45986T=CECT 9034T), CcI3T (=DSM 45818T=CECT 9043T) and BMG5.12T (=DSM 46783T=CECT 9031T) as the respective type strains.