Neumann-Schaal, Meina

A Gram-stain-positive, rod-shaped, aerobic, motile bacterium, J379T, was isolated from radioactive water spring C1, located in a former silver–uranium mine in the Czech Republic. This slow-growing strain exhibited optimal growth at 24–28 °C on solid media with <1 % salt concentration and alkaline pH 8–10. The only respiratory quinone found in strain J379T was MK-7(H4). C18 : 1 ω9c (60.9 %), C18 : 0 (9.4 %), C16 : 0 and alcohol-C18 : 0 (both 6.2 %) were found to be the major fatty acids. The peptidoglycan contained directly cross-linked meso-diaminopimelic acid. Phylogenetic reconstruction based on the 16S rRNA gene sequences and the core-genome analysis revealed that strain J379T forms a separate phylogenetic lineage within the recently amended order Solirubrobacterales. A comparison of the 16S rRNA gene sequences between strain J379T and other members of the order Solirubrobacterales showed <96 % similarity. This analysis revealed that the closest type strains were Parviterribacter kavangonensis D16/0 /H6T (95.2 %), Capillimicrobium parvum 0166_1T (94.9 %) and Conexibacter arvalis KV-962T (94.5 %). Whole-genome analysis showed that the closest type strain was Baekduia soli BR7-21T with an average nucleotide identity of 78 %, average amino acid identity of 63.2 % and percentage of conserved proteins of 48.2 %. The G+C content of the J379T genomic DNA was 71.7 mol%. Based on the phylogenetic and phylogenomic data, as well as its physiological characteristics, strain J379T is proposed to represent a type strain (DSM 113746T=CCM 9300T) of Svornostia abyssi gen. nov. sp. nov. within the family Baekduiaceae.

A novel sulphur-reducing bacterium was isolated from a pyrite-forming enrichment culture inoculated with sewage sludge from a wastewater treatment plant. Based on phylogenetic data, strain J.5.4.2-T.3.5.2T could be affiliated with the phylum Synergistota . Among type strains of species with validly published names, the highest 16S rRNA gene sequence identity value was found with Aminiphilus circumscriptus ILE-2T (89.2 %). Cells of the new isolate were Gram-negative, non-spore-forming, straight to slightly curved rods with tapered ends. Motility was conferred by lateral flagella. True branching of cells was frequently observed. The strain had a strictly anaerobic, asaccharolytic, fermentative metabolism with peptides and amino acids as preferred substrates. Sulphur was required as an external electron acceptor during fermentative growth and was reduced to sulphide, whereas it was dispensable during syntrophic growth with a Methanospirillum species. Major fermentation products were acetate and propionate. The cellular fatty acid composition was dominated by unsaturated and branched fatty acids, especially iso-C15 : 0. Its major polar lipids were phosphatidylglycerol, phosphatidylethanolamine and distinct unidentified polar lipids. Respiratory lipoquinones were not detected. Based on the obtained data we propose the novel species and genus Aminithiophilus ramosus, represented by the type strain J.5.4.2-T.3.5.2T (=DSM 107166T=NBRC 114655T) and the novel family Aminithiophilaceae fam. nov. to accommodate the genus Aminithiophilus. In addition, we suggest reclassifying certain members of the Synergistaceae into new families to comply with current standards for the classification of higher taxa. Based on phylogenomic data, the novel families Acetomicrobiaceae fam. nov., Aminiphilaceae fam. nov., Aminobacteriaceae fam. nov., Dethiosulfovibrionaceae fam. nov. and Thermovirgaceae fam. nov. are proposed.

AbstractAn actinobacterial strain A23T, isolated from adult ant Camponotus vagus collected in Ryazan region (Russia) and established as tetracenomycin X producer, was subjected to a polyphasic taxonomic study. Morphological characteristics of this strain included well-branched substrate mycelium and aerial hyphae fragmented into rod-shaped elements. Phylogenetic analyses based on 16S rRNA gene and genome sequences showed that strain A23T was most closely related to Amycolatopsis pretoriensis DSM 44654T. Average nucleotide identity and digital DNA–DNA hybridization values between the genome sequences of isolate A23T and its closest relative, Amycolatopsis pretoriensis DSM 44654T, were 39.5% and 88.6%, which were below the 70% and 95–96% cut-off point recommended for bacterial species demarcation, respectively. The genome size of the isolate A23T was 10,560,374 bp with a DNA G + C content of 71.2%. The whole-cell hydrolysate contained meso-diaminopimelic acid and arabinose and galactose as main diagnostic sugars as well as ribose and rhamnose. It contained MK-9(H4) as the predominant menaquinone and iso-C16:0, iso-C15:0, anteiso-C17:0 and C16:0 as the major cellular fatty acids. Diphosphatidylglycerol and phosphatidylethanolamine prevailed among phospholipids. Mycolic acids were not detected. Based on the phenotypic, genomic and phylogenetic data, isolate A23T represents a novel species of the genus Amycolatopsis, for which the name Amycolatopsis camponoti sp. nov. is proposed, and the type strain is A23T (= DSM 111725T = VKM Ac-2882T).