A novel alkalitolerant, sulphate-reducing bacterium (strain RT2 T ) was isolated from alkaline district heating water. Strain RT2 T was a motile vibrio (0?5-0?8 mm wide and 1?4-1?9 mm long) and grew at pH 6?9-9?9 (optimum at pH 9?0-9?4) and at 16-47 6C (optimum at 43 6C). The genomic DNA G+C content was 64?7 mol%. A limited number of compounds were used as electron donors with sulphate as electron acceptor, including lactate, pyruvate, formate and hydrogen/acetate. Sulphite and thiosulphate also served as electron acceptors. Based on physiological and genotypic properties, the isolate was considered to represent a novel species of the genus Desulfovibrio, for which the name Desulfovibrio alkalitolerans sp. nov. is proposed. The type strain is RT2 T

Twenty-nine strains of Aggregatibacter actinomycetemcomitans cultured from blood stream infections in Denmark were characterised. Serotyping was unremarkable, with almost equal proportions of the three major types plus a single serotype e strain. Whole genome sequencing positioned the serotype e strain outside the species boundary; moreover, one of the serotype a strains was unrelated to other strains of the major serotypes and to deposited sequences in the public databases. We identified five additional strains of this type in our collections. The particularity of the group was corroborated by phylogenetic analysis of concatenated core genes present in all strains of the species, and by uneven distribution of accessory genes only present in a subset of strains. Currently, the most accurate depiction of A. actinomycetemcomitans is a division into three lineages that differ in genomic content and competence for transformation. The clinical relevance of the different lineages is not known, and even strains excluded from the species sensu stricto can cause serious human infections. Serotyping is insufficient for characterisation, and serotypes a and e are not confined to specific lineages.

A novel alkalitolerant, anaerobic bacterium, designated strain sk.kt5T, was isolated from a metal coupon retrieved from a corrosion-monitoring reactor of a Danish district heating plant (Skanderborg, Jutland). The cells of strain sk.kt5T were motile, rod-shaped (0.4–0.6×2.5–9.6 μm), stained Gram-positive and formed endospores. Strain sk.kt5T grew at pH 7.6–10.5 (with optimum growth at pH 8.0–9.5), at temperatures in the range 23–44 °C (with optimum growth at 35–37 °C), at NaCl concentrations in the range 0–5 % (w/v) (with optimum growth at 0–0.5 %) and required yeast extract for growth. Only a limited number of substrates were utilized as electron donors, including betaine, formate, lactate, methanol, choline and pyruvate. Elemental sulfur, sulfite, thiosulfate, nitrate and nitrite, but not sulfate or Fe(III) citrate, were used as electron acceptors. The G+C content of the DNA was 41.6 mol%. Phylogenetic analyses of the sequence data for the dsrAB genes [encoding the major subunits of dissimilatory (bi)sulfite reductase] and the 16S rRNA gene placed strain sk.kt5T within a novel lineage in the class Clostridia of the phylum Firmicutes. Taken together, the physiological and genotypic data suggest that strain sk.kt5T represents a novel species within a novel genus, for which the name Desulfitibacter alkalitolerans gen. nov., sp. nov. is proposed. The type strain of Desulfitibacter alkalitolerans is sk.kt5T (=JCM 12761T=DSM 16504T).

A novel actinobacterium, designated PNP1(T), was isolated from a wastewater treatment plant at a pesticide factory by selective enrichment with para-nitrophenol. The strictly aerobic strain PNP1(T) grew with para-nitrophenol as the sole carbon and energy source. Metabolism of para-nitrophenol resulted in the stoichiometric release of nitrite. When incubated with both para-nitrophenol and acetate, para-nitrophenol was degraded and utilized as growth substrate prior to acetate. When grown on acetate (in the absence of ammonium) both nitrite and nitrate served as nitrogen sources, nitrate being quantitatively reduced to nitrite which accumulated in cultures during aerobic growth. Cells were coccoid and stained Gram-positive, were non-motile and did not form endospores. Colonies of strain PNP1(T) on agar medium were bright yellow, circular and smooth. The dominant menaquinone was MK-8(H(2)) (54%) and the major cellular fatty acid was anteiso C15:0 (75%). Strain PNP1(T) grew optimally at 27°C, at pH 8-8.5, at salinities 3% (w/v) NaCl, yet exhibited a substantial halotolerance with growth occurring at salinities up to 17% (w/v) NaCl. In addition to para-nitrophenol, a range of sugars, short chain fatty acids and alcohols served as electron donors for growth. The DNA G + C mol% was 68%. The genotypic and phenotypic properties suggest that strain PNP1(T) represents a novel species of the actinobacterial genus Citricoccus for which the name Citricoccus nitrophenolicus is proposed. It is the first member of this genus that has been reported to hydrolyze and grow on para-nitrophenol. The type strain is PNP1(T) (=DSM 23311(T) = CCUG 59571(T)).