- Volume 67, Issue 5, 2017

An anaerobic bacterium, strain AT2T, was isolated from the fresh stool sample of a healthy French man using the culturomics approach. The 16S rRNA gene sequence analysis showed that strain AT2T had 95.2 % nucleotide sequence similarity with   Gemmiger formicilis  ATCC 27749T, the phylogenetically closest species with standing in nomenclature. Cells are Gram-stain-negative, catalase- and oxidase-negative, obligately anaerobic, non-motile, non-spore-forming, rod-shaped, and the bacilli were mesothermophilic. The major fatty acids were C16 : 0 (43.8 %) and C18 : 1n9 (20 %). The DNA G+C content of the strain based on its genome sequence was 56.8 mol%. Based on the phenotypic, biochemical and phylogenetic analysis, we propose the creation of the genus   Fournierella   gen. nov., which contains strain AT2T (=CSUR P2014T=DSM 100451T) as the type strain of the type species Fournierella massiliensis gen. nov., sp. nov.

A thermophilic, anaerobic, fermentative bacterium, strain A6T, was obtained from an anaerobic batch digester treating animal manure and rice straw. Cells were Gram-stain-positive, slightly curved rods with a size of 0.6–1×2.5–8.2 µm, non-motile and produced terminal spores. The temperature, pH and NaCl concentration ranges for growth were 40–60 °C, 6.5–8.0 and 0–15.0 g l−1, with optimum growth noted at 50–55 °C, pH 7.5 and in the absence of NaCl, respectively. Yeast extract was required for growth. d-Glucose, maltose, d-xylose, d-galactose, d-fructose, d-ribose, lactose, raffinose, sucrose, d-arabinose, cellobiose, d-mannose and yeast extract were used as carbon and energy sources. The fermentation products from glucose were ethanol, lactate, acetate, propionate, butyrate, valerate, iso-butyrate, iso-valerate, H2 and CO2. The G+C content of the genomic DNA was 36.6 mol%. The predominant fatty acids were C16 : 0, iso-C17 : 1, C14 : 0, C16 : 1 ω7c, C16 : 0 N-alcohol and C13 : 0 3-OH. Respiratory quinones were not detected. The polar lipid profile comprised phosphoglycolipids, phospholipids, glycolipids, a diphosphatidylglycerol, a phosphatidylglycerol and an unidentified lipid. Phylogenetic analyses of the 16S rRNA gene sequence indicated that the strain was closely related to Defluviitalea saccharophila DSM 22681T with a similarity of 96.0 %. Based on the morphological, physiological and taxonomic characterization, strain A6T is considered to represent a novel species of the genus Defluviitalea , for which the name Defluviitalea raffinosedens sp. nov. is proposed. The type strain is A6T (=DSM 28090T=ACCC 19951T).

A moderately thermophilic, anaerobic bacterium designated as strain KRT was isolated from a shallow-water submarine hydrothermal vent (Kunashir Island, Southern Kurils, Russia). Cells of strain KRT were thin (0.2–0.3 µm), flexible, motile, Gram-stain-negative rods of variable length. Optimal growth conditions were pH 6.6, 55 °C and 1–3 % (w/v) NaCl. Strain KRT was able to ferment a wide range of proteinaceous substrates, pyruvate, and mono-, di- and polysaccharides. The best growth occurred with proteinaceous compounds. Nitrate significantly stimulated the growth on proteinaceous substrates decreasing H2 formation, ammonium being the main product of nitrate reduction. Strain KRT did not need the presence of a reducing agent in the medium and tolerated the presence of oxygen in the gas phase up to 3 % (v/v). In the presence of nitrate, aerotolerance of isolate KRT was enhanced up to 6–8 % O2 (v/v). Strain KRT was able to grow chemolithoheterotrophically, oxidizing H2 and reducing nitrate to ammonium. Yeast extract (0.05 g l−1) was required for growth. The G+C content of the genomic DNA of strain KRT was 47.3 mol%. 16S rRNA gene sequence analysis placed isolate KRT in the phylum Calditrichaeota where it represented a novel species of a new genus, for which the name Calorithrix insularis gen. nov., sp. nov. is proposed. The type strain of Calorithrix insularis is KRT (=DSM 101605T=VKM B-3022T).

One strain of a novel genus and species of the order Planctomycetes , designated FC18T, was isolated from the epiphytic community of Fucusspiralis. This strain was non-pigmented in medium M13 but was slightly pink pigmented on medium M14, containing four-fold the levels of glucose, peptone and yeast extract of M13. The organism was primarily spherical, with unicellular non-motile forms and rosettes. The optimal temperature for growth was about 25 °C and the optimal pH was 7.5. FC18T was chemoorganotrophic and aerobic. Several sugars, polyols and amino acids were assimilated. The major fatty acids were C18 : 1ω9c, C14 : 0 and C16 : 0. The major polar lipids were phosphatidylglycerol (PG) and two unknown lipids. Menaquinone 5 (MK-5) was the main respiratory quinone, but MK-6 was also present. The results of the 16S rRNA gene sequence analysis confirmed the affiliation of this organism to the order Planctomycetales , family Planctomycetaceae , with Blastopirellula marina as the closest relative with only 86 % sequence similarity. On the basis of physiological, biochemical and chemotaxonomic characteristics we propose that FC18T(=LMG 29748T=DSM 26290T) represents a novel species of a novel genus of the family Planctomycetaceae for which we propose the name Mariniblastusfucicola gen. nov., sp. nov.

Arbuscular mycorrhizal fungi (AMF, subphylum Glomeromycotina) are symbionts of most terrestrial plants. They commonly harbour endobacteria of a largely unknown biology, referred to as MRE ( M ollicutes /mycoplasma-related endobacteria). Here, we propose to accommodate MRE in the novel genus ‘Candidatus Moeniiplasma.’ Phylogeny reconstructions based on the 16S rRNA gene sequences cluster ‘Ca. Moeniiplasma ’ with representatives of the class Mollicutes , whereas phylogenies derived from amino acid sequences of 19 genes indicate that it is a discrete lineage sharing ancestry with the members of the family Mycoplasmataceae . Cells of ‘Ca. Moeniiplasma ’ reside directly in the host cytoplasm and have not yet been cultivated. They are coccoid, ~500 nm in diameter, with an electron-dense layer outside the plasma membrane. However, the draft genomes of ‘Ca. Moeniiplasma ’ suggest that this structure is not a Gram-positive cell wall. The evolution of ‘Ca. Moeniiplasma ’ appears to be driven by an ultrarapid rate of mutation accumulation related to the loss of DNA repair mechanisms. Moreover, molecular evolution patterns suggest that, in addition to vertical transmission, ‘Ca. Moeniiplasma ’ is able to transmit horizontally among distinct Glomeromycotina host lineages and exchange genes. On the basis of these unique lifestyle features, the new species ‘Candidatus Moeniiplasma glomeromycotorum’ is proposed.

The anaerobic, non-motile strain HMT was isolated from the naphthalene-degrading, sulfate-reducing enrichment culture N47. For 20 years, strain HMT has been a stable member of culture N47 although it is neither able to degrade naphthalene nor able to reduce sulfate in pure culture. The highest similarity of the 16S rRNA gene sequence of strain HMT (89 %) is with a cultivated member of the family Spirochaetaceae , Treponema caldarium strain H1T (=DSM 7334T), an obligately anaerobic, thermophilic spirochaete isolated from cyanobacterial mat samples collected at a freshwater hot spring in Oregon, USA. In contrast to this strain and the majority of spirochaete species described, strain HMT showed a rod-shaped morphology. Growth occurred at temperatures between 12 and 50 °C (optimum 37 °C) but the isolate was not able to grow at 60 °C. The strain fermented various sugars including d-glucose, d-fructose, lactose and sucrose. Addition of 0.1 % (w/v) yeast extract or 0.1 % (w/v) tryptone to the culture medium was essential for growth and could not be replaced by either the vitamin solutions tested or by 0.1 % (w/v) peptone or 0.1 % (w/v) casamino acids. The DNA G+C content of the isolate was 51.5 mol%. The major fatty acids were C14 : 0, C18 : 1ω13c, C16 : 1ω9t, C16 : 1ω11c and C16 : 1ω9c. Based on the unique morphology and the phylogenetic distance from the closest cultivated relative, a novel genus and species, Rectinema cohabitans gen. nov., sp. nov., is proposed. The type strain is strain HMT (=DSM 100378T=JCM 30982T).

A filamentous, soil-dwelling cyanobacterial strain (9C-PST) was isolated from Mandsaur, Madhya Pradesh, India, and is described as a new species of the genus Nostoc . Extensive morphological and molecular characterization along with a thorough assessment of ecology was performed. The style of filament orientation, type and nature of the sheath (e.g. distribution and visibility across the trichome), and vegetative and heterocyte cell dimensions and shape were assessed for over one year using both the laboratory grown culture and the naturally occurring samples. Sequencing of the 16S rRNA gene showed 94 % similarity with Nostoc piscinale CENA21 while analyses of the secondary structures of the 16S–23S ITS region showed unique folding patterns that differentiated this strain from other species of Nostoc . The level of rbcl and rpoC1 gene sequence similarity was 91 and 94 % to Nostoc sp. PCC 7524 and Nostoc piscinale CENA21, respectively, while the nifD gene sequence similarity was found to be 99 % with Nostoc piscinale CENA21. The phenotypic, ecological, genetic and phylogenetic observations indicate that the strain 9C-PST represents a novel species of the genus Nostoc with the name proposed being Nostoc thermotolerans sp. nov. according to the International Code of Nomenclature for Algae, Fungi, and Plants.

A novel bacterium, strain Ru1T, was encountered during a survey of spirochaetes living in the gastrointestinal tract of ruminants. Comparative analysis of 16S rRNA gene sequence data indicated that strain Ru1T clustered within the genus Treponema but shared at most 86.1 % sequence similarity with other recognised species of the genus Treponema . Further phylogenetic analysis based on partial recombinase A (recA) gene sequence comparisons, together with phenotypic characterization, also demonstrated the divergence of strain Ru1T from other recognised species of the genus Treponema . Microscopically, strain Ru1T appeared as a very small, highly motile, helical spirochaete with eight periplasmic flagella in a 4 : 8 : 4 arrangement. It exhibited C8 esterase lipase, leucine arylamidase, β-galactosidase and β-glucosidase activity. A distinctive, serum-independent growth pattern was also observed, characterized by colonies with an absence of the local haemolysis that is typical of many pathogenic treponemes. On the basis of these data, strain Ru1T is considered to represent a novel species of the genus Treponema , for which the name Treponema ruminis sp. nov. is proposed. The type strain is Ru1T (=DSM 103462T=NCTC 13847T).

A strictly anaerobic, Gram-stain-negative, non-spore-forming bacterium designated NSZ-14T, isolated from contaminated groundwater in Louisiana (USA), was characterized using a polyphasic approach. Strain NSZ-14T reductively dehalogenated a variety of polychlorinated aliphatic alkanes, producing ethene from 1,2-dichloroethane, propene from 1,2-dichloropropane, a mixture of cis- and trans-1,2-dichloroethene from 1,1,2,2-tetrachloroethane, vinyl chloride from 1,1,2-trichloroethane and allyl chloride (3-chloro-1-propene) from 1,2,3-trichloropropane. Formate or hydrogen could both serve as electron donors. Dechlorination occurred between pH 5.5 and 7.5 and over a temperature range of 20–37 °C. Major cellular fatty acids included C18 : 1ω9c, C14 : 0 and C16 : 0. 16S rRNA gene sequence-based phylogenetic analysis indicated that the strain clusters within the class Dehalococcoidia of the phylum Chloroflexi , most closely related to but distinct from type strains of the species Dehalogenimonas alkenigignens (97.63 % similarity) and Dehalogenimonas lykanthroporepellens (95.05 %). A complete genome sequence determined for strain NSZ-14T revealed a DNA G+C content of 53.96 mol%, which was corroborated by HPLC (54.1±0.2 mol% G+C). Genome-wide comparisons based on average nucleotide identity by orthology and estimated DNA–DNA hybridization values combined with phenotypic and chemotaxonomic traits and phylogenetic analysis indicate that strain NSZ-14T represents a novel species within the genus Dehalogenimonas , for which the name Dehalogenimonas formicexedens sp. nov. is proposed. The type strain is NSZ-14T (=HAMBI 3672T=JCM 19277T=VKM B-3058T). An emended description of Dehalogenimonas alkenigignens is also provided.

A novel, thermophilic filamentous anoxygenic phototrophic bacterium, strain isl-2T, was isolated from the Strokkur Geyser, Iceland. Strain isl-2T formed unbranched multicellular filaments with gliding motility. The cells formed no spores and stained Gram-negative. The existence of pili was described in a species of the genus Chloroflexus for the first time, to our knowledge. Optimal growth occurred at a pH range of 7.5–7.7 and at a temperature of 55 °C. Strain isl-2T grew photoheterotrophically under anaerobic conditions in the light and chemoheterotrophically under aerobic conditions in the dark. The major cellular fatty acids were C18 : 1ω9, C16 : 0, C18 : 0 and C18 : 0-OH. The major quinone was menaquinone-10. The photosynthetic pigments were bacteriochlorophylls c and a as well as β- and γ-carotenes. The results of phylogenetic analysis of the 16S rRNA gene sequences placed strain isl-2T into the genus Chloroflexus of the phylum Chloroflexi with Chloroflexus aggregans DSM 9485T as the closest relative (97.0 % identity). The whole-genome sequence of isl-2T was determined. Average nucleotide identity values obtained for isl-2T in comparison to available genomic sequences of other strains of members of the genus Chloroflexus were 81.4 % or less and digital DNA–DNA hybridisation values 22.8 % or less. The results of additional phylogenetic analysis of the PufLM and BchG amino acid sequences supported the separate position of the isl-2T phylotype from the phylotypes of other members of the genus Chloroflexus . On the basis of physiological and phylogenetic data as well as genomic data, it was suggested that isl-2T represents a novel species within the genus Chloroflexus , with the proposed name Chloroflexus islandicus sp. nov. The type strain of the species is isl-2T (=VKM B-2978T,=DSM 29225T,=JCM 30533T).

Albeit being widespread and abundant in soils worldwide, bacteria of the phylum Acidobacteria have remained grossly understudied due to difficulties in their cultivation and isolation. To date, only 48 species have been validly described, including a single member of the phylogenetically diverse Acidobacteria subdivision 6. Here, we report the polyphasic characterization of strain HEG_−6_39T, a novel representative of Acidobacteria subdivision 6 isolated from a grassland soil in Thuringia, Germany. Cells of HEG_−6_39T are Gram-stain-negative, non-motile, non-spore-forming, non-capsulated short rods that form small dark yellow colonies. This slow growing bacterium is psychrotolerant and grows between 0 and 36 °C. It displays a narrower pH tolerance (5.3–8.3) than most acidobacteria. The strain is an aerobe that grows chemo-organotrophically utilizing mostly sugars and proteinaceous substrates such as peptone, yeast extract, casein hydrolysate and casamino acids as substrates. Diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, phosphatidylglycerol and two unknown phospholipids are identified as polar lipids. Major fatty acids are iso-C15 : 0, summed feature 3 (C16 : 1ω6c/C16  : 1ω7c), C18 : 1ω9c and iso-C17 : 1ω9c. The major respiratory quinone is MK-8. The G+C content of the genomic DNA is 64.7 mol%. 16S rRNA gene sequence analysis indicated that this bacterium was related to Vicinamibacter silvestris Ac_5_C6T with 93.6 % sequence similarity. Based on the present taxonomic characterization, strain HEG_-6_39T represents a new species of a novel genus for which the name Luteitalea pratensis gen. nov., sp. nov., is proposed. The type strain of the type species is HEG_−6_39T (=DSM 100886T=KCTC 52215T).

The taxonomic position of two isolates belonging to the genus Sphingobacterium was determined. The first isolate, R-53603T, was obtained from purulent discharge from the toe of a cellulitis patient in Kuwait. Comparative 16S rRNA gene sequence analysis revealed 99.87 % similarity of R-53603T with environmental isolate P031 (=R-53745) originating from activated sludge in Singapore. The two isolates were phylogenetically positioned on the same sub-branch. Highest 16S rRNA gene sequence similarity was found with the type strains of Sphingobacterium mizutaii (98.23 %), Sphingobacterium lactis (97.78 %) and Sphingobacterium daejeonense (97.14 %). DNA–DNA hybridizations revealed <70 % relatedness between the two isolates and the type strains of the close phylogenetic neighbours S. mizutaii (18.0–24.5 %), S. lactis (20.3–25.9 %) and S. daejeonense (13.2–20.0 %). The high relative contribution of iso-C15 : 0, iso-C17 : 0 3-OH and summed feature 3 (iso-C15 : 0 2-OH and/or C16 : 1ω7c) in the cellular fatty acid profiles of R-53603T and R-53745, the presence of sphingophospholipids, MK-7 as the dominant menaquinone and phosphatidylethanolamine as the major polar lipid in strain R-53603T are typical chemotaxonomic characteristics for members of the genus Sphingobacterium . Phenotypic features most useful for differentiation of the two novel strains from the most closely related species S. mizutaii include growth on MacConkey agar, and utilization of stachyose, guanidine HCl and lithium chloride in Biolog GEN III tests. Strains R-53603T and R-53745 thus represent a novel species, for which the name Sphingobacterium cellulitidis sp. nov. is proposed. The type strain is R-53603T (=LMG 28764T=DSM 102028T).

A bacterial strain, designated T20R-70T, was isolated from tomato rhizosphere soil collected in Yecheon-gun, Gyeongsangbuk-do in South Korea. Growth was observed within the ranges 10–40 °C (optimally at 28–30 °C), pH 7.0–8.0 (optimally at pH 7.0) and 0–1 % NaCl (optimally at 0 %). The 16S rRNA gene sequence showed the highest similarities with those of Lysobacter hankyongensis KTCe-2T (98.7 %), Lysobacter brunescens KCTC 12130T (98.0 %), ‘ Lysobacter daecheongensis ' Dae08 (97.2 %) and Lysobacter oligotrophicus 107-E2T (97.1 %). The phylogenetic tree showed that strain T20R-70T formed a clade with Lysobacter hankyongensis KTCe-2T and Lysobacter brunescens KCTC 12130T. The dominant fatty acids (>10 %) were iso-C15 : 0, iso-C16 : 0, iso-C17 : 1ω9c and summed feature 3 (including iso-C15 : 0 2-OH and/or iso-C16 : 1ω7c). The major polar lipids were phosphatidylethanolamine, diphosphatidylglycerol and phosphatidylglycerol. The major respiratory quinone was Q-8. DNA–DNA hybridization data revealed that strain T20R-70T had a hybridization value of 42±4 % (mean±sd) to the most closely related species of the genus Lysobacter . The DNA G+C content was 63.0 mol%. The physiological, biochemical and chemotaxonomic data allowed the discrimination of the new isolate from its phylogenetic relatives. Strain T20R-70T is thus considered to be a representative of a novel species of the genus Lysobacter , for which the name Lysobacter solanacearum sp. nov. is proposed. The type strain is T20R-70T (=KACC 18656T=NBRC 111881T).

A novel non-phototrophic, marine, sulfur-oxidizing bacterium, strain S-1T, was isolated from a coastal salt marsh in Massachusetts, USA. Cells are Gram-stain-negative vibrios motile by means of a single polar unsheathed flagellum. S-1T is an obligate microaerophile with limited metabolic capacity. It grows chemolithoautotrophically utilizing sulfide and thiosulfate as electron donors, converting these compounds to sulfate, and the Calvin–Benson–Bassham cycle for carbon fixation. Cells of S-1T did not grow on any of a large number of organic carbon sources and there was no evidence for chemoorganoheterotrophic growth. Cells produced internal sulfur globules during growth on sulfide and thiosulfate. S-1T is strongly diazotrophic, as demonstrated by 15N2 fixation and acetylene reduction activity by cells when a fixed nitrogen source is absent from the growth medium. The marine nature of this organism is evident from its ability to grow in 10 to 100 % artificial seawater but not at lower concentrations and NaCl alone cannot substitute for sea salts. The major cellular fatty acids are C16 : 1ω7c, C16 : 0, and C18 : 1ω7c. Phosphatidylethanolamine and phosphatidylglycerol are the major polar lipids. Q8 is the only respiratory quinone. S-1T genomic DNA has a G+C content of 67.6 mol%. Based on its 16S rRNA gene sequence, S-1T shows the closest phylogenetic relationship to non-phototrophic species within the family Thioalkalispiraceae of the class Gammaproteobacteria . The name Endothiovibrio diazotrophicus is proposed for this organism, with S-1T as the type strain (ATCC BAA-1439T=JCM 17961T).

A straw-coloured, Gram-staining-negative, aerobic, motile and rod-shaped bacterium, designated strain K-1-15T, was isolated from reclaimed grassland soil from Biratnagar, Morang, Nepal. This strain was non-spore-forming, catalase-negative and oxidase-positive. It was able to grow at 10–45 °C, pH 6.5–9.5 and 0–1.5 % (w/v) NaCl concentration. This strain was taxonomically characterized by a polyphasic approach. Based on the results of 16S rRNA gene sequence analysis, K-1-15T formed a distinct lineage within the family Oxalobacteraceae and was most closely related to members of the genera Herbaspirillum (96.99–95.34 % sequence similarity), Noviherbaspirillum (96.72–95.45 % sequence similarity) and Paraherbaspirillum (95.85 % sequence similarity). The only respiratory quinone was ubiquinone-8. The polar lipid profile revealed the presence of phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylcholine. The major fatty acids of K-1-15T were summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), C16  :   0, summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c), C10 : 0 3-OH, and iso-C16 : 0. The genomic DNA G+C content of this novel strain was 65.2 mol %. The DNA–DNA relatedness between K-1-15T and Herbaspirillum massiliense DSM 25712T and Noviherbaspirillum soli LMG 26149T were 18.3 and 13.7 % repectively. On the basis of the results of morphological, physiological, chemotaxonomic and phylogenetic analyses, K-1-15T represents a novel species of the genus Noviherbaspirillum in the family Oxalobacteraceae , for which the name Noviherbaspirillum agri sp. nov. is proposed. The type strain is K-1-15T (=KEMB 9005-422T=KACC 18909T=JCM 31463T). Based on new data obtained in this study, we also propose the reclassification of Herbaspirillum massiliense as Noviherbaspirillum massiliense comb. nov. (type strain JC206T=CSUR P159T=DSM 25712T).

Previously we proposed the reclassification of a thermotolerant phototrophic bacterium, ‘ Rhodopseudomonas cryptolactis’ Stadtwald-Demchick et al. 1990, as ‘ Rhodoplanes cryptolactis’ nom. rev., comb. nov. with strain DSM 9987T (ATCC 49414T) as the type strain. However, while both the names ‘ Rhodopseudomonas cryptolactis’ and ‘ Rhodoplanes cryptolactis’ have not been validated, strain ATCC 49414T is no longer available from the culture collection. This situation indicates that the taxonomic status of the bacterium with both the names to be validated has been lost. In this study, we re-examined the taxonomic characteristics of strain DSM 9987T (TUT3520T as our own collection number) compared with those of six species of the genus Rhodoplanes with validly published names. The results of 16S rRNA gene sequence comparisons indicated that TUT3520T had a 99.0 % level of similarity to the type strains of Rhodoplanes oryzae and Rhodoplanes elegans as its closest relatives and 98.9–96.2 % similarities to other species of the genus Rhodoplanes . Genomic DNA–DNA similarities between TUT3520T and the type strains of the species of the genus Rhodoplanes were less than 50 %. Results of phenotypic testing indicated that TUT3520T could be differentiated from any species of the genus Rhodoplanes by a combination of in vivo absorption spectra, growth temperature, vitamin requirements, carbon nutrition and some other characteristics. Thus, we propose Rhodoplanes tepidamans sp. nov. to accommodate the bacterium previously referred to as ‘ Rhodoplanes ( Rhodopseudomonas ) cryptolactis’. The type strain is strain TUT3520T (=DSM 9987T=NBRC 104267T).

A Gram-stain-negative, alkaliphilic and moderately halophilic bacterium, designated 56-L4-10aEnT, was isolated from a household product plant in China. Cells of the novel isolate were rod-shaped, non-spore-forming and non-motile. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain 56-L4-10aEnT belongs to the genus Halomonas , with the six closest neighbours being Halomonas mongoliensis Z-7009T (97.59 % 16S rRNA gene sequence similarity), Halomonas ventosae Al12T (97.35 %), Halomonas campaniensis 5AGT (97.22 %), Halomonas alimentaria YKJ-16T (97.22 %), Halomonas shengliensis SL014B-85T (97.12 %) and Halomonas fontilapidosi 5CRT (97.09 %). The main polar lipids of strain 56-L4-10aEnT contained diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The predominant respiratory quinone was Q-9, with Q-8 as a minor component. The major fatty acids were C18 : 1ω7c/C18  : 1ω6c and C16 : 0. Strain 56-L4-10aEnT was clearly distinguished from the type strains mentioned above through phylogenetic analysis, DNA–DNA hybridization, fatty acid composition data and a range of physiological and biochemical characteristics comparisons. It is evident from the genotypic and phenotypic data that strain 56-L4-10aEnTcould be classified as a representative of a novel species of the genus Halomonas , for which the name Halomonas alkalicola sp. nov. is proposed. The type strain is 56-L4-10aEnT (=CICC 11012sT=DSM 103354T).

A Gram-staining-negative, aerobic, non-motile, capsule-forming and rod-shaped bacterium, designated JH-7T, was isolated from sludge of a manganese mine. The 16S rRNA gene sequence of JH-7T showed highest similarities to those of Pseudaminobacter salicylatoxidans BN12T (97.4 %), Mesorhizobiumthiogangeticum SJTT (97.0 %) and Pseudaminobacter defluvii THI 051T (96.5 %). Phylogenetic trees clustered JH-7T together with P. salicylatoxidans BN12T and P. defluvii THI 051T. The DNA–DNA hybridization values between JH-7T and P. salicylatoxidans DSM 6986T and between JH-7T and M . thiogangeticum DSM 17097T were 34.8 and 20.1 %, respectively. The major fatty acids of JH-7T (>10 %) were C18 : 1ω7c, C19 : 0cyclo ω8c and C16 : 0. The genomic DNA G+C content was 61.6 mol%. The polyamines of JH-7T were sym-homospermidine (83 %) and putrescine (17 %), and the respiratory quinone was ubiquinone-10. The major polar lipids were phosphatidylmonomethylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, two unidentified aminolipids and two unidentified lipids. Compared with the members of the genera Pseudaminobacter and Mesorhizobium , JH-7T showed some unique physiological and biochemical characters, such as being negative for H2S production, hydrolysis of Tween 40 and Tween 60, esterase lipase (C8) activity and assimilation of d-ribose and positive for acid production from d-galactose and assimilation of d-fructose. On the basis of the results of the polyphasic taxonomic analysis, JH-7T was considered to represent a novel species of the genus Pseudaminobacter , for which the name Pseudaminobacter manganicus sp. nov. is proposed. The type strain is JH-7T (=KCTC 52258T=CCTCC AB 2016107T).

Two slightly yellowish-pigmented, oxidase-negative, rod-shaped and Gram-stain-negative bacterial strains (30TX1T and DL20T), isolated from Steinernema sangi and Steinernema eapokense, respectively, during soil sampling in Vietnam were studied using a polyphasic taxonomic approach. Strain 30TX1T showed highest 16S rRNA gene sequence similarity to the type strain of Xenorhabdus ehlersii (98.9 %) and strain DL20T to that of Xenorhabdus ishibashii (98.7 %). Sequence similarities to all other Xenorhabdus species were lower (<98.4 %). The two strains shared 98 % 16S rRNA gene sequence similarity. Multilocus sequence analysis (MLSA) based on concatenated partial recA, dnaN, gltX, gyrB and infB gene sequences showed a clear distinction of strains 30TX1T and DL20T among each other and to the closest related type strains. DNA–DNA hybridizations between strain DL20T and the type strain of X. ishibashii resulted in a relatedness value of 53 %. Genome-to-genome-based comparisons gave average nucleotide identities of 93.6 % (reciprocal 93.5 %) for strain 30TX1T and X. ehlersii DSM 16337T, of 92.8 % (reciprocal 93 %) for strain DL20T and X. ishibashii DSM 22670Tand of 93.0 % (reciprocal 93.2 %) for the two novel strains. The fatty acid profile of the strains consisted of the major fatty acids C14 : 0, C16 : 0, C17 : 0 cyclo, C16 : 1ω7c and/or iso-C15 : 0 2-OH, and C18 : 1 ω7c. Genome-to-genome comparison and MLSA results together with the differential biochemical and chemotaxonomic properties showed that strains 30TX1T and DL20T represent novel Xenorhabdus species, for which the names Xenorhabdus thuongxuanensis sp. nov. (type strain 30TX1T=CCM 8727T=LMG 29916T) and Xenorhabdus eapokensis sp. nov. (type strain DL20T=CCM 8728T=LMG 29917T) are proposed, respectively.