- Volume 59, Issue 6, 2009

Strain XM-003T was isolated from a soil sample that originated from the Ximo region in Tibet. Cells of strain XM-003T were Gram-negative-staining, non-motile, irregular-shaped rods and the strain grew optimally at 28 °C and grew at pH 5–8. It contained MK-7 as the major isoprenoid quinone and iso-C15 : 0 and C16 : 1 ω7c and/or iso-C15 : 0 2-OH as the major fatty acids. Flexirubin-type pigments were absent. The DNA G+C content was 43.4 mol%. The 16S rRNA gene sequence of this strain showed the highest sequence similarity of 96.0 % to Mucilaginibacter kameinonensis SCKT. A number of physiological biochemical tests and chemotaxonomic markers indicate that strain XM-003T represents a novel species of the genus Mucilaginibacter, for which the name Mucilaginibacter ximonensis sp. nov. is proposed. The type strain is XM-003T (=CCTCC AB 207094T =KCTC 22437T).

A Gram-negative-staining, non-spore-forming bacterium devoid of flagella, designated strain B9T, was isolated from rice paddy soil associated with the roots of Oryza sativa collected from Jinju, South Korea. Cells were straight rods, were catalase- and oxidase-positive and were able to hydrolyse pectin, xylan and laminarin. Growth of strain B9T was observed between 15 and 35 °C (optimum 25–30 °C) and between pH 5.0 and 8.0 (optimum pH 6.5–7.5). Strain B9T contained menaquinone-7 (MK-7) as a major isoprenoid quinone and summed feature 3 (C16 : 1 ω7c and/or iso-C15 : 0 2-OH), iso-C15 : 0 and C16 : 0 as major fatty acids. The G+C content of the genomic DNA was 44.4 mol%. Comparative 16S rRNA gene sequence analysis showed that strain B9T belonged to the genus Mucilaginibacter, a member of the family Sphingobacteriaceae, and was most closely related to Mucilaginibacter kameinonensis SCKT (95.9 % sequence similarity). On the basis of chemotaxonomic data and molecular properties, strain B9T represents a novel species of the genus Mucilaginibacter, for which the name Mucilaginibacter oryzae sp. nov. is proposed. The type strain is B9T (=KACC 12816T =DSM 19975T).

A psychrophilic, Gram-negative, dark orange-pigmented bacterium, designated CL-AP4T, was isolated from a culture of the green alga Pyramimonas gelidicola obtained from the Southern Ocean. Strain CL-AP4T grew optimally at 10 °C, in the presence of 3–4 % sea salts and at pH 8. 16S rRNA gene sequence analysis revealed that strain CL-AP4T belonged to the family Flavobacteriaceae, with Maribacter arcticus KOPRI 20941T as its closest relative (97.2 % similarity). A number of chemotaxonomic characteristics supported affiliation of strain CL-AP4T with the genus Maribacter, i.e. iso-C15 : 0 (17.2 %), iso-C15 : 1 (16.8 %) and iso-C17 : 0 3-OH (14.9 %) were the dominant fatty acids, MK-6 was the major menaquinone and the DNA G+C content was 37.1 mol%. DNA–DNA relatedness between CL-AP4T and M. arcticus KOPRI 20941T was only 10 %, suggesting that they are genomically distinct species. In addition, strain CL-AP4T differed phenotypically from M. arcticus in its optimum growth temperature, its ability to hydrolyse starch, Tween 40 and Tween 80, and production of certain enzymes. On the basis of the results of the polyphasic analysis, strain CL-AP4T was classified in the genus Maribacter as belonging to a novel species, for which the name Maribacter antarcticus sp. nov. is proposed; the type strain is CL-AP4T (=KCCM 90069T=JCM 15445T).

The taxonomic position of a novel marine, yellow-pigmented bacterium, designated strain KMM 6211T, was examined by using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain KMM 6211T is a member of the family Flavobacteriaceae, phylum Bacteroidetes. The closest relative of strain KMM 6211T was Winogradskyella eximia KMM 3944T, the sequence similarity being 97.1 %. The DNA G+C content of KMM 6211T was 33.6 mol%. The strain was motile by gliding and grew with 1–6 % NaCl and at 4–37 °C. Aesculin, casein and gelatin were hydrolysed, but agar, starch, DNA and chitin were not degraded. On the basis of phylogenetic data and phenotypic differences between the isolate and recognized Winogradskyella species, strain KMM 6211T represents a novel species of the genus Winogradskyella, for which the name Winogradskyella echinorum sp. nov. is proposed. The type strain is KMM 6211T (=KCTC 22026T=LMG 24757T).

During a search for exo-enzyme-producing bacteria in the gut of an insect, Diestrammena apicalis, a novel bacterium capable of degrading pectin was isolated. The isolate, designated strain RCB-08T, comprised Gram-positive, endospore-forming, motile rods capable of growth at 15–30 °C and pH 6.0–8.7. The DNA G+C content of the isolate was 51.5 mol% and the predominant cellular fatty acid was anteiso-C15 : 0 (74.1 %). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain RCB-08T was affiliated with a cluster within the Paenibacillaceae, and was related most closely to Paenibacillus chondroitinus NBRC 15376T, with a sequence similarity of 96.7 %. The DNA–DNA relatedness value for strain RCB-08T with P. chondroitinus NBRC 15376T was 15.0 %. Strain RCB-08T hydrolysed pectin, but not cellulose, casein, starch or xylan. Strain RCB-08T could be clearly distinguished from other Paenibacillus species on the basis of characteristics observed using a polyphasic approach. Therefore strain RCB-08T is considered to represent a novel species of the genus Paenibacillus, for which the name Paenibacillus pectinilyticus sp. nov. is proposed. The type strain is RCB-08T (=KCTC 13222T=CECT 7358T).

The Mycoplasma mycoides cluster consists of six pathogenic mycoplasmas causing disease in ruminants, which share many genotypic and phenotypic traits. The M. mycoides cluster comprises five recognized taxa: Mycoplasma mycoides subsp. mycoides Small Colony (MmmSC), M. mycoides subsp. mycoides Large Colony (MmmLC), M. mycoides subsp. capri (Mmc), Mycoplasma capricolum subsp. capricolum (Mcc) and M. capricolum subsp. capripneumoniae (Mccp). The group of strains known as Mycoplasma sp. bovine group 7 of Leach (MBG7) has remained unassigned, due to conflicting data obtained by different classification methods. In the present paper, all available data, including recent phylogenetic analyses, have been reviewed, resulting in a proposal for an emended taxonomy of this cluster: (i) the MBG7 strains, although related phylogenetically to M. capricolum, hold sufficient characteristic traits to be assigned as a separate species, i.e. Mycoplasma leachii sp. nov. (type strain, PG50T = N29T = NCTC 10133T = DSM 21131T); (ii) MmmLC and Mmc, which can only be distinguished by serological methods and are related more distantly to MmmSC, should be combined into a single subspecies, i.e. Mycoplasma mycoides subsp. capri, leaving M. mycoides subsp. mycoides (MmmSC) as the exclusive designation for the agent of contagious bovine pleuropneumonia. A taxonomic description of M. leachii sp. nov. and emended descriptions of M. mycoides subsp. mycoides and M. mycoides subsp. capri are presented. As a result of these emendments, the M. mycoides cluster will hereafter be composed of five taxa comprising three subclusters, which correspond to the M. mycoides subspecies, the M. capricolum subspecies and the novel species M. leachii.

In the course of a study of the prokaryotic diversity of a landfill site in Chandigarh, India, a strain designated SK 55T was isolated and characterized using a polyphasic approach. Its 16S rRNA gene sequence showed closest similarity (98.3 %) to that of Sporosarcina macmurdoensis CMS 21wT. The sequence similarity to strains of other hitherto described species of Sporosarcina was less than 95.5 %. Strain SK 55T contains peptidoglycan of the A4α type (l-Lys–d-Asp), MK-8 and MK-7 as the major menaquinones and iso-C15 : 0 as the major fatty acid. Strain SK 55T, Sporosarcina macmurdoensis and Sporosarcina ureae, the type species of the genus, had some polar lipids in common (diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, a phospholipid and an unknown lipid). However, an aminolipid, an aminophospholipid and an unknown lipid found in the former two organisms are similar, though not identical, but quite different from the profile of S. ureae. The genomic DNA G+C contents of strain SK 55T (46.0 mol%) and S. macmurdoensis CMS 21wT (44.0 mol%) are higher than those reported for the majority of species of Sporosarcina (36–42 mol%). As revealed by 16S rRNA gene sequence analysis, strain SK 55T and S. macmurdoensis CMS 21wT form a clade which is distinct from the clade occupied by other species of Sporosarcina. On the basis of phenotypic characteristics including chemotaxonomic data and analysis of the 16S rRNA gene sequence, we conclude that strain SK 55T should be considered as a member of a novel genus and species, for which the name Paenisporosarcina quisquiliarum gen. nov., sp. nov. is proposed. The type strain of Paenisporosarcina quisquiliarum is SK 55T (=MTCC7604T =JCM 14041T). S. macmurdoensis CMS 21wT shows more similarity in its 16S rRNA gene sequence (98.3 %), DNA G+C content and polar lipid profile to strain SK 55T than to S. ureae DSM 2281T. Phylogenetically, it forms a coherent cluster with strain SK 55T which is separate from the Sporosarcina cluster. Moreover, iso-C15 : 0, anteiso-C15 : 0 and C16 : 1 ω7c alcohol are the three major fatty acids in both S. macmurdoensis CMS 21wT and SK 55T. All these data suggest that S. macmurdoensis should be a member of the genus Paenisporosarcina. However, S. macmurdoensis can be differentiated from SK 55T in several physiological and biochemical characteristics, especially in the patterns of oxidation and acid production from carbohydrates. The genomic relatedness of S. macmurdoensis CMS 21wT and strain SK 55T was also very low (18.0 %). It is therefore logical to transfer Sporosarcina macmurdoensis to the newly created genus as Paenisporosarcina macmurdoensis comb. nov. The type strain is CMS 21wT (=MTCC4670T =DSM 15428T).

A novel aerobic, psychrotolerant, yellow-to-orange bacterium (strain 0423T) was isolated from the China No. 1 glacier. Strain 0423T displayed phenotypic and chemotaxonomic features of the genus Planomicrobium, containing anteiso-C15 : 0 and iso-C14 : 0 as the major fatty acids. The temperature range for growth was 4–28 °C, with optimum growth at 20–21 °C. The genomic DNA G+C content was 49 mol%. Phylogenetic analysis based on 16S rRNA gene sequence similarity showed that strain 0423T was related to members of the genus Planomicrobium, sharing the highest sequence similarities with the type strains of Planomicrobium chinense, P. mcmeekinii, P. okeanokoites and P. koreense. On the basis of phenotypic characteristics, phylogenetic analysis and DNA–DNA relatedness data, a novel species, Planomicrobium glaciei sp. nov., is proposed. The type strain is 0423T (=CGMCC 1.6846T =JCM 15088T).

A strictly anaerobic, Gram-positive, psychrotolerant, endospore-forming bacterium (strain A121T) was isolated from a permafrost sample collected in the Canadian High Arctic. Phylogenetic analysis of the 16S rRNA gene sequence of strain A121T showed its affiliation with the group of psychrophilic and psychrotolerant members of cluster I of the genus Clostridium, Clostridium bowmanii DSM 14206T being the closest relative (sequence similarity 98.5 %). Levels of DNA–DNA relatedness between strain A121T and the type strains of phylogenetically related species ranged from 33 to 52 %. Strain A121T grew in PY broth at temperatures between 4 and 28 °C (optimum 15–20 °C), at pH 6.0–8.0 (optimum pH 6.5–7.2) and in NaCl concentrations of 0–10.0 % (optimum 0–2.0 %). The strain utilized a narrow range of carbohydrates as sources of carbon and energy, including glucose, fructose, trehalose, maltose and starch; it also hydrolysed gelatin. Predominant fatty acids were C16 : 1 cis9, C16 : 1 cis9 DMA, C16 : 0 and C14 : 0. The DNA G+C content was 31.5 mol%. On the basis of its overall genotypic and phenotypic characteristics, strain A121T is classified within a novel species of the genus Clostridium, Clostridium tagluense sp. nov. The type strain is A121T (=VKM B-2369T =DSM 17763T).

A spore-forming, Gram-positive-staining, motile, rod-shaped and low-boron-containing bacterium was isolated from soil. The strain, designated BAM-582T, can tolerate 6 % (w/v) NaCl and 50 mM boron, but optimal growth was observed without addition of boron or NaCl. The optimum temperature and pH for growth were 30 °C (range 10–37 °C) and pH 7 (range pH 6–8). A comparative analysis of the 16S rRNA gene sequence demonstrated that the isolated strain was closely related to Lysinibacillus fusiformis DSM 2898T (97.7 % similarity) and Lysinibacillus sphaericus IAM 13420T (98.2 %). Levels of DNA–DNA relatedness were 33.9 % with L. fusiformis DSM 2898T and 29.5 % with L. sphaericus DSM 28T. The genomic DNA G+C content of the novel strain was 38.7 mol%. The major respiratory quinone was MK-7 and the major fatty acids were iso-C15 : 0 (37.4 %) and anteiso-C15 : 0 (19.0 %). Analysis of cell-wall amino acids revealed that the strain contained peptidoglycan with lysine, aspartic acid, alanine and glutamic acid, as is the case with other species of the genus Lysinibacillus. Based upon its distinctive peptidoglycan composition, phylogenetic and genotypic analyses and physiological characteristics, the strain BAM-582T is concluded to represent a novel species in the genus Lysinibacillus, for which the name Lysinibacillus parviboronicapiens sp. nov. is proposed (type strain BAM-582T =NBRC 103144T =KCTC 13154T).

A novel Gram-positive, motile, rod-shaped bacterium isolated from a saline soil in China was characterized by a polyphasic taxonomic approach. The strain, designated YC1T, was halotolerant [tolerating up to 15 % (w/v) NaCl] and alkaliphilic (growing at a broad pH range of 5–13). 16S rRNA gene sequence analysis revealed that the isolate belonged to the genus Bacillus, showing highest similarity to Bacillus macauensis JCM 13285T (98.0 %). However, DNA–DNA hybridization indicated low levels of genomic relatedness with B. macauensis JCM 13285T (8.5 %). The major isoprenoid quinone was MK-7 and the cellular fatty acid profile consisted of significant amounts of iso-C15 : 0 (38.6 %) and anteiso-C15 : 0 (35.9 %). The predominant polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The G+C content of the genomic DNA was 41.8 mol%. On the basis of the polyphasic evidence from this study, strain YC1T (=KCTC 13181T=CGMCC 1.6854T) should be classified as the type strain of a novel species of the genus Bacillus, for which the name Bacillus solisalsi sp. nov. is proposed.

A thermophilic, anaerobic, chemolithoautotrophic bacterium (designated strain SL50T) was isolated from a hydrothermal sample collected at the Mid-Atlantic Ridge from the deepest of the known World ocean hydrothermal fields, Ashadze field (1 ° 58′ 21″ N 4 ° 51′ 47″ W) at a depth of 4100 m. Cells of strain SL50T were motile, straight to bent rods with one polar flagellum, 0.5–0.6 μm in width and 3.0–3.5 μm in length. The temperature range for growth was 25–75 °C, with an optimum at 60 °C. The pH range for growth was 5.0–7.5, with an optimum at pH 6.5. Growth of strain SL50T was observed at NaCl concentrations ranging from 1.0 to 6.0 % (w/v) with an optimum at 2.5 % (w/v). The generation time under optimal growth conditions for strain SL50T was 60 min. Strain SL50T used molecular hydrogen, acetate, lactate, succinate, pyruvate and complex proteinaceous compounds as electron donors, and Fe(III), Mn(IV), nitrate or elemental sulfur as electron acceptors. The G+C content of the DNA of strain SL50T was 28.7 mol%. 16S rRNA gene sequence analysis revealed that the closest relative of strain SL50T was Deferribacter abyssi JRT (95.5 % similarity). On the basis of its physiological properties and phylogenetic analyses, the isolate is considered to represent a novel species, for which the name Deferribacter autotrophicus sp. nov. is proposed. The type strain is SL50T (=DSM 21529T=VKPM B-10097T). Deferribacter autotrophicus sp. nov. is the first described deep-sea bacterium capable of chemolithoautotrophic growth using molecular hydrogen as an electron donor and ferric iron as electron acceptor and CO2 as the carbon source.

A Gram-positive, non-motile, spherical, red-pigmented and facultatively anaerobic bacterium, designated strain I-0T, was isolated from a sand sample of the Gobi desert in Xinjiang Autonomous Region, China. Phylogenetic analysis based on 16S rRNA gene sequences indicated that this isolate represents a novel member of the genus Deinococcus, with low sequence similarities (<94 %) to recognized Deinococcus species. The major cellular fatty acids were C16 : 1 ω7c and C16 : 0. Its polar lipid profile contained several unidentified glycolipids, phosphoglycolipids, phospholipids, pigments and an aminophospholipid. The peptidoglycan type was Orn–Gly2 (A3β) and the predominant respiratory quinone was MK-8. The DNA G+C content was 65.4 mol%. DNA–DNA relatedness between strain I-0T and Deinococcus radiodurans ACCC 10492T was 37 %. The strain was shown to be extremely resistant to gamma radiation (>15 kGy) and UV light (>600 J m−2). On the basis of the phylogenetic, chemotaxonomic and phenotypic data presented, strain I-0T represents a novel species of the genus Deinococcus, for which the name Deinococcus gobiensis sp. nov. is proposed. The type strain is I-0T (=DSM 21396T =CGMCC 1.7299T).

Two heterotrophic, agarolytic bacteria were isolated from marine environments. A 16S rRNA gene sequence analysis showed the isolates (designated strains J42-3AT and 04OZ-AS15-7A) to be positioned in a separate lineage within the genus Psychromonas. Members of the genus Psychromonas are recognized as being psychrophilic or psychrotolerant, whereas none of the currently established Psychromonas species is known to be agarolytic. The DNA G+C contents of the isolates were about 42 mol% and the predominant cellular fatty acids were 16 : 1ω7c and 16 : 0. Based on the results of the phylogenetic and phenotypic analyses and DNA–DNA hybridization data, the isolates represent a novel species, for which the name Psychromonas agarivorans sp. nov. is proposed. The type strain is J42-3AT (=NBRC 104585T=KCTC 22285T).

A Gram-negative ultramicrobacterium (designated strain UMB49T) was isolated from a 120 000-year-old, 3042 m deep Greenland glacier ice core using a 0.2 μm filtration enrichment procedure. Phylogenetic analysis of the 16S rRNA gene sequence indicated that this strain belonged to the genus Herminiimonas of the family Oxalobacteraceae of the class Betaproteobacteria. Strain UMB49T was most closely related to Herminiimonas saxobsidens (99.6 % sequence similarity), Herminiimonas arsenicoxydans (98.4 %), Herminiimonas aquatilis (97.6 %) and Herminiimonas fonticola (97.9 %). Genomic DNA–DNA hybridization showed low levels of relatedness (below 57 %) to H. saxobsidens and H. arsenicoxydans. Cells of strain UMB49T were small thin rods with a mean volume of 0.043 μm3 and possessed 1 or 2 polar and/or 1–3 lateral very long flagella. The original colony pigmentation was brown-purple but after recultivation the colonies were translucent white to tan coloured. Strain UMB49T grew aerobically and under microaerophilic conditions. The strain produced catalase and oxidase, but did not reduce nitrate. Sole carbon sources included citrate, succinate, malate, lactate and alanine. The strain produced acid from l-arabinose, d-arabinose, l-xylose, d-xylose and d-ribose. The DNA G+C content was 59.0 mol%. Based on differential characteristics of strain UMB49T and recognized Herminiimonas species, it was concluded that strain UMB49T represents a novel species of the genus Herminiimonas, for which the name Herminiimonas glaciei sp. nov. is proposed. The type strain is UMB49T (=ATCC BAA-1623T=DSM 21140T).

A taxonomic study was carried out on strain B142T, which was isolated from a crude-oil-degrading microbial consortium via enrichment with deep water from the Indian Ocean. Cells of the isolate were Gram-negative, oxidase-negative, catalase-positive, helical in shape, motile by means of polar flagella (three per cell) and moderately halophilic. Growth was observed at salinities of 0.5–12 % and at temperatures of 10–41 °C. The micro-organism was capable of denitrification, but was unable to degrade Tween 80 or gelatin. The predominant fatty acids were C16 : 1 ω7c and/or iso-C15 :0 2-OH (6.4 %), C16 : 0 (15.7 %), C18 : 1 ω7c (45 %), C18 : 0 (6.8 %) and C19 : 0 ω8c cyclo (6.7 %). The G+C content of the chromosomal DNA was 67.3 mol%. Comparisons of 16S rRNA gene sequences showed that strain B142T was most closely related to the type strains of two Insolitispirillum peregrinum subspecies (93.0–93.1 % sequence similarity), two Novispirillum itersonii subspecies (92.8–92.9 %) and Caenispirillum bisanense (91.7 %); sequence similarities with respect to other taxa were below 90.5 %. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain B142T formed a distinct evolutionary lineage within the family Rhodospirillaceae. Strain B142T was distinguishable from phylogenetically related genera with regard to several phenotypic properties. On the basis of phenotypic and phylogenetic data, therefore, strain B142T represents a novel genus and species, for which the name Marispirillum indicum gen. nov., sp. nov. is proposed. The type strain is B142T (=CCTCC AB 208225T=LMG 24627T=MCCC 1A01235T).

A yellow-pigmented, moderately thermotolerant bacterial strain, designated S3-3T, was isolated from desert sand in Xinjiang province, China, and subjected to a polyphasic taxonomic characterization. This isolate was Gram-negative, aerobic and motile. Phylogenetic analyses based on the 16S rRNA gene sequence showed that strain S3-3T is phylogenetically affiliated to the genus Pseudomonas. Strain S3-3T exhibited levels of 16S rRNA gene sequence similarity of less than 96.3 % to the type strains of all Pseudomonas species, making it clear that strain S3-3T represents a species that is separate from previously recognized Pseudomonas species. Its major fatty acids were summed feature 8 (C18 : 1 ω6c and/or C18 : 1 ω7c), summed feature 3 (C16 : 1 ω7c and/or iso-C15 : 0 2-OH) and C19 : 0 cyclo ω8c. The major isoprenoid quinone was Q-9. The DNA G+C content was 60.9 mol%. On the basis of phylogenetic, phenotypic and chemotaxonomic analysis, strain S3-3T should be classified within a novel species of the genus Pseudomonas, for which the name Pseudomonas xinjiangensis sp. nov. is proposed. The type strain is S3-3T (=CCTCC AB 207151T =NRRL B-51270T).

We have made a polyphasic taxonomic study of strain 5CRT, isolated from Fuente de Piedra, Málaga, southern Spain. The strain is a moderately halophilic, Gram-negative rod, oxidase-positive and motile by a single polar flagellum. It does not produce acids from sugars and shows respiratory metabolism, using oxygen, nitrate and nitrite as terminal electron acceptors. It requires NaCl and grows best with 5–7.5 % w/v at temperatures of between 32 and 45 °C within a pH range of 6–8. Its 16S rRNA gene sequence indicates that strain 5CRT belongs to the genus Halomonas in the class Gammaproteobacteria. Its closest relatives are Halomonas alimentaria, H. nitroreducens, H. shengliensis and H. ventosae, with the type strains of which our strain showed 16S rRNA gene sequence similarity values of 96.7–97.8 %. DNA–DNA hybridization studies between strain 5CRT and H. ventosae CECT 5797T, the phylogenetically nearest type strain, showed 40 % relatedness. Its G+C content is 65.7 mol%. Its major fatty acids are C18 : 1 ω7c (31.36 %), C16 : 0 (25.55 %), C16 : 1 ω7c/iso-C15 : 0 2-OH (23.23 %), C19 : 0 cyclo ω8c (8.14 %), C12 : 0 3-OH (5.76 %) and C10 : 0 (2.22 %) and the predominant respiratory lipoquinone is ubiquinone with nine isoprene units (Q-9). The proposed name for the novel species is Halomonas fontilapidosi sp. nov., strain 5CRT (=CECT 7341T =LMG 24455T) being the type strain.

A novel strictly anaerobic, thermophilic, sulfur-reducing bacterium, designated PH1209T, was isolated from an East Pacific Rise hydrothermal vent (1 ° N) sample and studied using a polyphasic taxonomic approach. Cells were Gram-negative, motile rods (approx. 1.60×0.40 μm) with a single polar flagellum. Strain PH1209T grew at temperatures between 33 and 65 °C (optimum 60 °C), from pH 5.0 to 8.0 (optimum 6.0–6.5), and between 2 and 4 % (w/v) NaCl (optimum 3 %). Cells grew chemolithoautotrophically with H2 as an energy source, S0 as an electron acceptor and CO2 as a carbon source. Strain PH1209T was also able to use peptone and yeast extract as carbon sources. The G+C content of the genomic DNA was 35 mol%. Phylogenetic analyses based on 16S rRNA gene sequencing showed that strain PH1209T fell within the order Nautiliales, in the class Epsilonproteobacteria. Comparative 16S rRNA gene sequence analysis indicated that strain PH1209T belonged to the genus Nautilia and shared 97.2 and 98.7 % 16S rRNA gene sequence identity, respectively, with the type strains of Nautilia lithotrophica and Nautilia profundicola. It is proposed, from the polyphasic evidence, that the strain represents a novel species, Nautilia abyssi sp. nov.; the type strain is PH1209T (=DSM 21157T=JCM 15390T).