- Volume 62, Issue Pt_6, 2012

Two halophilic archaea, strains TBN53T and CSW2.24.4T, were characterized to elucidate their taxonomic status. Strain TBN53T was isolated from the Taibei marine solar saltern near Lianyungang city, Jiangsu province, China, whereas strain CSW2.24.4T was isolated from a saltern crystallizer in Victoria, Australia. Cells of the two strains were pleomorphic, stained Gram-negative and produced red-pigmented colonies. Strain TBN53T was able to grow at 25–55 °C (optimum 45 °C), with 1.4–5.1 M NaCl (optimum 2.6–3.9 M NaCl), with 0–1.0 M MgCl2 (optimum 0–0.1 M MgCl2) and at pH 5.5–9.5 (optimum pH 7.0), whereas strain CSW2.24.4T was able to grow at 25–45 °C (optimum 37 °C), with 2.6–5.1 M NaCl (optimum 3.4 M NaCl), with 0.01–0.7 M MgCl2 (optimum 0.05 M MgCl2) and at pH 5.5–9.5 (optimum pH 7.0–7.5). Cells of the two isolates lysed in distilled water. The minimum NaCl concentrations that prevented cell lysis were 8 % (w/v) for strain TBN53T and 12 % (w/v) for strain CSW2.24.4T. The major polar lipids of the two strains were phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester and phosphatidylglycerol sulfate, with two glycolipids chromatographically identical to sulfated mannosyl glucosyl diether and mannosyl glucosyl diether, respectively. Trace amounts of other unidentified lipids were also detected. On the basis of 16S rRNA gene sequence analysis, strains TBN53T and CSW2.24.4T showed 94.1 % similarity to each other and were closely related to Halobellus clavatus TNN18T (95.0 and 94.7 % similarity, respectively). Levels of rpoB′ gene sequence similarity between strains TBN53T and CSW2.24.4T, and between these strains and Halobellus clavatus TNN18T were 88.5, 88.5 and 88.1 %, respectively. The DNA G+C contents of strains TBN53T and CSW2.24.4T were 69.2 and 67.0 mol%, respectively. The level of DNA–DNA relatedness between strain TBN53T and strain CSW2.24.4T was 25 %, and these two strains showed low levels of DNA–DNA relatedness with Halobellus clavatus TNN18T (30 and 29 % relatedness, respectively). Based on these phenotypic, chemotaxonomic and phylogenetic properties, two novel species of the genus Halobellus are proposed to accommodate these two strains, Halobellus limi sp. nov. (type strain TBN53T = CGMCC 1.10331T = JCM 16811T) and Halobellus salinus sp. nov. (type strain CSW2.24.4T = DSM 18730T = CGMCC 1.10710T = JCM 14359T).

A novel red-pigmented halophilic archaeon, strain EB27T, was isolated from Aran-Bidgol salt lake, a hypersaline playa in Iran. Cells of strain EB27T were non-motile and pleomorphic (rods to triangular or disc-shaped). Strain EB27T required at least 2.5 M NaCl and 0.1 M MgCl2 for growth. Optimal growth was achieved at 4 M NaCl and 0.5 M MgCl2. The optimum pH and temperature for growth were pH 7.5 and 40 °C; it was able to grow at pH 6.0–8.0 and 25–50 °C. 16S rRNA gene sequence analysis showed that strain EB27T is a member of the family Halobacteriaceae ; however, levels of 16S rRNA gene sequence similarity were as low as 90.0, 89.3 and 89.1 % to the most closely related haloarchaeal taxa, namely Halalkalicoccus tibetensis DS12T, Halosimplex carlsbadense 2-9-1T and Halorhabdus utahensis AX-2T, respectively. The DNA G+C content of strain EB27T was 61 mol%. Strain EB27T contained phosphatidylglycerol and phosphatidylglycerol phosphate methyl ester, common phospholipids found in haloarchaea, together with two minor phospholipids. The only quinone present was MK-8(II-H2). Physiological, biochemical and phylogenetic differences between strain EB27T and recognized genera of extremely halophilic archaea suggest that this strain represents a novel species in a new genus within the family Halobacteriaceae , for which the name Halovenus aranensis gen. nov., sp. nov. is proposed. The type strain of Halovenus aranensis, the type species of the new genus, is strain EB27T ( = IBRC-M 10015T = CGMCC 1.11001T).

A novel mesophilic, hydrogenotrophic methanogen, designated strain TNRT, was isolated from an anaerobic, propionate-degradation enrichment culture that was originally established from a rice field soil sample from Taiwan. Cells were non-motile rods, 2.0–6.5 µm long by 0.3 µm wide. Filamentous (up to about 100 µm) and coccoid (about 1 µm in diameter) cells were also observed in cultures in the late exponential phase of growth. Strain TNRT grew at 20–40 °C (optimally at 37 °C), at pH 6.5–7.4 (optimally at pH 7.0) and in the presence of 0–25 g NaCl l−1 (optimally at 0 g NaCl l−1). The strain utilized H2/CO2 and formate for growth and produced methane. The G+C content of the genomic DNA was 56.4 mol%. Based on sequences of both the 16S rRNA gene and the methanogen-specific marker gene mcrA, strain TNRT was related most closely to Methanolinea tarda NOBI-1T; levels of sequence similarities were 94.8 and 86.4 %, respectively. The 16S rRNA gene sequence similarity indicates that strain TNRT and M. tarda NOBI-1T represent different species within the same genus. This is supported by shared phenotypic properties, including substrate usage and cell morphology, and differences in growth temperature. Based on these genetic and phenotypic properties, strain TNRT is considered to represent a novel species of the genus Methanolinea , for which the name Methanolinea mesophila sp. nov. is proposed; the type strain is TNRT ( = NBRC 105659T = DSM 23604T). In addition, we also suggest family status for the E1/E2 group within the order Methanomicrobiales , for which the name Methanoregulaceae fam. nov. is proposed; the type genus of family is Methanoregula.

The taxonomic position of two soil actinomycetes, strains A2012T and A2019T, isolated from Turkish soils, was determined using a polyphasic approach. Comparative 16S rRNA gene sequence analysis showed that the strains belonged to the family Nocardiaceae . Strains A2012T and A2019T were most closely related to Nocardia caishijiensis DSM 44831T (98.9 %) and Nocardia mexicana CIP 108295T (98.6 %), respectively; similarity to other type strains of the genus Nocardia ranged from 96.9 to 97.9 %. However, DNA–DNA relatedness and phenotypic data demonstrated that strains A2012T and A2019T could be clearly distinguished from members of the most closely related Nocardia species. It is evident from the genotypic and phenotypic data that the two isolates represent two novel species of the genus Nocardia . It is proposed, therefore, that strains A2012T and A2019T be classified in the genus Nocardia as representatives of Nocardia goodfellowii sp. nov. (type strain A2012T = DSM 45516T = NRRL B-24833T = KCTC 19986T) and Nocardia thraciensis sp. nov. (type strain A2019T = DSM 45517T = NRRL B-24834T = KCTC 19985T), respectively.

The taxonomic positions of three thermophilic actinomycetes isolated from arid soil samples were established by using a polyphasic approach. The organisms had chemical and morphological features that were consistent with their classification in the genus Amycolatopsis . 16S rRNA gene sequence data supported the classification of the isolates in the genus Amycolatopsis and showed that they formed distinct branches in the Amycolatopsis methanolica subclade. DNA–DNA relatedness studies between the isolates and their phylogenetic neighbours showed that they belonged to distinct genomic species. The three isolates were readily distinguished from one another and from the type strains of species classified in the A. methanolica subclade based on a combination of phenotypic properties and by genomic fingerprinting. Consequently, it is proposed that the three isolates be classified in the genus Amycolatopsis as representatives of Amycolatopsis granulosa sp. nov. (type strain GY307T = NCIMB 14709T = NRRL B-24844T), Amycolatopsis ruanii sp. nov. (type strain NMG112T = NCIMB 14711T = NRRL B-24848T) and Amycolatopsis thermalba sp. nov. (type strain SF45T = NCIMB 14705T = NRRL B-24845T).

A novel slow-growing, non-chromogenic mycobacterium (strain 01-305T) was isolated from a patient with pulmonary dysfunction. Growth characteristics, acid-fastness and the results of 16S rRNA gene sequencing supported the placement of this strain within the genus Mycobacterium . Phenotypically, strain 01-305T was generally similar to Mycobacterium triviale ATCC 23292T, but some unique biochemical characteristics were observed. The 16S rRNA gene sequence of strain 01-305T was similar to those of M. triviale ATCC 23290 (GenBank accession no. AY734996, 99.9 % similarity) and M. triviale ATCC 23291 (AY734995, 99.9 %); however, it differed substantially from that of M. triviale ATCC 23292T (X88924, 98.2 %). Phylogenetic analysis based on 16S rRNA gene sequences placed strain 01-305T in the slow-growing Mycobacterium group close to M. triviale ATCC 23290 and M. triviale ATCC 23291, but not M. triviale ATCC 23292T. Unique mycolic acid profiles and phylogenetic analysis based on two different chronometer molecules, and the hsp65 and rpoB genes, strongly supported the taxonomic status of this strain as representing a distinct species. These data support the conclusion that strain 01-305T represents a novel mycobacterial species, for which the name Mycobacterium koreense sp. nov. is proposed. The type strain is 01-305T ( = DSM 45576T  = KCTC 19819T).

Gram-positive, rod-shaped bacteria, strains Hh8T, Hh15T and Hh40-2, were isolated from the No. 1 glacier in Xinjiang, north-west China. Colonies of strain Hh8T were orange–yellow, convex and round on PYG plates. Strain Hh8T grew at 0–19 °C and pH 5.5–10.5. Colonies of strain Hh15T, which was able to grow at 0–20 °C and pH 5.5–12, were lemon yellow, convex and round on PYG plates. Phylogenetic analysis based on 16S rRNA gene sequences showed that these three strains were related to members of the genus Cryobacterium . The major cellular fatty acids of the novel strains were anteiso-C15 : 0, iso-C16 : 0, iso-C15 : 0 and anteiso-C15 : 1 A. On the basis of phenotypic characteristics, phylogenetic analysis and DNA–DNA relatedness data, two novel species, Cryobacterium flavum sp. nov. (type strain Hh8T  = CGMCC 1.11215T  = NBRC 107879T) and Cryobacterium luteum sp. nov. (type strain Hh15T  = CGMCC 1.11210T  = NBRC 107880T), are proposed.

An actinomycete, designated FXJ1.102T, was isolated from acidic soil collected in Jiangxi Province, south-east China. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain FXJ1.102T belonged to the genus Nonomuraea and was most closely related to Nonomuraea candida HMC10T, Nonomuraea turkmeniaca DSM 43926T, Nonomuraea antimicrobica YIM 61105T and ‘Nonomuraea aegyptia’ S136 (98.9, 98.3, 97.9 and 97.5 % 16S rRNA gene sequence similarities, respectively). The morphological characteristics were typical of the genus Nonomuraea . The chemotaxonomic properties, such as cell-wall chemotype IIIB, phospholipid type IV, MK-9(H4) as the major menaquinone and iso-C16 : 0 (22.2 %) as the major fatty acid, supported the assignment of the strain to the genus Nonomuraea . DNA–DNA relatedness and physiological tests allowed genotypic and phenotypic differentiation of strain FXJ1.102T from its closest phylogenetic relatives. The isolate therefore represents a novel species, for which the name Nonomuraea jiangxiensis sp. nov. is proposed. The type strain is FXJ1.102T ( = CGMCC 4.6533T = NBRC 106679T).

An actinomycete, strain L1505T, was isolated from a limnetic lake sediment and found to have morphological, biochemical, physiological and chemotaxonomic properties consistent with its classification in the genus Williamsia . Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain L1505T formed a distinct lineage within the genus Williamsia . The isolate belonged to a cluster containing W. muralis MA140/96T, W. marianensis MT8T and W. faeni N1350T, with which the isolate shared 99.0–98.2 % 16S rRNA gene sequence similarity. Genotypic and phenotypic data also indicated that the isolate was different from known members of the genus Williamsia . On the basis of these data, strain 1505T is considered to represent a novel species of the genus Williamsia , for which the name Williamsia limnetica sp. nov. is proposed (type strain L1505T = DSM 45521T = NRRL B-24829T = KCTC 19981T).

A Gram-positive, rod-shaped, xylanolytic, spore-forming bacterium, strain GTH-3T, was isolated from a tidal flat adjacent to Ganghwa Island, Republic of Korea, and was characterized to determine its taxonomic position. On the basis of 16S rRNA gene sequence similarity, strain GTH-3T was shown to belong to the family Paenibacillaceae , being most closely related to the type strains of Paenibacillus ginsengisoli (94.9 %), Paenibacillus anaericanus (94.8 %), Paenibacillus urinalis (94.4 %), Paenibacillus cookii (94.2 %), Paenibacillus alvei (94.1 %) and Paenibacillus chibensis (94.0 %). The G+C content of the genomic DNA of strain GTH-3T was 45.9±0.2 mol% (mean±sd). The major menaquinone was MK-7. The major fatty acids were anteiso-C15 : 0 and iso-C16 : 0. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. Phenotypic and chemotaxonomic data supported the affiliation of strain GTH-3T to the genus Paenibacillus . The results of physiological and biochemical tests allowed strain GTH-3T to be distinguished genotypically and phenotypically from recognized species of the genus Paenibacillus . Strain GTH-3T is therefore considered to represent a novel species of the genus Paenibacillus , for which the name Paenibacillus sediminis sp. nov. is proposed. The type strain is GTH-3T ( = DSM 23491T  = LMG 25635T).

Three enterococcal isolates, CCRI-16620, CCRI-16986T and CCRI-16985T, originating from water were characterized using morphological, biochemical and molecular taxonomic methods. 16S rRNA gene sequence analysis classified all three strains in the Enterococcus faecalis species group. The phylogenetic tree of 16S rRNA gene sequences showed that the three isolates form two separate branches. The first branch is represented by strains CCRI-16620 and CCRI-16986T and the second branch by strain CCRI-16985T. Further sequence analysis of the housekeeping genes rpoA (encoding RNA polymerase α subunit), pheS (phenylalanyl-tRNA synthase), tufA (elongation factor Tu) and atpD (ATP synthase β-subunit) as well as the results of amplified fragment length polymorphism (AFLP) DNA fingerprinting and DNA–DNA hybridization experiments confirmed the distinct status of these strains. Moreover, biochemical tests allowed phenotypic differentiation of the strains from the other species of the E. faecalis species group. On the basis of the results obtained, the names Enterococcus ureasiticus sp. nov. (type strain CCRI-16986T = CCUG 59304T = DSM 23328T = LMG 26304T) and Enterococcus quebecensis sp. nov. (type strain CCRI-16985T = CCUG 59306T = DSM 23327T = LMG 26306T) are proposed for the two hitherto undescribed species.

The taxonomy of strain CCUG 55240T, a Gram-staining-positive, aerobic, endospore-forming bacterium that was isolated from a paper mill, was investigated using a polyphasic approach. In phylogenetic analysis based on 16S rRNA gene sequences, the novel strain was grouped with established members of the genus Paenibacillus and appeared most closely related to the type strains of Paenibacillus chinjuensis (93.7 % sequence similarity), P. elgii (93.7 %) and P. chitinolyticus (93.6 %). The levels of 16S rRNA gene sequence similarity with other species of the genus Paenibacillus , including the type species of the genus, Paenibacillus polymyxa , were all <93.5 %. The fatty acid profile of strain CCUG 55240T, which showed a predominance of iso- and anteiso-branched fatty acids, supported the allocation of the strain to the genus Paenibacillus . Unusually high amounts of some iso-branched fatty acids, especially iso-C15 : 0 and iso-C16 : 0, allowed differentiation of strain CCUG 55240T from the most closely related species of the genus Paenibacillus . The diagnostic diamino acid found in the cell-wall peptidoglycan was meso-diaminopimelic acid. The predominant menaquinone was MK-7. The major polar lipids were phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, an unknown glycolipid, an unknown aminophosphoglycolipid and an unknown phospholipid. Spermidine was the major polyamine. The results of some physiological and biochemical tests also allowed the phenotypic differentiation of strain CCUG 55240T from the most closely related recognized species. On the basis of the phylogenetic, phenotypic and molecular evidence, strain CCUG 55240T represents a novel species of the genus Paenibacillus , for which the name Paenibacillus chartarius sp. nov. is proposed. The type strain of the novel species is CCUG 55240T ( = CCM 7759T).

Strain BELH1T, a novel mesophilic, anaerobic, halotolerant, rod-shaped bacterium, was isolated from a Tunisian wastewater digester. The cells of the strain are motile, measure 0.5×2–5 µm, and occur singly or in pairs. The strain reduced thiosulfate and elemental sulfur (but not sulfate or sulfite) into sulfide. It grew at 15–40 °C (optimum 30 °C), pH 5.8–8.4 (optimum 7) and with 0–10 % (w/v) NaCl (optimum 3.0 %). The genomic DNA G+C content of strain BELH1T was 38.2 mol% and the strain’s predominant cellular fatty acids were C14 : 0, asummed feature that contained iso-C17 : 1 and/or anteiso-C17 : 1 B, and C16 : 0. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the novel strain was most closely related to Fusibacter paucivorans (94.8 % sequence similarity). Based on phenotypic, phylogenetic and taxonomic characteristics, strain BELH1T represents a novel species of the genus Fusibacter , for which the name Fusibacter tunisiensis sp. nov. is proposed. The type strain is BELH1T ( = DSM 24436T = JCM 17481T).

Two anaerobic bacterial strains, designated SHI-1T and SHI-2, were isolated from chlorinated solvent-contaminated groundwater. They were found to be identical in phenotypic properties and shared high (98.5–99.8 %) pairwise 16S rRNA gene sequence similarity. Multiple 16S rRNA genes were found to be present in the isolates as well as Pelosinus fermentans DSM 17108T and Sporotalea propionica DSM 13327T. Strains SHI-1T and SHI-2 could be differentiated from their closest phylogenetic relatives, P. fermentans DSM 17108T and S. propionica DSM 13327T, on the basis of their phenotypic and phylogenetic properties. The isolates were Gram-negative, spore-forming, motile rods with peritrichous flagella. Growth occurred at 10–42 °C and pH 5.5–8.5. Fermentative growth was observed on Casamino acids, fructose, fumarate, glucose, glycerol, pyruvate and yeast extract. The major organic acids produced from glucose and glycerol fermentation were propionate and acetate. The major organic acids produced from fermentation of fumarate were propionate, acetate and succinate. The major cellular fatty acids were summed feature 4 (consisting of C15 : 1ω8c and/or C15 : 2), summed feature 8 (consisting of C17 : 1ω8c and/or C17 : 2) and C14 : 0 dimethyl aldehyde. The polar lipids comprised aminophospholipids, including phosphatidylethanolamine and phosphatidylserine, and an unknown phospholipid. The genomic DNA G+C content was 39.2 mol%. We propose that strains SHI-1T and SHI-2 are assigned to a novel species of the genus Pelosinus , with the name Pelosinus defluvii sp. nov. (type strain SHI-1T  = NRRL Y-59407T  = LMG 25549T). The description of the genus Pelosinus is emended. We also propose the transfer of S. propionica to the genus Pelosinus as Pelosinus propionicus comb. nov. (type strain TmPN3T = DSM 13327T = ATCC BAA-626T), on the basis of phylogenetic, chemotaxonomic and phenotypic properties.

A novel filamentous bacterium, strain SCSIO 10219T, was isolated from a sediment sample collected from the South China Sea (113° 3.752′ E 18° 1.722′ N) at a depth of 2105 m. Growth was observed at 25–35 °C (optimum 30 °C) and pH 5.0–8.0 (optimum pH 6.0–7.0). The organism formed yellow–white colonies with radial wrinkles. Aerial mycelium was not produced on any of the growth media tested. Phenotypic characterization and 16S rRNA gene sequence analysis indicated that strain SCSIO 10219T belongs to the family Thermoactinomycetaceae . The strain contained ll-diaminopimelic acid in the cell wall. The predominant menaquinone was MK-7. The phospholipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylmethylethanolamine, phosphatidylethanolamine and five unknown phospholipids. Major fatty acids were anteiso-C15 : 0 and iso-C15 : 0. The DNA G+C content was 46.5 mol%. On the basis of chemotaxonomic properties and phylogenetic analysis based on 16S rRNA gene sequence data, it is proposed that this strain represents a novel species in a new genus, Marininema mesophilum gen. nov., sp. nov., in the family Thermoactinomycetaceae . The type strain of the type species is SCSIO 10219T ( = CCTCC AA 2011006T = DSM 45610T). In addition, we propose that the description of the family Thermoactinomycetaceae should be further emended based on the present study.

A bacterial strain (B2-7T) capable of degrading a wide range of polycyclic aromatic hydrocarbon compounds (2–4 rings) was isolated from a water sample taken from Botan Oil Port in Xiamen, China. The isolate was Gram-negative, short-rod-shaped, aerobic, non-motile and formed yellow-pigmented colonies on LB medium. Cells of strain B2-7T were catalase-positive and oxidase-negative. Optimal growth of strain B2-7T was observed at pH 7.0, at 26 °C and in 0.5 % NaCl. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain B2-7T grouped with members of the genus Sphingomonas and it showed 16S rRNA gene sequence similarity of 95.40 % to Sphingomonas yunnanensis YIM 003T. The major polar lipids were phosphatidylethanolamine, phosphatidylcholine and sphingoglycolipid. Q-10 and sym-homospermidine were the predominant ubiquinone and polyamine components, respectively. The major fatty acids were C18 : 1ω7c (67.2 %), C14 : 0 2-OH (10.0 %) and C16 : 0 (9.6 %). The G+C content of the genomic DNA was 61.8 mol%. Based on phenotypic properties, and phylogenetic and genomic data, strain B2-7T represents a novel species of the genus Sphingomonas within the class Alphaproteobacteria , for which the name Sphingomonas polyaromaticivorans sp. nov. is proposed. The type strain is B2-7T ( = KCCM 42951T = JCM 16711T).

Thirteen novel, obligately anaerobic, thermoacidophilic bacteria were isolated from deep-sea hydrothermal vent sites. Four of the strains, designated EP5-rT, KM1, Mar08-272rT and Mar08-368r, were selected for metabolic and physiological characterization. With the exception of strain EP5-rT, all strains were short rods that grew between 40 and 72 °C, with optimal growth at 60–65 °C. Strain EP5-rT was more ovoid in shape and grew between 45 and 75 °C, with optimum growth at 60 °C. The pH range for growth of all the isolates was between pH 3.5 and 5.5 (optimum pH 4.5 to 5.0). Strain Mar08-272rT could only grow up to pH 5.0. Elemental sulfur was required for heterotrophic growth on acetate, succinate, Casamino acids and yeast extract. Strains EP5-rT, Mar08-272rT and Mar08-368r could also use fumarate, while strains EP5-rT, KM1 and Mar08-272rT could also use propionate. All isolates were able to grow chemolithotrophically on H2, CO2, sulfur and vitamins. Phylogenetic analysis of 16S rRNA gene sequences placed all isolates within the family Desulfurellaceae of the class Deltaproteobacteria , with the closest cultured relative being Hippea maritima MH2 T (~95–98 % gene sequence similarity). Phylogenetic analysis also identified several isolates with at least one intervening sequence within the 16S rRNA gene. The genomic DNA G+C contents of strains EP5-rT, KM1, Mar08-272rT and Mar08-368r were 37.1, 42.0, 35.6 and 37.9 mol%, respectively. The new isolates differed most significantly from H. maritima MH2 T in their phylogenetic placement and in that they were obligate thermoacidophiles. Based on these phylogenetic and phenotypic properties, the following two novel species are proposed: Hippea jasoniae sp. nov. (type strain Mar08-272rT = DSM 24585T = OCM 985T) and Hippea alviniae sp. nov. (type strain EP5-rT = DSM 24586T = OCM 986T).

A bacterial strain, isolated from a sample of reef-building coral (Isopora palifera) collected off the coast of southern Taiwan, was characterized using a polyphasic taxonomic approach. The strain, designated sw-2T, was Gram-staining-negative, aerobic, rod-shaped and motile, with subpolar flagella, and formed greyish pink colonies. Phylogenetic analyses based on 16S rRNA gene sequences indicated that strain sw-2T was most closely related to Roseivivax halodurans Och 239T (97.4 % sequence similarity) and Roseivivax halotolerans Och 210T (96.4 %). The novel strain did not require NaCl for growth and exhibited optimal growth at 35–40 °C, at pH 7.5–8.0 and with 3–7 % (w/v) NaCl. It produced bacteriochlorophyll a under aerobic conditions. Summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c; 63.7 %) predominated in the cellular fatty acid profile. The novel strain’s major respiratory quinone was ubiquinone Q-10 and its genomic DNA G+C content was 68.8 mol%. The polar lipid profile consisted of a mixture of phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, diphosphatidylglycerol, phosphatidyldimethylethanolamine, sulfo-quinovosyl diacylglycerol and three uncharacterized phospholipids. The level of DNA–DNA relatedness between strain sw-2T and Roseivivax halodurans Och 239T was only 15.0 %. The results of physiological and biochemical tests allowed the clear phenotypic differentiation of the novel strain from all established species of the genus Roseivivax . Based on the genotypic, phenotypic and chemotaxonomic data, strain sw-2T represents a novel species in the genus Roseivivax , for which the name Roseivivax isoporae sp. nov. is proposed. The type strain is sw-2T ( = LMG 25204T = BCRC 17966T).