- Volume 60, Issue 5, 2010

A strictly anaerobic, thermophilic bacterium, designated strain R270T, was isolated from microbial mats thriving in the thermal waters (66 °C) of a Great Artesian Basin bore (registered no. 17263) runoff channel. Cells of strain R270T were straight to slightly curved rods (3.50–6.00×0.75–1.00 μm) that stained Gram-positive, but possessed a Gram-negative cell-wall ultrastructure. Strain R270T grew optimally in tryptone-yeast extract-Casamino acids medium at 65 °C (growth temperature range between 50 and 70 °C) and at pH 7.0 (growth pH range between 6.0 and 9.0). In the presence of 0.02 and 0.10 % yeast extract, pyruvate and Casamino acids were the only substrates fermented from a wide spectrum of substrates tested. Fe(III), Mn(IV), thiosulfate and elemental sulfur were used as electron acceptors in the presence 0.2 % yeast extract, but not sulfate, sulfite, nitrate, nitrite or fumarate. Growth of strain R270T increased in the presence of Fe(III), which was reduced in the presence of peptone, tryptone, Casamino acids, amyl media, starch, pyruvate, H2 and CO2, but not in the presence of acetate, lactate, propionate, formate, benzoate, glycerol or ethanol. Growth and Fe(III) reduction were inhibited by chloramphenicol, streptomycin, tetracycline, penicillin, ampicillin and 2 % NaCl (w/v). The DNA G+C content of strain R270T was 41±1 mol% (T m) and phylogenetic analysis of the 16S rRNA gene indicated that this isolate was closely related to Thermovenabulum ferriorganovorum DSM 14006T (similarity value of 96.1 %) within the family ‘Thermoanaerobacteraceae’, class ‘Clostridia’, phylum ‘Firmicutes’. On the basis of the phylogenetic distance separating the two, together with differences in a number of key phenotypic characteristics, strain R270T represents a novel species of the genus Thermovenabulum, for which the name Thermovenabulum gondwanense sp. nov. is proposed; the type strain is R270T (=KCTC 5616T=DSM 21133T).

Four butyrate-producing isolates were obtained from the caecal content of a 4-week-old broiler chicken. The 16S rRNA gene sequences were determined and confirmed the close relatedness of the four isolates, which suggested that they were derived from a single bacterial clone. Phylogenetic analysis based on 16S rRNA gene sequences showed that its closest relatives were members of cluster XIVa of the Clostridium subphylum of Gram-positive bacteria and that the closest related type strain was Anaerostipes caccae L1-92T (94.5 % similarity). Similarity levels of 96–98 % with sequences from uncultured bacteria from human stool samples were observed. On the basis of morphological, biochemical and phylogenetic characteristics, this strain is assigned to a novel species in the genus Anaerostipes, for which the name Anaerostipes butyraticus sp. nov. is proposed. The type strain is 35-7T (=LMG 24724T =DSM 22094T). An emended description of the genus Anaerostipes is also provided.

A Gram-positive, aerobic or facultatively anaerobic, rod-shaped, spore-forming bacterium, strain Gsoil 1138T, was isolated from soil of a ginseng field in Pocheon Province, South Korea, and was characterized in order to determine its taxonomic position. On the basis of 16S rRNA gene sequence analysis, strain Gsoil 1138T was shown to belong to the family Paenibacillaceae and was most closely related to the type strains of Paenibacillus chondroitinus (98.2 % similarity) and Paenibacillus alginolyticus (96.5 %). Levels of 16S rRNA gene sequence similarity between strain Gsoil 1138T and the type strains of other recognized species of the genus Paenibacillus were below 96.5 %. The G+C content of the genomic DNA of strain Gsoil 1138T was 52.1±0.2 mol% (mean±sd of three determinations). Phenotypic and chemotaxonomic data (MK-7 as the major menaquinone and anteiso-C15 : 0 and iso-C16 : 0 as the predominant fatty acids) supported the affiliation of strain Gsoil 1138T to the genus Paenibacillus. The results of DNA–DNA hybridization experiments and physiological and biochemical tests allowed strain Gsoil 1138T to be distinguished genotypically and phenotypically from recognized species of the genus Paenibacillus. Strain Gsoil 1138T is therefore considered to represent a novel species of the genus Paenibacillus, for which the name Paenibacillus pocheonensis sp. nov. is proposed. The type strain is Gsoil 1138T (=KCTC 13941T=LMG 23404T).

Two strains of previously unknown Gram-stain-positive, anaerobic, coccus-shaped bacteria from human wound specimens were characterized using phenotypic and molecular taxonomic methods. Comparative 16S rRNA gene sequencing studies and distinguishable biochemical characteristics demonstrated that these two unknown strains, WAL 1855CT and WAL 2038E, are genotypically homogeneous and constitute a novel lineage within Clostridium cluster XIII. There was 13–14 % 16S rRNA gene sequence divergence between the novel strains and the most closely related species, Parvimonas micra, Finegoldia magna and species of Helcococcus. Based on the phenotypic and phylogenetic findings, a novel genus and species, Murdochiella asaccharolytica gen. nov., sp. nov., are proposed. Strain WAL 1855CT (=ATCC BAA-1631T =CCUG 55976T) is the type strain of Murdochiella asaccharolytica.

Two strains of pink-coloured bacteria, 5516T-9T and 5516T-11T, were isolated from an air sample collected in Korea. The taxonomic status of these novel strains was investigated by means of a polyphasic approach. The novel strains were Gram-positive, aerobic, non-spore-forming and coccus-shaped bacteria. The DNA G+C contents of strains 5516T-9T and 5516T-11T were 61.0 and 59.3 mol%, respectively. The major isoprenoid quinone for both strains was MK-8. Strain 5516T-9T contained summed feature 3 (iso-C15 : 0 2-OH and/or C16 : 1 ω7c), C16 : 0 and iso-C17 : 1 ω9c, and strain 5516T-11T contained summed feature 3, iso-C17 : 1 ω9c, C17 : 1 ω8c and C15 : 1 ω6c as the major fatty acids (>10 %). The polar lipid patterns of both strains were similar, comprising one phospholipid and one aminophospholipid as the major components. Phylogenetic analyses using 16S rRNA gene sequences showed that both novel strains were affiliated to the genus Deinococcus. Strain 5516T-9T exhibited the highest sequence similarity with Deinococcus marmoris DSM 12784T (96.8 %) and strain 5516T-11T showed the highest sequence similarity with Deinococcus saxicola DSM 15974T (94.5 %). The sequence similarity between strains 5516T-9T and 5516T-11T was 94.7 %. On the basis of the data presented, it is evident that both strains represent separate novel species of the genus Deinococcus for which the names Deinococcus aerolatus sp. nov. (type strain 5516T-9T=KACC 12745T=JCM 15442T) and Deinococcus aerophilus sp. nov. (type strain 5516T-11T=KACC 12746T=JCM 15443T) are proposed.

A Gram-negative, non-spore-forming, cream-coloured bacterial strain, UM2T, was isolated from an open hexachlorocyclohexane (HCH) dump site at Ummari village in Lucknow, India. Data generated from a polyphasic approach including phenotypic, genotypic and chemotaxonomic analyses confirmed that strain UM2T belonged to the genus Sphingomonas. The highest similarity found to the 16S rRNA gene sequence of strain UM2T was 99.4 %, with Sphingomonas wittichii DSM 6014T, whereas the DNA–DNA relatedness value between these strains was 31 %, indicating that they represent separate species. The DNA G+C content of UM2T was 66.9 mol%. The respiratory pigment ubiquinone Q-10 was present. The predominant fatty acids were summed feature 8 (C18 : 1 ω6c and/or C18 : 1 ω7c; 32.9 %), C19 : 0 cyclo ω8c (15.5 %) and C16 : 0 (12.1 %). The major polar lipids were phosphatidylcholine, phosphatidylglycerol and phosphatidyldimethylethanolamine. sym-Homospermidine was the major polyamine observed. On the basis of the data reported, it was concluded that UM2T represents a novel species of the genus Sphingomonas, for which the name Sphingomonas histidinilytica sp. nov. is proposed. The type strain is UM2T (=MTCC 9473T =CCM 7545T).

Two previously isolated strains (DSM 9103T and LPM-4T) able to grow with EDTA (facultatively and obligately, respectively) as the source of carbon, nitrogen and energy were investigated in order to clarify their taxonomic positions. The strains were strictly aerobic, Gram-negative, asporogenous and non-motile rods that required biotin for growth. Reproduction occurred by binary fission. The strains were mesophilic and neutrophilic. Their major fatty acids were summed feature 7 (consisting of C18 : 1 ω7c, C18 : 1 ω9t and/or C18 : 1 ω12t) and C19 : 0 cyclo ω8c. The polyamine pattern revealed homospermidine as a major polyamine. Predominant polar lipids were phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine, phosphatidyldimethylethanolamine, phosphatidylmonomethylethanolamine and diphosphatidylglycerol. Mesorhizobium-specific ornithine lipid was absent. The predominant isoprenoid quinone was Q-10. The DNA G+C values were 60.8 and 63.1 mol% (T m) for strains LPM-4T and DSM 9103T, respectively. The level of 16S rRNA gene sequence similarity between these EDTA-utilizers was 99.3 % while the DNA–DNA hybridization value was only 37 %. Both strains were phylogenetically related to members of the genera Aminobacter and Mesorhizobium (95–97 % sequence similarity). However, DNA–DNA hybridization values between the novel EDTA-degrading strains and Aminobacter aminovorans DSM 7048T and Mesorhizobium loti DSM 2626T were low (10–11 %). Based on their genomic and phenotypic properties, the new alphaproteobacterial strains are assigned to a novel genus, Chelativorans gen. nov., with the names Chelativorans multitrophicus sp. nov. (type strain DSM 9103T=VKM B-2394T) and Chelativorans oligotrophicus sp. nov. (type strain LPM-4T=VKM B-2395T=DSM 19276T).

A novel bacterium, designated strain HT27T, was isolated from a sulfur spring sample collected from Athamallik, Orissa, India, and was characterized by using a polyphasic approach. Cells were Gram-negative, strictly aerobic, rod-shaped and motile by means of a single polar flagellum. Strain HT27T was oxidase- and catalase-positive. Growth was observed at pH 5.0–11.0 and at 15–45 °C; the highest growth yield was observed at pH 7.5–8.0 and 30–37 °C. The G+C content of the genomic DNA of strain HT27T was 63 mol%. The major cellular fatty acids were C16 : 1 ω7c (44.24 %), C16 : 0 (27.65 %), C18 : 1 ω7c (13.98 %), C12 : 0 (2.60 %) and C12 : 0 3-OH (2.22 %). 16S rRNA gene sequence analysis indicated that strain HT27T clustered with the genus Gulbenkiania and showed 99.0 % similarity to Gulbenkiania mobilis E4FC31T. However, the level of DNA–DNA relatedness between strain HT27T and G. mobilis E4FC31T was 30 %. On the basis of phenotypic and chemotaxonomic characteristics, 16S rRNA gene sequence analysis and DNA–DNA hybridization data, strain HT27T is considered to represent a novel species of the genus Gulbenkiania, for which the name Gulbenkiania indica sp. nov. is proposed. The type strain is HT27T (=DSM 17901T =JCM 15969T).

A novel halophilic Gram-negative sulfate-reducing bacterium affiliated with the deltaproteobacterial family Desulfobacteraceae, strain PropAT, was isolated from the extreme hypersaline sediment of the northern arm of Great Salt Lake, Utah, USA. Comparative 16S rRNA gene sequence analysis showed that strain PropAT is the first cultured representative of a clade of phylotypes that have been retrieved from a range of geographically and ecologically distinct hypersaline environments. Strain PropAT shared ≤90 % 16S rRNA gene sequence identity with cultured strains within the family Desulfobacteraceae. Cells of strain PropAT were rod-shaped and sometimes motile. The strain required NaCl for growth and grew at salinities up to 200 g NaCl l−1 (optimum 60 g l−1). Growth was observed at 15–40 °C, optimum growth occurred at about 40 °C, while growth was absent at 10 and 45 °C. The pH range for growth was pH 6.0–8.3. Yeast extract (0.1 g l−1) was required for growth. C2–4 alcohols, C3–4 carboxylic acids, yeast extract and H2/acetate supported growth with sulfate as electron acceptor. Sulfate, thiosulfate and sulfite served as electron acceptors, but not elemental sulfur, nitrate or fumarate. The DNA G+C content of strain PropAT was 54.1 mol%. Based on the genotypic and physiological properties, we propose that strain PropAT represents a novel species within a novel genus, Desulfosalsimonas propionicica gen. nov., sp. nov. The type strain of Desulfosalsimonas propionicica is PropAT (=DSM 17721T =VKM B-2385T).

An anoxygenic, phototrophic gammaproteobacterium designated strain JA418T was isolated from a sediment sample collected from the Baitarani River, Orissa, India. The bacterium was a Gram-negative, motile rod with a single polar flagellum. Bacteriochlorophyll a and rhodopin were the major photosynthetic pigments. The organism grew best at slightly alkaline pH (8–8.5) and lacked chemotrophic growth. The major fatty acids were C16 : 0, C16 : 1 ω7c/C16 : 1 ω6c and C18 : 1 ω7c. A phylogenetic tree based on 16S rRNA gene sequence analysis showed that strain JA418T clusters with species of the genus Marichromatium belonging to the class Gammaproteobacteria. The highest 16S rRNA gene sequence similarities of strain JA418T were found with the type strains of Marichromatium gracile (95.9 %), Marichromatium indicum (95.6 %), Marichromatium purpuratum (95.5 %) and Marichromatium bheemlicum (95.6 %). The DNA base composition of strain JA418T was 71.4 mol% G+C (by HPLC). Based on the 16S rRNA gene sequence analysis and physiological and chemotaxonomic characteristics, strain JA418T is sufficiently different from other Marichromatium species to merit the description of a novel species, Marichromatium fluminis sp. nov., to accommodate it. The type strain is JA418T (=KCTC 5717T =NBRC 105221T).

A Gram-negative-staining, aerobic, non-motile and rod-shaped bacterial strain, S5-5T, was isolated from a tidal flat sediment at Saemankum on the west coast of Korea and subjected to a polyphasic taxonomic investigation. Strain S5-5T grew optimally at pH 7.5–8.0, at 30 °C and in the presence of 2 % (w/v) NaCl. It did not produce bacteriochlorophyll a. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain S5-5T is phylogenetically closely related to the genus Roseivivax, joining the cluster comprising the two recognized Roseivivax species. The 16S rRNA gene sequence similarity between strain S5-5T and members of the genus Roseivivax was in the range 95.0–96.7 %. Strain S5-5T contained Q-10 as the predominant ubiquinone and C18 : 1 ω7c and 11-methyl C18 : 1 ω7c as the major fatty acids. The DNA G+C content was 68.2 mol%. Differential phenotypic properties, together with the phylogenetic distinctiveness, demonstrated that strain S5-5T could be differentiated from Roseivivax species. On the basis of the data presented, strain S5-5T is considered to represent a novel species of the genus Roseivivax, for which the name Roseivivax lentus sp. nov. is proposed. The type strain is S5-5T (=KCTC 22708T =CCUG 57755T).

A polycyclic aromatic hydrocarbon-degrading marine bacterium, designated strain P-4T, was isolated from oil-polluted saline soil in Xianhe, Shangdong Province, China. Strain P-4T was Gram-negative-staining with curved to spiral rod-shaped cells and grew optimally with 3–6 % (w/v) NaCl and at 30 °C. The predominant fatty acids were C18 : 1 ω7c (35.0 %), C16 : 0 (25.0 %), C16 : 1 ω7c (17.9 %), C14 : 0 (6.2 %) and C17 : 0 cyclo (5.2 %). The major respiratory quinone was Q-9 and the genomic DNA G+C content was 61.2±1.0 mol%. Phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain P-4T belonged to the genus Thalassospira of the class Alphaproteobacteria. DNA–DNA hybridization with Thalassospira xiamenensis DSM 17429T showed relatedness of 36.0 %, and lower values were obtained with respect to other Thalassospira species. Based on physiological and biochemical tests and 16S rRNA gene sequence analysis as well as DNA–DNA relatedness, strain P-4T should be placed in the genus Thalassospira within a novel species. The name Thalassospira xianhensis sp. nov. is proposed, with P-4T (=CGMCC 1.6849T =JCM 14850T) as the type strain.

Nitrogen-fixing bacteria, strains SA41T, SA42 and SA53, were isolated from an aquatic plant, Eleocharis dulcis, that grows in highly acidic swamps (pH 2–4) in actual acid sulfate soil areas of Vietnam. The isolates were Gram-negative, aerobic, non-spore-forming, rod-shaped bacteria, having a cell width of 0.6–0.7 μm and a length of 1.5–1.7 μm. They showed good growth between pH 3.0 and 7.0, and between 17 and 37 °C. The organisms contained ubiquinone Q-8 as the predominant isoprenoid quinone, and C16 : 0, C17 : 0 cyclo, C18 : 1 ω7c and summed feature 3 (C16 : 1 ω7c and/or iso-C15 : 0 2-OH) as major fatty acids. Their fatty acid profiles are similar to those reported for other Burkholderia species. The DNA G+C content of these strains was 64 mol%. On the basis of 16S rRNA gene sequence similarity, these strains were shown to belong to the genus Burkholderia. Although their calculated 16S rRNA gene sequence similarity values to Burkholderia silvatlantica, Burkholderia mimosarum, Burkholderia ferrariae and Burkholderia tropica were 98.5, 98.2, 98.0 and 97.0 %, respectively, the isolates formed a distinct group in phylogenetic trees, and the DNA–DNA relatedness values of strain SA41T to these species were 39, 41, 39 and 33 %, respectively. The results of physiological and biochemical tests, including whole-cell protein pattern analysis, allowed phenotypic differentiation of these strains from the published Burkholderia species. Therefore, strains SA41T, SA42 and SA53 represent a novel species for which the name Burkholderia heleia sp. nov. is proposed. The type strain is SA41T (=NBRC 101817T=VTCC-D6-7T).

A Gram-negative, aerobic, rod-shaped bacterium, designated strain CL-33T, was isolated from the encrusting pore coral Montipora aequituberculata collected from seawater off the coast of southern Taiwan. 16S rRNA gene sequence analysis showed that the strain clustered closely with Endozoicomonas elysicola MKT110T (96.7 % similarity). The novel strain required NaCl for growth and exhibited optimal growth at 25 °C and in the presence of 2–3 % NaCl. Predominant cellular fatty acids were summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c; 39.6 %), summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c; 32.8 %) and C16 : 0 (12.0 %). The DNA G+C content of strain CL-33T was 50.0 mol%. The results of physiological and biochemical tests allowed the clear phenotypic differentiation of this isolate from E. elysicola. It is evident from the genotypic, phenotypic and chemotaxonomic data presented that strain CL-33T represents a novel species of the genus Endozoicomonas, for which the name Endozoicomonas montiporae sp. nov. is proposed. The type strain is CL-33T (=LMG 24815T =BCRC 17933T).

A Gram-negative-staining, non-motile and rod-shaped bacterial strain, HD-43T, was isolated from a tidal flat sediment collected from Hwang-do, an island of Korea. Strain HD-43T grew optimally at pH 7.0–8.0, at 30 °C and in the presence of 2 % (w/v) NaCl. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain HD-43T clustered with Pseudoruegeria aquimaris SW-255T. It exhibited 96.6 % 16S rRNA gene sequence similarity and 79.4 % gyrB sequence similarity with P. aquimaris SW-255T. Strain HD-43T contained Q-10 as the predominant ubiquinone and C18 : 1 ω7c as the major fatty acid. The major polar lipids were phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine, an unidentified aminolipid, an unidentified glycolipid and an unidentified lipid. The DNA G+C content was 73.5 mol%. The mean DNA–DNA relatedness between strain HD-43T and P. aquimaris SW-255T was 5 %. Differential phenotypic properties demonstrated that strain HD-43T is clearly distinguishable from P. aquimaris. On the basis of phenotypic, chemotaxonomic and phylogenetic data, strain HD-43T is considered to represent a novel species of the genus Pseudoruegeria, for which the name Pseudoruegeria lutimaris sp. nov. is proposed. The type strain is HD-43T (=KCTC 22690T =CCUG 57754T).

A thermophilic, anaerobic, chemosynthetic bacterium, designated strain MB-1T, was isolated from the walls of an active deep-sea hydrothermal vent chimney on the East Pacific Rise at  ° 50′ N 10 ° 17′ W. The cells were Gram-negative-staining rods, approximately 1–1.5 μm long and 0.3–0.5 μm wide. Strain MB-1T grew at 25–65 °C (optimum 55 °C), with 10–35 g NaCl l−1 (optimum 20 g l−1) and at pH 4.5–8.5 (optimum pH 7.0). Generation time under optimal conditions was 45.6 min. Growth occurred under chemolithoautotrophic conditions with H2 as the energy source and CO2 as the carbon source. Nitrate was used as the electron acceptor, with resulting production of ammonium. Thiosulfate, sulfur and selenate were also used as electron acceptors. No growth was observed in the presence of lactate, peptone or tryptone. Chemo-organotrophic growth occurred in the presence of acetate, formate, Casamino acids, sucrose, galactose and yeast extract under a N2/CO2 gas phase. The G+C content of the genomic DNA was 36.0 mol%. Phylogenetic analysis of the 16S rRNA gene sequence indicated that this organism is closely related to Nautilia profundicola AmHT, Nautilia abyssi PH1209T and Nautilia lithotrophica 525T (95, 94 and 93 % sequence identity, respectively). On the basis of phylogenetic, physiological and genetic considerations, it is proposed that the organism represents a novel species within the genus Nautilia, Nautilia nitratireducens sp. nov. The type strain is MB-1T (=DSM 22087T =JCM 15746T).

Seven strains of purple nonsulfur bacteria isolated from the shallow-water steppe soda lakes of the cryoarid zone of Central Asia formed a genetically homogeneous group within the genus Rhodovulum. The isolates were most closely related to Rhodovulum strictum, from which they differed at the species level (99.5 % 16S rRNA gene identity and 42–44 % DNA–DNA hybridization level). According to genotypic and phenotypic characteristics, the strains were assigned to a new species of the genus Rhodovulum, for which the name Rhodovulum steppense sp. nov. is proposed. Cells of all strains were ovoid to rod-shaped, 0.3–0.8 μm wide and 1–2.5 μm long, and motile by means of polar flagella. They contained internal photosynthetic membranes of the vesicular type and photosynthetic pigments (bacteriochlorophyll a and carotenoids of the spheroidene series). All strains were obligate haloalkaliphiles, growing within a wide range of salinity (0.3–10 %) and pH (7.5–10), with growth optima at 1–5 % NaCl and pH 8.5. Photo- and chemoheterotrophic growth occurred with a number of organic compounds and biotin, thiamine and niacin as growth factors. No anaerobic respiration on nitrite, nitrate or fumarate and no fermentation was demonstrated. Bacteria grew photo- and chemolithoautotrophically with sulfide, sulfur and thiosulfate, oxidizing them to sulfate. Sulfide was oxidized via deposition of extracellular elemental sulfur. No growth with H2 as electron donor was demonstrated. The major fatty acid was 18 : 1 (81.0 %). The major quinone was Q-10. The DNA G+C content was 66.1 mol% (T m). The type strain, A-20sT (=VKM B-2489T =DSM 21153T), was isolated from soda lake Khilganta (Zabaikal'skii Krai, southern Siberia, Russia).

Three isolates, typified by Pro94 Y29T (=JCM 13290T =CBS 9278T =DBVPG 7841T), that represent a novel species, Rhodotorula arctica sp. nov., were studied. R. arctica differed from its only close relative, Bensingtonia yamatoana, by requiring thiamine and by failing to assimilate maltose and quinate, but strain Pro94 Y29T could be most readily identified using the rDNA sequence of the LSU D1/D2 region, which differed from that of B. yamatoana CBS 7423T at four positions, and the ITS sequence, which differed at nine positions. One R. arctica isolate, Pro94 Y56 (=JCM 13292 =CBS 9280 =DBVPG Y7843), was unique in requiring either l-arginine or l-citrulline as a source of nitrogen.

Two yeast strains (FMCC Y-1T and FMCC Y-2) were recovered during a survey of the yeast biota associated with fermenting black olives, collected from an olive tree (Olea europaea L. cv. ‘Conservolea’) orchard in Central Greece. Phylogenetic analysis based on rRNA gene sequences (18S, 26S, and 5.8S–ITS) indicated that the two strains represent a separate species within the Candida membranifaciens clade, in close relation to Candida blattariae NRRL Y-27703T. Electrophoretic karyotyping and physiological analysis support the affiliation of the two strains to a novel species as Candida olivae sp. nov. The novel strains are conspecific with two Candida sp. strains previously isolated from the Mid-Atlantic Ridge hydrothermal fields [Gadanho & Sampaio (2005). Microb Ecol 50, 408–417], indicating that Candida olivae sp. nov. may occupy diverse ecological niches. FMCC Y-1T (=CBS 11171T =ATCC MYA-4568T) is the type strain.