- Volume 57, Issue 3, 2007

The taxonomic status of a bacterium designated strain IMMIB SR-4T isolated from an oil-contaminated soil sample was characterized by using a polyphasic approach. Chemotaxonomic investigations revealed the presence of cell-wall chemotype IV, short-chain mycolic acids that co-migrated with those extracted from members of the genus Williamsia and that on pyrolysis GC produce C16 : 0 and C18 : 0 fatty acids, and dihydrogenated menaquinone with nine isoprene units as the predominant menaquinone. The generic assignment was confirmed by 16S rRNA gene sequence analysis. Comparative analysis of the 16S rRNA gene sequence showed that strain IMMIB SR-4T formed a distinct phyletic line within the genus Williamsia, displaying sequence similarities of 95.5–98.1 % with the type strains of recognized Williamsia species. Strain IMMIB SR-4T was distinguished from the type strains of recognized species of the genus Williamsia based on a set of phenotypic features. The genotypic and phenotypic data indicated that strain IMMIB SR-4T represents a novel species of the genus Williamsia, for which the name Williamsia serinedens sp. nov. is proposed. The type strain is IMMIB SR-4T (=DSM 45037T=CCUG 53151T).

Two Gram-positive, non-motile, yellow-pigmented, slightly curved and rod-shaped bacterial strains, UMS-62T and UMS-101, were isolated from the rhizosphere of Allium victorialis var. platyphyllum, a variety of wild edible greens grown on Ulleung island, Korea. The taxonomic position of the strains was investigated by a polyphasic approach. Strains UMS-62T and UMS-101 grew optimally at 30 °C and at pH 6.5–7.5. The novel strains contained MK-11 and MK-12 as the predominant menaquinones and rhamnose, ribose and galactose as the major cell-wall sugars. The major cellular fatty acids (>10 % of the total fatty acids) were anteiso-C15 : 0, iso-C16 : 0 and anteiso-C17 : 0. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and an unidentified glycolipid. The DNA G+C contents were 71.1–71.3 mol%. Phylogenetic trees based on 16S rRNA gene sequences showed that strains UMS-62T and UMS-101 belong to the genus Agromyces. Strains UMS-62T and UMS-101 showed a 16S rRNA gene sequence similarity value of 99.9 % and a mean DNA–DNA relatedness level of 91.1 %. Similarity values between the 16S rRNA gene sequences of the two novel strains and the type strains of recognized Agromyces species ranged from 95.2 to 99.1 %. The levels of DNA–DNA relatedness between the two novel strains and the type strains of five phylogenetically related Agromyces species were in the range of 13.4 to 54.2 %. On the basis of phenotypic properties, phylogenetic distinctiveness and genetic data, strain UMS-62T (=KCTC 19181T=JCM 13584T) and strain UMS-101 are classified as representing a novel species in the genus Agromyces, for which the name Agromyces allii sp. nov. is proposed.

A previously undescribed, slowly growing, scotochromogenic mycobacterium was isolated from a patient with symptomatic pulmonary infection during hsp65 sequence-based identification of Korean clinical isolates. Phenetic characteristics of this strain were generally similar to those of Mycobacterium nebraskense and Mycobacterium scrofulaceum. However, some phenetic characteristics differentiated it from these two species. Its 16S rRNA gene sequences were unique and phylogenetic analysis based on 16S rRNA gene sequences placed the organism in the slowly growing Mycobacterium group close to M. nebraskense and M. scrofulaceum. Its unique mycolic acid profiles and the results of phylogenetic analysis based on two independent alternative chronometer molecules, hsp65 and rpoB, confirmed the taxonomic status of this strain as representing a novel species. These data support the conclusion that this strain represents a novel mycobacterial species, for which the name Mycobacterium seoulense sp. nov. is proposed. The type strain is strain 03-19T (=DSM 44998T=KCTC 19146T).

The taxonomic position of strain SD29T, isolated from soil, was clarified using a polyphasic taxonomic approach. The organism produced an elementary branching mycelium which fragmented into rod/coccus-shaped elements and it possessed meso-diaminopimelic acid, arabinose, galactose as diagnostic diamino acid and sugars, MK-9(H2) as predominant menaquinone, phospholipids of type PII and mycolic acid. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain SD29T was most closely related to Gordonia hydrophobica DSM 44015T and Gordonia sihwensis DSM 44576T, forming a distinct but loosely related branch in the phylogenetic tree. A number of physiological properties readily separated the isolate from its nearest neighbours. It is evident from genotypic and phenotypic data that strain SD29T represents a novel species of the genus Gordonia, for which the name Gordonia shandongensis sp. nov. is proposed. The type strain is SD29T (=CGMCC 4.3492T=JCM 13907T).

A fast-growing and cell-fusing hyperthermophilic archaeon was isolated from a hydrothermal vent at Suiyo Seamount, Izu-Bonin Arc, Western Pacific Ocean. Strain TS2T is an irregular, motile coccus that is generally 0.7–1.5 μm in diameter and possesses a polar tuft of flagella. In the mid-exponential phase of growth, cells that appeared black under phase-contrast microscopy fused at room temperature in the presence of a DNA-intercalating dye, as previously observed in Thermococcus coalescens. Cell fusion was not observed in later growth phases. Transmission electron microscopy revealed that the cells in the mid-exponential phase had a 5 nm-thick, electron-dense cell envelope that appeared to associate loosely with the cytoplasmic membrane. As the growth stage progressed, a surface layer developed on the membrane under the envelope and the envelope eventually peeled off. These observations suggest that the surface layer prevents the fusion of cells. Cells of strain TS2T grew at 50–85 °C, pH 5.6–8.3 and at NaCl concentrations of 1.0 to 4.5 %, with optimal growth occurring at 80 °C, pH 7.0 and 3.0 % NaCl. Under optimal growth conditions, strain TS2T grew very fast with an apparent doubling time of 20 min. It is suggested that the biosynthesis of the surface layer cannot catch up with cell multiplication in the mid-exponential phase and thus cells without the surface layer are generated. Strain TS2T was an anaerobic chemo-organotroph that grew on either yeast extract or tryptone as the sole growth substrate. The genomic DNA G+C content was 54.6 mol%. Phylogenetic analysis based on 16S rRNA gene sequencing indicated that the isolate belongs to the genus Thermococcus. However, no significant DNA–DNA hybridization was observed between the genomic DNA of strain TS2T and phylogenetically related Thermococcus species. On the basis of this evidence, strain TS2T is proposed to represent a novel species, Thermococcus celericrescens sp. nov., a name chosen to reflect the fast growth of the strain. The type strain is TS2T (=NBRC 101555T=JCM 13640T=DSM 17994T).

Four formate-utilizing methanogens were isolated from ovine (strain KM1H5-1PT) and bovine (strains AK-87, OCP and ZA-10T) rumen contents. Based on 16S rRNA gene sequence analysis, the methanogen strains were found to belong to the order Methanobacteriales in the genus Methanobrevibacter. Strains ZA-10T and KM1H5-1PT gained energy for growth by the reduction of CO2 to CH4 using H2 or formate exclusively as electron donors. Increasing formate concentrations to 220 mM in batch cultures increased the growth of strain KM1H5-1PT but did not affect the growth of strain ZA-10T. Substrate specificity and resistance to cell-wall lysis supported the affiliation of the strains to the genus Methanobrevibacter. Strains ZA-10T and KM1H5-1PT showed 16S rRNA gene sequence similarity of 98.0 and 98.6 % to their closest recognized relatives, Methanobrevibacter thaueri CWT and Methanobrevibacter ruminantium M1T, respectively. DNA–DNA hybridization experiments indicated that the strains were not affiliated at the species level to their closest recognized relatives, with DNA reassociation values of only 28 % between strains ZA-10T and Methanobrevibacter thaueri CWT and <25 % between strains KM1H5-1PT and Methanobrevibacter ruminantium M1T. Based on the data presented, the new strains are considered to represent two novel species of the genus Methanobrevibacter, for which the names Methanobrevibacter millerae sp. nov. (type strain ZA-10T=DSM 16643T=OCM 820T) and Methanobrevibacter olleyae sp. nov. (type strain KM1H5-1PT=DSM 16632T=OCM 841T) are proposed.

A Gram-negative, extremely halophilic, coccoid archaeal strain, CM5T, was isolated from a crude sea-salt sample collected near Qingdao, China. The organism grew optimally at 35–40 °C and pH 6.0 in the presence of 20 % (w/v) NaCl. Its colonies were red in colour and it could use glucose as a sole carbon source for growth. The 16S rRNA gene sequence of CM5T was most closely related to those of Halococcus species. Its pattern of antibiotic susceptibility was similar to those of other described Halococcus species. Biochemical tests revealed no sign of H2S production or gelatin liquefaction. The main polar lipids of strain CM5T were phosphatidylglycerol, phosphatidylglycerol methylphosphate and sulfated diglycosyl diether. No phosphatidylglycerol sulfate was present. The DNA G+C content of strain CM5T was 61.2 mol% and it gave DNA–DNA reassociation values of 33.7, 57.1 and 29.6 %, respectively, with Halococcus salifodinae DSM 8989T, Halococcus dombrowskii DSM 14522T and Halococcus morrhuae ATCC 17082T. Based on its morphological and chemotaxonomic properties and phylogenetic analysis of 16S rRNA gene sequence data, we propose that CM5T should be classified within a novel species, Halococcus qingdaonensis sp. nov., with strain CM5T (=CGMCC 1.4243T=JCM 13587T) as the type strain.

An aerobic, Gram-negative, non-motile, yellow-pigmented bacterium, strain KMM 3046T, was isolated from a deep-sea brittle star from the Fiji Sea and was subjected to a polyphasic taxonomic analysis. Strain KMM 3046T grew at 5–32 °C and in the presence of 1–12 % (w/v) NaCl. It contained MK-6 as the predominant menaquinone and 3-OH i16 : 0, 3-OH i17 : 0 and 3-OH a17 : 0 as the major fatty acids. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain KMM 3046T forms a distinct evolutionary lineage within the family Flavobacteriaceae (phylum Bacteroidetes), displaying 92.3–91.9 % sequence similarity with respect to Salegentibacter species. On the basis of the phenotypic and phylogenetic data, strain KMM 3046T represents a novel genus and species of the family Flavobacteriaceae, for which the name Marixanthomonas ophiurae gen. nov., sp. nov. is proposed. The type strain of Marixanthomonas ophiurae is KMM 3046T (=NRIC 0684T=JCM 14121T).

A mesophilic bacterium, strain 15-52T, was isolated from the rhizosphere of Chinese cabbage (Brassica campestris). On the basis of phenotypic and genotypic characteristics, the bacterium was identified as representing a novel species belonging to the genus Pedobacter. The strain is non-flagellated, non-spore-forming and grows at temperatures in the range 1–37 °C. Physiological tests of the strain showed the presence of oxidase, catalase, protease (gelatin and casein hydrolysis), β-glucosidase and β-galactosidase activities. The highest levels of 16S rRNA gene sequence similarity were found with respect to Pedobacter roseus CL-GP80T (97.3 %) and Pedobacter sandarakinus DS-27T (97.2 %). A phylogenetic analysis based on 16S rRNA gene sequence data indicated that strain 15-52T is a member of the genus Pedobacter. DNA–DNA hybridization analysis revealed low levels of relatedness (<42.3 %) between the isolate and two phylogenetically related type strains, P. roseus KCCM 42272T and P. sandarakinus KCTC 12559T. The DNA G+C content is 44.2 mol% and the predominant fatty acids are iso-C15 : 0 (35.4 %), iso-C15 : 0 2-OH and/or C16 : 1 ω7c (27.8 %) and iso-C17 : 0 3-OH (15.8 %). On the basis of these data, strain 15-52T represents a novel species of the genus Pedobacter, for which the name Pedobacter suwonensis sp. nov. is proposed. The type strain is 15-52T (=KACC 11317T=DSM 18130T).

An orange-coloured bacterial strain, designated R2A15-11T, was isolated from greenhouse soil. The strain was found to be strictly aerobic, Gram-negative, non-spore-forming and non-flagellated. The cells were short rods (0.7–0.9×1.0–1.5 μm) and produced flexirubin. Growth of the strain was observed at 10–35 °C, pH 5.0–8.0 and 0–3 % (w/v) NaCl. The predominant isoprenoid quinone was MK-7. The major fatty acids were iso-C15 : 0, iso-C15 : 1 G, iso-C17 : 0 3-OH and summed feature 3 (comprising iso-C15 : 0 2-OH and/or C16 : 1 ω7c). The genomic DNA G+C content was 45.0 mol%. Phylogenetic analysis of the 16S rRNA gene sequence of strain R2A15-11T revealed a clear affiliation with the phylum Bacteroidetes, and the highest levels of sequence similarity were found with respect to Terrimonas ferruginea ATCC 13524T (91.5 %), Terrimonas lutea DYT (90.2 %), Niastella yeongjuensis GR20-13T (89.9 %) and Niastella koreensis GR20-10T (89.7 %). On the basis of the polyphasic evidence from this study, strain R2A15-11T represents a novel genus and species, for which the name Niabella aurantiaca gen. nov., sp. nov. is proposed. The type strain of Niabella aurantiaca is R2A15-11T (=KACC 11698T=DSM 17617T).

A novel thermophilic and sulfur-reducing heterotrophic bacterium, strain TFS10-5T, was isolated from a deep-sea hydrothermal field in Yonaguni Knoll IV, Southern Okinawa Trough. Cells of strain TFS10-5T were motile rods, 1.5–5 μm in length and 0.5–0.8 μm in width. Strain TFS10-5T was an obligately anaerobic heterotroph and sulfur-reduction stimulated growth. Growth was observed between 30 and 70 °C (optimum at 55–60 °C), pH 5.0–7.4 (optimum at pH 5.5–5.8), 1.0–5.5 NaCl % (optimum at 3.0–3.5 %). The fatty acid content was C16 : 0 (71.0 %), C16 : 1 (6.0 %), C18 : 0 (21.4 %) and C18 : 1 (1.6 %). The G+C content of the genomic DNA was 28 mol%. 16S rRNA gene sequence analysis indicated that strain TFS10-5T belongs to the genus Marinitoga. Based on the physiological and phylogenetic features of the new isolate, strain TFS10-5T represents a novel species in the genus Marinitoga for which the name Marinitoga okinawensis sp. nov. is proposed. The type strain is TFS10-5T (=JCM 13303T=DSM 17373T).

A Gram-negative, chemoheterotrophic, facultatively anaerobic coccus, designated IMCC1545T, was isolated from the digestive tract of a marine clamworm, Periserrula leucophryna, inhabiting a tidal flat of the Yellow Sea. Cells of strain IMCC1545T are non-motile, dividing by binary fission. The predominant fatty acids are anteiso-C15 : 0 and C18 : 0. The respiratory quinone is menaquinone-7 and the DNA G+C content is 52.1 mol%. Phylogenetic analyses based on 16S rRNA gene sequences using three treeing algorithms revealed that the strain formed a novel genus-level lineage within the phylum ‘Verrucomicrobia’. The most closely related named organisms to strain IMCC1545T are ‘Fucophilus fucoidanolyticus’ SI-1234 (86.5 % 16S rRNA gene sequence similarity), Alterococcus agarolyticus ADT3T (81.8 %) and Opitutus terrae PB90-1T (80.3 %), which belong to subdivision 4 of the ‘Verrucomicrobia’. Subdivision 4 of the ‘Verrucomicrobia’ (here named Opitutae classis nov.) was divided into two clades, a clade containing strain IMCC1545T and a clade containing Opitutus terrae. From the taxonomic data obtained in this study, it is proposed that the new marine isolate be placed into a novel genus and species named Puniceicoccus vermicola gen. nov., sp. nov. (the type strain of Puniceicoccus vermicola is IMCC1545T=KCCM 42343T=NBRC 101964T) within Puniceicoccaceae fam. nov and Puniceicoccales ord. nov in the class Opitutae. The family Opitutaceae fam. nov. and order Opitutales ord. nov. are also formally proposed.

Reclassification of the species Trichlorobacter thiogenes as Geobacter thiogenes comb. nov. is proposed on the basis of physiological traits and phylogenetic position. Characteristics additional to those provided in the original description revealed that the type strain (strain K1T=ATCC BAA-34T=JCM 14045T) has the ability to use Fe(III) as an electron acceptor for acetate oxidation and has an electron donor and acceptor profile typical of a Geobacter species, contains abundant c-type cytochromes, and has a temperature optimum of 30 °C and a pH optimum near pH 7.0; traits typical of members of the genus Geobacter. Phylogenetic analysis of nifD, recA, gyrB, rpoB, fusA and 16S rRNA genes further indicated that T. thiogenes falls within the Geobacter cluster of the family Geobacteraceae. Based on extensive phylogenetic evidence and the fact that T. thiogenes has the hallmark physiological characteristics of a Geobacter species, Trichlorobacter thiogenes should be reclassified as a member of the genus Geobacter.

A novel species is proposed for two strains of methanotrophic bacteria (H2T and Sakb1) isolated from an acidic (pH 4.3) Sphagnum peat bog lake (Teufelssee, Germany) and an acidic (pH 4.2) tropical forest soil (Thailand), respectively. Cells of strains H2T and Sakb1 were aerobic, Gram-negative, non-motile, straight or curved rods that were covered by large polysaccharide capsules and contained an intracytoplasmic membrane system typical of type II methanotrophs. They possessed both a particulate and a soluble methane monooxygenase and utilized the serine pathway for carbon assimilation. They were moderately acidophilic organisms capable of growth between pH 4.4 and 7.5 (optimum 5.8–6.2). The most unique characteristic of these strains was the phospholipid fatty acid profile. In addition to the signature fatty acid of type II methanotrophs (18 : 1ω8c), the cells also contained large amounts of what was previously considered to be a signature fatty acid of type I methanotrophs, 16 : 1ω8c. The DNA G+C contents of strains H2T and Sakb1 were 61.5 and 62.1 mol%, respectively. The 16S rRNA gene sequences possessed 96–98 % similarity to sequences of other type II methanotrophs in the genera Methylosinus and Methylocystis. 16S rRNA gene sequence and pmoA phylogeny demonstrated that the strains form a novel lineage within the genus Methylocystis. DNA–DNA hybridization values of strain H2T with Methylocystis parvus OBBPT and Methylocystis echinoides IMET 10491T were 18 and 25 %, respectively. Thus, it is proposed that these two strains represent a novel species, Methylocystis heyeri sp. nov. Strain H2T (=DSM 16984T=VKM B-2426T) is the type strain.

A facultative chemoautotrophic bacterium, strain MLHE-1T, was isolated from Mono Lake, an alkaline hypersaline soda lake in California, USA. Cells of strain MLHE-1T were Gram-negative, short motile rods that grew with inorganic electron donors (arsenite, hydrogen, sulfide or thiosulfate) coupled with the reduction of nitrate to nitrite. No aerobic growth was attained with arsenite or sulfide, but hydrogen sustained both aerobic and anaerobic growth. No growth occurred when nitrite or nitrous oxide was substituted for nitrate. Heterotrophic growth was observed under aerobic and anaerobic (nitrate) conditions. Cells of strain MLHE-1T could oxidize but not grow on CO, while CH4 neither supported growth nor was it oxidized. When grown chemoautotrophically, strain MLHE-1T assimilated inorganic carbon via the Calvin–Benson–Bassham reductive pentose phosphate pathway, with the activity of ribulose 1,5-bisphosphate carboxylase (RuBisCO) functioning optimally at 0.1 M NaCl and at pH 7.3. Strain MLHE-1T grew over broad ranges of pH (7.3–10.0; optimum, 9.3), salinity (15–190 g l−1; optimum 30 g l−1) and temperature (13–40 °C; optimum, 30 °C). Phylogenetic analysis of 16S rRNA gene sequences placed strain MLHE-1T in the class Gammaproteobacteria (family Ectothiorhodospiraceae) and most closely related to Alkalispirillum mobile (98.5 %) and Alkalilimnicola halodurans (98.6 %), although none of these three haloalkaliphilic micro-organisms were capable of photoautotrophic growth and only strain MLHE-1T was able to oxidize As(III). On the basis of physiological characteristics and DNA–DNA hybridization data, it is suggested that strain MLHE-1T represents a novel species within the genus Alkalilimnicola for which the name Alkalilimnicola ehrlichii is proposed. The type strain is MLHE-1T (=DSM 17681T=ATCC BAA-1101T). Aspects of the annotated full genome of Alkalilimnicola ehrlichii are discussed in the light of its physiology.

A strictly anaerobic, mesophilic, sulfate-reducing bacterial strain (MSL86T) isolated from an estuarine sediment in the Sea of Japan (around the Japanese islands) was characterized phenotypically and phylogenetically. The cells were found to be Gram-negative, motile, non-spore-forming rods. Catalase was not detected. The optimum NaCl concentration for growth was 1.0 % (w/v) and the optimum temperature was 35 °C. Strain MSL86T was slightly alkaliphilic, with optimum growth at pH 7.5–7.6. Organic electron donors were incompletely oxidized to (mainly) acetate. Strain MSL86T utilized formate, pyruvate, lactate, fumarate, ethanol, propanol, butanol and glycerol as electron donors for sulfate reduction and did not use acetate, propionate, butyrate, succinate, malate, methanol, glycine, alanine, serine, aspartate, glutamate or H2. Sulfite, thiosulfate and fumarate were used as electron acceptors with lactate as an electron donor. Without electron acceptors, the strain fermented pyruvate and fumarate. The genomic DNA G+C content was 54.4 mol%. Menaquinone MK-8(H4) was the major respiratory quinone. The major cellular fatty acids were C16 : 0, C16 : 1 ω7, C16 : 1 ω5 and C17 : 1 ω6. A phylogenetic analysis based on the 16S rRNA gene sequence placed the strain in the class Deltaproteobacteria. The recognized bacterium most closely related to strain MSL86T was [Desulfobacterium] catecholicum DSM 3882T (sequence similarity 94.4 %), and the next most closely related recognized species were Desulfotalea psychrophila (94.2 % sequence similarity with the type strain) and Desulfotalea arctica (93.7 %). As the physiological and chemotaxonomic characteristics of MSL86T were distinctly different from those of any related species, a novel genus and species Desulfopila aestuarii gen. nov., sp. nov. are proposed to accommodate the strain. The type strain of Desulfopila aestuarii is MSL86T (=JCM 14042T=DSM 18488T).

A phenanthrene- and citronellol-degrading bacterium, strain RLD-1T, was isolated from the fly ash dumping site of a thermal power plant in Delhi, India. The 16S rRNA gene sequence indicated that this strain belongs to the genus Pseudomonas; high levels of sequence similarity were found with respect to Pseudomonas citronellolis DSM 50332T (98.9 %), Pseudomonas jinjuensis DSM 16612T (97.6 %) and Pseudomonas nitroreducens DSM 14399T (97.5 %). Phylogenetic analysis based on 16S rRNA gene sequences placed the strain within the clade represented by these three strains. Strain RLD-1T showed low levels of DNA–DNA hybridization with respect to P. citronellolis DSM 50332T (36 %), P. jinjuensis DSM 16612T (4 %) and P. nitroreducens (13.7 %). Strain RLD-1T can also be distinguished from these three strains on the basis of several biochemical and physiological attributes. The novel strain contained high levels of cellular fatty acids 18 : 1ω7c, 16 : 0 and 16 : 1ω7c, along with 10 : 0 3-OH and 12 : 0 3-OH. Thus, strain RLD-1T represents a novel species of the genus Pseudomonas, for which the name Pseudomonas delhiensis sp. nov. is proposed. The type strain is RLD-1T (=MTCC 7601T=CCM 7361T).