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ABSTRACT: A seawater bacterium, designated IMCC3101(T), was isolated from Antarctic coastal seawater. The strain was Gram-negative, chemoheterotrophic, obligately aerobic, pigmented dark yellow (flexirubin-type pigments) and devoid of gliding and flagellar motility. On the basis of 16S rRNA gene sequence comparisons, the most closely related species was Ulvibacter litoralis (96.6 %). Phylogenetic trees generated by using 16S rRNA gene sequences confirmed that the strain belonged to the genus Ulvibacter in the family Flavobacteriaceae. The DNA G+C content was 37.0 mol% and the major respiratory quinone was MK-6. Several phenotypic characteristics, including cell and colony morphology, the absence of gliding motility and the temperature range for growth, serve to differentiate the strain from the only species in the genus Ulvibacter with a validly published name (U. litoralis). Therefore, strain IMCC3101(T) represents a novel species of the genus Ulvibacter, for which the name Ulvibacter antarcticus sp. nov. is proposed. The type strain is IMCC3101(T) (=KCCM 42686(T)=NBRC 102682(T)).
International journal of systematic and evolutionary microbiology 01/2008; 57(Pt 12):2922-5. · 2.27 Impact Factor
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ABSTRACT: A seawater bacterium, designated IMCC3195T, was isolated from the Antarctic coast. Cells of the novel strain were Gram-negative, rusty-coloured, strictly aerobic, chemoheterotrophic, non-budding and non-motile rods or vibrioids that possessed a thin prostheca. Based on 16S rRNA gene sequence comparisons, the novel strain was most closely related to the genera Hyphomonas (89.4-90.9%), Maricaulis (90.1-90.4%), Hirschia (89.0%) and Oceanicaulis (87.9%) of the family Hyphomonadaceae. Phylogenetic analyses also showed the Antarctic isolate to be only distantly related to the genera of stalked bacteria of marine origin in the family Hyphomonadaceae. The DNA G+C content of the novel strain was 60.3 mol% and the predominant cellular fatty acids were C18:1omega7c (41.9%), C17:1omega8c (21.4%) and C17:0 (14.3%). The major quinone was Q-10. Several phenotypic and chemotaxonomic characteristics, including optimum temperature and salinity range for growth, cell morphology, pigmentation and fatty acid content, differentiated the novel strain from other related genera in the family Hyphomonadaceae. From the taxonomic evidence collected in this study, it is suggested that strain IMCC3195T (=KCCM 42687T=NBRC 103098T) represents a new genus and novel species in the family Hyphomonadaceae, for which the name Robiginitomaculum antarcticum gen. nov., sp. nov. is proposed.
International journal of systematic and evolutionary microbiology 12/2007; 57(Pt 11):2595-9. · 2.27 Impact Factor
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ABSTRACT: A freshwater bacterium, designated IMCC1728(T), was isolated from a eutrophic pond. The strain was Gram-negative, chemoheterotrophic and facultatively aerobic, forming non-motile rods that contained poly-beta-hydroxybutyrate granules. Based on 16S rRNA gene sequence comparisons, the most closely related species to strain IMCC1728(T) was Methylibium petroleiphilum (97.0 % similarity). Phylogenetic trees generated using 16S rRNA gene sequences showed that this isolate formed an independent phyletic line of the genus Methylibium clade of the class Betaproteobacteria. The DNA G+C content of the strain was 66.2+/-0.4 mol%. The predominant cellular fatty acid constituents were C(16 : 1)omega7c and/or iso-C(15 : 0) 2-OH (43.1 %), C(16 : 0) (20.3 %), C(12 : 0) (13.4 %) and C(10 : 0) 3-OH (7.3 %). The strain contained Q-8 as the predominant ubiquinone. Several phenotypic characteristics, including flagellation, temperature range for growth and carbon source utilization patterns, differentiated strain IMCC1728(T) from species of the genus Methylibium. Therefore, it is proposed that strain IMCC1728(T) represents a novel species, Methylibium aquaticum sp. nov. The type strain is IMCC1728(T) (=KCCM 42364(T)=NBRC 102349(T)).
International journal of systematic and evolutionary microbiology 10/2007; 57(Pt 9):2125-8. · 2.27 Impact Factor
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ABSTRACT: A Gram-negative, yellow-coloured, non-motile, chemoheterotrophic, strictly aerobic, rod-shaped bacterium, designated IMCC1616(T), was isolated from the marine polychaete Periserrula leucophryna inhabiting tidal flat sediment of the Yellow Sea, and characterized by a polyphasic approach. The temperature, pH and NaCl ranges for growth were 3-37 degrees C, pH 5.0-11.0 and 0.5-7.5 %. Based on 16S rRNA gene sequence similarity analyses, the strain was most closely related to members of the genera Lutibacter (90.7 %), Tenacibaculum (89.2-90.4 %) and Polaribacter (88.4-90.2 %). Phylogenetic analysis using three treeing algorithms based on 16S rRNA gene sequences indicated that the strain formed a distinct lineage within the family Flavobacteriaceae. The DNA G+C content of the strain was 40.1 mol% and the predominant cellular fatty acids were iso-C(15 : 0) (16.5 %), anteiso-C(15 : 0) (10.9 %), iso-C(17 : 0) 3-OH (8.8 %) and iso-C(17 : 1) omega 9c (8.2 %). The DNA G+C content, large amount of iso-C(17 : 1) omega 9c and several phenotypic characteristics, including growth temperature and catalase activity, differentiated the strain from other related genera in the family. Therefore, from the taxonomic evidence collected in this study, it is proposed that strain IMCC1616(T) represents a new genus and species named Lutimonas vermicola gen. nov., sp. nov. The type strain of Lutimonas vermicola is strain IMCC1616(T) (=KCCM 42379(T) =NBRC 102041(T)).
International journal of systematic and evolutionary microbiology 09/2007; 57(Pt 8):1679-84. · 2.27 Impact Factor
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ABSTRACT: Four Gram-negative, chemoheterotrophic, nonmotile, yellow-colored strains were isolated from the East Sea or from deep-sea sediments of Nankai Trough by standard dilution plating. Characterization by polyphasic approaches indicated that the four strains are members of the same species. Phylogenetic analyses based on 16S rRNA gene sequences revealed that the strains formed a coherent and novel genus-level lineage within the family Flavobacteriaceae. The dominant cellular fatty acids were i-C15:0, 3-OH i-C17:0, and 2-OH i-C15:0 and/or C16:1 omega7c. Predominance of 2-OH i-C 15:0 and/or C16:1omega7c clearly differentiated the strains from closely related members. The DNA G+C contents ranged 35.1-36.2 mol%. It is proposed, from the polyphasic evidence, that the strains should be placed into a novel genus and species named Sufflavibacter maritimus gen. nov., sp. nov., with strain IMCC 1001T (=KCCM 42359T=NBRC 102039T) as the type strain.
Journal of Microbiology and Biotechnology 09/2007; 17(8):1379-84. · 1.38 Impact Factor
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ABSTRACT: Previously, we reported that ten strains belonging to Erythrobacter showed epoxide hydrolase (EHase) activities toward various epoxide substrates. Three genes encoding putative EHases were identified by analyzing open reading frames of Erythrobacter litoralis HTCC2594. Despite low similarities to reported EHases, the phylogenetic analysis of the three genes showed that eeh1 was similar to microsomal EHase, while eeh2 and eeh3 could be grouped with soluble EHases. The three EHase genes were cloned, and the recombinant proteins (rEEH1, rEEH2, and rEEH3) were purified. The functionality of purified proteins was proved by hydrolytic activities toward styrene oxide. EEH1 preferentially hydrolyzed (R)-styrene oxide, whereas EEH3 preferred to hydrolyze (S)-styrene oxide, representing enantioselective hydrolysis of styrene oxide. On the other hand, EEH2 could hydrolyze (R)- and (S)-styrene oxide at an equal rate. The optimal pH and temperature for the EHases occurred largely at neutral pHs and 40-55 degrees C. The substrate selectivity of rEEH1, rEEH2, and rEEH3 toward various epoxide substrates were also investigated. This is the first representation that a strict marine microorganism possessed three EHases with different enantioselectivity toward styrene oxide.
Applied Microbiology and Biotechnology 09/2007; 76(2):365-75. · 3.42 Impact Factor
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ABSTRACT: Gram-negative, facultatively aerobic, chemoheterotrophic, short rod-shaped marine bacterial strains HTCC2662(T) and HTCC2663, isolated from the Sargasso Sea by using a dilution-to-extinction culturing method, were investigated to determine their taxonomic position. Characterization of the two strains by phenotypic and phylogenetic analyses revealed that they belonged to the same species. The DNA G+C content of strain HTCC2662(T) was 58.4 mol% and the predominant cellular fatty acids were C(18 : 1) omega 7c (52.5 %), C(16 : 0) 2-OH (13.5 %) and C(18 : 1) 11-methyl omega 7c (12.2 %). Phylogenetic analysis of the 16S rRNA gene sequences showed that the strains represented a distinct line of descent within the genus Ruegeria, with highest sequence similarities to Ruegeria atlantica DSM 5823(T) (97.2 %), Ruegeria lacuscaerulensis DSM 11314(T) (96.5 %) and Ruegeria pomeroyi DSM 15171(T) (95.6 %). Several phenotypic characteristics, including facultatively requiring NaCl and oxygen for growth, together with the cellular fatty acid composition, differentiated strain HTCC2662(T) from other members of the genus Ruegeria. Based on phenotypic, chemotaxonomic and phylogenetic traits, it is suggested that strains HTCC2662(T) and HTCC2663 represent a novel species of the genus Ruegeria, for which the name Ruegeria pelagia sp. nov. is proposed. The type strain is HTCC2662(T) (=KCCM 42378(T)=NBRC 102038(T)).
International journal of systematic and evolutionary microbiology 09/2007; 57(Pt 8):1815-8. · 2.27 Impact Factor
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ABSTRACT: A Gram-negative, motile by tuft flagella, obligately aerobic chemoorganoheterotrophic, sphere-form bacterium, designated IMCC3135(T), was isolated from the Antarctic surface seawater of King George Island, West Antarctica. The strain was mesophilic, neutrophilic, and requiring NaCl for growth, but neither halophilic nor halotolerant. The 16S rRNA gene sequence analysis indicated that the strain was most closely related to genera of the order Chromatiales in the class Gammaproteobacteria. The most closely related genera showed less than 90% 16S rRNA gene sequence similarity and included Thioalkalispira (89.9%), Thioalkalivibrio (88.0%-89.5%), Ectothiorhodospira (87.9%-89.3%), Chromatium (88.3%-88.9%), and Lamprocystis (87.7%-88.9%), which represent three different families of the order Chromatiales. Phylogenetic analyses showed that this Antarctic strain represented a distinct phylogenetic lineage in the order Chromatiales and could not be assigned to any of the defined families in the order. Phenotypic characteristics, including primarily non-phototrophic, non-alkaliphilic, non-halophilic, and obligately aerobic chemoheterotrophic properties, differentiated the strain from other related genera. The very low sequence similarities (<90%) and distant relationships between the strain and members of the order suggested that the strain merited classification as a novel genus within a novel family in the order Chromatiales. On the basis of these taxonomic traits, a novel genus and species is proposed, Granulosicoccus antarcticus gen. nov., sp. nov., in a new family Granulosicoccaceae fam. nov. Strain IMCC3135(T) (=KCCM 42676(T)=NBRC 102684(T)) is the type strain of Granulosicoccus antarcticus.
Journal of Microbiology and Biotechnology 09/2007; 17(9):1483-90. · 1.38 Impact Factor
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ABSTRACT: A short-rod-shaped, Gram-negative, non-motile bacterial strain, designated AZO-C(T), was isolated from a sample of seawater collected from the Eluanbi coast of Pingtung County in southern Taiwan and was characterized by using a polyphasic approach. Phylogenetic analyses based on 16S rRNA gene sequences showed that the strain formed a monophyletic branch at the periphery of the evolutionary radiation occupied by the genus Oceanicola in the order Rhodobacterales of the Alphaproteobacteria. The closest neighbours were Oceanicola batsensis HTCC2597(T) (95.6 % similarity), Oceanicola nanhaiensis SS011B1-20(T) (94.5 %) and Oceanicola granulosus HTCC2516(T) (94.0 %). The predominant fatty acid was 18 : 1 omega 7c (49.1 %), and significant amounts of 19 : 0 cyclo (24.6 %) and 16 : 0 (14.7 %) were present. The DNA-DNA relatedness of the strain with respect to recognized species of the genus Oceanicola was less than 70 %. The isolate was also distinguishable from members of the genus Oceanicola on the basis of phenotypic and biochemical characteristics. It is evident from the genotypic, chemotaxonomic and phenotypic data, therefore, that strain AZO-C(T) represents a novel species of the genus Oceanicola, for which the name Oceanicola marinus sp. nov. is proposed. The type strain is AZO-C(T) (=LMG 23705(T)=BCRC 17591(T)).
International journal of systematic and evolutionary microbiology 08/2007; 57(Pt 7):1625-9. · 2.27 Impact Factor
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ABSTRACT: A Gram-negative, non-motile, chemoheterotrophic, facultatively aerobic, short-rod-shaped bacterium, designated IMCC1097(T), was isolated from coastal seawater (10 m depth) of the East Sea, Korea. The temperature, pH and NaCl ranges for growth were 15-30 degrees C, pH 5.0-10.0 and 1.5-10 % NaCl. The colonies of the strain were very small, having a mean diameter of 0.05 mm. 16S rRNA gene sequence data indicated that the strain was most closely related to genera within the class Gammaproteobacteria. Members of the most closely related genera showed less than 90 % sequence similarity and included Saccharospirillum (89.3 %), Oleiphilus (88.7 %), Reinekea (88.2 %), Alcanivorax (86.4-87.6 %) and Zooshikella (87.6 %), which represent five different families of the order Oceanospirillales. Phylogenetic analyses showed that this marine strain represented a distinct phylogenetic lineage in the order Oceanospirillales and could not be assigned to any of the defined families in the order. The predominant fatty acids were C(16 : 1) omega 7c and/or iso-C(15 : 0) 2-OH, C(18 : 1) omega 7c and C(10 : 0) 3-OH, and the DNA G+C content was 57.9 mol%. These chemotaxonomic properties, together with phenotypic characteristics, served to differentiate the strain from phylogenetically closely related genera. The very low sequence similarities (<90 %) and distant relationships between IMCC1097(T) and members of the order Oceanospirillales suggested that the strain merited classification within a novel genus within a novel family in the order. On the basis of taxonomic evidence collected in this study, a novel genus and species are proposed, Litoricola lipolytica gen. nov., sp. nov., within a new family Litoricolaceae fam. nov. Strain IMCC1097(T) (=KCCM 42360(T) =NBRC 102074(T)) is the type strain of Litoricola lipolytica.
International journal of systematic and evolutionary microbiology 08/2007; 57(Pt 8):1793-8. · 2.27 Impact Factor
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ABSTRACT: A Gram-negative, chemoheterotrophic, strictly aerobic, alkaliphilic, rod-shaped marine bacterium, designated HTCC2654(T), was isolated from the western Sargasso Sea by using a dilution-to-extinction culturing method. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain HTCC2654(T) belonged to the Roseobacter clade of the order Rhodobacterales. The 16S rRNA gene sequence similarity of the strain with respect to other members of the Roseobacter clade ranged from 90.4 to 95.1 %. In the phylogenetic analyses, the strain formed an independent phyletic line and could not be assigned to any other known genera of the Rhodobacterales. The DNA G+C content of strain HTCC2654(T) was 61.7 mol% by HPLC and 64.1 mol% from genome sequences. The predominant constituents of the cellular fatty acids were C(16 : 0) 2-OH (27.3 %), 11-methyl C(18 : 1) omega 7c (19.6 %) and C(18 : 1) omega 7c (17.3 %), and the major polar lipids were phosphatidylethanolamine, phosphatidylglycerol and phosphatidylcholine, which served to differentiate the strain from other members of the Roseobacter clade. On the basis of the taxonomic data obtained in this study, strain HTCC2654(T) represents a novel genus and species, for which the name Maritimibacter alkaliphilus gen. nov., sp. nov. is proposed. The type strain is HTCC2654(T) (=KCCM 42376(T)=NBRC 102057(T)).
International journal of systematic and evolutionary microbiology 08/2007; 57(Pt 7):1653-8. · 2.27 Impact Factor
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ABSTRACT: A bacterial strain named IMCC1877(T) was obtained from surface seawater collected near the coast of Deokjeok island (Yellow Sea), using a standard dilution-plating method. The strain was Gram-negative, chemoheterotrophic and facultatively anaerobic, requiring NaCl, and cells were motile rods with a single polar flagellum. Colonies on marine agar were very small (average diameter 0.1 mm). Based on 16S rRNA gene sequences, the most closely related species to strain IMCC1877(T) was Marinobacterium stanieri (93.7 % sequence similarity to the type strain). Phylogenetic analyses based on 16S rRNA gene sequences showed that this marine isolate belonged to the order Oceanospirillales and formed an independent phyletic line within the clade forming the genus Marinobacterium. The DNA G+C content of the strain was 60.7 mol% and the predominant constituents of the cellular fatty acids were C(18 : 1) omega 7c (36.6 %), C(16 : 1) omega 7c and/or iso-C(15 : 0) 2-OH (26.7 %) and C(16 : 0) (24.3 %). Based on the taxonomic data, only a distant relationship could be established between strain IMCC1877(T) and other Marinobacterium species; the strain therefore represents a novel species of the genus Marinobacterium, for which the name Marinobacterium litorale sp. nov. is proposed. The type strain is IMCC1877(T) (=KCTC 12756(T)=LMG 23872(T)).
International journal of systematic and evolutionary microbiology 08/2007; 57(Pt 7):1659-62. · 2.27 Impact Factor
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ABSTRACT: Ecological studies indicate that aerobic anoxygenic phototrophic bacteria (AAP) that use bacteriochlorophyll to support phototrophic electron transport are widely distributed in the oceans. All cultivated marine AAP are alpha-3 and alpha-4 Proteobacteria, but metagenomic evidence indicates that uncultured AAP Gammaproteobacteria are important members of ocean surface microbial communities. Here we report the description of obligately oligotrophic, marine Gammaproteobacteria that have genes for aerobic anoxygenic photosynthesis. Three strains belonging to the OM60 clade were isolated in autoclaved seawater media. Polymerase chain reaction assays for the pufM gene show that these strains contain photosynthetic reaction centre genes. DNA sequencing and phylogenetic analysis indicate that the pufM genes are polyphyletic, suggesting multiple instances of lateral gene transfer. Peptide sequences from six photosynthesis genes (pufL, pufM, pufC, pufB, pufA and puhA) were detected by proteomic analyses of strain HTCC2080 cells grown aerobically in seawater. They closely match predicted peptides from an environmental seawater bacterial artificial chromosome clone of gammaproteobacterial origin, thus identifying the OM60 clade as a significant source of gammaproteobacterial AAP genes in marine systems. The cell yield and rate of growth of HTCC2080 in autoclaved, aerobic seawater increased in the light. These findings identify the OM60 clade as a source of Gammaproteobacteria AAP genes in coastal oceans, and demonstrate that aerobic, anoxygenic photosynthetic metabolism can enhance the productivity of marine oligotrophic bacteria that also grow heterotrophically in darkness.
Environmental Microbiology 07/2007; 9(6):1456-63. · 5.84 Impact Factor
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ABSTRACT: Proteorhodopsin (PR) is a protein that is abundant in marine bacterioplankton. PR is hypothesized to be a light-dependent proton pump, thus creating a proton gradient that can be used for energy production without electron transport. Currently, the only culture that has been reported to possesses PR is the highly abundant alphaproteobacterium "Candidatus Pelagibacter ubique" (SAR11 clade), but surprisingly, its growth in batch culture was not enhanced by light. Here, we present the first cultured gammaproteobacterium that possesses a PR gene. Genome sequencing and analysis of HTCC2207 showed that the PR gene is present as a lone transcriptional unit directly followed by an operon containing genes that are presumably involved in the synthesis of retinal, the chromophore of PR. Half-time decay times of different PR intermediates in native HTCC2207 cells ranged between 2 and 15 ms, and the absorbance maximum of PR was determined to be 528 nm. Proteorhodopsin was identified in three additional strains, using a specific PCR assay on other cultured members of the SAR92 clade. Phylogenetic analyses of the PR genes determined that they form a deeply rooting cluster not closely related to any PR genes recovered so far. Fluorescence in situ hybridization and RNA blots showed that the SAR92 clade reaches up to 10% of the total bacterial population in surface waters close to the Oregon coast and decreases over depth and distance from the shore. Although the growth of HTCC2207 is limited by the amount of available carbon that is present in the medium applied, these cultures do not grow at higher rates nor do they have higher growth yields when incubated under light.
Applied and Environmental Microbiology 05/2007; 73(7):2290-6. · 3.83 Impact Factor
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ABSTRACT: A Gram-negative, chemoheterotrophic, facultatively anaerobic coccus, designated IMCC1545(T), was isolated from the digestive tract of a marine clamworm, Periserrula leucophryna, inhabiting a tidal flat of the Yellow Sea. Cells of strain IMCC1545(T) are non-motile, dividing by binary fission. The predominant fatty acids are anteiso-C(15 : 0) and C(18 : 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 IMCC1545(T) are 'Fucophilus fucoidanolyticus' SI-1234 (86.5 % 16S rRNA gene sequence similarity), Alterococcus agarolyticus ADT3(T) (81.8 %) and Opitutus terrae PB90-1(T) (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 IMCC1545(T) 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 IMCC1545(T)=KCCM 42343(T)=NBRC 101964(T)) 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.
International journal of systematic and evolutionary microbiology 04/2007; 57(Pt 3):532-7. · 2.27 Impact Factor
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ABSTRACT: Two strictly aerobic, Gram-negative bacteria, designated strains CL-SP27T and B5-6T, were isolated from the hypersaline water of a solar saltern in Korea and from the surface water of the Sargasso Sea, respectively. The two strains were rod-shaped, non-motile and grew on marine agar 2216 as beige colonies. Phylogenetic analyses of 16S rRNA gene sequences revealed a clear affiliation of the novel strains to the family Rhodobacteraceae. However, the novel strains were only distantly related to members of the Roseobacter clade, forming a distinct lineage. Although the 16S rRNA gene sequence similarity between strains CL-SP27T and B5-6T was very high (99.6 %), DNA-DNA relatedness between the strains was 48.4 %, suggesting that the strains be categorized as two genospecies. Additionally, the two novel strains could be differentiated by DNA G+C contents, fatty acid profiles, carbon source utilization patterns, antibiotic susceptibilities and biochemical characteristics. Based on taxonomic data obtained in this study, strains CL-SP27T and B5-6T represent separate species within a novel genus of the family Rhodobacteraceae, for which the names Maribius salinus gen. nov., sp. nov. (type species) and Maribius pelagius sp. nov. are proposed. The type strains of Maribius salinus and Maribius pelagius are CL-SP27T (=KCCM 42113T=JCM 13037T) and B5-6T (=KCCM 42336T=JCM 14009T), respectively.
International journal of systematic and evolutionary microbiology 03/2007; 57(Pt 2):270-5. · 2.27 Impact Factor
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ABSTRACT: We report here on the cultivation of numerous novel bacterial species from a eutrophic freshwater pond. A total of 60 strains, 15 strains per each culture medium, were obtained from the surface of a eutrophic freshwater pond by employing a conventional dilution-plating method with four different kinds of culture media, including R2A, 1/10R2A, PCA, and 1/10PCA. Among the 60 strains isolated, 27 strains showed less than 97% 16S rRNA gene sequence similarities to validly published species, and thus they are considered to comprise 19 novel species. Of the 27 strains assigned to the novel species, the majority of the strains (20 strains) were affiliated with the Alphaproteobacteria and Betaproteobacteria. The remaining 7 strains were affiliated with the Gammaproteobacteria, Firmicutes, Actinobacteria, and Deinococci. Because we have isolated 19 novel species from a usual freshwater pond using a conventional culturing technique, our results suggest that an unexplored ecosystem, even if it looks like a common ecosystem found elsewhere, harbors diverse unidentified microbes, which will be definitely further characterized.
Journal of Microbiology and Biotechnology 02/2007; 17(1):168-75. · 1.38 Impact Factor
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ABSTRACT: A Gram-negative, chemoheterotrophic, facultatively anaerobic, slightly halophilic, oval-shaped marine bacterium, designated HTCC2601T, was isolated from the western Sargasso Sea by high-throughput culturing involving dilution to extinction. Although the 16S rRNA gene sequence similarity between the isolate and Salipiger mucosus was 96.5 %, phylogenetic analyses using different treeing algorithms clearly indicated that the strain forms a distinct lineage within a clade containing the recently classified genera Salipiger and Palleronia in the order Rhodobacterales of the Alphaproteobacteria. The DNA-DNA relatedness between strain HTCC2601T and S. mucosus was 26.3 %. Strain HTCC2601T utilized a wide range of carbohydrates, including hexose monomers, sugar alcohols, organic acids and amino acids, as sole carbon sources. The DNA G+C content of strain HTCC2601T was 65.4 mol%, and the predominant constituents of the cellular fatty acids were 18 : 1omega7c (79.7 %) and 11-methyl 18 : 1omega7c (7.5 %). The strain differed from members of the closely related genera Salipiger and Palleronia in its morphological, biochemical and ecological characteristics. On the basis of the taxonomic data obtained in this study, a novel genus and species, Pelagibaca bermudensis gen. nov., sp. nov., is proposed; HTCC2601T (=KCTC 12554T = JCM 13377T) is the type strain of Pelagibaca bermudensis.
International journal of systematic and evolutionary microbiology 05/2006; 56(Pt 4):855-9. · 2.27 Impact Factor
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Stephen J Giovannoni,
Lisa Bibbs, Jang-Cheon Cho,
Martha D Stapels,
Russell Desiderio,
Kevin L Vergin,
Michael S Rappé,
Samuel Laney,
Lawrence J Wilhelm,
H James Tripp,
Eric J Mathur,
Douglas F Barofsky
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ABSTRACT: Proteorhodopsins are light-dependent proton pumps that are predicted to have an important role in the ecology of the oceans by supplying energy for microbial metabolism. Proteorhodopsin genes were first discovered through the cloning and sequencing of large genomic DNA fragments from seawater. They were later shown to be widely distributed, phylogenetically diverse, and active in the oceans. Proteorhodopsin genes have not been found in cultured bacteria, and on the basis of environmental sequence data, it has not yet been possible to reconstruct the genomes of uncultured bacterial strains that have proteorhodopsin genes. Although the metabolic effect of proteorhodopsins is uncertain, they are thought to function in cells for which the primary mode of metabolism is the heterotrophic assimilation of dissolved organic carbon. Here we report that SAR11 strain HTCC1062 ('Pelagibacter ubique'), the first cultivated member of the extraordinarily abundant SAR11 clade, expresses a proteorhodopsin gene when cultured in autoclaved seawater and in its natural environment, the ocean. The Pelagibacter proteorhodopsin functions as a light-dependent proton pump. The gene is expressed by cells grown in either diurnal light or in darkness, and there is no difference between the growth rates or cell yields of cultures grown in light or darkness.
Nature 12/2005; 438(7064):82-5. · 36.28 Impact Factor
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ABSTRACT: The objective of this study was to develop a mass spectrometric protocol to search for proteins related to phototrophy in marine bacteria. The genes that produce proteins involved in conversion of light into energy have been detected by cloning-sequencing from some of these bacteria, but it was previously unknown if these proteins were actually expressed. Attaining this study's goal was complicated by the fact that the samples consisted of miniscule cell pellets, which yielded small amounts of very complex mixtures of proteins. Sample preparation and analysis were tailored to optimize the probability of detecting the proteins of interest. It has been reported that using both matrix-assisted laser desorption/ionization (MALDI) and electrospray ionization (ESI) to analyze a mixture of peptides leads to the identification of more peptides that either technique alone. In order to exploit this complementarity between ESI and MALDI for proteomic analysis, samples were analyzed using both ionization techniques. With correct choices in sample preparation and ionization process, biologically relevant proteins can be identified out of small samples containing whole proteomes.
Journal of biomolecular techniques: JBT 10/2004; 15(3):191-8.
