Agarivorans albus gen. nov., sp. nov., a gamma-proteobacterium isolated from marine animals. (17/120)

Six bacterial strains were isolated from healthy marine organisms that were collected from the coast of the Kanto area in Japan. Phylogenetic analysis based on 16S rDNA sequence similarity showed that the six isolates formed a separate cluster in the gamma-Proteobacteria and were related to the genera Alteromonas and Glaciecola (<91.6 % similarity). The isolates were related closely to each other (DNA-DNA reassociation values of 74-93 %). The isolates had a polar flagellum and were Gram-negative, mesophilic, strictly aerobic rods that required salt for growth. Distinct phenotypic features of this group included the ability to hydrolyse agar and white pigmentation of colonies. The DNA G+C content of the isolates was 48-50 mol%. The major quinone was Q-8. Phenotypic characteristics of the isolates differed from those of members of the genera Alteromonas and GLACIECOLA: The name Agarivorans albus gen. nov., sp. nov. is proposed for the six isolates; the type strain is MKT 106(T) (=IAM 14998(T)=LMG 21761(T)).  (+info)

Enzymatic properties and nucleotide and amino acid sequences of a thermostable beta-agarase from the novel marine isolate, JAMB-A94. (18/120)

A gene, agaA, for a novel beta-agarase from the marine bacterium JAMB-A94 was cloned and sequenced. The 16S rDNA of the isolate had the closest match, of only 94.8% homology, with that from Microbulbifer salipaludis JCM11542(T). The agaA gene encoded a protein with a calculated molecular mass of 48,203 Da. The deduced amino acid sequence showed 37-66% identity to those of known agarases in glycoside hydrolase family 16. A carbohydrate-binding module-like amino acid sequence was found in the C-terminal region. The recombinant enzyme was hyper-produced extracellularly when Bacillus subtilis was used as a host. The purified enzyme was an endo-type beta-agarase, yielding neoagarotetraose as the main final product. It was very thermostable up to 60 degrees C. The optimal pH and temperature for activity were around 7.0 and 55 degrees C respectively. The activity was not inhibited by EDTA (up to 100 mM) and sodium dodecyl sulfate (up to 30 mM).  (+info)

Microbulbifer maritimus sp. nov., isolated from an intertidal sediment from the Yellow Sea, Korea. (19/120)

A Gram-negative, rod-shaped, non-spore-forming, slightly halophilic bacterium (strain TF-17T) was isolated from an intertidal sediment from the Yellow Sea, Korea. Pigment of strain TF-17T was similar to that of Microbulbifer elongatus, but different from those of Microbulbifer hydrolyticus and Microbulbifer salipaludis. Strain TF-17T was distinguishable from M. elongatus by some phenotypic properties, including motility, optimal growth temperature and others. Phylogenetic analysis based on 16S rDNA sequences showed that strain TF-17TT clustered with the type strains of the three Microbulbifer species with validly published names. Strain TF-17T exhibited 16S rDNA sequence similarity levels of 95.1-95.7% to the type strains of the three Microbulbifer species. The predominant respiratory lipoquinone found in strain TF-17T was ubiquinone-8. The major fatty acid was iso-C(15 : 0) and significant amounts of iso-C(11 : 0) 3-OH and iso-C(17 : 1)omega9c were also present. The DNA G+C content of strain TF-17T was 59.9 mol%. Levels of DNA-DNA relatedness between strain TF-17T and the type strains of the three Microbulbifer species were in the range 10.0-13.0%. On the basis of phenotypic and phylogenetic data and genotypic distinctiveness, strain TF-17T (=KCCM 41774T=JCM 12187T) is proposed as the type strain of a novel species of the genus Microbulbifer, Microbulbifer maritimus sp. nov.  (+info)

Glaciecola polaris sp. nov., a novel budding and prosthecate bacterium from the Arctic Ocean, and emended description of the genus Glaciecola. (20/120)

Four strains of cold-adapted, strictly aerobic and facultative oligotrophic bacteria were isolated from polar seas and investigated using a polyphasic taxonomic approach. Two strains (LMG 21857T and LMG 21854) derive from Arctic sea water whereas the other two strains (LMG 21855 and LMG 21858) were isolated from Antarctic sea water. Phylogenetic analysis based on 16S rRNA gene sequences indicated that these strains belong to the gamma-subclass of the Proteobacteria and are related to the genus Glaciecola, with 98.0-99.7 % sequence similarity to Glaciecola mesophila and 94.2-95.3 % sequence similarity to Glaciecola punicea, their nearest phylogenetic neighbours. Two strains (LMG 21855 and LMG 21858) were identified as G. mesophila, whereas DNA-DNA hybridization results and differences in phenotypic characteristics showed that the other two strains (LMG 21857T and LMG 21854) constitute a novel species within the genus Glaciecola, with a DNA G + C content of 44.0 mol%. The isolates are Gram-negative, chemoheterotrophic, motile, rod-shaped cells that are psychrotolerant and moderately halophilic. Buds can be produced on mother cells and on prosthecae. Branch formation of prosthecae occurs. Whole-cell fatty acid profiles of the isolates are very similar and include C(16 : 0) and C(16 : 1)omega7c as the major fatty acid components. On the basis of genotypic and phenotypic properties, a novel species of the genus Glaciecola is described, for which the name Glaciecola polaris sp. nov. is proposed, with isolate LMG 21857T (= CIP 108324T = ARK 150T) as the type strain. An emended description of the genus Glaciecola is presented.  (+info)

Marinobacter flavimaris sp. nov. and Marinobacter daepoensis sp. nov., slightly halophilic organisms isolated from sea water of the Yellow Sea in Korea. (21/120)

Two Gram-negative, motile, non-spore-forming and slightly halophilic rods (strains SW-145T and SW-156T) were isolated from sea water of the Yellow Sea in Korea. Strains SW-145T and SW-156T grew optimally at 37 and 30-37 degrees C, respectively, and in the presence of 2-6 % (w/v) NaCl. Strains SW-145T and SW-156T were chemotaxonomically characterized as having ubiquinone-9 as the predominant respiratory lipoquinone and C(16 : 0), C(18 : 1)omega9c, C(16 : 1)omega9c and C(12 : 0) 3-OH as the major fatty acids. The DNA G + C contents of strains SW-145T and SW-156T were 58 and 57 mol%, respectively. Phylogenetic analyses based on 16S rRNA gene sequences showed that strains SW-145T and SW-156T fell within the evolutionary radiation enclosed by the genus Marinobacter. The 16S rRNA gene sequences of strains SW-145T and SW-156T were 94.8 % similar. Strains SW-145T and SW-156T exhibited 16S rRNA gene sequence similarity levels of 94.3-98.1 and 95.4-97.7 %, respectively, with respect to the type strains of all Marinobacter species. Levels of DNA-DNA relatedness, together with 16S rRNA gene sequence similarity values, indicated that strains SW-145T and SW-156T are members of two species that are distinct from seven Marinobacter species with validly published names. On the basis of phenotypic properties and phylogenetic and genotypic distinctiveness, strains SW-145T (= KCTC 12185T = DSM 16070T) and SW-156T (= KCTC 12184T = DSM 16072T) should be placed in the genus Marinobacter as the type strains of two distinct novel species, for which the names Marinobacter flavimaris sp. nov. and Marinobacter daepoensis sp. nov. are proposed.  (+info)

Amino acid residues involved in cold adaptation of isocitrate lyase from a psychrophilic bacterium, Colwellia maris. (22/120)

To investigate the mechanism of cold adaptation of isocitrate lyase (ICL; EC 4.1.3.1) from the psychrophilic bacterium Colwellia maris, Gln207 and Gln217 of this enzyme were substituted by His and Lys, respectively, by site-directed mutagenesis. His184 and Lys194 of ICL from Escherichia coli, corresponding to the two Gln residues of C. maris ICL, are highly conserved in the ICLs of many organisms and are known to be essential for catalytic function. The mutated ICLs (Cm-Q207H and Cm-Q217K, respectively) and wild-type enzymes of C. maris and E. coli (Cm-WT and Ec-WT) with His-tagged peptides were overexpressed in E. coli cells and purified to homogeneity. Thermolabile Cm-WT and mutated ICLs were susceptible to digestion with trypsin, while relatively thermostable Ec-WT was resistant to trypsin digestion, suggesting that the thermostability and resistance to tryptic digestion of the ICLs are related. Cm-Q207H and Cm-Q217K showed specific activities similar to Cm-WT at temperatures between 30 degrees C and 40 degrees C, but their activities between 10 degrees C and 25 degrees C were decreased, indicating that the two Gln residues of the C. maris ICL play important roles in its cold adaptation. Phylogenetic analysis of ICLs from various organisms revealed that the C. maris ICL can be categorized in a novel group, subfamily 3, together with several eubacterial ICLs.  (+info)

Marinobacter bryozoorum sp. nov. and Marinobacter sediminum sp. nov., novel bacteria from the marine environment. (23/120)

Two marine, Gram-negative, aerobic, halophilic strains, designated KMM 3657T and KMM 3840T, were isolated and found to be phylogenetically closely related to each other, showing 96.6 % 16S rRNA gene sequence similarity. Both strains are members of the genus Marinobacter in the gamma-Proteobacteria (94.7-98.0 % 16S rRNA gene sequence similarity). Strain KMM 3657T and Marinobacter lipolyticus SM19T were closely related, with 98.0 % sequence similarity. The novel strains shared generic physiological and chemotaxonomic properties with Marinobacter species, but differed in their temperature range for growth, inability to grow in 20 % NaCl and at >43 degrees C, metabolic properties and fatty acid composition. On the basis of phenotypic and phylogenetic analysis data, it is proposed that the strains represent two novel species, Marinobacter bryozoorum sp. nov., with the type strain KMM 3840T (=50-11T=DSM 15401T), and Marinobacter sediminum sp. nov., with the type strain KMM 3657T (=R65T=DSM 15400T).  (+info)

Salinimonas chungwhensis gen. nov., sp. nov., a moderately halophilic bacterium from a solar saltern in Korea. (24/120)

A halophilic non-spore-forming bacterium of the gamma-Proteobacteria, designated strain BH030046T, was isolated from a solar saltern in Korea. Cells were Gram-negative, chemoheterotrophic, short rod-shaped and motile with a polar flagellum. Comparative 16S rRNA gene sequence analysis revealed that strain BH030046T formed a distinct lineage in the family Alteromonadaceae and was distinguished from its closest related genera Alteromonas (91.4-94.8 %), Aestuariibacter (92.1-93.5 %) and Glaciecola (92.1-93.5 %) on the basis of low 16S rRNA gene sequence similarities. Physiological and biochemical data also showed that the isolate was different from members of these three genera. The predominant cellular fatty acids were C(16 : 0) and C(18 : 1)omega7c. DNA G+C content was 48 mol% and the major isoprenoid quinone was Q-8. The strain grew optimally at 30-35 degrees C, pH 7.0-8.0 and 2-5 % NaCl. On the basis of physiological and molecular properties, strain BH030046T (=KCTC 12239T=DSM 16280T) represents a novel genus and species in the family Alteromonadaceae, for which the name Salinimonas chungwhensis gen. nov., sp. nov. is proposed.  (+info)