Complete Genome Sequence of Sulfitobacter Phage ϕGT1, Isolated from a Tidal Flat.

The Sulfitobacter bacteria are ubiquitous and important players in organic sulfur cycling in marine environments. Here, we report the complete genome sequence of ϕGT1 infecting Sulfitobacter sp. HGT1, both of which were isolated from coastal sediment. ϕGT1 has a 40,019-bp genome containing 69 predicted protein-encoding genes.

Identification of structural and morphogenesis genes of Pseudoalteromonas phage φRIO-1 and placement within the evolutionary history of Podoviridae.

The virion proteins of Pseudoalteromonas phage φRIO-1 were identified and quantitated by mass spectrometry and gel densitometry. Bioinformatic methods customized to deal with extreme divergence defined a φRIO-1 tail structure homology group of phages, which was further related to T7 tail and internal virion proteins (IVPs). Similarly, homologs of tubular tail components and internal virion proteins were identified in essentially all completely sequenced podoviruses other than those in the subfamily Picovirinae. The podoviruses were subdivided into several tail structure homology groups, in addition to the RIO-1 and T7 groups. Molecular phylogeny indicated that these groups all arose about the same ancient time as the φRIO-1/T7 split. Hence, the T7-like infection mechanism involving the IVPs was an ancestral property of most podoviruses. The IVPs were found to variably host both tail lysozyme domains and domains destined for the cytoplasm, including the N4 virion RNA polymerase embedded within an IVP-D homolog.

Aureimonas glaciistagni sp. nov., isolated from a melt pond on Arctic sea ice.

A Gram-staining-negative, motile, aerobic and rod-shaped bacterial strain, PAMC 27157T, was isolated from a melt pond on sea ice in the Chukchi Sea. Phylogenetic analysis of the 16S rRNA gene sequence of strain PAMC 27157T revealed an affiliation to the genus Aureimonas with the closest sequence similarity (96.2 %) to that of Aureimonas phyllosphaerae. Strain PAMC 27157T grew optimally at 30 °C and pH 7.0 in the presence of 3.5 % (w/v) NaCl. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, phosphatidylmonomethylethanolamine, sulfoquinovosyldiacylglycerol and an unidentified aminolipid. The major cellular fatty acid was summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c, 83.1 %) and the major respiratory quinone was Q-10. The genomic DNA G+C content was 69.1 mol%. The combined phylogenetic, phenotypic and chemotaxonomic data showed that strain PAMC 27157T could be clearly distinguished from species of the genus Aureimonas with validly published names. Thus, strain PAMC 27157T should be classified as representing a novel species in the genus Aureimonas, for which the name Aureimonas glaciistagni sp. nov. is proposed. The type strain is PAMC 27157T ( = KCCM 43049T = JCM 30183T).

Morphology, physiological characteristics, and complete sequence of marine bacteriophage ϕRIO-1 infecting Pseudoalteromonas marina.

Bacteria of the genus Pseudoalteromonas are ubiquitous in the world's oceans. Marine bacteria have been posited to be associated with a major ancient branch of podoviruses related to T7. Yet, although Pseudoalteromonas phages belonging to the Corticoviridae and the Siphoviridae and prophages belonging to the Myoviridae have been reported, no Pseudoalteromonas podovirus was previously known. Here, a new lytic Pseudoalteromonas marina phage, ϕRIO-1, belonging to the Podoviridae was isolated and characterized with respect to morphology, genomic sequence, and biological properties. Its major encoded proteins were distantly similar to those of T7. The most similar previously sequenced viruses were Pseudomonas phage PA11 and Salinivibrio phage CW02. Whereas many elements of the morphology and gene organization of ϕRIO-1 are similar to those of podoviruses broadly related to T7, ϕRIO-1 conspicuously lacked an RNA polymerase gene. Since definitions of a T7 supergroup have included similarity in the DNA polymerase gene, a detailed phylogenetic analysis was conducted, and two major DNA polymerase clades in Autographivirinae and several structural variants of the polA family represented in podoviruses were found. ϕRIO-1 carries an operon similar to that in a few other podoviruses predicted to specify activities related to γ-glutamyl amide linkages and/or unusual peptide bonds. Most growth properties of ϕRIO-1 were typical of T7-like phages, except for a long latent period.

Muricauda olearia sp. nov., isolated from crude-oil-contaminated seawater, and emended description of the genus Muricauda.

A Gram-staining-negative, rod-shaped and non-motile bacterium, designated CL-SS4T, was isolated from crude-oil-contaminated seawater from the west coast of Korea and was investigated by means of a polyphasic taxonomic approach. Strain CL-SS4T grew optimally at 25-30 degrees C, at pH 6.8-7.7 and in the presence of 2-3% sea salts. The major fatty acids were iso-C17:0 3-OH, iso-C15:0 and iso-C15:1 G. The major isoprenoid quinone was MK-6. The DNA G+C content was 50.7 mol%. Analysis of the 16S rRNA gene sequence of strain CL-SS4T revealed that it was a member of the genus Muricauda, sharing 95.7-96.9% sequence similarity with the type strains of Muricauda species and being most closely related to Muricauda aquimarina SW-63T. Phylogenetic analyses based on 16S rRNA gene sequences confirmed that strain CL-SS4T formed a deep lineage related to the genus Muricauda. Strain CL-SS4T was distinguishable from recognized Muricauda species on the basis of differential phenotypic characteristics and DNA G+C content. Based on these results, it is proposed that strain CL-SS4T represents a novel species of the genus Muricauda, for which the name Muricauda olearia sp. nov. is proposed. An emended description of the genus Muricauda is also proposed. The type strain is CL-SS4T (=KCCM 90075T=JCM 15563T).

Marivita cryptomonadis gen. nov., sp. nov. and Marivita litorea sp. nov., of the family Rhodobacteraceae, isolated from marine habitats.

Two strictly aerobic, Gram-negative, rod-shaped bacteria containing photosynthesis-related genes, designated strains CL-SK44(T) and CL-JM1(T), were isolated from a culture of the marine phytoplankton Cryptomonas sp. and coastal seawater from Korea, respectively. Phylogenetic analysis of 16S rRNA gene sequences revealed that the two strains were related to members of the genera Thalassobius (95.3-96.7 % similarity), Pelagibaca (95.3-96.0 %) and Donghicola (95.6 %) in the family Rhodobacteraceae. However, the two novel strains did not form a robust clade with any species of the Roseobacter clade, forming a distinct clade. The major polar lipids of the strains were phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol, an unidentified aminolipid and an unidentified lipid, profiles that were distinguishable from those of the related genera examined. Although the level of 16S rRNA gene sequence similarity between strains CL-SK44(T) and CL-JM1(T) was very high (99.1 %), DNA-DNA relatedness between the strains was 13 %, suggesting that they represent genomically distinct species. In addition, the two strains could be differentiated based on the presence of a minor polar lipid, on the hydrolysis of gelatin and the utilization of carbon sources. Based on the data from the present study, strains CL-SK44(T) and CL-JM1(T) are considered to represent separate novel species of a new genus of the family Rhodobacteraceae, for which the names Marivita cryptomonadis gen. nov., sp. nov. (type species) and Marivita litorea sp. nov. are proposed. The type strains of Marivita cryptomonadis and Marivita litorea are CL-SK44(T) (=KCCM 90070(T)=JCM 15447(T)) and CL-JM1(T) (=KCCM 90071(T)=JCM 15446(T)), respectively.

Maritalea myrionectae gen. nov., sp. nov., isolated from a culture of the marine ciliate Myrionecta rubra.

A Gram-negative, rod-shaped, strictly aerobic bacterium, designated strain CL-SK30(T), was isolated from a culture of the marine ciliate Myrionecta rubra. 16S rRNA gene sequence analysis revealed that strain CL-SK30(T) was most closely related to Cucumibacter marinus (92.0 % similarity) and next to the type strains of species of the genus Devosia (89.8-91.3 % similarities) in the family Hyphomicrobiaceae. Phylogenetic analyses of the 16S rRNA gene sequences showed that strain CL-SK30(T) formed a robust clade together with C. marinus, but the sequence divergence value of 8 % between them indicated that the novel bacterium represented a distinct lineage. Strain CL-SK30(T) grew optimally in the presence of 2-5 % sea salts at 30-35 degrees C and pH 7.2-8.0. The major polar lipids were phosphatidylglycerol, diphosphatidylglycerol, two unidentified glycolipids, an unidentified phospholipid and an unidentified lipid. Ubiquinone 10 was the major quinone. The DNA G+C content was 52.7 mol%. Based on its phenotypic, chemotaxonomic and phylogenetic characteristics, strain CL-SK30(T) represents a novel genus and species of the family Hyphomicrobiaceae, for which the name Maritalea myrionectae gen. nov., sp. nov. is proposed. The type strain is CL-SK30(T) (=KCCM 90060(T)=DSM 19524(T)).

Cucumibacter marinus gen. nov., sp. nov., a marine bacterium in the family Hyphomicrobiaceae.

A Gram-negative, rod-shaped, strictly aerobic micro-organism, designated strain CL-GR60(T), was isolated from coastal seawater from the East Sea, Korea. A 16S rRNA gene sequence analysis revealed a clear affiliation with the family Hyphomicrobiaceae. Phylogenetic analyses showed that strain CL-GR60(T) formed a robust cluster with the species of the genus Devosia at sequence similarity levels of 91.1-93.1 %; no other species in the family Hyphomicrobiaceae shared more than 90 % sequence similarity with strain CL-GR60(T). The strain grew optimally in the presence of 3-4 % sea salts at 30-35 degrees C and pH 7. The major polar lipids were phosphatidylglycerol, diphosphatidylglycerol, two unidentified glycolipids, an unidentified phospholipid and an unidentified lipid. The strain contained C(18 : 1)omega7c (54.7 %), 11-methyl C(18 : 1)omega7c (19.3 %), C(18 : 0) (14.4 %) as the predominant fatty acids. Ubiquinone-10 was the major quinone. The DNA G+C content was 62.9 mol%. On the basis of physiological data, fatty acid composition and results of phylogenetic analysis of the 16S rRNA gene sequence, strain CL-GR60(T) represents a novel genus and species within the family Hyphomicrobiaceae, for which the name Cucumibacter marinus gen. nov., sp. nov. is proposed. The type strain of Cucumibacter marinus is CL-GR60(T) (=KCCM 90027(T) =DSM 18995(T)).

Thalassobaculum litoreum gen. nov., sp. nov., a member of the family Rhodospirillaceae isolated from coastal seawater.

A Gram-negative, facultatively anaerobic strain with slightly curved and straight rod-shaped cells, strain CL-GR58(T), was isolated from coastal seawater (near Gori, Korea). Analyses of the 16S rRNA gene sequence revealed that strain CL-GR58(T) belonged to the family Rhodospirillaceae with Azospirillum lipoferum as its closest relative (gene sequence similarity of 90.9 %). Phylogenetic analyses of the 16S rRNA gene sequences showed that strain CL-GR58(T) was not associated with any known genera in the family Rhodospirillaceae. The novel strain grew in the presence of 1-10 % sea salts, optimally at 30-35 degrees C and pH 8. The major cellular fatty acids consisted of C(18 : 1)omega7c (48.5 %), C(16 : 0) (14.8 %), C(17 : 0) (12.2 %), C(19 : 0) cyclo omega8c (6.3 %) and summed feature 3 (C(16 : 1)omega7c and/or iso-C(15 : 0) 2-OH, 6.0 %). Among the phylogenetically related genera, the fatty acid C(17 : 0) was found only in strain CL-GR58(T). The DNA G+C content of the novel strain was 68.0 mol%. According to phylogenetic analyses of the 16S rRNA gene sequence, fatty acid content and the physiological data, strain CL-GR58(T) represents a novel species in a new genus of the family Rhodospirillaceae, for which the name Thalassobaculum litoreum gen. nov., sp. nov. is proposed. The type strain of the type species is CL-GR58(T) (=KCCM 42674(T)=DSM 18839(T)).

Flectobacillus lacus sp. nov., isolated from a highly eutrophic pond in Korea.

A Gram-negative, almost straight, rod-shaped, non-motile bacterium, designated CL-GP79(T), was isolated from a highly eutrophic pond located within the campus of Seoul National University, Korea. Phylogenetic analyses based on 16S rRNA gene sequencing showed that strain CL-GP79(T) belongs to the family Flexibacteraceae, with Flectobacillus major as its closest relative (similarity of 95.7 %). The cellular fatty acids consist mainly of C(16 : 1)omega5c (mean +/- sd, 26.9 +/- 10.8 %), iso-C(15 : 0) 2-OH and/or C(16 : 1)omega7c (19.2 +/- 2.3 %) and iso-C(15 : 0) (12.1 +/- 1.3 %). The DNA G + C content was found to be 38.3 mol%. Phenotypic, chemotaxonomic and phylogenetic analyses indicated that strain CL-GP79(T) could be assigned to the genus Flectobacillus, but could be distinguished from F. major. The strain CL-GP79(T) therefore represents a novel species, for which the name Flectobacillus lacus sp. nov. is proposed, with CL-GP79(T) (=KCCM 42271(T)=JCM 13398(T)) as the type strain.