Rheinheimera oceanensis sp. nov., a novel member of the genus Rheinheimera, isolated from the West Pacific Ocean.

Two Gram-stain-negative, aerobic, non-motile and short-rod-shaped bacteria, designated as strains GL-53T and GL-15-2-5, were isolated from the seamount area of the West Pacific Ocean and identified using a polyphasic taxonomic approach. The growth of strains GL-53ᵀ and GL-15-2-5 occurred at pH 5.5-10.0, 4-40 °C (optimum at 28 °C) and 0-10.0 % NaCl concentrations (optimum at 0-5.0 %). On the basis of 16S rRNA gene sequence analysis, strains GL-53ᵀ and GL-15-2-5 exhibited the highest similarity to Rheinheimera lutimaris YQF-2T (98.4 %), followed by Rheinheimera pacifica KMM 1406T (98.1 %), Rheinheimera nanhaiensis E407-8T (97.4 %), Rheinheimera aestuarii H29T (97.4 %), Rheinheimera hassiensis E48T (97.2 %) and Rheinheimera aquimaris SW-353T (97.2 %). Phylogenetic analysis revealed that the isolates were affiliated with the genus Rheinheimera and represented an independent lineage. The major fatty acids were summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c), C16 : 0 and summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c). The sole isoprenoid quinone was ubiquinone 8. The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol, one unidentified aminophospholipid (and one unidentified glycolipid. The DNA G+C content was 48.5 mol%. The average nucleotide identity, average amino acid identity and in silico DNA-DNA hybridization values among the genomes of strain GL-53ᵀ and the related strains in the genus Rheinheimera were 75.5-90.1 %, 67.5-93.9 % and 21.4-41.4 %, respectively. Based on their phenotypic, chemotaxonomic and genotypic properties, the two strains were identified as representing a novel species of the genus Rheinheimera, for which the name Rheinheimera oceanensis sp. nov. is proposed. The type strain is GL-53T (=KCTC 82651T=MCCC M20598T).

Metagenomic Features Characterized with Microbial Iron Oxidoreduction and Mineral Interaction in Southwest Indian Ridge.

The Southwest Indian Ridge (SWIR) is one of the typical representatives of deep-sea ultraslow-spreading ridges, and has increasingly become a hot spot of studying subsurface geological activities and deep-sea mining management. However, the understanding of microbial activities is still limited on active hydrothermal vent chimneys in SWIR. In this study, samples from an active black smoker and a diffuse vent located in the Longqi hydrothermal region were collected for deep metagenomic sequencing, which yielded approximately 290 GB clean data and 295 mid-to-high-quality metagenome-assembled genomes (MAGs). Sulfur oxidation conducted by a variety of Gammaproteobacteria, Alphaproteobacteria, and Campylobacterota was presumed to be the major energy source for chemosynthesis in Longqi hydrothermal vents. Diverse iron-related microorganisms were recovered, including iron-oxidizing Zetaproteobacteria, iron-reducing Deferrisoma, and magnetotactic bacterium. Twenty-two bacterial MAGs from 12 uncultured phyla harbored iron oxidase Cyc2 homologs and enzymes for organic carbon degradation, indicated novel chemolithoheterotrophic iron-oxidizing bacteria that affected iron biogeochemistry in hydrothermal vents. Meanwhile, potential interactions between microbial communities and chimney minerals were emphasized as enriched metabolic potential of siderophore transportation, and extracellular electron transfer functioned by multi-heme proteins was discovered. Composition of chimney minerals probably affected microbial iron metabolic potential, as pyrrhotite might provide more available iron for microbial communities. Collectively, this study provides novel insights into microbial activities and potential mineral-microorganism interactions in hydrothermal vents. IMPORTANCE Microbial activities and interactions with minerals and venting fluid in active hydrothermal vents remain unclear in the ultraslow-spreading SWIR (Southwest Indian Ridge). Understanding about how minerals influence microbial metabolism is currently limited given the obstacles in cultivating microorganisms with sulfur or iron oxidoreduction functions. Here, comprehensive descriptions on microbial composition and metabolic profile on 2 hydrothermal vents in SWIR were obtained based on cultivation-free metagenome sequencing. In particular, autotrophic sulfur oxidation supported by minerals was presumed, emphasizing the role of chimney minerals in supporting chemosynthesis. Presence of novel heterotrophic iron-oxidizing bacteria was also indicated, suggesting overlooked biogeochemical pathways directed by microorganisms that connected sulfide mineral dissolution and organic carbon degradation in hydrothermal vents. Our findings offer novel insights into microbial function and biotic interactions on minerals in ultraslow-spreading ridges.

Mesobacterium pallidum gen. nov., sp. nov., Heliomarina baculiformis gen. nov., sp. nov. and Oricola indica sp. nov., three novel Alphaproteobacteria members isolated from deep-sea water in the southwest Indian ridge.

Three Gram-staining-negative, aerobic and rod-shaped strains, designated as T40-1T, T40-3T and JL-62T, were isolated from the deep-sea water in the southwest Indian ridge. For strain T40-1T, growth occurred at 15-37 °C (optimum, 28 °C), pH 6.0-9.0 (optimum, pH 7.5) and in the presence of 0.5-5.0 % NaCl (w/v; optimum, 2.0 %). Strain T40-3T could grow at 15-40 °C (optimum, 28 °C), with 0.5-11.0 % NaCl (optimum, 2.0 %, w/v) at pH 6.0-9.5 (optimum, 8.0). The temperature, pH and salinity ranges for growth of strain JL-62T were 15-40 °C (optimum, 30 °C), pH 5.5-9.0 (optimum, pH 7.5-8.0) and 0.5-9.0 % NaCl (w/v; optimum, 4.0 %). Ubiquinone-10 was the sole ubiquinone in all strains, the major fatty acids (>20 %) were summed feature 8 (C18 : 1 ω7c / C18 : 1 ω6c). The major polar lipids of strains T40-1T and T40-3T were phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine and diphosphatidylglycerol. Strain JL-62T contained phosphatidylmonomethylethanolamine, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and sulfoquinovosyldiacylglycerol as major polar lipids. Phylogenetic trees based on 16S rRNA gene and core-genomic sequences revealed affiliation of strains T40-1Tand T40-3T to the family Roseobacteraceae and formed two independent clades from other Roseobacteraceae genera, and those two strains had average nucleotide identities of 62.0-72.0 % to their phylogenetically related species which fell into to the genus boundary range, indicating that they represent two novel genera. While strain JL-62T represents a novel species in the genus Oricola belonging to the family Phyllobacteriaceae, which was supported by overall genomic relatedness index calculations. The DNA G+C contents of strains T40-1T, T40-3T and JL-62T were 66.5, 60.1 and 62.1 mol %, respectively. Based on the polyphasic taxonomic data, strains T40-1T (=MCCC M24557T=KCTC 82975T) and T40-3T (=MCCC 1K05135T=KCTC 82976T) are classified as representing two novel genera belonging to the family Roseobacteraceae with the names Mesobacterium pallidum gen. nov., sp. nov. and Heliomarina baculiformis gen. nov., sp. nov. are proposed, and strain JL-62T (=MCCC M24579T=KCTC 82974T) is proposed to represent a novel species within the genus Oricola with the name Oricola indica sp. nov. is proposed.

Flavobacterium zhairuonensis sp. nov., a gliding bacterium isolated from marine sediment of the East China Sea.

A yellow pigmented, Gram-stain-negative, aerobic bacterium designated A5.7T was studied to evaluate the taxonomic position following the modern polyphasic approach. The strain was isolated from sediments near Zhairuo Island, which is situated in the East China Sea. Cells were non-spore forming rods without flagella but showed motility by gliding. Growth was observed at 15-35°C (optimum 28°C), pH 6.0-9.0 (optimum pH 6.5) and 0-2% (w/v) NaCl (optimum 0-0.5%) in LB broth. The major respiratory quinone of A5.7T was menaquinone 6. The major polar lipid of A5.7T was phosphatidylethanolamine and the predominant fatty acids (> 5%) were iso-C15:0, iso-C17:0 3-OH, C15:1ω6c, iso-C15:0 3-OH, iso-C15:1 G, summed feature 3 (C16:1ω7c and/or C16:1ω6c) and summed feature 9 (iso-C17:1ω9c and/or C16:010-methyl). Phylogenetic analysis based on 16S rRNA gene sequences showed that the isolate belongs to the genus Flavobacterium and shares the highest sequence similarities with Flavobacterium sharifuzzamanii A7.6T (98.5%), Flavobacterium tistrianum GB 56.1T (98.3%), Flavobacterium nitrogenifigens NXU-44T (97.8%), Flavobacterium anhuiense D3T (97.6%), Flavobacterium ginsenosidimutans THG 01T (97.6%), and Flavobacterium foetidum CJ42T (97.6%). Digital DNA-DNA hybridization and average nucleotide identity values between the strain and its closest phylogenetic neighbors showed the ranges from 19.6 to 34.1% and 73.7 to 87.9%, respectively. Therefore, based on polyphasic characteristics, strain A5.7T represents a novel species of the genus Flavobacterium for which the name Flavobacterium zhairuonensis sp. nov. is proposed. The type strain is A5.7T (= KCTC 62406T = MCCC 1K03494T).

Altererythrobacter aerophilus sp. nov., isolated from deep-sea water of the north-west Pacific.

A Gram-stain-negative, rod-shaped bacterium, designated Ery1T, was isolated from deep-sea seawater collected from the Mariana Trench and subjected to a polyphasic investigation for taxonomy. Strain Ery1T was able to grow in medium containing 0-10 % NaCl (w/v; optimum, 0-1.0 %), pH 5.0-9.5 (optimum, pH 6.0-7.0) and at temperatures between 10-45 °C (optimum, 30-40 °C). The comparison of 16S rRNA gene sequences revealed that strain Ery1T showed highest similarity to Altererythrobacterxinjiangensis S3-63T (97.7 %) and Altererythrobacterrigui WW3T (97.6 %), and exhibited less than 97.5 % sequence similarity to other type strains of the species with validly published names. Phylogenetic analyses indicated that strain Ery1T fell within the cluster comprising the Altererythrobacter species and formed a coherent clade with Altererythrobacterxinjiangensis and Altererythrobactersoli. The OrthoANIu and in silico DNA-DNA hybridization values between strain Ery1T and the reference strains were 73.8-75.9 % and 19.2-20.1 %, respectively. Strain Ery1T contained Q-10 as the major respiratory quinone and Q-11 in a minor amount. The major fatty acids (>10 %) were summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c), summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), C16 : 0, C18 : 1ω7c 11-methyl and C14 : 0 2-OH. The major polar lipids were sphingoglycolipid, diphosphatidylglycerol, phosphatidyglycerol, phatidylethanolamine, phosphatidylcholine and three unidentified glycolipids. Differential phenotypic properties, chemotaxonomic differences, phylogenetic distinctiveness, together with the genomic data demonstrated that strain Ery1T represents a novel species of the genus Altererythrobacter, for which named as Altererythrobacter aerophilus sp. nov. with the type strain Ery1T (=KCTC 62387T=CGMCC 1.16499T=MCCC 1A10037T).

Erythrobacter zhengii sp. nov., a bacterium isolated from deep-sea sediment.

A Gram-stain-negative, strictly aerobic, rod-shaped bacterium, designated V18T, was isolated from a deep-sea sediment sample collected from the Pacific Ocean and subjected to a polyphasic taxonomic investigation. Cells of strain V18T grew in medium containing 0-10.0 % (w/v) NaCl (optimum 1.0 %), at pH 5.5-9.0 (optimum 6.5-7.0) and at 10-40 °C (optimum 30-37 °C). Aesculin and Tweens 20, 40, 60 and 80 were hydrolysed. The isolate contained carotenoid-like pigments and lacked bacteriochlorophyll a. Strain V18T was closely related to members of the genus Erythrobacter, namely Erythrobacter odishensis JA747T (98.9 % 16S rRNA gene sequence similarity), E. westpacificensis JLT2008T (98.8 %), E. gangjinensis K7-2T (97.7 %), E. aquimixticola JSSK-14T (97.6 %), E. marinus KCTC 23554T (97.4 %), E. atlanticus s21-N3T (97.3 %), E. arachoides RC4-10-4T (97.2 %), E. citreus RE35F/1T (97.1 %) and E. luteus KA37T (97.0 %), and exhibited less than 97.0 % sequence similarity with the type strains of other species with validly published names. Phylogenetic analyses revealed that strain V18T clustered with E. odishensis JA747T and formed an independent lineage. The average nucleotide identity and in silico DNA-DNA hybridization values between strain V18T and the type strains of Erythrobacter species were 70.5-83.4 % and 18.4-26.1 %, respectively. Strain V18T contained ubiquinone 10 (Q-10) as the sole respiratory quinone. The major fatty acids (>10 %) were summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c), summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and C16 : 0. The major polar lipids were sphingoglycolipid (SGL), diphosphatidylglycerol (DPG), phosphatidyglycerol (PG), phosphatidylethanolamine (PE) and one unidentified lipid (L1). The DNA G+C content was 62.6 mol%. According to the phenotypic, chemotaxonomic and phylogenetic data, strain V18T represents a novel species of the genus Erythrobacter, for which the name Erythrobacter zhengii is proposed. The type strain is V18T (=KCTC 62389T=MCCC 1K03475T).

Alteromonas alba sp. nov., a marine bacterium isolated from seawater of the West Pacific Ocean.

A Gram-stain-negative, strictly aerobic, motile by one polar flagellum, non-spore-forming, rod-shaped bacterium, designated as 190T, was isolated from seawater of the West Pacific Ocean and subjected to a polyphasic taxonomic investigation. Colonies were 1.0-2.0 mm in diameter, smooth, circular, convex and white after growth on marine agar at 30 °C for 24 h. Strain 190T was found to grow at 4-40 °C (optimum, 30 °C), at pH 5.5-10.5 (optimum, pH 6.5) and with 0.5-12.5 % (w/v) NaCl (optimum, 2.0 %). Chemotaxonomic analysis showed the sole respiratory quinone was ubiquinone 8 (Q-8), and the major fatty acids were summed feature 3 (C16 : 1ω7c and/or iso-C15 : 0 2-OH), C16 : 0 and summed feature 8 (C18 : 1ω6c and/or C18 : 1ω7c). The major polar lipids were phosphatidylethanolamine (PE), phosphatidylglycerol (PG), one unidentified aminolipid (AL1) and two unidentified glycolipids (GL1, GL2). The DNA G+C content of strain 190T was 48.7 mol% based on the genome sequence. The comparison of 16S rRNA gene sequence similarities showed that strain 190T was closely related to Alteromonas oceani S35T (99.6 % sequence similarity), A. lipolytica JW12T (98.2 %), A. aestuariivivens JDTF-113T (97.7 %) and A. mediterranea DET (97.5 %); it exhibited 97.0 % or less sequence similarity with the type strains of other species with validly published names. Phylogenetic trees reconstructed with the neighbour-joining, maximum-parsimony and maximum-likelihood methods based on 16S rRNA gene sequences showed that strain 190T constituted a separate branch with A. oceani, A. confluentis, A. aestuariivivens and A. lipolytica in a clade of the genus Alteromonas. OrthoANI values between strain 190T and A. oceani S35T and A. lipolytica JW12T were 93.5 and 77.9 %, respectively, and in silico DNA-DNA hybridization values were 53.8 and 21.2 %, respectively. Differential phenotypic properties, together with phylogenetic distinctiveness, demonstrated that strain 190T is clearly distinct from recognized species of the genus Alteromonas. On the basis of these features, we propose that strain 190T (=MCCC 1K03456T=KCTC 62227T) represents a novel species of the genus Alteromonas with the name Alteromonas alba sp. nov.

Marinobacter fuscus sp. nov., a marine bacterium of Gammaproteobacteria isolated from surface seawater.

A Gram-stain-negative bacterium, designated NH169-3T, was isolated from a surface seawater sample of the South China Sea and subjected to a taxonomic polyphasic investigation. Strain NH169-3T was strictly aerobic, non-motile, non-spore-forming and rod-shaped. The colony was 1.0-2.0 mm in diameter after the growth on marine agar at 30 °C for 72 h. The centre of the colony was smooth, circular, convex and brown with a transparent periphery. Strain NH169-3T was able to grow at temperatures between 4-40 °C (optimum, 37 °C), pH 5.5-9.0 (pH 7.5) and with 0-12.5 % (w/v) NaCl (3.0 %). Chemotaxonomic analysis showed that the sole respiratory quinone of strain NH169-3T was ubiquinone 9; major fatty acids were C16 : 0 and C18 : 1ω9c, and major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and one unidentified glycolipid. The DNA G+C content was 52.7 mol%. The comparison of 16S rRNA gene sequences showed that strain NH169-3T was closely related to Marinobacter shengliensis SL013A34A2T with a similarity of 98.0 %. Three phylogenetic trees reconstructed with neighbour-joining, maximum-parsimony and maximum-likelihood methods using 16S rRNA gene sequences showed that strain NH169-3T was grouped into a separated branch with M. shengliensis SL013A34A2T in a clade of the genus Marinobacter and closely related to Marinobacter halophilus JCM 30472T, Marinobacter vinifirmus DSM 17747T and Marinobacter hydrocarbonoclasticus DSM 8798T. Analyses of both phenotypic and phylogenetic properties have suggested that strain NH169-3T was distinctive from species with validly published names in genus Marinobacter. Thus, strain NH169-3T (=MCCC 1K03455T=KCTC 62226T) is proposed as a novel species in genus Marinobacter with the name Marinobacter fuscus sp. nov.

Reclassification of Xuhuaishuia manganoxidans Wang et al. 2015 as a later heterotypic synonym of Brevirhabdus pacifica Wu et al. 2015 and emendation of the species description.

A polyphasic taxonomic study was undertaken to clarify the exact position of type strain DY6-4T of Xuhuaishuia manganoxidans. A combination of physiological properties of X. manganoxidans DY6-4T was consistent with those of type strain 22DY15T of Brevirhabdus pacifica. The 16S rRNA gene sequence analyses indicated that X. manganoxidans DY6-4T and B. pacifica 22DY15T shared 100 % similarity and formed a monophyletic group. The close relationship between the two strains was underpinned by the results of chemotaxonomic characteristics, including the fatty acids, quinone and polar lipids. The digital DNA-DNA hybridization and average nucleotide identity values between the two strains were 99.90 and 99.98 %, respectively. Based on these results, we propose that Xuhuaishuia manganoxidans is a later heterotypic synonym of Brevirhabdus pacifica.

Henriciella pelagia sp. nov., isolated from seawater.

Strain LA220T, isolated from seawater of the Eastern Pacific Ocean, was subjected to a polyphasic taxonomic study. Cells of the strain were Gram-stain-negative, aerobic, motile and short rod-shaped. On the basis of 16S rRNA gene sequence analysis, strain LA220T showed high similarity to Henriciella litoralis SD10T (98.5 %), Henriciella marina DSM 19595T (98.3 %) and Henriciellaaquimarina P38T (97.5 %), and exhibited less than 97.0 % 16S rRNA gene sequence similarity with respect to the type strains of other Hyphomonadaceae species. Phylogenetic analyses revealed that strain LA220T fell within the cluster of the genus Henriciella. The average nucleotide identity and in silico DNA-DNA hybridization values between strain LA220T and the type strains of Henriciella species were 74.8-76.8 and 18.4-20.8 %, respectively. The sole respiratory quinone was ubiquinone-10 (Q-10). The principal fatty acids were summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) and C16 : 0. The major polar lipids were three unidentified glycolipids. The DNA G+C content was 59.9 mol%. Phylogenetic distinctiveness, chemotaxonomic differences and phenotypic properties revealed that strain LA220T could be differentiated from recognized Henriciella species. Therefore, strain LA220T is considered to represent a novel species of the genus Henriciella, for which the name Henriciella pelagia sp. nov. (type strain LA220T=CGMCC 1.15928T=KCTC 52577T) is proposed.

Physiological and genomic features of a novel violacein-producing bacterium isolated from surface seawater.

Strains JW1T and JW3, isolated from surface seawater of the Arabian Sea, were subjected to polyphasic taxonomic analysis. Cells of both strains were Gram-stain-negative, aerobic, and rod-shaped. They formed violet pigment and produced violacein. On the basis of 16S rRNA gene sequence analysis, strains JW1T and JW3 showed high 16S rRNA gene sequence similarity with Pseudoalteromonas byunsanensis JCM12483T (98.2%), P. shioyasakiensis SE3T (97.8%), P. arabiensis JCM 17292T (97.3%), and P. gelatinilytica NH153T (97.1%). The 16S rRNA gene sequence similarity between JW1T and JW3 was 100%. Phylogenetic analyses revealed that both strains fell within the cluster of the genus Pseudoalteromonas and represented an independent lineage. The average nucleotide identity and in silico DNA-DNA hybridization values between JW1T and type strains of the closely related Pseudoalteromonas species were 70.9-83.3% and 20.0-26.4%, respectively. The sole respiratory quinone in both strains is ubiquinone 8 (Q-8). The principal fatty acids are summed feature 3 (C16:1ω7c and/or iso-C15:0 2OH), C18:1ω7c, and C16:0. The major polar lipids are phosphatidylethanolamine, phosphatidylglycerol, one unidentified glycolipid, one unidentified aminolipid, and one unidentified phospholipid. The DNA G+C content was 43.3 mol%. Differential phylogenetic distinctiveness, chemotaxonomic differences, and phenotypic properties indicated that strains JW1T and JW3 could be differentiated from the Pseudoalteromonas species with validly published names. Therefore, it is proposed that strains JW1T and JW3 represent a novel species of the genus Pseudoalteromonas, for which the name Pseudoalteromonas amylolytica sp. nov. (type strain, JW1T = CGMCC 1.15681T = KCTC 52406T = MCCC 1K02162T) is proposed.

Alteromonas lipolytica sp. nov., a poly-beta-hydroxybutyrate-producing bacterium isolated from surface seawater.

Strain JW12T, isolated from surface seawater of the Arabian Sea, was subjected to characterization by a polyphasic taxonomic approach. Cells of the isolate were Gram-stain-negative, aerobic and rod-shaped. It accumulated poly-ß-hydroxybutyrate. On the basis of 16S rRNA gene sequence analysis, strain JW12T was closely related to Alteromonas confluentis, with 16S rRNA gene sequence similarity of 98.0 %. Phylogenetic analysis revealed that it fell within the cluster of the genus Alteromonas and represented one independent lineage with A. confluentis. The average nucleotide identity (ANI) value and the genome-to-genome distance between strain JW12T and A. confluentis KCTC 42603T were 70.0 and 21.3 %, respectively. The sole respiratory quinone was ubiquinone-8 (Q8). The principal fatty acids were summed feature 3 (C16 : 1ω7c and/or iso-C15 : 0 2-OH), C16 : 0 and C18 : 1ω7c. The major polar lipids included phosphatidylethanolamine, phosphatidylglycerol, two unidentified glycolipids and one aminophospholipid. The DNA G+C content was 48.4 mol%. Differential phylogenetic distinctiveness and chemotaxonomic differences, together with phenotypic properties obtained in this study, revealed that strain JW12T could be differentiated from the closely related species. Therefore, it is proposed that strain JW12T represents a novel species in the genus Alteromonas, for which the name Alteromonas lipolytica sp. nov. (type strain, JW12T=CGMCC 1.15735T=KCTC 52408T=MCCC 1K03175T), is proposed.

Croceicoccus pelagius sp. nov. and Croceicoccus mobilis sp. nov., isolated from marine environments.

Strain Ery9T, isolated from surface seawater of the Atlantic Ocean, and strain Ery22T, isolated from deep-sea sediment of the Indian Ocean, were subjected to a taxonomic study using a polyphasic approach. Cells of the two strains were Gram-stain-negative, aerobic and rod-shaped. They produced yellow pigments and lacked bacteriochlorophyll a. On the basis of 16S rRNA gene sequence analysis, strain Ery9T was closely related to Croceicoccus naphthovorans PQ-2T (with 16S rRNA gene sequence similarity of 97.7 %), and strain Ery22T was closely related to Croceicoccusmarinus E4A9T (98.3 %). The 16S rRNA gene sequence similarity between strain Ery9T and strain Ery22T was 96.6 %. Phylogenetic analyses revealed that strains Ery9T and Ery22T fell within the cluster of the genus Croceicoccus and represented two independent lineages. The average nucleotide identity (ANI) values and the genome-to-genome distances between strains Ery9T and Ery22T and the type strains of species of the genus Croceicoccus with validly published names were 73.7-78.4 % and 20.1-22.3 %, respectively. The major respiratory quinone of the two isolates was ubiquinone-10 (Q-10). The DNA G+C contents of strains Ery9T and Ery22T were 62.8 and 62.5 mol%, respectively. Differential phylogenetic distinctiveness and chemotaxonomic differences, together with phenotypic properties, revealed that strains Ery9T and Ery22T could be differentiated from their closely related species. Therefore, it is concluded that strains Ery9T and Ery22T represent two novel species of the genus Croceicoccus, for which the names Croceicoccus pelagius sp. nov. (type strain Ery9T=CGMCC 1.15358T=DSM 101479T) and Croceicoccus mobilis sp. nov. (type strain Ery22T=CGMCC 1.15360T=DSM 101481T), are proposed.

Parvularcula flava sp. nov., an alphaproteobacterium isolated from surface seawater of the South China Sea.

An aerobic, coccoid to short rod, yellow-pigmented, non-sporulating and Gram-staining-negative bacterium, designated NH6-79T, was isolated from surface seawater of the South China Sea. The isolate was motile with a polar flagellum. Growth was observed at 4-42 °C (optimum 37 °C), at pH 6.0-8.5 (optimum pH 7.0), and with 0.5-11 % (w/v) NaCl (optimum 4.5 %) and 1.5-17 % (w/v) sea salt (optimum 3.5-5 %). Strain NH6-79T could decompose peptone to produce H2S, but could not hydrolyse skimmed milk. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain NH6-79T had the closest affinity to the genus Parvularcula, sharing the highest 16S rRNA gene sequence similarity with 'Parvularcula oceanus' JLT2013 (94.1 %), Parvularcula lutaonensis CC-MMS-1T (93.4 %), Parvularcula dongshanensis SH25T (92.9 %) and Parvularcula bermudensis HTCC2503T (92.7 %), and lower sequence similarities (<90 %) with all other genera. The dominant fatty acids were C18 : 1ω7c and C16 : 0. The polar lipid profile was mainly composed of three unidentified glycolipids. The predominant isoprenoid quinone was ubiquinone-10. The DNA G+C content was 60.7 mol%. Based on the polyphasic taxonomic characterization, strain NH6-79T is considered to represent a novel species of the genus Parvularcula, for which the name Parvularcula flava sp. nov. is proposed. The type strain is NH6-79T (=CGMCC 1.14984T=JCM 30557T=MCCC 1K00277T).

Marinirhabdus gelatinilytica gen. nov., sp. nov., isolated from seawater.

A Gram-stain-negative, aerobic and slightly halophilic bacterium was isolated from the South China Sea, and was subjected to characterization using a polyphasic taxonomic approach. Cells of the isolate, designated NH83T, were non-motile and rod-shaped. On the basis of 16S rRNA gene sequence analysis, strain NH83Twas closely related to members of the genera Aureisphaera (with sequence similarity of 92.9 %), Jejudonia (92.8 %), Marixanthomonas (92.6 %), Altuibacter (92.6 %), Ulvibacter (91.5-91.9 %), Gilvibacter (91.8 %) and Aequorivita (89.6-91.2 %), all of which belong to the family Flavobacteriaceae. Phylogenetic analysis indicated that it represented an independent lineage and its closest relatives belonged to the genus Marixanthomonas. The sole respiratory quinone was MK-6. The major polar lipids were phosphatidylethanolamine, two aminolipids, one aminophospholipid and one unidentified lipid. The principal fatty acids were branched fatty acids, including iso-C15 : 0, iso-C17 : 0 3-OH, iso-C16 : 0, iso-C15 : 1 G and summed feature 3 (iso-C15 : 0 2-OH and/or C16 : 1ω7c). The genomic DNA G+C content was 41.0 mol%. Strain NH83T was positive for hydrolysis of aesculin, gelatin and Tween 60. Phylogenetic distinctiveness and chemotaxonomic differences, together with differential phenotypic properties, revealed that strain NH83T could be differentiated from closely related genera. Therefore, it is proposed that strain NH83T represents a novel species in a new genus, for which the name Marinirhabdus gelatinilytica gen. nov., sp. nov. (type strain NH83T=CGMCC 1.15462T=DSM 101478T) is proposed.

Sinimarinibacterium flocculans gen. nov., sp. nov., a gammaproteobacterium from offshore surface seawater.

Two aerobic, rod-shaped, non-motile, non-sporulating and Gram-staining-negative bacterial strains, namely NH6-24T and Za3-11, were isolated from the surface seawater of the South China Sea and the estuary of the Yangtze River, respectively. The two isolates grew at 14­44 °C (optimum 37­40 °C) and pH 6.0­8.5 (optimum pH 7.0­7.5). The sea salt ranges for growth were 0.5­10 % (w/v) (optimum 1­2.5 %) for strain NH6-24T and 0­12 % (w/v) (optimum 0.5­4.5 %) for strain Za3-11.Both strains could grow in the absence of NaCl. Results of phylogenetic analysis based on 16S rRNA gene sequences indicated that the two isolates showed closest affinity to the genera Fontimonas (96.0 %) and Solimonas (94.1­95.1 %) and formed a single lineage in the cluster of the family Solimonadaceae. The predominant isoprenoid quinone was ubiquinone-8.The major fatty acids were C18 : 1ω7c, iso-C16 : 0 and C16 : 0.The dominant polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The DNA G+C content was 65 mol%. Based on the polyphasic taxonomic characterization, strains NH6-24T and Za3-11 are considered to represent a novel species of a novel genus, for which the name Sinimarinibacterium flocculans gen. nov., sp. nov. is proposed. The type strain of the type species is NH6-24T ( = CGMCC 1.10815T = JCM 17607T) and an additional strain is Za3-11 ( = CGMCC 1.10816 = JCM 17606).

Recombinant adenovirus-mediated human telomerase reverse transcriptase gene can stimulate cell proliferation and maintain primitive characteristics in bovine mammary gland epithelial cells.

The human telomerase reverse transcriptase (hTERT) gene has been used to stimulate the proliferation of most types of human cells. The present study was designed to evaluate the feasibility and efficiency of adenovirus-mediated hTERT in the proliferation of bovine mammary gland epithelial cells (bMGEs). A plasmid and an adenovirus vector that carried hTERT, namely pEGFP- hTERT and Ad- hTERT, were constructed and transfected into bMGEs, respectively. In order to select the best strategy for stimulating cell proliferation, the adenovirus- and plasmid-mediated hTERT were compared in terms of the positive cloning and transgenic efficiency. The results showed that only Ad- hTERT had high infection efficiency and produced a positive polyclone population (hTERT-bMGEs). The characteristics of the hTERT-bMGEs were investigated with further analysis by reverse transcription-polymerase chain reaction (RT-PCR), western blotting, proliferation assays, and flow cytometry, which showed that hTERT facilitated strong cell proliferation. Real-time quantitative PCR showed a normal level of expression of beta-casein, the caspase-8 and c-myc proto-oncogene, and immunofluorescence demonstrated the properties of the epithelial cells. In conclusion, the adenovirus-mediated hTERT gene could not only extend the cell lifespan, but also maintained the primary characteristics of the cells. It may be possible to extend the use of a wide variety of non-human mammalian cells in this way. This study has provided additional insight into the mechanism of cell proliferation by demonstrating the lack of integration of the adenovirus-mediated hTERT gene into the mammalian genome.

Microbulbifer donghaiensis sp. nov., isolated from marine sediment of the East China Sea.

A Gram-negative, aerobic, neutrophilic, rod-shaped bacterium, designated strain CN85(T), was isolated from a sediment sample collected from the East China Sea and was subjected to a polyphasic taxonomic characterization. This isolate grew in the presence of 0.5-6.0 % (w/v) NaCl and at 20-40 degrees C; optimum growth was observed with 3 % (w/v) NaCl and at 35 degrees C. Chemotaxonomic analysis showed that Q-8 was the predominant respiratory quinone and that iso-C(15 : 0), iso-C(11 : 0) 3-OH, iso-C(17 : 1)omega9c, iso-C(17 : 0), iso-C(11 : 0) and C(16 : 0) were the major fatty acids. The G+C content of the genomic DNA was 57.8 mol%. On the basis of 16S rRNA gene sequence analysis, the isolate was affiliated to the genus Microbulbifer. Strain CN85(T) exhibited most phylogenetic affinity with respect to the type strain of Microbulbifer maritimus (97.0 % sequence similarity) and showed less than 97 % sequence similarity with respect to other described Microbulbifer species with known 16S rRNA gene sequences. The DNA-DNA hybridization between strain CN85(T) and M. maritimus JCM 12187(T) was 44 %. On the basis of phenotypic and genotypic data, strain CN85(T) represents a novel species of the genus Microbulbifer, for which the name Microbulbifer donghaiensis sp. nov. is proposed. The type strain is CN85(T) (=CGMCC 1.7063(T) =JCM 15145(T)).

Halomonas salifodinae sp. nov., a halophilic bacterium isolated from a salt mine in China.

A Gram-negative, aerobic, motile, halophilic bacterium, designated strain BC7(T), was isolated from a salt mine in north-western China and was subjected to a polyphasic taxonomic characterization. The isolate was able to grow in the presence of 0.5-20 % (w/v) NaCl and at pH 6.0-9.0 and 4-48 degrees C; optimum growth was observed with 3 % (w/v) NaCl and at pH 7.0 and 30 degrees C. Cells were long rods, 0.8-1.2 microm wide and 4.0-6.0 microm long. The major fatty acids were C(18 : 1)omega7c, C(16 : 0) and C(16 : 0)omega7c. The DNA G+C content was 65.5 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain BC7(T) belonged to the genus Halomonas and showed highest sequence similarity to the type strain of Halomonas pacifica (99.2 %). Levels of DNA-DNA relatedness between strain BC7(T) and H. pacifica CGMCC 1.2314(T) and Halomonas taeanensis DSM 16463(T) were 51 and 38 %, respectively. On the basis of phenotypic and genotypic data, strain BC7(T) is considered to represent a novel species of the genus Halomonas, for which the name Halomonas salifodinae sp. nov. is proposed. The type strain is BC7(T) (=CGMCC 1.6774(T) =JCM 14803(T)).

Halomonas caseinilytica sp. nov., a halophilic bacterium isolated from a saline lake on the Qinghai-Tibet Plateau, China.

A halophilic, Gram-negative bacterial strain, designated AJ261T, which was isolated from a soil sample from a salt lake on the Qinghai-Tibet Plateau, was subjected to a polyphasic taxonomic study. The isolate grew optimally in the presence of 3-5 % NaCl and used various carbohydrates as sole carbon and energy sources. The genomic DNA G+C content was 63.0 mol%. The predominant fatty acids were C18 : 1omega7c, C16 : 0 and C12 : 0. A phylogenetic analysis based on 16S rRNA gene sequences indicated that the isolate had the highest sequence similarity with respect to type strains of Halomonas elongata (98.2 %), Halomonas eurihalina (98.1 %) and Halomonas halmophila (97.2 %). The DNA-DNA relatedness of strain AJ261T with respect to H. elongata NBRC 15536T, H. eurihalina CGMCC 1.2318T and H. halmophila DSM 5349T was 42, 25 and 26 %, respectively. Overall, the phenotypic, genotypic and phylogenetic results demonstrate that strain AJ261T represents a novel species within the genus Halomonas, for which the name Halomonas caseinilytica is proposed. The type strain is AJ261T (=CGMCC 1.6773T =JCM 14802T).