Phaeobacter aquaemixtae sp. nov., isolated from the junction between the ocean and a freshwater spring

Phycobacter azelaicus gen. nov. sp. nov., a diatom symbiont isolated from the phycosphere of Asterionellopsis glacialis

A diatom-associated bacterium, designated as strain F10T, was isolated from a pure culture of the pennate diatom Asterionellopsis glacialis A3 and has since been used to characterize molecular mechanisms of symbiosis between phytoplankton and bacteria, including interactions using diatom-derived azelaic acid. Its origin from a hypersaline environment, combined with its capacity for quorum sensing, biofilm formation, and potential for dimethylsulfoniopropionate methylation/cleavage, suggest it is within the family Roseobacteraceae. Initial phylogenetic analysis of the 16S rRNA gene sequence placed this isolate within the Phaeobacter genus, but recent genomic and phylogenomic analyses show strain F10T is a separate lineage diverging from the genus Pseudophaeobacter. The genomic DNA G+C content is 60.0 mol%. The predominant respiratory quinone is Q-10. The major fatty acids are C18 : 1 ω7c and C16 : 0. Strain F10T also contains C10 : 03-OH and the furan-containing fatty acid 10,13-epoxy-11-methyl-octadecadienoate (9-(3-methyl-5-pentylfuran-2-yl)nonanoic acid). The major polar lipids are diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol. Based on genomic, phylogenomic, phenotypic and chemotaxonomic characterizations, strain F10T represents a novel genus and species with the proposed name, Phycobacter azelaicus gen. nov. sp. nov. The type strain is F10T (=NCMA B37T=NCIMB 15470T=NRIC 2002T).

Pseudophaeobacter flagellatus sp. nov., isolated from coastal water

A Gram-stain-negative, aerobic, motile, rod-shaped novel bacterial strain, designated as MA21411-1T, was isolated from the Korean coast. The colonies were white-yellow-coloured, smooth, convex and entire, spherical and 1.0–1.8 mm in diameter. Phylogenetic analysis based on the 16S rRNA gene sequence showed that strain MA21411-1T is closely related to species of the genus Pseudophaeobacter . The 16S rRNA gene sequence similarities between strain MA21411-1T and Pseudophaeobacter arcticus DSM 23566T, Phaeobacter porticola DSM 103148T and Pseudophaeobacter leonis DSM 25627T were 98.31, 97.80 and 97.28 %, respectively. Strain MA21411-1T has a draft genome size of 4 294 042 bp, annotated with 4125 protein-coding genes, and 53 tRNA, three rRNA and one tmRNA genes. The genomic DNA G+C content was 59.2 mol%. Comparative genome analysis revealed that the average nucleotide identity, digital DNA–DNA hybridization and average amino acid identity values among strain MA21411-1T and other related species were below the cut-off levels of 95, 70 and 95.5 %, respectively. The growth temperature range for growth was 15–28 °C (optimum, 25 °C), pH range was 6.0–9.0 (optimum, pH 6.0), and salt tolerance range was 0.5–4 % (optimum 0.5 %). Ubiquinone-10 was the sole quinone present in MA21411-1T and all three closely related strains. The major cellular fatty acid (>10 %) of the strain was summed feature 8 (C18 : 1  ω7c and/or C18 : 1  ω6c). The polar lipid profile contained phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine and four unidentified polar lipids. Based on the phylogenetic tree, as well as phenotypic, chemotaxonomic and genomic features, strain MA21411-1T represents a novel species of the genus Pseudophaeobacter , for which the name Pseudophaeobacter flagellatus sp. nov. is proposed. The type strain is MA21411-1T (=KCTC 92095T=GDMCC 1.2988T).

Thiosulfatihalobacter marinus gen. nov. sp. nov., a novel member of the family Roseobacteraceae, isolated from the West Pacific Ocean

Two strains (GL-11-2T and ZH2-Y79) were isolated from the seawater collected from the West Pacific Ocean and the East China Sea, respectively. Cells were Gram-stain-negative, strictly aerobic, non-motile and rod-shaped. Cells grew in the medium containing 0.5–7.5 % NaCl (w/v, optimum, 1.0–3.0 %), at pH 6.0–8.0 (optimum, pH 6.5–7.0) and at 4–40 °C (optimum, 30 °C). H2S production occurred in marine broth supplemented with sodium thiosulphate. The almost-complete 16S rRNA gene sequences of the two isolates were identical, and exhibited the highest similarity to Pseudoruegeria aquimaris JCM 13603T (97.5 %), followed by Ruegeria conchae TW15T (97.2%), Shimia aestuarii DSM 15283T (97.1 %) and Ruegeria lacuscaerulensis ITI-1157T (97.0 %). Phylogenetic analysis revealed that the isolates were affiliated with the family Roseobacteraceae and represented an independent lineage. The sole isoprenoid quinone was ubiquinone 10. The principal fatty acids were summed feature 8 (C18 : 1  ω7c and/or C18 : 1  ω6c) and cyclo-C19 : 0  ω8c. The major polar lipids were phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine and diphosphatidylglycerol. The DNA G+C content was 62.3 mol%. The orthologous average nucleotide identity, in silico DNA–DNA hybridization and average amino acid identity values among the genomes of strain GL-11-2T and the reference strains were 73.2–79.0, 20.3–22.5 and 66.0–80.8 %, respectively. Strains GL-11-2ᵀ and ZH2-Y79 possessed complete metabolic pathways for thiosulphate oxidation, dissimilatory nitrate reduction and denitrification. Phylogenetic distinctiveness, chemotaxonomic differences and phenotypic properties revealed that the isolates represent a novel genus and species of the family Roseobacteraceae , belonging to the class Alphaproteobacteria , for which the name Thiosulfatihalobacter marinus gen. nov., sp. nov. (type strain, GL-11–2T=KCTC 82723T=MCCC M20691T) is proposed.

Two New Biocontrol Agents Against Clubroot Caused by Plasmodiophora brassicae

Clubroot disease caused by Plasmodiophora brassicae can lead to serious yield losses in crucifers such as Brassica napus. In this study, 323 bacterial strains were isolated from the rhizosphere of severely diseased B. napus in Dangyang county, Hubei province, China. Antagonistic strains were first identified based on dual culture inhibition zones with Fusarium oxysporum and Magnaporthe oryzae. These were then further screened in germination inhibition and viability assays of resting spores of P. brassicae. Finally, eight of the antagonistic strains were found to significantly reduce the disease severity of clubroot by more than 40% under greenhouse conditions, and two strains, F85 and T113, were found to have efficacy of more than 80%. Root hair infection experiments showed that F85 and T113 can inhibit early infection of root hairs, reduce the differentiation of primary plasmodia of P. brassicae, and inhibit formation of secondary zoosporangia. Based on sequence analysis of 16S rDNA gene, gyrA gene and 22 housekeeping genes as well as carbon source utilization analysis, the F85 was identified as Bacillus velezensis and T113 as Bacillus amyloliquefaciens. Genome analysis, PCR and RT-PCR detection revealed that both F85 and T113 harbor various antibiotic biosynthesis gene clusters required to form peptides with antimicrobial activity. To our knowledge, this is the first report of B. velezensis as a biocontrol agent against clubroot disease.

Thalassotalea mangrovi sp. nov., a bacterium isolated from marine mangrove sediment

A novel Gram-stain-negative, strictly aerobic bacterium that has a rod-like shape with a single polar flagellum in the exponential phase of growth and a spherical or ovoid shape without a flagellum in the stationary phase was isolated from a mangrove wetland sediment sample collected at Beilun Estuary National Nature Reserve, Guangxi Province, PR China and designated strain ZS-4^T. This strain grew optimally at pH 6.0-8.0, at a temperature of 37 °C and in the presence of 3-4 % (w/v) NaCl. Its polar lipid profile included phosphatidylethanolamine, phosphatidylglycerol, one unidentified aminophospholipid and two uncharacterized lipids. Ubiquinone 8 (Q-8) was the sole respiratory quinone and the cellular fatty acids were dominated by C_17 : 1ω8c and C_16 : 0. A phylogenetic analysis based on the 16S rRNA gene sequence showed that strain ZS-4^T exhibited its highest similarities to the type strains Thalassotalea litorea HMF4135^T (97.8 %) and Thalassotalea ponticola GJSW-36^T (95.9 %). A whole genome-level comparison of strain ZS-4^T with T. litorea MCCC 1K03283^T revealed an average nucleotide identity value of 75.6 % and a calculated DNA-DNA hybridization value of 19.6 %. In addition, the genomic DNA G+C content of strain ZS-4^T was 45.9 mol%. Thus, based on analyses of its morphology, physiology, fatty acid composition and 16S rRNA gene sequence, strain ZS-4^T should be considered a novel species of the genus Thalassotalea, with the proposed name Thalassotaleamangrovi sp. nov. The type strain is ZS-4^T (=KCTC 72399^T=MCCC 1K03630^T).

Complete Genome Sequence of Leisingera aquamixtae R2C4, Isolated from a Self-Regenerating Biocathode Consortium

Here, we present the complete genome sequence of Leisingera aquamixtae R2C4, isolated from the electroautotrophic microbial consortium biocathode MCL (Marinobacter-Chromatiaceae-Labrenzia). As an isolate of a current-producing system, the genome sequence of L. aquamixtae will yield insights regarding electrode-associated microorganisms and communities. A dark pigment is also observed during cultivation.

Here, we present the complete genome sequence of Leisingera aquamixtae R2C4, isolated from the electroautotrophic microbial consortium biocathode MCL (Marinobacter-Chromatiaceae-Labrenzia). As an isolate of a current-producing system, the genome sequence of L. aquamixtae will yield insights regarding electrode-associated microorganisms and communities. A dark pigment is also observed during cultivation.

Confluentibacter flavum sp. nov., Isolated from the Saline Lake

A Gram-stain-negative, rod-shaped, non-motile, bacterial isolate designated 3B^T, was isolated from a saline lake, and subjected to a polyphasic taxonomic investigation. The phylogenetic analysis based on 16S rRNA gene sequence clearly showed an allocation to the genus Confluentibacter with similarity ranging from 95.1 to 98%. OrthoANI values between strain 3B^T and related strains of Confluentibacter (< 90%) were lower than the threshold value of 95% ANI relatedness recommended for species demarcation. Strain 3B^T grew at 4-35 °C and pH 6.0-8.0 (optimum, 28 °C and pH 6.5) and with 0-3% (w/v) NaCl (optimum, 0.5%). The predominant respiratory quinone was menaquinone-6 (MK-6) and the major fatty acids were iso-C_15:0, iso-C_15:1 G, iso-C_15:0 3-OH, and iso-C_17:0 3-OH. The polar lipid profile of strain 3B^T comprised phosphatidylethanolamine, one unidentified aminolipid, one aminophospholipid, and three unidentified lipids (L1-3). The DNA G+C content was 33.1 mol%. On the basis of morphological, physiological, and chemotaxonomic characteristics, together with the results of phylogenetic analysis, strain 3B^T is described as a novel species in genus Confluentibacter, for which the name Confluentibacter flavum sp. nov. (type strain 3B^T = CGMCC115960^T = KCTC52969^T) is proposed.

Phylogenetic distribution of roseobacticides in the Roseobacter group and their effect on microalgae

The Roseobacter-group species Phaeobacter inhibens produces the antibacterial tropodithietic acid (TDA) and the algaecidal roseobacticides with both compound classes sharing part of the same biosynthetic pathway. The purpose of this study was to investigate the production of roseobacticides more broadly in TDA-producing roseobacters and to compare the effect of producers and non-producers on microalgae. Of 33 roseobacters analyzed, roseobacticide production was a unique feature of TDA-producing P. inhibens, P. gallaeciensis and P. piscinae strains. One TDA-producing Phaeobacter, 27-4, did not produce roseobacticides, possibly due to a transposable element. TDA-producing Ruegeria and Pseudovibrio did not produce roseobacticides. Addition of roseobacticide-containing bacterial extracts affected the growth of the microalgae Rhodomonas salina, Thalassiosira pseudonana and Emiliania huxleyi, while growth of Tetraselmis suecica was unaffected. During co-cultivation, growth of E. huxleyi was initially stimulated by the roseobacticide producer DSM 17395, while the subsequent decline in algal cell numbers during senescence was enhanced. Strain 27-4 that does not produce roseobacticides had no effect on algal growth. Both bacterial strains, DSM 17395 and 27-4, grew during co-cultivation presumably utilizing algal exudates. Furthermore, TDA-producing roseobacters have potential as probiotics in marine larviculture and it is promising that the live feed Tetraselmis was unaffected by roseobacticides-containing extracts.

Aestuariibius insulae gen. nov., sp. nov., isolated from a tidal flat sediment

A Gram-stain-negative, non-motile and ovoid or rod-shaped bacterial strain, DBTF-13^T, which was isolated from a tidal flat sediment of the Yellow Sea in South Korea, was characterized taxonomically. Strain DBTF-13^T grew optimally at 25-30 °C and pH 7.0-8.0, and in the presence of 2.0 % (w/v) NaCl. The phylogenetic trees based on 16S rRNA gene sequences revealed that strain DBTF-13^T formed an evolutionary lineage independent of other genera, including the genera Pseudooctadecabacter and Octadecabacter. Strain DBTF-13^T exhibited 16S rRNA gene sequence similarity values of 96.9 % to the type strain of Pseudooctadecabacter jejudonensis, and of 95.8-96.5 % to the type strains of Octadecabacter species. Strain DBTF-13^T contained Q-10 as the predominant ubiquinone and C18 : 1ω7c and C16 : 0 as the major fatty acids. The major polar lipids of strain DBTF-13^T were phosphatidylcholine, phosphatidylglycerol, one unidentified aminolipid and one unidentified lipid. The DNA G+C content of strain DBTF-13^T was 61.6 mol%. The chemotaxonomic data and other differential phenotypic properties made it reasonable to differentiate strain DBTF-13^T from the genera Pseudooctadecabacter and Octadecabacter. On the basis of the data presented, strain DBTF-13^T constitutes a new genus and species within the class Alphaproteobacteria, for which the name Aestuariibius insulae gen. nov., sp. nov. is proposed. The type strain is DBTF-13^T (=KACC 19432^T=NBRC 113038^T).

A denitrifying community associated with a major, marine nitrogen fixer

The diazotrophic cyanobacterium, Trichodesmium, is an integral component of the marine nitrogen cycle and contributes significant amounts of new nitrogen to oligotrophic, tropical/subtropical ocean surface waters. Trichodesmium forms macroscopic, fusiform (tufts), spherical (puffs) and raft-like colonies that provide a pseudobenthic habitat for a host of other organisms including marine invertebrates, microeukaryotes and numerous other microbes. The diversity and activity of denitrifying bacteria found in association with the colonies was interrogated using a series of molecular-based methodologies targeting the gene encoding the terminal step in the denitrification pathway, nitrous oxide reductase (nosZ). Trichodesmium spp. sampled from geographically isolated ocean provinces (the Atlantic Ocean, the Red Sea and the Indian Ocean) were shown to harbor highly similar, taxonomically related communities of denitrifiers whose members are affiliated with the Roseobacter clade within the Rhodobacteraceae (Alphaproteobacteria). These organisms were actively expressing nosZ in samples taken from the mid-Atlantic Ocean and Red Sea implying that Trichodesmium colonies are potential sites of nitrous oxide consumption and perhaps earlier steps in the denitrification pathway also. It is proposed that coupled nitrification of newly fixed N is the most likely source of nitrogen oxides supporting nitrous oxide cycling within Trichodesmium colonies.

Characterization of Marinovum faecis sp. nov., an alphaproteobacterium isolated from marine sediment

A Gram-negative, strictly aerobic, chemoheterotrophic, beige-pigmented, ovoid bacterium, designated YP194^T, was isolated from marine sediment in the Republic of Korea. A phylogenetic analysis based on the 16S rRNA gene sequence indicated that the novel marine strain belongs to the family Rhodobacteraceae of the class Alphaproteobacteria, with high sequence similarity (98.4%) to Marinovum algicola FF3^T. The DNA-DNA relatedness values between strains YP194^T and M. algicola FF3^T were 34.1 ± 2.7%. The DNA G+C content of strain YP194^T was 63.1 mol%. Ubiquinone 10 (Q-10) was the sole respiratory quinone. The predominant cellular fatty acid was C18:1 ω7c (77.6%). Strain YP194^T produced phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, an unidentified aminolipid, an unidentified phospholipid and two unidentified lipids as polar lipids. From the combination of genotypic and phenotypic characteristics and the distinct phylogenetic position, the strain is considered to represent a novel species of the genus Marinovum for which the name Marinovum faecis sp. nov. is proposed. The type strain of M. faecis sp. nov. is YP194^T (= KCCM 90263^T = NBRC 111905^T).

Draft genome sequence of the marine Rhodobacteraceae strain O3.65, cultivated from oil-polluted seawater of the Deepwater Horizon oil spill

The marine alphaproteobacterium strain O3.65 was isolated from an enrichment culture of surface seawater contaminated with weathered oil (slicks) from the Deepwater Horizon (DWH) oil spill and belongs to the ubiquitous, diverse and ecological relevant Roseobacter group within the Rhodobacteraceae. Here, we present a preliminary set of physiological features of strain O3.65 and a description and annotation of its draft genome sequence. Based on our data we suggest potential ecological roles of the isolate in the degradation of crude oil within the network of the oil-enriched microbial community. The draft genome comprises 4,852,484 bp with 4,591 protein-coding genes and 63 RNA genes. Strain O3.65 utilizes pentoses, hexoses, disaccharides and amino acids as carbon and energy source and is able to grow on several hydroxylated and substituted aromatic compounds. Based on 16S rRNA gene comparison the closest described and validated strain is Phaeobacter inhibens DSM 17395, however, strain O3.65 is lacking several phenotypic and genomic characteristics specific for the genus Phaeobacter. Phylogenomic analyses based on the whole genome support extensive genetic exchange of strain O3.65 with members of the genus Ruegeria, potentially by using the secretion system type IV. Our physiological observations are consistent with the genomic and phylogenomic analyses and support that strain O3.65 is a novel species of a new genus within the Rhodobacteraceae.

Arcobacter acticola sp. nov., isolated from seawater on the East Sea in South Korea

A Gram-stain-negative, facultative aerobic, non-flagellated, and rod-shaped bacterium, designated AR-13(T), was isolated from a seawater on the East Sea in South Korea, and subjected to a polyphasic taxonomic study. Strain AR-13(T) grew optimally at 30°C, at pH 7.0-8.0 and in the presence of 0-0.5% (w/v) NaCl. The phylogenetic trees based on 16S rRNA gene sequences showed that strain AR-13(T) fell within the clade comprising the type strains of Arcobacter species, clustering coherently with the type strain of Arcobacter venerupis. Strain AR-13(T) exhibited 16S rRNA gene sequence similarity values of 98.1% to the type strain of A. venerupis and of 93.2-96.9% to the type strains of the other Arcobacter species. Strain AR-13(T) contained MK-6 as the only menaquinone and summed feature 3 (C16:1 ω7c and/or C16:1 ω6c), C16:0, C18:1 ω7c, and summed feature 2 (iso-C16:1 I and/or C14:0 3-OH) as the major fatty acids. The major polar lipids detected in strain AR-13(T) were phosphatidylethanolamine, phosphatidylglycerol, and one unidentified aminophospholipid. The DNA G+C content was 28.3 mol% and its mean DNA-DNA relatedness value with the type strain of A. venerupis was 21%. Differential phenotypic properties, together with its phylogenetic and genetic distinctiveness, revealed that strain AR-13(T) is separated from recognized Arcobacter species. On the basis of the data presented, strain AR-13(T) is considered to represent a novel species of the genus Arcobacter, for which the name Arcobacter acticola sp. nov. is proposed. The type strain is AR-13(T) (=KCTC 52212(T) =NBRC 112272(T)).

Devosia confluentis sp. nov., isolated from the junction between the ocean and a freshwater lake, and reclassification of two Vasilyevaea species as Devosia enhydra comb. nov. and Devosia mishustinii comb. nov

A Gram-stain-negative, aerobic, non-flagellated and pleomorphic bacterium, designated HJR-2T, was isolated from a junction between the ocean and a freshwater lake on the East Sea, South Korea. It grew optimally at 30 °C, at pH 7.0-8.0 and in the presence of 0-1.5 % (w/v) NaCl. In the neighbour-joining phylogenetic tree based on 16S rRNA gene sequences, strain HJR-2T clustered with the type strains of Vasilyevaea enhydra and Vasilyevaea mishustinii and this cluster fell within the clade comprising the type strains of Devosia species. Strain HJR-2T exhibited 16S rRNA gene sequence similarity values of 97.2 and 97.0 % to the type strains of V. enhydra and V. mishustinii, respectively, and 93.9-96.2 % to the type strains of Devosia species. Strain HJR-2T contained Q-10 as the predominant ubiquinone and C18 : 1ω7c, 11-methyl C18 : 1ω7c and C16 : 0 as major fatty acids. Major polar lipids of strain HJR-2T were phosphatidylglycerol and two unidentified glycolipids. The DNA G+C content was 66.0 mol% and its mean DNA-DNA relatedness values with the type strains of V. enhydra and V. mishustinii were 11-17 %. Differential phenotypic properties, together with its phylo genetic and genetic distinctiveness, revealed that strain HJR-2T is separated from V. enhydra, V. mishustinii and Devosia species. On the basis of the data presented, strain HJR-2T (=KCTC 52211T=NBRC 112271T) is considered to be the type strain of a novel species of the genus Devosia, for which the name Devosiaconfluentis sp. nov. is proposed. In this study, it is also proposed that V. enhydra and V. mishustinii be reclassified as members of the genus Devosia.

Cribrihabitans pelagius sp. nov., a marine alphaproteobacterium isolated from seawater

A Gram-stain-negative, strictly aerobic, cream-coloured, motile, chemoheterotrophic, rod-shaped bacterium, designated strain KMU-32T, was isolated from seawater at Najeong Beach in Korea. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that the novel isolate was affiliated with the family Rhodobacteraceae of the class Alphaproteobacteria and that it showed highest sequence similarity (98.2 %) to Cribrihabitans neustonicus CC-AMHB-3T. The DNA-DNA relatedness value between strain KMU-32T and C. neustonicus CC-AMHB-3T was 48.5 ± 4 %. The DNA G+C content of strain KMU-32T was determined to be 63.7 mol%. Ubiquinone 10 (Q-10) was the sole respiratory quinone. The predominant cellular fatty acid was C18 : 1ω7c. Strain KMU-32T had diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, an unidentified aminolipid and an unidentified lipid as polar lipids. From the distinct phylogenetic position and combination of genotypic and phenotypic characteristics, strain KMU-32T is considered to represent a novel species of the genus Cribrihabitans, for which the name Cribrihabitans pelagius sp. nov. is proposed. The type strain is KMU-32T (= KCTC 42981T = NBRC 111834T).

Colwellia sediminilitoris sp. nov., isolated from a tidal flat

A Gram-stain-negative, aerobic, motile and rod-shaped or ovoid bacterial strain, designated YSM-23T, was isolated from a tidal flat on the South Sea in South Korea, and subjected to a polyphasic taxonomic study. Strain YSM-23T grew optimally at 30 °C, at pH 7.0-8.0 and in the presence of 1.0-2.0 % (w/v) NaCl. The phylogenetic trees based on 16S rRNA gene sequences showed that strain YSM-23T represented a member of the genus Colwellia. Strain YSM-23T exhibited 16S rRNA gene sequence similarity values of 98.0, 97.4 and 97.3 % to the type strains of Colwellia aestuarii, Colwellia polaris and Colwellia chukchiensis, respectively, and of 94.5-96.8 % to the type strains of the other species of the genus Colwellia. Strain YSM-23T contained Q-8 as the predominant ubiquinone and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) as the major fatty acid. The major polar lipids detected in strain YSM-23T were phosphatidylglycerol and phosphatidylethanolamine. The DNA G+C content of strain YSM-23T was 43.8±0.08 mol% and its DNA-DNA relatedness values with the type strain of C. aestuarii, C. polaris and C. chukchiensis were 10±3.5-22±4.9 %. Differential phenotypic properties, together with its phylogenetic and genetic distinctiveness, revealed that strain YSM-23T is separated from species of the genus Colwelliawith validly published names. On the basis of the data presented, strain YSM-23T is considered to represent a novel species of the genus Colwellia, for which the name Colwellia sediminilitoris sp. nov. is proposed. The type strain is YSM-23T (=KCTC 52213T=NBRC 111994T).

Paracoccus aestuariivivens sp. nov., isolated from a tidal flat

A Gram-stain-negative, non-spore-forming, non-motile and coccoid, ovoid or short-rod-shaped bacterial strain, designated GHD-30T, was isolated from a tidal flat on the Yellow Sea in South Korea, and subjected to a polyphasic taxonomic study. Strain GHD-30T grew optimally at 30 °C, at pH 6.5-7.5 and in the presence of 2.0 % (w/v) NaCl. The phylogenetic trees based on 16S rRNA gene sequences showed that strain GHD-30Trepresented a member of the genus Paracoccus. Strain GHD-30T exhibited 16S rRNA gene sequence similarity values of 97.10-97.33 % to the type strains of Paracoccus lutimaris, Paracoccus limosus and Paracoccus halophilus and of 94.35-96.97 % to the type strains of the other species of the genus Paracoccus. Strain GHD-30T contained Q-10 as the predominant ubiquinone and C18 : 1ω7c as the major fatty acid. The major polar lipids detected in strain GHD-30T were phosphatidylcholine, phosphatidylglycerol, diphosphatidylglycerol, one unidentified glycolipid and one unidentified aminolipid. The DNA G+C content of strain GHD-30T was 62.0 mol% and its mean DNA-DNA relatedness values with the type strains of P. lutimaris, P. limosus, and P. halophilus were 11-19 %. Differential phenotypic properties, together with its phylogenetic and genetic distinctiveness, revealed that strain GHD-30T is separated from recognized species of the genus Paracoccus. On the basis of the data presented, strain GHD-30T is considered to represent a novel species of the genus Paracoccus, for which the name Paracoccus aestuariivivens sp. nov. is proposed. The type strain is GHD-30T (=KCTC 52214T =NBRC 111993T).

Pseudoalteromonas aestuariivivens sp. nov., isolated from a tidal flat

A Gram-stain-negative, aerobic, motile, rod-shaped or ovoid bacterial strain, designated DB-2T, was isolated from a tidal flat of the Yellow Sea in South Korea, and subjected to a taxonomic study using a polyphasic approach. Strain DB-2T grew optimally at 30 °C, at pH 7.0-8.0 and in the presence of 2.0-3.0 % (w/v) NaCl. Phylogenetic trees based on 16S rRNA gene sequences showed that strain DB-2T belonged to the genus Pseudoalteromonas. Strain DB-2T exhibited 16S rRNA gene sequence similarities of 97.17-97.36 % to the type strains of Pseudoalteromonas mariniglutinosa, Pseudoalteromonas spongiae and Pseudoalteromonas tetraodonis and of 93.79-96.99 % to the type strains of the other species of the genus Pseudoalteromonas. Strain DB-2T contained Q-8 as the predominant ubiquinone and C16 : 0, C18 : 1ω7c, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and C12 : 0 3-OH as the major fatty acids. The major polar lipids detected in strain DB-2T were phosphatidylglycerol, phosphatidylethanolamine, two unidentified glycolipids, an unidentified phospholipid and an unidentified aminolipid. The DNA G+C content of strain DB-2T was 54.9 ± 0.2 mol% and mean DNA-DNA relatedness values with the type strains of P. mariniglutinosa, P. spongiae and P. tetraodonis were 10-17 %. Differential phenotypic properties, together with phylogenetic and genetic distinctiveness, revealed that strain DB-2T is separated from recognized species of the genus Pseudoalteromonas. On the basis of these data, strain DB-2T is considered to represent a novel species of the genus Pseudoalteromonas, for which the name Pseudoalteromonas aestuariivivens sp. nov. is proposed. The type strain is DB-2T ( = KCTC 42779T = CECT 8945T).

Marinobacterium aestuariivivens sp. nov., isolated from a tidal flat

A Gram-stain-negative, motile, aerobic, rod- or ovoid-shaped bacterium, designated DB-1T, was isolated from a tidal flat on the Yellow Sea in South Korea and subjected to a taxonomic study using a polyphasic approach. Strain DB-1T grew optimally at 30 °C, at pH 7.0-8.0 and in the presence of 0.5-2.0% (w/v) NaCl. The neighbour-joining phylogenetic tree based on 16S rRNA gene sequences revealed that strain DB-1T falls within the clade comprising species of the genus Marinobacterium, clustering coherently with the type strain of Marinobacterium nitratireducens and showing a sequence similarity value of 98.4 %. The novel strain exhibited 16S rRNA gene sequence similarities of 91.5-94.4 % to the type strains of other species of the genus Marinobacterium. Strain DB-1T contained Q-8 as the predominant ubiquinone and C18:1ω7c, summed feature 3 (C16:1ω7c and/or C16:1ω6c) and C16:0 as the major fatty acids. The major polar lipids detected in strain DB-1T were phosphatidylethanolamine, phosphatidylglycerol, one unidentified aminolipid, one unidentified glycolipid, one unidentified phospholipid and two unidentified lipids. The DNA G+C content of strain DB-1T was 62.3 mol% and the mean DNA-DNA relatedness value with the type strain of M. nitratireducens was 21±4.6%. Differential phenotypic properties, together with phylogenetic and genetic distinctiveness, revealed that strain DB-1T is separated from recognized species of the genus Marinobacterium. On the basis of the data presented, strain DB-1T is considered to represent a novel species of the genus Marinobacterium, for which the name Marinobacterium aestuariivivens sp. nov. is proposed. The type strain is DB-1T (=KCTC 42778T=NBRC 111756T).

Draft genome of Leisingera aquaemixtae CECT 8399(T), a member of the Roseobacter clade isolated from a junction of fresh and ocean water in Jeju Island, South Korea

We report the draft genome sequence and annotation of Leisingera aquaemixtae CECT 8399(T) (DDBJ/EMBL/GenBank accession number CYSR00000000) which comprises 4,614,060 bp, 4313 protein coding genes, 54 tRNA coding genes and 7 rRNA coding genes. General findings of the annotated genome, such as pigment indigoidine operon, phenylacetate oxidation genes or predictable number of replicons, are commented in comparison to other Leisingera species. Average Nucleotide Identity between available genomes of type strains of species of Leisingera and Phaeobacter genera has been calculated to evaluate its current classification.

Marinobacter confluentis sp. nov., a lipolytic bacterium isolated from a junction between the ocean and a freshwater lake

A Gram-stain-negative, motile, aerobic and rod-shaped bacterium, designated HJM-18T, was isolated from the place where the ocean and a freshwater lake meet at Hwajinpo, South Korea, and subjected to a taxonomic study using a polyphasic approach. Strain HJM-18T grew optimally at 30 °C, at pH 7.0–8.0 and in the presence of 1.0–3.0 % (w/v) NaCl. Phylogenetic trees based on 16S rRNA gene sequences showed that strain HJM-18T belonged to the genus Marinobacter. Strain HJM-18T exhibited 16S rRNA gene sequence similarity values of 97.05–98.22 % to the type strains of Marinobacter algicola, Marinobacter flavimaris, Marinobacter adhaerens, Marinobacter salarius, Marinobacter salsuginis, Marinobacter guineae and Marinobacter gudaonensis and of 93.21–96.98 % to the type strains of the other species of the genus Marinobacter. Strain HJM-18T contained Q-9 as the predominant ubiquinone and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), C16 : 0 and C18 : 1ω9c as the major fatty acids. The major polar lipids detected in strain HJM-18T were phosphatidylethanolamine, phosphatidylglycerol and one unidentified aminophospholipid. The DNA G+C content was 58 mol% and the mean DNA–DNA relatedness values with the type strains of the seven phylogenetically related species of the genus Marinobacter were 10–27 %. Differential phenotypic properties, together with phylogenetic and genetic distinctiveness, revealed that strain HJM-18T is separated from recognized species of the genus Marinobacter. On the basis of the data presented, strain HJM-18T represents a novel species of the genus Marinobacter, for which the name Marinobacter confluentis sp. nov. is proposed. The type strain is HJM-18T ( = KCTC 42705T = NBRC 111223T).

Primorskyibacter insulae sp. nov., isolated from the junction between the ocean and a freshwater spring

A Gram-stain-negative, aerobic, non-spore-forming, non-flagellated and rod-shaped bacterial strain, designated SSK3-2T, was isolated from the locality where the ocean and a freshwater spring meet at Jeju island, South Korea, and subjected to a polyphasic taxonomic study. Strain SSK3-2T grew optimally at 30 °C, at pH 7.0–8.0 and in the presence of 2.0 % (w/v) NaCl. Neighbour-joining, maximum-likelihood and maximum-parsimony phylogenetic trees based on 16S rRNA gene sequences revealed that strain SSK3-2T clustered with the type strain of Primorskyibacter sedentarius, with which it exhibited 97.3 % sequence similarity. Strain SSK3-2T contained Q-10 as the predominant ubiquinone and C18 : 1ω7c as the major fatty acid. The major polar lipids detected in strain SSK3-2T were phosphatidylcholine, phosphatidylglycerol, one unidentified lipid and one unidentified aminolipid. The DNA G+C content of strain SSK3-2T was 60.6 mol% and its mean DNA–DNA relatedness value with P. sedentarius JCM 16874T was 19 %. Differential phenotypic properties, together with phylogenetic and genetic distinctiveness, revealed that strain SSK3-2T is separated from P. sedentarius. On the basis of the data presented, strain SSK3-2T is considered to represent a novel species of the genus Primorskyibacter, for which the name Primorskyibacter insulae sp. nov. is proposed. The type strain is SSK3-2T ( = KCTC 42602T = CECT 8871T).

Alteromonas confluentis sp. nov., isolated from the junction between the ocean and a freshwater spring

A Gram-stain-negative, aerobic, non-spore-forming, non-flagellated and coccoid, ovoid or rod-shaped bacterial strain, DSSK2-12T, was isolated from the place where the ocean and a freshwater spring meet at Jeju island, South Korea. Strain DSSK2-12T grew optimally at 30 °C, at pH 7.0–8.0 and in the presence of 2.0 % (w/v) NaCl. The neighbour-joining phylogenetic tree based on 16S rRNA gene sequences revealed that strain DSSK2-12T fell within the clade comprising the type strains of species of the genus Alteromonas. Strain DSSK2-12T exhibited 16S rRNA gene sequence similarity values of 97.2–98.1 % to the type strains of Alteromonas litorea, Alteromonas marina, Alteromonas hispanica and Alteromonas genovensis and of 95.39–96.98 % to those of other species of the genus Alteromonas. Strain DSSK2-12T contained Q-8 as the predominant ubiquinone and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), C16 : 0 and C18 : 1ω7c as the major fatty acids. The major polar lipids of strain DSSK2-12T were phosphatidylethanolamine, phosphatidylglycerol and one unidentified aminolipid. The DNA G+C content of strain DSSK2-12T was 48.6 mol% and its mean DNA–DNA relatedness values with the type strains of A. litorea, A. marina, A. hispanica and A. genovensis were 9–21 %. The differential phenotypic properties, together with phylogenetic and genetic distinctiveness, revealed that strain DSSK2-12T is separated from other species of the genus Alteromonas. On the basis of the data presented, strain DSSK2-12T is considered to represent a novel species of the genus Alteromonas, for which the name Alteromonas confluentis sp. nov. is proposed. The type strain is DSSK2-12T ( = KCTC 42603T = CECT 8870T).

Roseovarius scapharcae sp. nov., isolated from ark shell Scapharca broughtonii

A Gram-stain-negative, non-motile, aerobic and ovoid or rod-shaped bacterium, designated MA4-5T, was isolated from ark shell (Scapharca broughtonii) collected from the South Sea, South Korea. The novel strain grew optimally at 25 °C, at pH 7.0-8.0 and in the presence of 2.0 % (w/v) NaCl. Neighbour-joining and maximum-likelihood phylogenetic trees based on 16S rRNA gene sequences showed that strain MA4-5T forms a coherent cluster with the type strains of Roseovarius albus, Roseovarius aestuarii and Roseovarius nubinhibens, sharing 97.0-99.2 % sequence similarity. It exhibited 16S rRNA gene sequence similarity of 93.1-96.1 % to the type strains of other Roseovarius species. Strain MA4-5T contained Q-10 as the predominant ubiquinone and C18 : 1ω7c as the major fatty acid. The major polar lipids of strain MA4-5T were phosphatidylcholine, phosphatidylglycerol, one unidentified aminolipid and one unidentified lipid. The DNA G+C content of strain MA4-5T was 53.8 mol% and its mean DNA-DNA relatedness values with the type strains of R. albus, R. aestuarii and R. nubinhibens were 11-26 %. Differential phenotypic properties, together with phylogenetic and genetic distinctiveness, indicated that strain MA4-5T is separate from recognized species of the genus Roseovarius. On the basis of the data presented, strain MA4-5T is considered to represent a novel species of the genus Roseovarius, for which the name Roseovarius scapharcae sp. nov. is proposed. The type strain is MA4-5T ( = KCTC 42703T = NBRC 111226T).

Gramella aquimixticola sp. nov., isolated from water of an estuary environment

A Gram-stain-negative, aerobic, non-spore-forming bacterial strain, motile by gliding and with rod-shaped or ovoid cells, was isolated from water of an estuary environment at Hwajinpo, South Korea. The strain was designated HJM-19T and subjected to a polyphasic taxonomic study. The novel strain grew optimally at 30 °C, at pH 7.0-8.0 and in the presence of 1.0-2.0 % (w/v) NaCl. Phylogenetic trees based on 16S rRNA gene sequences revealed that strain HJM-19T belongs to the genus Gramella. It exhibited 16S rRNA gene sequence similarity values of 97.2-98.1 % to the type strains of Gramella portivictoriae, Gramella aestuariivivens, Gramella marina, Gramella echinicola and Gramella aestuarii, and of 93.9-96.5 % to the type strains of the other species of the genus Gramella with validly published names. Strain HJM-19T contained MK-6 as the predominant menaquinone and anteiso-C15 : 0, anteiso-C17 : 1ω9c and C17 : 0 2-OH as the major fatty acids. The major polar lipids of strain HJM-19T were phosphatidylethanolamine and two unidentified lipids. The DNA G+C content of strain HJM-19T was 48.0 mol%, and its DNA-DNA relatedness values with the type strains of the five phylogenetically closely related species of the genus Gramella were 11-23 %. The differential phenotypic properties, together with the phylogenetic and genetic distinctiveness, revealed that strain HJM-19T is separated from other species of the genus Gramella. On the basis of the data presented, strain HJM-19T is considered to represent a novel species of the genus Gramella, for which the name Gramella aquimixticola sp. nov. is proposed. The type strain is HJM-19T ( = KCTC 42706T = NBRC 111224T).

Pontivivens insulae gen. nov., sp. nov., isolated from seawater

A Gram-stain-negative, aerobic, non-motile and coccoid, ovoid or rod-shaped bacterial strain, designated GYSW-23T, was isolated from seawater off Geoje island in the South Sea, South Korea. Strain GYSW-23T grew optimally at 25 °C, at pH 7.0–8.0 and in the presence of approximately 2.0–3.0   % (w/v) NaCl. Phylogenetic trees based on 16S rRNA gene sequences revealed that strain GYSW-23T forms a distinct evolutionary lineage independent of other taxa of the family Rhodobacteraceae. It exhibited 16S rRNA gene sequence similarity values of 94.0, 93.5, 93.4 and 93.4 % to the type strains of Roseovarius aestuarii, Ruegeria marina, Roseovarius pacificus and Oceanicola litoreus, respectively, and 93.6 % to ‘Actibacterium atlanticum’ 22II-S11-z10. Strain GYSW-23T contained Q-10 as the predominant ubiquinone and C18  :  1ω7c as the major fatty acid. The major polar lipids of strain GYSW-23T were phosphatidylcholine, phosphatidylglycerol and one unidentified aminolipid. The fatty acid and polar lipid profiles of strain GYSW-23T were distinguishable from those of the phylogenetically related taxa. The DNA G+C content of strain GYSW-23T was 60.6 mol%. On the basis of the phylogenetic, chemotaxonomic and other phenotypic properties, strain GYSW-23T is considered to represent a novel species of a new genus in the family Rhodobacteraceae, for which the name Pontivivens insulae gen. nov., sp. nov. is proposed. The type strain of Pontivivens insulae is GYSW-23T ( = KCTC 42458T = CECT 8812T).

Maribacter confluentis sp. nov., isolated from the junction between the ocean and a freshwater spring

A Gram-stain-negative, aerobic, non-spore-forming, non-flagellated, non-gliding and rod-shaped bacterial strain, SSK2-2(T), was isolated from the place where the ocean and a freshwater spring meet at Jeju island, South Korea. Strain SSK2-2(T) grew optimally at 30 °C, at pH 7.0-8.0 and in the presence of 2.0-3.0% (w/v) NaCl. The neighbour-joining phylogenetic tree based on 16S rRNA gene sequences revealed that strain SSK2-2(T) fell within the clade comprising the type strains of species of the genus Maribacter, joining the type strain of Maribacter sedimenticola with which it shared 99.4% similarity. Sequence similarities to the type strains of other Maribacter species were 94.6-98.2%. Strain SSK2-2(T) contained MK-6 as the predominant menaquinone and iso-C17 : 0 3-OH, iso-C15 : 0, iso-C15 : 1 G, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and summed feature 9 (iso-C17 : 1ω9c and/or 10-methyl C16 : 0) as the major fatty acids. The major polar lipids of strain SSK2-2(T) were phosphatidylethanolamine and one unidentified lipid. The DNA G+C content of strain SSK2-2(T) was 38.2 mol% and mean levels of DNA-DNA relatedness with the type strains of four phylogenetically related species of the genus Maribacter were 11-24%. Differential phenotypic properties, together with phylogenetic and genetic distinctiveness, revealed that strain SSK2-2(T) is separate from other Maribacter species. On the basis of the data presented, strain SSK2-2(T) is considered to represent a novel species of the genus Maribacter, for which the name Maribacter confluentis sp. nov. is proposed. The type strain is SSK2-2(T) ( = KCTC 42604(T) = CECT 8869(T)).

Aliisedimentitalea scapharcae gen. nov., sp. nov., isolated from ark shell Scapharca broughtonii

A Gram-negative, aerobic, non-spore-forming, motile and ovoid or rod-shaped bacterial strain, designated MA2-16(T), was isolated from ark shell (Scapharca broughtonii) collected from the South Sea, South Korea. Strain MA2-16(T) was found to grow optimally at 30°C, at pH 7.0-8.0 and in the presence of 2.0% (w/v) NaCl. Neighbour-joining, maximum-likelihood and maximum-parsimony phylogenetic trees based on 16S rRNA gene sequences revealed that strain MA2-16(T) clustered with the type strain of Sedimentitalea nanhaiensis. The novel strain exhibited a 16S rRNA gene sequence similarity value of 97.1% to the type strain of S. nanhaiensis. In the neighbour-joining phylogenetic tree based on gyrB sequences, strain MA2-16(T) formed an evolutionary lineage independent of those of other taxa. Strain MA2-16(T) contained Q-10 as the predominant ubiquinone and C18:1 ω7c and 11-methyl C18:1 ω7c as the major fatty acids. The major polar lipids of strain MA2-16(T) were phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine, an unidentified aminolipid and an unidentified lipid. The DNA G+C content of strain MA2-16(T) was 57.7 mol% and its DNA-DNA relatedness values with the type strains of S. nanhaiensis and some phylogenetically related species of the genera Leisingera and Phaeobacter were 13-24%. On the basis of the data presented, strain MA2-16(T) is considered to represent a novel genus and novel species within the family Rhodobacteraceae, for which the name Aliisedimentitalea scapharcae gen. nov., sp. nov. is proposed. The type strain is MA2-16(T) (=KCTC 42119(T) =CECT 8598(T)).

Lacinutrix undariae sp. nov., isolated from a brown algae reservoir

A Gram-stain-negative, aerobic, non-flagellated, non-gliding and ovoid or rod-shaped bacterium, designated strain W-BA8T, was isolated from a brown algae reservoir on the South Sea, South Korea, and subjected to a polyphasic taxonomic approach. Strain W-BA8T grew optimally at 25 °C, at pH 7.0-7.5 and in the presence of 1.0-2.0% (w/v) NaCl. Neighbour-joining and maximum-parsimony phylogenetic trees based on 16S rRNA gene sequences showed that strain W-BA8T clustered with the type strains of species of the genus Lacinutrix. Strain W-BA8T exhibited 16S rRNA gene sequence similarity values of 94.9-96.5% to the type strains of Lacinutrix species and of less than 95.8% to the type strains of other recognized species. Strain W-BA8T contained MK-6 as the predominant menaquinone and iso-C15 : 0, iso-C15 : 1 G, iso-C15 : 0 3-OH and iso-C17 : 0 3-OH as major fatty acids. The polar lipid profile of strain W-BA8T contained phosphatidylethanolamine, two unidentified lipids and one unidentified glycolipid as major components. The DNA G+C content of strain W-BA8T was 35 mol%. Differential phenotypic properties, together with phylogenetic distinctiveness, revealed that strain W-BA8T is separated from other species of the genus Lacinutrix. On the basis of the data presented, strain W-BA8T is considered to represent a novel species of the genus Lacinutrix, for which the name Lacinutrix undariae sp. nov. is proposed. The type strain is W-BA8T ( = KCTC 42176T = CECT 8671T).

Aliiroseovarius pelagivivens gen. nov., sp. nov., isolated from seawater, and reclassification of three species of the genus Roseovarius as Aliiroseovarius crassostreae comb. nov., Aliiroseovarius halocynthiae comb. nov. and Aliiroseovarius sediminilitoris comb. nov

A Gram-stain-negative, non-motile, aerobic and ovoid or rod-shaped bacterium, designated GYSW-22T, was isolated from seawater off Geoje Island in the South Sea, South Korea. Strain GYSW-22T grew optimally at 25 °C, at pH 7.0–8.0 and in the presence of 1.0–2.0 % (w/v) NaCl. Neighbour-joining, maximum-likelihood and maximum-parsimony phylogenetic trees based on 16S rRNA gene sequences showed that strain GYSW-22T and the type strains of Roseovarius crassostreae, Roseovarius halocynthiae and Roseovarius sediminilitoris form a coherent cluster, independent of phylogenetic lineages or clusters comprising the type strains of other species of the genus Roseovarius. Strain GYSW-22T exhibited 16S rRNA gene sequence similarities of 97.2, 96.6 and 96.3 % to R. halocynthiae MA1-10T, R. crassostreae CV919-312T and R. sediminilitoris M-M10T, respectively, and of 92.6–94.7 % to the type strains of other species of the genus Roseovarius. Strain GYSW-22T contained Q-10 as the predominant ubiquinone and C18 : 1ω7c as the major fatty acid. The major polar lipids were phosphatidylcholine, phosphatidylglycerol, one unidentified aminolipid and one unidentified lipid. The DNA G+C content of strain GYSW-22T was 59.0 mol% and its mean DNA–DNA relatedness value with R. halocynthiae MA1-10T was 15 %. On the basis of the data presented, we propose strain GYSW-22T represents a novel species of a new genus, Aliiroseovarius pelagivivens gen. nov., sp. nov. The type strain of the type species is GYSW-22T ( = KCTC 42459T = CECT 8811T). In this study, it is also proposed that Roseovarius crassostreae, Roseovarius halocynthiae and Roseovarius sediminilitoris be reclassified into the new genus as Aliiroseovarius crassostreae comb. nov. (type strain CV919-312T = ATCC BAA-1102T = DSM 16950T), Aliiroseovarius halocynthiae comb. nov. (type strain MA1-10T = KCTC 23462T = CCUG 60745T) and Aliiroseovarius sediminilitoris comb. nov. (type strain M-M10T = KCTC 23959T = CCUG 62413T), respectively.

Lutibacter crassostreae sp. nov., isolated from oyster

A Gram-stain-negative, aerobic, non-spore-forming, non-flagellated, non-gliding and ovoid or rod-shaped bacterial strain, designated TYO-8T, was isolated from an oyster collected from the South Sea in South Korea. Strain TYO-8T grew optimally at 25 °C, at pH 7.0-8.0 and in the presence of 2.0-3.0% (w/v) NaCl. A neighbour-joining phylogenetic tree, based on 16S rRNA gene sequences, revealed that strain TYO-8T fell within the clade comprising the type strains of species of the genus Lutibacter, clustering coherently with the type strain of Lutibacter litoralis with a sequence similarity of 99.3%. Strain TYO-8T exhibited 16S rRNA gene sequence similarity values of 95.3-97.5% to the type strains of other species of the genus Lutibacter and of less than 92.9% to the type strains of other species with validly published names. Strain TYO-8T contained MK-6 as the predominant menaquinone and iso-C15 : 0, iso-C15 : 0 3-OH and iso-C15 : 1 G as the major fatty acids. The major polar lipids of strain TYO-8T were phosphatidylethanolamine and two unidentified lipids. The DNA G+C content of strain TYO-8T was 33.8 mol% and its DNA-DNA relatedness values with the type strains of L. litoralis, Lutibacter aestuarii and Lutibacter flavus were 13-27%. The differential phenotypic properties, together with the phylogenetic and genetic distinctiveness, revealed that strain TYO-8T is distinct from other species of the genus Lutibacter. On the basis of the data presented, strain TYO-8T is considered to represent a novel species of the genus Lutibacter, for which the name Lutibacter crassostreae sp. nov. is proposed. The type strain is TYO-8T ( = KCTC 42461T = NBRC 110923T).

Sphingomicrobium aestuariivivum sp. nov., isolated from a tidal flat

A Gram-stain-negative, aerobic, non-spore-forming, non-flagellated and coccoid, ovoid or rod-shaped bacterial strain, designated AH-M8T, was isolated from a tidal flat sediment collected from Aphae Island in the south-western sea, South Korea. Strain AH-M8T grew optimally at 35 °C, at pH 7.0-8.0 and in the presence of 2.0-3.0% (w/v) NaCl. A neighbour-joining phylogenetic tree based on 16S rRNA gene sequences revealed that strain AH-M8T belonged to the genus Sphingomicrobium, clustering with the type strain of Sphingomicrobium astaxanthinifaciens, with which it shared 99.0% 16S rRNA gene sequence similarity. Sequence similarities to the type strains of other species of the genus Sphingomicrobium were 95.4-96.0%. Strain AH-M8T contained Q-10 as the predominant ubiquinone and C18 : 1ω7c, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and C16 : 0 as the major fatty acids. The major polar lipids of strain AH-M8T were phosphatidylglycerol, phosphatidylethanolamine, sphingoglycolipid and one unidentified glycolipid. The major polyamine is triamine sym-homospermidine. The DNA G+C content of strain AH-M8T was 66.7 mol% and its mean DNA-DNA relatedness value with S. astaxanthinifaciens JCM 18551T was 21%. The differential phenotypic properties, together with the phylogenetic and genetic distinctiveness, revealed that strain AH-M8T is separated from other species of the genus Sphingomicrobium. On the basis of the data presented, strain AH-M8T is considered to represent a novel species of the genus Sphingomicrobium, for which the name Sphingomicrobium aestuariivivum sp. nov. is proposed. The type strain is AH-M8T ( = KCTC 42286T = NBRC 110678T).

Polaribacter undariae sp. nov., isolated from a brown alga reservoir

A Gram-stain-negative, non-flagellated, non-gliding, aerobic and rod-shaped or ovoid bacterial strain, designated W-BA7(T), was isolated from a brown alga reservoir on the South Sea in South Korea. This strain grew optimally at 25 °C, at pH 7.0-8.0 and in the presence of approximately 2.0% (w/v) NaCl. A neighbour-joining phylogenetic tree based on 16S rRNA gene sequences showed that strain W-BA7(T) belonged to the genus Polaribacter, clustering coherently with the type strain of Polaribacter sejongensis, showing 99.3% sequence similarity. Strain W-BA7(T) exhibited 16S rRNA gene sequence similarity of 93.4-98.6% to the type strains of the other species of the genus Polaribacter. Strain W-BA7(T) contained MK-6 as the predominant menaquinone and iso-C15 : 0 3-OH and anteiso-C15 : 0 as the major fatty acids. The major polar lipids of strain W-BA7(T) were phosphatidylethanolamine, three unidentified lipids, one unidentified glycolipid, one unidentified aminolipid and one unidentified aminophospholipid. The DNA G+C content of strain W-BA7(T) was 31.9 mol%, and the mean DNA-DNA relatedness with the type strains of four phylogenetically related species of the genus Polaribacter was 12-27%. Differential phenotypic properties, together with its phylogenetic and genetic distinctiveness, revealed that strain W-BA7(T) is separated from recognized species of the genus Polaribacter. On the basis of the data presented, strain W-BA7(T) is considered to represent a novel species of the genus Polaribacter, for which the name Polaribacter undariae sp. nov. is proposed. The type strain is W-BA7(T) ( =KCTC 42175(T) =CECT 8670(T)).

Sulfitobacter undariae sp. nov., isolated from a brown algae reservoir

A Gram-stain-negative, aerobic, non-spore-forming, non-flagellated and coccoid, ovoid or rod-shaped bacterial strain, W-BA2(T), was isolated from a brown algae reservoir in Wando of South Korea. Strain W-BA2(T) grew optimally at 25 °C, at pH 7.0-8.0 and in the presence of approximately 2.0-3.0% (w/v) NaCl. Phylogenetic trees based on 16S rRNA gene sequences revealed that strain W-BA2(T) fell within the clade comprising the type strains of species of the genus Sulfitobacter , clustering coherently with the type strains of Sulfitobacter donghicola and Sulfitobacter guttiformis showing sequence similarity values of 98.0-98.1%. Sequence similarities to the type strains of the other species of the genus Sulfitobacter were 96.0-97.4%. Strain W-BA2(T) contained Q-10 as the predominant ubiquinone and C18 : 1ω7c as the major fatty acid. The major polar lipids of strain W-BA2(T) were phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine, one unidentified aminolipid and one unidentified lipid. The DNA G+C content of strain W-BA2(T) was 55.0 mol% and its DNA-DNA relatedness values with the type strains of Sulfitobacter donghicola , Sulfitobacter guttiformis and Sulfitobacter mediterraneus were 16-23%. The differential phenotypic properties, together with the phylogenetic and genetic distinctiveness, revealed that strain W-BA2(T) is separated from other species of the genus Sulfitobacter . On the basis of the data presented, strain W-BA2(T) is considered to represent a novel species of the genus Sulfitobacter, for which the name Sulfitobacter undariae sp. nov. is proposed. The type strain is W-BA2(T) ( = KCTC 42200(T) = NBRC 110523(T)).

Gramella aestuariivivens sp. nov., isolated from a tidal flat

A Gram-stain-negative, aerobic, non-spore-forming, non-flagellated and rod-shaped or ovoid bacterial strain, designated BG-MY13T, was isolated from a tidal flat sediment on the South Sea, South Korea. Strain BG-MY13T grew optimally at 30–35 °C, at pH 7.0–8.0 and in the presence of 2.0–3.0 % (w/v) NaCl. Phylogenetic trees based on 16S rRNA gene sequences revealed that strain BG-MY13T falls within the cluster comprising the type strains of species of the genus Gramella . Strain BG-MY13T exhibited 16S rRNA gene sequ4ence similarity values of 96.9–97.8 % to the type strains of Gramella echinicola , Gramella gaetbulicola , Gramella portivictoriae and Gramella marina and of 94.6–96.5 % to the type strains of other species of the genus Gramella with validly published names. Strain BG-MY13T contained MK-6 as the predominant menaquinone and iso-C15 : 0 and iso-C17 : 0 3-OH as the major fatty acids. The major polar lipids were phosphatidylethanolamine and one unidentified lipid. The DNA G+C content of strain BG-MY13T was 38.9 mol% and DNA–DNA relatedness values with the type strains of G. echinicola , G. gaetbulicola , G. portivictoriae and G. marina were 12–23 %. The differential phenotypic properties, together with phylogenetic and genetic distinctiveness, revealed that strain BG-MY13T is separated from other species of the genus Gramella . On the basis of the data presented, strain BG-MY13T is considered to represent a novel species of the genus Gramella , for which the name Gramella aestuariivivens sp. nov. is proposed. The type strain is BG-MY13T ( = KCTC 42285T = NBRC 110677T).

Demequina activiva sp. nov., isolated from a tidal flat

A Gram-stain-positive, facultatively anaerobic, non-spore-forming, non-flagellated and rod-shaped or ovoid bacterial strain, designated BS-12M(T), was isolated from a tidal flat sediment on the South Sea, South Korea. Strain BS-12M(T) grew optimally at 35 °C, at pH 7.0-8.0 and in the presence of 2.0% (w/v) NaCl. The neighbour-joining phylogenetic tree based on 16S rRNA gene sequences revealed that strain BS-12M(T) fell within the cluster comprising the type strains of species of the genus Demequina, joining the type strain of Demequina aestuarii with which it shared the highest sequence similarity (98.6%). It exhibited 16S rRNA gene sequence similarity of 96.1-97.9% to the type strains of other species of the genus Demequina. The peptidoglycan type of strain BS-12M(T) was A4β based on L-Orn -L-Ser -D-Glu. Strain BS-12M(T) contained demethylmenaquinone-9(H4) as the major menaquinone and anteiso-C15:0 and C16:0 as the major fatty acids. The major polar lipids of strain BS-12M(T) were phosphatidylinositol and phosphatidylinositolmannoside. The DNA G+C content of strain BS-12M(T) was 70.7 mol% and its DNA-DNA relatedness values with the type strains of five phylogenetically related species of the genus Demequina were 15-34%. Differential phenotypic properties, together with phylogenetic and genetic distinctiveness, revealed that strain BS-12M(T) is separate from other species of the genus Demequina. On the basis of the data presented, strain BS-12M(T) is considered to represent a novel species of the genus Demequina, for which the name Demequina activiva sp. nov. is proposed. The type strain is BS-12M(T) ( =KCTC 29674(T) = NBRC 110675T).

Phaeobacter marinintestinus sp. nov., isolated from the intestine of a sea cucumber (Apostichopus japonicus)

A Gram-negative, strictly aerobic, non-motile, and rod-shaped bacterial strain designated UB-M7(T) was isolated from the intestine of a sea cucumber (Apostichopus japonicus) collected from Pohang in South Korea. Strain UB-M7(T) displayed optimal growth at 25 °C, pH 7.0-7.5, and with 2.0-3.0 % (w/v) NaCl. Phylogenetic analyses based on the 16S rRNA gene sequences showed that strain UB-M7(T) clustered with Phaeobacter arcticus DSM 23566(T), Phaeobacter inhibens DSM 16374(T), Phaeobacter gallaeciensis BS107(T), and Phaeobacter leonis 306(T), exhibiting 16S rRNA gene sequence similarity values of 96.8, 96.6, 96.4, and 96.2 %, respectively. Strain UB-M7(T) was found to exhibit the highest gyrB sequence similarity value of 80.6 % to the type strain of P. arcticus. The major respiratory quinone of strain UB-M7(T) was found to be ubiquinone 10 (Q-10). The major cellular fatty acids (>5 % of the total fatty acids) are summed features 8 (comprising C18:1 ω7c and/or C18:1 ω6c), 11-methyl C18:1 ω7c, and cyclo C19:0 ω8c. The DNA G+C content was found to be 58.5 mol% and DNA-DNA relatedness value with P. arcticus JCM 14644(T) was 17.2 ± 2.4 %. The major polar lipids of strain UB-M7(T) were identified as phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylcholine; one phospholipid, and three other lipids remain unidentified. Based on its phenotypic, phylogenetic, and chemotaxonomic properties it is concluded that strain UB-M7(T) represents a novel species in the genus Phaeobacter, for which the name Phaeobacter marinintestinus sp. nov. is proposed. The type strain is UB-M7(T) (=KCCM 43045(T) = JCM 19926(T)).

Litorivivens lipolytica gen. nov., sp. nov., a lipolytic bacterium isolated from a tidal flat

A Gram-stain-negative, flagellated, aerobic and rod-shaped or ovoid bacterial strain, designated HJTF-7(T), was isolated from a tidal flat on the South Sea of South Korea, and its taxonomic position was investigated using a polyphasic approach. Strain HJTF-7(T) grew optimally at 25 °C, at pH 7.0-8.0 and in the presence of 2.0% (w/v) NaCl. Neighbour-joining, maximum-likelihood and maximum-parsimony phylogenetic trees, based on 16S rRNA gene sequences, showed that strain HJTF-7(T) joined the cluster comprising the type strains of species of the genera Spongiibacter and Zhongshania. Strain HJTF-7(T) exhibited 16S rRNA gene sequence similarities of 90.4-92.5% to the type strains of species of the genera Spongiibacter and Zhongshania and of less than 91.5% to the type strains of other recognized species. Strain HJTF-7(T) contained Q-8 as the predominant ubiquinone. The major fatty acids were iso-C17:1ω9c, iso-C15:0, iso-C17:0, iso-C11:0 3-OH and C17:1ω8c and the major polar lipids were phosphatidylethanolamine and phosphatidylglycerol. The fatty acid and polar lipid profiles of strain HJTF-7(T) were distinct from those of members of the genera Spongiibacter and Zhongshania. The DNA G+C content of strain HJTF-7(T) was 55.9 mol%. The phylogenetic data and differential chemotaxonomic and other phenotypic properties revealed that strain HJTF-7(T) represents a novel genus and species within the class Gammaproteobacteria, for which the name Litorivivens lipolytica gen. nov., sp. nov. is proposed. The type strain of Litorivivens lipolytica is HJTF-7(T) ( =KCTC 42157(T) =CECT 8654(T)).

Cribrihabitans neustonicus sp. nov., isolated from coastal surface seawater, and emended description of the genus Cribrihabitans Chen et al. 2014

A Gram-stain-negative, strictly aerobic, rod- or oval-shaped, motile, non-spore-forming bacterium, designated strain CC-AMHB-3(T), was isolated from coastal surface seawater off Hualien, Taiwan. The novel strain showed high pairwise 16S rRNA gene sequence similarities to Ruegeria mobilis NBRC 101030(T) (96.5%), Ruegeria scottomollicae LMG 24367(T) (96.4%), Phaeobacter aquaemixtae SSK6-1(T) (96.2%), Phaeobacter daeponensis TF-218(T) (96.2%), Cribrihabitans marinus CZ-AM5(T) (96.1%) and other species of the family Rhodobacteraceae (≤ 95.9%). However, strain CC-AMHB-3(T) formed a distinct phyletic lineage associated with C. marinus CZ-AM5(T) during phylogenetic analyses. The polar lipid profile of strain CC-AMHB-3(T) included major amounts of diphosphatidylglycerol, phosphatidylglycerol and phosphatidylcholine; moderate amounts of phosphatidylethanolamine, an unidentified aminolipid, an unidentified phospholipid and an unidentified lipid; and trace amounts of an unidentified lipid and an unidentified phospholipid, which was qualitatively almost in line with that of C. marinus CZ-AM5(T) but remarkably distinct as compared with the type species of the genera Ruegeria (Ruegeria atlantica JCM 21234(T)) and Phaeobacter (Phaeobacter gallaeciensis JCM 21319(T)). In line with the fatty acid profile of C. marinus CZ-AM5(T), the major (>5% of total) fatty acids of strain CC-AMHB-3(T) were C(18:1)ω7c and/or C(18:1)ω6c (summed feature 8), 11-methyl C(18:1)ω7c and C(16:0). The DNA G+C content was 66.7 mol%. Ubiquinone-10 (Q-10) was the sole respiratory quinone. Thus, based on the results of the polyphasic study presented here, strain CC-AMHB-3(T) is considered to represent a novel species of the genus Cribrihabitans, for which the name Cribrihabitans neustonicus sp. nov. is proposed; the type strain is CC-AMHB-3(T) ( = JCM 19537(T) =BCRC 80695(T)). In addition, an emended description of the genus Cribrihabitans is also proposed.

Genome-scale data suggest reclassifications in the Leisingera-Phaeobacter cluster including proposals for Sedimentitalea gen. nov. and Pseudophaeobacter gen. nov

Earlier phylogenetic analyses of the marine Rhodobacteraceae (class Alphaproteobacteria) genera Leisingera and Phaeobacter indicated that neither genus might be monophyletic. We here used phylogenetic reconstruction from genome-scale data, MALDI-TOF mass-spectrometry analysis and a re-assessment of the phenotypic data from the literature to settle this matter, aiming at a reclassification of the two genera. Neither Phaeobacter nor Leisingera formed a clade in any of the phylogenetic analyses conducted. Rather, smaller monophyletic assemblages emerged, which were phenotypically more homogeneous, too. We thus propose the reclassification of Leisingera nanhaiensis as the type species of a new genus as Sedimentitalea nanhaiensis gen. nov., comb. nov., the reclassification of Phaeobacter arcticus and Phaeobacter leonis as Pseudophaeobacter arcticus gen. nov., comb. nov. and Pseudophaeobacter leonis comb. nov., and the reclassification of Phaeobacter aquaemixtae, Phaeobacter caeruleus, and Phaeobacter daeponensis as Leisingera aquaemixtae comb. nov., Leisingera caerulea comb. nov., and Leisingera daeponensis comb. nov. The genera Phaeobacter and Leisingera are accordingly emended.