Paraneptunicella aestuarii gen. nov., sp. nov., a member of the family Alteromonadaceae isolated from seawater in East China Sea.

An aerobic Gram-stain-negative, curved rod-shaped and non-spore-forming bacterial strain (NBU2194T) was isolated from seawater collected in an intertidal zone in Ningbo, Zhejiang Province, PR China. It was motile though a single polar flagellum and grew at 20-42 °C (optimum, 30 °C), in 0-2.0 % NaCl (0 %, w/v) and at pH 5.0-9.0 (pH 6.0-7.0). The sole respiratory quinone was ubiquinone-8. The major cellular fatty acids were C16 : 0, C16 : 1 ω7c and/or C16 : 1 ω6c. The polar lipids contained diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, one unidentified phospholipid and two unidentified aminophosphoglycolipids. A phylogenetic analysis based on 16S rRNA gene sequences and 65 genomic core genes showed that strain NBU2194T formed a distinct lineage in the family Alteromonadaceae. The genome of strain NBU2194T was 4 913 533 bp with a DNA G+C content of 43.9 mol% and coded 3895 genes, 12 rRNA genes and 47 tRNA genes. The average nucleotide identity, amino acid identity and digital DNA-DNA hybridization values between strain NBU2194T and related species of Alteromonadaceae were below the threshold limit for prokaryotic species delineation. NBU2194T could be distinguished from other genera in the family Alteromonadaceae based on phenotypic, chemotaxonomic and genomic characteristics. On the basis of the polyphasic taxonomic evidence collected in this study, strain NBU2194T is considered to represent a novel genus and species in the family Alteromonadaceae, for which the name Paraneptunicella aestuarii is proposed. The type strain is NBU2194T (=KCTC 82442T=GDMCC 1.2217T).

Saccharobesus litoralis gen. nov., sp. nov., a novel alginate-degrading bacterium isolated from the surface of intertidal algal turf.

A novel rod-shaped, Gram-stain-negative, strictly aerobic and alginate-degrading marine bacterium, designated CCB-QB4T, was isolated from a surface of algal turf collected from a coastal area of Penang, Malaysia. The cells showed motility by a lateral flagellum. The rod-shaped cells formed long chains end-to-end. Phylogenetic analysis based on the 16S rRNA gene sequence of strain CCB-QB4T showed 94.07, 92.69, 91.52 and 90.90 % sequence similarity to Algibacillus agarilyticus RQJ05T, Catenovulum maritimum Q1T, Catenovulum agarivorans YM01T and Catenovulum sediminis D2T, respectively. Strain CCB-QB4T formed a cluster with A. agarilyticus RQJ05T. Strain CCB-QB4T was catalase-negative, oxidase-positive, and degraded agar, alginate, and starch. Cell growth was observed at 15-40 °C, at pH 7.0-10.0 and in the presence of 1-6 % (w/v) NaCl and glucose. The major fatty acids were summed feature 3 (C16 : 1 ω7c/iso-C15 : 0 2-OH), C16 : 0 and C18 : 1 ω7c. The polar lipids were phosphatidylethanolamine, two unidentified aminolipids, two unidentified glycolipids, an unidentified phospholipid and unidentified lipid. The major respiratory quinone was ubiquinone-8. The genomic DNA G+C content was 46.7 mol%. Based on the phenotypic, chemotaxonomic and phylogenetic data, strain CCB-BQ4T represents a novel species in a new genus, for which the name Saccharobesus litoralis gen. nov., sp. nov. is proposed. The type strain is CCB-QB4T (=JCM 33513T=CCB-MBL 5008T).

Bowmanella yangjiangensis sp. nov. and Amphritea pacifica sp. nov., isolated from mariculture fishponds in China.

Four Gram-stain-negative, catalase- and oxidase-positive, rod-shaped and motile strains (Y26, Y57T, ZJ14WT and RP18W) were isolated from mariculture fishponds in PR China. Comparisons based on 16S rRNA gene sequences showed that strains Y26 and Y57T share 16S rRNA gene sequence similarities in the range of 95.1-98.5 % with species of the genus Bowmanella, and strains ZJ14WT and RP18W share 16S rRNA gene sequence similarities in the range of 96.7 -98.8 % with species of the genus Amphritea, respectively. The genome sizes of strains Y26, Y57T, ZJ14WT and RP18W were about 4.85, 5.40, 4.70 and 4.70 Mbp with 49.5, 51.7, 51.2 and 51.3 mol% G+C content, respectively. The calculated pairwise OrthoANIu values among strains Y26, Y57T and species of the genus Bowmanella were in the range of 72.6-83.1 %, but the value between strains Y26 and Y57T was 96.2 %. The pairwise OrthoANIu values among strains ZJ14WT, RP18W and other species of the genus Amphritea were all less than 93.9 %, but the value between strains ZJ14WT and RP18W was 99.3 %. Q-8 was the major respiratory quinone of strains Y26, Y57T, ZJ14WT and RP18W, and the major fatty acids of these strains were all C16 : 1 ω7c, C16 : 0 and C18 : 1 ω7c. The predominant polar lipids of strains Y26 and Y57T included phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and phosphatidylinositol, but strains ZJ14WT and RP18W only contained phosphatidylethanolamine and phosphatidylglycerol. Combining phenotypic, biochemical and genotypic characteristics, strains Y26 and Y57T should belong to the same species and represent a novel member of the genus Bowmanella, and strains ZJ14WT and RP18W should belong to the same species and represent a novel member of the genus Amphritea, for which the names Bowmanella yangjiangensis sp. nov. (type strain Y57T=GDMCC 1.2180T=KCTC 82439T) and Amphritea pacifica sp. nov. (type strain ZJ14WT=GDMCC 1.2203T=KCTC 82438T) are proposed.

Expansion segments in bacterial and archaeal 5S ribosomal RNAs.

The large ribosomal RNAs of eukaryotes frequently contain expansion sequences that add to the size of the rRNAs but do not affect their overall structural layout and are compatible with major ribosomal function as an mRNA translation machine. The expansion of prokaryotic ribosomal RNAs is much less explored. In order to obtain more insight into the structural variability of these conserved molecules, we herein report the results of a comprehensive search for the expansion sequences in prokaryotic 5S rRNAs. Overall, 89 expanded 5S rRNAs of 15 structural types were identified in 15 archaeal and 36 bacterial genomes. Expansion segments ranging in length from 13 to 109 residues were found to be distributed among 17 insertion sites. The strains harboring the expanded 5S rRNAs belong to the bacterial orders Clostridiales, Halanaerobiales, Thermoanaerobacterales, and Alteromonadales as well as the archael order Halobacterales When several copies of a 5S rRNA gene are present in a genome, the expanded versions may coexist with normal 5S rRNA genes. The insertion sequences are typically capable of forming extended helices, which do not seemingly interfere with folding of the conserved core. The expanded 5S rRNAs have largely been overlooked in 5S rRNA databases.

Formation of cadmium sulfide nanoparticles mediates cadmium resistance and light utilization of the deep-sea bacterium Idiomarina sp. OT37-5b.

Heavy metal is one of the major factors threatening the survival of microorganisms. Here, a deep-sea bacterium designated Idiomarina sp. OT37-5b possessing strong cadmium (Cd) tolerance was isolated from a typical hydrothermal vent. Both the Cd-resistance and removal efficiency of Idiomarina sp. OT37-5b were significantly promoted by the supplement of cysteine and meanwhile large amount of CdS nanoparticles were observed. Production of H2 S from cysteine catalysed by methionine gamma-lyase was further demonstrated to contribute to the formation of CdS nanoparticles. Proteomic results showed the addition of cysteine effectively enhanced the efflux of Cd, improved the activities of reactive oxygen species scavenging enzymes, and thereby boosted the nitrogen reduction and energy production of Idiomarina sp. OT37-5b. Notably, the existence of CdS nanoparticles obviously promoted the growth of Idiomarina sp. OT37-5b when exposed to light, indicating this bacterium might grab light energy through CdS nanoparticles. Proteomic analysis revealed the expression levels of essential components for light utilization including electron transport, cytochrome complex and F-type ATPase were significantly up-regulated, which strongly suggested the formation of CdS nanoparticles promoted light utilization and energy production. Our results provide a good model to investigate the uncovered mechanisms of self-photosensitization of nonphotosynthetic bacteria for light-to-chemical production in the deep biosphere.

Pseudidiomarina piscicola sp. nov., isolated from cultured European seabass, Dicenthrarchus labrax.

Strain CECT 9734 T, a Gram-negative, aerobic, chemoorganotrophic bacterium, motile by polar flagella, was isolated from cultured European seabass, Dicenthrarchus labrax, in Spain. It grows from 5 to 42 ºC, 6-9 pH and 1-12% total salinity. Major cellular fatty acids are C15:0 iso, summed feature 9 (C17:1 iso w9c/C16:0 10-methyl) and C17:0 iso. The genome size is 2.5 Mbp and G + C content is 49.5 mol%. Comparative analysis of the 16S rRNA gene sequence shows that the strain is a member of Pseudidiomarina, with highest similarities with Pseudidiomarina halophila (97.0%) and Pseudidiomarina salinarum (96.9%). Phylogenomic tree based on UBCG program shows P. halophila as its closest relative. ANI and in-silico DDH with other Pseudidiomarina spp. are lower than 87 and 20%, respectively, suggesting that strain CECT 9734 T represents a new species, for which we propose the name Pseudidiomarina piscicola sp. nov. and CECT 9734 T (= LUBLD50 7aT = LMG 31044 T) as type strain.

Algibacillus agarilyticus gen. nov., sp. nov., isolated from the surface of the red algae Gelidium amansii.

A novel Gram-stain-negative, strictly aerobic, coccoid and agar-hydrolysing bacterium, designated RQJ05T, was isolated from the marine red algae Gelidium amansii collected from the coastal area of Rizhao, PR China. Cells of strain RQJ05T were approximately 0.8-1.0×1.3-3.0 µm in size and motile by means of a polar flagellum. Growth occurred at 4-33 °C (optimum, 25-30 °C), pH 7.0-8.5 (optimum, pH 7.5-8.0) and in the presence of 1.0-7.0 % (w/v) NaCl (optimum, 2.0-3.0 %). Strain RQJ05T showed oxidase-positive and catalase-negative activities. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain RQJ05T formed a phylogenetic lineage with members of the family Alteromonadaceae and exhibited 16S rRNA gene sequence similarities of 92.6, 91.3, 90.2 and 90.1 % to Catenovulum maritimum Q1T, Catenovulum agarivorans YM01T, Paraphotobacterium marinum NSCS20N07DT and Algicola sagamiensis B-10-31T, respectively. The major cellular fatty acids of strain RQJ05T 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 major polar lipids of strain RQJ05T were phosphatidylethanolamine, phosphatidylglycerol and two aminophospholipids. Strain RQJ05T contained Q-8 as the major respiratory quinone. The genomic DNA G+C content was 39.0 mol%. On the basis of genotypic, phenotypic and phylogenetic evidence, strain RQJ05T is presented as a representative of a novel species in a new genus, for which the name Algibacillus agarilyticus gen. nov., sp. nov. is proposed. The type strain is RQJ05T (=KCTC 62846T=MCCC 1H00352T).

Distinctive gene and protein characteristics of extremely piezophilic Colwellia.

BACKGROUND: The deep ocean is characterized by low temperatures, high hydrostatic pressures, and low concentrations of organic matter. While these conditions likely select for distinct genomic characteristics within prokaryotes, the attributes facilitating adaptation to the deep ocean are relatively unexplored. In this study, we compared the genomes of seven strains within the genus Colwellia, including some of the most piezophilic microbes known, to identify genomic features that enable life in the deep sea. RESULTS: Significant differences were found to exist between piezophilic and non-piezophilic strains of Colwellia. Piezophilic Colwellia have a more basic and hydrophobic proteome. The piezophilic abyssal and hadal isolates have more genes involved in replication/recombination/repair, cell wall/membrane biogenesis, and cell motility. The characteristics of respiration, pilus generation, and membrane fluidity adjustment vary between the strains, with operons for a nuo dehydrogenase and a tad pilus only present in the piezophiles. In contrast, the piezosensitive members are unique in having the capacity for dissimilatory nitrite and TMAO reduction. A number of genes exist only within deep-sea adapted species, such as those encoding d-alanine-d-alanine ligase for peptidoglycan formation, alanine dehydrogenase for NADH/NAD+ homeostasis, and a SAM methyltransferase for tRNA modification. Many of these piezophile-specific genes are in variable regions of the genome near genomic islands, transposases, and toxin-antitoxin systems. CONCLUSIONS: We identified a number of adaptations that may facilitate deep-sea radiation in members of the genus Colwellia, as well as in other piezophilic bacteria. An enrichment in more basic and hydrophobic amino acids could help piezophiles stabilize and limit water intrusion into proteins as a result of high pressure. Variations in genes associated with the membrane, including those involved in unsaturated fatty acid production and respiration, indicate that membrane-based adaptations are critical for coping with high pressure. The presence of many piezophile-specific genes near genomic islands highlights that adaptation to the deep ocean may be facilitated by horizontal gene transfer through transposases or other mobile elements. Some of these genes are amenable to further study in genetically tractable piezophilic and piezotolerant deep-sea microorganisms.

Paraglaciecola marina sp. nov., isolated from marine alga (Sargassum natans (L.) Gaillon).

A novel Gram-stain-negative, straight or curved rod-shaped, non-spore-forming, strictly aerobic, motile bacterium with a single polar flagellum, designated D3211T, was isolated from marine alga collected at the seashore of Yantai, PR China. The organism grew optimally at 24 °C, pH 7.0 and in the presence of 2.0 % (w/v) NaCl. Strain D3211T contained ubiquinone 8 as the major respiratory quinone and C16 : 1 ω7c and/or C16 : 1 ω6c, C16 : 0, iso-C17 : 0 and anteiso-C17 : 1 B and/or iso-C17 : 1 I as the major fatty acids. The predominant polar lipids of strain D3211T were phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. The DNA G+C content of strain D3211T was 39.4 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that the novel strain was related most closely to Paraglaciecola arctica BSs20135T, Paraglaciecola aestuariivivens JDTF-33T, Paraglaciecola aquimarina KCTC 32108T, Paraglaciecola mesophila DSM 15026T, Paraglaciecola psychrophila JCM 13954T and Paraglaciecola polaris ARK 150T with 97.6, 97.6, 97.5, 97.4, 97.3 and 97.1 % sequence similarities, respectively. Calculated average nucleotide identity and DNA-DNAhybridization values between strain D3211T and its phylogenetically related Paraglaciecola species were in the range 70.2-73.4 % and 19.1-20.4 %, respectively. On the basis of polyphasic analyses, strain D3211T represents a novel species of the genus Paraglaciecola, for which the name Paraglaciecola marina sp. nov. is proposed. The type strain is D3211T (=KCTC 72122T=MCCC 1K03603T).

Ningiella ruwaisensis gen. nov., sp. nov., a member of the family Alteromonadaceae isolated from marine water of the Arabian Gulf.

Strain B66T was isolated from a marine water sample collected at Al Ruwais, located on the northern tip of Qatar. Cells were Gram-stain-negative, strictly aerobic and short- rod-shaped with a polar flagellum. The isolate was able to grow at 15-45 °C (optimum, 30 °C), at pH 5-11 (optimum, pH 6.5-8) and with 0-6 % NaCl. 16S rRNA gene sequence analysis revealed that strain B66T was affiliated with the family Alteromonadaceae, sharing the highest sequence similarities to the genera Alteromonas (93.7-95.4 %), Aestuariibacter (94.0-95.1 %), Agaribacter (93.3-93.7 %), Glaciecola (92.0-93.7 %), Marisendiminitalea (93.2-93.3 %) and Planctobacterium (92.9 %). In the phylogenetic trees, strain B66T demonstrated the novel organism formed a distinct lineage closely associated with Aestuariibacter and Planctobacterium. Major fatty acids were C16 : 0, summed feature 3 (C16 : 1 ω7c/C16 : 1 ω6c/iso-C15 : 0 2-OH and iso-C15 : 0 3-OH. The major respiratory quinone was ubiquinone-8 and the major polar lipids are phosphatidylglycerol and phosphatidylethanolamine. The DNA G+C content derived from the genome was 43.2 mol%. Based on the phenotypic, chemotaxonomic, phylogenetic and genomic data, strain B66T is considered to represent a novel species and genus for which the name Ningiella ruwaisensis gen. nov., sp. nov., is proposed. The type strain is B66T (=QCC B003/17T=LMG 30288 T=CCUG 70703T).

Salinimonas iocasae sp. nov., a halophilic bacterium isolated from a polychaete tube in a hydrothermal field.

A moderately halophilic bacterium, designated strain KX18D6T, was isolated from the tube of the polychaete Paralvinella hessleri collected from a hydrothermal field located in the Okinawa Trough. Strain KX18D6T was Gram-stain-negative, rod-shaped, facultatively anaerobic, motile, oxidase- and catalase-positive, and grew optimally at 30-35 °C, pH 7.0 and in the presence of 3-5 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain KX18D6T grouped with the members of the genus Salinimonas, including Salinimonas chungwhensis BH030046T (97.7 % sequence similarity), Salinimonas lutimaris DPSR-4T (97.2 %) and Salinimonas sediminis N102T (96.4 %). Genome sequencing of strain KX18D6T revealed a genome size of 4.16 Mb and a DNA G+C content of 47.3 mol%. Genomic average nucleotide identity (orthoANI) values of strain KX18D6T with S. chungwhensis DSM 16280T, S. lutimaris KCTC 23464T and S. sediminis N102T were 76.2, 73.1 and 73.2 %, respectively, while the in silico DNA-DNA hybridization (GGDC) values for strain KX18D6T with these strains were 25.3, 17.7 and 18.0 %, respectively. The major fatty acids were summed feature 3 (C16 : 1 ω7c/C16 : 1 ω6c), C16 : 0 and summed feature 8 (C18 : 1 ω7c/C18 : 1 ω6c). The predominant respiratory quinone was ubiquinone 8, and the predominant polar lipids were phosphatidylethanolamine and phosphatidylglycerol. On the basis of comparative analysis of phylogenetic, phylogenomic, phenotypic and chemotaxonomic characteristics, strain KX18D6T (=KCTC 72464T=MCCC 1K03884T) is clearly distinguishable from the type strains of species of the genus Salinimonas and is considered to represent a novel species of the genus Salinimonas, for which the name Salinimonas iocasae sp. nov. is proposed.

Whole genome analysis calls for a taxonomic rearrangement of the genus Colwellia.

Microbial taxonomy is the foundation of microbiology and rapid advancements in DNA sequencing technologies are providing new approaches to address prevailing questions in this field. The family Colwelliaceae, which currently comprises four genera, is a diverse and globally abundant group of Gamaproteobacteria. Based on 14 publically available genomes of bacteria strains labeled as members of the family Colwelliaceae, phylogenomic analyses were conducted to revisiting the taxonomic status of this family both in the genus and species level. Using genome-based phylogeny as a primary guideline and genome-based similarity indexes including average amino acid identity, percentage of conserved proteins, average nucleotide identity, and the digital DNA-DNA hybridization as supplements, the following taxonomic proposals were proposed: Colwellia polaris, Colwellia beringensis, Colwellia sediminilitoris, Colwellia aestuarii, Colwellia chukchiensis and Colwellia mytili should be reclassified into the novel genus Cognaticolwellia; Colwellia agarivorans should be reclassified into the novel genus Pseudocolwellia. Our results constitute a solid framework for current and future taxonomic decisions within this family, which will be helpful for avoiding confusion with ecological and evolutionary interpretations in subsequent studies.

Microbulbifer harenosus sp. nov., an alginate-degrading bacterium isolated from coastal sand.

A Gram-stain-negative, aerobic, rod-shaped bacterium with peritrichous flagella, designated strain HB161719T, was isolated from coastal sand collected from Tanmen Port in Hainan, PR China. The isolate was found to grow with 2-11 % (w/v) NaCl, at 15-45 °C and pH 6.0-10.0, with an optima of 2-3 % NaCl, 37 °C and pH 7.0, respectively. Chemotaxonomic analysis showed that Q-8 was detected as the sole respiratory quinone and that iso-C15 : 0 and summed features 3, 8 and 9 were the major cellular fatty acids. The G+C content of the genomic DNA was 58.2 mol%. Analysis of the 16S rRNA gene sequence of the strain showed an affiliation with the genus Microbulbifer, sharing 98.7, 98.4, 97.8 and 97.8 % sequence similarities to the closest relatives of Microbulbifer okinawensis ABABA23T, Microbulbifer pacificus SPO729T, Microbulbifer taiwanensis CC-LN1-12T and Microbulbifer gwangyangensis GY2T, respectively. Low DNA-DNA hybridization values showed that it formed a distinct genomic species. The combined phenotypic and molecular features supported that strain HB161719T represents a novel species of the genus Microbulbifer, for which the name Microbulbifer harenosus sp. nov. is proposed. The type strain is HB161719T (=CGMCC 1.13584T=JCM 32688T).

Marinomonas agarivorans sp. nov., an agar-degrading marine bacterium isolated from red algae.

A Gram-stain-negative, aerobic and curved-rod-shaped bacterium, designated QM202T, was isolated from red algae (Gracilaria blodgettii). Cells of strain QM202T were 0.2-0.3 µm wide and 1.0-2.5 µm long, catalase-negative and oxidase-positive. The strain exhibited an agar-degrading activity. It was motile by means of a single polar flagellum. Optimal growth occurred at 28-30 °C, pH 7.0-7.5 and in the presence of 2.0-3.0 % (w/v) NaCl. The DNA G+C content was 41.4 mol%. The isoprenoid quinone was identified as Q-8. Phophatidylethanolamine and phosphatidylglycerol were the predominant phospholipids. The dominant fatty acids were C18:1ω7c, C16:0 and C16:1ω7c and/or iso-C15:0 2-OH. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain QM202T belonged to the genus Marinomonas. The closest described neighbour in terms of 16S rRNA gene sequence identity was Marinomonas blandensis MED121T (95.5 %). The differential phenotypic properties, together with the phylogenetic and genetic distinctiveness indicated that strain QM202T can be considered to represent a novel species, Marinomonas agarivorans sp. nov. The type strain is QM202T (=KCTC 52475T=MCCC 1H00145T).

Litorilituus lipolyticus sp. nov., isolated from intertidal sand of the Yellow Sea in China, and emended description of Colwellia asteriadis.

A Gram-stain negative, rod-shaped, aerobic, oxidase-positive and catalase-weakly positive bacterial strain with polar or subpolar flagellum, designated RZ04T, was isolated from an intertidal sand sample collected from a coastal area of the Yellow Sea, China. The organism was observed to grow optimally at 25 °C and pH 6.5-7.0 with 2% (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain RZ04T was closely related to Colwellia asteriadis (similarity 96.9%) and Litorilituus sediminis (similarity 96.8%), and 94.4-96.4% sequence similarities to other type strains of species of the genera belonged to the family Colwelliaceae. The dominant fatty acids of strain RZ04T were determined to be C17:1ω8c, C15:1ω8c, C16:0 and summed feature 3 (C16:1ω6c and/or C16:1ω7c), and the predominant isoprenoid quinone was determined to be quinone 8 (Q-8). Phosphatidylethanolamine, phosphatidylglycerol, an unidentified aminophospholipid and four unidentified lipids were determined to be the major constituents of the polar lipids. The genome of strain RZ04T is 4.14 Mbp with a G + C content of 37.4 mol%. A total of 3631 genes are predicted, with 3531 protein-coding genes, 75 RNA genes and 25 pseudogenes. Based on phenotypic, genotypic and phylogenetic analysis, strain RZ04T is considered to represent a novel species in the genus Litorilituus, for which the name Litorilituus lipolyticus is proposed. The type strain is RZ04T (= MCCC 1K03616T = KCTC 62835T). An emended description of Colwellia asteriadis is also provided.

Pseudidiomarina gelatinasegens sp. nov., isolated from surface sediment of the Terra Nova Bay, Antarctica.

Polyphasic taxonomic analysis was performed to characterize a novel bacterium, which was isolated from surface sediment of the Terra Nova Bay, Antarctica, and designated as R04H25T. The cells of the isolate were Gram-stain-negative, aerobic, non-motile, slightly curved rods. Growth occurred at 4-42 °C, pH 7.0-9.5, and in 1-15 % (w/v) NaCl. Phylogenetic trees based on 16S rRNA gene sequences indicated that strain R04H25T formed an independent lineage within the genus Pseudidiomarina and its nearest neighbours were Pseudidiomarina donghaiensis 908033T (98.2 %), Pseudidiomarina marina PIM1T (98.1 %), Pseudidiomarina woesei W11T (97.8 %), Pseudidiomarina maritima 908087T (97.1 %) and Pseudidiomarina tainanensis PIN1T (97.0 %). The average nucleotide identities between strain R04H25T and the nearest neighbours were 76.2-77.7 %. The major fatty acids were iso-C17 : 0, summed feature 9, iso-C15 : 0, C16 : 0 and iso-C11 : 0 3-OH. The polar lipids comprised phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, an unidentified aminophospholipid, three unidentified glycolipids and two unidentified lipids. The predominant respiratory quinone was ubiquinone 8. The genomic DNA G+C content was 48.2 mol%. On the basis of the phylogenetic, physiological and chemotaxonomic results, we propose a novel species named as Pseudidiomarina gelatinasegens sp. nov. in the genus Pseudidiomarina, with the type strain R04H25T (=GDMCC 1.1503T=KCTC 62911T).

Marisediminitalea mangrovi gen. nov., sp. nov., isolated from marine mangrove sediment, and reclassification of Aestuariibacter aggregatus as Marisediminitalea aggregata comb. nov.

Strain GS-14T was isolated from a mangrove sediment sample collected at Beilun Estuary National Nature Reserve, Guangxi Province, PR China. Cells were Gram-stain-negative, strictly aerobic and rod-shaped with a polar flagellum. Optimal growth occurred in the presence of 3-6 % (w/v) NaCl, at pH 6-8 and at a temperature of 37 °C. The predominant polar lipids were phosphatidylglycerol and phosphatidylethanolamine. Ubiquinone 8 (Q-8) was the sole respiratory quinone. The major fatty acids (>10 % of the total fatty acids) were summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and C16 : 0. The DNA G+C content was 47.6 mol%. Phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain GS-14T had the highest sequence similarity to Aestuariibacter aggregatus WH169T (96.63 %), Aliiglaciecola coringensis AK49T (96.56 %) and Alteromonas lipolytica JW12T (96.22 %). In addition, the OrthoANIu value and dDDH values calculated from the genomes of strain GS-14T and A. aggregatus WH169T were 79.5 and 21.9 %, respectively. Based on the polyphasic taxonomic results, strain GS-14T is considered to represent a novel species in a new genus, for which the name Marisediminitalea mangrovi gen. nov., sp. nov. is proposed. The type strain of Marisediminitalea mangrovi is GS-14T (=KCTC 72401T=MCCC 1K03622T). Because Aestuariibacter aggregatus WH169T clustered with strain GS-14T in the phylogenetic trees and was clearly separated from the two species within the genus Aestuariibacter, it is reclassified as a member of the genus Marisediminitalea as Marisediminitalea aggregata comb. nov. (type strain WH169T=CGMCC 1.8995T=LMG 25283T). The type species of the genus Marisediminitalea is Marisediminitalea aggregata gen. nov., comb. nov.

Saliniradius amylolyticus gen. nov., sp. nov., isolated from solar saltern sediment.

A novel non-pigmented, Gram-stain-negative, motile by means of a polar flagellum, aerobic and rod-shaped bacterium, designated HMF8227T, was isolated from solar saltern sediment sampled at Shinan, Republic of Korea. The isolate was able to grow at 15-42 °C (optimum, 37 °C), at pH 6-8 (pH 7) and with 0.5-12 % NaCl (2-5 %). Strain HMF8227T was positive for hydrolysis of starch and dextrin. 16S rRNA gene sequence analysis revealed that strain HMF8227T was affiliated with the family Alteromonadaceae, sharing the highest sequence similarities to the genera Salinimonas (93.0-94.4 %), Aestuariibacter (92.0-94.2 %), Alteromonas (92.0-93.6 %) and Lacimicrobium (93.6 %). In the phylogenetic trees, strain HMF8227T formed an independent clade with Lacimicrobium alkaliphilum X13M-12T. The major fatty acids were C16 : 0, summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c) and summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c). The major respiratory quinone was ubiquinone-8 (Q-8). The major polar lipids are phosphatidylglycerol, phosphatidylethanolamine, one unidentified aminolipid and two unidentified glycolipids. The DNA G+C content of the genomic DNA was 52.1 mol%. On the basis of the polyphasic characterizations, strain HMF8227T represents a novel species and genus within the family Alteromonadaceae, for which the name Saliniradius amylolyticus gen. nov., sp. nov. is proposed, with the type strain being HMF8227T (=KCTC 62462T =NBRC 113230T).

Pseudidiomarina maritima Wu et al. 2009 is a later heterotypic synonym of Pseudidiomarina tainanensis Jean et al. 2009 and emended description of the species.

A comparative analysis of the two type strains of Pseudidiomarina maritima 908087T and Pseudidiomarina tainanensis PIN1T was performed to examine their taxonomic relationship. The 16S rRNA gene sequence of P. maritima 908087T shared a high similarity (99.8 %) with that of P. tainanensis PIN1T. The phylogenetic trees based on 16S rRNA gene sequences indicated that the two strains formed a tight cluster within the genus Pseudidiomarina. Whole genomic comparison between the two strains revealed a digital DNA-DNA hybridization estimate of 75.8 % and an average nucleotide identity value of 97.3 %, strongly indicating that they represented a single species. In addition, the strains did not display any striking differences in their metabolic, physiological or chemotaxonomic features. Therefore, we propose that Pseudidiomarina maritima is a later heterotypic synonym of Pseudidiomarina tainanensis.

Colwellia ponticola sp. nov., isolated from seawater.

A Gram-stain-negative, aerobic, motile and rod-shaped bacterial strain, designated OISW-25T, was isolated from seawater in Republic of Korea. Strain OISW-25T grew optimally at 25 °C and in the presence of 2.0 % (w/v) NaCl. The phylogenetic trees based on 16S rRNA gene sequences showed that strain OISW-25T fell within the clade comprising the type strains of Colwellia species. Strain OISW-25T exhibited 16S rRNA gene sequence similarity values of 97.5, 97.2 and 97.1 % to the type strains of C. piezophila, C. maris and C. psychrerythraea, respectively, and of 93.6-96.6 % to the type strains of the other Colwellia species. The average nucleotide identity values between strain OISW-25T and C. piezophila ATCC BAA-637T and two non-type strains of C. psychrerythraea were 78.16-79.35 % and DNA-DNA relatedness value of strain OISW-25T with the type strain of C. maris was 17 %. The DNA G+C content of strain OISW-25T was 39.2 mol% (HPLC) or 38.7 mol% (genome data). Strain OISW-25T contained Q-8 as the predominant ubiquinone and summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c) and C16 : 0 as the major fatty acids. The major polar lipids of strain OISW-25T were phosphatidylethanolamine and phosphatidylglycerol. Distinguished phenotypic properties, along with the phylogenetic and genetic distinctiveness, revealed that strain OISW-25T is distinct from Colwellia species. On the basis of the data presented, strain OISW-25T is considered to represent a novel species of the genus Colwellia, for which the name Colwellia ponticola sp. nov. is proposed. The type strain is OISW-25T (=KCTC 62426T=NBRC 113187T).