Pleionea litopenaei sp. nov., isolated from the gastric tract of juvenile Pacific white shrimp Litopenaeus vannamei.

A Gram-stain-negative, aerobic, rod-shaped and motile strain HL-JVS1T, was isolated from the gastric tract of a juvenile Pacific white shrimp. Molecular phylogenetic analysis based on 16S rRNA gene sequences of strain HL-JVS1T revealed its affiliation with the genus Pleionea, with close relatives including Pleionea mediterranea MOLA115T (97.5%) and Pleionea sediminis S1-5-21T (96.2%). The complete genome of strain HL-JVS1T consisted of a circular 4.4 Mb chromosome and two circular plasmids (6.6 and 35.0 kb) with a G + C content of 43.1%. The average nucleotide identity and digital DNA-DNA hybridization values between strain HL-JVS1T and the type strains of described Pleionea species were 69.7-70.4% and 18.3-18.6%, respectively. Strain HL-JVS1T grew at 10-40 °C (optimum, 30 °C) in the presence of 0.5 - 9.0% (w/v) sea salts (optimum, 2.0 - 2.5%), and at pH range of 5.5 - 10.0 (optimum, pH 6.5). The major fatty acids (> 10%) were summed feature 9 (iso-C17:1 ω9c and/or C16:0 10-methyl) (23.3%), iso-C16:0 (14.5%), iso-C11:0 3-OH (13.8%) and iso-C15:0 (11.0%). The polar lipids were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, an unidentified aminophospholipid, two unidentified aminolipids, and two unidentified lipids. The respiratory quinone was ubiquinone-8. The comprehensive phylogenetic, phylogenomic, phenotypic and chemotaxonomic results showed that strain HL-JVS1T is distinct from other Pleionea species. Hence, we propose strain HL-JVS1T as a novel species belonging to the genus Pleionea, for which the name Pleionea litopenaei sp. nov. is proposed with HL-JVS1T (= KCCM 90514T = JCM 36490T) as the type strain.

Jiella pelagia sp. nov., isolated from the phosphonate-amended seawater of the northwestern Pacific Ocean.

A novel Gram-stain-negative, aerobic, rod-shaped bacterium, designated as HL-NP1T, was isolated from the surface water of the northwestern Pacific Ocean after enrichment cultivation using the organic phosphorous compound of 2-aminoethylphosphonate. Phylogenetic analysis based on 16S rRNA gene sequences showed that the strain belonged to the genus Jiella, with the highest similarity to Jiella pacifica 40Bstr34T (98.7 %). The complete genome sequence of strain HL-NP1T comprised a circular chromosome of 5.58 Mbp and two circular plasmids of 0.15 and 0.22 Mbp. Comparison of the genome sequences between strains HL-NP1T and J. pacifica 40Bstr34T revealed that average nucleotide identity, average amino acid identity and digital DNA-DNA hybridization values (88.0, 86.4 and 33.9 %, respectively) were below the recommended cut-off levels for delineating bacterial species. Strain HL-NP1T showed optimal growth at 30 °C, pH 6.5-7.0, with 2.0-2.5 % (w/v) NaCl. The sole respiratory quinone was ubiquinone-10. The predominant fatty acid was summed feature 8 (C18 : 1 ω6c and/or C18 : 1 ω7c). The polar lipids comprised diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylmonomethylethanolamine, an unidentified aminolipid and four unidentified lipids. The G+C content of the genomic DNA was 65.1 %. Based on phylogenetic, genotypic, phenotypic and chemotaxonomic data, strain HL-NP1T is proposed to represent a novel species of the genus Jiella, for which the name Jiella pelagia sp. nov. is proposed. The type strain is HL-NP1T (= KCCM 90499T = JCM 35838T).

Maribacter litopenaei sp. nov., isolated from the intestinal tract of the Pacific white shrimp Litopenaeus vannamei.

A Gram-stain-negative, aerobic, rod-shaped bacterial strain, designated HL-LV01T, was isolated from the intestinal tract content of the Pacific white shrimp Litopenaeus vannamei. The 16S rRNA gene sequence of strain HL-LV01T showed that the strain was clearly a member of the genus Maribacter. According to the phylogenetic analyses, strain HL-LV01T was most closely related to the species Maribacter flavus KCTC 42508T with 98.2 % sequence similarity. The average nucleotide identity and digital DNA-DNA hybridization values between strain HL-LV01T and M. flavus KCTC 42508T were 80.6 % and 23.0 %, respectively, indicating different genomic species in the genus Maribacter. Strain HL-LV01T showed optimal growth at 35 °C, pH 7.0, and 2.5 % (w/v) sea salts. The major cellular fatty acids were iso-C15 : 0 (32.5 %), iso-C17 : 0 3-OH (22.3 %), and iso-C15 : 1 G (15.5 %). The major respiratory quinone was menaquinone-6. The polar lipids consisted of phosphatidylethanolamine, three unidentified aminolipids, and seven unidentified lipids. The genomic DNA G+C content of the strain was 39.8 mol%. The comprehensive phylogenetic, genomic, phenotypic, and chemotaxonomic results indicate that strain HL-LV01T is distinct from validly published species of the genus Maribacter. Hence, we propose strain HL-LV01T as a novel species belonging to the genus Maribacter, for which the name Maribacter litopenaei sp. nov. is proposed. The type strain is HL-LV01T (= KCCM 90498T = JCM 35709T).

Roseovarius pelagicus sp. nov., a facultatively anaerobic bacterium with potential for degrading polypropylene, isolated from Arctic seawater.

A Gram-stain-negative, facultatively anaerobic, non-motile, rod-shaped bacterial strain, designated HL-MP18T, was isolated from Arctic seawater after a prolonged incubation employing polypropylene as the sole carbon source. Phylogenetic analyses of the 16S rRNA gene sequence revealed that strain HL-MP18T was affiliated to the genus Roseovarius with close relatives Roseovarius carneus LXJ103T (96.8 %) and Roseovarius litorisediminis KCTC 32327T (96.5 %). The complete genome sequence of strain HL-MP18T comprised a circular chromosome of 3.86 Mbp and two circular plasmids of 0.17 and 0.24 Mbp. Genomic comparisons based on average nucleotide identity and digital DNA-DNA hybridization showed that strain HL-MP18T was consistently discriminated from its closely related taxa in the genus Roseovarius. Strain HL-MP18T showed optimal growth at 25 °C, pH 7.0 and 2.5 % (w/v) sea salts. The major cellular fatty acids were C18 : 1 ω6c and/or C18 : 1 ω7c (49.6 %), C19 : 0 cyclo ω8c (13.5 %), and C16 : 0 (12.8 %). The major respiratory quinone was ubiquinone-10. The polar lipids consisted of phosphatidylcholine, phosphatidylglycerol, an unidentified aminolipid and three unidentified lipids. The genomic DNA G+C content of the strain was 59.2 mol%. The phylogenetic, genomic, phenotypic and chemotaxonomic results indicate that strain HL-MP18T is distinguishable from the recognized species of the genus Roseovarius. Therefore, we propose that strain HL-MP18T represents a novel species belonging to the genus Roseovarius, for which the name Roseovarius pelagicus sp. nov. is proposed. The type strain is HL-MP18T (=KCCM 90405T=JCM 35639T).

Hymenobacter siberiensis sp. nov., isolated from a marine sediment of the East Siberian Sea and Hymenobacter psoromatis sp. nov., isolated from an Antarctic lichen.

Gram-stain-negative, strictly aerobic, red-pink-coloured, rod-shaped and non-motile bacterial strains PAMC 29290, PAMC 29294T and PAMC 29296 were isolated from marine surface sediment sampled in the East Siberian Sea and strains PAMC 26553 and PAMC 26554T were obtained from an Antarctic lichen. Strains PAMC 29290, PAMC 29294T and PAMC 29296 were closely related to Hymenobacter artigasi (98.8 % 16S rRNA gene similarity), Hymenobacter antarcticus (97.3 %) and Hymenobacter glaciei (96.9 %), and PAMC 26553 and PAMC 26554T showed high similarity to Hymenobacter ginsengisoli (97.0 %), Hymenobacter rivuli (96.1 %) and Hymenobacter setariae (95.9 %). Genomic relatedness analyses showed that strains PAMC 29290, PAMC 29294T and PAMC 29296 could be distinguished from H. artigasi by average nucleotide identity (ANI; 93.1-93.2 %) and digital DNA-DNA hybridization (dDDH; 50.3-51.0 %) values. Strains PAMC 26553 and PAMC 26554T could be clearly distinguished from H. ginsengisoli with ANI values <79.8 % and dDDH values <23.3 %. The major fatty acids of strains PAMC 29290, PAMC 29294T and PAMC 29296 were C15 : 0 iso (21.0-26.0 %), summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c; 17.4-18.2 %), C15 : 0 anteiso (12.7-19.1 %) and summed feature 4 (C17 : 1 iso I and/or anteiso B; 8.6-16.1 %) and those of strains PAMC 26553 and PAMC 26554T were summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c; 20.7-22.2 %), C15 : 0 anteiso (17.5-19.7 %) and summed feature 4 (C17 : 1 iso I and/or anteiso B; 15.5-18.1 %). The major respiratory quinone was MK-7. The genomic DNA G+C contents were 60.6-60.8 mol%. The polar lipids of PAMC 29294T were found to consist of phosphatidylethanolamine, four unidentified aminolipids, an unidentified aminophospholipid and five unidentified lipids; those of PAMC 26554T were phosphatidylethanolamine, three unidentified aminolipids, four unidentified aminophospholipid and two unidentified lipids. The distinct phylogenetic position and some physiological characteristics distinguished the novel strains from closely related type strains in the genus Hymenobacter. Thus, two novel species are proposed, with the names Hymenobacter siberiensis sp. nov. (type strain, PAMC 29294T=KCTC 82466T=JCM 34574T) and Hymenobacter psoromatis sp. nov. (type strain, PAMC 26554T=KCTC 82464T=JCM 34572T), respectively.

Pseudomonas neustonica sp. nov., isolated from the sea surface microlayer of the Ross Sea (Antarctica).

Gram-stain-negative, aerobic and rod-shaped bacterial strains, designated SSM26T and SSM44, were isolated from a sea surface microlayer sample from the Ross Sea, Antarctica. Analysis of the 16S rRNA gene sequences of strains SSM26T and SSM44 revealed a clear affiliation with the genus Pseudomonas. Based on the results of phylogenetic analysis, strains SSM26T and SSM44 showed the closest phylogenetic relationship with the species Pseudomonas sabulinigri KCTC 22137T with the 16S rRNA gene sequence similarity level of 98.5 %. Strains SSM26T and SSM44 grew optimally at 30 °C, pH 7.0-7.5 and 0.5-10.0 % NaCl (w/v). The major cellular fatty acids were C18 : 1 ω7c (31.3-34.9 %), C16 : 0 (15.5-20.2 %), summed feature 3 (C16 : 1 ω7c/C16 : 1 ω6c; 19.5-25.4 %) and C12 : 0 (6.0-9.3 %). The genomic DNA G+C content of each strain was 56.2 mol%. Genomic relatedness analyses based on the average nucleotide identity and the genome-to-genome distance showed that strains SSM26T and SSM44 constituted a single species that was clearly distinguishable from its phylogenetically close relatives. The combined phenotypic, chemotaxonomic, genomic and phylogenetic data also showed that strains SSM26T and SSM44 could be distinguished from validly published members of the genus Pseudomonas. Thus, these strains should be classified as representing a novel species in the genus Pseudomonas, for which the name Pseudomonas neustonica sp. nov. is proposed with the type strain SSM26T (=KCCM 43193T=JCM 31284T=PAMC 28426T) and a sister strain SSM44 (=KCCM 43194=JCM 31285=PAMC 28427).

Sandaracinobacter neustonicus sp. nov., isolated from the sea surface microlayer in the Southwestern Pacific Ocean, and emended description of the genus Sandaracinobacter.

A Gram-stain-negative, non-motile, facultatively anaerobic and rod-shaped bacterial strain, designated PAMC 28131T, was isolated from a sea surface microlayer sample in the open water of the Pacific Ocean. Phylogenetic analysis of the 16S rRNA gene sequence of strain PAMC 28131T revealed an affiliation to the genus Sandaracinobacter with the closest species Sandaracinobacter sibiricus RB16-17T (sequence similarity of 98.2 %). Strain PAMC 28131T was able to grow optimally with 0.5-1.0 % NaCl and at pH 6.5-7.0 and 30 °C. The polar lipids were phosphatidylglycerol, phosphatidylethanolamine, two unidentified phospholipids, an unidentified aminolipid, an unidentified glycolipid and an unidentified lipid. The major cellular fatty acids (>10 %) were C18 : 1 ω6c and/or C18 : 1 ω7c, (42.6 %), C17 : 1 ω6c (19.3 %) and C16 : 1 ω6c and/or C16 : 1 ω7c (15.8 %), and the respiratory quinone was Q-10. The genomic DNA G+C content was 65.3 mol%. The phylogenetic, phenotypic and chemotaxonomic data showed that strain PAMC 28131T could be clearly distinguished from S. sibiricus RB16-17T. Thus, strain PAMC 28131T should be classified as representing a novel species in the genus Sandaracinobacter, for which the name Sandaracinobacter neustonicus sp. nov. is proposed. The type strain is PAMC 28131T (=KCCM 43127T=JCM 30734T).

Shewanella psychromarinicola sp. nov., a psychrophilic bacterium isolated from pelagic sediment of the Ross Sea (Antarctica), and reclassification of Shewanella arctica Kim et al. 2012 as a later heterotypic synonym of Shewanella frigidimarina Bowman et al. 1997.

Two Gram-stain-negative, rod-shaped, facultatively anaerobic, iron-reducing bacterial strains, designated M2T and R106, were isolated from pelagic surface-sediment of the Ross Sea, Antarctica. The 16S rRNA gene sequence analysis revealed that strains M2T and R106 were affiliated to the genus Shewanellaand formed a distinct subline in a robust clade encompassing Shewanella vesiculosa, Shewanella livingstonensis, Shewanella arcticaand Shewanella frigidimarinawith a range of sequence similarities of 98.1-98.9 %. Overall genome relatedness indices indicated that M2T and R106 represented a single genomic species, which was clearly distinguishable from the phylogenetically close relatives with lower values of species delineation thresholds. Cells of M2T grew optimally at 10-15 °C and pH 6.5 in the presence of 3.0-4.0 % (w/v) sea salts. The polar lipids of M2T comprised phosphatidylglycerol, phosphatidylethanolamine, two unidentified aminophospholipids, an unidentified aminolipid and an unidentified phospholipid. Quinones were Q-7, Q-8, MK-7 and MMK-7. The major cellular fatty acids (>10 %) were C16 : 1ω7c and/or C16 : 1ω6c, C16 : 0 and C17 : 1ω8c. The DNA G+C content was 42.2 mol%. On the basis of the phenotypic, phylogenetic, genomic and chemotaxonomic features, we propose the name Shewanellapsychromarinicola sp. nov. with the type strain M2T (=KCCM 43257T =JCM 32090T) and the reclassification of S. arcticaas a later heterotypic synonym of S. frigidimarina.

Lichenihabitans psoromatis gen. nov., sp. nov., a member of a novel lineage (Lichenihabitantaceae fam. nov.) within the order of Rhizobiales isolated from Antarctic lichen.

Two Gram-stain-negative, facultative anaerobic chemoheterotrophic, pink-coloured, rod-shaped and non-motile bacterial strains, PAMC 29128 and PAMC 29148T, were isolated from lichen. Phylogenetic analysis based on the 16S rRNA gene sequences revealed that strains PAMC 29128 and PAMC 29148T belong to lichen-associated Rhizobiales-1 (LAR1), an uncultured phylogenetic lineage of the order Rhizobiales and the most closely related genera were Methylocapsa (<93.9 %) and Methylosinus (<93.8 %). The results of phylogenomic and genomic relatedness analyses also showed that strains PAMC 29128 and PAMC 29148T were clearly distinguished from other species in the order Rhizobiales with average nucleotide identity values of <71.4 % and genome-to-genome distance values of <22.7 %. Genomic analysis revealed that strains PAMC 29128 and PAMC 29148T did not contain genes involved in atmospheric nitrogen fixation or utilization of carbon compounds such as methane and methanol. Strains PAMC 29128 and PAMC 29148T were able to utilize certain monosaccharides, disaccharides, sugar alcohols and other organic compounds as a sole carbon source. The major fatty acids (>10 %) were summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c; 33.7-39.7 %), summed feature 3 (C16 : 1 ω7c and/or C 16:1 ω6c; 25.2-25.4 %) and C19 :0 cyclo ω8c (11.9-15.4 %). The major respiratory quinone was Q-10. The genomic DNA G+C contents of PAMC 29128 and PAMC 29148T were 63.0 and 63.1 mol%, respectively. Their distinct phylogenetic position and some physiological characteristics support the proposal of Lichenihabitans gen. nov., with the type species Lichenihabitans psoromatis sp. nov. (type strain, PAMC 29148T=KCCM 43293T=JCM 33311T). Lichenihabitantaceae fam. nov. is also proposed.

Arctic Primary Aerosol Production Strongly Influenced by Riverine Organic Matter.

The sources of primary and secondary aerosols in the Arctic are still poorly known. A number of surface seawater samples-with varying degrees of Arctic riverine and sea ice influences-were used in a sea spray generation chamber to test them for their potential to produce sea spray aerosols (SSA) and cloud condensation nuclei (CCN). Our interdisciplinary data showed that both sea salt and organic matter (OM) significantly influenced the SSA production. The number concentration of SSA in the coastal samples was negatively correlated with salinity and positively correlated with a number of OM tracers, including dissolved and chromophoric organic carbon (DOC, CDOM), marine microgels and chlorophyll a (Chl-a) but not for viral and bacterial abundances; indicating that OM of riverine origin enhances primary aerosol production. When all samples were considered, transparent exopolymer particles (TEP) were found to be the best indicator correlating positively with the ratio number concentration of SSA/salinity. CCN efficiency was not observed to differ between the SSA from the various samples, despite differences in organic characteristics. It is suggested that the large amount of freshwater from river runoff have a substantial impact on primary aerosols production mechanisms, possibly affecting the cloud radiative forcing.

Sea spray aerosol as a unique source of ice nucleating particles.

Ice nucleating particles (INPs) are vital for ice initiation in, and precipitation from, mixed-phase clouds. A source of INPs from oceans within sea spray aerosol (SSA) emissions has been suggested in previous studies but remained unconfirmed. Here, we show that INPs are emitted using real wave breaking in a laboratory flume to produce SSA. The number concentrations of INPs from laboratory-generated SSA, when normalized to typical total aerosol number concentrations in the marine boundary layer, agree well with measurements from diverse regions over the oceans. Data in the present study are also in accord with previously published INP measurements made over remote ocean regions. INP number concentrations active within liquid water droplets increase exponentially in number with a decrease in temperature below 0 °C, averaging an order of magnitude increase per 5 °C interval. The plausibility of a strong increase in SSA INP emissions in association with phytoplankton blooms is also shown in laboratory simulations. Nevertheless, INP number concentrations, or active site densities approximated using "dry" geometric SSA surface areas, are a few orders of magnitude lower than corresponding concentrations or site densities in the surface boundary layer over continental regions. These findings have important implications for cloud radiative forcing and precipitation within low-level and midlevel marine clouds unaffected by continental INP sources, such as may occur over the Southern Ocean.

Complete genome of streamlined marine actinobacterium Pontimonas salivibrio strain CL-TW6T adapted to coastal planktonic lifestyle.

BACKGROUND: Pontimonas salivibrio strain CL-TW6T (=KCCM 90105 = JCM18206) was characterized as the type strain of a new genus within the Actinobacterial family Microbacteriaceae. It was isolated from a coastal marine environment in which members of Microbactericeae have not been previously characterized. RESULTS: The genome of P. salivibrio CL-TW6T was a single chromosome of 1,760,810 bp. Genomes of this small size are typically found in bacteria growing slowly in oligotrophic zones and said to be streamlined. Phylogenetic analysis showed it to represent a lineage originating in the Microbacteriaceae radiation occurring before the snowball Earth glaciations, and to have a closer relationship with some streamlined bacteria known through metagenomic data. Several genomic characteristics typical of streamlined bacteria are found: %G + C is lower than non-streamlined members of the phylum; there are a minimal number of rRNA and tRNA genes, fewer paralogs in most gene families, and only two sigma factors; there is a noticeable absence of some nonessential metabolic pathways, including polyketide synthesis and catabolism of some amino acids. There was no indication of any phage genes or plasmids, however, a system of active insertion elements was present. P. salivibrio appears to be unusual in having polyrhamnose-based cell wall oligosaccharides instead of mycolic acid or teichoic acid-based oligosaccharides. Oddly, it conducts sulfate assimilation apparently for sulfating cell wall components, but not for synthesizing amino acids. One gene family it has more of, rather than fewer of, are toxin/antitoxin systems, which are thought to down-regulate growth during nutrient deprivation or other stressful conditions. CONCLUSIONS: Because of the relatively small number of paralogs and its relationship to the heavily characterized Mycobacterium tuberculosis, we were able to heavily annotate the genome of P. salivibrio CL-TW6T. Its streamlined status and relationship to streamlined metagenomic constructs makes it an important reference genome for study of the streamlining concept. The final evolutionary trajectory of CL-TW6 T was to adapt to growth in a non-oligotrophic coastal zone. To understand that adaptive process, we give a thorough accounting of gene content, contrasting with both oligotrophic streamlined bacteria and large genome bacteria, and distinguishing between genes derived by vertical and horizontal descent.

Kiloniella antarctica sp. nov., isolated from a polynya of Amundsen Sea in Western Antarctic Sea.

A taxonomic study was conducted on strain soj2014T, which was isolated from the surface water of a polynya in the Antarctic Sea. Comparative 16S rRNA gene sequence analysis showed that strain soj2014T belongs to the family Kiloniellaceae and is closely related to Kiloniella spongiae MEBiC09566T, 'Kiloniella litopenaei' P1-1T and Kiloniella laminariae LD81T (98.0 %, 97.8 % and 96.2 % 16S rRNA gene sequence similarity, respectively). The DNA-DNA hybridization values between strain soj2014T and closely related strains were below 28.6 %. The G+C content of the genomic DNA of strain soj2014T was 45.5 mol%. The predominant cellular fatty acids were summed feature 8 (composed of C18 : 1ω6c/C18 : 1ω7c, 57.0 %) and summed feature 3 (composed of C16 : 1ω6c/C16 : 1ω7c, 23.5 %). Strain soj2014T was Gram-stain-negative, slightly curved, spiral-shaped, and motile with a single polar flagellum. The strain grew at 0-30 °C (optimum, 25 °C), in 1.5-5.1 % (w/v) NaCl (optimum, 2.1-2.4 %) and at pH 5.5-9.5 (optimum, 7.5-8.0). It also had differential carbohydrate utilization traits and enzyme activities compared with closely related strains. Based on these phylogenetic, phenotypic and chemotaxonomic analyses, strain soj2014T represents a distinct species, separable from the reference strains, and is, therefore, proposed as a novel species, Kiloniella antarctica sp. nov. The type strain is soj2014T (=KCTC 42186T=JCM 30386T).

Prokaryotic community composition in alkaline-fermented skate (Raja pulchra).

Prokaryotes were extracted from skates and fermented skates purchased from fish markets and a local manufacturer in South Korea. The prokaryotic community composition of skates and fermented skates was investigated using 16S rRNA pyrosequencing. The ranges for pH and salinity of the grinded tissue extract from fermented skates were 8.4-8.9 and 1.6-6.6%, respectively. Urea and ammonia concentrations were markedly low and high, respectively, in fermented skates compared to skates. Species richness was increased in fermented skates compared to skates. Dominant and predominant bacterial groups present in the fermented skates belonged to the phylum Firmicutes, whereas those in skates belonged to Gammaproteobacteria. The major taxa found in Firmicutes were Atopostipes (Carnobacteriaceae, Lactobacillales) and/or Tissierella (Tissierellaceae, Tissierellales). A combination of RT-PCR and pyrosequencing for active bacterial composition showed that the dominant taxa i.e., Atopostipes and Tissierella, were active in fermented skate. Those dominant taxa are possibly marine lactic acid bacteria. Marine bacteria of the taxa Lactobacillales and/or Clostridia seem to be important in alkaline fermentation of skates.

Pseudoalteromonas neustonica sp. nov., isolated from the sea surface microlayer of the Ross Sea (Antarctica), and emended description of the genus Pseudoalteromonas.

A Gram-stain-negative, facultatively anaerobic, rod-shaped and motile strain, designated PAMC 28425T, was isolated from a sea surface microlayer sample from the Ross Sea, Antarctica. Analysis of the 16S rRNA gene sequence of strain PAMC 28425T showed an affiliation with the genus Pseudoalteromonas. Phylogenetic analyses revealed that strain PAMC 28425T formed a clade with Pseudoalteromonas prydzensis MB8-11T and Pseudoalteromonas mariniglutinosaKMM 3635T with 16S rRNA gene sequence similarities of 98.3-98.6 %. Genomic relatedness analyses based on the average nucleotide identity and the genome-to-genome distance showed that strain PAMC 28425T is clearly distinguished from the phylogenetically close relatives. Cells of strain PAMC 28425T grew optimally at 25 °C and pH 7.5-8.5 in the presence of 1.0-3.0 % (w/v) sea salts. The major cellular fatty acids (>10 %) were C16 : 1ω6c and/or C16 : 1ω7c, C16 : 0, and C18 : 1ω6c and/or C18 : 1ω7c. The genomic DNA G+C content was 39.7 mol%. On the basis of the phylogenetic, genomic, chemotaxonomic and phenotypic data presented, we propose the name Pseudoalteromonas neustonica sp. nov. with the type strain PAMC 28425T (=KCCM 43187T=JCM 31286T).

Reclassification of Halomonas caseinilytica Wu et al. 2008 as a later synonym of Halomonas sinaiensis Romano et al. 2007, and emendation of the species description.

The taxonomic relationship between Halomonas sinaiensis DSM 18067(T) and Halomonas caseinilytica JCM 14802(T) has not been established, despite the high similarity (99.6 %) of their 16S rRNA gene sequences. To clarify their taxonomic positions, a polyphasic approach was applied to both type strains. Genomic relatedness analyses between H. sinaiensis DSM 18067(T) and H. caseinilytica JCM 14802(T) resulted in an average nucleotide identity of 99.5 % and an estimated DNA-DNA hybridization of 96.1 % by the genome-to-genome distance calculator, indicating that they belong to a single species. Phenotypic and chemotaxonomic characteristics showed no pronounced differences between the two type strains. Based on the results of this polyphasic study, it is proposed that H. caseinilytica JCM 14802(T) is a later heterotypic synonym of H. sinaiensis DSM 18067(T). An emended description for the species H. sinaiensis is given.

Algibacter psychrophilus sp. nov., a psychrophilic bacterium isolated from marine sediment.

A Gram-stain-negative, aerobic, yellow-pigmented, flexirubin-negative, rod-shaped, non-motile and psychrophilic bacterial strain, PAMC 27237T, was isolated from marine sediment of the Ross Sea, Antarctica. Strain PAMC 27237T grew at 0-20 °C (optimally at 17 °C), at pH 5.0-9.5 (optimally at pH 7.0) and in the presence of 0-3.5 % (w/v) NaCl (optimally at 1.5-2.5 %). The major fatty acids (≥5 %) were iso-C17 : 0 3-OH, C17 : 0 2-OH, anteiso-C15 : 0, summed feature 3 (C16 : 1ω6c/C16 : 1ω7c), iso-C15 : 0 3-OH, anteiso-C17 : 1ω9c, anteiso-C15 : 1 A, iso-C16 : 0 3-OH and iso-C15 : 1 G. The major polar lipids were phosphatidylethanolamine, two unidentified aminolipids, four unidentified lipids and a glycolipid. The major respiratory quinone was MK-6. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that strain PAMC 27237T belongs to the genus Algibacter, showing high similarities with the type strains of Algibacter agarivorans (97.2 %), Algibacter agarilyticus (97.0 %) and Algibacter mikhailovii (96.4 %). Average nucleotide identity values between strain PAMC 27237T and the type strains of A. agarivorans and A. agarilyticuswere 83.1 and 84.2 %, respectively, and mean genome-to-genome distances were 22.4-24.2 %, indicating that strain PAMC 27237T is clearly distinguished from the most closely related species of the genus Algibacter. The genomic DNA G+C content calculated from genome sequences was 33.5 mol%. Based on the phenotypic, chemotaxonomic and phylogenetic data presented, strain PAMC 27237T is considered to represent a novel species of the genus Algibacter, for which the name Algibacter psychrophilus sp. nov. is proposed. The type strain is PAMC 27237T ( = KCTC 42130T = JCM 30370T).

Sediminicola arcticus sp. nov., a psychrophilic bacterium isolated from deep-sea sediment, and emended description of the genus Sediminicola.

A Gram-stain-negative, rod-shaped and non-motile strain, designated PAMC 27266(T), was isolated from deep-sea sediment of the Arctic Ocean. Analysis of the 16S rRNA gene sequence of strain PAMC 27266(T) showed closest affiliation with the genus Sediminicola . Phylogenetic analyses revealed that strain PAMC 27266(T) formed a robust clade with Sediminicola luteus CNI-3(T), with which it shared 98.9% 16S rRNA gene sequence similarity. Genomic relatedness analyses based on the average nucleotide identity and genome-to-genome distance showed that strain PAMC 27266(T) is clearly distinguished from S. luteus . Cells of strain PAMC 27266(T) grew optimally at 15 °C and pH 6.5-7.5 in the presence of 3.5% (w/v) sea salts. The major polar lipids were phosphatidylethanolamine, two unidentified aminophospholipids and two unidentified lipids. The only respiratory quinone was menaquinone-6. The major cellular fatty acids (>10%) were C16 : 1ω6c and/or C16 : 1ω7c and C15 : 0. The genomic DNA G+C content was 37.9 mol%. Based on the phylogenetic, genomic, chemotaxonomic and phenotypic data presented, we propose strain PAMC 27266(T) ( =KCCM 43038(T) =JCM 19894(T)) as the type strain of a novel species, with the name Sediminicola arcticus sp. nov.

Domibacillus tundrae sp. nov., isolated from active layer soil of tussock tundra in Alaska, and emended description of the genus Domibacillus.

A novel Gram-stain-positive, spore-forming, aerobic, motile and rod-shaped bacterium designated strain PAMC 80007T was isolated from an active layer soil sample of Council, Alaska. Optimal growth of strain PAMC 80007T was observed at 30 °C, pH 7.0 and in the presence of 2 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequence indicated that strain PAMC 80007T belonged to the genus Domibacillus. This strain was closely related to Domibacillus enclensis (98.3 %), Domibacillus robiginosus (98.3 %) and Domibacillus indicus (97.2 %). Genomic DNA G+C content was 43.5 mol% and genomic relatedness analyses based on the average nucleotide identity and the genome-to-genome distance showed that strain PAMC 80007T is clearly distinguished from the closely related species of the genus Domibacillus. The major fatty acids (>5 %) were iso-C15 : 0 (24.7 %), C16 : 1ω11c (16.8 %), anteiso-C15 : 0 (16.5 %), C16 : 0 (15.6 %) and anteiso-C17 : 0 (8.7 %). The major respiratory isoprenoid quinones were menaquinone-6 (MK-6) and menaquinone-7 (MK-7), and the polar lipid profile contained diphosphatidylglycerol, phosphatidylglycerol, phosphoglycolipid, phospholipid and two unidentified lipids. meso-Diaminopimelic acid (type A1γ) was present in the cell-wall peptidoglycan, and the major whole-cell sugar was ribose with a minor quantity of glucose. Results from a polyphasic study suggested that strain PAMC 80007T represents a novel species of the genus Domibacillus for which the name Domibacillus tundrae sp. nov. is proposed. The type strain is PAMC 80007T ( = JCM 30371T = KCTC 33549T = DSM 29572T). An emended description of the genus Domibacillus is also provided.

Psychroserpens jangbogonensis sp. nov., a psychrophilic bacterium isolated from Antarctic marine sediment.

A Gram-staining-negative, yellow-pigmented, aerobic, rod-shaped and non-motile bacterium, PAMC 27130(T), was isolated from the marine sediment of the Ross Sea, Antarctica. The temperature, pH and NaCl tolerance ranges for growth were 4-20 °C, pH 6.0-9.0 and 0.5-5.0 % (w/v) NaCl, respectively. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain PAMC 27130(T) belonged to the genus Psychroserpens and was closely related to Psychroserpens mesophilus, Psychroserpens damuponensis and Psychroserpens burtonensis with 97.2, 94.7 and 94.2 % sequence similarities, respectively. Genomic relatedness analyses based on average nucleotide identity and genome-to-genome distance showed that strain PAMC 27130(T) could be clearly distinguished from other species of the genus Psychroserpens . The genomic DNA G+C content was 32.7 mol%. The major fatty acids (>10 %) were C20 : 4ω6c (13.2 %), iso-C15 : 0 (12.3 %), iso-C15 : 1 G (11.7 %) and iso-C15 : 0 3-OH (10.0 %). The major respiratory isoprenoid quinone was menaquinone-6 (MK-6) and the polar lipids were phosphatidylethanolamine, two unidentified aminolipids, an unidentified phospholipid, an unidentified aminophospholipid and three unidentified lipids. On the basis of genotypic and phenotypic data collected in this study, it is proposed that strain PAMC 27130(T) represents a novel species of the genus Psychroserpens, for which the name Psychroserpens jangbogonensis sp. nov. is proposed. The type strain is PAMC 27130(T) ( = KCTC 42128(T) = JCM 30228(T)).