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A Gram-stain-negative and facultative aerobic bacterium, strain 16-MA T , was isolated from seawater of Yellow Sea in South Korea. Cells were catalase- and oxidase-positive and non-motile rods. Growth occurred at 4-37 °C (optimum, 30 °C) and pH 6.0-11.0 (optimum, 8.0), and in the presence of 0-7.0% NaCl (optimum, 3 %). Strain 16-MA T contained ubiquinone-8 as the sole isoprenoid quinone, C 16 : 0 and summed feature three as the major fatty acids (>10 %), and phosphatidylglycerol, phosphatidylethanolamine, an unidentified phospholipid, an unidentified aminophospholipid, and an unidentified polar lipid as the major polar lipids. The genome size and DNA G+C content of strain 16-MA T were 3.69 Mb and 46.0 mol%, respectively. Strain 16-MA T was most closely related to Alishewanella alkalitolerans LNK-7.1 T with a 97.9 % 16S rRNA gene sequence similarity. A phylogenomic tree based on whole genome sequences showed that strain 16-MA T formed a phylogenetic lineage within the genus Alishewanella . Based on the phenotypic, chemotaxonomic, and molecular analyses, strain 16-MA T represents a novel species of the genus Alishewanella , for which the name Alishewanella maricola is proposed. The type strain is 16-MA T (=KACC 22238 T =JCM 34596 T ).

A Gram-stain-negative, aerobic, yellow-pigmented, flexirubin-negative, rod-shaped and non-motile bacterial strain, PAMC 28998 T , was isolated from a surface sediment sample collected from the Canadian Beaufort Sea. Strain PAMC 28998 T grew at 4-37 °C (optimum, 25 °C), at pH 7.0-9.0 (optimum, pH 7.5) and in the presence of 1.0-10.0 % (w/v) NaCl. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that strain PAMC 28998 T belongs to the genus Antarcticibacterium showing the highest sequence similarity (96.8 %) with Antarcticibacterium flavum JB01H24 T . The average nucleotide identity and genome-to-genome distance values between PAMC 28998 T and the most closely related species ( A. flavum JB01H24 T ) were 74.1 and 18.5 %, respectively, indicating that strain PAMC 28998 T is clearly distinguished from A. flavum . The genomic DNA G+C content calculated from genome sequences was 39.8 %. The major fatty acids (>10 %) were iso-C 15 : 0 (19.5 %), anteiso-C 15 : 0 (18.0 %), iso-C 16 : 0 (11.6 %) and summed feature 3 (C 16:1 ω6 c and/or C 16:1 ω7 c ; 11.4 %). The major polar lipids were phosphatidylethanolamine, aminoglycolipid, two unidentified aminolipids, three unidentified phospholipids and four unidentified lipids. The major respiratory quinone was MK-6. Based on the phylogenetic, genomic and phenotypic data presented here, strain PAMC 28998 T is considered to represent a novel species of the genus Antarcticibacterium , for which the name Antarcticibacterium arcticum sp. nov. is proposed with the strain PAMC 28998 T (=KCCM 43316 T =JCM 33514 T ).

A Gram-stain-negative, non-motile, oxidase- and catalase-positive, rod-shaped bacterium was isolated from a coastal seawater sample from the Arctic Circle and designated strain IMCC9719 T . On the basis of 16S rRNA gene sequence analysis, it was shown that strain IMCC9719 T belonged to the genus Leucothrix and was closely related to the type strains of Leucothrix pacifica (97.6 % similarity) and Leucothrix mucor (95.1 %), while the strain shared <90.6 % sequence similarity with other bacterial species. The average nucleotide identity and genome-to-genome distance values between strain IMCC9719 T and L. pacifica JCM 18388 T were 71.7 and 16.9 %, respectively. The DNA G+C content of strain IMCC9719 T was 43.5 mol%. Optimum growth of strain IMCC9719 T was observed at 15 °C, at pH 7.5-8.5 and in the presence of 2.0-2.5 % (w/v) NaCl. The major fatty acids were summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), summed feature 8 (C18 : 1ω6c and/or C18 : 1ω7c) and C16 : 0. Cells of strain IMCC9719 T contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, an unidentified polar lipid, an unidentified aminophospholipid and two unidentified phospholipids. The major respiratory quinone was ubiquinone-8 (Q-8). Based on the taxonomic data collected in this study, strain IMCC9719 T represents a novel species of the genus Leucothrix, for which the name Leucothrix arctica sp. nov. is proposed. The type strain is IMCC9719 T (=KACC 18010 T =NBRC 110382 T ).

Strain Hb3 T was isolated from a tidal flat in Jeollabuk-do Gunsan, Republic of Korea. Cells were Gram-stain-negative, oxidase- and catalase-positive, rod-shaped and motile. The strain grew optimally at 25-35 °C, at pH 6.0-6.5 and with 3.0-10.0 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain Hb3 T belonged to the genus Halomonas. Strain Hb3 T was related most closely to Halomonas ventosae Al12 T (98.6 % 16S rRNA gene sequence similarity), Halomonas denitrificans M29 T (98.6 %) and Halomonas saccharevitans AJ275 T (98.4 %). Moreover, multilocus sequence analysis using the gyrB, rpoD and secA genes supported the phylogenetic position of strain Hb3 T . The genomic G+C content of strain Hb3 T was 67.9 mol%. DNA-DNA hybridization values for strain Hb3 T versus H. ventosae Al12 T , H. denitrificans M29 T and H. saccharevitans AJ275 T were 38.0, 54.5 and 47.4 %, respectively. The major quinone was ubiquinone Q-9 and the major fatty acids were C18 : 1ω7c, summed feature 3 (C16 : 1ω6c and/or C16 : 1ω7c), C16 : 0 and C19 : 0 cyclo ω8c. Diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, amino lipid, six unidentified phospholipids and an unidentified lipid comprised the polar lipid profile. On the basis of the data presented in this report, strain Hb3 T represents a novel species of the genus Halomonas. The name Halomonas aestuarii sp. nov. is proposed for this novel species. The type strain is Hb3 T (=KCTC 52253 T =JCM 31415 T ).

A Gram-staining-negative, non-motile, non-pigmented, rod-shaped bacterium was isolated from an Arctic coastal seawater sample and was designated strain IMCC9565T. Analysis of the 16S rRNA gene sequence of strain IMCC9565T revealed that the closest phylogenetic neighbours of the strain were members of the genus Planktotalea. Furthermore, the strain formed a robust clade with Planktotalea frisia SH6-1T, with which it shared 97.9 % 16S rRNA gene sequence similarity. Determination of genomic relatedness based on average nucleotide identity and genome-to-genome distance showed that strain IMCC9565T was distantly related to P. frisia, meaning the Arctic strain represents a novel species. Optimum growth of strain IMCC9565T was observed at 20 °C, pH 7.0 and in the presence of 2 % (w/v) NaCl. The major respiratory isoprenoid quinone was ubiquinone-10 (Q-10) and the major polar lipids consisted of phosphatidylglycerol, phosphatidylcholine, one unidentified aminolipid and two unidentified lipids. The principal fatty acids were C18 : 1ω7c and/or C18 : 1ω6c, C18 : 1ω7c 11-methyl and C16 : 0, and the DNA G+C content was 57.1 mol%. Based on these data, Planktotalea arctica sp. nov. is proposed to accommodate the bacterial isolate and the type strain is IMCC9565T (=KACC 18009T=NBRC 110393T).

Cryptophytes are ubiquitous and one of the major phototrophic components in marine plankton communities. They often cause red tides in the waters of many countries. Understanding the bloom dynamics of cryptophytes is, therefore, of great importance. A critical step in this understanding is unveiling their trophic modes. Prior to this study, several freshwater cryptophyte species and marine Cryptomonas sp. and Geminifera cryophila were revealed to be mixotrophic. The trophic mode of the common marine cryptophyte species, Teleaulax amphioxeia has not been investigated yet. Thus, to explore the mixotrophic ability of T. amphioxeia by assessing the types of prey species that this species is able to feed on, the protoplasms of T. amphioxeia cells were carefully examined under an epifluorescence microscope and a transmission electron microscope after adding each of the diverse prey species. Furthermore, T. amphioxeia ingestion rates heterotrophic bacteria and the cyanobacterium Synechococcus sp. were measured as a function of prey concentration. Moreover, the feeding of natural populations of cryptophytes on natural populations of heterotrophic bacteria was assessed in Masan Bay in April 2006. This study reported for the first time, to our knowledge, that T. amphioxeia is a mixotrophic species. Among the prey organisms offered, T. amphioxeia fed only on heterotrophic bacteria and Synechococcus sp. The ingestion rates of T. amphioxeia on heterotrophic bacteria or Synechococcus sp. rapidly increased with increasing prey concentrations up to 8.6×10 6 cells ml -1 , but slowly at higher prey concentrations. The maximum ingestion rates of T. amphioxeia on heterotrophic bacteria and Synechococcus sp. reached 0.7 and 0.3 cells predator -1  h -1 , respectively. During the field experiments, the ingestion rates and grazing coefficients of cryptophytes on natural populations of heterotrophic bacteria were 0.3-8.3 cells predator -1 h -1 and 0.012-0.033d -1 , respectively. Marine cryptophytes, including T. amphioxeia, are known to be favorite prey species for many mixotrophic and heterotrophic dinoflagellates and ciliates. Cryptophytes, therefore, likely play important roles in marine food webs and may exert a considerable potential grazing impact on the populations of marine bacteria., (Copyright © 2017 Elsevier B.V. All rights reserved.)

A Gram-staining-negative, moderately halophilic and strictly aerobic bacterium, designated strain KJ4T, was isolated from marine sediment at Gangjin in South Korea. Cells were catalase- and oxidase-positive long rods with gliding motility. Growth of strain KJ4T was observed at 4-37 °C (optimum, 15-25 °C), at pH 6.0-9.0 (optimum, pH 7.0-8.5) and in the presence of 1.0-7.0% (w/v) NaCl (optimum, 2.0-5.0%). Menaquinone 6 (MK-6) was the only isoprenoid quinone detected and iso-C15:0, iso-C17:0 3-OH, iso-C15:1 G and summed feature 3 (comprising C16:1ω7c and/or C16:1ω6c) were the major cellular fatty acids. The polar lipids of strain KJ4T consisted of phosphatidylethanolamine, an unidentified aminophospholipid and five unidentified lipids. The G+C content of the genomic DNA was 38.0 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain KJ4T formed a distinct phylogenetic lineage within the genus Maribacter. Strain KJ4T was most closely related to Maribacter orientalis KMM 3947T with 97.4% 16S rRNA gene sequence similarity. On the basis of phenotypic, chemotaxonomic and molecular features, strain KJ4T clearly represents a novel species of the genus Maribacter, for which the name Maribacter lutimaris sp. nov. is proposed. The type strain is KJ4T (=KACC 16438T=JCM 31154T).

A genome-wide transcriptional analysis of Alteromonas naphthalenivorans SN2 was performed to investigate its ecophysiological behavior in contaminated tidal flats and seawater. The experimental design mimicked these habitats that either added naphthalene or pyruvate; tidal flat-naphthalene (TF-N), tidal flat-pyruvate (TF-P), seawater-naphthalene (SW-N), and seawater-pyruvate (SW-P). The transcriptional profiles clustered by habitat (TF-N/TF-P and SW-N/SW-P), rather than carbon source, suggesting that the former may exert a greater influence on genome-wide expression in strain SN2 than the latter. Metabolic mapping of cDNA reads from strain SN2 based on KEGG pathway showed that metabolic and regulatory genes associated with energy metabolism, translation, and cell motility were highly expressed in all four test conditions, probably highlighting the copiotrophic properties of strain SN2 as an opportunistic marine r-strategist. Differential gene expression analysis revealed that strain SN2 displayed specific cellular responses to environmental variables (tidal flat, seawater, naphthalene, and pyruvate) and exhibited certain ecological fitness traits -- its notable PAH degradation capability in seasonally cold tidal flat might be reflected in elevated expression of stress response and chaperone proteins, while fast growth in nitrogen-deficient and aerobic seawater probably correlated with high expression of glutamine synthetase, enzymes utilizing nitrite/nitrate, and those involved in the removal of reactive oxygen species.