nov., isolated from surface seawater of the Pacific Ocean

Two Gram-negative, non-spore-forming, non-motile, non-flagellated bacteria, designated strains D6T and DH64T, were isolated from surface water of the Pacific Ocean. For strain D6T, growth occurred at 10-40 °C, pH 5.5-9.0 and in the presence of 0-8.0 % NaCl (w/v). For strain DH64T, growth occurred at 10-40 °C, pH 5.5-8.5 and in the presence of 0.5-8.0 % NaCl (w/v). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strains D6T and DH64T both belonged to the genera Flagellimonas, with the highest sequence identities to Flagellimonas taeanensis JCM 17757T (98.2 %) and Flagellimonas marinaquae JCM 11811T (98.6 %), respectively. The 16S rRNA gene sequence identity between strains D6T and DH64T was 95.9 %. The average amino acid identity and digital DNA-DNA hybridization values between the two strains and the nearest phylogenetic neighbours were 66.7-93.3 % and 16.1-38.5 %, respectively. The major respiratory quinone of both strains was menaquinone-6. The major polar lipid was phosphatidylethanolamine. The major fatty acids were identified similarly as iso-C15 : 1 G, iso-C15 : 0 and iso-C17 : 0 3-OH. The genomic G+C contents of strains D6T and DH64T were determined to be 45.5 and 42.6 mol%, respectively. The combined genotypic and phenotypic data show that the strains represent two novel species within genera Flagellimonas, for which the names Flagellimonas baculiformis sp. nov. and Flagellimonas crocea sp. nov. are proposed, with type strains D6T (=MCCC M28982T=KCTC 92604T) and DH64T (=MCCC M28986T=KCTC 92975T).

nov., Isolated from the Surface Seawater of the Western Pacific Ocean

The Gram-negative marine bacterium GXY010T, which has been isolated from the surface seawater of the western Pacific Ocean, is aerobic, non-motile and non-flagellated. Strain GXY010T exhibits growth across a temperature range of 10-42 °C (optimal at 37 °C), pH tolerance from 7.0 to 11.0 (optimal at 7.5) and a NaCl concentration ranging from 1.0 to 15.0% (w/v, optimal at 5.0%). Ubiquinone-8 (Q-8) was the predominant isoprenoid quinone in strain GXY010T. The dominant fatty acids (>10%) of strain GXY010T were iso-C15:0 (14.65%), summed feature 9 (iso-C17:1ω9c and/or 10-methyl C16:0) (12.41%), iso-C17:0 (10.85%) and summed feature 3 (C16:1ω7c and/or C16:1ω6c) (10.41%). Phosphatidylethanolamine (PE), phosphatidylglycerol (PG), diphosphatidylglycerol (DPG), unidentifiable glycolipid (GL) and four non-identifiable aminolipids (AL1-AL4) were the predominant polar lipids of strain GXY010T. The genomic DNA G+C content was identified as a result of 48.0% for strain GXY010T. The strain GXY010T genome consisted of 2,766,857 bp, with 2664 Open Reading Frames (ORFs), including 2586 Coding sequences (CDSs) and 78 RNAs. Strain GXY010T showed Average Nucleotide Identity (ANI) values of 73.4% and 70.6% and DNA-DNA hybridization (DDH) values of 19.2% and 14.5% with reference species Pseudidiomarina tainanensis MCCC 1A02633T (=PIN1T) and Pseudidiomarina taiwanensis MCCC 1A00163T (=PIT1T). From the results of the polyphasic analysis, a newly named species, Pseudidiomarina fusca sp. nov. within the genus Pseudidiomarina, was proposed. The type strain of Pseudidiomarina fusca is GXY010T (=JCM 35760T = MCCC M28199T = KCTC 92693T).

nov., a methylphosphonate-decomposing bacterium isolated from surface seawater in the Xisha Islands, PR China

A Gram-stain-negative, facultative anaerobic, methylphosphonate-decomposing, motile by a polar flagellum and rod-shaped marine bacterium, designated S4B1T, was isolated from the surface seawater collected from the Yongle Atoll (Xisha Islands, PR China). The pairwise alignment showed the highest sequence similarity of 97.5 and 96.6 % to Vibrio aestuarianus subsp. cardii 12_122_3T3T and Vibrio atypicus HHS02T, respectively. Phylogenetic analysis based on 16S rRNA gene and the phylogenomic analysis of single-copy genes showed that strain S4B1T belonged to the genus Vibrio and formed a close branch with Vibrio qingdaonensis ZSDZ65T. Growth of strain S4B1T occurred at 4-30 °C (optimum, 28 °C), at pH 6.0-8.0 (optimum, pH 7.0) and in the presence of 2-7 % (w/v) NaCl (optimum, 3 %). The predominant fatty acids (>10 %) were C16 : 0, iso-C16 : 0 and summed feature 3 (C16 : 1  ω7c or/and C16 : 1  ω6c). The DNA G+C content of the assembled genomic sequence was 44.3 mol%. Average nucleotide identity (ANI) values between S4B1T and its reference species were lower than the threshold for species delineation (95-96 %), in which its highest ANI value with V. qingdaonensis ZSDZ65T was 87.0 %. In silico DNA-DNA hybridization further showed that strain S4B1T had less than 70 % similarity to its relatives. On the basis of the polyphasic evidence, strain S4B1T is proposed to represent a novel species of the genus Vibrio, for which the name Vibrio methylphosphonaticus sp. nov. is proposed. The type strain is S4B1T (=KCTC 92311T=MCCC 1K06168T).

Distribution Characteristics of Microplastics in Surface Seawater off the Yangtze River Estuary Section and Analysis of Ecological Risk Assessment

Microplastics are widespread in the oceans as a new type of pollutant. Due to the special geographical environment characteristics, the Yangtze River estuary region become hotspot for microplastics research. In 2017 and 2019, surface seawater microplastics samples were collected from five stations off the Yangtze River estuary during four seasons (spring, summer, autumn, and winter). The abundance and characteristics of microplastics in seawater were researched. The results showed that microplastics widely existed in surface seawater; the average abundance of microplastics in seawater was (0.17 ± 0.14) items/m3 (0.00561 ± 0.00462) mg/m3; and accounting for 80% of the total plastic debris, the abundance of microplastics was at moderately low levels compared to national and international studies. The particle size of most microplastics was between 1 mm to 2 mm, accounting for 36.1% of the total microplastics. The main shapes of microplastics were fiber, flake, and line, accounting for 39.5%, 28.4%, and 20.8%, respectively. Polypropylene, polyethylene terephthalate, and polyethylene were the main components of microplastics, accounting for 41.0%, 25.1%, and 24.9%, respectively. Yellow, green, black, and transparent were the most common colors, accounting for 21.9%, 19.6%, 16.5%, and 15.7%, respectively. This study shows that the spatial distribution of microplastics in the surface waters off the Yangtze River estuary shows a decreasing trend from nearshore to farshore due to the influence of land-based inputs, hydrodynamics, and human activities; the distribution of microplastics has obvious seasonal changes, and the level of microplastic pollution is higher in summer. The potential ecological risk of microplastics in the surface waters off the Yangtze River estuary is relatively small.

Vibrio sinus sp. nov., a marine bacterium isolated from coastal seawater

A Gram-straining-negative, facultatively anaerobic, motile by means of a polar flagellum and rod-shaped marine bacterium, designated S4M6^T, was isolated from surface seawater collected in Dongshan Bay (Fujian, PR China). Phylogenetic analysis based on 16S rRNA genes, phylogenomic analysis of single-copy gene families and whole genome data indicated that S4M6^T represented a member of the genus Vibrio. The closest phylogenetic relatives of S4M6^T were Vibrio marisflavi CGMCC 1.8994^T (97.8 % 16S rRNA gene sequence pairwise similarity), Vibrio variabilis LMG 25438^T (96.9 %), Vibrio gangliei SZDIS-1^T (96.2 %) and Vibrio aestivus M22^T (96.1 %). The growth of S4M6^T occurred at 15-35 °C (optimum 28 °C), pH 4.0-9.0 (optimum 5.0-7.0) and in the presence of 2-5 % (w/v) NaCl (optimum 3 %). The predominant fatty acids (>10 %) are C_16 : 0, summed feature 3 (C_16 : 1ω7c and/or C_{16 :  1}ω6c) and summed feature 8 (C_18 : 1ω7c and/or C_{18 :  1}ω6c). The DNA G+C content of the assembled genomic sequences was 43.4 % for S4M6^T. Average nucleotide identity (ANI) values between S4M6^T and the reference species were lower than the threshold for species delineation (95-96 %); in silico DNA-DNA hybridization further indicated that S4M6^T had less than 70 % similarity to its relatives. On the basis of the polyphasic evidence, strain S4M6^T is proposed to represent a novel species of the genus Vibrio, for which the name Vibrio sinus sp. nov. is proposed. The type strain is S4M6^T (= KCTC 92312^T= MCCC 1K06167^T).

nov., two marine bacteria isolated from surface seawater of Qingdao

Two Gram-stain-negative, oxidase-positive, facultative anaerobic and rod-shaped motile bacteria, designated strains ZSDZ34 and ZSDE26, were isolated from offshore surface seawater collected near Qingdao. Phylogenetic analysis based on 16S rRNA gene sequences placed ZSDE26^T and ZSDZ34^T within the genus Vibrio, family Vibrionaceae, class Gammaproteobacteria. Strain ZSDE26^T was most closely related to Vibrio gallaecicus VB 8.9^T with 97.3 % sequence similarity, whereas ZSDZ34^T was most closely related to Vibrio aestuarianus subsp. cardii DSM 109723^T with 97.8 % sequence similarity. Strain ZSDE26^T grew with 1-5 % (w/v) NaCl (optimum, 4 %), at 16-28 °C (optimum, 28 °C) and at pH 6.0-9.0 (optimum, pH 7.0). Growth of strain ZSDZ34^T occurred with 1-6 % (w/v) NaCl (optimum, 3 %), at 16-37 °C (optimum, 28 °C) and at pH 6.0-9.0 (optimum, pH 7.0). Both strains shared the same major fatty acid components (more than 10 % of total fatty acids) of summed feature 3 (C_16 : 1 ω7c and/or C_16 : 1 ω6c), summed feature 8 (C_18 : 1 ω7c and/or C_18 : 1 ω6c) and C_16 : 0. Additionally, strain ZSDZ34^T contained a higher proportion of iso-C_16 : 0. The DNA G+C contents of strains ZSDE26^T and ZSDZ34^T were 42.8 and 44.5 mol%, respectively. On the basis of the results of polyphasic analysis, ZSDE26^T and ZSDZ34^T are considered to represent novel species within the genus Vibrio, for which the names Vibrio amylolyticus sp. nov. (type strain, ZSDE26^T=KCTC 82890^T=MCCC 1K06290^T) and Vibrio gelatinilyticus sp. nov. (type strain, ZSDZ34^T=KCTC 82888^T=MCCC 1K06292^T) are proposed, respectively.

nov., isolated from surface seawater of the Western Pacific Ocean

Zunongwangia is a group of marine bacteria with important industrial application potential and ecological functions. In this study, a Gram-stain-negative, rod-shaped, non-motile, strictly aerobic and bright yellow pigmented bacterial strain within this genus, designated C2-37M9^T, was isolated from a surface seawater sample from the Philippine Basin in the Western Pacific Ocean. Strain C2-37M9^T grew at 10-44 °C (optimum, 28-30 °C), pH 6-9 (pH 7) and in the presence of 0-12 % NaCl (w/v; 2-3 %). Phylogenetic analysis based on 16S rRNA gene sequences indicated that it belonged to the genus Zunongwangia and had 95.7-98.7 % sequence similarity to all type strains of this genus, with the highest value corresponding to Zunongwangia profunda (98.7 %). Digital DNA-DNA hybridization, average nucleotide identity and average amino acid identity values between strain C2-37M9^T and all valid type strains were 27.5-32.3, 83.8-86.7 and 86.9-89.0 %, respectively. The principal fatty acids (>5 %) were iso-C_15 : 0, iso-C_17 : 0 3-OH, anteiso-C_15 : 0, summed feature 9 (C_16 : 0 10-methyl and/or iso-C_17 : 1  ω9c), iso-C_15 : 1 G and summed feature 3 (C_16 : 1  ω6c and/or C_16 : 1  ω7c). The predominant respiratory quinone was MK-6. The polar lipids were one phosphatidylethanolamine, two unknown glycolipids, three unidentified aminolipids and six unidentified lipids. The genomic DNA G+C content of strain C2-37M9^T was 36.7 mol%. Based on phylogenetic results and genomic-based relatedness indices, as well as phenotypic and genotypic characteristics, strain C2-37M9^T represents a novel species within the genus Zunongwangia, for which the name Zunongwangia pacifica sp. nov. is proposed. The type strain is C2-37M9^T (=MCCC M21534^T=KCTC 82852^T).

[Diversity and community characteristics of organic phosphate-mineralizing bacteria in the sea area between Minjiang Estuary to Pingtan.]

Microbial mineralization of organic phosphorus is an important component of marine phosphorus cycle. The research on organic phosphate-mineralizing bacteria (OPB) is helpful to reveal microbial driving mechanism of organic phosphorus mineralization in eutrophic sea area. The diversity and community characteristics of OPB were examined by Illumina high-throughput sequencing using the primer sets phoX in the sea area between Minjiang Estuary to Pingtan in April (spring) and July (summer) 2019. The results showed that the Shannon index of OPB in the surface seawater samples ranged from 3.21 to 7.91, and that the diversity at each station was greater in spring than that in summer. Shannon index of OPB in the sediment samples ranged from 2.04 to 8.70, which was greater in summer than that in spring. Shannon index of OPB in surface seawater of each station was higher than that of sediment in spring, while it was in adverse in summer. Nine phyla of OPB were detected in surface seawater, with Proteobacteria and Cyanobacteria being the most abundant. Tweleve phyla of OPB were detected in the sediments, with Proteobacteria and Bacteroidetes being the most dominant. OPB community composition at the genus level showed obvious spatio-temporal variation. Leisingera, Phaeobacter, Thalassococcus, and Pseudomonas were the major genera in the seawater in spring, while Synechococcus, Halioglobus, Roseovarius, Phaeo-bacter, Sulfitobacter, and Hyphomonas were the major genera detected in summer. Leisingera, Phaeobacter, Vibrio, and Sulfitobacter were major genera in the sediment in spring, while Azospirillum, Aminobacter, Sulfurifustis, Burkholderia, and Thiohalobacter were the major genera in summer. A large number of unclassified OPB were detected in both surface seawater and sediment. The redundancy analysis results showed that dissolved oxygen, water temperature, pH, dissolved inorganic nitrogen, NO₂^--N, and NO₃^--N had great influences on community distribution of OPB in the surface seawater. The abundant OPB in the surface seawater and sediment might play an important role in phosphorus cycle in this sea area.

[Concentration Levels and Potential Ecological Risks of Current Use Pesticides in the Surface Seawater of Typical Liaoning Sea Areas]

Fourteen current-use pesticides (CUPs) in the surface seawaters of the typical Liaoning sea areas were analyzed using HPLC-MS/MS. The concentrations, distribution, and ecological risks were studied, as well as their source appointments using principal component analysis (PCA). The results revealed that seven types of CUPs were detected in the surface seawaters of the typical Liaoning sea areas. The total concentrations of these CUPs ranged from 16.7 ng·L^-1 to 176.1 ng·L^-1. The samples with high concentrations were collected mostly from the estuary, and the concentrations of CUPs in the western Liaodong Bay were generally higher than those in the northeastern Yellow Sea. Atrazine and triadimenol were the predominant CUPs, and their contribution rates accounted for 56.0% and 34.5%, respectively. The PCA results indicated that six types of CUPs might be caused by the runoff from farmlands and the wastewater discharge from the chemical pesticide factory, and fruit planting could be a substantial contributor to the single component acetochlor. Atrazine and acetochlor posed medium-high ecological risks to the microalgae, while all the seven types of CUPs showed relatively lower risks to invertebrates and fish.

Vibrio agarilyticus sp. nov., an agar-digesting marine bacterium isolated from coastal seawater in Daya Bay (Guangdong, China)

A Gram-strain-negative, facultatively anaerobic, motile, rod-shaped and flagellated marine bacterium, designated SM6^T, was isolated from surface seawater collected in Daya Bay (Guangdong, China). Phylogenetic analysis based on 16S rRNA gene sequences, multilocus sequence analysis, phylogenomic analysis of single-copy gene families and whole genome data showed that strain SM6^T belonged to the genus Vibrio. The closest phylogenetic relatives of SM6^T were Vibrio plantisponsor MSSRF60^T (97.38 % 16S rRNA gene sequence pairwise similarity), Vibrio variabilis R-40492^T (97.27 %), Vibrio aestuarianus ATCC 35048^T (97.21 %) and Vibrio sagamiensis LC2-047^T (97.3 %). Growth of strain SM6^T occurred at 10-45 °C (optimum 30 °C), at pH 6.0-9.0 (optimum 6.0) and in the presence of 0-10 % (w/v) NaCl (optimum 3-8 %). The predominant fatty acids (>10 %) were summed feature 3 (C_{16 : 1} ω7c or/and C_{16 : 1} ω6c), C_{16 : 0} and summed feature 8 (C_{18 : 1} ω7c or/and C_{18 : 1} ω6c). The DNA G+C content of the assembled genomic sequences was 47.37 % for strain SM6^T. Average nucleotide identity values between SM6^T and its reference species were lower than the threshold for species delineation (95-96 %); in silico DNA-DNA hybridization further showed that the strains shared less than 70 % similarity. On the basis of evidence from the present polyphasic study, strain SM6^T is considered to represent a novel species of the genus Vibrio, for which the name Vibrio agarilyticus sp. nov. is proposed. The type strain is SM6^T (=KCTC 82076^T=MCCC 1K04327 ^T).

nov., an agar-digesting marine bacterium isolated from surface seawater

A Gram-stain-negative, aerobic, gliding, reddish-orange-coloured, rod-shaped strain, designated SR4^T, was isolated from surface seawater sampled at Luhuitou fringing reef (South China Sea). Phylogenetic analyses based on the 16S rRNA gene, phylogenomic analysis of single-copy gene families and whole genome data affiliated it to the genus Flammeovirga. It was most closely related to Flammeovirga yaeyamensis NBRC 100898^T (97.99 % 16S rRNA gene similarity). The genome average nucleotide identity and DNA-DNA relatedness values between strain SR4^T and its reference strains were less than 74.2 and 16.3 %, respectively. Growth occurred at 20-35 °C (optimum, 28 °C), pH 6.0-9.0 (optimum, pH 7.0) and in the presence of 1-6 % (w/v) NaCl (optimum, 2-4 %). The dominant fatty acids were C_16 : 0, iso-C_15 : 0 and C_20 : 4  ω6,9,12,15c. The polar lipid profile of strain SR4^T comprised phosphatidylethanolamine, two glycolipids, two aminophospholipids and three unidentified lipids. The major respiratory quinone was MK-7. The DNA G+C content of strain SR4^T was 34.20 mol%. On the basis of the polyphasic evidence, strain SR4^T is proposed as representing a novel species of the genus Flammeovirga, for which the name Flammeovirga agarivorans sp. nov. is proposed. The type strain is SR4^T (=KCTC 82075^T=MCCC 1A17137^T).

nov., isolated from surface seawater

Two Gram-stain-negative, short rod-shaped and non-flagellated strains, designated 17-4A^T and L52-1-41, were isolated from the surface seawater of the Indian Ocean and South China Sea, respectively. The 16S rRNA genes of the two strains shared sequence similarity of 99.45 %. Strain 17-4A^T shared the highest 16S rRNA gene similarity of 98.02 % with Pusillimonas caeni EBR-8-1^T, followed by Pusillimonas noertemannii BN9^T (97.47 %), Pusillimonas soli MJ07^T (96.93 %), Parapusillimonas granuli Ch07^T (96.68 %), Pusillimonas ginsengisoli DCY25^T (96.65 %), Eoetvoesia caeni PB3-7B^T (96.63 %), Paracandidimonas caeni 24^T (96.34 %), Castellaniella defragrans 54Pin^T (96.28 %) and Pusillimonas harenae B201^T (96.05 %). L52-1-41 shared the highest 16S rRNA gene similarity of 97.74 % with Pusillimonas caeni EBR-8-1^T, followed by Pusillimonas noertemannii BN9^T (97.47 %), Pusillimonas soli MJ07^T (96.65 %), Parapusillimonas granuli Ch07^T (96.41 %), Pusillimonas ginsengisoli DCY25^T (96.37 %), Eoetvoesia caeni PB3-7B^T (96.35 %), Pusillimonas harenae B201^T (96.28 %), and Paracandidimonas caeni 24^T (96.06 %). The results of phylogenetic analyses indicated that 17-4A^T and L52-1-41 formed a stable, distinct and highly supported lineage affiliated to the genus Pusillimonas. The results of the digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) analyses indicated that they represented a single species. They featured similar genomic DNA G+C contents of 53.2-53.4 mol%. Activities of catalase and oxidase were negative for both strains. The fatty acids patterns of 17-4A^T and L52-1-41 were most similar, mostly comprised of C_16 : 0, C_17 : 0cyclo, C_18 : 0, C_18 : 1ω9c and summed feature 8 (C_18 : 1ω7c and/or C_18 : 1  ω6c). The major polar lipids of the two strains were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and unidentified aminolipids. The respiratory quinone of the two strains was Q-8. Hence, on the basis of the phenotypic, chemotaxonomic and genotypic data presented in this study, we proposed the classification of both strains as representatives of a novel species named Pusillimonas maritima sp. nov., with the type strain 17-4A^T (=MCCC 1A12670^T=KCTC 62121^T=NBRC 113794^T), and another strain L52-1-41 (=MCCC 1A05046=KCTC 52313).

nov., a marine bacterium in the family Rhodobacteraceae isolated from surface seawater of Xiamen Port, China

A Gram-stain-negative Rhodobacterales strain, designated as FSX-11^T, was isolated from surface seawater of Xiamen port in China. Strain FSX-11^T showed less than 96.5 % 16S rRNA gene sequence similarity to the type strains of species with validly published names. Phylogenetic analysis based on 16S rRNA gene sequences revealed that the novel isolate formed a distinct monophyletic clade within the family Rhodobacteriaceae and clustered distantly with the genera Thalassobius and Marivita. Cells of strain FSX-11^T were non-motile, oval-shaped and facultative anaerobic. Optimal growth occurred at 20-30 °C, at pH 7.0-8.0 and in the presence of 2-3 % NaCl (w/v). The major respiratory quinone was ubiquinone-10. Summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c), 11-methyl C18 : 1ω7c and C16 : 0 were the major fatty acids. The DNA G+C content of strain FSX-11^T was 58.7 mol%. On the basis of phylogenetic analysis, phenotypic and chemotaxonomic characteristics and 16S rRNA gene signature nucleotide patterns, strain FSX-11^T represents a novel species in a novel genus within the family Rhodobacteraceae, for which the name Litorivita pollutaquae gen. nov., sp. nov. is proposed. The type strain is FSX-11^T (=JCM 32715^T=MCCC 1K03503^T).

nov., isolated from surface seawater

Two novel marine bacteria, designated strains CSC3H3^T and CSC1P2, were isolated from surface seawater of the South China Sea. Both strains were Gram-negative, oxidase-positive, catalase-positive, curved rods and motile. They grew at 10-40 °C, pH 5-10 and in the presence of 0-15 % (w/v) NaCl. Their 16S rRNA gene sequences were identical to each other. Phylogenetic analysis based on 16S rRNA gene sequences indicated that they belong to the genus Thalassospira, and shared 97.5-98.3 % sequence similarity to all other validly type strains of the genus Thalassospira, and the highest similarity was to the type strain Thalassospira povalilyticaZumi 95^T (98.3 %), followed by Thalassospira australica NP3b2^T (98.2 %). The digital DNA-DNA hybridization value between the two strains was 80.4 %, while the values with T. povalilyticaZumi 95^T and T. australica NP3b2^T were only 20.5-20.7 % and 20.4-20.5 %, respectively. The two strains possess similar major cellular fatty acids including C18 : 1ω7c, C16 : 0, C19 : 0ω8c cyclo, C18 : 1 2-OH and C17 : 0 cyclo. The G+C contents of the chromosomal DNA of strains CSC3H3^T and CSC1P2 were 54.6 and 54.5 mol%, respectively. The major respiratory quinone was ubiquinone 10. Phosphatidylethanolamine, phosphatidylglycerol and several unidentified phospholipids, aminolipid and lipids were present in both strains. Based on phenotypic and genotypic characteristics, the two strains represent a novel species within the genus Thalassospira, for which the name Thalassospira marina sp. nov. is proposed. The type strain is CSC3H3^T (=MCCC 1A11786^T=KCTC 62333^T).

nov., isolated from surface seawater

A Gram-stain-negative, aerobic, short rod-shaped bacterium with a single polar flagellum, designated strain S27-2^T, was isolated from surface seawater from the Indian Ocean. Growth was observed in 0-12.0 % (w/v) NaCl with an optimum of 0.5-2.0 % (w/v) NaCl, pH 6.0-9.0 with an optimum of pH 7.0, and growth temperature of 10-41 °C with an optimum of 25-37 °C. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain S27-2^T belonged to the family Alteromonadaceae and formed a distinct lineage with the type strain of Pseudobowmanella zhangzhouensis. Levels of 16S rRNA gene sequence similarity between strain S27-2^T and members of related genera included in the trees ranged from 86.7 to 93.8 %. Strain S27-2^T contained Q-8 as the predominant ubiquinone. The principal fatty acids (>10 %) were C16 : 0 (22.1 %), C16 : 1ω7c/ω6c (22.7 %) and C18 : 1ω7c/ω6c (20.1 %). The polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, one unidentified phospholipid and two unknown lipids. The G+C content of strain S27-2^T was 43.7 mol%. On the basis of the polyphasic taxonomic evidence presented in this study, strain S27-2^T should be classified as a novel species in a new genus within the family Alteromonadaceae, for which the name Neptunicella marina gen. nov., sp. nov. is proposed, with the type strain S27-2^T (= KCTC52335^T=MCCC 1A02149^T).

[Distribution and Sources of n-alkanes in Surface Seawater of Jiaozhou Bay]

Hydrocarbons emitted by human activities probably constitute the largest class of contaminants that are present in coastal areas, because of widespread use of fossil fuels for power generation and logistics, and accidental spillages. The chemical composition of hydrocarbon mixtures found in the marine environment allowed the identification of relative contributions of different natural and anthropogenic sources. Identification of these hydrocarbons, especially n-alkanes, could act as tracers for the possible sources. To evaluate n-alkanes concentrations with emphasis on source analysis, surface water without visible oil was collected from the cruise in April 2016. Determination and quantification were performed by solvent extraction and gas chromatography-mass spectrometry. Various molecular diagnostic parameters were used to assess the contribution of different sources and origin of n-alkanes in surface seawater of Jiaozhou Bay. Concentrations of total dissolved n-alkanes(C₁₁-C₃₇) were between 1.756-39.09 μg·L^-1 with a high carbon number predominance profile without odd-even carbon number preference. The n-alkane concentrations varied spatially depending on the distance away from main input sources and the ability of water exchange. It was at a higher concentration in the northeast and west coastal areas, as well as the mouth of Jiaozhou Bay. And concentrations were relatively lower in the inner area and outside of Jiaozhou Bay. In the sea area with strong water exchange, concentrations of total n-alkanes were around 2.196 μg·L^-1, which could be considered as the environmental background level of n-alkanes in Jiaozhou Bay. Those n-alkanes were dominated with C₂₄, with a slightly odd carbon number preference in low carbon n-alkanes and an even carbon number preference in high carbon n-alkanes. The values of CPI for the whole range of n-alkanes series, low carbon n-alkanes, and high carbon n-alkanes were 0.949, 1.026, and 0.980, respectively. Diagnostic indices and curves indicated that the dominant inputs of those n-alkanes were from marine biogenic input such as algae and marine bacteria. The concentration profiles of n-alkanes in other areas were characterized by no odd-even predominance in the range of C₂₁-C₃₃ with peaks center at C₂₄ which were indicative of anthropic contributions as emission sources. N-alkanes dominating with anthropic sources comprised a high proportion(83.7%) of total n-alkanes. Activities of harbors and ships were the main contributors of Jiaozhou Bay n-alkanes. Physical processes, such as evaporation and dilution, were the principal weathering mechanisms. Because of its sufficient environmental capacity, Jiaozhou Bay was still moderately contaminated with petroleum.

Diversity of bacterioplankton in the surface seawaters of Drake Passage near the Chinese Antarctic station

The determination of relative abundances and distribution of different bacterial groups is a critical step toward understanding the functions of various bacteria and its surrounding environment. Few studies focus on the taxonomic composition and functional diversity of microbial communities in Drake Passage. In this study, marine bacterioplankton communities from surface seawaters at five locations in Drake Passage were examined by 16S rRNA gene sequence analyses. The results indicated that psychrophilic bacteria were the most abundant group in Drake Passage, and mainly made up of Bacillus, Aeromonas, Psychrobacter, Pseudomonas and Halomonas. Diversity analysis showed that surface seawater communities had no significant correlation with latitudinal gradient. Additionally, a clear difference among five surface seawater communities was evident, with 1.8% OTUs (only two) belonged to Bacillus consistent across five locations and 71% OTUs (80) existed in only one location. However, the few cosmopolitans had the largest population sizes. Our results support the hypothesis that the dominant bacterial groups appear to be analogous between geographical sites, but significant differences may be detected among rare bacterial groups. The microbial diversity of surface seawaters would be liable to be affected by environmental factors.

Complete genome sequence of Thalassolituus oleivorans R6-15, an obligate hydrocarbonoclastic marine bacterium from the Arctic Ocean

Strain R6-15 belongs to the genus Thalassolituus, in the family Oceanospirillaceae of Gammaproteobacteria. Representatives of this genus are known to be the obligate hydrocarbonoclastic marine bacteria. Thalassolituus oleivorans R6-15 is of special interest due to its dominance in the crude oil-degrading consortia enriched from the surface seawater of the Arctic Ocean. Here we describe the complete genome sequence and annotation of this strain, together with its phenotypic characteristics. The genome with size of 3,764,053 bp comprises one chromosome without any plasmids, and contains 3,372 protein-coding and 61 RNA genes, including 12 rRNA genes.

Effects of Japan Sea Proper Water on the growth ofLegionella pneumophila, Escherichia coli, andStaphylococcus aureus

OBJECTIVE

To assess whetherLegionella pneumophila serogroup 1 and serogroup 6,Escherichia coli, andStaphylococcus aureus can survive in Japan Sea Proper Water (JSPW).

METHODS

The inhibitory effects of JSPW, surface seawater (SSW), phosphate buffer solution with 3.5% NaCl of pH 7.0 (3.5% NaCIPBS), and the 10(2)- and 10(4)-fold dilute solutions with purified water or phosphate buffer solution of pH 7.0, and purified water were investigated. Survival cells were counted immediately after the water and the bacteria were mixed, and at 1,3,5, and 7 days after incubation at 37°C. If the number of surviving cells was decreased more than 2 log units compared with the starting value, we judged the medium to have had an inhibitory effect on the growth of the bacteria.

RESULTS

The survival cells of the bacteria in JSPW had decreased more than 2 log units compared with the starting value at 1 day after incubation. After 1 day of incubation, the cells ofLegionella pneumophila serogroup 6 andStaphylococcus aureus were found to have decreased more than 2 log units in purified water (PW) used as a control. Furthermore,Legionella pneumophila serogroup 1 in the 10(2)-fold dilute solution of JSPW was only 1.04 log units lower than the starting value at 7 days after incubation. In the 10(2)- and 10(4)-fold dilute solutions of JSPW,Escherichia coli survived for 7 days after incubation. These results were almost similar to the results in SSW and 3.5% NaCIPBS.

CONCLUSIONS

The present findings demonstrate thatLegionella pneumophila serogroup 1 andEscherichia coli cannot survive in undiluted JSPW for over a day at 37°C, suggesting the inhibitory effects may be due to the sodium chloride contained in JSPW.