Sphingomicrobium sediminis sp. nov., isolated from marine sediment in the Republic of Korea.

A Gram-stain-negative, rod-shaped, bright-orange coloured bacterium without flagellum, designated as strain GRR-S6-50T, was isolated from a tidal flat of Garorim bay, Taean-gun, Chungcheongbuk-do, Republic of Korea. Cells grew aerobically at 20-37 °C (optimum, 30 °C), pH 7.0-10.0 (optimum, pH 7.0) and with 1-5 % (w/v) NaCl (optimum, 3 %). The 16S rRNA gene sequence analysis demonstrated that strain GRR-S6-50T was closely related to Sphingomicrobium aestuariivivum AH-M8T with a sequence similarity of 97.80 % followed by Sphingomicrobium astaxanthinifaciens CC-AMO-30BT (97.44 %), Sphingomicrobium marinum CC- AMZ-30MT (97.16 %), Sphingomicrobium arenosum CAU 1457T (96.37 %), Sphingomicrobium flavum CC-AMZ-30NT (95.31 %) and Sphingomicrobium lutaoense CC-TBT-3T (95.23 %). The average nucleotide identity and digital DNA-DNA hybridization values with related strains ranged from 74.5 to 77.3% and 21.1 to 35.0 %, respectively. The G+C content of strain GRR-S6-50T was 63.30 mol%. The strain has ubiquinone-10 as the predominant respiratory quinone and the major fatty acids were C18 : 3 ω6c (54.57 %) and C17 : 1 ω6c (10.58 %). The polar lipids consisted of phosphatidylethanolamine, phosphatidylglycerol, three unidentified lipids and one glycolipid. On the basis of the results of phylogenetic, phenotypic and chemotaxonomic studies, strain GRR-S6-50T is regarded to represent a novel species within the genus Sphingomicrobium, for which the name Sphingomicrobium sediminis sp. nov. (KACC 22562T=KCTC 92123T=JCM 35084T) is proposed.

Tenacibaculum tangerinum sp. nov., isolated from a tidal flat sediment.

An orange-coloured bacterium, designated as strain GRR-S3-23T, was isolated from a tidal flat sediment collected from Garorim Bay, Chuncheongbuk-do, Republic of Korea. Cells of GRR-S3-23T were aerobic, Gram-stain-negative, rod-shaped and motile. GRR-S3-23T grew at 18-40 °C (optimum, 30 °C), pH 7.0-9.0 (optimum, pH 7.0) and with 2-4 % NaCl (optimum, 2-3 % w/v). Results of 16S rRNA gene sequence analysis indicated that GRR-S3-23T was closely related to Tenacibaculum aiptasiae a4T (97.6 %), followed by Tenacibaculum aestuarii SMK-4T (97.5 %), Tenacibaculum mesophilum MBIC 1140T (97.4 %), Tenacibaculum singaporense TLL-A2T (97.3 %), Tenacibaculum crassostreae JO-1T (97.2 %),and Tenacibaculum sediminilitoris YKTF-3T (97.1 %). The average amino acid identity values between GRR-S3-23T and the related strains were 86.8-72.8 %, the average nucleotide identity values were 83.3-74.1 %, and the digital DNA-DNA hybridization values were 27.0-19.6 %. GRR-S3-23T possessed menaquinone-6 (MK-6) as major respiratory quinone and had summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c, 20.6 %) and iso-C15 : 1G (10.8 %) as major fatty acids (>10.0 %). The polar lipid profiles of GRR-S3-23T contained phosphatidylethanolamine, one unidentified aminolipid, one unidentified aminophospholipid, three unidentified lipids, one unidentified glycolipid and four unidentified phospholipids. The DNA G+C content of GRR-S3-23T was 33.7%. On the basis of the results of the polyphasic analysis involving phylogenetic, phylogenomic, physiological and chemotaxonomic analyses described in this study, GRR-S3-23T is considered to represent a novel species within the genus Tenacibaculum, for which the name Tenacibaculum tangerinum is proposed. The type strain is GRR-S3-23T (=KCTC 102029T=KACC 23271T=JCM 36353T).

Effect-Directed Analysis Combined with Nontarget Screening to Identify Unmonitored Toxic Substances in the Environment.

Effect-directed analysis (EDA) combined with nontarget screening (NTS) has established a valuable tool for the identification of unmonitored toxic substances in environmental samples. It consists of three main steps: (1) highly potent fraction identification, (2) toxicant candidate selection, and (3) major toxicant identification. Here, we discuss the methodology, current status, limitations, and future challenges of EDA combined with NTS. This method has been applied successfully to various environmental samples, such as sediments, wastewater treatment plant effluents, and biota. We present several case studies and highlight key results. EDA has undergone significant technological advancements in the past 20 years, with the establishment of its key components: target chemical analysis, bioassays, fractionation, NTS, and data processing. However, it has not been incorporated widely into environmental monitoring programs. We provide suggestions for the application of EDA combined with NTS in environmental monitoring programs and management, with the identification of further research needs.

Identification of Mid-Polar and Polar AhR Agonists in Cetaceans from Korean Coastal Waters: Application of Effect-Directed Analysis with Full-Scan Screening.

Major aryl hydrocarbon receptor (AhR) agonists were identified in extracts of blubber, liver, and muscle from six long-beaked common dolphins (Delphinus capensis) and one fin whale (Balaenoptera physalus) collected from Korean coastal waters using effect-directed analysis. Results of the H4IIE-luc bioassay indicated that the polar fractions of blubber and liver extracts from the fin whale exhibited relatively high AhR-mediated potencies. Based on full-scan screening with high-resolution mass spectrometry, 37 AhR agonist candidates, spanning four use categories: pharmaceuticals, pesticides, cosmetics, and natural products, were selected. Among these, five polar AhR agonists were newly identified through toxicological confirmation. Concentrations of polar AhR agonists in cetaceans were tissue-specific, with extracts of blubber and liver containing greater concentrations than muscle extracts. Polar AhR agonists with great log KOA values (>5) were found to biomagnify in the marine food chain potentially. Polar AhR agonists contributed 8.9% of the observed AhR-mediated potencies in blubber and 49% in liver. Rutaecarpine and alantolactone contributed significantly to the total AhR-mediated potencies of blubber, whereas hydrocortisone was a major AhR contributor in the liver of the fin whale. This study is the first to identify the tissue-specific accumulation of polar AhR agonists in blubber and liver extracts of cetaceans.

Halomonas getboli sp. nov., a halotolerant bacteria isolated from a salt flat.

A novel Gram-stain-negative, rod-shaped, cream-coloured, motile, halotolerant bacterium, designated as YJPS3-2T, was isolated from saltern sediment of the Yellow sea in Yongyu-do, Republic of Korea. Strain YJPS3-2T grew at pH 5.0-10.0 (optimum, pH 7.0), 4-40 °C (optimum, 30 °C) and with 1-15% (w/v) NaCl (optimum 3 %). The 16S rRNA gene sequence analysis indicated that strain YJPS3-2T was closely related to those of Halomonas halophila F5-7T (98.75 %), Halomonas salina F8-11T (98.74 %), Halomonas smyrnensis AAD6T (98.66 %), Halomonas organivorans G-16.1T (98.34 %), Halomonas koreensis SS20T (97.98 %) and Halomonas beimenensis NTU-107T (96.93 %). The average nucleotide identity and digital DNA-DNA hybridization values between YJPS3-2T and related type strains were 86.9-91.6 % and 32.0-44.8 %. Strain YJPS3-2T was characterized as having Q-9 as the predominant respiratory quinone and the principal fatty acids (>10 %) were C16 : 0 (31.4 %), C19 : 0 ω8c cyclo (16.3 %), C17 : 0 cyclo (11.9 %) and C12 : 0 3-OH (10.4 %). The polar lipids consisted of phosphatidylcholine, diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol. The DNA G+C content of strain YJPS3-2T is 68.1mol %. Based on the polyphasic taxonomic evidence presented in this study, YJPS3-2T should be classified as representing a novel species within the genus Halmonas, for which name Halomonas getboli is proposed, with the type strain YJPS3-2T (= KCTC 92124T=KACC 22561T=JCM 35085T).

Aurantiacibacter sediminis sp. nov., a marine bacterium isolated from a tidal flat.

A yellow-coloured bacterium, designated as strain JGD-13T, was isolated from a tidal flat in the Republic of Korea. Cells were Gram-stain-negative, aerobic, non-flagellated and rod-shaped. Growth was observed at 4-42 °C (optimum, 30 °C), at pH 6.0-12.0 (pH 7.0-8.0) and at 1-7 % (w/v) NaCl concentration (3 %). The 16S rRNA gene sequence analysis indicated that strain JGD-13T was closely related to Aurantiacibacter gangjinensis K7-2T with a sequence similarity of 98.2 %, followed by Aurantiacibacter aquimixticola JSSK-14T (98.1 %), Aurantiacibacter atlanticus s21-N3T (97.6 %), Aurantiacibacter zhengii V18T (97.6 %) and Aurantiacibacter luteus KA37T (97.5 %). The average nucleotide identity and digital DNA-DNA hybridization values with related strains were 70.3-76.2 % and 18.5-20.3 %. The genomic DNA G+C content was 60.2 mol%. Phylogenetic analysis using the maximum-likelihood method showed that strain JGD-13T formed a clade with A. aquimixticola JSSK-14T and A. gangjinensis K7-2T. The major fatty acids were summed feature 8 (39.7 %) and C17 : 1 ω6c (14.4 %). The predominant respiratory quinone was ubiquinone-10. The polar lipids were phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, one sphingoglycolipid and three unidentified lipids. On the basis of phylogenetic, phenotypic and chemotaxonomic characteristics, strain JGD-13T represents a novel species within the genus Aurantiacibacter, for which the name Aurantiacibacter sediminis JGD-13Tsp. nov. is proposed. The type strain is JGD-13T (=KCTC 72892T=KACC 21676T=JCM 33995T).

Molecular Characterization of Estrogen Receptor Agonists during Sewage Treatment Processes Using Effect-Directed Analysis Combined with High-Resolution Full-Scan Screening.

Endocrine-disrupting potential was evaluated during the sewage treatment process using in vitro bioassays. Aryl hydrocarbon receptor (AhR)-, androgen receptor (AR)-, glucocorticoid receptor (GR)-, and estrogen receptor (ER)-mediated activities were assessed over five steps of the treatment process. Bioassays of organic extracts showed that AhR, AR, and GR potencies tended to decrease through the sewage treatment process, whereas ER potencies did not significantly decrease. Bioassays on reverse-phase high-performance liquid chromatography fractions showed that F5 (log KOW 2.5-3.0) had great ER potencies. Full-scan screening of these fractions detected two novel ER agonists, arenobufagin and loratadine, which are used pharmaceuticals. These compounds accounted for 3.3-25% of the total ER potencies and 4% of the ER potencies in the final effluent. The well-known ER agonists, estrone and 17ß-estradiol, accounted for 60 and 17% of the ER potencies in F5 of the influent and primary treatment, respectively. Fourier transform ion cyclotron resonance mass spectrometry analysis showed that various molecules were generated during the treatment process, especially CHO and CHOS (C: carbon, H: hydrogen, O: oxygen, and S: sulfur). This study documented that widely used pharmaceuticals are introduced into the aquatic environments without being removed during the sewage treatment process.

Decolorization of safranin using Fissidens species and its ecotoxicological assessments: An in vitro and in silico approach.

Decolorization of safranin was investigated using Fissidens species in a batch system under optimized conditions. The decolorization efficiency was improved by optimizing the conditions such as initial pH (3-9), temperature (25-45 °C), initial dye concentration (10-50 mg/L), biosorbent dosage (100-500 mg/L) and contact time (1-6 days). Maximum decolorization (95%) was recorded at initial pH of 6 with dye concentration of 20 mg/L, biosorbent dosage of 200 mg/L at 30 °C and contact time of 2 days. Desorption studies revealed 0.1 N NaOH as the best desorbing agent with 92% recovery on third day. Experimental data well fitted to Langmuir isotherm and Pseudo-second order kinetic model. The negative values of ΔGo and positive value of ΔSo and ΔHo indicates that the reaction is spontaneous, favorable and endothermic. The biosorbent - dye interactions were confirmed using UV-Vis, FT-IR, XRD and FE-SEM with EDX studies. The detoxified nature of the dye degraded metabolites was confirmed by the significant growth of green gram. The color fastness and color strength of the fabrics dyed using Fissidens species treated dye solution were compared with the tap water dyed fabrics which indicated the reuse potential of treated water in textile sector. The decolorization efficiency was further confirmed through in silico approach, where safranin well docked with the active sites of Photosystem II protein D1 of the Fissidens species. Thus, the present study proves that Fissidens species is a promising biosorbent for safranin decolorization and will lay a platform for the control and management of environmental pollution.

Altererythrobacter lutimaris sp. nov., a marine bacterium isolated from a tidal flat and reclassification of Altererythrobacter deserti, Altererythrobacter estronivorus and Altererythrobacter muriae as Tsuneonella deserti comb. nov., Croceicoccus estronivorus comb. nov. and Alteripontixanthobacter muriae comb. nov.

A yellow-coloured bacterium, designated strain JGD-16T, was isolated from a tidal flat in Janggu-do, Garorim Bay, Taean-gun, Chungcheongbuk-do, Republic of Korea. Cells were Gram-stain-negative, aerobic, non-flagellated and short ovoid to coccoid-shaped. Growth was observed at 10-37 °C (optimum, 30 °C), pH 6.0-9.0 (pH 8.0) and with 1-5% (w/v) NaCl (2%). Results of 16S rRNA gene sequence analysis indicated that strain JGD-16T was closely related to Altererythrobacter xiamenensis LY02T (97.1 %), Altererythrobacter aurantiacus O30T (96.3 %), Altererythrobacter ishigakiensis JPCCMB0017T (95.8 %), Altererythrobacter epoxidivorans JCS350T (95.7 %) and Altererythrobacter insulae BPTF-M16T (95.3%). Phylogenomic analysis using the maximum-likelihood algorithm showed that strain JGD-16T formed a clade with the genus Altererythrobacter. The genomic DNA G+C content was 57.8 mol%. The predominant respiratory quinone was ubiquinone-10. The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, a sphingoglycolipid, an unidentified glycolipid and an unidentified lipid. The major fatty acids were C18:1 ω7c (31.5 %) and C18:3 ω6c (19.6 %). On the basis of its phylogenomic, physiological and chemotaxonomical characteristics, strain JGD-16T represents a novel species within the genus Altererythrobacter, for which the name Altererythrobacter lutimaris JGD-16Tsp. nov. is proposed. The type strain is JGD-16T (=KCTC 72632T=KACC 21405T=JCM 33750T). We also propose the reclassification of Altererythrobacter deserti as Tsuneonella deserti comb. nov., Altererythrobacter estronivorus as Croceicoccus estronivorus comb. nov. and Altererythrobacter muriae as Alteripontixanthobacter muriae comb. nov.

Novosphingobium aureum sp. nov., a marine bacterium isolated from salt flat sediment.

A Gram-stain-negative, aerobic, pale yellow-coloured, rod-shaped marine bacterium designated strain YJ-S2-02T was isolated from salt flat sediment sampled in Yongyu-do, Republic of Korea. Strain YJ-S2-02T grew at pH 6.0-9.0 (optimum, pH 7.0), 10-40 °C (optimum, 30 °C) and with optimum 1 % (w/v) NaCl. The 16S rRNA gene sequence analysis indicated that strain YJ-S2-02T was closely related to Novosphingobium naphthalenivorans NBRC 102051T (97.8 %) followed by Novosphingobium mathurense SM117T (97.5 %), Novosphingobium indicum H25T (97.3 %), Novosphingobium pentaromativorans US6-1T (96.8 %), Novosphingobium fontis STM-14T (96.6 %), Novosphingobium endophyticum EGI60015T (96.5 %), Novosphingobium naphthae D39T (96.5 %) and Novosphingobium malaysiense MUSC 273T (95.9 %). The average nucleotide identity and estimated DNA-DNA hybridization values between YJ-S2-02T and related type strains were 77.0-77.9 % and 19.1-24.0 %. Strain YJ-S2-02T was characterized as having Q-10 as the predominant respiratory quinone and the principal fatty acids (>10 %) were summed feature 8 (C18 : 1 ω6c/ω7c, 20.7 %), C18 : 3 ω6c (16.3 %) and C17 : 1 ω6c (11.8 %). The polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, sphingolipids and two unidentified lipids. The DNA G+C content of strain YJ-S2-02T was 65.6 mol%. On the basis of the polyphasic taxonomic evidence presented in this study, YJ-S2-02T should be classified as representing a novel species within the genus Novosphingobium, for which name Novosphingobium aureum is proposed, with the type strain YJ-S2-02T (=KACC 21677T =KCTC 72891T=JCM 33996T).

Muricauda ochracea sp. nov., isolated from a tidal flat in the Republic of Korea.

A yellowish-brown-coloured bacterium, designated strain JGD-17T, was isolated from a tidal flat of Janggu-do, Garorim bay, Taean-gun, Chungcheongbuk-do, Republic of Korea. Cells were Gram-stain-negative, aerobic, non-flagellated and long-rod-shaped. Growth was observed at 20-45 °C (optimum, 25-30 °C), at pH 6.0-10.0 (9.0) and with 1-5 % (w/v) NaCl (1-3 %). Results of 16S rRNA gene sequence analysis indicated that strain JGD-17T was closely related to Muricauda nanhaiensis SM1704T (96.1 %), Muricauda olearia CL-SS4T (95.0 %), Muricauda beolgyonensis BB-My12T (94.9 %), Muricauda marina H19-56T (94.7 %) and Muricauda indica 3PC125-7T (94.5 %). The ranges of values for the average nucleotide identity and digital DNA-DNA hybridization analyses with related strains were 71.3-74.1 % and 16.9-18.2 %. The genomic DNA G+C content was 41.1 mol%. Phylogenetic analysis using the neighbour-joining method showed that strain JGD-17T formed a clade with Muricauda nanhaiensis SM1704T, Muricauda lutaonensis CC-HSB-11T, Muricauda lutea CSW06T and Muricauda pacifica SM027T. The major fatty acids were iso-C15 : 0 (26.9 %), iso-C15 : 1 G (19.5 %) and iso-C17 : 0 3-OH (12.7 %). The predominant respiratory quinone was menaquinone-6. The polar lipids were phosphatidylethanolamine, an unidentified aminolipid, an unidentified phospholipid and two unidentified lipids. On the basis of phylogenetic, phenotypic and chemotaxonomic characteristics, strain JGD-17T represents a novel species within the genus Muricauda, for which the name Muricauda ochracea sp. nov. is proposed. The type strain is JGD-17T (=KCTC 72732T=KACC 21486T=JCM 33817T).

Marinobacter halodurans sp. nov., a halophilic bacterium isolated from sediment of a salt flat.

A Gram-staining-negative, aerobic, cream-coloured, marine bacterium, with rod-shaped cells, designated strain YJ-S3-2T, was isolated from salt flat sediment of Yongyu-do, Republic of Korea. YJ-S3-2T grew at pH 5.0-9.0 (optimum pH 7.0), 4-45 °C (optimum 30 °C) and with 1-18 % (w/v) NaCl (optimum 6 %). The results of 16S rRNA gene sequence analysis indicated that YJ-S3-2T was closely related to Marinobacter segnicrescens SS011B1-4T (97.0 %) followed by, 'Marinobacter nanhaiticus' D15-8W (96.7 %), Marinobacter bryozoorum 50-11T (96.7 %), Marinobacter koreensis DSMZ 179240T T (96.5 %) and Marinobacter bohaiensis T17T (96.5 %). The average nucleotide identity (ANI) and the genome to genome distance calculator (GGDC) estimate values between YJ-S3-2T and related type strains were 73.7-79.8 and 19.9-22.5 %, and also 73.5 and 20.7 % with Marinobacter hydrocarbonoclasticus. YJ-S3-2T was characterized as having Q-9 as the predominant respiratory quinone and the principal fatty acids (>10 %) were C16 : 0 (22.3 %), summed feature 9 (C17 : 1iso ω9c/C16 : 0 10-methyl, 13.8 %) and 3 (C16 : 1ω7c/C16 : 1ω6c, 11.9 %). The polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, two unidentified aminolipids and two unidentified phospholipids. The DNA G+C content of YJ-S3-2T is 60.9 mol%. On the basis of the polyphasic taxonomic evidence presented in this study, YJ-S3-2T should be classified as representing a novel species within the genus Marinobacter, for which name Marinobacter halodurans sp. nov. is proposed, with the type strain YJ-S3-2T (=KACC 19883T=KCTC 62937T=JCM 33109T).

Multiple Bioassays and Targeted and Nontargeted Analyses to Characterize Potential Toxicological Effects Associated with Sediments of Masan Bay: Focusing on AhR-Mediated Potency.

An enhanced, multiple lines of evidence approach was applied to assess potential toxicological effects associated with polluted sediments. Two in vitro bioassays (H4IIE-luc and Vibrio fischeri) and three in vivo bioassays (microalgae: Isochrysis galbana and Phaeodactylum tricornutum; zebrafish embryo: Danio rerio) were applied. To identify causative chemicals in samples, targeted analyses (polycyclic aromatic hydrocarbons (PAHs), styrene oligomers (SOs), and alkylphenols) and nontargeted full-scan screening analyses (FSA; GC- and LC-QTOFMS) were performed. First, great AhR-mediated potencies were observed in midpolar and polar fractions of sediment extracts, but known and previously characterized AhR agonists, including PAHs and SOs could not fully explain the total potencies of samples. Enoxolone was identified as a novel AhR agonist in a highly potent sediment fraction by use of FSA. Enoxolone has a relative potency of 0.13 compared to benzo[a]pyrene (1.0) in the H4IIE-luc bioassay. Nonylphenols associated with membrane damage that influenced the viability of the microalgae were also observed. Finally, inhibitions of bioluminescence of V. fischeri and lethality of D. rerio embryos were strongly related to nonpolar compounds. Overall, the present work addressed assay- and end point-specific variations and sensitivities for potential toxicities of mixture samples, warranting a significant utility of the "multiple lines of evidence" approach in ecological risk assessment.

Serinicoccus sediminis sp. nov., isolated from tidal flat sediment.

A novel Gram-strain-positive, non-spore-forming bacterial strain, designated GP-T3-3T, was isolated from sediment sampled at a tidal flat in Gopado, Republic of Korea. Cells were aerobic, catalase-negative, oxidase-positive, non-motile cocci that occurred singly, in pairs or in clusters. Strain GP-T3-3T grew at 4-45 °C (optimum, 28-37 °C), at pH 4.0-12.0 (pH 8.0-9.0) and in the presence of 0-15 % (w/v) NaCl (3-5 %). Colonies of strain GP-T3-3T were deep-yellow, circular, smooth and pulvinate. The results of the phylogenetic analyses based on 16S rRNA gene sequences indicated that strain GP-T3-3T was closely related to Serinicoccus profundi MCCC 1A05965T (99.1 %), Serinicoccus chungangensis CAU 9536T (99.0 %) and Serinicoccus marinus JC1078T (98.0 %). The diagnostic diamino acid in the cell-wall peptidoglycan was meso-diaminopimelic acid. The predominant respiratory quinone was MK-8(H4) and the major fatty acids were anteiso-C17 : 0, iso-C16 : 0, iso-C15 : 0 and anteiso-C15 : 0. The polar lipid profile consisted of diphosphadidylglycerol, phosphadidylglycerol, phosphatidylcholine, phosphatidylinositol and two unidentified phospholipids. The DNA G+C content was 72.9 mol%. DNA-DNA relatedness values between strain GP-T3-3T and type strains of the genus Serinicoccus ranged from 28.9 to 50.5 %. On the basis of the phenotypic differences and DNA-DNA relatedness data, the isolate represents a new species of the genus Serinicoccus, for which the name Serinicoccussediminis sp. nov. is proposed. The type strain is GP-T3-3T (=KCTC 49173T=JCM 32825T=KCCM 43309T=KACC 19850T).

Gemmobacter lutimaris sp. nov., a marine bacterium isolated from a tidal flat.

A novel cream-pigmented marine bacterium, designated strain YJ-T1-11T, was isolated from a tidal flat at Yeongjong-do, Republic of Korea. Cells were rod-shaped, non-motile, aerobic, Gram-reaction-negative, oxidase-positive and catalase-positive. Phylogenetic analysis of 16S rRNA gene sequences indicated that strain YJ-T1-11T clustered with Gemmobacter fontiphilus JS43T (98.3 %) within the genus Gemmobacter and its closest neighbours were G.emmobacter aquatilis DSM 3857T (98.5 %), Gemmobacter aquaticus A1-9T (98.4 %), Gemmobacterlanyuensis Orc-4T (98.4 %), Gemmobacterfontiphilus JS43T (98.3 %), Gemmobactercaeni DCA-1T (98.2 %), Gemmobacternanjingensis Y12T (97.5 %) and Gemmobactertilapiae Ruye-53T (97.2 %). Average nucleotide identity values between the genome sequences of strain YJ-T1-11T and the related type strains ranged from 77.08 to 90.48 %. The predominant fatty acid of strain YJ-T1-11T was summed feature 8 (comprising C18 : 1ω7c and/or C18 : 1ω6c). The major isoprenoid quinone was Q-10 and the DNA G+C content was 65.6 mol%. The polar lipid profile consisted of phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, diphosphatidylglycerol and three unidentified lipids. The DNA-DNA relatedness values between strain YJ-T1-11T and the type strains of the 12 phylogenetically related species of the genus Gemmobacter were 23.6-53.7 %. On the basis of the genotypic, chemotaxonomic and phenotypic data, strain YJ-T1-11T is considered to represent a novel species of the genus Gemmobacter, for which the name Gemmobacter lutimaris sp. nov. is proposed. The type strain is YJ-T1-11T (=KCTC 62715T=JCM 32828T).

Newly Identified AhR-Active Compounds in the Sediments of an Industrial Area Using Effect-Directed Analysis.

Effect-directed analysis was used to identify previously unidentified aryl hydrocarbon receptor (AhR) agonists in sediments collected from a highly industrialized area of Ulsan Bay, Korea. The specific objectives were to (i) investigate potent fractions of sediment extracts using the H4IIE-luc bioassay, (ii) determine the concentrations of known AhR agonists (polycyclic aromatic hydrocarbons (PAHs) and styrene oligomers (SOs)), (iii) identify previously unreported AhR agonists in fractions by use of GC-QTOFMS, and (iv) evaluate contributions of individual compounds to overall AhR-mediated potencies, found primarily in fractions containing aromatics with log Kow 5-8. Greater concentrations of PAHs and SOs were also found in those fractions. On the basis of GC-QTOFMS and GC-MSD analyses, 16 candidates for AhR agonists were identified in extracts of sediments. Of these, seven compounds, including 1-methylchrysene, benzo[j]fluoranthene, 3-methylchrysene, 5-methylbenz[a]anthracene, 11H-benzo[b]fluorene, benzo[b]naphtho[2,3-d]furan, and benzo[b]naphtho[2,1-d]thiophene, exhibited significant AhR activity. Relative potency values of newly identified AhR agonists were found to be greater than or comparable to that of benzo[a]pyrene (BaP). The potency balance analysis showed that newly identified AhR agonists explained 0.07-16% of bioassay-derived BaP-EQs. These chemicals were widely distributed in industrial sediments; thus, it is of immediate importance to conduct studies on sources and potential effects of those chemicals.

Evaluation of residual toxicity of hypochlorite-treated water using bioluminescent microbes and microalgae: Implications for ballast water management.

Total residual oxidants (TRO) in treated ballast water can produce various disinfection by-products (DBPs) depending on local conditions, such as salinity and organic matter content in water. Because TRO and DBPs are known to be harmful to aquatic organisms and humans, ecotoxicity tests have been proposed for screening the residual toxicity before discharging treated ballast water. In the present study, we aimed to address the decay rates and toxicity changes of TRO under various conditions in salinity, initial TRO concentrations, and residence time of TRO. In addition, the toxicological sensitivities of bioluminescent bacteria Vibrio fischeri and a commonly-used microalgae Skeletonema costatum relative to the residual toxicity of TRO and six selected DBPs were determined. Decay rate of TRO concentration increased as a function of salinity and was affected by the initial concentrations of TRO. Unexpectedly, significant bioluminescence inhibition was observed for hypochlorite-treated water at < 0.1 mg L-1 TRO (expressed as Cl2), which is a lower concentration than the maximum allowable discharge concentration (MADC) to marine waters established by the International Maritime Organization (IMO). The ecotoxicological thresholds of no observed effective concentration and median effect concentration for all tested DBPs were about 3-10 times lower for V. fischeri than for S. costatum. The results indicate that bioluminescent microbes possess an ecologically-relevant sensitivity to both TRO and DBPs in ballast water. In general, bioassay using V. fischeri was potentially more effective than microalgae for screening the total toxicity of TRO and DBPs in treated ballast water, especially given that ballast water usually contains a highly variable and complex mixture of toxicants.

Multiple evaluation of the potential toxic effects of sediments and biota collected from an oil-polluted area around Abu Ali Island, Saudi Arabia, Arabian Gulf.

After the Gulf War Oil Spill, there have been many investigations about distributions of oil-derived pollutants nearby areas, but lacking in ecotoxicological assessment. We evaluated the potential toxicity of asphalt mats, sediments, and biota (polychaetes, chitons, snapping shrimps, and crabs) by combining two bioassays (H4IIE-luc and Vibrio fischeri) and in situ microbial community (eDNA). Samples were collected from Abu Ali Island, and organic extracts were bioassayed and further fractionated according to the chemical polarity using silica gel column. Great aryl hydrocarbon receptor (AhR)-mediated potencies and inhibition of bioluminescence were mainly found in aromatics (F2) and saturates (F1) fractions of asphalt mat and sediments, respectively, while great toxicological responses in biota samples were found in resins and polar (F3) fraction. We also confirmed that potential toxicities of biota were species-specific; great AhR-mediated potencies were found in polychaetes and great bioluminescence inhibitions were found in crabs. In microbial communities, most genera (up to 90%) were associated with polycyclic aromatic hydrocarbons (PAHs)-degrading bacteria, supporting that PAHs are the primary stressors of the benthic community around Abu Ali Island. The present study provides useful information on the contamination status, risk assessment of environmental matrices and benthic organisms in Abu Ali Island.

Blastococcus litoris sp. nov., isolated from sea-tidal flat sediment.

A novel Gram-strain-positive, non-spore-forming bacterial strain, designated GP-S2-8T, was isolated from a sea-tidal flat sediment sample from Gopado, Republic of Korea. Cells were aerobic, catalase-negative, oxidase-positive, non-motile and cocci, occurring singly, in pairs or in tetrads, and often tending to form aggregates. The strain grew at 4-45 °C (optimum, 28-37 °C), at pH 4.0-11.0 (pH 7.0-9.0) and in the presence of 0-11 % (w/v) NaCl (0-3 %). Phylogenetic analyses based on 16S rRNA gene sequences represented that the isolate belongs to the genus Blastococcus. The diagnostic diamino acid in the cell-wall peptidoglycan was meso-diaminopimelic acid. Whole-cell sugar analysis of strain GP-S2-8T revealed rhamnose, glucose and mannose as characteristic sugars. The predominant respiratory quinone was MK-9(H4) and the major fatty acids were iso-C16 : 0, iso-C16 : 1 H, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), iso-C15 : 0 and iso-C14 : 0. The polar lipid profile included diphosphadidylglycerol, phosphatidylethanolamine, phosphatidylcholine, phosphatidylinositol, one unidentified glycophospholipid, two unidentified phospholipids and five unidentified lipids. The DNA G+C content was 74.2 mol%. DNA-DNA relatedness values between strain GP-S2-8T and type strains of the genus Blastococcus ranged from 14.6 to 48.6 %. On the basis of the phenotypic differences and DNA-DNA relatedness data, the isolate represents a new species of the genus Blastococcus, for which the name Blastococcuslitoris sp. nov. is proposed. The type strain is GP-S2-8T (=KCCM 43275T=JCM 32354T=DSM 106127T=KCTC 49078T).

Maribacter litoralis sp. nov. a marine bacterium isolated from seashore.

A novel Gram-stain-negative, moderately halophilic and aerobic bacterium, designated strain SDRB-Phe2T, was isolated from coastal sediment of the yellow sea in Sindu-ri, Republic of Korea. Cells were oxidase-positive, catalase-positive, rod-shaped and surrounded by a capsule with gliding motility. Colonies were yellow-coloured, circular, pulvinate with entire margins. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain SDRB-Phe2T formed a distinct lineage within the genus Maribacter of the family Flavobacteriaceae. Stain SDRB-Phe2T exhibited 16S rRNA gene sequence similarity values of 97.1-98.9 % to the type strains of Maribacterstanieri, Maribacterspongiicola, Maribacter forsetii, Maribacter dokdonensis, Maribacter aquivivus, Maribactercaenipelagi, Maribacterlitorisediminis, Maribactersedimenticola, Maribacterulvicola, Maribacter confluentis and Maribacter orientalis, and of 94.8-96.7 % to the type strains of the other species of the genus Maribacter. Strain SDRB-Phe2T contained MK-6 as the predominant respiratory quinone and iso-C15 : 1 G, iso-C15 : 0 and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) as the major fatty acids. The polar lipids of strain SDRB-Phe2T were phosphatidylethanolamine, one unidentified amino lipid and two unidentified lipids. The DNA G+C content was 36.2 mol%. DNA-DNA relatedness values of strain SDRB-Phe2T to the type strains of the 11 phylogenetically related species of the genus Maribacter were 21.9-38.6 %. On the basis of the phenotypic features, phylogenetic and DNA-DNA hybridization analyses presented here, strain SDRB-Phe2T (=JCM 32373T=KCTC 62273T=DSM 106042T) represents a novel species of the genus Maribacter, for which the name Maribacterlitoralis sp. nov. is proposed.