Unique evolutionary trajectories in repeated adaptation to hydrogen sulphide‐toxic habitats of a neotropical fish (Poecilia mexicana)

Replicated ecological gradients are prime systems to study processes of molecular evolution underlying ecological divergence. Here, we investigated the repeated adaptation of the neotropical fish Poecilia mexicana to habitats containing toxic hydrogen sulphide (H₂S) and compared two population pairs of sulphide‐adapted and ancestral fish by sequencing population pools of >200 individuals (Pool‐Seq). We inferred the evolutionary processes shaping divergence and tested the hypothesis of increase of parallelism from SNPs to molecular pathways. Coalescence analyses showed that the divergence occurred in the face of substantial bidirectional gene flow. Population divergence involved many short, widely dispersed regions across the genome. Analyses of allele frequency spectra suggest that differentiation at most loci was driven by divergent selection, followed by a selection‐mediated reduction of gene flow. Reconstructing allelic state changes suggested that selection acted mainly upon de novo mutations in the sulphide‐adapted populations. Using a corrected Jaccard index to quantify parallel evolution, we found a negligible proportion of statistically significant parallel evolution of J_corr = 0.0032 at the level of SNPs, divergent genome regions (J_corr = 0.0061) and genes therein (J_corr = 0.0091). At the level of metabolic pathways, the overlap was J_corr = 0.2545, indicating increasing parallelism with increasing level of biological integration. The majority of pathways contained positively selected genes in both sulphide populations. Hence, adaptation to sulphidic habitats necessitated adjustments throughout the genome. The largely unique evolutionary trajectories may be explained by a high proportion of de novo mutations driving the divergence. Our findings favour Gould's view that evolution is often the unrepeatable result of stochastic events with highly contingent effects.     

Desulfonauticus autotrophicus sp. nov., a novel thermophilic sulfate-reducing bacterium isolated from oil-production water and emended description of the genus Desulfonauticus

A novel moderately thermophilic and halophilic sulfate-reducing bacterium, strain TeSt^T, was isolated from production water of an oil field in Northern Germany near Hamburg. The cells were Gram-negative, straight to slightly curved rods and motile by a single polar flagellum. Only hydrogen and formate served as electron donors, whereas a wide variety of organic substrates and CO₂ could be used as carbon sources. Sulfate, sulfite, thiosulfate and sulfur were used as electron acceptors, but not nitrate or ferric iron. The novel isolate was negative for oxidase, catalase and desulfoviridin enzyme activity. Cytochromes were present and predominantly of the c-type. Whole-cells fatty acid patterns were dominated by the branched-chain fatty acids anteiso-C_15:0, iso-C_15:0, iso-C_17:0 and anteiso-C_17:0. As major respiratory lipoquinones partially saturated derivates of menaquinone 6 [MK-6(H₂) and probably MK-6(H₄)] were identified. The G + C content of the genomic DNA was 41.3 mol% (HPLC method). An analysis of the 16S rRNA gene sequence indicated that strain TeSt^T belongs to the family Desulfohalobiaceae within the class Deltaproteobacteria. The most closely related species with a sequence similarity of 95.0% was Desulfonauticus submarinus suggesting an affiliation of TeSt^T to the genus Desulfonauticus. The novel isolate could be clearly distinguished from Desulfonauticus submarinus by its ability to grow chemolithoautotrophically and hence should be assigned to a novel species for which the name Desulfonauticus autotrophicus sp. nov. is proposed. The type strain is TeSt^T (=DSM 4206^T = JCM 13028^T). Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

<Emphasis Type="Italic">Paracoccus oceanense</Emphasis> sp. nov., Isolated from the West Pacific

A Gram-negative, short ovoid- to coccus-shaped, aerobic, motile, non-spore-forming bacterium (designated strain JLT1679^T) was isolated from West Pacific. Cells have subpolar flagella, dividing by binary fission. Phylogenetic analyses based on 16S rRNA gene sequences showed that the strain belongs to branch of the evolutionary radiation occupied by the genus Paracoccus, family Rhodobacteraceae, order Rhodobacterales, class Alphaproteobacteria. The closest neighbours were Paracoccus stylophorae KTW-16^T (97.1% similarity), Paracoccus caeni strain MJ17^T (96.5% similarity), Paracoccus homiensis DD-R11^T (96.0% similarity) and Paracoccus alcaliphilus JCM 7364^T (95.8% similarity). The predominant cellular fatty acids of strain JLT1679^T were summed feature 8 (18:1ω6c) (38.8%), C_18:0 (27.7%), C_16:0 (22.5%), and significant amounts of C_18:1 ω9c (5.1%), C_14:0 (3.8%) and C_18:1 ω7c 11-methyl (2.1%), were present. The predominant respiratory ubiquinone of strain JLT1679^T was Q-10 and the DNA G + C content of strain JLT1679^T was 59.5 mol%. The polar lipid profile consisted of a mixture of phosphatidylglycerol, diphosphatidylglycerol, phosphatidylcholine and sphingoglycolipid. The isolate was distinguishable from members of the genus Paracoccus on the basis of phenotypic and biochemical characteristics. It is evident from the genotypic, chemotaxonomic and phenotypic data that strain JLT1679^T represents a novel species of the genus Paracoccus, for which the name Paracoccus oceanense sp. nov. is proposed. The type strain is JLT1679^T (= JCM 17768^T = CGMCC 1.10831^T).     

Cohnella plantaginis sp. nov., a novel nitrogen-fixing species isolated from plantain rhizosphere soil

A novel bacterium capable of fixing nitrogen was isolated from plantain rhizosphere soil in China. The isolate, designated YN-83^T, is Gram-positive, aerobic, motile and rod-shaped (0.4–0.6 μm × 1.9–2.6 μm). Phylogenetic analysis based on the 16S rRNA gene sequence revealed that strain YN-83^T was a member of the genus Cohnella. High similarity of 16S rRNA gene sequence was found between YN-83^T and Cohnella ginsengisoli DSM18997^T (97.99%), whereas the similarity was below 96.0% between YN-83^T and the other Cohnella species. DNA–DNA relatedness between strain YN-83^T and C. ginsengisoli DSM18997^T was 27.4 ± 6.2%. The DNA G+C content of strain YN-83^T was 59.3 mol%. The predominant isoprenoid quinone was MK-7 and the major fatty acids were anteiso-C_15:0 (44.3%), iso-C_15:0 (11.3%), iso-C_16:0 (18.6%) and C_16:0 (7.7%). The polar lipids of strain YN-83^T consist of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, lyso- phosphatidylglycerol, phosphatidylinositol and phosphatidylinositol mannosides. On the basis of phenotypic and chemotaxonomic properties, 16S rRNA gene sequence, G+C content and DNA–DNA hybridization, strain YN-83^T represents a novel species of the genus Cohnella, for which the name Cohnella plantaginis sp. nov. (type strain YN-83^T = DSM 25424^T = CGMCC 1.12047^T) is proposed.     

Improving green emission of Tb3+ ions in BaO‐B2O3‐P2O5 glasses by means of Al3+ ions

BaO‐B₂O₃‐P₂O₅ glasses doped with a fixed concentration of Tb³⁺ ions and varying concentrations of Al₂O₃ were synthesized, and the influence of the Al³⁺ ion concentration on the luminescence efficiency of the green emission of Tb³⁺ ions was investigated. The optical absorption, excitation, luminescence spectra and fluorescence decay curves of these glasses were recorded at ambient temperature. The emission spectra of terbium ions when excited at 393 nm exhibited two main groups of bands, corresponding to ⁵D₃ → ⁷F_j (blue region) and ⁵D₄ → 7F_j (green region). From these spectra, the radiative parameters, viz., spontaneous emission probability A, total emission probability A_T, radiative lifetime τ and fluorescent branching ratio β, of different transitions originating from the ⁵D₄ level of Tb³⁺ ions were evaluated based on the Judd‐Ofelt theory. A clear increase in the quantum efficiency and luminescence of the green emission of Tb³⁺ ions corresponding to ⁵D₄ → ⁷F₅ transition is observed with increases in the concentration of Al₂O₃ up to 3.0 mol%. The improvement in emission is attributed to the de‐clustering of terbium ions by Al³⁺ ions and also to the possible admixing of wave functions of opposite parities. Copyright © 2016 John Wiley & Sons, Ltd.     

Rufibacter tibetensis gen. nov., sp. nov., a novel member of the family Cytophagaceae isolated from soil

A red-pigmented, Gram-negative, strictly aerobic, rod-shaped bacterium which was motile by gliding, designated strain 1351^T, was isolated from the soil of Lengduo, Tibet in China and subjected to a polyphasic taxonomic analysis. The isolate grows optimally at 30°C and pH 7. It grows with NaCl tolerated up to 1.5% (optimum, 0.5%). Phylogenetic analysis based on the 16S rRNA gene sequence shows that strain 1351^T is closely related to members of the family ‘Cytophagaceae’ closest sequence similarity was observed with similarity with Adhaeribacter terreus (91.8%). The major whole-cell fatty acids are summed feature 4 (containing anteiso-C_17:1 B and/or iso-C_17:1 I, 29.2%), summed feature 3 (containing C_16:1ω6c and/or C_16:1ω7c, 13.0%) and iso-C_15:0 (12.0%). The predominant menaquinone of strain 1351^T is menaquinone-7 (MK-7) and the G+C content of the DNA is 46.8 mol%. According to the phylogenetic evidence and phenotypic data, strain 1351^T is considered to represent a new genus and species of the family ‘Cytophagaceae’ for which the name Rufibacter tibetensis gen nov., sp. nov. is proposed. The type species is R. tibetensis and the type strain is 1351^T (=CCTCC AB 208084^T = NRRL B-51285^T).     

Microvirga splendida sp. nov., bacteria isolated from soil

Two bacterial strains, BT325^T and BT690, were isolated from soil samples collected in Korea. Both strains were Gram stain-negative, short rod-shaped, and formed light-pink colored colonies. The 16S rRNA sequence similarity of strains BT325^T and BT690 shared a sequence similarity of 99.7%. Both strains shared the highest 16S rRNA gene similarity of 98.6% with Microvirga arabica SV2184P^T, followed by Microvirga ossetica V5/3 M T (98.5% and 98.2%, respectively), Microvirga soli R491^T (98.3% and 98.2%, respectively), Microvirga aerilata (98.2% and 98.08%, respectively), Microvirga makkahensis (98.08% and 97.8%, respectively). Phylogenetic analyses based on 16S rRNA gene sequences revealed that strain BT325^T and BT690 were positioned in a distinct lineage within the family Methylobacteriaceae (order Rhizobiales, class Alphaproteobacteria). The genome size of strain BT325^T was 5,200,315 bp and the genomic DNA G?+?C content was 64.3 mol%. The sole respiratory quinone of strain BT325^T was Q-10 and the predominant cellular fatty acids were summed feature 3 (C_16:1 ω7c/C_16:1 ω6c) and summed feature 8 (C_18:1 ω7c/C_18:1 ω6c). The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, and phosphatidylcholine. Polyphasic taxonomic analysis of biochemical, chemotaxonomic, and phylogenetic analyses suggested that strains BT325^T represents a novel bacterial species within the genus Microvirga, for which the name Microvirga splendida is proposed. The type strain of Microvirga splendida is BT325^T (=?KCTC 72406 ^T?=?NBRC 114847 ^T).

     

Shinella oryzae sp. nov., a novel zearalenone-resistant bacterium isolated from rice paddy soil

A novel bacterium, designated Z-25 ^T, was isolated from a rice paddy rhizosphere soil sample from Wuchang County, China. The Z-25 ^T strain is gram-negative, rod-shaped, non-spore-forming, aerobic, motile by unipolar flagella and straw white in color. A phylogenetic analysis based on the 16S rRNA gene sequence revealed that strain Z-25 belongs to the genus Shinella, and the closest members are Shinella zoogloeoides ATCC 19623 ^T with 98.58% similarity, S. kummerowiae CCBAU 25,048 T (98.03%) and S. granuli Ch06 ^T (97.37%). The average nucleotide identity and in silico DNA-DNA hybridization values between strain Z-25 ^T and the closest members were less than 85.29% and 28.70%, respectively. The predominant fatty acids were the sums of features comprising C_18:1 ω7c and/or C_18:1 ω6c (34.62%), C_18:1 ω7c -11-methyl (20.48%), and C_19:0 cyclo ω8c (18.19%). The only respiratory quinone was ubiquinone-10, and the major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. Additionally, a genome analysis showed that Z-25 ^T presented potential functional genes related to the degradation of zearalenone (ZEN). An HPLC analysis indicated that Z-25 ^T could remove 74.13% of 10 mg/L ZEN after 144 h at 30 °C. Therefore, based on phenotypic, chemotaxonomic, phylogenetic and genotypic analyses, strain Z-25 ^T represents a novel species in the genus Shinella, for which the name Shinella oryzae sp. nov. is proposed. The type strain is Z-25 ^T (=?GDMCC 1.2424 ^T?=?KCTC 82660 ^T).

     

Identification of (η6-arene)ruthenium(II) protein binding sites in E. coli cells by combined multidimensional liquid chromatography and ESI tandem mass spectrometry: specific binding of [(η6- p -cymene)RuCl2(DMSO)] to stress-regulated proteins and to helicases

An automated multidimensional protein identification technology, which combines biphasic liquid chromatography with electrospray ionisation tandem mass spectrometry (MS/MS), was employed to analyse tryptic peptides from Escherichia coli cells treated with the antiproliferation agent [(η⁶-p-cymene)RuCl₂(DMSO)], where DMSO is dimethyl sulfoxide. MS/MS spectra were recorded for molecular ions generated by neutral loss of p-cymene from intensive peptide ions coordinated by the (η⁶-p-cymene)Ru^II fragment. Matching of the MS/MS spectra of the ruthenated peptides to spectra of proteins in the E. coli database enabled the identification of five protein targets for [(η⁶-p-cymene)RuCl₂(DMSO)]. One of these is the constitutive cold-shock protein cspC, which regulates the expression of genes encoding stress-response proteins, and three of the other targets, ppiD, osmY and sucC, are proteins of the latter type. The DNA damage-inducible helicase dinG was likewise established as a protein target. Aspartate carboxylate functions were identified as the probable Ru binding sites in cspC, ppiD and dinG, and threonine and lysine side chains in osmY and sucC, respectively. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Description of Aureibaculum luteum sp. nov. and Aureibaculum flavum sp. nov. isolated from Antarctic intertidal sediments

Two Gram-stain-negative, aerobic, non-motile, and rod-shaped bacterial strains, designated SM1352^T and A20^T, were isolated from intertidal sediments collected from King George Island, Antarctic. They shared 99.8% 16S rRNA gene sequence similarity with each other and had the highest sequence similarity of 98.1% to type strain of Aureibaculum marinum but?<?93.4% sequence similarity to those of other known bacterial species. The genomes of strains SM1352^T and A20^T consisted of 5,108,092 bp and 4,772,071 bp, respectively, with the G?+?C contents both being 32.0%. They respectively encoded 4360 (including 37 tRNAs and 6 rRNAs) and 4032 (including 36 tRNAs and 5 rRNAs) genes. In the phylogenetic trees based on 16S rRNA gene and single-copy orthologous clusters (OCs), both strains clustered with Aureibaculum marinum and together formed a separate branch within the family Flavobacteriaceae. The ANI and DDH values between the two strains and Aureibaculum marinum BH-SD17^T were all below the thresholds for species delineation. The major cellular fatty acids (>?10%) of the two strains included iso-C_15:0, iso-C_15:1 G, iso-C_17:0 3-OH. Their polar lipids predominantly included phosphatidylethanolamine, one unidentified aminophospholipid, one unidentified aminolipid, and two unidentified lipids. Genomic comparison revealed that both strains possessed much more glycoside hydrolases and sulfatase-rich polysaccharide utilization loci (PULs) than Aureibaculum marinum BH-SD17^T. Based on the above polyphasic evidences, strains SM1352^T and A20^T represent two novel species within the genus Aureibaculum, for which the names Aureibaculum luteum sp. nov. and Aureibaculum flavum sp. nov. are proposed. The type strains are SM1352^T (=?CCTCC AB 2014243 ^T?=?JCM 30335 ^T) and A20^T (=?CCTCC AB 2020370 ^T?=?KCTC 82503 ^T), respectively.

     

Streptomyces phytohabitans sp. nov., a novel endophytic actinomycete isolated from medicinal plant Curcuma phaeocaulis

A novel actinomycete, designated strain KLBMP 4601^T, was isolated from the root of the medicinal plant Curcuma phaeocaulis collected from Sichuan Province, south-west China. The strain produced extensively branched substrate and aerial hyphae that carried straight to flexuous spore chains. Chemotaxonomic properties of this strain were consistent with those of members of the genus Streptomyces. The cell wall of strain KLBMP 4601^T contained ll-diaminopimelic acid as the characteristic diamino acid. The major menaquinone was MK-9(H₄), with minor amounts of MK-9(H₆), MK-9(H₈) and MK-10(H₂). The major fatty acids were C_16:0, iso-C_16:0, C_18:1ω9c and C_16:1, iso G. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain KLBMP 4601^T belongs to the genus Streptomyces and is most closely related to Streptomyces armeniacus JCM 3070^T (97.9 %), Streptomyces pharmamarensis PM267^T (97.6 %) and Streptomyces artemisiae YIM 63135^T (97.5 %). The 16S rRNA gene sequence similarity between strain KLBMP 4601^T and other members of this genus were lower than 97.5 %. DNA–DNA hybridization studies of strain KLBMP 4601^T with the three closest species showed relatedness values of 36.3 ± 4.2 %, 27.3 ± 0.6 %, and 30.9 ± 2.5 %, respectively. On the basis of chemotaxonomic, phenotypic and genotypic characteristics, it is evident that strain KLBMP 4601^T represents a novel species of the genus Streptomyces, for which the name Streptomyces phytohabitans sp. nov. is proposed. The type strain is KLBMP 4601^T (=KCTC 19892^T = NBRC 108772^T).     

Enhanced Rate Capability of Ion‐Accessible Ti3C2Tx‐NbN Hybrid Electrodes

Although 2D Ti₃C₂T_x is a good candidate for supercapacitors, the restacking of nanosheets hinders the ion transport significantly at high scan rates, especially under practical mass loading (>10 mg cm^?2) and thickness (tens of microns). Here, Ti₃C₂T_x‐NbN hybrid film is designed by self‐assembling Ti₃C₂T_x with 2D arrays of NbN nanocrystals. Working as an interlayer spacer of Ti₃C₂T_x, NbN facilitates the ion penetration through its 2D porous structure; even at extremely high scan rates. The hybrid film shows a thickness‐independent rate performance (almost the same rate capabilities from 2 to 20 000 mV s^?1) for 3 and 50 µm thick electrodes. Even a 109 µm thick Ti₃C₂T_x‐NbN electrode shows a better rate performance than 25 µm thick pure Ti₃C₂T_x electrodes. This method may pave a way to controlling ion transport in electrodes composed of 2D conductive materials, which have potential applications in high‐rate energy storage and beyond.     

The yeast metabolome addressed by electrospray ionization mass spectrometry: Initiation of a mass spectral library and its applications for metabolic footprinting by direct infusion mass spectrometry

Mass spectrometry (MS) has been a major driver for metabolomics, and gas chromatography (GC)-MS has been one of the primary techniques used for microbial metabolomics. The use of liquid chromatography (LC)-MS has however been limited, but electrospray ionization (ESI) is very well suited for ionization of microbial metabolites without any previous derivatization needed. To address the capabilities of ESI-MS in detecting the metabolome of Saccharomyces cerevisiae, the in silico metabolome of this organism was used as a template to present a theoretical metabolome. This showed that in combination with the specificity of MS up to 84% of the metabolites can be identified in a high mass accuracy ESI-spectrum. A total of 66 metabolites were systematically analyzed by positive and negative ESI-MS/MS with the aim of initiating a spectral library for ESI of microbial metabolites. This systematic analysis gave insight into the ionization and fragmentation characteristics of the different metabolites. With this insight, a small study of metabolic footprinting with ESI-MS demonstrated that biological information can be extracted from footprinting spectra. Statistical analysis of the footprinting data revealed discriminating ions, which could be assigned using the in silico metabolome. By this approach metabolic footprinting can advance from a classification method that is used to derive biological information based on guilt-by-association, to a tool for extraction of metabolic differences, which can guide new targeted biological experiments. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Cohnella boryungensis sp. nov., isolated from soil

A Gram-staining positive, endospore-forming, motile and rod-shaped bacterial strain, BR-29^T, was isolated from soil from west coast of the Korean peninsula, and its taxonomic position was investigated by a polyphasic study. Strain BR-29^T grew optimally at around pH 7.5, at 30°C and in the presence of 0.5% (w/v) NaCl. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain BR-29^T fell into a clade comprising the type strains of Cohnella species, with which it exhibited 16S rRNA gene sequence similarity values of 92.8–96.4%. Strain BR-29^T contained a cell wall peptidoglycan based on meso-diaminopimelic acid and MK-7 as the predominant menaquinone. The major fatty acids were anteiso-C_15:0, C_16:0 and iso-C_16:0. The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, lysylphosphatidylglycerol and two unidentified phospholipids; a minor amount of phosphatidylglycerol was present. The DNA G+C content was 54.9 mol%. Strain BR-29^T could be differentiated from phylogenetically related Cohnella species by differences in phenotypic characteristics. On the basis of phenotypic, chemotaxonomic and phylogenetic data, strain BR-29^T represents a novel species of the genus Cohnella, for which the name Cohnella boryungensis sp. nov., is proposed. The type strain is BR-29^T (= KCTC 13735^T = CCUG 59598^T).     

Analysis of lipids from crude lung tissue extracts by desorption electrospray ionization mass spectrometry and pattern recognition

A method is described using desorption electrospray ionization (DESI) mass spectrometry (MS) to obtain phospholipid mass spectral profiles from crude lung tissue extracts. The measured DESI mass spectral lipid fingerprints were then analyzed by unsupervised learning principal components analysis (PCA). This combined approach was used to differentiate the effect(s) of two vaccination routes on lipid composition in mouse lungs. Specifically, the two vaccination routes compared were intranasal (i.n.) and intradermal (i.d.) inoculation of the Francisella tularensis live vaccine strain (Ft–LVS). Lung samples of control and LVS-inoculated mice were quickly extracted with a methanol/chloroform solution, and the crude extract was directly analyzed by DESI–MS, with a total turnaround time of less than 10 min/sample. All of the measured DESI mass spectra (in both positive and negative ion mode) were compared via PCA, resulting in clear differentiation of mass spectral profiles of i.n.-inoculated mouse lung tissues from those of i.d.-inoculated and control mouse lung tissues. Lipid biomarkers responsible for sample differentiation were identified via tandem MS (MS/MS) measurements or by comparison with mass spectra of lipid standards. The DESI–MS approach described here provided a practical and rapid means to analyze tissue samples without extensive extractions and solvent changes.     

Pseudomonas oleovorans subsp. lubricantis subsp. nov., and Reclassification of Pseudomonas pseudoalcaligenes ATCC 17440T as Later Synonym of Pseudomonas oleovorans ATCC 8062T

Isolate RS1^T isolated from used metalworking fluid was found to be a Gram-negative, motile, and non-spore forming rod. Based on phylogenetic analyses with 16S rRNA, isolate RS1^T was placed into the mendocina sublineage of Pseudomonas. The major whole cell fatty acids were C_18:1ω7c (32.6%), C_16:0 (25.5%), and C_15:0 ISO 2OH/C_16:1ω7c (14.4%). The sequence similarities of isolate RS1^T based on gyrB and rpoD genes were 98.9 and 98.0% with Pseudomonas pseudoalcaligenes, and 98.5 and 98.1% with Pseudomonas oleovorans, respectively. The ribotyping pattern showed a 0.60 similarity with P. oleovorans ATCC 8062^T and 0.63 with P. pseudoalcaligenes ATCC17440^T. The DNA G + C content of isolate RS1^T was 62.2 mol.%. The DNA–DNA relatedness was 73.0% with P. oleovorans ATCC 8062^T and 79.1% with P. pseudoalcaligenes ATCC 17440^T. On the basis of morphological, biochemical, and molecular studies, isolate RS1^T is considered to represent a new subspecies of P. oleovorans. Furthermore, based on the DNA–DNA relatedness (>70%), chemotaxonomic, and molecular profile, P. pseudoalcaligenes ATCC 17440^T and P. oleovorans ATCC 8062^T should be united under the same name; according to the rules of priority, P. oleovorans, the first described species, is the earlier synonym and P. pseudoalcaligenes is the later synonym. As a consequence, the division of the species P. oleovorans into two novel subspecies is proposed: P. oleovorans subsp. oleovorans subsp. nov. (type strain ATCC 8062^T = DSM 1045^T = NCIB 6576^T), P. oleovorans subsp. lubricantis subsp. nov. (type strain RS1^T = ATCC BAA-1494^T = DSM 21016^T).     

Winogradskyella multivorans sp. nov., a polysaccharide-degrading bacterium isolated from seawater of an oyster farm

A novel bacterial strain, designated T-Y1^T, capable of degrading a variety of polysaccharides was isolated from seawater of an oyster farm in the South Sea, Korea. It was found to be aerobic, Gram-negative, non-flagellated, non-gliding and rod-shaped. Strain T-Y1^T grew optimally at 25 °C, at pH 7.0–7.5 and in the presence of 2 % (w/v) NaCl. A neighbour-joining phylogenetic tree based on 16S rRNA gene sequences showed that strain T-Y1^T belonged to the genus Winogradskyella. Strain T-Y1^T exhibited 16S rRNA gene sequence similarity values of 95.0–96.8 % to the type strains of recognized Winogradskyella species and less than 94.5 % to other validly named species. The chemotaxonomic data concurred with the phylogenetic inference. Strain T-Y1^T contained MK-6 as the predominant menaquinone and anteiso-C_15:0, iso-C_15:0, iso-C_15:1 G and iso-C_16:0 3-OH as the major fatty acids. The major polar lipids of strain T-Y1^T were phosphatidylethanolamine and two unidentified lipids. The DNA G+C content was 36.2 mol%. Differential phenotypic properties, together with its phylogenetic distinctiveness, enabled strain T-Y1^T to be differentiated from the recognized Winogradskyella species. On the basis of the data presented here, strain T-Y1^T is considered to represent a novel species of the genus Winogradskyella, for which the name Winogradskyella multivorans sp. nov. is proposed. The type strain is T-Y1^T (=KCTC 23891^T = CCUG 62216^T).     

<Emphasis Type="Italic">Oceaniovalibus guishaninsula</Emphasis> gen. nov., sp. nov., A Marine Bacterium of the Family <Emphasis Type="Italic">Rhodobacteraceae</Emphasis>

The alphaproteobacterial strain JLT2003^T was isolated from surface seawater off the coast of Guishan island, Taiwan. The strain was Gram negative, ovoid or coccoid, non-motile and formed pink colonies on marine agar 2216 (MA; DIFCO) medium. The dominant fatty acids were C_18:1ω7c, cyclo C_19:0ω8c, and C_16:0. The polar lipid profile consisted of diphosphatidylglycerol and phosphatidylglycerol. The major respiratory ubiquinone was Q-10. The DNA G+C content was 62.3 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that the strain was most closely related to Pontibaca methylaminivorans GRP21^T with 94.8% similarity. The isolate was distinguishable from members of the family Rhodobacteraceae based on phenotypic and biochemical characteristics. On the basis of the taxonomic data presented, strain JLT2003^T is considered to represent a novel species of a new genus, for which the name Oceaniovalibus guishaninsula gen. nov., sp. nov. is proposed. The type strain of Oceaniovalibus guishaninsula is JLT2003^T (=JCM 17765^T = CGMCC 1.10827^T).     

Altererythrobacter flava sp. nov., a new member of the family Erythrobacteraceae,isolated from a surface seawater sample

A Gram-stain-negative, light yellow pigmented, non-motile and aerobic bacterial strain, designated HHU E2-1 ^T, was isolated from a surface seawater sample. The 16S rRNA gene sequence analysis indicated that HHU E2-1 ^T shared the highest sequence similarity to the type strain Qipengyuania gaetbuli DSM 16225 ^T (96.90%), which belongs to the family Erythrobacteraceae. Combined phylogeny of 288 single-copy orthologous gene clusters, analysis of average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH), average amino acid identity (AAI) and evolutionary distances suggested that HHU E2-1 ^T can be considered as a member of the genus Altererythrobacter based on the recently proposed standard for defining genera of Erythrobacteraceae. Strain HHU E2-1 ^T grew at 15–35 °C and pH 5.0–8.0, with optimum growth at 28 °C and pH 7.0. Tolerance to NaCl was up to 4% (w/v) with optimum growth in 2–3% NaCl. The major fatty acids (>?10%) were C_18:1ω7c11-methyl, summed feature 3 (C_16:1ω7c and/or C_16:1ω6c), and summed feature 8 (C_18:1ω7c and/or C_18:1ω6c). The predominant isoprenoid quinone was ubiquinone-10. The genomic G?+?C content was 57.40%. On the basis of the phenotypic, phylogenetic and chemotaxonomic characterizations, HHU E2-1 ^T represents a novel species of the genus Altererythrobacter, for which the name Altererythrobacter flava sp. nov. is proposed. The type strain is HHU E2-1 ^T (=?CGMCC 1.17394 ^T?=?KCTC 72835 ^T?=?MCCC 1K04226^T).

     

Reduced diurnal temperature range does not change warming impacts on ecosystem carbon balance of Mediterranean grassland mesocosms

Daily minimum temperature (T_min) has increased faster than daily maximum temperature (T_max) in many parts of the world, leading to decreases in diurnal temperature range (DTR). Projections suggest that these trends are likely to continue in many regions, particularly in northern latitudes and in arid regions. Despite wide speculation that asymmetric warming has different impacts on plant and ecosystem production than equal‐night‐and‐day warming, there has been little direct comparison of these scenarios. Reduced DTR has also been widely misinterpreted as a result of night‐only warming, when in fact T_min occurs near dawn, indicating higher morning as well as night temperatures. We report on the first experiment to examine ecosystem‐scale impacts of faster increases in T_min than in T_max, using precise temperature controls to create realistic diurnal temperature profiles with gradual day–night temperature transitions and elevated early morning as well as night temperatures. Studying a constructed grassland ecosystem containing species native to Oregon, USA, we found that the ecosystem lost more carbon at elevated than ambient temperatures, but remained unaffected by the 3 °C difference in DTR between symmetric warming (constantly ambient + 3.5 °C) and asymmetric warming (dawn T_min = ambient + 5 °C, afternoon T_max = ambient + 2 °C). Reducing DTR had no apparent effect on photosynthesis, probably because temperatures were most different in the morning and late afternoon when light was low. Respiration was also similar in both warming treatments, because respiration temperature sensitivity was not sufficient to respond to the limited temperature differences between asymmetric and symmetric warming. We concluded that changes in daily mean temperatures, rather than changes in T_min/T_max, were sufficient for predicting ecosystem carbon fluxes in this reconstructed Mediterranean grassland system.