Cellular responses of Pacific oyster (Crassostrea gigas) gametes exposed in vitro to polystyrene nanoparticles.

While the detection and quantification of nano-sized plastic in the environment remains a challenge, the growing number of polymer applications mean that we can expect an increase in the release of nanoplastics into the environment by indirect outputs. Today, very little is known about the impact of nano-sized plastics on marine organisms. Thus, the objective of this study was to investigate the toxicity of polystyrene nanoplastics (NPs) on oyster (Crassostrea gigas) gametes.

Development of an Effective 6-Methylpurine Counterselection Marker for Genetic Manipulation in Thermococcus barophilus.

A gene disruption system for was developed using simvastatin (HMG-CoA reductase encoding gene) for positive selection and 5-Fluoroorotic acid (5-FOA), a gene for negative selection. Multiple gene mutants were constructed with this system, which offers the possibility of complementation in trans, but produces many false positives (<80%). To significantly reduce the rate of false positives, we used another counterselective marker, 6-methylpurine (6-MP), a toxic analog of adenine developed in , consistently correlated with the gene (encoding a hypoxanthine-guanine phosphoribosyl-transferase).

Significance of metallothioneins in differential cadmium accumulation kinetics between two marine fish species.

Impacted marine environments lead to metal accumulation in edible marine fish, ultimately impairing human health. Nevertheless, metal accumulation is highly variable among marine fish species. In addition to ecological features, differences in bioaccumulation can be attributed to species-related physiological processes, which were investigated in two marine fish present in the Canary Current Large Marine Ecosystem (CCLME), where natural and anthropogenic metal exposure occurs.

Phylogenetic position of the enigmatic deep-sea nematode order Rhaptothyreida: A molecular analysis.

The placement of the rare deep-sea nematode order Rhaptothyreida remains unclear due to the unique morphology of this group, an unknown life cycle with morphologically distinct juvenile stages which may or may not be parasitic, and lack of molecular sequences. Here, we investigate the phylogenetic placement and status of the Rhaptothyreida based on SSU and D2-D3 of LSU rDNA sequences of Rhaptothyerus typicus specimens obtained from the continental slope of New Zealand. Molecular sequences of three adults and a late stage juvenile were identical, confirming that they belong to the same species despite pronounced morphological differences.

Complete Genome Sequence of the Halophilic Methylotrophic Methanogen Archaeon Strain FDF-1.

We report here the complete genome sequence (2.08 Mb) of strain FDF-1, a halophilic methylotrophic methanogen isolated from the sediment of a saltern in Figeria da Foz, Portugal. The average nucleotide identity and DNA-DNA hybridization analyses show that , , and are three different species within the family.

Method for High Frequency Underway N Fixation Measurements: Flow-Through Incubation Acetylene Reduction Assays by Cavity Ring Down Laser Absorption Spectroscopy (FARACAS).

Because of the difficulty in resolving the large variability of N fixation with current methods which rely on discrete sampling, the development of new methods for high-resolution measurements is highly desirable. We present a new method for high-frequency measurements of aquatic N fixation by continuous flow-through incubations and spectral monitoring of the acetylene (CH a substrate analog for N) reduction to ethylene (CH). In this method, named Flow-through Incubation Acetylene Reduction Assays by Cavity Ring-Down Laser Absorption Spectroscopy (FARACAS), dissolved CH is continuously admixed with seawater upstream of a continuous-flow stirred-tank reactor (CFSR) in which CH reduction takes place.

Complete Genome Sequence of Hyperthermophilic Archaeon sp. EXT12c, Isolated from the East Pacific Rise 9°N.

We report the genome sequence of sp. EXT12c isolated from a deep-sea hydrothermal vent at the East Pacific Rise 9°N. Microbes in the genus are able to grow anaerobically at high temperature, around neutral pH, and some of them under high hydrostatic pressure.

Two viruses, MCV1 and MCV2, which infect Marinitoga bacteria isolated from deep-sea hydrothermal vents: functional and genomic analysis.

Viruses represent a driving force in the evolution of microorganisms including those thriving in extreme environments. However, our knowledge of the viral diversity associated to microorganisms inhabiting the deep-sea hydrothermal vents remains limited. The phylum of Thermotogae, including thermophilic bacteria, is well represented in this environment.

An Unprecedented Blue Chromophore Found in Nature using a "Chemistry First" and Molecular Networking Approach: Discovery of Dactylocyanines A-H.

Guided by a "chemistry first" approach using molecular networking, eight new bright-blue colored natural compounds, namely dactylocyanines A-H (3-10), were isolated from the Polynesian marine sponge Dactylospongia metachromia. Starting from ilimaquinone (1), an hemisynthetic phishing probe (2) was prepared for annotating and matching structurally related natural substances in D. metachromia crude extract network.

Environmental life cycle assessment of seafood production: A case study of trawler catches in Tunisia.

The Gulf of Gabes is one of the most productive fishery areas in the southern Mediterranean Sea. It is archetypal of an ecosystem in which the effects of fisheries are most pronounced. Demersal trawling is the main fishing activity in the Gulf of Gabes.

Draft Genome Sequence of Type Strain 306, an Alphaproteobacterium Isolated from Mediterranean Sea Sediments.

strain 306 is an alphaproteobacterium isolated from Mediterranean Sea sediments. It belongs to the genus , which was recently proposed and is still poorly characterized. In an effort to better understand the fundamental aspects of the microbiology of this genus, we present here the 4.

Contrasting patterns of energy metabolism in northern vs southern peripheral European flounder populations exposed to temperature rising and hypoxia.

A two months common garden experiment was carried out to explore the potential differences of energy metabolism in northern core (France, 50°N and 47°N) vs southern peripheral (Portugal, 41°N) populations of European flounder Platichthys flesus, submitted to cold condition (CC: water temperature = 10 °C) and to warm and hypoxic condition (WHC: water temperature = 22 °C, and moderate hypoxia with O saturation = 40% during the last 6 days). Convergent growth rates (in length) were observed in the different populations and conditions, when the southern peripheral population of Portugal did not grow under cold conditions. A general reduction in liver lipid storage was observed in all populations subjected to WHC when compared to CC, whereas muscle lipid storage was unaffected.

Draft Genome of RHS90, a Stress-Tolerant Gammaproteobacterium Isolated from Mediterranean Sea Sediments.

Members of the genus are physiologically versatile and harbor ecological adaptations enabling the colonization of contrasted environments. We present here the draft genome of RHS90, isolated from Mediterranean Sea sediments. Numerous genes related to stress tolerance, DNA repair, or external signal-sensing systems were predicted, which could represent selective advantages of this marine bacterium.

Mitigating thermal effect of behaviour and microhabitat on the intertidal snail Littorina saxatilis (Olivi) over summer.

High shore intertidal ectotherms must withstand temperatures which are already close, at or beyond their upper physiological thermal tolerance. Their behaviour can provide a relief under heat stress, and increase their survival through thermoregulation. Here, we used infrared imaging to reveal the thermoregulatory behavioural strategies used by the snail Littorina saxatilis (Olivi) on different microhabitats of a high shore boulder field in Finistère (western France) in summer.

Proteomic responses of European flounder to temperature and hypoxia as interacting stressors: Differential sensitivities of populations.

In the context of global change, ectotherms are increasingly impacted by abiotic perturbations. Along the distribution area of a species, the populations at low latitudes are particularly exposed to temperature increase and hypoxic events. In this study, we have compared the proteomic responses in the liver of European flounder populations, by using 2-D electrophoresis.

Complete Genome Sequence of DSM 3094, Isolated from a Cyanobacterial Mat and Bottom Deposits at Hamelin Pool, Shark Bay, Northwestern Australia.

The complete genome sequence of DSM 3094, a member of the family and the order, consists of 2,022,959 bp in one contig and contains 2,137 predicted genes. The genome is consistent with a halophilic methylotrophic anaerobic lifestyle, including the methylotrophic and CO-H methanogensis pathways.

Desulfurobacterium indicum sp. nov., a thermophilic sulfur-reducing bacterium from the Indian Ocean.

A novel sulfur-reducing bacterium, strain K6013T, was isolated from a sulfide sample collected at a depth of 2771 m from a high-temperature hydrothermal vent in the Indian Ocean. Cells were Gram-stain-negative, anaerobic, motile rods (0.9-2.

Complete genome sequence and whole-genome phylogeny of type strain SLHLJ1 from an East Pacific hydrothermal sediment.

strain SLHLJ1 is a thermophilic chemoorganoheterotrophic bacterium isolated from a deep-sea hydrothermal sediment. It belongs to the physiologically homogeneous family. Here, we describe the phenotypic features of together with its genome sequence and annotation.

Ancestry and adaptive evolution of anadromous, resident, and adfluvial rainbow trout () in the San Francisco bay area: application of adaptive genomic variation to conservation in a highly impacted landscape.

The streams draining of into San Francisco Bay, California, have been impacted by habitat alteration for over 150 years, and roads, dams, water diversions, and other impediments now block the paths of many aquatic migratory species. These changes can affect the genetic structure of fish populations, as well as driving adaptive evolution to novel environmental conditions. Here, we determine the evolutionary relationships of San Francisco Bay Area steelhead/rainbow trout () populations and show that (i) they are more closely related to native coastal steelhead than to the California Central Valley lineage, with no evidence of introgression by domesticated hatchery rainbow trout, (ii) populations above and below barriers within watersheds are each other's closest relatives, and (iii) adaptive genomic variation associated with migratory life-history traits in shows substantial evolutionary differences between fish above and below dams.

Combined Whole-Cell High-Throughput Functional Screening for Identification of New Nicotinamidases/Pyrazinamidases in Metagenomic/Polygenomic Libraries.

Nicotinamidases catalyze the hydrolysis of the amide bond in nicotinamide (NAM) to produce ammonia and nicotinic acid (NA). These enzymes are an essential component of the NAD salvage pathway and are implicated in the viability of several pathogenic organisms. Its absence in humans makes them a promising drug target.

Lipid remodelling in the reef-building honeycomb worm, Sabellaria alveolata, reflects acclimation and local adaptation to temperature.

Acclimation and adaptation, which are key to species survival in a changing climate, can be observed in terms of membrane lipid composition. Remodelling membrane lipids, via homeoviscous adaptation (HVA), counteracts membrane dysfunction due to temperature in poikilotherms. In order to assess the potential for acclimation and adaptation in the honeycomb worm, Sabellaria alveolata, a reef-building polychaete that supports high biodiversity, we carried out common-garden experiments using individuals from along its latitudinal range.

Thermococcus piezophilus sp. nov., a novel hyperthermophilic and piezophilic archaeon with a broad pressure range for growth, isolated from a deepest hydrothermal vent at the Mid-Cayman Rise.

A novel strictly anaerobic, hyperthermophilic archaeon, designated strain CDGS, was isolated from a deep-sea hydrothermal vent in the Cayman Trough at 4964m water depth. The novel isolate is obligate anaerobe and grows chemoorganoheterotrophically with stimulation of growth by sulphur containing compounds. Its growth is optimal at 75°C, pH 6.

Trophic ecology influence on metal bioaccumulation in marine fish: Inference from stable isotope and fatty acid analyses.

The link between trophic ecology and metal accumulation in marine fish species was investigated through a multi-tracers approach combining fatty acid (FA) and stable isotope (SI) analyses on fish from two contrasted sites on the coast of Senegal, one subjected to anthropogenic metal effluents and another one less impacted. The concentrations of thirteen trace metal elements (As, Cd, Co, Cr, Cu, Fe, Li, Mn, Ni, Pb, Sn, U, and Zn) were measured in fish liver. Individuals from each site were classified into three distinct groups according to their liver FA and muscle SI compositions.