Eudoraea adriatica gen. nov., sp. nov., a novel marine bacterium of the family Flavobacteriaceae

This is an author manuscript that has been accepted for publication in International Journal of Systematic and Evolutionary Microbiology, copyright Society for General Microbiology, but has not been copy-edited, formatted or proofed. Cite this article as appearing in International Journal of Systematic and Evolutionary Microbiology. This version of the manuscript may not be duplicated or reproduced, other than for personal use or within the rule of 'Fair Use of Copyrighted Materials' (section 17, Title 17, US Code), without permission from the copyright owner, Society for General Microbiology. The Society for General Microbiology disclaims any responsibility or liability for errors or omissions in this version of the manuscript or in any version derived from it by any other parties. The final copy-edited, published article, which is the version of record, can be found at http://mic.sgmjournals.org, and is freely available without a subscription.International audienceA novel aerobic, non-motile, Gram-negative bacterium, designated AS06/20a(T), was isolated from coastal waters of the Adriatic Sea and subjected to polyphasic taxonomic analysis. Cells were rod-shaped and formed non-pigmented punctiform colonies on agar plates. The novel isolate grew heterotrophically on a variety of carbon compounds, including organic acids, carbohydrates, polyols, amino acids and complex organic substrates. Cells grew at 15-33 degrees C (optimum 30 degrees C), pH 6.5-8.5 (optimum pH 7.5-8.0) and between 2 and 6 % (w/v) NaCl (optimum 2 %). The dominant fatty acids (>5 %) detected in strain AS06/20a(T) were iso-C(15 : 1) G, iso-C(15 : 0), iso-C(15 : 0) 3-OH, iso-C(17 : 1)omega9c and iso-C(17 : 0) 3-OH. The major respiratory quinone was MK-6. The G+C content of the genomic DNA was 38.9 mol%. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain AS06/20a(T) fell within the family Flavobacteriaceae in the phylum Bacteroidetes. Comparative 16S rRNA gene sequence analysis indicated that strain AS06/20a(T) was most closely related to members of the genera Zeaxanthinibacter and Robiginitalea, sharing 92-93 % 16S rRNA gene sequence similarity with representatives of these genera. It is proposed, from the results of the polyphasic taxonomic analysis, that the strain should be placed in a new genus, Eudoraea gen. nov., with Eudoraea adriatica sp. nov. as the type species. The type strain is AS06/20a(T) (=DSM 19308(T)=CIP 109577(T)=OOB 358(T))

Hellea balneolensis gen. nov., sp. nov., a prosthecate alphaproteobacterium from the Mediterranean Sea

This is an author manuscript that has been accepted for publication in International Journal of Systematic and Evolutionary Microbiology, copyright Society for General Microbiology, but has not been copy-edited, formatted or proofed. Cite this article as appearing in International Journal of Systematic and Evolutionary Microbiology. This version of the manuscript may not be duplicated or reproduced, other than for personal use or within the rule of 'Fair Use of Copyrighted Materials' (section 17, Title 17, US Code), without permission from the copyright owner, Society for General Microbiology. The Society for General Microbiology disclaims any responsibility or liability for errors or omissions in this version of the manuscript or in any version derived from it by any other parties. The final copy-edited, published article, which is the version of record, can be found at http://mic.sgmjournals.org, and is freely available without a subscription.International audienceA novel aerobic, heterotrophic, prosthecate bacterium, designated 26III/A02/215(T), was isolated from surface water of the north-western Mediterranean Sea. Cells stained Gram-negative and were straight to slightly curved rods, forming red colonies on agar plates. The strain grew at 15-37 degrees C inclusive (optimum 30 degrees C) and grew optimally at seawater salinity. Growth was observed on organic acids, amino acids and complex organic substrates. The fatty acids (>5 %) detected in strain 26III/A02/215(T) were C(17 : 1)omega6c, C(18 : 1)omega7c and C(17 : 0). The lipid pattern indicated the presence of phosphatidylglycerol, glucuronopyranosyldiglyceride, monoglycosyldiglyceride, an unidentified glycolipid and three unidentified phospholipids. Phosphatidylethanolamine and diphosphatidylglycerol were absent. Ubiquinone Q-10 was the only respiratory lipoquinone. The G+C content of the genomic DNA was 46.8 mol%. Comparative 16S rRNA gene sequence analysis indicated that strain 26III/A02/215(T) belonged to the Hyphomonas-Hirschia-Robiginitomaculum branch of the order Caulobacterales. This affiliation was consistent with the results of polar lipid analyses. Among this group, the novel isolate was most closely related to Robiginitomaculum antarcticum (93.9 % 16S rRNA gene sequence similarity to the type strain). On the basis of genotypic, chemotaxonomic and phenotypic distinctness, we propose a novel genus, Hellea gen. nov., with Hellea balneolensis sp. nov. as the type species. The type strain of Hellea balneolensis is 26III/A02/215(T) (=DSM 19091(T) =CIP 109500(T) =OOB 269(T))

Proteogenomic analysis of Epibacterium mobile BBCC367, a relevant marine bacterium isolated from the South Pacific Ocean

Epibacterium mobile BBCC367 is a marine bacterium that is common in coastal areas. It belongs to the Roseobacter clade, a widespread group in pelagic marine ecosystems. Species of the Roseobacter clade are regularly used as models to understand the evolution and physiological adaptability of generalist bacteria. E. mobile BBCC367 comprises two chromosomes and two plasmids. We used gel-free shotgun proteomics to assess its protein expression under 16 different conditions, including stress factors such as elevated temperature, nutrient limitation, high metal concentration, and UVB exposure. Comparison of the different conditions allowed us not only to retrieve almost 70% of the predicted proteins, but also to define three main protein assemblages: 584 essential core proteins, 2,144 facultative accessory proteins and 355 specific unique proteins. While the core proteome mainly exhibited proteins involved in essential functions to sustain life such as DNA, amino acids, carbohydrates, cofactors, vitamins and lipids metabolisms, the accessory and unique proteomes revealed a more specific adaptation with the expression of stress-related proteins, such as DNA repair proteins (accessory proteome), transcription regulators and a significant predominance of transporters (unique proteome). Our study provides insights into how E. mobile BBCC367 adapts to environmental changes and copes with diverse stresses

Biofouling Growth in Cold Estuarine Waters and Evaluation of Some Chitosan and Copper Anti-Fouling Paints

Ecological concerns about antifouling paints containing non-green tin and copper compounds have highlighted the need for environmentally friendly alternatives. We report here a field test conducted in estuarine waters over two months designed to evaluate the efficiency of a number of active natural and man-made chemical ingredients added into a silicon-polyurethane marine paint. Early steps of biofouling in cold seawater of the St. Lawrence Estuary (Canada) were observed. Analyses, including dry biomass, flow cytometry and spectrofluorimetry, demonstrated a short-term antibacterial action of chitosan-based paints although no significant anti-algal action was observed. Cuprous oxide paints were efficient against bacteria and algae invasion in the first two weeks, especially those with added organic biocides such as isothiazolone and copper pyrithione. However, the overall dry biomass and chlorophyll a content were similar for all chitosan-and copper-based paints after 63 days. Microscopic observations revealed variation in the highly diverse benthic diatom population including species Navicula, Melosira, Cocconeis, Nitshzcia, Fragilaria and Amphora. Results suggest no real long-term efficiency for tested antifouling paints and highlight a particular need for green antifouling ingredients that are active under northern estuarine conditions

Assessing the occurrence and the toxicity of Fos embayment's chlorination by-products

La chloration est l'une des techniques les plus utilisées pour la désinfection de l'eau et est également considérée comme l'un des traitements les plus efficaces disponibles pour le contrôle du biofouling. Cependant, le chlore est très réactif vis-à-vis des matières organiques naturelles, de l'ammonium et du bromure présents dans l'eau de mer. Les réactions du chlore avec ces espèces conduisent à la formation de plusieurs sous-produits bromés appelés des sous-produits de chloration (SPC), dont la nature, les concentrations et les écotoxicités sont peu documentés dans la littérature. Ce travail vise à évaluer l’occurrence et les impacts des rejets chlorés dans une zone fortement industrialisée, située dans une baie semi-fermée du sud-est de la France. Six campagnes d'échantillonnage en mer ont été menées entre 2017 et 2019. Un niveau total de sous-produits de chloration de l’ordre du microgramme par litre a été mesuré. Les familles de SPC principalement retrouvées sont les trihalométhanes, les acides haloacétiques, les haloacétonitriles et les halophénols. Parallèlement, la toxicité et la génotoxicité ont été mesurées sur des larves de l’oursin Méditerranéen Paracentrotus lividus. Les trois principales molécules bromées retrouvées dans le golfe commencent à être toxique à des concentrations de l’ordre du milligramme par litre. Cependant, une tolérance au bromoforme chez les larves issues d’oursins adultes prélevés dans le golfe de Fos a été démontrée. Cela indique que les populations du golfe de Fos sont probablement adaptées pour contrer les effets de l’exposition chronique à la multi-pollution.Chlorination is one of the most widely used techniques for water disinfection et is also considered as one of the most effective treatments available for the control of biological fouling. However, chlorine reacts very well to natural organic matter, ammonium et bromide, all present in seawater. The reactions of chlorine with these species lead to the formation of several bromine by-products called disinfection by-products (SPC), which nature, concentrations et ecotoxicity of which are poorly documented. This study aims to assess the levels et impacts of chlorinated discharges in a highly industrialized area located in a semi-enclosed bay in Southeastern France. In this zone, the total quantity of daily releases is estimated to reach 6 million cubic meters of chlorinated water. Six sampling campaigns at sea were conducted between 2017 et 2019. A total level of disinfection by-products of the order of micrograms per liter was measured. The main families of SPC found were trihalomethanes (THMs), haloacetic acids (AHA), haloacetonitriles (HAN) et halophenols (HP). At the same time, acute toxicity et genotoxicity were measured on sea urchin larvae Paracentrotus lividus. The three main brominated molecules, all present in the different matrices of the Fos, start to be toxic et genotoxic, at concentrations close to milligram per liter. However, the higher tolerance to bromoform, of larvae produced by adult sea urchins caught in the Gulf of Fos, compared to larvae of adults living in unpolluted areas, has been demonstrated. This indicates that populations living in Fos, are likely adapted to counteract the effects of a chronic exposure to multiple pollution

Origine, devenir et détection rapide de microorganismes entériques pathogènes à l'interface côtière (une application aux genres Salmonella et Cryptosporidium)

De nombreux microorganismes potentiellement pathogènes pour l'homme et les animaux sont présents à l'interface côtière, où ils peuvent avoir des implications importantes en terme de santé publique, comme en terme d'activité socio-économiques. Les difficultés inhérentes à la détection des pathogènes par les techniques classiques de mise en culture (i.e. temps, formes non cultivables) nécessitent le développement de méthodes alternatives permettant la quantification rapide de pathogène spécifiques en milieu naturel. Les travaux réalisés ont permis d'utiliser une méthode directe, couplée à une détection par cytométrie en phase solide, pour quantifier des oocystes de Cryptosporidium dans différents types d'eau, mais restent encore à être affinés dans le cas particulier des bactéries. L'analyse de la contamination du bassin versant du Tech (Pyrénées-Orientales, France) n'a pas permis d'établir une relation quantitative entre Salmonella, Cryptosporidium et deux indicateurs de pollution fécale (e.g. coliformes thermotolérants, streptocoques fécaux). Elle confirme la nécessité de rechercher les germes pathogènes de façon spécifique dans les eaux de surface. Les flux de pathogènes à l'interface côtière peuvent être direct ou diffus. Les apports diffus sont contrôlés par la fréquence de mobilisation des sources, animales ou humaines, de contamination et par la capacité de résistance des organismes face aux facteurs biotiques et abiotiques (e.g. salinité, rayonnement).L'analyse de la survie de sérotypes de "Salmonella enterica" provenant d'origines diverses démontre un comportement physiologique similaire pour l'ensemble des souches, conduisant à l'apparition de formes actives non cultivables. Une des hypothèses proposées afin de mieux comprendre les mécanismes à l'origine de la récurrence de certains sérotypes de "Salmonella enterica" en milieu fluvial, consiste en une sélection de cellules mutantes mieux adaptées aux conditions environnementales.LYON1-BU.Sciences (692662101) / SudocBANYULS/MER-Observ.Océanol. (660162201) / SudocSudocFranceF

Environnement et micro-organismes pathogènes de l'Homme: Chapitre 15

info:eu-repo/semantics/publishe

Environmental and Human Pathogenic Microorganisms

As the study of interactions between pathogenic microorganisms and their environment is part of microbial ecology, this chapter reviews the different types of human pathogens found in the environment, the different types of fecal indicators used in water quality monitoring, the biotic and abiotic factors affecting the survival and the infectivity of pathogenic microorganisms during their transportation in the environment, and the methods presently available to detect rare microorganisms in environmental samples. This chapter exclusively focuses on human pathogens.SCOPUS: ch.binfo:eu-repo/semantics/publishe

Assessment of individual and mixed toxicity of bromoform, tribromoacetic-acid and 2,4,6 tribromophenol, on the embryo-larval development of Paracentrotus lividus sea urchin

International audienceWater chlorination is the most widely used technique to avoid microbial contamination and biofouling. Adding chlorine in bromide-rich waters leads to the rapid oxidation of bromide ions and leads to the formation of brominated disinfection by products (bromo-DBPs) that exert adverse effects on various biological models. Bromo-DBPs are regularly encountered within industrialized embayments, potentially impacting marine organisms. Of these, bromoform, tribromoacetic acid and tribromophenol are among the most prevalent. In the present study, we tested the potential toxicity and genotoxicity of these disinfection by-products, using sea urchin, Paracentrotus lividus, embryos. We highlighted that tribromophenol showed higher toxicity compared to bromoform and tribromoacetic acid. Furthermore, a synergistic effect was detected when tested in combination. Pluteus cells exposed for 1h to mixtures of DPBs at several concentrations demonstrated significant DNA damage. Finally, when compared to a non-exposed population, sea urchins living in a bromo-DPB-polluted area produced more resistant progenies, as if they were locally adapted. This hypothesis remains to be tested in order to better understand the obvious impact of bromo-DBPs environments on marine wildlife