Search results for "Microbe"
showing 10 items of 114 documents
Seasonal and spatial dynamics of enteric viruses in wastewater and in riverine and estuarine receiving waters
2018
International audience; Enteric viruses represent a global public health threat and are implicated in numerous foodborne andwaterborne disease outbreaks. Nonetheless, relatively little is known of their fate and stability in the environment. In this studywe used carefully validatedmethods tomonitor enteric viruses, namely adenovirus (AdV), JC polyomavirus (JCV), noroviruses (NoVs), sapovirus (SaV) and hepatitis A and E viruses (HAV and HEV) fromwastewater source to beaches and shellfish beds. Wastewater influent and effluent, surface water, sediment and shellfish samples were collected in the Conwy catchment (North Wales, UK) once a month for one year. High concentrations of AdV and JCV wer…
How Hosts Taxonomy, Trophy, and Endosymbionts Shape Microbiome Diversity in Beetles.
2019
Bacterial communities play a crucial role in the biology, ecology, and evolution of multicellular organisms. In this research, the microbiome of 24 selected beetle species representing five families (Carabidae, Staphylinidae, Curculionidae, Chrysomelidae, Scarabaeidae) and three trophic guilds (carnivorous, herbivorous, detrivorous) was examined using 16S rDNA sequencing on the Illumina platform. The aim of the study was to compare diversity within and among species on various levels of organization, including evaluation of the impact of endosymbiotic bacteria. Collected data showed that beetles possess various bacterial communities and that microbiota of individuals of particular species h…
The janus face of NKT cell function in autoimmunity and infectious diseases
2018
Natural killer T cells (NKT) are a subset of T lymphocytes bridging innate and adaptive immunity. These cells recognize self and microbial glycolipids bound to non-polymorphic and highly conserved CD1d molecules. Three NKT cell subsets, type I, II and NKT-like expressing different antigen receptors (TCR) were described and TCR activation promotes intracellular events leading to specific functional activities. NKT can exhibit different functions depending on the secretion of soluble molecules and the interaction with other cell types. NKT cells act as regulatory cells in the defence against infections but, on the other hand, their effector functions can be involved in the pathogenesis of sev…
Native arbuscular mycorrhizal symbiosis alters foliar bacterial community composition.
2017
The effects of arbuscular mycorrhizal (AM) fungi on plant-associated microbes are poorly known. We tested the hypothesis that colonization by an AM fungus affects microbial species richness and microbial community composition of host plant tissues. We grew the grass, Deschampsia flexuosa in a greenhouse with or without the native AM fungus, Claroideoglomus etunicatum. We divided clonally produced tillers into two parts: one inoculated with AM fungus spores and one without AM fungus inoculation (non-mycorrhizal, NM). We characterized bacterial (16S rRNA gene) and fungal communities (internal transcribed spacer region) in surface-sterilized leaf and root plant compartments. AM fungus inoculat…
Chapter 12 Role of Iron in Plant–Microbe Interactions
2009
Iron is an essential micronutrient for plants and associated microorganisms. Iron nutrition of these organisms relies on the soil supply. However, bioavailability of iron in cultivated soils is low. Plants and microorganisms have thus evolved active strategies of iron uptake based on acidification, chelation, and/or reduction processes. Iron acquisition by these organisms leads to complex interactions ranging from mutualism to competition. In the rhizosphere, plants support abundant and active microbial communities through the release of rhizodeposits. Iron uptake by these microorganisms and by the host plant decrease even more the concentration of iron in solution. Therefore, there is an i…
Bacterial community response to changes in a tri-trophic cascade during a whole-lake fish manipulation
2015
Microbial communities play a key role in biogeochemical processes by degrading organic material and recycling nutrients, but can also be important food sources for upper trophic levels. Trophic cascades might modify microbial communities either directly via grazing or indirectly by inducing changes in other biotic or in abiotic factors (e.g., nutrients). We studied the effects of a tri-trophic cascade on microbial communities during a whole-lake manipulation in which European perch (Perca fluviatilis) were added to a naturally fishless lake divided experimentally into two basins. We measured environmental parameters (oxygen, temperature, and nutrients) and zooplankton biomass and studied th…
Arbuscular mycorrhizal fungi positively affect growth of Ailanthus altissima (Mill.) Swingle seedlings and show a strong association with this invasi…
2015
Arbuscular mycorrhizal fungi (AMF) may promote plant invasion by enhancing plant performance and competitiveness. However, only a small number of studies have considered the interactions between local soil microbial communities and invasive plants, and even fewer have focused on alien trees. Ailanthus altissima is a serious problem in the Mediterranean Basin, where it has invaded many habitats. We investigated the symbiosis between A. altissima and indigenous AMF in two invaded, ecologically different Mediterranean woodlands. Mycorrhizal infection was high at both sites (> 60% of the root fragments were mycorrhizal), indicating that A. altissima roots may be infected by AMF under different …
Dissection of the relative contribution of the Schizosaccharomyces pombe Ctr4 and Ctr5 proteins to the copper transport and cell surface delivery fun…
2011
The Ctr1 family of proteins mediates high-affinity copper (Cu) acquisition in eukaryotic organisms. In the fission yeastSchizosaccharomyces pombe, Cu uptake is carried out by a heteromeric complex formed by the Ctr4 and Ctr5 proteins. Unlike human andSaccharomyces cerevisiaeCtr1 proteins, Ctr4 and Ctr5 are unable to function independently in Cu acquisition. Instead, both proteins physically interact with each other to form a Ctr4–Ctr5 heteromeric complex, and are interdependent for secretion to the plasma membrane and Cu transport activity. In this study, we usedS. cerevisiaemutants that are defective in high-affinity Cu uptake to dissect the relative contribution of Ctr4 and Ctr5 to the Cu…
Minor changes in the macrocyclic ligands but major consequences on the efficiency of gold nanoparticles designed for radiosensitization
2016
International audience; Many studies have been devoted to adapting the design of gold nanoparticles to efficiently exploit their promising capability to enhance the effects of radiotherapy. In particular, the addition of magnetic resonance imaging modality constitutes an attractive strategy for enhancing the selectivity of radiotherapy since it allows the determination of the most suited delay between the injection of nanoparticles and irradiation. This requires the functionalization of the gold core by an organic shell composed of thiolated gadolinium chelates. The risk of nephrogenic systemic fibrosis induced by the release of gadolinium ions should encourage the use of macrocyclic chelat…
Spatial distribution of N-cycling microbial communities showed complex patterns in constructed wetland sediments.
2013
International audience; Constructed wetlands are used for biological treatment of wastewater from agricultural lands carrying pollutants such as nitrates. Nitrogen removal in wetlands occurs from direct assimilation by plants and through microbial nitrification and denitrification. We investigated the spatial distribution of N-cycling microbial communities and genes involved in nitrification and denitrification in constructed wetland sediments receiving irrigation water. We used quantitative real-time PCR (qPCR) to characterize microbial communities. Geostatistical variance analysis was used to relate them with vegetation cover and biogeochemical sediment properties. The spatial distributio…