Search results for " RR"
showing 10 items of 133 documents
Natural soil reservoirs for human pathogenic and fecal indicator bacteria
2015
Prod ? EA UB INRA BIOME; International audience; résumé du livre : Environmental microbiology, the study of the roles that microbes play in all planetary environments, is one of the most important areas of scientific research. The The Manual of Environmental Microbiology, Fourth Edition, provides comprehensive coverage of this critical and growing field. Thoroughly updated and revised, the Manuall is the definitive reference for information on microbes in air, water, and soil and their impact on human health and welfare. Written in accessible, clear prose, the manual covers four broad areas: general methodologies, environmental public health microbiology, microbial ecology, and biodegradati…
Legacy effects of contrasting water and N-availability patterns on plantmicrobial response to rewetting
2019
National audience; Introduction. Shifts in the frequency and magnitude of rain events (precipitation regime) associated with climate change may affect plant morphological and physiological strategies as well as soil microbial activity.Objectives. The objective of this study was to determine i) how precipitation history shapes the response dynamics of soil bacterial and fungal communities to rewetting, as well as plant-microbial competition for N, and ii) how the N status of the system may modulate the effect of precipitation regime.Materials & methods. The legacy effects of 12 weeks of contrasting precipitation (frequent or infrequent watering, equal total water input) and N inputs was asse…
Different Medicago truncatula genotypes, expressing different phenotypes, modulate microbial functional genes in the rhizosphere
2022
Plants host in their rhizosphere a remarkable diversity of microorganisms that in return promote plant growth and health. Thus, the plant microbiota emerges as a novel component that expand the capacity of plants to adapt to the environment, and thus pave the way for future breeding approaches.It is widely known that different plant species harbor different microbiota, but very few studies showed an impact of the plant genotypes on the microbiota. These contrasting results may depend on the choice of the tested genotypes.We formulate the hypothesis that only those plant genotypes showing high genetic diversity and expressing different phenotypes harbor different rhizosphere microbiota and a…
Effects of hydrostatic pressure on yeasts isolated from deep-sea hydrothermal vents
2015
International audience; Hydrostatic pressure plays a significant role in the distribution of life in the biosphere. Knowledge of deep-sea piezotolerant and (hyper)piezophilic bacteria and archaea diversity has been well documented, along with their specific adaptations to cope with high hydrostatic pressure (HHP). Recent investigations of deep-sea microbial community compositions have shown unexpected micro-eukaryotic communities, mainly dominated by fungi. Molecular methods such as next-generation sequencing have been used for SSU rRNA gene sequencing to reveal fungal taxa. Currently, a difficult but fascinating challenge for marine mycologists is to create deep-sea marine fungus culture c…
Cilvēka asins mikrobioma kompozīcijas, stabilitātes un izcelsmes noteikšana veselos indivīdos
2021
Neseni pētījumi ir apliecinājuši asins mikrobioma klātesamību veselos cilvēkos, tomēr tā izcelsme vēl ir neskaidra. Maģistra darba mērķis bija noskaidrot asins mikrobioma kompozīciju, potenciālo izcelsmi un dinamiku laika gaitā veseliem indivīdiem. Asins mikrobioma izcelsmes noskaidrošanai 10 veseliem indivīdiem ievāca pilnasins paraugus un ādas, maksts, mutes un fēču mikrobioma uztriepes. Pilnasins un fēču paraugus ievāca no diviem laika punktiem ar 3 mēnešu intervālu. Ar 16S rRNS gēna V3-V4 reģiona analīzi noteica to taksonomisko sastāvu. Noskaidrojās, ka asins mikrobioms ir unikāls - tajā izteikti dominē Proteobacteria tipa Pseudomonas ģints pārstāvji, un vienlaikus tā potenciālā izcelsm…
Pyrosequencing survey of intestinal microbiota diversity in cultured sea bass (Dicentrarchus labrax) fed functional diets.
2014
The routine use of chemotherapy to control bacterial diseases in aquatic populations has resulted in the development and spread of antibiotic resistance. The inclusion of immunostimulants in fish diets (functional diets) is one of the main strategies to solve this threat. This study aimed to analyse the intestinal microbiota of cultured European sea bass (Dicentrarchus labrax) fed two functional diets applying pyrosequencing of PCR-amplified 16S rRNA gene. Quality-filtered reads were assigned to family and genus taxonomic levels using the Ribosomal Database Project classifier. The autochthonous intestinal microbiota of sea bass consisted of two dominant bacterial genera: Dysgonomonas (Bacte…
Pole-to-Pole Connections : Similarities between Arctic and Antarctic Microbiomes and Their Vulnerability to Environmental Change
2017
The global biogeography of microorganisms remains poorly resolved, which limits the current understanding of microbial resilience toward environmental changes. Using high-throughput 16S rRNA gene amplicon sequencing, we characterized the microbial diversity of terrestrial and lacustrine biofilms from the Arctic, Antarctic and temperate regions. Our analyses suggest that bacterial community compositions at the poles are more similar to each other than they are to geographically closer temperate habitats, with 32% of all operational taxonomic units (OTUs) co-occurring in both polar regions. While specific microbial taxa were confined to distinct regions, representing potentially endemic popul…
Differential responses of bacterial and archaeal groups at high taxonomical ranks to soil management
2010
Little is known about abundances of the major bacterial taxa in agricultural soils and how they are affected by fertilization or other agricultural practices. Our aim was to determine the abundance and relative distribution of several bacterial phyla and one class, as well as the archaeal and crenarchaeal communities, and how they were affected by different fertilization regimes to examine whether specific responses of microorganisms could be identified at these high taxonomic ranks. We used real-time PCR with taxa specific primers to quantify the abundance of the Actinobacteria, Acidobacteria, Bacteriodetes, Firmicutes, Gemmatimonadetes, Verrucomicrobia, Alphaproteobacteria and Crenarchaeo…
Vertical stratification of bacteria and archaea in sediments of a small boreal humic lake
2019
Taxonomical and Functional Assessment of the Endometrial Microbiota in A Context of Recurrent Reproductive Failure: A Case Report
2019
Investigation of the microbial community in the female reproductive tract has revealed that the replacement of a community dominated by Lactobacillus with pathogenic bacteria may be associated with implantation failure or early spontaneous abortion in patients undergoing assisted reproductive technology (ART) treatment. Herein we describe taxonomically and functionally the endometrial microbiome of an infertile patient with repeated reproductive failures (involving an ectopic pregnancy and two clinical miscarriages). The microbiological follow-up is presented over 18-month in which the microbiota was evaluated in six endometrial fluid samples. The microbial profile of 16S rRNA gene sequenci…