Search results for "Microbe"

Aquaculture impact on benthic microbes and organic matter cycling in coastal Mediterranean sediments: a synthesis

2003

Microbial assemblages and organic matter composition as well as their response to the disturbance induced by mussel and fish-farm biodeposition were compared in several areas of the Mediterranean: La Spezia (Ligurian Sea), Gaeta (Tyrrhenian Sea), Cattolica (Adriatic Sea) and Cyprus (Levantine Sea), on both unvegetated and Posidonia bed sediments. In all systems investigated, organic matter (as biopolymeric carbon) accumulated in aquaculture impacted sediments. Among the main biochemical classes, lipids appeared to be a good tracer of aquaculture impact, especially in fish-farm sediments. Exoenzymatic activities displayed higher values in sediment beneath the cages, indicating faster organic…

PFGE: importance in food quality.

2010

In late 19 century, great interest has arisen for food quality. This is referred as absence of pathogens in food (safety for consumers) and as nutritional quality of food (organoleptic characteristics). Pulsed-field gel electrophoresis (PFGE) is, among the molecular techniques developed in the last years, one of the most reliable, discriminative and reproducible technique. It can be used in clinical field for the identification of pathogens and the origin of outbreaks, and in food microbiology for the identification of pathogens (food borne disease surveillance) or of microorganisms responsible for the organoleptic characteristics of food. The present article shows some useful patents relat…

Design and prototyping of a magnetic actuator based permanent magnets for microbead navigation in viscous environment

2017

International audience; For actuating the magnetic microrobots, two types of magnetic actuation technologies have been used during the last past years. These magnetic technologies may be either electromagnetic coils or permanent magnets based systems. This second solution is not the most used by researchers, because of the difficulties to control the magnetic force. In this paper we propose a magnetic actuator prototype based on permanent magnets. In addition to the magnets, the actuator is also composed of a mechanical structure. This structure is used for positioning the permanent magnets, which allows to control the magnetic force generated by the actuator. We demonstrated in simulation …

Mechanisms of beneficial legume-microbe interactions

2013

Understanding mechanisms underlying high nutrients use efficiency and carbon allocation in a context of legumes-microbe interactions at the root level (mycorrhiza and nodules) is critical for sound management of croplands taking care of ecosystem services rendered by beneficial microbes. Indeed, availability, uptake and exchange of nutrients in biotrophic interactions will drive plant growth and modulate biomass allocation, that are central to plant yield, a major outcome, in the context of high biomass production. Transport processes across the polarised membrane interfaces are of major importance in the functioning of the established symbiosis as the relation is based on a 'fair-trade' be…

Toward the Identification of Two Glycoproteins Involved in the Stomatal Deregulation of Downy Mildew–Infected Grapevine Leaves

2015

SPE Pôle IPM UB; International audience; Stomata remain abnormally opened and unresponsive to abscisic acid in grapevine leaves infected by downy mildew. This deregulation occurs from 3 days post inoculation and increases concomitantly with leaf colonization by the pathogen. Using epidermal peels, we demonstrated that the active compound involved in this deregulation is located in the apoplast. Biochemical assays showed that the active compound present in the apoplastic fluids isolated from Plasmopara viticola infected grapevine leaves (IAF) is a CysCys bridge-independent, thermostable and glycosylated protein. Fractionation guided assays based on chromatography / stomatal response and prot…

Identification of the VvFLS2 grapevine flagellin receptor by a functional genomics strategy

2013

National audience; Grapevine (Vitis vinifera) is a crop of high agronomic interest subject to many destructive diseases. Pattern recognition receptors (PRRs) mediate detection of potential pathogens via the perception of pathogen associated molecular patterns (PAMPs), which is important for plant disease resistance. A well studied PRR is the Arabidopsis leucine-rich repeat receptor kinase FLS2 that recognizes bacterial flagellin (or its minimal motif flg22). Flagellin perception plays an important role in restricting bacterial invasion into plant leaves. Until now, functional FLS2 orthologues have been characterized in Nicotiana benthamiana, rice and tomato. Despite its economical importanc…

Mapping spatial patterns of denitrifiers for bridging community ecology and microbial processes along environmental gradients

2009

International audience; While there is ample evidence that microbial processes can exhibit large variations at a field scale, very little is known about the spatial distribution of the communities mediating these processes. The objective of this study was to explore spatial patterns of size and activity of the denitrifying community, a functional guild involved in N-cycling, in a grassland field subjected to different cattle grazing regimes. We used geostatistical modeling to map the distribution of size and activity of the denitrifier community in the pasture. Size of the denitrifier community was estimated by PCR quantification of the denitrification gene copy numbers while its activity w…

Mapping spatial patterns of denitrifiers for bridging community ecology and microbial processes along environmental gradients

2009

While there is ample evidence that microbial processes can exhibit large variations at a field scale, very little is known about the spatial distribution of the communities mediating these processes. The objective of this study was to explore spatial patterns of size and activity of the denitrifying community, a functional guild involved in N-cycling, in a grassland field subjected to different cattle grazing regimes. We used geostatistical modeling to map the distribution of size and activity of the denitrifier community in the pasture. Size of the denitrifier community was estimated by PCR quantification of the denitrification gene copy numbers while its activity was estimated by measurin…

Comment stimuler l’immunité de la vigne avec des éliciteurs

2013

Etude des interactions plantes-microbes et microbes-microbes au sein de la rhizosphère, sous un aspect coûts-bénéfices, dans un contexte de variation…

2013

Understanding the interactions that bind plants and soil microorganisms is an essential step for the sustainable management of ecosystems, especially in agriculture. The ecosystem services resulting from such interactions include plant productivity which responds, in part, to the food requirements of the world's population and the regulation of biogeochemical cycles. These ecosystem services depend on trophic links between the two partners in the interaction and can be represented by a tradeoff between the costs and benefits for each partner. Plants, being autotrophic organisms or primary producers, are key organisms which introduce carbon into the ecosystem, through photosynthesis. Part of…