Search results for "MICROBIAL COMMUNITIES"
showing 9 items of 49 documents
Impact des systèmes de culture en protection intégrée contre les adventices sur l'intensité des émissions de N2O par les sols
2013
Temporal dynamics of soil bacterial communities at a landscape scale: dependence to soil properties and agricultural practices.
2019
International audience; Soil microbial communities play a major role in agricultural functions and are an efficient indicator to evaluate the impacts of agricultural practices on soils. Studies on wide scales ranging from landscape to countries demonstrated that soil microbial communities were heterogeneously distributed in space under the dependence of soil properties (e.g. pH, soil texture, Organic matter Content) and agricultural practices. However, temporal dynamics of soil microbial communities at a landscape scale still need to be documented in order to go further in evaluating the sustainability of agricultural practices. In this extensive monitoring study, we focused on landscape dy…
Deciphering biotic interactions and their role in soil microbial community assembly and functions: using community manipulation to steer soil microbi…
2022
Microbial communities play a key role in ecosystem functioning as well as in plant, animal, and human welfare. Their assembly relies on different processes commonly referred to as abiotic and biotic filters. Despite the widespread emphasis on abiotic filters in terrestrial ecosystems, a growing body of evidence suggests that interactions between microorganisms play a critical role in community assembly. However, the contribution of these interactions to microbial community assembly and the factors influencing them have not been clearly established. In most cases, biotic interactions between microorganisms have been investigated based on cocultures of a handful of strains, completely overloo…
Soil microbial diversity effects on primary production and symbiotic interactions
2013
SPEEAEcolDurGenoSolGEAPSI; The importance of telluric microorganisms linked together by trophic exchanges with plants, that sustain all ecosystems through primary production, is known. However, the role of soil microbial diversity for primary production remains controversial. A diversity decreasing was achieved, by inoculating a sterilized soil with serial dilutions of a suspension from the same non-sterilized soil, to determine the consequences of microbial diversity erosion on the growth and fitness of three plant species more or less dependent on symbionts, Medicago truncatula, Brachypodium distachyon and Arabidopsis thaliana. The results showed that the impact of microbial diversity dec…
Impact of anaerobic digestates on microbial communities of agricultural soils
2022
Anaerobic digestion of organic waste is considered as a key process to produce renewable energy to meet the growing sustainable energy demand. The residues of this anaerobic digestion, called digestates, can be used in agriculture as soil amendments and improve crop yields. However, the effect of digestates on soil biota, especially on microorganisms is still debated and needs to be better documented before their use at large scale in agricultural fields. The objective of the present thesis was to assess the effect of digestates on soil microbial community in different geographical and pedoclimatic contexts on the French territory. This thesis is divided in two parts. The first part takes p…
A new conceptual framework shows that plant genotype and soil nitrogen availability modify both plant nutritional strategies and diversity of their a…
2015
In the context of sustainable agriculture, it is desirable to lower the input of mineral fertilizers. Therefore, we need to select ‘new’ genotypes that are both adapted to ‘low fertilizer inputs’ and more efficient in nutrient use. A better understanding of plant-microbe interactions under low input of fertilizers is now needed. Nevertheless, in microbial ecology, conceptual frameworks or models are used to analyse plant-microbe interactions but plant phenotype is currently viewed as a “black box”. We developed a new conceptual framework to study plant-microbe interactions using a multidisciplinary approach combining Microbial Ecology and Plant Ecophysiology.The links among plant genotype, …
Diversity and complexity of microbial communities from a chlor-alkali tailings dump
2015
Abstract Revegetation of the tailings dumps produced by various industrial activities is necessary to prevent dust storms and erosion and represents a great challenge for ecological restoration. Little is known about the microbial colonisation and community structure of revegetated tailings following site exploitation. Here, we report the sequencing of 16S rRNA and internal transcribed spacer (ITS) fungal RNA gene amplicons from chlor-alkali residue and from an adjacent undisturbed soil to define the composition and assembly of the rhizosphere microbial communities. After quality filtering, a total of 72,373 and 89,929 bacterial sequences and 122,618 and 111,209 fungal sequences remained fo…
Unraveling biotic interactions determining soil microbial community assembly and functioning
2019
National audience; Microbial communities are at the heart of all ecosystems and yet, a sound understanding of the ecological processes governing the assembly of these communities in the environment is missing. To address the role of biotic interactions in assembly and functioning of the soil microbiota, we used a top down manipulation approach based on the removal of various populations in a natural microbial community. Suspensions of the soil microbiota were subjected to various biocidal and filtration treatments before being inoculated into the same sterilized soil. We hypothesized that if biotic interactions are an important shaping force of the microbiota assembly, removal of microbial …
Microbial community composition but not diversity changes along succession in arctic sand dunes
2017
The generality of increasing diversity of fungi and bacteria across arctic sand dune succession was tested. Microbial communities were examined by high-throughput sequencing of 16S rRNA genes (bacteria) and internal transcribed spacer (ITS) regions (fungi). We studied four microbial compartments (inside leaf, inside root, rhizosphere and bulk soil) and characterized microbes associated with a single plant species (Deschampsia flexuosa) across two sand dune successional stages (early and late). Bacterial richness increased across succession in bulk soil and leaf endosphere. In contrast, soil fungal richness remained constant while root endosphere fungal richness increased across succession. …