Search results for "Bacterial Communitie"
showing 10 items of 25 documents
Copper Dynamics and Impact on Microbial Communities in Soils of Variable Organic Status
2008
International audience; The effect of soil organic status on copper impact was investigated by means of a microcosm study carried out on a vineyard soil that had been amended with varying types of organic matter during a previous long-term field experiment. Soil microcosms were contaminated at 250 mg Cu kg−1 and incubated for 35 days. Copper distribution and dynamics were assessed in the solid matrix by a sequential extraction procedure and in the soil solution by measuring total and free exchangeable copper concentrations. Copper bioavailability was also measured with a whole-cell biosensor. Modifications of microbial communities were assessed by means of biomass-C measurements and charact…
Combining ecophysiological and microbial ecological approaches to assess interaction between genotypes of Medicago truncatula and the soil bacterial …
2011
International audience; Microbial communities can play a key role in sustainable agriculture by improving crop growth. Currently, a major stake is to study the effect of the plant genotype on the shaping of the soil microbial communities in relation to the plant nutrition. Methods: The links between the plant genotype and the rhizospheric bacterial communities were assessed at both structural and functional level using a multidisciplinary approach. On the one side, the genetic structure (Automated Ribosomial Intergenic Spacer Analysis (ARISA)) and diversity (454 pyrosequencing) of bacterial communities of the rhizosphere was first analysed. On the other side, using an ecophysiological model…
Biogeographical patterns of soil bacterial communities.
2009
International audience; This study provides the first maps of variations in bacterial community structure on a broad scale based on genotyping of DNA extracts from 593 soils from four different regions of France (North, Brittany, South-East and Landes). Soils were obtained from the soil library of RMQS (Réseau de Mesures de la Qualité des Sols = French soil quality monitoring network). The relevance of a biogeographic approach for studying bacterial communities was demonstrated by the great variability in community structure and specific geographical patterns within and between the four regions. The data indicated that the distribution of bacterial community composition might be more relate…
Biogeography of soil microbial communities: a review and a description of the ongoing french national initiative
2010
International audience; Microbial biogeography is the study of the distribution of microbial diversity on large scales of space and time. This science aims at understanding biodiversity regulation and its link with ecosystem biological functioning, goods and services such as maintenance of productivity, of soil and atmospheric quality, and of soil health. Although the initial concept dates from the early 20th century (Beijerinck (1913) De infusies en de ontdekking der backterien, in: Jaarboek van de Knoniklijke Akademie van Wetenschappen, Muller, Amsterdam), only recently have an increasing number of studies have investigated the biogeographical patterns of soil microbial diversity. A such …
Evolution of genetic degradation potential of pesticide-degrading bacterial communities
2009
International audience
Translation of metagenomics agroecosystems in ecological services
2011
National audience
Do tropical soil engineer stimulate the bacterial communities link to N2O emission?
2009
National audience
Development of a new functional marker for β-triketone herbicides exposure in agricultural soils
2018
The β-triketone herbicides are maize selective herbicides that have been largely applied in replacement of atrazine, banned in Europe in 2003. Their mode of action lays on the inhibition of the p-hydroxyphenylpyruvate dioxygenase (HPPD), a key enzyme of the carotenoid biosynthesis. In recent studies, we showed that within the soil bacterial community, many microorganisms possess a functional HPPD enzyme involved in tyrosine metabolism. These “non-target organisms” harbor the target of the β-triketone herbicides and consequently may be affected in response to its exposure. Within this context, the objective of our work is to check for the interest of hppd bacterial community as a marker of e…
Response of soil bacterial and hppd communities to tembotrione herbicide
2022
Herbicides used in agriculture aim to prevent weed growth but are known to end up in contactwith soil microorganisms, thus defined as non-target organisms. Tembotrione, a recentlymarketed β-triketone herbicide, is known to inhibit the 4-HydroxyPhenylPyruvateDioxygenase(4-HPPD) in weeds. This enzyme is also found in numerous soil microorganisms, such as somePGPR and symbiotic bacteria, that play a key role in maintenance of ecosystem services.In this study, one of the major concerns is to assess whether tembotrione could have toxiceffects on soil microorganisms and could disturb soil microbial community dynamic andstructure. To investigate the possible impacts of this herbicide on these comm…