Search results for "bacterial communities"

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

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…

1,2-DICHLOROETHANE CONTAMINATED AQUIFER: MICROBIAL COMMUNITY RESPONSE TO BIOSTIMULATION IN MICROCOSM

2022

Validation and application of a PCR primer set to quantify fungal communities in the soil environment by real-time quantitative PCR

2011

Fungi constitute an important group in soil biological diversity and functioning. However, characterization and knowledge of fungal communities is hampered because few primer sets are available to quantify fungal abundance by real-time quantitative PCR (real-time Q-PCR). The aim in this study was to quantify fungal abundance in soils by incorporating, into a real-time Q-PCR using the SYBRGreen (R) method, a primer set already used to study the genetic structure of soil fungal communities. To satisfy the real-time Q-PCR requirements to enhance the accuracy and reproducibility of the detection technique, this study focused on the 18S rRNA gene conserved regions. These regions are little affec…

Microbiology meets geochemistry: geothermal flux shapes different microbial communities at the same exhalative area

2015

Volcanic/geothermal areas are sites of complex interactions between geosphere and biosphere. Pantelleria island (Southern Mediterranean Sea) hosts a high enthalpy geothermal system characterized by high CH4 and low H2S fluxes. Two sites, FAV1 and FAV2, located a few meters apart at the main exhalative area of the island (Favara Grande), recorded similar physical conditions (soil temperature 60°C, soil gas composition enriched in CH4, H2 and CO2). However, while high methanotrophic activity (59.2 nmol g-1 h-1) and high diversity of methanotrophs was detected at FAV2, FAV1 was not active and appeared deprived of methanotrophs (1). Our aim was to investigate the main factors influencing methan…