Search results for " Community"

Lien entre la diversité microbienne, la stabilité des communautés microbiennes et le turnover des matières organiques du sol

2014

Soil microbial communities act as important agents of the biological soil functioning, particularly through their involvements in the transformations of biogeochemical cycles (C, N, P…). In agro-ecosystems, the diversity of these communities is affected by perturbations associated to agricultural practices, and the significance of these modifications in terms of preservation of biological functioning and sustainability of agricultural systems has emerged as a central issue in the environmental sciences. Whereas the role of biodiversity has been well studied for macroorganisms, in particular for plants; the biodiversity/activity relationship is still largely unknown for soil microorganisms. …

Impact of fertilization and direct seeding on activity and abundance of key denitrifier communities in a tropical soil

2007

Affiche, résumé; The aim of this work was to investigate to which extent different practices impacted on the bacterial communities involved in N2O emission.

Soil fungal communities ecology: a biogeographical approach

2011

Affiche, résumé; International audience

Promenade among terrestrial denitrifiers: from genetics to ecology

2011

Use of PCAH as a molecular marker for estimating the diversity of the protocatechuate-degrading bacterial community in soil environment

2007

Microorganisms degrading phenolic compounds play an important role in soil carbon cycling. The pcaH gene encoding a key ring-cleaving enzyme of the β -ketoadipate pathway was selected as a functional marker. Using a degenerate primer pair, pcaH fragments were cloned from two soils. The RFLP screening of 150 pcaH clones yielded 68 RFLP families. Comparison of 86 deduced amino acid sequences displayed 70 % identity to known PcaH sequences. Phylogenetic analysis results in two major groups mainly related to PcaH sequences from Actinobacteria and Proteobacteria phyla. This gene constitutes a suitable molecular marker to study the diversity of this functional group.

Spatial processes driving soil microbial community assembly on a wide scale

2012

International audience; Soil houses a huge biodiversity involved in ecological services through microbial community assembly. However, processes driving soil microbial community assembly are still scarcely understood, particularly the relative importance of environmental heterogeneity regarding to dispersal limitations. This can be achieved through studying the determinism of taxa-area relationship (TAR, how community composition change with geographic distance), a fundamental relationship in ecology. Here, a biogeographical approach was applied on a wide scale to evaluate TAR for soil bacterial and fungal communities and to partition their spatial variations into environmental heterogeneit…

Is soil fauna an important driver of the structure and activities of denitrifier communities in tropical soils?

2007

International audience

Insights into the unexplored diversity of the nitrous oxide reducing microbial community

2012

Nitrous oxide (N2O) is a major radiative forcing and stratospheric ozone depleting gas emitted from terrestrial and aquatic ecosystems. It can be transformed to N2 by bacteria and archaea harboring the nitrous oxide reductase (N2OR), which is the only known N2O sink in the biosphere. Despite its crucial role in mitigating N2O emissions, knowledge of the N2OR in the environment remains limited. Here, we report a comprehensive phylogenetic analysis of the nosZ gene coding the N2OR in genomes retrieved from public databases. The resulting phylogeny revealed two distinct clades of nosZ, with one unaccounted for in studies investigating N2O reducing communities. Examination of N2OR structural el…

Microbial-biogeography at the scale of France by the use of molecular tools applied to the French soil quality monitoring network (RMQS)

2009

International audience

ECOFUN-MICROBIODIV : an FP7 European project to estimate the ecotoxicological impact of low dose pesticide application in agriculture on soil functio…

2013

Soil is hosting a tremendous microbial diversity playing a key-role in a number of soil ecosystemic services including nutrient cycling and filtering. ln the European Soil Framework Directive pesticides are clearly marked as one of the major threats for soil biodiversity and functioning. ln orcier to guarantee minimum effects of pesticide application on soil microbes, pesticicleregistration at EU level (Regulation 2006/388) consiclers the toxicity of pesticides ontci non targefsoil microbes by relying on carbon- and nitrcigen-mineralization tests (OECO 216, 217). However tnese tests do not provicle a comprehensive assessment of pesticides onto soil microbes.-ECOFUN-MICROBIODIV was a project…