Search results for "Dégradation"

Ecology of pesticide-degrading microbes: from agricultural field to microbial gene dynamics

2012

Ecotoxicological impact of low dose herbicide nicosulfuron on soil microbial biodiversity and functioning

2012

Dispersal potential of antibiotrophy along the manure-soil-sediment continuum of sulfamethazine-contaminated agrosystems

2021

An emerging function in the scientific literature, antibiotrophy is the bacterial capacity to metabolize antibiotics. Considered a bioremediation tool, it remains a health risk due to its association with antibiotic resistance. The first goal of this thesis was to study its dispersion within agrosystems contaminated with antibiotics during two coalescence events, i.e. manure spreading on the soil and its erosion towards the aquatic compartment. Experiments have shown the systematic invasion of the soil and sediment bacterial communities by the antibiotroph Microbacterium sp. C448 when sulfamethazine is present but not necessarily mineralized. The antibiotic would have a double function towa…

Utilisation du potentiel de biodégradation de sédiments de rivière comme indicateur d’une diminution du niveau d’exposition a l’herbicide diuron suit…

2013

National audience; Les communautés microbiennes présentent une forte capacité à répondre rapidement à des changements environnementaux et à s’y adapter de manière transitoire ou irréversible. En cas d’exposition chronique à des polluants organiques, les processus d’adaptation microbienne peuvent ainsi conduire à l’amélioration des capacités de biodégradation de ces composés. Cette fonctionnalité concerne principalement les microorganismes hétérotrophes (essentiellement les bactéries et les champignons) capables de dégrader les polluants (totalement ou partiellement) pour les utiliser comme une source d’énergie et de nutriments pour leur croissance. Plusieurs études réalisées en milieu terre…

Diversité et dynamique des communautés microbiennes impliquées dans la dégradation des résidus de culture : influence du type de résidu et des pratiq…

2007

National audience

Genome degeneration and adaptation in a nascent stage of symbiosis

2014

Symbiotic associations between animals and microbes are ubiquitous in nature, with an estimated 15% of all insect species harboring intracellular bacterial symbionts. Most bacterial symbionts share many genomic features including small genomes, nucleotide composition bias, high coding density, and a paucity of mobile DNA, consistent with long-term host association. In this study, we focus on the early stages of genome degeneration in a recently derived insect-bacterial mutualistic intracellular association. We present the complete genome sequence and annotation of Sitophilus oryzae primary endosymbiont (SOPE). We also present the finished genome sequence and annotation of strain HS, a close…

Evolution des paysages Sahélines au cours des six dernières décennies dans la région de Niamey : de la disparition de la brousse tigrée à l'encroutem…

2010

In the Sahel, the rapid increase of the population during the last decades and the climate variation lead to an important environmental degradation. This work aims to measure the impacts of the human pressure on ecosystem during the six last decades. A diachronic cartography of a 100 km² area close to Niamey was done with aerial photographs (1950 and 1975) and GPS measurements (2009). Results showed that the tiger bush vegetation was completely cleared between 1950 and 2009 while the fallow decreases from 7 % to 1 %. In the sandy valley, the increase of cultivated fields from 20,7 % (1950) to 69,4 % (1975) favoured wind and water erosions which allowed surface soil crusting. Between 1975 an…