Search results for "microbial"
showing 10 items of 2041 documents
Predicting pesticide biodegradation potential from microbial community composition: new tools for bioremediation
2022
Bioaugmentation is receiving increasing attention as a green technology to treat contaminatedareas by inoculating specific biodegrading microorganisms. However, our understanding of therole of microbial community composition and structure in the expression of contaminantdegradation potential is yet to improve. It could help making wise choice for microorganisms –community or specific strain – to be inoculated in contaminated soils with consideration to theirindigeneous microbiota.Here we tried to predict the microbial degradation of two herbicides, glyphosate andisoproturon by means of penalized regression and machine learning methods routinely used ingenomic selection. To this end, we cond…
Different Medicago truncatula genotypes, expressing different phenotypes, modulate microbial functional genes in the rhizosphere
2022
Plants host in their rhizosphere a remarkable diversity of microorganisms that in return promote plant growth and health. Thus, the plant microbiota emerges as a novel component that expand the capacity of plants to adapt to the environment, and thus pave the way for future breeding approaches.It is widely known that different plant species harbor different microbiota, but very few studies showed an impact of the plant genotypes on the microbiota. These contrasting results may depend on the choice of the tested genotypes.We formulate the hypothesis that only those plant genotypes showing high genetic diversity and expressing different phenotypes harbor different rhizosphere microbiota and a…
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…
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…
Exposure of benthic microbial communities to pharmaceuticals and resulting adaptation including tolerance, biodegradation and antibiotic resistance: …
2022
International audience; Since the early 1920’s, pharmaceuticals, including antibiotics, have been massively producedand consumed for the benefit of both human and animal health. Pharmaceuticals residues havethen reached the aquatic environment through diffuse and point (wastewater) sources. Amongthe pharmaceutical residues, the ubiquitous presence of antibiotics could exert a selectivepressure on microbial communities leading to the acquisition and dissemination of antibioticresistance in the environment.We present here the synthesis of recent research projects (e.g. PANDORE, Antibio-tools,Antibiotox, PharmaTox...) investigating the dissemination of pharmaceuticals, includingantibiotics, in…
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, …
Study and modelling of the impacts of agricultural practices on the abundance of soil microbial communities: dynamics at the landscape scale
2022
Soil Microbial communities play a major role in soil fertility and are important as bioindicators to evaluate the impacts of agricultural practices on soils. The challenge is to promote their use in order to support / accelerate innovation in the agricultural sector. The goal of this thesis was to characterize spatial and temporal dynamics of soil microbialcommunities at the scale of an agricultural landscape in order to create models and propose a Decision Support Instrument (DSI) for stakeholders in the agricultural communities. For this, a multi-disciplinary approach was used combining microbial ecology, environment assessment, spatial computer modeling, associated to a participatory app…
Effects of hydrostatic pressure on yeasts isolated from deep-sea hydrothermal vents
2015
International audience; Hydrostatic pressure plays a significant role in the distribution of life in the biosphere. Knowledge of deep-sea piezotolerant and (hyper)piezophilic bacteria and archaea diversity has been well documented, along with their specific adaptations to cope with high hydrostatic pressure (HHP). Recent investigations of deep-sea microbial community compositions have shown unexpected micro-eukaryotic communities, mainly dominated by fungi. Molecular methods such as next-generation sequencing have been used for SSU rRNA gene sequencing to reveal fungal taxa. Currently, a difficult but fascinating challenge for marine mycologists is to create deep-sea marine fungus culture c…
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…
Impact of a new bio-pesticide produced by Paenibacillus sp. strain B2 on the genetic structure and density of soil bacterial communities
2007
The effect of paenimyxin, a new biopesticide produced by Paenibacillus sp. strain B2, on the density of soil bacterial communities was assessed by colony counting and by 16S rDNA and nirK quantitative polymerase chain reaction (PCR). Paenimyxin had a negative effect on the bacterial colony-forming unit (CFU) number, which was significantly reduced 2 and 4 days after treatment. The effect of paenimyxin on cultivatable bacteria was negligible 7 days after treatment. Approximately 107 16S rDNA sequences per gram of soil (dry weight) were detected by quantitative PCR in all samples. Paenimyxin did not affect the quantification of 16S rDNA or of the denitrifying bacterial community. In addition,…