Search results for "Gradation"
showing 10 items of 1275 documents
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…
Biodechlord : à la recherche de traces de dégradation microbienne du chlordécone dans les sols contaminés des Antilles
2014
Session 5 - Milieux impactés / Impacted mediaSession 5 - Milieux impactés / Impacted media; Objectives: Chlordecone was intensively used in the French West Indies (FWI) to control the banana weewil. Recent surveys showed that arable soils cropped with banana, representing up to 20,000 ha, are contaminated this insecticide with concentrations ranging between 0.2 and 37.4 mg kg−1. Chlordecone was classified as a persistent organic pollutant in May 2009. It is not only contaminating soil resources but also water resources where it is often detected. This insecticide is bioaccumulated in different plant and animals thereby contaminating the food chain causing an important human health. This con…
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…
Transcriptomic and proteomic responses of Microbacterium sp. C448 exposed to sulfamethazine antibiotic
2022
International audience; The Microbacterium sp. C448 was isolated from a soil regularly exposed to sulfamethazine(SMZ), for its ability to partly mineralise this antibiotic and other related sulfonamides.The aim of our study was to explore its metabolic adaptation towards exposure to SMZenvironmental (10 mg/L) and medicinal (250 mg/L) concentrations. Its transcriptomic andproteomic responses were analysed by focusing on the degradation regulon (sad genes) andresistance genes (folP and sul1).The transcriptomic and proteomic results were essentially congruent whatever theconcentrations tested. In culture conditions, exposure to the highest concentration of SMZ led tothe highest sad expression …
Evidence of atrazine mineralization in a soil from the Nile Delta: Isolation of Arthrobacter sp. TES6, an atrazine-degrading strain
2011
International audience; The s-triazine herbicide atrazine was rapidly mineralized (i.e., about 60% of C-14-ring-labelled atrazine released as (CO2)-C-14 within 21 days) by an agricultural soil from the Nile Delta (Egypt) that had been cropped with corn and periodically treated with this herbicide. Seven strains able to degrade atrazine were isolated by enrichment cultures of this soil. DNA fingerprint and phylogenetic studies based on 165 rRNA analysis showed that the seven strains were identical and belonged to the phylogeny of the genus Arthrobacter (99% similarity with Arthrobacter sp. AD38, EU710554). One strain, designated Arthrobacter sp. strain TES6, degraded atrazine and mineralized…
Photocatalytic oxidation of acetonitrile in gas–solid and liquid–solid regimes
2005
Il programma NON mi ha consentito di scaricare il PDF di questo articolo. Se lo volete ditemi come inviarlo ABSTRACT Photocatalytic degradation of acetonitrile was carried out in both gas–solid and liquid–solid regimes using two commercial TiO2 catalysts (Merck and Degussa P25). For the gas–solid regime, a continuous annular photoreactor was used. The influence on photodegradation kinetics of the gas flow rate and concentrations of acetonitrile, oxygen, and water was investigated. Acetonitrile degradation products detected in the gas phase included carbon dioxide and hydrogen cyanide. The same photoactivity was exhibited in the presence and in the absence of water vapour. The liquid–solid reg…
Pull-off adhesion of hybrid glass-steel adhesive joints in salt fog environment
2016
The aim of this paper was to evaluate the durability behaviour of glass/steel adhesive joints exposed to salt fog environmental conditions for ten weeks, according to ASTM B117 standard. To this scope, pull-off mechanical tests were carried out in order to evaluate the performances evolution and damage phenomena of the adhesive joints during the ageing exposition. Two different types of adhesives were compared (i.e. epoxy and polyurethane ones). Moreover, the effects of the glass surface condition and the presence of a basalt mat layer within the adhesive thickness were evaluated. The mechanical performances were related with the occurred failure mechanisms. Epoxy-based joints showed higher…
Exploring long chain n-alkane metabolism in Gordonia sp. strain SoCg
2009
Many microorganisms are able to degrade aliphatic hydrocarbons and a relationship between n-alkane utilization and storage compound synthesis has been described in bacteria. The Gram positive GC-rich n-alkane degrader Gordonia sp. strain SoCg, isolated from a long-term accidentally contaminated beach in Sicily, is able to grow on long n-alkanes up to. It carries a single copy of the alkane hydroxylase gene alkB on its chromosome and its alk cluster revealed a genomic organization similar to other alk clusters of alkane-degrading Gram positive bacteria. The alk gene expression, analysed by Real-time RT-PCR, is induced by n-hexadecane and n-triacontane and coupled to alkane consumption. Inter…
Biostimulant Potential of Humic Acids Extracted From an Amendment Obtained via Combination of Olive Mill Wastewaters (OMW) and a Pre-treated Organic …
2018
Olive mill wastewaters (OMW) detain contain significant levels of phenolic compounds with antimicrobial/phytotoxic activity and high amounts of undecomposed organic matter that may a high pollutant load that exerts negative effects on soil biology because of significant levels in phenolic compounds with antimicrobial/phytotoxic activity and limited biodegradability, and high amounts of undecomposed organic matter. Among OMW detoxification techniques, those focusing on oxidative degradation of phenolic compounds are relevant those focusing on oxidative degradation of phenolic compounds to reduce their toxicity. The composting (bio-oxidation) process in particular, exploits exothermic oxidati…
Photodegradation of Brilliant Green Dye by a Zinc bioMOF and Crystallographic Visualization of Resulting CO2
2021
We present a novel bio-friendly water-stable Zn-based MOF (1), derived from the natural amino acid L-serine, which was able to efficiently photodegrade water solutions of brilliant green dye in only 120 min. The total degradation was followed by UV-Vis spectroscopy and further confirmed by single-crystal X-ray crystallography, revealing the presence of CO2 within its channels. Reusability studies further demonstrate the structural and performance robustness of 1.