Search results for "ATRAZINE"

Direct potentiometric immunoelectrodes

1993

TK pencil fine mines type Faber Castell Super polymer from Staedtler are used as graphite based material for an atrazine-sensitive immunoelectrode. Eighteen procedures are tested to immobilize antibodies against atrazine but only one turned out to be useful for the preparation of a graphite based immunoelectrode. It incorporates binding of glutardialdehyde to active sites of the graphite surface and subsequent cross-linking of the antibodies with glutardialdehyde. The method has been carefully optimized with respect to selectivity and the cross-sensitivity is determined for such an electrode based on atrazine-rabbit and atrazine-sheep antibodies as well. Due to the structural difference of …

New developments in immunochemical water analysis down to 30 mul sample volume.

1999

Abstract The determination of trace levels of pesticides like atrazine in water samples of small, restricted volumes is one of the future demands of environmental analysis. In a brief review existing chromatographic and immunochemical methods for atrazine are critically discussed. Then a simple rapid enzyme-linked immunosorbent assay (ELISA) using the tip of an inoculation needle as a solid surface is presented. The sample volume could be reduced to 30 μl. The assay had a centre of the test IC50 of 0.12 μg l−1 and permitted the characterisation of atrazine at levels of 0.022–2.90 μg l−1. A first outlook for automatisation is given. The new method was compared with an ELISA using 96 well mic…

Étude de l’évolution du potentiel génétique de populations bactériennes dégradant l’atrazine

2011

17 pages de références bibliographiques et 20 pages d'annexes; L’atrazine, un des herbicides les plus utilisés pour contrôler le développement des plantes adventices dans les cultures, a conduit à la contamination de l’environnement. L’exposition chronique à cet herbicide a conduit à l’émergence de populations microbiennes du sol capables de dégrader l’atrazine et de l’utiliser comme une source d’azote pour leur croissance. Ces populations microbiennes sont responsables de la biodégradation accélérée (BDA) de l’atrazine, un service écosystémique contribuant à diminuer la persistance de cet herbicide dans l’environnement. L’objectif de ce travail était d’étudier les mécanismes génétiques et …

In vitro evolution of an atrazine-degrading population under cyanuric acid selection pressure: Evidence for the selective loss of a 47kb region on th…

2011

International audience; The adaptation of microorganisms to pesticide biodegradation relies on the recruitment of catabolic genes by horizontal gene transfer and homologous recombination mediated by insertion sequences (IS). This environment-friendly function is maintained in the degrading population but it has a cost which could diminish its fitness. The loss of genes in the course of evolution being a major mechanism of ecological specialization, we mimicked evolution in vitro by sub-culturing the atrazine-degrading Pseudomonas sp. ADP in a liquid medium containing cyanuric acid as the sole source of nitrogen. After 120 generations, a new population evolved, which replaced the original on…

Evaluation of the concept of heterology in a monoclonal antibody-based ELISA utilizing direct hapten linkage to polystyrene microtiter plates.

2005

A series of new heterologous haptens has been synthesized and used as coating haptens in an antigen-immobilized immunoassay with a monoclonal antibody against atrazine. Coating was achieved by covalently linking the different haptens to a glutaraldehyde network directly bound to the polystyrene surface of a standard 96-well microtiter plate. With the assay designed in the antigen-immobilized format with direct chemical linkage of the hapten to the solid polystyrene surface well-defined hapten densities were achieved in all experiments. The results of different experiments with different coating haptens were comparable. Using different heterologous haptens it appears that the concept of hete…

Molecular approaches to study microbial mechanisms involved in pesticide biodegradation: atrazine as a case study

2006

Development of herbicide-resistant varieties of foxtail millet

2012

International audience; Developing herbicide resistance in forsaken small crops could be a way to maintain food and cultivation system diversity, otherwise they would disappear due to the impossibility or cost to control the weeds. It is the case with foxtail millet, Setaria italica, a small grain, preferentially autogamous, C4 cereal. Three different herbicide-resistant materials were developed using wild germplasm resources. They allowed: 1) to better characterize the resistance mechanisms and inheritance; 2) provide plant materials to test the efficiency of the crop resistance at field level; and 3) experiment on the possible flow back of the resistance gene to the wild relative and amon…

Etude de l'évolution du potentiel génétique de populations bactériennes dégradant l'atrazine

2011

Atrazine, one of the most used herbicide to control the development of weeds in crop, has led to the contamination of the environment. Repeated exposure to this herbicide resulted in the emergence of microbial populations able to degrade atrazine and to use it as a nitrogen source for its growth. These microbial populations are responsible for accelerated biodegradation of atrazine (BDA), a key ecosystemic service diminishing the persistence of this herbicide in the environment. The aim of this PhD work was to study genetic and physiological mechanisms responsible for functioning and improving of this ecosystemic service. We applied an experimental approach starting from genes to communitie…