11 research outputs found
Research Paper Polyclonal antibodies production against Staphylococcus aureus protein A: ELISA technique optimization for milk quality control
The main aim of this project is to produce polyclonal antibodies directed against the Staphylococcus aureus protein A and their use to appreciate bacteriological analysis of milk quality. In this context, an immunization produce was set up to test and detect in a batch of animals the convenient responder to the injected antigen. Furthermore, to optimize all parameters of retained ELISA test, a cross-table was conceived by using various concentrations of different reagents and has allowed selecting the optimaldilutions as follows: 1) 1/1000 for anti-Staphylococcus aureus protein A mouse antibodies and 1/2000 for anti-Staphylococcus aureus protein A rabbit antibodies. 2) 1/4000 for anti-Staphylococcus aureus treated by heat mouse antibodies and 1/500 for anti-Staphylococcus aureus protein A rabbit antibodies. 3) 1/2000 for anti-Staphylococcus aureus treated by NaClO mouse antibodies and 1/500 for anti-Staphylococcus aureus protein A rabbit antibodies. The application of optimized ELISA test to searchand detect Staphylococcus aureus germs in different samples of milk has shown very satisfying results when compared to those obtained by bacteriological method. Indeed, the sensitiveness and the reproducibility, as well as the possibility to analyze a great number of samples in the same time at a reduced manner make the immunochemical method a best choice of test able to replace recent bacteriological methods
Effects of natural and anthropogenic environmental changes on riverine fish assemblages: a framework for ecological assessment of rivers
Direct link between fluoranthene biodegradation and the mobility and sequestration of its residues during aging
International audienceThe aim of this study was to assess the influence of the polycyclic aromatic hydrocarbons (PAH)-degrading activity in the fate of fluoranthene in soils. Three soil samples with different degrading activities (an industrial sod, the same industrial soil after biostimulation, and an agricultural sod) were spiked with C-14-fluoranthene and incubated for 6 mo, with monitoring of biodegradation and mineralization. To follow the distribution C-14-fluoranthene residues (i.e., C-14-fluoranthene and its degradation products) among the soil compartments, we performed successively leaching, centrifiigation (to collect intraaggregate pore water), solvent extraction, and combustion of the soil columns. In the industrial soil, no mineralization of C-14-fluoranthyene was observed, and only 3% of the initial C-14-activity was non-extractable (with acetone:dichloromethane) after 165 d of incubation. The biostimulation (addition of unlabeled polycyclic aromatic hydrocarbons) increased the degrading activity in this soil (59% of 14 C-fluoranthene was mineralized) and increased the residues sequestration (13% of 14 C-activity was non-extractable). The microflora of the agricultural soil mineralized C-14-fluoranthene more slowly and to a lesser extent (25%) than the biostimulated soil, but a higher amount of C-14-activity was sequestered (41 %). Thus, the rate and extent of 14C-fluoranthene mineralization seemed to be related to the C-14-activity sequestration by controlling the accumulation of degradation products in the soil. C-14-Fluoranthene biodegradation enhanced the concentration of C-14-polar compounds in the intra-aggregate pore water. Our results point out the close link between fluoranthene biodegradation and two key aging processes, diffusion and sequestration, in soils. biodegradation controls the mobility and sequestration of residues by transforming fluoranthene into more polar molecules that can diffuse into the intra-aggregate pore water and then might become bound to the matrix or entrapped in the microporosity