EFFET DE LA POLLUTION PAR LES METAUX LOURDS SUR LA FLORE BACTERIENNE D’UN SOL AGRICOLE

Abstract

The total microbial flora of agricultural soil (Mostaganem area) grown in the laboratory showed some tolerance to heavy metals. The minimum concentration of inhibition (MIC) by lead was determined. The revealed MIC was located at the lowest concentrations (between 5 and 20mg / L in Pb2+). The flora contaminated by lead has been subjected to the action of antibiotics: Kanamycine et Nitroxoline. The response to these is evidenced by measuring the zone of inhibition. Variation in the size of this area has shown that metallic stress influences the response to antibiotics. Microbial species that seem to be resistant to the presence of lead are then isolated for identification. The establishment of an antibiogram for these species gave zones of inhibition allowing us to foresee a change in the structure of these bacterial species.
These results will allow us to propose an effective method for the remediation or the bioremediation of soils contaminated by heavy metals, and this by isolating the most tolerant or the most resistant species .