EVALUATION IN SITU DE LA TOXICITE DUE AUX POLLUANTS METALLIQUES A L’AIDE D’UN BIOTEST BASE SUR L’UTILISATION DES BACTERIES IMMOBILISEES SUR UN SUPPORT SOLIDE

In order to evaluate in situ the heavy metal toxicity, research was undertaken to develop and validate the MetSTICK bioassay based on the inhibition of the activity of the -galactosidase of E. coli immobilized on a solid support specifically by heavy metals. The results showed that MetSTICK operates at a wide range of pH (4-10). The bioassay presented a high sensitivity to Hg (Minimal Inhibitory Concentration: CMI = 0.05 mg L-1), Cu (CMI = 0.3 mg L-1) and to Cd (CMI = 0.1 mg L-1) and sensitivity as the same order as the bioassay MetPAD for Zn (CMI = 0.5 mg L-1). However, MetSTICK was low sensitive for Ni (13 Keywords Olive oil mill wastewater --- Groundwater --- Sediment --- Soils --- metallic pollutants --- MetPAD --- Immobilized bacteria --- MetSTICK