SCREENING OF HEAVY METALS AND AROMATIC HYDROCARBON-RESISTANT BACTERIA ISOLATED FROM MARCHICA LAGOON ECOSYSTEM IN MOROCCO

The lagoon of Marchica, which is classified as a sensitive biological area has been, in the past, a major destination for metal and hydrocarbons pollutants. Consequently, all fish resources have become unusable. The pollution of this marine environment has been the subject of major concern, although the site is no longer subjected to active pollution discharges. The aim of the present study was to evaluate metal contamination over fifteen different sampling sites and to isolate heavy metals, antibiotics and hydrocarbon-tolerant bacteria. The isolated strains showed multiple metal resistances to copper, lead, cadmium and mercury at concentrations of, 8, 6.8, 4 and 2 mmol/l, respectively for Exiguobacterium marinum. Furthermore, the bacterial community was able to grow in the presence of significant concentrations of sodium chloride (80 g/l), polycyclic aromatics hydrocarbons (PAHs: at 7.3 g/l), and antibiotics (especially penicillin and tetracyclin, as shown in Table 6). The growth kinetics in the presence of mercury (1 and 2 mmol/l), showed that the isolates had a noticeable ability to multiply in the presence of inhibitors. Taking into consideration the halophilic properties and the substantial resistance in the presence of heavy metals and hydrocarbons, the isolated strains have demonstrated potentially significant contributions as wastewater treatment bacteria, and in the potential implementation of a decontamination protocol through the use of bioremediation strategies to reduce lagoon pollution.