Isolement et identification des bactéries marines ayant un potentiel de biodépollution des déchets

Abstract

Petroleum hydrocarbons are very harmful organic pollutants and pose a major risk to the environment and therefore to human and animal health. The biological depollution of these sites requires microorganisms that are effective in this biological process. Hydrocarbonoclastic bacteria are microorganisms that typically feed on hydrocarbons, and can also be good biomolecules producers called biosurfactants with many environmental and industrial applications . As such, the objectives of our work are to isolate and characterize bacterial strains with a potential for hydrocarbon degradation from a sample of seawater and mud located in northwestern Algeria. The cultivation on MSM agar with supplemented crude oil has made it possible to isolate 6 bacterial strains, which differ in their macroscopic and microscopic characters and the results of some biochemical tests. These six isolates are tested for their ability to degrade crude oil, diesel and gasoline pollutants in a liquid MSM medium, by measuring optical density, and also on solid MSM medium by oil displacement method for screening of biosurfactant production. The results of the biodegradation test allow to obtain the 6 strains made the growth in the presence of crude oil, diesel and gasoline, The 6 isolates showed zones of degradation and positive growth, a strain that made a clear zone around the deposit.