Dégradation des hydrocarbures par les biosurfactants bactériens : une approche durable pour la dépollution pétrolière

Abstract

This work aims to evaluate the potential of production of biosurfactants in bacterial strains for their application in the biodegradation of hydrophobic compounds. A total of 45 isolates, belonging to the genera Bacillus and Pseudomonas, from arid soils, were subjected to phenotypic screening in order to evaluate their hemolytic, lipolytic and lipopeptide activities. Complementary functional tests were performed to measure the emulsification index (E24%), oil dispersion capacity, as well as metabolic activity in the presence of various hydrophobic substrates. Among the strains tested, Bacillus subtilis D7 and Acinetobacter sp. MN6 proved to be the most efficient and were selected for crude oil biodegradation tests and evaluation of phytotoxicity of degradation products. These two strains showed high metabolic activity, increased oil dispersal capacity and a visible reduction in the oil phase. Phytotoxicity tests showed a significant decrease in the toxicity of degraded oil, although a residual effect on root and leaf growth of seedlings was observed. These results suggest that the strains studied, in particular MN6, have a strong potential for applications in bioremediation of hydrocarbons and sustainable agricultural valorization