The capacities of a biosurfactant producing and polycyclic aromatic hydrocarbon (PAH) utilizing bacterium, namely, strain 1C, isolated from an Algerian contaminated soil, were investigated. Strain 1C belonged to the Paenibacillus genus and was closely related to the specie Paenibacillus popilliae, with 16S rRNA gene sequence similarity of 98.4 %. It was able to produce biosurfactant using olive oil as substrate. The biosurfactant production was shown by surface tension (32.6 mN/m) after 24 h of incubation at 45 °C and 150 rpm. The biosurfactant(s) retained its properties during exposure to elevated temperatures (70 °C), relatively high salinity (20 % NaCl), and a wide range of pH values (2-10). The infrared spectroscopy (FTIR) revealed that its chemical structure belonged to lipopeptide class. The critical micelle concentration (CMC) of this biosurfactant was about 0.5 g/l with 29.4 mN/m. In addition, the surface active compound(s) produced by strain 1C enhanced PAH solubility and showed a significant antimicrobial activity against pathogens. In addition to its biosurfactant production, strain 1C was shown to be able to utilize PAHs as the sole carbon and energy sources. Strain 1C as hydrocarbonoclastic bacteria and its interesting surface active agent may be used for cleaning the environments polluted with polyaromatic hydrocarbons.

The aim of this work was to evaluate the effect of different surfactant type on biodegradation of low molecular weight polycyclic aromatic hydrocarbons (PAHs) (naphthalene and anthracene) in aqueous media by bacterial strain isolated from crude oil-contaminated soil in southern of Algeria. The biodegradative ability of the strain tested was determined by measuring OD 600 and the residual PAH concentration by UV-Vis and GC. The results indicated that 1C strain could degrade both naphthalene and anthracene without addition of surfactants; the degradation rate of PAHs was decreased when surfactants were added. The higher bacterial growth observed in the presence of Tween 80 could be due to the fact that this surfactant can be used as an additional carbon source by 1C strain.

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