RESUMEN
Pseudomonas strains isolated from oil contaminated soils were screened for biosurfactant production. Three out of eleven Pseudomonas isolates were selected for their high emulsifying activity (E24 value on n-hexadecane ~ 78%). These isolates (E39, E311 and E313) were identified as members of the P. putida group using phenotypical methods and a molecular approach. To identify the chemical nature of produced biosurfactants, thin layer chromatography and MALDI-ToF mass spectrometry analysis were carried out and revealed lipopeptides belonging to the syringafactin family. The activity of the produced biosurfactants was stable over a pH range of 6-12, at high salinity (10%) and after heating at 80 °C. Tests in contaminated sand micro-bioreactors showed that the three strains were able to degrade diesel. These results suggest the potential of these syringafactin producing strains for application in hydrocarbon bioremediation.