Development of Biosurfactants from Indigenous Hydrocarbon-Degrading Bacteria for Enhancing Remediation of Weathered Oily-Soils and Oil Recovery in Qatar

Abstract

Bacterial strains were isolated from highly weathered oil-contaminated sites, identified, and differentiated based on their gene expression with the use of matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI TOF MS). They were clustered using principle component analysis (PCA). PCA and proteodendrogram showed high diversity within same subspecies. This is reflected in the emulsification activity (EA) and solubilization activity (SA) of their adapted biosurfactants. PCA allowed a further clustering of the biosurfactants based on FTIR spectra. Vegetative oils were utilized as carbon source for Bacillus and Pseudomonas strains, showing strong effect on bioemulsifiers production. Moreover, using seven selected strains of Bacillus, high toxicity by hydrocarbons and/or carbon catabolite repression (CCR) was showed. Similarly, bioemulsifiers production by several strains was shown regulated by CCR. These findings showed a type of adaptation occurring with hydrocarbons-degrading bacteria, related to the bacterial cell composition maintaining the biosurfactants composition