Production of Biosurfactants by Crude Oil Biodegrading Bacterial Isolates and its Potential on Enhanced Crude Oil Recovery

Abstract

Background The present work attempts to investigate production of biosurfactants, the four bacterial isolates were isolated from mud contaminated soil and formation water. The ability of these bacterial isolates to produce a biosurfactant were detected, Surface properties of the produced biosurfactant were confirmed by determining the emulsification power E24%, surface tension, and the mutants bacteria were tested for viscosity. Methods The expected biosurfactants were tested for antibacterial effect, oil dispersion test, the crude biosurfactant has been extracted from supernatant culture growth, and the yield of crude biosurfactant was evaluated where the chemical structure of the produced biosurfactant was confirmed using FTIR analysis, and microbial enhanced oil recovery (MEOR) was calculated. Results Eighteen bacterial isolates were isolated from formation water samples and mud-contaminated soil, four bacterial isolates were selected after screening for biosurfactants production and testing the optimum biosurfactants production conditions. it was found that the bacterial biosurfactant has the ability to recover more crude oil and the additional oil recovery was found  to be (16.4, 13.7, 21.2 and 22.7) % for Stenotrophomonas  maltophilia (isolate 6) , Alcanivorax dieselolei  (isolate 8)  ,  Pseudomonas aeruginosa(10)  and Staphyllococcus  aureus ( isolate 11) respectively, FTIR test were done to the crude biosurfactants, and the produced chemical groups such as COOH and OH, tell us that the produced biosurfactants are almost rhamnolipid and glycolipids. Conclusion Results demonstrate the ability of bacteria to produce biosurfactants, that enable bacteria to enhance oil recovery, by reducing surface tension and inducing emulsification power.