Impact of Biosurfactants, Surfactin, and Rhamnolipid Produced from Bacillus subtilis and Pseudomonas aeruginosa, on the Enhanced Recovery of Crude Oil and Its Comparison with Commercial Surfactants

Abstract

The continuous production of crude oil over the past several years has matured numerous oil reservoirs worldwide. The current study aims to increase the recovery of low-waxy-crude oil using biosurfactants produced by microorganisms. Ex situ biosurfactant-induced microbial-enhanced oil recovery (MEOR) is addressed in this work, and the substantial findings will be useful to predict its performance in reservoirs. Experiments were carried out to investigate the performance of MEOR in porous media using synthetic surfactants and biosurfactants. Mass spectrometry results show that the microorganisms Pseudomonas aeruginosa and Bacillus subtilis produced biosurfactants, such as rhamnolipid and surfactin with molecular weights of 1016 and 355 Da, respectively. The results indicate that higher-oil-recovery efficiency can be achieved using biosurfactants. The concentration of 200 ppm surfactin showed 15.43% of enhancement in oil recovery, whereas 200 ppm rhamnolipid exhibited 15.47% increase in the recovery of oil. However, at the same concentration, cetyltrimethylammonium bromide and sodium dodecyl sulfate enhanced the recovery of crude oil by 7 and 8.82%, respectively. The efficiency of biosurfactants in subsiding the interfacial tension between the crude oil and water system in porous media was observed to be the main cause for improved oil recovery. Enhanced oil recovery even at low concentrations and stability at high salinities, pH values, pressures, and temperatures make surfactin and rhamnolipid excellent candidates as biosurfactants and offer good prospects for their use in MEOR.

Anaerobic Microbial Activity May Affect Development and Sustainability of End-Pit Lakes: A Laboratory Study of Biogeochemical Aspects of Oil Sands Mine Tailings

“…However, in the current study, Smithella was not dominant at 30 °C; rather Pseudomonas and Desulfurisporaceae codominated during active methanogenesis in this FFT (Table S3). We speculate involvement of Pseudomonas in scavenging some hydrocarbon/metabolites as they are reported to be involved in anaerobic biodegradation of hydrocarbons including nitrogen and sulfur heterocycles , and production of biosurfactants in oil reservoirs particularly at in situ temperatures of 36 and 80 °C . This different microbial community structure might explain why relatively less methanogenesis was observed at 30 °C compared to that at 10 and 20 °C; i.e., Pseudomonas spp.…”

Performance Evaluation of Bacterial Consortia from Low-Permeability Reservoir in Ordos Basin

“…The emulsification of the consortium strains was due to the existence of biosurfactants. As amphiphilic molecules, it was soluble in water and oil, resulting in emulsified crude oil on the macrolevel [38,39]. Bacillus has been shown to produce lipopeptide biosurfactants [40,41], and all single strains involved in the combinations have been shown to produce biosurfactants in previous experiments.…”