Abstract
Glycolipid biosurfactants produced by Rhodococcus species HI 3-A were used to enhance polycyclic aromatic hydrocarbon (PAH) solubility into the aqueous phase and promote bioavailability for degradation. This work builds on an ongoing initiative to evaluate the performance of biosurfactants in the remediation of petroleum hydrocarbons in contaminated aqueous and sediment environments. The initial stage of the research involved the production and characterization of the extracellular biosurfactants produced byHI3-A when grown on hexadecane. The final stage evaluated the performance of the glycolipid biosurfactant as compared to an unamended aqueous phase and a common chemical surfactant (Tween 80) in enhancing the partitioning of weathered West Texas Crude Oil PAHs into the aqueous phase. Gas chromatographic/mass spectrophotometric (GC/MS) analysis of the water soluble fraction (WSF) was used to determine the degree of PAH partitioning. The acute toxicity of the petroleum PAHs partitioned into the aqueous phase in the presence and absence of surfactants was determined using the Mcrotox' Basic Test. Results showed that the toxicity of the PAHs partitioned into the aqueous phase with the amended biosurfactant was greater than the toxicity of the PAHs partitioned into the aqueous phase without surfactants. The toxicity of the PAHs partitioned into the aqueous phases amended with the biosurfactant and chemical surfactant were not significantly different from each other. The increased toxicity of the aqueous phases with the surfactants is attributed to the increased partitioning of the weathered crude's PAHs into the aqueous phase.
Lambert, Beatrice Lorraine (1995). Aqueous phase toxicity of West Texas crude oil as influenced by the Rhodococcus H13-A biosurfactant. Master's thesis, Texas A&M University. Available electronically from
https : / /hdl .handle .net /1969 .1 /ETD -TAMU -1995 -THESIS -L362.