SURFACTANT-ENHANCED BIOREMEDIATION

This study was undertaken to examine the effect of three structurally related, non-ionic surfactants, Triton X-45, Triton X-100 and Triton X -165, as well as the oleophilic fertilizer, Inipol EAP 22, on the rate of biodegradation of phenanthrene by pure bacterial cultures. Each su rfactant dramatically increased the apparent aqueous solubility of phe nanthrene. Model studies were conducted to investigate the ability of these surfactants to enhance the rate of transport and uptake of polyc yclic aromatic hydrocarbons into bacterial cells, and to assess the im pact that increasing the aqueous solubility of hydrocarbons has on the ir rate of biodegradation. Our results indicate that increasing the ap parent aqueous solubility of hydrocarbons can lead to enhanced biodegr adation rates by two Pseudomonas saccharophila strains. However, our e xperiments also suggest that some surfactants can inhibit aromatic hyd rocarbon biodegradation by certain bacteria. Our data also support the hypothesis that surface-active components present in the oleophilic f ertilizer formulation, Inipol EAP 22, may have significantly contribut ed to the positive results reported in tests of remedial agent impact on bioremediation, which was used as a supplemental clean-up technolog y on Exxon Valdez crude oil-contaminated Alaskan beaches.