Structural characterization of the hydrocarbon degrading bacteria-oil interface: implications for bioremediation

Hydrocarbon degrading bacteria, enriched from an in situ bioremediation sit e in Long Valley, AZ emulsified and colonized the surface of waste engine o il. The application of a partial dehydration conventional embedding protoco l for ultrathin-section transmission electron microscopy preserved the hydr ocarbon degrading bacteria-surfactant-oil interface. Bacterial adsorption t o oil occurred in association with a highly charged, amphipathic bacterial surfactant interface (25-50 nm thick). This biosurfactant completely encaps ulated the emulsified oil droplets demonstrating that less than 1% surfacta nt (by volume) is required to emulsify waste hydrocarbon during or to promo te biodegradation. Growth on oil appeared to occur by the uptake of tens of run-sized droplets of emulsified oil. (C) 2001 Elsevier Science Ltd. All r ights reserved.