ABSTRACT
II. Biosurfactants and the Uptake of Insoluble Liquids 271
III. Biosurfactant Characteristics 273
IV. Biosurfactants and the Hydrocarbon-Aqueous Interface 274
V. The Microbe-Aqueous Interface 274
VI. Interfaces in a Hydrocarbon Fermentation 276
VII. Cell Distribution 280
VIII. Solid Substrates 282
IX. Conclusions 285 References 285
Microbes that degrade hydrophobic, water-insoluble substrates such as hydrocarbon liquids or solids, fats, oils or waxes, or elemental sulfur usually produce surfactant substances or biosurfactants [1]. Insolubility, having a very low saturation concentration in water, limits the available aqueous concentration of these substrates. Surfactant improves the availability of the substrate to the microbial cells by allowing emulsion formation. This expands the interfacial area at the aqueous-substrate interface, increasing the rate of substrate dissolution and thus supporting a greater rate of substrate utilization by the microbial population.
