Properties of a biosurfactant produced by the fuel contaminant Ochrobactrum anthropii

A bacterium Ochrobactrum anthropii isolated from contaminated fuel had a strong ability, associated with a cell-bound component, to emulsify hydrocarbon: water mixtures. This was only released into the medium following extraction involving sonication and ultracentrifugation. The component was partially purified using a fast protein liquid chromatography system. From this and polyacrylamide gel electrophoresis, it was found to be essentially a protein of molecular weight 1·04 × 10⁵. Enzyme digests of the crude extract prepared using protease revealed that a protein component was essential for activity. The emulsifying ability of the crude extract was assessed against a variety of hydrocarbon: water systems utilising aliphatic, aromatic and cyclic hydrocarbon. A broad range of hydrocarbons was emulsified.