Abstract
The production and properties of the biosurfactant synthesized by
Bacillus subtilis
CCTCC AB93108 were studied. The maximum concentration of the surfactant is 1.64 g/L when the bacteria grow in a medium supplemented with glucose as carbon sources. The isolated biosurfactant is a complex of protein and polysaccharide without lipids. It reduces the surface tension of distilled water to 45.9 mN/m, and its critical micelle concentration (CMC) is 2.96 g/L. It can stabilize emulsions of several aromatic and aliphatic hydrocarbons, such as benzene, xylene,
n
-pentane,
n
-nonane, gasoline and diesel oil. It presents high emulsification activity and stability in a wide range of temperature (4–100°C) and a long period of duration.