Biosurfactant emulsan

Similarly, bioemulsifiers, such as emulsan produced by Acinetobacter calcoaceticus, have been shown to aid in removal of metals. Potential for remediation of soils using bacterial exopolymers is indicated by a study which showed that purified exopolymers from 13 bacterial isolates removed cadmium and lead from an aquifer sand with efficiencies ranging from 12 to 91% (Chen et al., 1995). Although such molecules have much larger molecular weights ( 106) than biosurfactants, this study showed that sorption by the aquifer sand was low, suggesting that in a porous medium with a sufficiently. large mean pore size, use of exopolymers may be feasible. 

Some enzymatically prepared glycolipids and polymeric biosurfactants, such as trehalolipids and emulsan [31b, 526], as well as acylated proteins (see Section 5) are mainly of nonoinic nature. 

Biobased surfactants are typically divided into glycolipids, lipopeptides, phospholipids, functionalized fatty acids, and polymeric biosurfactants. Typical representatives of these groups are rhamnoUpids, trehaloselipids, sophoroselipids, cellobioselipids, surfactin, liposan, and emulsan. 

Biosurfactants have been tested in enhanced oil recovery and the transportation of crude oils [10], They were demonstrated to be effective in the reduction of the interfacial tension of oil and water in situ, the viscosity of the OH, the removal of water from the emulsions prior to processing and in the release of bitumen from tar sands. The high molecular weight Emulsan has been commercialized for this purpose [11]. It contains a polysaccharide with fatty acids and proteins attached. Other high-molecular weight biosurfactants are reviewed by Ron and Rosenberg [12]. 

In contrary to the other surface active molecules, polymeric biosurfactants are high-molecular weight compounds and generally exhibit high emulsifying activity. Among current polymeric biosurfactants, a more potent one is emulsan. 

Bacillus subtilis produces lipopeptide biosurfactant called surfactin which has excellent surface activity. Unlike other biosurfactants, surfactin is highly hydrophilic and forms transparent gel which can be exploited in skin care formulation. Emul-san, a high-molecular weight biosurfactant produced by Acinetobacter calcoaceticus, exhibits high emulsifying activity. Emulsan can be used in soaps and shampoos... 

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