Purification and characterization of a novel biosurfactant produced by Bacillus licheniformis MS3

The physical properties and chemical structure of a new biosurfactant (licheniformin) produced by Bacillus licheniformis MS3 were investigated. The purified biosurfactant was identified as a lipopeptide with amino acid sequence of Gly, Ala, Val, Asp, Ser, Gly, Tyr and a lactone linkage between the carboxyl group of Aspargine and hydroxyl group of Tyrosine residue. The fatty acid moiety was attached to N-terminal amino acid residue through an amide bond. The purified licheniformin could lower the surface tension of water from 72 to 38 mN/m at concentrations higher than 15 mu g/mL and its relative emulsion volume (EV%) was equal to 36%. It also showed stable surface activity over a wide range of temperature (45-85A degrees C) and pH (3-11).