FOAMING PROPERTIES OF SURFACTIN, A LIPOPEPTIDE BIOSURFACTANT FROM BACILLUS-SUBTILIS

Foaming properties of surfactin were investigated and compared to thos e of sodium dodecyl sulfate (SDS) and bovine serum albumin (BSA). Foam s were formed by a bubbling technique. Evolution of the foam volume an d the liquid in the foam was monitored with optical and conductimetric methods to characterize foam formation and stability. Excellent foami ng properties of surfactin were shown by its higher ability to form an d stabilize the foam at a concentration as low as 0.05 mg/mL, in compa rison with SDS and BSA. Surfactin produced a foam with intermediate ma ximum density and stabilized the liquid in foam, as well as BSA.