Foaming properties of lipopeptides produced by Bacillus subtilis: effect of lipid and peptide structural attributes

in Journal of Agricultural and Food Chemistry (1998), 46(3), 911-916

To study the effect of lipid and peptide structural attributes of Bacillus subtilis lipopeptides on their foaming properties, the formation, stability, and appearance of foams prepared with surfactins ... [more ▼]

To study the effect of lipid and peptide structural attributes of Bacillus subtilis lipopeptides on their foaming properties, the formation, stability, and appearance of foams prepared with surfactins (C13 C15) and iturins A (C14 C17) were characterized. The density and stability of lipopeptide foams depend on both the alkyl chain hydrophobic character and peptide molecular intrinsic properties. A lipidic chain length of 14 carbon atoms provides lipopeptides with the best foaming properties in terms of foam density and liquid stability in foams. Increases in alkyl chain length above 15 carbon atoms result in a drastic decrease of iturin A foam density. With the same alkyl chain, surfactin produces denser foam whereas iturin A exhibits better foaming stability. These results demonstrate the importance of the peptide structural attributes of B. subtilis on their foaming properties. [less ▲]

Interfacial and emulsifying properties of Bacillus suvtilis lipopeptides

Poster (1997)

Surface-active properties of surfactin iturin A mixtures produced by Bacillus subtilis

in Langmuir (1997), 13(23), 6026-6031

Surface-active properties including dynamic adsorption, monolayer stability, micelle forming capacity, and foaming aptitudes of surfactin-C-15/iturin A-C-15 mixtures were studied. Surfactin-C-15 and ... [more ▼]

Surface-active properties including dynamic adsorption, monolayer stability, micelle forming capacity, and foaming aptitudes of surfactin-C-15/iturin A-C-15 mixtures were studied. Surfactin-C-15 and iturin A-C-15 molecules interact in synergism on the most surface-active properties evaluated at 20 degrees C at the air-water interface and in aqueous solution (pH 8.0). The synergism is positive on the adsorption effect, monolayer stability, foam density, and liquid stability in foam, whereas it is negative on the adsorption rate. No synergism occurs an micelle forming capacity, but surfactin-C-15 and iturin A-C-15 form mixed micelles when the solution contains a low proportion of surfactin-C-15.ses the synergistic effect is maximum when surfactin-C-15 and iturin A-C-15 molecules are mixed in a 2:3 ratio. This is attributed to the surfactin/iturin A complex formation resulting from specific interactions among two surfactin-C-15 molecules and three iturin A-C-15 molecules. A model of such a complex formation is proposed. [less ▲]

Foaming Properties Of Surfactin, A Lipopeptide Biosurfactant From Bacillus Subtilis

in Journal of the American Oil Chemists' Society [=JAOCS] (1996), 73(1), 149-151

Foaming properties of surfactin were investigated and compared to those of sodium dodecyl sulfate (SDS) and bovine serum albumin (BSA). Foams were formed by a bubbling technique. Evolution of the foam ... [more ▼]

Foaming properties of surfactin were investigated and compared to those of sodium dodecyl sulfate (SDS) and bovine serum albumin (BSA). Foams were formed by a bubbling technique. Evolution of the foam volume and the liquid in the foam was monitored with optical and conductimetric methods to characterize foam formation and stability. Excellent foaming properties of surfactin were shown by its higher ability to form and stabilize the foam at a concentration as low as 0.05 mg/mL, in comparison with SDS and BSA. Surfactin produced a foam with intermediate maximum density and stabilized the liquid in foam, as well as BSA. [less ▲]