The applicability of the biosurfactant for bioremediation also
depends on their stability at different pH, salinity, and temperature.
In the present study, the surface activity of biosurfactant
was stable from pH 4.0 (29.5 mN/m) to pH 12.0 (31 mN/m) with
minimal variation in ST and the highest stability (28 mN/m) at
pH 6.0 as shown in Fig. 3A. The effect of pH on surface activity is
consistent with those reported in the literature for biosurfactants
produced from different microorganisms [29].