The critical micelle concentration (CMC) is the minimum biosurfactant
concentration necessary to reduce the surface tension to
the maximum extent. The biosurfactant from B. amyloliquefaciens
An6 showed a great surface tension reduction capacity since the
water surface tension was reduced from 72 to 29 mN/m with the
increase of the biosurfactant concentration up to CMC of 100 mg/L
(Fig. 2). From this point the increase of biosurfactant concentration
did not lead to further reductions in water surface tension, indicating
that the CMC had been reached.