Biosurfactant production using molasses and whey under thermophilic conditions

Biosurfactant production was studied by Bacillus licheniformis K51, B. subtilis 20B, B. subtilis R1 and Bacillus strain HS3 using molasses or cheese whey as a sole source of nutrition at 45 °C. The isolates were able to grow and produce biosurfactant under shaking as well as static conditions. Maximum biosurfactant production was achieved with molasses at 5.0–7.0% (w/v). The biosurfactant retained its surface-active properties after incubation at 80 °C at a wide range of pH values and salt concentrations for nine days. Oil displacement experiments in sand pack columns with crude oil showed 25–33% recovery of residual oil.