Biosurfactants emulsifies hydrocarbons present in the crude oil, and increases the water solubility, decreases surface tension and increases the displacement of oily substances from the porous medium
Figure 3a shows the production of biosurfactant as a function of time. The biosurfactant production was observed to be 0.98 g/L in 1 day, and maximum 4.1 g/L in 10 days. The production of biosurfactants was also confirmed by the observed reduction in surface tension and increase in emulsification in waxy crude oil culture. Surface tension is reduced to 25 mN/m in 10 days and 21 mN/m in 20 days and there was no further change