A New Biosurfactant Produced by Candida glabrata UCP 1002: Characteristics of Stability and Application in Oil Recovery

The production of a new biosurfactant by Candida glabrata UCP 1002 was studied to evaluate the influence of the concentration of the cotton seed oil, glucose and yeast extract. The dynamics of the growth and surfactant production were showed for all the cultivation conditions studied. The best emulsification of the n-hexadecane, quantified by the emulsifying index was observed in the medium containing 7.5% cotton seed oil, 5% glucose and 0.3% yeast extract. The isolated biosurfactant showed a CMC of 2.5% and the surface tension at that point showed to be 31 mN/m. The potential application of the biosurfactant in oil recovery from the sand, in acid and alkaline environments and over exposure to high salinity and different temperatures was demonstrated by the percentage of oil removal and by the stability of the surface tension, respectively.