Factorial Design to Optimize Biosurfactant Production by Yarrowia lipolytica

In order to improve biosurfactant production by Yarrowia lipolytica IMUFRJ 50682, a factorial design was carried out. A 2(4) full factorial design was used to investigate the effects of nitrogen sources (urea, ammonium sulfate, yeast extract, and peptone) on maximum variation of surface tension (ΔST) and emulsification index (EI). The best results (67.7% of EI and 20.9 mN m(−1) of ΔST) were obtained in a medium composed of 10 g 1(−1) of ammonium sulfate and 0.5 g 1(−1) of yeast extract. Then, the effects of carbon sources (glycerol, hexadecane, olive oil, and glucose) were evaluated. The most favorable medium for biosurfactant production was composed of both glucose (4% w/v) and glycerol (2% w/v), which provided an EI of 81.3% and a ΔST of 19.5 mN m(−1). The experimental design optimization enhanced ΔEI by 110.7% and ΔST by 108.1% in relation to the standard process.