Enhanced Production of Citric Acid in Yarrowia lipolytica by Triton X-100

Various chemical surfactants could affect permeability of yeast cells. In this study, effects of the surfactant addition upon yeast cells permeability and citric acid (CA) production by Yarrowia lipolytica strains DSM 3286 and M7 were investigated. The addition of Triton X-100 increased 1.4–1.8-fold of the maximum CA quantity achieved for both strains, with final CA concentrations ranging between 75–85 g/l that correspond to CA conversion yields per unit of glucose consumed of ~0.80–0.84 g/g. Scanning electron micrographs of yeast cells showed that the cells treated with Triton X-100 had altered cell structure and were smaller and narrower compared with the non-treated ones. The results showed that Triton X-100 could be used in order to increase the efficiency of CA production by Y. lipolytica strains.