Effect of aqueous extracts of some plants of Lamiaceae family on the growth of Yarrowia lipolytica

Aqueous extracts of some plants belonging to the Lamiaceae family (Sideritis montana, Origanum dictamnus, Mentha piperita, Rosmarinus officinallis and Origanum marjorana) caused an important increase of the lag time of Yarrowia lipolytica. Especially, Origanum dictamnus and Rosmarinus officinallis extracts enhanced the lag time considerably and influenced negatively the specific growth rate of this yeast. In culture media having low C/N ratio, all plant extracts caused an increase of the biomass produced in relation to glucose and nitrogen consumed, while, in high C/N ratio media the effect of the extracts on biomass production was negative. In the presence of aqueous plant extracts, in low C/N ratio culture media, the ratio Σ unsaturated/Σ saturated fatty acids in the cellular lipids increased, whereas in high C/N ratio media it decreased.