Morphological response of Yarrowia lipolytica under stress of heavy metals.

Abstract

The marine dimorphic yeast Yarrowia lipolytica has been proposed as a suitable model for the dimorphism study. In this study, the morphological behaviour of two marine strains of Y. lipolytica (NCIM 3589 and NCIM 3590) was studied under stress of different heavy metals. Scanning electron microscopy was used to investigate the morphological features of yeast cells. This study revealed that the normal ellipsoidal shape of yeast cells was changed into oval, rounded, or elongated in response to different heavy-metal stress. Light microscopy was also used to investigate individual properties of yeast cells. The average cell length and radius of both marine strains was increased with increasing concentrations of heavy-metal ions. In addition, the elongation factor was calculated and was increased in the presence of heavy metals like Pb(II), Co(II), Cr(III), Cr(VI), and Zn(II) under the static conditions.