Acclimation of Tetrahymena thermophila to bulk and nano-TiO2 particles by changes in membrane fatty acids saturation

► Tetrahymena thermophila was exposed to TiO2 particles at sub-toxic concentrations. ► Exposure to TiO2 particles resulted in changed cell membrane in fatty acid profile resulting in increased membrane rigidity. ► Altered cell membrane composition is not accompanied by lipid peroxidation or ROS elevation. ► Particles were detected in food vacuoles where filling and subsequent release was followed.