Certain fatty acids and steroids protect Tetrahymena from cell division stress caused by shaking

Cultures of Tetrahymena are routinely shaken to ensure proper access to oxygen. Recent work showed that growth of dilute cultures (inocula < 10(4) cells ml-1) of T. pyriformis was sensitive to shaking. Addition of oleic acid (9 microM) or linoleic acid (140 microM) before or at the onset of shaking gave considerable protection to the cells. A similar effect was seen with ergosterol (25 microM) and to some extent with cholesterol (100 microM). Octanoic acid (20 microM), palmitic acid (140 microM) and palmitoleic acid (100 microM) had no effect. Paraquat (230 microM), which induced peroxidation of unsaturated fatty acids, increased the effect of shaking-induced cell division stress. Such results may be due to changes in the membrane composition of Tetrahymena. It has not been possible to demonstrate differences in the 14C-oleic acid labelling of phospholipids of cells with and without shaking.