EFFECT OF CELL-WALL POLYPHOSPHATES ON THE SENSITIVITY OF SACCHAROMYCES-CARLSBERGENSIS TO CETYLTRIMETHYLAMMONIUM BROMIDE

The effect of cetyltrimethylammonium bromide (CTAB) on Saccharomyces c arlsbergensis cells grown in orthophosphate-containing medium and on c ells starved of phosphorus was studied by electroorientation spectrosc opy. CTAB (20 mu M) was found to substantially damage the plasma membr ane (PM) of cells grown in the presence of orthophosphate, while cells starved of phosphorus were damaged to a lesser extent. Biochemical an alysis of the content of inorganic polyphosphate (poly(P-i)) in the ce lls, as well as study of their capacity to adsorb 9-aminoacridine, a f luorescent cationic dye, suggested that the different sensitivity of t he plasma membrane to CTAB was due to differences in the content of th e polyanionic molecules of poly(P-i) in the cell wall and consequent d ifferences in its net negative charge. Magnesium cations increased the time of CTAB penetration through the cell wall and reduced the damage inflicted on the PM.