Chemical composition and morphological changes in the cells in a chemostat Candida utilis culture inhibited by zinc ions

: The effect of zinc ions on the physiological state of Candida utilis VKM Y-1668 was studied during its chemostat cultivation. The concentration of zinc ions was maintained at a constant level. Zinc was found to inhibit the growth at a concentration of 300 mg/l. The cells were rapidly washed from the fermenter when zinc concentration was increased to 500 mg/l. Zinc uptake by the culture became greater when zinc concentration in the medium was gradually increased. If the yeast was cultivated in the presence of the inhibitor, the content of protein, RNA, DNA and polysaccharides fell while lipid content increased. Growth inhibition by zinc ions interfered with cell division; the cells could not separate from one another and formed catenae and conglomerates.