YEAST PROTOPLASTS FROM STATIONARY AND STARVED CELLS - PREPARATION, ULTRASTRUCTURE AND VACUOLAR DEVELOPMENT

  • 1 January 1977
    • journal article
    • research article
    • Vol. A128  (1) , 3-+
Abstract
The conversion of stationary and starved yeast cells into protoplasts was described. The method is rapid, simple and can be applied to a variety of stationary yeast cells. Pre-incubation of yeast cells in the presence of pronase was essential for effective conversion into protoplasts. Baker''s yeast and 7 defined yeast strains, including 1 petite, were studied. All of them were efficiently transformed into protoplasts in 60-90 min, depending on the strain culture conditions and the age of the culture. Protoplasts may be obtained even from late-stationary cells which contain spores. Saccharomyces cerevisiae cells subjected to complete starvation conditions in water were completely transformed into protoplasts, even after 48 h of starvation. EM examination of stationary protoplasts from 3 different yeast strains showed no evidence of a remaining cell-wall. S. cerevisiae stationary cells show a very developed vacuolar system, a number of lipid granules and a few altered mitochondria. Endomycopsis fibuliqera and Candida tropicalis stationary protoplasts show a similar fine structure, but lipid granules were completely absent.