Growth of cells on solid culture medium. II. Cell physiological data of stationary yeast cells and the initiation of cell cycle in nutrient free buffer solution.

For precise experiments with yeast (or other) cells stationary populations are produced by growth on the surface of a solid nutrient medium. The energy supply to these cells is well known from a former publication. The oxygen supply during growth is analysed here in detail. Different types of cell populations can be produced in this way dependent on the thickness of nutrient medium. If such cells are transferred into a liquid buffer solution cell multiplication can be initiated without any nutrient flux into the cell. This new type of initiation of the cell cycle of G1-cells has to be distinguished from the usual initiation by nutrient supply and from the mechanism of meiotic cell division. The dependence of this cell growth on cell volume, pH-value, oxygen concentration and osmotic pressure is analysed and possibilities to avoid this kind of cell multiplication reaction are discussed.