EFFECT OF IMMOBILIZATION UPON THE PROPERTIES AND BEHAVIOR OF SACCHAROMYCES-CEREVISIAE CELLS

The destiny and behaviour of Saccharomyces cerevisiae SL 100 cells entrapped for a long-term period (up to 5 years) in calcium alginate gel beads were studied. For the entire experimental time the calcium alginate beads proved to be mechanically stable. In the course of this time, the beads were exposed to extreme conditions for living yeast cells being employed in long-term continuous cultivations and being stored in water at 4-degrees-C or in 60% sucrose solution at 20-25-degrees-C. During long-term continuous anaerobic process (1100 h cultivation) performed in a packed bed reactor on complete medium at 30-degrees-C, immobilized cells retained high metabolic activity. It was further confirmed that beads may be stored for a long time before application or between cultivations, even longer than 1 year, without loosing glycolytic activity and viability. The metabolic activity was found in cells immobilized in calcium alginate beads older than 5 years and having been stored for the entire time in 4-degrees-C water as nongrowing and starveling immobilized culture.