A systematic investigation of the growth mode and appearance of two cell wall enzymes (invertase E.C. 3.1.1.26) and acid phosphatase (E.C. 3.1.3.2.) in frre and immobilized cells of Saccharomyces cerevisiae was carried out. Gel etrapped yeast cells were simulated into growth by incubation in media differing from one another in composition, under different experimental conditions. In immobilized cells, lower growth rates were observed whoich mainly due to the resistance of the matrix to nutrient diffusion. Invertase activity reached levels higher than those of corresponding free cells. This result was independent of the cultural system adopted for growth and of the nature of the gel matrix chosen for immobilization, and could not be explained merely in terms of diffusional resistance. A possible explanation could be some physiological change relating to the state of immobilization of the yeast cells. What was observed with invertase seems to be peculiar to this enzyme, as the extent of repression, in the case of acid phoshatase, was almost the same for both free and gel immobilized cells.
Invertase and acid phosphatase in free and gel-immobilized cells of Saccharomyces cerevisiae grown under different cultural conditions
PARASCANDOLA, Palma;
1993-01-01
Abstract
A systematic investigation of the growth mode and appearance of two cell wall enzymes (invertase E.C. 3.1.1.26) and acid phosphatase (E.C. 3.1.3.2.) in frre and immobilized cells of Saccharomyces cerevisiae was carried out. Gel etrapped yeast cells were simulated into growth by incubation in media differing from one another in composition, under different experimental conditions. In immobilized cells, lower growth rates were observed whoich mainly due to the resistance of the matrix to nutrient diffusion. Invertase activity reached levels higher than those of corresponding free cells. This result was independent of the cultural system adopted for growth and of the nature of the gel matrix chosen for immobilization, and could not be explained merely in terms of diffusional resistance. A possible explanation could be some physiological change relating to the state of immobilization of the yeast cells. What was observed with invertase seems to be peculiar to this enzyme, as the extent of repression, in the case of acid phoshatase, was almost the same for both free and gel immobilized cells.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.