Abstract: | Glucose is also the main carbon source used by the cells of Sacch. cerevisiae for growing and reproduction, both in laboratory and industrial cultivation conditions. Sacch. cerevisiae could also use other monosaccharide (D-fructose, D-galactose, D-mannose, D-ribose), as well as disaccharides (saccharose, maltose and even lactose), in the same purpose (Anghel et al., 1989). The fission yeast S. pombe and the budding yeast Sacch. cerevisiae uses, as nitrogen sources (similar to other yeasts), the inorganic nitrogen combinations, or the organic nitrogen.
The transport mechanisms of sugars and amino acids into S. pombe and Sacch. cerevisiae cells are now well known: these molecules could be absorbed from the culture medium even by passive diffusion or by active transport against the concentration gradient, using the specific carrier-proteins, located in plasmalema (Coen et al., 1994). Sacch. cerevisiae is able to convert sugars, in order to provide its vital energy and carbon backbones, even by fermentation (or anaerobic glycolysis, via the Embden – Meyerhof – Parnas pathway), even by aerobic cathabolisation (via the Krebs cycle and cytochromes chain) (Brul et al, 1997).
Less is known about the relations between the sugars and protein metabolisation during the cell cycle of S. pombe and Sacch. cerevisiae and this is the main topic of the present paper. |
