engleski

High mortality and morphological changes of wt+SCW4, wt+SCW10, wt+SCW11 and wt+BGL2 strains of Saccharomyces cerevisiae

The yeast cell wall consists of polysaccharides to which various proteins are attached. In order to investigate the role of non-covalently bound yeast cell wall proteins, Saccharomyces cerevisiae was transformed with BG1805 plasmids, each carrying gene for one protein of interest. Protein expression was under control of inducible GAL promoter. The aim was to determinate the mortality rate and detect possible morphological changes in wt+SCW4, wt+SCW10, wt+SCW11 and wt+BGL2. wt+SCW4 grown in media with no galactose added served as the negative control. Strains were monitored for two weeks after inoculation. The number of dead cells was estimated by methylene blue staining. All strains had increased mortality compared to the control. wt+SCW4 and wt+SCW10 show characteristic morphological changes which manifest as drastic cell volumen enlargement and presence of cells only with outline remains visible, so-called ghost cells. Characteristic volume enlargement could be the direct consequence of cell wall weakening that led to rupture of the cell and leakage of cellular contents. The fact that this features were not characteristic for wt+SCW11 and wt+BGL2 could indicate that this strains died for different reasons than wt+SCW4 and wt+SCW10.

wt+SCW4; wt+SCW10; wt+SCW11; wt+BGL2

nije evidentirano