Saccharomyces cerevisiae is one of the few yeast species that can grow equally well without molecular oxygen (anaerobic) as with this compound present (aerobic). This property has made it one of... Show moreSaccharomyces cerevisiae is one of the few yeast species that can grow equally well without molecular oxygen (anaerobic) as with this compound present (aerobic). This property has made it one of the most abundantly used yeasts in industry, since anaerobic incubation plays a major part in alcohol and bread industry. With the experiments described in this thesis it has been shown that apart from metabolic changes, an adaptation of the cell wall and the plasma membrane is very important for anaerobic growth. There seems to be a connection between this adaptation and the import of sterols, which are essential when no molecular oxygen is present. The importance of these adaptations becomes clear when the genomes of the facultative anaerobic Saccharomyces cerevisiae and the obligatory aerobic Kluyveromyces lactis are compared. K. lactis does not have any genes that encode for a sterol import system.The adaptation of the cell wall and the plasma membrane to anaerobic conditions is extensive and regulated in a complex way, as is apparent from the transcriptome data. Our experiments show that Snf7 is, at least in part, responsible for these changes. Show less