Influence of oxygen tension on the physiology ofSaccharomyces cerevisiae in continuous culture
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- Brown, C.M. & Johnson, B. Antonie van Leeuwenhoek (1971) 37: 477. doi:10.1007/BF02218518
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The effect of decreasing oxygen tensions on the physiology and composition ofSaccharomyces cerevisiae was studied in galactose-limited continuous cultures. Between oxygen tensions of 75 and 3 mm Hg the metabolism of galactose was oxidative and cell composition constant. Below 3 mm Hg a more fermentative metabolism was operative resulting in low cell yields and accumulation of ethanol in culture filtrates. This correlated with an increased alcohol dehydrogenase and a decreased particulate NADH oxidase activity of cell extracts. While the cellular contents of RNA and protein were not altered at low oxygen tensions there were marked changes in those of carbohydrates and lipids. Below 3 mm Hg there were decreases in most lipid constituents but those of membrane constituents such as sterol esters and phosphatides together with unsaturated fatty acids were most evident. ATP pool size was lowest and amino acid pool size highest at low oxygen tensions. The increased amino acid pool size was due to higher concentrations of arginine and aspartate.