Oxygen requirements of yeasts.
Type species of 75 yeast genera were examined for their ability to grow anaerobically in complex and mineral media. To define anaerobic conditions, we added a redox indicator, resazurin, to the media to determine low redox potentials. All strains tested were capable of fermenting glucose to ethanol in oxygen-limited shake-flask cultures, even those of species generally regarded as nonfermentative. However, only 23% of the yeast species tested grew under anaerobic conditions. A comparative study with a number of selected strains revealed that Saccharomyces cerevisiae stands out as a yeast capable of rapid growth at low redox potentials. Other yeasts, such as Torulaspora delbrueckii and Candida tropicalis, grew poorly mu max, 0.03 and 0.05 h-1, respectively) under anaerobic conditions in mineral medium supplemented with Tween 80 and ergosterol. The latter organisms grew rapidly under oxygen limitation and then displayed a high rate of alcoholic fermentation. It can be concluded that these yeasts have hitherto-unidentified oxygen requirements for growth.
Visser
W
W
Department of Microbiology and Enzymology, Delft University of Technology, The Netherlands.
Scheffers
W A
WA
Batenburg-van der Vegte
W H
WH
van Dijken
J P
JP
D000693:Anaerobiosis; D000431:Ethanol / Q000378:metabolism; D005285:Fermentation; D007202:Indicators and Reagents; D008854:Microscopy, Electron; D008928:Mitochondria / Q000648:ultrastructure; D010078:Oxazines; D010084:Oxidation-Reduction; D010100:Oxygen / Q000378:metabolism*; D014966:Xanthenes; D015003:Yeasts / Q000254:growth & development / Q000378:metabolism* / Q000648:ultrastructure
D007202:Indicators and Reagents; D010078:Oxazines; D014966:Xanthenes; C005843:resazurin; D000431:Ethanol; D010100:Oxygen