Yeast is a facultative anaerobe. What does that mean?

Sourav PanAugust 19, 2024

Answered

Yeast being a facultative anaerobe means that it can survive and grow in both the presence and absence of oxygen. Specifically, yeast can switch between two different metabolic processes depending on the availability of oxygen:

1. Aerobic Respiration: When oxygen is present, yeast uses it to perform aerobic respiration, which is a highly efficient process that breaks down glucose into carbon dioxide and water, producing a large amount of energy (ATP).
2. Anaerobic Fermentation: In the absence of oxygen, yeast switches to anaerobic fermentation, a less efficient process where glucose is converted into ethanol and carbon dioxide, producing a smaller amount of energy. This process is commonly used in brewing and baking, where yeast ferments sugars to produce alcohol in beverages like beer and wine or carbon dioxide in bread.

In summary, as a facultative anaerobe, yeast can adapt to different environmental conditions by altering its metabolism based on the availability of oxygen.