Yeast is a typical heterotrophic and facultative anaerobic microorganism, which can survive in both aerobic and anaerobic environments. The demand of yeast for oxygen is variable. In the case of oxygen, it breaks down sugar into carbon dioxide and water, and yeast grows faster. In the absence of oxygen, yeast breaks down sugar into alcohol and carbon dioxide.

Physiological characteristics:

Yeast is a single-celled microorganism. It belongs to fungi of higher microorganisms. There are nuclei, cell membranes, cell walls, mitochondria, the same enzymes and metabolic pathways. Yeast is harmless and easy to grow. It exists in air, soil, water and animals. You can live with or without oxygen.

Yeast is a facultative anaerobic organism, and no obligate anaerobic yeast is found. In the absence of oxygen, fermented yeast obtains energy by converting sugar into carbon dioxide and ethanol (commonly known as alcohol).

the genetic material composition of yeast: nuclear DNA, mitochondrial DNA and special plasmid DNA.