The role of yeast

We probably eat bread frequently in our daily lives, but many times we are not aware of the presence of yeast. The role of yeast is quite important for bread. Without yeast, it may not feel fluffy, so we should not ignore yeast in our daily life. Yeast is a relatively common single-cell organism that can make the air feel expanded.

Yeast has a strong vitality. It can be found in both aerobic and anaerobic conditions, which shows its vitality. But we may rarely use this type of fungus except in food. We can also use it to make delicious wine.

Yeast is a single-celled microorganism. It belongs to the fungi class of higher microorganisms. Like the cells of higher plants, it has a nucleus, cell membrane, cell wall, mitochondria, the same enzymes and metabolic pathways. Yeast is harmless and easy to grow. It can be found in the air, soil, water, and in animals. It can survive with or without oxygen.

Yeasts can live as obligate or facultative anaerobes. For yeasts that are not obligate anaerobic, in the absence of oxygen, fermentative yeasts obtain energy by converting sugars into carbon dioxide and ethanol (commonly known as alcohol).

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Colonies of various yeasts

Most yeasts can be isolated in sugar-rich environments, such as some fruits (grapes, apples, peaches, etc.) or plant secretions (such as cactus juice). Some yeasts live inside insects. Yeast is a single-cell eukaryotic microorganism, which is usually spherical, oval, sausage-shaped, elliptical, lemon-shaped or lotus-node-shaped. It is much larger than the single-cell individuals of bacteria, generally 1 to 5 microns or 5 to 20 microns in size. Yeast do not have flagella and cannot swim. Yeast has a typical eukaryotic cell structure, including cell wall, cell membrane, nucleus, cytoplasm, vacuole, mitochondria, etc. Some also have microbodies.

The genetic material of yeast consists of nuclear DNA, mitochondrial DNA, and special plasmid DNA.

The colony characteristics of most yeasts are similar to those of bacteria, but they are larger and thicker than bacterial colonies. The surface of the colonies is smooth, moist, and sticky, and they are easy to pick up. The colonies have a uniform texture, and the colors of the front and back sides, edges, and center are very uniform. Most colonies are milky white, a few are red, and some are black.

Yeasts whose sexual stages are not found are called pseudoyeasts.

The relevant introduction of yeast is presented in detail in this article. First of all, yeast has relatively strong vitality. And this type of fungus can play many roles in food. Without yeast we will lose a lot of delicious food. We can make some food ourselves in daily life.