Yeast is a kind of organism that has been used for a long time. It is called the first "domesticated microorganism". Yeast can also be used for wine making.Until now, the use of yeast has been greater, and its fermentation is often used to make all kinds of flour food and wine.The following is an introduction to yeast.

1. Distribution of yeast

Yeasts are widely distributed and mainly grow in acidic sugar - containing environments.Yeasts, such as fruits, vegetables, preserves, and in orchard soil, are also easily isolated from animal waste, milk, oil fields, and soil near oil refineries.

2. Colony characteristics of yeast

The colony features of most yeasts are similar to the bacteria, but larger and thicker than the bacteria colony. The colony surface is smooth, moist and sticky, easy to pick up, and the texture of the colony is uniform, and the color of the front and back sides, edges and central parts are all uniform. The colonies are mostly milky white, a few red, and some black.

3. Shape, size, and structure of yeast cells

3.1 shape: usually spherical, ovoid, salami, oval, lemon or lotus root, etc.

3.2 size: generally, it is about 1-5 nm in width, up to 10 nm in height, and about 5-20 nm in length, up to 50 nm in height, which is several times to dozens of times larger than bacteria.

3.3 structure: yeast has no flagella and cannot swim.Similar to higher organisms, eukaryotes.However, there is no golgi body common in higher plant and animal species, and it has cell wall, cell membrane, nucleus, cytoplasm, vacuole, mitochondria, and some have microbodies.

Oct.22, 2018