1. Saccharomyces cerevisiae yeast

1.1 Key features

Bakers' yeast is a single-celled fungus of the Ascomycetes class, of the Saccharomyces genus (the name refers to its affinity for sugar) and the cerevisiae species (the name refers to its role in beer production); the name Saccharomyces cerevisiae was given to brewers' yeast in 1838 by Meyer.

Under the light microscope, individual cells can be seen, ovoid in shape and 4 to 10 µm in diameter. One gram of pressed yeast contains 8 to 10 billion cells. An electron microscopic section shows, from outside to inside, the cell wall, cytoplasmic membrane, nucleus, vacuoles, ribosomes and mitochondria (figure 1 ).

...