A thousand-year-old heritage
For millennia, the action of yeast has been used empirically by man. The Babylonians worshipped the goddess of beer and living yeast, Nidaba, considered the goddess of healing. The Egyptians used beer foam to maintain beautiful skin and complexion. These people, as well as the Celts, also used it for its power of fermentation and for its qualities. Hippocrates also used living brewer’s yeast as a remedy and discovered its diuretic action. “How heavenly this yeast is! ”, some still say today.

It was only with the beginnings of microbiology that we gradually discovered the composition of yeast. In the 1800s, Thenard discovered the presence of yeast in all alcoholic fermentation as well as its nutritional effectiveness. The French chemist and physicist Gay-Lussac discovered the equation for alcoholic fermentation. We observe the multiplication of yeast by budding. We see that these microorganisms are everywhere in nature. The improvement of the microscope has enabled the exploration and discoveries of this microscopic world.

In 1837, the German physiologist, histologist and cytologist, Theodor Schwann recognized it as a mushroom and the scientist Meyen identified the yeast Saccharomyces cerevisiae. At the end of the 19th century, Pasteur and the first microbiologists established the foundations of the knowledge of microorganisms, of which yeast is one. This is the start of the production of baker’s yeast.
Over time, the foundations of knowledge of microorganisms will be established. At the beginning of the 20th century, different strains of yeast were identified, notably Saccharomyces cerevisiae and Saccharomyces cerevisiae boulardi (Henri Boulardi), a probiotic yeast.

From a yeast extract, enzymes and brewer’s yeast contains proteins which can advantageously replace plant and animal proteins. At this time, with the discovery of vitamins, pharmaceutical companies were born. This is the beginning of “biotechnologies” and certain industrial processes based on microorganisms (TNT).
We create centres in which we preserve microorganisms, like “libraries of life”, which preserve the different strains of Saccharomyces cerevisiae and other microorganisms. Today we think that there are around 1500 species of yeast, and even a little more. Saccharomyces cerevisiae alone would have a few hundred different strains.

With the discovery of DNA (1962), we opened the way to deciphering the genome of Saccharomyces cerevisiae (1996). We then realize the links between Saccharomyces cerevisiae and man (mammals), we have similar biological structures and cellular processes.
By discovering the mechanisms of cellular functioning and its components, we can further realize the full potential of Saccharomyces cerevisiae. Taking into account the qualities of Saccharomyces cerevisiae such as the variety of its components in essential nutrients and bioactive molecules, its metabolic capacities, its nutritional potential, we began to cultivate yeast for its own benefits: not just “harvesting” the residual brewer’s yeast from brewing beer. This, brewer’s yeast, is in some ways the ancestor of nutritional yeast. The process used to cultivate nutritional yeast in fermenters is part of early biotechnology.
