The World of Yeast

Posted on May 27th, 2016

Yeast comes in various forms, shapes and many different species.

Over 1500 different species of yeast have been identified throughout the world and the scientific community believes the species that have been identified, may represent only be 1 %.

Yeast is thought to be a fungus and is classified as a eukaryotid.

According to Wikipedia, the word yeast, comes from the Old English word (gist, gyst), and from the Indo-European word (yes) meaning boil, foam or bubble.

Yeast was discovered as early as 4000 years ago by the archaeologist in the drawings from the Egyptian ruins, of breweries and bakeries.

Van Leeuwenhoek observed to first yeast organisms through the lens of his microscope, in 1680.

Louie Pasteur, in 1857, found that yeast did produce alcohol and not a chemical catalyst.

He also found that by bubbling oxygen into yeast broth, it stopped fermentation and enhanced the growth of the yeast.

Most yeast species are 3 to 4 um in diameter but can be as large as 40 um.

Most yeast can replicate asexually which means they do not need a mate to replicate.

Their growth comes through cellular reproduction, called mitosis.

Yeast has been divided up into two different groups, referred to as Ascomycota and Basidiomycota.

The true yeast, as most of us know it, comes from the budding yeast, Saccharomyces.

Yeast is found in the all mammals, insects and even in the animals that frequent the depths of our oceans. It is found in the normally, in the gut of mammals and in some insects.

Wikipedia reports that yeast is also found where there is an increased amounts of sugars, like in the skins of fruits, berries, grapes, apples, peaches and exudates from plant saps and cacti.

Yeast provides many different functions that help our environment to live and prosper.



  1. Beer
  2. Wine
  3. Nonalcoholic beverages
  4. Bakery goods
  5. Bioremediation = Some yeast has the ability to make explosives, hydrocarbons, alkanes, fatty acids and fatty acid oils
  6. Bio sorbent = The ability to bind damaging heavy metals like arsenic
  7. Industrial ethanol production (fuel)


Many people look to yeast as a natural healthy, nutrient, that helps fill the needs of many people especially those that are vegans. It is referred to as a nutritional yeast

Nutritional yeast is a deactivated yeast.

It often comes in the form of a yellow flakes that does look similar to cornmeal.

It is used specifically as a flavorful, nutrition, topping for popcorn, mashed potatoes, fried potatoes and scrambled eggs.


  1. Protein
  2. Vitamins = B Complex with little or no vitamin B12
  3. Minerals
  4. Co-factors for growth
  5. Naturally low in sodium = May benefit cardiac patients whether human or animal
  6. Probiotic= some forms of probiotic contain the very important yeast S. boulardii, which does the following;
  1. Restores the natural flora of the gut
  2. Reduces symptoms and signs of diarrhea
  3. Reduces cholesterol with competitive inhibition with bile in the gut
  4. Reduces the quantity of bowel movement in IVD patients
  5. Reduces the incidence of diarrhea due to antibiotics, travel and HIV/AIDS


Some species of yeast are pathogenic and if the opportunity presents itself, they will cause major health problems, especially in humans and animals that have endocrine immune imbalances. They are as follows;

  1. Cryptococcus getti = this is the yeast that causes the fungal infections in one million AIDS patients every years and leads to 600,000 deaths
  2. Candida yeast species = this species can cause infection and inflammation of the mucous membranes of the intestinal and urogenital tracts, including the bloodstream

The world of yeast is huge and larger than anyone of us could have ever imagined.

It is obvious that yeast has many different applications and uses that still need to be identified,

My interest as a practicing, veterinary clinician, involves the use and application of different species of yeast as they are formulated for use in products that help create better health.

The laboratory growth and preparations of these probiotic products is vital to their effectiveness and they take time to be grown and harvested correctly.

It is vital for you as a pet owner, to question the probiotic manufacturer in order to make sure their product is biological active and contains those species of yeast, that are vital for continued good health.

These are only my thoughts, and I hope they will help you and your pet have a healthier future.


Dr. AL Plechner