• Saccharomyces cerevisiae is used in baking and brewing.Yeast dough image by Elzbieta Sekowska from Fotolia.com
  
  Saccharomyces cerevisiae, also known as baker's yeast or brewer's yeast, is a common ingredient used to make bread and beer. It thrives in warm temperatures when exposed to a sugary food source, and it is intentionally cultivated in the home with relative ease. Under some conditions, saccharomyces cerevisae can infect humans, causing pain and swelling and posing serious threats to those with compromised immune systems.
  
  

Intentional Cultivation

• Because of its usefulness as a leavening agent in baking and brewing alcoholic beverages, saccharomyces cerevisiae is often intentionally bread and redistributed commercially. Under the more common name of baker's yeast, grocery stores and co-ops sell it in small envelopes portioned for specific recipes. Home brewing stores also sell this yeast. Once purchased, the yeast is easily cultivated in the home by providing it with a suitable substrate (usually corn syrup) and keeping it at temperatures of about 90 degrees Fahrenheit.
  
  

Naturally Occuring

• Saccharomyces cerevisae is hardy and prolific under ideal temperatures and will reproduce on the surface of grapes. When present, the yeast appears as a white film on the skin of the grape. Grapes with sufficiently-established colonies of saccharomyces cerevisae will serve as breeding grounds, from which the yeast will spread to other grapes or fruits.
  
  

Saccharomyces Cerevisae Fungemia

• While useful in cooking, Saccharomyces Cerevisae is also responsible for the infection fungemia. This condition occurs in patients being treated with probiotic preparations of the organism, but it can adversely affect those with compromised immune systems. Other patients in proximity to an infected individual can acquire fungemia as well. This typically occurs through blood contamination as the skin is penetrated by contaminated needles, but it can be transferred by touch or through the air to infants, the elderly and others with weakened immunity. Because saccharomyces cerevisae commonly grows on many foods kept in the home, unsanitary conditions can facilitate its spread from food to individuals susceptible to fungemia.