Yeasts are eukaryotic micro-organisms classified in the kingdom Fungi, with about 1,500 species currently described they dominate fungal diversity in the oceans. The yeast species Saccharomyces cerevisiae has been used in baking and fermenting alcoholic beverages for thousands of years. It is also extremely important as a model organism in modern cell biology research, and is one of the most thoroughly researched eukaryotic microorganisms
Yeasts are very common in the environment,
1) Mainly isolated from sugar-rich material. Examples include naturally occurring yeasts on the skins of fruits and berries (such as grapes, apples or peaches), and exudates from plants (such as plant saps or cacti). Some yeast is found in association with soil and insects.
2) The ecological function and biodiversity of yeast is relatively unknown compared to those of other microorganisms.
3) Yeasts including Candida albicans, Rhodotorula rubra, Torulopsis and Trichosporon cutaneum have been found living in between people’s toes as part of their skin flora.
3) Yeasts are also present in the gut flora of mammals and some insects.
4) Bioremediation of hydrocarbons. Some yeast has application in the field of bioremediation. One such yeast, Yarrowia lipolytica, is known to degrade palm oil mill effluent, TNT (an explosive material) and other hydrocarbons such as alkanes, fatty acids, fats and oils. It can also tolerate high concentrations of salt and heavy metals, and is being investigated for its potential as a heavy metal biosorbent.
Crude oil is a mixture of hydrocarbons of different sizes. Different micro organisms break down hydrocarbons of different sizes.
Use in aquatic environment
Yeast is often used by aquarium hobbyists to generate carbon dioxide (CO2) to fertilize plants in planted aquariums. In a homemade setup is widely used as a cheap and simple alternative to pressurized CO2 systems. The CO2 is used by plants in the photosynthesis process; it is very important to plant growth. It is completely safe for fish and other aquatic animals.
Human consumption:
Natural supplements and Probiotics for human consumption Yeast is used in nutritional supplements popular with vegans and the health conscious, where it is often referred to as “nutritional yeast”. It is usually Saccharomyces cerevisiae.
It is an excellent source of protein and vitamins, especially the B-complex vitamins, whose functions are related to metabolism as well as other minerals and cofactors required for growth.
Some probiotic supplements use the yeast Saccharomyces boulardii to maintain and restore the natural flora in the large and small gastrointestinal tract. S. boulardii has been shown to reduce the symptoms of acute diarrhea in children, prevent reinfection of Clostridium difficile, reduce bowel movements in diarrhea predominant IBS patients, and reduce the incidence of antibiotic, traveler’s, and HIV/AIDS associated diarrheas.
All About the little Microbes 