The Single-celled fungi Are composed of a single cell and are yeasts, all other types of fungi are multicellular.
Yeasts are unicellular members of fungi and are commonly found in baking and brewing yeast. They are considered one of the earliest domesticated organisms known to man and can be found naturally in the skins of certain mature fruits.
The yeast is too small to be seen individually by the naked eye, but can be seen in large clusters of fruits and leaves as a white powdery substance. Some yeasts are mild to dangerous pathogens for humans and other animals, especially Candida albicans, Histoplasma and Blastomyces.
As a unicellular organism, yeast cells are rapidly colonized, often doubling the population size by 75 minutes to 2 hours. In addition, they are eukaryotic organisms that can not obtain their nutritional needs by photosynthesis and require a reduced form of carbon as a food source.
Yeasts play an important role in the industry, particularly in the areas of food and beer. The beer yeast Gets its name from its use as a fermentation agent in the brewing industry.
Carbon dioxide produced during the fermentation process of S. cerevisiae (in Latin beer) is also a yeast agent frequently used in the manufacture of bread and other baked goods.
Function of single-celled fungi
Single-celled organisms have a variety of functions, although they generally need to synthesize all the nutrients necessary for the cell to survive, as the organism must perform all processes for the cell to function and reproduce.
They are usually resistant to extreme temperatures, this means that they are able to survive in extremely cold or hot temperatures.
Single-celled fungi, such as yeast and mold, have a purpose. In addition to being used to make baked goods such as bread and in the production of beer and wine, it also has the important function of decomposing dead matter.
As mentioned, yeasts are eukaryotic organisms. They are typically about 0.075 mm (0.003 inches) in diameter. Most yeasts reproduce asexually in budding: a small bump protrudes from a stem cell, it enlarges, matures and detaches.
Some yeasts reproduce by fission, the stem cell divides into two equal cells. Torula is a genus of wild yeasts that are imperfect, never forming sexual spores.
Yeasts are widely dispersed in nature with an extensive variety of habitats. They are commonly found on leaves of plants, flowers and fruits, as well as on the ground.
They are also found on the surface of the skin and in the intestinal tracts of warm-blooded animals, where they may live symbiotically or as parasites.
The so-called"yeast infection"is typically caused by Candida albicans. In addition to being the causative agent of vaginal infections, Candida is also the cause of the eruption of the diaper and thrush of the mouth and throat.
In commercial production, the selected yeast strains are fed with a solution of mineral salts, molasses, and ammonia. When the growth stops, the yeast is separated from the nutrient solution, washed and packaged.
Baking yeast is sold in compressed cakes containing starch or dried in granular form mixed with corn flour.
Brewer's yeast and nutritional yeast can be eaten as a vitamin supplement. Commercial yeast is 50 percent protein and is a rich source of vitamins B1, B2, niacin and folic acid .
Yeast is a focus of study for researchers around the world, and today there are thousands of scientific articles.
This interest is because this unicellular fungus is an organism that grows rapidly in a flask and whose DNA can be easily manipulated, while providing insight into basic human biological processes, including diseases.
In addition, being single-celled organisms are easy to study and have a cellular organization similar to that found in higher and multicellular organisms like humans, that is, they have a nucleus and are therefore eukaryotes.
This similarity in the cellular organization between yeast and higher eukaryotes translates into similarities in their fundamental cellular processes, so that discoveries made in yeasts often provide direct or indirect clues as to how biological processes work in Humans.
On the other hand, unicellular fungi replicate rapidly and are simple to handle genetically. There are also well-defined genetic maps and methods for yeast that gave researchers their first view of the genome and its organization, and were the culmination of genetic studies dating back to the first half of the 20th century.
In fact, thanks to the fact that the yeast gene is similar in the DNA sequence to a human gene, the information scientists have obtained in their studies have provided powerful clues about the role of these genes in humans.
It is believed that yeast has been used as an industrial microorganism for thousands of years and that ancient Egyptians used their fermentation to lift bread.
There are grinding stones, baking chambers and drawings of what are thought to be bakeries dating back thousands of years, and even archaeological excavations have uncovered so-called jars with traces of wine.
According to history, these unicellular fungi were first visualized high quality lenses around the year 1680 by Antoni van Leeuwenhoek.
However, he thought that these globules were starch particles from the grain used to make the must (the liquid extract used in brewing), rather than yeast cells for fermentation.
Later, in 1789, a French chemist named Antoine Lavoisier, contributed to the understanding of the basic chemical reactions necessary to produce alcohol from sugar cane.
This was done by estimating the proportion of materials and starting materials (ethanol and carbon dioxide) after adding yeast paste. However, at that time it was thought that the yeast was simply there to initiate the reaction rather than being fundamental throughout the process.
In 1815, the French chemist, Joseph-Louis Gay-Lussac, developed methods to keep grape juice in an unfermented state and discovered that the introduction of yeast (containing yeast) was necessary to convert unfermented must, demonstrating the Importance of yeast for alcoholic fermentation.
Then, Charles Cagniard de la Tour in 1835, used a microscope with more power to prove that the yeasts were unicellular organisms and multiplied by sprouting.
By the 1850s Louis Pasteur discovered that fermented beverages resulted from the conversion of glucose into ethanol by yeast and defined fermentation as"breathless".
In order to detect zimasa, Eduard Buchner near the late 1800s, used cell-free extracts obtained by grinding yeast, the collection of enzymes that promote or catalyze fermentation. He was awarded the Nobel Prize in 1907 for this research.
Between 1933 and 1961, Ojvind Winge known as"the father of genetics of yeast", together with his colleague Otto Laustsen devised techniques to micro-manipulate the yeast and thus to be able to investigate genetically.
Since then many other scientists have carried out innovative research and some of them have been awarded the Nobel Prize for their significant discoveries, among them: Dr. Leland Hartwell (2001); Dr. Roger Kornberg (2006); Doctors Elizabeth Blackburn, Carol Greider and Jack Szostak (2009), and more recently Doctors Randy Schekman, James Rothman and Thomas Südhof (2013) and Dr. Yoshinori Ohsumi (2016).
- The Editors of Encyclopædia Britannica (2017). Yeast. Encyclopædia Britannica, Inc. Retrieved from: global.britannica.com.
- Kate G. (2015). Unicellular or multicellular? Fun with fungus. Retrieved from: funwithfungus.weebly.com.
- Wikipedia's Editors (2017). Unicellular organism. Wikipedia, the free encyclopedia. Retrieved from: en.wikipedia.org
- Reference Staff (2016). What are single-celled fungi? Reference. Retrieved from: reference.com.
- Barry Starr (2016). Unicellular fungus. Stanford University. Retrieved from: yeastgenome.org.