yeasts

Fig. 1: Cover of the Yeast journal, volume 38. 

Steenwyk, J.L. (2021), Cover Image: A portrait of budding yeasts: A symbol of the arts, sciences and a whole greater than the sum of its parts. Yeast, 38: i-i. https://doi.org/10.1002/yea.3551 

A Model for Understanding and Production 

January 2023

Saccharomyces cerevisiae, also known as beer yeast, is a very valuable study model for the scientific community. This yeast is easy to cultivate and manipulate in the laboratory, making it an ideal tool for investigating different biological processes, including the response to external stimuli, the regulation of metabolism, and cellular function. Furthermore, unlike many other organisms, S. cerevisiae can be genetically modified to study the effect of specific changes on its biology. 

Scientists worldwide share their findings using this model in scientific journals (Fig. 1) and organize it in databases such as the Saccharomyces Genome Database (SGD) (Fig 2.). This makes it possible to advance faster in the pursuit of knowledge and not repeat experiments that others have already done, but rather use their discoveries to find answers to new questions. 

In addition to being easy to work with, S. cerevisiae also has a genetic and cellular system similar to that of more complex organisms, including humans. Therefore, studies carried out on this yeast can have important implications for the understanding of human biology and the search for treatments for diseases. One of the most outstanding examples is the work of Dr. Yoshinori Ohsumi who won the 2016 Nobel Prize in Physiology or Medicine for his groundbreaking research on autophagy, a cellular process where cells recycle their worn-out components or consume less essential parts of themselves to survive during starvation. He used Saccharomyces cerevisiae as a model organism. This research has numerous medical applications, including chemotherapy resistance, amyloid-β aggregation in Alzheimer's disease, and mitophagy in Parkinson's disease. 

Fig. 2 Saccharomyces Genome Database (SGD)
Cherry JM, Hong EL, Amundsen C, Balakrishnan R, Binkley G, Chan ET, Christie KR, Costanzo MC, Dwight SS, Engel SR, Fisk DG, Hirschman JE, Hitz BC, Karra K, Krieger CJ, Miyasato SR, Nash RS, Park J, Skrzypek MS, Simison M, Weng S, Wong ED (2012) Saccharomyces Genome Database: the genomics resource of budding yeast. Nucleic Acids Res. Jan;40(Database issue):D700-5. [PMID: 22110037] 

Other recent Nobel Prizes have been awarded for work in yeast, including the 2001 Nobel Prize in Physiology or Medicine to Leland H. Hartwell, R. Timothy Hunt, and Paul M. Nurse for their discoveries of "key regulators of the cell cycle," the 2006 Nobel Prize in Chemistry to Roger D. Kornberg for his studies of the molecular basis of eukaryotic transcription, the 2009 Nobel Prize in Physiology or Medicine to Elizabeth H. Blackburn, Carol W. Greider, and Jack W. Szostak for the discovery of how chromosomes are protected by telomeres and the enzyme telomerase, and the 2013 Nobel Prize in Physiology or Medicine to James E. Rothman, Randy W. Schekman, and Thomas C. Südhof for their discoveries of machinery regulating vesicle traffic in cells. 

Brewer's yeast is also relevant to the food and Biotechnology industries. For example, S. cerevisiae plays an important role in the production of bread, beer, and wine, and can be used to produce recombinant proteins for the pharmaceutical industry, biofuels such as ethanol, or precursors for the synthesis of chemical products such as succinic acid using plants as raw materials.

Some companies that currently use this yeast are shown in figure 3, A, and the Bioamber plant, which has been in operation for over 7 years in Canada, is presented in figure 3, B.

In summary, S. cerevisiae is a valuable scientific model due to its ease of culture and manipulation, its genetic and cellular system similar to humans, and its relevance to the food industry and biotechnology.

In Figure 3, the top (A) shows four of the largest biotechnology companies that use S. cerevisiae to produce proteins, chemicals, or fuels. The bottom (B) shows the Bioamber plant in Sarnia, Ontario. 

Furthermore, studies conducted on this yeast have contributed to many important advances in the understanding of molecular and cellular biology. Therefore, it is an essential tool for the scientific community in its search for a better understanding of the world around us.