Yeast is essential in the making of bread, beer, and other yummy things that are part of our day to day lives. As yeast feeds on sugar, it produces carbon dioxide and alcohol. The carbon dioxide gas is what causes bread to rise and come out of the oven as a fluffy loaf of deliciousness! Although it probably doesn’t need to be stated, the alcohol portion produces things like beer and wine. These common day to day products are what yeast is best known for; however, yeast is also an extremely valuable biomedical research tool.
Since September, I have been working alongside my fellow Future Science Leader researchers with a variety of yeast. We began the year with a fermentation project and isolated 14 yeast strains from British Columbia’s Okanagan Valley and we are presently working on either independent or partner projects with the same yeast. Yeast aren’t just popular in our mini-lab, they are actually the focus of thousands of researchers worldwide. Yeast fascination begs the question, why do scientists actually spend time and money to do research on yeast? And, why is yeast so practical to work with?
I’ll begin with a little background on yeast. Yeasts are unicellular, eukaryotic (like humans!) microorganisms. As a member of the Fungi kingdom, there are approximately 1500 different species of yeast and many of them have different characteristics. However, all yeasts are super duper tiny; they are usually only 3-4 micrometers in diameter! Luckily for them, they reproduce about every 100 minutes and most do so asexually by mitosis.
Back to the question at hand— What are the benefits of researching yeast?
Some of the yeast I work with!
When compared to bacteria and some other organisms, yeast are actually fairly safe; most yeast can even be handled with few safety measures. Of course, like everything in life, there are a few exceptions but for the most part, yeast do not require any special anti-contamination methods or extraordinary measures to be handled. Generally speaking, this makes yeast a little easier to work with than other “dangerous” organisms. The relative safety of yeast is especially helpful for young researchers, like me, who don’t have lab to work in. It means that I could do my research and experiments in many more places than I ever could if I were working with bacteria.
Yeasts are simpler organisms than humans. This may seem obvious but it is critical in research. Since they are unicellular and lack complex organs and body systems, they are easily to work with than mammalian cells. However, the simplicity of yeast, when compared to human cells, does not mean that they are polar opposites. In fact, yeasts’ similarities to human cells, in combination with their superior simplicity are what make them so great to work with.
Some of the yeast I work with!
If you can think beyond how humans are emotional, multicellular, complex beings, it becomes apparent that yeast and humans share many traits as I eluded to above. On the genetic level, where much research is done, many yeast genes resemble human genes. Amazingly, our DNA is so similar that in some areas, a human gene can be swapped our for the equivalent yeast gene. This means that researchers can do preliminary work on yeast that can be related to humans. In the long run, this saves time,— human cells take about 24 hours to duplicate while yeast cells take a fraction of that at about 2 hours— money, and energy.
Because of the overlapping genes in yeasts and humans, yeasts are a perfect model to work with in research. For example, yeast genes can be removed and replaced with human genes to test drugs and mutagens.
Yeast can also be manipulated in the lab. Researchers can replace a yeast gene with a genetically engineered one and synthetic oligonucleotides can be transformed into yeast to study proteins.
In 1996, the complete genome of yeast was being sequenced, Dr. Francis Collins, director of the National Human Genome Research Institute (NHGRI) at the time, stated “The yeast genome is closer to the human genome than anything completely sequenced so far. The complete sequence will allow us to move into a whole new area of biology — looking at how all the genetic instructions work together to make a whole cell function.” And so it did. Having the entire genome sequenced has meant that yeast have been studied to learn about cellular processes like replication, cell division, and metabolism.
Photo credit: Saccharomyces Genome Database (SGD).
Determining the similarities between humans and yeast has paved the way for hundreds of past and future researchers. The ability and ease of working with yeast has meant that many human diseases, like cancer, can be worked on more extensively in a yeast model. Since yeast has proven to be a great model to work with, research methods have significantly improved and advances in labs have made research even easier.
Concluding, yeast will continue to become more and more useful in research as more research is done on it. Christopher Beam used the snowball effect metaphor in his article on yeast to describe this process. In other words, As the collective body of knowledge surrounding yeast grows, yeast will become even more useful in science. If you take into consideration how much we don’t yet know about human genes, it is evident that models like yeast will continue to be “go-to” research tools for years to come!
You can also see this post on the Future Science Leaders site!
