Yeast is a key element in various industries, including the production of industrial ethanol, baking, and the fermentation of beverages. But do you know the specificities of this microorganism?
Understanding its characteristics and functions helps appreciate how it has been a cornerstone of production processes for centuries. Let’s explore the fascinating world of yeast, its biological makeup, and why Saccharomyces cerevisiae stands out.
What is yeast?
Yeast is a unicellular fungus.
Yeast belongs to the fungal kingdom, a large and diverse group of eukaryotic organisms. Eukaryotic cells possess organelles that divide the cell space into specialized compartments. The nucleus, for example, contains their genetic heritage (DNA). Fungi are heterotrophic in nature, they feed on existing organic constituents to synthesize the components they need.
Fungi can be categorized into three major groups:
- macroscopic filamentous fungi– whose fruiting body is called mushroom
- microscopic multicellular filamentous fungi– commonly referred to as molds
- microscopic unicellular organisms– yeasts are part of this group, characterized by their single-cell structure
While yeast may be invisible to the naked eye, these microscopic powerhouses play a crucial role in countless natural and industrial processes.
Saccharomyces cerevisiae: the most popular yeast species
Did you know that there are several thousand yeast species? They are incredibly diverse, with the number of yeasts discovered constantly increasing. In 2005, only 2,500 species were identified out of the 150,000 that the Earth could host[1].
Among this great diversity, the species most used for bioethanol production is certainly Saccharomyces cerevisiae. Its name is a combination of Greek and Latin: in Greek, Saccharo means sugar, myces means fungus and cerevisiae is derived from a Latin word meaning “of beer”.
True to its name, S. cerevisiae has been used since antiquity in the production of alcoholic beverages – like beer and wine – thanks to its:
- High ethanol productivity – it efficiently converts sugar into ethanol
- High tolerance to ethanol – it can thrive in environments with elevated ethanol concentrations that would inhibit other organisms
- Ability to ferment a wide range of sugars
Yeasts are now used in many industrial applications to produce a wide variety of food, feed and industrial products. One of the most common applications is in the bakery industry, where its fermenting capacity is used to leaven the dough. Moreover, its biochemical composition makes it an interesting product for nutrition applications. Indeed, Saccharomyces cerevisiae is rich in vitamins and minerals, which, when ingested by a living being, whether human, animal, or vegetable, contribute to the proper functioning of its organism.
Finally, as a eukaryote, its cellular mechanisms are very similar to human cells. Thus, over the years, S. cerevisiae has become a model microorganism in molecular and cellular biology for studying biochemical reactions in the cell.
A sustainable powerhouse
Thanks to its versatility and efficiency, yeast plays a key role in the development of sustainable solutions, like for the production of bioethanol, reducing the reliance on fossil fuels. Additionally, yeast’s unique characteristics make it a promising player in the development of bio-based materials, chemicals, and so on.
Yeast may be small, but its impact on industries and everyday life is enormous. From leavened bread to bioethanol, this unicellular fungus continues to shape how we live and produce goods. Among the manies species, S. cerevisiae stands out as a true powerhouse, driving innovation in science and energy.
As we continue to explore the natural world, yeast reminds us of how even the tiniest organisms can have outsized importance for an ever-evolving future.
