Some of the most important developments in human history came about all thanks to microscopic unicellular organisms. This may be hard to believe with our macroscopic view, but upon further investigation, an entirely new world opens up. I know that biochemistry might not be the most interesting topic to learn about, but exploring the life-saving power of fermentation can be fascinating. Understanding life on a microscopic scale can put the world in perspective, and deepen the understanding of how humanity interacts with its environment.

To begin, it’s crucial to understand the basics of the fermentation process. Fermentation takes place when a microorganism metabolizes nutrients, (usually carbohydrates) and produces a new substance as a byproduct of its sustenance. 

The process of fermentation is ubiquitous throughout the natural world. While fermentation absolutely occurs without human intervention, humans have managed to utilize the natural process of fermentation for our benefit.

For centuries fermentation has been used to create ethanol, better known as the alcohol found in beverages such as beer, wine, and spirits. While this is likely the most commonly known application of fermentation, it is far from the most history-defining. That prize goes to the cultivation of lactic acid producing bacteria. 

 Over quarantine, I’m sure you were bombarded by sourdough bakers showing off their bread. Fermentation is absolutely essential to the baking of sourdough bread. With the introduction of commercial yeasts to supermarkets worldwide, sourdough baking has become a luxury reserved for those with excess time. However, for most of human history sourdough was the only way to make leavened bread. The sourness of the bread, created by lactic acid producing bacteria, is not only for culinary purposes but also serves to lengthen its shelf life. The lactic acid found in sourdough creates an acidic environment, while the bacteria themselves have antifungal properties.

While at first, sourdough may not seem exceptionally significant in the course of human history, upon further inspection its creation was a pivotal innovation for ancient humans. The most obvious benefit of sourdough is that it provided a shelf-stable use for grains. Early humans managed to master the cultivation of wheat and other grains, but the grains tended to go bad quickly. By grinding down grains into flour, and making bread with them, humans made a calorically dense, shelf-stable food source. The stability, coupled with its caloric density, aided early humans in their physically demanding lifestyle.

But there are still more applications of fermentation, with life-saving implications.

Prior to 1922, diabetes was considered a death sentence. In present times, a treatment plan is laid out, and the patient is put on lifelong regimented insulin doses. While initially insulin was extracted from the pancreas of animals, it became clear that a more viable method for insulin cultivation was needed.

In contemporary times, insulin is produced through the fermentation process. DNA capable of insulin production is taken from a human cell and is then added to the microorganism’s DNA. Many different species are used, but the most commonly used are E. coli (a bacterium) and Saccharomyces cerevisiae (a yeast).

If the name E. coli sounds familiar, it’s because certain strains of E. coli are a common culprit in cases of food contamination. However, E. coli is actually found in a multitude of places including your own intestines! The presence of  E. coli in the intestines aids digestion and prevents infection. 

By harnessing the power of fermentation humanity has created a mutually beneficial, or symbiotic relationship between organisms. The microorganisms benefit from the nourishment manually provided by humans, while humans benefit from the byproducts of the fermentation reaction.

I hope that this piece offered a brief but informative introduction to fermentation. Recognizing the importance of humanity’s interactions with other organisms, no matter the discrepancy in size is a constructive exercise in remembering humanity’s place in the world.