The Art of Fermentation summary

Fermentation. It’s a word you've probably heard, and if you’ve ever eaten bread or cheese or drunk beer, you're familiar with the products of this vital process. But what does fermentation actually mean? To answer that question, we need to go all the way back to the origins of life on our planet. 

All of Earth’s life forms need energy for their cells to create macromolecules, their building blocks. The way a cell obtains this energy is through its metabolism. The very first living organisms, certain kinds of bacteria, had anaerobic metabolisms – that is, they didn’t need oxygen to convert nutrients into energy. Another word for this process? Fermentation. 

As time went on, new kinds of metabolism would develop from these fermenting bacteria, leading to life on Earth as we know it today.

The key message in this blink is: Fermentation transformed our planet. 

As biologists Lynn Margulis and Dorion Sagan put it in their study of microbial evolution, Microcosmos, bacteria actually invented all of life’s essential chemical systems. 

Take our oxygen-rich atmosphere – the precondition for the existence of complex life-forms like animals, plants, and fungi. This was created by fermenting bacteria. 

How did they do it? Well, during the first couple of billion years of life on Earth, these bacteria interacted with one another. It could be a struggle to the death, with one bacterium destroying another. But it could also be a complex, two-way relationship that transformed both bacteria. One product of this second type of interaction was a new kind of metabolism. 

Over time, certain microbes evolved to produce, or photosynthesize, energy from sunlight. The byproduct of this nutritional strategy was oxygen. As the number of these microbes grew, the planet’s atmosphere was oxygenated – and transformed forever. 

At this point, the first aerobic – or oxygen-dependent – cells entered the evolutionary fray. It appears that their relationship with older, anaerobic cells was initially that of predator and prey. Over time, though, these former foes learned to coexist. Aerobic cells took up residence inside anaerobic cells without destroying them – an arrangement that allowed both parties to profit from each other’s metabolisms. 

It was this relationship that paved the way for the emergence of eukaryotes – the complex organisms which, at a cellular level, make up the building blocks of all human, animal, and plant life.