Symbiosis
Japanese: 共生
The close living relationship between different species. Includes mutualism, commensalism, and parasitism, and is a key concept for understanding microbial ecosystems in fermented foods.
Symbiosis is the relationship in which different species live while influencing each other. In fermented foods, multiple microorganisms frequently build symbiotic relationships.
Take kombucha's SCOBY, for example. Yeast produces alcohol from sugar, and acetic acid bacteria convert that alcohol into acetic acid. Each utilizes the other's product—a splendid mutualism.
In miso fermentation too, lactic acid bacteria and yeast utilize the sugars and amino acids produced by koji mold. No single microbe could achieve this alone. The relay between different microorganisms is the key to creating complex flavors. An important concept bridging theory and practice.