ATP (Adenosine triphosphate)
Japanese: ATP（アデノシン三リン酸）
The energy 'currency' used by all living organisms. The ultimate purpose of microbial fermentation is to acquire this molecule.
ATP is the molecule all living organisms use for energy transactions. At its core, the reason microorganisms ferment is 'to make ATP.'
Alcoholic fermentation produces 2 ATP molecules per glucose molecule. Compared to aerobic respiration's 38 ATP, fermentation is energy-inefficient. Yet for yeast, the ability to survive without oxygen represents a crucial survival strategy.
That ATP degradation produces inosinic acid (an umami substance) is also significant in the food context. Katsuobushi's umami is an ATP breakdown product—energy molecules and umami are connected at the molecular level. Life's energy currency also leads to gustatory pleasure—one of fermentation's fascinating dimensions.