Growth curve
Japanese: 増殖曲線（生育曲線）
A graph plotting changes in microbial population over time. It shows a typical pattern of four phases: lag phase, log phase, stationary phase, and death phase.
A growth curve is a graph showing how microbial numbers change over time. The typical pattern consists of four phases.
First is the lag phase, a preparation period where microbes placed in a new environment have not yet begun active growth. Next comes the log phase, where organisms multiply exponentially. Eventually, nutrient depletion and waste accumulation slow growth, entering the stationary phase. Finally, the death phase, where cell death exceeds growth and numbers decline.
Fermented food production proceeds while monitoring which phase the microorganisms are in. In koji-making, temperature rises sharply during the log phase, making ventilation and handling timing critical.
The growth curve is like a map that provides a bird's-eye view of a microorganism's lifetime.