Different cells have different needs.
Some are aerobic – they need oxygen – while
others are anaerobic and don’t need oxygen.
But the lifecycle of almost all cells follows
a predictable 4 phase-pattern.
Lag, Exponential, Stationary and Death.
When a cell is first introduced to fresh growth
media, it has to adapt to the new environment.
This creates a lag in the growth timeline.
After the organism adapts, the batch takes
off.
The cells begin dividing at a constant rate
–an Exponential or Logarithmic increase.
But eventually, the nutrients in the media
are consumed, toxic metabolic waste products
build up, cells begin to die, and growth slows.
When just as many cells are dying as are dividing,
the batch enters the Stationary phase.
This is the point at which the key nutrients
are completely consumed, the fermentation
is stopped and the broth is harvested.
If the fermentation were allowed to continue,
the cells would enter the Death phase.
