The Growth of Microorganisms

 The growth of microorganisms is divided into several phases as follows:  

1. Lag Phase  

In this phase, microorganisms adjust themselves to the new environment. Further growth can occur because various enzymes and intermediate substances are formed in this phase.  

2. Accelerated Growth Phase  

In this phase microorganisms begin to divide, but the generation time is still long. The lag phase and the accelerated growth phase are often collectively referred to as the lag phase.  

3. Logarithmic Growth Phase  

In this phase, the growth rate is fastest and the generation time is short and constant. Cell material synthesis is very rapid and constant. This condition continues until one or several nutrients are depleted or until toxic metabolic byproducts accumulate, thereby inhibiting microorganism growth.  

4. Decelerating Growth Phase  

In this phase, microorganism growth begins to be inhibited because required nutrients have decreased or toxic metabolic substances have accumulated.  

5. Stationary Phase or Constant Phase  

In this phase, microorganism growth is inhibited and a decline occurs because required nutrients have decreased or toxic metabolic substances have accumulated, causing the number of dead and living microorganisms to be equal.  

6. Accelerated Death Phase or Logarithmic Death Phase  

These two phases are often called the death decline phase. In this phase the division rate becomes zero while the death rate continues to increase. If this condition reaches the logarithmic death phase, the death rate becomes maximum.