Question

Explain the growth curve of microorganism and the factors involved in each phase. ​

Answer 1

Let's discuss the growth curve of bacteria:-

- It has four distinct phases.

(1) Lag phase

Whwn a microorganism is introduced into the fresh mexium , it takes time to adjust in the new environment. This phase is termed as lag phase. In lag phase cellular metabolism is accelereted. Celle increase in size but the bacteria are not able to replicate. So there is no increase in cell mass. The length of the lag phase depend on previous growth conditions of the organism.

(2)Log phase:-

It is also called as logarithmic or exponential phase. Their metabolic activity increases and the organism begin the DNA replication by binary fission at a constant rate. The number of bacteria increases logarithmically.

(3) as the bacteria population grows , all the nutrients in the growth medium are used up by the organism. Thus accumulation of waste materials , toxic substances in the medium occurs. This change the pH and temperature of the medium, therefore create the unfavorable environment for the bacteria to grow. The cell undergoing division is equal to the number of cell death and finally bacteria stops its division completely.

(4) Decline phase.

During this phase the becteria completely lose its ability to reproduce. Individual bacteria begin to die due to the umfavounfav condition and the rate of death remain uniform.

Hopefully it helps thanks