Question

3. Using a diagram show the growth curve for a bacterial organism grown in batch culture. Label the various phases and describe what is happening in each phase. How can we juggle the conditions to create a continuous culture as in a situation where we want a continuous supply of a bioproduct.

Answer 1

There are four phase of growth curve in batch culture.

1) Lag plase :- When an inoculum is inocelated in fresh media, bacterial cell take time to adapt, replicate DNA, protein sysnthesis and RNA synthesis (which is essential for growth). So, no net increase in cell number results in log phase.

2) Exponential or log phase :- When an appropriate or optimum enzyme for growth are expressed then cell divided exponentially means 2-4, 4-8, 8-16, 16-32, and so on.

3) Stationary Phase :- There is eventually the growth ceases, this might be due to number of cell dividing equals number of death or deficiency of nutrient or accumulation of waste product.

4) Death or log decline phase :- In this phase due to lack of nutrient, there is exponential decline in cell number.