Question

The biomass concentration is at the highest level in which phase?

• A. Lag phase
• B. Log phase
• C. Exponential phase
• D. Stationary phase

Hint:

The stationary phase represents a point where microbial growth stabilizes, and the concentration of biomass is at its peak before the system moves into a decline phase.

Answer 1

The Correct Option is D

The biomass concentration is at its highest during the stationary phase. This phase occurs after the exponential growth phase when the cells have grown to their maximum population. During the stationary phase, the rate of cell division is balanced by the rate of cell death, leading to a stable population size.

(1) Stationary Phase:
- In this phase, the available nutrients become limited, and waste products accumulate, which causes the growth rate to slow down. Despite this, the overall biomass concentration remains the highest because cells have reached their maximum viable density.

(2) Why Other Options Are Incorrect:
- Lag phase (Option 1) is the phase where cells are adapting to their environment, and no significant growth occurs. Biomass concentration is low during this phase.
- Log phase (Option 2) and Exponential phase (Option 3) are characterized by rapid cell division and growth, but the biomass concentration continues to increase as cells grow and multiply, but the highest concentration is reached just before the stationary phase, when the growth rate begins to plateau.

Conclusion: The biomass concentration is at the highest level in the stationary phase, where growth and death rates balance out, and the population stabilizes.