Question

Which parameter is most commonly controlled in a bioreactor?

• A. Light intensity
• B. pH
• C. Pressure
• D. Sound

Hint:

Temperature and pH are the "fundamental two" parameters. Dissolved Oxygen (DO) is the third most critical for aerobic processes.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
A bioreactor provides a controlled environment for the growth of cells or microorganisms. Maintaining optimal physicochemical conditions is vital for cell health and product formation.
Step 2: Detailed Explanation:
The **pH** is one of the most critical parameters monitored and controlled in almost all industrial fermentations.
As microorganisms grow, they consume nutrients and release metabolic by-products (like organic acids), which can significantly shift the pH of the medium.
If the pH deviates from the optimum, enzyme activity inside the cells can drop, leading to decreased growth or cell death.
Bioreactors use automated systems to add acid or base to keep the pH at a specific set point.
- Light intensity (Option A) is only controlled for photobioreactors (e.g., algae).
- Pressure (Option C) is monitored but not as dynamically controlled for biological optimization as pH.
Step 3: Final Answer:
Among the given options, pH is the most universally controlled parameter in bioreactor operations.