Question

Explain important features of a stirred tank bioreactor.

Answer 1

A stirred tank reactor is a cylindrical vessel with a curved base that helps in mixing its contents. The stirrer ensures uniform mixing and proper oxygen distribution. Air may also be bubbled in to enhance mixing. The agitation system, consisting of an agitator and baffles, increases turbulence and improves mass transfer efficiency.

The important features of a stirred tank bioreactor are:

1. An agitator system: It ensures a proper distribution of nutrients and microorganisms. It increases oxygen distribution and mass transfer.
2. An oxygen delivery system: It uses a sparger to introduce sterile air or oxygen into the bioreactor. This helps microorganisms with respiration more efficiently.
3. A foam control system: During fermentation, foam may occur due to agitation. Antifoam chemicals are introduced to prevent excessive foaming, which can disrupt the process.
4. Temperature control system: It maintains the optimal temperature for microbial growth. Temperature regulation is achieved through the use of cooling or heating systems.
5. pH control system: It continuously checks and maintains the pH of the medium. Acids or bases are added as needed to maintain pH stability.
6. Sampling ports: These enable the withdrawal of small volumes of culture at regular intervals. Samples are tested to track growth and product development.