Question

Observe the sketch of stirred-tank bioreactor and label the parts A, B, C and D.
   

Answer 1

Hint: Any manufactured device or system that supports a biologically active environment is termed as a bioreactor. It is a vessel in which a chemical reaction involves organisms or biochemically active chemicals generated from organisms carried out. The process carried out can be either aerobic or anaerobic. Bioreactors are commonly cylindrical in shape, which ranges in size from liters to cubic meters and are often made of stainless steel.

Complete answer:
A – Motor: A motor is used for mixing the contents of the reactor. It keeps the cells or contents in a perfect homogenous condition for the better transport of nutrients and oxygen to the desired product. The motor converts electrical energy to mechanical energy. It produces a rotary force which helps to rotate the impeller.
B – Foam breaker: Foam gets generated in a bioprocess. To control this, foam breakers are used. This mechanical foam breaker breaks down foam that is formed during the course of a bioprocess and helps in smooth functioning of the bioreactor.
C – Flat bladed impeller: The impeller or agitator is the core component of a mixed tank bioreactor. It performs a wide range of functions which includes heat and mass transfer, aeration, and mixing for homogenization. The impeller mixes gas bubbles through the liquid culture medium and microbial cells through the liquid culture medium. It ensures uniform access of microbial cells to the nutrients.
D – Acid/Base for pH control: This is used to control the pH inside the bioreactor medium. Acid or base is added as necessary for pH control.

So, the correct answer is A – Motor, B – Foam breaker, C – Flat bladed impeller, D – Acid/base for pH control.

Note:
A bioreactor can be classified as a batch, fed batch or continuous bioreactor on the basis of mode of operation. The organisms that are growing in bioreactors may be either submerged in a liquid medium or may be attached to the surface of a solid medium. The submerged cultures may be either suspended or immobilized. Since special attachment surfaces are not needed, the suspension bioreactors can use a wider variety of organisms.