Question

Illustrate the design of a bioreactor. Highlight the difference between a flask in your laboratory and a bioreactor which allows cells to grow in a continuous culture system.

Answer 1

Small volume cultures cannot yield appreciable quantities of products. To produce in large quantities, the development of bioreactors, where large volumes (100-1000 litres) of culture can be processed, was required. Thus, bioreactors can be thought of as vessels in which raw materials are biologically converted into specific products, individual enzymes, etc., using microbial plant, animal or human cells. A bioreactor provides the optimal conditions for achieving the desired product by providing optimum growth conditions (temperature, pH, substrate”, salts, vitamins, oxygen). 

Simple stirred-tank bioreactor

Sparged stirred-tank bioreactor through which sterile air bubbles are sparged

Flask	Bioreactor
Flask is used for small laboratory scale testing of a culture.	Bioreactor is used for commercial production
The cells harbouring cloned genes of interest may be grown on a small scale in the laboratory.	The cells can also be multiplied in a continuous culture system wherein the used medium is drained out from one side while the fresh medium is added from the other to maintain the cells in their physiologically most active log/exponential phase. This type of culturing method produces larger biomass leading to higher yields of desired protein.