question_answer 56)

  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:

                  Bioreactors are vessels of large volumes (100-1000 L) in which raw materials are biologically converted into specific products. The most commonly used bioreactors are of stirring type, which are shown in figure.     A stirred-tank reactor is usually cylindrical or with a curved base to facilitate the mixing of there actor contents. The stirrer facilitates even mixing and oxygen availability throughout the bioreactor. Alternatively air can be bubbled through the reactor. If you look at the figure closely you will see that the bioreactor has an agitator system, anoxygen delivery system and a form control system, a temperature control system, pH control system and sampling ports so, that small volumes of the culture can be withdrawn periodically. Small volume cultures are usually employed in laboratories in a flask for research and production of lessquantities of products. However, large scale production of the products is carried out in bioreactors.