Question

One of the main differences between a simple stirred-tank bioreactor and a sparged stirred-tank bioreactor is that:

• A. a simple stirred-tank bioreactor has more surface area for oxygen transfer compared to the sparged stirred-tank bioreactor
  
• B. a sparged stirred-tank bioreactor has more surface area for oxygen transfer than simple stirred-tank bioreactor
• C. the desired product is obtained in small volumes in a simple stirred-tank bioreactor and in large quantities in a sparged stirred-tank bioreactor
• D. both b and c are correct

Answer 1

The correct option is B a sparged stirred-tank bioreactor has more surface area for oxygen transfer than simple stirred-tank bioreactor

Bioreactors are large vessels that are used for large scale culturing of cells to obtain specific gene products for commercial use. In bioreactors, large volumes (100-1000 litres) of culture can be processed to obtain large quantities of the desired product.

A bioreactor provides optimum growth conditions, such as, temperature, pH, nutrients, oxygen (in aerobic bioreactors), etc, for the growth of cells in order to achieve the desired gene product. The most commonly used aerobic bioreactors are stirred type bioreactors which are again of two types, simple and sparged type.

In a sparged tank bioreactor sterile air is bubbled through the culture medium with the help of a sparger which is not done in simple stirred-tank bioreactors. The bubbles in the sparged tank bioreactor increase the surface area for oxygen transfer into the culture vessel.