Question

Draw a neat-labelled diagram of simply stirred tank bioreactor.

Answer 1

Hint: The fermenter or bioreactor is a large vessel to grow and culture microorganisms like yeast, bacteria, and other desired microorganisms on large scale under aseptic conditions and suitable growth conditions to obtain large amounts of industrially important products like hormones, beverages, antibiotics etc.

Complete answer:
Let us explain parts of a general bioreactor or a fermenter one by one-
• The entire body of a bioreactor is called a vessel and it is made of either steel or glass.
• Agitator/ impeller- this is a device used for proper mixing of gases and medium inside a bioreactor. It also allows proper mixing of nutrients, gases, and oxygen in a bioreactor. Used for both aeration and agitation.
• Sparger- spargers are thin perforated pipes, used to supply proper oxygen to the medium. Used for proper aeration of the medium.
• Heating and cooling jacket- used for passage of cool or hot water and steam to maintain proper temperature inside a bioreactor.
• Baffles- baffles are installed for enhancing proper aeration efficiency of a bioreactor.
• Shaft- Shaft is a long rod to which impellers are attached. In other words, the shaft provides support to the impellers.
• Temperature and pH probes- used in the bioreactor to monitor suitable temperature and pH inside the bioreactor.
• Foam controller- substances to minimise or prevent foam formation inside a bioreactor so that it does not interfere with the culture conditions. E.g. pine oil
• Pressure control- used to control the pressure inside the reactor. Too high or low pressure is not suitable for culture.
• Inlets and outlets- for delivering and removing steam, nutrients etc.

Note: Fermenter or bioreactor is mainly equipped in biotechnological industries to grow microbes for the production of industrially important microorganisms. The microorganisms produce various products utilizing fermentation. Proper and suitable conditions of temperature, pressure, oxygen, and pH are maintained for the proper culture of microorganisms. Sometimes, fermenters used for culturing only animal cells are called bioreactors.