Question

What are fermenters?

Answer 1

These are containers used to grow microorganisms on an industrial scale that is in large quantities. For large- scale production, these containers have the capacity of holding thousands of liters of material.

Correct step by step answer:
A fermenter is an enclosed and sterilized vessel or an apparatus that maintains optimal conditions for the growth of microorganisms such as bacteria and fungi and used for the fermentation of microorganisms to be produced in large quantities for commercial use. The product is collected after the completion of the fermentation process or activity.

Additional Information:
After the completion of fermentation activity the product can be collected from a fermenter:
- After a fixed amount of time referred to as batch cultivation. Here, the microorganism undergoes all the stages of growth in a fixed period before the product is collected.
- Ongoing is referred to as continuous cultivation. Here, the peak rate of the growth of microorganisms is maintained. This is also known as the exponential phase.
Structure of a fermenter:
- To maintain an optimal level of microbial growth in the fermenter sensors and probes are used to monitor conditions within the fermenter.
- A large stainless steel cylindrical container is used in which motorized stirring paddles are present to evenly distribute heat and materials within the reaction chamber.
- the whole container is kept in an external water jacket. This jacket is used to absorb excess heat and maintain the desired temperature.
- in the container there presents an aerator to introduce compressed air into the chamber and also a defoamer is present to stop the formation of foam in the container.
- To regulate the pH level within the chamber an acid- base inlet is also present.
- The top of the container also contains a nutrient inlet and an exhaust outlet.through the nutrient inlets sugar is introduced into the container and through the exhaust outlet, metabolic wastes are removed.
- Between batch cultivation and continuous cultivation the necessary adjustments required for continued growth may differ.
- To prevent contamination of the organisms in both the cases the condition within the fermenter must remain aseptic. eg Penicillium mold for producing penicillin (an antibiotic).

Note:
- Fermenters are usually made from a metal that will not corrode when exposed to natural atmospheric conditions, such as stainless steel.
- Based on the type of product and the volume of the product to be produced the fermenters are of different types.
- Some common types of fermentors are tower fermenter, bubble column, air- lift, fluid bed fermenter, etc. having different uses.