Batch & Continuous Fermentation (OCR A Level Biology): Revision Note

Batch & Continuous Fermentation

• Microorganisms can be grown under controlled conditions in larger fermenters

• The product of fermentation is either the microorganisms itself e.g. mycoprotein, or a product produced by the microorganism e.g. insulin

• There are two main methods used to culture microorganisms by fermentation:

  • Batch fermentation

    • Microorganisms are grown in batches in the fermentation vessel

    • Once the culture cycle is complete, the product is removed, the fermenter is cleaned and a new batch of microorganisms is grown

    • This is known as a closed culture

  • Continuous fermentation

    • Microorganisms are continually grown and the products harvested

    • Nutrients are added and waste is removed throughout the culturing process

Maintaining optimum conditions in the fermenter

• In order to maximise growth and productivity of the microorganisms, the fermenter must be carefully monitored and controlled to ensure conditions are optimum

Optimum Conditions for Fermentation Table

A fermenter is carefully monitored and controlled to ensure optimum conditions for growth of microorganisms. This will maximise yield of the required product