Cambridge O Level Biology · Syllabus 5090 · Biotechnology and Genetic Modification
Cooling jacket
What is Cooling jacket?
An outer water jacket surrounding an industrial fermenter, used to remove excess heat from the culture. Microorganisms release thermal energy as they respire, and in a large vessel containing an enormous number of cells this heat would raise the temperature far above the optimum, denaturing enzymes and killing cells. Cold water is circulated through the jacket and leaves warmer, carrying the excess heat away, while a temperature probe monitors the culture so the cooling can be adjusted. A large fermenter therefore needs cooling rather than heating, which is the opposite of most students' expectation.
This definition is part of the Biotechnology and Genetic Modification chapter in Cambridge O Level Biology.
Common mistakes with Cooling jacket
- “Fermenters should be kept as hot as possible.” Why wrong Above the optimum, enzymes denature and cells die. And a large fermenter is already overheating from the heat its own microorganisms release. Say instead The culture is held near a suitable temperature, and cold water in the cooling jacket removes the excess heat produced by respiration.