Fermenter conditions kept constant?
Reveal answer
Sterile + nutrients + temperature (jacket) + pH + oxygen + stirring.
Key words: sterile
6(a) FOOD PRODUCTION · RECALL
6.8 Industrial fermenters
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Why a water jacket?
Reveal answer
Remove heat from respiration.
Key words: heat
What is meant by the term fermenter?
Reveal answer
A large vessel in which microorganisms are grown under controlled conditions.
Key words: fermenter
What is meant by the term aseptic?
Reveal answer
Free from contaminating microorganisms.
Key words: aseptic
What is meant by the term agitation?
Reveal answer
Stirring the contents of a fermenter.
Key words: agitation
What is meant by the term water jacket?
Reveal answer
A surrounding layer of circulating water that removes heat from the fermenter.
Key words: water jacket
Conditions in an industrial fermenter, Aseptic. How it is achieved? Why it is needed?
Reveal answer
How it is achieved: Steam sterilisation; filtered air. Why it is needed: Prevents contamination and competition.
Key words: Aseptic
Conditions in an industrial fermenter, Nutrients. How it is achieved? Why it is needed?
Reveal answer
How it is achieved: Glucose, nitrogen source, minerals. Why it is needed: For respiration, growth and product.
Key words: Nutrients
Conditions in an industrial fermenter, Optimum temperature. How it is achieved? Why it is needed?
Reveal answer
How it is achieved: Water jacket; temperature probe. Why it is needed: Enzymes work best; heat from respiration removed.
Key words: Optimum temperature
Conditions in an industrial fermenter, Optimum pH. How it is achieved? Why it is needed?
Reveal answer
How it is achieved: pH probe; acid or alkali added. Why it is needed: Enzymes work best.
Key words: Optimum pH
Conditions in an industrial fermenter, Oxygenation. How it is achieved? Why it is needed?
Reveal answer
How it is achieved: Sterile air pumped in. Why it is needed: Aerobic respiration for growth.
Key words: Oxygenation
Conditions in an industrial fermenter, Agitation. How it is achieved? Why it is needed?
Reveal answer
How it is achieved: Motorised stirrer paddles. Why it is needed: Even mixing of nutrients, oxygen and heat.
Key words: Agitation
True or false, and why? “The water jacket heats the fermenter.”
Reveal answer
False. It mainly cools it, because microbial respiration releases heat.
True or false, and why? “Stirring is only needed to mix the nutrients.”
Reveal answer
False. It also distributes oxygen and heat and keeps microbes suspended.
True or false, and why? “Aseptic conditions protect workers.”
Reveal answer
False. Their main purpose is to keep unwanted microbes out of the culture.