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Learn0610Papers 1, 3 · CoreBiotechnology and genetic modificationBiotechnology and fermenters
Biotechnology and genetic modification · Subtopic 1 of 2

Biotechnology and Fermenters

Biotechnology uses living organisms to make useful products. Microorganisms are ideal: they reproduce rapidly, need simple nutrients, and can make complex molecules. Yeast makes ethanol for biofuel and CO₂ to make bread rise. Bacteria make yoghurt (Lactobacillus turns lactose into lactic acid). Enzymes from microbes are used in biological washing powders, pectinase for clearer fruit juice and lactase for lactose-free milk. Industrial fermenters grow microbes in controlled conditions: temperature, pH, oxygen, nutrients, and stirring, kept sterile; penicillin is made this way.

Cambridge 5090 Paper 1Cambridge 5090 Paper 2Cambridge 0610 Papers 2, 4Cambridge 0610 Papers 1, 3Edexcel 4BI1 Paper 1BEdexcel 4BI1 Paper 2B≈ 35 minRevision 1 · updated 2026-10-30
Section 1 of 14

Learning objectives

  • Explain why microorganisms are used in biotechnology.
  • Describe uses of yeast, bacteria and enzymes.
  • Describe an industrial fermenter and explain the conditions controlled.
Pause and think

Why do brewers keep their fermenting tanks sealed from the air?

Section 2 of 14

Core idea

Start hereTiny factories

Bread, cheese, yoghurt, antibiotics and insulin all depend on microorganisms working for us, often in tanks the size of houses.

The big idea

Microbes grow fast and make useful substances. Fermenters keep conditions at their optimum so production is maximised.

1. The fermenter

Industrial fermenter

Each control keeps the microbes at their best.

Worked exampleWhy each condition matters

A penicillin fermenter.

Goal
Justify three controls.
Strategy
Link to enzymes and growth.
  1. temperature\text{temperature}
    Optimum for enzymes; respiration releases heat that must be removed.
  2. oxygen\text{oxygen}
    Penicillium respires aerobically.
  3. sterile\text{sterile}
    Contaminating microbes would compete or spoil the product.
AnswerConditions keep growth and production high.
✓ CheckPenicillin is made after the main growth phase ✓.
Key takeawayEnzymes from microbes Pectinase (juice), lactase (lactose-free milk), proteases and lipases (washing powder).
Pause and think

Why does biological washing powder save energy?

Summary

  • Microbes: fast, simple needs.
  • Yeast, bacteria, enzymes.
  • Fermenters control conditions.
Key words
Biotechnology
Using living organisms to make products.
Fermenter
Vessel for growing microorganisms on a large scale.
Aseptic
Free from contaminating microorganisms.
HistoryMass-producing penicillin. During World War II, scientists in the US found a strain of Penicillium on a mouldy cantaloupe that produced far more penicillin, enabling mass production by 1944.
Fun factQuorn. Mycoprotein, sold as Quorn, is made by growing the fungus Fusarium in 40-metre-tall fermenters.
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