Key Words to define:
Autotroph
Heterotroph
Selective breeding -
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Artificial selection -
Fertlisers -
Mycoprotein
Food spoilage
Pasteurisation
Irradiation
Sterilisation
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Ancient Biotechnology
~50,000 years ago - at least two different species of
“people” (H.sapiens,
H. neanderthalensis) began to pass on cultural traditions. People could “imagine”, share ideas, plan ahead, honor their dead.
They began to see the world as something that could be manipulated.
10,000 years ago - the traditions of agriculture and animal husbandry began to develop.
Wheat, rye, barley, goats, sheep

Early Agriculture
Even relatively primitive peoples understood that selective breeding had positive outcomes.
-larger grain seeds
 flour
-selective breeding of goats and eventually cattle to increase milk production and meat content.
Agrarian societies unknowingly participated in genetic manipulation to make useful products for humans.
SELECTIVE BREEDING IS BIOTECHNOLOGY

Modern Example of Selective Breeding
Selective Breeding of Kale
( Brassica oleracea )
Cabbage
Brussels Sprouts
Cauliflower
Kohlrabi
Kale

This is modern Kale. Its ancestor provided the stock for the selective breeding of the other subspecies.

The large terminal buds of the plant were selected to produce cabbage.

Large lateral buds were selected to produce
Brussels Sprouts

• Breeders choose features they wish to improve.
• Individuals with those features are bred together.
• Offspring with improvement are selected to breed in next generation.
• Continues over next 10+ years

Cauliflower was produced by selecting for large, white flower stalks.

For broccoli, large stems and flower stalks were both selected.

Kohlrabi was produced by selecting for short, fat stems

And this is modern Kale.
Remember, all of the vegetables that you have seen are the SAME
SPECIES - EACH
PRODUCED BY
SELECTIVE BREEDING; TAKING
ADVANTAGE OF WILD TYPE GENES
AND NATURAL MUTATIONS.

Coming to a supermarket near you soon…

• Yields of grain (wheat, rice), roots (carrots) and tubers (potatoes)
• Pest resistance – insects, fungi, bacteria, viruses
• Better quality – appearance, taste

• Yield of meat, milk, eggs
• Fast growing breeds
• Disease resistance ( eg blue tongue disease)
• Quality – lean, low fat meat

All the same species
– Ovis aries

• Nitrates – making amino acids
• Phosphates – DNA, RNA, ATP, phospholipids
• Potassium – enzyme co-factor; guard cell opening
• Magnesium – making chlorophyll

• Inorganic:
• Higher yield, cheaper, trace contaminants
• Organic;
• Lower yields, more expensive, no trace contaminants

• Herbicides – kill weeds that compete
• Fungicides – against mildew, blight and rust
• Insecticides – applied when levels threaten economic loss.
• Organic – use none of the above.
• Crop rotation and natural predators
(biological control)

Use of Microorganisms
Bacteria cheese, yogurt, antibiotics
Fungi cheeses
Yeast ( single celled fungus) bread, beer
C
6
H
12
O
6

CO
2
+ C
2
H
5
OH
Louis Pasteur (1860’s) clearly demonstrated that microbes are responsible for fermentation.

Produce traditional products in clever, new ways
-increase crop productivity, meat production, and milk production
“The miracle of Genetic Engineering”

Mycoprotein
Uses a fungus Fusarium ( strain PTA-2684)
First discovered in a field in Buckingham in 1967
Now grown on an industrial scale to make ‘Quorn’

• Microbes grow quickly – high yields in short time.
• Uses less land to grow; can be set up anywhere
• Uses waste material ( eg whey) as a substrate
• No ethical issues with breeding / vegans
• Low fat or no-fat foods

• Contamination of culture vessels
• Consumer resistance / suspicion
• Need to have a substrate, produced by something else.
• Needs purifying before use

The future - modifying genetics to produce organisms with new “recombinant” traits.
-plants with resistance to disease and parasites.
-replacing a defective gene in a crop plant or animal
‘Agrobacterium’

Aspergillus fungus – the aflatoxins it produces are carcinogenic

• Lowers wp. Removes water from microbes by osmosis
• Eg salted cod, jams

• Ethanoic acid (vinegar) – lowers pH to <4
• Microbe enzymes denature.
• Eg pickled cabbage, onions

• Pasteurisation – brief flash heating to 72C for 15 seconds.
• Kills pathogens but not Lactobacillus , so flavour is preserved.

• UHT – brief flash heating to 135C for 15 seconds.
• Kills all bacteria, but flavour is compromised.

• Water is frozen, so not available to microbes.
• Enzymes are inactivated.
• Eg meat

• X-rays or Gamma rays kill microbes by denaturing proteins and
DNA.
• Eg fruit, prawns

• 1. Describe, using examples from agriculture, the principles of selective breeding.
• 2. Explain the term ‘food spoilage’ and describe how food may be prevented from going ‘off’.