1. Fungi

2. Fungi There are many types of fungi.
Different types have different shapes and sizes.

3. Yeasts
Yeasts, used in bread making are tiny unicellular fungi.

4. Moulds
Moulds which grow readily on stale bread or over-ripe fruit are made up of many thin threads.
This gives the mould a fuzzy or furry appearance.

6. Mushrooms and Toadstools
These are larger structures which grow in the soil and humus.

7. Structure
A fungus is usually made of many fine threads called hyphae and structures called sporangia which contain spores.

8. Structure
The hyphae spread forming a tangled mat called a mycelium (visible to the naked eye.)

9. Nutrition Fungi grow on top of and down through their food source.
They obtain nutrients by releasing enzymes which break down the food so that it can be absorbed.
Each type of fungus can only grow on certain substances
E.g. bread mould can not grow on our skin.

10. Reproduction
Fungi grow from tiny particles called spores, which float in the air like dust.
Each sporangium contains thousands of spores.
Fungal spores can survive for years before they begin to grow.

11. Culturing Fungi Fungi will grow readily in warm, moist places.
Fungi can be cultured on a nutrient agar plate if incubated between 20 – 40 oC for 3-4 days.

12. Helpful Effects of Fungi
Mushroom Farming
Mushrooms are the fleshy fruiting bodies of certain fungi.
The button and flat mushrooms from shops are both Agaricus bisporus, the buttons are simply immature fruit while the larger, flat ones are older.

13. Helpful Effects of Fungi
Making Bread
The purpose of using yeast is to produce the gas that makes bread rise.
Yeast does this by feeding on the sugars in flour, and expelling carbon dioxide in the process. (Fermentation)
This carbon dioxide forms thousands of balloon-like bubbles in the dough, and the bread rises.

14. Helpful Effects of Fungi
Once the bread has baked, this is what gives the loaf its airy texture.

15. Helpful Effects of Fungi
Making Alcoholic Beverages
Although there is a distinction between beer and wine, they share one thing in common. They are the fermentation products of yeasts.
Fermentation can be summarized as:
Yeast + Glucose Ethanol + CO2

16. Helpful Effects of Fungi
Antibiotics
Fungi produce special chemicals which kill or slow the growth of other organisms such as bacteria which would otherwise compete with the fungus for nutrients.
We call these chemicals antibiotics.

17. Antibiotics
The best known antibiotic is penicillin which is produced by the mould fungus Penicillium.
Discovered by Sir Alexander Flemming in 1928.
Penicillin is still important today, but many variations are produced by mutant forms of the fungus.
Ampicillin; methicillin, oxacillin

18. Antibiotics Antibiotics attack bacteria in a variety of ways:
Some disrupt the production of the cell wall, preventing the bacteria from reproducing, or causing them to burst open.
Others interfere with protein synthesis, thus arresting bacterial growth.