1. Unit 4
Chapter 6
Microbiology

2. Bacteria Characteristics of bacteria: Microscopic
Unicellular (single-celled)
Prokaryote
Classified according to their shape: Rod, spherical (cocci) and spiral
Reproduce by binary fission.
© Edco

3. Structure of a bacteria
© Edco

4. Common diseases caused by bacteria in cattle and sheep
© Edco

5. Respiration
Mycobacterium bovis, the bacteria responsible for TB in cattle, is an aerobic bacteria. It can release energy from sugars in the presence of oxygen.
Lactobacillus bacteria can release energy from sugars in the absence of oxygen. This is called anaerobic respiration or fermentation.
© Edco

6. Reproduction Bacteria can reproduce asexually by binary fission.
The bacteria cell replicates its genetic information and then divides in two.
© Edco

7. Rhizobium
Rhizobium is a rod-shaped bacterium that has a symbiotic relationship with clover.
A symbiotic relationship occurs when two organisms have a close relationship that benefits both organisms.
The bacteria live in the root nodules of clover where they fix atmospheric nitrogen into nitrates.
© Edco

8. Experiment: To isolate and grow Rhizobium bacteria from the root nodules of clover
© Edco

9. Experiment: To isolate and grow Rhizobium bacteria from the root nodules of clover
© Edco

10. Experiment: To isolate and grow Rhizobium bacteria from the root nodules of clover
© Edco

11. Experiment: To isolate and grow Rhizobium bacteria from the root nodules of clover
© Edco

12. Fungi Characteristics of fungi: Eukaryotic
Lack chlorophyll, so they are unable to undergo photosynthesis
Fungal cell walls contain the carbohydrate chitin
Majority of fungi produce filaments called hyphae, some fungi, e.g. yeast, are single-celled
Can reproduce both asexually (spores) and also sexually (zygospores)
Heterotrophic.
© Edco

13. Basic structure of a fungi
© Edco

14. Fungal diseases of plants and animals
© Edco

15. Advantages/disadvantages of bacteria and fungi
© Edco

16. Viruses Characteristics of viruses:
Simple structure (capsid containing genetic material)
Genetic material of either DNA or RNA
All viruses are parasites
Viruses lack a cellular structure and do not contain cell organelles.
© Edco

17. Notifiable diseases
A notifiable disease is a disease that must be immediately reported.
Characteristics of notifiable diseases:
Spread quickly
Cause significant economic loss
Decrease productivity
Cannot be easily treated or controlled.
© Edco

18. Non-infectious diseases
A non-infectious disease is a disease that is not caused by a pathogen (micro-organism).
Milk fever and grass tetany are examples of diseases caused by a deficiency of a mineral in the diet of an animal.
© Edco

19. Biosecurity
Farmers try to prevent entry of disease onto their farms by
Maintaining a closed herd
Quarantining all bought-in stock
Providing good fencing to prevent contact of stock with neighbouring stock
Limiting access to the farm
Controlling vermin and ensuring that wildlife do not have contact with animal feeds
Ensuring all newborn animals receive colostrum from their mothers.
© Edco