1. Bacteria, Viruses, Protists & Fungi
Microbiology
Bacteria, Viruses, Protists & Fungi

2. The Story of Microbiology
From the time of the Romans to the late 1800’s it was believed that life could arise spontaneously from non-living matter Eg. Maggots on rotting meat, mould on bread
1850’s “childbed fever” is reduced when med students are forced to wash their hands.
Louis Pasteur: Dispelled ‘spontaneous generation’ – Air must contain microorganisms.

3. The Story of Microbiology
Pasteur – Solved the French wine-spoilage problem. Used heat to destroy microbes…called “pasteurization”. He then hypothesized that microbes could cause sickness… “Germ Theory”.
Joseph Lister – English surgeon…sterilizes surgical instruments…survival rates increase.
Late 1800’s- Robert Koch isolates and cultures bacteria responsible for anthrax in sheep and
tuberculosis in humans.

4. Bacteria All bacteria are single celled.
All are prokaryotes (no nucleus).
Cell organelles are not surrounded by membranes.
DNA is made of a single chromosome in a ring called a plasmid.
Most reproduce asexually.

5. Bacteria Shapes (see handout)
Coccus
Bacillus
Spirillum
Prefixes:
1 = mono
2 = diplo
Chain = strepto
Cluster = staphlo

7. Gram Stain Stain turns bacteria violet if +ve
Gram +ve: common, less pathogenic
Gram –ve: typhoid,
meningitis, pneumonia

8. Nutrition Most are Heterotrophs-
-Parasites (absorb nutrients from living orgs.) OR
-Saprobes (decay dead matter)
Autotrophs-
-Photoautotrophs- Use sunlight (cyanobacteria)

9. Respiration Occurs in the inner cell membrane
Aerobic – Obligate Aerobes (need O2)
Anaerobic – Obligate Anaerobes (no O2 needed)
-Eg. Clostridium Botulinum…Carrot juice

10. Reproduction Asexually by binary fission.
Sexually by conjugation…leads to resistance to antibiotics (see handout)

12. Reproduction
3. Endospores – When conditions are unfavourable the bacteria forms a protective wall and lies dormant until conditions improve.
Endospores in a human lung

14. Helpful Bacteria
Nitrogen Fixation – Converts N2 to the more useful NO3
Carbon Cycle – Decompose Matter
Waste Management – Bioremediation
Sewage Treatment (We produce 5 billion kg a day…bacteria break it down!)

15. Harmful Bacteria A small percentage are Pathogenic (disease causing)
These bacteria produce deadly toxins or effects.
Examples: Pneumonia, tuberculosis, botulism, Flesh Eating Disease
Streptococcus
Necrotizing Fasciitis
Clostridium Difficile

16. Food Poisoning Anyone?
Escherichia Coli
Salmonella