Microbiology

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Microbiology

• Bacteria, Viruses, Protists Fungi

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The Story of Microbiology

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

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The Story of Microbiology

• Pasteur Solved the French wine-spoilage
  problem. Used heat to destroy microbescalled
  pasteurization. He then hypothesized that
  microbes could cause sickness Germ Theory.
• Joseph Lister English surgeonsterilizes
  surgical instrumentssurvival rates increase.
• Late 1800s- Robert Koch isolates and cultures
  bacteria responsible for anthrax in sheep and
• tuberculosis in humans.

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Bacteria

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

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Bacteria Shapes (see handout)

• Coccus
• Bacillus
• Spirillum
• Prefixes
• 1 mono
• 2 diplo
• Chain strepto
• Cluster staphlo

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Gram Stain

• Stain turns bacteria violet if ve
• Gram ve common, less pathogenic
• Gram ve typhoid,
• meningitis, pneumonia

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Nutrition

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

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Respiration

• Occurs in the inner cell membrane
• Aerobic Obligate Aerobes (need O2)
• Anaerobic Obligate Anaerobes (no O2 needed)
• -Eg. Clostridium BotulinumCarrot juice

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Reproduction

• Asexually by binary fission.
• Sexually by conjugationleads to resistance to
  antibiotics (see handout)

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Reproduction

• 3. Endospores When conditions are unfavourable
  the bacteria forms a protective wall and lies
  dormant until conditions improve.

Endospores in a human lung
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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
  daybacteria break it down!)

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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
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Food Poisoning Anyone?
Escherichia Coli
Salmonella