The Birth of MicrobiologyKingdom Monera … The Bacteria

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:Louis Pasteur: rotting meat experiments dispelled ‘spontaneous generation’

The Story of Microbiology

• PasteurPasteur – Solved the French wine-spoilage problem. Used heat to destroy microbes …called “pasteurizationpasteurization”. Hypothesized that microbes could cause sickness… “Germ Theory”.

• Joseph ListerJoseph Lister – English surgeon…sterilizes surgical instruments…survival rates increase.

• Late 1800’s- Robert KochRobert Koch isolates and cultures bacteria responsible for anthrax in sheep and tuberculosis in humans.

• What household product did they name after Joseph Lister?

The Classification of Living Things:

All Living ThingsAll Living Things

AnimaliaAnimalia PlantaePlantae MICROORGANIMS

MoneraMonera FungiFungi ProtistaProtista

ArchebacteriaArchebacteria

EubacteriaEubacteria

Kingdom Monera

• Archaebacteria:Archaebacteria:• Primitive bacteria• Survive under extreme conditions• Types:Types: Thermophiles - extreme heat

Methanogens - swamps, no O2

Halophiles - salty enviro’s

• Eubacteria:Eubacteria:• More advanced bacteria, more common

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.

Bacteria Shapes:

Shapes:Shapes:• Coccus• Bacillus• Spirillum

Prefixes:Prefixes:• 1 = mono• 2 = diplo• Chain = strepto• Cluster = staphylo

What do you see???

Nutrition• HeterotrophsHeterotrophs: (most)

• Parasites (absorb nutrients from living orgs.) … or…• Saprobes (decay dead matter)

• AutotrophsAutotrophs- (few)• Use sunlight (cyanobacteria)

Respiration

• Occurs in the inner cell membrane• Aerobic Bacteria (need O2)

• Anaerobic Bacteria (no O2 needed)

-Eg. Clostridium Botulinum…Carrot juice

Reproduction

1. Binary fission Asexual

2. Conjugation Sexual …leads to resistance to antibiotics

Reproduction

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

Endospores in a human lung

Helpful Bacteria

• Nitrogen Fixation: • Converts N2 to the more useful NO3

• Nutrient Cycles: • Decompose Matter

• Waste Management & Bioremediation

• Sewage Treatment • (We produce 5 billion kg a day…bacteria break it down!)

Harmful Bacteria

• A small percentage are Pathogenic (disease causing)

• These bacteria produce deadly toxins or effects.

• E.g. Coliform levels in water = fecal pathogens

• Examples: Pneumonia, tuberculosis, botulism, Flesh Eating Disease

Streptococcus

Necrotizing Fasciitis