1. What is Microbiolgy? The study of microorganisms Unicellular organisms
Bacteria
Viruses
Multicellular organisms:
algae
Yeasts
mold

2. Characteristics of Living Organisms
Cellular organisms share the following characteristics:
Metabolism
Differentiation
Reproduction
Movement
Evolution
Communication

3. Microorganisms and their surroundings
Microbes live in a variety of ecosystems
Water
Soil
Organic surfaces
Plants
skin
Non-organic surfaces
Dishes
Countertops
plastic

4. Microorganisms and Agriculture
Microorganisms are both beneficial and harmful to agriculture:
Benefits:
Nitrogen fixation in legumes N NH3
Digestion of cellulose in ruminants (cows, sheep, and goats). Bacteria reside in the beginning of the digestive tract (rumen) and digest cellulose. This allows animals to extract enough nutrients from plants for survival.
Cellulose CO2 + CH4 + animal protein

5. Pathogenic Microorganisms
Due to improved conditions and development of antimicrobial drugs, the number of deaths from infectious diseases in the United States has declined significantly.
In 1900 – influenza, pneumonia, tuberculosis and gastroenteritis were the leading cause of death in the United States.
Infectious diseases are still the leading cause of death in the 3rd world countries.
Ex: African children die from malaria each day

6. Microorganisms and Food
Microorganisms are important to the food industry:
Yeast used to produce:
Yogurt
Beer
wine
Fungi used to produce:
cheese
Bacteria used to produce:
vinegar

7. Microorganisms and the Environment
Microorganisms are both detrimental and beneficial to the environment:
Bioremediation: use of microbes to clean the environmental spills
Bacteria oxidize oil to CO2 in oil spills
Microbial leaching: use of microbes to extract metals from low grade ores.
Bacteria solubilize minerals around trapped gold to release pure gold
Red tide: growth of toxin producing algae in warm, polluted costal waters.
Toxic to fish and humans

8. Biotechnology Microorganisms can be used to produce:
Large quantities of biological substances:
Ex: insulin, blood clotting factors
DNA used to replace unhealthy genes in diseased individuals.
Ex: Gene therapy
More durable crop plants resistant to herbicides, insects and viruses

9. History of Microbiology
Some names to remember:
Robert Hooke: (1664)
Used microscope to see cells
Anton van Leeuwenhoek: (1684)
Ferdinand Cohn: (1850)
Louis Pastuer: (1880)

10. Robert Koch In 1905 he won the Nobel Prize
Studied the transmission of diseases from one organism to the next.
Devised a set of conditions that mut be met to prove that a certain organism causes a disease.

11. Koch’s Postulates
Suspected pathogen should be present in all cases of diseased individuals and absent from healthy individuals.
Suspected pathogen should be grown in a pure culture.
Cells from the pure culture of suspected pathogen should cause disease in healthy individual.
Organism should then be re-isolated and shown to be the same as the original.