What is Microbiolgy?

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 N2 2NH3
• 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 3000 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
Kochs Postulates

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