Course Notes for Intro to Microbiology
Rohde - Bio 2420
Chap. 1 – Scope and History of Microbiology
Why Study Microbiology?
1. Impact on Human Health
2. Balance of Nature - food source, play a role in decomposition, help
other animals digest grass (cattle, sheep, termites).
3. Environmental – provide safe drinking water; development of
biodegradable products; use bacteria to clean up oil spills, etc. – called
bioremediation.
4. Industrial – foodstuffs (beer, wine, cheese, bread), antibiotics, insulin,
genetic engineering
5. Agricultural - research has led to healthier livestock and disease-free crops.
I. Microbiology defined - The study of microbiology is the study of
microorganisms, which are organisms that are invisible to the naked eye.
II. Classification of Microorganisms
The 5 major groups of microorganisms: bacteria, algae, fungi, protozoa, and viruses. We
will also study some other smaller groups such as prions and viroids. The one property that
links these groups together is their very small size!
2 types of cells (viruses, prions and viroids are acellular – “without a cell”):
1. Prokaryotic ("before nucleus") – these guys are cells, but they have
no internal membrane bound structures (no membrane-bound
nucleus or membrane-bound organelles); includes only the bacteria.
2. Eukaryotic ("true nucleus") – do have internal membrane bound
structures (membrane bound nucleus and membrane-bound
organelles); includes organisms such as protozoans, fungi, algae,
animals, plants.
A. Bacteria (singular - bacterium) (study of bacteria – bacteriology)
1. prokaryotic
2. unicellular
, 3. size: 1/1000 the volume of a typical eukaryotic cell
4. 2 groups (discovered in 1970's) - we'll discuss more later
a. Archaeobacteria - ancient bacteria
b. Eubacteria - true bacteria
5. some shapes: bacillus (rod), coccus (spherical), spirillum (spiral),
vibrio (curved rod)
6. motile or nonmotile
7. how do they obtain their energy?
a. photosynthetic autotrophs - use energy from the sun to
produce their own carbohydrates for energy.
b. chemosynthetic autotrophs - process inorganic molecules
for energy (ex. sulfur or iron).
c. heterotrophs - depend on outside sources of organic
molecules (ex. carbohydrates or sugars) for energy
8. temperature extremes: -20oC to 110oC (that’s really cold & really
hot! freezing is OoC and boiling is 100oC)
9. examples of diseases?
B. Algae (singular - alga) - not a focus in this course.
1. eukaryotic
2. unicellular or multicellular
3. size: some microscopic, some macroscopic (ex. kelp)
4. motile or nonmotile
5. how do they obtain their energy? photosynthetic autotrophs
6. disease causing? no
C. Fungi (singular - fungus) (study of fungi – mycology)
1. eukaryotic
2. unicellular or multicellular (yeasts are unicellular, molds are
multicellular)
3. nonmotile
4. how do they obtain their energy?
a. heterotrophs
b. Why are they ecologically important? Scavengers; they live
off dead matter and thus, decompose it.
5. examples of diseases (called mycoses)?
examples of nonpathogenic fungi?
D. Protozoa ("first animals")
, 1. eukaryotic
2. unicellular
3. motile or nonmotile
4. how do they obtain their energy? Heterotrophs
5. disease causing – 2 examples: malaria & giardiasis (one of the
“don’t drink the water diseases”)
E. Viruses - (study of viruses – virology)
1. acellular, so not considered prokaryotic or eukaryotic; obligate
intracellular parasites; when they are outside of a host cell, there is
no evidence that these guys are alive.
2. basic structure of a virus - a piece of nucleic acid (RNA or DNA)
enclosed by a protein coat (capsid); possess no nucleus, organelles,
cell membrane, or cytoplasm.
3. size - 1/10 to 1/1000 the size of an ordinary bacterial cell.
4. nonmotile
5. examples of diseases?
Important Note: We will consider a sixth group, the helminths (worms), in our study of
microbiology. While most of the adult stages of these worms are macroscopic, many of
them go through a microscopic stage in their life cycles (egg & larval stages). Some
examples of helminths are tapeworms, hookworms, pinworms, heartworms, and Chinese
liver flukes. More to come later!!
III. A Brief History of Microbiology
C. Leeuwenhoeck (lived 1632-1723)
1. What discovery is he credited with? First person to use
microscopes to observe microbes; as a hobby he made small handheld
microscopes; he called microorganisms “animalcules.”
C. Hooke
1. What discovery is he credited with? He first described
“cellulae” (small rooms) in cork in 1665. His discovery led to the
formulation of the cell theory, which states that cells are the basic
organizational unit of all living things.
C. Redi and Spontaneous Generation
Rohde - Bio 2420
Chap. 1 – Scope and History of Microbiology
Why Study Microbiology?
1. Impact on Human Health
2. Balance of Nature - food source, play a role in decomposition, help
other animals digest grass (cattle, sheep, termites).
3. Environmental – provide safe drinking water; development of
biodegradable products; use bacteria to clean up oil spills, etc. – called
bioremediation.
4. Industrial – foodstuffs (beer, wine, cheese, bread), antibiotics, insulin,
genetic engineering
5. Agricultural - research has led to healthier livestock and disease-free crops.
I. Microbiology defined - The study of microbiology is the study of
microorganisms, which are organisms that are invisible to the naked eye.
II. Classification of Microorganisms
The 5 major groups of microorganisms: bacteria, algae, fungi, protozoa, and viruses. We
will also study some other smaller groups such as prions and viroids. The one property that
links these groups together is their very small size!
2 types of cells (viruses, prions and viroids are acellular – “without a cell”):
1. Prokaryotic ("before nucleus") – these guys are cells, but they have
no internal membrane bound structures (no membrane-bound
nucleus or membrane-bound organelles); includes only the bacteria.
2. Eukaryotic ("true nucleus") – do have internal membrane bound
structures (membrane bound nucleus and membrane-bound
organelles); includes organisms such as protozoans, fungi, algae,
animals, plants.
A. Bacteria (singular - bacterium) (study of bacteria – bacteriology)
1. prokaryotic
2. unicellular
, 3. size: 1/1000 the volume of a typical eukaryotic cell
4. 2 groups (discovered in 1970's) - we'll discuss more later
a. Archaeobacteria - ancient bacteria
b. Eubacteria - true bacteria
5. some shapes: bacillus (rod), coccus (spherical), spirillum (spiral),
vibrio (curved rod)
6. motile or nonmotile
7. how do they obtain their energy?
a. photosynthetic autotrophs - use energy from the sun to
produce their own carbohydrates for energy.
b. chemosynthetic autotrophs - process inorganic molecules
for energy (ex. sulfur or iron).
c. heterotrophs - depend on outside sources of organic
molecules (ex. carbohydrates or sugars) for energy
8. temperature extremes: -20oC to 110oC (that’s really cold & really
hot! freezing is OoC and boiling is 100oC)
9. examples of diseases?
B. Algae (singular - alga) - not a focus in this course.
1. eukaryotic
2. unicellular or multicellular
3. size: some microscopic, some macroscopic (ex. kelp)
4. motile or nonmotile
5. how do they obtain their energy? photosynthetic autotrophs
6. disease causing? no
C. Fungi (singular - fungus) (study of fungi – mycology)
1. eukaryotic
2. unicellular or multicellular (yeasts are unicellular, molds are
multicellular)
3. nonmotile
4. how do they obtain their energy?
a. heterotrophs
b. Why are they ecologically important? Scavengers; they live
off dead matter and thus, decompose it.
5. examples of diseases (called mycoses)?
examples of nonpathogenic fungi?
D. Protozoa ("first animals")
, 1. eukaryotic
2. unicellular
3. motile or nonmotile
4. how do they obtain their energy? Heterotrophs
5. disease causing – 2 examples: malaria & giardiasis (one of the
“don’t drink the water diseases”)
E. Viruses - (study of viruses – virology)
1. acellular, so not considered prokaryotic or eukaryotic; obligate
intracellular parasites; when they are outside of a host cell, there is
no evidence that these guys are alive.
2. basic structure of a virus - a piece of nucleic acid (RNA or DNA)
enclosed by a protein coat (capsid); possess no nucleus, organelles,
cell membrane, or cytoplasm.
3. size - 1/10 to 1/1000 the size of an ordinary bacterial cell.
4. nonmotile
5. examples of diseases?
Important Note: We will consider a sixth group, the helminths (worms), in our study of
microbiology. While most of the adult stages of these worms are macroscopic, many of
them go through a microscopic stage in their life cycles (egg & larval stages). Some
examples of helminths are tapeworms, hookworms, pinworms, heartworms, and Chinese
liver flukes. More to come later!!
III. A Brief History of Microbiology
C. Leeuwenhoeck (lived 1632-1723)
1. What discovery is he credited with? First person to use
microscopes to observe microbes; as a hobby he made small handheld
microscopes; he called microorganisms “animalcules.”
C. Hooke
1. What discovery is he credited with? He first described
“cellulae” (small rooms) in cork in 1665. His discovery led to the
formulation of the cell theory, which states that cells are the basic
organizational unit of all living things.
C. Redi and Spontaneous Generation
