Microbiology 2010C
Chapter 9 Objectives
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Discuss how and why microorganisms are named.
Describe the contributions of Linnaeus to taxonomy.
Describe how a dichotomous taxonomic key is used to identify organisms.
List and describe two major problems in creating a taxonomic system; note several important
taxonomic developments since Linnaeus's time.
List at least four major characteristics for each of the five kingdoms in the current system of
taxonomy.
Provide rationale for the need of the Three-Domain Classification System
List and describe the characteristics currently used in classifying viruses.
Provide several reasons why special methods are needed to determine evolutionary
relationships among prokaryotes; list the major methods currently used.
Chapter 9 Outline
I.
Taxonomy-The Science of Classification
A.
Linnaeus-the father of taxonomy
1
Binomial nomenclature
a.
Genus
b.
Specific epithet
c.
Species
d.
Strain
2.
Taxonomic hierarchy
B.
Using a taxonomic key
1.
Dichotomous key
2.
Bacterial dichotomous key
C.
Problems in taxonomy
D.
Developments since Linnaeus's time
1.
Contributions by Haeckel
2.
Bergey's Manual of Determinative Bacteriology
3. Contributions by Margulis and Copeland
4. Contributions by Whittaker
II.
The Five-Kingdom Classification System
A.
General features
B.
Kingdom Monera
1.
True bacteria
2.
Cyanobacteria
3.
Archaeobacteria
C.
Kingdom Protista
D.
Kingdom Fungi
E.
Kingdom Plantae
F.
Kingdom Animalia
III.
The Three-Domain Classification System
A.
The evolution of prokaryotic organisms
1.
Stromatolites
2.
Domain
B.
The tree of life is replaced by a shrub
C.
The Archaea
1.
Methanogens
2.
Extreme halophiles
3.
Extreme thermoacidophiles
IV.
Classification of Viruses
V.
The Search for Evolutionary Relationships
A.
Special methods needed for prokaryotes
B.
Numerical taxonomy
C.
Genetic homology
1.
Base composition
2.
DNA and RNA sequencing
3.
DNA hybridization
4.
Protein profiles and amino acid sequences
a.
Protein profile
b.
Polyacrylamide gel electrophoresis (PAGE)
D.
Other techniques
1.
Properties of ribosomes
2.
Immunological reactions
3.
Phage typing
E.
Significance of findings
1.
Major significance
2.
Divergent evolution
VI.
Bacterial Taxonomy and Nomenclature
A.
Criteria for classifying bacteria
1.
Type strain
2.
ATCC
B.
The history and significance of Bergey’s Manual
C. C. Problems associated with bacterial taxonomy
1. Taxonomy from the top down
2. Taxonomy from the bottom up
3. The muddle in the middle
D.
Bacterial nomenclature
E.
Bacteria by section of First Edition Bergey’s Manual
F.
Bacterial taxonomy and you
VII. The Discovery of New Organisms