Microbial Diversity Flashcards
Size of Poliovirus (Poliomyelitis)
20nm
Size of Influenza virus (flu)
100nm
Size of Enterococcus faecalis (bacterium)
1-2um
Size of Dimeregramma sp. (golden algae)
50um
Amoeba sp. (protist)
100-750um
Antonie Van Leeuwenhoek (1674)
1st observation of a single cell using a microscope
Carl Linnaeus (1735)
Binomial nomenclature
Ernst Haeckel (1866)
The three kingdoms - Animalia, Plantae and Protista
Edouard Chatton (1937)
Suggests to divide living organisms in two categories (prokaryotes/eukaryotes)
Herbert Copeland (1938)
The four kingdoms - Animalia, Plantae, Protista (eukaryotes) and Monera (prokaryotes)
Robert Whittaker (1959)
The five kingdoms - Animalia, Plantae, Fungi, Protista (eukaryotes) and Monera (prokaryotes)
Carl Woese (1990)
The three domains, “new taxon” - Bacteria, Archaea and Eukarya
Phylogeny
Study of evolutionary history of organisms
How does Phylogeny work?
Evolutionary relationships are measured comparing genetic information - DNA sequences called molecular clocks - i) encoding conserved proteins with similar functions, ii) undergoing random and neutral mutations
Taxonomy
The discipline that deals with the classification of organisms
How does Taxonomy work?
Species are defined according to a taxonomic hierarchy. Classification involves the definition of taxonomic subdivisions and named using a binomial nomenclature
Phenotypic Analyses
- Morphology / Differential staining
- Metabolic properties
- Phage typing
- Fatty acid profiles
- Mass spectrometry
Genotypic Analyses
- DNA / DNA hybridisation
- Fluorescence In Situ Hybridisation (FISH)
- rDNA (16S) sequencing
- Multi Locus Sequence Typing (MLST)
What things generate diversity in bacteria?
- Binary fission
- Haploidy
- Genetic plasticity
