4: Bacterial Taxonomy Flashcards
science that studies organisms in order to arrange them into groups
taxonomy - Greek “taxis” arrangement or order, “nomis” law or “nemein” to distribute or govern
3 separate but interrelated areas of taxonomy
- classification - arranging organisms into similar or related groups for easy identification
- identification - characterizing organisms
- nomenclature - system of assigning names to organisms
importance of bacterial taxonomy
- organize huge amounts of knowledge
- predictions and frame hypotheses about
organisms - places organisms into meaningful, useful groups, with precise names, thus facilitating scientific communication
- accurate identification of organisms
1866, proposed the Kingdom Protista to include both organisms lacking a nucleus and simple nucleated organisms
Ernst Haeckel
proposed the current definition of prokaryotes
Rofer Stanier
1937, introduced the term prokaryote to distinguish cells with no nucleus
Edward Chatton
most widely accepted system of classification
five-kingdom system (Plantae, Animalia, Fungi, Protista (single-celled eukaryotes), and Prokaryotae (Monera)
who proposed the five-kingdom system
Robert Harding Whittaker, 1969
enumerate the who proposed who and the name of the kingdoms:
- three kingdoms
- five kingdoms
- six kingdoms
- three domains
- three kingdoms - Haeckel; Protista, Plantae, Animalia
- five kingdoms - Whittaker; Monera, Protista, Fungi, Plantae
- six kingdoms - Woese; Eubacteria, Archaebacteria, Protista, Fungi, Plantae, Animalia
- three domains - Woese
- Domain Bacteria: Bacteria
- Domain Archaea: Archaebacteria
- Domain Eukarya: Protists, Plants, Fungi, Animals
the naming of microorganisms according to established rules and guidelines, provides the accepted labels by which organisms are
universally recognized
nomenclature
body that governs bacterial nomenclature
International Committee on Systematic Bacteriology
(published in the International Journal of Systematic and Evolutionary Microbiology)
- introduced the binomial system of nomenclature
- established a hierarchy of taxonomic ranks
- two kingdoms: Plant and Animal
Carolus Linnaeus
- the casual or common name which varies from country to country and is in the local language
- e.g., as ‘typhoid bacillus’ and ‘gonococcus’
casual or common name
- same throughout the world usually of two words, the first being the name of the genus and the second the specific epithet
- genus (Latin) species (specific epithet, adjective or noun indicating some property of the same species)
e.g., Bacillus anthracis
Bacillus - small rods
anthracis - anthrax bacteria
!!! all scientific names in Latin or latinized
genus is always capitalized
scientific or international name
- basic taxonomic group or standard taxonomical unit
- considered to be a group of morphologically similar organisms that are capable of interbreeding to produce fertile offspring
species
!!! taxonomic hierarchies are arranged in a hierarchical manner
2 original bases of bacterial species
phenotypic and genotypic differences
- a collection of strains that share many stable properties and differ significantly
from other groups of strains
[bacterial] species
a population of organisms that descends from a single organism or pure culture isolate
strain
3 types of strain
biovars - strains that differ biochemically or physiologically
morphovars - differ morphologically
serovars - differ in antigenic properties
** the type strain is usually the first studied and characterized strain of a species
7 bacterial identification methods
- cellular morphology
- staining characteristics
- motility
- growth characteristics
- biochemical characteristics
- serological tests
- genetic analysis using nucleic acid probes and other molecular techniques (e.g. PCR)
- provides identification schemes schemes for identifying bacteria and archaea
- morphology, differential staining, biochemical tests
Bergey’s Manual of Determinative Bacteriology
- provides phylogenetic information on bacteria and archaea
- based on rRNA sequencing
Bergey’s Manual of Systematic
Bacteriology
5 classification systems
conventional classification
intraspecies classification
phenetic systems/Adansonian classification
phylogenetic classification
genetic approach
a classification system based on features like cell shape, size, morphology, staining behavior, sensitivity, etc.
conventional classification
