14. Microbial Taxonomy and The Tree of Life Flashcards
how are microorganisms taxonomically diverse?
- morphology
- physiology
- phylogeny
- domains
– prokaryotic
– eukaryotic
what is phylogeny?
- genetic means of grouping microorganisms
- evolutionary relationship of microorganisms
how are microorgansims clasiffied relative to ecosystem?
- significant contribution of sustainability in ecosystem
how are microorganisms classified industrially?
- important biomolecules produced
– antibiotics
– anti-cancer drugs
– biofuel
– enzymes
what are the classifications of life?
- life
- domains
- kingdom
- phylum
- class
- order
- family
- genus
- species
- strains
what is a chronometer?
- meter of passing time
– some proteins
what features of proteins are relevent for taxonomy?
- features present in all members of traget group
– and functionally homologous in the organisms - must contain regions of conserved sequences
– for comparison purposes - must have slow rate of evolutionary change
– genetic changes must be slow enough to permit measurement that may also reflect evolutionary change
what are the sequences used to measure evolutionary relationships?
- 16S rRNA
– bacteria
– archaea - 18SrRNA
– eukaryotes
what is the phylogenic tree of life?
- universal ancestor
- 3 classifications
– bacteria
– archaea
– eukarya
how do you construct a linear phylogenetic tree?
- often measured as number of nucleotides different per 100 base pairs
- branch length indicates amount of evolutionary change
what methods are used to detect microorganisms?
- amplify and sequence highly conserved genes
– 16S rRNA
– 18S rRNA - sequence entire genome
what does the old tree of life look like?
- archaea closer related to bacteria than eukaryotes
what does the new tree of life look like?
- archaea more closely related to eukaryotes than bacteria
- bacterial domain
– has majority of evolutionary diversity - major domains identified within bacteria and archaea
- prevalence of lineages that have never been isolated before
what is the dramatic expansion of the archaeal domain?
- new phyla
– nano archaea
— lack the genes required for synthesis of own macromolecules (things needed to live)
what are nanoarchaea?
- episymbionts
– attach to host microbial cell surface - very closely associated with thermoplamotolies archaeon
– allows for the transfer of macromolecules into nanoachaea
how was a nanobacteria found?
- enriching and filtering water
– first 1.2 micrometers
– second 0.2 micrometes - all genomic extracted
how is phylogeny depicted as a heatmap?
- host cell related to symbiont
– proteins transferred
– comon proteins between two related organisms
what is the evolutionary step between eukarya and archaea?
- nanoarchaea bridge gap between eukaryotes and archaea
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