UNIT 2-Module 5-Ch10,11,12_Identification and Classification of Prokaryotic Organisms, The Diversity

This preview shows page 1 - 3 out of 28 pages.

UNIT 2-Module 5-Ch10,11,12:Identification and Classification of Prokaryotic Organisms, The Diversity of Prokaryotic organisms, The Eukaryotic Members of the Microbial World Ch10: Identification and Classification of Prokaryotic Organisms Describe how prokaryotes are identified, classified, and assigned names. Identification→ process of characterizing in order to group, occurs via microscopic examination, culture characteristics, biochemical tests and nucleic acid analysis Classification→ arranging organisms into similar or related groups via taxonomy→ science that studies organisms to arrange them into groups or taxa Three-domain system based on phylogeny, evolutionary relatedness. Replaces 5-kingdom system Based on obvious morphological differences Does not reflect recent genetic insights of ribosomal RNA data indicating plants and animals are more closely related to Archaea and Bacteria Bergey’s Manual of Systematic Bacteriology→ describes all known species which classifies them according to genetic relatedness. Also includes information on: ecology, methods of enrichment, culture, isolation, maintenance and preservation of organisms Nomenclature→ system of assigning names, genus followed by species species→ basic taxonomic unit, considered to be a group of morphologically similar organisms capable of interbreeding to produce fertile offspring Describe how phenotypic characteristics—including microscopic morphology, culture characteristics, metabolic capabilities, serology, and fatty acid analysis—can be used to identify prokaryotes. Microscopic morphology→ size, shape and staining size and shape determined by microscopically examining a wet mount 1
UNIT 2-Module 5-Ch10,11,12:Identification and Classification of Prokaryotic Organisms, The Diversity of Prokaryotic organisms, The Eukaryotic Members of the Microbial World staining→ i.e Gram stain and other special stains (i.e acid fast, endospore) Culture characteristics→ colony morphology can give initial clues to id I.e Pseudomonas aeruginosa→ often produces green pigment Differential media→ aids in identification I. e Streptococcus pyogenes→ (strep throat) yields B-hemolytic colonies on blood agar I.e E. coli→ (UTI) ferments lactose, forms pink colonies on MacConkey agar Metabolic capabilities→ (i.e type of sugars fermented or the end products) uses biochemical tests many of which rely on pH indicators relies on dichotomous key→ a flowchart of tests with positive or negative results, for identification Commercial biochemical kits allow rapid identification Serology→ proteins and polysaccharides of prokaryotic cells can be detected using specific antibodies, most useful for detecting surface structures such as: cell wall, capsule, flagella and pilli Fatty acid analysis→ prokaryotes differ in type, composition and quantities of fatty acid membranes. To do: 1) cells are grown under standardized conditions 2) treated with chemicals to release the fatty acids

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture