TORTORA • FUNKE • CASE Microbiology AN INTRODUCTION EIGHTH EDITION B.E Pruitt & Jane J. Stein Chapter 10, part A Classification of Microorganisms Taxonomy • Taxonomy – The science of classifying organisms – Provides universal names for organisms – Provides a reference for identifying organisms QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. Taxonomy • Systematics or phylogeny – The study of the evolutionary history of organisms • All Species Inventory (2001-2025) – To identify all species of life on Earth • Major task Plant and Animal Kingdoms Taxonomy Bacteria & fungi put in the Plant Kingdom Kingdom Protista proposed for bacteria, protozoa, algae, & fungi • 1937 "Prokaryote" introduced for cells "without a nucleus" • 1961 Prokaryote defined as cells in which nucleoplasm is not surrounded by a nuclear membrane • 1959 Kingdom Fungi • 1968 Kingdom Prokaryotae proposed • 1978 Two types of prokaryotic cells found • 1735 • 1857 • 1866 The Three-Domain System Table 10.1 The Three-Domain System Figure 10.1 Table 10.2 Endosymbiotic Theory Figure 10.2 Figure 10.3 Scientific Names Kbebsiella pneumoniae Honors Edwin Klebs Source of Specific epithet The disease Pfiesteria piscicida Honors Lois Pfiester Disease in fish Salmonella typhimurium Honors Daniel Salmon Stupor (typh-) in mice (muri-) Streptococcus pyogenes Chains of cells (strepto-) Forms pus (pyo-) Penicillium notatum Tuftlike (penicill-) Spores spread in wind (nota) Trypanosoma cruzi Corkscrew-like (trypano-, borer; soma-body) Honors Oswaldo Cruz Scientific binomial Source of Genus name Taxonomic Hierarchy Figure 10.5 Species Definition • Eukaryotic species: – A group of closely related organisms that breed among themselves • Prokaryotic species: – A population of cells with similar characteristics – Clone: Population of cells derived from a single cell – Strain: Genetically different cells within a clone • Viral species: – Population of viruses with similar characteristics that occupies a particular ecological niche Domain Eukarya • Animalia: Multicellular; no cell walls; chemoheterotrophic • Plantae: Multicellular; cellulose cell walls; usually photoautotrophic • Fungi: Chemoheterotrophic; unicellular or multicellular; cell walls of chitin; develop from spores or hyphal fragments • Protista: A catchall for eukaryotic organisms that do not fit other kingdoms Prokaryotes Figure 10.6 References •• Bergey’s Manual of Determinative Bacteriology •Provides identification schemes for identifying bacteria and archaea •• Bergey’s Manual of Systematic Bacteriology •Provides phylogenetic information on bacteria and archaea •Morphology, differential staining, biochemical tests •• Approved Lists of Bacterial Names •Lists species of known prokaryotes •Based on published articles •Based on rRNA sequencing • Morphological Identification characteristics: Useful for identifying eukaryotes • Differential staining: Gram staining, acidfast staining • Biochemical tests: Determines presence of bacterial Methods Figure 10.8 Figure 10.7