Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.



Published on

Published in: Education, Technology


  1. 1. Classification of Microbes <ul><li>What are Microbes? </li></ul><ul><li>A microbe is any living thing that spends its life at a size visible sometimes only with a microscope. </li></ul><ul><li>It is too tiny to be seen with the naked eye. Microbes are the oldest form of life on Earth. </li></ul><ul><li>The term microbe is short for microorganism, which means small organism. </li></ul><ul><li>To help people understand the different types of microbes, they are grouped or classified in various ways. </li></ul><ul><li>Microbes are very diverse and represent all the great kingdoms of life. </li></ul>
  2. 2. Prokaryotes (Bacteria) <ul><li>Eubacter &quot;True&quot; bacteria </li></ul><ul><ul><li>Human pathogens </li></ul></ul><ul><ul><li>Clinical or environmental </li></ul></ul><ul><ul><li>One kingdom </li></ul></ul><ul><li>Archaea </li></ul><ul><ul><li>Environmental organisms </li></ul></ul><ul><ul><li>Second kingdom </li></ul></ul>
  3. 3. Eukaryotes <ul><li>Other cell-based life e.g. </li></ul><ul><li>Plants </li></ul><ul><li>Animals </li></ul><ul><li>Fungi </li></ul>
  4. 4. Prokaryotic vs. Eukaryotic Cells <ul><li>Prokaryotic cells </li></ul><ul><ul><li>No Nucleus </li></ul></ul><ul><ul><li>No Organelles </li></ul></ul><ul><ul><li>Cell Wall of peptidoglycan </li></ul></ul><ul><ul><li>Binary Fission </li></ul></ul><ul><ul><li>1 circular chromosome </li></ul></ul><ul><li>Eukaryotic Cells </li></ul><ul><ul><li>Nucleus </li></ul></ul><ul><ul><li>Organelles </li></ul></ul><ul><ul><li>If cell wall, Cellulose or chitin </li></ul></ul><ul><ul><li>Mitosis </li></ul></ul><ul><ul><li>Linear chromosomes </li></ul></ul>
  5. 5. <ul><li>Here is an outline of the major groups of microorganisms: </li></ul><ul><li>Viruses </li></ul><ul><li>Bacteria </li></ul><ul><li>Algae </li></ul><ul><li>Fungi </li></ul><ul><li>Protozoa </li></ul>
  6. 6. Bacteria <ul><li>Bacteria consist of only one cell, but they're a very complex group of living things. </li></ul><ul><li>Some bacteria can live in temperatures above the boiling point and in cold below the freezing point. </li></ul><ul><li>There are thousands of species of bacteria, but all of them are basically one of three different shapes. </li></ul><ul><li>Some are rod- or stick-shaped; others are shaped like little balls. </li></ul><ul><li>Others still are helical or spiral in shape. </li></ul><ul><li>Some bacteria cells exist as individuals while others cluster together to form pairs, chains, squares or other groupings. </li></ul>
  7. 7. Classification of Microbes <ul><li>Taxonomic Hierarchy For eg: Escherichia coli </li></ul><ul><ul><li>Domain Bacteria </li></ul></ul><ul><ul><li>Kingdom Monera </li></ul></ul><ul><ul><li>Phylum Proteobacteria </li></ul></ul><ul><ul><li> Class Gammaproteobacteria </li></ul></ul><ul><ul><li> Order Enterobacteriales </li></ul></ul><ul><ul><li>Family Enterobacteriaceae </li></ul></ul><ul><ul><li> Genus Escherichia </li></ul></ul><ul><ul><li> Species E. coli </li></ul></ul>
  8. 8. Classification of bacteria <ul><li>There are several approaches to bacterial classification </li></ul><ul><li>A. Morphological classsification . </li></ul><ul><li>Based on morphology bacteria are divided into various groups </li></ul><ul><li>1. Filamentous or higher bacteria- Actinomycetes </li></ul><ul><li>2. True or lower bacteria </li></ul><ul><ul><li> I. Gram positive bacilli </li></ul></ul><ul><li> Aerobes- corynebacterium, bacillus </li></ul><ul><li> Anaerobes-Clostridium, lactobacillus </li></ul><ul><li>II. Gram positive cocci </li></ul><ul><li>III. Gram negative cocci </li></ul><ul><li>IV. Gram negative bacilli or rods </li></ul><ul><li> </li></ul>
  9. 9. Gram-positive rods Gram-negative rods Gram-positive cocci Gram-negative cocci
  10. 10. <ul><li>V. coccobacilli- Brucella </li></ul><ul><li>3. Comma chaped- vibrios </li></ul><ul><li>4. Spirochaetes- Borrelia, Treponema </li></ul><ul><li>5 . Mycoplasmas- Cell wall deficient </li></ul><ul><li>6 . Ricketsia and chlamydia- Obligate parasites </li></ul>
  11. 11. <ul><li>B.Nutritional classification </li></ul><ul><li>I. Based on Energy requirements </li></ul><ul><li>Phototrophs: Derive energy from sunlight </li></ul><ul><li>Chemotrophs: Use Chemicals </li></ul><ul><li>II. Based on ability to synthesize essential metabolites </li></ul><ul><li>Autotrophs: Synthesize organic coumpounds from carbon dioxide and nitrogen </li></ul><ul><li>Heterotrophs: Depend on preformed organic compounds eg pathogens </li></ul><ul><li>III. Based on oxygen requirements </li></ul><ul><li>Aerobes </li></ul><ul><li>Anaerobes </li></ul>
  12. 12. Gram-positive cocci Anaerobic Gram-positive rods Anaerobic Gram-negative rods Anaerobic Gram-positive cocci Anaerobic Gram-negative cocci
  13. 13. <ul><li>IV. Based on temperature </li></ul><ul><li>Psychrophiles: Below 20°C </li></ul><ul><li>Mesophiles: 25-40°C </li></ul><ul><li>Thermophiles: 55-80°C </li></ul><ul><li>C . Biochemical classification : </li></ul><ul><li>LF </li></ul><ul><li>NLF </li></ul><ul><li>LLF </li></ul><ul><li>Production of Indole, H2S, Catalase, Oxidase, Urease etc </li></ul>
  14. 14. <ul><li>D. Classification based on staining reaction : </li></ul><ul><li>I. Based on Grams stain : </li></ul><ul><li> Gram positive bacteria </li></ul><ul><li>Gram negative bacteria </li></ul><ul><ul><li>II. Based on acid fast stain : </li></ul></ul><ul><li>Acid fast bacilli </li></ul><ul><li>Non acid fast bacilli </li></ul>
  15. 15. <ul><li>E. Serological/ antigenic classification </li></ul><ul><li>Microorganism possess many different kinds of antigens, based on which they are classified into </li></ul><ul><li>I. Serovars or Serotype </li></ul><ul><li>II. Sero groups </li></ul>
  16. 16. Major Taxonomic Groups of Bacteria per Bergey’s manual <ul><li>Gracilicutes – gram-negative cell walls, thin-skinned </li></ul><ul><li>Firmicutes – gram-positive cell walls, thick skinned </li></ul><ul><li>Tenericutes – lack a cell wall & are soft </li></ul><ul><li>Mendosicutes – archaea, primitive procaryotes with unusual cell walls & nutritional habits </li></ul>
  17. 17. <ul><li>Assignment: </li></ul><ul><li>Find out what is Bergey’s manual i n detail. </li></ul>