L2 FT 15 LEC -

• Microbial Nomenclature

  • Naming organisms 
  • System developed by Carolus Linnaeus
• Rules in Naming 

  GENUS + SPECIFIC EPITHET = SCIENTIFIC NAME

  • Genus - Capitalized first letter 
  • Specific Epithet not capitalized 
  • Both are italicized or underlined
  • Binomial Nomenclature
• Examples of scientific name

  • Moringa oleifera - Malungay

  • Helianthus annus - Sunflower

  • Canis familiaris - dog

  • Bacillus thuringiensis (Bt)

  • Escheria coli (E.coli)

  • Rhizopus stolonifer (bread mold)
• Microbial Classification

  • Before discovery of microbes, organisms were grouped into 2 kingdoms: ANIMAL & PLANT
  • Basis: NUTRITION & MOBILITY

  Carolus Linnaeus: Father of Taxonomy
• Classifying Organism

  • Advent of microbes (17thcentury)
  • Both animal & plant characteristics
  • Blurred lines!
  • Thus, need for new classification
• • 1987: Carl Woese devised a Three-Domain system of classification
  • Basis: cellular organization
• Carl Woese’s THREE-DOMAIN SYSTEM

  • Common Ancestor: Bacteria, Archaea, Eukarya
• BAFAPV

  Bacteria

  Archaea

  Fungi

  Algae

  Protozoa

  Viruses
• • Bacteria: 

                   •  Cell walls have PEPTIDOGLYCAN

                   •  Example: Campylobacter jejuni: undercook chicken meat

                   •  Classification of shapes: Cocci, Bacilli, Spirilla, Others

                   •  Unicellular

                   •  Prokaryotes

                   •  Peptidoglycan Cell wall

                   •  Asexual Reproduction (Binary Fission)

                   •  Metabolically diverse: 

                            • photosynthesis 

                            • fermentation

                            • respiration
• • Archaea: 

      • LACK PEPTIDOGLYCA

      •  Example: Methanococcus jannaschii from deep sea chimneys

      •  Unicellular

                  •  Prokaryotes

                  •  Unique cell wall & membrane

                  •  Metabolically diverse

                  •  Extremophiles: 

                • thermophiles (high temps)

                            • halophiles (high salt conc.)

                            • acidophiles (acidic env’t)
• • Eukarya: 

      •  Protist

      •  Fungi

      •  Plants

      • Animals
• Fungi

  • Eukaryotic 
  • Most are filamentous(some are unicelleular)
  • Chemoheterotrophic

       • No photosynthesis

       • derive energy from organic matter in environment

  -Yeast, Molds, Mushrooms
• • Yeast: Unicellular, Oval

            • S. cerevisiae (brewer’s yeast)

  • Molds: Hyphae from mycelia

            •  Aspergillus oryzae (koji mold)

  • Mushrooms: Large, Multicellular

             • Agaricus bisporus (cultivated mushroom)
• Algae

  • Photosynthetic
  • Diverse Cell structure
  • Found in variety of aquatic environments
  • Also found in soil, on rocks, etc.
  • Seaweeds
  • Example: Brown Algae, Red Algae, Diatom
• Protozoa

  • Eukaryotic
  • “Animal-like”
  • Unicellular (lack of cell wall)
  • Heterotrophic 
  • Motile:

                  • cilia

                  • flagella

                  • pseudopodia
• Viruses

  • Need host to replicate 
  • Much smaller than bacteria & other microbes 
  • Have high mutation rate 
  • Don’t respond to antibiotics
• Peptidoglycan 

  • a carbohydrate-protein complex (made of sugars &amino acids)
  •  forms cell wall of most bacteria
  •  cross-linking of AAs form a strong mesh-like network that gives structure to the cell
• • Life: Superkingdom Prokaryata

                  •  Kingdom Bacteria

                  •  Kingdom Archaea

  • Life: Superkingdom Eukaryota

                  •  Kingdom Protozoa

                  •  Kingdom Chromista

                  •  Kingdom Plantae 

                  •  Kingdom Fungi

                  •  Kingdom Animalia