Microbiology Workshop

MICROBIAL DIVERSITY

Cellular

Subcellular

A. CELLULAR MICRO-ORGANISMS
PROKARYOTES
  • cellular components float in cell fluid
  • no nuclear membrane
  • nucleoid region is a loop of nucleic acid


BACTERIA

  • single cells
  • thin cell wall
  • simple shapes - rods, spheres, spirals, filaments
  • 0.5 - 5
  • beneficial effects
    - industrial and agricultural processes
    - transformations of material and energy e.g. in soil
  • harmful effects
    - plant and animal diseases
EUKARYOTES
  • nuclear region located within a membrane
  • cytoplasmic components (organelles) are membrane bound (e.g. mitochondria, chloroplasts, E.R.)
  • usually complex cell structure


PROTISTS (Protists)

  • all single celled organisms not included in the other eukaryote groups
  • diverse range of eukaryotic cell types
  • unicellular or colonial
  • photoautotrophic - sometimes called algae
  • heterotrophic - extra-cellular digestion, phagocytosis

FUNGI (Fungi)

  • spore bearing
  • reproduce sexually and asexually
  • filamentous, branching hyphae which grow apically
  • cell walls contain chitin
  • heterotrophic by extracellular digestion
B. SUBCELLULAR MICRO-ORGANISMS
VIRUSES
  • non-living
  • cannot reproduce independently of living cells
  • nucleic acid strand, sometimes surrounded by protein, with or without a membrane of host cell origin
  • diseases
    - human:
      - common cold
      - influenza
      - AIDS
      - small pox
      - mumps
      - measles
      - chicken pox
    - animal:
      - foot and mouth
      - myxomatosis
    - plant:
      - tobacco mosaic