Microbiology Workshop

MICROBIAL DIVERSITY

Cellular

• prokaryotes
• eukaryotes

Subcellular

• viruses

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