|
1.1 |
World of Microorganisms |
|
|
1. Classification of microorganisms
- Bacteria
- Fungi
- Protozoa
- Virus
- Algae
2.
|
|
|
Bacteria |
Fungi |
Protozoa |
Virus |
Algae |
Size |
0.2 µm - 10 µm |
10 µm - 100 µm |
5 µm - 250 µm |
0.02 µm - 0.4 µm |
1 µm - 100 µm
|
Shape |
Coccus, bacillus, spirilla, vibrio |
Spherical, filamentous |
Spherical, spindle-shaped, irregular shaped |
Sphetica;, helix, polyhedral, complex |
Spherical, oval-shaped, filamentous |
Nutrition |
Autotrophic, saprophytic, parasitic |
Saprophytes, parasitic
|
Saprophytic, parasitic |
- |
Autotrophic |
Habitat |
Air, water, soil, food, bodies of other organisms |
Places with decaying matter, faeces, animal skin and food |
Aquatic habitats, damp place, bodies of living organisms |
Live in living host cells, form crystals outside a living cell |
Aquatic habitats, damp place |
Method of reproduction |
Asexual: binary fission
Sexual: conjugation
|
Asexual: budding, spore formation
Sexual: conjugation
|
Asexual: binary fission
Sexual: conjugation
|
- |
Asexual: binary fission, spore formation
Sexual: conjugation
|
Example |
Bacillus sp., Vibro sp. |
Mushroom, yeast |
Paramecium sp., Ameoba sp. |
Influenza A virus |
Chlamydomonus sp.
Spirogyra sp.
|
|
|
3. Factors that affect the growth of microorganisms |
|
Factors |
Explaination |
Humidity |
Damp conditions promote the growth and reproduction of microorganisms.
In dry condition, some bacteria will form cyst or spores.
|
Light |
Microorganisms with chlorophyll prefer light condition.
Fungi and few bacteria prefer dark condition.
Exposure to UV light can kill microorganisms.
|
Temperature |
Most microorganisms prefer 35 °C - 40 °C.
Low temperature in refrigerator reduce growth rate of microorganisms.
High temperature can kill microorganisms.
|
pH value |
Optimum pH for most microorganisms is pH 7.
Some microorganism can live in environment with slightly acidic or alkaline.
|
Nutrients |
The growth rate of microorganisms depends on amount of nutrients. |
|
|
|