bacterial colonies

Macroscopic characteristics


When we are studying a bacterial colony we can talk about macroscopic characterization. These are that features of a colony which can be seen by naked eye.

The most typical features are:
- the size of the colony
- the property of the edge of the colony and the inner structure
- the colour of the colonies (sometimes pigmentation occures)
- the locomotion of the colonies (e.g. 
Bacillus alvei and Bacillus helixoides: 14mm/hour)
- liquefaction of the solid media (eg. gelatin liquefaction by proteolytic microorganisms)
- the vertical position of the colonies in the test tube referring to the aerob/anaerob/facultative anaerob propertiy of the microorganism.