• Bacteria grow on solid media as colonies.
• A colony is defined as a visible mass of microorganisms all originating from a single mother cell.
• These characters used to accurately describe the morphology of a bacterial colony:
-Color (also known as pigmentation)
• Key features of bacterial colonies are important criteria for their identification.
COLONY CHARACTER ON AGAR PLATE
• Colony shape on agar plates
• Margin of bacterial colony
• Elevation of bacterial colony
Umbonate Raised margin
• Size of the bacterial colony
• Texture of bacterial colony
• Viscid (stick to loop)
• Mucoid (mucus-like)
• Colour of the colonies (pigmentation)
Some bacteria produce pigment when they grow in the medium.
• Opacity of the bacterial colony
• Opaque (not clear)
• Translucent (clear)
COLONY CHARACTER ON AGAR SLANT
• Growth on agar slants