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Colony Morphology

 

Characteristics of a colony such as shape, edge, elevation, color and texture. 
When recording colony morphology, it is important to also record color, optical properties (translucence, sheen) and texture (moist, mucoid or dry). However, remember that color is often influenced by environment. 

Shape

Margin (edges)

Elevation

Circular

circular edge diagram
bacterial colonies with circular edges

Entire (Smooth)

entire margin diagram

bacterial colonies with entire edges

Flat

 flat colony diagram

 

 

 

 

 

 

Irregular

irregular shape diagram

bacterial colonies with irregular shape

Undulate (Wavy) 

undulate edge diagram

bacterial colonies with undulate edges

Convex 

convex elevation diagram

bacterial colonies with convex elevation

Punctiform (tiny) 

punctiform diagram

bacterial colonies with punctiform shape

Rhizoid rhizoid edge diagram

bacterial colonies with rhizoid edges

Umbonate

umbonate elevation diagram

bacterial colonies with umbonate elevation

 
 

Lobate

lobate edge diagram

bacterial colonies with lobate edges

Raised

raised elevation diagram

 

 

 

 
 

Filamentous 

filamentous edge diagram

bacterial colonies with filamentous edges

Pulvinate (very convex) 

pulvinate elevation diagram

 

 

 

 

 

Turbidity

The cloudy appearance of a liquid medium due to the presence of bacteria.  You can "estimate" the number of bacteria per mL by using the table below. 

Turbidity

# Bacteria per mL

Example 

None 

0 - 106

 example of no turbidity

Light

107

 example of light turbidity

Moderate

108 

 example of moderate turbidity

*Heavy

109 

 example of heavy turbidity

 

 

*Usually bacterial populations do not exceed 3 x 109 bacteria/mL when grown in liquid media.