Shape:
* Circular: Colonies are generally round or slightly irregular.
Size:
* Medium to large: Colonies range from 2-5 mm in diameter.
Elevation:
* Convex: Colonies are raised in the center, forming a dome-shaped appearance.
Margin:
* Entire: The edge of the colony is smooth and even.
Surface:
* Smooth or slightly rough: Colonies can have a glossy or matte surface.
Texture:
* Buttery or creamy: Colonies are typically soft and easily disrupted.
Color:
* White or cream: Colonies are usually white, but can sometimes appear off-white or slightly yellowish.
Other characteristics:
* Beta-hemolytic: Some strains of B. cereus exhibit beta-hemolysis, forming a clear zone of hemolysis around the colony on blood agar plates.
* Motile: B. cereus is a motile bacterium, which can be observed microscopically.
Note: Colony morphology can vary depending on the specific growth conditions, such as the type of agar medium, incubation temperature, and time.
Example:
On blood agar plates, Bacillus cereus colonies are typically white, circular, convex, and beta-hemolytic.
Microscopic morphology:
Bacillus cereus is a Gram-positive, rod-shaped bacterium with rounded ends. It can form spores, which are highly resistant to heat and desiccation.
