Culture characteristic of bacteria

Prepared bySamira Fattah

Assis. Lec.College of health sciences-HMU

Lab 6

• Bacteria grow on solid media as colonies.• A colony is defined as a visible mass of

microorganisms all originating from a single mother cell.

Colony Morphology• These characters used to accurately describe the morphology

of a bacterial colony:-Size-Shape-Color (also known as pigmentation)-Texture-Height (elevation)-Edge (margin)

• Key features of bacterial colonies are important criteria for their identification.

COLONY CHARACTER ON AGAR PLATE

• Colony shape on agar plates

Rhizoid

Circular Pinpoint

• Margin of bacterial colony

Undulate filamentous

• Elevation of bacterial colony

Raised marginUmbonate

• Size of the bacterial colony

• Small• Medium• large

• Texture of bacterial colony

• Dry• Moist• 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)

• Iridescent(shine)

COLONY CHARACTER ON AGAR SLANT

• Growth on agar slants

beadedFiliform

GROWTH IN NUTRIENT BROTH

• Growth in nutrient broth

LAB EXERCISE

-Student will identify the growth patterns on the nutrient agar plates and slants, and in the nutrient broth tubes.