Question

What characterizes the colony morphology of Bacillus subtilis?

Answer 1

Hint: Bacillus is a Gram-positive rod-shaped bacterium genus. Bacillus species can be obligate aerobes, meaning they require oxygen to survive, or facultative anaerobes, meaning they can survive without it. When grown on nutrient agar media the colonies of Bacillus appear as either white or off white in color and form circular shaped colonies. Culturing of Bacillus species is usually done in pharmaceutical labs and teaching labs as a regular exercise.

Complete solution:
Bacillus subtilis is a very common bacteria of the genus Bacillus and is an example of culturable bacteria. They are often cultured for their diverse use in environmental microbiology and bioprocessing industries as they often produce antimicrobial compounds.
The colony morphology of Bacillus subtilis when cultured on nutrient agar media is as follows:
1. It forms white colored colonies on nutrient agar media.
2. The colony appears as a circular lobate in its configuration.
3. Its colony has an irregular margin.
4. The colonies of Bacillus subtilis are usually flat with no to very little elevation.
5. Bacillus subtilis shows a positive gram reaction and shows a central spore in endospore staining.
6. They appear as chains of rods when viewed in a microscopic field.

Note:
Bacteria can be cultured on solid media and grow as colonies. A colony is a visible collection of microorganisms that originated from a single mother cell. The identification of these bacterial colonies is aided by key characteristics of the colonies. The form of a colony can help identify bacteria in some cases. The size, shape, texture, elevation, pigmentation, and effect on the growth medium are all used to describe colonies.