Answer to Question #165959 in Microbiology for qi

Question

1.  What is meant by “R” and “S” forms of bacterial colonies and what relation do they have to capsule formation?

2. of what practical significance are capsule-forming bacteria in industry?

Answer 1

S colonies are recognized by their moist nature, and are indicators of freshly isolated wild bacterial strains. R colonies are rough, dry, granulated, and mutant types of bacteria that lack most of the surface proteins including the capsule and lipopolysaccharides.

The capsule helps the bacteria to adhere to surfaces, camouflages the bacteria from the immune system by mimicking the host tissues, and makes the bacteria resistant to complement invasiveness.

2. The role of the bacterial capsule in industry is to keep the bacterium from drying, can serve as a virulence factor and as an antigen for identification, mediate adherence of cells to surface (crucial in biofilm formation), and confer protection against engulfment and attack by antimicrobial agents of plants and animals.