Question

In isolating bacteriophages from soil samples, why is CaCl2 added to the media?

a) CaCl2 aids in the stabilization of phage DNA during injection.
b) CaCl2 enhances the adsorption of phages to bacterial receptors.
c) It prevents the inhibitory effect of sodium citrate on phage action.
d) CaCl2 directly affects the growth of bacteria in liquid media.

What role does calcium play in phage adsorption, and is there an ideal concentration for maximizing adsorption in liquid media?

a) Calcium stabilizes phage capsids and has no effect on adsorption.
b) Calcium is essential for phage DNA injection but does not influence adsorption.
c) Calcium aids in the adsorption of phages to bacterial receptors by influencing the conformation of phage proteins.
d) The ideal concentration of calcium depends on the specific phage-bacteria system.

Answer 1

CaCl2 is added to the media to enhance the adsorption of phages to bacterial receptors during the isolation of bacteriophages from soil samples. The presence of calcium ions aids in the adsorption process by influencing the conformation of phage proteins. The ideal concentration of calcium for maximizing phage adsorption in liquid media varies depending on the specific phage-bacteria system.

Step-by-step explanation:

CaCl2 is added to the media when isolating bacteriophages from soil samples because it enhances the adsorption of phages to bacterial receptors. The presence of calcium ions aids in the adsorption of phages by influencing the conformation of phage proteins. This step increases the efficiency of phage infection and allows for the isolation and study of bacteriophages.

The ideal concentration of calcium for maximizing phage adsorption in liquid media depends on the specific phage-bacteria system. Different phages and bacterial strains may have different requirements and optimal concentrations of calcium. Therefore, it is important to optimize the concentration of CaCl2 for each specific system to achieve the best results.