Explain the Selective Media - Culture Media?
It is used to select specific groups of bacteria by favouring the growth of desired bacteria and inhibiting the growth of undesired. Selection can be based on pH, water activity, nutritional content or presence of inhibitors. Example: Crystal violet, bile salts etc. inhibits gram positives while NaN3, thallous acetate, lithium chloride inhibits gram negatives. Example: oxytetracycline glucose yeast extract agar is selective for yeasts and moulds.