Specifications
Ingredients: gms/lit.Part A: Acetamide 10.00Part B: Sodium chloride 5.00Dipotassium hydrogen phosphate 1.39Potassium dihydrogen phosphate 0.73Magnesium sulphate 0.50Phenol red 0.012Final pH (at 25°C): 7.0 + 0.2Instruction for use :Suspend 7.63 grams of part B in 1000 ml distilled water. Add 10.0 grams of Part A. Heat ifnecessary, to dissolve the medium completely. Dispense in 10ml amounts in tubes or as desired.Sterilize by autoclaving at 15 lbs pressure (121°C) for 15 minutes.Principle:The media contains inorganic salts and acetamide a sole carbon and nitrogen source. However veryfew organisms growing in the medium metabolize acetamide by the process of deamination(acrylamidase activity). This unique ability is useful in identification of various non-fermentinggram-negative organisms. This ability is shown by Pseudomonas aeruginosa, Pseudomonasaciovorans Group III (Achromobacter xylosoxidans) and Alcaligenes odorans. Acetamidedeamination leads to the liberation of ammonia, which thereby increases the pH of the medium,leading to a subsequent colour change of the phenol red indicator from yellow orange to purplishred. Some strains require upto seven days to exhibit a positive reaction as they deaminateacrylamide slowly.Phosphates in the media serve as buffering agents, Magnesium sulphate is a source of ions thatstimulate metabolism whereas Acetamide serves as the sole nitrogen and carbon source. Sodiumchloride maintains osmotic equilibrium. Phenol red is the pH indicator.