Acetamide Agar (Twin Pack), 5 kg

Acetamide Agar is formulated as per the recommendation of Standard Methods for the Examination of Water and Wastewater (1). Gilardi and others showed that a wide variety of non-fermenting organisms were capable of utilizing acetamide by using basal mineral media (2, 3). However very few organisms growing in the medium metabolize acetamide by the process of deamination (acrylamidase activity) (4, 5). This unique ability is useful in identification of various non-fermenting gramnegative organisms (6, 7, 8). This ability is shown by Pseudomonas aeruginosa, Pseudomonas aciovorans Group III ( Achromobacter xylosoxidans ) and Alcaligenes odorans (9). Acetamide deamination 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 purplish red. Some strains require upto seven days to exhibit a positive reaction as they deaminate acrylamide slowly. However, only about 40% of apyocyanogenic strains of Pseudomonas aeruginosa exhibit a positive reaction. It is therefore, not advisable to rely on this test as the only criterion for identification. The medium contains inorganic salts and acetamide a sole carbon and nitrogen source. Sodium chloride maintains the osmotic equilibrium. Phenol red is the pH indicator. Storage and Shelf-life: Store below 30°C in tightly closed container and the prepared medium at 2-8°C.Use before expiry date on the label. References: 1. Eaton A. D., Clesceri L. S., and Greenberg A. W., (Eds.), 1995, Standard Methods for the Examination of Water and Wastewater, 21st Ed., APHA, Washington, D.C. 2. Gilardi, 1974, Antonie Van Leeuwenhoek, J. Microbiology Serol., 39:229. 3. Stainier, Palleroni and Doudoroff, 1966, J. Gen Microbiol., 43:159. 4. Pickett M. J. and Pedersen M.M., 1970, Can. J. Microbiol.,16:351. 5. Pickett M. J. and Pedersen M.M., 1970, Can. J. Microbiol., 16:401. 6. Hedberg, 1969, Appl. Microbiol., 17: 481 7. Smith and Dayton, 1972, Appl. Microbiol., 24: 143 8. Buhlmann, Vischer and Bruhin, 1961, J. Bacteriol., 82:787 9. Oberhofer and Rowen, 1974, Appl. Microbiol., 28:720.