Determine the ability of an organism to reduce nitrate to nitrite or free nitrogen gas using Thermo Scientific™ Remel™ Nitrate Reagent B. This ability is characteristic of the Enterobacteriaceae1 family. Nonfermenters and other miscellaneous gram-negative bacilli vary in their ability to reduce nitrates, with some being capable of further reducing nitrite to nitrogen gas2. In 1962, Daubner reported that all members of the Enterobacteriaceae tested, except for Erwinia species, reducing nitrate in eight hours3.
Determine the ability of an organism to reduce nitrate to nitrite or free nitrogen gas using Nitrate Reagent B.Ready to Use: Convenience of a prepared reagent.Ease of Differentiation: Positive test indicates red color development after addition of reagents; and no color development after addition of zinc dust. Negative test indicates no color development after addition of reagents and red color development after addition of zinc dust.Rapid Detection: The test can be detected within 10-15 minutes.Nitrate serves as a source of nitrogen for many bacteria and fungi, but to be utilized it must be broken down.The nitrite reduction test is a two-step procedure. Sulphanilic acid is added to acidify the medium and then naphthylamine is added which reacts with the nitrites to produce a red color. Certain bacteria convert nitrate to nitrite, ammonia, or gas. This process is denitrification. If no color develops after addition of reagents, the organism has either reduced the nitrate to free nitrogen or it has not attacked the nitrate at all. Nitrate will react with zinc dust to form nitrite. A red color development after addition of zinc dust indicates that the nitrates are present, indicating a negative nitrite reduction test. No formation of a red color after addition of zinc dust indicates that the organism has reduced the nitrate to free nitrogen or ammonia and is considered a positive nitrate test.Nitrate Reagent B is to be used in conjunction with Nitrate Reagent A, REF R21239.Not all products are available for sale in all territories. Please inquire.Remel™ and Oxoid™ products are now part of the Thermo Scientific brand.
- Ewing, W.H. 1986. Edwards and Ewings identification of Enterobacteriaceae. 4th Elsevier, New York, NY.
- MacFaddin, J.F. 2000. Biochemical Tests for the Identification of Medical Bacteria. 3rd ed. Lippincott Williams & Wilkins, Philadelphia, PA.
- Daubner, I. 1962. Arch, Hyg. Berlin. 146:147-150.