Buffered Nitrate Motility Medium

This is a modification of the original Nitrate Reduction Broth which is generally used as one of a series of identification tests for the enterobacteriaceae group of organisms. In addition to allowing the testing of Nitrate Reduction this formulation also contains Agar making it possible to concurrently determine motility. The medium is recommended for use in the confirmatory testing of Clostridium perfringens in water samples. The medium is inoculated by “stabbing” the test organism into the medium, using an inoculating needle or straight wire, and after appropriate incubation motility is demonstrated by diffusion of the organism from the line of inoculation into the medium. The Nitrate Reduction Test is a test for the presence of the enzyme nitrate reductase which, in the presence of an appropriate electron donor, reduces nitrate to nitrite. Following incubation “Nitrate Reagent” is added to the medium and a positive reaction is indicated by the formation of a red colour. For full details of the test method reference should be made to appropriate publications.