Inoculate each culture into a tube of tryptone broth to test for the production of indole from tryptophan. Tryptone is a peptone that contains high concentrations of tryptophan. Nitrate reduction. Inoculate a tube of Nitrate Broth. Incubate all tubes and plates at 30°C for 2-5 days. Period 2 Materials. 3 of each of the medium listed in Period

Reporting sample results. : Positive coliform, positive E. coli, high nitrate, high nitrite, surface water residual or turbidity, chlorine dioxide or chlorite. We recommend having your laboratory submit results to us, but ultimately it's the water system's responsibility to ensure correct reporting. Once reported, the results are available in

Nitrate reduction test results following growth of Escherichia coli, Alcaligenesfaecalis, and Pseudomonas aeruginosa in nitrate broth. Escherichia coli reduces nitrate to nitrite, as evidenced by the red color after addition of nitrate reagents A (sulfanilic acid) and B (dimethyl-α-naphthylamine) to the culture.

The agar plate nitrate reduction assay uses a similar principle of the culture broth (tube) nitrate reduction test but is performed directly on colonies on petri plates. A dilution series of test samples were surface plated on pre-poured M17 agar plates, allowed to dry (adsorb), and then overlaid with 10–12 mL nitrate agar (HiMedia) to entrap

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e coli nitrate reduction test