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Bacteriological water analysis is a method of analysing water to estimate the numbers of bacteria present and, if needed, to find out what sort of bacteria they are. It represents one aspect of water quality. It is a microbiological analytical procedure which uses samples of water and from these samples determines the concentration of bacteria ...
The TSI slant is a test tube that contains agar, a pH-sensitive dye , 1% lactose, 1% sucrose, 0.1% glucose, [2] and sodium thiosulfate and ferrous sulfate or ferrous ammonium sulfate. All of these ingredients are mixed together, heated to sterility, and allowed to solidify in the test tube at a slanted angle.
Inoculate a tube of glucose phosphate broth with a pure inoculum of test organism and incubate at 35 °C for 24 hours. To 1 mL of this broth add 0.6 mL of 5% α-Naphthol followed by 0.2 mL of 40% KOH. Shake the tube gently to expose the medium to atmospheric oxygen and allow the tube to remain undisturbed for 10–15 minutes.
Voges–Proskauer / ˈ f oʊ ɡ ə s ˈ p r ɒ s k aʊ. ər / or VP is a test used to detect acetoin in a bacterial broth culture. The test is performed by adding alpha-naphthol and potassium hydroxide to the Voges-Proskauer broth, which is a glucose-phosphate broth that has been inoculated with bacteria. A cherry red color indicates a positive ...
They gather in the upper part of the test tube but not the very top. 5: Aerotolerant organisms do not require oxygen and cannot utilise it even if present; they metabolise energy anaerobically. Unlike obligate anaerobes, however, they are not poisoned by oxygen. They can be found evenly spread throughout the test tube.
To perform the OF-glucose test, two tubes of OF-glucose medium are inoculated with the test organism. A layer of mineral oil is added to the top of the deep in one of the tubes to create anaerobic conditions. Oil is not added to the other tube to allow for aerobic conditions. The tubes are then incubated for 24–48 hours.
The test tube on the right shows a negative result as no acidic products are formed by fermentation. The methyl red (MR) test can detect whether the mixed acid fermentation pathway occurs in microbes when given glucose. A pH indicator is used that turns the test solution red if the pH drops below 4.4. [12]
However, they are poisoned by high concentrations of oxygen. They gather in the upper part of the test tube, but not the very top. 5: Aerotolerant organisms do not require oxygen as they metabolise energy anaerobically. Unlike obligate anaerobes, though, they are not poisoned by oxygen. They can be found evenly spread throughout the test tube.