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Durham tubes are used in microbiology to detect production of gas by microorganisms. They are simply smaller test tubes inserted upside down in another test tube so they are freely movable. The culture media to be tested is then added to the larger tube and sterilized , which also eliminates the initial air gap produced when the tube is ...
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. If the medium in the anaerobic tube turns yellow, then the bacteria are fermenting glucose.
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.
Cragie tube: see link: Desiccator: to dry things Durham's tube: used to detect gas production in sugar fermentation media; the tube is placed in an inverted fashion so that gases produced get trapped in it and do not float away to the surface Gas-pak: releases gases to remove oxygen from a closed container, usually for anaerobiosis: Glass slide
Numerous fermentation pathways exist such as lactic acid fermentation, mixed acid fermentation, 2-3 butanediol fermentation where organic compounds are reduced to organic acids and alcohol. [8] [4] The energy yield of anaerobic respiration and fermentation (i.e. the number of ATP molecules generated) is less than in aerobic respiration. [8]
These lactic acid bacteria can carry out either homolactic fermentation, where the end-product is mostly lactic acid, or heterolactic fermentation, where some lactate is further metabolized to ethanol and carbon dioxide [19] (via the phosphoketolase pathway), acetate, or other metabolic products, e.g.: C 6 H 12 O 6 → CH 3 CHOHCOOH + C 2 H 5 ...
It acts as a confirmation test for lactose fermentation with gas production. Sodium lauryl sulfate inhibits organisms other than coliforms. Formula in grams/litre (g/L) Tryptose: 20.0, Lactose : 5.0, Sodium chloride : 5.0, Dipotassium phosphate : 2.75, Potassium dihydrogen phosphate : 2.75, Sodium dodecyl sulfate : 0.1 pH 6.8 ± 0.2
Stab cultures are similar to agar plates, but are formed by solid agar in a test tube. Bacteria is introduced via an inoculation needle or a pipette tip being stabbed into the center of the agar. Bacteria grow in the punctured area. [11] Stab cultures are most commonly used for short-term storage or shipment of cultures.