BIOL240L Study Guide - Final Guide: Bromocresol Purple, Indole, Ph Indicator
27 Nov 2017
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Document Summary
Indicates change in ph if acid produced in culture: production of indole. Indole is byproduct of the metabolic breakdown of amino acid tryptophan: presence of indole in medium w/ tryptophan demonstrated by adding kovac"s reagent. Results: a= acid production (yellow, k= alkaline colour change (dark blue, n = neutral, no change in colour (purple, g = gas formation. 2(cid:2870)(cid:1841)+(cid:1841)(cid:2870: bubbles of o2 seen = catalase positive. Materials: broth cultures: e. coli, pseudomonas aeruginosa (level 2) and bacillus subtilis, poured plate of starch (carbohydrate), tween 80 (fat) and skim milk (protein) Methods: divide plates into 3, label each third with name of organism, and swab each organism (one swab per culture) incubate plates at 37 for 48-72h. Methods: divide nutrient agar plate into 4 and sabouraud"s agar plate into 2, on agar plate swab staphylococcus aureus (sa) (level 2), serratia marescens (sm), Pseudomonas fluorescens (pf) and bacillus stearothermophilus (bs: on sabouraud"s plate swab saccharomyces cerevisiae (species of yeast) (sc) and.
