BIOL240 Study Guide - Final Guide: Tryptophan, Serratia Marcescens, Aureus
20 Feb 2015
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Document Summary
Production of indole = kovac"s reagent (turns red if indole is present) Indole is a by-product of the metabolic breakdown of amino acid tryptophan: tryptone broth, yes = red colour, no = no colour (except that of reagent itself) only e. coli tested positive. Production of hydrogen sulfide: when amino acids containing sulphur are metabolized by microorganisms, sim medium is rich in iron, yes = black medium, hydrogen sulfide reacts with the metallic ions (iron) to form a metal sulfide (black) Experiment 19: bacterial enzymes: extracellular enzymes = breakdown of substrates via hydrolysis, amylases = hydrolyze polysaccharides to sugars. If starch is hydrolyzed, a clear zone will surround the growth of the organism: proteases = hydrolyze proteins to peptides and amino acids. If casein is hydrolyzed, a clear zone will surround the streak of bacterial growth: lipases = hydrolyze lipids (fats) to glycerol and fatty acids.
