Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Ex. 21: SIM Medium (Sulfur, Indole, Motility) Objectives ? Day 1 Materials needed per team Materials needed per table: of two students: Three pure slant cultures, one SIM tubes (3) each of: Proteus vulgaris Escherichia coli Klebsiella pneumoniae Work in a team of two students Day 2 Materials needed per team of two students: The 3 incubated SIM tubes from the last session. Materials needed per table: Kovac’s reagent 1. Sulfur Reduction Cysteine desulfurase releases H2S from S-containing amino acids Thiosulfate reductase releases H2S by allowing S2O32- to be final electron acceptor in anaerobic respiration Ferrous iron salt in medium leads to visible black precipitate (FeS) if H2S is produced SIM medium after 24h incubation. Table 21-1: Sulfur Reduction Results and Interpretation Result Interpretation Black in the medium Sulfur reduction (H2S production) No black in the medium Sulfur not reduced Symbol + 2. Indole Production See IMViC Table 21-2: Indole Production Results and Interpretation Result Interpretation Symbol Red in the alcohol layer of Kovac’s reagent Tryptophan is broken down into indole and pyruvate + Reagent color is unchanged Tryptophan is not broken down into indole and pyruvate Before addition of Kovac’s reagent 3. Motility Test Table 21-3: Motility Results and Interpretation Result Interpre- Symbol tation Growth radiating outward from Motile the stab line + No radiating growth Not motile SIM Medium Results and Interpretation? Tube 1: Tube 2: