Fig. 14A: Production of Hydrogen
Sulfide but No Indole in SIM Medium
![](images/h2spos_indneg copy.jpg)
SIM medium turns black if hydrogen
sulfide is produced from the reduction of sulfur. If Kovac's reagent remains yellow, indole is not produced.
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Microbiology Laboratory Manual by Gary E. Kaiser, PhD, Professor of Microbiology
is licensed under a Creative Commons Attribution 4.0 International License.
Last updated: September, 2017