Fig. 9: Enterococcus faecalis Growing on Bile Esculin Azide Agar
A Bile Esculin Azide Agar plate before inoculation. Enterococcus faecalis growing on a Bile Esculin Azide Agar plate. Note black color.

Enterococci will grow in the presence of bile salts. As they grow, they hydrolize the esculin in the medium which turns the agar black. The sodium azide inhibits the growth of Gram-negative bacteria.
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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: April, 2018