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Description:This photograph depicted a QUAD Plate containing a xanthine growth media upon which Nocardia and Streptomyces Gram-positive bacterial colonies were grown. The results here were two positive, i.e., the ability for the organisms to decompose xanthine, and two negative growth patterns. Positive results appear as a clear halo around the colonies, while a negative result manifests as an absence of this clear halo, and instead one will note the deposition of a melanin-like pigment.
Both genera are members of the order Actinomycetales. These colonies were grown in an aerobic environment, which means these organisms thrive in the presence of oxygen.
High Resolution: Click here for hi-resolution image (5.69 MB)
Content Providers(s):CDC/ Dr. David Berd
Creation Date:1972
Photo Credit:
CDC Organization
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Copyright Restrictions:None - This image is in the public domain and thus free of any copyright restrictions. As a matter of courtesy we request that the content provider be credited and notified in any public or private usage of this image.