Chro·ma·ti·um | \krōˈmāshēəm\

Definition of Chromatium 

: a genus of purple sulfur bacteria (family Thiorhodaceae) that are ovoid to bean-shaped or rod-shaped, motile by polar flagella, reddish from a mixture of bacteriochlorophyll and carotenoid pigments, and widely distributed in fresh or salt water, some having been reported also from soil

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History and Etymology for Chromatium

New Latin, from chromat- + -ium

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