purple bacteria

plural noun

1. a group of Gram-negative pink to purplish-brown bacteria, comprising the purple sulfur bacteria and purple nonsulfur bacteria, that occur in anaerobic aquatic environments and carry out a unique form of photosynthesis without oxygen, using the pigment bacteriochlorophyll.

Word History and Origins

Origin of purple bacteria¹

First recorded in 1895–1900

Example Sentences

There are also other bacteria (sulphur-bacteria, purple-bacteria, etc.) that show various peculiarities of metabolism.

From Project Gutenberg

The purple bacteria have thus two sources of energy, one by the oxidation of sulphur and another by the absorption of "dark rays."

From Project Gutenberg