purple bacteria

American  

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.

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Etymology

Origin of purple bacteria

First recorded in 1895–1900

Example Sentences

They dredged up gooey purple bacteria from a deep sinkhole in Lake Huron and tinkered with how much light it got in lab experiments.

From Seattle Times

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