Purple Bacteria

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purple bacteria

[′pər·pəl bak′tir·ē·ə]
Any of various photosynthetic bacteria that contain bacteriochlorophyll, distinguished by purplish or reddish-brown pigments.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Purple Bacteria


photosynthesizing bacteria living in fresh or salt water. The bacteria contain red pigments, or caro-tenoids, which give colonies of the bacteria or accumulations of bacterial cells a dark red coloration. Carotenoids absorb energy (from the blue and green bands of the spectrum that penetrate the water to great depths) and transfer it to the bacteriochloro-phyll. Unlike green plants, sulfureous purple bacteria use hydrogen sulfide rather than water as a hydrogen donor, whereas nonsulfureous purple bacteria use organic substances. Molecular oxygen does not form during photosynthesis.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.