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.

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.

References in periodicals archive ?
Even more striking were the results using electrodes, which demonstrated for the first time that purple bacteria are capable of using electrons from a negative electrode or "cathode" to capture CO2 via photosynthesis.
Capsule staining revealed the structure in the form of a halo around the purple bacteria in the dark field.
Donohue's lab is working with purple bacteria that use photosynthesis to produce hydrogen from a combination of cellulosic feedstocks and sunlight.
Such a pattern shows up in proteins carrying biochemical signals within organisms from purple bacteria to people.