The Purple non-sulfur bacteria reference article from the English Wikipedia on 24-Apr-2004
(provided by Fixed Reference: snapshots of Wikipedia from wikipedia.org)

Purple non-sulfur bacteria

Support a children's charity online
Purple non-sulfur bacteria
Scientific classification
Domain:Bacteria
Phylum:Proteobacteria
Order:Rhodospirillales
Family:Rhodospirillaceae
Genera
Rhodospirillum
Azospirillum
Magnetospirillum
Phaeospirillum
Rhodocista
Rhodospira
Rhodothalassium
Rhodovibrio
Roseospira
Skermanella

The purple non-sulfur bacteria are a family (Rhodospirillaceae) of phototrophic bacteria that photosynthesize using bacteriochlorophylls a and b in anoxic environments, such as the bottom mud of ponds and other stagnant water, although they are able to survive in air. The reducing agent involved is hydrogen rather than water, so oxygen is not produced.

Members of the family range in color from purple to red and brown, with shapes including spherical, rod, vibrio, and spiral (Rhodospirillum).

The genus Magnetospirillum is magnetotactic; using chains of tiny crystals of magnetite, these bacteria are able to use the Earth's magnetic field to return to the bottom of a pond (since the magnetic lines of force run downwards as well as to the north or south). Similar magnetite chains found in Martian meteorites have been suggested as evidence of life of Mars.