The ocean may be blue, but the saltier
bodies of water have a different a story. Some salt marshes
and lakes (the Dead Sea, Owens Lake, and the Great Salt Lake, to name a
few) can be seen emitting a purplish-pink tint. Why are the waters
running purple? A mysterious
resident known as Halobacterium sp.
This free-living, unicellular microorganism
flourishes in saturated salt solutions under intense solar radiation. Halobacterium sp., an archaeon, has
a unique ability to survive under both aerobic and anaerobic conditions.
Under anaerobic conditions, when oxygen isn't
available for ATP generation, the bacteria forms a purple membrane.
The main component of the purple membrane, Bacteriorhodopsin,
keeps Halobactium sp.'s life
cycle going in this time of famine by funtioning as an energy
an ability to change its color as its environmental conditions change -
as does this website: Pinkify!
Bacteriorhodopsin (BR) is a light-driven
ion pump which converts light energy into electrochemistry energy.
BR, the main component of Halobacterium's purple membrane, is a
seven-helical transmembrane protein with a retinal co-factor. In
the presence of sunlight, BR moves protons out of the Halobacterium
cell, creating a proton gradient. This proton gradient, in turn,
is used by ATP synthase, a second membrane protein, to generate chemical
energy in the form of ATP.