Photosynthesis, that is. Get your mind out of the gutter! This admittedly sexy anaerobic green sulfur bacterium is capable of photosynthetic growth in the dark ocean depths. It’s able to use geothermal radiation from black smoker hydrothermal vents as a light source, making it the only photosynthetic organism known to use a light source other than sunlight.
Just as hot electric-stove elements radiate light, black smokers glow dimly as 400 degrees C fluid emerges. Most of the glow lies in the infrared spectrum, which the microbes can’t absorb, but part of the light reaches the edge of the visible spectrum. The microbes appear to eke out a living from that light, which the researchers can see only through night goggles.
“It expands our vision of possible environments where you could have photosynthesis,” says biochemist Robert Blankenship of Arizona State University in Tempe.
Apparently, telling these bacteria to ‘stick it where the sun don’t shine’ doesn’t have the same derogatory connotations typically implied.
Thermal image of ‘vent glow’ taken on the Juan de Fuca Ridge, credit John Delaney, University of Washington
See also Beatty et al. (2005) An obligately photosynthetic bacterial anaerobe from a deep-sea hydrothermal vent. PNAS 102(26): 9306-9310.