Owing to the extreme conditions, the community is not very diverse-with only a handful of species appearing, chief of which are the bacillus-like species thiomicrospira and desulfocapsa. These unique microbes are specially adapted to the underground environment and are able to utilize sulfur compounds to extract iron from the surrounding rock, which, along with carbon, is actively cycled through the cell to drive its key energy-harnessing and metabolic functions. Once excreted, the iron reacts with oxygen (in the water) and forms rust, which is the reason for the rusty-reddish color of the meltwater, and the name Blood Falls). The microbes are also adapted to an environment high in chlorides and sulfates, which are normally poisonous to many other microorganisms.
Such rare and isolated microbial communities give scientists a glimpse of the conditions on the early Earth that may have produced the first single-celled life forms. Scientist known as astrobiologists believe that by studying such extremophilic environments and organisms here on earth, they might shed light on the possibility of finding such lifeforms–or the “proto-biotic” environments that give rise to them–existing on other worlds, starting with those of our own solar system. Candidate, extra-terrestrial environments include: underneath the icecaps of Mars, within the ice-blanketed oceans of Jupiter’s moon Europa, or amongst the underground, and the sub-surface, cryo-volcanic flows of Saturn’s “planet-like” moon, Titan (the only moon possessing an atmosphere).
Reporting in the April 17 edition of Science Magazine, the team of explorers was lead by Jill Mikucki of Dartmouth College, New Hampshire (also of the University of Montana, and Harvard University), with support from the National Science Foundation.
Image credit: Zina Deretsky/NSF
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About Michael Ricciardi
