Fascinating creatures that thrive on giant crystals of iron, sulfur, zinc and other chemicals have been discovered in the giant crystal caves of Naica, Mexico. The director of Nasa’s Astrobiology Institute in Moffett Field, California, Penelope Boston, Claims to discover “super life form” i.e. 50000 years old microbes trapped in giant crystals of the old hot Mexican cave. The Naica caves of crystal giants are of great fascination for scientists all over the world who have interests in extremophiles. Previously many microbes have been discovered from the walls of the cave but the claim of Dr. Boston to isolate life forms from inside the giant crystals sounds to be a remarkable discovery.
The Naica caves of crystal giants are approximately 800 meters deep. The environment of the cave is extreme hot, humid and acidic. This makes it very difficult for anyone to work for more than 20 minutes inside the cave. The temperature is around 40-60 degrees C with no light at the depth of the cave. Scientists wear cheap versions of space suits while working inside the caves to prevent the contamination from microbes. Ice packs on the suit prevent excessive heat.
At the annual meeting of the American Association for the Advancement of Science (AAAS), Dr. Boston told that she had collected samples from fluid pockets inside the giant gypsum crystal in Naica caves of crystal giants in 2008 and 2009. Later her team revived the dormant microbes and found their ages to be between 10000 and 50000 years old. Boston found these microbes to be genetically distinct form all the known species on Earth. Even their nearest relatives, found in other caves and volcanic terrain, are still 10 % different genetically.
“Other people have made longer-term claims for the antiquity of organisms that were still alive, but in this case these organisms are all very extraordinary – they are not very closely related to anything in the known genetic databases,” said Dr. Penelope Boston.
These findings are approximately nine years old and are in the process of writing for publication. Even these have not yet gone through the peer review process so scientists are not saying much about this claim. Still many are skeptically criticizing the findings.
“But, reviving microbes from samples of 10,000 to 50,000 years is not that outlandish based on previous reports of microbial resuscitations in geological materials hundreds of thousands to millions of years old,” notes Brent Christner, a microbiologist at the University of Florida in Gainesville.
Some skeptical reviews correlate with the claimed age of the microbes. Scientists are wondering that how long a dormant microbe can survive in an environment of limited energy sources.
“I think that the presence of microbes trapped within fluid inclusions in Naica crystals is in principle possible. However, that they are viable after 10,000 to 50,000 years is more questionable,” says microbiologist Purificación López-García of the French National Center for Scientific Research, one of the co-authors of the 2013 study.
Scientist have yet to find that if the microbes could slow down their energy metabolism for the sake of survival.
“Perhaps they are surviving by eating dead microbes that weren’t so lucky.” Brent Christner, a microbiologist at the University of Florida in Gainesville.
Some scientists worry about the contamination of samples by the surrounding pool of water. They think that the microbes are not from inside the fluid. Similar microbes were discovered in 2013 from the hot saline springs deep inside the Naica Caves of crystal giants. Both types of microbes get their energy from the chemicals in the subsurface
“Contamination during drilling with microorganisms attached to the surface of these crystals or living in tiny fractures constitutes a very serious risk,” says López-García. “I am very skeptical about the veracity of this finding until I see the evidence.”
In response to the criticism, Boston explained that her team took various precautionary steps to avoid any kind of contamination. These include wearing protective space suits, using sterilized drills and also sterilizing the crystal surface with hydrogen peroxide and fire . They are confident enough that the samples contain microbes purely from inside the crystal fluids and not from the inclusions.
“We have also done genetic work and cultured the cave organisms that are alive now and exposed, and we see that some of those microbes are similar but not identical to those in the fluid inclusions,” Boston says.
Dr. Penelope Boston is hopeful that these samples will help other scientists to study the 50000 years old microbes in depth.
Boston says, the microbes her team collected, are “a precious resource and we want to make it available to other folks. There’s still a lot of work to do to infer anything about their history and movement and genetic relations.”