When I read NASA’s big announcement about a new bacteria, I thought this is old news. It has long been known that microorganism do exist in volcano. In fact scientist have been studying how such organism can live in such extreme conditions in hopes of finding a cure for diseases, and to suggest that alien life is possible on planets that were considered inhabitable. One article goes back to 2005 >> USGS 2005 article. It just feels like too much hype going on here and it is being trumpeted as a discovery of a new type of bacteria when it is not. All headlines were similar in declaring NASA discovers a new bacteria and possible proof of the existence of alien life. But such bacteria that feed on arsenic has been known to exist. What is news is Felisa Wolfe-Simon work in identifying the uniqueness of the DNA of this type of bacteria, compared to a normal organism. She is trying to prove existing theory including that of hers. Arsenic is toxic to normal living organism and is known to enhance DNA synthesis (thus cause cancer) at low concentration and suppressed DNA synthesis (kill cells) at higher concentration (source: Ziqiang Meng). So Felisa’s work might explain why these extremopohiles are able to withstand such extreme conditions. i.e. how their biochemistry is different from ours. Thereby increasing understanding of the mechanics of an existing microorganism.
This quote from NY Times offers a note of caution as to whether arsenic is really incorporated into the DNA.
By labeling the arsenic with radioactivity, the researchers were able to conclude that arsenic atoms had taken up position in the microbe’s DNA as well as in other molecules within it. Dr. Joyce, however, said that the experimenters had yet to provide a “smoking gun” that there was arsenic in the backbone of working DNA.
Plus the fact that they still grew better with phosphorous suggest that arsenic is not their native building block. Are they simply more tolerant and can take higher concentration of arsenic than normal organism? Like Ziqiang Meng study shows, at low concentration it might actually lead to increased synthesis of DNA. Is it possible that they are just simply able to take in much higher concentration of arsenic than the common organism? A threshold at which synthesis of DNA is halted?
It is quite interesting indeed to study how this organism functions.