In Earth's hottest place, life has been found in strong acid

Re:In Earth's hottest place, life has been found in strong acid by pdkl95 on Monday August 07, 2017 @08:45PM (#14952537)

There are at least 5 extremophile species in the biofilms at Iron Mountain, according to the sequencing done at the JGI[0][1] in the early 2000s. They've continued[3] sequencing more samples form the mine ove3r the last decade, so I suspect the actual number of known species is far higher.

The effort to sequence their genomes was one of the first attempts to directly sequence an environmental sample without first culturing and separating the individual species (with environmental samples, the separation happens during assembly). This is important when there no known way to culture the bacteria/archaea under investigation.

[0] Disclosure: I provided software support for this project.

[1] http://jgi.doe.gov/news_2_2_04/

[2] http://genome.jgi.doe.gov/?core=genome&query=acid%20mine&sea...

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Re:In Earth's hottest place, life has been found in strong acid by miles on Monday August 07, 2017 @10:04PM (#14953070)

This is one of those epic replies[1] that makes HN so neat. Wondering whether anything lives in Iron Mountain's hostile environment? No worries - the guy who provided software support for that project will elucidate the matter (with links to boot!).

[1] Perhaps the most epic of epic replies was Colin Percival's legendary snorter: https://news.ycombinator.com/item?id=35079

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Re:In Earth's hottest place, life has been found in strong acid by dekhn on Tuesday August 08, 2017 @03:45PM (#14961747)

I don't think they actually found living microbes in the pH -3.4 wash, though.

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Re:In Earth's hottest place, life has been found in strong acid by pdkl95 on Tuesday August 08, 2017 @06:29PM (#14963557)

Ferroplasma acidarmanus lives as a biofilm directly in the acid streams[1][2]. I'm not sure what the pH is in those specific areas, but it's very low (below 0). Compared to abiotic leeching of the iron pyrite in the mine, Ferroplasma greatly speeds up the reaction by using ferric iron as a catalyst:

    4Fe2+ + O2 + 4H+ → 4Fe3+ + 2H2O 
    FeS2 + 14Fe3+ + 8H2O → 15Fe2+ + 2SO42- + 16H+

The natural pyrite ore does not produce the extreme acid runoff. The problem starts when we mine out an area and oxygen is introduced, which is used to create Fe3+. This allows a much more efficient conversion of pyrite into a lot of acid.

This extremophile excretes pure sulfuric acid.

[1] https://microbewiki.kenyon.edu/index.php/File:Ferroplasma_1....

[2] https://digital.wwnorton.com/ebooks/epub/microbio4/OEBPS/ima...

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Re:In Earth's hottest place, life has been found in strong acid by dekhn on Thursday August 10, 2017 @12:00PM (#14980981)

Wow. Thanks, I wasn't aware of Ferroplasma acidarmanus or any other organism that excretes strong acids.

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