Iron Mountain Mine - Bacteria and Archaea

Bacteria and Archaea

The bacteria and archaea living in the mine such as Leptospirillum (bacteria) and Ferroplasma (archaea) are of interest because they can survive in this extreme environment, and because their metabolism contributes to the pollution. They form a pink biofilm several millimeters thick that floats on the surface of the hot water with a pH of 0.8. Since the bacteria cannot be isolated and cultured, scientists have performed community sequencing of the DNA of the five dominant species at once, assembling the genomes afterwards. Four new species were identified in this way in 2004. In 2005 the proteins produced by these bacteria were identified; of the 2033 found proteins 572 were unique to this biofilm. In 2006, Baker identified three novel archaea, the Archaeal Richmond Mine Acidophilic Nanoorganisms.

The bacteria obtain carbon from the air's carbon dioxide and nitrogen from the air's N₂ gas. They are aerobes and obtain energy by using oxygen to oxidize ferrous iron dissolved from the iron sulfide rock; in the process they produce sulfuric acid which releases more metals from the rock. The bacteria belong to the group of acidophilic ferrous iron oxidizers.