W have all heard the fairy tale about the goose that lays golden eggs. Obviously, such a goose doesn’t exist in reality but that doesn’t mean that some organism can’t do things with metals that are almost magic like.
C. metallidurans can produce small gold nuggets - Source: Martin Luther Universität Halle-Wttenberg
A great example of this is the Cupriavidus metallidurans bacteria. In 2009 we found out that these interesting little organisms can absorb toxic gold compounds and transform them into the metallic form of gold without being killed in the process. And now scientist finally know how exactly they do it. A several year-long research has found that they have a remarkable protective mechanics that not only works against gold but also against copper.
More specifically it’s all about enzymes called CupA and CopA. The first one has been already known for some time thanks to studying of a few different bacteria but the other one has so far been found only in Cupriavidus metallidurans. And it’s exactly this enzyme that allows the convert toxic golden compounds into forms that are less absorbable. Dietrich H. Niels from the Martin Luther University Halle-Wittenberg said that this is what prevents the bacteria from getting poisoned as fewer compounds get into the cell interior.
This mechanics allows Cupriavidus metallidurans to live in places where other species of bacteria die very quickly. And on top of that, it makes tiny little gold nuggets appear on the surface of these bacteria. Theoretically, this could allow us to use Cupriavidus metallidurans to get gold (and perhaps even other metals) even from ores that contain only trace amounts of these metals.
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