It might not have a place in a fairy tale ( like the goof that laid halcyon eggs ) , but there ’s a bacterium that can absorb compound rich in toxic metals and extract Au from them , producing midget atomic number 79 nuggets . Now we know why .
The bacterium in interrogation is calledCupriavidus metalliduransand lives in soil rich in toxic element . As reported inMetallomics , an external group of research worker have worked out the molecular processes that take into account this biological gold deposition . It all has to do with how it deals with atomic number 29 and gold in the soil .
Both copper and gold are toxic in large quantities , but the bacterium has evolved to need copper to live . The soil thatC. metalliduranslive in is ample in toxic heavy metals , which the bacterium converts into a strain that is easier to be dealt with . If too much copper is present , the bacterium can set off a peculiar enzyme , call CupA , that can pump out all the excess Cu and keep the bacterium healthy .
" asunder from the toxic large metals , life atmospheric condition in these soils are not speculative , " senior source Professor Dietrich H. Nies , a microbiologist at the Martin Luther University Halle - Wittenberg , said in astatement . " There is enough hydrogen to conserve vitality and intimately no contest . If an being chooses to survive here , it has to find oneself a way to protect itself from these toxic substances . "
However , something funny happens when gold is present . Copper gold compounds are extremely toxic , so the bacteria needs to protect itself . To do this , the CupA is made inactive and a different enzyme , CopA , is made active . This transforms the Cu and amber compounds into forms that are difficult to absorb .
" This assures that few cop and gold compounds go in the cellular interior , " explain Nies . " The bacteria is poisoned less and the enzyme that pumps out the pig can dispose of the excess copper unimpeded . Another outcome : the gold compounds that are difficult to absorb transform in the outer area of the cell into harmless amber nugget only a few nanometres in sizing . "
