What is the scientific name for “microbial alchemy” , in which bacteria produce gold from toxins? What is the scientific name for bacteria that can do this? What are the formal scientific reasons for this? I’m skeptical of many of the popular websites I’ve seen on this subject.
Possible scientific formulations for this process
This perhaps?" microbially mediated metal sulfide-oxidation ?
biomineralisation of gold?
microbially induced precipitation of gold?
Well, first of all, calling it alchemy is stupid, because they’re not turning another substance into gold. They’re purifying gold from a solution of gold and other stuff. As to why the bacteria do this, this is just an educated guess, but I’d assume it’s a detoxification thing. The article says the bacteria live in mineral-rich environments, so they’d need a mechanism for getting metals out of themselves. The fact that it ends up being very pure just shows that it’s a really efficient mechanism.
Yes. I agree. Calling it alchemy is stupid. Unfortunately the media dumb this science down so it’s difficult to get at the real science behind the process. I would really like to know the proper scientific name for this process.
davidmich
Chemically speaking it is a reduction reaction: reduction of the gold in the gold chloride. In the chloride the gold will be in the form of positively charged gold cations which need to gain electrons (which is, somewhat confusingly, known as reduction) in order to get neutral, elemental gold.
I wonder where they get the gold chloride for this? There actually seem to be three or (if one is slightly loose with ones terminology, which may not be inappropriate to this article) four compounds that can be called gold chloride, but I think all of them are normally prepared from gold, which occurs as the metal in nature, not as a compound. This “alchemy” then, seems to be a roundabout way of preparing gold from gold, which is not too impressive. I suppose it might have a use as a way of separating gold from a mixture containing other metals: dissolve the stuff up in aqua regia, then set the bacteria loose to separate out the gold. I don’t know if this would have any advantages over the chemical and electrochemical methods already in use.
Thanks njtt. There seem to be a number of different processes in “metal biogeochemistry” going on depending on the types of bacteria involved. Some bacteria are detoxifying the metals they are in contact with and others are transforming them, all for the purpose it seems of regulating their natural habitat.
I see references to methylization. Still very confusing.
In biological systems, methylation is catalyzed by enzymes; such methylation can be involved in modification of heavy metals, regulation of gene expression, regulation of protein function, and RNA processing. Methylation of heavy metals can also occur outside of biological systems. Chemical methylation of tissue samples is also one method for reducing certain histological staining artifacts.