Ok, so my da sent me a link to an article where some folks found that gold might just be precipitated out of a fluid environment by bacteria. They call it secondary gold grains. I am assuming that there is a layer on the gold which they consider “primary” which is covered by a layer that seems different. Haven’t seen the particulars on this as they weren’t in the short article…
The paper highlights the findings of a Cooperative Research Centre for Landscape Environments and Mineral Exploration (CRC LEME) project by CSIRO researcher, Frank Reith.
Dr Reith’s research has shown that bacteria play a significant role in the formation of secondary gold grains.
His study of gold grains from the Tomakin Park and Hit or Miss gold mines in southern New South Wales and northern Queensland, respectively, led to a series of discoveries, which showed that specific bacteria present on these gold grains precipitate gold from solution.
read the whole story…
I thought that was quite remarkable. So I did a quick google search on the bacteria that they found in all of the samples (note that I would think that the presence of more than one type of bacteria may be key).
Alcaligenes eutrophus CH34, recently renamed Ralstonia eutrophus is a gram-negative, non-spore forming bacterium which thrives in the presence of millimolar concentrations of several heavy-metals (Zn, Cd, Co,Pb,Hg, Ni & Cr). The heavy-metal resistance is conferred by two large megaplasmids (pMOL28=180 kbp and pMOL30=240 kbp) carrying gene clusters that encode cation-efflux machinery spanning both bacterial membranes. These low-copy number plasmids are stably maintained in the presence or absence of selective pressure and are self-transferable at relatively low frequencies.
A. eutrophus uses a variety of substrates as its carbon source or it can grow chemo-lithotropically using molecular hydrogen as the energy source and carbon dioxide as a carbon source. When nitrate is present A. eutrophus can grow anaerobically.
read the story…
And seeing as how the largest quantity of gold on the planet is dissolved in the ocean, this makes me wonder if you might be able to put this bacteria to some use. Gardens of gold and all that.
August 1st, 2006 at 9:25 pm
Your interesting speculation about a possible mutualism seems plausible, especially considering how common symbiotic/cooperative relationships are in nature. Makes me wonder if there might even be some value if humans were to develop the habit of looking for co-beneficial relationships first whenever we come across something in nature we don’t understand but would like to. I recently saw a Flickr macro image of a beetle on a thistle, and a closer look revealed a tiny fly perched on the beetle. One wonders (especially if one is addicted to speculation about scale) how far you would have to zoom in on, or out from, such a scene in order not to keep discovering new scales of functional relatedness nested like Russian dolls - especially if you expand your criteria of relatedness to include not just the visual schema revealed by a photograph but also other ways in which the multitude of Universe’s so-far indentified things have been found to interrelate: e.g., electrically, electromagnetically, gravitationally, psychically, chemically, emotionally, geometrically, harmonically, vibrationally, temporally, spatially, archetypically, etc., etc. (I don’t however mean this extemporaneous list to be complete or to be mutually exclusive). In Universe there apparently are many ways to zoom; many different things, each atom or organism or rock or cloud with its own array of senses and perception, conscious and unconscious. My take is that there is so much we have yet to learn, so many inklings we have yet to explore and try to understand, so many explanatory myths and world views we have yet to devise, revise and replace, that we will be busy for a long while. I do wonder whether Homo sapiens would be more aptly named Homo curioso - Curious Earth Being? (But first I’d better check my Latin.) Nice thought-provoking post, by the way.