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billybob123 · 12-03-2010, 09:35 AM

There's always doubt about things like this as well (i.e. "game changers"). I read an article where a biologist suggested that there could have been trace elements of phosphates in the culture medium/vessels etc. Alternately, the bacteria might be good at recycling trace amounts of phosphorus into DNA and RNA backbones and the arsenates are associated somehow. I didn't know this but apparently the half-life of arsenate in (boring geek-speak coming up) arsenodiester backbones would be extremely short in aqueous environments (e.g. the cytoplasm of this bacteria). So either the DNA/RNA are stabilized in someway we don't know yet, or the hypothesis is wrong.

Phosphorus is also pretty important in regulating activity of proteins - protein phosphorylation is one of the key changers in signaling events; if this bacteria was able to evolve proteins that could use phosphates or arsenates interchangeably (I read the article and the bacteria seems to be able to switch between the two without problems) that would be really neat. Phosphates are also important in membranes - they make up the fats that form the membranes, which also have a lot of roles in signalling and cell survival.

The reason arsenic is so toxic to us is that it replaces phosphates in our cells; going back to grade 11 biology we all rememeber ATP (adenosine triphosphate) is formed in respiration - hydrolysis of ATP is what releases energy for most of the cell's requirements. If you swap P for As in these molecules, they're no longer hydrolyzable by the cell and therefore no energy = death.

This article is pretty cool to my eyes. I hope it's true - unique bacteria are pretty awesome to me.

Full disclosure: I'm a microbiologist who used to work on bacteria that did bioremediation and could grow on nitrobenzoate as a carbon source, producing nitrite (toxic) and using that as a nitrogen source. I used to love the enviromental microbiology field - too bad there's no money in it and that's why I'm in the medical micro field now. There's so many incredible bacteria out there that can do things that no one would think possible. With the right selection pressure and the proper means, bacteria can do almost anything we want. Awesome.

12-03-2010, 09:35 AM	#121
billybob123 Powerplay Quarterback Join Date: Sep 2010 Location: Calgary, AB Exp:	There's always doubt about things like this as well (i.e. "game changers"). I read an article where a biologist suggested that there could have been trace elements of phosphates in the culture medium/vessels etc. Alternately, the bacteria might be good at recycling trace amounts of phosphorus into DNA and RNA backbones and the arsenates are associated somehow. I didn't know this but apparently the half-life of arsenate in (boring geek-speak coming up) arsenodiester backbones would be extremely short in aqueous environments (e.g. the cytoplasm of this bacteria). So either the DNA/RNA are stabilized in someway we don't know yet, or the hypothesis is wrong. Phosphorus is also pretty important in regulating activity of proteins - protein phosphorylation is one of the key changers in signaling events; if this bacteria was able to evolve proteins that could use phosphates or arsenates interchangeably (I read the article and the bacteria seems to be able to switch between the two without problems) that would be really neat. Phosphates are also important in membranes - they make up the fats that form the membranes, which also have a lot of roles in signalling and cell survival. The reason arsenic is so toxic to us is that it replaces phosphates in our cells; going back to grade 11 biology we all rememeber ATP (adenosine triphosphate) is formed in respiration - hydrolysis of ATP is what releases energy for most of the cell's requirements. If you swap P for As in these molecules, they're no longer hydrolyzable by the cell and therefore no energy = death. This article is pretty cool to my eyes. I hope it's true - unique bacteria are pretty awesome to me. Full disclosure: I'm a microbiologist who used to work on bacteria that did bioremediation and could grow on nitrobenzoate as a carbon source, producing nitrite (toxic) and using that as a nitrogen source. I used to love the enviromental microbiology field - too bad there's no money in it and that's why I'm in the medical micro field now. There's so many incredible bacteria out there that can do things that no one would think possible. With the right selection pressure and the proper means, bacteria can do almost anything we want. Awesome.