[CaptainPanic]

Psycho, on 7 November 2011 - 09:10 AM, said:

Bacteria can't survive boiling water by the definition of their name.

They cannot survive boiling, because they would be ripped apart by the expanding steam.
But they can survive >100°C easily.

Here's an article (in Nature) about bacteria surviving >250°C in deep sea hydrothermal vents.

[Psycho]

CaptainPanic, on 7 November 2011 - 10:59 AM, said:

They cannot survive boiling, because they would be ripped apart by the expanding steam.
But they can survive >100°C easily.

Here's an article (in Nature) about bacteria surviving >250°C in deep sea hydrothermal vents.

No there is an article about Archaea in hydrothermal vents, and the highest temperature any known Archaea can survive at is 121 degrees as I already stated, quoting a nature article published 30 years ago in a science that is relevantly only 90 years old is hardly a good source, especially considering its archaic wordage, Archaea and bacteria have been classified differently by taxonomy and microbiologists for a long time.

Hyperthermophilic bacteria don't exist, it is an impossibility due to their definition as already stated.

This post has been edited by Psycho: 7 November 2011 - 05:53 PM

[hypervalent_iodine]

Psycho, on 7 November 2011 - 05:51 PM, said:

No there is an article about Archaea in hydrothermal vents, and the highest temperature any known Archaea can survive at is 121 degrees as I already stated, quoting a nature article published 30 years ago in a science that is relevantly only 90 years old is hardly a good source, especially considering its archaic wordage, Archaea and bacteria have been classified differently by taxonomy and microbiologists for a long time.

Hyperthermophilic bacteria don't exist, it is an impossibility due to their definition as already stated.

Archaic wordage or not, it doesn't take away from the fact that they were able to culture an organism, found in a hydrothermal vent at temperatures exceeding 250^oC.

I'd also like to add a few more papers into the mix, which I found from the citation list of the one that Captain Panic linked:

Pyrococcus furiosus sp. nov. represents a novel genus of marine heterotrophic archaebacteria growing optimally at 100°C

Energetics of overall metabolic reactions of thermophilic and hyperthermophilic Archaea and Bacteria

(Edited in line with Psycho's editing )

This post has been edited by hypervalent_iodine: 7 November 2011 - 06:17 PM

[Psycho]

hypervalent_iodine, on 7 November 2011 - 06:08 PM, said:

Well gosh, if 30 years is the expiry date on scientific findings not currently disproved, one has to ask what on earth we're basing ourselves on? Archaic wordage or not, it doesn't take away from the fact that they were able to culture an organism, found in a hydrothermal vent at temperatures exceeding 250^oC.

Actually science does have an expiry date, it is when it's wrong.

Up to date science.

Odd though, because that paper is incorrect, what do they do with papers that are shown to be wrong, are they still available (online of course rather than in paper form) or are they removed?

I never said there weren't thermophilic bacteria, I said there weren't hyperthermophilic ones which is what is relevant if you go back to the original posters question.

Edit: Because hypervalent_iodine edited to add more links

This post has been edited by Psycho: 7 November 2011 - 06:25 PM

[hypervalent_iodine]

I suspect before you edited your previous post, the Archaea bit wasn't bolded and I missed it, hence why I changed my post

Also, I should point out that I changed my post because I altered how I perceived your opinion. The links were really just out of interest's sake, not because I'm trying to point out that you're wrong.

[Psycho]

hypervalent_iodine, on 7 November 2011 - 06:23 PM, said:

I suspect before you edited your previous post, the Archaea bit wasn't bolded and I missed it, hence why I changed my post

Also, I should point out that I changed my post because I altered how I perceived your opinion. The links were really just out of interest's sake, not because I'm trying to point out that you're wrong.

To be fair, that Nature paper is wrong, but I can easily see as it is published in Nature that it should be a valid source. It was obviously published before proper reproduction of the results were carried out. Currently the highest temperature any known organism can grow at is 122, though I think the archaea is call Strain 121, which is rather confusing.

This post has been edited by Psycho: 7 November 2011 - 06:45 PM

[insane_alien]

I can't find any definition of bacteria that says they can't exist at 121*C

I know that there isn't a known one, but i can't find anything saying that if it was that temperature then it wouldn't be a bacteria.

actually, Aquifex aeolicus and Geothermobacterium ferrireducens seem to be hyperthermophile bacteria

This post has been edited by insane_alien: 7 November 2011 - 07:07 PM

[Psycho]

insane_alien, on 7 November 2011 - 07:05 PM, said:

I can't find any definition of bacteria that says they can't exist at 121*C

I know that there isn't a known one, but i can't find anything saying that if it was that temperature then it wouldn't be a bacteria.

actually, Aquifex aeolicus and Geothermobacterium ferrireducens seem to be hyperthermophile bacteria

By definition a bacteria has to have a phospholipid bilayer and these aren't stable at extremely high temperatures +100oC though Geothermobacterium ferrireducens can grow at 100oC which is pretty good going, however the key definition of a hyperthermophile is that its optimum temperature for growth must be above 80oC and while these can survive above this it isn't their optimum.

In the case of archaea they have a monolayer which are very similar to bilayers except the fatty acid chains are joined in the middle of the membrane and while phospholipid bilayers bind the hydrocarbon chain to the the glycerol via an ester, archaea monolayers use an ether bond. This allows from lower levels of fluidity of the membrane making it more stable at high temperature however below 60oC archaea monolayers freeze, so they are very specialised for their environment.

[CharonY]

Actually, the optimum temperature for Aquifex and Geothermobacterium is somewhere between 80-90º.