# How Do Thermophilic Bacterial Survive? **URL:** \ **Category:** Factual Questions\ **Created:** [August 19, 2011, 8:03am UTC](https://boards.straightdope.com/t/how-do-thermophilic-bacterial-survive/593296 "2011-08-19T08:03:11Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![YourAdHere](https://avatars.discourse-cdn.com/v4/letter/y/65b543/32.png) [@YourAdHere](https://boards.straightdope.com/u/YourAdHere)\ **Post date:** [August 19, 2011, 8:03am UTC](https://boards.straightdope.com/t/how-do-thermophilic-bacterial-survive/593296/1 "2011-08-19T08:03:11Z")
How do thermophilic and hyperthermophilic bacteria (e.g. - the bacteria that live around hot springs or the volcanic vents on the ocean floor) survive such high temperatures? I know some of them form some sort of protective envelope as a response to a stimulus of high heat, but are those the ones that actually _thrive_ at such temperatures? Why is it that they don’t get “cooked” like some other organic matter does when in water at such temperatures? What is it that enables them to survive such temps while other bacteria would be killed? Would most hyperthermophilic bacteria die in tepid water? I apologize if this question could be easily answered by Google, or if it betrays my utter lack of scientific knowledge / understanding. I actually did look around a bit, but couldn’t find much. I am hoping there will be someone here to give a relatively thorough explanation in somewhat “layman’s terms”. Thank you in advance ---
**Author:** ![Norse](https://avatars.discourse-cdn.com/v4/letter/n/a9adbd/32.png) [@Norse](https://boards.straightdope.com/u/Norse)\ **Post date:** [August 19, 2011, 8:32am UTC](https://boards.straightdope.com/t/how-do-thermophilic-bacterial-survive/593296/2 "2011-08-19T08:32:55Z")
> [@YourAdHere](#): > > What is it that enables them to survive such temps while other bacteria would be killed? One very important factor is that their enzymes (and other proteins) don’t denature and lose their function at these temperatures. Pronteins found in mesophilic organisms (including higher animals) first lose their function and then denature fully at temps between 40-70 degrees C. Easily observable examples are the change in the egg white when you cook it, or the color change from red to grey in meat that is heated above ~55 degrees C. Prospecting for heat-tolerant enzymes that can be used in industry is something quite a few Icelandic scientists are doing around their hot springs. ---
**Author:** ![mac\_bolan00](https://avatars.discourse-cdn.com/v4/letter/m/b3f665/32.png) [@mac\_bolan00](https://boards.straightdope.com/u/mac_bolan00)\ **Post date:** [August 19, 2011, 8:35am UTC](https://boards.straightdope.com/t/how-do-thermophilic-bacterial-survive/593296/3 "2011-08-19T08:35:48Z")
their blood is different too: copper instead of iron. ---
**Author:** ![Norse](https://avatars.discourse-cdn.com/v4/letter/n/a9adbd/32.png) [@Norse](https://boards.straightdope.com/u/Norse)\ **Post date:** [August 19, 2011, 8:40am UTC](https://boards.straightdope.com/t/how-do-thermophilic-bacterial-survive/593296/4 "2011-08-19T08:40:44Z")
> [@YourAdHere](#): > > […] thermophilic and hyperthermophilic _bacteria_ […] > [@mac\_bolan00](#): > > […] blood […] :dubious: (is this a whoosh?) ---
**Author:** ![mac\_bolan00](https://avatars.discourse-cdn.com/v4/letter/m/b3f665/32.png) [@mac\_bolan00](https://boards.straightdope.com/u/mac_bolan00)\ **Post date:** [August 19, 2011, 9:01am UTC](https://boards.straightdope.com/t/how-do-thermophilic-bacterial-survive/593296/5 "2011-08-19T09:01:59Z")
no, just an aside. i was thinking of mollusks living near vents, not bacteria. 😃 ---
**Author:** ![YourAdHere](https://avatars.discourse-cdn.com/v4/letter/y/65b543/32.png) [@YourAdHere](https://boards.straightdope.com/u/YourAdHere)\ **Post date:** [August 19, 2011, 9:18am UTC](https://boards.straightdope.com/t/how-do-thermophilic-bacterial-survive/593296/6 "2011-08-19T09:18:07Z")
> [@Norse](#): > > One very important factor is that their enzymes (and other proteins) don’t denature and lose their function at these temperatures. Pronteins found in mesophilic organisms (including higher animals) first lose their function and then denature fully at temps between 40-70 degrees C. Easily observable examples are the change in the egg white when you cook it, or the color change from red to grey in meat that is heated above ~55 degrees C. > > Prospecting for heat-tolerant enzymes that can be used in industry is something quite a few Icelandic scientists are doing around their hot springs. So, is what you’re saying that it basically boils ( that’s right, I went there) down to the fact that their enzymes don’t break down in high heat? That seems so simple and obvious now. Thank you ---
**Author:** ![YourAdHere](https://avatars.discourse-cdn.com/v4/letter/y/65b543/32.png) [@YourAdHere](https://boards.straightdope.com/u/YourAdHere)\ **Post date:** [August 19, 2011, 9:23am UTC](https://boards.straightdope.com/t/how-do-thermophilic-bacterial-survive/593296/7 "2011-08-19T09:23:14Z")
> [@mac\_bolan00](#): > > no, just an aside. i was thinking of mollusks living near vents, not bacteria. 😃 Yeah, actually, about those shrimp and stuff living around there: Do they actually live in the same high temp water that the bacteria do? ISTR once hearing that, although in close proximity, the water they lived in is nowhere near as hot. Is that true, or not? ---
**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\ **Post date:** [August 19, 2011, 9:29am UTC](https://boards.straightdope.com/t/how-do-thermophilic-bacterial-survive/593296/8 "2011-08-19T09:29:37Z")
> [@mac\_bolan00](#): > > no, just an aside. i was thinking of mollusks living near vents, not bacteria. 😃 But those mollusks don;t have blood that is any different to molluscs living elsewhere. Most mollusks possess hemocyanin. > [@YourAdHere](#): > > So, is what you’re saying that it basically boils down to the fact that their enzymes don’t break down in high heat? It’s not just the enzymes. All their proteins are heat tolerant. You literally can not cook them. > [@](#): > > about those shrimp and stuff living around there: Do they actually live in the same high temp water that the bacteria do? ISTR once hearing that, although very close, the water they lived in is nowhere near as hot. Is that true, or not? Yeah, it’s true. IIRC They can survive in water up to 80oC for short periods of several seocnds, but they can’t stand temperatures that high for very long. ---
**Author:** ![mac\_bolan00](https://avatars.discourse-cdn.com/v4/letter/m/b3f665/32.png) [@mac\_bolan00](https://boards.straightdope.com/u/mac_bolan00)\ **Post date:** [August 19, 2011, 9:32am UTC](https://boards.straightdope.com/t/how-do-thermophilic-bacterial-survive/593296/9 "2011-08-19T09:32:31Z")
freely available in wiki, explained in layman’s terms. sea water at the ocean floor is around 2 degrees centigrade. the hysdrothermal water coming out could range from 60 degrees to 460 degrees. water usually comes out as a “supercritical” fluid. you don’t expect life forms to survive 3-figure temperatures but they can proliferate at the boundaries. and the majority of these organisms are chemosnthetic organisms – they rely on chemicals they absorb, instead of using the powers of the sun. and smoker vents abound with chemicals. some organisms here depend on oxygen produced by photosynthetic organisms, other are anaerobic. ---
**Author:** ![YourAdHere](https://avatars.discourse-cdn.com/v4/letter/y/65b543/32.png) [@YourAdHere](https://boards.straightdope.com/u/YourAdHere)\ **Post date:** [August 19, 2011, 11:07am UTC](https://boards.straightdope.com/t/how-do-thermophilic-bacterial-survive/593296/10 "2011-08-19T11:07:48Z")
Thank you for all the replies. Sorry for asking a question wiki could have answered. ---
**Author:** ![Smeghead](https://avatars.discourse-cdn.com/v4/letter/s/f1d935/32.png) [@Smeghead](https://boards.straightdope.com/u/Smeghead)\ **Post date:** [August 19, 2011, 11:35am UTC](https://boards.straightdope.com/t/how-do-thermophilic-bacterial-survive/593296/11 "2011-08-19T11:35:47Z")
Incidentally, for those who aren’t aware of this, the DNA polymerase from one of these bacteria, _Thermophilis aquaticus_, is arguably the most important enzyme on earth for biological researchers. It is the basis for all PCR reactions done for the last umptey-ump years. PCR involves repeated thermal cycling, including one temperature high enough to denature everything. Before Taq polymerase was used, researchers would have to add fresh polymerase to the reaction every cycle, which was horribly inefficient. Then someone figured out that Taq polymerase could survive the hot part of the cycle, and the PCR revolution began. ---
**Author:** ![njtt](https://avatars.discourse-cdn.com/v4/letter/n/ecd19e/32.png) [@njtt](https://boards.straightdope.com/u/njtt)\ **Post date:** [August 19, 2011, 2:46pm UTC](https://boards.straightdope.com/t/how-do-thermophilic-bacterial-survive/593296/12 "2011-08-19T14:46:58Z")
Some like it hot. ---
**Author:** ![Autolycus](https://avatars.discourse-cdn.com/v4/letter/a/22d042/32.png) [@Autolycus](https://boards.straightdope.com/u/Autolycus)\ **Post date:** [August 20, 2011, 8:12am UTC](https://boards.straightdope.com/t/how-do-thermophilic-bacterial-survive/593296/13 "2011-08-20T08:12:10Z")
Wait so those don’t bacteria don’t live in the super-hot water, but only around it? ---
**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\ **Post date:** [August 20, 2011, 8:25am UTC](https://boards.straightdope.com/t/how-do-thermophilic-bacterial-survive/593296/14 "2011-08-20T08:25:15Z")
> [@Autolycus](#): > > Wait so those don’t bacteria don’t live in the super-hot water, but only around it? Depends what you mean by super hot. Some thermophiles will live happily in water up to 120oC. That is well above boiling. Many will survive in water up to 200oC for several seconds. As already noted, the water coming from the vents doesn’t actually exist temperatures much above boiling for more than a few seconds.