6 ms·

Would bacteria from that region tolerate normal atmospheric pressures?

by RenRav 8y ago

tejtm 8y ago
Eight orders of magnitude pressure difference, not likely in one generation.
- raverbashing 8y ago
  8 orders is crazy! Though to be honest I think unicellular organisms take pressure differences much more easily than multicellular orgs.
- sgt101 8y ago
  well it's 1000 times which in math speak is often described as three orders as in 10, 100, 1000
- tejtm 8y ago
  yep that is wrong. mistook 1 *10^8 Pa as, times "pressure atmosphere". it is only three orders of magnitude greater psi
  - ncmncm 8y ago
    Three orders of magnitude qualifies as "a hell of a lot" in any reasonable estimate.
travisoneill1 8y ago
I would speculate that they could. Pressure should be a lot less significant at the bacterial scale. Sperm whales can survive at the surface and deep ocean, and are fairly closely evolutionary related to us so the pressure resistance is probably coming from large scale morphological changes and not structural differences at the cellular level.
- pfortuny 8y ago
  Is pressure relevant to a molecular membrane? I mean: it is not a sheet of metal ee are talking about but a layer of proteins...
  - gus_massa 8y ago
    The internal part is at the same pressure, so they probably cancel. I'm more worried about the level of oxygen disolved in the water, but IANAB.
  - marmaduke 8y ago
    I’d guess pressure due to ionic concentrations is more relevant
  - gilleain 8y ago
    A layer of lipid, really, although there are certainly proteins in the membrane. I've no idea about pressure adaptation, but a quick google gives this (open) paper that looks useful: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5487899/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5487899/ From the abstract: >Maintenance of the functionality of the membrane during changing environmental conditions relies on the cell’s potential to rapidly adjust the lipid composition of its membrane So in other words, bacteria at depth seem to use a particular mix of lipids in their membrane. Since things have to cross the membrane it makes sense to me that it has to be stiffer or less so at different pressures.
    - pfortuny 8y ago
      Thanks!
  - HarryHirsch 8y ago
    Pressure does affect chemical equilibria, the canonical example is that above a certain pressure calcium carbonate actually becomes soluble. That's why you don't find hard-shelled organisms at the bottom of the ocean. Kinetics are affected, too, because the energy of transition states varies with the pressure. That said, they grew the bacteria from their samples at ambient pressure without problems.
darkpuma 8y ago
If they don't have compressible gasses in them, I don't see why they shouldn't. There would be gas dissolved in the water inside them that would have to be dealt with I suppose. But the water itself is damn near in-compressible. The volume of water inside them down there would be the same up here. Decompression explosions like the Byford Dolphin accident happen when compressible gasses are involved. Compressed gasses are like springs that store huge amounts of energy. This is why pneumatics have very energetic failure modes while hydraulics are relatively safe (injection wounds and oil fires notwithstanding)
- ncmncm 8y ago
  Bi-layer membranes, such as cell membranes and walls of organelles, are squeezed together, so may be thinner and stiffer. It would not be surprising if some species could not adapt to lower pressure, just as we are ill-adapted to vacuum.
  - darkpuma 8y ago
    I'm not a biologist but I believe the pressures should be equalized inside and out. The problem humans have with pressure is mostly related to humans being filled with gasses. Contrary to popular belief, humans don't explode when exposed to a vacuum. The fleshy bits hold together just fine, but trying to hold your breath would rupture your lungs, forcing you to exhale, which causes you to asphyxiate. There have been a few cases where isolated body parts were depressurized, which caused painful swelling but no permanent damage. I think it's likely that swelling occurred because the rest of the body was still pressurized, in effect squeezing the body out into the unpressurized portion of the suit. This is similar to one of the failure modes of old style diving bell helmets where depressurization of the helmet could force a diver's body into the helmet.
    - chmod775 8y ago
      NASA/USAF put (whole) dogs in a vacuum: https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19660005052.pdf https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/196600... The paper is pretty short read. They reference another study that was conducted with primates, but I'm not able to find it at this moment. Here's the part about primates: "After decompression to approximately 1 mm. Hg absolute, the squirrel monkeys appeared to lose consciousness sooner than the dogs. As with dogs, they had both tonic and clonic seizures shortly after unconsciousness and this progressed to flaccid paralysis. Subcutaneous emphysema and swelling occurred, but was not as marked. During and following recompression to ground level, the monkeys recovered similarly but seemed to exhibit staggering and disorientation for a longer period. Two monkeys died as a result of these low pressure exposures, while no dogs died from exposures that were less than 120 seconds. [...]" It's under "Observations made on small primates" on page 7.
Pharmakon 8y ago
were able to efficiently degrade n-alkanes under conditions simulating the deep sea, as did a reference Oleibacter strain cultured at atmospheric pressure. So yes, it seems at least some of them can.

Would bacteria from that region tolerate normal atmospheric pressures?

by RenRav 8y ago

Would bacteria from that region tolerate normal atmospheric pressures?

tejtm 8y ago

Eight orders of magnitude pressure difference, not likely in one generation.

raverbashing 8y ago
8 orders is crazy! Though to be honest I think unicellular organisms take pressure differences much more easily than multicellular orgs.
sgt101 8y ago
well it's 1000 times which in math speak is often described as three orders as in 10, 100, 1000
tejtm 8y ago
yep that is wrong. mistook 1 *10^8 Pa as, times "pressure atmosphere". it is only three orders of magnitude greater psi
- ncmncm 8y ago
  Three orders of magnitude qualifies as "a hell of a lot" in any reasonable estimate.

travisoneill1 8y ago

I would speculate that they could. Pressure should be a lot less significant at the bacterial scale. Sperm whales can survive at the surface and deep ocean, and are fairly closely evolutionary related to us so the pressure resistance is probably coming from large scale morphological changes and not structural differences at the cellular level.

pfortuny 8y ago
Is pressure relevant to a molecular membrane? I mean: it is not a sheet of metal ee are talking about but a layer of proteins...
- gus_massa 8y ago
  The internal part is at the same pressure, so they probably cancel. I'm more worried about the level of oxygen disolved in the water, but IANAB.
- marmaduke 8y ago
  I’d guess pressure due to ionic concentrations is more relevant
- gilleain 8y ago
  A layer of lipid, really, although there are certainly proteins in the membrane. I've no idea about pressure adaptation, but a quick google gives this (open) paper that looks useful: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5487899/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5487899/ From the abstract: >Maintenance of the functionality of the membrane during changing environmental conditions relies on the cell’s potential to rapidly adjust the lipid composition of its membrane So in other words, bacteria at depth seem to use a particular mix of lipids in their membrane. Since things have to cross the membrane it makes sense to me that it has to be stiffer or less so at different pressures.
  - pfortuny 8y ago
    Thanks!
- HarryHirsch 8y ago
  Pressure does affect chemical equilibria, the canonical example is that above a certain pressure calcium carbonate actually becomes soluble. That's why you don't find hard-shelled organisms at the bottom of the ocean. Kinetics are affected, too, because the energy of transition states varies with the pressure. That said, they grew the bacteria from their samples at ambient pressure without problems.

darkpuma 8y ago

If they don't have compressible gasses in them, I don't see why they shouldn't. There would be gas dissolved in the water inside them that would have to be dealt with I suppose. But the water itself is damn near in-compressible. The volume of water inside them down there would be the same up here. Decompression explosions like the Byford Dolphin accident happen when compressible gasses are involved. Compressed gasses are like springs that store huge amounts of energy. This is why pneumatics have very energetic failure modes while hydraulics are relatively safe (injection wounds and oil fires notwithstanding)

ncmncm 8y ago
Bi-layer membranes, such as cell membranes and walls of organelles, are squeezed together, so may be thinner and stiffer. It would not be surprising if some species could not adapt to lower pressure, just as we are ill-adapted to vacuum.
- darkpuma 8y ago
  I'm not a biologist but I believe the pressures should be equalized inside and out. The problem humans have with pressure is mostly related to humans being filled with gasses. Contrary to popular belief, humans don't explode when exposed to a vacuum. The fleshy bits hold together just fine, but trying to hold your breath would rupture your lungs, forcing you to exhale, which causes you to asphyxiate. There have been a few cases where isolated body parts were depressurized, which caused painful swelling but no permanent damage. I think it's likely that swelling occurred because the rest of the body was still pressurized, in effect squeezing the body out into the unpressurized portion of the suit. This is similar to one of the failure modes of old style diving bell helmets where depressurization of the helmet could force a diver's body into the helmet.
  - chmod775 8y ago
    NASA/USAF put (whole) dogs in a vacuum: https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19660005052.pdf https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/196600... The paper is pretty short read. They reference another study that was conducted with primates, but I'm not able to find it at this moment. Here's the part about primates: "After decompression to approximately 1 mm. Hg absolute, the squirrel monkeys appeared to lose consciousness sooner than the dogs. As with dogs, they had both tonic and clonic seizures shortly after unconsciousness and this progressed to flaccid paralysis. Subcutaneous emphysema and swelling occurred, but was not as marked. During and following recompression to ground level, the monkeys recovered similarly but seemed to exhibit staggering and disorientation for a longer period. Two monkeys died as a result of these low pressure exposures, while no dogs died from exposures that were less than 120 seconds. [...]" It's under "Observations made on small primates" on page 7.

Pharmakon 8y ago

were able to efficiently degrade n-alkanes under conditions simulating the deep sea, as did a reference Oleibacter strain cultured at atmospheric pressure. So yes, it seems at least some of them can.