It has already been stated that "extremophiles are tight," and we all,
I'm sure, hold this to be true. But to be literal about it, the
tightest of the tight are undoubtedly barophiles: microorganisms that
thrive in extreme pressures. There aren't too many places on earth with
altitudes so high that the pressure is extremely low. However, the
oceans of this planet can get very, very deep. And with that depth
comes enormous pressure. The atmosphere exerts pressure on us
land-lubbers as well (one atmosphere, or "bar", of pressure, that is),
but for every ten meters one goes down into the ocean, that pressure is
doubled. The deepest trenches of the Pacific are 11 kilometers deep,
which comes out to be 1.1 kilobars (1,100 atmospheres) of pressure. In
black smokers such as the ones discussed in relation to thermophiles,
organisms live in pressures between 100 and 500 bars; but thermophiles
like these can survive, and may even thrive, in regular atmospheric
pressure. The true pressure lovers live in environments of between 700
and 800 bars, and can thrive at up to 1035 atmospheres of pressure, at
temperatures between 2 and 4 degrees Celsius (which, on top of being
barophiles, makes these organisms... come on now and say it with me...
that's right: psychrophiles, umm hmm).
The reason, as you must be wondering, why barophiles are so freakin
tight, is that in such extremely high pressure, they are basically
pushed and squeezed into dense, compact masses. Down at the bottom of
the ocean, living in 2.5 degrees celsius and feeding off of whatever
meager scraps of food fall down from the more thriving environments to
their north, live barophiles who are squeezed down to 15,400 lbs per
square inch (Postgate, 35). Just in case you skimmed over that last bit
without taking note: that's a single inch of bacteria, weighing 15
thousand, 4 hundred pounds! This is craziness, is what this is.
How, you are wondering, can this craziness be? The answers, however,
are not so easy coming. We humans certainly can't go down into these
environments to study barophiles, and it is very difficult to recreate
such highly pressurized spaces in laboratories. What we do know is that
these organisms are of the simplest kind: they are single celled, which
means that they don't have to worry about any complex organs collapsing
in on themselves. If an organism who lives in atmospheric pressure were
to be exposed to such high pressures, the molecules of their cell
membranes would be compressed so much that the membrane would cease to
be fluid; it would harden and the organism would therefore die.
However, it is thought that barophiles function in the exact same way as
non-barophilic organisms, they are simply adapted to their pressure:
such that, were they to be brought into a less-pressurized environment,
they would basically explode (it's simple physics, baby). Logically, it
would seem that if bacteria can be adapted to such environments, more
complex organisms (obviously of a slightly different sort than we are
familiar with) should be able to form in the same environments
(Postgate, 36). But, as I've stated, this is all pretty much
How bout them other extremophile types?
For more barophile information, check out this ArchaeaWeb site.