Under
Pressure
Under
Pressure
Pressure is very important to animals – if the air pressure drops too low then they may not have enough oxygen and will dies. High pressure is not much problem to air-breathers but for life underwater it can be significant. Pressure at sea level is called 1 atmosphere and is equal to about 15 pounds of pressure per square inch of surface. If we travel 10 metres underwater we would find pressure of two atmospheres, at 20 metres we would experience three atmospheres and so on – eventually we would be crushed.
Bacteria do not seem to suffer from these problems – high-pressure research is extremely difficult but normal bacteria (E. coli) that live in the human gut have been shown to survive pressures of 500 atmospheres and most bacteria from deep underwater can survive the relatively low pressures found under normal lab conditions.
Bacteria also seem not to experience problems in low pressure – as long as the pressure is sufficient to maintain the film of water that they need to live and replicate.