How long can a bacterium survive?

How long can bacteria like escheria coli survive in the open, at STP and average humidity? Can they be freeze-dried and then revived? What sort of storage media would a microbiologist use to transport a sample of bacteria?

Depends. Certain bacteria are capable of forming spores when conditions become adverse. A spore is a capsule that contains the bacteria’s genetic material and a couple of enzymes. Think of it as a bacterial egg although that’s only an analogy. Once the spore is formed, the bacterium dies and the spore stays dormant until conditions get good enough for it to start building a new bug. How long can it last? According to my microbiology prof, they isolated some spores from the inner wrappings of a Egyptian mummy believed to be around 3000 years old. They grew. Hope this helps.


Some theorise that bacteria and single cell org’s can survive not only interplantarly travel (i.e. mars to earth) but also inter-steller travel - these distances are long - were talking about al least 4.5 years traveling at the SOL to the nearest one. The hitchhiker would have to be protected in a asteriod to shield it from radiation and big enought that the center remains cool during re-entry

A bacterium can survive for approximately 3.8 billion years and counting.


3.8 billion years sounds a little long to me, though… afte 3.8 billion years, wouldn’t the genetic material be really, really corrupt?

Every baterium alive is 3.8 billion years old. When a bacteria reproduces, it merely splits in half. Which one is the new one? Neither. They are both part of the old one, and grow by incorporating new material. The DNA in the daughter cells is half old and half new. Continue the process for a few billion years, and you’ve got gazillions of bacteria that are all the same age. In fact, they are all clones of each other. Any differences you might notice are merely the result of copying errors.


E. coli can survive indefinitely at -80 degrees centigrade in 80% glycerol (this is how we store our stocks). In the open, they do not sporulate, but can live for at least a few hours on an open benchtop without food. They are much more stable than viruses, which usually degrade rapidly with ambient UV light.

Interestingly enough, I once heard that they cultured Yersinia pestis (which causes the plague) from the Roman baths in Bath, England. Apparently, there are centuries of silt on the bottom of the baths, and they found the bacteria while cleaning out the silt and got to the Middle Ages-era level. Even though to the best of my knowledge Y. pestis doesn’t sporulate (it is actually a Gram negative enteric, making it somewhat similar to E. coli), the bacteria found in the silt was still viable and thought to even be pathogenic.