Back in the 1990s, at the turn of the century, scientists discovered a tiny brine pocket in a salt crystal within an underground cavern used to store nuclear waste. This pocket contained a droplet of water with trapped bacterial spores. The analysis of these spores revealed that they represented two bacterial species, Bacillus marismortui and Virgibacillus pantothenticus, which have likely remained dormant but viable for approximately 250 million years! To date, these spore samples hold the documented record for how long a living cell can remain viable in a state of dormancy.
Although some scientists have expressed skepticism about this discovery, noting that reports of ancient bacteria found in rock, coal, and Egyptian temples have not stood up to scientific scrutiny, similar findings have been made for other organisms. For instance, in one subsequent study, 100-million-year-old samples of dormant aerobic bacteria from ancient sea-floor sediments were successfully brought to life—providing another demonstration of the exceptional longevity of dormant microbial cells.
The question, however, stands regardless of any imaginable skepticism: For how long can an organism remain viable in a state of dormancy? If we find a way to protect biological molecules from damage caused by oxygen or radiation, can “simple” organisms, such as bacteria, remain viable forever?
While the answer to this question remains to be found (ironically, supported by research funded through grants that typically last about 5 years), let’s consider several documented examples of these longevity:
- Human oocytes – remain dormant but viable for up to ~40 years …
(to be continued)