Almost eternal: some bacterial spores are able to survive for several hundred years.

Clostridium botulinum
(spore-forming bacterium)

Clostridium botulinum is an anaerobic, Gram-positive, rod-shaped bacterium of the Clostridiaceae family that forms spores. Its toxin causes food poisoning (botulism) when eating tainted foodstuff. Additionally, Clostridium botulinum can trigger wound and infant botulism.

Transmission primarily occurs via contaminated food.

 

ยป Necessary spectrum of antimicrobial activity
Sporicidal