Do bacteria age? What is the longest-lived single bacterium?

It doesn't really work like that. With animals, the parent and the child are distinct. But bacteria reproduce by binary fission, meaning that each product of fission is half of the material--genetic and otherwise--of the "parent." So on one level, every bacterium is ancient, but on another level, they're all very young. Essentially the only difference in age between every bacteria on earth is the number of generations they've been through since the single common ancestor of all life.

Do bacteria age? What is the longest-lived single bacterium?
The longest living bacterium is around 250 million years...scientists found it 600 metres underground in some salt deposits in mexico...it achieved such longevity by becoming dormant...i.e. by shutting itself down...scientists re-awakened it...however, the age is controversial because some scientists believe it requires to awaken after a period of time to do house keeping functions...the rate of bacteria age is a function of energy consumption...scarcer the energy resource... slower is the rate of division...hence some bacteria in energy poor environments may divide only after hundreds of years...whereas others may divide in a matter of seconds in energy rich environments