|MadSci Network: Microbiology|
Howdy K -
You have asked an interesting question.
Bacteria differ from us in a number of ways. They are single-celled organisms that have a simpler structure than the cells that make up our bodies. However, like our cells, bacteria need a source of food, vitamins and minerals to 'live.' They certainly need these things to actively grow and divide. When the going gets rough, however, most species of bacteria can enter a quiet state where they do very little. They are still alive, just not very active. Many microbes can survive for weeks or longer by entering this "quiescent state." In addition, two genuses of bacteria, Bacillus, and Clostridium have an added mechanism of survival -- they undergo a process of sporulation when conditions become less than ideal. The spore is a tough little capsule that contains the DNA of the microbe. It is not actively "alive" but has the potential to germinate into a living cell when conditions improve. Spores can survive for years before germinating into living cells again.
On the flip side, some species of bacteria can divide at a maximal rate of once every 20 minutes under the best of conditions. This means that a single cell will give rise to two daughter cells so, in a sense, you can think of the original cell as having a life span of 20 minutes!
For more information about microbes, take a visit to the Microbe Zoo
-L. Bry, MadSci Admin
Try the links in the MadSci Library for more information on Microbiology.