Growth and Survival of Bacteria

The survival of a bacterium in its natural habitat depends on its ability to grow at a rate sufficient to balance death caused by starvation and other natural causes such as temperature, pH, and osmotic fluctuations, as well as predation and parasitism. In discussing survival under extreme conditions, Shilo (1979) has drawn attention to the difference between (1) stable ecosystems (exemplified by the continuous high temperatures in thermal springs, continuous high salinity as in the Dead Sea, and continuous high hydrostatic pressure typical of the ocean depths), which are inhabited by organisms with narrow adaptations; and (2) fluctuating ecosystems (typified by marshes, swamps, and shallow lakes with pronounced diurnal fluctuations of physical and chemical parameters) that harbor organisms with a much greater versatility of response.