ABSTRACT
The very efficiency with which bacteria are capable of utilizing available nutrient and energy sources ensures that these will be quickly depleted. Bacteria may therefore seldom encounter conditions that sustain prolonged balanced growth, and most probably alternate between prolonged periods of starvation and sporadic growth. Cells can also respond to changes in their external environment by undergoing genetic changes. In this respect, the high population numbers and rapid growth rates of bacteria have in fact been exploited for selection of mutants with new metabolic capabilities. Continued exposure to different growth conditions can select for mutants that have growth capabilities that are enhanced over the parental strain. The growth rate decreases and populations stop their exponential increase in biomass. This constitutes a period of transition between exponential growth and the onset of what has become known as the stationary phase. Bacterial genera, such as Bacillus and Myxococcus, have developed elaborate mechanisms to maintain viability during starvation.
