Global systems approach to bacterial physiology: protein responders to stress and starvation

For over a century microbial physiologists have been studying how bacteria adapt and grow in their environment. A tremendous amount of information has been obtained by two quite different approaches. One approach studies how the bacterium as a biological system competes with other bacterial species for the limiting nutrient supply [1-4] and also how ~ s,o~rvives deleterious environmental conditions [2-5]. Another approach studies the individual enzymes necessary for the cell to survive or compete successfully in its environment and how the individual genes for these enzymes are regulated (for example, see [6,7]). A more recent strategy, the global systems approach, has been developed which helps to link these two classical approaches by allowing the investigator to study the response of many genes/ proteins simultaneously. By this strategy one identifies the sets of genes/proteins which respond to an environmental condition and then uncovers the regulatory elements that unite these sets of genes./ proteins. For some multigene systems this approach has helped to elucidate in molecular terms