Chapter 27 : Why I Am Amazed by Simple Things

Abstract:

In this section the author expresses his primordial awe for one of the simplest experiments in bacterial physiology that is done over and over in laboratories. It is the measurement of the growth of a bacterial culture in a liquid medium. One can get an instantaneous reading simply by determining the turbidity of the culture at different times using a common light-measuring device such as a colorimeter. In addition to enjoying the delights of Copenhagen, the author became involved in research on bacterial growth physiology using the enteric bacterium Salmonella typhimurium. The increase in the number of cells, on the other hand, did not proceed at the new rate until quite some time later. Cultures were set up in a collection of different media that supported various growth rates, from the slowest to the fastest attainable in that laboratory. It was found that the concept that the polymerizing machinery of bacteria performs at unit rates is also true for the biosynthesis of DNA, RNA, and cell wall constituents. This finding demonstrates the economy that bacteria exhibit in adapting to different growth environments.