Chapter 5 Three hundred years of bacterial motility

Where have we come since the early descriptions of bacterial swimming and behavior? Some extremely detailed and perceptive descriptions at the turn of the last century have hardly been improved upon. However the advent of molecular genetics and improved microscopy has led to a detailed molecular description of the sensory-transducing processes leading to a behavioral response. We know that the flagellum is a complex structure, the genes being transcribed in a strict hierarchy and their products assembled in order. Understanding this has helped identify a new bacterial export system possibly important in virulence. We know now that the flagellar motor rotates-the only known rotary structure in biology-driven by protons (sodium ions are used to drive rotation in bacteria living in high salt or alkaline environments). Where do we go from here? There are still a series of answers needed ranging from "How does the molecular motor work?" to "What is the role of motility in the natural environment?". Perhaps the most obvious change over the years has been that early data came from a very few individuals quietly working, usually alone and more or less in isolation, whereas today the research is being carried out by large research groups producing a constant flow of data. However, even with the number of large groups, major advances still tend to come from a few perceptive individuals (with the help sometimes of a major advance in technology). © 1997 Elsevier Inc. All rights reserved.