Abstract
Treatment of strains of Escherichia coli with 0.25% phenethyl alcohol resulted in a reversible inhibition of DNA synthesis and cell division. Comparisons of sedimentation behavior for nucleoids isolated prior to and following phenethyl alcohol exposure indicated a dramatic increase in sedimentation velocity, from 3, 220S to 11, 770S. However, following extended phenethyl alcohol exposure, nucleoid sedimentation velocities began to decline spontaneously and to approach that of nucleoids obtained from untreated cultures. Following removal of phenethyl alcohol, DNA synthesis and cell division resumed and nucleoid sedimentation velocities returned to that of controls. Analysis of nucleoids isolated from phenethyl alcohol treated cultures demonstrated the presence of high levels of cosedimenting membrane proteins, indicating that nucleoids were not released from the membrane even though DNA synthesis had terminated. Results are discussed in relation to previously reported phenethyl alcohol-induced perturbations of various cellular processes.
