DEATH OF BACTERIA IN GROWING CULTURE

Abstract

In growing cultures of Escherichia coli maintained under constant conditions, cell death followed by lysis is a rare phenomenon. If, however, the cells are chilled and centrifuged, approximately 5%/hour of a variety of labelled cellular components are released into the growth medium in an ultrafiltrable form. This release of labelled materials is interpreted as the autolysis of cells killed by the chilling and centrifugation procedures employed. Certain of these labelled materials will be reassimilated by the surviving organisms unless large pools of unlabelled materials are added. The study of artificial death of cells by these standard laboratory techniques allowed the design of experiments to show that death under suitable growth conditions is in fact uncommon.