Previous studies on the leakage of radioactivity from glutamate-Cl* labeled Eschericbia coli cells in the presence of phenolic disinfectants were extended to involve cells labeled by growth on glucose-U-Ck4, acetate-C14, adenine-C", suUate-P, and phosphate-Pa*. In general, the phenolic disiafectants considered caused varying amounts of radioactivity to be released from the labeled cells. T h e phenol derivatives did not cause leakage of significant amounts of radioactivity from heat-treated cells, and cells exposed to n-butanol (which breaks the osmotic barrier) did release additional radioactivity when treated with p-chloro-m-xylenol or phenol, but the total counts released under the experimental conditions did not exceed that with further butanol treatment. Cells labeled with Pa*, once treated with p-chloro-m-xylenol, continued to release radioactivity in saline buffer but glucose-C~4-labeled cells did not. T h e amount of radioactivity released from variously labeled cells i n the presence of phenol, p-chloro-m-xylenol, or n-butanol was affected by temperature.
N PREVIOUS studies (l), i t was shown that IEscherichia coli, when labeled by incubation with glutamate-C1', would lose radioactivity when exposed t o phenolic disinfectants. This loss of radioactivity was proportional to the concentration of the phenol derivative and was caused by all of the phenols tested. It was assumed that the radioactivity lost could be due t o extrusion of cell contents through a damaged cell membrane. This hypothesis was further investigated by studying the release of radioactivity in the presence of phenol derivatives from E. coli labeled by growth on a number of radioactive compounds.
METHODS AND MATERIALS
Materials.--Only reagent grade chemicals were used and biochemicals were obtained from Nutritional Biochemicals Corp. or the California Corp. for Biochemical Research. The radioactive compounds were obtained either from the California Corp. for Biochemical Research, New England Nuclear Corp., or Abbott Laboratories. Tt ' labeled organic compounds had the following spea IIK activities (mc./mmole): glucose-U-C1', 4; sodium acetate-l,2-C14, 10.5; adenine-8-Ck4, 14.4; sodium glutamate-3,4-C14, 2.3. Phosphorus32 was purchased as NaH2PO4 in solution with an activity of 10 pc./5 ml., and sodium sulfate-S= was obtained with an activity of 50 pc./5 ml. The organic compounds were dissolved in distilled water t o give a concentration of 2 pc./ml. A number of the phenol derivatives were a gift of the Ottawa Chemical Co., Toledo, Ohio.
Labeling of Bacteria.-The procedure for labeling Received March 29. 1962. from the Colleee of Pharmacv. _ .