Effect of Time and Temperature upon Survival of Escherichia coli in Sodium Chloride.

Abstract

Suspensions of E. coli in 4.6 [image] NaCl stored under conditions which preclude cell division undergo at first a rapid decline in viable cells, but as the storage interval is extended the death rate continously decreases until eventually it becomes negligible. Cells that endure the period of rapid decline are able to maintain themselves in the saline for long periods. This resistance is not heritable; once the cells are removed from the saline their resistance to it is lost. Generally, survival is better at higher storage temperatures. Also, holding suspensions at a relatively high temperature (+2[degree] or -9[degree]C) prior to subsequent storage at a low temperature (-22[degree]C) improves survival at the low temperature. These data suggest that tolerance to 4.6 [image] NaCl is acquired while the cells reside in the saline and does not exist preformed in a segment of the original population.