Temperature dependence of sex-factor maintenance in Escherichia coli K-12

Wild-type sex factors of Escherichia coli K-12 can be cured from host cells by growth at temperatures above 42 C. This phenomenon is obscured by reinfection of cured cells if the culture is allowed to reach cell densities above 10(5)/ml. The rate of episome loss is dependent on the genetic (chromosomal) background of the host.