SURVIVAL OF THE TEMPERATE ACTINOPHAGE PHI-C31 AND STREPTOMYCES-LIVIDANS IN SOIL AND THE EFFECTS OF COMPETITION AND SELECTION ON LYSOGENS

Lysogenic infections were demonstrated in microcosms of sterile soil i noculated with Streptomyces lividans and the phi C31 derivative, KC301 , in free state or via lysogenized hosts. Intermittent soil mixing cau sed liberation of KC301 due to lysis of germinating lysogenized and un infected spores. The presence of lysogenized hosts ensured that KC301 was maintained at a constant density. The lysogen S. lividans TK24 (KC 301) achieved a population density lower than that of its non-lysogeni zed counterpart. Thiostrepton in the soil did not select for the thios trepton resistance gene of KC301. The long-term survival in soil of a temperate actinophage was demonstrated.