[Characteristics of defective lysogeny in Streptomyces chrysomallus]

When Streptomyces chrysomallus 2703 grows on solid media, lytic zones appear in the form of negative colonies which are not caused by the virulent phage. The material from these colonies and the cultural broth of S. chrysomallus 2703 were examined by electron microscopy. Four different morphological types of particles were revealed, three of which were defective phage particles (tails). Particles of the fourth type had a regular hexagonal shape and a diameter of 200A. The particles prevailed in all of the preparations. Their origin is discussed. S. chrysomallus in considered as a poly- and defective lysogenic culture.