Bacteriophages of Nocardia asteroides

101 Nocardia strains from different species and different sources were examined with respect to their lysogeny. 18 phages from 17 Nocardia asteroides strains could be isolated, purified, and propagated. All phages were released spontaneously. Induction experiments with mitomycin C and UV-rays brought no practicale advantages. Using 14 of the 18 phages, 38 of the 101 Nocardia strains tested could be grouped into 18 phage patterns. Nearly all of the typable strains belonged to the species Nocardia asteroides.