[Characterization of bacteriophages of Clostridium novyi type A (author's transl)].

Four bacteriophages of Clostridum novyi type A (PFö, P5771, PA1350e and P19402) were examined. The phages were spontaneously released to the culture medium in titers of 10(6) to 10(8) pfu/ml at the end of the bacterial growth of the donor strain. The phage titer could be increased to 10(9) to 10(12) pfu/ml by growing the phages in the culture of the indicator strain C. novyi 5771/HS 10. These high titered phage suspensions were used for morphological studies and for the production of anti-phage-sera. The phages of C. novyi were unstable and lost most of their infectivity within 24 h. Lyophilizing the phages in glutamate medium seemed to be one possible way of partially stabilizing these phages. Phages PFö, P5771, PA1350e and P19402 were similar in morphology and size, in antigenic pattern and in plaque morphology. Phage PA1350e was stabile only at pH 7 and below 40 degrees C for a short time. It was inactivated at 50 degrees C within 20 min, at 55 degrees C and at 60 degrees C in 4 min.