Autolytic Enzyme System of Clostridium botulinum

Isolated cell walls of Clostridium botulinum type A strain 190L released an autolysin during autolysis of the cell walls. The autolysin was isolated from the cell walls, and partially purified 18.6‐fold by ammonium sulfate precipitation, chromatography on DEAE‐cellulose and gel filtration through Sephadex G‐100. The purified preparation of the autolysin showed 2 major and 2 minor protein bands on Polyacrylamide gel electrophoresis. Some properties of the autolysin were examined using SDS‐treated cell walls of the organisms as a substrate. The autolysin was active over a pH range of 6 to 8, with a maximum near pH 6.8. The lytic activity was stimulated by 10 −4 M each of Co ++ , Mg ++ and Ca ++ in the order, whereas it was inhibited markedly by Cu ++ . Mercaptoethanol (10 −4 –10 −3 M) significantly activated the lytic action. Trypsin and nagarse (10 μg/ml) also stimulated the lytic activity. The lytic spectrum of the autolysin toward the SDS‐treated cell walls obtained from various types of C. botulinum and C. perfringens indicated a relatively high specificity. After treatment with hot formamide the cell walls of C. botulinum increased in susceptibility to the autolysin.