Lysis induced by sodium ion and its relation to lytic enzyme systems in Clostridium saccharoperbutylacetonicum.

Growing Clostridium saccharoperbutylacetonicum was lysed by sodium ion concentrations above 0.1 M (maximum effect at 0.3 M). The rate of lysis depended on the age of the culture. The most rapid lysis occurred in organisms from logarithmically growing cultures which were incubated for 3 to 5 h; organisms from stationary phase cultures were completely resistant to Na+-induced lysis. Sodium ioninduced lysis was related to autolysis of the organisms and was greatly affected by pH and temperature. The optimum pH was about 6.0, and the optimum temperature 35 "C. Various chemical inhibitors, including known enzyme inhibitors (such as Cu2+ and p-chloromercuribenzoate) and fixative agents (such as forrnalin and glutaraldehyde), inhibited the lysis, while organisms whose growth had been inhibited by antibiotics such as tetracycline, were also resistant to Na+-induced lysis. The lysate produced by Na+-treatment itself had lytic activity on isolated walls, thought to be due to its content of autolysin. About 30 to 60 min after mitomycin C treatment (which induced the production of the phage tail-like bacteriocin clostocin 0), the organisms were temporarily resistant to Na+-induced lysis. However the organisms reverted to the state of high sensitivity to Na+ when clostocin 0-associated endolysin was produced. We suggest that Naf-induced lysis is due to the action of wall lytic enzymes such as autolysin and clostocin 0-endolysin.