Inhibition of Air-Exposure Stress–Induced Autolysis in Clostridium perfringens by Zn2+

Clostridium perfringens is a pathogenic anaerobe that causes gas gangrene and food poisoning. Although autolysin-mediated reorganization of the bacterial cell wall is crucial for cell division, excessive autolysin activity induced by stressors can lead to cell lysis. In C. perfringens, air exposure is a significant stressor that causes cell lysis, and Acp (N-acetylglucosaminidase) is known to be a major autolysin. To further facilitate C. perfringens research, a technology to prevent air-induced cell lysis must be developed. This study investigated the role of Acp in air-induced autolysis and explored potential inhibitors that would prevent cell lysis during experimental procedures. Morphological analyses confirmed that Acp functions as an autolysin in C. perfringens, as acpdeficient strains exhibited filamentous growth. The mutants exhibited negligible autolysis under air-exposure stress, confirming the involvement of Acp in the autolytic process. We also evaluated the effects of various divalent cations on Acp activity in vitro and identified Zn2+ as a potent inhibitor. Brief treatment with a Zn2+- containing buffer induced dose-dependent cell elongation and autolysis inhibition in C. perfringens. These findings demonstrate that simple Zn2+ treatment before experiments stabilizes C. perfringens cells, reducing autolysis under aerobic conditions and facilitating various biological studies, except morphological analyses.