Mechanism of Curcumin Mediated Photodynamic Sterilization on Clostridium perfringens

To achieve the control of foodborne pathogenic bacteria Clostridium perfringens by non-thermal technology, curcumin was used as the photosensitizer to explore its inhibitory mechanism on C. perfringens. The bactericidal effect of different curcumin concentrations on C. perfringens was investigated. The cell morphology after curcumin treatment was investigated through scan electron microscopy. The integrity of the cell membrane was analyzed by confocal laser scanning microscope and leakage of extracellular macromolecules. The oxidative damage of C. perfringens was determined by ROS analysis. The results indicated that curcumin showed a strong photodynamic inactivation against C. perfringens. C. perfringens was completely killed when curcumin was used at a concentration of 20 μmol/L for 10 minutes. Cytotoxic ROS was generated in this process, which caused the damage of DNA and proteins, cell membrane rupture and leakage of cellular contents, ultimately leading to cell death. These findings gave support for the development of photodynamic sterilization technology in low-temperature meat products.