Li Yali, Xu Yi, Liao Qiaoming, Xie Mengmeng, Tao Han, Wang Hui-Li
School of Food and Bioengineering, Hefei University of Technology, Hefei, 230009, China.
Engineering Research Center of Bio-process, Ministry of Education, Hefei University of Technology, 193 Tunxi Road, Hefei, 230009, China.
Microb Biotechnol. 2021 Mar;14(2):692-707. doi: 10.1111/1751-7915.13734. Epub 2021 Jan 19.
Antimicrobial photodynamic inactivation (aPDI) serves as a new approach to control the growth of foodborne bacteria. It remains elusive if the photodynamic efficacy of hypocrellin B (HB) can be potentiated by joint action with curcumin. In this study, we measured the survival rate of Staphylococcus aureus strains under the varying photodynamic conditions. According to our data, a maximum of 5-6 log decrease of bacterial survival can be achieved under the tested conditions (500 nM, 9 J cm ). Regarding the bactericidal mechanisms, HB-based aPDI disrupted the membrane integrity of staphylococcal cells, probably owing to the stimulated reactive oxygen species (ROS). In addition, aPDI disrupted the enzymatic activities of bacterial antioxidant proteins and caused the leakage of multiple intracellular substances. The HB-mediated photodynamic efficacy was potentiated by the addition of curcumin with a sublethal dose. This dual-photon synergy arose from unique aPDI conditions (100 nM each and 9 J cm ). The synergistic action might be accounted for by the increased type I/type II ratio of ROS, as evidenced by the effect of different quenchers. Finally, the joint use of photosensitizers reduced the microbial contamination of the tested apple while maintaining its quality. In summary, photodynamic inactivation based on dual photons showed synergistic activity in controlling the growth of Staphylococcal aureus, which provided a novel approach to maintain food safety.
抗菌光动力灭活（aPDI）是一种控制食源细菌生长的新方法。竹红菌素B（HB）与姜黄素联合作用是否能增强其光动力效果仍不清楚。在本研究中，我们测量了不同光动力条件下金黄色葡萄球菌菌株的存活率。根据我们的数据，在测试条件下（500 nM，9 J/cm²），细菌存活率最多可降低5-6个对数级。关于杀菌机制，基于HB的aPDI破坏了葡萄球菌细胞的膜完整性，这可能是由于活性氧（ROS）的刺激。此外，aPDI破坏了细菌抗氧化蛋白的酶活性，并导致多种细胞内物质泄漏。加入亚致死剂量的姜黄素可增强HB介导的光动力效果。这种双光子协同作用源于独特的aPDI条件（各100 nM，9 J/cm²）。不同淬灭剂的作用证明，协同作用可能是由于ROS的I型/II型比例增加所致。最后，联合使用光敏剂减少了测试苹果的微生物污染，同时保持了其品质。总之，基于双光子的光动力灭活在控制金黄色葡萄球菌生长方面显示出协同活性，这为维持食品安全提供了一种新方法。
