Kumar Amit, Ghate Vinayak, Kim Min-Jeong, Zhou Weibiao, Khoo Gek Hoon, Yuk Hyun-Gyun
Food Science and Technology Programme, Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543, Singapore.
Food Science and Technology Programme, Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543, Singapore; National University of Singapore (Suzhou) Research Institute, No. 377 Linquan Street, Suzhou Industrial Park, Suzhou, Jiangsu, 215123, China.
Food Microbiol. 2017 May;63:12-21. doi: 10.1016/j.fm.2016.10.032. Epub 2016 Oct 24.
The objective of this study was to investigate the effect of 460 nm light-emitting diode (LED) on the inactivation of foodborne bacteria. Additionally, the change in the endogenous metabolic profile of LED illuminated cells was analyzed to understand the bacterial response to the LED illumination. Six different species of bacteria (Bacillus cereus, Listeria monocytogenes, Staphylococcus aureus, Escherichia coli O157:H7, Pseudomonas aeruginosa and Salmonella Typhimurium) were illuminated with 460 nm LED to a maximum dose of 4080 J/cm at 4, 10 and 25 °C. Inactivation curves were modeled using Hom model. Metabolic profiling of the non-illuminated and illuminated cells was performed using a Liquid chromatography-mass spectrometry system. Results indicate that the 460 nm LED significantly (p < 0.05) reduced the populations of all six bacterial species. For example, the population of S. aureus reached below detection limit within 7 h. B. cereus was most resistant to photo-inactivation and exhibited about 3-log reduction in 9 h. Metabolic profiling of the illuminated cells indicated that several metabolites e.g. 11-deoxycortisol, actinonin, coformycin, tyramine, chitobiose etc. were regulated during LED illumination. These results elucidate the effectiveness of 460 nm LED against foodborne bacteria and hence, its suitability as a novel antimicrobial control method to ensure food safety.
本研究的目的是调查460纳米发光二极管（LED）对食源性病原体灭活的影响。此外，分析LED照射细胞的内源性代谢谱变化，以了解细菌对LED照射的反应。六种不同的细菌（蜡样芽孢杆菌、单核细胞增生李斯特菌、金黄色葡萄球菌、大肠杆菌O157:H7、铜绿假单胞菌和鼠伤寒沙门氏菌）在4、10和25℃下用460纳米LED照射，最大剂量为4080 J/cm²。使用Hom模型对灭活曲线进行建模。使用液相色谱-质谱系统对未照射和照射细胞进行代谢谱分析。结果表明，460纳米LED显著（p<0.05）降低了所有六种细菌的数量。例如，金黄色葡萄球菌的数量在7小时内降至检测限以下。蜡样芽孢杆菌对光灭活最具抗性，在9小时内表现出约3个对数级的减少。照射细胞的代谢谱分析表明，在LED照射期间，几种代谢物如11-脱氧皮质醇、放线诺宁、助间型霉素、酪胺、壳二糖等受到调控。这些结果阐明了460纳米LED对食源性病原体的有效性，因此，它作为一种确保食品安全的新型抗菌控制方法的适用性。
