Department of Food and Animal Biotechnology, Department of Agricultural Biotechnology, Center for Food and Bioconvergence, and Research Institute for Agricultural and Life Sciences, Seoul National University, Seoul 08826, Republic of Korea; Institutes of Green Bio Science & Technology, Seoul National University, Pyeongchang-gun, Gangwon-do, 25354, Republic of Korea.
Department of Food and Animal Biotechnology, Department of Agricultural Biotechnology, Center for Food and Bioconvergence, and Research Institute for Agricultural and Life Sciences, Seoul National University, Seoul 08826, Republic of Korea; Institutes of Green Bio Science & Technology, Seoul National University, Pyeongchang-gun, Gangwon-do, 25354, Republic of Korea.
Food Res Int. 2017 Jul;97:280-287. doi: 10.1016/j.foodres.2017.04.009. Epub 2017 Apr 25.
Recently, UVC-LED technology has been validated as an alternative to irradiation with conventional mercury UV lamps. In this study, we sought to determine primary factors affecting reduction trends shown in several microorganisms. Four major foodborne pathogens (Escherichia coli O157:H7, Salmonella spp. Listeria monocytogenes, Staphylococcus aureus) and spoilage yeasts (Saccharomyces pastorianus, Pichia membranaefaciens), important to the brewing industry, were inoculated onto selective and non-selective media in order to investigate reduction tendencies at 4 different peak wavelengths (266 to 279nm). As irradiation dose increased, inactivation levels for every microorganism were enhanced, but there were different UV-sensitivities in Gram positive bacteria (GP), Gram negative bacteria (GN), and yeasts (Y). Loss of membrane integrity measured by propidium iodide (PI) increased as peak wavelength increased for every microorganism studied. Similar results were observed in membrane potential measured by DiBAC(3). However, there were contrasting results which showed that greater DNA damage occurred at a lower peak wavelength as measured by Hoechst 33,258. The level of DNA damage was strongly related to trends of microbial inactivation. This study showed that even though membrane damage was present in every microorganism studied, DNA damage was the primary factor for inactivating microorganisms through UVC-LED treatment.
最近，UVC-LED 技术已被验证可作为替代传统汞紫外线灯照射的方法。在这项研究中，我们试图确定影响几种微生物显示的减少趋势的主要因素。四种主要食源性致病菌（大肠杆菌 O157：H7、沙门氏菌、李斯特菌单核细胞增生症、金黄色葡萄球菌）和酿造工业中重要的腐败酵母（酿酒酵母、膜醭毕赤酵母）被接种到选择性和非选择性培养基上，以研究在 4 个不同的峰值波长（266nm 至 279nm）下的减少趋势。随着辐照剂量的增加，每种微生物的失活水平都得到了提高，但革兰氏阳性菌（GP）、革兰氏阴性菌（GN）和酵母（Y）的紫外线敏感性不同。用碘化丙啶（PI）测量的膜完整性损失随着研究中每种微生物的峰值波长的增加而增加。用 DiBAC(3) 测量的膜电位也观察到了类似的结果。然而，有相反的结果表明，较低的峰值波长下会发生更大的 DNA 损伤，如 Hoechst 33,258 所测量的那样。DNA 损伤的程度与微生物失活动态密切相关。本研究表明，尽管研究中的每种微生物都存在膜损伤，但 DNA 损伤是通过 UVC-LED 处理使微生物失活的主要因素。
