Ahmed Firas A, Arif Mohammad, Alvarez Anne M
Department of Plant and Environmental Protection Sciences, University of Hawaii at Manoa, HonoluluHI, United States.
Front Microbiol. 2017 Sep 12;8:1728. doi: 10.3389/fmicb.2017.01728. eCollection 2017.
Soft rot caused by is one of most common bacterial diseases occurring in fruits and vegetables worldwide, yet consumer-acceptable options for post-harvest disease management are still insufficient. We evaluated the effect of potassium tetraborate tetrahydrate (BKO.4HO) (PTB) on the growth of using strain BA17 as a representative of high virulence. Complete inhibition of bacterial growth was achieved by treatment with PTB at 100 mM both at pH 9.2 and after adjustment to pH 7.0. Bactericidal activity was quantified and validated by counting fluorescently labeled live and dead bacterial cells using flow cytometry, and reconfirmed using qPCR with high-affinity photoreactive DNA binding dye propidium monoazide (PMA). The results of flow cytometry, qPCR, and culturing confirmed that bacterial cells were killed following exposure to PTB at 100 mM. Bacterial cell membranes were damaged following a 5-min treatment and extrusion of cytoplasmic material from bacterial cells was observed using electronic transmission microscopy. Soft rot incidence on inoculated tomato fruit was significantly reduced by dipping infected fruits in PTB at 100 mM for 5 min and no lesions developed following a 10-min treatment. PTB does not pose a hazard to human health and is an effective alternative to other bactericides and antibiotics for controlling soft rot disease of tomato caused by
由[未提及具体病原菌]引起的软腐病是全球水果和蔬菜中最常见的细菌性病害之一，但采后病害管理中消费者可接受的选择仍然不足。我们以高毒力菌株BA17为代表，评估了四水合四硼酸钾（BKO·4H₂O）（PTB）对[未提及具体病原菌]生长的影响。在pH 9.2以及调至pH 7.0后，用100 mM的PTB处理均能完全抑制细菌生长。通过流式细胞术对荧光标记的活细菌和死细菌细胞进行计数来量化和验证杀菌活性，并使用高亲和力光反应性DNA结合染料单叠氮化丙锭（PMA）通过qPCR再次确认。流式细胞术、qPCR和培养结果证实，暴露于100 mM的PTB后细菌细胞被杀死。经5分钟处理后细菌细胞膜受损，使用电子透射显微镜观察到细菌细胞内的细胞质物质被挤出。将感染的番茄果实浸入100 mM的PTB中5分钟，接种番茄果实上的软腐病发病率显著降低，经10分钟处理后未出现病斑。PTB对人类健康不构成危害，是控制由[未提及具体病原菌]引起的番茄软腐病的其他杀菌剂和抗生素的有效替代品。
