Department of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, Republic of Korea.
Department of Food and Nutrition, Wonkwang University, Iksan, Jeonbuk, Republic of Korea.
J Appl Microbiol. 2022 Oct;133(4):2474-2483. doi: 10.1111/jam.15719. Epub 2022 Aug 3.
This study was done to determine the effects of temperature, pH and sodium chloride (NaCl) on antimicrobial activity of magnesium oxide (MgO) nanoparticles (NPs) against E. coli O157:H7.
Culture conditions were established by varying the pH (5.0, 7.2 and 9.0), NaCl concentration (0.5, 2.0, 3.5 and 5.0%, w/v), and incubation temperatures (4, 12, 22 and 37°C). At each condition, the antimicrobial activities of MgO-NPs (0, 1, 2 and 4 mg/ml) against E. coli O157:H7 were measured. Four-way analysis of variance indicated interactions among all factors had a significant effect (p ≤ 0.05) on the antimicrobial activity of MgO-NPs. The concentration of MgO-NPs necessary to cause a 5-log reduction of E. coli O157:H7 under the most inhibitory conditions (37°C, pH 9.0, and 5.0% NaCl) was 0.50 mg/ml of MgO-NPs.
The antimicrobial activity of the MgO-NPs increased significantly (p ≤ 0.05) with increased temperature, pH and NaCl concentration in TSB.
The influence of intrinsic and extrinsic factors on antimicrobial activity of MgO-NPs we found will contribute to the development of microbial decontamination strategies using MgO in the food industry.
本研究旨在确定温度、pH 值和氯化钠（NaCl）对氧化镁（MgO）纳米颗粒（NPs）对大肠杆菌 O157:H7 的抗菌活性的影响。
通过改变 pH 值（5.0、7.2 和 9.0）、NaCl 浓度（0.5、2.0、3.5 和 5.0%，w/v）和孵育温度（4、12、22 和 37°C）来确定培养条件。在每种条件下，测量了 MgO-NPs（0、1、2 和 4 mg/ml）对大肠杆菌 O157:H7 的抗菌活性。四因素方差分析表明，所有因素之间的相互作用对 MgO-NPs 的抗菌活性有显著影响（p≤0.05）。在最具抑制作用的条件下（37°C、pH 9.0 和 5.0%NaCl），导致大肠杆菌 O157:H7 减少 5 个对数的 MgO-NPs 的浓度为 0.50 mg/ml 的 MgO-NPs。
在 TSB 中，MgO-NPs 的抗菌活性随着温度、pH 值和 NaCl 浓度的增加而显著增加（p≤0.05）。
我们发现的内在和外在因素对 MgO-NPs 抗菌活性的影响将有助于在食品工业中开发使用 MgO 的微生物去污策略。
