半乳糖基月桂酸单甘酯对短小芽孢杆菌的抑制机理  

Antimicrobial Activity and Mode of Action of Monogalactosyl Monolaurate against Bacillus pumilus

作　　者：许苗苗 訾玉祥 陆兆新[1] 吕凤霞[1] 张充[1] 别小妹[1] 赵海珍[1] XU Miaomiao;ZI Yuxiang;LU Zhaoxin;LU Fengxia;ZHANG Chong;BIE Xiaomei;ZHAO Haizhen(College of Food Science and Technology,Nanjing Agricultural University,Nanjing 210095,China)

机构地区：[1]南京农业大学食品科学技术学院

出　　处：《食品科学》2020年第1期33-40,共8页Food Science

基　　金：国家自然科学基金面上项目（31771950）;国家自然科学基金青年科学基金项目（31301558）

摘　　要：短小芽孢杆菌(Bacillus pumilus)是一种食源性致病菌,且与食品腐败密切相关,易引起食品安全问题,造成巨大的经济损失。因此,开发一种天然有效的抗菌剂来控制短小芽孢杆菌至关重要。本实验研究了半乳糖基月桂酸单甘酯(monogalactosyl monolaurate,MGML)对短小芽孢杆菌的抑菌活性及作用机制。结果表明,MGML的最小抑菌浓度为313μg/mL;MGML对短小芽孢杆菌的抑菌活性呈浓度依赖性。Ca2+、K+及具有紫外吸收的物质泄漏表明短小芽孢杆菌细胞膜的通透性改变。扫描电子显微镜观察发现经MGML处理后,菌体表面皱缩凹陷、出现破裂和穿孔,表明细胞受到损伤。紫外吸收光谱和荧光猝灭效应表明MGML可引起DNA损伤并影响其合成。十二烷基硫酸钠-聚丙烯酰胺凝胶电泳结果显示MGML可影响蛋白质的合成。综上,MGML可作为一种有效的食品防腐剂抑制短小芽孢杆菌。Bacillus pumilus, a foodborne pathogen closely associated with food spoilage, can cause food safety issues and substantial financial losses. Thus, developing an effective natural antimicrobial agent is crucial for controlling B. pumilus. Herein, the antimicrobial activity and action mechanism of monogalactosyl monolaurate(MGML) against B. pumilus was investigated. Results showed that the minimum inhibitory concentration(MIC) of MGML was 313 μg/m L. The antimicrobial activity was concentration dependent. MGML caused leakage of intracellular Ca2+ and K+ and ultraviolet(UV)-absorbing materials, indicating altered membrane permeability of B. pumilus cells. According to scanning electron microscopic observation, the surface of bacterial cells became wrinkled and even ruptured with holes in it after treatment with MGML, indicating that the cells were damaged. Analysis of the ultraviolet absorption spectra and the fluorescence quenching spectra suggested that MGML could cause DNA damage and affect its synthesis. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE) results showed that MGML also could affect the synthesis of protein. These results suggested that MGML has the potential to be used as a food preservative against B. pumilus.

关 键 词：半乳糖基月桂酸单甘酯 抑菌活性 抑菌机制 短小芽孢杆菌 细胞膜损伤 

分 类 号：TS201.3[轻工技术与工程—食品科学]