• 基础研究 •

### 乳酸链球菌素脂质体在不同pH值条件下的稳定性及其抑菌效果

1. （浙江工商大学食品与生物工程学院，浙江 杭州 310018）
• 出版日期:2019-11-15 发布日期:2019-12-02
• 基金资助:
国家自然科学基金面上项目（31871830）；浙江省重点研发计划项目（2018C02SA890220）； “食品科学与工程浙江省重中之重一级学科”资助项目（2017SIAR217）

### Stability and Antibacterial Activity of Nisin-Loaded Liposomes under Different pH Conditions

FU Mi, YU Jiali, GUO Liang, LI Yanhua, CHEN Jie, MENG Yuecheng

1. (School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou 310018, China)
• Online:2019-11-15 Published:2019-12-02

Abstract: In order to improve the utilization efficiency of nisin and to achieve its long-lasting and sustained-release antibacterial properties, nisin-loaded liposomes were prepared with soy lecithin as the wall material by thin film evaporation-sonication method. The internal structure of nisin-loaded liposomes was analyzed by infrared spectroscopy. The effects of pH on the stability, encapsulation efficiency and sustained release rate were studied as well as the effect of heat treatment on bacteriostatic properties of nisin-loaded liposomes under different pH conditions. It was found that nisin was bound to lecithin inside by electrostatic interaction. The particle size of liposomes kept increasing and the regularity deteriorated and with decreasing pH. At the same time, the encapsulation efficiency and the release rate decreased, and the liposomes became unstable. A maximum encapsulation efficiency of 82.26% was obtained at pH 7.0. In addition, the system had the strongest sustained release ability at pH 6.0, and the total release rate was up to 96.49% after 6 days. Based on the minimum inhibitory concentration and the minimum bactericidal concentration, the antibacterial effect of nisin-loaded liposomes was little affected by pH and slightly inferior to that of free nisin monomers. However, nisin-loaded liposomes still had good antibacterial effect after high temperature treatment at 121 ℃ for 15 min, indicating that the system had good thermal stability. The time-killing kinetic curve showed that the nisin-loaded liposomes showed a good bactericidal effect in a slow-release way.