食品科学 ›› 2019, Vol. 40 ›› Issue (21): 7-13.doi: 10.7506/spkx1002-6630-20180923-243

• 基础研究 • 上一篇    下一篇

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

付咪,俞佳丽,郭亮,李延华,陈杰,孟岳成   

  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

摘要: 为了提高乳酸链球菌素(Nisin)的利用率,实现其长效、缓释型抑菌性能,采用薄膜-超声法制备Nisin脂质体,以大豆卵磷脂为壁材,利用傅里叶变换红外光谱分析Nisin脂质体的内部结构及不同pH值条件对Nisin脂质体稳定性及其包埋率和缓释效果的影响,比较不同pH值条件下热处理对Nisin脂质体抑菌效果的影响。结果表明:Nisin被结合在卵磷脂内部,两者通过相互作用形成的氢键结合在一起。随着体系pH值的降低,Nisin脂质体的粒径逐渐增大,颗粒规整度变差,同时包埋率降低、缓释性变差,稳定性逐渐降低。当pH值为7.0时,Nisin脂质体的包埋率(82.26%)达到最大。此外,pH 6.0时体系缓释能力最强,6 d后总释放率达到96.49%。最小抑菌浓度和最小杀菌浓度分析结果表明,Nisin脂质体的抑菌效果受pH值的影响较小,且与Nisin相比抑菌效果较弱。然而,Nisin脂质体在121 ℃、15 min灭菌处理后仍具有良好的抑菌效果,表明该体系具有热稳定性。动态杀菌曲线结果表明Nisin脂质体具有一定的持续抑菌性能。

关键词: 乳酸链球菌素, 脂质体, 抑菌效果, 粒径, 包埋率

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.

Key words: nisin, liposomes, antibacterial effect, particle size, encapsulation efficiency

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