Instituto de Productos Lácteos de Asturias (IPLA-CSIC), Paseo Río Linares s/n, 33300 Villaviciosa, Spain.
Nanovex Biotechnologies S.L., Parque Tecnológico de Asturias, CEEI, 33428 Llanera, Spain.
Viruses. 2018 Sep 13;10(9):495. doi: 10.3390/v10090495.
The antimicrobial properties of bacteriophages make them suitable food biopreservatives. However, such applications require the development of strategies that ensure stability of the phage particles during food processing. In this study, we assess the protective effect of encapsulation of the bacteriophage phiIPLA-RODI in three kinds of nanovesicles (niosomes, liposomes, and transfersomes). All these systems allowed the successful encapsulation of phage phiIPLA-RODI with an efficiency ranged between 62% and 98%, regardless of the concentration of components (like phospholipids and surfactants) used for vesicle formation. Only niosomes containing 30 mg/mL of surfactants exhibited a slightly lower percentage of encapsulation. Regarding particle size distribution, the values determined for niosomes, liposomes, and transfersomes were 0.82 ± 0.09 µm, 1.66 ± 0.21 µm, and 0.55 ± 0.06 µm, respectively. Importantly, bacteriophage infectivity was maintained during storage for 6 months at 4 °C for all three types of nanovesicles, with the exception of liposomes containing a low concentration of components. In addition, we observed that niosomes partially protected the phage particles from low pH. Thus, while free phiIPLA-RODI was not detectable after 60 min of incubation at pH 4.5, titer of phage encapsulated in niosomes decreased only 2 log units. Overall, our results show that encapsulation represents an appropriate procedure to improve stability and, consequently, antimicrobial efficacy of phages for application in the food processing industry.
噬菌体的抗菌特性使它们成为合适的食品生物防腐剂。然而，此类应用需要开发确保噬菌体颗粒在食品加工过程中稳定性的策略。在这项研究中，我们评估了将噬菌体 phiIPLA-RODI 封装在三种纳米囊泡（脂质体、转脂体和非离子型脂质体）中的保护效果。所有这些系统都成功地将噬菌体 phiIPLA-RODI 封装，封装效率在 62%至 98%之间，与用于囊泡形成的成分（如磷脂和表面活性剂）的浓度无关。只有含有 30mg/mL 表面活性剂的非离子型脂质体显示出稍低的封装百分比。关于粒径分布，确定的非离子型脂质体、脂质体和转脂体的值分别为 0.82±0.09μm、1.66±0.21μm 和 0.55±0.06μm。重要的是，在 4°C 下储存 6 个月期间，所有三种类型的纳米囊泡都保持了噬菌体的感染力，除了含有低浓度成分的脂质体外。此外，我们观察到非离子型脂质体部分保护了噬菌体颗粒免受低 pH 的影响。因此，虽然游离的 phiIPLA-RODI 在 pH 4.5 孵育 60 分钟后不可检测，但封装在非离子型脂质体中的噬菌体的效价仅下降了 2 个对数单位。总体而言，我们的结果表明，封装是提高噬菌体稳定性和抗菌功效的一种合适方法，从而可将其应用于食品加工行业。
