Laboratório de Bioquímica e Microbiologia Aplicada, Departamento de Ciência de Alimentos, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
Laboratório de Bioquímica e Microbiologia Aplicada, Departamento de Ciência de Alimentos, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
Food Res Int. 2021 Feb;140:110074. doi: 10.1016/j.foodres.2020.110074. Epub 2020 Dec 29.
The antimicrobial peptide produced by Bacillus velesensis P34 has a broad activity against Gram-positive bacteria, showing potential as natural food preservative. In this work, nanocapsules (NCs) containing the peptide P34 were produced using the polymers poly-ε-caprolactone (PCL) or Eudragit RS-100 (EUD), and their antimicrobial activities were assessed evaluating L. monocytogenes growth in synthetic media, milk and isolated milk proteins. As results, cationic and anionic nanocapsules were obtained, with zeta potential ranging from +15 to +28 mV for EUD and around -19 mV for PCL, and average diameter in the range of 104-130 nm and 224-245 nm, respectively. In the antimicrobial tests, only the P34-EUD NCs presented activity against L. monocytogenes in BHI broth, possibly due to the EUD high swelling and permeability properties, as compared with PCL. In whole and skimmed milk, the P34-EUD NCs caused no inhibition of L. monocytogenes growth, due to a possible interaction of casein proteins with the NCs surface resulting in protein corona formation, which interfered with the antimicrobial peptide release. Therefore, the application of polymeric NCs as antimicrobial delivery systems in foods could be limited by the polymer type, and the adhesion of specific matrix proteins that could form protein corona, reducing the bioactive compound release.
由 velesensis P34 芽孢杆菌产生的抗菌肽对革兰氏阳性菌具有广泛的活性，显示出作为天然食品防腐剂的潜力。在这项工作中，使用聚合物聚己内酯 (PCL) 或 Eudragit RS-100 (EUD) 生产了含有肽 P34 的纳米胶囊 (NC)，并评估了它们在合成培养基、牛奶和分离的牛奶蛋白中对单核细胞增生李斯特菌生长的抗菌活性。结果得到了阳离子和阴离子纳米胶囊，EUD 的 ζ 电位范围为+15 至+28 mV，PCL 的 ζ 电位约为-19 mV，平均直径分别为 104-130 nm 和 224-245 nm。在抗菌测试中，只有 P34-EUD NC 对 BHI 肉汤中的单核细胞增生李斯特菌表现出活性，这可能是由于 EUD 具有高溶胀性和渗透性，与 PCL 相比。在全脂和脱脂牛奶中，P34-EUD NC 对单核细胞增生李斯特菌的生长没有抑制作用，这可能是由于酪蛋白与 NCs 表面的相互作用导致形成蛋白冠，从而干扰了抗菌肽的释放。因此，聚合物 NC 作为抗菌递送系统在食品中的应用可能受到聚合物类型和可能形成蛋白冠的特定基质蛋白的粘附的限制，从而减少了生物活性化合物的释放。
