植物乳杆菌LP21绿色合成纳米硒及对溶藻弧菌的抑菌活性

采用益生菌植物乳杆菌LP21合成纳米硒，为抑制水产养殖中溶藻弧菌感染提供一种新的方法。通过植物乳杆菌LP21绿色合成纳米硒，对所得纳米硒进行透射电镜形貌及能谱分析，粒径仪测定粒径，红外光谱分析纳米硒表面生物分子的分布，并研究纳米硒对溶藻弧菌的抑菌活性。结果表明，植物乳杆菌LP21还原的纳米硒呈球形，分散性良好；纯化的纳米硒平均尺寸为184.6 nm，其表面包裹蛋白、多糖等生物分子，呈无定形态；纳米硒对溶藻弧菌、大肠杆菌的抑菌活性较强，对溶藻弧菌的最小抑菌浓度为286 μg/mL，在亚抑制剂量下对溶藻弧菌的生长、运动性、生物膜有显著抑制，并引起菌体细胞形态发生变化，此抑菌研究为纳米硒在水产养殖业感染菌防治中的应用提供依据。

Biosynthesis of Nano-Selenium by Lactobacillus plantarum LP21 and Its Antibacterial Activity against Vibrio alginolyticus

Nano-selenium synthesized by the probiotic bacterium Lactobacillus plantarum LP21 was analyzed by transmission electron microscopy (TEM) and energy spectroscopy, and its particle size was measured by a particle size analyzer. Additionally, biomolecule distribution on the surface of nano-selenium were analyzed by Fourier transform infrared (FTIR) spectroscopy, and the antibacterial activity of nano-selenium against Vibrio alginolyticus was tested. The results showed that the nano-selenium was spherical in shape and well dispersed; the average particle size of the purified nano-selenium was 184.6 nm, and its surface was covered with proteins, polysaccharides and other biological molecules, showing an amorphous form. The antibacterial activity of nano-selenium against V. alginolyticus and Escherichia coli was strong, and the minimum inhibitory concentration (MIC) against V. alginolyticus was 286 μg/mL. The growth, motility and biofilm of V. alginolyticus were significantly inhibited by the nano-selenium at sub-inhibitory doses, and the cell morphology was changed as well. The results of this study provide a basis for its application to control pathogenic infection in aquaculture.