重金属积累和致病菌对水产养殖造成不良影响。硒(Se)纳米颗粒的活性表面可以减轻这些影响。本研究使用抗硒枯草芽孢杆菌AS12制备生物硒纳米颗粒(Bio-SeNP)。测试了双刃Bio-SeNPs减少尼罗罗非鱼(Oreochromisniloticus)中重金属和细菌负荷的有害影响的能力以及它们各自对鱼类生长的影响,行为,和健康。Bio-SeNPs呈球形,平均尺寸为77nm,类黄酮和酚类含量高(0.7和1.9gg-1槲皮素和没食子酸当量,分别),导致相当的抗氧化和抗菌活性。本研究中的Bio-SeNP(3-5μgml-1)解决了水产养殖业面临的两个严重问题,首先,病原菌的数量,尤其是嗜水气单胞菌,在鱼类器官中减少了28-45%。其次,响应Bio-SeNP(3-5μgml-1),两个水平(1和2μgml-1)的重金属(Cd和Hg)减少了50-87%和57-73%。因此,肝功能参数降低,内部免疫力增强。Bio-SeNPs(3-5μgml-1)的应用改善了鱼肠健康,增长,和行为,导致鱼的体重增加36-52%和40%的特定增长率,与对照组相比。此外,进食和唤醒时间增加了20-22%和28-53%,分别,与相同处理的对照组相比,侵略时间减少了78%。总之,Bio-SeNPs可以减轻重金属的积累,并以浓度依赖的方式减少细菌负荷,在鱼类媒介或鱼类器官中。
Heavy metal accumulation and pathogenic bacteria cause adverse effects on aquaculture. The active surface of selenium (Se) nanoparticles can mitigate these effects. The present study used Se-resistant Bacillus subtilis AS12 to fabricate biological Se nanoparticles (Bio-SeNPs). The double-edged Bio-SeNPs were tested for their ability to reduce the harmful effects of heavy metals and bacterial load in Nile tilapia (Oreochromis niloticus) and their respective influences on fish growth, behavior, and health. The Bio-SeNPs have a spherical shape with an average size of 77 nm and high flavonoids and phenolic content (0.7 and 1.9 g g-1 quercetin and gallic acid equivalents, respectively), resulting in considerable antioxidant and antibacterial activity. The Bio-SeNPs (3-5 μg ml-1) in the current study resolved two serious issues facing the aquaculture industry, firstly, the population of pathogenic bacteria, especially Aeromonas hydrophilia, which was reduced by 28-45% in fish organs. Secondly, heavy metals (Cd and Hg) at two levels (1 and 2 μg ml-1) were reduced by 50-87% and 57-73% in response to Bio-SeNPs (3-5 μg ml-1). Thus, liver function parameters were reduced, and inner immunity was enhanced. The application of Bio-SeNPs (3-5 μg ml-1) improved fish gut health, growth, and behavior, resulting in fish higher weight gain by 36-52% and a 40% specific growth rate, compared to controls. Furthermore, feeding and arousal times increased by 20-22% and 28-53%, respectively, while aggression time decreased by 78% compared to the control by the same treatment. In conclusion, Bio-SeNPs can mitigate the accumulation of heavy metals and reduce the bacterial load in a concentration-dependent manner, either in the fish media or fish organs.