Department of Fisheries, Faculty of Marine Natural Resources, Khorramshahr University of Marine Science and Technology, Khorramshahr, Iran.
Agricultural Research, Educating and Extension Organization, Isfahan Agricultural and Natural Resources Research and Training Center, Isfahan, Iran.
Fish Physiol Biochem. 2021 Feb;47(1):153-162. doi: 10.1007/s10695-020-00903-8. Epub 2020 Nov 26.
A completely randomized experimental design carried out to investigate the effects of different levels of Pediococcus acidilactici (PA) including 0 (basal diet as a control diet), 1 × 10, 2 × 10, 4 × 10, and 8 × 10 colony-forming unit (CFU) per gram of the diet for 60 days on the mucosal immunity responses, growth, and reproductive performance, in zebrafish, Danio rerio (with mean weigh ± SE: 120 ± 10 mg). The obtained results revealed that the best growth and reproduction indices were related to the concentration of 4 × 10 CFU PA g diet (P < 0.05). The maximum activities of mucosal immune responses including total protein, alternative complement system, IgM, and lysozyme were observed in the fish fed with 4 × 10 CFU PA g diet (P < 0.05). Furthermore, the maximum alkaline phosphatase activity of skin mucus was recorded in the fish fed with 8 × 10 CFU PA g diet (P < 0.05). Fish fed with 4 × 10 CFU PA g diet had the highest villus length and width of the intestine (P < 0.05). Supplementing the diet with 4 × 10 CFU PA g diet more significantly enhanced Cyp19a gene expression in comparison with this in other groups. Hence, PA with a concentration of 4 × 10 CFU g diet can be considered as a proper level of probiotic for improving the health, growth, and reproductive performance of the D. rerio.
采用完全随机实验设计，研究了不同水平的植物乳杆菌（PA）对斑马鱼（Danio rerio）黏膜免疫应答、生长和繁殖性能的影响，实验设置了 0（基础日粮作为对照日粮）、1×10、2×10、4×10 和 8×10 个 CFU/g 日粮共 6 个处理组，实验周期为 60 天。实验结果表明，生长和繁殖性能最佳的相关浓度为 4×10 CFU/g 日粮（P＜0.05）。黏膜免疫应答总蛋白、替代补体系统、IgM 和溶菌酶的最大活性出现在 4×10 CFU/g 日粮组（P＜0.05）。此外，皮肤黏液碱性磷酸酶活性最高的是 8×10 CFU/g 日粮组（P＜0.05）。4×10 CFU/g 日粮组的鱼肠绒毛长度和宽度最大（P＜0.05）。与其他组相比，日粮中添加 4×10 CFU/g 植物乳杆菌显著提高了 Cyp19a 基因的表达。因此，4×10 CFU/g 日粮的植物乳杆菌可以被认为是一种适当的益生菌水平，可提高 D. rerio 的健康、生长和繁殖性能。
