豆粕对乌鳢肠道菌群组成及微生物氨基酸代谢酶活性的影响

为研究豆粕替代鱼粉对乌鳢生长、肠道菌群组成和微生物相关氨基酸代谢酶活性的影响,分别用豆粕替代0、25%、50%和75%的鱼粉配制4组等氮等能的饲料饲喂初始体质量为(8.65±0.25)g的幼鱼(分别命名为G1、G2、G3和G4组),养殖实验在室内纤维玻璃钢桶中进行,实验周期为21 d。结果显示,各组间幼鱼成活率无显著性差异;G4组乌鳢幼鱼的生长性能显著低于G1和G2组,而G3组幼鱼生长性能与其余3组差异不显著。厚壁菌门在G1和G2组乌鳢肠道中的比例显著高于G3组,且在G4组中的比例最低;变形菌门在G1和G2组中的比例显著低于G3和G4组;G4组中乳球菌属、杆菌属、假单胞菌属、链球菌属、芽孢杆菌属和不动杆菌属的比例显著低于其余3组。另外,G4组幼鱼肠道微生物谷丙转氨酶、腺苷脱氨酶活性显著高于其余3组,而G1组乳酸脱氢酶的活性最高。研究表明,豆粕替代鱼粉除了对乌鳢幼鱼的生长产生影响外,也显著影响了肠道微生物组成及微生物相关氨基酸代谢酶的活性,本研究结果对于从微生态角度进一步理解豆粕在乌鳢配合饲料中的应用提供了理论依据和参考。

Effects of dietary soybean meal on the intestinal microbiota and metabolic enzymes activities of microbial amino acids of Channa argus

This study aimed to investigate the effect of soybean meal on the growth, intestinal microbiota composition and metabolic enzymatic activities of microbial amino acid of Channa argus. Four isonitrogenous and isoenergetic diets were formulated with soybean meal by replacing 0, 25%, 50% and 75% fish meal (G1, G2, G3 and G4, respectively). The fish of (8.65±0.25) g was hand-fed daily to satiation twice in cylindrical fiberglass tanks for 21 days. Results showed that no significant difference in survival rate was found among four groups. The growth performance of C. argus in G4 was significantly lower than those in G1 and G2, while the difference was not statistically significant between G3 and other three groups. The proportion of Firmicutes in the intestine of fish in G1 and G2 was significantly higher than that in G3, and the lowest was found in G4. The proportion of Proteobacteria in G1 and G2 was significantly lower than those in G3 and G4. The proportion of Lactococcus, Bacillus, Pseudomonas, Streptococcus, Laseczka and Acinetobacter in G4 was significantly lower than those in the other three groups. Additionally, the activities of glutamic-pyruvic transaminase and adenosine deaminase were the the highest in G4, while the activity of lactic dehydrogenase was the the highest in G1. All results indicated that, except for the effect on the growth of C. argus, dietary soybean meal significantly induced the changes in the intestinal microbiota composition and the activity of the microbial amino acid metabolic enzymes, which may provide theoretical basis for further understanding the application of soybean meal in the formulated diets of C. argus.