Zhang Jiacheng, Liang Weixing, Wang Jia, Longshaw Matt, Dong Xiaohui, Yang Qihui, Liu Hongyu, Deng Junming, Tan Beiping, Chi Shuyan
Aquatic Animal Nutrition and Feed Laboratory, College of Fisheries, Guangdong Ocean University, Zhanjiang 524088, China.
Aquatic Animals Precision Nutrition and High-Efficiency Feed Engineering Research Centre of Guangdong Province, Zhanjiang 524088, China.
Anim Nutr. 2025 Jul 12;22:321-336. doi: 10.1016/j.aninu.2025.03.020. eCollection 2025 Sep.
The hybrid grouper () is an important aquaculture marine species in China. The current study was designed to test the effects of methanotroph () bacteria meal (MBM) on hybrid grouper growth and intestinal health outcomes. Five iso-nitrogenous and iso-lipidic diets were formulated, comprising a control diet (MBM0) with 400 g/kg fish meal (FM) as the main protein source, and four experimental diets, in which FM was replaced at 5% (MBM2), 10% (MBM4), 20% (MBM8) and 30% (MBM12) with 20, 40, 80 and 120 g/kg of MBM, respectively. The 450 healthy juvenile hybrid grouper (initial weight 28.84 ± 0.05 g) were randomly allocated into five groups, with three replicates in each group and 30 fish in each replicate. They were fed for eight weeks prior to being sampled for transcriptome and microbiome research. The final body weight (FBW, < 0.001) and weight gain rate (WGR, < 0.001) were obviously enhanced in MBM2 and MBM8 groups compared to MBM0 group, and the specific growth rate (SGR) in the MBM2 and MBM8 groups were significantly enhanced compared to MBM0 group ( < 0.001). The condition factor (CF) in MBM4 and MBM8 groups were considerably reduced than that in MBM0 group ( = 0.008). The hepatosomatic index (HSI) in MBM8 and MBM12 groups were obviously enhanced than that in the other groups ( < 0.001). In the intestinal microflora analysis, the number of operational taxonomic units (OTUs) exhibited a significant linear increase with increasing MBM replacement ratio ( = 0.015). Concurrently, the richness of bacterial families and genera showed significant linear enrichment ( = 0.023 and = 0.028, respectively). There was a decrease in the relative abundance of the potentially pathogenic genera and in the MBM-fed groups compared with the control group. The study has effectively shown that MBM may significantly enhance the health and growth of hybrid groupers by partially replacing FM in diets at the required amount of 3.70%, as determined by WGR regression analysis.
杂交石斑鱼（）是中国重要的海水养殖鱼类。本研究旨在测试甲烷氧化菌（）菌粉（MBM）对杂交石斑鱼生长和肠道健康的影响。配制了五种等氮等脂的饲料，包括一种以400 g/kg鱼粉（FM）作为主要蛋白质来源的对照饲料（MBM0），以及四种实验饲料，其中分别用20、40、80和120 g/kg的MBM替代了5%（MBM2）、10%（MBM4）、20%（MBM8）和30%（MBM12）的FM。将450尾健康的杂交石斑鱼幼鱼（初始体重28.84±0.05 g）随机分为五组，每组三个重复，每个重复30尾鱼。在进行转录组和微生物组研究取样前，它们被投喂八周。与MBM0组相比，MBM2组和MBM8组的终末体重（FBW，<0.001）和增重率（WGR，<0.001）明显提高，且MBM2组和MBM8组的特定生长率（SGR）与MBM0组相比显著提高（<0.001）。MBM4组和MBM8组的肥满度（CF）比MBM0组显著降低（=0.008）。MBM8组和MBM12组的肝体指数（HSI）比其他组明显提高（<0.001）。在肠道微生物群落分析中，可操作分类单元（OTU）的数量随MBM替代比例的增加呈显著线性增加（=0.015）。同时，细菌科和属的丰富度显示出显著的线性富集（分别为=0.023和=0.028）。与对照组相比，MBM喂养组中潜在致病属和的相对丰度有所下降。通过WGR回归分析确定，研究有效表明，MBM以3.7%的所需量部分替代饲料中的FM，可显著促进杂交石斑鱼的健康和生长。
