Plant-based protein ingredients have become an attractive substitute for traditional animal sources in the aquaculture feed industry. However, inclusion in carnivorous fish diets is limited due to reduced digestibility, presence of anti-nutritional factors, and increased risk of digestive tract inflammation. To gain further insight on the adaptation of the fish digestive tract environment to plant-based protein sources, intestinal bacterial communities from Hybrid Striped Bass, Morone chrysops x M. saxatilis, fed diets supplemented with different protein sources were compared. Data were generated by Illumina MiSeq 2X300 sequencing of PCR generated amplicons targeting the V1–V3 regions of the 16S rRNA gene. A comparative analysis using the non-parametric Kruskal-Wallis test identified 17 highly represented species-level Operational Taxonomic Units (OTUs) that differed in abundance across dietary treatments (P < 0.05). Notably, OTU SD_McMs-0001 was at its highest abundance in samples from individuals fed poultry-fishmeal (PFM; 47.61% ± 0.92%) and plant protein-based (PP; 43.13% ± 1.76%) diets, while it was found in much lower abundance in the non-supplemented control diet samples (B; 4.29% ± 0.92%). It was predicted to be a novel species of the family Peptostreptococcaceae based on its limited 16S rRNA gene sequence identity to its closest valid relative (Peptostreptococcus russellii, 91%). In contrast, three Proteobacteria-affiliated OTUs (SD_McMs-0002, SD_McMs-0003, and SD_McMs-0004) were most highly represented in B diet samples, with averages of 30.28%, 27.22%, and 13.54%, respectively. They were in much lower abundance in the PFM and PP samples, with averages ranging between 0.18% and 4.82%, respectively. Based on 16S rRNA sequence comparisons, they were predicted to be strains of Plesiomonas shigelloides (99%), Ralstonia pickettii (99%) and Sphingomonas elodea (99%), respectively. These results indicate that protein supplementation affects gut bacterial community composition of Hybrid Striped Bass, but that the type of protein used has minimal or no detectable impact.

中文翻译：

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183 蛋白质补充对混合条纹鲈鱼、Morone Chrysops X M. Saxatilis 肠道细菌群落组成的影响

基于植物的蛋白质成分已成为水产饲料行业传统动物来源的有吸引力的替代品。然而，由于消化率降低、抗营养因子的存在以及消化道炎症风险增加，肉食性鱼类饮食中的加入受到限制。为了进一步了解鱼类消化道环境对植物性蛋白质来源的适应情况，我们比较了来自 Hybrid Striped Bass、Morone chrysops x M. saxatilis 的肠道细菌群落，以及补充了不同蛋白质来源的饲料。数据是通过 Illumina MiSeq 2X300 测序生成的 PCR 生成的扩增子，该扩增子靶向 16S rRNA 基因的 V1-V3 区域。使用非参数 Kruskal-Wallis 检验的比较分析确定了 17 个高度代表性的物种级操作分类单位 (OTU)，它们在不同饮食处理中的丰度不同（P < 0.05）。值得注意的是，OTU SD_McMs-0001 在饲喂家禽鱼粉 (PFM; 47.61% ± 0.92%) 和植物蛋白 (PP; 43.13% ± 1.76%) 饮食的个体样本中的丰度最高，而在许多未补充的对照饮食样品中的丰度较低（B；4.29% ± 0.92%）。根据其与其最接近的有效亲属（罗氏消化链球菌，91%）的有限 16S rRNA 基因序列同一性，预测它是消化链球菌科的一个新物种。相比之下，三种变形菌相关的 OTU（SD_McMs-0002、SD_McMs-0003 和 SD_McMs-0004）在 B 饮食样本中的代表性最高，平均分别为 30.28%、27.22% 和 13.54%。它们在 PFM 和 PP 样品中的丰度要低得多，平均值分别在 0.18% 和 4.82% 之间。根据 16S rRNA 序列比较，预测它们分别是 Plesiomonas shigelloides (99%)、Ralstonia pickettii (99%) 和 Sphingomonas elodea (99%) 的菌株。这些结果表明，蛋白质补充会影响 Hybrid Striped Bass 的肠道细菌群落组成，但所用蛋白质类型的影响很小或没有可检测到的影响。分别为 Ralstonia pickettii (99%) 和 Sphingomonas elodea (99%)。这些结果表明，蛋白质补充会影响 Hybrid Striped Bass 的肠道细菌群落组成，但所用蛋白质类型的影响很小或没有可检测到的影响。分别为 Ralstonia pickettii (99%) 和 Sphingomonas elodea (99%)。这些结果表明，蛋白质补充会影响 Hybrid Striped Bass 的肠道细菌群落组成，但所用蛋白质类型的影响很小或没有可检测到的影响。