鲈-蟹混养模式下不同饵料对大口黑鲈生长和肠道菌群的影响

Effects of Different Diets on Growth and Intestinal Bacterial Community of Micropterus salmoides in Bass-crab Polyculture Pattern

为研究鲈-蟹混养模式下冰鲜鱼(HB)、配合饲料(HS)和混合投喂(HH)等3种饵料投喂对大口黑鲈(Micropterus salmoides)生长和肠道菌群影响,采用16S rRNA基因高通量测序技术,分析了不同饵料对大口黑鲈生长性能、肠道菌群结构和多样性的影响。结果表明,生长性能指标方面,配合饲料组试验鱼的末均重、体长和特定生长率均显著低于冰鲜鱼组和混合投喂组的(P<0.05),混合投喂组最后养成规格最大,生长速度也最快,但与冰鲜鱼组差异不显著(P>0.05)。多样性分析结果显示,配合饲料的投喂降低了大口黑鲈肠道菌群的丰富度和多样性。在肠道菌群结构方面,冰鲜鱼组的优势菌属主要为克雷伯氏菌属(Klebsiella)、分枝杆菌属(Mycobacterium)、罗姆布茨菌属(Romboutsia)及发光杆菌属(Photobacterium),配合饲料组优势菌属为罗姆布茨菌(Romboutsia)、克雷伯氏菌属(Klebsiella)、分枝杆菌属(Mycobacterium)及醋杆菌属(Cetobacterium),而混合投喂组优势菌属则是克雷伯氏菌属(Klebsiella)、分枝杆菌属(Mycobacterium)、支原体属(Mycoplasma)及厌氧氨氧化菌属(Candidatus_Brocadia)。冰鲜鱼组大口黑鲈肠道菌群在“能量生产与转化”和“辅酶运输和代谢”功能类群的相对丰度最高,而配合饲料投喂组肠道菌群在“核苷酸的转运与代谢”“脂质转运与代谢”“翻译、核糖体结构和生物发生”和“转录”功能类群的相对丰度占优,但三组间功能类群的丰度没有显著性差异(P>0.05)。研究结果揭示,配合饲料投喂改变了大口黑鲈肠道菌群结构,降低了微生物群落多样性。本研究为大口黑鲈的健康养殖和配合饲料开发提供了理论依据。

To investigate the effects on growth and intestinal microbiota of largemouth bass(Micropterus salmoides)in bass-crab polyculture pattern,the frozen fish,formulated feed and frozen fish plus formulated feed(mixed)were used with 16 S rRNA high throughput sequencing.Results showed that the formulated feed group had the lowest average final body weight,body length,and specific growth rate,which were significantly lower than that of the frozen fish group and the mixed group(P<0.05),but there were no significant differences between the frozen fish group and the mixed group(P>0.05).The community richness and diversity of the intestinal bacterial community were the lowest in the formulated feed group,and the highest in the frozen fish group.In the genera level,Klebsiella,Mycobacterium,Romboutsia and Photobacterium were the dominant gene-ra in the frozen fish group,while Romboutsia,Klebsiella,Mycobacterium and Cetobacterium were the dominant genera in the formulated feed group,and Klebsiella,My-cobacterium,Mycoplasma and Candidatus_Brocadia were the dominant genera in the mixed group respectively.Functional prediction showed that the abundance of functional genes involved in"energy production and conversion"and"coenzyme transport and metabolism"were dominant in the frozen fish group.Meanwhile,the abundance of functional genes involved in"amino acid transport and metabolism""li-pid transport and metabolism""translation,ribosomal structure and biogenesis"and"transcription"were dominant in the formulated feed group.However,there was no significant difference in the abundance of functional clusters among the three groups(P>0.05).Taken together,the formulated feed sharped the structure of intestinal microflora to a certain extent and decreased the diversity of bacterial communities obviously.The present study provided scientific data for healthy cultivation and formulated feed innovation of Micropterus salmoides.