Phylogenetic analysis of intestinal microflora indicates a novel Mycoplasma phylotype in farmed and wild salmon
Phylogenetic analysis of intestinal microflora indicates a novel Mycoplasma phylotype in farmed and wild salmon
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DOI：
10.1007/s00248-002-1011-6
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发表时间：
2002-08-01
影响因子：
3.6
通讯作者：
Apajalahti, JHA
中科院分区：
文献类型：
--
作者：
Holben, WE;Williams, P;Apajalahti, JHA
到目前为止，所有关于鲑鱼胃肠道微生物群落的研究都采用了基于养殖的方法，通常是在池塘或池塘饲养的淡水动物上进行的。我们介绍了存在于远端的细菌种群的系统发育调查。来自欧洲三个不同海洋地点的三文鱼的肠道。这是通过从幽门盲肠远端胃肠道内容物分离的微生物群落DNA中扩增、克隆和测序部分16S rDNA基因来完成的。利用这种方法，比较了苏格兰野生三文鱼和苏格兰和挪威圈养三文鱼的肠道微生物群落。检测到的优势菌群为朱尼不动杆菌和一种新的支原体系统型。这种支原体系统型显然与野生鲑鱼远端肠道中的微生物总数的96%相似。两组围栏养殖的鲑鱼在肠道微生物群落组成和多样性方面有很大的差异，除了地理上的分离外，它们是用不同的饲料饲养的。这项研究中发现的微生物谱与早期基于养殖的几种鱼的研究结果有很大不同，可能是因为采用了独立于养殖的技术。此外，对消化道中短链脂肪酸的分析表明，恒温动物常见的从近端到远端的氧化还原梯度在鲑鱼中是不存在的，而且细菌发酵水平远低于恒温动物的报道。
All studies of the microbial community of the gastrointestinal tract of salmon to date have employed culture-based approaches, typically on pond- or tank-raised, freshwater animals. We present a phylogenetic survey of the bacterial populations present in the distal. intestine of salmon from three different marine locations in Europe. This was accomplished through PCR amplification, cloning, and sequencing of partial 16S rDNA genes from microbial community DNA isolated from the contents of the GI tract distal to the pyloric ceca. Using this approach, the intestinal microbial communities of wild salmon from Scotland and pen-raised salmon from Scotland and Norway were compared. The predominating bacterial populations detected were Acinetobacter junii and a novel Mycoplasma phylotype. This Mycoplasma phylotype apparently comprised similar to96% of the total microbes in the distal intestine of wild salmon. Substantial differences in intestinal microbial community composition and diversity were observed between the two groups of pen-raised salmon, which, in addition to geographical separation, were raised on different feeds. The microbial profiles found in this study were substantially different from those indicated in earlier culture-based studies for several species of fish, presumably because of the culture-independent techniques employed. Further, analysis of short-chain fatty acids in the digestive tract indicated that the decreasing redox gradient from proximal to distal reaches common to homeothermic animals was absent in salmon, and that the bacterial fermentation levels were much lower than are reported in homeothermic animals.