Department of Biology, McMaster University, Hamilton, Ontario, Canada.
Department of Biology, McMaster University, Hamilton, Ontario, Canada; School of Earth, Environment and Society, McMaster University, Hamilton, Ontario, Canada.
Comp Biochem Physiol Part D Genomics Proteomics. 2021 Sep;39:100835. doi: 10.1016/j.cbd.2021.100835. Epub 2021 Apr 20.
An increasing number of laboratory studies are showing that environmental stressors and diet affect the fish gut microbiome. However, the application of these results to wild populations is uncertain as little is known about how the gut microbiome shifts when fish are transitioned from the field to the laboratory. To assess this, intestinal contents (i.e. digesta) of wild-caught rainbow darter (Etheostoma caeruleum) were sampled in the field and in the lab after 14- and 42-days acclimation. In addition, from days 15-42 some fish were exposed to waterborne triclosan, an antimicrobial found in aquatic ecosystems, or to dilutions of municipal wastewater effluents, to determine how these stressors affect the bacterial communities of gut contents. 16S rRNA gene amplicon sequencing was used to determine microbial community composition, alpha, and beta diversity present in the fish gut contents. In total, there was 8,074,658 reads and 11,853 amplicon sequence variants (ASVs) identified. The gut contents of wild fish were dominant in both Proteobacteria (35%) and Firmicutes (27%), while lab fish were dominant in Firmicutes (37-47%) and had lower alpha diversity. Wild fish had greater ASVs per sample (423-1304) compared to lab fish (19-685). Similarly, the beta-diversity of these bacterial communities differed between field and lab control fish; control fish were distinct from the 10% wastewater effluent and 100 ng/L TCS treatment groups. Results indicate that the gut microbiome of wild fish changes with the transition to laboratory environments; hence, prolonged acclimation to new settings may be required to achieve a stable gut content microbiome in wild-caught fish. Research is required to understand the length of time required to reach a stable fish gut microbiome.
越来越多的实验室研究表明，环境压力和饮食会影响鱼类肠道微生物组。然而，由于人们对鱼类从野外过渡到实验室时肠道微生物组如何变化知之甚少，因此这些结果在野外种群中的应用尚不确定。为了评估这一点，从野外和实验室中采集了野生彩虹鮈（Etheostoma caeruleum）的肠道内容物（即消化物），并在适应 14 天和 42 天后进行了采样。此外，在第 15 天至第 42 天期间，一些鱼暴露于水传播的三氯生（一种存在于水生生态系统中的抗菌剂）或城市废水的稀释物中，以确定这些压力源如何影响肠道内容物中的细菌群落。16S rRNA 基因扩增子测序用于确定鱼类肠道内容物中存在的微生物群落组成、alpha 和 beta 多样性。总共鉴定出 8074658 条reads 和 11853 个扩增子序列变体（ASV）。野生鱼类的肠道内容物主要由变形菌门（35%）和厚壁菌门（27%）组成，而实验室鱼类则主要由厚壁菌门（37-47%）组成，alpha 多样性较低。野生鱼类的每个样本中的 ASV 数量（423-1304）多于实验室鱼类（19-685）。同样，这些细菌群落的 beta 多样性在野外和实验室对照鱼类之间也存在差异；对照鱼类与 10%废水和 100ng/L TCS 处理组明显不同。结果表明，野生鱼类的肠道微生物组随着向实验室环境的过渡而发生变化；因此，可能需要对新环境进行长时间的适应，才能使野生鱼类的肠道内容物微生物组达到稳定状态。需要研究了解达到稳定鱼类肠道微生物组所需的时间长度。
