波罗的海桡足类肠道微生物组的微毛细管采样表明个体间存在高度可变性,并有产生甲烷的潜力。
Microcapillary sampling of Baltic Sea copepod gut microbiomes indicates high variability among individuals and the potential for methane production.
机构信息
Leibniz Institute for Baltic Sea Research, Rostock, Germany.
Department of Organismal Biology, Uppsala University, Uppsala, Sweden.
出版信息
FEMS Microbiol Ecol. 2019 Apr 1;95(4). doi: 10.1093/femsec/fiz024.
The paradox of methane oversaturation in oxygenated surface water has been described in many pelagic systems and still raises the question of the source. Temora sp. and Acartia sp. commonly dominate the surface and subsurface waters of the central Baltic Sea. It is hypothesised that their gut microbiome at least partly contributes to the methane anomaly in this ecosystem. However, the potential pathway for this methane production remains unclear. Using a microcapillary technique, we successfully overcame the challenge of sampling the gut microbiome of copepods <1 mm. 16S rRNA gene amplicon sequencing revealed differences among the dominant bacterial communities associated with Temora sp. (Actinobacteria, Betaproteobacteria and Flavobacteriia) and Acartia sp. (Actinobacteria, Alphaproteobacteria and Betaproteobacteria) and the surrounding water (Proteobacteria, Cyanobacteria and Verrucomicrobia), but also intraspecific variability. In both copepods, gut-specific prokaryotic taxa and indicative species for methane production pathways (methanogenesis, dimethylsulfoniopropionate or methylphosphonate) were present. The relative abundance of archaea and methanogens was investigated using droplet digital polymerase chain reaction and showed a high variability among copepod individuals, underlining intra- and interspecific differences in copepod-associated prokaryotic communities. Overall, this work highlights that the guts of Temora sp. and Acartia sp. have the potential for methane production but are probably no hotspot.
富氧表层水中甲烷过饱和的悖论在许多海洋系统中都有描述,但仍未解决甲烷的来源问题。中波罗的海的表层和次表层水中通常以 Temora sp. 和 Acartia sp. 为主。据推测,它们的肠道微生物组至少部分导致了该生态系统中的甲烷异常。然而,这种甲烷产生的潜在途径仍不清楚。使用微毛细管技术,我们成功地克服了从 <1 毫米的桡足类动物中取样肠道微生物组的挑战。16S rRNA 基因扩增子测序结果表明,与 Temora sp.(放线菌、β变形菌和黄杆菌)和 Acartia sp.(放线菌、α变形菌和β变形菌)相关的优势细菌群落与周围水(变形菌、蓝细菌和疣微菌)之间存在差异,但也存在种内变异。在这两种桡足类动物中,肠道特异性原核生物类群和指示甲烷产生途径(甲烷生成、二甲基巯基丙酸或甲基膦酸酯)的指示物种均存在。使用液滴数字聚合酶链反应(droplet digital polymerase chain reaction)研究了古菌和产甲烷菌的相对丰度,结果表明桡足类动物个体之间的丰度变化很大,强调了桡足类动物相关原核生物群落的种内和种间差异。总的来说,这项工作强调了 Temora sp. 和 Acartia sp. 的肠道具有产生甲烷的潜力,但可能不是热点。