Host-associated microbial communities are fundamental to host physiology, yet it is unclear how these communities will respond to environmental disturbances. Here, we disentangle the environment-linked and host-linked effects of ocean acidification on oyster-associated microbial communities. We exposed adult oysters (Crassostrea virginica) to CO₂-induced ocean acidification (400 vs. 2800 ppm) for 80 d. We measured the oyster extrapallial fluid pH and sampled the gills for microbial analysis at six time points. We found that different subsets of microbes were linked to acidification (n = 34 amplicon sequence variants [ASVs]) and to host response (n = 20 ASVs) with little overlap (n = 8 ASVs), suggesting that some members of the oyster microbiome were more responsive to environmental conditions while others were more tightly linked to host condition. Our results provide insight into which members of the oyster microbiome may contribute to the health and resistance of their host, and which members are the most vulnerable to changing environmental conditions.

中文翻译：

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海洋酸化改变了牡蛎相关微生物群落的多样性和结构

宿主相关的微生物群落是宿主生理学的基础，但尚不清楚这些群落将如何应对环境干扰。在这里，我们解开海洋酸化对牡蛎相关微生物群落的环境相关和宿主相关影响。我们将成年牡蛎（Crassostrea virginica）暴露于 CO ₂引起的海洋酸化（400 与 2800 ppm）中 80 天。我们测量了牡蛎外皮液的 pH 值，并在六个时间点对鳃取样进行微生物分析。我们发现不同的微生物亚群与酸化（n  = 34 个扩增子序列变异 [ASV]）和宿主反应（n  = 20 个 ASV）有关，几乎没有重叠（n = 8 个 ASV），表明牡蛎微生物组的一些成员对环境条件更敏感，而另一些成员与宿主条件的联系更紧密。我们的研究结果让我们深入了解牡蛎微生物群的哪些成员可能有助于宿主的健康和抵抗力，哪些成员最容易受到不断变化的环境条件的影响。