Information on environmental conditions shaping archaeal communities thriving at the seafloor of the central Pacific Ocean is limited. The present study was conducted to investigate the diversity, composition, and function of both entire and potentially active archaeal communities within Pacific deep-sea sediments. For this purpose, sediment samples were taken along the 180° meridian of the central Pacific Ocean. Community composition and diversity were assessed by Illumina tag sequencing targeting archaeal 16S rRNA genes and transcripts. Archaeal communities were dominated by Candidatus Nitrosopumilus (Thaumarchaeota) and other members of the Nitrosopumilaceae (Thaumarchaeota), but higher relative abundances of the Marine Group II (Euryarchaeota) were observed in the active compared to the entire archaeal community. The composition of the entire and the active archaeal communities was strongly linked to primary production (chlorophyll content), explaining more than 40% of the variance. Furthermore, we found a strong correlation of the entire archaeal community composition to latitude and silicic acid content, while the active community was significantly correlated with primary production and ferric oxide content. We predicted functional profiles from 16S rRNA data to assess archaeal community functions. Latitude was significantly correlated with functional profiles of the entire community, whereas those of the active community were significantly correlated with nitrate and chlorophyll content. The results of the present study provide first insights into benthic archaeal communities in the Pacific Ocean and environmental conditions shaping their diversity, distribution, and function. Additionally, they might serve as a template for further studies investigating archaea colonizing deep-sea sediments.

中文翻译：

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水体中的初级生产是中太平洋深海沉积物中古菌生物地理分布和功能的主要结构元素。

关于影响中太平洋海底古菌群落繁荣的环境条件的信息有限。本研究旨在调查太平洋深海沉积物中整个古菌群落和潜在活跃古菌群落的多样性、组成和功能。为此，沿太平洋中部 180° 子午线采集沉积物样本。通过针对古菌 16S rRNA 基因和转录本的 Illumina 标签测序评估群落组成和多样性。古菌群落以亚硝化古菌( Thaumarchaeota ) 和亚硝化古菌科( Thaumarchaeota )的其他成员为主，但与整个古菌群落相比，在活跃区域观察到海洋 II 类 ( Euryarchaeota ) 的相对丰度较高。整个古菌群落和活跃古菌群落的组成与初级生产（叶绿素含量）密切相关，解释了超过 40% 的差异。此外，我们发现整个古菌群落组成与纬度和硅酸含量有很强的相关性，而活跃群落与初级生产力和氧化铁含量显着相关。我们根据 16S rRNA 数据预测功能概况，以评估古菌群落功能。纬度与整个群落的功能特征显着相关，而活跃群落的功能特征与硝酸盐和叶绿素含量显着相关。本研究的结果首次深入了解太平洋底栖古菌群落以及影响其多样性、分布和功能的环境条件。此外，它们还可以作为进一步研究古细菌在深海沉积物中殖民的模板。