Sala Maria Montserrat, Ruiz-González Clara, Borrull Encarna, Azúa Iñigo, Baña Zuriñe, Ayo Begoña, Álvarez-Salgado X Antón, Gasol Josep M, Duarte Carlos M
Department of Marine Biology and Oceanography, Institut de Ciències del Mar, Consejo Superior de Investigaciones Científicas, Barcelona, Spain.
Department of Immunology, Microbiology, and Parasitology, Faculty of Science and Technology, University of the Basque Country UPV/EHU, Leioa, Spain.
Front Microbiol. 2020 Jun 4;11:918. doi: 10.3389/fmicb.2020.00918. eCollection 2020.
Prokaryotes play a fundamental role in decomposing organic matter in the ocean, but little is known about how microbial metabolic capabilities vary at the global ocean scale and what are the drivers causing this variation. We aimed at obtaining the first global exploration of the functional capabilities of prokaryotes in the ocean, with emphasis on the under-sampled meso- and bathypelagic layers. We explored the potential utilization of 95 carbon sources with Biolog GN2 plates in 441 prokaryotic communities sampled from surface to bathypelagic waters (down to 4,000 m) at 111 stations distributed across the tropical and subtropical Atlantic, Indian, and Pacific oceans. The resulting metabolic profiles were compared with biological and physico-chemical properties such as fluorescent dissolved organic matter (DOM) or temperature. The relative use of the individual substrates was remarkably consistent across oceanic regions and layers, and only the Equatorial Pacific Ocean showed a different metabolic structure. When grouping substrates by categories, we observed some vertical variations, such as an increased relative utilization of polymers in bathypelagic layers or a higher relative use of P-compounds or amino acids in the surface ocean. The increased relative use of polymers with depth, together with the increases in humic DOM, suggest that deep ocean communities have the capability to process complex DOM. Overall, the main identified driver of the metabolic structure of ocean prokaryotic communities was temperature. Our results represent the first global depiction of the potential use of a variety of carbon sources by prokaryotic communities across the tropical and the subtropical ocean and show that acetic acid clearly emerges as one of the most widely potentially used carbon sources in the ocean.
原核生物在海洋中有机物分解过程中发挥着重要作用，但对于微生物代谢能力在全球海洋尺度上如何变化以及导致这种变化的驱动因素却知之甚少。我们旨在首次对海洋中原核生物的功能能力进行全球探索，重点关注采样不足的中层和深层海水层。我们利用Biolog GN2平板，对从热带和亚热带大西洋、印度洋及太平洋的111个站点采集的441个原核生物群落进行了研究，这些群落取自表层至深层海水（深度达4000米），以探索95种碳源的潜在利用情况。将所得的代谢谱与诸如荧光溶解有机物（DOM）或温度等生物学和物理化学性质进行了比较。各个底物的相对利用情况在不同海洋区域和水层中显著一致，只有赤道太平洋呈现出不同的代谢结构。当按类别对底物进行分组时，我们观察到了一些垂直变化，例如深层海水层中聚合物的相对利用率增加，或者表层海洋中磷化合物或氨基酸的相对利用率更高。随着深度增加聚合物相对利用率的提高，以及腐殖质DOM的增加，表明深海群落有能力处理复杂的DOM。总体而言，确定的海洋原核生物群落代谢结构的主要驱动因素是温度。我们的研究结果首次全面描述了热带和亚热带海洋中原核生物群落对多种碳源的潜在利用情况，并表明乙酸显然是海洋中最广泛潜在利用的碳源之一。
