Microbial and geochemical mechanisms controlling dissolution processes of particulate organic matter in the oceans

控制海洋中颗粒有机物溶解过程的微生物和地球化学机制

• 批准号: 17201004
• 负责人: NAGATA Toshi
• 金额: $ 21.96万
• 依托单位: Kyoto University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 2005
• 资助国家: 日本
• 起止时间: 2005 至 2007
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-17201004/
• 关键词: Ocean; Particulate organic matter; Dissolved organic matter; Microbial loop; Material cycling; Bacterial community structure; Extracellular enzyme; Organic matter decomposition

Microbes play the major role in the regulation of material cycling in the oceans, but the mechanisms by which material fluxes mediated by bacteria are controlled have yet to be clarified fully. Especially our knowledge is limited regarding large scale patterns and controls of organic matter - bacteria interactions in oceanic water columns. In order to better understand dynamic features of the oceanic biogeochemical cycles at a large scale, this study examined patters in distributions of microbes and organic matter transformations and decomposition in the surface and deep water columns of the South and North Pacific. Our data revealed that bacterial production is largely coupled with the flux of sinking particulate organic carbon in the mesopelagic zone (100 - 1,000 m), supporting the hypothesis that particulate organic carbon -> dissolved organic carbon -> free-living prokaryote pathway is important in the regulation of the biological pump. However the coupling between the sinking fluxes of particulate organic carbon and prokaryotic activity was weak in the bathypelagic layer (>1,000 m), suggesting that the lateral transport or resuspension of organic matter from the sediment is important in that layer. We also investigated the dynamics of bacterial communities and microbial activities during the algal blooms. On the basis of the results obtained by mesocosm experiments, we concluded that filamentous bacteria affiliated with the Cytophaga-Flavobacter cluster play an important role in particulate organic matter decomposition during the bloom. Finally, we constructed a new mathematical model to examine dynamic behavior of bacterial communities during the decomposition of particulate and dissolved organic matter in the oceans. The above studies collectively revealed novel features in the organic matter- microbe interactions in the oceans.

微生物在调节海洋物质循环方面发挥着主要作用，但细菌介导的物质通量控制机制尚未完全阐明。特别是我们的知识是有限的大规模模式和控制的有机物-细菌在海洋水柱的相互作用。为了更好地了解大尺度海洋生物地球化学循环的动力学特征，本文研究了南太平洋和北太平洋表层和深层水柱中微生物的分布和有机质的转化与分解规律。我们的数据显示，细菌的产生在很大程度上与中层（100 - 1 000米）下沉颗粒有机碳的通量相结合，支持颗粒有机碳->溶解有机碳->自由生活的原核生物途径在生物泵的调节中很重要的假设。然而，在深海层（> 1 000米），颗粒有机碳下沉通量与原核生物活动之间的耦合很弱，这表明沉积物中有机物的横向迁移或再悬浮在该层很重要。我们还调查了藻类水华期间细菌群落和微生物活动的动态。根据围隔实验结果，我们得出结论，隶属于Cytophaga-Flavorescent簇的丝状菌在水华期间颗粒有机物分解中起着重要作用。最后，我们建立了一个新的数学模型，以研究细菌群落在海洋颗粒物和溶解有机物分解过程中的动态行为。上述研究共同揭示了海洋中有机物-微生物相互作用的新特征。

项目成果

Distribution patterns of viruses and their subclusters in the upper water columns of the Pacific and Southern Oceans

太平洋和南大洋上层水体中病毒及其亚群的分布模式

• 发表时间: 2007
• 作者: Yang;Y.;Yokokawa;T.;Motegi;C.;Nagata;T
• 通讯作者: T

Coexistence and succession in microbial metacommunity: potential linking between spatial heterogeneity in diversity and rapid shifts in community in response to environmental changes.

微生物元群落的共存和演替：多样性的空间异质性与群落响应环境变化的快速变化之间的潜在联系。

• 发表时间: 2007
• 作者: Miki T.;Yokokawa T.;Nagata T.;Yamamura N.
• 通讯作者: Yamamura N.

Large scale distribution patterns in bacterial abundance and production : from the Southern Ocean to the subarctic Pacific

细菌丰度和产量的大规模分布模式：从南大洋到亚北极太平洋

• 发表时间: 2007
• 作者: Yokokoawa;T.;Yang;Y.;Nagata;T.;Motegi;C
• 通讯作者: C

中部太平洋における細菌数と生産速度の水平鉛直分布:南緯67.5度-北緯53.6度間の南北断面観測結果

太平洋中部细菌数量和生产率的水平/垂直分布：南纬67.5°至北纬53.6°南北剖面的观测结果

• 发表时间: 2006
• 作者: 横川太一;楊燕輝;茂手木千晶;永田俊
• 通讯作者: 永田俊

細菌-ウィルス系の支配要因としてのリンの役割 -地中海沿岸水を用いた検証-

磷作为细菌病毒系统控制因素的作用 - 使用地中海水进行验证 -

• 发表时间: 2006
• 作者: 茂手木千晶;MG. Weinbauer;L. Legendre;F. Rassoulzadegan;永田俊
• 通讯作者: 永田俊