A denitrifying community associated with a major, marine nitrogen fixer
A denitrifying community associated with a major, marine nitrogen fixer
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DOI：
10.1111/1462-2920.14007
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发表时间：
2017-12-01
影响因子：
5.1
通讯作者：
Wyman, Michael
中科院分区：
文献类型：
--
作者：
Coates, Christopher J.;Wyman, Michael
重氮蓝细菌Trichodesmium是海洋氮循环的一个组成部分，为贫营养的热带/亚热带海洋表面沃茨提供大量的新氮。束毛藻（Trichodesmium）形成宏观、纺锤形（簇状）、球形（簇状）和筏状菌落，为许多其他生物提供假底栖栖息地，包括海洋无脊椎动物、微真核生物和许多其他微生物。使用一系列基于分子的方法，针对编码反硝化途径中的末端步骤的基因，一氧化二氮还原酶（nosZ），询问与菌落相关的微生物的多样性和活性。束毛藻属从地理上孤立的海洋省份（大西洋，红海和印度洋）的采样显示，港口高度相似，分类相关的群落的细菌，其成员隶属于玫瑰枝内的杜鹃花科（Alphaproteobacteria）。这些生物积极表达nosZ从大西洋中部和红海的样品中，这意味着束毛藻菌落是潜在的一氧化二氮消耗的网站，也许在反硝化途径的早期步骤也。有人建议，耦合硝化作用的新固定的N是最有可能的来源，氮氧化物支持一氧化二氮循环内束毛藻殖民地。
The diazotrophic cyanobacterium, Trichodesmium, is an integral component of the marine nitrogen cycle and contributes significant amounts of new nitrogen to oligotrophic, tropical/subtropical ocean surface waters. Trichodesmium forms macroscopic, fusiform (tufts), spherical (puffs) and raft-like colonies that provide a pseudobenthic habitat for a host of other organisms including marine invertebrates, microeukaryotes and numerous other microbes. The diversity and activity of denitrifying bacteria found in association with the colonies was interrogated using a series of molecular-based methodologies targeting the gene encoding the terminal step in the denitrification pathway, nitrous oxide reductase (nosZ). Trichodesmium spp. sampled from geographically isolated ocean provinces (the Atlantic Ocean, the Red Sea and the Indian Ocean) were shown to harbor highly similar, taxonomically related communities of denitrifiers whose members are affiliated with the Roseobacter clade within the Rhodobacteraceae (Alphaproteobacteria). These organisms were actively expressing nosZ in samples taken from the mid-Atlantic Ocean and Red Sea implying that Trichodesmium colonies are potential sites of nitrous oxide consumption and perhaps earlier steps in the denitrification pathway also. It is proposed that coupled nitrification of newly fixed N is the most likely source of nitrogen oxides supporting nitrous oxide cycling within Trichodesmium colonies.