Frischkorn Kyle R, Rouco Mónica, Van Mooy Benjamin A S, Dyhrman Sonya T
Department of Earth and Environmental Sciences and the Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, USA.
Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA, USA.
ISME J. 2017 Sep;11(9):2090-2101. doi: 10.1038/ismej.2017.74. Epub 2017 May 23.
Trichodesmium is a genus of marine diazotrophic colonial cyanobacteria that exerts a profound influence on global biogeochemistry, by injecting 'new' nitrogen into the low nutrient systems where it occurs. Colonies of Trichodesmium ubiquitously contain a diverse assemblage of epibiotic microorganisms, constituting a microbiome on the Trichodesmium host. Metagenome sequences from Trichodesmium colonies were analyzed along a resource gradient in the western North Atlantic to examine microbiome community structure, functional diversity and metabolic contributions to the holobiont. Here we demonstrate the presence of a core Trichodesmium microbiome that is modulated to suit different ocean regions, and contributes over 10 times the metabolic potential of Trichodesmium to the holobiont. Given the ubiquitous nature of epibionts on colonies, the substantial functional diversity within the microbiome is likely an integral facet of Trichodesmium physiological ecology across the oligotrophic oceans where this biogeochemically significant diazotroph thrives.
束毛藻是一类海洋固氮蓝藻，通过向其生存的低营养系统中注入“新”氮，对全球生物地球化学产生深远影响。束毛藻的群体普遍含有多种附生微生物，在束毛藻宿主上构成了一个微生物群落。沿着北大西洋西部的资源梯度，对束毛藻群体的宏基因组序列进行了分析，以研究微生物群落结构、功能多样性以及对共生体的代谢贡献。在这里，我们证明了存在一个核心束毛藻微生物群落，它会根据不同的海洋区域进行调节，并为共生体贡献了超过束毛藻代谢潜力10倍的代谢能力。鉴于群体上附生生物的普遍存在，微生物群落内丰富的功能多样性可能是束毛藻生理生态学不可或缺的一个方面，在贫营养海洋中，这种具有重要生物地球化学意义的固氮生物十分繁盛。
