Microbial Communities and Organic Matter Composition in Surface and Subsurface Sediments of the Helgoland Mud Area, North Sea.
Microbial Communities and Organic Matter Composition in Surface and Subsurface Sediments of the Helgoland Mud Area, North Sea.
复制标题
北海Helgoland Mud区域的表面和地下沉积物中的微生物群落和有机物组成。
DOI：
10.3389/fmicb.2015.01290
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发表时间：
2015
影响因子：
5.2
通讯作者：
Friedrich MW
中科院分区：
文献类型：
--
作者：
Oni OE;Schmidt F;Miyatake T;Kasten S;Witt M;Hinrichs KU;Friedrich MW
微生物在沉积有机碳循环中的作用是至关重要的。为了更好地了解潜在生物可利用部分有机质的分子组成与微生物种群之间的关系，利用基于16S rRNA基因分析的方法，对北海Helgoland泥区表层（顶部30 cm）和地下/深层（30 - 530 cm）沉积物中的细菌和古细菌群落进行了表征。傅里叶变换离子回旋共振质谱（FT-ICR MS）用于表征潜在生物可利用的有机物组分（热水可提取有机物，WE-OM）。藻类聚合物相关的微生物种群，如伽马变形菌门、拟杆菌门和Verrucomicrobia在表层沉积物中占主导地位，而绿藻菌门（Dehalococcoidales和候选目GIF9）和杂藻古菌群（Miscellaneous Crenarchaeota Groups， MCG）的成员在地下沉积物中占主导地位，这两种微生物都与更顽固的芳香族化合物和碎屑蛋白的降解有关。地下沉积物中占优势的微生物种群（Chloroflexi、MCG成员和Thermoplasmata）与总有机碳（TOC）含量有很强的相关性。WE-OM随沉积物深度的变化揭示了由富氧[高氧碳比（O/C），低氢碳比（H/C）]芳香族化合物和高度不饱和化合物向低氧碳比和高氢碳比化合物转变的过程。观察到的分子变化在只含有CHO原子的有机化合物中最为明显。因此，我们的数据突出了沉积有机化合物的类别，这些化合物可能在甲烷海洋地下环境中作为微生物能源。
The role of microorganisms in the cycling of sedimentary organic carbon is a crucial one. To better understand relationships between molecular composition of a potentially bioavailable fraction of organic matter and microbial populations, bacterial and archaeal communities were characterized using pyrosequencing-based 16S rRNA gene analysis in surface (top 30 cm) and subsurface/deeper sediments (30–530 cm) of the Helgoland mud area, North Sea. Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR MS) was used to characterize a potentially bioavailable organic matter fraction (hot-water extractable organic matter, WE-OM). Algal polymer-associated microbial populations such as members of the Gammaproteobacteria, Bacteroidetes, and Verrucomicrobia were dominant in surface sediments while members of the Chloroflexi (Dehalococcoidales and candidate order GIF9) and Miscellaneous Crenarchaeota Groups (MCG), both of which are linked to degradation of more recalcitrant, aromatic compounds and detrital proteins, were dominant in subsurface sediments. Microbial populations dominant in subsurface sediments (Chloroflexi, members of MCG, and Thermoplasmata) showed strong correlations to total organic carbon (TOC) content. Changes of WE-OM with sediment depth reveal molecular transformations from oxygen-rich [high oxygen to carbon (O/C), low hydrogen to carbon (H/C) ratios] aromatic compounds and highly unsaturated compounds toward compounds with lower O/C and higher H/C ratios. The observed molecular changes were most pronounced in organic compounds containing only CHO atoms. Our data thus, highlights classes of sedimentary organic compounds that may serve as microbial energy sources in methanic marine subsurface environments.