Environmental factors shaping the archaeal community structure and ether lipid distribution in a subtropic river and estuary, China.
Environmental factors shaping the archaeal community structure and ether lipid distribution in a subtropic river and estuary, China.
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环境因素影响中国亚热带河流和河口的古菌群落结构和醚脂分布。
DOI：
10.1007/s00253-017-8595-8
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发表时间：
2018
期刊：
影响因子：
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通讯作者：
Zhang Chuanlun L
中科院分区：
文献类型：
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作者：
Guo Wenting;Xie Wei;Li Xueying;Wang Peng;Hu Anyi;Zhang Chuanlun L
浮游植物在水生和陆生生境中分布广泛，数量丰富，在全球生态地球化学循环中起着重要作用。类异戊二烯甘油二烷基甘油四醚（iGDGT）等古生菌脂类是自然界古生菌群落结构变化和古生菌地球化学过程的重要生物标志物。然而，古生菌种群和GDGT分布在自然环境中的联系是很差的检查，这阻碍了GDGT为基础的气候或环境代理的应用和解释。我们解决了这个问题，通过调查古细菌的脂质组成和群落结构的变化，在环境变量的背景下，沿着中国南方的亚热带九龙江流域（JRW）和九龙江口（JRE）。结果表明，无论是古细菌细胞和极性GDGT（P-GDGT）在JRW和JRE大多是本地的，而不是外源输入周围的土壤。在16个谱系中，只有5个（甲烷细菌目、深海古生菌、海洋底栖动物类群A（MBGA）、海洋底栖动物类群B（MBGB）和海洋底栖动物类群D（MBGD））对P-GDGT组成有显著影响，表明这些古生菌对P-GDGT组成的变化有重要贡献。盐度和总磷（TP）对古菌遗传组成和P-GDGT组成的分布有显着影响;而砂和粉砂含量仅对P-GDGT有显着影响。海洋沉积物中广泛存在的MBGD古菌与JRW和JRE中的P-TEX 86信号呈正相关，表明未培养的MBGD古菌可能也对海洋沉积物中TEX 86信号的变化有贡献。该研究揭示了P-GDGT的来源及其在河控大陆边缘分布的控制因素，为GDGT替代指标在古气候研究中的应用提供了参考。
Archaea are widespread and abundant in aquatic and terrestrial habitats and play fundamental roles in global biogeochemical cycles. Archaeal lipids, such as isoprenoid glycerol diakyl glycerol tetraethers (iGDGTs), are important biomarkers tracing changes in archaeal community structure and biogeochemical processes in nature. However, the linkage between the archaeal populations and the GDGT distribution in the natural environment is poorly examined, which hindered the application and interpretation of GDGT-based climate or environmental proxies. We addressed this question by investigating changes in archaeal lipid composition and community structure in the context of environmental variables along the subtropical Jiulong River Watershed (JRW) and Jiulong River Estuary (JRE) in southern China. The results showed that both the archaeal cells and the polar GDGTs (P-GDGTs) in the JRW and JRE were mostly autochthonous rather than exogenous input from surrounding soils. We further found that only five (Methanobacteriales, Ca.Bathyarchaeota, Marine Benthic Groups A (MBGA), Marine Benthic Groups B (MBGB), and Marine Benthic Groups D (MBGD)) out of sixteen lineages showed significant impacts on the composition of P-GDGTs, suggesting the significant contribution of those archaea to the changes of P-GDGT compositions. Salinity and total phosphorus (TP) showed significant impact on the distribution of both genetic and P-GDGTs compositions of archaea; whereas, sand and silt contents only had significant impact on the P-GDGTs. MBGD archaea, which occur widely in marine sediments, showed positive correlations with P-TEX86in the JRW and JRE, suggesting that uncultivated MBGD might also contribute to the variations in TEX86signals in marine sediments. This study provided insight into the sources of P-GDGTs and the factors controlling their distributions in river-dominated continental margins, which has relevance to applications of GDGT-based proxies in paleoclimate studies.