Distinct distribution revealing multiple bacterial sources for 1-O-monoalkyl glycerol ethers in terrestrial and lake environments
Distinct distribution revealing multiple bacterial sources for 1-O-monoalkyl glycerol ethers in terrestrial and lake environments
复制标题
独特的分布揭示了陆地和湖泊环境中 1-O-单烷基甘油醚的多种细菌来源
DOI：
10.1007/s11430-014-5016-z
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
Xie S.
中科院分区：
文献类型：
--
作者：
Yang H.;Zheng F.;Xiao W.;Xie S.
1-O-单烷基甘油醚（MAGEs）最初被认为是海洋环境中介导甲烷厌氧氧化的硫酸盐还原菌（SRB）的生物标志物。然而，关于它们在陆地和其他水生环境（包括土壤，淡水湖泊和洞穴沉积物）中的分布信息有限，这可能会模糊我们对其生物来源的理解。在这里，我们发现，MAGE是普遍存在的，但在这些环境中的分布模式有明显的差异。表层土壤中以iC 15：0-法师为主，其次为nC 16：0-法师，而湖泊沉积物中则相反，导致土壤中的iC 15：0/nC 16：0比值明显高于湖泊沉积物。洞穴沉积物的特征是分支MAGE的比例明显高于前两种环境。fC 15：0/aC 15：0比值的对数与土壤pH值呈显著负相关，可能反映了微生物细胞膜对环境质子浓度变化的适应。培养细菌中的法师谱不能完全解释分析的所有样品中的法师分布。因此，土壤、湖泊沉积物和洞穴沉积物中的MAGE可能有除硫酸盐还原菌和培养的产生MAGE的细菌之外的其他生物来源。不同环境中法师模式的差异可能归因于微生物群落的变化。
The 1-O-monoalkyl glycerol ethers (MAGEs) were initially viewed as the biomarkers for sulfate-reducing bacteria (SRB) mediating anaerobic oxidation of methane in the marine environments. However, limited information is known about their distribution in terrestrial and other aquatic settings including soils, fresh water lakes, and cave sediments, which may obscure our understanding of their biological sources. Here we found that MAGEs were ubiquitous but differed obviously in distributional pattern among those environments. The surface soils are dominated generally byiC15:0-MAGE, followed bynC16:0-MAGE whereas the lake sediments show the opposite, resulting in significantly higheriC15:0/nC16:0ratios in soils than in lake sediments. The cave deposits are characterized by considerably higher proportions of branched MAGEs than the former two environments. The logarithm ofiC15:0/aC15:0ratio shows a significant negative correlation with soil pH, likely reflecting an adaptation of microbial cell membrane to change in the ambient proton concentration. The MAGE profiles in cultured bacteria cannot fully explain the MAGE distribution in all the samples analyzed. Therefore, MAGEs in soil, lake sediments, and cave deposits likely have additional biological source(s) other than SRB and cultured MAGE-producing bacteria. The difference in MAGE pattern among environments is likely to be attributed to change in microbial communities.