کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5162963 1379763 2006 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Polar and neutral isopranyl glycerol ether lipids as biomarkers of archaea in near-surface sediments from the Nankai Trough
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آلی
پیش نمایش صفحه اول مقاله
Polar and neutral isopranyl glycerol ether lipids as biomarkers of archaea in near-surface sediments from the Nankai Trough
چکیده انگلیسی
The molecular and carbon isotopic compositions of polar isopranyl glycerol ether lipids, which are direct indicators of viable archaea, and neutral isopranyl glycerol ether lipids, which are derived from polar lipids via hydrolysis, in near-surface sediments from a methane seep in the Nankai Trough (off central Japan) were investigated. Procedures for extracting, separating and derivatizing polar and neutral ether lipids for detection using gas chromatography were first examined with one sediment sample and a cultivated methanogen. For all sediment samples, archaeol and hydroxyarchaeol were detected in both the polar and neutral ether lipid fractions. Acyclic and cyclic biphytanes were also detected in both types of lipid fractions after treatment with HI/LiAlH4 for ether cleavage and alkylation. The δ13C values of archaeol, sn-2-hydroxyarchaeol, and sn-3-hydroxyarchaeol in the sample from 0.82 m below the seafloor were lower than −100‰ relative to PDB, indicating that diverse living methanotrophic archaea are present in the seep sediments. Biphytanes released from polar ether lipids in the same sample were less depleted in δ13C (−71‰ to −36‰). The wide range of δ13C values suggests that the biphytanes were derived not only from methanotrophic but also from non-methanotrophic archaea, and that the relative contributions of the methanotrophic and non-methanotrophic archaea differed, depending on the biphytane compound. The vertical profiles and δ13C values of the neutral ether lipids were similar to those of the intact polar ether lipids, suggesting that neutral ether lipids derived from fossil archaea in the samples had mainly been lost by the time of sampling.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Organic Geochemistry - Volume 37, Issue 12, December 2006, Pages 1643-1654
نویسندگان
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