气候变化领域集成服务门户(CCPortal): Selective chemical degradation of silica sinters of the Taupo Volcanic Zone (New Zealand). Implications for early Earth and Astrobiology

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DOI	10.1111/gbi.12340
	Selective chemical degradation of silica sinters of the Taupo Volcanic Zone (New Zealand). Implications for early Earth and Astrobiology
	Chaves Torres L.; Kaur G.; Melbourne L.A.; Pancost R.D.
发表日期	2019
ISSN	14724677
起始页码	449
结束页码	464
卷号	17 期号:4
英文摘要	Most organic matter (OM) on Earth occurs as kerogen-like materials, that is naturally formed macromolecules insoluble with standard organic solvents. The formation of this insoluble organic matter (IOM) is a topic of much interest, especially when it limits the detection of compounds of geomicrobiological interest. For example, studies that search for biomarker evidence of life on early Earth or other planets usually use solvent-based extractions. This leaves behind a pool of OM as unexplored post-extraction residues, potentially containing diagnostic biomarkers. Since the IOM has an enhanced potential for preservation compared to soluble OM, analysing IOM-released biomarkers can also provide even deeper insights into the ecology of ancient settings, with implications for early Earth and Astrobiology investigations. Here, we analyse the prokaryotic lipid biosignature within soluble and IOM of the Taupo Volcanic Zone (TVZ) silica sinters, which are key analogues in the search for life. We apply sequential solvent extractions and a selective chemical degradation upon the post-solvent extraction residue. Moreover, we compare the IOM from TVZ sinters to analogous studies on peat and marine sediments to assess patterns in OM insolubilisation across the geosphere. Consistent with previous work, we find significant but variable proportions—1%–45% of the total prokaryotic lipids recovered—associated with IOM fractions. This occurs even in recently formed silica sinters, likely indicating inherent cell insolubility. Moreover, archaeal lipids seem more prone to insolubilisation as compared to the bacterial analogues, which might enhance their preservation and also bias overall biomarkers interpretation. These observations are similar to those observed in other settings, confirming that even in a setting where the OM derives predominantly from prokaryotic sources, patterns of IOM formation/occurrence are conserved. Differences with other settings, however, such as the occurrence of archaeol in IOM fractions, could be indicative of different mechanisms for IOM formation that merit further exploration. © 2019 John Wiley & Sons Ltd
关键词	biomarker chemical analysis degradation early Earth lipid membrane prokaryote silica sinter New Zealand North Island Taupo Volcanic Zone Archaea Bacteria (microorganisms)Prokaryota lipid silicon dioxide archaeon astrobiology astronomy bacterium chemistry metabolism New Zealand sediment Archaea Bacteria Earth (Planet)Evolution, Planetary Exobiology Geologic Sediments Lipids New Zealand Silicon Dioxide
语种	英语
来源机构	Geobiology
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/133225
推荐引用方式 GB/T 7714	Chaves Torres L.,Kaur G.,Melbourne L.A.,et al. Selective chemical degradation of silica sinters of the Taupo Volcanic Zone (New Zealand). Implications for early Earth and Astrobiology[J]. Geobiology,2019,17(4).
APA	Chaves Torres L.,Kaur G.,Melbourne L.A.,&Pancost R.D..(2019).Selective chemical degradation of silica sinters of the Taupo Volcanic Zone (New Zealand). Implications for early Earth and Astrobiology.,17(4).
MLA	Chaves Torres L.,et al."Selective chemical degradation of silica sinters of the Taupo Volcanic Zone (New Zealand). Implications for early Earth and Astrobiology".17.4(2019).