气候变化领域集成服务门户(CCPortal): Influence of temperature on the δ13C values and distribution of methanotroph-related hopanoids in Sphagnum-dominated peat bogs

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DOI	10.1111/gbi.12389
	Influence of temperature on the δ13C values and distribution of methanotroph-related hopanoids in Sphagnum-dominated peat bogs
	van Winden J.F.; Talbot H.M.; Reichart G.-J.; McNamara N.P.; Benthien A.; Sinninghe Damsté J.S.
发表日期	2020
ISSN	14724677
起始页码	497
结束页码	507
卷号	18 期号:4
英文摘要	Methane emissions from peat bogs are mitigated by methanotrophs, which live in symbiosis with peat moss (e.g. Sphagnum). Here, we investigate the influence of temperature and resultant changes in methane fluxes on Sphagnum and methanotroph-related biomarkers, evaluating their potential as proxies in ancient bogs. A pulse-chase experiment using 13C-labelled methane in the field clearly showed label uptake in diploptene, a biomarker for methanotrophs, demonstrating in situ methanotrophic activity in Sphagnum under natural conditions. Peat cores containing live Sphagnum were incubated at 5, 10, 15, 20 and 25°C for two months, causing differences in net methane fluxes. The natural δ13C values of diploptene extracted from Sphagnum showed a strong correlation with temperature and methane production. The δ13C values ranged from −34‰ at 5°C to −41‰ at 25°C. These results are best explained by enhanced expression of the methanotrophic enzymatic isotope effect at higher methane concentrations. Hence, δ13C values of diploptene, or its diagenetic products, potentially provide a useful tool to assess methanotrophic activity in past environments. Increased methane fluxes towards Sphagnum did not affect δ13C values of bulk Sphagnum and its specific marker, the C23 n-alkane. The concentration of methanotroph-specific bacteriohopanepolyols (BHPs), aminobacteriohopanetetrol (aminotetrol, characteristic for type II and to a lesser extent type I methanotrophs) and aminobacteriohopanepentol (aminopentol, a marker for type I methanotrophs) showed a non-linear response to increased methane fluxes, with relatively high abundances at 25°C compared to those at 20°C or below. Aminotetrol was more abundant than aminopentol, in contrast to similar abundances of aminotetrol and aminopentol in fresh Sphagnum. This probably indicates that type II methanotrophs became prevalent under the experimental conditions relative to type I methanotrophs. Even though BHP concentrations may not directly reflect bacterial activity, they may provide insight into the presence of different types of methanotrophs. © 2020 The Authors. Geobiology published by John Wiley & Sons Ltd
关键词	biomarker carbon isotope concentration (composition)enzyme enzyme activity methane moss peatland symbiosis temperature effect Bacteria (microorganisms)Bryophyta Methylococcaceae Methylocystaceae Sphagnum
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/133181
推荐引用方式 GB/T 7714	van Winden J.F.,Talbot H.M.,Reichart G.-J.,et al. Influence of temperature on the δ13C values and distribution of methanotroph-related hopanoids in Sphagnum-dominated peat bogs[J]. Geobiology,2020,18(4).
APA	van Winden J.F.,Talbot H.M.,Reichart G.-J.,McNamara N.P.,Benthien A.,&Sinninghe Damsté J.S..(2020).Influence of temperature on the δ13C values and distribution of methanotroph-related hopanoids in Sphagnum-dominated peat bogs.,18(4).
MLA	van Winden J.F.,et al."Influence of temperature on the δ13C values and distribution of methanotroph-related hopanoids in Sphagnum-dominated peat bogs".18.4(2020).