气候变化领域集成服务门户(CCPortal): In situ microbial metabolism as a cause of gas anomalies in ice

CCPortal

DOI	10.1073/pnas.0803763105
	In situ microbial metabolism as a cause of gas anomalies in ice
	Rohde R.A.; Price P.B.; Bay R.C.; Bramall N.E.
发表日期	2008
ISSN	0027-8424
起始页码	8667
结束页码	8672
卷号	105 期号:25
英文摘要	Isolated spikes of anomalously high concentrations of N2O have been reported at depths in Greenland and Antarctic ice cores corresponding to narrow time intervals over the past ≈105 years. Now, using a calibrated spectrofluorimeter to map protein-bound Trp, a proxy for microbes, versus depth in the 3,053-m GISP2 ice core, we find six depths at which localized spikes of high cell concentrations coincide with N2O spikes. We show that the excess gases are consistent with accumulation of in situ metabolic wastes during residence times of the excess microbes in the ice. Because of sparseness of N2O measurements and our spectrofluorimetry versus depth, the total number of microbially produced N2O spikes in GISP2 is probably much larger than six. Spikes of excess methanogens coincident with CH4 spikes are found at three depths in the bottom 3% of GISP2, most likely because of methanogenic metabolism in the underlying silty ice, followed by turbulent flow of the lowest ≈90 m of ice. The apparent rates of in situ production of N2O and CH4 spikes by metabolism are observed to be consistent with a single activation energy, U, and maintain proportionality to exp(-UIRT) over the entire temperature range down to -40°C. Fluorescence of nonmicrobial aerosols in GISP2 ice is distinguishable from microbial fluorescence by its different emission spectra. Our spectrof luorimetric scans throughout the GISP2 ice core lead us to conclude that both microbes and nonmicrobial aerosols are deposited in discontinuous bursts, which may provide a tool for studying wind storms in the distant past. © 2008 by The National Academy of Sciences of the USA.
英文关键词	Climate; Ice cores; N2O; Proxy for dust storms; Scanning fluorimetry
语种	英语
scopus关键词	nitrogen oxide; article; flame photometry; fluorescence analysis; methanogen; microbial metabolism; priority journal; spectrofluorometry; turbulent flow; Bacteria; Fluorometry; Greenland; Ice Cover; Methane; Microscopy, Fluorescence; Nitrogen Dioxide; Temperature; Water Microbiology
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/159174
作者单位	Rohde, R.A., Physics Department, University of California, Berkeley, CA 94720, United States; Price, P.B., Physics Department, University of California, Berkeley, CA 94720, United States; Bay, R.C., Physics Department, University of California, Berkeley, CA 94720, United States; Bramall, N.E., Physics Department, University of California, Berkeley, CA 94720, United States, National Aeronautics and Space Administration Ames Research Center, Moffett Field, CA 14035, United States
推荐引用方式 GB/T 7714	Rohde R.A.,Price P.B.,Bay R.C.,et al. In situ microbial metabolism as a cause of gas anomalies in ice[J],2008,105(25).
APA	Rohde R.A.,Price P.B.,Bay R.C.,&Bramall N.E..(2008).In situ microbial metabolism as a cause of gas anomalies in ice.Proceedings of the National Academy of Sciences of the United States of America,105(25).
MLA	Rohde R.A.,et al."In situ microbial metabolism as a cause of gas anomalies in ice".Proceedings of the National Academy of Sciences of the United States of America 105.25(2008).