DOI: 10.1073/pnas.0507601102
论文题名: Microbial origin of excess methane in glacial ice and implications for life on Mars
作者: Tung H.C. ; Bramall N.E. ; Price P.B.
刊名: Proceedings of the National Academy of Sciences of the United States of America
ISSN: 0027-8424
出版年: 2005
卷: 102, 期: 51 起始页码: 18292
结束页码: 18296
语种: 英语
英文关键词: Metabolism by methanogenic archaea
; Methane in glacial ice
; Methanogens on Mars
; Origin of microbes in glacial ice
Scopus关键词: amino acid
; bacterial DNA
; ice
; methane
; Archaebacterium
; article
; astronomy
; autofluorescence
; bacterial metabolism
; climate change
; controlled study
; DNA damage
; DNA repair
; Greenland
; ice core record
; macromolecule
; metabolic rate
; Methanobacterium
; nonhuman
; priority journal
; temperature
; Exobiology
; Extraterrestrial Environment
; Greenland
; Ice Cover
; Mars
; Methane
; Temperature
; Archaea
; Bacteria (microorganisms)
; Methanobacterium
英文摘要: Methane trapped in the 3,053-m-deep Greenland Ice Sheet Project 2 ice core provides an important record of millennial-scale climate change over the last 110,000 yr. However, at several depths in the lowest 90 m of the ice core, the methane concentration is up to an order of magnitude higher than at other depths. At those depths we have discovered methanogenic archaea, the in situ metabolism of which accounts for the excess methane. The total concentration of all types of microbes we measured with direct counts of Syto-23-stained cells tracks the excess of methanogens that we identified by their F420 autofluorescence and provides independent evidence for anomalous layers. The metabolic rate we estimated for microbes at those depths is consistent with the Arrhenius relation for rates found earlier for microbes imprisoned in rock, sediment, and ice. It is roughly the same as the rate of spontaneous macromolecular damage inferred from laboratory data, suggesting that microbes imprisoned in ice expend metabolic energy mainly to repair damage to DNA and amino acids rather than to grow. Equating the loss rate of methane recently discovered in the Martian atmosphere to the production rate by possible methanogens, we estimate that a possible Martian habitat would be at a temperature of ≈0°C and that the concentration, if uniformly distributed in a 10-m-thick layer, would be ≈1 cell per ml. © 2005 by The National Academy of Sciences of the USA. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/162480
Appears in Collections: 气候变化与战略
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作者单位: Tung, H.C., Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA 94720, United States; Bramall, N.E., Department of Physics, University of California, Berkeley, CA 94720, United States; Price, P.B., Department of Physics, University of California, Berkeley, CA 94720, United States
Recommended Citation:
Tung H.C.,Bramall N.E.,Price P.B.. Microbial origin of excess methane in glacial ice and implications for life on Mars[J]. Proceedings of the National Academy of Sciences of the United States of America,2005-01-01,102(51)