| DOI: | 10.1038/ngeo2629
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| 论文题名: | A physiological role for Hg II during phototrophic growth |
| 作者: | Gregoire D.S.; Poulain A.J.
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| 刊名: | Nature Geoscience
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| ISSN: | 17520894
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| 出版年: | 2016
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| 卷: | 9, 期:2 | | 起始页码: | 121
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| 结束页码: | 125
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| 语种: | 英语
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| Scopus关键词: | bacterium
; bioaccumulation
; bioreactor
; enzyme activity
; growth rate
; homeostasis
; laboratory method
; methylation
; methylmercury
; microbial activity
; mixotrophy
; photoautotrophy
; photosynthesis
; redox conditions
; reduction
; Bacteria (microorganisms)
; Proteobacteria
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| 英文摘要: | The bioaccumulation of toxic monomethylmercury is influenced by the redox reactions that determine the amount of mercury (Hg) substrate-HgII or Hg0 (refs,)-that is available for methylation. Phototrophic microorganisms can reduce HgII to Hg0 (ref.). This reduction has been linked to a mixotrophic lifestyle, in which microbes gain energy photosynthetically but acquire diverse carbon compounds for biosynthesis from the environment. Photomixotrophs must maintain redox homeostasis to disperse excess reducing power due to the accumulation of reduced enzyme cofactors. Here we report laboratory experiments in which we exposed purple bacteria growing in a bioreactor to HgII and monitored Hg0 concentrations. We show that phototrophs use HgII as an electron sink to maintain redox homeostasis. Hg0 concentrations increased only when bacteria grew phototrophically, and when bacterial enzyme cofactor ratios indicated the presence of an intracellular redox imbalance. Under such conditions, bacterial growth rates increased with increasing HgII concentrations; when alternative electron sinks were added, Hg0 production decreased. We conclude that Hg can fulfil a physiological function in bacteria, and that photomixotrophs can modify the availability of Hg to methylation sites. © 2016 Macmillan Publishers Limited. |
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| 资源类型: | 期刊论文
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/106077
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| Appears in Collections: | 气候减缓与适应
科学计划与规划
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作者单位: | Biology Department, University of Ottawa, 30 Marie Curie, Ottawa, ON, Canada
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| Recommended Citation: | |
Gregoire D.S.,Poulain A.J.. A physiological role for Hg II during phototrophic growth[J]. Nature Geoscience,2016-01-01,9(2)
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