气候变化领域集成服务门户(CCPortal): Iron-oxidizer hotspots formed by intermittent oxic

CCPortal

DOI	10.1038/s41561-019-0509-1
	Iron-oxidizer hotspots formed by intermittent oxic–anoxic fluid mixing in fractured rocks
	Bochet O.; Bethencourt L.; Dufresne A.; Farasin J.; Pédrot M.; Labasque T.; Chatton E.; Lavenant N.; Petton C.; Abbott B.W.; Aquilina L.; Le Borgne T.
发表日期	2020
ISSN	17520894
卷号	13 期号:2
英文摘要	Subsurface environments host most of the fresh water on Earth as well as diverse microorganisms that may constitute a significant part of the biosphere. However, the dynamics and spatial distribution of subsurface microorganisms and their response to hydrological processes are poorly understood. Here we used chemical and metagenomic analyses of groundwater in a fractured rock aquifer in western France to determine the role of fractures in the formation of deep microbial hotspots in the subsurface. The majority of fractures, sampled in a 130-m-deep borehole, were anoxic, but a fracture carrying oxic groundwater was detected at 54-m depth, associated with a fivefold increase in the abundance of iron-oxidizing bacteria. We developed a mechanistic model of fluid flow and mixing in fractures and found that such microbial hotspots are sustained by the mixing of fluids with contrasting redox chemistries at intersections of fractures. The model predicts that metre-scale changes in near-surface water table levels cause intermittent oxygen delivery through deep fractures, which can extend the depth of the habitable zone for iron-oxidizing bacteria hundreds of metres into the subsurface. Given that fractures are ubiquitous at multiple scales in the subsurface, such deep microbial hotspots may substantially influence microbial communities and their effect on Earth’s biogeochemical cycles. © 2020, The Author(s), under exclusive licence to Springer Nature Limited.
语种	英语
scopus关键词	aquifer; bacterium; biogeochemical cycle; borehole; fluid flow; fracture zone; iron oxide; microbial community; spatial distribution; water table; France; Bacteria (microorganisms)
来源期刊	Nature Geoscience
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/124516
作者单位	University of Rennes, CNRS, Géosciences Rennes, UMR 6118, Rennes, France; University of Rennes, CNRS, Ecobio, UMR 6553, Rennes, France; Department of Plant and Wildlife Sciences, Brigham Young University, Provo, UT, United States
推荐引用方式 GB/T 7714	Bochet O.,Bethencourt L.,Dufresne A.,等. Iron-oxidizer hotspots formed by intermittent oxic–anoxic fluid mixing in fractured rocks[J],2020,13(2).
APA	Bochet O..,Bethencourt L..,Dufresne A..,Farasin J..,Pédrot M..,...&Le Borgne T..(2020).Iron-oxidizer hotspots formed by intermittent oxic–anoxic fluid mixing in fractured rocks.Nature Geoscience,13(2).
MLA	Bochet O.,et al."Iron-oxidizer hotspots formed by intermittent oxic–anoxic fluid mixing in fractured rocks".Nature Geoscience 13.2(2020).