气候变化领域集成服务门户(CCPortal): Development of energetic and enzymatic limitations on microbial carbon cycling in soils

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DOI	10.1007/s10533-021-00781-z
	Development of energetic and enzymatic limitations on microbial carbon cycling in soils
	Naughton H.R.; Keiluweit M.; Tfaily M.M.; Dynes J.J.; Regier T.; Fendorf S.
发表日期	2021
ISSN	1682563
起始页码	191
结束页码	213
卷号	153 期号:2
英文摘要	Soil organic carbon (SOC) constitutes an important reservoir in the global carbon cycle that is vulnerable to transformation and loss from land use and climate change. Anoxic conditions protect SOC from microbial degradation through limiting the energetics of respiration and inhibiting extracellular oxidative enzymes. Given growing evidence of prevalent anaerobic microsites in upland soils, we designed an experiment testing the development of dissolved organic carbon (DOC) signatures of energetic and enzymatic limitations on microbial carbon utilization across simulated soil aggregates or peds. Reactors comprised a soil column “aggregate” underlying an advective “macropore” channel. Soils received downward diffusive inputs of aerated porewater media with added nitrate, sulfate, or no amendment—where native ferrihydrite served as dominant anaerobic terminal electron acceptor (TEA). After 40 days, added nitrate resulted in highest bulk respiration and DOC production while sulfate did not differ from the control. Nominal oxidation state of carbon (NOSC) was higher (more favorable) with added TEAs at soil surfaces and decreased with depth, while NOSC in the non-amended soil remained lower and constant with depth. DOC generally increased with depth, which along with decreasing NOSC values indicates joint electron-donor and acceptor control over respiration energetics. Of all organic compound classes, only the relative abundance of phenolics increased between 0 and 0.5 cm depth, which aligns with the oxic-anoxic transition and suggests oxidative enzyme inhibition. Our results suggest that oxygen limitation within upland soil aggregates may preserve SOC via both energetic and enzymatic C protection mechanisms, which are vulnerable upon exposure to oxygen. © 2021, The Author(s), under exclusive licence to Springer Nature Switzerland AG.
英文关键词	Extracellular oxidative enzymes; Microbial carbon utilization; Redox chemistry; Soil organic carbon
语种	英语
来源期刊	Biogeochemistry
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/184609
作者单位	Earth System Science Department, Stanford University, Stanford, CA 94305, United States; Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA 01003, United States; Department of Environmental Sciences, The University of Arizona, Tucson, AZ 85719, United States; Canadian Light Source Inc., Saskatoon, SK, Canada; Climate and Ecosystem Sciences Division, Lawrence Berkeley National Lab, Berkeley, CA 94720, United States
推荐引用方式 GB/T 7714	Naughton H.R.,Keiluweit M.,Tfaily M.M.,et al. Development of energetic and enzymatic limitations on microbial carbon cycling in soils[J],2021,153(2).
APA	Naughton H.R.,Keiluweit M.,Tfaily M.M.,Dynes J.J.,Regier T.,&Fendorf S..(2021).Development of energetic and enzymatic limitations on microbial carbon cycling in soils.Biogeochemistry,153(2).
MLA	Naughton H.R.,et al."Development of energetic and enzymatic limitations on microbial carbon cycling in soils".Biogeochemistry 153.2(2021).