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DOI	10.1007/s10533-021-00764-0
	Abiotic contribution to phenol oxidase activity across a manganese gradient in tropical forest soils
	Sanchez-Julia M.; Turner B.L.
发表日期	2021
ISSN	1682563
起始页码	33
结束页码	45
卷号	153 期号:1
英文摘要	Phenol oxidases are a group of extracellular enzymes that catalyze the oxidation of lignin and phenolic compounds in soil organic matter. Despite their importance, little is known about these enzymes in tropical soils, particularly the extent to which minerals like manganese (Mn) oxides contribute to the measured activity. We assayed phenol oxidase activity in surface and subsurface (A and B) horizons from 15 soil profiles representing a steep Mn gradient under a lowland tropical forest in Panama. Fresh and sterilized (autoclaved) soils were assayed to determine the abiotic contribution to activity. Assays were conducted using 5 mM l-DOPA substrate in bicarbonate buffer at pH 8.5. We also determined amorphous metal oxide concentrations, soil pH, organic matter, and effective cation exchange capacity (CEC). We found little difference in phenol oxidase activity between fresh and autoclaved soils, indicating a considerable abiotic contribution to substrate oxidation. Furthermore, phenol oxidase activity was similar in surface and subsurface soils, despite markedly lower organic matter at depth. Phenol oxidase activity was correlated positively with amorphous Mn oxide concentrations (extractable Mn determined by acidic ammonium oxalate extraction), suggesting a potential mechanism of abiotic oxidation. These results have important implications for understanding carbon dynamics in tropical soils, because they suggest that (1) a portion of organic matter turnover is mediated by abiotic oxidation via Mn oxides, and (2) conventional measures of phenol oxidase activity reflect abiotic oxidation rather than the activity of enzymes synthesized by the microbial community. © 2021, The Author(s), under exclusive licence to Springer Nature Switzerland AG part of Springer Nature.
英文关键词	Abiotic oxidation; Barro colorado island; Manganese; Phenol oxidase; Soil organic matter; Tropical forest
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/184622
作者单位	Smithsonian Tropical Research Institute, Apartado, Balboa, Ancon 0843-03092, Panama; Department of Ecology and Evolutionary Biology, Tulane University, 6823 St. Charles Avenue, Boggs 400, New Orleans, LA 70118, United States; Soil and Water Science Department, University of Florida, Gainesville, FL 32611, United States
推荐引用方式 GB/T 7714	Sanchez-Julia M.,Turner B.L.. Abiotic contribution to phenol oxidase activity across a manganese gradient in tropical forest soils[J],2021,153(1).
APA	Sanchez-Julia M.,&Turner B.L..(2021).Abiotic contribution to phenol oxidase activity across a manganese gradient in tropical forest soils.Biogeochemistry,153(1).
MLA	Sanchez-Julia M.,et al."Abiotic contribution to phenol oxidase activity across a manganese gradient in tropical forest soils".Biogeochemistry 153.1(2021).