Please use this identifier to cite or link to this item:
Full metadata record
DC FieldValueLanguage
dc.contributor.authorNichols, Robert S.en_US
dc.contributor.authorMartin, Patricken_US
dc.identifier.citationNichols, R. S. & Martin, P. (2021). Low biodegradability of dissolved organic matter from Southeast Asian peat-draining rivers. Journal of Geophysical Research: Biogeosciences, 126(6), e2020JG006182-.
dc.description.abstractSoutheast Asia's extensive tropical peatlands account for a significant proportion of the global riverine dissolved organic carbon (DOC) flux to the ocean. Peat-derived DOC is rich in polyphenolic compounds, the microbial degradation of which is thought to rely on extracellular phenol oxidases. Despite substantial interest in the biogeochemical fate of terrigenous DOC (tDOC), few studies have quantified phenol oxidase activity in aquatic environments, and microbial remineralization rates of tDOC have never been measured in Southeast Asia. Here, we assess the potential for using phenol oxidase assays as a proxy for tDOC biodegradation across peat-draining rivers and the coastal waters of Sarawak, Borneo, and report experimental measurements of microbial tDOC remineralization rates from this region. We first show that phenol oxidase assays in aquatic samples are problematic because of the rapid, pH-dependent autoxidation of the assay substrate. Our field measurements of phenol oxidase activity detected only substrate autoxidation, suggesting that real phenol oxidase activity was low or absent. Second, we report that peatland tDOC, collected from one of the few remaining intact peatlands on Borneo, showed at most very limited biodegradation (0%–6% loss of DOC, and 0%–12% loss of colored dissolved organic matter) during several 56-day incubation experiments at an in situ temperature of ∼30°C, even when diluted with seawater or amended with nutrients. Our results suggest that direct microbial respiration is perhaps not a major pathway for peatland tDOC remineralization in Southeast Asia and that photo-oxidation is more likely to control the fate of this carbon.en_US
dc.description.sponsorshipMinistry of Education (MOE)en_US
dc.description.sponsorshipNanyang Technological Universityen_US
dc.description.sponsorshipNational Research Foundation (NRF)en_US
dc.relation.ispartofJournal of Geophysical Research: Biogeosciencesen_US
dc.rights© 2021. The Authors. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.en_US
dc.titleLow biodegradability of dissolved organic matter from Southeast Asian peat-draining riversen_US
dc.typeJournal Articleen
dc.contributor.schoolAsian School of the Environmenten_US
dc.description.versionPublished versionen_US
dc.subject.keywordsPhenol Oxidaseen_US
dc.subject.keywordsDissolved Organic Matteren_US
dc.subject.keywordsTropical Peaten_US
dc.subject.keywordsDissolved Organic Carbonen_US
dc.subject.keywordsMicrobial Remineralizationen_US
dc.description.acknowledgementPatrick Martin acknowledges funding through a Nanyang Technological University Start-Up Grant, an Academic Research Fund Tier 1 grant from the Singapore Ministry of Education (RG 175/16), and a grant from the National Research Foundation under the Marine Science Research & Development Programme (MSRDP-P32).en_US
item.fulltextWith Fulltext-
Appears in Collections:ASE Journal Articles
Files in This Item:
File Description SizeFormat 
2020JG006182.pdf934.87 kBAdobe PDFView/Open

Citations 50

Updated on Dec 4, 2022

Web of ScienceTM
Citations 20

Updated on Dec 4, 2022

Page view(s)

Updated on Dec 8, 2022

Download(s) 50

Updated on Dec 8, 2022

Google ScholarTM




Items in DR-NTU are protected by copyright, with all rights reserved, unless otherwise indicated.