Rapid microbial production of long-lived dissolved organic carbon in the global ocean
Abstract
Marine microbes have long been regarded as central to replenishing the ocean’s reservoir of recalcitrant dissolved organic matter (RDOM). However, molecular-level evidence for their role remains inconclusive because RDOM persists for years to millennia, far exceeding timescales accessible to laboratory experiments, and because conventional analytical approaches lack the resolution to discern structural isomers of RDOM that confer functionally important differences in persistence. Using polarity-based liquid chromatography coupled to ultrahigh-resolution mass spectrometry capable of discriminating RDOM isomer clusters, we reveal that marine microbial consortia rapidly (≤ 90 d) convert diverse organic substrates into RDOM with extensive structural isomerism that closely mirrors natural seawater RDOM. A subset of these microbially derived RDOM compounds exhibits near-ubiquitous occurrence (> 99%) in a global dataset and accumulates progressively in the ocean’s interior. Together, our findings substantiate the direct microbial contribution to the long-lived oceanic carbon reservoir through the rapid diversification of RDOM isomers, a mechanism that contributes to sustaining the complexity and long-term persistence of the planetary-scale carbon reservoir.
Article Details
Journal Info
Proceedings of the National Academy of Sciences
National Academy of Sciences
Authors (15)
Ruanhong Cai
Department of Ocean Science and Center for Ocean Research in Hong Kong and Macau, The Hong Kong University of Science and Technology
Oliver J. Lechtenfeld
Department of Environmental Analytical Chemistry, Research Group BioGeoOmics, Helmholtz Centre for Environmental Research
Andrew J. Tanentzap
Julian P. Sachs
School of Oceanography, University of Washington
Shuh‐Ji Kao
State Key Laboratory of Marine Resource Utilization in South China Sea and School of Marine Science and Engineering, Hainan University
Helena Osterholz
Marine Chemistry, Leibniz Institute for Baltic Sea Research Warnemünde
Zhenwei Yan
Department of Ocean Science and Center for Ocean Research in Hong Kong and Macau, The Hong Kong University of Science and Technology
Chen Zhao
Yuanbi Yi
Department of Ocean Science and Center for Ocean Research in Hong Kong and Macau, The Hong Kong University of Science and Technology
Penghui Li
Chuanlun Zhang
Department of Ocean Science and Engineering, Shenzhen Key Laboratory of Marine Archaea Geo-Omics, Southern University of Science and Technology
Nianzhi Jiao
Department of Marine Biology and Technology, College of Ocean and Earth Sciences and State Key Laboratory of Marine Environmental Science, Xiamen University
Boris P. Koch
Alfred-Wegener-Institut Helmholtz Zentrum für Polar- und Meeresforschung
Gerhard J. Herndl
Department of Functional and Evolutionary Ecology, University of Vienna
Ding He
Department of Ocean Science and Center for Ocean Research in Hong Kong and Macau, The Hong Kong University of Science and Technology