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ORIGINAL RESEARCH article

Front. Mar. Sci.
Sec. Marine Biogeochemistry
Volume 11 - 2024 | doi: 10.3389/fmars.2024.1469547

Molecular Characteristics of Dissolved Organic Matter in the PoreWater of "Challenger" Deep sediments, Mariana Trench

Provisionally accepted
Kexin Zheng Kexin Zheng 1Tingcang Hu Tingcang Hu 2Min Luo Min Luo 1*Linying Chen Linying Chen 1Yulin Qi Yulin Qi 3Jingqian Xie Jingqian Xie 1Duofu Chen Duofu Chen 1*
  • 1 Shanghai Ocean University, Shanghai, China
  • 2 Liaocheng University, Liaocheng, China
  • 3 Tianjin University, Tianjin, China

The final, formatted version of the article will be published soon.

    Hadal trenches (>6,000 m water depth) have been revealed as hotspots of organic carbon deposition and mineralization. Here, we present the molecular compositions of porewater dissolved organic matter at the "Challenger" Deep (Site MT02; 10,954 m water depth) sediments of the Mariana Trench and the adjacent abyssal plain sediments (Site MT04; 5,437 m water depth) using ultra highresolution Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR MS). The Challenger Deep sediments are characterized by higher abundance of recalcitrant compounds, mainly composed of highly unsaturated compounds (79.7%) and carboxyl-rich alicyclic molecules (57.1%), compared to the abyssal plain sediments (68.3%&51.5%). Principal component analysis suggests that TOC content in the sediments exerts an important control on the molecular characteristics of porewater DOM. It is likely that higher TOC content triggers elevated microbial-mediated organic matter mineralization, thereby forming more refractory organic matter compounds. These results improved the knowledge of the poorly-understood DOM compositions and microbial organic matter degradation in the ultra-deep, extreme ocean environment.

    Keywords: Molecular Characteristics 1, Dissolved Organic Matter 2, Challenger Deep 3, Mariana Trench 4, FT-ICR MS 5

    Received: 24 Jul 2024; Accepted: 07 Oct 2024.

    Copyright: © 2024 Zheng, Hu, Luo, Chen, Qi, Xie and Chen. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence:
    Min Luo, Shanghai Ocean University, Shanghai, China
    Duofu Chen, Shanghai Ocean University, Shanghai, China

    Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.