Related Experiment Video
Updated: Jun 25, 2026
09:38
Single-throughput Complementary High-resolution Analytical Techniques for Characterizing Complex Natural Organic Matter Mixtures
Published on: January 7, 2019
Machine learning uncovers tidal DOM transformations and keystone molecules via FT-ICR MS and reactomics for estuarine
Guosheng Zhao1, Longfei Wang2, Yi Li2
1State Key Laboratory of Water Cycle and Water Security, College of Environment, Hohai University, Nanjing 210098, China.
Journal of Environmental Sciences (China)
|June 23, 2026
Summary
Tidal cycles significantly alter estuarine dissolved organic matter (DOM), promoting humification and nitrogen-sulfur compound accumulation. Advanced techniques revealed microbial pathways and identified key molecular features predicting biodegradable DOM and regulating sulfur cycling.
Area of Science:
- Environmental Chemistry
- Geochemistry
- Microbial Ecology
Background:
- Estuarine dissolved organic matter (DOM) dynamics are crucial for biogeochemical cycles.
- Tidal forces significantly influence estuarine environments, yet molecular-level transformations remain poorly understood.
- Nitrogen and sulfur cycling in estuaries are complex and linked to DOM composition.
Purpose of the Study:
- To investigate tidal-driven DOM transformation pathways in estuarine sediments.
- To understand the role of DOM in nitrogen and sulfur biogeochemical cycles under tidal influence.
- To identify molecular characteristics and microbial processes governing DOM fate during tidal cycles.
Main Methods:
- Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) for detailed DOM characterization.
- Reaction omics using paired mass distance (PMD) networks to infer molecular transformation pathways.
- Machine learning (ML) models (XGBoost, LightGBM) to identify key DOM predictors.
Main Results:
- Tidal cycling enhanced DOM humification, increasing the O/C ratio and promoting nitrogen (CHON) and sulfur (CHONS) compound accumulation, especially in deeper sediments.
- ML models identified high molecular weight, elevated N/C, and S/C ratios as key predictors of biodegradable DOM.
- PMD networks revealed microbially mediated transformations (dealkylation, amide hydrolysis, desulfonation) and highlighted sulfur-rich compounds (CHOS) as critical regulators of sulfur cycling.
Conclusions:
- Tidal cycles profoundly impact estuarine DOM composition and transformation, influencing humification and nutrient cycling.
- Specific molecular features and sulfur-containing compounds play pivotal roles in estuarine biogeochemical processes and microbial community function.
- Integrated analytical approaches provide novel insights into complex DOM dynamics and microbial interactions in tidal estuaries.
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