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Microbial interaction patterns and nitrogen cycling regularities in lake sediments under different trophic conditions
Ziwei Wang1, Xiaohong Ruan1, Rongfu Li1
1Department of Hydrosciences, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, China; MOE Key Laboratory of Surficial Geochemistry, Nanjing University, Nanjing 210023, China.
The Science of the Total Environment
|October 20, 2023
Summary
Microbial interactions in lake sediments vary with nutrient levels, impacting nitrogen cycling. Carbon, sulfur, and iron cycles significantly influence nitrogen removal processes in eutrophic and mesotrophic environments.
Area of Science:
- Environmental Microbiology
- Biogeochemistry
- Ecology
Background:
- Nitrogen (N) cycling microbial communities are key to understanding lake biogeochemical processes.
- Eutrophication significantly alters microbial interactions and nutrient cycling in aquatic sediments.
- Investigating these interactions is vital for managing nitrogen accumulation in lakes.
Purpose of the Study:
- To explore microbial interactions within nitrogen cycling in lake sediments across varying trophic conditions.
- To determine the influence of biogenic elements on nitrogen cycling mechanisms.
- To elucidate how microbial networks differ between eutrophic and mesotrophic lake areas.
Main Methods:
- Sediment sampling from Taihu Lake across different trophic states and seasons (2015-2017).
- High-throughput sequencing to analyze microbial community structure.
- Molecular ecological network analysis to map microbial interactions and functional roles.
Main Results:
- Distinct microbial network structures were observed between lake areas with different trophic conditions.
- More eutrophic regions showed higher transfer efficiency, increased competition, and reduced niche differentiation.
- Carbon (C), sulfur (S), and iron (Fe) cycles strongly influenced the nitrogen cycle, affecting N removal and fixation processes.
Conclusions:
- Microbial community structure and function in lake sediments are strongly dictated by trophic status.
- Interactions between N-cycling microbes and other biogeochemical cycles (C, S, Fe) are critical for regulating nitrogen fate in lakes.
- Understanding these complex interactions is essential for predicting and managing nitrogen dynamics in aquatic ecosystems.
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