eDNA-based microbial communities enable rapid screening of sediment pollution

Area of Science:

• Environmental microbiology
• Coastal ecology
• Bioindicator research

Background:

• Microbial communities are vital bioindicators for coastal ecosystem health.
• Current studies often focus on descriptive taxonomy, limiting detailed ecological assessments.
• Understanding microbial responses to sediment chemistry is crucial for effective environmental monitoring.

Purpose of the Study:

• To investigate the relationship between sediment chemistry and microbial community structure using environmental DNA (eDNA).
• To identify specific microbial taxa that indicate chemical pollution levels in Gyeonggi Bay.
• To evaluate the utility of taxon-based versus diversity-based metrics for assessing coastal contamination.

Main Methods:

• Analysis of eDNA-based microbial community structure across 82 stations in Gyeonggi Bay.
• Correlation analysis between pollutant concentrations and microbial taxa (Shannon diversity, Firmicutes/Proteobacteria ratio).
• Identification of key indicator taxa using statistical significance, correlation strength, and field consistency (LEfSe analysis).

Main Results:

• The Firmicutes/Proteobacteria ratio significantly increased with higher contamination levels, unlike Shannon diversity.
• Specific microbial families (Peptostreptococcaceae, Pirellulaceae) and genera (Romboutsia, Trichococcus, Woeseia) were identified as indicators of pollution.
• Spatial mapping confirmed strong correlations between microbial indicators and sediment quality gradients.

Conclusions:

• Specific microbial taxa provide contaminant-specific signals, offering complementary information to diversity indices.
• Taxon-based microbial indicators can be integrated into sediment quality assessment frameworks for enhanced coastal monitoring.
• These findings highlight the potential of microbial communities as precise bioindicators of chemical pollution.