Chlordecone-contaminated epilithic biofilms show increased adsorption capacities

Area of Science:

• Environmental Science
• Ecotoxicology
• Microbiology

Background:

• Rivers in Guadeloupe and Martinique are heavily contaminated with chlordecone (CLD).
• Epilithic biofilms are crucial primary producers and food sources in these rivers.
• Biofilm viscoelastic properties can indicate pollution levels in tropical environments.

Purpose of the Study:

• To investigate the biochemical and molecular changes in epilithic biofilms due to CLD contamination.
• To understand the relationship between CLD pollution and biofilm properties.
• To explore microbial adaptation strategies to CLD in aquatic ecosystems.

Main Methods:

• Analysis of biochemical markers: fatty acids, pigments, and extracellular polymeric substances (EPS) monosaccharides.
• Molecular analysis using T-RFLP fingerprints for bacteria, archaea, and eukaryotes.
• Correlation of CLD levels with biofilm composition and microbial community structure.

Main Results:

• Significant links found between CLD pollution levels and biofilm biochemistry.
• High CLD concentrations correlated with modified EPS, specifically carbohydrates with enhanced adsorption and adhesion.
• Changes in microbial community composition were observed in response to CLD.

Conclusions:

• CLD pollution alters epilithic biofilm EPS, impacting their viscoelastic properties.
• Microorganisms may employ EPS to scavenge CLD, indicating an adaptation strategy.
• This research provides insights into the role of EPS in microbial adaptation to persistent pollutants.