Polyester Microfibers Exposure Modulates Mytilus galloprovincialis Hemolymph Microbiome

Area of Science:

• Environmental Science
• Microbiology
• Marine Biology

Background:

• Microplastic (MP) pollution is a global concern, with synthetic microfibers (MFs) posing a significant threat to marine ecosystems.
• Filter-feeding invertebrates like bivalves accumulate MPs, leading to potential health issues and food chain transfer.
• Previous studies showed polyethylene terephthalate (PET) MFs induce stress responses in the mussel *Mytilus galloprovincialis*.

Purpose of the Study:

• To investigate the effects of PET-MF exposure on the hemolymph microbiome of *Mytilus galloprovincialis*.
• To determine if PET-MFs alter bacterial community composition in mussel hemolymph.
• To assess the impact of different PET-MF concentrations on microbial communities.

Main Methods:

• Exposure of *Mytilus galloprovincialis* to PET-MFs (10 and 100 μg/L) for 96 hours.
• Analysis of hemolymph microbiome composition using 16S rRNA gene amplification and sequencing.
• Evaluation of changes at phylum, family, and genus levels.

Main Results:

• PET-MF exposure significantly altered the bacterial community composition in mussel hemolymph.
• Stronger effects on microbial communities were observed at the lower concentration of 10 μg/L.
• Changes in the hemolymph microbiome were detected at multiple taxonomic levels.

Conclusions:

• PET-MFs disrupt the host-associated microbial communities in bivalves.
• The mussel hemolymph microbiome is sensitive to microplastic pollution.
• Understanding these microbiome alterations is crucial for assessing the ecological risks of microplastic contamination.