What role do biofilms on microplastics play in viral dynamics?

Answer

Act as a reservoir for viruses. 1, 2, 3, 4, 5

• Guideline framing:

  • Biofilms commonly form on environmental microplastics and can harbor microorganisms, potentially including pathogens, thereby altering particle fate and biological effects 1. Though these guidelines emphasize uncertainty in exposure quantification, they consistently recognize biofilm-colonized plastics as microbial harbors rather than antiviral surfaces 6.

• Highest-quality, most recent research supporting mechanism:

  • Hospital sewage study: viral genomes (e.g., Norovirus, Adenovirus) were detected on biofilm-coated microplastics while absent from treated water, indicating microplastics served as reservoirs/carriers of viral pathogens 2.
  • Marine and aquaculture contexts: microplastic biofilms host specialized viral assemblages, virulence factors, and ARGs, supporting reservoir and gene-transfer roles within the plastisphere 3, 4.
  • Reviews (2025–2026): converge that biofilm/eco-corona on microplastics promotes viral adsorption, persistence, and transport—functions consistent with a reservoir, not inactivation or mutation inhibition 7, 5.

• Pitfalls/caveats:

  • While biofilms may modulate surface chemistry, there is no high-quality evidence that they prevent attachment, accelerate inactivation, or inhibit mutations across viruses; instead, data point toward sustained carriage and potential persistence 1, 2, 3.