We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Plastic-Colonizing Fungi in the Eastern Mediterranean Sea: Community Structure and Physiological and Transcriptional Responses of Aspergillus to Pristine and Weathered PET
Summary
Scientists found that fungi—including some types of mold—naturally colonize plastic debris floating in the Mediterranean Sea, with certain fungi actually able to break down plastic and even attach to it more after it's been weathered by sun exposure. This matters because these fungi could eventually help us develop ways to biodegrade plastic waste, but it also raises questions about whether plastic debris in the ocean is becoming a floating habitat for organisms that might affect marine food chains, since plastic-eating fungi could enter the food web that ultimately reaches our plates.
Marine plastic debris provides persistent artificial substrates for microbial colonization, yet the fungal component of the plastisphere remains poorly characterized. Using ITS metabarcoding and culture-based isolation approaches, we characterized the early mycobiome associated with polyethylene, polypropylene, polystyrene, and polyethylene terephthalate (PET) plastic pellets deployed in an Eastern Mediterranean Sea (EMS) marina. The sequence-based communities were taxonomically heterogeneous, with only a limited effect of polymer type. Ascomycota, Zoopagomycota, and Basidiomycota were the dominant phyla identified by the ITS sequence analysis, while Linderina and Starmerella were the dominant genera. In contrast, the cultured isolates belonged exclusively to the phyla Ascomycota and Mucoromycota, with the Aspergillus genus accounting for 52.3% of the isolates. We further recorded physiological responses of 11 Aspergillus isolates to pristine and UV-weathered PET, including attachment, pigmentation, and plastic gravimetric weight loss. A. niger OC26 also exhibited strong peroxidase activity, together with a broad transcriptional response to PET exposure, including 216 upregulated genes and significant enrichment of peroxidase- and membrane-associated functions. UV weathering induced a limited but distinct additional transcriptional shift. Together, these findings indicate that early plastic-associated fungal communities in the EMS are taxonomically diverse, and include metabolically versatile Aspergillus strains that mount distinct physiological and transcriptional responses to PET exposure.