Plastic-inhabiting fungi in marine environments and PCL degradation activity

Abstract

Plastic waste has a negative impact on marine ecosystems and the quantity of this source of anthropogenic pollution continues to increase. Several studies have investigated plastic biodegradation using various microorganisms. In this study, we isolated fungi from polyethylene terephthalate (PET) waste on Korean seacoasts and evaluated their ability to degrade plastic by comparing the diameters of the clear zones they formed on polycaprolactone (PCL) agar. We isolated 262 strains from 47 plastic waste sources and identified 108 fungal species via molecular methods. The PCL agar assay revealed that 87 species presented with varying degrees of PCL degradation capacity. Among them, certain fungal species were strong PCL degraders. The present study demonstrated the possibility that some fungi inhabiting plastic could potentially degrade it in the marine environment. We believe that the discoveries made herein lay theoretical and practical foundations for the development of novel bioremediation systems for marine plastispheres and help mitigate the environmental pollution issues related to plastic wastes.

Microbial hitchhikers on microplastics: The exchange of aquatic microbes across distinct aquatic habitats

“…This might suggest that microplastic pollution potentially increases the abundance of parasitic fungi in coastal communities, but the mechanism behind it is unclear (note that the relative abundance of Bacillariophyta—including diatoms as common host of chytrids—was similar in all sea (MP+/−) communities). The enrichment of fungal Cladosporium and Plectosphaerella taxa has been evidenced in aquatic habitats in previous studies (Forero‐López et al, 2022; Lacerda et al, 2020), suggesting their plastic‐degrading potentials (Kim et al, 2022; Srikanth et al, 2022). These findings do not merely support that a subset of aquatic microbes is enriched on the plastisphere but also highlight relevant ecological roles in biodegradation processes.…”

Diversity of Cladosporium (Cladosporiales, Cladosporiaceae) species in marine environments and report on five new species

“…Seaweeds can accumulate in sediments and become nutrients for saprobes, such as Cladosporium . Recently, plastic waste has been flowing into the marine environments, and Cladosporium species isolated from such environments have been shown to possess the ability to degrade plastics ( Kim et al 2022 ; Zhang et al 2022 ).…”

Five Previously Unrecorded Fungal Species Isolated from Marine Plastic Wastes in South Korea

“…The plastic-degrading ability of the five species was evaluated using PCL agar (Kim et al. [ 24 ]). The species could degrade plastic but were categorized as weak PCL degraders.…”

“…Polyethylene terephthalate (PET) plastic wastes buried in mudflats and sea sand were collected from six sites in South Korea in April 2018 ( Table 1 , Figure 1 ). After sampling, decontamination and fungal isolation process were performed as described in the previous research [ 24 ]. Pure fungal isolates were stored in 20% (v/v) glycerol at −80 °C and deposited in the Seoul National University Fungus Collection (SFC).…”

“…Recently, we investigated the fungal diversity in a marine plastisphere based on culturomics and evaluated their ability to degrade polycaprolactone (PCL) [ 24 ] as part of the Marine Fungal Resource Bank project. While conducting this diversity study, we identified five species that were recorded for the first time in South Korea.…”