Preliminary Survey of Fungal Communities Across a Plastics/No Plastics Transition on an Oregon Beach

Abstract Plastics pose an increasing and significant threat to both human and environmental health. While many fungi can degrade a variety of organic polymers, investigations into which fungi possess the potential to remediate environmental plastics contamination have only recently become a priority. To help address this need, we tested the null hypothesis that chronic plastics contamination has no impact on the fungal communities across a plastics/no plastics transition in a beach sand in northern Oregon. We used sieving and binocular microscopy of microplastics (particle size, 12.6µm +/-5.5µm, detection range 1-5000µm) to confirm the plastics/no plastics transition. We used paired plot design to collect samples across this transition and analyzed the fungal communities using high-throughput DNA sequencing methods for fungal ITS-2. Results indicated that the beach sand contaminated with plastics held an extensive fungal community, while un-contaminated sand held no fungal community at all. System dominants included Acremonium and Penicillium , both free-living ascomycete fungi that have shown plastics-degrading capabilities in lab studies, and the ectomycorrhizal genus, Russula a symbiotic fungus that has known plastics-degrading enzyme capabilities. Also amongst dominant genera was a human fungal pathogen (genus Malassezia ) that causes chronic skin disease. These results provide new fungal models for further studies of fungal and ectomycorrhizal remediation of plastics contaminated contaminated beach sand.