PVC Biodegradation Potential of Native Fungal Strains From Mt. Hood National and Tillamook State Forests

Polyvinyl chloride (PVC) is a toxic, degradation-resistant environmental waste product. Recent research has revealed fungal enzymatic activity capable of biodegrading plastics. As PVC infiltrates local environments, it becomes imperative to determine the adaptability of local fungi to PVC substrates. In this experiment, 100 local native fungal strains sampled from the Tillamook State and Mt. Hood National forests and one commercial strain of common oyster mushroom were investigated for their ability to colonize and digest PVC by direct isolation on 0.1% and 0.2% PVC-enriched limited growth media. Substrates for positive cultures were imaged using Fourier transform infrared spectroscopy to analyze potential polymeric degradation. Out of 100 strains, only the commercial Pleurotus ostreatus actively colonized PVC-enriched limited growth media, and none of the strains exhibited clearance zones consistent with recent research. FTIR data between samples and control reveal no detectable shifts between characteristic peaks at 3300, 1633, and 1033 cm-1 consistent with agarose in the limited media. Fungal biodegradation of PVC, agar, or both, is unclear from these data. Further experimentation includes the development of more homogenous PVC suspensions in growth media, liquid culture without agar, and optimization of fungal culturing and co-culturing with regards to time, heat, nutrients, pH, and other critical growth factors.