UC Santa Barbara

Plastics have become indispensable in our daily lives due to their versatility and durability. However, their widespread use has led to significant environmental concerns and toxicological risks for living organisms. To mitigate these issues, it is crucial to understand the sources, pathways, and environmental fate of plastics in order to implement effective solutions. Single-use plastics, particularly multilayer packaging, is a major contributor to plastic waste yet current waste management strategies primarily rely on landfill disposal due to challenges recycling these complex materials. This dissertation research aimed to explore plastic biodegradation as a potential solution for waste management by investigating the colonization of hydrocarbonoclastic and cellulolytic bacterial consortia from hydrocarbon seep sediment on plastic surfaces found in multilayer packaging films. Through gene sequencing, the first study identified specific hydrocarbon-degrading and cellulolytic bacterial communities that are likely involved in plastic biodegradation. A subsequent study used analytical techniques namely attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), scanning electron microscopy (SEM), contact-angle goniometry, and differential scanning calorimetry to examine both abiotic and biodegradation occurring on the surface and bulk polymer. Finally, a comprehensive method was developed for extracting microplastics of diverse morphology and type from field soils, enabling the assessment of their pathways and fates within solid matrices.