Abstract

Plastic waste is widespread throughout the Laurentian Great Lakes watershed. During environmental exposure, plastic undergoes abiotic and biotic degradation. The presence of novel plastic substrates coupled with rapid microbial turnover may lead to selection for or evolution of metabolic pathways and enzymes with enhanced biodegradation capabilities. This study investigated the biodegradation potential of bacteria isolated from debris accumulation hotspots - stormwater retention ponds, storm drains, and tributaries - in the Lake Ontario watershed within Rochester, New York. Bacterial isolates were exposed to commonly littered plastics for 240 d: cellulose acetate from smoked cigarette filters, high-density polyethylene from takeout shopping bags, polypropylene from chip bags, and expanded polystyrene from packaging foam. Biodegradation was assessed by Fourier-Transform Infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and weight loss measurements. SEM images had biofilm formation on all tested polymers, but surface change results were insignificant. Polymer weight loss and FTIR evidence were polymer- and species-specific, with most dramatic changes on cellulose acetate with Rahnella sp., Serratia sp., Pseudomonas putida, Citrobacter sp., and Escherichia coli. Unfortunately, environmental persistence is present among all of these polymers as degradation of their backbones was not present. Understanding the microbial species and potential rate of degradation for different types of polymers  is crucial for assessing the environmental fate of household plastic debris and for future development of plastic-degradation as a mechanism for remediation.

Library of Congress Subject Headings

Plastics--Biodegradation; Fourier transform infrared spectroscopy; Scanning electron microscopy

Publication Date

12-1-2025

Document Type

Thesis

Student Type

Graduate

Degree Name

Environmental Science (MS)

College

College of Science

Advisor

Christy Tyler

Advisor/Committee Member

Andre Hudson

Advisor/Committee Member

Nathan Eddingsaas

Campus

RIT – Main Campus

Plan Codes

ENVS-MS

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