Date of Award
2025
Degree Type
Thesis
Degree Name
Master of Science in Chemical Engineering (MSChE)
Department
Chemical Engineering
First Advisor
Arijit Bose
Abstract
Plastic waste is a leading global pollutant with increasing concerns, as recent studies have shown that these wastes are not only concentrated on a macro scale but on a micro and nano scale. These micro- and nano- sized plastic particles, denoted as MPs and NPs, have been measured in marine and freshwater sources, air, food products, and within biosolids expelled from organisms, including humans. Due to their small size, MNPs are entering organisms through inhalation, ingestion, or dermal absorption. [1] Humans are ingesting MNPs daily, with median rates of approximately 200 ng/capita/day for children and 600 ng/capita/day for adults. [2] The recent discovery of MNPs in human wastes, bodily fluids, and tissues has caused further studies on the impacts these wastes could pose to the fragile ecosystems within organisms, such as in the gastrointestinal tract. The microbiota within the human GI tract has a multitude of responsibilities that have a wide variety of impacts on overall health. Bacteria that make up GI microbiota are not only responsible for nutrient uptake and storage, but also for communication with and development of healthy immune cells and system. [3] If the presence of MNPs show any negative impact on the GI microbiota and balance is disrupted, further health implications such as compromised immune systems and changes in mental health may occur. The goal of this thesis is to investigate the interactions between plastics and bacterial species found in the environment and human GI tract using microscopy methods, such as scanning electron and fluorescence microscopy.
The chosen plastics were characterized, and culturing procedures, sample preparation, and assaying techniques were described. Scanning electron microscopy image qualitative analysis showed a distinct difference in cellular colony and biofilm growth and assembly with respect to varying plastic type, surface geometries, and cell type. Bacterial biofilm and cell vitality were quantified by MTT assay and LIVE/DEAD staining paired with epifluorescence imaging.
Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.
Recommended Citation
Zmich, Jason, "PLASTICS AND THEIR INTERACTIONS WITH BACTERIAL BIOFILMS OF SYNECHOCOCCUS SP. PCC 7002 AND ESCHERICHIA COLI NISSLE 1917" (2025). Open Access Master's Theses. Paper 2644.
https://digitalcommons.uri.edu/theses/2644