Theses and Dissertations

Date of Award

12-1-2025

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Biochemistry and Molecular Biology

First Advisor

Javier Macossay- Torres

Second Advisor

Cordelia Rasa

Third Advisor

Micheal Persans

Abstract

The widespread application and disposal of plastics, such as low-density polyethylene (LDPE) and polyethylene terephthalate (PET), have raised significant environmental health concerns. Because of each plastic’s stability and durability, these plastics exhibit limited natural degradation in the environment. Recently, the environmentally friendly biodegradation of plastics by living microorganisms has attracted more attention, as they can assist in the natural degradation process. In this study, the bacterial strain Bacillus subtilis ATCC6051 was used to degrade LDPE and PET for 60 days. To measure the degradation of low-density (LDPE) and polyethylene terephthalate (PET), the dry weight was taken, and physical characteristics were observed under an optical microscope and a scanning electron microscope (SEM) to determine whether any surface area of the films was biodegraded. Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR) and Atomic Force Microscope (AFM) analyses of the samples were used. The study presented a weight loss of 3.93% for LDPE and 1.02% for PET. SEM, optical microscope, and AFM analysis revealed structural changes, like cracks, tears, and roughness, compared to the controls. FTIR analysis demonstrated functional changes after incubation. This study offers potential insight into how bacteria can effectively biodegrade plastics.

Comments

Copyright 2025 Migdalia Flores. All Rights Reserved. https://proquest.com/docview/3292590303

Download

Included in

Biochemistry Commons

Share

COinS