Master’s Discussion
The College of Science for Women, University of Baghdad discussed the Master’s thesis entitled “Bioremediation of Microplastic Pollutants in the Tigris River in Baghdad City, Iraq.”, presented by the postgraduate student (Ghufran Jaafar Hammood), in partial fulfillment of the requirements for the degree of Master in Biology/ Ecology, under the supervision of Prof. Dr. Fikrat M. Hassan / Dr. Saad Sabah Fakhry.
The thesis aimed to evaluate the ability of indigenous bacterial communities isolated from the Tigris River in Baghdad City to biodegrade plastic polymers under controlled laboratory conditions and to compare the biodegradation potential of three types of polymers: low-density polyethylene (LDPE), high-density polyethylene (HDPE), and polyethylene terephthalate (PET). It also aimed to identify the most efficient bacterial isolates and investigate enzyme activity associated with their ability to biodegrade plastic materials.
The thesis concluded that indigenous bacterial communities isolated from the Tigris River were capable of growing and interacting with the three studied plastic materials under laboratory conditions, resulting in partial changes in their chemical and surface structures. The results demonstrated differences in the biodegradation potential of the studied polymers, with LDPE showing the highest response to bacterial activity, followed by PET, whereas HDPE exhibited higher resistance to biodegradation during the experimental period. The study also identified promising bacterial isolates, particularly Pseudomonas aeruginosa and Bacillus subtilis, which exhibited enzymatic activity that may contribute to the biodegradation process. Overall, the findings provide an initial scientific basis for future studies aimed at developing more efficient biological approaches for mitigating plastic pollution in the Tigris River and other freshwater aquatic environments.
The thesis recommended further comprehensive investigations to assess plastic biodegradation of plastic materials by monitoring changes in polymer weight and carbon dioxide (CO2) evolution, correlating these with chemical transformations. It also suggests using genomic and metagenomic sequencing to identify relevant genes and metabolic pathways, and optimizing bacterial consortia particularly Pseudomonas and Bacillus strains to enhance biodegradation efficiency. Furthermore, advanced analytical techniques should be applied to evaluate structural and thermal property changes, while assessing the toxicity and environmental impact of biodegradation products. Finally, simulating natural weathering conditions, such as UV exposure and thermal pretreatment prior to bacterial treatment, is recommended to further accelerate biodegradation.
Final Grade for the Master’s Thesis : Excellent
