Date of Defense
14-4-2025 1:00 PM
Location
F3-033
Document Type
Dissertation Defense
Degree Name
Doctor of Philosophy in Cellular and Molecular Biology
College
COS
Department
Biology
First Advisor
Prof. Ruwaya AlKendi
Keywords
Biofilms, Bioluminescence, Hormesis, Hydrolase, Microbial communities, Plastic degradation, Quorum sensing, Soil Health
Abstract
Plastics, including microplastics, pose significant environmental threats due to their widespread presence and harmful ecological effects. This dissertation present three distinct, yet interconnected studies. First, a study on microplastic contamination in urban recreational parks was conducted in Al Ain, UAE. Results showed that low-density microplastics were present in 87% of soil samples, with FTIR analysis identifying synthetic polymers such as PE and PP. Additionally, these microplastics were found to negatively affect soil pH and moisture levels, emphasizing the need for enhanced monitoring and management strategies. Second, the effects of ground microplastics on Photobacterium leiognathi spp., a marine luminous bacterium, were examined. Findings revealed that microplastic exposure altered bioluminescence, cell viability, and influenced biofilm formation. Moreover, strain-specific responses indicated that ground microplastics disrupted quorum sensing, suggesting that these plastic particles act as environmental stressors on marine microorganisms. Lastly, to address polyethylene terephthalate persistence, synthetic microbial consortia or microbial communities (SynComs) were developed. These consortia demonstrated potentially for enhance PET degradation via synergistic microbial interactions, biofilm formation, and enzymatic activity. The study also conducted whole genome sequencing of two bacterial strains, Bacillus safensis F18 and Escherichia coli 9SH, that have potential application in plastic biodegradation. The B. safensis F18 possessed known plastic-degrading enzyme called hydrolase. Therefore, these findings offer promising strategies for mitigating plastic pollution through microbial degradation. Overall, this dissertation contributes to the understanding of microplastic pollution impacts and offer promising bioremediation approaches, with potential applications in industrial-scale waste management.
Included in
FROM MICROPLASTIC IMPACTS TO BIODEGRADATION SOLUTIONS: INVESTIGATING MICROPLASTIC CONTAMINATION, MICROBIAL RESPONSES, AND EFFICACY OF SYNTHETIC MICROBIAL CONSORTIA IN PLASTIC DEGRADATION
F3-033
Plastics, including microplastics, pose significant environmental threats due to their widespread presence and harmful ecological effects. This dissertation present three distinct, yet interconnected studies. First, a study on microplastic contamination in urban recreational parks was conducted in Al Ain, UAE. Results showed that low-density microplastics were present in 87% of soil samples, with FTIR analysis identifying synthetic polymers such as PE and PP. Additionally, these microplastics were found to negatively affect soil pH and moisture levels, emphasizing the need for enhanced monitoring and management strategies. Second, the effects of ground microplastics on Photobacterium leiognathi spp., a marine luminous bacterium, were examined. Findings revealed that microplastic exposure altered bioluminescence, cell viability, and influenced biofilm formation. Moreover, strain-specific responses indicated that ground microplastics disrupted quorum sensing, suggesting that these plastic particles act as environmental stressors on marine microorganisms. Lastly, to address polyethylene terephthalate persistence, synthetic microbial consortia or microbial communities (SynComs) were developed. These consortia demonstrated potentially for enhance PET degradation via synergistic microbial interactions, biofilm formation, and enzymatic activity. The study also conducted whole genome sequencing of two bacterial strains, Bacillus safensis F18 and Escherichia coli 9SH, that have potential application in plastic biodegradation. The B. safensis F18 possessed known plastic-degrading enzyme called hydrolase. Therefore, these findings offer promising strategies for mitigating plastic pollution through microbial degradation. Overall, this dissertation contributes to the understanding of microplastic pollution impacts and offer promising bioremediation approaches, with potential applications in industrial-scale waste management.