Repurposing plastic waste for production of antimicrobial compounds
A circular bioprocessing approach that converts biopolymer plastic waste into high-value antimicrobial secondary metabolites. Bacterial strains isolated from plastic-contaminated environments degrade biopolymers such as PHB and PLA, and the fermentation byproducts are being developed into bioactive antimicrobials and antifungals for material and pharmaceutical applications.
Overview
This research addresses two pressing challenges simultaneously: plastic waste accumulation and the growing need for novel antimicrobial compounds. The approach uses bacterial strains isolated from environments heavily contaminated with plastic waste to depolymerize biopolymers such as PHB, PLA, and thermoplastic starch. Rather than treating the degradation byproducts as waste, the process transforms them into a carbon source for fermentation that yields high-value secondary metabolites with potential antimicrobial and antifungal activity. The result is a circular bioprocessing model that minimizes waste while producing bioactive compounds with applications in healthcare, agriculture, and antimicrobial material coatings.
Technical specifications
Key features:
- A microbial collection of 150 bacterial strains sourced from plastic-contaminated environments, screened for biopolymer degradation capability
- Ten promising Streptomyces and Bacillus strains selected based on agar-based substrate utilization assays
- Top five strains identified through soil burial degradation testing on PHB, PLA, and thermoplastic starch
- Genomic evidence of enzymes capable of degrading petroleum-derived polymers, expanding the range of treatable plastic waste
- Fermentation of biopolymer degradation byproducts to produce secondary metabolites with potential antimicrobial and antifungal bioactivity
- Ongoing characterization of bioactive metabolites and optimization of culture conditions to maximize yield
- Plans to scale up depolymerization fermentation and evaluate incorporation of derived antimicrobials into polymeric materials
Technology readiness level
The technology is currently at an early-to-mid stage of development. Laboratory validation has confirmed that selected bacterial strains can utilize biopolymers as their primary carbon and energy source, and soil burial degradation studies have identified the most effective performers. Current work focuses on analyzing fermentation leftovers for valuable secondary products and screening these metabolites for antimicrobial and antifungal activity against diverse bacterial and fungal strains. Future validation will include biological activity testing, metabolite characterization, culture condition optimization, fermentation scale-up, and evaluation of antimicrobial incorporation into polymeric materials.
About Technological University of Shannon
Technological University of the Shannon (TUS) is a multi‑campus technological university spanning seven sites across Ireland’s Midlands and Midwest, combining applied research with strong industry engagement. Enterprise Ireland Technology Gateways on TUS campuses provide industry‑accessible labs, testbeds and prototyping with rapid routes to collaboration. A network of campus‑based enterprise and innovation centres offers incubation and co‑located collaboration space for startups and corporate R&D, while work placements are embedded across programmes and coordinated centrally for employers. Research is supported by national agencies such as Science Foundation Ireland, Enterprise Ireland and the Irish Research Council, alongside European funding programmes. A dedicated Knowledge Transfer and Commercialisation Office streamlines IP, licensing and spin‑out support.
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