Project Description

Abstract


Plastic pollution has become a global crisis, with Thailand ranking sixth in mismanaged plastic waste and contributing over 1 million tonnes to the oceans annually (Jambeck et al. 2025). Microplastics are now detected across ecosystems in Thailand—from 80% of sampled marine organisms to tap water, air, and agricultural soils—threatening biodiversity, food security, and human health (Chanpiwat, 2021). Among plastics, polyethylene terephthalate (PET) is the most prevalent, accounting for 37% of mismanaged waste. The discovery of PETase from Ideonella sakaiensis in 2016 revealed a promising route for enzymatic PET degradation, yet microbial expression limits large-scale application.

Here, the Thailand-RIS iGEM 2025 team presents the first demonstration of PETase expression in a multicellular system: plants. While stable transformation remains ongoing, we successfully achieved transient expression of PETase fused with an alpha-amylase 3S signal peptide into Nicotiana benthamiana, enabling extracellular secretion of the enzyme. By establishing proof of concept for plant-based PETase expression, we hope to pave the way for scalable, sustainable bioremediation strategies that integrate prevention and active degradation of plastic pollution.

The Challenge and the Problem


“Plastic is great until we no longer need it,” said Chalat Lertrattanachaikij, the 2025 Thailand-RIS Team Captain. This quote highlights two key points. Firstly, plastics are essential to our lives. In fact, plastic plays a pronounced role in improving our quality of life and convenience. Secondly, plastics are hugely problematic toward the end of their life cycle. The durability of plastics serves a dual purpose, enhancing their utility while simultaneously complicating waste management.

fig.1

Currently, various efforts have been made to combat plastic pollution. This includes three main types of effort: a reduction effort, a replacement effort, and a recycling effort.

  • Reduction efforts ranging from advocacy campaigns to boycotts aim to decrease single-use plastic usage in key sectors. For example, major supermarket chains in Thailand like Tops, Lotus, Big C, and 7-Eleven have all stopped giving away single-use plastic bags (Nation, 2019). Government and other nonprofit organizations also contribute to reduction efforts via physical and digital advertisements as well as roadmaps.
  • In terms of replacement efforts, greener alternatives such as bioplastics are also on the rise. One notable example is the rise in bioplastic straws, which are projected to nearly double from USD 12.3 billion in 2025 to USD 25.1 billion by 2035 (Sharma, 2025).
  • Lastly, recycling efforts are also trending globally. In fact, over the last two decades, plastic recycling has increased from less than 5% to over 10% in some countries (Samborska, 2024). A notable example is the increase in widespread use of Reverse Vending Machines (RVM), which supply money for plastic bottle deposits, thereby incentivizing recycling.

Unfortunately, the efforts mentioned earlier have two significant drawbacks. Firstly, all these efforts lead to a reduction in plastics usage; however, previously produced plastics will still exist for hundreds of years to come. In fact, those plastics may eventually break down into microplastics, which can harm life on Earth in previously unconsidered ways. Secondly, these efforts are also, to a very great extent, ineffective. This point can be expanded in the following way:

  1. Firstly, our need for plastic limits our ability to reduce and replace it. In a way, plastic has become so ingrained in our daily lives that its complete removal is impossible. In Thailand, specifically, the lack of filtered water and convenience resulted in 80% of Thai households using one to four single-use plastic bottles per day, and the remaining 20% used more (Khoironi et al., 2019). Government agencies can directly contribute to the reduction of plastic by passing regulations. Nonetheless, most countries, including Thailand, have only been creating roadmaps but not regulation (Simachaya, 2025). In fact, the recent UN-led talks to finalize a binding global plastics treaty to address plastic pollution adjourned in Geneva in August 2025 without an agreement (BBC News, 2025).
  2. In terms of green alternatives, bioplastics have three main issues: high cost, lack of durability, and potential sustainability concerns. In one of our interviews with plastic producers in Thailand, they mentioned the economic setback of switching production to bioplastics as increasing production costs by up to 80%. Without regulation, the financial burden of bioplastics means that industry is very unlikely to change in the near future. In terms of durability, Dr. Wijarn Simachaya, the president of the Thailand Environmental Institute, whom we interviewed, simply said that “bioplastics are just not as good as conventional plastics [for various purposes].” Lastly, the majority of bioplastics are not biodegradable or can only be degraded under extremely specific conditions (Ghasemlou et al., 2024). This last point is extremely potent, as countries like Thailand lack recycling facilities for regular plastic, not to mention ones with specific heat and humidity controls to degrade biodegradable plastics.
  3. Lastly, the recycling efforts are limited by the fact that recycling processes are not perfect. Even if plastic products are to be reprocessed, they would lack the structural integrity of freshly made ones, as informed by our interview with Dr Wichuda Daud. Moreover, recycled products also have a limited lifespan and eventually need a place to expire. Rather than mitigating the problem, recycling may only prolong the journey plastic takes to reach a landfill or end up in the environment.

Our broader inability to effectively address plastic pollution leads to various consequential effects, primarily due to the durable quality of plastics. Instead of being broken down into non-harmful material, plastic instead breaks down into smaller plastics called microplastics. These microplastic fragments pose a significant threat to the environment, with the food chain in particular being an area of significant concern. Microplastics typically enter the food chain through the water. From there, plants consume water through the roots and translocate it throughout the plant, which is consumed by other organisms and as such, it travels through the trophic levels (Tang , 2023). The prevalence of microplastics in aquatic environments, especially the ocean, has also led to their introduction into the food chain via the fish that consume them. Not to mention, various organisms also consume such contaminated water.

Accumulation of microplastics from contaminated water and subsequent food sources causes harm to people through gastrointestinal obstruction, asthma, allergy, and chronic pneumonia, to name a few. Furthermore, recent research has reported the presence of high accumulations of micro- and nano-plastic particles in deceased brains with documented dementia diagnoses (Nihart, 2025), hinting at a potential link between dementia and the amount of microplastics in the body. More information about plastic can be found on the Plastics and Microplastics Page.

Project Inspiration and Solution


Given the extent of plastic's potential harm to all forms of life, a catastrophe is inevitable without change. Unfortunately, the solutions currently implemented—reduction efforts, replacement efforts, and recycling efforts—have proven ineffective, making the future seem bleak. This is where our team, Thailand-RIS, comes into play.

The goal of the Thailand-RIS team is to find alternative solutions to combat plastic pollution. While the majority of plastic pollution solutions focus on reduction, replacement, and recycling, a crucial solution is often overlooked—finding ways to reduce the harmful effects of plastic waste, or decomposing plastics.

Plastic pollution has become so widespread that many of us subconsciously treat it as part of daily life rather than an urgent environmental crisis. This realization motivated our team to pursue an efficient, scalable solution. In 2016, Shosuke Yoshida and colleagues at the Kyoto Institute of Technology discovered the bacterium Ideonella sakaiensis and its enzyme PETase, capable of breaking down polyethylene terephthalate (PET), the common plastic used in bottles, food containers, and even clothing. PET accounts for up to 37% of mismanaged plastic waste in Thailand (IUCN-EA-QUANTIS, 2020), and its particles are highly concentrated in water sources, which rapidly spread across all kingdoms of life. Therefore, PETase represents a promising biological tool, of which details will be discussed in the PETase Page. However, the discovery of PETase in bacterial systems presents challenges related to efficiency, safety, and sustainability.

To overcome these limitations, our project focuses on expressing the PETase gene in plants, a complex organism that would allow efficient, sustainable, and safe real-world applications. Please refer to the engineering page for how this will be done.

Aim, Vision, Outlook


The immediate aim is to show, clearly and convincingly, that plants can produce and secrete PETase into the extracellular space, where it can actually meet and act on microplastics—starting with transient expression in Nicotiana benthamiana and building toward stable lines once performance and safety are in hand. Please refer to the Engineering Page and Experiment Page for more information.

The long-term vision is a contained, modular biofilter that uses plant beds—akin to constructed wetlands—to passively capture microplastics and degrade them in situ, operating on sunlight, nutrients, and routine stewardship rather than external power or harsh chemistries. This system is designed to fit within Thai and international biosafety norms by avoiding open release, combining genetic safeguards with physical containment, and focusing on hosts and promoters that localize enzyme production where particles actually accumulate (for example, root-biased expression when moving to aquatic or riparian plants). Beyond remediation, the platform also keeps a door open to circularity: tracking PET hydrolysis products and, where feasible with licensed partners, repolymerizing purified TPA and EG into new PET—so the same system can either mineralize safely or route clean feedstocks back into production. This vision is modeled within our entrepreneurship page.

In the near term, the focus is on three steps:1) prove secretion in plants (now demonstrated in N. benthamiana), 2) make the system functional, efficient, and safe through activity assays, secretion tuning, promoter targeting, variant testing, byproduct accounting, and kill‑switch validation, and 3) bridge to contained pilots that test real water with engineered hosts in bench‑scale beds, while adhering to Thailand’s GMO rules and iGEM safety limits for high‑school teams. As the work progresses, host selection can shift toward high‑transpiration aquatic species such as water hyacinth for better real‑world interfacing, provided biosafety and compliance are preserved through enclosure and clear end‑of‑life protocols. Throughout, stakeholder input—on root‑localized expression, end‑of‑life risks, and Thailand’s fragmented recycling logistics—will shape technical choices and deployment models, ensuring the biofilter advances as both a scientifically credible tool and a service that can be adopted where it’s most needed.

Please refer to the Vision and Outlook Page for more information.

Integrated Human Practices


Integrated human practices are the key to understanding the importance and impact of our project. Through interactions with various stakeholders ranging from microplastics experts to directors of environmental organizations, the Thailand-RIS team has developed a comprehensive understanding of three key areas related to the plastics situation in Thailand.

  1. The extent of the plastic problem in Thailand: People typically envision large piles of bottles and trash in clear, open areas and oceans, ready for easy collection. But the truth is that the global and Thai plastic problem is more hidden and widespread than they realize. Our study suggests that a different approach to addressing microplastics at the molecular level is needed.
  2. The importance of plastic as a material: Despite the stigma against plastic, the Thailand-RIS team was able to see the overshadowed benefits of the material that play a much more important role in the Thai economy. The team suggests that despite its flaws, plastic is an indispensable material for the world, especially Thailand.
  3. The effectiveness of Thailand’s waste management system: Current waste management systems in Thailand are largely disorganized, with multiple organizations and local authorities competing to profit from government quotas rather than effective waste processing. At the same time, NGOs and other groups have successfully tested plastic management frameworks that combine both formal and informal sectors. With this data in mind, it could be argued that a similar unofficial framework involving natural plant processes and government policies could also work in dealing with Thailand’s plastic waste management system.

All of these insights from our outreach towards multiple stakeholders informed our engineering design choices and shaped our vision and outlook on the project. Our conversations with the National Science and Technology Development Agency (NSTDA) influenced key decisions such as narrowing our focus to the bioremediation of aquatic environments and water-related infrastructures. Subsequent interviews with plastics experts and plastic producers directed our vision and outlook, in conjunction with entrepreneurship, towards the development of a biofilter capable of degrading PET plastic.

More detailed findings can be found on the Human Practices Page

Special Award Remarks

Modelling


Our key modeling work establishes how PETase from I. sakaienesis interacts with PET oligomers while translating those insights into design choices for construct composition and validation; specifically, the IsPETase-Amy3S Coding Part Codon Optimised for Nicotiana benthamiana (BBa_252Q5ZWV). Beyond that, additional information models are created to establish our vision. More information about modeling can be found in the Docking Simulation, Vision and Outlook, and Entrepreneurship Pages.

Sustainability


As much as our project is an embodiment of sustainability and a stride towards responsible plastic waste management, our team took extra steps to ensure that our conduct and practices during our meetings and at the lab aligned with the United Nations’ Sustainable Development Goals. Our outreach efforts, geared toward raising awareness about the extent of microplastic pollution and reducing plastic usage in our school community, demonstrate our dedication to creating a sustainable mindset and environment in Thailand and beyond.

See the Sustainability Page for more information.

Education


Team Thailand-RIS’ education program objective is to promote learning and dialogue between our team and various stakeholders and communities. We aim to promote and increase access to synthetic biology across a range of demographics. This was made possible through school based events, like the Synbio Zoo workshop in a Thai government school and section based workshops at RIS, as well as community outreach activities such as exhibitions and fairs. Moreover, we also aim to enhance the public understanding of microplastics and their detrimental effects on human beings and the environment. These efforts included the HS microplastics workshop, an educational meeting with RIS’s Administrative Council to reduce plastic on campus and a dedicated page on our team’s wiki on plastic. Our education campaign was sustained throughout the Feb-Oct iGEM season, rather than concentrated one-time events.

Through collaborations and integrating our workshops into schools' curricula, this helps ensure that the knowledge and resources we share will not disappear, but instead will continue to be used and developed even after the end of iGEM’s season. We aim to make education more accessible, inclusive, and engaging, with a long-term impact, enabling various demographics to learn about and witness the positive change that synthetic biology can bring.

References

  1. BBC News. (2025, August 15). No agreement reached in UN plastic pollution talks [Video]. YouTube. https://www.youtube.com/watch?v=wPWSKuTUdgM
  2. Chanpiwat, P., & Damrongsiri, S. (2021). Abundance and characteristics of microplastics in freshwater and treated tap water in Bangkok, Thailand. Environmental Monitoring and Assessment, 193(5). https://doi.org/10.1007/s10661-021-09012-2
  3. Ghasemlou, M., Barrow, C. J., & Adhikari, B. (2024). The future of bioplastics in food packaging: An industrial perspective. Food Packaging and Shelf Life, 43, 101279–101279. https://doi.org/10.1016/j.fpsl.2024.101279
  4. Hasan, M. M., & Tarannum, M. N. (2024). Adverse impacts of microplastics on soil physicochemical properties and crop health in agricultural systems. Journal of Hazardous Materials Advances, 17, 100528. https://doi.org/10.1016/j.hazadv.2024.100528
  5. Khoironi, A., Anggoro, S., & Sudarno, S. (2019). Community behaviour and single-use plastic bottle consumption. IOP Conference Series: Earth and Environmental Science, 293(1), 012002. https://doi.org/10.1088/1755-1315/293/1/012002
  6. Nihart, A. J., Garcia, M. A., El Hayek, E., Liu, R., Olewine, M., Kingston, J. D., Castillo, E. F., Gullapalli, R. R., Howard, T., Bleske, B., Scott, J., Gonzalez-Estrella, J., Gross, J. M., Spilde, M., Adolphi, N. L., Gallego, D. F., Jarrell, H. S., Dvorscak, G., Zuluaga-Ruiz, M. E., & West, A. B. (2025). Bioaccumulation of microplastics in decedent human brains. Nature Medicine, 31(3). https://doi.org/10.1038/s41591-024-03453-1
  7. Samborska, V., & Roser, M. (2024). Plastic recycling rates are increasing, but slowly, in many regions. Our World in Data. https://ourworldindata.org/data-insights/plastic-recycling-rates-are-increasing-but-slowly-in-many-regions
  8. Sharma, R. (2025). Bioplastic Straw Market Research Report 2033. In S. Bhat (Ed.), Data Intelo. https://dataintelo.com/report/bioplastic-straw-market
  9. Tang, K. H. D. (2022). Phytoremediation of microplastics: A perspective on its practicality. Industrial and Domestic Waste Management, 3(2), 90–102. https://doi.org/10.53623/idwm.v3i2.291
  10. The Nation. (2019, November 22). Some 7-11 branches to implement “no plastic bags” policy from Nov 25. Nation Thailand. https://www.nationthailand.com/in-focus/30378637
  11. United Nations Environment Programme (UNEP). (2020). National guidance for plastic pollution hotspotting and shaping action: Final report for Thailand. Supported by the Swedish International Development Cooperation Agency (Sida). https://plastichotspotting.lifecycleinitiative.org/wp-content/uploads/2020/11/Thailand_Final-report_2020_11_03_SMALL.pdf