CONTRIBUCTION

Contribution

New Basic Parts

In this project, we designed and submitted the coding sequences of TurboPETase and β-CGTase as new BioBrick parts to the iGEM Registry.
Polyethylene terephthalate (PET) and starch derivatives are widely used polymeric materials, and their efficient degradation and reutilization remain major challenges in environmental and industrial applications. Previous studies have demonstrated that PETase is one of the most promising enzymes for PET degradation [1]. In particular, the engineered variant TurboPETase exhibits improved thermal stability and catalytic efficiency. On the other hand, β -CGTase catalyzes intramolecular transglycosylation reactions of linear and branched starch molecules, enabling the synthesis of cyclodextrins and novel carbohydrate-based materials [2].

We constructed expression plasmids carrying these sequences that can be efficiently expressed in E. coli BL21, and deposited both the parts and plasmid information in the iGEM Registry.

wiki-parts

Future iGEM teams working on plastic degradation, carbohydrate modification, or functional material synthesis can directly reuse these components without the need for sequence design and optimization. This will not only save considerable time and effort but also expand the toolkit available for interdisciplinary research in areas such as environmental biotechnology, biomaterials, and green chemistry.

Establishing a New Cyclodextrin Measurement Method

The detection of cyclodextrin production is commonly based on colorimetric methods, with phenolphthalein being the most widely used indicator. Although simple to operate, this approach has limited sensitivity and can only establish stable standard curves at relatively high concentrations. Moreover, the phenolphthalein method is highly susceptible to pH fluctuations and interference from impurities in the system, which often leads to deviations in practical applications and hampers accurate quantification of cyclodextrins at low concentrations.

To address this issue, we established a detection method based on the fluorescent probe ANS. ANS can specifically bind to the hydrophobic cavity of cyclodextrins, resulting in a significant enhancement of fluorescence intensity. By detecting this change with a fluorescence spectrometer, we developed a cyclodextrin standard curve with higher sensitivity and stronger specificity. Compared with the phenolphthalein method, this approach enables accurate detection of cyclodextrins at lower concentration ranges, with a broader linear range and improved resistance to interference.

wiki-measurement

Reaching Out to More Groups (Inclusivity)

We innovatively focused on two often overlooked groups: ethnic groups in China and Non-STEM students. Our research identified the specific barriers they face in joining scientific activities. We then designed actions to help overcome these obstacles. This work had a positive impact and also serves as a practical case study. We hope it provides new ideas and actionable methods for the wider iGEM community.

see more details on: Inclusivity Page

Building a New Method for Analysis (Inclusivity)

In our Inclusivity part, we used the “WHWR” framework (Why, How, What, Reflection). This framework helped us support different groups in a structured way. It guided us through a clear process: first understanding groups’ problem, then taking action, finally thinking about what we learned and what we can improve. This helped us better understand each group's real needs and carry out effective activities.

Especially, in the "Reflection" step, we compiled our findings into a guide. This guide can help other iGEM teams plan their own inclusiveness activities. We hope this encourages all iGEM teams to share ideas and work together. By doing so, we can better address the barriers different groups face and truly enable more people to participate in scientific activities on an equal basis.

see more details on: Inclusivity Page

Establishing a Low-Cost Phosphorescence Detection Method

The characterization of phosphorescent materials is typically dependent on fluorescence spectrometers or specialized imaging instruments. However, such equipment is costly and often inaccessible to most student laboratories. Moreover, phosphorescence intensity and emission color are difficult to evaluate accurately by eye, and repeated submission of samples for professional analysis during experimental optimization is time-consuming and expensive.

To address this challenge, we developed a workflow that employs common imaging devices (e.g., smartphones or digital cameras) to capture phosphorescence signals, followed by quantitative analysis using ImageJ. This method relies on grayscale and brightness extraction from images to evaluate relative phosphorescence intensity, and we established a standardized experimental protocol that can be readily implemented. As ImageJ is open-source and user-friendly, the procedure requires only photographs taken in a dark environment, which can then be rapidly analyzed on a computer to provide immediate feedback for experimental optimization.

wiki-measurement

Experimental validation demonstrated that this method reliably distinguished relative intensity differences among samples, with trends consistent with spectrometer-based measurements. Repeated trials further confirmed its reproducibility and robustness.

Enzymatic Synthesis of Phosphorescent Materials

Phosphorescent materials have attracted increasing attention due to their potential applications in bioimaging, sensing, and advanced optoelectronics. However, conventional synthetic methods typically rely on high-temperature pyrolysis or harsh chemical conditions, which hinder their adoption in green chemistry and biological contexts.

In this project, we successfully developed an enzyme-catalyzed route for the synthesis of PPA-CD, a novel room-temperature phosphorescent material. By employing a dual-enzyme system consisting of TurboPETase and β-CGTase, we achieved the controlled transformation of polymeric substrates into functional phosphorescent products. The synthesis was carried out under mild aqueous conditions, significantly reducing the energy input and chemical hazards compared with traditional methods.

wiki-notebook

Characterization by UV irradiation and photoluminescence spectroscopy confirmed that the resulting PPA-CD displayed a stable and distinct phosphorescent emission at room temperature. This work represents, to the best of our knowledge, the first demonstration of enzymatic synthesis of a phosphorescent material, providing a sustainable strategy for functional material production and opening possibilities for the enzymatic synthesis of other carbon-based luminescent systems.

Waste-to-Value Strategy for Phosphorescent Materials

The accumulation of plastic residues and food waste poses severe environmental challenges. Conventional recycling methods often fail to generate high-value products, thereby limiting incentives for waste valorization.

We proposed and implemented a waste-to-value strategy by using enzymatic degradation products of polyethylene terephthalate (PET) and starch-based kitchen waste as precursors for phosphorescent material synthesis. TurboPETase efficiently degraded PET into terephthalic acid (TPA), while β-CGTase converted starch into β-cyclodextrin (β-CD). These intermediates were subsequently used as building blocks for the synthesis of phosphorescent PPA-CD.

wiki-engineering

This approach not only diverts waste streams away from landfills but also transforms them into functional luminescent materials with potential applications in sensing and sustainable materials research. Our work demonstrates that environmental remediation and high-value material synthesis can be achieved simultaneously, providing a promising paradigm for green biotechnology-based upcycling of waste resources.

One-Pot Enzymatic Synthesis of Phosphorescent Materials

Traditional chemical syntheses of luminescent materials often involve multiple steps, requiring separate reactions, purification, and post-treatment, which greatly reduce efficiency.

We designed a one-pot enzymatic synthesis system, integrating the actions of TurboPETase and β -CGTase in a single reaction vessel. This system allowed the direct conversion of PET and starch derivatives into PPA-CD, without the need for intermediate isolation.

wiki-engineering

Optimization of reaction conditions, including temperature, pH, and substrate concentration, enabled the efficient formation of phosphorescent products under aqueous and mild conditions. The one-pot process significantly reduced labor, time, and resource consumption, highlighting the potential of enzyme-based cascade reactions as an effective platform for the sustainable synthesis of advanced materials.