BUCT - iGEM 2025

Overview

Polyester plastics such as PET, PBAT, and PLA are difficult to degrade, especially in marine environments. To address this, POLYGONE engineered a suite of genetic parts enabling polyester hydrolysis, surface binding, and integrated degradation. These parts include engineered hydrolases, anchoring modules, and display systems, forming a comprehensive toolkit for the biodegradation polyester microplastics. All parts are deposited in the iGEM Registry for reuse and further optimization by future teams.

Basic Parts

Among the basic parts designed this year by ourselves, the BBa_25OKR7XM is our favorite one. Basing on computer-aided mining and AI-driven design, the basic part can efficiently degrade polyester plastics (such as PET, PBAT, and PLA) in marine environments. Further development is expected to provide an effective solution for addressing marine polyester plastic pollution at its source. We have also designed numerous other building blocks to build upon our projects, developing solutions for the full lifecycle of marine polyester plastic waste.

Type	Part number	Name	Length	Brief introduction
Coding	BBa_25OKR7XM	polygonase	786	polygonase is a rationally engineered variant of a highly efficient marine-derived polyester hydrolase from Glaciecola sp. MH2013, suitable for the development of sustainable, biodegradable polyester materials and enzyme-integrated plastics processing applications.
Coding	BBa_2561HNDJ	mfp-3	138	Adhesive protein.
Coding	BBa_25X8RFVL	INPNC	969	INPNC refers to a truncated variant of the Ice Nucleation Protein (INP) from Pseudomonas syringae, are widely used as an anchoring motif for bacterial surface display of recombinant proteins.
Coding	BBa_254LC28K	SpyCatcher	276	Capture and covalently bind the target protein labeled with SpyTag on the surface of the bacteria.
Coding	BBa_25UOIGII	SpyTag	39	As a short peptide tag that fuses with the target protein.
Coding	BBa_K5487002	Lpp-OmpA	438	It acts as a signal peptide to direct the fusion protein to the outer membrane of E. coli and target heterologous proteins onto the cell surface.
Coding	BBa_K2136016	mcherry	708	Red fluorescent protein.
Coding	BBa_K3007036	sfGFP	714	Green fluorescent protein.
promoter	BBa_255YROB7	Plpp1.2	49	It is a promoter derived from E. coli, and its main function is to drive the expression of the downstream target gene in bacteria.
promoter	BBa_I719005	T7 promoter	19	The T7 promoter, from bacteriophage T7, is specifically recognized by T7 RNA polymerase. It drives high-level downstream gene expression in E. coli and is key for recombinant protein production.
Terminator	BBa_K3740023	T1 terminator	54	The T1 terminator, from E. coli's rrnB operon, strongly terminates bacterial transcription.
Terminator	BBa_K731721	T7 terminator	48	The T7 terminator, from bacteriophage T7, efficiently terminates transcription by T7 RNA polymerase in bacterial systems.

Composite Parts

Composite parts in our project integrate multiple functional domains to construct efficient biological modules for polyester adhesion, degradation, and detection. Each composite part was designed based on modular synthetic biology principles, ensuring compatibility, standardized assembly, and expandability for future teams. These composite constructs represent the core implementation of our end-of-life strategy - microplastic degradation.

Type	Part number	Name
Translational Unit	BBa_253G9PEP	pETlac-Plpp1.2-INPNC-mfp-3
Translational Unit	BBa_25Z2E1U0	pETlac-Plpp1.2-INPNC-mcherry
Translational Unit	BBa_25AS25TW	pET28a-Lpp-OmpA-SpyCatcher
Translational Unit	BBa_256OD3D8	pET28a(+)-sfGFP-SpyTaq
Translational Unit	BBa_25GH8BJU	pET28a-polygonase-SpyTaq

Part Collections

To achieve an integrated biological solution for polyester biodegradation and microplastic remediation, POLYGONE developed a Surface Co-Display System Collection that brings together all functional components required for adhesion, enzymatic catalysis, and visualization. This collection provides a modular and reusable synthetic framework that allows engineered E. coli to attach to, degrade, and monitor polyester-based plastics such as PET, PBAT, and PLA in marine-like conditions.

System	Type	Part number	Name	Function
	Functional System	308ada94-2bbb-4e44-a03f-7984fbe52012	Monitoring platform	Whole-cell catalysis
Adhesion system	Coding	BBa_2561HNDJ	mfp-3	Adhesion protein
	Coding	BBa_25X8RFVL	INPNC	Outer membrane anchor
	Coding	BBa_K2136016	mcherry	Fluorescent reporter
	promoter	BBa_255YROB7	Ppp1.2	Constitutive promoter
	Terminator	BBa_K3740023	T1 terminator	Transcription terminator
	Translational Unit	BBa_253G9PEP	pETlac-Ppp1.2-INPNC-mfp-3	Adhesion module
	Translational Unit	BBa_25Z2E1U0	pETlac-Ppp1.2-INPNC-mcherry	Fluorescent validation
Degradation system	Coding	BBa_25OKR7XM	polygonase	Polyester hydrolase (catalytic enzyme)
	Coding	BBa_254LC28K	SpyCatcher	Covalent binding domain
	Coding	BBa_25UOIGII	SpyTag	Covalent binding peptide
	Coding	BBa_K5487002	Lpp-OmpA	Surface display scaffold
	Coding	BBa_K3007036	sfGFP	Fluorescent reporter
	promoter	BBa_I719005	T7 promoter	Inducible promoter
	Terminator	BBa_K731721	T7 terminator	Transcription terminator
	Translational Unit	BBa_25AS25TW	pET28a-Lpp-OmpA-SpyCatcher	Display anchor
	Translational Unit	BBa_256OD3D8	pET28a(+)-sfGFP-SpyTag	Interaction verification
	Translational Unit	BBa_25GH8BJU	pET28a-polygonase-SpyTag	Catalytic enzyme

Contents

Overview

Basic Parts

Composite Parts

Part Collections