Recently, the team led by Prof. Li Yuezhong from State Key Laboratory of Microbial Technology of Shandong University published a research article entitled "A strategy for in situ sustainable PET degradation in soil by genetically engineered bacteria constructed from indigenous strains" in Journal of Hazardous Materials. This study proposes a novel strategy for plastic pollution remediation through the functional enhancement of indigenous soil microbiota, and provides a basis for developing a generalizable paradigm for in situ bioremediation of environmental contamination. The paper features M.S. candidate Lai Yajun and Dr. Wan Tianyu as co-first authors, Assoc. Prof. Zhuo Li and Prof. Li Yuezhong as co-corresponding authors, and State Key Laboratory of Microbial Technology of Shandong University as the sole author affiliation.

Plastic pollution is a significant global concern, with polyethylene terephthalate (PET) being a major contributor. Due to its resistance to degradation, PET persists in the environment and causes severe pollution. The research team isolated indigenous bacteria from the target soil. Based on electroporation and transposon systems, the optimized PET degradation enzyme FAST-PETase gene sequence was stably integrated into the genomes of six representative indigenous bacteria to construct genetically engineered bacteria (GEBs) capable of secreting PETase. Under laboratory conditions, these GEBs could effectively degrade PET films and generate small molecule products such as terephthalic acid (TPA).

More importantly, after being reintroduced into the soil, the GEBs could stably colonize for at least four months, with the FAST-PETase gene continuously expressed and maintaining degradation activity. Metagenomic analysis revealed that the introduction of GEBs had no significant impact on the species composition and functional diversity of the soil microbial community, with minimal ecological disturbance and stable ecosystem integration. This strategy utilizes indigenous bacteria as the chassis for engineering modification, effectively circumventing the ecological risks and colonization challenges associated with the introduction of exogenous microorganisms. It offers a novel approach for the eco-friendly remediation of PET-contaminated soil and also presents a versatile platform that could be extended to the in situ treatment of other environmental pollutants.

This work was financially supported by the National Key Research and Development Programs of China, the National Natural Science Foundation of China, Natural Science Foundation of Shandong Province, SKLMT Frontiers and Challenges Project, Young Talent Development Program of SKLMT, and funded by Shandong Postdoctoral Science Foundation.