JOURNAL OF HAZARDOUS MATERIALS
·
2024
·
IF 12.2
Si-Qi Chen,Qing-Song Huang,Yang Li,Jing Wu,Sheng Chen,Zheng-Fei Yan
Polyethylene terephthalate (PET) is one of the most widely used plastics, but its fragmentation into microplastics poses significant environmental challenges. The recycling of PET microplastics is hindered by their low solubility and widespread dispersion in the environment, making microbial in-situ degradation a promising solution. However, existing PET-degrading strains exhibited the limited effectiveness, primarily due to the diffusion of secreted hydrolases away from the PET surface. In this study, Stenotrophomonas pavanii JWG-G1 was engineered to achieve the targeted aggregation of PET hydrolase PETase on the cell surface by fusing it with an endogenous anchor protein. This approach aims to maximise the local concentration of PETase around PET, thereby increasing the overall rate of PET degradation. The PETase surface-aggregated system, S. pavanii /PaL-PETase, demonstrated the highest degradation efficiency, achieving 63.3 % degradation of low-crystallinity PET (lcPET) and 27.3 % degradation of high-crystallinity PET bottles (hcPET) at 30 °C. This represents the highest degradation rate reported for a displayed whole-cell system at ambient temperature. Furthermore, this system exhibited broad-spectrum degradation activity against various polyesters. These findings suggest that this system offers a promising, eco-friendly solution to PET and other polyester pollution, with potential implications for environmental bioremediation strategies.
研究领域:
环境科学
·
微生物学
·
生物技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2021
·
IF 7.963
Qing-Song Huang,Zheng-Fei Yan,Xiao-Qian Chen,Yan-Yi Du,Juan Li,Zhan-Zhi Liu,Wei Xia,Sheng Chen,Jing Wu
Polyethylene terephthalate (PET) is a general plastic that produces a significant amount of waste due to its non-biodagradable properties. We obtained four bacteria ( Stenotrophomonas pavanii JWG-G1, Comamonas thiooxydans CG-1, Comamonas koreensis CG-2 and Fulvimonas soli GM-1) that utilize PET as a sole carbon source through a novel stepwise screening and verification strategy. PET films pretreated with S. pavanii JWG-G1 exhibited weight loss of 91.4% following subsequent degradation by Thermobifida fusca cutinase (TfC). S. pavanii JWG-G1 was able to colonize the PET surface and maintain high cell viability (over 50%) in biofilm, accelerating PET degradation. Compared with PET films with no pretreatment, pretreatment with S. pavanii JWG-G1 caused the PET surface to be significantly rougher with greater hydrophilicity (contact angle of 86.3 ± 2° vs. 96.6 ± 2°), providing better opportunities for TfC to contact and act on PET. Our study indicates that S. pavanii JWG-G1 could be used as a novel pretreatment for efficiently accelerating PET biodegradation by TfC.
研究领域:
环境科学
·
微生物学
·
生物技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2024
·
IF 8.2
Qing-Song Huang,Si-Qi Chen,Xiao-Min Zhao,Li-Jun Song,Yu-Ming Deng,Ke-Wei Xu,Zheng-Fei Yan,Jing Wu
Polyethylene terephthalate (PET) microplastics pose significant environmental and human health risks due to their resistance to degradation and accumulation in ecosystems. In this study, we engineered Stenotrophomonas pavanii JWG-G1, a robust biofilm-forming bacterium, to overexpress the PET hydrolase (DuraPETase) for PET microplastics degradation at ambient temperature. Nine endogenous PET hydrolases were identified through genome sequencing of S. pavanii , and were successfully expressed in Escherichia coli BL21(DE3). Among them, hydrolase Est_B achieved 100% degradation of bis(2-hydroxyethyl) terephthalate (BHET) at an initial concentration of 0.23 mg/mL at 30 °C within 4 h, identifying it as a novel BHETase. However, the PET degradation performance of all endogenous PET hydrolases was inferior to that of DuraPETase. The engineered strain overexpressing DuraPETase demonstrated a significant enhancement in PET degradation, achieving a 38.04 μM total product release of high-crystallinity PET microplastics after 30 days at 30 °C. The degradation extent was greater than that of low biofilm-forming engineered strains, attributing to the aggregation of DuraPETase on the PET surface in the presence of biofilm. Additionally, this engineered strain also maintained PET degradation activity across various water environments and demonstrated effectiveness in degrading other polyester plastics. This is the first report demonstrating that an engineered strain of Stenotrophomonas species is capable of simultaneously secreting exogenous hydrolase and degrading polyester microplastics, representing a novel approach in the development of engineered bacteria with potential applications in bioreactor systems and environmental remediation.
研究领域:
环境科学
·
微生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2026
·
IF 8.7
Cui-Can Lu,Qing-Song Huang,Wen-Jing Zheng,Xiao-Min Zhao,Tian-Tian Wang,Yan Huang,Jing Wu,Zheng-Fei Yan
BHETase_B exhibited higher activity toward BHET than PET and MHET. • Half-lives of engineered BHETase_B (>5.0 h) was greater than WT at 50 °C. • Mutant Q7I/A106P achieves complete degradation of BHET within 2 h at 50 °C. • Mutant Q7I/A106P plus TurboPETase can synergistically degrade PET. Polyethylene terephthalate (PET) plastic waste poses significant environmental challenges. Enzymatic degradation of PET offers a sustainable recycling route, but intermediate products such as bis (2-hydroxyethyl) terephthalate (BHET) and mono (2-hydroxyethyl) terephthalate (MHET) can inhibit further hydrolysis. A bis (2-hydroxyethyl) terephthalate hydrolase (BHETase_B) from Stenotrophomonas pavanii exhibited hydrolytic activity toward both BHET and MHET, but its poor thermal stability limited industrial application. In this study, a combination of rational design and directed evolution strategies were employed to generate BHETase_B mutants, all of which exhibited significantly improved thermal stability with half-lives greater than 5.0 h at 50 °C, compared to the wild type (<1.5 h). Notably, mutant Q7I/A106P demonstrated a 7.6 °C increase in melting temperature (Tm = 52.5 °C for the wild type) and achieved complete degradation of BHET within 2 h at 50 °C. Mutant Q7I/A106P alone showed limited activity toward solid PET, but significantly enhanced product release when combined with PET hydrolases, especially TurboPETase, releasing 206.1 μM of products, a 1.4-fold increase compared with TurboPETase alone. These findings highlighted the potential of the engineered BHETase_B mutant as a downstream auxiliary enzyme for improving cascade PET degradation. Download: Download high-res image (155KB) Download: Download full-size image
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）