俞汉青院士团队EST|工程化可编程电活性活体材料用于高效回收铀

政务   2024-12-24 08:41   湖北  

文章信息

第一作者:李凤和,梁子涵

通讯作者:汤强 教授,俞汉青 院士

通讯单位:中国科学技术大学环境科学与工程系

https://doi.org/10.1021/acs.est.4c07276

成果简介

图文摘要

近日,中国科学技术大学环境科学与工程系俞汉青院士团队在Environmental Science & Technology发表了题为“Engineering Programmable Electroactive Living Materials for Highly Efficient Uranium Capture and Accumulation”的研究论文(DOI: 10.1021/acs.est.4c07276)。该研究设计并构建了一种新型的可编程电活性活体材料(Electroactive Living Materials,ELMs),实现了铀的高效捕获与积累。通过合成生物学方法,将电活性微生物的可扩展性与多细胞系统的稳健性相结合,开发出能在环境中高效捕获和还原U(VI)的材料。研究表明,ELMs在微生物电化学测试中展现出优异的电活性,并在铀回收应用中表现出强大的铀捕获、还原和积累能力。

研究进展

1 全文速览

针对传统铀回收技术效率低、环境影响大的问题,本研究提出了一种新型的可编程电活性活体材料(ELMs),能够在环境中高效捕获和积累铀。研究选用Shewanella oneidensis作为底盘菌株,基因工程改造后在细菌表面展示铀结合蛋白,并优化Mtr电子传递途径,从而显著提升了铀的还原与捕获能力。同时,构建了生物膜促进回路,进一步增强了细胞间的相互作用,促进了电活性活体材料的高效自组装。通过微生物电解池和微生物燃料电池实验,验证了该材料在电活性方面的优越性能。在铀回收实验中,ELMs表现出强大的铀捕获、还原和积累能力,最大吸附容量达到808.42 μmol/g。该研究不仅为铀回收提供了一种环保的解决方案,还突显了电活性活体材料在可持续环境与能源技术中的广泛应用潜力。

2 引言

传统的铀回收技术面临效率低下、二次污染和能源转换效率低下等挑战。本研究以S. oneidensis为底盘菌株,利用合成生物学方法,通过将电活性微生物的可扩展性和可编程性与多细胞活材料系统的稳健性相结合,开发了一种新型电活性活体材料,可用于高效捕获和还原U(VI)。

3 图文导读

3.1 电活性活体材料设计

Figure 1. Schematic design of programmable ELMs. (A) Comparison of exoelectrogen in two different phases: the unicellular planktonic phase and as the programmable electroactive living materials (ELMs). (B) Scheme of reprogramming S. oneidensis at the individual cell level, highlighting modules for U(VI) capture, enhanced extracellular electron transfer (EET), cell interaction and biofilm promotion. (C) Roadmap for constructing, evaluating, and applying ELMs.
在ELMs的制备过程中,选择Shewanella oneidensis作为基础微生物底盘,利用基因工程技术在细菌表面展示特定的铀结合蛋白,并优化Mtr电子传递途径,以增强其对U(VI)的还原与捕获能力。同时,构建生物膜促进回路,强化细胞间相互作用并提高结构稳定性,从而实现电活性活体材料的高效自组装。

Figure 2. Engineering S. oneidensis cells as the foundational building block for ELMs. (A) Display of U(VI)-specific binding proteins SUP and MT on the bacterial surface. (B) FACS evaluation of the expression of SUP and MT through GFP-fusion protein constructs. (C) Enhanced uranium reduction by strains displaying SUP and MT. (D) Reconfiguration of the Mtr conduit pathway to enhance EET. (E) EET evaluation by microbial electrolysis cells (MECs). (F) Improved uranium reduction capacity by reconfigured Mtr conduit. (G) The uranium capture module of SUP and the reconfigured EET module were integrated into one single strain for efficient U(VI) capture and reduction. (H) Transmission electron microscopy (TEM) images showing particulate precipitates on the cell surface upon U(VI) exposure. (I) U(VI) conversion by the strain combined the uranium capture module with the reconfigured EET module.
通过基因工程改造S. oneidensis细胞,使其能够选择性捕获和积累铀。在细胞表面展示MT蛋白和SUP蛋白(高亲和力、强螯合铀能力),使得铀去除能力分别提高了1.69倍和2.80倍。同时,重构Mtr电子传递通路,提升了细胞的还原能力。微生物电解池实验显示,改造后的菌株的电子转移能力提高了6.03倍,U(VI)还原能力提高了1.83倍。 

Figure 3. Promoting cell-to-cell interaction and biofilm formation for engineering ELMs. (A) Schematic of gene expression circuits for biofilm-promoting factors, including BpfA (a cell surface-associated adhesin), AggABC (Type I secretion systems), and BolA (a global transcriptional regulator). (B) Promoted cell self-aggregation of the engineered strain observed at the single-cell level. (C) Increased biomass accumulation on the carbon felt surface due to spontaneous aggregation of the engineered bacterial cells. (D) Enhanced biofilm formation capability of engineered strains incorporating these factors step-by-step. (E) Confocal analysis of biofilm formation. Upper: control strain; lower: strain ELMBB (F) Quantitative analysis of biofilm volume and surface area.
通过引入包含bpfAaggABCbolA的生物膜促进回路,成功增强了细胞间的相互作用及生物膜形成能力。实验结果表明,经过改造的菌株能够形成密度更高、结构更紧凑的生物膜,其体积和表面积相较于对照组分别显著增加了11.34倍和7.51倍。

Figure 4. Assembly of ELMs. (A) Schematic of ELMs assembly, demonstrating the design of multifunctional materials with various properties. (B) Assessment of the self-assembly ability of ELMs. (C) Scanning electron microscopy (SEM) image revealing a dense bacterial film formed by the ELMBB strain on carbon felt. (D) Evaluation of assembly capability under stationary and shaking cultivation conditions with protein levels as indicator. (E) Assembly performance with protein levels as indicator under oligotrophic cultivation with different initial inoculated biomass. (F) Template-directed assembly of ELMs into various electroactive materials with specific structures.
增强细胞间的相互作用和生物膜形成能力显著提升了ELMs的自组装能力。在不同培养条件下,ELMBB菌株表现出卓越的自组装性能,能够自发地形成密集、紧凑的结构,并可通过模版定向形成具有特定几何形状和网状结构的ELMs,展现出强大的自组装能力。

3.2 电活性性能测试

Figure 5. Evaluation of the electrogenic activity of ELMs. (A) Current output of ELMs in MECs. (B) Voltage output of ELMs in a microbial fuel cell (MFC). (C) Polarization curves of ELMs (solid line) and power density (dashed line). Control: WT/pYYDT.
微生物电解池和微生物燃料电池实验表明,ELMs表现出更稳定的电流和电压输出,最大电流密度和输出电压分别提高了3.30倍和3.15倍。此外,ELMs的极化曲线显示其较低的内部电阻,提升了电荷转移效率,最大功率密度比对照组高出5.20倍。这些结果表明,ELMs具备优越的电活性性能。

3.3 U(VI)回收测试

Figure 6. Application of ELMs for uranium recovery. (A) Zeta potential measurements of ELMs before and after exposure to U(VI). (B) Fourier-transform infrared spectroscopy (FTIR) analysis identified characteristic vibration peaks, suggesting chemical changes in captured uranium. (C) X-ray photoelectron spectroscopy (XPS) confirmed the presence of reduced uranium species on the surface of the ELMs. (D) Quantitative analysis showed the efficiency of ELMs in capturing and accumulating uranium across various concentrations. (E) The maximum accumulation capacity positively correlated with initial concentration. (F) Schematic of using ELMs for uranium recovery in various applications. The experiment was conducted in triplicate, with error bars representing the standard deviation.
将ELMs用于铀(U(VI))的捕获、还原和积累。暴露于U(VI)后,ELMs的Zeta电位显著下降,表明其成功还原了U(VI),并通过化学变化积累了U(IV)(FTIR和XPS分析)。定量分析显示,ELMs在10–500 μM U(VI)浓度范围内快速积累铀,最大积累量为808.42 μmol/g。反应动力学符合伪一级反应模型,表明速率受限于表面活性位点。总体而言,ELMs展现了高效的U(VI)捕获、还原和积累能力,具有广泛的铀回收应用前景。

4 小结

本研究报道了一种新型可编程电活性活体材料(ELMs),并成功应用于铀的高效捕获、还原与积累。通过基因工程强化S. oneidensis的铀结合能力和胞外电子传递能力,结合生物膜促进回路,显著提升了细菌的电活性和铀回收能力。研究展示了ELMs在不同条件下的自组装能力、电子转移效率和铀回收性能,验证了其在铀回收领域的高效性和稳定性。该工作为电活性活体材料在环境修复与资源回收方面的应用提供了新的技术路径和理论支持
参考文献:Li FH, Liang ZH, Sun H, Tang Q, Yu HQ. Engineering Programmable Electroactive Living Materials for Highly Efficient Uranium Capture and Accumulation. Environ Sci Technol. 2024 Dec 17.
文章链接https://doi.org/10.1021/acs.est.4c07276


投稿、转载、合作、申请入群可在后台留言(备注:姓名+微信号)或发邮件至sthjkx1@163.com

【点击下方超链接阅读16个栏目推文】 
1.【直播】9.【院士】
2.【视频10.【综述】
3.【健康&毒理11.【写作】
4.【12.【Nature】
5.【13.【Science
6.【14.【WR
7.【固废15.【EST
8.【生态】16.【JHM

生态环境科学
最新学术成果与讯息
 最新文章