Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Key Laboratory for Chemical Biology of Fujian Province, Xiamen University, Xiamen, China.
Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Key Laboratory for Chemical Biology of Fujian Province, Xiamen University, Xiamen, China; College Food and Biological Engineering, Jimei University, Xiamen, China.
J Hazard Mater. 2022 Jun 5;431:128633. doi: 10.1016/j.jhazmat.2022.128633. Epub 2022 Mar 5.
Microbe-photocatalyst biohybrids, integrating the optimal attributes of whole-cell catalysts and nanometer photocatalysts, have emerged as a promising strategy for environment-associated applications. However, few such biohybrids have been tested for complex pollution systems. Herein, we constructed an outer membrane photosensitized Geobacter sulfurreducens (G. sulfurreducens)-CdS biohybrid, which enabled to generate stronger photocurrent in response to irradiation and meanwhile achieved an significant promotion for the redox transformation of Cr(VI) and tetracycline compared with that of bare G. sulfurreducens or CdS counterparts. Further analysis revealed that the outer membrane played a significant role in photoelectron transfer. Differential pulse voltammetry (DPV) tests demonstrated that CdS enhanced the catalytic activity of C-type cytochromes on the outer membrane under irradiation, resulting in the increase of electron-hole pairs separation efficiency. The possible degradation pathway of tetracycline was proposed based on determined intermediates, whose toxicities were well evaluated. Importantly, the toxicity of the final detected intermediates was apparently decreased. Overall, this work aims to explore the working mechanisms of the novel G. sulfurreducens-CdS biohybrid system and opens up a new avenue to purifying combined wastewater by microbe-photocatalyst biohybrids.
微生物-光催化剂杂合体，集成了全细胞催化剂和纳米光催化剂的最佳属性，已成为与环境相关应用的一种很有前途的策略。然而，很少有此类杂合体被用于复杂的污染系统测试。在此，我们构建了一种外膜敏化的脱硫弧菌（G. sulfurreducens）-CdS 杂合体，与裸露的 G. sulfurreducens 或 CdS 相比，它在光照下能够产生更强的光电流，同时显著促进了 Cr(VI)和四环素的氧化还原转化。进一步的分析表明，外膜在光电子转移中起重要作用。差分脉冲伏安法（DPV）测试表明，CdS 在光照下增强了外膜上 C 型细胞色素的催化活性，从而提高了电子-空穴对的分离效率。基于确定的中间产物，提出了四环素的可能降解途径，并对其毒性进行了很好的评估。重要的是，最终检测到的中间产物的毒性明显降低。总的来说，这项工作旨在探索新型 G. sulfurreducens-CdS 杂合体系统的工作机制，并为微生物-光催化剂杂合体净化联合废水开辟了新途径。
