CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, P. R. China; University of Chinese Academy of Sciences, Beijing 100049, P. R. China.
CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, P. R. China.
Bioelectrochemistry. 2022 Oct;147:108195. doi: 10.1016/j.bioelechem.2022.108195. Epub 2022 Jun 23.
Under visible light, non-photosynthetic microorganism/semiconductor has recently shown promising applications in biofuel production, bioenergy generation and pollutant removal. However, the understanding of electron transfer mechanism at the biotic-abiotic interface is limited. Herein, mixed culture/carbon nitride and pure culture (Stenotrophomonas maltophilia HP14)/carbon nitride were constructed to reveal the energy conversion pathway under visible light. Enhanced electron transfer was observed on the biotic-abiotic interface. The photocurrent of non-photosynthetic S. maltophilia HP14/g-CN/ITO with riboflavin addition was 10.2-fold higher than that of g-CN/ITO control. As the electron donor, S. maltophilia HP14 transfer bio-electrons to self-secreted riboflavin and valence band of semiconductor. Riboflavin (RF) accept bio-electrons and photogenerated electrons to form 1,5-dihydroflavin (RFH). While RFH is able to transfer electrons to the valence band of carbon nitride and transform into RF again. However, riboflavin is not stable under visible light irradiation, which may lead to a decreased photocurrent. This study demonstrated the role of redox active compounds at the microorganism/semiconductor interface and described a possibility for non-photosynthetic microorganisms to capture and utilize visible light.
在可见光下，非光合微生物/半导体最近在生物燃料生产、生物能源产生和污染物去除方面显示出很有前景的应用。然而，生物-非生物界面上的电子转移机制的理解是有限的。在此，构建了混合培养/氮化碳和纯培养（嗜麦芽寡养单胞菌 HP14）/氮化碳，以揭示可见光下的能量转换途径。在生物-非生物界面上观察到了增强的电子转移。添加核黄素后，非光合嗜麦芽寡养单胞菌 HP14/g-CN/ITO 的光电流比 g-CN/ITO 对照提高了 10.2 倍。作为电子供体，嗜麦芽寡养单胞菌 HP14 将生物电子转移到自身分泌的核黄素和半导体的价带。核黄素（RF）接受生物电子和光生电子形成 1,5-二氢黄素（RFH）。而 RFH 能够将电子转移到氮化碳的价带，并再次转化为 RF。然而，核黄素在可见光照射下不稳定，这可能导致光电流降低。本研究证明了氧化还原活性化合物在微生物/半导体界面上的作用，并描述了非光合微生物捕获和利用可见光的可能性。
