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Abstract：
In this study, highly selenite-resistant strains belonging to Brevundimonas diminuta (OK287021, OK287022) genus were isolated from previously operated single chamber microbial fuel cell (SCMFC). The central composite design showed that the B. diminuta consortium could reduce selenite. Under optimum conditions, 15.38 Log CFU mL-1 microbial growth, 99.08% Se(IV) reduction, and 89.94% chemical oxygen demand (COD) removal were observed. Moreover, the UV-visible spectroscopy (UV) and Fourier transform infrared spectroscopy (FTIR) analyses confirmed the synthesis of elemental selenium nanoparticles (SeNPs). In addition, transmission electron microscopy (TEM) and scanning electron microscope (SEM) revealed the formation of SeNPs nano-spheres. Besides, the bioelectrochemical performance of B. diminuta in the SCMFC illustrated that the maximum power density was higher in the case of selenite SCMFCs than those of the sterile control SCMFCs. Additionally, the bioelectrochemical impedance spectroscopy and cyclic voltammetry characterization illustrated the production of definite extracellular redox mediators that might be involved in the electron transfer progression during the reduction of selenite. In conclusion, B. diminuta whose electrochemical activity has never previously been reported could be a suitable and robust biocatalyst for selenite bioreduction along with wastewater treatment, bioelectricity generation, and economical synthesis of SeNPs in MFCs.
摘要：
在这项研究中,从先前运行的单室微生物燃料电池（SCMFC）中分离出属于Brevundimonasdiminuta（OK287021，OK287022）属的高度耐亚硒酸盐菌株。中心复合材料设计表明，小型双歧杆菌可以减少亚硒酸盐。在最佳条件下，15.38LogCFUmL-1微生物生长，99.08%Se(IV)还原,化学需氧量(COD)去除率为89.94%。此外，紫外可见光谱（UV）和傅里叶变换红外光谱（FTIR）分析证实了元素硒纳米颗粒（SeNPs）的合成。此外,透射电子显微镜(TEM)和扫描电子显微镜(SEM)显示了纳米球的形成。此外,B.diminuta在SCMFC中的生物电化学性能表明，亚硒酸盐SCMFC的最大功率密度高于无菌对照SCMFC的最大功率密度。此外,生物电化学阻抗谱和循环伏安法表征说明了确定的细胞外氧化还原介体的产生，这些介体可能参与亚硒酸盐还原过程中的电子转移进程。总之,B.diminuta的电化学活性从未被报道过，可能是亚硒酸盐生物还原和废水处理的合适和强大的生物催化剂，生物发电，以及在MFC中经济地合成SeNPs。
