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学院发表文章

Molecular density regulating electron transfer efficiency of S. oneidensis MR-1 mediated roxarsone biotransformation

发布日期:2020-05-29浏览次数:信息来源:快3官网app科学与技术学院

Gang Wang   Neng Han   Li Liu   Zhengchen Ke   Baoguo Li   Guowei Chen

Abstract

Efficient extracellular electron transport is a key for sufficient bioremediation of organoarsenic pollutants such as 4-hydroxy-3-nitrobenzenearsonic acid (roxarsone). The related apparent kinetics characteristics are essential for engineering practice of bioremediation activities and for full understanding the environmental fate of roxarsone, yet remains poorly understood. We report, to our knowledge, the first study of the electron transfer characteristics between roxarsone and participating S. oneidensis MR-1. The electron transfer rate during roxarsone biotransformation was estimated up to 3.1 × 106 electrons/cell/s, with its value being clearly associated with the apparent roxarsone concentration. Lowing roxarsone concentration extended the average separation distance between cells and neighboring roxarsone molecules and thereby augmented electric resistance as well as extended cell movement for foraging, thus reduced electron transfer rate. In addition, the presence of roxarsone significantly stimulated population growth of S. oneidensis MR-1 with nearly doubled maximum specific growth rate, albeit with clearly increased lag time, as compared with that of none-roxarsone scenario. These findings provide, at the first time, basic biostoichiometry of S. oneidensis MR-1 induced roxarsone biotransformation, which may shed lights for full understanding of roxarsone transformation process in waste treatment systems that are necessary for engineering practice and/or environmental risks assessment.

Keywords

Electron transfer; Kinetics; Roxarsone transformation; Shewanella oneidensis MR-1

 

Molecular density regulating electron transfer efficiency of S. oneidensis MR-1 mediated roxarsone biotransformation.pdf