Zheng Xusheng, Li Xiaoyue, Liu Yanping, Liu Guangqing, Yang Ziyi, Zou Dexun
Department of Environmental Science & Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
Toxics. 2025 Aug 22;13(9):708. doi: 10.3390/toxics13090708.
Extracellular electron transfer is crucial in the microbial reduction of hexavalent chromium [Cr(VI)], and N-acylated--homoserine lactones (AHLs) could accelerate this process. In this study, fulvic acid (FA) was used as an electron shuttle to enhance the microbial reduction process via stimulating extracellular electron transfer efficiency. Compared with 9,10-anthraquinone-2-sulfonic acid (AQS), FA had a stronger positive effect on Cr(VI) reduction by , showing the ability of stimulating to release AHLs. The concentrations of C6-HSL, C8-HSL and 3OC10-HSL increased by 11.79 ng/L, 19.82 ng/L and 3.01 ng/L after the addition of 2% FA. The bioinformation analysis indicated that AHLs could regulate the synthesis of electron shuttles by , such as riboflavin. And the addition of exogenous C6-HSL, C8-HSL, C10-HSL, C12-HSL and 3OC10-HSL increased the Cr(VI) reduction rates by 1.73%, 2.39%, 4.18%, 1.45% and 2.70%, because they could promote the release of riboflavin. It revealed a new pathway by which FA promoted microbial Cr(VI) reduction. This study also provides a novel approach for enhancing the microbial Cr(VI) reduction and a deeper understanding of the communication mechanism among microorganisms.
细胞外电子转移在微生物还原六价铬[Cr(VI)]过程中至关重要，N-酰基高丝氨酸内酯（AHLs）可加速这一过程。在本研究中，富里酸（FA）被用作电子穿梭体，通过刺激细胞外电子转移效率来增强微生物还原过程。与9,10-蒽醌-2-磺酸（AQS）相比，FA对Cr(VI)还原具有更强的正向作用，表明其具有刺激释放AHLs的能力。添加2% FA后，C6-HSL、C8-HSL和3OC10-HSL的浓度分别增加了11.79 ng/L、19.82 ng/L和3.01 ng/L。生物信息分析表明，AHLs可通过调节某些物质（如核黄素）来调控电子穿梭体的合成。添加外源C6-HSL、C8-HSL、C10-HSL、C12-HSL和3OC10-HSL可使Cr(VI)还原率分别提高1.73%、2.39%、4.18%、1.45%和2.70%，因为它们可促进核黄素的释放。这揭示了FA促进微生物还原Cr(VI)的一条新途径。本研究还为增强微生物还原Cr(VI)提供了一种新方法，并加深了对微生物间通讯机制的理解。
