State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin, 150090, China; School of Marine Science and Technology, Harbin Institute of Technology at Weihai, Weihai, 264209, PR China.
State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin, 150090, China.
Chemosphere. 2021 Jul;274:129744. doi: 10.1016/j.chemosphere.2021.129744. Epub 2021 Jan 22.
Though sulfamethoxazole (SMX) degradation at the low or medium concentration (SMX< 30 mg/L) has been reported in the microbial fuel cell (MFC), further exploration is still urgently required to investigate how the high concentration of SMX affect the anode biofilm formation. In this study, the degradation mechanism of SMX and the response of microbial community to SMX at different initial concentrations (0, 0.5, 5 and 50 mg/L) were investigated in MFCs. The highest SMX removal efficiency of 98.4% was obtained in MFC (5 mg/L). SMX at optimal concentration (5 mg/L) could serve as substrate accelerating the extracellular electron transfer. However, high concentration of SMX (50 mg/L) conferred significant inhibition on the electron transfer with SMX removal decline to 84.4%. The 16S rRNA high-throughput sequencing revealed the significant shift of the anode biofilms communities with different initial SMX concentrations were observed in MFCs. Thauera and Geobacter were the predominant genus, with relative abundance of 31.9% in MFC (50 mg/L SMX) and 52.7% in MFC (5 mg/L SMX). Methylophilus exhibited a huge increase with the highest percentage of 16.4% in MFC (50 mg/L). Hence, the functional bacteria of Thauera, Geobacter and Methylophilus endowed significant tolerance to the selection pressure from high concentration of SMX in MFCs. Meanwhile, some bacteria including Ornatilinea, Dechloromonas and Longilinea exhibited a decrease or even disappeared in MFCs. Therefore, initial concentrations of SMX played a fundamental role in modifying the relative abundance of predominant populations. This finding would promote theories support for understanding the evolution of anode biofilm formation related to the different initial concentrations of SMX in MFCs.
尽管在微生物燃料电池 (MFC) 中已经报道了低浓度或中浓度 (SMX<30mg/L) 下磺胺甲恶唑 (SMX) 的降解，但仍迫切需要进一步探索高浓度 SMX 如何影响阳极生物膜的形成。在这项研究中，在 MFC 中研究了 SMX 的降解机制以及微生物群落对不同初始浓度 (0、0.5、5 和 50mg/L) 的 SMX 的响应。在 MFC(5mg/L) 中获得了最高的 SMX 去除效率 98.4%。在最佳浓度 (5mg/L) 下的 SMX 可以作为加速细胞外电子传递的基质。然而，高浓度的 SMX(50mg/L) 对电子传递产生了显著的抑制作用，SMX 的去除率下降到 84.4%。16S rRNA 高通量测序显示，在不同初始 SMX 浓度的 MFC 中观察到阳极生物膜群落发生了显著变化。Thauera 和 Geobacter 是主要属，在 MFC(50mg/L SMX) 中的相对丰度为 31.9%，在 MFC(5mg/L SMX) 中的相对丰度为 52.7%。Methylophilus 的增幅最大，在 MFC(50mg/L SMX) 中的百分比为 16.4%。因此，Thauera、Geobacter 和 Methylophilus 的功能细菌对 MFC 中高浓度 SMX 的选择压力表现出显著的耐受性。同时，一些细菌，包括 Ornatilinea、Dechloromonas 和 Longilinea，在 MFC 中减少甚至消失。因此，SMX 的初始浓度在改变主要种群的相对丰度方面起着根本作用。这一发现将促进对理解与 MFC 中不同初始 SMX 浓度相关的阳极生物膜形成的演变的理论支持。
