Wang Qiong, Zhang Dongdong, Li Xinkai, Wang Yi, Wang Heng, Zhang Zhichao, Song Wei, Guo Peng
Institute of Agricultural Products Processing and Nuclear Agriculture Technology Research, Hubei Academy of Agricultural Sciences, Wuhan, China.
School of International Studies, Ningbo University, Ningbo, China.
Front Microbiol. 2024 Aug 1;15:1452787. doi: 10.3389/fmicb.2024.1452787. eCollection 2024.
Humic electron mediators can facilitate the reductive dehalogenation of organohalogenated compounds by accelerating electron transfer. To investigate the effect of humic electron mediators on the microbial anaerobic reductive dechlorination of Polychlorinated biphenyls (PCBs), three types of humic electron mediators, humin (HM), humic acid (HA), and anthraquinone-2,6-disulfonic acid (AQDS, HA analogs), were added to PCB dechlorination cultures enriched from different sources in terrestrial and marine environments (T and M cultures). The results showed that meta- and para-site dechlorination occurred in the M culture, while only meta-site dechlorination occurred in the T culture. The dechlorination process N and the dechlorination process H or H' are presented in both cultures. HM enhanced PCB dechlorination metabolic activity in both cultures mainly by promoting meta-site dechlorination. HA showed a weak promoting effect on the M culture by promoting para-chlorine removal but inhibited the dechlorination metabolism of the terrestrial-origin culture, inhibiting meta-chlorine removal. AQDS showed inhibitory effects on both cultures by inhibiting the microbial removal of meta-chlorine. High-throughput sequencing and qPCR results suggest that HM is not a carbon source for the potential dechlorinating metabolism of but may promote reductive dechlorination by changing the community structure, and AQDS may inhibit anaerobic reductive dechlorination of PCBs by inhibiting the growth of . This study provides insights into the mechanism of enhancing PCB microbial dechlorination mediated by humic substances and plays a significant role in extending the application prospects of PCBs bioremediation technology.
腐殖质电子介体可以通过加速电子转移促进有机卤化物的还原脱卤。为了研究腐殖质电子介体对多氯联苯（PCBs）微生物厌氧还原脱氯的影响，将三种腐殖质电子介体，即胡敏素（HM）、腐殖酸（HA）和蒽醌-2,6-二磺酸（AQDS，HA类似物）添加到从陆地和海洋环境不同来源富集的PCB脱氯培养物中（T和M培养物）。结果表明，M培养物中发生了间位和对位脱氯，而T培养物中仅发生了间位脱氯。两种培养物中均呈现出脱氯过程N以及脱氯过程H或H'。HM主要通过促进间位脱氯增强了两种培养物中PCB的脱氯代谢活性。HA通过促进对位氯的去除对M培养物表现出较弱的促进作用，但抑制了陆地来源培养物的脱氯代谢，抑制了间位氯的去除。AQDS通过抑制微生物对间位氯的去除对两种培养物均表现出抑制作用。高通量测序和qPCR结果表明，HM不是潜在脱氯代谢的碳源，但可能通过改变群落结构促进还原脱氯，而AQDS可能通过抑制[具体微生物名称未给出]的生长来抑制PCBs的厌氧还原脱氯。本研究为腐殖质介导增强PCB微生物脱氯的机制提供了见解，对拓展PCBs生物修复技术的应用前景具有重要意义。
