Soil microbiome is the cornerstone of sustaining soil ecosystem services and performs an array of vital soil functions. Manipulating soil microbiome is a promising strategy to regulate soil ecosystem function, however, the effect and underlying mechanism for chlorinated organic pollution remediation are limited and the capacity to simultaneously control multiple redox processes is still unclear. Here, the dynamics of the biocathode microbial community after separately or synchronously adding conductive material and acyl-homoserine lactone (AHL) were investigated from the perspectives of electron transfer and microbial assembly in γ-hexachlorocyclohexane (γ-HCH) polluted soil-based bioelectrochemical system. The resulting responses of NO/Fe(III)/SO reduction, γ-HCH dechlorination, and CH cumulation were also analyzed. Two conductive materials of biochar (BC) and magnetite nanoparticle (NaFe) and two AHLs including N-butanoyl homoserine lactone (C4-HSL) and 3-oxo-hexanoyl-homoserine lactone (3OC6-HSL) were applied. Exogenous additives facilitated γ-HCH dechlorination but alleviated and even inhibited CH cumulation, with BC plus C4-HSL addition as the optimum. Adding BC/NaFe enriched Fe(III)-reducing bacteria and dechlorinators and selectively transferred more electrons to those electron sinks; C4-HSL/3OC6-HSL helped to increase biofilm aggregation; while BC plus C4-HSL stimulated the growth of dominant functional taxa and enhanced the compact microbial correlations. These findings broaden our insights and provide approaches to managing soil microbiomes to solve actual environmental emergencies. It shows an advanced strategy to inhibit greenhouse gas (CH) emission when COP reduction is facilitated to achieve win-win soil remediation.

中文翻译：

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导电材料和 AHL 的添加改变了土壤微生物组并促进 γ-HCH 脱氯，但抑制了 CH4 积累

土壤微生物组是维持土壤生态系统服务的基石，发挥着一系列重要的土壤功能。操纵土壤微生物组是调节土壤生态系统功能的一种有前途的策略，然而，氯化有机污染修复的效果和潜在机制有限，同时控制多个氧化还原过程的能力仍不清楚。本文从电子转移和微生物组装的角度研究了γ-六氯环己烷（γ-HCH）污染的土壤生物电化学系统中单独或同步添加导电材料和酰基高丝氨酸内酯（AHL）后生物阴极微生物群落的动态。 。还分析了 NO/Fe(III)/SO 还原、γ-HCH 脱氯和 CH 累积的响应。应用了生物炭（BC）和磁铁矿纳米颗粒（NaFe）两种导电材料以及包括N-丁酰基高丝氨酸内酯（C4-HSL）和3-氧代-己酰基-高丝氨酸内酯（3OC6-HSL）的两种AHL。外源添加剂促进γ-HCH脱氯，但减轻甚至抑制CH积累，其中BC加C4-HSL添加为最佳。添加 BC/NaFe 富集 Fe(III) 还原细菌和脱氯剂，并选择性地将更多电子转移到这些电子汇；C4-HSL/3OC6-HSL有助于增加生物膜聚集；而BC加C4-HSL刺激了优势功能类群的生长并增强了紧密的微生物相关性。这些发现拓宽了我们的见解，并提供了管理土壤微生物组以解决实际环境紧急情况的方法。它展示了一种在促进COP减排的同时抑制温室气体（CH）排放的先进策略，实现双赢的土壤修复。