This study explores the toxic effect of TCE at different depths of sub-surface soil and underpins microbial community-level suitable carbon (C)-sources that provided directionality to the in situ biostimulation effort via augmentation strategy for effective TCE remediation in soil. The impacts on resident microbial communities and their functional profiles that govern the TCE biodegradation process were identified. Highly contaminated PW01 soil (9 m depth) had severely limited microbial diversity and was enriched in Proteobacteria and Firmicutes. The abundance of TCE degradation-associated genera was observed in all contaminated samples, and the abundance of TCE-degradation-related taxa were positively correlated with soil TCE contamination levels. Community-level metabolic activity associated with the utilization of diverse external C-sources was directly influenced by TCE concentration and soil depth. Multivariate data analysis revealed that the functional genus, TCE concentration, and selected available C substrate uptake capacity correlated in soil samples. Pearson’s correlation tests revealed that C sources such as L-arginine, phenylethylamine and γ-hydroxybutyric acid utilization trait exhibited significant positive correlations with chloroalkane and chloroalkene degradation pathway abundance. Ultimately, depth and TCE contamination level-associated soil microbiota and their most preferred C-source understanding could add to facilitate effective biostimulation via external nutrient amendment for efficient in situ TCE degradation.

本研究探讨了 TCE 在地下土壤不同深度的毒性作用，并支持微生物群落水平的合适碳 (C) 源，通过增强策略为土壤中有效的 TCE 修复提供方向性的原位生物刺激工作。确定了对控制 TCE 生物降解过程的常驻微生物群落及其功能特征的影响。高度污染的 PW01 土壤（9 m 深）的微生物多样性严重受限，富含变形菌门和厚壁菌门。在所有污染样品中均观察到TCE降解相关属的丰度，TCE降解相关类群的丰度与土壤TCE污染水平呈正相关。与利用多种外部 C 源相关的社区水平代谢活动直接受 TCE 浓度和土壤深度的影响。多变量数据分析表明，功能属、TCE 浓度和选择的可用 C 底物吸收能力在土壤样品中相关。Pearson 的相关性检验表明，C 源如L-精氨酸、苯乙胺和γ-羟基丁酸利用性状与氯代烷和氯代烯烃降解途径丰度呈显着正相关。最终，与深度和 TCE 污染水平相关的土壤微生物群及其最喜欢的 C 源理解可以通过外部养分改良促进有效的生物刺激，从而有效地原位 TCE 降解。