正文
提升微生物生物量、活性及功能表达
，在Cr(VI)去除方面表现出优越性能。
As shown in Fig. 3a, the OD600 results indicate that the BDOM-NEVO group had the highest biomass (0.353). CCK-8 assays further revealed enhanced electron transfer and enzyme activity (Fig. 3b), likely due to the synergistic effect of NEVO and BDOM. ETSA results demonstrated higher and more sustained electron transfer activity in the BDOM-NEVO group (Fig. 3c), contributing to improved Cr(VI) removal. Enzyme activity was also consistently higher than in single-carbon-source groups (Fig. 3d). Therefore, BDOM-NEVO significantly promotes microbial growth, activity, and functional expression, offering superior performance in Cr(VI) removal.
图3 微生物生理学分析图
（a）I-VI周期微生物数量(OD600)；（b）第I至第VI周期内微生物活性(CCK-8)；（c）电子传递活性和总铬去除率；（d）各周期中微生物的相对酶活性
Fig. 3 Microbial physiology analysis
(a) Microbial abundance (OD600) from cycles I to VI; (b) Microbial activity (CCK-8) during cycles I to VI; (c) Electron transfer activity and total Cr removal rate; (d) Relative enzyme activity of microorganisms in each cycle.
四、BDON-NEVO影响微生物群落演替与代谢分析
| BDOM-NEVO Effects on Microbial Community Succession and Metabolic Analysis
Chao1指数表明碳源添加后物种丰富度下降，说明
微生物对碳源具有选择性
。BDOM的引入不仅增强了
协同效应
，还促进了
优势菌的富集
，使BDOM-NEVO在Cr(VI)降解中表现更优。基因功能分析显示，BDOM-NEVO显著上调
铬还原、脂质代谢、膜运输和碳水化合物代谢相关通路
，增强了微生物活性与代谢能力（图4a）。此外，关键铬还原基因（ChrA、azoR、ChrR、pta、adh）与优势菌属（
Achromobacter
、
Pseudomonas
）呈正相关，进一步表明BDOM-NEVO可
促进抗铬基因表达和菌群生长
，从而提升Cr(VI)去除效率（图4b）。
The Chao1 index showed a decrease in species richness after carbon addition, indicating microbial selectivity. BDOM enhanced synergistic effects and promoted the enrichment of dominant strains, contributing to the superior Cr(VI) removal by BDOM-NEVO. Functional gene analysis revealed significant upregulation of pathways related to chromium reduction, lipid metabolism, membrane transport, and carbohydrate metabolism (Fig. 4a). Key Cr-reducing genes (ChrA, azoR, ChrR, pta, adh) were positively correlated with dominant genera (
Achromobacter
and
Pseudomonas
), suggesting that BDOM-NEVO promotes gene expression and microbial growth, thereby enhancing Cr(VI) removal efficiency (Fig. 4b).
图4 微生物功能和基因分析图
（a）不同碳源条件下的反应途径和功能基因；（b）不同环境因素、基因、微生物属之间的相关性热图分析
Fig. 4 Microbial functional and gene analysis
(a) Reaction pathways and functional genes under different carbon source conditions;(b) Correlation heatmap analysis among different environmental factors, genes, and microbial genera.
本研究探讨了不同碳源（NEVO、BDOM 和
BDOM-NEVO
）对地下水中低浓度 Cr(VI) 自然衰减的增强效果及其机制。相比单一碳源，BDOM-NEVO显著提高了去除效率，反应速率加快，半衰期缩短。微生物生理与功能基因分析表明，BDOM-NEVO通过促进微生物生长、增强酶和电子传递活性、优化群落结构及代谢功能，有效提升了Cr(VI)的降解能力。本研究为
低浓度 Cr(VI) 地下水污染
的生物修复提供了重要参考。
This study investigated the effects and mechanisms of different carbon sources (NEVO, BDOM, and BDOM-NEVO) on the natural attenuation of low-concentration Cr(VI) in groundwater. Compared to single carbon sources, BDOM-NEVO significantly enhanced removal efficiency, increased reaction rates, and shortened half-lives. Microbial physiological and gene analyses revealed that BDOM-NEVO promoted microbial growth, enhanced enzyme and electron transfer activity, and optimized community structure and metabolism, thereby improving Cr(VI) degradation. These findings provide valuable insights for the bioremediation of low-level Cr(VI) contamination in groundwater.
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https://www.sciencedirect.com
/science/article/pii/S23521864
24004437
本文内容来自
ELSEVIER
旗舰期刊
Environ Technol Innov
第37卷发表的论文：
Zhou Z.J., Wang S.Y., He B.N., He J.T., Zou H., L M.M., 2025. Reinforcing natural attenuation of Cr(VI) in groundwater through single- and composite BDOM-NEVO reagents: Performance contrast and mechanistic insights. Environ Technol Innov 37, 103967.
