六价铬的微生物还原机制及其环境影响研究进展

Research progress in bioreduction mechanisms for hexavalent chromium and environmental implications

摘要:

六价铬[hexavalent chromium, Cr(VI)]是广泛存在于电镀、冶金、染料制造等工业废水中的重金属污染物，具有强氧化性、高生物毒性且水溶性好，是水体和土壤污染的重点治理对象。传统Cr(VI)污染防治技术见效较快，但存在成本高、二次污染问题严重以及处理效果易受环境条件影响等弊端。相比之下，借助微生物还原Cr(VI)以降低其环境危害的生物处理技术具有能耗低、环境友好且可持续性强等优势，日益成为Cr(VI)污染治理的热点。本文系统介绍了微生物还原Cr(VI)的核心机制，涵盖关键还原酶、胞内与胞外电子传递途径、调控基因表达以及微生物群落的生态适应策略。同时，深入探讨了反硝化与硫循环等能量代谢过程在Cr(VI)还原中的协同效应，揭示多污染物共存条件下的电子竞争与代谢通路调节机制。针对不同环境因子(如pH值、温度、Cr浓度、电子供体类型)，归纳了调控微生物还原效率的措施，并结合典型案例分析了微生物修复技术在实际应用中的脱毒效率、群落变化及生态重构表现。最后，本文展望了合成生物学在工程菌株构建、多组学技术在代谢通路解析、人工智能(artificial intelligence, AI)与原位传感技术在动态调控中的应用前景，提出了以“智能识别-自适应响应-多功能协同”为核心的微生物修复发展方向，为Cr(VI)污染原位治理提供理论基础与技术支撑。

Abstract:

Hexavalent chromium [Cr(VI)] is a widespread and highly toxic heavy metal contaminant commonly found in industrial effluents from electroplating, metallurgy, and dye manufacturing. Due to its strong oxidizing nature, high solubility, and severe biological toxicity, Cr(VI) is recognized as a priority contaminant to be managed in aquatic and terrestrial environments. Although conventional treatment technologies can rapidly reduce Cr(VI) concentrations, they often entail high costs, pose risks of secondary pollution, and are susceptible to environmental fluctuations. Bioreduction of Cr(VI) has emerged as a promising alternative, offering advantages such as low energy requirements, environmental compatibility, and operational sustainability. This review provides a comprehensive overview of the core mechanisms underlying Cr(VI) bioreduction, which involve key chromate reductases, intracellular and extracellular electron transfer pathways, gene regulatory networks, and adaptive strategies of microbial communities under stress. Furthermore, we discuss the synergistic contributions of metabolic pathways, such as denitrification and sulfur cycling, to elucidate electron competition and pathway modulation in complex multi-contaminant systems. Subsequently, we analyze the effects of environmental parameters including pH, temperature, Cr concentration, and electron donor types on bioreduction efficiency. Representative studies are discussed to illustrate detoxification performance, community succession, and ecological restoration outcomes under field conditions. Finally, this review envisions future advances in microbial remediation through the application of synthetic biology to construct engineered microbial strains, the use of multi-omics technologies to elucidate metabolic pathways, and the integration of artificial intelligence (AI) with in situ sensing technologies for dynamic regulation. It further outlines a developmental framework centered on “intelligent detection-adaptive response-multifunctional coordination”, providing both a theoretical foundation and technological guidance for the in situ remediation of Cr(VI) contamination.