典型重金属对氯苯类有机物生物转化影响及分子机制研究进展

Progress in the effects and molecular mechanisms of typical heavy metals on the biotransformation of chlorobenzenes

摘要:

重金属和有机物相互作用，形成共污染，是当今面临的重要环境问题之一。明晰重金属作用下氯苯类化合物（chlorobenzenes，CBs）的转化特性以及典型重金属对CBs生物降解的影响机制，对有效修复重金属-有机物共污染有重要意义。本文首先对CBs生物降解的研究现状进行了总结，明晰了当前CBs降解的主要功能菌属类型，包括伯克霍尔德菌（Burkholderia），假单胞菌（Pseudomonas），脱卤球菌（Dehalobium）和脱卤拟球菌（Dehalococcoides）等；而后概述了重金属与CBs的共污染现状，发现绝大多数污染中存在重金属与CBs共污染现象；随后系统综述了典型重金属对CBs生物转化的影响，表明好氧或厌氧条件下大多数重金属离子对CBs生物转化存在抑制作用，受金属离子种类、浓度、价态及pH影响显著；另外，对重金属影响下的CBs转化机制进行了分析，基于3方面影响构建了分子机制模型。最后对目前还存在的问题与局限性进行了分析，并对未来发展方向进行了展望，以期为重金属-有机物共污染的修复提供支撑。

Abstract:

The co-pollution of heavy metals and organic compounds is one of the major environmental issues today. Understanding the degradation and transformation characteristics of chlorobenzenes (CBs) under the influence of heavy metals is of great significance for remediation of the co-pollution. We summarized the current research status of CB biodegradation, clarified the main functional bacterial genera including Burkholderia, Pseudomonas, Dehalobium, and Dehalococcoides involved in CB degradation, and then outlined the co-pollution status of heavy metals and CBs. The co-pollution of heavy metals and CBs exists in the vast majority of pollution cases. Further, we systematically reviewed the effects of typical heavy metals on the biotransformation and degradation of CBs. Most heavy metal ions exert inhibitory effects on the biotransformation and degradation of CBs under aerobic or anaerobic conditions, and their inhibitory effects are significantly influenced by pH and the species, concentration, and valence state of heavy metals. In addition, the mechanisms of CB transformation and degradation under the influence of heavy metals were analyzed. A molecular mechanism model was constructed with consideration to three influencing mechanisms. Finally, we analyzed the current problems and limitations and prospected the future development direction, aiming to provide support for the remediation of heavy metal-organic co-pollution.