腐殖质电化学特性及其介导的胞外电子传递研究进展  

Progress in study of humic substances: electrochemical redox characterization Progress in study of humic substances: electrochemical redox characterization and extracellular respiration

作　　者：蔡茜茜[1,2] 袁勇[2] 胡佩[1] 周顺桂[2] 唐家桓[2] 

机构地区：[1]四川师范大学化学与材料科学学院,成都610066 [2]广东省生态环境与土壤研究所广东省农业环境综合治理重点实验室,广州510650

出　　处：《应用与环境生物学报》2015年第6期996-1002,共7页Chinese Journal of Applied and Environmental Biology

基　　金：国家自然科学基金项目(21277035);广东省杰出青年基金项目(2014A030306033);广州市科技计划项目(201510010025)资助~~

摘　　要：腐殖质是环境中广泛存在的富含醌基、非均相的天然有机混合物,是土壤中的主要电活性物质,在环境微生物驱动的电子转移过程有重要作用.本文介绍了腐殖质氧化还原活性及其电子转移能力的表征方法,并详细对比了不同测定方法的优缺点;阐述了腐殖质介导的胞外电子传递胞外电子传递过程,其本质是环境微生物以腐殖质作为电子受体,氧化环境中的有机小分子物质,并偶联能量的产生和支持菌体的生长,形成一种新型厌氧呼吸形式——腐殖质呼吸;腐殖质呼吸作用产生的还原态腐殖质可以还原环境中的一些氧化态污染物质,如重金属、有机污染物和有机染料等.此外,腐殖质也可以介导微生物与固体电极间的电子传递,从而促进生物电化学系统中的生物电流产生.由于腐殖质介导的微生物胞外电子传递机制复杂,未来将主要通过现代光学和蛋白组学等最新技术来研究微生物胞外电子传递过程以及其与腐殖质的相互作用机制;此外,采用醌基修饰等方法增强腐殖质的电子转移能力,有望加速其介导的微生物胞外电子传递过程,以便将其应用于实际环境修复.Humic substances（HS） are ubiquitous heterogeneous mixtures of natural organic macromolecules in the environment. They are rich in quinone moieties that provide redox activity, which is recognized as the main electrochemical active substances in the soil and plays an impor tant role in extracellular electron transfer driven by environmental microorganisms. In this paper, we reviewed the redox activity of HS, and summarized the methods to characterize the electron transfer capacity of HS. We also described the advantages and disadvantages of these different measuring methods. Meanwhile, we described the process of extracellular electron transfer mediated by HS. In such a process, HS can function as electron acceptors in the microbial oxidation of small organic matters, which is coupled by the energy production for cell growth. This process is called humus respiration. The reduced HS produced in the humus respiration can further reduce many environmental pollutants including heavy metals and organic pollutants and dyes. In addition, HS can even mediate the electron transfer between microbial cells and solid electrodes, promoting biocurrent generation in microbial electrochemical systems. Due to the complex mechanism of the extracellular electron transfer mediated by HS, the advanced optics and proteomics te chniques will be applied to further probe the interaction between microbial cells and HS in near future. On the other hand, HS modified with electroactive moieties is expected to enhance their electron transfer capacity, which will promote the practical application of HS to environmental remediation.

关 键 词：腐殖质 电化学活性 可逆 电子穿梭体 胞外电子传递 胞外呼吸 

分 类 号：X172[环境科学与工程—环境科学] X144