摘要
深入理解生物大分子与重金属相互作用的微观机制对于生态环境污染治理具有重要意义.近年来,随着现代谱学、显微方法以及组学技术的应用,生物大分子与重金属结合强度、配位结构、氧化还原过程及其生物学调控过程取得了重要进展,这些研究在分子尺度极大丰富了相关机制的认识.本综述在总结生物大分子与重金属相互作用最新研究方法及其机制的基础上,指出未来亟须发展生物大分子结构与组成表征的方法体系,探究功能性生物大分子参与的重金属吸附与氧化还原过程,揭示复合生物膜系统中微生物功能和重金属形态转化之间的耦合机制,推进重金属与环境组分相互作用的理解从官能团到功能分子尺度的跨越.通过方法集成与创新、机制解析与应用,为水体和土壤重金属污染治理提供有效策略与精准技术.
Heavy metal pollution is a serious threat to both human health and the economic development of China. In soil environments, microbial derived organic substances contribute more than 50% of soil organic matter, which controls the migration and transformation of heavy metals. Over time, the microorganisms have developed a range of resistance and detoxification strategies to deal with the toxicity of heavy metals. Microorganisms play important roles in pollution remediation, hence, a comprehensive understanding of the underlying interaction mechanisms between biomacromolecules and heavy metals is fundamental for the development of microbial remediation methods. In recent years, the application of spectroscopic, thermodynamic, and omics approaches has expanded our understanding of the binding strength,coordination structure, and redox mechanisms of heavy metals and biomacromolecules. X-ray absorption fine structure(XAFS) and X-ray emission spectroscopy(XES) measured the valence state, coordination atom, and the structure of heavy metals in biomacromolecules. Three-dimensional excitation-emission matrix(3D-EEM), Fourier transform infrared spectroscopy(FTIR) and Raman spectroscopy detected the reactive groups in the biomacromolecules through changes in the fluorescent and vibrational spectrum. The thermodynamic information for the reactions between biomacromolecules and heavy metals was detected using isothermal titration calorimetry(ITC) and the surface complexation model(SCM).Most of the models assumed the interactions between carboxyl, phosphoryl, sulfhydryl groups, and heavy metal ions through a monodentate complex. The synthesis and secretion of extracellular polymeric substance(EPS) is the universal mechanism through which microorganisms resist heavy metal stress, though the composition of EPS varied among microorganisms and heavy metals. Furthermore, the microorganisms have evolved functional proteins to fix and detoxify heavy metals, mainly through the sulfhydryl groups in metallothionein, flagellin, and amyloid. The hemiacetal groups, ctype cytochromes, and related functional sites in biomacromolecules promoted the redox of As, Cr, Cu, Ag, and Hg.Meanwhile, the microorganisms regulate the redox processes through a variety of genetically encoded pathways. These indepth understanding of the interactions between biomacromolecule and heavy metal is essential for the treatment of heavy metal pollution using microbial resources.Despite the salient accomplishments cited above, there is a significant knowledge gap regarding the molecular level interactions between microorganisms and heavy metals. The structure and physiological regulation of the functional biomolecules involved in the stabilization and transformation of heavy metals are still unclear. Additionally, the behavior of heavy metals in combined pollution systems and the role of biofilms in their transformation is also not clear. Furthermore,the majority of available literature mainly adopted methodologies from either the chemical or biological field, and the absence of interdisciplinary studies may account for these knowledge gaps. Therefore, it is important to combine the biological and chemical technologies and focus on the interactions between the microbial community, function, and heavy metals in composite biofilms. It is paramount to develop methods for the extraction and characterization of the biomolecules and to investigate their electron transfer and complexation reactions with heavy metals. More attention should be given to combined pollution systems and the interactions between metal-small molecular complexes and biomacromolecules. These studies will promote the understanding of the interactions between heavy metals and functional biomolecules at the molecular level, and improve the effectiveness of microbial remediation for heavy metal pollution.Overall, this review summarizes the latest research methodologies and the underlying interaction mechanisms between biomacromolecules and heavy metals and suggests the directions for further research regarding the methodology and systems. The integration of the methodologies, innovation, and a vivid comprehension of the underlying mechanisms will contribute significantly to the development of microbial remediation strategies for heavy metal pollution in water and soil.
作者
渠晨晨
蔡鹏
史凯祥
陈雯莉
陈今朝
高春辉
吴一超
黄巧云
Chenchen Qu;Peng Cai;Kaixiang Shi;Wenli Chen;Jinzhao Chen;Chunhui Gao;Yichao Wu;Qiaoyun Huang(State Key Laboratory of Agricultural Microbiology,Huazhong Agricultural University,Wuhan 430070,China)
出处
《科学通报》
EI
CAS
CSCD
北大核心
2022年第35期4192-4205,共14页
Chinese Science Bulletin
基金
国家重点研发计划(2020YFC1806803)
国家自然科学基金(41877029,42177281,42007014)资助。
