Shenyang National Laboratory for Materials Science, Northeastern University, Shenyang, China; Electrobiomaterials Institute, Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), Northeastern University, Shenyang, China.
College of Ocean Science and Engineering, Shanghai Maritime University, Shanghai, China.
Adv Microb Physiol. 2021;78:317-390. doi: 10.1016/bs.ampbs.2021.01.002. Epub 2021 Mar 2.
Microbially catalyzed corrosion of metals is a substantial economic concern. Aerobic microbes primarily enhance Fe oxidation through indirect mechanisms and their impact appears to be limited compared to anaerobic microbes. Several anaerobic mechanisms are known to accelerate Fe oxidation. Microbes can consume H abiotically generated from the oxidation of Fe. Microbial H removal makes continued Fe oxidation more thermodynamically favorable. Extracellular hydrogenases further accelerate Fe oxidation. Organic electron shuttles such as flavins, phenazines, and possibly humic substances may replace H as the electron carrier between Fe and cells. Direct Fe-to-microbe electron transfer is also possible. Which of these anaerobic mechanisms predominates in model pure culture isolates is typically poorly documented because of a lack of functional genetic studies. Microbial mechanisms for Fe oxidation may also apply to some other metals. An ultimate goal of microbial metal corrosion research is to develop molecular tools to diagnose the occurrence, mechanisms, and rates of metal corrosion to guide the implementation of the most effective mitigation strategies. A systems biology approach that includes innovative isolation and characterization methods, as well as functional genomic investigations, will be required in order to identify the diagnostic features to be gleaned from meta-omic analysis of corroding materials. A better understanding of microbial metal corrosion mechanisms is expected to lead to new corrosion mitigation strategies. The understanding of the corrosion microbiome is clearly in its infancy, but interdisciplinary electrochemical, microbiological, and molecular tools are available to make rapid progress in this field.
微生物催化的金属腐蚀是一个重大的经济问题。好氧微生物主要通过间接机制促进 Fe 的氧化，其影响似乎比厌氧微生物有限。已知有几种厌氧机制可以加速 Fe 的氧化。微生物可以消耗由 Fe 氧化产生的 H 。微生物 H 的去除使 Fe 的持续氧化在热力学上更加有利。细胞外氢化酶进一步加速了 Fe 的氧化。黄素、苯并嗪和可能的腐殖质等有机电子穿梭体可以代替 H 作为 Fe 和细胞之间的电子载体。直接的 Fe 到微生物的电子转移也是可能的。由于缺乏功能遗传研究，这些厌氧机制在模型纯培养物分离物中占主导地位的情况通常记录不佳。微生物 Fe 氧化的机制也可能适用于其他一些金属。微生物金属腐蚀研究的最终目标是开发分子工具来诊断金属腐蚀的发生、机制和速率，以指导实施最有效的缓解策略。为了从腐蚀材料的元组学分析中获取可用于诊断的特征，需要采用包括创新的分离和表征方法以及功能基因组研究的系统生物学方法。对微生物金属腐蚀机制的更好理解有望带来新的腐蚀缓解策略。对腐蚀微生物组的理解显然还处于起步阶段，但现有的电化学、微生物学和分子交叉学科工具可用于在该领域取得快速进展。
