Dissimilatory iron-reducing microorganisms: The phylogeny, physiology, applications and outlook

Dissimilatory iron reduction (DIR) is an important form of microbial respirations and a key part of iron biogeochemical cycle. A wide range of both bacteria and archaea that can conserve energy through Fe(III) reduction are called dissimilatory iron-reducing microorganisms (DIRMs). They have been increasingly recognized as important for coupling organic carbon oxidation in diverse anaerobic environments, such as soil, sediments, freshwater, marine water as well as extreme environments. In parallel with their phylogenetic diversity, DIRMs possess metabolic versatility, including multiple extracellular electron transfer (EET) pathways and various electron donors as well as acceptors. In this review, phylogenetic, environmental distribution of DIRMs was demonstrated comprehensively by summarizing 51 isolated DIRMs belonging to 27 genera in previous literature. EET mechanisms were further elaborated on based on four DIRMs representatives: <i>Geobacter</i>, <i>Shewanella</i>, Gram-positive bacteria and archaea. Various electron donors, acceptors, and novel metabolisms revealed recently prompt the development of DIRMs biotechnological applications, including bioleaching, bioremediation, biosynthesis, anaerobic fermentation, and production of bioelectricity. Although past decades have witnessed a great increase of the publications in DIRMs, further investigation are required for deep understanding and practical applications, such as their roles in natural environments, EET mechanisms in different DIRMs, cooperation with other microbes, and mechanisms of improved bioproduction by adding iron-oxides. DIRMs in real world. (1) they can be used for bioleaching; (2) they can be used for bioremediation for heavy metals and organic pollutants; (3) in aquatic environments, they can conduct iron reduction and form iron precipitate; (4) they can be used to produce current; (5) they can synthesize bioproducts; (6) they can form stable network with other soil microorganisms; (7) in various environments, they can form microbial iron cycle with iron-oxidizing microorganisms and influence many processes.

异化铁还原（Dissimilatory Iron Reduction, DIR）是微生物呼吸作用的重要形式，亦是铁生物地球化学循环的核心环节。各类可通过还原三价铁（Fe(III)）获取能量的细菌与古菌，统称为异化铁还原微生物（Dissimilatory Iron-Reducing Microorganisms, DIRMs）。这类微生物在多种厌氧环境（如土壤、沉积物、淡水、海水乃至极端环境）中耦合有机碳氧化的关键作用日益受到重视。除系统发育多样性外，异化铁还原微生物还具备代谢多功能性，包括多种胞外电子传递（Extracellular Electron Transfer, EET）途径以及多样的电子供体与受体。本综述通过梳理既往文献中隶属于27个属的51株分离纯化的异化铁还原微生物，全面阐述了该类微生物的系统发育特征与环境分布格局；并以四种典型类群——地杆菌属（Geobacter）、希瓦氏菌属（Shewanella）、革兰氏阳性细菌以及古菌为代表，进一步阐释了其胞外电子传递机制。近年来陆续发现的多样电子供体、受体与新型代谢途径，推动了异化铁还原微生物的生物技术应用发展，其应用场景涵盖生物浸矿、生物修复、生物合成、厌氧发酵以及生物电能生产。尽管近数十年来异化铁还原微生物领域的研究文献数量显著增长，但仍需开展更多研究以深化对该类微生物的认知并推动其实际应用，例如其在自然环境中的生态功能、不同类群异化铁还原微生物的胞外电子传递机制、与其他微生物的协同互作，以及添加铁氧化物促进生物合成的相关机制等。目前异化铁还原微生物在现实场景中具备如下功能：(1) 可用于生物浸矿；(2) 可用于重金属与有机污染物的生物修复；(3) 在水生环境中可介导铁还原反应并形成铁沉淀物；(4) 可用于产生电流；(5) 可合成生物基产品；(6) 可与其他土壤微生物形成稳定的群落网络；(7) 在各类环境中可与铁氧化微生物共同构建微生物铁循环，并对诸多生态过程产生影响。

搜集汇总

背景与挑战

背景概述

该数据集聚焦于异化铁还原微生物（DIRMs）的系统发育、生理学和应用，总结了51种DIRMs的分类和电子传递机制，并探讨了其在生物技术领域的多种应用，如生物浸出、生物修复和生物电生产。