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: Geobacter, Shewanella, 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.

中文翻译：

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异化还原铁微生物的系统发育、生理学、应用和展望


异化铁还原 （DIR） 是微生物呼吸的一种重要形式，也是铁生物地球化学循环的关键部分。可以通过 Fe（III） 还原来节省能量的多种细菌和古细菌称为异化铁还原微生物 （DIRM）。它们越来越被认为对于在各种厌氧环境（如土壤、沉积物、淡水、海水以及极端环境）中耦合有机碳氧化非常重要。除了系统发育多样性外，DIRM 还具有代谢多功能性，包括多个细胞外电子转移 （EET） 途径和各种电子供体和受体。本文通过总结以往文献中 27 个属的 51 个分离的 DIRM，全面展示了 DIRMs 的系统发育和环境分布。根据 4 个 DIRMs 代表进一步阐述了 EET 机制：Geobacter、Shewanella、革兰氏阳性菌和古细菌。最近发现的各种电子供体、受体和新型代谢促进了 DIRM 生物技术应用的发展，包括生物浸出、生物修复、生物合成、厌氧发酵和生物电的生产。尽管过去几十年见证了 DIRM 出版物的大幅增加，但需要进一步研究以深入了解和实际应用，例如它们在自然环境中的作用、不同 DIRM 中的 EET 机制、与其他微生物的合作以及通过添加氧化铁改善生物生产的机制。