Iron is the fourth most-abundant mineral on Earth and makes up about 5% of the Earth's crust. It is an essential component of heme complex and Fe-S cluster binding protein, which play vital roles in aerobic respiration, DNA biosynthesis, TCA-cycle, and oxygen transport and storage. Although iron oxidation states range from -2 to +6, it is not easily available for living organisms since it usually (under aerobic conditions at neutral pH) occurs in its insoluble form. As a redox-sensitive transition element, iron can be used as both electron donor and acceptor. Therefore, the iron cycle is tightly associated with the oxidation and reduction processes which are not only actuated by chemical reactions, but also driven by microorganisms.
The biogeochemical behavior of iron in nature is complex, and its cycling is featured by microbially mediated fluxes between intracellular and extracellular reservoirs. Iron being essential to living organisms, its acquisition and fluxes can structure the microbial communities, profoundly affect biosphere's features, as well as influence geochemistry. The iron cycle is closely coupled to carbon, sulfur, nitrogen, phosphorus and manganese cycles. Therefore, variation in the cycling of iron may be considered as an indicator of concurrent overall alteration in the biogeochemistry of the whole ecosystem. Since 2012 when the
previous Research Topic concerning iron cycling was published, the studies on iron cycle have undergone a revolution facilitated by a rapid technological development such as omic technology, stable isotope probing technologies and nanotechnology. Therefore, further research is needed to understand novel pathways for iron uptake and acquisition, gain insights into intracellular and extracellular iron mineralization, presence of microbially mediated iron cycling in natural and artificial environments, or advances in the analysis of the effect iron cycle has on other nutrient cycles; and gather evidence for the role of iron in the early biogeochemical evolution on Earth.
In this Research Topic, we will present the leading edge of iron microbiology research, focusing on dynamics of iron cycling in nature, geochemical significance of related microbial reactions and compounds, as well as potential application of this microbial process in biotechnology. Articles to be published in this Topic can include Original Research, Reviews, Technology Reports or Opinion papers.
Articles should address the following issues:
• Role of microorganisms in the iron cycle;
• Microbial iron metabolism;
• Omics of iron cycling microorganisms;
• Coupling cycle of iron and other elements;
• Interaction between microbes and iron;
• Mechanisms of bioleaching/biomineralization/biocorrosion and methods for environmental protection;
• Feammox and its applications.
