Fungal Nanophase Particles Catalyze Iron Transformation for Oxidative Stress Removal and Iron Acquisition

Abstract

22Microbe-mineral interactions have shaped the surface of the Earth and impacted the evolution of 23 plants and animals. Although more than two-thirds of known mineral species have biological 24 imprints, how the biotransformation of minerals may have benefited microbial development, 25 beyond nutritional and energetic use, remains enigmatic. In this research, we have shown that biogenic ferrihydrite nanoparticles are extensively formed at the interface between an actively growing fungus and an iron-containing mineral, hematite. These biogenic nanoparticles formed through the fungus-hematite interactions can behave as mimetic catalysts, similar to nanozymes that imitate peroxidase which scavenges hydrogen peroxide for the mitigation of potential cytotoxicity. Evidence from various X-ray spectroscopic analyses indicated that non-lattice oxygen in the nanomaterials was chiefly responsible for this catalytic activity, rather than through the conventional mechanisms of iron redox chemistry. Cryo-scanning electron microscopy, high-resolution (~30 nm) 3D volume rendering, and biomass analyses further confirmed that the organism was active and capable of mediating the catalytic reactions. We therefore hypothesize that this confers an advantage to the organism in terms of protection from oxidative stress and ensuring the acquisition of essential iron. This work raises new questions about the roles of biogenic nanomaterials in the coevolution of the lithosphere and biosphere, and provides a step towards understanding the feedback pathways controlling the evolution of biogenic mineral formation. 40 41 42 KEYWORDS 43 4 microbe-mineral interactions, biomineralization, fungi, iron acquisition, nanoparticles, nanozymes, oxidative stress, surface oxygen anions, geomycology 45 nanoparticles were obtained from TEM imaging and particle-size distribution analysis using

Molybdenum Bioavailability and Asymbiotic Nitrogen Fixation in Soils are Raised by Iron (Oxyhydr)oxide-Mediated Free Radical Production

“…In addition, abundant redox-active minerals in soils can be a sink or a source of HO • , challenging the HO • analyses . In particular, nanosized minerals exhibit unexpected enzyme-like characteristics (named nanozymes), playing key roles in modulating HO • level when interacting with soil microorganisms. ,, Most recently, the content of hydroxyl radicals in soils was quantified by terephthalic acid (TPA) as a hydroxyl radical trapping agent . However, these common soil components will direct react with HO • and thus enlarge the uncertainty of HO • capture by TPA.…”

“…The AGW contained 0.11 mM MgCl 2 , 0.61 mM CaCl 2 , and 2 mM NaHCO 3 , 0.5 mM NH 4 Cl, 0.05 mM KH 2 PO 4 , 0.1 × of vitamin and trace element solutions and was supplemented with 11 mM Na-acetate, and 25 mM of hematite. Hematite was synthesized as previously described …”

Non-host plants: Are they mycorrhizal networks players?

“…Future studies using multi-omics and new technologies such as nanoscale secondary ion mass spectrometry (NanoSIMS) and cryo-scanning electron microscopy, to trace movement of C, N and P along mycorrhizal hyphae (e.g. Yu et al, 2020 ) would help to underpin such mechanisms. In addition, the function of mycorrhizas should be re-examined, particularly the non-nutritional benefits of mycorrhizas ( Albornoz et al., 2021 ).…”

Visualizing Mineral-Associated Organic Matters in Long-Term Fertilization Treated Soils by NanoSIMS and SR-FTIR

“…The analyses were performed with a NanoSIMS 50L (Cameca, Gennevilliers, France) at the School of Earth System Science, Tianjin University, China. Prior to the analysis, the gold coating layer (∼10 nm) and possible contamination of the sample surface were sputtered using a high primary beam current (pre-sputtering) (22). During the pre-sputtering step, the reactive Cs + ions were implanted into the sample to enhance the secondary ion yields.…”