Fungus-initiated catalytic reactions at hyphal-mineral interfaces drive iron redox cycling and biomineralization. (1st September 2019)

• Record Type: Journal Article
• Authors: Yu, Guang-Hui; Chi, Zhi-Lai; Teng, H. Henry; Dong, Hai-Liang; Kappler, Andreas; Gillings, Michael R.; Polizzotto, Matthew L.; Liu, Cong-Qiang; Zhu, Yong-Guan
• Is Part Of: Geochimica et cosmochimica acta. Volume 260(2019)
• Page Start: 192
• Page End: 203
• Publication Date: 2019-09-01
• Subjects: Biocatalysis -- Fungi weathering -- Interfacial process -- Mineral dissolution -- Superoxides -- Synchrotron radiation; Geochemistry -- Periodicals; Meteorites -- Periodicals; Géochimie -- Périodiques; Météorites -- Périodiques; Geochemie; Astrochemie; Electronic journals; 551.905
• DOI: 10.1016/j.gca.2019.06.029
• Languages: English
• ISSNs: 0016-7037

Abstract

Abstract: The ability of fungi to weather a wide range of minerals influences plant nutrition and enhances global biogeochemical cycles of life-essential elements. The fungus-mineral interface plays a key role in weathering, but the specific mechanisms underlying these processes remain poorly understood. Here, we examined fungal-mineral weathering using hematite and Trichoderma guizhouense. We showed that hematite dissolution increased over cultivation time, with the formation of secondary minerals up to ∼3000 µm −2 at the interfaces after 66 h cultivation. Of the hematite associated with hyphae, approximately 15% was converted to the secondary mineral ferrihydrite. Importantly, superoxide radicals were detected at the hyphal tips and along the whole hyphae. During cultivation, a high concentration (∼1000 nM) of hydroxyl radical was also detected. Synchrotron radiation based spectromicroscopies at fungus-mineral interfaces suggest that fungus hyphae alter the local redox state of iron and thus are redox-active. These findings indicate that fungus-initiated catalytic reactions occur at hyphal-mineral interfaces, in view of the fact that superoxide does not diffuse far from the site of formation. Furthermore, these results also suggest that the catalytic reactions may serve as a new strategy for microbial iron uptake. Together, these findings constitute a significant step forward in understanding the ways that fungi make minerals available to biological systems.