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Intrinsic enzyme-like activity of magnetite particles is enhanced by cultivation with Trichoderma guizhouense |
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| Authors: | Zhi-Lai Chi Xiang-Yang Zhao Ya-Ling Chen Jia-Long Hao Guang-Hui Yu Bernard A Goodman Geoffrey Michael Gadd |
| Institution: | 1. Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, College of Resource & Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095 China
Z.L.C. and X.Y.Z. contributed equally to this work.;2. Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, College of Resource & Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095 China Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin, 300072 China;3. Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, 100029 China;4. Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, College of Resource & Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095 China;5. College of Physical Science and Technology, Guangxi University, Nanning, 530004 China;6. Geomicrobiology Group, School of Life Sciences, University of Dundee, Dundee, DD1 5EH UK |
| Abstract: | Fungal–mineral interactions can produce large amounts of biogenic nano-size (~ 1–100 nm) minerals, yet their influence on fungal physiology and growth remains largely unexplored. Using Trichoderma guizhouense NJAU4742 and magnetite (Mt) as a model fungus and mineral system, we have shown for the first time that biogenic Mt nanoparticles formed during fungal–mineral cultivation exhibit intrinsic peroxidase-like activity. Specifically, the average peroxidase-like activity of Mt nanoparticles after 72 h cultivation was ~ 2.4 times higher than that of the original Mt. Evidence from high resolution X-ray photoelectron spectroscopy analyses indicated that the unique properties of magnetite nanoparticles largely stemmed from their high proportion of surface non-lattice oxygen, through occupying surface oxygen-vacant sites, rather than Fe redox chemistry, which challenges conventional Fenton reaction theories that assume iron to be the sole redox-active centre. Nanoscale secondary ion mass spectrometry with a resolution down to 50 nm demonstrated that a thin (< 1 μm) oxygen-film was present on the surface of fungal hyphae. Furthermore, synchrotron radiation-based micro-FTIR spectra revealed that surface oxygen groups corresponded mainly to organic OH, mineral OH and carbonyl groups. Together, these findings highlight an important, but unrecognized, catalytic activity of mineral nanoparticles produced by fungal–mineral interactions and contribute substantially to our understanding of mineral nanoparticles in natural ecosystems. |
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