T134 New Advances in Geobiology

Monday, 16 October 2023
1:30 PM - 5:30 PM
325

THE INHIBITION EFFECT OF ZN ON FUNGAL MN OXIDATION

Paper number: T134-14
Program: Technical Sessions
Time: 4:45 PM – 5:00 PM

Authors

  • Wei Ren Presenting Author
    Oklahoma State University, Stillwater, OK
  • Wei Ren Presenting Author
    Northwestern A&F University, Yangling
  • Tingying Xu
    Oklahoma State University, Stillwater, OK
  • Ming Tang
    South China Agricultural University, Guangzhou

Abstract

Manganese (Mn) oxides are ubiquitous minerals that commonly control the uptake and release of metals and nutrients and have great potential for metal contaminant remediation. In nature, the oxidation of Mn(II)aq to form the sparingly soluble, nanocrystalline Mn(III/IV) oxides is largely driven by microbial activities through enzymatic and metabolite-mediated pathways. In metal-polluted sites, co-contamination with other metals besides Mn is common. The presence of these additional metals can easily impact the microbial enzymatic and metabolite-mediated pathways, leading to reduced efficiency in removing the metal contaminants by biogenic Mn oxides.

Zinc (Zn) is a widespread co-contaminant commonly found in natural metal-impacted sites. It is an essential element for living organisms but can harm animals and humans at high concentrations. Our previous results have shown that Zn inhibited the formation of Mn oxides without affecting the growth of fungus (a new filament Ascomycota fungus Curvularia lunata TC1). This fungus was isolated from the wastewater at Tar Creek superfund site located in northeast Oklahoma. We have investigated the rate of Mn oxide production by measuring the residual Mn(II) in solution using ICP-OES. Our findings indicated that our fungus was capable of oxidizing 200 µM Mn(II) within 14 days and the presence of a high concentration of Zn (80 µM) inhibited the formation of Mn oxides. This study aims to elucidate the detailed pathway of Zn inhibition of Mn oxidation mediated by fungus TC1. Since Zn participates in lots of biological activities, we assume that Zn may inhibit the activities of specific Mn oxidation-related enzymes in our fungus.

To confirm our hypothesis, we cultivated our fungus in AY media with various amounts of Mn/Zn and collected hyphae at 5 days to identify Mn oxidation-related enzymes. We are conducting transcriptomics analysis using Illumina NovaSeq to find the differentially expressed genes and conducting proteomics analysis using LC/MS/MS to identify Mn oxidation-related enzymes. Results from this study will reveal the pathway of fungus TC1 easily affected by Zn and may provide new insight into the process of biogenic Mn oxidation.

Geological Society of America Abstracts with Programs. Vol. 55, No. 6

doi: 10.1130/abs/2023AM-391423

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