植物成長の燃料となるリンの解明(Unlocking phosphorus to fuel plant growth)

2025-03-04 ノースウェスタン大学

＜関連情報＞

• https://news.northwestern.edu/stories/2025/03/iron-oxides-act-as-natural-catalysts-to-unlock-phosphorus-to-fuel-plant-growth/
• https://pubs.acs.org/doi/10.1021/acs.est.4c12049
• https://tiisys.com/blog/2024/07/19/post-140873/

酸化鉄鉱物による酵素模倣リボヌクレオチド脱リン酸化の触媒パラメータの定量的ベンチマーク Quantitative Benchmarking of Catalytic Parameters for Enzyme-Mimetic Ribonucleotide Dephosphorylation by Iron Oxide Minerals

Jade J. Basinski,Sharon E. Bone,Aurore Niyitanga Manzi,Nasrin Naderi Beni,Fernando R. Tobias,Marcos Sanchez,Cynthia X. Cheng,Wiriya Thongsomboon,and Ludmilla Aristilde,
Environmental Science & Technology  Published: March 4, 2025
DOI:https://doi.org/10.1021/acs.est.4c12049

Abstract

Iron oxides, which are documented phosphorus (P) sinks as adsorbents, have been shown to catalyze organic P dephosphorylation, implicating these minerals as catalytic traps in P cycling. However, quantitative evaluation of this abiotic catalysis is lacking. Here, we investigated the dephosphorylation kinetics of eight ribonucleotides, with different nucleobase structures and P stoichiometry, reacting with common iron oxides. X-ray absorption spectroscopy determined that 0–98% of mineral-bound P was recycled inorganic P (P_i). Matrix-assisted laser desorption/ionization with mass spectrometry demonstrated short-lived triphosphorylated and monophosphorylated ribonucleotides bound to goethite. Based on Michaelis-Menten type modeling of the kinetic evolution of both dissolved and mineral-bound P_i, maximal P_i production rates from triphosphorylated ribonucleotides reacted with goethite (1.9–16.1 μmol P_i h^–1 g_goethite^–1) were >5-fold higher than with hematite and ferrihydrite; monophosphorylated ribonucleotides generated only mineral-bound P_i at similar rates (0.0–12.9 μmol P_i h^–1 g_mineral^–1) across minerals. No clear distinction was observed between purine-based and pyrimidine-based ribonucleotides. After normalization to mineral-dependent P_i binding capacity, resulting catalytic turnover rates implied surface chemistry-controlled reactivity. Ribonucleotide–mineral complexation mechanisms were identified with infrared spectroscopy and molecular modeling. We estimated iron oxide-catalyzed rates in soil (0.01–5.5 μmol P_i h^–1 g_soil) comparable to reported soil phosphatase rates, highlighting both minerals and enzymes as relevant catalysts in P cycling.