作者：Yuan, H., Guan, T., Yuan, Q., Zeng, Q., Yu, J., Cai, Y., Liu, E., Li, Q. & Wang, Y.

Organic phosphorus (Po) mineralization is a major internal source of soluble reactive phosphorus (SRP) in lakes, yet the molecular and microbial mechanisms governing this transformation remain poorly understood. Here, we aim to elucidate these mechanisms by integrating excitation-emission fluorescence spectroscopy, Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS), and metagenomics across two contrasting ecological niches in Taihu Lake, namely the Cyanophyta-dominated and macrophyte-dominated regions. We also supplement our results with the findings from a global meta-analysis. We found that fulvic-associated Po (Fu-Po) dominated sedimentary Po inventories, whereas Po extracted with NaHCO3 (NaHCO3-Po) and microbial biomass Po (biomass-Po) exhibited higher decomposition potential. Fluorescence indices indicated increasing lability with depth, and humic-like materials exhibited a higher tendency to be decomposed under anoxia, accompanied by the accumulation of fulvic-like fractions. FT-ICR-MS revealed proteins and lignins as key constituents of humic-associated Po and Fu-Po, supporting their bioavailability, while NaHCO3-Po was enriched in compounds with lipid-like CHOSP formulas, suggesting greater lability. Metagenomics identified phoD as the most abundant phosphatase-encoding gene, with rare but highly connected phoD-harboring taxa emerging as potential keystone regulators alongside abundant functional groups. Across global lake sediments, alkaline phosphatase activity, Po content, and phoD abundance were found to covary positively, and structural equation modeling highlighted Fu-Po as a disproportionate indirect driver of SRP replenishment via phoD-mediated phosphatase activity. These findings reveal a mechanistic cascade linking molecular composition to phoD-mediated enzymatic potential in Po mineralization, identifying Po bioavailability, rather than inorganic phosphorus pools alone, as a critical driver for reducing internal loading. Targeting this pathway could modulate Po mineralization mechanisms in sediments worldwide, offering valuable insights into the management of lake eutrophication under accelerating nutrient pressures.

有机磷（Po）矿化是湖泊中可溶性活性磷（SRP）的重要内源，但控制这一转化的分子与微生物机制仍知之甚少。本研究结合三维激发—发射荧光光谱、傅里叶变换离子回旋共振质谱（FT-ICR-MS）与宏基因组学，以太湖两种生态位迥异的区域——蓝藻主导区与沉水植物（大型水生植物）主导区——为对象，旨在阐明上述机制，并以全球荟萃分析的结果加以补充。发现：富里酸结合态Po（Fu-Po）在沉积物Po库中占主导，而NaHCO₃提取态Po（NaHCO₃-Po）与微生物量Po（biomass-Po）则表现出更高的分解潜势。荧光指标显示，Po的不稳定性（可分解性）随深度增加而升高；类腐殖质物质在缺氧条件下更易被分解，并伴随类富里酸组分的累积。FT-ICR-MS分析表明，蛋白质与木质素类化合物是腐殖质结合态Po与Fu-Po的关键组分，支持其生物有效性；而NaHCO₃-Po中富含脂质类CHOSP分子式的化合物，提示其更强的可分解性。宏基因组分析表明，phoD 是丰度最高的磷酸酶编码基因；携带 phoD 的稀有类群虽丰度低但连接度极高，与优势功能类群一同构成潜在的“关键种”调节者。在全球湖泊沉积物中，碱性磷酸酶活性、Po含量与 phoD 丰度呈显著正协变；结构方程模型进一步表明，Fu-Po是通过 phoD 介导的磷酸酶活性补充SRP的不成比例的间接驱动因素。这些发现揭示了“分子组成 → phoD 介导的酶学潜势”的Po矿化机制级联，指出Po的生物有效性——而不仅仅是无机磷库——是削减内源负荷的关键驱动因素。针对这一途径进行调控，有望调节全球湖泊沉积物的Po矿化机制，为营养盐压力不断加剧背景下的湖泊富营养化管理提供重要启示。

（来源：Environmental Science & Technology 2026 Issue 14  DOI: 10.1021/acs.est.5c15353）