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厌氧氨氧化作为一种异于反硝化的氮转化途径,可同时将氨氮与亚硝氮转化为氮气,是沉积环境中重要的脱氮过程.本文基于15N同位素配对技术,利用15NH+4、15NH+4+14NO-3和15NO-3三组同位素开展泥浆培养试验,研究了四季太湖西部湖区沉积物厌氧氨氧化潜在速率及其脱氮贡献率;结合厌氧氨氧化功能基因丰度及沉积物理化特征,探讨了沉积物厌氧氨氧化潜在速率季节性差异的成因.研究结果表明:沉积物厌氧氨氧化潜在速率存在显著的季节差异性,夏、秋季显著高于春、冬季,秋季最高,为10.11μmol·kg-1·h-1(以N2计,下同),冬季最低,为3.24μmol·kg-1·h-1;沉积物总脱氮速率为10.67~31.02μmol·kg-1·h-1,其中厌氧氨氧化脱氮效应显著,四季脱氮贡献率高达30%~40%.有机质、氨氮及其功能基因丰度是影响厌氧氨氧化潜在速率的重要因子,研究区域沉积物孔隙水夏、秋季氨氮浓度和厌氧氨氧化功能基因丰度均高于春、冬季,沉积物有机质含量低于春、冬季,厌氧氨氧化潜在速率随沉积物孔隙水氨氮及其功能基因丰度升高而升高,随沉积物有机质升高而降低.
As an alternative to denitrification, anaerobic ammonium oxidation can simultaneously convert ammonia nitrogen and nitrite nitrogen into nitrogen, which is an important denitrification process in sedimentary environment.Based on the 15N isotope pairing technique and using 15NH + 4, 15NH + 4 + 14NO-3 and 15NO-3 three groups of isotopes to carry out mud culture experiments to study the seasons Taihu Lake sediment anaerobic ammonia oxidation potential rate and the contribution rate of denitrification; combined anaerobic ammonia oxidation gene abundance and Sedimentary physical and chemical characteristics of the sediment anaerobic ammonia oxidation potential seasonal differences in the study of the results show that: sediment anaerobic ammonia oxidation potential rate of significant seasonal differences in summer and autumn was significantly higher than the spring and winter, The highest in autumn was 10.11μmol · kg-1 · h-1 (calculated by N2, the same below) and the lowest in winter was 3.24μmol · kg-1 · h-1. The total denitrification rate of sediment was 10.67 ~ 31.02μmol · kg-1 · h-1, of which anaerobic ammonium oxidation significantly, the contribution of the four seasons denitrification as high as 30% to 40% .Amount of organic matter, ammonia nitrogen and its abundance of functional genes is an important factor affecting the potential rate of anaerobic ammonium oxidation , To study the sediment pore water summer, autumn ammonia concentration and anammox power The abundance of gene could be higher than that in spring and winter, and the content of organic matter in sediment was lower than that in spring and winter. The potential rate of anaerobic ammonium oxidation increased with the increase of ammonia nitrogen and its functional gene abundance in pore water of sediment. High and lower.