【摘要】 采用逆转录实时荧光定量PCR技术,分析了春季东海表层沉积物中氨氧化微生物amoA基因表达水平的空间分布特征;并通过培养实验,探究了沉积物中活性氨氧化细菌（ammonia-oxidizing bacteria,AOB）及氨氧化古菌（ammonia-oxidizing archaea,AOA）对硝化潜势和N₂O生成的相对贡献.结果显示,表层沉积物中AOA amoA基因表达水平（4.49×10²～2.17×10⁶copies/g）显著高于AOB（6.60×10¹～7.65×10⁵copies/g）,二者的amoA基因表达水平均表现出近岸低（AOA:8.92×10⁵copies/g;AOB:2.06×10³copies/g）、远岸高（AOA:1.05×10⁶copies/g;AOB:4.06×10⁴copies/g）的空间分布特征;近岸沉积物的硝化潜势高于远岸;从近岸到远岸,硝化过程由AOA主导逐渐转变为AOB主导.在N₂O生成过程中,NH₄⁺的添加能显著促进N₂O的生成;相对于AOA,AOB在N₂O生成过程中发挥着更加重要的作用.更多还原

【Abstract】 This study utilized reverse transcription quantitative real-time PCR to investigate the spatial distribution of amo A gene expression levels among ammonia-oxidizing microorganisms in the surface sediments of the East China Sea during spring.Cultivation experiments were performed to assess the relative contributions of ammonia-oxidizing bacteria （AOB） and ammonia-oxidizing archaea （AOA） to the nitrification potential and N₂O production in the surface sediments.The results revealed that the expression level of AOA amo A gene was significantly higher than that of AOB （AOA:4.49×10²～2.17×10⁶copies/g;AOB:6.60×10¹～7.65×10⁵copies/g）,with both showing a spatial distribution pattern of lower levels in nearshore areas （AOA:8.92×10⁵copies/g;AOB:2.06×10³copies/g） and higher in offshore areas （AOA:1.05×10⁶copies/g;AOB:4.06×10⁴copies/g）.Nitrification potential was found to be higher in nearshore sediments than in offshore sediments,with the nitrification process gradually shifting from AOA dominance in nearshore areas to AOB dominance in offshore areas.In the N₂O production process,the addition of NH₄⁺significantly enhanced N₂O production,with AOB playing a more critical role than AOA in this process.更多还原