| 河蚬（Corbicula fluminea）扰动对表层沉积物中氨氧化菌群落结构和丰度的影响 |
| 摘要点击 2499 全文点击 1345 投稿时间：2013-10-18 修订日期：2013-12-26 |
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| 中文关键词 河蚬 生物扰动 氨氧化细菌 氨氧化古菌 群落结构和丰度 |
| 英文关键词 Corbicula fluminea bioturbation ammonia-oxidizing bacteria ammonia-oxidizing archaea community composition and abundance |
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| 中文摘要 |
| 为研究不同生物量河蚬（Corbicula fluminea）的生物扰动对表层沉积物中氨氧化菌群落结构和丰度的影响，本研究设计了沉积物-水微宇宙的模拟体系，通过构建克隆文库、实时荧光定量PCR（real-time qPCR）等分子生物学方法比较不同密度河蚬扰动的沉积物中氨氧化古菌（ammonia-oxidizing archaea，AOA）和氨氧化细菌（ammonia-oxidizing bacteria，AOB）群落结构和丰度差异. 结果表明，河蚬的生物扰动作用对表层沉积物氮素释放有明显的促进作用. 氨氧化菌（AOA和AOB）amoA基因克隆文库中，AOA的amoA基因序列包含了已知的海洋和土壤环境中的两个分支，AOB的amoA基因绝大部分序列都属于变形菌门β亚纲（β-Proteobacteria）中的亚硝化单细胞菌属（Nitrosomonas）. 3个处理组表层沉积物中细菌amoA基因丰度均高于古菌amoA基因丰度，且河蚬密度越高则细菌amoA的丰度越低. 同时，河蚬的添加使得微宇宙体系中氨氧化菌（AOA和AOB）的多样性降低. 综上，河蚬的生物扰动对表层沉积物中氨氧化菌群落结构和丰度产生了一定的影响. |
| 英文摘要 |
| To better understand the effects of Corbicula fluminea bioturbation on the ammonia-oxidizing microorganisms in the surface sediment, sediment-water microcosms with different densities of Corbicula fluminea were constructed. Clone libraries and real-time qPCR were applied to analyze the community composition and abundance of ammonia-oxidizing archaea (AOA) and bacteria (AOB) in the surface sediments. The results obtained indicated that the bioturbation of Corbicula fluminea accelerated the release of nitrogen from the surface sediment. In the amoA gene clone libraries, the identified AOA amoA gene sequences affiliated with the two known clusters (marine and soil clusters). The identified AOB amoA gene sequences mostly belonged to the Nitrosomonas of β-Proteobacteria. The abundance of the bacterial amoA gene was higher than that of the archaeal amoA gene in all treatments. With increasing density of Corbicula fluminea, decreased abundances of the bacterial amoA gene were observed. At the same time, the diversity of AOA and AOB reduced in the Corbicula fluminea containing microcosms. In conclusion, the bioturbation of Corbicula fluminea could affected the community composition and abundance of ammonia-oxidizing microorganisms in surface sediments. |
