Correlation of functional instability and community dynamics in denitrifying dispersed-growth reactors
Correlation of functional instability and community dynamics in denitrifying dispersed-growth reactors
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DOI：
10.1128/aem.01519-06
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发表时间：
2007-02-01
影响因子：
4.4
通讯作者：
Criddle, C. S.
中科院分区：
文献类型：
--
作者：
Gentile, M. E.;Jessup, C. M.;Criddle, C. S.
了解微生物群落动态和功能不稳定性之间的关系是设计可靠的生物水处理系统的重要一步。在这项研究中，社区动态的两个分散生长的生物反应器进行了检查期间的功能稳定和不稳定。在这两个反应器的功能不稳定期间，随着时间的推移，废水的化学变化，高硝酸盐浓度的时期，其次是波动的亚硝酸盐浓度的时期。通过16 S rRNA基因的克隆文库分析来检查群落结构。群落动态进行了调查与末端限制性片段（T-RF）长度多态性，并通过硝酸盐还原试验的代表菌株的T-RF所代表的功能多样性进行了评估。在功能不稳定期间，群落结构发生了很大的变化，其动态与出水化学成分相关性显著。亚硝酸盐浓度显着相关的硝酸盐还原Delftia和无色杆菌样T-RFs的相对丰度。代表Acidovorax样T-RF的分离物在分批测定中将硝酸盐直接还原为氮，而没有任何中间体的积累。类食酸菌T-RF相对丰度与亚硝酸盐浓度呈显著负相关，表明其与良好的功能性能相关。本研究的结果揭示了一个明确的社区动态和功能不稳定性之间的关系和多样性的重要性，减少人口中的一个mitrate-reducing社区。
Understanding the relationship between microbial community dynamics and functional instability is an important step towards designing reliable biological water treatment systems. In this study, the community dynamics of two dispersed-growth denitrifying reactors were examined during periods of functional stability and instability. In both reactors during the period of functional instability, the effluent chemistry changed over time, with periods of high nitrate concentrations followed by periods of fluctuating nitrite concentrations. Community structure was examined by clone library analysis of the 16S rRNA gene. Community dynamics were investigated with terminal restriction fragment (T-RF) length polymorphism, and the functional diversity represented by T-RFs was assessed through nitrate reduction assays of representative isolates. During the period of functional instability, the community structure changed considerably, and the dynamics correlated significantly with effluent chemistry. The nitrite concentration was significantly correlated with the relative abundances of the nitrate-reducing Delftia- and Achromobacter-like T-RFs. The isolate representing the Acidovorax-like T-RF reduced nitrate directly to nitrogen in batch assays without the accumulation of any intermediates. The Acidovorax-like T-RF relative abundance was significantly negatively correlated with nitrite concentration, indicating that it was associated with good functional performance. The results of this study reveal a clear relationship between community dynamics and functional instability and the importance of diversity among mitrate-reducing populations within a denitrifying community.