喹啉与吲哚驯化的反硝化反应器的微生物群落结构分析比较

Comparison of microbial community structure of quinoline and indole acclimated denitrifying bioreactor

摘要:

【目的】本研究旨在比较分析分别以喹啉和吲哚为底物, 在相同条件下驯化的两个反硝化生物反应器的微生物群落结构。【方法】采用相同的种子污泥和相同的驯化条件, 经过大约6周的驯化后, 两个反应器均达到稳定而高效的污染物去除能力, 通过16S rDNA克隆文库技术对两个反应器的微生物群落结构进行研究。【结果】研究发现, 微生物群落结构表现出很大的差异。喹啉驯化的群落中所有的OTU都属于Betaproteobacteria, 而吲哚驯化的群落中Betaproteobacteria占56.3%, 吲哚驯化的群落具有更高的多样性。两个群落的优势OTU也不同, 喹啉驯化群落中Thauera及其它Rhodocyclaceae科的微生物占整个群落的73%, 而吲哚驯化群落中优势OTU为Comamonadaceae科、Alcaligenaceae科和Rhodocyclaceae科等类型的微生物, 其中Comamonadaceae科的一个OTU占整个群落的28.7%。【结论】不同的驯化底物对微生物群落的组成具有较强的选择作用。首次报道并比较了可高效降解喹啉和吲哚的反硝化生物反应器的微生物群落结构。

Abstract:

[Objective] We compared the microbial communities of two denitrifying bioreactors acclimated by quinoline and indole under identical condition. [Methods] We acclimated two reactors by using the same seeding sludge and acclimating conditions. When both reactors reached steady stage with a high pollutant removal capacity after 6 weeks adaptation, we constructed the 16S rDNA clone libraries to analyze the structure of microbial communities of those 2 bioreactors. [Results] Despite the same seeding sludge and identical acclimating condition, molecular ecological analysis showed distinctly different communities of two reactors. All operational taxonomic units (OTUs) of 16S rDNA clone library of quinoline acclimated bioreactor were affiliated to Betapro-teobacteria, whereas in library of indole acclimated bioreactor, the percentage of Betaproteobacteria was only 56.3%. Results showed that microbial diversity in indole acclimated community was higher. Clones (73%) in quinoline acclimated community were Thauera related OTUs from the Rhodocyclaceae family. But OTUs from the families of Comamonadaceae, Alcaligenaceae and Rhodocyclaceae were dominant OTUs in indole acclimated community. The most dominant OTU from Comamonadaceae was 28.7％ in clone library. [Conclusion] The type of pollutants in the wastewater had a strong effect on the selection of population in microbial community. Our study was the first report comparing the microbial structure of two effective denitrifying communities which could efficiently degrade quinoline and indole.