厌氧氨氧化污泥中效应菌的分子生物学研究

Molecule biology study on the effective bacteria in ANAMMOX sludge

对具有厌氧氨氧化作用的细菌进行更深入的分析和了解有助于该新型生物脱氮过程在实践中的应用,采用分子生物学方法从已培养的具有厌氧氨氧化活性的污泥中提取细菌总DNA ,经纯化、特异引物PCR扩增、克隆、测序等过程,得到厌氧氨氧化菌部分16SrDNA序列(长度为836bp) ,少部分克隆具有1～2个碱基的突变。此外,进化分析结果显示培养获得的细菌与已发现的CandidatusBrocadiaanammoxidans、Anaerobicammonium oxidizingPlancto mycete、UnculturedanoxicsludgebacteriumKU1细菌在进化上关系较近,但比对分析结果表明所研究的细菌与上述细菌的DNA序列相似度不高,这表明自然环境中还存在一种以前未被发现的可进行厌氧氨氧化的细菌。

A greater understanding of anaerobic ammonium oxidation bacteria will help to pave the way for the new biological nitrogen removal process application in practice. To this end, this study used molecule biology methods. Crude DNA of the total bacteria in a cultivated sludge with ANAMMOX capability was extracted and purified. Then PCR amplification using specific primers, clone and sequencing processes were performed. The partial 16S rDNA sequence of cultivated ANAMMOX bacteria is 836bp. Some clones have one to two base mutation(s). Phylogenetic analysis indicates that the cultivated ANAMMOX bacteria in this study close toCandidatus Brocadia anammoxidans, anaerobic ammonium-oxidizingPlanctomycete and uncultured anoxic sludge bacterium KU1 with the same function, whereas the cultivated ANAMMOX bacteria are relatively low DNA sequence similarity to the forementioned bacteria using alignment analysis. The results suggest that there is a kind of bacterium which has never been found before with ANAMMOX capability existing in nature.