利用PCR-DGGE分析有机物对厌氧氨氧化菌群的影响

Analysis of the Effects of Organics on Anammox Microbial Community by PCR-DGGE

为了研究有机物对Anammox菌群的影响,以及微生物与脱氮的关系,为工艺改进提供依据。使用SBR厌氧氨氧化反应器,从反应器不同TOC/NH_4^+-N阶段采集活性污泥样品,利用聚合酶链式反应—变性梯度凝胶电泳(PCR-DGGE)技术,分析了样品中微生物种群结构。结果表明反应器中主要微生物包含变形菌门(Proteobacteria)、浮霉菌门(Planctomycetes)、厚壁菌门(Firmicutes)和绿菌门(Chlorobi);其中变形菌门(β-变形菌和γ-变形菌)为优势菌群。TOC/NH_4^+-N从0逐渐增加至2.0的过程中,反应器中的反硝化菌(变形菌门)不断增长,Anammox菌群在TOC/NH_4^+-N为0.4阶段得到最大程度的富集,此时反应器内部微生物多样性也最高;随着有机物含量增加,Anammox菌生长受到严重抑制,反应器微生物物种多样性也逐渐下降。荧光定量(qPCR)分析表明Anammox菌含量从1.30×10^(11) copies/mL下降至3.18×10~9 copies/mL,而DB含量从1.57×10~9copies/mL增加至3.74×10^(10) copies/mL。说明随着C/N的增加,反应器脱氮能力逐渐从Anammox过渡到反硝化过程。通过测定反应器内壁附着污泥,还发现其微生物丰度和含量均高于同时期反应器内部活性污泥样品,推测厌氧微生物菌群更适宜在静态基质生长。

The purpose of the research was to study the effect of organics on anammox microbial community and the relationship between microbes and denitrification in order to provide basis for technique improvement. Activated sludge samples were collected from different TOC/NH4+-N stages in anammox sequencing batch reactor(SBR) and the microbial population structures were analyzed by polymerase chain reaction-denature gradient gel electrophoresis(PCR-DGGE) technology. The results indicated that the main microorganisms in the reactor included Proteobacteria,Planctomycetes, Firmicutes and Chlorobi. Among them, Proteobacteria(β-proteobacteria and γ-proteobacteria)was the dominant flora. With the increase of TOC/NH4+-N from 0 to 2.0, the denitrifying bacteria(Proteobacteria)proliferated continuously while the anammox flora reached its maximum concentration at 0.4 TOC/NH4+-N stage in which the reactor had the greatest diversity. With the increase of organic content, the growth of anammox bacteria was severely suppressed and the microbial species diversity of the reactor declined gradually. q PCR analysis showed that the content of anammox bacteria declined from 1.30×10^11 copies/mL to 3.18×10^9 copies/m L while the content of the DB increased from 1.57×10^9 copies/m L to 3.74×10^10 copies/m L. This indicated that the denitrification capacity of the SBR reactor gradually transited from anammox to denitrification with the increase of C/N. By determining the attached sludge in the inner wall of the reactor, it was also found that its microbial abundance and content were higher than those in the reactor-inside activated samples inside the reactor of the same period. It was inferred that the anaerobic microbial flora was more suitable for growth in the static substrate.