基于高通量测序的OMS-2对序批式反应器系统微生物群落的影响

Effect of OMS-2 on microbial community of SBR system through high-throughput sequencing

随着纳米材料的广泛应用,越来越多的纳米材料随着废水进入污水处理厂,纳米材料对污水生物处理系统的潜在影响越来越受到重视。探讨了氧化锰八面体分子筛(manganese oxide octahedral molecular sieve,OMS-2)纳米颗粒对序批式反应器(sequencing batch reactor,SBR)中活性污泥微生物群落结构的影响;以活性艳红X-3B溶液模拟印染废水,将不同浓度的OMS-2混入稳定运行的SBR中,采用Illumina MiSeq高通量测序分析技术,对不同SBR中微生物分布规律进行了研究。结果表明:SBR添加0.25 g·L^-1的OMS-2后,其COD去除率和脱色率分别提升了6%和13.6%;Illumina MiSeq高通量测序显示,在混入0.25 g·L^-1的OMS-2后,SBR内污泥菌群中拟杆菌门(Bacteroidetes)和变形菌门(Proteobacteria)的微生物DNA序列操作分类单元(operational taxonomic units,OTU)分别增加了16.8%和96.4%,这2类菌种可能提升了SBR降解有机污染物的能力;不同浓度的OMS-2改变了菌群的多样性和结构,低浓度的OMS-2可以提升微生物菌群的多样性和改变菌群的结构。X射线光电子能谱(XPS)分析表明,OMS-2在SBR中存在锰(Ⅳ)/锰(Ⅲ)转变为锰(Ⅱ)的氧化还原反应,该过程可能影响了菌群的组成。研究为纳米材料的实际应用和环境风险提供了参考。

With widely using of the nano-particles,more and more nano-particles have entered the sewage treatment plant with wastewater,and more and more attentions have been paid to the potential impact of nanoparticles on sewage biological treatment system.In this study,the effects of nano manganese oxide octahedral molecular sieve(OMS-2)nanoparticles on the microbial community in activated sludge of sequencing batch reactor(SBR).The dyeing and printing wastewater was simulated by X-3B,and different dosages of nano OMS-2 were added into SBR.The microbial distribution rules in different SBRs were studied by the Illumina MiSeq high-throughput sequencing of 16 S rRNA gene.Results showed that the COD removal and decolorization increased by 6% and 13.6%,respectively,at OMS-2 dosage of 0.25 g·L^-1 in the SBR,and the OTU of Bacteroidetes and Proteobacteria increased by 16.8% and 96.4%,respectively,based on the Illumina MiSeq high-throughput sequencing of 16S rRNA gene,and these two types of microorganisms could enhance the ability of organic pollutants degradation by SBR.Moreover,the small dosage of nano OMS-2 could enhance the microbial diversity and alter the community structure.The X-ray photoelectron spectroscopy illustrated that the redox reaction of Mn(Ⅳ)/Mn(Ⅲ)to Mn(Ⅱ)in nano OMS-2 occurred in the SBR,and in turn affected the microbial community.This study provides innovative ideas for the practical application of nano-particles and their environmental risks assesment.