利用EGSB反应器富集高纯度厌氧氨氧化菌

Enrichment of anaerobic ammonium oxidation bacteria by expanded-granular sludge bed reactor

摘要:

以储存60 d的ANAMMOX污泥为种泥，采用EGSB反应器富集高活性、高纯度的ANAMMOX菌富集培养物，考察反应器的脱氮能力，同时采用分子生物学方法鉴定培养前后ANAMMOX富集培养物中的优势菌种及ANAMMOX菌的相对丰度。在反应器运行的185 d中，最高氮负荷达3.0 kgN/(m3·d)，氨氮与亚硝酸盐氮的去除效率均大于85%。培养后ANAMMOX富集培养物中的优势菌种由待定荧光布罗卡地菌Candidatus Brocadia fulgid和待定巴西布罗卡地菌Candidatus Brocadia brasiliensis变为待定亚洲杰特氏菌Candidatus Jettenia asiatica。FISH结果表明ANAMMOX菌所占总细菌的相对丰度明显增加，由 (57.69±4.79)%提高到(83.32±4.40)%。定量PCR结果证实了培养后的富集培养物内ANAMMOX菌的拷贝数由1.14×1011拷贝/g湿重提高到3.69×1011拷贝/g湿重。

Abstract:

An expanded-granular sludge bed (EGSB) reactor was set-up with artificial water by seeding a 60–d stored ANAMMOX sludge. The nitrogen removal efficiency of ANAMMOX enrichment culture in the reactor was determined. In addition, the main microbial populations and the relative abundance of ANAMMOX bacteria were investigated by molecular approaches. Results show that the maximum nitrogen removal rate was 3.0 kg-N·m-3·d-1 after 185 d, and the ammonium and nitrite removal efficiencies were all over 85%. Analysis of 16S rRNA gene-cloning indicates that the main microbial population in the ANAMMOX enrichment culture was changed from Candidatus Brocadia fulgid and Candidatus Brocadia brasiliensis (0 day) to Candidatus Jettenia asiatica (185 day). Fluorescence in situ hybridization analysis shows that the relative abundance of ANAMMOX bacteria was increased from (57.69±4.79)% to (83.32±4.40)%. The results of qPCR further indicate that the gene copies of ANAMMOX bacteria in the granules were increased from 1.14×1011copies/g wet weight to 3.69×1011copies/g wet weight.