硫酸盐还原反应器污泥驯化过程中微生物群落变化分析

采用PCR-DGGE技术,对硫酸盐还原反应器UASB污泥驯化过程中微生物群落的变化进行了分析.结果表明,污泥驯化过程中,微生物群落生物多样性与反应器硫酸盐及COD去除率呈明显的正相关,微生物群落Shannon指数大于3.45时,反应器硫酸盐去除率稳定在95%左右;对DGGE图谱中优势条带进行回收克隆并测序表明,污泥中微生物群落主要包含Firmicutes、Proteobacteria、Deinococcus-Thermus和Chloroflexi这4大类群,分别占总数的50.0%、28.6%、14.3%和7.1%;其中厌氧发酵细菌Clostridium sp.在驯化全过程中均占优势,但优势菌群的种类发生变化;厌氧细菌Chloroflexi sp.、Geopsychrobacter sp.等在污泥驯化过程中曾成为优势菌群但之后消亡;厌氧细菌Geobacter sp.则在污泥驯化过程中逐渐成为优势菌群;Desulfovibrio sp.在污泥驯化的最后2个阶段成为优势菌.

Analysis of Microbial Community Variation in the Domestication Process of Sludge in a Sulfate-reducing Reactor

The variations of microbial community in the sludge of sulfate-reducing UASB during domestication period were analyzed by PCR-DGGE technique. The results showed that the diversity of microbial community was strongly related to the sulfate reduction and COD removal performance. The sulfate reduction rate of the reactor was about 95% when the Shannon index of microbial community was higher than 3.45. The preponderant bands in DGGE figure were excised and cloned, and the sequencing analysis indicated there were Firmicutes, Proteobacteria, Deinococcus-Thermus and Chloroflexi in the sludge, which accounted for 50.0%, 28.6%, 14.3% and 7.1% of the total sequences of samples, respectively. The anaerobic fermentative bacteria of Clostridium sp. were predominant in the whole domestication period, but the predominant species was changing. Some anaerobic bacteria like Chloroflexi sp. and Geopsychrobacter sp. were detected to be dominant species, which then disappeared along with further domestication, but anaerobic bacteria Geobacter sp. became gradually predominant in the domestication process. Species of Desulfovibrio sp. were detected to be predominant only in the last two phases of domestication.