Abstract:

Based on the view about removal of sulfur by denitrifying，for which the bacteria was enriched in a continuous stirred reactor，and the functional bacteria was monitored and identified by plate count and PCR-DGGE methods. The single strain SNB1 obtained by isolation and purification of bacteria was also identified. In the reactor， the amount of bacteria for total，desulfurization and denitrifying increased by 1.92×10，6.49×10⁵，1.66×10³-fold. There are three dominant microorganisms in the reactor during stable operation. a，a flora and Thauera sp. homology up to 99.0%，and it is a kind of denitrifying bacteria. The physiological and biochemical characteristics of the SNB1 contained revealed that it is a kind of facultative autotrophic bacteria and has the 99.0% homology with Thauera selenatis. The ratio and amount of desulfurization bacteria are 49.3% and 3.70×10⁹ cfu•ml^-1.b，the homology of another flora with Desulfovibrio sp. is higher than 98%，it is sulphate-reducing bacteria. c，the homology of third flora with Rhodococcus sp. is higher than 94%，it is denitrifying bacteria. When S/N is in the range of 0.007—0.386，100% S^2- and 46.47% SO^2-₄ are converted into S⁰. The removal efficiency of NO^-₃ and COD are 72.3%—95.8% and 9.8%—43.5%，respectively.

Key words:

短程除硫, 反硝化除硫菌, 功能菌群变化, PCR-DGGE

摘要：

依据反硝化除硫理论，利用全混流反应器富集反硝化除硫菌，采用平板计数法和PCR-DGGE法对功能菌群进行跟踪和鉴定，并对分离纯化得到的单菌株SNB1进行鉴定。结果表明，反应器中细菌总量、除硫菌和反硝化菌分别增加了1.92×10、6.49×10⁵和1.66×10³倍。稳定运行时反应器内存在3种优势菌群。a菌群与Thauera sp. 的同源性高达99%，为反硝化菌；其包含的SNB1生理生化指标显示为一株兼性自养反硝化除硫菌，且与Thauera selenatis（同源性高达99. 0%）最相似；反硝化除硫菌的比例为49.3%，数量约为3.70×10⁹ cfu•ml^-1。b菌群与Desulfovibrio sp. 的同源性高于98%，为硫酸盐还原菌。c菌群和Rhodococcus sp. 的同源性高于94%，为反硝化菌。当S/N在0.007～0.386间变化时，除S^2-始终被100%转化为S⁰外，还有大于46.47%的SO^2-₄-S被转化为S⁰；而NO^-₃和COD的去除率分别为72.3%～95.8%和9.8%～43.5%。

关键词:

短程除硫, 反硝化除硫菌, 功能菌群变化, PCR-DGGE