Wang Ping, Li Xiuting, Xiang Mufei, Zhai Qian
Department of Chemical and Environmental Engineering, Beijing Technology and Business University, Beijing 100037, PR China.
J Biosci Bioeng. 2007 Jun;103(6):563-7. doi: 10.1263/jbb.103.563.
By adopting two sequencing batch reactors (SBRs) A and B, nitrate as the substrate, and the intermittent aeration mode, activated sludge was domesticated to enrich aerobic denitrifiers. The pHs of reactor A were approximately 6.3 at DOs 2.2-6.1 mg/l for a carbon source of 720 mg/l COD; the pHs of reactor B were 6.8-7.8 at DOs 2.2-3.0 mg/l for a carbon source of 1500 mg/l COD. Both reactors maintained an influent nitrate concentration of 80 mg/l NO3- -N. When the total inorganic nitrogen (TIN) removal efficiency of both reactors reached 60%, aerobic denitrifier accumulation was regarded completed. By bromthymol blue (BTB) medium, 20 bacteria were isolated from the two SBRs and DNA samples of 8 of these 20 strains were amplified by PCR and processed for 16SrRNA sequencing. The obtained results were analysed by a Blast similarity search of the GenBank database, and constructing a phylogenetic tree for identification by comparison. The 8 bacteria were found to belong to the genera Pseudomonas, Delftia, Herbaspirillum and Comamonas. At present, no Delftia has been reported to be an aerobic denitrifier.
采用两个序批式反应器（SBR）A和B，以硝酸盐为底物，采用间歇曝气模式，对活性污泥进行驯化以富集好氧反硝化菌。对于碳源为720mg/l COD、溶解氧（DO）为2.2 - 6.1mg/l的情况，反应器A的pH值约为6.3；对于碳源为1500mg/l COD、DO为2.2 - 3.0mg/l的情况，反应器B的pH值为6.8 - 7.8。两个反应器的进水硝酸盐浓度均保持在80mg/l NO₃⁻ - N。当两个反应器的总无机氮（TIN）去除效率达到60%时，认为好氧反硝化菌的富集完成。通过溴百里酚蓝（BTB）培养基，从两个SBR中分离出20株细菌，并对这20株中的8株进行PCR扩增DNA样本，然后进行16SrRNA测序。通过GenBank数据库的Blast相似性搜索对所得结果进行分析，并构建系统发育树以进行比较鉴定。发现这8株细菌属于假单胞菌属、代尔夫特菌属、草螺菌属和丛毛单胞菌属。目前，尚未有报道称代尔夫特菌属是好氧反硝化菌。
