好氧反硝化菌株的鉴定及其反硝化特性研究

Identification and Characterization of a Bacterial Strain C3 Capable of Aerobic Denitrification

从活性污泥中分离得到1株好氧反硝化细菌C3，并对其反硝化能力进行了研究．结果表明，c3菌株在好氧条件下能有效去除培养液中的硝酸盐氮，其脱氮率可达90％以上．通过对该菌株的形态观察，生理生化实验以及16SrDNA序列分析，确定菌株c3为假单胞菌（Pseudomonas sp．），同时分析了其在系统发育中的分类地位．对菌株C3的生态影响因子研究表明，其反硝化最适宜的温度和pH值分别为30％和7．0．和其他已报道的好氧反硝化菌相比，C3菌株有着更高的氧耐受浓度．C／N对菌株C3的好氧反硝化能力有很大影响，其最适宜的碳氮比是在5．5～6．0，在此区间能进行完全的反硝化．

A bacterial strain C3 screened from the activated sludge was found capable of aerobic denitrification and the denitrifying capability of the strain was studied in batch culture under aerobic condition. The results showed that the nitrate in the culture could be efficiently removed by strain C3 and the nitrogen removal rate was up to above 90 %. According to the morphological observation, physiological biochemical test and sequence analysis of the 16S rDNA, strain C3 was identified as Pseudomonas sp.. And the phylogentic position of the strain was performed based on the phylogenetic tree. The factors affecting aerobic denitrificatrion by strain C3 were also discussed. The results indicated that the most suitable temperature and pH value for aerobic denitrification were 30℃ and 7.0, respectively. The denitrification performance of strain C3 was almost not affected by the presence of oxygen and the strain C3 had a higher tolerance of dissolved oxygen concentration than other aerobic denitrifiers reported previously. The optimal C/N ratio was 5.5 - 6.0 and nearly complete denitrification can be obtained at the range of C/N ratio.