Acta Scientiarum Naturalium Universitatis Pekinensis ›› 2018, Vol. 54 ›› Issue (6): 1276-1282.DOI: 10.13209/j.0479-8023.2018.071

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Identification of an Aerobic Denitrifier and Its Denitrification Characteristics

LI Xue1, LIU Sitong2, CHEN Qian2,†   

  1. 1. School of Chemistry and Environmental Engineering, Lanzhou City University, Lanzhou 730070
    2. Beijing Engineering Research Center of Advanced Wastewater Treatment, Department of Environmental Engineering, Peking University, Beijing 100871
  • Received:2017-11-20 Revised:2017-12-27 Online:2018-11-20 Published:2018-11-20
  • Contact: CHEN Qian, E-mail: qianchen(at)pku.edu.cn

一株好氧反硝化菌的鉴定及脱氮特性研究

李雪1, 刘思彤2, 陈倩2,†   

  1. 1. 兰州城市学院化学与环境工程学院, 兰州 730070
    2. 北京大学环境工程系, 北京市新型污水深度处理工程技术研究中心, 北京 100871
  • 通讯作者: 陈倩, E-mail: qianchen(at)pku.edu.cn
  • 基金资助:
    北京市科技专项(Z161100005016034)资助

Abstract:

Strain HG-7 was identified as Pseudomonas sp. through 16s rRNA gene sequence analysis. The aerobic denitrification ability of strain HG-7 was further proved by the existence of the napA and nirK genes. Further studies showed that the optimal carbon resources for strain HG-7 were sodium acetate and sodium succinate, the optimal C/N ratio was 6−10, and the suitable temperature was 26−30℃. At this condition, with an initial nitrate nitrogen of 100 mg/L, 98% of nitrate could be removed in 48 hours and the amount of nitrite accumulation was very small. Moreover, with nitrite as the sole nitrogen source, 100% of nitrite could be removed at lower nitrite concentration. But the nitrite nitrogen removal rate was about 40% when the nitrite concentration increased to 91.4 mg/L, indicating that high nitrite concentration was harmful for aerobic denitrification by strain HG-7. The strain HG-7 has great potential to be used for biological nitrogen removal, which was particularly significant for actual wastewater treatment processes.

Key words: aerobic denitrifier, identification, nitrogen characteristics

摘要:

以筛选分离得到的好氧反硝化菌HG-7为研究对象, 经过16S rRNA同源性分析, 初步鉴定该菌株为假单胞菌属(Pseudomonas sp.)。对菌株HG-7反硝化功能基因的扩增结果表明, 菌体HG-7内存在好氧反硝化功能基因napAnirK, 证实该细菌为好氧反硝化细菌。对菌株的脱氮特性和影响因素的研究表明, 以硝酸盐氮为氮源时, 菌株的最适碳源为乙酸钠和丁二酸钠, 最佳C/N比为6~10, 最适宜的温度范围为26~30℃。在上述条件下, 菌株HG-7的好氧反硝化活性较高, 48小时内对100 mg/L硝酸盐氮的去除率可达98%, 且在反应过程中亚硝酸盐氮积累量较低。以亚硝酸氮为唯一氮源时, 低浓度条件下可实现100%的氮素去除率; 高浓度条件下, 脱氮速率则受到明显的抑制, 对91.4 mg/L的亚硝酸盐氮氮去除率约为40%。因此, 将该菌株应用于废水的脱氮处理, 可实现氮素的有效去除, 具有潜在的应用价值。

关键词: 好氧反硝化菌, 鉴定, 脱氮特性

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