高温好氧反硝化菌的分离鉴定及其反硝化性能研究

Identification and Denitrification Characteristics of a Thermophilic Aerobic Denitrifier

通过高温筛选,从燃煤电厂生物滴滤系统填料的生物膜上分离出1株高效好氧反硝化细菌TAD1.该菌株革兰氏染色呈阴性,短杆状,大小为(0.67～0.89)μm×(1.03～1.41)μm;经生理生化特性和基于16S rDNA序列分析,初步鉴定该菌为螯台球菌属(Chelatococcus sp.).对菌株TAD1的反硝化性能进行研究,结果表明,50℃高温、好氧培养条件下,该菌株24 h内将培养液中的硝酸盐氮由63.79 mg/L降至0.46 mg/L,脱氮率高达99.12%,反应过程中没有检测到亚硝酸盐氮的积累,氮气是反硝化过程的最终产物.在反硝化过程中,pH值呈逐渐上升趋势,而氧化还原电位(ORP)呈逐渐降低趋势.对菌株TAD1的生态影响因子研究表明,其反硝化最适宜的pH值为7.0～9.0,溶解氧浓度为2.1～7.2 mg/L.

A bacterial strain TAD1 with high nitrogen removal efficiency was isolated from biofilm of the biotrickling filter of a coal-fired power plant by thermophilic domestication. This bacterium was Gram negative, short rod, with the size of （0. 67-0. 89） μm× （ 1.03- 1.41） μm. It was identified as Chelatococcus sp. according to its physiological properties and the analysis of its 16S rDNA gene. Studied on its function of aerobic denitrification at the temperature of 50℃ , the results showed that nitrate in the culture media was efficiently removed from 63.79 mg/L to 0.46 mg/L, and the nitrogen removal efficiency was up to 99.12% in 24 hours, and no nitrite was observed during the incubation, the major end product of the denitrification was nitrogen. During the denitrification of TAD1, the pH in the culture medium gradually increases, while the oxidation-reduction potential gradually decreases. The factors affecting aerobic denitrification by strain TAD1 were also discussed, indicating that the most suitable pH value for aerobic denitrification was 7.0-9.0, and the DO was 2. 1-7. 2 mg/L