一株异养脱硫反硝化菌株的筛选及其生物脱硫脱氮特性研究

Isolation and characterization of a functional strain with the highly efficient of biological desulfurization and denitrification

摘要:

【目的】从生物脱硫脱氮EGSB-DSR反应器的污泥中分离筛选出具有生物脱硫脱氮特性的细菌，并对其生物脱硫脱氮的性能进行研究。【方法】采用Hungate厌氧滚管技术筛选功能微生物，从稳定运行的生物脱硫脱氮EGSB-DSR反应器的污泥中分离筛选出一株高效的生物脱硫脱氮细菌A2。【结果】经过16S rRNA基因序列鉴定，菌株A2为固氮弧菌属(Azoarcus sp.)。其典型特征为能够以有机碳作为电子供体，将亚硝酸盐或者硝酸盐转化为氮气的同时还能将硫化物氧化为硫单质。因此具备了高效同步代谢有机碳、NO3–和S2–的特征。这是首次关于固氮弧菌属能够进行反硝化脱硫的相关报道。对菌株A2的生物脱硫脱氮能力的分析表明，在硫化物S2–浓度200 mg/L，NO3?浓度87.5 mg/L，乙酸根离子浓度200 mg/L的条件下，菌株A2在20 h内完成对碳、氮、硫的脱除。菌株对于碳、氮去除率均达到99%，对于硫的去除率达到95%。【结论】结果表明固氮弧菌属A2具有高效的生物脱硫脱氮功能，将有望成为强化生物脱硫脱氮工艺的潜在微生物资源。

Abstract:

[Objective] To isolate a functional strain with the highly efficient of biological desulfurization and denitrification from EGSB-DSR reactor, and study the characterization of the strain. [Methods] In this study, using the Hungate anaerobic roll tube technique a strain with the function of desulfurization and denitrification, A2, was isolated from EGSB-DSR reactor. [Results] Identification based on 16S rRNA sequence indicates that the isolate has a homologous similarity of 99% with Azoarcus sp.. In metabolic of A2, sulfide was adopted for its electron donor and nitrate for electron acceptor. This is the first report about the function of Azoarcus sp. in the desulfurization and denitrification process. The desulfurization and denitrification characterization of the strain shows that strain A2 degraded acetate, nitrate and sulfate in 20 hours completely, with the S2– concentration of 200 mg/L, NO3– concentration of 87.5 mg/L and the Ac– concentration of 200 mg/L. The removal rate of sulfate, nitrate and acetate is 95%, 99% and 99%, respectively. [Conclusion] This result indicates that newly isolated strain A2 with a high capability of desulfurization and denitrification. Strain A2 is a potential microbiology resource for the efficiency improvement of simultaneous desulfurization and denitrification process.