好氧反硝化细菌Burkholderia sp.ZH8的脱氮特性与生物强化作用

Nitrogen removal characteristics and bioenhancement effects of aerobic denitrifying bacteria Burkholderia sp.ZH8

针对传统生物脱氮处理含氮废水工艺流程复杂、脱氮效率低的问题,从实验室运行稳定的生物滤池筛选得到一株好氧反硝化菌株ZH8,该菌株具有较强的异养硝化和好氧反硝化能力.通过形态学、生理生化特征及16S rDNA序列分析,鉴定菌株ZH8为伯克氏菌(Burkholderia sp.).单因素试验表明,好氧反硝化菌株ZH8的最佳培养条件为:碳源为丁二酸钠,C/N为15,温度为30℃,转速为160r/min和pH值为7~8.此外,菌株ZH8不仅能以NH_(4)^(+)-N、NO_(3)^(-)-N或NO_(2)^(-)-N分别为单一氮源进行生长,而且在混合氮源条件下也可实现同步硝化反硝化作用.通过全基因组分析,菌株ZH8的异养硝化脱氮为谷氨酸脱氢酶途径的铵同化过程,好氧反硝化途径为:NO_(3)^(-)-N→NO_(2)^(-)-N→NO→N_(2)O→N_(2),碳代谢途径包括三羧酸循环、乙醛酸循环、糖酵解和戊糖磷酸.在采用纯菌ZH8为菌种培养的生物膜反应器中,反应运行至8~15d即可完成挂膜,系统可维持高效稳定的脱氮性能,NH_(4)^(+)-N、NO_(3)^(-)-N及TN的去除率均可达到90%以上.该菌株为生物处理领域提供了新型菌种资源,能够有效处理含氮废水,具有实际应用价值.

Aiming at the problems of complicated process and low denitrification efficiency of traditional biological denitrification treatment of nitrogen-containing wastewater,an aerobic denitrification strain ZH8 was screened from a stable biological filter in the laboratory,and this strain had strong heterotrophic nitrification and aerobic denitrification ability.Strain ZH8was identified as Burkholderia sp.by morphological,physiological and biochemical characteristics and 16S rDNA sequence analysis.The single factor experiments showed that the optimal culture conditions of aerobic denitrification strain ZH8were as follows:carbon source was sodium succinate,C/N was 15,temperature was 30,rotational℃speed was 160r/min and pH was 7~8.In addition,strain ZH8 could not only grow with NH_(4)^(+)-N,NO_(3)^(-)-N or NO_(2)^(-)-N as a single nitrogen source,but also achieve simultaneous nitrification and denitrification under mixed nitrogen source conditions.According to the whole genome analysis,heterotrophic nitrification of strain ZH8 was ammonium assimilation through glutamate dehydrogenase pathway,and aerobic denitrification pathway was NO_(3)^(-)-N→NO_(2)^(-)-N→NO→N_(2)O→N_(2).Carbon metabolism pathway included tricarboxylic acid cycle,glyoxylic acid cycle,glycolysis and pentose phosphate.In the biofilm reactor cultured with pure bacterium ZH8,the reaction could be completed after 8 to 15 days,and the system could maintain efficient and stable nitrogen removal performance,and the removal rates of NH_(4)^(+)-N,NO_(3)^(-)-N and TN reached more than 90%.The strain provides a new strain resource for wastewater bio-treatment,which can effectively treat nitrogen-containing wastewater and has practical application value.