【摘要】 【目的】通过在复合垂直潜流人工湿地系统中筛选高效的硝化细菌和反硝化细菌,以降低氮素污染对养殖水域生态系统的危害,为加强人工湿地氮素净化功能提供科技支撑。【方法】在复合垂直潜流人工湿地—池塘循环水养殖系统的不同运行阶段采集样品,利用选择性培养基定向筛选,选择一株高效硝化细菌和一株高效反硝化细菌,对其进行菌种鉴定,并分别研究对应菌株的硝化特性或反硝化特性。【结果】通过个体形态特征观察、生理生化鉴定及16S rDNA同源性比对分析,确定硝化菌株ZX2属于不动杆菌属(Acinetobacter),反硝化菌株ZF7属于假单胞菌属(Pseudomonas)。在pH为7.0,温度为30℃,亚硝酸钠浓度为0.8 g/L的条件下硝化菌株ZX2的硝化能力最强,OD600可达0.80以上,硝化速率达68.4 mg/(L·d)。在pH为7.0,温度为35℃,接种量为6%的条件下反硝化菌株ZF7的反硝化能力最强,OD600可达1.00以上,脱氮率达94.5%。【结论】筛选得到的硝化细菌和反硝化细菌具有很好的氮素净化效果,可为下一步强化人工湿地氮素净化功能提供备用菌株。更多还原

【Abstract】 【Objective】A high-efficiency nitrifying bacteria and denitrifying bacteria was screened in the integrated vertical subsurface flow constructed wetlands system to reduce the harm of nitrogen pollution to the aquaculture water ecosystem,and provided a theoretical basis for strengthening the nitrogen purification function of the constructed wetlands.【Method】Samples were collected at different operational stages of the integrated vertical subsurface flow constructed wetland-pond recirculating aquaculture system. A selective media was used for targeted screening,then a high-efficiency nitrifying bacteria and a highly efficient denitrifying bacteria were selected for strain identification and studying separately the nitrification or denitrification characteristics of the corresponding strain.【Result】The nitrifying strain ZX2 was initially identified as Acinetobacter and the denitrifying strain ZF7 was Pseudomonas based on its morphological observation,physiological and biochemical tests as well as 16 S r DNA phylogenetic analysis. The nitrification ability of nitrifying strain ZX2 was the highest under the conditions of p H 7.0,temperature 30 ℃,and sodium nitrite concentration 0.8 g/L. OD600 value could reach above 0.80,and the nitrification rate reached 68.4 mg/(L·d). Under the conditions of pH 7,temperature 35 ℃,the inoculum amount 6%,the denitrification capacity of denitrifying strain ZF7 was the highest. OD600 value could reach above 1.00,and the denitrification rate reached 94.5%.【Conclusion】The nitrifying bacteria and denitrifying bacteria screened in this study have good effect on nitrogen purification,and can provide a spare strain for further strengthening the nitrogen purification function of the constructed wetlands.更多还原