一株异养硝化细菌的分离鉴定和脱氮特性研究

筛选对高浓度NH3-N养殖废水具有高效硝化能力的菌株，研究其硝化性能。通过比较几种已报道的筛选方法和不同生境中异养硝化细菌筛选效果，确定了以乙酰胺为唯一碳源和氮源，从高氨氮生境中可以筛选到高效的异养硝化细菌；进一步通过富集培养分离，从沼气池出水口水中分离到一株异养硝化细菌，并根据部分长度的16S rDNA序列进行了系统发育分析。该菌株具有高效异养硝化功能，在初始氨氮浓度为104 mg·L-1的异养氨化培养基中培养12 h后，氨氮和总氮去除率分别达81.7%和53.7%，最终氨氮和总氮去除率可达90.1%和61.3%，且培养液中无明显的硝酸盐氮和亚硝酸盐氮累积。16S rDNA的序列分析鉴定，该菌株与Paracoccus denitrificans具有99%相似性，结合生理生化分析认定该菌株是一株脱氮副球菌，命名为Paracoccus denitrificans FJAT-14899。筛选出的菌株Paracoccus denitrificans FJAT-14899对氨氮具有高效的去除率，显示了良好的应用前景。

Isolation and Denitrification Characteristics of a Heterotrophic Nitrification Bacterium

The present paper dealt with isolation and denitrification characteristics of a heterotrophic nitrification bacterium, which isolated from the high NH3-N swine wastewater. Based on the screening methods published by some scientists, a isolating method in the study was put forward to used an acetamide as a sole carbon and nitrogen source to screen a heterotrophic nitrifying bacterium from the swine wastewater. An efficient heterotrophic nitrification bacterium was isolated and identified with 16S rDNA sequence. The phylogenetic analysis of the strain was performed based on the 16S rDNA sequence. The efficiency of heterotrophic nitrification was detected for the strain. The strain FJAT-14899 was identified to be Paracoccus denitrificans with the aid of 16S rDNA sequencing. The removal rates for the total concentrations of nitrogen and NH4-N were 81.7% and 53.7% in 12 h cultural time. The final removal rates of the total nitrogen and NH+4-N were 90.1% and 61.3% after 24 h culturing without accumulations of nitrite nitrogen and nitrate nitrogen. Paracoccus denitrificans FJAT-14899 had a higher removal rate of NH+4-N with promissing application in water treatment.