与传统脱氮菌相比,异养硝化-好氧反硝化菌在脱氮方面具有较大优势并受到广泛关注.以乙酰胺为唯一氮源从活性污泥中分离得到1株脱氮性能较高的异养硝化-好氧反硝化细菌,命名为Y1.经形态观察、生理生化特征和16S rRNA分析后鉴定为Acinetobater johnsonii(约氏不动杆菌),革兰氏染色结果为阴性.对Y1菌株进行生理生化鉴定试验,结果显示Y1对吲哚、柠檬酸盐、硫化氢和接触酶的反应呈阳性,表明该菌株能良好的利用以上物质;而甲基红、葡萄糖发酵、蔗糖发酵、明胶液化、淀粉水解、氧化酶、尿素酶试验结果呈阴性,表明该菌株不能很好的利用以上物质.为了检测Y1菌株的脱氮性能,将其分别置于异养硝化培养基和好氧反硝化培养基进行培养,在108 h内,接种Y1菌株的异养硝化培养基中的氨氮去除率约为66.9%,去除速率达0.53 mg·L-1·h-1,硝氮去除率约为100%,去除速率达0.10 mg·L-1·h-1;在84 h内,接种Y1菌株的好氧反硝化培养基中的硝氮去除率约为69.7%,去除速率达0.74 mg·L-1·h-1,上述结果表明Y1菌株的脱氮性能较高.为了进一步研究该菌株的生长需求,保持其它条件不变的情况下,将其分别置于不同碳源和氮源下进行培养,结果表明,菌株Y1在琥珀酸钠为唯一碳源时的生长速率、异养硝化和好氧反硝化性能最好,并且利用无机氮源的能力比有机氮源能力强.%Compared with traditional removal of nitrogen, nitrogen removal by heterotrophic nitrification-aerobic denitrification (HNAD) bacteria has several advantages, which has been widely concerned. In this study, Y1, one strain of HNAD bacteria with high nitrogen removal performance was isolated from activated sludge using acetamide as the sole carbon source. According to the results of morphological observation, physiological and biochemical characteristics test and 16S rRNA sequencing, the strain Y1 was identified as Acinetobater johnsonii. The results of physiological and biochemical characteristics test indicated that Y1 was capable of decomposing indole, citrate, hydrogen sulfide and hydrogen peroxide, but couldn't utilize methyl red, glucose, sucrose, gelatin, starch, four methyl para-phenylene diamine hydrochloride and urea. In order to verify the nitrogen removal performance, Y1 was cultivated in heterotrophic nitrification medium and aerobic denitrification medium to measure the concentrations of NH4+-N, NO3--N, NO2--N. During the first 108 hours, 66.9% of the NH4+-N and 100% of the NO3--N in the heterotrophic nitrification medium were removed at a rate of 0.53 and 0.10 mg·L-1·h-1, respectively. During the first 84 hours, 69.7% of the NO3--N in aerobic denitrification medium was removed with a rate of 0.74 mg·L-1·h-1. The results above indicated that Y1 had high nitrogen removal performance. For further study the growth requirements, Y1 was cultured with different carbon and nitrogen sources under the same conditions, the results showed that Y1 grew best and had best nitrogen removal performance in the medium with sodium succinate as the sole carbon source, and Y1 utilized inorganic nitrogen better than organic nitrogen.
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