氨氧化菌的分离鉴定及其在罗氏沼虾育苗废水中的应用

Isolation,identification of an ammonia-oxidizing bacteria and its application in treatment of wastewater from breeding of Macrobrachium rosenbergii

氨氮转化细菌在养殖水生态系统的物质循环和水体净化的过程中起着重要作用。该研究从养殖池塘底泥中筛选具有氨氮去除能力的细菌,通过生化和分子生物学技术进行细菌鉴定,并用于罗氏沼虾育苗用水的氨氮净化。结果表明:分离获得的氨氮去除菌YX0703能在无机氮培养基和有机氮培养基中生长,既具有氨氮氧化活性,也能将NO_3^-转化为NO_2^-,再将NO_2^-转化为N_2,经鉴定,该菌为人苍白杆菌(Ochrobactrum anthropi);该菌株携带亚硝酸还原酶基因(Nitrite reductase K gene,nirK),药物最低抑菌浓度检测发现,其对头孢类抗菌素耐药,对喹诺酮类、美罗培南和四环素等抗菌药物敏感;摇床转速150 r·min^(-1)时,在25、30℃条件下,菌株YX0703对罗氏沼虾育苗废水的氨氮去除率分别为96.98%和97.44%。综上,分离获得的氨氮去除菌YX0703是人苍白杆菌,其既能利用无机氮又能利用有机氮,既具有氨氧化活性又有反硝化活性,可用于罗氏沼虾育苗废水的氨氮净化。

Ammonia-oxidizing bacteria play an important role in material cycles and water purifying processes in aquaculture ecosystems. In the present study,the screening of bacteria with capability to remove ammonia nitrogen from sludge on the bottom of an aquaculture pond was carried out,and the bacteria isolated were identified by biochemical tests and molecular methods,then,which were used for treatment of ammonia nitrogen in wastewater from breeding of Macrobrachium rosenbergii. The results showed that the isolated strain YX0703 with capability to remove ammonia nitrogen was Ochrobactrum anthropi,which was able to grow on both inorganic and organic nitrogen medium; Strain YX0703 not only had ammonia oxidation activity,but also had the ability to convert NO3- into NO2-,then convert NO2- into N2. Moreover,strain YX0703 carried nitrite reductase K gene（ nir K）. The determination of minimal inhibitory concentration（ MIC） indicated that strain YX0703 was resistant to cephalosporins,but sensitive to some antibiotics,such as quinolones,meropenem and tetracycline; the removal rate of ammonia nitrogen in wastewater frombreeding of Macrobrachium rosenbergii were 96. 98% and 97. 44%,respectively,when shaker speed was 150 r·min-1,at 25 and 30 ℃. These results suggested that the isolated strain YX0703 was capable of using inorganic or organic nitrogen,which also had activity of ammonia-oxidizing and denitrification,and was useful for removal of ammonia nitrogen in wastewater from breeding of Macrobrachium rosenbergii.