2株好氧反硝化菌还原能力测定及菌种鉴定

目的研究好氧反硝化菌株WXZ-15、WXZ-19的还原能力和菌种鉴定。方法采用四因素三水平正交实验确定可能最优还原条件[如碳源与总氮源的浓度比值(COD/N)、初始NO2-(以氮计)浓度、摇床转速、初始pH值]。分别以NO3-、NO2-为底物,对好氧反硝化菌株WXZ-15、WXZ-19进行还原能力测定。并采用部分长度16SrDNA序列分析对实验菌株进行鉴定。结果极差分析显示,WXZ-15可能最优还原条件:COD/N为10,转速为160r/min,初始NO2-浓度为200mg/L,初始pH值为7.5,WXZ-19可能最优还原条件:COD/N为10,转速为160r/min,初始NO2-浓度为50mg/L,初始pH为7.5。不同氮源的还原能力实验发现,WXZ-15、WXZ-19两株菌以NO3-(以氮计)为底物时的总氮(TN)去除率分别为85.65%,45.23%,以NO2-(以氮计)为底物时的TN去除率分别为52.32%,35.40%。结论好氧反硝化菌株WXZ-15、WXZ-19具有较强的还原能力,均可直接还原NO2-(以氮计)。WXZ-15菌株为Delftiatsuruhatensi,WXZ-19菌株为Pseudomonas putida。

Study on Reducing Capacity and Identification of Aerobic Denitrifiers

Objective To research reducing capacity and identification of aerobic denitrifiers WXZ-15 and WXZ-19. Methods Four factors three levels [L9(34)] orthogonal experiment was adopted to determine the best experimental condition for reducing capacity of aerobic denitrifiers WXZ-15 and WXZ-19.The tests were conducted to study the reducing capacity to reduce nitrate in the presence of NO2-and NO3-. Partial 16S-rRNA analysis was used to identify aerobic denitrifiers WXZ-15 and WXZ-19. Results The result of range analysis showed the best experiment condition of WXZ-15 aerobic denitrifier,in which COD/N was 10,rotating speed was 160 r/min,the inital NO2-concentration was 200 mg/L,initial pH was 7.5,and that of aerobic denitrifier WXZ-19,in which COD/N was 10,rotating speed was 160 r/min,inital NO2-concentration was 50 mg/L,initial pH was 7.5. Comparing experiment showed that the TN removing rates of aerobic denitrifiers WXZ-15 and WXZ-19 were 85.65% and 45.23% respectively,using NO3-as nitrogen source. While the TN removing rates of aerobic denitrifiers WXZ-15 and WXZ-19 were 52.32% and 35.40% respectively,using NO2-as nitrogen source. Conclusion Aerobic denitrifiers WXZ-15 and WXZ-19 are Delftia tsuruhatensi and Pseudomonas putida respectively.The reducing capacity of aerobic denitrifiers WXZ-15 and WXZ-19 is strong.