土壤中好氧反硝化菌的分离及脱氮特性研究

Screening aerobic denitrifiers from soil and study on characteristics of denitrification

采用极限稀释、滴加格里斯试剂和二苯胺试剂鉴别、平板划线相结合的方法,从土壤中分离到1株能以硝酸钾为氮源进行好氧反硝化作用的细菌,命名为LD3,菌株革兰氏染色为阳性,形状为杆状和球状,菌落光滑湿润,呈白色,菌株LD3鉴定为脂肪杆菌属。对菌株LD3反硝化能力进行了研究,结果表明,LD3菌株在好氧条件下能有效去除培养液中的硝酸盐氮,其去除率高达97.67%。菌株LD3反硝化影响因子研究表明,除过高浓度的亚硝酸盐对菌株生长有一定的抑制作用外,菌株具有较广的碳源和氮源谱,反硝化最佳的C/N为8,最优的pH为7.5左右,最适宜的温度范围为30～35℃。

An aerobic denitrifying bacterial strain name as LD3 was isolated from soil by using a new screening method.Samples were enriched by limiting diluted firstly,secondly screened with Griess and Diphenylamine reagent,then streak plate.The gram stain of the strain was positive,the cells growth cycle was rod or spherical,the clones of the strain were smooth,wet and white,the strain LD3 was identified as genus pimelobacter.Strain LD3 could denitrify nitrate companying with the formation of potassium nitrate in aerobic environment.The denitrifying capability of the strain was studied in batch culture under aerobic condition.The results showed that the nitrate in the culture could be efficiently removed by strain LD3 and the nitrogen removal rate was up to above 97.67%.The factors affecting aerobic denitrificatrion by strain LD3 were also discussed.The results indicated that strain LD3 had a wider spectrum of carbon and nitrogen source except for high concentrations of nitrite inhibiting the growth of the strains,the optimal C/N ratio and pH value for aerobic denitrification were 8 and about 7.5,the most suitable temperatures for aerobic denitrification were 30~35 ℃.