一株高效转化硝态氮细菌的分离鉴定和特性研究

为寻找可有效改良土壤次生盐渍化的微生物材料,从次生盐渍化严重的设施栽培土壤中分离出一株可高效转化硝态氮的细菌,命名为NCT-2。菌株经革兰氏染色为阳性,无荚膜、有芽孢、长杆状。根据形态、生理特征和分子生物学特性将该菌株鉴定为巨大芽孢杆菌（Bacillus megaterum）。在马铃薯培养基中的最佳培养条件为：pH7.0、温度35℃,培养4 h后进入对数生长期,18 h后达到稳定生长期。经研究表明,当培养基中硝态氮含量为500 mg/L时,该菌株3 d后能使硝态氮含量降低83.25%。

Isolation,Identification and Characterization of One Nitrate Nitrogen Transforming Bacteria

In order to obtain a micrological material for effectively improving the quality of the soils with nitrogen salinization,a bacterial strain,named NCT-2,which could transform nitrate nitrogen,was isolated from the soils with over salinization.It was a gram positive and long-rod shaped bacterium with spore but without capsule,belonging to Bacillus sp..The phylogenetic analysis based on the partial 16s rDNA suggested that the strain NCT-2 was mostly relative to Bacillus megaterum.The best cultural conditions for the strain NCT-2 was pH 7.0,35 ℃ in potato medium.In addition,the growth of the strain was at the exponential growth phase after 4 hours,and at the stationary phases after 18 hours.When the concentration of nitrate nitrogen was 500 mg/L,83.25% of nitrate nitrogen was decreased by the strain NCT-2 after 3 days.