一株产生氨氮和亚硝酸盐氮菌的筛选鉴定及特性研究

从4个草鱼池塘中分离和定性筛选获得29株能够产生氨氮和亚硝酸盐氮的菌株。通过对编号为C95的菌株进行菌落形态学观察和16S rDNA序列分析,表明该菌株为革兰氏阴性杆状菌,与寡养单胞菌属（Stenotrophomonas sp.）的同源性达98%。采用单因素多水平试验对菌株的产氨氮和产亚硝酸盐氮特性进行研究发现：（1）氮源、碳源、温度和摇床转速都能显著影响菌株的生长及产生氨氮和亚硝酸盐氮的含量,但pH（5～9）对其无显著影响（P〉0.05）;（2）该菌株生长及产生氨氮和亚硝酸盐氮最适宜的培养基以及培养条件为：LB、pH 5～9、25℃、150 r.min-1。由C95作为指示菌株筛选得到SC01、SC07两株（2/33）去除氨氮和亚硝酸盐氮效果较好的菌株。因此,C95可作为筛选具有降氨氮和亚硝酸盐氮功能的有益菌的指示菌株。

Isolation, Identification and the Characteristics of a Strain with Ability of Producing Ammonia and Nitrite

Twenty nine strains with ability of producing ammonia and nitrite were isolated from culture water of 4 grass carp ponds through qualitative filtration. One of them, named C95, was identified as a Gram negative, rod-shaped strain exhibiting the highest sequence homolo- gy to Stenotrophomonas sp. （98%） according to its colony morphological properties and the 16S rRNA sequence analysis. Characterization of growth and ammonia nitrogen and nitrite nitrogen production revealed that： （1）nitrogen resource, carbon resource, temperature and rotation speed could significantly affect the strain properties; （2）the optimal substrate, pH, temperature and rotation speed were LB, pH5 -9, 25 ℃, 150 r· min-1, respectively. Two strains（ 2/33 ） named SC01 and SC07 that can degrade ammonia and nitrite better were isolated by the strain C95 as an indicator strain for the beneficial bacteria with ammonia and nitrite nitrogen removal function, which has potential application val- ue to improve the quality of culture water.