自养混合菌群氨氧化特征及结构分析

Ammoxidation characteristics and composition analysis of autotrophic mixed bacteria

从某污水厂活性污泥中分离、筛选获得了一组高效的自养氨氧化混合茵群.通过批式培养,结果表明,其最适温度和 pH 分别为30℃和7.0～7.5;溶解氧浓度对氨氧化影响较小;0～1.0%的盐度对氨氧化速率无影响,盐度超过1.0%时,氨氧化速率迅速下降;磷含量在20～900mg/L 时对氨氧化无影响;氨氮浓度在0～1000mg/L 时茵群生长正常,氨氧化速率最高可达150mg·L^(-1)·d,氧化终产物主要为亚硝酸盐,残留氨浓度低至0～3mg/L.通过PCR-DGGE 检出5株氨氧化菌,初步确定均为亚硝化单胞茵属(Nitrosomonas sp.),并发现茵群中还存在其它与氮转化有关的菌种.

A set of autotrophic mixed ammoxidation bacteria with high efficient was screened from active sludge of a sewage purification-factory. Batch tests were performed. The results showed that the optimum temperature and pH were 30 ℃ and 7.0-7.5, respectively. DO had little effect on ammoxidation. Ammonia oxidation rate （AOR） has no apparent change under 0- 1.0 % salinity stress but decreased rapidly when the salinity was over 1.0%. AOR changed little on PC of 20-900 mg/L. These bacteria grew well on ANC （0-1000 mg/L）. The maximum AOR could reach 150 mg · L^-1· d. The end products of oxidation mainly were nitrite and the residual ANC was below 3 mg/L. Five strains of ammoniaoxidizing bacteria were identified and primarily classified as Nitrosomonas sp. by using PCR-DGGE and sequencing. In addition, some other bacteria related to nitrogen transformation were found by PCR with specific primers.