博斯腾湖沉积物氨氧化细菌的筛选与鉴定

为了解干旱区淡水湖泊沉积物微生物在氨氧化中的功能,利用铵盐培养基对博斯腾湖不同深度沉积物进行驯化培养,结合水环境因子分析混合菌株产亚硝酸盐能力,从中分离纯化氨氧化细菌并对其氨转化能力进行试验。结果表明,6个采样位点12个样品中,11号位点深层沉积物(20～40 cm)混合菌株能有效利用铵盐产生亚硝酸盐,且连续6 d稳定维持其质量浓度高达20 mg/L以上。进而,从该混合菌液中分离得到30株单菌,其中有2株呈现出明显的氨氧化细菌特性。通过16S rRNA基因序列比对及形态学分析分别鉴定其为弯曲芽孢杆菌(Bacillus flexus)和赤红球菌(Rhodococcus ruber)。

Isolation and Identification of Ammonia-oxidizing Bacteria from Sediment of Bosten Lake

The purpose of this study is to understand the ammonia oxidation of sediment microorganisms in water of fresh lakes in arid areas,the nitrite production ability of the mixed cultures of the sediment at different depths from Bosten Lake was analyzed by using the ammonium salt medium.And the ammonia-oxidizing bacteria were isolated,identified and its ability on ammonia translation was estimated.The results indicated that in 12 samples from 6 sampling sites,the deeper sediments of mixed culture from depth of 20-40 cm of site No.11 could effectively use aminium salt to produce nitrite,and its concentration could be kept as high as 20 mg/L for 6 days Then,thirty strains were isolated from the mixed cultures,two of which showed obvious ammonia-oxidizing activities.Based on the morphological and 16S rRNA sequence,the two strains were identified as Bacillus flexus and and Rhodococcus ruber.