含水层介质中1株异养硝化-好氧反硝化菌的分离鉴定与脱氮性能

从受氮污染浅层含水层介质中分离纯化得到1株高效异养硝化-好氧反硝化细菌XK51,经过菌落形态、生理生化特性及16S rDNA基因序列分析,鉴定该菌株为假单胞菌属恶臭假单胞菌(Pseudomonas Putida)。脱氮性能结果表明:XK51为兼性反硝化细菌,能在好氧或缺厌氧条件下高效反硝化脱氮,最大和平均反硝化速率分别为27.3,4.4 mg/(L·h),硝酸盐脱除率为95.3%;该菌株同时具有较高异养硝化能力,最大和平均硝化速率分别为4.2,1.4 mg/(L·h),氨氮脱除率为98.5%。XK51最佳碳源为柠檬酸三钠,适宜生长温度为28~35 ℃,最适温度为30 ℃;适宜生长pH为6.5~8.0,最适pH为7.0。XK51可同时进行异养硝化及同步硝化-反硝化,培养期间未出现明显亚硝酸盐和硝酸盐累积,在含氮污废水处理和地下水氮污染修复方面具有潜在工程应用价值。

IDENTIFICATION AND NITROGEN REMOVAL CHARACTERISTICS OF A HETEROTROPHIC NITRIFICATION-AEROBIC DENITRIFYING STRAIN ISOLATED FROM UNCONFINED AQUIFER POROUS MEDIA

A heterotrophic nitrification and aerobic denitrification bacterium strain named XK51 was isolated and purified from nitrogen-contaminated shallow aquifer porous media. The strain was identified as Pseudomonas Putida by morphological observation, physiological and biochemical characteristics and 16S rDNA gene sequence analysis. The results showed that strain XK51 was a facultative denitrifying bacteria, which could achieve high denitrification efficiencies under aerobic or anaerobic conditions. The maximum and average denitrification rate were 27.3 mg/(L·h) and 4.4 mg/(L·h), the nitrate removal efficiency was 95.3%. XK51 also had high heterotrophic nitrification capacity, and its maximum and average nitrification rate were 4.2 mg/(L·h) and 1.4 mg/(L·h), then the ammonia removal efficiency was 98.5%. The optimum carbon source was trisodium citrate, and the optimum growth temperature ranged from 28 to 35 ℃, with a preferred value of 30 ℃. The optimum cultivating pH value ranged from 6.5 to 8.0, with a preferred value of 7.0. Strain XK51 could simultaneously carry out heterotrophic nitrification and simultaneous nitrification-denitrification with no obvious nitrite and nitrate accumulation during cultivation. It has potential engineering application value in nitrogen-containing wastewater treatment and nitrogen pollution remediation of groundwater.