3株贫营养好氧反硝化细菌的分离鉴定及反硝化特性

贫营养好氧反硝化细菌在水环境能量流动和物质循环过程中扮演着重要的角色。从山东某水源水库沉积物中共驯化分离出216株好氧反硝化细菌,复筛得到3株高效菌株ZN1、ZN2和ZN3。经形态学指标和16S rRNA序列分析,ZN1和ZN3属于铁还原细菌(iron-reducing bacterium),ZN2属于粘液菌属(Zoogloea sp.)。关键酶基因检测表明3株菌均含有周质硝酸盐还原酶基因(napA)。在30℃、120 r/min条件下,培养47 h后3株菌对培养液中NO3-N的去除率均在80%以上,TN去除率均在40%以上,且无明显的亚硝氮积累。对3株菌分别进行原水适应,以20%的梯度增加原水的比例直至100%原水。原水培养72 h后,3株菌NO3-N去除率为30%~40%,TN去除率为20%~25%。

Isolation and identification of three oligotrophic aerobic denitrifying bacteria and denitrification characteristics

Oligotrophic aerobic denitrifying bacteria plays a vital role in the process of energy flow and material cycling of aquatic environmental conditions. In this study, 216 aerobic denitrifying bacteria strains were isolated from the sediment of a drinking water reservoir in Shandong Province, and three highly efficient strains named ZN1, ZN2 and ZN3 were obtained. According to morphological characteristics and 16S rRNA sequence, ZN1 and ZN3 were affiliated to iron-reducing bacterium, whilst ZN2 was affiliated to Zoogloea sp. Meanwhile, periplasm nitrate reductase gene(napA) was detected. At 30℃ and 120 r/min, the nitrate and total nitrogen removal rates of three strains reached to 80% and 40%, respectively, and without obvious accumulation of nitrite. The strains were adapted to raw water with the 20% gradient program from nutrient medium to raw water. After 72 h cultivation in raw water, the nitrate and total nitrogen removal rates of the strains reached to 30%~40% and 20%~25%, respectively.