贫营养好氧反硝化菌的分离鉴定及其脱氮特性

为了分离贫营养好氧反硝化菌,研究其系统发育地位和脱氮特性,以期为微污染水库水体生物修复提供依据.从水库底层沉积物中,采用改良的富集驯化方法分离好氧反硝化菌,通过N-J法进行系统发育分析以及选择培养基研究其脱氮特性.初筛分离出196株好氧反硝化菌,其中14株为高效菌株(ZHF2、ZHF3、ZHF5、ZHF6、ZHF8、ZMF2、ZMF5、ZMF6、N299、G107、81Y、SF9、SF18和SXF14).经形态学,生理生化,和16S rRNA基因序列分析,ZHF3、ZHF5、ZHF6、ZMF2、G107、81Y、SF18和SXF14为不动杆菌(Acinetobacter sp.),ZHF2和ZHF8为新鞘脂菌属(Novosphingobium sp.),ZMF5为水杆菌属(Aquabacterium sp.),ZMF6为鞘脂单胞菌属(Sphingomonas sp.),N299为动胶杆菌属(Zoogloea sp.),SF9为代尔夫特菌属(Delftia sp.).其中菌株G107和81Y的反硝化效果最好,72h的硝氮去除率达到98.88% 和99.44%.并以G107和81Y为代表进行一系列的脱氮实验,结果显示出良好的短程反硝化、硝化和源水脱氮能力.贫营养好氧反硝化菌的分离,补充和丰富了好氧反硝化菌的种类,其高效的脱氮特性为低氮微污染水体的生物修复提供了技术支撑.

Isolation,Identification, and nitrogen removal characteristics of oligotrophic aerobic denitrifiers

In order to isolate the aerobic denitrifiers from oligotrophic reservoir system, and study the taxonomic status and nitrogen removal characteristics for providing evidence to remediate the micro-polluted source water. The oligotrophic aerobic denitrifiers were obtained, through enrichment, domestication, and screening processes, and taxonomic statuses were determined by 16S rRNA, and the nitrogen removal characteristics was detected in the pure culture and source water experiment. As a result, 196 strains were isolated, and 14 strains (ZHF2, ZHF3, ZHF5, ZHF6, ZHF8, ZMF2, ZMF5, ZMF6, N299, G107, 81Y, SF9, SF18, and SXF14) demonstrated the perfect nitrogen removal performances. Based on morphological, physiological, and phylogenetic analysis, ZHF3, ZHF5, ZHF6, ZMF2, G107, 81Y, SF18, and SXF14 were identified as Acinetobacter sp.; ZHF2, and ZHF8 were identified as Novosphingobium sp.; ZMF5 was identified as Aquabacterium sp.; ZMF6 was identified as Sphingomonas sp.; N299 was identified as Zoogloea sp.; SF9 was identified as Delftia sp.. The nitrate removal rates of G107 and 81Y reached 98.88% and 99.44%, in 72h. Meanwhile, the oligotrophic aerobic denitrification bacteria G107 and 81Y demonstrated the obvious nitrogen removal performances in nitrite medium, ammonia medium and source water medium. From all the results, the isolations of oligotrophic aerobic denitrifiers enriched the species of aerobic denitrification bacteria, and the perfect nitrogen removal performances provided a significant parameter to remediate the micro-polluted reservoir water system.