好氧反硝化菌的筛选鉴定及其脱氮特性研究

SCREENING, IDENTIFICATION AND DENITRIFICATION CHARACTERISTICS OF AEROBIC DENITRIFIERS

通过分离筛选获得3株好氧反硝化菌S1、S2和S3,初步鉴定S1为土生拉乌尔菌属(Raoultella terrigena),S2和S3均为解鸟氨酸拉乌尔菌属(Raoultella ornithinolytica)。这3株菌为好氧反硝化菌属首次报道,对其好氧反硝化脱氮特性的研究结果表明,培养液中氮含量的大幅变化均发生于菌株的对数生长期;在以硝酸盐或亚硝酸盐为唯一氮源的研究中,NO3--N和NO2--N的24h去除率分别约为26%和67%,说明这3株菌更容易利用亚硝酸盐进行好氧反硝化;而且研究结果还表明,S3为脱氮效率最优的菌株,对低氮浓度的富营养化水质有较好的反硝化效果,4 h时S3的反硝化速率最大,达0.62mg·L-1·h-1,对TN的反硝化脱氮贡献率可达52.5%。

Three aerobic denitrifiers （S 1, S2 and S3 ） were abtained by isolating and screening. Strain S1 was identified as Raoultella terrigena, while strains S2 and S3 were identified as Raoultella ornithinolytica. It is first reported that the three bacteria are aerobic denitrifiers. Studies on their aerobic denitrification characteristics showed that significant changes of nitrogen level in culture media occurred in the logarithmic growth phase of strains; in the studies on using nitrate or nitrite as sole nitrogen source, respectively, the removal rates of NO3--N and NO2-N were 26% and 67% at 24 h, respectively, which proved that nitrite was used more easily for aerobic denitrification of three strains;Results also showed that $3 was optimal strain with the highest removal efficiency of nitrogen, which had better denitrification effects on eutrophic water with low concentration nitrogen, and S3 had the highest denitrification rate of 0.62 mg.Ll.h＂1 and denitrification contribution rate of TN up to 52.5% at 4 h.