拉乌尔菌sari01的分离及其异养硝化好氧反硝化特性

Isolation of Raoultella sp. sari01 and Its Heterotrophic Nitrification-Aerobic Denitrification Characteristics

拉乌尔菌属是肠杆菌科中新分类的一个属,具有降解多种环境污染物的能力.本研究通过异养硝化培养基富集,从活性污泥中筛选出1株拉乌尔菌,命名为sari01.通过单因素和响应曲面实验研究,得出菌株sari01硝化作用的最适条件：碳源为柠檬酸钠、pH为7.0~7.5、温度为30℃、C/N为15、接种量为7.5%、溶氧以装液量计取50 mL,此时氨氮去除率可达99.9%,其中33.7%被转化成气体而去除,剩余部分转化为细胞生物量.菌株sari01能够利用亚硝酸盐和硝酸盐为唯一氮源进行生长,在优化培养条件下氮的去除率分别为98.4%和65.2%.说明菌株sari01具有很强的异养硝化和好氧反硝化特性,能够独立完成异养硝化和好氧反硝化脱氮过程,在污水处理中具有潜在的应用价值.

The genus of Raoultella belongs to the family of Enterobacteriaceae,and some strains of Raoultella sp. have the function of degrading chemical pollutants in the environment. A Raoultella sp. strain was isolated from activated sludge through enrichment cultured with heterotrophic nitrification medium. This strain was named Raoultella sp. sari01. Single-factor and response surface methodology experiments results showed that efficient heterotrophic nitrification of strain sari01 occurred with sodium citrate as the carbon source,at pH of 7. 0-7. 5,temperature of 30℃,C / N ratio of 15,inoculation volume of 7. 5% and loading volume of 50 m L,while the removal rate of nitrogen was 99. 9%,of which 33. 7% was converted to gaseous product and escaped to air,and the residual nitrogen was fixed in cell biomass. Using nitrite and nitrate as the sole nitrogen source,the nitrogen degradation ratios were 98. 4% and65. 2%,respectively. Hence,strain sari01 could remove nitrogen by heterotrophic nitrification-aerobic denitrification independently,quickly and effectively,which demonstrated that strain sari01 has the potential to be used in wastewater treatment.