叶酸对厌氧氨氧化细菌脱氮性能的影响研究

Effects of folic acid on nitrogen removal by anammox

考察了叶酸对厌氧氨氧化细菌对污水脱氮性能的影响,并从胞外聚合物(EPS)、血红素及细胞合成等方面进行了机理分析.结果表明,在叶酸添加量分别为0.5、1.0和1.5mg·L^(-1)时,均可提高厌氧氨氧化细菌的污水脱氮性能,且当叶酸浓度为1.5mg·L^(-1)时,脱氮性能最好.与对照组相比,在1.5mg·L^(-1)的叶酸添加量时,总氮去除率(TNRR)提高到45.3mg·g^(-1)·d^(-1),增加了32.1%;总EPS提高到175.9mg·g^(-1),增加了66.6%;血红素含量提高到2.35mg·g^(-1),增加了26.4%;厌氧氨氧化细菌功能基因总拷贝数提高到(2.87×10^(8)±1.79×10^(7))copies·g^(-1),增加了11.1%.经叶酸刺激培养后,污泥系统中的浮霉菌门相对丰度增加了3.5%,系统中占主导地位的厌氧氨氧化细菌为Candidatus Brocadia.

The impact of folic acid on nitrogen removal by anammox bacteria was evaluated in shortterm batch experiments.Results show that total nitrogen removal rate(TNRR)could be improved when the additional amount of folic acid was 0.5 mg·L^(-1),1.0 mg·L^(-1),and 1.5 mg·L^(-1),and the highest TNRR was observed at a folic acid concentration of 1.5 mg·L^(-1).Compared with the control group,the NRR,total extracellular polymeric substance(EPS),heme production,and anammox bacterial gene copy number at the folic acid concentration of 1.5 mg·L^(-1) reached 45.32 mg·g^(-1)·d^(-1),175.9 mg·g^(-1),2.35 mg·g^(-1),and(2.87×10^(8)±1.79×10^(7))copies·g^(-1),with an increase of 32.1%,66.6%,26.4%,and 11.1%,respectively.Moreover,the relative abundance of Planctomycetes in the sludge system increased by 3.5%,and the prevalent anammox bacteria were identified as Candidatus Brocadia.