一株丛毛单胞菌对2-吡啶甲酸的好氧生物降解
Aerobic Biodegradation of 2？？Picolinic Acid by a Comamonas sp.

在好氧条件下分离筛选到一株以2？策拎ぜ姿嵛？唯一碳、氮、能源的菌株,经16S rRNA基因序列分析鉴定为丛毛单胞菌(Comamonas sp.),并命名为ZD3。分别考察了培养液pH值和2？策拎ぜ姿岢跏贾柿颗ǘ榷？ZD3降解性能的影响,发现该菌株可在pH值为5.0～9.0的范围内降解2？策拎ぜ姿？,其中7？？0为其最适pH值;当2-吡啶甲酸初始质量浓度分别为100、200、400、600和800 mg？L-1时,ZD3对其完全降解的时间相应为12、17、20、78和114 h。零级动力学模型可比一级动力学模型更好地描述ZD3对2-吡啶甲酸的降解特性,当2？策拎ぜ姿岬某跏贾柿颗ǘ任？100～400 mg？L-1时,降解速率常数k0随着浓度的增加而增大,并在400 mg？L-1时达到最大值;当初始质量浓度为600～800 mg？L-1时,k0开始下降,呈现抑制作用。紫外光谱和高效液相色谱？怖胱于濯卜尚惺奔渲势妆砻？,在2-吡啶甲酸的好氧生物降解过程中,第一步反应为α羟基化反应,产物为6？掺腔？吡啶甲酸。
A strain which uses 2？？picolinic acid as the sole source of carbon, nitrogen and energy was isolated under aerobic condition. Based on 16S rRNA sequence analysis, this strain was identified as Comamonas sp. and named as ZD3. The effects of pH and initial concentrations of 2？？picolinic acid on the degrading capacity of ZD3 were investigated. It was found that ZD3 could degrade 2？？picolinic acid effectively in a pH value range of 5.0？？9.0, wherein 7.0 was proved to be the optimal pH value. When the initial concentration of 2？？picolinic acid was 100, 200, 400, 600 and 800 mg？L-1, ZD3 could completely degrade 2？？picolinic acid within 12, 17, 20, 78 and 114 h, respectively. And zero？？order kinetic model could better express the degradation behavior of 2？？picolinic acid by ZD3 than first？？order kinetic model. It was observed that in the concentration range of 100？？400 mg？L-1, the degradation rate constant (k0) increased with the concentration and reached the maximum at 400 mg？L-1. However, in the concentration range of 600？？800 mg？L-1, k0 began to decrease, indicating an inhibitory effect. Moreover, ultraviolet spectrum and high performance liquid chromatography？？ion trap？？time of flight mass spectrometry showed that in the aerobic degradation of 2？？picolinic acid, the first reaction was α hydroxylation so that 6？？hydroxy picolinic acid was produced