硝基苯高效降解菌群对吡啶甲酸的好氧降解

Degradation of Picolinic Acid by a Mixture of Nitrobenzene-assimilating Strains under Aerobic Condition

吡啶甲酸作为副产物出现在硝基苯的部分还原降解途径中,生物毒性更大,阻碍了硝基苯的好氧生物降解。该实验以某染料厂活性污泥为菌源,经富集、筛选,得到以硝基苯为唯一碳、氮源的3株菌:Streptomycesalbidoflavus(微白黄链霉菌),Rhodotorula mucilaginosa和M icrococcus luteus(藤黄微球菌)。考察了由上述三株菌组成的菌群及其完整细胞对吡啶甲酸的降解。结果表明:菌群在好氧条件下以吡啶甲酸为唯一碳、氮源,吡啶甲酸被开环矿化为无害产物CO2和H2O,吡啶甲酸TOC去除率为96%,TN去除率为96%。菌群及其完整细胞对吡啶甲酸的降解过程中均有NH4+的释放并呈上升趋势。

Picolinic acid emerges as a dead-end product in the initial reductive pathway of nitrobenzene degradation. Because of its higher toxicity, the aerobic biodegradation of nitrobenzene is impeded. Activated sludge is obtained from a dyeing-manufacturing facility. After enrichment and filtration, three isolates that could grow on nitrobenzene as a sole source of carbon and nitrogen are gained ： Streptomyces albidoflavus,Rhodotorula mucilaginosa, and Micrococcus luteus. A mixture of strains consisting of the above-mentioned isolates is used to degrade picolinic acid. It shows that the mixture of strains can grow on picolinic acid as the sole source of carbon and nitrogen under aerobic condition, picolinic acid undergoes ring fission and mineralizes to CO2 and H2O, and the removing rate of TOC and TN are both 96%. During degradation of picolinic acid by the mixture of strains and resting cells, NH4 is released with increasing trend.