一株对硝基苯酚降解菌的筛选鉴定及其降解特性

摘要

从受甲基对硫磷污染的土壤中分离筛选得到一株能够以对硝基苯酚(PNP)作为唯一碳源、氮源生长的菌株,命名为TM.经16S rDNA序列分析初步鉴定该菌株为节杆菌(Arthrobacter).考察了该菌株在PNP浓度、盐度(NaCl)、pH、外加碳源(葡萄糖)、外加氮源等因素下对PNP降解特性的影响.结果表明:该菌株对PNP的最大耐受质量浓度为300 mg/L,并在降解的过程中生成NO2-该菌株的耐盐能力可达0.30％(质量分数),其最佳pH为8.在此pH下,200 mg/L的PNP在16h时即可被完全降解,添加0.30％(质量分数)的葡萄糖可使生物量和降解速率达到最大,牛肉膏作为外加氮源最有利于该菌株对PNP的降解.%A p-nitrophenol degrading strain, named TM, was isolated from the parathion-methyl contaminated site. TM could utilize PNP as the sole carbon and nitrogen source during the cultivation. Based on the result of 16S rDNA gene sequences, the strain was preliminary designated as Arhtrobacter. Batch of experiments were carried out to investigate the effect of PNP and glucose concentration, salinity, pH and nutrition on the PNP degrading performance. Results showed that the maximum tolerant dose of TM to PNP was 300 mg/L, and the degradation was accompanied by the generation of NO2- . The strain could growth well even the salinity up to 0. 30% (mass fraction), and the greatest growth of TM was observed at a pH of 8. At this pH value,PNP at the concentration of 200 mg/L could be degraded completely in 16 h. The biomass and degradation rate of TM reached to the peak with the existence of 0. 30% glucose. Beef extract was found to be the most beneficial supplemental nitrogen to the strain on PNP degradation.