壬基酚和双酚A降解菌株的分离、鉴定和特性研究

Isolation,identification and characteristics of a bacterial strain for the simultaneous biodegradation of nonylphenol and bisphenol A

对深圳某污水处理厂反硝化除磷活性污泥进行驯化,分离筛选得到一株能同时降解壬基酚(NP)和双酚A(BPA)的菌株NB-1.根据对菌株的16S rRNA基因序列分析,结合菌落和菌体形态以及生理生化特征,初步鉴定菌株NB-1为Serratia marcescens(粘质沙雷菌).通过摇瓶试验进行了菌株降解条件的优化和降解特性的探索.结果表明,菌株NB-1降解NP和BPA的最佳条件为:醋酸钠投加量为20 mg·L-1,温度为32℃,pH值为8,接种量为2%,在该条件下,对菌株降解不同初始浓度NP和BPA的过程进行了动力学分析,结果表明,降解反应前36 h符合一级反应动力学.NP和BPA降解的最适初始浓度为10～20 mg·L-1,当底物浓度均为10 mg·L-1时,NP和BPA的去除率分别为54.2%、44.7%,BPA的去除率达到最大值;当底物浓度均为20 mg·L-1时,NP和BPA的去除率分别为56.4%、40.2%,此时NP的去除率达到最大值.

The bacterial strain, NB-1, capable of degrading nonylphenol （NP） and bisphenol A （BPA） simultaneously, was isolated from the denitrifying phosphorus removal device of Shenzhen Wastewater Treatment Plant. Strain NB- 1 was preliminarily identified as Serratia marcescens, according to the analysis of 16S rRNA gene sequence and its morphological, physiological and biochemical characteristics. The results showed that the optimal conditions for the degradation of NP and BPA by strain NB-I were initial optimum content of sodium acetate 20 mg·L^-1 , temperature 32℃ , initial pH 8, and inoculum amount 2%. According to the kinetics analysis of the degradation of NP and BPA by strain NB-1 under different initial NP and B PA concentrations, the degradation reaction was consistent wilh first - order kinetics, and the optimum initial NP and BPA concentrations were 10 -20 mg·L^-1. The degradation rate of NP and BPA was 54.2% and 44.7% , respectively, after 36 h at the initial NP and BPA concentration of 10mg·L^-1 , and 56.4% and 40.2% , respectively, at the initial concentration of 20 mg·L^-1.