两株壬基酚和双酚A高效降解菌株的筛选和降解特性

Isolation and Identification Characteristics of Two Bacterium Strains for Degradation of NP and BPA

以桂林市上窑污水处理厂污泥脱水车间剩余污泥、上窑堆肥厂的堆肥堆料和桂林雁山镇森林土壤为菌源进行驯化,分离纯化并筛选得到2株能分别以壬基酚(NP)和双酚A(BPA)为唯一碳源和能源生长的降解菌株N-1和B-1。通过对菌株的16S r DNA序列同源性分析,初步鉴定N-1和B-1菌分别为Cupriavidus(贪铜菌属)、Acinetobacter(不动杆菌属)。通过两菌株分别降解NP和BPA的单因素实验,确定了降解动力学以及时间、温度、p H值对降解过程的影响。研究结果表明,细菌N-1,B-1的最佳初始目标污染物质量浓度为5~10 mg/L,降解40 h,N-1去除率可达49.63%,B-1去除率可达62.34%。细菌N-1对NP的去除半衰期t1/2为41.44~48.02 h;B-1对BPA的去除半衰期t1/2为35.23~37.33 h。细菌N-1,B-1的最佳降解温度均为30℃,最佳p H值均在6.5~7.5之间,即两种细菌在中温、中性条件下对NP和BPA降解效果最佳。

Two kinds of bacteria, numbered as N - 1 and B - 1, could use NP and BPA as the sole carbon and energy source respectively, they were domesticated and purified from the sewage sludge, compost, and soil obtained from the sludge dewatering workshop of Shangyao Wastewater Treatment Plant, Shangyao Composting Plant, and Yanshan Forest in Guilin, respectively. According to the results of their sequence analysis of 16S rDNA, these two kinds of bacteria were identified as Cupriavidus and Acinetobacter respectively. By doing single factor experiments, the effects of time, temperature and pH on the degradation were determined. The research results show that the best initial target pollutants concentration of N - 1 and B - 1 is about 5 - 10 mg/L, and the removal rate of N - 1 and B - 1 can be 49.63% and 62.34% respectively. The half - value period of N - 1 for removal of NP is about 41.44 ~48.02 h, while B - 1 is about 35.23 - 37.33 h. The optimal conditions for degradations of NP and BPA by each bacterial both were 30℃ and initial pH 6.5 ~ 7.5. In other words, in the conditions of the medium temperature and neutral condition, the degradation of the two kinds of bacteria on NP and BPA is the most effective.