Abstract: The mixed culture of acidophilic bacteria was used as the inoculant to bioleach waste printed wire boards. Meanwhile, bacteria in different leaching phases (0, 5, 24 and 60 h) were sampled, and denaturing gradient gel electrophoresis (DGGE) analysis of polymerase chain reaction (PCR)-amplified 16Sr RNA genes was used to evaluate the change of microbial community structure during the bioleaching process. The results showed that the mixed culture of acidophilic bacteria could bioleach 96.36 % copper from the boards in 48 h. The analysis of the bands selected from the DGGE gel revealed that the sequences of seven bands (Z1~Z7) had over 99% sequence similarity with Acidithiobacillus ferrooxidans. It meant that the seven strains were all clustered to Acidithiobacillus ferrooxidans genus. The relative abundance of Z1 to Z7 in the four samples was not changed significantly. Meanwhile, Z3 showed the highest relative abundance during the whole bioleaching process, which was 72.70%, 82.90%, 79.00% and 85.80%, respectively. Therefore, the microbial community structure changed a little bit during the bioleaching, which always consisted of Acidithiobacillus ferrooxidans strains and was dominated by strain Z3.

Key words: acidophilic bacteria, waste printed wire boards, bioleaching, polymerase chain reaction-denaturing gradient gel electrophoresis, microbial community structure

摘要： 以富集的嗜酸性细菌为接种物，进行废旧线路板的生物浸出实验，同时收集浸出不同时间的微生物样品，利用聚合酶链式反应-变性梯度凝胶电泳技术分析了浸出过程中微生物群落结构的变化. 结果表明，嗜酸性细菌能在48 h内浸出废旧线路板中96.36%的铜. 从变性梯度凝胶上挑选的明亮条带分析结果显示，Z1~Z7七个条带序列与氧化亚铁硫杆菌(Acidithiobacillus ferrooxidans)的序列同源性均在99%以上，即均为Acidithiobacillus ferrooxidans. 浸出0, 5, 24和60 h的样品中Z1~Z7的组成比例变化不大，其中Z3相对丰度一直最高，分别为72.70%, 82.90%, 79.00%和85.80%. 浸出过程中微生物群落结构演变较平缓，始终为Acidithiobacillus ferrooxidans菌群，菌株Z3是整个浸出过程中的优势菌种.

关键词: 嗜酸性细菌, 废旧线路板, 生物浸出, 聚合酶链式反应变性梯度凝胶电泳, 微生物群落结构