文章采用PCR-直接测序法研究了铀生物堆浸不同浸铀阶段(前期酸化、酸化、前期菌液淋洗、菌液浸铀)微生物群落结构的变化.采用试剂盒法提取了矿石样品中宏基因组DNA,以细菌的16S rDNA通用引物27F/1492R扩增16S rDNA片段,建立16S rDNA克隆文库.从每个处理结果中筛选100个阳性克隆,阳性克隆子直接送测序,用NCBI Blastn程序进行基因数据比对分析,结果表明:从前期酸化阶段到菌液浸出阶段,菌落多样性呈减弱趋势,对浸铀有直接或间接作用的嗜酸性微生物:嗜酸性氧化硫硫杆菌(Acidithiobacillus thiooxidans)、嗜酸性氧化亚铁硫杆菌(Acidithiobacillus ferrooxidans)等的含量呈增加趋势.在菌液浸出阶段,pH值低于最小值1.8时,细菌多样性较高,对浸铀有直接或间接作用的嗜酸性微生物丰度较低.说明嗜酸性微生物对铀的浸出可能有重要作用,生物堆浸过程中需要严格调控pH值.
In this study, PCR-sequencing was adopted to investigate the changes of bio-compound structure on biological heap leaching of uranium in different stages of leaching uranium including pre-acidification, acidification, pre-bacteria leaching and bacteria leaching. Total genomic DNA was extracted by a kit method from five different ore samples, respectively. The 16S rDNA of the extracted DNA were amplified using bacterial universal primers 27F and 1492R and a 16SrDNA clone library was constructed. A total of 100 positive clones were randomly chosen from the clone library to be examined and sequenced directly. Sequences were analysised with NCBI Blastn database. Results indicated that: the bacteria diversity was weakened from pre-acidification stage to bacteria leaching stage, The abundance of acidophilic bacteria, including Acidithiobacillus thiooxidans, Acidithiobacillus ferrooxidans and Su(/bbacillus thermosulfidooxidans and so on, increased as in-situ leaching of uranium proceeded. They play a direct or indirect role on leaching uranium. While when the pH value was lower than 1.8 on bacteria leaching stage, bacterial diversity was high and the abundance metallurgical flora was low, indicating that it might have important functions for microbial leaching of uranium and needs to strictly control pH value in biological heap leaching process.