摘要
In this paper,Sulfobacillus thermosulfidooxidans ST was selected for use in bioleaching of pyrite and chalcopyrite.The adsorption experiments revealed that more cells were adsorbed on the surface of pyrite than on the surface of chalcopyrite.The role of extracellular DNA(eDNA)in the bioleaching process was investigated by depletion of eDNA using DNase I.The number of cells attached on the chalcopyrite and pyrite surfaces decreased on a large scale,and the lag phase of cell growth increased,causing the leaching percentages of pyrite and chalcopyrite to decrease by approximately 11.6%and 20.5%,respectively.The formation and distribution of eDNA secreted during bioleaching was assessed by a fluorescent dye-based method and visualized by confocal laser scanning microscopy(CLSM).The content of eDNA increased with bioleaching time.Furthermore,ST showed a stronger capacity to produce eDNA on the surface of pyrite than on the surface of chalcopyrite.These results showed that the removal of eDNA has a more significant effect on the bioleaching of chalcopyrite than on pyrite.
选取Sulfobacillus thermosulfidooxidans ST用于黄铁矿和黄铜矿的生物浸出实验。吸附实验表明,相较于黄铜矿,细菌更多地吸附在黄铁矿的表面。实验使用DNaseI特异性去除胞外DNA(eDNA)来研究e DNA在生物浸出过程中的作用,eDNA的缺失使吸附在黄铜矿和黄铁矿表面的细菌数量大量减少,菌种生长周期延长,并且黄铁矿和黄铜矿的最终浸出率分别降低了11.6%和20.5%。同时,基于荧光染料的方法评估生物浸出过程中分泌的eDNA的形成和分布,并选择共聚焦激光扫描显微镜(CLSM)可视化了矿物表面的吸附菌和e DNA。eDNA的产量随着生物浸出时间的延长而增加。此外,吸附在黄铁矿表面的ST菌比吸附在黄铜矿表面的Sulfobacillus thermosulfidooxidansST菌有更高的e DNA产量。综上结果表明,eDNA的去除对黄铜矿的生物浸出比对黄铁矿的生物浸出具有更大的影响。
基金
Projects(31470230,51320105006,51604308)supported by the National Natural Science Foundation of China
Project(2017RS3003)supported by the Youth Talent Foundation of Hunan Province of China
Project(2018JJ2486)supported by the Natural Science Foundation of Hunan Province of China
Project(2018WK2012)supported by the Key Research and Development Projects in Hunan Province,China。
