高矿浆浓度下黄铜矿浸出过程中微生物群落结构变化规律

目的：为阐明微生物群落演替及功能与浸出效率之间关系奠定基础，以及如何提高黄铜矿生物浸出效率和铜回收率提供理论依据。方法：通过连续传代培养进行驯化，使得复合菌群的矿浆浓度耐受能力达到25 %（w/v）。采用该复合菌群在25 %矿浆浓度下浸出黄铜矿，同时利用变性梯度凝胶电泳和克隆文库技术分析浸出过程中的微生物多样性。最后，采用实时荧光定量PCR 对浸出过程中微生物群落结构进行定量解析。结果：28天内黄铜矿浸出率能够达到95.1 %，而驯化前的浸出率只有51.5%。该复合菌群主要由Acidithiobacillus caldus, Sulfobacillus acidophilus，和Fereoplasma theroplasma thermophilum组成，其中Acidithbacillus caldus是浸出前期和后期的优势种群，而Sulfobacillus acidophilus在浸出中期均有竞争优势， Ferroplasma thermophilum在整个浸出过程中占据整个群落的比例均较低。结论：本研究获得的复合菌群具有较强的浸出黄铜矿能力， Acidithiobacillus caldus和Sulfobacillus acidophilus在浸出过程中起着重要的作用，pH 值和铜浸出率与群落结构相关性较高。

Microbial Community Structure and Dynamics during Bioleaching ofChalcopyrite at High Pulp Density

Objective:To lay the foundation for illumination of the relationship between microbial community dynamics and function and bioleaching efficiency, and provide useful insights into how to improve bioleaching efficiency and recovery of copper.Methods:After adaptation by serial subculturing, a mixed microbial culture was able to tolerate a pulp density of 25 % of chalcopyrite concentrate(w/v). The mixed microbial culture was applied to leach chalcopyrite concentrate at a pulp density of 25 %. Denaturing gradient gel electrophoresisand clone libraries were used to analyze the microbial diversity during bioleaching process, and real-time quantitative PCR was employed to monitor the microbial dynamics.Results:Copper extraction was up to 95.1 %within 28 days, while it was only 51.5 %before adaptation. The mixed microbial culture consisted mainly of three species, including Acidithiobacillus caldus,Sulfobacillus acidophilus, and Ferroplasma thermophilum.Acidithiobacillus caldus was the predominant species in the initial and final stages, while Sulfobacillus acidophilus became the predominant species in the middle stage. Ferroplasma thermophilum always accounted for the lowestproportion during the whole bioleaching process.Conclusion:The mixed microbial culture obtained in this study has a strong ability to bioleach chalcopyrite concentrate. and play significant roles during bioleaching ofchalcopyrite concentrate, Acidithiobacillus caldus and Sulfobacillus acidophilus there are strong correlations between pH or copper extraction and microbial community structure.