Microbial Community Structure Dynamics before and after Bioleaching of Copper Pyrites
Microorganisms in AMD (Acid Mine Drainage) were enriched in 9K culture medium. The enrichment was applied to leach copper pyrite after the microbial community structure and metabolism was stable. Before and after bioleaching, the microbial DNA was extracted and applied to RFLP (restricted fragment length polymorphism) analysis to demonstrate the relationship between the leaching efficiency and the change of microbial community. Atomic absorption spectrometry results showed that when concentration of the pulp was 10% and pH were 1.5, 2.0 and 2.5, the leaching rate were 56%, 57% and 34% on the 18th day respectively. These results indicated that the rise of pH resuited in the decrease of leaching rate. In lower pH condition, the growth of microbe was faster:when pH was 1.5, the microbial cell number reached to 1.4×107cells/mL on the 9th day; while pH was 2.5, the microbial cell number decreased to 4×106cells/mL. The analysis of microbial community structure showed that Acidithiobacillus ferrooxidans and Leptospirillura ferrooxidans were dominant species before bioleaching (account for 43% and 32% respectively). And after bioleaching,these two species were still dominant when the initial bioleaching pH werel.5 and 2.0. While the initial bioleaching pH was 2.5, the proportion of these two species decreased. These results demonstrated that the initial bioleaching pH would affect the microbial community structure in bioleaching system at room temperature, and this affect could lead to different copper pyrites bioleaching efficiency.
Microbial community structure Bioleaching Copper pyrite RFLP
Z. M. Dai H. W. Liu H. Q. Yin X. D. Liu
Resource Process and Bioengineering School, Central South University, Changsha,China
国际会议
XXIV International Mineral Processing Congress(第24届国际矿物加工大会)
北京
英文
2794-2800
2008-09-24（万方平台首次上网日期，不代表论文的发表时间）