Division of Biotechnology, Advanced Institute of Environment and Bioscience, College of Environmental and Bioresource Sciences, Chonbuk National University, Iksan 570-752, South Korea.
Department of Agricultural Biology, College of Agriculture & Life Sciences, Chonbuk National University, Jeonju 561-756, South Korea.
Chemosphere. 2014 Aug;109:42-8. doi: 10.1016/j.chemosphere.2014.02.054. Epub 2014 Apr 5.
This study was aimed at assess the potential of diazotrophic bacteria, Herbaspirillum sp. GW103, for bioleaching of Cu in mine soil. The strain exhibited resistance to As (550mgL(-1)), Cu (350mgL(-1)), Zn (300mgL(-1)) and Pb (200mgL(-1)). The copper resistance was further confirmed by locating copA and copB genes. The survival of the isolate GW103 during bioleaching was analyzed using green fluorescent protein tagged GW103. Response surface methodology based Box-Behnken design was used to optimize the physical and chemical conditions for Cu bioleaching. Five significant variables (temperature, incubation time, CaCO3, coconut oil cake (COC), agitation rate) were selected for the optimization. Second-order polynomials were established to identify the relationship between Cu bioleaching and variables. The optimal conditions for maximum Cu bioleaching (66%) were 30°C, 60h of incubation with 1.75% of CaCO3 and 3% COC at 140rpm. The results of Cu sequential extraction studies indicated that the isolate GW103 leached Cu from ion-exchangeable, reducible, strong organic and residual fractions. Obtained results point out that the isolate GW103 could be used for bioleaching of Cu from mine soils.
本研究旨在评估固氮菌 Herbaspirillum sp. GW103 对矿区土壤中铜的生物浸出潜力。该菌株对砷（550mgL(-1))、铜（350mgL(-1))、锌（300mgL(-1))和铅（200mgL(-1))具有抗性。通过定位 copA 和 copB 基因进一步证实了铜的抗性。使用绿色荧光蛋白标记的 GW103 分析了该分离株 GW103 在生物浸出过程中的存活情况。基于响应面法的 Box-Behnken 设计用于优化铜生物浸出的物理和化学条件。选择了五个重要变量（温度、孵育时间、CaCO3、椰子油饼（COC)、搅拌速度）进行优化。建立了二次多项式来确定铜生物浸出与变量之间的关系。最大铜生物浸出（66%)的最佳条件为 30°C、孵育 60 小时、CaCO3 为 1.75%、COC 为 3%、转速为 140rpm。铜连续提取研究的结果表明，分离株 GW103 从可交换离子、可还原、强有机和残余部分浸出了铜。研究结果表明，分离株 GW103 可用于从矿山土壤中浸出铜。
