Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6309055 | Chemosphere | 2014 | 7 Pages |
Abstract
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 (550 mg Lâ1), Cu (350 mg Lâ1), Zn (300 mg Lâ1) and Pb (200 mg Lâ1). 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, 60 h of incubation with 1.75% of CaCO3 and 3% COC at 140 rpm. 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.
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Authors
Muthusamy Govarthanan, Gun-Woong Lee, Jung-Hee Park, Jae Su Kim, Sung-Sik Lim, Sang-Ki Seo, Min Cho, Hyun Myung, Seralathan Kamala-Kannan, Byung-Taek Oh,