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Electronic Journal of Biotechnology
Universidad Católica de Valparaíso
ISSN: 0717-3458
Vol. 25, No. 1, 2017, pp. 50-57
Bioline Code: ej17009
Full paper language: English
Document type: Research Article
Document available free of charge

Electronic Journal of Biotechnology, Vol. 25, No. 1, 2017, pp. 50-57

 en Arsenic tolerance and bioleaching fromrealgar based on response surface methodology by Acidithiobacillus ferrooxidans check for this species in other resources isolated from Wudalianchi volcanic lake, northeast China
Yan, Lei; Hu, Huixin; Zhang, Shuang; Chen, Peng; Wang, Weidong & Li, Hongyu

Abstract

Background: Traditional methods of obtaining arsenic have disadvantages such as high cost and high energy consumption. Realgar is one of the most abundant arsenic sulphide minerals and usually treated as waste in industry. The aim of the present study was to screen an arsenic tolerant bacterium used for bioleaching arsenic from realgar.
Results: An acidophilic iron-oxidizing bacterium BYQ-12 was isolated from Wudalianchi volcanic lake in northeast China. BYQ-12 was a motile, rod-shaped gram-negative bacterium with an optimum growth at 30°C and pH 2.5. 16S rDNA phylogeny showed that BYQ-12 was a new strain of Acidithiobacillus ferrooxidans check for this species in other resources . The inhibitory concentrations (ICs) of arsenite and arsenate were 32 and 64 mM, respectively. A significant second-order model was established using a Box–Behnken design of response surface methodology (BBD-RSM) and it estimated that a maximum arsenic bioleaching rate (73.97%) could be obtained when the pulp concentration, pH and initial ferrous ion concentration were set at optimized values of 0.95% w/v, 1.74 and 3.68 g/L, respectively. SEM, EDS and XRD analyses also revealed that there was direct bioleaching besides indirect electrochemical leaching in the arsenic bioleaching system.
Conclusion: Fromthis workwe were successful in isolating an acidophilic, arsenic tolerant ferrous iron-oxidizing bacterium. The BBD-RSM analysis showed that maximum arsenic bioleaching rate obtained under optimum conditions, and the most effective factor for arsenic leaching was initial ferrous ion concentration. These revealed that BYQ-12 could be used for bioleaching of arsenic from arsenical minerals.

Keywords
16S rDNA phylogeny; Arsenic bioleaching; Arsenic sulphide minerals; Arsenic-resistance; China; EDS analyses; Iron-oxidizing bacterium; Isolation acidophilic bacterium; Realgar bioleaching; Response surface methodology; SEM analyses

 
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