Arsenic tolerance and bioleaching from realgar based on response surface methodology by Acidithiobacillus ferrooxidans isolated from Wudalianchi volcanic lake, northeast China

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• 作者：Lei Yan^a ; ^{yanlei@byau.edu.cn} ; Huixin Hu^a ; Shuang Zhang^a ; Peng Chen^b ; Weidong Wang^a ; Hongyu Li^b
• 关键词：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
• 刊名：Electronic Journal of Biotechnology
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：25
• 期：Complete
• 页码：50-57
• 全文大小：988 K
• 卷排序：25

文摘

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.ResultsAn 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. 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.ConclusionFrom this work we 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.