Gold Bioaccumulation by Filamentous Soil Cyanobacteria isolated from Mouteh Goldmine (Isfahan Province, Iran)

This study was aimed to investigate the possible exploitation of phototrophic microorganisms for the oxidation of Au3+ containing composites as well as recovery and bioaccumulation of Au3+ from Mouteh goldmine soil samples. Mechanisms of accumulation including oxidation, dissolution, reduction, leaching and sorption were investigated. After 3 weeks of cyanobacterial growth, gold bioaccumulation from Mouteh gold mine soil solution were determined. Then biomass digested with acidic solutions and subsequently gold amounts were analyzed with Atomic Absorption Spectroscopy. Soil sample with 2 ppm Au3+containing composites ore from Mouteh goldmine were collected. At the end of experiments, the concentration of gold in biomass was almost 6.5 ppm. Results indicated that two soil cyanobacteria species from Mouteh goldmine could bind gold in gold bio-mining process. Bioaccumulation percent was 32% and 30% for Phormidium tenue Gomont and Osillatoria tenuis C. Agardh ex Gomont respectively. Cyanobacterial gold accumulation were determined 6.5 gr/kg biomass dried weight.