The aim of this investigation was to determine the efficacy of chalcopyrite bioleaching using pure cultures of Acidithiobacillus ferrooxidans or Acidithiobacillus thiooxidans and a mixed culture composed of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans. The experiments were carried out in shake flasks with [Fe] 4 gL 1 and S 1 gL 1 at pH 1.80, 130 rpm and 30 C. Inocula of both...

Acidithiobacillus albertensis is an extremely acidophilic, mesophilic, obligatory autotrophic sulfur-oxidizer, with potential importance in the bioleaching of sulfidic metal ores, first described in the 1980s. Here we present the draft genome sequence of Acidithiobacillus albertensis DSM 14366T, thereby both filling a long-standing gap in the genomics of the acidithiobacilli, and providing furt...

 Cyanidation is a relatively simple and cheap technology to treat gold-containing ores. However, this process is not completely effective in refractory gold-bearing sulfide ores. In the case of very low-grade ores, biooxidation is an attractive alternative pre-treatment to render the gold amenable to extraction. This process utilizes the ability of acidophilic bacteria to oxidize the sulfide m...

Acidithiobacillus caldus is an extremely acidophilic, moderately thermophilic, chemolithoautotrophic gammaproteobacterium that derives energy from the oxidation of sulfur and reduced inorganic sulfur compounds. Here we present the draft genome sequence of Acidithiobacillus caldus ATCC 51756 (the type strain of the species), which has permitted the prediction of genes for survival in extremely a...

Applicability of the manometric method for studying the oxidation of pyritic material in the presence of bacteria has been demonstrated. Resting cells of Ferrobacillus ferrooxidans accelerated the oxidation of coal pyrites and coarsely crystalline marcasite, but were inactive on coarsely crystalline pyrite. Resting cells of Thiobacillus thiooxidans were inactive on all pyrites tested. Oxidation...

The mining industry is looking forward for bacterial consortia for economic extraction of copper from low-grade ores. The main objective was to determine an optimal bacterial consortium from several bacterial strains to obtain copper from the leach of chalcopyrite. The major native bacterial species involved in the bioleaching of sulphide ore (Acidithiobacillus ferrooxidans, Acidithiobacillus t...

−− Copper recoveries using two methodologies of acid leaching of a low-grade ore are reported in this work. The ore, abounding in oxidized species, was from Barda González reservoir in Neuquén province, Argentina. In the first methodology, cells of Acidithiobacillus thiooxidans were inoculated into a column containing the ore and sulfur as energy source. In the second one, a bioreactor with imm...

Polyphasic genotypic analysis of 25 Acidithiobacillus ferrooxidans strains isolated from ores and ore concentrates collected in different regions of the world showed considerable strain heterogeneity. Restriction patterns of the chromosomal DNA of these strains obtained by PFGE were specific for each strain. According to the degree of DNA relatedness, 17 of the 23 strains studied were divided i...

In the absence of iron, dissolution of zinc sulfide was enhanced by the action of Acidithiobacillus caldus at 40 o C. The bioleaching mechanism was similar to that observed for mesophilic species of Acidithiobacillus at 30 o C, although the final metal recovery was lower. When iron was added to the cultures, the solubilization of zinc and copper from the sulfides was higher than that in sterile...