Acidithiobacillus ferrooxidans strain D3-2, which has a high copper bioleaching activity, was isolated from a low-grade sulfide ore dump in Chile. The amounts of Cu(2+) solubilized from 1% chalcopyrite (CuFeS(2)) concentrate medium (pH 2.5) by A. ferrooxidans strains D3-2, D3-6, and ATCC 23270 and 33020 were 1360, 1080, 650, and 600 mg x l(-1) x 30 d(-1). The iron oxidase activities of D3-2, D3...

At the industrial scale, bioleaching of metal sulfides includes two main technologies, tank leaching and heap leaching. Fluctuations in temperature caused by the exothermic reactions in a heap have a pronounced effect on the growth of microbes and composition of mixed microbial populations. Currently, little is known on the influence of pre-colonized mesophiles or moderate thermophiles on the a...

Acidophile bacteria belonging to the Acidithiobacillus genus are pivotal players for the bioleaching of metallic values such as copper. Cell adherence to ores and biofilm formation, mediated by the production of extracellular polymeric substances, strongly favors bioleaching activity. In recent years, the second messenger cyclic diguanylate (c-di-GMP) has emerged as a central regulator for biof...

Abstract Bauxite residue (BR) is the main by-product of alkaline production alumina from bauxite containing significant amounts valuable metals such as scandium that belongs to rare-earth elements (REEs), classified by European Community critical raw materials (CRMs). BR considered a hazardous waste due its huge volume and high alkalinity making disposal serious universal environmental problem....

Kaolin is a naturally occurring raw material for several industrial applications. Moreover, the economy of using has some restrictions due to presence iron-bearing impurities in form oxides and hydroxides. This negative effect on whiteness refractoriness products production high purity ceramics. The application microbial leaching been regarded as cheap bio-friendly than conventional methods, he...

Small (3.5 1) laboratory microcosms containing water, sediment and Elodea canadensis were treated with the herbicides diquat and terbutryne. After treatment total numbers of planktonic bacteria increased significantly by 3-1 1 -fold and heterotroph counts also rose significantly, by 3-23-fold but the population increases of exoenzyme-producing bacteria (3-1 13-fold) were not always significant....

The mechanisms by which microbes interact in communities remain poorly understood. Here, we interrogated specific interactions between photoautotrophic and heterotrophic members of a model consortium to infer mechanisms that mediate metabolic coupling and acclimation to partnership. This binary consortium was composed of a cyanobacterium, Thermosynechococcus elongatus BP-1, which supported grow...

The Mouteh refractory pyrite concentrates at pulp densities of 1.5%, 3%, 4.5% and 6% were treated, using Thiobacillus ferrooxidans DSM 581 and the same bacteria adapted on the Mouteh pyritic concentrate. Compared with a non-adapted culture, use of an adapted inoculum of T. ferrooxidans increased bioleaching rate of iron by a factor of 1.940, 2.011, 1.859 and 1.559 for pulp densities 1.5%, 3%, 4...

Soil contamination by heavy metals through the application of a phosphate fertilizer is key issue for sustainable agriculture. Among contaminants, cadmium (Cd) considered most hazardous to human beings’ health and surrounding environment. X-ray diffraction (XRD), combined with binocular mineralogical analysis chemical analysis, was used determine C(I) C(II) layers’ composition. In (+71 µm)-size...