Although Thiobacillus ferrooxidans and Leptospirillum ferrooxidans are widely considered to be the microorganisms that control the rate of generation of acid mine drainage, little is known about their natural distribution and abundance. Fluorescence in situ hybridization studies showed that at Iron Mountain, California, T. ferrooxidans occurs in peripheral slime-based communities (at pH over 1....

A rapid and sensitive spectrophotometric procedure was developed for monitoring the growth of Thiobacillus ferrooxidans in liquid culture. Values determined for the optical densities at 500 nm of washed T. ferrooxidans cell suspensions were directly proportional to both total cell number and total cell protein concentration and provided an accurate measurement of culture growth rate. The utilit...

Thiobacillus ferrooxidans is a gram-negative, highly acidophilic (pH 1.5 to 2.0), autotrophic bacterium that obtains its energy through the oxidation of ferrous iron or reduced inorganic sulfur compounds. It is usually dominant in the mixed bacterial populations that are used industrially for the extraction of metals such as copper and uranium from their ores. More recently, these bacterial con...

Ni2+, Fe2+ and Cu2+ were attractants and aspartate was an apparent repellent for Leptospirillum ferrooxidans, a behaviour opposite to that for Escherichia coli. Membranes from L. ferrooxidans contained proteins with a molecular mass in the range of 80 kDa which were methylated in vitro. Methylation was stimulated in the presence of a membrane-free extract from E. coli, showing the response patt...

The type strain (ATCC 23270) and two other strains of Thiobacillus ferrooxidans were able to grow by hydrogen oxidation, a feature not recognized before. When cultivated on H2, a hydrogenase was induced and the strains were less extremely acidophilic than during growth on sulfidic ores. Cells of T. ferrooxidans grown on H2 and on ferrous iron showed 100% DNA homology. Hydrogen oxidation was not...

Acidithiobacillus ferrooxidans ILS-2 was adapted in digested sludge and used to treat for dewaterability improvement. Results showed that increasing ferrous iron loading increased dewaterability, but the inoculation of bioleaching strain had little effect on compared controls without strain. The total extracellular polymeric substances (EPS) contents sludges with treatment were similar except a...

Production of sulfur globules during sulfide or thiosulfate oxidation is a characteristic feature of some sulfur bacteria. Although their generation has been reported in Acidithiobacillus ferrooxidans, its mechanism of formation and deposition, as well as the physiological significance of these globules during sulfur compounds oxidation, are currently unknown. Under oxygen-sufficient conditions...

The tolerance and bioremoval of dimethylarsinic acid (DMA(V)) by Acidithiobacillus ferrooxidans (A. ferrooxidans) were investigated here. The inhibitory concentration (IC) of DMA(V) was determined for A. ferrooxidans. The effects of various parameters such as pH, contact time, initial DMA(V) concentration, biosorbent dose and temperature were systematically examined to study the biosorption pro...

The iron-oxidizing bacteria Acidithiobacillus ferrooxidans is an example of strictly chemolitotrophic extremophile occurring in acidic environments. The prime niche of these microorganisms is an environment with low pH and high concentrations of iron, sulfide minerals or sulfur. Besides these environments, A. ferrooxidans is also isolated from heavy metal contaminated environments such as soil ...

The utility of employing biogenerated ferric iron as an oxidant for the recycling of scrap metal has been demonstrated using continuously growing cells of the extremophilic organism Acidithiobacillus ferrooxidans. A ferric iron rich (70 mol%) lixiviant resulting from bioreactor based growth of A. ferrooxidans readily solubilized target scrap metal with the resultant generation of a leachate con...