Biological attack of pyrite is a potential method of reducing pyritic sulphur in coal. Integration of such attacks with microwave pretreatment can enhance the efficiency of the process. Alternatively, processes such as oil-agglomeration can be coupled with the biological attack to obtain higher rates of pyritic sulphur removal. In this study desulphurization of Indian (Assam) coal was carried o...

Different strains of Thiobacillus ferrooxidans and Thiobacillus thiooxidans were used to catalyze the oxidative dissolution of iron pyrite, FeS(2), in nine different coal samples. Kinetic variables and parametric factors that were determined to have a pronounced effect on the rate and extent of oxidative dissolution at a fixed Po(2) were: the bacterial strain, the nitrogen/phosphorus molar rati...

Here we describe artificial help for the respiratory electron flow supporting anaerobic growth of Thiobacillus ferrooxidans through exogenous electrolysis. Flux between H(2) and a anode through cells was accomplished with electrochemical regeneration of iron. The electrochemical help resulted in a 12-fold increase in yield compared with the yield observed in its absence.

Bacterial adhesion to mineral surfaces plays an important role not only in bacterial survival in natural ecosystems, but also in mining industry applications. Selective adhesion was investigated with Thiobacillus ferrooxidans by using four minerals, pyrite, quartz, chalcopyrite, and galena. Escherichia coli was used as a control bacterium. Contact angles were used as indicators of hydrophobicit...

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...

Formate-grown cells of the obligately chemolithoautotrophic acidophile Thiobacillus ferrooxidans were capable of formate- and elemental sulfur-dependent reduction of ferric iron under anaerobic conditions. Under aerobic conditions, both oxygen and ferric iron could be simultaneously used as electron acceptors. To investigate whether anaerobic ferric iron respiration by T. ferrooxidans is an ene...

Glucose-6-phosphate dehydrogenase was partially purified from both glucose-grown and iron-glucose-grown Thiobacillus ferrooxidans. The enzyme possesses a dual nucleotide specificity for either nicotinamide adenine dinucleotide phosphate (NADP) or nicotinamide adenine dinucleotide (NAD) and has a molecular weight of 110,000 as determined by gel electrophoresis. Evidence is presented that T. ferr...

The obligately autotrophic acidophile Thiobacillus ferrooxidans was grown on elemental sulfur in anaerobic batch cultures, using ferric iron as an electron acceptor. During anaerobic growth, ferric iron present in the growth media was quantitatively reduced to ferrous iron. The doubling time in anaerobic cultures was approximately 24 h. Anaerobic growth did not occur in the absence of elemental...