Inhibition of growth, iron, and sulfur oxidation in Thiobacillus ferrooxidans by simple organic compounds

1976 ◽  
Vol 22 (5) ◽  
pp. 719-730 ◽  
Author(s):  
Jon H. Tuttle ◽  
Patrick R. Dugan
Keyword(s):  
Organic Compounds ◽  
Ferrous Iron ◽  
Thiobacillus Ferrooxidans ◽  
Cell Envelope ◽  
Iron Oxidation ◽  
Inorganic Ions ◽  
Sulfur Oxidation ◽  
Physical Treatment ◽  
Inhibition Of Growth ◽  
Iron And Sulfur Oxidation

Iron and sulfur oxidation by Thiobacillus ferrooxidans as well as growth on ferrous iron were inhibited by a variety of low molecular weight organic compounds. The influences of chemical structure of the organic inhibitors, pH, temperature, physical treatment of cells, and added inhibitory or stimulatory inorganic ions and iron oxidation suggest that a major factor contributing to the inhibitory effects on iron oxidation is the relative electronegativity of the organic molecule. The data also suggest that inhibitory organic compounds may (i) directly affect the iron-oxidizing enzyme system, (ii) react abiologically with ferrous iron outside the cell, (iii) interfere with the roles of phosphate and sulfate in iron oxidation, and (iv) nonselectively disrupt the cell envelope or membrane.

scholarly journals Selective Inhibition of the Oxidation of Ferrous Iron or Sulfur in Thiobacillus ferrooxidans

2000 ◽  
Vol 66 (3) ◽  
pp. 1031-1037 ◽  
Author(s):  
Lesia Harahuc ◽  
Hector M. Lizama ◽  
Isamu Suzuki
Keyword(s):  
Osmotic Pressure ◽  
Ferrous Iron ◽  
Thiobacillus Ferrooxidans ◽  
Iron Oxidation ◽  
Sulfur Oxidation ◽  
Selective Inhibition ◽  
Inhibitory Effect ◽  
Low Concentrations ◽  
Chloride Leaching ◽  
Higher Sensitivity

ABSTRACT The oxidation of either ferrous iron or sulfur byThiobacillus ferrooxidans was selectively inhibited or controlled by various anions, inhibitors, and osmotic pressure. Iron oxidation was more sensitive than sulfur oxidation to inhibition by chloride, phosphate, and nitrate at low concentrations (below 0.1 M) and also to inhibition by azide and cyanide. Sulfur oxidation was more sensitive than iron oxidation to the inhibitory effect of high osmotic pressure. These differences were evident not only between iron oxidation by iron-grown cells and sulfur oxidation by sulfur-grown cells but also between the iron and sulfur oxidation activities of the same iron-grown cells. Growth experiments with ferrous iron or sulfur as an oxidizable substrate confirmed the higher sensitivity of iron oxidation to inhibition by phosphate, chloride, azide, and cyanide. Sulfur oxidation was actually stimulated by 50 mM phosphate or chloride. Leaching of Fe and Zn from pyrite (FeS2) and sphalerite (ZnS) by T. ferrooxidans was differentially affected by phosphate and chloride, which inhibited the solubilization of Fe without significantly affecting the solubilization of Zn.

How the RegBA Redox Responding System Controls Iron and Sulfur Oxidation in Acidithiobacillus ferrooxidans

2013 ◽  
Vol 825 ◽  
pp. 186-189 ◽  
Author(s):  
Danielle Moinier ◽  
Deborah Byrne ◽  
Agnès Amouric ◽  
Violaine Bonnefoy
Keyword(s):  
Acidithiobacillus Ferrooxidans ◽  
Ferrous Iron ◽  
Iron Oxidation ◽  
Regulatory Region ◽  
Sulfur Oxidation ◽  
Sulfur Compounds ◽  
Chemical Attack ◽  
Valuable Metals ◽  
Genes Encoding ◽  
Iron And Sulfur Oxidation

Valuable metals as well as ferrous iron and sulfur compounds are released from ore by ferric iron and sulfuric acid chemical attack. Biomining microorganisms allow the recycling of these products by oxidizing ferrous iron and/or sulfur compounds. The energy released from the oxidation of these substrates is used for the growth of the acidophilic chemolithoautotrophic bacterium Acidithiobacillus ferrooxidans. The respiratory pathways involved in these respiratory processes have been deciphered and the expression of the genes encoding these redox proteins is dependent on the electron donor present in the medium. Furthermore, in the presence of both ferrous iron and sulfur, the genes involved in iron oxidation are expressed before those involved in sulfur oxidation. We propose that the global redox responding two component system RegBA is responsible for this regulation since (i) the redox potential increases during iron oxidation but remains stable during sulfur oxidation and (ii) the transcriptional regulator RegA binds the regulatory region of a number of genes/operons involved in iron and sulfur oxidation. To understand the mechanism of the At. ferrooxidans RegBA system, the regA gene and the DNA corresponding to the DNA binding domain of RegA were cloned in an expression plasmid in Escherichia coli. The recombinant proteins, RegA and RegA-HTH respectively, were purified. The binding of RegA-HTH, phosphorylated and unphosphorylated RegA on the regulatory region of some target operons have been compared by gel shift mobility assay.

Effects of the oxygen transfer rate on ferrous iron oxidation by Thiobacillus ferrooxidans

1998 ◽  
Vol 23 (7-8) ◽  
pp. 427-431 ◽  
Author(s):  
D.S Savić ◽  
V.B Veljković ◽  
M.L Lazić ◽  
M.M Vrvić ◽  
J.I Vučetić
Keyword(s):  
Oxygen Transfer ◽  
Ferrous Iron ◽  
Transfer Rate ◽  
Thiobacillus Ferrooxidans ◽  
Iron Oxidation ◽  
Oxygen Transfer Rate ◽  
Ferrous Iron Oxidation

OXIDATION OF INORGANIC SULFUR COMPOUNDS BY WASHED CELL SUSPENSIONS OF THIOBACILLUS FERROOXIDANS

1966 ◽  
Vol 12 (5) ◽  
pp. 957-964 ◽  
Author(s):  
J. Landesman ◽  
D. W. Duncan ◽  
C. C. Walden
Keyword(s):  
Organic Compounds ◽  
Elemental Sulfur ◽  
Thiobacillus Ferrooxidans ◽  
Sulfur Oxidation ◽  
Sulfur Compounds ◽  
Maximum Temperature ◽  
Washed Cell ◽  
Inorganic Sulfur ◽  
Respiration Rates ◽  
Growth Adaptation

Oxidation of various inorganic sulfur compounds by Thiobacillus ferrooxidans was studied, and conditions necessary for maximum respiration rates were established. Optimum oxidation of elemental sulfur occurred at pH 5.0 and gave a Qo2(N) of 726; oxidation of thiosulfate gave a maximum Qo2(N) of 514 at pH 4.0; tetra- and tri-thionate, when oxidized at pH 6.0, gave a maximum Qo2(N) of 103 and 113, respectively. Polythionates accumulated during thiosulfate oxidation, but did not during oxidation of elemental sulfur. Metallic sulfide minerals were oxidized optimally as follows: chalcopyrite, pH 2.0, maximum Qo2(N) 3200; bornite, pH 3.0, maximum Qo2(N) 450; pyrite, pH 2.0, maximum Qo2(N) 1600. Maximum temperature for oxidation of all inorganic sulfur compounds tested was 40 C.The effect of a variety of organic compounds on sulfur oxidation is presented.T. ferrooxidans requires growth adaptation on iron for maximum respiration on that substrate; however, sulfur oxidation is not inducible. Iron and sulfur can be oxidized simultaneously, giving a rate equal to the sum of the maximum rates of oxidation of the two substrates individually.

ROLE OF THIOBACILLUS FERROOXIDANS IN THE OXIDATION OF SULFIDE MINERALS

1967 ◽  
Vol 13 (4) ◽  
pp. 397-403 ◽  
Author(s):  
D. W. Duncan ◽  
J. Landesman ◽  
C. C. Walden
Keyword(s):  
Oxygen Uptake ◽  
Sodium Azide ◽  
Ferrous Iron ◽  
Thiobacillus Ferrooxidans ◽  
Sulfide Oxidation ◽  
Iron Oxidation ◽  
Rapid Rate ◽  
Total Oxygen ◽  
Washed Cell

Selective inhibitors of iron and sulfide oxidation, sodium azide and N-ethylmaleimide respectively, were used to demonstrate that washed cell suspensions of Thiobacillus ferrooxidans attacked both insoluble ferrous iron and sulfide during the oxidation of chalcopyrite (CuFeS2) and pyrite (FeS2). The oxidation of the two substrates occurred simultaneously and independently but the relative rates depended on how the cells were grown. When chalcopyrite-grown cells were used to oxidize chalcopyrite, 68–74% of the oxygen uptake was the result of sulfide oxidation and 25–30% the result of iron oxidation. With pyrite, all the oxygen uptake was due to sulfide oxidation. When iron-grown cells were used to oxidize chalcopyrite, two rates resulted. During the initial rapid rate, 80–90% of the oxygen uptake was due to iron oxidation, but, during the second slower rate, the result duplicated those found with chalcopyrite-grown cells. Iron-grown cells oxidized pyrite at a constant and more rapid rate than chalcopyrite-grown cells. The faster rate was due to iron oxidation; since only 20–30% of the total oxygen uptake was due to sulfide oxidation.

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