Effect of amino acids on bioleaching of chalcopyrite ore by Thiobacillus ferrooxidans

ABSTRACT The gene encoding sulfide-quinone reductase (SQR; E.C.1.8.5.′), the enzyme catalyzing the first step of anoxygenic photosynthesis in the filamentous cyanobacterium Oscillatoria limnetica, was cloned by use of amino acid sequences of tryptic peptides as well as sequences conserved in the Rhodobacter capsulatus SQR and in an open reading frame found in the genome of Aquifex aeolicus. SQR activity was also detected in the unicellular cyanobacterium Aphanothece halophytica following sulfide induction, with a V max of 180 μmol of plastoquinone-1 (PQ-1) reduced/mg of chlorophyll/h and apparentKm values of 20 and 40 μM for sulfide and quinone, respectively. Based on the conserved sequences, the gene encoding A. halophytica SQR was also cloned. The SQR polypeptides deduced from the two cyanobacterial genes consist of 436 amino acids for O. limnetica SQR and 437 amino acids forA. halophytica SQR and show 58% identity and 74% similarity. The calculated molecular mass is about 48 kDa for both proteins; the theoretical isoelectric points are 7.7 and 5.6 and the net charges at a neutral pH are 0 and −14 for O. limneticaSQR and A. halophytica SQR, respectively. A search of databases showed SQR homologs in the genomes of the cyanobacteriumAnabaena PCC7120 as well as the chemolithotrophic bacteriaShewanella putrefaciens and Thiobacillus ferrooxidans. All SQR enzymes contain characteristic flavin adenine dinucleotide binding fingerprints. The cyanobacterial proteins were expressed in Escherichia coli under the control of the T7 promoter. Membranes isolated from E. coli cells expressing A. halophytica SQR performed sulfide-dependent PQ-1 reduction that was sensitive to the quinone analog inhibitor 2n-nonyl-4-hydroxyquinoline-N-oxide. The wide distribution of SQR genes emphasizes the important role of SQR in the sulfur cycle in nature.

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Oxidation of metal sulfides by Thiobacillus ferrooxidans grown on different substrates

Canadian Journal of Microbiology ◽

10.1139/m74-023 ◽

1974 ◽

Vol 20 (2) ◽

pp. 141-147 ◽

Cited By ~ 42

Author(s):

Marvin Silver ◽

Arpad E. Torma

Keyword(s):

Lead Sulfide ◽

Ferrous Sulfate ◽

Nickel Sulfide ◽

Thiobacillus Ferrooxidans ◽

Cell Types ◽

Metal Sulfides ◽

Sulfide Ore ◽

Sulfate Lead ◽

Chalcopyrite Ore ◽

Sulfide Concentrate

Thiobacillus ferrooxidans, grown on either ferrous sulfate, lead sulfide concentrate, or chalcopyrite concentrate demonstrated oxygen uptake and CO2 fixation in the presence of ferrous sulfate, chalcopyrite ore, pyrite ore, and red antimony trisulfide. Lead suifide-grown cells could oxidize lead sulfide ore and galena, using the energy obtained for CO2 fixation. All three cell types could oxidize nickel sulfide, but could not fix CO2 in the presence of this substrate. The solubilization of metals from the substrates and the crystallographic changes in the insoluble residues are reported.

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Thiobacillus acidophilus: a study of its presence in Thiobacillus ferrooxidans cultures

Canadian Journal of Microbiology ◽

10.1139/m80-178 ◽

1980 ◽

Vol 26 (9) ◽

pp. 1057-1065 ◽

Cited By ~ 15

Author(s):

G. J. M. W. Arkesteyn ◽

J. A. M. de Bont

Keyword(s):

Amino Acids ◽

Organic Acids ◽

Organic Compounds ◽

Ferrous Iron ◽

Thiobacillus Ferrooxidans ◽

Mixed Cultures ◽

Limited Extent ◽

Order Of Magnitude ◽

Thiobacillus Acidophilus

A study had been undertaken to account for the presence of Thiobacillus acidophilus in iron-grown cultures of Thiobacillus ferrooxidans. Attempts to adapt T. acidophilus to ferrous iron were not successful but the facultative autotroph grew to a limited extent in the spent medium of T. ferrooxidans and was able to grow oligotrophically. Possible oligotrophic substrates were methanol, ethanol, and sulphide. Thiobacillus ferrooxidans may benefit from the presence of T. acidophilus because in mixed cultures some inhibiting organic compounds such as alcohols, organic acids, and amino acids were utilized by T. acidophilus. The number of T. acidophilus cells in heterogeneous cultures with T. ferrooxidans was of the same order of magnitude as the number of T. ferrooxidans cells as revealed by fluorescent-labelled antibodies.

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Homochirality as the Signature of Extra-Terrestrial Life

International Astronomical Union Colloquium ◽

10.1017/s0252921100015037 ◽

1997 ◽

Vol 161 ◽

pp. 505-510

Author(s):

Alexandra J. MacDermott ◽

Laurence D. Barron ◽

Andrè Brack ◽

Thomas Buhse ◽

John R. Cronin ◽

...

Keyword(s):

Amino Acids ◽

Protein Synthesis ◽

Optical Rotation ◽

Physical Origin ◽

Natural Choice ◽

Rosetta Mission ◽

Terrestrial Life ◽

Subsurface Layers ◽

Solar System Bodies ◽

Origin Of Homochirality

AbstractThe most characteristic hallmark of life is its homochirality: all biomolecules are usually of one hand, e.g. on Earth life uses only L-amino acids for protein synthesis and not their D mirror images. We therefore suggest that a search for extra-terrestrial life can be approached as a Search for Extra- Terrestrial Homochirality (SETH). The natural choice for a SETH instrument is optical rotation, and we describe a novel miniaturized space polarimeter, called the SETH Cigar, which could be used to detect optical rotation as the homochiral signature of life on other planets. Moving parts are avoided by replacing the normal rotating polarizer by multiple fixed polarizers at different angles as in the eye of the bee. We believe that homochirality may be found in the subsurface layers on Mars as a relic of extinct life, and on other solar system bodies as a sign of advanced pre-biotic chemistry. We discuss the chiral GC-MS planned for the Roland lander of the Rosetta mission to a comet and conclude with theories of the physical origin of homochirality.

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Hydrogen Cyanide Polymers from the Impact of Comet P/Shoemaker-Levy 9 on Jupiter

International Astronomical Union Colloquium ◽

10.1017/s025292110001469x ◽

1997 ◽

Vol 161 ◽

pp. 179-187

Author(s):

Clifford N. Matthews ◽

Rose A. Pesce-Rodriguez ◽

Shirley A. Liebman

Keyword(s):

Amino Acids ◽

Solar System ◽

Hydrogen Cyanide ◽

Nitrogen Heterocycles ◽

Laboratory Studies ◽

Heterogeneous Solids ◽

The Many ◽

Comet Halley ◽

The Impact ◽

By Products

AbstractHydrogen cyanide polymers – heterogeneous solids ranging in color from yellow to orange to brown to black – may be among the organic macromolecules most readily formed within the Solar System. The non-volatile black crust of comet Halley, for example, as well as the extensive orangebrown streaks in the atmosphere of Jupiter, might consist largely of such polymers synthesized from HCN formed by photolysis of methane and ammonia, the color observed depending on the concentration of HCN involved. Laboratory studies of these ubiquitous compounds point to the presence of polyamidine structures synthesized directly from hydrogen cyanide. These would be converted by water to polypeptides which can be further hydrolyzed to α-amino acids. Black polymers and multimers with conjugated ladder structures derived from HCN could also be formed and might well be the source of the many nitrogen heterocycles, adenine included, observed after pyrolysis. The dark brown color arising from the impacts of comet P/Shoemaker-Levy 9 on Jupiter might therefore be mainly caused by the presence of HCN polymers, whether originally present, deposited by the impactor or synthesized directly from HCN. Spectroscopic detection of these predicted macromolecules and their hydrolytic and pyrolytic by-products would strengthen significantly the hypothesis that cyanide polymerization is a preferred pathway for prebiotic and extraterrestrial chemistry.

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Methionine-Specific Staining of Collagen

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010005408x ◽

1982 ◽

Vol 40 ◽

pp. 294-295

Author(s):

E.M. Kuhn ◽

K.D. Marenus ◽

M. Beer

Keyword(s):

Amino Acids ◽

Collagen Fibers ◽

Type Iii Collagen ◽

Type I ◽

Electron Microscopic ◽

Good Correspondence ◽

Specific Staining ◽

Type Iii ◽

Different Types ◽

Sulfur Containing

Fibers composed of different types of collagen cannot be differentiated by conventional electron microscopic stains. We are developing staining procedures aimed at identifying collagen fibers of different types.Pt(Gly-L-Met)Cl binds specifically to sulfur-containing amino acids. Different collagens have methionine (met) residues at somewhat different positions. A good correspondence has been reported between known met positions and Pt(GLM) bands in rat Type I SLS (collagen aggregates in which molecules lie adjacent to each other in exact register). We have confirmed this relationship in Type III collagen SLS (Fig. 1).

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Scanning Electron Microscope Study of Bacteria on Mineral Surfaces

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100090634 ◽

1976 ◽

Vol 34 ◽

pp. 130-131

Author(s):

V.K. Berry

Keyword(s):

Oxidation Reaction ◽

Electron Microscope Study ◽

Elemental Sulfur ◽

Thiobacillus Ferrooxidans ◽

Physical Contact ◽

Metal Sulfides ◽

Low Grade ◽

Mineral Surfaces ◽

Mineral Surface ◽

Scanning Electron Microscope Study

There are two strains of bacteria viz. Thiobacillus thiooxidansand Thiobacillus ferrooxidanswidely mentioned to play an important role in the leaching process of low-grade ores. Another strain used in this study is a thermophile and is designated Caldariella .These microorganisms are acidophilic chemosynthetic aerobic autotrophs and are capable of oxidizing many metal sulfides and elemental sulfur to sulfates and Fe2+ to Fe3+. The necessity of physical contact or attachment by bacteria to mineral surfaces during oxidation reaction has not been fairly established so far. Temple and Koehler reported that during oxidation of marcasite T. thiooxidanswere found concentrated on mineral surface. Schaeffer, et al. demonstrated that physical contact or attachment is essential for oxidation of sulfur.

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Prevalence of the pit and antipit in the genus Glycine

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100129218 ◽

1987 ◽

Vol 45 ◽

pp. 986-987

Author(s):

R. W. Yaklich ◽

E. L. Vigil ◽

W. P. Wergin

Keyword(s):

Amino Acids ◽

Endoplasmic Reticulum ◽

Glycine Max ◽

Seed Coat ◽

Cell Types ◽

Abaxial Surface ◽

Legume Seed ◽

Initial Report ◽

Cone Cells ◽

Glycine Max L

The legume seed coat is the site of sucrose unloading and the metabolism of imported ureides and synthesis of amino acids for the developing embryo. The cell types directly responsible for these functions in the seed coat are not known. We recently described a convex layer of tissue on the inside surface of the soybean (Glycine max L. Merr.) seed coat that was termed “antipit” because it was in direct opposition to the concave pit on the abaxial surface of the cotyledon. Cone cells of the antipit contained numerous hypertrophied Golgi apparatus and laminated rough endoplasmic reticulum common to actively secreting cells. The initial report by Dzikowski (1936) described the morphology of the pit and antipit in G. max and found these structures in only 68 of the 169 seed accessions examined.

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