rate of elemental sulfur oxidation in some soils of egypt as affected by the salinity level, moisture, texture, temperature and inoculation. | 1. the level of soil moisture most favourable to the oxidation of elemental sulfur was found to be around the field moisture capacity; the oxidation rate decreased at lower and higher moisture levels. 2. the rate of oxidation increased with the clay content of the soils from sandy loam to clay loam. 3. although s-oxidation could be found already at 10 degrees c, it increased markedly up to a maximum at 35 degrees c and then decreased again at higher temperatures. 4. increasing the salt content o ... | 1976 | 11771 |
purificantion and characterization of inorganic pyrophosphatase from thiobacillus thiooxidans. | an inorganic pyrophosphatase ec 3.6.1.1 was isolated from thiobacillus thiooxidans and purified 975-fold to a state of apparent homogeneity. the enzyme catalyzed the hydrolysis of inorganic pyrophosphate and no activity was found with a variety of other phosphate esters. the cation mg2+ was required for maximum activity; co2+ and mn2+ supported 25 per cent and 10.6 per cent of the activity with mg2+, respectively. the ph optimum was 8.8. the molecular weight was estimated to be 88,000 by gel fil ... | 1977 | 14950 |
acidostability of speroplasts prepared from thiobacillus thiooxidans. | thiobacillus thiooxidans was acidostable even in the absence of its respiratory substrate, elementary sulfur. this suggests that the acidostability of the bacterium was enery-independent. the organism was subjected to osmotic shock with 0.75 m sucrose at 0 degrees c and then treated with snail intestinal juice in the presence of 0.3 m sucrose. the decrease in the optical density of the sample thus prepared on dilution with deionized water and electron microscopic observation of the sample showed ... | 1977 | 15528 |
purification and some properties of cytochrome c-552 from a sulfur-oxidizing bacterium, thiobacillus thiooxidans. | a soluble cytochrome c-552 from thiobacillus thiooxidans was highly purified and its physico-chemical properteis were studied. the absorption maxima were at 552,523,418 nm in the reduced from and at 412 nm in the oxidized form. the pyridine hemochrome spectrum was the same as that of other cytochromes c. the molecular weight, estimated by the gel filtration method, was found to be 12,600. the isoelectric point was determined to be 9.2-9.3 by the electrofocusing technique. the standard oxidation- ... | 1975 | 172491 |
physical and chemical studies of thiobacillus ferroxidans lipopolysaccharides. | the lipopolysaccharides (lps) of the obligate acidophile thiobacillus ferroxidans grown on iron, sulfur, and glucose as energy sources were examined for various physical and chemical properties. both qualitative and quantitative variation were found among the three preparations. the lps extracted from iron-grown cells (fe-lps) contained less than 3% protein compared to 18 to 25% in lps extracted from either sulfur-grown cells (s-lps) or glucose-grown cells (g-lps). s-lps showed two distinct sedi ... | 1975 | 238956 |
the interpretation of the mass spectrum of an ornithine-containing lipid from thiobacillus thiooxidans. | the electron impact mass spectrum of a previously identified ornithine-containing lipid from thiobacillus thiooxidans has been interpreted using exact mass measurements, low and high energy ionization, and defocused metastable studies. the spectrum, which did not contain a molecular ion for the intact lipid, was consistent with cyclization of the ornithine zwitterionic moiety with elimination of water to give 3[3'-(11,12-methylene-2-hydroxyoctadecanoxy)hexadecanylamine]-2-piperidone. production ... | 1978 | 342005 |
[physiological properties of the thionic bacteria isolated from paleogene deposits]. | | 1979 | 375037 |
[morphogenetic features of sulfobacillus thermosulfidooxidans]. | the morphogenesis of sulfobacillus thermosulfidooxidans bkm b-1269 was studied by electron microscopy at the vegetative stage of growth on a medium with pyrite as the source of energy. young growing cultures of this organism were found to be very polymorphous: along with rod-like cells of various dimensions (0.6--0.8x1.0--3.0 mcm) which were predominant, coccoid, pyriform, clavate and dumbbell-like cells were also encountered. certain cells have a tendency for branching. the cells can divide by ... | 1979 | 388160 |
rotational mobility of membrane-bound cytochrome o of escherichia coli and cytochrome a1 of thiobacillus ferro-oxidans [proceedings]. | | 1979 | 389702 |
[effect of clays on the behavior of acidophilic thiobacillus strains in suspensions]. | | 1979 | 397686 |
[microbial desulfuration of coal. i. isolation and identification of iron- and sulfur-oxidizing bacteria]. | | 1979 | 400534 |
[geochemical activity of thionic bacteria]. | | 1977 | 409914 |
pyruvate inhibition of the carbon dioxide fixation of the strict chemolithotroph thiobacillus thiooxidans. | a flow-through dialysis system used to decrease the concentrations of toxic organic materials excreted by thiobacillus thiooxidans permitted an improved efficiency of carbon dioxide fixation when compared with cells taken from the usual shaken culture. the additions of various concentrations of pyruvic acid and succinic acid inhibited growth significantly. pyruvate at a concentration of 5 x 10(-3) m completely inhibited the respiration of resting cells oxidizing sulfur. the toxicity of pyruvic a ... | 1975 | 766931 |
[function of surface membrane structures in thiobacillus thiooxidans]. | the function of the surface membrane structures was studied with cytochemical techniques on ultrathin sections of thiobacillus thiooxidans. the transport of elementary sulphur inside the cell involves the surface membrane structures, while oxidation of the sulphur to sulphuric acid takes place on the outer surface of the cytoplasmic membrane. the surface membrane structures are supposed also to participate in the primary dissolution of elementary sulphur at the site of contact of the cells with ... | 1975 | 775257 |
[degradation of sulfur compounds by pure cultures of thiobacillus]. | | 1976 | 785827 |
bacterial leaching of waste uranium materials. | the effect of ferrobacteria and thiobacteria on the leaching of waste uranium materials from which 70-80% of uranium was previously leached by classical chemical hydrometallurgical procedure has been investigated. the bacteria used are found in the ore and the mine water of zletovska river locality, yugoslavia. parameters of biological leaching were examined in the laboratory. leaching conditions were changed with the aim of increasing the amount of uranium leached. the effect of pyrite added to ... | 1976 | 788361 |
identification of thiobacilli by replica plating on thallous sulfide paper. | colonies of thiobacillus thioparus and t. thiooxidans grown on thiosulfate medium can be identified by replica plating on thallous sulfide paper. | 1976 | 791118 |
ferric iron reduction by sulfur- and iron-oxidizing bacteria. | acidophilic bacteria of the genera thiobacillus and sulfolobus are able to reduce ferric iron when growing on elemental sulfur as an energy source. it has been previously thought that ferric iron serves as a nonbiological oxidant in the formation of acid mine drainage and in the leaching of ores, but these results suggest that bacterial catalysis may play a significant role in the reactivity of ferric iron. | 1976 | 825043 |
roles of the tn21 mert, merp, and merc gene products in mercury resistance and mercury binding. | the mercury resistance (mer) operon of the gram-negative transposon tn21 encodes not only a mercuric reductase and regulatory genes but also two inner membrane proteins (mert and merc) and a periplasmic protein (merp). although the mert, merp, and merc genes have been implicated in hg(ii) transport, the individual roles of these genes have not been established. we created in vitro precise deletion and frameshift mutations that eliminated each of the genes singly and in combination. our results s ... | 1992 | 1328156 |
the merr regulatory gene in thiobacillus ferrooxidans is spaced apart from the mer structural genes. | two distinct merr genes, which regulate expression of the mercuric ion resistance gene (mer), of thiobacillus ferrooxidans strain e-15 have been cloned, sequenced and termed merr1 and merr2. as a result of gene walking around two merr genes, it was found that these two genes were quite close in distance. the nucleotide sequence of the region (5,001 base pairs; psti-ecori fragment) containing the merr genes was determined. between the two merr genes, there were five potential open reading frames ... | 1991 | 1779760 |
characterization of arsenopyrite oxidizing thiobacillus. tolerance to arsenite, arsenate, ferrous and ferric iron. | two strains of thiobacillus, t. ferrooxidans and t. thiooxidans, have been isolated from a bacterial inoculum cultivated during a one-year period in a 1001 continuous laboratory pilot for treatment of an arsenopyrite/pyrite concentrate. the optimum ph for the growth of both strains has been found to be between 1.7 and 2.5. because of the high metal toxicity in bioleach pulps, the tolerance of t. ferrooxidans and t. thiooxidans with respect to iron and arsenic has been studied. the growth of both ... | 1990 | 2191624 |
complementation of escherichia coli sigma 54 (ntra)-dependent formate hydrogenlyase activity by a cloned thiobacillus ferrooxidans ntra gene. | the ntra gene of thiobacillus ferrooxidans was cloned by complementation of an escherichia coli ntra mutant that was unable to produce gas via the sigma 54 (ntra)-dependent formate hydrogenlyase pathway. analysis of the dna sequence showed that the t. ferrooxidans ntra gene coded for a protein of 475 amino acids (calculated mr, 52,972). the t. ferrooxidans ntra protein had 49, 44, 33, and 18% amino acid similarity with the ntra proteins of klebsiella pneumoniae, azotobacter vinelandii, rhizobium ... | 1990 | 2198257 |
[cloning and expression of a promoter function fragment from thiobacillus thiooxidans in escherichia coli]. | this paper reports a recombinant plasmid psdr12 which is constructed through the substitution of the ecori-hindiii fragment of pbr322 by a specific fragment of chromosomal dna of t. thiooxidans. after it was transformed into c600, the transformants revealed higher levels of tc resistance. this result shows that a promoter function fragment from autotrophic bacteria is able to express in escherichia coil. | 1990 | 2242277 |
[dissolution of alloy components from ni/cr base alloys by bacterial leaching]. | the method of bacterial leaching of non precious dental alloys represents a useful completion of the method arsenal of biological investigations. in contrast to other well known methods it allows to point out small differences in corrosion resistance between alloys of the same type in a biologic system. | 1990 | 2269176 |
nucleotide sequence of the thiobacillus ferrooxidans chromosomal gene encoding mercuric reductase. | the nucleotide sequence of the thiobacillus ferrooxidans chromosomal mercuric-reductase-encoding gene (mera) has been determined. the mera gene contains 1635 bp, and shares 78.2% and 76.6% sequence homology with the transposon, tn501, and plasmid r100 mera genes, respectively. from the sequence, a 545-amino acid (aa) polypeptide was deduced, and comparison with those of tn501 and r100 revealed 80.6% and 80.0% homology, respectively, at the aa sequence level. divergence among the three mera aa se ... | 1989 | 2691338 |
reduction of mo6+ with elemental sulfur by thiobacillus ferrooxidans. | in the presence of phosphate ions, molybdic ions (mo6+) were reduced enzymatically with elemental sulfur by washed intact cells of thiobacillus ferrooxidans to give molybdenum blue. the whole-cell activity that reduced mo6+ was totally due to cellular sulfur:ferric ion oxidoreductase (sforase) (t. sugio, w. mizunashi, k. inagaki, and t. tano, j. bacteriol. 169:4916-4922, 1987). the activity of m06+ reduction with elemental sulfur was competitively inhibited by fe3+, cu2+, and co2+. the michaelis ... | 1988 | 3056928 |
preservation of thiobacillus ferrooxidans and thiobacillus thiooxidans with activity check. | cultures of thiobacillus ferrooxidans and thiobacillus thiooxidans, used in biohydrometallurgical processes of economic importance, are very difficult to preserve by conventional methods. hence, to preserve the cultures with their activity intact, various techniques were tried, after determining their respective activity in terms of iron oxidation rate (ior) and sulfur oxidation rate (sor). among the methods tested, along with the recommended method of serial transfer in a liquid medium, were me ... | 1986 | 3524447 |
[carbon dioxide fixation on 3-carbon acceptors in the obligate chemoautotroph thiobacillus thiooxidans]. | | 1974 | 4156074 |
[inhibition of ribulosediphosphate carboxylase by adenosine triphosphate in autotrophic organisms]. | | 1973 | 4198598 |
[submicroscopic structure of the bacterial cell wall (review of the literature)]. | | 1973 | 4206610 |
[ribosephosphate isomerase, phosphoribulokinase and ribulosediphosphate carboxylase in extracts of thiobacillus thiooxidans 58 r cells]. | | 1973 | 4360786 |
[geomicrobiological studies. xii. behavior of microorganisms on uranium containing rocks]. | | 1974 | 4365496 |
degradation of oil shale by sulfur-oxidizing bacteria. | approximately 40% of oil shale can be solubilized by the action of sulfur-oxidizing bacteria. thiobacillus thiooxidans and thiobacillus concretivorous are equally effective in solubilization. continuous leaching experiments show that this process can be completed within 14 days. the growth of thiobacillus and the production of acid were measured under several conditions. almost all of the camg(co(3))(2) was removed by this process, leaving a complex of silica and kerogen that could be burned as ... | 1974 | 4370628 |
phosphoenolpyruvate carboxylase of thiobacillus thiooxidans. kinetic and metabolic control properties. | | 1972 | 4552310 |
the structure of an ornithine-containing lipid from thiobacillus thiooxidans. | | 1972 | 4552922 |
ecology of sulfur-oxidizing bacteria in hot acid soils. | hot acid soils in yellowstone national park are rich in elemental sulfur and harbor extensive populations of sulfur-oxidizing bacteria. thiobacillus thiooxidans is found at temperatures below 55 c, and at temperatures from 55 to 85 c sulfolobus acidocaldarius is present. the distribution of these bacteria as a function of temperature was measured by a most-probable-number dilution method, and their activity in situ was assessed by use of a new technique permitting measurement of (14)co(2) fixati ... | 1972 | 4559726 |
characterization of thiobacillus species by gas-liquid chromatography of cellular fatty acids. | | 1973 | 4571173 |
effect of supplementary aeration on the growth of thiobacillus thiooxidans in shaken cultures. | | 1973 | 4572380 |
heterotrophic nature of the cell-free protein-synthesizing system from the strict chemolithotroph, thiobacillus thiooxidans. | a cell-free protein-synthesizing system prepared from the strict chemolithotroph, thiobacillus thiooxidans, was similar to that of heterotrophs. the poly-u directed system had a temperature optimum of 37 c, but in the presence of spermidine (3 mm) the optimum shifted to 45 c. although growth of the chemolithotroph occurs only in acid conditions, the ph optimum for the cell-free system was ph 7.2. the endogenous-directed activity in the presence or absence of spermidine was maximal at ph 7.8. spe ... | 1974 | 4590488 |
[oxidation of elementary sulfur by thiobacillus thiooxidans]. | | 1973 | 4597880 |
[effect of atmospheric oxygen partial pressure and of the acidity of the medium on the viability of thionic bacteria]. | | 1973 | 4598493 |
[oxidation of sulfide minerals by thiobacillus thiooxidans]. | | 1974 | 4601474 |
a sulfate-dependent acid phosphatase of thiobacillus thiooxidans. its partial purification and some properties. | | 1974 | 4609973 |
scanning electron microscopy of thiobacilli grown on colloïdal sulfur. | | 1974 | 4611376 |
relationship between growth and metabolic activity in the strict chemolithotroph, thiobacillus thiooxidans. | | 1974 | 4613448 |
[microbiologic studies of copper pyrite deposits in south ural]. | | 1974 | 4615253 |
[participation of carbonic anhydrase in the assimilation of carbon dioxide during chemical synthesis by thiobacillus thiooxidans 58r]. | | 1972 | 4623370 |
fatty acids of thiobacillus thiooxidans. | fatty acid spectra were made on thiobacillus thiooxidans cultures both in the presence and absence of organic compounds. small additions of glucose or acetate had no significant effect either on growth or fatty acid content. the addition of biotin had no stimulatory effect but did result in slight quantitative changes in the fatty acid spectrum. the predominant fatty acid was a c(19) cyclopropane acid. | 1971 | 4945206 |
[the biological properties of bacteria oxidizing rhodanic salts with reference to their use for the purification of industrial wastes]. | | 1971 | 4949234 |
expression of a thiobacillus ferrooxidans origin of replication in escherichia coli. | a cryptic plasmid from an autotrophically grown arsenic-resistant strain of thiobacillus ferrooxidans was isolated and cloned into pbr325. the origin of replication of pbr325 was deleted, and the recombinant plasmid was shown to replicate in escherichia coli, using an origin of replication located on the thiobacillus plasmid. | 1984 | 6373729 |
the acidophilic thiobacilli and other acidophilic bacteria that share their habitat. | | 1984 | 6388492 |
[role of microorganisms in the destruction of spodumene]. | a broad spectrum of microorganisms has been shown to be involved in the destruction of spodumene, a typical mineral of lithium pegmatites. the following microorganisms are most active: the microscopic fungi penicillium notatum and aspergillus niger, the thiobacilli thiobacillus thiooxidans, and the so-called "silicate" slime forming bacterium bacillus micilaginosus n. sp. siliceus. spodumene destruction is accompanied with lithium, aluminium and silicon being transferred into solution. the activ ... | 1980 | 6995818 |
localization of quantitation of the ornithine lipid of thiobacillus thiooxidans. | the ornithine lipid of thiobacillus thiooxidans was found to be 1.9% of the total polar lipids. approximately 80% of this lipid was found to be localized in the outer membrane. | 1982 | 7035440 |
cultural and phylogenetic analysis of mixed microbial populations found in natural and commercial bioleaching environments. | a range of autotrophic and heterotrophic enrichment cultures were established to determine the cultural bacterial diversity present in samples obtained from the acidic runoff of a chalcocite overburden heap and from laboratory-scale (1- to 4-liter) batch and continuous bioreactors which were being used for the commercial assessment of the bioleachability of zinc sulfide ore concentrates. strains identified as thiobacillus ferrooxidans, thiobacillus thiooxidans, "leptospirillum ferrooxidans," and ... | 1994 | 7517131 |
thiobacillus ferrooxidans tyrosyl-trna synthetase functions in vivo in escherichia coli. | the tyrosyl-trna synthetase gene (tyrz) from thiobacillus ferrooxidans, an acidophilic, autotrophic, gram-negative bacterium that participates in bioleaching of minerals, was cloned and sequenced. the encoded polypeptide (tyrrz) is 407 amino acids in length (molecular mass; 38 kda). the predicted protein sequence has an extensive overall identity (44%) to the sequence of the protein encoded by the bacillus subtilus tyrz gene, one of the two genes encoding tyrosyl-trna synthetases in this microor ... | 1994 | 7517395 |
purification and properties of high-potential iron-sulfur proteins. | | 1994 | 7830619 |
respiratory enzymes of thiobacillus ferrooxidans. kinetic properties of an acid-stable iron:rusticyanin oxidoreductase. | rusticyanin is an acid-stable, soluble blue copper protein found in abundance in the periplasmic space of thiobacillus ferrooxidans, an acidophilic bacterium capable of growing autotrophically on soluble ferrous sulfate. an acid-stable iron:rusticyanin oxidoreductase activity was partially purified from cell-free extracts of t. ferrooxidans. the enzyme-catalyzed, iron-dependent reduction of the rusticyanin exhibited three kinetic properties characteristic of aerobic iron oxidation by whole cells ... | 1994 | 8049223 |
effect of ph on sulfite oxidation by thiobacillus thiooxidans cells with sulfurous acid or sulfur dioxide as a possible substrate. | the oxidation of sulfite by thiobacillus thiooxidans was studied at various ph values with changing concentrations of potassium sulfite. the optimal ph for sulfite oxidation by cells was a function of sulfite concentrations, rising with increasing substrate concentrations, while that by the cell extracts was unaffected. the sulfite oxidation by cells was inhibited at high sulfite concentrations, particularly at low ph values. the results from kinetic studies show that the fully protonated form o ... | 1994 | 8300544 |
mercuric ion uptake by escherichia coli cells producing thiobacillus ferrooxidans merc. | the merc gene of thiobacillus ferrooxidans was overexpressed in escherichia coli under the control of the tac promoter. merc protein synthesized in e. coli has a n-terminal amino acid sequence of s-a-i-x-r-i-i-d-k-i-g-i-v-g-, which agrees with the amino acid sequence deduced from its nucleotide sequence except that an initiating methionine residue was removed. the merc protein was localized in the particulate (membrane) cell fraction, and not in the soluble cytoplasmic fraction. e. coli cells ca ... | 1996 | 8987545 |
sol-gel applications in environmental biotechnology. | sol gel process was applied for three different applications in environmental biotechnology: (1) thin, fluorescein diacetate-doped sol-gel film made possible epifluorescent microscopic examination of adsorbed escherichia coli cn13 cells without additional staining: (2) thiobacillus thiooxidans cell-free extract entrapped into sol-gel matrix displayed oxidative activity on h2s in liquid medium; and (3) two media (e. coli (ec) and sulfate-reducing bacteria (srb)) were doped into sol-gel and used t ... | 1996 | 8988652 |
genomic organization of the acidophilic chemolithoautotrophic bacterium thiobacillus ferrooxidans atcc 21834. | the genomic organization of the acidophilic chemolithoautotrophic bacterium thiobacillus ferrooxidans atcc 21834 has been studied by pulsed-field gel electrophoresis (pfge). analysis of its intact dna, as well as the restriction patterns obtained with several endonucleases, allowed the characterization of one circular chromosome of 2.9 mb and one plasmid of 8.6 kb. the first complete and highly resolved physical map (86 restriction sites) of the chromosome of an acidophilic obligate chemolithoau ... | 1997 | 9068640 |
the potential of mining slag as a substrate for microbial growth and the microbiological analysis of slag and slag seepage. | the potential of a cu/ni mining slag to act as a substrate for the growth of the bacteria thiobacillus ferrooxidans, thiobacillus thiooxidants, and thiobacillus thioparus was examined. as well, slag and slag seepage samples were screened for the presence of the thiobacillus species. for the 28 samples employed in the environmental recovery studies, t. ferrooxidans was recovered in 25 samples, t. thiooxidans in 19 samples, and t. thioparus in 27 samples. for r. ferrooxidans, the development of a ... | 1997 | 9195014 |
a geographically widespread plasmid from thiobacillus ferrooxidans has genes for ferredoxin-, fnr-, prismane- and nadh-oxidoreductase-like proteins which are also located on the chromosome. | during a search for genes encoding electron transport proteins from a thiobacillus ferroxidans atcc 33020 gene bank, a 19.8 kb plasmid, ptf5, which conferred increased sensitivity to the antimicrobial agent metronidazole upon an escherichia coli mutant, was isolated and cloned in e. coli. the plasmid had an identical restriction enzyme map to a plasmid which has been found in t. ferrooxidans strains isolated from many different parts of the world. the plasmid was present at between two and four ... | 1997 | 9353917 |
a mercuric ion uptake role for the integral inner membrane protein, merc, involved in bacterial mercuric ion resistance. | bacterial detoxification of mercuric ion depends on the presence of one or more integral membrane proteins (mert and/or merc) whose postulated function is in transport of hg2+ from a periplasmic hg2+-binding protein (merp) to cytoplasmic mercuric reductase. in this study, merc from the tn21-encoded mer operon was overexpressed and studied in vesicles and in purified form to clarify the role played by this protein in mercuric ion resistance. merc-containing vesicles were found to take up mercuric ... | 1997 | 9368013 |
a tn7-like transposon is present in the glmus region of the obligately chemoautolithotrophic bacterium thiobacillus ferrooxidans. | the region downstream of the thiobacillus ferrooxidans atcc 33020 atp operon was examined, and the genes encoding n-acetylglucosamine-1-uridyltransferase (glmu) and glucosamine synthetase (glms) were found. this atpefhagdc-glmus gene order is identical to that of escherichia coli. the t. ferrooxidans glms gene was shown to complement e. coli glms mutants for growth on minimal medium lacking glucosamine. a tn7-like transposon, tn5468, was found inserted into the region immediately downstream of t ... | 1998 | 9603897 |
surface chemical studies of thiobacillus ferrooxidans with reference to copper tolerance. | a strain of thiobacillus ferrooxidans was adapted to grow at higher concentrations of copper by single step culturing in the presence of 20 g/l (0.314 mol/l) cupric ions added to 9k medium. exposure to copper results in change in the surface chemistry of the microorganism. the isoelectric point of the adapted strain (pi = 4.7) was observed to be at a higher ph than that of the wild unadapted strain (pi = 2.0). compared to the wild strain, the copper adapted strain was found to be more hydrophobi ... | 1998 | 9801765 |
metal resistance and plasmid dna in thiobacillus ferrooxidans. | the minimal inhibitory concentrations of copper and nickel were determined for each of fifteen isolates of t. ferrooxidans native to a cu/ni tailings environment. ten isolates were inhibited by 160 mm cu2+ or less, and ten were inhibited by 160 mm ni2+ or less. the isolates were screened for plasmid dna using an alkaline lysis method and ccc plasmid forms were confirmed using the hintermann technique. two isolates were found to be devoid of plasmid dna, and only one isolate contained more than t ... | 1998 | 9801769 |
roles of the four cysteine residues in the function of the integral inner membrane hg2+-binding protein, merc. | the roles of the four cysteine residues of the integral inner membrane hg2+-binding protein, merc, have been examined using site-directed mutagenesis. residues cys-22 and cys-25 have previously been predicted to lie within the membrane. substitution of each of these residues in turn with alanine resulted in complete abolition of specific hg2+ uptake by vesicles. in contrast, substitution by alanine of the other two cysteine residues, cys-127 and cys-132, predicted to lie with within a c-terminal ... | 1999 | 10049704 |
interaction-induced redox switch in the electron transfer complex rusticyanin-cytochrome c(4). | the blue copper protein rusticyanin isolated from the acidophilic proteobacterium thiobacillus ferrooxidans displays a ph-dependent redox midpoint potential with a pk value of 7 on the oxidized form of the protein. the nature of the alterations of optical and epr spectra observed above the pk value indicated that the redox-linked deprotonation occurs on the epsilon-nitrogen of the histidine ligands to the copper ion. complex formation between rusticyanin and its probable electron transfer partne ... | 1999 | 10521412 |
effect of various ions, ph, and osmotic pressure on oxidation of elemental sulfur by thiobacillus thiooxidans. | the oxidation of elemental sulfur by thiobacillus thiooxidans was studied at ph 2.3, 4.5, and 7.0 in the presence of different concentrations of various anions (sulfate, phosphate, chloride, nitrate, and fluoride) and cations (potassium, sodium, lithium, rubidium, and cesium). the results agree with the expected response of this acidophilic bacterium to charge neutralization of colloids by ions, ph-dependent membrane permeability of ions, and osmotic pressure. | 1999 | 10543839 |
reclassification of some species of thiobacillus to the newly designated genera acidithiobacillus gen. nov., halothiobacillus gen. nov. and thermithiobacillus gen. nov. | the species of the genus 'thiobacillus' fall into the alpha-, beta- and gamma-subclasses of the proteobacteria, the type species thiobacillus thioparus being located in the beta-subclass. 'thiobacillus' species exhibit almost as much diversity in dna composition and physiology as is found collectively in all other proteobacterial groups. on the basis of physiological characters and 16s rrna gene sequence comparisons, eight of the existing thiobacillus species are proposed for reassignment to thr ... | 2000 | 10758854 |
merf is a mercury transport protein: different structures but a common mechanism for mercuric ion transporters? | mercury resistance determinants are widespread in gram-negative bacteria, but vary in the number and identity of genes present. we have shown that the merf gene from plasmid pmer327/419 encodes a 8.7 kda mercury transport protein, by determining in vivo mercury volatilisation when merf is expressed in the presence of mercuric reductase. we have confirmed that merc of tn21 is also a mercuric ion transporter. we have been able to detect interaction of the periplasmic protein merp only with the mer ... | 2000 | 10781809 |
the chromosomal arsenic resistance genes of thiobacillus ferrooxidans have an unusual arrangement and confer increased arsenic and antimony resistance to escherichia coli. | the chromosomal arsenic resistance genes of the acidophilic, chemolithoautotrophic, biomining bacterium thiobacillus ferrooxidans were cloned and sequenced. homologues of four arsenic resistance genes, arsb, arsc, arsh, and a putative arsr gene, were identified. the t. ferrooxidans arsb (arsenite export) and arsc (arsenate reductase) gene products were functional when they were cloned in an escherichia coli ars deletion mutant and conferred increased resistance to arsenite, arsenate, and antimon ... | 2000 | 10788346 |
molecular cloning, sequencing, and expression of omp-40, the gene coding for the major outer membrane protein from the acidophilic bacterium thiobacillus ferrooxidans. | thiobacillus ferrooxidans is one of the chemolithoautotrophic bacteria important in industrial biomining operations. some of the surface components of this microorganism are probably involved in adaptation to their acidic environment and in bacterium-mineral interactions. we have isolated and characterized omp40, the gene coding for the major outer membrane protein from t. ferrooxidans. the deduced amino acid sequence of the omp40 protein has 382 amino acids and a calculated molecular weight of ... | 2000 | 10831405 |
effect of anions on selective solubilization of zinc and copper in bacterial leaching of sulfide ores. | bacterial leaching of sulfide ores using thiobacillus ferrooxidans, thiobacillus thiooxidans, or a combination of the two was studied at various concentrations of specific anions. selective zinc and copper solubilization was obtained by inhibiting iron oxidation without affecting sulfur/sulfide oxidation. phosphate reduced iron solubilization from a pyrite (fes(2))-sphalerite (zns) mixture without significantly affecting zinc solubilization. copper leaching from a chalcopyrite (cufes(2))-sphaler ... | 2000 | 10861398 |
development and application of small-subunit rrna probes for assessment of selected thiobacillus species and members of the genus acidiphilium. | culture-dependent studies have implicated sulfur-oxidizing bacteria as the causative agents of acid mine drainage and concrete corrosion in sewers. thiobacillus species are considered the major representatives of the acid-producing bacteria in these environments. small-subunit rrna genes from all of the thiobacillus and acidiphilium species catalogued by the ribosomal database project were identified and used to design oligonucleotide dna probes. two oligonucleotide probes were synthesized to co ... | 2000 | 10877807 |
microbiology of acidic, geothermal springs of montserrat: environmental rdna analysis. | dna was extracted from water and sediment samples taken from acidic, geothermal pools on the caribbean island of montserrat. 16s rrna genes were amplified by pcr, cloned, sequenced, and examined to indicate some of the organisms that might be significant components of the in situ microbiota. a clone bank representing the lowest temperature pool that was sampled (33 degrees c) was dominated by genes corresponding to two types of acidophiles: acidiphilium-like mesophilic heterotrophs and thermotol ... | 2000 | 11057917 |
the quality of merc, a module of the mer mosaic. | we examined a region of high variability in the mosaic mercury resistance (mer) operon of natural bacterial isolates from the primate intestinal microbiota. the region between the merp and mera genes of nine mer loci was sequenced and either the merc, the merf, or no gene was present. two novel merc genes were identified. overall nucleotide diversity, pi (per 100 sites), of the merc gene was greater (49.63) than adjacent merp (35.82) and mera (32.58) genes. however, the consequences of this vari ... | 2000 | 11116334 |
a new look at microbial leaching patterns on sulfide minerals. | leaching patterns on sulfide minerals were investigated by high-resolution scanning electron microscopy (sem). our goal was to evaluate the relative contributions of inorganic surface reactions and reactions localized by attached cells to surface morphology evolution. experiments utilized pyrite (fes(2)), marcasite (fes(2)) and arsenopyrite (feass), and two iron-oxidizing prokaryotes in order to determine the importance of cell type, crystal structure, and mineral dissolution rate in microbially ... | 2001 | 11137599 |
conserved amino acids near the carboxy terminus of bacterial tyrosyl-trna synthetase are involved in trna and tyr-amp binding. | bacterial tyrosyl-trna synthetases occur in two large subfamilies, tyrrs and tyrrz, that possess about 25% amino acid identity. their amino-terminal region, the active site domain, is more conserved (>36% identity). the carboxy-terminal segment of these enzymes includes the trna binding domain and contains only few conserved residues. replacement of three of these residues in acidithiobacillus ferrooxidans tyrrz revealed that s356 and k395 play roles in trna binding, while h306, a residue at the ... | 2001 | 11240138 |
purification and properties of thiosulfate dehydrogenase from acidithiobacillus thiooxidans jcm7814. | a key enzyme of the thiosulfate oxidation pathway in acidithiobacillus thiooxidans jcm7814 was investigated. as a result of assaying the enzymatic activities of thiosulfate dehydrogenase, rhodanese, and thiosulfate reductase at 5.5 of intracellular ph, the activity of thiosulfate dehydrogenase was measured as the key enzyme. the thiosulfate dehydrogenase of a. thiooxidans jcm7814 was purified using three chromatographies. the purified sample was electrophoretically homogeneous. the molecular mas ... | 2001 | 11272812 |
mechanism of growth inhibition by tungsten in acidithiobacillus ferrooxidans. | cell growth of three hundred iron-oxidizing bacteria isolated from natural environments was inhibited strongly by 0.05 mm, and completely by 0.2 mm of sodium tungstate (na2wo4), respectively. since no great difference in the level of tungsten inhibition was observed among the 300 strains tested, the mechanism of inhibition by na2wo4 was studied with acidithiobacillus ferrooxidans strain ap19-3. when resting cells of ap19-3 were incubated in 0.1 m beta-alanine-so4(2-) buffer (ph 3.0) with 0.1 mm ... | 2001 | 11330668 |
isolation of a new broad-host-range incq-like plasmid, ptc-f14, from the acidophilic bacterium acidithiobacillus caldus and analysis of the plasmid replicon. | a moderately thermophilic (45 to 50 degrees c), highly acidophilic (ph 1.5 to 2.5), chemolithotrophic acidithiobacillus caldus strain, f, was isolated from a biooxidation process used to treat nickel ore. trans-alternating field electrophoresis analysis of total dna from the a. caldus cells revealed two plasmids of approximately 14 and 45 kb. the 14-kb plasmid, designated ptc-f14, was cloned and shown by replacement of the cloning vector with a kanamycin resistance gene to be capable of autonomo ... | 2001 | 11344137 |
mechanism of oxidation of inorganic sulfur compounds by thiosulfate-grown thiobacillus thiooxidans. | thiobacillus thiooxidans was grown at ph 5 on thiosulfate as an energy source, and the mechanism of oxidation of inorganic sulfur compounds was studied by the effect of inhibitors, stoichiometries of oxygen consumption and sulfur, sulfite, or tetrathionate accumulation, and cytochrome reduction by substrates. both intact cells and cell-free extracts were used in the study. the results are consistent with the pathway with sulfur and sulfite as the key intermediates. thiosulfate was oxidized after ... | 2001 | 11358175 |
a refinement of the biofilm formation method for waste forms stability evaluation. | a refinement of the biofilm formation method for waste form stability evaluation was carried out in this study. refinement of the biofilm formation method became necessary because of the reduced contrast in degradation between control and experimental samples. the reduction in contrast was occasioned by the long duration of exposure (12 days) of the control samples to sterile medium of low ph in the first stage. results of evaluation carried out reveal that the duration of the first stage of the ... | 2001 | 11376887 |
the eps of acidithiobacillus ferrooxidans--a model for structure-function relationships of attached bacteria and their physiology. | to dissolve pyrite or sulphur, leaching bacteria like acidithiobacillus ferrooxidans attach to these substrata by extracellular polymeric substances (specifically, lipopolysaccharides). the primary attachment to pyrite at ph 2 is mediated by exopolymer-complexed iron(iii) ions in an electrostatic interaction with the negatively charged pyrite surface. cells grown on sulphur exhibit a different composition of the extracellular lipopolysaccharides, namely with increased hydrophobic properties, and ... | 2001 | 11381962 |
monitoring of bio-oxidation process of ferrous ion by using piezoelectric impedance analysis. | a new method of monitoring the bio-oxidation process of ferrous ion in the presence of thiobacillus ferroxidans was proposed by piezoelectric impedance analysis. the time courses of the responses of impedance parameters for a quartz crystal in a culture system were simultaneously obtained and discussed. it was found that the frequency shift response originates mainly from the adsorption of bacterial metabolites on the surface of gold electrode. experiments also examined the effect of culture tem ... | 2001 | 11391468 |
isafe1, an isl3 family insertion sequence from acidithiobacillus ferrooxidans atcc 19859. | a 1.3-kb insertion sequence, termed isafe1 (u66426), from acidithiobacillus ferrooxidans atcc 19859 is described. isafe1 exhibits the features of a typical bacterial insertion sequence. it has 26-bp, imperfectly matched, terminal inverted repeats and an open reading frame (orf) that potentially encodes a transposase (tpase) of 404 amino acids (aab07489) with significant similarity to members of the isl3 family of insertion sequences. a potential ribosome-binding site and potential -10 and -35 pr ... | 2001 | 11418574 |
a dual-specific glu-trna(gln) and asp-trna(asn) amidotransferase is involved in decoding glutamine and asparagine codons in acidithiobacillus ferrooxidans. | the gatc, gata and gatb genes encoding the three subunits of glutamyl-trna(gln) amidotransferase from acidithiobacillus ferrooxidans, an acidophilic bacterium used in bioleaching of minerals, have been cloned and expressed in escherichia coli. as in bacillus subtilis the three gat genes are organized in an operon-like structure in a. ferrooxidans. the heterologously overexpressed enzyme converts glu-trna(gln) to gln-trna(gln) and asp-trna(asn) to asn-trna(asn). biochemical analysis revealed that ... | 2001 | 11445070 |
bioleaching of metals from anaerobic sewage sludge: effects of total solids, leaching microorganisms, and energy source. | the effects of municipal sewage sludge solids concentration, leaching microorganisms (thiobacillus thiooxidans or thiobacillus ferrooxidans) and the addition of energy source (s0 or fe(ii)) on the bioleaching of metals from sewage sludge has been investigated under laboratory conditions using shake flasks. the results show that metal solubilization was better accomplished if additional energy source is supplemented to the microorganisms and that t. thiooxidans furnishes, in general, more adequat ... | 2001 | 11460332 |
interactions of three eco-types of acidithiobacillus ferrooxidans with u(vi). | the interaction of uranium with cells of three recently described eco-types of acidithiobacillus ferrooxidans recovered from uranium mining wastes was studied. the uranium sorption studies demonstrated that the strains from these types possess different capabilities to accumulate and tolerate uranium. the amount of uranium biosorbed by all a. ferrooxidans strains increased with considerable concentrations. we have found that the representatives of type ii accumulate significantly higher amounts ... | 2001 | 11508850 |
chromosomally encoded arsenical resistance of the moderately thermophilic acidophile acidithiobacillus caldus. | arsenical resistance is important to bioleaching microorganisms because these organisms release arsenic from minerals such as arsenopyrite during bioleaching. the acidophile acidithiobacillus caldus ku was found to be resistant to the arsenical ions arsenate, arsenite, and antimony via an inducible, chromosomally encoded resistance mechanism. because no apparent alteration of the toxic ions was observed, acidithiobacillus (at.) caldus was tested to determine if it was resistant as a result of de ... | 2001 | 11523894 |
identification of a novel heterodimeric outer membrane protein of porphyromonas gingivalis by two-dimensional gel electrophoresis and peptide mass fingerprinting. | porphyromonas gingivalis is a gram-negative, anaerobic bacterium associated with chronic periodontitis. a 2d electrophoretic analysis of the outer membrane of p. gingivalis w50 revealed a dominant train of spots at 40-41 kda. the proteins in the train of spots were digested in-gel with trypsin and identified by ms. the train of spots represented two proteins, designated omp40 and omp41 that share 47% sequence identity. preparation of outer membranes in the absence of protease inhibitors resulted ... | 2001 | 11532011 |
volatilization of mercury under acidic conditions from mercury-polluted soil by a mercury-resistant acidithiobacillus ferrooxidans sug 2-2. | volatilization of mercury under acidic conditions from soil polluted with mercuric chloride (1.5 mg hg/kg soil) was studied with resting cells of a mercury-resistant strain, acidithiobacillus ferrooxidans sug 2-2. when resting cells of sug 2-2 (0.01 mg of protein) were incubated for 10 d at 30 degrees c in 20 ml of 1.6 mm sulfuric acid (ph 2.5) with ferrous sulfate (3%) and mercury-polluted soil (1 g), which contained 7.5 nmol of hg, approximately 4.1 nmol of mercury was volatilized, indicating ... | 2001 | 11676009 |
stability evaluation of a cement based waste form to microbially induced degradation. | in this study the current nuclear regulatory commission (nrc) protocol is used to evaluate the stability of tuskegee cement/cobalt chloride waste form in the presence of thiobacillus thiooxidans (t. thiooxidans). a critical examination of this protocol and identified limitations are reported also. tuskegee cement/cobalt chloride waste forms were shown to exhibit considerable instability to microbial degradation as indicated by significant physical deterioration, and increased leaching of calcium ... | 2001 | 11720262 |
isolation and phylogenetic characterization of acidophilic microorganisms indigenous to acidic drainage waters at an abandoned norwegian copper mine. | the biodiversity of culturable acidophilic microbes in three acidic (ph 2.7-3.7), metal-rich waters at an abandoned subarctic copper mine in central norway was assessed. acidophilic bacteria were isolated by plating on selective solid media, and dominant isolates were identified from their physiological characteristics and 16s rrna gene sequences. the dominant iron-oxidizing acidophile in all three waters was an acidithiobacillus ferrooxidans-like eubacterium, which shared 98% 16s rdna identity ... | 2001 | 11722543 |
the high-molecular-weight cytochrome c cyc2 of acidithiobacillus ferrooxidans is an outer membrane protein. | a high-molecular-weight c-type cytochrome, cyc2, and a putative 22-kda c-type cytochrome were detected in the membrane fraction released during spheroplast formation from acidithiobacillus ferrooxidans. this fraction was enriched in outer membrane components and devoid of cytoplasmic membrane markers. the genetics, as well as the subcellular localization of cyc2 at the outer membrane level, therefore make it a prime candidate for the initial electron acceptor in the respiratory pathway between f ... | 2002 | 11741873 |
comparison of biooxidation with carbon dioxide assimilation during bacterial growth on ferrous ion or elemental sulfur. | biomass and oxygen uptake activity profiles of a mixed bioleaching culture were studied and compared at various temperatures. bacteria were grown on ferrous ion or elemental sulfur in a micro-oxymax respirometer apparatus that allowed measurement of both oxygen consumption and carbon dioxide assimilation. balanced growth was observed between 10 degrees c and 35 degrees c, with an optimum at 30 degrees c, on both energy sources. no significant growth was observed at the lowest temperature used, 5 ... | 2002 | 11745179 |
molecular characterization of acidithiobacillus ferrooxidans and a. thiooxidans strains isolated from mine wastes in brazil. | nineteen strains of acidithiobacillus ferrooxidans and acidithiobacillus thiooxidans, including 12 strains isolated from coal, copper, gold and uranium mines in brazil, strains isolated from similar sources in other countries and the type strains of the two species were characterized together with the type strain of a. caldus by using a combination of molecular systematic methods, namely ribotyping, box- and eric-pcr and dna-dna hybridization assays. data derived from the molecular fingerprintin ... | 2001 | 11761368 |
analysis of the microbial communities on corroded concrete sewer pipes--a case study. | conventional as well as molecular techniques have been used to determine the microbial communities present on the concrete walls of sewer pipes. the genetic fingerprint of the microbiota on corroded concrete sewer pipes was obtained by means of denaturing gradient gel electrophoresis (dgge) of 16s rrna gene fragments. the dgge profiles of the bacterial communities present on the concrete surface changed as observed by shifts occurring at the level of the dominance of bands from non-corroded plac ... | 2001 | 11778893 |