| quantitative speciation of sulfur in bacterial sulfur globules: x-ray absorption spectroscopy reveals at least three different species of sulfur. | x-ray absorption near edge structure (xanes) spectroscopy at the sulfur k-edge was applied to probe the speciation of sulfur of metabolically different sulfur-accumulating bacteria in situ. fitting the spectra using a least-square fitting routine xanes reveals at least three different forms of sulfur in bacterial sulfur globules. cyclooctasulfur dominates in the sulfur globules of beggiatoa alba and the very recently described giant bacterium thiomargarita namibiensis. a second type of sulfur gl ... | 2002 | 11782519 |
| characterization of the peti and res operons of acidithiobacillus ferrooxidans. | dna sequence analysis and bioinformatic interpretations have identified two adjacent clusters of genes potentially involved in the formation of a bc1 complex and in the maturation of a cytochrome c-type protein in two strains (atcc 19859 and atcc 33020) of the acidophilic, chemolithoautotrophic bacterium acidithiobacillus ferrooxidans (formerly thiobacillus ferrooxidans). reverse transcriptase-pcr experiments suggest that the two clusters are organized as operons, and +1 start sites of transcrip ... | 2002 | 11844787 |
| kinetic studies on elemental sulfur oxidation by acidithiobacillus ferrooxidans: sulfur limitation and activity of free and adsorbed bacteria. | the kinetics of sulfur oxidation by acidithiobacillus ferrooxidans in shaking flasks and a 10-l reactor was studied. the observed linearity of growth and sulfur oxidation was explained by sulfur limitation. total cell yield was not significantly different for exponential growth as compared to growth during the sulfur-limiting phase. kinetic studies of sulfur oxidation by growing and nongrowing bacteria indicated that both free and adsorbed bacteria oxidize sulfur. changes in the number of free b ... | 2002 | 11857277 |
| differential gene expression in response to copper in acidithiobacillus ferrooxidans analyzed by rna arbitrarily primed polymerase chain reaction. | acidithiobacillus ferrooxidans is a chemoautotrophic bacterium that plays an important role in metal bioleaching processes. despite the high level of tolerance to heavy metals shown by a. ferrooxidans, the genetic basis of copper resistance in this species remains unknown. we investigated the gene expression in response to copper in a. ferrooxidans lr using rna arbitrarily primed polymerase chain reaction (rap-pcr). one hundred and four differentially expressed genes were identified using eight ... | 2002 | 11870759 |
| evaluation of microbial stability of simulated solid and liquid waste forms using a refined biofilm formation method. | a refined biofilm formation method was used to evaluate the stability of a simulated liquid waste form containing a simulated liquid waste (salts) and cement in three different proportions, and a simulated solid waste form containing a simulated solid waste (resin) and cement in three different proportions. the experimental samples of all the simulated liquid waste forms showed evidence of microbial growth on them after 3 days of evaluation as indicated by substantial increase in sulfate product ... | 2002 | 11893426 |
| application of capillary zone electrophoresis to study the properties of rhodanese from acidithiobacillus ferrooxidans. | a new capillary zone electrophoretic method was applied to the assay of enzymic activity of rhodanese from acidithiobacillus ferroxidans. the enzyme activity determined by capillary zone electrophoresis was compared with that determined by discontinuous spectrophotometry, the values obtained being in good agreement. the method was also used to evaluate michaelis constants of cyanide and thiocyanate as substrates; a new approach was developed to solve the problem with variable ionic strength of t ... | 2001 | 11899469 |
| anaerobic respiration using fe(3+), s(0), and h(2) in the chemolithoautotrophic bacterium acidithiobacillus ferrooxidans. | the chemolithoautotrophic bacterium acidithiobacillus ferrooxidans has been known as an aerobe that respires on iron and sulfur. here we show that the bacterium could chemolithoautotrophically grow not only on h(2)/o(2) under aerobic conditions but also on h(2)/fe(3+), h(2)/s(0), or s(0)/fe(3+) under anaerobic conditions. anaerobic respiration using fe(3+) or s(0) as an electron acceptor and h(2) or s(0) as an electron donor serves as a primary energy source of the bacterium. anaerobic respirati ... | 2002 | 11914338 |
| an exported rhodanese-like protein is induced during growth of acidithiobacillus ferrooxidans in metal sulfides and different sulfur compounds. | by proteomic analysis we found a 21-kda protein (p21) from acidithiobacillus ferrooxidans atcc 19859 whose synthesis was greatly increased by growth of the bacteria in pyrite, thiosulfate, elemental sulfur, cus, and zns and was almost completely repressed by growth in ferrous iron. after we determined the n-terminal amino acid sequence of p21, we used the available preliminary genomic sequence of a. ferrooxidans atcc 23270 to isolate the dna region containing the p21 gene. the nucleotide sequenc ... | 2002 | 11916703 |
| evolution of sucrose synthesis. | cyanobacteria and proteobacteria (purple bacteria) are the only prokaryotes known to synthesize sucrose (suc). suc-p synthase, suc-phosphatase (spp), and suc synthase activities have previously been detected in several cyanobacteria, and genes coding for suc-p synthase (sps) and suc synthase (sus) have been cloned from synechocystis sp. pcc 6803 and anabaena (nostoc) spp., respectively. an open reading frame in the synechocystis genome encodes a predicted 27-kd polypeptide that shows homology to ... | 2002 | 11950997 |
| formation of iodinin by a strain of acidithiobacillus ferrooxidans grown on elemental sulfur. | the presence of the pigment iodinin, an acidithiobacillus ferrooxidans culture metabolite, was demonstrated after growth of bacteria on elemental sulfur. the structure of iodinin was confirmed by x-ray structure analysis; its physiological role is discussed. | 2002 | 11980275 |
| microbial influenced degradation of solidified waste binder. | ordinary cement pastes with water/cement (w/c) ratios of 0.2, 0.4 and 0.5 were used to examine the chemical and physical effects of microbial influenced degradation (mid). samples were exposed to an active culture of thiobacillus thiooxidans or to sterile media containing sulphuric acid using an intermittent immersion technique. acid consumption and ca, al and fe releases are presented for an exposure period of 90 days. exposed samples were also sectioned and analysed by scanning electron micros ... | 2002 | 12003147 |
| cytochromes c of acidithiobacillus ferrooxidans. | the chemolithoautotrophic gram-negative bacterium acidithiobacillus ferrooxidans is versatile and can grow on a number of electron donors and acceptors. in the a. ferrooxidans atcc 23270 genome, computer analysis identified 11 genes encoding putative cytochromes c. at least eight putative cytochromes c were differentiated on gels in atcc 33020 cells grown on ferrous iron or sulfur. all these cytochromes were associated with the inner or the outer membranes. lower levels of total cytochromes c we ... | 2002 | 12007804 |
| atp generation during reduced inorganic sulfur compound oxidation by acidithiobacillus caldus is exclusively due to electron transport phosphorylation. | the synthesis of adenosine 5-triphosphate (atp) (increase in phosphorylation potential) during the oxidation of reduced inorganic sulfur compounds was studied in the moderately thermophilic acidophileacidithiobacillus caldus (strain ku) (formerly thiohacillus caldus). the phosphorylation potential increased during the oxidation of all reduced inorganic sulfur compounds tested compared with resting cells. the generation of atp in whole cells was inhibited by the f0f1 atpase inhibitor oligomycin, ... | 2002 | 12013432 |
| two copies of form i rubisco genes in acidithiobacillus ferrooxidans atcc 23270. | acidithiobacillus ferrooxidans atcc 23270 possesses two copies of form i ribulose bisphosphate carboxylase/oxygenase (rubisco). the nucleotide sequence identity between the two large and two small subunit peptides was 75% and 58%, respectively. it is proposed that the two copies resulted from lateral gene transfer. | 2002 | 12070689 |
| acidophiles of saline water at thermal vents of vulcano, italy. | dna was extracted from samples taken from close to acidic hydrothermal vents on shore of the aeolian island of vulcano (italy). rna gene sequences were amplified by pcr, cloned, and sequenced. a sequence with an origin in samples at 35 degrees and 45 degrees c corresponded to that of a novel acidithiobacillus species that was isolated from water close to the vents. novel, iron-oxidizing mesophilic acidophiles were isolated through enrichment cultures with ferrous iron but were not represented in ... | 2002 | 12072955 |
| [strain polymorphism of the plasmid profiles in acidithiobacillus ferrooxidans]. | plasmid profiles were studied in 27 acidithiobacillus ferrooxidans strains isolated from different geographic zones and substrates differing in the composition of the main sulfide minerals, and also in experimentally obtained strains with acquired enhanced resistance to the ions of heavy metals (fe, ni, cu, zn, as). in 16 out of 20 strains isolated from different substrates, one to four 2- to 20-kb and larger plasmids were revealed. plasmids were found in all five strains isolated from gold-cont ... | 2002 | 12138760 |
| a global non-conjugative tet c plasmid, pras3, from aeromonas salmonicida. | two 11.8 kb non-conjugative, but mobilizable r plasmids designated pras3.1 and pras3.2 were isolated from aeromonas salmonicida subspecies salmonicida and atypical a. salmonicida, respectively. differences between the plasmids were of minor extent and they are considered as being variants of the same plasmid, pras3. the genes repa, repb, moba, mobc, mobd, and mobe were organized similar to corresponding genes in the small, mobilizable plasmid ptf-fc2 isolated from acidithiobacillus ferrooxidans ... | 2002 | 12151232 |
| molecular and atomic analysis of uranium complexes formed by three eco-types of acidithiobacillus ferrooxidans. | a combination of exafs, transmission electron microscopy and energy-dispersive x-ray was used to conduct a molecular and atomic analysis of the uranium complexes formed by acidithiobacillus ferrooxidans. the results demonstrate that this bacterium accumulates uranium as phosphate compounds. we suggest that at toxic levels when the uranium enters the bacterial cells, a. ferrooxidans can detoxify and efflux this metal by a process in which its polyphosphate bodies are involved. | 2002 | 12196160 |
| biochemical and molecular characterization of the nad(+)-dependent isocitrate dehydrogenase from the chemolithotroph acidithiobacillus thiooxidans. | an isocitrate dehydrogenase (icdh) with an unique coenzyme specificity from acidithiobacillus thiooxidans was purified and characterized, and its gene was cloned. the native enzyme was homodimeric with a subunit of m(r) 45000 and showed a 78-fold preference for nad(+) over nadp(+). the cloned icdh gene (icd) was expressed in an icd-deficient strain of escherichia coli eb106; the activity was found in the cell extract. the gene encodes a 429-amino acid polypeptide and is located between open read ... | 2002 | 12204383 |
| the bc(1) complex of the iron-grown acidophilic chemolithotrophic bacterium acidithiobacillus ferrooxidans functions in the reverse but not in the forward direction. is there a second bc(1) complex? | acidithiobacillus ferrooxidans is an acidophilic chemolithotrophic bacterium that can grow in the presence of either a weak reductant, fe(2+), or reducing sulfur compounds that provide more energy for growth than fe(2+). here we first review the latest findings about the uphill electron transfer pathway established in iron-grown a. ferrooxidans, which has been found to involve a bc(1) complex. we then provide evidence that this bc(1) complex cannot function in the forward direction (exergonic re ... | 2002 | 12206888 |
| novel electrochemical-enzymatic model which quantifies the effect of the solution eh on the kinetics of ferrous iron oxidation with acidithiobacillus ferrooxidans. | the influence of solution eh on the rate of ferrous iron oxidation by acidithiobacillus ferrooxidans is characterized. the experimental approach was based on the use of a two-chamber bioelectrochemical cell, which can determine the ferrous iron oxidation rate at controlled potential. results enabled the formulation of a novel kinetic model, which incorporates the effect of solution eh in an explicit form but still integrates the effect of ferrous iron concentration and ferric inhibition. the res ... | 2002 | 12226860 |
| [characteristics of the restriction profile of chromosomal dna in strains of acidithiobacillus ferroxidans, adapted to various oxidation substrates]. | restriction profiles of chromosomal dna were studied in different acidithiobacillus ferrooxidans strains grown on medium with fe2+ and further adapted to another oxidation substrate (s0, fes2, or sulfide ore concentrates). the restriction endonuclease xbai digested the chromosomal dna from different strains into different numbers of fragments of various sizes. adaptation of two strains (tfbk and tfn-d) to new oxidation substrates resulted in structural changes in xbai-restriction patterns of the ... | 2002 | 12244722 |
| microbial diversity in an in situ reactor system treating monochlorobenzene contaminated groundwater as revealed by 16s ribosomal dna analysis. | a molecular approach based on the construction of 16s ribosomal dna clone libraries was used to investigate the microbial diversity of an underground in situ reactor system filled with the original aquifer sediments. after chemical steady state was reached in the monochlorobenzene concentration between the original inflowing groundwater and the reactor outflow, samples from different reactor locations and from inflowing and outflowing groundwater were taken for dna extraction. small-subunit rrna ... | 2002 | 12353878 |
| monitoring of a pyrite-oxidising bacterial population using dna single-strand conformation polymorphism and microscopic techniques. | the single-strand conformation polymorphism (sscp) technique was used to study the evolution of a bacterial consortium during the batch oxidation of a cobaltiferous pyrite in two types of bio-reactor: a bubble column and a classical stirred tank. sequencing 16s rdna revealed the presence of three organisms affiliated to leptospirillum ferrooxidans, acidithiobacillus thiooxidans and sulfobacillus thermosulfidooxidans, respectively. attempts were made to determine the proportions of bacteria attac ... | 2002 | 12382065 |
| inducible aluminum resistance of acidiphilium cryptum and aluminum tolerance of other acidophilic bacteria. | aluminum ions are highly soluble in acidic environments. toxicity of aluminum ions for heterotrophic, facultatively and obligately chemolithoautotrophic acidophilic bacteria was examined. acidiphilium cryptum grew in glucose-mineral medium, ph 3, containing 300 mm aluminum sulfate [al(2)(so(4))(3)] after a lag phase of about 120 h with a doubling time of 7.6 h, as compared to 5.2 h of growth without aluminum. precultivation with 1 mm al(2)(so(4))(3) and transfer to a medium with 300 mm al(2)(so( ... | 2002 | 12420179 |
| the divergent chromosomal ars operon of acidithiobacillus ferrooxidans is regulated by an atypical arsr protein. | the chromosomal arsenic-resistance (ars) operon of acidithiobacillus ferrooxidans is atypical in that it is divergent, with its arscr and arsbh genes transcribed in opposite directions. furthermore, the amino-acid sequence of the putative arsr-like regulator of the ars operon is not conserved in regions that have been shown to be responsible for binding to arsenic. instead, the arsr-like protein of at. ferrooxidans is related to a group of unstudied arsr-like proteins that have been found to be ... | 2002 | 12480902 |
| a dispensable peptide from acidithiobacillus ferrooxidans tryptophanyl-trna synthetase affects trna binding. | the activation domain of class i aminoacyl-trna synthetases, which contains the rossmann fold and the signature sequences high and kmsks, is generally split into two halves by the connective peptides (cp1, cp2) whose amino acid sequences are idiosyncratic. cp1 has been shown to participate in the binding of trna as well as the editing of the reaction intermediate aminoacyl-amp or the aminoacyl-trna. no function has been assigned to cp2. the amino acid sequence of acidithiobacillus ferrooxidans t ... | 2002 | 12482597 |
| influence of heterotrophic microbial growth on biological oxidation of pyrite. | the rate and extent of pyrite oxidation by the iron-oxidizing bacteria acidithiobacillus ferrooxidans was limited by the growth of the heterotrophic microbe acidiphilium acidophilum. in batch systems containing a mixture of both organisms, the maximum zero-order rate of ferric iron accumulation was about 1.4 mg of fe3+ l(-1) d(-1) as compared to 9.4 mg of fe3+ l(-1) d(-1) for pure cultures of a. ferrooxidans under the same conditions. pyrite oxidation was limited in cases where both cultures of ... | 2002 | 12521179 |
| denitrification of industrial wastewater with sulfur and limestone packed column. | an autotrophic denitrification system was developed for nitrate contaminated industrial wastewater whose c/n ratio was very low. the microbes containing thiobacillus denitrificans as a dominant species were attached on the surface of granular elemental sulfur packed in a column. elemental sulfur was used as an electron donor for autotrophic denitrification. the granules of limestone were mixed with the granular sulfur to moderate the decrease of alkalinity during autotrophic denitrification. the ... | 2002 | 12523739 |
| complexation of uranium (vi) by three eco-types of acidithiobacillus ferrooxidans studied using time-resolved laser-induced fluorescence spectroscopy and infrared spectroscopy. | time-resolved laser-induced fluorescence spectroscopy (trlfs) was used to study the properties of uranium complexes (emission spectra and fluorescence lifetimes) formed by the cells of the three recently described eco-types of acidithiobacillus ferrooxidans. the results demonstrated that these complexes have different lifetimes which increase in the same order as the capability of the strains to accumulate uranium. the complexes built by the cells of the eco-type ii were the strongest, whereas, ... | 2003 | 12572691 |
| numerical modeling of ferrous-ion oxidation rate in acidithiobacillus ferrooxidans atcc 23270: optimization of culture conditions through statistically designed experiments. | statistically designed experimental strategy has been performed in order to evaluate and optimize nutritional and environmental parameters that affect ferrous ion oxidation rate in acidithiobacillus ferrooxidans atcc 23270. plackett-burman design was carried out to evaluate efficiently the biological significance of 10 culture conditions influencing ferrous-ion oxidation rate of a. ferrooxidans grown for 5 days in shake-flask batch mode on the newly modified 9-k media. among ten fermentation fac ... | 2002 | 12588097 |
| phylogenetic heterogeneity of the species acidithiobacillus ferrooxidans. | polyphasic genotypic analysis of 25 acidithiobacillus ferrooxidans strains isolated from ores and ore concentrates collected in different regions of the world showed considerable strain heterogeneity. restriction patterns of the chromosomal dna of these strains obtained by pfge were specific for each strain. according to the degree of dna relatedness, 17 of the 23 strains studied were divided into four genomovars. six independent, considerably divergent strains could not be assigned to any of th ... | 2003 | 12656161 |
| marine acidophilic sulfur-oxidizing bacterium requiring salts for the oxidation of reduced inorganic sulfur compounds. | an acidophilic sulfur-oxidizing bacterium was isolated from seawater, and designated as strain sh. strain sh was a gram-negative, rod-shaped and motile bacterium, which had an optimum temperature and ph value for growth of 30 degrees c and 4.0, respectively. the mol% guanine plus cytosine of the dna was 46.0. chemolithotrophic growth was observed with elemental sulfur and tetrathionate at ph 4.0, and was not observed with ferrous ion. the isolate was able to utilize carbon dioxide as a carbon so ... | 2003 | 12664261 |
| enumeration and characterization of acidophilic microorganisms isolated from a pilot plant stirred-tank bioleaching operation. | microorganisms were enumerated and isolated on selective solid media from a pilot-scale stirred-tank bioleaching operation in which a polymetallic sulfide concentrate was subjected to biologically accelerated oxidation at 45 degrees c. four distinct prokaryotes were isolated: three bacteria (an acidithiobacillus caldus-like organism, a thermophilic leptospirillum sp., and a sulfobacillus sp.) and one archaeon (a ferroplasma-like isolate). the relative numbers of these prokaryotes changed in the ... | 2003 | 12676667 |
| sem and afm images of pyrite surfaces after bioleaching by the indigenous thiobacillus thiooxidans. | the bioleaching mechanism of pyrite by the indigenous thiobacillus thiooxidans was examined with the aid of scanning electron microscopy (sem) and atomic force microscopy (afm) images of the pyrite surface. the presence of pyrite eliminated the lag phase during growth of this microorganism. this was due to the stimulatory effect on cell growth of the slight amount of cu2+ that had leached from the pyrite. zn2+ was found to be much more readily solubilized than cu2+. the efficiency of bioleaching ... | 2003 | 12719934 |
| the structure of acidithiobacillus ferrooxidans c(4)-cytochrome: a model for complex-induced electron transfer tuning. | the study of electron transfer between the copper protein rusticyanin (rcy) and the c(4)-cytochrome cyc(41) of the acidophilic bacterium acidithiobacillus ferrooxidans has evidenced a remarkable decrease of rcy's redox potential upon complex formation. the structure of the cyc(41) obtained at 2.2 a resolution highlighted a specific glutamate residue (e121) involved in zinc binding as potentially playing a central role in this effect, required for the electron transfer to occur. epr and stopped-f ... | 2003 | 12737820 |
| bacterial formation of tooeleite and mixed arsenic(iii) or arsenic(v)-iron(iii) gels in the carnoulès acid mine drainage, france. a xanes, xrd, and sem study. | the oxidation of fe(ii) in acid mine drainage (amd) leads to the precipitation of fe(iii) compounds which may incorporate toxic elements, such as arsenic (as), within their structure or adsorb them at their surface, thus limiting their mobility. the present work provides evidence for spatial and seasonal variations of microbial activity that influence arsenite oxidation and as immobilization in the heavily contaminated amd from the carnoulès mine, gard, france ([as iii] = 80 to 280 mg x l(-1) in ... | 2003 | 12775038 |
| leaching characteristics of heavy metals from sewage sludge by acidithiobacillus thiooxidans met. | an acidophilic, sulfur-oxidizing acidithiobacillus thiooxidans met bacterium was isolated from anaerobically digested, dewatered sewage sludge. this bacterium showed sulfur-oxidizing ability at both acidic and neutral conditions, and allowed metal leaching even at a high (130 g l(-1)) sludge solids concentration. we found that low metal leaching efficiency at high solids concentration was mainly due to an increase in buffering capacity resulting in retardation of ph reduction. therefore, metal l ... | 2003 | 12809275 |
| respiratory isozyme, two types of rusticyanin of acidithiobacillus ferrooxidans. | among the members of the copper protein superfamily, the type i enzyme rusticyanin, which is found as an electron carrier in the oxidative respiratory chain of acidithiobacillus ferrooxidans, is the only one to have both a high redox potential and acid stability. here we report that two forms of the rusticyanin gene (rus) are present in the genomes of some strains of a. ferrooxidans. the more common form of rus (type-a) was found to be present in all six strains studied, including those harborin ... | 2003 | 12834281 |
| characterization and identification of an iron-oxidizing, leptospirillum-like bacterium, present in the high sulfate leaching solution of a commercial bioleaching plant. | most copper bioleaching plants operate with a high concentration of sulfate salts, caused by the continuous addition of sulfuric acid and the recycling of the leaching solution. since the bacteria involved in bioleaching have been generally isolated at low sulfate concentrations, the bacterial population present in the high-sulfate (150 gl(-1)) leaching solution, employed in a copper production plant, was investigated. the iron-oxidizing bacteria able to grow in the leaching solution were enrich ... | 2003 | 12837511 |
| the sulfane sulfur of persulfides is the actual substrate of the sulfur-oxidizing enzymes from acidithiobacillus and acidiphilium spp. | to identify the actual substrate of the glutathione-dependent sulfur dioxygenase (ec 1.13.11.18) elemental sulfur oxidation of the meso-acidophilic acidithiobacillus thiooxidans strains dsm 504 and k6, acidithiobacillus ferrooxidans strain r1 and acidiphilium acidophilum dsm 700 was analysed. extraordinarily high specific sulfur dioxygenase activities up to 460 nmol x min(-1) (mg protein)(-1) were found in crude extracts. all cell-free systems oxidized elemental sulfur only via glutathione persu ... | 2003 | 12855721 |
| conversion of an obligate autotrophic bacteria to heterotrophic growth: expression of a heterogeneous phosphofructokinase gene in the chemolithotroph acidithiobacillus thiooxidans. | a plasmid psdk-1 containing the escherichia coli phosphofructokinase-1 gene (pfka) was constructed, and transferred into acidithiobacillus thiooxidans tt-7 by conjugation. the pfka gene from e. coli could be expressed in this obligately autotrophic bacterium but the enzyme activity (18 u g-1) was lower than that in e. coli (k12: 86 u g-1; df1010 carrying plasmid psdk-1: 97 u g-1). in the presence of glucose, the tt-7 transconjugant consumed glucose leading to a better growth yield. | 2003 | 12882002 |
| biooxidation of ferrous iron by immobilized acidithiobacillus ferrooxidans in poly(vinyl alcohol) cryogel carriers. | pva-cryogels entrapping about 10(9) cells of acidithiobacillus ferrooxidans per ml of gel were prepared by freezing-thawing procedure, and the biooxidation of fe2+ by immobilized cells was investigated in a 0.365 l packed-bed bioreactor. fe2+ oxidation fits a plug-flow reaction model well. a maximum oxidation rate of 3.1 g fe2+ l(-1) h(-1) was achieved at the dilution rate of 0.4 h(-1) or higher, while no obvious precipitate was determined at this time. in addition, cell-immobilized pva-cryogels ... | 2003 | 12882579 |
| the effects of metabolites from the indigenous acidithiobacillus thiooxidans and temperature on the bioleaching of cadmium from soil. | the effect of metabolites from the indigenous acidithiobacillus thiooxidans and temperature on the bioleaching of cadmium from soil was investigated in the present study. bioleaching was found to be more effective than chemical leaching of cadmium. the metabolite, mainly sulfuric acid, which was shown to be growth-associated in the exponential phase, plays a major role in bioleaching. the maximum amount of cadmium leached was obtained after 8 days of precultivation when cells were directly invol ... | 2003 | 12889028 |
| microbial ecology of an extreme acidic environment, the tinto river. | the tinto river (huelva, southwestern spain) is an extreme environment with a rather constant acidic ph along the entire river and a high concentration of heavy metals. the extreme conditions of the tinto ecosystem are generated by the metabolic activity of chemolithotrophic microorganisms thriving in the rich complex sulfides of the iberian pyrite belt. molecular ecology techniques were used to analyze the diversity of this microbial community. the community's composition was studied by denatur ... | 2003 | 12902280 |
| volatilization of mercury by an iron oxidation enzyme system in a highly mercury-resistant acidithiobacillus ferrooxidans strain mon-1. | a highly mercury-resistant strain acidithiobacillus ferrooxidans mon-1, was isolated from a culture of a moderately mercury-resistant strain, a. ferrooxidans sug 2-2 (previously described as thiobacillus ferrooxidans sug 2-2), by successive cultivation and isolation of the latter strain in a fe2+ medium with increased amounts of hg2+ from 6 microm to 20 microm. the original stain sug 2-2 grew in a fe2+ medium containing 6 microm hg2+ with a lag time of 22 days, but could not grow in a fe2+ mediu ... | 2003 | 12913298 |
| analysis of the mobilization region of the broad-host-range incq-like plasmid ptc-f14 and its ability to interact with a related plasmid, ptf-fc2. | plasmid ptc-f14 is a 14.2-kb plasmid isolated from acidithiobacillus caldus that has a replicon that is closely related to the promiscuous, broad-host-range incq family of plasmids. the region containing the mobilization genes was sequenced and encoded five mob proteins that were related to those of the dna processing (dtr or tra1) region of incp plasmids rather than to the three-mob-protein system of the incq group 1 plasmids (e.g., plasmid rsf1010 or r1162). plasmid ptc-f14 is the second examp ... | 2003 | 14526022 |
| [leptospirillum-like bacteria and their role in pyrite oxidation]. | two strains of leptospirillum-like bacteria isolated from dumps of alaverdi and akhtala sulfide ore deposits in armenia were studied. the optimum and maximum temperatures for the growth of both strains were 37 and 40 degrees c, respectively. the ph optimum was 2.0-2.3. bacterial growth and ferrous iron oxidation were inhibited by yeast extract. the pyrite-leaching activity of the leptospirillum-like bacteria under mesophilic conditions was close to that of acidithiobacillus ferroxidans and excee ... | 2003 | 14526539 |
| immobilization of arsenite and ferric iron by acidithiobacillus ferrooxidans and its relevance to acid mine drainage. | weathering of the as-rich pyrite-rich tailings of the abandoned mining site of carnoulès (southeastern france) results in the formation of acid waters heavily loaded with arsenic. dissolved arsenic present in the seepage waters precipitates within a few meters from the bottom of the tailing dam in the presence of microorganisms. an acidithiobacillus ferrooxidans strain, referred to as cc1, was isolated from the effluents. this strain was able to remove arsenic from a defined synthetic medium onl ... | 2003 | 14532077 |
| bioleaching review part a: progress in bioleaching: fundamentals and mechanisms of bacterial metal sulfide oxidation. | bioleaching of metal sulfides is caused by astonishingly diverse groups of bacteria. today, at least 11 putative prokaryotic divisions can be related to this phenomenon. in contrast, the dissolution (bio)chemistry of metal sulfides follows only two pathways, which are determined by the acid-solubility of the sulfides: the thiosulfate and the polysulfide pathway. the bacterial cell can effect this sulfide dissolution by "contact" and "non-contact" mechanisms. the non-contact mechanism assumes tha ... | 2003 | 14566432 |
| a new method using a bacterium for dissolution of urinary stones. | a bacterium, thiobacillus thiooxidans, oxidizes inorganic sulfur compounds to sulfuric acid to obtain energy for growth. we examined dissolution of urinary stones by the bacteria and studied optimal conditions for the dissolution in human urine. | 2003 | 14566677 |
| coevolution of an aminoacyl-trna synthetase with its trna substrates. | glutamyl-trna synthetases (glurss) occur in two types, the discriminating and the nondiscriminating enzymes. they differ in their choice of substrates and use either trnaglu or both trnaglu and trnagln. although most organisms encode only one glurs, a number of bacteria encode two different glurs proteins; yet, the trna specificity of these enzymes and the reason for such gene duplications are unknown. a database search revealed duplicated glurs genes in >20 bacterial species, suggesting that th ... | 2003 | 14615592 |
| linking autotrophic activity in environmental samples with specific bacterial taxa by detection of 13c-labelled fatty acids. | a method for the detection of physiologically active autotrophic bacteria in complex microbial communities was developed based on labelling with the stable isotope 13c. labelling of autotrophic nitrifying, sulphur-oxidizing and iron-oxidizing populations was performed in situ by incubation with nah[13c]o3. incorporated label into fatty acid methyl esters (fames) was detected and quantified using gas chromatography-mass spectrometry in single ion monitoring mode. before the analyses of different ... | 2003 | 14641595 |
| reduction of vanadium(v) with acidithiobacillus ferrooxidans and acidithiobacillus thiooxidans. | biotechnological leaching has been proposed as a suitable method for extraction of vanadium from spent catalysts and oil ash. in the biological leaching process, the vanadium(v) can be reduced to vanadium(iv), which is a less toxic and more soluble form of the vanadium. the present investigation showed that acidithiobacillus ferrooxidans efficiently reduced vanadium(v) in the form of vanadium pentaoxide, to vanadyl(iv) ions, and tolerated high concentrations of vanadium(iv) and vanadium(v). a. f ... | 2004 | 14643991 |
| metabolic reconstruction of sulfur assimilation in the extremophile acidithiobacillus ferrooxidans based on genome analysis. | acidithiobacillus ferrooxidans is a gamma-proteobacterium that lives at ph2 and obtains energy by the oxidation of sulfur and iron. it is used in the biomining industry for the recovery of metals and is one of the causative agents of acid mine drainage. effective tools for the study of its genetics and physiology are not in widespread use and, despite considerable effort, an understanding of its unusual physiology remains at a rudimentary level. nearly complete genome sequences of a. ferrooxidan ... | 2003 | 14675496 |
| [plasmid profiles of acidithiobacillus ferrooxidans strains adapted to different oxidation substrates]. | plasmid profiles were studied in five acidithiobacillus ferrooxidans strains of various origin cultivated on medium with fe2+, as well as adapted to such oxidation substrates as s0, fes2, and sulfide concentrate. the method used revealed plasmids in all a. ferrooxidans strains grown on medium with fe2+. one plasmid was found in strain tfl-2, two plasmids, in strains tfo, tfbk, and tfv-1, and three plasmids were detected in strain tfn-d. the adaptation of strain tfn-d to sulfide concentrate and t ... | 2003 | 14679904 |
| localization, purification and properties of a tetrathionate hydrolase from acidithiobacillus caldus. | the moderately thermophilic bacterium acidithiobacillus caldus is found in bacterial populations in many bioleaching operations throughout the world. this bacterium oxidizes elemental sulfur and other reduced inorganic sulfur compounds as the sole source of energy. the purpose of this study was to purify and characterize the tetrathionate hydrolase of a. caldus. the enzyme was purified 16.7-fold by one step chromatography using a sp sepharose column. the purified enzyme resolved into a single ba ... | 2004 | 14717695 |
| bioleaching of heavy metals from anaerobically digested sewage sludge using fes2 as an energy source. | the effect of using fes2 as an energy source, on the bioleaching of heavy metals (zn, cr, cu, pb and ni) and nutrients (nitrogen and phosphorus) from anaerobically digested sludge using isolated indigenous iron-oxidizing bacteria was investigated in this paper. addition of fes2 in the range of 0.5-4.0 g l(-1) accelerated the acidification of sludge and raised the oxidation-reduction potential of sludge medium with an inoculation of 15% (v/v) of active bacteria, thus resulting in an overall incre ... | 2004 | 14720552 |
| [bioleaching kinetic of a pyrite mining residue using organic wastes as culture media for acidithiobacillus ferrooxidans]. | in this study, the results of the leaching of metal sulphide concentrate using organic wastes as culture media for acidithiobacillus ferrooxidans are summarized. these results indicate that the liquid fraction of municipal sewage sludge, paper mill sludge and pig manure, containing 10% (w v(-1)) pulp density of a pyritic mine waste concentrate can support the growth of the leaching bacteria and allow metal solubilization. the inhibition by dissolved organic carbon (doc) appeared when the concent ... | 2003 | 14733394 |
| in vivo formation of glutamyl-trna(gln) in escherichia coli by heterologous glutamyl-trna synthetases. | two types of glutamyl-trna synthetase exist: the discriminating enzyme (d-glurs) forms only glu-trna(glu), while the non-discriminating one (nd-glurs) also synthesizes glu-trna(gln), a required intermediate in protein synthesis in many organisms (but not in escherichia coli). testing the capacity to complement a thermosensitive e. coli gltx mutant and to suppress an e. coli trpa49 missense mutant we examined the properties of heterologous gltx genes. we demonstrate that while acidithiobacillus f ... | 2004 | 14741355 |
| protein profile of acidithiobacillus ferrooxidans strains exhibiting different levels of tolerance to metal sulfates. | strains of acidithiobacillus ferrooxidans exhibited differences in the inhibition of fe2+ oxidation in the presence of 250 mm of cadmium, zinc, and manganese sulfates in respirometric assays. strains lr and 135 were practically not inhibited, whereas strains ssp and v3 showed significant inhibition (30-70%). analysis by sds-page of total proteins from cells grown in the absence of metal sulfates showed different profiles between the more tolerant strains (lr and 135) and the more susceptible one ... | 2003 | 14756533 |
| induced mutants of thiobacillus thiooxidans requiring organic growth factors. | | 1950 | 14784481 |
| high-rate ferric sulfate generation by a leptospirillum ferriphilum-dominated biofilm and the role of jarosite in biomass retention in a fluidized-bed reactor. | the aims of this work were to develop a high-rate fluidized-bed bioprocess for ferric sulfate production, to characterize biomass retention, and to determine the phylogeny of the enrichment culture. after 7 months of continuous enrichment and air aeration at 37 degrees c, the iron oxidation rate of 8.2 g fe(2+) l(-1)h(-1) (4.5.10(-12) g fe(2+) cell(-1) h(-1)) was obtained at a hydraulic retention time (hrt) of 0.6 h. however, oxygen supply became the rate-limiting factor. with gas mixture (99.5% ... | 2004 | 14991647 |
| enzymatic synthesis of lipid a molecules with four amide-linked acyl chains. lpxa acyltransferases selective for an analog of udp-n-acetylglucosamine in which an amine replaces the 3"-hydroxyl group. | lpxa of escherichia coli catalyzes the acylation of the glucosamine 3-oh group of udp-glcnac, using r-3-hydroxymyristoyl-acyl carrier protein (acp) as the donor substrate. we now demonstrate that lpxa in cell extracts of mesorhizobium loti and leptospira interrogans, which synthesize lipid a molecules containing 2,3-diamino-2,3-dideoxy-d-glucopyranose (glcn3n) units in place of glucosamine, do not acylate udp-glcnac. instead, these lpxa acyltransferases require a udp-glc-nac derivative (designat ... | 2004 | 15044493 |
| oxidation and transamination of the 3"-position of udp-n-acetylglucosamine by enzymes from acidithiobacillus ferrooxidans. role in the formation of lipid a molecules with four amide-linked acyl chains. | lipid a, a major component of the outer membranes of escherichia coli and other gram-negative bacteria, is usually constructed around a beta-1',6-linked glucosamine disaccharide backbone. however, in organisms like acidithiobacillus ferrooxidans, leptospira interrogans, mesorhizobium loti, and legionella pneumophila, one or both glucosamine residues are replaced with the sugar 2,3-diamino-2,3-dideoxy-d-glucopyranose. we now report the identification of two proteins, designated gnna and gnnb, inv ... | 2004 | 15044494 |
| analysis of community composition during moderately thermophilic bioleaching of pyrite, arsenical pyrite, and chalcopyrite. | an analysis of the community composition of three previously undefined mixed cultures of moderately thermophilic bioleaching bacteria grown at 45 degrees c on pyrite, arsenical pyrite, and chalcopyrite has been carried out. the bacterial species present were identified by comparative sequence analysis of the 16s rrna gene isolated from the bioleaching vessels and analyzed by denaturing gradient gel electrophoresis, cloning, and sequencing. the mixed cultures leached all three minerals, as shown ... | 2004 | 15085303 |
| weathering of phlogopite by bacillus cereus and acidithiobacillus ferrooxidans. | the purpose of this study was to assess the weathering of finely ground phlogopite, a trioctahedral mica, by placing it in contact with heterotrophic (bacillus cereus) and acidophilic (acidithiobacillus ferrooxidans) cultures. x-ray diffraction analyses of the phlogopite sample before and after 24 weeks of contact in b. cereus cultures revealed a decrease in the characteristic peak intensities of phlogopite, indicating destruction of individual structural planes of the mica. no new solid phase p ... | 2004 | 15105888 |
| glycine betaine as a cryoprotectant for prokaryotes. | osmoprotectants are low molecular weight, hydrophilic, nontoxic molecules that assist a cell under osmotic stress to stabilize its concentration of internal solutes. these properties are similar to compounds used as cryoprotectants for the preservation of prokaryotic cells during freezing. this study tested the ability of a common compatible solute, glycine betaine (gb), to act as a cryoprotectant. in a series of freeze-drying studies using a variety of prokaryotes, gb performed as well, or bett ... | 2004 | 15177901 |
| apparent redundancy of electron transfer pathways via bc(1) complexes and terminal oxidases in the extremophilic chemolithoautotrophic acidithiobacillus ferrooxidans. | acidithiobacillus ferrooxidans is an acidophilic chemolithoautotrophic bacterium that can grow in the presence of either the weak reductant fe(2+), or reducing sulfur compounds that provide more energy for growth than fe(2+). we have previously shown that the uphill electron transfer pathway between fe(2+) and nad(+) involved a bc(1) complex that functions only in the reverse direction [j. bacteriol. 182, (2000) 3602]. in the present work, we demonstrate both the existence of a bc(1) complex fun ... | 2004 | 15178473 |
| macrofilamentous microbial communities in the metal-rich and acidic river tinto, spain. | a novel type of macroscopic microbial community consisting of large dendritic filaments (up to 1.5 m) in a ph 2.0 dam of the river tinto (south-western spain) is described. the combined use of 16s rrna-gene surveys and fluorescent in situ hybridisation (fish) suggested that gamma-proteobacteria and a relative large diversity of alpha-proteobacteria dominated these structures. beta-proteobacteria, actinobacteria and firmicutes were also detected. whereas acidophilic bacteria of the genera acidith ... | 2004 | 15183867 |
| identification of inhibitory substances affecting bioleaching of heavy metals from anaerobically digested sewage sludge. | significant inhibitory effects of the filtrate medium of anaerobically digested sewage sludge on iron oxidation by acidithiobacillus ferrooxidans anyl-1 were observed in our preliminary experiments, indicating the presence of inhibitory substances in anaerobically digested sewage sludge. the objectives of the present study were to identify the possible inhibitory substances and to evaluate their impacts on metal solubilization during bioleaching of sewage sludge. the results showed that the conc ... | 2004 | 15212270 |
| effects of bacterial activities on the release of heavy metals from contaminated dredged sediments. | the potential impact of indigenous bacterial processes on the release of heavy metals from dredged sediment deposits was investigated. batch re-suspension experiments were conducted in order to investigate the release of zn, cd, cu and pb from a polluted anoxic sediment submitted to oxidative perturbations. the concentrations of heavy metals, sulphate and dissolved organic carbon (doc) were periodically recorded, and cell counts were performed to follow the evolution of several bacterial species ... | 2004 | 15212904 |
| oxidative dissolution of chalcopyrite by acidithiobacillus ferrooxidans analyzed by electrochemical impedance spectroscopy and atomic force microscopy. | the microbiological leaching of chalcopyrite (cufes(2)) is of great interest because of its potential application to many cufes(2)-rich ore materials. however, the efficiency of the microbiological process is very limited because this mineral is one of the most refractory to bacterial attack. knowledge of bacterial role during chalcopyrite oxidation is very important in order to improve the efficiency of bioleaching operation. the oxidative dissolution of a massive chalcopyrite electrode by acid ... | 2004 | 15219250 |
| regulation of the expression of the acidithiobacillus ferrooxidans rus operon encoding two cytochromes c, a cytochrome oxidase and rusticyanin. | the regulation of the expression of the rus operon, proposed to encode an electron transfer chain from the outer to the inner membrane in the obligate acidophilic chemolithoautroph acidithiobacillus ferrooxidans, has been studied at the rna and protein levels. as observed by northern hybridization, real-time pcr and reverse transcription analyses, this operon was more highly expressed in ferrous iron- than in sulfur-grown cells. furthermore, it was shown by immunodetection that components of thi ... | 2004 | 15256554 |
| effect of uncouplers on endogenous respiration and ferrous iron oxidation in a chemolithoautotrophic bacterium acidithiobacillus (thiobacillus) ferrooxidans. | oxidation of ferrous iron (fe2+) to ferric iron (fe3+) with oxygen (o2) by acidithiobacillus (thiobacillus) ferrooxidans is considered to be inhibited by uncouplers. oxidation of the endogenous substrates (presumably nadh) with o2 or fe3+, on the other hand, was stimulated by uncouplers, 2,4-dinitrophenol (dnp) and carbonylcyanide-m-chlorophenyl-hydrazone (cccp), as expected in respiratorily controlled mitochondria or heterotrophic bacteria. amytal and rotenone were inhibitory. fe3+ reduction by ... | 2004 | 15268949 |
| selective separation of arsenopyrite from pyrite by biomodulation in the presence of acidithiobacillus ferrooxidans. | effective methods for selective separation using flotation or flocculation of arsenopyrite from pyrite by biomodulation using acidithiobacillus ferrooxidans are presented here. adhesion of the bacterium to the surface of arsenopyrite was very slow compared to that to pyrite, resulting in a difference in surface modification of the minerals subsequent to interaction with cells. the cells were able to effectively depress pyrite flotation in presence of collectors like potassium isopropyl xanthate ... | 2004 | 15271559 |
| genetics of metal resistance in acidophilic prokaryotes of acidic mine environments. | acidophilic bacteria inhabiting acidic mine regions cause natural leaching of sulphidic ores. they are now exploited in industrial operations for leaching of metals and beneficiation of low-grade and recalcitrant ores. recent trends emphasize application of thermoacidophiles and genetic engineering of ore-leaching bacteria for greater success in this area. this requires an in-depth understanding on the molecular genetics of these bacteria and construction of cloning vectors for them. metal resis ... | 2004 | 15274476 |
| differential protein expression during growth of acidithiobacillus ferrooxidans on ferrous iron, sulfur compounds, or metal sulfides. | a set of proteins that changed their levels of synthesis during growth of acidithiobacillus ferrooxidans atcc 19859 on metal sulfides, thiosulfate, elemental sulfur, and ferrous iron was characterized by using two-dimensional polyacrylamide gel electrophoresis. n-terminal amino acid sequencing and mass spectrometry analysis of these proteins allowed their identification and the localization of the corresponding genes in the available genomic sequence of a. ferrooxidans atcc 23270. the genomic co ... | 2004 | 15294777 |
| microbial desulfurization of different coals. | coal is the most important nonrenewable energy source of fossil origin. it is also the most common fuel in thermal power plants. however, during coal incineration in power plants, high sulfur content of coal poses serious environmental problems owing to sulfur dioxide emission. we studied the application of microbial methods for removal of sulfur from three types of high sulfur coals-two samples collected from assam and rajasthan in india and one from libiaz, poland. these coal samples were desu ... | 2004 | 15304738 |
| differentiation of acidithiobacillus ferrooxidans and a. thiooxidans strains based on 16s-23s rdna spacer polymorphism analysis. | restriction fragment length polymorphism (rflp) and sequence analyses of the pcr-amplified 16s-23s rdna intergenic spacer (its) were used for differentiating acidithiobacillus thiooxidans strains from other related acidithiobacilli, including a. ferrooxidans and a. caldus. rflp fingerprints obtained with alui, ddei, haeiii, hinfi and mspi enabled the differentiation of all acidithiobacillus reference strains into species groups. the a. thiooxidans strains investigated (metal mine isolates) yield ... | 2004 | 15313256 |
| [interaction of chromosomal and plasmid dna in acidithiobacillus ferrooxidans strains adapted to different oxidation substrates]. | restriction analysis of plasmids ptfk1 and ptfk2 of the acidithiobacillus ferrooxidans strain tfbk was carried out, and the sizes of these plasmids were determined (13.5 and 30 kb, respectively). a macrorestriction map was built for plasmid ptfk1. dna-dna hybridization revealed that the plasmids contained homologous nucleotide sequences. plasmid ptfk2 labeled with 32p was used as a probe for southern hybridization with blots of xbai-generated fragments of the chromosomal dna of a. ferrooxidans s ... | 2004 | 15315231 |
| [an oligonucleotide primer system for amplification of the ribulose-1,5-bisphosphate carboxylase/oxygenase genes of bacteria of various taxonomic groups]. | based on the analysis of genbank nucleotide sequences of the cbbl and cbbm genes, coding for the large subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase (rubpc), the key enzyme of the calvin cycle, a primer system was designed that allows about 800-bp-long fragments of these genes to be pcr-ampliflied in various photo- and chemotrophic bacteria. the efficiency of the designed primer system in detection of rubpc genes was demonstrated in pcr with dna of taxonomically diverse bacteria pos ... | 2004 | 15315232 |
| [removal of cr from tannery sludge by acidophilic thiobacilli]. | the removal of cr from tannery sludge by bioleaching technology was reported in the paper. batch experiments involved the inoculation of acidophilic thiobacilli and addition of elemental sulfur as their substrate. results showed that cr removal of 100% could be obtained after 8 days of bioleaching. the oxidation of added sulfur by acidophilic thiobacilli decreased sludge ph value which caused the solubilization of cr from tannery sludge. a threshold ph of 2.0 existed for cr solubilization from t ... | 2004 | 15330423 |
| selective separation of pyrite and chalcopyrite by biomodulation. | selective separation of pyrite from other associated ferrous sulphides at acidic and neutral ph has been a challenging problem. this paper discusses the utility of acidithiobacillus ferrooxidans for the selective flotation of chalcopyrite from pyrite. consequent to interaction with bacterial cells, pyrite remained depressed even in the presence of potassium isopropyl xanthate collector while chalcopyrite exhibited significant flotability. however, when the minerals were conditioned together, the ... | 2004 | 15342018 |
| copper ions stimulate polyphosphate degradation and phosphate efflux in acidithiobacillus ferrooxidans. | for some bacteria and algae, it has been proposed that inorganic polyphosphates and transport of metal-phosphate complexes could participate in heavy metal tolerance. to test for this possibility in acidithiobacillus ferrooxidans, a microorganism with a high level of resistance to heavy metals, the polyphosphate levels were determined when the bacterium was grown in or shifted to the presence of a high copper concentration (100 mm). under these conditions, cells showed a rapid decrease in polyph ... | 2004 | 15345397 |
| biooxidation of pyrite by defined mixed cultures of moderately thermophilic acidophiles in ph-controlled bioreactors: significance of microbial interactions. | the oxidative dissolution of pyrite (fes2) by pure and mixed cultures of moderately thermophilic acidophiles was studied in shake flask cultures and in ph-controlled bioreactors, incubated at 45 degrees c. various combinations of seven eubacteria (a leptospirillum sp. (mt6), acidimicrobium ferrooxidans, acidithiobacillus caldus, an alicyclobacillus sp. (y004), and three sulfobacillus spp.) and one archaeon (ferroplasma sp. mt17) were examined. pyrite dissolution was determined by measuring chang ... | 2004 | 15352055 |
| potential biogeochemical and ecological development of a flooded tailings impoundment at the kristineberg zn-cu mine, northern sweden. | the potential short-term (<or= 10(2) years) and long-term (>10(2) years) biogeochemical and ecological effects of diverting stream water (ph 4.9-6.7) into a limed, flooded tailings impoundment (ph 8-12) were studied by combining geochemical and biological data. in the long-term perspective, the successional development of lakes was used as a natural analogue. based on the vertical distribution of temperature and total dissolved solids (tds < 0.22 microm), the impoundment can be characterised as ... | 2004 | 15364533 |
| characterization of an indigenous iron-oxidizing bacterium and its effectiveness in bioleaching heavy metals from anaerobically digested sewage sludge. | the objective of the present study was to isolate the indigenous iron-oxidizing bacterium and compare its effectiveness in bioleaching of heavy metals from fresh anaerobically digested sludge and aged sludge which had undergone a storage period in a sludge holding tank. an acidophilic iron-oxidizing bacterium acidithiobacillus ferrooxidans strain anyl-1 was successfully isolated from the sludge collected from a wastewater treatment plant at yuen long district in hong kong. it was a gram negative ... | 2004 | 15366556 |
| effects of inhibitors and nacl on the oxidation of reduced inorganic sulfur compounds by a marine acidophilic, sulfur-oxidizing bacterium, acidithiobacillus thiooxidans strain sh. | the effect of nacl and the pathways of the oxidation of reduced inorganic sulfur compounds were studied using resting cells and cell-free extracts of acidithiobacillus thiooxidans strain sh. this isolate specifically requires nacl for growth. the oxidation of sulfur and sulfite by resting cells was strongly inhibited by 2-heptyl-4-hydroxyquinoline-n-oxide. carbonylcyanide m-chlorophenyl-hydrazone and monensin were also relatively strong inhibitors. thiosulfate-oxidizing activity was not inhibite ... | 2005 | 15375674 |
| rusticyanin, a bacterial electron transfer protein, causes g1 arrest in j774 and apoptosis in human cancer cells. | during acid mine drainage, acidithiobacillus ferrooxidans, a nonpathogenic, acidophilic, lithotrophic bacterium, utilizes rusticyanin to transfer electrons for the oxidation of fe(2+) to fe(3+) for deriving its energy. no other function of rusticyanin is known. we demonstrate that purified rusticyanin enters mammalian cells inducing either inhibition of cell cycle progression or caspase-8 mediated apoptosis. treatment of human melanoma cells with rusticyanin allowed significant generation of rea ... | 2004 | 15467448 |
| reduction of arsenic content in a complex galena concentrate by acidithiobacillus ferrooxidans. | bioleaching is a process that has been used in the past in mineral pretreatment of refractory sulfides, mainly in the gold, copper and uranium benefit. this technology has been proved to be cheaper, more efficient and environmentally friendly than roasting and high pressure moisture heating processes. so far the most studied microorganism in bioleaching is acidithiobacillus ferrooxidans. there are a few studies about the benefit of metals of low value through bioleaching. from all of these, ther ... | 2004 | 15482595 |
| microbial recovery of copper from printed circuit boards of waste computer by acidithiobacillus ferrooxidans. | the bioleaching of copper contained in the printed circuit boards (pcb) of waste computers by a. ferrooxidans was studied. the fe oxidation rates by a. ferrooxidans in the 9k medium supplemented with the leachate of pcb (0.15-0.13 g l(-1) d(-1)) were similar to that in the 9k medium without the leachate (0.15 g l(-1) d(-1)). this finding suggests that the leachate of pcb did not seriously affect the bioleaching process by this bacterium. the amount of copper leached from pcb shreds increased wit ... | 2004 | 15533017 |
| treatment of h2s using a horizontal biotrickling filter based on biological activated carbon: reactor setup and performance evaluation. | biological treatment is an emerging and prevalent technology for treating off-gases from wastewater treatment plants. the most commonly reported odorous compound in off-gases is hydrogen sulfide (h(2)s), which has a very low odor threshold. a self-designed, bench-scale, cross-flow horizontal biotrickling filter (hbf) operated with bacteria immobilized activated carbon (termed biological activated carbon-bac), was applied for the treatment of h(2)s. a mixed culture of sulfide-oxidizing bacteria d ... | 2005 | 15538552 |
| the genetics of geochemistry. | bacteria are remarkable in their metabolic diversity due to their ability to harvest energy from myriad oxidation and reduction reactions. in some cases, their metabolisms involve redox transformations of metal(loid)s, which lead to the precipitation, transformation, or dissolution of minerals. microorganism/mineral interactions not only affect the geochemistry of modern environments, but may also have contributed to shaping the near-surface environment of the early earth. for example, bacterial ... | 2004 | 15568975 |
| enhanced heavy metal bioleaching efficiencies from anaerobically digested sewage sludge with coinoculation of acidithiobacillus ferrooxidans anyl-1 and blastoschizomyces capitatus y5. | prolonged bioleaching period was required to remove heavy metals from anaerobically digested sewage sludge in the presence of low molecular weight organic acids. the purpose of the present study was therefore to enhance metal solubilization efficiencies through introducing organic acid-degrading microorganisms into this artificial bioleaching system. an acetic and propionic acid-degrading yeast blastoschizomyces capitatus y5 was successfully isolated from a local yuen long sewage sludge and it c ... | 2004 | 15580998 |
| involvement of sulfide:quinone oxidoreductase in sulfur oxidation of an acidophilic iron-oxidizing bacterium, acidithiobacillus ferrooxidans nasf-1. | the effects of cyanide, azide, and 2-n-heptyl-4-hydroxy-quinoline-n-oxide (hqno) on the oxidation of ferrous ion or elemental sulfur with acidithiobacillus ferrooxidans nasf-1 cells grown in iron- or sulfur-medium were examined. the iron oxidation of both iron- and sulfur-grown cells was strongly inhibited by cyanide and azide, but not by hqno. sulfur oxidation was relatively resistant to cyanide and azide, and inhibited by hqno. higher sulfide oxidation, ubiquinol dehydrogenase activity, and su ... | 2004 | 15618623 |
| [isolation of heterotrophic microorganism and its role in bioleaching of heavy metals from tannery sludge]. | a heterotrophic microorganism was isolated from sewage sludge, it was identified as rhodotorula sp. r30. its optimum ph for growth was 3-7, but it can stand the acidity of ph 2.5-1.5. the optimum temperature was 28 degrees c. when r30 was inoculated in the medium containing dissolved organic matter derived from sewage sludge and incubated for 96 h, dissolved organic carbon in the medium declined from 1485 mg/l to 345 mg/l, and the yeast number was 4.8 x 10(7) ml(-1). it was found through the bat ... | 2004 | 15623044 |
| detection of acidithiobacillus ferrooxidans in acid mine drainage environments using fluorescent in situ hybridization (fish). | an important microorganism of acid mine drainage (amd) and bioleaching environments is acidithiobacillus ferrooxidans which oxidizes ferrous iron and generates ferric iron, an oxidant. most investigations to understand microbial aspects of sulfide mineral dissolution have focused on understanding physiological, metabolic, and genetic characteristics of a. ferrooxidans. in this study, a 16s rrna oligonucleotide probe designated s-s-t.ferr-0584-a-a-18, and labeled at the 5'-end with indocarbocyani ... | 2005 | 15676194 |
| microbial removal of uranium in uranium-bearing black shale. | the effects of several conditional factors on efficiency of u bioleaching using an iron-oxidizer, acidithiobacillus ferrooxidans, from u-bearing black shale (349 mg kg-1 of u) were investigated. when batch-type reactors containing black shale were initially inoculated with the cells, lower ph, higher redox potential and higher amount of aqueous fe3+ than those of non-inoculated reactor were observed until 200 h. such development of condition, which was facilitated by microbial activity, can enha ... | 2005 | 15698655 |
| the evolution of ptf-fc2 and ptc-f14, two related plasmids of the incq-family. | two plasmids, ptf-fc2 and ptc-f14, that belong to the incq-like plasmid family were isolated from two related bacteria, acidithiobacillus ferrooxidans and acidithiobacillus caldus, respectively. the backbone regions of the two plasmids share a sufficiently high amount of homology to indicate that they must have originated from the same ancestral plasmid. although some of their replication proteins could complement each other, the plasmids have evolved sufficiently for their replicons to have bec ... | 2005 | 15737401 |