| operational and microbiological aspects of a bioaugmented two-stage biotrickling filter removing hydrogen sulfide and dimethyl sulfide. | a two-stage biotrickling filter was developed for removing dimethyl sulfide (dms) and hydrogen sulfide (h2s). the first biotrickling filter (abf) was inoculated with acidithiobacillus thiooxidans and operated without ph control, while the second biotrickling filter (hbf) was inoculated with hyphomicrobium vs and operated at neutral ph. high dms elimination capacities were observed in the hbf (8.2 g dms m(-3) h(-1) at 90% removal efficiency) after 2 days. maximal observed elimination capacities w ... | 2005 | 15739171 |
| high-rate acidophilic ferrous iron oxidation in a biofilm airlift reactor and the role of the carrier material. | in this study, the feasibility and engineering aspects of acidophilic ferrous iron oxidation in a continuous biofilm airlift reactor inoculated with a mixed culture of acidithiobacillus ferrooxidans and leptospirillum ferrooxidans bacteria were investigated. specific attention was paid to biofilm formation, competition between both types of bacteria, ferrous iron oxidation rate, and gas liquid mass transfer limitations. the reactor was operated at a constant temperature of 30 degrees c and at ph ... | 2005 | 15772947 |
| identification of putative sulfurtransferase genes in the extremophilic acidithiobacillus ferrooxidans atcc 23270 genome: structural and functional characterization of the proteins. | eight nucleotide sequences containing a single rhodanese domain were found in the acidithiobacillus ferrooxidans atcc 23270 genome: p11, p14, p14.3, p15, p16, p16.2, p21, and p28. amino acids sequence comparisons allowed us to identify the potentially catalytic cys residues and other highly conserved rhodanese family features in all eight proteins. the genomic contexts of some of the rhodanese-like genes and the determination of their expression at the mrna level by using macroarrays suggested t ... | 2005 | 15805776 |
| biogeochemical analysis of hydrogen sulfide removal by a lava-rock packed biofilter. | although lava-rock-based biofilters have demonstrated their efficiencies for hydrogen sulfide (h2s) removal found in odorous air emissions, the biogeochemical basis for this removal is unclear. in this study, samples of lava rock and rinse water from biofilters at cedar rapids water pollution control facilities (iowa) were used to study the structure and chemical composition of lava rock and to identify the predominant microorganism(s) present in lava-rock-based biofilters. it was found that iro ... | 2005 | 15816681 |
| the use of rapd genomic fingerprinting to study relatedness in strains of acidithiobacillus ferrooxidans. | twelve strains of acidithiobacillus ferrooxidans were recovered from acid mine drainage (amd) sites from three different geographical locations: copper cliff, ontario, canada; mineral city, oh, usa; and cornwall, england. the spread-plate technique and various culture media were used to isolate and purify all strains. dna was extracted from each purified culture and amplified using pcr and twenty, 10-mer primers. amplification products were separated by gel electrophoresis and photographed under ... | 2005 | 15823398 |
| bioproduction of ferric sulfate used during heavy metals removal from sewage sludge. | toxic metals removal from wastewater sewage sludge can be achieved through microbial processes involving acidithiobacillus ferrooxidans. the oxidation of ferrous ions by a. ferrooxidans, cultured in sewage sludge filtrate, was studied in both batch and continuous flow stirred tank reactors. sewage sludge filtrate containing natural nutrients (phosphorus and nitrogen) was recovered as effluent following the dehydration of a primary and secondary sludge mixture. batch and continuous flow stirred t ... | 2005 | 15843644 |
| insight into molecular stability and physiological properties of the diheme cytochrome cyc41 from the acidophilic bacterium acidithiobacillus ferrooxidans. | the cyc1 gene encoding the soluble dihemic cytochrome c cyc(41) from acidithiobacillus ferrooxidans, an acidophilic organism, has been cloned and expressed in escherichia coli as the host organism. the cytochrome was successfully produced and folded only in fermentative conditions: this allowed us to determine the molecular basis of the heme insertion at extreme ph. point mutations at two sequence positions (e121 and y63) were introduced near the two hemes in order to assign individual redox pot ... | 2005 | 15850381 |
| use of immobilized cytochrome c as a ligand for affinity chromatography of thiosulfate dehydrogenase from acidithiobacillus ferrooxidans. | three matrices were used for immobilizing the cytochrome c: sepharose cl-4b, silasorb sph amine and a laboratory-prepared new matrix based on crosslinked triazine (2,4,6-tris(aminoethylamine)-1,3,5-triazine) (tat). cytochrome c was immobilized on the matrices by several procedures and the amount of incorporated cytochrome c was determined. cytochrome c immobilized on sepharose cl-4b with periodate activation, cytochrome c immobilized on silasorb-amine with carbodiimide activation and cytochrome ... | 2005 | 15862360 |
| the hipip from the acidophilic acidithiobacillus ferrooxidans is correctly processed and translocated in escherichia coli, in spite of the periplasm ph difference between these two micro-organisms. | the gene encoding a putative high-potential iron-sulfur protein (hipip) from the strictly acidophilic and chemolithoautotrophic acidithiobacillus ferrooxidans atcc 33020 has been cloned and sequenced. this potential hipip was overproduced in the periplasm of the neutrophile and heterotroph escherichia coli. as shown by optical and epr spectra and by electrochemical studies, the recombinant protein has all the biochemical properties of a hipip, indicating that the iron-sulfur cluster was correctl ... | 2005 | 15870452 |
| bioleaching of cr from tannery sludge: the effects of initial acid addition and recycling of acidified bioleached sludge. | a technologically feasible process called bioleaching was used to remove cr from tannery sludge with acidithiobacilli ts6 bacteria in this study. the buffering capacity of tannery sludge and municipal sewage sludge were compared. the effects of initial sulfuric acid addition on bioleaching process and influences of recycle rate of acidified bioleached sludge on subsequent bioleaching reaction were examined. the quantities of initial sulfuric acid addition ranged from 0 to 0.185 ml g(-1) dry slud ... | 2005 | 15881024 |
| genomic insights into the iron uptake mechanisms of the biomining microorganism acidithiobacillus ferrooxidans. | commercial bioleaching of copper and the biooxidation of gold is a cost-effective and environmentally friendly process for metal recovery. a partial genome sequence of the acidophilic, bioleaching bacterium acidithiobacillus ferrooxidans is available from two public sources. this information has been used to build preliminary models that describe how this microorganism confronts unusually high iron loads in the extremely acidic conditions (ph 2) found in natural environments and in bioleaching o ... | 2005 | 15895264 |
| identification of a gene cluster for the formation of extracellular polysaccharide precursors in the chemolithoautotroph acidithiobacillus ferrooxidans. | a cluster of five genes, proposed to be involved in the formation of extracellular polysaccharide (eps) precursors via the leloir pathway, have been identified in the acidophilic autotroph acidithiobacillus ferrooxidans. the order of the genes is luxa-gale-galk-pgm-galm, encoding a luxa-like protein, udp-glucose 4-epimerase, galactokinase, phosphoglucomutase, and galactose mutarotase, respectively. the gal cluster forms a single transcriptional unit and is therefore an operon. two other putative ... | 2005 | 15932984 |
| scanning force microscopy studies of the colonization and growth of a. ferrooxidans on the surface of pyrite minerals. | we have used the technique of scanning force microscopy (sfm) for studying the interaction of the bacteria a. ferrooxidans with the surface of the mineral pyrite. these bacteria are important to study with regard to acidification of streams and the environmental impact of such acidification. a. ferrooxidans cells readily colonize the pyrite surface, forming a tight mineral seal between the cell and the pyrite substrate. these bacteria subsequently may grow under ph neutral conditions, biooxidizi ... | 2005 | 15934505 |
| iron meteorites can support the growth of acidophilic chemolithoautotrophic microorganisms. | chemolithoautotrophy based on reduced inorganic minerals is considered a primitive energy transduction system. evidence that a high number of meteorites crashed into the planet during the early period of earth history led us to test the ability of iron-oxidizing bacteria to grow using iron meteorites as their source of energy. here we report the growth of two acidophilic iron-oxidizing bacteria, leptospirillum ferrooxidans and acidithiobacillus ferrooxidans, on a piece of the toluca meteorite as ... | 2005 | 15941383 |
| the ferric iron uptake regulator (fur) from the extreme acidophile acidithiobacillus ferrooxidans. | acidithiobacillus ferrooxidans is a gram-negative bacterium that lives at ph 2 in high concentrations of soluble ferrous and ferric iron, making it an interesting model for understanding the biological mechanisms of bacterial iron uptake and homeostasis in extremely acid conditions. a candidate fur(af) (ferric uptake regulator) gene was identified in the a. ferrooxidans atcc 23270 genome. fur(af) has significant sequence similarity, including conservation of functional motifs, to known fur ortho ... | 2005 | 15942007 |
| potential for using isotopically altered metalloproteins in species-specific isotope dilution analysis of proteins by hplc coupled to inductively coupled plasma mass spectrometry. | the production and evaluation of an isotopically enriched metalloprotein standard for use as a calibrant in species-specific isotope dilution analysis by hplc coupled to inductively coupled plasma mass spectrometry is described. using a model system involving the copper-containing protein rusticyanin (rc) from the bacterium acido-thiobacillus ferrooxidans, it was possible to demonstrate the analytical conditions that could be used for the measurement of metalloproteins by on-line idms analysis. ... | 2005 | 15987108 |
| bioleaching of metal from municipal waste incineration fly ash using a mixed culture of sulfur-oxidizing and iron-oxidizing bacteria. | we investigated the behavior and characteristics of metal leaching from municipal solid waste incineration (mswi) fly ash among pure cultures of a sulfur-oxidizing bacterium (sob) and an iron-oxidizing bacterium (iob) and a mixed culture. the iob has a high metal-leaching ability, though its tolerability against the ash addition is low. the sob might better tolerate an increase in ash addition than the iob, though metal leaching ability of the sob is limited. mixed culture could compensate for t ... | 2005 | 15993156 |
| electrochemistry of marmatite-carbon paste electrode in the presence of bacterial strains. | the electrochemical behaviors of a marmatite-carbon paste electrode with the chemical leaching of fe3+ ions, or the microbial leaching using acidithiobacillus ferrooxidans, were compared. the cyclic voltammograms of the electrode in the presence and absence of bacterial strains showed that the leaching process of marmatite was carried out by the different reactions occurring in the interface of the marmatite electrode-leach liquid. the polarization currents of the electrode under the differently ... | 2006 | 16000261 |
| identification of is elements in acidithiobacillus ferrooxidans strains grown in a medium with ferrous iron or adapted to elemental sulfur. | is elements were identified in the genomes of five acidithiobacillus ferrooxidans strains isolated from various media. ist2 elements were revealed in all the strains grown in a medium with ferrous iron, isafe1 elements were detected in four strains (tfbk, tfl-2, tfv-1 and tfo). three strains (tfv-1, tfn-d and tfo) were found to contain is elements, approximately 600 bp long. these were named preliminary as isafe600. partial sequencing of the 5'- and 3'-terminal nucleotide stretches of an isafe1 ... | 2005 | 16027952 |
| functional dissection of a mercuric ion transporter, merc, from acidithiobacillus ferrooxidans. | topological analysis with a phoa gene fusion suggested that acidithiobacillus ferrooxidans merc, a mercury transporter, has two periplasmic loops and four transmembrane domains. cys-23 and cys-26 of the protein were involved in hg(2+)-recognition/uptake, but cys-132 and cys-137 were not. escherichia coli cells producing the merc were hypersensitive to cdcl(2). in this case, mutation of his72 rendered the host cells less cdcl(2) sensitive, whereas none of the cys residues affected it. e. coli cel ... | 2005 | 16041147 |
| bioleaching of cadmium and nickel from synthetic sediments by acidithiobacillus ferrooxidans. | the microbial leaching process was evaluated for the treatment of synthetic sediments contaminated with cadmium and nickel sulfides. a series of batch leaching experiments was conducted to compare metal solubilization in sediment inoculated with acidithiobacillus ferrooxidans -inoculated sediments to that in sterile control sediment. the rate and extent of metal solubilization were significantly higher in a. ferrooxidans -inoculated reactors than in acidified sterile reactors. the efficiency of ... | 2005 | 16059779 |
| bacterial sensors based on acidithiobacillus ferrooxidans part ii. cr(vi) determination. | the aerobic acidophilic bacterium acidithiobacillus ferrooxidans oxidizes fe(2+) and s(2)o(3)(2-) ions by consuming oxygen. an amperometric biosensor was designed including an oxygen probe as transducer and a recognition element immobilized by a suitable home-made membrane. this biosensor was used for the indirect amperometric determination of cr(2)o(7)(2-) ions owing to methods based on a mediator (fe(2+)) or titration. using the mediator, the biosensor response versus cr(2)o(7)(2-) was linear ... | 2006 | 16084715 |
| bacterial sensors based on acidithiobacillus ferrooxidans part i. fe2+ and s2o32- determination. | an amperometric bacterial sensor with current response to fe(2+) and s(2)o(3)(2-) ions has been designed by immobilizing an acidophilic biomass of acidithiobacillus ferrooxidans on a multi disk flat-front oxygen probe. the bacterial layer was located between the oxygen probe and a membrane of cellulose. a filtration technique was used to yield the bacterial membranes having reproducible activity. the decrease of o(2) flow across the bacterial layer is proportional to the concentration of the dos ... | 2006 | 16095897 |
| ferroplasma and relatives, recently discovered cell wall-lacking archaea making a living in extremely acid, heavy metal-rich environments. | for several decades, the bacterium acidithiobacillus (previously thiobacillus) has been considered to be the principal acidophilic sulfur- and iron-oxidizing microbe inhabiting acidic environments rich in ores of iron and other heavy metals, responsible for the metal solubilization and leaching from such ores, and has become the paradigm of such microbes. however, during the last few years, new studies of a number of acidic environments, particularly mining waste waters, acidic pools, etc., in d ... | 2005 | 16104851 |
| analysis of differential protein expression in acidithiobacillus ferrooxidans grown under different energy resources respectively using seldi-proteinchip technologies. | surface-enhanced laser desorption/ionization (seldi)-time of flight is an affinity-based mass spectrometric method in which proteins of interest are selectively absorbed to a chemically modified surface on a chip, which allows proteomic analysis with limited material requirements. this characteristic makes it a valuable technique for microbiologists handling problematic samples, such as low cell number cultures. in this study, we explored differential-expressed proteome of acidithiobacillus ferr ... | 2006 | 16112213 |
| hybrid process for heavy metal removal from wastewater sludge. | bioleaching processes have been demonstrated to be effective technologies in removing heavy metals from wastewater sludge, but long hydraulic retention times are typically required to operate these bioprocesses. a hybrid process (coupling biological and chemical processes) has been explored in laboratory pilot-scale experiments for heavy metals (cadmium [cd], copper [cu], chromium [cr], and zinc [zn]) removal from three types of sludge (primary sludge, secondary activated sludge, and a mixture o ... | 2005 | 16121505 |
| an unusual tn21-like transposon containing an ars operon is present in highly arsenic-resistant strains of the biomining bacterium acidithiobacillus caldus. | a transposon, tnatcars, that carries a set of arsenic-resistance genes was isolated from a strain of the moderately thermophilic, sulfur-oxidizing, biomining bacterium acidithiobacillus caldus. this strain originated from a commercial plant used for the bio-oxidation of gold-bearing arsenopyrite concentrates. continuous selection for arsenic resistance over many years had made the bacterium resistant to high concentrations of arsenic. sequence analysis indicated that tnatcars is 12 444 bp in len ... | 2005 | 16151213 |
| volume of extracellular polymeric substance coverage of individual acidithiobacillus ferrooxidans bacterium measured by atomic force microscopy. | the acidithiobacillus ferrooxidans response to stress associated with the drying process is known to be the production of extracellular polymeric substance (eps) coverage. here, samples of a. ferrooxidans suspensions grown in 1.8 ph and 3.0 ph and dried on mica and silicon are shown to form a structure of isolated bacteria. individual bacteria coverage patterns were imaged by atomic force microscopy (afm) on hydrophobic (silicon) and hydrophilic (mica) substrates. a comparison of images of cover ... | 2005 | 16173093 |
| analysis of differential-expressed proteins of acidithiobacillus ferrooxidans grown under phosphate starvation. | acidithiobacillus ferrooxidans is one of the most important bacterium used in bioleaching, and can utilize fe(2+) or sulphide as energy source. growth curves for acidithiobacillus ferrooxidans under phosphate starvation and normal condition have been tested, showing lag, logarithmic, stationary and aging phases as seen in other bacteria. the logarithmic phases were from 10 to 32 hours for acidithiobacillus ferrooxidans cultivated with normal cultivating condition and from 20 to 60 hrs for acidit ... | 2005 | 16202233 |
| diversity and functional analysis of bacterial communities associated with natural hydrocarbon seeps in acidic soils at rainbow springs, yellowstone national park. | in this paper we describe the bacterial communities associated with natural hydrocarbon seeps in nonthermal soils at rainbow springs, yellowstone national park. soil chemical analysis revealed high sulfate concentrations and low ph values (ph 2.8 to 3.8), which are characteristic of acid-sulfate geothermal activity. the hydrocarbon composition of the seep soils consisted almost entirely of saturated, acyclic alkanes (e.g., n-alkanes with chain lengths of c15 to c30, as well as branched alkanes, ... | 2005 | 16204508 |
| [determination of minimal concentrations of biocorrosion inhibitors by a bioluminescence method in relation to bacteria, participating in biocorrosion]. | by using a bioluminescence atp assay, we have determined the minimal concentrations of some biocorrosion inhibitors (katon, khazar, vfiks-82, nitro-1, kaspii-2, and kaspii-4) suppressing most common microbial corrosion agents: desulfovibrio desulfuricans, desulfovibrio vulgaris, pseudomonas putida, pseudomonas fluorescens, and acidithiobacillus ferrooxidans. the cell titers determined by the bioluminescence method, including not only dividing cells but also their dormant living counterparts, are ... | 2005 | 16212040 |
| laboratory scale bioremediation of acid mine water drainage from a disused tin mine. | real acidic mine-water drainage was seeded with acidithiobacillus ferrooxidans to catalyse the removal of iron contained therein. the addition of at. ferrooxidans increased metal precipitation kinetics and decreased the water iron content by approximately 70%. supplementing non-sterile mine water with a bacterial growth medium accelerated metal removal by indigenous micro-organisms both at the 500 ml shake-flask and 5 l bioreactor scale. | 2005 | 16215821 |
| the passivation of pyrrhotite by surface coating. | the potential of triethylenetetramine (teta) to inhibit the oxidation of three pyrrhotites, garson, mccreedy and po-97 has been studied systematically and confirmed by comparing the release of fe and so4(2-) from samples with and without coating treatment. each sample, original or coated by teta, was exposed to oxygen, 1 x 10(-3) m fecl3, and acidithiobacillus ferrooxidans, respectively, for specific oxidation periods. both abiotic and biotic oxidation of samples treated by this passivating agen ... | 2005 | 16219502 |
| the role of higher polythionates in the reduction of chromium(vi) by acidithiobacillus and thiobacillus cultures. | in this paper, we report the chromium(vi) reduction by filtrates of acidithiobacillus and thiobacillus cultures. chromium(vi) reduction by filtrates of a. ferrooxidans cultures under acidic conditions was higher than that observed for a. thiooxidans. however, at ph close to 7, chromium(vi) reduction by filtrates of t. thioparus cultures was as high as that by filtrates of a. thiooxidans cultures and much higher than that observed for a. ferrooxidans cultures at the same ph. the capability of the ... | 2006 | 16223540 |
| acidithiobacillus ferrooxidans fixation on mercuric surfaces and its application in stripping voltammetry. | the adsorption (fixation) of bacteria acidithiobacillus ferrooxidans on hg and cu metallic surfaces was qualitatively studied owing to two independent methods: frequency measurement using a quartz crystal microbalance and light absorption measuring at the hg/bacterial culture interface. a method using a dropping mercury electrode (dme) allowed quantifying this bacterial fixation. determining the superficial tension at hg/bacterial culture interface led to determine bacteria adsorption on hg thro ... | 2006 | 16223579 |
| cytochrome c oxidase purified from a mercury-resistant strain of acidithiobacillus ferrooxidans volatilizes mercury. | we suggested in our previous study that the plasma membrane cytochrome c oxidase of the mercury-resistant iron-oxidizing bacterial strain acidithiobacillus ferrooxidans, sug 202, is involved in fe2+-dependent mercury volatilization. to study the involvement of a. ferrooxidans cytochrome c oxidase in mercury reduction, the cytochrome c oxidase was extracted from mercury-resistant and mercury-sensitive strains and purified. the fe2+-dependent mercury volatilization activities of the oxidases from ... | 2001 | 16233056 |
| volatilization and recovery of mercury from mercury wastewater produced in the course of laboratory work using acidithiobacillus ferrooxidans sug 2-2 cells. | the iron-oxidizing bacterium acidithiobacillus ferrooxidans sug 2-2 is markedly resistant to mercuric chloride and can volatilize mercury (hg0) from mercuric ion (hg2+) under acidic conditions. to develop a microbial technique to volatilize and recover mercury from acidic and organic compound-containing mercury wastewater, which is usually produced in the course of everyday laboratory work in okayama university, the effects of organic and inorganic chemicals on the mercury volatilization activit ... | 2003 | 16233399 |
| kinetic rate constant for electron transfer between ferrous ions and novel rusticyanin isoform in acidithiobacillus ferrooxidans. | here we report the kinetic rate constant for electron transfer from ferrous ions to a novel rusticyanin isoform in acidithiobacillus ferrooxidans. the second order rate constant for this isoform is shown to be approximately one half that of the previously known type, 0.09 m(-1)s(-1) vs. 0.14 m(-1)s(-1). | 2003 | 16233452 |
| inhibitory effect of high concentrations of ferric ions on the activity of acidithiobacillus ferrooxidans. | the influence of high concentrations of ferric ions on the biochemical activity of acidithiobacillus ferrooxidans was studied using intact cells. the specific oxidation rate of ferrous ions decreased with increasing ferric ion concentration. lineweaver-burk plots revealed typical competitive inhibition kinetics, because the slopes varied with the ferric ion concentration. a linear relationship between the slope and the square of the ferric ion concentration revealed that the iron-oxidizing enzym ... | 2003 | 16233540 |
| existence of a tungsten-binding protein in acidithiobacillus ferrooxidans ap19-3. | a tungsten-binding protein was purified from a plasma membrane preparation of the iron-oxidizing bacterium, acidithiobacillus ferrooxidans ap19-3 in an electrophoretically homogenous state. the protein was composed of two subunits with apparent molecular masses of 12 and 20.7 kda. the molecular mass of the native protein was estimated to be 26.4 kda in the presence of 1.5% 1-o-octyl-d -glucopyranoside (ogl), indicating that the native tungsten-binding protein is a heterodimeric protein. the amou ... | 2004 | 16233646 |
| suppression of arsenopyrite surface oxidation by sol-gel coatings. | oxidation of arsenopyrite (feass) in mine tailings is considered as the major cause of arsenic release in groundwater around mineral mine sites. oxidation rate is increased by the biooxidation of chemolithoautotrophic bacteria, such as acidithiobacillus ferrooxidans via the adsorption mechanism. hence, coating with thin films as a physical barrier for oxidants surrounding the mineral surface is one of the effective abatement strategies. in this work, we studied and characterized the formation of ... | 2005 | 16233789 |
| existence of an iron-oxidizing bacterium acidithiobacillus ferrooxidans resistant to organomercurial compounds. | acidithiobacillus ferrooxidans mon-1 which is highly resistant to hg2+ could grow in a ferrous sulfate medium (ph 2.5) with 0.1 microm p-chloromercuribenzoic acid (pcmb) with a lag time of 2 d. in contrast, a. ferrooxidans ap19-3 which is sensitive to hg2+ did not grow in the medium. nine strains of a. ferrooxidans, including seven strains of the american type culture collection grew in the medium with a lag time ranging from 5 to 12 d. the resting cells of mon-1, which has nadph-dependent mercu ... | 2005 | 16233835 |
| simultaneous removal of h2s and nh3 in biofilter inoculated with acidithiobacillus thiooxidans tas. | h2s and nh3 gases are toxic, corrosive and malodorous air pollutants. although there are numerous well-established physicochemical techniques presently available for the treatment of these gases, the growing demand for a more economical and improved process has prompted investigations into biological alternatives. in biological treatment methods, h2s is oxidized to so4(2-) by sulfur-oxidizing bacteria, and then nh3 is removed by chemical neutralization with so4(2-) to (nh4)2so4. since the accumu ... | 2005 | 16233839 |
| a simple procedure for elimination of fungal contamination for enumeration of iron-oxidizing bacteria from bioleaching matrix of sewage sludge. | enumeration of iron-oxidizing bacteria from the bioleaching matrix of sewage sludge is always confronted by fungal contamination. the objective of the present study was to find a reliable and simple method to remove fungal growth and to shorten the incubation time for facilitating enumeration of the iron-oxidizers from complex sludge samples. the results demonstrated that filtering the sludge sample through sterile no. 5 whatman filter paper before serial dilution was effective in eliminating th ... | 2005 | 16234862 |
| effects of electron transport inhibitors and uncouplers on the oxidation of ferrous iron and compounds interacting with ferric iron in acidithiobacillus ferrooxidans. | oxidation of fe2+, ascorbic acid, propyl gallate, tiron, l-cysteine, and glutathione by acidithiobacillus ferrooxidans was studied with respect to the effect of electron transport inhibitors and uncouplers on the rate of oxidation. all the oxidations were sensitive to inhibitors of cytochrome c oxidase, kcn, and nan3. they were also partially inhibited by inhibitors of complex i and complex iii of the electron transport system. uncouplers at low concentrations stimulated the oxidation and inhibi ... | 2005 | 16234867 |
| a lux-like quorum sensing system in the extreme acidophile acidithiobacillus ferrooxidans. | the genome of the acidophilic, proteobacterium acidithiobacillusferrooxidans, contains linked but divergently oriented genes, termed afel and afer, whose predicted protein products are significantly similar to the luxi and luxr families of proteins. a possible promoter and lux box are predicted upstream of afel. a cloned copy of afel, expressed in e. coli, encodes an enzyme that catalyzes the production of a diffusible compound identified by gas chromatography and mass spectrometry as an unsubst ... | 2005 | 16238107 |
| purification and biochemical characterization of the f1-atpase from acidithiobacillus ferrooxidans nasf-1 and analysis of the atp operon. | atpase was purified 51-fold from a chemoautotrophic, obligately acidophilic iron-oxidizing bacterium, acidithiobacillus ferrooxidans nasf-1. the purified atpase showed the typical subunit pattern of the f1-atpase on a polyacrylamide gel containing sodium dodecyl sulfate, with 5 subunits of apparent molecular masses of 55, 50, 33, 20, and 18 kda. the enzyme hydrolyzed atp, gtp, and itp, but neither utp nor adp. the k(m) value for atp was 1.8 mm. atpase activity was optimum at ph 8.5 at 45 degrees ... | 2005 | 16244438 |
| bioleaching of sulfidic tailing samples with a novel, vacuum-positive pressure driven bioreactor. | this study presents a design for a novel bioreactor that uses alternating vacuum and positive pressure cycles to transfer acidic leach solution in and out of contact with finely ground sulfidic mine tailings. these tailings constitute an environmental problem that needs experimental data to support the development of management and control strategies. a conventional stirred tank bioreactor was used as a reference system. both bioreactors were inoculated with mixed cultures of acidophilic iron an ... | 2005 | 16245345 |
| [molecular diversity of the gene encoding fe(ii)-oxidizing enzyme in acidithiobacillus ferrooxidans]. | acidithiobacillus ferrooxidans (a.f) is a gram-negative chemolithotrophic bacterium able to oxidize ferrous iron, elemental sulfur and inorganic sulfur compounds. fe(ii)-oxidizing enzyme plays key role in fe(ii)-oxidizing system. different a.f strains, which were isolated and purified from various ecological niches, show obviously phenotypic diversity after comparison rates of growth and oxidation of fe2+. the fe(ii)-oxidizing enzyme gene(iro) for five strains was identified by pcr reactions uit ... | 2005 | 16257910 |
| evidence for a functional quorum-sensing type ai-1 system in the extremophilic bacterium acidithiobacillus ferrooxidans. | acidithiobacillus ferrooxidans is one of the main acidophilic chemolithotrophic bacteria involved in the bioleaching of metal sulfide ores. the bacterium-mineral interaction requires the development of biofilms, whose formation is regulated in many microorganisms by type ai-1 quorum sensing. here, we report the existence and characterization of a functional type ai-1 quorum-sensing system in a. ferrooxidans. this microorganism produced mainly acyl-homoserine lactones (ahl) with medium and large ... | 2005 | 16269739 |
| a trna(glu) that uncouples protein and tetrapyrrole biosynthesis. | glu-trna is either bound to elongation factor tu to enter protein synthesis or is reduced by glutamyl-trna reductase (glutr) in the first step of tetrapyrrole biosynthesis in most bacteria, archaea and in chloroplasts. acidithiobacillus ferrooxidans, a bacterium that synthesizes a vast amount of heme, contains three genes encoding trna(glu). all trna(glu) species are substrates in vitro of glurs1 from a. ferrooxidans.glu-trna(3)(glu), that fulfills the requirements for protein synthesis, is not ... | 2005 | 16271718 |
| [expression of phosphofructokinase gene from escherichia coli k-12 in obligately autotrophic bacterium acidithiobacillus thiooxidans]. | a plasmid psdk-1 containing the escherichia coli phosphofructokinase-1 (ec 2.7.1. 11) gene (pfka) was constructed and transferred into acidithiobacillus thiooxidans tt-z2 by conjugation. the transfer frequency of plasmid from e. coli to tt-z2 was 2.6 x 10(-6). more than 68% of tt-z2 cells carried the recombinant plasmids after being cultured for 50 generations without selective pressure, which showed that psdk-1 was maintained consistently in tt-z2. the pfka gene from e. coli could be expressed ... | 2003 | 16281556 |
| growth inhibition by tungsten in the sulfur-oxidizing bacterium acidithiobacillus thiooxidans. | growth of five strains of sulfur-oxidizing bacteria acidithiobacillus thiooxidans, including strain nb1-3, was inhibited completely by 50 microm of sodium tungstate (na(2)wo(4)). when the cells of nb1-3 were incubated in 0.1 m beta-alanine-so(4)(2-) buffer (ph 3.0) with 100 microm na(2)wo(4) for 1 h, the amount of tungsten bound to the cells was 33 microg/mg protein. approximately 10 times more tungsten was bound to the cells at ph 3.0 than at ph 7.0. the tungsten binding to nb1-3 cells was inhi ... | 2005 | 16306687 |
| [dependence of the genotypic characteristics of acidithiobacillus ferrooxidans on the physical, chemical, and electrophysical properties of pyrites]. | comparison of acidithiobacillus ferrooxidans strains tfv-1 and tfbk with respect to their capacity to oxidize pyrite 1, with hole-type (p-type) conductivity, or pyrite 2, with an electron-type (n-type) conductivity, showed that, at a pulp density of 1%, both before and after its adaptation to the pyrites, strain tfbk, isolated from a substrate with a more complex mineral composition, grew faster and oxidized the pyrites of both conductivity types more efficiently than strain tfv-1, which was iso ... | 2005 | 16315977 |
| [dependence of the genotypic characteristics of acidithiobacillus ferrooxidans on the physical, chemical, and electrophysical properties of pyrites]. | this study focused on the effect of physical, chemical, and electrophysical properties of two pyrites, pyrite 1, which had hole-type (p-type) conductivity, and pyrite 2, with electron-type (n-type) conductivity, on the genotypic characteristics of acidithiobacillus ferrooxidans strains tfv-1 and tfbk, which were isolated from different substrates. after the adaptation of the strains to the pyrites at a pulp density of 1%, pulsed-field electrophoresis revealed changes in the chromosomal dna of st ... | 2005 | 16315978 |
| [construction of an engineered acidithiobacillus caldus with high-efficiency arsenic resistance]. | using the recombinant technique in vitro, a new arsenic resistance plasmid psdra4 was constructed by subcloning the arsenic resistance genes from plasmid pum3 into the wide-host-range incq plasmid pmmb24 with the hybrid trp-lac ( tac ) promoter, and followed by deleting the regulative gene of the promoter, the laciq gene. then plasmid psdra4 was introduced from e. coli into extremely acidophilic obligately chemolithotrophic acidithiobacillus caldus by conjugative transfer with a frequency of( 1. ... | 2005 | 16342754 |
| assessment of the microbial community in a constructed wetland that receives acid coal mine drainage. | constructed wetlands are used to treat acid drainage from surface or underground coal mines. however, little is known about the microbial communities in the receiving wetland cells. the purpose of this work was to characterize the microbial population present in a wetland that was receiving acid coal mine drainage (amd). samples were collected from the oxic sediment zone of a constructed wetland cell in southeastern ohio that was treating acid drainage from an underground coal mine seep. samples ... | 2006 | 16400536 |
| effect of anaerobic digestion and initial ph on metal bioleaching from sewage sludge. | the effects of anaerobic digestion and initial ph on the bioleaching of metals from sewage sludge were investigated in shake flask experiments. a strain of acidithiobacillus thiooxidans was employed in the assays using secondary and anaerobic sludges, which resulted in similar solubilization yields of the metals chromium, copper, lead, nickel, and zinc for both the sludges investigated. the effect of initial ph (7.0 and 4.0) on metal bioleaching was assayed by using the anaerobic sludge inoculat ... | 2006 | 16423726 |
| extracellular polymeric substances mediate bioleaching/biocorrosion via interfacial processes involving iron(iii) ions and acidophilic bacteria. | extracellular polymeric substances seem to play a pivotal role in biocorrosion of metals and bioleaching, biocorrosion of metal sulfides for the winning of precious metals as well as acid rock drainage. for better control of both processes, the structure and function of extracellular polymeric substances of corrosion-causing or leaching bacteria are of crucial importance. our research focused on the extremophilic bacteria acidithiobacillus ferrooxidans and leptospirillum ferrooxidans, because of ... | 2006 | 16431087 |
| recovery of scrap iron metal value using biogenerated ferric iron. | the utility of employing biogenerated ferric iron as an oxidant for the recycling of scrap metal has been demonstrated using continuously growing cells of the extremophilic organism acidithiobacillus ferrooxidans. a ferric iron rich (70 mol%) lixiviant resulting from bioreactor based growth of a. ferrooxidans readily solubilized target scrap metal with the resultant generation of a leachate containing elevated ferrous iron levels and solubilized copper previously resident in the scrap metal. rec ... | 2006 | 16440341 |
| [bioleaching of fly ash from municipal solid waste incinerator using sewage sludge and pig manure as culture media]. | a mixed culture of acidihiobacillus ferrooaidans and acidihiobacillus thiooxidans was used to leach heavy metals from municipal solid waste incineration fly ash (mswi fly ash). this study explored the possibility of using sewage sludge or pig manure as nutrients for supporting the growth of the leaching bacteria and allowing metal solubilization like a synthetic mineral medium. in contrast to pig manure, there is a high ability for acidification of the fly ash and solubilization of toxic metals ... | 2005 | 16447455 |
| diversity of 16s ribosomal dna-defined bacterial population in acid rock drainage from japanese pyrite mine. | four acidophilic bacteria (yards1-4) were isolated from an acid rock drainage (ard) from yanahara mine, okayama prefecture, japan. the physiological and 16s rdna sequence analyses revealed that yard1 was closely affiliated with acidithiobacillus ferrooxidans, yard2 was an acidiphilium-like bacterium, and yard3 and yard4 were sulfur-oxidizing bacteria with a relatively close relationship to a. ferrooxidans in the phylogenetic analysis. a molecular approach based on the construction of a 16s rdna ... | 2005 | 16473774 |
| phospholipids from the chemoautotroph ferrobacillus ferrooxidans. | | 1967 | 16496519 |
| autotrophic growth of acidithiobacillus ferrooxidans by oxidation of molecular hydrogen using a gas-liquid contactor. | the iron-oxidizing bacterium, acidithiobacillus ferrooxidans, was cultivated on a medium without ferrous iron. molecular hydrogen and air were supplied to the medium. it was found that a. ferrooxidans could grow with hydrogen in the ph range between 2.0 and 3.5. a trickle-bed contactor was used to increase the dissolution rate of hydrogen. the doubling time was increased and the cell concentration reached 4.0 x 10(9) cells ml(-1) after 6 days. when the cells taken from the hydrogen medium were t ... | 2007 | 16500099 |
| rapid specific detection and quantification of bacteria and archaea involved in mineral sulfide bioleaching using real-time pcr. | a sybrgreen real-time pcr assay was developed to detect and quantify both total and selected 16s rdna species of bacteria and archaea involved in the bioleaching of metals from sulfide ores. a set of specific and universal primers based on 16s rdna sequences was designed and validated for specific detection and quantification of dna isolated from representative strains of acidianus brierleyi, sulfolobus sp., sulfobacillus thermosulfidooxidans, sulfobacillus acidophilus, acidithiobacillus caldus, ... | 2006 | 16508994 |
| resistance determinants of a highly arsenic-resistant strain of leptospirillum ferriphilum isolated from a commercial biooxidation tank. | two sets of arsenic resistance genes were isolated from the highly arsenic-resistant leptospirillum ferriphilum fairview strain. one set is located on a transposon, tnlfars, and is related to the previously identified tnatcars from acidithiobacillus caldus isolated from the same arsenopyrite biooxidation tank as l. ferriphilum. tnlfars conferred resistance to arsenite and arsenate and was transpositionally active in escherichia coli. tnlfars and tnatcars were sufficiently different for them not ... | 2006 | 16517682 |
| mobilisation of arsenic from a mining soil in batch slurry experiments under bio-oxidative conditions. | laboratory investigations were performed to estimate the potential mobility of arsenic (as) from a highly contaminated gold-mining soil under bio-oxidative aerobic conditions as a potential remediation process. the selected soil was sampled from a gold-mining site in the south of france. it contained 27700 mg kg(-1) total as, with only 0.01% present under water-soluble forms. the nature of the immobilization mechanisms was identified by using complementary physical and chemical techniques. as wa ... | 2006 | 16529789 |
| structure analysis of 16s rdna sequences from strains of acidithiobacillus ferrooxidans. | four strains of acidithiobacillus ferrooxidans with different iron oxidation capacity were isolated from different mine drainage stations. the 16s rrna gene of these strains were cloned and sequenced. based on our sequences analysis on the four strain and the data on the other strains deposited in genbank, all a. ferrooxidans may be classified into three phylogenetic groups. the analysis data showed that nucleotide variables (signature sites) were detected in 21 positions, and most of them were ... | 2006 | 16584633 |
| structural analysis of the hipip from the acidophilic bacteria: acidithiobacillus ferrooxidans. | hip is a high-potential iron-sulfur protein (hipip) isolated from the acidophilic bacterium, acidithiobacillus ferrooxidans. in the present work, a structural model of hip suggests that the role of proline residues is essential to stabilize the protein folding at very low ph. the presence of an unusual disulfide bridge in hip is demonstrated using mass spectrometry and nuclear magnetic resonance. this disulfide bridge is necessary to anchor the n-terminal extremity of the protein, but is not inv ... | 2006 | 16604275 |
| acidophilic microbial communities catalyzing sludge bioleaching monitored by fluorescent in situ hybridization. | biological autotrophic sulfur oxidation processes have been proposed to remove heavy metals from wastewater treatment sludge by bioleaching. we made a characterization of the microbial population in batch and continuous sludge bioleaching reactors using fluorescent in situ hybridization of fluorescently-labeled oligonucleotidic probes targeting rrna in a 'top to bottom approach'. batch incubations of sludge with 0.2% (w/v) elemental sulfur resulted in a ph value of 5. alpha-proteobacteria hybrid ... | 2006 | 16622787 |
| evaluation of in situ layers for treatment of acid mine drainage: a field comparison. | reactive treatment layers, containing labile organic carbon, were evaluated to determine their ability to promote sulfate reduction and metal sulfide precipitation within a tailings impoundment, thereby treating tailings effluent prior to discharge. organic carbon materials, including woodchips and pulp waste, were mixed with the upper meter of tailings in two separate test cells, a third control cell contained only tailings. in the woodchip cell sulfate reduction rates were 500 mg l-1a-1, (5.2 ... | 2006 | 16626781 |
| electron transport pathways for the oxidation of endogenous substrate(s) in acidithiobacillus ferrooxidans. | oxidation of endogenous substrate(s) of acidithiobacillus ferrooxidans with o2 or fe3+ as electron acceptor was studied in the presence of uncouplers and electron transport inhibitors. endogenous substrate was oxidized with a respiratory quotient (co2 produced/o2 consumed) of 1.0, indicating its carbohydrate nature. the oxidation was inhibited by complex i inhibitors (rotenone, amytal, and piericidin a) only partially, but piericidin a inhibited the oxidation with fe3+ nearly completely. the oxi ... | 2006 | 16699582 |
| removal of hydrogen sulfide by sulfate-resistant acidithiobacillus thiooxidans az11. | toxic h2s gas is an important industrial pollutant that is applied to biofiltration. here, we examined the effects of factors such as inlet concentration and space velocity on the removal efficiency of a bacterial strain capable of tolerating high sulfate concentrations and low ph conditions. we examined three strains of acidithiobacillus thiooxidans known to have sulfur-oxidizing activity, and identified strain az11 as having the highest tolerance for sulfate. a. thiooxidans az11 could grow at ... | 2006 | 16716938 |
| proteomic and bioinformatic analysis of iron- and sulfur-oxidizing acidithiobacillus ferrooxidans using immobilized ph gradients and mass spectrometry. | a comparative analysis of the protein composition of acidithiobacillus ferrooxidans cells grown on elemental sulfur and ferrous iron was performed. a newly developed protocol involving immobilized ph gradients, improved protein reduction, mass spectrometry protein identification and full genome sequence information was applied. this approach resulted in more than 1300 protein spots displayed in broad and basic ph ranges, the best a. ferrooxidans proteome resolution to date. a comparative image a ... | 2006 | 16807941 |
| agronomic effectiveness of biofertilizers with phosphate rock, sulphur and acidithiobacillus for yam bean grown on a brazilian tableland acidic soil. | phosphate rocks have low available p and soluble p fertilizers have been preferably used in plant crop production, although economic and effective p sources are needed. experiments were carried out on a brazilian typic fragiudult soil with low available p to evaluate the agronomic effectiveness of phosphate rock (pr) compared with soluble phosphate fertilizer. yam bean (pachyrhizus erosus) inoculated with rhizobia (strains nfb 747 and nfb 748) or not inoculated was the test crop. biofertilizers ... | 2007 | 16815009 |
| microbial populations identified by fluorescence in situ hybridization in a constructed wetland treating acid coal mine drainage. | microorganisms are an integral part of the biogeochemical processes in wetlands, yet microbial communities in sediments within constructed wetlands receiving acid mine drainage (amd) are only poorly understood. the purpose of this study was to characterize the microbial diversity and abundance in a wetland receiving amd using fluorescence in situ hybridization (fish) analysis. seasonal samples of oxic surface sediments, comprised of fe(iii) precipitates, were collected from two treatment cells o ... | 2006 | 16825452 |
| generation of mercury-hyperaccumulating plants through transgenic expression of the bacterial mercury membrane transport protein merc. | the merc gene from acidithiobacillus ferrooxidans functions as a mercury uptake pump. merc protein localizes in the cytoplasmic membrane of plant cells. when arabidopsis thaliana and tobacco plants were transformed with the merc gene under the control of the cauliflower mosaic virus 35s promoter, the resulting overexpression of merc rendered the host plants hypersensitive to hg2+ and they accumulated approximately twice as much hg2+ ion as the wild type plants. thus, bacterial mercuric ion trans ... | 2006 | 16830224 |
| existence of aa3-type ubiquinol oxidase as a terminal oxidase in sulfite oxidation of acidithiobacillus thiooxidans. | it was found that acidithiobacillus thiooxidans has sulfite:ubiquinone oxidoreductase and ubiquinol oxidase activities in the cells. ubiquinol oxidase was purified from plasma membranes of strain nb1-3 in a nearly homogeneous state. a purified enzyme showed absorption peaks at 419 and 595 nm in the oxidized form and at 442 and 605 nm in the reduced form. pyridine ferrohaemochrome prepared from the enzyme showed an alpha-peak characteristic of haem a at 587 nm, indicating that the enzyme contains ... | 2006 | 16861791 |
| the effect of adsorbed lipid on pyrite oxidation under biotic conditions. | the chemolithoautotrophic bacterium, acidithiobacillus ferrooxidans, commonly occurs in acid mine drainage (amd) environments where it is responsible for catalyzing the oxidation of pyrite and concomitant development of acidic conditions. this investigation reports on the growth of this bacterial species on the pyrite surface and in the aqueous phase at a ph close to 2 as well as the role of adsorbed lipid in preventing pyrite dissolution. both acid washed pyrite and acid-washed pyrite coated wi ... | 2006 | 16869974 |
| [bacterial leaching of manganese ores]. | leaching of various types of ores, containing 12-30% manganese, by the thiobacterium acidithiobacillus ferrooxidans was studied. leaching of reduced ores (manganocalcite and manganiferous limestone) was mediated mainly by degradation of manganiferous minerals (by sulfuric acid produced in the course of bacterial oxidation of pyrite or sulfur). bacterial treatment of the ores for 144 and 192 h allowed solubilization of 96-98% of manganese. inoculation of bacteria into pulp with pyrite increased t ... | 2006 | 16878550 |
| [effect of temperature on bioleaching of cr from tannery sludge]. | bioleaching processes are normally sensitive to temperature fluctuations. shake flask experiments were conducted to examine these effects in the temperature range of 12-36 degrees c. the results showed that there was an increase in the rates of ph reduction and cr solubilization efficiency with the increase of the temperature of bioleaching reaction. after 8 days of bacterial leaching treatment, almost 100% of cr could be leached from tannery sludge at the temperature of 28 degrees c and 36 degr ... | 2006 | 16881329 |
| [adsorption and coprecipitation of dissolved metals with jarosite under conditions simulating sewage sludge bioleaching]. | the inoculation of acidithiobacillus ferrooxidans and the addition of fe2+ as their substrates accelerated the solubilization of zn, cu and cr from sewage sludge. however, a decrease in cu removal from 91% to 60% with time elapse could be observed in the late process, which appeared simultaneously with the formation of jarosite resulting from hydrolysis of fe3+. the tested jarosite was synthesized by using bacterial oxidation of fe2+ by resting a. ferrooxidans in acid solution (ph 2.5) under con ... | 2006 | 16883881 |
| biomodification of coal to remove mercury. | a biological process for removal of mercury from coal is under investigation. iron and sulfur oxidizing bacteria have previously been used for desulfurization of coal and for mineral mining. we have shown that removal of mercury from coal is also possible via the same principles. two pure cultures, leptospirillum ferrooxidans and acidithiobacillus ferrooxidans and four environmental consortium samples obtained from an acid mine drainage site were studied for mercury removal from coal. four diffe ... | 2006 | 16915698 |
| [study on immobilization of acidithiobacillus ferrooxidans using pva-ca(no3)2 method]. | a new cell immobilization technique utilizing the complex of pva solution and sodium alginate solution as entrapment medium is reported. the mixture of acidithiobacillus ferrooxidans suspension and the entrapment complex were extruded into the solution of ca(no3)2 (1% - 5%) to form beads, then the beads were frozen at -20 degrees c for 1d and thawed at room temperature. this method can simultaneously eliminate the agglomeration of pva beads and the biological toxicity of h3 bo31. a maximum oxida ... | 2006 | 16933620 |
| biological oxidation of metallic copper by acidithiobacillus ferrooxidans. | this is a report on the kinetic aspects and the analytical study of the bioproducts of the oxidation of zero-valence copper by immobilized acidithiobacillus ferrooxidans. two different mechanisms of oxidation were considered: direct and indirect. a custom-built bioreactor was used to grow a. ferrooxidans in an iron-free media, which was required for the study of the direct mechanism. x-ray microdiffraction analysis of the copper after biooxidation in the sulfate-free medium revealed the presence ... | 2007 | 16937398 |
| influence of initial ph on bioleaching of heavy metals from contaminated soil employing indigenous acidithiobacillus thiooxidans. | bioleaching of heavy metals from contaminated soil was carried out employing indigenous sulfur oxidizing bacterium acidithiobacillus thiooxidans. experiments were carried out to assess the influence of initial ph of the system on bioleaching of chromium, zinc, copper, lead and cadmium from metal contaminated soil. ph at the end of four weeks of bioleaching at different initial ph of 3-7 was between 0.9 and 1.3, orp between 567 and 617mv and sulfate production was in the range of 6090-8418mgl(-1) ... | 2007 | 16979697 |
| high-rate ferrous iron oxidation by immobilized acidithiobacillus ferrooxidans with complex of pva and sodium alginate. | by four different methods, acidithiobacillus ferrooxidans cells were immobilized by the complex of pva and sodium alginate. the beads formed by these different methods were evaluated in terms of relative mechanical strength, biological activity, dilatability, and so on. the results indicate that the technique utilizing the complex of pva and sodium alginate crosslinked with ca(no(3))(2) is more appropriate for the immobilization of a. ferrooxidans than any others. so the pva-calcium nitrate bead ... | 2007 | 16979768 |
| diversity of culturable halophilic sulfur-oxidizing bacteria in hypersaline habitats. | unexpectedly high culturable diversity of moderately and extremely halophilic obligately chemolithoautotrophic sulfur-oxidizing bacteria (sob) was discovered in the sediments of various hypersaline habitats, including chloride-sulfate lakes in mongolia, russia and ukraine, a sea saltern in slovenia and a deep-sea salt brine from the mediterranean. six different groups of halophilic sob, including four new genera, all belonging to the gammaproteobacteria, were found. two groups of moderately halo ... | 2006 | 17005982 |
| inhibitory effects of sulfamic acid on three thiosulfate-oxidizing chemolithotrophs. | sulfamate is an analogue of thiosulfate, and the sodium and potassium salts of sulfamic acid inhibited the chemolithoautotrophic growth on thiosulfate of acidithiobacillus ferrooxidans and halothiobacillus neapolitanus. the chemo-organotrophic growth of paracoccus versutus on sucrose was similarly inhibited by sulfamate. thiosulfate oxidation by suspensions of h. neapolitanus was, however, unaffected by sulfamate, showing that sulfamate did not directly affect thiosulfate uptake, activation or o ... | 2006 | 17020550 |
| extracellular polymeric bacterial coverages as minimal area surfaces. | surfaces formed by extracellular polymeric substances enclosing individual and some small communities of acidithiobacillus ferrooxidans on plates of hydrophobic silicon and hydrophilic mica are analyzed by means of atomic force microscopy imaging. accurate nanoscale descriptions of such coverage surfaces are obtained. the good agreement with the predictions of a rather simple but realistic theoretical model allows us to conclude that they correspond, indeed, to minimal area (constant mean curvat ... | 2006 | 17045281 |
| pilot-plant study of wastewater sludge decontamination using a ferrous sulfate bioleaching process. | the objective of this research was to investigate the performance of the ferrous sulfate bioleaching (fsbl) process in a pilot plant for decontamination and stabilization of wastewater sludge. batch and continuous experiments, conducted with two 4-m3 bioreactors using indigenous iron-oxidizing bacteria (20% v/v of inoculum) with addition of 4.0 g ferrous sulfate heptahydrate per liter of sludge initially acidified to ph 4.0, were sufficient for effective heavy metal (cadmium, copper, manganese, ... | 2006 | 17059142 |
| cultivation-dependent and cultivation-independent characterization of the microbial community in acid mine drainage associated with acidic pb/zn mine tailings at lechang, guangdong, china. | cultivation-based and molecular approaches were used to characterize the phylogenetic composition and structure of the microbial community in an extremely acidic (ph 2.0) acid mine drainage (amd) associated with pb/zn mine tailings that were undergoing vigorous acid generation. acidophilic bacteria were isolated and enumerated on solid media, and were found to be restricted to isolates related to acidithiobacillus ferrooxidans and acidiphilium cryptum. by contrast, cloning and phylogenetic analy ... | 2007 | 17059483 |
| characterization of a cyanobacterial-like uptake [nife] hydrogenase: epr and ftir spectroscopic studies of the enzyme from acidithiobacillus ferrooxidans. | electron paramagnetic resonance (epr) and fourier transform ir studies on the soluble hydrogenase from acidithiobacillus ferrooxidans are presented. in addition, detailed sequence analyses of the two subunits of the enzyme have been performed. they show that the enzyme belongs to a group of uptake [nife] hydrogenases typical for cyanobacteria. the sequences have also a close relationship to those of the h(2)-sensor proteins, but clearly differ from those of standard [nife] hydrogenases. it is co ... | 2007 | 17082918 |
| bacterial removal of chromium (vi) and (iii) in a continuous system. | the capacity of acidithiobacillus ferrooxidans and acidithiobacillus thiooxidans to reduce different concentrations of hexavalent chromium in shake flask cultures has been investigated. a. ferrooxidans reduces 100% of chromium (vi) at concentrations of 1, 2.5 and 5 ppm, but in the presence of 10 ppm only 42.9% of chromium (vi) was reduced after 11 days of incubation. a. thiooxidans showed a lower capacity to reduce this ion and total reduction of chromium (vi) was only obtained for concentration ... | 2007 | 17091343 |
| [lithotrophic microorganisms of the oxidative cycles of sulfur and iron]. | the review deals with sulfur bacteria (the first chemolithotrophs ever studied) and with the acidophilic bacteria of sulfur and iron cycles which were investigated as a result of winogradsky's discovery. the diversity of these organisms and the factors and mechanism of its origin are emphasized; their metabolic functions and nutritional regulation are discussed. | 2006 | 17091584 |
| microbially-influenced degradation of solidified/stabilized metal waste. | in the present study, a refined microbially-influenced degradation method was used to evaluate the stability of a solidified synthetic waste containing chromium salt, cement and fly ash in two different proportions. the experimental samples showed evidence of microbial growth by leaching of sulfate. chromium leached by thiobacillus thiooxidans from the experimental samples 'c1' (10.26% crcl3 .6h2o; 89.74% cement) and 'fc1' (10.26% crcl3 .6h2o; 10% fly ash; 79.74% cement), after 30 days of exposu ... | 2007 | 17107784 |
| novel bacterial sulfur oxygenase reductases from bioreactors treating gold-bearing concentrates. | the microbial community and sulfur oxygenase reductases of metagenomic dna from bioreactors treating gold-bearing concentrates were studied by 16s rrna library, real-time polymerase chain reaction (rt-pcr), conventional cultivation, and molecular cloning. results indicated that major bacterial species were belonging to the genera acidithiobacillus, leptospirillum, sulfobacillus, and sphingomonas, accounting for 6.3, 66.7, 18.8, and 8.3%, respectively; the sole archaeal species was ferroplasma sp ... | 2007 | 17111141 |
| expression, purification and molecular modelling of the iro protein from acidithiobacillus ferrooxidans fe-1. | the iro protein was proposed to be involved in the iron respiratory electron transport chain in acidithiobacillus ferrooxidans, it is a member of hipip family with the iron-sulfur cluster for electron transfer. the gene of iro protein from a. ferrooxidans fe-1 was cloned and then successfully expressed in escherichia coli, finally purified by one-step affinity chromatography to homogeneity. the recombinant protein was observed to be dimer. the molecular mass of a monomer containing the [fe4s4] c ... | 2007 | 17140808 |
| succession of sulfur-oxidizing bacteria in the microbial community on corroding concrete in sewer systems. | microbially induced concrete corrosion (micc) in sewer systems has been a serious problem for a long time. a better understanding of the succession of microbial community members responsible for the production of sulfuric acid is essential for the efficient control of micc. in this study, the succession of sulfur-oxidizing bacteria (sob) in the bacterial community on corroding concrete in a sewer system in situ was investigated over 1 year by culture-independent 16s rrna gene-based molecular tec ... | 2007 | 17142362 |
| cloning and characterization of the chromosomal arsenic resistance genes from acidithiobacillus caldus and enhanced arsenic resistance on conjugal transfer of ars genes located on transposon tnatcars. | all strains of the moderately thermophilic, acidophilic, sulphur-oxidizing bacterium acidithiobacillus caldus that have been tested contain a set of chromosomal arsenic resistance genes. highly arsenic-resistant strains isolated from commercial arsenopyrite bio-oxidation tanks contain additional transposon-located (tnatcars) arsenic resistance genes. the chromosomal at. caldus ars genes were cloned and found to consist of arsr and arsc genes transcribed in one direction, and arsb in the opposite ... | 2006 | 17159207 |