| using protein synthesis inhibitors to establish the phylogenetic relationships of the sulfolobales order. | the sensitivity of the cell-free protein synthesis systems from acidanus brierleyi, acidianus infernus, and metallosphaera sedula, members of the archaeal order sulfolobales, to 40 antibiotics with different specificities has been studied. the sensitivity patterns were compared to those of sulfolobus solfataricus and other archaeal, bacterial, and eukaryotic systems. the comparative analysis shows that ribosomes from the sulfolobales are the most refractory to inhibitors of protein synthesis des ... | 1994 | 7807541 |
| [sulfurococcus yellowstonii sp. nov/--a new species of iron- and sulfur-oxidizing thermoacidophilic archaeobacterium]. | a spheric thermoacidophilic sulphur-oxidizing archaebacterium (strain str6kar) has been isolated from the hydrotherm of the yellowstone national park (usa). the isolate is a facultative autotroph. the strain str6kar oxidizes elemental sulfur, ferrous sulfate and sulphide minerals, it is capable of using some organic compounds. the isolate grows at the temperature of 40-80 degrees. the content of gc-pairs in the dna of the bacterium is 44.6 mol%. the level of homology of the isolates dna for the ... | 1994 | 7845250 |
| occurrence of tertiary and quaternary branched polyamines in thermophilic archaebacteria. | polyamines of thermophilic archaebacteria were analysed by high-performance liquid chromatography and gas chromatography. thermoplasma acidophilum and thermoplasma volcanium ubiquitously contained spermidine and spermine. four species of sulfolobus, s. acidocaldarius, s. solfataricus, s. metallicus and s. shibatae, two species of acidianus, a. brierleyi and a. infernus, and metallosphaera sedula, contained norspermidine and norspermine in addition to spermidine and spermine, but quantitative dis ... | 1994 | 7968661 |
| enzymes of aerobic respiration on iron. | bacteria capable of aerobic respiration on ferrous ions are spread throughout eubacterial and archaebacterial phyla. comparative spectroscopic analyses revealed that phylogenetically distinct organisms expressed copious quantities of spectrally distinct redox-active biomolecules during autotrophic growth on soluble iron. thiobacillus ferroxidans, leptospirillum ferrooxidans, sulfobacillus thermosulfidooxidans, and metallosphaera sedula possessed iron respiratory chains dominated by a blue copper ... | 1993 | 8357617 |
| estimation of genome sizes of hyperthermophiles. | genomes of various hyperthermophilic and extremely thermophilic prokaryotes were analyzed with respect to size, physical organization, and 16s rdna copy number. our results show that all the genomes are circular, and they are in the size range of 1.6-1.8 mb for pyrodictium abyssi, methanococcus igneus, pyrobaculum aerophilum, archaeoglobus fulgidus, archaeoglobus lithotrophicus, and archaeoglobus profundus (the two bacteria fervidobacterium islandicum and thermosipho africanus possess genomes of ... | 1998 | 9672684 |
| sulfurisphaera ohwakuensis gen. nov., sp. nov., a novel extremely thermophilic acidophile of the order sulfolobales. | three spherical thermoacidophilic archaea (strains ta-1t, ta-13, ta-14) were obtained from acidic hot springs located in ohwaku valley, hakone, japan. all the isolates are facultatively anaerobic, and grew optimally at around 85 degrees c, ph 2.0. isolate ta-1t was characterized further. the g + c content of dna from ta-1t is 33 mol%. although these properties resemble those of the genus acidianus, the sequence of the 16s rrna gene from strain ta-1t was more similar to that of species of stygiol ... | 1998 | 9731283 |
| presence of acetyl coenzyme a (coa) carboxylase and propionyl-coa carboxylase in autotrophic crenarchaeota and indication for operation of a 3-hydroxypropionate cycle in autotrophic carbon fixation. | the pathway of autotrophic co2 fixation was studied in the phototrophic bacterium chloroflexus aurantiacus and in the aerobic thermoacidophilic archaeon metallosphaera sedula. in both organisms, none of the key enzymes of the reductive pentose phosphate cycle, the reductive citric acid cycle, and the reductive acetyl coenzyme a (acetyl-coa) pathway were detectable. however, cells contained the biotin-dependent acetyl-coa carboxylase and propionyl-coa carboxylase as well as phosphoenolpyruvate ca ... | 1999 | 9973333 |
| biooxidation capacity of the extremely thermoacidophilic archaeon metallosphaera sedula under bioenergetic challenge | the biooxidation capacity of an extremely thermoacidophilic archaeon metallosphaera sedula (dsmz 5348) was examined under bioenergetic challenges imparted by thermal or chemical stress in regard to its potential use in microbial bioleaching processes. within the normal growth temperature range of m. sedula (70-79 degrees c) at ph 2.0, upward temperature shifts resulted in bioleaching rates that followed an arrhenius-like dependence. when the cells were subjected to supraoptimal temperatures thro ... | 1998 | 10099299 |
| analysis of intact tetraether lipids in archaeal cell material and sediments by high performance liquid chromatography/atmospheric pressure chemical ionization mass spectrometry. | a method combining normal phase high performance liquid chromatography (hplc) with positive ion atmospheric pressure chemical ionization mass spectrometry (apci-ms) was developed for the analysis of intact glycerol dialkyl glycerol tetraethers (gdgts) in archaeal cell material and sediments. all gdgts previously reported to occur in the thermophilic archaeon sulfolobus solfataricus could be identified based on their mass spectra and retention time. positive ion mass spectra consisted of abundant ... | 2000 | 10775092 |
| stable carbon isotope fractionations of the hyperthermophilic crenarchaeon metallosphaera sedula. | the stable carbon isotopic compositions of the inorganic carbon source, bulk cell material, and isoprenoid lipids of the hyperthermophilic crenarchaeon metallosphaera sedula, which uses a 3-hydroxypropionate-like pathway for autotrophic carbon fixation, have been measured. bulk cell material was approximately 3 per thousand enriched in 13c relative to the dissolved inorganic carbon, and 2 per thousand depleted in 13c relative to isoprenoid membrane lipids. the isotope data suggested that m. sedu ... | 2001 | 11257550 |
| metallosphaera sedula ta-2, a calditoglycerocaldarchaeol deletion strain of a thermoacidophilic archaeon. | a spherical thermoacidophilic archaeon, strain ta-2, was obtained from acidic hot springs located in ohwaku valley, hakone, japan. this isolate is an obligate aerobic chemoorganoheterotroph that grows optimally at about 75 degrees c, ph 2.8. the g + c content of dna from ta-2 is 47 mol%. the 16s rrna gene from ta-2 showed more than 99% similarity with those of metallosphaera sedula and metallosphaera prunae and less than 92% similarity with other members of the order sulfolobales. dna-dna hybrid ... | 2001 | 11523893 |
| characterization of acetyl-coa/propionyl-coa carboxylase in metallosphaera sedula. carboxylating enzyme in the 3-hydroxypropionate cycle for autotrophic carbon fixation. | autotrophic archaea of the family sulfolobaceae (crenarchaeota) use a modified 3-hydroxypropionate cycle for carbon dioxide assimilation. in this cycle the atp-dependent carboxylations of acetyl-coa and propionyl-coa to malonyl-coa and methylmalonyl-coa, respectively, represent the key co2 fixation reactions. these reactions were studied in the thermophilic and acidophilic metallosphaera sedula and are shown to be catalyzed by one single large enzyme, which acts equally well on acetyl-coa and pr ... | 2003 | 12581213 |
| autotrophic co2 fixation pathways in archaea (crenarchaeota). | representative autotrophic and thermophilic archaeal species of different families of crenarchaeota were examined for key enzymes of the known autotrophic co(2) fixation pathways. pyrobaculum islandicum ( thermoproteaceae) contained key enzymes of the reductive citric acid cycle. this finding is consistent with the operation of this pathway in the related thermoproteus neutrophilus. pyrodictium abyssi and pyrodictium occultum ( pyrodictiaceae) contained ribulose 1,5-bisphosphate carboxylase, whi ... | 2003 | 12610721 |
| in situ accessibility of small-subunit rrna of members of the domains bacteria, archaea, and eucarya to cy3-labeled oligonucleotide probes. | low accessibility of the rrna is together with cell wall impermeability and low cellular ribosome content a frequent reason for failure of whole-cell fluorescence hybridization with fluorescently labeled oligonucleotide probes. in this study we compare accessibility data for the 16s rrna of escherichia coli (gamma proteobacteria, bacteria) with the phylogenetically distantly related organisms pirellula sp. strain 1 (planctomycetes, bacteria) and metallosphaera sedula (crenarchaeota, archaea) and ... | 2003 | 12620867 |
| reclassification of sulfolobus hakonensis takayanagi et al. 1996 as metallosphaera hakonensis comb. nov. based on phylogenetic evidence and dna g+c content. | the taxonomic status of sulfolobus hakonensis takayanagi et al. 1996 was re-evaluated by fresh determinations of the 16s rdna sequence and g+c content of the genomic dna of the type strain, ho1-1(t). the 16s rdna sequence of strain ho1-1(t) showed 98 % similarity to those of two metallosphaera species and only </=92 % similarity to those of other sulfolobus species. the dna g+c content (46.2 mol%) is in accordance with those of metallosphaera species. in addition, strain ho1-1(t) shares some phe ... | 2003 | 13130056 |
| occurrence, biochemistry and possible biotechnological application of the 3-hydroxypropionate cycle. | the 3-hydroxypropionate cycle, a pathway for autotrophic carbon dioxide fixation, is reviewed with special emphasis on the biochemistry of co2 fixing enzymes in acidianus brierleyi, a thermophilic and acidophilic archeon. in the 3-hydroxypropionate cycle, two enzymes, acetyl-coa carboxylase and propionyl-coa carboxylase, catalyze co2 fixation. it has been shown in a. brierleyi, and subsequently in metallosphaera sedula, that acetyl-coa carboxylase is promiscuous, acting equally well on acetyl-co ... | 2004 | 14997352 |
| respiratory gene clusters of metallosphaera sedula - differential expression and transcriptional organization. | metallosphaera sedula is a thermoacidophilic crenarchaeon which is capable of leaching metals from sulfidic ores. the authors have investigated the presence and expression of genes encoding respiratory complexes in this organism when grown heterotrophically or chemolithotrophically on either sulfur or pyrite. the presence of three gene clusters, encoding two terminal oxidase complexes, the quinol oxidase soxabcd and the soxm oxidase supercomplex, and a gene cluster encoding a high-potential cyto ... | 2005 | 15632423 |
| an improved method for single cell isolation of prokaryotes from meso-, thermo- and hyperthermophilic environments using micromanipulation. | this study presents an improved system that enables isolation of single viable prokaryotic cells from a mixture of cells. the system is based on an inverted microscope, a microinjector and a micromanipulator. the isolated cell is captured in a microcapillary from a volume of 400 mul and transferred to an appropriate growth medium. validation of the system was performed using two fluorescent strains: pseudomonas putida expressing red fluorescent protein (dsred), and escherichia coli expressing gr ... | 2006 | 16034558 |
| coal depyritization by the thermophilic archaeon metallosphaera sedula. | the kinetics of pyrite oxidation by metallosphaera sedula were investigated with mineral pyrite and two coals with moderate (pittsburgh no. 8) and high (new brunswick, canada) pyritic sulfur content. m. sedula oxidized mineral pyrite at a greater rate than did another thermophile, acidianus brierleyi, or a mesophile, thiobacillus ferrooxidans. maximum rates of coal depyritization were also greater with m. sedula, although the magnitude of biological stimulation above abiotic rates was notably le ... | 1993 | 16349006 |
| bioenergetic response of the extreme thermoacidophile metallosphaera sedula to thermal and nutritional stresses. | the bioenergetic response of the extremely thermoacidophilic archaeon metallosphaera sedula to thermal and nutritional stresses was examined. continuous cultures (ph 2.0, 70(deg)c, and dilution rate of 0.05 h(sup-1)) in which the levels of casamino acids and ferrous iron in growth media were reduced by a step change of 25 to 50% resulted in higher levels of several proteins, including a 62-kda protein immunologically related to the molecular chaperone designated thermophilic factor 55 in sulfolo ... | 1995 | 16535051 |
| acquired thermotolerance and stressed-phase growth of the extremely thermoacidophilic archaeon metallosphaera sedula in continuous culture. | the response of an extremely thermoacidophilic archaeon, metallosphaera sedula (growth temperature range, 50 to 79(deg)c; optimum temperature, 74(deg)c; optimum ph, 2.0), to thermal stress was investigated by using a 10-liter continuous cultivation system. m. sedula, growing at 74(deg)c, ph 2.0, and a dilution rate of 0.04 hr(sup-1), was subjected to both abrupt and gradual temperature shifts in continuous culture to determine the responses of cell density levels and protein synthesis patterns. ... | 1997 | 16535631 |
| archaeal diversity in two thermophilic chalcopyrite bioleaching reactors. | this study used a culture-independent molecular approach to investigate the archaeal community composition of thermophilic bioleaching reactors. two culture samples, mtc-a and mtc-b, grown with different concentrations of chalcopyrite (cufes2), a copper sulfidic ore, at a temperature of 78 degrees c and ph 1.6 were studied. phylogenetic analysis of the 16s rrna genes revealed that both cultures consisted of archaea belonging to the sulfolobales. the 16s rrna gene clone library of mtc-a grown wit ... | 2006 | 17014503 |
| malonyl-coenzyme a reductase in the modified 3-hydroxypropionate cycle for autotrophic carbon fixation in archaeal metallosphaera and sulfolobus spp. | autotrophic members of the sulfolobales (crenarchaeota) contain acetyl-coenzyme a (coa)/propionyl-coa carboxylase as the co2 fixation enzyme and use a modified 3-hydroxypropionate cycle to assimilate co2 into cell material. in this central metabolic pathway malonyl-coa, the product of acetyl-coa carboxylation, is further reduced to 3-hydroxypropionate. extracts of metallosphaera sedula contained nadph-specific malonyl-coa reductase activity that was 10-fold up-regulated under autotrophic growth ... | 2006 | 17041055 |
| alkali-tolerant high-activity catalase from a thermophilic bacterium and its overexpression in escherichia coli. | we have purified an alkali-tolerant catalase from the thermophilic bacterium metallosphaera hakonensis. the catalase gene, which encodes 303 amino acids and has a calculated molecular mass of 33 kda, including its putative signal peptide encoding sequence, was cloned. the deduced amino acid sequence exhibited a region-specific homology with the sequences of manganese catalases from thermophilic bacteria such as thermus thermophilus and thermus brockianus. when this gene was overexpressed in esch ... | 2008 | 17983766 |
| molecular cloning and characterization of trehalose biosynthesis genes from hyperthermophilic archaebacterium metallosphaera hakonesis. | the trehalose (alpha-d-glucopyranosyl-[1,1]-alpha-d-glucopyranose) biosynthesis genes mhmts and mhmth, encoding a maltooligosyltrehalose synthase (mhmts) and a maltooligosyltrehalose trehalohydrolase (mhmth), respectively, have been cloned from the hyperthermophilic archaebacterium metallosphaera hakonesis. the orf of mhmts is 2,142 bp long, and encodes 713 amino acid residues constituting a 83.8 kda protein. mhmth is 1,677 bp long, and encodes 558 amino acid residues constituting a 63.7 kda pro ... | 2007 | 18051363 |
| a 3-hydroxypropionate/4-hydroxybutyrate autotrophic carbon dioxide assimilation pathway in archaea. | the assimilation of carbon dioxide (co2) into organic material is quantitatively the most important biosynthetic process. we discovered that an autotrophic member of the archaeal order sulfolobales, metallosphaera sedula, fixed co2 with acetyl-coenzyme a (acetyl-coa)/propionyl-coa carboxylase as the key carboxylating enzyme. in this system, one acetyl-coa and two bicarbonate molecules were reductively converted via 3-hydroxypropionate to succinyl-coa. this intermediate was reduced to 4-hydroxybu ... | 2007 | 18079405 |
| isolation and distribution of a novel iron-oxidizing crenarchaeon from acidic geothermal springs in yellowstone national park. | novel thermophilic crenarchaea have been observed in fe(iii) oxide microbial mats of yellowstone national park (ynp); however, no definitive work has identified specific microorganisms responsible for the oxidation of fe(ii). the objectives of the current study were to isolate and characterize an fe(ii)-oxidizing member of the sulfolobales observed in previous 16s rrna gene surveys and to determine the abundance and distribution of close relatives of this organism in acidic geothermal springs co ... | 2008 | 18083851 |
| the genome sequence of the metal-mobilizing, extremely thermoacidophilic archaeon metallosphaera sedula provides insights into bioleaching-associated metabolism. | despite their taxonomic description, not all members of the order sulfolobales are capable of oxidizing reduced sulfur species, which, in addition to iron oxidation, is a desirable trait of biomining microorganisms. however, the complete genome sequence of the extremely thermoacidophilic archaeon metallosphaera sedula dsm 5348 (2.2 mb, approximately 2,300 open reading frames [orfs]) provides insights into biologically catalyzed metal sulfide oxidation. comparative genomics was used to identify p ... | 2008 | 18083856 |
| 3-hydroxypropionyl-coenzyme a synthetase from metallosphaera sedula, an enzyme involved in autotrophic co2 fixation. | a modified 3-hydroxypropionate cycle has been proposed as the autotrophic co2 fixation pathway for the thermoacidophilic crenarchaeon metallosphaera sedula. the cycle requires the reductive conversion of 3-hydroxypropionate to propionyl-coenzyme a (propionyl-coa). the specific activity of the 3-hydroxypropionate-, coa-, and mgatp-dependent oxidation of nadph in autotrophically grown cells was 0.023 micromol min(-1) mg protein(-1). the reaction sequence is catalyzed by at least two enzymes. the f ... | 2008 | 18165310 |
| bifunctional recombinant fusion enzyme between maltooligosyltrehalose synthase and maltooligosyltrehalose trehalohydrolase of thermophilic microorganism metallosphaera hakonensis. | mhmts and mhmth are trehalose (alpha-d-glucopyranosyl- [1,1]-alpha-d-glucopyranose) biosynthesis genes of the thermophilic microorganism metallosphaera hakonensis, and encode a maltooligosyltrehalose synthase (mhmts) and a maltooligosyltrehalose trehalohydrolase (mhmth), respectively. in this study, the two genes were fused inframe in a recombinant dna, and expressed in escherichia coli to produce a bifunctional fusion enzyme, mhmtsh. similar to the two-step reactions with mhmts and mhmth, the f ... | 2008 | 18852510 |
| identification of components of electron transport chains in the extremely thermoacidophilic crenarchaeon metallosphaera sedula through iron and sulfur compound oxidation transcriptomes. | the crenarchaeal order sulfolobales collectively contain at least five major terminal oxidase complexes. based on genome sequence information, all five complexes are found only in metallosphaera sedula and sulfolobus tokodaii, the two sequenced sulfolobales capable of iron oxidization. while specific respiratory complexes in certain sulfolobales have been characterized previously as proton pumps for maintaining intracellular ph and generating proton motive force, their contribution to sulfur and ... | 2008 | 18931292 |
| 3-hydroxypropionyl-coenzyme a dehydratase and acryloyl-coenzyme a reductase, enzymes of the autotrophic 3-hydroxypropionate/4-hydroxybutyrate cycle in the sulfolobales. | a 3-hydroxypropionate/4-hydroxybutyrate cycle operates in autotrophic co(2) fixation in various crenarchaea, as studied in some detail in metallosphaera sedula. this cycle and the autotrophic 3-hydroxypropionate cycle in chloroflexus aurantiacus have in common the conversion of acetyl-coenzyme a (coa) and two bicarbonates via 3-hydroxypropionate to succinyl-coa. both cycles require the reductive conversion of 3-hydroxypropionate to propionyl-coa. in m. sedula the reaction sequence is catalyzed b ... | 2009 | 19429610 |
| acidianus, sulfolobus and metallosphaera surface layers: structure, composition and gene expression. | the cell walls of sulfolobales species consist of proteinaceous s-layers assembled from two polypeptides, slaa and slab. we isolated the large s-layer protein of acidianus ambivalens and both s-layer subunits of sulfolobus solfataricus and metallosphaera sedula, respectively. the slaab genes, lying adjacently in the chromosomes, are constitutively transcribed as bicistronic operons in a. ambivalens and s. solfataricus. a smaller slaa transcript appeared in northern hybridizations of a. ambivalen ... | 2009 | 19522740 |
| probing the archaeal diversity of a mixed thermophilic bioleaching culture by tgge and fish. | the archaeal community present in a sample of mixed thermophilic culture-b (mtc-b) from a laboratory-scale thermophilic bioleaching reactor was investigated by temperature gradient gel electrophoresis (tgge) and fluorescence in situ hybridisation (fish). both techniques were specifically adapted for use on native state bioleaching samples, with a view to establishing convenient means for monitoring culture composition. using the tgge protocol developed, the relative species composition of the th ... | 2009 | 19541445 |
| malonic semialdehyde reductase, succinic semialdehyde reductase, and succinyl-coenzyme a reductase from metallosphaera sedula: enzymes of the autotrophic 3-hydroxypropionate/4-hydroxybutyrate cycle in sulfolobales. | a 3-hydroxypropionate/4-hydroxybutyrate cycle operates during autotrophic co(2) fixation in various members of the crenarchaea. in this cycle, as determined using metallosphaera sedula, malonyl-coenzyme a (malonyl-coa) and succinyl-coa are reductively converted via their semialdehydes to the corresponding alcohols 3-hydroxypropionate and 4-hydroxybutyrate. here three missing oxidoreductases of this cycle were purified from m. sedula and studied. malonic semialdehyde reductase, a member of the 3- ... | 2009 | 19684143 |
| physiological versatility of the extremely thermoacidophilic archaeon metallosphaera sedula supported by transcriptomic analysis of heterotrophic, autotrophic, and mixotrophic growth. | comparative transcriptomic analysis of autotrophic, heterotrophic, and mixotrophic growth of the archaeon metallosphaera sedula (70 degrees c, ph 2.0) revealed candidates for yet-to-be-confirmed components of the 3-hydroxypropionate/4-hydroxybutyrate pathway and implicated a membrane-bound hydrogenase (msed_0944-msed_0946) for growth on h(2). routes for generation of atp and reducing equivalents were also identified. | 2010 | 20008169 |
| impact of molecular hydrogen on chalcopyrite bioleaching by the extremely thermoacidophilic archaeon metallosphaera sedula. | hydrogen served as a competitive inorganic energy source, impacting the cufes(2) bioleaching efficiency of the extremely thermoacidophilic archaeon metallosphaera sedula. open reading frames encoding key terminal oxidase and electron transport chain components were triggered by cufes(2). evidence of heterotrophic metabolism was noted after extended periods of bioleaching, presumably related to cell lysis. | 2010 | 20190092 |
| metallosphaera cuprina sp. nov., a novel species of acidothermophilic metal-mobilizing archaeon. | a novel acidothermophilic archaeon, named strain ar-4t, was isolated from a sulfuric hot spring in tengchong, yunnan, china. cells of strain ar-4t were gram-staining negative, irregular cocci, motile with flagella. strain ar-4t grew at a temperature range of 55-75°c (optimum, 65°c), a ph range of 2.5-5.5 (optimum, ph 3.5) and a nacl concentration range of 0-1 %. aerobic and facultatively chemolithoautotrophic. the strain could extract metal ions from sulfidic ore. it was also the oxidizer of red ... | 2010 | 21057050 |
| identification of missing genes and enzymes for autotrophic carbon fixation in crenarchaeota. | two autotrophic carbon fixation cycles have been identified in crenarchaeota. the dicarboxylate/4-hydroxybutyrate cycle functions in anaerobic or microaerobic autotrophic members of the thermoproteales and desulfurococcales. the 3-hydroxypropionate/4-hydroxybutyrate cycle occurs in aerobic autotrophic sulfolobales; a similar cycle may operate in autotrophic aerobic marine crenarchaeota. both cycles form succinyl-coenzyme a (coa) from acetyl-coa and two molecules of inorganic carbon, but they use ... | 2010 | 21169482 |
| labeling and enzyme studies of the central carbon metabolism in metallosphaera sedula. | metallosphaera sedula (sulfolobales, crenarchaeota) uses the 3-hydroxypropionate/4-hydroxybutyrate cycle for autotrophic carbon fixation. in this pathway, acetyl-coenzyme a (coa) and succinyl-coa are the only intermediates that can be considered common to the central carbon metabolism. we addressed the question of which intermediate of the cycle most biosynthetic routes branch off. we labeled autotrophically growing cells by using 4-hydroxy[1-¹⁴c]butyrate and [1,4-¹³c₁]succinate, respectively, a ... | 2010 | 21169486 |
| continuous culture as a tool for investigating the growth physiology of heterotrophic hyperthermophiles and extreme thermoacidophiles. | although there is great scientific and technological interest in examining the physiology and bioenergetics of microorganisms from extreme environments, difficulties encountered in their cultivation and lack of genetic systems hampers the investigation of these issues. as such, we have adapted methods for continuous cultivation of mesophilic organisms to extremes of temperature and ph to study extremophiles. since the risk for contamination of extremophilic continuous cultures is relatively smal ... | 1998 | 21182700 |
| sulfur oxidation activities of pure and mixed thermophiles and sulfur speciation in bioleaching of chalcopyrite. | the sulfur oxidation activities of four pure thermophilic archaea acidianus brierleyi (jcm 8954), metallosphaera sedula (yn 23), acidianus manzaensis (yn 25) and sulfolobus metallicus (yn 24) and their mixture in bioleaching chalcopyrite were compared. meanwhile, the relevant surface sulfur speciation of chalcopyrite leached with the mixed thermophilic archaea was investigated. the results showed that the mixed culture, with contributing significantly to the raising of leaching rate and accelera ... | 2010 | 21194927 |
| terminal oxidase diversity and function in "metallosphaera yellowstonensis": gene expression and protein modeling suggest mechanisms of fe(ii) oxidation in the sulfolobales. | "metallosphaera yellowstonensis" is a thermoacidophilic archaeon isolated from yellowstone national park that is capable of autotrophic growth using fe(ii), elemental s, or pyrite as electron donors. analysis of the draft genome sequence from m. yellowstonensis strain mk1 revealed seven different copies of heme copper oxidases (subunit i) in a total of five different terminal oxidase complexes, including doxbcef, foxabcdefghij, soxabc, and the soxm supercomplex, as well as a novel hypothetical t ... | 2011 | 21239558 |
| complete genome sequence of metallosphaera cuprina, a metal sulfide oxidizing archaeon from hotspring. | the genome of metal sulfide oxidizing, thermoacidiphilic metallosphaera cuprina ar-4 has been completely sequenced and annotated. originally isolated from a sulfuric hotspring, strain ar-4 grows optimally at 65 °c and ph of 3.5. the m. cuprina genome has a 1,840,348 bp circular chromosome (2029 orfs) and is 16% smaller than the previously sequenced metallosphaera sedula genome. compared to the m. sedula genome, there are no counterpart genes in the m. cuprina genome for about 480 orfs in the m. ... | 2011 | 21551305 |
| kinetics of ferrous iron oxidation by batch and continuous cultures of thermoacidophilic archaea at extremely low ph of 1.1-1.3. | the extreme acid conditions required for scorodite (feaso(4)·2h(2)o) biomineralization (ph below 1.3) are suboptimal for growth of most thermoacidophilic archaea. with the objective to develop a continuous process suitable for biomineral production, this research focuses on growth kinetics of thermoacidophilic archaea at low ph conditions. ferrous iron oxidation rates were determined in batch-cultures at ph 1.3 and a temperature of 75°c for acidianus sulfidivorans, metallosphaera prunea and a mi ... | 2011 | 21751006 |