| hydrogen-oxidizing electron transport components in the hyperthermophilic archaebacterium pyrodictium brockii. | the hyperthermophilic archaebacterium pyrodictium brockii grows optimally at 105 degrees c by a form of metabolism known as hydrogen-sulfur autotrophy, which is characterized by the oxidation of h2 by s0 to produce atp and h2s. uv-irradiated membranes were not able to carry out the hydrogen-dependent reduction of sulfur. however, the activity could be restored by the addition of ubiquinone q10 or ubiquinone q6 to the uv-damaged membranes. a quinone with thin-layer chromatography migration proper ... | 1992 | 1309514 |
| posttranscriptional modification of trna in thermophilic archaea (archaebacteria). | nucleoside modification has been studied in unfractionated trna from 11 thermophilic archaea (archaebacteria), including phylogenetically diverse representatives of thermophilic methanogens and sulfur-metabolizing hyperthermophiles which grow optimally in the temperature range of 56 (thermoplasma acidophilum) to 105 degrees c (pyrodictium occultum), and for comparison from the most thermophilic bacterium (eubacterium) known, thermotoga maritima (80 degrees c). nine nucleosides are found to be un ... | 1991 | 1708763 |
| a novel atpase complex selectively accumulated upon heat shock is a major cellular component of thermophilic archaebacteria. | we have discovered a large cylindrical protein complex which is an abundant component of the cytoplasm of extremely thermophilic archaebacteria. structural analysis by image processing of electron micrographs suggests that the complex is composed of two stacked rings of eight subunits each; the rings enclose a central channel. the complex purified from the hyperthermophile pyrodictium occultum is composed of equal quantities of two polypeptides of mr 56,000 and 59,000. it exhibits an extremely t ... | 1991 | 1828761 |
| purification and characterization of the hydrogen uptake hydrogenase from the hyperthermophilic archaebacterium pyrodictium brockii. | pyrodictium brockii is a hyperthermophilic archaebacterium with an optimal growth temperature of 105 degrees c. p. brockii is also a chemolithotroph, requiring h2 and co2 for growth. we have purified the hydrogen uptake hydrogenase from membranes of p. brockii by reactive red affinity chromatography and sucrose gradient centrifugation. the molecular mass of the holoenzyme was 118,000 +/- 19,000 da in sucrose gradients. the holoenzyme consisted of two subunits by sodium dodecyl sulfate-polyacryla ... | 1991 | 1900502 |
| distribution of folates and modified folates in extremely thermophilic bacteria. | analyses were made of the structures and levels of folates and modified folates present in extremely thermophilic bacteria. these procedures involved the chemical analysis of products resulting from the oxidative cleavage of the 6-substituted, folatelike tetrahydropterins present in the cells. air-oxidized cell extracts of extreme thermophiles from two members of the archaebacterial order thermococcales, thermococcus celer and pyrococcus furiosus, contained only 7-methylpterin, indicating that t ... | 1991 | 1900506 |
| hyperthermus butylicus, a hyperthermophilic sulfur-reducing archaebacterium that ferments peptides. | the hyperthermophilic peptide-fermenting sulfur archaebacterium hyperthermus butylicus was isolated from the sea floor of a solfataric habitat with temperatures of up to 112 degrees c on the coast of the island of são miguel, azores. the organism grows at up to 108 degrees c, grows optimally between 95 and 106 degrees c at 17 g of nacl per liter and ph 7.0, utilizes peptide mixtures as carbon and energy sources, and forms h2s from elemental sulfur and molecular hydrogen as a growth-stimulating a ... | 1990 | 2113915 |
| hydrogen-sulfur autotrophy in the hyperthermophilic archaebacterium, pyrodictium brockii. | | 1990 | 2128798 |
| characterization of hydrogen-uptake activity in the hyperthermophile pyrodictium brockii. | pyrodictium brockii is a hyperthermophilic archaebacterium with an optimal growth temperature of 105 degrees c. p. brockii is also a chemolithotroph, requiring h2 and co2 for growth. we have characterized p. brockii hydrogen-uptake activity with regard to temperature, ability to couple hydrogen oxidation to artificial electron acceptor reduction, sensitivity to o2, and cellular localization. the hydrogen-uptake activity was localized predominantly in a particulate fraction, was reversibly inhibi ... | 1989 | 2492097 |
| structure determination of a new fluorescent tricyclic nucleoside from archaebacterial trna. | a highly fluorescent nucleoside was detected in enzymatic digests of the extremely thermophilic archaebacterium sulfolobus solfataricus by combined liquid chromatography-mass spectrometry (lc/ms). following isolation, the structure was determined primarily by mass spectrometry, to be 3-(beta-d-ribofuranosyl)-4,9-dihydro-4,6,7-trimethyl-9-oxoimidazo[ 1, 2-a]purine (mimg), a new derivative of the y (wye) nucleoside. the structural assignment was verified by comparison of the base released by acid ... | 1987 | 3103099 |
| vitamin contents of archaebacteria. | the levels of six water-soluble vitamins of seven archaebacterial species were determined and compared with the levels found in a eubacterium, escherichia coli. biotin, riboflavin, pantothenic acid, nicotinic acid, pyridoxine, and lipoic acid contents of halobacterium volcanii, methanobacterium thermoautotrophicum delta h, "archaeoglobus fulgidus" vc-16, thermococcus celer, pyrodictium occultum, thermoproteus tenax, and sulfolobus solfataricus were measured by using bioassays. the archaebacteria ... | 1988 | 3137215 |
| correlation averaging of a badly distorted lattice: the surface protein of pyrodictium occultum. | the surface protein of the archaebacterium pyrodictium occultum forms two-dimensional periodic arrays of extremely poor order. two variants of correlation averaging have been applied in order to retrieve the unit cell structure from electron micrographs of negatively stained samples: straightforward correlation averaging correcting for lateral displacements only and a more elaborate approach, including a partial compensation for rotational disorder. surprisingly, both routes yield virtually iden ... | 1988 | 3143815 |
| 5'-methylbenzimidazolyl-cobamides are the corrinoids from some sulfate-reducing and sulfur-metabolizing bacteria. | the sulfate-reducing bacteria desulfobacterium autotrophicum, desulfobulbus propionicus and archaeoglobus fulgidus (vc-16) and the sulfur-metabolizing archaebacteria desulfurolobus ambivalens and thermoplasma acidophilum were found to contain considerable amounts of corrinoids, that were isolated and crystallized in their co beta-cyano form. in three other sulfur-metabolizing archaebacteria, thermoproteus neutrophilus, pyrodictium occultum and staphylothermus marinus significant amounts of corri ... | 1988 | 3416881 |
| the role of posttranscriptional modification in stabilization of transfer rna from hyperthermophiles. | the influence of posttranscriptional modification on structural stabilization of trna from hyperthermophilic archaea was studied, using pyrococcus furiosus (growth optimum 100 degrees c) as a primary model. optical melting temperatures (tm) of unfractionated trna in 20 mm mg2+ are 97 degrees c for p. furiosus and 101.5 degrees c for pyrodictium occultum (growth optimum, 105 degrees c). these values are approximately 20 degrees c higher than predicted solely from g-c content and are attributed pr ... | 1994 | 7516708 |
| structural characterization of modified nucleosides in trna hydrolysates by frit-fast atom bombardment liquid chromatography/mass spectrometry. | feasibility for the structural characterization of modified nucleosides in transfer rna at low microgram levels has been investigated by using continuous-flow frit-fast atom bombardment liquid chromatography/mass spectrometry (frit-fab lc/ms). sample of trna(phe) from brewer's yeast (saccharomyces cerevisiae) was used as a main model, and enzymatically hydrolysed by nuclease p1 and alkaline phosphatase. the resulting nucleoside mixture was separated by using a microbore reversed-phase lc column ... | 1994 | 7522577 |
| the hyperthermophilic archaeon pyrodictium occultum has two alpha-like dna polymerases. | we cloned two genes encoding dna polymerases from the hyperthermophilic archaeon pyrodictium occultum. the deduced primary structures of the two gene products have several amino acid sequences which are conserved in the alpha-like (family b) dna polymerases. both genes were expressed in escherichia coli, and highly purified gene products, dna polymerases i and ii (pol i and pol ii), were biochemically characterized. both dna polymerase activities were heat stable, but only pol ii was sensitive t ... | 1995 | 7721707 |
| rapid differentiation of hyperthermophilic archaea by restriction mapping of the intergenic spacer regions of the ribosomal rna operons. | we report a sensitive and convenient method for rapid differentiation of new isolates of hyperthermophilic archaea. polymerase chain reaction (pcr) was used to amplify the intergenic spacer regions of the ribosomal rna operons of eight archaea. spacer regions from one euryarcheote, pyrococcus furiosus, and one crenarcheote, pyrodictium brockii, were sequenced completely. restriction fragment length polymorphism (rflp) analyses were performed on the spacer regions from eight hyperthermophilic arc ... | 1995 | 7773330 |
| detection of ribose-methylated nucleotides in pyrodictium occultum trna by liquid chromatography--frit-fast atom bombardment mass spectrometry. | ribose-methylated dinucleotides of the type nmpn' derived from digestion of trna with rnase t2 were separated and characterized by directly combined liquid chromatography--mass spectrometry (lc-ms) with a continuous-flow frit-fast atom bombardment (frit-fab) interface. prediction of nmpn' peaks was readily made by comparison of the lc profile with that of comparative nuclease p1 digest. the identity of the candidate peaks including nmpn' was further recognized by the mass spectra, in which nmpn' ... | 1994 | 7866511 |
| heat shock promoter of thermophilic chaperonin operon. | the translation of a heat shock protein (hsp), tgroel, of thermophilic bacterium ps3 increased within 10 minutes when the culture temperature was raised from 60 degrees c to 70 degrees c. in contrast to hyperthermophilic hsps such as pyrodictium atpase, tgroel is homologous to groel of e. coli (tamada et al. (1991) biochem. biophys. res. commun. 197, 565-571). the promoter of the thermophilic heat shock gene (tgre) was sequenced to analyze the heat shock response. the sequences of the promoter w ... | 1993 | 8096382 |
| 5s rrna modification in the hyperthermophilic archaea sulfolobus solfataricus and pyrodictium occultum. | the 5s rrnas from sulfolobus solfataricus and pyrodictium occultum were digested to nucleosides and analyzed using directly-combined hplc/mass spectrometry. p. occultum 5s rrna contains two modified nucleoside species, n4-acetylcytidine (ac4c) and n4-acetyl-2'-o-methylcytidine (ac4cm). oligonucleotides were generated from p. occultum 5s rrna by rnase t1 hydrolysis, and their molecular weights were determined using electrospray mass spectrometry and compared with those predicted from the p. occul ... | 1993 | 8422966 |
| cloning and sequencing of a gene encoding 16s ribosomal rna from a novel hyperthermophilic archaebacterium nc12. | a hyperthermophile nc12 was newly isolated from noboribetsu hot spring. to characterize this organism, a gene coding for 16s rrna was cloned and sequenced. the 16s rrna sequence from nc12 shows the highest similarity with those from pyrodictium occultum and desulfurococcus mobilis among the sequences in the database, indicating that nc12 belongs to a cluster of extreme thermophiles (crenarchaeota) in the archaeal domain. however, since the highest identity score was only 91.2%, it is suggested t ... | 1996 | 8973365 |
| gene duplications in evolution of archaeal family b dna polymerases. | all archaeal dna-dependent dna polymerases sequenced to date are homologous to family b dna polymerases from eukaryotes and eubacteria. presently, representatives of the euryarchaeote division of archaea appear to have a single family b dna polymerase, whereas two crenarchaeotes, pyrodictium occultum and sulfolobus solfataricus, each possess two family b dna polymerases. we have found the gene for yet a third family b dna polymerase, designated b3, in the crenarchaeote s. solfataricus p2. the en ... | 1997 | 9098062 |
| structural feature of the initiator trna gene from pyrodictium occultum and the thermal stability of its gene product, trna(imet). | pyrodictium occultum is a hyperthermophilic archaeum that grows optimally at 105 degrees c. to study how trna molecules in p occulrum are thermally stabilized, we isolated the initiator trna gene from the organism using a synthetic dna probe of 74 bp containing the known nucleotide sequences that are conserved in archaeal initiator trnas. a hindiii fragment of 700 bp containing the pyrodictium initiator trna gene was cloned and sequenced by cycle sequencing. the nucleotide sequence revealed that ... | 1996 | 9116054 |
| characterization of a dna polymerase from the uncultivated psychrophilic archaeon cenarchaeum symbiosum. | cenarchaeum symbiosum, an archaeon which lives in specific association with a marine sponge, belongs to a recently recognized nonthermophilic crenarchaeotal group that inhabits diverse cold and temperate environments. nonthermophilic crenarchaeotes have not yet been obtained in laboratory culture, and so their phenotypic characteristics have been inferred solely from their ecological distribution. here we report on the first protein to be characterized from one of these organisms. the dna polyme ... | 1997 | 9401041 |
| purification and properties of an extremely thermostable membrane-bound sulfur-reducing complex from the hyperthermophilic pyrodictium abyssi. | the chemolithoautotrophic archaeon pyrodictium abyssi isolate tag 11 gains energy by reducing sulfur with h2 to h2s. from this hyperthermophile, a sulfur-reducing complex catalyzing this reaction was purified 13.5-fold. the native complex exhibited a brownish-yellow colour and showed an apparent molecular mass of 520 kda. sds/page revealed the presence of nine different major polypeptides with apparent molecular masses of 82, 72, 65, 50, 47, 42, 40, 30 and 24 kda. the native complex contained 50 ... | 1998 | 9546664 |
| 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 |
| molecular cloning and functional expression of a protein-serine/threonine phosphatase from the hyperthermophilic archaeon pyrodictium abyssi tag11. | an open reading frame coding for a putative protein-serine/threonine phosphatase was identified in the hyperthermophilic archaeon pyrodictium abyssi tag11 and named py-pp1. py-pp1 was expressed in escherichia coli, purified from inclusion bodies, and biochemically characterized. the phosphatase gene is part of an operon which may provide, for the first time, insight into a physiological role for archaeal protein phosphatases in vivo. | 1998 | 9696747 |
| recombinant homo- and hetero-oligomers of an ultrastable chaperonin from the archaeon pyrodictium occultum show chaperone activity in vitro. | the archaeon pyrodictium occultum is one of the most thermophilic organisms presently known. previous experiments provided support for the significant contribution of a high-molecular-mass protein complex to the extreme thermotolerance of p. occultum. this protein complex, the 'thermosome', is composed of two subunits, alpha and beta, which form a hexadecameric double ring complex. in order to obtain the thermosome in amounts sufficient for structural and functional investigations, we produced t ... | 1998 | 9874254 |
| extremophiles and their adaptation to hot environments. | water-containing terrestrial, subterranean and submarine high temperature areas harbor a variety of hyperthermophilic bacteria and archaea which are able to grow optimally above 80 degrees c. hyperthermophiles are adapted to hot environments by their physiological and nutritional requirements. as a consequence, cell components like proteins, nucleic acids and membranes have to be stable and even function best at temperatures around 100 degrees c. the chemolithoautotrophic archaeon pyrolobus fuma ... | 1999 | 10376671 |
| in vivo observation of cell division of anaerobic hyperthermophiles by using a high-intensity dark-field microscope. | to study growth and cell division of anaerobic hyperthermophilic archaea in vivo, a cultivation technique using glass capillaries was developed. at temperatures of 90 to 98 degrees c, at least 10 successive cell divisions of pyrodictium abyssi tag 11 were documented. cells divide by binary fission. visualized under a modified dark-field microscope, the formation of cannulae, which finally connected all cells, was observed. the cannulae elongated at 1.0 to 1.5 micrometers/min and reached final le ... | 1999 | 10438790 |
| two family b dna polymerases from aeropyrum pernix, an aerobic hyperthermophilic crenarchaeote. | dna polymerase activities in fractionated cell extract of aeropyrum pernix, a hyperthermophilic crenarchaeote, were investigated. aphidicolin-sensitive (fraction i) and aphidicolin-resistant (fraction ii) activities were detected. the activity in fraction i was more heat stable than that in fraction ii. two different genes (pola and polb) encoding family b dna polymerases were cloned from the organism by pcr using degenerated primers based on the two conserved motifs (motif a and b). the deduced ... | 1999 | 10498710 |
| cloning and characterization of a family b dna polymerase from the hyperthermophilic crenarchaeon pyrobaculum islandicum. | in order to extend the limited knowledge about crenarchaeal dna polymerases, we cloned a gene encoding a family b dna polymerase from the hyperthermophilic crenarchaeon pyrobaculum islandicum. the enzyme shared highest sequence identities with a group of phylogenetically related dna polymerases, designated b3 dna polymerases, from members of the kingdom crenarchaeota, pyrodictium occultum and aeropyrum pernix, and several members of the kingdom euryarchaeota. six highly conserved regions as well ... | 2000 | 10633098 |
| atp synthesis at 100 degrees c by an atpase purified from the hyperthermophilic archaeon pyrodictium abyssi. | the chemolithoautotrophic archaeon pyrodictium abyssi isolate tag 11 lives close to 100 degrees c and gains energy by sulfur respiration, with hydrogen as electron donor. from the membranes of this hyperthermophile, an atpase complex was isolated. the purified enzyme consists of six major polypeptides, the 67, 51, 41, 26 and 22 kda subunits composing the af(1) headpiece, and the 7 kda proteolipid of the af(0) component. the headpiece of the enzyme restored the formation of atp during sulfur resp ... | 2000 | 10664465 |
| sequence analysis of three family b dna polymerases from the thermoacidophilic crenarchaeon sulfurisphaera ohwakuensis. | three family b dna polymerase genes, designated b1, b2, and b3, were cloned from the thermoacidophilic crenarchaeon sulfurisphaera ohwakuensis, and sequenced. deduced amino acid sequences of b1 and b3 dna polymerases have all exonuclease and polymerase motifs which include critical residues for catalytic activities. furthermore, a yxgg/a motif, which is located between 3'-5' exonuclease and polymerization domains of family b dna polymerases, was also found in each of the b1 and b3 sequences. the ... | 2000 | 10997874 |
| hydrogen-sulfur oxidoreductase complex from pyrodictium abyssi. | | 2001 | 11265482 |
| archaebacterial phylogeny: perspectives on the urkingdoms. | comparisons of complete 16s ribosomal rna sequences have been used to confirm, refine and extend earlier concepts of archaebacterial phylogeny. the archaebacteria fall naturally into two major branches or divisions, i--the sulfur-dependent thermophilic archaebacteria, and ii--the methanogenic archaebacteria and their relatives. division i comprises a relatively closely related and phenotypically homogeneous collection of thermophilic sulfur-dependent species--encompassing the genera sulfolobus ... | 1986 | 11542063 |
| gene duplication and gene conversion shape the evolution of archaeal chaperonins. | chaperonins are multi-subunit double-ring complexes that mediate the folding of nascent or denatured proteins. gene duplication has been a potent force in the evolution of chaperonins in archaea. here we show that gene conversion has also been an important factor. we utilized a novel maximum likehood-based phylogenetic method for scanning dna sequence alignments for regions of anomalous phylogenetic signal, such as those affected by gene conversion. our results suggest that in crenarchaeotes, wh ... | 2002 | 11884142 |
| physiological aspects involved in production of xylanolytic enzymes by deep-sea hyperthermophilic archaeon pyrodictium abyssi. | xylanases (ec 3.2.1.8) catalyze the hydrolysis of xylan, the major constituent of hemicellulose. the use of these enzymes could greatly improve the overall economics of processing lignocellulosic materials for the generation of liquid fuels and chemicals. the hyperthermophilic archaeon pyrodictium abyssi, which was originally isolated from marine hot abyssal sites, grows optimally at 97 degrees c and is a prospective source of highly thermostable xylanase. its endoxylanase was shown to be highly ... | 2001 | 11963894 |
| pyrodictium cannulae enter the periplasmic space but do not enter the cytoplasm, as revealed by cryo-electron tomography. | the hyperthermophilic archaeon pyrodictium grows in the form of a macroscopically visible network. it consists of cells entrapped in an extracellular matrix of hollow tubules, the "cannulae." here, we present the three-dimensional structure of a single cell in conjunction with two extracellular cannulae, as determined by cryo-electron microscopy. to achieve this, the information from two independent tilt series of the same specimen was combined, with the specimen rotated in the second series. in ... | 2003 | 12576018 |
| 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 |
| the upper temperature of life--where do we draw the line? | a new archaeal isolate has been reported that is capable of growing at up to 121 degrees c. the hyperthermophile, dubbed strain 121, grows chemoautotrophically using formate as an electron donor and feiii as an electron acceptor and is closely related to members of the archaeal genera pyrodictium and pyrobaculum. although the reported maximum growth temperature of strain 121 is 8 degrees c higher than the previous record holder (pyrolobus fumarii; tmax = 113 degrees c), the two organisms have vi ... | 2004 | 15040324 |
| dissimilatory oxidation and reduction of elemental sulfur in thermophilic archaea. | the oxidation and reduction of elemental sulfur and reduced inorganic sulfur species are some of the most important energy-yielding reactions for microorganisms living in volcanic hot springs, solfataras, and submarine hydrothermal vents, including both heterotrophic, mixotrophic, and chemolithoautotrophic, carbon dioxide-fixing species. elemental sulfur is the electron donor in aerobic archaea like acidianus and sulfolobus. it is oxidized via sulfite and thiosulfate in a pathway involving both ... | 2004 | 15168612 |
| geomicrobiological exploration and characterization of a novel deep-sea hydrothermal system at the toto caldera in the mariana volcanic arc. | novel hydrothermal activities accompanying effluent white smokers and elemental sulfur chimney structures at the north-east lava dome of the toto caldera depression in the mariana volcanic arc have been explored and characterized by geochemical and microbiological surveys. white smoker hydrothermal fluids were observed in the potential hydrothermal activity centre of the field and represented the maximal temperature of 170 degrees c and the lowest ph of 1.6. the chimney structures, all consistin ... | 2006 | 16343320 |
| sulfur reduction by the extremely thermophilic archaebacterium pyrodictium occultum. | the relationship between growth and biological sulfur reduction for the extremely thermophilic archaebacterium pyrodictium occultum was studied over a temperature range of 98 to 105 degrees c. the addition of yeast extract (0.2 g/liter) to the medium was found to increase hydrogen sulfide production significantly, especially at higher temperatures. sulfide production in uninoculated controls with and without yeast extract was noticeable but substantially below the levels observed in samples cont ... | 1987 | 16347396 |
| organic solutes in hyperthermophilic archaea. | we examined the accumulation of organic solutes under optimum growth conditions in 12 species of thermophilic and hyperthermophilic archaea belonging to the crenarchaeota and euryarchaeota. pyrobaculum aerophilum, thermoproteus tenax, thermoplasma acidophilum, and members of the order sulfolobales accumulated trehalose. pyrococcus furiosus accumulated di-myo-inositol-1,1(prm1)(3,3(prm1))-phosphate and (beta)-mannosylglycerate, methanothermus fervidus accumulated cyclic-2,3-bisphosphoglycerate an ... | 1997 | 16535556 |
| hyperthermophiles in the history of life. | today, hyperthermophilic ('superheat-loving') bacteria and archaea are found within high-temperature environments, representing the upper temperature border of life. they grow optimally above 80 degrees c and exhibit an upper temperature border of growth up to 113 degrees c. members of the genera, pyrodictium and pyrolobus, survive at least 1h of autoclaving. in their basically anaerobic environments, hyperthermophiles (ht) gain energy by inorganic redox reactions employing compounds like molecu ... | 2006 | 17008222 |
| effect of hydrogen and carbon dioxide partial pressures on growth and sulfide production of the extremely thermophilic archaebacterium pyrodictium brockii. | the effect of hydrogen and carbon dioxide partial pressure on the growth of the extremely thermophilic archaebacterium pyrodictium brockii at 98 degrees c was investigated. previous work with this bacterium has been done using an 80:20 hydrogen-carbon dioxide gas phase with a total pressure of 4 atm; no attempt has been made to determine if this mixture is optimal. it was found in this study that reduced hydrogen partial pressures affected cell yield, growth rate, and sulfide production. the eff ... | 1988 | 18587740 |
| gain and loss of an intron in a protein-coding gene in archaea: the case of an archaeal rna pseudouridine synthase gene. | we previously found the first examples of splicing of archaeal pre-mrnas for homologs of the eukaryotic cbf5 protein (also known as dyskerin in humans) in aeropyrum pernix, sulfolobus solfataricus, s. tokodaii, and s. acidocaldarirus, and also showed that crenarchaeal species in orders desulfurococcales and sulfolobales, except for hyperthermus butylicus, pyrodictium occultum, pyrolobus fumarii, and ignicoccus islandicus, contain the (putative) cbf5 intron. however, the exact timing of the intro ... | 2009 | 19671140 |