| picrophilus gen. nov., fam. nov.: a novel aerobic, heterotrophic, thermoacidophilic genus and family comprising archaea capable of growth around ph 0. | two species belonging to a novel genus of archaea, designated picrophilus oshimae and picrophilus torridus, have been isolated from two different solfataric locations in northern japan. one habitat harboring both organisms was a dry, extremely acidic soil (ph < 0.5) that was heated by solfataric gases to about 55 degrees c. in the laboratory both species grew heterotrophically on yeast extract and poorly on tryptone under aerobic conditions at temperatures between 45 and 65 degrees c; they grew ... | 1995 | 8522509 |
| bioenergetics and cytoplasmic membrane stability of the extremely acidophilic, thermophilic archaeon picrophilus oshimae. | picrophilus oshimae is an extremely acidophilic, thermophilic archaeon that grows optimally at 60 degrees c and at ph 0.7. it is an obligatory acidophile that does not grow at ph values above 4.0. the proton motive force in respiring cells is composed of a large transmembrane ph gradient, inside less acid, and a reversed transmembrane electrical potential, inside positive. cells maintain an intracellular ph at around 4.6 at extracellular ph values ranging from 0.8 to 4.0. above ph 4.0 cells lyse ... | 1998 | 9672680 |
| ferroplasma acidiphilum gen. nov., sp. nov., an acidophilic, autotrophic, ferrous-iron-oxidizing, cell-wall-lacking, mesophilic member of the ferroplasmaceae fam. nov., comprising a distinct lineage of the archaea. | an isolate of an acidophilic archaeon, strain yt, was obtained from a bioleaching pilot plant. the organism oxidizes ferrous iron as the sole energy source and fixes inorganic carbon as the sole carbon source. the optimal ph for growth is 1.7, although growth is observed in the range ph 1.3 to 2.2. the cells are pleomorphic and without a cell wall. 16s rrna gene sequence analysis showed this strain to cluster phylogenetically within the order 'thermoplasmales' sensu woese, although with only 89. ... | 2000 | 10843038 |
| novel thermoactive glucoamylases from the thermoacidophilic archaea thermoplasma acidophilum, picrophilus torridus and picrophilus oshimae. | the thermoacidophilic archaea thermoplasma acidophilum (optimal growth at 60 degrees c and ph 1-2), picrophilus torridus and picrophilus oshimae (optimal growth at 60 degrees c and ph 0.7) were able to utilize starch as sole carbon source. during growth these microorganisms secreted heat and acid-stable glucoamylases into the culture fluid. applying sds gel electrophoresis activity bands were detected with appearent molecular mass (mw) of 141.0, 95.0 kda for t. acidophilum, 133.0, 90.0 kda for p ... | 2002 | 12448707 |
| genome sequence of picrophilus torridus and its implications for life around ph 0. | the euryarchaea picrophilus torridus and picrophilus oshimae are able to grow around ph 0 at up to 65 degrees c, thus they represent the most thermoacidophilic organisms known. several features that may contribute to the thermoacidophilic survival strategy of p. torridus were deduced from analysis of its 1.55-megabase genome. p. torridus has the smallest genome among nonparasitic aerobic microorganisms growing on organic substrates and simultaneously the highest coding density among thermoacidop ... | 2004 | 15184674 |
| another extreme genome: how to live at ph 0. | many archaea live under conditions that challenge the physico-chemical limits to life: low or high temperature, extremes of ph, elevated pressure and high salt concentration. a recent paper reports the genome sequence of another record-setting archaeon, picrophilus torridus, that thrives at 65 degrees c and ph 0. the genomic sequence provides several hints of the mechanisms used for adaptation to such hostile environment, but most secrets remain hidden and await further analysis to be disclosed. | 2005 | 15680761 |
| properties of the recombinant glucose/galactose dehydrogenase from the extreme thermoacidophile, picrophilus torridus. | in picrophilus torridus, a euryarchaeon that grows optimally at 60 degrees c and ph 0.7 and thus represents the most acidophilic thermophile known, glucose oxidation is the first proposed step of glucose catabolism via a nonphosphorylated variant of the entner-doudoroff pathway, as deduced from the recently completed genome sequence of this organism. the p. torridus gene for a glucose dehydrogenase was cloned and expressed in escherichia coli, and the recombinant enzyme, gdha, was purified and c ... | 2005 | 15691337 |
| identification of replication origins in archaeal genomes based on the z-curve method. | the z-curve is a three-dimensional curve that constitutes a unique representation of a dna sequence, i.e., both the z-curve and the given dna sequence can be uniquely reconstructed from the other. we employed z-curve analysis to identify one replication origin in the methanocaldococcus jannaschii genome, two replication origins in the halobacterium species nrc-1 genome and one replication origin in the methanosarcina mazei genome. one of the predicted replication origins of halobacterium species ... | 2005 | 15876567 |
| structuring of the genetic code took place at acidic ph. | i have observed that in multiple regression the number of codons specifying amino acids in the genetic code is positively correlated with the isoelectric point of amino acids and their molecular weight. therefore basic amino acids are, on average, codified in the genetic code by a larger number of codons, which seems to imply that the genetic code originated in an acidic 'intracellular' environment. moreover, i compare the proteins from picrophilus torridus and thermoplasma volcanium, which have ... | 2005 | 15978625 |
| glyceraldehyde dehydrogenases from the thermoacidophilic euryarchaeota picrophilus torridus and thermoplasma acidophilum, key enzymes of the non-phosphorylative entner-doudoroff pathway, constitute a novel enzyme family within the aldehyde dehydrogenase superfamily. | cells of picrophilus torridus, grown on glucose, contained all enzyme activities of a non-phosphorylative entner-doudoroff pathway, including glucose dehydrogenase, gluconate dehydratase, 2-keto-3-deoxygluconate aldolase, glyceraldehyde dehydrogenase (gadh), glycerate kinase (2-phosphoglycerate forming), enolase and pyruvate kinase. gadh was purified to homogeneity. the 115-kda homodimeric protein catalyzed the oxidation of glyceraldehyde with nadp+ at highest catalytic efficiency. nad+ was not ... | 2006 | 16458304 |
| insights into extreme thermoacidophily based on genome analysis of picrophilus torridus and other thermoacidophilic archaea. | thermoacidophiles are prokaryotic microorganisms with the stunning capability to survive and multiply at extremely low ph and simultaneously at high temperatures. the mechanisms by which these organisms, exclusively members of the archaea, cope with their harsh surroundings are poorly understood. the genome sequences of several representatives of the thermoacidophilic genera picrophilus, thermoplasma and sulfolobus have recently become available. genome-wide comparison has revealed a number of f ... | 2006 | 16621083 |
| characterization of glycerate kinase (2-phosphoglycerate forming), a key enzyme of the nonphosphorylative entner-doudoroff pathway, from the thermoacidophilic euryarchaeon picrophilus torridus. | picrophilus torridus has been shown to degrade glucose via a nonphosphorylative entner-doudoroff (ed) pathway. here we report the characterization of a key enzyme of this pathway, glycerate kinase (2-phosphoglycerate forming). the enzyme was purified 5,100-fold to homogeneity. the 95 kda homodimeric protein catalyzed the atp-dependent phosphorylation of glycerate specifically to 2-phosphoglycerate. the enzyme showed highest activity at 60 degrees c and ph 7.3, with atp as phosphoryl donor and mg ... | 2006 | 16684110 |
| prokaryotes that grow optimally in acid have purine-poor codons in long open reading frames. | in nucleic acids the n-glycosyl bonds between purines and their ribose sugar moities are broken under acid conditions. if one strand of a duplex dna segment were more vulnerable to mutation than the other, then the archaeon picrophilus torridus, with an optimum growth ph near zero, could have adapted by decreasing the purine content of that strand. yet, p. torridus has an optimum growth temperature near 60 degrees c, and thermophiles prefer purine-rich codons. we found that, as in other thermoph ... | 2007 | 16957882 |
| gene cloning, expression, and biochemical characterization of a recombinant trehalose synthase from picrophilus torridus in escherichia coli. | a trehalose synthase (tsase) gene from a hyperacidophilic, thermophilic archaea, picrophilus torridus, was synthesized using overlap extension pcr and transformed into escherichia coli for expression. the purified recombinant p. torridus tsase (ptts) showed an optimum ph and temperature of 6.0 and 45 degrees c, respectively, and the enzyme maintained high activity at ph 5.0 and 60 degrees c. kinetic analysis showed that the enzyme has a 2.5-fold higher catalytic efficiency (k(cat)/k(m)) for malt ... | 2006 | 16968068 |
| molecular and biochemical characterization of alpha-glucosidase and alpha-mannosidase and their clustered genes from the thermoacidophilic archaeon picrophilus torridus. | the genes encoding a putative alpha-glucosidase (agla) and an alpha-mannosidase (mana) appear to be physically clustered in the genome of the extreme acidophile picrophilus torridus, a situation not found previously in any other organism possessing agla or mana homologs. while archaeal alpha-glucosidases have been described, no alpha-mannosidase enzymes from the archaeal kingdom have been reported previously. transcription start site mapping and northern blot analysis revealed that despite their ... | 2006 | 17015651 |
| the cellular machinery of ferroplasma acidiphilum is iron-protein-dominated. | ferroplasma is a genus of the archaea, one of the three branches of the tree of life, and belongs to the order thermoplasmatales (euryarchaeota), which contains the most acidophilic microbes yet known. ferroplasma species live in acid mine drainage, acidic pools and environments containing sulphidic ores such as pyrite and characterized by ph values of 0-2 and high concentrations of ferrous iron and other heavy metals. f. acidiphilum strain y(t) is a chemoautotroph that grows optimally at ph 1.7 ... | 2007 | 17203061 |
| phylogenomic analysis of proteins that are distinctive of archaea and its main subgroups and the origin of methanogenesis. | the archaea are highly diverse in terms of their physiology, metabolism and ecology. presently, very few molecular characteristics are known that are uniquely shared by either all archaea or the different main groups within archaea. the evolutionary relationships among different groups within the euryarchaeota branch are also not clearly understood. | 2007 | 17394648 |
| thermogymnomonas acidicola gen. nov., sp. nov., a novel thermoacidophilic, cell wall-less archaeon in the order thermoplasmatales, isolated from a solfataric soil in hakone, japan. | a novel thermoacidophilic, cell wall-less archaeon, strain ic-189t, was isolated from a solfataric field in ohwaku-dani, hakone, japan. the cells were irregular cocci, sometimes lobed, club-shaped or catenated, and were highly variable in size, ranging from 0.8 to 8.0 microm in diameter. the strain grew at temperatures in the range 38-68 degrees c (optimally at 60 degrees c) and at ph 1.8-4.0 (optimally at around ph 3.0). strain ic-189t was obligately aerobic and heterotrophic, requiring yeast e ... | 2007 | 17978217 |
| archaeal alcohol dehydrogenase active at increased temperatures and in the presence of organic solvents. | the adha gene of the extreme thermoacidophilic archaeon picrophilus torridus was identified by the means of genome analysis and was subsequently cloned in escherichia coli. pto 0846, encoding adha, consists of 954 bp corresponding to 317 aa. sequence comparison revealed that the novel biocatalyst has a low sequence identity (<26%) to previously characterized enzymes. the recombinant alcohol dehydrogenase was purified using hydroxyapatite, and alcohol oxidative activity of the purified adha was m ... | 2008 | 17989975 |
| crystal structure and properties of cyp231a2 from the thermoacidophilic archaeon picrophilus torridus. | the crystal structure of a cytochrome p450 from the thermoacidophile picrophilus torridus, cyp231a2 (pto1399), has been solved. this structure reveals a wide open substrate access channel. to better understand ligand-induced structural transitions in cyp231a2, protein-ligand interactions were investigated using 4-phenylimidazole. comparison of the ligand-free and -bound cyp231a2 structures shows conformational changes where the f and g helices swing as a single rigid body about a pivot point at ... | 2008 | 18197710 |
| extremely thermostable esterases from the thermoacidophilic euryarchaeon picrophilus torridus. | two genes encoding esterases esta and estb of picrophilus torridus were identified by the means of genome analysis and were subsequently cloned in escherichia coli. pto 0988, which is encoding esta, consists of 579 bp, whereas pto 1141, encoding estb, is composed of 696 bp, corresponding to 192 aa and 231 aa, respectively. sequence comparison revealed that both biocatalysts have low sequence identities (14 and 16%) compared to previously characterized enzymes. detailed analysis suggests that est ... | 2008 | 18330499 |
| acidiplasma aeolicum gen. nov., sp. nov., a euryarchaeon of the family ferroplasmaceae isolated from a hydrothermal pool, and transfer of ferroplasma cupricumulans to acidiplasma cupricumulans comb. nov. | a novel acidophilic, cell-wall-less archaeon, strain v(t), was isolated from a hydrothermal pool on vulcano island, italy. the morphology of cells was observed to vary from pleomorphic to coccoid. the temperature range for growth of strain v(t) was 15-65 degrees c with an optimum at 45 degrees c. the ph for growth ranged from ph 0 to 4 with an optimal at ph 1.4-1.6. strain v(t) was able to grow aerobically and anaerobically, oxidizing ferrous iron and reducing ferric iron, respectively. the isol ... | 2009 | 19628615 |
| pantothenate kinase from the thermoacidophilic archaeon picrophilus torridus. | pantothenate kinase (coaa) catalyzes the first step of the coenzyme a (coa) biosynthetic pathway and controls the intracellular concentrations of coa through feedback inhibition in bacteria. an alternative enzyme found in archaea, pantoate kinase, is missing in the order thermoplasmatales. the pto0232 gene from picrophilus torridus, a thermoacidophilic euryarchaeon, is shown to be a distant homologue of the prokaryotic type i coaa. the cloned gene clearly complements the poor growth of the tempe ... | 2010 | 19854913 |
| the nonphosphorylative entner-doudoroff pathway in the thermoacidophilic euryarchaeon picrophilus torridus involves a novel 2-keto-3-deoxygluconate- specific aldolase. | the pathway of glucose degradation in the thermoacidophilic euryarchaeon picrophilus torridus has been studied by in vivo labeling experiments and enzyme analyses. after growth of p. torridus in the presence of [1-(13)c]- and [3-(13)c]glucose, the label was found only in the c-1 and c-3 positions, respectively, of the proteinogenic amino acid alanine, indicating the exclusive operation of an entner-doudoroff (ed)-type pathway in vivo. cell extracts of p. torridus contained all enzyme activities ... | 2010 | 20023024 |
| simultaneous production of trehalose, bioethanol, and high-protein product from rice by an enzymatic process. | rice is a starch-rich raw material that can be used for trehalose production. it can be hydrolyzed with alpha-amylase, beta-amylase, and pullulanase to produce high-maltose content of rice saccharified solution for bioconversion of maltose into trehalose by trehalose synthase (tsase). for this purpose, an efficient enzymatic procedure has been successfully developed to simultaneously produce value-added trehalose, bioethanol, and high-protein product from rice as substrate. the highest maltose y ... | 2010 | 20131789 |
| characterization of plasmid ppo1 from the hyperacidophile picrophilus oshimae. | picrophilus oshimae and picrophilus torridus are free-living, moderately thermophilic and acidophilic organisms from the lineage of euryarchaeota. with a ph optimum of growth at ph 0.7 and the ability to even withstand molar concentrations of sulphuric acid, these organisms represent the most extreme acidophiles known. so far, nothing is known about plasmid biology in these hyperacidophiles. also, there are no genetic tools available for this genus. we have mobilized the 7.6 kbp plasmid from p. ... | 2011 | 21941462 |
| proteomic analysis of the extremely thermoacidophilic archaeon picrophilus torridus at ph and temperature values close to its growth limit. | the thermoacidophilic archaeon picrophilus torridus belongs to the thermoplasmatales order and is the most acidophilic organism known to date, growing under extremely acidic conditions around ph 0 (ph(opt) 1) and simultaneously at high temperatures up to 65°c. some genome features that may be responsible for survival under these harsh conditions have been concluded from the analysis of its 1.55 megabase genome sequence. a proteomic map was generated for p. torridus cells grown to the mid-exponen ... | 2011 | 22114103 |