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E. A. Bonch-osmolovskaya - One of the best experts on this subject based on the ideXlab platform.

  • Capacity of hyperthermophilic Crenarchaeota for decomposition of refractory proteins (α- and β-keratins)
    Microbiology, 2014
    Co-Authors: S. Kh. Bidzhieva, Ilya V. Kublanov, K. S. Derbikova, E. A. Bonch-osmolovskaya
    Abstract:

    Anaerobic thermophilic archaea of the genera Thermogladius and Desulfurococcus capable of α- and β-keratin decomposition were isolated from hot springs of Kamchatka and Kunashir Island. For two of them (strains 2355k and 3008g), the presence of high-molecular mass, cell-bound endopeptidases active against nonhydrolyzed and partially hydrolyzed proteins at high values of temperature and pH was shown. Capacity for β-keratin decomposition was also found in collection strains (type strains of Desulfurococcus amylolyticus subsp. amylolyticus, D. mucosus subsp. mobilis, and D. fermentans).

  • Desulfurococcus kamchatkensis sp. nov., a novel hyperthermophilic protein-degrading archaeon isolated from a Kamchatka hot spring
    INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY, 2009
    Co-Authors: Ilya V. Kublanov, S. Kh. Bidjieva, Andrey V. Mardanov, E. A. Bonch-osmolovskaya
    Abstract:

    growth at pH 6.5 was 65–87 6C, with an optimum at 85 6C. The pH range for growth at 85 6C was 5.5–7.5, with an optimum at pH 6.5. Growth was not observed at or below 606 Co r at or above 90 6C, as well as at or below pH 5.0 and at or above pH 8.0. The isolate fermented a wide range of substrates including proteins: a-keratin, albumin and gelatin. Elemental sulfur was not essential for growth, but stimulated growth. Strain 1221n T synthesized 40 and 120 kDa proteinases localized on the cell envelope. The G+C content of the DNA was 44.4 mol%. Phylogenetic analysis based on 16S rRNA gene sequence comparison indicated that strain 1221n T was affiliated with the genus Desulfurococcus. The level of 16S rRNA gene sequence similarity with other Desulfurococcus species was 96.7–98.1%, and Desulfurococcus amylolyticus was found to be the most closely related organism. Based on the data from the phylogenetic analysis and the physiological properties of the novel isolate, strain 1221n T should be classified as representing a novel species, for which the name Desulfurococcus kamchatkensis sp. nov. is proposed. The type strain is 1221n T (5DSM 18924 T 5VKM B-2413 T ).

  • Desulfurococcus kamchatkensis sp. nov., a novel hyperthermophilic protein-degrading archaeon isolated from a Kamchatka hot spring.
    International journal of systematic and evolutionary microbiology, 2009
    Co-Authors: Ilya V. Kublanov, S. Kh. Bidjieva, Andrey V. Mardanov, E. A. Bonch-osmolovskaya
    Abstract:

    A novel obligately anaerobic, hyperthermophilic, organotrophic archaeon, designated strain 1221n(T), was isolated from a hot spring of Uzon Caldera (Kamchatka Peninsula, Russia). Cells of strain 1221n(T) were non-motile regular cocci, 0.6-1 mum in diameter. The temperature range for growth at pH 6.5 was 65-87 degrees C, with an optimum at 85 degrees C. The pH range for growth at 85 degrees C was 5.5-7.5, with an optimum at pH 6.5. Growth was not observed at or below 6 degrees C or at or above 90 degrees C, as well as at or below pH 5.0 and at or above pH 8.0. The isolate fermented a wide range of substrates including proteins: alpha-keratin, albumin and gelatin. Elemental sulfur was not essential for growth, but stimulated growth. Strain 1221n(T) synthesized 40 and 120 kDa proteinases localized on the cell envelope. The G+C content of the DNA was 44.4 mol%. Phylogenetic analysis based on 16S rRNA gene sequence comparison indicated that strain 1221n(T) was affiliated with the genus Desulfurococcus. The level of 16S rRNA gene sequence similarity with other Desulfurococcus species was 96.7-98.1 %, and Desulfurococcus amylolyticus was found to be the most closely related organism. Based on the data from the phylogenetic analysis and the physiological properties of the novel isolate, strain 1221n(T) should be classified as representing a novel species, for which the name Desulfurococcus kamchatkensis sp. nov. is proposed. The type strain is 1221n(T) (=DSM 18924(T)=VKM B-2413(T)).

  • Desulfurococcus fermentans sp. nov., a novel hyperthermophilic archaeon from a Kamchatka hot spring, and emended description of the genus Desulfurococcus.
    International Journal of Systematic and Evolutionary Microbiology, 2005
    Co-Authors: A A Perevalova, Ilya V. Kublanov, N. A. Chernyh, Tatyana P. Tourova, Boris B. Kuznetsov, V A Svetlichny, N A Kostrikina, E. A. Bonch-osmolovskaya
    Abstract:

    An obligately anaerobic, hyperthermophilic, organoheterotrophic archaeon, strain Z-1312T, was isolated from a freshwater hot spring of the Uzon caldera (Kamchatka Peninsula, Russia). The cells were regular cocci, 1–4 μm in diameter, with one long flagellum. The cell envelope was composed of a globular layer attached to the cytoplasmic membrane. The temperature range for growth was 63–89 °C, with an optimum between 80 and 82 °C. The pH range for growth at 80 °C was 4·8–6·8, with an optimum at pH 6·0. Strain Z-1312T grew by hydrolysis and/or fermentation of a wide range of polymeric and monomeric substrates, including agarose, amygdalin, arabinose, arbutin, casein hydrolysate, cellulose (filter paper, microcrystalline cellulose, carboxymethyl cellulose), dextran, dulcitol, fructose, lactose, laminarin, lichenan, maltose, pectin, peptone, ribose, starch and sucrose. No growth was detected on glucose, xylose, mannitol or sorbitol. Growth products when sucrose or starch were used as the substrate were acetate, H2 and CO2. Elemental sulfur, thiosulfate and nitrate added as potential electron acceptors for anaerobic respiration did not stimulate growth when tested with starch as the substrate. H2 at 100 % in the gas phase did not inhibit growth on starch or peptone. The G+C content of the DNA was 42·5 mol%. 16S rRNA gene sequence analysis placed the isolated strain Z-1312T as a member of the genus Desulfurococcus, where it represented a novel species, for which the name Desulfurococcus fermentans sp. nov. (type strain Z-1312T=DSM 16532 T=VKM V-2316T) is proposed.

  • Desulfurococcus fermentans sp. nov., a novel hyperthermophilic archaeon from a Kamchatka hot spring, and emended description of the genus Desulfurococcus.
    International journal of systematic and evolutionary microbiology, 2005
    Co-Authors: A A Perevalova, Ilya V. Kublanov, N. A. Chernyh, V A Svetlichny, N A Kostrikina, T P Tourova, B B Kuznetsov, E. A. Bonch-osmolovskaya
    Abstract:

    An obligately anaerobic, hyperthermophilic, organoheterotrophic archaeon, strain Z-1312(T), was isolated from a freshwater hot spring of the Uzon caldera (Kamchatka Peninsula, Russia). The cells were regular cocci, 1-4 microm in diameter, with one long flagellum. The cell envelope was composed of a globular layer attached to the cytoplasmic membrane. The temperature range for growth was 63-89 degrees C, with an optimum between 80 and 82 degrees C. The pH range for growth at 80 degrees C was 4.8-6.8, with an optimum at pH 6.0. Strain Z-1312(T) grew by hydrolysis and/or fermentation of a wide range of polymeric and monomeric substrates, including agarose, amygdalin, arabinose, arbutin, casein hydrolysate, cellulose (filter paper, microcrystalline cellulose, carboxymethyl cellulose), dextran, dulcitol, fructose, lactose, laminarin, lichenan, maltose, pectin, peptone, ribose, starch and sucrose. No growth was detected on glucose, xylose, mannitol or sorbitol. Growth products when sucrose or starch were used as the substrate were acetate, H(2) and CO(2). Elemental sulfur, thiosulfate and nitrate added as potential electron acceptors for anaerobic respiration did not stimulate growth when tested with starch as the substrate. H(2) at 100 % in the gas phase did not inhibit growth on starch or peptone. The G+C content of the DNA was 42.5 mol%. 16S rRNA gene sequence analysis placed the isolated strain Z-1312(T) as a member of the genus Desulfurococcus, where it represented a novel species, for which the name Desulfurococcus fermentans sp. nov. (type strain Z-1312(T) = DSM 16532 (T) = VKM V-2316(T)) is proposed.

Yasuo Kagawa - One of the best experts on this subject based on the ideXlab platform.

  • The Stabilizing Residues and the Functional Domains in the Hyperthermophilic V-ATPase ofDesulfurococcus
    Biochemical and biophysical research communications, 1997
    Co-Authors: Hirobumi Shibui, Masafumi Yohda, Toshiro Hamamoto, Yasuo Kagawa
    Abstract:

    To clarify a universal mechanism of the intramolecular rotation of ATP-synthase, an operon encoding a stable, ancestral ATPase was cloned from a heterotrophic archaeum Desulfurococcus strain SY. The operon of about 7 kbp contained genes E, C, G, A, B and D encoding subunits with predicted molecular weights of 23,217, 41,659, 11,499, 65,476, 52,295, and 24,897, respectively. The sequence was compared with that of Na-ATPase of Enterococcus hirae, A-ATPase of Halobacterium salinarium, V-ATPase of Methanosarcina mazei, and ATP synthase of Methanococcus jannaschii, which are homologous. (1) The cause of hyperthermostability: The main exchanges in the amino acid residues of hyperthermophilic proteins included Asp --> Glu (11 residues of A subunit of E.h.) and, Ser --> Ala. (2) The domains needed for the intramolecular rotation: The domains similar to those established in F-type ATPases were also found in the V-type ATPases of species with a different energy metabolism.

  • Gene for Aspartate Racemase from the Sulfur-dependent Hyperthermophilic Archaeum, Desulfurococcus Strain SY
    The Journal of biological chemistry, 1996
    Co-Authors: Masafumi Yohda, Tadashi Maruyama, Isao Endo, Yoriko Abe, Toshiko Ohta, Toshii Iida, Yasuo Kagawa
    Abstract:

    Abstract Amino acid racemases are ubiquitous throughout eubacteria. However, no amino acid racemases have yet been found in eukaryotes and archaea. We cloned a gene highly homologous to that for the aspartate racemase from the sulfur-dependent hyperthermophilic archaeum, Desulfurococcus strain SY. The product of the gene showed 35.2% amino acid sequence identity with the aspartate racemase of Streptococcus thermophilus IAM10064, and was also homologous to glutamate racemases around the putative catalytic cysteine residues. The encoded protein was expressed in Escherichia coli. The recombinant protein had amino acid racemizing activity, which was highly specific for aspartate and increased with temperature from 37°C to 90°C. Therefore, this was identified as the first hyperthermophilic archaeal amino acid racemase. A little aspartate racemizing activity was also detected in the crude extract of Desulfurococcus strain SY. The function of this aspartate racemase might be the uptake of D-aspartate formed at high temperature or the production of D-aspartate as a cell component. The fact that the amino acid racemases are distributed among both eubacteria and archaea suggests that endogenous D-amino acids in mammals are also synthesized by amino acid racemases.

  • Gene of Heat Shock Protein of Sulfur-Dependent Archaeal Hyperthermophile Desulfurococcus
    Biochemical and biophysical research communications, 1995
    Co-Authors: Yasuo Kagawa, Masafumi Yohda, Isao Endo, Yoriko Abe, Toshiko Ohta, Hitoshi Endo, Nobuko Kato, Toshiro Hamamoto, Masaru Ichida, Toshihiro Hoaki
    Abstract:

    Abstract To elucidate thermoresistance, a gene of a hyperthermophilic heat shock protein (HHSP) was isolated from the hyperthermophile Desulfurococcus strain SY which grows at 95°C. The molecular weight of HHSP deduced from the open reading frame was 59,137 (545 amino acid residues). Sequence alignments of peptides reveal similarities (evolutionary distances) to the α (0.279) and β (0.296) subunits of thermosome, TF55 (0.343) and human t-complex polypeptide 1. The structure of a thermophilic heat shock protein TGroEL (Tamada et al. (1991) Biochem. Biophys. Res. Commun.179, 565) was quite different from that of HHSP. TGroEL and HSP60 have sequences identical to HHSP at its equatorial domain, while those identical to the α subunit of F-type ATPase are at its apical domain.

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