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Jody W Deming - One of the best experts on this subject based on the ideXlab platform.

  • Persistence of bacterial and archaeal communities in sea ice through an Arctic winter. Environ
    2016
    Co-Authors: Eric R. Collins, Gabrielle Rocap, Jody W Deming
    Abstract:

    The structure of bacterial communities in first-year spring and summer sea ice differs from that in source seawaters, suggesting selection during ice formation in autumn or taxon-specific mortality in the ice during winter. We tested these hypotheses by weekly sam-pling (January–March 2004) of first-year winter sea ice (Franklin Bay, Western Arctic) that experienced tem-peratures from-9°C to-26°C, generating community fingerprints and clone libraries for Bacteria and Archaea. Despite severe conditions and significant decreases in microbial abundance, no significant changes in richness or community structure were detected in the ice. Communities of Bacteria and Archaea in the ice, as in under-ice seawater, were dominated by SAR11 clade Alphaproteobacteria and Marine Group I Crenarchaeota, neither of which is known from later season sea ice. The bacterial ice library contained clones of Gammaproteobacteria from oligotrophic seawater clades (e.g. OM60, OM182) but no clones from gammaproteobacterial genera commonly detected in later season sea ice by similar methods (e.g. Colwellia, Psychrobacter). The only common sea ice bacterial genus detected in winter ice was Polaribacter. Overall, selection during ice forma-tion and mortality during winter appear to play minor roles in the process of microbial succession that leads to distinctive spring and summer sea ice communities

  • a unique capsular polysaccharide structure from the psychrophilic marine bacterium Colwellia psychrerythraea 34h that mimics antifreeze glyco proteins
    Journal of the American Chemical Society, 2015
    Co-Authors: Sara Carillo, Angela Casillo, Giuseppina Pieretti, Ermenegilda Parrilli, Filomena Sannino, Maddalena Bayergiraldi, Sandro Cosconati, Ettore Novellino, Marcela Ewert, Jody W Deming
    Abstract:

    The low temperatures of polar regions and high-altitude environments, especially icy habitats, present challenges for many microorganisms. Their ability to live under subfreezing conditions implies the production of compounds conferring cryotolerance. Colwellia psychrerythraea 34H, a γ-proteobacterium isolated from subzero Arctic marine sediments, provides a model for the study of life in cold environments. We report here the identification and detailed molecular primary and secondary structures of capsular polysaccharide from C. psychrerythraea 34H cells. The polymer was isolated in the water layer when cells were extracted by phenol/water and characterized by one- and two-dimensional NMR spectroscopy together with chemical analysis. Molecular mechanics and dynamics calculations were also performed. The polysaccharide consists of a tetrasaccharidic repeating unit containing two amino sugars and two uronic acids bearing threonine as substituent. The structural features of this unique polysaccharide resemble those present in antifreeze proteins and glycoproteins. These results suggest a possible correlation between the capsule structure and the ability of C. psychrerythraea to colonize subfreezing marine environments.

  • A unique capsular polysaccharide structure from the psy-chrophilic marine bacterium Colwellia psychrerythraea 34H that mimicks antifreeze (glyco) proteins
    'American Chemical Society (ACS)', 2015
    Co-Authors: Sara Carillo, Angela Casillo, Giuseppina Pieretti, Ermenegilda Parrilli, Filomena Sannino, Sandro Cosconati, Ettore Novellino, Marcela Ewert, Maddalena Bayer-giraldi, Jody W Deming
    Abstract:

    The low temperatures of polar regions and high-altitude environments, especially icy habitats, present challenges for many microorganisms. Their ability to live under subfreezing conditions implies the production of compounds conferring cryotolerance. Colwellia psychrerythraea 34H, a γ-proteobacterium isolated from subzero Arctic marine sediments, provides a model for the study of life in cold environments. We report here the identification and detailed molecular primary and secondary structures of capsular polysaccharide from C. psychrerythraea 34H cells. The polymer was isolated in the water layer when cells were extracted by phenol/water and characterized by one- and two-dimensional NMR spectroscopy together with chemical analysis. Molecular mechanics and dynamics calculations were also performed. The polysaccharide consists of a tetrasaccharidic repeating unit containing two amino sugars and two uronic acids bearing threonine as substituent. The structural features of this unique polysaccharide resemble those present in antifreeze proteins and glycoproteins. These results suggest a possible correlation between the capsule structure and the ability of C. psychrerythraea to colonize subfreezing marine environments

  • A Unique Capsular Polysaccharide Structure from the Psychrophilic Marine Bacterium Colwellia psychrerythraea 34H That Mimics Antifreeze (Glyco)proteins
    2015
    Co-Authors: Sara Carillo, Angela Casillo, Giuseppina Pieretti, Ermenegilda Parrilli, Filomena Sannino, Sandro Cosconati, Ettore Novellino, Marcela Ewert, Maddalena Bayer-giraldi, Jody W Deming
    Abstract:

    The low temperatures of polar regions and high-altitude environments, especially icy habitats, present challenges for many microorganisms. Their ability to live under subfreezing conditions implies the production of compounds conferring cryotolerance. Colwellia psychrerythraea 34H, a γ-proteobacterium isolated from subzero Arctic marine sediments, provides a model for the study of life in cold environments. We report here the identification and detailed molecular primary and secondary structures of capsular polysaccharide from C. psychrerythraea 34H cells. The polymer was isolated in the water layer when cells were extracted by phenol/water and characterized by one- and two-dimensional NMR spectroscopy together with chemical analysis. Molecular mechanics and dynamics calculations were also performed. The polysaccharide consists of a tetrasaccharidic repeating unit containing two amino sugars and two uronic acids bearing threonine as substituent. The structural features of this unique polysaccharide resemble those present in antifreeze proteins and glycoproteins. These results suggest a possible correlation between the capsule structure and the ability of C. psychrerythraea to colonize subfreezing marine environments

  • bacterial responses to fluctuations and extremes in temperature and brine salinity at the surface of arctic winter sea ice
    FEMS Microbiology Ecology, 2014
    Co-Authors: Marcela Ewert, Jody W Deming
    Abstract:

    Wintertime measurements near Barrow, Alaska, showed that bacteria near the surface of first-year sea ice and in overlying saline snow experience more extreme temperatures and salinities, and wider fluctuations in both parameters, than bacteria deeper in the ice. To examine impacts of such conditions on bacterial survival, two Arctic isolates with different environmental tolerances were subjected to winter-freezing conditions, with and without the presence of organic solutes involved in osmoprotection: proline, choline, or glycine betaine. Obligate psychrophile Colwellia psychrerythraea strain 34H suffered cell losses under all treatments, with maximal loss after 15-day exposure to temperatures fluctuating between −7 and −25 °C. Osmoprotectants significantly reduced the losses, implying that salinity rather than temperature extremes presents the greater stress for this organism. In contrast, psychrotolerant Psychrobacter sp. strain 7E underwent miniaturization and fragmentation under both fluctuating and stable-freezing conditions, with cell numbers increasing in most cases, implying a different survival strategy that may include enhanced dispersal. Thus, the composition and abundance of the bacterial community that survives in winter sea ice may depend on the extent to which overlying snow buffers against extreme temperature and salinity conditions and on the availability of solutes that mitigate osmotic shock, especially during melting.

Yasuhiro Takada - One of the best experts on this subject based on the ideXlab platform.

  • Characterization of NADP(+)-dependent isocitrate dehydrogenase isozymes from a psychrophilic bacterium, Colwellia psychrerythraea strain 34H.
    Bioscience biotechnology and biochemistry, 2016
    Co-Authors: Kaori Suzuki, Yasuhiro Takada
    Abstract:

    NADP+-dependent isocitrate dehydrogenase (IDH) isozymes of a psychrophilic bacterium, Colwellia psychrerythraea strain 34H, were characterized. The coexistence of monomeric and homodimeric IDHs in this bacterium was confirmed by Western blot analysis, the genes encoding two monomeric (IDH-IIa and IDH-IIb) and one dimeric (IDH-I) IDHs were cloned and overexpressed in Escherichia coli, and the three IDH proteins were purified. Both of the purified IDH-IIa and IDH-IIb were found to be cold-adapted enzymes while the purified IDH-I showed mesophilic properties. However, the specific activities of IDH-IIa and IDH-IIb were lower even at low temperatures than that of IDH-I. Therefore, IDH-I was suggested to be important for the growth of this bacterium. The results of colony formation of E. coli transformants carrying the respective IDH genes and IDH activities in their crude extracts indicated that the expression of the IDH-IIa gene is cold-inducible in the E. coli cells.

  • characterization of nadp dependent isocitrate dehydrogenase isozymes from a psychrophilic bacterium Colwellia psychrerythraea strain 34h
    Bioscience Biotechnology and Biochemistry, 2016
    Co-Authors: Kaori Suzuki, Yasuhiro Takada
    Abstract:

    NADP+-dependent isocitrate dehydrogenase (IDH) isozymes of a psychrophilic bacterium, Colwellia psychrerythraea strain 34H, were characterized. The coexistence of monomeric and homodimeric IDHs in this bacterium was confirmed by Western blot analysis, the genes encoding two monomeric (IDH-IIa and IDH-IIb) and one dimeric (IDH-I) IDHs were cloned and overexpressed in Escherichia coli, and the three IDH proteins were purified. Both of the purified IDH-IIa and IDH-IIb were found to be cold-adapted enzymes while the purified IDH-I showed mesophilic properties. However, the specific activities of IDH-IIa and IDH-IIb were lower even at low temperatures than that of IDH-I. Therefore, IDH-I was suggested to be important for the growth of this bacterium. The results of colony formation of E. coli transformants carrying the respective IDH genes and IDH activities in their crude extracts indicated that the expression of the IDH-IIa gene is cold-inducible in the E. coli cells.

  • Effects of the combined substitutions of amino acid residues on thermal properties of cold-adapted monomeric isocitrate dehydrogenases from psychrophilic bacteria.
    Extremophiles : life under extreme conditions, 2014
    Co-Authors: Miyuki Kobayashi, Yasuhiro Takada
    Abstract:

    In the two cold-adapted monomeric isocitrate dehydrogenases from psychrophilic bacteria, Colwellia maris and Colwellia psychrerythraea (CmIDH and CpIDH, respectively), the combined substitutions of amino acid residues between the Leu693, Leu724 and Phe735 residues of CmIDH and the corresponding Phe693, Gln724 and Leu735 residues of CpIDH were introduced by site-directed mutagenesis. A double mutant of CmIDH substituted its Leu724 and Phe735 residues by the corresponding ones of CpIDH, CmL724Q/F735L, and the triple mutant of CpIDH, CpF693L/Q724L/L735F, showed the most decrease and increase of activity, respectively, of each wild-type and its all mutated enzymes. In the case of CmIDH, the substitutions of these three amino acid residues resulted in the decrease of catalytic activity and thermostability for activity, but the combined substitutions of amino acid residues did not necessarily exert additive effects on these properties. On the other hand, similar substitutions in CpIDH had quite opposite effects to CmIDH, and the effects of the combined substitutions were additive. All multiple mutants of CmIDH and CpIDH showed lower and higher catalytic efficiency (k(cat)/K(m)) values than the respective wild-type enzymes. Single and multiple mutations of the substituted amino acid residues in the CmIDH and CpIDH led to the increase and decrease of sensitivity to tryptic digestion, indicating that the stability of protein structure was decreased and increased by the mutations, respectively.

  • characterization of chimeric and mutated isocitrate lyases of a mesophilic nitrogen fixing bacterium azotobacter vinelandii and a psychrophilic bacterium Colwellia maris
    Bioscience Biotechnology and Biochemistry, 2014
    Co-Authors: Tomofumi Hayashi, Wataru Matsuzaki, Yasuhiro Takada
    Abstract:

    Chimeric enzymes between a cold-adapted isocitrate lyase (ICL) of a psychrophilic bacterium, Colwellia maris, (CmICL) and a mesophilic ICL of a nitrogen-fixing bacterium, Azotobacter vinelandii, (AvICL) were constructed by dividing the ICL genes into four regions of almost equal length and exchanging regions in various combinations. The chimeric ICL, which was replaced C-terminal region 4 of AvICL by the corresponding region of CmICL, showed much lower specific activity and lower optimum temperature and thermostability for activity than wild-type AvICL, indicating that region 4 is involved in its thermal properties. Furthermore, mutual substitution between the Met501 residue in region 4 of CmICL and the corresponding Ile504 residue of AvICL influenced the temperature dependence of their activities, suggesting that these amino acid residues are important to the respective mesophilic and cold-adapted properties of AvICL and CmICL.

  • analysis of the amino acid residues involved in the thermal properties of the monomeric isocitrate dehydrogenases of the psychrophilic bacterium Colwellia maris and the mesophilic bacterium azotobacter vinelandii
    Bioscience Biotechnology and Biochemistry, 2012
    Co-Authors: Takayuki Kurihara, Yasuhiro Takada
    Abstract:

    Cold-adapted monomeric isocitrate dehydrogenase of a psychrophilic bacterium, Colwellia maris, (CmIDH) showed a high degree of amino acid sequential identity (69.5%) to a mesophilic nitrogen-fixing...

Marcela Ewert - One of the best experts on this subject based on the ideXlab platform.

  • a unique capsular polysaccharide structure from the psychrophilic marine bacterium Colwellia psychrerythraea 34h that mimics antifreeze glyco proteins
    Journal of the American Chemical Society, 2015
    Co-Authors: Sara Carillo, Angela Casillo, Giuseppina Pieretti, Ermenegilda Parrilli, Filomena Sannino, Maddalena Bayergiraldi, Sandro Cosconati, Ettore Novellino, Marcela Ewert, Jody W Deming
    Abstract:

    The low temperatures of polar regions and high-altitude environments, especially icy habitats, present challenges for many microorganisms. Their ability to live under subfreezing conditions implies the production of compounds conferring cryotolerance. Colwellia psychrerythraea 34H, a γ-proteobacterium isolated from subzero Arctic marine sediments, provides a model for the study of life in cold environments. We report here the identification and detailed molecular primary and secondary structures of capsular polysaccharide from C. psychrerythraea 34H cells. The polymer was isolated in the water layer when cells were extracted by phenol/water and characterized by one- and two-dimensional NMR spectroscopy together with chemical analysis. Molecular mechanics and dynamics calculations were also performed. The polysaccharide consists of a tetrasaccharidic repeating unit containing two amino sugars and two uronic acids bearing threonine as substituent. The structural features of this unique polysaccharide resemble those present in antifreeze proteins and glycoproteins. These results suggest a possible correlation between the capsule structure and the ability of C. psychrerythraea to colonize subfreezing marine environments.

  • A unique capsular polysaccharide structure from the psy-chrophilic marine bacterium Colwellia psychrerythraea 34H that mimicks antifreeze (glyco) proteins
    'American Chemical Society (ACS)', 2015
    Co-Authors: Sara Carillo, Angela Casillo, Giuseppina Pieretti, Ermenegilda Parrilli, Filomena Sannino, Sandro Cosconati, Ettore Novellino, Marcela Ewert, Maddalena Bayer-giraldi, Jody W Deming
    Abstract:

    The low temperatures of polar regions and high-altitude environments, especially icy habitats, present challenges for many microorganisms. Their ability to live under subfreezing conditions implies the production of compounds conferring cryotolerance. Colwellia psychrerythraea 34H, a γ-proteobacterium isolated from subzero Arctic marine sediments, provides a model for the study of life in cold environments. We report here the identification and detailed molecular primary and secondary structures of capsular polysaccharide from C. psychrerythraea 34H cells. The polymer was isolated in the water layer when cells were extracted by phenol/water and characterized by one- and two-dimensional NMR spectroscopy together with chemical analysis. Molecular mechanics and dynamics calculations were also performed. The polysaccharide consists of a tetrasaccharidic repeating unit containing two amino sugars and two uronic acids bearing threonine as substituent. The structural features of this unique polysaccharide resemble those present in antifreeze proteins and glycoproteins. These results suggest a possible correlation between the capsule structure and the ability of C. psychrerythraea to colonize subfreezing marine environments

  • A Unique Capsular Polysaccharide Structure from the Psychrophilic Marine Bacterium Colwellia psychrerythraea 34H That Mimics Antifreeze (Glyco)proteins
    2015
    Co-Authors: Sara Carillo, Angela Casillo, Giuseppina Pieretti, Ermenegilda Parrilli, Filomena Sannino, Sandro Cosconati, Ettore Novellino, Marcela Ewert, Maddalena Bayer-giraldi, Jody W Deming
    Abstract:

    The low temperatures of polar regions and high-altitude environments, especially icy habitats, present challenges for many microorganisms. Their ability to live under subfreezing conditions implies the production of compounds conferring cryotolerance. Colwellia psychrerythraea 34H, a γ-proteobacterium isolated from subzero Arctic marine sediments, provides a model for the study of life in cold environments. We report here the identification and detailed molecular primary and secondary structures of capsular polysaccharide from C. psychrerythraea 34H cells. The polymer was isolated in the water layer when cells were extracted by phenol/water and characterized by one- and two-dimensional NMR spectroscopy together with chemical analysis. Molecular mechanics and dynamics calculations were also performed. The polysaccharide consists of a tetrasaccharidic repeating unit containing two amino sugars and two uronic acids bearing threonine as substituent. The structural features of this unique polysaccharide resemble those present in antifreeze proteins and glycoproteins. These results suggest a possible correlation between the capsule structure and the ability of C. psychrerythraea to colonize subfreezing marine environments

  • bacterial responses to fluctuations and extremes in temperature and brine salinity at the surface of arctic winter sea ice
    FEMS Microbiology Ecology, 2014
    Co-Authors: Marcela Ewert, Jody W Deming
    Abstract:

    Wintertime measurements near Barrow, Alaska, showed that bacteria near the surface of first-year sea ice and in overlying saline snow experience more extreme temperatures and salinities, and wider fluctuations in both parameters, than bacteria deeper in the ice. To examine impacts of such conditions on bacterial survival, two Arctic isolates with different environmental tolerances were subjected to winter-freezing conditions, with and without the presence of organic solutes involved in osmoprotection: proline, choline, or glycine betaine. Obligate psychrophile Colwellia psychrerythraea strain 34H suffered cell losses under all treatments, with maximal loss after 15-day exposure to temperatures fluctuating between −7 and −25 °C. Osmoprotectants significantly reduced the losses, implying that salinity rather than temperature extremes presents the greater stress for this organism. In contrast, psychrotolerant Psychrobacter sp. strain 7E underwent miniaturization and fragmentation under both fluctuating and stable-freezing conditions, with cell numbers increasing in most cases, implying a different survival strategy that may include enhanced dispersal. Thus, the composition and abundance of the bacterial community that survives in winter sea ice may depend on the extent to which overlying snow buffers against extreme temperature and salinity conditions and on the availability of solutes that mitigate osmotic shock, especially during melting.

  • selective retention in saline ice of extracellular polysaccharides produced by the cold adapted marine bacterium Colwellia psychrerythraea strain 34h
    Annals of Glaciology, 2011
    Co-Authors: Marcela Ewert, Jody W Deming
    Abstract:

    The retention of salts in laboratory-grown ice was compared to the retention of extracellular polysaccharide substances (EPS) produced by the cold-adapted marine gammaproteo- bacterium, Colwellia psychrerythraea strain 34H. Saline ice was formed, by means of a cold-finger apparatus, from artificial sea-water solutions containing either native dissolved EPS from strain 34H, the same EPS but heat-treated, or dissolved EPS from the uninoculated growth medium. Results indicated that only the native (unheated) EPS of strain 34H was retained preferentially in the ice. Temperature and volumetric measurements of the ice further suggested a link between the heat-labile fraction of this EPS of marine bacterial origin and potential habitat alteration. Bacterial EPS may join algal EPS in our understanding of how extracellular polymers help to establish and sustain the microbial community that inhabits sea ice.

Sara Carillo - One of the best experts on this subject based on the ideXlab platform.

  • a unique capsular polysaccharide structure from the psychrophilic marine bacterium Colwellia psychrerythraea 34h that mimics antifreeze glyco proteins
    Journal of the American Chemical Society, 2015
    Co-Authors: Sara Carillo, Angela Casillo, Giuseppina Pieretti, Ermenegilda Parrilli, Filomena Sannino, Maddalena Bayergiraldi, Sandro Cosconati, Ettore Novellino, Marcela Ewert, Jody W Deming
    Abstract:

    The low temperatures of polar regions and high-altitude environments, especially icy habitats, present challenges for many microorganisms. Their ability to live under subfreezing conditions implies the production of compounds conferring cryotolerance. Colwellia psychrerythraea 34H, a γ-proteobacterium isolated from subzero Arctic marine sediments, provides a model for the study of life in cold environments. We report here the identification and detailed molecular primary and secondary structures of capsular polysaccharide from C. psychrerythraea 34H cells. The polymer was isolated in the water layer when cells were extracted by phenol/water and characterized by one- and two-dimensional NMR spectroscopy together with chemical analysis. Molecular mechanics and dynamics calculations were also performed. The polysaccharide consists of a tetrasaccharidic repeating unit containing two amino sugars and two uronic acids bearing threonine as substituent. The structural features of this unique polysaccharide resemble those present in antifreeze proteins and glycoproteins. These results suggest a possible correlation between the capsule structure and the ability of C. psychrerythraea to colonize subfreezing marine environments.

  • A unique capsular polysaccharide structure from the psy-chrophilic marine bacterium Colwellia psychrerythraea 34H that mimicks antifreeze (glyco) proteins
    'American Chemical Society (ACS)', 2015
    Co-Authors: Sara Carillo, Angela Casillo, Giuseppina Pieretti, Ermenegilda Parrilli, Filomena Sannino, Sandro Cosconati, Ettore Novellino, Marcela Ewert, Maddalena Bayer-giraldi, Jody W Deming
    Abstract:

    The low temperatures of polar regions and high-altitude environments, especially icy habitats, present challenges for many microorganisms. Their ability to live under subfreezing conditions implies the production of compounds conferring cryotolerance. Colwellia psychrerythraea 34H, a γ-proteobacterium isolated from subzero Arctic marine sediments, provides a model for the study of life in cold environments. We report here the identification and detailed molecular primary and secondary structures of capsular polysaccharide from C. psychrerythraea 34H cells. The polymer was isolated in the water layer when cells were extracted by phenol/water and characterized by one- and two-dimensional NMR spectroscopy together with chemical analysis. Molecular mechanics and dynamics calculations were also performed. The polysaccharide consists of a tetrasaccharidic repeating unit containing two amino sugars and two uronic acids bearing threonine as substituent. The structural features of this unique polysaccharide resemble those present in antifreeze proteins and glycoproteins. These results suggest a possible correlation between the capsule structure and the ability of C. psychrerythraea to colonize subfreezing marine environments

  • A Unique Capsular Polysaccharide Structure from the Psychrophilic Marine Bacterium Colwellia psychrerythraea 34H That Mimics Antifreeze (Glyco)proteins
    2015
    Co-Authors: Sara Carillo, Angela Casillo, Giuseppina Pieretti, Ermenegilda Parrilli, Filomena Sannino, Sandro Cosconati, Ettore Novellino, Marcela Ewert, Maddalena Bayer-giraldi, Jody W Deming
    Abstract:

    The low temperatures of polar regions and high-altitude environments, especially icy habitats, present challenges for many microorganisms. Their ability to live under subfreezing conditions implies the production of compounds conferring cryotolerance. Colwellia psychrerythraea 34H, a γ-proteobacterium isolated from subzero Arctic marine sediments, provides a model for the study of life in cold environments. We report here the identification and detailed molecular primary and secondary structures of capsular polysaccharide from C. psychrerythraea 34H cells. The polymer was isolated in the water layer when cells were extracted by phenol/water and characterized by one- and two-dimensional NMR spectroscopy together with chemical analysis. Molecular mechanics and dynamics calculations were also performed. The polysaccharide consists of a tetrasaccharidic repeating unit containing two amino sugars and two uronic acids bearing threonine as substituent. The structural features of this unique polysaccharide resemble those present in antifreeze proteins and glycoproteins. These results suggest a possible correlation between the capsule structure and the ability of C. psychrerythraea to colonize subfreezing marine environments

  • structural characterization of the core oligosaccharide isolated from the lipo polysaccharide of the psychrophilic bacterium Colwellia psychrerythraea strain 34h
    European Journal of Organic Chemistry, 2013
    Co-Authors: Sara Carillo, Giuseppina Pieretti, Ermenegilda Parrilli, Sannino Filomena, Rosa Lanzetta, Michelangelo Parrilli, Buko Lindner, Maria Luisa Tutino, Maria Michela Corsaro
    Abstract:

    Cold-adapted bacteria are microorganisms that thrive at very low temperatures in permanently cold environments (0–10 °C). Their ability to survive under these harsh conditions is the result of molecular evolution and adaptations, which include the structural modification of the phospholipid membrane. To give insight into the role of the membrane in the mechanisms of adaptation to low temperature, the characterization of other cell-wall components is necessary. Among these components, the lipopolysaccharides are complex amphiphilic macromolecules embedded in the outer leaflet of the external membrane, of which they are the major constituents. The cold-adapted Colwellia psychrerythraea 34H bacterium, living in deep sea and Arctic and Antarctic sea ice, was cultivated at 4 °C. The lipooligosaccharide (LOS) was isolated and analysed by means of chemical analysis. Then it was degraded either by mild hydrazinolysis (O-deacylation) or hot KOH (4 M; N-deacylation). Both products were investigated in detail by 1H and 13C NMR spectroscopy and by ESI FT-ICR mass spectrometry. The oligosaccharide portion consists of a unique and very short species with the following general structure: α-L-Col-(12)-α-D-GalA-(12)-α-D-Man-[3-P-D-Gro]-(15)-α-D-Kdo-4-P-Lipid-A.

  • Structural Characterization of the Core Oligosaccharide Isolated from the Lipopolysaccharide of the Psychrophilic Bacterium Colwellia psychrerythraea strain 34H
    'Wiley', 2013
    Co-Authors: Sara Carillo, Buko Lindner, Maria Luisa Tutino, G. Pieretti, E. Parrilli, F. Sannino, R. Lanzetta, M. Parrilli, Maria Michela Corsaro
    Abstract:

    Cold-adapted bacteria are microorganisms that thrive at very low temperatures in permanently cold environments (0-10 degrees C). Their ability to survive under these harsh conditions is the result of molecular evolution and adaptations, which include the structural modification of the phospholipid membrane. To give insight into the role of the membrane in the mechanisms of adaptation to low temperature, the characterization of other cell-wall components is necessary. Among these components, the lipopolysaccharides are complex amphiphilic macromolecules embedded in the outer leaflet of the external membrane, of which they are the major constituents. The cold-adapted Colwellia psychrerythraea 34H bacterium, living in deep sea and Arctic and Antarctic sea ice, was cultivated at 4 degrees C. The lipooligosaccharide (LOS) was isolated and analysed by means of chemical analysis. Then it was degraded either by mild hydrazinolysis (O-deacylation) or hot KOH (4 M; N-deacylation). Both products were investigated in detail by 1H and 13C NMR spectroscopy and by ESI FT-ICR mass spectrometry. The oligosaccharide portion consists of a unique and very short species with the following general structure: -L-Col-(12)--D-GalA-(12)--D-Man-[3-P-D-Gro]-(15)--D-Kdo-4-P-Lipid-

Ermenegilda Parrilli - One of the best experts on this subject based on the ideXlab platform.

  • Structural characterization of an all-aminosugar-containing capsular polysaccharide from Colwellia psychrerythraea 34H
    Antonie van Leeuwenhoek, 2017
    Co-Authors: Angela Casillo, Giuseppina Pieretti, Ermenegilda Parrilli, Filomena Sannino, Jonas Ståhle, Daniel E. Mitchell, Matthew I. Gibson, Gennaro Marino, Rosa Lanzetta, Michelangelo Parrilli
    Abstract:

    Colwellia psychrerythraea strain 34H, a Gram-negative bacterium isolated from Arctic marine sediments, is considered a model to study the adaptation to cold environments. Recently, we demonstrated that C. psychrerythraea 34H produces two different extracellular polysaccharides, a capsular polysaccharide and a medium released polysaccharide, which confer cryoprotection to the bacterium. In this study, we report the structure of an additional capsular polysaccharide produced by Colwellia grown at a different temperature. The structure was determined using chemical methods, and one- and two-dimensional NMR spectroscopy. The results showed a trisaccharide repeating unit made up of only amino-sugar residues: N -acetyl-galactosamine, 2,4-diacetamido-2,4,6-trideoxy-glucose (bacillosamine), and 2-acetamido-2-deoxyglucuronic acid with the following structure: →4)-β- d -Glc p NAcA-(1 →3)-β- d -Qui p NAc4NAc-(1 →3)-β- d -Gal p NAc-(1 →. The 3D model, generated in accordance with ^1H,^1H-NOE NMR correlations and consisting of ten repeating units, shows a helical structure. In contrast with the other extracellular polysaccharides produced from Colwellia at 4 °C, this molecule displays only a low ice recrystallization inhibition activity.

  • structure activity relationship of the exopolysaccharide from a psychrophilic bacterium a strategy for cryoprotection
    Carbohydrate Polymers, 2017
    Co-Authors: Angela Casillo, Ermenegilda Parrilli, Filomena Sannino, Sandro Cosconati, Daniel E. Mitchell, Matthew I. Gibson, Gennaro Marino, Rosa Lanzetta, Michelangelo Parrilli, Ettore Novellino
    Abstract:

    Microrganisms from sea ice, glacial and subglacial environments are currently under investigation due to their relevant ecological functions in these habitats, and to their potential biotechnological applications. The cold-adapted Colwellia psychrerythraea 34H produces extracellular polysaccharides with cryoprotection activity. We here describe the purification and detailed molecular primary and secondary structure of the exopolysaccharide (EPS) secreted by C. psychrerythraea 34H cells grown at 4°C. The structure was determined by chemical analysis and NMR. The trisaccharide repeating unit of the EPS is constituted by a N-acetyl quinovosamine unit and two residues of galacturonic acid both decorated with alanine. In addition, the EPS was tested in vitro showing a significant inhibitory effect on ice recrystallization. In-depth NMR and computational analysis suggest a pseudohelicoidal structure which seems to prevent the local tetrahedral order of the water molecules in the first hydration shell, and could be responsible of the inhibition of ice recrystallization. As cell cryopreservation is an essential tool in modern biotechnology and medicine, the observations reported in this paper could pave the way for a biotechnological application of Colwellia EPS.

  • a unique capsular polysaccharide structure from the psychrophilic marine bacterium Colwellia psychrerythraea 34h that mimics antifreeze glyco proteins
    Journal of the American Chemical Society, 2015
    Co-Authors: Sara Carillo, Angela Casillo, Giuseppina Pieretti, Ermenegilda Parrilli, Filomena Sannino, Maddalena Bayergiraldi, Sandro Cosconati, Ettore Novellino, Marcela Ewert, Jody W Deming
    Abstract:

    The low temperatures of polar regions and high-altitude environments, especially icy habitats, present challenges for many microorganisms. Their ability to live under subfreezing conditions implies the production of compounds conferring cryotolerance. Colwellia psychrerythraea 34H, a γ-proteobacterium isolated from subzero Arctic marine sediments, provides a model for the study of life in cold environments. We report here the identification and detailed molecular primary and secondary structures of capsular polysaccharide from C. psychrerythraea 34H cells. The polymer was isolated in the water layer when cells were extracted by phenol/water and characterized by one- and two-dimensional NMR spectroscopy together with chemical analysis. Molecular mechanics and dynamics calculations were also performed. The polysaccharide consists of a tetrasaccharidic repeating unit containing two amino sugars and two uronic acids bearing threonine as substituent. The structural features of this unique polysaccharide resemble those present in antifreeze proteins and glycoproteins. These results suggest a possible correlation between the capsule structure and the ability of C. psychrerythraea to colonize subfreezing marine environments.

  • A unique capsular polysaccharide structure from the psy-chrophilic marine bacterium Colwellia psychrerythraea 34H that mimicks antifreeze (glyco) proteins
    'American Chemical Society (ACS)', 2015
    Co-Authors: Sara Carillo, Angela Casillo, Giuseppina Pieretti, Ermenegilda Parrilli, Filomena Sannino, Sandro Cosconati, Ettore Novellino, Marcela Ewert, Maddalena Bayer-giraldi, Jody W Deming
    Abstract:

    The low temperatures of polar regions and high-altitude environments, especially icy habitats, present challenges for many microorganisms. Their ability to live under subfreezing conditions implies the production of compounds conferring cryotolerance. Colwellia psychrerythraea 34H, a γ-proteobacterium isolated from subzero Arctic marine sediments, provides a model for the study of life in cold environments. We report here the identification and detailed molecular primary and secondary structures of capsular polysaccharide from C. psychrerythraea 34H cells. The polymer was isolated in the water layer when cells were extracted by phenol/water and characterized by one- and two-dimensional NMR spectroscopy together with chemical analysis. Molecular mechanics and dynamics calculations were also performed. The polysaccharide consists of a tetrasaccharidic repeating unit containing two amino sugars and two uronic acids bearing threonine as substituent. The structural features of this unique polysaccharide resemble those present in antifreeze proteins and glycoproteins. These results suggest a possible correlation between the capsule structure and the ability of C. psychrerythraea to colonize subfreezing marine environments

  • A Unique Capsular Polysaccharide Structure from the Psychrophilic Marine Bacterium Colwellia psychrerythraea 34H That Mimics Antifreeze (Glyco)proteins
    2015
    Co-Authors: Sara Carillo, Angela Casillo, Giuseppina Pieretti, Ermenegilda Parrilli, Filomena Sannino, Sandro Cosconati, Ettore Novellino, Marcela Ewert, Maddalena Bayer-giraldi, Jody W Deming
    Abstract:

    The low temperatures of polar regions and high-altitude environments, especially icy habitats, present challenges for many microorganisms. Their ability to live under subfreezing conditions implies the production of compounds conferring cryotolerance. Colwellia psychrerythraea 34H, a γ-proteobacterium isolated from subzero Arctic marine sediments, provides a model for the study of life in cold environments. We report here the identification and detailed molecular primary and secondary structures of capsular polysaccharide from C. psychrerythraea 34H cells. The polymer was isolated in the water layer when cells were extracted by phenol/water and characterized by one- and two-dimensional NMR spectroscopy together with chemical analysis. Molecular mechanics and dynamics calculations were also performed. The polysaccharide consists of a tetrasaccharidic repeating unit containing two amino sugars and two uronic acids bearing threonine as substituent. The structural features of this unique polysaccharide resemble those present in antifreeze proteins and glycoproteins. These results suggest a possible correlation between the capsule structure and the ability of C. psychrerythraea to colonize subfreezing marine environments