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Charlotte Guyomar - One of the best experts on this subject based on the ideXlab platform.

  • genomic and physiological analysis reveals versatile metabolic capacity of deep sea Photobacterium phosphoreum ant 2200
    Extremophiles, 2016
    Co-Authors: Clairelise Santini, Sophie Mangenot, Charlotte Guyomar, Shengda Zhang, Valerie Barbe, Weijia Zhang
    Abstract:

    Bacteria of the genus Photobacterium thrive worldwide in oceans and show substantial eco-physiological diversity including free-living, symbiotic and piezophilic life styles. Genomic characteristics underlying this variability across species are poorly understood. Here we carried out genomic and physiological analysis of Photobacterium phosphoreum strain ANT-2200, the first deep-sea luminous bacterium of which the genome has been sequenced. Using optical mapping we updated the genomic data and reassembled it into two chromosomes and a large plasmid. Genomic analysis revealed a versatile energy metabolic potential and physiological analysis confirmed its growth capacity by deriving energy from fermentation of glucose or maltose, by respiration with formate as electron donor and trimethlyamine N-oxide (TMAO), nitrate or fumarate as electron acceptors, or by chemo-organo-heterotrophic growth in rich media. Despite that it was isolated at a site with saturated dissolved oxygen, the ANT-2200 strain possesses four gene clusters coding for typical anaerobic enzymes, the TMAO reductases. Elevated hydrostatic pressure enhances the TMAO reductase activity, mainly due to the increase of isoenzyme TorA1. The high copy number of the TMAO reductase isoenzymes and pressure-enhanced activity might imply a strategy developed by bacteria to adapt to deep-sea habitats where the instant TMAO availability may increase with depth.

  • genomic and physiological analysis reveals versatile metabolic capacity of deep sea Photobacterium phosphoreum ant 2200
    Extremophiles, 2016
    Co-Authors: Clairelise Santini, Sophie Mangenot, Charlotte Guyomar, Shengda Zhang, Valerie Barbe, Weijia Zhang
    Abstract:

    Bacteria of the genus Photobacterium thrive worldwide in oceans and show substantial eco-physiological diversity including free-living, symbiotic and piezophilic life styles. Genomic characteristics underlying this variability across species are poorly understood. Here we carried out genomic and physiological analysis of Photobacterium phosphoreum strain ANT-2200, the first deep-sea luminous bacterium of which the genome has been sequenced. Using optical mapping we updated the genomic data and reassembled it into two chromosomes and a large plasmid. Genomic analysis revealed a versatile energy metabolic potential and physiological analysis confirmed its growth capacity by deriving energy from fermentation of glucose or maltose, by respiration with formate as electron donor and trimethlyamine N-oxide (TMAO), nitrate or fumarate as electron acceptors, or by chemo-organo-heterotrophic growth in rich media. Despite that it was isolated at a site with saturated dissolved oxygen, the ANT-2200 strain possesses four gene clusters coding for typical anaerobic enzymes, the TMAO reductases. Elevated hydrostatic pressure enhances the TMAO reductase activity, mainly due to the increase of isoenzyme TorA1. The high copy number of the TMAO reductase isoenzymes and pressure-enhanced activity might imply a strategy developed by bacteria to adapt to deep-sea habitats where the instant TMAO availability may increase with depth.

Shengda Zhang - One of the best experts on this subject based on the ideXlab platform.

  • genomic and physiological analysis reveals versatile metabolic capacity of deep sea Photobacterium phosphoreum ant 2200
    Extremophiles, 2016
    Co-Authors: Clairelise Santini, Sophie Mangenot, Charlotte Guyomar, Shengda Zhang, Valerie Barbe, Weijia Zhang
    Abstract:

    Bacteria of the genus Photobacterium thrive worldwide in oceans and show substantial eco-physiological diversity including free-living, symbiotic and piezophilic life styles. Genomic characteristics underlying this variability across species are poorly understood. Here we carried out genomic and physiological analysis of Photobacterium phosphoreum strain ANT-2200, the first deep-sea luminous bacterium of which the genome has been sequenced. Using optical mapping we updated the genomic data and reassembled it into two chromosomes and a large plasmid. Genomic analysis revealed a versatile energy metabolic potential and physiological analysis confirmed its growth capacity by deriving energy from fermentation of glucose or maltose, by respiration with formate as electron donor and trimethlyamine N-oxide (TMAO), nitrate or fumarate as electron acceptors, or by chemo-organo-heterotrophic growth in rich media. Despite that it was isolated at a site with saturated dissolved oxygen, the ANT-2200 strain possesses four gene clusters coding for typical anaerobic enzymes, the TMAO reductases. Elevated hydrostatic pressure enhances the TMAO reductase activity, mainly due to the increase of isoenzyme TorA1. The high copy number of the TMAO reductase isoenzymes and pressure-enhanced activity might imply a strategy developed by bacteria to adapt to deep-sea habitats where the instant TMAO availability may increase with depth.

  • genomic and physiological analysis reveals versatile metabolic capacity of deep sea Photobacterium phosphoreum ant 2200
    Extremophiles, 2016
    Co-Authors: Clairelise Santini, Sophie Mangenot, Charlotte Guyomar, Shengda Zhang, Valerie Barbe, Weijia Zhang
    Abstract:

    Bacteria of the genus Photobacterium thrive worldwide in oceans and show substantial eco-physiological diversity including free-living, symbiotic and piezophilic life styles. Genomic characteristics underlying this variability across species are poorly understood. Here we carried out genomic and physiological analysis of Photobacterium phosphoreum strain ANT-2200, the first deep-sea luminous bacterium of which the genome has been sequenced. Using optical mapping we updated the genomic data and reassembled it into two chromosomes and a large plasmid. Genomic analysis revealed a versatile energy metabolic potential and physiological analysis confirmed its growth capacity by deriving energy from fermentation of glucose or maltose, by respiration with formate as electron donor and trimethlyamine N-oxide (TMAO), nitrate or fumarate as electron acceptors, or by chemo-organo-heterotrophic growth in rich media. Despite that it was isolated at a site with saturated dissolved oxygen, the ANT-2200 strain possesses four gene clusters coding for typical anaerobic enzymes, the TMAO reductases. Elevated hydrostatic pressure enhances the TMAO reductase activity, mainly due to the increase of isoenzyme TorA1. The high copy number of the TMAO reductase isoenzymes and pressure-enhanced activity might imply a strategy developed by bacteria to adapt to deep-sea habitats where the instant TMAO availability may increase with depth.

Clairelise Santini - One of the best experts on this subject based on the ideXlab platform.

  • genomic and physiological analysis reveals versatile metabolic capacity of deep sea Photobacterium phosphoreum ant 2200
    Extremophiles, 2016
    Co-Authors: Clairelise Santini, Sophie Mangenot, Charlotte Guyomar, Shengda Zhang, Valerie Barbe, Weijia Zhang
    Abstract:

    Bacteria of the genus Photobacterium thrive worldwide in oceans and show substantial eco-physiological diversity including free-living, symbiotic and piezophilic life styles. Genomic characteristics underlying this variability across species are poorly understood. Here we carried out genomic and physiological analysis of Photobacterium phosphoreum strain ANT-2200, the first deep-sea luminous bacterium of which the genome has been sequenced. Using optical mapping we updated the genomic data and reassembled it into two chromosomes and a large plasmid. Genomic analysis revealed a versatile energy metabolic potential and physiological analysis confirmed its growth capacity by deriving energy from fermentation of glucose or maltose, by respiration with formate as electron donor and trimethlyamine N-oxide (TMAO), nitrate or fumarate as electron acceptors, or by chemo-organo-heterotrophic growth in rich media. Despite that it was isolated at a site with saturated dissolved oxygen, the ANT-2200 strain possesses four gene clusters coding for typical anaerobic enzymes, the TMAO reductases. Elevated hydrostatic pressure enhances the TMAO reductase activity, mainly due to the increase of isoenzyme TorA1. The high copy number of the TMAO reductase isoenzymes and pressure-enhanced activity might imply a strategy developed by bacteria to adapt to deep-sea habitats where the instant TMAO availability may increase with depth.

  • genomic and physiological analysis reveals versatile metabolic capacity of deep sea Photobacterium phosphoreum ant 2200
    Extremophiles, 2016
    Co-Authors: Clairelise Santini, Sophie Mangenot, Charlotte Guyomar, Shengda Zhang, Valerie Barbe, Weijia Zhang
    Abstract:

    Bacteria of the genus Photobacterium thrive worldwide in oceans and show substantial eco-physiological diversity including free-living, symbiotic and piezophilic life styles. Genomic characteristics underlying this variability across species are poorly understood. Here we carried out genomic and physiological analysis of Photobacterium phosphoreum strain ANT-2200, the first deep-sea luminous bacterium of which the genome has been sequenced. Using optical mapping we updated the genomic data and reassembled it into two chromosomes and a large plasmid. Genomic analysis revealed a versatile energy metabolic potential and physiological analysis confirmed its growth capacity by deriving energy from fermentation of glucose or maltose, by respiration with formate as electron donor and trimethlyamine N-oxide (TMAO), nitrate or fumarate as electron acceptors, or by chemo-organo-heterotrophic growth in rich media. Despite that it was isolated at a site with saturated dissolved oxygen, the ANT-2200 strain possesses four gene clusters coding for typical anaerobic enzymes, the TMAO reductases. Elevated hydrostatic pressure enhances the TMAO reductase activity, mainly due to the increase of isoenzyme TorA1. The high copy number of the TMAO reductase isoenzymes and pressure-enhanced activity might imply a strategy developed by bacteria to adapt to deep-sea habitats where the instant TMAO availability may increase with depth.

Weijia Zhang - One of the best experts on this subject based on the ideXlab platform.

  • genomic and physiological analysis reveals versatile metabolic capacity of deep sea Photobacterium phosphoreum ant 2200
    Extremophiles, 2016
    Co-Authors: Clairelise Santini, Sophie Mangenot, Charlotte Guyomar, Shengda Zhang, Valerie Barbe, Weijia Zhang
    Abstract:

    Bacteria of the genus Photobacterium thrive worldwide in oceans and show substantial eco-physiological diversity including free-living, symbiotic and piezophilic life styles. Genomic characteristics underlying this variability across species are poorly understood. Here we carried out genomic and physiological analysis of Photobacterium phosphoreum strain ANT-2200, the first deep-sea luminous bacterium of which the genome has been sequenced. Using optical mapping we updated the genomic data and reassembled it into two chromosomes and a large plasmid. Genomic analysis revealed a versatile energy metabolic potential and physiological analysis confirmed its growth capacity by deriving energy from fermentation of glucose or maltose, by respiration with formate as electron donor and trimethlyamine N-oxide (TMAO), nitrate or fumarate as electron acceptors, or by chemo-organo-heterotrophic growth in rich media. Despite that it was isolated at a site with saturated dissolved oxygen, the ANT-2200 strain possesses four gene clusters coding for typical anaerobic enzymes, the TMAO reductases. Elevated hydrostatic pressure enhances the TMAO reductase activity, mainly due to the increase of isoenzyme TorA1. The high copy number of the TMAO reductase isoenzymes and pressure-enhanced activity might imply a strategy developed by bacteria to adapt to deep-sea habitats where the instant TMAO availability may increase with depth.

  • genomic and physiological analysis reveals versatile metabolic capacity of deep sea Photobacterium phosphoreum ant 2200
    Extremophiles, 2016
    Co-Authors: Clairelise Santini, Sophie Mangenot, Charlotte Guyomar, Shengda Zhang, Valerie Barbe, Weijia Zhang
    Abstract:

    Bacteria of the genus Photobacterium thrive worldwide in oceans and show substantial eco-physiological diversity including free-living, symbiotic and piezophilic life styles. Genomic characteristics underlying this variability across species are poorly understood. Here we carried out genomic and physiological analysis of Photobacterium phosphoreum strain ANT-2200, the first deep-sea luminous bacterium of which the genome has been sequenced. Using optical mapping we updated the genomic data and reassembled it into two chromosomes and a large plasmid. Genomic analysis revealed a versatile energy metabolic potential and physiological analysis confirmed its growth capacity by deriving energy from fermentation of glucose or maltose, by respiration with formate as electron donor and trimethlyamine N-oxide (TMAO), nitrate or fumarate as electron acceptors, or by chemo-organo-heterotrophic growth in rich media. Despite that it was isolated at a site with saturated dissolved oxygen, the ANT-2200 strain possesses four gene clusters coding for typical anaerobic enzymes, the TMAO reductases. Elevated hydrostatic pressure enhances the TMAO reductase activity, mainly due to the increase of isoenzyme TorA1. The high copy number of the TMAO reductase isoenzymes and pressure-enhanced activity might imply a strategy developed by bacteria to adapt to deep-sea habitats where the instant TMAO availability may increase with depth.

Paw Dalgaard - One of the best experts on this subject based on the ideXlab platform.

  • effect of pomegranate punica granutum and rosemary rosmarinus officinalis l extracts on shelf life for chilled greenland halibut reinhardtius hippoglossoides fillets in modified atmosphere packaging at 2 oc
    International Food Congress Novel Approaches In Food Industry, 2011
    Co-Authors: U Unalan, Paw Dalgaard, F Korel
    Abstract:

    The present study evaluated the effect of pomegranate extract (1% v/w) and rosemary extract (1% v/w) as natural preservatives as well as their combination (1% v/w) on shelf life extension of previously frozen and chilled Greenland halibut fillets in modified atmosphere packaging (MAP, 40%CO2/60%N2) at 2 °C. Parameters that were monitored were: microbiological (aerobic plate counts (APC), lactic acid bacteria (LAB), Lactobacillus spp., and Photobacterium phosphoreum), biochemical (pH, thio-barbituric acid (TBA), trimethylamine (TMA) and total-volatile-nitrogen (TVN)), and sensory (color, flavor and texture) attributes. For microbiological results, irrespective of treatments, APC reached levels �10 7 CFU/g during storage. The spoilage microflora of fillets in MAP was dominated by LAB, but the concentration of Lactobacillus was very low. During storage, P.phosphoreum was not detected in any sample. Among the chemical indices examined, TBA values of control samples exceeded the limit of 2 mg malondialdehyde (MDA)/kg (2.78 and 4.08 mg MDA/kg) on days 18 and 23 of storage, respectively, while TBA values for samples treated with extracts remained below the limit throughout the storage period. Final (TMA) and (TVN) values for all treatments ranged between 0.15 to 0.37 mg N/100 g and 16.90 to 24.10 mg N/100 g after 23 days of storage, respectively, not exceeding upper acceptability limit set by EU. Sensory analysis correlated well with TMA and TVN analysis, indicating a shelf life of longer than 23 days for all samples. The research was supported by the Federation of European Microbiological Societies (FEMS) and

  • biogenic amine formation and microbial spoilage in chilled garfish belone belone belone effect of modified atmosphere packaging and previous frozen storage
    Journal of Applied Microbiology, 2006
    Co-Authors: Paw Dalgaard, H L Madsen, N Samieian, J Emborg
    Abstract:

    AIMS: To evaluate biogenic amine formation and microbial spoilage in fresh and thawed chilled garfish. METHODS AND RESULTS: Storage trials were carried out with fresh and thawed garfish fillets at 0 or 5 degrees C in air or in modified atmosphere packaging (MAP: 40% CO2 and 60% N2). During storage, sensory, chemical and microbial changes were recorded and histamine formation by isolates from the spoilage microflora was evaluated at 5 degrees C. Photobacterium phosphoreum was responsible for histamine formation (>1000 ppm) in chilled fresh garfish. The use of MAP did not reduce the histamine formation. Strongly histamine-producing P. phosphoreum isolates formed 2080-4490 ppm at 5 degrees C, whereas below 60 ppm was formed by other P. phosphoreum isolates. Frozen storage inactivated P. phosphoreum and consequently reduced histamine formation in thawed garfish at 5 degrees C markedly. CONCLUSIONS: Photobacterium phosphoreum can produce above 1000 ppm of histamine in chilled fresh garfish stored both in air and in MAP. Freezing inactivates P. phosphoreum, extends shelf life and markedly reduces histamine formation in thawed MAP garfish during chilled storage. SIGNIFICANCE AND IMPACT OF THE STUDY: At 5 degrees C, more than 1000 ppm of histamine was formed in garfish; thus even when it is chilled this product represents a histamine fish-poisoning risk.

  • thawed chilled barents sea cod fillets in modified atmosphere packaging application of multivariate data analysis to select key parameters in good manufacturing practice
    Lwt - Food Science and Technology, 2002
    Co-Authors: Niels Boknaes, Kristina Nedenskov Jensen, Helle Skov Guldager, Carsten Osterberg, Jette Nielsen, Paw Dalgaard
    Abstract:

    Abstract The purpose of the present study was to select key parameters in good manufacturing practice for production of thawed chilled modified atmosphere packed (MAP) cod (Gadus morhua) fillets. The effect of frozen storage temperature (−20 and −30 °C), frozen storage period (3, 6, 9 and 12 mo) and chill storage periods up to 21 d at 2 °C were evaluated for thawed MAP Barents Sea cod fillets. Sensory, chemical, microbiological and physical quality attributes were evaluated and multivariate data analysis (principal component analysis and partial least-squares regression) applied for identification of key parameters in good manufacturing practice for this product. Frozen storage of up to 12 mo had no significant effect on quality attributes and shelf-life at 2 °C was above 14 d irrespective of the time of frozen storage. As compared to a previous study with Baltic Sea, cod drip losses during chill storage was low for thawed MAP Barents Sea cod and this fish raw material seemed the more appropriate for production of thawed chilled MAP products. Frozen storage inactivation of the spoilage bacteria of Photobacterium phosphoreum was modest in Barents Sea cod, possibly due to high trimethylamine oxide (TMAO) and NaCl contents.

  • antimicrobial effect of essential oils on the seafood spoilage micro organism Photobacterium phosphoreum in liquid media and fish products
    Letters in Applied Microbiology, 2002
    Co-Authors: Ole Mejlholm, Paw Dalgaard
    Abstract:

    Aims: To evaluate the antimicrobial effect of nine essential oils (EO) on P. phosphoreum and determine the effect of oregano oil on the shelf-life of modified atmosphere-packed (MAP) cod fillets. Methods and Results: The antimicrobial effect of EO was studied in a liquid medium and in product storage trials. Oils of oregano and cinnamon had strongest antimicrobial activity, followed by lemongrass, thyme, clove, bay, marjoram, sage and basil oils. Oregano oil (0·05%, v/w) reduced growth of P. phosphoreum in naturally contaminated MAP cod fillets and extended shelf-life from 11–12 d to 21–26 d at 2°C. Conclusions: Oregano oil reduced the growth of P. phosphoreum and extended the shelf-life of MAP cod fillets. Significance and Impact of the Study: Mild and natural preservation using EO can extend the shelf-life of MAP seafood through inhibiting the specific spoilage organism P. phosphoreum.

  • the effect of biogenic amine production by single bacterial cultures and metabiosis on cold smoked salmon
    Journal of Applied Microbiology, 2000
    Co-Authors: Lasse Vigel Jorgensen, Hans Henrik Huss, Paw Dalgaard
    Abstract:

    Aim: Biogenic amines are important indicators of spoilage in vacuum-packed cold-smoked salmon. It is the aim of this study to identify bacteria responsible for biogenic amine production in cold-smoked salmon. Methods and Results: The present study identified spoilage microflora from cold-smoked salmon and determined biogenic amine production of single and co-cultures growing in cold-smoked salmon. Photobacterium phosphoreum was the only species that produced histamine when inoculated on sterile cold-smoked salmon. Production of putrescine was enhanced 10–15 times when cultures of Serratia liquefaciens or Hafnia alvei were grown with Carnobacterium divergens or Lactobacillus sakei subsp. carnosus. This phenomenon was explained by interspecies microbial metabolism of arginine, i.e., metabiosis. Conclusions: The amounts of biogenic amines produced by single and co-cultures corresponded to those observed during spoilage of naturally-contaminated cold-smoked salmon. Photobacterium phosphoreum and Lact. curvatus were identified as the specific spoilage organisms in cold-smoked salmon. Significance and Impact of the Study: Determination of the specific spoilage organism is needed before a model can be developed for shelf-life predictions of cold-smoked salmon.