The Experts below are selected from a list of 177 Experts worldwide ranked by ideXlab platform

G J Zylstra - One of the best experts on this subject based on the ideXlab platform.

  • Functional analysis of genes involved in biphenyl, naphthalene, phenanthrene, and m-xylene degradation by Sphingomonas yanoikuyae B1
    Journal of Industrial Microbiology and Biotechnology, 1999
    Co-Authors: E Kim, G J Zylstra
    Abstract:

    B1 is able to utilize toluene, m -xylene, p -xylene, biphenyl, naphthalene, phenanthrene, and anthracene as sole sources of carbon and energy for growth. A forty kilobase region of DNA containing most of the genes for the degradation of these aromatic compounds was previously cloned and sequenced. Insertional inactivation of bphC results in the inability of B1 to grow on both polycyclic and monocyclic compounds. Complementation experiments indicate that the metabolic block is actually due to a Polar Effect on the expression of bphA3 , coding for a ferredoxin component of a dioxygenase. Lack of the ferredoxin results in a nonfunctional polycyclic aromatic hydrocarbon dioxygenase and a nonfunctional toluate dioxygenase indicating that the electron transfer components are capable of interacting with multiple oxygenase components. Insertional inactivation of a gene for a dioxygenase oxygenase component downstream of bphA3 had no apparent Effect on growth besides a Polar Effect on nahD which is only needed for growth of B1 on naphthalene. Insertional inactivation of either xylE or xylG in the meta -cleavage operon results in a Polar Effect on bphB , the last gene in the operon. However, insertional inactivation of xylX at the beginning of this cluster of genes does not result in a Polar Effect suggesting that the genes for the meta -cleavage pathway, although colinear, are organized in at least two operons. These experiments confirm the biological role of several genes involved in metabolism of aromatic compounds by S. yanoikuyae B1 and demonstrate the interdependency of the metabolic pathways for polycyclic and monocyclic aromatic hydrocarbon degradation.

  • Functional analysis of genes involved in biphenyl, naphthalene, phenanthrene, and m-xylene degradation by Sphingomonas yanoikuyae B1.
    Journal of Industrial Microbiology & Biotechnology, 1999
    Co-Authors: E Kim, G J Zylstra
    Abstract:

    Sphingomonas yanoikuyae B1 is able to utilize toluene, m-xylene, p-xylene, biphenyl, naphthalene, phenanthrene, and anthracene as sole sources of carbon and energy for growth. A forty kilobase region of DNA containing most of the genes for the degradation of these aromatic compounds was previously cloned and sequenced. Insertional inactivation of bphC results in the inability of B1 to grow on both polycyclic and monocyclic compounds. Complementation experiments indicate that the metabolic block is actually due to a Polar Effect on the expression of bphA3, coding for a ferredoxin component of a dioxygenase. Lack of the ferredoxin results in a nonfunctional polycyclic aromatic hydrocarbon dioxygenase and a nonfunctional toluate dioxygenase indicating that the electron transfer components are capable of interacting with multiple oxygenase components. Insertional inactivation of a gene for a dioxygenase oxygenase component downstream of bphA3 had no apparent Effect on growth besides a Polar Effect on nahD which is only needed for growth of B1 on naphthalene. Insertional inactivation of either xylE or xylG in the meta-cleavage operon results in a Polar Effect on bphB, the last gene in the operon. However, insertional inactivation of xylX at the beginning of this cluster of genes does not result in a Polar Effect suggesting that the genes for the meta-cleavage pathway, although colinear, are organized in at least two operons. These experiments confirm the biological role of several genes involved in metabolism of aromatic compounds by S. yanoikuyae B1 and demonstrate the interdependency of the metabolic pathways for polycyclic and monocyclic aromatic hydrocarbon degradation.

E Kim - One of the best experts on this subject based on the ideXlab platform.

  • Functional analysis of genes involved in biphenyl, naphthalene, phenanthrene, and m-xylene degradation by Sphingomonas yanoikuyae B1
    Journal of Industrial Microbiology and Biotechnology, 1999
    Co-Authors: E Kim, G J Zylstra
    Abstract:

    B1 is able to utilize toluene, m -xylene, p -xylene, biphenyl, naphthalene, phenanthrene, and anthracene as sole sources of carbon and energy for growth. A forty kilobase region of DNA containing most of the genes for the degradation of these aromatic compounds was previously cloned and sequenced. Insertional inactivation of bphC results in the inability of B1 to grow on both polycyclic and monocyclic compounds. Complementation experiments indicate that the metabolic block is actually due to a Polar Effect on the expression of bphA3 , coding for a ferredoxin component of a dioxygenase. Lack of the ferredoxin results in a nonfunctional polycyclic aromatic hydrocarbon dioxygenase and a nonfunctional toluate dioxygenase indicating that the electron transfer components are capable of interacting with multiple oxygenase components. Insertional inactivation of a gene for a dioxygenase oxygenase component downstream of bphA3 had no apparent Effect on growth besides a Polar Effect on nahD which is only needed for growth of B1 on naphthalene. Insertional inactivation of either xylE or xylG in the meta -cleavage operon results in a Polar Effect on bphB , the last gene in the operon. However, insertional inactivation of xylX at the beginning of this cluster of genes does not result in a Polar Effect suggesting that the genes for the meta -cleavage pathway, although colinear, are organized in at least two operons. These experiments confirm the biological role of several genes involved in metabolism of aromatic compounds by S. yanoikuyae B1 and demonstrate the interdependency of the metabolic pathways for polycyclic and monocyclic aromatic hydrocarbon degradation.

  • Functional analysis of genes involved in biphenyl, naphthalene, phenanthrene, and m-xylene degradation by Sphingomonas yanoikuyae B1.
    Journal of Industrial Microbiology & Biotechnology, 1999
    Co-Authors: E Kim, G J Zylstra
    Abstract:

    Sphingomonas yanoikuyae B1 is able to utilize toluene, m-xylene, p-xylene, biphenyl, naphthalene, phenanthrene, and anthracene as sole sources of carbon and energy for growth. A forty kilobase region of DNA containing most of the genes for the degradation of these aromatic compounds was previously cloned and sequenced. Insertional inactivation of bphC results in the inability of B1 to grow on both polycyclic and monocyclic compounds. Complementation experiments indicate that the metabolic block is actually due to a Polar Effect on the expression of bphA3, coding for a ferredoxin component of a dioxygenase. Lack of the ferredoxin results in a nonfunctional polycyclic aromatic hydrocarbon dioxygenase and a nonfunctional toluate dioxygenase indicating that the electron transfer components are capable of interacting with multiple oxygenase components. Insertional inactivation of a gene for a dioxygenase oxygenase component downstream of bphA3 had no apparent Effect on growth besides a Polar Effect on nahD which is only needed for growth of B1 on naphthalene. Insertional inactivation of either xylE or xylG in the meta-cleavage operon results in a Polar Effect on bphB, the last gene in the operon. However, insertional inactivation of xylX at the beginning of this cluster of genes does not result in a Polar Effect suggesting that the genes for the meta-cleavage pathway, although colinear, are organized in at least two operons. These experiments confirm the biological role of several genes involved in metabolism of aromatic compounds by S. yanoikuyae B1 and demonstrate the interdependency of the metabolic pathways for polycyclic and monocyclic aromatic hydrocarbon degradation.

Shunzo Yamamoto - One of the best experts on this subject based on the ideXlab platform.

  • Effects of alcohols on emission spectra of toluene-triethylamine mixtures in THF: separation into Polar and hydrogen-bonding interactions
    Journal of Photochemistry and Photobiology A-chemistry, 2004
    Co-Authors: Guobin Xie, Yoshimi Sueishi, Shunzo Yamamoto
    Abstract:

    The emission spectra of toluene (T)–triethylamine (TEA) systems were measured under conditions of steady-state illumination in some protic and aprotic solvent–THF mixtures. The fluorescence spectrum of the T–TEA system in THF could be separated into three component bands (band A at 279 nm (fluorescence of T), band B at 336 nm (fluorescence of TEA) and band C at 373 nm (emission from an intermolecular exciplex)). The intensities of bands B and C decreased with increasing solvent Polarity. The decrease in the intensities of bands B and C is considered to be caused by the enhanced conversion of the exciplex to an ion-pair with increase in solvent Polarity. The intensities of bands B and C also decreased owing to the hydrogen-bonding interaction between TEA and protic solvents, but in this case the intensity of band A increased. Acetonitrile only has a Polar Effect and trichloroacetic acid only has a hydrogen-bonding (or protonation) Effect, while alcohols have both Effects. The equilibrium constants for the formation of intermolecular hydrogen-bonded complexes of TEA with alcohols were estimated from the changes in the intensity of band A. The hydrogen-bonding and Polar Effects of alcohols on the intensities of bands B and C could be evaluated separately. The ratio of the hydrogen-bonding Effect to the Polar Effect of alcohols was observed to increase with increasing vol.% of alcohol.

  • Effects of alcohols on emission spectra of toluene–triethylamine mixtures in THF: separation into Polar and hydrogen-bonding interactions
    Journal of Photochemistry and Photobiology A: Chemistry, 2004
    Co-Authors: Guobin Xie, Yoshimi Sueishi, Shunzo Yamamoto
    Abstract:

    The emission spectra of toluene (T)–triethylamine (TEA) systems were measured under conditions of steady-state illumination in some protic and aprotic solvent–THF mixtures. The fluorescence spectrum of the T–TEA system in THF could be separated into three component bands (band A at 279 nm (fluorescence of T), band B at 336 nm (fluorescence of TEA) and band C at 373 nm (emission from an intermolecular exciplex)). The intensities of bands B and C decreased with increasing solvent Polarity. The decrease in the intensities of bands B and C is considered to be caused by the enhanced conversion of the exciplex to an ion-pair with increase in solvent Polarity. The intensities of bands B and C also decreased owing to the hydrogen-bonding interaction between TEA and protic solvents, but in this case the intensity of band A increased. Acetonitrile only has a Polar Effect and trichloroacetic acid only has a hydrogen-bonding (or protonation) Effect, while alcohols have both Effects. The equilibrium constants for the formation of intermolecular hydrogen-bonded complexes of TEA with alcohols were estimated from the changes in the intensity of band A. The hydrogen-bonding and Polar Effects of alcohols on the intensities of bands B and C could be evaluated separately. The ratio of the hydrogen-bonding Effect to the Polar Effect of alcohols was observed to increase with increasing vol.% of alcohol.

  • Effects of 1-Butanol on Emission Spectrum of 4-Phenyl-1-N,N-dimethylaminobutane in THF: Separation into Polar and Hydrogen-Bonding Interactions
    Chemistry Letters, 2002
    Co-Authors: Shunzo Yamamoto, Xie Guobin, Mayuko Nakamura, Yoshimi Sueishi
    Abstract:

    The Effects of the addition of 1-butanol (BuOH), trichloroacetic acid (TCAA) and acetonitrile (AN) on the emission spectrum of 4-phenyl-1-N,N-dimethylaminobutane in THF have been studied. The results show that AN has only a Polar Effect and TCAA only a hydrogen-bonding (or protonation) Effect, while BuOH has both Effects. The relative magnitude of each Effect was evaluated as a function of vol% of BuOH.

Guobin Xie - One of the best experts on this subject based on the ideXlab platform.

  • Effects of alcohols on emission spectra of toluene-triethylamine mixtures in THF: separation into Polar and hydrogen-bonding interactions
    Journal of Photochemistry and Photobiology A-chemistry, 2004
    Co-Authors: Guobin Xie, Yoshimi Sueishi, Shunzo Yamamoto
    Abstract:

    The emission spectra of toluene (T)–triethylamine (TEA) systems were measured under conditions of steady-state illumination in some protic and aprotic solvent–THF mixtures. The fluorescence spectrum of the T–TEA system in THF could be separated into three component bands (band A at 279 nm (fluorescence of T), band B at 336 nm (fluorescence of TEA) and band C at 373 nm (emission from an intermolecular exciplex)). The intensities of bands B and C decreased with increasing solvent Polarity. The decrease in the intensities of bands B and C is considered to be caused by the enhanced conversion of the exciplex to an ion-pair with increase in solvent Polarity. The intensities of bands B and C also decreased owing to the hydrogen-bonding interaction between TEA and protic solvents, but in this case the intensity of band A increased. Acetonitrile only has a Polar Effect and trichloroacetic acid only has a hydrogen-bonding (or protonation) Effect, while alcohols have both Effects. The equilibrium constants for the formation of intermolecular hydrogen-bonded complexes of TEA with alcohols were estimated from the changes in the intensity of band A. The hydrogen-bonding and Polar Effects of alcohols on the intensities of bands B and C could be evaluated separately. The ratio of the hydrogen-bonding Effect to the Polar Effect of alcohols was observed to increase with increasing vol.% of alcohol.

  • Effects of alcohols on emission spectra of toluene–triethylamine mixtures in THF: separation into Polar and hydrogen-bonding interactions
    Journal of Photochemistry and Photobiology A: Chemistry, 2004
    Co-Authors: Guobin Xie, Yoshimi Sueishi, Shunzo Yamamoto
    Abstract:

    The emission spectra of toluene (T)–triethylamine (TEA) systems were measured under conditions of steady-state illumination in some protic and aprotic solvent–THF mixtures. The fluorescence spectrum of the T–TEA system in THF could be separated into three component bands (band A at 279 nm (fluorescence of T), band B at 336 nm (fluorescence of TEA) and band C at 373 nm (emission from an intermolecular exciplex)). The intensities of bands B and C decreased with increasing solvent Polarity. The decrease in the intensities of bands B and C is considered to be caused by the enhanced conversion of the exciplex to an ion-pair with increase in solvent Polarity. The intensities of bands B and C also decreased owing to the hydrogen-bonding interaction between TEA and protic solvents, but in this case the intensity of band A increased. Acetonitrile only has a Polar Effect and trichloroacetic acid only has a hydrogen-bonding (or protonation) Effect, while alcohols have both Effects. The equilibrium constants for the formation of intermolecular hydrogen-bonded complexes of TEA with alcohols were estimated from the changes in the intensity of band A. The hydrogen-bonding and Polar Effects of alcohols on the intensities of bands B and C could be evaluated separately. The ratio of the hydrogen-bonding Effect to the Polar Effect of alcohols was observed to increase with increasing vol.% of alcohol.

Yoshimi Sueishi - One of the best experts on this subject based on the ideXlab platform.

  • Effects of alcohols on emission spectra of toluene-triethylamine mixtures in THF: separation into Polar and hydrogen-bonding interactions
    Journal of Photochemistry and Photobiology A-chemistry, 2004
    Co-Authors: Guobin Xie, Yoshimi Sueishi, Shunzo Yamamoto
    Abstract:

    The emission spectra of toluene (T)–triethylamine (TEA) systems were measured under conditions of steady-state illumination in some protic and aprotic solvent–THF mixtures. The fluorescence spectrum of the T–TEA system in THF could be separated into three component bands (band A at 279 nm (fluorescence of T), band B at 336 nm (fluorescence of TEA) and band C at 373 nm (emission from an intermolecular exciplex)). The intensities of bands B and C decreased with increasing solvent Polarity. The decrease in the intensities of bands B and C is considered to be caused by the enhanced conversion of the exciplex to an ion-pair with increase in solvent Polarity. The intensities of bands B and C also decreased owing to the hydrogen-bonding interaction between TEA and protic solvents, but in this case the intensity of band A increased. Acetonitrile only has a Polar Effect and trichloroacetic acid only has a hydrogen-bonding (or protonation) Effect, while alcohols have both Effects. The equilibrium constants for the formation of intermolecular hydrogen-bonded complexes of TEA with alcohols were estimated from the changes in the intensity of band A. The hydrogen-bonding and Polar Effects of alcohols on the intensities of bands B and C could be evaluated separately. The ratio of the hydrogen-bonding Effect to the Polar Effect of alcohols was observed to increase with increasing vol.% of alcohol.

  • Effects of alcohols on emission spectra of toluene–triethylamine mixtures in THF: separation into Polar and hydrogen-bonding interactions
    Journal of Photochemistry and Photobiology A: Chemistry, 2004
    Co-Authors: Guobin Xie, Yoshimi Sueishi, Shunzo Yamamoto
    Abstract:

    The emission spectra of toluene (T)–triethylamine (TEA) systems were measured under conditions of steady-state illumination in some protic and aprotic solvent–THF mixtures. The fluorescence spectrum of the T–TEA system in THF could be separated into three component bands (band A at 279 nm (fluorescence of T), band B at 336 nm (fluorescence of TEA) and band C at 373 nm (emission from an intermolecular exciplex)). The intensities of bands B and C decreased with increasing solvent Polarity. The decrease in the intensities of bands B and C is considered to be caused by the enhanced conversion of the exciplex to an ion-pair with increase in solvent Polarity. The intensities of bands B and C also decreased owing to the hydrogen-bonding interaction between TEA and protic solvents, but in this case the intensity of band A increased. Acetonitrile only has a Polar Effect and trichloroacetic acid only has a hydrogen-bonding (or protonation) Effect, while alcohols have both Effects. The equilibrium constants for the formation of intermolecular hydrogen-bonded complexes of TEA with alcohols were estimated from the changes in the intensity of band A. The hydrogen-bonding and Polar Effects of alcohols on the intensities of bands B and C could be evaluated separately. The ratio of the hydrogen-bonding Effect to the Polar Effect of alcohols was observed to increase with increasing vol.% of alcohol.

  • Effects of 1-Butanol on Emission Spectrum of 4-Phenyl-1-N,N-dimethylaminobutane in THF: Separation into Polar and Hydrogen-Bonding Interactions
    Chemistry Letters, 2002
    Co-Authors: Shunzo Yamamoto, Xie Guobin, Mayuko Nakamura, Yoshimi Sueishi
    Abstract:

    The Effects of the addition of 1-butanol (BuOH), trichloroacetic acid (TCAA) and acetonitrile (AN) on the emission spectrum of 4-phenyl-1-N,N-dimethylaminobutane in THF have been studied. The results show that AN has only a Polar Effect and TCAA only a hydrogen-bonding (or protonation) Effect, while BuOH has both Effects. The relative magnitude of each Effect was evaluated as a function of vol% of BuOH.