The Experts below are selected from a list of 855 Experts worldwide ranked by ideXlab platform
Lucia I C De Figueroa - One of the best experts on this subject based on the ideXlab platform.
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relationship among carotenoid production copper bioremediation and oxidative stress in rhodotorula mucilaginosa rcl 11
Process Biochemistry, 2013Co-Authors: Veronica Irazusta, Carlos G Nietopenalver, Maria Eugenia Sesto Cabral, Maria Julia Del R Amoroso, Lucia I C De FigueroaAbstract:Rhodotorula mucilaginosa RCL-11, a pigmented yeast isolated from a filter plant of a copper mine in the province of Tucuman, Argentina, supports high concentrations of the heavy metal Cu(II). Copper overload augmented carotenoid biosynthesis in this yeast, modifying at the same time the relative proportion of the pigments produced. Inhibition of the synthesis pathway with diphenylamine suggests an inverse relationship between carotenoid and copper biosorption by R. mucilaginosa RCL-11. The increased activity of superoxide dismutase and catalase measured under inhibition of carotenoid biosynthesis could explain these observations. Exposure to H2O2, a second oxidative stress agent, alone or in combination with Cu(II) also modified the carotenoid content, both qualitatively and quantitatively. The change in the relative proportion of the carotenoids torularhodin, torulene and beta-carotena, as well as the detection of Gamma-Carotene in the presence of H2O2 and Cu(II) allows to hypothesize that the carotenoids produced by R. mucilaginosa RCL-11 plays different roles in the oxidative stress response of this yeast.
Satoshi Hanada - One of the best experts on this subject based on the ideXlab platform.
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roseiflexus castenholzii gen nov sp nov a thermophilic filamentous photosynthetic bacterium that lacks chlorosomes
International Journal of Systematic and Evolutionary Microbiology, 2002Co-Authors: Satoshi Hanada, Shinichi Takaichi, Katsumi Matsuura, Kazunori NakamuraAbstract:A novel thermophilic, photosynthetic bacterium, designated strain HLO8T, was isolated from a bacterial mat in a Japanese hot spring. Morphologically, the isolate was an unbranched multicellular filament with a cell diameter of 0.8-1.0 microm. The bacterium was red to reddish-brown in colour and formed a distinct red bacterial mat in the natural environment. It was able to grow photoheterotrophically under anaerobic light conditions and also chemoheterotrophically under aerobic dark conditions. Optimal growth occurred at 50 degrees C and pH 7.5-8.0. The cells contained bacteriochlorophyll (Bchl) a and Gamma-Carotene derivatives as photosynthetic pigments, but lacked Bchl c and chlorosomes. Cellular fatty acids in the isolate were mainly C16:0, C14:0 and C15:0. The major quinone was menaquinone-11. The DNA G+C content was 62.0 mol% (by HPLC). Phylogenetic analysis based on 16S rDNA sequencing suggested that the isolate belonged to the anoxygenic filamentous phototrophic bacteria represented by Chloroflexus aurantiacus, but was clearly distant from all members in this group (the sequence similarities between the isolate and its relatives were less than 83.8%). Based on genotypic and phenotypic data, the name Roseiflexus castenholzii gen. nov., sp. nov. is proposed for this isolate; the type strain is HLO8T (= DSM 13941T = JCM 11240T).
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absence of Carotenes and presence of a tertiary methoxy group in a carotenoid from a thermophilic filamentous photosynthetic bacterium roseiflexus castenholzii
Plant and Cell Physiology, 2001Co-Authors: Shinichi Takaichi, Takashi Maoka, Mitsunori Yamada, Katsumi Matsuura, Yuji Haikawa, Satoshi HanadaAbstract:We identified pigments in a thermophilic filamentous photosynthetic bacterium Roseiflexus castenholzii strain HL08. We detected neither bacteriochlorophyll (BChl) c nor Carotenes in this bacterium cultured under the aerobic dark and the anaerobic light conditions, which may correspond to its lack of chlorosomes. In the cells cultured under the aerobic dark conditions, the carotenoids were derivatives of keto-Gamma-Carotene, and the major ones were methoxy-keto-myxocoxanthin and keto-myxocoxanthin glucoside fatty acid ester. Although the tertiary methoxy group at C-1' and the double bond at C-3',4' in the psi end group of carotenoid, such as spirilloxanthin, have only been found in purple bacteria, this was the first such report in other bacterial groups. The fatty acid moiety was composed of iso fatty acids, which were rare in the cellular lipids. In the cells cultured under the anaerobic light conditions, in addition to these keto-carotenoids, we also found non-oxidized carotenoids (derivatives of Gamma-Carotene). Concerning the esterifying alcohol of BChl a, we found a substantial amount of geranylgeraniol, although the major component was phytol. The existence of these pigments makes this bacterium unique among the known species in CHLOROFLEXACEAE.
Shinichi Takaichi - One of the best experts on this subject based on the ideXlab platform.
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roseiflexus castenholzii gen nov sp nov a thermophilic filamentous photosynthetic bacterium that lacks chlorosomes
International Journal of Systematic and Evolutionary Microbiology, 2002Co-Authors: Satoshi Hanada, Shinichi Takaichi, Katsumi Matsuura, Kazunori NakamuraAbstract:A novel thermophilic, photosynthetic bacterium, designated strain HLO8T, was isolated from a bacterial mat in a Japanese hot spring. Morphologically, the isolate was an unbranched multicellular filament with a cell diameter of 0.8-1.0 microm. The bacterium was red to reddish-brown in colour and formed a distinct red bacterial mat in the natural environment. It was able to grow photoheterotrophically under anaerobic light conditions and also chemoheterotrophically under aerobic dark conditions. Optimal growth occurred at 50 degrees C and pH 7.5-8.0. The cells contained bacteriochlorophyll (Bchl) a and Gamma-Carotene derivatives as photosynthetic pigments, but lacked Bchl c and chlorosomes. Cellular fatty acids in the isolate were mainly C16:0, C14:0 and C15:0. The major quinone was menaquinone-11. The DNA G+C content was 62.0 mol% (by HPLC). Phylogenetic analysis based on 16S rDNA sequencing suggested that the isolate belonged to the anoxygenic filamentous phototrophic bacteria represented by Chloroflexus aurantiacus, but was clearly distant from all members in this group (the sequence similarities between the isolate and its relatives were less than 83.8%). Based on genotypic and phenotypic data, the name Roseiflexus castenholzii gen. nov., sp. nov. is proposed for this isolate; the type strain is HLO8T (= DSM 13941T = JCM 11240T).
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absence of Carotenes and presence of a tertiary methoxy group in a carotenoid from a thermophilic filamentous photosynthetic bacterium roseiflexus castenholzii
Plant and Cell Physiology, 2001Co-Authors: Shinichi Takaichi, Takashi Maoka, Mitsunori Yamada, Katsumi Matsuura, Yuji Haikawa, Satoshi HanadaAbstract:We identified pigments in a thermophilic filamentous photosynthetic bacterium Roseiflexus castenholzii strain HL08. We detected neither bacteriochlorophyll (BChl) c nor Carotenes in this bacterium cultured under the aerobic dark and the anaerobic light conditions, which may correspond to its lack of chlorosomes. In the cells cultured under the aerobic dark conditions, the carotenoids were derivatives of keto-Gamma-Carotene, and the major ones were methoxy-keto-myxocoxanthin and keto-myxocoxanthin glucoside fatty acid ester. Although the tertiary methoxy group at C-1' and the double bond at C-3',4' in the psi end group of carotenoid, such as spirilloxanthin, have only been found in purple bacteria, this was the first such report in other bacterial groups. The fatty acid moiety was composed of iso fatty acids, which were rare in the cellular lipids. In the cells cultured under the anaerobic light conditions, in addition to these keto-carotenoids, we also found non-oxidized carotenoids (derivatives of Gamma-Carotene). Concerning the esterifying alcohol of BChl a, we found a substantial amount of geranylgeraniol, although the major component was phytol. The existence of these pigments makes this bacterium unique among the known species in CHLOROFLEXACEAE.
Carlos G Nietopenalver - One of the best experts on this subject based on the ideXlab platform.
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relationship among carotenoid production copper bioremediation and oxidative stress in rhodotorula mucilaginosa rcl 11
Process Biochemistry, 2013Co-Authors: Veronica Irazusta, Carlos G Nietopenalver, Maria Eugenia Sesto Cabral, Maria Julia Del R Amoroso, Lucia I C De FigueroaAbstract:Rhodotorula mucilaginosa RCL-11, a pigmented yeast isolated from a filter plant of a copper mine in the province of Tucuman, Argentina, supports high concentrations of the heavy metal Cu(II). Copper overload augmented carotenoid biosynthesis in this yeast, modifying at the same time the relative proportion of the pigments produced. Inhibition of the synthesis pathway with diphenylamine suggests an inverse relationship between carotenoid and copper biosorption by R. mucilaginosa RCL-11. The increased activity of superoxide dismutase and catalase measured under inhibition of carotenoid biosynthesis could explain these observations. Exposure to H2O2, a second oxidative stress agent, alone or in combination with Cu(II) also modified the carotenoid content, both qualitatively and quantitatively. The change in the relative proportion of the carotenoids torularhodin, torulene and beta-carotena, as well as the detection of Gamma-Carotene in the presence of H2O2 and Cu(II) allows to hypothesize that the carotenoids produced by R. mucilaginosa RCL-11 plays different roles in the oxidative stress response of this yeast.
Maria Julia Del R Amoroso - One of the best experts on this subject based on the ideXlab platform.
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relationship among carotenoid production copper bioremediation and oxidative stress in rhodotorula mucilaginosa rcl 11
Process Biochemistry, 2013Co-Authors: Veronica Irazusta, Carlos G Nietopenalver, Maria Eugenia Sesto Cabral, Maria Julia Del R Amoroso, Lucia I C De FigueroaAbstract:Rhodotorula mucilaginosa RCL-11, a pigmented yeast isolated from a filter plant of a copper mine in the province of Tucuman, Argentina, supports high concentrations of the heavy metal Cu(II). Copper overload augmented carotenoid biosynthesis in this yeast, modifying at the same time the relative proportion of the pigments produced. Inhibition of the synthesis pathway with diphenylamine suggests an inverse relationship between carotenoid and copper biosorption by R. mucilaginosa RCL-11. The increased activity of superoxide dismutase and catalase measured under inhibition of carotenoid biosynthesis could explain these observations. Exposure to H2O2, a second oxidative stress agent, alone or in combination with Cu(II) also modified the carotenoid content, both qualitatively and quantitatively. The change in the relative proportion of the carotenoids torularhodin, torulene and beta-carotena, as well as the detection of Gamma-Carotene in the presence of H2O2 and Cu(II) allows to hypothesize that the carotenoids produced by R. mucilaginosa RCL-11 plays different roles in the oxidative stress response of this yeast.
