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Judit Kucsera - One of the best experts on this subject based on the ideXlab platform.

  • Characterization of petite mutants of the basidiomycetes Phaffia Rhodozyma CBS 5905
    2010
    Co-Authors: Ilona Pfeiffer, Csaba Vágvölgyi, Tadashi Hirano, Judit Kucsera
    Abstract:

    Small, ''petite'' colonies appeared with almost 1% frequency among the nor- mally growing colonies in the astaxanthin-producing Phaffia Rhodozyma (Xanthophyllomyces dendrorhous) CBS 5905 strain. These colonies fermented glucose in the presence of oxygen, were not able to grow on nonfermentable carbon sources and did not respond to inhibitors of respiration. Besides spontaneous occurrence, petite mutation proved to be inducible almost to 100% by low levels of ethidium bromide treatment. Cell hybridization experiments revealed that both the spontaneous and induced mutation was mitochondrially inherited. The RFLP pat- tern of the mtDNAs isolated from purified mitochondria of the grand and petite strains were similar. Consequently, unlike to the mtDNA of Saccharomyces cerevisiae, not large deletions were the reason for petite mutant induction. The size of mtDNA in the grand cells was calculated by restriction enzyme analysis and proved approximately 17.6 kb. In teleomorphic strains of P. Rhodozyma (Xanthophyllomyces dendrorhous) spontaneous petite mutants did not arise and the phenotype could not be induced either by ethidium bromide treatment. According to our results, Phaffia Rhodozyma is the only known petite-positive basidiomycetous yeast.

  • Biology of the red yeastXanthophyllomyces dendrorhous (Phaffia Rhodozyma)
    Mycoscience, 2000
    Co-Authors: Judit Kucsera, Ilona Pfeiffer, Kanji Takeo
    Abstract:

    Phaffia Rhodozyma is a red-pigmented basidiomycetous yeast that produces astaxanthin. Because of this property, it is fermented commercially on a large scale. Astaxanthin is used as a food colorant for fish, and as an antioxidant, it is potentially useful in the human pharmaceutical industry. This review summarizes the published biology of this yeast: its morphology and ultrastructure, organization of the cytoskeleton, and the nuclear and extrachromosomal genomes. Alteration of sexual and vegetative phases in the life cycle and its biotechnological importance are also described.

  • Biology of the red yeast Xanthophyllomyces dendrorhous (Phaffia Rhodozyma)
    Mycoscience, 2000
    Co-Authors: Judit Kucsera, Ilona Pfeiffer, Kanji Takeo
    Abstract:

    Phaffia Rhodozyma is a red-pigmented basidiomycetous yeast that produces astaxanthin. Because of this property, it is fermented commercially on a large scale. Astaxanthin is used as a food colorant for fish, and as an antioxidant, it is potentially useful in the human pharmaceutical industry. This review summarizes the published biology of this yeast: its morphology and ultrastructure, organization of the cytoskeleton, and the nuclear and extrachromosomal genomes. Alteration of sexual and vegetative phases in the life cycle and its biotechnological importance are also described.

  • Homothallic life cycle in the diploid red yeast Xanthophyllomyces dendrorhous (Phaffia Rhodozyma).
    Antonie van Leeuwenhoek, 1998
    Co-Authors: Judit Kucsera, Ilona Pfeiffer, Lajos Ferenczy
    Abstract:

    Sexual activity was induced in the basidiomyceteous Phaffia Rhodozyma (Xanthophyllomyces dendrorhous) by depletion of nitrogen from the culture medium. This activity involved both mating between two yeast cells and the formation of basidiospores. Mating is possibly started by a G1 phase arrest of the cell cycle, as in other yeasts. The life cycle exhibited homothallic features. Crosses between genetically marked strains, and pulse-field gel electrophoresis of the chromosomal DNA of cells derived from individual spores revealed evidence of karyogamy, meiosis and even recombination. The segregation ratio in tetrads pointed to diploid vegetative cells, which formed tetraploid zygotes and the immediate meiosis then gave rise to diploid progenies again. Apart from the type strain Phaffia Rhodozyma CBS 5905, all the examined strains were able to sporulate.

  • variability and inheritance of double stranded rna viruses in Phaffia Rhodozyma
    Current Genetics, 1996
    Co-Authors: Ilona Pfeiffer, Judit Kucsera, Janos Varga, Arpad Parducz, Lajos Ferenczy
    Abstract:

    The present survey demonstrates polymorphism in both the length and the number of double-stranded RNAs (dsRNAs) among six Phaffia Rhodozyma strains. Strains with one-, three- and four-types of dsRNA molecules were found, while two strains proved to be dsRNA-free. Elongated icosahedral virus-like particles (VLPs) 34×26 nm in size were detected in strains carrying four- or three-types of dsRNAs. One 3.7-kb dsRNA molecule was found not to form part of the VLP genome. Transmission of the VLPs of strain ATCC 24203 was followed through the basidiospores during the sexual cycle. Cytoplasmic inheritance was observed.

Ilona Pfeiffer - One of the best experts on this subject based on the ideXlab platform.

  • Characterization of petite mutants of the basidiomycetes Phaffia Rhodozyma CBS 5905
    2010
    Co-Authors: Ilona Pfeiffer, Csaba Vágvölgyi, Tadashi Hirano, Judit Kucsera
    Abstract:

    Small, ''petite'' colonies appeared with almost 1% frequency among the nor- mally growing colonies in the astaxanthin-producing Phaffia Rhodozyma (Xanthophyllomyces dendrorhous) CBS 5905 strain. These colonies fermented glucose in the presence of oxygen, were not able to grow on nonfermentable carbon sources and did not respond to inhibitors of respiration. Besides spontaneous occurrence, petite mutation proved to be inducible almost to 100% by low levels of ethidium bromide treatment. Cell hybridization experiments revealed that both the spontaneous and induced mutation was mitochondrially inherited. The RFLP pat- tern of the mtDNAs isolated from purified mitochondria of the grand and petite strains were similar. Consequently, unlike to the mtDNA of Saccharomyces cerevisiae, not large deletions were the reason for petite mutant induction. The size of mtDNA in the grand cells was calculated by restriction enzyme analysis and proved approximately 17.6 kb. In teleomorphic strains of P. Rhodozyma (Xanthophyllomyces dendrorhous) spontaneous petite mutants did not arise and the phenotype could not be induced either by ethidium bromide treatment. According to our results, Phaffia Rhodozyma is the only known petite-positive basidiomycetous yeast.

  • Biology of the red yeastXanthophyllomyces dendrorhous (Phaffia Rhodozyma)
    Mycoscience, 2000
    Co-Authors: Judit Kucsera, Ilona Pfeiffer, Kanji Takeo
    Abstract:

    Phaffia Rhodozyma is a red-pigmented basidiomycetous yeast that produces astaxanthin. Because of this property, it is fermented commercially on a large scale. Astaxanthin is used as a food colorant for fish, and as an antioxidant, it is potentially useful in the human pharmaceutical industry. This review summarizes the published biology of this yeast: its morphology and ultrastructure, organization of the cytoskeleton, and the nuclear and extrachromosomal genomes. Alteration of sexual and vegetative phases in the life cycle and its biotechnological importance are also described.

  • Biology of the red yeast Xanthophyllomyces dendrorhous (Phaffia Rhodozyma)
    Mycoscience, 2000
    Co-Authors: Judit Kucsera, Ilona Pfeiffer, Kanji Takeo
    Abstract:

    Phaffia Rhodozyma is a red-pigmented basidiomycetous yeast that produces astaxanthin. Because of this property, it is fermented commercially on a large scale. Astaxanthin is used as a food colorant for fish, and as an antioxidant, it is potentially useful in the human pharmaceutical industry. This review summarizes the published biology of this yeast: its morphology and ultrastructure, organization of the cytoskeleton, and the nuclear and extrachromosomal genomes. Alteration of sexual and vegetative phases in the life cycle and its biotechnological importance are also described.

  • Homothallic life cycle in the diploid red yeast Xanthophyllomyces dendrorhous (Phaffia Rhodozyma).
    Antonie van Leeuwenhoek, 1998
    Co-Authors: Judit Kucsera, Ilona Pfeiffer, Lajos Ferenczy
    Abstract:

    Sexual activity was induced in the basidiomyceteous Phaffia Rhodozyma (Xanthophyllomyces dendrorhous) by depletion of nitrogen from the culture medium. This activity involved both mating between two yeast cells and the formation of basidiospores. Mating is possibly started by a G1 phase arrest of the cell cycle, as in other yeasts. The life cycle exhibited homothallic features. Crosses between genetically marked strains, and pulse-field gel electrophoresis of the chromosomal DNA of cells derived from individual spores revealed evidence of karyogamy, meiosis and even recombination. The segregation ratio in tetrads pointed to diploid vegetative cells, which formed tetraploid zygotes and the immediate meiosis then gave rise to diploid progenies again. Apart from the type strain Phaffia Rhodozyma CBS 5905, all the examined strains were able to sporulate.

  • variability and inheritance of double stranded rna viruses in Phaffia Rhodozyma
    Current Genetics, 1996
    Co-Authors: Ilona Pfeiffer, Judit Kucsera, Janos Varga, Arpad Parducz, Lajos Ferenczy
    Abstract:

    The present survey demonstrates polymorphism in both the length and the number of double-stranded RNAs (dsRNAs) among six Phaffia Rhodozyma strains. Strains with one-, three- and four-types of dsRNA molecules were found, while two strains proved to be dsRNA-free. Elongated icosahedral virus-like particles (VLPs) 34×26 nm in size were detected in strains carrying four- or three-types of dsRNAs. One 3.7-kb dsRNA molecule was found not to form part of the VLP genome. Transmission of the VLPs of strain ATCC 24203 was followed through the basidiospores during the sexual cycle. Cytoplasmic inheritance was observed.

Lajos Ferenczy - One of the best experts on this subject based on the ideXlab platform.

  • Carbon-source assimilation pattern of the astaxanthin-producing yeast Phaffia Rhodozyma
    World Journal of Microbiology and Biotechnology, 2001
    Co-Authors: Zs. Palágyi, Lajos Ferenczy, Cs. Vágvölgyi
    Abstract:

    Eleven Phaffia Rhodozyma strains were assayed for their ability to utilize 99 compounds as single carbon source. Some of them showed modified coloration compared to colonies of the same strain grown on glucose medium.

  • Homothallic life cycle in the diploid red yeast Xanthophyllomyces dendrorhous (Phaffia Rhodozyma).
    Antonie van Leeuwenhoek, 1998
    Co-Authors: Judit Kucsera, Ilona Pfeiffer, Lajos Ferenczy
    Abstract:

    Sexual activity was induced in the basidiomyceteous Phaffia Rhodozyma (Xanthophyllomyces dendrorhous) by depletion of nitrogen from the culture medium. This activity involved both mating between two yeast cells and the formation of basidiospores. Mating is possibly started by a G1 phase arrest of the cell cycle, as in other yeasts. The life cycle exhibited homothallic features. Crosses between genetically marked strains, and pulse-field gel electrophoresis of the chromosomal DNA of cells derived from individual spores revealed evidence of karyogamy, meiosis and even recombination. The segregation ratio in tetrads pointed to diploid vegetative cells, which formed tetraploid zygotes and the immediate meiosis then gave rise to diploid progenies again. Apart from the type strain Phaffia Rhodozyma CBS 5905, all the examined strains were able to sporulate.

  • variability and inheritance of double stranded rna viruses in Phaffia Rhodozyma
    Current Genetics, 1996
    Co-Authors: Ilona Pfeiffer, Judit Kucsera, Janos Varga, Arpad Parducz, Lajos Ferenczy
    Abstract:

    The present survey demonstrates polymorphism in both the length and the number of double-stranded RNAs (dsRNAs) among six Phaffia Rhodozyma strains. Strains with one-, three- and four-types of dsRNA molecules were found, while two strains proved to be dsRNA-free. Elongated icosahedral virus-like particles (VLPs) 34×26 nm in size were detected in strains carrying four- or three-types of dsRNAs. One 3.7-kb dsRNA molecule was found not to form part of the VLP genome. Transmission of the VLPs of strain ATCC 24203 was followed through the basidiospores during the sexual cycle. Cytoplasmic inheritance was observed.

  • Electrophoretic karyotypes of Phaffia Rhodozyma strains
    FEMS Microbiology Letters, 1994
    Co-Authors: Ágnes Nagy, Nándor Garamszegi, Csaba Vágvölgyi, Lajos Ferenczy
    Abstract:

    Electrophoretic karyotypes of strains from the astaxanthin-producing yeast Phaffia Rhodozyma have been established. Intact chromosomal DNA molecules released from protoplasts were separated by orthogonal field alternation gel electrophoresis (OFAGE) and contour clamped homogeneous electric field (CHEF). Both small and large chromosomal DNA molecules were resolved simultaneously by optimizing the running conditions. Electrophoretic karyotypes among the Phaffia isolates examined differed significantly. Seven to thirteen chromosomal bands, ranging in size from 0.83 Mb to 3.50 Mb, were resolved, giving total genome sizes of about 15.4 to 23.2 Mb. Ribosomal DNA has been assigned to chromosomal bands using a heterologous gene probe.

Eric A. Johnson - One of the best experts on this subject based on the ideXlab platform.

  • Genetic manipulation of Xanthophyllomyces dendrorhous and Phaffia Rhodozyma.
    Microbial Carotenoids From Fungi, 2012
    Co-Authors: Guangyun Lin, Eric A. Johnson, Joanna Bultman, Jack W. Fell
    Abstract:

    The yeasts Xanthophyllomyces dendrorhous (teleomorph) and Phaffia Rhodozyma (anamorph) are of basidiomycetous affinity and have the unique property among yeasts of producing the carotenoid pigment astaxanthin. Astaxanthin imparts the attractive coloration to salmonids, crustaceans, and several birds such as the flamingo, and it has considerable economic value. Microbiological and genetic techniques for manipulation are rudimentary in the yeast, while their utility would be valuable for strain development including hypermutants that overproduce astaxanthin. Here we describe methods for manipulation of the yeast, including induction of the sexual stage with basidiospore formation, methods for isolation of mutants (particularly mutants affected in carotenoid biosynthesis) as well as techniques for isolation and analysis of carotenoids. These methods are valuable for understanding the biology and enhancing the biotechnology value of the yeast.

  • Phaffia Rhodozyma: colorful odyssey
    International Microbiology, 2003
    Co-Authors: Eric A. Johnson
    Abstract:

    Phaffia Rhodozyma was isolated by Herman Phaff in the 1960s, during his pioneering studies of yeast ecology. Initially, the yeast was isolated from limited geographical regions, but isolates were subsequently obtained from Russia, Chile, Finland, and the United States. The biological diversity of the yeast is more extensive than originally envisioned by Phaff and his collaborators, and at least two species appear to exist, including the anamorph Phaffia Rhodozyma and the teleomorph Xanthophyllomyces dendrorhous. The yeast has attracted considerable biotechnological interest because of its ability to synthesize the economically important carotenoid astaxanthin (3,3'-dihydroxy-beta, beta-carotene-4,4'-dione) as its major pigment. This property has stimulated research on the biology of the yeast as well as development of the yeast as an industrial microorganism for astaxanthin production by fermentation. Our laboratory has isolated several mutants of the yeast affected in carotenogenesis, giving colonies a vivid array of pigmentation. We have found that nutritional and environmental conditions regulate astaxanthin biosynthesis in the yeast, and have demonstrated that astaxanthin protects P. Rhodozyma from damage by reactive oxygen species. We proposed in the 1970s that P. Rhodozyma could serve as an economically important pigment source in animal diets including salmonids, lobsters, and the egg yolks of chickens and quail, in order to impart characteristic and desirable colors. Although P. Rhodozyma/Xanthomyces dendrorhous has been studied by various researchers for nearly 30 years, it still attracts interest from yeast biologists and biotechnologists. There is a bright and colorful outlook for P. Rhodozyma/X. dendrorhous from fundamental and applied research perspectives.

  • Quantification of carotenoids in cells of Phaffia Rhodozyma by autofluorescence
    Biotechnology Letters, 2000
    Co-Authors: O.-s. Suh, H.-c. Kwon, K. Kim, Eric A. Johnson
    Abstract:

    The distribution and intensity of autofluorescence caused by carotenoids in the yeast Phaffia Rhodozyma was examined by laser confocal fluorescence microscopy. Carotenoid contents of individual yeast cells could be calculated from the value of autofluorescence/unit volume of yeast cell. The average level of fluorescence in highly fluorescing yeast cells was 15 mg carotenoid g−1 yeast which was accepted as the maximum yield of carotenoid in P. Rhodozyma. The method developed in this study is useful for the research of cell biology associated with the biological functions of carotenoids in individual cells.

  • Ethanol increases carotenoid production in Phaffia Rhodozyma
    Journal of Industrial Microbiology & Biotechnology, 1997
    Co-Authors: Eric A. Johnson
    Abstract:

    Addition of ethanol (0.2%) to cultures of the yeast Phaffia Rhodozyma increased the specific rate of carotenoid production [(carotenoid)(cell mass)−1(time)−1]. The incremental increase in carotenoid synthesis with ethanol was highest in carotenoid-hyperproducing strains. Ethanol increased carotenoid production when it was added at various points during the lag and active growth phases. Ethanol increased alcohol dehydrogenase and hydroxy-methyl-glutaryl-CoA (HMG-CoA) reductase activities. Our results indicate that increased carotenoid production by ethanol is associated with induction of HMG-CoA reductase and possibly activation of oxidative metabolism.

  • Antioxidant role of carotenoids in Phaffia Rhodozyma
    Journal of General Microbiology, 1993
    Co-Authors: William A. Schroeder, Eric A. Johnson
    Abstract:

    Summary: The role of carotenoids in protecting the yeast Phaffia Rhodozyma against reactive oxygen species was studied. Addition of the O2 −-generator duroquinone (DQ) to yeast-malt broth increased total carotenoid content as well as the relative amounts of xanthophylls present, while the reactive oxygen scavenger mannitol reversed this effect. Resistance to DQ increased in the stationary phase, particularly in the carotenoid-hyperproducing strain studied. Assay of superoxide dismutase (SOD) in P. Rhodozyma indicated the presence of Mn-SOD and the complete absence of Fe-SOD and Cu/Zn-SOD. Catalase activity in P. Rhodozyma was significantly lower than in Saccharomyces cerevisiae, particularly in stationary cultures. In young cells, H2O2 resistance was directly related to carotenoid levels, and selection of cultures based on peroxide resistance resulted in slightly increased carotenoid production. These results indicate that carotenoids play an antioxidant role during ageing in P. Rhodozyma.

Luis M. Ducrey Santopietro - One of the best experts on this subject based on the ideXlab platform.