The Experts below are selected from a list of 1629 Experts worldwide ranked by ideXlab platform
John A. Buswell - One of the best experts on this subject based on the ideXlab platform.
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Induction of laccase activity in the edible straw mushroom, Volvariella volvacea.
FEMS microbiology letters, 2003Co-Authors: Shicheng Chen, John A. BuswellAbstract:Volvariella volvacea, strain V14, produces multiple forms of extracellular laccase when grown in submerged culture in a defined medium with glucose as sole carbon source, and on cotton waste ‘compost’ representative of the conditions used for industrial-scale mushroom cultivation. In liquid culture, enzyme synthesis is associated with the onset of secondary growth, and is positively regulated by copper (up to 200 μM CuSO4) and by various aromatic compounds. In solid-state systems, only low levels of laccase are detectable during the vegetative growth phase but enzyme activity increases sharply at the onset of fruiting and during sporophore development.
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Transformation of the edible fungi, Pleurotus ostreatus and Volvariella volvacea
Mycological Research, 1998Co-Authors: Jian Hua Jia, John A. Buswell, John F. PeberdyAbstract:A transformation system is described for the edible mushrooms Pleurotus ostreatus and Volvariella volvacea . The system developed is based on a positive selection strategy using the trp3 iar gene from Coprinus cinereus , which confers resistance to the antimetabolite 5-fluoroindole. Transformation frequencies were low in both species. Southern blot analysis confirmed the integration of transforming DNA into the genome of transformants and indicated the presence of tandemly duplicated copies of the plasmid in some of these transformants. The system has potential for introducing beneficial traits such as enhanced substrate bioconversion and faster sporophore development.
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Production of cellulases and hemicellulases by the straw mushroom, Volvariella volvacea
Mycological Research, 1994Co-Authors: Y.j. Cai, John A. Buswell, S. T. ChangAbstract:Carboxymethylcellulase (CMCase), Avicelase and β-glucosidase production was monitored in submerged cultures of two strains (V 14 and V 34) of Volvariella volvacea grown on Avicel. All three cellulolytic enzymes were detectable in culture supernatants, although levels of CMCase and Avicelase were considerably higher in cultures of V. volvacea V 14. β-Glucosidase activity was also observed in mycelial extracts of both fungal strains. Addition of 0·2% Tween 80 to cultures markedly enhanced extracellular cellulase activity, especially in V. volvacea V 34. Cellulases, together with xylanase and both intra- and extracellular β-xylosidase, were also recorded in cultures of V. volvacea V 34 grown on paddy straw.
Mingjie Chen - One of the best experts on this subject based on the ideXlab platform.
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A new approach for breeding low‐temperature resistant Volvariella volvacea strains: Genome shuffling in edible fungi
Biotechnology and applied biochemistry, 2016Co-Authors: Ziping Zhu, Wu Guogan, Wang Jinbin, Jiang Wei, Li Peng, He Jianhua, Chen Jianzhong, Mingjie ChenAbstract:Volvariella volvacea is difficult to store fresh for lack of low-temperature resistance. Many traditional mutagenic strategies have been applied in order to select out strains resistant to low temperature, but few commercially efficient strains have been produced. In order to break through the bottleneck of traditional breeding and significantly improve low-temperature resistance of the edible fungus Volvariella volvacea, strains resistant to low temperature were constructed by genome shuffling. The optimum conditions of Volvariella. volvacea strain mutation, protoplast regeneration and fusion were determined. After protoplasts were treated with 1% (v/v) ethylmethylsulfonate (EMS), 40 s of ultraviolet irradiation (UV), 600 Gy electron beam implantation and 750 Gy60Co-γ irradiation, separately, the lethality was within 70–80%, which favored generating protoplasts being used in following forward mutation. Under these conditions, 16 strains of Volvariella. volvacea mutated by ethylmethylsulfonate, electron beam, ultraviolet irradiation and 60Co-γ irradiation were obtained. The 16 mutated protoplasts were selected to serve as the shuffling pool based on their excellent low-temperature resistance. After four rounds of genome shuffling and low-temperature resistance testing, three strains (VF1, VF2 and VF3) with high genetic stability were screened. VF1, VF2 and VF3 significantly enhanced fruit body shelf life to 20, 28 and 28 h at 10°C, respectively, which exceeded 25, 75 and 75% respectively compared with the storage time of V23, the most low-temperature resistant strain. Genome shuffling greatly improved the low-temperature resistance of Volvariella. volvacea, and shortened the course of screening required to generate desirable strains. To our knowledge, this is the first paper to apply genome shuffling to breeding new varieties of mushroom, and offers a new approach for breeding edible fungi with optimized phenotype. This article is protected by copyright. All rights reserved
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a new approach for breeding low temperature resistant Volvariella volvacea strains genome shuffling in edible fungi
Biotechnology and Applied Biochemistry, 2016Co-Authors: Ziping Zhu, Qi Tan, Mingjie Chen, Dapeng Bao, Jinbin Wang, Wei Jiang, Jianzhong Chen, Jinsong Zhang, Xueming TangAbstract:Volvariella volvacea is difficult to store fresh for lack of low-temperature resistance. Many traditional mutagenic strategies have been applied in order to select out strains resistant to low temperature, but few commercially efficient strains have been produced. In order to break through the bottleneck of traditional breeding and significantly improve low-temperature resistance of the edible fungus Volvariella volvacea, strains resistant to low temperature were constructed by genome shuffling. The optimum conditions of Volvariella. volvacea strain mutation, protoplast regeneration and fusion were determined. After protoplasts were treated with 1% (v/v) ethylmethylsulfonate (EMS), 40 s of ultraviolet irradiation (UV), 600 Gy electron beam implantation and 750 Gy60Co-γ irradiation, separately, the lethality was within 70–80%, which favored generating protoplasts being used in following forward mutation. Under these conditions, 16 strains of Volvariella. volvacea mutated by ethylmethylsulfonate, electron beam, ultraviolet irradiation and 60Co-γ irradiation were obtained. The 16 mutated protoplasts were selected to serve as the shuffling pool based on their excellent low-temperature resistance. After four rounds of genome shuffling and low-temperature resistance testing, three strains (VF1, VF2 and VF3) with high genetic stability were screened. VF1, VF2 and VF3 significantly enhanced fruit body shelf life to 20, 28 and 28 h at 10°C, respectively, which exceeded 25, 75 and 75% respectively compared with the storage time of V23, the most low-temperature resistant strain. Genome shuffling greatly improved the low-temperature resistance of Volvariella. volvacea, and shortened the course of screening required to generate desirable strains. To our knowledge, this is the first paper to apply genome shuffling to breeding new varieties of mushroom, and offers a new approach for breeding edible fungi with optimized phenotype. This article is protected by copyright. All rights reserved
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A newly discovered ubiquitin-conjugating enzyme E2 correlated with the cryogenic autolysis of Volvariella volvacea
Gene, 2016Co-Authors: Ming Gong, Hong Wang, Mingjie Chen, Dapeng Bao, Qiuming Zhu, Qi TanAbstract:In Volvariella volvacea, a species of edible mushroom, cryogenic autolysis is a typical part of abnormal metabolism. Previous functional annotation cluster analyses of cold-induced gene expression profiles have shown that the ubiquitin-conjugating enzyme E2 (UBE2), rather than the cyclin-like F-box domain alone, forms the functional cluster. In this study, analysis of gene expression profiling showed that only one type of UBE2 in V. volvacea (UBEV2) was significantly up-regulated. Further quantitative real-time PCR analysis confirmed that the expression of UBEV2 was significantly up-regulated (P
Jun-fang Lin - One of the best experts on this subject based on the ideXlab platform.
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Purification and Characterization of the Recombinant Multifunctional Cellulase from Volvariella volvacea
Food Biotechnology, 2012Co-Authors: Li-chao Zhao, Li-qiong Guo, Hang Xiao, Lan-juan Zheng, Yan Wang, Jun-fang LinAbstract:The recombinant multifunctional cellulase (MFCase) produced from strain TVM5186 of Volvariella volvacea was purified 270-fold by ultrafiltration, DEAE-Sepharose Fast Flow ion-exchange resin chromatography, and Sephadex G-100 gel filtration, after which the enzyme was characterized. The SDS-PAGE of the transformants showed a prominent band approximately 46 kDa corresponding to the expected size of MFCase (45.8 kDa). The characteristics of the recombinant MFCase were consistent with that expressed by the original gene, indicating that Volvariella volvacea is a foreign gene expression system with correct posttranslational protein processing. The optimum temperatures and pH of the recombinant MFCase for the hydrolysis of xylan and CMC were 55°C and 50°C, and 5.5 and 6.0, respectively. The stability results showed that recombinant MFCase was sensitive to high temperature. The relatively activities remained at 75.6% and 74.4% after heating for 1 h at 50°C, after which its activity decreased. While the pH stabil...
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breeding cold tolerance strain by chemical mutagenesis in Volvariella volvacea
Scientia Horticulturae, 2011Co-Authors: Zhu Liu, Kai Zhang, Jun-fang Lin, Li-qiong GuoAbstract:Abstract Volvariella volvacea is a mushroom well-adapted to high temperature. It optimally grows at 30–35 °C. To breed cold-tolerant strains to expand cultivation region and season, the basidiospores and gills of V. volvacea were treated with chemical mutagens, ethyl methane sulfonate (EMS) and diethyl sulfate (DES), respectively. Two cold-tolerant strains, strains Em-16 and Em-18, were successfully obtained from EMS mutagenesis of gills through 0 °C screening, colony morphology screening and fruiting screening. The biological efficiencies of Em-16 and Em-18 strains were 24.55% and 23.61% in the first flush at 27 °C and their biological efficiencies were 46.1% and 40.5% higher than the control strain V41, respectively. Their fruiting bodies had a longer storage life at 16 °C, compared with the control strain V41. Amplified fragment length polymorphism analysis shows that the strains Em-16 and Em-18 are new strains.
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Highly efficient Agrobacterium-mediated transformation of Volvariella volvacea.
Bioresource technology, 2008Co-Authors: Jie Wang, Li-qiong Guo, Kai Zhang, Jun-fang LinAbstract:Agrobacterium tumefaciens-mediated transformation (ATMT) was successfully applied to the edible straw mushroom, Volvariella volvacea. Mycelium pellets were transformed to cold stress resistance using the afp gene as both a selective marker and a reporter gene, under the control of a heterologous Lentinula edodes gpd promoter. The efficiency of transformation is over 100 times higher than that previously reported in V. volvacea. Stable integration of the afp gene with 1-4 copy numbers was confirmed in all 10 randomly selected transgenic events by Southern blot analysis. The mitotic stability of the transformants was demonstrated after five successive transfers on PDA medium without selection pressure and the PCR analysis of basidiospores harvested from transformants.
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Transformation of Volvariella volvacea with a thermal hysteresis protein gene by particle bombardment
Wei sheng wu xue bao = Acta microbiologica Sinica, 2005Co-Authors: Li-qiong Guo, Jun-fang Lin, Sheng Xiong, Shou-cai ChenAbstract:A cDNA encoding a thermal hysteresis protein was isolated from the Swedish Arctic insect spruce budworm by RT-PCR amplification. Volvariella volvacea strain V34 was transformed with this cDNA through particle bombardment. PCR detection and Southern blotting analysis show that the thermal hysteresis protein gene is integrated into Volvariella volvacea genome. Cold stress assay reveals that transgenic Volvariella volvacea lines exhibit stronger cold tolerance than host strain. The morphological observation of transgenic Volvariella volvacea lines shows that growth rates of most Volvariella volvacea transformants are significantly slower than that of negative control strain. And hypha of most Volvariella volvacea tansformants is thinner than host strain's hypha. Transformant screening result indicates that three-round of selection procedure with first selection on PDSA solid selective medium followed by second and third selection in PDSB liquid selective medium is favorable to get genuine transformants and to eliminate false transformants. Cold tolerance assay of transgenic Volvariella volvacea F1 generation demonstrates that the progeny of transgenic Volvariella volvacea still possesses stronger cold tolerance than non-transformed host strain. This suggests that the cold tolerant characteristic of transgenic Volvariella volvacea is meiotically stable between generations.
Li-qiong Guo - One of the best experts on this subject based on the ideXlab platform.
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Purification and Characterization of the Recombinant Multifunctional Cellulase from Volvariella volvacea
Food Biotechnology, 2012Co-Authors: Li-chao Zhao, Li-qiong Guo, Hang Xiao, Lan-juan Zheng, Yan Wang, Jun-fang LinAbstract:The recombinant multifunctional cellulase (MFCase) produced from strain TVM5186 of Volvariella volvacea was purified 270-fold by ultrafiltration, DEAE-Sepharose Fast Flow ion-exchange resin chromatography, and Sephadex G-100 gel filtration, after which the enzyme was characterized. The SDS-PAGE of the transformants showed a prominent band approximately 46 kDa corresponding to the expected size of MFCase (45.8 kDa). The characteristics of the recombinant MFCase were consistent with that expressed by the original gene, indicating that Volvariella volvacea is a foreign gene expression system with correct posttranslational protein processing. The optimum temperatures and pH of the recombinant MFCase for the hydrolysis of xylan and CMC were 55°C and 50°C, and 5.5 and 6.0, respectively. The stability results showed that recombinant MFCase was sensitive to high temperature. The relatively activities remained at 75.6% and 74.4% after heating for 1 h at 50°C, after which its activity decreased. While the pH stabil...
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breeding cold tolerance strain by chemical mutagenesis in Volvariella volvacea
Scientia Horticulturae, 2011Co-Authors: Zhu Liu, Kai Zhang, Jun-fang Lin, Li-qiong GuoAbstract:Abstract Volvariella volvacea is a mushroom well-adapted to high temperature. It optimally grows at 30–35 °C. To breed cold-tolerant strains to expand cultivation region and season, the basidiospores and gills of V. volvacea were treated with chemical mutagens, ethyl methane sulfonate (EMS) and diethyl sulfate (DES), respectively. Two cold-tolerant strains, strains Em-16 and Em-18, were successfully obtained from EMS mutagenesis of gills through 0 °C screening, colony morphology screening and fruiting screening. The biological efficiencies of Em-16 and Em-18 strains were 24.55% and 23.61% in the first flush at 27 °C and their biological efficiencies were 46.1% and 40.5% higher than the control strain V41, respectively. Their fruiting bodies had a longer storage life at 16 °C, compared with the control strain V41. Amplified fragment length polymorphism analysis shows that the strains Em-16 and Em-18 are new strains.
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Highly efficient Agrobacterium-mediated transformation of Volvariella volvacea.
Bioresource technology, 2008Co-Authors: Jie Wang, Li-qiong Guo, Kai Zhang, Jun-fang LinAbstract:Agrobacterium tumefaciens-mediated transformation (ATMT) was successfully applied to the edible straw mushroom, Volvariella volvacea. Mycelium pellets were transformed to cold stress resistance using the afp gene as both a selective marker and a reporter gene, under the control of a heterologous Lentinula edodes gpd promoter. The efficiency of transformation is over 100 times higher than that previously reported in V. volvacea. Stable integration of the afp gene with 1-4 copy numbers was confirmed in all 10 randomly selected transgenic events by Southern blot analysis. The mitotic stability of the transformants was demonstrated after five successive transfers on PDA medium without selection pressure and the PCR analysis of basidiospores harvested from transformants.
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Transformation of Volvariella volvacea with a thermal hysteresis protein gene by particle bombardment
Wei sheng wu xue bao = Acta microbiologica Sinica, 2005Co-Authors: Li-qiong Guo, Jun-fang Lin, Sheng Xiong, Shou-cai ChenAbstract:A cDNA encoding a thermal hysteresis protein was isolated from the Swedish Arctic insect spruce budworm by RT-PCR amplification. Volvariella volvacea strain V34 was transformed with this cDNA through particle bombardment. PCR detection and Southern blotting analysis show that the thermal hysteresis protein gene is integrated into Volvariella volvacea genome. Cold stress assay reveals that transgenic Volvariella volvacea lines exhibit stronger cold tolerance than host strain. The morphological observation of transgenic Volvariella volvacea lines shows that growth rates of most Volvariella volvacea transformants are significantly slower than that of negative control strain. And hypha of most Volvariella volvacea tansformants is thinner than host strain's hypha. Transformant screening result indicates that three-round of selection procedure with first selection on PDSA solid selective medium followed by second and third selection in PDSB liquid selective medium is favorable to get genuine transformants and to eliminate false transformants. Cold tolerance assay of transgenic Volvariella volvacea F1 generation demonstrates that the progeny of transgenic Volvariella volvacea still possesses stronger cold tolerance than non-transformed host strain. This suggests that the cold tolerant characteristic of transgenic Volvariella volvacea is meiotically stable between generations.
W.k. Liu - One of the best experts on this subject based on the ideXlab platform.
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Volvariella volvacea lectin activates mouse T lymphocytes by a calcium dependent pathway.
Journal of cellular biochemistry, 2004Co-Authors: Stephen Cho Wing Sze, W.k. LiuAbstract:The immunomodulatory lectin, Volvariella volvacea lectin (VVL), isolated from the edible mushroom, Volvariella volvacea, has been shown to stimulate the expression of Th1 cytokines and the proliferative activity of mouse splenocytes (She et al. [1998]: Biochem Biophys Res Comm 247:106–111). In order to elucidate the mechanisms underlying these activities, we conducted a kinetic analysis of the early and late activation markers in mouse T lymphocytes: (1) flow cytometric analysis of calcium influx, (2) induction of activation molecules (CD25 and CD69), (3) expression and DNA-binding activity of the nuclear factor of activated T cells (NFAT), NFκB, and activation protein-1 (AP-1), (4) translational production of cytokines (interleukin-2 (IL-2) and interferon-γ (IFNγ)), and (5) cell proliferation by expression of proliferating cell nuclear antigen (PCNA) and tritiated thymidine incorporation. All results showed that VVL induced a rapid expression of CD69, CD25, NFAT, IL-2, and PCNA in a dose- and time-dependent manner, leading to lymphocyte proliferation. These effects brought about by VVL were more potent than those stimulated by equimolar concentrations of mitogenic lectin, concanavalin A (Con A). Cell activation and proliferation were mediated through a calcium-dependent pathway as demonstrated by a VVL-induced increase of intracellular calcium influx, and a proliferation inhibition by the Ca-dependent phosphatase calcineurin blocker—cyclosporin A (CsA). Taken all data together, VVL is a lectin which activates lymphocyte through successive calcium influx, nuclear localization of NFAT transcription factor, induction of activation markers, CD25 and CD69, intracellular cytokine production, and cell proliferation. © 2004 Wiley-Liss, Inc.
