The Experts below are selected from a list of 276 Experts worldwide ranked by ideXlab platform
Yan Zhao - One of the best experts on this subject based on the ideXlab platform.
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Induced resistance in peach fruit as treated by Pichia guilliermondii and their possible mechanism
International Journal of Food Properties, 2020Co-Authors: Yan Zhao, Bing ZhangAbstract:This research aims to assess the effect of Pichia guilliermondii treatment on the improved disease resistance of the peach fruit and to explore the biocontrol mechanisms. Infection rate and lesion ...
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Effects of hot air treatment in combination with Pichia guilliermondii on postharvest preservation of peach fruit
Journal of the science of food and agriculture, 2018Co-Authors: Yan Zhao, Jingjing YinAbstract:Background: Antagonistic yeast and hot air treatment are two promising methods for conferring resistance to pathogenic fungi. The study assessed the effectiveness of hot-air treatment (45 °C, 4 h) and antagonistic yeast (Pichia guilliermondii at 108 CFU mL-1 ) alone or in combination on the two major postharvest diseases (Rhizopus stolonifer and Penicillium expansum), as well as the quality and antioxidant parameters in harvested peaches.; Results: The combination of hot-air treatment and Pichia guilliermondii had notable inhibitory effects on infections in peach fruit wounds. In addition, the individual hot-air treatment or Pichia guilliermondii could improve quality indexes to varying degrees, but the combination of the above two treatments could achieve the highest efficacy. Furthermore, compared with other groups, the combined treatment induced the highest activities of superoxide dismutase and catalase, improved the content of total phenolics and reduced glutathione most obviously. Lastly, the most significant reductions in malondialdehyde content and relative electrical conductivity were observed in the combination-treated fruit.; Conclusions: The combined treatment could control fungal diseases, besides delay the decline of quality and antioxidant parameters, so as to achieve the purpose of fresh keeping for harvested peach fruit. © 2018 Society of Chemical Industry.; © 2018 Society of Chemical Industry.
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effects of Pichia guilliermondii and hot air treatment on the postharvest preservation of red fuji apple quality attributes
Journal of Food Protection, 2018Co-Authors: Yan Zhao, Jingjing YinAbstract:The effects of individual and combined Pichia guilliermondii (at 1 × 108 CFU mL-1) and hot air (at 38°C for 96 h) treatments on the three major postharvest diseases Botrytis cinerea, Penicillium expansum, and Colletotrichum gloeosporioides, as well as the quality and antioxidant content of Red Fuji ( Malus pumila var. domestica) apple fruit, were investigated in this work. Results suggested that the combined hot air and antagonistic yeast ( P. guilliermondii) treatment effectively and completely inhibited the infection of apple fruit wounds by the three major postharvest diseases. Furthermore, apple fruit treated with antagonistic yeast or heat alone maintained better quality, which included mass loss, firmness, solid/acid ratio, and ascorbic acid content, than the control. The combination of the two treatments yielded the optimum apple quality. Moreover, the combined hot air and P. guilliermondii treatment also maintained or enhanced the antioxidative enzyme activities and total phenolic content of apple fruit. All results demonstrated that the combined antagonistic yeast and hot air treatment maintained the postharvest freshness of apple fruit.
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Efficacy of preharvest spraying with Pichia guilliermondii on postharvest decay and quality of cherry tomato fruit during storage
African Journal of Biotechnology, 2011Co-Authors: Yan Zhao, Ruolan Wang, Kunlun LiuAbstract:This study investigated the effects of preharvest spraying with Pichia guilliermondii on postharvest natural decay of cherry tomato fruit, and evaluated the quality attributes during storage. Preharvest spraying with P. guilliermondii significantly decreased the decay index. Moreover, the efficacy of this biological control was positively correlated with spraying frequency. However, preharvest spraying with P. guilliermondii and spraying frequency did not significantly affect fruit quality attributes regardless of whether the cherry tomato fruit was grown or stored after harvest. This observation indicates that preharvest spraying with P. guilliermondii does not influence the quality attributes of the fruit. In addition, the activities of peroxidase (POD), phenylalanine ammonia-lyase (PAL), and β-1,3-glucanase increased in all P. guilliermondii treatments, suggesting a positive correlation with spraying frequency. The results suggest that cherry tomato fruit is capable of responding to preharvest spraying with P. guilliermondii , which can activate its defensive enzymes and thus induce host disease resistance. Key words: Preharvest, Pichia guilliermondii, cherry tomato fruit, decay, quality.
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effect of hot air treatment in combination with Pichia guilliermondii on postharvest anthracnose rot of loquat fruit
Postharvest Biology and Technology, 2010Co-Authors: Fengjuan Liu, Yan Zhao, Xingfeng Shao, Yuepeng Hou, Xiurong ZouAbstract:Abstract Effect of heat treatment (hot air at 38 °C for 36 h) and Pichia guilliermondii ( P. guilliermondii ), either alone or in combination, against anthracnose rot caused by Colletotrichum acutatum ( C. acutatum ), in loquat fruit was investigated. Results showed that the combined treatment significantly reduced natural decay, and disease incidence and lesion diameter in artificially inoculated fruit. Fruit given the combined treatment maintained low activities of catalase (CAT) during the early storage period, but CAT and superoxide dismutase (SOD) activities both rose later in storage. This corresponded with a high level of H 2 O 2 in the early storage period and a lower level of H 2 O 2 in the later period. At the same time, induced activity of phenylalanine ammonia-lyase (PAL) and β-1,3-glucanase stimulated synthesis of lignin, thus eliciting disease resistance. Moreover, the combined treatment significantly inhibited mycelial growth and spore germination of C. acutatum , reducing anthracnose rot of loquat fruit.
Abu Bakar Salleh - One of the best experts on this subject based on the ideXlab platform.
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optimization of physical conditions for the production of thermostable t1 lipase in Pichia guilliermondii strain so using response surface methodology
BMC Biotechnology, 2017Co-Authors: Mary Ladidi Abu, Hisham Mohd Nooh, Siti Nurbaya Oslan, Abu Bakar SallehAbstract:Pichia guilliermondii was found capable of expressing the recombinant thermostable lipase without methanol under the control of methanol dependent alcohol oxidase 1 promoter (AOXp 1). In this study, statistical approaches were employed for the screening and optimisation of physical conditions for T1 lipase production in P. guilliermondii. The screening of six physical conditions by Plackett-Burman Design has identified pH, inoculum size and incubation time as exerting significant effects on lipase production. These three conditions were further optimised using, Box-Behnken Design of Response Surface Methodology, which predicted an optimum medium comprising pH 6, 24 h incubation time and 2% inoculum size. T1 lipase activity of 2.0 U/mL was produced with a biomass of OD600 23.0. The process of using RSM for optimisation yielded a 3-fold increase of T1 lipase over medium before optimisation. Therefore, this result has proven that T1 lipase can be produced at a higher yield in P. guilliermondii.
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Optimization of physical conditions for the production of thermostable T1 lipase in Pichia guilliermondii strain SO using response surface methodology
BMC, 2017Co-Authors: Mary Ladidi Abu, Hisham Mohd Nooh, Siti Nurbaya Oslan, Abu Bakar SallehAbstract:Abstract Background Pichia guilliermondii was found capable of expressing the recombinant thermostable lipase without methanol under the control of methanol dependent alcohol oxidase 1 promoter (AOXp 1). In this study, statistical approaches were employed for the screening and optimisation of physical conditions for T1 lipase production in P. guilliermondii. Result The screening of six physical conditions by Plackett-Burman Design has identified pH, inoculum size and incubation time as exerting significant effects on lipase production. These three conditions were further optimised using, Box-Behnken Design of Response Surface Methodology, which predicted an optimum medium comprising pH 6, 24 h incubation time and 2% inoculum size. T1 lipase activity of 2.0 U/mL was produced with a biomass of OD600 23.0. Conclusion The process of using RSM for optimisation yielded a 3-fold increase of T1 lipase over medium before optimisation. Therefore, this result has proven that T1 lipase can be produced at a higher yield in P. guilliermondii
Mary Ladidi Abu - One of the best experts on this subject based on the ideXlab platform.
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optimization of physical conditions for the production of thermostable t1 lipase in Pichia guilliermondii strain so using response surface methodology
BMC Biotechnology, 2017Co-Authors: Mary Ladidi Abu, Hisham Mohd Nooh, Siti Nurbaya Oslan, Abu Bakar SallehAbstract:Pichia guilliermondii was found capable of expressing the recombinant thermostable lipase without methanol under the control of methanol dependent alcohol oxidase 1 promoter (AOXp 1). In this study, statistical approaches were employed for the screening and optimisation of physical conditions for T1 lipase production in P. guilliermondii. The screening of six physical conditions by Plackett-Burman Design has identified pH, inoculum size and incubation time as exerting significant effects on lipase production. These three conditions were further optimised using, Box-Behnken Design of Response Surface Methodology, which predicted an optimum medium comprising pH 6, 24 h incubation time and 2% inoculum size. T1 lipase activity of 2.0 U/mL was produced with a biomass of OD600 23.0. The process of using RSM for optimisation yielded a 3-fold increase of T1 lipase over medium before optimisation. Therefore, this result has proven that T1 lipase can be produced at a higher yield in P. guilliermondii.
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Optimization of physical conditions for the production of thermostable T1 lipase in Pichia guilliermondii strain SO using response surface methodology
BMC, 2017Co-Authors: Mary Ladidi Abu, Hisham Mohd Nooh, Siti Nurbaya Oslan, Abu Bakar SallehAbstract:Abstract Background Pichia guilliermondii was found capable of expressing the recombinant thermostable lipase without methanol under the control of methanol dependent alcohol oxidase 1 promoter (AOXp 1). In this study, statistical approaches were employed for the screening and optimisation of physical conditions for T1 lipase production in P. guilliermondii. Result The screening of six physical conditions by Plackett-Burman Design has identified pH, inoculum size and incubation time as exerting significant effects on lipase production. These three conditions were further optimised using, Box-Behnken Design of Response Surface Methodology, which predicted an optimum medium comprising pH 6, 24 h incubation time and 2% inoculum size. T1 lipase activity of 2.0 U/mL was produced with a biomass of OD600 23.0. Conclusion The process of using RSM for optimisation yielded a 3-fold increase of T1 lipase over medium before optimisation. Therefore, this result has proven that T1 lipase can be produced at a higher yield in P. guilliermondii
M.e. Rodríguez - One of the best experts on this subject based on the ideXlab platform.
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characterization of α rhamnosidase activity from a patagonian Pichia guilliermondii wine strain
Journal of Applied Microbiology, 2010Co-Authors: Christian A. Lopes, M.e. Rodríguez, Salvador Vallés, Adriana C. CaballeroAbstract:Aims: The purpose of this study was to characterize the α-l-rhamnosidase of Pichia guilliermondii NPCC1053 indigenous wine strain from North-Patagonian region. Methods and Results: The optimization of yeast culture conditions was carried out and the effects of oenological parameters on α-l-rhamnosidase activity were evaluated. Additionally, the effect of direct contact with must and wine on α-l-rhamnosidase activity was assayed. This strain showed an intracellular inducible α-l-rhamnosidase activity. This enzyme was active at pH, glucose and SO2 concentrations usually found at the beginning of the fermentation as well as retained high levels of activity after 24 h of incubation in must. Furthermore, P. guilliermondiiα-l-rhamnosidase was able to release monoterpenols and alcohols from grape glycosidic extracts. Conclusions: The α-l-rhamnosidase belonging to P. guilliermondii indigenous wine yeast strain showed mainly an intracellular location and evidenced interesting oenological characteristics. Significance and Impact of the Study: This study contributes to the knowledge of α-l-rhamnosidases from yeast origin because at present, there are few reports about this enzymatic activity in these micro-organisms. In addition, this work is relevant to the regional wine industry considering that this enzyme could be used in the production of more aromatic young wines.
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Characterization of α‐rhamnosidase activity from a Patagonian Pichia guilliermondii wine strain
Journal of applied microbiology, 2010Co-Authors: M.e. Rodríguez, Christian A. Lopes, Salvador Vallés, Adriana C. CaballeroAbstract:Aims: The purpose of this study was to characterize the α-l-rhamnosidase of Pichia guilliermondii NPCC1053 indigenous wine strain from North-Patagonian region. Methods and Results: The optimization of yeast culture conditions was carried out and the effects of oenological parameters on α-l-rhamnosidase activity were evaluated. Additionally, the effect of direct contact with must and wine on α-l-rhamnosidase activity was assayed. This strain showed an intracellular inducible α-l-rhamnosidase activity. This enzyme was active at pH, glucose and SO2 concentrations usually found at the beginning of the fermentation as well as retained high levels of activity after 24 h of incubation in must. Furthermore, P. guilliermondiiα-l-rhamnosidase was able to release monoterpenols and alcohols from grape glycosidic extracts. Conclusions: The α-l-rhamnosidase belonging to P. guilliermondii indigenous wine yeast strain showed mainly an intracellular location and evidenced interesting oenological characteristics. Significance and Impact of the Study: This study contributes to the knowledge of α-l-rhamnosidases from yeast origin because at present, there are few reports about this enzymatic activity in these micro-organisms. In addition, this work is relevant to the regional wine industry considering that this enzyme could be used in the production of more aromatic young wines.
Adriana C. Caballero - One of the best experts on this subject based on the ideXlab platform.
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characterization of α rhamnosidase activity from a patagonian Pichia guilliermondii wine strain
Journal of Applied Microbiology, 2010Co-Authors: Christian A. Lopes, M.e. Rodríguez, Salvador Vallés, Adriana C. CaballeroAbstract:Aims: The purpose of this study was to characterize the α-l-rhamnosidase of Pichia guilliermondii NPCC1053 indigenous wine strain from North-Patagonian region. Methods and Results: The optimization of yeast culture conditions was carried out and the effects of oenological parameters on α-l-rhamnosidase activity were evaluated. Additionally, the effect of direct contact with must and wine on α-l-rhamnosidase activity was assayed. This strain showed an intracellular inducible α-l-rhamnosidase activity. This enzyme was active at pH, glucose and SO2 concentrations usually found at the beginning of the fermentation as well as retained high levels of activity after 24 h of incubation in must. Furthermore, P. guilliermondiiα-l-rhamnosidase was able to release monoterpenols and alcohols from grape glycosidic extracts. Conclusions: The α-l-rhamnosidase belonging to P. guilliermondii indigenous wine yeast strain showed mainly an intracellular location and evidenced interesting oenological characteristics. Significance and Impact of the Study: This study contributes to the knowledge of α-l-rhamnosidases from yeast origin because at present, there are few reports about this enzymatic activity in these micro-organisms. In addition, this work is relevant to the regional wine industry considering that this enzyme could be used in the production of more aromatic young wines.
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Characterization of α‐rhamnosidase activity from a Patagonian Pichia guilliermondii wine strain
Journal of applied microbiology, 2010Co-Authors: M.e. Rodríguez, Christian A. Lopes, Salvador Vallés, Adriana C. CaballeroAbstract:Aims: The purpose of this study was to characterize the α-l-rhamnosidase of Pichia guilliermondii NPCC1053 indigenous wine strain from North-Patagonian region. Methods and Results: The optimization of yeast culture conditions was carried out and the effects of oenological parameters on α-l-rhamnosidase activity were evaluated. Additionally, the effect of direct contact with must and wine on α-l-rhamnosidase activity was assayed. This strain showed an intracellular inducible α-l-rhamnosidase activity. This enzyme was active at pH, glucose and SO2 concentrations usually found at the beginning of the fermentation as well as retained high levels of activity after 24 h of incubation in must. Furthermore, P. guilliermondiiα-l-rhamnosidase was able to release monoterpenols and alcohols from grape glycosidic extracts. Conclusions: The α-l-rhamnosidase belonging to P. guilliermondii indigenous wine yeast strain showed mainly an intracellular location and evidenced interesting oenological characteristics. Significance and Impact of the Study: This study contributes to the knowledge of α-l-rhamnosidases from yeast origin because at present, there are few reports about this enzymatic activity in these micro-organisms. In addition, this work is relevant to the regional wine industry considering that this enzyme could be used in the production of more aromatic young wines.