The Experts below are selected from a list of 309 Experts worldwide ranked by ideXlab platform
Yujin Cao - One of the best experts on this subject based on the ideXlab platform.
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improving Phloroglucinol tolerance and production in escherichia coli by groesl overexpression
Microbial Cell Factories, 2017Co-Authors: Rubing Zhang, Yujin Cao, Mo Xian, Wei Liu, Huizhou LiuAbstract:Phloroglucinol is an important chemical which has been successfully produced by engineered Escherichia coli. However, the toxicity of Phloroglucinol can enormously inhibit E. coli cell growth and viability, and the productivity is still too low and not economically feasible for industrial applications. Therefore, strain tolerance to toxic metabolites remains a key issue during the production of chemicals using biological processes. In the present work, we examined the impact of the native GroESL chaperone system with different overexpression levels on Phloroglucinol tolerance and production in E. coli. The groESL gene was cloned into an expression vector, of which expression level was regulated by three different promoters (natural, tac and T7 promoter). Strain tolerance was evaluated employing viable cell counts and Phloroglucinol production. In comparison with the control strain, all GroESL overexpressing strains showed good characteristics in cell viability and Phloroglucinol synthesis. Strain which overexpressed GroESL under tac promoter was found to show the best tolerance in all of those tested, resulting in a 3.19-fold increase in viable cell numbers compared with control strain of agar-plate culture under the condition of 0.7 g/L Phloroglucinol, and a 39.5% increase in Phloroglucinol production under fed-batch fermentation. This engineered strain finally accumulated Phloroglucinol up to 5.3 g/L in the fed-batch cultivation 10 h after induction, and the productivity was 0.53 g/L/h. To date, the highest Phloroglucinol production was achieved in this work compared with the previous reports, which is promising to make the bioprocess feasible from the economical point. The data show that appropriate expression level of GroESL plays a critical role in improving Phloroglucinol tolerance and production in E. coli, and maybe involve in controlling some aspects of the stress response system through upregulation of GroESL. GroESL overexpression is therefore a feasible and efficient approach for improvement of E. coli tolerance.
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An in vitro synthetic biosystem based on acetate for production of Phloroglucinol.
BMC biotechnology, 2017Co-Authors: Rubing Zhang, Yujin Cao, Mo Xian, Wei Liu, Huizhou LiuAbstract:Phloroglucinol is an important chemical, and the biosynthesis processes which can convert glucose to Phloroglucinol have been established. However, due to approximate 80% of the glucose being transformed into undesirable by-products and biomass, this biosynthesis process only shows a low yield with the highest value of about 0.20 g/g. The industrial applications are usually hindered by the low current productivity and yield and also by the high costs. Generally, several different aspects limit the development of Phloroglucinol biosynthesis. The yield of Phloroglucinol is one of the most important parameters for its bioconversion especially from economic and ecological points of view. The in vitro biosynthesis of bio-based chemicals, is a flexible alternative with potentially high-yield to in vivo biosynthetic technology. By comparing the activity of acetyl-CoA synthetase (ACS) from Escherichia coli and Acetobacter pasteurianus, the highly active ACS2 was identified in A. pasteurianus. Acetyl-CoA carboxylase (ACC) from Acinetobacter calcoaceticus and Phloroglucinol synthase (PhlD) from Pseudomonas fluorescens pf-5 were expressed and purified. Acetate was successfully transformed into Phloroglucinol by the combined activity of above-mentioned enzymes and required cofactor. After optimization of the in vitro reaction system, Phloroglucinol was then produced with a yield of nearly 0.64 g Phloroglucinol/g acetic acid, which was equal to 91.43% of the theoretically possible maximum. In this work, a novel in vitro synthetic system for a highly efficient production of Phloroglucinol from acetate was demonstrated. The system’s performance suggests that in vitro synthesis of Phloroglucinol has some advantages and is potential to become a feasible industrial alternative. Based on the results presented herewith, it is believed that in vitro biosystem will provide a feasible option for production of important industrial chemicals from acetate, which could work as a versatile biosynthetic platform.
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An in vitro synthetic biosystem based on acetate for production of Phloroglucinol
BMC, 2017Co-Authors: Rubing Zhang, Yujin Cao, Mo Xian, Wei Liu, Huizhou LiuAbstract:Abstract Background Phloroglucinol is an important chemical, and the biosynthesis processes which can convert glucose to Phloroglucinol have been established. However, due to approximate 80% of the glucose being transformed into undesirable by-products and biomass, this biosynthesis process only shows a low yield with the highest value of about 0.20 g/g. The industrial applications are usually hindered by the low current productivity and yield and also by the high costs. Generally, several different aspects limit the development of Phloroglucinol biosynthesis. The yield of Phloroglucinol is one of the most important parameters for its bioconversion especially from economic and ecological points of view. The in vitro biosynthesis of bio-based chemicals, is a flexible alternative with potentially high-yield to in vivo biosynthetic technology. Results By comparing the activity of acetyl-CoA synthetase (ACS) from Escherichia coli and Acetobacter pasteurianus, the highly active ACS2 was identified in A. pasteurianus. Acetyl-CoA carboxylase (ACC) from Acinetobacter calcoaceticus and Phloroglucinol synthase (PhlD) from Pseudomonas fluorescens pf-5 were expressed and purified. Acetate was successfully transformed into Phloroglucinol by the combined activity of above-mentioned enzymes and required cofactor. After optimization of the in vitro reaction system, Phloroglucinol was then produced with a yield of nearly 0.64 g Phloroglucinol/g acetic acid, which was equal to 91.43% of the theoretically possible maximum. Conclusions In this work, a novel in vitro synthetic system for a highly efficient production of Phloroglucinol from acetate was demonstrated. The system’s performance suggests that in vitro synthesis of Phloroglucinol has some advantages and is potential to become a feasible industrial alternative. Based on the results presented herewith, it is believed that in vitro biosystem will provide a feasible option for production of important industrial chemicals from acetate, which could work as a versatile biosynthetic platform
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biosynthesis of Phloroglucinol compounds in microorganisms review
Applied Microbiology and Biotechnology, 2012Co-Authors: Fang Yang, Yujin CaoAbstract:Phloroglucinol derivatives are a major class of secondary metabolites of wide occurrence in biological systems. In the bacteria kingdom, these compounds can only be synthesized by some species of Pseudomonads. Pseudomonas spp. could produce 2,4-diacetylPhloroglucinol (DAPG) that plays an important role in the biological control of many plant pathogens. In this review, we summarize knowledge about synthesis of Phloroglucinol compounds based on the DAPG biosynthetic pathway. Recent advances that have been made in understanding Phloroglucinol compound biosynthesis and regulation are highlighted. From these studies, researchers have identified the biosynthesis pathway of DAPG. Most of the genes involved in the biosynthesis pathway have been cloned and characterized. Additionally, heterologous systems of the model microorganism Escherichia coli are constructed to produce Phloroglucinol. Although further work is still required, a full understanding of Phloroglucinol compound biosynthesis is almost within reach. This review also suggests new directions and attempts to gain some insights for better understanding of the biosynthesis and regulation of DAPG. The combination of traditional biochemistry and molecular biology with new systems biology and synthetic biology tools will provide a better view of Phloroglucinol compound biosynthesis and a greater potential of microbial production.
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Biosynthesis of Phloroglucinol compounds in microorganisms—review
Applied microbiology and biotechnology, 2011Co-Authors: Fang Yang, Yujin CaoAbstract:Phloroglucinol derivatives are a major class of secondary metabolites of wide occurrence in biological systems. In the bacteria kingdom, these compounds can only be synthesized by some species of Pseudomonads. Pseudomonas spp. could produce 2,4-diacetylPhloroglucinol (DAPG) that plays an important role in the biological control of many plant pathogens. In this review, we summarize knowledge about synthesis of Phloroglucinol compounds based on the DAPG biosynthetic pathway. Recent advances that have been made in understanding Phloroglucinol compound biosynthesis and regulation are highlighted. From these studies, researchers have identified the biosynthesis pathway of DAPG. Most of the genes involved in the biosynthesis pathway have been cloned and characterized. Additionally, heterologous systems of the model microorganism Escherichia coli are constructed to produce Phloroglucinol. Although further work is still required, a full understanding of Phloroglucinol compound biosynthesis is almost within reach. This review also suggests new directions and attempts to gain some insights for better understanding of the biosynthesis and regulation of DAPG. The combination of traditional biochemistry and molecular biology with new systems biology and synthetic biology tools will provide a better view of Phloroglucinol compound biosynthesis and a greater potential of microbial production.
Huizhou Liu - One of the best experts on this subject based on the ideXlab platform.
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improving Phloroglucinol tolerance and production in escherichia coli by groesl overexpression
Microbial Cell Factories, 2017Co-Authors: Rubing Zhang, Yujin Cao, Mo Xian, Wei Liu, Huizhou LiuAbstract:Phloroglucinol is an important chemical which has been successfully produced by engineered Escherichia coli. However, the toxicity of Phloroglucinol can enormously inhibit E. coli cell growth and viability, and the productivity is still too low and not economically feasible for industrial applications. Therefore, strain tolerance to toxic metabolites remains a key issue during the production of chemicals using biological processes. In the present work, we examined the impact of the native GroESL chaperone system with different overexpression levels on Phloroglucinol tolerance and production in E. coli. The groESL gene was cloned into an expression vector, of which expression level was regulated by three different promoters (natural, tac and T7 promoter). Strain tolerance was evaluated employing viable cell counts and Phloroglucinol production. In comparison with the control strain, all GroESL overexpressing strains showed good characteristics in cell viability and Phloroglucinol synthesis. Strain which overexpressed GroESL under tac promoter was found to show the best tolerance in all of those tested, resulting in a 3.19-fold increase in viable cell numbers compared with control strain of agar-plate culture under the condition of 0.7 g/L Phloroglucinol, and a 39.5% increase in Phloroglucinol production under fed-batch fermentation. This engineered strain finally accumulated Phloroglucinol up to 5.3 g/L in the fed-batch cultivation 10 h after induction, and the productivity was 0.53 g/L/h. To date, the highest Phloroglucinol production was achieved in this work compared with the previous reports, which is promising to make the bioprocess feasible from the economical point. The data show that appropriate expression level of GroESL plays a critical role in improving Phloroglucinol tolerance and production in E. coli, and maybe involve in controlling some aspects of the stress response system through upregulation of GroESL. GroESL overexpression is therefore a feasible and efficient approach for improvement of E. coli tolerance.
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An in vitro synthetic biosystem based on acetate for production of Phloroglucinol.
BMC biotechnology, 2017Co-Authors: Rubing Zhang, Yujin Cao, Mo Xian, Wei Liu, Huizhou LiuAbstract:Phloroglucinol is an important chemical, and the biosynthesis processes which can convert glucose to Phloroglucinol have been established. However, due to approximate 80% of the glucose being transformed into undesirable by-products and biomass, this biosynthesis process only shows a low yield with the highest value of about 0.20 g/g. The industrial applications are usually hindered by the low current productivity and yield and also by the high costs. Generally, several different aspects limit the development of Phloroglucinol biosynthesis. The yield of Phloroglucinol is one of the most important parameters for its bioconversion especially from economic and ecological points of view. The in vitro biosynthesis of bio-based chemicals, is a flexible alternative with potentially high-yield to in vivo biosynthetic technology. By comparing the activity of acetyl-CoA synthetase (ACS) from Escherichia coli and Acetobacter pasteurianus, the highly active ACS2 was identified in A. pasteurianus. Acetyl-CoA carboxylase (ACC) from Acinetobacter calcoaceticus and Phloroglucinol synthase (PhlD) from Pseudomonas fluorescens pf-5 were expressed and purified. Acetate was successfully transformed into Phloroglucinol by the combined activity of above-mentioned enzymes and required cofactor. After optimization of the in vitro reaction system, Phloroglucinol was then produced with a yield of nearly 0.64 g Phloroglucinol/g acetic acid, which was equal to 91.43% of the theoretically possible maximum. In this work, a novel in vitro synthetic system for a highly efficient production of Phloroglucinol from acetate was demonstrated. The system’s performance suggests that in vitro synthesis of Phloroglucinol has some advantages and is potential to become a feasible industrial alternative. Based on the results presented herewith, it is believed that in vitro biosystem will provide a feasible option for production of important industrial chemicals from acetate, which could work as a versatile biosynthetic platform.
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Efficient conversion of acetate into Phloroglucinol by recombinant Escherichia coli
RSC Advances, 2017Co-Authors: Mo Xian, Huizhou LiuAbstract:Phloroglucinol, an important fine chemical, was attempted to be produced by a recombinant Escherichia coli, using acetate, a less costly feedstock, as a alternative carbon source. Phloroglucinol was significantly produced by assembling an acetate assimilation pathway and Phloroglucinol biosynthetic pathway in an engineered Escherichia coli strain. Subsequently, the culture conditions were optimized to enhance Phloroglucinol production with a maximum titer of 554 mg L−1. Finally, fed-batch fermentation of Phloroglucinol was evaluated using the optimized culture conditions, and reached a maximum concentration of 1.20 g L−1. The productivity (0.74 g per g DCW) and yield (0.18 g per g acetate) increased by 3.20-fold and 1.64-fold, respectively, compared with the data using glucose as the carbon source. Therefore, the engineered E. coli cells can be directly emplored for Phloroglucinol biosynthesis from acetate with better atom economy and lower cost.
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An in vitro synthetic biosystem based on acetate for production of Phloroglucinol
BMC, 2017Co-Authors: Rubing Zhang, Yujin Cao, Mo Xian, Wei Liu, Huizhou LiuAbstract:Abstract Background Phloroglucinol is an important chemical, and the biosynthesis processes which can convert glucose to Phloroglucinol have been established. However, due to approximate 80% of the glucose being transformed into undesirable by-products and biomass, this biosynthesis process only shows a low yield with the highest value of about 0.20 g/g. The industrial applications are usually hindered by the low current productivity and yield and also by the high costs. Generally, several different aspects limit the development of Phloroglucinol biosynthesis. The yield of Phloroglucinol is one of the most important parameters for its bioconversion especially from economic and ecological points of view. The in vitro biosynthesis of bio-based chemicals, is a flexible alternative with potentially high-yield to in vivo biosynthetic technology. Results By comparing the activity of acetyl-CoA synthetase (ACS) from Escherichia coli and Acetobacter pasteurianus, the highly active ACS2 was identified in A. pasteurianus. Acetyl-CoA carboxylase (ACC) from Acinetobacter calcoaceticus and Phloroglucinol synthase (PhlD) from Pseudomonas fluorescens pf-5 were expressed and purified. Acetate was successfully transformed into Phloroglucinol by the combined activity of above-mentioned enzymes and required cofactor. After optimization of the in vitro reaction system, Phloroglucinol was then produced with a yield of nearly 0.64 g Phloroglucinol/g acetic acid, which was equal to 91.43% of the theoretically possible maximum. Conclusions In this work, a novel in vitro synthetic system for a highly efficient production of Phloroglucinol from acetate was demonstrated. The system’s performance suggests that in vitro synthesis of Phloroglucinol has some advantages and is potential to become a feasible industrial alternative. Based on the results presented herewith, it is believed that in vitro biosystem will provide a feasible option for production of important industrial chemicals from acetate, which could work as a versatile biosynthetic platform
Tiana Tasca - One of the best experts on this subject based on the ideXlab platform.
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The anti‐Trichomonas vaginalis Phloroglucinol derivative isoaustrobrasilol B modulates extracellular nucleotide hydrolysis
Chemical biology & drug design, 2017Co-Authors: Camila Braz Menezes, Gilsane Lino Von Poser, Graziela Vargas Rigo, Henrique Bridi, Danielle Da Silva Trentin, Alexandre José Macedo, Tiana TascaAbstract:Trichomonas vaginalis causes trichomoniasis, a neglected sexually transmitted disease. Due to severe health consequences and treatment failure, new therapeutic alternatives are crucial. Phloroglucinols from southern Brazilian Hypericum species demonstrated anti-T. vaginalis and anti-Leishmania amazonensis activities. The modulation of biochemical pathways involved in the control of inflammatory response by ectonucleotidases, NTPDase, and ecto-5′-nucleotidase represents new targets for combating protozoa. This study investigated the activity of Phloroglucinol derivatives of Hypericum species from southern Brazil against T. vaginalis as well as its ability on modulating parasite ectonucleotidases and, consequently, immune parameters through ATP and adenosine effects. Phloroglucinol derivatives screening revealed activity for isoaustrobrasilol B (IC50 38 μm) with no hemolytic activity. Although the most active compound induced cytotoxicity against a mammalian cell lineage, the in vivo model evidenced absence of toxicity. Isoaustrobrasilol B significantly inhibited NTPDase and ecto-5′-nucleotidase activities, and the immune modulation attributed to extracellular nucleotide accumulation was evaluated. The production of ROS and IL-6 by T. vaginalis-stimulated neutrophils was not affected by the treatment. Conversely, IL-8 levels were significantly enhanced. The associative mechanism of trophozoites death and ectonucleotidases modulation by isoaustrobrasilol B may increase the susceptibility of T. vaginalis to host innate immune cell like neutrophils consequently, contributing to parasite clearance.
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the anti trichomonas vaginalis Phloroglucinol derivative isoaustrobrasilol b modulates extracellular nucleotide hydrolysis
Chemical Biology & Drug Design, 2017Co-Authors: Camila Braz Menezes, Gilsane Lino Von Poser, Graziela Vargas Rigo, Henrique Bridi, Danielle Da Silva Trentin, Alexandre José Macedo, Tiana TascaAbstract:Trichomonas vaginalis causes trichomoniasis, a neglected sexually transmitted disease. Due to severe health consequences and treatment failure, new therapeutic alternatives are crucial. Phloroglucinols from southern Brazilian Hypericum species demonstrated anti-T. vaginalis and anti-Leishmania amazonensis activities. The modulation of biochemical pathways involved in the control of inflammatory response by ectonucleotidases, NTPDase, and ecto-5′-nucleotidase represents new targets for combating protozoa. This study investigated the activity of Phloroglucinol derivatives of Hypericum species from southern Brazil against T. vaginalis as well as its ability on modulating parasite ectonucleotidases and, consequently, immune parameters through ATP and adenosine effects. Phloroglucinol derivatives screening revealed activity for isoaustrobrasilol B (IC50 38 μm) with no hemolytic activity. Although the most active compound induced cytotoxicity against a mammalian cell lineage, the in vivo model evidenced absence of toxicity. Isoaustrobrasilol B significantly inhibited NTPDase and ecto-5′-nucleotidase activities, and the immune modulation attributed to extracellular nucleotide accumulation was evaluated. The production of ROS and IL-6 by T. vaginalis-stimulated neutrophils was not affected by the treatment. Conversely, IL-8 levels were significantly enhanced. The associative mechanism of trophozoites death and ectonucleotidases modulation by isoaustrobrasilol B may increase the susceptibility of T. vaginalis to host innate immune cell like neutrophils consequently, contributing to parasite clearance.
Mo Xian - One of the best experts on this subject based on the ideXlab platform.
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improving Phloroglucinol tolerance and production in escherichia coli by groesl overexpression
Microbial Cell Factories, 2017Co-Authors: Rubing Zhang, Yujin Cao, Mo Xian, Wei Liu, Huizhou LiuAbstract:Phloroglucinol is an important chemical which has been successfully produced by engineered Escherichia coli. However, the toxicity of Phloroglucinol can enormously inhibit E. coli cell growth and viability, and the productivity is still too low and not economically feasible for industrial applications. Therefore, strain tolerance to toxic metabolites remains a key issue during the production of chemicals using biological processes. In the present work, we examined the impact of the native GroESL chaperone system with different overexpression levels on Phloroglucinol tolerance and production in E. coli. The groESL gene was cloned into an expression vector, of which expression level was regulated by three different promoters (natural, tac and T7 promoter). Strain tolerance was evaluated employing viable cell counts and Phloroglucinol production. In comparison with the control strain, all GroESL overexpressing strains showed good characteristics in cell viability and Phloroglucinol synthesis. Strain which overexpressed GroESL under tac promoter was found to show the best tolerance in all of those tested, resulting in a 3.19-fold increase in viable cell numbers compared with control strain of agar-plate culture under the condition of 0.7 g/L Phloroglucinol, and a 39.5% increase in Phloroglucinol production under fed-batch fermentation. This engineered strain finally accumulated Phloroglucinol up to 5.3 g/L in the fed-batch cultivation 10 h after induction, and the productivity was 0.53 g/L/h. To date, the highest Phloroglucinol production was achieved in this work compared with the previous reports, which is promising to make the bioprocess feasible from the economical point. The data show that appropriate expression level of GroESL plays a critical role in improving Phloroglucinol tolerance and production in E. coli, and maybe involve in controlling some aspects of the stress response system through upregulation of GroESL. GroESL overexpression is therefore a feasible and efficient approach for improvement of E. coli tolerance.
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An in vitro synthetic biosystem based on acetate for production of Phloroglucinol.
BMC biotechnology, 2017Co-Authors: Rubing Zhang, Yujin Cao, Mo Xian, Wei Liu, Huizhou LiuAbstract:Phloroglucinol is an important chemical, and the biosynthesis processes which can convert glucose to Phloroglucinol have been established. However, due to approximate 80% of the glucose being transformed into undesirable by-products and biomass, this biosynthesis process only shows a low yield with the highest value of about 0.20 g/g. The industrial applications are usually hindered by the low current productivity and yield and also by the high costs. Generally, several different aspects limit the development of Phloroglucinol biosynthesis. The yield of Phloroglucinol is one of the most important parameters for its bioconversion especially from economic and ecological points of view. The in vitro biosynthesis of bio-based chemicals, is a flexible alternative with potentially high-yield to in vivo biosynthetic technology. By comparing the activity of acetyl-CoA synthetase (ACS) from Escherichia coli and Acetobacter pasteurianus, the highly active ACS2 was identified in A. pasteurianus. Acetyl-CoA carboxylase (ACC) from Acinetobacter calcoaceticus and Phloroglucinol synthase (PhlD) from Pseudomonas fluorescens pf-5 were expressed and purified. Acetate was successfully transformed into Phloroglucinol by the combined activity of above-mentioned enzymes and required cofactor. After optimization of the in vitro reaction system, Phloroglucinol was then produced with a yield of nearly 0.64 g Phloroglucinol/g acetic acid, which was equal to 91.43% of the theoretically possible maximum. In this work, a novel in vitro synthetic system for a highly efficient production of Phloroglucinol from acetate was demonstrated. The system’s performance suggests that in vitro synthesis of Phloroglucinol has some advantages and is potential to become a feasible industrial alternative. Based on the results presented herewith, it is believed that in vitro biosystem will provide a feasible option for production of important industrial chemicals from acetate, which could work as a versatile biosynthetic platform.
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Efficient conversion of acetate into Phloroglucinol by recombinant Escherichia coli
RSC Advances, 2017Co-Authors: Mo Xian, Huizhou LiuAbstract:Phloroglucinol, an important fine chemical, was attempted to be produced by a recombinant Escherichia coli, using acetate, a less costly feedstock, as a alternative carbon source. Phloroglucinol was significantly produced by assembling an acetate assimilation pathway and Phloroglucinol biosynthetic pathway in an engineered Escherichia coli strain. Subsequently, the culture conditions were optimized to enhance Phloroglucinol production with a maximum titer of 554 mg L−1. Finally, fed-batch fermentation of Phloroglucinol was evaluated using the optimized culture conditions, and reached a maximum concentration of 1.20 g L−1. The productivity (0.74 g per g DCW) and yield (0.18 g per g acetate) increased by 3.20-fold and 1.64-fold, respectively, compared with the data using glucose as the carbon source. Therefore, the engineered E. coli cells can be directly emplored for Phloroglucinol biosynthesis from acetate with better atom economy and lower cost.
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An in vitro synthetic biosystem based on acetate for production of Phloroglucinol
BMC, 2017Co-Authors: Rubing Zhang, Yujin Cao, Mo Xian, Wei Liu, Huizhou LiuAbstract:Abstract Background Phloroglucinol is an important chemical, and the biosynthesis processes which can convert glucose to Phloroglucinol have been established. However, due to approximate 80% of the glucose being transformed into undesirable by-products and biomass, this biosynthesis process only shows a low yield with the highest value of about 0.20 g/g. The industrial applications are usually hindered by the low current productivity and yield and also by the high costs. Generally, several different aspects limit the development of Phloroglucinol biosynthesis. The yield of Phloroglucinol is one of the most important parameters for its bioconversion especially from economic and ecological points of view. The in vitro biosynthesis of bio-based chemicals, is a flexible alternative with potentially high-yield to in vivo biosynthetic technology. Results By comparing the activity of acetyl-CoA synthetase (ACS) from Escherichia coli and Acetobacter pasteurianus, the highly active ACS2 was identified in A. pasteurianus. Acetyl-CoA carboxylase (ACC) from Acinetobacter calcoaceticus and Phloroglucinol synthase (PhlD) from Pseudomonas fluorescens pf-5 were expressed and purified. Acetate was successfully transformed into Phloroglucinol by the combined activity of above-mentioned enzymes and required cofactor. After optimization of the in vitro reaction system, Phloroglucinol was then produced with a yield of nearly 0.64 g Phloroglucinol/g acetic acid, which was equal to 91.43% of the theoretically possible maximum. Conclusions In this work, a novel in vitro synthetic system for a highly efficient production of Phloroglucinol from acetate was demonstrated. The system’s performance suggests that in vitro synthesis of Phloroglucinol has some advantages and is potential to become a feasible industrial alternative. Based on the results presented herewith, it is believed that in vitro biosystem will provide a feasible option for production of important industrial chemicals from acetate, which could work as a versatile biosynthetic platform
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Improved Phloroglucinol production by metabolically engineered Escherichia coli
Applied microbiology and biotechnology, 2011Co-Authors: Yujin Cao, Xinglin Jiang, Rubing Zhang, Mo XianAbstract:Phloroglucinol is a valuable chemical which has been successfully produced by metabolically engineered Escherichia coli. However, the low productivity remains a bottleneck for large-scale application and cost-effective production. In the present work, we cloned the key biosynthetic gene, phlD (a type III polyketide synthase), into a bacterial expression vector to produce Phloroglucinol in E. coli and developed different strategies to re-engineer the recombinant strain for robust synthesis of Phloroglucinol. Overexpression of E. coli marA (multiple antibiotic resistance) gene enhanced Phloroglucinol resistance and elevated Phloroglucinol production to 0.27 g/g dry cell weight. Augmentation of the intracellular malonyl coenzyme A (malonyl-CoA) level through coordinated expression of four acetyl-CoA carboxylase (ACCase) subunits increased Phloroglucinol production to around 0.27 g/g dry cell weight. Furthermore, the coexpression of ACCase and marA caused another marked improvement in Phloroglucinol production 0.45 g/g dry cell weight, that is, 3.3-fold to the original strain. Under fed-batch conditions, this finally engineered strain accumulated Phloroglucinol up to 3.8 g/L in the culture 12 h after induction, corresponding to a volumetric productivity of 0.32 g/L/h. This result was the highest Phloroglucinol production to date and showed promising to make the bioprocess economically feasible.
Ji-sook Han - One of the best experts on this subject based on the ideXlab platform.
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A phlorotannin constituent of Ecklonia cava alleviates postprandial hyperglycemia in diabetic mice.
Pharmaceutical Biology, 2017Co-Authors: Hyun Ah Lee, Ji-hyeok Lee, Ji-sook HanAbstract:AbstractContext: 2,7″-Phloroglucinol-6,6′-bieckol is a type of phlorotannin isolated from brown algae, Ecklonia cava Kjellman (Phaeophyceae; Laminareaceae). 2,7″-Phloroglucinol-6,6′-bieckol mediates antioxidant activities. However, there has been no research on improving postprandial hyperglycaemia using 2,7″-Phloroglucinol-6,6′-bieckol.Objective: This study investigated the inhibitory effects of 2,7″-Phloroglucinol-6,6′-bieckol on activities of α-glucosidase and α-amylase as well as its alleviating effect on postprandial hyperglycaemia in streptozotocin-induced diabetic mice.Materials and methods: α-Glucosidase and α-amylase inhibitory assays were carried out. The effect of 2,7″-Phloroglucinol-6,6′-bieckol on hyperglycaemia after a meal was measured by postprandial blood glucose in streptozotocin-induced diabetic and normal mice. The mice were treated orally with soluble starch (2 g/kg BW) alone (control) or with 2,7″-Phloroglucinol-6,6′-bieckol (10 mg/kg bw) or acarbose (10 mg/kg BW) dissolved in 0.2 mL...
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A phlorotannin constituent of Ecklonia cava alleviates postprandial hyperglycemia in diabetic mice
Taylor & Francis Group, 2017Co-Authors: Hyun Ah Lee, Ji-hyeok Lee, Ji-sook HanAbstract:Context: 2,7″-Phloroglucinol-6,6′-bieckol is a type of phlorotannin isolated from brown algae, Ecklonia cava Kjellman (Phaeophyceae; Laminareaceae). 2,7″-Phloroglucinol-6,6′-bieckol mediates antioxidant activities. However, there has been no research on improving postprandial hyperglycaemia using 2,7″-Phloroglucinol-6,6′-bieckol. Objective: This study investigated the inhibitory effects of 2,7″-Phloroglucinol-6,6′-bieckol on activities of α-glucosidase and α-amylase as well as its alleviating effect on postprandial hyperglycaemia in streptozotocin-induced diabetic mice. Materials and methods: α-Glucosidase and α-amylase inhibitory assays were carried out. The effect of 2,7″-Phloroglucinol-6,6′-bieckol on hyperglycaemia after a meal was measured by postprandial blood glucose in streptozotocin-induced diabetic and normal mice. The mice were treated orally with soluble starch (2 g/kg BW) alone (control) or with 2,7″-Phloroglucinol-6,6′-bieckol (10 mg/kg bw) or acarbose (10 mg/kg BW) dissolved in 0.2 mL water. Blood samples were taken from tail veins at 0, 30, 60, and 120 min and blood glucose was measured by a glucometer. Results: 2,7″-Phloroglucinol-6,6′-bieckol showed higher inhibitory activities than acarbose, a positive control against α-glucosidase and α-amylase. The IC50 values of 2,7″-Phloroglucinol-6,6′-bieckol against α-glucosidase and α-amylase were 23.35 and 6.94 μM, respectively, which was found more effective than observed with acarbose (α-glucosidase IC50 of 130.04 μM; α-amylase IC50 of 165.12 μM). In normal mice, 2,7″-Phloroglucinol-6,6′-bieckol significantly suppressed the postprandial hyperglycaemia caused by starch. The 2,7″-Phloroglucinol-6,6′-bieckol administration group (2349.3 mmol·min/L) had a lower area under the curve (AUC) glucose response than the control group (2690.83 mmol·min/L) in diabetic mice. Discussion and conclusion: 2,7″-Phloroglucinol-6,6′-bieckol might be used as an inhibitor of α-glucosidase and α-amylase as well as to delay absorption of dietary carbohydrates
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Phloroglucinol protects ins 1 pancreatic β cells against glucotoxicity induced apoptosis
Phytotherapy Research, 2015Co-Authors: Mi Hwa Park, Ji-sook HanAbstract:Decreasing numbers, and impaired function, of pancreatic β-cells are key factors in the development of type 2 diabetes. This study was designed to investigate whether Phloroglucinol protected pancreatic β-cells against glucotoxicity-induced apoptosis using a rat insulinoma cell line (INS-1). High glucose treatment (30 mM) induced INS-1 cell death; however, the level of glucose-induced apoptosis was significantly reduced in cells treated with 100-μM Phloroglucinol. Treatment with 10–100-μM Phloroglucinol increased cell viability and decreased intracellular levels of reactive oxygen species, nitric oxide, and lipid peroxidation dose-dependently in INS-1 cells pretreated with high glucose. Furthermore, Phloroglucinol treatment markedly reduced the protein expression of Bax, cytochrome c, and caspase 9, while increasing anti-apoptotic Bcl-2 protein expression. Cell death type was examined using annexin V/propidium iodide staining, revealing that Phloroglucinol markedly reduced high glucose-induced apoptosis. These results demonstrated that Phloroglucinol could be useful as a potential therapeutic agent for the protection of pancreatic β-cells against glucose-induced apoptosis. Copyright © 2015 John Wiley & Sons, Ltd.
