The Experts below are selected from a list of 246 Experts worldwide ranked by ideXlab platform
Jose Manuel Dominguez - One of the best experts on this subject based on the ideXlab platform.
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bioproduction of 4 vinylphenol from corn cob alkaline hydrolyzate in two phase extractive fermentation using free or immobilized recombinant e coli expressing pad gene
Enzyme and Microbial Technology, 2014Co-Authors: Jose Manuel Salgado, Raquel Rodriguezsolana, Jose Antonio Curiel, Blanca De Las Rivas, Rosario Munoz, Jose Manuel DominguezAbstract:In situ extractive fermentation was used to produce 4-vinyl derivatives from hydroxycinnamic acids extracted from corn cobs by recombinant Escherichia coli cells expressing Lactobacillus plantarum phenolic acid descarboxylase (PAD) gene. This microorganism mainly produced 4-vinylphenol (4VP) from p-coumaric acid (p-CA). In the first study , we observed that the concentrations of 4VP are higher than 1g/L which had a negative impact on decarboxylation of p-CA to 4VP by recombinant E. coli cells. Because of this, and in order to improve the downstream process, a two-phase aqueous-organic solvent system was developed. The results of the extractive fermentation indicated that it was possible to use hydrolyzates as aqueous phase to bioproduce 4VP, and recover simultaneously the product in the organic phase containing hexane. The detoxification of pre-treated corn cob alkaline hydrolyzate improved 4VP production up to 1003.5mg/L after 24h fermentation (QP=41.813mg/Lh). Additionally, preliminary experiments using cells immobilized in calcium alginate showed to be a good system for the biotransform of p-CA to 4VP in extractive fermentation, although the process hindered partially the recovery of 4VP in the organic phase.
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production of vinyl derivatives from alkaline hydrolysates of corn cobs by recombinant escherichia coli containing the phenolic acid decarboxylase from lactobacillus plantarum cect 748t
Bioresource Technology, 2012Co-Authors: Jose Manuel Salgado, Raquel Rodriguezsolana, Jose Antonio Curiel, Blanca De Las Rivas, Rosario Munoz, Jose Manuel DominguezAbstract:The enzyme PAD from Lactobacillus plantarum CECT 748T decarboxylates some cinnamic acids namely p-coumaric acid (p-CA), caffeic acid (CA), and ferulic acid (FA) into their corresponding 4-vinyl derivatives (4-VD): 4-vinyl phenol (4-VP), 4-vinyl catechol (4-VC), and 4-vinyl guaiacol (4-VG), respectively, which are valuable food additives mainly employed as flavouring agents. The gene encoding this enzyme was cloned and overexpressed in Escherichia coli. Recombinant E. coli cells overproducing L. plantarum PAD showed a preference to degrade mainly p-CA and CA. Sterilized liquors obtained after alkaline hydrolysis of corn cob or alkaline hydrolysis of the solid residue coming from acid hydrolysis of corn cob were employed as growth media in fermentations performed in shaker or bioreactor. The fermentative process allowed converting 2222.8 mg/L p-CA into 993.9 mg/L 4-VP. The process described here allowed the production with a high-yield of a valuable food additive from a by-product of the food industry.
Guenther K. Bonn - One of the best experts on this subject based on the ideXlab platform.
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poly n vinylimidazole ethylene glycol dimethacrylate for the purification and isolation of phenolic acids
Analytica Chimica Acta, 2015Co-Authors: Dieter Schemeth, Jeanchristophe Noel, Thomas Jakschitz, Christian W Huck, Matthias Rainer, Richard Tessadri, Guenther K. BonnAbstract:Abstract In this study we report the novel polymeric resin poly(N-vinyl imidazole/ethylene glycol dimethacrylate) for the purification and isolation of phenolic acids. The monomer to crosslinker ratio and the porogen composition were optimized for isolating phenolic acids diluted in acetonitrile at normal phase chromatography conditions, first. Acetonitrile serves as polar, aprotic solvent, dissolving phenolic acids but not interrupting interactions with the stationary phase due to the approved Hansen solubility parameters. The optimized resin demonstrated high loading capacities and adsorption abilities particularly for phenolic acids in both, acetonitrile and aqueous solutions. The adsorption behavior of aqueous standards can be attributed to ion exchange effects due to electrostatic interactions between protonated imidazole residues and deprotonated phenolic acids. Furthermore, adsorption experiments and subsequent curve fittings provide information of maximum loading capacities of single standards according to the Langmuir adsorption model. Recovery studies of the optimized polymer in the normal-phase and ion-exchange mode illustrate the powerful isolation properties for phenolic acids and are comparable or even better than typical, commercially available solid phase extraction materials. In order to prove the applicability, a highly complex extract of rosemary leaves was purified by poly(N-vinyl imidazole/ethylene glycol dimethacrylate) and the isolated compounds were identified using UHPLC–qTOF-MS.
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Poly(N-vinylimidazole/ethylene glycol dimethacrylate) for the purification and isolation of phenolic acids.
Analytica Chimica Acta, 2015Co-Authors: Dieter Schemeth, Jeanchristophe Noel, Thomas Jakschitz, Christian W Huck, Matthias Rainer, Richard Tessadri, Guenther K. BonnAbstract:Abstract In this study we report the novel polymeric resin poly(N-vinyl imidazole/ethylene glycol dimethacrylate) for the purification and isolation of phenolic acids. The monomer to crosslinker ratio and the porogen composition were optimized for isolating phenolic acids diluted in acetonitrile at normal phase chromatography conditions, first. Acetonitrile serves as polar, aprotic solvent, dissolving phenolic acids but not interrupting interactions with the stationary phase due to the approved Hansen solubility parameters. The optimized resin demonstrated high loading capacities and adsorption abilities particularly for phenolic acids in both, acetonitrile and aqueous solutions. The adsorption behavior of aqueous standards can be attributed to ion exchange effects due to electrostatic interactions between protonated imidazole residues and deprotonated phenolic acids. Furthermore, adsorption experiments and subsequent curve fittings provide information of maximum loading capacities of single standards according to the Langmuir adsorption model. Recovery studies of the optimized polymer in the normal-phase and ion-exchange mode illustrate the powerful isolation properties for phenolic acids and are comparable or even better than typical, commercially available solid phase extraction materials. In order to prove the applicability, a highly complex extract of rosemary leaves was purified by poly(N-vinyl imidazole/ethylene glycol dimethacrylate) and the isolated compounds were identified using UHPLC–qTOF-MS.
Dieter Schemeth - One of the best experts on this subject based on the ideXlab platform.
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poly n vinylimidazole ethylene glycol dimethacrylate for the purification and isolation of phenolic acids
Analytica Chimica Acta, 2015Co-Authors: Dieter Schemeth, Jeanchristophe Noel, Thomas Jakschitz, Christian W Huck, Matthias Rainer, Richard Tessadri, Guenther K. BonnAbstract:Abstract In this study we report the novel polymeric resin poly(N-vinyl imidazole/ethylene glycol dimethacrylate) for the purification and isolation of phenolic acids. The monomer to crosslinker ratio and the porogen composition were optimized for isolating phenolic acids diluted in acetonitrile at normal phase chromatography conditions, first. Acetonitrile serves as polar, aprotic solvent, dissolving phenolic acids but not interrupting interactions with the stationary phase due to the approved Hansen solubility parameters. The optimized resin demonstrated high loading capacities and adsorption abilities particularly for phenolic acids in both, acetonitrile and aqueous solutions. The adsorption behavior of aqueous standards can be attributed to ion exchange effects due to electrostatic interactions between protonated imidazole residues and deprotonated phenolic acids. Furthermore, adsorption experiments and subsequent curve fittings provide information of maximum loading capacities of single standards according to the Langmuir adsorption model. Recovery studies of the optimized polymer in the normal-phase and ion-exchange mode illustrate the powerful isolation properties for phenolic acids and are comparable or even better than typical, commercially available solid phase extraction materials. In order to prove the applicability, a highly complex extract of rosemary leaves was purified by poly(N-vinyl imidazole/ethylene glycol dimethacrylate) and the isolated compounds were identified using UHPLC–qTOF-MS.
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Poly(N-vinylimidazole/ethylene glycol dimethacrylate) for the purification and isolation of phenolic acids.
Analytica Chimica Acta, 2015Co-Authors: Dieter Schemeth, Jeanchristophe Noel, Thomas Jakschitz, Christian W Huck, Matthias Rainer, Richard Tessadri, Guenther K. BonnAbstract:Abstract In this study we report the novel polymeric resin poly(N-vinyl imidazole/ethylene glycol dimethacrylate) for the purification and isolation of phenolic acids. The monomer to crosslinker ratio and the porogen composition were optimized for isolating phenolic acids diluted in acetonitrile at normal phase chromatography conditions, first. Acetonitrile serves as polar, aprotic solvent, dissolving phenolic acids but not interrupting interactions with the stationary phase due to the approved Hansen solubility parameters. The optimized resin demonstrated high loading capacities and adsorption abilities particularly for phenolic acids in both, acetonitrile and aqueous solutions. The adsorption behavior of aqueous standards can be attributed to ion exchange effects due to electrostatic interactions between protonated imidazole residues and deprotonated phenolic acids. Furthermore, adsorption experiments and subsequent curve fittings provide information of maximum loading capacities of single standards according to the Langmuir adsorption model. Recovery studies of the optimized polymer in the normal-phase and ion-exchange mode illustrate the powerful isolation properties for phenolic acids and are comparable or even better than typical, commercially available solid phase extraction materials. In order to prove the applicability, a highly complex extract of rosemary leaves was purified by poly(N-vinyl imidazole/ethylene glycol dimethacrylate) and the isolated compounds were identified using UHPLC–qTOF-MS.
Raquel Rodriguezsolana - One of the best experts on this subject based on the ideXlab platform.
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bioproduction of 4 vinylphenol from corn cob alkaline hydrolyzate in two phase extractive fermentation using free or immobilized recombinant e coli expressing pad gene
Enzyme and Microbial Technology, 2014Co-Authors: Jose Manuel Salgado, Raquel Rodriguezsolana, Jose Antonio Curiel, Blanca De Las Rivas, Rosario Munoz, Jose Manuel DominguezAbstract:In situ extractive fermentation was used to produce 4-vinyl derivatives from hydroxycinnamic acids extracted from corn cobs by recombinant Escherichia coli cells expressing Lactobacillus plantarum phenolic acid descarboxylase (PAD) gene. This microorganism mainly produced 4-vinylphenol (4VP) from p-coumaric acid (p-CA). In the first study , we observed that the concentrations of 4VP are higher than 1g/L which had a negative impact on decarboxylation of p-CA to 4VP by recombinant E. coli cells. Because of this, and in order to improve the downstream process, a two-phase aqueous-organic solvent system was developed. The results of the extractive fermentation indicated that it was possible to use hydrolyzates as aqueous phase to bioproduce 4VP, and recover simultaneously the product in the organic phase containing hexane. The detoxification of pre-treated corn cob alkaline hydrolyzate improved 4VP production up to 1003.5mg/L after 24h fermentation (QP=41.813mg/Lh). Additionally, preliminary experiments using cells immobilized in calcium alginate showed to be a good system for the biotransform of p-CA to 4VP in extractive fermentation, although the process hindered partially the recovery of 4VP in the organic phase.
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production of vinyl derivatives from alkaline hydrolysates of corn cobs by recombinant escherichia coli containing the phenolic acid decarboxylase from lactobacillus plantarum cect 748t
Bioresource Technology, 2012Co-Authors: Jose Manuel Salgado, Raquel Rodriguezsolana, Jose Antonio Curiel, Blanca De Las Rivas, Rosario Munoz, Jose Manuel DominguezAbstract:The enzyme PAD from Lactobacillus plantarum CECT 748T decarboxylates some cinnamic acids namely p-coumaric acid (p-CA), caffeic acid (CA), and ferulic acid (FA) into their corresponding 4-vinyl derivatives (4-VD): 4-vinyl phenol (4-VP), 4-vinyl catechol (4-VC), and 4-vinyl guaiacol (4-VG), respectively, which are valuable food additives mainly employed as flavouring agents. The gene encoding this enzyme was cloned and overexpressed in Escherichia coli. Recombinant E. coli cells overproducing L. plantarum PAD showed a preference to degrade mainly p-CA and CA. Sterilized liquors obtained after alkaline hydrolysis of corn cob or alkaline hydrolysis of the solid residue coming from acid hydrolysis of corn cob were employed as growth media in fermentations performed in shaker or bioreactor. The fermentative process allowed converting 2222.8 mg/L p-CA into 993.9 mg/L 4-VP. The process described here allowed the production with a high-yield of a valuable food additive from a by-product of the food industry.
Shaojun Ding - One of the best experts on this subject based on the ideXlab platform.
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High cell‐density cultivation of phenolic acid decarboxylase‐expressing Escherichia coli and 4‐vinylguaiacol bioproduction from ferulic acid by whole‐cell catalysis
Journal of Chemical Technology & Biotechnology, 2018Co-Authors: Yuheng Chen, Liangkun Long, Shaojun DingAbstract:BACKGROUND: 4‐vinyl guaiacol (4‐VG) is a high value‐added product widely used in the cosmetic, pharmaceutical, and chemical industries. The practical bioproduction of 4‐VG using phenolic acid decarboxylases has been limited by its relatively high biocatalyst cost and low yield and product concentration. RESULTS: In the present study, high‐cell density cultivation was employed to improve the activity and production of phenolic acid decarboxylase from Bacillus licheniformis (BLPAD) in recombinant Escherichia coli. The factors influencing enzyme production in E. coli such as the induction point and temperature for induction and feeding strategies were optimized. The highest BLPAD activity (531 U mL‐¹) and productivity (20.4 U mL‐¹ h‐¹), respectively, were achieved in a 5 L bioreactor using a glucose exponential feeding strategy with isopropyl β‐D‐thiogalactoside (IPTG) as inducer. Furthermore, a high BLPAD production level (512 U mL‐¹) was achieved using lactose as an inducer and continuous lactose feeding. Using a biphasic emulsion system with equal volumes (1 L) of cyclohexane as a organic solvent and a substrate fed‐batch strategy, the concentration and conversion yield of 4‐VG reached 129.9 g L‐¹ (85.6%) in a 5 L bioreactor by whole‐cell biocatalysis, which is the highest reported to date. CONCLUSION: This study describes a strategy for large‐scale 4‐VG bioproduction using the biocatalytic method. © 2018 Society of Chemical Industry
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An organic solvent-tolerant phenolic acid decarboxylase from Bacillus licheniformis for the efficient bioconversion of hydroxycinnamic acids to vinyl phenol derivatives
Applied microbiology and biotechnology, 2014Co-Authors: Shaojun DingAbstract:A new phenolic acid decarboxylase gene (blpad) from Bacillus licheniformis was cloned and overexpressed in Escherichia coli. The full-length blpad encodes a 166-amino acid polypeptide with a predicted molecular mass and pI of 19,521 Da and 5.02, respectively. The recombinant BLPAD displayed maximum activity at 37 °C and pH 6.0. This enzyme possesses a broad substrate specificity and is able to decarboxylate p-coumaric, ferulic, caffeic, and sinapic acids at the relative ratios of specific activities 100:74.59:34.41:0.29. Kinetic constant Km values toward p-coumaric, ferulic, caffeic, and sinapic acids were 1.64, 1.55, 1.93, and 2.45 mM, and Vmax values were 268.43, 216.80, 119.07, and 0.78 U mg−1, respectively. In comparison with other phenolic acid decarboxylases, BLPAD exhibited remarkable organic solvent tolerance and good thermal stability. BLPAD showed excellent catalytic performance in biphasic organic/aqueous systems and efficiently converted p-coumaric and ferulic acids into 4-vinylphenol and 4-vinylguaiacol. At 500 mM of p-coumaric and ferulic acids, the recombinant BLPAD produced a total 60.63 g l−1 4-vinylphenol and 58.30 g l−1 4-vinylguaiacol with the conversion yields 97.02 and 70.96 %, respectively. The low yield and product concentration are the crucial drawbacks to the practical bioproduction of vinyl phenol derivatives using phenolic acid decarboxylases. These unusual properties make BLPAD a desirable biocatalyst for commercial use in the bioconversion of hydroxycinnamic acids to vinyl phenol derivatives via enzymatic decarboxylation in a biphasic organic/aqueous reaction system.