Salidroside(8-O-β-D-glucoside of tyrosol),a plant-derived natural product,is used for treatment of hypoxia,fatigue and aging diseases.The availability of salidroside is restricted since it is extracted from3-5 years ...Salidroside(8-O-β-D-glucoside of tyrosol),a plant-derived natural product,is used for treatment of hypoxia,fatigue and aging diseases.The availability of salidroside is restricted since it is extracted from3-5 years old Rhodiola roots,which grow very slowly in the cold region of northern hemisphere of Earth.Our laboratory has constructed an engineered Escherichia coli and established a fermentation process to produce salidroside from glucose.In this article,nine macroporous resins from polarity to non-polarity,including NKA-9,S-8,AB-8,SP825,D101,LSA-8,LX-12,LX-18 and LX-68 resins,were tested to separate salidroside from fermentation broth.After static and dynamic experiments,the weakly polar SP825 resin had a better separation efficiency among nine resins.The adsorption kinetic and isotherm of salidroside on the SP825 resin were determined,and the pseudo-second-order kinetic model and Langmuir model could be fitted well.The effects of the pH on adsorption and ethanol concentration on desorption were investigated,and an optimal separation process was established.The adsorption for salidroside in the SP825 resin column was conducted with loading 150 ml at pH 7,and desorpted by washing 50 ml of80%ethanol solution.Under the best process conditions,the purity and yield of salidroside in the final product were 91.6%and 74.0%,respectively.The results showed that the macroporous SP825 resin would be feasible and effective to prepare salidroside and has promising application in the downstream process of microbial fermentation.展开更多
Resveratrol,a valuable plant-derived polyphenolic compound with various bioactivities,has been widely used in nutraceutical industries.Microbial production of resveratrol suffers from metabolic burden and low malonyl-...Resveratrol,a valuable plant-derived polyphenolic compound with various bioactivities,has been widely used in nutraceutical industries.Microbial production of resveratrol suffers from metabolic burden and low malonyl-CoA availability,which is a big challenge for synthetic biology.Herein,we took advantage of coculture engineering and divided the biosynthetic pathway of resveratrol into the upstream and downstream strains.By enhancing the supply of malonyl-CoA via CRISPRi system and fine-tuning the expression intensity of the synthetic pathway genes,we significantly improved the resveratrol productivity of the downstream strain.Furthermore,we developed a resveratrol addiction circuit that coupled the growth of the upstream strain and the resveratrol production of the downstream strain.The bidirectional interaction stabilized the coculture system and increased the production of resveratrol by 74%.Moreover,co-utilization of glucose and arabinose by the coculture system maintained the growth advantage of the downstream strain for production of resveratrol throughout the fermentation process.Under optimized conditions,the engineered E.coli coculture system produced 204.80 mg/L of resveratrol,12.8-fold improvement over monoculture system.This study demonstrates the promising potential of coculture engineering for efficient production of natural products from biomass.展开更多
Betanin is a member of natural pigment betacyanins family and has extensive application in the food industry as an important natural red food colorant.Its relatively inefficient production in nature however hampers ac...Betanin is a member of natural pigment betacyanins family and has extensive application in the food industry as an important natural red food colorant.Its relatively inefficient production in nature however hampers access to this phytochemicals through traditional crop-based manufacturing.Microbial bioproduction therefore represents an attractive alternative.Here,we present the construction of a Saccharomyces cerevisiae strain for betanin production.Through minimizing metabolic crosstalk,screening and modifying biosynthetic enzymes,enhancing pathway flux and optimizing fermentation conditions,a final titer of betanin of 28.7 mg/L was achieved from glucose at 25℃ in baffled shake-flask,which is the highest reported titer produced by yeast to our knowledge.This work provides a promising step towards developing synthetic yeast cell factories for de novo biosynthesis of value-added betanin and other betacyanins.展开更多
Benzyl and phenylpropanoid acids are widely used in organic synthesis of fine chemicals,such as pharmaceuticals and condiments.However,biocatalysis of these acids has received less attention than chemical synthesis.On...Benzyl and phenylpropanoid acids are widely used in organic synthesis of fine chemicals,such as pharmaceuticals and condiments.However,biocatalysis of these acids has received less attention than chemical synthesis.One of the main challenges for biological production is the limited availability of alcohol dehydrogenases and aldehyde dehydrogenases.Environmental microorganisms are potential sources of these enzymes.In this study,129 alcohol dehydrogenases and 42 aldehyde dehydrogenases from Corynebacterium glutamicum,Pseudomonas aeruginosa,and Bacillus subtilis were identified and explored with various benzyl and phenylpropanoid alcohol and aldehyde substrates,among which four alcohol dehydrogenases and four aldehyde dehydrogenases with broad substrate specificity and high catalytic activity were obtained.Moreover,a cascade whole-cell catalytic system including ADH-90,ALDH-40,and the NAD(P)H oxidase LreNox was established,which showed high efficiency in converting cinnamyl alcohol and p-methylbenzyl alcohol into the respective carboxylic acids.Remarkably,this biocatalytic system can be easily scaled up to gram-level production,facilitating preparation purposes.展开更多
基金supported by The Key-Area Research and Development Program of Guangdong Province(2020B0303070002),China。
文摘Salidroside(8-O-β-D-glucoside of tyrosol),a plant-derived natural product,is used for treatment of hypoxia,fatigue and aging diseases.The availability of salidroside is restricted since it is extracted from3-5 years old Rhodiola roots,which grow very slowly in the cold region of northern hemisphere of Earth.Our laboratory has constructed an engineered Escherichia coli and established a fermentation process to produce salidroside from glucose.In this article,nine macroporous resins from polarity to non-polarity,including NKA-9,S-8,AB-8,SP825,D101,LSA-8,LX-12,LX-18 and LX-68 resins,were tested to separate salidroside from fermentation broth.After static and dynamic experiments,the weakly polar SP825 resin had a better separation efficiency among nine resins.The adsorption kinetic and isotherm of salidroside on the SP825 resin were determined,and the pseudo-second-order kinetic model and Langmuir model could be fitted well.The effects of the pH on adsorption and ethanol concentration on desorption were investigated,and an optimal separation process was established.The adsorption for salidroside in the SP825 resin column was conducted with loading 150 ml at pH 7,and desorpted by washing 50 ml of80%ethanol solution.Under the best process conditions,the purity and yield of salidroside in the final product were 91.6%and 74.0%,respectively.The results showed that the macroporous SP825 resin would be feasible and effective to prepare salidroside and has promising application in the downstream process of microbial fermentation.
基金This work was supported by the Key-Area Research and Development Program of Guangdong Province(2020B0303070002)the National Natural Science Foundation of China(31870077).
文摘Resveratrol,a valuable plant-derived polyphenolic compound with various bioactivities,has been widely used in nutraceutical industries.Microbial production of resveratrol suffers from metabolic burden and low malonyl-CoA availability,which is a big challenge for synthetic biology.Herein,we took advantage of coculture engineering and divided the biosynthetic pathway of resveratrol into the upstream and downstream strains.By enhancing the supply of malonyl-CoA via CRISPRi system and fine-tuning the expression intensity of the synthetic pathway genes,we significantly improved the resveratrol productivity of the downstream strain.Furthermore,we developed a resveratrol addiction circuit that coupled the growth of the upstream strain and the resveratrol production of the downstream strain.The bidirectional interaction stabilized the coculture system and increased the production of resveratrol by 74%.Moreover,co-utilization of glucose and arabinose by the coculture system maintained the growth advantage of the downstream strain for production of resveratrol throughout the fermentation process.Under optimized conditions,the engineered E.coli coculture system produced 204.80 mg/L of resveratrol,12.8-fold improvement over monoculture system.This study demonstrates the promising potential of coculture engineering for efficient production of natural products from biomass.
基金supported by the Research and Development Program in Key Areas of Guangdong Province,China (2020B0303070002).
文摘Betanin is a member of natural pigment betacyanins family and has extensive application in the food industry as an important natural red food colorant.Its relatively inefficient production in nature however hampers access to this phytochemicals through traditional crop-based manufacturing.Microbial bioproduction therefore represents an attractive alternative.Here,we present the construction of a Saccharomyces cerevisiae strain for betanin production.Through minimizing metabolic crosstalk,screening and modifying biosynthetic enzymes,enhancing pathway flux and optimizing fermentation conditions,a final titer of betanin of 28.7 mg/L was achieved from glucose at 25℃ in baffled shake-flask,which is the highest reported titer produced by yeast to our knowledge.This work provides a promising step towards developing synthetic yeast cell factories for de novo biosynthesis of value-added betanin and other betacyanins.
基金This work was supported by the National Key Research and Development Program of China(2021YFA0911500)the National Natural Science Foundation of China(32071266,32170088,and 32370032)+1 种基金the Shandong Provincial Natural Science Foundation(ZR2020ZD23)the State Key Laboratory of Microbial Technology Open Projects Fund(M2022-01).
文摘Benzyl and phenylpropanoid acids are widely used in organic synthesis of fine chemicals,such as pharmaceuticals and condiments.However,biocatalysis of these acids has received less attention than chemical synthesis.One of the main challenges for biological production is the limited availability of alcohol dehydrogenases and aldehyde dehydrogenases.Environmental microorganisms are potential sources of these enzymes.In this study,129 alcohol dehydrogenases and 42 aldehyde dehydrogenases from Corynebacterium glutamicum,Pseudomonas aeruginosa,and Bacillus subtilis were identified and explored with various benzyl and phenylpropanoid alcohol and aldehyde substrates,among which four alcohol dehydrogenases and four aldehyde dehydrogenases with broad substrate specificity and high catalytic activity were obtained.Moreover,a cascade whole-cell catalytic system including ADH-90,ALDH-40,and the NAD(P)H oxidase LreNox was established,which showed high efficiency in converting cinnamyl alcohol and p-methylbenzyl alcohol into the respective carboxylic acids.Remarkably,this biocatalytic system can be easily scaled up to gram-level production,facilitating preparation purposes.
