Pub Date : 2022-01-10DOI: 10.3389/fctls.2021.816538
S. N. Chanquia, Alessia Valotta, H. Gruber-Woelfler, S. Kara
In the last years, there were two fields that experienced an astonishing growth within the biocatalysis community: photobiocatalysis and applications of flow technology to catalytic processes. Therefore, it is not a surprise that the combination of these two research areas also gave place to several recent interesting articles. However, to the best of our knowledge, no review article covering these advances was published so far. Within this review, we present recent and very recent developments in the field of photobiocatalysis in continuous flow, we discuss several different practical applications and features of state-of-the art photobioreactors and lastly, we present some future perspectives in the field.
{"title":"Photobiocatalysis in Continuous Flow","authors":"S. N. Chanquia, Alessia Valotta, H. Gruber-Woelfler, S. Kara","doi":"10.3389/fctls.2021.816538","DOIUrl":"https://doi.org/10.3389/fctls.2021.816538","url":null,"abstract":"In the last years, there were two fields that experienced an astonishing growth within the biocatalysis community: photobiocatalysis and applications of flow technology to catalytic processes. Therefore, it is not a surprise that the combination of these two research areas also gave place to several recent interesting articles. However, to the best of our knowledge, no review article covering these advances was published so far. Within this review, we present recent and very recent developments in the field of photobiocatalysis in continuous flow, we discuss several different practical applications and features of state-of-the art photobioreactors and lastly, we present some future perspectives in the field.","PeriodicalId":73071,"journal":{"name":"Frontiers in catalysis","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47234873","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.3389/fctls.2022.1089176
Armaan Patel, David W Mulder, Dieter Söll, Natalie Krahn
Hydrogen is a clean, renewable energy source, that when combined with oxygen, produces heat and electricity with only water vapor as a biproduct. Furthermore, it has the highest energy content by weight of all known fuels. As a result, various strategies have engineered methods to produce hydrogen efficiently and in quantities that are of interest to the economy. To approach the notion of producing hydrogen from a biological perspective, we take our attention to hydrogenases which are naturally produced in microbes. These organisms have the machinery to produce hydrogen, which when cleverly engineered, could be useful in cell factories resulting in large production of hydrogen. Not all hydrogenases are efficient at hydrogen production, and those that are, tend to be oxygen sensitive. Therefore, we provide a new perspective on introducing selenocysteine, a highly reactive proteinogenic amino acid, as a strategy towards engineering hydrogenases with enhanced hydrogen production, or increased oxygen tolerance.
{"title":"Harnessing selenocysteine to enhance microbial cell factories for hydrogen production.","authors":"Armaan Patel, David W Mulder, Dieter Söll, Natalie Krahn","doi":"10.3389/fctls.2022.1089176","DOIUrl":"https://doi.org/10.3389/fctls.2022.1089176","url":null,"abstract":"<p><p>Hydrogen is a clean, renewable energy source, that when combined with oxygen, produces heat and electricity with only water vapor as a biproduct. Furthermore, it has the highest energy content by weight of all known fuels. As a result, various strategies have engineered methods to produce hydrogen efficiently and in quantities that are of interest to the economy. To approach the notion of producing hydrogen from a biological perspective, we take our attention to hydrogenases which are naturally produced in microbes. These organisms have the machinery to produce hydrogen, which when cleverly engineered, could be useful in cell factories resulting in large production of hydrogen. Not all hydrogenases are efficient at hydrogen production, and those that are, tend to be oxygen sensitive. Therefore, we provide a new perspective on introducing selenocysteine, a highly reactive proteinogenic amino acid, as a strategy towards engineering hydrogenases with enhanced hydrogen production, or increased oxygen tolerance.</p>","PeriodicalId":73071,"journal":{"name":"Frontiers in catalysis","volume":"2 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9961374/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10860148","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-12-20DOI: 10.3389/fctls.2021.803416
S. De Rose, W. Finnigan, N. Harmer, J. Littlechild
Osmolytes protect microbial cells against temperature, osmolarity and other stresses. The osmolyte cyclic 2,3-diphosphoglycerate, originally isolated from the thermophilic archaeon Methanothermus fervidus, naturally protects cellular proteins under extreme conditions. The biosynthetic pathway for cyclic 2,3-diphosphoglycerate has been introduced into the thermophilic bacterium Thermus thermophilus. The two enzymes in this synthetic pathway, 2-phosphoglycerate kinase and cyclic diphosphoglycerate synthetase, were incorporated into a newly designed modular BioBricks vector. The expression of this two-enzyme cascade resulted in the whole cell production of cyclic 2,3 diphosphoglycerate. In vivo production of cyclic 2,3-diphosphoglycerate was confirmed by mass spectrometry to a concentration up to 650 µM. This study demonstrates the feasibility of using this well studied thermophilic bacterium as a host in a whole-cell factory approach to produce cyclic 2,3 diphosphoglycerate. This raises the potential for commercialisation of cDPG for cosmetic and healthcare applications. Our work demonstrates the application of Thermus thermophilus as an alternative host for other high value small organic molecules of industrial interest.
{"title":"Production of the Extremolyte Cyclic 2,3-Diphosphoglycerate Using Thermus thermophilus as a Whole-Cell Factory","authors":"S. De Rose, W. Finnigan, N. Harmer, J. Littlechild","doi":"10.3389/fctls.2021.803416","DOIUrl":"https://doi.org/10.3389/fctls.2021.803416","url":null,"abstract":"Osmolytes protect microbial cells against temperature, osmolarity and other stresses. The osmolyte cyclic 2,3-diphosphoglycerate, originally isolated from the thermophilic archaeon Methanothermus fervidus, naturally protects cellular proteins under extreme conditions. The biosynthetic pathway for cyclic 2,3-diphosphoglycerate has been introduced into the thermophilic bacterium Thermus thermophilus. The two enzymes in this synthetic pathway, 2-phosphoglycerate kinase and cyclic diphosphoglycerate synthetase, were incorporated into a newly designed modular BioBricks vector. The expression of this two-enzyme cascade resulted in the whole cell production of cyclic 2,3 diphosphoglycerate. In vivo production of cyclic 2,3-diphosphoglycerate was confirmed by mass spectrometry to a concentration up to 650 µM. This study demonstrates the feasibility of using this well studied thermophilic bacterium as a host in a whole-cell factory approach to produce cyclic 2,3 diphosphoglycerate. This raises the potential for commercialisation of cDPG for cosmetic and healthcare applications. Our work demonstrates the application of Thermus thermophilus as an alternative host for other high value small organic molecules of industrial interest.","PeriodicalId":73071,"journal":{"name":"Frontiers in catalysis","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43167244","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-11-26DOI: 10.3389/fctls.2021.790461
Valentina Marchini, Ana I. Benítez-Mateos, David Roura Padrosa, F. Paradisi
A novel fusion protein has been rationally designed, combining the hexameric glutamate dehydrogenase from Clostridium symbiosum with the dimeric formate dehydrogenase from Candida boidinii. The former enzyme consumes ammonia for the reductive amination of α-ketoglutarate using NADH, while the latter biocatalyst regenerates continuously the cofactor. This enzymes fusion opens new perspectives for the detection and the removal of ammonia. The bifunctional biocatalyst has been successfully created, expressed, and then characterized. The two fused protein domains retained identical properties and catalytic activity of the individual enzymes. Additionally, the immobilization on a methacrylate resin optimized the assembly providing a reusable and stable biocatalyst. This is an example of immobilization of a fusion protein, so that efficiency and sustainability of the process are enhanced. The immobilized biocatalyst could be recycled 10 times retaining still half of the initial activity. Such preparation outperforms the co-immobilized wild-type enzymes in the conversion of 300 mM of ammonia, which could be carried out also in continuous mode.
{"title":"Fusion of Glutamate Dehydrogenase and Formate Dehydrogenase Yields a Bifunctional Efficient Biocatalyst for the Continuous Removal of Ammonia","authors":"Valentina Marchini, Ana I. Benítez-Mateos, David Roura Padrosa, F. Paradisi","doi":"10.3389/fctls.2021.790461","DOIUrl":"https://doi.org/10.3389/fctls.2021.790461","url":null,"abstract":"A novel fusion protein has been rationally designed, combining the hexameric glutamate dehydrogenase from Clostridium symbiosum with the dimeric formate dehydrogenase from Candida boidinii. The former enzyme consumes ammonia for the reductive amination of α-ketoglutarate using NADH, while the latter biocatalyst regenerates continuously the cofactor. This enzymes fusion opens new perspectives for the detection and the removal of ammonia. The bifunctional biocatalyst has been successfully created, expressed, and then characterized. The two fused protein domains retained identical properties and catalytic activity of the individual enzymes. Additionally, the immobilization on a methacrylate resin optimized the assembly providing a reusable and stable biocatalyst. This is an example of immobilization of a fusion protein, so that efficiency and sustainability of the process are enhanced. The immobilized biocatalyst could be recycled 10 times retaining still half of the initial activity. Such preparation outperforms the co-immobilized wild-type enzymes in the conversion of 300 mM of ammonia, which could be carried out also in continuous mode.","PeriodicalId":73071,"journal":{"name":"Frontiers in catalysis","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48397601","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-11-26DOI: 10.3389/fctls.2021.781284
Laurine Ducrot, M. Bennett, Adam A Caparco, J. Champion, A. Bommarius, A. Zaparucha, G. Grogan, C. Vergne‐Vaxelaire
Small optically active molecules, and more particularly short-chain chiral amines, are key compounds in the chemical industry and precursors of various pharmaceuticals. Their chemo-biocatalytic production on a commercial scale is already established, mainly through lipase-catalyzed resolutions leading to ChiPros™ products among others. Nevertheless, their biocatalytic synthesis remains challenging for very short-chain C4 to C5 amines due to low enantiomeric excess. To complement the possibilities recently offered by transaminases, this work describes alternative biocatalytic access using amine dehydrogenases (AmDHs). Without any protein engineering, some of the already described wild-type AmDHs (CfusAmDH, MsmeAmDH, MicroAmDH, and MATOUAmDH2) were shown to be efficient for the synthesis of hydroxylated or unfunctionalized small 2-aminoalkanes. Conversions up to 97.1% were reached at 50 mM, and moderate to high enantioselectivities were obtained, especially for (S)-1-methoxypropan-2-amine (98.1%), (S)-3-aminobutan-1-ol (99.5%), (3S)-3-aminobutan-2-ol (99.4%), and the small (S)-butan-2-amine (93.6%) with MsmeAmDH. Semi-preparative scale-up experiments were successfully performed at 150 mM substrate concentrations for the synthesis of (S)-butan-2-amine and (S)-1-methoxypropan-2-amine, the latter known as “(S)-MOIPA”. Modeling studies provided some preliminary results explaining the basis for the challenging discrimination between similarly sized substituents in the active sites of these enzymes.
{"title":"Biocatalytic Reductive Amination by Native Amine Dehydrogenases to Access Short Chiral Alkyl Amines and Amino Alcohols","authors":"Laurine Ducrot, M. Bennett, Adam A Caparco, J. Champion, A. Bommarius, A. Zaparucha, G. Grogan, C. Vergne‐Vaxelaire","doi":"10.3389/fctls.2021.781284","DOIUrl":"https://doi.org/10.3389/fctls.2021.781284","url":null,"abstract":"Small optically active molecules, and more particularly short-chain chiral amines, are key compounds in the chemical industry and precursors of various pharmaceuticals. Their chemo-biocatalytic production on a commercial scale is already established, mainly through lipase-catalyzed resolutions leading to ChiPros™ products among others. Nevertheless, their biocatalytic synthesis remains challenging for very short-chain C4 to C5 amines due to low enantiomeric excess. To complement the possibilities recently offered by transaminases, this work describes alternative biocatalytic access using amine dehydrogenases (AmDHs). Without any protein engineering, some of the already described wild-type AmDHs (CfusAmDH, MsmeAmDH, MicroAmDH, and MATOUAmDH2) were shown to be efficient for the synthesis of hydroxylated or unfunctionalized small 2-aminoalkanes. Conversions up to 97.1% were reached at 50 mM, and moderate to high enantioselectivities were obtained, especially for (S)-1-methoxypropan-2-amine (98.1%), (S)-3-aminobutan-1-ol (99.5%), (3S)-3-aminobutan-2-ol (99.4%), and the small (S)-butan-2-amine (93.6%) with MsmeAmDH. Semi-preparative scale-up experiments were successfully performed at 150 mM substrate concentrations for the synthesis of (S)-butan-2-amine and (S)-1-methoxypropan-2-amine, the latter known as “(S)-MOIPA”. Modeling studies provided some preliminary results explaining the basis for the challenging discrimination between similarly sized substituents in the active sites of these enzymes.","PeriodicalId":73071,"journal":{"name":"Frontiers in catalysis","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45062732","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-11-25DOI: 10.3389/fctls.2021.785963
César Iglesias, Ariel Tijman, Gonzalo López, M. I. Lapaz, M. J. Pianzzola, Paola Panizza, Sonia Rodríguez Giordano
The development of biocatalytic tools for the synthesis of optically pure amines has been the focus of abundant research in recent years. Among other enzymes, imine reductases have attracted much attention associated with the possibility of attaining chiral secondary amines. Furthermore, the reductive aminase activity associated with some of these enzymes has facilitated the production of optically pure amines from a prochiral ketone, a transformation that opens doors to an incredible array of products. In this work, the genomes from native Streptomyces strains isolated in our lab have been explored on the search for novel imine reductases. Application of different structural criteria and sequence motif filters allowed the identification of two novel enzymes, Ss-IRED_S and Ss-IRED_R. While the former presented outstanding activity towards bulky cyclic imine substrates, the latter presented reductive aminase activity with the assayed ketones. A bioinformatic analysis based on modeling and docking studies was performed in order to explain the differences in enzyme activity, searching for additional criteria that could be used to analyze enzyme candidates in silico, providing additional tools for enzyme selection for a particular application. Our findings suggest that imine reductase activity could be predicted by this analysis, overall accounting for the number of docking positions that meet the catalytic requirements.
{"title":"Identification, Characterization, and In Silico Analysis of New Imine Reductases From Native Streptomyces Genomes","authors":"César Iglesias, Ariel Tijman, Gonzalo López, M. I. Lapaz, M. J. Pianzzola, Paola Panizza, Sonia Rodríguez Giordano","doi":"10.3389/fctls.2021.785963","DOIUrl":"https://doi.org/10.3389/fctls.2021.785963","url":null,"abstract":"The development of biocatalytic tools for the synthesis of optically pure amines has been the focus of abundant research in recent years. Among other enzymes, imine reductases have attracted much attention associated with the possibility of attaining chiral secondary amines. Furthermore, the reductive aminase activity associated with some of these enzymes has facilitated the production of optically pure amines from a prochiral ketone, a transformation that opens doors to an incredible array of products. In this work, the genomes from native Streptomyces strains isolated in our lab have been explored on the search for novel imine reductases. Application of different structural criteria and sequence motif filters allowed the identification of two novel enzymes, Ss-IRED_S and Ss-IRED_R. While the former presented outstanding activity towards bulky cyclic imine substrates, the latter presented reductive aminase activity with the assayed ketones. A bioinformatic analysis based on modeling and docking studies was performed in order to explain the differences in enzyme activity, searching for additional criteria that could be used to analyze enzyme candidates in silico, providing additional tools for enzyme selection for a particular application. Our findings suggest that imine reductase activity could be predicted by this analysis, overall accounting for the number of docking positions that meet the catalytic requirements.","PeriodicalId":73071,"journal":{"name":"Frontiers in catalysis","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43084703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-11-23DOI: 10.3389/fctls.2021.774512
E. Hong, Sun-Gu Lee, Hyungdon Yun, Byung-Gee Kim
Agmatine, involved in various modulatory actions in cellular mechanisms, is produced from arginine (Arg) by decarboxylation reaction using arginine decarboxylase (ADC, EC 4.1.1.19). The major obstacle of using wild-type Escherichia coli ADC (ADCes) in agmatine production is its sharp activity loss and instability at alkaline pH. Here, to overcome this problem, a new disulfide bond was rationally introduced in the decameric interface region of the enzyme. Among the mutants generated, W16C/D43C increased both thermostability and activity. The half-life (T1/2) of W16C/D43C at pH 8.0 and 60°C was 560 min, which was 280-fold longer than that of the wild-type, and the specific activity at pH 8.0 also increased 2.1-fold. Site-saturation mutagenesis was subsequently performed at the active site residues of ADCes using the disulfide-bond mutant (W16C/D43C) as a template. The best variant W16C/D43C/I258A displayed a 4.4-fold increase in the catalytic efficiency when compared with the wild-type. The final mutant (W16C/D43C/I258A) was successfully applied to in vitro synthesis of agmatine with an improved yield and productivity (>89.0% yield based on 100 mM of Arg within 5 h).
{"title":"Improving the Stability and Activity of Arginine Decarboxylase at Alkaline pH for the Production of Agmatine","authors":"E. Hong, Sun-Gu Lee, Hyungdon Yun, Byung-Gee Kim","doi":"10.3389/fctls.2021.774512","DOIUrl":"https://doi.org/10.3389/fctls.2021.774512","url":null,"abstract":"Agmatine, involved in various modulatory actions in cellular mechanisms, is produced from arginine (Arg) by decarboxylation reaction using arginine decarboxylase (ADC, EC 4.1.1.19). The major obstacle of using wild-type Escherichia coli ADC (ADCes) in agmatine production is its sharp activity loss and instability at alkaline pH. Here, to overcome this problem, a new disulfide bond was rationally introduced in the decameric interface region of the enzyme. Among the mutants generated, W16C/D43C increased both thermostability and activity. The half-life (T1/2) of W16C/D43C at pH 8.0 and 60°C was 560 min, which was 280-fold longer than that of the wild-type, and the specific activity at pH 8.0 also increased 2.1-fold. Site-saturation mutagenesis was subsequently performed at the active site residues of ADCes using the disulfide-bond mutant (W16C/D43C) as a template. The best variant W16C/D43C/I258A displayed a 4.4-fold increase in the catalytic efficiency when compared with the wild-type. The final mutant (W16C/D43C/I258A) was successfully applied to in vitro synthesis of agmatine with an improved yield and productivity (>89.0% yield based on 100 mM of Arg within 5 h).","PeriodicalId":73071,"journal":{"name":"Frontiers in catalysis","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43116295","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-10-20DOI: 10.3389/fctls.2021.754167
Aijing Zhang, Mingzheng Zhou, Siyuan Liu, M. Chai, Shengjuan Jiang
Single-atom catalysts (SACs) have emerged as a hot research topic in recently years, and have been intensively investigated for energy storage and conversion applications. Significant advances in the synthesis of SACs have been achieved through enormous efforts in this area, however, their application is hindered by the low active site loading and poor long-term stability. In contrast with other methods, atomization, in which the SACs are synthesized from transformation of the nanoparticles to atomic sites, is a very attractive and innovative top-down approach to achieve high-density supported active sites with outstanding stability. However, limited attention has been paid to this area, despite the significant advances achieved in the past two years. In this short review, we discuss in detail the latest advances in atomization approaches for the synthesis of SACs and highlight the associated advantages and opportunities.
{"title":"Synthesis of Single-Atom Catalysts Through Top-Down Atomization Approaches","authors":"Aijing Zhang, Mingzheng Zhou, Siyuan Liu, M. Chai, Shengjuan Jiang","doi":"10.3389/fctls.2021.754167","DOIUrl":"https://doi.org/10.3389/fctls.2021.754167","url":null,"abstract":"Single-atom catalysts (SACs) have emerged as a hot research topic in recently years, and have been intensively investigated for energy storage and conversion applications. Significant advances in the synthesis of SACs have been achieved through enormous efforts in this area, however, their application is hindered by the low active site loading and poor long-term stability. In contrast with other methods, atomization, in which the SACs are synthesized from transformation of the nanoparticles to atomic sites, is a very attractive and innovative top-down approach to achieve high-density supported active sites with outstanding stability. However, limited attention has been paid to this area, despite the significant advances achieved in the past two years. In this short review, we discuss in detail the latest advances in atomization approaches for the synthesis of SACs and highlight the associated advantages and opportunities.","PeriodicalId":73071,"journal":{"name":"Frontiers in catalysis","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47558370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-10-12DOI: 10.3389/fctls.2021.742024
A. Schweiger, K. Miyamoto, R. Kourist
Bacterial arylmalonate decarboxylase (AMDase) is an intriguing cofactor-independent enzyme with a broad substrate spectrum. Particularly, the highly stereoselective transformation of diverse arylmalonic acids into the corresponding chiral α-arylpropionates has contributed to the broad recognition of this biocatalyst. While, more than 30 years after its discovery, the native substrate and function of AMDase still remain undiscovered, contributions from multiple fields have ever since brought forth a powerful collection of AMDase variants to access a wide variety of optically pure α-substituted propionates. This review aims at providing a comprehensive overview of the development of AMDase from an enzyme with unknown function up to a powerful tailored biocatalyst for the synthesis of industrially relevant optically pure α-arylpropionates. Historical perspectives as well as recent achievements in the field will be covered within this work.
{"title":"Arylmalonate Decarboxylase—A Versatile Biocatalyst for the Synthesis of Optically Pure Carboxylic Acids","authors":"A. Schweiger, K. Miyamoto, R. Kourist","doi":"10.3389/fctls.2021.742024","DOIUrl":"https://doi.org/10.3389/fctls.2021.742024","url":null,"abstract":"Bacterial arylmalonate decarboxylase (AMDase) is an intriguing cofactor-independent enzyme with a broad substrate spectrum. Particularly, the highly stereoselective transformation of diverse arylmalonic acids into the corresponding chiral α-arylpropionates has contributed to the broad recognition of this biocatalyst. While, more than 30 years after its discovery, the native substrate and function of AMDase still remain undiscovered, contributions from multiple fields have ever since brought forth a powerful collection of AMDase variants to access a wide variety of optically pure α-substituted propionates. This review aims at providing a comprehensive overview of the development of AMDase from an enzyme with unknown function up to a powerful tailored biocatalyst for the synthesis of industrially relevant optically pure α-arylpropionates. Historical perspectives as well as recent achievements in the field will be covered within this work.","PeriodicalId":73071,"journal":{"name":"Frontiers in catalysis","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46026277","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-07-19DOI: 10.3389/fctls.2021.715075
Javier Santiago-Arcos, Susana Velasco-Lozano, E. Diamanti, A. Cortajarena, F. López‐Gallego
Alcohol dehydrogenase from Bacillus (Geobacillus) stearothermophilus (BsADH) is a NADH-dependent enzyme catalyzing the oxidation of alcohols, however its thermal and operational stabilities are too low for its long-term use under non-physiological conditions. Enzyme immobilizations emerges as an attractive tool to enhance the stability of this enzyme. In this work, we have screened a battery of porous carriers and immobilization chemistries to enhance the robustness of a His-tagged variant of BsADH. The selected carriers recovered close to 50% of the immobilized activity and increased enzyme stability from 3 to 9 times compared to the free enzyme. We found a trade-off between the half-life time and the specific activity as a function of the relative anisotropy values of the immobilized enzymes, suggesting that both properties are oppositely related to the enzyme mobility (rotational tumbling). The most thermally stable heterogeneous biocatalysts were coupled with a NADH oxidase/catalase pair co-immobilized on porous agarose beads to perform the batch oxidation of five different 1,ω-diols with in situ recycling of NAD+. Only when His-tagged BsADH was immobilized on porous glass functionalized with Fe3+, the heterogeneous biocatalyst oxidized 1, 5-pentanediol with a conversion higher than 50% after five batch cycles. This immobilized multi-enzyme system presented promising enzymatic productivities towards the oxidation of three different diols. Hence, this strategical study accompanied by a functional and structural characterization of the resulting immobilized enzymes, allowed us selecting an optimal heterogeneous biocatalyst and their integration into a fully heterogeneous multi-enzyme system.
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