Solid/gas biocatalysis

Kulishova, Liliya; Zharkov, Dmitry O.

doi:10.1134/s000629791702002x

“…The gas-phase bioproduction of monoterpenoids overcomes this drawback of the liquid-phase bioproduction because the reaction proceeds with the passive supply of gaseous substrates. However, application of gas-phase bioproduction has been limited to simple compounds 43 . In particular, for gas-phase production using whole cell biocatalysts, only epoxidation reactions from simple C2 and C3 alkenes have been reported 44,45 .…”

Section: Discussionmentioning

confidence: 99%

“…Furthermore, it should be noted that the regio-and stereo-selective production of (E)-Cell immobilization is essential for the construction of a gas-phase bioproduction system. To date, entrapment into aqueous gels, covalent cross-linking to the surface of support, and physical attachment to material surfaces have been employed as cell immobilization methods 43 . Generally, these methods are inefficient in gas-phase reactions due to mass transfer limitations, deactivation of cells, and the insufficient mass of immobilized biocatalysts.…”

Section: Discussionmentioning

confidence: 99%

Gas-Phase Bioproduction of a High-Value-Added Monoterpenoid (E)-Geranic Acid by Metabolically Engineered Acinetobacter Sp. Tol 5

Usami¹,

Ishikawa²,

Hori

³

2019

Preprint

View full text Add to dashboard Cite

Gas-phase bioproduction, in which immobilized biocatalysts are employed and chemical reactions are performed in a gas phase, has attracted researchers’ attention as a green process. However, there is difficulty in the employment of whole cell catalysts for gas-phase bioproduction due to the lack of a suitable cell immobilization method. Acinetobacter sp. Tol 5 is a unique bacterium, which is remarkably sticky and can be easily immobilized onto various material surfaces through the adhesive bacterionanofiber protein AtaA. In this study, we demonstrate the gas-phase bioproduction of (E)-geranic acid (GA), a high-value-added monoterpenoid, from geraniol using immobilized Tol 5 transformant cells, into which a gene involved in a (E)-GA synthetic pathway was introduced. Time course analysis of the liquid-phase bioproduction of (E)-GA revealed the inherent metabolism of Tol 5 involved in the degradation of (E)-GA. By disrupting the fadD4-ortholog gene, which encodes a key enzyme of the (E)-GA degradation, we successfully generated a (E)-GA-accumulating strain, Tol 5 ΔfadD4 (pGeoA). The immobilized cells of this mutant strain on a polyurethane support enabled the production of (E)-GA with a passive supply of gaseous geraniol in a batch gas-phase reaction. A major fraction of the (E)-GA, which was produced, was adsorbed onto the polyurethane support but easily extracted into ethanol, a safe solvent without environmental impact. This is the first example of gas-phase bioproduction of a complex and high-value-added compound. Tol 5 is a highly promising platform for gas-phase bioproduction.

show abstract

“…Cell immobilization is essential for the construction of a gas-phase bioproduction system. To date, entrapment into aqueous gels, covalent cross-linking to the surface of support, and physical attachment to material surfaces have been employed as cell immobilization methods 43 . Generally, these methods are inefficient in gas-phase reactions due to mass transfer limitations, deactivation of cells, and the insufficient mass of immobilized biocatalysts.…”

Section: Discussionmentioning

confidence: 99%

Gas-Phase Bioproduction of a High-Value-Added Monoterpenoid (E)-Geranic Acid by Metabolically Engineered Acinetobacter Sp. Tol 5

Usami¹,

Ishikawa²,

Hori³

2019

Preprint

0

View full text Add to dashboard Cite

Gas-phase bioproduction, in which immobilized biocatalysts are employed and chemical reactions are performed in a gas phase, has attracted researchers’ attention as a green process. However, there is difficulty in the employment of whole cell catalysts for gas-phase bioproduction due to the lack of a suitable cell immobilization method. Acinetobacter sp. Tol 5 is a unique bacterium, which is remarkably sticky and can be easily immobilized onto various material surfaces through the adhesive bacterionanofiber protein AtaA. In this study, we demonstrate the gas-phase bioproduction of (E)-geranic acid (GA), a high-value-added monoterpenoid, from geraniol using immobilized Tol 5 transformant cells, into which a gene involved in a (E)-GA synthetic pathway was introduced. Time course analysis of the liquid-phase bioproduction of (E)-GA revealed the inherent metabolism of Tol 5 involved in the degradation of (E)-GA. By disrupting the fadD4-ortholog gene, which encodes a key enzyme of the (E)-GA degradation, we successfully generated a (E)-GA-accumulating strain, Tol 5 ΔfadD4 (pGeoA). The immobilized cells of this mutant strain on a polyurethane support enabled the production of (E)-GA with a passive supply of gaseous geraniol in a batch gas-phase reaction. A major fraction of the (E)-GA, which was produced, was adsorbed onto the polyurethane support but easily extracted into ethanol, a safe solvent without environmental impact. This is the first example of gas-phase bioproduction of a complex and high-value-added compound. Tol 5 is a highly promising platform for gas-phase bioproduction.

show abstract

“…Figures 8 and 9 illustrate the effect of the variable convective velocity (the diffusion coefficient was kept constant) on the concentration distribution across the membrane, while Figure 10 plots the effect of the reaction modulus. The variation of the linear velocity can often occur during the gas phase reaction, which can be true to solid-gas biocatalytic processes as well [33] The change of the volumetric/linear velocity can take place not only inside a membrane layer, but in the lumen or shell fluid phases of a capillary membrane or in traditional reactors as well. Let us look at a simple reaction, e.g., the reaction of oxygen with hydrogen into a water molecule:…”

Section: Mass Transport With Variable Mass Transport Parametersmentioning

confidence: 99%

Analysis of Mass Transport through Anisotropic, Catalytic/Bio-Catalytic Membrane Reactors

Nagy

¹

,

Vitai

²

2019

View full text Add to dashboard Cite

This paper investigated the steady-state mass transport process through anisotropic, composite membrane layers with variable mass transport coefficients, such as the diffusion coefficient, convective velocity, or chemical/biochemical reaction rate constant. The transfer processes can be a solution-diffusion model or diffusive plus convective process. In the theoretical part, the concentration distribution as well as the inlet and outlet mass transfer rates’ expressions are defined for physical transport processes with variable diffusion or solubility coefficients and then that for transport processes accompanied by first- and zero-order reactions, in the presence of diffusive and convective flow, with constant and variable parameters. The variation of the transport parameters as a function of the local coordinate was defined by linear equations. It was shown that the increasing diffusion coefficient or convective flow induces much lower concentrations across the membrane layer than transport processes, with their decreasing values a function of the space coordinate. Accordingly, this can strongly affect the effect of the concentration dependent chemical/biochemical reaction. The inlet mass transfer rate can also be mostly higher when the transport parameter decreases across the anisotropic membrane layer.

show abstract

Solid/gas biocatalysis

Cited by 8 publications

References 87 publications

Gas-Phase Bioproduction of a High-Value-Added Monoterpenoid (E)-Geranic Acid by Metabolically Engineered Acinetobacter Sp. Tol 5

Gas-Phase Bioproduction of a High-Value-Added Monoterpenoid (E)-Geranic Acid by Metabolically Engineered Acinetobacter Sp. Tol 5

Gas-Phase Bioproduction of a High-Value-Added Monoterpenoid (E)-Geranic Acid by Metabolically Engineered Acinetobacter Sp. Tol 5

Analysis of Mass Transport through Anisotropic, Catalytic/Bio-Catalytic Membrane Reactors

Contact Info

Product

Resources

About