Estimation of the Effectiveness Factor for Immobilized Enzyme Catalysts through a Simple Conversion Assay

Abstract

A novel methodology to estimate the effectiveness factor (EF) of an immobilized enzyme catalyst is proposed here. The methodology consists of the determination of the productivity of both the immobilized enzyme catalyst and its corresponding soluble enzyme, plotted as a function of the reaction conversion. The ratio of these productivities corresponds to the EF estimator of the catalyst. Conversion curves were simulated in a batch reactor with immobilized enzyme and soluble enzyme for different values of the S0/KM ratio and Thiele modulus (Φ) to demonstrate this hypothesis. Two different reaction orders were tested: first-order kinetic and Michaelis–Menten-based kinetic with product inhibition. The results showed that the ratio of productivities between the immobilized and soluble enzymes followed the behavior profile presented by the EF with satisfactory agreement. This simple methodology to estimate the EF is based on routine conversion experiments, thus avoiding the exhaustive kinetic and mass transfer characterization of the immobilized enzyme catalyst.

Thiolation of Myco-Synthesized Fe3O4-NPs: A Novel Promising Tool for Penicillium expansium Laccase Immobilization to Decolorize Textile Dyes and as an Application for Anticancer Agent

“…Fe 3 O 4 -NP s /3-MPA-S-S-Laccase The diffusional coefficient (D C ) was calculated by dividing the V max value of the immobilized enzyme over the V max value of the free enzyme and used to express the magnitude of mass transfer using different substrates, namely ABTS and catechol. The diffusional coefficient was respectively found to be 0.92 and 1.05 for ABTS and catechol, which was linked to the easy accessibility (D C value more than 1.0) of the substrate into the immobilized enzyme beads [44,45].…”

Developing Enzyme Immobilization with Fibrous Membranes: Longevity and Characterization Considerations

“…Mathematical treatments of mass transfer phenomena that incorporate both diffusion and reaction have been developed [ 76 , 77 , 78 , 79 ], and elaborated in detail, depending on specific reactor configurations, such as for porous gas–liquid hollow fiber membrane contactors, where an enhancement factor (E = V catalyzed /V uncatalyzed ) can be incorporated to account for improvements in mass transfer due to the (bio-catalyzed) chemical reaction [ 80 ]. Simplified process metrics (namely “productivity”, Table 2 ) are reported when the detailed parameters needed for solving mathematical models are unknown [ 81 ]. Kinetic parameters impacting immobilized catalysts may change for multiple reasons, such as steric exclusion between support materials and enzyme substrates, delayed diffusion to interior pores of porous media, and changes in driving forces, such as concentration gradients induced by mixing or flow, that deliver substrates to or separate products from the catalytic matrix [ 74 ].…”

“…High affinity between support materials and enzymes occurs through intermolecular interactions between enzymes and reactive chemical functional groups in the physical supports. Both native [ 7 , 8 ] and chemically introduced [ 37 , 48 , 81 , 104 , 105 , 106 ] amine groups (–NH 2 ) are frequently used to physically or chemically attach enzyme molecules for immobilization purposes. Bagheri et al achieved robust immobilization by utilizing spherical dendrimers with multiple amine end groups to covalently attach enzymes to a film surface [ 36 ].…”

“…Bagheri et al achieved robust immobilization by utilizing spherical dendrimers with multiple amine end groups to covalently attach enzymes to a film surface [ 36 ]. Oxygen-containing functional groups, such as hydroxyl (–OH) and carbonyl groups (C=O), have been used for direct enzyme immobilization [ 32 , 74 ], as well as primers to introduce other chemical groups for immobilization [ 30 , 48 , 81 , 98 ]. Methods such as oxidation [ 30 , 48 ], chemical treatment [ 31 , 32 ], or plasma activation [ 106 ] are used to activate hydroxyl groups.…”

Generalized Linear Driving Force Formulas for Diffusion and Reaction in Porous Catalysts

“…The applicability range of the models is broad. It starts from the effectiveness factor value determination for both steady-state and transient problems [12][13][14][15][16] by finding approximate analytical or numerical solutions for models in chemical or biochemical fields [17][18][19][20][21][22][23][24] and ending with using the approximate model as part of a more complex model, for example, for a heterogeneous or biochemical reactor [25][26][27][28][29][30][31]. The examples presented are only the selection, and they indicate that the area of application of approximate models is large and still enlarges.…”