Immobilized Glucose Isomerase Research Articles

Reaction and Kinetics in Immobilized Glucose Isomerase of Packed-Bed Reactors Using Akbari-Ganji’s Method

Reaction and Kinetics in Immobilized Glucose Isomerase of Packed-Bed Reactors Using Akbari-Ganji’s Method

Reactor development for a one‐step hybrid catalytic conversion of D‐glucose to HMF

AbstractThe design of an “H”‐shaped reactor has been studied to satisfy the possibility of using a triphasic medium to transform d‐glucose into 5‐hydroxymethylfurfural (HMF) by a hybrid catalytic process using an immobilized glucose isomerase, allowing the isomerization of D‐glucose to d‐fructose, and a heterogeneous chemical catalyst to catalyze the dehydration of d‐fructose to HMF. The various parameters influencing the transport of d‐fructose within the reactor were studied, namely the difference in pH between the two aqueous phases, the agitation and the quantity of 3,4‐DCPBA/Aliquat336® used to extract and transport continuously the d‐fructose. The pH discrepancy, which must be between 5.0 and 5.5, turns out to be the real driving force behind the extraction of D‐fructose. The D‐Fru/3,4‐DCPBA molar ratio of 1/0.25 allowed the transport of more than 80 % of the D‐fructose initially present and shows that the same molecule of 3,4‐DCPBA is involved at least twice in the transport of D‐fructose and that the 3,4‐DCPBA/Aliquat336® couple performs a turnover within the organic phase. Finally, a HMF production yield of 30.9 % and an isomerization yield of 79.1 % were obtained, illustrating the shift in the isomerization equilibrium made possible by a D‐fructose extraction yield of 96.8 %.

Modeling glucose isomerization in a packed- bed reactor: A complete theoretical and numerical approach

Immobilized enzymes are used in many applications in the food industry presently. Some researchers employ apparent kinetic parameters in immobilized enzyme reactor systems, which only apply to these specific case studies. To increase productivity in a packed bed reactor, it is vital to establish a thorough understanding of all the factors affecting the process, including axial dispersion, convective mass transport, intra-particle diffusive mass transfer, and kinetics. This paper discusses the packed-bed reactor's steady-state model of immobilized glucose isomerase. This model is based on a nonlinear reaction-diffusion equation containing nonlinear terms associated with the enzymatic reaction of Michaelis–Menten kinetics. Akbari-Ganji's method (AGM) and Taylors series with Pade's approximation method are used to calculate the species concentration and normalized current for all possible kinetic parameters and Thiele modulus. The saturated and unsaturated kinetics also have been investigated analytically. A significant agreement between the simulation results and the analytical expression of concentration is observed.

Carbohydrate microcapsules tailored and grafted for covalent immobilization of glucose isomerase for pharmaceutical and food industries.

Carrageenan is one of the most common carbohydrates utilised in the entrapment industry to immobilise cells and enzymes. However, it lacks functionality. Carrageenan has been grafted to produce fructose by covalently immobilising glucose isomerase (GI). Fructose is one of the most widely used sweeteners in beverages, food production, and the pharmaceutical business. Up to 91.1 U g-1 gel beads are immobilised by the grafted beads. Immobilized GI has a Vmax of 13.8 times that of the free enzyme. pH of immobilized GI was improved from 6.5-7 to 6-7.5 that means more stability in wide pH range. Also, optimum temperature was improved and become 65-75°C while it was at 70°C for free enzyme. The immovability and tolerance of the gel beads immobilised with GI over 15 consecutive cycles were demonstrated in a reusability test, with 88 percent of the enzyme's original activity retained, compared to 60 percent by other authors. These findings are encouraging for high-fructose corn syrup producers.

Approximate Analytical Solution to a Pore Network Model of Deactivation of Immobilized Glucose Isomerase in Packed-Bed Reactors Using Akbari-Ganji’s Method

The main objective of this paper is to derive an approximate analytical solution for the mathematical model pertaining to deactivation of immobilized glucose in packed-bed reactors. The Akbari-Ganji’s method is applied to solve the previously developed mathematical model. The approximate analytical expressions corresponding to the concentration and current in the steady state condition have been derived for all values of parameters. Excellent agreement is obtained between the analytical solution and the numerical simulation. The analytical solution presented in this paper is presented for the first time. The results of this work will provide a better understanding of the mathematical model examined.

Novel Recyclable UCST-Type Immobilized Glucose Isomerase Biocatalyst with Excellent Performance for Isomerization of Glucose to Fructose.

The development of a suitable immobilization strategy to improve the performance of immobilized glucose isomerase for the isomerization of glucose to fructose is crucial to promoting the industrial production of high-fructose syrup. In this work, a novel recyclable upper critical solution temperature (UCST)-type mVBA-b-P(AAm-co-AN)@glucose isomerase biocatalyst (PVAA@GI) was prepared, and the immobilized glucose isomerase could capture the glucose substrate through the affinity of 4-vinylbenzeneboronic acid (4-VBA) and the glucose substrate, which led to the enhanced substrate affinity and catalytic efficiency of the PVAA@GI. The biocatalyst exhibited excellent stability in pH, thermal, storage, and recycling compared to the free enzyme. The mVBA-b-P(AAm-co-AN)@glucose isomerase biocatalyst displayed reversibly soluble-insoluble characteristics with temperature change, which was in the soluble state during the enzyme reaction process but could be recovered in an insoluble form by lowering the temperature after the reaction. The highest fructose production rate reached 62.79%, which would have potential application in the industrial production of high-fructose syrup.

D-Allulose (d-psicose) biotransformation from d-glucose, separation by simulated moving bed chromatography (SMBC) and purification by crystallization

d-Allulose (or d-Psicose), a C-3 epimer of d-fructose, is a low-calorie rare sugar with excellent physiological functions. The recombinant Escherichia coli expressing d-allulose 3-epimerase for d-allulose conversion from d-fructose was constructed. Under the optimal conditions, 139.3 g/L d-allulose was produced from 500 g/L of d-fructose. In order to decrease the cost for mass production, one-pot reaction method by using immobilized glucose isomerase and recombinant E. coli expressing d-allulose 3-epimerase to produce d-allulose from d-glucose was developed. The immobilized glucose isomerase (200 g/L) and the recombinant E. coli cells (OD600 2) were mixed and used to transform d-glucose into d-allulose, and 228.5 g/L d-glucose, 216.3 g/L d-fructose and 90.7 g/L d-allulose were obtained from 550 g/L d-glucose after 3 h reaction. After that, d-allulose was separated from the reaction mixture by using simulated moving bed chromatography (SMBC) with the purity of 99.6%. Finally, crystallization was made to obtain the d-allulose crystals with 99.8% purity. The combination of enzyme and catalytic cells in biotransformation greatly expand the flexibility and capability of the catalytic reactions. This method developed in this study can be easily scaled up for mass production of highly purified d-allulose.

Bioconversion of Lactose into Glucose-Galactose Syrup by Two-Stage Enzymatic Hydrolysis.

Fermentation technology enables the better use of resources and the conversion of dairy waste into valuable food products. The aim of this study is to evaluate the conversion rate of glucose into fructose by immobilised glucose isomerase (GI) in sweet and acid whey permeates for glucose–galactose syrup production. The experiments demonstrated that the highest concentration of glucose and galacto-oligosaccharides (GOSs) in sweet and acid whey permeates was reached by GODO-YNL2 β-galactosidase, 32 ± 2% and 28 ± 1%, respectively. After glucose isomerisation, the highest fructose yield was 23 ± 0.3% and 13 ± 0.4% in sweet and acid whey permeates, where Ha-Lactase 5200 β-galactosidase was used for lactose hydrolysis in sweet and acid whey permeates. Finally, the results of this study highlight the potential for two-stage enzymatic hydrolysis to increase the sweetness of glucose–galactose syrup made from sweet and acid whey permeates.

Optimization for allitol production from d-glucose by using immobilized glucose isomerase and recombinant E. coli expressing d-psicose-3-epimerase, ribitol dehydrogenase and formate dehydrogenase

To develop a method combining enzymatic catalysis and resting-cell biotransformation to produce allitol from low cost substrate D-glucose. The recombinant E. coli expressing D-psicose-3-epimerase (DPE), ribitol dehydrogenase (RDH) and formate dehydrogenase (FDH) for allitol production from D-fructose was constructed. The optimizations of the cell catalytic conditions and the cell cultivation conditions were made. Then, 63.4 g allitol L-1 was obtained from 100 g D-fructose L-1 in 4 h catalyzed by the recombinant E. coli cells. In order to decrease the substrate cost, D-glucose was used as the substrate instead of D-fructose and immobilized glucose isomerase was used to convert D-glucose into D-fructose. In order to simplify allitol production process from D-glucose, one-pot reaction using the mixed catalysts was used and the reaction conditions were optimized. Finally, 12.7 g allitol L-1 was obtained from 50 g D-glucose L-1 catalyzed by the mixed catalysts of immobilized glucose isomerase and the recombinant E. coli cells. Allitol can be efficiently produced from low cost substrate D-glucose by using the method combining enzymatic catalysis and resting-cell biotransformation, which is the first report.

Optimization of simultaneous saccharification and isomerization of dextrin to high fructose syrup using a mixture of immobilized amyloglucosidase and glucose isomerase

High fructose syrup is a sweetener widely used as a substitute for sucrose in the food and beverage industry with its current industrial production being carried out in three sequential processes using three different enzymes that operate under different pH and temperature conditions. In this study, a single step synergistic saccharification and isomerization process has been proposed, using the commercial amyloglucosidase from Aspergillus niger immobilized by the CLEA technique (co-aggregated with magnetic nanoparticles and polyethyleneimine), and the commercial immobilized glucose isomerase (IGI) from Streptomyces murinus, Sweetzyme® IT Extra. Immobilization stabilized both enzymes, widening the operation window, thus, by applying a factorial design with a central composite rotatable design it was possible to define an optimal condition of pH and temperature of the process, as well as the best ratio between the two enzymes (pH 5.7, 50 °C and UGI/UAMG ratio of 1.56). Simultaneous saccharification and isomerization of 35 % (w/v) dextrin solution produced a Dextrose Equivalent yield over 95 %, with a glucose-to-fructose conversion around 48 % after 30 h of reaction. In addition, both biocatalysts could be reused for six consecutive cycles, maintaining glucose-to-fructose conversions without loss of activity and with easy recovery of the biocatalysts. Furthermore, because they are of different natures (magnetic CLEA of amyloglucosidase and non-magnetic IGI pellets), if one of these biocatalysts is inactivated, they can be easily separated and reloaded individually.

Design of operational temperature for immobilized glucose isomerise using an accelerated inactivation method

Abstract Thermal inactivation of immobilized glucose isomerase in a concentrated glucose solution was investigated in the batch mode and temperature range of 83–95 °C, which is substantially higher than the temperature used in the industrial production of high-fructose corn syrup. Simultaneous evaluation of all inactivation data showed that first-order kinetics with the Arrhenius temperature dependence of the rate constant provided a good approximation of the biocatalyst stability under the investigated conditions. The model parameters were then used to predict the operational temperature for this biocatalyst in the production of high-fructose corn syrup based on the set operational life-time of the biocatalyst. The simulation predicted a window of operational temperature of 60–65 °C, which corresponds very well with the industrial applications of this biocatalyst. This observation demonstrates that the multi-temperature method of enzyme inactivation can provide a good estimate of biocatalyst process stability and is thus a useful tool in the development of biocatalytic processes.

From a Sequential Chemo-Enzymatic Approach to a Continuous Process for HMF Production from Glucose

Notably available from the cellulose contained in lignocellulosic biomass, glucose is a highly attractive substrate for eco-efficient processes towards high-value chemicals. A recent strategy for biomass valorization consists on combining biocatalysis and chemocatalysis to realise the so-called chemo-enzymatic or hybrid catalysis. Optimisation of the glucose conversion to 5-hydroxymethylfurfural (HMF) is the object of many research efforts. HMF can be produced by chemo-catalyzed fructose dehydration, while fructose can be selectively obtained from enzymatic glucose isomerization. Despite recent advances in HMF production, a fully integrated efficient process remains to be demonstrated. Our innovative approach consists on a continuous process involving enzymatic glucose isomerization, selective arylboronic-acid mediated fructose complexation/transportation, and chemical fructose dehydration to HMF. We designed a novel reactor based on two aqueous phases dynamically connected via an organic liquid membrane, which enabled substantial enhancement of glucose conversion (70%) while avoiding intermediate separation steps. Furthermore, in the as-combined steps, the use of an immobilized glucose isomerase and an acidic resin facilitates catalyst recycling.

Enzymatic fructose removal from D‐psicose bioproduction model solution and the system modeling and simulation

AbstractBACKGROUNDThe rare sugar D‐psicose has important physiological functions, and has been used as an ingredient in foods and dietary supplements. It can be mass produced from D‐fructose in industry. However, separation of D‐psicose from D‐fructose is difficult.RESULTSIn this research, a reaction purification system consisting of two continuous stirred tank reactors (CSTR) containing immobilized glucose isomerase (GI) and glucose oxidase (GOD), respectively, for D‐fructose removal was constructed. Using this system D‐fructose was transformed into gluconic acid and separated from D‐psicose easily using anion exchange resin. Modeling and simulation was carried out for this system and the model was verified by experiments and used in process predictions.CONCLUSIOND‐Psicose can be efficiently purified using the proposed reaction purification system. The final purity of the D‐psicose is 91.2%, which meets the need for crystallization to obtain highly purified product. The mathematical model developed for this system can simulate and predict the process well, which is useful in process analysis, prediction, and optimization to save time and costs compared with laboratory experiments. © 2017 Society of Chemical Industry

Immobilization of Recombinant Glucose Isomerase for Efficient Production of High Fructose Corn Syrup.

Glucose isomerase is the important enzyme for the production of high fructose corn syrup (HFCS). One-step production of HFCS containing more than 55% fructose (HFCS-55) is receiving much attention for its industrial applications. In this work, the Escherichia coli harboring glucose isomerase mutant TEGI-W139F/V186T was immobilized for efficient production of HFCS-55. The immobilization conditions were optimized, and the maximum enzyme activity recovery of 92% was obtained. The immobilized glucose isomerase showed higher pH, temperature, and operational stabilities with a K m value of 272mM and maximum reaction rate of 23.8mMmin-1. The fructose concentration still retained above 55% after the immobilized glucose isomerase was reused for 10cycles, and more than 85% of its initial activity was reserved even after 15 recycles of usage at temperature of 90°C. The results highlighted the immobilized glucose isomerase as a potential biocatalyst for HFCS-55 production.

Wavelet-Based Analytical Algorithm for Solving Steady-State Concentration in Immobilized Glucose Isomerase of Packed-Bed Reactor Model.

Wavelet method is a recently developed tool in applied mathematics. The mathematical model of the steady-state immobilized enzyme electrodes is discussed. This theoretical model is based on one-dimensional heat conduction equations containing a non-linear term related to Michaelis-Menten kinetics. An efficient Chebyshev wavelet-based technique is applied to solve the non-linear diffusion equation for the steady-state condition. A simple expression of the substrate concentration is obtained as a function of the Thiele modulus [Formula: see text] and [Formula: see text](kinetic parameter). The wavelet results are compared with the numerical and HPM solutions and found to be in good agreement.

Software Sensor to Enhance Production of Fructose

Present studies describe the on-line prediction of fructose concentration by using Artificial Neural Network (ANN) that employed as software sensor in the batch reactor for the biosynthesis of fructose by Immobilised Glucose Isomerase (IGI) of S.murinus. The process of fermentation was carried out in a 2-L batch bioreactor (New Brunswick Scientific, USA) with a working volume of 1.5 L reactor. All of the parameters were automatically controlled with the help of attached software. The optimum pH and temperature, for the production of fructose by Immmobilised Glucose Isomerase (IGI) of S.murinus were found to be 8 and 60 o C, respectively. Accuracy of the proposed soft sensor was calculated by the correlation coefficient (R 2 ) and mean square error (MSE). In this study, value R 2 were greater than 0.95 and the values of MSE were less than 0.2, indicating a good fit of the ANN-soft sensor to the experimental data, accurate up to 95.7% for training and 100% for testing. Thus, the proposed ANN-soft sensor was the most precise in predicting fructose concentration.

Application of a novel type impinging streams reactor in solid–liquid enzyme reactions and modeling of residence time distribution using GDB model

Solid–liquid enzyme reactions constitute important processes in biochemical industries. The isomerization of d-glucose to d-fructose, using the immobilized glucose isomerase (Sweetzyme T), as a typical example of solid–liquid catalyzed reactions has been carried out in one stage and multi-stage novel type of impinging streams reactors. Response surface methodology was applied to determine the effects of certain pertinent parameters of the process namely axial velocity (A), feed concentration (B), nozzles’ flow rates (C) and enzyme loading (D) on the performance of the apparatus. The results obtained from the conversion of glucose in this reactor were much higher than those expected in conventional reactors, while residence time was decreased dramatically. Residence time distribution (RTD) in a one-stage impinging streams reactor was investigated using colored solution as the tracer. The results showed that the flow pattern in the reactor was close to that in a continuous stirred tank reactor (CSTR). Based on the analysis of flow region in the reactor, gamma distribution model with bypass (GDB) was applied to study the RTD of the reactor. The results indicated that RTD in the impinging streams reactor could be described by the latter model.

Comparison Study of Experimental and Simulation in the Glucose Isomerisation Process in a Fixed-Bed Reactor

Production of fructose from glucose isomerisation process using commercial immobilized glucose isomerase (IGI) was conducted in a fixed-bed bioreactor. A semi-empirical kinetic model based on the mechanism of the glucose isomerisation process has been proposed. The values of maximum rate of reaction, Vm ,g L-1 min-1 are (1.82, 1.86, 1.93 and 0.37), for Michaelis-Menten constant Km, g L-1 the values are (1.04, 1.11, 1.24 and 0.35). In this modified model, known as MM3 the variation of temperature, pH, and initial substrate concentration, feed flow rates have been taken into account. The validation of the models with experimental data was checked in terms of AAE and R2. The values of correlation coefficient, R2 (> 0.95) indicated that MM3 model was well fitted to the experimental data.

Optimization of lactulose synthesis from whey lactose by immobilized β-galactosidase and glucose isomerase

In the present study, commercially available whey was used as a lactose source, and immobilized β-galactosidase and glucose isomerase were used to synthesize lactulose from whey lactose in the absence of fructose. Optimal reaction conditions, such as lactose concentration, temperature, ionic strength of the buffer, and ratio of immobilized enzymes, were determined to improve lactulose synthesis using immobilized enzymes. Lactulose synthesis using immobilized enzymes improved markedly after optimizing the reaction conditions. When the lactulose synthesis was carried out at 53.5°C using 20% (w/v) whey lactose, 12U/ml of immobilized β-galactosidase and 60U/ml of immobilized glucose isomerase in 100mM sodium phosphate buffer at pH 7.5, the lactulose concentration and specific productivity were 7.68g/l and 0.32mg/Uh, respectively. Additionally, when the immobilized enzymes were reused for lactulose synthesis, their catalytic activity was 57.1% after 7 repeated uses.

Chemo‐Enzymatic Conversion of Glucose into 5‐Hydroxymethylfurfural in Seawater

Do you sea water? Water consumption will be a challenge in biorefineries, and the use of non-drinkable sources of water will be preferred. Herein, glucose is converted into 5-hydroxymethylfurfural (HMF) in a chemo-enzymatic one-pot, two-step procedure, involving immobilized glucose isomerase to produce fructose and oxalic acid to dehydrate it to HMF.