Resin Beads Research Articles

Hybrid extractive scintillator resin for simultaneous concentration and detection of plutonium from aqueous solutions

A scoping study of a commercially available resin selective for aqueous plutonium (Pu), AnaLig® Pu-02, modified with scintillator was investigated as a scheme to simultaneously concentrate and detect Pu in aquatic matrices. The extractive scintillating resin was comprised of a silica base, functionalized for plutonium extraction, grafted with plastic scintillator of polyvinyl toluene (PVT) and 2-(1-naphthyl)-4-vinyl-5- phenyloxazole (vNPO) fluor. Scintillator was incorporated onto the AnaLig® Pu-02 resin in a two-step process of silanization followed by surface-polymerization. Successful modification was facilitated by grinding the resin beads prior to silanization to expose cleaved silica surface sites appropriate for scintillator grafting. The modified resin was subjected to initial characterization of batch uptake and radioluminosity measurements where a total detection efficiency of 32.5% was observed. The modified resin was then subjected to pH 1 simulants containing environmental relevant groundwater constituents of varying concentration. Concentrations of 0.001M Fe(III) interfered with Pu uptake, while concentrations of up to 0.01M Ca(II) and 0.001 mM concentration of natural uranium and thorium had minimal influence on plutonium uptake. A translucent column packed with the modified AnaLig® Pu-02 was placed in a commercial flow-cell radiation detector for real-time detection of plutonium; a total detection efficiency of 20.4% was achieved for on-line measurements. The modification of AnaLig® Pu-02 results in a minimum detection limit capable of meeting the EPA limit for gross alpha activity in drinking water given a sufficient counting time of 15 min and approximately 300 mL of solution volume.

Metakaolin-Reinforced Sulfoaluminate-Cement-Solidified Wasteforms of Spent Radioactive Resins—Optimization by a Mixture Design

Cement solidification is a main technique for radioactive waste treatment to reduce its risk to the environment and human health. However, this method underperforms when dealing with spent radioactive ion-exchange resin, taking much space, and costing much money for final disposal. In this work, simulated spent radioactive resin was solidified using a metakaolin-reinforced sulfoaluminate cement system, which was optimized by a mixture design based on the effects of components and parameters, and the durability of solidified wasteforms was assessed in terms of strength and Cs(I) leaching. Solidified by an optimized formula of 40 wt.% spent resin, 55.8 wt.% sulfoaluminate cement, 2.2 wt.% metakaolin, and 2 wt.% water reducer, the resin loading in wasteforms reached 64% and the compressive strength 13.7 MPa. The dominant mineral phases of hydration products were ettringite crystalline of acicular and columnar morphology, with small amounts of scattered amorphous clusters of aluminum gels and C–S–H gels. Metakaolin, a source of aluminum, promoted the growth of ettringite, which facilitated (1) the encapsulation of resin beads with high strengths, even in acidic environments or during frequent freezing-thawing, and (2) the retention of Cs(I), with a 42 day leaching rate of 2.3 × 10−4 cm/day. This work offers a technical justification for spent resin solidification in the metakaolin-reinforced sulfoaluminate cement system, which is an applicational solution for the efficient treatment of radioactive waste.

Combined effects of copper oxide and nickel oxide coated chitosan nanoparticles adsorbed to styrofoam resin beads on hydrothermal vent bacteria

Microplastics are potential carriers of harmful contaminants but their combined effects are largely unknown. It needs intensive monitoring in order to achieve a better understanding of metal-oxide nanoparticles and their dispersion via microplastics such as styrofoam in the aquatic environment. In the present study, an effort was made to provide a preferable perception about the toxic effects of engineered nanoparticles (NPs), namely, copper oxide (CuO NPs), nickel oxide (NiO NPs), copper oxide/chitosan (CuO/CS NPs) and nickel oxide/chitosan (NiO/CS NPs). Characterizations of synthesized NPs included their morphology (SEM and EDX), functional groups (FT-IR) and crystallinity (XRD). Their combined toxic effect after adsorption to styrofoam (SF) was monitored using the hydrothermal vent bacterium Jeotgalicoccus huakuii as a model. This was done by determining MIC (minimum inhibitory concentration) through a resazurin assay measuring ELISA, growth, biofilm inhibition and making a live and dead assay. Results revealed that at high concentrations (60 mg/10 mL) of CuO, CuO/CS NPs and 60 mg of SF adsorbed CuO and CuO/CS NPs inhibited the growth of J. huakuii. However, NPs rather than SF inhibited the growth of bacteria. The toxicity of NPs adsorbed on plain SF was found to be less compared to NPs alone. This study revealed new dimensions regarding the positive impacts of SF at low concentrations. Synthesized NPs applied separately were found to affect the growth of bacteria substantially more than if coated to SF resin beads.

Binderless zeolite LTA beads with hierarchical porosity for selective CO2 adsorption in biogas upgrading

In the context of CO2 removal from biogas, a series of binderless zeolite LTA adsorbents with a macroscopic bead format (0.5–1.0 mm) and with hierarchical porosity (i.e. with the zeolitic micropores being accessible through meso- and macropores mainly in the 10–100 nm range) was synthesized with a variety of Si/Al ratios (1.2–3.9) using Amberlite IRA-900 anion-exchange resin beads as a hard template. The CO2 and CH4 adsorption capacity of the beads in Na-form with different Si/Al ratios were measured, reaching higher CO2/CH4 selectivity and similar, yet slightly higher CO2 adsorption compared to commercial zeolite LTA pellets containing a binder. Subsequently, one the zeolitic beads was subjected to different degrees of ion-exchange (0–96%) with KCl and then tested in the adsorption of CO2 and CH4. The best performance among all the ion-exchanged beads was achieved with Na58K42-LTA beads, which gave very high CO2/CH4 selectivity (1540). Although essentially no CH4 was adsorbed on these beads, the CO2 adsorption capacity was still substantial (1.9 mmol g−1 at 0.4 bar CO2, i.e. the partial pressure of CO2 in biogas).

Binder‐free Zeolite Beta Beads with Hierarchical Porosity: Synthesis and Application as Heterogeneous Catalysts for Anisole Acylation

AbstractThree zeolites (H‐Beta, H‐ZSM‐5 and H‐Y) were synthesized in the form of binder‐free macroscopic beads (d=215–840 μm) using a hydrothermal method employing anion‐exchange resin beads as hard template. The beads obtained after removal of the hard template by calcination consisted of crystalline zeolite domains connected with each other to form a hierarchical porous network in which the zeolitic micropores are accessible through meso‐ and macropores, as proven by characterization with XRD, N2 physisorption, SEM, and TEM. The composition, the nature and amount of acid sites and the degree of hydrophobicity of these beads were investigated by means of XRF, solid‐state NMR, pyridine‐FTIR and TGA. The zeolite beads were tested as heterogeneous catalysts in the Friedel‐Crafts acylation of anisole with acetic anhydride to produce para‐methoxyacetophenone. H‐Beta‐Beads displayed the best catalytic performance with 95 % conversion of acetic anhydride and 76 % yield of para‐methoxyacetophenone in a batch reactor test (90 °C, 6 h). Next, the catalytic performance of H‐Beta‐Beads was compared in both batch and continuous‐flow mode to extrudates prepared by mixing zeolite Beta powder with either kaolin or bentonite binders. H‐Beta‐Beads outperformed the extrudates in batch‐mode reactions and could be reused in multiple runs without discernible loss of activity. In the continuous‐flow test, H‐Beta‐Beads demonstrated higher average activity but deactivated more rapidly than the extrudates.

Effect of Adding Conditions of Polyvinyl Alcohol on the Reaction Behavior and Particle Characteristics of Spherical Phenol‐formaldehyde Resin Beads

AbstractPhenol‐formaldehyde resin (PF) is the oldest synthetic resin. Through the design of synthesis conditions, PF resins with different characteristics can be provided, which are widely used in molding materials, adhesives and impregnation. Spherical PF beads are a hardened resin prepared by a special synthesis method. In this study, a mixture of phenol and formaldehyde was added with triethylamine, polyvinyl alcohol (PVA), and hexamethylenetetramine as a catalyst, granulating agent, and hardening agent, respectively. Spherical PF beads were prepared by a three‐stage suspension polymerization in a large‐scale water system, and the effects of PVA addition conditions on the reaction behavior and particle characteristics were discussed. The results show that formalin with a concentration of 14 % can be used as a formaldehyde raw material to prepare spherical PF beads by suspension polymerization. The largest spherical PF beads can be obtained with a reactant‐liquid ratio of 2/1, a stirring speed of 300 rpm, and an addition amount of BF‐04 of 2 %. The particle size of 14–20 mesh accounts for 83.9 % and has the average particle size of 1016 μm.

Coexistence of oscillatory and reduced states on a spherical field controlled by electrical potential.

The Belousov-Zhabotinsky (BZ) reaction was investigated to elucidate features of oscillations depending on the applied electrical potential, E. A cation-exchange resin bead loaded with the catalyst of the BZ reaction was placed on a platinum plate as a working electrode and then E was applied. We found that global oscillations (GO) and a reduced state coexisted on the bead at a negative value of E and that the source point of GO changed depending on E. The thickness of the reduced state was determined by a yellow colored region which corresponded to the distribution of Br2. The present studies suggest that the distribution of the inhibitor, Br-, which is produced from Br2, plays an important role in the existence of the reduced state and GO, and the source point of GO.

Efficient Production of Broad-Spectrum Antimicrobials by Paenibacillus polymyxa OSY-EC Using Acid Whey-Based Medium and Novel Antimicrobial Concentration Approach.

Production of some antimicrobial peptides by bacterial producers is a resource-intensive process, thus, using inexpensive growth media and simplifying antimicrobial extraction and down-stream processing are highly desirable. Acid whey, a dairy industry waste, is explored as a medium for production of broad–spectrum antimicrobials from selected bacteriocinogenic bacteria. Neutralized and yeast extract-supplemented acid whey was suitable for production of antimicrobials by four tested strains, but Paenibacillus polymyxa OSY–EC was the most prolific antimicrobial producer. Concentrating synthesized antimicrobials during culture incubation using beads of polymeric adsorbent resin, followed by solvent extraction and freeze-drying, resulted in antimicrobials-rich powder (AMRP). Under these conditions, P. polymyxa OSY–EC produced paenibacillin, polymyxin E, and fusaricidin, which are active against Gram-positive and Gram-negative bacteria and fungi, respectively. When media containing 2x and 4x minimum inhibitory concentrations of AMRP were inoculated with Listeria innocua and Escherichia coli, microbial populations decreased by ≥4–log CFU ml−1 in tryptic soy broth and ≥3.5–log CFU ml−1 in milk. The antimicrobial mechanism of action of AMRP solutions was attributed to the disruption of cytoplasmic membrane of indicator strains, L. innocua and E. coli. These findings exemplify promising strategies for valorization of acid whey via microbial bioreactions to yield potent antimicrobials.

Effective conductivity of random composites with shape-distributed near-spherical inclusions

While traditional and widely accepted mixing rules are based on the concept of a fixed inclusion shape, real particle composites are usually shape-distributed. For such composite materials, however, the analytical homogenization techniques are not well developed, while their numerical analysis becomes particularly complicated. We introduce and analyze two analytical models for the effective conductivity of a particular class of two-phase composites, namely those containing shape-distributed rigid inclusions. The models are derived with the use of the Bergman–Milton spectral density function approach. As we show, one of them, which involves the Gauss hypergeometric function, provides reasonable agreement with experimental data within the wide range of filling factors for ion-exchange resin beads in aqueous solutions. Another model, which is based on the uniform spectral density function, gives rise to a logarithmic singularity for the effective conductivity at the percolation threshold.

Multivariate curve resolution for analysis of Raman hyperspectral imaging data sets for enzyme immobilization

• Raman hyperspectral imaging of an enzyme immobilized onto two resins was accomplished. • Multivariate data analysis spectrally resolved chemical species involved in immobilization. • Chemical images spatially resolved chemical species involved in immobilization. • The Raman hyperspectral imaging data sets can be used for alternative applications. Biocatalytic processes are an essential component in achieving efficient and productive chemical syntheses in the scientific and industrial communities. Immobilization of the biocatalyst offers distinct advantages for the process, including increasing the stability and reusability of the biocatalyst as well as increasing control over the process. Herein, directly engineered pantothenate kinase (PanK) was immobilized to two commercially available microporous resins. Ralbovsky et al. (2021) utilized Raman hyperspectral imaging in combination with multivariate curve resolution alternating least squares (MCR-ALS) to spatially and spectrally resolve the chemical species involved in the enzyme immobilization process. Here, we provide eight Raman hyperspectral imaging data sets collected from the enzyme immobilized to the resin beads under different collection parameters, encompassing over 26,000 raw spectra. A brief discussion of the results, in the form of chemical maps and chemical images, indicates both resins, PanK, the glass substrate, and a Bis-Tris wash solution were resolved using MCR-ALS analysis of a subset of hyperspectral images, thus providing crucial chemical and spatial information about the system. The eight total Raman hyperspectral imaging data sets are shared to provide the scientific community with a thoroughly characterized set of spectral data which can be used for a variety of applications, including for further understanding and optimization of enzyme immobilization systems as well as for individual learning and development applications in the fields of chemical imaging and chemometrics.

In situ solid-liquid extraction enhances recovery of taxadiene from engineered Saccharomyces cerevisiae cell factories

Microbial cell factories express diverse heterologous pathways for the production of a wide range of valuable natural products. However, the recovery and purification of such compounds is a major bottleneck in commercialization. In this study, a novel in situ solid phase adsorption strategy was investigated for enhanced recovery of taxadiene, a precursor to the blockbuster anticancer drug, paclitaxel, from engineered Saccharomyces cerevisiae. A synthetic adsorbent resin (HP-20) was employed to efficiently sequester taxadiene as it was secreted during growth and a carefully optimized desorption solvent was applied following cultivation to maximize recovery of both secreted and intracellular taxadiene, across a range of scales (2 – 250 mL). Resin concentration was found to have an impact on cellular growth, with the high concentration of 12 % (w/v) resulting in fragmentation of the resin beads, which was detrimental to growth. The optimal resin concentration and desorption solvent combination elucidated at microscale (2 mL) resulted in a two-fold improvement in taxadiene titer to 61 ± 8 mg/L, compared to the traditional liquid-liquid extraction approach (dodecane overlay). Taxadiene was found to be distributed evenly between resin beads and biomass. Performance of the optimal process was subsequently investigated through scale-up using controlled mini-bioreactors (250 mL). Here, a comparable taxadiene titer of 76 ± 19 mg/L was achieved despite a 125-fold scale-up in cultivation volume. This represented a 1.4-fold improvement in taxadiene recovery compared to previous mini-bioreactor scale cultivations using the dodecane overlay extraction approach.

Separation anion and cation exchange resins using fluidization and adjusted NaOH solution density methods

The separation of anion and cation exchange resins has two advantages: (1) simplifying further treatment such as wet oxidation process, and (2) reducing further shielding, storage and disposal costs of radioactive wastes. In this paper two methods including the resin bead fluidization with fluid in a column and immersion into a solution with proper density to separate the resins were investigated. When the up-flowrate was operated between 40 and 80 cm/min, approximately 80% of anion exchange resin was retrieved and the immersion method using a 16–20 wt% of NaOH solution resulted in the anion and cation exchange resins being easily separated although with the most of Cs and partial of Co and Sr ions/radionuclides on the resins exchanged by Na from the solution. After separation the anion exchange resin from radioactive spent resins retrieved from the decommissioning activities in Taiwan Research Reactor, the volume of radioactive wastes with higher radiation and long half-life radionuclides could be reduced.

Silver-containing Cation Exchange Resin: Synthesis and Application

Cation exchange resins are widely used for water softening and demineralization all over the world. Deposition, metabolism, and growth of bacteria and fungi on the resin beads cause capacity and performance losses, especially during repeated use in cyclic and long-term operations. Over the last decades, modification of different materials by silver nanoparticles (AgNPs) has demonstrated to present significant opportunities in mitigating biofouling problems. The paper deals with a novel facile technique of introducing silver colloids (AgC) into cation exchange resin, providing the formation of silver micro- and nano-inclusions on the cation resin beads. The scanning electron microscope (SEM) measurements have confirmed a spherical shape and uniform distribution of AgC (50 – 1000 nm) on the surface of the resin. To evaluate the antibacterial and fungicidal properties of AgC on the cation resin beads, we have used Aureobasidium sp., Penicillium sp., and Staphylococcus aureus cultures. AgC coating has proved to efficiently prevent bacteria/biofilm growth on the cation resin beads and thereby significantly increase the service life of the cation exchange resin, especially in hot climatic conditions. Possible antibiofouling mechanisms of the modified nanocomposite cationite have been discussed. Since 2020, the modified silver-containing cationite has been successfully utilized for water softening systems of boiler equipment in Uzbekistan, demonstrating the suitability of the suggested facile coating technique for reducing fouling of cation-exchange resin.

Efficient Route for the Preparation of Composite Resin Incorporating Silver Nanoparticles with Enhanced Antibacterial Properties.

An efficient and facile route for the immobilization of silver (Ag) nanoparticles (NPs) in anion exchange resin beads with different silver loading is proposed. In this method, BH4− ions were first introduced into chloride-form resin through an ion exchange process with Cl− ions, followed by in-situ chemical reduction of Ag+ ions at the surface of the resin to form metallic Ag nanoparticles. Morphology and structure of the resulting Ag-resin nanocomposites were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), Fourier transform infra-red (FTIR), inductively coupled plasma-optical emission spectrometry (ICP-OES), and thermogravimetry analysis (TGA). The results confirmed the presence of smaller diameter Ag NPs incorporated into the resin beads having an average diameter on the order of 10 nm with a few Ag NP clusters of 20–100 nm. The nanoparticles were homogeneously distributed throughout the resin. There were no dramatic increases in average particle sizes even at very high Ag loadings. The resin retained its structure and stability, allowing higher stability of immobilized AgNPs than the colloidal ones. The Ag-loaded resins made with 50 mM AgNO3 were tested for antibacterial activity in vitro against Escherichia coli (E. coli) as a model microbial contaminant in water. Results showed greater than 99% bacterial inhibition within 3 h of exposure. The resin form offers greater ease of handling, long-term storage at room temperature, reusability in repeated reactions, and reduces the risk of environmental contamination.

Development of neutron-activated samarium-153-loaded polystyrene microspheres as a potential theranostic agent for hepatic radioembolization.

Hepatic radioembolization is an effective minimally invasive treatment for primary and metastatic liver cancers. Yttrium-90 [90Y]-labelled resin or glass beads are typically used as the radioembolic agent for this treatment; however, these are not readily available in many countries. In this study, novel samarium-153 oxide-loaded polystyrene ([153Sm]Sm2O3-PS) microspheres were developed as a potential alternative to 90Y microspheres for hepatic radioembolization. The [152Sm]Sm2O3-PS microspheres were synthesized using solid-in-oil-in-water solvent evaporation. The microspheres underwent neutron activation using a 1 MW open-pool research reactor to produce radioactive [153Sm]Sm2O3-PS microspheres via 152Sm(n,γ)153Sm reaction. Physicochemical characterization, gamma spectroscopy and in-vitro radionuclide retention efficiency were carried out to evaluate the properties and stability of the microspheres before and after neutron activation. The [153Sm]Sm2O3-PS microspheres achieved specific activity of 5.04 ± 0.52 GBq·g-1 after a 6 h neutron activation. Scanning electron microscopy and particle size analysis showed that the microspheres remained spherical with an average diameter of ~33 μm before and after neutron activation. No long half-life radionuclide and elemental impurities were found in the samples. The radionuclide retention efficiencies of the [153Sm]Sm2O3-PS microspheres at 550 h were 99.64 ± 0.07 and 98.76 ± 1.10% when tested in saline solution and human blood plasma, respectively. A neutron-activated [153Sm]Sm2O3-PS microsphere formulation was successfully developed for potential application as a theranostic agent for liver radioembolization. The microspheres achieved suitable physical properties for radioembolization and demonstrated high radionuclide retention efficiency in saline solution and human blood plasma.

Lanthanum carbonate nanoparticles confined within anion exchange resin for phosphate removal from river water: Batch and fixed-bed column study

The use of lanthanum for phosphate removal has gained increasing attention due to its relative abundance, non-toxicity, and strong affinity toward phosphate. In this regard, although lanthanum hydroxide exhibits promising phosphate removal ability, its practical application remains limited due to certain technical issues including its structural instability and leaching. To circumvent these issues, a lanthanum carbonate-based adsorbent was developed in this study. Lanthanum carbonate@anion exchange resin (LC@AER) and lanthanum hydroxide@anion exchange resin (LH@AER) beads were first prepared through in-situ precipitation using identical bead-to-precursor mass ratios. LC@AER beads were chosen for further study as they displayed better adsorption capacity and stability, and the bead-to-precursor mass ratio was further optimized to improve performance and stability. LC@AER (1:2) beads exhibited a maximum adsorption capacity of 77.43 mg-P/g and excellent selectivity toward phosphate in the presence of various co-existing anions. Experiments using river water indicated high phosphate removal efficiency, demonstrating potential for treating river water. Investigations revealed key differences in phosphate binding mechanisms for batch and column experiments. In batch setting, phosphate is primarily captured through ligand exchange and inner-sphere complexation. However, over prolonged column operation, surface precipitation and electrostatic attraction (between phosphate and quaternary ammonium) become increasingly important for binding phosphate, which may affect phosphate recovery efficiency and must be accounted for in process design. Overall, the findings indicate that lanthanum carbonate serves as a good alternative to lanthanum hydroxide and that LC@AER (1:2) beads are promising for phosphate removal.

Combined Effects of Copper Oxide and Nickel Oxide Coated Chitosan Nanoparticles Adsorbed to Styrofoam Resin Beads on Hydrothermal Vent Bacteria

Combined Effects of Copper Oxide and Nickel Oxide Coated Chitosan Nanoparticles Adsorbed to Styrofoam Resin Beads on Hydrothermal Vent Bacteria

Application of Affitins for Affinity Purification of Proteins.

Affinity chromatography is a powerful purification technique, as it allows proteins of interest to be obtained at a high degree of purity in a single step. This technique can be applied on a research laboratory scale as well as on an industrial scale. The interaction involved in affinity separation most often involves a natural ligand or an antibody specific for the protein of interest, or the recognition of a peptide tag artificially added to the recombinant protein. Unfortunately, natural ligands are not always available and it may be undesirable or impossible to add a purification tag, especially for the production of therapeutic proteins. We have developed Affitins as a new class of artificial affinity proteins that can be generated against virtually any protein of interest. Due to their very high selectivity, their remarkable robustness against extreme acid or alkaline conditions and their low production cost, Affitins are particularly suited to this technique. We describe here the production of Affitins and their immobilization on resin beads to prepare affinity chromatography columns. The protocol also describes the use of these columns.

Characterizing extracellular vesicles from cerebrospinal fluid by a novel size exclusion chromatography method

AbstractBackgroundExtracellular vesicles (EVs) have recently been considered as a potential biomarker source for a variety of diseases, including neurodegenerative disorders. EVs are important mediators of intercellular communication due to their capacity to transfer genetic material, lipids and proteins. By means of their communication role, interesting biomarkers are often enriched in EVs compared to total biofluid. In order to isolate EVs from a biofluid, like cerebrospinal fluid (CSF), a variety of isolation methods are available of which each methods shows different results, and, to date, there is no golden standard. Our study evaluates the use of size exclusion chromatography (SEC) by the SmartSEC HT kit for EV isolation from CSF.MethodEVs were obtained from 500µL CSF samples, isolated by SmartSEC HT. SmartSEC traps contaminants, like bulk proteins, into the resin beads and subsequently elutes EVs. To evaluate this isolation method, various characterisation analyses were run. To detect cargo or surface proteïns, analyses on the ExoView R100, Surface Plasmon Resonance imaging (SPRi) and LC‐MS based proteomics analysis were performed. Concentration, and size of the vesicles were evaluated by use of transmission electron microscopy (TEM), and fluorescence nanotracking analysis (Zetaview).ResultBy means of the ExoView, tetraspanins such as CD81 and CD9 were measured on the surface of the EVs. Other EV‐specific proteins, e.g. lactadherin, flotillin‐1, and HSP70, were detected by SPRI. Untargeted protein analysis revealed the cargo proteins. TEM images visualized the presence of EVs. Particle size and concentration was calculated by nanotracking analysis, and more specifically the particles with a lipid membrane, like EVs, with fluorescence nanotracking analysis.ConclusionAs EVs hold a lot of promise in the biomarker field, a standard high‐performance isolation method ‐ regarding purity and yield – is essential. From our data, SmartSEC HT is suggested to be an efficient size exclusion chromatography EV isolation method for low volume CSF samples, especially for high throughput, since samples are loaded on a 96‐well plate.

Immobilization and Characterization of Pectinase onto the Cationic Polystyrene Resin.

In the present study, the immobilization of free pectinase onto polystyrene resin beads via crosslinking with glutaraldehyde was investigated. The immobilized pectinase was characterized by Fourier transform infrared spectroscopy and confocal laser scanning microscopy. After optimizing the immobilization conditions, the optimum pH of immobilized pectinase shifted from 8.0 to 8.5 and the optimum temperature shifted from 45 to 60 °C, showing its improved stability to temperature and pH compared with the free pectinase. The Michaelis–Menten constant Km value of free and immobilized pectinase was determined to be 1.95 and 5.36 mM, respectively. The storage stability of immobilized pectinase was demonstrated with 36.8% of the initial activity preserved after 30 days at 25 °C. The reusability of the immobilized pectinase activity was 54.6% of its initial activity after being recycled six times. Therefore, based on the findings mentioned above, it can be inferred that this simple immobilization technique for pectinase appears to be promising for industrial applications.