Immobilization of pectin depolymerising polygalacturonase using different polymers

Impact of immobilized pectinase-alginate beads on physicochemical properties, antioxidant activity, and reusability in papaya juice processing

Papaya fruit, which has a medium level of pectin content, faces critical challenges in the production of papaya juice, leading to an undesirable, highly viscous texture. Conventional reliance on the use of free pectinase enzymes has addressed this issue; however, their single-use nature has limited their efficiency and has subsequently brought about an increase in processing costs. Hence, immobilized pectinase-alginate (IPA) beads with calcium chloride were developed, and the effects of their reusability on the physicochemical and antioxidant characteristics of papaya juice were analyzed. Immobilization of pectinase enzyme with sodium alginate (2%-4%) and calcium chloride (0.1-0.3 M) resulted in an immobilization yield ranging from 93.06% to 95.82%. It was found that the IPA beads maintained more than 80% relative activity even after seven subsequent cycles while demonstrating storage stability with more than 88% residual activity for up to 35 days, proving their efficiency and sustainability. In the first cycle, treatment with IPA beads significantly reduced the pectin content (51.61 mg GalAE/100 mL) and viscosity (1.15 mPa.s) of papaya juice compared to the control, which exhibited higher values of 235.00 mg GalAE/100 mL and 2.46 mPa.s, respectively. Both immobilized and free enzymes exhibit comparable results, outperforming the control, but IPA benefits by improving process efficiency through enzyme reusability. In addition, IPA could significantly maintain papaya juice's antioxidant activity over four treatment cycles. Future research is needed to focus on industrial scaling, shelf life of the IPA beads, and consumer acceptance of the papaya juice treated with immobilized enzyme. PRACTICAL APPLICATION: Papaya juice processing is challenging due to its moderate pectin content, which contributes to high viscosity, reduced yield, and increased turbidity, affecting overall juice quality. The conventional application of free pectinase in juice processing introduces further complications related to enzyme stability, cost, and recovery for reuse. Immobilizing pectinase minimizes waste via enzyme reuse, decreases juice viscosity, enhances clarity, and maintains antioxidant properties, thereby promoting process sustainability and meeting consumer preferences. The technology can be scaled and applied to a wide range of fruit juice processing industries, improving efficiency and nutritional value.

Hyperactivation of lipases by immobilization on superhydrophobic graphene quantum dots inorganic hybrid nanoflower

Various nanoflowers are synthesized for enzyme immobilization. In order to increase the activity of nanoflowers, in this study, 3D flower-like structured organic-inorganic hybrid nanoflowers (hNFs) with various lipases Rhizomucor miehei lipase (RML), Candida antarctica lipase B (CALB), Humicola insolens lipase (HIL), Thermomyces lanuginosus lipase (TLL), Eversa® Transform 2.0 (ET) a genetically modified enzyme derived of TLL and graphene quantum dots (GQDs) were prepared and characterized.Lipase hNFs [lipase-(Cu/Co)3(PO4)2] and lipase@GQDs hNFs [lipase@GQDs-(Cu/Co)3(PO4)2] were straightforwardly prepared through mixing with metal ion (Cu2+or Co2+) aqueous solutions with or without GQDs. The ET@GQDs-(Cu)3(PO4)2 hNFs demonstrated 687 % higher activity than ET-(Cu)3(PO4)2 hNFs and 650 % higher activity than the free ET. Similar results were also observed with other lipase hybrid nanoflowers. For example, TLL@GQDs-(Cu)3(PO4)2 hNFs exhibited a 557 % higher activity than TLL-(Cu)3(PO4)2 hNFs and a 463 % higher activity than free TLL. Additionally, TLL@GQDs-(Co)3(PO4)2 hNFs showed a 141 % higher activity than TLL-(Co)3(PO4)2 hNFs and a 304 % higher activity than free TLL. Upon examining pH and thermal stability, it was revealed that lipase@GQDs hNFs exhibited higher activity compared to free lipase and other hNFs without GQDs. The effect of metal ions, enzyme concentrations and amount of GQDs on the morphology and enzyme activity of the lipase-hNFs was examined.

Enhanced Enzymatic Performance of β-Mannanase Immobilized on Calcium Alginate Beads for the Generation of Mannan Oligosaccharides

Mannan oligosaccharides (MOSs) are excellent prebiotics that are usually obtained via the enzymatic hydrolysis of mannan. In order to reduce the cost of preparing MOSs, immobilized enzymes that demonstrate good performance, require simple preparation, and are safe, inexpensive, and reusable must be developed urgently. In this study, β-mannanase was immobilized on calcium alginate (CaAlg). Under the optimal conditions of 320 U enzyme addition, 1.6% sodium alginate, 2% CaCl2, and 1 h of immobilization time, the immobilization yield reached 68.3%. The optimum temperature and pH for the immobilized β-mannanase (Man-CaAlg) were 75 °C and 6.0, respectively. The Man-CaAlg exhibited better thermal stability, a high degree of pH stability, and less substrate affinity than free β-mannanase. The Man-CaAlg could be reused eight times and retained 70.34% of its activity; additionally, the Man-CaAlg showed 58.17% activity after 30 days of storage. A total of 7.94 mg/mL of MOSs, with 4.94 mg/mL of mannobiose and 3.00 mg/mL of mannotriose, were generated in the oligosaccharide production assay. It is believed that this convenient and safe strategy has great potential in the important field of the use of immobilized β-mannanase for the production of mannan oligosaccharides.

Optimization of Cultural Conditions for Pectinase Production by Streptomyces sp. and Characterization of Partially Purified Enzymes

The cultural parameters of Streptomyces sp. for pectinase production were optimized using the Box-Behnken design. The maximum pectinase production was obtained after 58 h at 35°C and pH 7 upon submerged fermentation in yeast extract-containing media. The enzymes were partially purified with acetone precipitation, and the analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and zymogram revealed that Streptomyces sp. produced two pectinases protein with molecular weights of about 25 and 75 kDa. The pectinase activity was detected in a wide range of temperatures (30°C-80°C) and pH (3-9) with maximum pectinase activities observed at 70°C and pH 5 and 9. The enzymes retained about 30-40% of their activities even after incubating the enzyme at different temperatures for 120 min. The pectinase activities of Streptomyces sp. were enhanced in the media containing 1.5% pectin, 1% casein as a nitrogen source, 0.5 mM MgSO4, and 5 mM NaCl. Further, the addition of Tween-20, amino acids, and vitamins to the media also enhanced the pectinase activity. Moreover, the bacterium illustrated the ability to decolorize crystal violet dye efficiently. The decolorization rate ranged from 39.29 to 53.75%, showing the highest bacterial decolorization in the media containing 2 mg/mL crystal violet at 144 h. Therefore, the bacterium has the potential in treating wastewater produced by industries like textile industries.

Polymer/Enzyme Composite Materials—Versatile Catalysts with Multiple Applications

A significant interest was granted lately to enzymes, which are versatile catalysts characterized by natural origin, with high specificity and selectivity for particular substrates. Additionally, some enzymes are involved in the production of high-valuable products, such as antibiotics, while others are known for their ability to transform emerging contaminates, such as dyes and pesticides, to simpler molecules with a lower environmental impact. Nevertheless, the use of enzymes in industrial applications is limited by their reduced stability in extreme conditions and by their difficult recovery and reusability. Rationally, enzyme immobilization on organic or inorganic matrices proved to be one of the most successful innovative approaches to increase the stability of enzymatic catalysts. By the immobilization of enzymes on support materials, composite biocatalysts are obtained that pose an improved stability, preserving the enzymatic activity and some of the support material’s properties. Of high interest are the polymer/enzyme composites, which are obtained by the chemical or physical attachment of enzymes on polymer matrices. This review highlights some of the latest findings in the field of polymer/enzyme composites, classified according to the morphology of the resulting materials, following their most important applications.

Covalent Immobilization of Chondrostereum purpureum Endopolygalacturonase on Ferromagnetic Nanoparticles: Catalytic Properties and Biotechnological Application

Pectinases are widely used in a variety of industrial processes. However, their application is limited by low catalytic processivity, reduced stability, high cost, and poor re-use compatibility. These drawbacks may be overcome by enzyme immobilization with ferromagnetic nanoparticles, which are easily recovered by a magnetic field. In this work, an endopolygalacturonase from Chondrostereum purpureum (EndoPGCp) expressed in Pichia pastoris was immobilized on glutaraldehyde-activated chitosan ferromagnetic nanoparticles (EndoPGCp-MNP) and used to supplement a commercial enzyme cocktail. No significant differences in biochemical and kinetic properties were observed between EndoPGCp-MNP and EndoPGCp, although the EndoPGCp-MNP showed slightly increased thermostability. Cocktail supplementation with EndoPGCp-MNP increased reducing sugar release from orange wastes by 1.8-fold and showed a synergistic effect as compared to the free enzyme. Furthermore, EndoPGCp-MNP retained 65% of the initial activity after 7 cycles of re-use. These properties suggest that EndoPGCp-MNP may find applications in the processing of pectin-rich agroindustrial residues.

New insights in pectinase production development and industrial applications

Pectinase, a group of pectin degrading enzymes, is one of the most influential industrial enzymes, helpful in producing a wide variety of products with good qualities. These enzymes are biocatalysts and are highly specific, non-toxic, sustainable, and eco-friendly. Consequently, both pectin and pectinase are crucially essential biomolecules with extensive applicatory perception in the biotechnological sector. The market demand and application of pectinases in new sectors are continuously increasing. However, due to the high cost of the substrate used for the growth of microbes, the production of pectinase using microorganisms is limited. Therefore, low-cost or no-cost substrates, such as various agricultural biomasses, are emphasized in producing pectinases. The importance and implications of pectinases are rising in diverse areas, including bioethanol production, extraction of DNA, and protoplast isolation from a plant. Therefore, this review briefly describes the structure of pectin, types and source of pectinases, substrates and strategies used for pectinases production, and emphasizes diverse potential applications of pectinases. The review also has included a list of pectinases producing microbes and alternative substrates for commercial production of pectinase applicable in pectinase-based industrial technology.Key points• Pectinase applications are continuously expanding.• Organic wastes can be used as low-cost sources of pectin.• Utilization of wastes helps to reduce pollution.

Nano-organic supports for enzyme immobilization: Scopes and perspectives

A variety of organic nanomaterials and organic polymers are used for enzyme immobilization to increase enzymes stability and reusability. In this study, the effects of the immobilization of enzymes on organic and organic-inorganic hybrid nano-supports are compared. Immobilization of enzymes on organic support nanomaterials was reported to significantly improve thermal, pH and storage stability, acting also as a protection against metal ions inhibitory effects. In particular, the effects of enzyme immobilization on reusability, physical, kinetic and thermodynamic parameters were considered. Due to their biocompatibility with low health risks, organic support nanomaterials represent a good choice for the immobilization of enzymes. Organic nanomaterials, and especially organic-inorganic hybrids, can significantly improve the kinetic and thermodynamic parameters of immobilized enzymes compared to macroscopic supports. Moreover, organic nanomaterials are more environment friendly for medical applications, such as prodrug carriers and biosensors. Overall, organic hybrid nanomaterials are receiving increasing attention as novel nano-supports for enzyme immobilization and will be used extensively.

Biopolymers and nanostructured materials to develop pectinases-based immobilized nano-biocatalytic systems for biotechnological applications

Pectinases are the emerging enzymes of the biotechnology industry with a 25% share in the worldwide food and beverage enzyme market. These are green and eco-friendly tools of nature and hold a prominent place among the commercially produced enzymes. Pectinases exhibit applications in various industrial bioprocesses, such as clarification of fruit juices and wine, degumming, and retting of plant fibers, extraction of antioxidants and oil, fermentation of tea/coffee, wastewater remediation, modification of pectin-laden agro-industrial waste materials for high-value products biosynthesis, manufacture of cellulose fibres, scouring, bleaching, and size reduction of fabric, cellulosic biomass pretreatment for bioethanol production, etc. Nevertheless, like other enzymes, pectinases also face the challenges of low operational stability, recoverability, and recyclability. To address the above-mentioned problems, enzyme immobilization has become an eminently promising approach to improve their thermal stability and catalytic characteristics. Immobilization facilitates easy recovery and recycling of the biocatalysts multiple times, leading to enhanced performance and commercial feasibility.In this review, we illustrate recent developments on the immobilization of pectinolytic enzymes using polymers and nanostructured materials-based carrier supports to constitute novel biocatalytic systems for industrial exploitability. The first section reviewed the immobilization of pectinases on polymers-based supports (ca-alginate, chitosan, agar-agar, hybrid polymers) as a host matrix to construct robust pectinases-based biocatalytic systems. The second half covers nanostructured supports (nano-silica, magnetic nanostructures, hybrid nanoflowers, dual-responsive polymeric nanocarriers, montmorillonite clay), and cross-linked enzyme aggregates for enzyme immobilization. The biotechnological applications of the resulted immobilized robust pectinases-based biocatalytic systems are also meticulously vetted. Finally, the concluding remarks and future recommendations are also given.

Single step immobilization of CMCase within agarose gel matrix: Kinetics and thermodynamic studies

In the current study, CMCase from Bacillus licheniformis KIBGE-IB2 was immobilized within the matrix of agarose gel through entrapment technique. Maximum immobilization yield (%) of the enzyme was obtained when 2.0 % agarose was used. The activation energy (E_a) of the enzyme increased from 16.38 to 44.08 kJ mol^-1 after immobilization. Thermodynamic parameters such as activation energy of deactivation (ΔG_d), enthalpy (ΔH_d) and entropy (ΔS_d) of deactivation, deactivation rate constant (K_d), half-life (t_1/2), D-value and z-value were calculated for native/free and immobilized CMCase. The maximum reaction rate (V_max) of the native enzyme was found to be 8319.47 U ml^-1 min^-1, which reduced to 7218.1 U ml^-1 min^-1after immobilization process. However, the Michaelis-Menten constant (K_m) value of the enzyme increased from 1.236 to 2.769 mg ml^-1 min^-1 after immobilization. Immobilized enzyme within agarose gel matrix support can be reuse up to eight reaction cycles. Broad stability profile and improved catalytic properties of the immobilized CMCase indicated that this enzyme can be a plausible candidate to be used in various industrial processes.

Utilization of different polymers for the improvement of catalytic properties and recycling efficiency of bacterial maltase

Current study deals with the comparative study related to immobilization of maltase using synthetic (polyacrylamide) and non-synthetic (calcium alginate, agar-agar and agarose) polymers via entrapment technique. Polyacrylamide beads were formed by cross-linking of monomers, agar-agar and agarose through solidification while alginate beads were prepared by simple gelation. Results showed that the efficiency of enzyme significantly improved after immobilization and among all tested supports agar-agar was found to be the most promising and biocompatible for maltase in terms of immobilization yield (82.77%). The catalytic behavior of maltase was slightly shifted in terms of reaction time (free enzyme, agarose and polyacrylamide: 5.0 min; agar-agar and alginate: 10.0 min), pH (free enzyme, alginate and polyacrylamide: 6.5; agar-agar, agarose: 7.0) and temperature (free enzyme: 45 °C; alginate: 50 °C; polyacrylamide: 55 °C; agarose: 60 °C; agar-agar: 65 °C). Stability profile of immobilized maltase also revealed that all the supports utilized have significantly enhanced the activity of maltase at higher temperatures then its free counterpart. However, recycling data showed that agar-agar entrapped maltase retained 20.0% of its initial activity even after 10 cycles followed by agarose (10.0%) while polyacrylamide and alginate showed no activity after 8 and 6 cycles respectively.

A comprehensive review on incredible renewable carriers as promising platforms for enzyme immobilization & thereof strategies

Enzymes are the highly versatile bio-catalysts having the potential for being employed in biotechnological and industrial sectors to catalyze biosynthetic reactions over a commercial point of view. Immobilization of enzymes has improved catalytic properties, retention activities, thermal and storage stabilities as well as reusabilities of enzymes in synthetic environments that have enthralled significant attention over the past few years. Dreadful efforts have been emphasized on the renewable and synthetic supports/composite materials to reserve their inherent characteristics such as biocompatibility, non-toxicity, accessibility of numerous reactive sites for profitable immobilization of biological molecules that often serve diverse applications in the pharmaceutical, environmental, and energy sectors. Supports should be endowed with unique physicochemical properties including high specific surface area, hydrophobicity, hydrophilicity, enantioselectivities, multivalent functionalization which professed them as competent carriers for enzyme immobilization. Organic, inorganic, and nano-based platforms are more potent, stable, highly recovered even after used for continuous catalytic processes, broadly renders the enzymes to get efficiently immobilized to develop an inherent bio-catalytic system that displays higher activities as compared to free-counter parts. This review highlights the recent advances or developments on renewable and synthetic matrices that are utilized for the immobilization of enzymes to deliver emerging applications around the globe.

Biocatalysis in the winemaking industry: Challenges and opportunities for immobilized enzymes

Enzymes are powerful catalysts already being used in a large number of industrial processes. Impressive advantages in enzyme catalysts improvement have occurred in recent years aiming to improve their performance under harsh operation conditions far away from those of their cellular habitat. Production levels of the winemaking industry have experienced a remarkable increase, and technological innovations have been introduced for increasing the efficiency at different process steps or for improving wine quality, which is a key issue in this industry. Enzymes, such as pectinases and proteases, have been traditionally used, and others, such as glycosidases, have been more recently introduced in the modern wine industry, and many dedicated studies refer to the improvement of enzyme performance under winemaking conditions. Within this framework, a thorough review on the role of enzymes in winemaking is presented, with special emphasis on the use of immobilized enzymes as a significant strategy for catalyst improvement within an industry in which enzymes play important roles that are to be reinforced paralleling innovation.

Construction of magnetic nanoflower biocatalytic system with enhanced enzymatic performance by biomineralization and its application for bisphenol A removal

This study first reported a magnetic nanoflower biocatalyst of the core-shell magnetic composite microspheres with a hierarchical flower-like surface structure, which was consist of the organic component (horseradish peroxidase, HRP) and the inorganic component (Fe₃O₄@PMG-IDA-Cu²⁺) through self-assembly in the phosphate buffered saline (PBS) solution. The structure, pattern and crystallization of the magnetic nanoflowers were confirmed through a series of characterization. The optimized results of the magnetic nanoflowers formation conditions demonstrated that their hierarchical structure could effectively enhance the enzyme activity. The magnetic nanoflowers exhibited enhanced durability, stability and reusability through the study of enzymatic properties. The magnetic nanoflowers were applied to remove the bisphenol A (BPA) from water and the removal efficiency reached about 92.1%, meanwhile the enzymatic activity of the magnetic nanoflowers was achieved 183% enhancement in comparison with free HRP. In addition, the magnetic nanoflowers showed outstanding reusability and reproducibility, which would have potential application in biocatalysis.

Naturally-derived biopolymers: Potential platforms for enzyme immobilization

Naturally-derived biopolymers such as alginate, chitosan, cellulose, agarose, guar gum/guaran, agar, carrageenan, gelatin, dextran, xanthan, and pectins, etc. have appealed significant attention over the past several years owing to their natural abundance and availability all over the years, around the globe. In addition, their versatile properties such as non-toxicity, biocompatibility, biodegradability, flexibility, renewability, and the availability of numerous reactive sites offer significant functionalities with multipurpose applications. At present, intensive research efforts have been focused on engineering enzymes using natural biopolymers as novel support/composite materials for diverse applications in biomedical, environmental, pharmaceutical, food and biofuel/energy sectors. Immobilization appears as a straightforward and promising approach to developing biocatalysts with improved catalytic properties as compared to their free counterparts. Biopolymers-assisted enzymes are more stable, robust, and recoverable than that of free forms, and can be employed for continuous biocatalytic reactions. The present review highlights the recent developments and use of biopolymers and their advanced composites as support carriers for the immobilization of a variety of different enzymes to develop biocatalysts with desired catalytic activity and stability characteristics for emerging applications.

Agarose-chitosan hydrogel-immobilized horseradish peroxidase with sustainable bio-catalytic and dye degradation properties

Herein, we developed and characterized robust agarose-chitosan hydrogel using N‑hydroxysuccinimide (NHS) as a mild chemical cross-linker. The hydrogel offered a simple, effective and eco-friendlier support material with >90% of immobilization efficiency of horseradish peroxidase. The surface morphology and functional properties of the agarose-chitosan hydrogel with and without immobilized horseradish peroxidase were investigated by scanning electron microscopy and Fourier-transform infrared, respectively. The agarose-chitosan hydrogel-immobilized horseradish peroxidase (ACH-HRP) exhibited wide-working pH and temperature stability, and promising reusability for its substrate oxidation. The ACH-HRP preserved a better activity under acidic environments, pH 4.0 (38 vs. 5.9%), and well stabilized under alkaline conditions, retaining a 3.9-folds greater activity than a free counterpart at pH 10. With reference to a free enzyme, 1.6- and 4-fold greater catalytic activity was achieved at 50 and 70 °C, respectively, by the immobilized HRP. Further, the hydrogel displayed insignificant loss in enzyme functionality sustaining above 90% and 60% of original activity after 5 and 10 continuous cycles of use. HPLC profile corroborated the enzyme-assisted Reactive Blue 19 (RB-19) degradation, whereas UPLC/MS analysis scrutinized the dye degradation intermediates and a tentative mechanistic degradation pathway was proposed. In conclusion, the results demonstrate that ACH-HRP is a promising option for use as industrial biocatalyst in diverse biotechnological applications.

Fabrication of FGF-2 immobilized electrospun gelatin nanofibers for tissue engineering

Conjugated gelatin nanofibers were fabricated by electrospinning, followed by a simple glutaraldehyde cross-linking procedure and avidin conjugation. Then, biotinylated growth factors were immobilized onto the surface of the fibers through avidin-biotin covalent binding. The immobilization of growth factors was confirmed through immunostaining using fluorescence microscopy and microplate spectrophotometry. Adipose derived stem cells (ASCs) were cultured to examine the effect of immobilized growth factors on cell proliferation using the cell counting Kit-8 (CCK-8) assay. Gelatin nanofibers with no growth factors attached and growth factors in suspension within media were used as controls. Growth factors were successfully immobilized onto the surface, in amounts corresponding to the concentrations applied, and increased cell proliferation to a higher extend than growth factors in suspension. Our results suggest that this controllable scaffolding strategy provides an effective system for growth factors delivery in tissues, suitable for engineering applications.