Aspartic acid introduce the functional amine groups on the surface of superparamagnetic Fe(OH)3@Fe3O4 nanoparticles for efficient immobilization of Penaeus vannamei protease

Aspergillus oryzae β-D-galactosidase immobilization on glutaraldehyde pre-activated amino-functionalized magnetic mesoporous silica: Performance, characteristics, and application in the preparation of sesaminol

Aspergillus oryzae β-D-galactosidase (β-Gal) efficiently hydrolyzes sesaminol triglucoside into sesaminol, which has higher biological activity. However, β-Gal is difficult to be separate from the reaction mixture and limited by stability. To resolve these problems, β-Gal was immobilized on amino-functionalized magnetic nanoparticles mesoporous silica pre-activated with glutaraldehyde (Fe3O4@mSiO2-β-Gal), which was used for the first time to prepare sesaminol. Under the optimal conditions, the immobilization yield and recovered activity of β-Gal were 57.9 ± 0.3 % and 46.5 ± 0.9 %, and the enzymatic loading was 843 ± 21 Uenzyme/gsupport. The construction of Fe3O4@mSiO2-β-Gal was confirmed by various characterization methods, and the results indicated it was suitable for heterogeneous enzyme-catalyzed reactions. Fe3O4@mSiO2-β-Gal was readily separable under magnetic action and displayed improved activity in extreme pH and temperature conditions. After 45 days of storage at 4 °C, the activity of Fe3O4@mSiO2-β-Gal remained at 92.3 ± 2.8 %, which was 1.29 times than that of free enzyme, and its activity remained above 85 % after 10 cycles. Fe3O4@mSiO2-β-Gal displayed higher affinity and catalytic efficiency. The half-life was 1.41 longer than free enzymes at 55.0 °C. Fe3O4@mSiO2-β-Gal was employed as a catalyst to prepare sesaminol, achieving a 96.7 % conversion yield of sesaminol. The excellent stability and catalytic efficiency provide broad benefits and potential for biocatalytic industry applications.

A newly synthesized magnetic nanoparticle coated with glycidyl methacrylate monomer and 1,2,4-Triazole: Immobilization of α-Amylase from Bacillus licheniformis for more reuse, stability, and activity in the presence of H2O2

α-Amylase is a secretory enzyme commonly found in nature. The α-Amylase enzyme catalyzes the hydrolysis of α-D-(1,4)-glucosidic bonds in starch, glycogen, and polysaccharides. The chemical characterization of the composite carrier and the immobilized enzyme was performed, and the accuracy of the immobilization was confirmed by FTIR, SEM, and EDS analyses. The X-ray diffraction (XRD) analysis indicates that the magnetic nanoparticle retained its magnetic properties following the modification process. Based on the Thermogravimetric Analysis (TGA) outcomes, it was evident that the structural integrity of the FPT nanocomposite remained unchanged at 200°C. The optimal pH was determined to be 5.5, and no alteration was observed following the immobilization process. Purified α-amylases usually lose their activity rapidly above 50°C. In this study, Bacillus licheniformis α-Amylase enzyme was covalently immobilized on the newly synthesized magnetic composite carrier having more azole functional group. For novelty-designed immobilized enzymes, while there is no change in the pH and optimum operating temperature of the enzyme with immobilization, two essential advantages are provided to reduce enzyme costs: the storage stability and reusability are increased. Furthermore, our immobilization technique enhanced enzyme stability when comparing our immobilized enzyme with the reference enzyme in industrial applications. The activity of the immobilized enzyme was higher in presence of 1-3% H2O2.

Functionalized activated carbon as support for trypsin immobilization and its application in casein hydrolysis

This study aimed to immobilize trypsin on activated carbon submitted to different surface modifications and its application in casein hydrolysis. With the aim of determining which support can promote better maintenance of the immobilized enzyme. Results showed that pH 5.0 was obtained as optimal for immobilization and pH 9.0 for the casein hydrolysis reaction for activated carbon and glutaraldehyde functionalized carbon. Among the supports used, activated carbon modified with iron ions in the presence of a chelating agent was the one that showed best results, under the conditions evaluated in this study. Presenting an immobilization yield of 95.15% and a hydrolytic activity of 4.11 U, same as soluble enzyme (3.76 U). This derivative kept its activity stable at temperatures above 40 °C for1 h and when stored for 30 days at 5 °C. Furthermore, it was effective for more than 6 reuse cycles (under the same conditions as the 1st cycle). In general, immobilization of trypsin on metallized activated carbon can be an alternative to biocatalysis, highlighting the advantages of protease immobilization.

An insight into microbial sources, classification, and industrial applications of xylanases: A rapid review

Endo 1,4-β-d-xylanases (EC3.2.1.8) are one of the key lignocellulose hydrolyzing enzymes. Xylan, which is present in copious amounts on earth, forms the primary substrate of endo-xylanases, which can unchain the constituent monosaccharides linked via β-1,4-glycosidic bonds from the xylan backbone. Researchers have shown keen interest in the xylanases belonging to glycoside hydrolase families 10 and 11, whereas those placed in other glycoside hydrolase families are yet to be investigated. Various microbes such as bacteria and fungi harbor these enzymes for the metabolism of their lignocellulose fibers. These microbes can be used as miniature biofactories of xylanase enzymes for a plethora of environmentally benign applications in pulp and paper industry, biofuel production, and for improving the quality of food in bread baking and fruit juice industry. This review highlights the potential of microbes in production of xylanase for industrial biotechnology.

Enzyme Immobilization Technologies and Industrial Applications

Enzymes play vital roles in diverse industrial sectors and are essential components of many industrial products. Immobilized enzymes possess higher resistance to environmental changes and can be recovered/recycled easily when compared to the free forms. The primary benefit of immobilization is protecting the enzymes from the harsh environmental conditions (e.g., elevated temperatures, extreme pH values, etc.). The immobilized enzymes can be utilized in various large-scale industries, e.g., medical, food, detergent, textile, and pharmaceutical industries, besides being used in water treatment plants. According to the required application, a suitable enzyme immobilization technique and suitable carrier materials are chosen. Enzyme immobilization techniques involve covalent binding, encapsulation, entrapment, adsorption, etc. This review mainly covers enzyme immobilization by various techniques and their usage in different industrial applications starting from 1992 until 2022. It also focuses on the multiscale operation of immobilized enzymes to maximize yields of certain products. Lastly, the severe consequence of the COVID-19 pandemic on global enzyme production is briefly discussed.

Metabolite Profiling of Microwave-Assisted Sargassum fusiforme Extracts with Improved Antioxidant Activity Using Hybrid Response Surface Methodology and Artificial Neural Networking-Genetic Algorithm

Sargassum fusiforme (SF) is a popular edible brown macroalga found in Korea, Japan, and China and is known for its health-promoting properties. In this study, we used two sophisticated models to obtain optimized conditions for high antioxidant activity and metabolite profiling using high-resolution mass spectrometry. A four-factor central composite design was used to optimize the microwave-assisted extraction and achieve the maximum antioxidant activities of DPPH (Y1: 28.01 % inhibition), ABTS (Y2: 36.07 % inhibition), TPC (Y3: 43.65 mg GAE/g), and TFC (Y4: 17.67 mg CAE/g), which were achieved under the optimized extraction conditions of X1: 47.67 %, X2: 2.96 min, X3: 139.54 °C, and X4: 600.00 W. Moreover, over 79 secondary metabolites were tentatively identified, of which 12 compounds were reported for the first time in SF, including five phenolic (isopropyl 3-(3,4-dihydroxyphenyl)-2-hydroxypropanoate, 3,4-dihydroxyphenylglycol, scopoletin, caffeic acid 4-sulfate, and cinnamoyl glucose), two flavonoids (4',7-dihydroxyisoflavone and naringenin), three phlorotannins (diphlorethohydroxycarmalol, dibenzodioxin-1,3,6,8-tetraol, and fucophlorethol), and two other compounds (dihydroxyphenylalanine and 5-hydroxybenzofuran-2(3H)-one) being identified for the first time in optimized SF extract. These compounds may also be involved in improving the antioxidant potential of the extract. Therefore, optimized models can provide better estimates and predictive capabilities that would assist in finding new bioactive compounds with improved biological activities that can be further applied at a commercial level.

Exploring in vitro effect of silver nanoparticles and Holothuria parva extracts on kinetic and stability of α- amylase

Diabetes is a chronic metabolic disorder characterized by elevated blood glucose levels. Major limitations of synthetic drugs, including high cost, efficacy, and adverse side effects, have prompted researchers to seek more effective and low-cost alternative therapies with fewer adverse effects. Marine life forms are considered the most important sources of biologically active natural products due to their secondary metabolites. In this research, sea cucumber Holothuria parva was collected from coastal areas of Bandar Lengeh, Hormozgan, Iran, and was then subjected to extraction. The results showed that compounds extracted from Holothuria parva had a stimulatory effect on enzyme activity, and in the presence of these compounds, the V_max value of the enzyme was increased about two times, while the K_m value was reduced. The phosphate buffer form of extracts had the greatest impact on enzyme activity. Upon an increase in the concentration of silver nanoparticles (AgNPs), the α-amylase activity was inhibited in parallel. Silver nanoparticles exhibited the highest enzyme inhibition with an IC₅₀ of 0.86 mg/mL. Silver nanoparticles showed anti-α-amylase activity and had the ability to decrease intestinal glucose uptake in diabetic individuals when prescribed as a novel supplementary medicine. This article is protected by copyright. All rights reserved.

Highly enhanced activity and stability via affinity induced immobilization β-glucosidase from Aspergillus niger onto amino-based silica for the biotransformation of ginsenoside Rb1

In this study, an enzyme immobilization method for the effective biotransformation of ginsenoside Rb1 to impart activity and stability was developed. Using a hydrolase enzyme model, β-glucosidase from Aspergillus niger, immobilization within chemically affinity-linked amino-based silica provided an immobilization efficiency 5.86-fold higher than that of free enzyme. Compared with the free enzyme, the immobilized enzyme functioned optimally at a wider pH range and had higher thermostability. The optimum pH for the free and immobilized enzymes was 5.5. The optimal reaction temperature of the immobilized enzyme was 45 °C, which was 5 °C higher than that of the free enzyme. The Michaelis constant (K_m) values before and after immobilization were 0.482 mmol•L^-1 and 0.387 mmol•L^-1, respectively. The catalytic rate (K_cat) for the immobilized and free enzymes was 22.269 mmol•L^-1and 8.800 mmol•L^-1, respectively, and the catalytic efficiency (K_cat/K_m) activity of the immobilized enzyme was 3.30-fold higher than that of the free enzyme. The immobilized enzyme could preserve 97 % of the activity after 45 cycles of repeated use. The high catalytic activity and significant operational stability are beneficial for industrial applications.

Characterization and immobilization of protease secreted by the fungus Moorella speciosa

Protease was extracellularly produced in submerged fermentation by the fungus Moorella speciosa with maximum activity of 8.6 × 10³ U/mL. The optimal pH and temperature for enzyme activity were 6.78 and 60.88 °C, respectively. The enzyme was incubated in the presence of several ions at concentrations of 0.1 M and 0.01 M to address the effect on enzyme activity. Enzyme activity was increased by 56% and 130% in the presence of 0.1 M BaCl₂ and of 0.01 M Na₂SO₄, respectively. The V _max and K _m values were 0.01474 U/min/mg protein and 0.04190 mg/mL, respectively. The enzyme retained about 90% of enzymatic activity at 90 °C. Among the methods tested for enzyme immobilization, adsorption onto MAT540 carrier led to the most promising results, since after 15 reuse cycles up to 60% of the initial catalytic activity was retained. Entrapment in calcium alginate matrix allowed to retain up to 51% of the initial catalytic activity after 8 reuse cycles. This protease from M. speciosa, in either free or immobilized form, can be foreseen as a useful biocatalytic tool in process design by reducing operating costs, decreasing the use of chemical processing and, consequently, meeting the global demand for clean technologies.