Evaluation of amylase immobilization on nanoclay by size exclusion chromatography and its application for starch removal from plant extracts of herbal medicines

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.

The application of conventional or magnetic materials to support immobilization of amylolytic enzymes for batch and continuous operation of starch hydrolysis processes

In the production of ethanol, starches are converted into reducing sugars by liquefaction and saccharification processes, which mainly use soluble amylases. These processes are considered wasteful operations as operations to recover the enzymes are not practical economically so immobilizations of amylases to perform both processes appear to be a promising way to obtain more stable and reusable enzymes, to lower costs of enzymatic conversions, and to reduce enzymes degradation/contamination. Although many reviews on enzyme immobilizations are found, they only discuss immobilizations of α-amylase immobilizations on nanoparticles, but other amylases and support types are not well informed or poorly stated. As the knowledge of the developed supports for most amylase immobilizations being used in starch hydrolysis is important, a review describing about their preparations, characteristics, and applications is herewith presented. Based on the results, two major groups were discovered in the last 20 years, which include conventional and magnetic-based supports. Furthermore, several strategies for preparation and immobilization processes, which are more advanced than the previous generation, were also revealed. Although most of the starch hydrolysis processes were conducted in batches, opportunities to develop continuous reactors are offered. However, the continuous operations are difficult to be employed by magnetic-based amylases.

Nanobiocatalyst consisting of immobilized α-amylase on montmorillonite exhibiting enhanced enzymatic performance based on the allosteric effect

Enzyme immobilization on nanostructured substrates is an emerging method for the efficient development of nanobiocatalysts to enhance enzymatic performance. In this study, a novel α-amylase nanobiocatalytic system was constructed based on the allosteric activation of the enzyme and its immobilization on a natural nanostructured mineral montmorillonite. The strategy of allosteric modulation and immobilization, equipped the immobilized α-amylase with higher catalytic activity and greater stability (compared to those of free α-amylase) over a broad range of pH values (4.5-9.0) and temperatures (30-80 °C). Kinetic experiments revealed that although the immobilized α-amylase possessed a considerably lower affinity for its substrate, its catalytic activity was higher than that of free α-amylase, likely owing to allosteric modulation. Thus, this study demonstrates a convenient and environmentally benign immobilization strategy to construct a nanobiocatalytic α-amylase system that exploits the phenomenon of allosteric activation of the enzyme and lays the foundation for further industrial applications.