In this study, porcine pancreatic lipase (EC 3.1.1.3) was immobilized on chitin and chitosan by adsorption and subsequent crosslinking with glutaraldehyde, which was added before (conjugation) or after (crosslinking) washing unbound proteins. Conjugation proved to be the better method for both supports. The properties of free and immobilized enzymes were also investigated and compared. The results showed that the pH optimum was shifted from 8.5 to 9.0 for both the immobilized enzymes. Also, the optimum temperature was shifted from 30 to 40 degrees C for chitin-enzyme and to 45 degrees C for chitosan-enzyme conjugates. The immobilization efficiency is low, but the immobilized enzymes have good reusability and stability (storage and operational). Besides these properties, the immobilized lipases were also suitable for catalyzing esterification reactions of fatty acids and fatty alcohols, both with a medium chain length. According to our results, esterification activities of immobilized lipases were two- and four-fold higher for chitosan- and chitin-enzyme, than for the free enzyme, respectively. The immobilization procedure shows a great potential for commercial applications of the immobilized lipase, a relatively low cost commercial enzyme.
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http://dx.doi.org/10.1080/10826060500533976 | DOI Listing |
Appl Microbiol Biotechnol
January 2025
Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Freiestrasse 3, 3012, Bern, Switzerland.
A new strategy has been developed to successfully produce the active component danshensu ex vivo. For this purpose, phenylalanine dehydrogenase from Bacillus sphaericus was combined with the novel hydroxyphenylpyruvate reductase from Mentha x piperita, thereby providing an in situ cofactor regeneration throughout the conversion process. The purified enzymes were co-immobilized and subsequently employed in batch biotransformation, resulting in 60% conversion of 10 mM L-dopa within 24 h, with a catalytic amount of NAD as cofactor.
View Article and Find Full Text PDFBioresour Technol
January 2025
Department of Biotechnology, Faculty of Biological Science and Technology, University of Isfahan, Isfahan 81746-73441, Iran; Environmental Research Institute, University of Isfahan, Isfahan 81746-73441, Iran.
Tannin-containing sorghum grains, suitable for acetone-butanol-ethanol (ABE) production by Clostridium acetobutylicum, have required pretreatment to eliminate tannins inhibiting the strain's amylolytic activity. This study investigates biobutanol production enhancement by immobilizing enzymes on polydopamine-functionalized polyethersulfone (PES) membranes with magnetic nanoparticles for Separated Hydrolysis and Fermentation (SHF) and Simultaneous Saccharification and Fermentation (SSF) processes. After multi-stage hot water treatment, TG3 sorghum (from the third stage) was used, where the enzyme-immobilized PES membrane produced 4.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
Department of Pharmacy, The Affiliated Hospital of Southwest Medical University, Luzhou 646000, China; School of Pharmacy, Southwest Medical University, Luzhou 646000, China. Electronic address:
Encapsulating enzymes in metal-organic frameworks (MOFs) enhances enzyme protection and improves the accuracy of inhibitor recognition and screening. Zeolitic imidazolate framework-8 (ZIF-8) has been widely used as a host matrix for enzyme immobilization. However, challenges such as the microporous structure and hydrophobicity of ZIF-8, along with the protonation of 2-methylimidazole, hinder the maintenance of activity and the rapid formation of composite.
View Article and Find Full Text PDFToxicon
January 2025
Department of BioMolecular Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, 14040-903, Ribeirão Preto, SP, Brazil. Electronic address:
Snake venoms enzymes affect diverse physiological mechanisms leading to effects such as inflammation, edema, hemolysis, and blood clotting disorders. In this report, we describe modifications to classical assays for assessing the enzymatic activity of snake venom phospholipase A (PLA) and phosphodiesterase (PDE), including the adaptation of the PDE assay to an agar plate. A final staining step, using Stains-all®, was added to the PLA activity assay on an egg yolk-containing agar plate.
View Article and Find Full Text PDFACS Omega
January 2025
School of Biology, University of St Andrews, North Haugh, St Andrews KY16 9ST, U.K.
The synthesis of nucleosides is crucial for pharmaceutical and biotechnological applications, acting as drugs and as essential building blocks for numerous therapeutic agents. However, most enzymes employed in nucleoside biocatalysis are not recycled, possess limited stability, and have strict substrate selection for ribonucleosides or 2'deoxyribonucleosides. We employed 2'-deoxyribonucleoside transferase (NDT) enzymes from thermophilic and psychrophilic bacteria to demonstrate they can be immobilized to enhance specific activity, stability, and recyclability.
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