Enhanced catalytic performance of Candida rugosa lipase through immobilization on zirconium-2-methylimidazole: A novel biocatalyst approach

A novel halophilic laccase from Halomonas elongata: Purification, characterization, and application in green synthesis of salicylic acid

This study presents the successful one-step purification and characterization of a novel laccase derived from Halomonas elongata, an extremophilic bacterium with promising applications in industrial biocatalysis. The enzyme was purified using a Cu@Fe2O3-NH2@GA hybrid affinity support, exhibiting a specific activity of 377.8 U mg-1 and a molecular weight of ~75 kDa. Characterized by halophilic properties, the laccase exhibited maximum activity at pH 9 and in the presence of 1.5 mM NaCl, demonstrating remarkable stability in organic solvents and against various inhibitors. The enzyme was successfully applied to the green synthesis of salicylic acid from its alcohol precursor, achieving an 89.9 % yield under optimized conditions: 325.9 U mL-1 laccase, 15.8 mM TEMPO, 36 % solvent-to-buffer ratio, and 38.7 °C. These findings demonstrate the potential of this newly identified laccase as a promising biocatalyst for industrial applications, particularly in eco-friendly organic synthesis.

Bilayer electrospun nanofibrous membrane: A matrix for lipase immobilization with high stability and reusability and its application on the synthesis of benzyl acetate

A cold-adapted recombinant lipase from the deep-sea psychrophilic bacterium Psychrobacter sp. C18 was purified and immobilized onto glutaraldehyde-activated bilayer nanofibers (BNFs) composed of polycaprolactone, chitosan, polyvinyl alcohol, and zinc oxide (PCL/Cs/PVA/ZnO), fabricated by electrospinning. The nanofibers were characterized using Scanning Electron Microscopy and Fourier Transform Infrared Spectroscopy, confirming their favorable morphology and chemical structure. Immobilization of Lipase C18 onto BNFs led to notable biochemical changes. While the free enzyme showed optimum activity at pH 8.0, the immobilized form shifted to ~pH 6.0, likely due to local microenvironmental effects. The immobilized lipase exhibited improved thermal and pH stability, enhanced storage durability, and better tolerance to mono- and divalent metal ions such as Na+, Fe2+, and Mg2+. Operational stability tests demonstrated that 91 % of enzymatic activity was retained after 20 reuse cycles. In transesterification reactions, the immobilized enzyme outperformed the free form, yielding more benzyl acetate, emphasizing its potential in fragrance and cosmetic industries. The bilayer nanofiber system provided superior performance over conventional immobilization supports, with the hydrophilic top layer enhancing wettability and the matrix structure improving enzyme functionality and robustness.

Immobilization of glycosyltransferase into a hydrophilic metal-organic framework for efficient biosynthesis of chondroitin sulfate

Chondroitin sulfate (CS) is a structurally complex anionic polysaccharide widely used in medical, cosmetic and food applications. Enzymatic catalysis is an important strategy for synthesizing CS with uniform chain lengths and well-defined structures. However, the industrial application of glycosyltransferases is hindered by limitations such as low expression yields, poor stability, and challenges in reuse. We developed a mild and rapid one-step synthetic method for the efficient immobilization of chondroitin synthase (KfoC). The resulting KfoC@ZIF-90 composite exhibits high catalytic activity, thermal stability, and pH adaptability. Notably, KfoC@ZIF-90 exhibited 5-fold enhanced thermal stability at 40°C and retained 86 % relative activity at pH 10, while also maintaining 90 % activity in organic solvents, surpassing the performance of free KfoC. Molecular docking analysis revealed that the binding capability of encapsulated KfoC with substrate was stronger than that of free KfoC, thereby improving catalytic performance. Furthermore, KfoC@ZIF-90 can be easily separated from the reaction solution by centrifugation, simplifying product isolation and purification while enabling enzyme reuse. These attributes significantly enhance operability and reduce processing costs, making enzymatic CS synthesis more feasible for industrial applications.

Removal of phthalate esters by integrated adsorption and biodegradation using improved performance of lipase@MOFs

Phthalate esters (PAEs) are broadly utilized as plasticizers in industrial products, posing a significant threat to ecological security and human health. Lipase is a kind of green biocatalyst with the ability to degrade PAEs, but its application is limited due to its low stability and poor reusability. Herein, lipase from Candida rugosa (CRL) was immobilized into an organic ligand replacement MOFs (MAF-507) and cysteine modification and glutaraldehyde cross-linking were simultaneously performed to synthesize immobilized lipase (Cys-CRL@GA@MAF-507) using a one-pot method. Compared with free CRL, Cys-CRL@GA@MAF-507 not only increased its relative activity to 1.66-fold as well as improved its thermostability to 247% at 30 °C, but also constructed a synergistic system of combined adsorption and biodegradation to remove PAEs. In actual water environment, Cys-CRL@GA@MAF-507 could adsorb 88.56% of dibutyl phthalate (DBP) within 5 min and degrade 94.6% of DBP within 48 h, respectively. Therefore, this research developed an innovative bifunctional enzyme@MOFs biocomposite with synergistic adsorption and biodegradation for the efficient removal of PAEs, which provides a new platform for the elimination of pollutants in environmental remediation and industrial application.

The current research status of immobilized lipase performance and its potential for application in food are developing toward green and healthy direction: A review

Immobilized lipases have received great attention in food, environment, medicine, and other fields due to their easy separation, high stability (temperature, pH), and high storage properties. After immobilization, lipase transforms from a homogeneous to a heterogeneous state, making it easier to recover from the reaction substrate and achieve recycling, which is in line with the concept of green chemistry and reduces protein contamination in the product. There are various materials for enzyme immobilization, including polysaccharides from natural sources, inorganic compounds, carbon nanotubes, metal-organic framework materials, and so forth. Magnetic immobilization carriers have been widely studied due to their ability to achieve separation by adding a magnetic field. Its immobilization method can be simply divided into two categories: physical action (adsorption, embedding) and chemical binding (covalent, cross-linking). Some studies mainly discuss the immobilization support materials, immobilization methods, and applications of immobilized lipases in food. On this basis, our review also focuses on the changes in crosslinking agents for immobilized lipases, different methods to promote immobilization, new trends in the study of immobilized lipases, and proposes prospects for immobilized lipase research in the food industry.