Enhanced stability and catalytic performance of laccase immobilized on magnetic graphene oxide modified with ionic liquids

Enhancing the Stability and Anticancer Activity of Escherichia coli Asparaginase Through Nanoparticle Immobilization: A Biotechnological Perspective on Nano Chitosan

There is a shortage in the experimental research directly comparing the effectiveness of different nanoparticles in boosting asparaginase (ASNase) activity. This study assessed the impact of various nanoparticles on enhancing ASNase activity, stability, and anticancer effects through immobilization. Escherichia coli ASNase was immobilized on different nanoparticles, and its efficiency was measured. The research included analyzing the enzyme's secondary structure, stability, activity at different temperatures, kinetic parameters, shelf life, and activity in blood serum. The anticancer efficacy was determined by measuring the IC50. The study also investigated the anticancer mechanisms by examining the enzyme's toxicity on cancer cells, focusing on apoptosis indicators like nuclear intensity, membrane permeability, mitochondrial membrane permeability, and cytochrome c release. Among the tested nanoparticles, nano chitosan yielded the best improvements. ASNase immobilized on nano chitosan reached 90% immobilization efficiency fastest among the studied nanoparticles, achieving this within 72 h, whereas other nanoparticles took 120 h. Immobilization modified ASNase's secondary structure by increasing alpha helices and reducing random coils, with nanochitosan and magnetic iron oxide showing the most pronounced effects. Immobilized ASNase exhibited enhanced activity, stability across temperature (widest with nanochitosan, 25-65 °C), and a broader optimal pH range compared to the free enzyme, with a Km of 1.227 mM and a Vmax of 454.54 U/mg protein. Notably, the nano-chitosan-immobilized ASNase retained over 85% of its activity after 9 months of storage and maintained high activity in blood serum. This improved stability and activity translated into the highest anticancer activity (Lowest IC50) and was more effective than doxorubicin in disrupting cancer cell structures.

Dendrimer templated ionic liquid nanomagnetic for efficient coupling reactions

In this research, a logical strategy with a recyclable synthetic perspective of view and a rational design to prepare a nanocatalyst with a dendrimer template containing ionic liquid is presented. Magnetic silica nanoparticles were prepared using the Stober method. Their surface was modified with the help of cyanuric chloride, melamine, and 1-methylimidazole as Linkers. Finally, the nanocatalyst was decorated with affordable copper metal. The dendrimer-templated nanocatalyst was identified by different analyses, such as FT-IR, SEM, TEM, XRD, EDX, TGA, CHN, and ICP-OES. Fe3O4@SiO2@NTMP-IL-Cu was used as a heterogeneous nanocatalyst with good performance and reusable in coupling syntheses. The synthesis of A3-coupling and Ullmann coupling was performed under solvent-free and THF conditions, respectively, with high yields. Reusability and high efficiency of products in the vicinity of this catalyst, the use of cheap and available metal are desirable features of this synthetic catalyst.

Microbial Immobilized Enzyme Biocatalysts for Multipollutant Mitigation: Harnessing Nature's Toolkit for Environmental Sustainability

The ever-increasing presence of micropollutants necessitates the development of environmentally friendly bioremediation strategies. Inspired by the remarkable versatility and potent catalytic activities of microbial enzymes, researchers are exploring their application as biocatalysts for innovative environmental cleanup solutions. Microbial enzymes offer remarkable substrate specificity, biodegradability, and the capacity to degrade a wide array of pollutants, positioning them as powerful tools for bioremediation. However, practical applications are often hindered by limitations in enzyme stability and reusability. Enzyme immobilization techniques have emerged as transformative strategies, enhancing enzyme stability and reusability by anchoring them onto inert or activated supports. These improvements lead to more efficient pollutant degradation and cost-effective bioremediation processes. This review delves into the diverse immobilization methods, showcasing their success in degrading various environmental pollutants, including pharmaceuticals, dyes, pesticides, microplastics, and industrial chemicals. By highlighting the transformative potential of microbial immobilized enzyme biocatalysts, this review underscores their significance in achieving a cleaner and more sustainable future through the mitigation of micropollutant contamination. Additionally, future research directions in areas such as enzyme engineering and machine learning hold immense promise for further broadening the capabilities and optimizing the applications of immobilized enzymes in environmental cleanup.

Octadecyl and sulfonyl modification of diatomite synergistically improved the immobilization efficiency of lipase and its application in the synthesis of pine sterol esters

Phytosterols usually have to be esterified to various phytosterol esters to avoid their disadvantages of unsatisfactory solubility and low bioavailability. The enzymatic synthesis of phytosterol esters in a solvent-free system has advantages in terms of environmental friendliness, sustainability, and selectivity. However, the limitation of the low stability and recyclability of the lipase in the solvent-free system, which often requires a relatively high temperature to induce the viscosity, also increased the industrial production cost. In this context, a low-cost material, namely diatomite, was employed as the support in the immobilization of Candida rugosa lipase (CRL) due to its multiple modification sites. The Fe3 O4 was also then introduced to this system for quick and simple separation via the magnetic field. Moreover, to further enhance the immobilization efficiency of diatomite, a modification strategy which involved the octadecyl and sulfonyl group for regulating the hydrophobicity and interaction between the support and lipase was successfully developed. The optimization of the ratio of the modifiers suggested that the -SO3 H/C18 (1:1.5) performed best with an enzyme loading and enzyme activity of 84.8 mg·g-1 and 54 U·g-1 , respectively. Compared with free CRL, the thermal and storage stability of CRL@OSMD was significantly improved, which lays the foundation for the catalytic synthesis of phytosterol esters in solvent-free systems. Fortunately, a yield of 95.0% was achieved after optimizing the reaction conditions, and a yield of 70.0% can still be maintained after six cycles.