Green preparation of lipase@Ca3(PO4)2 hybrid nanoflowers using bone waste from food production for efficient synthesis of clindamycin palmitate

Practical and Rapid Membrane-Based Biosensor for Phenol Using Copper/Calcium-Enzyme Hybrid Nanoflowers

Phenol, a pollutant frequently found in chemical industries effluents, is highly toxic even in low concentrations. This study reports a green, simple, and rapid method for qualitative phenol biosensing using horseradish peroxidase (HRP) hybrid nanoflowers made with copper (Cu²⁺-hNF) or calcium (Ca²⁺-hNF) ions. The enzyme was immobilized through protein-inorganic self-assembly into hybrid structures and subsequently supported onto a polyvinylidene fluoride (PVDF) membrane. SEM, EDS, FTIR, and XRD techniques sustained the effective enzyme encapsulation into hybrid structures. The protein concentration in the structures was 0.25 mg.mL^-1 for both ions. The best temperature and pH were 60 °C and 7.4, respectively, for both hybrids and the free enzyme, suggesting that the immobilization did not affect the optimal conditions of the free HRP. Thermal stability from 25 to 70 °C and pH stability from 4.0 to 9.0 of the hybrids were also determined. Finally, using copper and calcium hybrids, both biosensors produced onto a PVDF membrane could detect phenol in concentrations ranging from 0.72 to 24.00 µmol.mL^-1 in 1 min. In contrast, control biosensors produced with free enzyme have not presented a visible color change in the same conditions. The findings suggest a promising application of the developed biosensors in functional phenol detection.

Tuning Immobilized Commercial Lipase Preparations Features by Simple Treatment with Metallic Phosphate Salts

Four commercial immobilized lipases biocatalysts have been submitted to modifications with different metal (zinc, cobalt or copper) phosphates to check the effects of this modification on enzyme features. The lipase preparations were Lipozyme^®TL (TLL-IM) (lipase from Thermomyces lanuginose), Lipozyme^®435 (L435) (lipase B from Candida antarctica), Lipozyme^®RM (RML-IM), and LipuraSelect (LS-IM) (both from lipase from Rhizomucor miehei). The modifications greatly altered enzyme specificity, increasing the activity versus some substrates (e.g., TLL-IM modified with zinc phosphate in hydrolysis of triacetin) while decreasing the activity versus other substrates (the same preparation in activity versus R- or S- methyl mandelate). Enantiospecificity was also drastically altered after these modifications, e.g., LS-IM increased the activity versus the R isomer while decreasing the activity versus the S isomer when treated with copper phosphate. Regarding the enzyme stability, it was significantly improved using octyl-agarose-lipases. Using all these commercial biocatalysts, no significant positive effects were found; in fact, a decrease in enzyme stability was usually detected. The results point towards the possibility of a battery of biocatalysts, including many different metal phosphates and immobilization protocols, being a good opportunity to tune enzyme features, increasing the possibilities of having biocatalysts that may be suitable for a specific process.

Nanoflowers: A New Approach of Enzyme Immobilization

Enzymes are biocatalysts known for versatility, selectivity, and brand operating conditions compared to chemical catalysts. However, there are limitations to their large-scale application, such as the high costs of enzymes and their low stability under extreme reaction conditions. Immobilization techniques can efficiently solve these problems; nevertheless, most current methods lead to a significant loss of enzymatic activity and require several steps of activation and functionalization of the supports. In this context, a new form of immobilization has been studied: forming organic-inorganic hybrids between metal phosphates as inorganic parts and enzymes as organic parts. Compared to traditional immobilization methods, the advantages of these nanomaterials are high surface area, simplicity of synthesis, high stability, and catalytic activity. The current study presents an overview of organic-inorganic hybrid nanoflowers and their applications in enzymatic catalysis.

Organic-inorganic epoxide hydrolase hybrid nanoflowers with enhanced catalytic activity: Hydrolysis of styrene oxide to 1-phenyl-1,2-ethanediol

Epoxide hydrolases are ubiquitous in nature and are utilized to catalyze the cofactor-independent hydrolysis of epoxides to their corresponding diols. These enzymes have tremendous potential and have been applied in the synthesis of bulk and fine chemical industry and utilized as chiral building blocks. Herein, we report a green, facile, and economical method for immobilization of epoxide hydrolase based on biomimetic mineralization. The organic-inorganic hybrid nanoflowers have received tremendous attention due to their higher catalytic activity and stability. The nanoflowers were synthesized, with the organic component being enzyme epoxide hydrolase and the inorganic component being Ca²⁺ ions. A unique hierarchical flower-like spherical structure with hundreds of spiked petals was observed. The synthesized nanoflowers were applied for styrene oxide hydrolysis, producing 1-phenyl-1,2-ethanediol. Further, the factors influencing the morphology, catalytic activity, and stability studies were performed to study the activity recovery of the synthesized organic-inorganic hybrid epoxide hydrolase nanoflowers. The findings will have interesting applications.

Understanding intricacies of bioinspired organic-inorganic hybrid nanoflowers: A quest to achieve enhanced biomolecules immobilization for biocatalytic, biosensing and bioremediation applications

The immobilization of biomolecules has been a subject of interest for scientists for a long time. The organic-inorganic hybrid nanoflowers are a new class of nanostructures that act as a host platform for the immobilization of such biomolecules. It provides better practical applicability to these functional biomolecules while also providing superior activity and reusability when catalysis is involved. These nanostructures have a versatile and straightforward synthesis process and also exhibit enzyme mimicking activity in many cases. However, this facile synthesis involves many intricacies that require in-depth analysis to fully attain its potential as an immobilization technique. A complete account of all the factors involving the synthesis process optimisation is essential to be studied to make it commercially viable. This paper explores all the different aspects of hybrid nanoflowers which sets them apart from the conventional immobilization techniques while also giving an overview of its wide range of applications in industries.

Evaluating the activity and stability of sonochemically produced hemoglobin-copper hybrid nanoflowers against some metallic ions, organic solvents, and inhibitors

The disadvantage of the conventional protein-inorganic hybrid nanoflower production method is the long incubation period of the synthesis method. This period is not suitable for practical industrial use. Herein, protein-inorganic hybrid nanoflowers were synthesized using hemoglobin and copper ion by fast sonication method for 10 min. The synthesized nanoflowers were characterized via scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, and Fouirer-transform infrared spectroscopy. The activity and stability of the nanoflowers in the presence of different metal ions, organic solvents, inhibitors, and storage conditions were also evaluated by comparing with free hemoglobin. According to obtained results, the optimum pH and temperatures of both hybrid nanoflower and free hemoglobin were pH 5 and 40 °C, respectively. At all pH levels, nanoflower was more stable than free protein and it was also more stable than the free hemoglobin at temperatures ranging between 50 °C and 80 °C. The free protein lost more than half of its activity in the presence of acetone, benzene, and N,N-dimethylformamide, while the hybrid nanoflower retained more than 70% of its activity for 2 h at 40 °C. The hybrid nanoflower activity was essentially increased in the presence of Ca²⁺, Zn²⁺, Fe²⁺, Cu²⁺ and Ni²⁺ (132%, 161%, 175%, 185% and 106%, respectively) at 5 mM concentration. The nanoflower retained more than 85% of its initial activity in the presence of all inhibitors. In addition, it retained all its activity for 3 days under different storage conditions, unlike free hemoglobin. The results demonstrated that new hybrid nanoflowers may be promising in different biotechnological applications such as catalytic biosensors and environmental or industrial catalytic processes.

Hydroxyapatite biomaterial production from chicken (femur and beak) and fishbone waste through a chemical less method for Cd2+ removal from shipbuilding wastewater

Hydroxyapatite (HAp) powder was produced from chicken (femur and beak) and fishbone wastes and used as a green adsorbent to decrease Cd²⁺ from aqueous media. The HAp powder was generated at 900 °C and characterized using physicochemical techniques. Chicken femur' HAp (16.72 m²/g) had a higher surface compared to chicken beak and fishbone ones. The solution pH was the most important parameter in removing Cd²⁺. The highest Cd²⁺ removal was achieved at pH 6, temperature of 25 °C, contact time of 80 min, and adsorbent mass of 2 g/L. The Cd²⁺ adsorption data fitted well with the quasi-second-order model in kinetics and the Freundlich model in isotherm. The highest adsorption capacity of Cd²⁺ using HAp-chicken femur, HAp-fish bone, and HAp-chicken beak was determined 22.94 mg/g, 21.54 mg/g, and 21.45 mg/g, respectively. The Cd²⁺ adsorption using HAp powder was a spontaneous and exothermic process and accidental collisions at the liquid-solid interface were reduced. The decrease of Cd²⁺ adsorption efficiency was not significant after multiple recovery steps of the desired powders. In addition to Cd²⁺, other parameters of real wastewater (shipbuilding industry) were reduced by the proposed adsorbents. The utilization of hydroxyapatite powder is expected to be a cheap and eco-friendly method for eliminating metals such as Cd²⁺.

Succinic anhydride-based chemical modification making laccase@Cu3(PO4)2 hybrid nanoflowers robust in removing bisphenol A in wastewater

To prepare a robust biocatalyst and enhance the removal of bisphenol A in wastewater, succinic anhydride was reacted with laccase to obtain succinic anhydride-modified laccase (SA-laccase) and then co-crystallized with Cu₃(PO₄)₂ to form SA-laccase@Cu₃(PO₄)₂ hybrid nanoflowers (hNFs). The activity of SA-laccase@Cu₃(PO₄)₂ reached 5.27 U/mg, 1.86-, 2.88- and 2.15-fold those of bare laccase@Cu₃(PO₄)₂, laccase@Ca₃(PO₄)₂ and laccase@epoxy resin, respectively. Compared with free laccase, the obtained hNFs present enhanced activity and tolerance to pH and high temperature in the removal of BPA. Under the optimum conditions of pH 6.0 and 35 °C, BPA removal reached 93.2% using SA-laccase@Cu₃(PO₄)₂ hNFs, which was 1.21-fold of that using free laccase. In addition, the obtained SA-laccase@Cu₃(PO₄)₂ hNFs retained nearly 90% of their initial catalytic activity for BPA removal after 8 consecutive batch cycles. This efficient method for preparing immobilized laccase can also be further developed and improved to acquire green biocatalysts for removing persistent organic pollutants in wastewater.

Organic-Inorganic Hybrid Nanoflower Production and Analytical Utilization: Fundamental to Cutting-Edge Technologies

Over the past decade, science has experienced a growing rise in nanotechnology with ground-breaking contributions. Through various laborious technologies, nanomaterials with different architectures from 0 D to 3 D have been synthesized. However, the 3 D flower-like organic-inorganic hybrid nanomaterial with the most direct one-pot green synthesis method has attracted widespread attention and instantly become research hotspot since its first allusion in 2012. Mild synthesis procedure, high surface-to-volume ratio, enhanced enzymatic activity and stability are the main factor for its rapid development. However, its lower mechanical strength, difficulties in recovery from the reaction system, lower loading capacity, poor reusability and accessibility of enzymes are fatal, which hinders its wide application in industry. This review first discusses the selection of non-enzymatic biomolecules for the synthesis of hybrid nanoflowers followed by the innovative advancements made in organic-inorganic hybrid nanoflowers to overcome aforementioned issues and to enhance their extensive downstream applications in transduction technologies. Besides, the role of hybrid nanoflower has been successfully utilized in many fields including, water remediation, biocatalyst, pollutant adsorption and decolourization, nanoreactor, biosensing, cellular uptake and others, accompanied with several quantification technologies, such as ELISA, electrochemical, surface plasmon resonance (SPR), colorimetric, and fluorescence were comprehensively reviewed.

Immobilized lipases-based nano-biocatalytic systems - A versatile platform with incredible biotechnological potential

Lipases belong to α/β hydrolases that cause hydrolytic catalysis of triacylglycerols to release monoacylglycerols, diacylglycerols, and glycerol with free fatty acids. Lipases have a common active site that contains three amino acid residues in a conserved Gly-X-Ser-X-Gly motif: a nucleophilic serine residue, an acidic aspartic or glutamic acid residue, and a basic histidine residue. Lipase plays a significant role in numerous industrial and biotechnological processes, including paper, food, oleochemical and pharmaceutical applications. However, its instability and aqueous solubility make application expensive and relatively challenging. Immobilization has been considered as a promising approach to improve enzyme stability, reusability, and survival under extreme temperature and pH environments. Innumerable supporting material in the form of natural polymers and nanostructured materials is a crucial aspect in the procedure of lipase immobilization used to afford biocompatibility, stability in physio-chemical belongings, and profuse binding positions for enzymes. This review outlines the unique structural and functional properties of a large number of polymers and nanomaterials as robust support matrices for lipase immobilization. Given these supporting materials, the applications of immobilized lipases in different industries, such as biodiesel production, polymer synthesis, additives, detergent, textile, and food industry are also discussed.

Armoring bio-catalysis via structural and functional coordination between nanostructured materials and lipases for tailored applications

Nanostructured materials represent an interesting and novel class of support matrices for the immobilization of different enzymes. Owing to the high surface area, robust mechanical stability, outstanding optical, thermal, and electrical properties, nanomaterials have been rightly perceived as desired immobilization matrices for lipases immobilization with a wide array of biotechnological applications such as dairy, food technology, fine chemical, pharmaceutical, detergent, and oleochemical industries. Lipases immobilized on nanomaterials have demonstrated superior attributes than free counterparts, such as aggrandized pH and thermal stability, robustness, long-term stability, and the possibility of reuse and recycling in several times. Here we review current and state-of-the-art literature on the use of nanomaterials as novel platforms for the immobilization of lipase enzymes. The physicochemical properties and exploitation of a large number of new nanostructured materials such as carbon nanotubes, nano-silica, graphene/graphene oxide, metal nanoparticles, magnetic nanostructures, metal-organic frameworks, and hybrid nanoflowers as a host matrix to constitute robust lipases-based nanobiocatalytic systems are discussed. Conclusive remarks, trends, and future recommendations for nanomaterial immobilized enzymes are also given.