Preparation of highly reusable biocatalysts by immobilization of lipases on epoxy-functionalized silica for production of biodiesel from canola oil

Immobilized Candida antarctica lipase B (CALB) for biodiesel production from rapeseed oil; evaluation of the effect of immobilization protocol

The catalytic performance of Candida antarctica lipase B (CALB) immobilized on silica-coated magnetic nanoparticles was evaluated for biodiesel production via methanolysis of rapeseed oil. Two different covalent immobilization approaches were compared to assess the effect of immobilization protocols on lipase efficiency. The first approach involved immobilization of CALB on amine-functionalized magnetic nanoparticles (MNPs), which targeted the Lys-rich regions of the enzyme. The second used epoxy-functionalized MNPs, enabling broader nucleophilic groups on the enzyme surface to participate in the coupling reaction. Immobilization of 20 mg of CALB on 1 g of each support resulted in 82 % and 86 % protein loading on the amine- and epoxy-functionalized MNPs, respectively, after 24 h of incubation. Response surface methodology (RSM) was applied to optimize biodiesel production by analyzing the effects of parameters such as reaction temperature, time, t-butanol concentration, biocatalyst loading, and molecular sieve quantity on the yield of fatty acid methyl esters (FAME). Out of 45 designed experiments, the maximum FAME yields were 92 % and 84 % for the epoxy- and amine-functionalized MNPs, respectively.

A Comprehensive Guide to Enzyme Immobilization: All You Need to Know

Enzyme immobilization plays a critical role in enhancing the efficiency and sustainability of biocatalysis, addressing key challenges such as limited enzyme stability, short shelf life, and difficulties in recovery and recycling, which are pivotal for green chemistry and industrial applications. Classical approaches, including adsorption, entrapment, encapsulation, and covalent bonding, as well as advanced site-specific methods that integrate enzyme engineering and bio-orthogonal chemistry, were discussed. These techniques enable precise control over enzyme orientation and interaction with carriers, optimizing catalytic activity and reusability. Key findings highlight the impact of immobilization on improving enzyme performance under various operational conditions and its role in reducing process costs through enhanced stability and recyclability. The review presents numerous practical applications of immobilized enzymes, including their use in the pharmaceutical industry for drug synthesis, in the food sector for dairy processing, and in environmental biotechnology for wastewater treatment and dye degradation. Despite the significant advantages, challenges such as activity loss due to conformational changes and mass transfer limitations remain, necessitating tailored immobilization protocols for specific applications. The integration of immobilization with modern biotechnological advancements, such as site-directed mutagenesis and recombinant DNA technology, offers a promising pathway for developing robust, efficient, and sustainable biocatalytic systems. This comprehensive guide aims to support researchers and industries in selecting and optimizing immobilization techniques for diverse applications in pharmaceuticals, food processing, and fine chemicals.

Hyperactivation of lipases by immobilization on superhydrophobic graphene quantum dots inorganic hybrid nanoflower

Various nanoflowers are synthesized for enzyme immobilization. In order to increase the activity of nanoflowers, in this study, 3D flower-like structured organic-inorganic hybrid nanoflowers (hNFs) with various lipases Rhizomucor miehei lipase (RML), Candida antarctica lipase B (CALB), Humicola insolens lipase (HIL), Thermomyces lanuginosus lipase (TLL), Eversa® Transform 2.0 (ET) a genetically modified enzyme derived of TLL and graphene quantum dots (GQDs) were prepared and characterized.Lipase hNFs [lipase-(Cu/Co)3(PO4)2] and lipase@GQDs hNFs [lipase@GQDs-(Cu/Co)3(PO4)2] were straightforwardly prepared through mixing with metal ion (Cu2+or Co2+) aqueous solutions with or without GQDs. The ET@GQDs-(Cu)3(PO4)2 hNFs demonstrated 687 % higher activity than ET-(Cu)3(PO4)2 hNFs and 650 % higher activity than the free ET. Similar results were also observed with other lipase hybrid nanoflowers. For example, TLL@GQDs-(Cu)3(PO4)2 hNFs exhibited a 557 % higher activity than TLL-(Cu)3(PO4)2 hNFs and a 463 % higher activity than free TLL. Additionally, TLL@GQDs-(Co)3(PO4)2 hNFs showed a 141 % higher activity than TLL-(Co)3(PO4)2 hNFs and a 304 % higher activity than free TLL. Upon examining pH and thermal stability, it was revealed that lipase@GQDs hNFs exhibited higher activity compared to free lipase and other hNFs without GQDs. The effect of metal ions, enzyme concentrations and amount of GQDs on the morphology and enzyme activity of the lipase-hNFs was examined.

Hydroxyapatite Incorporated with Fe3O4@MCM-41 Core-Shell: A Promising Nanocomposite for Teriparatide Delivery in Bone Tissue Regeneration

This article presents a comprehensive study of the development of a novel nanocomposite comprising core-shell Fe3O4@MCM-41 with superparamagnetic properties and hydroxyapatite (HAp). The nanocomposite serves as a pH-responsive nanocarrier, offering an efficient injectable dosage for teriparatide (PTH (1-34)) delivery. The aim is to address the limitations associated with drug-induced side effects, precautionary measures, and frequent injections. The nanocomposites, as prepared, were characterized using techniques including X-ray diffraction, Fourier transform infrared, zeta potential, dynamic light scattering, VSM, scanning electron microscopy, and transmission electron microscopy. The nanocomposites' average crystallite diameter was determined to be 27 ± 5 nm. The hydrodynamic size of the PTH (1-34)-loaded nanocarrier ranged from 357 to 495 nm, with a surface charge of -33 mV. The entrapment and loading efficiencies were determined to be 73% and 31%, respectively. All of these findings collectively affirm successful fabrication. Additionally, in vivo medication delivery was investigated using the HPLC method, mirroring the in vitro tests. Utilizing the dialysis approach, we demonstrated sustained-release behavior. PTH (1-34) diffusion increased as the pH decreased from 7.4 to 5.6. After 24 h, drug release was higher at acidic pH (88%) compared to normal pH (43%). The biocompatibility of the PTH (1-34)-loaded nanocarrier was assessed using the MTT assay employing the NIH3T3 and HEK-293 cell lines. The results demonstrated that the nanocarrier not only exhibited nontoxicity but also promoted cell proliferation and differentiation. In the in vivo test, the drug concentration reached 505 μg within 30 min of exposure to the magnetic field. Based on these findings, the Fe3O4@MCM-41/HAp/PTH (1-34) nanocomposite, in combination with a magnetic field, offers an efficient and biocompatible approach to enhance the therapeutic effect of osteogenesis and overcome drug limitations.

Isocyanide-based multi-component reactions for carrier-free and carrier-bound covalent immobilization of enzymes

Strategies for the covalent immobilization of enzymes depend on the type of functional group selected to perform the coupling reaction, and on the relative importance of selectivity, loading capacity, immobilization time and activity/stability of the resulting immobilized preparation. However, no single strategy is applicable for all covalent immobilization methods or can meet all these criteria, exemplifying the challenge of introducing a versatile process broadly compatible with the residues on the surface of proteins and the functional groups of common linkers. Here, we describe the use of isocyanide-based multi-component reactions for the carrier-bound and carrier-free covalent immobilization of enzymes. Isocyanide-based multi-component reactions can accept a wide variety of functional groups such as epoxy, acid, amine and aldehyde, as well as many commercially available bi-functional linkers, and are therefore suitable for either covalent coupling of enzymes on a solid support or intermolecular cross-linking of enzymes. In this strategy, an isocyanide is directly added to the reaction medium, the enzyme supplies either the exposed amine or carboxylic acid groups, and the support (in carrier-bound immobilization) or the bi-functional cross-linking agent (in carrier-free immobilization) provides another reactive functional group. The protocol offers operational simplicity, high efficiency and a notable reduction in time over alternative strategies, and can be performed by users with expertise in chemistry or biology. The immobilization reactions typically require 1-24 h.

A multi-component reaction for covalent immobilization of lipases on amine-functionalized magnetic nanoparticles: production of biodiesel from waste cooking oil

A new approach was used for the immobilization of Thermomyces lanuginosus lipase (TLL), Candida antarctica lipase B (CALB), and Rhizomucor miehei lipase (RML) on amine-functionalized magnetic nanoparticles (Fe3O4@SiO2-NH2) via a multi-component reaction route (using cyclohexyl isocyanide). The used method offered a single-step and very fast process for covalent attachment of the lipases under extremely mild reaction conditions (25 °C, water, and pH 7.0). Rapid and simple immobilization of 20 mg of RML, TLL, and CALB on 1 g of the support produced 100%, 98.5%, and 99.2% immobilization yields, respectively, after 2 h of incubation. The immobilized derivatives were then used for biodiesel production from waste cooking oil. Response surface methodology (RSM) in combination with central composite rotatable design (CCRD) was employed to evaluate and optimize the biodiesel production. The effect of some parameters such as catalyst amount, reaction temperature, methanol concentration, water content for TLL or water-adsorbent for RML and CALB, and ratio of t-butanol (wt%) were investigated on the fatty acid methyl esters (FAME) yield.

Aspergillus niger based lipase-tween 80 aggregates as interfacial activated biocatalyst for biodiesel production: Optimization using response surface methodology

Biodiesel is a renewable energy source, which is produced through transesterification reactions. Despite great attention to develop enzymatic biodiesel production, there are serious obstacles to the industrial development of it such as its cost and slow reaction rate. Along with disadvantages, there are several advantages for enzymatic biodiesel production. Higher purity of fuel and glycerol is known as the most important achievement of enzymatic process. In this study, performance of four different fungi for lipase production was investigated and Aspergillus niger was selected as enzyme source. Lipase production were optimized using experimental design and the optimized factors were determined as pH 5, temperature 30 °C, Potato Dextrose Broth (PDB) 3 % w/v, olive oil 1.50 % v/v, with maximum lipase activity of 42.8±0.51 U/mg. In order to interfacial activation of the lipase, effect of surfactants was studied. Therefore, surfactant-enzyme aggregates were used as biocatalyst for transesterification reaction. Effects of factors on biodiesel yield were studied too. The yield was 96.41±1.20 % at the optimized conditions (methanol/oil molar ratio (5.50:1), enzyme concentration 19 % v/ w, Tween 80 concentration 19 mg L– 1, temperature 40 °C and reaction time 46 h).

A Review of the Existing Potentials in Biodiesel Production in Iran

Petroleum fuel plays an important role in industry, transportation, agriculture and other related industries in Iran. Iran has about 9.5% of the world’s total oil reserves in 2020 and is ranked 4th in the world. The presence of sufficient conventional fossil fuels for internal combustion engines has caused environmental problems. If these Iranian fossil fuels were to run out right now, there is no suitable alternative that is just as effective. The need to research alternative fuels in Iran is therefore unavoidable. In this study, the potential and available resources of raw materials, including rapeseed oil, palm oil, fish oil, waste oil, algae, animal fat, olive oil and jatropha oil for biodiesel production in different regions of Iran, have been reviewed. Given the potentials and resources described in this study, it is hoped that the findings of this study will play an important role in biodiesel production in Iran in the future and stimulate more researchers to create biodiesel from existing sources. It is also expected that this study will increase the attention of the governmental and non-governmental organizations in Iran to the existing resources for biodiesel production and development of these resources and get rid of the existing problems of fossil fuels by investing in this field.

Fast anisotropic growth of the biomineralized zinc phosphate nanocrystals for a facile and instant construction of laccase@Zn3(PO4)2 hybrid nanoflowers

Organic-inorganic hybrid nanoflowers (HNFs) of laccase@Zn₃(PO₄)₂ were fabricated through a facile, simple, and rapid one-step strategy. In this process, laccase was involved in nucleation and fast anisotropic growth reactions with Zn (II) and phosphate ions. The average pore size of the prepared HNFs was 54.5 nm, and its BET-specific surface area was 59.5 m² g^-1. In comparison with the free laccase, the entrapped enzyme activity in the constructed HNFs was 86.4%. In addition, the hybrid biocatalyst displayed a maximum rate of reaction (V_max) of 1640.2 ± 3.6 μmol min^-1 with respect to the native enzyme. The constructed HNFs maintained 45.1% and 60% of the original laccase activity after 12 successive reusability cycles and 30 days of storage at 4 °C, respectively. The as-obtained HNFs demonstrated a high bioremoval percentage of Direct blue-71 (94.1%) within a 10-h-treatment at 40 °C and 15 mg l^-1 of the dye concentration. The pseudo-first order and second order were the best-fitted kinetic models for the dye removal using Zn₃(PO₄)₂ nanoflakes and the fabricated HNFs, respectively. Besides, liquid chromatography-mass spectrometry (LC-MS) revealed biotransformation of the dye into less toxic metabolites as verified by testing on some bacterial strains.

Enzymes, In Vivo Biocatalysis, and Metabolic Engineering for Enabling a Circular Economy and Sustainability

Since the industrial revolution, the rapid growth and development of global industries have depended largely upon the utilization of coal-derived chemicals, and more recently, the utilization of petroleum-based chemicals. These developments have followed a linear economy model (produce, consume, and dispose). As the world is facing a serious threat from the climate change crisis, a more sustainable solution for manufacturing, i.e., circular economy in which waste from the same or different industries can be used as feedstocks or resources for production offers an attractive industrial/business model. In nature, biological systems, i.e., microorganisms routinely use their enzymes and metabolic pathways to convert organic and inorganic wastes to synthesize biochemicals and energy required for their growth. Therefore, an understanding of how selected enzymes convert biobased feedstocks into special (bio)chemicals serves as an important basis from which to build on for applications in biocatalysis, metabolic engineering, and synthetic biology to enable biobased processes that are greener and cleaner for the environment. This review article highlights the current state of knowledge regarding the enzymatic reactions used in converting biobased wastes (lignocellulosic biomass, sugar, phenolic acid, triglyceride, fatty acid, and glycerol) and greenhouse gases (CO₂ and CH₄) into value-added products and discusses the current progress made in their metabolic engineering. The commercial aspects and life cycle assessment of products from enzymatic and metabolic engineering are also discussed. Continued development in the field of metabolic engineering would offer diversified solutions which are sustainable and renewable for manufacturing valuable chemicals.

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.

Design of epidermal growth factor immobilization on 3D biocompatible scaffolds to promote tissue repair and regeneration

Exogenous application of human epidermal growth factor (hEGF) stimulates epidermal wound healing. The aim of this study was to develop bioconjugates based on hEGF mimicking the protein in its native state and thus suitable for tissue engineering applications, in particular for treating skin-related disorders as burns. Ribonuclease A (RNase A) was used to investigate a number of different activated-agarose carriers: cyanogen bromide (CNBr)-activated-agarose and glyoxyl-agarose showed to preserve the appropriate orientation of the protein for receptor binding. EGF was immobilized on these carriers and immobilization yield was evaluated (100% and 12%, respectively). A peptide mapping of unbound protein regions was carried out by LC-MS to take evidence of the residues involved in the immobilization and, consequently, the flexibility and surface accessibility of immobilized EGF. To assess cell proliferative activities, 10, 25, 50, and 100 ng/mL of each immobilized EGF sample were seeded on fibroblast cells and incubated for 24, 48 and 72 h. The immobilized growth factor showed significantly high cell proliferative activity at 50 and 100 ng/mL compared to control and soluble EGF. Although both of the immobilized samples show dose-dependency when seeded with high number of fibroblast cells, CNBr-agarose-EGF showed a significantly high activity at 100 ng/mL and 72 h incubation, compared to glyoxyl-agarose-EGF.

Preparation of highly diffusible porous cross-linked lipase B from Candida antarctica conjugates: Advances in mass transfer and application in transesterification of 5-Hydroxymethylfurfural

The present work pronounces the three phase partitioning (TPP)-facilitated preparation of porous cross-linked Candida antarctica lipase B (CaLB) aggregates (pCLEAs) for 5-Hydroxymethylfurfural (HMF) esters synthesis. CLEAs and pCLEAs of CaLB were prepared with eupergit as the support under the optimized conditions of pH 8.0, eupergit/protein ratio of 3.0:1.0, 50 mM cross-linker concentration and 3.3 mg/mL BSA concentration in 4 h. The optimum starch concentration for pCLEAs was 0.20%, m/v. The maximum biocatalytic load was 650 U/g (CLEAs) and 721 U/g (pCLEAs), and the immobilized biocatalysts were stable over a pH range of 6.0-9.0 and temperature range of (40-60)°C. The BET surface area of CLEAs and pCLEAs were 21.3 and 29.1 m²/g, respectively, and the catalytic efficiency of pCLEAs was 2.2-fold higher than that of CLEAs. Subsequently, the pCLEAs of CaLB were utilized for the manufacturing of industrially significant HMF esters. Under the optimized transesterification conditions, HMF conversion with pCLEAs CaLB was 1.41- and 1.25-fold higher than with free and CLEAs CaLB, respectively. The pCLEAs were reused upto 8 consecutive transesterification cycles and the produced HMF esters reduced the surface tension of water from 72 mN/m to 32.6 mN/m, proving its potential application as surface-active compounds.

Improvement of biodiesel production from palm oil by co-immobilization of Thermomyces lanuginosa lipase and Candida antarctica lipase B: Optimization using response surface methodology

Candida antarctica lipase B (CALB) and Thermomyces lanuginose lipase (TLL) were co-immobilized on epoxy functionalized silica gel via an isocyanide-based multicomponent reaction. The immobilization process was carried out in water (pH 7) at 25 °C, rapidly (3 h) resulting in high immobilization yields (100%) with a loading of 10 mg enzyme/g support. The immobilized preparations were used to produce biodiesel by transesterification of palm oil. In an optimization study, response surface methodology (RSM) and central composite rotatable design (CCRD) methods were used to study the effect of five independent factors including temperature, methanol to oil ratio, t-butanol concentration and CALB:TLL ratio on the yield of biodiesel production. The optimum combinations for the reaction were CALB:TLL ratio (2.1:1), t-butanol (45 wt%), temperature (47 °C), methanol: oil ratio (2.3). This resulted in a FAME yield of 94%, very close to the predicted value of 98%.

Immobilization of alcohol dehydrogenase from Saccharomyces cerevisiae onto carboxymethyl dextran-coated magnetic nanoparticles: a novel route for biocatalyst improvement via epoxy activation

A novel method is described for the immobilization of alcohol dehydrogenase (ADH) from Saccharomyces cerevisiae onto carboxymethyl dextran (CMD) coated magnetic nanoparticles (CMD-MNPs) activated with epoxy groups, using epichlorohydrin (EClH). EClH was used as an activating agent to bind ADH molecules on the surface of CMD-MNPs. Optimal immobilization conditions (activating agent concentration, temperature, rotation speed, medium pH, immobilization time and enzyme concentration) were set to obtain the highest expressed activity of the immobilized enzyme. ADH that was immobilized onto epoxy-activated CMD-MNPs (ADH-CMD-MNPs) maintained 90% of the expressed activity. Thermal stability of ADH-CMD-MNPS after 24 h at 20 °C and 40 °C yielded 79% and 80% of initial activity, respectively, while soluble enzyme activity was only 19% at 20 °C and the enzyme was non-active at 40 °C. Expressed activity of ADH-CMD-MNPs after 21 days of storage at 4 °C was 75%. Kinetic parameters (K_M, v_max) of soluble and immobilized ADH were determined, resulting in 125 mM and 1.2 µmol/min for soluble ADH, and in 73 mM and 4.7 µmol/min for immobilized ADH.

A comprehensive review on incredible renewable carriers as promising platforms for enzyme immobilization & thereof strategies

Enzymes are the highly versatile bio-catalysts having the potential for being employed in biotechnological and industrial sectors to catalyze biosynthetic reactions over a commercial point of view. Immobilization of enzymes has improved catalytic properties, retention activities, thermal and storage stabilities as well as reusabilities of enzymes in synthetic environments that have enthralled significant attention over the past few years. Dreadful efforts have been emphasized on the renewable and synthetic supports/composite materials to reserve their inherent characteristics such as biocompatibility, non-toxicity, accessibility of numerous reactive sites for profitable immobilization of biological molecules that often serve diverse applications in the pharmaceutical, environmental, and energy sectors. Supports should be endowed with unique physicochemical properties including high specific surface area, hydrophobicity, hydrophilicity, enantioselectivities, multivalent functionalization which professed them as competent carriers for enzyme immobilization. Organic, inorganic, and nano-based platforms are more potent, stable, highly recovered even after used for continuous catalytic processes, broadly renders the enzymes to get efficiently immobilized to develop an inherent bio-catalytic system that displays higher activities as compared to free-counter parts. This review highlights the recent advances or developments on renewable and synthetic matrices that are utilized for the immobilization of enzymes to deliver emerging applications around the globe.

Magnetic responsive Thermomyces lanuginosus lipase for biodiesel synthesis

The low cost lipase derived from Thermomyces lanugionous was chosen to conjugate with Fe₃O₄ nanoparitcles as a magnetic responsive lipase (MRL) biocatalyst. The structure of MRL was observed by atomic force microscopy (AFM). The Fourier transform infrared (FTIR) spectroscopy analysis confirmed the lipase conjugated to Fe₃O₄ nanoparticles. Optimized conditions for the process of biodiesel production by MRL were investigated by the response surface methodology (RSM) and the Box-Behnken design (BBD). The optimized conditions for biodiesel production by MRL were as follows. The molar ratio of methanol to oil was 4.0, water content was 1.5 % as oil weight, the dosage of MRL to oil was 9.0 % (W/W) under 41 °C for 28 h. Under the optimized conditions, the yield of FAMEs by MRL reached 82.20 %. Further experiments showed that the MRL could be used 10 cycles and the yield of FAMEs decreased slightly by 10.97 %. These results indicated that Fe₃O₄ nanoparticle carrier could efficiently improve the FAMEs synthesis and enhance the MRL stabilization and reusability in the biodiesel production.

Lipase From Rhizomucor miehei Immobilized on Magnetic Nanoparticles: Performance in Fatty Acid Ethyl Ester (FAEE) Optimized Production by the Taguchi Method

In this communication, it was evaluated the production of fatty acid ethyl ester (FAAE) from the free fatty acids of babassu oil catalyzed by lipase from Rhizomucor miehei (RML) immobilized on magnetic nanoparticles (MNP) coated with 3-aminopropyltriethoxysilane (APTES), Fe₃O₄@APTES-RML or RML-MNP for short. MNPs were prepared by co-precipitation coated with 3-aminopropyltriethoxysilane and used as a support to immobilize RML (immobilization yield: 94.7 ± 1.0%; biocatalyst activity: 341.3 ± 1.2 U_p–NPB/g), which were also activated with glutaraldehyde and then used to immobilize RML (immobilization yield: 91.9 ± 0.2%; biocatalyst activity: 199.6 ± 3.5 U_p–NPB/g). RML-MNP was characterized by X-Ray Powder Diffraction (XRPD), Fourier Transform-Infrared (FTIR) spectroscopy and Scanning Electron Microscope (SEM), proving the incorporation and immobilization of RML on the APTES matrix. In addition, the immobilized biocatalyst presented at 60°C a half-life 16–19 times greater than that of the soluble lipase in the pH range 5–10. RML and RML-MNP showed higher activity at pH 7; the immobilized enzyme was more active than the free enzyme in the pH range (5–10) analyzed. For the production of fatty acid ethyl ester, under optimal conditions [40°C, 6 h, 1:1 (FFAs/alcohol)] determined by the Taguchi method, it was possible to obtain conversion of 81.7 ± 0.7% using 5% of RML-MNP.

Facile One-Pot Immobilization of a Novel Thermostable Carboxylesterase from Geobacillus uzenensis for Continuous Pesticide Degradation in a Packed-Bed Column Reactor

The novel carboxylesterase gene (est741) was cloned from Geobacillus uzenensis. The optimal pH and temperature of Est741 were 8.0 and 50 °C. Through site-directed mutation, the optimum temperature of the mutant M160K(EstM160K) was increased from 50 to 60 °C, and showed enhanced T1/2 of 2.5 h at 70 °C in comparison to the wild type (1.3 h). EstM160K was successfully expressed Pichia pastoris and EstM160K fermentation broth was directly immobilized on epoxy-functionalized supports via a one-pot strategy to obtain the immobilized enzyme lx-EstM160K. Additionally, lx-EstM160K showed enhanced T1/2 of 36.8 h at 70 °C in comparison to free enzyme. lx-EstM160K could degrade various pyrethroid pesticides. After 40 min reaction with 50 U of the lx-EstM160K, the malathion removal was 95.8% with a malathion concentration of 20 mg/L. When 2.5 g lx-EstM160K was added to the 10 mL column reactor with the concentration of bifenthrin was 500 mg/L and the transfer rate of the pump was 0.7 mL/min, the degradation rate of lx-EstM160K to bifenthrin was 90.4%. lx-EstM160K exhibited high operational stability and maintained 72% initial activity after ten batches of continuous reaction for bifenthrin pesticide biodegradation.

Regioselective Acylation of Levoglucosan Catalyzed by Candida Antarctica (CaLB) Lipase Immobilized on Epoxy Resin

Every year, a large amount of residual agroindustrial waste has been generated and only around 10% is in fact reused. The development of new strategies for biomass valorization is important to add value to these commodities, since biomass is an excellent alternative feedstock to obtain chemicals of interest from renewable resources. The major compound of pyrolytic treatment of lignocellulosic biomass is levoglucosan (1,6-anhydroglucopyranose), an anhydro-sugar that can be transformed into glucose and is greatly valued in the most diverse industrial sectors as a surfactant, emulsifier, or even a lubricant. In this work, levoglucosan was acylated by lipase-catalyzed transesterification in acetonitrile with great conversions and selectivities with different acyl donors such as ethyl esters of lauric, palmitic, stearic, and oleic acids prepared in situ in an integrated strategy mediated by commercial lipases Novozym435 (N435), PSIM, and the home-made biocatalyst CaLB_epoxy. As a result, all biocatalyst generated mostly monoesters, with N435 being more selective to produce lauric esters (99% at 50°C) and PSIM to produce oleic esters (97% at 55 °C) while CaLB_epoxy was more selective to produce oleic esters of levoglucosan (83% at 55°C). This is the first report in the literature on the production of high selectivity levoglucosan esters.

A comprehensive review on staphylococcal protein A (SpA): Its production and applications

The Staphylococcus aureus protein A (SpA) can be obtained through the culture of wild-type S. aureus and also as a recombinant protein in safe bacterial hosts. Several methods have been used to purify SpA among which ion-exchange chromatography, affinity chromatography, gel filtration, and per aqueous liquid chromatography (PALC) are common. SpA has a wide range of biochemical, biotechnological, and medical applications and is most commonly used in test methods such as immunoprecipitation, enzyme-linked immunosorbent assay, and Western blotting. SpA has also been widely utilized in pharmaceutical applications to bind to immune complexes and serum immunoglobulins. SpA also directly binds to the B-cells preventing initiation of infectious diseases as well as having a role in the development of various autoimmune diseases. This review considers different applications of SpA in biotechnology and its novel clinical application for effective treatment of autoimmune diseases. It also discusses various strategies for expression and purification of the SpA including types of column chromatography that are commonly used in protein purification and developing SpA surface display technologies. Finally, this review highlights the potential and novel applications of SpA immobilization, SpA typing, protein engineering for further development of immunological and biochemical research, and also application of SpA as a diagnostic biosensor.

Influence of Dlutaraldehyde Cross-Linking Modes on the Recyclability of Immobilized Lipase B from Candida antarctica for Transesterification of Soy Bean Oil

Lipase B from Candida antarctica (CAL-B) is largely employed as a biocatalyst for hydrolysis, esterification, and transesterification reactions. CAL-B is a good model enzyme to study factors affecting the enzymatic structure, activity and/or stability after an immobilization process. In this study, we analyzed the immobilization of CAL-B enzyme on different magnetic nanoparticles, synthesized by the coprecipitation method inside inverse micelles made of zwitterionic surfactants, with distinct carbon chain length: 4 (ImS4), 10 (ImS10) and 18 (ImS18) carbons. Magnetic nanoparticles ImS4 and ImS10 were shown to cross-link to CAL-B enzyme via a Michael-type addition, whereas particles with ImS18 were bond via pyridine formation after glutaraldehyde cross-coupling. Interestingly, the Michael-type cross-linking generated less stable immobilized CAL-B, revealing the influence of a cross-linking mode on the resulting biocatalyst behavior. Curiously, a direct correlation between nanoparticle agglomerate sizes and CAL-B enzyme reuse stability was observed. Moreover, free CAL-B enzyme was not able to catalyze transesterification due to the high methanol concentration; however, the immobilized CAL-B enzyme reached yields from 79.7 to 90% at the same conditions. In addition, the transesterification of lipids isolated from oleaginous yeasts achieved 89% yield, which confirmed the potential of immobilized CAL-B enzyme in microbial production of biodiesel.

Lipase Immobilization on Silica Xerogel Treated with Protic Ionic Liquid and its Application in Biodiesel Production from Different Oils

Treated silica xerogel with protic ionic liquid (PIL) and bifunctional agents (glutaraldehyde and epichlorohydrin) is a novel support strategy used in the effective immobilization of lipase from Burkholderia cepacia (LBC) by covalent binding. As biocatalysts with the highest activity recovery yields, LBC immobilized by covalent binding with epichlorohydrin without (203%) and with PIL (250%), was assessed by the following the hydrolysis reaction of olive oil and characterized biochemically (Michaelis⁻Menten constant, optimum pH and temperature, and operational stability). Further, the potential transesterification activity for three substrates: sunflower, soybean, and colza oils, was also determined, achieving a conversion of ethyl esters between 70 and 98%. The supports and the immobilized lipase systems were characterized using Fourier transform infrared spectra (FTIR), scanning electron microscopy (SEM), elemental analysis, and thermogravimetric (TG) analysis.

Design of epoxy-functionalized Fe3O4@MCM-41 core-shell nanoparticles for enzyme immobilization

The scope of our research was to prepare the organosilane-modified Fe₃O₄@MCM-41 core-shell magnetic nanoparticles, used for L-ASNase immobilization and explored screening of immobilization conditions such as pH, temperature, thermal stability, kinetic parameters, reusability and storage stability. In this content, Fe₃O₄ core-shell magnetic nanoparticles were prepared via co-precipitation method and coated with MCM-41. Then, Fe₃O₄@MCM-41 magnetic nanoparticles were functionalized by (3-glycidyloxypropyl) trimethoxysilane (GPTMS) as an organosilane compound. Subsequently, L-ASNase was covalently immobilized on epoxy-functionalized Fe₃O₄@MCM-41 magnetic nanoparticles. The immobilized L-ASNase had greater activity at high pH and temperature values. It also maintained >92% of the initial activity after incubation at 55 °C for 3 h. Regarding kinetic values, immobilized L-ASNase showed a higher Vmax and lower Km compared to native L-ASNase. In addition, it displayed excellent reusability for 12 successive cycles. After 30 days of storage at 4 °C and 25 °C, immobilized L-ASNase retained 54% and 26% of its initial activities while native L-ASNase lost about 68% and 84% of its initial activity, respectively. As a result, the immobilization of L-ASNase onto magnetic nanoparticles may provide an advantage in terms of removal of L-ASNase from reaction media.

Influence of the reaction conditions on the enzyme catalyzed transesterification of castor oil: A possible step in biodiesel production

The identification of the influence of the reaction parameters is of paramount importance when defining a process design. In this work, non-edible castor oil was reacted with methanol to produce a possible component for biodiesel blends, using liquid enzymes as the catalyst. Temperature, alcohol-to-oil molar ratio, enzyme and added water contents were the reaction parameters evaluated in the transesterification reactions. The optimal conditions, giving the optimal final FAME yield and FFA content in the methyl ester-phase was identified. At 35°C, 6.0 methanol-to-oil molar ratio, 5wt% of enzyme and 5wt% of water contents, 94% of FAME yield and 6.1% of FFA in the final composition were obtained. The investigation was completed with the analysis of the component profiles, showing that at least 8h are necessary to reach a satisfactory FAME yield together with a minor FFA content.

Dopamine-functionalized mesoporous onion-like silica as a new matrix for immobilization of lipase Candida sp. 99-125

Dopmine functionalized mesoporous onion-like silica (DPMS) was synthesized via a biomimetic coating, and lipase Candida sp. 99-125 (LCS) was immobilized in DPMS (LCS@DPMS) by physical adsorption in this study. The DPMS was characterized by SEM, TEM, BET and FT-IR, and it was shown that the DPMS had clear multishell structures with large surface area of 419 m2/g. The activity, pH stability, thermal stability, storage stability, and reusability of the LCS@DPMS were investigated in detail. The stabilities of LCS@DPMS were improved significantly compared to the free lipase and LCS@MS (LCS immobilized in unfunctionalized mesoporous onion-like silica by physical adsorption). All the results indicated that the DPMS had high efficiency and improved stability for lipase immobilization.

One-step purification and oriented attachment of protein A on silica and graphene oxide nanoparticles using sortase-mediated immobilization

One-step purification and oriented immobilization of protein A on functionalized carriers.