Reuse Of Biocatalyst Research Articles

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

Immobilization of enzymes on suitable supports is a critical approach for enhancing enzyme stability, reusability, and overall catalytic efficiency. This study explores the immobilization of Candida rugosa lipase on zirconium-based 2-methylimidazole (ZrMI) nanoparticles, aiming to develop a stable and reusable biocatalyst. The ZrMI was produced via a solvothermal technique and analyzed using various characterization methods. Candida rugose lipase was immobilized using cross-linking agents, achieving an 87 % immobilization efficiency. The immobilized enzyme exhibited significantly enhanced thermal stability, broader pH tolerance, and increased catalytic efficiency compared to free C. rugose lipase. The ZrMI@lipase retained 69 % of its enzymatic activity following a 60-day storage period at 4 °C. Notably, it displayed significant reusability, maintaining 65 % of its original activity after undergoing 15 catalytic cycles. Examination of the kinetics revealed that the immobilized enzyme possessed a heightened substrate affinity (Km of 4.1 mM) and maximal reaction rate (Vmax of 85.7 μmol/ml/min) in comparison to the free enzyme (Km of 5.4 mM and Vmax of 69 μmol/ml/min), indicating enhanced catalytic efficiency. Validation through zeta potential and hydrodynamic size assessments verified the successful binding of the enzyme and the consistent colloidal characteristics. These results suggest that ZrMI is a promising support for C. rugose lipase immobilization, offering improved stability and reusability for various industrial applications. The study highlights the potential of ZrMI@lipase as an efficient and durable biocatalyst, contributing to advancements in enzyme immobilization technology and sustainable industrial processes.

Enhancement of thermostability and expression level of Rasamsonia emersonii lipase in Pichia pastoris and its application in biodiesel production in a continuous flow reactor

The acidic lipase from Rasamsonia emersonii named LIPR has great potential for biodiesel synthesis due to its strong methanol tolerance. Nonetheless, the limited thermostability of LIPR and low expression level in Escherichia coli remain major obstacles to its use in biodiesel synthesis. To enhance the thermostability, the mutant LIPR harboring mutations A126C-P238C for the formation of a new disulfide bond and amino acid substitution D214L was obtained through rational design. To our delight, the thermostability of LIPR mutant was greatly improved. Moreover, a comprehensive optimization strategy, such as employing the Mss signal peptide, co-expressing the molecular chaperone protein disulfide isomerase (PDI), knocking out the vacuolar sorting receptor gene VPS10-01, and overexpressing the dihydroxyacetone synthase gene DAS2, was adopted to obtain the combination-optimized mutant Pichia pastoris strain GS54. Furthermore, the biodiesel synthetic capability with the mutant GS54-LIPR was verified and the production yield was 52.2 % after 24 h in a shake flask. Subsequently, a continuous flow system was adopted to increase the biodiesel yield to 73.6 % within 3 h, demonstrating its efficacy in enhancing enzyme biocatalysis. The engineered GS54-LIPR mutant lipase is an efficient and reusable biocatalyst for the sustained production of biodiesel in a continuous flow reaction.

Enzyme immobilization with nanomaterials for hydrolysis of lignocellulosic biomass: Challenges and future Perspectives

Enzyme immobilization has emerged as a prodigious strategy in the enzymatic hydrolysis of lignocellulosic biomass (LCB) promising enhanced efficacy and stability of the enzymes. Further, enzyme immobilization on magnetic nanoparticles (MNPs) facilitates the easy recovery and reuse of biocatalysts. This results in the development of a nanobiocatalytic system, that serves as an eco-friendly and inexpensive LCB deconstruction approach. This review provides an overview of nanomaterials used for immobilization with special emphasis on the nanomaterial-enzyme interactions and strategies of immobilization. After the succinct outline of the immobilization procedures and supporting materials, a comprehensive assessment of the catalysis enabled by nanomaterial-immobilized biocatalysts for the conversion and degradation of lignocellulosic biomasses is provided by gathering state-of-the-art examples. The challenges and future directions associated with this technique providing a potential solution in the present article. Insight on the recent advancements in the process of nanomaterial-based immobilization for the hydrolysis of lignocellulosic biomass has also been highlighted in the article.

Opting for polyamines with specific structural traits as a strategy to boost performance of enzymatic membrane reactors

Enzymatic membrane reactor (EMR) is a type of continuous-flow bioreactor offering easy separation and reuse of biocatalyst while giving opportunities to improve its performance. However, simultaneous enhancement of activity and stability of enzyme while retaining high membrane permeability poses a challenge for a single reactor. Herein, we propose a new method to optimize EMR system − by employing cationic polyelectrolytes with selected molecular weight, backbone, and amino group type for modification of membrane surface; after we have evaluated the effect of polyamine chemistry and membrane properties on each aspect of EMR performance. Polydopamine (PDA)-assisted co-deposition of polyamines (polyethyleneimine (PEI), PEI-graft-poly(ethylene glycol) (PEI-g-PEG), poly(allylamine hydrochloride) (PAH), and poly(diallyldimethylammonium chloride) (PDADMAC)) was used as the modification method; the membranes were characterized by water permeability, water contact angle (WCA), zeta potential (ZP), FTIR spectra, and SEM/EDX; and EMRs were assessed by biocatalytic activity at various pH, flux, immobilization yield and efficiency (activity recovery), enzyme leakage, pH/storage and thermal stability, and reusability. In this work, EMRs with immobilized alcohol dehydrogenase (ADH) showed activities up to 8.9 mU/cm2, retained up to 86 % of initial activity in three conversion cycles without any reduction in flux, and allowed to increase non-optimal pH activity (pH 10) by up to 81 % and improve storage stability by up to 53 % compared to the free enzyme. We discovered statistically significant (p < 0.01) relationships between: (1) polyamine backbone type (linear vs branched) and membrane permeability; (2) membrane isoelectric point and immobilization yield; and (3) membrane WCA and immobilization efficiency. To our knowledge, this is the first systematic study of the effect of polyelectrolyte chemistry on performance of immobilized enzyme − which showed the method’s strong potential for customizing properties and maximizing the productivity of EMRs.

Evaluation of the operational conditions of the glucose oxidase and catalase multienzymatic system through enzyme co-immobilization on amino hierarchical porous silica

Hexaric acids have attracted attention lately because they are platform chemicals for synthesizing pharmaceuticals. In particular, gluconic acid is one of the most studied because it is readily available in nature. In this work, operational conditions like temperature and pH were evaluated for the enzymatic production of gluconic acid. For this purpose, glucose oxidase (GOx) and catalase (CAT) were individually immobilized and co-immobilized using amino-silica as support. The catalytic performance of the enzymes both as separate biocatalysts (GOx or CAT) and as an enzymatic complex (GOx-CAT) was assessed in terms of enzymatic activity and stability at temperatures 45 °C and 50 °C and pH 6 to 8. The results show that CAT is a key enzyme for gluconic acid production as it prevents GOx from being inhibited by H2O2. However, CAT was found to be less stable than GOx. Therefore, different GOx to CAT enzymatic ratios were studied, and a ratio of 1–3 was determined to be the best. The highest glucose conversion conditions were 45 °C and pH 7.0 for 24 h. Regarding the biocatalyst reuse, GOx-CAT retained more than 70% of its activity after 6 reaction cycles. These results contribute to further knowledge and application of oxidases for hexaric acid production and shed greater light on the role of the glucose oxidase/catalase pair in better catalytic performance. Both enzymes were immobilized in one pot, which is relevant for their potential use in industry; an enzyme system was obtained in a single step.

Exploring Strategic Approaches for CvFAP Photodecarboxylation through Violet Light Irradiation

In this study, we describe a light-driven photocatalytic decarboxylation of palmitic acid and related fatty acids using Chlorella variabilis fatty acid photodecarboxylase (CvFAP). By utilizing violet light emitting diode (LED) light (50 W; 397 nm), we achieved a remarkable conversion efficiency of 99% within just 4 min, surpassing the previous 79% conversion achieved in 60 min using blue LED light (300 W; 439 nm). Importantly, the use of 50 W violet LED light also resulted in a lower enzyme photoinactivation rate when compared to 300 W blue LED. Comparing the whole-cell biocatalyst with the enzymatic extract, we found that the former demonstrated superior catalytic performance and reduced susceptibility to photoinactivation. Furthermore, whole-cell biocatalyst reuse was demonstrated after five sequential batches. Employing this approach, we successfully synthesized 26 mmol L-1 h-1 of pentadecane, showcasing a promising strategy to improve productivity. These findings represent a significant advancement in CvFAP photodecarboxylation processes compared to the literature, utilizing an alternative light source, with potential implications to the biofuel sector

Adsorption immobilization of enzymes on alginates: properties and use of drugs based on them. Short review

Despite the widespread use of enzymes in various industries, primarily in food industry, leather, pharmaceuticals, cosmetology and biomedicine, their low stability and lack of reusability limit their use. Immobilization of enzymes, i.e. limitation of the degrees of freedom of their molecules by fixing them on some carrier can help overcome these limitations. However, interactions with the support and immobilization technique can affect the catalytic ability of enzymes. In this study, we briefly summarized the information on methods for immobilizing enzymes on alginic acid and its derivatives and focused on adsorption immobilization and the use of such enzyme preparations immobilized on alginates. Alginic acid is an unbranched heterogeneous copolymer consisting of 1,4-linked β-D-mannuronic acid and α-L-guluronic acid residues. Immobilization of enzymes on alginates often improves their stability and allows the reuse of biocatalysts. The adsorption of enzymes on alginic acid matrices and its derivatives is an effective process in terms of immobilization yield, i.e. the proportion of protein adsorbed on the carrier often exceeds 50%. Availability, biocompatibility, resistance to microbial contamination, non-toxicity and low cost make this polysaccharide a promising candidate for use as an enzyme carrier. In addition, the intrinsic biological activity of alginic acid makes it promising as a component for the creation of biocatalysts for medical or food purposes. Composites obtained from natural alginate by and their combination with other materials, both organic and inorganic, open up many new applications for immobilized enzymes. The study examines the possibilities of using enzymes immobilized on alginate or composites, widely used in the food industry. The final part of the article presents the main conclusions and also discusses the limitations of the industrial application of alginate carriers and possible ways to solve them.

Continuous biocatalytic production of trehalose in a fixed-bed bioreactor using immobilized trehalose synthase from Pseudomonas stutzeri

The integrated approach of biocatalytic conversion coupled with purification using selective enzyme was developed to achieve continuous trehalose production. The activity of trehalose synthase (TS) derived from three different bacteria—Deinococcus radiodurans, Pseudomonas stutzeri, and Thermus thermophillus—immobilized with chitin-binding domain (ChBD-DrTS, ChBD-PsTS, and ChBD-TtTS, respectively) was compared for the production of trehalose from maltose syrup. The trehalose production yield using ChBD-PsTS was 2.4 and 1.7-fold higher than those using ChBD-DrTS and ChBD-TtTS, respectively, after 24 h at 30 °C and pH 7.0. In this study, a continuous bioconversion system was developed for trehalose production using ChBD-PsTS in a fixed-bed bioreactor, resulting in an approximate yield of 72%, and a productivity of 4 g/L/h. Additionally, residual maltose was converted into glucose using glucoamylase, and the 37% of bioethanol was produced. The integrated approach demonstrated remarkable biocatalytic performance, biocatalyst reusability, and high production yield.

Food wastes clean water wastes: melon peel peroxidase isolation and immobilization onto magnetite nanoparticles for phenol removal

In this study, melon peel waste was utilized to isolate peroxidase enzyme through three-phase portioning (TPP) and subsequently immobilized onto magnetite nanoparticles for effective bioremediation of phenol pollutants from water. The optimization of TPP parameters ensured maximum activity recovery and enzyme purity. Magnetite nanoparticles were synthesized and used as a substrate for immobilizing the isolated peroxidase, achieving an activity recovery of 157% and a purification fold of 5.2. Protein homogeneity testing confirmed the purity of the peroxidase enzyme. The magnetite nanoparticles had an average diameter of 62 nm, and the immobilization efficiency reached 93% at pH 8 with an enzyme/nanoparticles v/v ratio of 1:9. The immobilized peroxidase demonstrated the ability to degrade 57% of phenol within 3 h and retained 30% relative activity even after five catalytic cycles. This immobilized melon peel peroxidase on magnetite nanoparticles proves to be a robust, enduring, and reusable biocatalyst with potential for various applications, especially in bioremediation processes.Graphical

Efficient valorization of food waste oils to renewable biodiesel by a Candida antarctica lipase B mutant that catalyzes the ester synthesis reaction in the presence of water

Food waste oil (FWO) is the most suitable raw material for economic biodiesel (BD) production, owing to its low price, sufficient supply, and waste disposal diversion. However, water in FWO inhibits BD production by Candida antarctica lipase B (CALB) which must be overcome. Here, a mutant lipase CALB1422 that catalyzes the ester synthesis in the presence of water was developed. The CALB1422 showed 91.1 % and 72.6 % BD conversion rates for soybean oil containing 2 % and 8 % water, respectively; wild-type CALB was inhibited to 29.8 % in the presence of 2 % water. It is presumed that the water attraction of the mutation site freed the catalytic site from water, which was confirmed by molecular dynamics simulation. From crude FWOs, the CALB1422 exhibited up to a 2.1-fold increased BD conversion yield against commercial lipase (Novozym 435). The mutant lipase is an efficient and reusable biocatalyst to produce sustainable BD from waste oils.

Microwave-assisted enzymatic synthesis of geraniol esters in solvent-free systems: optimization of the reaction parameters, purification and characterization of the products, and biocatalyst reuse

Various geraniol esters act as insect pheromones and display pharmacological activities, especially as neuroprotective agents. Therefore, the search for synthetic strategies alternative to traditional chemical synthesis could help designing ecofriendly routes for the preparation of such bioactive compounds. Hence, this work aims at the microwave-assisted enzymatic synthesis of geranyl esters in solvent-free systems. The process variables were optimized for the synthesis of geranyl acetoacetate, achieving 85% conversion after 60 min using a 1:5 substrates molar ratio (ester to geraniol), 80 °C and 8.4% of Lipozyme 435 lipase without removal of the co-produced methanol. On the other hand, a 95% conversion was reached after 30 min using 1:6 substrates molar ratio, 70 °C and 7% lipase in the presence of 5Å molecular sieves for the methanol capture. In addition, the lipase showed good reusability, maintaining the same activity for five reaction cycles. Finally, under the above optimized conditions, other geraniol esters were successfully synthetized such as the geranyl butyrate (98%), geranyl hexanoate (99%), geranyl octanoate (98%), and geranyl (R)-3-hydroxybutyrate (56%). These results demonstrate the microwave-assisted lipase-catalyzed transesterification in a solvent-free system as an excellent and sustainable catalytic methodology to produce geraniol esters.Graphical

Bacteria-Polymer Composite Material for Glycerol Valorization.

Bacterial immobilization is regarded as an enabling technology to improve the stability and reusability of biocatalysts. Natural polymers are often used as immobilization matrices but present certain drawbacks, such as biocatalyst leakage and loss of physical integrity upon utilization in bioprocesses. Herein, we prepared a hybrid polymeric matrix that included silica nanoparticles for the unprecedented immobilization of the industrially relevant Gluconobacter frateurii (Gfr). This biocatalyst can valorize glycerol, an abundant by-product of the biodiesel industry, into glyceric acid (GA) and dihydroxyacetone (DHA). Different concentrations of siliceous nanosized materials, such as biomimetic Si nanoparticles (SiNps) and montmorillonite (MT), were added to alginate. These hybrid materials were significantly more resistant by texture analysis and presented a more compact structure as seen by scanning electron microscopy. The preparation including 4% alginate with 4% SiNps proved to be the most resistant material, with a homogeneous distribution of the biocatalyst in the beads as seen by confocal microscopy using a fluorescent mutant of Gfr. It produced the highest amounts of GA and DHA and could be reused for up to eight consecutive 24 h reactions with no loss of physical integrity and negligible bacterial leakage. Overall, our results indicate a new approach to generating biocatalysts using hybrid biopolymer supports.

Encapsulated laccase in bimetallic Cu/Zn ZIFs as stable and reusable biocatalyst for decolorization of dye wastewater

Laccase have received extensive attention in pollutant degradation, but its practical viability is largely affected by the poor stability, easy inactivation and difficulty in recycling for the present. Enzyme immobilization offers enhanced enzyme stability and constructs a synergistic system for the efficient adsorption and degradation of pollutants. In this study, bimetallic Cu/Zn ZIFs were synthesized by co-precipitation method as the protective carrier for laccase. Lac@Cu-ZIF-90 exhibited a good protective effect on laccase and showed a high operational stability in various interfering environments. Free laccase was completely inactivated at pH 7.0 but Lac@Cu-ZIF-90 could maintain 50.0 % activity. Benefiting from the encapsulation of laccase and porous structure of Cu-ZIF-90, the Lac@Cu-ZIF-90 exhibited decolorization efficiency for dye wastewater. More importantly, the Lac@Cu-ZIF-90 could be recovered from the dye solution and re-used to adsorb and degrade the synthetic dye for multiple times, its removal rate for reactive deep green was only decreased about 10.8 % after five cycles. This work reveals that the Cu-ZIF-90 provides a favorable environment for laccase and as a protective layer to relieve the conformation change, which provides an efficient strategy to decolorize dye wastewater. Therefore, Cu-ZIF-90 promises applications as enzymes encapsulation has great potential in water remediation.

Synthesis of organic-inorganic hybrid nanoflowers of lipases from Candida antarctica type B (CALB) and Thermomyces lanuginosus (TLL): Improvement of thermal stability and reusability

Enzyme immobilization is used to improve the application of enzymes, allowing the reuse of biocatalysts and increasing their stability under reaction conditions. Immobilization of enzymes through structures, such as nanoflowers, is an innovative, simple, and low-cost method compared to other techniques. In this context, the main objective of this work is to synthesize hybrid biocatalytic nanostructures, similar to flowers, of lipases from Candida antarctica type B (CALB) and Thermomyces lanuginosus (TLL). The production of nanoflowers occurred by precipitation of lipases with CuCl2 or CuSO4 salts for 72 h. However, challenges and obstacles were faced in obtaining effective and practical nanoflowers, such as nanoflowers’ low thermal stability and reusability. To overcome these challenges, two conditions were tested: nanoflowers cross-linked with glutaraldehyde and nanoflowers and nanoparticles cross-linked with glutaraldehyde. This last biocatalyst prepared by CuSO4 precipitation showed better thermal stability (half-life about 230 and 233 min for CALB and TLL, respectively, under incubation at 60 °C and pH 7). The CALB biocatalyst retained 70 % of its initial activity (2.31 U) after 10 cycles of hydrolysis. Therefore, this work shows not only the problems and barriers of nanoflowers synthesis, but also the possibility of producing more stable and efficient biocatalysts using improved protocols.

Saccharomyces cerevisiae Catalyzed Synthesis and Evaluation of Pyrazoles

Abstract: Background: Biocatalysis in organic solvents has several benefits over aqueous solvents, including solubility of organic substrates, ease of workup, separation of the product, and, in certain cases, reusability of biocatalysts. Materials and Methods: A simple, effective, and environmentally friendly technique for synthesizing pyrazoles has been established, which involves the cyclo condensation of chalcones and isonicotinic acid hydrazide in organic solvents using a relatively inexpensive catalyst baker’s yeast (Saccharomyces cerevisiae). Molecular properties prediction and docking studies were also performed. Results: The predicted molecular properties suggest that the molecules are safe for oral consumption and their docking studies on 2BVC-Mycobacterium tuberculosis glutamine synthetase show their favorable ligand binding nature. The structural assignments were validated based on spectrum data. The compounds were evaluated for their antitubercular, in vitro anti-inflammatory, and anti-oxidant effects. The analysis reveals that synthesized derivatives of pyrazoles possessing methoxy, nitro, hydroxyl, fluoro, and chloro substitution through the phenyl ring help the molecule to increase its pharmacological activities. However, the substituted thiophene ring in the side chain also facilitates the biological action of the molecules. Conclusion: Anti-inflammatory, anti-oxidant, and anti-tubercular properties are due to the presence of the pyrazole ring. Keywords: Pyrazoles, Chalcones, Saccharomyces cerevisiae, In vitro Anti-inflammatory, Antioxidant, Anti-tubercular.

Coimmobilized enzymes as versatile biocatalytic tools for biomass valorization and remediation of environmental contaminants - A review

Due to stringent regulatory norms, waste processing faces confrontations and challenges in adapting technology for effective management through a convenient and economical system. At the global level, attempts are underway to achieve a green and sustainable treatment for the valorization of lignocellulosic biomass as well as organic contaminants in wastewater. Enzymatic treatment in the environmental aspect thrived on being the promising rapid strategy that appeased the aforementioned predicament. On that account, coimmobilization of various enzymes on single support enhances the catalytic activity ensuing operational stability with industrial applications. This review pivoted towards the coimmobilization of enzymes on diverse supports and their applications in biomass conversion to industrial value-added products and removal of contaminants in wastewater. The limelight of this study chronicles the unique breakthroughs in biotechnology for the production of reusable biocatalysts, which inculcating various enzymes towards the scope of environment application.

Lactate dehydrogenase encapsulated in a metal-organic framework: A novel stable and reusable biocatalyst for the synthesis of D-phenyllactic acid

In this study, we synthesized a novel biocatalyst by encapsulating lactate dehydrogenase (LDH) in the metal-organic framework ZIF-90 by one-pot embedding. It showed strong biological activity for efficient synthesis of D-phenyllactic acid (D-PLA). The morphology and structure of LDH@ZIF-90 was systematically characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy, confocal laser scanning microscopy (CLSM) and gas sorption. According to thermogravimetric analysis (TGA), the enzyme loading of the biocatalyst was 3 %. The Michaelis–Menten constant (Km) and maximal reaction rate (Vmax) of LDH@ZIF-90 were similar to those of free LDH, which proved that ZIF-90 had good biocompatibility to encapsulate LDH. At the same time, LDH@ZIF-90 exhibited enhanced tolerance to temperature, pH and organic solvents, and its reusability was greatly improved with 68 % of initial enzyme activity remaining after 7 rounds of recylcing. Overall, LDH encapsulated in ZIF-90 may be an economically competitive and environmentally friendly novel biocatalyst for the synthesis of D-PLA.

Degradation of novel mineral flotation reagent 8-hydroxyquinoline by superparamagnetic immobilized laccase: Effect, mechanism and toxicity evaluation

• The effect of main constituents of MPW on 8-HQ degradation was evaluated. • Favorable 8-HQ degradation efficiency was achieved in real lead–zinc mine water. • The biocatalyst exhibited efficient recyclability and reusability. • Degradation predominantly generated various structural 8-HQ oligomers/polymers. • TOC and toxicity were effectively reduced with the degradation of 8-HQ. The environmental impact of the mining industry requires efficient and eco-friendly technologies to mitigate the presence of mineral flotation reagents (MFRs) in mineral processing wastewater (MPW) prior to their discharge into the environment. In this work, for the first time, a robust, easily separable and reusable biocatalyst, Fe 3 O 4 @SiO 2 -NH 2 -Lac, was used for the degradation of a novel mineral flotation reagent 8-hydroxyquinoline (8-HQ). Under optimized conditions, Fe 3 O 4 @SiO 2 -NH 2 -Lac achieved 89.2% 8-HQ degradation efficiency within 6 h. The effect of the main constituents of MPW on 8-HQ degradation, including metal ions, organic solvents, surfactant, metal chelator and flotation frother was evaluated. The Fe 3 O 4 @SiO 2 -NH 2 -Lac also displayed favorable degradation efficiency of 8-HQ in real lead–zinc mine water. The biocatalyst could be easily recovered and had a satisfactory reusability, retaining 64.5% of 8-HQ degradation efficiency in the sixth reaction cycle. Identification of intermediate products revealed that Fe 3 O 4 @SiO 2 -NH 2 -Lac mediated reaction predominantly generated various structural 8-HQ oligomers/polymers. A potential degradation pathway for 8-HQ was speculated as follows: Fe 3 O 4 @SiO 2 -NH 2 -Lac initially catalyzed the oxidation of 8-HQ to yield the corresponding reactive radical intermediates, which subsequently undergone self-coupling reaction via C − C and C − O − C covalent coupling at their ortho and/or para positions, finally forming oligomers and polymers. The inhibition assays of marine bacterium ( Vibrio fischeri ) demonstrated that the toxicity of 8-HQ and its intermediate products was effectively reduced after Fe 3 O 4 @SiO 2 -NH 2 -Lac treatment. The results of this study might present an alternative immobilized laccase-based clean biotechnology for the clean-up and detoxification of 8-HQ contaminated MPW.

First biocatalytic synthesis of piperidine derivatives via an immobilized lipase-catalyzed multicomponent reaction

A robust and reusable biocatalyst was constructed via immobilization of lipase onto magnetic halloysite nanotubes for the synthesis of piperidine derivatives.

Design of functional glycerol-based deep eutectic solvents as reaction media for enzymatic deacidification of high-acid rice bran oil

The effectiveness of deacidification technologies for high-acid rice bran oil (HRBO) are still one of the main challenges in the industrialization process of rice bran oil (RBO). A novel function of glycerol-based deep eutectic solvents (DESs) as an acyl acceptor in combination with lipases for enzymatic esterification of deacidification of HRBO was described in this study. The maximum deacidification efficiency of 92.38% was obtained under the optimized reaction conditions. Molecular docking simulation indicated that the minimum binding energy of Novozym 435 was lower than those of Lipozyme TL IM and Lipozyme RM IM, which might be one of the underlying mechanisms for its better performance. Additionally, γ-oryzanols, tocopherols and tocotrienols were retained in deacidified RBO. We are convinced that the reusability of biocatalyst and DESs systems provide an alternative strategy to design a facile, environmentally-friendliness DESs towards economic feasibility of applications and processes for oil-refined industries.