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Biodiesel, a third-generation biofuel, offers several advantages over regular diesel fuel. Waste cooking oil (WCO) emerges as an ideal feedstock due to its availability and easy accessibility. In this work, biodiesel was produced from two different types of immobilized lipases: Rhizomucor miehei lipase (RMIM) and Candida antarctica lipase B (CALB). The objective of this study was to evaluate the impact of the molar ratio of WCO to methyl acetate, toward biodiesel yield and triacetin formation, from transesterification reaction when using two different immobilized lipases namely, Rhizomucor miehei lipase (RMIM) and Candida antarctica lipase B (CALB) as catalyst, as well as to assess its resulting biodiesel in a diesel engine. The enzymatic transesterification reaction was carried out with ultrasonic assistance, and the results showed that the greatest yield of 81.20% was achieved at 45 °C using CALB as a biocatalyst, with a lipase concentration of 1.8% (w/v) and an oil to methyl acetate molar ratio of 1:12 within 3 h. Triacetin, a by-product was determined their concentration for each molar ratio and analyzed using FTIR range of 500 cm-1 to 4000 cm-1, revealing a significant absorption peak at 1238.90 cm-1. Biodiesel was then blended with commercial diesel fuel in varying quantities of 7, 10, and 20% by volume (B20). The results were compared to Industrial Diesel Fuel 7% (B7) and Commercial Diesel Fuel 10% (B10). NOx and CO2 emission drops as the percentage of diesel/biodiesel blends increases, supporting WCO as a cost-effective biodiesel feedstock with low petrol pollution. [ABSTRACT FROM AUTHOR]

Biodiesel, a third-generation bio-fuels, offering several advantages over regular diesel fuel. Waste cooking oil (WCO) emerges as an ideal feedstock due to its availability and easy accessibility. In this work, biodiesel is utilized from two different types of immobilized lipases: Rhizomucor miehei lipase (RMIM) and Candida antarctica lipase B (CALB). The impact of the molar ratio of oil to methyl acetate (1:3-1:12) was evaluated for both lipases, and the resultant biodiesel was tested in diesel engine. The enzymatic transesterification was carried out in ultrasonic assistance and the results showed that the greatest yield of 81.20% at 45℃, using CALB as a biocatalyst, 1.8% (w/v) lipase and oil to methyl acetate molar ratio of 1:12 within 3 hours. Triacetin, by-product was determined their concentration for each molar ratio and analyzed using FTIR range of 500cm-1 to 4000cm-1, revealing a significant absorption peak at 1238.90cm-1. Biodiesel was blended with commercial diesel fuel in varying quantities of 7, 10, and 20% by volume (B20). The results were compared to Industrial Diesel Fuel 7% (B7) and Commercial Diesel Fuel 10% (B10). NOx and CO2 emission drops as the percentage of diesel/biodiesel blends increases, supporting WCO as a cost-effective biodiesel feedstock with low petrol pollution.

In this study, hybrid skeleton material ZIF-8@ZIF-67 was synthesized by the epitaxial growth method and then was utilized as a carrier for encapsulating Pseudomonas fluorescens lipase (PFL) through the co-precipitation method, resulting in the preparation of immobilized lipase (PFL@ZIF-8@ZIF-67). Subsequently, it was further treated with glutaraldehyde to improve protein immobilization yield. Under optimal immobilization conditions, the specific hydrolytic activity of PFL@ZIF-8@ZIF-67 was 20.4 times higher than that of the free PFL. The prepared biocatalyst was characterized and analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared (FT-IR). Additionally, the thermal stability of PFL@ZIF-8@ZIF-67 at 50 °C was significantly improved compared to the free PFL. After 7 weeks at room temperature, PFL@ZIF-8@ZIF-67 retained 78% of the transesterification activity, while the free enzyme was only 29%. Finally, PFL@ZIF-8@ZIF-67 was applied to the neryl acetate preparation in a solvent-free system, and the yield of neryl acetate reached 99% after 3 h of reaction. After 10 repetitions, the yields of neryl acetate catalyzed by PFL@ZIF-8@ZIF-67 and the free PFL were 80% and 43%, respectively. [ABSTRACT FROM AUTHOR]

The use of new materials in the field of biofuel production has been represented as a step in the development of remarkable catalysts. The use of lipases in the production of biodiesel is often seen as a cost-limiting step, as the operating expenses in recovering such catalysts can lead to unfeasible market expectations. In this study, hydroxyapatite (HAp) particles were evaluated as a support to immobilize commercial lipase, following application in ethyl ester synthesis. First, hydroxyapatite was synthesized through the co-precipitation method at constant pH and selected as a support to be used in enzyme immobilization. The characterization of the biocatalyst support materials produced was carried out using DRX, BET, FTIR, TGA, and SEM analysis. The lipase from Thermomyces lanuginosus was then immobilized in the matrices, and, subsequently, there was transesterification of the vegetable oil deodorization distillate (VODD). The biodiesel samples generated showed that they were within commercial standards, achieving ester conversion greater than 96.5%. Other properties such as density (0.87 g.cm−3) and viscosity (4.36 mm2.s−1) meet the specifications required by ASTM to be used as a biofuel. In the experiment planning technique, the results revealed an experimental trend and a defined behavior: a higher lipase loading in the immobilization and the use of temperatures in the range of 40–50 °C favor high conversions of ethyl esters. Thus, this confirms that the enzymatic chemical catalyst was able to form the main fatty acid esters even using a residual lipid raw material. [ABSTRACT FROM AUTHOR]

Purpose: Natural deep eutectic solvents (NADES) represent a green alternative to conventional organic solvents as reaction medium, offering more benign properties. To efficiently design NADES for biocatalysis, a better understanding of their effect on these reactions is needed. We hypothesize that this effect can be described by separately considering (1) the solvent interactions with the substrates, (2) the solvent viscosities and (3) the enzyme stability in NADES. Methods: We investigated the effect of substrate solvation and viscosity on the reaction rate; and the stability of the enzyme in NADES. To this end, we monitored the conversion over time of the transesterification of vinyl laurate with 1-butanol by the lipase enzyme Candida antarctica B in NADES of different compounds and molar ratios. Results: The initial reaction rate is higher in most NADES (varying between 1.14 and 15.07 μ m o l m i n - 1 m g - 1 ) than in the reference n-hexane (4.0 μ m o l m i n - 1 m g - 1 )), but no clear relationship between viscosity and initial reaction rate was found. The increased reaction rate is most likely related to the solvation of the substrate due to a change in the activation energy of the reaction or a change in the conformation of the substrate. The enzyme retained part of its activity after the first 2 h of reaction (on average 20 % of the substrate reacted in the 2-24 h period). Enzyme incubation in ethylene glycol-based NADES resulted in a reduced reaction rate (15.07 vs. 3.34 μ m o l m i n - 1 m g - 1 ), but this may also be due to slow dissolution of the substrate. Conclusions: The effect of viscosity seems to be marginal next to the effect of solvation and possible enzyme-NADES interaction. The enzyme retains some of its activity during the 24-hour measurements, but the enzyme incubation experiments did not yield accurate, comparable values. [ABSTRACT FROM AUTHOR]

This study investigated the incorporation of nervonic acid into the chemical structure of phosphatidylcholine via a lipase-catalyzed acidolysis reaction to obtain a functional phospholipid. Lipase immobilization was conducted, and Amberlite XAD7-HP was selected as a carrier to immobilize phospholipase A1 (PLA1) for subsequent experiments. The main acidolysis reaction parameters, including enzyme load, substrate ratio, temperature, and water content, were studied against the reaction time. The optimum reaction conditions obtained were enzyme load, 20%; reaction temperature, 55 °C; water content, 1%; and reaction time, 9 h. The maximum incorporation of nervonic acid into phosphatidylcholine was 48 mol%, with PC recovery at 61.6 mol%. The positional distribution of structured phosphatidylcholine shows that nervonic acid was found in the sn-1 position due to enzyme specificity and in the sn-2 position, possibly due to acyl migration. [ABSTRACT FROM AUTHOR]

Due to the increasing demand for green processes in renewable energy production, the extracellular Bacillus subtilis B-1-4 lipase was used as a biocatalyst for producing biodiesel from waste cooking oil. Response surface methodology was employed for the optimization of enzyme production. Lipase activity was modeled with a quadratic function of four factors that primarily influence the culture medium. Thanks to this model, an optimal lipase activity of 1.7 ± 0.082 U/mL was achieved with the best culture medium composition: 16 g/L of tryptone, 15 g/L of yeast extract, 15 g/L of NaCl, and a 0.15 initial optical density at 600 nm (OD600 nm). The maximal lipase activity was measured at 45 °C and pH 8, using para-nitrophenyl palmitate as a substrate. The enzyme maintained above 94% and 99% of its initial activity at temperatures ranging from 40 to 50 °C and at pH 8, respectively. Moreover, it exhibited a higher residual activity than other Bacillus lipases in the presence of organic solvents. Residual activities of 86.7% and 90.2% were measured in the presence of isopropanol and ethanol, respectively. The lipase was immobilized by adsorption onto CaCO3 powder. FT-IR and SEM were used to characterize the surface-modified support. After immobilization, a lipase activity of 7.1 U/mg of CaCO3 was obtained. Under the optimized conditions, the highest biodiesel yield of 71% was obtained through the transesterification of waste cooking oil using the CaCO3-immobilized Bacillus subtilis lipase. This research reveals a method for the utilization of waste cooking oil for biodiesel production using an efficient immobilized thermostable lipase, providing environmental and economic security. [ABSTRACT FROM AUTHOR]

Background: Puerarin, a flavonoid abundantly found in the roots of Pueraria lobata, exhibits antioxidant, anti-cancer, anti-inflammatory, and anti-aging properties. Despite its numerous benefits, the low bioavailability of puerarin hinders its widespread industrial application. To improve this, flavonoid acylation is required. Lipase is a biocatalyst primarily used for flavonoid acylation; immobilized lipase is preferred given the limited stability of free lipase. Although research on flavonoid acylation for structural modification is actively being conducted, there is a need to explore continuous production for enhancing the industrial application of flavonoid esters. Therefore, in this study, we aimed to produce puerarin palmitate innovatively by selecting an effective lipase, developing an immobilized lipase, characterizing the enzymatic reaction, and designing a semi-continuous reactor system. Results: Lipase from Thermomyces lanuginosus (TL) was found to be the most suitable for the synthesis of puerarin palmitate; it was successfully immobilized on glutaraldehyde-activated silica gel (GASG). TL GASG showed greater solvent, thermal, and operational stability than those of commercial immobilized lipases. Furthermore, TL GASG use resulted in a puerarin palmitate conversion rate of 97.17% within 3 h. Additionally, the reusability of TL GASG for this reaction was higher than that of commercially available immobilized lipases. Upon using a semi-continuous reactor, the cumulative conversion rate of puerarin palmitate remained above 85% after more than ten substrate injections. Conclusions: The results support the feasibility of the continuous production of flavonoid esters, underscoring their diverse industrial applications. A biorefinery strategy is anticipated to be proposed to utilize P. lobata extract biomass for flavonoid ester production. Moreover, optimizing continuous reactors through statistical experimental design is expected to enhance flavonoid ester production efficiency; these aspects will be explored in future research. Highlights: The stability of TL GASG was higher than commercial immobilized lipases. The novel immobilized lipase was applied to puerarin ester synthesis. The maximum conversion of puerine palmitate was achieved 97.17% in 3 h. Conversion rate via semi‐continuous reaction was maintained > 85% after 10 injections. [ABSTRACT FROM AUTHOR]

Entrapped lipase derived from Candida rugosa can be used as an alternative for commercial heterogeneous catalysts in the biodiesel synthesis process. The inclination towards a recirculating reactor with lipase-containing beds stems from its capability to simultaneously improve both yield and reproducibility in the biodiesel synthesis process. To industrialize biodiesel production with entrapped lipase in a recirculating reactor, optimization is essential, and this can be estimated using a kinetics model. In this context, a kinetics model based on the Ping-Pong Bi-Bi mechanism was developed for enzyme transesterification. Following this, experiments on biodiesel synthesis were carried out in a fixed-bed reactor with a recirculated substrate, and a biodiesel concentration of 2177.231 mol/m3 was achieved from 917.804 mol/m3 triglyceride. In this study, 3 models, namely Model 1, 2, and 3, were developed based on the Ping-Pong Bi-Bi mechanism, and each has assumptions that determine its complexity. To validate these models, two sets of secondary data were taken and fitted into the respective model. The sum relative error is used to express the differences between model and experimental data. Model 1, predicting each component in transesterification, exhibited the highest error of 1.64, while Model 3, assuming excess alcohol and incorporating a pseudo-steady-state for di- and monoglyceride, yielded the lowest error. Despite these variations, every model demonstrated good agreement in following each component profile accurately, providing a more precise description of the reaction elements. [ABSTRACT FROM AUTHOR]

Lipase was immobilized onto agarose beads and used for enzyme-catalyzed hydrolysis/transesterification of castor oil at room temperature without surfactants and salts. The immobilization yield was evaluated by reacting p-nitrophenyl butyrate and immobilized lipase. The reaction was performed in a 25 mL phosphate buffer medium (pH 7.0) and incubated for 2 hours. The absorbance of the formed p-nitrophenol was measured at 346 nm. The highest immobilization rate was obtained using 5.0 mg lipase with 2.5 mL glyoxal agarose beads. The reaction was performed in 25.0 mL sodium bicarbonate buffer pH 10 for 12 h. The hydrolysis/transesterification of castor oil was performed in phosphate buffer (pH 7) – ethanol medium. The main products were ricinoleic acid and ethyl ricinoleate. The highest hydrolysis/transesterification yield was 87% using 1.0 g castor oil and 2.5 mL of lipase immobilized agarose beads in the phosphate buffer (pH 7): ethanol (1: 9, V: V) at 72 hours. The reaction products were analyzed using a Fourier Transform Infrared spectrometer (FTIR) and Reversed-Phase High-Performance Liquid Chromatography (RP-HPLC). [ABSTRACT FROM AUTHOR]

The conjugation of phytosterols (PSs) with fatty acids results in producing phytosterol esters (PSEs) characterized by enhanced lipophilicity and improved functional properties of major interest in food and nutraceutical applications. The use of immobilized lipases to catalyze direct transesterification reactions between PSs and plant oils to form PSEs as a green alternative to conventional chemical production methods has attracted interest during the last two decades. The low solubility of PSs in common plant oil triglycerides, typically below 3% at ambient temperatures, remains the main challenge for bringing lipase-catalyzed direct transesterification reactions of PSs and oil triglycerides to commercial scales. This study focuses on the enzymatic synthesis of PSEs starting from solubilized PSs at concentrations of up to 30% wt./wt. of oil mixtures comprising fatty acid ethyl esters (FAEEs), monoglycerides (MGs), diglycerides (DGs), and triglycerides (TGs) as a homogeneous medium for the direct transesterification reaction. The results of this study show for the first time that the addition of FAEEs into the reaction medium results in an alteration of the substrate preference of the enzyme, making MGs the favorite fatty acyl group donors for PSs amongst all other fatty acyl donors present in the reaction system. The proposed new enzymatic route allows starting with high concentrations of solubilized PSs, making the direct transesterification of oil glycerides attractive for the production of PSEs at industrial scales. [ABSTRACT FROM AUTHOR]

Currently, there exists a significant need for alternate sources of petroleum fuel due to escalating environmental challenges and diminishing global oil reserves. Biodiesel, an environmentally friendly and sustainable fuel, is one of the most adaptable alternatives to petroleum fuel. This study's goals were to get biodiesel from three oils (olive, palm, and jojoba) and see how well lipases work as biocatalysts for the esterification process. The production of biodiesel was obtained from two fungal strains, Aspergillus niger MH079049.1 and A. niger MH078571.1, and four distinct fatty acids and four organic solvents were used. The study determined the optimal reaction conditions to be a reaction time of 24 h, an enzyme concentration of 3 mL, and an oil-to-methanol ratio of 3:1. This study showed that lipase works well in making biodiesel, with an impressive esterification yield of 99%, and the highest level of productivity was attained when olive oil and jojoba oils were subjected to an incubation time of 18 h and 22 h, respectively, in the presence of palm oil. [ABSTRACT FROM AUTHOR]

Biodiesel is a green and renewable alternative energy source which can be produced through lipase‐catalyzed transesterification process. Enzymatic biodiesel production has generated much interest owing to its environmentally friendly process, low wastewater treatment requirements and easy product separation. In this work, we attempt to review some of the recent patents and state‐of‐the‐art technology in lipase‐catalyzed transesterification for biodiesel production including feedstock, lipases, novel carriers and process factors. This work will provide useful guidance for researchers to develop cost efficient process for production of biodiesels. [ABSTRACT FROM AUTHOR]

The demand for biodiesel worldwide is skyrocketing as the need to replace fossil diesel with renewable energy sources becomes increasingly pressing. In this context, biocatalysis is emerging as an environmentally friendly and highly efficient alternative to chemical catalysis. When combined with the utilization of waste materials, it has the potential to make the process of biodiesel production sustainable. In the study, the potential of an extract rich in lipase produced by an Amazonian endophytic fungus as a biocatalyst in the transesterification of waste cooking oil for biodiesel production has been systematically investigated. The fungus Endomelanconiopsis endophytica exhibited an enzyme production of 11,262 U/mL after 120 h of cultivation. The lipolytic extract demonstrated its highest catalytic activity at 40 °C and a pH of 5.5. Using soybean oil and frying residue as raw materials, biodiesel was produced through biocatalytic transesterification, and yields of 91% and 89% (wt.), respectively, were achieved. By evaluating the process parameters, a maximum biodiesel yield of 90% was achieved using ethanol at a ratio of 3:1 ratio within 120 min. The experimental results demonstrate the feasibility and sustainability of applying a fungal enzymatic extract as a biocatalyst in the production of ethyl esters using waste cooking oil as a raw material. [ABSTRACT FROM AUTHOR]

Lipases are preferred industrial enzymes because they catalyse synthesis reactions in organic media. The immobilisation process improves the stability and reusability of the lipases allowing its application as a catalyst in reactions of transesterification. A wide range of functional carriers have been used for the immobilisation of lipase. Polyvinyl alcohol (PVA), as a promising carrier, provides different characteristics and properties of biocatalysts, and importantly, allows interfacial activation of the lipase. In the present study, a transesterification reaction was performed on immobilised lipase on a polysiloxane-polyvinyl alcohol hybrid matrix (PVA-SiO2 ). As a result, the optimal reaction conditions were determined to be as follows: reaction time of 12 h, the concentration, and the type of acyl acceptor 1 mmol/l butyl acetate for the PVA-SiO2 immobilised lipase. The lipase immobilised on modified epoxy-SiO2 -PVA achieved maximum activity using 0.8 mmol/l methyl oleate. The influence of various organic solvents as a medium for the transesterification reaction was also investigated. Different solvents were found to have a significant effect on the lipase activity of the two modified supports. It was observed that PVA-SiO2 immobilised lipase exhibits excellent transesterification activity in the presence of a hydrophobic reaction medium. In contrast, epoxy SiO2 -PVA immobilised lipase prefers a hydrophilic environment. The operational stability was tested by repeated batch experiments, where transesterification activity was decreased by only 10% after the lipase was reused for 5 cycles. The results from this study highlight the reaction optimal conditions for transesterification activity and stability of the immobilised lipase from Rhizopus arrhizus. [ABSTRACT FROM AUTHOR]

BACKGROUND: Eicosapentaenoic acid (EPA) has been recognized as a promising nutrient to improve therapeutic efficacy for cancer patients. Nevertheless, there are certain limitations to the application of EPA due to its structural characteristics. To maximize the nutritive value of EPA, a type of medium‐ and long‐chain triacylglycerol (MLCT) enriched with EPA was designed and synthesized using the lipase‐catalyzed transesterification of medium‐chain triglyceride (MCT) and EPA‐enriched fish oil (FO). RESULTS: The optimum synthesis conditions for EPA‐enriched MLCT used Lipozyme RM as catalyst, and had a substrate mass ratio (MCT/EPA‐enriched FO) of 3:1, lipase loading of 80 g kg−1, a reaction temperature of 60 °C, and a reaction time of 6 h. The MLCT content was as high as 80.79% after the transesterification reaction and the purification, and the content of MLCT containing EPA accounted for 70.21%. The distribution of EPA at the sn‐2 position showed a significant increase in MLCT compared with the original substrate, from 18.89% to 26.93%. The in vitro digestion results demonstrated that MLCT had a significantly higher EPA bioaccessibility than the original substrate. CONCLUSION: Eicosapentaenoic acid‐enriched MLCT was developed. This may provide a novel strategy for clinical nutritional intervention. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Kinetic studies are necessary to identify inhibitors of lipase enzyme deactivation in reaction systems because varying substrate concentrations can affect the enzyme's catalytic activity. The present study aimed to analyze the reaction kinetics of palm-based polyol ester production catalyzed by commercial lipase Novozyme 435 (N435). The enzymatic transesterification reaction was performed in a solvent-free medium. The effect of substrates concentration, specifically high oleic palm methyl ester (HO-PME) and trimethylolpropane (TMP), on the kinetic constant was studied at the initial reaction rate. The study was conducted based on the Ping-pong Bi-bi model, assuming that both substrates could inhibit the reaction. The reaction was carried out at 70 °C and 15.25 mbar with a 3 % (w/w) N435 enzyme load to investigate the effect of various HO-PME and TMP concentrations. The kinetic constants obtained are as follows: K m (HOPME) = 61. 112 mol/L, K m (TMP) = 0.336 mol/L, K i (HOPME) = 0.002 mol/L, K i (TMP) = 2.415 mol/L and V max = 17.24 mol/L.hr. The results implied that N435 has higher affinity towards TMP than HO-PME. Inhibition constant indicated a lower inhibitory function of the TMP than HO-PME (K i (TMP) > K i (HOPME)). The reaction kinetics obtained in this study agreed well with the model used with TMP and HO-PME as competitive inhibitor during enzymatic transesterification. [Display omitted] • HO-PME and TMP concentrations affected the kinetic constant. • Lipase enzyme Novozymes 435 (N435) has a higher affinity for TMP than HO-PME. • Reaction kinetics agreed with the Ping-pong Bi-bi model as competitive inhibitors. [ABSTRACT FROM AUTHOR]

The increasing environmental and economic concerns regarding the use of fossil fuels have led to the exploration of alternative energy sources that are renewable, ecofriendly, economically viable, and sustainable, to meet the growing energy demand. Biodiesel is a promising alternative fuel that has similar properties to diesel and can replace conventional diesel. Biodiesel is synthesized using oil sources and can be produced through transesterification processes, which can be catalyzed by chemical catalysts like NaOH/KOH or enzymes such as lipase. Enzymatic transesterification is a promising process for biodiesel production over chemical transesterification. In this study, Honge oil was converted to FAME (fatty acid methyl ester) using locally prepared immobilized beads of lipase extracted from an isolated strain of bacteria, Lysinibacillus macroides FS1. A statistical design was used to evaluate the impact of effective variables such as the amount of immobilized lipase (%), pH, and agitation speed (rpm) on biodiesel yield. The results showed that these factors had a positive effect on biodiesel production, indicating that the model is highly significant at a 95% confidence level. The optimum factors were found to be an amount of immobilized lipase of 12.5%, pH of 7, agitation speed of 125rpm, molar ratio of 1:3, temperature of 45°C, and reaction time of 24 hours, which yielded 96% yield. The model yields of 96% under these optimum conditions with one-time addition of methanol indicate that the prepared immobilized lipase is methanol tolerant, which has the potential for costeffective large-scale production of biodiesel. [ABSTRACT FROM AUTHOR]

In this work, ultrasound was used to assist the ethanolysis of castor oil in a solvent‐free system, catalyzed by a dry fermented solid containing the lipase from Burkholderia contaminans (BCFS). Reactions were done at 45°C. The maximum conversion in Erlenmeyer flasks was 71% in 96 h, using a loading of 9% (mass of BCFS in relation to the mass of triacylglycerols in the castor oil) and a molar ratio of ethanol:oil of 6:1, with addition of ethanol in 12 steps. In a packed‐bed reactor containing 12 g of BCFS, the conversions were 78% in 48 h, and 83% in 72 h with an ethanol to oil molar ratio of 3:1 and treatment with an ultrasound probe, with maximum power of 500 W, frequency of 20 kHz, and 75% of the maximum power. These results are promising given that, with an ultrasound assisted bioreactor, a higher conversion in a shorter time was achieved, with a lower ethanol to oil molar ratio than was the case in the Erlenmeyer flasks without ultrasound. [ABSTRACT FROM AUTHOR]

An immobilized lipase with metal‐organic frameworks (MOFs) was first used for the kinetic resolution of mandelic acid enantiomers by transesterification reaction using vinyl acetate as acyl donor in organic medium. Notably, the biocompatibility of the carrier and catalytic performance of lipase could be significantly improved via modification of NH2‐Ni‐MOF with polyvinylpyrrolidone. After extensively screening the enzymatic process, the optimal enantioselective resolution conditions and excellent outcomes were obtained for the enzyme‐catalyzed transesterification reaction. In addition, the recovered immobilized lipase displayed outstanding reusability after immobilization. [ABSTRACT FROM AUTHOR]

A high-performance and scalable lipase immobilization method using a dipping and jet break-up technique was reported for the production of microcapsule biocatalysts with an entrapped cascade of lipase enzyme. The lipase from Candida antarctica (CALb) recombinant Aspergillus oryzae and from the vegetal of Jatropha curcas L. (var. Sevangel) in Morelos State of Mexico were entrapped by mixing with a sodium alginate biopolymer at different concentrations. The obtained microcapsules were hardened in a CaCl2 solution, aiming at developing Ca2+ alginate microbeads with sizes mostly from 220 to 300 μm. The relationship between the process variables with the shape and size of the alginate drops before and after the gelation was established with aid of optical image analysis. The results showed that a critical Ohnesorge number (Oh) > 0.24 was required to form spherical microencapsulated beads. The biodiesel production via esterification/transesterification reaction was performed using the crude Jatropha curcas L. oil as feedstock in a batch reactor using lipase microcapsules as biocatalysts. Under the optimal reaction condition (ethanol-to-oil mass ratio: 10; water content 9.1 wt%, microencapsulated biocatalyst mass: 5.25 g, reaction temperature: 35 °C, pH of reaction mixture 7.5, stirring force 6 g), an approximately 95% fatty acid ethyl esters (FAEE) yield could be obtained. The biodiesel obtained from this work completely satisfied with the related ASTM D6751 and EN14214 standards. The microencapsulation technique reported herein allows the production of lipase microcapsules on a continuous large scale with the characteristics required for sustainable biofuel production and it can be also applied in other fields such as food processing and the pharmaceutical industry. [ABSTRACT FROM AUTHOR]

2,5-furanediformate Isooctyl is a potential new green biobased plasticizer. At present, most of the preparation methods are chemical methods, which not only have many by-products and are difficult to separate, but also cause environmental pollution. In this paper, the immobilized lipase Novozym435 was used as the catalyst to catalyze the transesterification of 2,5-furanediformate dimethyl ester and isooctyl alcohol to prepare 2,5-furanediformate isoocty in organic medium, and the reaction process was optimized. The optimal process conditions were determined by single factor experiment: in 10 mL toluene system, the additional amount of immobilized lipase Novozym435 was 0.02 g, the molar ratio of 2,5-furanediformate dimethyl ester (1 mmol) and isooctyl alcohol was 1:4, and 1 g 4Å molecular sieve was added to the reaction system, the reaction temperature was 50°C, the reaction time was 24 h, and the conversion rate of 2,5-furanediformate isoocty was 89.63%. [ABSTRACT FROM AUTHOR]

Summary: Biodiesel is an evolving energy substitute for petroleum‐based fuel products. In terms of antropogenic impacts, it is an environmentally friendly and sustainable energy source. Biodiesel is produced from a wide variety of biomass materials and its production costs are mainly related to the feedstock and production process. Transesterification is the most commonly used method for biodiesel production. Enzymatic transesterification using lipase‐enzyme has certain advantages over acid‐alkaline transesterification. The issues relating to enzyme stability, separation, and recyclability in enzymatic transesterification are further improved using immobilized enzymes. Here, we review the potential of immobilized‐enzyme technology in biodiesel production as a safer strategy to meet the needs of a sustainable future economy and will conduct future research studies. We critically analyze the state‐of‐the‐art and latest research on the production of biodiesel using immobilized lipase enzymes. Results indicate that liquid lipase's immobilization increases the stability, reactivity, and reusability and significantly decreases biodiesel production costs [ABSTRACT FROM AUTHOR]

Lipase-catalyzed transesterification is prevalent in industrial production and is an effective alternative to chemical catalysis. However, due to lipases' unique structure, the reaction requires a biphasic system, which suffers from a low reaction efficiency caused by a limited interfacial area. The use of emulsion particles was found to be an effective way to increase the surface area and activity. This research focuses on cellulose as a natural surfactant for oil-in-water emulsions and evaluates the ability of lipase, introduced into the emulsion's aqueous phase, to integrate with the emulsion microparticles and catalyze the transesterification reaction of high molecular weight esters dissolved in the particles' cores. Cellulose-coated emulsion particles' morphology was investigated by light, fluorescence and cryogenic scanning electron microscopy, which reveal the complex emulsion structure. Lipase activity was evaluated by measuring the hydrolysis of emulsified p-nitrophenyl dodecanoate and by the transesterification of emulsified methyl laurate and oleyl alcohol dissolved in decane. Both experiments demonstrated that lipase introduced in the aqueous medium can penetrate the emulsion particles, localize at the inner oil core interface and perform effective catalysis. Furthermore, in this system, lipase successfully catalyzed a transesterification reaction rather than hydrolysis, despite the dominant presence of water. [ABSTRACT FROM AUTHOR]

Recently, several scientific groups investigated the suitable enzymatic route for synthesis of structured phenolic lipids for cosmetic and nutritive purposes. The feruloylated palm stearin (FPS) was obtained from enzymatic transesterification reactions of palm stearin with ferulic acid in solvent-free media with 1 mmol of glycerol or without it, using non-specific lipases, NovoCor ADL (Candida antarctica lipase A); Novozyme435® (Candida antarctica lipase B), and 1,3-specific lipase Lipozyme TL 100L from Thermomyces lanuginosus. The individual lipases and their combinational systems were examined. ESI+-MS/MS confirmed the formation of 19 feruloylated compounds. FPSs were produced by all lipases and their combinations. The positive synergetic effect occurred for 1,3-specific lipase and unspecified lipases with mass ratio 8:2, respectively. The antioxidant activities of all FPSs were examined. FPS produced by NovoCor ADL lipase in presence of free glycerol showed an antioxidant activity 10.3-times higher. In conclusion, the two low-cost lipases NovoCor ADL and Lipozyme TL 100L and its combi-lipase system could be considered suitable low-cost alternative to the expensive wide use N435 lipase in the solvent free production process of FPS for food and cosmetic applications. [ABSTRACT FROM AUTHOR]

Lipase's thermostability and organic solvent tolerance are two crucial properties that enable it to function as a biocatalyst. The present study examined the characteristics of two recombinant thermostable lipases (Lk2, Lk3) based on transesterification activity. Conversion of C12-C18 methyl ester with paranitrophenol was investigated in various organic solvent. Both lipases exhibited activity on difference carbon chain length (C12 - C18, C18:1, C18:2) of substrates. The activity of Lk2 was higher in each of substrate compared with that of Lk3. Experimental findings showed that the best substrates for Lk2 and Lk3 are C18:1 and C18:2 respectively, in agreement with the computational analysis. The activity of both enzymes prefers on nonpolar solvent. On nonpolar solvent the enzymes are able to keep its native folding shown by the value of radius gyration, solvent--enzyme interaction and orientation of triad catalytic residues. Lk3 appeared to be more thermostable, with maximum activity at 55°C. The presence of Fe3+ increased the activity of Lk2 and Lk3. However, the activity of both enzymes were dramatically decreased by the present of Ca2+ despite of the enzymes belong to family I.1 lipase known as calcium dependent enzyme. Molecular analysis on His loop of Lk2 and Lk3 on the present of Ca2+ showed that there were shifting on the orientation of catalytic triad residues. All the data suggest that Lk2 and Lk3 are novel lipase on the family I.1 and both lipase available as a biocatalyst candidate. [ABSTRACT FROM AUTHOR]

To develop potent and safer analgesics, we designed and synthesized a novel enantiomerically enriched ethereal analog of (R)-iso-moramide, namely 2-[(2R)-2-(morpholin-4-yl)propoxy]-2,2-diphenyl-1-(pyrrolidin-1-yl)ethan-1-one. The titled active agent can potentially serve as a powerful synthetic opiate with an improved affinity and selectivity toward opioid receptors (ORs). This hypothesis was postulated based on docking studies regarding the respective complexes between the designed ligand and µ-OR, δ-OR, and κ-OR. The key step of the elaborated asymmetric synthesis of novel analog involves lipase-catalyzed kinetic resolution of racemic 1-(morpholin-4-yl)propan-2-ol, which was accomplished on a 10 g scale via an enantioselective transesterification employing vinyl acetate as an irreversible acyl donor in tert-butyl methyl ether (MTBE) as the co-solvent. Next, the obtained homochiral (S)-(+)-morpholino-alcohol (>99% ee) was functionalized into corresponding chloro-derivative using thionyl chloride (SOCl2) or the Appel reaction conditions. Further transformation with N-diphenylacetyl-1-pyrrolidine under phase-transfer catalysis (PTC) conditions using O2-saturated DMSO/NaOH mixture as an oxidant furnished the desired levorotatory isomer of the title product isolated in 26% total yield after three steps, and with 89% ee. The absolute configuration of the key-intermediate of (R)-(–)-iso-moramide was determined using a modified form of Mosher's methodology. The preparation of the optically active dextrorotatory isomer of the titled product (87% ee) was carried out essentially by the same route, utilizing (R)-(–)-1-(morpholin-4-yl)propan-2-ol (98% ee) as a key intermediate. The spectroscopic characterization of the ethereal analog of iso-moramide and the enantioselective retention relationship of its enantiomers using HPLC on the cellulose-based chiral stationary phase were performed. Moreover, as a proof-of-principle, single-crystal X-ray diffraction (XRD) analysis of the synthesized 2-[(2R)-2-(morpholin-4-yl)propoxy]-2,2-diphenyl-1-(pyrrolidin-1-yl)ethan-1-one is reported. [ABSTRACT FROM AUTHOR]

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 ration 5.50:1, enzyme concentration 19 % v/ w, Tween 80 concentration 19 mg L–1, temperature 40 °C and reaction time 46 h). [ABSTRACT FROM AUTHOR]

Undeveloped Periplaneta americana oil (acid value 38.32 mg KOH/g) was directly used for one-step production of biodiesel with lipase without acid-pretreatment step for the commercial alkaline process. Biodiesel was produced via simultaneous esterification and transesterification of Periplaneta americana oil in the presence of lipase Eversa® Transform 2.0 (ET2) (12 US$/kg) in solvent-free system. The maximum biodiesel yield of 98.63 % was obtained under the optimized conditions of 32 °C, 8.5 wt.% lipase dosage, 8 h, 6.5/1 methanol/oil molar ratio, and 4 wt.% water. Lipase ET2 was recycled 6 times at > 89.52 % biodiesel yield. Biodiesel yield of 93.94 % was further achieved in a 1 L reactor with 15.08 g/kg lipase/biodiesel. Biodiesel cost was estimated as 589.3 US$/ton. Kinetics study gave activation energy of 24.50 kJ/mol with kinetic Michaelis constant of 1.19 mol/L. The physicochemical properties of biodiesel met both Chinese national and US ASTM standards that could be blended with petro-diesel to be applied in both countries. This study suggests that lipase could directly catalyze waste oils for the production of biodiesel at low temperature. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Enzymatic transesterification with natural oils allows for the preparation of PEs. • One-step transesterification yields an oil rich in two functional substances. • AYS "Amano" exhibits the highest catalytic activity in the transesterification. • Over 70% phytosterol is converted to PEs in the reaction catalyzed by AYS "Amano". • Manipulation of oil species enables regulation of the fatty acid composition of PEs. Phytosterol esters (PEs) and diacylglycerols (DAGs) have various health benefits in humans. In this study, PEs and DAGs were synthesized by lipase-catalyzed transesterification between a natural oil and phytosterols. First, commercial lipases were screened for transesterification and were further verified using multiple-ligand molecular docking. AYS "Amano" (a lipase from Candida rugosa) was found to be the optimum lipase. Subsequently, the enzymatic transesterification conditions were optimized. The optimized conditions were determined to be a 1:2 M ratio of phytosterols to oil, 100 mmol/L phytosterols, and 9 % AYS "Amano", and 50 °C for 24 h in 20 mL n -hexane. Under these conditions, over 70 % of phytosterols were converted to PEs. In this study, an efficient enzymatic process was developed to produce value-added functional oils rich in PEs and DAGs, with PEs content ≥ 31.6 %, DAGs content ≥ 11.2 %, acid value ≤ 0.91 mg KOH/g, and peroxide value ≤ 2.38 mmol/kg. [ABSTRACT FROM AUTHOR]

The β-blocker (S)-esmolol, has been synthesized in 97% enantiomeric excess and 26% total yield in a four-step synthesis, with a transesterification step of the racemic chlorohydrin methyl 3-(4-(3-chloro-2-hydroxypropoxy)phenyl)propanoate, catalysed by lipase B from Candida antarctica from Syncozymes, Shanghai, China. The β-blocker (S)-penbutolol, has been synthesized in 99% enantiomeric excess and in 22% total yield. The transesterification step of the racemic chlorohydrin 1-chloro-3-(2-cyclopentylphenoxy)propan-2-ol was catalyzed by the same lipase as used for the esmolol building block. We have used different bases for the deprotonation step of the starting phenols, and vinyl butanoate as the acyl donor in the transesterification reactions. The reaction times for the kinetic resolution steps catalysed by the lipase varied from 23 to 48 h, and were run at 30–38 °C. Specific rotation values confirmed the absolute configuration of the enantiopure drugs, however, an earlier report of the specific rotation value of (S)-esmolol is not consistent with our measured specific rotation values, and we here claim that our data are correct. Compared to the previously reported syntheses of these two enantiopure drugs, we have replaced toluene or dichloromethane with acetonitrile, and replaced the flammable acetyl chloride with lithium chloride. We have also reduced the amount of epichlorohydrin and bases, and identified dimeric byproducts in order to obtain higher yields. [ABSTRACT FROM AUTHOR]

BACKGROUND: There is an urgent need for renewable energy sources as alternatives for fossil fuels. A promising alternative is biodiesel. This study is part of an overall objective to convert cellulose from pretreated biomass directly to biodiesel, using cellulose‐coated emulsion particles as micro‐reactors for a cascade of biochemical reactions in a 'one‐pot' consolidated process. RESULTS: This study presents a 'proof‐of‐concept' for the crucial step in this process: the ability of lipase integrated within oil‐in‐water emulsion particles encapsulated by natural cellulose to catalyze transesterification of encapsulated oil with ethanol dissolved in an aqueous medium. We develop and examine such integrated microparticles for generation of fatty acid ethanol ester (FAEE) by lipase‐catalyzed transesterification of castor oil at the particle core–shell interface with aqueous ethanol. The activity of lipase‐catalyzed transesterification was studied using NMR quantification of FAEE while various conditions such as oil‐to‐ethanol molar ratio, lipase concentration and temperature were examined. The highest conversion was obtained for an oil‐to‐ethanol molar ratio of 1:30 with lipase concentration of 6.42 × 10−3 wt% at 40 °C. CONCLUSIONS: It is expected that the results of this study, together with ongoing experiments of ethanol production by integration of cellulose‐coated emulsion particles with yeasts and cellulolytic enzymes, as well as further optimization, will provide the complete transformation of cellulose to biodiesel by enzymatic hydrolysis, yeast fermentation and lipase‐catalyzed transesterification, in a single emulsion‐based consolidated bioprocess. © 2022 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

This study aimed to optimize the green synthesis of glucose palm oleate catalyzed by Carica papaya Lipase (CPL) through transesterification in a solvent-free system. Palm olein was used as a fatty acid donor for transesterification reactant and was also employed as a reaction medium. Reaction optimization was performed by using response surface methodology (RSM). Seventeen synthesis conditions were generated by a Box–Behnken design and the products were further determined by ultra-performance liquid chromatography (UPLC). Fatty acid compositions of palm olein identified by gas chromatography-mass spectrometry (GC-MS) found that oleic acid (51.77 ± 0.67%) and palmitic acid (37.22 ± 0.48%) were major components. The synthesis variable factors of 50 °C, 45 h reaction time, and 1400 U of CPL were predicted by the RSM to be optimum conditions and thus provided the highest glucose palm oleate of 0.3542 mmol/g. Conjugation between palm olein fatty acids and glucose via transesterification resulted in glucose palm oleate being obviously verified by UPLC, Fourier-transform infrared spectroscopy (FTIR), and thin-layer chromatography (TLC) analyses. The synthesized sugar fatty acid ester revealed an HLB value of 6.20 represented by the lowest % creaming index (%CI) of 35.40 ± 3.21%. It also exhibited a critical micelle concentration (CMC) of 3.16 × 10−5 M. This study is the first report to reveal the transesterification of glucose and palm olein catalyzed by CPL in a system without using any solvent. Glucose palm oleate has been shown to be derived from an environmentally friendly synthesis process and would be promising as a potential alternative natural surfactant for cosmetic application. [ABSTRACT FROM AUTHOR]

One of the indispensable applications of lipases in modification of oils and fats is the possibility to tailor the fatty acid content of triacylglycerols (TAGs), to meet specific requirements from various applications in food, nutrition, and cosmetic industries. Oleic acid (C18:1) and stearic acid (C18:0) are two common long fatty acids in the side chain of triglycerides in plant fats and oils that have similar chemical composition and structures, except for an unsaturated bond between C9 and C10 in oleic acid. Two lipases from Rhizomucor miehei (RML) and Rhizopus oryzae (ROL), show activity in reactions involving oleate and stearate, and share high sequence and structural identity. In this research, the preference for one of these two similar fatty acid side chains was investigated for the two lipases and was related to the respective enzyme structure. From transesterification reactions with 1:1 (molar ratio) mixed ethyl stearate (ES) and ethyl oleate (EO), both RML and ROL showed a higher activity towards EO than ES, but RML showed around 10% higher preference for ES compared with ROL. In silico results showed that stearate has a less stable interaction with the substrate binding crevice in both RML and ROL and higher tendency to freely move out of the substrate binding region, compared with oleate whose structure is more rigid due to the existence of the double bond. However, Trp88 from RML which is an Ala at the identical position in ROL shows a significant stabilization effect in the substrate interaction in RML, especially with stearate as a ligand. [ABSTRACT FROM AUTHOR]

The excessive utilization of petroleum resources leads to global warming, crude oil price fluctuations, and the fast depletion of petroleum reserves. Biodiesel has gained importance over the last few years as a clean, sustainable, and renewable energy source. This review provides knowledge of biodiesel production via transesterification/esterification using different catalysts, their prospects, and their challenges. The intensive research on homogeneous chemical catalysts points to the challenges in using high free fatty acids containing oils, such as waste cooking oils and animal fats. The problems faced are soap formation and the difficulty in product separation. On the other hand, heterogeneous catalysts are more preferable in biodiesel synthesis due to their ease of separation and reusability. However, in-depth studies show the limited activity and selectivity issues. Using biomass waste-based catalysts can reduce the biodiesel production cost as the materials are readily available and cheap. The use of an enzymatic approach has gained precedence in recent times. Additionally, immobilization of these enzymes has also improved the statistics because of their excellent functional properties like easy separation and reusability. However, free/liquid lipases are also growing faster due to better mass transfer with reactants. Biocatalysts are exceptional in good selectivity and mild operational conditions, but attractive features are veiled with the operational costs. Nanocatalysts play a vital role in heterogeneous catalysis and lipase immobilization due to their excellent selectivity, reactivity, faster reaction rates owing to their higher surface area, and easy recovery from the products and reuse for several cycles. [ABSTRACT FROM AUTHOR]

Lipase-catalyzed transesterification between refined bleached deodorized palm olein (RBDO) and palm kernel oil (RBDPKO) has been investigated to produce medium-long-medium structured lipid (MLM-SL). The synthesis was catalyzed by a specific sn-1,3 commercial lipase (Lipozyme TL IM) in batch and continuous systems. Progress of the transesterification of this study was monitored as triacylglycerol (TAG) with equivalent carbon number (ECN) 40, presumably that of 1,3-dilauryl-2-oleoyl-sn-glycerol (LaOLa). The results showed that lipase-catalyzed transesterification using RBDO and RBDPKO could potentially be used as the main substrate for MLM-SL synthesis, both for batch and continuous systems. In batch system, transesterification of RBDO and RBDPKO at the ratio of 1:2 at 50°C yielded in the highest concentration of ECN 40 (LaLaO/LaOLa, 7.34%) but also a higher total concentration of partial acylglycerol fractions (Di- and Monoacylglycerols; DAGs and MAGs). Thus, this condition also obtained transesterified lipid rich in EC N40 with a lower slip melting point as compared to other substrate ratios. In a continuous system, transesterification at RDBO:RBDPKO of 1:1 at 50°C and 15 min of residence time were selected as the optimum conditions, resulting in 5.39% EC N40 with a minimum concentration of DAGs and MAGs. [ABSTRACT FROM AUTHOR]

Distillers corn oil (DCO), a by‐product from the corn ethanol production, is an alternative source of glycerides to produce biodiesel. In the present work, this feedstock was enzymatically converted into fatty acid ethyl esters (FAEE). DCO presented relative density of 0.912 g/cm3, peroxide index of 3.05 ± 0.3 (meq/1000 g of sample) and acidity of 13.1 ± 1.96 (wt.%), with prevalence of the oleic (18:1) and linoleic (18:2) acids (sum equal to 76.9%). Three strategies were evaluated to improve the FAEE content: ethanol stepwise addition (ethanol:oil molar ratio of 4:1 (1/2 of ethanol at 0 and 1.5 h) and 3:1 (1/3 of ethanol at 0 h and 2/3 at 1.5 h or 1/3 of ethanol at 0, 1 and 2 h)); consecutive reactions (with Novozym 40086 [Rhizomucor miehei lipase] as biocatalyst); and mixture of enzymes (Novozym 40086 (6 wt.%) + Novozym 435 (Candida antarctica B lipase) (2 wt.%). The concept of combi‐lipases was evaluated for the first time using this raw material, resulting in a high ester content (>96%). The higher ester yields attained with DCO, compared to refined corn oil (33%) can be related to the better solubilization of ethanol and/or glycerol by‐product in the medium with DCO. The combi‐lipase system kept high than 80% of this initial activity after three repeated batches of reaction. The use of DCO enables the integration of corn ethanol and biodiesel production within the same general facility, which has logistic, environmental and, economic relevance. [ABSTRACT FROM AUTHOR]

Biodiesel is currently regarded as a sustainable and renewable alternative to depleting fossil fuels such as petro-diesel. Biodiesel production on a large scale could have a positive impact on the energy sector and the environment by lowering greenhouse gas emissions. Disadvantages of biodiesel include utilization of high-cost edible oils for production of biofuels, generation of wastewater and inability to recycle catalysts after alkaline-catalyzed methanolysis. The objectives of the current study were to utilize low-cost, inedible tallow to produce biodiesel from Lewatit-immobilized lipase produced from Bacillus pumilus and to measure the fuel properties and exhaust emissions of the resulting fatty acid methyl esters. Response surface methodology was used to optimize reaction conditions and alkaline (potassium hydroxide; KOH) catalysis was performed for comparison. A conversion of 96% was achieved by two step chemical-mediated transesterification, whereas conversion was 67% for the single step lipase-mediated method. Acid pre-treatment was needed in the case of KOH-catalyzed transesterification to reduce the acid value of tallow from 17.6 to 1.3 mg KOH/g, whereas the Lewatit-immobilized lipase was able to efficiently catalyse both transesterification of glycerides and esterification of free fatty acids. To the best of our knowledge, the lipase from B. pumilus has not yet been studied for biodiesel production from tallow. Fuel properties of the resulting optimized biodiesel were within the limits prescribed in ASTM D6751 and EN 14214. In addition, exhaust emissions studies revealed reduced CO and PM relative to petro-diesel. In both cases, reductions were greater as the percentage of biodiesel increased in blends with petro-diesel. However, NO. emissions were elevated versus petrodiesel in blends that contained 50% or more of biodiesel. This research reveals new ways for utilization of waste animal fats for biodiesel production as well as a new efficient lipase source that yields more products and provides environmental and economic security. [ABSTRACT FROM AUTHOR]

Lipase production was achieved using a thermo-alkalophilic-halophilic-ionic liquid-tolerant strain of Klebsiella aerogenes IBGE-ASQ-AA-BC-004, with mustard oilcake serving as the substrate. This production holds significance for various biotechnological applications, particularly in biodiesel and detergent manufacturing. Notably, the bacterium demonstrated lipase production containing 15 % w w−1 of various ionic liquids, showcasing its resilience and adaptability to adverse chemical conditions—crucial attributes for industrial utilization. Several experiments were designed to optimize the lipase production conditions, revealing rice bran as the most effective carbon source among the tested untreated agricultural residues. Ionic liquid pretreatment not only facilitated bacterial growth but also enhanced lipase production, indicating a synergistic effect. Supplementing mineral medium with oilcakes from various oils, notably mustard oilcake, significantly promoted bacterial growth and increased lipase production. Addition of Tween 20 and polyethylene glycol surfactants substantially boosted lipase production, potentially enhancing enzyme stability and substrate accessibility. The stability of the purified lipase was assessed under various conditions to determine its thermostability, alkalophilic nature, and tolerance to ionic liquids. These properties were evaluated by incubating the enzyme under different temperatures ranging from 25 to 80 °C for 24 h to assess thermostability, varying pH values from 4 to 12 for 24 h to determine alkalophilic behavior, and exposure to 20 % (w v−1) ionic liquids for 24 h to establish tolerance. The produced lipase was subjected to the transesterification of waste cooking oil, yielding 83.21 % fatty acid methyl ester after 24 h. This high yield demonstrates the effectiveness of the optimized lipase in biodiesel production, contributing to sustainable energy production by utilizing waste and renewable resources. [Display omitted] • An ionic liquid tolerant strain was isolated from saltern soil. • Bacterial strain tolerated 15 % w w−1 of different ILs. • Lipase was produced from mustard oilcake. • Klebsiella aerogenes produced lipase at 8 pH and 45 °C. • The FAME yield of 83.21 % was achieved. [ABSTRACT FROM AUTHOR]

Lipases are increasingly attracting attention in green and sustainable biodiesel production. Currently, the research emphasis lies in immobilizing unstable lipase onto carriers to enhance its performance. Polyacrylonitrile fiber (PANF) is considered to be a promising material for lipase immobilization due to its excellent properties. In this study, functional carriers with regulated surface hydrophobicity were obtained by loading functional groups on PANF via reversible addition-fragmentation chain transfer (RAFT) polymerized modification, and Candida rugosa lipase (CRL) was covalently immobilized on the carrier with glutaraldehyde as a linker. By employing this optimized biocatalyst PANF@BMA&2VImBr-NH 2 -CRL in the transesterification process, the yield of biodiesel derived from soybean oil reached an impressive 92.7 %. The outstanding performance can be attributed to the activation of lipase interface induced by hydrophobic microenvironment derived from alkyl ester on the carrier skeleton. Moreover, the stability and storage performance of immobilized lipase were significantly improved. The immobilized lipase exhibited facile recovery and maintained a consistent biodiesel yield of 80.9 % even after undergoing 5 cycles of reuse, thereby highlighting its potential for sustainable production. To sum up, our research demonstrates that the designed and prepared process of PANF-supported lipase offers a promising approach for enzyme immobilization, thereby presenting extensive potential applications in the field of biotechnology. [Display omitted] • RAFT polymerization improved the loading of lipase on polyacrylonitrile fiber. • The hydrophobic microenvironment activated lipase. • Fiber supported lipase catalyst could be reused for many times. [ABSTRACT FROM AUTHOR]

[Display omitted] • The mechanism of CRL transesterification was studied by experiments and simulations. • AuNPs can improve the performance of CRL by regulating the structure. • Mb can replace CRL in the reduction of HAuCl 4 during hybridization. • CRL-AuNPs showed higher catalytic performance in the transesterification reaction. This study established a Candida rugosa lipase (CRL) system to catalyze triolein and ethyl ferulate interesterification. The products were identified, and the binding mode between the substrates and CRL was predicted through molecular docking. Three methods for preparing CRL-AuNPs were proposed and characterized. It was found that the addition of 40 mL of 15 nm gold nanoparticles increased the CRL activity from 3.05 U/mg to 4.75 U/mg, but the hybridization efficiency was only 32.7 %. By using 4 mL of 0.1 mg/mL chloroauric acid, the hybridization efficiency was improved to 50.7 %, but the enzyme activity was sharply decreased. However, when the molar ratio of Mb to HAuCl 4 was 0.2, the hybridization efficiency increased to 71.8 %, and the CRL activity was also enhanced to 5.98 U/mg. Under optimal conditions, the enzyme activity of CRL-AuNPs③ was maintained at 95 % after 6 repetitions and 85.6 % after 30 days at room temperature. [ABSTRACT FROM AUTHOR]

An efficient lipase‐catalyzed stereoselective transesterification reaction system was established for resolution of 1‐(4‐methoxyphenyl)ethanol (MOPE) enantiomers. A series of lipases were tested and compared. The immobilized lipase Novozym 40086 is selected as the best choice. The effects of organic solvent, acyl donor, time and temperature on substrate conversion (c), and optical purity of the remaining substrate (eeS) were investigated. Response surface methodology and central composite design were employed to evaluate the effect of some important factors and to optimize the process. Under the optimized conditions including solvent of n‐hexane, acyl donor of vinyl acetate, temperature of 35°C, substrate molar ratio of 1:6, enzyme dosage of 20 mg, and reaction time of 2.5 h, eeS of 99.87% with c of 56.71% is achieved. The use of alkane solvent and immobilized enzyme, the mild reaction conditions, and the reduced reaction time make the system promising in industrial application. [ABSTRACT FROM AUTHOR]

The present work aims to evaluate the synergistic effect of imidazolium-based ionic liquids (IL) in the preparation and immobilization of Burkholderia cepacia lipase in a new hybrid support of poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) and silica. In addition, these biocatalysts were applied in transesterification reactions of crude coconut oil for the production of ethyl esters. Lipase immobilized on hybrid support with [C4min][NTf2] or [C6min][NTf2] ionic liquid exhibited nearly ≈ 1.6-fold immobilization yield greater than IB-Control. The use of IL during the preparation of the hybrid support promoted changes in its morphological structure as presented by B.E.T. and FTIR. Thermogravimetric analyzes were used to characterize the prepared derivatives and support the results of immobilization yields and the synergic effect of IL used. Transesterification reactions applying biocatalysts showed that the conversion maximum in esters (59%) was found under conditions of molar ratio 1:7 (oil:ethanol) in 72 h of reaction. These results were obtained using [C4min][NTf2] during the preparation of the hybrid support for the immobilization of Burkholderia cepacia lipase, thus showing the potential of these new biocatalysts. [ABSTRACT FROM AUTHOR]

[Display omitted] • Purification and characterisation of methanol tolerant lipase from Bacillus mycoides. • Algal lipid transesterification employing cross-linked lipase enzyme aggregate. • Analysis of algal biodiesel (FAME) by TLC and FTIR. • Comparative FTIR analysis of algal biodiesel, algal lipid, and petroleum. Methanol induced lipase inactivation is the major hindrance in commercialization of enzyme catalyzed biodiesel production. Thus, methanol tolerance is highly needed for the lipase to be used in transesterification reaction. Hence, by virtue of such desirability, a methanol tolerant, extracellular lipase FDS8(L) was extracted from Bacillus mycoides strain CV18 and purified to homogeneity with 22.3 % yield. It was a non-position specific, alkaline lipase with 44 kDa of relative molecular mass and had no isoforms (confirmed by zymography). It showed optimal activity at pH 9.0 and 30 °C temperature, while stability in the pH range 7.0–10.0 and temperature upto 50 °C. Organic solvents (hexane, acetone and methanol) as well as metal ions (Mg2+, Mn2+ and Na+) had stimulatory effects on lipase activity. Lipase immobilization was done using glutaraldehyde to form cross linked lipase enzyme aggregate (CLEA) which further enhanced its stability in the presence of methanol. Owing to its methanol tolerance property, it was employed heterogeneously for catalyzing transesterification of algal lipids in methanol. The qualitative efficacy of the FDS8 lipase in converting algal lipids into biodiesel was confirmed after analyzing the hexane extracted transesterification products by TLC and FTIR spectroscopy. [ABSTRACT FROM AUTHOR]

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Herein we report on the development and application of chemoenzymatic Dynamic Kinetic Asymmetric Transformation (DYKAT) of α‐substituted β‐hydroxyketones (β‐HKs), using Candida antartica lipase B (CALB) as transesterification catalyst and a ruthenium complex as epimerization catalyst. An operationally simple protocol allows for an efficient preparation of highly enantiomerically enriched α‐substituted β‐oxoacetates. The products were obtained in yields up to 95 % with good diastereomeric ratios. [ABSTRACT FROM AUTHOR]

Biodiesel is a renewable, sulfur-free, toxic-free, and low carbon fuel which possesses enhanced lubricity. Transesterification is the easiest method employed for the production of biodiesel, in which the oil is transformed into biodiesel. Biocatalyst-mediated transesterification is more advantageous than chemical process because of its non-toxic nature, the requirement of mild reaction conditions, absence of saponification, easy product recovery, and production of high-quality biodiesel. Lipases are found to be the primary enzymes in enzyme-mediated transesterification process. Currently, researchers are using lipases as biocatalyst for transesterification. Lipases are extracted from various sources such as plants, microbes, and animals. Biocatalyst-based biodiesel production is not yet commercialized due to high-cost of purified enzymes and higher reaction time for the production process. However, research works are growing in the area of various cost-effective techniques for immobilizing lipase to improve its reusability. And further reduction in the production cost of lipases can be achieved by genetic engineering techniques. The reduction in reaction time can be achieved through ultrasonic-assisted biocatalytic transesterification. Biodiesel production by enzymatic transesterification is affected by many factors. Various methods have been developed to control these factors and improve biodiesel production. This report summarizes the various sources of lipase, various production strategies for lipase and the lipase-mediated transesterification. It is fully focused on the lipase enzyme and its role in biodiesel production. It also covers the detailed explanation of various influencing factors, which affect the lipase-mediated transesterification along with the limitations and scope of lipase in biodiesel production. [ABSTRACT FROM AUTHOR]

Lipase from Thermomyces lanuginosus is one of the most explored enzymes for the esterification of several added‐value industrial compounds, such as biodiesel, fragrances, and flavors. Its selectivity in these reactions is mostly related with its activity towards small alcohols. In this work, the impact of the chemical modification, with 4 dodecyl chains at its surface, was evaluated regarding its transesterification and esterification activities, comparing with the native form. Linear size‐differentiated alcohols (from 1 to 20 carbons in the aliphatic chain) were used to explore for the first time the effect of the chain length in both transesterification and esterification reactions, using p‐nitrophenyl palmitate and oleic acid as model compounds, respectively. The chemically modified lipase showed an outstanding improvement of its catalytic performance than the native enzyme, being this increase directly proportional to the size of the alcohols chain used as substrates. The enormous potential and remarkable versatility of this novel super catalyst was here demonstrated, where diverse types of esters, differing in their potential applications (biodiesel, cosmetics, fine chemistry), were efficiently synthesized. The produced esters were fully characterized by 1H NMR, GC‐MS, and FTIR. [ABSTRACT FROM AUTHOR]

[Display omitted] A variety of enzymes immobilization methods are being developed to enhance biocatalyst performance, particularly lipases, which have attracted much attention for their extensive applications. This review provides a bibliometric and patent analysis of lipase immobilization techniques by scientific papers and patents in Web of Science and WIPO databases. Immobilized lipases are being extensively used in the research areas of Chemistry and Biotechnology & Applied Microbiology, mainly for the production of flavor esters and biodiesel. China, India, and Brazil, and institutions related to these countries, stand out as the most academically productive in terms of lipase immobilization research since 1976 and in the last five years. Researchers from these countries with studies in the fields of Chemistry, Biotechnology, and Energy Fuels are highlighted in this review. Trend analysis of the last 5 and 10 years revealed that lipase immobilization techniques and materials, such as sol–gel synthesis, magnetic nanoparticles, and crosslinked enzyme aggregates, remain important; other technologies, including ionic liquids and ultrasonication, have been increasingly applied to improve lipase immobilization. Patent analysis revealed a large number of filed patents, indicative of the industrial potential of immobilized lipases. These findings underscore the importance of research on lipase immobilization for various applications. [ABSTRACT FROM AUTHOR]