scholarly journals Enzymatic Synthesis of Isopropyl Acetate by Immobilized   Bacillus cereus Lipase in Organic Medium

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Madan Lal Verma ◽  
Wamik Azmi ◽  
Shamsher Singh Kanwar
Keyword(s):  
Acetic Acid ◽  
Bacillus Cereus ◽  
Water Activity ◽  
Molecular Sieves ◽  
Immobilized Lipase ◽  
Molar Ratio ◽  
Ester Synthesis ◽  
Initial Water ◽  
Isopropyl Acetate ◽  
Mg Addition

Selective production of fragrance fatty acid ester from isopropanol and acetic acid has been achieved using silica-immobilized lipase of Bacillus cereus MTCC 8372. A purified thermoalkalophilic extracellular lipase was immobilized by adsorption onto the silica. The effects of various parameters like molar ratio of substrates (isopropanol and acetic acid; 25 to 100 mM), concentration of biocatalyst (25–125 mg/mL), reaction time, reaction temperature, organic solvents, molecular sieves, and initial water activity were studied for optimal ester synthesis. Under optimized conditions, 66.0 mM of isopropyl acetate was produced when isopropanol and acetic acid were used at 100 mM: 75 mM in 9 h at 55°C in n-heptane under continuous shaking (160 rpm) using bound lipase (25 mg). Addition of molecular sieves (3 Å  × 1.5 mm) resulted in a marked increase in ester synthesis (73.0 mM). Ester synthesis was enhanced by water activity associated with pre-equilibrated saturated salt solution of LiCl. The immobilized lipase retained more than 50% of its activity after the 6th cycle of reuse.

scholarly journals Immobilization of lipase on sepabeads and its application in pentyl octanoate synthesis in a low aqueous system

2008 ◽  
pp. 139-152 ◽  
Author(s):  
Zorica Knezevic-Jugovic ◽  
SvetlanaV. Saponjic ◽  
Dejan Bezbradica ◽  
Dusan Mijin
Keyword(s):  
Molecular Sieves ◽  
Immobilized Lipase ◽  
Candida Rugosa ◽  
Aqueous System ◽  
Molar Ratio ◽  
Process Conditions ◽  
Initial Water Content ◽  
Initial Water ◽  
Initial Substrate ◽  
Substrate Molar Ratio

The object of the study was to investigate the process conditions relevant for the pentyl octanoate production with the lipase from Candida rugosa immobilized on Sepabeads EC-EP carrier. This is an epoxide-containing commercial polymethacrylic carrier with suitable characteristics for enzyme immobilization. The immobilized lipase suitable for pentyl octanoate synthesis has been prepared by a direct lipase binding to polymers via their epoxide groups. The enzymatic activity was determined by both hydrolysis of olive oil in an aqueous system and esterification of n-pentanol with octanoic acid in a low aqueous system. The influence of several important reaction parameters such as temperature, initial water content, initial substrate molar ratio, enzyme loading and time of adding of molecular sieves in the system is carefully analyzed by means of an experimental design. Production of the ester was optimized and an ester production response equation was obtained, making it possible to predict ester yields from known values of the five main factors. Almost complete conversion (>99%) of the substrate to ester could be realized, using lipase loading as low as 37 mg/g dry support and in a relatively short time (24 h) at 45?C, when high initial substrate molar ratio of 2.2 is used.

scholarly journals Synthesis of Isopropyl Ferulate Using Silica-Immobilized Lipase in an Organic Medium

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Ashok Kumar ◽  
Shamsher Singh Kanwar
Keyword(s):  
Ferulic Acid ◽  
Molecular Sieves ◽  
Isopropyl Alcohol ◽  
Immobilized Lipase ◽  
Inhibitory Effect ◽  
Organic Medium ◽  
Molar Ratio ◽  
Forward Reaction ◽  
Salt Ions ◽  
The Matrix

Immobilization of lipases has proved to be a useful technique for improving an enzyme's activity in organic solvents. In the present study, the performance of a silica-immobilized lipase was evaluated for the synthesis of isopropyl ferulate in DMSO. The biocatalyst was cross-linked onto the matrix with 1% glutaraldehyde. The effects of various parameters, molar ratio of ferulic acid to isopropyl alcohol (25 mM : 100 mM), concentration of biocatalyst (2.5–20 mg/mL), molecular sieves (25–250 mg/mL), and various salt ions, were studied consecutively as a function of percent esterification. Immobilized lipase at 25 mg/mL showed maximum esterification (~84%) of ferulic acid and isopropanol at a molar ratio of 25 mM : 100 mM, respectively, in DMSO at 45°C in 3 h under shaking (150 rpm). To overcome the inhibitory effect of water (a byproduct) if any, in the reaction mixture, molecular sieves (3 Å × 1.5 mm; 100 mg/mL) were added to the reaction mixture to promote the forward reaction. Salt ions like Ca2+, Cd2+, and Fe2+ enhanced the activity of immobilized biocatalyst while a few ions like Co2+, Zn2+, Mg2+, Mn2+, Al3+, and Na+ had mild inhibitory effect. Approximately, one third of total decrease in the esterification efficacy was observed after the 5th repetitive cycle of esterification.

scholarly journals Green Synthesis of Decaglycerol Laurates by Lipase-Catalyzed Transesterification of Methyl Laurate with Decaglycerol

2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Wenyue Wang ◽  
Changyao Liu ◽  
Guiju Zhang ◽  
Fan Yang ◽  
Xiaoyan Wang ◽  
...  
Keyword(s):  
Immobilized Lipase ◽  
Orthogonal Test ◽  
Methyl Laurate ◽  
Molar Ratio ◽  
Initial Water Content ◽  
Ionization Mass ◽  
Optimum Conditions ◽  
Initial Water ◽  
Reaction Optimization ◽  
Enzyme Dosage

Decaglycerol laurates have been widely used as emulsifiers in food, medicine, and cosmetic industries for many years. Currently, they are synthesized using alkaline catalysts under stringent conditions. Here, decaglycerol laurates were prepared through a green lipase-catalyzed process, employing the transesterification of methyl laurate with decaglycerol by the immobilized lipase (Novozym 435). Single-factor experiments and orthogonal test were used for reaction optimization. The optimum conditions were obtained as follows: reaction temperature of 65°C, a laurate/decaglycerol molar ratio of 2 : 1, an oscillating speed of 180 rpm, an enzyme dosage (based on amount of methyl laurate) of 8 wt.%, initial water content (based on the total substrate mass) of 5.0 wt.%, and reaction time of 4.5 h with 84.4% conversion of methyl laurate. The transesterification products were identified by electrospray ionization mass spectrometer. In addition, the surface activity of decaglycerol laurates was also characterized, and the surface tension of water was reduced to 33 mN·m−1 at a concentration magnitude of 10−5 g/mL.

scholarly journals The immobilization of lipase on Sepabeads: Coupling, characterization and application in geranyl butyrate synthesis in a low aqueous system

2008 ◽  
Vol 14 (4) ◽  
pp. 245-249 ◽  
Author(s):  
Zorica Knezevic-Jugovic ◽  
Jasmina Damnjanovic ◽  
Dejan Bezbradica ◽  
Dusan Mijin
Keyword(s):  
Molecular Sieves ◽  
Immobilized Enzyme ◽  
Candida Rugosa ◽  
Aqueous System ◽  
Molar Ratio ◽  
Esterification Reaction ◽  
Initial Water Content ◽  
Initial Water ◽  
Organic System ◽  
Geranyl Butyrate

Lipase from Candida rugosa immobilized on Sepabeads EC-EP was shown to catalyze the esterification of geraniol with butyric acid in a predominantly organic system. The immobilization procedure was adjusted to optimize the enzyme activity and the immobilized enzyme was then used for a geranyl butyrate synthesis as a study model. The immobilized enzyme showed favorable performances in an aqueous system and increased the stability in the presence of organic solvents. The response surface methodology and a 5-level-5-factor central composite rotatable design were performed to identify the factors that influence the ester production and to verify whether any changes should be made in their settings to improve this reaction. The initial water content, the reaction temperature, the enzyme concentration, acid/alcohol molar ratio and time of addition of molecular sieves were the variables investigated. The production of the ester was optimized and an ester production response equation was obtained, making it possible to predict ester yields from the known values of the five main factors. The temperature during the esterification reaction was identified as the factor having the greatest impact on the ester yield.

scholarly journals Esterification of acetic acid with alcohol isoamyl in the presence of enzymatic catalyst

2019 ◽  
Vol 19 (2) ◽  
pp. 225-242
Author(s):  
Nádia Ligianara Nyari ◽  
Alessandro Rogerio Paulazzi ◽  
Raquel Vera Zamadei ◽  
Jamile Zeni ◽  
Rogério Marcos Dallago
Keyword(s):  
Acetic Acid ◽  
Reaction Time ◽  
Food Industry ◽  
Immobilized Lipase ◽  
Isoamyl Alcohol ◽  
Isoamyl Acetate ◽  
Ester Synthesis ◽  
Immobilized Catalyst ◽  
Ultrasound System ◽  
Enzymatic Catalyst

The Candida antarctica Lipase B immobilized on polyurethane catalysed esterification of acetic acid with isoamyl alcohol in mechanical and ultrasonic system in a system solvent-free, was studied. The maximum esterification of isoamyl acetate used immobilized catalyst was the highest esterification, 666.05 U/g with 19 cycles of reuse after 360 minutes of reaction time in mechanical system and 1319.48 U/g was observed and 14 cycles de reuse after 60 minutes of reaction time in ultrasound system. Thus, the process was considered efficient with significant reduction of the reaction time, low instrumental requirements and improve the bioprocess performance. Until now, there were no studies available in the open literature in relation to the ester synthesis catalyzed by immobilized Lipase in polyurethane as support in the ultrasound system. In addition, considered an environmentally correct and economically viable technology, it can be used in cosmetics, pharmaceuticals and food industry.

scholarly journals Optimization of lipase-catalyzed synthesis of polyethylene glycol stearate in a solvent-free system

2019 ◽  
Vol 8 (1) ◽  
pp. 30-37 ◽  
Author(s):  
Girish S. Nhivekar ◽  
Virendra K. Rathod
Keyword(s):  
Polyethylene Glycol ◽  
Molecular Sieves ◽  
Immobilized Lipase ◽  
Solvent Free ◽  
Molar Ratio ◽  
Resonance Spectroscopy ◽  
Free System ◽  
Immobilized Catalyst ◽  
Solvent Free System ◽  
The Impact

Abstract Polyethylene glycol stearate is widely used in pharmaceuticals and cosmetic industries. The current work describes the synthesis and optimization of polyethylene glycol stearate by esterification of polyethylene glycol 600 and stearic acid using Fermase CALBex 10000, a commercial immobilized lipase B in a solvent-free system. The impact of various parameters that include temperature, reaction time, biocatalyst loading, agitation, acid to alcohol molar ratio, and amount of molecular sieves was optimized to achieve maximum conversion. The highest conversion of 86.98% was obtained in 6 h under the following optimized conditions: temperature 70°C, biocatalyst loading 0.5%, acid to alcohol molar ratio 1:4, speed of agitation 300 rpm, and molecular sieves 5% (w/w). The final condensate product was analyzed through Fourier transform infrared spectroscopy to confirm the functional group and also by 1H nuclear magnetic resonance spectroscopy. The immobilized catalyst can be reused up to four cycles, exhibiting more than 60% of its initial activity.

Kinetic studies on esterification of acetic acid with isopropyl alcohol in presence of novel solid catalyst

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Mallaiah Mekala
Keyword(s):  
Acetic Acid ◽  
Kinetic Model ◽  
Isopropyl Alcohol ◽  
Frequency Factor ◽  
Activation Energies ◽  
Catalyst Loading ◽  
Solid Catalyst ◽  
Heat Of Reaction ◽  
Resin Catalyst ◽  
Isopropyl Acetate

AbstractThe reaction of isopropyl alcohol with acetic acid was carried out in an isothermal batch reactor in presence of solid resin catalyst to produce isopropyl acetate and water. A novel solid resin catalyst Indion 140 was used in the present study. The temperature of reaction mixture was maintained in the range of 333.15 – 363.15 K. The effects of reaction temperature, catalyst loading, mole ratio, size of catalyst, agitation speed were investigated on acetic acid conversion. Further, pseudo-homogeneous kinetic model was developed for the catalyzed reaction. The forward reaction rate constants and activation energies were determined from the Arrhenius plot. The forward and backward activation energies are found to 53,459 J/mol and 54,748 J/mol, respectively. The heat of reaction is −1.289 kJ/mol with Indion 140 catalyst. The mathematical equation was developed for frequency factor as function of the catalyst loading and found that it follows a linear relationship between frequency factor and catalyst loading. The simulations were performed for pseudo homogeneous kinetic model and found that the model is able to predict the experimental data very well. The developed kinetic equation is useful for the simulation of a reactive distillation column for the synthesis of isopropyl acetate.

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