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 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 Biocatalytic Synthesis of Flavor Ester “Pentyl Valerate” UsingCandida rugosaLipase Immobilized in Microemulsion Based Organogels: Effect of Parameters and Reusability

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Tripti Raghavendra ◽  
Nilam Panchal ◽  
Jyoti Divecha ◽  
Amita Shah ◽  
Datta Madamwar
Keyword(s):  
Candida Rugosa ◽  
Kinetic Studies ◽  
Product Formation ◽  
Enzyme Concentration ◽  
Valeric Acid ◽  
Free Form ◽  
Esterification Reaction ◽  
Initial Water Content ◽  
Initial Water ◽  
Positive Effect

Pentyl valerate was synthesized biocatalytically usingCandida rugosalipase (CRL) immobilized in microemulsion based organogels (MBGs). The optimum conditions were found to be pH 7.0, temperature of 37°C, ratio of concentration of water to surfactant (Wo) of 60, and the surfactant sodium bis-2-(ethylhexyl)sulfosuccinate (AOT) for MBG preparation. Although kinetic studies revealed that the enzyme in free form had high affinity towards substrates (Km= 23.2 mM for pentanol and 76.92 mM for valeric acid) whereas, after immobilization, theKmvalues increased considerably (74.07 mM for pentanol and 83.3 mM for valeric acid) resulting in a slower reaction rate, the maximum conversion was much higher in case of immobilized enzyme (~99%) as compared to free enzyme (~19%). Simultaneous effects of important parameters were studied using response surface methodology (RSM) conjugated with Box-Behnken design (BBD) with five variables (process parameters), namely, enzyme concentration, initial water content (Wo), solvent used for MBG preparation, substrate ratio and time, and response as the final product formation, that is, pentyl valerate (%). The MBGs were reused for 10 consecutive cycles for ester synthesis. Efficacy of AOT/isooctane as dehydrating agent for extracting excess water from MBGs was found to exert a positive effect on the esterification reaction.

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 Lipase catalyzed synthesis of flavor esters in non-aqueous media: Optimization of the yield of pentyl 2-methylpropanoate by statistical analysis

2008 ◽  
Vol 73 (12) ◽  
pp. 1139-1151 ◽  
Author(s):  
Zorica Knezevic-Jugovic ◽  
Dejan Bezbradica ◽  
Zivana Jakovljevic ◽  
Suzana Brankovic-Dimitrijevic ◽  
Dusan Mijin
Keyword(s):  
Reaction Time ◽  
Aqueous Media ◽  
Candida Rugosa ◽  
Enzyme Concentration ◽  
Yield Response ◽  
Process Conditions ◽  
Initial Water Content ◽  
Initial Water ◽  
Ester Yield ◽  
Added Water

In this study, the synthesis of pentyl 2-methylpropanoate employing a commercial lipase from Candida rugosa was investigated, the emphasis being placed on analyzing the effects of various process conditions on the yield of ester. The response surface methodology (RSM) and five-level-five-factor central composite rotatable design (CCRD) were used to evaluate the effects of variables, namely the initial water content, 0.0-2.0% (w/v), the reaction temperature, 35-75?C, the enzyme concentration, 1.0-5.0 g dm-3, the acid/alcohol mole ratio, 1:2-5:2, and the reaction time, 4-48 h, on the yield (%) of ester. The production of pentyl 2-methylpropanoate was optimized and an ester yield response equation was obtained, enabling the prediction of ester yields from known values of the five main factors. It seems that the enzyme concentration, reaction time and acid/alcohol mole ratio predominantly determine the conversion process, while the amount of added water amount had no significant influence on the ester yield. Conversion of around 92 % of the substrate to ester could be realized using a concentration of lipase as low as 4.0 g dm-3 and in a relatively short time (26 h) at 35?C, when a high substrate mole ratio of 2.5 was used.

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 influence of the presence of gasses in mineral oil on the ability of molecular sieves for water sorption

2019 ◽  
Vol 28 ◽  
pp. 01030
Author(s):  
Mateusz Cybulski ◽  
Piotr Przybylek
Keyword(s):  
Relative Humidity ◽  
Water Content ◽  
Molecular Sieves ◽  
Water Sorption ◽  
Mineral Oil ◽  
Gas Content ◽  
Initial Water Content ◽  
Initial Water

Previous studies has shown, that for the same relative humidity, the ability of molecular sieves to adsorb water in the air is higher than in mineral oil. One of the reasons for this difference may be the presence of dissolved gasses in the mineral oil. The effect of the presence of gasses in mineral oil on the ability of molecular sieves to adsorb water was experimentally investigated. Samples of non-degassed and degassed mineral oil with a similar initial water content were dried by means of activated 3A and 13X molecular sieves. The obtained results allowed to show that in the studied range of gas content in oil they do not affect the ability of molecular sieves for water sorption.

Free Candida Rugosa Lipase–Catalyzed Synthesis Of Citronellyl Butyrate In n–Hexane By Direct Esterification: Effect Of Reaction Parameters

2012 ◽  
Author(s):  
Irvan Dahlan ◽  
Azlina Harun @ Kamaruddin ◽  
Ghasem D. Najafpour
Keyword(s):  
Butyric Acid ◽  
Active Sites ◽  
Immobilized Lipase ◽  
Candida Rugosa ◽  
Candida Rugosa Lipase ◽  
Molar Ratio ◽  
Esterification Reaction ◽  
Reaction Parameters ◽  
Direct Esterification ◽  
Competitive Nature

Sintesis sitronelil butirat melalui pengesteran langsung telah dikaji di dalam n–hexane sebagai pelarut organik yang dimangkinkan oleh lipase bebas dan lipase tersekatgerak daripada Candida rugosa. Kajian telah dijalankan untuk mengesahkan pengaruh pelbagai parameter pada pembentukan sitronelil butirat oleh lipase bebas daripada Candida rugosa, iaitu kesan kepekatan lipase, nisbah molar substrat, suhu, tiga jenis bahan sokongan untuk lipase tersekatgerak dan nisbah sekatgerak. Peningkatan kepekatan lipase bebas menyebabkan peningkatan kepada penukaran asid. Sifat peningkatan tidak berubah dari tindak balas pengesteran dapat diperhatikan pada kepekatan lipase tinggi yang memberikan kepekatan optimum lipase pada 3.33 g/l dengan penukaran asid sebanyak 92%. Kemungkinan ini disebabkan oleh tapak aktif lipase yang berlebihan yang berada di dalam zarah lipase pukal, yang tidak memberi sumbangan bererti kepada tindak balas. Aktiviti lipase didapati terencat dengan bertambahnya kepekatan asid butirik (pada kepekatan sitronelol tetap) dan sitronelol (pada kepekatan asid butirik tetap). Ini disebabkan adanya persaingan semulajadi pengikatan alkohol dan asid. Penukaran asid optimum diperolehi pada suhu 40°C selepas 24 jam pengeraman. Bagaimanapun, atas dari suhu ini, aktiviti pengesteran yang dimangkinkan oleh lipase mula menurun kerana penyahaslian protein. Daripada tiga jenis sokongan yang digunakan untuk lipase tersekatgerak, Amberlite MB–1 menunjukkan penukaran asid tertinggi berbanding dengan Amberlite XAD–1180 dan Celite 545. Penukaran asid optimum diperolehi pada nisbah sekatgerak 10 mg lipase/g penyokong. Pada nisbah sekatgerak ini, lipase mengoptimumkan sentuhan dengan permukaan penyokong dengan mengekalkan konformasi yang aktif pada tahap optimum. Kata kunci: Sitronelil butirat; lipase Candida rugosa; pengesteran langsung; lipase tersekatgerak; pelarut organik Free and immobilized Candida rugosa lipases were investigated for the synthesis of citronellyl butyrate by direct esterification reaction in n–hexane as organic solvent. A set of experiments was carried out to verify the influence of various parameters on the formation of citronellyl butyrate by free Candida rugosa lipase, such as lipase loading, substrate molar ratio, temperature, three kinds of support for immobilization, and ratio of immobilization. The conversion was increased with increasing lipase loading. The behavior of leveling–off in esterification was observed at higher lipase loading which gave the optimal amount of lipase loading at 3.33 g/l with 92% conversion. This might be due to the excess of lipase active sites, which remained inside the bulk of lipase particles, was not contributing significantly to the reaction. Increasing butyric acid and citronellol concentrations (at fixed citronellol and butyric acid concentrations, respectively) inhibited the lipase activity due to competitive nature of alcohol and acid binding. Optimal acid conversion was obtained at 40°C after 24–h incubation time. Above this temperature, however, the activity of lipase–catalyzed esterification begins to decrease due to denaturation of protein. From the three kinds of supports for immobilized lipase, Amberlite MB–1 showed the highest conversion compared to Amberlite XAD–1180 and Celite 545. The optimal acid conversion was obtained at lipase loading of 10 mg lipase/g support. At this loading, lipase attempts to optimize its contact with the surface of the support whereby optimum active conformation was retained. Key words: Citronellyl butyrate; Candida rugosa lipase; direct esterification; immobilized lipase; organic media

scholarly journals Preparation of Immobilized Lipase Based on Hollow Mesoporous Silica Spheres and Its Application in Ester Synthesis

Molecules ◽  
2019 ◽  
Vol 24 (3) ◽  
pp. 395 ◽  
Author(s):  
Zhe Dong ◽  
Meng-Ying Jiang ◽  
Jie Shi ◽  
Ming-Ming Zheng ◽  
Feng-Hong Huang
Keyword(s):  
Reaction Time ◽  
Mesoporous Silica ◽  
Immobilized Lipase ◽  
Lipid Production ◽  
Candida Rugosa ◽  
Molar Ratio ◽  
Esterification Reaction ◽  
Enzymatic Esterification ◽  
Free System ◽  
Hollow Mesoporous Silica

In this study, Candida rugosa lipase (CRL) was immobilized into modified hollow mesoporous silica (HMSS) materials with different hydrophobicity. Among propyl-(C3), phenyl-(C6), octyl-(C8), and octadecyl-(C18) modified HMSS as well as native HMSS, taking advantage of more hydrophobic microenvironment, the HMSS-C18-CRL showed exceptional performance in enzymatic esterification reaction. Using the novel HMSS-C18 with immobilized CRL (HMSS-C18-CRL), we investigated the esterification of phytosterols with polyunsaturated fat acid (PUFA) in a solvent-free system for the production of phytosterols esters. Response surface methodology (RSM) was applied to model and optimize the reaction conditions, namely, the enzyme load (5–25%), reaction time (10–110 min), molar ratio of α-linolenic acid (ALA)/phytosterols (1:1–7:1) and represented by the letters E, T, and M respectively. Best-fitting models were successfully established by multiple regressions with backward elimination. The optimum production was achieved at 70 min for reaction time, 20% based on the weight of substrate for enzyme loading, and 5.6:1 for ALA/phytosterols molar ratio. Under optimized conditions, a conversion of about 90 ± 2% was achieved. These results indicated that HMSS-C18-CRL demonstrates to be a promising catalyst and can be potentially applied in the functional lipid production.

Influence of initial water content and strain rate on remolded yield stress in marine clay

2021 ◽  
pp. 1-8
Author(s):  
Xiaobing Li ◽  
Jianpeng Chen ◽  
Xiuqing Hu ◽  
Hongtao Fu ◽  
Jun Wang ◽  
...  
Keyword(s):  
Strain Rate ◽  
Water Content ◽  
Yield Stress ◽  
Initial Water Content ◽  
Marine Clay ◽  
Initial Water

scholarly journals Application of the Calorimetric Methods to the Characteristics of Seeds from Olives

Proceedings ◽  
2020 ◽  
Vol 70 (1) ◽  
pp. 90
Author(s):  
Andrzej Bryś ◽  
Joanna Bryś ◽  
Marko Obranović ◽  
Dubravka Škevin ◽  
Szymon Głowacki ◽  
...  
Keyword(s):  
Olive Oil ◽  
Water Content ◽  
Cooling System ◽  
Waste Product ◽  
Normal Pressure ◽  
Ash Content ◽  
Initial Water Content ◽  
Scanning Calorimetry ◽  
Initial Water

The olive oil industry represents an important productive sector in the Mediterranean basin countries. Olive stone is an essential by-product generated in the olive oil extraction industries and it represents roughly 10% by weight of the olive fruit. The seeds of pickled olives are also a significant waste product. In the present study, we have investigated the possibility of the use of differential scanning calorimetry for the thermal characterization of seeds from green and black pickled olives from Croatia. The differential scanning calorimeter (DSC) with a normal pressure cell equipped with a cooling system was used to determine the thermal properties of seeds from olives. The following analyses were also performed: the determination of calorific values in a pressure bomb calorimeter, the determination of initial water content, the determination of changes of water content during drying at the temperatures of 30 °C, 50 °C and 80 °C, the determination of a percentage content of seeds mass to the mass of the whole olives, and the determination of ash content. Seeds from olives are characterized by very good parameters as a biomass. The analyzed olive seeds were characterized by low water content, low ash content, and a relatively high caloric value.

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