TY  - JOUR
AU  - Ćorović, Marija
AU  - Mihailović, Mladen
AU  - Banjanac, Katarina
AU  - Carević, Milica
AU  - Milivojević, Ana
AU  - Milosavić, Nenad
AU  - Bezbradica, Dejan
PY  - 2017
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/3655
AB  - The aim of this study was to develop simple and efficient method for immobilization of Candida antarctica lipase B onto hydrophobic anion exchange resin Purolite(A (R)) MN102 and to apply immobilized catalyst for the enzymatic synthesis of two valuable esters-isoamyl acetate and l-ascorbyl oleate. At optimized conditions (1 M phosphate buffer pH = 7, 7 h at 25 A degrees C, and 18.75 mg of offered proteins g(-1) of support), immobilized lipase with hydrolytic activity of 888.4 p-nitrophenyl butyrate units g(-1) was obtained. Afterwards, preparation was applied for the solvent-free synthesis of isoamyl acetate from triacetin and isoamyl alcohol. At 75 A degrees C, 1 M of isoamyl alcohol, and 6 mg ml(-1) of enzyme 100 % yield was achieved in 6 h, while at prolonged reaction times, complete conversion was enabled even at lower temperatures, lower lipase loadings, and higher substrate concentrations. After 15 consecutive reuses (60 h), activity of catalyst dropped to 50 % of its initial value and total amount of 1.31 mol (170.55 g) of ester with 1 g of biocatalyst was produced. Even higher operational stability of lipase (25 % loss of activity in 200 h) was observed in the synthesis of l-ascorbyl oleate performed in organic solvent (t-butanol). Multiple use of one batch of immobilized biocatalyst in both cases led to a significant process cost reduction and substantial increment of corresponding productivities.
PB  - Springer, New York
T2  - Bioprocess and Biosystems Engineering
T1  - Immobilization of Candida antarctica lipase B onto Purolite(A (R)) MN102 and its application in solvent-free and organic media esterification
EP  - 34
IS  - 1
SP  - 23
VL  - 40
DO  - 10.1007/s00449-016-1671-0
ER  - 

@article{
author = "Ćorović, Marija and Mihailović, Mladen and Banjanac, Katarina and Carević, Milica and Milivojević, Ana and Milosavić, Nenad and Bezbradica, Dejan",
year = "2017",
abstract = "The aim of this study was to develop simple and efficient method for immobilization of Candida antarctica lipase B onto hydrophobic anion exchange resin Purolite(A (R)) MN102 and to apply immobilized catalyst for the enzymatic synthesis of two valuable esters-isoamyl acetate and l-ascorbyl oleate. At optimized conditions (1 M phosphate buffer pH = 7, 7 h at 25 A degrees C, and 18.75 mg of offered proteins g(-1) of support), immobilized lipase with hydrolytic activity of 888.4 p-nitrophenyl butyrate units g(-1) was obtained. Afterwards, preparation was applied for the solvent-free synthesis of isoamyl acetate from triacetin and isoamyl alcohol. At 75 A degrees C, 1 M of isoamyl alcohol, and 6 mg ml(-1) of enzyme 100 % yield was achieved in 6 h, while at prolonged reaction times, complete conversion was enabled even at lower temperatures, lower lipase loadings, and higher substrate concentrations. After 15 consecutive reuses (60 h), activity of catalyst dropped to 50 % of its initial value and total amount of 1.31 mol (170.55 g) of ester with 1 g of biocatalyst was produced. Even higher operational stability of lipase (25 % loss of activity in 200 h) was observed in the synthesis of l-ascorbyl oleate performed in organic solvent (t-butanol). Multiple use of one batch of immobilized biocatalyst in both cases led to a significant process cost reduction and substantial increment of corresponding productivities.",
publisher = "Springer, New York",
journal = "Bioprocess and Biosystems Engineering",
title = "Immobilization of Candida antarctica lipase B onto Purolite(A (R)) MN102 and its application in solvent-free and organic media esterification",
pages = "34-23",
number = "1",
volume = "40",
doi = "10.1007/s00449-016-1671-0"
}

Ćorović, M., Mihailović, M., Banjanac, K., Carević, M., Milivojević, A., Milosavić, N.,& Bezbradica, D.. (2017). Immobilization of Candida antarctica lipase B onto Purolite(A (R)) MN102 and its application in solvent-free and organic media esterification. in Bioprocess and Biosystems Engineering
Springer, New York., 40(1), 23-34.
https://doi.org/10.1007/s00449-016-1671-0

Ćorović M, Mihailović M, Banjanac K, Carević M, Milivojević A, Milosavić N, Bezbradica D. Immobilization of Candida antarctica lipase B onto Purolite(A (R)) MN102 and its application in solvent-free and organic media esterification. in Bioprocess and Biosystems Engineering. 2017;40(1):23-34.
doi:10.1007/s00449-016-1671-0 .

Ćorović, Marija, Mihailović, Mladen, Banjanac, Katarina, Carević, Milica, Milivojević, Ana, Milosavić, Nenad, Bezbradica, Dejan, "Immobilization of Candida antarctica lipase B onto Purolite(A (R)) MN102 and its application in solvent-free and organic media esterification" in Bioprocess and Biosystems Engineering, 40, no. 1 (2017):23-34,
https://doi.org/10.1007/s00449-016-1671-0 . .

TY  - JOUR
AU  - Simović, Milica
AU  - Ćorović, Marija
AU  - Mihailović, Mladen
AU  - Banjanac, Katarina
AU  - Milivojević, Ana
AU  - Veličković, Dušan
AU  - Bezbradica, Dejan
PY  - 2016
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/3374
AB  - The goal of this study was to establish an efficient immobilisation protocol for beta-galactosidase from Aspergillus oryzae onto the polystyrenic macroporous resin Purolite (R) A-109 for better utilisation of its transglactosylation activity and application in galacto-oligosaccharide (GOS) synthesis. This was achieved by improving simple ionic adsorption by carboxyl group activation on the enzyme surface with carbodiimide, enabling covalent immobilisation. This yielded significantly increased operational stability, assayed as GOS synthesis, in a batch reactor, and even more prominently, in a fluidised bed reactor (73% activity retained after 10 cycles). The immobilised enzyme showed two very beneficial advantages over the free enzyme for future applications: higher affinity towards catalysing transgalactosylation than towards hydrolysis and shift of pH optimum towards more acidic conditions. GOS synthesis performed under the optimum conditions obtained (400 g L-1 lactose, pH 4.5, 50 degrees C) yielded 87 g L-1 and 100 g L-1 for batch and fluidised bed reactors, respectively.
PB  - Elsevier Sci Ltd, Oxford
T2  - International Dairy Journal
T1  - Galacto-oligosaccharide synthesis using chemically modified beta-galactosidase from Aspergillus oryzae immobilised onto macroporous amino resin
EP  - 57
SP  - 50
VL  - 54
DO  - 10.1016/j.idairyj.2015.10.002
ER  - 

@article{
author = "Simović, Milica and Ćorović, Marija and Mihailović, Mladen and Banjanac, Katarina and Milivojević, Ana and Veličković, Dušan and Bezbradica, Dejan",
year = "2016",
abstract = "The goal of this study was to establish an efficient immobilisation protocol for beta-galactosidase from Aspergillus oryzae onto the polystyrenic macroporous resin Purolite (R) A-109 for better utilisation of its transglactosylation activity and application in galacto-oligosaccharide (GOS) synthesis. This was achieved by improving simple ionic adsorption by carboxyl group activation on the enzyme surface with carbodiimide, enabling covalent immobilisation. This yielded significantly increased operational stability, assayed as GOS synthesis, in a batch reactor, and even more prominently, in a fluidised bed reactor (73% activity retained after 10 cycles). The immobilised enzyme showed two very beneficial advantages over the free enzyme for future applications: higher affinity towards catalysing transgalactosylation than towards hydrolysis and shift of pH optimum towards more acidic conditions. GOS synthesis performed under the optimum conditions obtained (400 g L-1 lactose, pH 4.5, 50 degrees C) yielded 87 g L-1 and 100 g L-1 for batch and fluidised bed reactors, respectively.",
publisher = "Elsevier Sci Ltd, Oxford",
journal = "International Dairy Journal",
title = "Galacto-oligosaccharide synthesis using chemically modified beta-galactosidase from Aspergillus oryzae immobilised onto macroporous amino resin",
pages = "57-50",
volume = "54",
doi = "10.1016/j.idairyj.2015.10.002"
}

Simović, M., Ćorović, M., Mihailović, M., Banjanac, K., Milivojević, A., Veličković, D.,& Bezbradica, D.. (2016). Galacto-oligosaccharide synthesis using chemically modified beta-galactosidase from Aspergillus oryzae immobilised onto macroporous amino resin. in International Dairy Journal
Elsevier Sci Ltd, Oxford., 54, 50-57.
https://doi.org/10.1016/j.idairyj.2015.10.002

Simović M, Ćorović M, Mihailović M, Banjanac K, Milivojević A, Veličković D, Bezbradica D. Galacto-oligosaccharide synthesis using chemically modified beta-galactosidase from Aspergillus oryzae immobilised onto macroporous amino resin. in International Dairy Journal. 2016;54:50-57.
doi:10.1016/j.idairyj.2015.10.002 .

Simović, Milica, Ćorović, Marija, Mihailović, Mladen, Banjanac, Katarina, Milivojević, Ana, Veličković, Dušan, Bezbradica, Dejan, "Galacto-oligosaccharide synthesis using chemically modified beta-galactosidase from Aspergillus oryzae immobilised onto macroporous amino resin" in International Dairy Journal, 54 (2016):50-57,
https://doi.org/10.1016/j.idairyj.2015.10.002 . .

TY  - JOUR
AU  - Mihailović, Mladen
AU  - Trbojević-Ivić, Jovana
AU  - Banjanac, Katarina
AU  - Milosavić, Nenad
AU  - Veličković, Dušan
AU  - Simović, Milica
AU  - Bezbradica, Dejan
PY  - 2016
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/3422
AB  - In this study, two commercial supports (Eupergit (R) C and Purolite (R) A109) were chemically modified in order to introduce thiosulfonate groups, which could subsequently exclusively react with the cysteine residues on the surface of enzymes. Thereafter, the maltase from Saccharomyces cerevisiae was immobilized onto the obtained thiosulfonate-activated supports, resulting in high expressed enzymatic activities (around 50 %), while on the other hand, immobilization on unmodified supports yielded expressed activities less than 5 %. Moreover, protein loadings up to 12.3 mg g(-1) and immobilized activities up to 3580 IU g(-1) were achieved by employment of these thiosulfonate supports. Desorption experiments, performed on samples taken during immobilization, proved that immobilization on the thiosulfonate supports was the first step of fast adsorption onto the supports and the formation of covalent bonds between the thiosulfonate groups and the thiol groups of cysteine represented a second slower step. More importantly, although enzyme coupling occurred via covalent bond formation, the performed immobilization proved to be reversible, since it was shown that 95 % of the immobilized activity could be detached from the support after treatment with a thiol reagent (beta-mercaptoethanol). Thus, the support could be reused after enzyme inactivation.
PB  - Srpsko hemijsko društvo, Beograd
T2  - Journal of the Serbian Chemical Society
T1  - Immobilization of maltase from Saccharomyces cerevisiae on thiosulfonate supports
EP  - 1382
IS  - 12
SP  - 1371
VL  - 81
DO  - 10.2298/JSC160730099M
ER  - 

@article{
author = "Mihailović, Mladen and Trbojević-Ivić, Jovana and Banjanac, Katarina and Milosavić, Nenad and Veličković, Dušan and Simović, Milica and Bezbradica, Dejan",
year = "2016",
abstract = "In this study, two commercial supports (Eupergit (R) C and Purolite (R) A109) were chemically modified in order to introduce thiosulfonate groups, which could subsequently exclusively react with the cysteine residues on the surface of enzymes. Thereafter, the maltase from Saccharomyces cerevisiae was immobilized onto the obtained thiosulfonate-activated supports, resulting in high expressed enzymatic activities (around 50 %), while on the other hand, immobilization on unmodified supports yielded expressed activities less than 5 %. Moreover, protein loadings up to 12.3 mg g(-1) and immobilized activities up to 3580 IU g(-1) were achieved by employment of these thiosulfonate supports. Desorption experiments, performed on samples taken during immobilization, proved that immobilization on the thiosulfonate supports was the first step of fast adsorption onto the supports and the formation of covalent bonds between the thiosulfonate groups and the thiol groups of cysteine represented a second slower step. More importantly, although enzyme coupling occurred via covalent bond formation, the performed immobilization proved to be reversible, since it was shown that 95 % of the immobilized activity could be detached from the support after treatment with a thiol reagent (beta-mercaptoethanol). Thus, the support could be reused after enzyme inactivation.",
publisher = "Srpsko hemijsko društvo, Beograd",
journal = "Journal of the Serbian Chemical Society",
title = "Immobilization of maltase from Saccharomyces cerevisiae on thiosulfonate supports",
pages = "1382-1371",
number = "12",
volume = "81",
doi = "10.2298/JSC160730099M"
}

Mihailović, M., Trbojević-Ivić, J., Banjanac, K., Milosavić, N., Veličković, D., Simović, M.,& Bezbradica, D.. (2016). Immobilization of maltase from Saccharomyces cerevisiae on thiosulfonate supports. in Journal of the Serbian Chemical Society
Srpsko hemijsko društvo, Beograd., 81(12), 1371-1382.
https://doi.org/10.2298/JSC160730099M

Mihailović M, Trbojević-Ivić J, Banjanac K, Milosavić N, Veličković D, Simović M, Bezbradica D. Immobilization of maltase from Saccharomyces cerevisiae on thiosulfonate supports. in Journal of the Serbian Chemical Society. 2016;81(12):1371-1382.
doi:10.2298/JSC160730099M .

Mihailović, Mladen, Trbojević-Ivić, Jovana, Banjanac, Katarina, Milosavić, Nenad, Veličković, Dušan, Simović, Milica, Bezbradica, Dejan, "Immobilization of maltase from Saccharomyces cerevisiae on thiosulfonate supports" in Journal of the Serbian Chemical Society, 81, no. 12 (2016):1371-1382,
https://doi.org/10.2298/JSC160730099M . .

TY  - JOUR
AU  - Banjanac, Katarina
AU  - Mihailović, Mladen
AU  - Prlainović, Nevena
AU  - Ćorović, Marija
AU  - Simović, Milica
AU  - Marinković, Aleksandar
AU  - Bezbradica, Dejan
PY  - 2016
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/3323
AB  - BACKGROUND: In this study, in order to obtain the best support for the immobilization of lipase from Candida rugosa (CRL), the procedure for chemical modification of fumed silica nanoparticles (FNS) with (3-Glycidyloxypropyl) trimethoxysilane (GOPTMS) was optimized by varying the amount of GOPTMS used and the duration of support modification. To evaluate the prospects of chemical modification of FNS surface on the immobilization process, the activity and thermal stability of lipase immobilized on GFNS was compared with lipase immobilized on FNS and cyanuric chloride functionalized amino silica (CCAFNS). RESULTS: The epoxy functionalized silica nanoparticles (GFNS) with 400-500 mu mol of introduced epoxy groups per g of support were the most efficient, since immobilized preparations in 1 mol L-1 buffer had the highest activity of approximately 1495 IU g(-1) and a loading capacity of 294 mg g(-1). Lipase immobilized on GFNS exhibited 1.5-fold higher hydrolytic activity and 2-fold higher esterification activity in the synthesis of aroma esters than lipase immobilized on CCAFNS, while its thermal stability was similar to CCAFNS preparations. CONCLUSION: These results indicated that the type of modification of the FNS surface has an influence on the specificity of the immobilized lipase, since lipase immobilized on GFNS showed improved properties for ester synthesis which is a promising area for immobilized lipase application.
PB  - Wiley, Hoboken
T2  - Journal of Chemical Technology and Biotechnology
T1  - Epoxy-silanization - tool for improvement of silica nanoparticles as support for lipase immobilization with respect to esterification activity
EP  - 2663
IS  - 10
SP  - 2654
VL  - 91
DO  - 10.1002/jctb.4870
ER  - 

@article{
author = "Banjanac, Katarina and Mihailović, Mladen and Prlainović, Nevena and Ćorović, Marija and Simović, Milica and Marinković, Aleksandar and Bezbradica, Dejan",
year = "2016",
abstract = "BACKGROUND: In this study, in order to obtain the best support for the immobilization of lipase from Candida rugosa (CRL), the procedure for chemical modification of fumed silica nanoparticles (FNS) with (3-Glycidyloxypropyl) trimethoxysilane (GOPTMS) was optimized by varying the amount of GOPTMS used and the duration of support modification. To evaluate the prospects of chemical modification of FNS surface on the immobilization process, the activity and thermal stability of lipase immobilized on GFNS was compared with lipase immobilized on FNS and cyanuric chloride functionalized amino silica (CCAFNS). RESULTS: The epoxy functionalized silica nanoparticles (GFNS) with 400-500 mu mol of introduced epoxy groups per g of support were the most efficient, since immobilized preparations in 1 mol L-1 buffer had the highest activity of approximately 1495 IU g(-1) and a loading capacity of 294 mg g(-1). Lipase immobilized on GFNS exhibited 1.5-fold higher hydrolytic activity and 2-fold higher esterification activity in the synthesis of aroma esters than lipase immobilized on CCAFNS, while its thermal stability was similar to CCAFNS preparations. CONCLUSION: These results indicated that the type of modification of the FNS surface has an influence on the specificity of the immobilized lipase, since lipase immobilized on GFNS showed improved properties for ester synthesis which is a promising area for immobilized lipase application.",
publisher = "Wiley, Hoboken",
journal = "Journal of Chemical Technology and Biotechnology",
title = "Epoxy-silanization - tool for improvement of silica nanoparticles as support for lipase immobilization with respect to esterification activity",
pages = "2663-2654",
number = "10",
volume = "91",
doi = "10.1002/jctb.4870"
}

Banjanac, K., Mihailović, M., Prlainović, N., Ćorović, M., Simović, M., Marinković, A.,& Bezbradica, D.. (2016). Epoxy-silanization - tool for improvement of silica nanoparticles as support for lipase immobilization with respect to esterification activity. in Journal of Chemical Technology and Biotechnology
Wiley, Hoboken., 91(10), 2654-2663.
https://doi.org/10.1002/jctb.4870

Banjanac K, Mihailović M, Prlainović N, Ćorović M, Simović M, Marinković A, Bezbradica D. Epoxy-silanization - tool for improvement of silica nanoparticles as support for lipase immobilization with respect to esterification activity. in Journal of Chemical Technology and Biotechnology. 2016;91(10):2654-2663.
doi:10.1002/jctb.4870 .

Banjanac, Katarina, Mihailović, Mladen, Prlainović, Nevena, Ćorović, Marija, Simović, Milica, Marinković, Aleksandar, Bezbradica, Dejan, "Epoxy-silanization - tool for improvement of silica nanoparticles as support for lipase immobilization with respect to esterification activity" in Journal of Chemical Technology and Biotechnology, 91, no. 10 (2016):2654-2663,
https://doi.org/10.1002/jctb.4870 . .

TY  - JOUR
AU  - Banjanac, Katarina
AU  - Mihailović, Mladen
AU  - Prlainović, Nevena
AU  - Stojanović, Marija
AU  - Simović, Milica
AU  - Marinković, Aleksandar
AU  - Bezbradica, Dejan
PY  - 2016
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/3372
AB  - BACKGROUNDIn this work, fumed nano-silica (FNS) was chemically modified to amino (AFNS) and subsequently to cyanuric chloride (CCAFNS) modified silica and tested for the immobilization of lipase from Candida rugosa (CRL). The effects of the initial enzyme concentration, immobilization time and buffer ionic strength on immobilization were investigated in order to optimize utilization of the support and determine the mechanism of immobilization. The most active preparations were used to examine thermal and operational stability. RESULTSThe amount of immobilized enzyme increased with increasing enzyme concentration, achieving loadings of 121.3, 104.8 and 61.2mg per g of FNS, CCAFNS and AFNS, respectively. Lipase immobilized on CCAFNS carrier in 0.1molL(-1) buffer expressed the highest lipolytic activity (1320 IU g(-1) support), while more stable preparations were obtained in 1molL(-1) buffer. CONCLUSIONSuccessful modification of silica was confirmed with Fourier transform infrared spectroscopy and thermogravimetric analysis. Activity results showed that, depending on the support, immobilization was governed by different interactions. On FNS and AFNS immobilization was exclusively by adsorption, while on CCAFNS after the initial adsorption lipase molecules reoriented and amino groups of the enzyme formed a covalent bond with the chlorine atom of the modified carrier. Improved thermal and operational stability of lipase immobilized on CCAFNS in 1molL(-1) buffer led to the conclusion that electrostatic interactions have a great role in the immobilization.
PB  - Wiley-Blackwell, Hoboken
T2  - Journal of Chemical Technology and Biotechnology
T1  - Cyanuric chloride functionalized silica nanoparticles for covalent immobilization of lipase
EP  - 448
IS  - 2
SP  - 439
VL  - 91
DO  - 10.1002/jctb.4595
ER  - 

@article{
author = "Banjanac, Katarina and Mihailović, Mladen and Prlainović, Nevena and Stojanović, Marija and Simović, Milica and Marinković, Aleksandar and Bezbradica, Dejan",
year = "2016",
abstract = "BACKGROUNDIn this work, fumed nano-silica (FNS) was chemically modified to amino (AFNS) and subsequently to cyanuric chloride (CCAFNS) modified silica and tested for the immobilization of lipase from Candida rugosa (CRL). The effects of the initial enzyme concentration, immobilization time and buffer ionic strength on immobilization were investigated in order to optimize utilization of the support and determine the mechanism of immobilization. The most active preparations were used to examine thermal and operational stability. RESULTSThe amount of immobilized enzyme increased with increasing enzyme concentration, achieving loadings of 121.3, 104.8 and 61.2mg per g of FNS, CCAFNS and AFNS, respectively. Lipase immobilized on CCAFNS carrier in 0.1molL(-1) buffer expressed the highest lipolytic activity (1320 IU g(-1) support), while more stable preparations were obtained in 1molL(-1) buffer. CONCLUSIONSuccessful modification of silica was confirmed with Fourier transform infrared spectroscopy and thermogravimetric analysis. Activity results showed that, depending on the support, immobilization was governed by different interactions. On FNS and AFNS immobilization was exclusively by adsorption, while on CCAFNS after the initial adsorption lipase molecules reoriented and amino groups of the enzyme formed a covalent bond with the chlorine atom of the modified carrier. Improved thermal and operational stability of lipase immobilized on CCAFNS in 1molL(-1) buffer led to the conclusion that electrostatic interactions have a great role in the immobilization.",
publisher = "Wiley-Blackwell, Hoboken",
journal = "Journal of Chemical Technology and Biotechnology",
title = "Cyanuric chloride functionalized silica nanoparticles for covalent immobilization of lipase",
pages = "448-439",
number = "2",
volume = "91",
doi = "10.1002/jctb.4595"
}

Banjanac, K., Mihailović, M., Prlainović, N., Stojanović, M., Simović, M., Marinković, A.,& Bezbradica, D.. (2016). Cyanuric chloride functionalized silica nanoparticles for covalent immobilization of lipase. in Journal of Chemical Technology and Biotechnology
Wiley-Blackwell, Hoboken., 91(2), 439-448.
https://doi.org/10.1002/jctb.4595

Banjanac K, Mihailović M, Prlainović N, Stojanović M, Simović M, Marinković A, Bezbradica D. Cyanuric chloride functionalized silica nanoparticles for covalent immobilization of lipase. in Journal of Chemical Technology and Biotechnology. 2016;91(2):439-448.
doi:10.1002/jctb.4595 .

Banjanac, Katarina, Mihailović, Mladen, Prlainović, Nevena, Stojanović, Marija, Simović, Milica, Marinković, Aleksandar, Bezbradica, Dejan, "Cyanuric chloride functionalized silica nanoparticles for covalent immobilization of lipase" in Journal of Chemical Technology and Biotechnology, 91, no. 2 (2016):439-448,
https://doi.org/10.1002/jctb.4595 . .

TY  - JOUR
AU  - Carević, Milica
AU  - Vukašinović-Sekulić, Maja
AU  - Grbavčić, Sanja
AU  - Stojanović, Marija
AU  - Mihailović, Mladen
AU  - Dimitrijević, Aleksandra
AU  - Bezbradica, Dejan
PY  - 2015
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2885
AB  - (-galactosidase, commonly known as lactase, represents commercially important enzyme that is prevalently used for lactose hydrolysis in milk and whey. To the date, it has been isolated from various sources. In this study different strains of lactic acid bacteria were assessed for their (-galactosidase productivity, and Lactobacillus acidophilus ATCC 4356 resulted with the highest production potential. Thereafter, optimal conditions for accomplishing high yields of (-galactosidase activity were determined. Maximal specific activity (1.01 IU mL-1) was accomplished after 2 days shake flask culture fermentation (150 rpm) at 37°C, with modified Man Rogosa Sharpe culture broth using lactose (2.5%) as sole carbon source. Finally, in order to intensify release of intracellular (-galactosidase different mechanical and chemical methods were conducted. Nevertheless, vortexing with quartz sand (150 μm) as abrasive was proven to be the most efficient method of cell disruption. The optimum temperature of obtained (-galactosidase was 45°C and the optimum range pH 6.5-7.5.
AB  - Enzim (-galaktozidaza, poznatija kao laktaza, predstavlja industrijski izuzetno važan enzim, koji ima primarnu ulogu u hidrolizi disaharida laktoze. Upotrebom ovog enzima u industriji mleka i mlečnih proizvoda dolazi do poboljšanja fizičkih i senzornih karakteristika proizvoda, kao i do povećanja svarljivosti proizvoda, a samim tim i prevazilaženja problema netolerancije na laktozu. Takođe, hidrolizom laktoze surutke, rešava se pitanje njenog ekološki prihvatljivog odlaganja. Sa druge strane, enzim pod kontrolisanim reakcionim uslovima može katalizovatii proces transgalaktozilacije, odnosno prenošenja galaktozil jedinica na druge šećere prisutne u sistemu (najčešće laktozu), pri čemu nastaju izuzetno važna funkcionalna jedinjenja galaktooligosaharidi. Enzim (-galaktozidaza može biti različitog porekla - biljnog, životinjskog ili mikrobnog. Međutim, najznačajniji među njima su mikrobni postupci proizvodnje, zbog lake fermentacije, velike brzine rasta i razmnožavanja ćelija, visokih prinosa, visoke aktivnosti, kao i stabilnosti enzima. Kao posledica velikog komercijalnog interesa za ovaj enzim, opisane su različite metode dobijanja i prečišćavanja dobijenih enzima iz različitih mikroorganizama. Poslednjih godina bakterije mlečne kiseline privlače sve više pažnje kao potencijalni izvori (-galaktozidaza najviše zahvaljujući svom statusu bezbednih za upotrebu u prehrambenoj i farmaceutskoj industriji, čime se omogućava neometano korišćenje enzima bez primene komplikovanih metoda prečišćavanja. U ovom radu ispitana je mogućnost proizvodnje (-galaktozidaza pomoću nekoliko vrsta bakterija mlečne kiseline. Kao najbolji producent među ispitanim bakterijama pokazala se bakterija Lactobacillus acidophilus. Najveća aktivnost (-galaktozidaze, dobijena je mikroaerofilnom fermentacijom u modifikovanoj komercijalnoj MRS podlozi, sa 2,5% laktoze kao jedinim izvorom ugljenika. Fermentacija je vršena na tresilici (150 rpm) u trajanju od 48 h i na temperaturi od 37°C. Kako je enzim intracelularan, u cilju razaranja ćelija i oslobađanja enzima, primenjeno je više različitih fizičkih i hemijskih metoda, a daleko najboljom pokazala se metoda vorteksiranja sa kvarcnim peskom (150 μm) kao abrazivnim sredstvom. Ovako dobijen enzim pokazao je maksimalnu aktivnost pri temperaturi od 45°C i pH u opsegu 6.5-7.5.
PB  - Association of Chemical Engineers of Serbia
T2  - Hemijska industrija
T1  - Optimization of (-galactosidase production from lactic acid bacteria
T1  - Optimizacija proizvodnje (-galaktozidaze pomoću bakterija mlečne kiseline
EP  - 312
IS  - 3
SP  - 305
VL  - 69
DO  - 10.2298/HEMIND140303044C
ER  - 

@article{
author = "Carević, Milica and Vukašinović-Sekulić, Maja and Grbavčić, Sanja and Stojanović, Marija and Mihailović, Mladen and Dimitrijević, Aleksandra and Bezbradica, Dejan",
year = "2015",
abstract = "(-galactosidase, commonly known as lactase, represents commercially important enzyme that is prevalently used for lactose hydrolysis in milk and whey. To the date, it has been isolated from various sources. In this study different strains of lactic acid bacteria were assessed for their (-galactosidase productivity, and Lactobacillus acidophilus ATCC 4356 resulted with the highest production potential. Thereafter, optimal conditions for accomplishing high yields of (-galactosidase activity were determined. Maximal specific activity (1.01 IU mL-1) was accomplished after 2 days shake flask culture fermentation (150 rpm) at 37°C, with modified Man Rogosa Sharpe culture broth using lactose (2.5%) as sole carbon source. Finally, in order to intensify release of intracellular (-galactosidase different mechanical and chemical methods were conducted. Nevertheless, vortexing with quartz sand (150 μm) as abrasive was proven to be the most efficient method of cell disruption. The optimum temperature of obtained (-galactosidase was 45°C and the optimum range pH 6.5-7.5., Enzim (-galaktozidaza, poznatija kao laktaza, predstavlja industrijski izuzetno važan enzim, koji ima primarnu ulogu u hidrolizi disaharida laktoze. Upotrebom ovog enzima u industriji mleka i mlečnih proizvoda dolazi do poboljšanja fizičkih i senzornih karakteristika proizvoda, kao i do povećanja svarljivosti proizvoda, a samim tim i prevazilaženja problema netolerancije na laktozu. Takođe, hidrolizom laktoze surutke, rešava se pitanje njenog ekološki prihvatljivog odlaganja. Sa druge strane, enzim pod kontrolisanim reakcionim uslovima može katalizovatii proces transgalaktozilacije, odnosno prenošenja galaktozil jedinica na druge šećere prisutne u sistemu (najčešće laktozu), pri čemu nastaju izuzetno važna funkcionalna jedinjenja galaktooligosaharidi. Enzim (-galaktozidaza može biti različitog porekla - biljnog, životinjskog ili mikrobnog. Međutim, najznačajniji među njima su mikrobni postupci proizvodnje, zbog lake fermentacije, velike brzine rasta i razmnožavanja ćelija, visokih prinosa, visoke aktivnosti, kao i stabilnosti enzima. Kao posledica velikog komercijalnog interesa za ovaj enzim, opisane su različite metode dobijanja i prečišćavanja dobijenih enzima iz različitih mikroorganizama. Poslednjih godina bakterije mlečne kiseline privlače sve više pažnje kao potencijalni izvori (-galaktozidaza najviše zahvaljujući svom statusu bezbednih za upotrebu u prehrambenoj i farmaceutskoj industriji, čime se omogućava neometano korišćenje enzima bez primene komplikovanih metoda prečišćavanja. U ovom radu ispitana je mogućnost proizvodnje (-galaktozidaza pomoću nekoliko vrsta bakterija mlečne kiseline. Kao najbolji producent među ispitanim bakterijama pokazala se bakterija Lactobacillus acidophilus. Najveća aktivnost (-galaktozidaze, dobijena je mikroaerofilnom fermentacijom u modifikovanoj komercijalnoj MRS podlozi, sa 2,5% laktoze kao jedinim izvorom ugljenika. Fermentacija je vršena na tresilici (150 rpm) u trajanju od 48 h i na temperaturi od 37°C. Kako je enzim intracelularan, u cilju razaranja ćelija i oslobađanja enzima, primenjeno je više različitih fizičkih i hemijskih metoda, a daleko najboljom pokazala se metoda vorteksiranja sa kvarcnim peskom (150 μm) kao abrazivnim sredstvom. Ovako dobijen enzim pokazao je maksimalnu aktivnost pri temperaturi od 45°C i pH u opsegu 6.5-7.5.",
publisher = "Association of Chemical Engineers of Serbia",
journal = "Hemijska industrija",
title = "Optimization of (-galactosidase production from lactic acid bacteria, Optimizacija proizvodnje (-galaktozidaze pomoću bakterija mlečne kiseline",
pages = "312-305",
number = "3",
volume = "69",
doi = "10.2298/HEMIND140303044C"
}

Carević, M., Vukašinović-Sekulić, M., Grbavčić, S., Stojanović, M., Mihailović, M., Dimitrijević, A.,& Bezbradica, D.. (2015). Optimization of (-galactosidase production from lactic acid bacteria. in Hemijska industrija
Association of Chemical Engineers of Serbia., 69(3), 305-312.
https://doi.org/10.2298/HEMIND140303044C

Carević M, Vukašinović-Sekulić M, Grbavčić S, Stojanović M, Mihailović M, Dimitrijević A, Bezbradica D. Optimization of (-galactosidase production from lactic acid bacteria. in Hemijska industrija. 2015;69(3):305-312.
doi:10.2298/HEMIND140303044C .

Carević, Milica, Vukašinović-Sekulić, Maja, Grbavčić, Sanja, Stojanović, Marija, Mihailović, Mladen, Dimitrijević, Aleksandra, Bezbradica, Dejan, "Optimization of (-galactosidase production from lactic acid bacteria" in Hemijska industrija, 69, no. 3 (2015):305-312,
https://doi.org/10.2298/HEMIND140303044C . .

TY  - JOUR
AU  - Stojanović, Marija
AU  - Simović, Milica
AU  - Mihailović, Mladen
AU  - Veličković, Dušan
AU  - Dimitrijević, Aleksandra
AU  - Milosavić, Nenad
AU  - Bezbradica, Dejan
PY  - 2015
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4720
AB  - Fatty acid (FA) ascorbyl esters are recently emerging food, cosmetic, and pharmaceutical additives, which can be prepared in an eco-friendly way by using lipases as catalysts. Because they are amphiphilic molecules, which possess high free radical scavenging capacity, they can be applied as liposoluble antioxidants as well as emulsifiers and biosurfactants. In this study, the influence of a wide range of acyl donors on ester yield in lipase-catalyzed synthesis and ester antioxidant activity was examined. Among saturated acyl donors, higher yields and antioxidant activities of esters were achieved when short-chain FAs were used. Oleic acid gave the highest yield overall and its ester exhibited a high antioxidant activity. Optimization of experimental factors showed that the highest conversion (60.5%) in acetone was achieved with 5 g L-1 of lipase, 50 mM of vitamin C, 10-fold molar excess of oleic acid, and 0.7 mL L-1 of initial water. Obtained results showed that even short- and medium-chain ascorbyl esters could be synthesized with high yields and retained (or even exceeded) free radical scavenging capacity of l-ascorbic acid, indicating prospects of broadening their application in emulsions and liposomes.
PB  - Wiley, Hoboken
T2  - Biotechnology and Applied Biochemistry
T1  - Influence of fatty acid on lipase-catalyzed synthesis of ascorbyl esters and their free radical scavenging capacity
EP  - 466
IS  - 4
SP  - 458
VL  - 62
DO  - 10.1002/bab.1296
ER  - 

@article{
author = "Stojanović, Marija and Simović, Milica and Mihailović, Mladen and Veličković, Dušan and Dimitrijević, Aleksandra and Milosavić, Nenad and Bezbradica, Dejan",
year = "2015",
abstract = "Fatty acid (FA) ascorbyl esters are recently emerging food, cosmetic, and pharmaceutical additives, which can be prepared in an eco-friendly way by using lipases as catalysts. Because they are amphiphilic molecules, which possess high free radical scavenging capacity, they can be applied as liposoluble antioxidants as well as emulsifiers and biosurfactants. In this study, the influence of a wide range of acyl donors on ester yield in lipase-catalyzed synthesis and ester antioxidant activity was examined. Among saturated acyl donors, higher yields and antioxidant activities of esters were achieved when short-chain FAs were used. Oleic acid gave the highest yield overall and its ester exhibited a high antioxidant activity. Optimization of experimental factors showed that the highest conversion (60.5%) in acetone was achieved with 5 g L-1 of lipase, 50 mM of vitamin C, 10-fold molar excess of oleic acid, and 0.7 mL L-1 of initial water. Obtained results showed that even short- and medium-chain ascorbyl esters could be synthesized with high yields and retained (or even exceeded) free radical scavenging capacity of l-ascorbic acid, indicating prospects of broadening their application in emulsions and liposomes.",
publisher = "Wiley, Hoboken",
journal = "Biotechnology and Applied Biochemistry",
title = "Influence of fatty acid on lipase-catalyzed synthesis of ascorbyl esters and their free radical scavenging capacity",
pages = "466-458",
number = "4",
volume = "62",
doi = "10.1002/bab.1296"
}

Stojanović, M., Simović, M., Mihailović, M., Veličković, D., Dimitrijević, A., Milosavić, N.,& Bezbradica, D.. (2015). Influence of fatty acid on lipase-catalyzed synthesis of ascorbyl esters and their free radical scavenging capacity. in Biotechnology and Applied Biochemistry
Wiley, Hoboken., 62(4), 458-466.
https://doi.org/10.1002/bab.1296

Stojanović M, Simović M, Mihailović M, Veličković D, Dimitrijević A, Milosavić N, Bezbradica D. Influence of fatty acid on lipase-catalyzed synthesis of ascorbyl esters and their free radical scavenging capacity. in Biotechnology and Applied Biochemistry. 2015;62(4):458-466.
doi:10.1002/bab.1296 .

Stojanović, Marija, Simović, Milica, Mihailović, Mladen, Veličković, Dušan, Dimitrijević, Aleksandra, Milosavić, Nenad, Bezbradica, Dejan, "Influence of fatty acid on lipase-catalyzed synthesis of ascorbyl esters and their free radical scavenging capacity" in Biotechnology and Applied Biochemistry, 62, no. 4 (2015):458-466,
https://doi.org/10.1002/bab.1296 . .

TY  - JOUR
AU  - Stojanović, Marija
AU  - Simović, Milica
AU  - Mihailović, Mladen
AU  - Veličković, Dušan
AU  - Dimitrijević, Aleksandra
AU  - Milosavić, Nenad
AU  - Bezbradica, Dejan
PY  - 2015
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/3146
AB  - Fatty acid (FA) ascorbyl esters are recently emerging food, cosmetic, and pharmaceutical additives, which can be prepared in an eco-friendly way by using lipases as catalysts. Because they are amphiphilic molecules, which possess high free radical scavenging capacity, they can be applied as liposoluble antioxidants as well as emulsifiers and biosurfactants. In this study, the influence of a wide range of acyl donors on ester yield in lipase-catalyzed synthesis and ester antioxidant activity was examined. Among saturated acyl donors, higher yields and antioxidant activities of esters were achieved when short-chain FAs were used. Oleic acid gave the highest yield overall and its ester exhibited a high antioxidant activity. Optimization of experimental factors showed that the highest conversion (60.5%) in acetone was achieved with 5 g L-1 of lipase, 50 mM of vitamin C, 10-fold molar excess of oleic acid, and 0.7 mL L-1 of initial water. Obtained results showed that even short- and medium-chain ascorbyl esters could be synthesized with high yields and retained (or even exceeded) free radical scavenging capacity of l-ascorbic acid, indicating prospects of broadening their application in emulsions and liposomes.
PB  - Wiley, Hoboken
T2  - Biotechnology and Applied Biochemistry
T1  - Influence of fatty acid on lipase-catalyzed synthesis of ascorbyl esters and their free radical scavenging capacity
EP  - 466
IS  - 4
SP  - 458
VL  - 62
DO  - 10.1002/bab.1296
ER  - 

@article{
author = "Stojanović, Marija and Simović, Milica and Mihailović, Mladen and Veličković, Dušan and Dimitrijević, Aleksandra and Milosavić, Nenad and Bezbradica, Dejan",
year = "2015",
abstract = "Fatty acid (FA) ascorbyl esters are recently emerging food, cosmetic, and pharmaceutical additives, which can be prepared in an eco-friendly way by using lipases as catalysts. Because they are amphiphilic molecules, which possess high free radical scavenging capacity, they can be applied as liposoluble antioxidants as well as emulsifiers and biosurfactants. In this study, the influence of a wide range of acyl donors on ester yield in lipase-catalyzed synthesis and ester antioxidant activity was examined. Among saturated acyl donors, higher yields and antioxidant activities of esters were achieved when short-chain FAs were used. Oleic acid gave the highest yield overall and its ester exhibited a high antioxidant activity. Optimization of experimental factors showed that the highest conversion (60.5%) in acetone was achieved with 5 g L-1 of lipase, 50 mM of vitamin C, 10-fold molar excess of oleic acid, and 0.7 mL L-1 of initial water. Obtained results showed that even short- and medium-chain ascorbyl esters could be synthesized with high yields and retained (or even exceeded) free radical scavenging capacity of l-ascorbic acid, indicating prospects of broadening their application in emulsions and liposomes.",
publisher = "Wiley, Hoboken",
journal = "Biotechnology and Applied Biochemistry",
title = "Influence of fatty acid on lipase-catalyzed synthesis of ascorbyl esters and their free radical scavenging capacity",
pages = "466-458",
number = "4",
volume = "62",
doi = "10.1002/bab.1296"
}

Stojanović, M., Simović, M., Mihailović, M., Veličković, D., Dimitrijević, A., Milosavić, N.,& Bezbradica, D.. (2015). Influence of fatty acid on lipase-catalyzed synthesis of ascorbyl esters and their free radical scavenging capacity. in Biotechnology and Applied Biochemistry
Wiley, Hoboken., 62(4), 458-466.
https://doi.org/10.1002/bab.1296

Stojanović M, Simović M, Mihailović M, Veličković D, Dimitrijević A, Milosavić N, Bezbradica D. Influence of fatty acid on lipase-catalyzed synthesis of ascorbyl esters and their free radical scavenging capacity. in Biotechnology and Applied Biochemistry. 2015;62(4):458-466.
doi:10.1002/bab.1296 .

Stojanović, Marija, Simović, Milica, Mihailović, Mladen, Veličković, Dušan, Dimitrijević, Aleksandra, Milosavić, Nenad, Bezbradica, Dejan, "Influence of fatty acid on lipase-catalyzed synthesis of ascorbyl esters and their free radical scavenging capacity" in Biotechnology and Applied Biochemistry, 62, no. 4 (2015):458-466,
https://doi.org/10.1002/bab.1296 . .

TY  - JOUR
AU  - Milivojević, Ana
AU  - Stojanović, Marija
AU  - Carević, Milica
AU  - Mihailović, Mladen
AU  - Veličković, Dušan
AU  - Milosavić, Nenad
AU  - Bezbradica, Dejan
PY  - 2014
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2744
AB  - Lipase-catalyzed acylation of phloridzin with a wide range of fatty acids and antioxidant activities of synthesized esters were investigated in this study. Polar solvents were suitable reaction media for esterification, and the highest yield was achieved in acetonitrile. By using statistically designed optimization of key experimental factors for the synthesis of phloridzil oleate as the model reaction, great improvements in achieved conversion and yield per enzyme mass were enabled. The most significant progress has been made in the cost-effectiveness of the reaction, since the specific yield of 5.45 mmol g(-1) was obtained at 58 degrees C, with 0.09 M phloridzin, 1.17 M oleic acid, and only 0.5% (w/v) biocatalyst. All examined fatty acids were suitable acyl donors, since the chain length and unsaturation degree had slight effects on esterification and all products yielded over 70%. Phloridzil caprate, myristate, and oleate exhibited the highest antioxidant activities among the obtained esters.
PB  - Amer Chemical Soc, Washington
T2  - Industrial & Engineering Chemistry Research
T1  - Lipase-Catalyzed Esterification of Phloridzin: Acyl Donor Effect on Enzymatic Affinity and Antioxidant Properties of Esters
EP  - 16651
IS  - 43
SP  - 16644
VL  - 53
DO  - 10.1021/ie5027259
ER  - 

@article{
author = "Milivojević, Ana and Stojanović, Marija and Carević, Milica and Mihailović, Mladen and Veličković, Dušan and Milosavić, Nenad and Bezbradica, Dejan",
year = "2014",
abstract = "Lipase-catalyzed acylation of phloridzin with a wide range of fatty acids and antioxidant activities of synthesized esters were investigated in this study. Polar solvents were suitable reaction media for esterification, and the highest yield was achieved in acetonitrile. By using statistically designed optimization of key experimental factors for the synthesis of phloridzil oleate as the model reaction, great improvements in achieved conversion and yield per enzyme mass were enabled. The most significant progress has been made in the cost-effectiveness of the reaction, since the specific yield of 5.45 mmol g(-1) was obtained at 58 degrees C, with 0.09 M phloridzin, 1.17 M oleic acid, and only 0.5% (w/v) biocatalyst. All examined fatty acids were suitable acyl donors, since the chain length and unsaturation degree had slight effects on esterification and all products yielded over 70%. Phloridzil caprate, myristate, and oleate exhibited the highest antioxidant activities among the obtained esters.",
publisher = "Amer Chemical Soc, Washington",
journal = "Industrial & Engineering Chemistry Research",
title = "Lipase-Catalyzed Esterification of Phloridzin: Acyl Donor Effect on Enzymatic Affinity and Antioxidant Properties of Esters",
pages = "16651-16644",
number = "43",
volume = "53",
doi = "10.1021/ie5027259"
}

Milivojević, A., Stojanović, M., Carević, M., Mihailović, M., Veličković, D., Milosavić, N.,& Bezbradica, D.. (2014). Lipase-Catalyzed Esterification of Phloridzin: Acyl Donor Effect on Enzymatic Affinity and Antioxidant Properties of Esters. in Industrial & Engineering Chemistry Research
Amer Chemical Soc, Washington., 53(43), 16644-16651.
https://doi.org/10.1021/ie5027259

Milivojević A, Stojanović M, Carević M, Mihailović M, Veličković D, Milosavić N, Bezbradica D. Lipase-Catalyzed Esterification of Phloridzin: Acyl Donor Effect on Enzymatic Affinity and Antioxidant Properties of Esters. in Industrial & Engineering Chemistry Research. 2014;53(43):16644-16651.
doi:10.1021/ie5027259 .

Milivojević, Ana, Stojanović, Marija, Carević, Milica, Mihailović, Mladen, Veličković, Dušan, Milosavić, Nenad, Bezbradica, Dejan, "Lipase-Catalyzed Esterification of Phloridzin: Acyl Donor Effect on Enzymatic Affinity and Antioxidant Properties of Esters" in Industrial & Engineering Chemistry Research, 53, no. 43 (2014):16644-16651,
https://doi.org/10.1021/ie5027259 . .

TY  - JOUR
AU  - Mihailović, Mladen
AU  - Stojanović, Marija
AU  - Banjanac, Katarina
AU  - Carević, Milica
AU  - Prlainović, Nevena
AU  - Milosavić, Nenad
AU  - Bezbradica, Dejan
PY  - 2014
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2853
AB  - In this study, Purolite (R) A109, polystyrenic macroporous resin, was used as immobilization support due to its good mechanical properties and high particle diameter (400 mu m), which enables efficient application in enzyme reactors due to lower pressure drops. The surface of support had been modified with epichlorhydrine and was tested in lipase immobilization. Optimized procedure for support modification proved to be more efficient than conventional procedure for hydroxy groups (at 22 degrees C for 18 h), since duration of procedure was shortened to 40 min by performing modification at 52 degrees C resulting with almost doubled concentration of epoxy groups (563 mu mol g(-1)). Lipase immobilized on epoxy-modified support showed significantly improved thermal stability comparing to both, free form and commercial immobilized preparation (Novozym (R) 435). The highest activity (47.5 IU g(-1)) and thermal stability (2.5 times higher half-life than at low ionic strength) were obtained with lipase immobilized in high ionic strength. Thermal stability of immobilized lipase was further improved by blocking unreacted epoxy groups on supports surface with amino acids. The most efficient was treatment with phenylalanine, since in such a way blocked immobilized enzyme retained 65% of initial activity after 8 h incubation at 65 degrees C, while non-blocked derivative retained 12%.
PB  - Elsevier Sci Ltd, Oxford
T2  - Process Biochemistry
T1  - Immobilization of lipase on epoxy-activated Purolite((R)) A109 and its post-immobilization stabilization
EP  - 646
IS  - 4
SP  - 637
VL  - 49
DO  - 10.1016/j.procbio.2014.01.013
ER  - 

@article{
author = "Mihailović, Mladen and Stojanović, Marija and Banjanac, Katarina and Carević, Milica and Prlainović, Nevena and Milosavić, Nenad and Bezbradica, Dejan",
year = "2014",
abstract = "In this study, Purolite (R) A109, polystyrenic macroporous resin, was used as immobilization support due to its good mechanical properties and high particle diameter (400 mu m), which enables efficient application in enzyme reactors due to lower pressure drops. The surface of support had been modified with epichlorhydrine and was tested in lipase immobilization. Optimized procedure for support modification proved to be more efficient than conventional procedure for hydroxy groups (at 22 degrees C for 18 h), since duration of procedure was shortened to 40 min by performing modification at 52 degrees C resulting with almost doubled concentration of epoxy groups (563 mu mol g(-1)). Lipase immobilized on epoxy-modified support showed significantly improved thermal stability comparing to both, free form and commercial immobilized preparation (Novozym (R) 435). The highest activity (47.5 IU g(-1)) and thermal stability (2.5 times higher half-life than at low ionic strength) were obtained with lipase immobilized in high ionic strength. Thermal stability of immobilized lipase was further improved by blocking unreacted epoxy groups on supports surface with amino acids. The most efficient was treatment with phenylalanine, since in such a way blocked immobilized enzyme retained 65% of initial activity after 8 h incubation at 65 degrees C, while non-blocked derivative retained 12%.",
publisher = "Elsevier Sci Ltd, Oxford",
journal = "Process Biochemistry",
title = "Immobilization of lipase on epoxy-activated Purolite((R)) A109 and its post-immobilization stabilization",
pages = "646-637",
number = "4",
volume = "49",
doi = "10.1016/j.procbio.2014.01.013"
}

Mihailović, M., Stojanović, M., Banjanac, K., Carević, M., Prlainović, N., Milosavić, N.,& Bezbradica, D.. (2014). Immobilization of lipase on epoxy-activated Purolite((R)) A109 and its post-immobilization stabilization. in Process Biochemistry
Elsevier Sci Ltd, Oxford., 49(4), 637-646.
https://doi.org/10.1016/j.procbio.2014.01.013

Mihailović M, Stojanović M, Banjanac K, Carević M, Prlainović N, Milosavić N, Bezbradica D. Immobilization of lipase on epoxy-activated Purolite((R)) A109 and its post-immobilization stabilization. in Process Biochemistry. 2014;49(4):637-646.
doi:10.1016/j.procbio.2014.01.013 .

Mihailović, Mladen, Stojanović, Marija, Banjanac, Katarina, Carević, Milica, Prlainović, Nevena, Milosavić, Nenad, Bezbradica, Dejan, "Immobilization of lipase on epoxy-activated Purolite((R)) A109 and its post-immobilization stabilization" in Process Biochemistry, 49, no. 4 (2014):637-646,
https://doi.org/10.1016/j.procbio.2014.01.013 . .

TY  - CONF
AU  - Prlainović, Nevena
AU  - Stojanović, Marija
AU  - Carević, Milica
AU  - Mihailović, Mladen
AU  - Banjanac, Katarina
AU  - Marinković, Aleksandar
AU  - Bezbradica, Dejan
PY  - 2013
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6072
AB  - Lipases are enzymes very well known for their laboratory and industrial application.
Various immobilization supports and techniques were examined in order to improve lipase
stability and activity for industrial application. Lipase can be immobilized by adsorption,
entrapment or by covalent binding [1]. Different supports are considered for enzyme
immobilization, organic or inorganic, natural or synthetic, but there is no unique solution.
Ideal support should posses enough active groups to interact with enzyme, but to be inert
to reaction media; it should be mechanically stable, renewable for many cycles and
inexpensive. Lately, nanoparticles of silica are used for enzyme immobilization because of
its extremely high surface area and controllable pore size. Nanoparticles of silica are
characterized by surface to volume ratio that is significantly higher than commonly used
supports. Some of the authors have also presented that nanoparticles of silica have
stabilization effect for the immobilized enzyme molecules[2]. Also in some cases
immobilization on nanoparticles also provides temperature stability of immobilized
enzyme[3].
In this study, nanoparticles of silica were modified in two-step process. The goal was to
introduce new reactive groups on silica surface, and make silica surface more suitable for
immobilization of lipase. In first step, nanoparticles of silica were treated with (3-
aminopropyl)-trimethoxysilane (APTMS), and then in step two, silica particles were treated
with cyanuric chloride (CTC) (temperature and molar ratio silica/CTC were variated). This
way nanoparticle of silica became rich in chloride groups, which enabled covalent
immobilization of lipase. FTIR analysis was performed after each modification step, and
confirmed presence of new active groups. Better results were obtained when second step
of modification was performed at 0 °C and high molar ratio silica/CTC. Lipase from
Candida rugosa was immobilized on modified nanoparticles of silica. Amount of proteins
bound was in range between 55 and 78%, but activity retention after immobilization
process was approximately 30%. Immobilized enzyme was used in reaction of aroma ester
synthesis, and reached conversion rate of 30% within 8 h.
C3  - 8th International Conference of the Chemical Societies of the South-East European Countries, Belgrade, Serbia
T1  - Two-step modification of silica nanoparticles for covalent lipase immobilization
SP  - 178
UR  - https://hdl.handle.net/21.15107/rcub_technorep_6072
ER  - 

@conference{
author = "Prlainović, Nevena and Stojanović, Marija and Carević, Milica and Mihailović, Mladen and Banjanac, Katarina and Marinković, Aleksandar and Bezbradica, Dejan",
year = "2013",
abstract = "Lipases are enzymes very well known for their laboratory and industrial application.
Various immobilization supports and techniques were examined in order to improve lipase
stability and activity for industrial application. Lipase can be immobilized by adsorption,
entrapment or by covalent binding [1]. Different supports are considered for enzyme
immobilization, organic or inorganic, natural or synthetic, but there is no unique solution.
Ideal support should posses enough active groups to interact with enzyme, but to be inert
to reaction media; it should be mechanically stable, renewable for many cycles and
inexpensive. Lately, nanoparticles of silica are used for enzyme immobilization because of
its extremely high surface area and controllable pore size. Nanoparticles of silica are
characterized by surface to volume ratio that is significantly higher than commonly used
supports. Some of the authors have also presented that nanoparticles of silica have
stabilization effect for the immobilized enzyme molecules[2]. Also in some cases
immobilization on nanoparticles also provides temperature stability of immobilized
enzyme[3].
In this study, nanoparticles of silica were modified in two-step process. The goal was to
introduce new reactive groups on silica surface, and make silica surface more suitable for
immobilization of lipase. In first step, nanoparticles of silica were treated with (3-
aminopropyl)-trimethoxysilane (APTMS), and then in step two, silica particles were treated
with cyanuric chloride (CTC) (temperature and molar ratio silica/CTC were variated). This
way nanoparticle of silica became rich in chloride groups, which enabled covalent
immobilization of lipase. FTIR analysis was performed after each modification step, and
confirmed presence of new active groups. Better results were obtained when second step
of modification was performed at 0 °C and high molar ratio silica/CTC. Lipase from
Candida rugosa was immobilized on modified nanoparticles of silica. Amount of proteins
bound was in range between 55 and 78%, but activity retention after immobilization
process was approximately 30%. Immobilized enzyme was used in reaction of aroma ester
synthesis, and reached conversion rate of 30% within 8 h.",
journal = "8th International Conference of the Chemical Societies of the South-East European Countries, Belgrade, Serbia",
title = "Two-step modification of silica nanoparticles for covalent lipase immobilization",
pages = "178",
url = "https://hdl.handle.net/21.15107/rcub_technorep_6072"
}

Prlainović, N., Stojanović, M., Carević, M., Mihailović, M., Banjanac, K., Marinković, A.,& Bezbradica, D.. (2013). Two-step modification of silica nanoparticles for covalent lipase immobilization. in 8th International Conference of the Chemical Societies of the South-East European Countries, Belgrade, Serbia, 178.
https://hdl.handle.net/21.15107/rcub_technorep_6072

Prlainović N, Stojanović M, Carević M, Mihailović M, Banjanac K, Marinković A, Bezbradica D. Two-step modification of silica nanoparticles for covalent lipase immobilization. in 8th International Conference of the Chemical Societies of the South-East European Countries, Belgrade, Serbia. 2013;:178.
https://hdl.handle.net/21.15107/rcub_technorep_6072 .

Prlainović, Nevena, Stojanović, Marija, Carević, Milica, Mihailović, Mladen, Banjanac, Katarina, Marinković, Aleksandar, Bezbradica, Dejan, "Two-step modification of silica nanoparticles for covalent lipase immobilization" in 8th International Conference of the Chemical Societies of the South-East European Countries, Belgrade, Serbia (2013):178,
https://hdl.handle.net/21.15107/rcub_technorep_6072 .

TY  - CONF
AU  - Carević, Milica
AU  - Vukašinović-Sekulić, Maja
AU  - Stojanović, Marija
AU  - Mihailović, Mladen
AU  - Jakovetić, Sonja
AU  - Grbavčić, Sanja
AU  - Bezbradica, Dejan
PY  - 2013
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6071
AB  - The α-galactosidase is important industrial enzyme, used both in food and feed industry,
that hydrolyses variety of non-digestible oligosaccharides with α-1,6-galactosydic bonds,
thus allowing wider consumption of soybean-derived products [1,2]. The aim of this work
was to produce this enzyme by submerged fermentation with Aspergillus oryzae DSM
1862 using several agricultural by-products (soybean meal, soybean flour, wheat bran,
barley bran) as substrates. Soybean flour was proved to be the substrate of choice, being
the most productive (3.34 IU/ml), and at the same time easiest for handling. In order to
optimize cultural conditions for obtaining highly active preparations, different parameters
were varied: substrate concentration (2-50 %), fermentation time (1-7 days), size of
inoculum (0.5-5%). The highest activity was achieved after 6 days submerged
fermentation using 2 % soybean flour and with 0.5 % of inoculum, since it showed no
influence on produced activity. Furthermore, purification was performed by simple
acetone precipitation and this was later proved by electrophoresis. The purified
preparation was characterized, and it was concluded that optimal conditions for raffinose
hydrolisis were 50 ᵒC and pH 4.8.
C3  - 8th International Conference of the Chemical Societies of the South-East European Countries, Belgrade, Serbia
T1  - Production and characterization of extracellular α-galactosidase from Aspergillus oryzae DSM 1862
SP  - 247
UR  - https://hdl.handle.net/21.15107/rcub_technorep_6071
ER  - 

@conference{
author = "Carević, Milica and Vukašinović-Sekulić, Maja and Stojanović, Marija and Mihailović, Mladen and Jakovetić, Sonja and Grbavčić, Sanja and Bezbradica, Dejan",
year = "2013",
abstract = "The α-galactosidase is important industrial enzyme, used both in food and feed industry,
that hydrolyses variety of non-digestible oligosaccharides with α-1,6-galactosydic bonds,
thus allowing wider consumption of soybean-derived products [1,2]. The aim of this work
was to produce this enzyme by submerged fermentation with Aspergillus oryzae DSM
1862 using several agricultural by-products (soybean meal, soybean flour, wheat bran,
barley bran) as substrates. Soybean flour was proved to be the substrate of choice, being
the most productive (3.34 IU/ml), and at the same time easiest for handling. In order to
optimize cultural conditions for obtaining highly active preparations, different parameters
were varied: substrate concentration (2-50 %), fermentation time (1-7 days), size of
inoculum (0.5-5%). The highest activity was achieved after 6 days submerged
fermentation using 2 % soybean flour and with 0.5 % of inoculum, since it showed no
influence on produced activity. Furthermore, purification was performed by simple
acetone precipitation and this was later proved by electrophoresis. The purified
preparation was characterized, and it was concluded that optimal conditions for raffinose
hydrolisis were 50 ᵒC and pH 4.8.",
journal = "8th International Conference of the Chemical Societies of the South-East European Countries, Belgrade, Serbia",
title = "Production and characterization of extracellular α-galactosidase from Aspergillus oryzae DSM 1862",
pages = "247",
url = "https://hdl.handle.net/21.15107/rcub_technorep_6071"
}

Carević, M., Vukašinović-Sekulić, M., Stojanović, M., Mihailović, M., Jakovetić, S., Grbavčić, S.,& Bezbradica, D.. (2013). Production and characterization of extracellular α-galactosidase from Aspergillus oryzae DSM 1862. in 8th International Conference of the Chemical Societies of the South-East European Countries, Belgrade, Serbia, 247.
https://hdl.handle.net/21.15107/rcub_technorep_6071

Carević M, Vukašinović-Sekulić M, Stojanović M, Mihailović M, Jakovetić S, Grbavčić S, Bezbradica D. Production and characterization of extracellular α-galactosidase from Aspergillus oryzae DSM 1862. in 8th International Conference of the Chemical Societies of the South-East European Countries, Belgrade, Serbia. 2013;:247.
https://hdl.handle.net/21.15107/rcub_technorep_6071 .

Carević, Milica, Vukašinović-Sekulić, Maja, Stojanović, Marija, Mihailović, Mladen, Jakovetić, Sonja, Grbavčić, Sanja, Bezbradica, Dejan, "Production and characterization of extracellular α-galactosidase from Aspergillus oryzae DSM 1862" in 8th International Conference of the Chemical Societies of the South-East European Countries, Belgrade, Serbia (2013):247,
https://hdl.handle.net/21.15107/rcub_technorep_6071 .

TY  - JOUR
AU  - Stojanović, Marija M.
AU  - Carević, Milica
AU  - Mihailović, Mladen
AU  - Knežević-Jugović, Zorica
AU  - Petrović, Slobodan
AU  - Bezbradica, Dejan
PY  - 2013
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2372
AB  - Fatty acid ascorbyl esters are liposoluble substances that possess good antioxidative properties. These compounds could be synthesized by using various acyl donors for acylation of vitamin C in reaction catalyzed by chemical means or lipases. The enzymatic process is preferred since it is regioselective, performed under mild reaction conditions, with the obtained product being environmentally friendly. Polar organic solvents, ionic liquids, and supercritical fluids have been successfully used as a reaction media, since commonly used solvents with high log P values are inapplicable due to ascorbic acid high polarity. Acylation of vitamin C using fatty acids, their methyl-, ethyl-, and vinyl esters, as well as triglycerides has been performed, whereas application of the activated acyl donors enabled higher molar conversions. In each case, the majority of authors reported that using excessive amount of the acyl donor had positive effect on yield of product. Furthermore, several strategies have been employed for shifting the equilibrium towards the product by water content control. These include adjusting the initial water activity by pre-equilibration of reaction mixture, enzyme preparation with water vapor of saturated salt solutions, and the removal of formed water by the addition of molecular sieves or salt hydrate pairs. The aim of this article is to provide a brief overview of the procedures described so far for the lipase-catalyzed synthesis of fatty acid ascorbyl esters with emphasis on the potential application in food, cosmetics, and pharmaceutics. Furthermore, it has been pointed out that the main obstacles for process commercialization are long reaction times, lack of adequate purification methods, and high costs of lipases. Thus, future challenges in this area are testing new catalysts, developing continuous processes for esters production, finding cheaper acyl donors and reaction mediums, as well as identifying standard procedures for purification of products which will not require consumption of large amounts of non-biocompatible organic solvents.
AB  - Askorbil-estri masnih kiselina su liposolubilna antioksidativna jedinjenja koja se pod blagim reakcionim uslovima mogu dobiti u reakcijama acilovanja vitamina C pomoću lipaza. Kao reakcione sredine do sada su bili uspešno korišćeni polarni organski rastvarači, jonske tečnosti i natkritični fluidi. Na ravnotežnu konverziju, pozitivan efekat pokazala je kontrola sadržaja vode kao i upotreba aktiviranih acil donora, a negativan efekat je poskupljenje i/ili smanjenje produktivnosti procesa. U ovom radu prikazan je kratak pregled do sada opisanih postupaka enzimske sinteze askorbil-estara masnih kiselina sa navođenjem njihove potencijalne primene kao aditiva u prehrambenoj, kozmetičkoj i farmaceutskoj industriji.
PB  - Association of Chemical Engineers of Serbia
T2  - Hemijska industrija
T1  - Enzymatic synthesis and application of fatty acid ascorbyl esters
T1  - Enzimska sinteza i primena askorbil-estara masnih kiselina
EP  - 247
IS  - 2
SP  - 239
VL  - 67
DO  - 10.2298/HEMIND120522079S
ER  - 

@article{
author = "Stojanović, Marija M. and Carević, Milica and Mihailović, Mladen and Knežević-Jugović, Zorica and Petrović, Slobodan and Bezbradica, Dejan",
year = "2013",
abstract = "Fatty acid ascorbyl esters are liposoluble substances that possess good antioxidative properties. These compounds could be synthesized by using various acyl donors for acylation of vitamin C in reaction catalyzed by chemical means or lipases. The enzymatic process is preferred since it is regioselective, performed under mild reaction conditions, with the obtained product being environmentally friendly. Polar organic solvents, ionic liquids, and supercritical fluids have been successfully used as a reaction media, since commonly used solvents with high log P values are inapplicable due to ascorbic acid high polarity. Acylation of vitamin C using fatty acids, their methyl-, ethyl-, and vinyl esters, as well as triglycerides has been performed, whereas application of the activated acyl donors enabled higher molar conversions. In each case, the majority of authors reported that using excessive amount of the acyl donor had positive effect on yield of product. Furthermore, several strategies have been employed for shifting the equilibrium towards the product by water content control. These include adjusting the initial water activity by pre-equilibration of reaction mixture, enzyme preparation with water vapor of saturated salt solutions, and the removal of formed water by the addition of molecular sieves or salt hydrate pairs. The aim of this article is to provide a brief overview of the procedures described so far for the lipase-catalyzed synthesis of fatty acid ascorbyl esters with emphasis on the potential application in food, cosmetics, and pharmaceutics. Furthermore, it has been pointed out that the main obstacles for process commercialization are long reaction times, lack of adequate purification methods, and high costs of lipases. Thus, future challenges in this area are testing new catalysts, developing continuous processes for esters production, finding cheaper acyl donors and reaction mediums, as well as identifying standard procedures for purification of products which will not require consumption of large amounts of non-biocompatible organic solvents., Askorbil-estri masnih kiselina su liposolubilna antioksidativna jedinjenja koja se pod blagim reakcionim uslovima mogu dobiti u reakcijama acilovanja vitamina C pomoću lipaza. Kao reakcione sredine do sada su bili uspešno korišćeni polarni organski rastvarači, jonske tečnosti i natkritični fluidi. Na ravnotežnu konverziju, pozitivan efekat pokazala je kontrola sadržaja vode kao i upotreba aktiviranih acil donora, a negativan efekat je poskupljenje i/ili smanjenje produktivnosti procesa. U ovom radu prikazan je kratak pregled do sada opisanih postupaka enzimske sinteze askorbil-estara masnih kiselina sa navođenjem njihove potencijalne primene kao aditiva u prehrambenoj, kozmetičkoj i farmaceutskoj industriji.",
publisher = "Association of Chemical Engineers of Serbia",
journal = "Hemijska industrija",
title = "Enzymatic synthesis and application of fatty acid ascorbyl esters, Enzimska sinteza i primena askorbil-estara masnih kiselina",
pages = "247-239",
number = "2",
volume = "67",
doi = "10.2298/HEMIND120522079S"
}

Stojanović, M. M., Carević, M., Mihailović, M., Knežević-Jugović, Z., Petrović, S.,& Bezbradica, D.. (2013). Enzymatic synthesis and application of fatty acid ascorbyl esters. in Hemijska industrija
Association of Chemical Engineers of Serbia., 67(2), 239-247.
https://doi.org/10.2298/HEMIND120522079S

Stojanović MM, Carević M, Mihailović M, Knežević-Jugović Z, Petrović S, Bezbradica D. Enzymatic synthesis and application of fatty acid ascorbyl esters. in Hemijska industrija. 2013;67(2):239-247.
doi:10.2298/HEMIND120522079S .

Stojanović, Marija M., Carević, Milica, Mihailović, Mladen, Knežević-Jugović, Zorica, Petrović, Slobodan, Bezbradica, Dejan, "Enzymatic synthesis and application of fatty acid ascorbyl esters" in Hemijska industrija, 67, no. 2 (2013):239-247,
https://doi.org/10.2298/HEMIND120522079S . .

TY  - JOUR
AU  - Bezbradica, Dejan
AU  - Stojanović, Marija
AU  - Veličković, Dušan
AU  - Dimitrijević, Aleksandra
AU  - Carević, Milica
AU  - Mihailović, Mladen
AU  - Milosavić, Nenad
PY  - 2013
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2550
AB  - The kinetics of L-ascorbyl oleate synthesis catalyzed by immobilized lipase from Candida antarctica in acetone was investigated. Significant inhibition of synthesis with an excess of ascorbic acid was observed. Experimental data were successfully fitted with a ping-pong bi-bi kinetic model with substrate inhibition, and related kinetic constants were determined. The kinetic study was performed at optimum experimental factors (temperature, initial water content, and enzyme concentration), which were determined using response surface methodology. Then, a model for predicting product-time progress curves was developed by expanding the obtained ping-pang model with terms describing ester hydrolysis. Kinetic constants of the reverse reaction were determined, and good congruence between the model and experimental data was achieved. Calculated kinetic constants revealed that lipase has the highest affinity for ascorbyl oleate, slightly lower activity with ascorbic acid, and the lowest activity with oleic acid. The obtained results are valuable for elucidating the reaction mechanism and represent an important contribution for reaction optimization and creating strategies to increase the productivity of vitamin C ester synthesis.
PB  - Elsevier Science Sa, Lausanne
T2  - Biochemical Engineering Journal
T1  - Kinetic model of lipase-catalyzed conversion of ascorbic acid and oleic acid to liposoluble vitamin C ester
EP  - 96
SP  - 89
VL  - 71
DO  - 10.1016/j.bej.2012.12.001
ER  - 

@article{
author = "Bezbradica, Dejan and Stojanović, Marija and Veličković, Dušan and Dimitrijević, Aleksandra and Carević, Milica and Mihailović, Mladen and Milosavić, Nenad",
year = "2013",
abstract = "The kinetics of L-ascorbyl oleate synthesis catalyzed by immobilized lipase from Candida antarctica in acetone was investigated. Significant inhibition of synthesis with an excess of ascorbic acid was observed. Experimental data were successfully fitted with a ping-pong bi-bi kinetic model with substrate inhibition, and related kinetic constants were determined. The kinetic study was performed at optimum experimental factors (temperature, initial water content, and enzyme concentration), which were determined using response surface methodology. Then, a model for predicting product-time progress curves was developed by expanding the obtained ping-pang model with terms describing ester hydrolysis. Kinetic constants of the reverse reaction were determined, and good congruence between the model and experimental data was achieved. Calculated kinetic constants revealed that lipase has the highest affinity for ascorbyl oleate, slightly lower activity with ascorbic acid, and the lowest activity with oleic acid. The obtained results are valuable for elucidating the reaction mechanism and represent an important contribution for reaction optimization and creating strategies to increase the productivity of vitamin C ester synthesis.",
publisher = "Elsevier Science Sa, Lausanne",
journal = "Biochemical Engineering Journal",
title = "Kinetic model of lipase-catalyzed conversion of ascorbic acid and oleic acid to liposoluble vitamin C ester",
pages = "96-89",
volume = "71",
doi = "10.1016/j.bej.2012.12.001"
}

Bezbradica, D., Stojanović, M., Veličković, D., Dimitrijević, A., Carević, M., Mihailović, M.,& Milosavić, N.. (2013). Kinetic model of lipase-catalyzed conversion of ascorbic acid and oleic acid to liposoluble vitamin C ester. in Biochemical Engineering Journal
Elsevier Science Sa, Lausanne., 71, 89-96.
https://doi.org/10.1016/j.bej.2012.12.001

Bezbradica D, Stojanović M, Veličković D, Dimitrijević A, Carević M, Mihailović M, Milosavić N. Kinetic model of lipase-catalyzed conversion of ascorbic acid and oleic acid to liposoluble vitamin C ester. in Biochemical Engineering Journal. 2013;71:89-96.
doi:10.1016/j.bej.2012.12.001 .

Bezbradica, Dejan, Stojanović, Marija, Veličković, Dušan, Dimitrijević, Aleksandra, Carević, Milica, Mihailović, Mladen, Milosavić, Nenad, "Kinetic model of lipase-catalyzed conversion of ascorbic acid and oleic acid to liposoluble vitamin C ester" in Biochemical Engineering Journal, 71 (2013):89-96,
https://doi.org/10.1016/j.bej.2012.12.001 . .

TY  - CONF
AU  - Milisavljević, Ana
AU  - Stojanović, Marija
AU  - Dinić, Ivana
AU  - Carević, Milica
AU  - Mihailović, Mladen
AU  - Milosavić, Nenad
AU  - Bezbradica, Dejan
PY  - 2013
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6070
AB  - Phloridzin is member of chemical class of dihydrochalcones, phenylpropanoids with
structure similar to chalcones, immediate flavonoid precursors, hence it is often classified
as flavonoid glucoside [1,2]. It is usually extracted from Malus species since it is very
abundant in young apple leaves and twigs. Due to its phenolic structure, phloridzin has
significant antioxidant activity and anti-UV properties, which makes it interesting for
application in food and cosmetics. Major limitation to wider application of phloridzin is its
low solubility in hydrophobic environment, which can be circumvented by synthesis of
physiologically active compounds derivatives by acylation of phloridzin. Synthesis of acyl
esters can be catalyzed by inorganic catalysts or enzymes, but chemical esterification is
not regioselective and results with unwanted functionalization of phenolic hydroxyl
groups responsible for antioxidative properties.
Therefore, in our study enzymatic esterification of phloridzin was performed using
immobilized lipase from Candida antarctica (Novozyme® 435). Several organic solvents
were tested and acetonitrile was proved to be the most adequate medium for this
reaction. Different acyl-donors were used with respect to chain length and saturation
level. Potential physiological activity of obtained esters was evaluated by determination of
their antioxidant activity using DPPH assay, so acyl donors were compared with respect to
both, product yields and antioxidant activity. After comparison of results of preliminary
study, phloridzyl oleate was selected as derivative with the best prospects and it used in
further experimental series for optimization of key experimental factors. Response surface
methodology was applied as statistical tool for optimization of product concentration (in
mM) as output and analyzed factors were: reaction time, temperature, enzyme
concentration, substrate molar ratio, and phloridzin concentration. After statistical
analysis each of examined experimental factors was found significant and second order
regression model was obtained. It was established that highest product concentration can
be expected at 68 oC, with 0.17 M of phloridzin, 2,5 % (w/v) of enzyme, 19-fold molar
excess of oleic acid after 7 days of reaction.
C3  - 8th International Conference of the Chemical Societies of the South-East European Countries, Belgrade, Serbia
T1  - Lipase-catalyzed synthesis of phloridzin esters
SP  - 254
UR  - https://hdl.handle.net/21.15107/rcub_technorep_6070
ER  - 

@conference{
author = "Milisavljević, Ana and Stojanović, Marija and Dinić, Ivana and Carević, Milica and Mihailović, Mladen and Milosavić, Nenad and Bezbradica, Dejan",
year = "2013",
abstract = "Phloridzin is member of chemical class of dihydrochalcones, phenylpropanoids with
structure similar to chalcones, immediate flavonoid precursors, hence it is often classified
as flavonoid glucoside [1,2]. It is usually extracted from Malus species since it is very
abundant in young apple leaves and twigs. Due to its phenolic structure, phloridzin has
significant antioxidant activity and anti-UV properties, which makes it interesting for
application in food and cosmetics. Major limitation to wider application of phloridzin is its
low solubility in hydrophobic environment, which can be circumvented by synthesis of
physiologically active compounds derivatives by acylation of phloridzin. Synthesis of acyl
esters can be catalyzed by inorganic catalysts or enzymes, but chemical esterification is
not regioselective and results with unwanted functionalization of phenolic hydroxyl
groups responsible for antioxidative properties.
Therefore, in our study enzymatic esterification of phloridzin was performed using
immobilized lipase from Candida antarctica (Novozyme® 435). Several organic solvents
were tested and acetonitrile was proved to be the most adequate medium for this
reaction. Different acyl-donors were used with respect to chain length and saturation
level. Potential physiological activity of obtained esters was evaluated by determination of
their antioxidant activity using DPPH assay, so acyl donors were compared with respect to
both, product yields and antioxidant activity. After comparison of results of preliminary
study, phloridzyl oleate was selected as derivative with the best prospects and it used in
further experimental series for optimization of key experimental factors. Response surface
methodology was applied as statistical tool for optimization of product concentration (in
mM) as output and analyzed factors were: reaction time, temperature, enzyme
concentration, substrate molar ratio, and phloridzin concentration. After statistical
analysis each of examined experimental factors was found significant and second order
regression model was obtained. It was established that highest product concentration can
be expected at 68 oC, with 0.17 M of phloridzin, 2,5 % (w/v) of enzyme, 19-fold molar
excess of oleic acid after 7 days of reaction.",
journal = "8th International Conference of the Chemical Societies of the South-East European Countries, Belgrade, Serbia",
title = "Lipase-catalyzed synthesis of phloridzin esters",
pages = "254",
url = "https://hdl.handle.net/21.15107/rcub_technorep_6070"
}

Milisavljević, A., Stojanović, M., Dinić, I., Carević, M., Mihailović, M., Milosavić, N.,& Bezbradica, D.. (2013). Lipase-catalyzed synthesis of phloridzin esters. in 8th International Conference of the Chemical Societies of the South-East European Countries, Belgrade, Serbia, 254.
https://hdl.handle.net/21.15107/rcub_technorep_6070

Milisavljević A, Stojanović M, Dinić I, Carević M, Mihailović M, Milosavić N, Bezbradica D. Lipase-catalyzed synthesis of phloridzin esters. in 8th International Conference of the Chemical Societies of the South-East European Countries, Belgrade, Serbia. 2013;:254.
https://hdl.handle.net/21.15107/rcub_technorep_6070 .

Milisavljević, Ana, Stojanović, Marija, Dinić, Ivana, Carević, Milica, Mihailović, Mladen, Milosavić, Nenad, Bezbradica, Dejan, "Lipase-catalyzed synthesis of phloridzin esters" in 8th International Conference of the Chemical Societies of the South-East European Countries, Belgrade, Serbia (2013):254,
https://hdl.handle.net/21.15107/rcub_technorep_6070 .

TY  - CONF
AU  - Mihailović, Mladen
AU  - Carević, Milica
AU  - Stojanović, Marija
AU  - Prlainović, Nevena
AU  - Banjanac, Katarina
AU  - Bezbradica, Dejan
PY  - 2013
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6073
AB  - Modern industry recognizes enzymes as important catalysts for batch production of food,
drugs and cosmetics. Because of their price and poor technical characteristics in free form,
enzymes are mostly used as immobilized derivative. Therefore, there is a constant need
for new and improved supports, possessing sufficient amount of active groups on it's
surface to interact with enzyme, but on the other side chemically inert to the reaction
media. Mechanical stability and price range are as much important as chemical stability.
The aim of this study was to investigate properties of modified ionic resin Purolite A109
for lipase immobilization. Purolite A109 is polystyrenic (styrene-divinylbenzene
copolymer), macro porous anion exchange resin with primary amine weak base functional
groups. It's advantages could be low price, and excellent mechanical and chemical
characteristics. Modification of this resin was performed using cyanuric chloride (CTC) and
epychlorhydrine. In both cases FTIR spectroscopy confirmed that modification process was
successful. Lipase from Candida rugosa was immobilized on both modified supports.
Approximately 30% of proteins was bound to both carrier. Hydrolytic activity of both, free
and immobilized lipase was determined, and based on these results activity retention
after immobilization process was calculated. Results showed that significantly higher
activity retention was obtained in case of CTC-Purolite – 67 %. Thermal stabilities of these
two immobilized enzymes on 65 °C were compared to thermal stability of free enzyme.
Relative activity of free enzyme decreased below 50% of initial activity within 30 min. On
the other hand, both immobilized enzymes showed significant thermal stability. Relative
activity of epoxy-Purolite dropped below 50 % of initial activity within 3 hours, while CTCPurolite
dropped below 50 % of initial activity within 5 hours.
C3  - 8th International Conference of the Chemical Societies of the South-East European Countries, Belgrade, Serbia
T1  - Chemical modification of Purolite A109 for application in lipase immobilization
SP  - 267
UR  - https://hdl.handle.net/21.15107/rcub_technorep_6073
ER  - 

@conference{
author = "Mihailović, Mladen and Carević, Milica and Stojanović, Marija and Prlainović, Nevena and Banjanac, Katarina and Bezbradica, Dejan",
year = "2013",
abstract = "Modern industry recognizes enzymes as important catalysts for batch production of food,
drugs and cosmetics. Because of their price and poor technical characteristics in free form,
enzymes are mostly used as immobilized derivative. Therefore, there is a constant need
for new and improved supports, possessing sufficient amount of active groups on it's
surface to interact with enzyme, but on the other side chemically inert to the reaction
media. Mechanical stability and price range are as much important as chemical stability.
The aim of this study was to investigate properties of modified ionic resin Purolite A109
for lipase immobilization. Purolite A109 is polystyrenic (styrene-divinylbenzene
copolymer), macro porous anion exchange resin with primary amine weak base functional
groups. It's advantages could be low price, and excellent mechanical and chemical
characteristics. Modification of this resin was performed using cyanuric chloride (CTC) and
epychlorhydrine. In both cases FTIR spectroscopy confirmed that modification process was
successful. Lipase from Candida rugosa was immobilized on both modified supports.
Approximately 30% of proteins was bound to both carrier. Hydrolytic activity of both, free
and immobilized lipase was determined, and based on these results activity retention
after immobilization process was calculated. Results showed that significantly higher
activity retention was obtained in case of CTC-Purolite – 67 %. Thermal stabilities of these
two immobilized enzymes on 65 °C were compared to thermal stability of free enzyme.
Relative activity of free enzyme decreased below 50% of initial activity within 30 min. On
the other hand, both immobilized enzymes showed significant thermal stability. Relative
activity of epoxy-Purolite dropped below 50 % of initial activity within 3 hours, while CTCPurolite
dropped below 50 % of initial activity within 5 hours.",
journal = "8th International Conference of the Chemical Societies of the South-East European Countries, Belgrade, Serbia",
title = "Chemical modification of Purolite A109 for application in lipase immobilization",
pages = "267",
url = "https://hdl.handle.net/21.15107/rcub_technorep_6073"
}

Mihailović, M., Carević, M., Stojanović, M., Prlainović, N., Banjanac, K.,& Bezbradica, D.. (2013). Chemical modification of Purolite A109 for application in lipase immobilization. in 8th International Conference of the Chemical Societies of the South-East European Countries, Belgrade, Serbia, 267.
https://hdl.handle.net/21.15107/rcub_technorep_6073

Mihailović M, Carević M, Stojanović M, Prlainović N, Banjanac K, Bezbradica D. Chemical modification of Purolite A109 for application in lipase immobilization. in 8th International Conference of the Chemical Societies of the South-East European Countries, Belgrade, Serbia. 2013;:267.
https://hdl.handle.net/21.15107/rcub_technorep_6073 .

Mihailović, Mladen, Carević, Milica, Stojanović, Marija, Prlainović, Nevena, Banjanac, Katarina, Bezbradica, Dejan, "Chemical modification of Purolite A109 for application in lipase immobilization" in 8th International Conference of the Chemical Societies of the South-East European Countries, Belgrade, Serbia (2013):267,
https://hdl.handle.net/21.15107/rcub_technorep_6073 .

TY  - CONF
AU  - Mihailović, Mladen D.
AU  - Banjanac, Katarina M.
AU  - Stojanović, Marija M.
AU  - Prlainović, Nevena Ž.
AU  - Jakovetić, Sonja M.
AU  - Carević, Milica B.
PY  - 2012
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6899
AB  - Lipaze su enzimi koji imaju široku primenu u prehrambenoj, kozmetičkoj i farmaceutskoj industriji. U
industrijskoj praksi primenjuju se imobilisane lipaze, s obzirom da se imobilizacijom povećava stabilnost samog
enzima, ali i ekonomičnost enzimskog postupaka proizvodnje. Kao nosači za imobilizaciju najčešće se koriste
sintetski ili prirodni polimeri bogati funkcionalnim grupama preko kojih se enzim može vezati. U nekim
slučajevima, neophodna je prethodna modifikacija nosača radi uvođenja funkcionalnih grupa. U ovom radu
lipaza je imobilisana na modifikovanu jonoizmenjivačku smolu, Purolite®
A109, koja je u osnovi kopolimer
stirena i divinilbenzena, a koja na površini poseduje primarnu amino grupu. Modifikacija nosača izvršena je sa
ciljem da se primarne amino grupe nosača prevedu u epoksi grupe, čime se dobija nosač pogodan za
kovalentnu imobilizaciju lipaze. Kovalentna imobilizacija je do sada pokazala najbolje rezultate kada su u
pitanju aktivnost i stabilnost dobijenih imobilizata1,2. Dobijeni imobilizati tretirani su aminokiselinama da bi se
ispitalo njihovo dejstvo na stabilnost i aktivnost imobilisane lipaze. Efekat tretmana aminokiselinama na
stabilnost imobilisane lipaze praćen je ispitivanjem aktivnosti netretiranog i tretiranih imobilizata tokom
inkubacije na 65 °C.
AB  - Lipases are important catalysts in pharmaceutical, cosmetics and food industry. On industrial scale, lipases are
used only in immobilized form. Majority of enzymes lose part of its initial activity during immobilization
process, but activity also decreases throughout storage and usage of immobilized lipase. Therefore, adequate
immobilization supports are prerequisite for successful application of immobilized enzyme. When it comes to
epoxy supports, after immobilization unreacted epoxy groups can interact with side chains of protein, which
could result in additional enzyme activity loss. Blocking of epoxy groups is usually performed with 2-
mercaptoethanol or ethylenediamine. In this study, treatment of immobilized lipase with different amino acids
(glycine, phenylalanine, arginine and aspartic acid) was performed. Phenylalanine and glycine exhibited
positive effect on stabilization of immobilized lipase, so this treatment should be examined more thoroughly.
On the other hand, arginine and aspartic acid showed no effect on stabilization of immobilized lipase.
PB  - Beograd : Srpsko hemijsko društvo
C3  - Program, kratki izvodi radova i zbornik radova / Prva konferencija mladih hemičara Srbije, Beograd, 19. i 20. oktobar 2012
T1  - Stabilizacija imobilisane lipaze iz Candida rugosa tretmanom imobilizata aminokiselinama
T1  - Stabilization of immobilized lipase from Candida rugosa by amino acid treatment
EP  - 85
SP  - 82
UR  - https://hdl.handle.net/21.15107/rcub_technorep_6899
ER  - 

@conference{
author = "Mihailović, Mladen D. and Banjanac, Katarina M. and Stojanović, Marija M. and Prlainović, Nevena Ž. and Jakovetić, Sonja M. and Carević, Milica B.",
year = "2012",
abstract = "Lipaze su enzimi koji imaju široku primenu u prehrambenoj, kozmetičkoj i farmaceutskoj industriji. U
industrijskoj praksi primenjuju se imobilisane lipaze, s obzirom da se imobilizacijom povećava stabilnost samog
enzima, ali i ekonomičnost enzimskog postupaka proizvodnje. Kao nosači za imobilizaciju najčešće se koriste
sintetski ili prirodni polimeri bogati funkcionalnim grupama preko kojih se enzim može vezati. U nekim
slučajevima, neophodna je prethodna modifikacija nosača radi uvođenja funkcionalnih grupa. U ovom radu
lipaza je imobilisana na modifikovanu jonoizmenjivačku smolu, Purolite®
A109, koja je u osnovi kopolimer
stirena i divinilbenzena, a koja na površini poseduje primarnu amino grupu. Modifikacija nosača izvršena je sa
ciljem da se primarne amino grupe nosača prevedu u epoksi grupe, čime se dobija nosač pogodan za
kovalentnu imobilizaciju lipaze. Kovalentna imobilizacija je do sada pokazala najbolje rezultate kada su u
pitanju aktivnost i stabilnost dobijenih imobilizata1,2. Dobijeni imobilizati tretirani su aminokiselinama da bi se
ispitalo njihovo dejstvo na stabilnost i aktivnost imobilisane lipaze. Efekat tretmana aminokiselinama na
stabilnost imobilisane lipaze praćen je ispitivanjem aktivnosti netretiranog i tretiranih imobilizata tokom
inkubacije na 65 °C., Lipases are important catalysts in pharmaceutical, cosmetics and food industry. On industrial scale, lipases are
used only in immobilized form. Majority of enzymes lose part of its initial activity during immobilization
process, but activity also decreases throughout storage and usage of immobilized lipase. Therefore, adequate
immobilization supports are prerequisite for successful application of immobilized enzyme. When it comes to
epoxy supports, after immobilization unreacted epoxy groups can interact with side chains of protein, which
could result in additional enzyme activity loss. Blocking of epoxy groups is usually performed with 2-
mercaptoethanol or ethylenediamine. In this study, treatment of immobilized lipase with different amino acids
(glycine, phenylalanine, arginine and aspartic acid) was performed. Phenylalanine and glycine exhibited
positive effect on stabilization of immobilized lipase, so this treatment should be examined more thoroughly.
On the other hand, arginine and aspartic acid showed no effect on stabilization of immobilized lipase.",
publisher = "Beograd : Srpsko hemijsko društvo",
journal = "Program, kratki izvodi radova i zbornik radova / Prva konferencija mladih hemičara Srbije, Beograd, 19. i 20. oktobar 2012",
title = "Stabilizacija imobilisane lipaze iz Candida rugosa tretmanom imobilizata aminokiselinama, Stabilization of immobilized lipase from Candida rugosa by amino acid treatment",
pages = "85-82",
url = "https://hdl.handle.net/21.15107/rcub_technorep_6899"
}

Mihailović, M. D., Banjanac, K. M., Stojanović, M. M., Prlainović, N. Ž., Jakovetić, S. M.,& Carević, M. B.. (2012). Stabilizacija imobilisane lipaze iz Candida rugosa tretmanom imobilizata aminokiselinama. in Program, kratki izvodi radova i zbornik radova / Prva konferencija mladih hemičara Srbije, Beograd, 19. i 20. oktobar 2012
Beograd : Srpsko hemijsko društvo., 82-85.
https://hdl.handle.net/21.15107/rcub_technorep_6899

Mihailović MD, Banjanac KM, Stojanović MM, Prlainović NŽ, Jakovetić SM, Carević MB. Stabilizacija imobilisane lipaze iz Candida rugosa tretmanom imobilizata aminokiselinama. in Program, kratki izvodi radova i zbornik radova / Prva konferencija mladih hemičara Srbije, Beograd, 19. i 20. oktobar 2012. 2012;:82-85.
https://hdl.handle.net/21.15107/rcub_technorep_6899 .

Mihailović, Mladen D., Banjanac, Katarina M., Stojanović, Marija M., Prlainović, Nevena Ž., Jakovetić, Sonja M., Carević, Milica B., "Stabilizacija imobilisane lipaze iz Candida rugosa tretmanom imobilizata aminokiselinama" in Program, kratki izvodi radova i zbornik radova / Prva konferencija mladih hemičara Srbije, Beograd, 19. i 20. oktobar 2012 (2012):82-85,
https://hdl.handle.net/21.15107/rcub_technorep_6899 .

TY  - JOUR
AU  - Mihailović, Mladen
AU  - Knežević-Jugović, Zorica
AU  - Mijin, Dušan
AU  - Bezbradica, Dejan
PY  - 2012
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2081
AB  - Lipases are very efficient biocatalysts with wide application in synthesis of important ingredients of food, cosmetics and pharmaceutical products, due to their capacity to catalyze both, ester synthesis and ester hydrolysis. The preparation of stable and active immobilized derivatives of lipases is necessity for their application in industrial enzymatic processes. In this work, the optimization of lipase from C. rugosa immobilization by microwave irradiation was performed, since it was previously reported that immobilization process can be drastically accelerated by means of microwave irradiation, even resulting with slight increase of lipase activity. Eupergit®, commercial support with active epoxy groups, was used as immobilization support. In first stage of our study, the immobilization time and ionic strength of immobilization buffer were optimized. It was found out that the highest immobilized activity can be achieved at high ionic strengths (1 M buffer) after 3 min, while further increase of immobilization time led to decrease of lipase activity. Then, the immobilized derivative obtained at optimum conditions was applied in synthesis of amyl isobutyrate in organic solvent. Key reaction factors (temperature, water concentration, immobilized lipase concentration, and substrate molar ratio) were optimized using response surface methodology. The substrate conversion higher above 85% was achieved in our study. The statistical analysis revealed that each of analyzed factors had significant effect on yield of ester, with initial enzyme concentration and substrate molar ratio being the most prominent factors. The second-order regression model that describes the effect of all four factors on substrate conversion was established. The optimum values of factors were: temperature 50°C, initial immobilized enzyme concentration 220 mg ml-1, added water concentration 0.1% (v/v), and molar ratio acid/alcohol 2.5.
AB  - Lipaze su enzimi koji imaju široku primenu u prehrambenoj, kozmetičkoj i farmaceutskoj industriji. U industrijskoj praksi primenjuju se imobilisane lipaze jer se imobilizacijom povećava njihova stabilnost i ekonomičnost enzimskih postupaka. U ovom radu optimizovana je imobilizacija lipaze iz C. rugosa na komercijalni nosač Eupergit® pomoću mikrotalasnog zračenja. Vreme izlaganja mikrotalasima i molaritet korišćenog pufera optimizovani su sa ciljem dobijanja imobilizata maksimalne aktivnosti. Radi optimizovanja reakcije sinteze amil-izobutirata, pomoću centralnog kompozitnog rotatabilnog plana ispitan je uticaj četiri reakciona faktora. Ustanovljeno je da su optimalni uslovi sinteze estra temperatura 50°C, početna koncentracija imobilisanog enzima 220 mg ml-1, koncentracija dodate vode 0,1% i molarni odnos supstrata 2,5.
PB  - Association of Chemical Engineers of Serbia
T2  - Hemijska industrija
T1  - Optimization of esterification activity of lipase from Candida rugosa immobilized using microwave irradiation
T1  - Optimizacija esterifikacione aktivnosti lipaze iz Candida rugosa imobilisane mikrotalasnim zračenjem
EP  - 19
IS  - 1
SP  - 9
VL  - 66
DO  - 10.2298/HEMIND110720060M
ER  - 

@article{
author = "Mihailović, Mladen and Knežević-Jugović, Zorica and Mijin, Dušan and Bezbradica, Dejan",
year = "2012",
abstract = "Lipases are very efficient biocatalysts with wide application in synthesis of important ingredients of food, cosmetics and pharmaceutical products, due to their capacity to catalyze both, ester synthesis and ester hydrolysis. The preparation of stable and active immobilized derivatives of lipases is necessity for their application in industrial enzymatic processes. In this work, the optimization of lipase from C. rugosa immobilization by microwave irradiation was performed, since it was previously reported that immobilization process can be drastically accelerated by means of microwave irradiation, even resulting with slight increase of lipase activity. Eupergit®, commercial support with active epoxy groups, was used as immobilization support. In first stage of our study, the immobilization time and ionic strength of immobilization buffer were optimized. It was found out that the highest immobilized activity can be achieved at high ionic strengths (1 M buffer) after 3 min, while further increase of immobilization time led to decrease of lipase activity. Then, the immobilized derivative obtained at optimum conditions was applied in synthesis of amyl isobutyrate in organic solvent. Key reaction factors (temperature, water concentration, immobilized lipase concentration, and substrate molar ratio) were optimized using response surface methodology. The substrate conversion higher above 85% was achieved in our study. The statistical analysis revealed that each of analyzed factors had significant effect on yield of ester, with initial enzyme concentration and substrate molar ratio being the most prominent factors. The second-order regression model that describes the effect of all four factors on substrate conversion was established. The optimum values of factors were: temperature 50°C, initial immobilized enzyme concentration 220 mg ml-1, added water concentration 0.1% (v/v), and molar ratio acid/alcohol 2.5., Lipaze su enzimi koji imaju široku primenu u prehrambenoj, kozmetičkoj i farmaceutskoj industriji. U industrijskoj praksi primenjuju se imobilisane lipaze jer se imobilizacijom povećava njihova stabilnost i ekonomičnost enzimskih postupaka. U ovom radu optimizovana je imobilizacija lipaze iz C. rugosa na komercijalni nosač Eupergit® pomoću mikrotalasnog zračenja. Vreme izlaganja mikrotalasima i molaritet korišćenog pufera optimizovani su sa ciljem dobijanja imobilizata maksimalne aktivnosti. Radi optimizovanja reakcije sinteze amil-izobutirata, pomoću centralnog kompozitnog rotatabilnog plana ispitan je uticaj četiri reakciona faktora. Ustanovljeno je da su optimalni uslovi sinteze estra temperatura 50°C, početna koncentracija imobilisanog enzima 220 mg ml-1, koncentracija dodate vode 0,1% i molarni odnos supstrata 2,5.",
publisher = "Association of Chemical Engineers of Serbia",
journal = "Hemijska industrija",
title = "Optimization of esterification activity of lipase from Candida rugosa immobilized using microwave irradiation, Optimizacija esterifikacione aktivnosti lipaze iz Candida rugosa imobilisane mikrotalasnim zračenjem",
pages = "19-9",
number = "1",
volume = "66",
doi = "10.2298/HEMIND110720060M"
}

Mihailović, M., Knežević-Jugović, Z., Mijin, D.,& Bezbradica, D.. (2012). Optimization of esterification activity of lipase from Candida rugosa immobilized using microwave irradiation. in Hemijska industrija
Association of Chemical Engineers of Serbia., 66(1), 9-19.
https://doi.org/10.2298/HEMIND110720060M

Mihailović M, Knežević-Jugović Z, Mijin D, Bezbradica D. Optimization of esterification activity of lipase from Candida rugosa immobilized using microwave irradiation. in Hemijska industrija. 2012;66(1):9-19.
doi:10.2298/HEMIND110720060M .

Mihailović, Mladen, Knežević-Jugović, Zorica, Mijin, Dušan, Bezbradica, Dejan, "Optimization of esterification activity of lipase from Candida rugosa immobilized using microwave irradiation" in Hemijska industrija, 66, no. 1 (2012):9-19,
https://doi.org/10.2298/HEMIND110720060M . .

TY  - JOUR
AU  - Bezbradica, Dejan
AU  - Mijin, Dušan
AU  - Mihailović, Mladen
AU  - Knežević-Jugović, Zorica
PY  - 2009
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/1455
AB  - BACKGROUND: Immobilization of lipase (triacylglycerol acylhydrolase EC 3.1.1.3) from Candida rugosa on Eupergite (R) C and Eupergit (R) C 250L was performed under microwave irradiation in order to reduce immobilization time. Lipase loading, hydrolytic activity, esterification activity and operational stability in organic solvent of immobilized lipase preparation were determined. RESULTS: The microwave-assisted procedure resulted in a 29% lower lipase loadings, compared with immobilized lipase obtained without microwaves. In hydrolytic activity assay, lipase immobilized under microwaves exhibited a 23% higher specific activity. Slight activation of lipase by microwave-assisted immobilization was observed, since specific activity was around 5% higher than for free lipase. Lipase of highest activity was obtained after 2 min immobilization on Eupergit (R) C. The same preparation exhibited high esterification activity in organic medium and a half life of 212 h was determined in multiple use assay. CONCLUSION: The application of microwave irradiation leads to reduction of immobilization time from 2 days to only 2 min. The immobilized lipase obtained has prospects for further application due to its high retained activity and stability.
PB  - Wiley, Hoboken
T2  - Journal of Chemical Technology and Biotechnology
T1  - Microwave-assisted immobilization of lipase from Candida rugosa on Eupergit (R) supports
EP  - 1648
IS  - 11
SP  - 1642
VL  - 84
DO  - 10.1002/jctb.2222
ER  - 

@article{
author = "Bezbradica, Dejan and Mijin, Dušan and Mihailović, Mladen and Knežević-Jugović, Zorica",
year = "2009",
abstract = "BACKGROUND: Immobilization of lipase (triacylglycerol acylhydrolase EC 3.1.1.3) from Candida rugosa on Eupergite (R) C and Eupergit (R) C 250L was performed under microwave irradiation in order to reduce immobilization time. Lipase loading, hydrolytic activity, esterification activity and operational stability in organic solvent of immobilized lipase preparation were determined. RESULTS: The microwave-assisted procedure resulted in a 29% lower lipase loadings, compared with immobilized lipase obtained without microwaves. In hydrolytic activity assay, lipase immobilized under microwaves exhibited a 23% higher specific activity. Slight activation of lipase by microwave-assisted immobilization was observed, since specific activity was around 5% higher than for free lipase. Lipase of highest activity was obtained after 2 min immobilization on Eupergit (R) C. The same preparation exhibited high esterification activity in organic medium and a half life of 212 h was determined in multiple use assay. CONCLUSION: The application of microwave irradiation leads to reduction of immobilization time from 2 days to only 2 min. The immobilized lipase obtained has prospects for further application due to its high retained activity and stability.",
publisher = "Wiley, Hoboken",
journal = "Journal of Chemical Technology and Biotechnology",
title = "Microwave-assisted immobilization of lipase from Candida rugosa on Eupergit (R) supports",
pages = "1648-1642",
number = "11",
volume = "84",
doi = "10.1002/jctb.2222"
}

Bezbradica, D., Mijin, D., Mihailović, M.,& Knežević-Jugović, Z.. (2009). Microwave-assisted immobilization of lipase from Candida rugosa on Eupergit (R) supports. in Journal of Chemical Technology and Biotechnology
Wiley, Hoboken., 84(11), 1642-1648.
https://doi.org/10.1002/jctb.2222

Bezbradica D, Mijin D, Mihailović M, Knežević-Jugović Z. Microwave-assisted immobilization of lipase from Candida rugosa on Eupergit (R) supports. in Journal of Chemical Technology and Biotechnology. 2009;84(11):1642-1648.
doi:10.1002/jctb.2222 .

Bezbradica, Dejan, Mijin, Dušan, Mihailović, Mladen, Knežević-Jugović, Zorica, "Microwave-assisted immobilization of lipase from Candida rugosa on Eupergit (R) supports" in Journal of Chemical Technology and Biotechnology, 84, no. 11 (2009):1642-1648,
https://doi.org/10.1002/jctb.2222 . .