TY  - CHAP
AU  - Milosavić, Nenad
AU  - Dimitrijević, Aleksandra
AU  - Veličković, Dušan
AU  - Bezbradica, Dejan
AU  - Knežević-Jugović, Zorica
AU  - Jankov, Ratko
PY  - 2012
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/1968
AB  - Enzymes are a particularly versatile class of catalysts that perform and regulate processes in living matter. Enzymatic regio-, chemo- and enantioselectivity were used in industry and in organic synthesis. The common perception is however, that enzymes are sensitive, unstable and have to be used in water, features that are not ideal for a catalyst and undesirable in most syntheses. In many cases a way to avoid at least part of these complaints is to immobilize enzymes. There are several immobilization techniques, and the best means of avoiding any negative influence on the structure of an enzyme is to encapsulate it. Due to its ability to form gel with multivalent cations under relatively mild conditions, alginates are very important in cell and enzyme encapsulation. Entrapment within insoluble alginate gel is recognized as a rapid, nontoxic, inexpensive and versatile method for immobilization of enzymes as well as cells. The resultant gel is biochemically inert and mechanically stable with interstitial spaces that are suitable for cell immobilization.
T2  - Alginates: Production, Types and Applications
T1  - Application of alginates in cell and enzyme immobilization
EP  - 60
SP  - 37
UR  - https://hdl.handle.net/21.15107/rcub_technorep_1968
ER  - 

@inbook{
author = "Milosavić, Nenad and Dimitrijević, Aleksandra and Veličković, Dušan and Bezbradica, Dejan and Knežević-Jugović, Zorica and Jankov, Ratko",
year = "2012",
abstract = "Enzymes are a particularly versatile class of catalysts that perform and regulate processes in living matter. Enzymatic regio-, chemo- and enantioselectivity were used in industry and in organic synthesis. The common perception is however, that enzymes are sensitive, unstable and have to be used in water, features that are not ideal for a catalyst and undesirable in most syntheses. In many cases a way to avoid at least part of these complaints is to immobilize enzymes. There are several immobilization techniques, and the best means of avoiding any negative influence on the structure of an enzyme is to encapsulate it. Due to its ability to form gel with multivalent cations under relatively mild conditions, alginates are very important in cell and enzyme encapsulation. Entrapment within insoluble alginate gel is recognized as a rapid, nontoxic, inexpensive and versatile method for immobilization of enzymes as well as cells. The resultant gel is biochemically inert and mechanically stable with interstitial spaces that are suitable for cell immobilization.",
journal = "Alginates: Production, Types and Applications",
booktitle = "Application of alginates in cell and enzyme immobilization",
pages = "60-37",
url = "https://hdl.handle.net/21.15107/rcub_technorep_1968"
}

Milosavić, N., Dimitrijević, A., Veličković, D., Bezbradica, D., Knežević-Jugović, Z.,& Jankov, R.. (2012). Application of alginates in cell and enzyme immobilization. in Alginates: Production, Types and Applications, 37-60.
https://hdl.handle.net/21.15107/rcub_technorep_1968

Milosavić N, Dimitrijević A, Veličković D, Bezbradica D, Knežević-Jugović Z, Jankov R. Application of alginates in cell and enzyme immobilization. in Alginates: Production, Types and Applications. 2012;:37-60.
https://hdl.handle.net/21.15107/rcub_technorep_1968 .

Milosavić, Nenad, Dimitrijević, Aleksandra, Veličković, Dušan, Bezbradica, Dejan, Knežević-Jugović, Zorica, Jankov, Ratko, "Application of alginates in cell and enzyme immobilization" in Alginates: Production, Types and Applications (2012):37-60,
https://hdl.handle.net/21.15107/rcub_technorep_1968 .

TY  - JOUR
AU  - Dimitrijević, Aleksandra
AU  - Veličković, Dušan
AU  - Bihelović, Filip
AU  - Bezbradica, Dejan
AU  - Jankov, Ratko
AU  - Milosavić, Nenad
PY  - 2012
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2201
AB  - Lipase A from Candida antarctica (CAL A) was purified to apparent homogeneity in a single step using hydroxyapatite (HAP) chromatography. CAL A bound to HAP was eluted with 10 mM Na-phosphate buffer, pH 7.0 containing 0.5% Triton X-100. The protocol resulted in a 3.74-fold purification with 94.7% final recovery and 400.83 U/mg specific activity. Silver staining after SDS-PAGE revealed the presence a single band of 45 kDa. The enzyme exhibited a temperature optimum of 60 degrees C, was unaffected by monovalent metal ions, but was destabilized by divalent metal ions (Zn2+, Ca2+, Mg2+, Cu2+, Mn2+) and stimulated by 50 mM Fe2+. Detergents at 0.1% concentrations did not affect lipase activity. Except for Triton X-100, detergent concentrations of 1% had a destabilizing effect.
PB  - Elsevier Sci Ltd, Oxford
T2  - Bioresource Technology
T1  - One-step, inexpensive high yield strategy for Candida antarctica lipase A isolation using hydroxyapatite
EP  - 362
SP  - 358
VL  - 107
DO  - 10.1016/j.biortech.2011.11.077
ER  - 

@article{
author = "Dimitrijević, Aleksandra and Veličković, Dušan and Bihelović, Filip and Bezbradica, Dejan and Jankov, Ratko and Milosavić, Nenad",
year = "2012",
abstract = "Lipase A from Candida antarctica (CAL A) was purified to apparent homogeneity in a single step using hydroxyapatite (HAP) chromatography. CAL A bound to HAP was eluted with 10 mM Na-phosphate buffer, pH 7.0 containing 0.5% Triton X-100. The protocol resulted in a 3.74-fold purification with 94.7% final recovery and 400.83 U/mg specific activity. Silver staining after SDS-PAGE revealed the presence a single band of 45 kDa. The enzyme exhibited a temperature optimum of 60 degrees C, was unaffected by monovalent metal ions, but was destabilized by divalent metal ions (Zn2+, Ca2+, Mg2+, Cu2+, Mn2+) and stimulated by 50 mM Fe2+. Detergents at 0.1% concentrations did not affect lipase activity. Except for Triton X-100, detergent concentrations of 1% had a destabilizing effect.",
publisher = "Elsevier Sci Ltd, Oxford",
journal = "Bioresource Technology",
title = "One-step, inexpensive high yield strategy for Candida antarctica lipase A isolation using hydroxyapatite",
pages = "362-358",
volume = "107",
doi = "10.1016/j.biortech.2011.11.077"
}

Dimitrijević, A., Veličković, D., Bihelović, F., Bezbradica, D., Jankov, R.,& Milosavić, N.. (2012). One-step, inexpensive high yield strategy for Candida antarctica lipase A isolation using hydroxyapatite. in Bioresource Technology
Elsevier Sci Ltd, Oxford., 107, 358-362.
https://doi.org/10.1016/j.biortech.2011.11.077

Dimitrijević A, Veličković D, Bihelović F, Bezbradica D, Jankov R, Milosavić N. One-step, inexpensive high yield strategy for Candida antarctica lipase A isolation using hydroxyapatite. in Bioresource Technology. 2012;107:358-362.
doi:10.1016/j.biortech.2011.11.077 .

Dimitrijević, Aleksandra, Veličković, Dušan, Bihelović, Filip, Bezbradica, Dejan, Jankov, Ratko, Milosavić, Nenad, "One-step, inexpensive high yield strategy for Candida antarctica lipase A isolation using hydroxyapatite" in Bioresource Technology, 107 (2012):358-362,
https://doi.org/10.1016/j.biortech.2011.11.077 . .

TY  - JOUR
AU  - Dimitrijević, Aleksandra
AU  - Veličković, Dušan
AU  - Bezbradica, Dejan
AU  - Bihelović, Filip
AU  - Jankov, Ratko
AU  - Milosavić, Nenad
PY  - 2011
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/1800
AB  - The production of lipase from Pseudozyma aphidis (DSM 70725) was determined in six different media. The highest lipase production was observed in a medium with glucose as the sole carbon source, and yeast extract and sodium nitrate as the nitrogen sources. The time course studies of growth and lipase production in the optimal medium revealed that the highest lipase production was achieved at the end of the log phase of growth, reaching the value of 35.0 U cm-3 in the fifth day of cultivation. The effects of various polar, water-miscible, organic solvents on the activity and stability of the crude lipase produced by P. aphidis were evaluated. The hydrolytic activity of the crude lipase towards p-nitrophenyl palmitate (p-NPP) in aqueous media and in organic solvents was determined, using the same spectrophotometric assay in both the aqueous and organic media. The crude lipase preparation exhibited activity towards p-NPP only in acetone and acetonitrile, while the lipase was stable only in acetone, with 23% residual activity after 24 h of incubation. These results suggested that lipase from P. aphidis can be used as a biocatalyst for potential applications in such organic solvents.
AB  - Proizvodnja lipaze iz Pseudozyma aphidis utvrđena je u šest različitih medijuma. Najviša proizvodnja uočena je u medijumu gde je glukoza bila izvor ugljenika, a ekstrakt kvasca i natrijum-nitrat izvori azota. Praćenjem dinamike rasta i proizvodnje lipaze u optimalnom medijumu, uočeno je da se najviša proizvodnja lipaze dostiže pred kraj logaritamske faze rasta, i dostiže vrednost od 35 U cm-3 u petom danu kultivacije, što je četri puta veća proizvodnja od one do sada prijavljene u literaturi. Utvrđen je efekat različitih polarnih organskih rastvarača, mešljivih sa vodom, na aktivnost i stabilnost lipaze iz P. aphidis. Hidrolitička aktivnost lipaze prema para-nitrofenil-palmitatu (p-NPP-u) u vo- denoj sredini i organskim rastvaračima utvrđena je upotrebom istog spektrofotometrijskog testa. Pokazano je da lipaza ima aktivnost prema p-NPP-u samo u acetonu i acetonitrilu, dok je enzim stabilan jedino u acetonu i zadržava 23% aktivnosti nakon 24 časa inkubacije. Dobijeni rezultati ukazuju da lipaza iz P. aphidis može biti korišćena kao biokatalizator za potencijalne primene u acetonu kao medijumu.
PB  - Serbian Chemical Society, Belgrade
T2  - Journal of the Serbian Chemical Society
T1  - Production of lipase from Pseudozyma aphidis and determination of the activity and stability of the crude lipase preparation in polar organic solvents
T1  - Proizvodnja lipaze iz Pseudozyma aphidis i utvrđivanje aktivnosti i stabilnosti lipaze u polarnim organskim rastvaračima
EP  - 1092
IS  - 8
SP  - 1081
VL  - 76
UR  - https://hdl.handle.net/21.15107/rcub_technorep_1800
ER  - 

@article{
author = "Dimitrijević, Aleksandra and Veličković, Dušan and Bezbradica, Dejan and Bihelović, Filip and Jankov, Ratko and Milosavić, Nenad",
year = "2011",
abstract = "The production of lipase from Pseudozyma aphidis (DSM 70725) was determined in six different media. The highest lipase production was observed in a medium with glucose as the sole carbon source, and yeast extract and sodium nitrate as the nitrogen sources. The time course studies of growth and lipase production in the optimal medium revealed that the highest lipase production was achieved at the end of the log phase of growth, reaching the value of 35.0 U cm-3 in the fifth day of cultivation. The effects of various polar, water-miscible, organic solvents on the activity and stability of the crude lipase produced by P. aphidis were evaluated. The hydrolytic activity of the crude lipase towards p-nitrophenyl palmitate (p-NPP) in aqueous media and in organic solvents was determined, using the same spectrophotometric assay in both the aqueous and organic media. The crude lipase preparation exhibited activity towards p-NPP only in acetone and acetonitrile, while the lipase was stable only in acetone, with 23% residual activity after 24 h of incubation. These results suggested that lipase from P. aphidis can be used as a biocatalyst for potential applications in such organic solvents., Proizvodnja lipaze iz Pseudozyma aphidis utvrđena je u šest različitih medijuma. Najviša proizvodnja uočena je u medijumu gde je glukoza bila izvor ugljenika, a ekstrakt kvasca i natrijum-nitrat izvori azota. Praćenjem dinamike rasta i proizvodnje lipaze u optimalnom medijumu, uočeno je da se najviša proizvodnja lipaze dostiže pred kraj logaritamske faze rasta, i dostiže vrednost od 35 U cm-3 u petom danu kultivacije, što je četri puta veća proizvodnja od one do sada prijavljene u literaturi. Utvrđen je efekat različitih polarnih organskih rastvarača, mešljivih sa vodom, na aktivnost i stabilnost lipaze iz P. aphidis. Hidrolitička aktivnost lipaze prema para-nitrofenil-palmitatu (p-NPP-u) u vo- denoj sredini i organskim rastvaračima utvrđena je upotrebom istog spektrofotometrijskog testa. Pokazano je da lipaza ima aktivnost prema p-NPP-u samo u acetonu i acetonitrilu, dok je enzim stabilan jedino u acetonu i zadržava 23% aktivnosti nakon 24 časa inkubacije. Dobijeni rezultati ukazuju da lipaza iz P. aphidis može biti korišćena kao biokatalizator za potencijalne primene u acetonu kao medijumu.",
publisher = "Serbian Chemical Society, Belgrade",
journal = "Journal of the Serbian Chemical Society",
title = "Production of lipase from Pseudozyma aphidis and determination of the activity and stability of the crude lipase preparation in polar organic solvents, Proizvodnja lipaze iz Pseudozyma aphidis i utvrđivanje aktivnosti i stabilnosti lipaze u polarnim organskim rastvaračima",
pages = "1092-1081",
number = "8",
volume = "76",
url = "https://hdl.handle.net/21.15107/rcub_technorep_1800"
}

Dimitrijević, A., Veličković, D., Bezbradica, D., Bihelović, F., Jankov, R.,& Milosavić, N.. (2011). Production of lipase from Pseudozyma aphidis and determination of the activity and stability of the crude lipase preparation in polar organic solvents. in Journal of the Serbian Chemical Society
Serbian Chemical Society, Belgrade., 76(8), 1081-1092.
https://hdl.handle.net/21.15107/rcub_technorep_1800

Dimitrijević A, Veličković D, Bezbradica D, Bihelović F, Jankov R, Milosavić N. Production of lipase from Pseudozyma aphidis and determination of the activity and stability of the crude lipase preparation in polar organic solvents. in Journal of the Serbian Chemical Society. 2011;76(8):1081-1092.
https://hdl.handle.net/21.15107/rcub_technorep_1800 .

Dimitrijević, Aleksandra, Veličković, Dušan, Bezbradica, Dejan, Bihelović, Filip, Jankov, Ratko, Milosavić, Nenad, "Production of lipase from Pseudozyma aphidis and determination of the activity and stability of the crude lipase preparation in polar organic solvents" in Journal of the Serbian Chemical Society, 76, no. 8 (2011):1081-1092,
https://hdl.handle.net/21.15107/rcub_technorep_1800 .

TY  - JOUR
AU  - Veličković, Dušan
AU  - Dimitrijević, Aleksandra
AU  - Bihelović, Filip
AU  - Bezbradica, Dejan
AU  - Jankov, Ratko
AU  - Milosavić, Nenad
PY  - 2011
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/1891
AB  - In this report, alpha-isosalicin, a potent anticoagulant and skin whitening agent, was synthesized by a highly efficient chemoselective and diastereoselective reaction, catalyzed by maltase from bakers' yeast (Saccharomyces cerevisiae). The highest yield of this one-step transglucosylation reaction was achieved with 50 mM of salicyl alcohol as a glucose acceptor. The key reaction factors were optimized using response surface methodology (RSM) with an enzyme concentration of 10 U/mL. The optimum temperature of the reaction was determined as 36.5 degrees C, the optimal maltose concentration was 40% (w/v), the optimal pH was 6.5, and the optimal reaction time was 16 h. Under these conditions 75% of alpha-isosalicin was obtained, with a yield of 10 g/L, and no by product formation was observed.
PB  - Elsevier Sci Ltd, Oxford
T2  - Process Biochemistry
T1  - A highly efficient diastereoselective synthesis of alpha-isosalicin by maltase from Saccharomyces cerevisiae
EP  - 1702
IS  - 8
SP  - 1698
VL  - 46
DO  - 10.1016/j.procbio.2011.05.007
ER  - 

@article{
author = "Veličković, Dušan and Dimitrijević, Aleksandra and Bihelović, Filip and Bezbradica, Dejan and Jankov, Ratko and Milosavić, Nenad",
year = "2011",
abstract = "In this report, alpha-isosalicin, a potent anticoagulant and skin whitening agent, was synthesized by a highly efficient chemoselective and diastereoselective reaction, catalyzed by maltase from bakers' yeast (Saccharomyces cerevisiae). The highest yield of this one-step transglucosylation reaction was achieved with 50 mM of salicyl alcohol as a glucose acceptor. The key reaction factors were optimized using response surface methodology (RSM) with an enzyme concentration of 10 U/mL. The optimum temperature of the reaction was determined as 36.5 degrees C, the optimal maltose concentration was 40% (w/v), the optimal pH was 6.5, and the optimal reaction time was 16 h. Under these conditions 75% of alpha-isosalicin was obtained, with a yield of 10 g/L, and no by product formation was observed.",
publisher = "Elsevier Sci Ltd, Oxford",
journal = "Process Biochemistry",
title = "A highly efficient diastereoselective synthesis of alpha-isosalicin by maltase from Saccharomyces cerevisiae",
pages = "1702-1698",
number = "8",
volume = "46",
doi = "10.1016/j.procbio.2011.05.007"
}

Veličković, D., Dimitrijević, A., Bihelović, F., Bezbradica, D., Jankov, R.,& Milosavić, N.. (2011). A highly efficient diastereoselective synthesis of alpha-isosalicin by maltase from Saccharomyces cerevisiae. in Process Biochemistry
Elsevier Sci Ltd, Oxford., 46(8), 1698-1702.
https://doi.org/10.1016/j.procbio.2011.05.007

Veličković D, Dimitrijević A, Bihelović F, Bezbradica D, Jankov R, Milosavić N. A highly efficient diastereoselective synthesis of alpha-isosalicin by maltase from Saccharomyces cerevisiae. in Process Biochemistry. 2011;46(8):1698-1702.
doi:10.1016/j.procbio.2011.05.007 .

Veličković, Dušan, Dimitrijević, Aleksandra, Bihelović, Filip, Bezbradica, Dejan, Jankov, Ratko, Milosavić, Nenad, "A highly efficient diastereoselective synthesis of alpha-isosalicin by maltase from Saccharomyces cerevisiae" in Process Biochemistry, 46, no. 8 (2011):1698-1702,
https://doi.org/10.1016/j.procbio.2011.05.007 . .

TY  - JOUR
AU  - Polović, Natalija
AU  - Pjanović, Rada
AU  - Burazer, Lidija M.
AU  - Veličković, Sava
AU  - Jankov, Ratko
AU  - Ćirković-Veličković, Tanja
PY  - 2009
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/1488
AB  - BACKGROUND: It is thought that food sensitisers must be able to reach the intestine in order to sensitise patients. Pectin is a gel-forming plant polysaccharide that can protect allergens from in vivo gastric digestion and in vitro pepsin digestion. The aim of this study was to examine if pectin gel formed in the acidic environment of the stomach can protect labile allergen from in vitro gastrointestinal digestion. RESULTS: Pectin forms a gel in the acidic conditions of gastric fluid up to a concentration of 1.0 +/- 0.14 g L(-1). Four allergenic fruits (kiwi, cherry, apple and banana) form gels in the same manner at the dilutions 14.8 +/- 0.4; 8.4 +/- 0.2, 9.4 +/- 0.35 and 29.1 +/- 0.2, respectively. The time necessary for dissolution of 50 g L(-1) pectin gel in intestinal fluid was found to be 70 +/- 0.2 min. Pectin gel formed in situ was able to protect Act c 1 from pepsin digestion for 1 h and from further intestinal digestion for one additional hour. CONCLUSION: Pectin gel in an acidic environment protects Act c 1 from pepsin digestion and dissolves slowly in the slightly basic environment of the intestine allowing the survival of fruit allergen for additional time and possible interaction with the gut immune system.
PB  - John Wiley & Sons Ltd, Chichester
T2  - Journal of the Science of Food and Agriculture
T1  - Acid-formed pectin gel delays major incomplete kiwi fruit allergen Act c 1 proteolysis in in vitro gastrointestinal digestion
EP  - 14
IS  - 1
SP  - 8
VL  - 89
DO  - 10.1002/jsfa.3404
ER  - 

@article{
author = "Polović, Natalija and Pjanović, Rada and Burazer, Lidija M. and Veličković, Sava and Jankov, Ratko and Ćirković-Veličković, Tanja",
year = "2009",
abstract = "BACKGROUND: It is thought that food sensitisers must be able to reach the intestine in order to sensitise patients. Pectin is a gel-forming plant polysaccharide that can protect allergens from in vivo gastric digestion and in vitro pepsin digestion. The aim of this study was to examine if pectin gel formed in the acidic environment of the stomach can protect labile allergen from in vitro gastrointestinal digestion. RESULTS: Pectin forms a gel in the acidic conditions of gastric fluid up to a concentration of 1.0 +/- 0.14 g L(-1). Four allergenic fruits (kiwi, cherry, apple and banana) form gels in the same manner at the dilutions 14.8 +/- 0.4; 8.4 +/- 0.2, 9.4 +/- 0.35 and 29.1 +/- 0.2, respectively. The time necessary for dissolution of 50 g L(-1) pectin gel in intestinal fluid was found to be 70 +/- 0.2 min. Pectin gel formed in situ was able to protect Act c 1 from pepsin digestion for 1 h and from further intestinal digestion for one additional hour. CONCLUSION: Pectin gel in an acidic environment protects Act c 1 from pepsin digestion and dissolves slowly in the slightly basic environment of the intestine allowing the survival of fruit allergen for additional time and possible interaction with the gut immune system.",
publisher = "John Wiley & Sons Ltd, Chichester",
journal = "Journal of the Science of Food and Agriculture",
title = "Acid-formed pectin gel delays major incomplete kiwi fruit allergen Act c 1 proteolysis in in vitro gastrointestinal digestion",
pages = "14-8",
number = "1",
volume = "89",
doi = "10.1002/jsfa.3404"
}

Polović, N., Pjanović, R., Burazer, L. M., Veličković, S., Jankov, R.,& Ćirković-Veličković, T.. (2009). Acid-formed pectin gel delays major incomplete kiwi fruit allergen Act c 1 proteolysis in in vitro gastrointestinal digestion. in Journal of the Science of Food and Agriculture
John Wiley & Sons Ltd, Chichester., 89(1), 8-14.
https://doi.org/10.1002/jsfa.3404

Polović N, Pjanović R, Burazer LM, Veličković S, Jankov R, Ćirković-Veličković T. Acid-formed pectin gel delays major incomplete kiwi fruit allergen Act c 1 proteolysis in in vitro gastrointestinal digestion. in Journal of the Science of Food and Agriculture. 2009;89(1):8-14.
doi:10.1002/jsfa.3404 .

Polović, Natalija, Pjanović, Rada, Burazer, Lidija M., Veličković, Sava, Jankov, Ratko, Ćirković-Veličković, Tanja, "Acid-formed pectin gel delays major incomplete kiwi fruit allergen Act c 1 proteolysis in in vitro gastrointestinal digestion" in Journal of the Science of Food and Agriculture, 89, no. 1 (2009):8-14,
https://doi.org/10.1002/jsfa.3404 . .

TY  - JOUR
AU  - Ahmed, Khaled S.O.H.
AU  - Milosavić, Nenad
AU  - Popović, Milica M.
AU  - Prodanović, Radivoje
AU  - Knežević, Zorica
AU  - Jankov, Ratko
PY  - 2007
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/1111
AB  - α-Glucosidase from S. cerevisiae was covalently immobilized onto Sepabeads EC-EA by the glutaraldehyde method. An analysis of the variables controlling the immobilization process is first presented and it is shown that the highest coupling of α-glucosidase occurred within 24 h. Also, a loading of 30 mg/g support proved to be effective, resulting in a rather high activity of around 45 U g-1 with a satisfactory degree of enzyme fixed. Both free and immobilized enzymes were then characterized by determining the activity profile as a function of pH, temperature and thermal stability. The obtained immobilized preparation showed the same optimum pH, but a higher optimum temperature compared with the soluble one. In addition, the immobilized enzyme treated at 45 ºC for 1 h still retained an activity of around 20 %, whereas the free enzyme completely lost its original activity under this condition. In conclusion, the developed immobilization procedure is quite simple, easily reproducible and provides a promising solution for the application of immobilized α-glucosidase.
AB  - Maltaza iz S. cerevisiae je kovalentno imobilizovana na Sepabeads EC-EA nakon aktivacije nosača rastvorom glutaraldehida. Ispitivanjem kinetike imobilizacije utvrđeno je da se 25 % enzima imobilizuje nakon 24 časa. Imobilizovana α-glukozidaza ima isti pH optimum kao i rastvorni enzim, dok je optimalna temperatura za aktivnost imobilizovanog enzima uvećana za 10 °C u poređenju sa rastvornim enzimom. Kada se uporede zaostale aktivnosti rastvorne i imobilizovane forme α-glukozidaze, nakon inkubacije od 1 h na 45 °C rastvorni enzim ne pokazuje aktivnost dok imobilizovana forma zadržava oko 20 % početne aktivnosti. Imobilizovana forma enzima zadržava 20 % početne aktivnosti čak i posle 3 h inkubacije na 45 °C.
PB  - Serbian Chemical Society, Belgrade
T2  - Journal of the Serbian Chemical Society
T1  - Preparation and studies on immobilized α-glucosidase from baker’s yeast Saccharomyces cerevisiae
T1  - Dobijanje i proučavanje imobilizacije α-glukozidaze iz pekarskog kvasca Saccharomyces cerevisiae
EP  - 1263
IS  - 12
SP  - 1255
VL  - 72
UR  - https://hdl.handle.net/21.15107/rcub_technorep_1111
ER  - 

@article{
author = "Ahmed, Khaled S.O.H. and Milosavić, Nenad and Popović, Milica M. and Prodanović, Radivoje and Knežević, Zorica and Jankov, Ratko",
year = "2007",
abstract = "α-Glucosidase from S. cerevisiae was covalently immobilized onto Sepabeads EC-EA by the glutaraldehyde method. An analysis of the variables controlling the immobilization process is first presented and it is shown that the highest coupling of α-glucosidase occurred within 24 h. Also, a loading of 30 mg/g support proved to be effective, resulting in a rather high activity of around 45 U g-1 with a satisfactory degree of enzyme fixed. Both free and immobilized enzymes were then characterized by determining the activity profile as a function of pH, temperature and thermal stability. The obtained immobilized preparation showed the same optimum pH, but a higher optimum temperature compared with the soluble one. In addition, the immobilized enzyme treated at 45 ºC for 1 h still retained an activity of around 20 %, whereas the free enzyme completely lost its original activity under this condition. In conclusion, the developed immobilization procedure is quite simple, easily reproducible and provides a promising solution for the application of immobilized α-glucosidase., Maltaza iz S. cerevisiae je kovalentno imobilizovana na Sepabeads EC-EA nakon aktivacije nosača rastvorom glutaraldehida. Ispitivanjem kinetike imobilizacije utvrđeno je da se 25 % enzima imobilizuje nakon 24 časa. Imobilizovana α-glukozidaza ima isti pH optimum kao i rastvorni enzim, dok je optimalna temperatura za aktivnost imobilizovanog enzima uvećana za 10 °C u poređenju sa rastvornim enzimom. Kada se uporede zaostale aktivnosti rastvorne i imobilizovane forme α-glukozidaze, nakon inkubacije od 1 h na 45 °C rastvorni enzim ne pokazuje aktivnost dok imobilizovana forma zadržava oko 20 % početne aktivnosti. Imobilizovana forma enzima zadržava 20 % početne aktivnosti čak i posle 3 h inkubacije na 45 °C.",
publisher = "Serbian Chemical Society, Belgrade",
journal = "Journal of the Serbian Chemical Society",
title = "Preparation and studies on immobilized α-glucosidase from baker’s yeast Saccharomyces cerevisiae, Dobijanje i proučavanje imobilizacije α-glukozidaze iz pekarskog kvasca Saccharomyces cerevisiae",
pages = "1263-1255",
number = "12",
volume = "72",
url = "https://hdl.handle.net/21.15107/rcub_technorep_1111"
}

Ahmed, K. S.O.H., Milosavić, N., Popović, M. M., Prodanović, R., Knežević, Z.,& Jankov, R.. (2007). Preparation and studies on immobilized α-glucosidase from baker’s yeast Saccharomyces cerevisiae. in Journal of the Serbian Chemical Society
Serbian Chemical Society, Belgrade., 72(12), 1255-1263.
https://hdl.handle.net/21.15107/rcub_technorep_1111

Ahmed KS, Milosavić N, Popović MM, Prodanović R, Knežević Z, Jankov R. Preparation and studies on immobilized α-glucosidase from baker’s yeast Saccharomyces cerevisiae. in Journal of the Serbian Chemical Society. 2007;72(12):1255-1263.
https://hdl.handle.net/21.15107/rcub_technorep_1111 .

Ahmed, Khaled S.O.H., Milosavić, Nenad, Popović, Milica M., Prodanović, Radivoje, Knežević, Zorica, Jankov, Ratko, "Preparation and studies on immobilized α-glucosidase from baker’s yeast Saccharomyces cerevisiae" in Journal of the Serbian Chemical Society, 72, no. 12 (2007):1255-1263,
https://hdl.handle.net/21.15107/rcub_technorep_1111 .