SVIBOR - Papers - project code: 4-07-032

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Published papers on project 4-07-032


Quoted papers: 3
Other papers: 19
Total: 22


  1. Type of paper: Paper in journal

    Title: DEVELOPMENT OF REACTOR MODEL FOR GLUCOSE ISOMERIZATION CATALYZED BY WHOLE-CELL IMMOBILIZED GLUCOSE ISOMERASE

    Authors:
    Vasić-Rački, Đurđa (51631)
    Pavlović, Nediljko
    Čižmek, Sonja
    Dražić, Mensura
    Husadžić, Bečir (11581)
    Journal: Bioprocess Engineering
    ISSN: 0178-515
    Volume: 7
    Year: 1991
    Pages: from 183 to 187
    Number of references: 12
    Language: engleski
    Summary: Based on the kinetic constants determined and the mathematicalmodel for reactor system developed, the performance of axial flowpacked bed continuous enzyme reactor system was studiedexperimentally and also simulated with the aid of a computer forultimate objective of optimization of the glucose isomerasereactor system. A reactor model was established analogous toheterogeneous catalytic reactor model taking into account theeffect of fluid mass transfer and reversible kinetics. Theinvestigated catalyst system consists of immobilized Streptomycesbambergiensis cells containing the enzyme glucose isomerase,which catalyzes the izomerization of glucose to fructose.
    Keywords: glucose isomerase, enzymatic isomerization of glucose, reactor model

  2. Type of paper: Paper in journal

    Title: MODELLING OF IMMOBILIZATION PROCESS OF ENZYMES ON POROUS SUPPORT

    Authors:
    Vasić-Rački, Đurđa (51631)
    Geržina, Anka
    Plavljanić, Čedomir
    Journal: Kemija u industriji
    Number: 3
    ISSN: 0022-9830
    Volume: 40
    Year: 1991
    Pages: from 97 to 103
    Number of references: 13
    Language: hrvatski
    Summary: The enzyme adsorption from finite bath onto porous sphericalsupport is investigated both experimentally and theoreticallyusing yeast alcohol dehydrogenase and Lewatit MP-500 ion-exchangereasin as a model system and it is demonstrated how enzymeadsorption can be modelled. On the basis od adsorption model amodel for the immobilization process, which describesquantitatively the process of immobilization of a single enzymeinto porous solid support, was developed. The experimentalresults have been analyzed for comparison with the theoreticalmodel predictions. Predictions based on the model are consistentwith experimental results, which show that most of the enzyme isconfined to the outer half of the support.
    Keywords: immobilization of yeast alcohol dehydrogenase, modelling of enzyme immobilization process

  3. Type of paper: Paper in journal

    Title: KONTINUIERLICHE REAKTIONSFUEHRUNG MIT LOESLICHEN ENZYMEN

    Authors:
    Kragl, Udo
    Vasić-Rački, Đurđa (51631)
    Wandrey, Christian
    Journal: Chemie Ingenieur Technik
    Number: 6
    ISSN: 0009-286
    Volume: 64
    Year: 1992
    Pages: from 499 to 509
    Number of references: 107
    Language: njemački
    Summary: Die Arbeit beschreibt im šberblick die Verwendung von Enzym-Ɛ‘’“”•–—˜™šm- Membran-Reaktoren mit erzwungener Konvektion, beidenen l”sliche Enzyme in einem kontinuierlich durchflossenenReaktionsgef„á mit Š‰ˆ‡ć…„ƒƒ„ Hilfe einerUltrafiltrationsmembran zurckgehalten werden. Die Technik ist amBeispiel der L-Aminos„ure-Herstellung nach dem Acylase-Verfahrenim 200 t/a-Maástab kommerzialisiert worden. Sie eignet sichbesonders fr Multienzymsysteme mit Cofaktorrregenerierung. Diesist am Beispiel der L-tert-Leucin- Herstellung aus derkorrespondierenden ŕ-Keto-s„ure im Kilogramm Maástab gelungen. Anwasserl”sliche Polymere gebundene Coenzyme k”nnen zusammen mitden Enzymen im Membranreaktor zurckgehalten werden. Durchgeeignete experimentelle Bedingungen kann der Verlust durchElution ber die Membran bzw. Desaktivierung fr dieEnzyme/Coenzyme in vielen F„llen so gering gehalten werden, daáer wirtschaftlich nicht mehr limitierend ist. So gelang es,Coenzyme bis zu 600000 mal bei kontinuierlicher Reaktionsfhrungim Membranreaktor zu regenerieren. Am Beispiel der enzymatischenPeptid-Synthese wurden Raum-Zeit-Ausbeuten von mehr als 25kg/(ld) erreicht. Zur Unterdrckung unerwnschterParallelreaktionen kann mit extrem hohen Katalysator-konzentrationen gearbeitet werden, so daá Verweilzeiten bis unter4 min m”glich sind.
    Keywords: enzyme membrane reactor, continuous processes with soluble enzymes, enzymatic syntehsis of L-tert leucine

  4. Type of paper: Paper in journal

    Title: THE CONTINUOUS PRODUCTION OF ACETIC ACID BY ELECTRODIALYSIS INTEGRATEDFERMENTATION. MODELLING AND COMPUTER SIMULATION

    Authors:
    Eysmondt von, Jorg
    Vasić-Rački, Đurđa (51631)
    Wandrey, Christian
    Journal: Chemical and Biochemical Engineering Quarterly
    Number: 3
    ISSN: 0352-9568
    Volume: 7
    Year: 1993
    Pages: from 139 to 148
    Number of references: 15
    Language: engleski
    Summary: The electrodialysis fermentation method was used to reduce theeffect of end product inhibition in acetic acid fermentation byAcetogenium kivui. A complete mathematical model for integratedfermentor and electrodialyzer was developed. The steady-stateequations representing the mass balances of integrated systemhave been solved and the results compared with those obtainedexperimentally. The model predicts a higher total acetic acidproductivity than for a conventional chemostat fermentor of 50g/l glucose feed if a glucose feed of 120 g/l is fermented.Furthermore, the model illustrates the possible dependenceexisting between accumulated biomass, conversion of glucose,acetic acid concentration in fermentor, space-time-yield andseparation efficiency in electrodialyzer.
    Keywords: Continuous electrodialysis acetic acid fermentation, modelling of integrated fermentation, modelling of acetic acid electrodialysis

  5. Type of paper: Paper in journal

    Title: CONTINUOUS PROCESSES WITH SOLUBLE ENZYMES

    Authors:
    Kragl, Udo
    Vasić-Rački, Đurđa (51631)
    Wandrey, Christian
    Journal: Indian Journal of Chemistry
    ISSN: 0376-4699
    Volume: 32
    Year: 1993
    Pages: from 103 to 117
    Number of references: 107
    Language: engleski
    Summary: This paper surveys the use of continuously operatingenzyme-membrane reactors with enforced flow where the retentionof soluble enzymes in the reaction vessel is achieved by means ofan ultrafiltration membrane. This technique has beencommercialized in the acylase process for the synthesis ofL-amino acids on a 200 ton/year level. It is especially usefulfor the application of multi-enzyme systems with cofactorregeneration. The synthesis of L-tert-leucine from correspondingŕ-keto acid has been achieved on a kilogram scale. Coenzymescoupled to water soluble polymers are retained in themembrane-reactor together with the enzymes. Use of suitableconditions prevents loss of enzyme and coenzyme by passagethrough the membrane or by deactivation. Therefore the costs ofenzymes and coenzymes are no longer limitations for economicprocesses. In the continuously operating enzyme-membrane reactorregeneration of the coenzyme up to 600000 times was achieved. Incontinuous peptide synthesis space-time yields 25 kg/(l*d) wereobtained. To suppress side reactions very high catalystconcentrations are possible, yielding residence times below 4min.

  6. Type of paper: Paper in proceedings

    Title: ULTRAFILTRATION AND BIOCATALYSTS

    Authors:
    Vasić-Rački, Đurđa (51631)
    Wandrey, Christian
    Proceedings title: SEPARACIJSKI PROCESI V HETEROGENIH SISTEMIH
    Language: hrvatski
    Place: Maribor, Slovenija
    Year: 1992
    Pages: from 82 to 93
    Meeting: Posvetovanje "Separacijski procesi v heterogenih sistemih"
    Held: from 10/13/92 to 10/14/92
    Summary: The main application of ultrafiltration in biotechnology is forthe concentration of extracellular enzymes from dilute solutions,with simultaneous removal of low molar mass compounds(e.g.salts). These ultrafiltration devices can also be used forreactions, allowing re-use of biocatalysts in catalyticprocesses. The main advantage of combining the use ofbiocatalysts and ultrafiltration membranes in enzyme membranereactors is that continuous operation and recovery of thereaction product is possible when using a homogeneous phasesystem.
    Keywords: ultrafiltration, enzyme membrane reactor

  7. Type of paper: Summary in proceedings

    Title: ENZYME REAKTOR WITH ULTRAFILTRATION MEMBRANE: MODELLING AND APPLICATION IN BIOTECHNOLOGY

    Authors:
    Vasić-Rački, Đurđa (51631)
    Proceedings title: III Jugoslovenski simpozijum o hemijskom inženjerstvu
    Language: hrvatski
    Place: Novi Sad, Vojvodina
    Year: 1991
    Pages: from 14 to 0
    Meeting: III Jugoslovenski simpozijum o hemijskom inženjerstvu
    Held: from 01/16/91 to 01/18/91

  8. Type of paper: Summary in proceedings

    Title: ENZYMATIC ISOMERIZATION OF GLUCOSE IN INTEGRATED BIOCONVERSION/BIOSEPARATION PROCESS

    Authors:
    Matijašević, Ljubica (82036)
    Plavljanić, Čedomir
    Vasić-Rački, Đurđa (51631)
    Proceedings title: III Jugoslovenski simpozijum o hemijskom inženjerstvu
    Language: hrvatski
    Place: Novi Sad, Vojvodina
    Year: 1991
    Pages: from 20 to 20
    Held: from 01/16/91 to 01/18/91

  9. Type of paper: Summary in proceedings

    Title: ENZYMATIC RESOLUTION OF RACEMIC COMPOUNDS: MODELLING OF KINETICS

    Authors:
    Vasić-Rački, Đurđa (51631)
    Wandrey, Christian
    Proceedings title: XII. Sastanak kemičara Hrvatske
    Language: hrvatski
    Place: Zagreb
    Year: 1991
    Pages: from 278 to 278
    Meeting: XII. Sastanak kemičara Hrvatske
    Held: from 02/11/91 to 02/13/91

  10. Type of paper: Summary in proceedings

    Title: INVESTIGATION OF ADSORPTION CHARACTERISTICS OF GLUCOSE AND FRUCTOSE USING THE MOMENT ANALYSIS TECHNIQUE

    Authors:
    Matijašević, Ljubica (82036)
    Vasić-Rački, Đurđa (51631)
    Proceedings title: XII. Sasatanak kemičara Hrvatske
    Language: hrvatski
    Place: Zagreb
    Year: 1991
    Pages: from 280 to 280
    Meeting: XII. Sastanak kemičara Hrvatske
    Held: from 02/11/91 to 02/13/91

  11. Type of paper: Summary in proceedings

    Title: MODELLING OF COUNTER-CURRENT ADSORPTION SYSTEM FOR SEPARATION OF GLUCOSE/FRUCTOSE MIXTURES

    Authors:
    Matijašević, Ljubica (82036)
    Plavljanić, Čedomir
    Vasić-Rački, Đurđa (51631)
    Proceedings title: XIII. Skup hrvatskih kemičara
    Language: hrvatski
    Place: Zagreb
    Year: 1993
    Pages: from 321 to 321
    Meeting: XIII. Skup hrvatskih kemičara
    Held: from 02/08/93 to 02/10/93

  12. Type of paper: Summary in proceedings

    Title: SEPARATION OF OXYTETRACYCLINE AND NEUTRAL PROTEINASE FROM FERMENTATION BROTH WITH AQUEOUS TWO_PHASE SYSTEM

    Authors:
    Bogdan, Stjepan
    Gosak, Darko
    Vasić-Rački, Đurđa (51631)
    Proceedings title: XIII. Skup hrvatskih kemičara
    Language: hrvatski
    Place: Zagreb
    Year: 1993
    Pages: from 326 to 326
    Meeting: XIII. Skup hrvatskih kemičara
    Held: from 02/08/93 to 02/10/93

  13. Type of paper: Summary in proceedings

    Title: MATHEMATICAL OPTIMIZATION OF MEDIUM COMPOSITION

    Authors:
    Husadžić, Bečir (11581)
    Vasić-Rački, Đurđa (51631)
    Proceedings title: XIII. Skup hrvatski kemičara
    Language: hrvatski
    Place: Zagreb
    Year: 1993
    Pages: from 335 to 335
    Meeting: XIII. Skup hrvatskih kemičara
    Held: from 02/08/93 to 02/10/93

  14. Type of paper: Summary in proceedings

    Title: AEROBIC MICROORGANISMS OXIDATION ACTIVITY DETERMINATION< EXPERIMENTAL METHOD DEVELOPMENT

    Authors:
    Pavlović, Nediljko
    Mihaljević, Krešo
    Plavljanić, Čedomir
    Vasić-Rački, Đurđa (51631)
    Proceedings title: XIII. Skup hrvatskih kemičara
    Language: hrvatski
    Place: Zagreb
    Year: 1993
    Pages: from 338 to 338
    Meeting: XIII. Skup hrvatskih kemičara
    Held: from 02/08/93 to 02/10/93

  15. Type of paper: Summary in proceedings

    Title: DYNAMIC OXYGEN ELECTRODE METHOD FOR MEASUREMENT OF kLa

    Authors:
    Plavljanić, Čedomir
    Husadžić, Bečir (11581)
    Vasić-Rački, Đurđa (51631)
    Proceedings title: XIII. Skup hrvatskih kemičara
    Language: hrvatski
    Place: Zagreb
    Year: 1993
    Pages: from 339 to 339
    Meeting: XIII. Skup hrvatskih kemičara
    Held: from 02/08/93 to 02/10/93

  16. Type of paper: Summary in proceedings

    Title: A SEMI_CONTINUOUS ADSORPTION SYSTEM FOR SEPARATION GLUCOSE/FRUCTOSE MIXTURES

    Authors:
    Matijašević, Ljubica (82036)
    Plavljanić, Čedomir
    Vasić-Rački, Đurđa (51631)
    Proceedings title: Sixth European Congress on Biotechnology
    Language: engleski
    Place: Firenza, Italija
    Year: 1993
    Pages: from 27 to 28
    Meeting: Sixth European Congress on Biotechnology
    Held: from 06/13/93 to 06/17/93
    Summary: An efficient separation of fructose from glucose may be achievedin semi-continuous adsorption system. In this work mixtures ofglucose and fructose are separated in columns packed with LewatitMDS 1368. The characteristics of equilibrium and kineticproperties of the adsorbent were determined from response curvesby liquid chromatography in the same column. The mathematicalmodel was developed to calculate concentration profiles in theadsorber where the adsorption isotherm are represented by twolinear equations independent of each other. On the basic of thismodel is an optimal ratio of process parameters (feed/eluent)where the effectiveness of separation in counter currentadsorption system can be improved.

  17. Type of paper: Summary in proceedings

    Title: EFFICIENCY OF SEPARATION OF GLUCOSE/FRUCTOSE MIXTURES

    Authors:
    Matijašević, Ljubica (82036)
    Plavljanić, Čedomir
    Vasić-Rački, Đurđa (51631)
    Proceedings title: CHISA '93
    Language: engleski
    Place: Prag, Češka
    Year: 1993
    Pages: from 131 to 131
    Meeting: The 11th International Congress of Chemical Engineering, Chemical Equipment Design and Automation
    Held: from 08/29/93 to 09/03/93
    Summary: In this work, chromatographic separation of glucose and fructosewith columns of exchange resins was studied by pulse responseexperiments. Moments analysis technique was used. Theexperimental eluation profiles of each sugar were used forresearch of influence of several parameters on the efficiency ofseparation such as length, diameter of column, retention time andvolumen of resin. The efficiency decreases as the flow ratebecomes lower at the longer column, while the efficiencyincreases to a certain flow rate at the shorter column.

  18. Type of paper: Summary in proceedings

    Title: CONTINUOUS SYNTHETIC REACTIONS OF OLEIC ACID ESTER CATALYZED BY LIPASEIN ENZYME MEMBRANE REACTOR

    Authors:
    Vasić-Rački, Đurđa (51631)
    Plavljanić, Čedomir
    Coric, Ljubica
    Proceedings title: SIXTH EUROPEAN CONGRESS ON BIOTECHNOLOGY
    Language: engleski
    Place: Firenza, Italija
    Year: 1993
    Pages: from 177 to 177
    Meeting: Sixth European Congress on Biotechnology
    Held: from 06/13/93 to 06/17/93
    Summary: Esterification as reversal of the hydrolytic reaction will befavored thermodinamically by the removal of water. Therefore theultrafiltration membrane reactor dividing oil and water phaseswas used. The same reactor enables the use of immobilized lipaseon the lipid-water interface with high reactivity toward theinsoluble substrate. A comparison of lipase activity in thereactor based on the lipase immobilized to the "lipid-water"interface to the reactor without membrane was made. The kineticstudies using oleic acid and glycerol as a model compounds forthe lipase catalyzed esterification were carried out with theenzyme membrane reactor system operated in a batch or continuousmode. A dynamic model of the process was developed. The modelbased on separately determined parameters for the kinetic data,membrane surface area and process conditions was verifiedexperimentally.

  19. Type of paper: Ph.D.

    Title: THE STUDY OF SEPARATION OF GLUCOSE/FRUCTOSE MIXTURES
    Faculty: kemijskog inženjerstva i tehnologije Zagrebačko
    Date of defense: 07/14/92
    Language: hrvatski
    Number of pages: 136
    Summary: In this work a simulated counter-current adsorption system wasused to separate two components with different adsorptionselectivity. The resin Lewatit MDS 1368, showed itself asadsorbent for the separation of glucose-fructose mixtures. The mathematical model was developed to calculate concentrationprofiles in the adsorbers where the adsorption isotherms wererepresented by linear equation. Concentration profiles werecalculated from dispersed flow model, and the validity of themodel was proposed experimentally confirmed. On the basis of thismodel a theoretical system analysis was carried out showing thatthere is an optimal ratio of process parameters (feed/eluent)where the effectiveness of separation in counter currentadsorption system can be improved.
    Keywords: adsorption isotherm, counter-current system, glucose/fructose separation


  20. Type of paper: Mentorship

    Title: IMMOBILIZATION OF MICROBIAL CELLS Streptomyces bambergiensis
    Faculty: kemijskog inženjerstva i tehnologije Zagrebačko
    Mentor: ADLER NEVENKA
    Date of defense: 03/27/91
    Number of pages: 94
    Author: Bijelić mr Jasenka
    Degree level: M.A.


  21. Type of paper: Mentorship

    Title: THE KINETIC STUDY OF ENZYMATIC ESTERIFICATION OF OLEIC ACID
    Faculty: kemijskog inženjerstva i tehnologije Zagrebačko
    Mentor: ADLER NEVENKA
    Date of defense: 01/27/94
    Number of pages: 76
    Author: Husić Irvaz
    Degree level: M.A.


  22. Type of paper: Mentorship

    Title: THE STUDY OF SEPARATION OF GLUCOSE/FRUCTOSE MIXTURES
    Faculty: kemijskog inženjerstva i tehnologije Zagrebačko
    Mentor: ADLER NEVENKA
    Date of defense: 07/14/92
    Number of pages: 136
    Author: Matijašević Ljubica
    Degree level: Ph.D.



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