Wyniki wyszukiwania - Biblioteka Nauki

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Membrany z octanu celulozy z immobilizowaną alpha-amylazą i glukoamylazą

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Turkiewicz B. , Rucka M. , Poźniak G.

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2002

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tom z. 47

215-222

PL

Celem pracy było dobranie warunków immobilizacji alpha-amylazy i glukoamylazy na membranach z octanu celulozy oraz przeprowadzenie reakcji hydrolizy roztworu skrobi. Enzym immobilizowano w warstwie podporowej bądź naskórkowej membrany, a następnie sieciowano aldehydem glutarowym lub formaldehydem. Badano wpływ rozmieszczenia enzymu oraz różniących się wielkością cząsteczek czynników sieciujących na aktywność i stabilność immobilizowanych enzymów.

EN

In this study alpha-amylase and glucoamylase immobilized on cellulose acetate membranes were applied for starch hydrolysis. The enzymes were on the surface or in the supporting layer of the membrane. After immoblization the membranes were treated with glutaraldehyde or formaldehyde. The obtained membranes were used for concentration of starch solution.

2

Immobilizacja enzymów. Część 1: Metody konwencjonalne

100%

Bryjdak J.

Wiadomości Chemiczne

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2004

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tom [Z] 58, 9-10

691--746

EN

Attractive features of biological systems include versatility, substrate selectivity, regio-, chemo-, and enantioselectivity as well as catalysis at ambient temperatures and pressure. However, the challenge facing bioprocesses is cost competitiveness with existing chemical process assets. The current expansion of industrial biocatalysis can be attributed to recent progress in molecular biology, advanced instrumentation, and engineering. Novel catalyst formulation based on technology such as directed evolution and enzyme immobilisation, has resulted in improved types of highly active and stable biocatalysts. In industrial biotransformations the immobilisation of enzymes on/in support is often chosen to enhance the stability and to simplify the biocatalyst recovery. The main purpose of this paper is to present a general picture of the immobilization techniques that is organised according to the two categories of methods, i.e., conventional methods (Part 1) and immobilisation in membrane reactors (Part 2). The intention of the first part is outline the common procedures that span from binding on carrier materials to incorporation into in situ prepared matrix in which binding forces vary between weak adsorption and covalent binding. Although the development of suitable immobilisation protocol often follows empirical guidelines, some general rules to facilitate proper applications are also presented. Immobilisation of enzymes means a deliberate restriction of the mobility of the enzyme, which can also affect mobility of the solutes. Thus it is mandatory to have basic knowledge of the essential contribution of the chemical forces and the physicochemical interactions during heterogeneous catalysis that is also discussed. Finally, the technological developments in the field of immobilised biocatalysts are presented that show possibility of a wide and more economical exploitation of enzymes in industry, medicine, and in the monitoring devices like the biosensors.

3

Immobilizacja enzymów. Część 2: Reaktory membranowe

75%

Bryjdak J.

Wiadomości Chemiczne

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2004

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tom [Z] 58, 9-10

747--780

EN

Biocatalysis involves the enzyme-promoted transformations of a substrate into useful product in either a homogeneous or heterogenous system. The separation of reactants from products and the recovery and reuse of the catalyst from the reaction mixture is an important step that significantly decreases the cost of the process. Membrane reactors constitute an attempt to integrate catalytic conversion, product separation and/or concentration, and catalyst recovery into a single operation unit that lowers the overall cost of final product. In an enzyme membrane reactor biocatalyst is immobilized within the reaction vessel or on/in a membrane (catalytic membrane). The paper shows two possibilities for immobilization of enzymes: 1 - localization of the soluble biocatalyst in a certain defined region of space of a membrane reactor; e.g. a volume of a reactor and separation unit or in lumen/shell side of ultrafiltration unit; 2 - adsorbed, deposited or bound (physically, via affinity ligand or by covalent attachment) to the surface of a membrane or entrapped within pores or material of the membrane. Arguments counting for membrane supported or soluble enzymes are also presented. Reactors with soluble biocatalyst in a volume of a membrane reactor seem be suited to carry out complex enzymatic transformations, involving several enzymes and cofactor regeneration. Membrane reactors with catalytic membranes are particularly appropriate for nonconventional media such as organic-aqueous two-phase systems and for production of biosensing elements of enzyme electrodes. It is therefore the intention of the paper to outline the common immobilization methods and technologies to facilitate proper applications of enzymes immobilized in a membrane reactor.

4

Membrany enzymatyczne

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Krajewska B.

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tom nr 6

20-22

PL

Zastosowanie biokatalizy stanowi przyjazną środowisku, energo i materiałooszczędną alternatywę dla konwencjonalnych procesów chemicznych. Kluczem do jej realizacji są trwałe preparaty enzymatyczne o dobrze określonych właściwościach. Otrzymuje się je najczęściej drogą immobilizacji enzymów na/w stałych nośnikach, m.in. membranach.

5

Immobilizacja enzymów na nośnikach sposobem na ukierunkowaną modyfikację właściwości biokatalizatorów

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Bolibok P. , Gembala J. , Wujak M. , Roszek K. , Terzyk A. P. , Wiśniewski M.

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2016

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tom T. 95, nr 11

2254--2258

PL

Przedstawiono problemy i ograniczenia stosowania immobilizowanych enzymów w procesach katalitycznych. Omówiono proces immobilizacji enzymów jako metodę poprawy ich stabilności w warunkach przemysłowych oraz wybrane techniki immobilizacji i nośniki enzymów.

EN

A review, with 42 refs., of polymeric enzyme carriers and nanocarriers (diamond, C tubes, graphene, graphene oxide) and practical uses of the immobilized enzymes.

6

Immobilizacja naringinazy z Penicillium decumbens na magnetycznych nośnikach polisacharydowych

75%

Bodakowska-Boczniewicz J. , Garncarek Z.

Prace Naukowe Uniwersytetu Ekonomicznego we Wrocławiu

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2018

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nr 542

9-24

PL

Naringinaza z Penicillium decumbens została unieruchomiona na aktywowanych nośnikach polisacharydowych o właściwościach magnetycznych. W badaniach wykorzystano gumę guar, karobową, tragakantową, ksantanową oraz karagenianin. Nośniki otrzymano poprzez pokrycie mikrocząsteczek magnetytu (Fe3O4) polisacharydem, a następnie aktywując je aldehydem glutarowym lub polietylenoiminą. Celem niniejszej pracy była immobilizacja naringinazy z P. decumbens na magnetycznych nośnikach polisacharydowych oraz charakterystyka otrzymanego biokatalizatora. Najwyższą aktywność enzymu uzyskano poprzez immobilizację naringinazy na nośniku otrzymanym na bazie gumy karobowej aktywowanej polietylenoiminą. Immobilizacja naringinazy na tak otrzymanym nośniku wpływała na zmniejszenie optymalnej wartości pH oraz optymalnej temperatury aktywności badanego enzymu. Immobilizacja powodowała zwiększenie wartości stałej Michaelisa oraz zmniejszenie maksymalnej szybkości reakcji w porównaniu z enzymem wolnym.

EN

Naringinase from Penicillium decumbens was immobilized on activated polysaccharide supported with magnetic properties. Magnetic microparticles were prepared by coating a magnetite (Fe3O4) with a polysaccharide followed by activating with glutaraldehyde or polyethyleneimine. Guar gums, locust bean, tragacanth, xanthan and carrageenan were used in the research. The main goals of this work were the immobilization of naringinase on magnetic polysaccharide carriers and the characterization of such immobilized enzyme. The naringinase immobilized on a carrier obtained on the basis of carob gum activated with polyethyleneimine had the highest activity. The immobilization of the naringinase on the carrier thus obtained influenced the reduction of the optimal pH value and the optimal temperature. Immobilization increased the Michaelis constant value and decreased the maximum reaction rate, as compared to the free enzyme.

7

Immobilizowane alfa-amylazy i celulazy w zastosowaniach praktycznych

63%

Chałupka Z.

Wiadomości Chemiczne

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2016

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tom [Z] 70, 5-6

369--389

EN

Today, more and more products made in biotechnological processes involving enzymes. The stability of the enzyme under process conditions are subjected to the immobilization on solid supports, which leads to a heterogeneous biocatalyst that can be used in several cycles or continuous processes. The article discusses the techniques presented in the literature immobilization of enzymes hydrolyzing starch and cellulose. Includes the method of immobilization in/on polymer and inorganic carriers and different ways of binding of the enzyme to a solid support. Particular attention is focused on mesoporous silica (mesoporous silica) (SBA-15) as a very attractive media for biocatalysts. Starch and cellulose are the main components of biomass, which is seen as an alternative raw material for ethanol production, i.e. second generation biofuels. Developing an effective biocatalyst for the conversion of biomass is the challenge of the XXI century.