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Author Jochems, P.; Mueller, T.; Satyawali, Y.; Diels, L.; Dejonghe, W.; Hanefeld, U. pdf  doi
openurl 
  Title Active site titration of immobilized beta-galactosidase for the determination of active enzymes Type A1 Journal article
  Year (down) 2015 Publication Biochemical engineering journal Abbreviated Journal  
  Volume 93 Issue Pages 137-141  
  Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)  
  Abstract In the present study, an active site titration method is demonstrated, to determine the amount of active enzyme (beta-galactosidase), immobilized on a support. Two types of supports were investigated, viz, amino acrylic resin and a mixed matrix membrane. Furthermore, 2',4'-dinitrophenyl 2-deoxy-2-fluoro-beta-D-galactopyranoside was used as an inhibitor for the active site titration of immobilized beta-galactosidase obtained from Kluyveromyces lactis. Using the active site titration, approximately 8.3 mg of active enzyme was found on 1 g of dried commercially available SPRIN imibond, which is an amino acrylic resin with covalently bound beta-galactosidase obtained from K. lactis. However, this method, in its present form, was not effective on the mixed matrix membranes due to the irreversible partial adsorption of the leaving group (2',4'-dinitrophenolate) by the membrane. This observation implied that it is important to investigate interactions between the support and the used inhibitor and leaving group. (C) 2014 Elsevier B.V. All rights reserved.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000347362100018 Publication Date 2014-10-23  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1369-703x; 1873-295x ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited Open Access  
  Notes Approved no  
  Call Number UA @ admin @ c:irua:123763 Serial 7417  
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Author Satyawali, Y.; Van Roy, S.; Roevens, A.; Meynen, V.; Mullens, S.; Jochems, P.; Doyen, W.; Cauwenberghs, L.; Dejonghe, W. pdf  doi
openurl 
  Title Characterization and analysis of the adsorption immobilization mechanism of \beta-galactosidase on metal oxide powders Type A1 Journal article
  Year (down) 2013 Publication RSC advances Abbreviated Journal  
  Volume 3 Issue 46 Pages 24054-24062  
  Keywords A1 Journal article; Laboratory of adsorption and catalysis (LADCA); Sustainable Energy, Air and Water Technology (DuEL)  
  Abstract Immobilization of the enzymes plays a vital role in enhancing their applicability in a wide range of applications, thus ensuring the use of sustainable enzymatic processes over the conventional chemical processes on an industrial scale. This study provides the background information for the selection and screening of inorganic metal oxide (MO) powders for their use as fillers in mixed matrix membranes for enzyme immobilization as the future aim. A total of 13 MOs, ranging in size from 0.01 μm to <5 μm, were tested for their performance as a support for enzyme (β-galactosidase) immobilization via adsorption. Alumina appeared to be the best performing MO with the amount and activity of the immobilized enzyme being 64 mg g−1 and up to 288 U g−1, respectively. The amount of immobilized enzyme on alumina (α-Al2O3 C and γ-Al2O3) was >3 times higher than ZrO2 (used as a reference MO in this study). Upon heat treatment at 900 °C, up to 15%, 52% and 42% decline was observed in the amount of immobilized enzyme in case of alumina metal oxides (MOs), ZrO2 and TiO2, respectively. The results suggested that both isoelectric point and surface area of the MO influence the immobilization. The most important observation in this study was that the bonding of the enzyme to the MO surface seems to be mediated by the bonding/interaction of the buffer to the enzyme.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000326745100030 Publication Date 2013-10-11  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2046-2069 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited Open Access  
  Notes Approved no  
  Call Number UA @ admin @ c:irua:111300 Serial 7607  
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Author Jochems, P.; Satyawali, Y.; van Roy, S.; Doyen, W.; Diels, L.; Dejonghe, W. pdf  doi
openurl 
  Title Characterization and optimization of \beta-galactosidase immobilization process on a mixed-matrix membrane Type A1 Journal article
  Year (down) 2011 Publication Enzyme and microbial technology Abbreviated Journal  
  Volume 49 Issue 6/7 Pages 580-588  
  Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)  
  Abstract β-Galactosidase is an important enzyme catalyzing not only the hydrolysis of lactose to the monosaccharides glucose and galactose but also the transgalactosylation reaction to produce galacto-oligosaccharides (GOS). In this study, β-galactosidase was immobilized by adsorption on a mixed-matrix membrane containing zirconium dioxide. The maximum β-galactosidase adsorbed on these membranes was 1.6 g/m2, however, maximal activity was achieved at an enzyme concentration of around 0.5 g/m2. The tests conducted to investigate the optimal immobilization parameters suggested that higher immobilization can be achieved under extreme parameters (pH and temperature) but the activity was not retained at such extreme operational parameters. The investigations on immobilized enzymes indicated that no real shift occurred in its optimal temperature after immobilization though the activity in case of immobilized enzyme was better retained at lower temperature (5 °C). A shift of 0.5 unit was observed in optimal pH after immobilization (pH 6.5 to 7). Perhaps the most striking results are the kinetic parameters of the immobilized enzyme; while the Michaelis constant (Km) value increased almost eight times compared to the free enzyme, the maximum enzyme velocity (Vmax) remained almost constant.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000298529600015 Publication Date 2011-06-26  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0141-0229 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited Open Access  
  Notes Approved no  
  Call Number UA @ admin @ c:irua:90060 Serial 7608  
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Author Jochems, P.; Satyawali, Y.; Diels, L.; Dejonghe, W. doi  openurl
  Title Enzyme immobilization on/in polymeric membranes : status, challenges and perspectives in biocatalytic membrane reactors (BMRs) Type A1 Journal article
  Year (down) 2011 Publication Green chemistry : cutting-edge research for a greener sustainable future Abbreviated Journal  
  Volume 13 Issue 7 Pages 1609-1623  
  Keywords A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL)  
  Abstract Immobilization of enzymes is beneficial in terms of improving the process economics by enabling enzyme re-use and enhancing overall productivity and robustness. Increasingly, membranes are thought to be good supports for enzyme immobilization. These resulting biocatalytic membranes are integrated in reactors known as biocatalytic membrane reactors (BMRs) which enable the integration of biocatalysis and separation. Often the available commercial membranes require modifications to make them suitable for enzyme immobilization. Different immobilization techniques can be used on such suitable membranes, but no general rules exist for making a choice between them. Despite the advantages of BMR application, there are some issues which need to be addressed in order to achieve up-scaling of such systems. In this review, the different aspects of enzyme immobilization on membranes are discussed to show the complexity of this interdisciplinary technology. In addition, the existing issues which require further investigation are highlighted.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000292450600002 Publication Date 2011-05-26  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1463-9262; 1463-9270 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited Open Access  
  Notes Approved no  
  Call Number UA @ admin @ c:irua:89567 Serial 7930  
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Author Satyawali, Y.; Seuntjens, P.; Van Roy, S.; Joris, I.; Vangeel, S.; Dejonghe, W.; Vanbroekhoven, K. pdf  doi
openurl 
  Title The addition of organic carbon and nitrate affects reactive transport of heavy metals in sandy aquifers Type A1 Journal article
  Year (down) 2011 Publication Journal of contaminant hydrology Abbreviated Journal  
  Volume 123 Issue 3/4 Pages 83-93  
  Keywords A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL)  
  Abstract Organic carbon introduction in the soil to initiate remedial measures, nitrate infiltration due to agricultural practices or sulphate intrusion owing to industrial usage can influence the redox conditions and pH, thus affecting the mobility of heavy metals in soil and groundwater. This study reports the fate of Zn and Cd in sandy aquifers under a variety of plausible in-situ redox conditions that were induced by introduction of carbon and various electron acceptors in column experiments. Up to 100% Zn and Cd removal (from the liquid phase) was observed in all the four columns, however the mechanisms were different. Metal removal in column K1 (containing sulphate), was attributed to biological sulphate reduction and subsequent metal precipitation (as sulphides). In the presence of both nitrate and sulphate (K2), the former dominated the process, precipitating the heavy metals as hydroxides and/or carbonates. In the presence of sulphate, nitrate and supplemental iron (Fe(OH)(3)) (K3), metal removal was also due to precipitation as hydroxides and/or carbonates. In abiotic column, K4, (with supplemental iron (Fe(OH)(3)), but no nitrate), cation exchange with soil led to metal removal. The results obtained were modeled using the reactive transport model PHREEQC-2 to elucidate governing processes and to evaluate scenarios of organic carbon, sulphate and nitrate inputs. (C) 2010 Elsevier B.V. All rights reserved.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000288979100001 Publication Date 2010-12-29  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0169-7722 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited Open Access  
  Notes Approved no  
  Call Number UA @ admin @ c:irua:105591 Serial 7419  
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Author De Wael, K.; Verstraete, A.; van Vlierberghe, S.; Dejonghe, W.; Dubruel, P.; Adriaens, A. url  openurl
  Title The electrochemistry of a gelatin modified gold electrode Type A1 Journal article
  Year (down) 2011 Publication International journal of electrochemical science Abbreviated Journal Int J Electrochem Sc  
  Volume 6 Issue 6 Pages 1810-1819  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract This paper discusses the electrochemical behaviour of gelatin coated gold electrodes in physiological pH conditions in a potential window −1.5 till 1.0 V vs SCE by performing cyclic voltammetry. A comparison is made between gelatin A and gelatin B, which have respectively a positive and a negative net charge at physiological pH. The deposition of gelatin onto the gold surface is confirmed by means of attenuated total reflection-infrared (ATR-IR) spectroscopic analyses.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos Publication Date  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1452-3981 ISBN Additional Links UA library record; WoS full record; WoS citing articles; WoS full record; WoS citing articles  
  Impact Factor 1.469 Times cited Open Access  
  Notes ; The authors would like to acknowledge the Flemish Institute for Technological Research (VITO, Belgium) and the Research Foundation-Flanders (FWO, Belgium) for the Ph.D. funding granted to Annelies Verstraete. Karolien De Wael and Sandra Van Vlierberghe are also grateful to the Research Foundation-Flanders (FWO, Belgium) for their postdoctoral fellowship. ; Approved Most recent IF: 1.469; 2011 IF: 3.729  
  Call Number UA @ admin @ c:irua:89617 Serial 5598  
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