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Sample records for pixe-aided immobilization study

  1. A comparative study of free and immobilized soybean and horseradish peroxidases for 4-chlorophenol removal: protective effects of immobilization.

    Science.gov (United States)

    Bódalo, Antonio; Bastida, Josefa; Máximo, M Fuensanta; Montiel, M Claudia; Gómez, María; Murcia, M Dolores

    2008-10-01

    Horseradish peroxidase (HRP) and soybean peroxidase (SBP) were covalently immobilized onto aldehyde glass through their amine groups. The activity yield and the protein content for the immobilized SBP were higher than for the immobilized HRP. When free and immobilized peroxidases were tested for their ability to remove 4-chlorophenol from aqueous solutions, the removal percentages were higher with immobilized HRP than with free HRP, whereas immobilized SBP needs more enzyme to reach the same conversion than free enzyme. In the present paper the two immobilized derivatives are compared. It was found that at an immobilized enzyme concentration in the reactor of 15 mg l(-1), SBP removed 5% more of 4-chlorophenol than HRP, and that a shorter treatment was necessary. Since immobilized SBP was less susceptible to inactivation than HRP and provided higher 4-chlorophenol elimination, this derivative was chosen for further inactivation studies. The protective effect of the immobilization against the enzyme inactivation by hydrogen peroxide was demonstrated.

  2. STUDY ON IMMOBILIZED THERMOLYSIN WITH CELLULOSE AS CARRIER

    Institute of Scientific and Technical Information of China (English)

    TaoGuoliang; ZhuoRenxi; 等

    1996-01-01

    With cellulose as carrier,immobilized thermolysin HE I and HE Ⅱ were prepared by diazo coupling or glutaraldehyde crosslinking reaction.Using casein as a substrate,the activity recovery of immobilized thermolysin HE I and HE Ⅱ reach 34.5% and 29%,respectively.Some factors which affect the activity of the immobilized thermolysin such as temperature,medium pH,EDTA and calcium acetate were studied.At the same time,the thermal stability and storage stability of the immobilized thermolysin were also investigated.

  3. Immobilizing live Escherichia coli for AFM studies of surface dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Lonergan, N.E.; Britt, L.D.; Sullivan, C.J., E-mail: sullivcj@evms.edu

    2014-02-01

    Atomic force microscopy (AFM) is a probe-based technique that permits high resolution imaging of live bacterial cells. However, stably immobilizing cells to withstand the probe-based lateral forces remains an obstacle in AFM mediated studies, especially those of live, rod shaped bacteria in nutrient media. Consequently, AFM has been under-utilized in the research of bacterial surface dynamics. The aim of the current study was to immobilize a less adherent Escherichia coli strain in a method that both facilitates AFM imaging in nutrient broth and preserves overall cell viability. Immobilization reagents and buffers were systematically evaluated and the cell membrane integrity was monitored in all sample preparations. As expected, the biocompatible gelatin coated surfaces facilitated stable cell attachment in lower ionic strength buffers, yet poorly immobilized cells in higher ionic strength buffers. In comparison, poly-L-lysine surfaces bound cells in both low and high ionic strength buffers. The benefit of the poly-L-lysine binding capacity was offset by the compromised membrane integrity exhibited by cells on poly-L-lysine surfaces. However, the addition of divalent cations and glucose to the immobilization buffer was found to mitigate this unfavorable effect. Ultimately, immobilization of E. coli cells on poly-L-lysine surfaces in a lower ionic strength buffer supplemented with Mg{sup 2+} and Ca{sup 2+} was determined to provide optimal cell attachment without compromising the overall cell viability. Cells immobilized in this method were stably imaged in media through multiple division cycles. Furthermore, permeability assays indicated that E. coli cells recover from the hypoosmotic stress caused by immobilization in low ionic strength buffers. Taken together, this data suggests that stable immobilization of viable cells on poly-L-lysine surfaces can be accomplished in lower ionic strength buffers that are supplemented with divalent cations for membrane

  4. Immobilizing live Escherichia coli for AFM studies of surface dynamics.

    Science.gov (United States)

    Lonergan, N E; Britt, L D; Sullivan, C J

    2014-02-01

    Atomic force microscopy (AFM) is a probe-based technique that permits high resolution imaging of live bacterial cells. However, stably immobilizing cells to withstand the probe-based lateral forces remains an obstacle in AFM mediated studies, especially those of live, rod shaped bacteria in nutrient media. Consequently, AFM has been under-utilized in the research of bacterial surface dynamics. The aim of the current study was to immobilize a less adherent Escherichia coli strain in a method that both facilitates AFM imaging in nutrient broth and preserves overall cell viability. Immobilization reagents and buffers were systematically evaluated and the cell membrane integrity was monitored in all sample preparations. As expected, the biocompatible gelatin coated surfaces facilitated stable cell attachment in lower ionic strength buffers, yet poorly immobilized cells in higher ionic strength buffers. In comparison, poly-l-lysine surfaces bound cells in both low and high ionic strength buffers. The benefit of the poly-l-lysine binding capacity was offset by the compromised membrane integrity exhibited by cells on poly-l-lysine surfaces. However, the addition of divalent cations and glucose to the immobilization buffer was found to mitigate this unfavorable effect. Ultimately, immobilization of E. coli cells on poly-l-lysine surfaces in a lower ionic strength buffer supplemented with Mg(2+) and Ca(2+) was determined to provide optimal cell attachment without compromising the overall cell viability. Cells immobilized in this method were stably imaged in media through multiple division cycles. Furthermore, permeability assays indicated that E. coli cells recover from the hypoosmotic stress caused by immobilization in low ionic strength buffers. Taken together, this data suggests that stable immobilization of viable cells on poly-l-lysine surfaces can be accomplished in lower ionic strength buffers that are supplemented with divalent cations for membrane stabilization

  5. Immobilized enzyme studies in a microscale bioreactor.

    Science.gov (United States)

    Jones, Francis; Forrest, Scott; Palmer, Jim; Lu, Zonghuan; Elmore, John; Elmore, Bill B

    2004-01-01

    Novel microreactors with immobilized enzymes were fabricated using both silicon and polymer-based microfabrication techniques. The effectiveness of these reactors was examined along with their behavior over time. Urease enzyme was successfully incorporated into microchannels of a polymeric matrix of polydimethylsiloxane and through layer-bylayer self-assembly techniques onto silicon. The fabricated microchannels had cross-sectional dimensions ranging from tens to hundreds of micrometers in width and height. The experimental results for continuous-flow microreactors are reported for the conversion of urea to ammonia by urease enzyme. Urea conversions of >90% were observed.

  6. Study of CRP immobilization on nanostructured silicon

    Energy Technology Data Exchange (ETDEWEB)

    Simion, Monica, E-mail: moni304ro@yahoo.com [National Institute for Research and Development in Microtechnologies (IMT - Bucharest), 32B Erou Iancu Nicolae Street, 72996 Bucharest (Romania); Ruta, Lavinia L.; Matache, Mihaela [University of Bucharest, Department of Chemistry, Division of Organic Chemistry, 90-92 Panduri Street, 050663 Bucharest (Romania); Kleps, Irina; Miu, Mihaela [National Institute for Research and Development in Microtechnologies (IMT - Bucharest), 32B Erou Iancu Nicolae Street, 72996 Bucharest (Romania); Paraschivescu, Codruta C. [University of Bucharest, Department of Chemistry, Division of Organic Chemistry, 90-92 Panduri Street, 050663 Bucharest (Romania); Bragaru, Adina; Ignat, Teodora [National Institute for Research and Development in Microtechnologies (IMT - Bucharest), 32B Erou Iancu Nicolae Street, 72996 Bucharest (Romania)

    2010-05-25

    C-reactive protein (CRP) is a phylogenetically highly conserved plasma protein, which is widely used as an indicator of inflammatory states due to rapid increase of its plasma concentration up to 1000 times compared to normal values. Detection of CRP levels in a rapid, simultaneous and multiplex format is therefore of great interest for diagnostics. Microarray technology could provide such a multiplex format of CRP levels detection. Different nanostructured porous silicon (PS) surfaces were obtained and used for the immobilization of CRP and anti-human CRP antibodies in order to achieve an optimum microarray assay. Comparative analysis of the attachment degree and preservation of the biomolecules activity on the silicon surfaces and functionalized glass slides is also described.

  7. Preliminary studies on immobilization of lipase using chicken eggshell

    Science.gov (United States)

    Salleh, S.; Serri, N. A.; Hena, S.; Tajarudin, H. A.

    2016-06-01

    A few advantages of enzyme immobilization are reusability of expensive enzyme, improvement of stability and activity compared to crude enzyme. Various organic components can be used as carrier for enzyme immobilization such as chicken eggshell. It can be used as a carrier for immobilization as its mineral component mostly contains of calcium carbonate. In the present study, Tributyrin method was used to test enzyme activity of Rhizomucour Miehei, Candida Antarctica and Candida Rugosa. Rhizomucour Miehei shows the highest enzyme activity (360.8 mol/min/mL lipase) and was used in further experiment. Experiment was continued to study incubation time for lipase immobilization on eggshell (1-4 hours) and reaction time of esterification of sugar ester (0-72 hours). Two hours incubation time for lipase immobilization was observed and gives the highest yield of sugar ester (78.13%). Fructose and stearic acid as substrate was used for the production of sugar ester. The highest percentage of sugar ester production was shown at 36 hours of reaction time.

  8. In situ ellipsometric study of surface immobilization of flagellar filaments

    Energy Technology Data Exchange (ETDEWEB)

    Kurunczi, S., E-mail: kurunczi@mfa.kfki.hu [Department of Photonics, Research Institute for Technical Physics and Materials Science, H-1121, Konkoly Thege Miklos ut 29-33, Budapest (Hungary); Nemeth, A.; Huelber, T. [Department of Photonics, Research Institute for Technical Physics and Materials Science, H-1121, Konkoly Thege Miklos ut 29-33, Budapest (Hungary); Kozma, P. [Department of Photonics, Research Institute for Technical Physics and Materials Science, H-1121, Konkoly Thege Miklos ut 29-33, Budapest (Hungary); Department of Nanotechnology, Research Institute of Chemical and Process Engineering, Faculty of Information Technology, University of Pannonia, Egyetem u. 10, Veszprem, H-8200 (Hungary); Petrik, P. [Department of Photonics, Research Institute for Technical Physics and Materials Science, H-1121, Konkoly Thege Miklos ut 29-33, Budapest (Hungary); Jankovics, H. [Department of Nanotechnology, Research Institute of Chemical and Process Engineering, Faculty of Information Technology, University of Pannonia, Egyetem u. 10, Veszprem, H-8200 (Hungary); Sebestyen, A. [Department of Photonics, Research Institute for Technical Physics and Materials Science, H-1121, Konkoly Thege Miklos ut 29-33, Budapest (Hungary); Department of Nanotechnology, Research Institute of Chemical and Process Engineering, Faculty of Information Technology, University of Pannonia, Egyetem u. 10, Veszprem, H-8200 (Hungary); Vonderviszt, F. [Department of Photonics, Research Institute for Technical Physics and Materials Science, H-1121, Konkoly Thege Miklos ut 29-33, Budapest (Hungary); Department of Nanotechnology, Research Institute of Chemical and Process Engineering, Faculty of Information Technology, University of Pannonia, Egyetem u. 10, Veszprem, H-8200 (Hungary); Institute of Enzymology, Karolina ut 29-33, Budapest, H-1113 (Hungary); and others

    2010-10-15

    Protein filaments composed of thousands of subunits are promising candidates as sensing elements in biosensors. In this work in situ spectroscopic ellipsometry is applied to monitor the surface immobilization of flagellar filaments. This study is the first step towards the development of layers of filamentous receptors for sensor applications. Surface activation is performed using silanization and a subsequent glutaraldehyde crosslinking. Structure of the flagellar filament layers immobilized on activated and non-activated Si wafer substrates is determined using a two-layer effective medium model that accounted for the vertical density distribution of flagellar filaments with lengths of 300-1500 nm bound to the surface. The formation of the first interface layer can be explained by the multipoint covalent attachment of the filaments, while the second layer is mainly composed of tail pinned filaments floating upwards with the free parts. As confirmed by atomic force microscopy, covalent immobilization resulted in an increased surface density compared to absorption.

  9. Study on Algae Removal by Immobilized Biosystem on Sponge

    Institute of Scientific and Technical Information of China (English)

    PEI Haiyan; HU Wenrong

    2006-01-01

    In this study, sponges were used to immobilize domesticated sludge microbes in a limited space, forming an immobilized biosystem capable of algae and microcystins removal. The removal effects on algae, microcystins and UV260 of this biosystem and the mechanism of algae removal were studied. The results showed that active sludge from sewage treatment plants was able to remove algae from a eutrophic lake's water after 7 d of domestication. The removal efficiency for algae,organic matter and microcystins increased when the domesticated sludge was immobilized on sponges. When the hydraulic retention time (HRT) was 5h, the removal rates of algae, microcystins and UV260 were 90%, 94.17% and 84%, respectively.The immobilized biosystem consisted mostly of bacteria, the Ciliata and Sarcodina protozoans and the Rotifer metazoans.Algal decomposition by zoogloea bacteria and preying by microcreatures were the two main modes of algal removal, which occurred in two steps: first, absorption by the zoogloea; second, decomposition by the zoogloea bacteria and the predacity of the microcreatures.

  10. Stability studies of immobilized lipase on rice husk and eggshell membrane

    Science.gov (United States)

    Abdulla, R.; Sanny, S. A.; Derman, E.

    2017-06-01

    Lipase immobilization for biodiesel production is gaining importance day by day. In this study, lipase from Burkholderia cepacia was immobilized on activated support materials namely rice husk and egg shell membrane. Both rice husk and eggshell membrane are natural wastes that holds a lot of potential as immobilization matrix. Rice husk and eggshell membrane were activated with glutaraldehyde. Lipase was immobilized on the glutaraldehyde-activated support material through adsorption. Immobilization efficiency together with enzyme activity was observed to choose the highest enzyme loading for further stability studies. Immobilization efficiency of lipase on rice husk was 81 as compared to an immobilization efficiency of 87 on eggshell membrane. Immobilized lipase on eggshell membrane exhibited higher enzyme activity as compared to immobilized lipase on rice husk. Eggshell membrane also reported higher stability than rice husk as immobilization matrix. Both types of immobilized lipase retatined its activity after ten cycles of reuse. In short, eggshell membrane showed to be a better immobilization platform for lipase as compared to rice husk. However, with further improvement in technique of immobilization, the stability of both types of immobilized lipase can be improved to a greater extent.

  11. Experimental study on cesium immobilization in struvite structures.

    Science.gov (United States)

    Wagh, Arun S; Sayenko, S Y; Shkuropatenko, V A; Tarasov, R V; Dykiy, M P; Svitlychniy, Y O; Virych, V D; Ulybkina, Е А

    2016-01-25

    Ceramicrete, a chemically bonded phosphate ceramic, was developed for nuclear waste immobilization and nuclear radiation shielding. Ceramicrete products are fabricated by an acid-base reaction between magnesium oxide and mono potassium phosphate that has a struvite-K mineral structure. In this study, we demonstrate that this crystalline structure is ideal for incorporating radioactive Cs into a Ceramicrete matrix. This is accomplished by partially replacing K by Cs in the struvite-K structure, thus forming struvite-(K, Cs) mineral. X-ray diffraction and thermo-gravimetric analyses are used to confirm such a replacement. The resulting product is non-leachable and stable at high temperatures, and hence it is an ideal matrix for immobilizing Cs found in high-activity nuclear waste streams. The product can also be used for immobilizing secondary waste streams generated during glass vitrification of spent fuel, or the method described in this article can be used as a pretreatment method during glass vitrification of high level radioactive waste streams. Furthermore, it suggests a method of producing safe commercial radioactive Cs sources.

  12. Laccase immobilization over multi-walled carbon nanotubes: Kinetic, thermodynamic and stability studies.

    Science.gov (United States)

    Tavares, Ana P M; Silva, Cláudia G; Dražić, Goran; Silva, Adrián M T; Loureiro, José M; Faria, Joaquim L

    2015-09-15

    The biocatalytic performance of immobilized enzyme systems depends mostly on the intrinsic properties of both biomolecule and support, immobilization technique and immobilization conditions. Multi-walled carbon nanotubes (MWCNTs) possess unique features for enzyme immobilization by adsorption. Enhanced catalytic activity and stability can be achieved by optimization of the immobilization conditions and by investigating the effect of operational parameters. Laccase was immobilized over MWCNTs by adsorption. The hybrid material was characterized by Fourier transformed infrared (FTIR) spectroscopy, scanning and transmission electron microscopy (SEM and TEM, respectively). The effect of different operational conditions (contact time, enzyme concentration and pH) on laccase immobilization was investigated. Optimized conditions were used for thermal stability, kinetic, and storage and operational stability studies. The optimal immobilization conditions for a laccase concentration of 3.75μL/mL were a pH of 9.0 and a contact time of 30min (522 Ulac/gcarrier). A decrease in the thermal stability of laccase was observed after immobilization. Changes in ΔS and ΔH of deactivation were found for the immobilized enzyme. The Michaelis-Menten kinetic constant was higher for laccase/MWCNT system than for free laccase. Immobilized laccase maintained (or even increased) its catalytic performance up to nine cycles of utilization and revealed long-term storage stability.

  13. Biochemical studies on immobilized fungal β-glucosidase

    Directory of Open Access Journals (Sweden)

    S. A. Ahmed

    2013-12-01

    Full Text Available β-Glucosidase from Aspergillus niger was immobilized on sponge by covalent binding through a spacer group (glutaraldehyde. Sponge-immobilized enzyme had the highest immobilization yield (95.67% and retained 63.66% of the original activity exhibited by the free enzyme. The optimum pH of the immobilized enzyme remains almost the same as for the free enzyme (pH 4.0. The optimum temperature for β-glucosidase activity was increased by 10 ºC after immobilization. The activation energy (Ea of the immobilized β-glucosidase was lower than the free enzyme (3.34 and 4.55 kcal/mol, respectively. Immobilized β-glucosidase exhibited great thermal stability and retained all the initial activity after incubation at 55 ºC for 2 h; however, the free enzyme retained 89.25% under the same condition. The calculated half-life (t½ value of heat inactivation of immobilized enzyme at 60, 65 and 70 ºC was 213.62, 72.95 and 56.80 min, respectively, whereas at these temperatures the free enzyme was less stable (half-life of 200.0, 55.31 and 49.5 min, respectively. The deactivation rate constant at 65 ºC for the immobilized β-glucosidase is 9.5x10-3/ min, which was lower than that of the free form (12.53x10-3/ min. The immobilization process improved the pH stability of the enzyme (immobilized and free enzyme retained 69.35 and 39.86%, respectively, of their initial activity after 45 min at pH 7.5. The effect of some chemical substances on the activity of the immobilized and free β-glucosidase has been investigated. In the presence of sodium dodecyl sulfate (SDS and p-chloromercuri benzoate (p-CMB the immobilized enzyme retained 36.13 and 45.34%, respectively, of the initial activity, which is higher than that of free enzyme (13.71 and 1.61%, respectively. The Michaelis constant (Km value of the free enzyme was 40.0 mM, while the apparent Km value for the immobilized enzyme was 46.51 mM. The maximum reaction rate (v max of immobilized β-glucosidase was smaller

  14. Comperative study of catalase immobilization on chitosan, magnetic chitosan and chitosan-clay composite beads.

    Science.gov (United States)

    Başak, Esra; Aydemir, Tülin; Dinçer, Ayşe; Becerik, Seda Çınar

    2013-12-01

    Catalase was immobilized on chitosan and modified chitosan. Studies were carried out on free-immobilized catalase concerning the determination of optimum temperature, pH, thermal, storage stability, reusability, and kinetic parameters. Optimum temperature and pH for free catalase and catalase immobilized were found as 35°C and 7.0, respectively. After 100 times of repeated tests, the immobilized catalases on chitosan-clay and magnetic chitosan maintain over 50% and 60% of the original activity, respectively. The ease of catalase immobilization on low-cost matrices and good stability upon immobilization in the present study make it a suitable product for further use in the food industry.

  15. STUDIES ON IMMOBILIZED GLUCOSE OXIDASE BY DIETHYLAMINOETHYL CELLULOSE COMPLEXES

    Institute of Scientific and Technical Information of China (English)

    WANG Lingzhi; YUAN Hong; FANG Shibi; JIANG Yingyan

    1993-01-01

    The properties of immobilized glucose oxidase (GOD) by the complexes of diethylaminoethyl cellu -lose(DEAEC) with different polymers, such as polymethylacrylic acid (PMAA), polyacrylic acid (PAA), polystyrene sulfonic acid (PSSA), polyvinylalcohol (PVA), polyethylene oxide (PEO)and styrene-maleic acid copolymer (PSMA) were investigated. The activity of immobilized GOD was obviously influenced by the component of the DEAEC complexes. The relative activity of the immobilized GOD reached to maximum and over 90% of the native GOD. when the DEAEC-PMAA DEAEC-PAA complexes were used as a carrier with the molar ratio of DEAEC and polyacid of about one. Michaelis constants (Km) of the immobilized enzymes of DEAEC-GOD-PMAA and DEAEC-GOD-PAA were determined to be 1.25 and 1.00, respectively. Moreover, the immobilized GOD has a good storage stability and cyclic life.

  16. Preliminary study on the dye removal efficacy of immobilized marine ...

    African Journals Online (AJOL)

    SAM

    2014-05-28

    May 28, 2014 ... immobilized marine and freshwater microalgal beads ... Discharge of textile wastewater containing toxic dyes can adversely affect aquatic organisms and human health. .... the bioavailability of pollutants like metals, dye.

  17. Catalytic Properties and Immobilization Studies of Catalase from Malva sylvestris L.

    Directory of Open Access Journals (Sweden)

    G. Arabaci

    2013-01-01

    Full Text Available Catalase was partially purified from Malva sylvestris L. and immobilized onto chitosan. Then, its catalytic properties were investigated. (NH42SO4 precipitation and dialysis were performed in the extracted enzyme. Further purification was performed with sephadex G-200 column. Kinetic studies of the purified enzyme activity were measured and characterized. The inhibitory effects of KCN, NaN3, CuSO4, and EDTA on M. sylvestris L. catalase activity were observed except NaCl. Furthermore, M. sylvestris L. catalase was immobilized covalently with glutaraldehyde onto chitosan particles. The pH and temperature optima as well as the changes in the kinetics (Km, Vmax of the immobilized and free M. sylvestris L. catalase were determined. The Km value for immobilized catalase (23.4 mM was higher than that of free enzyme (17.6 mM. Optimum temperature was observed higher than that of the free enzyme. The optimum pH was the same for both free and immobilized catalases (pH 7.50. Immobilized catalase showed higher storage and thermal stabilities than free catalases. Free catalase lost all its activity within 60 days whereas immobilized catalase lost 45% of its activity during the same incubation period at 4°C. The remaining immobilized catalase activity was about 70% after 8 cycles of batch operations.

  18. Studies on Manganese Peroxidase Immobilized in Gelatin-containing Microemulsion-based Gels

    Institute of Scientific and Technical Information of China (English)

    SONG Shao-fang; LUAN Yu-xia; SU Xiu-rong

    2005-01-01

    The immobilized technique of manganese peroxidase(MnP) in gelatin-containing microemulsion-based gels and the effects of storage time and reuse times on its catalytic activity were studied. The results show that the MnP immobilized together with Mn2+ and H2O2 could effectively oxidize syringaldazine in n-heptane. The immobilized MnP still had a high catalytic activity after one-month storage under a freezing condition. The reuse times have a relation to the amount of the immobilized H2O2. When the amount of the immobilized H2O2 is sufficient, the microemulsion-based gels containing MnP could be used many times.

  19. Study on Immobilized Lipase Catalyzed Transesterification Reaction of Tung Oil

    Institute of Scientific and Technical Information of China (English)

    XU Gui-zhuan; ZHANG Bai-liang; LIU Sheng-yong; YUE Jian-zhi

    2006-01-01

    The transesterification reaction conditions of tung oil with methanol have been studied in this article, with immobilized lipase NOVO435 as catalyst. The response surface methodology was used to optimize the transesterification reaction of tung oil in a nonsolvent system. The optimal conditions were rotation rate 200 r/min, molar ratio of methanol to oil 2.2:1,reaction temperature 43℃, and the catalyst amount 14% (based on the weight of oil). After reacting for 18 h, 67.5% of the oil was converted to its corresponding methyl esters (the theoretical ester conversion was 73.3%). The lipase was washed by organic solvents after each reaction and was reused again. The esters conversion of tung oil was decreased by 6% after the lipase was reused for 120 h. The theoretical amount of methanol was added in two steps, 85% ester conversion was obtained after 36 h of reaction (theoretical ester conversion was 100%). The molar ratio of methanol to oil, the catalyst amount, the reaction temperature, and reaction time were all highly significant factors, and there was a relative significant interaction between every two factors.

  20. Studies of Immobilized Homogeneous Metal Catalysts on Silica Supports

    Energy Technology Data Exchange (ETDEWEB)

    Stanger, Keith James [Iowa State Univ., Ames, IA (United States)

    2003-01-01

    The tethered, chiral, chelating diphosphine rhodium complex, which catalyzes the enantioselective hydrogenation of methyl-α-acetamidocinnamate (MAC), has the illustrated structure as established by 31P NMR and IR studies. Spectral and catalytic investigations also suggest that the mechanism of action of the tethered complex is the same as that of the untethered complex in solution. The rhodium complexes, [Rh(COD)H]4, [Rh(COD)2]+BF4-, [Rh(COD)Cl]2, and RhCl3• 3H2O, adsorbed on SiO2 are optimally activated for toluene hydrogenation by pretreatment with H2 at 200 C. The same complexes on Pd-SiO2 are equally active without pretreatments. The active species in all cases is rhodium metal. The catalysts were characterized by XPS, TEM, DRIFTS, and mercury poisoning experiments. Rhodium on silica catalyzes the hydrogenation of fluorobenzene to produce predominantly fluorocyclohexane in heptane and 1,2-dichloroethane solvents. In heptane/methanol and heptane/water solvents, hydrodefluorination to benzene and subsequent hydrogenation to cyclohexane occurs exclusively. Benzene inhibits the hydrodefluorination of fluorobenzene. In DCE or heptane solvents, fluorocyclohexane reacts with hydrogen fluoride to form cyclohexene. Reaction conditions can be chosen to selectively yield fluorocyclohexane, cyclohexene, benzene, or cyclohexane. The oxorhenium(V) dithiolate catalyst [-S(CH2)3s-]Re(O)(Me)(PPh3) was modified by linking it to a tether that could be attached to a silica support. Spectroscopic investigation and catalytic oxidation reactivity showed the heterogenized catalyst's structure and reactivity to be similar to its homogeneous analog. However, the immobilized catalyst offered additional advantages of recyclability, extended stability, and increased resistance to deactivation.

  1. Studies on the surface coat of Paramecium aurelia. II. Relationship to the immobilization antigen.

    Science.gov (United States)

    Wyroba, E

    1977-07-11

    Correlations between the presence of surface coat and immobilization antigen of Paramecium tetraurelia were studied. Supravital, partial removal of the surface coat resulted in accelerated response of monobacterially and axenically grown cells to the homologous antiserum. Ciliates pretreated with trypsin or pronase (0.5 mg/ml for 45 min at 0-4 degrees C) were immobilized approximately twice as fast as untreated control cells. The probable localization of at least part, of the immobilization antigen within the surface coat of P. tetraurelia is discussed.

  2. Comparative study of random and oriented antibody immobilization techniques on the binding capacity of immunosensor.

    Science.gov (United States)

    Kausaite-Minkstimiene, A; Ramanaviciene, A; Kirlyte, J; Ramanavicius, A

    2010-08-01

    A comparative study of four different antibody immobilization techniques that are suitable for modification of surface plasmon resonance (SPR) chip (SPR-chip) is reported. Antibodies against human growth hormone (anti-HGH) were used as the model system. The evaluated SPR-chip modification techniques were (i) random immobilization of intact anti-HGH (intact-anti-HGH) via self-assembled monolayer (SAM) based on 11-mercaptoundecanoic acid (MUA); (ii) random immobilization of intact-anti-HGH within carboxymethyl dextran (CMD) hydrogel by direct covalent amine coupling technique; (iii) oriented coupling of intact-anti-HGH via Fc-fragment to protein-G layer assembled on SAM consisting of MUA (MUA/pG); (iv) oriented immobilization of fragmented anti-HGH antibodies (frag-anti-HGH) via their native thiol-groups directly coupled to the gold. To liberate these thiol groups, the intact-anti-HGH was chemically "divided" into two frag-anti-HGH fragments by chemical reduction with 2-mercaptoethylamine (2-MEA). Optimal concentration of 2-MEA for preparation of anti-HGH was 15 mM. The surface concentration of immobilized antibodies and the antigen binding capacity for all four differently modified SPR-chips was evaluated and compared. The maximum surface concentration of immobilized intact-anti-HGH was obtained by immobilizing the antibody within CMD-hydrogel. The maximal antigen binding capacity was obtained by SPR-chip based on intact-anti-HGH immobilized via MUA/pG. The immobilization based on application of frag-anti-HGH was found to be the most suitable for design of SPR-immunosensor for HGH detection, due to its sufficient antigen binding capacity, simplicity, and low cost in respect to the currently evaluated techniques.

  3. Study on the Characterization and Kinetics of Immobilized Lipase

    Institute of Scientific and Technical Information of China (English)

    B.Wang; Y.P.Wang; Y.L.Wei

    2007-01-01

    1 Rusults Most enzymes, including lipase, play a key role in biotechnology, but their usage is quite limited because of poor recovery, yield, limited re-usability and rapid inactivation in the soluble state. Immobilization enzymes offer advantages over free enzymes because of the availability of a choice of batch or continuous processes, rapid termination of reactions, controlled product formation, ease of enzyme removal from the reaction mixture, and adaptability to various engineering designs.In this ...

  4. Functionalized graphene sheets as immobilization matrix for Fenugreek β-amylase: enzyme kinetics and stability studies.

    Directory of Open Access Journals (Sweden)

    Garima Srivastava

    Full Text Available β-Amylase finds application in food and pharmaceutical industries. Functionalized graphene sheets were customised as a matrix for covalent immobilization of Fenugreek β-amylase using glutaraldehyde as a cross-linker. The factors affecting the process were optimized using Response Surface Methodology based Box-Behnken design of experiment which resulted in 84% immobilization efficiency. Scanning and Transmission Electron Microscopy (SEM, TEM and Fourier Tansform Infrared (FTIR spectroscopy were employed for the purpose of characterization of attachment of enzyme on the graphene. The enzyme kinetic studies were carried out for obtaining best catalytic performance and enhanced reusability. Optimum temperature remained unchanged, whereas optimum pH showed shift towards acidic range for immobilized enzyme. Increase in thermal stability of immobilized enzyme and non-toxic nature of functionalized graphene can be exploited for production of maltose in food and pharmaceutical industries.

  5. Immobilized low-level waste disposal options configuration study

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, D.E.

    1995-02-01

    This report compiles information that supports the eventual conceptual and definitive design of a disposal facility for immobilized low-level waste. The report includes the results of a joint Westinghouse/Fluor Daniel Inc. evaluation of trade-offs for glass manufacturing and product (waste form) disposal. Though recommendations for the preferred manufacturing and disposal option for low-level waste are outside the scope of this document, relative ranking as applied to facility complexity, safety, remote operation concepts and ease of retrieval are addressed.

  6. Laccase production by free and immobilized mycelia of Peniophora cinerea and Trametes versicolor: a comparative study.

    Science.gov (United States)

    Silvério, Sara C; Moreira, Sérgio; Milagres, Adriane M F; Macedo, Eugénia A; Teixeira, José A; Mussatto, Solange I

    2013-03-01

    The production of laccase by immobilized mycelia of Peniophora cinerea and Trametes versicolor was studied. In an initial stage, experimental assays were performed in Erlenmeyer flasks using free and immobilized mycelium, and the performance of the fungal strains to produce the enzyme was compared. Both fungi adhered into the support material (a synthetic fiber), growing not only on the surface but also in the interspaces of the fibers. Immobilization of P. cinerea provided a 35-fold increase in laccase production when compared to the production obtained by using free mycelium. On the other hand, immobilization of T. versicolor caused a decrease in laccase activity. A comparison between the strains revealed that immobilized P. cinerea (3,500 U/L) surpassed the enzyme production by free T. versicolor (800 U/L). When the conditions that gave the best laccase production to each fungus were employed in a stirred tank bioreactor, very low laccase production was observed for both the cases, suggesting that shear stress and mycelia damage caused by the agitation impellers negatively affected the enzyme production.

  7. Gamma radiation grafted polymers for immobilization of Brucella antigen in diagnostic test studies

    Science.gov (United States)

    Docters, E. H.; Smolko, E. E.; Suarez, C. E.

    The radiation grafting process has a wide field of industrial applications, and in the recent years the immobilization of biocomponents in grafted polymeric materials obtained by means of ionizing radiations is a new and important contribution to biotechnology. In the present work, gamma preirradiation grafting method was employed to produce acrylics hydrogels onto polyethylene (PE), polyvinyl chloride (PVC) and polystyrene (PS). Two monomers were used to graft the previously mentioned polymers: methacrylic acid (MAAc) and acrylamide (AAm), and several working conditions were considered as influencing the degree of grafting. All this grafted polymers were used to study the possibility of a subsequent immobilization of Brucella antigen (BAg) in diagnostic test studies (ELISA).

  8. Comparative study of 6-APA production by free and agar immobilized bacteria in nutrient broth culture.

    Science.gov (United States)

    Dolui, A K; Das, S

    2011-04-01

    In the present study different bacterial samples were isolated from soil of different places of Dibrugarh and screened for biotransformation ability to produce 6-Aminopenicillanic acid. Among ten isolated bacterial samples, three gram positive bacterial samples designated as AKDD-2, AKDD-4 and AKDD-6 showed the production of 6-APA from penicillin G. Assessment of production of 6-APA after incubation in penicillin G (2 mg/ml) by three different samples separately in free and agar immobilization state was done by HPLC analysis. Reusability of immobilized cells was found successful up to 14 days.

  9. STUDY ON IMMOBILIZED PORCINE PANCREATIC LIPASE CATALYZING TRANSESTERIFICATION BETWEEN METHYL—BUTYRATE AND 1—BUTANOL IN NONAQUEOUS SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    XieZhidong; LueXianyu; 等

    1996-01-01

    Transesterification between methyl-butyrate and 1-butanol in nonaqueous systems was catalyzed by porcine pancreatic lipase which was immobilized on cross-linked polystyrene.Organic solvents,substrate concentration,contents of water and other parameters which affect the immobilized enzyme activity were studied.Lipase immobilized on hydrophobic crosslinked polystyrene can reduce its diffusion limit in the reaction.It was found that the activity of immobilized lipase in organic systems was two times as high as that of free lipase.

  10. A Comparison Study of New TiO2/PEG Immobilized Techniques Under Normal and Visible Light Irradiations

    OpenAIRE

    Zaharudin R.; Ain S. K.; Bakar F.; Azami M. S.; Nawawi W. I.

    2016-01-01

    Novel photocatalysts of TiO2 and TiO2/PEG were immobilized using new technique which is double sided adhesive tape (DSAT) as a thin layer binder onto glass plate. The photocatalytic activity study of immobilized/TiO2 and immobilized/TiO2/PEG were carried out by irradiating of 36 mg L-1 MB dye in the presence of normal and visible light with rate of decolourization was estimated from aliquot concentration spectrophotometrically. The high photocatalytic activity from immobilized/TiO2/PEG was ob...

  11. A Study on RR4 Dye as a Sensitizer in Enhancing Photoactivity of Immobilized Photocatalysts

    Directory of Open Access Journals (Sweden)

    Bakar F.

    2016-01-01

    Full Text Available In this work, anionic RR4 dye was used to sensitize TiO2/PVA and TiO2/PEG immobilized system in enhancing photocatalytic degradation of cationic methylene blue (MB dye. 0.3g of TiO2 and polymer binder was coated onto a clean glass plate by using brush technique to develop optimum immobilize TiO2 system. A comparison study between immobilized TiO2/PVA (Im/TiO2/PVA and Immobilized TiO2/PEG (Im/TiO2/PEG system with and without RR4 sensitizer were carried out under 45 W fluorescent lamp and visible light irradiation. The photocatalytic degradation of MB was significantly enhanced for both RR4 dye sensitized Im/TiO2/PVA and Im/TiO2/PEG with 1st order rate constant was ca. 0.035 and 0.030 min-1 respectively under 45-W fluorescent lamp. Same observation as well under visible light irradiation whereby enhanced of those RR4 sensitized immobilized photocatalysts were recorded as compared with immobilized photocatalysts without RR4 as sensitizer. The photocatalytic enhancement under Im/TiO2/PVA/RR4 and Im/TiO2/PEG/RR4 are due to the ability of RR4 dye to become electron (e- donor for conduction band (CB of TiO2, thus making TiO2 CB riches with electron, eventually this e- is used to remove MB by producing hydroxyl radical.

  12. SCALE-UP STUDIES ON IMMOBILIZATION OF LACTOPEROXIDASE USING MILK WHEY FOR PRODUCING ANTIMICROBIAL AGENT

    Directory of Open Access Journals (Sweden)

    A.N. Al-Baarri

    2014-10-01

    Full Text Available Hypothiocyanite (OSCN–, produced by lactoperoxidase (LPO in the presence of SCN– and H2O2,inhibits the growth of bacteria. This inhibition is called by LPO system (LPOS. Our laboratory scalestudy in previous experiment showed that whey immobilized on SP-Sepharose Fast Flow (SP-FF couldproduce OSCN– continuously. Then, the purpose of this study is to scale up continuous production ofOSCN– using immobilized whey. Immobilized whey was generated by circulating various amounts ofwhey through SP-FF. To generate OSCN–, 10 ml of the substrate solution containing 0.5 mM SCN– and0.5 mM H2O2, was circulated through immobilized whey and followed by washing with pure water. Thenext cycle was done by circulating a fresh 10 ml of substrate solution at the same concentration. Theresult indicated that a stable immobilization efficiency of more than 90% was achieved in the SP-FFcirculated with 300 ml or less of whey per gram of SP-FF. When stored at 4˚C, immobilized wheyretained 80% LPO activity until 3 weeks storage. The reaction solution discharged from immobilizedwhey was observed to contain approximately 0.4 mM OSCN–. The experiment using 1.0 g ofimmobilized whey produced a stable 0.4 mM OSCN– production and antimicrobial activity for at least 6cycles. The increase in resin volume accompanied by the increase in whey volume resulted the extensionof a stable OSCN– production. The experiment using recycled SP-FF did not affect to the stability ofOSCN– production and antimicrobial activity. These results may open the way for the large-scaleproduction of OSCN−.

  13. Mechanistic study for immobilization of cysteine-labeled oligopeptides on UV-activated surfaces.

    Science.gov (United States)

    Ong, Lian Hao; Ding, Xiaokang; Yang, Kun-Lin

    2014-10-01

    In this study, we report immobilization of cysteine-labeled oligopeptides on UV activated surfaces decorated with N,N-dimethyl-n-octadecyl-3-aminopropyltrimethoxysilyl chloride (DMOAP). Our result shows that cysteine group, regardless of its position in the oligopeptide, is essential for successful immobilization of oligopeptide on the UV-activated surface. A possible reaction mechanism is nucleophilic addition of thiolates to surface aldehyde groups generated during UV activation. By using this technique, we are able to incorporate anchoring points into oligopeptides through cysteine residues. Furthermore, immobilized oligopeptides on the UV-activated surface is very stable even under harsh washing conditions. Finally, we show that an HPQ-containing oligopeptide can be immobilized on the UV-activated surface, but the final surface density and its ability to bind streptavidin are affected by the position of cysteine and HPQ. An oligopeptide with a cysteine at the N-terminus and a HPQ motif at the C-terminus gives the highest binding signal in the streptavidin-binding assay. This result is potentially useful for the development of functional oligopeptide microarrays for detecting target protein molecules.

  14. Immobilization study of biosorption of heavy metal ions onto activated sludge

    Institute of Scientific and Technical Information of China (English)

    WU Hai-suo; ZHANG Ai-qiang; WANG Lian-sheng

    2004-01-01

    Activated sludge was immobilized into Ca-alginate beads via entrapment, and biosorption of three heavy metal ions, copper(Ⅱ), zinc(Ⅱ), and chromimum(Ⅱ), from aqueous solution in the concentration range of 10-100 mg/L was studied by using both entrapped activated sludge and inactivated free biomass at pH≤ 5. A biphasic metal adsorption pattern was observed in all immobilized biomass experiments. The biosorption of metal ions by the biosorbents increased with the initial concentration increased in the medium. The adsorption rate of immobilized pretreated activated sludge(PAS) was much lower than that of free PAS due to the increase in mass transfer resistance resulting from the polymeric matrix. Biosorption equilibrium of beads was established in about 20 h and the adsorbed heavy metal ions did not change further with time. No significant effect of temperature was observed in the test for free biomass while immobilized PAS appeared to be strong temperature dependent in the test range of 10 and 40℃.Besides, the content of activated sludge in the calcium alginate bead has an influence on the uptake of heavy metals. The sorption equilibrium was well modeled by Langmuir isotherm, implying monomolecular adsorption mechanism. Carboxyl group in cell wall played an important role in surface adsorption of heavy metal ions on PAS.

  15. [Study on immobilized cells for producing alpha-amylase by using polyving alcohol as the carrier(II): The effect of fermentating conditions on the ability producing alpha-amylase of the cells immobilized with polyving alcohol as the corrier and continuous fermentation of the immobilized cells in CSTR].

    Science.gov (United States)

    Liu, Z; Wang, J; Li, Z

    1998-03-01

    The effects of fermentating conditions on the ability of immobilized cells with PVA as carrier for producing alpha-amylase were studied. The continuous fermentation with the immobilized cells were tested in continuous flow stirred tank reactor (CSTR). The results showed that the adaptability of the immobilized Bacillus substilis to pH increased after immobilization. In CSTR, the immobilized cells can be fermentated continuously for 360 hrs and the activity of alpha-amylase can be kept on the level of about 170 u/ml.

  16. Electrochemical and in situ spectroelectrochemical studies of gold nanoparticles immobilized Nafion matrix modified electrode

    Indian Academy of Sciences (India)

    T Selvaraju; S Sivagami; S Thangavel; R Ramaraj

    2008-06-01

    Electrochemical and in situ spectroelectrochemical behaviours of phenosafranine (PS+) were studied at the gold nanoparticles (AuNps) immobilized Nafion (Nf) film coated glassy carbon (GC) and indium tin oxide (ITO) electrodes. Cyclic voltammetric studies showed that the PS+ molecules strongly interact with the AuNps immobilized in the Nf matrix through the electrostatic interaction. The presence of AuNps in the Nf film improved the electrochemical characteristics of the incorporated dye molecules. The emission spectra of Nf–AuNps–PS+ films showed that the incorporated PS+ was quenched by AuNps and it could be explained based on the electronic interaction between the AuNps and PS+ molecules. The in situ spectroelectrochemical study showed an improved electrochemical characteristic of the incorporated PS+ molecules at the ITO/Nf–AuNps electrode when compared to the ITO/Nf electrode.

  17. Comparison between Free and Immobilized Ion Effects on Hydrophobic Interactions: A Molecular Dynamics Study

    CERN Document Server

    Huang, Kai; Ma, C Derek; Abbott, Nicholas L; Szlufarska, Izabela

    2016-01-01

    Fundamental studies of the effect of specific ions on hydrophobic interactions are driven by the need to understand phenomena such as hydrophobically driven self-assembly or protein folding. Using beta-peptide-inspired nano-rods, we investigate the effects of both free ions (dissolved salts) and proximally immobilized ions on hydrophobic interactions. We find that the free ion effect is correlated with the water density fluctuation near a non-polar molecular surface, showing that such fluctuation can be an indicator of hydrophobic interactions in the case of solution additives. In the case of immobilized ion, our results demonstrate that hydrophobic interactions can be switched on and off by choosing different spatial arrangements of proximal ions on a nano-rod. For globally amphiphilic nano-rods, we find that the magnitude of the interaction can be further tuned using proximal ions with varying ionic sizes. In general, univalent proximal anions are found to weaken hydrophobic interactions. This is in contras...

  18. Covalent Immobilization of Biotin on Magnetic Nanoparticles: Synthesis, Characterization, and Cytotoxicity Studies.

    Science.gov (United States)

    Islam, Md Rafiqul; Bach, Long Giang; Vo, Thanh-Sang; Lim, Kwon Taek

    2015-01-01

    A simple protocol for covalent immobilization of biotin onto the surface of Fe3O4 magnetic nanoparticles (MNPs) for improving the biocompatibility of original MNPs has been realized. MNPs were first prepared by co-precipitation method which was subsequently anchored with functionalized biotin. The as-synthesized MNPs were observed to be monocrystalline as evidenced from XRD and TEM images. The covalent grafting of biotin to MNPs was confirmed by FT-IR. The XPS analysis suggested the successful preparation of Biotin-f-MNPs. The as-synthesized Biotin-f-MNPs were found to be superparamagnetic character as recorded by SQUID. Cell viability studies revealed that the biocompatibility of MNPs was improved upon Biotin immobilization.

  19. Application of ring-opening metathesis polymerization in study of polymer molecular weight-mediated catalytic properties of immobilized lipase

    Institute of Scientific and Technical Information of China (English)

    DU Chuang; ZHANG Guo; WANG Zhi; LI Lei; TANG Jun; WANG Lei

    2009-01-01

    Recently, significant efforts have been devoted into the study of the effect of hydrophobic supports on the catalytic properties of immobilized lipases. It seems that immobilization lipases on hydrophobic supports is a simple and efficient method to improve the catalytic activity of lipases. In this study, the hydrophobic poly(N-propyl-norbornene-exo-2,3-dicarboximide)s with well-controlled molecular weight were synthesized by the living ring-opening metathesis polymerization, and the lipases from Pseudo-monas sp. were then immobilized on these hydrophobic polymer supports through the physical ad-sorption. The immobilized lipases exhibited higher activity and enantioselectivity for the transesterifi-cation of 2-octanol than those of free lipases. Furthermore, we investigated the polymer molecular weight-mediated catalytic properties of immobilized lipases. It was found that the catalytic activity and E value of the immobilized lipases increased with the increase of the polymer molecular weight. At the polymeric molecular weight of about 40kDa, the highest E value (58 at 54.2% of conversion, enanti-omeric excess = 99%) was reached. After the molecular weight of polymers getting higher than 40 kDa, catalytic activity end E value of the immobilized lipase decreased.

  20. Preparation of enzyme nanoparticles and studying the catalytic activity of the immobilized nanoparticles on polyethylene films.

    Science.gov (United States)

    Meridor, David; Gedanken, Aharon

    2013-01-01

    Using high-intensity ultrasound, in situ generated α-amylase nanoparticles (NPs) were immobilized on polyethylene (PE) films. The α-amylase NP-coated PE films have been characterized by E-SEM, FTIR, DLS, XPS and RBS. The PE was reacted with HNO(3) and NPs of the α-amylase were also deposited on the activated PE. The PE impregnated with α-amylase (4 μg per 1mg PE) was used for hydrolyzing soluble potato starch to maltose. The immobilization improved the catalytic activity of α-amylase at all the reaction conditions studied. The kinetic parameters, K(m) (5 and 4 g L(-1) for the regular and activated PE, respectively) and V(max) (5 × 10(-7) mol ml(-1) min(-1), almost the same numbers were obtained for the regular and activated PEs) for the immobilized amylase were found to slightly favor the respective values obtained for the free enzyme (K(m) = 6.6 g L(-1), V(max) = 3.7 × 10(-7) mol ml(-1) min(-1)). The enzyme remained bound to PE even after soaking the PE in a starch solution for 72 h and was still found to be weakly active. Copyright © 2012 Elsevier B.V. All rights reserved.

  1. THERMAL ACTIVATION OF IMMOBILIZED PAPAIN

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    Papain (Papainase, EC 3.4.22.2) was immobilized on porous silica beads by cross linking with glutaraldehyde. The thermal activation of this immobilized papain in aqueous system was found at a temperature range from 50 to 90℃. The higher the temperature, the more active the immobilized papain will possess. At the same time,the durability of the immobilized papain on heating was greatly improved. The effect of additives and salts on the activity of the immobilized papain were also studied. The results showed that the additives and some of the salts studied could markedly enhance the activity of the immobilized papain at elevated temperature.

  2. Immobilized lysozyme for the continuous lysis of lactic bacteria in wine: Bench-scale fluidized-bed reactor study.

    Science.gov (United States)

    Cappannella, Elena; Benucci, Ilaria; Lombardelli, Claudio; Liburdi, Katia; Bavaro, Teodora; Esti, Marco

    2016-11-01

    Lysozyme from hen egg white (HEWL) was covalently immobilized on spherical supports based on microbial chitosan in order to develop a system for the continuous, efficient and food-grade enzymatic lysis of lactic bacteria (Oenococcus oeni) in white and red wine. The objective is to limit the sulfur dioxide dosage required to control malolactic fermentation, via a cell concentration typical during this process. The immobilization procedure was optimized in batch mode, evaluating the enzyme loading, the specific activity, and the kinetic parameters in model wine. Subsequently, a bench-scale fluidized-bed reactor was developed, applying the optimized process conditions. HEWL appeared more effective in the immobilized form than in the free one, when the reactor was applied in real white and red wine. This preliminary study suggests that covalent immobilization renders the enzyme less sensitive to the inhibitory effect of wine flavans. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. [Study on CTP production from CMP by beer yeast cell immobilized in PVA].

    Science.gov (United States)

    Yang, Hong-Yi; Qian, Shi-Jun; Li, Gao-Wo

    2007-03-01

    With PVA as the carrier, the frozen beer yeast cells were immobilized for production of CTP from CMP. we explored the optimal condition of the immobilization from the aspects of the type, concentration of the PVA, and the immobilizing methods of cells In all 8 continuous batch of fermentation under the reactional condition of the immobilized cells, the conversion rate of CTP were maintained about 85% - 95%. Moreever, the storage stability of immobilized cells were investigated, and the products was also isolated and identifided by HPLC.

  4. In vitro metabolic study of Rhizoma coptidis extract using liver microsomes immobilized on magnetic nanoparticles.

    Science.gov (United States)

    Xue, Ying; Xiong, Jing; Shi, Hai-Li; Liu, Yi-Ming; Qing, Lin-Sen; Liao, Xun

    2013-11-01

    Although metabolic study of individual active compounds isolated from herbal plants has been intensive, it cannot truly reflect the fate of herbs because the herbal extracts in use have many constituents. To address this problem, whole extracts of herbs should be investigated. Microsomes have been heavily used in the in vitro metabolic study of drugs, and various materials have been used to immobilize microsomes to develop highly effective and reusable bioreactors in this field. In this work, rat liver microsomes were immobilized on magnetic nanoparticles (LMMNPs) to develop a highly active and recoverable nanoparticle bioreactor. Using this bioreactor, we investigated the in vitro metabolism of Rhizoma coptidis extract. Incubation of berberine, a major active ingredient of R. coptidis, with LMMNPs for 20 min produced two metabolites, i.e., demethyleneberberine and thalifendine, at high levels. From a comparison of the time courses of thalifendine formation obtained by ultraperformance liquid chromatography-mass spectrometry analysis, it was found that LMMNPs had a higher biological activity than free liver microsomes in metabolizing berberine. Further, the activity of LMMNPs remained almost unchanged after six consecutive uses in the incubation tests. Metabolism of R. coptidis extracts by LMMNPs was studied. The same two metabolites of berberine, i.e., demethyleneberberine and thalifendine, were detected. After a thorough study seeking support for this observation, it was found that demethyleneberberine was the common metabolite of five protoberberine-type alkaloids present in R. coptidis extract, including palmatine, jatrorrhizine, columbanine, epiberberine, and berberine.

  5. Modification of silicon nitride surfaces with GOPES and APTES for antibody immobilization: computational and experimental studies

    Science.gov (United States)

    Dien To, Thien; Nguyen, Anh Tuan; Nhat Thanh Phan, Khoa; Thu Thi Truong, An; Doan, Tin Chanh Duc; Mau Dang, Chien

    2015-12-01

    Chemical modification of silicon nitride (SiN) surfaces by silanization has been widely studied especially with 3-(aminopropyl)triethoxysilane (APTES) and 3-(glycidyloxypropyl) dimethylethoxysilane (GOPES). However few reports performed the experimental and computational studies together. In this study, surface modification of SiN surfaces with GOPES and APTES covalently bound with glutaraldehyde (GTA) was investigated for antibody immobilization. The monoclonal anti-cytokeratin-FITC (MACF) antibody was immobilized on the modified SiN surfaces. The modified surfaces were characterized by water contact angle measurements, atomic force microscopy and fluorescence microscopy. The FITC-fluorescent label indicated the existence of MACF antibody on the SiN surfaces and the efficiency of the silanization reaction. Absorption of APTES and GOPES on the oxidized SiN surfaces was computationally modeled and calculated by Materials Studio software. The computational and experimental results showed that modification of the SiN surfaces with APTES and GTA was more effective than the modification with GOPES.

  6. Photocatalytic Study of New Immobilized TiO2 Technique Towards Degradation of Reactive Red 4 Dye

    Directory of Open Access Journals (Sweden)

    Ain S. K.

    2016-01-01

    Full Text Available The study on TiO2 for wastewater remediation has gained interest among researchers. However, the application of this photocatalyst is limited due to non-recyclability of conventional TiO2. Thus, immobilization technique has been developed to solve this issue. Hence, a comparison study between two types of immobilized photocatalysts namely titanium dioxide (TiO2 and TiO2 mixed with polyvinyl alcohol (PVA has been conducted in this work to observe the significant effect of PVA polymer in photocatalysis reaction of reactive red 4 (RR4 dye. Double sided adhesive tape (DSAT was used as thin layer binder in this immobilization system. The result shows that the photocatalytic performance of TiO2-PVA/DSAT was higher than that of TiO2/DSAT under both normal UV and visible light irradiations due to the conjugated unsaturated polymer from PVA serve as electron donor for TiO2 thus increase the photocatalysis process. Besides, TiO2-PVA/DSAT was also found to possess much better adhesion strength to the support material compared to TiO2/DSAT. Based on the findings, this TiO2 immobilization system is expected to be beneficial in the industrial wastewater treatment. Thus, further study to improve the photocatalytic activity of this immobilized TiO2 will be in our future work.

  7. Immobilization of flavan-3-ols onto sensor chips to study their interactions with proteins and pectins by SPR

    Energy Technology Data Exchange (ETDEWEB)

    Watrelot, Aude A., E-mail: aude.watrelot@avignon.inra.fr [INRA, UMR408 Sécurité et Qualité des Produits d’Origine Végétale, Domaine St Paul, Site Agroparc, 84914 Avignon (France); Université d’Avignon, UMR408 Sécurité et Qualité des Produits d' Origine Végétale, F-84000 Avignon (France); Tran, Dong Tien [Université de Bordeaux, Institut des Sciences Moléculaires (UMR-CNRS 5255), 351 cours de la Libération, 33405 Talence (France); Institut Européen de Chimie et Biologie (IECB), 2 rue Robert Escarpit, 33607 Pessac (France); Buffeteau, Thierry [Université de Bordeaux, Institut des Sciences Moléculaires (UMR-CNRS 5255), 351 cours de la Libération, 33405 Talence (France); Deffieux, Denis [Université de Bordeaux, Institut des Sciences Moléculaires (UMR-CNRS 5255), 351 cours de la Libération, 33405 Talence (France); Institut Européen de Chimie et Biologie (IECB), 2 rue Robert Escarpit, 33607 Pessac (France); and others

    2016-05-15

    Highlights: • Flavanol-macromolecule interactions were determined using SPR. • Flavanols were chemically modified with a linker bearing a thiol group. • Flavanols were immobilized onto a carboxymethyl dextran surface. • Citrus pectin interacted more with flavanols than apple pectin. • Epicatechin interacted more with BSA than flavanol oligomer. - Abstract: Interactions between plant polyphenols and biomacromolecules such as proteins and pectins have been studied by several methods in solution (e.g. isothermal titration calorimetry, dynamic light scattering, nuclear magnetic resonance and spectrophotometry). Herein, these interactions were investigated in real time by Surface Plasmon Resonance (SPR) analysis after immobilization of flavan-3-ols onto a sensor chip surface. (−)-epicatechin, (+)-catechin and flavan-3-ol oligomers with an average degree of polymerization of 2 and 8 were chemically modified using N-(2-(tritylthio)ethyl)propiolamide in order to introduce a spacer unit onto the catecholic B ring. Modified flavan-3-ols were then immobilized onto a carboxymethylated dextran surface (CM5). Immobilization was validated and further verified by evaluating flavan-3-ol interaction with bovine serum albumin (BSA), poly-L-proline or commercial pectins. BSA was found to have a stronger association with monomeric flavan-3-ols than oligomers. SPR analysis of selected flavan-3-ols immobilized onto CM5 sensor chips showed a stronger association for citrus pectins than apple pectins, regardless of flavan-3-ol degree of polymerization.

  8. Immobilized Kluyveromyces marxianus cells in carboxymethyl cellulose for production of ethanol from cheese whey: experimental and kinetic studies.

    Science.gov (United States)

    Roohina, Fatemeh; Mohammadi, Maedeh; Najafpour, Ghasem D

    2016-09-01

    Cheese whey fermentation to ethanol using immobilized Kluyveromyces marxianus cells was investigated in batch and continuous operation. In batch fermentation, the yeast cells were immobilized in carboxymethyl cellulose (CMC) polymer and also synthesized graft copolymer of CMC with N-vinyl-2-pyrrolidone, denoted as CMC-g-PVP, and the efficiency of the two developed cell entrapped beads for lactose fermentation to ethanol was examined. The yeast cells immobilized in CMC-g-PVP performed slightly better than CMC with ethanol production yields of 0.52 and 0.49 g ethanol/g lactose, respectively. The effect of supplementation of cheese whey with lactose (42, 70, 100 and 150 g/l) on fermentative performance of K. marxianus immobilized in CMC beads was considered and the results were used for kinetic studies. The first order reaction model was suitable to describe the kinetics of substrate utilization and modified Gompertz model was quite successful to predict the ethanol production. For continuous ethanol fermentation, a packed-bed immobilized cell reactor (ICR) was operated at several hydraulic retention times; HRTs of 11, 15 and 30 h. At the HRT of 30 h, the ethanol production yield using CMC beads was 0.49 g/g which implies that 91.07 % of the theoretical yield was achieved.

  9. A comparative study for lipase immobilization onto alginate based composite electrospun nanofibers with effective and enhanced stability.

    Science.gov (United States)

    İspirli Doğaç, Yasemin; Deveci, İlyas; Mercimek, Bedrettin; Teke, Mustafa

    2017-03-01

    In this study, lipase was successfully immobilized on polyvinyl alcohol/alginate and polyethylene oxide/alginate nanofibers that were prepared by electrospinning. Results showed that nanofibers (especially polyvinyl alcohol/alginate) enhanced the stability properties of lipase. When the free lipase lost its all activity after 40-60min at high temperatures, both lipase immobilized nanofibers kept almost 65-70% activity at the same time. The lipase immobilized poly vinyl alcohol/alginate and polyethylene oxide/alginate nanofibers protected approximately all of their activities until pH 9. Lipase immobilized polyvinyl alcohol/alginate and polyethylene oxide/alginate nanofibers maintained 60% of their activities after 14 and 7 reuses, respectively. The morphology of nanofibers was characterized by Scanning Electron Microscope, Fourier Transform Infrared Spectroscopy and Thermal Gravimetric Analyzer. As a result, this nanofiber production method, electrospinning, is simple, versatile and economical for preparing appropriate carrier to immobilize the enzymes. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Instrumentation for studying binder burnout in an immobilized plutonium ceramic wasteform

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, M; Pugh, D; Herman, C

    2000-04-21

    The Plutonium Immobilization Program produces a ceramic wasteform that utilizes organic binders. Several techniques and instruments were developed to study binder burnout on full size ceramic samples in a production environment. This approach provides a method for developing process parameters on production scale to optimize throughput, product quality, offgas behavior, and plant emissions. These instruments allow for offgas analysis, large-scale TGA, product quality observation, and thermal modeling. Using these tools, results from lab-scale techniques such as laser dilametry studies and traditional TGA/DTA analysis can be integrated. Often, the sintering step of a ceramification process is the limiting process step that controls the production throughput. Therefore, optimization of sintering behavior is important for overall process success. Furthermore, the capabilities of this instrumentation allows better understanding of plant emissions of key gases: volatile organic compounds (VOCs), volatile inorganics including some halide compounds, NO{sub x}, SO{sub x}, carbon dioxide, and carbon monoxide.

  11. Invertase immobilization by adsorption on polymer microspheres studied by radioiodination technique

    Energy Technology Data Exchange (ETDEWEB)

    Queiroz, Alvaro A.A. de [Universidade Federal de Itajuba, MG (Brazil). Inst. de Ciencias Exatas. Dept. de Fisica e Quimica]. E-mail: alencar@unifei.edu.br; Pontin, Luiz F. [Universidade Federal de Itajuba, MG (Brazil). Inst. de Ciencias Exatas. Dept. de Matematica e Computacao]. E-mail: pontin@unifei.edu.br; Higa, Olga Z.; Ribela, Maria Tereza C.P. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Lab. de Biologia Molecular]. E-mail: ozahiga@ipen.br; Tomotani, Ester J.; Vitolo, Michele [Sao Paulo Univ., SP (Brazil). Faculdade de Ciencias Farmaceuticas. Dept. de Tecnologia Bioquimico-Farmaceutica]. E-mail: michenzi@usp.br

    2005-07-01

    In this paper, we report the study of the diffusion behavior of invertase onto polystyrene-divinylbenzene (PS-DVB) microspheres. To detect the surface concentration of protein adsorbed on the microspheres, the chloramine-T method was used to label invertase and has been applied to the study of protein sorption properties on the microspheres. The sorption isotherms and the diffusion coefficient (D{sub f}) were computed from experimental results and the concentration of bound invertase was determined in terms of the Fick's law. The Hill equation was applied to the data and the binding capacity of the microspheres were estimated. The results of adsorption show that the radiolabelling invertase method are efficacious at the protein surface concentration detection and can be used to investigate the enzyme immobilization by sorption properties of polymer microspheres. (author)

  12. Spectroscopic study of 3-Hydroxyflavone - protein interaction in lipidic bi-layers immobilized on silver nanoparticles

    Science.gov (United States)

    Voicescu, Mariana; Ionescu, Sorana; Nistor, Cristina L.

    2017-01-01

    The interaction of 3-Hydroxyflavone with serum proteins (BSA and HSA) in lecithin lipidic bi-layers (PC) immobilized on silver nanoparticles (SNPs), was studied by fluorescence and Raman spectroscopy. BSA secondary structure was quantified with a deconvolution algorithm, showing a decrease in α-helix structure when lipids were added to the solution. The effect of temperature on the rate of the excited-state intra-molecular proton transfer and on the dual fluorescence emission of 3-HF in the HSA/PC/SNPs systems was discussed. Evaluation of the antioxidant activity of 3-HF in HSA/PC/SNPs systems was also studied. The antioxidant activity of 3-HF decreased in the presence of SNPs. The results are discussed with relevance to the secondary structure of proteins and of the 3-HF based nano-systems to a topical formulation useful in the oxidative stress process.

  13. Gold nanoworms immobilized graphene oxide polymer brush nanohybrid for catalytic degradation studies of organic dyes

    Science.gov (United States)

    Mogha, Navin Kumar; Gosain, Saransh; Masram, Dhanraj T.

    2017-02-01

    In the present work, we report gold nanoparticles (AuNPs) on poly (dimethylaminoethyl methacrylate) (PDMAEMA) brushes immobilized reduced graphene oxide (Au/PDMAEMA/RGO) as catalyst for degradation kinetic studies of Rhodamine B (RB), Methyl Orange (MO) and Eosine Y (EY) dyes, having an excellent catalytic activity, as evident by the apparent rate constant (kapp), which is found to be 21.8, 26.2, and 8.7 (×10-3 s-1), for RB, MO and EY respectively. Au/PDMAEMA/RGO catalyst is easy to use, highly efficient, recyclable, which make it suitable for applications in waste water management. Foremost, synthesis of PDMAEMA brushes on graphene oxide is accomplished by Atom transfer radical polymerization method (ATRP), whereas AuNPs are synthesized by simple chemical reduction method.

  14. Biosorption of Cu(II) by immobilized microalgae using silica: kinetic, equilibrium, and thermodynamic study.

    Science.gov (United States)

    Lee, Hongkyun; Shim, Eunjung; Yun, Hyun-Shik; Park, Young-Tae; Kim, Dohyeong; Ji, Min-Kyu; Kim, Chi-Kyung; Shin, Won-Sik; Choi, Jaeyoung

    2016-01-01

    Immobilized microalgae using silica (IMS) from Micractinium reisseri KGE33 was synthesized through a sol-gel reaction. Green algal waste biomass, the residue of M. reisseri KGE33 after oil extraction, was used as the biomaterial. The adsorption of Cu(II) on IMS was tested in batch experiments with varying algal doses, pH, contact times, initial Cu(II) concentrations, and temperatures. Three types of IMSs (IMS 14, 70, and 100) were synthesized according to different algal doses. The removal efficiency of Cu(II) in the aqueous phase was in the following order: IMS 14 (77.0%)  IMS 70 (1.548 mg g(-1)) > IMS 14 (1.282 mg g(-1)). The pseudo-second-order equation fitted the kinetics data well, and the value of the second-order rate constant increased with increasing algal dose. Gibbs free energies (ΔG°) were negative within the temperature range studied, which indicates that the adsorption process was spontaneous. The negative value of enthalpy (ΔH°) again indicates the exothermic nature of the adsorption process. In addition, SEM-energy-dispersive X-ray spectroscopy (EDS), Fourier transform infrared (FT-IR), and X-ray photoelectron spectroscopy (XPS) analyses of the IMS surface reveal that the algal biomass on IMS is the main site for Cu(II) binding. This study shows that immobilized microalgae using silica, a synthesized biosorbent, can be used as a cost-effective sorbent for Cu(II) removal from the aqueous phase.

  15. Useful oriented immobilization of antibodies on chimeric magnetic particles: direct correlation of biomacromolecule orientation with biological activity by AFM studies.

    Science.gov (United States)

    Marciello, Marzia; Filice, Marco; Olea, David; Velez, Marisela; Guisan, José M; Mateo, Cesar

    2014-12-16

    The preparation and performance of a suitable chimeric biosensor based on antibodies (Abs) immobilized on lipase-coated magnetic particles by means of a standing orienting strategy are presented. This novel system is based on hydrophobic magnetic particles coated with modified lipase molecules able to orient and further immobilize different Abs in a covalent way without any previous site-selective chemical modification of biomacromolecules. Different key parameters attending the process were studied and optimized. The optimal preparation was performed using a controlled loading (1 nmol Ab g(-1) chimeric support) at pH 9 and a short reaction time to recover a biological activity of about 80%. AFM microscopy was used to study and confirm the Abs-oriented immobilization on lipase-coated magnetic particles and the final achievement of a highly active and recyclable chimeric immune sensor. This direct technique was demonstrated to be a powerful alternative to the indirect immunoactivity assay methods for the study of biomacromolecule-oriented immobilizations.

  16. A noble technique a using force-sensing resistor for immobilization-device quality assurance: A feasibility study

    Science.gov (United States)

    Cho, Min-Seok; Kim, Tae-Ho; Kang, Seong-Hee; Kim, Dong-Su; Kim, Kyeong-Hyeon; Shin, Dong-Seok; Noh, Yu-Yun; Koo, Hyun-Jae; Cheon, Geum Seong; Suh, Tae Suk; Kim, Siyong

    2016-03-01

    Many studies have reported that a patient can move even when an immobilization device is used. Researchers have developed an immobilization-device quality-assurance (QA) system that evaluates the validity of immobilization devices. The QA system consists of force-sensing-resistor (FSR) sensor units, an electric circuit, a signal conditioning device, and a control personal computer (PC) with in-house software. The QA system is designed to measure the force between an immobilization device and a patient's skin by using the FSR sensor unit. This preliminary study aimed to evaluate the feasibility of using the QA system in radiation-exposure situations. When the FSR sensor unit was irradiated with a computed tomography (CT) beam and a treatment beam from a linear accelerator (LINAC), the stability of the output signal, the image artifact on the CT image, and changing the variation on the patient's dose were tested. The results of this study demonstrate that this system is promising in that it performed within the error range (signal variation on CT beam < 0.30 kPa, root-mean-square error (RMSE) of the two CT images according to presence or absence of the FSR sensor unit < 15 HU, signal variation on the treatment beam < 0.15 kPa, and dose difference between the presence and the absence of the FSR sensor unit < 0.02%). Based on the obtained results, we will volunteer tests to investigate the clinical feasibility of the QA system.

  17. Plutonium Immobilization Project Binder Burnout and Sintering Studies (Milestone 6.6a)

    Energy Technology Data Exchange (ETDEWEB)

    Chandler, G.

    1999-10-28

    The Plutonium Immobilization Team has developed an integrated test program to understand and optimize the controlling variables for the sintering step of the plutonium immobilization process. Sintering is the key process step that controls the product minerology. It is expected that the sintering will be the limiting process step that controls the throughput of the production line. The goal of the current sintering test program is to better understand factors that affect the sintering process.

  18. [Study of the interaction of main potato glycoalkaloids in inhibition of immobilized butyryl cholinesterase].

    Science.gov (United States)

    Arkhypova, V M; Dziadevych, S V; Jaffrezic-Renault, N; Martelet, C; Soldatkin, O P

    2006-01-01

    The interaction of main potato glycoalkaloids alpha-solanine and alpha-chaconine in inhibition of horse serum butyryl cholinesterases immobilized on the pH-sensitive field-effect transistors has been investigated. The method of isobol diagram of Loewe and Muishnek has been used for interpretation of results. It has been shown the alpha-chaconine inhibits the immobilized bytyryl cholinesterases more strongly than alpha-solanine, and their mixture has the addition effect.

  19. A study on the performance of hyaluronic acid immobilized chitosan film

    Energy Technology Data Exchange (ETDEWEB)

    Wang Yingjun; Guo Li; Ren Li; Yin Shiheng [Biomaterial Research Institute, College of Material Science and Engineering, South China University of Technology, Guangzhou, 510640 (China); Ge Jian; Gao Qianying [State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, 510060 (China); Luxbacher, Thomas; Luo Shijing, E-mail: imwangyj@scut.edu.c, E-mail: psliren@scut.edu.c [Anton Paar GmbH, Anton-Paar-Strasse 20, A-8054 Graz (Austria)

    2009-06-15

    In order to improve hydrophilicity and biocompatibility of chitosan, hyaluronic acid was immobilized onto the surface of chitosan film. The structure of films was characterized by Fourier transformed infrared spectroscopy with attenuated total reflectance (ATR-FTIR), x-ray photoelectron spectroscopy (XPS) and zeta potential. Results confirmed that hyaluronic acid was successfully immobilized on chitosan film. Transparency, water absorption percentage and contact angle of films were characterized. Results showed that there was no significant variation in transparency (p < 0.05) before and after immobilization, the maximum was up to 99% which was enough for corneal regeneration in clinical applications. After the immobilization, the time-dependent contact angle declined sharply (from 91.8 deg. to 67.7 deg. at 100 s). The hydrophilicity was significantly improved. The methylthiazol tetrazolium (MTT) (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay was used to assess cell viability and proliferation. Results showed that human cornea epithelial cells (HCEC) grew better on hyaluronic acid immobilized chitosan films than on chitosan films. The hyaluronic acid immobilized chitosan film could be a promising candidate material for corneal regeneration.

  20. Immobilization of Cd in landfill-leachate-contaminated soil with cow manure compost as soil conditioners: A laboratory study.

    Science.gov (United States)

    Liao, Zhuwei; Wang, Jia; Wan, Rui; Xi, Shuang; Chen, Zhuqi; Chen, Zhulei; Yu, Yingjian; Long, Sijie; Wang, Huabin

    2016-12-01

    Introducing cow manure compost as an amendment in landfill-leachate-contaminated soils is proved to be an effective technique for the immobilization of Cd in this study. Landfill-leachate-contaminated soil was collected from an unlined landfill in China and amended with a different blending quantity of cow manure compost (0, 12, 24, 36, and 48 g per 200 g soil), which was made by mixing cow manure and chaff at a ratio of 1/1 and maturing for 6 months. pH values of five different blending quantity mixtures increased by 0.2-0.4, and the organic matter levels increased by 2.5-7%, during a remediation period of 5 weeks. Four fractions of Cd named exchangeable Cd, reducible Cd, oxidizable Cd, and residual Cd in soil were respectively analyzed by a sequential extraction procedure. Introducing the cow manure compost application resulted in more than 40% lower exchangeable Cd but a higher concentration of oxidizable Cd in soils, and mass balance results showed nearly no Cd absorption by applied material, indicating that transformation of exchangeable Cd into oxidization forms was the main mechanism of Cd immobilization when cow manure compost was used as an amendment. The Pearson correlation showed that increasing of pH values significantly improved the efficiency of Cd immobilization, with a correlation coefficiency of 0.940 (p compost, and findings of this work can be integrated to guide the application. Addition of cow manure compost (CMC) was effective in reducing exchangeable Cd in landfill-leachate-contaminated soils (LLCS). The immobilization effect of Cd was mainly assigned to the redistribution of labile soil Cd. Organic matter (OM) and pH value increased with CMC application. The pH values were more sensitive to Cd immobilization efficiency. It was proved that CMC can be safely and effectively used for the restoration of LLCS.

  1. IMMOBILIZATION OF PAPAIN ON CHITOSAN

    OpenAIRE

    Cahyaningrum, Sari Edi; Narsito, Narsito; Santoso, Sri Juari; Agustini, Rudiana

    2010-01-01

    In this study, papain was immobilized on chitosan with Mg(II) cosslinked agent. Studies on free and immobilized papain systems for determination of optimum pH, optimum temperatur, thermal stability and reusability were carried out. The results showed that free papain had optimum pH 6.5 and optimum temperature 55 °C while the immobile papain hadoptimum pH 8 and optimum temperature 80 °C. The thermal stability of the immobilized papain, relative to that of the free papain, was markedly increase...

  2. Study on interactions of human IgG with immobilized anti-IgG or recombinant Staphylococcal protein A using surface plasmon resonance spectrometry

    Directory of Open Access Journals (Sweden)

    Bakhmachuk A. O.

    2016-02-01

    Full Text Available Aim. Comparison of the IgG-binding activity of recombinant Staphylococcal protein A with introduced C-terminal cysteine residue (SPA-Cys or goat anti-human IgG antibodies (anti-IgG after their immobilization on a gold sensor surface of surface plasmon resonance (SPR spectrometer. Methods. SPA-Cys or anti-IgG were immobilized on a gold sensor surface to form two variants of a bioselective element of the immunosensor. SPR spectrometry was used for the detection of IgG-binding activity of the immobilized proteins. Results.The SPR sensor response to the immobilization of anti-IgG was more than two times higher than that at the immobilization of SPA-Cys. However, there is almost the double advantage for SPA-Cys in the number of immobilized molecules. Moreover, the bioselective element of the immunosensor based on SPA-Cys showed a much better capability of binding Ig than bioselective element based on anti-IgG. Conclusions.The study on the immobilization of SPA-Cys or anti-IgG on the sensor surface of SPR spectrometer, and the interactions of immobilized proteins with human IgG demonstrated obvious advantages of SPA-Cys.

  3. A comparative study of enzyme immobilization strategies for multi-walled carbon nanotube glucose biosensors

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Jin; Jaroch, David; Rickus, Jenna L; Marshall Porterfield, D [Weldon School of Biomedical Engineering, Purdue University (United States); Claussen, Jonathan C; Ul Haque, Aeraj; Diggs, Alfred R [Physiological Sensing Facility, Bindley Bioscience Center and Birck Nanotechnology Center, Purdue University (United States); McLamore, Eric S [Department of Agricultural and Biological Engineering, University of Florida (United States); Calvo-Marzal, Percy, E-mail: porterf@purdue.edu [Department of Chemistry, Purdue University (United States)

    2011-09-02

    This work addresses the comparison of different strategies for improving biosensor performance using nanomaterials. Glucose biosensors based on commonly applied enzyme immobilization approaches, including sol-gel encapsulation approaches and glutaraldehyde cross-linking strategies, were studied in the presence and absence of multi-walled carbon nanotubes (MWNTs). Although direct comparison of design parameters such as linear range and sensitivity is intuitive, this comparison alone is not an accurate indicator of biosensor efficacy, due to the wide range of electrodes and nanomaterials available for use in current biosensor designs. We proposed a comparative protocol which considers both the active area available for transduction following nanomaterial deposition and the sensitivity. Based on the protocol, when no nanomaterials were involved, TEOS/GOx biosensors exhibited the highest efficacy, followed by BSA/GA/GOx and TMOS/GOx biosensors. A novel biosensor containing carboxylated MWNTs modified with glucose oxidase and an overlying TMOS layer demonstrated optimum efficacy in terms of enhanced current density (18.3 {+-} 0.5 {mu}A mM{sup -1} cm{sup -2}), linear range (0.0037-12 mM), detection limit (3.7 {mu}M), coefficient of variation (2%), response time (less than 8 s), and stability/selectivity/reproducibility. H{sub 2}O{sub 2} response tests demonstrated that the most possible reason for the performance enhancement was an increased enzyme loading. This design is an excellent platform for versatile biosensing applications.

  4. Comparative study of microcapsules elaborated with three polycations (PLL, PDL, PLO) for cell immobilization.

    Science.gov (United States)

    De Castro, M; Orive, G; Hernández, R M; Gascón, A R; Pedraz, J L

    2005-05-01

    Alginate-poly-L-lysine (PLL)-alginate microcapsules have been widely used in cell microencapsulation technology. However, the mechanical fragility and low tensile resistance against swelling of this membrane chemistry and the difficult handling, immunogenicity and cytotoxicity of PLL have stimulated the study of novel polycations. In this paper, alginate microcapsules coated with three different polycations: poly-L-lysine (PLL), poly-D-lysine (PDL) and poly-L-ornithine (PLO) were fabricated to evaluate if the use of novel membrane chemistries (PDL, PLO) had a positive effect on the morphology, osmotic resistance and mechanical stability of the capsules as well as the viability of the immobilized C2C12 myoblast cells when compared to the classical PLL microcapsules. Results indicate that liquefied capsules presented worse mechanical properties than the polymerized solid capsules in the three type of membrane chemistries. In addition, PLL membrane chemistry exerted the highest resistance against compressions after culture in several mediums, while PDL microcapsules showed the highest resistance to the tensile stress of the osmotic pressure. No important differences were detected when the physiological activity of the enclosed cells was evaluated. In summary, although further in vivo assays are needed, in general none of the new membrane formulations represented a significant improvement over classical PLL microcapsules.

  5. Study on immobilization of lipase onto magnetic microspheres with epoxy groups

    Science.gov (United States)

    Lei, Lin; Bai, Yongxiao; Li, Yanfeng; Yi, Liuxiang; Yang, Yong; Xia, Chungu

    2009-02-01

    Magnetic microspheres were synthesized by the suspension polymerization of glycidyl methacrylate (GMA), methacrylic acid (MAA) and divinyl benzene (DVB) in the presence of oleic acid-coated Fe 3O 4 nanoparticles. Triacylglycerol lipase from porcine pancreas was covalently immobilized on the magnetic microspheres via the active epoxy groups with the activity yield up to 63% (±2.3%) and enzyme loading of 39 (±0.5) mg/g supports. The resulting immobilized lipase had higher optimum temperature compared with those of free lipase and exhibited better thermal, broader pH stability and excellent reusability. Furthermore, the catalyzed capability of immobilized lipase was also investigated by catalyzing synthesis of hexyl acetate and the esterification conversion rate reached to 83% (±2.5%) after 12 h in nonaqueous solvent.

  6. Evaluation of enzyme immobilization methods for paper-based devices--A glucose oxidase study.

    Science.gov (United States)

    Nery, Emilia Witkowska; Kubota, Lauro T

    2016-01-01

    Paper-based sensors gained almost explosive attention during the last few years. A large number of systems, often destined to resource limited settings is based on enzymatic reactions. Choice of an adequate immobilization method could significantly prolong the shelf-life of such sensors, especially in applications, where exposure to high temperatures during storage and transport is more than a threat. We are seeking to compare a variety of immobilization methods based on different phenomena (adsorption, entrapment in gel, microencapsulation, covalent linkage), with total of 33 methods tested. Glucose oxidase was used as a model enzyme. Enzymatic activity of immobilized samples was accompanied for a period of 24 weeks considering two sets of samples, one stored in 4 °C and other in ambient temperature.

  7. STUDY ON ALCOHOLIC FERMENTATION IN A STATIONARY BASKET BIOREACTOR WITH IMMOBILIZED YEAST CELLS

    Directory of Open Access Journals (Sweden)

    Dan Caşcaval

    2011-02-01

    Full Text Available The use of a stationary basket bioreactor with immobilized S. cerevisiae cells indicated the possibility to extend the number of alcoholic fermentation cycles that can be carried out with the same biocatalysts to over nine. Although the rates of glucose consumption and ethanol production were lower than those recorded for the mobile beds of immobilized yeast cells, the mechanical lysis of the biocatalysts is avoided in the case of basket bed. Due to the substrate and product accumulation inside the basket bed, the fermentation process can be improved by washing out the biocatalysts bed over two or four cycles.

  8. Immobilization and condensation of DNA with 3-aminopropyltriethoxysilane studied by atomic force microscopy.

    Science.gov (United States)

    Liu, Z; Li, Z; Zhou, H; Wei, G; Song, Y; Wang, L

    2005-06-01

    We used different methods to modify a mica surface with 3-aminopropyltriethoxysilane (APTES), and then used it as substrate to immobilize DNA for atomic force microscopy (AFM) observation. The evaporation method and solution modifying method were investigated and evaluated. The solution modifying method was found to be relatively simple and effective. Using an APTES solution-modified mica surface, DNA immobilization appeared more reproducible and it could be imaged in liquid. The mixed solution of APTES and DNA was dropped directly onto the mica surface for AFM imaging. We found that DNA can condense in APTES water solutions. Toroids, rods and intermediate structures of condensation were captured by AFM.

  9. Scanning electron microscopy study of protein immobilized on SIO2 Sol-gel surfaces

    Directory of Open Access Journals (Sweden)

    O.B.G. Assis

    2003-09-01

    Full Text Available Uniform attachment of enzymes to solid surfaces is essential in the development of bio and optical sensor devices. Immobilization by adsorption according to hydrophilic or hydrophobic nature is dependent on the charges and defects of the support surfaces. Sol-gel SiO2 densified glass surfaces, frequently used as supports for protein immobilization, are evaluated via scanning electron microscopy. The model protein is globular enzyme lysozyme, deposited by adsorption on functionalized surfaces. Formation of a protein layer is confirmed by FTIR spectroscopy, and the SEM images suggest discontinuous adsorption in areas where cracks predominate on the glass surface.

  10. Stretching and immobilization of DNA for studies of protein–DNA interactions at the single-molecule level

    Directory of Open Access Journals (Sweden)

    Dukkipati VenkatRam

    2007-01-01

    Full Text Available AbstractSingle-molecule studies of the interactions of DNA and proteins are important in a variety of biological or biotechnology processes ranging from the protein’s search for its DNA target site, DNA replication, transcription, or repair, and genome sequencing. A critical requirement for single-molecule studies is the stretching and immobilization of otherwise randomly coiled DNA molecules. Several methods for doing so have been developed over the last two decades, including the use of forces derived from light, magnetic and electric fields, and hydrodynamic flow. Here we review the immobilization and stretching mechanisms for several of these techniques along with examples of single-molecule DNA–protein interaction assays that can be performed with each of them.

  11. Removal of mercury (II) from aqueous solution using papain immobilized on alginate bead: optimization of immobilization condition and modeling of removal study.

    Science.gov (United States)

    Bhattacharyya, Aparupa; Dutta, Susmita; De, Parameswar; Ray, Parthasarathi; Basu, Srabanti

    2010-12-01

    Papain having the characteristics of metal binding ability is immobilized on alginate bead. Design Expert Software (Version 7.1.6) uses Response Surface Methodology (RSM) for statistical designing of operating condition for immobilization of papain on alginate bead considering concentration of papain, concentration of sodium alginate, concentration of calcium chloride and pH as numeric factors and Specific Enzymatic Activity (SEA) of immobilized papain sample as response. Immobilization using 25.96 g/L papain, 20 g/L sodium alginate and 20 g/L calcium chloride at pH 7 gives the desired product as indicated by ANOVA (Analysis of Variance). Three parameters viz., initial concentration of mercury (II), amount of AIP and pH are varied in a systematic manner. Maximum 98.88% removal of mercury (II) has been achieved within 8 min when simulated aqueous solution of mercury (II) with initial concentration of 10mg/L has been contacted with 5 g of AIP at pH 9 and at 35 degrees C in a batch contactor. A mathematical model has been developed and the value of equilibrium constant for binding of mercury (II) with AIP has been found to be 126797.3.

  12. Cervical Spine Immobilization in Sports Related Injuries: Review of Current Guidelines and a Case Study of an Injured Athlete

    OpenAIRE

    Bhamra, JS; Morar, Y; Khan, WS; Deep, K.; Hammer, A.

    2012-01-01

    Cervical spine immobilization is an essential component of the ATLS® system. Inadequate training in the management of trauma calls and failure of early recognition can have disastrous consequences. Pre-hospital personnel are routinely involved more in the assessment and stabilization of patients in comparison to other health care professionals. This case study and review highlights the importance of early recognition, assessment and correct stabilization of cervical spine injuries both in the...

  13. Immobilization of ionophore and surface characterization studies of the titanium(III) ion in a PVC-membrane sensor.

    Science.gov (United States)

    Rezayi, Majid; Heng, Lee Yook; Kassim, Anuar; Ahmadzadeh, Saeid; Abdollahi, Yadollah; Jahangirian, Hossein

    2012-01-01

    Novel ionophores comprising various hydroxide and amine structures were immobilized onto poly(vinyl chloride) (PVC) matrices, and these were examined to determine Ti(III) selectivity. To predict the selectivity of Ti(III), a PVC membrane was used to investigate the binding of Ti(III) to c-methylcalix[4]resorcinarene (CMCR). The study showed that the chelating ligand, CMCR, was coordinated selectively to Ti(III) at eight coordination sites involving the oxygen atoms at the interface of the membrane/solution. The membrane was prepared, based on CMCR as an ionophore, sodium tetrakis(4-fluorophenyl) borate (NaTFPB) as a lipophilic ionic additive, and dioctylphthalate (DOP) as a plasticizer. The immobilization of the ionophore and surface characterization studies revealed that the performance of CMCR-immobilized PVC was equivalent to that of mobile ionophores in supported liquid membranes (SLMs). The strengths of the ion-ionophore (CMCR-Ti(OH)(OH(2))(5) (2+)) interactions and the role of ionophores on membranes were studied via UV-Vis, Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and and X-ray diffraction (XRD).

  14. Immobilization of Ionophore and Surface Characterization Studies of the Titanium(III Ion in a PVC-Membrane Sensor

    Directory of Open Access Journals (Sweden)

    Majid Rezayi

    2012-06-01

    Full Text Available Novel ionophores comprising various hydroxide and amine structures were immobilized onto poly(vinyl chloride (PVC matrices, and these were examined to determine Ti(III selectivity. To predict the selectivity of Ti(III, a PVC membrane was used to investigate the binding of Ti(III to c-methylcalix[4]resorcinarene (CMCR. The study showed that the chelating ligand, CMCR, was coordinated selectively to Ti(III at eight coordination sites involving the oxygen atoms at the interface of the membrane/solution. The membrane was prepared, based on CMCR as an ionophore, sodium tetrakis(4-fluorophenyl borate (NaTFPB as a lipophilic ionic additive, and dioctylphthalate (DOP as a plasticizer. The immobilization of the ionophore and surface characterization studies revealed that the performance of CMCR-immobilized PVC was equivalent to that of mobile ionophores in supported liquid membranes (SLMs. The strengths of the ion-ionophore (CMCR-Ti(OH(OH252+ interactions and the role of ionophores on membranes were studied via UV-Vis, Fourier transform infrared spectroscopy (FT–IR, scanning electron microscopy (SEM and and X-ray diffraction (XRD.

  15. Treatment of textile effluent in a developed phytoreactor with immobilized bacterial augmentation and subsequent toxicity studies on Etheostoma olmstedi fish

    Energy Technology Data Exchange (ETDEWEB)

    Watharkar, Anuprita D. [Department of Biotechnology, Shivaji University, Kolhapur (India); Khandare, Rahul V. [School of Life Sciences, North Maharashtra University, Jalgaon (India); Waghmare, Pankajkumar R.; Jagadale, Ashwini D.; Govindwar, Sanjay P. [Department of Biochemistry, Shivaji University, Kolhapur (India); Jadhav, Jyoti P., E-mail: jpj_biochem@unishivaji.ac.in [Department of Biotechnology, Shivaji University, Kolhapur (India); Department of Biochemistry, Shivaji University, Kolhapur (India)

    2015-02-11

    Graphical abstract: - Highlights: • A phytoreactor was developed and augmented with immobilized bacteria. • This consortium showed enhanced treatment than the individual species. • Oxido-reductases from P. crinitum and B. pumilus could decolorize the effluent. • Characterization of effluent samples endorsed the efficacy of consortial strategy. • Toxicity studies revealed the less toxic nature of the consortium treated effluent. - Abstract: A static hydroponic bioreactor using nursery grown plants of Pogonatherum crinitum along with immobilized Bacillus pumilus cells was developed for the treatment of textile wastewater. Independent reactors with plants and immobilized cells were also kept for performance and efficacy evaluation. The effluent samples characterized before and after their treatment showed that the plant–bacterial consortium reactor was more efficient than those of individual plant and bacterium reactors. COD, BOD, ADMI, conductivity, turbidity, TDS and TSS of the textile effluent was found to be reduced by 78, 70, 93, 4, 90, 13 and 70% respectively within 12 d by the consortial set. HPTLC analysis revealed the transformation of the textile effluent to new products. The phytotoxicity study on Phaeseolus mungo and Sorghum vulgare seeds showed reduced toxicity of treated effluents. The animal toxicity study performed on Etheostoma olmstedi fishes showed the toxic nature of untreated effluent giving extreme stress to fishes leading to death. Histology of fish gills exposed to treated effluent was found to be less affected. The oxidative stress related enzymes like superoxide dismutase and catalase were found to show decreased activities and less lipid peroxidation in fishes exposed to treated effluent.

  16. Comparative study between yeasts immobilized on alumina beads and on membranes prepared by two routes

    Directory of Open Access Journals (Sweden)

    Kiyohara Pedro K.

    2003-01-01

    Full Text Available Alumina channeled beads and rough surface membranes prepared from aqueous sols of fibrillar pseudoboehmite are able to immobilize yeasts for ethanol fermentation of sugar solutions. This paper describes comparative results of assays carried out with yeasts immobilized onto alpha-alumina beads and membranes prepared under two different conditions of processing and firing. The fermentation tests evaluated by the decrease of fermentable sugars, referred as Brix degrees per hour, indicated that the yeasts immobilized on beads had similar performance, probably because their surfaces, even being morphologically different, presented the same value of open porosity. One type of membrane (asymmetrical; precursor: pseudoboehmite; firing temperature 1,150ºC; crystal structure; alpha-alumina had better performance than the other type (asymmetrical; precursor: fibrillar pseudoboehmite plus aluminum hydroxiacetate mixture; 1,150ºC; alpha-alumina because the yeast cells entered into their porous interior through the surface slits, were immobilized and their growth was easier than on the external surface.

  17. Antagonism of Gluconacetobacter diazotrophicus (a sugarcane endosymbiont) against Xanthomonas albilineans (pathogen) studied in alginate-immobilized sugarcane stalk tissues.

    Science.gov (United States)

    Blanco, Yolanda; Blanch, María; Piñón, Dolores; Legaz, María-Estrella; Vicente, Carlos

    2005-04-01

    Xanthomonas albilineans, a pathogenic bacterium that produces leaf scald disease of sugarcane, secretes a xanthan-like gum that invades both xylem and phloem of the host. Xanthan production has been verified after experimental infection of stalk segments of healthy plants. Moreover, Gluconacetobacter diazotrophicus is a nitrogen-fixing endosymbiont of sugarcane plants that antagonizes with X. albilineans by impeding the production of the bacterial gum. The physiological basis of this antagonism has been studied using tissues of sugarcane stalks previously inoculated with the endosymbiont, then immobilized in calcium alginate and maintained in a culture medium for Gluconacetobacter. Under these conditions, bacteria infecting immobilized tissues are able to secrete to the medium a lysozyme-like bacteriocin that inhibits the growth of X. albilineans.

  18. Study on the mechanism of Bioelectric Recognition Assay: evidence for immobilized cell membrane interactions with viral fragments.

    Science.gov (United States)

    Kintzios, S; Bem, F; Mangana, O; Nomikou, K; Markoulatos, P; Alexandropoulos, N; Fasseas, C; Arakelyan, V; Petrou, A-L; Soukouli, K; Moschopoulou, G; Yialouris, C; Simonian, A

    2004-11-01

    The Bioelectric Recognition Assay (BERA) is a whole-cell based biosensing system that detects the electric response of cultured cells, suspended in a gel matrix, to various ligands, which bind to the cell and/or affect its physiology. Previous studies have demonstrated the potential application of this method for rapid, inexpensive detection of viruses in a crude sample. However, the understanding, so far, of the fundamental processes that take place during cell-virus interactions within the probe has been rather limited. In the present study, we combined electrophysiological and fluorescence microscopical assays, so that we can prove that animal and plant cells immobilized in BERA sensors respond to different viruses primarily by changing their membrane potential. The response of immobilized cells against different viruses did not depend on the virus ability to penetrate the cell, but was modified after binding each virus to a virus-specific antibody or removal of its coat protein after treatment with a protease. Consequently, we were able to assay the presence of a virus in its complete form or fragments thereof. Combination of immunological recognition with the electrophysiological response of immobilized cells allows for a considerable increase of the specificity of the BERA biosensory assay. In addition, rather than simply detect the presence of a protein or genomic sequence, the method can help gain information on the bioactivity of a virus.

  19. Study of reaction parameters and kinetics of esterification of lauric acid with butanol by immobilized Candida antarctica lipase.

    Science.gov (United States)

    Shankar, Sini; Agarwal, Madhu; Chaurasia, S P

    2013-12-01

    Esterification of lauric acid with n-butanol, catalyzed by immobilized Candida antarctica lipase (CAL) in aqueous-organic biphasic solvent system was studied. Effects of various reaction parameters on esterification were investigated, such as type and amount of solvent, amount of buffer, pH, temperature, speed of agitation, amount of enzyme, butanol and lauric acid. The most suitable reaction conditions for esterification were observed at 50 degrees C and pH 7.0 using 5000 micromoles of lauric acid, 7000 pmoles of butanol, 0.25 ml phosphate buffer, 1 ml of isooctane as the solvent and 50 mg of immobilized enzyme in the reaction medium at agitation speed of 150 rpm. Maximum esterification of 96.36% was acheived in 600 min of reaction time at n-butanol to lauric acid molar ratio of 1: 0.7. Kinetic study for the esterification of lauric acid with n-butanol using immobilized CAL was carried out and the kinetic constants were estimated by using non-linear regression method. The estimated value of Michaelis kinetic constants for butanol (KmBt) and acid (KmAc) were 451.56 (M) and 4.7 x 10(-7)(M), respectively and the value of dissociation constant (KBt) of the butanol-lipase complex was 9.41 x 10(7)(M). The estimated constants agreed fairly well with literature data.

  20. Thermodynamic study of an unusual chiral separation. Propranolol enantiomers on an immobilized cellulase

    Energy Technology Data Exchange (ETDEWEB)

    Fornstedt, T.; Sajonz, P.; Guiochon, G. [Univ. of Tennessee, Knoxville, TN (United States)]|[Oak Ridge National Lab., TN (United States)

    1997-02-12

    The thermodynamics of interaction of (R)- and (S)-propranolol between an acetic acid buffer (pH = 4.7 and 5.5) and the protein cellobiohydrolase I immobilized on silica gel was studied between 5 and 45{degree}C. The equilibrium data were fitted to a biLangmuir adsorption isotherm with excellent agreement. One of the two Langmuir contributions is the same for both enantiomers and accounts for the nonspecific interactions between these compounds and most sites on the surfaces (type-I, nonselective sites). It has a large saturation capacity. The second contribution accounts for the chiral selective interactions (type-II sites). It has a lower monolayer capacity than the first. The interaction enthalpy and entropy on type-I sites are -1.1 kcal/mol and +0.1 cal/(mol K), respectively. For type-II sites, they are -1.9 kcal/mol and -2.6 cal/(mol K), respectively, for (R)-propranolol and +1.6 kcal/mol and +11.6 cal/(mol K), respectively, for (S)-propranolol at pH = 5.5. This explains why at this pH the retention time of the less-retained R enantiomer decreases with increasing temperature, while the retention time of the S enantiomer increases, causing a large increase of the separation factor when the temperature is raised from 5 to 45{degree}C. The saturation capacity of the chiral contributions depends strongly on the pH, and the retention times of both enantiomers decrease with increasing temperature at pH = 4.7. 46 refs., 6 figs., 5 tabs.

  1. Comparative Study on the Photodegradation of Acid Black 26 from Synthetic Wastewater using Slurry and Immobilized TiO2 on the Sackcloth Fiber

    National Research Council Canada - National Science Library

    Somayeh Alijani; Mohammad Vaez; Abdolsamad Zaringhalam Moghadam

    2013-01-01

    ... water cycle during the dying process. In this study, the decolorization of Acid Black 26, as the model organic contaminant, was investigated using immobilized nano-sized TiO2 particles as the photocatalyst...

  2. Characteristics of Immobilized Urease on Grafted Alginate Bead Systems

    OpenAIRE

    Enas N. Danial; Amal H. Hamza; Rasha H. Mahmoud

    2015-01-01

    This study evaluated the biological importance of immobilized urease enzyme over the free urease. The support material used for urease immobilization was alginate. Generally, the immobilization of urease in alginate gel showed a marked increase in Km and Vmax. However, the immobilized urease showed higher thermal stability than that of free enzyme. The rate of thermal inactivation of the immobilized enzyme decreased due to entrapment in gel matrix. Also, the activity of the immobilized urease...

  3. Study of Immobilization Procedure on Silver Nanolayers and Detection of Estrone with Diverged Beam Surface Plasmon Resonance (SPR Imaging

    Directory of Open Access Journals (Sweden)

    Ibrahim Abdulhalim

    2013-03-01

    Full Text Available An immobilization protocol was developed to attach receptors on smooth silver thin films. Dense and packed 11-mercaptoundecanoic acid (11-MUA was used to avoid uncontrolled sulfidization and harmful oxidation of silver nanolayers. N,N'-dicyclohexylcarbodiimide (DCC and N-hydroxysuccinimide (NHS were added to make the silver surfaces reactive. A comparative study was carried out with different immersion times of silver samples in 11-MUA solutions with different concentrations to find the optimum conditions for immobilization. The signals, during each step of the protocol, were analyzed with a refractometer based on the surface plasmon resonance (SPR effect and luminescence techniques. Molecular interactions at the surfaces between the probe and target at the surface nanolayer shift the SPR signal, thus indicating the presence of the substance. To demonstrate specific biosensing, rabbit anti-estrone polyclonal immunoglobulin G (IgG antibody was immobilized through a linker on 47 nm silver layer deposited on SF11 glass. At the final stage, the representative endocrine disruptor—estrone—was attached and detected in deionized water with a diverging beam SPR imaging sensor.

  4. Biosorption of copper (II) onto immobilized cells of Pycnoporus sanguineus from aqueous solution: Equilibrium and kinetic studies

    Energy Technology Data Exchange (ETDEWEB)

    Yus Azila Yahaya [School of Chemical Engineering, Universiti Sains Malaysia, Seri Ampangan, 14300 Nibong Tebal, Seberang Prai Selatan, Pulau Pinang (Penang) (Malaysia); Mashitah Mat Don [School of Chemical Engineering, Universiti Sains Malaysia, Seri Ampangan, 14300 Nibong Tebal, Seberang Prai Selatan, Pulau Pinang (Penang) (Malaysia)], E-mail: chmashitah@eng.usm.my; Subhash Bhatia [School of Chemical Engineering, Universiti Sains Malaysia, Seri Ampangan, 14300 Nibong Tebal, Seberang Prai Selatan, Pulau Pinang (Penang) (Malaysia)

    2009-01-15

    The ability of white-rot fungus, Pycnoporus sanguineus to adsorb copper (II) ions from aqueous solution is investigated in a batch system. The live fungus cells were immobilized into Ca-alginate gel to study the influence of pH, initial metal ions concentration, biomass loading and temperature on the biosorption capacity. The optimum uptake of Cu (II) ions was observed at pH 5 with a value of 2.76 mg/g. Biosorption equilibrium data were best described by Langmuir isotherm model followed by Redlich-Peterson and Freundlich models, respectively. The biosorption kinetics followed the pseudo-second order and intraparticle diffusion equations. The thermodynamic parameters enthalpy change (10.16 kJ/mol) and entropy change (33.78 J/mol K) were determined from the biosorption equilibrium data. The FTIR analysis showed that -OH, -NH, C-H, C=O, -COOH and C-N groups were involved in the biosorption of Cu (II) ions onto immobilized cells of P. sanguineus. The immobilized cells of P. sanguineus were capable of removing Cu (II) ions from aqueous solution.

  5. Comparative studies on the properties of tryptophanase and tyrosine phenol-lyase immobilized directly on Sepharose or by use of Sepharose-bound pyridoxal 5'-phosphate.

    Science.gov (United States)

    Fukui, S; Ikeda, S; Fujimura, M; Yamada, H; Kumagai, H

    1975-02-01

    Tryptophanase from Escherichia coli B/qt 7-A and tyrosine phenol-lyase (beta-tyrosinase) from Escherichia intermedia were immobilized on Sepharose 4B by several direct coupling reactions or through pyridoxal 5'-phosphate previously bound to Sepharose. The most active preparation of immobilized tryptophanase was obtained by coupling tetrameric apoenzyme to pyridoxal-P bound on Sepharose at the 6-position through a diazo linkage. This immobilization procedure involves the formation to Schiff base linkage between 4-formyl group of Sepharose-bound pyridoxal-P and the epsilon-amino group of the lysine residue at the active center of one subunit of tetrameric apo-tryptophanase, followed by the fixation of the Schiff base linkage by reduction with NaBH4. In the case of beta-tyrosinase having two catalytic centers, however, this method was not so suitable as the case of tryptophanase. Direct coupling of the apoenzyme to CNBr-activated Sepharose or to a bromoacetyl derivative of Sepharose gave better results. In each case, the affinity for substrate or coenzyme was scarcely influenced by the immobilization. When used repeatedly in a batch system or continuously in a flow system in the absence of added pyridoxal-P, immobilized holo-tryptophanase of holo-beta-tyrosinase gradually lost its original activity; however, supplement of pyridoxal-P to the reaction system restored its initial activity. From the kinetic analyses of these phenomena, the rate constants of coenzyme dissociation from immobilized tryptophanase and beta-tyrosinase were calculated. Upon immobilization, the pH optima of both enzymes shifted 0.5 to 1.0 pH unit to the alkaline side. Both immobilized enzymes showed higher thermal stability and resistance to a denaturing agent such as guinidine-HCl than their free counterpart. Furthermore, the reactivity of sulfhydryl group of beta-tyrosinase, in connection with its coenzyme-binding property, was conveniently studied by use of the immobilized enzyme.

  6. PRELIMINARY STUDY OF CERAMICS FOR IMMOBILIZATION OF ADVANCED FUEL CYCLE REPROCESSING WASTES

    Energy Technology Data Exchange (ETDEWEB)

    Fox, K.; Billings, A.; Brinkman, K.; Marra, J.

    2010-09-22

    The Savannah River National Laboratory (SRNL) developed a series of ceramic waste forms for the immobilization of Cesium/Lanthanide (CS/LN) and Cesium/Lanthanide/Transition Metal (CS/LN/TM) waste streams anticipated to result from nuclear fuel reprocessing. Simple raw materials, including Al{sub 2}O{sub 3}, CaO, and TiO{sub 2} were combined with simulated waste components to produce multiphase ceramics containing hollandite-type phases, perovskites (particularly BaTiO{sub 3}), pyrochlores, zirconolite, and other minor metal titanate phases. Identification of excess Al{sub 2}O{sub 3} via X-ray Diffraction (XRD) and Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM/EDS) in the first series of compositions led to a Phase II study, with significantly reduced Al{sub 2}O{sub 3} concentrations and increased waste loadings. Three fabrication methodologies were used, including melting and crystallizing, pressing and sintering, and Spark Plasma Sintering (SPS), with the intent of studying phase evolution under various sintering conditions. XRD and SEM/EDS results showed that the partitioning of the waste elements in the sintered materials was very similar, despite varying stoichiometry of the phases formed. The Phase II compositions generally contained a reduced amount of unreacted Al{sub 2}O{sub 3} as identified by XRD, and had phase assemblages that were closer to the initial targets. Chemical composition measurements showed no significant issues with meeting the target compositions. However, volatilization of Cs and Mo was identified, particularly during melting, since sintering of the pressed pellets and SPS were performed at lower temperatures. Partitioning of some of the waste components was difficult to determine via XRD. SEM/EDS mapping showed that those elements, which were generally present in small concentrations, were well distributed throughout the waste forms. Initial studies of radiation damage tolerance using ion beam irradiation at Los

  7. Uranium Immobilization through Fe(II) bio-oxidation: A Column study

    Energy Technology Data Exchange (ETDEWEB)

    Coates, John D.

    2009-09-14

    Current research on the bioremediation of heavy metals and radionuclides is focused on the ability of reducing organisms to use these metals as alternative electron acceptors in the absence of oxygen and thus precipitate them out of solution. However, many aspects of this proposed scheme need to be resolved, not the least of which is the time frame of the treatment process. Once treatment is complete and the electron donor addition is halted, the system will ultimately revert back to an oxic state and potentially result in the abiotic reoxidation and remobilization of the immobilized metals. In addition, the possibility exists that the presence of more electropositive electron acceptors such as nitrate or oxygen will also stimulate the biological oxidation and remobilization of these contaminants. The selective nitrate-dependent biooxidation of added Fe(II) may offer an effective means of “capping off” and completing the attenuation of these contaminants in a reducing environment making the contaminants less accessible to abiotic and biotic reactions and allowing the system to naturally revert to an oxic state. Our previous DOE-NABIR funded studies demonstrated that radionuclides such as uranium and cobalt are rapidly removed from solution during the biogenic formation of Fe(III)-oxides. In the case of uranium, X-ray spectroscopy analysis indicated that the uranium was in the hexavalent form (normally soluble) and was bound to the precipitated Fe(III)-oxides thus demonstrating the bioremediative potential of this process. We also demonstrated that nitrate-dependent Fe(II)- oxidizing bacteria are prevalent in the sediment and groundwater samples collected from sites 1 and 2 and the background site of the NABIR FRC in Oakridge, TN. However, all of these studies were performed in batch experiments in the laboratory with pure cultures and although a significant amount was learned about the microbiology of nitrate-dependent bio-oxidation of Fe(II), the effects of

  8. Studies on Acetone Powder and Purified Rhus Laccase Immobilized on Zirconium Chloride for Oxidation of Phenols

    Directory of Open Access Journals (Sweden)

    Rong Lu

    2012-01-01

    Full Text Available Rhus laccase was isolated and purified from acetone powder obtained from the exudates of Chinese lacquer trees (Rhus vernicifera from the Jianshi region, Hubei province of China. There are two blue bands appearing on CM-sephadex C-50 chromatography column, and each band corresponding to Rhus laccase 1 and 2, the former being the major constituent, and each had an average molecular weight of approximately 110 kDa. The purified and crude Rhus laccases were immobilized on zirconium chloride in ammonium chloride solution, and the kinetic properties of free and immobilized Rhus laccase, such as activity, molecular weight, optimum pH, and thermostability, were examined. In addition, the behaviors on catalytic oxidation of phenols also were conducted.

  9. Silica-Immobilized Enzyme Reactors; Application to Cholinesterase-Inhibition Studies

    Science.gov (United States)

    2006-03-01

    PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 6. AUTHOR(S) 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION ...Physical methods include dsorption of biomolecules to a porous support or ion exchange atrix , or entrapment within an insoluble gel matrix. Several...Many methods of immobilization and entrapment lso cause significant structural deformation of the enzyme, eading to reduction in activity. Significant

  10. In vitro and in vivo studies of lead immobilization by synthetic hydroxyapatite

    Energy Technology Data Exchange (ETDEWEB)

    Arnich, Nathalie; Lanhers, Marie-Claire; Laurensot, Franck; Podor, Renaud; Montiel, Antoine; Burnel, Daniel

    2003-07-01

    Lead immobilization by solid hydroxyapatite significantly reduces lead concentration and bioavailability in water. - Apatite appears a useful compound for removing lead from water, due to its ability to immobilize the metal by precipitation. In dilute solution, dissolved hydroxyapatite [HA, Ca{sub 10}(PO{sub 4}){sub 6}(OH){sub 2}] provided phosphates that were reactive with aqueous lead (molar ratio HA/Pb=1/10) forming precipitates at around pH 6. These dissolved at a more acidic pH (3). Solid HA in contact with Pb{sup 2+} ions, led to the formation of pyromorphite [Pb{sub 10}(PO{sub 4}){sub 6}(OH){sub 2}], identified by X-ray diffraction and insoluble at pH tested (3-8). The amount of pyromorphite increased with the weight ratio of HA/Pb. When this one increased from 1 to 1000, lead precipitated as pyromorphite rose from 19 to 99%. In vivo experiments on rats confirmed the in vitro results. In fact, lead bioavailability assessed by intestinal perfusion was unchanged in the presence of dissolved HA, whereas it was significantly lower in the presence of solid HA, evaluated by gastric intubation, at a weight ratio equal to 10 (amount of lead absorbed decreased by 60%). Apatite could be an effective means of immobilizing lead in drinking or sewage, since accidental pyromorphite ingestion does not yield bioavailable lead.

  11. Integrated immobilized cell reactor-adsorption system for beta-cyclodextrin production: a model study using PVA-cryogel entrapped Bacillus agaradhaerens cells.

    Science.gov (United States)

    Martins, Rita F; Plieva, Fatima M; Santos, Ana; Hatti-Kaul, Rajni

    2003-09-01

    Production of cyclodextrins (CDs) by immobilized cells of the alkaliphilic Bacillus agaradhaerens LS-3C with integrated product recovery was studied. The microorganism was entrapped in polyvinyl alcohol-cryogel beads and used as a convenient source of immobilized cyclodextrin glycosyltransferase (CGTase). On activation by incubation in the cultivation medium containing 1% (w/v) starch, the entrapped cells multiplied and secreted CGTase with an activity of 2-3 mg beta-cyclodextrin h(-1) g(-1) beads. The immobilized biocatalyst exhibited maximum activity at pH 9 and 50 degrees C, and formed cyclodextrins comprising 92-94% beta-CD and remaining alpha-CD. The cyclodextrin product from the immobilized cell bioreactor was continuously recovered by adsorption to Amberlite XAD-4 in a recycle batch mode. The product adsorption was facilitated at low temperature while hot water was used for elution.

  12. Study on Immobilized Algal Cells for Treatment and Recycle of Refinery Wastewater

    Institute of Scientific and Technical Information of China (English)

    Yu Baocheng; Liu Deqi; Dong Lihua; Li Gang

    2005-01-01

    Compared to the algal oxidation pond, treatment of wastewater using the immobilized algal cell technology has excellent effect, which not only can effectively avoid the disadvantage of oxidation pond,but can also remarkably improve the efficiency of treating system and the effluent quality. When the treating system operates under an optimal control conditions, such as a 55% loading rate, an illumination intensity of 2500-3500 lux and a hydraulic residence time of 4 hours, the COD and ammonia nitrogen removal can reach 90%. Water after deep treatment can comply with the requirement of the refinery for the quality of recycled water.

  13. Sulfur immobilization and lithium storage on defective graphene: A first-principles study

    Science.gov (United States)

    Zhao, Wen; Chen, Pengcheng; Tang, Peizhe; Li, Yuanchang; Wu, Jian; Duan, Wenhui

    2014-01-01

    Motivated by the recent progresses and remaining technical challenges in Li-S battery, we employ defective graphene as a prototype cathode framework to illustrate how battery performance is influenced by the mesoporous carbon materials. We show that the immobilization of S unavoidably sacrifices its ability to further interact with Li, which leads to an enhanced cycle life but a decreased capacity. Based on our calculated results, we suggest a suitable S binding-energy range of ˜4-5 eV to balance the battery stability and capability under thermodynamic equilibrium conditions. Our results may promote the understanding and architecture design of Li-S battery.

  14. Study on the Adsorption of Metal Ions by Immobilized Marine Algae with the Existence of Clay

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The process of adsorption of metal ions by immobilized marine algae with the existence of clay was investigated. It can be noted from the results that, after mixing with clay,the adsorption rate increases rapidly with the increasing amount of the marine algae. When pH=5, the best ratio between the clay and the marine algae is 1:4 for Pb2+. The result of in situ handling of the waste water containing heavy metals shows that the average adsorption rates of heavy metal irons Cu2+, Cd2+, Pb2+ and Ni2+ are all over 70 %.

  15. Kinetic study on the enzymatic esterification of octanoic acid and hexanol by immobilized Candida antarctica lipase B

    DEFF Research Database (Denmark)

    Lopresto, Catia Giovanna; Calabro, Vincenza; Woodley, John M.;

    2014-01-01

    tThis study investigates reaction kinetics of the esterification of octanoic acid and hexanol into hexyloctanoate, catalyzed by an immobilized Candida antarctica lipase (Novozym®435). The product is considered natural and used as a fresh vegetable and fruity flavour additive in food, cosmetic...... a Ping-Pong bi-bi mechanism with dead-end inhibition by both substrates and, based on the proposed model, the kinetic constants of the esterification reaction are estimated. These parameters are verified to be intrinsic – neither external nor internal mass transfer resistances are significant...

  16. Growth of silicone-immobilized bacteria on polycarbonate membrane filters, a technique to study microcolony formation under anaerobic conditions

    DEFF Research Database (Denmark)

    Højberg, Ole; Binnerup, S. J.; Sørensen, Jan

    1997-01-01

    A technique was developed to study microcolony formation by silicone- immobilized bacteria on polycarbonate membrane filters under anaerobic conditions. A sudden shift to anaerobiosis was obtained by submerging the filters in medium which was depleted for oxygen by a pure culture of bacteria....... The technique was used to demonstrate that preinduction of nitrate reductase under low-oxygen conditions was necessary for nonfermenting, nitrate-respiring bacteria, e.g., Pseudomonas spp., to cope with a sudden lack of oxygen. In contrast, nitrate-respiring, fermenting bacteria, e.g., Bacillus and Escherichia...

  17. Kinetic Measurements for Enzyme Immobilization.

    Science.gov (United States)

    Cooney, Michael J

    2017-01-01

    Enzyme kinetics is the study of the chemical reactions that are catalyzed by enzymes, with a focus on their reaction rates. The study of an enzyme's kinetics considers the various stages of activity, reveals the catalytic mechanism of this enzyme, correlates its value to assay conditions, and describes how a drug or a poison might inhibit the enzyme. Victor Henri initially reported that enzyme reactions were initiated by a bond between the enzyme and the substrate. By 1910, Michaelis and Menten were advancing their work by studying the kinetics of an enzyme saccharase which catalyzes the hydrolysis of sucrose into glucose and fructose. They published their analysis and ever since the Michaelis-Menten equation has been used as the standard to describe the kinetics of many enzymes. Unfortunately, soluble enzymes must generally be immobilized to be reused for long times in industrial reactors. In addition, other critical enzyme properties have to be improved like stability, activity, inhibition by reaction products, and selectivity towards nonnatural substrates. Immobilization is by far the chosen process to achieve these goals.Although the Michaelis-Menten approach has been regularly adapted to the analysis of immobilized enzyme activity, its applicability to the immobilized state is limited by the barriers the immobilization matrix places upon the measurement of compounds that are used to model enzyme kinetics. That being said, the estimated value of the Michaelis-Menten coefficients (e.g., V max, K M) can be used to evaluate effects of immobilization on enzyme activity in the immobilized state when applied in a controlled manner. In this review enzyme activity and kinetics are discussed in the context of the immobilized state, and a few novel protocols are presented that address some of the unique constraints imposed by the immobilization barrier.

  18. Immobilization of laccase for biotechnology applications.

    Science.gov (United States)

    Sanlıer, Senay Hamarat; Gider, Simge; Köprülü, Alper

    2013-08-01

    Laccase played an important role in the decolorization of wide spectrum dyes as a low-cost and environmentally friendly technology. Laccase was immobilized in alginate beads and immobilization conditions were identified. 25 mg/ml laccase enzyme encapsulation efficiencies of using the prepared bead was calculated as approximately 94%. At the end of the 10 days of storage, the free laccase and immobilized laccase retained about 8.08% and 80.83%, respectively. The decolorization of the dye (Direct Blue 2) was around 86% for immobilized enzyme at 45°C. In the study, compared to the free enzyme, high activity, stable, reusable immobilized enzyme preparation was prepared.

  19. Experimental Study on Denitrification Using Coated Electrode of Immobilized Denitrifying Bacteria

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Objective To develop a coated electrode of immobilized denitrificants and to evaluate the performance of a bioelectrochemical reactor to enhance and control denitrification. Methods Denitrifying bacteria were developed by batch incubation and immobilized with polyvinyl alcohol (PVA) on the surface of activated carbon fiber (ACF) to make a coated electrode. Then the coated electrode (cathode) and graphite electrode (anode) were transferred to the reactor to reduce nitrate. Results After acclimated to the mixtrophic and autotrophic denitrification stages, the denitrifying bacteria could use hydrogen as an electron donor to reduce nitrate. When the initial nitrate concentration was 30.2 mg NO3--N/L, the denitrification efficiency was 57.3% at an applied electric current of 15 mA and a hydraulic retention time (HRT) of 12 hours.Correspondingly, the current density was 0.083 mA / cm2. The nitrate removal rate of the reactor was 34.4 g NO3--N / m3·d, and the surface area loading was 1.34 g NO3--N / m2·d. Conclusion The coated electrode may keep high quantity of biomass, thus achieving a high denitrification rate. Denitrification efficiencies are related to HRT, current density, oxidation reduction potential (ORP), dissolved oxygen (DO), pH value, and temperature.

  20. Human sperm immobilization effect of Carica papaya seed extracts: an in vitro study

    Institute of Scientific and Technical Information of China (English)

    NirmalKLohiya; LalitKKothari; BManivannan; PradyumnaKMishra; NeelamPathak

    2000-01-01

    Aim: To examine if the seed extracts of Carica papaya, which showed antispermatogenic/sperm immobilization properties in animal models, could cause human sperm immobilization in vitro. Methods: Chloroform extract, benzene chromatographic fraction of the chloroform extract, its methanol and ethyl acetate sub-fractions and the isolated compounds from the sub-fractions i.e., ECP 1 & 2 and MCP 1 & 2, of the seeds of Cadca papaya were used at concentrations of 0.1%, 0.5%, 1% and 2%. Sperm motility was assessed immediately after addition of extracts and every 5 minutes thereafter for 30 minutes. Results: There were dose-dependent spermicidal effects showing an instant fall in the sperm motility to less than 20 % at 2 % concentration. Isolated compounds ECP 1 & 2 were more effective inducing a motility of less than 10%. Many of the spermatozoa became vibratory on the spot. Total inhibition of motility was observed within 20 - 25 min at all concentrations of all products. Scanning and transmission electron microscopy revealed deleterious changes in the plasma membrane of the head and mid-piece of spermatozoa. Sperm viability test and the number of abnormal spermatozoa after completion of incubation suggested that the spermatozoa were infertile. The effects were spermicidal but not spermiostatic as revealed by the sperm revival test. Conclusion: The results reveal spermicidal activity in vitro of the seed extracts of Carica papaya.

  1. A BIDISPERSE MODEL TO STUDY THE HYDROLYSIS OF MALTOSE USING GLUCOAMYLASE IMMOBILIZED IN SILICA AND WRAPPED IN PECTIN GEL

    Directory of Open Access Journals (Sweden)

    L.R.B. Gonçalves

    1997-12-01

    Full Text Available In this work, a bidisperse model is built to represent the hydrolysis of maltose using immobilized glucoamylase. The experimental set is a mixed-batch reactor, maintained at 30ºC, with pectin gel spherical particles that contain enzyme immobilized in macroporous silica. The possibility of substrate adsorption on the pectin gel is also studied because this phenomenon may result in smaller values of diffusivity. Equilibrium assays are then performed for different substrates (maltose, lactose and glucose at different temperatures and pHs. These assays show that adsorption on the pectin gel is not important for the three dextrins analysed. The bidisperse model presents a good fit with the experimental data, when using previously-estimated kinetic and mass transfer parameters (Gonçalves et al., 1997. This result shows that the methodology used (wrapping the silica in pectin gel is appropriate for experimental studies with silica, since it allows a higher degree of agitation without causing shearing

  2. Study of concentration of HPV DNA probe immobilization for cervical cancer detection based IDE biosensor

    Science.gov (United States)

    Roshila, M. L.; Hashim, U.; Azizah, N.

    2016-07-01

    This paper mainly illustrates regarding the detection process of Human Papillomavirus (HPV) DNA probe. HPV is the most common virus that infected to human by a sexually transmitted virus. The most common high-risk HPV are 16 and 18. Interdigitated electrode (IDE) device used as based of Titanium Dioxide (TiO2) acts as inorganic surface, where by using APTES as a linker between inorganic surface and organic surface. A strategy of rapid and sensitive for the HPV detection was proposed by integrating simple DNA extraction with a gene of DNA. The extraction of the gene of DNA will make an efficiency of the detection process. It will depend on the sequence of the capture probes and the way to support their attached. The fabrication, surface modification, immobilization and hybridization processes are characterized by current voltage (I-V) measurement by using KEITHLEY 6487. This strategy will perform a good sensitivity of HPV detection.

  3. KINETIC STUDIES ON BIODEGRADATION OF LIPIDS FROM OLIVE OIL MILL WASTEWATERS WITH FREE AND IMMOBILIZED Bacillus sp. CELLS

    Directory of Open Access Journals (Sweden)

    Anca-Irina Galaction

    2012-03-01

    Full Text Available The studies on the biodegradation of lipids from olive oil mill wastewater with free and immobilized Bacillus sp. cells indicated that the maximum specific rate of the process is reached at pH = 8. The use of immobilized cells allows to increasing the number of biodegradation process cycles, but reduces the rate of the process. In this case, the process rate depends on the biocatalysts size and cells concentration inside them. Thus, at bacterial cells concentration of 9 g d.w./100 mL biocatalyst, the apparent specific rate varied from 4.65 to 1.46×10-2 h-1 by increasing the biocatalyst particles diameter from 3 to 4.2 mm.The cumulated influences of the particles size and cells concentration have been included in a mathematical model for the apparent specific rate of lipids biodegradation. The model offers a good concordance with the experimental data, the average deviation being of +/- 7.38%.

  4. Bio-functionalization of electro-synthesized polypyrrole surface by heme enzyme using a mixture of Nafion and glutaraldehyde as synergetic immobilization matrix: Conformational characterization and electrocatalytic studies

    Energy Technology Data Exchange (ETDEWEB)

    ElKaoutit, Mohammed, E-mail: elkaoutit@uca.es [Departamento de Quimica Analitica, Facultad de Ciencias, Universidad de Cadiz, 11510 Puerto Real, Cadiz (Spain); Naranjo-Rodriguez, Ignacio [Departamento de Quimica Analitica, Facultad de Ciencias, Universidad de Cadiz, 11510 Puerto Real, Cadiz (Spain); Dominguez, Manuel [Departamento de Fisica de la Materia Condensada, Facultad de Ciencias, Universidad de Cadiz, 11510 Puerto Real, Cadiz (Spain); Hidalgo-Hidalgo-de-Cisneros, Jose Luis [Departamento de Quimica Analitica, Facultad de Ciencias, Universidad de Cadiz, 11510 Puerto Real, Cadiz (Spain)

    2011-10-01

    Use of a mixture of Nafion and glutaraldehyde as new immobilization matrix was described. The percentage of Nafion was optimized to prevent denaturation of horseradish peroxidase enzyme after its crosslinkage with glutaraldehyde on electro-synthesized polypyrrole surface. Topographic study by Atomic Force Microscopy (AFM) shows that the enzyme seems to have been introduced inside the ionic cluster of Nafion. The characterization of the resulting bio-interfaces by UV-vis and FT-IR shows that the intra-crosslinkage phenomena caused by the use of glutaraldehyde can be eliminated by the optimization of the concentration of Nafion additive. The secondary structure contents of native and immobilized enzyme were analyzed by a Gaussian curve fitting of the respective FT-IR spectra in the amide I region. Immobilized enzyme presented notable increasing percentages of globular and short helical structure compared with native enzyme. This indicates that immobilized enzyme was folded which is in accordance with AFM studies and supports the enzyme entrance inside ionic clutter of Nafion. Thanks to synergic effects of the polypyrrole conducting polymer and the perfluorosulfonic acid polymer Nafion, HRP enzyme was immobilized in its 'native' state, the resulting biosensor was able to sense peroxide without any chemical mediator and can be categorized as third generation.

  5. Quantitative affinity chromatographic studies of mitochondrial cytochrome c binding to bacterial photosynthetic reaction center, reconstituted in liposome membranes and immobilized by detergent dialysis and avidin--biotin binding.

    Science.gov (United States)

    Yang, Q; Liu, X Y; Hara, M; Lundahl, P; Miyake, J

    2000-04-10

    In order to study the affinity binding of c-type cytochromes to the photosynthetic reaction center (RC) by quantitative affinity chromatography (QAC), RC from Rhodobacter sphaeroides was reconstituted into liposomes composed of egg phosphatidylcholine (EPC) and 2 mol% of biotinyl phosphatidylethanolamine simultaneously as the liposomes were formed and immobilized in (strept)avidin-coupled gel beads by rotary detergent dialysis. The immobilized amount was up to 80 nmol of RC and 33 micromol of lipid/g of moist gel in streptavidin-coupled Sephacryl S-1000 gel. By QAC frontal runs, retardation of mitochondrial cyt c on immobilized RC liposome columns was demonstrated. The dissociation constant for the RC-cyt c interaction was determined to be 0.20-0.57 microM. QAC studies also allowed evaluation of the orientation of reconstituted RC in immobilized liposomes by comparison of the total amount of cyt c binding sites with the amount of available binding sites obtained by QAC. It seems that the RC proteoliposomes immobilized in Sephacryl S-1000 gel exposed the cyt c binding sites on the outer surface of the liposomes due to effects of the gel network pore size and the resulting liposomal size.

  6. Studies on Immobilization of Papain and the Properties of Immobilized Enzyme%木瓜蛋白酶的固定化及其性质研究

    Institute of Scientific and Technical Information of China (English)

    何平; 黄卓烈; 黎春怡; 巫光宏; 初志战; 詹福建

    2008-01-01

    在海藻酸钠-壳聚糖固定化木瓜蛋白酶(immobilized papin on sodium alginate-chitosan,IPSAC)的实验中,当给酶量为1 mg g1载体时,酶活性为39.2 U,酶活力回收为21.1%.在尼龙布固定化木瓜蛋白酶(knmobilized papain onnylon,IPN)的实验中,当每块尼龙布(3 cm×3 cm)给酶量为1 mg时,酶活性为35.6 U,酶活力回收为19.2%.木瓜蛋白酶(papain,PA)、IPSAC、IPN的最适pH分别为7.2、7.2和6.8.PA及IPSAC在70℃以下活性稳定;IPN在50℃以下活性稳定.IPSAC与IPN半衰期分别为59 d和66 d.

  7. Immobilization technologies for the management of hazardous industrial waste using granite waste (case study)

    Energy Technology Data Exchange (ETDEWEB)

    Lasheen, Mohamed R.; Ashmawy, Azza M.; Ibrahim, Hanan S.; Moniem, Shimaa M. Abdel [National Research Centre, Giza (Egypt)

    2016-03-15

    Full characterization of granite waste sludge (GWS) was accomplished by X-ray diffraction (XRD) and Xray fluorescence (XRF) for identification of its phase and chemical composition. Different leaching tests were conducted to determine the efficiency of the GWS for metal stabilization in hazardous sludge. The leaching of the metals from stabilized contaminated sludge was decreased as the GWS amount increased. Only 15% of GWS was sufficient for stabilization of all metal ions under investigation. The main reason for metal immobilization was attributed to the aluminosilicates or silicates matrix within the GWS, which can transform the metals in the form of their insoluble hydroxides or absorbed in the stabilized matrix. Also, solidification/stabilization technique was used for remediation of contaminated sludge. Compressive strength test after curing for 28 days was used for measuring the effectiveness of remediation technique; it was found to be 1.88MPa. This indicated that the remediated sludge was well solidified and safe to be used as a raw substance for roadway blocks. Therefore, this huge amount of by-product sludge derived from the granite cutting industry, which has a negative environmental impact due to its disposal, can be utilized as a binder material for solidification/stabilization of hazardous sludge.

  8. Electrochemical study of oxidation process of promethazine using sensor based on carbon nanotubes paste containing immobilized DNA on inorganic matrix

    Directory of Open Access Journals (Sweden)

    João Paulo Marco

    2014-10-01

    Full Text Available In the present work the voltammetric behavior and the oxidation process of promethazine (PHZ in electrochemical sensor based on carbon nanotubes paste containing DNA immobilized on the inorganic matrix prepared by sol-gel process (SiO2/Al2O3/Nb2O5. The method of Laviron verified that the system is irreversible and high speed of electron transfer between the electrode and DNA. The study of the oxidation of PHZ and influence of pH showed slope of 0.054 V / pH (near the nernstian system: 0.0592 V / pH suggesting that it involves the transfer of two protons and two electrons.

  9. Characteristics of Immobilized Urease on Grafted Alginate Bead Systems

    Directory of Open Access Journals (Sweden)

    Enas N. Danial

    2015-04-01

    Full Text Available This study evaluated the biological importance of immobilized urease enzyme over the free urease. The support material used for urease immobilization was alginate. Generally, the immobilization of urease in alginate gel showed a marked increase in Km and Vmax. However, the immobilized urease showed higher thermal stability than that of free enzyme. The rate of thermal inactivation of the immobilized enzyme decreased due to entrapment in gel matrix. Also, the activity of the immobilized urease was more stable in retention than that of the free enzyme during the storage in solution, although the activity of the immobilized enzyme was lower in comparison with the free enzyme. A stable immobilized system and long storage life are convenient for applications that would not be feasible with a soluble enzyme system. These results highlighted the technical and biochemical benefits of immobilized urease over the free enzyme.

  10. Study on Hydrolysis of Lactose in Whey by use of Immobilized Enzyme Technology for Production of Instant Energy Drink

    OpenAIRE

    2012-01-01

    The strain Kluyveromyces marxianus was selected to isolate enzyme β-galactosidase, to hydrolyze lactose in whey to prepare instant energy beverage. The cells were immobilized in 5.0% sodium alginate gel for their subsequent use in hydrolysis of lactose in whey. The immobilized cell system was found beneficial in reducing the cost of the product and increase reusability of enzyme. Various process parameters were optimized. Maximum yield of the lactose hydrolysis i.e., 81.2% was found with micr...

  11. Immobilization of Spirulina subsalsa for removal of triphenyltin from water.

    Science.gov (United States)

    Huang, Guo-Lan; Zhihui, Song

    2002-07-01

    Spirulina subsalsa is immobilized with alginate, which increases the growth rate, chlorophyll content, phycocyanin content and nitrate reductase activity. Immobilized Spirulina subsalsa with alginate increases absorption of triphenyltin chloride (TPT). The phycocyanin of immobilized Spirulina subsalsa is more sensitive to TPT then free alga. The immobilization enhances the toxic effect of TPT on nitrate reductase activity of Spirulina subsalsa. Experimental results demonstrate that the immobilization of Spirulina subsalsa is feasible. Removal of TPT by immobilized Spirulina subsalsa reaches 68%. Biosorption mechanism of TPT by Spirulina subsalsa should be further studied.

  12. Pilot Study to Evaluate Hydrogen Injection for Stimulating Reduction and Immobilization of Uranium in Groundwater at an ISR Mining Site

    Science.gov (United States)

    Clapp, L. W.; Cabezas, J.; Gamboa, Y.; Fernandez, W.

    2011-12-01

    State and federal regulations require that groundwater at in-situ recovery (ISR) uranium mining operations be restored to pre-mining conditions. Reverse osmosis (RO) filtration of several pore volumes of the post-leached groundwater and reinjection of the clean permeate is the most common technology currently used for restoring groundwater at uranium ISR sites. However, this approach does not revert the formation back to its initial reducing conditions, which can potentially impede timely groundwater restoration. In-situ biostimulation of indigenous iron- and sulfate reducing bacteria by injection of organic electron donors (e.g., ethanol, acetate, and lactate) to promote soluble uranium reduction and immobilization has been the subject of previous studies. However, injection of organic substrates has been observed to cause aquifer clogging near the injection point. In addition, U(VI) solubility may be enhanced through complexation with carbonate generated by organic carbon oxidation. An alternative approach that may overcome these problems involves the use of hydrogen as a reductant to promote microbial reduction and immobilization of U(VI) in situ. To test this approach, approximately 100,000 scf of compressed hydrogen gas was injected into a leached unconsolidated sand zone over two months at an ISR mining site. During this time groundwater was recirculated between injection and extraction wells (separated by 130 ft) at a rate of about 40 gpm and bromide was coinjected as a conservative tracer. A well monitoring program has been executed since June 2009 to evaluate the performance of the hydrogen injection. Current results show that U(VI) has been reduced from 4.2 to 0.05 ppm in the area surrounding the injection well and to 2.0 ± 0.3 ppm in the area surrounding the extraction well and two intermediate monitoring wells. Other water quality changes near the injection well include significant decreases in concentrations of Mo, sulfate, Fe, Mn, bicarbonate, Ca

  13. Direct DNA Immobilization onto a Carbon Nanotube Modified Electrode: Study on the Influence of pH and Ionic Strength

    Directory of Open Access Journals (Sweden)

    Hossain Ali Rafiee Pour

    2016-07-01

    Full Text Available Over the past years, DNA biosensors have been developed to analyze DNA interaction and damage that have important applications in biotechnological researches. The immobilization of DNA onto a substrate is one key step for construction of DNA electrochemical biosensors. In this report, a direct approach has been described for immobilization of single strand DNA onto carboxylic acid-functionalized carbon nanotubes modified glassy carbon electrode. To do this, we first modified the glassy carbon electrode surface with MWCNT-COOH. The immersion of MWCNT-COOH/GCE in ss-DNA probe solution, with different pH and ionic strength, was followed by suitable interaction between amine group of ss-DNA bases and carboxylic groups of MWCNT-COOH. This interaction leads to successful ss-DNA immobilization on MWCNT-COOH that was confirmed by cyclic voltammetry, electrochemical impedance spectroscopy and atomic force microscopy. Immobilization of ss-DNA on the modified electrode increased the charge transfer resistant but decreased the peak current of redox probe ([Fe(CN6]3-/4-. The result of cyclic voltammograms implicates that enhancements in the DNA immobilization are possible by adroit choice of low pH and high ionic strength. The standard free-energy of adsorption (ΔG°ads was calculated from electrochemical impedance spectroscopy data (-47.75 kJ mol-1 and was confirmed covalent bond formation. atomic force microscopy topographic images demonstrate increased surface roughness after ss-DNA immobilization. Results offer a simple, rapid and low-cost of DNA immobilization strategy can be opportunities to design of novel nucleic acid biosensors.

  14. Element Partitioning in Glass-Ceramic Designed for Actinides Immobilization

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>Glass-ceramics were designed for immobilization of actinides. In order to immobilizing more wastes in the matrix and to develop the optimum formulation for the glass-ceramic, it is necessary to study the

  15. Exfoliated Egyptian kaolin immobilized heteropolyoxotungstate nanocomposite as an innovative antischistosomal agent: In vivo and in vitro bioactive studies.

    Science.gov (United States)

    Bayaumy, Fatma E A; Darwish, Atef S

    2016-02-01

    This study aims to manipulate an antischistosomal nanocomposite based on exfoliated clay immobilized heteropolyoxotungstate. The nanocomposite's physicochemical characteristics were examined using XRD, Raman spectroscopy, FTIR, DLS, SEM, HR-TEM and AFM. Nano-sized spheroidal negatively charged Keggin-type heteropolyoxotungstate particles were developed along and between the exfoliated clay layers. The impact of the nanocomposite on Schistosoma mansoni-infected mice was studied through parasitological, physiological and histological analyses. Infected mice were orally vaccinated by a single nanocomposite dose (15mg/kg/day) for two weeks. The schistosomicidal activities of the nanocomposite in vitro were investigated by examining its dose- and time-dependent responses in terms of % worm mortality. The time-dependent morphological alterations in schistosomes at a nanocomposite dosage of 15μg/mL were followed by SEM. The nanocomposite exhibited potential schistosomicidal properties with a marked reduction in worm burden (~85% mortality), extensive deformities in the adult worm tegument and suckers, improvement of serum biochemical activities, and diminishment in granulomatous lesions. The in vitro release of heteropolyoxotungstate from exfoliated clay indicates the clay's ability to embrace the heteropolytungstate until its liberation at the parasitic districts. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. A pilot feasibility study of daily rTMS to modify corticospinal excitability during lower limb immobilization.

    Science.gov (United States)

    Ricci, Raffaella; Ramsey, Dave; Johnson, Kevin; Borckardt, Jeffrey J; Vallejo, Matthew; Roberts, Donna R; George, Mark S

    2008-10-01

    Short term immobilization of the lower limb is associated with increased corticospinal excitability at 24 hours post cast removal. We wondered whether daily stimulation of the motor cortex might decrease brain reorganization during casting. We tested the feasibility of this approach. Using transcranial magnetic stimulation (TMS), resting motor threshold and recruitment curves were obtained at baseline in 6 healthy participants who then had leg casts placed for 10 days. On 7 of the 10 days subjects received 20 minutes of 1 Hz repetitive TMS (rTMS). TMS measures were then recorded immediately after and 24 hours post cast removal. Four of 6 subjects completed the study. At the group level there were no changes in excitability following cast removal. At the individual level, two participants did not show any change, 1 participant had higher and one lower excitability 24 hours after cast removal. Daily rTMS over motor cortex is feasible during casting and may modify neuroplastic changes occurring during limb disuse. A prospective double blind study is warranted to test whether daily rTMS might improve outcome in subjects undergoing casting, and perhaps in other forms of limb disuse such as those following brain injury or weightlessness in space flight.

  17. Immobilization of bovine catalase onto magnetic nanoparticles.

    Science.gov (United States)

    Doğaç, Yasemin İspirli; Teke, Mustafa

    2013-01-01

    The scope of this study is to achieve carrier-bound immobilization of catalase onto magnetic particles (Fe₃O₄ and Fe₂O₃NiO₂ · H₂O) to specify the optimum conditions of immobilization. Removal of H2O2 and the properties of immobilized sets were also investigated. To that end, adsorption and then cross-linking methods onto magnetic particles were performed. The optimum immobilization conditions were found for catalase: immobilization time (15 min for Fe₃O₄; 10 min for Fe2O₃NiO₂ · H₂O), the initial enzyme concentration (1 mg/mL), amount of magnetic particles (25 mg), and glutaraldehyde concentration (3%). The activity reaction conditions (optimum temperature, optimum pH, pH stability, thermal stability, operational stability, and reusability) were characterized. Also kinetic parameters were calculated by Lineweaver-Burk plots. The optimum pH values were found to be 7.0, 7.0, and 8.0 for free enzyme, Fe₃O₄-immobilized catalases, and Fe₂O₃NiO₂ · H₂O-immobilized catalases, respectively. All immobilized catalase systems displayed the optimum temperature between 25 and 35°C. Reusability studies showed that Fe₃O₄-immobilized catalase can be used 11 times with 50% loss in original activity, while Fe2O₃NiO₂ · H₂O-immobilized catalase lost 67% of activity after the same number of uses. Furthermore, immobilized catalase systems exhibited improved thermal and pH stability. The results transparently indicate that it is possible to have binding between enzyme and magnetic nanoparticles.

  18. Optimization of Adsorptive Immobilization of Alcohol Dehydrogenases

    NARCIS (Netherlands)

    Trivedi, Archana; Heinemann, Matthias; Spiess, Antje C.; Daussmann, Thomas; Büchs, Jochen

    2005-01-01

    In this work, a systematic examination of various parameters of adsorptive immobilization of alcohol dehydrogenases (ADHs) on solid support is performed and the impact of these parameters on immobilization efficiency is studied. Depending on the source of the enzymes, these parameters differently in

  19. Microstructural and potential dependence studies of urease-immobilized gold nanoparticles-polypyrrole composite film for urea detection.

    Science.gov (United States)

    Rajesh; Puri, Nidhi; Mishra, Sujeet K; Laskar, Mariam J; Srivastava, Avanish K

    2014-01-01

    Gold nanoparticle-polypyrrole nanocomposite film was electrochemically deposited in a single-step polymerization of pyrrole in the presence of 3-mercaptopropionic acid (MPA)-capped gold nanoparticles (GNPs) and p-toluenesulfonic acid (pTSA) on the surface of an indium tin oxide (ITO)-coated glass plate. The carboxyl functional groups surrounding the GNPs within the polymer matrix were utilized for the immobilization of urease enzyme through carbodiimide coupling reaction for the construction of a Urs/GNP(MPA)-PPy/ITO-glass bioelectrode for urea detection in Tris-HCl buffer. The resulting bioelectrode film was characterized by atomic force microscopy (AFM), high-resolution transmission electron microscopy (HRTEM), contact angle measurement, Fourier transform infrared spectroscopy (FTIR), and electrochemical techniques. The potentiometric response of the bioelectrode made of polymer nanocomposite films of two different thicknesses prepared at 100 and 250 mC cm(-2) charge densities, respectively, was studied towards the urea concentration in Tris-HCl buffer (pH 7.4). The thin polymer nanocomposite film-based bioelectrode prepared at 100 mC cm(-2) charge density exhibited a comparatively good potentiometric response than a thick 250 mC cm(-2) charge density film with a linear range of urea detection from 0.01 to 10 mM with a sensitivity of 29.7 mV per decade.

  20. Screening of lipase inhibitors from Scutellaria baicalensis extract using lipase immobilized on magnetic nanoparticles and study on the inhibitory mechanism.

    Science.gov (United States)

    Wan, Li-Hong; Jiang, Xiao-Lan; Liu, Yi-Ming; Hu, Jin-Jie; Liang, Jian; Liao, Xun

    2016-03-01

    Scutellaria baicalensis is a traditional Chinese medicinal plant possessing a wide variety of biological activities. In this work, lipase immobilized on magnetic nanoparticles (LMNPs) was used as solid phase extract absorbent for screening of lipase inhibitors from this plant. Three flavonoids were found to bind to LMNPs and were identified as baicalin, wogonin, and oroxylin A by liquid chromatography-mass spectrometry (HPLC-MS). Their IC50 values were determined to be 229.22 ± 12.67, 153.71 ± 9.21, and 56.07 ± 4.90 μM, respectively. Fluorescence spectroscopy and molecular docking were used to probe the interactions between these flavonoids and lipase. All the flavonoids quenched the fluorescence of lipase statically by forming new complexes, implying their affinities with the enzyme. The thermodynamic analysis suggested that van der Waals force and hydrogen bond were the main forces between wogonin and lipase, while hydrophobic force was the main force for the other two flavonoids. The results from a molecular docking study further revealed that all of them could insert into the pocket of lipase binding to a couple of amino acid residues.

  1. Study of thioflavin-T immobilized in porous silicon and the effect of different organic vapors on the fluorescence lifetime.

    Science.gov (United States)

    Hutter, Tanya; Amdursky, Nadav; Gepshtein, Rinat; Elliott, Stephen R; Huppert, Dan

    2011-06-21

    Steady-state and time-resolved emission techniques have been employed to study the fluorescence properties of thioflavin-T (ThT) adsorbed on oxidized porous silicon (PSi) surfaces, with an average pore size of ∼10 nm. We found that the average fluorescence decay time of ThT, when it is adsorbed on the PSi surface, is rather long, τ(av) = 1.3 ns. We attribute this relatively long emission lifetime to the effect of the immobilization of ThT on the PSi surface, which inhibit the rotation of the aniline with respect to the benzothiazole moieties of ThT. We also measured the fluorescence properties of ThT in PSi samples in equilibrium with vapors of several liquids, such as methanol, acetonitrile, and water. We found that the fluorescence intensity drops by a factor of 10, and the average decay time, measured by a time-correlated single-photon counting technique, decreases by a factor of 3. We explain these results in terms of liquid condensation of the vapors in the PSi pores, which leads to partial dissolution of the ThT molecules in the liquid pools.

  2. Preparation of Laccase Immobilized Cryogels and Usage for Decolorization

    Directory of Open Access Journals (Sweden)

    Murat Uygun

    2013-01-01

    Full Text Available Poly(methyl methacrylate-co-glycidyl methacrylate (poly(MMA-co-GMA cryogels were synthesized by radical cryopolymerization technique. Then, laccase enzyme was covalently attached to the cryogel and characterized by using swelling studies and SEM and EDX analyses. Kinetic properties and optimum conditions of the immobilized and free laccase were studied and it was found that of the immobilized laccase was lower than that of free laccase. of the immobilized laccase was increased upon immobilization. Optimum pH was found to be 4.0 for each type of laccase, while optimum temperature was shifted to the warmer region after the immobilization. It was also found that thermal stability of the immobilized laccase was higher than that of free laccase. Immobilized laccase could be used for 10 times successive reuse with no significant decrease in its activity. Also, these laccase immobilized cryogels were successfully used for the decolorization of seven different dyes.

  3. Study on Hydrolysis of Lactose in Whey by use of Immobilized Enzyme Technology for Production of Instant Energy Drink

    Directory of Open Access Journals (Sweden)

    Karunakar Singh

    2012-04-01

    Full Text Available The strain Kluyveromyces marxianus was selected to isolate enzyme β-galactosidase, to hydrolyze lactose in whey to prepare instant energy beverage. The cells were immobilized in 5.0% sodium alginate gel for their subsequent use in hydrolysis of lactose in whey. The immobilized cell system was found beneficial in reducing the cost of the product and increase reusability of enzyme. Various process parameters were optimized. Maximum yield of the lactose hydrolysis i.e., 81.2% was found with microbial cells immobilized in 10.0% CaCl2 solution with a bead size of 2.20 mm. The system was stable and beads could be reused up to eighth cycle without any remarkable change in their ability to carry out lactose hydrolysis in whey.

  4. Covalent immobilization of oligoDNA on the surface of magnetic nanoparticles and surface-enhanced Raman scattering study

    Institute of Scientific and Technical Information of China (English)

    SHEN Hebai; WANG Youbao; YANG Haifeng; JIANG Jisen

    2003-01-01

    The DNA magnetic nanoparticles are potentially useful in isolating and purifying DNA or RNA, directing-target-medicines, the development of DNA biosensors and biochips. Surface functionalized magnetic nanoparticles with monodispersed shape and size were prepared by coating nano-sized γ-Fe2O3 with silica in reverse microemulsion, and then thiol-compounds were immobilized onto the magnetic nanoparticles. After immobilizing oligoDNA modified with thiol-disulfide on the surface of the fictionalized magnetic nanoparticles, we obtained DNA-magnetic nanoparticles. The efficiency of the single-linking probes loading at the surfaces of magnetic nanoparticles was examined via hybridization experiment. Surface-enhanced Raman scattering methods were also effectively applied to observing the immobilization and hybridization processes mentioned above. The results demonstrated oligoDNA being availably connected to the surface of the magnetic nanoparticles.

  5. Production of Biodiesel Using Immobilized Lipase and the Characterization of Different Co-Immobilizing Agents and Immobilization Methods

    Directory of Open Access Journals (Sweden)

    Kang Zhao

    2016-08-01

    Full Text Available Lipase from Candida sp. 99–125 is widely employed to catalyzed transesterification and can be used for biodiesel production. In this study, the lipase was immobilized by combined adsorption and entrapment to catalyze biodiesel production from waste cooking oil (WCO via transesterification, and investigating co-immobilizing agents as additives according to the enzyme activity. The addition of the mixed co-immobilizing agents has positive effects on the activities of the immobilized lipase. Three different immobilizing methods were compared by the conversion ratio of biodiesel and structured by Atom Force Microscopy (AFM and Scanning Electron Microscopy (SEM, respectively. It was found that entrapment followed by adsorption was the best method. The effect of the co-immobilizing agent amount, lipase dosage, water content, and reuse ability of the immobilized lipase was investigated. By comparison with previous research, this immobilized lipase showed good reuse ability: the conversion ratio excesses 70% after 10 subsequent reactions, in particular, was better than Novozym435 and TLIM on waste cooking oil for one unit of lipase.

  6. Comparative study of the kinetics and equilibrium of phenol biosorption on immobilized white-rot fungus Phanerochaete chrysosporium from aqueous solution.

    Science.gov (United States)

    Farkas, Viktor; Felinger, Attila; Hegedűsova, Alžbeta; Dékány, Imre; Pernyeszi, Tímea

    2013-03-01

    In this study the kinetics and equilibrium of phenol biosorption were studied from aqueous solution using batch technique at an initial pH of 5.5. The biosorption was studied on Ca-alginate beads, on non-living mycelial pellets of Phanerochaete chrysosporium immobilized on Ca-alginate, and on free fungal biomass. Ph. chrysosporium was grown in a liquid medium containing mineral and vitamin materials with complex composition. The biosorption process followed pseudo second-order kinetics on all bioadsorbents. The bioadsorption-equilibrium on blank Ca-alginate, free and immobilized fungal biomass can be described by Langmuir, anti-Langmuir and Freundlich isotherm models using nonlinear least-squares estimation. Copyright © 2012 Elsevier B.V. All rights reserved.

  7. Ultra-small rhenium nanoparticles immobilized on DNA scaffolds: An excellent material for surface enhanced Raman scattering and catalysis studies.

    Science.gov (United States)

    Anantharaj, S; Sakthikumar, K; Elangovan, Ayyapan; Ravi, G; Karthik, T; Kundu, Subrata

    2016-12-01

    Highly Sensitive and ultra-small Rhenium (Re) metal nanoparticles (NPs) were successfully stabilized in water by the staging and fencing action of the versatile biomolecule DNA that resulted in two distinct aggregated chain-like morphologies with average grain sizes of 1.1±0.1nm and 0.7±0.1nm for the very first time within a minute of reaction time. Re NPs are formed by the borohydride reduction of ammonium perrhenate (NH4ReO4) in the presence of DNA at room temperature (RT) under stirring. The morphologies were controlled by carefully monitoring the molar ratio of NH4ReO4 and DNA. The synthesized material was employed in two potential applications: as a substrate for surface enhanced Raman scattering (SERS) studies and as a catalyst for the reduction of aromatic nitro compounds. SERS study was carried out by taking methylene blue (MB) as the probe and the highest SERS enhancement factor (EF) of 2.07×10(7) was found for the aggregated chain-like having average grain size of 0.7±0.1nm. Catalytic reduction of 4-nitro phenol (4-NP), 2-nitro phenol (2-NP) and 4-nitroaniline (4-NA) with a rate constant value of 6×10(-2)min(-1), 33.83×10(-2)min(-1) and 37.4×10(-2)min(-1) have testified the excellent catalytic performance of our Re NPs immobilized on DNA. The overall study have revealed the capability of DNA in stabilizing the highly reactive Re metal at nanoscale and made them applicable in practice. The present route can also be extended to prepare one dimensional (1-D), self-assembled NPs of other reactive metals, mixed metals or even metal oxides for specific applications in water based solutions.

  8. A model study of artificial linker system using self-assembled calix[4]arene derivative monolayers for protein immobilization

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Minsu; An, Won Gun; Kim, Jae-Ho; Choi, Heung-Jin; Kim, Sung-Hoon; Han, Moon-Hi; Koh, Kwangnak

    2004-01-05

    The attachment of biomolecules, in particular proteins, onto solid supports is fundamental in the development of advanced biosensors, biochips, bioreactors, and many diagnostic techniques. In addition, the effective investigation of biomolecular structure and function with chip-based modern instruments often requires effective attachment of the biomolecule to a substrate. For this reason, it is very important to construct well-characterized linker system that can immobilize protein efficiently. Here, we investigate the formation of self-assembled monolayers (SAMs) with calix[4]arene ethylester and carboxylic acid derivatives that can serve as a model system for protein immobilization at solid surfaces. The calix[4]arene derivative monolayers were formed on Au surface and carefully characterized by atomic force microscopy (AFM), Fourier transform infrared reflection absorption spectroscopy (FTIR-RAS) and surface plasmon resonance (SPR). Immobilization process of protein using bovine serum albumin (BSA) on the artificial linker layer was measured by SPR. The surface concentration of BSA was calculated by simulation of experimental SPR data. The surface concentration of BSA on the carboxylic acid form was higher than that of the ethylester. These results can help in modeling and understanding of protein immobilization on the linker layer.

  9. 壳聚糖固定化琼脂酶的研究%Study on immobilization of agarase by chitosan

    Institute of Scientific and Technical Information of China (English)

    朱启忠; 朱慧文; 孙延娜; 周晓龙; 郝梅; 郭振博; 刘丽丽

    2011-01-01

    Key factors for agarase immobilization on chitosan microspheres were investigated by the orthogonal experimental design. The results showed that the best efficiency of immobilization was obtained by using chitosan when the chitosan was cross linked with 2. 5% glutaraldehyde for 6 h, mixed three volume of free enzyme with one gram of carrier and reacted with agarase for 3 h. The optimum pH and the temperature of the immobilized enzyme were 8. 5 and 50 °C. The immobilized enzyme showed that better stability for pH and the temperature was higher than free enzyme.%采用壳聚糖微球对琼脂酶进行固定化,在单因素实验的基础上用正交试验法确定最佳固定化工艺.结果表明:在戊二醛体积分数为2.5%,交联时间为6h,加酶量为15mL,固定时间为3h时固定酶的活力最高;固定化酶的最适反应温度及最适pH分别为50℃和8.5,高于游离酶;同时其热稳定性及操作稳定性均高于游离酶.

  10. Zinc Oxide Nanoparticles Supported Lipase Immobilization for Biotransformation in Organic Solvents: A Facile Synthesis of Geranyl Acetate, Effect of Operative Variables and Kinetic Study.

    Science.gov (United States)

    Patel, Vrutika; Shah, Chandani; Deshpande, Milind; Madamwar, Datta

    2016-04-01

    The present study describes grafting of zinc oxide (ZnO) nanoparticles with polyethyleneimine (PEI) followed by modification with glutraldehyde used as the bridge for binding the enzyme to support. The prepared nanocomposites were then characterized using Fourier transform infrared spectroscopy, thermogravimetric analysis, and transmission electron microscopy, utilized for synthesis of geranyl acetate in n-hexane. Among all the three prepared nanocomposites (ZnO + PEI, ZnO + PEI + SAA, ZnO + PEI + GLU), Candida rugosa lipase immobilized on ZnO-PEI-GLU was found to be best for higher ester synthesis. The operating conditions that maximized geranyl acetate resulted in the highest yield of 94 % in 6 h, molar ratio of 0.1:0.4 M (geraniol/vinyl acetate) in the presence of n-hexane as reaction medium. Various kinetic parameters such as V max, K i(G), K m(G), and K m(VA) were determined using nonlinear regression analysis for order bi-bi mechanism. The kinetic study showed that reaction followed order bi-bi mechanism with inhibition by geraniol. Activation energy (E a ) was found to be lower for immobilized lipase (12.31 kJ mol(-1)) than crude lipase (19.04 kJ mol(-1)) indicating better catalytic efficiency of immobilized lipase. Immobilized biocatalyst demonstrated 2.23-fold increased catalytic activity than crude lipase and recycled 20 times. The studies revealed in this work showed a promising perspective of using low-cost nanobiocatalysts to overcome the well-known drawbacks of the chemical-catalyzed route.

  11. Study on immobilization and migration of nuclide u in superficial soil of uranium tailings pond

    Science.gov (United States)

    Chang, Zhe; Zhou, Shukui

    2017-05-01

    The uranium tailings in southern China was used as the object of study to study the fixation and migration characteristics of nuclide U in shallow tailings. The results showed that the precipitation of tailings in the tailings soil was not linearly related to the depth during the acid rain leaching process. Tailings soil in the role of fixatives, when the lime as a fixative, the tailings of different soil uranium in 20 days after the re-precipitation. However, when lime and ammonium phosphate were used as fixing agents, the cumulative precipitation of U had a significant effect, and the migration of uranium was inhibited.

  12. Immobilization of cobalt(II) Schiff base complexes on polystyrene resin and a study of their catalytic activity for the aerobic oxidation of alcohols.

    Science.gov (United States)

    Jain, Suman; Reiser, Oliver

    2008-01-01

    The copper-catalyzed [3+2] azide-alkyne cycloaddition and the Staudinger ligation are readily applicable and highly efficient for the immobilization of cobalt Schiff base complexes onto polystyrene resins. Stepwise synthesis of polymer-bound Schiff bases followed by their subsequent complexation with metal ions were successfully carried out. Direct covalent attachment of preformed homogeneous cobalt Schiff base complexes to the resins was also possible. The catalytic efficiency of the so-prepared polystyrene-bound cobalt Schiff bases was studied for the oxidation of alcohols to carbonyl compounds using molecular oxygen as oxidant. The immobilized complexes were highly efficient and even more reactive than the corresponding homogenous analogues, thus affording better yields of oxidized products within shorter reaction times. The supported catalysts could easily be recovered from the reaction mixture by simple filtration and reused for subsequent experiments with consistent catalytic activity.

  13. A comparative study of immobilization techniques for urease on glass-pH-electrode and its application in urea detection in blood serum.

    Science.gov (United States)

    Sahney, Rachana; Anand, S; Puri, B K; Srivastava, A K

    2006-09-25

    Different techniques have been used (physical adsorption, physically entrapped sandwich and microencapsulation) for the immobilization of urease enzyme in tetramethylorthosilicate (TMOS) derived sol-gel matrix on the sensing surface of glass-pH-electrode. No significant leaching of enzyme occurs from the microencapsulated and physically entrapped enzyme sandwich films. Potentiometric techniques have been used for the estimation of urea concentration in each instance. Various parameters of biosensor performance have been studied which indicates that microencapsulation technique is a better method of enzyme immobilization in sol-gel films derived from TMOS. The advantage of microencapsulated biosensor over others include higher sensitivity (dpH/dp(C)=2.4), lower detection limit of 52 microg mL(-1), larger linear range (0.01-30 mM) of urea determination and reasonably long-term stability of about 25 days with 80% response signal.

  14. On the dynamics of immobilized enzyme kinetics in a microreactor: A study of AP-catalyzed reactions

    Directory of Open Access Journals (Sweden)

    Pratap R Patnaik

    2011-11-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} The kinetics of immobilized enzyme-catalyzed reactions in microreactors differ from those in macro-scale reactors. Recognizing this, a recent study (Patnaik 2011 based on a new interpretation of the kinetics of AP-catalyzed reactions showed that dynamic behavior is feasible only certain loci relating key kinetic parameters. That work has been extended here, and the kinetic parameters have now been related to bulk phase concentrations, thereby providing a link with the reaction system per se. It has also been shown that under certain conditions the reaction may become self-quenching but either monotonically or as damped oscillations. These two studies thus establish the importance of understanding kinetic dynamics in microreactors and in selecting feasible operating conditions.

  15. Trichloroethylene aerobic cometabolism by suspended and immobilized butane-growing microbial consortia: a kinetic study.

    Science.gov (United States)

    Frascari, Dario; Zanaroli, Giulio; Bucchi, Giacomo; Rosato, Antonella; Tavanaie, Nasrin; Fraraccio, Serena; Pinelli, Davide; Fava, Fabio

    2013-09-01

    A kinetic study of butane uptake and trichloroethylene (TCE) aerobic cometabolism was conducted by two suspended-cell (15 and 30°C) and two attached-cell (15 and 30°C) consortia obtained from the indigenous biomass of a TCE-contaminated aquifer. The shift from suspended to attached cells resulted in an increase of butane (15 and 30°C) and TCE (15°C) biodegradation rates, and a significant decrease of butane inhibition on TCE biodegradation. The TCE 15°C maximum specific biodegradation rate was equal to 0.011 mg(TCE ) mg(protein)(-1) d(-1) with suspended cells and 0.021 mg(TCE) mg(protein)(-1) d(-1) with attached cells. The type of mutual butane/TCE inhibition depended on temperature and biomass conditions. On the basis of a continuous-flow simulation, a packed-bed PFR inoculated with the 15 or 30°C attached-cell consortium could attain a 99.96% conversion of the studied site's average TCE concentration with a 0.4-0.5-day hydraulic residence time, with a low effect of temperature on the TCE degradation performances.

  16. Pressure ulcers, indentation marks and pain from cervical spine immobilization with extrication collars and headblocks: An observational study.

    Science.gov (United States)

    Ham, Wietske H W; Schoonhoven, Lisette; Schuurmans, Marieke J; Leenen, Luke P H

    2016-09-01

    To describe the occurrence and severity of pressure ulcers, indentation marks and pain from the extrication collar combined with headblocks. Furthermore, the influence of time, injury severity and patient characteristics on the development of pressure ulcers, indentation marks and pain was explored. Observational. Level one trauma centre in the Netherlands. Adult trauma patients admitted to the Emergency Department in an extrication collar combined with headblocks. Between January and December 2013, 342 patients were included. Study outcomes were incidence and severity of pressure ulcers, indentation marks and pain. The following dependent variables were collected: time in the cervical collar and headblocks, Glasgow Coma Scale, Mean Arterial Pressure, haemoglobin, Injury Severity Score, gender, age, and Body Mass Index. 75.4% of the patients developed a category 1 and 2.9% a category 2 pressure ulcer. Indentation marks were observed in 221 (64.6%) patients; 96 (28.1%) had severe indentation marks. Pressure ulcers and indentation marks were observed most frequently at the back, shoulders and chest. 63.2% experienced pain, of which, 38.5% experienced severe pain. Pain was mainly located at the occiput. Female patients experienced significantly more pain (NRS>3) compared to male patients (OR=2.14, 95% CI 1.21-3.80) None of the investigated variables significantly increased the probability of developing PUs or indentation marks. The high incidence of category 1 pressure ulcers and severe indentation marks indicate an increased risk for pressure ulcer development and may well lead to more severe PU lesions. Pain due to the application of the extrication collar and headblocks may lead to undesirable movement (in order to relieve the pressure) or to bias clinical examination of the cervical spine. It is necessary to revise the current practice of cervical spine immobilization. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Pinning of the Contact Line during Evaporation on Heterogeneous Surfaces: Slowdown or Temporary Immobilization? Insights from a Nanoscale Study.

    Science.gov (United States)

    Zhang, Jianguo; Müller-Plathe, Florian; Leroy, Frédéric

    2015-07-14

    The question of the effect of surface heterogeneities on the evaporation of liquid droplets from solid surfaces is addressed through nonequilibrium molecular dynamics simulations. The mechanism behind contact line pinning which is still unclear is discussed in detail on the nanoscale. Model systems with the Lennard-Jones interaction potential were employed to study the evaporation of nanometer-sized cylindrical droplets from a flat surface. The heterogeneity of the surface was modeled through alternating stripes of equal width but two chemical types. The first type leads to a contact angle of 67°, and the other leads to a contact angle of 115°. The stripe width was varied between 2 and 20 liquid-particle diameters. On the surface with the narrowest stripes, evaporation occurred at constant contact angle as if the surface was homogeneous, with a value of the contact angle as predicted by the regular Cassie-Baxter equation. When the width was increased, the contact angle oscillated during evaporation between two boundaries whose values depend on the stripe width. The evaporation behavior was thus found to be a direct signature of the typical size of the surface heterogeneity domains. The contact angle both at equilibrium and during evaporation could be predicted from a local Cassie-Baxter equation in which the surface composition within a distance of seven fluid-particle diameters around the contact line was considered, confirming the local nature of the interactions that drive the wetting behavior of droplets. More importantly, we propose a nanoscale explanation of pinning during evaporation. Pinning should be interpreted as a drastic slowdown of the contact line dynamics rather than a complete immobilization of it during a transition between two contact angle boundaries.

  18. A kinetic study of bitter taste receptor sensing using immobilized porcine taste bud tissues.

    Science.gov (United States)

    Wei, Lihui; Qiao, Lixin; Pang, Guangchang; Xie, Junbo

    2017-06-15

    At present, developing an efficient assay method for truly reflecting the real feelings of gustatory tissues is of great importance. In this study, a novel biosensor was fabricated to investigate the kinetic characteristics of the receptors in taste bud tissues sensing bitter substances for the first time. Porcine taste bud tissues were used as the sensing elements, and the sandwich-type sensing membrane was fixed onto a glassy carbon electrode for assembling the biosensor. With the developed sensor, the response currents induced by sucrose octaacetate, denatonium benzoate, and quercetin stimulating corresponding receptors were determined. The results demonstrated that the interaction between the analyst with their receptors were fitting to hyperbola (R(2)=0.9776, 0.9980 and 0.9601), and the activation constants were 8.748×10(-15)mol/L, 1.429×10(-12)mol/L, 6.613×10(-14)mol/L, respectively. The average number of receptors per cell was calculated as 1.75, 28.58, and 13.23, while the signal amplification factors were 1.08×10(4), 2.89×10(3) and 9.76×10(4). These suggest that the sensor can be used to quantitatively describe the interaction characteristics of cells or tissue receptors with their ligands, the role of cellular signaling cascade, the number of receptors, and the signal transmission pathways. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. An electrochemical quartz crystal impedance study on anti-human immunoglobulin G immobilization in the polymer grown during dopamine oxidation at an Au electrode.

    Science.gov (United States)

    He, Hua; Xie, Qingji; Yao, Shouzhuo

    2005-09-15

    The polymeric film grown during dopamine oxidation at an Au electrode was studied as a novel matrix for immobilizing anti-human immunoglobulin G (IgG) via the electrochemical quartz crystal impedance analysis (EQCIA) method. The growth of the polymeric films at Au electrodes during dopamine oxidation in neutral phosphate buffer (pH 7.4) and the immobilization of anti-human IgG into the polymeric films during their growth have been traced at real time. Lysozyme control experiments suggested that anti-human IgG was electrostatically incorporated into the polymeric film. Also, the porosity of the polymeric films has been discussed by measuring the "wet" and "dry" frequency shifts. Compared with a polypyrrole film immobilized with anti-human IgG, the proposed matrix possessed a larger amount of specific binding sites for human IgG by subsequent immunoreaction tests. The association constant of the anti-human IgG immunoreaction was obtained with satisfactory results.

  20. Study on the immobilization of anti-IgG on Au-colloid modified gold electrode via potentiometric immunosensor, cyclic voltammetry, and electrochemical impedance techniques.

    Science.gov (United States)

    Fu, Yingzi; Yuan, Ruo; Tang, Dianping; Chai, Yaqin; Xu, Lan

    2005-01-15

    The immobilization of anti-IgG on Au-colloid modified gold electrodes has been investigated. A cleaned gold electrode was first immersed in a mercaptoethylamine (AET) solution, and then gold nanoparticles were chemisorbed onto the thiol groups of the mercaptoethylamine. Finally, anti-IgG was adsorbed onto the surface of the gold nanoparticles. Potentiometric immunosensor, cyclic voltammetry, and electrochemical impedance techniques were used to investigate the immobilization of anti-IgG on Au colloids. In the impedance spectroscopic study, an obvious difference of the electron transfer resistance between the Au-colloid modified electrode and the bare gold electrode was observed. The cyclic voltammogram tends to be more irreversible with increased anti-IgG concentration. Using the potentiometric immunosensor, the proposed technique is based on that the specific agglutination of antibody-coated gold nanoparticles, averaging 16 nm in diameter, in the presence of the corresponding antigen causes a potential change that is monitored by a potentiometry. It is found that the developed immunoagglutination assay system is sensitive to the concentration of IgG antigen as low as 12 ng mL(-1). Experimental results showed that the developed technique is in satisfactory agreement with the ELISA method, and that gold nanoparticles can be used as a biocompatible matrix for antibody or antigen immobilization.

  1. Effect of computerized cognitive training with virtual spatial navigation task during bed rest immobilization and recovery on vascular function: A pilot study

    Directory of Open Access Journals (Sweden)

    Goswami N

    2015-02-01

    Full Text Available Nandu Goswami,1 Voyko Kavcic,2 Uros Marusic,3 Bostjan Simunic,3 Andreas Rössler,1 Helmut Hinghofer-Szalkay,1 Rado Pisot3 1Institute of Physiology, Medical University of Graz, Graz, Austria; 2Institute of Gerontology, Wayne State University, Detroit, MI, USA; 3Institute for Kinesiology Research, University of Primorska, Ankaran, Slovenia Abstract: We investigated the effects of bed rest (BR immobilization, with and without computerized cognitive training with virtual spatial navigation task (CCT, on vascular endothelium on older subjects. The effects of 14-day BR immobilization in healthy older males (n=16 of ages 53–65 years on endothelial function were studied using EndoPAT®, a noninvasive and user-independent method. From the group of 16 older men, 8 randomly received CCT during the BR, using virtual navigation tasks in a virtual environment with joystick device. In all the cases, EndoPAT assessments were done at pre- and post-BR immobilization as well as following 28 days of ambulatory recovery. The EndoPAT index increased from 1.53±0.09 (mean ± standard error of the mean at baseline to 1.61±0.16 following immobilization (P=0.62 in the group with CCT. The EndoPAT index decreased from 2.06±0.13 (mean ± standard error of the mean at baseline to 1.70±0.09 at the last day of BR study, day 14 (BR14 (P=0.09 in the control group. Additionally, there were no statistically significant differences between BR14 and at 28 days of follow-up (rehabilitation program (R28. Our results show a trend of immobilization in older persons affecting the vasoconstrictory endothelial response. As the control subjects had a greater increase in EndoPAT index after R28 (+0.018 compared to subjects who had cognitive training (+0.11 (calculated from the first day of BR study, it is possible that cognitive training during BR does not improve endothelial function but rather contributes to slowing down the impairment of endothelial function. Finally, our results

  2. Immobilization of Isolated Lipase From Moldy Copra (Aspergillus Oryzae

    Directory of Open Access Journals (Sweden)

    Seniwati Dali

    2011-01-01

    Full Text Available Enzyme immobilization is a recovery technique that has been studied in several years, using support as a media to help enzyme dissolutions to the reaction substrate. Immobilization method used in this study was adsorption method, using specific lipase from Aspergillus oryzae. Lipase was partially purified from the culture supernatant of Aspergillus oryzae. Enzyme was immobilized by adsorbed on silica gel. Studies on free and immobilized lipase systems for determination of optimum pH, optimum temperature, thermal stability and reusability were carried out. The results showed that free lipase had optimum pH 8,2 and optimum temperature 35 °C while the immobilized lipase had optimum 8,2 and optimum temperature 45 °C. The thermal stability of the immobilized lipase, relative to that of the free lipase, was markedly increased. The immobilized lipase can be reused for at least six times.

  3. Biosorption of Zn+2 on non living biomass of Spirulina platensis immobilized on polyurethane foam cubes: Column studies

    Directory of Open Access Journals (Sweden)

    P Nirguna Babu

    2015-04-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 In the present study, the non living biomass of cyanobacteria Spirulina platensis was used for biosorption of Zn+2 in column mode. Polyurethane foam (PUF cubes were used for immobilizing the biosorbent. A maximum biomass loading of 0.2 g dry S. platensis /(g of PUF cubes could be achieved. The effect of parameters (such as pH of feed solution, flow rate of feed solution to column, bed height and initial concentration of metal ion in feed solution on uptake capacity of biosorbent was studied. A maximum uptake capacity of 87.3 mg Zn+2/(g S. platensis was observed under optimum conditions. The column was regenerated using 0.1 M HCl and sorption-desorption studies were carried out for four cycles. Both  % removal of Zn+2 and uptake capacity of biosorbent were found to progressively decrease with increase in the number of cycles. The biomass was characterized by Fourier transform infrared Spectroscopy (FTIR and Scanning Electronic Microscopic (SEM images before and after biosorption. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

  4. MICROBIAL HYDROLASES IMMOBILIZED ON POROUS MATRICES

    Directory of Open Access Journals (Sweden)

    MONICA DRAGOMIRESCU

    2013-07-01

    Full Text Available Starch degrading enzymes are used as feed additives to increase the digestibility of corn meal based diet in livestock and poultry. To be efficient, these enzymes have to present a good activity and stability. Immobilization by physical bonding of enzymes on a porous support is a simple and efficient method to preserve enzyme molecules in an active form and retain their activity for a period of time. The aim of this study was to stabilize an enzymatic preparation with amylase activity produced by a native strain of Bacillus amyloliquefaciens in submerged culture. The immobilization technique used was physical bonding on a porous ceramic support. The enzymatic preparation with amylase activity was used in immobilization in a liophylized form. By using the same method we immobilized also a purified Aspergillus niger amylase. For both enzymes, the optimal temperature and pH of the native and immobilized enzymes did not vary significantly. At temperature and pH values lower than the optimum, the relative activities have been higher for the immobilized Bacillus amyloliquefaciens enzyme compared to the native one. The immobilization has led to an enzymatic compound with stability at pH 3 and 37°C and in time higher than that of the free one.

  5. Immobilization of Peroxidase onto Magnetite Modified Polyaniline

    Directory of Open Access Journals (Sweden)

    Eduardo Fernandes Barbosa

    2012-01-01

    Full Text Available The present study describes the immobilization of horseradish peroxidase (HRP on magnetite-modified polyaniline (PANImG activated with glutaraldehyde. After the optimization of the methodology, the immobilization of HRP on PANImG produced the same yield (25% obtained for PANIG with an efficiency of 100% (active protein. The optimum pH for immobilization was displaced by the effect of the partition of protons produced in the microenvironment by the magnetite. The tests of repeated use have shown that PANImG-HRP can be used for 13 cycles with maintenance of 50% of the initial activity.

  6. Principles, techniques, and applications of biocatalyst immobilization for industrial application.

    Science.gov (United States)

    Eş, Ismail; Vieira, José Daniel Gonçalves; Amaral, André Corrêa

    2015-03-01

    Immobilization is one of the most effective and powerful tools used in industry, which has been studied and improved since the last century. Various immobilization techniques and support materials have been used on both laboratory and industrial scale. Each immobilization technique is applicable for a specific production mostly depending on the cost and sensibility of process. Compared to free biocatalyst systems, immobilization techniques often offer better stability, increased activity and selectivity, higher resistance, improved separation and purification, reuse of enzymes, and consequently more efficient process. Recently, many reviews have been published about immobilization systems; however, most of them have focused on a specific application or not emphasized in details. This review focuses on most commonly used techniques in industry with many recent applications including using bioreactor systems for industrial production. It is also aimed to emphasize the advantages and disadvantages of the immobilization techniques and how these systems improve process productivity compared to non-immobilized systems.

  7. 脂肪酶固定化及其催化生物柴油研究%Study on Lipase Immobilization and Immobilized Lipase's Application in Synthesis of Biodiesel

    Institute of Scientific and Technical Information of China (English)

    赵兴秀; 何义国; 赵长青; 方春玉; 张静; 邹伟

    2015-01-01

    得到脂肪酶固定化的最佳条件及固定脂肪酶对生物柴油的转化率.利用单因素试验和正交试验确定脂肪酶固定化的最佳条件,通过气相色谱-质谱联用仪分析合成生物柴油的主要成分.结果:脂肪酶固定化的最佳条件:缓冲液pH 7.5、载体/酶液比为25 mg/mL、固定化温度应为40℃,其固定化酶活力为68.25 U/g,利用固定脂肪酶催化合成生物柴油的转化率高达75%.结果表明:固定化酶比游离酶具有更高的催化效率,对高温和pH具有更高的耐受性.固定化脂肪酶催化效率高、操作稳定性较强,具有较好的工业化生产潜力.%It was to get the best conditions of lipase immobilization and the conversion rate of biodiesel production. The optimum conditions of lipase immobilization were obtained by single factor experiment and orthogonal test. The main components of the biodiesel were analyzed by the gas chromatograph-mass spectrometer. The optimum conditions of lipase immobilization were obtained that was the pH of buffer was 7.5 , the ration of vector : enzyme solution was 25 mg : 1 mL, the immobilized temperature was 40 ℃. The immobilized enzyme activity was 68.25 U/g. With immobilized lipase the conversion rate of biodiesel production was up to 75%. The result showed that the immobilized lipase had higher catalytic efficiency and its tolerance was more improved to high-temperature and pH than the free enzyme. The immobilized lipase had a potential for industrial production because of its high catalytic efficiency and strong operational stability.

  8. Hemopoiesis-stimulating activity of immobilized oligonucleotides and hyaluronidase during cytostatic-induced myelosuppression.

    Science.gov (United States)

    Dygai, A M; Skurikhin, E G; Pershina, O V; Zhdanov, V V; Khmelevskaya, A M; Andreeva, T V; Poponina, A M; Zjuzkov, G N; Udut, E V; Khrichkova, T Ju; Simanina, E V; Miroshnichenko, L A; Stavrova, L A; Tchaikovsky, A S; Markova, T S; Gurto, R V; Brjushinina, O S; Slepichev, V A

    2011-03-01

    The hemopoiesis-stimulating effect of combined treatment with immobilized oligonucleotides and hyaluronidase preparations was studied during cytostatic-induced myelosuppression caused by cyclophosphamide administration. Immobilized hyaluronidase was shown to increase the efficiency of correction of changes in the erythroid and granulocytic hemopoietic stems with immobilized oligonucleotides. This potentiation of the effect of immobilized oligonucleotides by immobilized hyaluronidase was related to an increase in functional activity of committed hemopoietic precursors.

  9. 固定化乳酸菌发酵草莓酸奶工艺研究%STUDY ON THE TECHNOLOGY OF STRAWBERRY YOGHURT FERMENTED BY IMMOBILIZED LACTOBACILLUS

    Institute of Scientific and Technical Information of China (English)

    刘进杰; 任玉娜; 屈慧鸽; 张玉香

    2009-01-01

    The technology of strawberry yoghurt fermented by Lactobacillus which were immobilized by sodium alginate were studied. Results showed that the optimum technology condition to ferment strawberry yoghurt by immobilized Lactobacillus is 1.5 % sodium alginate concentration, 6 mL skim milk containing strains/100 mL sodium alginate solution, 100 mL sodium alginate solution/100 mL mixture of strawberry and milk, 2 mm~3 mm bead diameter, incubation temperature 40 ℃, 10 % sugar and 15 % strawberry. And the results of continuous fermentation showed that Lactobacillus immobilized by sodium alginate can be used to ferment strawberry yoghurt for 10 times.%研究用海藻酸钠包埋乳酸菌发酵草莓酸奶工艺.研究结果表明固定化乳酸菌发酵草莓酸奶的最佳工艺条件为:海藻酸钠溶液浓度为1.5%,含菌种脱脂乳用量为6mL/100mL海藻酸钠溶液,胶珠的添加量为100mL海藻酸钠溶液/100 mL草莓奶液,胶珠直径为2 mm~3 mm,培养温度为40℃,白砂糖添加量为10%,草莓浆添加量15%.连续发酵结果表明固定化乳酸菌发酵草莓酸奶可连续使用10次.

  10. Cyclic voltammetry and scanning electrochemical microscopy studies of methylene blue immobilized on the self-assembled monolayer of n-dodecanethiol

    Energy Technology Data Exchange (ETDEWEB)

    Salamifar, Seyed Ehsan [Department of Chemistry, Tarbiat Modares University, P.O. Box 14115-175, Tehran (Iran, Islamic Republic of); Mehrgardi, Masoud Ayatollahi [Department of Chemistry, University of Isfahan, Isfahan (Iran, Islamic Republic of); Kazemi, Sayed Habib [Department of Chemistry, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan (Iran, Islamic Republic of); Mousavi, Mir Fazllollah, E-mail: mousavim@modares.ac.i [Department of Chemistry, Tarbiat Modares University, P.O. Box 14115-175, Tehran (Iran, Islamic Republic of)

    2010-12-30

    Electron transfer (ET) kinetics through n-dodecanethiol (C{sub 12}SH) self-assembled monolayer on gold electrode was studied using cyclic voltammetry (CV), scanning electrochemical microscopy (SECM) and electrochemical impedance spectroscopy (EIS). An SECM model for compensating pinhole contribution, was used to measure the ET kinetics of solution-phase probes of ferrocyanide/ferricyanide (Fe(CN){sub 6}{sup 4-/3-}) and ferrocenemethanol/ferrociniummethanol (FMC{sup 0/+}) through the C{sub 12}SH monolayer yielding standard tunneling rate constant (k{sub ET}{sup 0}) of (4 {+-} 1) x 10{sup -11} and (3 {+-} 1) x 10{sup -10} cm s{sup -1} for Fe(CN){sub 6}{sup 4-/3-} and FMC{sup 0/+} respectively. Decay tunneling constants ({beta}) of 0.97 and 0.96 A{sup -1} for saturated alkane thiol chains were obtained using Fe(CN){sub 6}{sup 4-} and FMC respectively. Also, it was found that methylene blue (MB) molecules are effectively immobilized on the C{sub 12}SH monolayer and can mediate the ET between the solution-phase probes and underlying gold substrate. SECM-mediated model was used to simultaneously measure the bimolecular ET between the solution-phase probes and the monolayer-immobilized MB molecules, as well as tunneling ET between the monolayer-immobilized MB molecules and the underlying gold electrode, allowing the measurement of k{sub BI} = (5 {+-} 1) x 10{sup 6} and (4 {+-} 2) x 10{sup 7} cm{sup 3} mol{sup -1} s{sup -1} for the bimolecular ET and k{sub ET/MB}{sup 0}=(1{+-}0.3)x10{sup -3} and (7 {+-} 3) x 10{sup -2} s{sup -1} for the standard tunneling rate constant of ET using Fe(CN){sub 6}{sup 4-/3-} and FMC{sup 0/+} probes respectively.

  11. Study on the paper cellulose immobilized papain and its exploration%纸纤维固定木瓜蛋白酶的研究及应用

    Institute of Scientific and Technical Information of China (English)

    易喻; 李慧娟; 陈建澍; 梅建凤; 朱克寅; 应国清

    2013-01-01

    To use paper cellulose as a carrier, immobilization of papain on paper cellulose was studied. Thus, papain was immobilized onto glutaraldehyde-activated paper cellulose under acid conditions. The enzymatic properties, such as proteolytic activity, heat-stability, glutaraldehyde volume fraction, enzyme amount and pH-activity profile, of the immobilized papain preparation were examined. The immobilization conditions were optimized by orthogonal experiments. The prepared products were applied to digest anti-HCG to obtain F(ab )2 fragments. The results indicated that the immobilized enzyme has an high activity at 40 ℃ when the pH of the buffer solution is 5. 0 as well as with the glutaraldehyde volume fraction is 0. 01%. Besides the enzyme concentration is 46 mg/g. The activity of the products can reach up to 19 250 U/g which are ten times higher than those came from the processes not optimized. The preparation and characterization of the F(ab')2 fragments of anti-HCG are presented in detail. The monoclonal antibody was digested with immobilized papain to produce antibody fragment. The F(ab')2 fragments were then purified by using DEAE-FF size exclusion chromatography. The F(ab')2 fragment(110 KDa) maintained potent suppressive activity and the titer can reaches 1:12 000.%利用纸纤维为载体,制备高活性的固定化木瓜蛋白酶并应用于抗HCG抗体的水解.利用戊二醛交联法,制备固定化木瓜蛋白酶,并通过一系列优化,得到最佳固定化条件,包括pH、给酶量、温度、戊二醛体积分数,将制备的固定化木瓜蛋白酶应用于抗HCG抗体水解并制备F(ab')2片段.研究表明:反应温度为40℃时,固定化酶在pH5.0,0.01 mol/L的醋酸缓冲液条件下,给酶量为46 mg/g载体,戊二醛体积分数为0.01%时,固定化酶的酶活达到最高19 250 U/g,相对于优化前1 940 U/g提高了近10倍,成功应用于抗HCG抗体水解制备F(ab')2片段:经SDS-PAGE电泳检测,F(ab’)2片段达到电泳

  12. Equilibrium isotherm and kinetic studies for the simultaneous removal of phenol and cyanide by use of S. odorifera (MTCC 5700) immobilized on coconut shell activated carbon

    Science.gov (United States)

    Singh, Neetu; Balomajumder, Chandrajit

    2016-09-01

    In this study, simultaneous removal of phenol and cyanide by a microorganism S. odorifera (MTCC 5700) immobilized onto coconut shell activated carbon surface (CSAC) was studied in batch reactor from mono and binary component aqueous solution. Activated carbon was derived from coconut shell by chemical activation method. Ferric chloride (Fecl3), used as surface modification agents was applied to biomass. Optimum biosorption conditions were obtained as a function of biosorbent dosage, pH, temperature, contact time and initial phenol and cyanide concentration. To define the equilibrium isotherms, experimental data were analyzed by five mono component isotherm and six binary component isotherm models. The higher uptake capacity of phenol and cyanide onto CSAC biosorbent surface was 450.02 and 2.58 mg/g, respectively. Nonlinear regression analysis was used for determining the best fit model on the basis of error functions and also for calculating the parameters involved in kinetic and isotherm models. The kinetic study results revealed that Fractal-like mixed first second order model and Brouser-Weron-Sototlongo models for phenol and cyanide were capable to offer accurate explanation of biosorption kinetic. According to the experimental data results, CSAC with immobilization of bacterium S. odorifera (MTCC 5700) seems to be an alternative and effective biosorbent for the elimination of phenol and cyanide from binary component aqueous solution.

  13. Immobilized enzymes in organic synthesis.

    Science.gov (United States)

    Mosbach, K

    1985-01-01

    The immobilization of enzymes and cells by different methods and the possible stabilization of immobilized preparations are discussed. An outlook on 'second generation enzyme technology', which involves immobilized multi-enzyme systems and coenzymes, is given with examples: the immobilization of dehydrogenases with their active sites facing one another, and systems containing NAD(H) coenzymes immobilized by coupling to dextran (in an enzyme electrode), to polyethylene glycol (in a membrane reactor), or to enzymes themselves. The use of immobilized enzymes to synthesize peptides and disaccharides is described.

  14. Study on the influential factors of immobilized microorganisms biodegrading off%固定化微生物降解石油的影响因素研究

    Institute of Scientific and Technical Information of China (English)

    张秀霞; 徐娜娜; 秦丽姣; 白雪晶; 刘永博; 孔甜甜

    2011-01-01

    The present paper is intended to study the effect of immobilized microorganism with natural organic materials taken as the carrier biodegrading oil. Since natural organic material can be used economically and effectively for exploiting the ways for waste treating and natural resource reuse, it is likely to immobilize microorganisms for their application to the bioremediation of oil pollutants in soil and sewage. So far as we know, research has been going on with the high-efficiency oil-degrading single-strain SM - 1 and mixed strain MM - 7 screened and domesticatted in lab-scale as experimental strains. And it is also known that embedding method and adsorption method are most commonly used among the most favorable ones. In addition, experiments have also been done with the natural organic materials YJ - 07 or YJ - 05 as carrier to obtain immobilized microorganism through adsorption so as to find how the environmental factors influence the microorganisms' degradation ability. In addition, work has been done in hoping to discover the influence of different environmental factors including pH, initial oil concentration, the inoculation quantity and salinity on the oil degradation rate both of free and immobilized oil-degrading strains. The results of our studies indicate that the oil degradation rate of immobilized strain MM - 7 ( YJ - 07) can be made to reach 59.6% , which was 2.3 times higher than immobilized Strain MM - 7 ( YJ - 05 ) . The effect of the immobilized strain on the oil degradation proves to be better than the free strain, with the oil degradation rate being higher than the free strain by 10% -43% .Moreover, the immobilized strain proves to have more tolerance for changing the environmental factors and enjoy higher oil degradation rate in a wider environmental changing range. The suitable conditions of each free and immobilized strain proves that their pH value turns to be 7 - 8, their salinity was 5-7 g/L, the initial oil concentration was 1-7 g/L, and

  15. MICROBIAL HYDROLASES IMMOBILIZED ON POROUS MATRICES

    Directory of Open Access Journals (Sweden)

    MONICA DRAGOMIRESCU

    2009-05-01

    Full Text Available Starch degrading enzymes are used as feed additives to increase the digestibility of corn meal based dietin livestock and poultry. To be efficient, these enzymes have to present a good activity and stability.Immobilization by physical bonding of enzymes on a porous support is a simple and efficient method topreserve enzyme molecules in an active form and retain their activity for a period of time.The aim of this study was to stabilize an enzymatic preparation with amylase activity produced by a nativestrain of Bacillus amyloliquefaciens in submerged culture. The immobilization technique used wasphysical bonding on a porous ceramic support. The enzymatic preparation with amylase activity was usedin immobilization in a liophylized form. By using the same method we immobilized also a purifiedAspergillus niger amylase. For both enzymes, the optimal temperature and pH of the native andimmobilized enzymes did not vary significantly. At temperature and pH values lower than the optimum,the relative activities have been higher for the immobilized Bacillus amyloliquefaciens enzyme comparedto the native one. The immobilization has led to an enzymatic compound with stability at pH 3 and 37°Cand in time higher than that of the free one.

  16. Biotechnological production of vanillin using immobilized enzymes.

    Science.gov (United States)

    Furuya, Toshiki; Kuroiwa, Mari; Kino, Kuniki

    2017-02-10

    Vanillin is an important and popular plant flavor, but the amount of this compound available from plant sources is very limited. Biotechnological methods have high potential for vanillin production as an alternative to extraction from plant sources. Here, we report a new approach using immobilized enzymes for the production of vanillin. The recently discovered oxygenase Cso2 has coenzyme-independent catalytic activity for the conversion of isoeugenol and 4-vinylguaiacol to vanillin. Immobilization of Cso2 on Sepabeads EC-EA anion-exchange carrier conferred enhanced operational stability enabling repetitive use. This immobilized Cso2 catalyst allowed 6.8mg yield of vanillin from isoeugenol through ten reaction cycles at a 1mL scale. The coenzyme-independent decarboxylase Fdc, which has catalytic activity for the conversion of ferulic acid to 4-vinylguaiacol, was also immobilized on Sepabeads EC-EA. We demonstrated that the immobilized Fdc and Cso2 enabled the cascade synthesis of vanillin from ferulic acid via 4-vinylguaiacol with repetitive use of the catalysts. This study is the first example of biotechnological production of vanillin using immobilized enzymes, a process that provides new possibilities for vanillin production.

  17. Study on the Enhancement of Immobilized Chlorella Balls' Performance%固定化藻球的强化研究

    Institute of Scientific and Technical Information of China (English)

    严清; 冯国忠

    2011-01-01

    To solve the problems that chlorella balls loose their integrity and algae cells leach easily in the wastewater with phosphate, 1% of activated carbon was added into the balls and then hardened by marinating in CaCl2 solution. The results showed that adding activated carbon could improve the performance of immobilized chlorella balls, and the optimal adding amount of activated carbon was 1 percent of alginate sodium. Hardening could enhance the ability of immobilized chlorella balls in removing NH4+-N and PO43--P from waste water and improve the density of chlorella in ball. The removal efficiency of hardened chlorella balls of NH4+-N and PO43-P were above 80% and 96% respectively.%为解决褐藻胶球在含磷污水中结构易疏松、小球藻易泄漏及胶球易破碎的问题,进行了添加质量分数为1%的活性炭和CaCl2溶液浸泡固定化藻球的加固强化的试验.结果表明,采用添加活性炭的方法可以很好地改进固定化小球的性能,其最佳的添加量为海藻酸钠凝胶的1%;加固胶球系统对氨氮(NH4+-N)的去除率持续增加,最高可增至80%左右;对正磷酸盐(PO43--P)也有较好地去除效果,去除率可达96%以上:胶球经过加固后,胶球内藻细胞密度得到较大提高,固定化性能得到改善.

  18. Ultra-low field T1 vs. T1rho at 3T and 7T: study of rotationally immobilized protein gels and animal brain tissues

    Science.gov (United States)

    Dong, Hui; Inglis, Ben; Barr, Ian; Clarke, John

    2015-03-01

    Clinical magnetic resonance imaging (MRI) machines operating in static fields of typically 1.5 T or 3 T can capture information on slow molecular dynamics utilizing the so-called T1rho technique. This technique, in which a radiofrequency (RF) spin-lock field is applied with microtesla amplitude, has been used, for example, to determine the onset time of stroke in studies on rats. The long RF pulse, however, may exceed the specific absorption rate (SAR) limit, putting subjects at risk. Ultra-low-field (ULF) MRI, based on Superconducting Quantum Interference Devices (SQUIDs), directly detects proton signals at a static magnetic field of typically 50-250 μT. Using our ULF MRI system with adjustable static field of typically 55 to 240 μT, we systematically measured the T1 and T2 dispersion profiles of rotationally immobilized protein gels (bovine serum albumin), ex vivo pig brains, and ex vivo rat brains with induced stroke. Comparing the ULF results with T1rho dispersion obtained at 3 T and 7 T, we find that the degree of protein immobilization determines the frequency-dependence of both T1 and T1rho. Furthermore, T1rho and ULF T1 show similar results for stroke, suggesting that ULF MRI may be used to image traumatic brain injury with negligible SAR. This research was supported by the Henry H. Wheeler, Jr. Brain Imaging Center and the Donaldson Trust.

  19. Evaluation of laboratory and industrial meat and bone meal combustion residue as cadmium immobilizing material for remediation of polluted aqueous solutions: "chemical and ecotoxicological studies".

    Science.gov (United States)

    Coutand, M; Deydier, E; Cyr, M; Mouchet, F; Gauthier, L; Guilet, R; Savaete, L Bernues; Cren, S; Clastres, P

    2009-07-30

    Meat and Bone Meals (MBM) combustion residues (ashes) are calcium and phosphate-rich materials. The aim of this work is to evaluate ashes efficiency for remediation of cadmium-contaminated aqueous solutions, and to assess the bioavailability of cadmium on Xenopus laevis larvae. In this study both industrial (MBM-BA) and laboratory (MBM-LA) ashes are compared regarding their efficiency. Kinetic investigations reveal that cadmium ions are quickly immobilized, with a maximum cadmium uptake at 57 mg Cd(2+)/g of ashes for MBM-LA, two times higher than metal uptake quantity of MBM-BA, in our experimental conditions. Chemical and X-ray diffraction analysis (XRD) reveal that Cd(2+) is mainly immobilized as Ca(10-x)Cd(x)(PO(4))(6)(OH)(2) by both ashes, whereas otavite, Cd(CO(3)), is also involved for MBM-LA in cadmium uptake. Otavite formation could be explained by the presence of carbonates in MBM-LA, as observed by IR. Genotoxicity of cadmium solution on Xenopus larvae is observed at 0.02, 0.2 and 2mg Cd(2+)/L. However addition of only 0.1g/L MBM-LA inhibits these effects for the above concentration values whereas Cd(2+) bioaccumulation in larvae's liver is similar for both experiments, with and without ashes.

  20. [Effect of eleutherococcus on hemostasis in immobilized rats].

    Science.gov (United States)

    Shakhmatov, I I; Bondarchuk, Iu A; Vdovin, V M; Alekseeva, O V; Kiselev, V I

    2007-01-01

    The influence of a chronic (30 days) administration of an eleutherococcus extract on the haemostatic system state was studied in immobilized rats. A 3-h immobilization of untreated animals is accompanied by hypercoagulation and thrombinemia signs on the background of downregulation of the anticoagulant and fibrinolytic activity, which leads to a risk of thrombosis. Preliminary 30-day course of eleutherococcus uptake prevents the immobilization-induced thrombosis in rats.

  1. Motor cortical adaptations to 2 weeks of lower limb immobilization

    DEFF Research Database (Denmark)

    Jensen, Jesper Lundbye; Christensen, Mark Schram; Petersen, Tue Hvass

    It is well established that motor experience is associated with structural and functional plasticity within the central nervous system. It is less well investigated to which extent disuse relating to immobilization is also associated with plastic neuronal changes. The objective of this study was ...... following immobilization. Two weeks after cast removal virtually all measurements returned to preimmobilization levels.In conclusion 2 weeks of lower limb immobilization induces reversible adaptive changes in the motor cortex....

  2. Decolorization of reactive Brilliant Blue KN-R by immobilized cells of Aspergillus ficuum

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Aspergillus ficuum was immobilized with sodium alginate, and decolorization of Reactive Brilliant Blue KN-R was studied on immobilized and free Aspergillus ficuum. The optimal preparation condition of the strain immobilization was obtained by the orthogonal test, it is sodium alginate 3%, CaCl2 5%, wet mycelia 30 g/L, calcific time 8 h. It was found that the immobilized cells could effectively decolorize Reactive Brilliant Blue KN-R, the optimum temperature and pH were 33℃ and 5.0, respectively. The kinetics study of decolorization of immobilized cells showed that the decolorization of Aspergillus ficuum immobilized conformed to zero-order reaction model. The decolorization efficiency of immobilized cell compared with that of free cell in different physical conditions. Results showed that the decolorization of immobilized cells with mycelia had the best efficiency. The immobilized cells could be reused after the first decolorization.

  3. 双醛氧化纤维素固定化木瓜蛋白酶及酶学性质的研究%Study on the immobilization of papain by dialdehyde oxycellulose and enzymatic properties

    Institute of Scientific and Technical Information of China (English)

    郭庆启; 张娜; 南雪; 方桂珍

    2012-01-01

    以双醛氧化纤维素为载体固定化木瓜蛋白酶,研究了固定化酶的制备条件、微观结构及酶学性质。结果表明:固定化时间4h,固定化温度4℃,酶/载体=1:3000(g:g)时,固定化酶的活力最高为50.9U/g。红外光谱和扫描电镜对固定化酶的微观结构研究表明,双醛氧化纤维素的醛基与木瓜蛋白酶的氨基发生共价反应形成固定化酶。与游离酶相比,木瓜蛋白酶经过固定化后,热稳定性和耐酸性增强,与底物酪蛋白的亲和力降低,固定化酶重复使用5次后,相对酶活力为55.1%。%Dialdehyde oxycellulose was prepared as the carrier to immobilize papain. The preparation conditions, microstructure and enzymatic properties of the immobilized enzyme were studied. The results showed that the maximum activity of immobilized papain was 50.9U/g under the optimal immobilization conditions=immobilization time 4h,4℃ and 1:3000 enzyme/carrier ratio (w/w). The microstructure of immobilized enzyme,which was studied by infrared spectrum and scanning electron microscope analysis,showed that the aldehyde group of dialdehyde oxycellulose could react with the amino group of the papain to form immobilized enzyme. Compared with free enzyme,the heat stability and acid resistance of immobilized papain were increased~the affinity with substance casein of dialdehyde oxycellulose immobilized papain was decreased. After being reused five times,the relative enzyme activity was 55.1%.

  4. Bacillus thuringiensis HCB6 Amylase Immobilization by Chitosan Beads

    Science.gov (United States)

    Zusfahair; Ningsih, D. R.; Kartika, D.; Fatoni, A.; Zuliana, A. L.

    2017-02-01

    The purpose of this study was to optimize the amylase immobilization using a chitosan bead and to characterize immobilized amylase of Bacillus thuringiensis Bacteria HCB6. This study was started of amylase production, continued by immobilization optimization including ratio of chitosan:enzymes, enzyme-matrix contact time, substrate concentration, pH effect, incubation temperature effect, reaction time, and stability of immobilized enzyme. Amylase activity assay was dinitro salicylic (DNS) method. The results showed the optimum chitosan:enzyme ratio was 2.5: 1 (v/v), immobilization contact time of 18 hours and immobilization efficiency of 87.93%. Furthermore, immobilized amylase of B. thuringiensis HCB6 showed optimum substrate concentration of 1.5%, optimum pH of 6, optimum incubation temperature of 37 ° C, and the reaction time of 30 minutes. The Michaelis-Menten constant KM value for free and immobilized amylase were 5.30% and 1.33% respectively. Immobilized amylase can be used up to five times with the remaining activity of 43.3%.

  5. Comparative studies of the stability of free and immobilized inulinase from Kluyveromyces marxianus NRRL Y-7571 in aqueous-organic solutions

    Directory of Open Access Journals (Sweden)

    F. V. A. Risso

    2010-12-01

    Full Text Available Enzymes have been extensively used in organic solvents to catalyze a variety of reactions of biological and industrial significance. In this work, the characteristics of free and immobilized inulinase were investigated in buffered solutions of butyl acetate. The influences of the organic solvent content on the optimal temperature and pH, the stabilities to temperature and pH and the kinetic parameters were systematically evaluated. The results showed that the organic solvent content had no effect on the optimal pH, either in the free or immobilized inulinase. For the immobilized enzyme, the optimal temperatures ranged from 55ºC to 60ºC, depending on the content of butyl acetate. At higher butyl acetate content, the stability of the immobilized enzyme increased for both pH and temperature. The organic solvent showed the tendency to increase the values of the kinetic parameters Km and v max for both free and immobilized inulinase.

  6. Study on Mimetic Peroxidase and Molecular Recognition of Phenols With Inclusion Complex of *Ironporphyrin Immobilized by β-CD Polymer

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    β-Cyclodextrin (β-CD) and its cross-linke d polymer (β-CDP) were known as the mimetic models.Metalloporphyrin had been widely used in the enzymatic method of analysis and molecular recognition. In present work, it was investigation that supramolecular recognition for halogenated phenols, three cresols,three nitrophenols and three aminophenols, served respectively as the substrate of the mimetic receptor,iron-5,10,15,20-tetrakis (sulforphenyl)-21H, 23H-porphine (FeTPPS) or FeTPPS-ββ-CDP. Supramolecular complex, FeTPPS-β-CDP with tunction of mult i-recognition and induced-fit, was a advanced kind of mimetic peroxidase; Methyl phenol or polyphenol was the substitute of chlorophenic acid, while aminophenols and other phenols were suggested not to be utilized to enzymatic assay of H2O2. Being a mimetic enzyme mimicking the space structure of overall proteinase, beaimed by immobilized mimetic enzyme with a large number of β-CD interior cavities, chlorophenol was identified optimal substrate in the system tested.

  7. Effect of laser radiation on multi-wall carbon nanotubes: study of shell structure and immobilization process

    Energy Technology Data Exchange (ETDEWEB)

    Gyoergy, Enikoe, E-mail: egyorgy@icmab.es; Perez del Pino, Angel [Instituto de Ciencia de Materiales de Barcelona, Consejo Superior de Investigaciones Cientificas (ICMAB-CSIC) (Spain); Roqueta, Jaume; Ballesteros, Belen [Centro de Investigaciones en Nanociencia y Nanotecnologia, Consejo Superior de Investigaciones Cientificas (CIN2-CSIC) (Spain); Cabana, Laura; Tobias, Gerard [Instituto de Ciencia de Materiales de Barcelona, Consejo Superior de Investigaciones Cientificas (ICMAB-CSIC) (Spain)

    2013-08-15

    Multi-wall carbon nanotubes (MWCNTs) with diameters between 10 and 15 nm were transferred and immobilized onto SiO{sub 2} glass substrates by ultraviolet matrix assisted pulsed laser evaporation (UV-MAPLE). Toluene was chosen as solvent material for the preparation of the composite MAPLE targets. An UV KrF* ({lambda} = 248 nm, {tau}{sub FWHM} {approx_equal} 25 ns, {nu} = 10 Hz) excimer laser source was used for the irradiation experiments. The effects of incident laser fluence on the structure of the laser transferred MWCNTs was investigated by high resolution transmission electron microscopy and Raman spectroscopy. The surface morphology of the laser processed MWCNTs was investigated by field emission scanning electron microscopy and atomic force microscopy in acoustic (dynamic) configuration. Network-like structures constituted by individual nanotubes and nanotube bundles were created onto solid substrates. Changes in the nanotubes' shell structure can be induced through the tuning of the laser fluence value incident onto the composite MAPLE targets.

  8. Study and application of the immobilized penicillin acylase reactor%固定化青霉素酰化酶反应器的研制和应用

    Institute of Scientific and Technical Information of China (English)

    朱彦民; 刘晓军; 张今; 祁振海; 关一鸣; 黄宇红

    2004-01-01

    Objective To study on and use a new 200-liter stainless steel immobilized penicillin acylase (IPA) reactor in a pilot plant.Methods Against the reactor's wall,three columns were installed,in each of which 1.5 kg of wet fiberized IPA with 762 IU·g-1 of activity calculated on wet basis was charged.Dissolved 12 kg of penicillin G potassium (PenGK)was dissolved in a HBO3-NaBO3 buffer solution to make the concentration of the solution to 80g·L-1.Then PenGK was split to 6-APA for a period of the fixed time 90 min.Results The residual activities of IPA were 685 IU·g-1 on wet after 15 batches.The yield of 6-APA reached 89.8% on an average.Conclusions The usage of the new immobilized penicillin acylase reactor in the 6-APA production will result in a higher yield of 6-APA and lower loss of immobilized penicillin acylase.%目的研制一个全新的200 L不锈钢固定化青霉素酰化酶反应器并在中试中应用.方法在罐内壁上安装三个盛酶柱,每根酶柱装入湿纤维状固定化酶1.5 kg,酶活力762 IUg-1 (以湿品为基础计算).以HBO3作缓冲液,底物青霉素G钾的质量浓度为80 g·L-1.每批投料12 kg,每批裂解反应90 min.结果 15批之后,剩余酶活力685 IU*g-1(以湿品为基础计算),6-APA收率平均达89.8%.结论 6-APA生产中使用新的固定化青霉素酰化酶反应器将提高6-APA的收率,减少固定化青霉素酰化酶的损耗.

  9. 棉织物上SESA活化法固定化脂肪酶工艺的研究*%Study on immobilization of lipase onto cotton fiber activated by SESA

    Institute of Scientific and Technical Information of China (English)

    彭立凤; 刘新喜

    2001-01-01

    研究了对-β-硫酸酯乙砜基苯胺活化法在棉织物上固定化脂肪酶的工艺条件,并考察了固定化酶的最适作用温度和pH及间歇操作稳定性。最佳固定化条件为:醚化pH为10.0,偶联pH为7.0,脂肪酶的浓度为6 mg/ml,偶联时间为12h,所得固定化脂肪酶的最大活力为35U/g(棉)·min。固定化酶的最适作用温度为35℃,最适pH为8.0,半衰期为6d。%The conditions of the lipase immobilization onto cotton fiber activated by p-β-sulfuric acid ester ethyl sulfone aniline (SESA) have been studied. The optimal temperature and pH of the immobilized lipase were investigated, and the operating stability of the immobilized lipase was studied too. The results showed that the optimal conditions for the immobilization were that the pH of the reaction for the cotton fiber with SESA was 10.0,the linking pH of lipase to fiber was 7.0,the linking time was 12h,and the concentration of lipase was 6mg· mL- 1 .Then 35 U· g(fiber) - 1 · min- 1 activity of immobilized lipase was obtained. The optimal temperature and pH of the immobilized lipase were 35 ℃ and 8.0 respectively, and its half life was 6 days .

  10. Excess Weapons Plutonium Immobilization in Russia

    Energy Technology Data Exchange (ETDEWEB)

    Jardine, L.; Borisov, G.B.

    2000-04-15

    The joint goal of the Russian work is to establish a full-scale plutonium immobilization facility at a Russian industrial site by 2005. To achieve this requires that the necessary engineering and technical basis be developed in these Russian projects and the needed Russian approvals be obtained to conduct industrial-scale immobilization of plutonium-containing materials at a Russian industrial site by the 2005 date. This meeting and future work will provide the basis for joint decisions. Supporting R&D projects are being carried out at Russian Institutes that directly support the technical needs of Russian industrial sites to immobilize plutonium-containing materials. Special R&D on plutonium materials is also being carried out to support excess weapons disposition in Russia and the US, including nonproliferation studies of plutonium recovery from immobilization forms and accelerated radiation damage studies of the US-specified plutonium ceramic for immobilizing plutonium. This intriguing and extraordinary cooperation on certain aspects of the weapons plutonium problem is now progressing well and much work with plutonium has been completed in the past two years. Because much excellent and unique scientific and engineering technical work has now been completed in Russia in many aspects of plutonium immobilization, this meeting in St. Petersburg was both timely and necessary to summarize, review, and discuss these efforts among those who performed the actual work. The results of this meeting will help the US and Russia jointly define the future direction of the Russian plutonium immobilization program, and make it an even stronger and more integrated Russian program. The two objectives for the meeting were to: (1) Bring together the Russian organizations, experts, and managers performing the work into one place for four days to review and discuss their work with each other; and (2) Publish a meeting summary and a proceedings to compile reports of all the excellent

  11. Immobilized Cell Research

    Science.gov (United States)

    1990-10-31

    beads, the plasmid is twice as stable as in cells In a process where immobilized cells produce material grown in continuous culture over 200...carrageenan) or chemically cross-linked, or- Penicillium chrysogenum than in washed freely suspended ganic polymer (Ca-alginate, polyacrylamide, and mycelium ...these materials are formed into the freely suspended cells stopped after 6 days. If the beads of several millimeters in diameter by allowing the

  12. Study on sodium alginate-chitosan immobilization of stem bromelain%海藻酸钠-壳聚糖共固定化菠萝茎蛋白酶的研究

    Institute of Scientific and Technical Information of China (English)

    高尚欣; 周冰如; 周锦丝; 李燕菲; 赵力超

    2011-01-01

    以海藻酸钠、壳聚糖为材料共固定化菠萝茎蛋白酶,并对固定化条件以及固定化酶的酶学特性进行了研究.通过单因素及正交实验确定固定化酶的最佳条件为:酶用量0.mg/g、海藻酸钠浓度3.0%、壳聚糖浓度1.0%、CaCl浓度5.5%、固化时间90min.固定化后的酶重复使用4次后,相对酶活力仍保留80%以上,固化效果较好.同时,固定化酶最适反应温度和热稳定性提高,反应pH向碱性偏移,酶学特性得到了改善.%Sodium alginate and chitosan materials were fixed to the stem bromelain, and the immobilization conditions and characteristics of immobilized stem bromelain were studied.Through single factor and orthogonal experiment,the best conditions for immobilized stem bromelain were determined as follow: enzyme dosage of 0.4mg/g,3.0% sodium alginate concentration, chitosan concentration of 1.0%, CaCl2 concentration of 5.5%,immobilized time of 90min. The relative activity of immobilized stem bromelain after repeated use four times remained above 80%. Meanwhile, the optimal pH shifted to alkalescence, the immobilized enzyme optimal temperature,thermal stability and enzymatic characteristics had been improved.

  13. Maltodextrin hydrolysis with glucoamylase immobilized in polyacrylamide gel

    Energy Technology Data Exchange (ETDEWEB)

    Yankov, D.; Peeva, L.; Beschkov, V. (Inst. of Chemical Engineering, Bulgarian Academy of Sciences, Sofia (Bulgaria))

    1992-08-01

    The immobilization of glucoamylase by entrapping in a polyacrylamide gel has been studied. The optimum values of pH and temperature for the immobilized enzyme have been determinated. The influence of worked off cycles, substrate concentration and initial degree of hydrolysis on the final conversion of starch have been investigated. (orig.).

  14. Fiber optic biosensor of immobilized firefly luciferase

    Institute of Scientific and Technical Information of China (English)

    蔡谨; 吉鑫松; 等

    2002-01-01

    Luciferase from firefly lantern extract was immobilized on CNBr-activated Sepharose 4B,The kinetic properties of immobilized luciferase were extensively studied.The Km' for D-luciferin is 11.9umol/L,the optimum pH and temperature for Sepharose-bound enzyme were 7.8 and 25℃ respectively.A luminescence fiber optic biosensor,making use of immobilized crude luciferase was developed for assay of ATP.The peak light intensity was linear with respect to ATP concentration in range of 10-9-10-5mol/L.A biological application was also demonstrated with the determination of serum ATP from rats bred in low versus normal oxygen environments.

  15. Fiber optic biosensor of immobilized firefly luciferase

    Institute of Scientific and Technical Information of China (English)

    蔡谨; 孟文芳; 吉鑫松

    2002-01-01

    Luciferase from firefly lantern extract was immobilized on CNBr-activated Sepharose 4B. The kinetic properties of immobilized luciferase were extensively studied. The Km′ for D-luciferin is 11.9 μmol/L, the optimum pH and temperature for Sepharose-bound enzyme were 7.8 and 25℃ respectively. A luminescence fiber optic biosensor, making use of immobilized crude luciferase, was developed for assay of ATP. The peak light intensity was linear with respect to ATP concentration in range of 10-9-10-5 mol/L. A biological application was also demonstrated with the determination of serum ATP from rats bred in low versus normal oxygen environments.

  16. STUDY ON THE IMMOBILIZATION OF PAPAIN WITH A MACROPOROUS BEAD CARRIER OF COPOLYMER CONTAINING MONOMER UNITS OF N-AMINOETHYL ACRYLAMIDE AND VINYL ALCOHOL

    Institute of Scientific and Technical Information of China (English)

    Yan-feng Li; Jun-rong Li; Lian-di Fu; Yao-zeng Li

    2000-01-01

    A kind of macroporous bead carrier of copolymer containing monomer units ofN-aminoethyl acrylamide and vinyl alcohol was synthesized, i.e. the MR-AA carrier. Papain was immobilized on the carrier using glutaraldehyde as the coupling agent. The enzymatic activity of the immobilized papain was compared with free papain using casein as a substrate, and the effects of glutaraldehyde concentration, pH, temperature, time and papain amount added on the activity recovery were also investigated. The results show that the MR-AA carrier contains reactive primary amine groups, hydrophilic amido links and hydroxyl groups, as well as macroporous structures based on its matrix (MR-AV matrix), furthermore, the activity recovery of papain in the immobilization could reach 48%~58%. In comparison with free papain, the resulting immobilized papain exhibits a remarkable thermostability and better reusability.

  17. Stability improvement of immobilized lactoperoxidase using polyaniline polymer.

    Science.gov (United States)

    Jafary, Fariba; Kashanian, Soheila; Sharieat, Ziadin Samsam; Jafary, Farzaneh; Omidfar, Kobra; Paknejad, Maliheh

    2012-12-01

    Enzyme engineering via immobilization techniques is perfectly compatible against the other chemical or biological approximate to improve enzyme functions and stability. In this study lactoperoxidase was immobilized onto polyaniline polymer activated with glutaraldehyde as a bifunctional agent, to improve enzyme properties. Polyaniline polymer was used due its unique physical and chemical properties to immobilize lactoperoxidase (LPO). The optimum activity of immobilized LPO was observed at pH 6 and 55 °C, which has been increased about 10 °C for the immobilized enzyme. The immobilized enzyme maintained absolutely active for 60 days whereas the native enzyme lost 80 % of its initial activity within this period of time. Moreover, the immobilized enzyme can be reused for several times without loss of activity. The kinetic parameter studies showed slight differences between free and immobilized enzymes. The K(m) and K(m.app) were calculated to be 0.6 and 0.4; also V(max) and V(max.app) were 1.3 and 0.9 respectively.

  18. Study of Molecular Conformation and Activity-Related Properties of Lipase Immobilized onto Core-Shell Structured Polyacrylic Acid-Coated Magnetic Silica Nanocomposite Particles.

    Science.gov (United States)

    Esmaeilnejad-Ahranjani, Parvaneh; Kazemeini, Mohammad; Singh, Gurvinder; Arpanaei, Ayyoob

    2016-04-01

    A facile approach for the preparation of core-shell structured poly(acrylic acid) (PAA)-coated Fe3O4 cluster@SiO2 nanocomposite particles as the support materials for the lipase immobilization is reported. Low- or high-molecular-weight (1800 and 100,000, respectively) PAA molecules were covalently attached onto the surface of amine-functionalized magnetic silica nanoacomposite particles. The successful preparation of particles were verified by scanning transmission electron microscopy (STEM), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), thermogravimetric analysis (TGA), zeta potential measurement, and Fourier-transform infrared (FTIR) techniques. Once lipase is covalently immobilized onto the particles with an average diameter of 210 ± 50 nm, resulting from high binding sites concentrations on the low- and high-molecular-weight PAA-coated particles, high lipase immobilization efficiencies (86.2% and 89.9%, respectively), and loading capacities (786 and 816 mg g(-1), respectively) are obtained. Results from circular dichroism (CD) analysis and catalytic activity tests reveal an increase in the β-sheet content of lipase molecules upon immobilization, along with an enhancement in their activities and stabilities. The lipases immobilized onto the low- and high-molecular-weight PAA-coated particles show maximum activities at 55 and 50 °C, respectively, which are ∼28% and ∼15% higher than that of the free lipase at its own optimum temperature (40 °C), respectively. The immobilized lipases exhibit excellent performance at broader temperature and pH ranges and high thermal and storage stabilities, as well as superior reusability. These prepared magnetic nanocomposite particles can be offered as suitable support materials for efficient immobilization of enzymes and improvement of the immobilized enzymes properties.

  19. Immobilization of peroxidase enzyme onto the porous silicon structure for enhancing its activity and stability

    OpenAIRE

    Sahare, Padmavati; Ayala, Marcela; Vazquez-Duhalt, Rafael; Agrawal, Vivechana

    2014-01-01

    In this work, a commercial peroxidase was immobilized onto porous silicon (PS) support functionalized with 3-aminopropyldiethoxysilane (APDES) and the performance of the obtained catalytic microreactor was studied. The immobilization steps were monitored and the activity of the immobilized enzyme in the PS pores was spectrophotometrically determined. The enzyme immobilization in porous silicon has demonstrated its potential as highly efficient enzymatic reactor. The effect of a polar organic ...

  20. Biodiesel production from pomace oil by using lipase immobilized onto olive pomace.

    Science.gov (United States)

    Yücel, Yasin

    2011-02-01

    In the present work, microbial lipase from Thermomyces lanuginosus was immobilized by covalent binding onto olive pomace. Immobilized support material used to produce biodiesel with pomace oil and methanol. The properties of the support and immobilized derivative were evaluated by scanning electron microscopy (SEM). The maximum immobilization of T. lanuginosus was obtained as 18.67 mg/g support and the highest specific activity was 10.31 U/mg protein. The properties of immobilized lipase were studied. The effects of protein concentration, pH and buffer concentration on the immobilization and lipase activity were investigated. Biodiesel production using the immobilized lipase was realized by a three-step addition of methanol to avoid strong substrate inhibition. Under the optimized conditions, the maximum biodiesel yield was 93% at 25°C in 24h reaction. The immobilized enzyme retained its activity during the 10 repeated batch reactions.

  1. Metal immobilization in soils using synthetic zeolites

    NARCIS (Netherlands)

    Osté, L.A.; Lexmond, T.M.; Riemsdijk, van W.H.

    2002-01-01

    In situ immobilization of heavy metals in contaminated soils is a technique to improve soil quality. Synthetic zeolites are potentially useful additives to bind heavy metals. This study selected the most effective zeolite in cadmium and zinc binding out of six synthetic zeolites (mordenite-type, fau

  2. Metal immobilization in soils using synthetic zeolites

    NARCIS (Netherlands)

    Osté, L.A.; Lexmond, T.M.; Riemsdijk, van W.H.

    2002-01-01

    In situ immobilization of heavy metals in contaminated soils is a technique to improve soil quality. Synthetic zeolites are potentially useful additives to bind heavy metals. This study selected the most effective zeolite in cadmium and zinc binding out of six synthetic zeolites (mordenite-type,

  3. Metabolic alkalosis during immobilization in monkeys (M. nemestrina)

    Science.gov (United States)

    Young, D. R.; Yeh, I.; Swenson, R. S.

    1983-01-01

    The systemic and renal acid-base response of monkeys during ten weeks of immobilization was studied. By three weeks of immobilization, arterial pH and bicarbonate concentrations were elevated (chronic metabolic alkalosis). Net urinary acid excretion increased in immobilized animals. Urinary bicarbonate excretion decreased during the first three weeks of immobilization, and then returned to control levels. Sustained increases in urinary ammonium excretion were seen throughout the time duration of immobilization. Neither potassium depletion nor hypokalemia was observed. Most parameters returned promptly to the normal range during the first week of recovery. Factors tentatively associated with changes in acid-base status of monkeys include contraction of extracellular fluid volume, retention of bicarbonate, increased acid excretion, and possible participation of extrarenal buffers.

  4. The biosorption capacity of biochar for 4-bromodiphengl ether: study of its kinetics, mechanism, and use as a carrier for immobilized bacteria.

    Science.gov (United States)

    Du, Jingting; Sun, Pengfei; Feng, Zhuo; Zhang, Xin; Zhao, Yuhua

    2016-02-01

    Polybrominated diphenyl ethers (PBDEs) are known as ubiquitous pollutants in ecological systems and thus pose a great threat to the health of humans and other organisms due to their bioamplification and bioaccumulation along the food chain. The present study was designed to investigate the biosorption capacity of biochar for the removal of 4-monobromodiphengl ether and its synergistic effect when used as a carrier to immobilize the 4-monobromodiphengl ether-degrading strain Sphingomonas sp. DZ3. The raw biochar material was prepared by pyrolyzing maize straw at 350 °C under oxygen-limited conditions. The maximum biosorption capacity of biochar for 4-bromodiphengl ether was determined to be 50.23 mg/L under an initial concentration of 800 mg/L at pH 7.0 and 40 °C. The data obtained from the biosorption studies were fitted successfully with the pseudo-first-order kinetic and Freundlich isotherm models. The Weber-Morris model analysis indicated that intraparticle diffusion was the limiting step in the biosorption of 4-bromodiphengl ether onto the biosorbent. The values of thermodynamic parameters △G0 were calculated as -24.61 kJ/mol (20 °C), -24.35 kJ/mol (30 °C), and -23.98 kJ/mol (40 °C), △S(0) was -8.45 kJ/mol/K, and △H(0) was 21.36 kJ/mol. The artificial neural network analysis indicated that the initial concentration appeared to be the most influential parameter on the biosorption processes. The removal rate of 4-bromodiphengl ether achieved using the biochar-microorganism system was increased by 63 and 83% compared with the rates obtained with biochar and the strain individually, respectively. The morphology of the biochar and immobilized strain was determined using a scanning electron microscope, and information of the surface functional groups of biochar was obtained through an infrared spectra study.

  5. Effect of low molecular weight additives on immobilization strength, activity, and conformation of protein immobilized on PVC and UHMWPE.

    Science.gov (United States)

    Kondyurin, Alexey; Nosworthy, Neil J; Bilek, Marcela M M

    2011-05-17

    Horseradish peroxidase (HRP) was immobilized onto both plasticized and unplasticized polyvinylchloride (PVC) and ultrahigh molecular weight polyethylene (UHMWPE). Plasma immersion ion implantation (PIII) in a nitrogen plasma with 20 kV bias was used to facilitate covalent immobilization and to improve the wettability of the surfaces. The surfaces and immobilized protein were studied using attenuated total reflection infrared (ATR-IR) spectroscopy and water contact angle measurements. Protein elution on exposure to repeated sodium dodecyl sulfate (SDS) washing was used to assess the strength of HRP immobilization. The presence of low molecular weight components (plasticizer, additives in solvent, unreacted monomers, adsorbed molecules on surface) was found to have a major influence on the strength of immobilization and the conformation of the protein on the samples not exposed to the PIII treatment. A phenomenological model considering interactions between the low molecular weight components, the protein molecule, and the surface is developed to explain these observations.

  6. Silica-Immobilized Enzyme Reactors

    Science.gov (United States)

    2007-08-01

    immobilized artificial membrane chromatography and lysophospholipid micellar electrokinetic chromatography . J. Chromatogr. A 1998, 810, 95-103. 50...Journal of Liquid Chromatography and Related Technologies. Air Force Research Laboratory Materials and Manufacturing Directorate Airbase...immobilized enzyme reactors (IMERs) can also be integrated directly to further analytical methods such as liquid chromatography or mass spectrometry.[6] In

  7. [Immobilized microorganisms and water purification].

    Science.gov (United States)

    Mogilevich, N F

    1995-01-01

    Advantages and disadvantages of cells of aerobic microorganisms immobilized by the type of adhesion and incorporation into the gel beads, the amount of retained biomass, limitations of diffusion of oxygen and nutrients, viability, morphology, biochemical properties are described. Immobilized biocatalysts are discussed in the aspect of their use in purification of sewage waters.

  8. Immobilization of horseradish peroxidase onto kaolin.

    Science.gov (United States)

    Šekuljica, Nataša Ž; Prlainović, Nevena Ž; Jovanović, Jelena R; Stefanović, Andrea B; Djokić, Veljko R; Mijin, Dušan Ž; Knežević-Jugović, Zorica D

    2016-03-01

    Kaolin showed as a very perspective carrier for the enzyme immobilization and it was used for the adsorption of horseradish peroxidase (HRP). The effects of the enzyme concentration and pH on the immobilization efficiency were studied in the reaction with pyrogallol and anthraquinone dye C.I. Acid Violet 109 (AV 109). In addition, Fourier transform infrared spectroscopy, scanning electron microscopy and analysis by Brunauer-Emmett-Teller were performed for kaolin, thermally activated kaolin and the immobilized enzyme. It has been shown that 0.1 IU of HRP-kaolin decolorized 87 % of dye solution, under the optimal conditions (pH 5.0, temperature 24 °C, dye concentration 40 mg/L and 0.2 mM of H2O2) within 40 min. The immobilized HRP decolorization follows the Ping Pong Bi-Bi mechanism with dead-end inhibition by the dye. The biocatalyst retained 35 ± 0.9 % of the initial activity after seven cycles of reuse in the decolorization reaction of AV 109 under optimal conditions in a batch reactor. The obtained kinetic parameters and reusability study confirmed improvement in performances of k-HRP compared to free, indicating that k-HRP has a great potential for environmental purposes.

  9. Electron tomography of cryo-immobilized plant tissue: a novel approach to studying 3D macromolecular architecture of mature plant cell walls in situ.

    Science.gov (United States)

    Sarkar, Purbasha; Bosneaga, Elena; Yap, Edgar G; Das, Jyotirmoy; Tsai, Wen-Ting; Cabal, Angelo; Neuhaus, Erica; Maji, Dolonchampa; Kumar, Shailabh; Joo, Michael; Yakovlev, Sergey; Csencsits, Roseann; Yu, Zeyun; Bajaj, Chandrajit; Downing, Kenneth H; Auer, Manfred

    2014-01-01

    Cost-effective production of lignocellulosic biofuel requires efficient breakdown of cell walls present in plant biomass to retrieve the wall polysaccharides for fermentation. In-depth knowledge of plant cell wall composition is therefore essential for improving the fuel production process. The precise spatial three-dimensional (3D) organization of cellulose, hemicellulose, pectin and lignin within plant cell walls remains unclear to date since the microscopy techniques used so far have been limited to two-dimensional, topographic or low-resolution imaging, or required isolation or chemical extraction of the cell walls. In this paper we demonstrate that by cryo-immobilizing fresh tissue, then either cryo-sectioning or freeze-substituting and resin embedding, followed by cryo- or room temperature (RT) electron tomography, respectively, we can visualize previously unseen details of plant cell wall architecture in 3D, at macromolecular resolution (∼ 2 nm), and in near-native state. Qualitative and quantitative analyses showed that wall organization of cryo-immobilized samples were preserved remarkably better than conventionally prepared samples that suffer substantial extraction. Lignin-less primary cell walls were well preserved in both self-pressurized rapidly frozen (SPRF), cryo-sectioned samples as well as high-pressure frozen, freeze-substituted and resin embedded (HPF-FS-resin) samples. Lignin-rich secondary cell walls appeared featureless in HPF-FS-resin sections presumably due to poor stain penetration, but their macromolecular features could be visualized in unprecedented details in our cryo-sections. While cryo-tomography of vitreous tissue sections is currently proving to be instrumental in developing 3D models of lignin-rich secondary cell walls, here we confirm that the technically easier method of RT-tomography of HPF-FS-resin sections could be used immediately for routine study of low-lignin cell walls. As a proof of principle, we characterized the

  10. Electron tomography of cryo-immobilized plant tissue: a novel approach to studying 3D macromolecular architecture of mature plant cell walls in situ.

    Directory of Open Access Journals (Sweden)

    Purbasha Sarkar

    Full Text Available Cost-effective production of lignocellulosic biofuel requires efficient breakdown of cell walls present in plant biomass to retrieve the wall polysaccharides for fermentation. In-depth knowledge of plant cell wall composition is therefore essential for improving the fuel production process. The precise spatial three-dimensional (3D organization of cellulose, hemicellulose, pectin and lignin within plant cell walls remains unclear to date since the microscopy techniques used so far have been limited to two-dimensional, topographic or low-resolution imaging, or required isolation or chemical extraction of the cell walls. In this paper we demonstrate that by cryo-immobilizing fresh tissue, then either cryo-sectioning or freeze-substituting and resin embedding, followed by cryo- or room temperature (RT electron tomography, respectively, we can visualize previously unseen details of plant cell wall architecture in 3D, at macromolecular resolution (∼ 2 nm, and in near-native state. Qualitative and quantitative analyses showed that wall organization of cryo-immobilized samples were preserved remarkably better than conventionally prepared samples that suffer substantial extraction. Lignin-less primary cell walls were well preserved in both self-pressurized rapidly frozen (SPRF, cryo-sectioned samples as well as high-pressure frozen, freeze-substituted and resin embedded (HPF-FS-resin samples. Lignin-rich secondary cell walls appeared featureless in HPF-FS-resin sections presumably due to poor stain penetration, but their macromolecular features could be visualized in unprecedented details in our cryo-sections. While cryo-tomography of vitreous tissue sections is currently proving to be instrumental in developing 3D models of lignin-rich secondary cell walls, here we confirm that the technically easier method of RT-tomography of HPF-FS-resin sections could be used immediately for routine study of low-lignin cell walls. As a proof of principle, we

  11. Potential immobilized Saccharomyces cerevisiae as heavy metal removal

    Science.gov (United States)

    Raffar, Nur Izzati Abdul; Rahman, Nadhratul Nur Ain Abdul; Alrozi, Rasyidah; Senusi, Faraziehan; Chang, Siu Hua

    2015-05-01

    Biosorption of copper ion using treated and untreated immobilized Saccharomyces cerevisiae from aqueous solution was investigate in this study. S.cerevisiae has been choosing as biosorbent due to low cost, easy and continuously available from various industries. In this study, the ability of treated and untreated immobilized S.cerevisiae in removing copper ion influence by the effect of pH solution, and initial concentration of copper ion with contact time. Besides, adsorption isotherm and kinetic model also studied. The result indicated that the copper ion uptake on treated and untreated immobilized S.cerevisiae was increased with increasing of contact time and initial concentration of copper ion. The optimum pH for copper ion uptake on untreated and treated immobilized S.cerevisiae at 4 and 6. From the data obtained of copper ion uptake, the adsorption isotherm was fitted well by Freundlich model for treated immobilized S.cerevisiae and Langmuir model for untreated immobilized S.cerevisiae according to high correlation coefficient. Meanwhile, the pseudo second order was described as suitable model present according to high correlation coefficient. Since the application of biosorption process has been received more attention from numerous researchers as a potential process to be applied in the industry, future study will be conducted to investigate the potential of immobilized S.cerevisiae in continuous process.

  12. Study of Producing Biodiesel from Waste Oils with Immobilized Candida Lipase%地沟油固定化脂肪酶生产生物柴油

    Institute of Scientific and Technical Information of China (English)

    付严; 常杰; 陈英明; 王学伟; 谭天伟

    2007-01-01

    The transesterification of waste oils and methanol to biodiesel catalyzed by immobilized Candida lipase in three stages fixed bed reactors was studied. Saponification value, acid value of waste oils and water content were tested. The influence of velocity of reaction liquid, solvent and water content in the reaction was also researched. The yield of biodiesel was 94% in the condition of n(oil)∶ n(methanol)=1∶ 1 in every stage of fixed bed, 20% hexane as solvent, 20% water content, 40℃.%研究了地沟油和甲醇在三段式反应器中固定化脂肪酶上合成生物柴油.对地沟油的酸值、皂化值以及水含量进行了检测.考察了进料流速、溶剂、水含量对反映的影响.在40℃,正己烷作溶剂,添加水含量为地沟油质量的20%,每一段反应器中添加的甲醇与地沟油的摩尔比为1∶ 1时,生物柴油产率为94%.

  13. Immobilization of Pb, Cd, and Zn in a contaminated soil using eggshell and banana stem amendments: metal leachability and a sequential extraction study.

    Science.gov (United States)

    Ashrafi, Mehrnaz; Mohamad, Sharifah; Yusoff, Ismail; Shahul Hamid, Fauziah

    2015-01-01

    Heavy-metal-contaminated soil is one of the major environmental pollution issues all over the world. In this study, two low-cost amendments, inorganic eggshell and organic banana stem, were applied to slightly alkaline soil for the purpose of in situ immobilization of Pb, Cd, and Zn. The artificially metal-contaminated soil was treated with 5% eggshell or 10% banana stem. To simulate the rainfall conditions, a metal leaching experiment for a period of 12 weeks was designed, and the total concentrations of the metals in the leachates were determined every 2 weeks. The results from the metal leaching analysis revealed that eggshell amendment generally reduced the concentrations of Pb, Cd, and Zn in the leachates, whereas banana stem amendment was effective only on the reduction of Cd concentration in the leachates. A sequential extraction analysis was carried out at the end of the experiment to find out the speciation of the heavy metals in the amended soils. Eggshell amendment notably decreased mobility of Pb, Cd, and Zn in the soil by transforming their readily available forms to less accessible fractions. Banana stem amendment also reduced exchangeable form of Cd and increased its residual form in the soil.

  14. Highly sensitive detection of influenza virus in saliva by real-time PCR method using sugar chain-immobilized gold nanoparticles; application to clinical studies

    Directory of Open Access Journals (Sweden)

    Yasuo Suda

    2015-09-01

    Full Text Available A highly sensitive and convenient method for detecting influenza virus was developed using modified end-point melt curve analysis of a RT-qPCR SYBR Green method and influenza virus-binding sugar chain-immobilized gold-nanoparticles (SGNP. Because SGNPs capture influenza viruses, the virus-SGNP complex was separated easily by centrifugation. Viral RNA was detected at very low concentrations, suggesting that SGNP increased sensitivity compared with standard methods. This method was applied to clinical studies. Influenza viruses were detected in saliva of patients or inpatients who had been considered influenza-free by a rapid diagnostic assay of nasal swabs. Furthermore, the method was applied to a human trial of prophylactic anti-influenza properties of yogurt containing Lactobacillus acidophilus L-92. The incidence of influenza viruses in saliva of the L-92 group was found to be significantly lower compared to the control group. Thus, this method was useful for monitoring the course of anti-influenza treatment or preventive measures against nosocomial infection.

  15. Comparative Study on the Photodegradation of Acid Black 26 from Synthetic Wastewater using Slurry and Immobilized TiO2 on the Sackcloth Fiber

    Directory of Open Access Journals (Sweden)

    Somayeh Alijani

    2013-09-01

    Results: The XRD results did not show significant changes in the structure of TiO2 as a consequence of the immobilization procedure. The formation of titania crystallites in the sackcloth fiber was confirmed by SEM. Experimental results showed that after 60 min, the degradation percentage of Acid Black 26 with the immobilized TiO2 particles was about 60%, which was higher than that with TiO2 slurry. Based on the COD results, after 3 h, the TiO2-coated sackcloth fiber effectively decomposed 94% of the organic compounds presenting in dye solution during the degradation of Acid Black 26. Conclusion: The titania nanoparticles immobilized on the sackcloth fiber can be used as an effective and environmental friendly photocatalyst in the degradation of colored wastewater.

  16. Two-dimensional (2D) infrared correlation study of the structural characterization of a surface immobilized polypeptide film stimulated by pH

    Science.gov (United States)

    Chae, Boknam; Son, Seok Ho; Kwak, Young Jun; Jung, Young Mee; Lee, Seung Woo

    2016-11-01

    The pH-induced structural changes to surface immobilized poly (L-glutamic acid) (PLGA) films were examined by Fourier transform infrared (FTIR) spectroscopy and two-dimensional (2D) correlation analysis. Significant spectral changes were observed in the FTIR spectra of the surface immobilized PLGA film between pH 6 and 7. The 2D correlation spectra constructed from the pH-dependent FTIR spectra of the surface immobilized PLGA films revealed the spectral changes induced by the alternations of the protonation state of the carboxylic acid group in the PLGA side chain. When the pH was increased from 6 to 8, weak spectral changes in the secondary structure of the PLGA main chain were induced by deprotonation of the carboxylic acid side group.

  17. A density functional theory study of the electronic properties of Os(II) and Os(III) complexes immobilized on Au(111)

    DEFF Research Database (Denmark)

    O'Boyle, N.M.; Albrecht, Tim; Murgida, D.H.

    2007-01-01

    from the metal center to the P0P ligand. The surface is modeled by a cluster of 28 gold atoms and gives a good description of the effect of immobilization on the electronic properties of the complexes. The results show that the coupling between the immobilized complex and the gold surface involves...... electronic polarization at the adsorbate/substrate interface rather than the formation of a covalent bond. However, the cluster is too small to fully represent bulk gold with the result that, contrary to what is experimentally observed, the DFT calculation predicts that the gold surface is more easily...

  18. Immobilization of amyloglucosidase onto macroporous cryogels for continuous glucose production from starch.

    Science.gov (United States)

    Uygun, Murat; Akduman, Begüm; Ergönül, Bülent; Aktaş Uygun, Deniz; Akgöl, Sinan; Denizli, Adil

    2015-01-01

    Poly(methyl methacrylate-glycidyl methacrylate) [Poly(MMA-GMA)] cryogels were synthesized using monomers of methylmethacrylic acid and epoxy group bearing GMA via radical cryopolymerization technique. Synthesized cryogels were used for the immobilization of amyloglucosidase to the cryogel surface using epoxy chemistry. Characterizations of the free and immobilized amyloglucosidase were carried out by comparing the optimum and kinetic parameters of enzymes. For this, pH and temperature profiles of free and immobilized preparation were studied and, it was found that, optimum pH of enzyme was not change upon immobilization (pH 5.0), while optimum temperature of the enzyme shifted 10 °C to warmer region after immobilization (optimum temperatures for free and immobilized enzyme were 55 and 65 °C, respectively). Kinetic parameters of free and immobilized enzyme were also investigated and Km values of free and immobilized amyloglucosidase were found to be 2.743 and 0.865 mg/mL, respectively. Vmax of immobilized amyloglucosidase was found to be (0.496 µmol/min) about four times less than that of free enzyme (2.020 µmol/min). Storage and operational stabilities of immobilized amyloglucosidase were also studied and it was showed that immobilized preparation had much more stability than free preparation. In the present work, amyloglucosidase immobilized poly(MMA-GMA) cryogels were used for continuous glucose syrup production from starch for the first time. Efficiency of immobilized enzyme was investigated and released amount of glucose was found to be 2.54 mg/mL at the end of the 5 min of hydrolysis. The results indicate that the epoxy functionalized cryogels offer a good alternative for amyloglucosidase immobilization applications with increased operational and thermal stability, and reusability. Also, these cryogels can be used for immobilization of other industrially valuable enzymes beyond amyloglucosidase.

  19. Immobilized/P25/DSAT and Immobilized/Kronos/DSAT on Photocatalytic Degradation of Reactive Red 4 Under Fluorescent Light

    Directory of Open Access Journals (Sweden)

    Azami M. S.

    2016-01-01

    Full Text Available In this work, photocatalytic degradation of Reactive Red 4 (RR4 using immobilized P25 and kronos were performed under fluorescent light sources. The photocatalysis activity for both catalysts was investigated under fluorescent lamp source which consist UV and Visible light. The effect of various parameters such as initial concentration, initial pH and strenght of immobilized plate were studied. The result showed that 90% of RR4 dye was degrade in 1 hr using immobilized/kronos/DSAT at 100 mg L-1 of RR4 dye while 81% degradation was achieved by immobilized/P25/DSAT at the same condition. The lowest pH showed the higher photocatalytic activity. Hence, the effect of dye concentration and pH on the photocatalysis study can be related with the behavior of environmental pollution. The low strength showed by immobilized/P25/DSAT where it remain 37 % as compared with strength of immobilized/kronos/DSAT (52 wt.%. For the future work, the polymer binder like Polyvinyl alcohol (PVA, Polyethylene glycol (PEG, and others polymers can be apply in immobilized study to overcome the strength problem.

  20. Silk-Cocoon Matrix Immobilized Lipase Catalyzed Transesterification of Sunflower Oil for Production of Biodiesel

    OpenAIRE

    Sushovan Chatterjee; Dipti Yadav; Lepakshi Barbora; Pinakeswar Mahanta; Pranab Goswami

    2014-01-01

    Biodiesel from sunflower oil using lipase chemically immobilized on silk-cocoon matrix in a packed-bed bioreactor was investigated. The immobilization was demonstrated by field-emission scanning electron microscopy and activity study. The lipase loading was 738.74 U (~0.01 g lipase powder)/g-lipase-immobilized matrix. The Km (Michaelis-Menten constant) of the free and the immobilized lipase was 451.26 μM and 257.26 μM, respectively. Low Km value of the immobilized lipase is attributed to the ...

  1. Uranium Immobilization in Wetland Soils

    Science.gov (United States)

    Jaffe, Peter R.; Koster van Groos, Paul G.; Li, Dien; Chang, Hyun-Shik; Seaman, John C.; Kaplan, Daniel I.; Peacock, Aaron D.; Scheckel, Kirk

    2014-05-01

    In wetlands, which are a major feature at the groundwater-surface water interface, plants deliver oxygen to the subsurface to keep root tissue aerobic. Some of this oxygen leaches into the rhizosphere where it will oxidize iron that typically precipitates on or near roots. Furthermore, plans provide carbon via root exudates and turnover, which in the presence of the iron oxides drives the activity of heterotrophic iron reducers in wetland soils. Oxidized iron is an important electron acceptor for many microbially-driven transformations, which can affect the fate and transport of several pollutants. It has been shown that heterotrophic iron reducing organisms, such as Geobacter sp., can reduce water soluble U(VI) to insoluble U(IV). The goal of this study was to determine if and how iron cycling in the wetland rhizosphere affects uranium dynamics. For this purpose, we operated a series of small-scale wetland mesocosms in a greenhouse to simulate the discharge of uranium-contaminated groundwater to surface waters. The mesocosms were operated with two different Fe(II) loading rates, two plant types, and unplanted controls. The mesocosms contained zones of root exclusion to differentiate between the direct presence and absence of roots in the planted mesocosms. The mesocosms were operated for several month to get fully established, after which a U(VI) solution was fed for 80 days. The mesocosms were then sacrificed and analyzed for solid-associated chemical species, microbiological characterization, micro-X-ray florescence (µ-XRF) mapping of Fe and U on the root surface, and U speciation via X-ray Absorption Near Edge Structure (XANES). Results showed that bacterial numbers including Geobacter sp., Fe(III), as well as total uranium, were highest on roots, followed by sediments near roots, and lowest in zones without much root influence. Results from the µ-XRF mapping on root surfaces indicated a strong spatial correlation between Fe and U. This correlation was

  2. Immobilized soybean hull peroxidase for the oxidation of phenolic compounds in coffee processing wastewater.

    Science.gov (United States)

    Chagas, Pricila Maria Batista; Torres, Juliana Arriel; Silva, Maria Cristina; Corrêa, Angelita Duarte

    2015-11-01

    Chitosan beads were prepared, using glutaraldehyde as a crosslinking agent for the immobilization of soybean hull peroxidase (SBP). The activity of free and immobilized SBP was studied. The optimum pH was 6.0 for both the free and immobilized enzyme; however, enzyme activity became more dependent on the temperature after immobilization. This study evaluated the potential use of immobilized and free enzyme in the oxidation of caffeic acid, of synthetic phenolic solution (SPS) and of total phenolic compounds in coffee processing wastewater (CPW). Some factors, such as reaction time, amount of H2O2 and caffeic acid were evaluated, in order to determine the optimum conditions for enzyme performance. Both enzymes showed a potential in the removal of caffeic acid, SPS and CPW, and immobilized SBP had the highest oxidation performance. The immobilized enzyme showed a potential of 50% in the oxidation of caffeic acid after 4 consecutive cycles.

  3. Application of immobilized cells to the treatment of cyanide wastewater.

    Science.gov (United States)

    Chen, C Y; Kao, C M; Chen, S C; Chien, H Y; Lin, C E

    2007-01-01

    Cyanide is highly toxic to living organisms, particularly in inactivating the respiration system by tightly binding to terminal oxidase. To protect the environment and water bodies, wastewater containing cyanide must be treated before discharging into the environment. Biological treatment is a cost-effective and environmentally acceptable method for cyanide removal compared with the other techniques currently in use. Klebsiella oxytoca (K. oxytoca), isolated from cyanide-containing industrial wastewater, has been shown to be able to biodegrade cyanide to non-toxic end products. The technology of immobilized cells can be applied in biological treatment to enhance the efficiency and effectiveness of biodegradation. In this study, potassium cyanide (KCN) was used as the target compound and both alginate (AL) and cellulose triacetate (CTA) techniques were applied for the preparation of immobilized cells. Results from this study show that KCN can be utilized as the sole nitrogen source by K. oxytoca. The free suspension systems reveal that the cell viability was highly affected by initial KCN concentration, pH, and temperature. Results show that immobilized cell systems could tolerate a higher level of KCN concentration and wider ranges of pH and temperature, especially in the system with CTA gel beads. Results show that a longer incubation period was required for KCN degradation using immobilized cells compared to the free suspended systems. This might be due to internal mass transfer limitations. Results also indicate that immobilized systems can support a higher biomass concentration. Complete KCN degradation was observed after the operation of four consecutive degradation experiments with the same batch of immobilized cells. This suggests that the activity of the immobilized cells can be maintained and KCN can be used as the nitrogen source throughout KCN degradation experiments. Results reveal that the application of immobilized cells of K. oxytoca is advantageous

  4. Polymer-assisted iron oxide magnetic nanoparticle immobilized keratinase

    Energy Technology Data Exchange (ETDEWEB)

    Konwarh, Rocktotpal; Karak, Niranjan [Advanced Polymer and Nanomaterial Laboratory, Department of Chemical Sciences, Tezpur University, Tezpur-784028, Assam (India); Rai, Sudhir Kumar; Mukherjee, Ashis Kumar [Department of Molecular Biology and Biotechnology, Tezpur University, Tezpur-784028, Assam (India)], E-mail: karakniranjan@yahoo.com

    2009-06-03

    Nanotechnology holds the prospect for avant-garde changes to improve the performance of materials in various sectors. The domain of enzyme biotechnology is no exception. Immobilization of industrially important enzymes onto nanomaterials, with improved performance, would pave the way to myriad application-based commercialization. Keratinase produced by Bacillus subtilis was immobilized onto poly(ethylene glycol)-supported Fe{sub 3}O{sub 4} superparamagnetic nanoparticles. The optimization process showed that the highest enzyme activity was noted when immobilized onto cyanamide-activated PEG-assisted MNP prepared under conditions of 25 deg. C and pH 7.2 of the reaction mixture before addition of H{sub 2}O{sub 2} (3% w/w), 2% (w/v) PEG{sub 6000} and 0.062:1 molar ratio of PEG to FeCl{sub 2}{center_dot}4H{sub 2}O. Further statistical optimization using response surface methodology yielded an R{sup 2} value that could explain more than 94% of the sample variations. Along with the magnetization studies, the immobilization of the enzyme onto the PEG-assisted MNP was characterized by UV, XRD, FTIR and TEM. The immobilization process had resulted in an almost fourfold increase in the enzyme activity over the free enzyme. Furthermore, the immobilized enzyme exhibited a significant thermostability, storage stability and recyclability. The leather-industry-oriented application of the immobilized enzyme was tested for the dehairing of goat-skin.

  5. Polymer-assisted iron oxide magnetic nanoparticle immobilized keratinase

    Science.gov (United States)

    Konwarh, Rocktotpal; Karak, Niranjan; Rai, Sudhir Kumar; Mukherjee, Ashis Kumar

    2009-06-01

    Nanotechnology holds the prospect for avant-garde changes to improve the performance of materials in various sectors. The domain of enzyme biotechnology is no exception. Immobilization of industrially important enzymes onto nanomaterials, with improved performance, would pave the way to myriad application-based commercialization. Keratinase produced by Bacillus subtilis was immobilized onto poly(ethylene glycol)-supported Fe3O4 superparamagnetic nanoparticles. The optimization process showed that the highest enzyme activity was noted when immobilized onto cyanamide-activated PEG-assisted MNP prepared under conditions of 25 °C and pH 7.2 of the reaction mixture before addition of H2O2 (3% w/w), 2% (w/v) PEG6000 and 0.062:1 molar ratio of PEG to FeCl2·4H2O. Further statistical optimization using response surface methodology yielded an R2 value that could explain more than 94% of the sample variations. Along with the magnetization studies, the immobilization of the enzyme onto the PEG-assisted MNP was characterized by UV, XRD, FTIR and TEM. The immobilization process had resulted in an almost fourfold increase in the enzyme activity over the free enzyme. Furthermore, the immobilized enzyme exhibited a significant thermostability, storage stability and recyclability. The leather-industry-oriented application of the immobilized enzyme was tested for the dehairing of goat-skin.

  6. Immobilization of maltase from Saccharomyces cerevisiae on thiosulfonate supports

    Directory of Open Access Journals (Sweden)

    Mihailović Mladen

    2016-01-01

    Full Text Available In this study, two commercial supports (Eupergit® C and Purolite® A109 were chemically modified in order to introduce thiosulfonate groups, which could subsequently exclusively react with cysteine residues on enzyme surface. Thereafter, the immobilization of maltase from Saccharomyces cerevisiae onto obtained thiosulfonate-activated supports was performed, 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 theses thiosulfonate supports. Desorption experiments, performed on samples taken during immobilization, proved that immobilization on thiosulfonate supports encompass first step of fast adsorption on support and second slower step of the covalent bond formation between thiosulfonate groups and thiol groups of cysteine. More importantly, although enzyme coupling occurs via covalent bond formation, performed immobilization proved to be reversible, since it was shown that 95% of immobilized activity can be detached from support after treatment with thiol reagent (β-mercaptoethanol, thus support can be reused after enzyme inactivation. [Projekat Ministarstva nauke Republike Srbije, br. III 46010

  7. Production and Immobilization of Partially Purified Lipase From Penicillium chrysogenum

    Directory of Open Access Journals (Sweden)

    Shafei, M. S.

    2010-01-01

    Full Text Available An extracellular lipase from Penicillium chrysogenum produced maximal activity 225 U/mL after four days at pH 6.5. It was partially purified 4.1 fold by ammonium sulphate precipitation (70%. The enzyme was immobilized on various carriers viz. alginate, k-carrageenan and polyacrylamide gel. The immobilization yield of enzyme immobilized in kcarrageenan and polyacrylamide gel (63.41% and 48.93% respectively was low in comparison to that immobilized with alginate (81.57%. Different concentrations of alginate were tried to study their effect on lipase production. Maximum immobilization yield was observed with 3% alginate. The optimal pH of the partially purified lipase was 7.5 and the optimum temperature was 35 °C. At 60 °C the immobilized enzyme retained 62.79% of its activity. Broader pH tolerance and higher heat stability could be achieved by this method. Immobilized lipase retained 72.09% relative activity after six hydrolysis cycles.

  8. Acetylcholinesterase immobilized onto PEI-coated silica nanoparticles.

    Science.gov (United States)

    Tumturk, Hayrettin; Yüksekdag, Hazer

    2016-01-01

    Polyethyleneimine (PEI) coated-silica nanoparticles were prepared by the Stöber method. The formation and the structure of the nanoparticles were characterized by ATR-FT-IR spectroscopy and transmission electron microscopy (TEM). TEM images of the silica and PEI-coated nanoparticles revealed that they were well dispersed and that there was no agglomeration. The acetylcholineesterase enzyme was immobilized onto these nanoparticles. The effects of pH and temperature on the storage stability of the free and immobilized enzyme were investigated. The optimum pHs for free and immobilized enzymes were determined as 7.0 and 8.0, respectively. The optimum temperatures for free and immobilized enzymes were found to be 30.0 and 35.0°C, respectively. The maximum reaction rate (Vmax) and the Michaelis-Menten constant (Km) were investigated for the free and immobilized enzyme. The storage stability of acetylcholinesterase was increased when immobilized onto the novel PEI-coated silica nanoparticles. The reuse numbers of immobilized enzyme were also studied. These hybrid nanoparticles are desirable as carriers for biomedical applications.

  9. Recycling of textile bleaching effluents for dyeing using immobilized catalase

    OpenAIRE

    Costa, Silgia; Tzanov,Tzanko; Carneiro, Ana Filipa Gonçalves da Costa; Gübitz, Georg M.; Paulo, Artur Cavaco

    2002-01-01

    Catalase was immobilized on alumina carrier and crosslinked with glutaraldehyde. Storing stability, temperature and pH profiles of enzyme activity were studied in a column reactor with recirculation and in a batch stirred-tank reactor. The immobilized enzyme retained 44% of its activity at pH 11, 30 °C and 90% at 80 °C, pH 7. The half-life time of the immobilized catalase was increased to 2 h at pH 12, and 60 °C. Acceptable results were achieved when the residual water from the washing proces...

  10. Surface immobilization of antibody on silk fibroin through conformational transition.

    Science.gov (United States)

    Lu, Qiang; Wang, Xiaoqin; Zhu, Hesun; Kaplan, David L

    2011-07-01

    In recent studies silk fibroin has been explored as a new material platform for biosensors. Based on these developments, a procedure for the immobilization of antibodies on silk fibroin substrates was developed as a route to functionalizing these biosensor systems. By controlling the conformational transition of the silk fibroin, a primary antibody was immobilized and enriched at the surface of silk fibroin substrates under mild reaction conditions to maintain antibody function. Compared to chemical crosslinking, the immobilization efficiency in the present approach was increased significantly. This method, achieving high loading of antibody while retaining function, improves the feasibility of silk fibroin as a platform material for biosensor applications.

  11. 16s rRNA Identification of Pediococcus spp. from Broiler and Studies of Adherence Ability on Immobilized Mucus

    OpenAIRE

    Ema Damayanti; Lies Mira Yusiati; Achmad Dinoto

    2015-01-01

    The objectives of this research were to study taxonomical status of lactic acid bacteria (LAB) isolated from broiler and adherence ability on mucus in vitro. Molecular analysis was performed by analyzing 16S rRNA gene using universal primer. The adherence assay on mucus was carried out using microplate method with total plate count (TPC), absorbance (A550) and confirmed by scanning electron microscopy (SEM). The results of this studies revealed that three of LAB isolates have closed relation ...

  12. SERR Spectroelectrochemical Study of Cytochrome cd1 Nitrite Reductase Co-Immobilized with Physiological Redox Partner Cytochrome c552 on Biocompatible Metal Electrodes.

    Directory of Open Access Journals (Sweden)

    Célia M Silveira

    Full Text Available Cytochrome cd1 nitrite reductases (cd1NiRs catalyze the one-electron reduction of nitrite to nitric oxide. Due to their catalytic reaction, cd1NiRs are regarded as promising components for biosensing, bioremediation and biotechnological applications. Motivated by earlier findings that catalytic activity of cd1NiR from Marinobacter hydrocarbonoclasticus (Mhcd1 depends on the presence of its physiological redox partner, cytochrome c552 (cyt c552, we show here a detailed surface enhanced resonance Raman characterization of Mhcd1 and cyt c552 attached to biocompatible electrodes in conditions which allow direct electron transfer between the conducting support and immobilized proteins. Mhcd1 and cyt c552 are co-immobilized on silver electrodes coated with self-assembled monolayers (SAMs and the electrocatalytic activity of Ag // SAM // Mhcd1 // cyt c552 and Ag // SAM // cyt c552 // Mhcd1 constructs is tested in the presence of nitrite. Simultaneous evaluation of structural and thermodynamic properties of the immobilized proteins reveals that cyt c552 retains its native properties, while the redox potential of apparently intact Mhcd1 undergoes a ~150 mV negative shift upon adsorption. Neither of the immobilization strategies results in an active Mhcd1, reinforcing the idea that subtle and very specific interactions between Mhcd1 and cyt c552 govern efficient intermolecular electron transfer and catalytic activity of Mhcd1.

  13. 木瓜蛋白酶的原位固定化及理化性质研究%Study on in situ immobilization and characterization of papain

    Institute of Scientific and Technical Information of China (English)

    苏二正; 李明亮; 魏东芝

    2014-01-01

    Amino carriers could immobilize the papain in situ in the PEG phase, which gave high papain immobilization yield (95.9%) and activity recovery (51.3%), and thus solved the difficulty in separation of the target protein and pol⁃ymer after aqueous two⁃phase purification. The optimum pH of the immobilized papain was around 7.0, and the optimum temperature was 60-70 ℃. Compared with free enzyme, the immobilized papain was fairly stable in a wide pH ( 3-9) range, and the thermal stability was also improved. The best way to store immobilized papain was in wet at 4℃ and air⁃tight container. The LH-HA immobilized papain could catalyze the hydrolysis of monoclonal antibody IgG to produce Fab and Fc fragments. The immobilized papain prepared in this work could be used in the production of antibody fragment in⁃dustrially.%以氨基载体原位固定化PEG相中的木瓜蛋白酶,获得了高固定化率(95.9%)和酶活回收率(38.9%)的固定化木瓜蛋白酶,解决了双水相分离纯化后成相聚合物和目的蛋白难以分离的问题。固定化木瓜蛋白酶的最适pH在7.0左右,最适温度处于60~70℃之间。相比游离木瓜蛋白酶,在广泛的pH区间内(3.0~9.0)固定化酶稳定性都较好,热稳定性也有改善。在4℃密闭容器内将固定化木瓜蛋白酶以湿润状态保存可以较好地保留其活性。 LH-HA固定化木瓜蛋白酶可以特异性地水解单克隆抗体IgG,制备Fab和Fc片段。

  14. Thermal decomposition studies of the polyhedral oligomeric silsesquioxane, POSSh, and when it is impregnated with the metallocene bis(eta5-cyclopentadienyl)zirconium (IV) dichloride or immobilized on silica.

    Science.gov (United States)

    Bianchini, D; Butler, I S; Barsan, M M; Martens, W; Frost, R L; Galland, G B; dos Santos, J H Z

    2008-11-01

    Thermal decomposition studies of the free polyhedral oligomeric silsesquioxane, POSSh, and when this compound has been impregnated with Cp2ZrCl2 (Cp = eta5-C5H5) or immobilized on SiO2 were conducted using infrared emission spectroscopy (IES) over a 100-1000 degrees C temperature range and by thermogravimetric analysis (TGA). The organic groups in POSS(h) apparently decompose thermally into Si-CH3, Si-H and other fragments. Upon impregnation with Cp2ZrCl2, however, a different thermal decomposition pathway was followed and new infrared emission bands appeared in the 1000-900 cm(-1) region suggesting the formation of Si-O-Zr moieties. When immobilized on SiO2 and subjected to thermal decomposition, the POSSh compound lost its organic groups and the inorganic structure remaining was incorporated into the SiO2 framework.

  15. Development and Validation of a Small Animal Immobilizer and Positioning System for the Study of Delivery of Intracranial and Extracranial Radiotherapy Using the Gamma Knife System.

    Science.gov (United States)

    Awan, Musaddiq J; Dorth, Jennifer; Mani, Arvind; Kim, Haksoo; Zheng, Yiran; Mislmani, Mazen; Welford, Scott; Yuan, Jiankui; Wessels, Barry W; Lo, Simon S; Letterio, John; Machtay, Mitchell; Sloan, Andrew; Sohn, Jason W

    2017-04-01

    The purpose of this research is to establish a process of irradiating mice using the Gamma Knife as a versatile system for small animal irradiation and to validate accurate intracranial and extracranial dose delivery using this system. A stereotactic immobilization device was developed for small animals for the Gamma Knife head frame allowing for isocentric dose delivery. Intercranial positional reproducibility of a reference point from a primary reference animal was verified on an additional mouse. Extracranial positional reproducibility of the mouse aorta was verified using 3 mice. Accurate dose delivery was validated using film and thermoluminescent dosimeter measurements with a solid water phantom. Gamma Knife plans were developed to irradiate intracranial and extracranial targets. Mice were irradiated validating successful targeted radiation dose delivery. Intramouse positional variability of the right mandible reference point across 10 micro-computed tomography scans was 0.65 ± 0.48 mm. Intermouse positional reproducibility across 2 mice at the same reference point was 0.76 ± 0.46 mm. The accuracy of dose delivery was 0.67 ± 0.29 mm and 1.01 ± 0.43 mm in the coronal and sagittal planes, respectively. The planned dose delivered to a mouse phantom was 2 Gy at the 50% isodose with a measured thermoluminescent dosimeter dose of 2.9 ± 0.3 Gy. The phosphorylated form of member X of histone family H2A (γH2AX) staining of irradiated mouse brain and mouse aorta demonstrated adjacent tissue sparing. In conclusion, our system for preclinical studies of small animal irradiation using the Gamma Knife is able to accurately deliver intracranial and extracranial targeted focal radiation allowing for preclinical experiments studying focal radiation.

  16. Student Collaboration in a Series of Integrated Experiments to Study Enzyme Reactor Modeling with Immobilized Cell-Based Invertase

    Science.gov (United States)

    Taipa, M. A^ngela; Azevedo, Ana M.; Grilo, Anto´nio L.; Couto, Pedro T.; Ferreira, Filipe A. G.; Fortuna, Ana R. M.; Pinto, Ine^s F.; Santos, Rafael M.; Santos, Susana B.

    2015-01-01

    An integrative laboratory study addressing fundamentals of enzyme catalysis and their application to reactors operation and modeling is presented. Invertase, a ß-fructofuranosidase that catalyses the hydrolysis of sucrose, is used as the model enzyme at optimal conditions (pH 4.5 and 45 °C). The experimental work involves 3 h of laboratory time…

  17. Comparison and evaluation of immobilization methods for preparing bacterial probes using acidophilic bioleaching bacteria Acidithiobacillus thiooxidans for AFM studies.

    Science.gov (United States)

    Diao, Mengxue; Taran, Elena; Mahler, Stephen M; Nguyen, Anh V

    2014-07-01

    We evaluated different strategies for constructing bacterial probes for atomic force microscopy studies of bioleaching Acidithiobacillus thiooxidans interacting with pyrite mineral surfaces. Of three available techniques, the bacterial colloidal probe technique is the most reliable and provides a versatile platform for quantifying true interactive forces between bioleaching microorganisms and mineral surfaces.

  18. Treating Wastewater With Immobilized Enzymes

    Science.gov (United States)

    Jolly, Clifford D.

    1991-01-01

    Experiments show enzymes are immobilized on supporting materials to make biocatalyst beds for treatment of wastewater. With suitable combination of enzymes, concentrations of various inorganic and organic contaminants, including ammonia and urea, reduced significantly.

  19. Nitrogenase activity of immobilized Azotobacter

    Energy Technology Data Exchange (ETDEWEB)

    Seyhan, E.; Kirwan, D.J.

    1979-02-01

    As part of a program to investigate the use of biological nitrogen fixation for fertilizer ammonia production, an investigation into the immobilization of the aerobic, nitrogen-fixing bacterium, Azotobacter vinelandii was undertaken. Immobilization was accomplished by adsorption onto an anionic exchange cellulose (Cellex E) with loadings as high as 10/sup 11/ cells/g resin. Immobilized cell preparations were tested under both batch and continuous-flow conditions. Nitrogenease activities as high as 4200 nmol/min g resin were observed as measured by the acetylene reduction assay. Immobilized cells retained their activity for as long as 117 hr in a continuous-flow reactor. Activity loss appeared to be related to the development of a variant strain.

  20. 1-step versus 2-step immobilization of alkaline phosphatase and bone morphogenetic protein-2 onto implant surfaces using polydopamine.

    Science.gov (United States)

    Nijhuis, Arnold W G; van den Beucken, Jeroen J J P; Boerman, Otto C; Jansen, John A; Leeuwenburgh, Sander C G

    2013-08-01

    Immobilization of biomolecules onto implant surfaces is highly relevant in many areas of biomaterial research. Recently, a 2-step immobilization procedure was developed for the facile conjugation of biomolecules onto various surfaces using self-polymerization of dopamine into polydopamine. In the current study, a 1-step polydopamine-based approach was applied for alkaline phosphatase (ALP) and bone morphogenetic protein-2 (BMP-2) immobilization, and compared to the conventional 2-step polydopamine-based immobilization and plain adsorption. To this end, ALP and BMP-2 were immobilized onto titanium and polytetrafluoroethylene (PTFE) substrates. The absolute quantity and biological activity of immobilized ALP were assessed quantitatively to compare the three types of immobilization. Plain adsorption of both ALP and BMP-2 was inferior to both polydopamine-based immobilization approaches. ALP was successfully immobilized onto titanium and PTFE surfaces via the 1-step approach, and the immobilized ALP retained its enzymatic activity. Using the 1-step approach, the amount of immobilized ALP was increased twofold to threefold compared to the conventional 2-step immobilization process. In contrast, more BMP-2 was immobilized using the conventional 2-step immobilization approach. Retention of ALP and BMP-2 was measured over a period of 4 weeks and was found to be similar for the 1-step and 2-step methods and far superior to the retention of adsorbed biomolecules due to the formation of covalent linkages between catechol moieties and immobilized proteins. The biological behavior of ALP and BMP-2 coatings immobilized using polydopamine (1- and 2-step) as well as adsorption was assessed by culturing rat bone marrow cells, which revealed that the cell responses to the various experimental groups were not statistically different. In conclusion, the 1-step polydopamine-based immobilization method was shown to be more efficient for immobilization of ALP, whereas the conventional 2

  1. 16s rRNA Identification of Pediococcus spp. from Broiler and Studies of Adherence Ability on Immobilized Mucus

    Directory of Open Access Journals (Sweden)

    Ema Damayanti

    2015-11-01

    Full Text Available The objectives of this research were to study taxonomical status of lactic acid bacteria (LAB isolated from broiler and adherence ability on mucus in vitro. Molecular analysis was performed by analyzing 16S rRNA gene using universal primer. The adherence assay on mucus was carried out using microplate method with total plate count (TPC, absorbance (A550 and confirmed by scanning electron microscopy (SEM. The results of this studies revealed that three of LAB isolates have closed relation to Pediococcus acidilactici (99.9% species.Three isolates of P. acidilactici have adherence ability on broiler mucus higher than that on porcine mucin with an adherence percentage of 55.5% versus 50.8% and absorbance A550 of 0.061 versus 0.051, respectively. The highest adherence ability showed by P. acidilactici R02 with adherence percentage was 59.3% and absorbance A550 = 0.068. Adherence on mucus were affected by the addition of 3 g/l of gastric juice and 0.3% (b/v of bile salt. Adherence analysis using SEM also showed that the adherence on broiler mucus was higher than the adherence on porcine mucin. Altogether this adherence studies, suggest that three isolates of P. acidilactici LAB were capable of colonizing host intestinal mucus in vitro as important property to be promising probiotic bacteria for broiler.Key words : adherence, broiler, Pediococcus, mucus, 16S rRNA

  2. The NanoChitosan thin film: a new portable support for immobilization of Acid phosphatase

    Directory of Open Access Journals (Sweden)

    Mohammad Fahiminiaa

    2016-12-01

    Full Text Available Immobilization can enhance the economic value of enzymes and helps reusing and improves their stability. For the first time, acid phosphatase from Phaseolus vulgaris seeds was immobilized on chitosan nanoparticles thin films (CSNPs-TFs. Maximum immobilization yield of NanoChitosan thin films with 1×1cm dimensionand 3±0.1 mg (one block was ∼84%. In comparison with free enzyme, the activity of acid phosphatase was decreased 16% after immobilization. Immobilized acid phosphatase retained 51 % activity upon storage for 90 days at 4 °C and could be reused for 20 cycles with more than 88 % activity retention. The present study, immobilization of acid phosphatase on CSNPs-TF, is a new promising method which could explore a new biocompatible and eco-friendly material in enzyme immobilization, water treatment application as well as new adsorbent for occupational and environmental monitoring.

  3. Enhanced starch hydrolysis using α-amylase immobilized on cellulose ultrafiltration affinity membrane.

    Science.gov (United States)

    Konovalova, Viktoriia; Guzikevich, Kateryna; Burban, Anatoliy; Kujawski, Wojciech; Jarzynka, Karolina; Kujawa, Joanna

    2016-11-05

    In order to prepare ultrafiltration membranes possessing biocatalytic properties, α-amylase has been immobilized on cellulose membranes. Enzyme immobilization was based on a covalent bonding between chitosan and a surface of cellulose membrane, followed by an attachment of Cibacron Blue F3G-A dye as affinity ligand. Various factors affecting the immobilization process, such as enzyme concentration, pH of modifying solution, zeta-potential of membrane surface, and stability of immobilized enzyme were studied. The applicability of immobilized α-amylase has been investigated in ultrafiltration processes. The immobilization of α-amylase on membrane surface allows to increase the value of mass transfer coefficient and to decrease the concentration polarization effect during ultrafiltration of starch solutions. The enzyme layer on the membrane surface prevents a rapid increase of starch concentration due to the amylase hydrolysis of starch in the boundary layer. The presented affinity immobilization technique allows also for the regeneration of membranes from inactivated enzyme.

  4. POTENTIAL APPLICATIONS OF CHITOSAN NANOPARTICLES AS NOVEL SUPPORT IN ENZYME IMMOBILIZATION

    Directory of Open Access Journals (Sweden)

    Hoda Jafarizadeh Malmiri

    2012-01-01

    Full Text Available Chitosan is an attractive natural biopolymer from renewable resources with the presence of reactive amino and hydroxyl functional groups in its structure. Due to the good biocompatibility of chitosan, it can be used in magnetic-field assisted drug delivery, enzyme or cell immobilization and many other industrial applications. In the past decade, nanotechnology has been a considerable research interest in the area of preparation of immobilized enzyme carriers. This study looks at characteristics and applications of chitosan and chitosan nanoparticles and their potentials as suitable supports for enzyme immobilization. Results indicated that activity of immobilized enzymes and performance of enzyme immobilization onto chitosan nanoparticles are higher than chitosan macro and microparticles. As compared to other biopolymers nanoparticles, application of chitosan nanoparticles to immobilize enzymes strongly increases stability of immobilized enzymes and their easy separability from the reaction mixture at the end of the biochemical process.

  5. Comparison study on photocatalytic oxidation of pharmaceuticals by TiO2-Fe and TiO2-reduced graphene oxide nanocomposites immobilized on optical fibers.

    Science.gov (United States)

    Lin, Lu; Wang, Huiyao; Jiang, Wenbin; Mkaouar, Ahmed Radhi; Xu, Pei

    2017-03-08

    Incorporating reduced graphene oxide (rGO) or Fe(3+) ions in TiO2 photocatalyst could enhance photocatalytic degradation of organic contaminants in aqueous solutions. This study characterized the photocatalytic activities of TiO2-Fe and TiO2-rGO nanocomposites immobilized on optical fibers synthesized by polymer assisted hydrothermal deposition method. The photocatalysts presented a mixture phase of anatase and rutile in the TiO2-rGO and TiO2-Fe nanocomposites. Doping Fe into TiO2 particles (2.40eV) could reduce more band gap energy than incorporating rGO (2.85eV), thereby enhancing utilization efficiency of visible light. Incorporating Fe and rGO in TiO2 decreased significantly the intensity of TiO2 photoluminescence signals and enhanced the separation rate of photo-induced charge carriers. Photocatalytic performance of the synthesized nanocomposites was measured by the degradation of three pharmaceuticals under UV and visible light irradiation, including carbamazepine, ibuprofen, and sulfamethoxazole. TiO2-rGO exhibited higher photocatalytic activity for the degradation of pharmaceuticals under UV irradiation, while TiO2-Fe demonstrated more suitable for visible light oxidation. The results suggested that the enhanced photocatalytic performance of TiO2-rGO could be attributed to reduced recombination rate of photoexcited electrons-hole pairs, but for TiO2-Fe nanocomposite, narrower band gap would contribute to increased photocatalytic activity.

  6. Antimony (Sb) and lead (Pb) in contaminated shooting range soils: Sb and Pb mobility and immobilization by iron based sorbents, a field study.

    Science.gov (United States)

    Okkenhaug, Gudny; Grasshorn Gebhardt, Karl-Alexander; Amstaetter, Katja; Bue, Helga Lassen; Herzel, Hannes; Mariussen, Espen; Rossebø Almås, Åsgeir; Cornelissen, Gerard; Breedveld, Gijs D; Rasmussen, Grete; Mulder, Jan

    2016-04-15

    Small-arm shooting ranges often receive a significant input of lead (Pb), copper (Cu) and antimony (Sb) from ammunition. The goal of the present study was to investigate the mobility, distribution and speciation of Pb and Sb pollution under field conditions in both untreated and sorbent-amended shooting range soil. Elevated Sb (19-349μgL(-1)) and Pb (7-1495μgPbL(-1)) concentrations in the porewater of untreated soil over the four-year test period indicated a long-term Sb and Pb source to the adjacent environment in the absence of remedial measures. Mixing ferric oxyhydroxide powder (CFH-12) (2%) together with limestone (1%) into the soil resulted in an average decrease of Sb and Pb porewater concentrations of 66% and 97%, respectively. A similar reduction was achieved by adding 2% zerovalent iron (Fe°) to the soil. The remediation effect was stable over the four-year experimental period indicating no remobilization. Water- and 1M NH4NO3-extractable levels of Sb and Pb in field soil samples indicated significant immobilization by both treatments (89-90% for Sb and 89-99% for Pb). Results from sequential extraction analysis indicate fixation of Sb and Pb in less accessible fractions like amorphous iron oxides or even more crystalline and residual mineral phases, respectively. This work shows that amendment with Fe-based sorbents can be an effective method to reduce the mobility of metals both in cationic and anionic form in polluted shooting range soil.

  7. Immunosuppressive agent leflunomide: a SWNTs-immobilized dihydroortate dehydrogenase inhibitory effect and computational study of its adsorption properties on zigzag single walled (6,0) carbon and boron nitride nanotubes as controlled drug delivery devices.

    Science.gov (United States)

    Raissi, Heidar; Mollania, Fariba

    2014-06-02

    Leflunomide [HWA 486 or RS-34821, 5-methyl-N-(4trifluoromethylphenyl)-4-isoxazole carboximide] is an immunosuppressive agent effective in the treatment of rheumatoid arthritis. Dihydroortate dehydrogenase (DHODH, EC 1.3.3.1) immobilization on the nanotubes was carried out and biochemical characterization of free and immobilized enzyme was determined. In comparison with free enzyme, the immobilized DHODH showed improved stability and reusability for investigation of inhibition pattern of drugs such as leflunomide. The experimental data showed that, DHODH was inhibited by the active metabolite of leflunomide (RS-61980) with a Ki and KI of 0.82 and 0.06 mM, respectively. Results exhibited mixed-type inhibition kinetics towards dihydroorotate as a substrate in the free and immobilized enzyme. Furthermore, the behavior of anticancer drug leflunomide adsorbed on the external surface of zigzag single walled (6,0) carbon and boron nitride nanotubes (SWCNT and SWBNNT) was studied by means of DFT calculations at the B3LYP/6-31G(*) level of theory. The larger adsorption energies and charges transfer showed that the adsorption of leflunomide onto SWBNNT is more stable than that the adsorption of leflunomide onto SWCNT. Frontier molecular orbitals (HOMO and LUMO) suggest that adsorption of leflunomide onto SWBNNT behave as charge transfer compounds with leflunomide as an electron donor and SWBNNT as an electron acceptor. Thus, nanotubes (NTs) have been proposed and actively explored as multipurpose innovative carriers for drug delivery and diagnostic application. The AIM theory has been also applied to analyze the properties of the bond critical points: their electron densities and their laplacians. Also, the natural bond orbital (NBO) calculations were performed to derive natural atomic orbital occupancies, and partial charges of the interacting atoms in the equilibrium tube-molecule distance.

  8. N-15 NMR study of the immobilization of 2,4- and 2,6-dinitrotoluene in aerobic compost

    Science.gov (United States)

    Thorn, K.A.; Pennington, J.C.; Kennedy, K.R.; Cox, L.G.; Hayes, C.A.; Porter, B.E.

    2008-01-01

    Large-scale aerobic windrow composting has been used to bioremediate washout lagoon soils contaminated with the explosives TNT (2,4,6- trinitrotoluene) and RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine) at several sites within the United States. We previously used 15N NMR to investigate the reduction and binding of T15NT in aerobic bench -scale reactors simulating the conditions of windrow composting. These studies have been extended to 2,4-dinitrotoluene (2,4DNT) and 2,6-dinitrotoluene (2,6DNT), which, as impurities in TNT, are usually present wherever soils have been contaminated with TNT. Liquid-state 15N NMR analyses of laboratory reactions between 4-methyl-3-nitroaniline-15N, the major monoamine reduction product of 2,4DNT, and the Elliot soil humic acid, both in the presence and absence of horseradish peroxidase, indicated that the amine underwent covalent binding with quinone and other carbonyl groups in the soil humic acid to form both heterocyclic and non-heterocyclic condensation products. Liquid-state 15N NMR analyses of the methanol extracts of 20 day aerobic bench-scale composts of 2,4-di-15N-nitrotoluene and 2,6-di-15N-nitrotoluene revealed the presence of nitrite and monoamine, but not diamine, reduction products, indicating the occurrence of both dioxygenase enzyme and reductive degradation pathways. Solid-state CP/MAS 15N NMR analyses of the whole composts, however, suggested that reduction to monoamines followed by covalent binding of the amines to organic matter was the predominant pathway. ?? 2008 American Chemical Society.

  9. 介孔二氧化硅制备固定化菠萝蛋白酶的研究%Study on mesoporous silica immobilization of bromelain

    Institute of Scientific and Technical Information of China (English)

    韩志萍; 黄茂芳; 张文华; 罗荣琼; 静玮

    2013-01-01

    Scanning electron microscopy and transmission electron microscopy were used to characterize mesoporous silica,which was applied in preparation of immobilized bromelain.There are a number of clear superiority with simple process,mild condition and convenient operation.The concentrations of enzyme,pH and reaction time on the immobilized bromelain activity were investigeted.When conditions of the reaction were enzyme concentration of 25mg/mL,pH5.0,fixed time 22h,immobilized enzyme activity was 603U/g.lmmobilized bromelain in water bath 50℃ for 60min,the enzyme activity remained more than 92%.The result indicated immobilized enzyme had higher thermal stability than esolvase.When the immobilized enzyme was continuously operated for three times,the relative enzyme activity still amounted to 38.5% for the third time.The conclusion showed that the bromelain molecules and vectors had a strong physical adsorption and the immobilized bromelain had certain reusability,though the activity was gradually declined.%采用经扫描电镜和透射电镜表征的介孔二氧化硅制备固定化菠萝蛋白酶,具有工艺简便、条件温和及操作方便的特点.考察了给酶量、pH和时间对固定化菠萝蛋白酶活力的影响,在酶量25mg/mL、pH5.0、固定化时间22h时,固定化酶的酶活为603 U/g.介孔二氧化硅固定的菠萝蛋白酶在50℃水浴60min后,固定化酶的活力保持在92%以上,说明固定化酶的热稳定性较高.该固定酶持续操作三次后,使用活性逐渐衰减,但第3次相对酶活仍然达38.5%,反映了菠萝蛋白酶分子与载体有较强的物理吸附作用而且固定的菠萝蛋白酶有一定的可重复使用性.

  10. 漆酶的形态特性表征及固定化研究%Study on morphological characterization and immobilization of laccase

    Institute of Scientific and Technical Information of China (English)

    张安龙; 郗文君; 杜飞; 周丹妮; 杨楠

    2016-01-01

    The use of immobilized laccase in papermaking wastewater treatment can signifi-cantly reduce the residual lignin content in water .The use of SEM ,XRD ,laser particle size , energy spectrum analysis can provide an effective evaluation method for laccase immobiliza-tion .The molecular size of the laccase was mainly concentrated in the 11 .482~19 .953 μm . The principle for immobilization of laccase by sodium alginate and PVA were internal embed-ding and surface adsorption respectively .The particle size and the number of the enzyme molecules in the sodium alginate embedding method were large and fixed firmly and not easy to fall off ;Epoxidized PVA immobilized laccase tended to absorb small particles and vulnera-ble to environmental impact ,so the fixed affect was poor .Under the same activity ,the crys-tallinity of the immobilized laccase by sodium alginate was higher than that of the PVA ad-sorption method .The qualitative analysis of the sulfur and sodium elements confirmed the effect of laccase immobilization .%使用固定化漆酶进行造纸废水深度处理可显著减少水中残留木素含量,运用SEM 、X RD、激光粒度、能谱等分析手段,可提供一种关于漆酶固定化效果的有效评价方法.漆酶分子粒径主要集中在11.482~19.953μm ,海藻酸钠法及环氧化P V A法对漆酶的固定方式分别为内部包埋和表面吸附.在海藻酸钠包埋法中,固定的酶分子粒径大、数量多、固定牢固而不易脱落;环氧化PV A趋向于吸附小粒径的漆酶分子、易受环境影响,固定效果差.在相同活力下,海藻酸钠固定化漆酶结晶度高于PV A吸附法.硫、钠元素的定性,证实了漆酶的固定化效果.

  11. Chlorpyrifos Detection by Piezoelectric Biosensor Based on Acetylcholinesterase Immobilization

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Acetylcholinesterase (AChE) was immobilized on multilayer films assembled by poly diallyldimethylammonium chloride (PDDA) and ι-carrageenan (IC) on silver-coated crystal electrode surfaces to detect the chlorpyrifos belonging to the organophosphates pesticide.Mass sensitive quartz crystal microbalance (QCM) was used to study the effect of AChE concentration and pH of phosphate buffer solution on immobilized acetylcholinesterase.The optimized conditions were as follows: pH was 6.0 which was near isoelectric ...

  12. Status of plutonium ceramic immobilization processes and immobilization forms

    Energy Technology Data Exchange (ETDEWEB)

    Ebbinghaus, B.B.; Van Konynenburg, R.A. [Lawrence Livermore National Lab., CA (United States); Vance, E.R.; Jostsons, A. [Australian Nuclear Science and Technology Organization, Menai (Australia)] [and others

    1996-05-01

    Immobilization in a ceramic followed by permanent emplacement in a repository or borehole is one of the alternatives currently being considered by the Fissile Materials Disposition Program for the ultimate disposal of excess weapons-grade plutonium. To make Pu recovery more difficult, radioactive cesium may also be incorporated into the immobilization form. Valuable data are already available for ceramics form R&D efforts to immobilize high-level and mixed wastes. Ceramics have a high capacity for actinides, cesium, and some neutron absorbers. A unique characteristic of ceramics is the existence of mineral analogues found in nature that have demonstrated actinide immobilization over geologic time periods. The ceramic form currently being considered for plutonium disposition is a synthetic rock (SYNROC) material composed primarily of zirconolite (CaZrTi{sub 2}O{sub 7}), the desired actinide host phase, with lesser amounts of hollandite (BaAl{sub 2}Ti{sub 6}O{sub 16}) and rutile (TiO{sub 2}). Alternative actinide host phases are also being considered. These include pyrochlore (Gd{sub 2}Ti{sub 2}O{sub 7}), zircon (ZrSiO{sub 4}), and monazite (CePO{sub 4}), to name a few of the most promising. R&D activities to address important technical issues are discussed. Primarily these include moderate scale hot press fabrications with plutonium, direct loading of PuO{sub 2} powder, cold press and sinter fabrication methods, and immobilization form formulation issues.

  13. Preparation of Polyphosphazene Hydrogels for Enzyme Immobilization

    Directory of Open Access Journals (Sweden)

    Yue-Cheng Qian

    2014-07-01

    Full Text Available We report on the synthesis and application of a new hydrogel based on a methacrylate substituted polyphosphazene. Through ring-opening polymerization and nucleophilic substitution, poly[bis(methacrylatephosphazene] (PBMAP was successfully synthesized from hexachlorocyclotriphosphazene. By adding PBMAP to methacrylic acid solution and then treating with UV light, we could obtain a cross-linked polyphosphazene network, which showed an ultra-high absorbency for distilled water. Lipase from Candida rugosa was used as the model lipase for entrapment immobilization in the hydrogel. The influence of methacrylic acid concentration on immobilization efficiency was studied. Results showed that enzyme loading reached a maximum of 24.02 mg/g with an activity retention of 67.25% when the methacrylic acid concentration was 20% (w/w.

  14. Ethanol fermentation by immobilized cells of Zymomonas mobilis

    Energy Technology Data Exchange (ETDEWEB)

    Grote, W.

    1985-01-01

    Previous studies have shown that immobilized yeast cell cultures have commercial potential for fuel ethanol production. In this study the suitability of strains of Z. mobilis for whole cell immobilization was investigated. Experiments revealed that immobilization in Ca-alginate or K-carrageenan gel or use of flocculating strains was effective for ethanol production at relatively high productivities. Two laboratory size reactors were designed and constructed. These were a compartmented multiple discshaft column and a tower fermentor. Results of this work supported other studies that established that growth and fermentation could be uncoupled. The data indicated that specific metabolic rates were dependent on the nature of the fermentation media. The addition of lactobacilli to Z. mobilis continuous fermentations had only a transient effect, and was unlikely to affect an immobilized Z. mobilis process. With 150 gl/sup -1/ glucose media and a Z. mobilis ZM4 immobilized cell reactor, a maximum volumetric ethanol productivity of 55 gl/sup -1/h/sup -1/ was obtained. The fermentation of sucrose media or sucrose-based raw materials (molasses, cane juice, synthetic mill liquor) by immobilized Z. mobilis ZM4 revealed a pattern of rapid sucrose hydrolysis, preferential glucose utilization and the conversion of fructose to the undesirable by-products levan and sorbitol.

  15. Effect of kinesthetic illusion induced by visual stimulation on muscular output function after short-term immobilization.

    Science.gov (United States)

    Inada, Toru; Kaneko, Fuminari; Hayami, Tatsuya

    2016-04-01

    Kinesthetic illusions by visual stimulation (KiNVIS) enhances corticomotor excitability and activates motor association areas. The purpose of this study was to investigate the effect of KiNVIS induction on muscular output function after short-term immobilization. Thirty subjects were assigned to 3 groups: an immobilization group, with the left hand immobilized for 12h (immobilization period); an illusion group, with the left hand immobilized and additionally subjected to KiNVIS of the immobilized part during the immobilization period; and a control group with no manipulation. The maximum voluntary contraction (MVC), fluctuation of force (force fluctuation) during a force modulation task, and twitch force were measured both before (pre-test) and after (post-test) the immobilization period. Data were analyzed by performing two-way (TIME×GROUP) repeated measures ANOVA. The MVC decreased in the immobilization group only (pre-test; 37.8±6.1N, post-test; 32.8±6.9N, p<0.0005) after the immobilization period. The force fluctuation increased only in the immobilization group (pre-test; 2.19±0.54%, post-test; 2.78±0.87%, p=0.007) after the immobilization period. These results demonstrate that induction of KiNVIS prevents negative effect on MVC and force fluctuation after 12h of immobilization.

  16. 固定化菌剂处理含油废水的试验研究%Experimental Study on Treatment of Oil Wastewater with Immobilized Agents

    Institute of Scientific and Technical Information of China (English)

    湛美; 陈丹

    2011-01-01

    The removal rate of CODcx of oil wastewater affected by immobilized agents inoculums, aeration intensity and temperature was discussed. The results indicated that four immobilized microbial inoculums had good removal ability for CODcx of oil wastewater in condition of suitable intensity and way of aeration, 3℃, and 10% of embedding products.%探讨了固定化菌剂的接种量、曝气强度及温度等因素对废水中CODer去除率的影响.试验结果表明:在采用适当的曝气方式和曝气强度下,温度为30℃时,采用10%的固定化颗粒接种量,4种固定化产品对含油废水中CODer降解均有较好的效果.

  17. Study on Immobilization of Acetylcholinesterase with Filter Paper Coated with Chitosan%滤纸壳聚糖膜固定乙酰胆碱酯酶的研究

    Institute of Scientific and Technical Information of China (English)

    郭尽力; 姜爱莉; 于贞; 郑舒文

    2012-01-01

    [目的]探索滤纸壳聚糖膜固定乙酰胆碱酯酶( AChE)的最佳条件.[方法]以滤纸壳聚糖膜为我体,戊二醛为交联剂,牛血清白蛋白( BSA)为保护剂,进行AChE的固定.并对固定化酶的理化性质进行研究.[结果]固定AChE的最佳条件为将50μl150 U/mlAChE液,50 μl 5%(V/V)戊二醛溶液,100μl1%(W/W) BSA,pH 8.0的0.2 mol/L的PBS缓冲液配制成1 ml酶液,滤纸壳聚糖膜浸于该酶液4℃固定8h.固定化酶的最适反应温度为37℃,最适pH为8.0,能够重复利用4次以上.[结论]该研究为利用AChE快速检测蔬菜水果中有机磷农药残留提供了理论依据.%[Objective] The aim was to explore the optimum immobilized conditions of acetylcholinesterase on filter paper coated with chitosan. [Method] Acetylcholinesterase was immobilized on filter paper coated with chitosan using glutaraldehyde as cross-linking reagent, bovine serum albumin as protective agent. And the physical and chemical properties of the immobilized enzyme were studied. [Result] The optimal immobilized conditions were as follows: 1 ml solution was prepared with 50 μl 150 U/ml acetylcholinesterase solution, 50 μl 5% ( V/V) glutaraldehyde, 100 μl 1% (W/W) BSA and 0.2 mol/L phosphate buffer(pH 8.0) , and then the filter paper coated with chitosan was immersed for 8 h at 4 ℃.. The optimum temperature of the immobilized acetylcholinesterase was 37 ℃ , the optimum pH was 8.0, and its could be reused four times. [ Conclusion] The study provides a theory basis for rapid determination of organophosphorus pesticide residues in vegetables and fruits.

  18. Electrochemical quartz crystal microbalance studies on enzymatic specific activity and direct electrochemistry of immobilized glucose oxidase in the presence of sodium dodecyl benzene sulfonate and multiwalled carbon nanotubes.

    Science.gov (United States)

    Su, Yuhua; Xie, Qingji; Chen, Chao; Zhang, Qingfang; Ma, Ming; Yao, Shouzhuo

    2008-01-01

    The electrochemical quartz crystal microbalance (EQCM) technique was utilized to monitor in situ the adsorption of glucose oxidase (GOD) and the mixture of GOD and sodium dodecyl benzene sulfonate (SDBS) onto Au electrodes with and without modification of multiwalled carbon nanotubes (MWCNTs) or SDBS/MWCNTs composite, and the relationship between enzymatic specific activity (ESA) and direct electrochemistry of the immobilized GOD was quantitatively evaluated for the first time. Compared with the bare gold electrode at which a little GOD was adsorbed and the direct electrochemistry of the adsorbed GOD was negligible, the amount and electroactivity of adsorbed GOD were greatly enhanced when the GOD was mixed with SDBS and then adsorbed onto the SDBS/MWCNTs modified Au electrode. However, the ESA of the adsorbed GOD was fiercely decreased to only 16.1% of the value obtained on the bare gold electrode, and the portion of adsorbed GOD showing electrochemical activity exhibited very low enzymatic activity, demonstrating that the electroactivity and ESA of immobilized GOD responded oppositely to the presence of MWCNTs and SDBS. The ESA results obtained from the EQCM method were well supported by conventional UV-vis spectrophotometry. The direct electrochemistry of redox proteins including enzymes as a function of their biological activities is an important concern in biotechnology, and this work may have presented a new and useful protocol to quantitatively evaluate both the electroactivity and ESA of trace immobilized enzymes, which is expected to find wider applications in biocatalysis and biosensing fields.

  19. Immobilizing PEO-PPO-PEO triblock copolymers on hydrophobic surfaces and its effect on protein and platelet: a combined study using QCM-D and DPI.

    Science.gov (United States)

    Jin, Jing; Huang, Fujian; Hu, Yu; Jiang, Wei; Ji, Xiangling; Liang, Haojun; Yin, Jinghua

    2014-11-01

    Dual polarization interferometry was used to monitor the immobilization dynamics of four Pluronics on hydrophobic surfaces and to elucidate the effect of Pluronic conformation on protein adsorption. The proportion of hydrophobic chain segments and not the length of the hydrophobic chain can influence the chain densities of the Pluronics. The immobilized densities of the Pluronics resulted from competition between the hydration of polyethylene oxide (PEO) in the aqueous solution and the hydrophobic interaction of polypropylene oxide on the substrate. P-123 obtained the largest graft mass (2.89±0.25 ng/mm2) because of the dominant effect of hydrophobic interactions. Hydrophobic segments of P-123 were anchored slowly and step-wise on the C18 substrate. P-123 exhibited the largest hydrophobic chain segment proportion (propylene oxide/ethylene oxide=3.63) and formed a brush chain conformation, indicating excellent protein and platelet resistance. The result of quartz crystal microbalance with dissipation further confirmed that the PEO conformation in P-123 on the substrate exhibited a relatively extended brush chain, and that L-35 showed relatively loose and pancake-like structures. The PEO in P-123 regulated the conformation to maintain the native conformation and resist the adsorption of bovine serum albumin (BSA). Thus, the hemocompatibilities of the immobilized Pluronics were influenced by the proportion of hydrophobic chain segments and their PEO conformations.

  20. Comparative study of bio-ethanol production from mahula (Madhuca latifolia L.) flowers by Saccharomyces cerevisiae cells immobilized in agar agar and Ca-alginate matrices

    Energy Technology Data Exchange (ETDEWEB)

    Behera, Shuvashish; Mohanty, Rama Chandra [Department of Botany, Utkal University, Vani Vihar, Bhubaneswar 751004, Orissa (India); Kar, Shaktimay; Ray, Ramesh Chandra [Microbiology Laboratory, Central Tuber Crops Research Institute (Regional Centre), Bhubaneswar 751019, Orissa (India)

    2010-01-15

    Batch fermentation of mahula (Madhuca latifolia L., a tree commonly found in tropical rain forest) flowers was carried out using immobilized cells (in agar agar and calcium alginate) and free cells of Saccharomyces cerevisiae. The ethanol yields were 151.2, 154.5 and 149.1 g kg{sup -1} flowers using immobilized (in agar agar and calcium alginate) and free cells, respectively. Cell entrapment in calcium alginate was found to be marginally superior to those in agar agar (2.2% more) as well as over free cell (3.5% more) as regard to ethanol yield from mahula flowers is concerned. Further, the immobilized cells were physiologically active at least for three cycles [150.6, 148.5 and 146.5 g kg{sup -1} (agar agar) and 152.8, 151.5 and 149.5 g kg{sup -1} flowers (calcium alginate) for first, second and third cycle, respectively] of ethanol fermentation without apparently lowering the productivity. Mahula flowers, a renewable, non-food-grade cheap carbohydrate substrate from non-agricultural environment such as forest can serve as an alternative to food grade sugar/starchy crops such as maize, sugarcane for bio-ethanol production. (author)

  1. Rat hindlimb joint immobilization with acrylic resin orthoses

    Directory of Open Access Journals (Sweden)

    C.A. da Silva

    2006-07-01

    Full Text Available The objective of the present study was to propose an orthosis of light material that would be functional for the animal and that would maintain only the ankle joint immobilized. Male Wistar rats (3 to 4 months old, 250-300 g were divided into 2 groups (N = 6: control and immobilized for 7 days. Rats were anesthetized with sodium pentobarbital (40 mg/kg weight and the left hindlimb was immobilized with the orthoses composed of acrylic resin model, abdominal belt and lateral supports. The following analyses were performed: glycogen content of the soleus, extensor digitorum longus, white gastrocnemius, red gastrocnemius, and tibialis anterior muscles by the phenol sulfuric method, and the weight, fiber area and intramuscular connective tissue of the soleus by the planimetric system. Data were analyzed statistically by the Kolmogorov-Smirnov, Student t and Wilcoxon tests. Immobilization decreased glycogen in all muscles (P < 0.05; soleus: 31.6%, white gastrocnemius: 56.6%, red gastrocnemius: 39%, extensor digitorum longus: 41.7%, tibialis anterior: 45.2% in addition to reducing soleus weight by 34% (P < 0.05. Furthermore, immobilization promoted reduction of the fiber area (43%, P < 0.05 and increased the connective tissue (200%, P < 0.05. The orthosis model was efficient comparing with another alternative immobilization model, like plaster casts, in promoting skeletal muscle alterations, indicating that it could be used as a new model in other studies related to muscle disuse.

  2. Study of immobilization of papain with chitosan/lecithin microspheres%壳聚糖/卵磷脂复合微球固定木瓜蛋白酶的研究

    Institute of Scientific and Technical Information of China (English)

    何秋星; 王学文; 宋平

    2011-01-01

    以壳聚糖和卵磷脂为材料,采用乳化-交联法制备壳聚糖/卵磷脂复合微球,并用光学显微镜和红外光谱对微球进行表征;再以此微球作为载体固定木瓜蛋白酶,以固定率为指标,应用正交试验法优选固定化酶的制备工艺,并对固定化酶的半衰期、米氏常数(Km)、操作稳定性进行研究.结果表明,制备的壳聚糖/卵磷脂复合微球呈完整的圆球形或椭球形;固定化酶的优化制备工艺为:m(壳聚糖)=250 mg,m(壳聚糖):m(卵磷脂)=1:2,V(戊二醛水溶液)=300 μL,m(木瓜蛋白酶)=20 mg,此时制备的固定化酶的固定率达61.94%,半衰期为86.27 h,米氏常数为6.37 mg/mL,固定化酶有很好的操作稳定性.%Chitosan ( CS) /lecithin microspheres were prepared with the CS and lecithin by emulsion -crosslinking method. The microspheres were characterized by optical microscope and IR,and used as carrier for immobilization of papain. Taking the extent of immobilization of papain on the microspheres as index, orthogonal test was carried out to optimize the preparation process. Half life period, Michaelis constant ( Km ) and operation stability of immobilized papain were studied. The results showed that the shape of CS/lecithin microspheres was complete spherical or ellipsoidal. The optimum conditions were; m ( CS ) = 250 mg, m(CS): m(lecithin) = 1:2, V(glutaraldehyde aqueous solution) =300 |xL,m(papain) =20 mg. In this case, percentage of immobilized papain achieves 61. 94% ;half life period achieves 86. 27 h;£m =6. 37 mg/mL;the immobilized papain had a good operational stability.

  3. 固定化木瓜蛋白酶水解大豆乳清废水研究%Study on immobilized papain enzymetic hydrolyzing soybean isolated protein whey wastewater

    Institute of Scientific and Technical Information of China (English)

    杨頔; 张多英; 石彦国

    2013-01-01

    大豆乳清废水中含有高浓度的ROD5和COD,难生物降解,且易发生腐败.为提高大豆乳清废水的可生物降解性,采用固定化木瓜蛋白酶水解大豆乳清废水,并研究最佳工艺条件.固定化工艺中以戊二醛为交联剂,壳聚糖为载体.固定化木瓜蛋白酶水解大豆乳清废水的最佳工艺条件为:在55℃、pH为8.0、加酶量为3%的条件下,水解2.5 h后,底物水解度可达36.48%.废水中BOD5/COD比值可达0.7以上,废水的可生化性程度显著提高,对固定化酶进行回收,酶活力回收率可达97%,可以有效重复使用.%The soybean whey wastewater contains high concentration of BOD5 and COD.It is hard to biodegraded and easy to decay.The purpose of the study is to define the proper process of soybean isolated protein hydrolyzed by immobilized papain enzyme.Glutaraldehyde was used as cross linking agent,and chitosan was used as carder in this experiment.The results showed that the optimal hydrolyzing conditions of immobilized papain enzyme was as follows:55 ℃,pH 8.0,enzyme dosage was 3%,after 2.5hours hydrolysis,protein hydrolysis degree could be 36.48%.Ratio of BOD5 to COD was above 0.7.Biodegradability of soybean isolated protein whey wastewater could be improved.The immobilized enzyme could be reused.The recovered immobilized enzyme activity was 97% of raw immobilized enzyme.

  4. Immobilization and release study of a red alga extract in hydrogel membranes; Estudo da incorporacao e liberacao de um extrato de algas vermelhas em membranas de hidrogel

    Energy Technology Data Exchange (ETDEWEB)

    Amaral, Renata Hage

    2009-07-01

    In pharmaceutical technology hydrogel is the most used among the polymeric matrices due to its wide application and functionality, primarily in drug delivery system. In view of the large advance innovations in cosmetic products, both through the introduction of new active agents as the matrices used for its controlled release, the objective of this study was to evaluate the release and immobilization of a natural active agent, the Arct'Alg in hydrogel membranes to obtain a release device for cosmetics. Arct'Alg is an aqueous extract which has excellent anti-oxidant, lipolytic, anti-inflammatory and cytostimulant action. Study on mechanical and physical-chemical properties and biocompatibility in vitro of hydrogel membranes of poly(vinyl-2- pyrrolidone) (PVP) and poly(vinyl alcohol) (PVA) obtained by ionizing radiation crosslinking have been performed. The physical-chemical characterization of polymeric matrices was carried out by gel fraction and swelling tests and biocompatibility by in vitro test of cytotoxicity by using the technique of neutral red incorporation. In the gel fraction test, both the PVP and PVA hydrogel showed a high crosslinking degree. The PVP hydrogel showed a greater percentage of swelling in relation to PVA and the cytotoxicity test of the hydrogels showed non-toxicity effect. The cytostimulation property of Arct'Alg was verified by the cytostimulation test with rabbit skin cells, it was showed an increase at about 50% of the cells when in contact with 0,5% of active agent. The hydrogel membranes prepared with 3% of Arct'Alg were subjected to the release test in an incubator at 37 degree C and aliquots collected during the test were quantified by high performance liquid chromatography (HPLC). The results obtained in the kinetics of release showed that the PVP hydrogel membranes released about 50% of Arct'Alg incorporated and the PVA hydrogel membranes at about 30%. In the cytostimulation test of released Arct

  5. Study on Technology of Synthesizing Theaflavins through Enzyme-catalysing Oxidation with Immobilized Laccase%固定化漆酶酶促合成茶黄素工艺的研究

    Institute of Scientific and Technical Information of China (English)

    岳鹍; 揣玉多; 孙勇民

    2011-01-01

    [目的]探索固定化漆酶酶促合成茶黄素的工艺.[方法]采用D152树脂固定化漆酶体外酶促氧化茶多酚合成茶黄素.通过单因素试验研究反应温度、pH、酶浓度、反应时间和通氧量对合成茶黄素的影响,在此基础上进行茶黄素的酶促氧化合成反应,之后测定茶黄素产量.[结果]采用树脂载体D152固定化得到的固定化漆酶,在重复使用5次后,固定化漆酶催化活性约为原始催化活性的70%;在重复使用10次后,酶催化活性仍然可以保留48%左右.固定化漆酶促氧化的最佳条件为:反应温度60 ℃,最佳pH 5,底物浓度2.0g/L,通氧量20 L/min和反应时间1.5h.[结论]采用树脂载体D152可有效固定漆酶.与游离漆酶氧化法相比,固定化法能有效提高漆酶的稳定性和利用效率,反应产物也更易于纯化.%[Objective ] The study aimed to explore the technology of synthesizing the theaflavins through the enzyme-catalysing oxidation with the immobilized laccase. [Method] The theaflavins was synthesized from tea polyphenol through in vitro enzyme-catalysing oxidation with D152 resin immobilized laccase. The effects of the reaction temperature, pH value, enzyme concn. , reaction time and speed of adding oxygen on synthesizing the theaflavins was studied though the single factor experiment, on base of which, the synthesizing reaction through the enzyme-catalysing oxidation was conducted on the theaflavins and then the yield of the theaflavins was determined. [Result] The immobilized laccase was got by the immobilization with the resin carrier D152,the enzyme-catalysing activity by the immobilized laccase was about 70% of the original catalytic activity after the repetition use of the resin for 5 times and that still retained 48% or so after the repetition use for 10 times. The best conditions for the enzyme-catalysing oxidation with the immobilized laccase were as followsjthe reaction temperature of 60 ℃ ,best pH value of 5

  6. Study on Application of Immobilized Microorganism in Marine Oil Spill Bioremediation%固定化微生物对海洋溢油的修复研究

    Institute of Scientific and Technical Information of China (English)

    孙会玲; 王杏娣; 陈庆国; 刘梅; 孙静亚; 魏榕飞; 徐庆达

    2015-01-01

    溢油对海洋生态环境和海洋资源都有长期的危害,溢油污染已经成为人们必须面对的重大环境问题。微生物修复技术可以处理物理方法和化学方法无法清除的残余溢油是恢复生态环境的最佳途径。固定化技术与微生物结合,能够保持微生物高密度、高活性,增强其环境耐受性,提高其降解石油烃的效率,得到了研究者的重视。本文介绍了固定化材料和方法,降解石油烃的微生物的种群,综述了固定化细菌、真菌、微藻在海水、滩涂溢油修复中的研究进展,菌藻组合的优势及在石油烃降解修复中的应用,并对其发展方向进行了展望。%Marine oil spill can hazard marine ecological environment and resource for a long times, and it becomes a serious environmental problem. Microorganism remediation is the best way to deal with the residual oil which is failed to be cleaned up by the physical and chemical methods. Combining immobilized technology and microorganism attracted many researchers’eyes, for its advantage of high density and high activity of mi-croorganism, and more tolerance to environment, which could improve the efficiency of petroleum hydrocarbons degradation. In this paper, materials and methods of immobilized technology and species of microorganism de-grading petroleum hydrocarbons were introduced, the progress of the utilization of immobilized bacteria, fungus and micro-algae in remediation of seawater and shore oil spill was reviewed and the advantages of immobilized algae-bacteria and its application in remediation of marine oil spill were summarized. Finally, an outlook on the development of microorganism immobilized in remediation of marine oil spill was introduced.

  7. 泥藻的固定化方法研究及应用%Study and application of slime algae's immobilized technology

    Institute of Scientific and Technical Information of China (English)

    程东祥; 李红艳

    2011-01-01

    Of 7 kinds of common embedment immobilized technologies, the best embedment immobilized technology,using polyvinyl alcohol (PVA)-sodium alga acid-boric acid, was screened out.With the optimal technology, the best prescription of biosorbent preparation was 10% of the PVA solution, 1% of the sodium alga acid solution, 20% of the remnant active silt (fresh water algae), 1.0% of the CaCl2 solution, 50.0 mol/L LOP of emulsification saturated H3BO3 solution, and 10% of the Na2CO3 solution adjusted to a pH value to 6.7.The diameter of the spherical particle was 3 mm, the immobilization time was more than 4 hours, and the particle was cleaned with distilled water afterwards.The blank immobilized small ball, immobilized WAS, and fresh water algae adsorbent was applied to adsorb Pb2 + and Hg2+in a preliminary experiment.The results were significant.%利用7种常见包埋固定化方法,筛选出以聚乙烯醇-海藻酸钠-硼酸包埋法作为最佳固定化包埋方法;对该方法进行优化,制备生物吸附剂的最佳配方:10%的PVA溶液;1%的海藻酸钠溶液;剩余活性污泥(淡水藻类)20%;1.0%的CaCl2溶液;50.0mol/L的OP乳化液的饱和溶液H3BO3溶液;10%的Na2CO2溶液调节pH至6.7;3min左右的球形颗粒;固定化4h以上,蒸馏水洗净.初步应用固定化空白小球和固定化WAS和固定化淡水藻吸附剂进行吸附pb2+、Hg2+试验,效果较为显著.

  8. IMMOBILIZATION OF LYSOZYME IN POLYVINYL ALCOHOL CRYOGEL

    Directory of Open Access Journals (Sweden)

    S. S. Dekina

    2014-06-01

    Full Text Available The lysozyme immobilization in cryogel of polyvinyl alcohol and physico-chemical properties of obtained preparation was investigated. Hydrolytic activity of lysozyme was determined by bacteriolytic method, using Micrococcus lysodeikticus cells acetone powder as substrate. Protein content was determined by the Lowry–Hartree method. Immobilization of lysozyme was conducted by entrapment in polyvinyl alcohol gel with subsequent cycles of freezing-thawing. Antimicrobial activity was studied by standard disk-diffusional method. The hydrogel filmic coatings with antimicrobial action, insoluble at physiological conditions, with quantitative retaining of protein and hydrolytic activity of lysozyme were obtained. The product is characterized by the widened pH-profile of activity at acidic pH values, stability in acidic medium (pH 5.5 and at storage. Its antimicrobial action against Staphylococcus aureus ATCC 25923 F-49, Pseudomonas aeruginosa 415, Escherichia coli 055 K 59912/4 and Candida albicans ATCC 885-653 was noted. The proposed method of lysozyme immobilization allows to obtain stable, highly effective product with antimicrobial activity, prospective for usage in biomedical investigations.

  9. Comparison study on photocatalytic oxidation of pharmaceuticals by TiO{sub 2}-Fe and TiO{sub 2}-reduced graphene oxide nanocomposites immobilized on optical fibers

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Lu; Wang, Huiyao, E-mail: huiyao@nmsu.edu; Jiang, Wenbin; Mkaouar, Ahmed Radhi; Xu, Pei, E-mail: pxu@nmsu.edu

    2017-07-05

    Highlights: • Incorporating rGO or Fe{sup 3+} ions in TiO{sub 2} photocatalyst could enhance photocatalysis. • TiO{sub 2}-rGO exhibited higher photocatalytic activity under UV irradiation. • TiO{sub 2}-Fe demonstrated more suitable for visible light irradiation. • Reduced recombination rate contributed to enhanced photocatalysis of TiO{sub 2}-rGO. • Narrower band gap accounted for increased photocatalytic activity of TiO{sub 2}-Fe. - Abstract: Incorporating reduced graphene oxide (rGO) or Fe{sup 3+} ions in TiO{sub 2} photocatalyst could enhance photocatalytic degradation of organic contaminants in aqueous solutions. This study characterized the photocatalytic activities of TiO{sub 2}-Fe and TiO{sub 2}-rGO nanocomposites immobilized on optical fibers synthesized by polymer assisted hydrothermal deposition method. The photocatalysts presented a mixture phase of anatase and rutile in the TiO{sub 2}-rGO and TiO{sub 2}-Fe nanocomposites. Doping Fe into TiO{sub 2} particles (2.40 eV) could reduce more band gap energy than incorporating rGO (2.85 eV), thereby enhancing utilization efficiency of visible light. Incorporating Fe and rGO in TiO{sub 2} decreased significantly the intensity of TiO{sub 2} photoluminescence signals and enhanced the separation rate of photo-induced charge carriers. Photocatalytic performance of the synthesized nanocomposites was measured by the degradation of three pharmaceuticals under UV and visible light irradiation, including carbamazepine, ibuprofen, and sulfamethoxazole. TiO{sub 2}-rGO exhibited higher photocatalytic activity for the degradation of pharmaceuticals under UV irradiation, while TiO{sub 2}-Fe demonstrated more suitable for visible light oxidation. The results suggested that the enhanced photocatalytic performance of TiO{sub 2}-rGO could be attributed to reduced recombination rate of photoexcited electrons-hole pairs, but for TiO{sub 2}-Fe nanocomposite, narrower band gap would contribute to increased photocatalytic

  10. Immobilization of Penicillin G Acylase on Calcined Layered Double Hydroxides

    Institute of Scientific and Technical Information of China (English)

    REN Ling-ling; HE Jing; Evans D. G.; DUAN Xue

    2003-01-01

    A hydrotalcite-like Mg2+/Al3+ layered double hydroxide(LDH) material was prepared by means of a modified coprecipitation method involving a rapid mixing step followed by a separate aging process. LDH calcined at 500 ℃, denoted as CLDH, was characterized by XRD, IR and BET surface area measurements. CLDH has a poor crystalline MgO-like structure with a high surface area and porosity. CLDH was used as a support for the immobilization of penicillin G acylase(PGA). The effect of varying the immobilization conditions, such as pH, contact time and the ratio of enzyme to support, on the activity of the immobilized enzyme in the hydrolysis of penicillin G has been studied. It was found that the activity of the immobilized enzyme decreased slightly with decreasing pH and reached a maximum after a contact time of 24 h. The activity of the immobilized enzyme increased with increasing the ratio of enzyme to support. It was found that the adsorption of PGA inhibited the expected reaction of CLDH with an aqueous medium to regenerate a LDH phase. Its original activity(36%) after 15 cycles of reuse of the immobilized enzyme was retained, but no further loss in the activity was observed.

  11. Antibody immobilization on a nanoporous aluminum surface for immunosensor development

    Science.gov (United States)

    Chai, Changhoon; Lee, Jooyoung; Park, Jiyong; Takhistov, Paul

    2012-12-01

    A method of antibody (Ab) immobilization on a nanoporous aluminum surface for an electrochemical immunosensor is presented. To achieve good attachment and stability of Ab on an aluminum surface, aluminum was silanized with 3-aminopropyltryethoxysilane (APTES), and then covalently cross-linked to self-assembled layers (SALs) of APTES. Both the APTES concentration and the silanization time affected the formation of APTES-SALs as Ab immobilization. The formation of APTES-SALs was confirmed using the water contact angle on the APTES-SALs surface. The reactivity of APTES-SALs with Ab was investigated by measuring the fluorescence intensity of fluorescein isothiocyanate-labeled Ab-immobilized on the aluminum surface. Silanization of aluminum in 2% APTES for 4 h resulted in higher water contact angles and greater amounts of immobilized Ab than other APTES concentrations or silanization times. More Ab was immobilized on the nanoporous surface than on a planar aluminum surface. Electrochemical immunosensors developed on the nanoporous aluminum via the Ab immobilization method established in this study responded functionally to the antigen concentration in the diagnostic solution.

  12. Investigation of Enzyme Immobilization Effects on its Characteristics

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Mehrasbi

    2016-09-01

    Full Text Available Background: Enzymes are well known as sensitive catalysts in the laboratory and industrial scale. To improve their properties and for using their significant potential in various reactions as a useful catalyst the stability of enzymes can often require improvement. Enzymes Immobilization on solid supports such as epoxy- functionalized ferric silica nanocomposite can be effective way to improve their characteristics. Methods: In this study silica coated magnetite nanoparticles were Functionalized with GPTSM as a linker, then immobilization reaction performed by using various amounts of lipase B from Candida Antarctica (CALB, for the next step immobilization effects on thermal stability and optimum pH were investigated in comparison with free CALB. Results: Results illustrated enzyme was successfully immobilized on nano particles and immobilized derivative retains 100% of its activity by 55°C while free CALB loss its activity at the same condition. Conclusion: Immobilization of CALB on Fe3O4@SiO2 particles resulted in significant improvements in its characteristics such as thermal stability and methanol tolerance compared to the free CALB.

  13. Immobile Complex Verbs in Germanic

    DEFF Research Database (Denmark)

    Vikner, Sten

    2005-01-01

    Certain complex verbs in Dutch, German, and Swiss German do not undergo verb movement. The suggestion to be made in this article is that these ‘‘immobile'' verbs have to fulfill both the requirements imposed on complex verbs of the V° type (=verbs with non-separable prefixes) and the requirements...... are immobile, - why such verbs are not found in Germanic VO-languages such as English and Scandinavian.......Certain complex verbs in Dutch, German, and Swiss German do not undergo verb movement. The suggestion to be made in this article is that these ‘‘immobile'' verbs have to fulfill both the requirements imposed on complex verbs of the V° type (=verbs with non-separable prefixes) and the requirements...

  14. Tissue stiffness induced by prolonged immobilization of the rat knee joint and relevance of AGEs (pentosidine).

    Science.gov (United States)

    Lee, Sachiko; Sakurai, Takashi; Ohsako, Masafumi; Saura, Ryuichi; Hatta, Hideo; Atomi, Yoriko

    2010-12-01

    Joints, connective tissues consisting of extracellular matrix (ECM) with few blood vessels, transfer tension to the skeleton in response to environmental demand. Therefore, joint immobilization decreases active and passive mechanical stress, resulting in increased joint stiffness and tissue degeneration; however, the cause of joint stiffness is obscure. Using a rat knee immobilization model, we examined the relationship between range of motion (ROM) and cell numbers and ECM cross-links by accumulation of advanced glycation end products, pentosidine, in the posterior joint capsule of immobilized joints during 16 weeks of immobilization. The left knee joint was immobilized by internal fixation and compared with the non-immobilized right leg. As early as 2 weeks of immobilization, joint ROM and torque significantly decreased and in parallel, disordered alignment of collagen fiber bundles significantly increased, compared with non-immobilized joints. Those changes continued until 16 weeks of immobilization. Significant increases in pentosidine-positive areas after 8 weeks and significantly decreased cell numbers after 16 weeks of immobilization were also observed compared to the contralateral side. A significant negative correlation between tissue stiffness measured by restriction of ROM and accumulation of pentosidine was observed. This study is the first to show that immobilization of knee joints induces articular contracture associated with sequential changes of ECM alignment, influencing ROM and later pentosidine accumulation and decreased cell numbers during the 16-week immobilization period. Pentosidine appears to be an indicator toward a chronic tissue stiffness leading to decreased cell number rather than a cause of ROM restriction induced by joint immobilization.

  15. Hydrolysis of triacetin catalyzed by immobilized lipases: effect of the immobilization protocol and experimental conditions on diacetin yield.

    Science.gov (United States)

    Hernandez, Karel; Garcia-Verdugo, Eduardo; Porcar, Raul; Fernandez-Lafuente, Roberto

    2011-05-06

    The effect of the immobilization protocol and some experimental conditions (pH value and presence of acetonitrile) on the regioselective hydrolysis of triacetin to diacetin catalyzed by lipases has been studied. Lipase B from Candida antarctica (CALB) and lipase from Rhizomucor miehei (RML) were immobilized on Sepabeads (commercial available macroporous acrylic supports) activated with glutaraldehyde (covalent immobilization) or octadecyl groups (adsorption via interfacial activation). All the biocatalysts accumulated diacetin. Covalently immobilized RML was more active towards rac-methyl mandelate than the adsorbed RML. However, this covalent RML preparation presented the lowest activity towards triacetin. For this reason, this preparation was discarded as biocatalyst for this reaction. At pH 7, acyl migration occurred giving a mixture of 1,2 and 1,3 diacetin, but at pH 5.5, only 1,2 diacetin was produced. Yields were improved at acidic pH values and in the presence of 20% acetonitrile (to over 95%). RML immobilized on octadecyl Sepabeads was proposed as optimal preparation, mainly due to its higher specific activity. Each enzyme preparation presented very different properties. Moreover, changes in the reaction conditions affected the various immobilized enzymes in a different way.

  16. Biodiesel production from Jatropha oil catalyzed by immobilized Burkholderia cepacia lipase on modified attapulgite.

    Science.gov (United States)

    You, Qinghong; Yin, Xiulian; Zhao, Yuping; Zhang, Yan

    2013-11-01

    Lipase from Burkholderia cepacia was immobilized on modified attapulgite by cross-linking reaction for biodiesel production with jatropha oil as feedstock. Effects of various factors on biodiesel production were studied by single-factor experiment. Results indicated that the best conditions for biodiesel preparation were: 10 g jatropha oil, 2.4 g methanol (molar ratio of oil to methanol is 1:6.6) being added at 3h intervals, 7 wt% water, 10 wt% immobilized lipase, temperature 35°C, and time 24h. Under these conditions, the maximum biodiesel yield reached 94%. The immobilized lipase retained 95% of its relative activity during the ten repeated batch reactions. The half-life time of the immobilized lipase is 731 h. Kinetics was studied and the Vmax of the immobilized lipases were 6.823 mmol L(-1). This immobilized lipase catalyzed process has potential industrial use for biodiesel production to replace chemical-catalyzed method.

  17. Study on transformation of stevioside by immobilized β-glucosidase%固定化β-葡萄糖苷酶转化甜菊糖的研究

    Institute of Scientific and Technical Information of China (English)

    刘虎; 陈育如; 姜中玉

    2011-01-01

    Stevioside was hydrolyzed steviolbioside using immobilized β- glucosidase produced by Bacillus megaterium.The conditions of immobilized enzymes degrading stevioside were investigated.The embedding material was sodium alginate.The optimum method was determined by the single factor analysis.The results of conversion showed that 10mg/mL stevioside can be converted to steviolbioside by 96.45% for 5d under the condition of 40℃, pH7.0,20g/100mL immobilized β- glucosidase.The activity of immobilized enzyme recovered after 4 times was 57.77% of the original enzyme, which showed high stability and recyclability.The process was simple,low cost in the transformation of stevioside and had a potential application prospects for improvement of the purity of rebaudioside A.%用海藻酸钠作为包埋材料,对巨大芽孢杆菌所产β-葡萄糖苷酶进行了固定化,并对固定化酶转化甜菊糖的条件进行了研究.采用单因素分析方法探讨了温度、pH、时间、酶量、底物浓度和回收次数对转化的影响.结果表明,固定化酶在40℃、pH7.0,酶量20g/100mL时转化5d,可将1%it菊糖(W/W)中的甜菊苷转化96.45%,固定化酶经4次重复利用后其转化活力仍能维持在原活性的57.77%,具有较好的稳定性和可回收性.该工艺操作简单、成本较低,在转化甜菊苷、提高莱鲍迪甙A纯度方面具有潜在的应用前景.

  18. Immobilization of a Pleurotus ostreatus Laccase Mixture on Perlite and Its Application to Dye Decolourisation

    OpenAIRE

    Cinzia Pezzella; Maria Elena Russo; Antonio Marzocchella; Piero Salatino; Giovanni Sannia

    2014-01-01

    In the present study, a crude laccase preparation from Pleurotus ostreatus was successfully immobilized on perlite, a cheap porous silica material, and tested for Remazol Brilliant Blue R (RBBR) decolourisation in a fluidized bed recycle reactor. Results showed that RBBR decolourisation is mainly due to enzyme action despite the occurrence of dye adsorption-related enzyme inhibition. Fine tuning of immobilization conditions allowed balancing the immobilization yield and the resulting rate of ...

  19. Immobilization and catalytic properties of lipase on chitosan for hydrolysis and esterification reactions

    OpenAIRE

    2003-01-01

    The objective of this study was to evaluate the immobilization of lipase on a chitosan support by physical adsorption, aiming at its application in hydrolytic and synthetic reactions. Two types of chitosan (flakes and porous) were used for immobilizing lipase from a microbial source (Candida rugosa) and animal cells (porcine pancreas). The best results for recovery of total activity after immobilization were obtained for microbial lipase and porous chitosan beads. This set was selected for fu...

  20. Preparation, characterization, and luminescence of (SBA-15) immobilized pepsin

    Science.gov (United States)

    Zhai, Qing-Zhou; Sun, Si-Jia

    2014-12-01

    SBA-15 mesoporous silica was synthesized by hydrothermal method and its surface was methylated by treatment with methyltrimethoxysilane. Pepsin was immobilized on the obtained materials giving host-guest composite materials (SBA-15)-pepsin and (methylated SBA-15)-pepsin. The optimum conditions for preparation of these materials were established. Methylated SBA-15 (M-SBA-15) has improved immobilization efficiency of enzyme compared to initial SBA-15 silica. It was shown that with the gradual increase of NaCl solution ionic strength the immobilized amount of enzyme was reduced. Powder X-ray diffraction and Fourier transform infrared spectroscopy showed that the host frameworks in the prepared host-guest composite materials are intact and the ordered structure was retained. Scanning electron microscopic studies revealed fibrous morphologic characteristics of the SBA-15 and the immobilized pepsin composite materials. The average particle diameter of (SBA-15)-pepsin composite was 338 ± 10 and 343 ± 10 nm for (M-SBA-15)-pepsin. The low temperature N2 adsorption-desorption study at 77 K showed that the pore sizes and specific surface areas of the host-guest composite materials were smaller than those before the introduction of the enzyme, suggesting that the immobilized enzyme occupied a definite position in the host material pore channels. The UV-vis solid diffuse reflectance and luminescence studies showed that the enzyme was successfully immobilized on to the host material and that after the immobilization of enzyme on SBA-15 the conformation of pepsin macromolecule has not been changed.

  1. Immobile Complex Verbs in Germanic

    DEFF Research Database (Denmark)

    Vikner, Sten

    2005-01-01

    (and why this single prefix-like part may NOT be a particle), - why immobile verbs even include verbs with two prefix-like parts, where each of these are separable particles (as in, e.g., German voranmelden ‘preregister'), - why there is such a great amount of speaker variation as to which verbs...

  2. Immobilization of cellulases on magnetic particles to enable enzyme recycling during hydrolysis of lignocellulose

    DEFF Research Database (Denmark)

    Alftrén, Johan

    on commercial magnetic particles coated with streptavidin. The procedure enabled simultaneous purification and immobilization from crude cell lysate because of the very strong interaction and high affinity between biotin and streptavidin. A third method of immobilizing enzymes was employed in paper IV where two...... feedstocks containing insolubles. This could potentially be overcome by immobilizing the cellulases on magnetically susceptible particles. Consequently, the immobilized cellulases could be magnetically recovered and recycled for a new cycle of enzymatic hydrolysis of cellulose. The main objective...... of this thesis was to examine the possibility of immobilizing cellulases on magnetic particles in order to enable enzyme re-use. Studies at lab and pilot scale (20 L) were conducted using model and real substrates. In paper I and III beta-glucosidase or a whole cellulase mixture was covalently immobilized...

  3. Enzyme immobilization and biocatalysis of polysiloxanes

    Science.gov (United States)

    Poojari, Yadagiri

    Lipases have been proven to be versatile and efficient biocatalysts which can be used in a broad variety of esterification, transesterification, and ester hydrolysis reactions. Due to the high chemo-, regio-, and stereo-selectivity and the mild conditions of lipase-catalyzed reactions, the vast potential of these biocatalysts for use in industrial applications has been increasingly recognized. Polysiloxanes (silicones) are well known for their unique physico-chemical properties and can be prepared in the form of fluids, elastomers, gels and resins for a wide variety of applications. However, the enzymatic synthesis of silicone polyesters and copolymers is largely unexplored. In the present investigations, an immobilized Candida antarctica lipase B (CALB) on macroporous acrylic resin beads (Novozym-435 RTM) has been successfully employed as a catalyst to synthesize silicone polyesters and copolymers under mild reaction conditions. The silicone aliphatic polyesters and the poly(dimethylsiloxane)--poly(ethylene glycol) (PDMS-PEG) copolymers were synthesized in the bulk (without using a solvent), while the silicone aromatic polyesters, the silicone aromatic polyamides and the poly(epsilon-caprolactone)--poly(dimethylsiloxane)--poly(epsilon-caprolactone) (PCL-PDMS-PCL) triblock copolymers were synthesized in toluene. The synthesized silicone polyesters and copolymers were characterized by Gel Permeation Chromatography (GPC), Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC) and Wide Angle X-ray Diffraction (WAXD). This dissertation also describes a methodology for physical immobilization of the enzyme pepsin from Porcine stomach mucosa in silicone elastomers utilizing condensation-cure room temperature vulcanization (RTV) of silanol-terminated poly(dimethylsiloxane) (PDMS). The activity and the stability of free pepsin and pepsin immobilized in silicone elastomers were studied with respect to p

  4. Immobilization of the laccases from trametes versicolor and streptomyces coelicolor on single-wall carbon nanotube electrodes: a molecular dynamics study

    Energy Technology Data Exchange (ETDEWEB)

    Trohalaki, S. [Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson Air Force Base, OH (United States); General Dynamics Information Technology, Dayton, OH (United States); Pachter, R. [Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson Air Force Base, OH (United States); Luckarift, H.R. [Materials and Manufacturing Directorate, Air Force Research Laboratory, Tyndall Air Force Base, FL (United States); Universal Technology Corporation, Dayton, OH (United States); Johnson, G.R. [Materials and Manufacturing Directorate, Air Force Research Laboratory, Tyndall Air Force Base, FL (United States)

    2012-08-15

    In this work, we investigate the immobilization of laccases from Trametes versicolor (TvL) and the small laccase (SLAC) from Streptomyces coelicolor on single-wall carbon nanotube (SWCNT) surfaces. SLAC may potentially offer improved adsorption on the electrode, thus improving bioelectrocatalytic activity via direct electron transfer (DET). Laccase immobilization on SWCNTs is achieved non-covalently with a molecular tether (1-pyrene butanoic acid, succinimidyl ester) that forms an amide bond with an amine group on the laccase surface while the pyrene coordinates to the SWCNT by {pi}-{pi} stacking. In our approach, density functional theory calculations were first used to model the interaction energies between SWCNTs and pyrene to validate an empirical force field, thereafter applied in molecular dynamics (MD) simulations. In the simulated models, the SWCNT was placed near the region of the (type 1) Cu(T1) atom in the laccases, and in proximity to other regions where adsorption seems likely. Calculated interaction energies between the SWCNTs and laccases and distances between the SWCNT surface and the Cu(T1) atom have shown that SWCNTs adsorb more strongly to SLAC than to TvL, and that the separation between the SWCNTs and Cu(T1) atoms is smaller for SLAC than for TvL, having implications for improved DET. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  5. 铜绿假单胞菌 S8脂肪酶酶学性质及固定化研究%Study on Immobilization and Enzymatic Properties of Lipase from Pseudomonas aeruginosa S8

    Institute of Scientific and Technical Information of China (English)

    曲威; 刘惠军; 薛元霞

    2015-01-01

    以耐甲醇铜绿假单胞菌( Pseudomonas aeruginosa) S8为出发菌株,通过摇瓶发酵产脂肪酶,对发酵脂肪酶粗酶液进行酶学性质及固定化研究。结果表明:该脂肪酶反应的最适温度为35℃,最适pH值为7.0,在pH 6.0~8.0酶活较稳定。以硅藻土为载体,采用吸附法,对脂肪酶进行固定,脂肪酶的最佳固定化条件为:载体硅藻土与脂肪酶质量比为10,固定化温度为30℃,缓冲液pH值为7.5,固定化时间为2.5 h。%The lipase produced by Pseudomonas aeruginosa S8 through flask fermentation was studied in enzymatic properties and immobilization .The results showed that the optimal reaction temperature and opti-mum pH value were 35℃and 7.0 respectively.The enzyme activity was stable at pH 6.0~8.0.The lipase was immoblilized on the carrier diatomite with absorption activity .The optimal immobilizing conditions were the mass ratio of carrier to enzymae as 10, immobilizing for 2.5 hours at 30℃and pH value as 7.5.

  6. DNA-directed immobilization of horseradish peroxidase onto porous SiO2 optical transducers

    Science.gov (United States)

    Shtenberg, Giorgi; Massad-Ivanir, Naama; Engin, Sinem; Sharon, Michal; Fruk, Ljiljana; Segal, Ester

    2012-08-01

    Multifunctional porous Si nanostructure is designed to optically monitor enzymatic activity of horseradish peroxidase. First, an oxidized PSi optical nanostructure, a Fabry-Pérot thin film, is synthesized and is used as the optical transducer element. Immobilization of the enzyme onto the nanostructure is performed through DNA-directed immobilization. Preliminary studies demonstrate high enzymatic activity levels of the immobilized horseradish peroxidase, while maintaining its specificity. The catalytic activity of the enzymes immobilized within the porous nanostructure is monitored in real time by reflective interferometric Fourier transform spectroscopy. We show that we can easily regenerate the surface for consecutive biosensing analysis by mild dehybridization conditions.

  7. The effect of wrist immobilization on performance of the Jebsen Hand Function Test.

    Science.gov (United States)

    Carlson, J D; Trombly, C A

    1983-03-01

    Eighteen normal subjects participated in a study designed to monitor the effect of wrist motion on the time required to complete manual tasks from the Jebsen Hand Function Test. Activities were performed with the wrist free and with the wrist immobilized by a commercially available splint. The results showed a statistically significant increase in time to do the tasks during immobilization when compared to the free condition. There was great variation in patterns of motion between individuals. Treatment implications include individual consideration of position of wrist immobilization for splinting, proper length and fit of splint designed to immobilize, and the importance of practice in tasks following loss of wrist motion.

  8. Effect of linoleic-acid modified carboxymethyl chitosan on bromelain immobilization onto self-assembled nanoparticles

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Hydrogel nanoparticles could be prepared by using linoleic acid (LA) modified carboxymethyl chitosan (CMCS) after sonication.Bromelain could be loaded onto nanoparticles of LA-CMCS.Factors affecting the activity of the immobilized enzyme,including temperature,storage etc.,were investigated in this study.The results showed that the stability of bromelain for heat and storage was improved after immobilization on nanoparticles.The Michaelis constant (Km) of the immobilized enzyme was smaller than that of free enzyme,indicating that the immobilization could promote the stability of the enzyme and strengthen the affinity of the enzyme for the substrate.

  9. Growth and by-product profiles of Kluyveromyces marxianus cells immobilized in foamed alginate.

    Science.gov (United States)

    Wilkowska, Agnieszka; Kregiel, Dorota; Guneser, Onur; Karagul Yuceer, Yonca

    2015-01-01

    The aim of this research was to study how the yeast cell immobilization technique influences the growth and fermentation profiles of Kluyveromyces marxianus cultivated on apple/chokeberry and apple/cranberry pomaces. Encapsulation of the cells was performed by droplet formation from a foamed alginate solution. The growth and metabolic profiles were evaluated for both free and immobilized cells. Culture media with fruit waste produced good growth of free as well as immobilized yeast cells. The fermentation profiles of K. marxianus were different with each waste material. The most varied aroma profiles were noted for immobilized yeast cultivated on apple/chokeberry pomace.

  10. MUCOADHESIVE GEL WITH IMMOBILIZED LYSOZYME: PREPARATION AND PROPERTIES

    Directory of Open Access Journals (Sweden)

    Dekina S. S.

    2015-08-01

    Full Text Available The study of non-covalent immobilized lysozyme, as well as physico-chemical and biochemical properties of obtained mucoadhesive gel was the aim of the research. Lysozyme activity was determined by bacteriolytic method (Micrococcus lysodeikticus cells acetone powder was a substrate. Lysozyme immobilization was conducted by the method of entrapment in gel. Enzyme carrier interaction was studied by viscometric, spectrophotometric and spectrofluorimetric methods. Mucoadhesive gel with immobilized lysozyme, possessing antiinflammatory and antimicrobial activities, was prepared. Due to immobilization, protein-polymer complex with the original enzymatic activity was formed. The product is characterized by high mucoadhesive properties, quantitative retaining of protein and bacteriolytic activity, prolonged release of the enzyme, improved biochemical characteristics (extended pH-activity profile, stability in acidic medium and during storage for 2 years, and it is perspective for further studies. The proposed method for lysozyme immobilization in the carboxymethyl cellulose sodium salt gel allows to obtain a stable, highly efficient product, with high adhesive properties for attachment to the mucous membranes, that is promising for use in biomedicine.

  11. PREPARATION AND CHARACTERIZATION OF BIOCATALYSTS BASED ON IMMOBILIZED GLYCOSIDASES

    Directory of Open Access Journals (Sweden)

    O. L. Meshcheriakova

    2014-01-01

    Full Text Available Summary. Enzymes subclass glycosidases cleaving poly- and oligosaccharides to simple sugars, are of great practical importance for a variety of industries. Such enzymes include α-L-fucosidase and β-fructofuranosidase. α-L-fucosidase splits fucoidan kelp to fucose and fucooligosaccharides. Fucose has prebiotic, immunotropic action, and a wide spectrum of biological activity in vertebrates, fucooligosaccharides - antioxidant and prebiotic properties. In this regard, and fucose polymers may be demanded in the food, feed and pharmaceutical industry. β-fructofuranosidase sucrose hydrolysis with the formation of invert syrup high quality and biological value that is of interest to the sugar industry. In order to intensify the processes of hydrolysis of fucoidan and sucrose due to the higher stability and reusability of enzyme preparations carried immobilization α-L-fucosidase on chitosan and β-fructofuranosidase of ion exchange brand FIBAN A-6 adsorption method. Activity of the immobilized α-L-fucosidase and β-fructofuranosidase were 80 and 70% of the activity of the free enzyme, respectively. Found that immobilized β-fructofuranosidase exhibits maximal activity at pH 4,0-4,1, the immobilized α-L-fucosidase - at pH 7,0. The optimal pH of immobilized enzymes similar to those for the free enzyme. Optimal temperature hydrolysis substrates immobilized α-L-fucosidase and β-fructofuranosidase was 50 and 70 ° C respectively, 10 ° C and 20 ° C higher compared to free enzymes. Studies have shown sufficient stability of immobilized glycosidases, so at 4-fold using their enzymatic activity decreased by 1.5 times; Biocatalysts obtained in storage in the refrigerator for 4-6 months retained 80% of the catalytic activity of enzymes.

  12. Biodiesel production with immobilized lipase: A review.

    Science.gov (United States)

    Tan, Tianwei; Lu, Jike; Nie, Kaili; Deng, Li; Wang, Fang

    2010-01-01

    Fatty acid alkyl esters, also called biodiesel, are environmentally friendly and show great potential as an alternative liquid fuel. Biodiesel is produced by transesterification of oils or fats with chemical catalysts or lipase. Immobilized lipase as the biocatalyst draws high attention because that process is "greener". This article reviews the current status of biodiesel production with immobilized lipase, including various lipases, immobilization methods, various feedstocks, lipase inactivation caused by short chain alcohols and large scale industrialization. Adsorption is still the most widely employed method for lipase immobilization. There are two kinds of lipase used most frequently especially for large scale industrialization. One is Candida antartica lipase immobilized on acrylic resin, and the other is Candida sp. 99-125 lipase immobilized on inexpensive textile membranes. However, to further reduce the cost of biodiesel production, new immobilization techniques with higher activity and stability still need to be explored.

  13. Editorial: Special Issue — Enzyme Immobilization

    Directory of Open Access Journals (Sweden)

    Roberto Fernandez-Lafuente

    2014-12-01

    Full Text Available Immobilization of enzymes and proteins is a requirement for many industrial enzyme applications, as this facilitates enzyme recovery and reuse. Bearing in mind this necessity, the coupling of immobilization to the improvement of other enzyme features has been pursued by many researchers, and nowadays immobilization is recognized as a tool to improve not only stability, but also enzyme selectivity, specificity, resistance to inhibition or chemical modifiers, etc. To achieve these overall improvements of enzymes’ properties via immobilization, it is necessary to both develop new immobilization systems suitable for these purposes, and to achieve a deeper knowledge of the mechanisms of interaction between enzymes and activated solids. That way, immobilization of enzymes, far being an old-fashioned methodology to just reuse these expensive biocatalysts, is a tool of continuous interest that requires a continuous effort to be exploited in all its potential. This special issue collects 23 papers reporting advances in the field of immobilization of enzymes.[...

  14. INFLUENCE OF SHORTENED AND LENGTHENED IMMOBILIZATION ON RAT SOLEUS MUSCLE ATROPHY

    Institute of Scientific and Technical Information of China (English)

    邢国刚; 樊小力; 吴苏娣; 宋新爱; 朱保恭; 唐斌

    2001-01-01

    Objective: To study the possible mechanism and prevention of disuse muscle atrophy. Methods: The shortened immobilization (plaster fixation) of rat' s soleus muscle (SOL) was used as the model of muscle and the lengthened immobilization of rat' s SOL muscle as "passive stretch" method. Types of skeletal muscle fibers were differentiated with m - ATPase staining technique. The changes of rat' s SOL muscle weight (wet weight) as well as the types and the mean cross - sectional area (CSA) of muscle fibers were examined respectively on day 2, 4,7, 14 and 21 under both shortened and lengthened immobilization and then the effect of passive stretch on soleus muscle atrophy in immobilized rats was observed. Results: When shortened immobilization was applied for 4 days, SOL muscle weight (wet weight) became lighter; the fiber crosssectional area (CSA) shrank and type Ⅰ muscle fibers started transforming into type Ⅱ, which all indicated immobilized muscles began to atrophy and as immobilization proceeded, muscle atrophy proceeded toward higher level. In contrast to that, when lengthened immobilization was applied, SOL muscle didn' t show any sign of atrophy until 7th day, and reached its highest level on day 14 and maintained that level even though immobilization continued. Conclusion: From the results, we conclude that passive stretch can either relieve or defer disuse muscle atrophy.

  15. EFFECTS OF PASSIVE STRETCH ON SOLEUS MUSCLE ATROPHY IN IMMOBILIZED RATS

    Institute of Scientific and Technical Information of China (English)

    邢国刚; 樊小力; 吴苏娣; 宋新爱; 朱保恭; 唐斌

    2002-01-01

    Objective To study the possible mechanism and prevention of disused muscle atrophy. Methods The shortened immobilization (plaster fixation) of rat's soleus muscle(SOL) was used as the model of muscle "disuse" and the lengthened immobilization of rat's SOL muscle as "passive stretch" method. Types of skeletal muscle fibers were differentiated with m-ATPase staining technique. The changes of rat's SOL weight (wet weight) as well as the types and the mean cross sectional area (CSA) of muscle fibers were examined respectively on days 2,4,7,14 and 21 under both shortened and lengthened immobilization, and then the effect of passive stretch on soleus muscle atrophy in immobilized rats was observed. Results When shortened immobilization was applied for 4 days, SOL weight (wet weight ) became lighter, the fiber cross-sectional area (CSA) shrank, and type Ⅰ muscle fibers started to transform into type Ⅱ, which all indicated that immobilized muscles began to atrophy, and as immobilization proceeded, muscle atrophy proceeded toward higher level. In contrast to that, when lengthened immobilization was applied, SOL didn't show any signs of atrophy until day 7, the sign reached its highest level on day 14 and maintained that level even though immobilization continued. Conclusion From the results, we conclude that the passive stretch can either relieve or retard the disused muscle atrophy.

  16. Effect of membranes with various hydrophobic/hydrophilic properties on lipase immobilized activity and stability.

    Science.gov (United States)

    Chen, Guan-Jie; Kuo, Chia-Hung; Chen, Chih-I; Yu, Chung-Cheng; Shieh, Chwen-Jen; Liu, Yung-Chuan

    2012-02-01

    In this study, three membranes: regenerated cellulose (RC), glass fiber (GF) and polyvinylidene fluoride (PVDF), were grafted with 1,4-diaminobutane (DA) and activated with glutaraldehyde (GA) for lipase covalent immobilization. The efficiencies of lipases immobilized on these membranes with different hydrophobic/hydrophilic properties were compared. The lipase immobilized on hydrophobic PVDF-DA-GA membrane exhibited more than an 11-fold increase in activity compared to its immobilization on a hydrophilic RC-DA-GA membrane. The relationship between surface hydrophobicity and immobilized efficiencies was investigated using hydrophobic/hydrophilic GF membranes which were prepared by grafting a different ratio of n-butylamine/1,4-diaminobutane (BA/DA). The immobilized lipase activity on the GF membrane increased with the increased BA/DA ratio. This means that lipase activity was exhibited more on the hydrophobic surface. Moreover, the modified PVDF-DA membrane was grafted with GA, epichlorohydrin (EPI) and cyanuric chloride (CC), respectively. The lipase immobilized on the PVDF-DA-EPI membrane displayed the highest specific activity compared to other membranes. This immobilized lipase exhibited more significant stability on pH, thermal, reuse, and storage than did the free enzyme. The results exhibited that the EPI modified PVDF is a promising support for lipase immobilization.

  17. Immobilization of Cyclooxygenase-2 on Silica Gel Microspheres: Optimization and Characterization

    Directory of Open Access Journals (Sweden)

    Qian Shi

    2015-11-01

    Full Text Available In this study, immobilized COX-2 was successfully constructed through glutaraldehyde-mediated covalent coupling on functional silica gel microspheres. The optimum conditions, properties, and morphological characteristics of the immobilized COX-2 were investigated. The optimal immobilization process was as follows: about 0.02 g of aminated silica gel microspheres was activated by 0.25% GA solution for 6 h and mixed with 5 U of free recombinant COX-2 solution. Then, the mixture was shaken for 8 h at 20 °C. Results showed that the immobilized COX-2 produced by this method exhibited excellent biocatalytic activity, equivalent to that of free COX-2 under the test conditions employed. The best biocatalytic activity of immobilized COX-2 appeared at pH 8.0 and still maintained at about 84% (RSD < 7.39%, n = 3 at pH 10.0. For temperature tolerance, immobilized COX-2 exhibited its maximum biocatalytic activity at 40 °C and about 68% (RSD < 6.99%, n = 3 of the activity was maintained at 60 °C. The immobilized COX-2 retained over 85% (RSD < 7.26%, n = 3 of its initial biocatalytic activity after five cycles, and after 10 days storage, the catalytic activity of immobilized COX-2 still maintained at about 95% (RSD < 3.08%, n = 3. These characteristics ensured the convenient use of the immobilized COX-2 and reduced its production cost.

  18. Metal immobilization and soil amendment efficiency at a contaminated sediment landfill site: a field study focusing on plants, springtails, and bacteria.

    Science.gov (United States)

    Bert, Valérie; Lors, Christine; Ponge, Jean-François; Caron, Lucie; Biaz, Asmaa; Dazy, Marc; Masfaraud, Jean-François

    2012-10-01

    Metal immobilization may contribute to the environmental management strategy of dredged sediment landfill sites contaminated by metals. In a field experiment, amendment effects and efficiency were investigated, focusing on plants, springtails and bacteria colonisation, metal extractability and sediment ecotoxicity. Conversely to hydroxylapatite (HA, 3% DW), the addition of Thomas Basic Slag (TBS, 5% DW) to a 5-yr deposited sediment contaminated with Zn, Cd, Cu, Pb and As resulted in a decrease in the 0.01 M Ca(NO(3))(2)-extractable concentrations of Cd and Zn. Shoot Cd and Zn concentration in Calamagrostis epigejos, the dominant plant species, also decreased in the presence of TBS. The addition of TBS and HA reduced sediment ecotoxicity and improved the growth of the total bacterial population. Hydroxylapatite improved plant species richness and diversity and decreased antioxidant enzymes in C. Epigejos and Urtica dïoica. Collembolan communities did not differ in abundance and diversity between the different treatments.

  19. Evaluation of an organo-layered double hydroxide and two organic residues as amendments to immobilize metalaxyl enantiomers in soils: A comparative study.

    Science.gov (United States)

    López-Cabeza, Rocío; Cornejo, Juan; Celis, Rafael

    2016-10-01

    Many pollutants released into the environment as a result of human activities are chiral. Pollution control strategies generally consider chiral compounds as if they were achiral and rarely consider enantiomers separately. We compared the performance of three different materials, an organically-modified anionic clay (HT-ELA) and two organic agro-food residues (ALP and ALPc), as amendments to immobilize the chiral fungicide metalaxyl in two soils with different textures, addressing the effects of the amendments on the sorption, persistence, and leaching of each of the two enantiomers of metalaxyl (R-metalaxyl and S-metalaxyl) separately. The effects of the amendments were both soil- and amendment-dependent, as well as enantiomer-selective. The organo-clay (HT-ELA) was much more efficient in increasing the sorption capacity of the soils for the two enantiomers of metalaxyl than the agro-food residues (ALP and ALPc), even when applied at a reduced application rate. The enhanced sorption in HT-ELA-amended soils reduced the bioavailability of metalaxyl enantiomers and their leaching in the soils, mitigating the particularly high leaching potential of the more persistent S enantiomer. The immobilizing capacity of the agro-food residues was more variable, mainly because their addition did not greatly ameliorate the sorption capacity of the soils and had variable effects on the enantiomers degradation rates. HT-ELA showed potential to reduce the bioavailability and mobility of metalaxyl enantiomers in soil and to mitigate the contamination problems particularly associated with the higher leaching potential of the more persistent enantiomer.

  20. Study of immobilization of radioactive wastes in asphaltic matrices and elastomeric residues by using microwave technique; Estudo da imobilizacao de rejeitos radioativos em matrizes asfalticas e residuos elastomericos utilizando a tecnica de microondas

    Energy Technology Data Exchange (ETDEWEB)

    Caratin, Reinaldo Leonel

    2007-07-01

    In the present work, the technique of microwave heating was used to study the immobilization of low and intermediate activity level radioactive waste, such as spent ion exchange resin used to remove undesirable ions of primary circuits of refrigeration in water refrigerated nuclear reactors, and those used in chemical and radionuclide separation columns in the quality control of radioisotopes. Bitumen matrices reinforced with some kinds of rubber (Neoprene{sup R}, silicon and ethylene-vinyl-acetate), from production leftovers or scraps, were used for incorporation of radioactive waste. The samples irradiation was made in a home microwave oven that operates at a frequency of 2.450 MHZ with 1.000 W power. The samples were characterized by developing assays on penetration, leaching resistance, softening, flash and combustion points, thermogravimetry and optical microscopy. The obtained results were compatible with the pattern of matrices components, which shows that technique is a very useful alternative to conventional immobilization methods and to those kinds of radioactive waste. (author)

  1. Evaluation of laboratory and industrial meat and bone meal combustion residue as cadmium immobilizing material for remediation of polluted aqueous solutions: 'Chemical and ecotoxicological studies'

    Energy Technology Data Exchange (ETDEWEB)

    Coutand, M., E-mail: marie.coutand@iut-tlse3.fr [Universite de Toulouse (France); UPS, INSA (France); LMDC - Laboratoire Materiaux et Durabilite des Constructions, 135, avenue de Rangueil, F-31 077 Toulouse Cedex 04 (France); Deydier, E., E-mail: eric.deydier@iut-tlse3.fr [Universite de Toulouse, Laboratoire de Chimie de Coordination du CNRS (UPR 8241), lie par convention a l' Universite Paul Sabatier - IUT A, Avenue Georges Pompidou, BP258, 81104 Castres (France); Cyr, M. [Universite de Toulouse (France); UPS, INSA (France); LMDC - Laboratoire Materiaux et Durabilite des Constructions, 135, avenue de Rangueil, F-31 077 Toulouse Cedex 04 (France); and others

    2009-07-30

    Meat and Bone Meals (MBM) combustion residues (ashes) are calcium and phosphate-rich materials. The aim of this work is to evaluate ashes efficiency for remediation of cadmium-contaminated aqueous solutions, and to assess the bioavailability of cadmium on Xenopuslaevis larvae. In this study both industrial (MBM-BA) and laboratory (MBM-LA) ashes are compared regarding their efficiency. Kinetic investigations reveal that cadmium ions are quickly immobilized, with a maximum cadmium uptake at 57 mg Cd{sup 2+}/g of ashes for MBM-LA, two times higher than metal uptake quantity of MBM-BA, in our experimental conditions. Chemical and X-ray diffraction analysis (XRD) reveal that Cd{sup 2+} is mainly immobilized as Ca{sub 10-x}Cd{sub x}(PO{sub 4}){sub 6}(OH){sub 2} by both ashes, whereas otavite, Cd(CO{sub 3}), is also involved for MBM-LA in cadmium uptake. Otavite formation could be explained by the presence of carbonates in MBM-LA, as observed by IR. Genotoxicity of cadmium solution on Xenopus larvae is observed at 0.02, 0.2 and 2 mg Cd{sup 2+}/L. However addition of only 0.1 g/L MBM-LA inhibits these effects for the above concentration values whereas Cd{sup 2+} bioaccumulation in larvae's liver is similar for both experiments, with and without ashes.

  2. Immobilization of Yarrowia lipolytica for aroma production from castor oil.

    Science.gov (United States)

    Braga, Adelaide; Belo, Isabel

    2013-04-01

    The main aim of this study was to compare different materials for Y. lipolytica immobilization that could be used in the production of γ-decalactone (a peach-like aroma) in order to prevent the toxic effect both of the substrate and the aroma upon the cells. Therefore, cells adsorption onto pieces of methyl polymethacrylate and of DupUM(®) was studied and further used in the biotransformation of castor oil into γ-decalactone. The highest aroma concentration was obtained with immobilized cells in DupUM(®), where reconsumption of the aroma by the cells was prevented, contrarily to what happens with free cells. This is a very promising result for γ-decalactone production, with potential to be used at an industrial level since the use of immobilized cells system will facilitate the conversion of a batch process into a continuous mode keeping high cell density and allowing easier recovery of metabolic products.

  3. Immobilization of glucosyltransferase from Erwinia sp. using two different techniques.

    Science.gov (United States)

    Contesini, Fabiano Jares; Ibarguren, Carolina; Grosso, Carlos Raimundo Ferreira; Carvalho, Patrícia de Oliveira; Sato, Hélia Harumi

    2012-04-15

    Two different techniques of glucosyltransferase immobilization were studied for the conversion of sucrose into isomaltulose. The optimum conditions for immobilization of Erwinia sp. glucosyltransferase onto Celite 545, determined using response surface methodology, was pH 4.0 and 170 U of glucosyltransferase/g of Celite 545. Using this conditions more than 60% conversion of sucrose into isomaltulose can be obtained. The immobilization of glucosyltransferase was also studied by its entrapment in microcapsules of low-methoxyl pectin and fat (butter and oleic acid). The non-lyophilized microcapsules of pectin, containing the enzyme and fat, showed higher glucosyltransferase activity, compared with lyophilized microcapsules containing enzyme plus fat, and also lyophilized microcapsules containing enzyme without fat addition. The non-lyophilized microcapsules of pectin containing the glucosyltransferase and fat, converted 30% of sucrose into isomaltulose in the first batch. However the conversion decreased to 5% at the 10th batch, indicating inactivation of the enzyme.

  4. Fast multipoint immobilized MOF bioreactor.

    Science.gov (United States)

    Liu, Wan-Ling; Wu, Cheng-You; Chen, Chien-Yu; Singco, Brenda; Lin, Chia-Her; Huang, Hsi-Ya

    2014-07-14

    An enzyme-NBD@MOF bioreactor with exemplary proteolytic performance, even after successive reuse and storage, was produced through a novel, rapid and simple multipoint immobilization technique without chemical modification of the solid support. Enzyme loading and distribution could be directly monitored from the fluorescence emission of the bioreactor. The dye molecular dimension plays a role in its overall performance. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Properties of an immobilized lipase of Bacillus coagulans BTS-1.

    Science.gov (United States)

    Kanwari, S S; Srivastava, M; Chimni, S S; Ghazi, I A; Kaushal, R K; Joshi, G K

    2004-01-01

    Lipase (EC 3.1.1.3) is a tri-acylglycerol ester hydrolase, catalysing the hydrolysis of tri-, di-, and mono-acylglycerols to glycerol and fatty acids. To study the effect of adsorption of a lipase obtained from Bacillus coagulans BTS-1, its lipase was immobilized on native and activated (alkylated) matrices, i.e. silica and celite. The effect of pH, temperature, detergents, substrates, alcohols, organic solvent etc. on the stability of the immobilized enzyme was evaluated. The gluteraldahyde or formaldehyde (at 1% and 2% concentration, v/v) activated matrix was exposed to the Tris buffered lipase. The enzyme was adsorbed/entrapped more rapidly on to the activated silica than on the activated celite. The immobilized lipase showed optimal activity at 50 degrees C following one-hour incubation. The lipase was specifically more hydrolytic to the medium C-length ester (p-nitro phenyl caprylate than p-nitro phenyl laurate). The immobilization/entrapment enhanced the stability of the lipase at a relatively higher temperature (50 degrees C) and also promoted enzyme activity at an acidic pH (pH 5.5). Moreover, the immobilized lipase was quite resistant to the denaturing effect of SDS.

  6. [Immobilization of heavy metal Pb2+ with geopolymer].

    Science.gov (United States)

    Jin, Man-tong; Jin, Zan-fang; Huang, Cai-ju

    2011-05-01

    A series of geopolymers were synthesized by mixing metakaolinite, water glass, sodium hydroxide and water, and the lead ion solidification experiments were performed with the geopolymer. Then, the immobilization efficiency was characterized by monitoring the leaching concentration and compressive strength of solidified products. Additionally, the structure and properties of the solidified products were studied by X-ray diffraction (XRD), scan electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy. Furthermore, based on the analysis of immobilization efficiency, microstructure and mineral structure, the difference between geopolymer and cement on the performance of immobilizing heavy metals was discussed. The results of lead ion immobilization experiments showed that over 99.7% of heavy metal was captured by the geopolymer as the doping concentration of lead ion was less than 3%. Meanwhile, the compressive strength of the solidified product ranged from 40 MPa to 50 MPa. Furthermore, by using the same Pb2+ concentration, the geopolymer showed higher compressive strength and lower leaching concentration compared to the cement. Because lead ion participated in constitution of structure of geopolymer, or Pb2+ was adsorbed by the aluminium ions on the geopolymeric skeleton and held in geopolymer. However, cement mainly solidified lead ion by physical encapsulation and adsorption mechanism. Therefore, both from the compressive strength and leaching concentration and from the microstructure characterization as well as the mechanism of the geopolymerization reaction, the geopolymer has more advantages in immobilizing Pb2+ than the cement.

  7. Light transfer in agar immobilized microalgae cell cultures

    Science.gov (United States)

    Kandilian, Razmig; Jesus, Bruno; Legrand, Jack; Pilon, Laurent; Pruvost, Jérémy

    2017-09-01

    This paper experimentally and theoretically investigates light transfer in agar-immobilized cell cultures. Certain biotechnological applications such as production of metabolites secreted by photosynthetic microorganisms require cells to be immobilized in biopolymers to minimize contamination and to facilitate metabolite recovery. In such applications, light absorption by cells is one of the most important parameters affecting cell growth or metabolite productivity. Modeling light transfer therein can aid design and optimize immobilized-cell reactors. In this study, Parachlorella kessleri cells with areal biomass concentrations ranging from 0.36 to 16.9 g/m2 were immobilized in 2.6 mm thick agar gels. The average absorption and scattering cross-sections as well as the scattering phase function of P. kessleri cells were measured. Then, the absorption and transport scattering coefficients of the agar gel were determined using an inverse method based on the modified two-flux approximation. The forward model was used to predict the normal-hemispherical transmittance and reflectance of the immobilized-cell films accounting for absorption and scattering by both microalgae and the agar gel. Good agreement was found between the measured and predicted normal-hemispherical transmittance and reflectance provided absorption and scattering by agar were taken into account. Moreover, good agreement was found between experimentally measured and predicted mean rate of photon absorption. Finally, optimal areal biomass concentration was determined to achieve complete absorption of the incident radiation.

  8. A facile and effective immobilization of glucose oxidase on tannic acid modified CoFe2O4 magnetic nanoparticles.

    Science.gov (United States)

    Altun, Seher; Çakıroğlu, Bekir; Özacar, Münteha; Özacar, Mahmut

    2015-12-01

    This article presents a study of glucose oxidase (GOx) immobilization by employing tannic acid (TA) modified-CoFe2O4 (CFO) magnetic nanoparticles which demonstrates novel aspect for enzyme immobilization. By using the strong protein and tannic acid binding, GOx immobilization was carried out via physical adsorption in a simpler way compared with the other immobilization methods which require various chemicals and complicated procedures which is difficult, expensive, time-consuming, and destructive to the enzyme structure. CFO was synthesized by hydrothermal synthesis and modified with TA to immobilize GOx. The immobilized GOx demonstrated maximum catalytic activity at pH 6.5 and 45 °C. The samples were characterized by vibrating sample magnetometer (VSM), thermogravimetric analysis (TGA), zeta potential, and fourier transform infrared spectroscopy (FTIR), all of which confirm the surface modification of CFO and GOx immobilization. Also, field emission scanning electron microscope (FESEM) and X-ray diffraction (XRD) were performed to demonstrate the surface morphology and chemical structure of samples. According to the Lineweaver-Burk plot, GOx possessed lower affinity to glucose after immobilization, and the Michelis-Menten constant (KM) of immobilized and free GOx were found to be 50.05 mM and 28.00 mM, respectively. The immobilized GOx showed excellent reusability, and even after 8 consecutive activity assay runs, the immobilized GOx maintained ca. 60% of its initial activity.

  9. Histomorphometric analysis of the response of rat skeletal muscle to swimming, immobilization and rehabilitation

    Directory of Open Access Journals (Sweden)

    C.C.F. Nascimento

    2008-09-01

    Full Text Available The objective of the present study was to determine to what extent, if any, swimming training applied before immobilization in a cast interferes with the rehabilitation process in rat muscles. Female Wistar rats, mean weight 260.52 ± 16.26 g, were divided into 4 groups of 6 rats each: control, 6 weeks under baseline conditions; trained, swimming training for 6 weeks; trained-immobilized, swimming training for 6 weeks and then immobilized for 1 week; trained-immobilized-rehabilitated, swimming training for 6 weeks, immobilized for 1 week and then remobilized with swimming for 2 weeks. The animals were then sacrificed and the soleus and tibialis anterior muscles were dissected, frozen in liquid nitrogen and processed histochemically (H&E and mATPase. Data were analyzed statistically by the mixed effects linear model (P < 0.05. Cytoarchitectural changes such as degenerative characteristics in the immobilized group and regenerative characteristics such as centralized nucleus, fiber size variation and cell fragmentation in the groups submitted to swimming were more significant in the soleus muscle. The diameters of the lesser soleus type 1 and type 2A fibers were significantly reduced in the trained-immobilized group compared to the trained group (P < 0.001. In the tibialis anterior, there was an increase in the number of type 2B fibers and a reduction in type 2A fibers when trained-immobilized rats were compared to trained rats (P < 0.001. In trained-immobilized-rehabilitated rats, there was a reduction in type 2B fibers and an increase in type 2A fibers compared to trained-immobilized rats (P < 0.009. We concluded that swimming training did not minimize the deleterious effects of immobilization on the muscles studied and that remobilization did not favor tissue re-adaptation.

  10. Optimization of esterification activity of lipase from Candida rugosa immobilized using microwave irradiation

    Directory of Open Access Journals (Sweden)

    Mihailović Mladen D.

    2012-01-01

    Full Text Available 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 50ºC, initial immobilized enzyme concentration 220 mg ml-1, added water concentration 0.1% (v/v, and molar ratio acid/alcohol 2.5.

  11. Improved Performance of Pseudomonas fluorescens lipase by covalent immobilization onto Amberzyme

    NARCIS (Netherlands)

    Aslan, Yakup; Handayani, Nurrahmi; Stavila, Erythrina; Loos, Katja

    2013-01-01

    Objective: In this study, the conditions of covalent immobilization of Pseudomonas fluorescens lipase onto an oxirane-activated support (Amberzyme) were optimized to obtain a high activity yield. Furthermore, the operational and storage stabilities of immobilized lipase were tested. Methods: Optimum

  12. New Sorbent for Bilirubin Removal from Human Plasma: Albumin Immobilized Microporous Membranous PTFE Capillaries

    Institute of Scientific and Technical Information of China (English)

    Lei ZHANG; Gu JIN

    2005-01-01

    In this study, we developed a tailored capillary sorbent for bilirubin removal. For immobilized bioligand, capillaries were grafted with epoxy groups using RIGP. The HSA immobilized capillaries has a high affinity adsorption capacity (71.2 mg bilirubin/g polymer) and a shorter adsorption equilibrium time (about 60 min).

  13. Optimization of antibody immobilization for on-line or off-line immunoaffinity chromatography

    DEFF Research Database (Denmark)

    Beyer, Natascha Helena; Schou, Christian; Højrup, Peter

    2009-01-01

    . A systematic study was conducted to determine the most versatile antibody immobilization method for use in on-line and off-line IA chromatography applications using commonly accessible immobilization methods. Four chemistries were examined using polyclonal and monoclonal antibodies and antibody fragments. We...

  14. Oxidation of azaheterocycles by free and immobilized xanthine oxedase and xanthis dehydrogenase

    NARCIS (Netherlands)

    Tramper, J.

    1979-01-01

    The objective of the study described in this thesis was to show that enzymes, especially immobilized enzymes, can be advantageously used in synthetic organic chemistry.In Chapter 1 enzymes are introduced and the advantages discussed when these highly active and specific biocatalysts are immobilized,

  15. Immobilization of laccase on hybrid layered double hydroxide

    Directory of Open Access Journals (Sweden)

    David Isidoro Camacho Córdova

    2009-01-01

    Full Text Available Crystals of Mg/Al layered double hydroxide were synthesized by alkaline precipitation and treated in an aqueous solution of glutamic acid. The glutamate ions were not intercalated into the interlayer space, but were detected in the material by Fourier transform infrared spectroscopy, suggesting that only the external surfaces of crystals were modified with glutamate ions. The resulting hybrid material was tested as a support for immobilization of the enzyme laccase (Myceliophthora thermophila. The immobilized enzyme preparation was characterized by electronic paramagnetic resonance spectroscopy and by assays of catalytic activity. The activity of the immobilized laccase was 97% of the activity in the free enzyme. Layered double hydroxide is a suitable support for use in remediation of soil studies.

  16. Straightforward protein immobilization on Sylgard 184 PDMS microarray surface.

    Science.gov (United States)

    Heyries, Kevin A; Marquette, Christophe A; Blum, Loïc J

    2007-04-10

    In this work, a straightforward technique for protein immobilization on Sylgard 184 is described. The method consists of a direct transfer of dried protein/salt solutions to the PDMS interface during the polymer curing. Such non-conventional treatment of proteins was found to have no major negative consequence on their integrity. The mechanisms of this direct immobilization were investigated using a lysine modified dextran molecule as a model. Clear experimental results suggested that both chemical bounding and molding effect were implicated. As a proof of concept study, three different proteins were immobilized on a single microarray (Arachis hypogaea lectin, rabbit IgG, and human IgG) and used as antigens for capture of chemiluminescent immunoassays. The proteins were shown to be easily recognized by their specific antibodies, giving antibody detection limits in the fmol range.

  17. Lipase-immobilized biocatalytic membranes for biodiesel production.

    Science.gov (United States)

    Kuo, Chia-Hung; Peng, Li-Ting; Kan, Shu-Chen; Liu, Yung-Chuan; Shieh, Chwen-Jen

    2013-10-01

    Microbial lipase from Candida rugosa (Amano AY-30) has good transesterification activity and can be used for biodiesel production. In this study, polyvinylidene fluoride (PVDF) membrane was grafted with 1,4-diaminobutane and activated by glutaraldehyde for C. rugosa lipase immobilization. After immobilization, the biocatalytic membrane was used for producing biodiesel from soybean oil and methanol via transesterification. Response Surface Methodology (RSM) in combination with a 5-level-5-factor central composite rotatable design (CCRD) was employed to evaluate the effects of reaction time, reaction temperature, enzyme amount, substrate molar ratio and water content on the yield of soybean oil methyl ester. By ridge max analysis, the predicted and experimental yields under the optimum synthesis conditions were 97% and 95%, respectively. The lipase-immobilized PVDF membrane showed good reuse ability for biodiesel production, enabling operation for at least 165 h during five reuses of the batch, without significant loss of activity.

  18. Gelatin Functionalization of Biomaterial Surfaces: Strategies for Immobilization and Visualization

    Directory of Open Access Journals (Sweden)

    Peter Dubruel

    2011-01-01

    Full Text Available In the present work, the immobilization of gelatin as biopolymer on two types of implantable biomaterials, polyimide and titanium, was compared. Both materials are known for their biocompatibility while lacking cell-interactive behavior. For both materials, a pre-functionalization step was required to enable gelatin immobilization. For the polyimide foils, a reactive succinimidyl ester was introduced first on the surface, followed by covalent grafting of gelatin. For the titanium material, methacrylate groups were first introduced on the Ti surface through a silanization reaction. The applied functionalities enabled the subsequent immobilization of methacrylamide modified gelatin. Both surface modified materials were characterized in depth using atomic force microscopy, static contact angle measurements, confocal fluorescence microscopy, attenuated total reflection infrared spectroscopy and X-ray photo-electron spectroscopy. The results indicated that the strategies elaborated for both material classes are suitable to apply stable gelatin coatings. Interestingly, depending on the material class studied, not all surface analysis techniques are applicable.

  19. [Significance of pain sensitivity for the resistance to immobilization stress].

    Science.gov (United States)

    Zarubina, I V; Shabanov, P D

    2012-01-01

    The effects of immobilization stress (immobilization on back within 4 h) on the functional indexes of Wistar male rats differing with pain sensitivity in the tail-flick test were studied. The acute immobilization stress in rats with high pain sensitivity compared with low pain sensitivity animals produced the most changes of the main functional systems. The high pain sensitivity rats demonstrated more significant hypotension, bradicardia, temperature shift, decrease of breath frequency and oxygen consumption, acid-alkaline equilibrium disorders with lactate acidosis signs. Therefore, the rats with low pain sensitivity possess the high resistance to acute stress exposure in comparison with high pain sensitivity animals. This confirms the important significance of individual pain sensitivity for the formation of stress resistance.

  20. Spectrophotometric Assay of Immobilized Glucose Oxidase

    Directory of Open Access Journals (Sweden)

    Nojan Noorbehesht

    2016-06-01

    Full Text Available Enzyme results in change the substrate of product. Each enzyme may act on specific substrates, resulting in product or different products. The enzyme glucose oxidase (GOX is a bio catalyst. It accelerates the process of transforming glucose into hydrogen peroxide (H2O2 . These enzymes are used in the chemical industry, food industry, cosmetics and kits for diagnosis of glucose. There are many researches about immobilizations of Glucose Oxide to increase specifications such as repeated use, recovery, stability, shelf life and other features In this work, glucose oxidase enzyme using covalent bonding is placed on the carrier of carbon nanotubes. In this study, multi-walled carbon nanotubes have been used as adsorbents. Also, carbon nanotubes have been functionalized by sulfuric acid and nitric acid with a high concentration. Glucose oxidase is a biological biocatalyst enzyme. It accelerates changing glucose to H2O2. This enzyme is used in the chemical industry, food industry, cosmetics and glucose diagnostic kits. For example, as a result of ongoing research working focuses on the development of glucose biosensors, GOX in practice as standard enzyme has been revealed for immobilization of oxidative enzyme.GOX correct fixation on the MWNTs carrier is a way to reuse enzyme and miniature of biosensor devices and structures. In this study, a spectrophotometer was used to determine the absorbance of the enzyme glucose oxidase (GOX to review its activities after stabilizing the carbon nanotubes.

  1. Enhancement of Alkaline Protease Activity and Stability via Covalent Immobilization onto Hollow Core-Mesoporous Shell Silica Nanospheres

    Directory of Open Access Journals (Sweden)

    Abdelnasser Salah Shebl Ibrahim

    2016-01-01

    Full Text Available The stability and reusability of soluble enzymes are of major concerns, which limit their industrial applications. Herein, alkaline protease from Bacillus sp. NPST-AK15 was immobilized onto hollow core-mesoporous shell silica (HCMSS nanospheres. Subsequently, the properties of immobilized proteases were evaluated. Non-, ethane- and amino-functionalized HCMSS nanospheres were synthesized and characterized. NPST-AK15 was immobilized onto the synthesized nano-supports by physical and covalent immobilization approaches. However, protease immobilization by covalent attachment onto the activated HCMSS–NH2 nanospheres showed highest immobilization yield (75.6% and loading capacity (88.1 μg protein/mg carrier and was applied in the further studies. In comparison to free enzyme, the covalently immobilized protease exhibited a slight shift in the optimal pH from 10.5 to 11.0, respectively. The optimum temperature for catalytic activity of both free and immobilized enzyme was seen at 60 °C. However, while the free enzyme was completely inactivated when treated at 60 °C for 1 h the immobilized enzyme still retained 63.6% of its initial activity. The immobilized protease showed higher Vmax, kcat and kcat/Km, than soluble enzyme by 1.6-, 1.6- and 2.4-fold, respectively. In addition, the immobilized protease affinity to the substrate increased by about 1.5-fold. Furthermore, the enzyme stability in various organic solvents was significantly enhanced upon immobilization. Interestingly, the immobilized enzyme exhibited much higher stability in several commercial detergents including OMO, Tide, Ariel, Bonux and Xra by up to 5.2-fold. Finally, the immobilized protease maintained significant catalytic efficiency for twelve consecutive reaction cycles. These results suggest the effectiveness of the developed nanobiocatalyst as a candidate for detergent formulation and peptide synthesis in non-aqueous media.

  2. Enhancement of Alkaline Protease Activity and Stability via Covalent Immobilization onto Hollow Core-Mesoporous Shell Silica Nanospheres.

    Science.gov (United States)

    Ibrahim, Abdelnasser Salah Shebl; Al-Salamah, Ali A; El-Toni, Ahmed M; Almaary, Khalid S; El-Tayeb, Mohamed A; Elbadawi, Yahya B; Antranikian, Garabed

    2016-01-29

    The stability and reusability of soluble enzymes are of major concerns, which limit their industrial applications. Herein, alkaline protease from Bacillus sp. NPST-AK15 was immobilized onto hollow core-mesoporous shell silica (HCMSS) nanospheres. Subsequently, the properties of immobilized proteases were evaluated. Non-, ethane- and amino-functionalized HCMSS nanospheres were synthesized and characterized. NPST-AK15 was immobilized onto the synthesized nano-supports by physical and covalent immobilization approaches. However, protease immobilization by covalent attachment onto the activated HCMSS-NH₂ nanospheres showed highest immobilization yield (75.6%) and loading capacity (88.1 μg protein/mg carrier) and was applied in the further studies. In comparison to free enzyme, the covalently immobilized protease exhibited a slight shift in the optimal pH from 10.5 to 11.0, respectively. The optimum temperature for catalytic activity of both free and immobilized enzyme was seen at 60 °C. However, while the free enzyme was completely inactivated when treated at 60 °C for 1 h the immobilized enzyme still retained 63.6% of its initial activity. The immobilized protease showed higher V(max), k(cat) and k(cat)/K(m), than soluble enzyme by 1.6-, 1.6- and 2.4-fold, respectively. In addition, the immobilized protease affinity to the substrate increased by about 1.5-fold. Furthermore, the enzyme stability in various organic solvents was significantly enhanced upon immobilization. Interestingly, the immobilized enzyme exhibited much higher stability in several commercial detergents including OMO, Tide, Ariel, Bonux and Xra by up to 5.2-fold. Finally, the immobilized protease maintained significant catalytic efficiency for twelve consecutive reaction cycles. These results suggest the effectiveness of the developed nanobiocatalyst as a candidate for detergent formulation and peptide synthesis in non-aqueous media.

  3. Immobilization of Penaeus merguiensis alkaline phosphatase on gold nanorods for heavy metal detection.

    Science.gov (United States)

    Homaei, Ahmad

    2017-02-01

    Biotechnology of enzyme has gained popularity due to the growing need for novel environmental technologies and the development of innovative mass-production. The work describes the original application of biosensors based on Penaeus merguiensis alkaline phosphatase (PM ALP) immobilized on gold nanorods (GNRs) to heavy metal determination. Penaeus merguiensis alkaline phosphatase (PM ALP) was immobilized on gold nanorods (GNRs) by ionic exchange and hydrophobic interactions. The optimum pH and temperature for maximum enzyme activity for the immobilized PM ALP are identified to be 11.0 and 60°C, respectively, for the hydrolysis of para-Nitrophenylphosphate (p-NPP). The kinetic studies confirm the Michaelis-Menten behavior and suggests overall slightly decrease in the performance of the immobilized enzyme with reference to the free enzyme. Km and Vmax values were 0.32µm and 54µm. min(-1) for free and 0.39µm and 48µmmin(-1) for immobilized enzymes, respectively. Similarly, the thermal stability, storage stability and stability at extreme pH of the enzyme is found to increase after the immobilization. The inhibitory effect heavy metal ions was studied on free and immobilized PM ALP. The bi-enzymatic biosensor were tested to study the influence of heavy metal ions and pesticides on the corresponding enzyme. The obtained high stability and lower decrease in catalytic efficiency suggested the great potential and feasibility of immobilized PM ALP nanobiocatalyst in efficient and apply the biosensor in total toxic metal content determination.

  4. Utilization of immobilized urease for waste water treatment

    Science.gov (United States)

    Husted, R. R.

    1974-01-01

    The feasibility of using immobilized urease for urea removal from waste water for space system applications is considered, specifically the elimination of the urea toxicity problem in a 30-day Orbiting Frog Otolith (OFO) flight experiment. Because urease catalyzes the hydrolysis of urea to ammonia and carbon dioxide, control of their concentrations within nontoxic limits was also determined. The results of this study led to the use of free urease in lieu of the immobilized urease for controlling urea concentrations. An ion exchange resin was used which reduced the NH3 level by 94% while reducing the sodium ion concentration only 10%.

  5. Analysis of alternatives for immobilized low activity waste disposal

    Energy Technology Data Exchange (ETDEWEB)

    Burbank, D.A.

    1997-10-28

    This report presents a study of alternative disposal system architectures and implementation strategies to provide onsite near-surface disposal capacity to receive the immobilized low-activity waste produced by the private vendors. The analysis shows that a flexible unit strategy that provides a suite of design solutions tailored to the characteristics of the immobilized low-activity waste will provide a disposal system that best meets the program goals of reducing the environmental, health, and safety impacts; meeting the schedule milestones; and minimizing the life-cycle cost of the program.

  6. Esterification of phenolic acids catalyzed by lipases immobilized in organogels.

    Science.gov (United States)

    Zoumpanioti, M; Merianou, E; Karandreas, T; Stamatis, H; Xenakis, A

    2010-10-01

    Lipases from Rhizomucor miehei and Candida antarctica B were immobilized in hydroxypropylmethyl cellulose organogels based on surfactant-free microemulsions consisting of n-hexane, 1-propanol and water. Both lipases kept their catalytic activity, catalyzing the esterification reactions of various phenolic acids including cinnamic acid derivatives. High reaction rates and yields (up to 94%) were obtained when lipase from C. antarctica was used. Kinetic studies have been performed and apparent kinetic constants were determined showing that ester synthesis catalyzed by immobilized lipases occurs via the Michaelis-Menten mechanism.

  7. Dynamics of Immobilized Flagella

    CERN Document Server

    Fry, D; Ludu, A

    2003-01-01

    Although the auger-like 'swimming' motility of the African trypanosome was described upon its discovery over one hundred years ago, the precise biomechanical and biophysical properties of trypanosome flagellar motion has not been elucidated. In this study, we describe five different modes of flagellar beat/wave patterns in African trypanosomes by microscopically examining the flagellar movements of chemically tethered cells. The dynamic nature of the different beat/wave patterns suggests that flagellar motion in Trypanosoma brucei is a complex mixture of oscillating waves, rigid bends, helical twists and non-linear waves. Interestingly, we have observed soliton-like depression waves along the flagellar membrane, suggesting a nonlinear mechanism for the dynamics of this system. The physical model is inspired by the 2-dimensional elastic dynamics of a beam, and by taking into account uniform distribution of molecular motors torque and nonlinear terms in the curvature.

  8. Immobilization of α-amylase onto a calix[4]arene derivative: Evaluation of its enzymatic activity.

    Science.gov (United States)

    Veesar, Irshad Ali; Solangi, Imam Bakhsh; Memon, Shahabuddin

    2015-06-01

    In order to enhance the cost-effectiveness practicability of enzymes in many industries such as pharmaceutical, food, medical and some other technological processes, there is great need to immobilize them onto a solid supports. In this study, a new and efficient immobilization of α-amylase from Saccharomyces cerevisiae has been developed by using the surface functionalization of calix[4]arene as support. A glutaraldehyde-containing amino group functionalized calix[4]arene was used to immobilize α-amylase covalently. In this procedure, imide bonds are formed between amino groups on the protein and aldehyde groups on the calix[4]arene surface. The surface modified support was characterized using Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM). The effect of various preparation conditions on the immobilized α-amylase process such as immobilization time, enzyme concentration, temperature and pH were investigated. The influence of pH and temperature on the activity of free and immobilized α-amylase was also studied using starch as substrate. The optimum reaction temperature and pH value for the enzymatic conversion catalyzed by the immobilized α-amylase were 25°C and 7, respectively. Compared to the free enzyme, the immobilized α-amylase retained 85% of its original activity and exhibited significant thermal stability than the free one and excellent durability. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Alginate immobilized enrichment culture for atrazine degradation in soil and water system.

    Science.gov (United States)

    Kumar, Anup; Nain, Lata; Singh, Neera

    2017-04-03

    An atrazine degrading enrichment culture, a consortium of bacteria of genus Bacillus along with Pseudomonas and Burkholderia, was immobilized in sodium alginate and was used to study atrazine degradation in mineral salts medium (MSM), soil and wastewater effluent. Sodium alginate immobilized consortium, when stored at room temperature (24 ± 5°C), was effective in degrading atrazine in MSM up to 90 days of storage. The survival of bacteria in alginate beads, based on colony formation unit (CFU) counts, suggested survival up to 90 days and population counts decreased to 1/5(th) on 120 days. Comparison of atrazine degrading ability of the freely suspended enrichment culture and immobilized culture suggested that the immobilized culture took longer time for complete degradation of atrazine as a lag phase of 2 days was observed in the MSM inoculated with alginate immobilized culture. The free cells resulted in complete degradation of atrazine within 6 days, while immobilized cells took 10 days for 100% atrazine degradation. Further, immobilized cultures were able to degrade atrazine in soil and wastewater effluent. Alginate beads were stable and effective in degrading atrazine till 3rd transfer and disintegrated thereafter. The study suggested that immobilized enrichment culture, due to its better storage and application, can be used to degrade atrazine in soil water system.

  10. Long-term repeated biodesulfurization by immobilized Rhodococcus erythropolis KA2-5-1 cells

    Energy Technology Data Exchange (ETDEWEB)

    Naito, M.; Kawamoto, T.; Tanaka, A. [Kyoto Univ., Yoshida (Japan). Dept. of Synthetic Chemistry and Biological Chemistry; Fujino, K.; Kobayashi, M.; Maruhashi, K. [Advanced Technology and Research Inst., Petroleum Energy Center, Shizuoka (Japan)

    2001-07-01

    In this study, biodesulfurization (BDS) was carried out using immobilized Rhodococcus erythropolis KA2-5-1 in n-tetradecane containing dibenzothiophene (DBT) as a model oil (n-tetradecane/immobilized cell biphasic system). The cells were immobilized by entrapping them with calcium alginate, agar, photo-crosslinkable resin prepolymers (ENT-4000 and ENTP-4000), and urethane prepolymers (PU-3 and PU-6); and it was found that ENT-4000-immobilized cells had the highest DBT desulfurization activity in the model oil system without leakage of cells from the support. Furthermore, ENT-4000-immobilized cells could catalyze BDS repeatedly in this system for more than 900 h with reactivation; and recovery of both the biocatalyst and the desulfurized model oil was easy. This study would give a solution to the problems in BDS, such as the troublesome process of recovering desulfurized oil and the short life of BDS biocatalysts. (orig.)

  11. The adsorption of silver nanoparticles on the proteins-immobilized glass slides and a visual investigation on proteins immobilization

    Institute of Scientific and Technical Information of China (English)

    LIU Yue; LING Jian; LI YuanFang; HUANG ChengZhi

    2009-01-01

    Silver nanoparticles (AgNPs), owing to the property of plasmon resonance light scattering (PRLS), can be used as a light scattering spectral probe for visually tracing and detecting target molecules. In this study, we investigated the adsorption features of proteins immobilized on glass slides for AgNPs, and found that the scattering light of AgNPs adsorbed on the surface of glass slides could be seen by na-ked eyes under the irradiation of a common white light-emitting diode (LED) torch. Hereby, we estab-lished a method for visually determining the least complete quantity of immobilization of proteins on glass slides.

  12. Synthesis and heavy metal immobilization behaviors of slag based geopolymer.

    Science.gov (United States)

    Yunsheng, Zhang; Wei, Sun; Qianli, Chen; Lin, Chen

    2007-05-08

    In this paper, two aspects of studies are carried out: (1) synthesis of geopolymer by using slag and metakaolin; (2) immobilization behaviors of slag based geopolymer in a presence of Pb and Cu ions. As for the synthesis of slag based geopolymer, four different slag content (10%, 30%, 50%, 70%) and three types of curing regimes (standard curing, steam curing and autoclave curing) are investigated to obtain the optimum synthesis condition based on the compressive and flexural strength. The testing results showed that geopolymer mortar containing 50% slag that is synthesized at steam curing (80 degrees C for 8h), exhibits higher mechanical strengths. The compressive and flexural strengths of slag based geopolymer mortar are 75.2 MPa and 10.1 MPa, respectively. Additionally, Infrared (IR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques are used to characterize the microstructure of the slag based geopolymer paste. IR spectra show that the absorptive band at 1086 cm(-1) shifts to lower wave number around 1007 cm(-1), and some six-coordinated Als transforms into four-coordination during the synthesis of slag based geopolymer paste. The resulting slag based geopolymeric products are X-ray amorphous materials. SEM observation shows that it is possible to have geopolymeric gel and calcium silicate hydrate (C-S-H) gel forming simultaneously within slag based geopolymer paste. As for immobilization of heavy metals, the leaching tests are employed to investigate the immobilization behaviors of the slag based geopolymer mortar synthesized under the above optimum condition. The leaching tests show that slag based geopolymer mortar can effectively immobilize Cu and Pb heavy metal ions, and the immobilization efficiency reach 98.5% greater when heavy metals are incorporated in the slag geopolymeric matrix in the range of 0.1-0.3%. The Pb exhibits better immobilization efficiency than the Cu in the case of large dosages of heavy metals.

  13. Venous Thrombosis Risk after Cast Immobilization of the Lower Extremity: Derivation and Validation of a Clinical Prediction Score, L-TRiP(cast, in Three Population-Based Case-Control Studies.

    Directory of Open Access Journals (Sweden)

    Banne Nemeth

    2015-11-01

    Full Text Available Guidelines and clinical practice vary considerably with respect to thrombosis prophylaxis during plaster cast immobilization of the lower extremity. Identifying patients at high risk for the development of venous thromboembolism (VTE would provide a basis for considering individual thromboprophylaxis use and planning treatment studies. The aims of this study were (1 to investigate the predictive value of genetic and environmental risk factors, levels of coagulation factors, and other biomarkers for the occurrence of VTE after cast immobilization of the lower extremity and (2 to develop a clinical prediction tool for the prediction of VTE in plaster cast patients.We used data from a large population-based case-control study (MEGA study, 4,446 cases with VTE, 6,118 controls without designed to identify risk factors for a first VTE. Cases were recruited from six anticoagulation clinics in the Netherlands between 1999 and 2004; controls were their partners or individuals identified via random digit dialing. Identification of predictor variables to be included in the model was based on reported associations in the literature or on a relative risk (odds ratio > 1.2 and p ≤ 0.25 in the univariate analysis of all participants. Using multivariate logistic regression, a full prediction model was created. In addition to the full model (all variables, a restricted model (minimum number of predictors with a maximum predictive value and a clinical model (environmental risk factors only, no blood draw or assays required were created. To determine the discriminatory power in patients with cast immobilization (n = 230, the area under the curve (AUC was calculated by means of a receiver operating characteristic. Validation was performed in two other case-control studies of the etiology of VTE: (1 the THE-VTE study, a two-center, population-based case-control study (conducted in Leiden, the Netherlands, and Cambridge, United Kingdom with 784 cases and 523

  14. Venous Thrombosis Risk after Cast Immobilization of the Lower Extremity: Derivation and Validation of a Clinical Prediction Score, L-TRiP(cast), in Three Population-Based Case–Control Studies

    Science.gov (United States)

    Nemeth, Banne; van Adrichem, Raymond A.; van Hylckama Vlieg, Astrid; Bucciarelli, Paolo; Martinelli, Ida; Baglin, Trevor; Rosendaal, Frits R.; le Cessie, Saskia; Cannegieter, Suzanne C.

    2015-01-01

    Background Guidelines and clinical practice vary considerably with respect to thrombosis prophylaxis during plaster cast immobilization of the lower extremity. Identifying patients at high risk for the development of venous thromboembolism (VTE) would provide a basis for considering individual thromboprophylaxis use and planning treatment studies. The aims of this study were (1) to investigate the predictive value of genetic and environmental risk factors, levels of coagulation factors, and other biomarkers for the occurrence of VTE after cast immobilization of the lower extremity and (2) to develop a clinical prediction tool for the prediction of VTE in plaster cast patients. Methods and Findings We used data from a large population-based case–control study (MEGA study, 4,446 cases with VTE, 6,118 controls without) designed to identify risk factors for a first VTE. Cases were recruited from six anticoagulation clinics in the Netherlands between 1999 and 2004; controls were their partners or individuals identified via random digit dialing. Identification of predictor variables to be included in the model was based on reported associations in the literature or on a relative risk (odds ratio) > 1.2 and p ≤ 0.25 in the univariate analysis of all participants. Using multivariate logistic regression, a full prediction model was created. In addition to the full model (all variables), a restricted model (minimum number of predictors with a maximum predictive value) and a clinical model (environmental risk factors only, no blood draw or assays required) were created. To determine the discriminatory power in patients with cast immobilization (n = 230), the area under the curve (AUC) was calculated by means of a receiver operating characteristic. Validation was performed in two other case–control studies of the etiology of VTE: (1) the THE-VTE study, a two-center, population-based case–control study (conducted in Leiden, the Netherlands, and Cambridge, United Kingdom

  15. Study on carrier-bound immobilized enzyme for OPH biosensor%有机磷水解酶生物传感器载体固定化酶的研究

    Institute of Scientific and Technical Information of China (English)

    邱晓丽; 郭康权; 项方献; 伍宁丰

    2009-01-01

    有机磷水解酶(OPH)传感器作为检测农产品中农药残留的新型检测装置,其酶的固定化对OPH传感器的灵敏度和稳定性有重要的影响.研究了几种酶固定化载体、孔径大小、固定方式、固定方法(试剂组成)对传感器pH值的影响.结果显示:采用孔径为0.45 μm的硝酸纤维素膜制备固定化酶片的pH值要大于其余几种;采用浸泡方式制备固定化酶片的pH值明显大于传统的滴定法;采用牛血清白蛋白(BSA)、戊二醛交联固定的效果优于酶直接吸附法和BSA固定法,且当戊二醛体积分数为2.5%,BSA为10%时,酶固定化效果最好.%Immobilized enzyme has an important impact on sensitivity and stability of organophosphorus hydrolase biosensor, which is a new kind of detection device for detecting organophosphorus pesticide residues in agricultural products. The impact of carrier-bound type,pore size as well as enzyme immobilized methods/ways and means on the diversification capacity of pH are studied. The results show that the diversification capacity of pH caused by 0.45 祄 nitrocellulose membrane is better than other carrier-bound types;immersion ways is greater than titration; the immobility ability of bovine serum albumin-glutaraldehyde cross-linking method is better than both simple physical adsorption and bovine serum albumin ( BSA) immobilization method, and the best result is got when the volume fraction of glutaraldehyde and BSA is 2.5 % and 10 % respectively.

  16. Ethanol production from concentrated food waste hydrolysates with yeast cells immobilized on corn stalk.

    Science.gov (United States)

    Yan, Shoubao; Chen, Xiangsong; Wu, Jingyong; Wang, Pingchao

    2012-05-01

    The aim of the present study was to examine ethanol production from concentrated food waste hydrolysates using whole cells of S. cerevisiae immobilized on corn stalks. In order to improve cell immobilization efficiency, biological modification of the carrier was carried out by cellulase hydrolysis. The results show that proper modification of the carrier with cellulase hydrolysis was suitable for cell immobilization. The mechanism proposed, cellulase hydrolysis, not only increased the immobilized cell concentration, but also disrupted the sleek surface to become rough and porous, which enhanced ethanol production. In batch fermentation with an initial reducing sugar concentration of 202.64 ± 1.86 g/l, an optimal ethanol concentration of 87.91 ± 1.98 g/l was obtained using a modified corn stalk-immobilized cell system. The ethanol concentration produced by the immobilized cells was 6.9% higher than that produced by the free cells. Ethanol production in the 14th cycle repeated batch fermentation demonstrated the enhanced stability of the immobilized yeast cells. Under continuous fermentation in an immobilized cell reactor, the maximum ethanol concentration of 84.85 g/l, and the highest ethanol yield of 0.43 g/g (of reducing sugar) were achieved at hydraulic retention time (HRT) of 3.10 h, whereas the maximum volumetric ethanol productivity of 43.54 g/l/h was observed at a HRT of 1.55 h.

  17. Enzymatic decolorization of anthraquinone and diazo dyes using horseradish peroxidase enzyme immobilized onto various polysulfone supports.

    Science.gov (United States)

    Celebi, Mithat; Kaya, Mehmet Arif; Altikatoglu, Melda; Yildirim, Huseyin

    2013-10-01

    In this study, covalent immobilization of the horseradish peroxidase (HRP) onto various polysulfone supports was investigated. For this purpose, different polysulfones were methacrylated with methacryloyl chloride, and then, nonwoven fabric samples were coated by using solutions of these methacrylated polysulfones. Finally, support materials were immersed into aquatic solution of HRP enzyme for covalent immobilization. Structural analysis of enzyme immobilization onto various polysulfones was confirmed with Fourier transform infrared spectroscopy, atomic force microscopy, and proton nuclear magnetic resonance spectroscopy. Decolorization of textile diazo (Acid Black 1) and anthraquinone (Reactive Blue 19) dyes was investigated by UV-visible spectrophotometer. Covalently immobilized enzyme has been used seven times in freshly prepared dye solutions through 63 days. Dye decolorization performance of the immobilized systems was observed that still remained high (70%) after reusing three times. Enzyme activities of immobilized systems were determined and compared to free enzyme activity at different conditions (pH, temperature, thermal stability, storage stability). Enzyme activities of immobilized systems and free enzyme were also investigated at the different temperatures and effects of temperature and thermal resistance for different incubation time at 50 °C. In addition, storage activity of free and immobilized enzymes was determined at 4 °C at different incubation days.

  18. Aerobic degradation of nitrobenzene by immobilization of Rhodotorula mucilaginosa in polyurethane foam.

    Science.gov (United States)

    Zheng, Chunli; Zhou, Jiti; Wang, Jing; Qu, Baocheng; Wang, Jing; Lu, Hong; Zhao, Hongxia

    2009-08-30

    Rhodotorula mucilaginosa Z1 capable of degrading nitrobenzene was immobilized in polyurethane foam. The nitrobenzene-degrading capacity of immobilized cells was compared to free cells in batches in shaken culture. Effects of pH and temperature on the nitrobenzene degradation showed that polyurethane-immobilized Z1 had higher tolerances toward acid, alkali, and heat than those of free cells. Kinetic studies revealed that higher concentrations of nitrobenzene were better tolerated and more quickly degraded by polyurethane-immobilized Z1 than by free cells. Moreover, the ability of polyurethane-immobilized Z1 to resist nitrobenzene shock load was enhanced. Experiments on the nitrobenzene degradation in different concentrations of NaCl and in the presence of phenol or aniline demonstrated that polyurethane-immobilized Z1 exhibited higher tolerance toward salinity and toxic chemicals than those of free cells. Immobilization therefore could be a promising method for treating nitrobenzene industrial wastewater. This is the first report on the degradation of nitrobenzene by a polyurethane-immobilized yeast strain.

  19. Immobilization of tropizyme-P on amino-functionalized magnetic nanoparticles for fruit juice clarification

    Directory of Open Access Journals (Sweden)

    Mayur R Ladole

    2014-12-01

    Full Text Available Nowadays nanoparticles are widely used as a key tool for enzyme immobilization. Tropizyme-P, a pectolytic enzyme was successfully immobilized on amino functionalized magnetic nanoparticles (AMNPs using glutaraldehyde as a cross-linking agent at 15 mM concentration and 4h cross-linking time. The average size of the synthesized AMNPs was found below 80 nm by particle size analyzer. The binding of tropizyme-P on nanoparticles was confirmed by FTIR spectroscopy. SEM analysis revealed that there was no significance difference in the size of nanoparticles after tropizyme-P immobilization. XRD results showed no phase change in nanoparticles after enzyme immobilization. Physical parameters viz. pH and temperature were optimized. The pH was found to be same and there was shift in optimum temperature of immobilized tropizyme-P by 5ºC. Immobilized tropizyme-P had more thermal stability than free one. The kinetic studies revealed an increase in Vmax of the immobilized enzyme. Reusability of immobilized tropizyme-P was found to retain upto 85% of initial activity after sixth cycles of reuse.

  20. Ethanol production from concentrated food waste hydrolysates with yeast cells immobilized on corn stalk

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Shoubao [Huainan Normal Univ., Anhui (China). School of Life Science; Chen, Xiangsong; Wu, Jingyong; Wang, Pingchao [Chinese Academy of Sciences, Hefei (China). Key Lab. of Ion Beam Bio-engineering of Inst. of Plasma Physics

    2012-05-15

    The aim of the present study was to examine ethanol production from concentrated food waste hydrolysates using whole cells of S. cerevisiae immobilized on corn stalks. In order to improve cell immobilization efficiency, biological modification of the carrier was carried out by cellulase hydrolysis. The results show that proper modification of the carrier with cellulase hydrolysis was suitable for cell immobilization. The mechanism proposed, cellulase hydrolysis, not only increased the immobilized cell concentration, but also disrupted the sleek surface to become rough and porous, which enhanced ethanol production. In batch fermentation with an initial reducing sugar concentration of 202.64 {+-} 1.86 g/l, an optimal ethanol concentration of 87.91 {+-} 1.98 g/l was obtained using a modified corn stalk-immobilized cell system. The ethanol concentration produced by the immobilized cells was 6.9% higher than that produced by the free cells. Ethanol production in the 14th cycle repeated batch fermentation demonstrated the enhanced stability of the immobilized yeast cells. Under continuous fermentation in an immobilized cell reactor, the maximum ethanol concentration of 84.85 g/l, and the highest ethanol yield of 0.43 g/g (of reducing sugar) were achieved at hydraulic retention time (HRT) of 3.10 h, whereas the maximum volumetric ethanol productivity of 43.54 g/l/h was observed at a HRT of 1.55 h. (orig.)

  1. Immobilization of α-amylase onto poly(glycidyl methacrylate) grafted electrospun fibers by ATRP

    Energy Technology Data Exchange (ETDEWEB)

    Oktay, Burcu; Demir, Serap; Kayaman-Apohan, Nilhan, E-mail: napohan@marmara.edu.tr

    2015-05-01

    In this study, novel α-amylase immobilized poly(vinyl alcohol) (PVA) nanofibers were prepared. The PVA nanofiber surfaces were functionalized with 2-bromoisobutyryl bromide (BiBBr) and followed by surface initiated atom transfer radical polymerization (SI-ATRP) of glycidyl methacrylate (GMA). The morphology of the poly(glycidyl methacrylate) (PGMA) grafted PVA nanofibers was characterized by scanning electron microscopy (SEM). Also PGMA brushes were confirmed by X-ray photo electron microscopy (XPS). α-Amylase was immobilized in a one step process onto the PGMA grafted PVA nanofiber. The characteristic properties of the immobilized and free enzymes were examined. The thermal stability of the enzyme was improved and showed maximum activity at 37 °C by immobilization. pH values of the maximum activity of the free and immobilized enzymes were also found at 6.0 and 6.5, respectively. Free enzyme lost its activity completely within 15 days. The immobilized enzyme lost only 23.8% of its activity within 30 days. - Highlights: • Electrospun photocrosslinkable PVA nanofiber was prepared. • PGMA brushes were conducted on PVA nanofiber via SI-ATRP. • The immobilized enzyme showed maximum activity at pH 6.0 and at 37 °C. • Functionalized nanofibers may be used as promising supports for enzyme immobilization.

  2. Cagelike mesoporous silica encapsulated with microcapsules for immobilized laccase and 2, 4-DCP degradation.

    Science.gov (United States)

    Yang, Junya; Huang, Yan; Yang, Yuxiang; Yuan, Hongming; Liu, Xiangnong

    2015-12-01

    In this study, cage-like mesoporous silica was used as the carrier to immobilize laccase by a physical approach, followed by encapsulating with chitosan/alginate microcapsule membranes to form microcapsules of immobilized laccase based on layer-by-layer technology. The relationship between laccase activity recovery/leakage rate and the coating thickness was simultaneously investigated. Because the microcapsule layers have a substantial network of pores, they act as semipermeable membranes, while the laccase immobilized inside the microcapsules acts as a processing plant for degradation of 2,4-dichlorophenol. The microcapsules of immobilized laccase were able to degrade 2,4-dichlorophenol within a wide range of 2,4-dichlorophenol concentration, temperature and pH, with mean degradation rate around 62%. Under the optimal conditions, the thermal stability and reusability of immobilized laccase were shown to be improved significantly, as the removal rate and degradation rate remained over 40.2% and 33.8% respectively after 6cycles of operation. Using mass spectrometry (MS) and nuclear magnetic resonance (NMR), diisobutyl phthalate and dibutyl phthalate were identified as the products of 2,4-dichlorophenol degradation by the microcapsules of immobilized laccase and laccase immobilized by a physical approach, respectively, further demonstrating the degradation mechanism of 2,4-dichlorophenol by microcapsule-immobilized laccase.

  3. Influence of acetylcholinesterase immobilization on the photoluminescence properties of mesoporous silicon surface

    Science.gov (United States)

    Saleem, Muhammad; Rafiq, Muhammad; Seo, Sung-Yum; Lee, Ki Hwan

    2014-07-01

    Acetylcholinesterase immobilized p-type porous silicon surface was prepared by covalent attachment. The immobilization procedure was based on support surface chemical oxidation, silanization, surface activation with cyanuric chloride and finally covalent attachment of free enzyme on the cyanuric chloride activated porous silicon surface. Different pore diameter of porous silicon samples were prepared by electrochemical etching in HF based electrolyte solution and appropriate sample was selected suitable for enzyme immobilization with maximum trapping ability. The surface modification was studied through field emission scanning electron microscope, EDS, FT-IR analysis, and photoluminescence measurement by utilizing the fluctuation in the photoluminescence of virgin and enzyme immobilized porous silicon surface. Porous silicon showed strong photoluminescence with maximum emission at 643 nm and immobilization of acetylcholinesterase on porous silicon surface cause considerable increment on the photoluminescence of porous silicon material while acetylcholinesterase free counterpart did not exhibit any fluorescence in the range of 635-670 nm. The activities of the free and immobilized enzymes were evaluated by spectrophotometric method by using neostigmine methylsulfate as standard enzyme inhibitor. The immobilized enzyme exhibited considerable response toward neostigmine methylsulfate in a dose dependent manner comparable with that of its free counterpart alongside enhanced stability, easy separation from the reaction media and significant saving of enzyme. It was believed that immobilized enzyme can be exploited in organic and biomolecule synthesis possessing technical and economical prestige over free enzyme and prominence of easy separation from the reaction mixture.

  4. Influence of acetylcholinesterase immobilization on the photoluminescence properties of mesoporous silicon surface

    Energy Technology Data Exchange (ETDEWEB)

    Saleem, Muhammad [Department of Chemistry, Kongju National University, Gongju, Chungnam 314-701 (Korea, Republic of); Rafiq, Muhammad; Seo, Sung-Yum [Department of Biology, Kongju National University, Gongju, Chungnam 314-701 (Korea, Republic of); Lee, Ki Hwan, E-mail: khlee@kongju.ac.kr [Department of Chemistry, Kongju National University, Gongju, Chungnam 314-701 (Korea, Republic of)

    2014-07-01

    Acetylcholinesterase immobilized p-type porous silicon surface was prepared by covalent attachment. The immobilization procedure was based on support surface chemical oxidation, silanization, surface activation with cyanuric chloride and finally covalent attachment of free enzyme on the cyanuric chloride activated porous silicon surface. Different pore diameter of porous silicon samples were prepared by electrochemical etching in HF based electrolyte solution and appropriate sample was selected suitable for enzyme immobilization with maximum trapping ability. The surface modification was studied through field emission scanning electron microscope, EDS, FT-IR analysis, and photoluminescence measurement by utilizing the fluctuation in the photoluminescence of virgin and enzyme immobilized porous silicon surface. Porous silicon showed strong photoluminescence with maximum emission at 643 nm and immobilization of acetylcholinesterase on porous silicon surface cause considerable increment on the photoluminescence of porous silicon material while acetylcholinesterase free counterpart did not exhibit any fluorescence in the range of 635–670 nm. The activities of the free and immobilized enzymes were evaluated by spectrophotometric method by using neostigmine methylsulfate as standard enzyme inhibitor. The immobilized enzyme exhibited considerable response toward neostigmine methylsulfate in a dose dependent manner comparable with that of its free counterpart alongside enhanced stability, easy separation from the reaction media and significant saving of enzyme. It was believed that immobilized enzyme can be exploited in organic and biomolecule synthesis possessing technical and economical prestige over free enzyme and prominence of easy separation from the reaction mixture.

  5. Polydopamine-mediated immobilization of multiple bioactive molecules for the development of functional vascular graft materials.

    Science.gov (United States)

    Lee, Yu Bin; Shin, Young Min; Lee, Ji-Hye; Jun, Indong; Kang, Jae Kyeong; Park, Jong-Chul; Shin, Heungsoo

    2012-11-01

    In this study, we introduced a simple method for polydopamine-mediated immobilization of dual bioactive factors for the preparation of functionalized vascular graft materials. Polydopamine was deposited on elastic and biodegradable poly(lactic acid-co-ɛ-caprolactone) (PLCL) films, and a cell adhesive RGD-containing peptide and basic fibroblast growth factor were subsequently immobilized by simple dipping. We used an enzyme-linked immunosorbent assay and fluorescamine assay to confirm that we had stably immobilized bioactive molecules on the polydopamine-coated PLCL film in a reaction time-dependent manner. When human umbilical vein endothelial cells (HUVEC) were cultured on the prepared substrates, the number of adherent cells and proliferation of HUVEC for up to 14 days were greatest on the film immobilized with dual factors. On the other hand, the film immobilized with RGD peptide exhibited the highest migration speed compared to the other groups. The expression of cluster of differentiation 31 and von Willebrand factor, which indicates maturation of endothelial cells, was highly stimulated in the dual factor-immobilized group, and passively adsorbed factors showed a negligible effect. The immobilization of bioactive molecules inspired by polydopamine was successful, and adhesion, migration, proliferation and differentiation of HUVEC were synergistically accelerated by the presence of multiple signaling factors. Collectively, our results have demonstrated that a simple coating with polydopamine enables the immobilization of multiple bioactive molecules for preparation of polymeric functionalized vascular graft materials. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. Magnetic catechol-chitosan with bioinspired adhesive surface: preparation and immobilization of ω-transaminase.

    Directory of Open Access Journals (Sweden)

    Kefeng Ni

    Full Text Available The magnetic chitosan nanocomposites have been studied intensively and been used practically in various biomedical and biological applications including enzyme immobilization. However, the loading capacity and the remained activity of immobilized enzyme based on existing approaches are not satisfied. Simpler and more effective immobilization strategies are needed. Here we report a simple catechol modified protocol for preparing a novel catechol-chitosan (CCS-iron oxide nanoparticles (IONPs composites carrying adhesive moieties with strong surface affinity. The ω-transaminase (ω-TA was immobilized onto this magnetic composite via nucleophilic reactions between catechol and ω-TA. Under optimal conditions, 87.5% of the available ω-TA was immobilized on the composite, yielding an enzyme loading capacity as high as 681.7 mg/g. Furthermore, the valuation of enzyme activity showed that ω-TA immobilized on CCS-IONPs displayed enhanced pH and thermal stability compared to free enzyme. Importantly, the immobilized ω-TA retained more than 50% of its initial activity after 15 repeated reaction cycles using magnetic separation and 61.5% of its initial activity after storage at 4°C in phosphate buffered saline (PBS for 15 days. The results suggested that such adhesive magnetic composites may provide an improved platform technology for bio-macromolecules immobilized.

  7. Natural impacted freshwaters: in situ use of alginate immobilized algae to the assessment of algal response.

    Science.gov (United States)

    Corrêa, A X R; Tamanaha, M S; Horita, C O; Radetski, M R; Corrêa, R; Radetski, C M

    2009-05-01

    The objective of this study was to investigate the feasibility of an in situ phytotoxicity test using alginate-immobilized algae for 60 days, in the assessment of water quality in an impacted small peri-urban stream. After laboratory optimization of algae immobilization/de-immobilization processes, the performance of immobilized/de-immobilized algae was compared to the performance of free algae in terms of specific algal growth and sensitivity. This was done by comparing 72 h EC50 values obtained with zinc and the pesticides clomazone and carbofuran. The results showed a similar performance, which allow us to conclude that immobilization for 60 days do not cause any significant alteration in algae physiology. In the field, immobilized algae were exposed at different times (2, 4 and 7 days) to water samples in both disturbed and undisturbed sites. Both laboratory and field experiments indicated that alginate-immobilized algae for 60 days were sufficiently sensitive for use in the in situ assessment of water quality.

  8. Acetylcholinesterase immobilization and characterization, and comparison of the activity of the porous silicon-immobilized enzyme with its free counterpart.

    Science.gov (United States)

    Saleem, Muhammad; Rafiq, Muhammad; Seo, Sung-Yum; Lee, Ki Hwan

    2016-02-02

    A successful prescription is presented for acetylcholinesterase physically adsorbed on to a mesoporous silicon surface, with a promising hydrolytic response towards acetylthiocholine iodide. The catalytic behaviour of the immobilized enzyme was assessed by spectrophotometric bioassay using neostigmine methyl sulfate as a standard acetycholinesterase inhibitor. The surface modification was studied through field emission SEM, Fourier transform IR spectroscopy, energy-dispersive X-ray spectroscopy, cathode luminescence and X-ray photoelectron spectroscopy analysis, photoluminescence measurement and spectrophotometric bioassay. The porous silicon-immobilized enzyme not only yielded greater enzyme stability, but also significantly improved the native photoluminescence at room temperature of the bare porous silicon architecture. The results indicated the promising catalytic behaviour of immobilized enzyme compared with that of its free counterpart, with a greater stability, and that it aided reusability and easy separation from the reaction mixture. The porous silicon-immobilized enzyme was found to retain 50% of its activity, promising thermal stability up to 90°C, reusability for up to three cycles, pH stability over a broad pH of 4-9 and a shelf-life of 44 days, with an optimal hydrolytic response towards acetylthiocholine iodide at variable drug concentrations. On the basis of these findings, it was believed that the porous silicon-immobilized enzyme could be exploited as a reusable biocatalyst and for screening of acetylcholinesterase inhibitors from crude plant extracts and synthesized organic compounds. Moreover, the immobilized enzyme could offer a great deal as a viable biocatalyst in bioprocessing for the chemical and pharmaceutical industries, and bioremediation to enhance productivity and robustness.

  9. Tunable control of antibody immobilization using electric field.

    Science.gov (United States)

    Emaminejad, Sam; Javanmard, Mehdi; Gupta, Chaitanya; Chang, Shuai; Davis, Ronald W; Howe, Roger T

    2015-02-17

    The controlled immobilization of proteins on solid-state surfaces can play an important role in enhancing the sensitivity of both affinity-based biosensors and probe-free sensing platforms. Typical methods of controlling the orientation of probe proteins on a sensor surface involve surface chemistry-based techniques. Here, we present a method of tunably controlling the immobilization of proteins on a solid-state surface using electric field. We study the ability to orient molecules by immobilizing IgG molecules in microchannels while applying lateral fields. We use atomic force microscopy to both qualitatively and quantitatively study the orientation of antibodies on glass surfaces. We apply this ability for controlled orientation to enhance the performance of affinity-based assays. As a proof of concept, we use fluorescence detection to indirectly verify the modulation of the orientation of proteins bound to the surface. We studied the interaction of fluorescently tagged anti-IgG with surface immobilized IgG controlled by electric field. Our study demonstrates that the use of electric field can result in more than 100% enhancement in signal-to-noise ratio compared with normal physical adsorption.

  10. Covalent immobilization of lipase from Candida rugosa on Eupergit®

    Directory of Open Access Journals (Sweden)

    Bezbradica Dejan I.

    2005-01-01

    Full Text Available An approach is presented for the stable covalent immobilization of Upase from Candida rugosa on Eupergit® with a high retention of hydrolytic activity. It comprises covalent bonding via lipase carbohydrate moiety previously modified by periodate oxidation, allowing a reduction in the involvement of the enzyme functional groups that are probably important in the catalytic mechanism. The hydrolytic activities of the lipase immobilized on Eupergif1 by two conventional methods (via oxirane group and via glutaralde-hyde and with periodate method were compared. Results of lipase assays suggest that periodate method is superior for lipase immobilization on Eupergit® among methods applied in this study with respect to both, yield of immobilization and hydrolytic activity of the immobilized enzyme.

  11. The effect of immobilization stress on the pharmacokinetics of omeprazole in rats.

    Directory of Open Access Journals (Sweden)

    Watanabe K

    2002-02-01

    Full Text Available The effects of immobilization stress on the pharmacokinetics of omeprazole were studied in rats. The immobilization stress for 30 or 60 min immediately after oral administration of the drug caused an increase in the time to reach the maximum concentration. However, such stress did not alter the area under the plasma concentration-time curve (AUC. When administered intravenously, the half-life during the elimination phase was significantly prolonged by 30 min of immobilization stress, but the AUC value remained unchanged. The intestinal propulsive activity was significantly decreased by immobilization stress. These findings suggest that immobilization stress reduces gastrointestinal motility. A resulting delay during the absorption phase of omeprazole occurs, although the degree of influence on overall pharmacokinetics is relatively insignificant.

  12. Polystyrene Attached Pt(IV)–Azomethine, Synthesis and Immobilization of Glucose Oxidase Enzyme

    Science.gov (United States)

    Sarı, Nurşen; Antepli, Esin; Nartop, Dilek; Yetim, Nurdan Kurnaz

    2012-01-01

    Modified polystyrene with Pt(IV)–azomethine (APS–Sch–Pt) was synthesized by means of condensation and demonstrated to be a promising enzyme support by studying the enzymatic properties of glucose oxidase enzyme (GOx) immobilized on it. The characteristics of the immobilized glucose oxidase (APS–Sch–Pt–GOx) enzyme showed two optimum pH values that were pH = 4.0 and pH = 7. The insertion of stable Pt(IV)–azomethine spacers between the polystyrene backbone and the immobilized GOx, (APS–Sch–Pt–GOx), increases the enzymes’ activity and improves their affinity towards the substrate even at pH = 4. The influence of temperature, reusability and storage capacity on the free and immobilized glucose oxidase enzyme was investigated. The storage stability of the immobilized glucose oxidase was shown to be eleven months in dry conditions at +4 °C. PMID:23109888

  13. Covalent Immobilization of β-Glucosidase on Magnetic Particles for Lignocellulose Hydrolysis

    DEFF Research Database (Denmark)

    Alftrén, Johan; Hobley, Timothy John

    2013-01-01

    β-Glucosidase hydrolyzes cellobiose to glucose and is an important enzyme in the consortium used for hydrolysis of cellulosic and lignocellulosic feedstocks. In the present work, β-glucosidase was covalently immobilized on non-porous magnetic particles to enable re-use of the enzyme. It was found....... The performance and recyclability of immobilized β-glucosidase on more complex substrate (pretreated spruce) was also studied. It was shown that adding immobilized β-glucosidase (16 U/g dry matter) to free cellulases (8 FPU/g dry matter) increased the hydrolysis yield of pretreated spruce from ca. 44 % to ca. 65...... %. In addition, it was possible to re-use the immobilized β-glucosidase in the spruce and retain activity for at least four cycles. The immobilized enzyme thus shows promise for lignocellulose hydrolysis....

  14. Stabilization of {alpha}-amylase by using anionic surfactant during the immobilization process

    Energy Technology Data Exchange (ETDEWEB)

    El-Batal, A.I. [National Center for Radiation Research and Technology, P.O. Box 29, Nasr City, Cairo (Egypt); Atia, K.S. [Nuclear Research Center, Radioisotopes Applications Division, Abo-Zable, P.O. Box 13759, Cairo (Egypt)]. E-mail: ks_atia@yahoo.com; Eid, M. [National Center for Radiation Research and Technology, P.O. Box 29, Nasr City, Cairo (Egypt)

    2005-10-01

    This work describes the entrapment of {alpha}-amylase into butylacrylate-acrylic acid copolymer (BuA/AAc) using {gamma} irradiation. The effect of an anionic surfactant (AOT), the reuse efficiency, and kinetic behavior of immobilized {alpha}-amylase were studied. Covering of {alpha}-amylase with bis-(2-ethylhexyl)sulfosuccinate sodium salt (AOT) made the enzyme more stable than the uncovered form. The hydrolytic activity of the pre-coated immobilized {alpha}-amylase was increased below the critical micelle concentration (cmc) (10mmol/L). The results showed an increase in the relative activity with increase in the degree of hydration. The pre-coated immobilized {alpha}-amylase showed a higher k{sub cat}/K{sub m} and lower activation energy compared to the free and uncoated-immobilized preparation, respectively. The results suggest that the immobilization of {alpha}-amylase is a potentially useful approach for commercial starch hydrolysis in two-phase systems.

  15. Immobilization of Streptomyces thermotolerans 11432 on polyurethane foam to improve production of acetylisovaleryltylosin.

    Science.gov (United States)

    Zhu, Hongji; Wang, Weihua; Liu, Jiaheng; Caiyin, Qinggele; Qiao, Jianjun

    2015-01-01

    In this study, polyurethane foam (PUF) was chemically treated to immobilize Streptomyces thermotolerans 11432 for semi-continuous production of acetylisovaleryltylosin (AIV). Based on experimental results, positive cross-linked PUF (PCPUF) was selected as the most effective carrier according to immobilized cell mass. The effect of adsorption time on immobilized mass was investigated. AIV concentration (33.54 mg/l) in batch fermentations with immobilized cells was higher than with free cells (20.34 mg/l). In repeated batch fermentations with immobilized S. thermotolerans 11432 using PCPUF cubes, high AIV concentrations and conversion rates were attained, ranging from 25.56 to 34.37 mg/l and 79.93 to 86.31 %, respectively. Significantly, this method provides a feasible strategy for efficient AIV production and offers the potential for large-scale production.

  16. Glutathione transferases immobilized on nanoporous alumina: flow system kinetics, screening, and stability.

    Science.gov (United States)

    Kjellander, Marcus; Mazari, Aslam M A; Boman, Mats; Mannervik, Bengt; Johansson, Gunnar

    2014-02-01

    The previously uncharacterized Drosophila melanogaster Epsilon-class glutathione transferases E6 and E7 were immobilized on nanoporous alumina. The nanoporous anodized alumina membranes were derivatized with 3-aminopropyl-triethoxysilane, and the amino groups were activated with carbonyldiimidazole to allow coupling of the enzymes via ε-amino groups. Kinetic analyses of the immobilized enzymes were carried out in a circulating flow system using CDNB (1-chloro-2,4-dinitrobenzene) as substrate, followed by specificity screening with alternative substrates. A good correlation was observed between the substrate screening data for immobilized enzyme and corresponding data for the enzyme in solution. A limited kinetic study was also carried out on immobilized human GST S1-1 (also known as hematopoietic prostaglandin D synthase). The stability of the immobilized enzymes was virtually identical to that of enzymes in solution, and no leakage of enzyme from the matrix could be observed.

  17. Cellulases immobilization on chitosan-coated magnetic nanoparticles: application for Agave Atrovirens lignocellulosic biomass hydrolysis.

    Science.gov (United States)

    Sánchez-Ramírez, Jaquelina; Martínez-Hernández, José L; Segura-Ceniceros, Patricia; López, Guillermo; Saade, Hened; Medina-Morales, Miguel A; Ramos-González, Rodolfo; Aguilar, Cristóbal N; Ilyina, Anna

    2017-01-01

    In the present study, Trichoderma reesei cellulase was covalently immobilized on chitosan-coated magnetic nanoparticles using glutaraldehyde as a coupling agent. The average diameter of magnetic nanoparticles before and after enzyme immobilization was about 8 and 10 nm, respectively. The immobilized enzyme retained about 37 % of its initial activity, and also showed better thermal and storage stability than free enzyme. Immobilized cellulase retained about 80 % of its activity after 15 cycles of carboxymethylcellulose hydrolysis and was easily separated with the application of an external magnetic field. However, in this reaction, K m was increased eight times. The immobilized enzyme was able to hydrolyze lignocellulosic material from Agave atrovirens leaves with yield close to the amount detected with free enzyme and it was re-used in vegetal material conversion up to four cycles with 50 % of activity decrease. This provides an opportunity to reduce the enzyme consumption during lignocellulosic material saccharification for bioethanol production.

  18. Pineapple stem bromelain immobilized on different supports: catalytic properties in model wine.

    Science.gov (United States)

    Ilaria, Benucci; Marco, Esti; Katia, Liburdi; Maria Vittoria, Garzillo Anna

    2012-01-01

    Bromelain from pineapple stem has been covalently immobilized on different supports to select the more efficient biocatalyst that should be applied toward unstable proteins in real white wine. In this preliminary study, catalytic properties of different immobilized bromelain forms were compared under wine-like conditions, against a synthetic substrate (Bz-Phe-Val-Arg-pNA).Covalent immobilization affected protease kinetic properties, even if all immobilized forms presented both a better substrate affinity and higher half-life (with the exception of a few procedures) with respect to the free enzyme. Stem bromelain was successfully immobilized on chitosan beads without glutaraldehyde thus yielding a food-safe and promising biocatalyst for unstable real wine future application.

  19. Stabilization of α-amylase by using anionic surfactant during the immobilization process

    Science.gov (United States)

    El-Batal, A. I.; Atia, K. S.; Eid, M.

    2005-10-01

    This work describes the entrapment of α-amylase into butylacrylate-acrylic acid copolymer (BuA/AAc) using γ irradiation. The effect of an anionic surfactant (AOT), the reuse efficiency, and kinetic behavior of immobilized α-amylase were studied. Covering of α-amylase with bis-(2-ethylhexyl)sulfosuccinate sodium salt (AOT) made the enzyme more stable than the uncovered form. The hydrolytic activity of the pre-coated immobilized α-amylase was increased below the critical micelle concentration (cmc) (10 mmol/L). The results showed an increase in the relative activity with increase in the degree of hydration. The pre-coated immobilized α-amylase showed a higher k/K and lower activation energy compared to the free and uncoated-immobilized preparation, respectively. The results suggest that the immobilization of α-amylase is a potentially useful approach for commercial starch hydrolysis in two-phase systems.

  20. Magnetic resonance imaging for radiotherapy planning of brain cancer patients using immobilization and surface coils

    Energy Technology Data Exchange (ETDEWEB)

    Hanvey, S; Glegg, M; Foster, J [Department of Clinical Physics and Bioengineering, Beatson West of Scotland Cancer Centre, 1053 Great Western Road, Glasgow G12 0YN (United Kingdom)], E-mail: scott.hanvey@ggc.scot.nhs.uk

    2009-09-21

    This study investigated the compatibility of a head and neck immobilization device with magnetic resonance imaging (MRI). The immobilization device is used to position a patient in the same way as when receiving a computed tomography (CT) scan for radiotherapy planning and radiation treatment. The advantage of using immobilization in MR is improved accuracy in CT/MR image registration enabling greater confidence in the delineation of structures. The main practical difficulty in using an immobilization device in MRI is that physical constraints make their use incompatible with head imaging coils. Within this paper we describe a method for MR imaging of the brain which allows the use of head and neck immobilization devices. By a series of image quality tests we obtained the same or better image quality as a multi-channel head coil.

  1. Magnetic resonance imaging for radiotherapy planning of brain cancer patients using immobilization and surface coils

    Science.gov (United States)

    Hanvey, S.; Glegg, M.; Foster, J.

    2009-09-01

    This study investigated the compatibility of a head and neck immobilization device with magnetic resonance imaging (MRI). The immobilization device is used to position a patient in the same way as when receiving a computed tomography (CT) scan for radiotherapy planning and radiation treatment. The advantage of using immobilization in MR is improved accuracy in CT/MR image registration enabling greater confidence in the delineation of structures. The main practical difficulty in using an immobilization device in MRI is that physical constraints make their use incompatible with head imaging coils. Within this paper we describe a method for MR imaging of the brain which allows the use of head and neck immobilization devices. By a series of image quality tests we obtained the same or better image quality as a multi-channel head coil.

  2. Cellulose aerogel regenerated from ionic liquid solution for immobilized metal affinity adsorption.

    Science.gov (United States)

    Oshima, Tatsuya; Sakamoto, Toshihiko; Ohe, Kaoru; Baba, Yoshinari

    2014-03-15

    Surface morphology of cellulosic adsorbents is expected to influence the adsorption behavior of biomacromolecules. In the present study, cellulose aerogel regenerated from ionic liquid solution was prepared for use as a polymer support for protein adsorption. Iminodiacetic acid groups were introduced to the aerogel for immobilized metal affinity adsorption of proteins. A Cu(II)-immobilized iminodiacetic acid cellulose aerogel (Cu(II)-IDA-CA), which has a large specific surface area, showed a higher adsorption capacity than Cu(II)-immobilized iminodiacetic acid bacterial cellulose (Cu(II)-IDA-BC) and Cu(II)-immobilized iminodiacetic acid plant cellulose (Cu(II)-IDA-PC). In contrast, the Cu(II)-immobilized cellulosic adsorbents showed similar adsorption capacities for smaller amino acid and peptides. The results show that cellulose aerogels are useful as polymer supports with high protein adsorption capacities.

  3. Chitin hydrolysis assisted by cell wall degrading enzymes immobilized of Thichoderma asperellum on totally cinnamoylated D-sorbitol beads

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, Kátia F., E-mail: katia@icb.ufg.br [Departamento de Bioquímica e Biologia Molecular, Instituo de Ciências Biológicas, Universidade Federal de Goiás, Cx. Postal 131, 74001-970 Goiânia, GO (Brazil); Grupo de Química de Carbohidratos y Biotecnología de Alimentos (QCBA), Departamento de Química Orgánica, Facultad de Química, Universidad de Murcia, E-30100 Espinardo, Murcia (Spain); Cortijo-Triviño, David [Grupo de Química de Carbohidratos y Biotecnología de Alimentos (QCBA), Departamento de Química Orgánica, Facultad de Química, Universidad de Murcia, E-30100 Espinardo, Murcia (Spain); Batista, Karla A.; Ulhoa, Cirano J. [Departamento de Bioquímica e Biologia Molecular, Instituo de Ciências Biológicas, Universidade Federal de Goiás, Cx. Postal 131, 74001-970 Goiânia, GO (Brazil); García-Ruiz, Pedro A. [Grupo de Química de Carbohidratos y Biotecnología de Alimentos (QCBA), Departamento de Química Orgánica, Facultad de Química, Universidad de Murcia, E-30100 Espinardo, Murcia (Spain)

    2013-07-01

    In this study, cell wall degrading enzymes produced by Thrichoderma asperellum (TCWDE) were immobilized on totally cinnamoylated D-sorbitol (TCNSO) beads and used for chitin hydrolysis. In order to optimize immobilization efficiency, the reaction time was varied from 2 to 12 h and reactions were conducted in the presence or absence of Na{sub 2}SO{sub 4}. Immobilized enzymes were analysed concerning to thermal and operational stability. Immobilization in presence of Na{sub 2}SO{sub 4} was 54% more efficient than immobilization in absence of salt. After optimization, 32% of the total enzyme offered was immobilized, with 100% of bounding efficiency, measured as the relation between protein and enzyme immobilized. Free and TCNSO–TCWDE presented very similar kinetics with maximum hydrolysis reached at 90 min of reaction. Thermal stability of both free and TCNSO–TCWDE was similar, with losses in activity after 55 °C. Moreover, free and TCNSO–TCWDE retained 100% activity after 3 h incubation at 55 °C. TCNSO–TCWDE were used in a bath-wise reactor during 14 cycles, producing 1825 μg of N-acetylglucosamine (NAG) maintaining 83% of initial activity. - Highlights: • TCWDE immobilized on TCNSO, a support with highly hydrophobic character • New immobilization strategy for immobilization on a hydrophobic support • TCNSO–TCWDE were retained during washes and during incubation at 55 °C for 3 h.

  4. Effect of temperature and mixing speed on immobilization of crude enzyme from Aspergillus niger on chitosan for hydrolyzing cellulose

    Science.gov (United States)

    Hamzah, Afan; Gek Ela Kumala, P.; Ramadhani, Dwi; Maziyah, Nurul; Rahmah, Laila Nur; Soeprijanto, Widjaja, Arief

    2017-05-01

    Conversion of cellulose into reducing sugar through enzymatic hydrolysis has advantageous because it produces greater product yield, higher selectivity, require less energy, more moderate operating conditions and environment friendly. However, the nature of the enzyme that is difficult to separate and its expensive price become an obstacle. These obstacles can be overcome by immobilizing the enzyme on chitosan material so that the enzyme can be reused. Chitosan is chosen because it is cheap, inert, hydrophilic, and biocompatible. In this research, we use covalent attachment and combination between covalent attachment and cross-linking method for immobilizing crude enzyme. This research was focusing in study of Effect of temperature and mixing speed on Immobilization Enzyme From Aspergillus Niger on Chitosan For Hydrolyzing both soluble (Carboxymethylcellulose) and insoluble Cellulose (coconut husk). This Research was carried out by three main step. First, coconut husk was pre-treated mechanically and chemically, Second, Crude enzyme from Aspergillus niger strain was immobilized on chitosan in various immobilization condition. At last, the pre-treated coconut husk and Carboxymetylcellulose (CMC) were hydrolyzed by immobilized cellulose on chitosan for reducing sugar production. The result revealed that the most reducing sugar produced by immobilized enzyme on chitosan+GDA with immobilization condition at 30 °C and 125 rpm. Enzyme immobilized on chitosan cross-linked with GDA produced more reducing sugar from preteated coconut husk than enzyme immobilized on chitosan.

  5. Effect of low-level helium-neon laser therapy on histological and ultrastructural features of immobilized rabbit articular cartilage.

    Science.gov (United States)

    Bayat, Mohammad; Ansari, Enayatallah; Gholami, Narges; Bayat, Aghdas

    2007-05-25

    The present study investigates whether low-level helium-neon laser therapy can increase histological parameters of immobilized articular cartilage in rabbits or not. Twenty five rabbits were divided into three groups: the experiment group, which received low-level helium-neon laser therapy with 13J/cm(2) three times a week after immobilization of their right knees; the control group which did not receive laser therapy after immobilization of their knees; and the normal group which received neither immobilization nor laser therapy. Histological and electron microscopic examinations were performed at 4 and 7 weeks after immobilization. Depth of the chondrocyte filopodia in four-week immobilized experiment group, and depth of articular cartilage in seven-week immobilized experiment group were significantly higher than those of relevant control groups (exact Fisher test, p=0.001; student's t-test, p=0.031, respectively). The surfaces of articular cartilages of the experiment group were relatively smooth, while those of the control group were unsmooth. It is therefore concluded that low-level helium-neon laser therapy had significantly increased the depth of the chondrocyte filopodia in four-week immobilized femoral articular cartilage and the depth of articular cartilage in seven-week immobilized knee in comparison with control immobilized articular cartilage.

  6. Covalent attachment of cholesterol oxidase and horseradish peroxidase on perlite through silanization: activity, stability and co-immobilization.

    Science.gov (United States)

    Torabi, Seyed-Fakhreddin; Khajeh, Khosro; Ghasempur, Salehe; Ghaemi, Nasser; Siadat, Seyed-Omid Ranaei

    2007-08-31

    In the present work, co-immobilization of cholesterol oxidase (COD) and horseradish peroxidase (POD) on perlite surface was attempted. The surface of perlite were activated by 3-aminopropyltriethoxysilane and covalently bonded with COD and POD via glutaraldehyde. Enzymes activities have been assayed by spectrophotometric technique. The stabilities of immobilized COD and POD to pH were higher than those of soluble enzymes and immobilization shifted optimum pH of enzymes to the lower pH. Heat inactivation studies showed improved thermostability of the immobilized COD for more than two times, but immobilized POD was less thermostable than soluble POD. Also activity recovery of immobilized COD was about 50% since for immobilized POD was 11%. The K(m) of immobilized enzymes was found slightly lower than that of soluble enzymes. Immobilized COD showed inhibition in its activity at high cholesterol concentration which was not reported for soluble COD before. Co-immobilized enzymes retained 65% of its initial activity after 20 consecutive reactor batch cycles.

  7. Technetium Immobilization Forms Literature Survey

    Energy Technology Data Exchange (ETDEWEB)

    Westsik, Joseph H.; Cantrell, Kirk J.; Serne, R. Jeffrey; Qafoku, Nikolla

    2014-05-01

    Of the many radionuclides and contaminants in the tank wastes stored at the Hanford site, technetium-99 (99Tc) is one of the most challenging to effectively immobilize in a waste form for ultimate disposal. Within the Hanford Tank Waste Treatment and Immobilization Plant (WTP), the Tc will partition between both the high-level waste (HLW) and low-activity waste (LAW) fractions of the tank waste. The HLW fraction will be converted to a glass waste form in the HLW vitrification facility and the LAW fraction will be converted to another glass waste form in the LAW vitrification facility. In both vitrification facilities, the Tc is incorporated into the glass waste form but a significant fraction of the Tc volatilizes at the high glass-melting temperatures and is captured in the off-gas treatment systems at both facilities. The aqueous off-gas condensate solution containing the volatilized Tc is recycled and is added to the LAW glass melter feed. This recycle process is effective in increasing the loading of Tc in the LAW glass but it also disproportionally increases the sulfur and halides in the LAW melter feed which increases both the amount of LAW glass and either the duration of the LAW vitrification mission or the required supplemental LAW treatment capacity.

  8. Optimization, isotherm, kinetic and thermodynamic studies of Pb(II) ions adsorption onto N-maleated chitosan-immobilized TiO₂ nanoparticles from aqueous media.

    Science.gov (United States)

    Shaker, Medhat A; Yakout, Amr A

    2016-02-05

    Chitosan, CS was chemically engineered by maleic anhydride via simple protocol to produce N-maleated chitosan, MCS which immobilized on anatase TiO2 to synthesize novel eco-friendly nanosorbent (51±3.8 nm), MCS@TiO2 for cost-effective and efficient removal of Pb(II) ions from aqueous media. The chemical structure, surface properties and morphology of MCS@TiO2 were recognized by FTIR, (1)H NMR, XRD, TEM, DLS and zeta-potential techniques. The relations between %removal of Pb(II) and different analytical parameters such as solution acidity (pH), MCS@TiO2 dosage, time of contact and initial Pb(II) concentration were optimized using response surface methodology (RSM) and Box-Behnken design (BBD) statistical procedures. The fitting of the experimental data to four different isotherm models at optimized conditions was carried out by various statistical treatments including the correlation coefficient (r), coefficient of determination (r(2)) and non-linear Chi-square (χ(2)) test analyses which all confirm the suitability of Langmuir model to explain the adsorption isotherm data. Also, statistics predicted that the pseudo-second-order model is the optimum kinetic model among four applied kinetic models to closely describe the rate equation of the adsorption process. Thermodynamics viewed the adsorption as endothermic and feasible physical process. EDTA could release the sorbed Pb(II) ions from MCS@TiO2 with a recovery above 92% after three sorption-desorption cycles. The novel synthesized nanosorbent is evidenced to be an excellent solid phase extractor for Pb(II) ions from wastewaters.

  9. Enhancement of photocatalytic degradation of dimethyl phthalate with nano-TiO{sub 2} immobilized onto hydrophobic layered double hydroxides: A mechanism study

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Zhujian [College of Environmental Science and Engineering, South China University of Technology, Guangzhou 510006 (China); The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006 (China); Wu, Pingxiao, E-mail: pppxwu@scut.edu.cn [College of Environmental Science and Engineering, South China University of Technology, Guangzhou 510006 (China); The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006 (China); The Key Laboratory of Environmental Protection and Eco-Remediation of Guangdong Regular Higher Education Institutions (China); Lu, Yonghong; Wang, Xiaorong; Zhu, Nengwu [College of Environmental Science and Engineering, South China University of Technology, Guangzhou 510006 (China); The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006 (China); Dang, Zhi [College of Environmental Science and Engineering, South China University of Technology, Guangzhou 510006 (China); The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006 (China); The Key Laboratory of Environmental Protection and Eco-Remediation of Guangdong Regular Higher Education Institutions (China)

    2013-02-15

    Highlights: ► The reconstructed organic LDHs are consisted of the interconnecting nano-flakes. ► It is confirmed that organic LDHs/TiO{sub 2} composites are combined together by chemical bonds. ► The organic LDHs with flaky structure effectively enrich DPM onto the composite. ► The abundant external hydroxyl groups of organic LDHs promote the production of ·OH. ► TiO{sub 2} immobilized onto organic LDHs greatly enhances the photodegradation of DMP. -- Abstract: The organic layered double hydroxides (LHDs)/TiO{sub 2} composites with various mass ratios were prepared by the reconstruction of mixed metal oxides to photodegrade dimethyl phthalate (DMP). The physicochemical properties of the obtained products were analyzed by X-ray diffraction (XRD) spectra, X-ray photoelectron spectra (XPS), UV–vis diffuse reflectance spectroscope and scanning electron microscope (SEM). The results showed that the TiO{sub 2} particles and the organic LDHs were combined together through chemical bonds, and TiO{sub 2} particles were well distributed on the surface of the interconnecting organic LDHs nano-flakes. According to the experimental results of adsorptive and photodegradation of DMP, the organic LDHs with flaky structure could effectively adsorb the DMP molecules and the adsorption isotherm by the composites modeled well with the Langmuir equation. The enrichment of DMP onto the composites and the external hydroxyl groups of the composites produce a synergistic effect leading to greatly enhance the rate of DMP photocatalytic degradation by the obtained composites.

  10. Evaluation of meat and bone meal combustion residue as lead immobilizing material for in situ remediation of polluted aqueous solutions and soils: "chemical and ecotoxicological studies".

    Science.gov (United States)

    Deydier, E; Guilet, R; Cren, S; Pereas, V; Mouchet, F; Gauthier, L

    2007-07-19

    As a result of bovine spongiform encephalopathy (BSE) crisis, meat and bone meal (MBM) production can no longer be used to feed cattle and must be safely disposed of or transformed. MBM specific incineration remains an alternative that could offer the opportunity to achieve both thermal valorization and solid waste recovery as ashes are calcium phosphate-rich material. The aim of this work is to evaluate ashes efficiency for in situ remediation of lead-contaminated aqueous solutions and soils, and to assess the bioavailability of lead using two biological models, amphibian Xenopus laevis larvae and Nicotiana tabaccum tobacco plant. With the amphibian model, no toxic or genotoxic effects of ashes are observed with concentrations from 0.1 to 5 g of ashes/L. If toxic and genotoxic effects of lead appear at concentration higher than 1 mg Pb/L (1 ppm), addition of only 100 mg of ashes/L neutralizes lead toxicity even with lead concentration up to 10 ppm. Chemical investigations (kinetics and X-ray diffraction (XRD) analysis) reveals that lead is quickly immobilized as pyromorphite [Pb10(PO4)6(OH)2] and lead carbonate dihydrate [PbCO(3).2H2O]. Tobacco experiments are realized on contaminated soils with 50, 100, 2000 and 10000 ppm of lead with and without ashes amendment (35.3g ashes/kg of soil). Tobacco measurements show that plant elongation is bigger in an ashes-amended soil contaminated with 10000 ppm of lead than on the reference soil alone. Tobacco model points out that ashes present two beneficial actions as they do not only neutralize lead toxicity but also act as a fertilizer.

  11. Engineering aspects of nitrification with immobilized cells.

    NARCIS (Netherlands)

    Hunik, J.H.

    1993-01-01

    Several aspects of a nitrification process with artificially immobilized cells in an airlift loop reactor have been investigated and are described in this thesis. In chapter 1 an overview of immobilization methods, suitable reactors, modelling, small-scaleapplications and scale-up strategy is given.

  12. Silica-Immobilized Enzyme Reactors (Postprint)

    Science.gov (United States)

    2007-09-01

    Non-solubilized UDPGT from rat liver microsomes was covalently immobilized to a func- tionalized silica support by Schiff base chemistry and a number...activity within a day. GADPH isolated from rabbit was covalently immobilized to a wide-pore silica support by glutaraldehyde activation and Schiff - base chemistry

  13. 负载型TiO2光催化剂的制备及光催化活性研究%Preparation of The Immobilized TiO2 Activator and the Experimental Study on Its Photo Activity

    Institute of Scientific and Technical Information of China (English)

    夏怡; 李亚峰; 赵艳红; 王建

    2011-01-01

    This paper aims to study the effects of immobilized TiO2 photo activator dealing with organic dyestuff, and determine the technical processes of removing red dye X-3 B wastewater.With C2 H5 OH as solvent and Ti( OBu)4 as precursor,the wide hole silica gel as the carrier,we use the Sol-Gel technique to make the immobilized TiO2 activator.With the 20 W ( 253.7 nm) ultraviolet radiation antiseptic light as the lamphouse, the photo catalytic & oxidation reactor which was made and designed by ourselves, the photo catalytic & oxidation experiment was carried out.Through the experiment, this paper analyzed the effects of factors on photo catalytic degradation, such as, the doses of C2H5OH and nitric acid, film coating times, and calcination temperature.The experimental results indicated that in the condition of 5 times of film coating and the 450℃ heating temperature, the immobilized TiO2 activator can degrade the dyeing wastewater effectively.The conclusion is that the immobilized TiO2 activator has better photo catalytic activity, and well conquers the disadvantages of the pulverous TiO2 which is easy to loss and hard to recover.%目的 研究负载型TiO2光催化剂对有机染料的处理效果,确定其去除活性艳红X-3B废水的工艺条件.方法 以钛酸正四丁酯为前躯体,无水乙醇为溶剂、以粒径2~3 mm粗孔硅胶微球为载体,用溶胶-凝胶法制备负载型TiO2光催化剂.以20W(λ=253.7 nm)紫外线杀菌灯为光源,采用自制反应器进行光催化氧化试验.通过试验研究分析了负载型TiO2光催化剂无水乙醇和硝酸的投加量、镀膜次数、煅烧温度等因素对光催化降解效果的影响.结果 镀膜5次、煅烧温度为450℃制成的催化剂对活性艳红X-3B染料废水有较好的去除效果.当废水初始质量浓度为50 mg/L,调节pH为3左右,催化剂的投加量为10g/L,反应2 h,脱色率96%以上.结论 用溶胶-凝胶法制备负载型TiO2光催化剂具有较好的光催化活

  14. Bioreduction of chromate by immobilized cells of Halomonas sp

    Energy Technology Data Exchange (ETDEWEB)

    Murugavelh, S.; Mohanty, Kaustubha [Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati – 781039, Assam (India)

    2013-07-01

    In this work, the bioreduction of Cr(VI) by immobilized cells of Halomonas sp was reported. Ca alginate, acryl amide and agar were tested as the matrices for immobilization. Ca alginate was found to be the suitable matrix among the different matrices studied. Of the various dosages of inoculum studied 2 g/L was found to be the optimum. Glucose at 1 g L-1 was completely utilized by the immobilized Halomonas sp even in the presence of Cr(VI) at 40 mg L-1. The optimum pH for the bioreduction of Cr(VI) by immobilized Halomonas sp was found to be pH 6. The mechanical strength of the beads plays an essential role in the bioreduction process. Halomonas sp entrapped in a alginate matrix reported a maximum of 98.9 % of reduction for an initial Cr(VI) concentration of 10 mg L-1. The alginate beads can be reused for 3 times with slight drop in the percentage reduction. The presence of other metals decreased the bioreduction percentage.

  15. Leukocyte responses to immobilized patterns of CXCL8.

    Science.gov (United States)

    Girrbach, Maria; Rink, Ina; Ladnorg, Tatjana; Azucena, Carlos; Heißler, Stefan; Haraszti, Tamás; Schepers, Ute; Schmitz, Katja

    2016-06-01

    The attachment of neutrophils to the endothelial surface and their migration towards the site of inflammation following chemokine gradients play an essential role in the innate immune response. Chemokines adhere to glycosaminoglycans on the endothelial surface to be detected by leukocytes and trigger their movement along surface- bound gradients in a process called haptotaxis. In assays to systematically study the response of leukocytes to surface-bound compounds both the spatial arrangement of the compound as well as the mode of immobilization need to be controlled. In this study microcontact printing was employed to create patterns of hydrophobic or functionalized thiols on gold-coated glass slides and CXCL8 was immobilized on the thiol coated areas using three different strategies. Human neutrophils adhered to the CXCL8-coated lines but not to the PEG-coated background. We could show that more cells adhered to CXCL8 adsorbed to hydrophobic octadecanethiol than on CXCL8 covalently bound to amino undecanethiol or CXCL8 specifically bound to immobilized heparin on aminothiol. Likewise general cell activity such as lamellipodia formation and random migration were most pronounced for CXCL8 adsorbed on a hydrophobic surface which may be attributed to the larger amounts of protein immobilized on this type of surface.

  16. Immobilizing Biomolecules Near the Diffraction Limit

    DEFF Research Database (Denmark)

    Skovsen, Esben; Petersen, Maria Teresa Neves; Gennaro, Ane Kold Di

    2009-01-01

    Our group has previously shown that biomolecules containing disulfide bridges in close proximity to aromatic residues can be immobilized, through covalent bonds, onto thiol derivatized surfaces upon UV excitation of the aromatic residue(s). We have also previously shown that our new technology can...... be used to print arrays of biomolecules and to immobilize biomolecules according to any specific pattern on a planar substrates with micrometer scale resolution. In this paper we show that we can immobilize proteins according to diffraction patterns of UV light. We also show that the feature size...... of the immobilized patterns can be as small as the diffraction limit for the excitation light, and that the immobilized patterns correspond to the diffraction pattern used to generate it. The flexibility of this new technology will in principle make it possible to create any pattern of biomolecules onto a substrate...

  17. Immobilized Lactase in the Biochemistry Laboratory

    Science.gov (United States)

    Allison, Matthew J.; Bering, C. Larry

    1998-10-01

    Immobilized enzymes have many practical applications. They may be used in clinical, industrial, and biotechnological laboratories and in many clinical diagnostic kits. For educational purposes, use of immobilized enzymes can easily be taught at the undergraduate or even secondary level. We have developed an immobilized enzyme experiment that combines many practical techniques used in the biochemistry laboratory and fits within a three-hour time frame. In this experiment, lactase from over-the-counter tablets for patients with lactose intolerance is immobilized in polyacrylamide, which is then milled into small beads and placed into a chromatography column. A lactose solution is added to the column and the eluant is assayed using the glucose oxidase assay, available as a kit. We have determined the optimal conditions to give the greatest turnover of lactose while allowing the immobilized enzymes to be active for long periods at room temperature.

  18. Immobilization of whole cells using polymeric coatings

    Energy Technology Data Exchange (ETDEWEB)

    Lawton, C.W.; Klei, H.E.; Sunstrom, D.V.; Voronka, P.J.; Scott, C.D. (ed.)

    1986-01-01

    A cell immobilization procedure was developed using latex coatings on solid particles. The method's widespread applicability has been demonstrated by successfully immobilizing Saccharomyces cerevisiae (ethanol production), Bacillus subtilis (tryptophan production). Penicillium chrysogenum (penicillin G production), and Escherichia coli (aspartic acid production). In contrast to other immobilization methods, this procedure produces a pellicular particle that is porous, allowing rapid substrate and gas transfer, has a hard core to avoid compression in large beds, and is dense to allow use in fluidized beds. The immobilization procedure was optimized with S. cerevisiae. Kinetic constants obtained were used to calculate effectiveness factors to show that there was minimal intraparticle diffusion resistance. Reactors utilizing the optimized particles were run for 300 hours to evaluate immobilized particle half-life which was 250 hours.

  19. Biodegradation of 2,6-ditert-butylphenol by immobilized microorganism strains

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    2,6-Ditert-butylphenol (2,6-DTBP) is a major organic contaminant presenting in acrylic fiber manufacturing wastewaters.This compound is of high bio-resistance due to its complex structure which consists of one phenol group and two highly branched tert-butyl groups. This research attempted to improve the biodegradation efficiency of 2,6-DTBP through various strain immobilization methods. The stratified immobilization can settle oxygen transmission in the single microorganism immobilization, and can realize two-process reaction in the single device by choosing two symbiotic microorganisms. Two effective strains, named F-l-4 and F-3-4,which were screened out in our previous work, were used to degrade 2,6-DTBP after being immobilized in calcium alginate gel.Results indicate that the substrate removal efficiency of various immobilization methods follows the order: stratified > single F-3-4 >mixed ≈single F-1-4. The immobilized biodegradation capacity was higher than the free one. After an incubation time of 12 d, 91%of 2,6-DTBP could be degraded by the stratified immobilization method, compared to 79% achieved by the mixed immobilization method with an initial 2,6-DTBP concentration of 100 mg/L. The stratified immobilization satisfies the oxygen demand nature of the aerobic F-3-4 and the facultative F-1-4, thus yielding the highest degradation efficiency. Both the outer layer strain F-3-4 and the inner layer strain F-1-4 can grow actively on the substrate of 2,6-DTBP, as illustrated by SEM images. This study shows that the highly bio-refractory compound, 2,6-DTBP, can be effectively degraded using appropriately immobilized microorganism strains.

  20. An orientation analysis method for protein immobilized on quantum dot particles

    Energy Technology Data Exchange (ETDEWEB)

    Aoyagi, Satoka, E-mail: aoyagi@life.shimane-u.ac.jp [Faculty of Life and Environmental Science, Shimane University, 1060 Matsue-shi, Shimane 690-8504 (Japan); Inoue, Masae [Toyota Central R and D Labs., Inc., Nagakute, Aichi 480-1192 (Japan)

    2009-11-30

    The evaluation of orientation of biomolecules immobilized on nanodevices is crucial for the development of high performance devices. Such analysis requires ultra high sensitivity so as to be able to detect less than one molecular layer on a device. Time-of-flight secondary ion mass spectrometry (TOF-SIMS) has sufficient sensitivity to evaluate the uppermost surface structure of a single molecular layer. The objective of this study is to develop an orientation analysis method for proteins immobilized on nanomaterials such as quantum dot particles, and to evaluate the orientation of streptavidin immobilized on quantum dot particles by means of TOF-SIMS. In order to detect fragment ions specific to the protein surface, a monoatomic primary ion source (Ga{sup +}) and a cluster ion source (Au{sub 3}{sup +}) were employed. Streptavidin-immobilized quantum dot particles were immobilized on aminosilanized ITO glass plates at amino groups by covalent bonding. The reference samples streptavidin directly immobilized on ITO plates were also prepared. All samples were dried with a freeze dryer before TOF-SIMS measurement. The positive secondary ion spectra of each sample were obtained using TOF-SIMS with Ga{sup +} and Au{sub 3}{sup +}, respectively, and then they were compared so as to characterize each sample and detect the surface structure of the streptavidin immobilized with the biotin-immobilized quantum dots. The chemical structures of the upper surface of the streptavidin molecules immobilized on the quantum dot particles were evaluated with TOF-SIMS spectra analysis. The indicated surface side of the streptavidin molecules immobilized on the quantum dots includes the biotin binding site.

  1. Selective Protein Immobilization onto Gold Nanoparticles Deposited under Vacuum on a Protein-Repellent Self-Assembled Mono layer

    OpenAIRE

    Peissker, Tobias; Deschaume, Olivier; Rand, Danielle R.; BOYEN, Hans-Gerhard; CONARD, Thierry; Van Bael, Margriet J; Bartic, Carmen

    2013-01-01

    The immobilization of proteins on flat substrates plays an important role for a wide spectrum of applications in the fields of biology, medicine, and biochemistry, among others. An essential prerequisite for the use of proteins (e.g., in biosensors) is the conservation of their biological activity. Losses in activity upon protein immobilization can largely be attributed to a random attachment of the proteins to the surface. In this study, we present an approach for the immobilization of prote...

  2. 1-Step Versus 2-Step Immobilization of Alkaline Phosphatase and Bone Morphogenetic Protein-2 onto Implant Surfaces Using Polydopamine

    OpenAIRE

    Nijhuis, Arnold W.G.; van den Beucken, Jeroen J.J.P.; Boerman, Otto C.; Jansen, John A.; Leeuwenburgh, Sander C.G.

    2013-01-01

    Immobilization of biomolecules onto implant surfaces is highly relevant in many areas of biomaterial research. Recently, a 2-step immobilization procedure was developed for the facile conjugation of biomolecules onto various surfaces using self-polymerization of dopamine into polydopamine. In the current study, a 1-step polydopamine-based approach was applied for alkaline phosphatase (ALP) and bone morphogenetic protein-2 (BMP-2) immobilization, and compared to the conventional 2-step polydop...

  3. Effects of 2 weeks lower limb immobilization and two separate rehabilitation regimens on gastrocnemius muscle protein turnover signaling and normalization genes

    DEFF Research Database (Denmark)

    Nedergaard, Anders; Jespersen, Jakob G; Pingel, Jessica;

    2012-01-01

    ABSTRACT: BACKGROUND: Limb immobilization causes a rapid loss of muscle mass and strength that requires appropriate rehabilitation to ensure restoration of normal function. Whereas the knowledge of muscle mass signaling with immobilization has increased in recent years, the molecular regulation...... in the rehabilitation of immobilization-induced muscle atrophy is only sparsely studied. To investigate the phosphorylation and expression of candidate key molecular muscle mass regulators after immobilization and subsequent rehabilitation we performed two separate studies. METHODS: We immobilized the lower limb for 2...

  4. Laccase Immobilization by Chelated Metal Ion Coordination Chemistry

    Directory of Open Access Journals (Sweden)

    Qingqing Wang

    2014-09-01

    Full Text Available In this work, amidoxime polyacrylonitrile (AOPAN nanofibrous membrane was prepared by a reaction between PAN nanofibers and hydroxylamine hydrochloride. The AOPAN nanofibrous membranes were used for four metal ions (Fe3+, Cu2+, Ni2+, Cd2+ chelation under different conditions. Further, the competition of different metal ions coordinating with AOPAN nanofibrous membrane was also studied. The AOPAN chelated with individual metal ion (Fe3+, Cu2+, Ni2+, Cd2+ and also the four mixed metal ions were further used for laccase (Lac immobilization. Compared with free laccase, the immobilized laccase showed better resistance to pH and temperature changes as well as improved storage stability. Among the four individual metal ion chelated membranes, the stability of the immobilized enzymes generally followed the order as Fe–AOPAN–Lac > Cu–AOPAN–Lac > Ni–AOPAN–Lac > Cd–AOPAN–Lac. In addition, the immobilized enzyme on the carrier of AOPAN chelated with four mixed metal ions showed the best properties.

  5. [Synthesis of biodiesel from crude oil by immobilized lipase].

    Science.gov (United States)

    Li, Junkui; Lu, Jike; Wang, Fang; Tan, Tianwei; Deng, Li

    2009-06-01

    We used immobilized lipase from Candida sp. 99-125 to produce fatty acid methyl esters (FAMEs) from crude oil and methanol. We studied the effects of phospholipids on activity of immobilized lipase, reaction velocity, stability of immobilized lipase and the stability of immobilized lipase in crude and refined oil. Results showed that the activity of the lipase immersed in petroleum ether with 1% phospholipids dropped more quickly than the lipase in petroleum ether without phospholipids. When soybean oil was used without phospholipids as material, the FAMEs yield of 15 min was 26.2%, whereas the yield decreased to 12.4% when there were 5% phospholipids in the soybean oil. However when the phospholipids content was below 1%, the stability of the lipase did not change obviously. The lipase was stable when used to catalyze crude soybean oil and crude jatropha oil, after 10 cycles the FAMEs yield was still above 70%. This lipase showed great potential for industrial production of biodiesel from crude oil.

  6. Papain immobilized polyurethane as an ureteral stent material.

    Science.gov (United States)

    Maria Manohar, Cynthya; Doble, Mukesh

    2016-05-01

    Long term use of polyurethane-based ureteral stent is hampered by the development of infection due to the formation of bacterial biofilm and salt deposition. Here papain, is covalently immobilized to polyurethane using glutarldehyde and is investigated as a possible anti-infective ureteral stent material. Fourier transform infrared spectrum confirmed its immobilization. Immobilized enzyme retained 85% of the activity of the free enzyme and about 12% loss of enzyme was observed from the polymer surface in one month. The modified polyurethane showed 8 log reduction in Staphylococcus aureus and 7 log reduction in Escherichia coli live colonies and 3-4 times decrease in the protein and carbohydrate in the biofilms than bare polymer. The amount of calcium and magnesium salts deposited on the polymer surface reduced by 40% after enzyme immobilization. 80% of L6 myoblast cells were viable on this material which indicated that it was noncytotoxic. A linear regression equation with hydrophilicity of the polymer surface and the cell surface hydrophobicity as the two independent variables was able to predict the number of live cells attached on the modified PU. This study indicated the possibility of using such an approach to overcome the problems of ureteral stent associated biofilm and salt encrustation.

  7. Collagen immobilization on polyethylene terephthalate surface after helium plasma treatment

    Energy Technology Data Exchange (ETDEWEB)

    Aflori, Magdalena, E-mail: maflori@icmpp.ro [Department of Polymers Physics and Polymeric Materials, “Petru Poni” Institute of Macromolecular Chemistry, 41A Gr. Ghica Voda Alley, 700487 Iasi (Romania); Drobota, Mioara [Department of Polymers Physics and Polymeric Materials, “Petru Poni” Institute of Macromolecular Chemistry, 41A Gr. Ghica Voda Alley, 700487 Iasi (Romania); Dimitriu, Dan Gh. [Faculty of Physics, “Alexandru Ioan Cuza” University, 20A Bulevardul Carol I, 700505 Iasi (Romania); Stoica, Iuliana [Department of Polymers Physics and Polymeric Materials, “Petru Poni” Institute of Macromolecular Chemistry, 41A Gr. Ghica Voda Alley, 700487 Iasi (Romania); Simionescu, Bogdana [Department of Polymers Physics and Polymeric Materials, “Petru Poni” Institute of Macromolecular Chemistry, 41A Gr. Ghica Voda Alley, 700487 Iasi (Romania); “Costin D. Nenitescu” Centre of Organic Chemistry, 202B Splaiul Independentei, 71141 Bucharest (Romania); Harabagiu, Valeria [Department of Polymers Physics and Polymeric Materials, “Petru Poni” Institute of Macromolecular Chemistry, 41A Gr. Ghica Voda Alley, 700487 Iasi (Romania)

    2013-11-20

    An attractive alternative to add new functionalities such as biocompatibility due to the micro- and nano-scaled modification of polymer surfaces is offered by plasma processing. Many vital processes of tissue repair and growth following injuries depend on the rate of adsorption and self-assembling of the collagen molecules at the interfaces. Consequently, besides the amount of protein, it is necessary to investigate the form in which the collagen molecules are organizing on the polymer surface. In this study, direct current (DC) helium plasma treatment was used in order to obtain poly(ethylene terephthalate) (PET) films with different amounts of collagen and different shapes of aggregates formed from the collagen molecules. The immobilization of collagen on PET surface was confirmed by XPS measurements, an increase of the nitrogen content by increasing the plasma exposure time being recorded. The SEM and AFM measurements revealed the presence of grains and dendrites of collagen formed on the polymer surface. At 15 min plasma treatment time, the polymer surface after collagen immobilization has a homogenous topography. Usually, one can find fibrils, coil or dendrimers of collagen formed in buffer solutions and immobilized on different polymer surfaces. On the other hand, in this particular configuration, the combination of DC plasma and helium gas as a PET functionalization tool is an original one. As the collagen is not covalently immobilized on the surfaces, it may interact with the cell culture medium proteins, part of the collagen might being replaced by other serum proteins.

  8. Plutonium Immobilization Project Baseline Formulation

    Energy Technology Data Exchange (ETDEWEB)

    Ebbinghaus, B.

    1999-02-01

    A key milestone for the Immobilization Project (AOP Milestone 3.2a) in Fiscal Year 1998 (FY98) is the definition of the baseline composition or formulation for the plutonium ceramic form. The baseline formulation for the plutonium ceramic product must be finalized before the repository- and plant-related process specifications can be determined. The baseline formulation that is currently specified is given in Table 1.1. In addition to the baseline formulation specification, this report provides specifications for two alternative formulations, related compositional specifications (e.g., precursor compositions and mixing recipes), and other preliminary form and process specifications that are linked to the baseline formulation. The preliminary specifications, when finalized, are not expected to vary tremendously from the preliminary values given.

  9. Ceramic Hosts for Fission Products Immobilization

    Energy Technology Data Exchange (ETDEWEB)

    Peter C Kong

    2010-07-01

    metal ions, Mg and Ca, in the ceramic host phases. The immobilization of rear earth (lanthanide series) fission products in these ceramic host phases will also be studied this year. Cerium oxide is chosen to represent the rear earth fission product for substitution studies in spinel, perovskite and zirconolite ceramic hosts. Cerium has +3 and +4 oxidation states and it can replace some of the trivalent or tetravalent host ions to produce the substitution ceramics such as MgAl2-xCexO4, CaTi1-xCexO3, CaZr1-xCexTi2O7 and CaZrTi2-xCexO7. X-ray diffraction analysis will be used to compare the crystalline structures of the pure ceramic hosts and the substitution phases. SEM-EDX analysis will be used to study the Ce distribution in the ceramic host phases. The range of cerium doping is planned to reach the full substitution of the trivalent or tetravalent ions, Al, Ti and Zr, in the ceramic host phases.

  10. Treatment of landfill leachate by immobilized microorganisms

    Institute of Scientific and Technical Information of China (English)

    YE ZhengFang; YU HongYan; WEN LiLi; NI JinRen

    2008-01-01

    This paper focuses on the outcome and the main performance of the immobilized microbial that treats landfill leachate. Based on the analysis of COD and ammonia-nitrogen of the influent and effluent, research was done on the high removal efficiency of COD and ammonium nitrogen by immobilized microbial. The leachate composition was analyzed qualitatively using GC-MS before and after being treated. Biological loading of efficient microbial flora on the carrier was measured by Kjeldahl's method. Finally, the patterns of immobilized microbe were observed through scanning electron microscopy (SEM). The results showed that in immobilized microorganisms system, the efficiencies of COD and nitrogen were 98.3% and 99.9%, respectively. There was a great reduction of organic components in effluent. When the immobilized biomass on the carrier was 38 g·L-1 (H2O), the filamentous microorganism was highly developed. There was no inhibitory effect on the nitrobacteria and nitrococcus, when ammonia was over 200 mg·L-1 and NH3 over 150 mg·L-1, At a high organic loading, it still had good nitrification. This paper also compares the performance of immobilized microbial with free microbial under the same condition. The immobilized microbial technology demonstrated better than the latter in all aspects.

  11. Treatment of landfill leachate by immobilized microorganisms

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    This paper focuses on the outcome and the main performance of the immobilized microbial that treats landfill leachate. Based on the analysis of COD and ammonia-nitrogen of the influent and effluent, research was done on the high removal efficiency of COD and ammonium nitrogen by immobilized microbial. The leachate composition was analyzed qualitatively using GC-MS before and after being treated. Biological loading of efficient microbial flora on the carrier was measured by Kjeldahl’s method. Finally, the patterns of immobilized microbe were observed through scanning electron microscopy (SEM). The results showed that in immobilized microorganisms system, the efficiencies of COD and nitrogen were 98.3% and 99.9%, respectively. There was a great reduction of organic components in effluent. When the immobilized biomass on the carrier was 38 g·L?1 (H2O), the filamentous microorganism was highly developed. There was no inhibitory effect on the nitrobacteria and nitrococcus, when ammonia was over 200 mg·L?1 and NH3 over 150 mg·L?1. At a high organic loading, it still had good nitrification. This paper also compares the performance of immobilized microbial with free microbial under the same condition. The immobilized microbial technology demonstrated better than the latter in all aspects.

  12. Investigation of the Effect of Plasma Polymerized Siloxane Coating for Enzyme Immobilization and Microfluidic Device Conception

    Directory of Open Access Journals (Sweden)

    Kalim Belhacene

    2016-12-01

    Full Text Available This paper describes the impact of a physical immobilization methodology, using plasma polymerized 1,1,3,3, tetramethyldisiloxane, on the catalytic performance of β-galactosidase from Aspergillus oryzae in a microfluidic device. The β-galactosidase was immobilized by a polymer coating grown by Plasma Enhanced Chemical Vapor Deposition (PEVCD. Combined with a microchannel patterned in the silicone, a microreactor was obtained with which the diffusion through the plasma polymerized layer and the hydrolysis of a synthetic substrate, the resorufin-β-d-galactopyranoside, were studied. A study of the efficiency of the immobilization procedure was investigated after several uses and kinetic parameters of immobilized β-galactosidase were calculated and compared with those of soluble enzyme. Simulation and a modelling approach were also initiated to understand phenomena that influenced enzyme behavior in the physical immobilization method. Thus, the catalytic performances of immobilized enzymes were directly influenced by immobilization conditions and particularly by the diffusion behavior and availability of substrate molecules in the enzyme microenvironment.

  13. Antimicrobial Properties of Lysosomal Enzymes Immobilized on NH₂Functionalized Silica-Encapsulated Magnetite Nanoparticles.

    Science.gov (United States)

    Bang, Seung Hyuck; Sekhon, Simranjeet Singh; Cho, Sung-Jin; Kim, So Jeong; Le, Thai-Hoang; Kim, Pil; Ahn, Ji-Young; Kim, Yang-Hoon; Min, Jiho

    2016-01-01

    The immobilization efficiency, antimicrobial activity and recovery of lysosomal enzymes on NH2 functionalized magnetite nanoparticles have been studied under various conditions. The immobi- lization efficiency depends upon the ratio of the amount of enzyme and magnetite and it shows an increase with magnetite concentration which is due to the presence of amine group at the magnetite surface that leads to a strong attraction. The optimized reaction time to immobilize the lysosomal enzymes on magnetite was determined by using a rolling method. The immobilization efficiency increases with reaction time and reached a plateau after 5 minutes and then remained constant for 10 minutes. However, after 30 minutes the immobilization efficiency decreased to 85%, which is due to the weaker electrostatic interactions between magnetite and detached lysosomal enzymes. The recovery and stability of immobilized lysosomal enzymes has also been studied. The antimicrobial activity was almost 100% but it decreased upon reuse and no activity was observed after its reuse for seven times. The storage stability of lysosomal enzymes as an antimicrobial agent was about 88%, which decreased to 53% after one day and all activity of immobilized lysosomal enzymes was maintained after five days. Thus, the lysosomal enzymes immobilized on magnetite nanoparticles could potentially be used as antimicrobial agents to remove bacteria.

  14. Effective Immobilization of Agrobacterium sp. IFO 13140 Cells in Loofa Sponge for Curdlan Biosynthesis

    Directory of Open Access Journals (Sweden)

    Camila Ortiz Martinez

    2015-05-01

    Full Text Available Curdlan production by Agrobacterium sp. IFO13140 immobilized on loofa sponge, alginate and loofa sponge with alginate was investigated. There was no statistically-significant difference in curdlan production when the microorganism was immobilized in different matrices. The loofa sponge was chosen because of its practical application and economy and because it provides a high stability through its continued use. The best conditions for immobilization on loofa sponge were 50 mg of cell, 200 rpm and 72 h of incubation, which provided a curdlan production 1.50-times higher than that obtained by free cells. The higher volumetric productivity was achieved by immobilized cells (0.09 g/L/h at 150 rpm. The operating stability was evaluated, and until the fourth cycle, immobilized cells retained 87.40% of the production of the first cycle. The immobilized cells remained active after 300 days of storage at 4 °C. The results of this study demonstrate success in immobilizing cells for curdlan biosynthesis, making the process potentially suitable for industrial scale-up. Additional studies may show a possible contribution to the reduction of operating costs.

  15. Thermostable α-amylase immobilization: Enhanced stability and performance for starch biocatalysis.

    Science.gov (United States)

    Kumar, Gudi Satheesh; Rather, Gulam Mohmad; Gurramkonda, Chandrasekhar; Reddy, Bontha Rajasekhar

    2016-01-01

    The uses of thermostable starch hydrolytic biocatalysts are steadily increasing for the industrial application because of their obvious need for biocatalytic performance at elevated temperatures. The starch liquefaction and saccharification can be carried out simultaneously by the use of thermostable starch hydrolytic biocatalysts, thus minimizing the unit operations, time, and efforts. The cost factor hampers the industrialization of expensive soluble (free) enzymes for biocatalytic applications and the immobilization of enzymes offers promising alternative to the hurdle. The present investigation was aimed for immobilization of thermostable α-amylase using calcium alginate, and statistical optimization studies were carried out for enhanced biocatalytic performance. Initially, one-parameter at a time optimization studies were carried out for identification of significant factors influencing the immobilization. Furthermore, a statistical approach, response surface methodology, was applied for immobilization of α-amylase. The immobilized α-amylase in alginate microbeads showed enhanced stability to temperature and reusable property for up to seven cycles (with the retention of 50% initial activity). Finally, the kinetic behavior of free and immobilized enzyme showed the Km value of 1.2% and 2.6% (w/v) and Vmax of 1,020 and 1,030 U, respectively. Fifty percent reduction in affinity of the immobilized enzyme toward substrate was compensated by its longer stability.

  16. Surface cell immobilization within perfluoroalkoxy microchannels

    Energy Technology Data Exchange (ETDEWEB)

    Stojkovič, Gorazd; Krivec, Matic [Faculty of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva 5, SI-1000 Ljubljana (Slovenia); Vesel, Alenka [Jožef Stefan Institute, Jamova cesta 39, 1000 Ljubljana (Slovenia); Marinšek, Marjan [Faculty of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva 5, SI-1000 Ljubljana (Slovenia); Žnidaršič-Plazl, Polona, E-mail: polona.znidarsic@fkkt.uni-lj.si [Faculty of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva 5, SI-1000 Ljubljana (Slovenia)

    2014-11-30

    Graphical abstract: - Highlights: • A very efficient approach for immobilization of cells into microreactors is presented. • It is applicable to various materials, including PFA and cyclic olefin (co)polymers. • It was used to immobilize different prokaryotic and eukaryotic microbes. • Cells were immobilized on the surface in high density and showed good stability. • Mechanisms of APTES interactions with target materials are proposed. - Abstract: Perfluoroalkoxy (PFA) is one of the most promising materials for the fabrication of cheap, solvent resistant and reusable microfluidic chips, which have been recently recognized as effective tools for biocatalytic process development. The application of biocatalysts significantly depends on efficient immobilization of enzymes or cells within the reactor enabling long-term biocatalyst use. Functionalization of PFA microchannels by 3-aminopropyltriethoxysilane (ATPES) and glutaraldehyde was used for rapid preparation of microbioreactors with surface-immobilized cells. X-ray photoelectron spectroscopy and scanning electron microscopy were used to accurately monitor individual treatment steps and to select conditions for cell immobilization. The optimized protocol for Saccharomyces cerevisiae immobilization on PFA microchannel walls comprised ethanol surface pretreatment, 4 h contacting with 10% APTES aqueous solution, 10 min treatment with 1% glutaraldehyde and 20 min contacting with cells in deionized water. The same protocol enabled also immobilization of Escherichia coli, Pseudomonas putida and Bacillus subtilis cells on PFA surface in high densities. Furthermore, the developed procedure has been proved to be very efficient also for surface immobilization of tested cells on other materials that are used for microreactor fabrication, including glass, polystyrene, poly (methyl methacrylate), polycarbonate, and two olefin-based polymers, namely Zeonor{sup ®} and Topas{sup ®}.

  17. Immobilized cell technology in beer brewing: Current experience and results

    Directory of Open Access Journals (Sweden)

    Leskošek-Čukalov Ida J.

    2005-01-01

    Full Text Available Immobilized cell technology (ICT has been attracting continual attention in the brewing industry over the past 30 years. Some of the reasons are: faster fermentation rates and increased volumetric productivity, compared to those of traditional beer production based on freely suspended cells, as well as the possibility of continuous operation. Nowadays, ICT technology is well established in secondary fermentation and alcohol- free and low-alcohol beer production. In main fermentation, the situation is more complex and this process is still under scrutiny on both the lab and pilot levels. The paper outlines the most important ICT processes developed for beer brewing and provides an overview of carrier materials, bioreactor design and examples of their industrial applications, as well as some recent results obtained by our research group. We investigated the possible applications of polyvinyl alcohol in the form of LentiKats®, as a potential porous matrices carrier for beer fermentation. Given are the results of growth studies of immobilized brewer's yeast Saccharomyces uvarum and the kinetic parameters obtained by using alginate microbeads with immobilized yeast cells and suspension of yeast cells as controls. The results indicate that the immobilization procedure in LentiKat® carriers has a negligible effect on cell viability and growth. The apparent specific growth rate of cells released in medium was comparable to that of freely suspended cells, implying preserved cell vitality. A series of batch fermentations performed in shaken flasks and an air-lift bioreactor indicated that the immobilized cells retained high fermentation activity. The full attenuation in green beer was reached after 48 hours in shaken flasks and less than 24 hours of fermentation in gas-lift bioreactors.

  18. Covalent immobilization of p-selectin enhances cell rolling.

    Science.gov (United States)

    Hong, Seungpyo; Lee, Dooyoung; Zhang, Huanan; Zhang, Jennifer Q; Resvick, Jennifer N; Khademhosseini, Ali; King, Michael R; Langer, Robert; Karp, Jeffrey M

    2007-11-20

    Cell rolling is an important physiological and pathological process that is used to recruit specific cells in the bloodstream to a target tissue. This process may be exploited for biomedical applications to capture and separate specific cell types. One of the most commonly studied proteins that regulate cell rolling is P-selectin. By coating surfaces with this protein, biofunctional surfaces that induce cell rolling can be prepared. Although most immobilization methods have relied on physisorption, chemical immobilization has obvious advantages, including longer functional stability and better control over ligand density and orientation. Here we describe chemical methods to immobilize P-selectin covalently on glass substrates. The chemistry was categorized on the basis of the functional groups on modified glass substrates: amine, aldehyde, and epoxy. The prepared surfaces were first tested in a flow chamber by flowing microspheres functionalized with a cell surface carbohydrate (sialyl Lewis(x)) that binds to P-selectin. Adhesion bonds between P-selectin and sialyl Lewis(x) dissociate readily under shear forces, leading to cell rolling. P-selectin immobilized on the epoxy glass surfaces exhibited enhanced long-term stability of the function and better homogeneity as compared to that for surfaces prepared by other methods and physisorbed controls. The microsphere rolling results were confirmed in vitro with isolated human neutrophils. This work is essential for the future development of devices for isolating specific cell types based on cell rolling, which may be useful for hematologic cancers and certain metastatic cancer cells that are responsive to immobilized selectins.

  19. Cellulose hydrolysis by immobilized Trichoderma reesei cellulase.

    Science.gov (United States)

    Jones, Paetrice O; Vasudevan, Palligarnai T

    2010-01-01

    Cellulose hydrolysis by immobilized Trichoderma reesei cellulase in the presence of a low viscosity ionic liquid, 1-ethyl-3-methylimidazolium diethyl phosphate (EMIM-DEP), was investigated. Preparation of the carrier-free immobilized cellulase was optimized with respect to concentration of the cross-linker and the type of precipitant. The addition of 2% (v/v) EMIM-DEP during hydrolysis gave an initial reaction rate 2.7 times higher than the hydrolysis rate with no ionic liquid. The initial yield after 2 h was 0.7 g glucose/g cellulose, and the carrier-free immobilized cellulase (CFIC) was effectively re-used five times.

  20. Immobilization of biomolecules on semiconductor surfaces

    Science.gov (United States)

    Joensson, U.; Malmqvist, M.; Nilsson, H.; Olofsson, G.; Roennberg, I.

    1983-09-01

    A reproducible, stable and functional introduction of reactive groups on oxide covered silicon surfaces used in chemically sensitive field effect transistors and optical methods based on light reflection is described. Biomolecules, such as antibodies, antigens and enzymes, were covalently attached to the surface modified silicon via a thiol disulfide exchange reaction. The immobilization technique eliminates the risk of crosslinking and homopolymerization, giving monolayer coverage in close contact with the surface. The technique was used for immobilized protein A and interaction of such surfaces with immunoglobulins. The result was evaluated by in situ ellipsometry, which gives the amount of immobilized and interacting material on the surfaces.

  1. Application of Klebsiella oxytoca immobilized cells on the treatment of cyanide wastewater.

    Science.gov (United States)

    Chen, C Y; Kao, C M; Chen, S C

    2008-03-01

    Klebsiella oxytoca, isolated from cyanide-containing industrial wastewater, has been shown to be able to biodegrade cyanide to non-toxic end products. The technology of immobilized cells can be applied in biological treatment to enhance the efficiency and effectiveness of biodegradation. In this study, potassium cyanide was used as the target compound and both alginate and cellulose triacetate techniques were applied for the preparation of immobilized cells. Results from this study show that KCN can be utilized as the sole nitrogen source by K. oxytoca. The free suspension systems reveal that the cell viability was highly affected by initial KCN concentration and pH. Results show that immobilized cell systems could tolerate a higher level of KCN concentration and wider ranges of pH. In the batch experiments, the maximum KCN removal efficiencies using alginate and cellulose triacetate immobilized beads were 0.108 and 0.101mM h(-1) at pH 7, respectively. Results also indicate that immobilized system can support a higher biomass concentration. Complete KCN degradation was observed after the operation of four consecutive degradation experiments with the same batch of immobilized cells. This suggests that the activity of immobilized cells can be maintained and KCN can be used as the nitrogen source throughout KCN degradation experiments. The maximum KCN removal rates using alginate and cellulose triacetate immobilized beads in continuous-column system were 0.224 and 0.192mMh(-1) with initial KCN concentration of 3mM, respectively. Results indicate that the immobilized cells of K. oxytoca would be applicable to the treatment of cyanide-containing wastewaters.

  2. Silk-Cocoon Matrix Immobilized Lipase Catalyzed Transesterification of Sunflower Oil for Production of Biodiesel

    Directory of Open Access Journals (Sweden)

    Sushovan Chatterjee

    2014-01-01

    Full Text Available Biodiesel from sunflower oil using lipase chemically immobilized on silk-cocoon matrix in a packed-bed bioreactor was investigated. The immobilization was demonstrated by field-emission scanning electron microscopy and activity study. The lipase loading was 738.74 U (~0.01 g lipase powder/g-lipase-immobilized matrix. The Km (Michaelis-Menten constant of the free and the immobilized lipase was 451.26 μM and 257.26 μM, respectively. Low Km value of the immobilized lipase is attributed to the hydrophobic nature of the matrix that facilitated the substrate diffusion to the enzyme surface. The biodiesel yield of 81.62% was obtained at 48 hours reaction time, 6 : 1 methanol : oil ratio (v/v, and 30°C. The immobilized lipase showed high operational stability at 30°C. The substrate conversion was only marginally decreased till third cycle (each of 48 hours duration of the reaction since less than even 5% of the original activity was decreased in each of the second and third cycle. The findings demonstrated the potential of the silk-cocoon as lipase immobilization matrix for industrial production of biodiesel.

  3. Immobilization of Lipases Produced by the Endophytic Fungus Cercospora kikuchii on Chitosan Microparticles

    Directory of Open Access Journals (Sweden)

    Lara Aparecida Buffoni Campos Carneiro

    2014-08-01

    Full Text Available This work studied the immobilization of Cercospora kikuchii lipases on chitosan microparticles by chemical attachment on chitosan acetate microparticles activated by glutaraldehyde (CAM added before or after the enzyme and physical adsorption on highly deacetylated chitosan hydrochloride microparticles (CHM. Lipases covalently immobilized on pre-activated CAM showed better performance retaining 88.4% of the enzymatic activity, with 68.2% of immobilization efficiency (IE. The immobilized enzyme retained an activity of about 53.5 % after five reuses, using p-NPP as substrate. Physical adsorption of lipase onto highly deacetylated CHM showed 46.2 % of enzymatic activity and 28.6% of IE. This immobilized derivative did not lose activity up to 80 days of storage at 4°C, while lipases immobilized on pre-activated CAM maintained its activity up to 180 days at same conditions. Taken together the results indicate that chitosan microparticles provide an optimal microenvironment for the immobilized enzyme to maintain good activity and stability.

  4. Assessment of the ecological security of immobilized enzyme remediation process with biological indicators of soil health.

    Science.gov (United States)

    Zhang, Ying; Dong, Xiaonan; Jiang, Zhao; Cao, Bo; Ge, Shijie; Hu, Miao

    2013-08-01

    This study used the enzymes extracted from an atrazine-degrading strain, Arthrobacter sp. DNS10, which had been immobilized by sodium alginate to rehabilitate atrazine-polluted soil. Meanwhile, a range of biological indices were selected to assess the ecological health of contaminated soils and the ecological security of this bioremediation method. The results showed that there was no atrazine detected in soil samples after 28 days in EN+AT (the soil containing atrazine and immobilized enzyme) treatment. However, the residual atrazine concentration of the sample in AT (the soil containing atrazine only) treatment was about 5.02 ± 0.93 mg kg(-1). These results suggest that the immobilized enzyme exhibits an excellent ability in atrazine degradation. Furthermore, the immobilized enzyme could relieve soil microbial biomass carbon and soil microbial respiration intensity to 772.33 ± 34.93 mg C kg(-1) and 5.01 ± 0.17 mg CO(2) g(-1) soil h(-1), respectively. The results of the polymerase chain reaction-degeneration gradient gel electrophoresis experiment indicated that the immobilized enzyme also could make the Shannon-Wiener index and evenness index of the soil sample increase from 1.02 and 0.74 to 1.51 and 0.84, respectively. These results indicated that the immobilized enzymes not only could relieve the impact from atrazine on the soil, but also revealed that the immobilized enzymes did no significant harm on the soil ecological health.

  5. Corticospinal adaptations and strength maintenance in the immobilized arm following 3 weeks unilateral strength training.

    Science.gov (United States)

    Pearce, A J; Hendy, A; Bowen, W A; Kidgell, D J

    2013-12-01

    Cross-education strength training has being shown to retain strength and muscle thickness in the immobilized contralateral limb. Corticospinal mechanisms have been proposed to underpin this phenomenon; however, no transcranial magnetic stimulation (TMS) data has yet been presented. This study used TMS to measure corticospinal responses following 3 weeks of unilateral arm training on the contralateral, immobilize arm. Participants (n = 28) were randomly divided into either immobilized strength training (Immob + train) immobilized no training (Immob) or control. Participants in the immobilized groups had their nondominant arm rested in a sling, 15 h/day for 3 weeks. The Immob + train group completed unilateral arm curl strength training, while the Immob and control groups did not undertake training. All participants were tested for corticospinal excitability, strength, and muscle thickness of both arms. Immobilization resulted in a group x time significant reduction in strength, muscle thickness and corticospinal excitability for the untrained limb of the Immob group. Conversely, no significant change in strength, muscle thickness, or corticospinal excitability occurred in the untrained limb of the Immob + train group. These results provide the first evidence of corticospinal mechanisms, assessed by TMS, underpinning the use of unilateral strength training to retain strength and muscle thickness following immobilization of the contralateral limb.

  6. Effect of Cultivation Time and Medium Condition in Production of Bacterial Cellulose Nanofiber for Urease Immobilization

    Directory of Open Access Journals (Sweden)

    M. Pesaran

    2015-01-01

    Full Text Available A new nanoporous biomatrix originated from bacterial resources has been chosen for urease immobilization. Urease has been immobilized on synthesized bacterial cellulose nanofiber since this enzyme has a key role in nitrogen metabolism. Gluconacetobacter xylinum ATCC 10245 has been cultivated for synthesis of a nanofiber with the diameter of 30–70 nm. Different cultivation processes in the aspect of time and cultivation medium conditions were chosen to study the performance of immobilized enzyme on four types of bacterial cellulose nanofibers (BCNs. Urease immobilization into the nanofiber has been done in two steps: enzyme adsorption and glutaraldehyde cross-linking. The results showed that the immobilized enzymes were relatively active and highly stable compared to the control samples of free enzymes. Optimum pH was obtained 6.5 and 7 for different synthesized BCNs, while the optimum temperature for immobilized urease was 50°C. Finding of the current experiment illustrated that the immobilized enzyme in optimum condition lost its initial activity by 41% after 15 weeks.

  7. Preparation of a Cu(II-PVA/PA6 Composite Nanofibrous Membrane for Enzyme Immobilization

    Directory of Open Access Journals (Sweden)

    Dayin Hou

    2012-10-01

    Full Text Available PVA/PA6 composite nanofibers were formed by electrospinning. Cu(II-PVA/PA6 metal chelated nanofibers, prepared by the reaction between PVA/PA6 composite nanofibers and Cu2+ solution, were used as the support for catalase immobilization. The result of the experiments showed that PVA/PA6 composite nanofibers had an excellent chelation capacity for Cu2+ ions, and the structures of nanofibers were stable during the reaction with Cu2+ solution. The adsorption of Cu(II onto PVA/PA6 composite nanofibers was studied by the Langmuir isothermal adsorption model. The maximum amount of coordinated Cu(II (qm was 3.731 mmol/g (dry fiber, and the binding constant (Kl was 0.0593 L/mmol. Kinetic parameters were analyzed for both immobilized and free catalases. The value of Vmax (3774 μmol/mg·min for the immobilized catalases was smaller than that of the free catalases (4878 μmol/mg·min, while the Km for the immobilized catalases was larger. The immobilized catalases showed better resistance to pH and temperature than that of free form, and the storage stabilities, reusability of immobilized catalases were significantly improved. The half-lives of free and immobilized catalases were 8 days and 24 days, respectively.

  8. Evaluation of free and immobilized Aspergillus niger NRC1ami pectinase applicable in industrial processes.

    Science.gov (United States)

    Esawy, Mona A; Gamal, Amira A; Kamel, Zeinat; Ismail, Abdel-Mohsen S; Abdel-Fattah, Ahmed F

    2013-02-15

    The Aspergillus niger NRC1ami pectinase was evaluated according to its hydrolysis efficiency of dry untreated orange peels (UOP), HCl-treated orange peels and NaOH-treated orange peels (HOP and NOP). Pectinase was entrapped in polyvinyl alcohol (PVA) sponge and the optimum pH and temperature of the free and immobilized enzymes were shifted from 4, 40 °C to 6, 50 °C respectively. The study of pH stability of free and immobilized pectinase showed that the immobilization process protected the enzyme strongly from severe alkaline pHs. The immobilization process improved the enzyme thermal stability to great instant. The unique feature of the immobilization process is its ability to solve the orange juice haze problem completely. Immobilized enzyme was reused 12 times in orange juice clarification with 9% activity loss from the original activity. Maximum reaction rate (V(max)) and Michaelis-Menten constant (K(m)) of the partially purified form were significantly changed after immobilization.

  9. Immobilization and controlled release of drug using plasma polymerized thin film

    Energy Technology Data Exchange (ETDEWEB)

    Myung, Sung-Woon [Department of Dental Materials, School of Dentistry, MRC Center, Chosun University, 309 Pilmun-daero, Dong-gu, Gwangju (Korea, Republic of); Jung, Sang-Chul [Department of Environmental Engineering, Sunchon National University, Sunchon 540-742 (Korea, Republic of); Kim, Byung-Hoon, E-mail: kim5055@chosun.ac.kr [Department of Dental Materials, School of Dentistry, MRC Center, Chosun University, 309 Pilmun-daero, Dong-gu, Gwangju (Korea, Republic of)

    2015-06-01

    In this study, plasma polymerization of acrylic acid was employed to immobilize drug and control its release. Doxorubicin (DOX) was immobilized covalently on the glass surface deposited with plasma polymerized acrylic acid (PPAAc) thin film containing the carboxylic group. At first, the PPAAc thin film was coated on a glass surface at a pressure of 1.33 Pa and radio frequency (RF) discharge power of 20 W for 10 min. DOX was immobilized on the PPAAc deposition in a two environment of phosphate buffer saline (PBS) and dimethyl sulfoxide (DMSO) solutions. The DOX immobilized surface was characterized by scanning electron microscope, atomic force microscope and attenuated total reflection Fourier transform infrared spectroscopy. The DOX molecules were more immobilized in PBS than DMSO solution. The different immobilization and release profiles of DOX result from the solubility of hydrophobic DOX in aqueous and organic solutions. Second, in order to control the release of the drug, PPAAc thin film was covered over DOX dispersed layer. Different thicknesses and cross-linked PPAAc thin films by adjusting deposition time and RF discharge power were covered on the DOX layer dispersed. PPAAc thin film coated DOX layer reduced the release rate of DOX. The thickness control of plasma deposition allows controlling the release rate of drug. - Highlights: • Doxorubicin was immobilized on the surface of plasma polymerized acrylic acid thin film. • Release profile of doxorubicin was affected by aqueous and organic solutions. • Plasma polymerized acrylic acid thin film can be used to achieve controlled release.

  10. Immobilization of microbial cell and yeast cell and its application to biomass conversion using radiation techniques

    Science.gov (United States)

    Kaetsu, Isao; Kumakura, Minoru; Fujimura, Takashi; Kasai, Noboru; Tamada, Masao

    The recent results of immobilization of cellulase-producing cells and ethanol-fermentation yeast by radiation were reported. The enzyme of cellulase produced by immobilized cells was used for saccharification of lignocellulosic wastes and immobilized yeast cells were used for fermentation reaction from glucose to ethanol. The wastes such as chaff and bagasse were treated by γ-ray or electron-beam irradiation in the presence of alkali and subsequent mechanical crushing, to form a fine powder less than 50 μm in diameter. On the other hand, Trichoderma reesei as a cellulase-producing microbial cell was immobilized on a fibrous carrier having a specific porous structure and cultured to produce cellulase. The enzymatic saccharification of the pretreated waste was carried out using the produced cellulase. The enhanced fermentation process to produce ethanol from glucose with the immobilized yeast by radiation was also studied. The ethanol productivity of immobilized growing yeast cells thus obtained was thirteen times that of free yeast cells in a 1:1 volume of liquid medium to immobilized yeast cells.

  11. Pigeonpea (Cajanus cajan L.) urease immobilized on glutaraldehyde-activated chitosan beads and its analytical applications.

    Science.gov (United States)

    Kayastha, A M; Srivastava, P K

    2001-01-01

    Urease from pigeonpea (Cajanus cajan L.) was covalently linked to crab shell chitosan beads using glutaraldehyde. The optimum immobilization (64% activity) was observed at 4 degrees C, with a protein concentration of 0.24 mg/bead and 3% glutaraldehyde. The immobilized enzyme stored in 0.05 M Tris-acetate buffer, pH 7.3, at 4 degrees C had a t(1/2) of 110 d. There was practically no leaching of enzyme (chitosan-immobilized urease showed a significantly higher Michaelis constant (8.3 mM) compared to that of the soluble urease (3.0 mM). Its apparent optimum pH also shifted from 7.3 to 8.5. Immobilized urease showed an optimal temperature of 77 degrees C, compared with 47 degrees C for the soluble urease. Time-dependent kinetics of the thermal denaturation of immobilized urease was studied and found to be monophasic in nature compared to biphasic in nature for soluble enzyme. This immobilized urease was used to analyze blood urea of some of the clinical samples from the clinical pathology laboratories. The results compared favorably with those obtained by the various chemical/biochemical methods employed in the clinical pathology laboratories. A column packed with immobilized urease beads was also prepared in a syringe for the regular and continuous monitoring of serum urea concentrations.

  12. Arsenic immobilization in the contaminated soil using poorly crystalline Fe-oxyhydroxy sulfate.

    Science.gov (United States)

    Yang, Zhihui; Liu, Lin; Chai, Liyuan; Liao, Yingping; Yao, Wenbin; Xiao, Ruiyang

    2015-08-01

    A low crystalline Fe-oxyhydroxy sulfate (FeOS) was used to immobilize arsenic (As) in soils in this study. The effects of FeOS amount, treatment time and soil moisture on As immobilization were investigated. The results showed that water-soluble and NaHCO3-extractable As were immobilized by 53.4-99.8 and 13.8-73.3% respectively, with 1-10% of FeOS addition. The highest immobilization of water-soluble (98.5%) and NaHCO3-extractable arsenic (47.2%) was achieved under condition of 4% of FeOS and 80% of soil moisture. Further, more amounts of FeOS addition resulted in less time requirement for As immobilization. Sequential chemical extraction experiment revealed that easily mobile arsenic phase was transferred to less mobile phase. The FeOS-bonded As may play a significant role in arsenic immobilization. Under leaching with simulated acid rain at 60 times pore volumes, accumulation amount of As release from untreated soil and soil amended with FeOS were 98.4 and 1.2 mg, respectively, which correspond to 7.69 and 0.09% of total As amounts in soil. The result showed that the low crystalline FeOS can be used as a suitable additive for arsenic immobilization in soils.

  13. Preparation of a Cu(II)-PVA/PA6 composite nanofibrous membrane for enzyme immobilization.

    Science.gov (United States)

    Feng, Quan; Tang, Bin; Wei, Qufu; Hou, Dayin; Bi, Songmei; Wei, Anfang

    2012-10-05

    PVA/PA6 composite nanofibers were formed by electrospinning. Cu(II)-PVA/PA6 metal chelated nanofibers, prepared by the reaction between PVA/PA6 composite nanofibers and Cu2+ solution, were used as the support for catalase immobilization. The result of the experiments showed that PVA/PA6 composite nanofibers had an excellent chelation capacity for Cu2+ ions, and the structures of nanofibers were stable during the reaction with Cu2+ solution. The adsorption of Cu(II) onto PVA/PA6 composite nanofibers was studied by the Langmuir isothermal adsorption model. The maximum amount of coordinated Cu(II) (q(m)) was 3.731 mmol/g (dry fiber), and the binding constant (K(l)) was 0.0593 L/mmol. Kinetic parameters were analyzed for both immobilized and free catalases. The value of V(max) (3774 μmol/mg·min) for the immobilized catalases was smaller than that of the free catalases (4878 μmol/mg·min), while the K(m) for the immobilized catalases was larger. The immobilized catalases showed better resistance to pH and temperature than that of free form, and the storage stabilities, reusability of immobilized catalases were significantly improved. The half-lives of free and immobilized catalases were 8 days and 24 days, respectively.

  14. MC3T3-E1 Cells on Titanium Surfaces with Nanometer Smoothness and Fibronectin Immobilization

    Directory of Open Access Journals (Sweden)

    Tohru Hayakawa

    2012-01-01

    Full Text Available The present study was aimed to evaluate the viability and total protein contents of osteoblast-like cells on the titanium surface with different surface mechanical treatment, namely, nanometer smoothing (Ra: approximately 2.0 nm and sandblasting (Ra: approximately 1.0 μm, and biochemical treatment, namely, with or without fibronectin immobilization. Fibronectin could be easily immobilized by tresyl chloride-activation technique. MC3T3-E1 cells were seeded on the different titanium surfaces. Cell viability was determined by MTT assay. At 1 day of cell culture, there were no significant differences in cell viability among four different titanium surfaces. At 11 days, sandblasted titanium surface with fibronectin immobilization showed the significantly highest cell viability than other titanium surface. No significant differences existed for total protein contents among four different titanium surfaces at 11 days of cell culture. Scanning electron microscopy observation revealed that smoothness of titanium surface produced more spread cell morphologies, but that fibronectin immobilization did not cause any changes of the morphologies of attached cells. Fibronectin immobilization provided greater amount of the number of attached cells and better arrangement of attached cells. In conclusion, the combination of sandblasting and fibronectin immobilization enhanced the cell viability and fibronectin immobilization providing better arrangements of attached cells.

  15. Degradation of h-acid by free and immobilized cells of Alcaligenes latus

    Directory of Open Access Journals (Sweden)

    M.S. Usha

    2010-12-01

    Full Text Available Alcaligenes latus, isolated from industrial effluent, was able to grow in mineral salts medium with 50 ppm (0.15 mM of H-acid as a sole source of carbon. Immobilization of Alcaligenes latus in Ca-alginate and polyurethane foam resulted in cells embedded in the matrices. When free cells and immobilized cells were used for biodegradation studies at concentration ranging from 100 ppm (0.3 mM to 500 ppm (1.15 mM degradation rate was enhanced with immobilized cells. Cells immobilized in polyurethane foam showed 100% degradation up to 350 ppm (1.05 mM and 57% degradation at 500 ppm (1.5 mM. Degradation rate of Ca-alginate immobilized cells was less as compared to that of polyurethane foam immobilized cells. With Ca-alginate immobilized cells 100% degradation was recorded up to 200 ppm (0.6 mM of H-acid and only 33% degradation was recorded at 500 ppm (1.5 mM of H-acid. Spectral analysis of the products after H-acid utilization showed that the spent medium did not contain any aromatic compounds indicating H-acid degradation by A. latus.

  16. Catalytic Activity and Photophysical Properties of Biomolecules Immobilized on Mesoporous Silica

    DEFF Research Database (Denmark)

    Ikemoto, Hideki

    hybrid materials used for further study. One metalloenzyme, horseradish peroxidase(HRP), was immobilized on rod-shaped SBA-15 by physical adsorption. The catalytic activity of free and immobilized enzyme was first compared at room temperature. Details of the enzyme kinetics including the apparent...... and increased hydration strength of the protein inside the nanopores. A copper-containing enzyme, galactose oxidase (GAOX), was immobilized on SBA-15 with a hexagonally ordered pore structure, or on mesocellular foam (MCF)-type mesoporous silica with a cage-like pore structure. Physical adsorption...

  17. Experimental joint immobilization in guinea pigs. Effects on the knee joint

    Science.gov (United States)

    Marcondesdesouza, J. P.; Machado, F. F.; Sesso, A.; Valeri, V.

    1980-01-01

    In young and adult guinea pigs, the aftermath experimentally induced by the immobilization of the knee joint in hyperextended forced position was studied. Joint immobilization which varied from one to nine weeks was attained by plaster. Eighty knee joints were examined macro and microscopically. Findings included: (1) muscular hypotrophy and joint stiffness in all animals, directly proportional to the length of immobilization; (2) haemoarthrosis in the first week; (3) intra-articular fibrous tissue proliferation ending up with fibrous ankylosis; (4) hyaline articular cartilage erosions; (5) various degrees of destructive menisci changes. A tentative explanation of the fibrous tissue proliferation and of the cartilage changes is offered.

  18. Removal of lead in wastewater by immobilized inactivated cells of Rhizopus oligosporus

    Institute of Scientific and Technical Information of China (English)

    于霞; 柴立元; 闵小波

    2003-01-01

    A novel technology for lead removal with nonliving Rhizopus oligosporus immobilized in calcium alginate was studied. The results show that the main influencing factors include pH value and interfering cations. pH value has different effects on biosorption of various heavy metals and lead adsorption can be proceeded by controlling pH value in a range of 2-5; interfering cations especially Cu( Ⅱ ) can make the adsorption amount of Pb( Ⅱ ) decrease by immobilized Rhizopus oligosporus. Desorption efficiency of different eluants and kinetics were investigated. Citrate the reaction equilibrium reaches 3 h. Immobilized biomass keeps high lead biosorption capacity after five cycles of regeneration.

  19. ENHANCED PRODUCTION OF PECTINOLYTIC ENZYMES FROM IMMOBILIZED CELLS OF MIXED ASPERGILLUS SPECIES

    Directory of Open Access Journals (Sweden)

    Shruti Singh

    2012-12-01

    Full Text Available The cells of isolated mixed culture of Aspergillus fumigatus and Aspergillus sydowii were immobilized in calcium alginate beads. Studies were carried out on different parameters like alginate concentration, incubation time and bead inoculum which affects the productivity and stability of the immobilized system. The best enzymatic activities were obtained with 3% alginate concentration, 48h of incubation time and 200 beads/flask of inoculum. Optimization of these factors causes an increase in enzymatic activities and the possibility of semicontinuous cultivation. Immobilized cells could be reused in five successive reaction cycles with a slight decrease in activities.

  20. Tendon and ligament adaptation to exercise, immobilization, and remobilization.

    Science.gov (United States)

    Wren, T A; Beaupré, G S; Carter, D R

    2000-01-01

    This study provides a theoretical and computational basis for understanding and predicting how tendons and ligaments adapt to exercise, immobilization, and remobilization. In a previous study, we introduced a model that described the growth and development of tendons and ligaments. In this study, we use the same model to predict changes in the cross-sectional area, modulus, and strength of tendons and ligaments due to increased or decreased loading. The model predictions are consistent with the results of experimental exercise and immobilization studies performed by other investigators. These results suggest that the same fundamental principles guide both development and adaptation. A basic understanding of these principles can contribute both to prevention of tendon and ligament injuries and to more effective rehabilitation when injury does occur.

  1. Study of the Immobilized Yeast Fermentation Process of Papaya and Passion Fruit Compound Wine%固定化酵母发酵木瓜-西番莲复合果酒工艺的研究

    Institute of Scientific and Technical Information of China (English)

    黄夏; 潘嫣丽; 农志荣; 黄卫萍; 黄友琴

    2012-01-01

    [ Objective] To study the best conditions for the immobilized yeast fermentation of papaya and passion fniit compound wine. [ Method ] Papaya and passion fruit were used as raw material to study the effects trf sugar content, pH, the amount of immobilized yeast and fermentation temperature an the contents of residua] sugar and alcohol, as well as ihe sensory quality of papaya and passion fruit compound wine. [ Result] The initial sugar content of papaya and passion fruit was the major factor influencing the residual sugar and alcohol content, as well as the sensory quality of the wine. The optimum fermentation conditions were 28% initial sugar content of mixed fruit juice, pH 4. 5, 0. 015% amount of yeast with a fermentation temperature of 25 . [Conclusion] Under the best conditions, the papaya and passion fruit compound wine with light yellow color, harmonious aroma of fruits and wme, fresh taste and 13.8% alcohol content wu produced.%[目的]研究固定化酵母发酵木瓜-西番莲复合果酒的最佳工艺条件.[方法]以木瓜和西番莲果为原料,研究了初始加糖量、pH、固定化酵母接种量、发酵温度对木瓜-西番莲复合果酒残糖、酒精度和感官品质的影响.[结果]影响木瓜西番莲复合果酒发酵残糖、酒精度和感官品质的主要因素为复合果汁初始加糖量,最佳发酵条件为混合果汁起始糖度28%、pH 4.5、酵母接种量0.015%、发酵温度25℃.[结论]在最佳工艺条件下可获得色泽淡黄自然、拥有着和谐的果香与酒香、入口清爽、酒精含量约13.8%的木瓜-西番莲复合果酒.

  2. Degradation of phenol and TCE using suspended and chitosan-bead immobilized Pseudomonas putida.

    Science.gov (United States)

    Chen, Yan-Min; Lin, Tsair-Fuh; Huang, Chih; Lin, Jui-Che; Hsieh, Feng-Ming

    2007-09-30

    The degradability of phenol and trichloroethene (TCE) by Pseudomonas putida BCRC 14349 in both suspended culture and immobilized culture systems are investigated. Chitosan beads at a size of about 1-2mm were employed to encapsulate the P. putida cells, becoming an immobilized culture system. The phenol concentration was controlled at 100 mg/L, and that of TCE was studied from 0.2 to 20 mg/L. The pH, between 6.7 and 10, did not affect the degradation of either phenol or TCE in the suspended culture system. However, it was found to be an important factor in the immobilized culture system in which the only significant degradation was observed at pH >8. This may be linked to the surface properties of the chitosan beads and its influence on the activity of the bacteria. The transfer yield of TCE on a phenol basis was almost the same for the suspended and immobilized cultures (0.032 mg TCE/mg phenol), except that these yields occurred at different TCE concentrations. The transfer yield at a higher TCE concentration for the immobilized system suggested that the cells immobilized in carriers can be protected from harsh environmental conditions. For kinetic rate interpretation, the Monod equation was employed to describe the degradation rates of phenol, while the Haldane's equation was used for TCE degradation. Based on the kinetic parameters obtained from the two equations, the rate for the immobilized culture systems was only about 1/6 to that of the suspended culture system for phenol degradation, and was about 1/2 for TCE degradation. The slower kinetics observed for the immobilized culture systems was probably due to the slow diffusion of substrate molecules into the beads. However, compared with the suspended cultures, the immobilized cultures may tolerate a higher TCE concentration as much less inhibition was observed and the transfer yield occurred at a higher TCE concentration.

  3. Immobilization of Rocky Flats Graphite Fines Residue

    Energy Technology Data Exchange (ETDEWEB)

    Rudisill, T.S.

    1999-04-06

    The development of the immobilization process for graphite fines has proceeded through a series of experimental programs. The experimental procedures and results from each series of experiments are discussed in this report.

  4. Nitrogenase activity of immobilized Azotobacter vinelandii.

    Science.gov (United States)

    Seyhan, E; Kirwan, D J

    1979-02-01

    As part of a program to investigate the use of biological nitrogen fixation for fertilizer ammonia production, an investigation into the immobilization of the aerobic, nitrogen-fixing bacterium, Azotobacter vinelandii was undertaken. Immobilization was acaccomplished by adsorption onto an anionic exchange cellulose (Cellex E) with loadings as high as 10'' cells/g resin. Immobilized cell preparations were tested under both batch and continuous-flow conditions. Nitrogenase activities as high as 4200 nmol/min g resin were observed as measured by the acetylene reduction assay. Immobilized cells retained their activity for as long as 117 hr in a continuous-flow reactor. Activity loss appeared to be related to the development of a variant strain.

  5. Immobilization Technologies in Probiotic Food Production

    Science.gov (United States)

    Mitropoulou, Gregoria; Nedovic, Viktor; Goyal, Arun; Kourkoutas, Yiannis

    2013-01-01

    Various supports and immobilization/encapsulation techniques have been proposed and tested for application in functional food production. In the present review, the use of probiotic microorganisms for the production of novel foods is discussed, while the benefits and criteria of using probiotic cultures are analyzed. Subsequently, immobilization/encapsulation applications in the food industry aiming at the prolongation of cell viability are described together with an evaluation of their potential future impact, which is also highlighted and assessed. PMID:24288597

  6. Immobilization Technologies in Probiotic Food Production

    OpenAIRE

    Gregoria Mitropoulou; Viktor Nedovic; Arun Goyal; Yiannis Kourkoutas

    2013-01-01

    Various supports and immobilization/encapsulation techniques have been proposed and tested for application in functional food production. In the present review, the use of probiotic microorganisms for the production of novel foods is discussed, while the benefits and criteria of using probiotic cultures are analyzed. Subsequently, immobilization/encapsulation applications in the food industry aiming at the prolongation of cell viability are described together with an evaluation of their poten...

  7. Immobilization Technologies in Probiotic Food Production

    Directory of Open Access Journals (Sweden)

    Gregoria Mitropoulou

    2013-01-01

    Full Text Available Various supports and immobilization/encapsulation techniques have been proposed and tested for application in functional food production. In the present review, the use of probiotic microorganisms for the production of novel foods is discussed, while the benefits and criteria of using probiotic cultures are analyzed. Subsequently, immobilization/encapsulation applications in the food industry aiming at the prolongation of cell viability are described together with an evaluation of their potential future impact, which is also highlighted and assessed.

  8. Preliminary studies of radioactive wastes immobilization, using microwaves, in asphaltic matrices and elastomeric residues; Estudos preliminares da imobilizacao de rejeitos radioativos, com microondas, em matrizes asfalticas e residuos elastomericos

    Energy Technology Data Exchange (ETDEWEB)

    Caratin, Reinaldo Leonel; Araujo, Sumair Gouveia de; Landini, Liliane; Jaquier, Gilberto da Silva; Lugao, Ademar Benevolo [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)]. E-mail: rcaratin@ipen.br; sgaraujo@ipen.br; landini@usp.br; gilbertojaquier@ibest.com.br; ablugao@ipen.br

    2005-07-01

    The present work consists of preliminary studies for immobilization of radioactive waste by using monolithic solid matrices compounded by bitumen (asphalt) and production leftovers of EVA shoe soles (polymeric residues). Those matrices were obtained through high microwave energy heating aiming to reduce possible dispersion of radioactive material in the environment during the stages of intermediate storage, transportation and final disposal. The radioactive waste that was used results from the purification of thorium long made at Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP). The obtained precipitate is named Retoter (thorium residue and rare earth elements). The compounded samples of bitumen and rubber were heated by electromagnetic radiation (high microwave energy); the time was varied and the temperature was controlled. Variables such as mass percent of bitumen/rubber, dosage, microwave power, heating period and temperature were analyzed in order to get the most homogeneous formulations that might be most resistant to environmental agents. The geometry of samples is still being studied to obtain the best distribution of radioactive waste on the polymeric compound (bitumen/rubber). To prove the efficiency of the method, physics and chemistry characterizations have been initially made through assays in order to evidence properties like: porosity, density, leaching rate, resistance to radiation, resistance to aging, thermal, mechanical and structural properties. (author)

  9. Insulin action in human thighs after one-legged immobilization

    DEFF Research Database (Denmark)

    Richter, Erik; Kiens, Bente; Mizuno, M.

    1989-01-01

    Insulin action was assessed in thighs of five healthy young males who had one knee immobilized for 7 days by a splint. The splint was not worn in bed. Subjects also used crutches to prevent weight bearing of the immobilized leg. Immobilization decreased the activity of citrate synthase and 3-OH...... was significantly higher in the immobilized than in the control thigh. Seven days of one-legged immobilization causes local decreased insulin action on thigh glucose uptake and net protein degradation....

  10. Ceramification: A plutonium immobilization process

    Energy Technology Data Exchange (ETDEWEB)

    Rask, W.C. [Dept. of Energy, Golden, CO (United States); Phillips, A.G. [Rocky Flats Environmental Technology Site, Golden, CO (United States)

    1996-05-01

    This paper describes a low temperature technique for stabilizing and immobilizing actinide compounds using a combination process/storage vessel of stainless steel, in which measured amounts of actinide nitrate solutions and actinide oxides (and/or residues) are systematically treated to yield a solid article. The chemical ceramic process is based on a coating technology that produces rare earth oxide coatings for defense applications involving plutonium. The final product of this application is a solid, coherent actinide oxide with process-generated encapsulation that has long-term environmental stability. Actinide compounds can be stabilized as pure materials for ease of re-use or as intimate mixtures with additives such as rare earth oxides to increase their degree of proliferation resistance. Starting materials for the process can include nitrate solutions, powders, aggregates, sludges, incinerator ashes, and others. Agents such as cerium oxide or zirconium oxide may be added as powders or precursors to enhance the properties of the resulting solid product. Additives may be included to produce a final product suitable for use in nuclear fuel pellet production. The process is simple and reduces the time and expense for stabilizing plutonium compounds. It requires a very low equipment expenditure and can be readily implemented into existing gloveboxes. The process is easily conducted with less associated risk than proposed alternative technologies.

  11. Peptide-modified surfaces for enzyme immobilization.

    Directory of Open Access Journals (Sweden)

    Jinglin Fu

    Full Text Available BACKGROUND: Chemistry and particularly enzymology at surfaces is a topic of rapidly growing interest, both in terms of its role in biological systems and its application in biocatalysis. Existing protein immobilization approaches, including noncovalent or covalent attachments to solid supports, have difficulties in controlling protein orientation, reducing nonspecific absorption and preventing protein denaturation. New strategies for enzyme immobilization are needed that allow the precise control over orientation and position and thereby provide optimized activity. METHODOLOGY/PRINCIPAL FINDINGS: A method is presented for utilizing peptide ligands to immobilize enzymes on surfaces with improved enzyme activity and stability. The appropriate peptide ligands have been rapidly selected from high-density arrays and when desirable, the peptide sequences were further optimized by single-point variant screening to enhance both the affinity and activity of the bound enzyme. For proof of concept, the peptides that bound to β-galactosidase and optimized its activity were covalently attached to surfaces for the purpose of capturing target enzymes. Compared to conventional methods, enzymes immobilized on peptide-modified surfaces exhibited higher specific activity and stability, as well as controlled protein orientation. CONCLUSIONS/SIGNIFICANCE: A simple method for immobilizing enzymes through specific interactions with peptides anchored on surfaces has been developed. This approach will be applicable to the immobilization of a wide variety of enzymes on surfaces with optimized orientation, location and performance, and provides a potential mechanism for the patterned self-assembly of multiple enzymes on surfaces.

  12. Surface cell immobilization within perfluoroalkoxy microchannels

    Science.gov (United States)

    Stojkovič, Gorazd; Krivec, Matic; Vesel, Alenka; Marinšek, Marjan; Žnidaršič-Plazl, Polona

    2014-11-01

    Perfluoroalkoxy (PFA) is one of the most promising materials for the fabrication of cheap, solvent resistant and reusable microfluidic chips, which have been recently recognized as effective tools for biocatalytic process development. The application of biocatalysts significantly depends on efficient immobilization of enzymes or cells within the reactor enabling long-term biocatalyst use. Functionalization of PFA microchannels by 3-aminopropyltriethoxysilane (ATPES) and glutaraldehyde was used for rapid preparation of microbioreactors with surface-immobilized cells. X-ray photoelectron spectroscopy and scanning electron microscopy were used to accurately monitor individual treatment steps and to select conditions for cell immobilization. The optimized protocol for Saccharomyces cerevisiae immobilization on PFA microchannel walls comprised ethanol surface pretreatment, 4 h contacting with 10% APTES aqueous solution, 10 min treatment with 1% glutaraldehyde and 20 min contacting with cells in deionized water. The same protocol enabled also immobilization of Escherichia coli, Pseudomonas putida and Bacillus subtilis cells on PFA surface in high densities. Furthermore, the developed procedure has been proved to be very efficient also for surface immobilization of tested cells on other materials that are used for microreactor fabrication, including glass, polystyrene, poly (methyl methacrylate), polycarbonate, and two olefin-based polymers, namely Zeonor® and Topas®.

  13. Immobilization of Fast Reactor First Cycle Raffinate

    Energy Technology Data Exchange (ETDEWEB)

    Langley, K. F.; Partridge, B. A.; Wise, M.

    2003-02-26

    This paper describes the results of work to bring forward the timing for the immobilization of first cycle raffinate from reprocessing fuel from the Dounreay Prototype Fast Reactor (PFR). First cycle raffinate is the liquor which contains > 99% of the fission products separated from spent fuel during reprocessing. Approximately 203 m3 of raffinate from the reprocessing of PFR fuel is held in four tanks at the UKAEA's site at Dounreay, Scotland. Two methods of immobilization of this high level waste (HLW) have been considered: vitrification and cementation. Vitrification is the standard industry practice for the immobilization of first cycle raffinate, and many papers have been presented on this technique elsewhere. However, cementation is potentially feasible for immobilizing first cycle raffinate because the heat output is an order of magnitude lower than typical HLW from commercial reprocessing operations such as that at the Sellafield site in Cumbria, England. In fact, it falls within the upper end of the UK definition of intermediate level waste (ILW). Although the decision on which immobilization technique will be employed has yet to be made, initial development work has been undertaken to identify a suitable cementation formulation using inactive simulant of the raffinate. An approach has been made to the waste disposal company Nirex to consider the disposability of the cemented product material. The paper concentrates on the process development work that is being undertaken on cementation to inform the decision making process for selection of the immobilization method.

  14. Cell immobilization on polymer by air atmospheric pressure plasma jet treatment

    Science.gov (United States)

    Lee, Jung-Hwan; Kwon, Jae-Sung; Om, Ji-yeon; Kim, Yong-Hee; Choi, Eun-Ha; Kim, Kwang-Mahn; Kim, Kyoung-Nam

    2014-08-01

    The study of cell immobilization on delicate polymer by an air atmospheric pressure plasma jet (AAPPJ) is required for its medical application. The aim of this study was to evaluate whether AAPPJ treatment induce cell immobilization effect on delicate polymers without significant change of surface roughness by AAPPJ treatment. After surface roughness, dynamic contact angle, and chemical characteristics were investigated, the immobilization effect was evaluated with the mouse fibroblast L929 cell line. Surface roughness change was not observed (P > 0.05) in either delicate dental wax or polystyrene plate (PSP) as advancing and receding contact angles significantly decreased (P < 0.05), thanks to decreased hydrocarbon and formation of oxygen-related functional groups in treated PSP. Adherent L929 cells with elongated morphology were found in treated PSP along with the formation of immobilization markers vinculin and actin cytoskeleton. Increased PTK2 gene expression upregulated these markers on treated PSP.

  15. Development of 170 MHz Electrodeless Quartz-Crystal Microbalance Immunosensor with Nonspecifically Immobilized Receptor Proteins

    Science.gov (United States)

    Ogi, Hirotsugu; Nagai, Hironao; Fukunishi, Yuji; Yanagida, Taiji; Hirao, Masahiko; Nishiyama, Masayoshi

    2010-07-01

    Staphylococcus aureus protein A (SPA) shows high nonspecific binding affinity on a naked quartz surface, and it can be used as the receptor protein for detecting immunoglobulin G (IgG), the most important immunoglobulin. The immunosensor ability, however, significantly depends on the immobilization procedure. In this work, the effect of the nonspecific immobilization procedure on the sensor sensitivity is studied using a home-built electrodeless quartz-crystal microbalance (QCM) biosensor. The pure-shear vibration of a 9.7-µm-thick AT-cut quartz plate is excited and detected in liquids by the line antenna located outside the flow channel. SPA molecules are immobilized on the quartz surfaces, and human IgG is injected to monitor the binding reaction between SPA and IgG. This study reveals that a long (nearly 24 h) immersion procedure is required for immobilizing SPA to achieve the tight biding with the quartz surfaces.

  16. Mass and chemical changes of immobile elements in Yamaghan Occurrence, Zanjan Province, Iran

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Using mass and chemical changes, behavior of some elements have been evaluated in the study area, Yamaghan Occurrence. The techniques using immobile elements can precisely identify altered volcanic rock precursors and measure material changes. The rocks of the study area were affected by hydrothermal alteration. Testing of some compatible-incompatible and compatible-compatible immobile pairs indicates that Al2O3 is the most immobile component in the study area. It means that during the three main stages of hydrothermal alteration (phyllic, intermediate argillic and propylitic) aluminum was the most immobile and titanium was slightly immobile. Increases in mass mostly result from mineralization, silicification or carbonatization as voids and other open space fillings and may have replaced the part of glassy matrix. Mass addition has diluted the immobile elements at constant rates. Mass loss is commonly due to leaching of Si, Ca and Na2O during chloritization and sericitization. The mass loss is recognized by increased proportions of inert minerals such as chlorite and sericite. Mineralographic studies in the study area shows the existence of a supergene zone. Calcocite and covellite are considered enriched minerals. Considering this evidence and mass change results, the enrichment of copper in the circulating fluid is suspected with occasional sulfide precipitation.

  17. Green Synthesis of Wax Ester by Immobilized Lipase

    Institute of Scientific and Technical Information of China (English)

    Salina; Mat; Radzi; Noob; Mona; Mohd.Yunus; Siti; Salhah; othman; Mahiran; Basri; Mohd.Basyaruddin; Abdul; Rahman

    2007-01-01

    1 Results Enzyme catalysis is most attractive for the synthesis and modification of biologically relevant classes of fine organic compounds, which are difficult to prepare and to handle by conventional means[1]. In this study, commercial immobilized lipase from Candida antarctica (Novozym 435) was used in the preparation of fine organic compound with excellent properties and application as raw material for cosmetic formulation - oleyl palmitate. The effect of various reaction parameters were optimized c...

  18. Performing Allen's test in immobile hand: The Esmarch bandage method

    Directory of Open Access Journals (Sweden)

    Nebil Yesiloglu

    2015-12-01

    Full Text Available In this study, an alternative method of assessing hand vascular flow using a modification of Allen's test is presented. This technique may be helpful for patients who have immobile hands due to severe trauma, patients scheduled for free tissue transfer reconstruction, patients under general anesthesia in intensive care units that require serial arterial blood gas analyses, and emergency coronary by-pass candidates who decided to receive radial arterial grafts. [Hand Microsurg 2015; 4(3.000: 83-85

  19. Dye decolorization and detoxification potential of Ca-alginate beads immobilized manganese peroxidase

    OpenAIRE

    Bilal, Muhammad; Asgher, Muhammad

    2015-01-01

    Background In view of compliance with increasingly stringent environmental legislation, an eco-friendly treatment technology of industrial dyes and effluents is a major environmental challenge in the color industry. In present study, a promising and eco‐friendly entrapment approach was adopted to immobilize purified manganese peroxidase (MnP) produced from an indigenous strain of Ganoderma lucidum IBL-05 on Ca-alginate beads. The immobilized MnP was subsequently used for enhanced decolorizati...

  20. IMMOBILIZATION OF LIPASE FROM PORCINE PANCREAS ON POLY (METHYL ACRYLATE)COPOLYMERS

    Institute of Scientific and Technical Information of China (English)

    XuHuixian; LiMinqin; 等

    1994-01-01

    A series of poly(methyl acrylate) copolymers of different pore structures were synthesized and functionalized by polyethylene polyamine.The lipase from porcine pancreas was adsorbed on these polymer carriers. It was found that the proe structure and functional group were basic factors which affected the activity of immobilized lipase,The optimal conditions for adsorbing lipase were studied and the effects of pH,ionic strength and temperature on the immobilized lipase were compared with those on the dissolved lipase.

  1. Bromophenol blue discoloration using peroxidase immobilized on highly activated corncob powder

    OpenAIRE

    Júlio César Vinueza Galárraga; Andréa Francisco dos Santos; Juliana Cristina Bassan; Antonio José Goulart; Rubens Monti

    2013-01-01

    The aim of the present study was to evaluate the efficacy of peroxidase immobilized on corncob powder for the discoloration of dye. Peroxidase was extracted from soybean seed coat, followed by amination of the surface of the tertiary structure. The aminated peroxidase was immobilized on highly activated corncob powder and employed for the discoloration of bromophenol blue. Amination was performed with 10 or 50 mmol.L-1carbodiimide and 1 mol.L-1ethylenediamine. The amount of protein in the ext...

  2. Evaluation of the catalytic activity of lipases immobilized on chrysotile for esterification

    OpenAIRE

    Silva Jane E. S.; Jesus Paulo C.

    2003-01-01

    In the present work, the ester synthesis in organic media catalyzed by lipases immobilized on chrysotile was studied. Lipases of different sources (Mucor javanicus, Pseudomonas cepacia, Rhizopus oryzae, Aspergillus niger and Candida rugosa) were immobilized on chrysotile, an inexpensive magnesium silicate, and used for esterification of hexanoic, octanoic and lauric acid with methanol, ethanol, 1-butanol and 1-octanol at 25ºC in hexane as solvent. The best results were obtained with Mucor jav...

  3. 固定化厌氧颗粒污泥的制备及其产甲烷活性研究%Study on Preparation of Immobilized Anaerobic Granular Sludge and Its Methane Production Activity

    Institute of Scientific and Technical Information of China (English)

    蒋新龙; 邵铭东; 蒋益花

    2015-01-01

    Treated anaerobic granular sludge with beer wastewater as the bacterial species, sodium alginate as embedding agent and calcium chloride as curing agent, immobilized anaerobic granular sludge was prepared. Taking the activity of methane production as constant index, by changing the immobilization time, chloride calcium concentration and concentration of sodium alginate, anaerobic granular sludge immobilization condition was optimizated. The optimum immobilization conditions were as follows:1% sodium alginate, 1. 5% CaCl2 , 10 min immobilization time. The activity and stability of methane production in the granular sludge after immobilization treatment were higher than those in not fixed treatment sludge.%以啤酒废水处理厌氧颗粒污泥为菌种,海藻酸钠为包埋剂,氯化钙为固化剂,制备固定化厌氧颗粒污泥。以产甲烷活性为恒量指标,通过改变海藻酸钠浓度、氯化钙浓度以及固定化时间,进行厌氧颗粒污泥固定化条件优化。最适固定化条件为:1%海藻酸钠,1.5% CaCl2浓度,10 min固定化时间。经固定化处理后的颗粒污泥,其产甲烷活性及稳定性均高于未经过固定化处理的颗粒污泥。

  4. 单分散磁性纳米粒子固定化猪胰脂肪酶的研究%STUDY ON LIPASE IMMOBILIZATION ON MONODISPERSE MAGNETIC NANOPARTICLES

    Institute of Scientific and Technical Information of China (English)

    朱浩; 侯晨; 李彦锋

    2011-01-01

    A simple, effective, green and economic approach of lipase immobilization is provided in this article. Single-crystal,hydrophilic, biocompatible Fe3O4magnetic nanoparticles as good carriers were prepared via a solvothermal reduction method. Microsphere diameters were observed to be about 200 nm by transmission electron microscopy ( TEM ). Superior monodispersity was demonstrated, and saturation magnetization was found to be 83.7 emug-1 . The resulting products were modified directly with γ-aminopropyltriethoxysilane (APTS). Porcine pancreas lipase ( PPL) was covalently immobilized on the obtained particles using glutaraldehyde as a coupling reagent. The enzymatic activities of free and immobilized PPL were measured by titration of fatty acid which came from the hydrolysis of olive oil and the amount of protein was determined by the Bradford method using bovine serum albumin ( BSA) as a standard. The factors related with the activity of the immobilized lipase on prior carriers, such as the pH value of the immobilized reaction, the concentration of glutaraldehyde and the amount of enzyme were investigated. The immobilized lipase exhibited excellent thermal stability and reusability in comparison with free enzyme. High activity recovery (54. 8% ) of the immobilized lipase was achieved and the amount of protein was up to 120 mg/g. This immobilized lipase can be reused 10 times with the enzymatic activity remained above 90% .%借助溶热法制备了一种亲水及生物相容良好的Fe3O4磁性纳米粒子,用γ-氨丙基三乙氧基硅烷直接对所得磁性粒子表面改性,然后用戊二醛偶联法制得了固定化猪胰脂肪酶.表征研究显示,所得磁性粒子粒径约200 nm,具有良好的单分散性和磁响应性.考察了戊二醛浓度、给酶量和反应时间对脂肪酶固定化过程的影响,并通过游离酶与固定化酶的比较研究了所得固定化酶的性质.所得固定化猪胰脂肪酶呈现出优异的热稳定性

  5. Laccase immobilized on mesoporous SiO2 and its use for degradation of chlorophenol pesticides

    Science.gov (United States)

    Yang, Yuxiang; Xu, Yong; Yang, Yiwen; Yang, Huan; Yuan, Hongmin; Huang, Yan; Liu, Xiangnong

    2016-10-01

    In this paper, mesoporous silica with large specific surface area was used to immobilize laccase by the glutaraldehyde cross-linking method, and after screening and optimization experiments, the best enzyme immobilization process conditions were found (25°C, pH 5.4, 4% glutaraldehyde and 0.2 g/L laccase, treatment time 6 h). After that, the removal and degradation ratio of 2,4-dichlorophenol (abbreviated as DCP) under different conditions were also studied. After the degradation process was performed for 6 h at 30°C, pH 5.4, and DCP initial concentration of 50 mg/L in the presence of 0.1 g of immobilized laccase, the removal ratio and the degradation ratio were 42.28 and 15.93%, respectively. Compared with free laccase, the reusability of immobilized laccase is significantly improved.

  6. Developing an Efficient and General Strategy for Immobilization of Small Molecules onto Microarrays Using Isocyanate Chemistry

    Directory of Open Access Journals (Sweden)

    Chenggang Zhu

    2016-03-01

    Full Text Available Small-molecule microarray (SMM is an effective platform for identifying lead compounds from large collections of small molecules in drug discovery, and efficient immobilization of molecular compounds is a pre-requisite for the success of such a platform. On an isocyanate functionalized surface, we studied the dependence of immobilization efficiency on chemical residues on molecular compounds, terminal residues on isocyanate functionalized surface, lengths of spacer molecules, and post-printing treatment conditions, and we identified a set of optimized conditions that enable us to immobilize small molecules with significantly improved efficiencies, particularly for those molecules with carboxylic acid residues that are known to have low isocyanate reactivity. We fabricated microarrays of 3375 bioactive compounds on isocyanate functionalized glass slides under these optimized conditions and confirmed that immobilization percentage is over 73%.

  7. Developing an Efficient and General Strategy for Immobilization of Small Molecules onto Microarrays Using Isocyanate Chemistry.

    Science.gov (United States)

    Zhu, Chenggang; Zhu, Xiangdong; Landry, James P; Cui, Zhaomeng; Li, Quanfu; Dang, Yongjun; Mi, Lan; Zheng, Fengyun; Fei, Yiyan

    2016-03-16

    Small-molecule microarray (SMM) is an effective platform for identifying lead compounds from large collections of small molecules in drug discovery, and efficient immobilization of molecular compounds is a pre-requisite for the success of such a platform. On an isocyanate functionalized surface, we studied the dependence of immobilization efficiency on chemical residues on molecular compounds, terminal residues on isocyanate functionalized surface, lengths of spacer molecules, and post-printing treatment conditions, and we identified a set of optimized conditions that enable us to immobilize small molecules with significantly improved efficiencies, particularly for those molecules with carboxylic acid residues that are known to have low isocyanate reactivity. We fabricated microarrays of 3375 bioactive compounds on isocyanate functionalized glass slides under these optimized conditions and confirmed that immobilization percentage is over 73%.

  8. Short-term immobilization and recovery affect skeletal muscle but not collagen tissue turnover in humans

    DEFF Research Database (Denmark)

    Christensen, Britt; Dyrberg, Eva; Aagaard, Per

    2008-01-01

    of 6% (5,413 to 5,077 mm(2)) in cross-sectional area (CSA) of the triceps surae muscles and a mean decrease of 9% (261 to 238 N.m) in strength of the immobilized calf muscles. Two weeks of recovery resulted in a 6% increased in CSA (to 5,367 mm(2)), whereas strength remained suppressed (240 N...... muscle size and strength, while tendon size and collagen turnover were unchanged. While recovery resulted in an increase in muscle size, strength was unchanged. No significant difference in tendon size could be detected between the two legs after 2 wk of recovery, although collagen synthesis......Not much is known about the effects of immobilization and subsequent recovery on tendon connective tissue. In the present study, healthy young men had their nondominant leg immobilized for a 2-wk period, followed by a recovery period of the same length. Immobilization resulted in a mean decrease...

  9. Production of gluconic acid by Aspergillus niger immobilized on polyurethane foam.

    Science.gov (United States)

    Vassilev, N B; Vassileva, M C; Spassova, D I

    1993-06-01

    Production of gluconic acid by cells of Aspergillus niger immobilized on polyurethane foam was studied in repeated-batch shake-flask and bubble-column fermentations. For passive immobilization, various amounts of polyurethane foam and spore suspension were tested in order to obtain a suitable combination for optimal concentration of immobilized biomass. Immobilized cells were successfully reused with higher levels of product formation being maintained for longer period (65-70 h) than free cells. The highest gluconic acid concentration of about 143 g l-1 was reached on hydrol-based production medium with 0.3-cm3 foam cubes in the bubble column, where the effect of more suitable aeration and particle volume: medium volume ratio scheme was also investigated.

  10. Immobilization of a Pleurotus ostreatus laccase mixture on perlite and its application to dye decolourisation.

    Science.gov (United States)

    Pezzella, Cinzia; Russo, Maria Elena; Marzocchella, Antonio; Salatino, Piero; Sannia, Giovanni

    2014-01-01

    In the present study, a crude laccase preparation from Pleurotus ostreatus was successfully immobilized on perlite, a cheap porous silica material, and tested for Remazol Brilliant Blue R (RBBR) decolourisation in a fluidized bed recycle reactor. Results showed that RBBR decolourisation is mainly due to enzyme action despite the occurrence of dye adsorption-related enzyme inhibition. Fine tuning of immobilization conditions allowed balancing the immobilization yield and the resulting rate of decolourisation, with the adsorption capacity of the solid biocatalyst. In the continuous lab scale reactor, a maximum conversion degree of 56.1% was achieved at reactor space-time of 4.2 h. Stability and catalytic parameters of the immobilized laccases were also assessed in comparison with the soluble counterparts, revealing an increase in stability, despite a reduction of the catalytic performances. Both effects are most likely ascribable to the occurrence of multipoint attachment phenomena.

  11. Immobilization of a Pleurotus ostreatus Laccase Mixture on Perlite and Its Application to Dye Decolourisation

    Directory of Open Access Journals (Sweden)

    Cinzia Pezzella

    2014-01-01

    Full Text Available In the present study, a crude laccase preparation from Pleurotus ostreatus was successfully immobilized on perlite, a cheap porous silica material, and tested for Remazol Brilliant Blue R (RBBR decolourisation in a fluidized bed recycle reactor. Results showed that RBBR decolourisation is mainly due to enzyme action despite the occurrence of dye adsorption-related enzyme inhibition. Fine tuning of immobilization conditions allowed balancing the immobilization yield and the resulting rate of decolourisation, with the adsorption capacity of the solid biocatalyst. In the continuous lab scale reactor, a maximum conversion degree of 56.1% was achieved at reactor space-time of 4.2 h. Stability and catalytic parameters of the immobilized laccases were also assessed in comparison with the soluble counterparts, revealing an increase in stability, despite a reduction of the catalytic performances. Both effects are most likely ascribable to the occurrence of multipoint attachment phenomena.

  12. Developing an Efficient and General Strategy for Immobilization of Small Molecules onto Microarrays Using Isocyanate Chemistry

    Science.gov (United States)

    Zhu, Chenggang; Zhu, Xiangdong; Landry, James P.; Cui, Zhaomeng; Li, Quanfu; Dang, Yongjun; Mi, Lan; Zheng, Fengyun; Fei, Yiyan

    2016-01-01

    Small-molecule microarray (SMM) is an effective platform for identifying lead compounds from large collections of small molecules in drug discovery, and efficient immobilization of molecular compounds is a pre-requisite for the success of such a platform. On an isocyanate functionalized surface, we studied the dependence of immobilization efficiency on chemical residues on molecular compounds, terminal residues on isocyanate functionalized surface, lengths of spacer molecules, and post-printing treatment conditions, and we identified a set of optimized conditions that enable us to immobilize small molecules with significantly improved efficiencies, particularly for those molecules with carboxylic acid residues that are known to have low isocyanate reactivity. We fabricated microarrays of 3375 bioactive compounds on isocyanate functionalized glass slides under these optimized conditions and confirmed that immobilization percentage is over 73%. PMID:26999137

  13. Laccase immobilized onto poly(GMA-MAA) microspheres for p-benzenediol removal from wastewater.

    Science.gov (United States)

    Li, Congcong; Lou, Yuhong; Wan, Yazhen; Wang, Weiqiang; Yao, Jilei; Zhang, Bing

    2013-01-01

    Enzymes have already been extensively applied to degrade various organic pollutants in industrial wastewater, and how to improve the stability and reusability of the enzymes is critical to their practical application. In this study, poly(glycidyl methacrylate-methacrylic acid), poly(GMA-MAA), microspheres were prepared by suspension polymerization, and were used as a new support to immobilize Trametes versicolor laccase. The maximum loading capacity to immobilize enzyme reached as high as 44.78 mg protein/g support. The stability and reusability of laccase were greatly improved after immobilization on the microspheres. While the immobilized laccase was used as catalyst to remove p-benzenediol from wastewater, the removal efficiency reached 88.5%.

  14. Reversible immobilization of laccase onto metal-ion-chelated magnetic microspheres for bisphenol A removal.

    Science.gov (United States)

    Lin, Jiahong; Liu, Yingju; Chen, Shi; Le, Xueyi; Zhou, Xiaohua; Zhao, Zhiyong; Ou, Yiyi; Yang, Jianhua

    2016-03-01

    Increasing attention has been given to nanobiocatalysis for commercial applications. In this study, laccase was reversibly immobilized onto Cu(ΙΙ)- and Mn(ΙΙ)-chelated magnetic microspheres and successfully applied to remove bisphenol A (BPA) from water. The results indicated that the loading of laccase onto the metal-ion-chelated magnetic microspheres was approximately 100mg/g. After five successive adsorption-desorption cycles, the laccase adsorption capacities did not change. In comparison with free laccase, the thermal and storage stabilities of immobilized laccase were significantly improved. Immobilized laccase exhibited a high removal efficiency for BPA under the combined actions of biodegradation and adsorption. Greater than 85% of BPA was removed under optimum conditions. The effects of various factors on the BPA removal efficiency of immobilized laccase were analysed. The results showed that metal-ion-chelated magnetic microspheres have great potential for industrial applications. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Neuropeptide Y and leptin receptor expression in the hypothalamus of rats with chronic immobilization stress

    Institute of Scientific and Technical Information of China (English)

    Shaoxian Wang; Jiaxu Chen; Guangxin Yue; Minghua Bai; Meijing Kou; Zhongye Jin

    2013-01-01

    In this study, Sprague-Dawley rats were immobilized to a frame for 3 hours a day for 21 days to establish a model of chronic immobilization stress. The body weight and food intake of rats subjected to chronic immobilization stress were significantly decreased compared with the control group. Dual-labeling immunofluorescence revealed that the expression of leptin receptor and the co-localization coeffient in these leptic receptor neurons in the arcuate nucleus of the hypothalamus were both upregulated, while the number of neuropeptide Y neurons was decreased. Chronic immobilization stress induced high expression of leptin receptor in the arcuate nucleus and suppressed the synthesis and secretion of neuropeptide Y, thereby disrupting the pathways in the arcuate nucleus that regulate feeding behavior, resulting in diminished food intake and reduced body weight.

  16. Catechol Removal from Aqueous Media Using Laccase Immobilized in Different Macro- and Microreactor Systems.

    Science.gov (United States)

    Tušek, Ana Jurinjak; Šalić, Anita; Zelić, Bruno

    2017-01-23

    Laccase belongs to the group of enzymes that are capable to catalyze the oxidation of phenols. Since the water is only by-product in laccase-catalyzed phenol oxidations, it is ideally "green" enzyme with many possible applications in different industrial processes. To make the oxidation process more sustainable in terms of biocatalyst consumption, immobilization of the enzyme is implemented in to the processes. Additionally, when developing a process, choice of a reactor type plays a significant role in the total outcome.In this study, the use of immobilized laccase from Trametes versicolor for biocatalytic catechol oxidation was explored. Two different methods of immobilization were performed and compared using five different reactor types. In order to compare different systems used for catechol oxidation, biocatalyst turnover number and turnover frequency were calculated. With low consumption of the enzyme and good efficiency, obtained results go in favor of microreactors with enzyme covalently immobilized on the microchannel surface.

  17. IMMOBILIZATION OF GLUCOSE OXIDASE AND CELLULASE BY CHITOSAN-POLYACRYLIC ACID COMPLEX

    Institute of Scientific and Technical Information of China (English)

    WANG Lingzhi; JIANG Yingyan; ZHANG Changde; HUANG Dexiu

    1990-01-01

    This study is concerned with chitosan-polyacrylic acid complex as a carrier to immobilize glucose oxidase (GOD) and cellulase. The optimum temperature of the immobilized GOD (IG) was determined to be 60 ℃ which is higher than that of the native GOD about 40 ℃ . The optimum temperature of the immobilized cellulase (IC) was determined to be about 30 ℃ higher than that of native cellulase. Both of the optimum pH of IG and IC shifted one pH unit to acid. Immobilized enzyme may be used in more wide pH range. Their storage life are much longer compared with their native states. Both of them can be reused at least 12 times.

  18. Characterization of immobilization methods of antiviral antibodies in serum for electrochemical biosensors

    Energy Technology Data Exchange (ETDEWEB)

    Huy, Tran Quang, E-mail: huytq@nihe.org.vn [National Institute of Hygiene and Epidemiology (NIHE), No1 Yersin St., Hanoi (Viet Nam); International Training Institute for Materials Science (ITIMS), Hanoi University of Science and Technology (HUST), No1 Dai Co Viet, Hanoi (Viet Nam); Hanh, Nguyen Thi Hong; Van Chung, Pham; Anh, Dang Duc; Nga, Phan Thi [National Institute of Hygiene and Epidemiology (NIHE), No1 Yersin St., Hanoi (Viet Nam); Tuan, Mai Anh, E-mail: tuanma-itims@mail.hut.edu.vn [International Training Institute for Materials Science (ITIMS), Hanoi University of Science and Technology (HUST), No1 Dai Co Viet, Hanoi (Viet Nam)

    2011-06-01

    In this paper, we describes different methods to immobilize Japanese encephalitis virus (JEV) antibodies in human serum onto the interdigitated surface of a microelectrode sensor for optimizing electrochemical detection: (1) direct covalent binding to the silanized surface, (2) binding to the silanized surface via a cross-linker of glutaraldehyde (GA), (3) binding to glutaraldehyde/silanized surface via goat anti-human IgG polyclonal antibody and (4) binding to glutaraldehyde/silanized surface via protein A (PrA). Field emission scanning electron microscopy, Fourier transform infrared spectrometry, and fluorescence microscopy are used to verify the characteristics of antibodies on the interdigitated surface after the serum antibodies immobilization. The analyzed results indicate that the use of protein A is an effective choice for immobilization and orientation of antibodies in serum for electrochemical biosensors. This study provides an advantageous immobilization method of serum containing antiviral antibodies to develop electrochemical biosensors for preliminary screening of viruses in clinical samples from outbreaks.

  19. Interaction of Rheumatoid Factor with Immobilized ss-DNA

    Institute of Scientific and Technical Information of China (English)

    WANG Lian-yong; LU Jing; YU Yao-ting

    2004-01-01

    Rheumatoid factors(RFs) are the characteristic autoantibodies of rheumatoid arthritis. Recent researches in our laboratory showed that the immobilized single-stranded DNA(ss-DNA) immunoadsorbent can selectively remove RFs from the serum of patients. In the present paper are studied the modification of argininine, tryptophan, lysine residues and carboxyl terminus of IgGRF, which was separated from patients′ serum, with 1,2-cyclohexanedione(CHD), N-bromosuccinimide(NBS), pyridoxal 5′-phosphate(PP) and 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide(EDC) respectively, and their effects on the adsorption capacity of the immobilized ss-DNA immunoadsorbent for IgGRF. After the specific modification, the corresponding adsorption capacities of the adsorbents were changed from 48%, 46%, 44% and 54% to 84%, 14%, 21% and 81%, respectively. These results indicate that the electrostatic or ionic-bonding is essential for the interaction between ss-DNA and IgGRF.

  20. Hydrogen production from biodiesel byproduct by immobilized Enterobacter aerogenes.

    Science.gov (United States)

    Han, Jinmi; Lee, Dohoon; Cho, Jinku; Lee, Jeewon; Kim, Sangyong

    2012-01-01

    The recent rapid growth of the biodiesel industry has generated a significant amount of glycerol as a byproduct. As a result, the price of glycerol is currently relatively low, making it an attractive starting material for the production of chemicals with higher values. Crude glycerol can be directly converted through microbial fermentation into various chemicals such as hydrogen. In this study, we optimized immobilization of a facultative hydrogen producing microorganism, Enterobacter aerogenes, with the goal of developing biocatalysts that was appropriate for the continuous hydrogen production from glycerol. Several carriers were tested and agar was found to be the most effective. In addition, it was clearly shown that variables such as the carrier content and cell loading should be controlled for the immobilization of biocatalysts with high hydrogen productivity, stability, and reusability. After optimization of these variables, we were able to obtain reusable biocatalysts that could directly convert the byproduct stream from biodiesel processes into hydrogen in continuous processes.

  1. Water equivalent thickness analysis of immobilization devices for clinical implementation in proton therapy.

    Science.gov (United States)

    Wroe, A J; Ghebremedhin, A; Gordon, I R; Schulte, R W; Slater, J D

    2014-10-01

    Immobilization devices can impact not only the inter- and intra-fraction motion of the patient, but also the range uncertainty of the treatment beam in proton therapy. In order to limit additional range uncertainty, the water equivalent thickness (WET) of the immobilization device needs to be well known and accurately reflected in the calculations by the treatment planning system (TPS). The method presented here focusses on the use of a nozzle-mounted variable range shifter and precision-machined polystyrene blocks of known WET to evaluate commercial immobilization devices prior to clinical implementation. CT studies were also completed to evaluate the internal uniformity of the immobilization devices under study. Mul- tiple inserts of the kVue platform (Qfix Systems, Avondale, PA) were evaluated as part of this study. The results indicate that the inserts are largely interchangeable across a given design type and that the measured WET values agree with those generated by the TPS with a maxi- mum difference less than 1 mm. The WET of the devices, as determined by the TPS, was not impacted by CT beam hardening normally experienced during clinical use. The reproduc- ibility of the WET method was also determined to be better than ±0.02 mm. In conclusion, the testing of immobilization prior to implementation in proton therapy is essential in order to ascertain their impact on the proton treatment and the methodology described here can also be applied to other immobilization systems.

  2. Immobilization in External Rotation Versus Internal Rotation After Primary Anterior Shoulder Dislocation: A Meta-analysis of Randomized Controlled Trials.

    Science.gov (United States)

    Whelan, Daniel B; Kletke, Stephanie N; Schemitsch, Geoffrey; Chahal, Jaskarndip

    2016-02-01

    The recurrence rate after primary anterior shoulder dislocation is high, especially in young, active individuals. Recent studies have suggested external rotation immobilization as a method to reduce the rate of recurrent shoulder dislocation in comparison to traditional sling immobilization. To assess and summarize evidence from randomized controlled trials on the effect of internal rotation versus external rotation immobilization on the rate of recurrence after primary anterior shoulder dislocation. Meta-analysis. PubMed, MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, and abstracts from recent proceedings were searched for eligible studies. Two reviewers selected studies for inclusion, assessed methodological quality, and extracted data. Six randomized controlled trials (632 patients) were included in this review. Demographic and prognostic variables measured at baseline were similar in the pooled groups. The average age was 30.1 years in the pooled external rotation group and 30.3 years in the pooled internal rotation group. Two studies found that external rotation immobilization reduced the rate of recurrence after initial anterior shoulder dislocation compared with conventional internal rotation immobilization, whereas 4 studies failed to find a significant difference between the 2 groups. This meta-analysis suggested no overall significant difference in the rate of recurrence among patients treated with internal rotation versus external rotation immobilization (risk ratio, 0.69; 95% CI, 0.42-1.14; P = .15). There was no significant difference in the rate of compliance between internal and external rotation immobilization (P = .43). The Western Ontario Shoulder Instability Index scores were pooled across 3 studies, and there was no significant difference between the 2 groups (P = .54). Immobilization in external rotation is not significantly more effective in reducing the recurrence rate after primary anterior shoulder dislocation than

  3. 硅藻土基纳米TiO2降解甲醛的实验研究%Experimental study on the formaldehyde degradation by nano,TiO2 immobilized on diatomite

    Institute of Scientific and Technical Information of China (English)

    俞成林; 权红恩; 康勇

    2012-01-01

    The characteristics of the diatomite powder and the nano-TiO2 immobilized on diatomite for formaldehyde adsorption were compared. The formaldehyde degradation of the nano-TiO2 immobilized on diatomite by the dosage of 62.5 g·m -2 was studied under the condition of varying original formaldehyde concentration, reaction temperature, light intensity and relative atmosphere humidity in the reactor, The results showed that the diatomite powder can only adsorb formaldehyde but the nano-TiO2 immobilized on diatomite can adsorb and degrade formaldehyde continuously. The degradation time was long for high formaldehyde original concentration. The degradation time of formaldehyde with original concentration of 6.0 × 10 -3 mg·L^-1 were 150 h, whereas only 14 h and 32 h for the original concentration of 2.0 × 10- 3 mg-L^-1 and 4.0 ×10 ^-3 mg·L^-1 respectively when the degradation ratio above 99%. The higher reaction temperature was, the shorter time of degrading formaldehyde. 50 h was needed for the complete photocatalyst oxidation of formaldehyde with original concentration 2.0 × 10 -3 mg· L-1 under reaction temperature 15 ℃, but only 12 h under 45 ℃. Light was the key driving power of the nano-TiO2 immobilized on diatomite degrading formaldehyde. The degradation time of formaldehyde of 2.0× 10-3 mg. L-1 was 14 h when the light intensity was 8100 Ix, but formaldehyde could hardly be degraded when the light intensity was 0 lm m -2. The rate of formaldehyde degradation by the photocatalyst was also enhanced by the relative humidity in the reactor. The formaldehyde degradation time from 2.0 × 10 - 3 mg. L- 1 to 3.72× 10 -5 mg.L-1 was 14 h under the relative humidity of 50% , but to 1.0 × 10 -5 mg.L-1 under the relative humidity of 80%.%对比研究了硅藻土和硅藻土基纳米二氧化钛光催化剂对甲醛的吸附降解特点.通过改变反应器内甲醛的初始浓度、反应温度、光照强度和相对湿度,研究了涂覆量为62.5g·m-2

  4. Enhanced accumulation of starch and total carbohydrates in alginate-immobilized Chlorella spp. induced by Azospirillum brasilense: II. Heterotrophic conditions.

    Science.gov (United States)

    Choix, Francisco J; de-Bashan, Luz E; Bashan, Yoav

    2012-10-10

    The effect of the bacterium Azospirillum brasilense jointly immobilized with Chlorella vulgaris or C. sorokiniana in alginate beads on total carbohydrates and starch was studied under dark and heterotrophic conditions for 144 h in synthetic growth medium supplemented with either d-glucose or Na-acetate as carbon sources. In all treatments, enhanced total carbohydrates and starch content per culture and per cell was obtained after 24h; only jointly immobilized C. vulgaris growing on d-glucose significantly increased total carbohydrates and starch content after 96 h. Enhanced accumulation of carbohydrate and starch under jointly immobilized conditions was variable with time of sampling and substrate used. Similar results occurred when the microalgae was immobilized alone. In both microalgae growing on either carbon sources, the bacterium promoted accumulation of carbohydrates and starch; when the microalgae were immobilized alone, they used the carbon sources for cell multiplication. In jointly immobilized conditions with Chlorella spp., affinity to carbon source and volumetric productivity and yield were higher than when Chlorella spp. were immobilized alone; however, the growth rate was higher in microalgae immobilized alone. This study demonstrates that under heterotrophic conditions, A. brasilense promotes the accumulation of carbohydrates in two strains Chlorella spp. under certain time-substrate combinations, producing mainly starch. As such, this bacterium is a biological factor that can change the composition of compounds in microalgae in dark, heterotrophic conditions.

  5. Immobilization and catalytic properties of lipase on chitosan for hydrolysis and esterification reactions

    Directory of Open Access Journals (Sweden)

    Pereira E.B.

    2003-01-01

    Full Text Available The objective of this study was to evaluate the immobilization of lipase on a chitosan support by physical adsorption, aiming at its application in hydrolytic and synthetic reactions. Two types of chitosan (flakes and porous were used for immobilizing lipase from a microbial source (Candida rugosa and animal cells (porcine pancreas. The best results for recovery of total activity after immobilization were obtained for microbial lipase and porous chitosan beads. This set was selected for further immobilization studies, including full characterization of the immobilized derivative in aqueous and organic media. In aqueous medium, the operational and thermal stabilities of this preparation were quantified. In organic medium, the direct synthesis of n-butyl butyrate in organic solvent was chosen as a model reaction. The influence of several parameters, such as temperature, initial butyric acid concentration and amount of enzyme in the reaction system, was analyzed. Production of n-butyl butyrate was optimized and an ester yield response equation was obtained, making it possible to predict ester yields from known values of the three main factors. Use of this immobilized preparation was extended to the direct esterification of a large range of carboxylic acids (from C2 to C12 with a variety of alcohols (from C2 to C10.

  6. "Fish-in-net", a novel method for cell immobilization of Zymomonas mobilis.

    Directory of Open Access Journals (Sweden)

    Xuedun Niu

    Full Text Available BACKGROUND: Inorganic mesoporous materials exhibit good biocompatibility and hydrothermal stability for cell immobilization. However, it is difficult to encapsulate living cells under mild conditions, and new strategies for cell immobilization are needed. We designed a "fish-in-net" approach for encapsulation of enzymes in ordered mesoporous silica under mild conditions. The main objective of this study is to demonstrate the potential of this approach in immobilization of living cells. METHODOLOGY/PRINCIPAL FINDINGS: Zymomonas mobilis cells were encapsulated in mesoporous silica-based materials under mild conditions by using a "fish-in-net" approach. During the encapsulation process, polyethyleneglycol was used as an additive to improve the immobilization efficiency. After encapsulation, the pore size, morphology and other features were characterized by various methods, including scanning electron microscopy, nitrogen adsorption-desorption analysis, transmission electron microscopy, fourier transform infrared spectroscopy, and elemental analysis. Furthermore, the capacity of ethanol production by immobilized Zymomonas mobilis and free Zymomonas mobilis was compared. CONCLUSIONS/SIGNIFICANCE: In this study, Zymomonas mobilis cells were successfully encapsulated in mesoporous silica-based materials under mild conditions by the "fish-in-net" approach. Encapsulated cells could perform normal metabolism and exhibited excellent reusability. The results presented here illustrate the enormous potential of the "fish-in-net" approach for immobilization of living cells.

  7. Removal of endocrine disrupting compounds from wastewater by microalgae co-immobilized in alginate beads.

    Science.gov (United States)

    Solé, Alba; Matamoros, Víctor

    2016-12-01

    Microalgae systems have been found to be efficient for removing microcontaminants from wastewater effluents, but the effectiveness of immobilized microalgae for removing endocrine disrupting compounds (EDCs) has not yet been addressed. This paper assesses the effect of free and immobilized microalgae on removal efficiency for 6 EDCs by mixing them in 2.5 L reactors with treated wastewater. The experimental design also included control reactors without microalgae. After 10 days of incubation, 64 and 89% of the NH4-N and 90 and 96% of total phosphorous (TP) had been eliminated in the free microalgae and immobilized microalgae reactors, respectively, while the control reactors eliminated only 40% and 70% of the NH4-N and TP, respectively. Both the free and immobilized microalgae reactors were able to remove up to 80% of most of the studied EDCs within 10 days of incubation. Free microalgae were found to increase the kinetic removal rate for bisphenol A, 17-α-ethinylestradiol, and 4-octylphenol (25%, 159%, and 41%, respectively). Immobilizing the microalgae in alginate beads additionally enhanced the kinetic removal rate for bisphenol AF, bisphenol F, and 2,4-dichlorophenol. This study shows that the use of co-immobilized microalgae-based wastewater treatment systems increases the removal efficiency for nutrients and some EDCs from wastewater effluents. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Factors affecting the immobilization of fungal biomass on CNT as a biosorbent for textile dyes removal

    Science.gov (United States)

    Adebayo Bello, Ibrahim; Kabbashi, Nassereldeen A.; Zahangir Alam, Md; Alkhatib, Ma'an F.; Nabilah Murad, Fatin

    2017-07-01

    Effluents from dye and textile industries are highly contaminated and toxic to the environment. High concentration of non-biodegradable compounds contributes to increased biochemical oxygen demand (BOD) and chemical oxygen demand (COD) of the wastewater bodies. Dyes found in wastewater from textile industries are carcinogenic, mutagenic or teratogenic. Biological processes involving certain bacteria, fungi and activated carbon have been employed in treating wastewater. These methods are either inefficient or ineffective. These complexities necessitates search for new approaches that will offset all the shortcomings of the present solutions to the challenges faced with textile wastewater management. This study produced a new biosorbent by the immobilization of fungal biomass on carbon nanotubes. The new biosorbent is called “carbon nanotubes immobilized biomass (CNTIB)” which was produced by immobilization technique. A potential fungal strain, Aspergillus niger was selected on the basis of biomass production. It was found out in this studies that fungal biomass were better produced in acidic medium. Aspergillus niger was immobilized on carbon nanotubes. One-factor-at-a time (OFAT) was employed to determine the effect of different factors on the immobilization of fungal biomass on carbon nanotubes and optimum levels at which the three selected parameters (pH, culture time and agitation rate) would perform. Findings from OFAT showed that the optimum conditions for immobilization are a pH of 5, agitation rate of 150rpm and a culture time of 5 days.

  9. Immobilization of thermolysin to polyamide nonwoven materials.

    Science.gov (United States)

    Moeschel, Klaus; Nouaimi, Meryem; Steinbrenner, Christa; Bisswanger, Hans

    2003-04-20

    In the last few years, an increasing number of biotechnological techniques have been applied to the restoration and conservation of works of art, paintings, old maps, and papers or books. Enzymes can solve problems that give restorers difficulties, although for many applications it is not possible to use soluble enzymes; therefore, it is necessary to look for suitable carriers for immobilization. Different methods for covalent immobilization of enzymes to polyamide nonwovens were tested, using thermolysin as an example. Two distinct strategies were pursued: (1). controlled, partial hydrolysis of the polymer and subsequent binding of the enzyme to the released amino and carboxy groups; and (2). attachment of reactive groups directly to the polyamide without disintegrating the polymeric structure (O-alkylation). Different spacers were used for covalent fixation of the enzyme in both cases. The enzyme was fixed to the released amino groups by glutaraldehyde, either with or without a spacer. Either way, active enzyme could be immobilized to the matrix. However, intense treatment caused severe damage to the stability of the nonwoven fabric, and reduced the mechanical strength. Conditions were investigated to conserve the nonwoven fabric structure while obtaining near-maximum immobilized enzyme activity. Immobilization of the enzyme to the released carboxy group after acid hydrolysis was performed using dicyclohexylcarbodiimide. In comparison to the enzyme bound via the amino group, the yield of immobilized enzyme activity was slightly lower when benzidine was taken as spacer and still lower with a 1,6-hexanediamine spacer. O-alkylation performed with dimethylsulfate caused severe damage to the nonwoven fabric structure. Considerably better results were obtained with triethyloxonium tetrafluoroborate. As the spacers 1,6-hexanediamine and adipic acid dihydrazide were used, activation for immobilizing thermolysin was performed with glutaraldehyde, adipimidate, and azide

  10. Biomolecule immobilization techniques for bioactive paper fabrication.

    Science.gov (United States)

    Kong, Fanzhi; Hu, Yim Fun

    2012-04-01

    Research into paper-based sensors or functional materials that can perform analytical functions with active recognition capabilities is rapidly expanding, and significant research effort has been made into the design and fabrication of bioactive paper at the biosensor level to detect potential health hazards. A key step in the fabrication of bioactive paper is the design of the experimental and operational procedures for the immobilization of biomolecules such as antibodies, enzymes, phages, cells, proteins, synthetic polymers and DNA aptamers on a suitably prepared paper membrane. The immobilization methods are concisely categorized into physical absorption, bioactive ink entrapment, bioaffinity attachment and covalent chemical bonding immobilization. Each method has individual immobilization characteristics. Although every biomolecule-paper combination has to be optimized before use, the bioactive ink entrapment method is the most commonly used approach owing to its general applicability and biocompatibility. Currently, there are four common applications of bioactive paper: (1) paper-based bioassay or paper-based analytical devices for sample conditioning; (2) counterfeiting and countertempering in the packaging and construction industries; (3) pathogen detection for food and water quality monitoring; and (4) deactivation of pathogenic bacteria using antimicrobial paper. This article reviews and compares the different biomolecule immobilization techniques and discusses current trends. Current, emerging and future applications of bioactive paper are also discussed.

  11. Liver alcohol dehydrogenase immobilized on polyvinylidene difluoride.

    Science.gov (United States)

    Roig, M G; Bello, J F; Moreno de Vega, M A; Cachaza, J M; Kennedy, J F

    1990-01-01

    A physical method for immobilization of liver alcohol dehydrogenase (ADH) by hydrophobic adsorption onto a supporting membrane of polyvinylidene difluoride (PVDF) was performed. Simultaneously, a physicochemical characterization of the immobilized enzyme regarding its kinetic behaviour was performed. The activity/pH profile observed points to an effect of pH on activity that is completely different from the case of ADH in solution. The disturbance in the typical bell-shaped profile owing to the fact that the enzyme was immobilized is explained on the basis of a potent limitation to the diffusion of the protons in the support. The findings of the present work also reveal the existence of an effect that limits free external diffusion of the substrate towards and/or the product from the support; this effect seems to be the determinant of the overall rate of the enzymatic reaction and is thus of great importance in the effective kinetic behaviour (v([S])) of immobilized ADH, whose kinetic behaviour is complex (non-Michaelian), as may be seen from the lack of linearity observed in the corresponding double reciprocal and Eadie-Hofstee plots. By non-linear regression numerical analysis of the v([S]) data and application of the F-test for model discrimination, the minimum rate equation necessary to describe the intrinsic kinetic behaviour of PVDF-immobilized ADH proved to be one of the polynomial quotient type of degree 2:2 (in substrate concentration).

  12. Catalysis of Rice Straw Hydrolysis by the Combination of Immobilized Cellulase from Aspergillus niger on β-Cyclodextrin-Fe3O4 Nanoparticles and Ionic Liquid

    Directory of Open Access Journals (Sweden)

    Po-Jung Huang

    2015-01-01

    Full Text Available Cellulase from Aspergillus niger was immobilized onto β-cyclodextrin-conjugated magnetic particles by silanization and reductive amidation. The immobilized cellulase gained supermagnetism due to the magnetic nanoparticles. Ninety percent of cellulase was immobilized, but the activity of immobilized cellulase decreased by 10%. In this study, ionic liquid (1-butyl-3-methylimidazolium chloride was introduced into the hydrolytic process because the original reaction was a solid-solid reaction. The activity of immobilized cellulase was improved from 54.87 to 59.11 U g immobilized cellulase−1 at an ionic liquid concentration of 200 mM. Using immobilized cellulase and ionic liquid in the hydrolysis of rice straw, the initial reaction rate was increased from 1.629 to 2.739 g h−1 L−1. One of the advantages of immobilized cellulase is high reusability—it was usable for a total of 16 times in this study. Compared with free cellulase, magnetized cellulase can be recycled by magnetic field and the activity of immobilized cellulase was shown to remain at 85% of free cellulase without denaturation under a high concentration of glucose (15 g L−1. Therefore, immobilized cellulase can hydrolyze rice straw continuously compared with free cellulase. The amount of harvested glucose can be up to twentyfold higher than that from the hydrolysis by free cellulase.

  13. Chemoenzymatic reversible immobilization and labeling of proteins without prior purification.

    Science.gov (United States)

    Rashidian, Mohammad; Song, James M; Pricer, Rachel E; Distefano, Mark D

    2012-05-23

    Site-specific chemical modification of proteins is important for many applications in biology and biotechnology. Recently, our laboratory and others have exploited the high specificity of the enzyme protein farnesyltransferase (PFTase) to site-specifically modify proteins through the use of alternative substrates that incorporate bioorthogonal functionality including azides and alkynes. In this study, we evaluate two aldehyde-containing molecules as substrates for PFTase and as reactants in both oxime and hydrazone formation. Using green fluorescent protein (GFP) as a model system, we demonstrate that the purified protein can be enzymatically modified with either analogue to yield aldehyde-functionalized proteins. Oxime or hydrazone formation was then employed to immobilize, fluorescently label, or PEGylate the resulting aldehyde-containing proteins. Immobilization via hydrazone formation was also shown to be reversible via transoximization with a fluorescent alkoxyamine. After characterizing this labeling strategy using pure protein, the specificity of the enzymatic process was used to selectively label GFP present in crude E. coli extract followed by capture of the aldehyde-modified protein using hydrazide-agarose. Subsequent incubation of the immobilized protein using a fluorescently labeled or PEGylated alkoxyamine resulted in the release of pure GFP containing the desired site-specific covalent modifications. This procedure was also employed to produce PEGylated glucose-dependent insulinotropic polypeptide (GIP), a protein with potential therapeutic activity for diabetes. Given the specificity of the PFTase-catalyzed reaction coupled with the ability to introduce a CAAX-box recognition sequence onto almost any protein, this method shows great potential as a general approach for selective immobilization and labeling of recombinant proteins present in crude cellular extract without prior purification. Beyond generating site-specifically modified proteins, this

  14. Airline Chair-rest Deconditioning: Induction of Immobilization Thromboemboli?

    Science.gov (United States)

    Greenleaf, J. E.; Rehrer, N. J.; Mohler, S. R.; Quach, D. T.; Evans, D. G.; Dalton, Bonnie P. (Technical Monitor)

    2002-01-01

    Air passenger miles will likely double by year 2020. The altered and restrictive environment in an airliner cabin can influence hematological homeostasis in passengers and crew. Flight-related deep various thromboemboli (DVT) have been associated with at least 577 deaths on 42 of 120 airlines from 1977 to 1984 (25 deaths/million departures), whereas many such cases go unreported. However, there are four major factors that could influence formation of possible flight-induced DVT: sleeping accomodations (via sitting immobilization), travelers' medical history (via tissue injury), cabin environmental factors (via lower partial pressure of oxygen and lower relative humidity), and the more encompassing chair-rest deconditioning (C-RD) syndrome. There is ample evidence that recent injury and surgery (especially in deconditioned hospitalized patients) facilitate thrombophlebitis and formation of DVT that may be exacerbated by the immobilization of prolonged air travel. In the healthy flying population immobilization factors associated with prolonged (> 5 hr) C-RID such as total body dehydration, hypovolemia and increased blood viscosity, and reduced various blood flow (pooling) in the legs may facilitate formation of DVT. However, data from at least four case-controlled epidemiological studies did not confirm a direct causative relationship between air travel and DART, but factors such as history of vascular thromboemboli, various insufficiency, chronic heart failure, obesity, immobile standing position, more than 3 pregnancies, infectious disease, long-distance travel, muscular trauma and violent physical effort were significantly more frequent in DVT patients than in controls. Thus, there is no clear, direct evidence yet that prolonged sitting in airliner seats, or prolonged experimental chair-rest- or bed- rest-deconditioning treatments cause deep various thromboemboli in healthy people.

  15. Immobilized redox mediator on metal-oxides nanoparticles and its catalytic effect in a reductive decolorization process.

    Science.gov (United States)

    Alvarez, L H; Perez-Cruz, M A; Rangel-Mendez, J R; Cervantes, F J

    2010-12-15

    Different metal-oxides nanoparticles (MONP) including α-Al(2)O(3), ZnO and Al(OH)(3), were utilized as adsorbents to immobilize anthraquinone-2,6-disulfonate (AQDS). Immobilized AQDS was subsequently tested as a solid-phase redox mediator (RMs) for the reductive decolorization of the azo dye, reactive red 2 (RR2), by anaerobic sludge. The highest adsorption capacity of AQDS was achieved on Al(OH)(3) nanoparticles, which was ∼0.16 mmol g(-1) at pH 4. Immobilized AQDS increased up to 7.5-fold the rate of decolorization of RR2 by anaerobic sludge as compared with sludge incubations lacking AQDS. Sterile controls including immobilized AQDS did not show significant (reduction) were not responsible for the enhanced decolorization achieved. Immobilization of AQDS on MONP was very stable under the applied experimental conditions and spectrophotometric screening did not detect any detachment of AQDS during the reductive decolorization of RR2, confirming that immobilized AQDS served as an effective RMs. The present study constitutes the first demonstration that immobilized quinones on MONP can serve as effective RMs in the reductive decolorization of an azo dye. The immobilizing technique developed could be applied in anaerobic wastewater treatment systems to accelerate the redox biotransformation of recalcitrant pollutants.

  16. Preparation of Seeding Type Immobilized Microorganisms and Their Degradation Characteristics on Di-n-Butyl Phthalate

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    To study the preparation of seeding type immobilized microorganisms and their degradation characteristics on di-n-butyl phthalate (DBP). Methods Diatomite, clinoptilolite, silk zeolite, and coal fly ash were chosen as reserved materials and modified. Their adsorption capacity and intensity in the bacteria were determined and the best carrier was picked out. The seeding type immobilized microorganisms were prepared by the best carrier and then it degraded DBP under different primary concentration, vibration rate, pH, temperature in the presence of metal compounds. Results The adsorption capacity of the modified coal fly ash, silk zeolite, clinoptilolite and zeolite was 44.2%, 71.6%, 84.0%, and 94.4%, respectively, which was 1.66, 1.49, 1.37, and 1.16 times as high as that of their natural state. Their adsorption intensity was 72.1%, 90.5%, 90.1%,and 91.1% in turn. The modified diatomite was selected to prepare the seeding type immobilized microorganisms. When the primary DBP concentration was 100 to 500 mg/L, the DBP-degraded rate of the immobilized microorganisms could be above 80%. The degradation activity of both the dissociative and immobilized microorganisms was higher in vibration than in stillness.When pH was 6.0 to 9.0, the DBP-degraded rate of the immobilized microorganisms was above 82%, which was higher than the dissociative microorganisms. When the temperature was between 20℃ and 40℃, the DBP-degraded rate could reach 84.5% in 24 h. The metal compounds could inhibit the degradation activity of both the dissociative and immobilized microorganisms. The degradation process of the immobilized microorganisms could be described by the first-order model.Conclusion The adsorption capacity of the diatomite, clinoptilolite, silk zeolite and coal fly ash on DBP-degrading bacteria can be improved obviously after they are modified. The modified diatomite is best in terms of its adsorption capacity and intensity. Its seeding type immobilized microorganisms could

  17. The study of the influence of temperature and initial glucose concentration on the fermentation process in the presence of Saccharomyces cerevisiae yeast strain immobilized on starch gels by reversed-flow gas chromatography.

    Science.gov (United States)

    Lainioti, G Ch; Kapolos, J; Koliadima, A; Karaiskakis, G

    2012-01-01

    The technique of reversed-flow gas chromatography (RFGC) was employed for the determination of the alcoholic fermentation phases and of kinetic parameters for free and immobilized cell systems, at different initial glucose concentrations and temperature values. In addition to this, due to its considerable advantages over other techniques, RFGC was used for the characterization of a new biocatalyst, yeast cells immobilized on starch gel, and especially wheat starch gel. Immobilization of wine yeast Saccharomyces cerevisiae AXAZ-1 was accomplished on wheat and corn starch gels in order to prepare new biocatalysts with great interest for the fermentation industry. The RFGC led with great accuracy, resulting from a literature review, to the determination of reaction rate constants and activation energies at each phase of the fermentation processes. A maximum value of rate constants was observed at initial glucose concentration of 205 g/L, where a higher number of yeast cells was observed. The increase of glucose concentrations had a negative influence on the growth of AXAZ-1 cells and rate constants were decreased. The decrease of fermentation temperature caused a substantial reduction in the viability of immobilized cells as well as in rate constant values. Activation energies of corn starch gel presented lower values than those of wheat starch gel. However, the two supports showed higher catalytic efficiency than free cell systems, proving that starch gels may act as a promoter of the catalytic activity of the yeast cells involved in the fermentation process.

  18. Effect of passive stretching on the immobilized soleus muscle fiber morphology

    Directory of Open Access Journals (Sweden)

    Coutinho E.L.

    2004-01-01

    Full Text Available The aim of the present study was to determine the effect of stretching applied every 3 days to the soleus muscle immobilized in the shortened position on muscle fiber morphology. Eighteen 16-week-old Wistar rats were used and divided into three groups of 6 animals each: a the left soleus muscle was immobilized in the shortened position for 3 weeks; b during immobilization, the soleus was stretched for 40 min every 3 days; c the non-immobilized soleus was only stretched. Left and right soleus muscles were examined. One portion of the soleus was frozen for histology and muscle fiber area evaluation, while the other portion was used to identify the number and length of serial sarcomeres. Immobilized muscles (group A showed a significant decrease in weight (44 ± 6%, length (19 ± 7%, serial sarcomere number (23 ± 15%, and fiber area (37 ± 31% compared to the contralateral muscles (P < 0.05, paired Student t-test. The immobilized and stretched soleus (group B showed a similar reduction but milder muscle fiber atrophy compared to the only immobilized group (22 ± 40 vs 37 ± 31%, respectively; P < 0.001, ANOVA test. Muscles submitted only to stretching (group C significantly increased the length (5 ± 2%, serial sarcomere number (4 ± 4%, and fiber area (16 ± 44% compared to the contralateral muscles (P < 0.05, paired Student t-test. In conclusion, stretching applied every 3 days to immobilized muscles did not prevent the muscle shortening, but reduced muscle atrophy. Stretching sessions induced hypertrophic effects in the control muscles. These results support the use of muscle stretching in sports and rehabilitation.

  19. Degradation of pyrene by immobilized microorganisms in saline-alkaline soil

    Institute of Scientific and Technical Information of China (English)

    Shanxian Wang; Xiaojun Li; Wan Liu; Peijun Li; Lingxue Kong; Wenjie Ren; Haiyan Wu; Ying TU

    2012-01-01

    Biodegradation of polycyclic aromatic hydrocarbons (PAHs) is very difficult in saline-alkaline soil due to the inhibition of microbial growth under saline-alkaline stress.The microorganisms that can most effectively degrade PAHs were screened by introducing microorganisms immobilized on farm byproducts and assessing the validity of the immobilizing technique for PAHs degradation in pyrene-contaminated saline-alkaline soil.Among the microorganisms examined,it was found that Mycobacterium sp.B2 is the best,and can degrade 82.2% and 83.2% of pyrene for free and immobilized cells after 30 days of incubation.The immobilization technique could increase the degradation of pyrene significantly,especially for fungi.The degradation of pyrene by the immobilized microorganisms Mucor sp.F2,fungal consortium MF and co-cultures of MB+MF was increased by 161.7% (P < 0.05),60.1% (P <0.05) and 59.6% (P < 0.05) after 30 days,respectively,when compared with free F2,MF and MB+MF.Scanning electron micrographs of the immobilized microstructure proved the positive effects of the immobilized microbial technique on pyrene remediation in salinealkaline soil,as the interspace of the carrier material structure was relatively large,providing enough space for cell growth.Co-cultures of different bacterial and fungal species showed different abilities to degrade PAHs.The present study suggests that Mycobacterium sp.B2 can be employed for in situ bioremediation of PAHs in saline-alkaline soil,and immobilization of fungi on farm byproducts and nutrients as carriers will enhance fungus PAH-degradation ability in saline-alkaline soil.

  20. Immobilization of Lipid Substrates: Application on Phospholipase A2 Determination.

    Science.gov (United States)

    Karkabounas, Athanassios; Georgiadou, Dimitra G; Argitis, Panagiotis; Psycharis, Vassilios; Nakos, George; Kosmas, Agni M; Lekka, Marilena E

    2015-12-01

    The purpose of the study was to assess a fluorimetric assay for the determination of total phospholipase A(2) (PLA(2)) activity in biological samples introducing the innovation of immobilized substrates on crosslinked polymeric membranes. The immobilized C(12)-NBD-PtdCho, a fluorescent analogue of phosphatidylcholine, exhibited excellent stability for 3 months at 4 °C and was not desorbed in the aqueous reaction mixture during analysis. The limit of detection was 0.5 pmol FA (0.2 pg) and the linear part of the response curve extended from 1 up to 190 nmol FA/h/mL sample. The intra- and inter-day relative standard deviations (%RSD), were ≤6 and ≤9 %, respectively. Statistical comparison with other fluorescent methods showed excellent correlation and agreement. Semiempirical calculations showed a fair amount of electrostatic interaction between the NBD-labeled substrate and the crosslinked polyvinyl alcohol with the styryl pyridinium residues (PVA-SbQ) material, from the plane of which, the sn-2 acyl chain of the phospholipid stands out and is accessible by PLA(2). Atomic Force Microscopy revealed morphological alterations of the immobilized substrate after the reaction with PLA(2). Mass spectrometry showed that only C(12)-NBD-FA, the PLA(2 )hydrolysis product, was detected in the reaction mixture, indicating that PLA(2) recognizes PVA-SbQ/C(12)-NBD-PtdCho as a surface to perform catalysis.

  1. Immobilization mediated enhancement of phyllanthin and hypophyllanthin from Phyllanthus amarus

    Institute of Scientific and Technical Information of China (English)

    J.S.Thakur; R.K.Agarwal; M.D.Kharya

    2012-01-01

    Phyllanthus amarus plant is used in the traditional system of medicine as a hepatoprotective drug for which the major lignans phyllanthin and hypophyllanthin are responsible.So far,no significant work has been done on the culture of this plant.Realizing the hepatoprotective potential,the present investigation was undertaken.A cost effective process was developed for enhancing phyllanthin and hypophyllanthin utilizing the immobilization technique.HPTLC was used to compare the phyllanthin and hypophyllanthin contents in calcium alginate immobilized cells obtained from fresh grown plants and MS medium was supplemented with different abiotic elicitors,under aseptic conditions for the treatment with chitosan,copper sulphate,phenylalanine and silver nitrate solution to make the whole process commercially viable.It was revealed that silver nitrate and phenylalanine at low concentration enhances phyllanthin and hypophyllanthin yield as compared to control immobilized cell culture.The study revealed that an increase in the content of phyllanthin and hypophyllanthin was elicitor concentration dependent and silver nitrate treatment gave a maximum yield of hepatoprotective bioactives as compared to the other abiotic elicitors used.

  2. Production of butanol and isopropanol with an immobilized Clostridium.

    Science.gov (United States)

    Yang, Ying; Hoogewind, Adam; Moon, Young Hwan; Day, Donal

    2016-03-01

    Clostridium beijerinckii optinoii is a Clostridium species that produces butanol, isopropanol and small amounts of ethanol. This study compared the performances of batch and continuous immobilized cell fermentations, investigating how media flow rates and nutritional modification affected solvent yields and productivity. In 96-h batch cultures, with 80 % of the 30 g L(-1) glucose consumed in synthetic media, solvent concentration was 9.45 g L(-1) with 66.0 % as butanol. In a continuous fermentation using immobilized C. beijerinckii optinoii cells, also with 80 % of 30 g L(-1) glucose utilization, solvent productivity increased to 1.03 g L(-1) h(-1). Solvent concentration reached 12.14 g L(-1) with 63.0 % as butanol. Adjusting the dilution rate from 0.085 to 0.050 h(-1) to allow extended residence time in column was required when glucose concentration in fresh media was increased from 30 to 50 g L(-1). When acetate was used to improve the buffer capacity in media, the solvent concentration reached 12.70 on 50 g L(-1) glucose. This continuous fermentation using immobilized cells showed technical feasibility for solvent production.

  3. Protein synthesis rates in atrophied gastrocnemius muscles after limb immobilization

    Science.gov (United States)

    Tucker, K. R.; Seider, M. J.; Booth, F. W.

    1981-01-01

    Noting that protein synthesis declines in the gastrocnemius 6 hr after immobilization, the study sought to detect an increase of protein synthesis when the limb was freed, and to examine the effects of exercise on the rate of increase. Rats were used as subjects, with their hind legs in plaster of Paris in plantar flexion to eliminate strain on the gastrocnemius. Periods of immobilization were varied and samples of blood from the muscle were taken to track protein synthesis rates for different groups in immobilization and exercise regimens (running and weightlifting). Synthesis rates declined 3.6% during time in the cast, then increased 6.3%/day after the casts were removed. Both running and weightlifting were found to increase the fractional rate of protein formation in the gastrocnemius muscle when compared with contralateral muscles that were not exercised and were used as controls, suggesting that the mechanism controlling protein synthesis in skeletal muscles is rapidly responsive to changes in muscular contractile activity.

  4. Immobilization of Acidithiobacillus ferrooxidans and ferric iron production

    Institute of Scientific and Technical Information of China (English)

    ZHOU Hong-bo; LIU Xi; QIU Guan-zhou; LIU Jian-she; CHEN Xin-hua

    2006-01-01

    Cobblestone, glass beads and active carbon were selected as bacterial supports to study immobilization of Acidithiobacillus ferrooxidans in packed bed reactors. The production of ferric iron was then investigated in these immobilized reactors in batch and continuous operation modes. The results show that stable biofilm forms in cobblestone and active carbon supports, thus these two kinds of supports are suitable for immobilization of A. ferrooxidans. In batch culture, ferric iron productivity in reactor with cobblestone as supports is 0.61 g/(L·h), which is 1.49 times higher than that in suspended culture reactor. In continuous operation mode, the maximum ferric iron productivity in reactor with cobblestone as supports is 1.54 g/(Lh), which is 3.76 times higher than that in suspended culture reactor. The maximum ferric iron productivity in reactor with active carbon as supports is 1.89 g/(L·h), which is 4.61 times higher than that in suspended culture reactor. In addition to bacteria, the results of X-ray diffraction and scanning electronic microscope analysis show that there is a lot of exopolysaccharide, jarosite and ammoniojarosite in biofilm, which plays important role in the formation ofbiofilm.

  5. Potential applications of carbohydrases immobilization in the food industry.

    Science.gov (United States)

    Contesini, Fabiano Jares; de Alencar Figueira, Joelise; Kawaguti, Haroldo Yukio; de Barros Fernandes, Pedro Carlos; de Oliveira Carvalho, Patrícia; da Graça Nascimento, Maria; Sato, Hélia Harumi

    2013-01-11

    Carbohydrases find a wide application in industrial processes and products, mainly in the food industry. With these enzymes, it is possible to obtain different types of sugar syrups (viz. glucose, fructose and inverted sugar syrups), prebiotics (viz. galactooligossacharides and fructooligossacharides) and isomaltulose, which is an interesting sweetener substitute for sucrose to improve the sensory properties of juices and wines and to reduce lactose in milk. The most important carbohydrases to accomplish these goals are of microbial origin and include amylases (α-amylases and glucoamylases), invertases, inulinases, galactosidases, glucosidases, fructosyltransferases, pectinases and glucosyltransferases. Yet, for all these processes to be cost-effective for industrial application, a very efficient, simple and cheap immobilization technique is required. Immobilization techniques can involve adsorption, entrapment or covalent bonding of the enzyme into an insoluble support, or carrier-free methods, usually based on the formation of cross-linked enzyme aggregates (CLEAs). They include a broad variety of supports, such as magnetic materials, gums, gels, synthetic polymers and ionic resins. All these techniques present advantages and disadvantages and several parameters must be considered. In this work, the most recent and important studies on the immobilization of carbohydrases with potential application in the food industry are reviewed.

  6. Potential Applications of Carbohydrases Immobilization in the Food Industry

    Directory of Open Access Journals (Sweden)

    Hélia Harumi Sato

    2013-01-01

    Full Text Available Carbohydrases find a wide application in industrial processes and products, mainly in the food industry. With these enzymes, it is possible to obtain different types of sugar syrups (viz. glucose, fructose and inverted sugar syrups, prebiotics (viz. galactooligossacharides and fructooligossacharides and isomaltulose, which is an interesting sweetener substitute for sucrose to improve the sensory properties of juices and wines and to reduce lactose in milk. The most important carbohydrases to accomplish these goals are of microbial origin and include amylases (α-amylases and glucoamylases, invertases, inulinases, galactosidases, glucosidases, fructosyltransferases, pectinases and glucosyltransferases. Yet, for all these processes to be cost-effective for industrial application, a very efficient, simple and cheap immobilization technique is required. Immobilization techniques can involve adsorption, entrapment or covalent bonding of the enzyme into an insoluble support, or carrier-free methods, usually based on the formation of cross-linked enzyme aggregates (CLEAs. They include a broad variety of supports, such as magnetic materials, gums, gels, synthetic polymers and ionic resins. All these techniques present advantages and disadvantages and several parameters must be considered. In this work, the most recent and important studies on the immobilization of carbohydrases with potential application in the food industry are reviewed.

  7. Immobilized Bioluminescent Reagents in Flow Injection Analysis.

    Science.gov (United States)

    Nabi, Abdul

    Available from UMI in association with The British Library. Bioluminescent reactions exhibits two important characteristics from an analytical viewpoint; they are selective and highly sensitive. Furthermore, bioluminescent emissions are easily measured with a simple flow-through detector based on a photomultiplier tube and the rapid and reproducible mixing of sample and expensive reagent is best achieved by a flow injection manifold. The two most important bioluminescent systems are the enzyme (luciferase)/substrate (luciferin) combinations extracted from fireflies (Photinus pyralis) and marine bacteria (Virio harveyi) which requires ATP and NAD(P)H respectively as cofactors. Reactions that generate or consume these cofactors can also be coupled to the bioluminescent reaction to provide assays for a wide range of clinically important species. A flow injection manifold for the study of bioluminescent reactions is described, as are procedures for the extraction, purification and immobilization of firefly and bacterial luciferase and oxidoreductase. Results are presented for the determination of ATP using firefly system and the determination of other enzymes and substrates participating in ATP-converting reactions e.g. creatine kinase, ATP-sulphurylase, pyruvate kinase, creatine phosphate, pyrophosphate and phophoenolypyruvate. Similarly results are presented for the determination of NAD(P)H, FMN, FMNH_2 and several dehydrogenases which produce NAD(P)H and their substrates, e.g. alcohol, L-lactate, L-malate, L-glutamate, Glucose-6-phosphate and primary bile acid.

  8. Study of the surface crystallization and resistance to dissolution of niobium phosphate glasses for nuclear waste immobilization; Estudo da cristalizacao superficial e da resistencia a dissolucao de vidros niobofosfatos visando a imobilizacao de rejeitos radioativos

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, Heveline

    2008-07-01

    The surface crystallization and the dissolution rate of three phosphate glass compositions containing different amounts of niobium oxide were studied. The glasses were named Nb30, Nb37, and Nb44 according to the nominal content of niobium oxide in the glass composition. The three compositions were evaluated keeping the P{sub 2}O{sub 5}/K{sub 2}O ratio constant and varying the amount of Nb{sub 2}O{sub 5}. These glasses were produced by melting appropriate chemical compounds at 1500 deg C for 0.5 hour. The crystalline phases which were nucleated on the glass surface after heat treatment were determined by X-ray diffraction. The crystalline structures depend on the amount of niobium oxide in the glass composition. The crystal morphologies were observed by using an optical microscope, and their characteristics are specific for each kind of crystalline phase. The crystal growth rate and the surface nuclei density were determined for each glass composition, and they depend on each crystalline phase nucleated on the surface. From the differential thermal analysis curves it was determined that the Nb44 glass containing 46.5 mol por cent of niobium oxide is the most thermally stable against crystallization when compared to the Nb30 and Nb37 glasses. According to the activation energies determined for crystal growth on the surface of each glass type, the Nb44 glass can also be considered the most resistant one against crystallization. The dissolution rate for the Nb44 glass after 14 days immersed in an aqueous solution with pH equals to 7 at 90 deg C is the lowest (9.0 x 10{sup -7} g. cm{sup -2} . day{sup -1}) when compared to the other two glass compositions. The dissolution rates in acidic and neutral solutions of all studied glasses meet the international standards for materials which can be used in the immobilization of nuclear wastes. (author)

  9. The Effect of Glutaraldehyde Cross-Linking on the Enzyme Activity of Immobilized &beta-Galactosidase on Chitosan Bead

    Directory of Open Access Journals (Sweden)

    He Chen

    2013-07-01

    Full Text Available The effect of glutaraldehyde solution concentration, cross-linking time, cross-linking pH and cross-linking temperature on the enzyme activity of the immobilized &beta-galactosidase on Chitosan beads were studied. The enzyme activity was measured after immobilized by detecting the absorbance value at 420 nm.The results were as follows: the immobilized enzyme activity reached the maximum when the concentration of glutaraldehyde solution was 0.3%.The immobilized enzyme had optimal cross-linking time of 3h, optimal cross-linking pH of 6.5, optimal cross-linking temperature of 25°C, under these conditions, the immobilized enzyme activity reached 101, 96, 90 U/g, respectively.

  10. 同时培养法与吸附法微生物固定化对比%Comparative study of two immobilization technology — simultaneity culture and adsorption

    Institute of Scientific and Technical Information of China (English)

    山丹; 马放; 张斯; 王晨

    2012-01-01

    To find a method of microbial immobilization which was efficient, fast and applied to biomass carri- er -- mycelial pellet, bacteria JH -9 were immobilized onto mycelial pellet formed by Aspergillus Y3. And the characteristics and internal structure of two different immobilization methods were compared. The simulta- neity culture immobilization method could immobilize more bacteria and with little time with same bacteria in- oculation count. Moreover, the volume and quantity of combined mycelial pellets formed by simultaneity cul- ture immobilization method were bigger than that by adsorption immobilization method, and its diameter ,weight and relative density were smaller. To immobilize with the same method, the size and volume of combined my- celial pellets were in direct proportion to the inoculation count of engineering bacteria, whereas its weight and relative density were opposite. Bacteria were immobilized and grew on each mycelium of combined mycelial pellets formed by simultaneity culture immobilization method.%为寻找一种适用于菌丝球生物质载体高效、快捷的微生物固定化方法,分别采用同时培养法和吸附法将高效苯胺降解细菌JH-9固定于黑曲霉菌Y3形成的生物质载体菌丝球上,并对两种微生物固定化方法所形成的混合菌丝球的特性和内部结构进行对比.结果表明:在接种细菌数量相同的条件下,同时培养法固定化细菌所用的时间缩短,且在单位时间内固定的细菌数量更多.同时培养法形成的混合菌丝球堆积体积更大,成球总数量更多,球体直径较小,总质量和总相对密度也较小.当采用同一种固定化方法时,混合菌丝球的堆积体积、成球大小与功能菌的接种量成正比;而形成混合菌丝球的总质量和总相对密度却与功能菌的接种量成反比.同时培养法形成的混合菌丝球内部细菌非常均匀地排列生长在每一根菌丝上.

  11. Immobilization of Pepsin onto Chitosan Silica Nanobeads with Glutaraldehyde as Crosslink Agent

    Directory of Open Access Journals (Sweden)

    Sari Edi Cahyaningrum

    2014-10-01

    Full Text Available Glutaraldehyde crosslinked chitosan - silica nanobeads have been used as a support in the immobiliza-tion process of pepsin. The effect of pH, pepsin concentration, and temperature on the characteristics of both free and immobilized pepsin had been investigated in this study. The results showed that the im-mobilized pepsin has wider pH range, better capacity, performance and stability to high temperatures compared with those of free pepsin. The immobilized pepsin can be used for 8 to 10 times at which the activity remains 20%, whereas the free pepsin can only be used once. These results suggested promis-ing applications of immobilized enzyme as biocatalyst. © 2014 BCREC UNDIP. All rights reserved.Received: 1st July 2014; Revised: 3rd September 2014; Accepted: 3rd September 2014How to Cite: Cahyaningrum, S.E., Sianita, M.M. (2014. Immobilization of Pepsin onto Chitosan Silica Nanobeads with Glutaraldehyde as Crosslink Agent. Bulletin of Chemical Reaction Engineering & Catalysis, 9 (3: 263-269. (doi:10.9767/bcrec.9.3.7060.263-269 Permalink/DOI: http://dx.doi.org/10.9767/bcrec.9.3.7060.263-269

  12. [Effects of the size of magnetic particles of immobilized enzyme reactors on the digestion performance].

    Science.gov (United States)

    Zhang, Jiao; Zhou, Lianqi; Tian, Fang; Zhang, Yangjun; Qian, Xiaohong

    2013-02-01

    We applied immobilized enzyme reactors prepared with different sizes of magnetic particles into protein and proteome digestion. In addition, the influences of different sizes of the magnetic particles were studied on the reunion, enzyme efficiency and leakage sites. The experimental results showed that in comparison with the submicron magnetic particles, the amount of trypsin immobilized on the magnetic nanoparticles was 3. 5 times more than that of the submicron magnetic particles. However, the enzymatic efficiency was at the same level when the same amount of trypsin was used, and the reunion phenomenon was obviously improved when the size of the magnetic nanoparticles increased. Taking the immobilized enzyme reactor of 20 nm magnetic nanoparticles as an example, the digestion performance was further examined. The experimental results showed that rapid digestion could be achieved within 1 mm when the mass ratio of the trypsin and bovine serum albumin was 1:1. The peptide number of 0 missed cleavage site and the sequence coverage changed little after the protein was digested for 10 mm. It was concluded that the digestion efficiency of the immobilized enzyme reactor was much better than that of the in-solution digestion. When the immobilized enzyme reactors and the free trypsin were used for digestion, little differences of the leakage sites were found. Therefore, the immobilized enzyme reactors prepared with different sizes of magnetic particles can be applied in proteomic research for quick and efficient digestion.

  13. Evaluation of protein immobilization capacity on various carbon nanotube embedded hydrogel biomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Derkus, Burak, E-mail: burakderkus@gmail.com; Emregul, Kaan Cebesoy; Emregul, Emel

    2015-11-01

    This study investigates effective immobilization of proteins, an important procedure in many fields of bioengineering and medicine, using various biomaterials. Gelatin, alginate and chitosan were chosen as polymeric carriers, and applied in both their composites and nanocomposite forms in combination with carbon nanotubes (CNTs). The prepared nano/composite structures were characterized using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TG) and contact angle analysis (CA). Electrochemical impedance spectroscopy analysis revealed gelatin composites in general to exhibit better immobilization performance relative to the native gelatin which can be attributed to enhanced film morphologies of the composite structures. Moreover, superior immobilization efficiencies were obtained with the addition of carbon nanotubes, due to their conducting and surface enhancement features, especially in the gelatin–chitosan structures due to the presence of structural active groups. - Highlights: • Various nanocomposite biomaterials were developed for efficient immobilization of proteins. • CNTs enhance the immobilization efficiency owing to their conducting and surface enhancement features. • Gelatin–chitosan–CNTs structure is promising immobilization matrix thanks to its effective CNTs binding capacity.

  14. Recovery of skeletal muscle after 3 mo of hindlimb immobilization in rats

    Science.gov (United States)

    Booth, F. W.; Seider, M. J.

    1979-01-01

    During immobilization, skeletal muscle undergoes decreases in size and strength with concomitant atrophic and degenerative changes in slow-twitch muscle fibers. Currently there are no objective data in slow-twitch muscle demonstrating recovery of biochemical or physiological indices following termination of immobilization. The purpose of this study was to determine whether the soleus, a slow-twitch muscle, could recover normal biochemical or physiological levels following termination of immobilization. Adenosine triphosphate, glycogen, and protein concentration (mg/g wet wt) all significantly decreased following 90 days of hindlimb immobilization, but these three values returned to control levels by the 60th recovery day. Similarly, soleus muscle wet weight and protein content (mg protein/muscle) returned to control levels by the 14th recovery day. In contrast, maximal isometric tension did not return to normal until the 120th day. These results indicate that following muscular atrophy, which was achieved through 90 days of hindlimb immobilization, several biochemical and physiological values in skeletal muscle are recovered at various times after the end of immobilization.

  15. Catalytic performance and molecular dynamic simulation of immobilized CC bond hydrolase based on carbon nanotube matrix.

    Science.gov (United States)

    Zhou, Hao; Qu, Yuanyuan; Kong, Chunlei; Li, Duanxing; Shen, E; Ma, Qiao; Zhang, Xuwang; Wang, Jingwei; Zhou, Jiti

    2014-04-01

    Carbon nanotube (CNT) has been proved to be a kind of novel support for enzyme immobilization. In this study, we tried to find the relationship between conformation and catalytic performance of immobilized enzyme. Two CC bond hydrolases BphD and MfphA were immobilized on CNTs (SWCNT and MWCNT) via physical adsorption and covalent attachment. Among the conjugates, the immobilized BphD on chemically functionalized SWCNT (BphD-CSWCNT) retained the highest catalytic efficiency (kcat/Km value) compared to free BphD (92.9%). On the other hand, when MfphA bound to pristine SWCNT (MfphA-SWCNT), it was completely inactive. Time-resolved fluorescence spectrum indicated the formation of static ground complexes during the immobilization processes. Circular dichroism (CD) showed that the secondary structures of immobilized enzymes changed in varying degrees. In order to investigate the inhibition mechanism of MfphA by SWCNT, molecular dynamics simulation was employed to analyze the adsorption process, binding sites and time evolution of substrate tunnels. The results showed that the preferred binding sites (Trp201 and Met81) of MfphA for SWCNT blocked the main substrate access tunnel, thus making the enzyme inactive. The "tunnel-block" should be a novel possible inhibition mechanism for enzyme-nanotube conjugate.

  16. Degradation of pyrene by immobilized microorganisms in saline-alkaline soil.

    Science.gov (United States)

    Wang, Shanxian; Li, Xiaojun; Liu, Wan; Li, Peijun; Kong, Lingxue; Ren, Wenjie; Wu, Haiyan; Tu, Ying

    2012-01-01

    Biodegradation of polycyclic aromatic hydrocarbons (PAHs) is very difficult in saline-alkaline soil due to the inhibition of microbial growth under saline-alkaline stress. The microorganisms that can most effectively degrade PAHs were screened by introducing microorganisms immobilized on farm byproducts and assessing the validity of the immobilizing technique for PAHs degradation in pyrene-contaminated saline-alkaline soil. Among the microorganisms examined, it was found that Mycobacterium sp. B2 is the best, and can degrade 82.2% and 83.2% of pyrene for free and immobilized cells after 30 days of incubation. The immobilization technique could increase the degradation of pyrene significantly, especially for fungi. The degradation of pyrene by the immobilized microorganisms Mucor sp. F2, fungal consortium MF and co-cultures of MB+MF was increased by 161.7% (P soil, as the interspace of the carrier material structure was relatively large, providing enough space for cell growth. Co-cultures of different bacterial and fungal species showed different abilities to degrade PAHs. The present study suggests that Mycobacterium sp. B2 can be employed for in situ bioremediation of PAHs in saline-alkaline soil, and immobilization of fungi on farm byproducts and nutrients as carriers will enhance fungus PAH-degradation ability in saline-alkaline soil.

  17. Ethanol fermentation of molasses by Saccharomyces cerevisiae cells immobilized onto sugar beet pulp

    Directory of Open Access Journals (Sweden)

    Vučurović Vesna M.

    2012-01-01

    Full Text Available Natural adhesion of Saccharomyces cerevisiae onto sugar beet pulp (SBP is a very simple and cheap immobilization method for retaining high cells density in the ethanol fermentation system. In the present study, yeast cells were immobilized by adhesion onto SBP suspended in the synthetic culture media under different conditions such as: glucose concentration (100, 120 and 150 g/l, inoculum concentration (5, 10 and 15 g/l dry mass and temperature (25, 30, 35 and 40°C. In order to estimate the optimal immobilization conditions the yeast cells retention (R, after each immobilization experiment was analyzed. The highest R value of 0.486 g dry mass yeast /g dry mass SBP was obtained at 30°C, glucose concentration of 150 g/l, and inoculum concentration of 15 g/l. The yeast immobilized under these conditions was used for ethanol fermentation of sugar beet molasses containing 150.2 g/l of reducing sugar. Efficient ethanol fermentation (ethanol concentration of 70.57 g/l, fermentation efficiency 93.98% of sugar beet molasses was achieved using S. cerevisiae immobilized by natural adhesion on SBP. [Projekat Ministarstva nauke Republike Srbije, br. TR-31002

  18. Immobilized Pseudomonas cepacia lipase for biodiesel fuel production from soybean oil

    Energy Technology Data Exchange (ETDEWEB)

    Noureddini, H.; Gao, X.; Philkana, R.S. [Nebraska-Lincoln Univ., NE (United States). Dept. of Chemical Engineering

    2005-05-01

    Enzymatic transesterification of soybean oil with methanol and ethanol was studied. Of the nine lipases that were tested in the initial screening, lipase PS from Pseudomonas cepacia resulted in the highest yield of alkyl esters. Lipase from Pseudomonas cepacia was further investigated in immobilized form within a chemically inert, hydrophobic sol-gel support. The gel-entrapped lipase was prepared by polycondensation of hydrolyzed tetramethoxysilane and iso-butyltrimethoxysilane. Using the immobilized lipase PS, the effects of water and alcohol concentration, enzyme loading, enzyme thermal stability, and temperature in the transesterification reaction were investigated. The optimal conditions for processing 10 g of soybean oil were: 35 {sup o}C, 1:7.5 oil/methanol molar ratio, 0.5 g water and 475 mg lipase for the reactions with methanol, and 35 {sup o}C, 1:15.2 oil/ethanol molar ratio, 0.3 g water, 475 mg lipase for the reactions with ethanol. Subject to the optimal conditions, methyl and ethyl esters formation of 67 and 65 mol% in 1 h of reaction were obtained for the immobilized enzyme reactions. Upon the reaction with the immobilized lipase, the triglycerides reached negligible levels after the first 30 min of the reaction and the immobilized lipase was consistently more active than the free enzyme. The immobilized lipase also proved to be stable and lost little activity when subjected to repeated uses. (author)

  19. Optimized immobilization of lectins using self-assembled monolayers on polysilicon encoded materials for cell tagging.

    Science.gov (United States)

    Penon, Oriol; Siapkas, Dimitrios; Novo, Sergi; Durán, Sara; Oncins, Gerard; Errachid, Abdelhamid; Barrios, Lleonard; Nogués, Carme; Duch, Marta; Plaza, José Antonio; Pérez-García, Lluïsa

    2014-04-01

    Self-assembled monolayers (SAMs) have been used for the preparation of functional microtools consisting of encoded polysilicon barcodes biofunctionalized with proteins of the lectin family. These hybrid microtools exploit the lectins ability for recognizing specific carbohydrates of the cell membrane to give an efficient system for cell tagging. This work describes how the control of the methodology for SAM formation on polysilicon surfaces followed by lectin immobilization has a crucial influence on the microtool biofunction. Several parameters (silanization time, silane molar concentration, type of solvent or deposition methodology) have been studied to establish optimal function. Furthermore, silanes incorporating different terminal groups, such as aldehyde, activated ester or epoxide groups were tested in order to analyze their chemical coupling with the biomolecules, as well as their influence on the biofunctionality of the immobilized protein. Two different lectins - wheat germ agglutinin (WGA) and phytohemagglutinin (PHA-L) - were immobilized, because they have different and specific cell recognition behaviour and exhibit different cell toxicity. In this way we can assess the effect of intrinsic bulk toxicity with that of the cell compatibility once immobilized as well as the importance of cell affinity. A variety of nanometrical techniques were used to characterize the active surfaces, and lectin immobilization was quantified using ultraviolet-visible absorption spectroscopy (UV-vis) and optical waveguide light mode spectroscopy (OWLS). Once the best protocol was found, WGA and PHA were immobilized on polysilicon coded barcodes, and these microtools showed excellent cell tagging on living mouse embryos when WGA was used.

  20. A novel approach for efficient immobilization and stabilization of papain on magnetic gold nanocomposites.

    Science.gov (United States)

    Sahoo, Banalata; Sahu, Sumanta Kumar; Bhattacharya, Dipsikha; Dhara, Dibakar; Pramanik, Panchanan

    2013-01-01

    In the present study, a facile functionalization of magnetic nanoparticles has been described for the immobilization of enzyme that offers many advantages for reuse and excellent efficiencies. The magnetic gold nanocomposites have been fabricated for the successful immobilization of an industrially important enzyme "papain". For immobilization of papain on magnetic gold nanocomposites, magnetic nanoparticles were modified with 3-(mercaptopropyl) trimethoxy silane (MPTS). Further, the citrate stabilized gold nanoparticles were chemisorbed on these thiol coated magnetic nanoparticles to fabricate the desired magnetic gold nanocomposites. Papain containing net positive charge (isoelectric point of papain=8.75) in PBS buffer (pH 7.4) has immobilized on the surface of the negatively charged magnetic gold nanocomposites through the ionic or electrostatic interaction. The Michaelis-Menten kinetic constant (K(m)) and maximum reaction velocity (V(max)) for free papain were 0.236×10(5) g ml(-1) and 4.08 g ml(-1)/s respectively whereas for immobilized papain, K(m) and V(max) values were 0.308×10(5) g ml(-1) and 5.4 g ml(-1)/s respectively. The loading amount of papain on magnetic gold nanocomposites was 54 mg/g support and the activity recovery of the immobilized papain reached to 47 (±5)% compared to native papain. The main advantage of this papain nanobiocatalyst is the easy isolation of enzyme from the reaction medium.

  1. Immobilization of denatured DNA to macroporous supports: I. Efficiency of different coupling procedures.

    Science.gov (United States)

    Bünemann, H; Westhoff, P; Herrmann, R G

    1982-11-25

    Methods commonly used for covalent immobilization of single stranded DNA have been applied to several solid supports (Sephadex G-25 and Cellex 410) as well as to a number of macroporous materials (Sepharose C1-6B, C1-2B; Sephacryl S-500 and S-1000). Coupling efficiencies and stability of covalently bound DNA are compared for both classes of materials. The yields of the immobilization reaction for sonicated DNA are only 10-40% for G-25 and Cellex 410 in contrast to 60-80% for C1-6B and S-500. Under optimal conditions, up to 0.5 mg of DNA can be coupled initially per g of wet macroporous material. The immobilized DNAs are lost from the supports in a biphasic manner, with about 10-20% loss per day during the first 2-3 days at 45 degrees C, followed by only about 1% loss per day at the same temperature thereafter. The influence of the coupling procedure on the generation of mismatch effects has been studied in 2.4 M tetraethylammonium chloride solution for the hybrid formation between immobilized and mobile DNA. The degree of mismatch ranged from 0-3% and depended on the method of immobilization. The unspecific absorption of DNA on macroporous materials is sufficiently low to allow efficient hybrid selection. No size limitations have been observed when plastid mRNAs are selected by cloned fragments of plastid DNA immobilized to macroporous Sephacryl S-500.

  2. The use of PAMAM dendrimers as a platform for laccase immobilization: kinetic characterization of the enzyme.

    Science.gov (United States)

    Cardoso, Franciane Pinheiro; Aquino Neto, Sidney; Ciancaglini, Pietro; de Andrade, Adalgisa R

    2012-08-01

    The kinetic behavior of the enzyme laccase in solution and immobilized onto carbon platforms using poly(amido amine) (PAMAM) dendrimers has been investigated. The results with the immobilized enzymes have demonstrated that almost ten times more enzyme on the carbon support is required for satisfactory kinetic rates to be achieved. Furthermore, the study as a function of the substrate concentration revealed that the kinetic behavior of the enzyme in solution fits the Michaelis-Menten model. However, when the enzyme is immobilized onto the carbon surface, the catalyzed reaction follows a particular kinetic behavior with apparent positive cooperativity. The highest activity with laccase (in solution or immobilized) is achieved around pH 4.5, and the substrate conversion rate clearly diminishes with rising pH. The optimum temperature lies around 60 °C. The enzyme displays good catalytic activity in a wide range of pH and temperature values. The stability tests evidenced that there is no appreciable reduction in the enzymatic activity after immobilization within the first 30 days. Taking into account both the kinetic and stability tests, one can infer that the use of PAMAM dendrimers seems to be a very attractive approach for the immobilization of enzymes, as well as a feasible and useful methodology for the anchoring of enzymes with potential application in many biotechnological areas.

  3. Incomplete restoration of immobilization induced softening of young beagle knee articular cartilage after 50-week remobilization.

    Science.gov (United States)

    Haapala, J; Arokoski, J; Pirttimäki, J; Lyyra, T; Jurvelin, J; Tammi, M; Helminen, H J; Kiviranta, I

    2000-01-01

    The aim of this study was to characterize the biomechanical and structural changes in canine knee cartilage after an initial 11-week immobilization and subsequent remobilization period of 50 weeks. Cartilage from the immobilized and remobilized knee was compared with the tissue from age-matched control animals. Compressive stiffness, in the form of instant shear modulus (ISM) and equilibrium shear modulus (ESM) of articular cartilage, was investigated using an in situ indentation creep technique. The local variations in cartilage of glycosaminoglycan (GAG) concentration were measured with a microspectrophotometer after safranin O staining of histological sections. Using a computer-based quantitative polarized light microscopy method, collagen-related optical retardation, gamma, of cartilage zones were performed to investigate the collagen network of cartilage. Macroscopically, cartilage surfaces of the knee joint remained intact both after immobilization and remobilization periods. Immobilization caused significant softening of the lateral femoral and tibial cartilages, as expressed by ESM (up to 30%, p test points. The changes of ESM were positively correlated with the alterations in GAG content of the superficial and deep zones after immobilization and remobilization. This confirms the key role of protoglycans in the regulation of the equilibrium stiffness of articular cartilage. As a conclusion, immobilization of the joint of a young individual may cause long-term, if not permanent, alterations of cartilage biomechanical properties. This may predispose joint to degenerative changes later in life.

  4. Facile, high efficiency immobilization of lipase enzyme on magnetic iron oxide nanoparticles via a biomimetic coating

    Directory of Open Access Journals (Sweden)

    He Lihong

    2011-06-01

    Full Text Available Abstract Background Immobilization of lipase on appropriate solid supports is one way to improve their stability and activity, and can be reused for large scale applications. A sample, cost- effective and high loading capacity method is still challenging. Results A facile method of lipase immobilization was developed in this study, by the use of polydopamine coated magnetic nanoparticles (PD-MNPs. Under optimal conditions, 73.9% of the available lipase was immobilized on PD-MNPs, yielding a lipase loading capacity as high as 429 mg/g. Enzyme assays revealed that lipase immobilized on PD-MNPs displayed enhanced pH and thermal stability compared to free lipase. Furthermore, lipase immobilized on PD-MNPs was easily isolated from the reaction medium by magnetic separation and retained more than 70% of initial activity after 21 repeated cycles of enzyme reaction followed by magnetic separation. Conclusions Immobilization of enzyme onto magnetic iron oxide nanoparticles via poly-dopamine film is economical, facile and efficient.

  5. Coupled reactions of immobilized enzymes and immobilized substrates: clinical application as exemplified by amylase assay.

    Science.gov (United States)

    Barabino, R C; Gray, D N; Keyes, M H

    1978-08-01

    We described a partitioned enzyme-sensor system, which incorporates an immoblized substrate and three or more discrete immobilized enzymes. This instrument measures alpha-amylase activity by passing the solution containing alpha-amylase over a column packed with immobilized starch. The resulting oligosaccharides are successively exposed to a column or columns containing immobolized glucose oxidase, catalase, glucoamylase or maltase, and glucose oxidase. The resulting hydrogen peroxide is detected by a three-electrode amperometric cell. All immobilized reagents were immobilized on a particulate, porous alumina to allow rapid and constant flow rate. With use of less than optimum immobilized reagents, alpha-amylase activity has been measured from about 5 to 200 kU/liter with a 50 microliter sample size. Lack of sensitivity is predominantly attributable to the low activity and low stability of immobilized maltase and glucoamylase. We believe that a clinical test using this system is feasible and desirable because the immobilized reagent system should allow for testing of alpha-amylase with excellent precision, convenience to the operator, and low cost.

  6. Immobilization of the α-amylase of Bacillus amyloliquifaciens TSWK1-1 for the improved biocatalytic properties and solvent tolerance.

    Science.gov (United States)

    Kikani, B A; Pandey, S; Singh, S P

    2013-05-01

    The α-amylase of Bacillus amyloliquifaciens TSWK1-1 (GenBank Number, GQ121033) was immobilized by various methods, including ionic binding with DEAE cellulose, covalent coupling with gelatin and entrapment in polyacrylamide and agar. The immobilization of the purified enzyme was most effective with the DEAE cellulose followed by gelatin, agar and polyacrylamide. The K m increased, while V max decreased upon immobilization on various supports. The temperature and pH profiles broadened, while thermostability and pH stability enhanced after immobilization. The immobilized enzyme exhibited greater activity in various non-ionic surfactants, such as Tween-20, Tween-80 and Triton X-100 and ionic surfactant, SDS. Similarly, the enhanced stability of the immobilized α-amylase in various organic solvents was among the attractive features of the study. The reusability of the immobilized enzyme in terms of operational stability was assessed. The DEAE cellulose immobilized α-amylase retained its initial activity even after 20 consequent cycles. The DEAE cellulose immobilized enzyme hydrolyzed starch with 27 % of efficiency. In summary, the immobilization of B. amyloliquifaciens TSWK1-1 α-amylase with DEAE cellulose appeared most suitable for the improved biocatalytic properties and stability.

  7. Optimization of Two-species Whole-cell Immobilization System Constructed with Marine-derived Fungi and Its Biological Degradation Ability

    Institute of Scientific and Technical Information of China (English)

    陈慧英; 王明霞; 沈煜斌; 姚善泾

    2014-01-01

    Mycelia pellet formed spontaneously in the process of cultivation was exploited as a biological carrier for whole-cell immobilization due to its unique structural characteristic. An innovative two-species whole-cell im-mobilization system was achieved by inoculating the marine-derived fungus Pestalotiopsis sp. J63 spores into cul-ture medium containing another fungus Penicillium janthinellum P1 pre-grown mycelia pellets for 2 days without any pretreatment. In order to evaluate the biological degradation capacity of this novel constructed immobilization system, the immobilized pellets were applied to treat paper mill effluent and decolorize dye Azure B. The use of the constructed immobilization system in the effluent resulted in successful and rapid biodegradation of numerous in-soluble fine fibers. The optimum conditions of immobilized procedure for maximum biodegradation capacity were determined using orthogonal design with biomass of P1 pellets 10 g (wet mass), concentration of J63 spore 2×109 ml-1, and immobilization time 2 d. The results demonstrate that immobilized pellets have more than 99%biodegra-dation capacity in a ten-hour treatment process. The kinetics of biodegradation fits the Michaelis-Menten equation well. Besides, the decolorization capability of immobilized pellets is more superior than that of P1 mycelia pellets. Overall, the present study offers a simple and reproducible way to construct a two-species whole-cell immobiliza-tion system for sewage treatment.

  8. [The combined action of drinking mineral water and low-intensity electromagnetic radiation under the immobilization stress conditions (an experimental study)].

    Science.gov (United States)

    Korolev, Yu N; Bobrovnitsky, I P; Geniatulina, M S; Mikhailik, L V; Nikulina, L A; Bobkova, A S; Yakovlev, M Yu

    2015-01-01

    The present study carried out on white male rats in experiments with the use of biochemical, radioimmunological, and electron- microscopic methods. It was shown that the combined treatment with potable mineral water (MV) and low-intensity electromagnetic radiation (LIEMR) of ultrahigh frequency (power density less than 1 pW/cm2, the frequency about 1000 MHz) facilitated the activation of metabolic and intracellular regenerative processes in the liver and testes. One of the advantages of the combined application of MV and LIEMR over the single-factor treatment manifested itself as the weakening of stress reactions, the increase in the frequency of the plastic processes, and the more harmonious development of different forms of intracellular regeneration. The results of the study provide a deeper insight ino the mechanisms underlying the combined actions of drinking mineral water and low-intensity electromagnetic radiation; also, they justify the application of these factors for the protection of the reproductive system and the entire body from stress-induced disorders.