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Sample records for cells immobilized

  1. Immobilized cells in meat fermentation.

    Science.gov (United States)

    McLoughlin, A J; Champagne, C P

    1994-01-01

    The immobilization of microbial cells can contribute to fermented meat technology at two basic levels. First, the solid/semisolid nature (low available water) of the substrate restricts the mobility of cells and results in spatial organizations based on "natural immobilization" within the fermentation matrix. The microniches formed influence the fermentation biochemistry through mass transfer limitations and the subsequent development and activity of the microflora. This form of immobilization controls the nature of competition between subpopulations within the microflora and ultimately exerts an effect on the ecological competence (ability to survive and compete) of the various cultures present. Second, immobilized cell technology (ICT) can be used to enhance the ecological competence of starter cultures added to initiate the fermentation. Immobilization matrices such as alginate can provide microniches or microenvironments that protect the culture during freezing or lyophilization, during subsequent rehydration, and when in competition with indigenous microflora. The regulated release of cells from the microenvironments can also contribute to competitive ability. The regulation of both immobilization processes can result in enhanced fermentation activity. PMID:8069934

  2. Alcohol dehydrogenase activity in immobilized yeast cells

    International Nuclear Information System (INIS)

    A method for the immobilization of Saccharomyces cerevisiae was developed and the activity of alcohol dehydrogenase of the immobilized cells was determined. The treatment of the yeast cells with 1 % toluene followed by irradiation with acrylamide and bisacrylamide resulted in a high activity of alcohol dehydrogenase in the immobilized cells. The enzyme of the immobilized cells was stable in the pH range of 7.5 - 8.0 and the optimum pH opposed to be 8.5. Although the immobilized cells showed a rather low level of thermostability, it is suggested that they could be used for a long period of time at a temperature of 27 deg C. The immobilized cells did not exhibit any loss in the enzyme activity when stored at 4 deg C or -20 deg C. (author)

  3. Immobilization of cells for use as biocatalysts

    Energy Technology Data Exchange (ETDEWEB)

    Vojtisek, V.; Jirku, V.; Krumphanzl, V.; Culik, K.

    1983-07-21

    Bacterial cells and cells of higher organisms are immobilized on polymers, either as whole cells, cell fragments, or subcellular components. This immobilization is used for stabilization of their various enzymic activities, which are of commercial interest, e.g. for the enzymes themselves, for alkaloid production, for hormone transformations, or for various fermentations. Thus, Sedipur CL-930 was polymerized in the presence of glutaraldehyde and the polymer was incubated with Alcaligenes metalcaligenes cells for immobilization. The nonimmobilized cells contained an aspartate ammonia-lyase activity of 550 mumol L-aspartate converted/min/g, and the immobilized cells contained an activity of 420 or 500 mumol aspartate/min/g when the polymer used was made with 2 different ratios of Sedipur to glutaraldehyde. The immobilized cell product had the form of defined platelets (lamellae) with a diameter of 100-600 mum, depending on the Sedipur/glutaraldehyde ratio. In other procedures, cells were permeabilized with tensides and/or organic solvents after the immobilization. Other cells immobilized included yeast, fungi, and plant cells. The activities which were examined included glycolytic enzymes, penicillin acylase, L-asparagine amidohydrolase and production of alkaloids and phytosterols from Solanum aviculare.

  4. Metabolic Responses of Bacterial Cells to Immobilization.

    Science.gov (United States)

    Żur, Joanna; Wojcieszyńska, Danuta; Guzik, Urszula

    2016-01-01

    In recent years immobilized cells have commonly been used for various biotechnological applications, e.g., antibiotic production, soil bioremediation, biodegradation and biotransformation of xenobiotics in wastewater treatment plants. Although the literature data on the physiological changes and behaviour of cells in the immobilized state remain fragmentary, it is well documented that in natural settings microorganisms are mainly found in association with surfaces, which results in biofilm formation. Biofilms are characterized by genetic and physiological heterogeneity and the occurrence of altered microenvironments within the matrix. Microbial cells in communities display a variety of metabolic differences as compared to their free-living counterparts. Immobilization of bacteria can occur either as a natural phenomenon or as an artificial process. The majority of changes observed in immobilized cells result from protection provided by the supports. Knowledge about the main physiological responses occurring in immobilized cells may contribute to improving the efficiency of immobilization techniques. This paper reviews the main metabolic changes exhibited by immobilized bacterial cells, including growth rate, biodegradation capabilities, biocatalytic efficiency and plasmid stability. PMID:27455220

  5. Metabolic Responses of Bacterial Cells to Immobilization

    Directory of Open Access Journals (Sweden)

    Joanna Żur

    2016-07-01

    Full Text Available In recent years immobilized cells have commonly been used for various biotechnological applications, e.g., antibiotic production, soil bioremediation, biodegradation and biotransformation of xenobiotics in wastewater treatment plants. Although the literature data on the physiological changes and behaviour of cells in the immobilized state remain fragmentary, it is well documented that in natural settings microorganisms are mainly found in association with surfaces, which results in biofilm formation. Biofilms are characterized by genetic and physiological heterogeneity and the occurrence of altered microenvironments within the matrix. Microbial cells in communities display a variety of metabolic differences as compared to their free-living counterparts. Immobilization of bacteria can occur either as a natural phenomenon or as an artificial process. The majority of changes observed in immobilized cells result from protection provided by the supports. Knowledge about the main physiological responses occurring in immobilized cells may contribute to improving the efficiency of immobilization techniques. This paper reviews the main metabolic changes exhibited by immobilized bacterial cells, including growth rate, biodegradation capabilities, biocatalytic efficiency and plasmid stability.

  6. 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 ®}.

  7. 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®.

  8. Immobilization of microbial cells containing NAD-kinase

    Energy Technology Data Exchange (ETDEWEB)

    Hayashi, T.; Tanaka, Y.; Kawashima, K.

    1979-06-01

    Microbial cells having NAD-kinase activity, Brevibacterium ammoniagenes, were immobilized by the radiation-copolymerization method under low temperature with the activity recovery of more than 80%. Compared to the native microbial cells the immobilized cells were more stable against heat and pH change. The immobilized cells were subjected to the 5 hr reaction repeatedly 20 times without any activity loss.

  9. Immobilization of yeast cells by radiation-induced polymerization

    International Nuclear Information System (INIS)

    Radiation-induced polymerization method was applied to the immobilization of yeast cells. The effects of irradiation, cooling and monomer, which are neccessary for polymerization, were recovered completely by subsequent aerobical incubation of yeast cells. The ethanol productive in immobilized yeast cells increased with the increase of aerobical incubation period. The growth of yeast cells in immobilized yeast cells was indicated. The maximum ethanol productivity in immobilized yeast cell system was around three times as much as that in free yeast cell system. (orig.)

  10. Smooth Muscle Cell Functionality on Collagen Immobilized Polycaprolactone Nanowire Surfaces

    Directory of Open Access Journals (Sweden)

    Victoria Leszczak

    2014-05-01

    Full Text Available Inhibition of smooth muscle cell (SMC proliferation and preservation of a differentiated state are important aspects in the management, avoidance and progression of vascular diseases. An understanding of the interaction between SMCs and the biomaterial involved is essential for a successful implant. In this study, we have developed collagen immobilized nanostructured surfaces with controlled arrays of high aspect ratio nanowires for the growth and maintenance of human aortic SMCs. The nanowire surfaces were fabricated from polycaprolactone and were immobilized with collagen. The objective of this study is to reveal how SMCs interact with collagen immobilized nanostructures. The results indicate significantly higher cellular adhesion on nanostructured and collagen immobilized surfaces; however, SMCs on nanostructured surfaces exhibit a more elongated phenotype. The reduction of MTT was significantly lower on nanowire (NW and collagen immobilized NW (colNW surfaces, suggesting that SMCs on nanostructured surfaces may be differentiated and slowly dividing. Scanning electron microscopy results reveal that SMCs on nanostructured surfaces are more elongated and that cells are interacting with the nano-features on the surface. After providing differentiation cues, heavy chain myosin and calponin, specific to a contractile SMC phenotype, are upregulated on collagen immobilized surfaces. These results suggest that nanotopography affects cell adhesion, proliferation, as well as cell elongation, while collagen immobilized surfaces greatly affect cell differentiation.

  11. Uranium uptake by immobilized cells of Pseudomonas strain EPS 5028

    International Nuclear Information System (INIS)

    Polyacrylamide-gel-immobilized cells of Pseudomonas strain EPS 5028 were effective in the removal of uranium (U) from synthetic effluents. Metal accumulation was performed in an open system in columns filled with immobilized cells that were challenged with continuous flows containing U. Possible variable of the system were studied. Uranium uptake by the immobilized cells of this microorganism was affected by pH but not by temperature or flow rate. In addition, U binding could be interpreted in terms of the Freundlich adsorption isotherm indicating single-layer adsorption. The feasibility of reusing the immobilized cells was suggested after the recovery of U with a solution of 0.1 M sodium carbonate. (orig.)

  12. Continuous culture of immobilized streptomyces cells for kasugamycin production.

    Science.gov (United States)

    Kim, C J; Chang, Y K; Chun, G T; Jeong, Y H; Lee, S J

    2001-01-01

    Continuous cultures of immobilized Streptomyces kasugaensis, a kasugamycin producer, were carried out on Celite beads. When using a prototype separator for immobilized-cell separation and recycling, the continuous operation could not be sustained for an extended period as a result of an excessive loss of immobilized cells caused by the poor performance of the separator. Accordingly, the immobilized-cell separator was revised to provide better immobilized-cell settling and thus recycling into the reactor. In a subsequent culture using the revised separator, a stable operation was maintained for over 820 h with a high kasugamycin productivity. The kasugamycin productivity ranged from 9.8 to 16.1 mg/L/h, which was about 14- to 23-fold higher than that in a batch suspended-cell culture. When the original feeding medium concentration was doubled at the end of the continuous culture, the productivity became severely impaired for several reasons, which will be discussed. An excessive formation of free cells and loss of immobilized cells through the separator were also observed. PMID:11386865

  13. Peptide immobilized on gold particles enhances cell growth

    OpenAIRE

    Gong, Jiansheng; Ito, Yoshihiro

    2008-01-01

    A multivalent ligand of thrombopoietin (TPO) was prepared by immobilization of mimetic peptides on gold particles. An effective peptide ligand containing cysteine was designed to enhance the growth of TPO-sensitive cells. The peptide was then immobilized on gold particles by self assembly. The multivalent ligand enhanced the growth of TPO-dependent cells and its activity was more than that of the monovalent ligand.

  14. Bioreduction of chromate by immobilized cells of Halomonas sp

    OpenAIRE

    S. Murugavelh, Kaustubha Mohanty

    2013-01-01

    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 was completely utilized by the immobilized Halomonas sp even in the presence of Cr(VI) at 40 mg/L. The optimum pH for the bioreduction of Cr(V...

  15. Cell immobilization for microbial production of 1,3-propanediol.

    Science.gov (United States)

    Gungormusler-Yilmaz, Mine; Cicek, Nazim; Levin, David B; Azbar, Nuri

    2016-06-01

    Cell and enzyme immobilization are often used for industrial production of high-value products. In recent years, immobilization techniques have been applied to the production of value-added chemicals such as 1,3-Propanediol (1,3-PDO). Biotechnological fermentation is an attractive alternative to current 1,3-PDO production methods, which are primarily thermochemical processes, as it generates high volumetric yields of 1,3-PDO, is a much less energy intensive process, and generates lower amounts of environmental organic pollutants. Although several approaches including: batch, fed-batch, continuous-feed and two-step continuous-feed were tested in suspended systems, it has been well demonstrated that cell immobilization techniques can significantly enhance 1,3-PDO production and allow robust continuous production in smaller bioreactors. This review covers various immobilization methods and their application for 1,3-PDO production. PMID:25600463

  16. Comparative studies on production of Glutamic acid using wild type, mutants, immobilized cells and immobilized mutants of Corynebacterium glutamicum

    Directory of Open Access Journals (Sweden)

    Hajera Tabassum,

    2011-05-01

    Full Text Available In the present study comparative studies were carried out on glutamic acid production with wild type cells, mutants, immobilized cells and immobilized mutants of Corynebacerium glutamicum. Immobilization was carried out by sodium alginate method; physical mutagenesis was performed by U.V irradiation and chemical mutagenesis with nitrosoguanidine. Five physical mutants and five chemical mutants were selected for study. Fermentation was carried out for a period of six days at 300C at 200 rpm. Highest amount of glutamic acid was produced with immobilized chemical mutants.

  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. Enzyme production in immobilized Trichoderma reesei cells with hydrophobic polymers prepared by radiation polymerization method

    International Nuclear Information System (INIS)

    Trichoderma reesei cells were immobilized on paper covered with hydrophobic monomer, trimethylpropane triacrylate by radiation polymerization. The effect of immobilization condition on enzyme productivity was studied by measuring filter paper and cellobiose activity. The cells were adhered and grew on the surface of the carrier with the polymer giving high enzyme productivity in the immobilized cells in comparison with the free cells. Optimum concentration and volume of the coating monomer for the preparation of the immobilized cells were obtained. (author)

  19. Biodegradation of petroleum hydrocarbons in an immobilized cell airlift bioreactor

    Energy Technology Data Exchange (ETDEWEB)

    Kermanshahi Pour, A.; Karamanev, D.; Margaritis, A. [Universityn of Western Ontario, London (Canada). Dept. of Chemical and Biochemical Engineering

    2005-09-01

    An ''immobilized cell airlift bioreactor'', was used for the aerobic bioremediation of simulated diesel fuel contaminated groundwater and tested with p-xylene and naphthalene in batch and continuous regimes. The innovative design of the experiments consists of two stages. At the first stage ''immobilized soil bioreactor'' (ISBR) was used to develop an efficient microbial consortium from the indigenous microorganisms, which exist in diesel fuel contaminated soil. The concept of ISBR relies on the entrapment of the soil particles into the pores of a semi-permeable membrane, which divides the bioreactor into two aerated and non-aerated portions. The second stage involves inoculating the ''immobilized cell air lift bioreactor'' with the cultivated microbial consortia of the first stage. Immobilized cell airlift bioreactor has the same configuration as ISBR except that in this bioreactor instead of soil, microorganisms were immobilized on the fibers of the membrane. The performance of a 0.83 L immobilized cell airlift bioreactor was investigated at various retention time (0.5-6 h) and concentrations of p-xylene (15, 40 and 77 mg/L) and naphthalene (8, 15 and 22 mg/L) in the continuous operation. In the batch regime, 0.9 L bioreactor was operated at various biodegradation times (15-135 min) and concentrations of p-xylene (13.6, 44.9 and 67.5 mg/L) and naphthalene (1.5 and 3.8 mg/L). Under the conditions of the complete biodegradation of p-xylene and naphthalene, the obtained volumetric biodegradation rates at biomass density of 720 mg/L were 15 and 16 mg/L h, respectively. (author)

  20. The Metabolic Synchronization of Immobilized Yeast Cells: Effect of Matrices

    Czech Academy of Sciences Publication Activity Database

    Bolyó, Juraj; Mair, T.; Kuncová, Gabriela

    -: -, 2009, s. 1-1. ISBN N. [Conference on Functional Dynamics. Cascais (PT), 02.03.2009-05.03.2009] R&D Projects: GA MŠk OC 121 Institutional research plan: CEZ:AV0Z40720504 Keywords : yeast * immobilized yeast cells Subject RIV: CE - Biochemistry

  1. Immobilization of chlorine dioxide modified cells for uranium absorption

    International Nuclear Information System (INIS)

    There has been a trend towards the use of microorganisms to recover metals from industrial wastewater, for which various methods have been reported to be used to improve microorganism adsorption characteristics such as absorption capacity, tolerance and reusability. In present study, chlorine dioxide(ClO2), a high-efficiency, low toxicity and environment-benign disinfectant, was first reported to be used for microorganism surface modification. The chlorine dioxide modified cells demonstrated a 10.1% higher uranium adsorption capacity than control ones. FTIR analysis indicated that several cell surface groups are involved in the uranium adsorption and cell surface modification. The modified cells were further immobilized on a carboxymethylcellulose (CMC) matrix to improve their reusability. The cell-immobilized adsorbent could be employed either in a high concentration system to move vast UO22+ ions or in a low concentration system to purify UO22+ contaminated water thoroughly, and could be repeatedly used in multiple adsorption-desorption cycles with about 90% adsorption capacity maintained after seven cycles. - Highlights: • Chlorine dioxide was first reported to be used for microorganism surface modification. • The chlorine dioxide modified cells demonstrated a 10.1% higher uranium adsorption capacity than control ones. • The chlorine dioxide modified cells were further immobilized by carboxymethylcellulose to improve their reusability

  2. Immobilized cell technology in beer brewing: Current experience and results

    OpenAIRE

    Leskošek-Čukalov Ida J.; Nedović Viktor A.

    2005-01-01

    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 sit...

  3. A study on immobilized ethanol yeast cells by radiation technique

    International Nuclear Information System (INIS)

    Hydrophilic monomer 2-hydroxyethyl acrylate (HEA) and a series of polyethylene glycol dimethacrylate monomers were copolymerized by radiation technique at low temperature (-78 degree C) and hydrophilic hydrogels were obtained. The immobilization of yeast cells with these copolymer carriers led to a higher ethanol productivity than free cells. Of all copolymer carriers, the ethanol yield with poly (HEA-14 G) was the highest, about 2.45 times as high as that of free yeast cells. In addition, the ethanol productivity of 12 batch repeated reactions with poly (HEA-14G) carrier was all higher than that of free yeast cells. The ethanol productivity of immobilized yeast cells was dependent on the proportion of hydrophilic monomer to other monomers in copolymer systems, the chain length of the bifunctional monomer, the degree of hydration of copolymer carriers, the structure of copolymer carriers and porosity in the internal structure of carriers. The ethanol yield of immobilized cells depended on swelling ability and porosity of copolymer carriers

  4. Continuous glutamate production using an immobilized whole-cell system

    Energy Technology Data Exchange (ETDEWEB)

    Kim, H.S.; Ryu, D.D.Y.

    1982-10-01

    For the purpose of saving the energy and raw materials required in a glutamate fermentation, an immobilized whole-cell system was prepared and its performance in a continuous reactor system was evaluated. Corynebacterium glutamicum (a mutant strain of ATCC 13058) whole cell was immobilized in k-carrageenan matrix and the gel structure was strengthened by treatment with a hardening agent. The effective diffusivities of carrageenan gel for glucose and oxygen were formed to decrease significantly with an increase in carrageenan concentration, while the gel strength showed an increasing trend. Based on the physical and chemical properties of carrageenan gel, the immobilized method was improved and the operation of the continuous reactor system was partially optimized. In an air-stirred fermentor, the continuous production of glutamate was carried out. The effect of the dilution rate of glutamate production and operation stability was investigated. The performance of the continuous wbole-cell reactor system was evaluated by measuring glutamate productivity for a period of 30 days; it was found to be far superior to the performance of convention batch reactor systems using free cells.

  5. 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.

  6. Bioreduction of chromate by immobilized cells of Halomonas sp

    Directory of Open Access Journals (Sweden)

    S. Murugavelh, Kaustubha Mohanty

    2013-01-01

    Full Text Available 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 was completely utilized by the immobilized Halomonas sp even in the presence of Cr(VI at 40 mg/L. 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. 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.

  7. Immobilization of trichoderma REESEI (QM 9414) cells with paper covered with ionic copolymer by radiation polymerization

    International Nuclear Information System (INIS)

    Cationic-hydrophobic copolymer and anionic-hydrophobic copolymer was covered onto surface of paper by radiation polymerization. The paper covered with ionic copolymer was used as carrier of immobilizing Trichoderma reesei cells. Results showed that the cells were immobilized firmly on the carriers and not dislocated from the carriers by shaking. All of FPA of the cells immobilized with the carriers covered with cationic copolymer were higher than that of un-immobilized free cells. The carriers covered with anionic copolymer showed good effect on immobilization of the cells. The weight of immobilized cells increase as increasing the component of DEAEMA in poly (DEAEMA-ATMPT) or decreasing the component of AA in poly (AA-ATMPT). It also increase with the increase of water absorption in poly (DEAEMA-ATMPT) or decrease of water absorption in poly (AA-ATMPT). It shows the static interaction play an important role in the immobilization of cells with ionic copolymer materials

  8. Protein-free cell culture on an artificial substrate with covalently immobilized insulin.

    OpenAIRE

    Ito, Y.; Zheng, J.; Imanishi, Y.; Yonezawa, K; Kasuga, M.

    1996-01-01

    Insulin was immobilized on a surface-hydrolyzed poly(methyl methacrylate) film. Chinese hamster ovary cells overexpressing human insulin receptors were cultured on the film in the absence of serum or soluble proteins. Small amounts of immobilized insulin (1-10% of the required amount of free insulin) were sufficient to stimulate cell proliferation. In addition, the maximal mitogenic effect of immobilized insulin was greater than that of free insulin. Immobilized insulin activated the insulin ...

  9. Smooth Muscle Cell Functionality on Collagen Immobilized Polycaprolactone Nanowire Surfaces

    OpenAIRE

    Victoria Leszczak; Baskett, Dominique A.; Popat, Ketul C.

    2014-01-01

    Inhibition of smooth muscle cell (SMC) proliferation and preservation of a differentiated state are important aspects in the management, avoidance and progression of vascular diseases. An understanding of the interaction between SMCs and the biomaterial involved is essential for a successful implant. In this study, we have developed collagen immobilized nanostructured surfaces with controlled arrays of high aspect ratio nanowires for the growth and maintenance of human aortic SMCs. The nanow...

  10. Immobilization of microbial cell and yeast cell and its application to biomass conversion using radiation techniques

    International Nuclear Information System (INIS)

    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. (author)

  11. 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.

  12. Immobilization of yeast cells with various porous carriers by radiation-induced polymerization

    International Nuclear Information System (INIS)

    Yeast cells were immobilized by radiation-induced polymerization in twice. Various kinds of porous polymer carriers were prepared by radiation-induced polymerization of glass-forming monomers at a low temperature. Precultured yeast cells were incubated aerobically at 300C with these porous carriers for 24 h. Porous carriers with yeast cells were immersed in low concentration monomer solution. Yeast cells were immobilized by radiation-induced polymerization. The maximum ethanol productivity in immobilized yeast system was around 10 times as much as that in free yeast cell system. High activity of immobilized yeast cells was maintained more than 480 h. The growth of yeast cells in immobilized yeast cells during aerobical incubation was indicated. Immobilized yeast cells thus grown were incubated for fermentation reaction. In this immobilized system, 100% of glucose was converted to ethanol, that is 100% ethanol yield was obtained, within 180 min. In free cell system, only 15% ethanol yield was obtained within 180 min. These results indicates clearly the superiority of immobilized growing cell. Yeast cells were also immobilized with non woven material as carrier by radiation-induced polymerization. The relationship between pore size of non woven material and activity in immobilized yeast cells was made clear. (author)

  13. Immobilization of yeast cells with hydrophilic carrier by radiation-induced polymerization

    International Nuclear Information System (INIS)

    Radiation-induced polymerization method was applied to the immobilization of yeast cells. The effects of irradiation, cooling and monomer, which are necessary for polymerization, were recovered completely by subsequent aerobical incubation of yeast cells. The ethanol productivity in immobilized yeast cells increased with the increase of aerobical incubation period. The growth of yeast cells in immobilized yeast cells was indicated. The maximum ethanol productivity in immobilized yeast cell system was around three times as much as that in free yeast cell system. (author)

  14. Immobilization of yeast cells with copolymer by radiation polymerization of hydrophilic and hydrophobic monomers

    International Nuclear Information System (INIS)

    The immobilization of yeast cells was carried out by using the copolymer produced by radiation polymerization of hydroxyethyl acrylate (HEA) and glyciolyl methacrylate (GMA) monomer at -78 degree C low temperature. The immobilized cells with the copolymer, poly (HEA-GMA) had higher ethanol productivity than free cells. However, the ethanol productivity of immobilized cells varied with the composition of copolymer, in which the ethanol productivity of immobilized yeast cells with the copolymer from 17% HEA and 6% GMA was the highest, 29 mg/ml · h, increasing by 3 times in comparison with that of free cells. And it was obvious that the activity of immobilized yeast cells was higher when the concentration of monomer was 20-30%. The relation between the properties of copolymer and the ethanol productivity of immobilized yeast cells was also investigated

  15. A response calculus for immobilized T cell receptor ligands

    DEFF Research Database (Denmark)

    Andersen, P S; Menné, C; Mariuzza, R A;

    2001-01-01

    To address the molecular mechanism of T cell receptor (TCR) signaling, we have formulated a model for T cell activation, termed the 2D-affinity model, in which the density of TCR on the T cell surface, the density of ligand on the presenting surface, and their corresponding two-dimensional affini...... affinity in solution, are of optimal two-dimensional affinity thereby allowing effective TCR binding under physiological conditions, i.e. at low ligand densities in cellular interfaces....... determine the level of T cell activation. When fitted to T cell responses against purified ligands immobilized on plastic surfaces, the 2D-affinity model adequately simulated changes in cellular activation as a result of varying ligand affinity and ligand density. These observations further demonstrated the...

  16. 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. PMID:25277269

  17. Metal organic frameworks for enzyme immobilization in biofuel cells

    Science.gov (United States)

    Bodell, JaDee

    Interest in biofuel cells has been rapidly expanding as an ever-growing segment of the population gains access to electronic devices. The largest areas of growth for new populations using electronic devices are often in communities without electrical infrastructure. This lack of infrastructure in remote environments is one of the key driving factors behind the development of biofuel cells. Biofuel cells employ biological catalysts such as enzymes to catalyze oxidation and reduction reactions of select fuels to generate power. There are several benefits to using enzymes to catalyze reactions as compared to traditional fuel cells which use metal catalysts. First, enzymes are able to catalyze reactions at or near room temperature, whereas traditional metal catalysts are only efficient at very high temperatures. Second, biofuel cells can operate under mild pH conditions which is important for the eventual design of safe, commercially viable devices. Also, biofuel cells allow for implantable and flexible technologies. Finally, enzymes exhibit high selectivity and can be combined to fully oxidize or reduce the fuel which can generate several electrons from a single molecule of fuel, increasing the overall device efficiency. One of the main challenges which persist in biofuel cells is the instability of enzymes over time which tend to denature after hours or days. For a viable commercial biofuel cell to be produced, the stability of enzymes must be extended to months or years. Enzymes have been shown to have improved stability after being immobilized. The focus of this research was to find a metal organic framework (MOF) structure which could successfully immobilize enzymes while still allowing for electron transport to occur between the catalytic center of the enzyme and the electrode surface within a biofuel cell for power generation. Four MOF structures were successfully synthesized and were subsequently tested to determine the MOF's ability to immobilize the following

  18. A study of ethanol production of yeast cells immobilized with polymer carrier produced by radiation polymerization

    International Nuclear Information System (INIS)

    Polymer carriers, poly(hydroxyethyl acrylate(HEA)-methoxy polyethylene glycol methylacrylate (M-23G)) and poly(hydroxyethyl acrylate(HEA)-glycidyl methylacrylate (GMA)) used for the immobilization of yeast cells were prepared by radiation polymerization at low temperature. Yeast cells were immobilized through adhesion and multiplication of yeast cells. The ethanol productivity of immobilized yeast cells with these carriers was related to the monomer composition of polymers and the optimum monomer composition was 20%:10% in poly(HEA-M-23G) and 17%:6% in poly(HEA-GMA). In this case, the ethanol productivity of immobilized yeast cells was about 4 times that of cells in free system. The relationship between the activity of immobilized yeast cells and the water content of the polymer carrier were also discussed. (author)

  19. 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.)

  20. 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.

  1. The effects of cellulase on capsaicin production in freely suspended cells and immobilized cell cultures of capsicum annuum

    International Nuclear Information System (INIS)

    The effect of different concentrations of cellulase on the production of capsaicin in freely suspended cell and immobilized cell cultures of Kahramanmara pepper seeds (Capsicum annuum L.) were studied. Calluses were obtained from in vitro germinated hypocotyl explants of pepper seedlings and cell suspensions were prepared from these calluses. Immobilized cell suspension cultures with calcium alginate and free cell suspension cultures were obtained by using cell suspensions. Elicitor such as cellulase (5-30 micro g/ml), was applied both for the free and immobilized cell suspensions and control group without elicitor was prepared. The concentration of capsaicin in freely suspended cells, immobilized cells and their filtrates were identified by HPLC after extraction with ethyl acetate. It was found that the immobilization process had an increasing effect on the capsaicin accumulation. The concentration of capsaicin in the immobilized cells for both control groups and elicitor added samples was higher than the free cells. In general, capsaicin concentration in the filtrate for free cells was higher than the immobilized cells. When all the cellulase and the sampling hours were compared, the highest capsaicin concentration for the immobilized cells was determined as 362,91 micro g/ml f.w. at the 24th hour for 30 micro g/ml cellulase applied samples. (author)

  2. Immobilization of Gibberella fujikuroi cells with carriers modified by radiation polymerization

    International Nuclear Information System (INIS)

    Gibberella fujikuroi cells were immobilized on modified carriers (gauze) by using the radiation polymerization technique. The mycelium was firmly adhered to the surface of fibril covered with hydrophobic polymer, poly (diethylene glycol dimethyl acrylate) and hydrophobic-hydrophilic copolymer poly (diethylene glycol dimethyl acrylate-sodium acrylate), but it was not immobilized onto the polyethylene net, which has a similar network structure to that of the modified carrier. The weight of immobilized cells was affected by covered polymer. Gibberellic acid productivity in immobilized cells was similar to that of free cells, and the immobilized cells was of good stability. A optimum culture condition for gibberellic acid production was at pH 5.5 and under 20 ∼ 30 degree C

  3. Studies on neomycin production using immobilized cells ofS marinensis NUV-5 in various reactor configurations: A technical note

    OpenAIRE

    Srinivasulu, Bandi; Ellaiah, Poluri; Adinarayana, Kunamneni

    2003-01-01

    Stirred tank, fluidized bed, and airlift reactors produced similar neomycin activity with immobilized cells. Packed bed reactor clearly under performed, probably because of insufficient aeration or mixing. Neomycin production using immobilized cells in fermentors requires good mixing and aeration.

  4. Biodegradation of cypermethrin by immobilized cells of Micrococcus sp. strain CPN 1

    Directory of Open Access Journals (Sweden)

    Preeti N. Tallur

    2015-09-01

    Full Text Available Pyrethroid pesticide cypermethrin is a environmental pollutant because of its widespread use, toxicity and persistence. Biodegradation of such chemicals by microorganisms may provide an cost-effective method for their detoxification. We have investigated the degradation of cypermethrin by immobilized cells of Micrococcus sp. strain CPN 1 in various matrices such as, polyurethane foam (PUF, polyacrylamide, sodium alginate and agar. The optimum temperature and pH for the degradation of cypermethrin by immobilized cells of Micrococcus sp. were found to be 30 °C and 7.0, respectively. The rate of degradation of 10 and 20 mM of cypermethrin by freely suspended cells were compared with that of immobilized cells in batches and semi-continuous with shaken cultures. PUF-immobilized cells showed higher degradation of cypermethrin (10 mM and 20 mM than freely suspended cells and cells immobilized in other matrices. The PUF-immobilized cells of Micrococcus sp. strain CPN 1 were retain their degradation capacity. Thus, they can be reused for more than 32 cycles, without losing their degradation capacity. Hence, the PUF-immobilized cells of Micrococcus sp. could potentially be used in the bioremediation of cypermethrin contaminated water.

  5. Biodegradation of cypermethrin by immobilized cells of Micrococcus sp. strain CPN 1.

    Science.gov (United States)

    Tallur, Preeti N; Mulla, Sikandar I; Megadi, Veena B; Talwar, Manjunatha P; Ninnekar, Harichandra Z

    2015-01-01

    Pyrethroid pesticide cypermethrin is a environmental pollutant because of its widespread use, toxicity and persistence. Biodegradation of such chemicals by microorganisms may provide an cost-effective method for their detoxification. We have investigated the degradation of cypermethrin by immobilized cells of Micrococcus sp. strain CPN 1 in various matrices such as, polyurethane foam (PUF), polyacrylamide, sodium alginate and agar. The optimum temperature and pH for the degradation of cypermethrin by immobilized cells of Micrococcus sp. were found to be 30 °C and 7.0, respectively. The rate of degradation of 10 and 20 mM of cypermethrin by freely suspended cells were compared with that of immobilized cells in batches and semi-continuous with shaken cultures. PUF-immobilized cells showed higher degradation of cypermethrin (10 mM and 20 mM) than freely suspended cells and cells immobilized in other matrices. The PUF-immobilized cells of Micrococcus sp. strain CPN 1 were retain their degradation capacity. Thus, they can be reused for more than 32 cycles, without losing their degradation capacity. Hence, the PUF-immobilized cells of Micrococcus sp. could potentially be used in the bioremediation of cypermethrin contaminated water. PMID:26413046

  6. Production of xanthan gum by free and immobilized cells of Xanthomonas campestris and Xanthomonas pelargonii.

    Science.gov (United States)

    Niknezhad, Seyyed Vahid; Asadollahi, Mohammad Ali; Zamani, Akram; Biria, Davoud

    2016-01-01

    Production of xanthan gum using immobilized cells of Xanthomonas campestris and Xanthomonas pelargonii grown on glucose or hydrolyzed starch as carbon sources was investigated. Calcium alginate (CA) and calcium alginate-polyvinyl alcohol-boric acid (CA-PVA) beads were used for the immobilization of cells. Xanthan titers of 8.2 and 9.2g/L were obtained for X. campestris cells immobilized in CA-PVA beads using glucose and hydrolyzed starch, respectively, whereas those for X. pelargonii were 8 and 7.9 g/L, respectively. Immobilized cells in CA-PVA beads were successfully employed in three consecutive cycles for xanthan production without any noticeable degradation of the beads whereas the CA beads were broken after the first cycle. The results of this study suggested that immobilized cells are advantageous over the free cells for xanthan production. Also it was shown that the cells immobilized in CA-PVA beads are more efficient than cells immobilized in CA beads for xanthan production. PMID:26526173

  7. Immobilization of microbial cells on cellulose-polymer surfaces by radiation polymerization

    International Nuclear Information System (INIS)

    Streptomyces phaeochromogens cells were immobilized on cellulose-polymer surfaces by radiation polymerization using hydrophilic monomers and paper. The enzyme activity of immobilized cell sheets was higher than that of immobilized cell composites obtained by the usual radiation polymerization technique. The enzyme activity of the sheets was affected by monomer concentration, the thickness of paper, and the degree of polymerization of paper. The copolymerization of hydroxyethyl methacrylate and methoxytetraethyleneglycol methacrylate in the sheets led to a further increase of the enzyme activity due to the increase of the hydrophilicity of the polymer matrix. The Michaelis constant of the sheets from low monomer concentration was close to that of intact cells

  8. Comparison of Di-n-methyl Phthalate Biodegradation by Free and Immobilized Microbial Cells

    Institute of Scientific and Technical Information of China (English)

    JIAN-LONG WANG; YU-CAI YE; WEI-ZHONG WU

    2003-01-01

    Objective To compare the biodegradation of di-n-methyl pathalate by free and immobilizedmicrobial cells. Methods The enrichment and isolation technique was used to isolate themicroorganism. The PAV-entrapment method was utilized to immobilize the microorganisms. Thescanning electron microscophy (SEM) was used to observe the growth and distribution of microbialcells immobilized inside the PVA bead gels. The GC/MS method was used to identify the mainintermediates of DMP degradation. Results The microbial cells could grow quite well in PVA gel.The metabolic pathway did not change before and after immobilization of the microbial cells. Thedegradation rate of immobilized cells was higher than that of free cells. Conclusion Theimmobilized microbial cells possess advantages than free cells when applied to the biodegradation oftoxic organic pollutants.

  9. Evaluating the potential of wine-making residues and corn cobs as support materials for cell immobilization for ethanol production

    OpenAIRE

    Genisheva, Zlatina Asenova; Mussatto, Solange I.; Oliveira, J. M.; Teixeira, J. A.

    2011-01-01

    Three wine-making residues(grape seeds, skins and stems), and corn cobs were evaluated as support material for immobilization of Saccharomyces cerevisiae and the ethanol production by the immobilized cells was assessed. The main objective of this study was to find an abundant and low cost material suitable for the cells immobilization and able to be used in a next step of wine production by immobilized yeast cells. The four natural materials were used as support in two different forms: untrea...

  10. Physiological tests for yeast brewery cells immobilized on modified chamotte carrier.

    Science.gov (United States)

    Berlowska, Joanna; Kregiel, Dorota; Ambroziak, Wojciech

    2013-11-01

    In this study yeast cell physiological activity was assessed on the basis of the in situ activity of two important enzymes, succinate dehydrogenase and pyruvate decarboxylase. FUN1 dye bioconversion and cellular ATP content were also taken as important indicators of yeast cell activity. The study was conducted on six brewing yeast strains, which were either free cells or immobilized on a chamotte carrier. The experimental data obtained indicate clearly that, in most cases, the immobilized cells showed lower enzyme activity than free cells from analogous cultures. Pyruvate decarboxylase activity in immobilized cells was higher than in planktonic cell populations only in the case of the Saccharomyces pastorianus 680 strain. However, in a comparative assessment of the fermentation process, conducted with the use of free and immobilized cells, much more favorable dynamics and carbon dioxide productivity were observed in immobilized cells, especially in the case of brewing lager yeast strains. This may explain the higher total cell density per volume unit of the fermented medium and the improved resistance of immobilized cells to environmental changes. PMID:23887884

  11. Development of High-Productivity Continuous Ethanol Production using PVA-Immobilized Zymomonas mobilis in an Immobilized-Cells Fermenter

    Directory of Open Access Journals (Sweden)

    Nurhayati Nurhayati

    2015-07-01

    Full Text Available Ethanol as one of renewable energy was being considered an excellent alternative clean-burning fuel to replace gasoline. Continuous ethanol fermentation systems had offered important economic advantages compared to traditional systems. Fermentation rates were significantly improved, especially when continuous fermentation was integrated with cell immobilization techniques to enrich the cells concentration in fermentor. Growing cells of Zymomonas mobilis immobilized in polyvinyl alcohol (PVA gel beads were employed in an immobilized-cells fermentor for continuous ethanol fermentation from glucose. The glucose loading, dilution rate, and cells loading were varied in order to determine which best condition employed in obtaining both high ethanol production and low residual glucose with high dilution rate. In this study, 20 g/L, 100 g/L, 125 g/L and 150 g/L of glucose concentration and 20% (w/v, 40% (w/v and 50% (w/v of cells loading were employed with range of dilution rate at 0.25 to 1 h-1. The most stable production was obtained for 25 days by employing 100 g/L of glucose loading. Meanwhile, the results also exhibited that 125 g/L of glucose loading as well as 40% (w/v of cells loading yielded high ethanol concentration, high ethanol productivity, and acceptable residual glucose at 62.97 g/L, 15.74 g/L/h and 0.16 g/L, respectively. Furthermore, the dilution rate of 4 hour with 100 g/L and 40% (w/v of glucose and cells loading was considered as the optimum condition with ethanol production, ethanol productivity and residual glucose obtained were 49.89 g/L, 12.47 g/L/h, and 2.04 g/L, respectively. This recent study investigated ethanol inhibition as well. The present research had proved that high sugar concentration was successfully converted to ethanol. These achieved results were promising for further study.

  12. Study on immobilized yeast cells with hydrophilic polymer carrier by radiation-induced copolymerization

    International Nuclear Information System (INIS)

    Various kinds of monomers 2-hydroxyethyl methacrylate (HEMA), 2-hydroxyethyl acrylate (HEA), hydroxypropyl methacrylate (HPMA) and methoxy polyethylene glycol methylacrylate (M-23G) are copolymerized by radiation technique at low temperature (-78 degree C) and several kinds of copolymer carriers were obtained. Yeast cells are immobilized through adhesion and multiplication of yeast cells themselves on these carriers. The ethanol productivity of immobilized yeast cells with these carriers was related to the monomer composition and water content of copolymer carriers and the optimum monomer composition was 20%:10% in poly (HEA-M23G). In this case, the ethanol productivity of immobilized yeast cells was 26 mg/(ml · h), which was 4 times as high as that of free cells. Effect of adding crosslinking reagent (4G) in lower monomer composition of poly(HEA-M23G) on the ethanol productivity of immobilized cells was better than that in higher one in this work

  13. 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.

  14. Physiological tests for yeast brewery cells immobilized on modified chamotte carrier

    OpenAIRE

    Berlowska, Joanna; Kregiel, Dorota; Ambroziak, Wojciech

    2013-01-01

    In this study yeast cell physiological activity was assessed on the basis of the in situ activity of two important enzymes, succinate dehydrogenase and pyruvate decarboxylase. FUN1 dye bioconversion and cellular ATP content were also taken as important indicators of yeast cell activity. The study was conducted on six brewing yeast strains, which were either free cells or immobilized on a chamotte carrier. The experimental data obtained indicate clearly that, in most cases, the immobilized cel...

  15. Enhanced degradation of 2-nitrotoluene by immobilized cells of Micrococcus sp. strain SMN-1.

    Science.gov (United States)

    Mulla, Sikandar I; Talwar, Manjunatha P; Bagewadi, Zabin K; Hoskeri, Robertcyril S; Ninnekar, Harichandra Z

    2013-02-01

    Nitrotoluenes are the toxic pollutants of the environment because of their large scale use in the production of explosives. Biodegradation of such chemicals by microorganisms may provide an effective method for their detoxification. We have studied the degradation of 2-nitrotoluene by cells of Micrococcus sp. strain SMN-1 immobilized in various matrices such as polyurethane foam (PUF), sodium alginate (SA), sodium alginate-polyvinyl alcohol (SA-PVA), agar and polyacrylamide. The rate of degradation of 15 and 30 mM 2-nitrotoluene by freely suspended cells and immobilized cells in batches and fed-batch with shaken cultures were compared. The PUF-immobilized cells achieved higher degradation of 15 and 30 mM 2-nitrotoluene than freely suspended cells and the cells immobilized in SA-PVA, polyacrylamide, SA and agar. The PUF-immobilized cells could be reused more than 24 cycles without loosing their degradation capacity and showed more tolerance to pH and temperature changes than freely suspended cells. These results revealed the enhanced rate of degradation of 2-nitrotoluene by PUF-immobilized cells of Micrococcus sp. strain SMN-1. PMID:23153775

  16. Hydrophilic PCU scaffolds prepared by grafting PEGMA and immobilizing gelatin to enhance cell adhesion and proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Changcan; Yuan, Wenjie; Khan, Musammir; Li, Qian [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Feng, Yakai, E-mail: yakaifeng@tju.edu.cn [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Key Laboratory of Systems Bioengineering of Ministry of Education, Tianjin University, Tianjin 300072 (China); Tianjin University-Helmholtz-Zentrum Geesthacht, Joint Laboratory for Biomaterials and Regenerative Medicine, Tianjin 300072 (China); Collaborative Innovation Center of Chemical Science and Chemical Engineering (Tianjin) Tianjin 300072 (China); Yao, Fanglian [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Key Laboratory of Systems Bioengineering of Ministry of Education, Tianjin University, Tianjin 300072 (China); Tianjin University-Helmholtz-Zentrum Geesthacht, Joint Laboratory for Biomaterials and Regenerative Medicine, Tianjin 300072 (China); Zhang, Wencheng, E-mail: wenchengzhang@yahoo.com [Department of Physiology and Pathophysiology, Logistics University of Chinese People' s Armed Police Force, Tianjin 300162 (China)

    2015-05-01

    Gelatin contains many functional motifs which can modulate cell specific adhesion, so we modified polycarbonate urethane (PCU) scaffold surface by immobilization of gelatin. PCU-g-gelatin scaffolds were prepared by direct immobilizing gelatins onto the surface of aminated PCU scaffolds. To increase the immobilization amount of gelatin, poly(ethylene glycol) methacrylate (PEGMA) was grafted onto PCU scaffolds by surface initiated atom transfer radical polymerization. Then, following amination and immobilization, PCU-g-PEGMA-g-gelatin scaffolds were obtained. Both modified scaffolds were characterized by chemical and biological methods. After immobilization of gelatin, the microfiber surface became rough, but the original morphology of scaffolds was maintained successfully. PCU-g-PEGMA-g-gelatin scaffolds were more hydrophilic than PCU-g-gelatin scaffolds. Because hydrophilic PEGMA and gelatin were grafted and immobilized onto the surface, the PCU-g-PEGMA-g-gelatin scaffolds showed low platelet adhesion, perfect anti-hemolytic activity and excellent cell growth and proliferation capacity. It could be envisioned that PCU-g-PEGMA-g-gelatin scaffolds might have potential applications in tissue engineering artificial scaffolds. - Graphical abstract: PCU-g-gelatin scaffolds were prepared by direct immobilizing gelatin onto the surface of aminated PCU scaffolds (method a). To increase the immobilization amount of gelatin, PEGMAs were grafted onto the scaffold surface by SI-ATRP. PCU-g-PEGMA-g-gelatin scaffolds were prepared by method b. The gelatin modified scaffolds exhibited high hydrophilicity, low platelet adhesion, perfect anti-hemolytic activity, and excellent cell adhesion and proliferation capacity. They might have potential applications as tissue engineering scaffolds for artificial blood vessels. - Highlights: • Hydrophilic scaffolds were prepared by grafting PEGMA and immobilization of gelatins. • Grafting PEGMA enhanced the immobilization amount of gelatin

  17. Hydrophilic PCU scaffolds prepared by grafting PEGMA and immobilizing gelatin to enhance cell adhesion and proliferation

    International Nuclear Information System (INIS)

    Gelatin contains many functional motifs which can modulate cell specific adhesion, so we modified polycarbonate urethane (PCU) scaffold surface by immobilization of gelatin. PCU-g-gelatin scaffolds were prepared by direct immobilizing gelatins onto the surface of aminated PCU scaffolds. To increase the immobilization amount of gelatin, poly(ethylene glycol) methacrylate (PEGMA) was grafted onto PCU scaffolds by surface initiated atom transfer radical polymerization. Then, following amination and immobilization, PCU-g-PEGMA-g-gelatin scaffolds were obtained. Both modified scaffolds were characterized by chemical and biological methods. After immobilization of gelatin, the microfiber surface became rough, but the original morphology of scaffolds was maintained successfully. PCU-g-PEGMA-g-gelatin scaffolds were more hydrophilic than PCU-g-gelatin scaffolds. Because hydrophilic PEGMA and gelatin were grafted and immobilized onto the surface, the PCU-g-PEGMA-g-gelatin scaffolds showed low platelet adhesion, perfect anti-hemolytic activity and excellent cell growth and proliferation capacity. It could be envisioned that PCU-g-PEGMA-g-gelatin scaffolds might have potential applications in tissue engineering artificial scaffolds. - Graphical abstract: PCU-g-gelatin scaffolds were prepared by direct immobilizing gelatin onto the surface of aminated PCU scaffolds (method a). To increase the immobilization amount of gelatin, PEGMAs were grafted onto the scaffold surface by SI-ATRP. PCU-g-PEGMA-g-gelatin scaffolds were prepared by method b. The gelatin modified scaffolds exhibited high hydrophilicity, low platelet adhesion, perfect anti-hemolytic activity, and excellent cell adhesion and proliferation capacity. They might have potential applications as tissue engineering scaffolds for artificial blood vessels. - Highlights: • Hydrophilic scaffolds were prepared by grafting PEGMA and immobilization of gelatins. • Grafting PEGMA enhanced the immobilization amount of gelatin

  18. Progress on implantable biofuel cell: Nano-carbon functionalization for enzyme immobilization enhancement.

    Science.gov (United States)

    Babadi, Arman Amani; Bagheri, Samira; Hamid, Sharifah Bee Abdul

    2016-05-15

    Biofuel cells are bio-electrochemical devices, which are suitable for the environmentally friendly generation of energy. Enzymatic biofuel cell (EBFC) operates at ambient temperature and pH. Biofuel cells utilize vegetable and animal fluids (e.g. glucose) as a biofuel to produce energy. Fundamental part of each Glucose biofuel cell (GBFC) is two bioelectrodes which their surface utilizes as an enzyme immobilized site. Glucose oxidase (GOx) or glucose dehydrogenase (GDH) were immobilized on bioanode and oxidize glucose while oxygen reduced in biocathode using immobilized laccase or bilirubin oxidase in order to generate sufficient power. Glucose biofuel cells are capable to generate sufficient power for implanted devices. The key step of manufacturing a bioelectrode is the effective enzyme immobilization on the electrode surface. Due to the thin diameter of carbon nanomaterials, which make them accessible to the enzyme active sites, they are applicable materials to establish electronic communication with redox enzymes. Carbon nanomaterials regenerate the biocatalysts either by direct electron transfer or redox mediators which serve as intermediated for the electron transfer. Nano-carbon functionalization is perfectly compatible with other chemical or biological approaches to enhance the enzyme functions in implantable biofuel cells. Efficient immobilization of enzyme using the functionalized nano-carbon materials is the key point that greatly increases the possibilities of success. Current review highlights the progress on implantable biofuel cell, with focus on the nano-carbon functionalization for enzyme immobilization enhancement in glucose/O2 biofuel cells. PMID:26785309

  19. Combinational Effect of Cell Adhesion Biomolecules and Their Immobilized Polymer Property to Enhance Cell-Selective Adhesion

    Directory of Open Access Journals (Sweden)

    Rio Kurimoto

    2016-01-01

    Full Text Available Although surface immobilization of medical devices with bioactive molecules is one of the most widely used strategies to improve biocompatibility, the physicochemical properties of the biomaterials significantly impact the activity of the immobilized molecules. Herein we investigate the combinational effects of cell-selective biomolecules and the hydrophobicity/hydrophilicity of the polymeric substrate on selective adhesion of endothelial cells (ECs, fibroblasts (FBs, and smooth muscle cells (SMCs. To control the polymeric substrate, biomolecules are immobilized on thermoresponsive poly(N-isopropylacrylamide-co-2-carboxyisopropylacrylamide (poly(NIPAAm-co-CIPAAm-grafted glass surfaces. By switching the molecular conformation of the biomolecule-immobilized polymers, the cell-selective adhesion performances are evaluated. In case of RGDS (Arg-Gly-Asp-Ser peptide-immobilized surfaces, all cell types adhere well regardless of the surface hydrophobicity. On the other hand, a tri-Arg-immobilized surface exhibits FB-selectivity when the surface is hydrophilic. Additionally, a tri-Ile-immobilized surface exhibits EC-selective cell adhesion when the surface is hydrophobic. We believe that the proposed concept, which is used to investigate the biomolecule-immobilized surface combination, is important to produce new biomaterials, which are highly demanded for medical implants and tissue engineering.

  20. Hemicellulosic ethanol production by immobilized cells of Scheffersomyces stipitis: Effect of cell concentration and stirring

    OpenAIRE

    Milessi, Thais S S; Antunes, Felipe A. F.; Chandel, Anuj K; Silvio S. da Silva

    2015-01-01

    Bioconversion of hemicellulosic hydrolysate into ethanol plays a pivotal role in the overall success of biorefineries. For the efficient fermentative conversion of hemicellulosic hydrolysates into ethanol, the use of immobilized cells system could provide the enhanced ethanol productivities with significant time savings. Here, we investigated the effect of 2 important factors (e.g., cell concentration and stirring) on ethanol production from sugarcane bagasse hydrolysate using the yeast Schef...

  1. Bioproduction of usnic acid from acetate by kaolinite immobilized cells of Cladonia substellata Vain.

    Directory of Open Access Journals (Sweden)

    Eugenia C. Pereira

    2014-02-01

    Full Text Available Cells of the lichen Cladonia substellata, immobilized in kaolinite and supplied with acetate, produce at room temperature large amounts of usnic acid which can be recovered from the washing solution.

  2. Hydrolysis of fish protein by Bacillus megaterium cells immobilized in radiation induced polymerized wood

    International Nuclear Information System (INIS)

    The immobilization of Bacillus megaterium cells in radiation-induced polymerized wood was studied for hydrolysis of trash fish protein. The optimum conditions and reaction kinetics for hydrolysis of protein by free and immobilized cells were found to be similar. Maximum hydrolysis occurred at 50oC and at pH 7.5 with 15-20% (w/v) of immobilized matrix. The soluble content of the resultant hydrolysate about 2.4% (w/v). (author). 10 refs., 4 figs

  3. Immobilization of cellulose producing cells (sporotrichum cellulophilum) using irradiated rice husk as a substrate

    International Nuclear Information System (INIS)

    An experiment to study the effect of irradiated rice husk as a substrate on cellulase production of free and immobilized cells of S. cellulophium was carried out. Radiation pretreatment of rice husk was done using electron beam accelerator (Dynamitron IEA 3000-25,2), with doses of 0, 0.2, 0.4, 0.6, 0.8, and 1.0 MGy. The substrate used in cellulase production of free and immobilized cells were cellulose powder as a standard, and 1.0 MGy irradiated rice husk. Concentrations of cellulose powder for free and immobilized cells were 1, 2, 3, 5, and 8% (w/v). Irradiated rice husk concentrations for free cells were 3, 6, 9, 15, and 24% (w/v), whereas for immobilized cells were 3, 6, and 9% (w/v). Results showed that glucose concentration in 1.0 MGy irradiated rice husk was the highest of all irradiated and unirradiated rice husks. The GPA (glucose production activity) values used of free immobilized cells of S. cellulophium in medium containing 1.0 MGy irradiated rice husk were about 50% lower than in cellulose powder medium. Cellulase solution resulted by immobilized cells, either in cellulose powder or in irradiated rice husk media, were clear and did not contain mycelium. (authors). 7 refs, 7 figs

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

    OpenAIRE

    Dan Caşcaval; Anca-Irina Galaction; Roxana Rotaru

    2011-01-01

    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 insi...

  5. Integrated continuous winemaking process involving sequential alcoholic and malolactic fermentations with immobilized cells

    OpenAIRE

    Genisheva, Zlatina Asenova; Mota, A; Mussatto, Solange I.; Oliveira, J.M.; Teixeira, J.A.

    2014-01-01

    An integrated winemaking process – including sequential alcoholic and malolactic fermentations operated continuously – was developed. For the continuous alcoholic fermentation, yeast cells (Saccharomyces cerevisiae) were immobilized either on grape stems or on grape skins, while bacterial cells (Oenococcus oeni) used for conducting continuous malolactic fermentation were immobilized on grape skins only. The produced wines were subjected to chemical analysis by HPLC (ethanol, glycerol, sugars ...

  6. Microwave-synthesized magnetic chitosan microparticles for the immobilization of yeast cells.

    Science.gov (United States)

    Safarik, Ivo; Pospiskova, Kristyna; Maderova, Zdenka; Baldikova, Eva; Horska, Katerina; Safarikova, Mirka

    2015-01-01

    An extremely simple procedure has been developed for the immobilization of Saccharomyces cerevisiae cells on magnetic chitosan microparticles. The magnetic carrier was prepared using an inexpensive, simple, rapid, one-pot process, based on the microwave irradiation of chitosan and ferrous sulphate at high pH. Immobilized yeast cells have been used for sucrose hydrolysis, hydrogen peroxide decomposition and the adsorption of selected dyes. PMID:24753015

  7. Hemicellulosic ethanol production by immobilized cells of Scheffersomyces stipitis: effect of cell concentration and stirring.

    Science.gov (United States)

    Milessi, Thais S S; Antunes, Felipe A F; Chandel, Anuj K; da Silva, Silvio S

    2015-01-01

    Bioconversion of hemicellulosic hydrolysate into ethanol plays a pivotal role in the overall success of biorefineries. For the efficient fermentative conversion of hemicellulosic hydrolysates into ethanol, the use of immobilized cells system could provide the enhanced ethanol productivities with significant time savings. Here, we investigated the effect of 2 important factors (e.g., cell concentration and stirring) on ethanol production from sugarcane bagasse hydrolysate using the yeast Scheffersomyces stipitis immobilized in calcium alginate matrix. A 2(2) full factorial design of experiment was performed considering the process variables- immobilized cell concentration (3.0, 6.5 and 10.0 g/L) and stirring (100, 200 and 300 rpm). Statistical analysis showed that stirring has the major influence on ethanol production. Maximum ethanol production (8.90 g/l) with ethanol yield (Yp/s) of 0.33 g/g and ethanol productivity (Qp) of 0.185 g/l/h was obtained under the optimized process conditions (10.0 g/L of cells and 100 rpm). PMID:25488725

  8. Engineering cholesterol-based fibers for antibody immobilization and cell capture

    Science.gov (United States)

    Cohn, Celine

    In 2015, the United States is expected to have nearly 600,000 deaths attributed to cancer. Of these 600,000 deaths, 90% will be a direct result of cancer metastasis, the spread of cancer throughout the body. During cancer metastasis, circulating tumor cells (CTCs) are shed from primary tumors and migrate through bodily fluids, establishing secondary cancer sites. As cancer metastasis is incredibly lethal, there is a growing emphasis on developing "liquid biopsies" that can screen peripheral blood, search for and identify CTCs. One popular method for capturing CTCs is the use of a detection platform with antibodies specifically suited to recognize and capture cancer cells. These antibodies are immobilized onto the platform and can then bind and capture cells of interest. However, current means to immobilize antibodies often leave them with drastically reduced function. The antibodies are left poorly suited for cell capture, resulting in low cell capture efficiencies. This body of work investigates the use of lipid-based fibers to immobilize proteins in a way that retains protein function, ultimately leading to increased cell capture efficiencies. The resulting increased efficiencies are thought to arise from the retained three-dimensional structure of the protein as well as having a complete coating of the material surface with antibodies that are capable of interacting with their antigens. It is possible to electrospin cholesterol-based fibers that are similar in design to the natural cell membrane, providing proteins a more natural setting during immobilization. Such fibers have been produced from cholesterol-based cholesteryl succinyl silane (CSS). These fibers have previously illustrated a keen aptitude for retaining protein function and increasing cell capture. Herein the work focuses on three key concepts. First, a model is developed to understand the immobilization mechanism used by electrospun CSS fibers. The antibody immobilization and cell capturing

  9. OPTIMIZATION OF XYLANASE PRODUCTION FROM FREE AND IMMOBILIZED CELLS OF FUSARIUM SOLANI F7

    Directory of Open Access Journals (Sweden)

    Vijai Kumar Gupta

    2009-08-01

    Full Text Available The aim of the present investigation was to characterize a xylanase-producing Fusarium solani isolate and to optimize cultural conditions for xylanase enzyme production from free and immobilized cells. Screening of Fusarium solani isolate was based on the diameter of the clear zone formation in oat spelt xylan agar plates. Fusarium solani isolate F7 was selected and optimized for xylanase enzyme production using cheaper substrates such as wheat straw, rice straw, rice bran, and wood husk. Maximum enzyme activity was observed in wheat straw (78.32 U ml-1 for free cells and 94.68 U ml-1 for immobilized cells. Optimum pH and temperature for xylanase activity were found to be 5.5 and 30°C at 3% substrate concentration for free cells and 5.0 and 30°C at 3% substrate concentration for immobilized cells. In the purification step, 75% ammonium sulphate saturation was found to be suitable, giving maximum xylanase activity. Production of xylanase was greater from immobilized cells than from free cells. Purified xylanase from free cells yielded a single band with a molecular weight of 89kDa, while it was 92.8kDa for immobilized cells. The use of wheat straw as a major carbon source is particularly valuable, because oat spelt xylan is very expensive. The Fusarium solani F7 isolate proved to be a promising microorganism for xylanase production.

  10. 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

  11. Biodegradation of pesticide profenofos by the free and immobilized cells of Pseudoxanthomonas suwonensis strain HNM.

    Science.gov (United States)

    Talwar, Manjunatha P; Ninnekar, Harichandra Z

    2015-09-01

    Profenofos is an organophosphate pesticide used extensively in agriculture to control pests. A bacterium capable of degrading profenofos was isolated from pesticide-contaminated soil samples and identified as Pseudoxanthomonas suwonensis strain HNM based on its morphological and biochemical characteristics and phylogenetic analysis of 16S rRNA gene sequences. 4-Bromo-2-chlorophenol was identified as a metabolite of profenofos degradation by HPLC and GC-MS analysis. The organism degraded profenofos by hydrolysis to yield 4-bromo-2-chlorophenol which was further utilized as carbon source for growth. The organism utilized various organophosphate pesticides such as temephos, quinalphos, and chloropyrifos as carbon sources. The optimum conditions for degradation of profenofos by P. suwonensis strain HMN were found to be at pH 7 and 30 °C. We have investigated the rate of degradation of profenofos by the free and immobilized cells of P. suwonensis strain HNM in various matrices such as sodium alginate (SA), sodium alginate-polyvinyl alcohol (SA-PVA), and SA-bentonite clay. The rate of degradation of 3 and 6 mM profenofos by the freely suspended cells were compared with that by immobilized cells in batches and semi-continuous with shaken cultures. The SA-bentonite clay-immobilized cells showed higher rate of degradation of 3 and 6 mM profenofos then freely suspended cells and cells immobilized in SA and SA-PVA. The SA-bentonite clay-immobilized cells of P. suwonensis strain HNM could be reused for more than 32 cycles without losing their degradation capacity. Thus, the immobilized cells are more efficient than freely suspended cells for the degradation of organophosphate pesticide contaminated water. PMID:25832924

  12. Immobilization of Escherichia coli cells with penicillin-amidohydrolase activity on solid polymeric carriers.

    Science.gov (United States)

    Zurková, E; Drobník, J; Kálal, J; Svec, F; Tyrácková, V; Vojtísek, V; Zeman, R

    1983-09-01

    Whole cells of Escherichia coli containing the enzyme penicillinamidohydrolase EC 3.5.1.11 were immobilized on the surface of modified macroporous copolymers of glycidylmethacrylate with ethylenedimethacrylate and of copolymers of methacrylaldehyde (MA) with divinylbenzene (DVB) by means of glutaraldehyde. These polymeric carriers were modified before cell binding by using ammonia or polyamines, especially ethylenediamine and hexamethylenediamine (HMDA). The highest specific activity and the largest yield in cell immobilization were achieved with the macroporous copolymer of MA and DVB modified with HMDA. The material thus obtained was used in repeated conversions of benzylpenicillin to 6-aminopenicillanic acid in a stirred batch reactor. PMID:18574818

  13. Ethanol production by Kluyveromyces lactis immobilized cells in copolymer carriers produced by radiation polymerization.

    Science.gov (United States)

    El-Batal, A I; Farahat, L M; El-Rehim, H A

    2000-01-01

    The conditions for batch and continuous production of ethanol, using immobilized growing yeast cells of Kluyveromyces lactis, have been optimized. Yeast cells have been immobilized in hydrogel copolymer carriers composed of polyvinyl alcohol (PVA) with various hydrophilic monomers, using radiation copolymerization technique. Yeast cells were immobilized through adhesion and multiplication of yeast cells themselves. The ethanol production of immobilized growing yeast cells with these hydrogel carriers was related to the monomer composition of the copolymers and the optimum monomer composition was hydroxyethyl methacrylate (HEMA). In this case by using batch fermentation, the superior ethanol production was 32.9 g L(-1) which was about 4 times higher than that of cells in free system. The relation between the activity of immobilized yeast cells and the water content of the copolymer carriers was also discussed. Immobilized growing yeast cells in PVA: HEMA (7%: 10%, w/w) hydrogel copolymer carrier, were used in a packed-bed column reactor for the continuous production of ethanol from lactose at different levels of concentrations (50, 100 and 150) g L(-1). For all lactose feed concentrations, an increase in dilution rates from 0.1 h(-1) to 0.3 h(-1) lowered ethanol concentration in fermented broth, but the volumetric ethanol productivity and volumetric lactose uptake rate were improved. The fermentation efficiency was lowered with the increase in dilution rate and also at higher lactose concentration in feed medium and a maximum of 70.2% was obtained at the lowest lactose concentration 50 g L(-1). PMID:11093678

  14. On chip single-cell separation and immobilization using optical tweezers and thermosensitive hydrogel.

    Science.gov (United States)

    Arai, Fumihito; Ng, Chinaik; Maruyama, Hisataka; Ichikawa, Akihiko; El-Shimy, Haitham; Fukuda, Toshio

    2005-12-01

    A novel approach appropriate for rapid separation and immobilization of a single cell by concomitantly utilizing laser manipulation and locally thermosensitive hydrogelation is proposed in this paper. We employed a single laser beam as optical tweezers for separating a target cell and locating it adjacent to a fabricated, transparent micro heater. Simultaneously, the target cell is immobilized or partially entrapped by heating the thermosensitive hydrogel with the micro heater. The state of the thermosensitive hydrogel can be switched from sol to gel and gel to sol by controlling the temperature through heating and cooling by the micro heater. After other unwanted cells are removed by the high-speed cleaning flow in the microchannel, the entrapped cell is successfully isolated. It is possible to collect the immobilized target cell for analysis or culture by switching off the micro heater and releasing the cell from the entrapment. We demonstrated that the proposed approach is feasible for rapid manipulation, immobilization, cleaning, isolation and extraction of a single cell. The experimental results are shown here. PMID:16286972

  15. Nitrilase-catalysed conversion of acrylonitrile by free and immobilized cells of Streptomyces sp.

    Indian Academy of Sciences (India)

    V K Nigam; A K Khandelwal; R K Gothwal; M K Mohan; B Choudhury; A S Vidyarthi; P Ghosh

    2009-03-01

    The biotransformation of acrylonitrile was investigated using thermophilic nitrilase produced from a new isolate Streptomyces sp. MTCC 7546 in both the free and immobilized state. Under optimal conditions, the enzyme converts nitriles to acids without the formation of amides. The whole cells of the isolate were immobilized in agar-agar and the beads so formed were evaluated for 25 cycles at 50°C. The enzyme showed a little loss of activity during reuse. Seventy-one per cent of 0.5 M acrylonitrile was converted to acid at 6 h of incubation at a very low density of immobilized cells, while 100% conversion was observed at 3 h by free cells.

  16. [Comparison of fibroblastic cell compatibility of type I collagen-immobilized titanium between electrodeposition and immersion].

    Science.gov (United States)

    Kyuragi, Takeru

    2014-03-01

    Titanium is widely used for medical implants. While many techniques for surface modification have been studied for optimizing its biocompatibility with hard tissues, little work has been undertaken to explore ways of maximizing its biocompatibility with soft tissues. We investigated cell attachment to titanium surfaces modified with bovine Type I collagen immobilized by either electrodeposition or a conventional immersion technique. The apparent thickness and durability of the immobilized collagen layer were evaluated prior to incubation of the collagen-immobilized titanium surfaces with NIH/3T3 mouse embryonic fibroblasts. The initial cell attachment and expression of actin and vinculin were evaluated. We determined that the immobilized collagen layer was much thicker and more durable when placed using the electrodeposition technique than the immersion technique. Both protocols produced materials that promoted better cell attachment, growth and structural protein expression than titanium alone. However, electrodeposition was ultimately superior to immersion because it is quicker to perform and produces a more durable collagen coating. We conclude that electrodeposition is an effective technique for immobilizing type I collagen on titanium surfaces, thus improving their cytocompatibility with fibroblasts. PMID:24812763

  17. 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.

  18. Immobilization method of yeast cells for intermittent contact mode imaging using the atomic force microscope

    International Nuclear Information System (INIS)

    The atomic force microscope (AFM) is widely used for studying the surface morphology and growth of live cells. There are relatively fewer reports on the AFM imaging of yeast cells (Kasas and Ikai, 1995), (Gad and Ikai, 1995). Yeasts have thick and mechanically strong cell walls and are therefore difficult to attach to a solid substrate. In this report, a new immobilization technique for the height mode imaging of living yeast cells in solid media using AFM is presented. The proposed technique allows the cell surface to be almost completely exposed to the environment and studied using AFM. Apart from the new immobilization protocol, for the first time, height mode imaging of live yeast cell surface in intermittent contact mode is presented in this report. Stable and reproducible imaging over a 10-h time span is observed. A significant improvement in operational stability will facilitate the investigation of growth patterns and surface patterns of yeast cells.

  19. Immobilization of anode-attached microbes in a microbial fuel cell.

    KAUST Repository

    Wagner, Rachel C

    2012-01-03

    Current-generating (exoelectrogenic) bacteria in bioelectrochemical systems (BESs) may not be culturable using standard in vitro agar-plating techniques, making isolation of new microbes a challenge. More in vivo like conditions are needed where bacteria can be grown and directly isolated on an electrode. While colonies can be developed from single cells on an electrode, the cells must be immobilized after being placed on the surface. Here we present a proof-of-concept immobilization approach that allows exoelectrogenic activity of cells on an electrode based on applying a layer of latex to hold bacteria on surfaces. The effectiveness of this procedure to immobilize particles was first demonstrated using fluorescent microspheres as bacterial analogs. The latex coating was then shown to not substantially affect the exoelectrogenic activity of well-developed anode biofilms in two different systems. A single layer of airbrushed coating did not reduce the voltage produced by a biofilm in a microbial fuel cell (MFC), and more easily applied dip-and-blot coating reduced voltage by only 11% in a microbial electrolysis cell (MEC). This latex immobilization procedure will enable future testing of single cells for exoelectrogenic activity on electrodes in BESs.

  20. Immobilization of yeast cells with ionic hydrogel produced by radiation polymerization

    International Nuclear Information System (INIS)

    The mixture of an ionic monomer of 2-acrylamido 2-methylpropane-sulfonic acid and a series of polyethylene glycol dimethacrylate monomer were polymerized at-78 deg C with 60Co γ-rays and were used for immobilization of yeast cells. The immobilized yeast cells with these carriers had higher ethanol productivity than that without any carriers. The yield of ethanol with poly TBAS-14G carrier was the highest, and increased by 3.5 times compared with the free yeast cells. It was found that the ethanol yield increased with the increase of the glycol number in polyethylene glycol dimethacrylate. The state of the immobilized cells was observed with microscope and it was found that the difference in the ethanol productivity was mainly due to the difference in the internal structure and the properties of polymer carrier. It was considered that the polymer carrier had a proper hydrophilicity, swelling ability, cation in the surface and porousity in the internal structure for immobilizing yeast cells

  1. Ethanol production and the effect of porous polymer carriers on immobilized growing yeast cells by radiation-induced polymerization

    International Nuclear Information System (INIS)

    As a means of producing ethanol as fuel from waste cellulose, yeast cells were immobilized by radiation-induced polymerization. Precultured yeast cells were incubated aerobically at 300C for 24 h with porous polymer carriers prepared by radiation-induced polymerization at a low temperature. Yeast cells adsorbed on the surface of these porous carriers were immersed in monomer solution and were immobilized by radiation-induced polymerization of this monomer. The maximum ethanol productivity in an immobilized yeast cell system was found to be about 10 times greater than that in a free yeast cell system. (author)

  2. Hexavalent chromium reduction by immobilized cells of Bacillus sphaericus AND 303

    Directory of Open Access Journals (Sweden)

    Arundhati Pal

    2013-06-01

    Full Text Available Bacillus sphaericus AND 303, a Cr(VI-resistant and reducing bacterium reported from serpentine outcrops of Andaman was evaluated for Cr(VI reduction using immobilized cells under batch culture. Screening of inert matrices for entrapment of whole cells indicated that polyvinyl alchohol-alginate was the most effective one reducing 87.5% of 20 µM Cr(VI in 24 h. The rate of chromate reduction was dependent on initial Cr(VI and biomass concentrations. The PVA cell beads were recycled three times without cell leakage and disintegration. The reduction efficiency was improved in the presence of glucose and glycerol as electron donors leading to complete reduction. However, the presence of additional metal ions was inhibitory to Cr(VI reduction. It could be emphasized that PVA-alginate immobilized cells of B. sphaericus AND 303 could be used as a continuous bioprocess in treating Cr(VI contaminated effluents.

  3. Use of Saccharomyces cerevisiae cells immobilized on orange peel as biocatalyst for alcoholic fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Plessas, S.; Bekatorou, A; Koutinas, A.A.; Soupioni, M. [University of Patras (Greece). Department of Chemistry, Food Biotechnology Group; Banat, I.M.; Marchant, R. [University of Ulster, Coleraine, N. Ireland (United Kingdom). School of Biomedical Sciences

    2007-03-15

    A biocatalyst was prepared by immobilizing a commercial Saccharomyces cerevisiae strain (baker's yeast) on orange peel pieces for use in alcoholic fermentation and for fermented food applications. Cell immobilization was shown by electron microscopy and by the efficiency of the immobilized biocatalyst for alcoholic fermentation of various carbohydrate substrates (glucose, molasses, raisin extracts) and at various temperatures (30-15 {sup o}C). Fermentation times in all cases were low (5-15 h) and ethanol productivities were high (av. 150.6 g/ld) showing good operational stability of the biocatalyst and suitability for commercial applications. Reasonable amounts of volatile by-products were produced at all temperatures studied, revealing potential application of the proposed biocatalyst in fermented food applications, to improve productivities and quality. (author)

  4. Removal of Cadmium and Zinc from Soil using Immobilized Cell of Biosurfactant Producing Bacteria

    Directory of Open Access Journals (Sweden)

    Charoon Sarin

    2010-07-01

    Full Text Available Immobilized biosurfactant producing bacteria (Bacillus subtilis TP8 and Pseudomonas fluorescens G7 were assessed for survival in heavy metal contaminated soil and for their ability to remove cadmium and zinc from contaminated soil. P. fluorescens G7 was considered to be a good candidate for bioremediation of heavy metals because of its high minimum inhibitory concentrations (MIC for each heavy metal and because of the obviously increased numbers of cell surviving after incubation in the heavy metal contaminated soil up to 4 weeks. The results of soil remediation showed that approximately 19% of Zn and 16.7% of Cd could be removed by this immobilized biosurfactant producing bacteria after incubation for 2 weeks. The results confirm the potential applicability of the immobilized biosurfactant producing bacteria for heavy metal bioremediation.

  5. Optimization of surface-immobilized extracellular matrices for the proliferation of neural progenitor cells derived from induced pluripotent stem cells.

    Science.gov (United States)

    Komura, Takashi; Kato, Koichi; Konagaya, Shuhei; Nakaji-Hirabayashi, Tadashi; Iwata, Hiroo

    2015-11-01

    Neural progenitor cells derived from induced pluripotent stem cells have been considered as a potential source for cell-transplantation therapy of central nervous disorders. However, efficient methods to expand neural progenitor cells are further required for their clinical applications. In this study, a protein array was fabricated with nine extracellular matrices and used to screen substrates suitable for the expansion of neural progenitor cells derived from mouse induced pluripotent stem cells. The results showed that neural progenitor cells efficiently proliferated on substrates with immobilized laminin-1, laminin-5, or Matrigel. Based on this result, further attempts were made to develop clinically compliant substrates with immobilized polypeptides that mimic laminin-1, one of the most effective extracellular matrices as identified in the array-based screening. We used here recombinant DNA technology to prepare polypeptide containing the globular domain 3 of laminin-1 and immobilized it onto glass-based substrates. Our results showed that neural progenitor cells selectively proliferated on substrate with the immobilized polypeptide while maintaining their differentiated state. PMID:25943789

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

    International Nuclear Information System (INIS)

    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 Na2SO4. Immobilized enzymes were analysed concerning to thermal and operational stability. Immobilization in presence of Na2SO4 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

  7. 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.

  8. Immobilization of Escherichia coli Cells Containing Aspartase Activity with Polyurethane and Its Application for l-Aspartic Acid Production

    OpenAIRE

    Fusee, Murray C.; Swann, Wayne E.; Calton, Gary J.

    1981-01-01

    Whole cells of Escherichia coli containing aspartase activity were immobilized by mixing a cell suspension with a liquid isocyanate-capped polyurethane prepolymer (Hypol). The immobilized cell preparation was used to convert ammonium fumarate to l-aspartic acid. Properties of the immobilized E. coli cells containing aspartase were investigated with a batch reactor. A 1.67-fold increase in the l-aspartic acid production rate was observed at 37°C as compared to 25°C operating temperature. The p...

  9. Analysis of Distributed Growth of Saccharomyces cerevisiae Cells Immobilized in Polyacrylamide Gel

    OpenAIRE

    Burrill, Hugh N.; Bell, Laurel E.; Greenfield, Paul F.; Do, Duong D.

    1983-01-01

    A technique is described for the quantitative determination of the distributed growth of Saccharomyces cerevisiae immobilized in polyacrylamide gel. Gel specimens were embedded in paraffin or gelatin and paraffin before sectioning and staining. Photomicrographs of specimen sections were enlarged, and cell microcolony volumes were determined as a function of position in the gel by grid transparency analysis. Overall cell densities within the gel were calculated for a quantitative comparison wi...

  10. Flexible Programming of Cell-Free Protein Synthesis Using Magnetic Bead-Immobilized Plasmids

    OpenAIRE

    Lee, Ka-Young; Lee, Kyung-Ho; Park, Ji-Woong; Kim, Dong-Myung

    2012-01-01

    The use of magnetic bead-immobilized DNA as movable template for cell-free protein synthesis has been investigated. Magnetic microbeads containing chemically conjugated plasmids were used to direct cell-free protein synthesis, so that protein generation could be readily programmed, reset and reprogrammed. Protein synthesis by using this approach could be ON/OFF-controlled through repeated addition and removal of the microbead-conjugated DNA and employed in sequential expression of different g...

  11. Bioleaching of Primary Nickel Ore Using Acidithiobacillus ferrooxidans LR Cells Immobilized in Glass Beads

    Directory of Open Access Journals (Sweden)

    Ellen Cristine Giese

    2015-06-01

    Full Text Available Sulphide minerals are one of the most important sources of value metals. For several years, a large number of hydrometallurgical and biotechnological processes have been developed to leach low-grade sulphide ores and the conditions are well established. However, the management of microorganisms in the bioleaching process is not easy to handle. In this paper, the use of immobilized cells of Acidithiobacillus ferrooxidans LR in glass beads in bioleaching of primary nickel ore was evaluated. The column experiments inoculated with immobilized cells of A. ferrooxidans LR showed the same efficiency than the conventional method using free cells and is promising for application on a larger scale as it ensuring integrity and activity of biomining microorganisms and reduce process costs. DOI: http://dx.doi.org/10.17807/orbital.v7i2.698 

  12. Enhanced dibenzothiophene biodesulfurization by immobilized cells of Brevibacterium lutescens in n-octane-water biphasic system.

    Science.gov (United States)

    Dai, Yong; Shao, Rong; Qi, Gang; Ding, Bin-Bin

    2014-11-01

    In this study, it was the first report that the Brevibacterium lutescens CCZU12-1 was employed as a sulfur removing bacteria. Using dibenzothiophene (DBT) as the sole sulfur source, B. lutescens could selectively degrade DBT into 2-hydroxybiphenyl (2-HBP) via the "4S" pathway. In the basal salt medium (BSM) supplemented with 0.25 mM DBT and 0.5 g/L Tween-80, high desulfurization rate (100 %) was obtained by growth cells after 60 h. Furthermore, the n-octane-water (10:90, v/v) biphasic system was built for the biodesulfurization by resting cells. Moreover, a combination of magnetic nano Fe3O4 particles with calcium alginate immobilization was used for enhancing biodesulfurization. In this n-octane-water biphasic system, immobilized B. lutescens cells could be reused for not less than four times. Therefore, B. lutescens CCZU12-1 shows high potential in the biodesulfurization. PMID:25173674

  13. The enhancement of chondrogenesis of ATDC5 cells in RGD-immobilized microcavitary alginate hydrogels.

    Science.gov (United States)

    Yao, Yongchang; Zeng, Lei; Huang, Yuyang

    2016-07-01

    In our previous work, we have developed an effective microcavitary alginate hydrogel for proliferation of chondrocytes and maintenance of chondrocytic phenotype. In present work, we investigated whether microcavitary alginate hydrogel could promote the chondrogenesis of progenitor cells. Moreover, we attempted to further optimize this system by incorporating synthetic Arg-Gly-Asp peptide. ATDC5 cells were seeded into microcavitary alginate hydrogel with or without Arg-Gly-Asp immobilization. Cell Counting Kit-8 and live/dead staining were conducted to analyze cell proliferation. Real-time polymerase chain reaction (RT-PCR), hematoxylin and eosin, and Toluidine blue O staining as well as Western blot assay was performed to evaluate the cartilaginous markers at transcriptional level and at protein level, respectively. The obtained data demonstrated that Arg-Gly-Asp-immobilized microcavitary alginate hydrogel was preferable to promote the cell proliferation. Also, Arg-Gly-Asp-immobilized microcavitary alginate hydrogel improved the expression of chondrocytic genes including Collagen II and Aggrecan when compared with microcavitary alginate hydrogel. The results suggested that microcavitary alginate hydrogel could promote the chondrogenesis. And Arg-Gly-Asp would be promising to ameliorate this culture system for cartilage tissue engineering. PMID:27000189

  14. Cell culture plastics with immobilized interleukin-4 for monocyte differentiation

    DEFF Research Database (Denmark)

    Hansen, Morten; Hjortø, Gertrud Malene; Met, Özcan;

    2011-01-01

    Standard cell culture plastic was surface modified by passive adsorption or covalent attachment of interleukin (IL)-4 and investigated for its ability to induce differentiation of human monocytes into mature dendritic cells, a process dose-dependently regulated by IL-4. Covalent attachment of IL-4...

  15. Cell culture plastics with immobilized interleukin-4 for monocyte differentiation

    DEFF Research Database (Denmark)

    Hansen, Morten; Hjortø, Gertrud Malene; Met, Ozcan;

    2011-01-01

    Standard cell culture plastic was surface modified by passive adsorption or covalent attachment of interleukin (IL)-4 and investigated for its ability to induce differentiation of human monocytes into mature dendritic cells, a process dose-dependently regulated by IL-4. Covalent attachment of IL-...

  16. New method for selection of hydrogen peroxide adapted bifidobacteria cells using continuous culture and immobilized cell technology

    Directory of Open Access Journals (Sweden)

    Meile Leo

    2010-07-01

    Full Text Available Abstract Background Oxidative stress can severely compromise viability of bifidobacteria. Exposure of Bifidobacterium cells to oxygen causes accumulation of reactive oxygen species, mainly hydrogen peroxide, leading to cell death. In this study, we tested the suitability of continuous culture under increasing selective pressure combined with immobilized cell technology for the selection of hydrogen peroxide adapted Bifidobacterium cells. Cells of B. longum NCC2705 were immobilized in gellan-xanthan gum gel beads and used to continuously ferment MRS medium containing increasing concentration of H2O2 from 0 to 130 ppm. Results At the beginning of the culture, high cell density of 1013 CFU per litre of reactor was tested. The continuous culture gradually adapted to increasing H2O2 concentrations. However, after increasing the H2O2 concentration to 130 ppm the OD of the culture decreased to 0. Full wash out was prevented by the immobilization of the cells in gel matrix. Hence after stopping the stress, it was possible to re-grow the cells that survived the highest lethal dose of H2O2 and to select two adapted colonies (HPR1 and HPR2 after plating of the culture effluent. In contrast to HPR1, HPR2 showed stable characteristics over at least 70 generations and exhibited also higher tolerance to O2 than non adapted wild type cells. Preliminary characterization of HPR2 was carried out by global genome expression profile analysis. Two genes coding for a protein with unknown function and possessing trans-membrane domains and an ABC-type transporter protein were overexpressed in HPR2 cells compared to wild type cells. Conclusions Our study showed that continuous culture with cell immobilization is a valid approach for selecting cells adapted to hydrogen peroxide. Elucidation of H2O2 adaptation mechanisms in HPR2 could be helpful to develop oxygen resistant bifidobacteria.

  17. Internalization: acute apoptosis of breast cancer cells using herceptin-immobilized gold nanoparticles

    Directory of Open Access Journals (Sweden)

    Rathinaraj P

    2015-02-01

    Full Text Available Pierson Rathinaraj,1 Ahmed M Al-Jumaily,1 Do Sung Huh21Institute of Biomedical Technologies, Auckland University of Technology, Auckland, New Zealand; 2Department of Nano science and Engineering, Inje University, Gimhea, South KoreaAbstract: Herceptin, the monoclonal antibody, was successfully immobilized on gold nanoparticles (GNPs to improve their precise interactions with breast cancer cells (SK-BR3. The mean size of the GNPs (29 nm, as determined by dynamic light scattering, enlarged to 82 nm after herceptin immobilization. The in vitro cell culture experiment indicated that human skin cells (FB proliferated well in the presence of herceptin-conjugated GNP (GNP–Her, while most of the breast cancer cells (SK-BR3 had died. To elucidate the mechanism of cell death, the interaction of breast cancer cells with GNP–Her was tracked by confocal laser scanning microscopy. Consequently, GNP–Her was found to be bound precisely to the membrane of the breast cancer cell, which became almost saturated after 6 hours incubation. This shows that the progression signal of SK-BR3 cells is retarded completely by the precise binding of antibody to the human epidermal growth factor receptor 2 receptor of the breast cancer cell membrane, causing cell death.Keywords: herceptin, gold nanoparticles, SK-BR3 cells, intracellular uptake

  18. Optimizing Immobilized Enzyme Performance in Cell-Free Environments to Produce Liquid Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Belfort, Georges [Rensselaer Polytechnic Inst., Troy, NY (United States). Dept. of Chemical and Biological Engineering; Grimaldi, Joseph J. [Rensselaer Polytechnic Inst., Troy, NY (United States). Dept. of Chemical and Biological Engineering

    2015-01-27

    Limitations on biofuel production using cell culture (Escherichia coli, Clostridium, Saccharomyces cerevisiae, brown microalgae, blue-green algae and others) include low product (alcohol) concentrations (≤0.2 vol%) due to feedback inhibition, instability of cells, and lack of economical product recovery processes. To overcome these challenges, an alternate simplified biofuel production scheme was tested based on a cell-free immobilized enzyme system. Using this cell free system, we were able to obtain about 2.6 times higher concentrations of iso-butanol using our non-optimized system as compared with live cell systems. This process involved two steps: (i) converts acid to aldehyde using keto-acid decarboxylase (KdcA), and (ii) produces alcohol from aldehyde using alcohol dehydrogenase (ADH) with a cofactor (NADH) conversion from inexpensive formate using a third enzyme, formate dehydrogenase (FDH). To increase stability and conversion efficiency with easy separations, the first two enzymes were immobilized onto methacrylate resin. Fusion proteins of labile KdcA (fKdcA) were expressed to stabilize the covalently immobilized KdcA. Covalently immobilized ADH exhibited long-term stability and efficient conversion of aldehyde to alcohol over multiple batch cycles without fusions. High conversion rates and low protein leaching were achieved by covalent immobilization of enzymes on methacrylate resin. The complete reaction scheme was demonstrated by immobilizing both ADH and fKdcA and using FDH free in solution. The new system without in situ removal of isobutanol achieved a 55% conversion of ketoisovaleric acid to isobutanol at a concentration of 0.5 % (v/v). Further increases in titer will require continuous removal of the isobutanol using our novel brush membrane system that exhibits a 1.5 fold increase in the separation factor of isobutanol from water versus that obtained for commercial silicone rubber membranes. These bio-inspired brush membranes are based on the

  19. A novel cell weighing method based on the minimum immobilization pressure for biological applications

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Qili [Robotics and Mechatronics Research Laboratory, Department of Mechanical and Aerospace Engineering, Monash University, Clayton 3800 (Australia); Institute of Robotics and Automatic Information System, Nankai University, Tianjin 300071 (China); Shirinzadeh, Bijan [Robotics and Mechatronics Research Laboratory, Department of Mechanical and Aerospace Engineering, Monash University, Clayton 3800 (Australia); Cui, Maosheng [Biotechnology Lab of Animal Reproduction, Tianjin Animal Sciences, Tianjin 300112 (China); Sun, Mingzhu; Liu, Yaowei; Zhao, Xin, E-mail: zhaoxin@nankai.edu.cn [Institute of Robotics and Automatic Information System, Nankai University, Tianjin 300071 (China)

    2015-07-28

    A novel weighing method for cells with spherical and other regular shapes is proposed in this paper. In this method, the relationship between the cell mass and the minimum aspiration pressure to immobilize the cell (referred to as minimum immobilization pressure) is derived for the first time according to static theory. Based on this relationship, a robotic cell weighing process is established using a traditional micro-injection system. Experimental results on porcine oocytes demonstrate that the proposed method is able to weigh cells at an average speed of 16.3 s/cell and with a success rate of more than 90%. The derived cell mass and density are in accordance with those reported in other published results. The experimental results also demonstrated that this method is able to detect less than 1% variation of the porcine oocyte mass quantitatively. It can be conducted by a pair of traditional micropipettes and a commercial pneumatic micro-injection system, and is expected to perform robotic operation on batch cells. At present, the minimum resolution of the proposed method for measuring the cell mass can be 1.25 × 10{sup −15 }kg. Above advantages make it very appropriate for quantifying the amount of the materials injected into or moved out of the cells in the biological applications, such as nuclear enucleations and embryo microinjections.

  20. A novel cell weighing method based on the minimum immobilization pressure for biological applications

    International Nuclear Information System (INIS)

    A novel weighing method for cells with spherical and other regular shapes is proposed in this paper. In this method, the relationship between the cell mass and the minimum aspiration pressure to immobilize the cell (referred to as minimum immobilization pressure) is derived for the first time according to static theory. Based on this relationship, a robotic cell weighing process is established using a traditional micro-injection system. Experimental results on porcine oocytes demonstrate that the proposed method is able to weigh cells at an average speed of 16.3 s/cell and with a success rate of more than 90%. The derived cell mass and density are in accordance with those reported in other published results. The experimental results also demonstrated that this method is able to detect less than 1% variation of the porcine oocyte mass quantitatively. It can be conducted by a pair of traditional micropipettes and a commercial pneumatic micro-injection system, and is expected to perform robotic operation on batch cells. At present, the minimum resolution of the proposed method for measuring the cell mass can be 1.25 × 10−15 kg. Above advantages make it very appropriate for quantifying the amount of the materials injected into or moved out of the cells in the biological applications, such as nuclear enucleations and embryo microinjections

  1. Continuous Ethanol Production Using Immobilized-Cell/Enzyme Biocatalysts in Fluidized-Bed Bioreactor (FBR)

    Energy Technology Data Exchange (ETDEWEB)

    Nghiem, NP

    2003-11-16

    The immobilized-cell fluidized-bed bioreactor (FBR) was developed at Oak Ridge National Laboratory (ORNL). Previous studies at ORNL using immobilized Zymomonas mobilis in FBR at both laboratory and demonstration scale (4-in-ID by 20-ft-tall) have shown that the system was more than 50 times as productive as industrial benchmarks (batch and fed-batch free cell fermentations for ethanol production from glucose). Economic analysis showed that a continuous process employing the FBR technology to produce ethanol from corn-derived glucose would offer savings of three to six cents per gallon of ethanol compared to a typical batch process. The application of the FBR technology for ethanol production was extended to investigate more complex feedstocks, which included starch and lignocellulosic-derived mixed sugars. Economic analysis and mathematical modeling of the reactor were included in the investigation. This report summarizes the results of these extensive studies.

  2. Bioleaching of Primary Nickel Ore Using Acidithiobacillus ferrooxidans LR Cells Immobilized in Glass Beads

    OpenAIRE

    Ellen Cristine Giese; Patrícia Morgado Vaz

    2015-01-01

    Sulphide minerals are one of the most important sources of value metals. For several years, a large number of hydrometallurgical and biotechnological processes have been developed to leach low-grade sulphide ores and the conditions are well established. However, the management of microorganisms in the bioleaching process is not easy to handle. In this paper, the use of immobilized cells of Acidithiobacillus ferrooxidans LR in glass beads in bioleaching of primary nickel ore was evaluated. The...

  3. Polyglycerol dendrimers immobilized on radiation grafted poly-HEMA hydrogels: Surface chemistry characterization and cell adhesion

    International Nuclear Information System (INIS)

    Radiation induced grafting of poly(2-hydroxyethylmethacrylate) (PHEMA) on low density polyethylene (LDPE) films and subsequent immobilization of poly(glycerol) dendrimer (PGLD) has been performed with the aim to improve cell adhesion and proliferation on the surface of the polymer, in order to enhance their properties for bone tissue engineering scaffolding applications. Radiation grafting of PHEMA onto LDPE was promoted by γ-ray radiation. The covalent immobilization of PGLD on LDPE-g-PHEMA surface was performed by using a dicyclohexyl carbodiimide (DCC)/N,N-dimethylaminopyridine (DMAP) method. The occurrence of grafting polymerization of PHEMA and further immobilization of PGLD was quantitatively confirmed by photoelectron spectroscopy (XPS) and fluorescence, respectively. The LDPE-g-PHEMA surface topography after PGLD coupling was studied by atomic force microscopy (AFM). The hydrophilicity of the LDPE-g-PHEMA film was remarkably improved compared to that of the ungrafted LDPE. The core level XPS ESCA spectrum of PHEMA-grafted LDPE showed two strong peaks at 286.6 eV (from hydroxyl groups and ester groups) and 289.1 eV (from ester groups) due to PHEMA brushes grafted onto LDPE surfaces. The results from the cell adhesion studies show that MCT3-E1 cells tended to spread more slowly on the LDPE-g-PHEMA than on the LDPE-g-PHEMA-i-PGLD. - Highlights: • Radiation-grafted PHEMA hydrogels have been obtained by simultaneous gamma-irradiation of LDPE and HEMA monomer. • PGLD dendrimer was immobilized onto PHEMA for application in tissue engineering. • The microstructural characterization of LDPE-g-PHEMA-i-PGLD by RMN, XPS, AFM and MALDI-TOF are made. • Measurements of water uptake and contact angle of LDPE-g-PHEMA are compared to those of LDPE-g-PHEMA-i-PGLD. • The MC3T-E1 osteoblast cell adhesion and growth on LDPE-g-PHEMA-i-PGLD were studied

  4. OPTIMIZATION OF XYLANASE PRODUCTION FROM FREE AND IMMOBILIZED CELLS OF FUSARIUM SOLANI F7

    OpenAIRE

    Vijai Kumar Gupta; Rajeeva Gaur; Santosh Kumar Yadava; Nandan Singh Darmwal

    2009-01-01

    The aim of the present investigation was to characterize a xylanase-producing Fusarium solani isolate and to optimize cultural conditions for xylanase enzyme production from free and immobilized cells. Screening of Fusarium solani isolate was based on the diameter of the clear zone formation in oat spelt xylan agar plates. Fusarium solani isolate F7 was selected and optimized for xylanase enzyme production using cheaper substrates such as wheat straw, rice straw, rice bran, and wood husk. Max...

  5. Biodegradation of cypermethrin by immobilized cells of Micrococcus sp. strain CPN 1

    OpenAIRE

    Tallur, Preeti N.; Mulla, Sikandar I.; Megadi, Veena B.; Talwar, Manjunatha P.; Ninnekar, Harichandra Z.

    2015-01-01

    Pyrethroid pesticide cypermethrin is a environmental pollutant because of its widespread use, toxicity and persistence. Biodegradation of such chemicals by microorganisms may provide an cost-effective method for their detoxification. We have investigated the degradation of cypermethrin by immobilized cells of Micrococcus sp. strain CPN 1 in various matrices such as, polyurethane foam (PUF), polyacrylamide, sodium alginate and agar. The optimum temperature and pH for the degradation of cyperme...

  6. Hexavalent chromium reduction by immobilized cells of Bacillus sphaericus AND 303

    OpenAIRE

    Arundhati Pal; Sudeshna Datta; Amal K. Paul

    2013-01-01

    Bacillus sphaericus AND 303, a Cr(VI)-resistant and reducing bacterium reported from serpentine outcrops of Andaman was evaluated for Cr(VI) reduction using immobilized cells under batch culture. Screening of inert matrices for entrapment of whole cells indicated that polyvinyl alchohol-alginate was the most effective one reducing 87.5% of 20 µM Cr(VI) in 24 h. The rate of chromate reduction was dependent on initial Cr(VI) and biomass concentrations. The PVA cell beads were recycled three tim...

  7. Efficacy of whey protein gel networks as potential viability-enhancing scaffolds for cell immobilization of Lactobacillus rhamnosus GG.

    Science.gov (United States)

    Doherty, S B; Gee, V L; Ross, R P; Stanton, C; Fitzgerald, G F; Brodkorb, A

    2010-03-01

    This study investigated cell immobilization of Lactobacillus rhamnosus GG in three separate protein products: native, denatured and hydrolysed whey protein isolate (WPI). Treatments were assessed for their ability to enhance probiotic survival during storage, heat stress and ex vivo gastric incubation. Spatial distribution of probiotic cells within immobilized treatments was evaluated by atomic force and confocal scanning laser microscopy, while cell viability was enumerated by plate count and flow cytometry (FACS). Microscopic analysis of denatured treatments revealed an oasis of immobilized cells, phase-separated from the surrounding protein matrix; an environmental characteristic analogous to hydrolysed networks. Cell immobilization in hydrolysed and denatured WPI enhanced survival by 6.1+/-0.1 and 5.8+/-0.1 log10 cycles, respectively, following 14 day storage at 37 degrees C and both treatments generated thermal protection at 57 degrees C (7.3+/-0.1 and 6.5+/-0.1 log(10) cfu/ml). Furthermore, denatured WPI enhanced probiotic protection (8.9+/-0.2 log(10) cfu/ml) following 3h gastric incubation at 37 degrees C. In conclusion, hydrolysed or denatured WPI were the most suitable matrices for cell immobilization, while native protein provided the weakest safeguard against thermal and acid stress, thus making it possible to envision whey protein gel networks as protective substrates for cell immobilization applications. PMID:20045713

  8. Application in the Ethanol Fermentation of Immobilized Yeast Cells in Matrix of Alginate/Magnetic Nanoparticles, on Chitosan-Magnetite Microparticles and Cellulose-coated Magnetic Nanoparticles

    CERN Document Server

    Ivanova, Viara; Hristov, Jordan

    2011-01-01

    Saccharomyces cerevisiae cells were entrapped in matrix of alginate and magnetic nanoparticles and covalently immobilized on magnetite-containing chitosan and cellulose-coated magnetic nanoparticles. Cellulose-coated magnetic nanoparticles with covalently immobilized thermostable {\\alpha}-amylase and chitosan particles with immobilized glucoamylase were also prepared. The immobilized cells and enzymes were applied in column reactors - 1/for simultaneous corn starch saccharification with the immobilized glucoamylase and production of ethanol with the entrapped or covalently immobilized yeast cells, 2/ for separate ethanol fermentation of the starch hydrolysates with the fixed yeasts. Hydrolysis of corn starch with the immobilized {\\alpha}-amylase and glucoamylase, and separate hydrolysis with the immobilized {\\alpha}-amylase were also examined. In the first reactor the ethanol yield reached approx. 91% of the theoretical; the yield was approx. 86% in the second. The ethanol fermentation was affected by the typ...

  9. Bioethanol Production from Uncooked Raw Starch by Immobilized Surface-engineered Yeast Cells

    Science.gov (United States)

    Chen, Jyh-Ping; Wu, Kuo-Wei; Fukuda, Hideki

    Surface-engineered yeast Saccharomyces cerevisiae codisplaying Rhizopus oryzae glucoamylase and Streptococcus bovis α-amylase on the cell surface was used for direct production of ethanol from uncooked raw starch. By using 50 g/L cells during batch fermentation, ethanol concentration could reach 53 g/L in 7 days. During repeated batch fermentation, the production of ethanol could be maintained for seven consecutive cycles. For cells immobilized in loofa sponge, the concentration of ethanol could reach 42 g/L in 3 days in a circulating packed-bed bioreactor. However, the production of ethanol stopped thereafter because of limited contact between cells and starch. The bioreactor could be operated for repeated batch production of ethanol, but ethanol concentration dropped to 55% of its initial value after five cycles because of a decrease in cell mass and cell viability in the bioreactor. Adding cells to the bioreactor could partially restore ethanol production to 75% of its initial value.

  10. Decolorization of Distillery Spentwash (Melanoidin by Immobilized Consortium (Bacterium and Yeast Cell: Entrapped into Sodium Alginate Bead

    Directory of Open Access Journals (Sweden)

    Soni Tiwari

    2014-01-01

    Full Text Available Sugarcane distilleries use molasses for ethanol production and generate large volume of effluent containing high Biological Oxygen Demand (BOD and Chemical Oxygen Demand (COD along with melanoidin pigment. The aim of this study was to isolate potential thermotolerant melanoidin decolorizing bacterium and yeast from natural resources for consortium development and entrapped in suitable matrix for immobilization at large scale spentwash treatment. A total 58 bacteria and 24 yeast were isolated from soil sample of distillery site in which Pediococcus acidilactici B-25 and Candida tropicalis RG-09 showed higher decolorization. These two strains were used for consortium development and then entrapped in sodium alginate for the wastewater treatment in a continuous column immobilization system. The immobilized consortium cells showed maximum 85% decolorization with the optimized parameters such as 2% (w/v sodium alginate, 2% (w/v calcium chloride with 16 h curing time, 5 g alginate beads with 2 mm bead diameter. The immobilized cells of consortium in alginate beads are more efficient for the wastewater treatment and can be reused for eighteen cycles (24x18 = 432 h without any loss in their activity and 22 cycles with 72% residual activity. Immobilization of consortium cells in continuous column system is better than free culture. Among the immobilized cell bioreactors, no doubt that continuous column immobilization is a novel and efficient one which can be adopted for the treatment of industrial wastewater containing melanoidin compounds and other pollutants. A proper choice of immobilized culture, careful consideration of various design parameters for continuous column immobilization will make treatment process cost effective in the long run.

  11. Ethanol production from molasses by immobilized cells of zymomonas mobilis EMCC 1546

    International Nuclear Information System (INIS)

    Ethanol production from beet molasses by zymomonas mobilis EMCC 1546 was studied using continuous processes in which immobilized bacterial cells of Z.mobilis EMCC 1546 was grown on both sodium alginate and polyvinyl alcohol(PVA). The fermentation was performed in a shaking incubation and 1-liter ferment or with final working 750 ml. The initial sugar concentration studied was 50, 100,150, 200 and 250 g/l. The results showed that optimum initial sugar for ethanol production was 200 g/l. In batch fermentation, the highest ethanol concentration was 28.50 g/. Also effect of gamma irradiation was studied to enhance ethanol production. The highest ethanol production at dose dose 0.25 kGy was 34.82 g/l. The results showed that continuous fermentation, at dilution rate 1.36 (I/h), helped to increase the ethanol production significantly and continuous fermentation with immobilized cells in alginate gave higher ethanol production, 35.8 (g/I), as compared with those immobilized in hydrogel (PVA)

  12. Cane molasses fermentation for continuous ethanol production in an immobilized cells reactor by Saccharomyces cerevisiae

    Energy Technology Data Exchange (ETDEWEB)

    Ghorbani, Farshid; Younesi, Habibollah; Esmaeili Sari, Abbas [Department of Environmental Science, Faculty of Natural Resources and Marine Sciences, Tarbiat Modares University, Noor, P.O. Box: 64414-356 (Iran); Najafpour, Ghasem [Department of Chemical Engineering, Faculty of Engineering, Noshirvani University of Technology, Babol (Iran)

    2011-02-15

    Sodium-alginate immobilized yeast was employed to produce ethanol continuously using cane molasses as a carbon source in an immobilized cell reactor (ICR). The immobilization of Saccharomyces cerevisiae was performed by entrapment of the cell cultured media harvested at exponential growth phase (16 h) with 3% sodium alginate. During the initial stage of operation, the ICR was loaded with fresh beads of mean diameter of 5.01 mm. The ethanol production was affected by the concentration of the cane molasses (50, 100 and 150 g/l), dilution rates (0.064, 0.096, 0.144 and 0.192 h{sup -1}) and hydraulic retention time (5.21, 6.94, 10.42 and 15.63 h) of the media. The pH of the feed medium was set at 4.5 and the fermentation was carried out at an ambient temperature. The maximum ethanol production, theoretical yield (Y{sub E/S}), volumetric ethanol productivity (Q{sub P}) and total sugar consumption was 19.15 g/l, 46.23%, 2.39 g l{sup -1} h{sup -1} and 96%, respectively. (author)

  13. Radioresistance of mice cells immobilized by adhesion in glass layer

    International Nuclear Information System (INIS)

    Phagocytic leukocytes are involved in bio compatibility and biodegradation processes at which materials utilized in different at which materials utilized in different types of implants are submitted. In this work round shape glass cover slips were implanted subcutaneously in 45-day-old C57B1J 6 mice and later irradiated with a 60 Co sublethal whole-body dose of 4.0 Gy. Cover slips were removed 1,3,7 and 14 days post-implant and dyed by the hematoxylin-eosin technique. Macrophage and giant cell estimations were done in a microscope by means of an integrator eyepiece. The modifications found permit to conclude that they to exist significant differences in macrophages as a function of time after implant but not as a consequence of irradiation. (author)

  14. Cell Proliferation on Macro/Nano Surface Structure and Collagen Immobilization of 3D Polycaprolactone Scaffolds.

    Science.gov (United States)

    Park, Young-Ouk; Myung, Sung-Woon; Kook, Min-Suk; Jung, Sang-Chul; Kim, Byung-Hoon

    2016-02-01

    In this study, 3D polycaprolactone (PCL) scaffolds were fabricated by 3D printing technique. The macro/nano morphology of, 3D PCL scaffolds surface was etched with oxygen plasma. Acrylic acid (AA) plasma-polymerization was performed to functionalize the macro/nano surface with carboxyl groups and then collagen was immobilized with plasma-polymerized 3D PCL scaffolds. After O2 plasma and AA plasma-polymerization, contact angles were decreased. The FE-SEM and AFM results showed that O2 plasma is increased the surface roughness. The MTT assay results showed that proliferation of the M3CT3-E1 cells increased on the oxygen plasma treated and collagen immobilized 3D PCL scaffolds. PMID:27433597

  15. BIOSORPTION OF TEXTILE DYE USING IMMOBILIZED BACTERIAL (PSEUDOMONAS AERUGINOSA AND FUNGAL (PHANEROCHATE CHRYSOSPORIUM CELLS

    Directory of Open Access Journals (Sweden)

    Natarajan Saravanan

    2013-01-01

    Full Text Available Wastewater containing dyes presents a serious problem due to its high toxicity which leads to creating enormous environmental pollution and ecological hazards. Therefore the removal of the high stable dyes from the textile effluents is of major importance. The purpose of this study is to remove the reactive dye Procion Blue 2G from textile dye solution by biosorption process using immobilized cells of Pseudomonas aeruginosa and Phanerochate chrysosporium. It was found that maximum dye uptake is 1.648 mg g-1 of bead for P. aeruginosa and it is 1.242 mg g-1 of bead for P. chrysosporium. Both the results are derived from higher initial dye concentration (100 mg L-1 and high cell concentration (in terms of volume of inoculum 20 mL and at low mass of biosorbent (5 g of bead. Comparatively better results are produced by the beads having the cells of P. aeruginosa than P. chrysosporium. Further, due to the cell immobilization, both the cell beads can be utilized repeatedly in continuous reactors by selecting suitable eluent in industrial scale with the advantage of avoiding wash out of cells.

  16. Immobilization of yeast cells on hydrogel carriers obtained by radiation-induced polymerization

    Science.gov (United States)

    Xin, Lu Zhao; Carenza, Mario; Kaetsu, Isao; Kumakura, Minoru; Yoshida, Masaru; Fujimura, Takashi

    Polymer hydrogels were obtained by radiation-induced copolymerization at -78°C of aqueous solutions of acrylic and methacrylic esters. The matrices were characterized by equilibrium water content measurements, by optical microscopy observations and by scanning electron microscopy analysis. Yeast cells were immobilized on these hydrogels and the ethanol productivity by batch fermentation was determined. Matrix hydrophilicity and porosity were found to deeply influence the adhesion of yeast cells and, hence, the ethanol productivity. The latter as well as other physico-chemical properties were also affected by the presence of a crosslinking agent added in small amounts to the polymerizing mixture.

  17. Immobilization of yeast cells on hydrogel carriers obtained by radiation-induced polymerization

    International Nuclear Information System (INIS)

    Polymer hydrogels were obtained by radiation-induced copolymerization at -78oC of aqueous solutions of acrylic and methacrylic esters. The matrices were characterized by equilibrium water content measurements, by optical microscopy observations and by scanning electron microscopy analysis. Yeast cells were immobilized on these hydrogels and the ethanol productivity by batch fermentation was determined. Matrix hydrophilicity and porosity were found to deeply influence the adhesion of yeast cells and, hence, the ethanol productivity. The latter as well as other physico-chemical properties were also affected by the presence of a crosslinking agent added in small amounts to the polymerizating mixture. (author)

  18. Long-term Continuous Production of Monoclonal Antibody by Hybridoma Cells Immobilized in a Fibrous-Bed Bioreactor

    OpenAIRE

    Zhu, Hui; Yang, Shang-Tian

    2004-01-01

    The kinetics and long-term stability of continuous production of monoclonal antibody IgG2b by hybridoma HD-24 cells immobilized in a fibrous-bed bioreactor (FBB) were studied for a period of ∼8 months. The cells were immobilized in the fibrous bed by surface attachment of cells and entrapment of large cell clumps in the void space of the fibrous matrix. A high viable cell density of 1.01 × 108/ml was attained in the bioreactor, which was about 63 times higher than those in conventional T-flas...

  19. Immobilization by Polyurethane of Pseudomonas dacunhae Cells Containing l-Aspartate β-Decarboxylase Activity and Application to l-Alanine Production

    OpenAIRE

    Fusee, Murray C.; Weber, Jennifer E.

    1984-01-01

    Whole cells of Pseudomonas dacunhae containing l-aspartate β-decarboxylase activity were immobilized by mixing a cell suspension with a liquid isocyanate-capped polyurethane prepolymer (Hypol; W. R. Grace & Co., Lexington, Mass.). The immobilized cell preparation was used to convert l-aspartic acid to l-alanine. Properties of the immobilized P. dacunhae cells containing aspartate β-decarboxylase activity were investigated with batch reactors. Retention of enzyme activity was observed to be as...

  20. Starvation enhances production of ethanol by immobilized cells of saccharomyces uvarum

    International Nuclear Information System (INIS)

    The cells of Saccharomyces carlsbergensis (S. uvarum) were starved for an hour to release the preformed metabolites. Starves, un starved and starved washed cells were used in shake flask experiments to produce ethanol. Starved cells with 17% (w/v) glucose yielded 7.1% (w/v) ethanol, Un starved and starved washed cells produced 6.5% and 6% ethanol respectively under similar conditions. Starved cells of S. uvarum were immobilized and cultivated in batch culture. These gave 8.0% ethanol compared against continuous culture at dilution rates of 0.08 and 0.16 h-1 which produced 8.6 and 8.0% (w/v) of ethanol. The concentration of HCO3- was measured in continuous culture which remained constant up to 45 hrs (till the end of fermentation process); this process showed a 100% theoretical yield of ethanol. (author)

  1. An Evaluation of Kinetic Parameters of Cadmium and Copper Biosorption by Immobilized Cells

    Directory of Open Access Journals (Sweden)

    Nelly Georgieva

    2007-10-01

    Full Text Available Bioremediation is the use of living organisms to reduce or eliminate environmental hazards resulting from the accumulation of toxic chemicals and other hazardous wastes. This technology is based on the utilization of microorganisms to transform organic and inorganic compounds. The filamentous yeast Trichosporon cutaneum strain R57, immobilized and free cells was cultivated as batch culture on a liquid medium in the presence of various concentrations of cadmium and copper ions. The simultaneous uptake and accumulation of Cd2+ and Cu2+ ions by Tr. cutaneum cells depending on the initial concentration of Cd2+ and Cu2+ in the medium were studied. The potential use of the free and immobilized cells of Trichosporon cutaneum to remove cadmium and copper ions, from aqueous solutions was evaluated. Two important physicochemical aspects for the evaluation of the sorption process as a unit operation are the equilibrium of sorption and the kinetics. The Cd2+ and Cu2+ ions biosorption capacities of all tested adsorbent were presented as a function of the initial concentration of metal ions within the aqueous biosorption medium. The individual, as well as bicomponent sorption kinetics of copper and cadmium ions by immobilised cells of Trichosporon cutaneum R57 is presented. A second order kinetic model obtains kinetic parameters for the copper and cadmium ions.

  2. Microchip-based Integration of Cell Immobilization, Electrophoresis, Post-column Derivatization, and Fluorescence Detection for Monitoring the Release of Dopamine from PC 12 Cells

    OpenAIRE

    Li, Michelle W.; Martin, R. Scott

    2008-01-01

    In this paper, we describe the fabrication and evaluation of a multilayer microchip device that can be used to quantitatively measure the amount of catecholamines released from PC 12 cells immobilized within the same device. This approach allows immobilized cells to be stimulated on-chip and, through rapid actuation of integrated microvalves, the products released from the cells are repeatedly injected into the electrophoresis portion of the microchip, where the analytes are separated based u...

  3. Reduction of volatile acidity of acidic wines by immobilized Saccharomyces cerevisiae cells.

    Science.gov (United States)

    Vilela, A; Schuller, D; Mendes-Faia, A; Côrte-Real, M

    2013-06-01

    Excessive volatile acidity in wines is a major problem and is still prevalent because available solutions are nevertheless unsatisfactory, namely, blending the filter-sterilized acidic wine with other wines of lower volatile acidity or using reverse osmosis. We have previously explored the use of an empirical biological deacidification procedure to lower the acetic acid content of wines. This winemaker's enological practice, which consists in refermentation associated with acetic acid consumption by yeasts, is performed by mixing the acidic wine with freshly crushed grapes, musts, or marc from a finished wine fermentation. We have shown that the commercial strain Saccharomyces cerevisiae S26 is able to decrease the volatile acidity of acidic wines with a volatile acidity higher than 1.44 g L(-1) acetic acid, with no detrimental impact on wine aroma. In this study, we aimed to optimize the immobilization of S26 cells in alginate beads for the bioreduction of volatile acidity of acidic wines. We found that S26 cells immobilized in double-layer alginate-chitosan beads could reduce the volatile acidity of an acidic wine (1.1 g L(-1) acetic acid, 12.5 % (v/v) ethanol, pH 3.12) by 28 and 62 % within 72 and 168 h, respectively, associated with a slight decrease in ethanol concentration (0.7 %). Similar volatile acidity removal efficiencies were obtained in medium with high glucose concentration (20 % w/v), indicating that this process may also be useful in the deacidification of grape musts. We, therefore, show that immobilized S. cerevisiae S26 cells in double-layer beads are an efficient alternative to improve the quality of wines with excessive volatile acidity. PMID:23361840

  4. Phytoremediation of Benzophenone and Bisphenol A by Glycosylation with Immobilized Plant Cells

    Directory of Open Access Journals (Sweden)

    Kei Shimoda

    2009-01-01

    Full Text Available Benzophenone and bisphenol A are environmental pollutions, which have been listed among “chemicals suspected of having endocrine disrupting effects” by the World Wildlife Fund, the National Institute of Environmental Health Sciences in the USA and the Japanese Environment Agency. The cultured cells of Nicotiana tabacum glycosylated benzophenone to three glycosides, 4-O-β-D-glucopyranosylbenzophenone (9%, diphenylmethyl β-D-glucopyranoside (14%, and diphenylmethyl 6-O-(β-D-glucopyranosyl-β-D-glucopyranoside (12% after 48 h incubation. On the other hand, incubation of benzophenone with immobilized cells of N. tabacum in sodium alginate gel gave products in higher yields, i.e. the yields of 4-O-β-D-glucopyranosylbenzophenone, diphenylmethyl β-D-glucopyranoside, and diphenylmethyl 6-O-(β-D-glucopyranosyl-β-D-glucopyranoside were 15, 27, and 22%, respectively. Bisphenol A was converted into three glycosides, 2,2-bis(4-β-D-glucopyranosyloxyphenylpropane (16%, 2-(4-β-D-glucopyranosyloxy-3-hydroxyphenyl-2-(4-β-D-gluco- pyranosyloxyphenyl propane (8%, and 2-(3-β-D-glucopyranosyloxy-4-hydroxyphenyl-2-(4-β-D-glucopyranosyloxyphe nylpropane (5%. Also the use of immobilized N. tabacum cells improved the yield of products; the glycosylation of bisphenol A with immobilized N. tabacum gave 2,2-bis(4-β-D-glucopyranosyloxyphenylpropane (24%, 2-(4-β-D-gluco- pyranosyloxy-3-hydroxyphenyl-2-(4-β-D-glucopyranosyloxyphenyl propane (15%, and 2-(3-β-D-glucopyranosyloxy- 4-hydroxyphenyl-2-(4-β-D-glucopyranosyloxyphenylpropane (11%.

  5. Simultaneous Alcoholic and Malolactic Fermentations by Saccharomyces cerevisiae and Oenococcus oeni Cells Co-immobilized in Alginate Beads

    Science.gov (United States)

    Bleve, Gianluca; Tufariello, Maria; Vetrano, Cosimo; Mita, Giovanni; Grieco, Francesco

    2016-01-01

    Malolactic fermentation (MLF) usually takes place after the end of alcoholic fermentation (AF). However, the inoculation of lactic acid bacteria together with yeast starter cultures is a promising system to enhance the quality and safety of wine. In recent years, the use of immobilized cell systems has been investigated, with interesting results, for the production of different fermented foods and beverages. In this study we have carried out the simultaneous immobilization of Saccharomyces cerevisiae and Oenococcus oeni in alginate beads and used them in microvinifications tests to produce Negroamaro wine. The process was monitored by chemical and sensorial analyses and dominance of starters and cell leaking from beads were also checked. Co-immobilization of S. cerevisiae and O. oeni allowed to perform an efficient fermentation process, producing low volatile acidity levels and ethanol and glycerol concentrations comparable with those obtained by cell sequential inoculum and co-inoculum of yeast and bacteria cells in free form. More importantly, co-immobilization strategy produced a significant decrease of the time requested to complete AF and MLF. The immobilized cells could be efficiently reused for the wine fermentation at least three times without any apparent loss of cell metabolic activities. This integrated biocatalytic system is able to perform simultaneously AF and MLF, producing wines similar in organoleptic traits in comparison with wines fermented following traditional sequential AF and MLF with free cell starters. The immobilized-cell system, that we here describe for the first time in our knowledge, offers many advantages over conventional free cell fermentations, including: (i) elimination of non-productive cell growth phases; (ii) feasibility of continuous processing; (iii) re-use of the biocatalyst. PMID:27379072

  6. Comparative studies for the biotechnological production of l-Lysine by immobilized cells of wild-type Corynebacterium glutamicum ATCC 13032 and mutant MH 20-22 B

    OpenAIRE

    Razak, Meerza Abdul; Viswanath, Buddolla

    2015-01-01

    Establishing a cost and time efficient approach for bioprocess optimization is desired but is challenging. In the present work, we have addressed the effectiveness of using immobilized cells for aerobic processes, behaviour of immobilized cells, optimization and upstream bioprocess analysis for the production of lysine by immobilized cells of Corynebacterium glutamicum ATCC 13032 and MH 20-22 B in stirred tank bioreactor. Optimized operational conditions for maximal yield and productivity wer...

  7. Oxygen supply for CHO cells immobilized on a packed-bed of Fibra-Cel disks.

    Science.gov (United States)

    Meuwly, F; Loviat, F; Ruffieux, P-A; Bernard, A R; Kadouri, A; von Stockar, U

    2006-03-01

    Packed-bed bioreactors (PBR) have proven to be efficient systems to culture mammalian cells at very high cell density in perfusion mode, thus leading to very high volumetric productivity. However, the immobilized cells must be continuously supplied with all nutrients in sufficient quantities to remain viable and productive over the full duration of the perfusion culture. Among all nutrients, oxygen is the most critical since it is present at very low concentration due to its low solubility in cell culture medium. This work presents the development of a model for oxygenation in a packed-bed bioreactor system. The experimental system used to develop the model was a packed-bed of Fibra-Cel disk carriers used to cultivate Chinese Hamster Ovary cells at high density ( approximately 6.1 x 10(7) cell/mL) in perfusion mode. With the help of this model, it was possible to identify if a PBR system is operated in optimal or sub-optimal conditions. Using the model, two options were proposed, which could improve the performance of the basal system by about twofold, that is, by increasing the density of immobilized cells per carrier volume from 6.1 x 10(7) to 1.2 x 10(8) cell/mL, or by increasing the packed-bed height from 0.2 to 0.4 m. Both strategies would be rather simple to test and implement in the packed-bed bioreactor system used for this study. As a result, it would be possible to achieve a substantial improvement of about twofold higher productivity as compared with the basal conditions. PMID:16358288

  8. Ferrous Sulphate Oxidation Using Acidithiobacillus Ferrooxidans Cells Immobilized in Ceramic Beads

    OpenAIRE

    Junfeng, Y.; Guoliang, L.; Wei, C.

    2007-01-01

    The immobilization of Acidithiobacillus ferrooxidans cells on ceramic beads as carrier is described. The effects of ferrous ion concentration and dilution on the kinetics of ferrous ion oxidation in a packed-bed bioreactor were studied. In a medium containing 13.91 g of ferrous ion per litre, the fastest oxidation rate was 4.21 g L–1 at a dilution rate of 0.8 h–1. The corresponding conversion was X = 70 %. At ferrous ion mass concentrations greater than = 8.34 g L–1 and dilution rates greate...

  9. Hydroxylation and biodegration of 6-methylquinoline by pseudomonads in aqueous and nonaqueous immobilized-cell bioreactors

    Energy Technology Data Exchange (ETDEWEB)

    Rothenburger, S.; Atlas, R.M. (Univ. of Louisville, KY (United States))

    1993-07-01

    Heterocyclic nitrogen compounds, including quinoline, methylquinolines, and isoquinoline, occur in creosote and various fossil fuels and are significant pollutants in soils and water. The removal of quinolines and other nitrogen and sulfur heterocyclic compounds from fuels could prevent the formation of air pollutants when fuels are burned. Although biodegradation of several quinolines has been reported, methylquinolines are particularly resistant to biodegradation. This paper describes the biotransformation and biodegradation of 6-methylquinoline by Pseudomona putida. The biotransformation of quinolines by immobilized cells in aqueous and nonaqueous systems, relevant for bioremediation systems, is also reported. 23 refs., 7 figs., 1 tab.

  10. NMR imaging of heavy metal absorption in alginate, immobilized cells, and kombu algal biosorbents.

    Science.gov (United States)

    Nestle, N F; Kimmich, R

    1996-09-01

    In this contribution, an NMR imaging study of heavy metal absorption in alginate, immobilized-cell biosorbents, and kombu (Laminaria japonica) algal biomass is presented. This method provides the good possibility of directly monitoring the time evolution of the spatial distribution of the ions in the materials. From these results, we demonstrate that rare earth ions are absorbed with a steep reaction front that can be described very well with a modified shrinking core model, while copper ions are absorbed with a more diffuse front. PMID:18629817

  11. 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.

  12. Drying of immobilized yeast cells in a spouted bed dryer with a moving draft tube

    OpenAIRE

    Dragan Povrenović; Viktor Nedović

    2010-01-01

    Brewery yeast cells immobilized in Ca-alginate were dried in a laboratory scale spouted bed with a draft tube.The experiment was conducted under variable temperatures and air flow rates. The temperature and air velocity at the bottom of the column have been varied in the range from 30 to 60 °C and from 6 to 10 m/s in a duration of 60 min. The moisture of dryied particles was in the interval of 10.00 to 21.00 g/g, while the water activity was in the range of 0.40 to 0.45 what ensures the prese...

  13. The production of cellulase in a spouted bed fermentor using cells immobilized in biomass support particles.

    Science.gov (United States)

    Webb, C; Fukuda, H; Atkinson, B

    1986-01-01

    Continuous cellulase production by Trichoderma viride QM 9123, immobilized in 6 mm diameter, spherical, stainless steel biomass support particles, has been achieved using a medium containing glucose as the main carbon source. Experiments were carried out in a 10-L spouted bed fermentor. In this type of reactor-recycled broth is used to create a jet at the base of a bed of particles, causing the particles to spout and circulate. During the circulation, particles pass through a region of high shear near the jet inlet. This effectively prevents a buildup of excess biomass and thus enables steady-state conditions to be achieved during continuous operation. Continuous production of cellulase was achieved at significantly higher yield and productivity than in conventional systems. At a dilution rate of 0.15 h(-1) (nominal washout rate for freely suspended cells is 0.012 h(-1)), the yield of cellulase on glucose was 31% higher than that measured during batch operation, while the volumetric productivity (31.5 FPA U/L. h) was 53% greater than in the batch system. The specific cellulase productivity of the immobilized cells was more than 3 times that of freely suspended cells, showing that diffusional limitations can be beneficial. This offers significant opportunity for the further development of biomass support particles and associated bioreactors. PMID:18553840

  14. Continuous production of L-phenylalanine by Rhodotorula glutinis immobilized cells using a column reactor.

    Science.gov (United States)

    El-Batal, Ahmed I

    2002-01-01

    Studies have been conducted on L-phenylalanine (L-Phe) production and phenylalanine ammonia lyase (PAL) stabilization in the presence of several optimum effectors and reducing agents under bioconversion of transcinnamic acid (t-CA) conditions during repeated batch operations. L-Phe production was maximized and reuseability of PAL catalyst was extended to eight consecutive cycles (repeated batches) in the presence of optimum effectors (glutamic acid, polyethylene glycol and glycerol), thioglycolic acid and sparging with nitrogen gas. These best optimum bioconversion conditions desensitize the PAL catalyst to substantially elevated higher substrate t-CA concentrations and inhibit inactivation of PAL enzyme over longer reaction periods compared to the control. The fed batch mode operation of bioconversion of total t-CA (300 mM) to L-Phe was superior (65.2%, conversion), comparing with conventional batch and repeated batch (58.4%, conversion) operations after 120 h. Gamma irradiation process was employed to polymerize and crosslink polyvinyl alcohol (PVA) with N,N'-methylene-bisacrylamide (BIS) agent. The use of immobilized PAL biocatalyst containing cells in PVA-BIS copolymer gel carrier produced by radiation polymerization is obviously advantageous with regards to the yield of L-Phe which was increased in average 1.2-fold when compare to those obtained with free cells during optimum bioconversion process. When comparing the magnitudes of gamma irradiation effects on immobilized entrapped yeast cells in PVA-BIS copolymer gel carrier using scanning electron microscopy it was show that yeast cells were protected and capable to overcome these conditions and had normal shape and other features as free (unirradiated) intact yeast cells. Optimum conditions for continuous production of L-Phe by PVA-BIS copolymer carrier entrapped yeast cells in a packed bed column reactor in recycle fed-batch mode were investigated. Under these optimum conditions L-Phe accumulated to

  15. Immobilization of anaerobic thermophilic bacteria for the production of cell-free thermostable. alpha. -amylases and pullulanases

    Energy Technology Data Exchange (ETDEWEB)

    Klingeberg, M. (Goettingen Univ. (Germany, F.R.). Inst. fuer Mikrobiologie); Vorlop, K.D. (Technische Univ. Braunschweig (Germany, F.R.). Inst. fuer Technische Chemie); Antranikian, G. (Technische Univ. Hamburg-Harburg, Hamburg (Germany, F. R.). Arbeitsbereich Biotechnologie 1)

    1990-08-01

    For the production of cell-free thermostable {alpha}-amylases and pullulanases various anaerobic thermophilic bacteria that belong to the genera Clostridium and Thermoanaerobacter were immobilized in calcium alginate gel beads. The entrapment of bacteria was performed in full was well as in hollow spheres. An optimal limited medium, which avoided bacterial outgrowth, was developed for the cultivation of immobilized organisms at 60deg C using 0.4% starch as substrate. Compared to non-immobilized cells these techniques allowed a significant increase (up to 5.6-fold) in the specific activities of the extracellular enzymes formed. An increase in the productivity of extracellular enzymes was observed after immobilization of bacteria in full spheres. In the case of C. thermosaccharolyticum, for instance, the productivity was raised from 90 units (U)/10{sup 12} cells up to 700 U/10{sup 12} cells. Electrophoretic analysis of the secreted proteins showed that in all cases most of the amylolytic enzymes formed were released into the culture medium. Proteins that had a molecular mass of less than 450 000 daltons could easily diffuse through the gel matrix. Cultivation of immobilized bacteria in semi-continuous and fed-batch cultures was also accompanied by an elevation in the concentration of cell-free enzymes. (orig.).

  16. Enhancing anticoagulation and endothelial cell proliferation of titanium surface by sequential immobilization of poly(ethylene glycol) and collagen

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Chang-Jiang, E-mail: swjtupcj@163.com; Hou, Yan-Hua; Ding, Hong-Yan; Dong, Yun-Xiao

    2013-12-15

    In the present study, poly(ethylene glycol) (PEG) and collagen I were sequentially immobilized on the titanium surface to simultaneously improve the anticoagulation and endothelial cell proliferation. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy analysis confirmed that PEG and collagen I were successfully immobilized on the titanium surface. Water contact angle results suggested the excellent hydrophilic surface after the immobilization. The anticoagulation experiments demonstrated that the immobilized PEG and collagen I on the titanium surface could not only obviously prevent platelet adhesion and aggregation but also prolong activated partial thromboplastin time (APTT), leading to the improved blood compatibility. Furthermore, immobilization of collagen to the end of PEG chain did not abate the anticoagulation. As compared to those on the pristine and PEG-modified titanium surfaces, endothelial cells exhibited improved proliferative profiles on the surface modified by the sequential immobilization of PEG and collagen in terms of CCK-8 assay, implying that the modified titanium may promote endothelialization without abating the blood compatibility. Our method may be used to modify the surface of blood-contacting biomaterials such as titanium to promote endothelialization and improve the anticoagulation, it may be helpful for development of the biomedical devices such as coronary stents, where endothelializaton and excellent anticoagulation are required.

  17. Application of immobilized cell preparation obtained from biomass of Gluconacetobacter xylinus bacteria in biotransformation of glycerol to dihydroxyacetone

    Directory of Open Access Journals (Sweden)

    Lidia Stasiak-Różańska

    2011-03-01

    Full Text Available Introduction. Dihydroxyacetone (DHA, being a product of glycerol oxidation by acetic acid bacteria, is an important compound widely applied in the cosmetic, food, and pharmaceutical industry, as well as in medicine. Biotransformation of glycerol to DHA is catalyzed by glycerol dehydrogenase (GlyDH, EC 1.1.1.6 bound with the cytoplasmic membrane of bacteria. An attempt was undertaken in this study to conduct glycerol biotransformation with immobilized fractions of a cell preparation with GlyDH activity. The content of dihydroxyacetone obtained with the cell preparation was compared with its content achieved in the reaction with immobilized viable cells of G. xylinus. Material and methods. Cell walls of Gluconacetobacter xylinus bacteria were disintegrated enzymatically. The resultant preparation was immobilized on calcium alginate or first separated into two fractions (precipitate and supernatant by centrifugation and then immobilized. DHA content was determined colorimetrically after the reaction with 3,5-dinitrosalicilic acid. Glycerol content was assayed with the refractometric method. Results. After 20 days of the process, the concentration of DHA obtained with immobilized whole cells reached 25 g/l. In turn, the content of DHA obtained in the same period with immobilized fractions of the cell preparation accounted for 16.9 g/l and 8.95 g/l (depending on the fraction applied. Conclusions. DHA may be obtained in the process independent of G. xylinus metabolic activity using a preparation which displays the catalytic activity of glycerol dehydrogenase and obtained as a result of disintegration of live bacterial cells. The application of such a preparation may in the future eliminate technological problems posed by the presence of bacterial cells and their metabolites in the culture medium.

  18. Biodegradation of acetonitrile by cells of Candida guilliermondii UFMG-Y65 immobilized in alginate, k-carrageenan and citric pectin

    Directory of Open Access Journals (Sweden)

    Dias João Carlos T.

    2000-01-01

    Full Text Available Different encapsulation matrices were tested for immobilized cells of Candida guilliermondii UFMG-Y65 used for acetonitrile degradation. Acetonitrile degradation by free cells and cells immobilized in Ba-alginate, kappa-carrageenan and citric pectin was studied. The rate of acetonitrile degradation was monitored for 120 h by measuring yeast growth and ammonia concentration. Different alginate concentrations did not affect cell viability, but the period of incubation in BaCl2 solution reduced the number of viable cells. Likewise, the gel nature and the matrix structure of the support resulting from the cell immobilization conditions were of fundamental importance for biocatalyst activity and performance, affecting substantially the patterns of microbial growth and enzymatic activity. Alginate-immobilized cells degraded acetonitrile more efficiently than kappa-carrageenan or citric pectin-immobilized cells.

  19. Drying of immobilized yeast cells in a spouted bed dryer with a moving draft tube

    Directory of Open Access Journals (Sweden)

    Dragan Povrenović

    2010-07-01

    Full Text Available Brewery yeast cells immobilized in Ca-alginate were dried in a laboratory scale spouted bed with a draft tube.The experiment was conducted under variable temperatures and air flow rates. The temperature and air velocity at the bottom of the column have been varied in the range from 30 to 60 °C and from 6 to 10 m/s in a duration of 60 min. The moisture of dryied particles was in the interval of 10.00 to 21.00 g/g, while the water activity was in the range of 0.40 to 0.45 what ensures the preservation of immobilized yeast as a starter and provides the biological activity of dried particles. A rehidration process of dryied particles proved that dried particles could completely restore their original shape and starting volume, while the mechanical resistance is somewhat reduced. The cells preserved in this way completely restore their catalytical activity after the rehidration.

  20. Production of organic acids by periplasmic enzymes present in free and immobilized cells of Zymomonas mobilis.

    Science.gov (United States)

    Malvessi, Eloane; Carra, Sabrina; Pasquali, Flávia Cristina; Kern, Denise Bizarro; da Silveira, Mauricio Moura; Ayub, Marco Antônio Záchia

    2013-01-01

    In this work the periplasmic enzymatic complex glucose-fructose oxidoreductase (GFOR)/glucono-δ-lactonase (GL) of permeabilized free or immobilized cells of Zymomonas mobilis was evaluated for the bioconversion of mixtures of fructose and different aldoses into organic acids. For all tested pairs of substrates with permeabilized free-cells, the best enzymatic activities were obtained in reactions with pH around 6.4 and temperatures ranging from 39 to 45 °C. Decreasing enzyme/substrate affinities were observed when fructose was in the mixture with glucose, maltose, galactose, and lactose, in this order. In bioconversion runs with 0.7 mol l(-1) of fructose and with aldose, with permeabilized free-cells of Z. mobilis, maximal concentrations of the respective aldonic acids of 0.64, 0.57, 0.51, and 0.51 mol l(-1) were achieved, with conversion yields of 95, 88, 78, and 78 %, respectively. Due to the important applications of lactobionic acid, the formation of this substance by the enzymatic GFOR/GL complex in Ca-alginate-immobilized cells was assessed. The highest GFOR/GL activities were found at pH 7.0-8.0 and temperatures of 47-50 °C. However, when a 24 h bioconversion run was carried out, it was observed that a combination of pH 6.4 and temperature of 47 °C led to the best results. In this case, despite the fact that Ca-alginate acts as a barrier for the diffusion of substrates and products, maximal lactobionic acid concentration, conversion yields and specific productivity similar to those obtained with permeabilized free-cells were achieved. PMID:23053345

  1. VITALITY AND MORPHOLOGY OF TUMOR CELLS TREATED WITH 4-TIAZOLIDINONE DERIVATIVES IMMOBILIZED ON NANOSCALE POLYMER CARRIER

    Directory of Open Access Journals (Sweden)

    N. M. Boiko

    2015-02-01

    Full Text Available A nanoscale polymeric carrier was used for delivery of novel anticancer compounds – 4-tiazolidinone derivatives – to tumor cells of different lines. It was found that such way of delivery of the above mentioned compounds to target cells significantly (approximately 10 times decreased acting cytotoxic dose of some of these compounds with preservation of similar level of their antineoplastic effect in vitro towards various mammalian tumor cells. The microscopic investigation of these cells demonstrated that under the action of some immobilized 4-tiazolidonone derivatives, there was an increase (up to 40% of the part of apoptotic cells, as well as an appearance of 10% of cells with morphologically changed nucleus, and up to 35% of cells with an increased intensity of red fluorescence of acridine orange in the lysosomes, compared with such indicators observed under the action of free form of those compounds. Thus, the applied nanoscale carrier is a perspective polymer system for delivery of anticancer drugs to target cells.

  2. Nanotextured PDMS Substrates for Enhanced Roughness and Aptamer Immobilization for Cancer Cell Capture

    Science.gov (United States)

    Islam, Muhymin; Mahmood, Arif; Bellah, Md.; Kim, Young-Tae; Iqbal, Samir

    2014-03-01

    Detection of circulating tumor cells (CTCs) in the early stages of cancer is requires very sensitive approach. Nanotextured polydimethylsiloxane (PDMS) substrates were fabricated by micro reactive ion etching (Micro-RIE) to have better control on surface morphology and to improve the affinity of PDMS surfaces to capture cancer cells using surface immobilized aptamers. The aptamers were specific to epidermal growth factor receptors (EGFR) present in cell membranes, and overexpressed in tumor cells. We also investigated the effect of nano-scale features on cell capturing by implementing various surfaces of different roughnesses. Three different recipes were used to prepare nanotextured PDMS by micro-RIE using oxygen (O2) and carbon tetrafluoride (CF4). The measured average roughness of three nanotextured PDMS surfaces were found to impact average densities of captured cells. In all cases, nanotextured PDMS facilitated cell capturing possibly due to increased effective surface area of roughened substrates at nanoscale. It was also observed that cell capture efficiency was higher for higher surface roughness. The nanotextured PDMS substrates are thus useful for cancer cytology devices.

  3. Parameters and kinetics of olive mill wastewater dephenolization by immobilized Rhodotorula glutinis cells.

    Science.gov (United States)

    Bozkoyunlu, Gaye; Takaç, Serpil

    2014-01-01

    Olive mill wastewater (OMW) with total phenol (TP) concentration range of 300-1200 mg/L was treated with alginate-immobilized Rhodotorula glutinis cells in batch system. The effects of pellet properties (diameter, alginate concentration and cell loading (CL)) and operational parameters (initial TP concentration, agitation rate and reusability of pellets) on dephenolization of OMW were studied. Up to 87% dephenolization was obtained after 120 h biodegradations. The utilization number of pellets increased with the addition of calcium ions into the biodegradation medium. The overall effectiveness factors calculated for different conditions showed that diffusional limitations arising from pellet size and pellet composition could be neglected. Mass transfer limitations appeared to be more effective at high substrate concentrations and low agitation rates. The parameters of logistic model for growth kinetics of R. glutinis in OMW were estimated at different initial phenol concentrations of OMW by curve-fitting of experimental data with the model. PMID:25244135

  4. Glucosyltransferase production by Klebsiella sp. K18 and conversion of sucrose to palatinose using immobilized cells.

    Science.gov (United States)

    Orsi, Daniela C; Kawaguti, Haroldo Y; Sato, Hélia H

    2009-01-01

    The strain Klebsiella sp. K18 produces the enzyme glucosyltransferase and catalyses the conversion of sucrose to palatinose, an alternative sugar that presents low cariogenicity. Response Surface Methodology was successfully employed to determine the optimal concentration of culture medium components. Maximum glucosyltransferase production (21.78 U mL(-1)) was achieved using the optimized medium composed by sugar cane molasses (80 g L(-1)), bacteriological peptone (7 g L(-1)) and yeast extract (20 g L(-1)), after 8 hours of fermentation at 28°C. The conversion of sucrose to palatinose was studied utilizing immobilized cells in calcium alginate. The effects of the alginate concentration (2-4%), cell mass concentration (20-40%) and substrate concentration (25-45%) were evaluated and the yield of palatinose was approximately 62.5%. PMID:24031319

  5. Power generation enhancement in novel microbial carbon capture cells with immobilized Chlorella vulgaris

    Science.gov (United States)

    Zhou, Minghua; He, Huanhuan; Jin, Tao; Wang, Hongyu

    2012-09-01

    With the increasing concerns for global climate change, a sustainable, efficient and renewable energy production from wastewater is imperative. In this study, a novel microbial carbon capture cell (MCC), is constructed for the first time by the introduction of immobilized microalgae (Chlorella vulgaris) into the cathode chamber of microbial fuel cells (MFCs) to fulfill the zero discharge of carbon dioxide. This process can achieve an 84.8% COD removal, and simultaneously the maximum power density can reach 2485.35 mW m-3 at a current density of 7.9 A m-3 and the Coulombic efficiency is 9.40%, which are 88% and 57.7% greater than that with suspended C. vulgaris, respectively. These enhancements in performance demonstrate the feasibility of an economical and effective approach for the simultaneous wastewater treatment, electricity generation and biodiesel production from microalgae.

  6. Immobilized WNT Proteins Act as a Stem Cell Niche for Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Molly Lowndes

    2016-07-01

    Full Text Available The timing, location, and level of WNT signaling are highly regulated during embryonic development and for the maintenance of adult tissues. Consequently the ability to provide a defined and directed source of WNT proteins is crucial to fully understand its role in tissue development and to mimic its activity in vitro. Here we describe a one-step immobilization technique to covalently bind WNT3A proteins as a basal surface with easy storage and long-lasting activity. We show that this platform is able to maintain adult and embryonic stem cells while also being adaptable for 3D systems. Therefore, this platform could be used for recapitulating specific stem cell niches with the goal of improving tissue engineering.

  7. Wet Chemistry and Peptide Immobilization on Polytetrafluoroethylene for Improved Cell-adhesion.

    Science.gov (United States)

    Gabriel, Matthias; Niederer, Kerstin; Frey, Holger

    2016-01-01

    Endowing materials surface with cell-adhesive properties is a common strategy in biomaterial research and tissue engineering. This is particularly interesting for already approved polymers that have a long standing use in medicine because these materials are well characterized and legal issues associated with the introduction of newly synthesized polymers may be avoided. Polytetrafluoroethylene (PTFE) is one of the most frequently employed materials for the manufacturing of vascular grafts but the polymer lacks cell adhesion promoting features. Endothelialization, i.e., complete coverage of the grafts inner surface with a confluent layer of endothelial cells is regarded key to optimal performance, mainly by reducing thrombogenicity of the artificial interface. This study investigates the growth of endothelial cells on peptide-modified PTFE and compares these results to those obtained on unmodified substrate. Coupling with the endothelial cell adhesive peptide Arg-Glu-Asp-Val (REDV) is performed via activation of the fluorin-containing polymer using the reagent sodium naphthalenide, followed by subsequent conjugation steps. Cell culture is accomplished using Human Umbilical Vein Endothelial Cells (HUVECs) and excellent cellular growth on peptide-immobilized material is demonstrated over a two-week period. PMID:27584937

  8. The use of microporous divinyl benzene copolymer for yeast cell immobilization and ethanol production in packed-bed reactor.

    Science.gov (United States)

    Karagöz, Pinar; Erhan, Elif; Keskinler, Bülent; Ozkan, Melek

    2009-01-01

    Microporous divinyl benzene copolymer (MDBP) was used for the first time as immobilization material for Saccharomyces cerevisiae ATCC 26602 cells in a bed reactor and ethanol production from glucose was studied as a model system. A very homogenous thick layer of yeast cells were seen from the scanning electron micrographs on the outer walls of biopolymer. The dried weight of the cells was found to be approximately 2 g per gram of cell supporting material. Hydrophobic nature of polymer is an important factor increasing cell adhesion on polymer pieces. The dynamic flow conditions through the biomaterial due to its microporous architecture prevented exopolysaccharide matrix formation around cells and continuous washing out of toxic metabolites and dead and degraded cells from the reactor provided less diffusional limitations and dynamic living environment to the cells. In order to see the ethanol production performance of immobilized yeast cells, a large initial concentration range of glucose between 6.7 and 300 g/l was studied at 1 ml/min in continuous packed-bed reactor. The inhibition effect of glucose with increasing initial concentration was observed at above 150 g/l, a relatively high substrate concentration. The continuous fluid flow around the microenvironment of the attached cells and mass transferring ability of cell immobilized on MDBP can help in decreasing the inhibition effect of ethanol accumulation and high substrate concentration in the vicinity of the cells. PMID:18712507

  9. Immobilization of Escherichia coli Cells Containing Aspartase Activity with Polyurethane and Its Application for l-Aspartic Acid Production

    Science.gov (United States)

    Fusee, Murray C.; Swann, Wayne E.; Calton, Gary J.

    1981-01-01

    Whole cells of Escherichia coli containing aspartase activity were immobilized by mixing a cell suspension with a liquid isocyanate-capped polyurethane prepolymer (Hypol). The immobilized cell preparation was used to convert ammonium fumarate to l-aspartic acid. Properties of the immobilized E. coli cells containing aspartase were investigated with a batch reactor. A 1.67-fold increase in the l-aspartic acid production rate was observed at 37°C as compared to 25°C operating temperature. The pH optimum was broad, ranging from 8.5 to 9.2. Increasing the concentration of ammonium fumarate to 1.5 M from 1.0 M negatively affected the reaction rate. l-Aspartic acid was produced at an average rate of 2.18 × 10−4 mol/min per g (wet weight) of immobilized E. coli cells with a 37°C substrate solution consisting of 1.0 M ammonium fumarate with 1 mM Mg2+ (pH 9.0). PMID:16345865

  10. Biodiesel Production: Utilization of Loofah Sponge to Immobilize Rhizopus chinensis CGMCC #3.0232 Cells as a Whole-Cell Biocatalyst.

    Science.gov (United States)

    He, Qiyang; Xia, Qianjun; Wang, Yuejiao; Li, Xun; Zhang, Yu; Hu, Bo; Wang, Fei

    2016-07-28

    Rhizopus chinensis cells immobilized on loofah (Luffa cylindrica) sponges were used to produce biodiesel via the transesterification of soybean oil. In whole-cell immobilization, loofah sponge is considered to be a superior alternative to conventional biomass carriers because of its biodegradable and renewable properties. During cell cultivation, Rhizopus chinensis mycelia can spontaneously and firmly adhere to the surface of loofah sponge particles. The optimal conditions for processing 9.65 g soybean oil at 40°C and 180 rpm using a 3:1 methanol-to-oil molar ratio were found to be 8% cell addition and 3-10% water content (depending on the oil's weight). Under optimal conditions, an over 90% methyl ester yield was achieved after the first reaction batch. The operational stability of immobilized Rhizopus chinensis cells was assayed utilizing a 1:1 methanol-to-oil molar ratio, thus resulting in a 16.5-fold increase in half-life when compared with immobilized cells of the widely studied Rhizopus oryzae. These results suggest that transesterification of vegetable oil using Rhizopus chinensis whole cells immobilized onto loofah sponge is an effective approach for biodiesel production. PMID:27090185

  11. Sequential ionic and thermogelation of chitosan spherical hydrogels prepared using superhydrophobic surfaces to immobilize cells and drugs

    OpenAIRE

    A. C. Lima; Correia, Clara R.; Oliveira, Mariana B.; Mano, J.F.

    2014-01-01

    Chitosan is soluble in acidic media, which makes it incompatible for the encapsulation of cells and pH-sensitive molecules. In this work, a mild chitosan-based system with two sequential gelation steps is proposed, where the model drug dexamethasone and L929 cells are immobilized inside hydrogel beads. Superhydrophobic surfaces were used to produce the spherical hydrogel particles that provided favorable conditions to encapsulate cells or bioactive agents. First, the chitosan a...

  12. Hydrogenases as catalysts for fuel cells: Strategies for efficient immobilization at electrode interfaces

    International Nuclear Information System (INIS)

    Highlights: ► This review examines hydrogenases as suitable biocatalysts for H2/O2 biofuel cells. ► It focuses on a O2, CO and temperature-resistant hydrogenase from Aquifex aeolicus. ► Electrically connected hydrogenase amount increases on carbon nanotube network. ► Hydrogenase orientation at the interface controls the electron transfer process. ► Hydrogenase insertion into liposomes enhances its stability. - Abstract: Hydrogenases are the key enzymes for hydrogen metabolism in many microorganisms. Due to the high efficiency they develop for H2 oxidation, research in the last five years has aimed towards their use as biocatalysts for H2/O2 biofuel cells to replace platinum-based chemical catalysts. We report in this review the major issues that have been addressed in view of the future development of such a novel biotechnological device. This includes enhancing the stability of either the enzyme itself or its immobilization onto conductive supports, increasing the amount of electrically connected enzymes and, finally, controlling hydrogenase orientation at the electrode surface, and hence the electron transfer process. We specifically focus on a particular [NiFe] membrane-bound hydrogenase purified from the hyperthermophilic and microaerophilic bacterium Aquifex aeolicus. This enzyme resists to O2, CO, and high temperatures making it potentially efficient as a biocatalyst. Recent progress in these domains strengthens the credibility of a viable H2/O2 biofuel cell and opens new avenues for biofuel cell design.

  13. Trans-membrane electron transfer in red blood cells immobilized in a chitosan film on a glassy carbon electrode

    International Nuclear Information System (INIS)

    We have studied the trans-membrane electron transfer in human red blood cells (RBCs) immobilized in a chitosan film on a glassy carbon electrode (GCE). Electron transfer results from the presence of hemoglobin (Hb) in the RBCs. The electron transfer rate (ks) of Hb in RBCs is 0.42 s−1, and <1.13 s−1 for Hb directly immobilized in the chitosan film. Only Hb molecules in RBCs that are closest to the plasma membrane and the surface of the electrode can undergo electron transfer to the electrode. The immobilized RBCs displayed sensitive electrocatalytic response to oxygen and hydrogen peroxide. It is believed that this cellular biosensor is of potential significance in studies on the physiological status of RBCs based on observing their electron transfer on the modified electrode. (author)

  14. Decolorization of industrial synthetic dyes using engineered Pseudomonas putida cells with surface-immobilized bacterial laccase

    Directory of Open Access Journals (Sweden)

    Wang Wei

    2012-06-01

    Full Text Available Abstract Background Microbial laccases are highly useful in textile effluent dye biodegradation. However, the bioavailability of cellularly expressed or purified laccases in continuous operations is usually limited by mass transfer impediment or enzyme regeneration difficulty. Therefore, this study develops a regenerable bacterial surface-displaying system for industrial synthetic dye decolorization, and evaluates its effects on independent and continuous operations. Results A bacterial laccase (WlacD was engineered onto the cell surface of the solvent-tolerant bacterium Pseudomonas putida to construct a whole-cell biocatalyst. Ice nucleation protein (InaQ anchor was employed, and the ability of 1 to 3 tandemly aligned N-terminal repeats to direct WlacD display were compared. Immobilized WlacD was determined to be surface-displayed in functional form using Western blot analysis, immunofluorescence microscopy, flow cytometry, and whole-cell enzymatic activity assay. Engineered P. putida cells were then applied to decolorize the anthraquinone dye Acid Green (AG 25 and diazo-dye Acid Red (AR 18. The results showed that decolorization of both dyes is Cu2+- and mediator-independent, with an optimum temperature of 35°C and pH of 3.0, and can be stably performed across a temperature range of 15°C to 45°C. A high activity toward AG25 (1 g/l with relative decolorization values of 91.2% (3 h and 97.1% (18 h, as well as high activity to AR18 (1 g/l by 80.5% (3 h and 89.0% (18 h, was recorded. The engineered system exhibited a comparably high activity compared with those of separate dyes in a continuous three-round shake-flask decolorization of AG25/AR18 mixed dye (each 1 g/l. No significant decline in decolorization efficacy was noted during first two-rounds but reaction equilibriums were elongated, and the residual laccase activity eventually decreased to low levels. However, the decolorizing capacity of the system was easily retrieved

  15. Hydrodynamic guiding for addressing subsets of immobilized cells and molecules in microfluidic systems

    Directory of Open Access Journals (Sweden)

    Beyer Michael

    2003-07-01

    Full Text Available Abstract Background The interest in microfluidics and surface patterning is increasing as the use of these technologies in diverse biomedical applications is substantiated. Controlled molecular and cellular surface patterning is a costly and time-consuming process. Methods for keeping multiple separate experimental conditions on a patterned area are, therefore, needed to amplify the amount of biological information that can be retrieved from a patterned surface area. We describe, in three examples of biomedical applications, how this can be achieved in an open microfluidic system, by hydrodynamically guiding sample fluid over biological molecules and living cells immobilized on a surface. Results A microfluidic format of a standard assay for cell-membrane integrity showed a fast and dose-dependent toxicity of saponin on mammalian cells. A model of the interactions of human mononuclear leukocytes and endothelial cells was established. By contrast to static adhesion assays, cell-cell adhesion in this dynamic model depended on cytokine-mediated activation of both endothelial and blood cells. The microfluidic system allowed the use of unprocessed blood as sample material, and a specific and fast immunoassay for measuring the concentration of C-reactive protein in whole blood was demonstrated. Conclusion The use of hydrodynamic guiding made multiple and dynamic experimental conditions on a small surface area possible. The ability to change the direction of flow and produce two-dimensional grids can increase the number of reactions per surface area even further. The described microfluidic system is widely applicable, and can take advantage of surfaces produced by current and future techniques for patterning in the micro- and nanometer scale.

  16. Immobilization of Microbial Cells for Alcoholic and Malolactic Fermentation of Wine and Cider

    Science.gov (United States)

    Kourkoutas, Yiannis; Manojlović, Verica; Nedović, Viktor A.

    Wine- or cider-making is highly associated with biotechnology owing to the traditional nature of must fermentation.. Nowadays, there have been considerable developments in wine- or cider-making techniques affecting all phases of wine or cider production, but more importantly, the fermentation process. It is well-known that the transformation of grape must by microbial activity results in the production of wine, and the fermentation of apples (or sometimes pears) in the production of cider. In this process, a variety of compounds affecting the organoleptic profile of wine or cider are synthesized. It is also common sense that in wine- or cider-making, the main objective is to achieve an adequate quality of the product. The technological progress and the improved quality of the wines or ciders have been associated with the control of technical parameters. Herein, cell immobilization offers numerous advantages, such as enhanced fermentation productivity, ability for cell recycling, application of continuous configurations, enhanced cell stability and viability, and improvement of quality (Margaritis and Merchant 1984; Stewart and Russel 1986; Kourkoutas et al. 2004a).

  17. Modulation of Protein Adsorption and Cell Proliferation on Polyethylene Immobilized Graphene Oxide Reinforced HDPE Bionanocomposites.

    Science.gov (United States)

    Upadhyay, Rahul; Naskar, Sharmistha; Bhaskar, Nitu; Bose, Suryasarathi; Basu, Bikramjit

    2016-05-18

    The uniform dispersion of nanoparticles in a polymer matrix, together with an enhancement of interfacial adhesion is indispensable toward achieving better mechanical properties in the nanocomposites. In the context to biomedical applications, the type and amount of nanoparticles can potentially influence the biocompatibility. To address these issues, we prepared high-density polyethylene (HDPE) based composites reinforced with graphene oxide (GO) by melt mixing followed by compression molding. In an attempt to tailor the dispersion and to improve the interfacial adhesion, we immobilized polyethylene (PE) onto GO sheets by nucleophilic addition-elimination reaction. A good combination of yield strength (ca. 20 MPa), elastic modulus (ca. 600 MPa), and an outstanding elongation at failure (ca. 70%) were recorded with 3 wt % polyethylene grafted graphene oxide (PE-g-GO) reinforced HDPE composites. Considering the relevance of protein adsorption as a biophysical precursor to cell adhesion, the protein adsorption isotherms of bovine serum albumin (BSA) were determined to realize three times higher equilibrium constant (Keq) for PE-g-GO-reinforced HDPE composites as compared to GO-reinforced composites. To assess the cytocompatibility, we grew osteoblast cell line (MC3T3) and human mesenchymal stem cells (hMSCs) on HDPE/GO and HDPE/PE-g-GO composites, in vitro. The statistically significant increase in metabolically active cell over different time periods in culture for up to 6 days in MC3T3 and 7 days for hMSCs was observed, irrespective of the substrate composition. Such observation indicated that HDPE with GO or PE-g-GO addition (up to 3 wt %) can be used as cell growth substrate. The extensive proliferation of cells with oriented growth pattern also supported the fact that tailored GO addition can support cellular functionality in vitro. Taken together, the experimental results suggest that the PE-g-GO in HDPE can effectively be utilized to enhance both mechanical and

  18. Development of thrombus-resistant and cell compatible crimped polyethylene terephthalate cardiovascular grafts using surface co-immobilized heparin and collagen

    Energy Technology Data Exchange (ETDEWEB)

    Al Meslmani, Bassam, E-mail: almeslmanib@yahoo.com [Department of Pharmaceutical Technology and Biopharmaceutics, Marburg University, Ketzerbach 63, 35037 Marburg (Germany); Mahmoud, Gihan, E-mail: mahmoudg@staff.uni-marburg.de [Department of Pharmaceutical Technology and Biopharmaceutics, Marburg University, Ketzerbach 63, 35037 Marburg (Germany); Department of Pharmaceutics and Industrial Pharmacy, Helwan University, Ain Helwan, 11795 Cairo (Egypt); Strehlow, Boris, E-mail: strehlo4@staff.uni-marburg.de [Department of Pharmaceutical Technology and Biopharmaceutics, Marburg University, Ketzerbach 63, 35037 Marburg (Germany); Mohr, Eva, E-mail: mohr@staff.uni-marburg.de [Department of Pharmaceutical Technology and Biopharmaceutics, Marburg University, Ketzerbach 63, 35037 Marburg (Germany); Leichtweiß, Thomas, E-mail: Thomas.leichtweiss@phys.chemie.uni-giessen.de [Institute of Physical Chemistry, Justus-Liebig-University, Heinrich-Buff-Ring 58, 35392 Giessen (Germany); Bakowsky, Udo, E-mail: ubakowsky@aol.com [Department of Pharmaceutical Technology and Biopharmaceutics, Marburg University, Ketzerbach 63, 35037 Marburg (Germany)

    2014-10-01

    Short-term patency of polyethylene terephthalate (PET) cardiovascular grafts is determined mainly by the inherent thrombogenicity and improper endothelialization following grafts implantation. The aim of the present study was to immobilize heparin to develop thrombus resistant grafts. Additionally, collagen was co-immobilized to enhance the host cell compatibility. The synthetic woven and knitted forms of crimped PET grafts were surface modified by Denier reduction to produce functional carboxyl groups. The produced groups were used as anchor sites for covalent immobilization of heparin or co-immobilization of heparin/collagen by the end-point method. The modified surface was characterized using Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The biological activity of immobilized molecules was investigated in vitro using direct blood coagulation test, and “platelet deposition under flow condition. Furthermore, the biocompatibility of modified grafts with host cells was assessed using L929 cell as model. All modified grafts showed significant resistance against fibrin and clot formation. The number of deposited platelets on heparin-immobilized woven and knitted grafts obviously decreased by 3 fold and 2.8 fold per unit surface area respectively, while the heparin/collagen co-immobilized grafts showed only a decrease by 1.7 and 1.8 fold compared to unmodified PET. Heparin-immobilized grafts reported no significant effect on L929 cells adhesion and growth (P > 0.05), conversely, collagen co-immobilization considerably increased cell adhesion almost ∼ 1.3 fold and 2 fold per unit surface area for woven and knitted grafts respectively. Our results emphasize that immobilization of heparin minimized the inherent thrombogenicity of the PET grafts. The simultaneous co-immobilization of collagen supported host cell adhesion and growth required for the grafts biocompatibility. - Highlight: • Heparin and collagen were co-immobilized on

  19. Interaction force measurement between E. coli cells and nanoparticles immobilized surfaces by using AFM.

    Science.gov (United States)

    Zhang, Wen; Stack, Andrew G; Chen, Yongsheng

    2011-02-01

    To better understand environmental behaviors of nanoparticles (NPs), we used the atomic force microscopy (AFM) to measure interaction forces between E. coli cells and NPs immobilized on surfaces in an aqueous environment. The results showed that adhesion force strength was significantly influenced by particle size for both hematite (α-Fe(2)O(3)) and corundum (α-Al(2)O(3)) NPs whereas the effect on the repulsive force was not observed. The adhesion force decreased from 6.3±0.7nN to 0.8±0.4nN as hematite NPs increased from 26nm to 98nm in diameter. Corundum NPs exhibited a similar dependence of adhesion force on particle size. The Johnson-Kendall-Roberts (JKR) model was employed to estimate the contact area between E. coli cells and NPs, and based on the JKR model a new model that considers local effective contact area was developed. The prediction of the new model matched the size dependence of adhesion force in experimental results. Size effects on adhesion forces may originate from the difference in local effective contact areas as supported by our model. These findings provide fundamental information for interpreting the environmental behaviors and biological interactions of NPs, which barely have been addressed. PMID:20932723

  20. Interaction force measurement between E. coli cells and nanoparticles immobilized surfaces by using AFM

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Wen [Georgia Institute of Technology; Chen, Yongsheng [Georgia Institute of Technology

    2011-01-01

    To better understand environmental behaviors of nanoparticles (NPs), we used the atomic force microscopy (AFM) to measure interaction forces between E. coli cells and NPs immobilized on surfaces in an aqueous environment. The results showed that adhesion force strength was significantly influenced by particle size for both hematite ( -Fe2 O3 ) and corundum ( -Al2 O3 ) NPs whereas the effect on the repulsive force was not observed. The adhesion force decreased from 6.3 0.7 nN to 0.8 0.4 nN as hematite NPs increased from 26 nm to 98 nm in diameter. Corundum NPs exhibited a similar dependence of adhesion force on particle size. The Johnson Kendall Roberts (JKR) model was employed to estimate the contact area between E. coli cells and NPs, and based on the JKR model a new model that considers local effective contact area was developed. The prediction of the new model matched the size dependence of adhesion force in experimental results. Size effects on adhesion forces may originate from the difference in local effective contact areas as supported by our model. These findings provide fundamental information for interpreting the environmental behaviors and biological interactions of NPs, which barely have been addressed.

  1. New trends in enzyme immobilization at nanostructured interfaces for efficient electrocatalysis in biofuel cells

    International Nuclear Information System (INIS)

    Biofuel cells, and among them enzymatic biofuel cells, are expected to take part in a sustainable economy in a next future. The development of such biodevices requires significant improvements in terms of efficiency of enzyme immobilization at the electrodes, so as to enable direct electron transfer, and to increase and stabilize the current densities. Many works during the last years aimed at reaching higher current densities, thus power densities, while increasing the long term stability of the enzymatic bioelectrodes. Search for new enzymes, wild type or mutants, new entrapment procedures, but also new electrode architectures, have been targeted. This review focuses on the materials developed and involved during the last few years to meet these demands via nanostructuration of electrode interfaces. Discussion is essentially focused on cases where direct electron transfer between enzymes and electrochemical interfaces are involved. After having introduced the main reasons for the need of nanostructuration, the materials and methods that are newly developed are described. The consequences on improved performances for enzymatic bioelectrodes are discussed, and finally major challenges for future research are addressed

  2. Ethanol production from mahula (Madhuca latifolia L.) flowers with immobilized cells of Saccharomyces cerevisiae in Luffa cylindrica L. sponge discs

    Energy Technology Data Exchange (ETDEWEB)

    Behera, Shuvashish; Mohanty, Rama Chandra [Department of Botany, Utkal University, Vanivihar, Bhubaneswar 751 004, Orissa (India); Ray, Ramesh Chandra [Microbiology Laboratory, Central Tuber Crops Research Institute (Regional Centre), Bhubaneswar 751 019, Orissa (India)

    2011-01-15

    The dried spongy fruit of luffa (Luffa cylindrica L.), a cucurbitaceous crop available in abundance in tropical and sub-tropical countries has been found to be a promising material for immobilizing microbial cells. The aim of the present study was to examine the ethanol production from mahula flowers in submerged fermentation using whole cells of Saccharomyces cerevisiae immobilized in luffa sponge discs. The cells not only survived but also were physiologically active in three more cycles of fermentation without significant reduction (<5%) in ethanol production. After 96 h, there was 91.1% sugar conversion producing 223.2 g ethanol/kg flowers (1st cycle) which was 0.99%, 2.3% and 3.2% more than 2nd (221 g ethanol/kg flowers), 3rd (218 g ethanol/kg flowers) and 4th (216 g ethanol/kg flowers) cycle of fermentation, respectively. Furthermore, ethanol production by immobilized cells was 8.96% higher than the free cells. (author)

  3. The Experimental Study of the Performance of Nano-Thin Polyelectrolyte Shell for Dental Pulp Stem Cells Immobilization.

    Science.gov (United States)

    Grzeczkowicz, A; Granicka, L H; Maciejewska, I; Strawski, M; Szklarczyk, M; Borkowska, M

    2015-12-01

    Carious is the most frequent disease of mineralized dental tissues which might result in dental pulp inflammation and mortality. In such cases an endodontic treatment is the only option to prolong tooth functioning in the oral cavity; however, in the cases of severe pulpitis, especially when complicated with periodontal tissue inflammation, the endodontic treatment might not be enough to protect against tooth loss. Thus, keeping the dental pulp viable and/or possibility of the reconstruction of a viable dental pulp complex, appears to become a critical factor for carious and/or pulp inflammation treatment. The nowadays technologies, which allow handling dental pulp stem cells (DPSC), seem to bring us closer to the usage of dental stem cells for tooth tissues reconstruction. Thus, DPSC immobilized within nano-thin polymeric shells, allowing for a diffusion of produced factors and separation from bacteria, may be considered as a cover system supporting technology of dental pulp reconstruction. The DPSC were immobilized using a layer-by-layer technique within nano-thin polymeric shells constructed and modified by nanostructure involvement to ensure the layers stability and integrity as well as separation from bacterial cells. The cytotoxity of the material used for membrane production was assessed on the model of adherent cells. The performance of DPSC nano-coating was assessed in vitro. Membrane coatings showed no cytotoxicity on the immobilized cells. The presence of coating shell was confirmed with flow cytometry, atomic force microscopy and visualized with fluorescent microscopy. The transfer of immobilized DPSC within the membrane system ensuring cells integrity, viability and protection from bacteria should be considered as an alternative method for dental tissues transportation and regeneration. PMID:26682375

  4. Immobilization of Electroporated Cells for Fabrication of Cellular Biosensors: Physiological Effects of the Shape of Calcium Alginate Matrices and Foetal Calf Serum

    OpenAIRE

    Nikos Katsanakis; Andreas Katsivelis; Spiridon Kintzios

    2009-01-01

    In order to investigate the physiological effect of transfected cell immobilization in calcium alginate gels, we immobilized electroporated Vero cells in gels shaped either as spherical beads or as thin membrane layers. In addition, we investigated whether serum addition had a positive effect on cell proliferation and viability in either gel configuration. The gels were stored for four weeks in a medium supplemented or not with 20% (v/v) foetal calf serum. Throughout a culture period of four ...

  5. Potato Processing Wastewater as a Substrate for Red Pigment Production from Immobilized Gamma-Irradiated Cells of Monascus purpureus

    International Nuclear Information System (INIS)

    Although pigment production by Monascus spp. in chemically defined media is well documented (in submerged cultures and free cells), very few information is available about the use of agro-industrial wastes and immobilized cells. In this study immobilized irradiated spores (in sponge cubes) of M. purpureus (24 h age and 0.5 g cubes/50 ml medium) produced high amount of red pigment reached up to 2.32 g/I, after 4 days of incubation, compared with the amount of pigment produced by the free cells (1.84 g/I). Also, potato processing wastewater (PPW) was examined as the main culture medium for red pigment production by this fungus under optimizing culture conditions for repeated batches. The results showed that with irradiated immobilized cells, the maximum amount of red pigment production (1.96 g/I) was recorded at the second batch. Moreover, high reductions of biochemical oxygen demand (BOD); 82.6 % for this waste was obtained during the second batch. The data revealed that very little amount of soluble toxic substances in the extracted sample leading to only 8% dead chicken embryos

  6. 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.

  7. Optimization of process parameters for the continuous ethanol production by Kluyveromyces lactis immobilized cells in hydrogel copolymer carrier.

    Science.gov (United States)

    Deriase, S F; Farahat, L M; El-Batal, A I

    2001-01-01

    In the present study the optimized parameters for highest ethanol productivity by Kluyveromyces lactis immobilized cells bioreactor were obtained using the method of Lagrange multipliers. Immobilized growing yeast cells in PVA: HEMA (7%: 10%, w/w) hydrogel copolymer carrier produced by radiation polymerization were used in a packed-bed column reactor for the continuous production of ethanol from lactose at different levels of concentrations (50, 100 and 150) gL(-1). The results indicate that volumetric ethanol productivity is influenced by substrate concentration and dilution rate. The highest value 7.17 gL(-1) h(-1) is obtained at higher lactose concentration (150 gL(-1)) in feed medium and 0.3 h(-1) dilution rate. The same results have been obtained through the application of "LINGO" software for mathematical optimization. PMID:11518393

  8. An ethanol biosensor based on a bacterial cell-immobilized eggshell membrane

    Institute of Scientific and Technical Information of China (English)

    Guang Ming Wen; Shao Min Shuang; Chuan Dong; Martin M.F. Choi

    2012-01-01

    An ethanol biosensor was fabricated based on a Methylobacterium organophilium-immobilized eggshell membrane and an oxygen (O2) electrode.A linear response for ethanol was obtained in the range of 0.050-7.5 mmol/L with a detection limit of 0.025 mmol/L (S/N =3) and a R.S.D.of 2.1%.The response time was less than 100 s at room temperature and ambient pressure.The optimal loading of bacterial cells on the biosensor membrane is 40 mg (wet weight).The optimal working conditions for the microbial biosensor are pH 7.0 phosphate buffer (50 mmol/L) at 20-25 ℃.The interference test,operational and storage stability of the biosensor are studied in detail.Finally,the biosensor is applied to determine the ethanol contents in various alcohol samples and the results are comparable to that obtained by gas chromatographic method and the results are satisfactory.Our proposed biosensor provides a convenient,simple and reliable method to determine ethanol content in alcoholic drinks.

  9. New biosensor for detection of copper ions in water based on immobilized genetically modified yeast cells.

    Science.gov (United States)

    Vopálenská, Irena; Váchová, Libuše; Palková, Zdena

    2015-10-15

    Contamination of water by heavy metals represents a potential risk for both aquatic and terrestrial organisms, including humans. Heavy metals in water resources can come from various industrial activities, and drinking water can be ex-post contaminated by heavy metals such as Cu(2+) from house fittings (e.g., water reservoirs) and pipes. Here, we present a new copper biosensor capable of detecting copper ions at concentrations of 1-100 μM. This biosensor is based on cells of a specifically modified Saccharomyces cerevisiae strain immobilized in alginate beads. Depending on the concentration of copper, the biosensor beads change color from white, when copper is present in concentrations below the detection limit, to pink or red based on the increase in copper concentration. The biosensor was successfully tested in the determination of copper concentrations in real samples of water contaminated with copper ions. In contrast to analytical methods or other biosensors based on fluorescent proteins, the newly designed biosensor does not require specific equipment and allows the quick detection of copper in many parallel samples. PMID:25982723

  10. Immobilization of Electroporated Cells for Fabrication of Cellular Biosensors: Physiological Effects of the Shape of Calcium Alginate Matrices and Foetal Calf Serum

    Directory of Open Access Journals (Sweden)

    Nikos Katsanakis

    2009-01-01

    Full Text Available In order to investigate the physiological effect of transfected cell immobilization in calcium alginate gels, we immobilized electroporated Vero cells in gels shaped either as spherical beads or as thin membrane layers. In addition, we investigated whether serum addition had a positive effect on cell proliferation and viability in either gel configuration. The gels were stored for four weeks in a medium supplemented or not with 20% (v/v foetal calf serum. Throughout a culture period of four weeks, cell proliferation and cell viability were assayed by optical microscopy after provision of Trypan Blue. Non-elaborate culture conditions (room temperature, non-CO2 enriched culture atmosphere were applied throughout the experimental period in order to evaluate cell viability under less than optimal storage conditions. Immobilization of electroporated cells was associated with an initially reduced cell viability, which was gradually increased. Immobilization was associated with maintenance of cell growth for the duration of the experimental period, whereas electroporated cells essentially died after a week in suspension culture. Considerable proliferation of immobilized cells was observed in spherical alginate beads. In both gel configurations, addition of serum was associated with increased cell proliferation. The results of the present study could contribute to an improvement of the storability of biosensors based on electroporated, genetically or membrane-engineered cells.

  11. Enhancing the Viability of Lactobacillus plantarum Inoculum by Immobilizing the Cells in Calcium-Alginate Beads Incorporating Cryoprotectants

    OpenAIRE

    Kearney, Louise; Upton, Mary; Mc Loughlin, Aiden

    1990-01-01

    Many literature reports have cited the importance of the rehydration conditions of lyophilized cultures in determining viability. The rate of rehydration and the volume of fluid used have been identified as two important factors. One possible means of controlling these is by immobilizing the cells before lyophilization within a gel matrix in which the subsequent rehydration rate and fluid volume would be controlled by the properties of the gel. In this study Lactobacillus plantarum was immobi...

  12. Biooxidation of 2-phenylethanol to phenylacetic acid by whole-cell Gluconobacter oxydans biocatalyst immobilized in polyelectrolyte complex capsules

    Czech Academy of Sciences Publication Activity Database

    Bertóková, A.; Vikartovská, A.; Bučko, M.; Gemeiner, P.; Tkáč, J.; Chorvát, D.; Štefuca, V.; Neděla, Vilém

    2015-01-01

    Roč. 33, č. 2 (2015), s. 111-120. ISSN 1024-2422 R&D Projects: GA ČR(CZ) GA14-22777S Institutional support: RVO:68081731 Keywords : Gluconobacter oxydans * natural flavors * phenylacetic acid * immobilized whole-cell biocatalyst * polyelectrolyte complex capsules * environmental scanning electron microscopy Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 0.691, year: 2014

  13. Interaction between immobilized polyelectrolyte complex nanoparticles and human mesenchymal stromal cells

    Directory of Open Access Journals (Sweden)

    Woltmann B

    2014-05-01

    Full Text Available Beatrice Woltmann,1 Bernhard Torger,2,3 Martin Müller,2,3,* Ute Hempel1,*1Dresden University of Technology, Faculty of Medicine Carl Gustav Carus, Institute of Physiological Chemistry, Dresden, Germany; 2Leibniz Institute of Polymer Research Dresden, Department of Polyelectrolytes and Dispersions, Dresden, Germany; 3Dresden University of Technology, Department of Chemistry and Food Chemistry, Dresden, Germany*These authors contributed equally to this workBackground: Implant loosening or deficient osseointegration is a major problem in patients with systemic bone diseases (eg, osteoporosis. For this reason, the stimulation of the regional cell population by local and sustained drug delivery at the bone/implant interface to induce the formation of a mechanical stable bone is promising. The purpose of this study was to investigate the interaction of polymer-based nanoparticles with human bone marrow-derived cells, considering nanoparticles’ composition and surface net charge.Materials and methods: Polyelectrolyte complex nanoparticles (PECNPs composed of the polycations poly(ethyleneimine (PEI, poly(L-lysine (PLL, or (N,N-diethylaminoethyldextran (DEAE in combination with the polyanions dextran sulfate (DS or cellulose sulfate (CS were prepared. PECNPs’ physicochemical properties (size, net charge were characterized by dynamic light scattering and particle charge detector measurements. Biocompatibility was investigated using human mesenchymal stromal cells (hMSCs cultured on immobilized PECNP films (5–50 nmol·cm-2 by analysis for metabolic activity of hMSCs in dependence of PECNP surface concentration by MTS (3-[4,5-dimethylthiazol-2-yl]-5-[3-carboxymethoxyphenyl]-2-[4-sulfophenyl]-2H-tetrazolium, inner salt assay, as well as cell morphology (phase contrast microscopy.Results: PECNPs ranging between ~50 nm and 150 nm were prepared. By varying the ratio of polycations and polyanions, PECNPs with a slightly positive (PEC+NP or negative (PEC

  14. Changes in mast cells and in permeability of mesenteric microvessels under the effect of immobilization and electrostimulation

    Science.gov (United States)

    Gorizontova, M. P.

    1980-01-01

    It was shown that a reduction in the amount of mast cells in the mesentery and an increase in their degranulation was accompanied by an increase in vascular permeability of rat mesentery. It is supposed that immobilization and electrostimulation causing degranulation of mast cells prompted histamine and serotonin release from them, thus increasing the permeability of the venular portion of the microvascular bed. Prophylactic use of esculamin preparation with P-vitaminic activity decreased mast cell degranulation, which apparently prolonged the release of histamine and serotonin from them and normalized vascular permeability.

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

    International Nuclear Information System (INIS)

    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

  16. Immobilization of Lactobacillus rhamnosus in mesoporous silica-based material: An efficiency continuous cell-recycle fermentation system for lactic acid production.

    Science.gov (United States)

    Zhao, Zijian; Xie, Xiaona; Wang, Zhi; Tao, Yanchun; Niu, Xuedun; Huang, Xuri; Liu, Li; Li, Zhengqiang

    2016-06-01

    Lactic acid bacteria immobilization methods have been widely used for lactic acid production. Until now, the most common immobilization matrix used is calcium alginate. However, Ca-alginate gel disintegrated during lactic acid fermentation. To overcome this deficiency, we developed an immobilization method in which Lactobacillus rhamnosus cells were successfully encapsulated into an ordered mesoporous silica-based material under mild conditions with a high immobilization efficiency of 78.77% by using elemental analysis. We also optimized the cultivation conditions of the immobilized L. rhamnosus and obtained a high glucose conversion yield of 92.4%. Furthermore, L. rhamnosus encapsulated in mesoporous silica-based material exhibited operational stability during repeated fermentation processes and no decrease in lactic acid production up to 8 repeated batches. PMID:26803707

  17. Electrochemical characterization of methanol/O2 biofuel cell: Use of laccase biocathode immobilized with polypyrrole film and PAMAM dendrimers

    International Nuclear Information System (INIS)

    This paper describes the performance of a mediated electron transfer (MET) biocathode for a methanol/O2 biofuel cell. To this end, we employed PAMAM (polyamidoamine) dendrimers for the immobilization of laccase using 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonate) diammonium salt (ABTS) in solution or entrapped into polypyrrole films. We used the enzyme immobilized onto the carbon platform obtained either in the presence or in the absence of the electropolymerized film to determine kinetic parameters. The results point to a very similar kinetic rate conversion in both situations; however, substrate affinity seems to increase in the bioelectrode containing the entrapped substrate molecules. The electrochemical characterization tests confirmed that the electropolymerized polypyrrole film was able to retain entrapped ABTS molecules. Additionally, laccase provides enhanced catalytic oxidation current for the mediator compared with the control sample containing PAMAM dendrimer only. Compared to the control sample, which gave power density values around 0.7 μW cm−2, tests employing ABTS as mediator furnished 6 μW cm−2 when the mediator was added in solution and around 25 μW cm−2 when it was entrapped into the biocathode layers. Overall, the developed biocathode is environmentally friendly for immobilization of the enzyme laccase, being satisfactorily stable in the kinetic tests and affording good power data in the biofuel cell tests

  18. Immobilization of CotA, an extremophilic laccase from Bacillus subtilis, on glassy carbon electrodes for biofuel cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Beneyton, T.; El Harrak, A.; Griffiths, A.D.; Taly, V. [Institut de Science et d' Ingenierie Supramoleculaire, CNRS UMR, Strasbourg (France); Hellwig, P. [Institut de Chimie, Universite de Strasbourg, CNRS UMR, Strasbourg (France)

    2011-01-15

    Thanks to their high stability over a wide range of experimental conditions, extremophilic enzymes represent an interesting alternative to mesophilic enzymes as catalysts for biofuel cell applications. In the present work, we report for the first time the immobilization of a thermophilic laccase (CotA from Bacillus subtilis endospore coat) on glassy carbon electrodes functionalized via electrochemical reduction of in situ generated aminophenyl monodiazonium salts. We compare the performance of CotA-modified electrodes for the reduction of O{sub 2} to mutant variants and demonstrate that the measured electrical current is directly correlated to the catalytic efficiencies (k{sub cat}/K{sub m}) of the immobilized enzyme. CotA-modified electrodes showed an optimal operation temperature of 45-50 C and stable catalytic activity for at least 7 weeks. (author)

  19. Optimizing immobilized enzyme performance in cell-free environments to produce liquid fuels.

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Sanat

    2015-02-05

    The overall goal of this project was to optimize enzyme performance for the production of bio-diesel fuel. Enzyme immobilization has attracted much attention as a means to increase productivity. Mesorporous silica materials have been known to be best suited for immobilizing enzymes. A major challenge is to ensure that the enzymatic activity is retained after immobilization. Two major factors which drive enzymatic deactivation are protein-surface and inter-protein interactions. Previously, we studied protein stability inside pores and how to optimize protein-surface interactions to minimize protein denaturation. In this work we studied eh effect of surface curvature and chemistry on inter-protein interactions. Our goal was to find suitable immobilization supports which minimize these inter-protein interactions. Our studies carried out in the frame work of Hydrophobic-Polar (HP) model showed that enzymes immobilized inside hydrophobic pores of optimal sizes are best suited to minimize these inter-protein interactions. Besides, this study is also of biological importance to understand the role of chaperonins in protein disaggregation. Both of these aspects profited immensely with collaborations with our experimental colleague, Prof. Georges Belfort (RPI), who performed the experimental analog of our theoretical works.

  20. Ethanol production by repeated batch and continuous fermentations of blackstrap molasses using immobilized yeast cells on thin-shell silk cocoons

    International Nuclear Information System (INIS)

    Highlights: → Thin-shell silk cocoons for immobilization of Saccharomycescerevisiae. → Advantages: high mechanical strength, light weight, biocompatibility and high surface area. → Enhanced cell stability and ethanol productivity by the immobilization system. -- Abstract: A thin-shell silk cocoon (TSC), a residual from the silk industry, is used as a support material for the immobilization of Saccharomyces cerevisiae M30 in ethanol fermentation because of its properties such as high mechanical strength, light weight, biocompatibility and high surface area. In batch fermentation with blackstrap molasses as the main fermentation substrate, an optimal ethanol concentration of 98.6 g/L was obtained using a TSC-immobilized cell system at an initial reducing sugar concentration of 240 g/L. The ethanol concentration produced by the immobilized cells was 11.5% higher than that produced by the free cells. Ethanol production in five-cycle repeated batch fermentation demonstrated the enhanced stability of the immobilized yeast cells. Under continuous fermentation in a packed-bed reactor, a maximum ethanol productivity of 19.0 g/(L h) with an ethanol concentration of 52.8 g/L was observed at a 0.36 h-1 dilution rate.

  1. Immobilization by Polyurethane of Pseudomonas dacunhae Cells Containing l-Aspartate β-Decarboxylase Activity and Application to l-Alanine Production

    Science.gov (United States)

    Fusee, Murray C.; Weber, Jennifer E.

    1984-01-01

    Whole cells of Pseudomonas dacunhae containing l-aspartate β-decarboxylase activity were immobilized by mixing a cell suspension with a liquid isocyanate-capped polyurethane prepolymer (Hypol; W. R. Grace & Co., Lexington, Mass.). The immobilized cell preparation was used to convert l-aspartic acid to l-alanine. Properties of the immobilized P. dacunhae cells containing aspartate β-decarboxylase activity were investigated with batch reactors. Retention of enzyme activity was observed to be as much as 100% when cell lysis was allowed to occur before immobilization. The pH and temperature optima were determined to be 5.5 and 45°C, respectively. Immobilized P. dacunhael-aspartate β-decarboxylase activity was stabilized by the addition of 0.1 mM pyridoxal-5-phosphate and 0.1 mM α-ketoglutaric acid to a 1.7 M ammonium aspartate (pH 5.5) substrate solution. Under conditions of semicontinuous use in a batch reactor, a 2.5% loss in immobilized l-aspartate β-decarboxylase activity was observed over a 31-day period. PMID:16346636

  2. Hydrogen Photoproduction by Nutrient-Deprived Chalamydomonas reinhardtii Cells Immobilized Within Thin Alginate Films Under Aerobic and Anaerobic Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Kosourov, S. N.; Seibert, M.

    2009-01-01

    A new technique for immobilizing H{sub 2}-photoproducing green algae within a thin (<400 {micro}m) alginate film has been developed. Alginate films with entrapped sulfur/phosphorus-deprived Chlamydomonas reinhardtii, strain cc124, cells demonstrate (a) higher cell density (up to 2,000 {micro}g Chl mL{sup -1} of matrix), (b) kinetics of H{sub 2} photoproduction similar to sulfur-deprived suspension cultures, (c) higher specific rates (up to 12.5 {micro}mol mg{sup -1} Chl h{sup -1}) of H{sub 2} evolution, (d) light conversion efficiencies to H{sub 2} of over 1% and (e) unexpectedly high resistance of the H{sub 2}-photoproducing system to inactivation by atmospheric O{sub 2}. The algal cells, entrapped in alginate and then placed in vials containing 21% O{sub 2} in the headspace, evolved up to 67% of the H{sub 2} gas produced under anaerobic conditions. The results indicate that the lower susceptibility of the immobilized algal H{sub 2}-producing system to inactivation by O{sub 2} depends on two factors: (a) the presence of acetate in the medium, which supports higher rates of respiration and (b) the capability of the alginate polymer itself to effectively separate the entrapped cells from O{sub 2} in the liquid and headspace and restrict O{sub 2} diffusion into the matrix. The strategy presented for immobilizing algal cells within thin polymeric matrices shows the potential for scale-up and possible future applications.

  3. Hemicellulosic Ethanol Production by Immobilized Wild Brazilian Yeast Scheffersomyces shehatae UFMG-HM 52.2: Effects of Cell Concentration and Stirring Rate.

    Science.gov (United States)

    Antunes, F A F; Santos, J C; Chandel, A K; Milessi, T S S; Peres, G F D; da Silva, S S

    2016-02-01

    The use of sugarcane bagasse hemicellulosic hydrolysates presents an interesting alternative to second generation (2G) ethanol production. Techniques to enhance the fermentation process, e.g., the use of immobilized cells, is one of the key factors for efficient production. Here, the effect of two important parameters (cell concentration in immobilized system and stirring rate) on the 2G ethanol production using the wild Brazilian yeast S. shehatae UFMG-HM 52.2 immobilized in calcium alginate matrix are presented. A 2(2) full factorial design of experiments was carried out to evaluate the effect of cell concentrations in sodium alginate solution for immobilized bead production (3.0, 6.0, and 9.0 g/L) and stirring rate (150, 200, and 250 rpm) for 2G ethanol production. Statistical analysis showed that the use of both variables at low levels enhanced ethanol yield (YP/S). Under these process conditions, YP/S of 0.31 g/g and ethanol productivity (Qp) of 0.12 g/L h were achieved. Results showed the potential of this immobilized yeast in 2G ethanol production from C5 sugars and demonstrate the importance of adequate cell concentration in immobilized systems, a finding that stands to increase bioprocesses yields and productivity. PMID:26507335

  4. 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%.

  5. Bioactivity of immobilized hyaluronic acid derivatives regarding protein adsorption and cell adhesion

    DEFF Research Database (Denmark)

    Köwitsch, Alexander; Yang, Yuan; Ma, Ning;

    2011-01-01

    Hyaluronic acid (HA) was chemically modified either by oxidation to obtain aldehyde-HA (aHA) or 3,3'-dithiobis(propanoic hydrazide) to obtain thiol-HA (tHA) that was covalently immobilized on model substrata such as amino-terminated surfaces or gold. Knowledge about the effect of modification with...

  6. Production of isomaltulose obtained by Erwinia sp. cells submitted to different treatments and immobilized in calcium alginate

    Directory of Open Access Journals (Sweden)

    Haroldo Yukio Kawaguti

    2011-03-01

    Full Text Available In recent decades, there has been an increase in the studies of isomaltulose obtainment, due to its physicochemical properties and physiological health benefits. These properties, which include low cariogenicity, low glycemic index and greater stability, allow the use of this sweetener as a substitute for sucrose in foods; besides the fact that it can be converted to isomalt, a dietary non-cariogenic sugar alcohol used in pharmaceuticals as well as in the food industry. Isomaltulose (6-O-α-D-glucopyronosyl-1-6-D-fructofuranose is a disaccharide reducer obtained by the enzymatic conversion of sucrose - the α-glucosyltransferase enzyme. Different treatments were performed for the preparation of whole cells; lysed cells; and crude enzyme extract of Erwinia sp. D12 strain immobilized in calcium alginate. The packed bed column of granules, containing Erwinia sp. cells sonicated and immobilized in calcium alginate (CSI, reached a maximum conversion of 53-59% sucrose into isomaltulose and it presented activity for 480 hours. The converted syrup was purified and the isomaltulose crystallization was performed through the lowering of temperature. The isomaltulose crystals presented purity of 96.5%.

  7. Osteoinductive Effects of Free and Immobilized Bone Forming Peptide-1 on Human Adipose-Derived Stem Cells.

    Directory of Open Access Journals (Sweden)

    Wenyue Li

    Full Text Available Most synthetic polymeric materials currently used for bone tissue engineering lack specific signals through which cells can identify and interact with the surface, resulting in incompatibility and compromised osteogenic activity. Soluble inductive factors also have issues including a short half-live in vivo. Bone forming peptide-1 is a truncated peptide from the immature form of bone morphogenetic protein-7 (BMP-7 that displays higher osteogenic activity than full-length, mature BMP-7. In this study, we used a mussel-inspired immobilization strategy mediated by polymerization of dopamine to introduce recently discovered stimulators of bone forming peptide-1 (BFP-1 onto the surface of poly-lactic-co-glycolic acid (PLGA substrate to form a biomaterial that overcomes these challenges. Human adipose-derived stem cells (hASCs, being abundant and easy accessible, were used to test the osteogenic activity of BFP-1 and the novel biomaterial. Under osteoinductive conditions, cells treated with both BFP-1 alone and BFP-1-coated biomaterials displayed elevated expression of the osteogenic markers alkaline phosphatase (ALP, osteocalcin (OC, and RUNX2. Furthermore, hASCs associated with poly-dopamine-assisted BFP-1-immobilized PLGA (pDA-BFP-1-PLGA scaffolds promoted in vivo bone formation in nude mice. Our novel materials may hold great promise for future bone tissue engineering applications.

  8. Preservation of Bacillus firmus Strain 37 and Optimization of Cyclodextrin Biosynthesis by Cells Immobilized on Loofa Sponge

    Directory of Open Access Journals (Sweden)

    Cristiane Moriwaki

    2012-08-01

    Full Text Available The preservation of Bacillus firmus strain 37 cells by lyophilization was evaluated and response surface methodology (RSM was used to optimize the β-cyclodextrin (β-CD production by cells immobilized on loofa sponge. Interactions were studied with the variables temperature, pH and dextrin concentration using a central composite design (CCD. Immobilization time influence on β-CD production was also investigated. B. firmus strain 37 cells remained viable after one year of storage, showing that the lyophilization is a suitable method for preservation of the microorganism. From the three-dimensional diagrams and contour plots, the best conditions for β-CD production were determined: temperature 60 °C, pH 8, and 18% dextrin. Considering that the amount of dextrin was high, a new assay was carried out, in which dextrin concentrations of 10, 15, and 18% were tested and the temperature of 60 °C and pH 8 were maintained. The results achieved showed very small differences and therefore, for economic reasons, the use of 10% dextrin is suggested. Increasing the immobilization time of cells immobilized on synthetic sponge the β-CD production decreased and did not change for cells immobilized on loofa sponge. The results of this research are important for microorganism preservation and essential in the optimization of the biosynthesis of CD.

  9. Elongation of lifetime of photosynthetic biofuel-cells containing immobilized algae; Koteika aiso wo mochiita kogosei biseibutsu denchi no chojumyoka

    Energy Technology Data Exchange (ETDEWEB)

    Yagishita, T.; Sawayama, S.; Inoue, S.; Ogi, T. [National Institute for Resources and Environment, Tsukuba (Japan)

    1994-12-08

    An experimental study is performed for elongation of lifetime of photosynthetic biofuel-cells using the living blue-green algae and a mediator. In the experiment, correlation between a current generated from cultured Anabaena and the life of the cells is investigated. Anabaena is recovered from the cells after the cells are operated for 10 hours in the dark and is cultured for 10 hours under irradiation with a Xe lamp and ventilation of 3 % CO2. Thereafter, immobilized Anabaena is returned into the cells and the cells are again actuated in repetition. Three load resistances 1 K ohm, 700 ohm, 400 ohm are employed and operation time of the current is lengthened under any conditions compared with the case where the cells are continuously operated. Further, provided a generated current is limited to 0.6 mA or lower, the current is not lowered even if the cells are operated for 90 hours. It is concluded that provided Anabaena is cultured after the electricity of 6.4 mA/h per the amount of chlorophyl in Anabaena is taken out, an output of the cells is kept unchanged for a long time. 7 refs., 4 figs., 1 tab.

  10. Monitoring of dihydroxyacetone production during oxidation of glycerol by immobilized Gluconobacter oxydans cells with an enzyme biosensor.

    Science.gov (United States)

    Tkác, J; Navrátil, M; Sturdík, E; Gemeiner, P

    2001-03-01

    A bi-enzymatic biosensor for monitoring of dihydroxyacetone production during oxidation of glycerol by bacterial cells of Gluconobacter oxydans is presented. Galactose oxidase oxidizes dihydroxyacetone efficiently producing hydrogen peroxide, which reacts with co-immobilized peroxidase and ferrocene pre-adsorbed on graphite electrode. This mediator-based bi-enzymatic biosensor possesses very high sensitivity (4.7 µA/mM in phosphate buffer), low detection limit (0.8 µM, signal/noise = 3), short response time (22 s, 95% of steady-state) and broad linear range (0.002-0.55 mM in phosphate buffer). The effect of pH, temperature, type of buffer, as well as different stabilizers (combinations of a polyelectrolyte and a polyol) on the sensor performance were carefully optimized and discussed. Dihydroxyacetone produced during a batch conversion of glycerol by the pectate-immobilized bacteria in an air-lift reactor was determined by the biosensor and by reference spectrophotometric method. Both methods were compared and were in a very good correlation. The main advantage of the biosensor is a very short time needed for sample analysis (less than 1 min). PMID:11240195

  11. Manipulation of culture strategies to enhance capsaicin biosynthesis in suspension and immobilized cell cultures of Capsicum chinense Jacq. cv. Naga King Chili.

    Science.gov (United States)

    Kehie, Mechuselie; Kumaria, Suman; Tandon, Pramod

    2014-06-01

    Manipulation of culture strategies was adopted to study the influence of nutrient stress, pH stress and precursor feeding on the biosynthesis of capsaicin in suspension and immobilized cell cultures of C. chinense. Cells cultured in the absence of one of the four nutrients (ammonium and potassium nitrate for nitrate and potassium stress, potassium dihydrogen orthophosphate for phosphorus stress, and sucrose for sugar stress) influenced the accumulation of capsaicin. Among the stress factors studied, nitrate stress showed maximal capsaicin production on day 20 (505.9 ± 2.8 μg g(-1) f.wt) in immobilized cell, whereas in suspension cultures the maximum accumulation (345.5 ± 2.9 μg g(-1) f.wt) was obtained on day 10. Different pH affected capsaicin accumulation; enhanced accumulation of capsaicin (261.6 ± 3.4 μg g(-1) f.wt) was observed in suspension cultures at pH 6 on day 15, whereas in case of immobilized cultures the highest capsaicin content (433.3 ± 3.3 μg g(-1) f.wt) was obtained at pH 5 on day 10. Addition of capsaicin precursors and intermediates significantly enhanced the biosynthesis of capsaicin, incorporation of vanillin at 100 μM in both suspension and immobilized cell cultures resulted in maximum capsaicin content with 499.1 ± 5.5 μg g(-1) f.wt on day 20 and 1,315.3 ± 10 μg g(-1) f.wt on day 10, respectively. Among the different culture strategies adopted to enhance capsaicin biosynthesis in cell cultures of C. chinense, cells fed with vanillin resulted in the maximum capsaicin accumulation. The rate of capsaicin production was significantly higher in immobilized cells as compared to freely suspended cells. PMID:24141419

  12. Drying of micro-encapsulated lactic acid bacteria — Effects of trehalose and immobilization on cell survival and release properties

    Science.gov (United States)

    Li, Xiaoyan; Chen, Xiguang

    2009-03-01

    Lactic acid bacteria (LAB) were encapsulated with alginate, gelatin and trehalose additives by the extrusion method and dried at 4 °C. The microcapsules were generally spherical and had a wrinkled surface with a size of 1.7 mm ± 0.2 mm. Trehalose as a carbohydrate source in the culture medium could reduce acid production and performed no function in the positive proliferation of LAB. Using trehalose as a carbohydrate source and protective medium simultaneously had a benefit in the protection of LAB cells during the storage at 4 °C. The density of live LAB cells could be 107 CFU g-1 after 8 weeks of storage. Cells of LAB could be continuously released from the capsules from the acidic (pH 1.2) to neutral conditions (pH 6.8). The release amounts and proliferation speeds of LAB cells in neutral medium were much larger and faster than those in acidic conditions. Additionally, immobilization of LAB could improve the survival of cells when they were exposed to acidic medium (pH 1.2) with a survival rate of 76 %.

  13. Drying of Micro-Encapsulated Lactic Acid Bacteria-Effects of Trehalose and Immobilization on Cell Survival and Release Properties

    Institute of Scientific and Technical Information of China (English)

    LI Xiaoyan; CHEN Xiguang

    2009-01-01

    Lactic acid bacteria (LAB) were encapsulated with alginate, gelatin and trehalose additives by the extrusion method and dried at 4℃. The microcapsules were generally spherical and had a wrinkled surface with a size of 1.7mm±0.2mm. Trehalose as a carbohydrate source in the culture medium could reduce acid production and performed no function in the positive proliferation of LAB. Using trehalose as a carbohydrate source and protective medium simultaneously had a benefit in the protection of LAB cells during the storage at 4℃. The density of hve LAB cells could be 10- CFU g-1 after 8 weeks of storage. Cells of LAB could be con-tinuously released from the capsules from the acidic (pH 1.2) to neutral conditions (plt 6.8). The release amounts and proliferation speeds of LAB cells in neutral medium were much larger and faster than those m acidic conditions. Additionally, immobilization of LAB could improve the survival of cells when they, were exposed to acidic medium (pH 1.2) with a survival rate of 76 %.

  14. Embryonic Stem Cells Maintain an Undifferentiated State on Dendrimer-Immobilized Surface with d-Glucose Display

    Directory of Open Access Journals (Sweden)

    Masahito Taya

    2011-12-01

    Full Text Available In serial passaging cultures of mouse embryonic stem (ES cells, we employed a dendrimer-immobilized substrate that displayed d-glucose as a terminal ligand. The d-glucose-displaying dendrimer (GLU/D surface caused the ES cells to form loosely attached spherical colonies, while those on a gelatin-coated surface formed flatter colonies that were firmly attached to the surface. Despite the morphological similarities between the colonies on the GLU/D surface and aggregates on a conventional bacteriological dish, immunostaining and RT-PCR analyses revealed the maintenance of cells within the spherical colonies on the GLU/D surface in an undifferentiated state with very low expressions of primitive endoderm markers. On the bacteriological dish, however, the cells within the aggregates showed a different cellular state with partial differentiation into the primitive endoderm lineage, and the expression level increased gradually along with the number of passages. These results indicate that the GLU/D surface can be a potential tool for controlling the ES cell morphology and then govern their self-renewal and fate.

  15. Kinetic evaluation of nitrification performance in an immobilized cell membrane bioreactor.

    Science.gov (United States)

    Güven, D; Ubay Çokgör, E; Sözen, S; Orhon, D

    2016-01-01

    High rate membrane bioreactor (MBR) systems operated at extremely low sludge ages (superfast membrane bioreactors (SFMBRs)) are inefficient to achieve nitrogen removal, due to insufficient retention time for nitrifiers. Moreover, frequent chemical cleaning is required due to high biomass flux. This study aims to satisfy the nitrification in SFMBRs by using sponge as carriers, leading to the extension of the residence time of microorganisms. In order to test the limits of nitrification, bioreactor was run under 52, 5 and 2 days of carrier residence time (CRT), with a hydraulic retention time of 6 h. Different degrees of nitrification were obtained for different CRTs. Sponge immobilized SFMBR operation with short CRT resulted in partial nitrification indicating selective dominancy of ammonia oxidizers. At higher CRT, simultaneous nitrification-denitrification was achieved when accompanying with oxygen limitation. Process kinetics was determined through evaluation of the results by a modeling study. Nitrifier partition in the reactor was also identified by model calibration. PMID:27332835

  16. Biocatalytic desulfurization of diesel oil in an air-lift reactor with immobilized Gordonia nitida CYKS1 cells.

    Science.gov (United States)

    Lee, In Su; Bae, Hee-Sung; Ryu, Hee Wook; Cho, Kyung-Suk; Chang, Yong Keun

    2005-01-01

    A new type of air-lift reactor with immobilized Gordonia nitida CYKS1 cells on a fibrous support was designed and used for the biocatalytic desulfurization (BDS) of diesel oil. Its performance was evaluated at different phase ratios of the oil to the aqueous medium (or oil phase fractions) and different sucrose concentrations. When the reaction mixture contained 10% diesel oil (v/v), 61-67% of sulfur was removed as the sulfur content decreased from 202-250 to 76-90 mg L(-1) in 72 h. The sulfur content did not decrease any further because the remaining sulfur compounds were recalcitrant to BDS. During the desulfurization, the strain CYKS1 consumed hydrocarbons in the diesel oil, mainly n-alkanes with 10-26 carbons, as carbon source even though an easily available carbon source, sucrose, was supplied. PMID:15932256

  17. Design and demonstration of an immobilized-cell fluidized-bed reactor for the efficient production of ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Webb, O.F.; Scott, T.C.; Davison, B.H.; Scott, C.D.

    1994-06-01

    Initial studies have been carried out using a 4 inch ID fluidized bed reactor (FBR). This medium scale FBR was designed for scale-up. Present performance was compared with results from experiments using smaller FBRs. On-line and off-line measurement systems are also described. Zymomonas mobilis was immobilized in {kappa}-carrageenan at cell loadings of 15--50 g (dry weight) L{sup {minus}1}. The system is designed for determining optimal operation with high conversion and productivity for a variety of conditions including feedstocks, temperature, flow rate, and column sizes (from 2 to 5 meters tall). The demonstration used non-sterile feedstocks containing either industrial (light steep water) or synthetic nutrients and dextrose.

  18. Determination of ethanol in acetic acid-containing samples by a biosensor based on immobilized Gluconobacter cells

    Directory of Open Access Journals (Sweden)

    VALENTINA A. KRATASYUK

    2012-11-01

    Full Text Available Reshetilov AN, Kitova AE, Arkhipova AV, Kratasyuk VA, Rai MK. 2012. Determination of ethanol in acetic acid containing samples by a biosensor based on immobilized Gluconobacter cells. Nusantara Bioscience 4: 97-100. A biosensor based on Gluconobacter oxydans VKM B-1280 bacteria was used for detection of ethanol in the presence of acetic acid. It was assumed that this assay could be useful for controlling acetic acid production from ethanol and determining the final stage of the fermentation process. Measurements were made using a Clark electrode-based amperometric biosensor. The effect of pH of the medium on the sensor signal and the analytical parameters of the sensor (detection range, sensitivity were investigated. The residual content of ethanol in acetic acid samples was analyzed. The results of the study are important for monitoring the acetic acid production process, as they represent a method of tracking its stages

  19. The microalga Chlamydomonas reinhardtii CW-15 as a solar cell for hydrogen peroxide photoproduction. Comparison between free and immobilized cells and thylakoids for energy conversion efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Scholz, W.; Galvan, F.; Rosa, F.F. de la [Instituto de Bioquimica Vegetal y Fotosintesis, Universidad de Sevilla y CSIC, Sevilla (Spain)

    1995-11-28

    Immobilized cells and thylakoid vesicles of the microalga Chlamydomonas reinhardtii CW-15 have been developed as a solar cell because of their capabilities of producing hydrogen peroxide. This compound is an efficient and clean fuel used for rocket propulsion, motors and for heating. Hydrogen peroxide is produced by the photosystem in a catalyst cycle in which a redox mediator (methyl viologen) is reduced by electrons obtained from water by the photosynthetic apparatus of the microalga and it is re-oxidized by the oxygen dissolved in the solution. The photoproduction has been investigated using a discontinuous system with whole cells, or thylakoid vesicles, free or immobilized on alginate. The stimulation by azide as an inhibitor of catalase has also been analyzed. Under determined optimum conditions, the photoproduction by Ca-alginate entrapped cells, with a rate of 33 {mu}mol H{sub 2}O{sub 2}/mg Chl.h, was maintained for several hours with an energy conversion efficiency of 0.25%

  20. Actin Immobilization on Chitin for Purifying Myosin II: A Laboratory Exercise That Integrates Concepts of Molecular Cell Biology and Protein Chemistry

    Science.gov (United States)

    de Souza, Marcelle Gomes; Grossi, Andre Luiz; Pereira, Elisangela Lima Bastos; da Cruz, Carolina Oliveira; Mendes, Fernanda Machado; Cameron, Luiz Claudio; Paiva, Carmen Lucia Antao

    2008-01-01

    This article presents our experience on teaching biochemical sciences through an innovative approach that integrates concepts of molecular cell biology and protein chemistry. This original laboratory exercise is based on the preparation of an affinity chromatography column containing F-actin molecules immobilized on chitin particles for purifying…

  1. Mapping and identification of interferon gamma-regulated HeLa cell proteins separated by immobilized pH gradient two-dimensional gel electrophoresis

    DEFF Research Database (Denmark)

    Shaw, AC; Rossel Larsen, M; Roepstorff, P;

    1999-01-01

    magnitude of IFN-gamma responsive genes has been reported previously. Our goal is to identify and map IFN-gamma-regulated HeLa cell proteins to the two-dimensional polyacrylamide gel electrophoresis with the immobilized pH gradient (IPG) two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) system...

  2. Use of Two-Dimensional Fluorescence Spectroscopy for Monitoring of the Effect of Dimethyl Sulfoxide in the Growth and Viability of Immobilized Plant Cells

    Czech Academy of Sciences Publication Activity Database

    Vaňková, Radomíra; Kuncová, Gabriela; Podrazký, Ondřej; Gaudinová, Alena; Vaněk, Tomáš

    2003-01-01

    Roč. 57, č. 12 (2003), s. 632-635. ISSN 0354-7531 R&D Projects: GA MŠk OC 840.10; GA MŠk OC 843.10 Institutional research plan: CEZ:AV0Z4072921; CEZ:AV0Z5038910 Keywords : Two-Dimensional Fluorescence Spectroscopy * Immobilized Plant Cells * Tobacco Subject RIV: CE - Biochemistry

  3. Effects of initial pH value of the medium on the alcoholic fermentation performance of Saccharomyces cerevisiae cells immobilized on nipa leaf sheath pieces

    OpenAIRE

    Hoang Duc Toan Le; Van Viet Man Le

    2014-01-01

    Immobilized yeast on nipa leaf sheath pieces was applied to ethanol fermentation using the medium with different initial pH values (5.1, 4.5, 4.0, and 3.5). Control samples with the free yeast were also carried out under the same conditions. Low pH value of 4.0 or 3.5 significantly reduced yeast growth and increased the residual sugar level in the fermentation broths for both the immobilized and free cells. In all cases, the ethanol content produced and ethanol formation rate of the ...

  4. Effects of initial pH value of the medium on the alcoholic fermentation performance of Saccharomyces cerevisiae cells immobilized on nipa leaf sheath pieces

    Directory of Open Access Journals (Sweden)

    Hoang Duc Toan Le

    2014-12-01

    Full Text Available Immobilized yeast on nipa leaf sheath pieces was applied to ethanol fermentation using the medium with different initial pH values (5.1, 4.5, 4.0, and 3.5. Control samples with the free yeast were also carried out under the same conditions. Low pH value of 4.0 or 3.5 significantly reduced yeast growth and increased the residual sugar level in the fermentation broths for both the immobilized and free cells. In all cases, the ethanol content produced and ethanol formation rate of the immobilized yeast were 13-33% and 35-69%, respectively, higher than those of the free yeast. In addition, the residual sugar content in the immobilized yeast cultures was 2.1-20.5 times lower than that in the free yeast cultures. The yeast immobilized on nipa leaf stem pieces exhibited higher alcoholic fermentation performance than the free yeast in medium with low pH value. This support was potential for further research for application in ethanol industry.

  5. Immobilization of cross linked Col-I-OPN bone matrix protein on aminolysed PCL surfaces enhances initial biocompatibility of human adipogenic mesenchymal stem cells (hADMSC)

    Science.gov (United States)

    Kim, Young-Hee; Jyoti, Md. Anirban; Song, Ho-Yeon

    2014-06-01

    In bone tissue engineering surface modification is considered as one of the important ways of fabricating successful biocompatible material. Addition of biologically active functionality on the surfaces has been tried for improving the overall biocompatibility of the system. In this study poly-ɛ-caprolactone film surfaces have been modified through aminolysis and immobilization process. Collagen type I (COL-I) and osteopontin (OPN), which play an important role in osteogenesis, was immobilized onto PCL films followed by aminolysis treatment using 1,6-hexanediamine. Characterization of animolysed and immobilized surfaces were done by a number techniques using scanning electron microscopy (SEM), FT-IR, XPS, ninhydrin staining, SDS-PAGE and confocal microscopy and compared between the modified and un-modified surfaces. Results of the successive experiments showed that aminolysis treatment was homogeneously achieved which helped to entrap or immobilize Col-I-OPN proteins on surfaces of PCL film. In vitro studies with human adipogenic mesenchymal stem cells (hADMSC) also confirmed the attachment and proliferation of cells was better in modified PCL surfaces than the unmodified surfaces. SEM, confocal microscopy and MTT assay showed a significant increase in cell spreading, attachment and proliferations on the biofunctionalized surfaces compared to the unmodified PCL surfaces at all-time points indicating the success of surface biofunctionalization.

  6. Immobilization of cross linked Col-I–OPN bone matrix protein on aminolysed PCL surfaces enhances initial biocompatibility of human adipogenic mesenchymal stem cells (hADMSC)

    International Nuclear Information System (INIS)

    In bone tissue engineering surface modification is considered as one of the important ways of fabricating successful biocompatible material. Addition of biologically active functionality on the surfaces has been tried for improving the overall biocompatibility of the system. In this study poly-ε-caprolactone film surfaces have been modified through aminolysis and immobilization process. Collagen type I (COL-I) and osteopontin (OPN), which play an important role in osteogenesis, was immobilized onto PCL films followed by aminolysis treatment using 1,6-hexanediamine. Characterization of animolysed and immobilized surfaces were done by a number techniques using scanning electron microscopy (SEM), FT-IR, XPS, ninhydrin staining, SDS-PAGE and confocal microscopy and compared between the modified and un-modified surfaces. Results of the successive experiments showed that aminolysis treatment was homogeneously achieved which helped to entrap or immobilize Col-I–OPN proteins on surfaces of PCL film. In vitro studies with human adipogenic mesenchymal stem cells (hADMSC) also confirmed the attachment and proliferation of cells was better in modified PCL surfaces than the unmodified surfaces. SEM, confocal microscopy and MTT assay showed a significant increase in cell spreading, attachment and proliferations on the biofunctionalized surfaces compared to the unmodified PCL surfaces at all-time points indicating the success of surface biofunctionalization.

  7. Immobilization of cross linked Col-I–OPN bone matrix protein on aminolysed PCL surfaces enhances initial biocompatibility of human adipogenic mesenchymal stem cells (hADMSC)

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young-Hee; Jyoti, Md. Anirban; Song, Ho-Yeon, E-mail: songmic@sch.ac.kr

    2014-06-01

    In bone tissue engineering surface modification is considered as one of the important ways of fabricating successful biocompatible material. Addition of biologically active functionality on the surfaces has been tried for improving the overall biocompatibility of the system. In this study poly-ε-caprolactone film surfaces have been modified through aminolysis and immobilization process. Collagen type I (COL-I) and osteopontin (OPN), which play an important role in osteogenesis, was immobilized onto PCL films followed by aminolysis treatment using 1,6-hexanediamine. Characterization of animolysed and immobilized surfaces were done by a number techniques using scanning electron microscopy (SEM), FT-IR, XPS, ninhydrin staining, SDS-PAGE and confocal microscopy and compared between the modified and un-modified surfaces. Results of the successive experiments showed that aminolysis treatment was homogeneously achieved which helped to entrap or immobilize Col-I–OPN proteins on surfaces of PCL film. In vitro studies with human adipogenic mesenchymal stem cells (hADMSC) also confirmed the attachment and proliferation of cells was better in modified PCL surfaces than the unmodified surfaces. SEM, confocal microscopy and MTT assay showed a significant increase in cell spreading, attachment and proliferations on the biofunctionalized surfaces compared to the unmodified PCL surfaces at all-time points indicating the success of surface biofunctionalization.

  8. Generation of continuous packed bed reactor with PVA–alginate blend immobilized Ochrobactrum sp. DGVK1 cells for effective removal of N,N-dimethylformamide from industrial effluents

    International Nuclear Information System (INIS)

    Highlights: ► Removal of DMF was compared by free and immobilized cells of Ochrobactrum sp. DGVK1. ► Ochrobactrum sp. DGVK1 cells entrapped in PVA–alginate have shown more tolerance. ► PVA–alginate beads removed DMF even in the presence of other organic solvents. ► Removal of DMF from industrial effluents by PVA–alginate blended batch operations. ► Development of industrially feasible remediation strategy for DMF removal. - Abstract: Effective removal of dimethylformamide (DMF), the organic solvent found in industrial effluents of textile and pharma industries, was demonstrated by using free and immobilized cells of Ochrobactrum sp. DGVK1, a soil isolate capable of utilizing DMF as a sole source of carbon, nitrogen. The free cells have efficiently removed DMF from culture media and effluents, only when DMF concentration was less than 1% (v/v). Entrapment of cells either in alginate or in polyvinyl alcohol (PVA) failed to increase tolerance limits. However, the cells of Ochrobactrum sp. DGVK1 entrapped in PVA–alginate mixed matrix tolerated higher concentration of DMF (2.5%, v/v) and effectively removed DMF from industrial effluents. As determined through batch fermentation, these immobilized cells have retained viability and degradability for more than 20 cycles. A continuous packed bed reactor, generated by using PVA–alginate beads, efficiently removed DMF from industrial effluents, even in the presence of certain organic solvents frequently found in effluents along with DMF.

  9. Co-immobilization of glucoamylase and glucose oxidase for electrochemical sequential enzyme electrode for starch biosensor and biofuel cell.

    Science.gov (United States)

    Lang, Qiaolin; Yin, Long; Shi, Jianguo; Li, Liang; Xia, Lin; Liu, Aihua

    2014-01-15

    A novel electrochemical sequential biosensor was constructed by co-immobilizing glucoamylase (GA) and glucose oxidase (GOD) on the multi-walled carbon nanotubes (MWNTs)-modified glassy carbon electrode (GCE) by chemical crosslinking method, where glutaraldehyde and bovine serum albumin was used as crosslinking and blocking agent, respectively. The proposed biosensor (GA/GOD/MWNTs/GCE) is capable of determining starch without using extra sensors such as Clark-type oxygen sensor or H2O2 sensor. The current linearly decreased with the increasing concentration of starch ranging from 0.005% to 0.7% (w/w) with the limit of detection of 0.003% (w/w) starch. The as-fabricated sequential biosensor can be applicable to the detection of the content of starch in real samples, which are in good accordance with traditional Fehling's titration. Finally, a stable starch/O2 biofuel cell was assembled using the GA/GOD/MWNTs/GCE as bioanode and laccase/MWNTs/GCE as biocathode, which exhibited open circuit voltage of ca. 0.53 V and the maximum power density of 8.15 μW cm(-2) at 0.31 V, comparable with the other glucose/O2 based biofuel cells reported recently. Therefore, the proposed biosensor exhibited attractive features such as good stability in weak acidic buffer, good operational stability, wide linear range and capable of determination of starch in real samples as well as optimal bioanode for the biofuel cell. PMID:23954673

  10. Effects of Immobilized Glycosaminoglycans on the Proliferation and Differentiation of Mesenchymal Stem Cells

    OpenAIRE

    Uygun, Basak E.; Stojsih, Sarah E.; Matthew, Howard W.T.

    2009-01-01

    Mesenchymal stem cells (MSCs) are adult stem cells with potential for multilineage differentiation. They represent an attractive cell source alternative to embryonic stem cells for therapeutic applications. Optimal utilization of MSCs for tissue engineering requires improved biomaterials that can enhance their growth and direct differentiation. The biological activity of glycosaminoglycans (GAGs) has been previously exploited for use in tissue engineering applications. In this study, MSC prol...

  11. CHANGES IN LIPID CONTENT OF WINE YEASTS DURING FERMENTATION BY IMMOBILIZED CELLS

    Directory of Open Access Journals (Sweden)

    Fedor Malik

    2010-05-01

    Full Text Available Comparison of the lipid composition of immobilised and non-immobilised cells of the wine cell strain Saccharomyces cerevisiae 6C subjected to ethanol stress indicates that the whole impact of the ethanol stress on the fatty acids composition is less influenced with immobilised cells as with non- immobilised ones. The ethanol stress raised in immobilised and free cells occurrence of palmitoleic acid to the detriment of palmitic acid. The character of changes in lipid composition during immobilisation probably has an impact upon slightly increased stress resistance. The immobilised cells are as well resistive against passive membrane fluidisation by ethanol. doi:10.5219/56

  12. 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)

  13. Immobilization of Trichosporon cutaneum R 57 Cells onto Methylcellulose/SiO2 Hybrids and Biosorption of Cadmium and Copper Ions

    Directory of Open Access Journals (Sweden)

    Georgieva N.

    2009-12-01

    Full Text Available Methylcellulose/Silica (MC/SiO2 hybrids were synthesized via poly step sol-gel method. SiO2 was included into the hybrids from two silica precursors - methyltriethoxysilane (MTES and ethyltrimethoxysilane (ETMS with different quantity of organic part-5, 20 and 50 wt.%. The filamentous yeasts Trichosporon cutaneum strain R 57 was immobilized onto the synthesized MC/SiO2 hybrids. After immobilization the hybrid materials were used in the processes of sorption of cadmium and copper ions. The obtained results of protein content analysis indicated that the amount of protein increased with increasing of MC in the hybrids. It was established that the maximal efficiency of copper and cadmium removal were observed for hybrid materials containing MTES and 50 wt.% MC - 66% and 26% respectively. For ETMS and 50 wt.% MC a high value of copper removal was 56% and for cadmium - 45% removal, respectively. FTIR analysis of free and immobilized cells with metal ions was conducted. SEM images showed successful immobilization of the yeasts cells. Second order model was employed in order to investigate the kinetics of copper and cadmium biosorption.

  14. AN INTEGRATIVE WAY OF TEACHING MOLECULAR CELL BIOLOGY AND PROTEIN CHEMISTRY USING ACTIN IMMOBILIZATION ON CHITIN FOR PURIFYING MYOSIN II.

    Directory of Open Access Journals (Sweden)

    M.G. Souza

    2007-05-01

    Full Text Available Our intent is to present our experience on teaching Molecular Cell Biology andProtein Chemistry at UNIRIO through an innovative approach that includes myosin IIextraction and purification. We took advantage of the properties of muscle contractionand propose a simple method for purifying myosin II by affinity chromatography. Thisoriginal method is based on the preparation of an affinity column containing actinmolecules covalently bound to chitin particles. We propose a three-week syllabus thatincludes lectures and bench experimental work. The syllabus favors the activelearning of protein extraction and purification, as well as, of scientific concepts suchas muscle contraction, cytoskeleton structure and its importance for the living cell. Italso promotes the learning of the biotechnological applications of chitin and theapplications of protein immobilization in different industrial fields. Furthermore, theactivities also target the development of laboratorial technical abilities, thedevelopment of problem solving skills and the ability to write up a scientific reportfollowing the model of a scientific article. It is very important to mention that thissyllabus can be used even in places where a facility such as ultra-centrifugation islacking.

  15. Fabrication of Aligned Carbon Nanotube/Polycaprolactone/Gelatin Nanofibrous Matrices for Schwann Cell Immobilization

    OpenAIRE

    Shiao-Wen Tsai; Chun-Chiang Huang; Lih-Rou Rau; Fu-Yin Hsu

    2014-01-01

    In this study, we utilized a mandrel rotating collector consisting of two parallel, electrically conductive pieces of tape to fabricate aligned electrospun polycaprolactone/gelatin (PG) and carbon nanotube/polycaprolactone/gelatin (PGC) nanofibrous matrices. Furthermore, we examined the biological performance of the PGC nanofibrous and film matrices using an in vitro culture of RT4-D6P2T rat Schwann cells. Using cell adhesion tests, we found that carbon nanotube inhibited Schwann cell attach...

  16. A process for the treatment of olive mill waste waters by immobilized cells.

    Directory of Open Access Journals (Sweden)

    ElYachioui, M.

    2005-06-01

    Full Text Available Mould strains were immobilized on sawdust from woods as a solid material for the treatment of Olive Mill Waste (OMW waters. Assays were carried out in flasks. The treatment process was monitored by physico-chemical determinations including pH, polyphenols and COD, which were followed up during the incubation time. In parallel the chemical inhibitory activity of OMW was confirmed biologically by the determination of some microorganisms in the medium including the plate count, yeasts and lactic acid bacteria. Results indicated that the polyphenol degradation level was 87 %. The COD was also reduced by 60 %. The pH of the effluent increased from 4.5 to 6.6. The microbial profiles showed their best growth during the treatment period indicating a removal of the inhibitory activities from the OMW waters. The growth patterns of all microorganism groups were similar and could reach high levels in the effluent.Cepas de moho fueron inmovilizadas sobre serrín de madera como material sólido para el tratamiento de aguas residuales de un molino de aceituna (OMW. Los ensayos se realizaron en matraces. El proceso de tratamiento se monitorizó mediante determinaciones físico-químicas incluyendo pH, polifenoles y DQO, que también se analizaron durante el tiempo de incubación. En paralelo, la actividad inhibidora química de las OMW se confirma biológicamente mediante su efecto sobre algunos microorganismos incluyendo levaduras y bactérias ácido lácticas. Los resultados indicaron que los polifenoles se degradan hasta un nivel del 87 %. La DQO se redujo también al 60 %. El pH del efluente aumentó de 4.5 a 6.6. Los perfiles microbiológicos mostraron un mejor crecimiento a medida que avanzaba el tratamiento indicando una supresión de las actividades inhibidoras de las aguas (OMW. El comportamiento del crecimiento de todos los grupos de microorganismos fue similar y puede alcanzar altos niveles en el efluente

  17. A Ca-alginate particle co-immobilized with Phanerochaete chrysosporium cells and the combined cross-linked enzyme aggregates from Trametes versicolor.

    Science.gov (United States)

    Li, Yanchun; Wang, Zhi; Xu, Xudong; Jin, Liqiang

    2015-12-01

    For improving stability of immobilized white-rot fungus to treat various effluents, Phanerochaete chrysosporium cells and the combined cross-link enzyme aggregates (combi-CLEAs) prepared from Trametes versicolor were co-immobilized into the Ca-alginate gel particles in this paper. The activity yields of obtained combi-CLEAs were 42.7% for lignin peroxidases (LiPs), 31.4% for manganese peroxidases (MnPs) and 40.4% for laccase (Lac), respectively. And their specific activities were 30.2U/g as combi-CLEAs-LiPs, 9.5 U/g as combi-CLEAs-MnPs and 28.4 U/g as combi-CLEAs-Lac. Further, the present of the combi-CLEAs in the particles extremely improved their ability to degrade the dyes. Compared to the immobilized Ph. chrysosporium without the combi-CLEAs, the co-immobilized particles enhanced the decolorized rate of Acid Violet 7 (from 45.2% to 93.4%) and Basic Fuchsin (from 12.1% to 67.9%). In addition, the addition of the combi-CLEAs improved the adaptability of the white-rot fungal particles to adverse environmental conditions. PMID:26413897

  18. Biodegradation of azaarenes and creosote in aqueous and organic liquid phase immobilized cell bioreactors by bacteria isolated from creosote contaminated soil

    International Nuclear Information System (INIS)

    The biodegradation of azaarenes and coal-tar creosote was studied using aerobic bacteria isolated from creosote contaminated soil as inocula in batch cultures and in immobilized cell bioreactors. Biodegradation of quinoline, isoquinoline, and 6-methylquinoline by pure and mixed cultures yielded mono-hydroxylated metabolites as the primary products of azaarene metabolism. All azaarene degrading cultures could degrade quinoline, suggesting a common metabolic pathway based on quinoline metabolism. Mixed cultures attacking creosote degraded 2- and 3-ring polyaromatic hydrocarbons and heterocycles, but were unable to degrade 4- and 5-ring PAH. The degradation rate and loading capacity for quinoline was greatly enhanced in the bioreactors in comparison to batch cultures. The rates of isoquinoline, 6-methylquinoline degrading strain of Pseudomonas putida successfully removed 6-methylquinoline from solution in decane in a water-limited, non-aqueous liquid phase immobilized cell bioreactor. These experiments demonstrate the ability of environmental organisms to biodegrade several biologically active compounds under conditions suitable for bioremediation applications

  19. Improving bone marrow stromal cell attachment on chitosan/hydroxyapatite scaffolds by an immobilized RGD peptide

    International Nuclear Information System (INIS)

    Ample cell adhesion to scaffolds is essential for effective bone tissue engineering. Chitosan/hydroxyapatite (CS/HA) scaffolds with channel-shaped and spherically shaped pore morphologies were prepared via in situ compositing hybridization in combination with lyophilization. The sizes of channel-shaped and spherically shaped pores of the CS/HA scaffolds were 150-650 μm and 3-15 μm, respectively. The RGD peptide (Arg-Gly-Asp) was bound to the surface of CS/HA scaffolds via physical adsorption. More than 63% of RGD present in a PBS solution spontaneously adsorbed onto CS/HA scaffolds. High numbers of viable bone marrow stromal cells (BMSCs) were observed by confocal and fluorescence microscopy for cells cultured on CS/HA scaffolds with and without RGD for 3 days. BMSCs on CS/HA scaffolds with RGD (RGD-CS/HA) were incubated for 4 h under standard culture conditions, and the degree of cell adhesion was calculated. Cell adhesion to RGD-CS/HA scaffolds with different RGD concentrations was 71.6% and 80.7%, respectively. This was 30.9% and 47.5% higher than adhesion to the CS/HA scaffold without RGD, respectively. BMSCs cultured on the scaffolds for 14 days with osteogenic supplements expressed 103% higher alkaline phosphatase on the RGD-CS/HA scaffold (0.001 97 ± 0.000 31 U/L/ng), than on the unmodified scaffold (0.000 97 ± 0.000 25 U/L/ng) (p < 0.01), indicating that a RGD peptide significantly promotes osteogenic differentiation of BMSCs on CS/HA scaffolds. The results of this study indicate that RGD-CS/HA scaffolds promote initial cell adhesion, spread and differentiation toward an osteogenic phenotype.

  20. BIOSORPTION OF TEXTILE DYE USING IMMOBILIZED BACTERIAL (PSEUDOMONAS AERUGINOSA) AND FUNGAL (PHANEROCHATE CHRYSOSPORIUM) CELLS

    OpenAIRE

    Natarajan Saravanan; Tiruvenkadam Kannadasan; Chiya Ahmed Basha; Veerasamy Manivasagan

    2013-01-01

    Wastewater containing dyes presents a serious problem due to its high toxicity which leads to creating enormous environmental pollution and ecological hazards. Therefore the removal of the high stable dyes from the textile effluents is of major importance. The purpose of this study is to remove the reactive dye Procion Blue 2G from textile dye solution by biosorption process using immobilized cells of Pseudomonas aeruginosa and Phanerochate chrysosporium. It was found that maximum dye uptake ...

  1. Actinide and lanthanum accumulation by immobilized cells of a citrobacter sp. and application to the decontamination of solutions containing americium and plutonium

    International Nuclear Information System (INIS)

    Phosphatase-mediated metal bioaccumulation by a Citrobacter sp. underlies a bioprocess for the removal of heavy metals from solution, as cell-bound metal phosphate. Deposition of uranyl ion indicated a role in the biotechnological removal of americium and plutonium from wastes generated from the nuclear fuel cycle. Preliminary studies suggested a recalcitrance of tetravalent species of U(IV), Th(IV) and Zr(IV) and, by implication, Pu(IV), probably attributable to the stability of metal-ligand complexes in solution. Trials with the trivalent model, La(III), indicated probable bioaccumulation of Pu(III) and Am(III), which was confirmed by the removal of 241Am by cells immobilized in a cartridge incorporated into a flow supplemented with Am. Pu(V) and Pu(IV) wastes may be treatable via prior reduction to Pu(III), with simultaneous removal of the latter with the co-contaminant Am(III). An oxidative route, to Pu(VI), with desolubilization as HPuO2PO4 was also considered, but experiments using the analogous U(VI) (uranyl ion) demonstrated a greater efficiency of M(III) removal. Initial experiments utilized polyacrylamide gel-immobilized cells. 241Am removal also occurred with Citrobacter sp. immobilized as biofilm on reticulated foam supports, more amenable to large-scale processes

  2. Immobilization of Enzymes by Electrochemical and Chemical Oxidative Polymerization of L-DOPA to Fabricate Amperometric Biosensors and Biofuel Cells.

    Science.gov (United States)

    Dai, Mengzhen; Sun, Lingen; Chao, Long; Tan, Yueming; Fu, Yingchun; Chen, Chao; Xie, Qingji

    2015-05-27

    Electrochemical/chemical oxidative synthesis and biosensing/biofuel cell applications of poly(L-DOPA) (PD) are studied versus polydopamine (PDA) as a recent hotspot biomaterial. The enzyme electrode developed by coelectrodeposition of PD and glucose oxidase (GOx), uricase, or tyrosinase shows biosensing performance superior to that of the corresponding PDA-based enzyme electrode. The chemical oxidative polymerization of L-DOPA (PDC) by NaAuCl4 in GOx-containing neutral aqueous solution is used to immobilize GOx and gold nanoparticles (AuNPs). The thus-prepared chitosan (CS)/GOx-PDC-AuNPs/Au(plate)/Au electrode working in the first-generation biosensing mode responds linearly to glucose concentration with a sensitivity of 152 μA mM(-1) cm(-2), which is larger than those of the CS/GOx-PDAC-AuNPs/Au(plate)/Au electrode, the CS/GOx-poly(3-anilineboronic acid) (PABA)-AuNPs/Au(plate)/Au electrode, and the most reported GOx-based enzyme electrodes. This PDC-based enzyme electrode also works well in the second-generation biosensing mode and as an excellent bioanode in biofuel cell construction, probably because PD as an amino acid polymer has the higher biocompatibility and the more favorable affinity to the enzyme than PDA. The PD material of great convenience in synthesis, outstanding biocompatibility for preparing high-performance bionanocomposites, and strong capability of multifunctional coatings on many surfaces may find wide applications in diversified fields including biotechnology and surface-coating. PMID:25938891

  3. Phytoremediation of Benzophenone and Bisphenol A by Glycosylation with Immobilized Plant Cells

    OpenAIRE

    Kei Shimoda; Hatsuyuki Hamada; Hiroki Hamada

    2009-01-01

    Benzophenone and bisphenol A are environmental pollutions, which have been listed among “chemicals suspected of having endocrine disrupting effects” by the World Wildlife Fund, the National Institute of Environmental Health Sciences in the USA and the Japanese Environment Agency. The cultured cells of Nicotiana tabacum glycosylated benzophenone to three glycosides, 4-O-β-D-glucopyranosylbenzophenone (9%), diphenylmethyl β-D-glucopyranoside (14%), and diphenylmethyl 6-O-(β-D-glucopyranosyl)-β-...

  4. Monitoring of Viability of Cells Immobilized by Sol-Gel Process

    Czech Academy of Sciences Publication Activity Database

    Kuncová, Gabriela; Podrazký, Ondřej; Trögl, Josef; Ripp, S.; Demnerová, K.; Vaňková, Radomíra

    Sydney, 2003. s. 108. [International Workshop on Sol-Gel Science and Technology "Sol Gel 2003" /12./. 25.08.2003-29.08.2003, Sydney] R&D Projects: GA ČR GA104/01/0461; GA MŠk OC 840.20; GA MŠk OC 840.10 Institutional research plan: CEZ:AV0Z5038910; CEZ:AV0Z4072921 Keywords : cell entrapment * silica layer * alginate Subject RIV: CE - Biochemistry

  5. Potential of Immobilized Whole-Cell Methylocella tundrae as a Biocatalyst for Methanol Production from Methane.

    Science.gov (United States)

    Mardina, Primata; Li, Jinglin; Patel, Sanjay K S; Kim, In-Won; Lee, Jung-Kul; Selvaraj, Chandrabose

    2016-07-28

    Methanol is a versatile compound that can be biologically synthesized from methane (CH4) by methanotrophs using a low energy-consuming and environment-friendly process. Methylocella tundrae is a type II methanotroph that can utilize CH4 as a carbon and energy source. Methanol is produced in the first step of the metabolic pathway of methanotrophs and is further oxidized into formaldehyde. Several parameters must be optimized to achieve high methanol production. In this study, we optimized the production conditions and process parameters for methanol production. The optimum incubation time, substrate, pH, agitation rate, temperature, phosphate buffer and sodium formate concentration, and cell concentration were determined to be 24 h, 50% CH4, pH 7, 150 rpm, 30°C, 100 mM and 50 mM, and 18 mg/ml, respectively. The optimization of these parameters significantly improved methanol production from 0.66 to 5.18 mM. The use of alginate-encapsulated cells resulted in enhanced methanol production stability and reusability of cells after five cycles of reuse under batch culture conditions. PMID:27012239

  6. Monitoring of the Viability of Cells Immobilized by Sol-Gel Process

    Czech Academy of Sciences Publication Activity Database

    Kuncová, Gabriela; Podrazký, Ondřej; Ripp, S.; Trögl, Josef; Sayler, G. S.; Demnerová, K.; Vaňková, Radomíra

    2004-01-01

    Roč. 31, 1-3 (2004), s. 335-342. ISSN 0928-0707. [International Workshop on Sol-Gel and Technology-Part I (Sol-Gel'03) /12./. Sydney, 25.08.2003-29.08.2003] R&D Projects: GA ČR GA104/01/0461; GA MŠk OC 840.20; GA MŠk OC 840.10 Institutional research plan: CEZ:AV0Z4072921 Keywords : sol-gel process * cell entrapment * viability Subject RIV: CE - Biochemistry Impact factor: 1.150, year: 2004

  7. Laminin Peptide-Immobilized Hydrogels Modulate Valve Endothelial Cell Hemostatic Regulation.

    Directory of Open Access Journals (Sweden)

    Liezl Rae Balaoing

    Full Text Available Valve endothelial cells (VEC have unique phenotypic responses relative to other types of vascular endothelial cells and have highly sensitive hemostatic functions affected by changes in valve tissues. Furthermore, effects of environmental factors on VEC hemostatic function has not been characterized. This work used a poly(ethylene glycol diacrylate (PEGDA hydrogel platform to evaluate the effects of substrate stiffness and cell adhesive ligands on VEC phenotype and expression of hemostatic genes. Hydrogels of molecular weights (MWs 3.4, 8, and 20 kDa were polymerized into platforms of different rigidities and thiol-modified cell adhesive peptides were covalently bound to acrylate groups on the hydrogel surfaces. The peptide RKRLQVQLSIRT (RKR is a syndecan-1 binding ligand derived from laminin, a trimeric protein and a basement membrane matrix component. Conversely, RGDS is an integrin binding peptide found in many extracellular matrix (ECM proteins including fibronectin, fibrinogen, and von Willebrand factor (VWF. VECs adhered to and formed a stable monolayer on all RKR-coated hydrogel-MW combinations. RGDS-coated platforms supported VEC adhesion and growth on RGDS-3.4 kDa and RGDS-8 kDa hydrogels. VECs cultured on the softer RKR-8 kDa and RKR-20 kDa hydrogel platforms had significantly higher gene expression for all anti-thrombotic (ADAMTS-13, tissue factor pathway inhibitor, and tissue plasminogen activator and thrombotic (VWF, tissue factor, and P-selectin proteins than VECs cultured on RGDS-coated hydrogels and tissue culture polystyrene controls. Stimulated VECs promoted greater platelet adhesion than non-stimulated VECs on their respective culture condition; yet stimulated VECs on RGDS-3.4 kDa gels were not as responsive to stimulation relative to the RKR-gel groups. Thus, the syndecan binding, laminin-derived peptide promoted stable VEC adhesion on the softer hydrogels and maintained VEC phenotype and natural hemostatic function. In

  8. Laminin Peptide-Immobilized Hydrogels Modulate Valve Endothelial Cell Hemostatic Regulation.

    Science.gov (United States)

    Balaoing, Liezl Rae; Post, Allison Davis; Lin, Adam Yuh; Tseng, Hubert; Moake, Joel L; Grande-Allen, K Jane

    2015-01-01

    Valve endothelial cells (VEC) have unique phenotypic responses relative to other types of vascular endothelial cells and have highly sensitive hemostatic functions affected by changes in valve tissues. Furthermore, effects of environmental factors on VEC hemostatic function has not been characterized. This work used a poly(ethylene glycol) diacrylate (PEGDA) hydrogel platform to evaluate the effects of substrate stiffness and cell adhesive ligands on VEC phenotype and expression of hemostatic genes. Hydrogels of molecular weights (MWs) 3.4, 8, and 20 kDa were polymerized into platforms of different rigidities and thiol-modified cell adhesive peptides were covalently bound to acrylate groups on the hydrogel surfaces. The peptide RKRLQVQLSIRT (RKR) is a syndecan-1 binding ligand derived from laminin, a trimeric protein and a basement membrane matrix component. Conversely, RGDS is an integrin binding peptide found in many extracellular matrix (ECM) proteins including fibronectin, fibrinogen, and von Willebrand factor (VWF). VECs adhered to and formed a stable monolayer on all RKR-coated hydrogel-MW combinations. RGDS-coated platforms supported VEC adhesion and growth on RGDS-3.4 kDa and RGDS-8 kDa hydrogels. VECs cultured on the softer RKR-8 kDa and RKR-20 kDa hydrogel platforms had significantly higher gene expression for all anti-thrombotic (ADAMTS-13, tissue factor pathway inhibitor, and tissue plasminogen activator) and thrombotic (VWF, tissue factor, and P-selectin) proteins than VECs cultured on RGDS-coated hydrogels and tissue culture polystyrene controls. Stimulated VECs promoted greater platelet adhesion than non-stimulated VECs on their respective culture condition; yet stimulated VECs on RGDS-3.4 kDa gels were not as responsive to stimulation relative to the RKR-gel groups. Thus, the syndecan binding, laminin-derived peptide promoted stable VEC adhesion on the softer hydrogels and maintained VEC phenotype and natural hemostatic function. In conclusion

  9. Generation of continuous packed bed reactor with PVA-alginate blend immobilized Ochrobactrum sp. DGVK1 cells for effective removal of N,N-dimethylformamide from industrial effluents

    Energy Technology Data Exchange (ETDEWEB)

    Sanjeev Kumar, S.; Kumar, M. Santosh [Department of Biochemistry, Gulbarga University, Gulbarga 585106, Karnataka (India); Siddavattam, D. [Department of Animal Sciences, University of Hyderabad, Hyderabad 500046 (India); Karegoudar, T.B., E-mail: goudartbk@gmail.com [Department of Biochemistry, Gulbarga University, Gulbarga 585106, Karnataka (India)

    2012-01-15

    Highlights: Black-Right-Pointing-Pointer Removal of DMF was compared by free and immobilized cells of Ochrobactrum sp. DGVK1. Black-Right-Pointing-Pointer Ochrobactrum sp. DGVK1 cells entrapped in PVA-alginate have shown more tolerance. Black-Right-Pointing-Pointer PVA-alginate beads removed DMF even in the presence of other organic solvents. Black-Right-Pointing-Pointer Removal of DMF from industrial effluents by PVA-alginate blended batch operations. Black-Right-Pointing-Pointer Development of industrially feasible remediation strategy for DMF removal. - Abstract: Effective removal of dimethylformamide (DMF), the organic solvent found in industrial effluents of textile and pharma industries, was demonstrated by using free and immobilized cells of Ochrobactrum sp. DGVK1, a soil isolate capable of utilizing DMF as a sole source of carbon, nitrogen. The free cells have efficiently removed DMF from culture media and effluents, only when DMF concentration was less than 1% (v/v). Entrapment of cells either in alginate or in polyvinyl alcohol (PVA) failed to increase tolerance limits. However, the cells of Ochrobactrum sp. DGVK1 entrapped in PVA-alginate mixed matrix tolerated higher concentration of DMF (2.5%, v/v) and effectively removed DMF from industrial effluents. As determined through batch fermentation, these immobilized cells have retained viability and degradability for more than 20 cycles. A continuous packed bed reactor, generated by using PVA-alginate beads, efficiently removed DMF from industrial effluents, even in the presence of certain organic solvents frequently found in effluents along with DMF.

  10. Efficient biosynthesis of γ-decalactone in ionic liquids by immobilized whole cells of Yarrowia lipolytica G3-3.21 on attapulgite.

    Science.gov (United States)

    Zhao, Yuping; Xu, Yan; Jiang, Changxing

    2015-10-01

    In this study, the biosynthesis of γ-decalactone (GDL) was successfully conducted in an ionic liquid (IL)-containing cosolvent system using immobilized cells of Yarrowia lipolytica G3-3.21 on attapulgite (ATG). We found the immobilized Y. lipolytica G3-3.21 cells in N-butyl-pyridinium tetrafluoroborate ([BPy]BF4) solution gave the highest activity of C16-Acyl-CoA oxidase and the maximum yield of GDL. The optimum immobilization conditions for the highest yield of GDL were 20 g/L of ATG, 1.5 % of CaCl2 and 2 % of sodium alginate (NaAlg). The optimal [BPy]BF4 content, buffer pH, reaction temperature, shaking speed, castor oil and glucose contents were 7.5 %, 26 °C, 150 rpm, 100 g/L and 10 %, respectively. Under the optimized conditions, the GDL yield was up to 8.05 g/L. After ten times of reuse, the GDL yield was 7.51 g/L, corresponding to 93.3 % of that obtained in the first batch, suggesting a good reusability and potential for industrial applications. PMID:26091898

  11. Novel pectin-silica hybrids used for immobilization of Trichosporon cutaneum cells efficient in removal of Cadmium and Copper ions from waste water

    International Nuclear Information System (INIS)

    New silica hybrid materials containing tetramethyl siloxane (TMOS) as an inorganic precursor and apple pectin (AP) as an organic compound were prepared. The quantity of organic substance was 5 and 50 wt% AP. The amorphous state of the samples was proved by X-ray diffraction analyses (XRD). The Infrared scattering spectra (IR) showed characteristic peaks for SiO2 network, as well as for pectin. The synthesized hybrid materials were applied as matrices for cells immobilization by attachment and entrapment of the filamentous yeast Trichosporon cutaneum R57. This strain showed considerable ability to remove cadmium and copper ions from aqueous solutions. Regarding heavy metal biosorption capacity, the attachment was found to be superior compared to the entrapment method as a technique for biomass immobilization. (authors) Key words: biomaterials, composite materials, microstructure, sol-gel preparation

  12. Titanium Immobilized with an Antimicrobial Peptide Derived from Histatin Accelerates the Differentiation of Osteoblastic Cell Line, MC3T3-E1

    Directory of Open Access Journals (Sweden)

    Seicho Makihira

    2010-04-01

    Full Text Available The objective of this study was to evaluate the effect of titanium immobilized with a cationic antimicrobial peptide (JH8194 derived from histatin on the biofilm formation of Porphyromonas gingivalis and differentiation of osteoblastic cells (MC3T3-E1. The titanium specimens (Ti were immobilized with JH8194, according to the method previously described. The colonization of P. gingivalis on JH8194-Ti was significantly lower than that on control- and blocking-Ti. JH8194-Ti enhanced the mRNA expressions of Runx2 and OPN, and ALPase activity in the MC3T3-E1, as compared with those of control- and blocking-Ti. These results, taken together, suggested the possibility that JH8194-Ti may be a potential aid to shorten the period of acquiring osseointegration.

  13. Arginine-assisted immobilization of silver nanoparticles on ZnO nanorods: an enhanced and reusable antibacterial substrate without human cell cytotoxicity

    Science.gov (United States)

    Agnihotri, Shekhar; Bajaj, Geetika; Mukherji, Suparna; Mukherji, Soumyo

    2015-04-01

    Silver-based hybrid nanomaterials are gaining interest as potential alternatives for conventional antimicrobial agents. Herein, we present a simple, facile and eco-friendly approach for the deposition of silver nanoparticles (AgNPs) on ZnO nanorods, which act as a nanoreactor for in situ synthesis and as an immobilizing template in the presence of arginine. The presence of arginine enhanced the stability of ZnO deposition on the glass substrate by hindering the dissolution of zinc under alkaline conditions. Various Ag/ZnO hybrid nanorod (HNR) samples were screened to obtain a high amount of silver immobilization on the ZnO substrate. Ag/ZnO HNRs displayed potent antibacterial ability and could achieve 100% kill for both Escherichia coli and Bacillus subtilis strains under various test conditions. The hybrid material mediated its dual mode of antibacterial action through direct contact-killing and release of silver ions/nanoparticles and showed superior bactericidal performance compared to pure ZnO nanorods and colloidal AgNPs. No significant decline in antibacterial efficacy was observed even after the same substrate was repeatedly reused multiple times. Interestingly, the amount of Ag and Zn release was much below their maximal limit in drinking water, thus preventing potential health hazards. Immobilized AgNPs showed no cytotoxic effects on the human hepatocarcinoma cell line (HepG2). Moreover, treating cells with the antibacterial substrate for 24 hours did not lead to significant generation of reactive oxygen species (ROS). The good biocompatibility and bactericidal efficacy would thus make it feasible to utilize this immobilization strategy for preparing new-generation antibacterial coatings.Silver-based hybrid nanomaterials are gaining interest as potential alternatives for conventional antimicrobial agents. Herein, we present a simple, facile and eco-friendly approach for the deposition of silver nanoparticles (AgNPs) on ZnO nanorods, which act as a

  14. Silk fibroin immobilization on poly(ethylene terephthalate) films: Comparison of two surface modification methods and their effect on mesenchymal stem cells culture

    International Nuclear Information System (INIS)

    Silk fibroin (SF) has played a curial role for the surface modification of conventional materials to improve the biocompatibility, and SF modified poly(ethylene terephthalate) (PET) materials have potential applications on tissue engineering such as artificial ligament, artificial vessel, artificial heart valve sewing cuffs dacron and surgical mesh engineering. In this work, SF was immobilized onto PET film via two different methods: 1) plasma pretreatment followed by SF dip coating (PET-SF) and 2) plasma-induce acrylic acid graft polymerization and subsequent covalent immobilization of SF on PET film (PET-PAA-SF). It could be found that plasma treatment provided higher surface roughness which was suitable for further SF dip coating, while grafted poly(acrylic acid) (PAA) promised the covalent bonding between SF and PAA. ATR-FTIR adsorption band at 3284 cm−1, 1623 cm−1 and 1520 cm−1 suggested the successful introduction of SF onto PET surface, while the amount of immobilized SF of PET-SF was higher than PET-PAA-SF according to XPS investigation (0.29 vs 0.23 for N/C ratio). Surface modified PET film was used as substrate for mesenchymal stem cells (MSCs) culture, the cells on PET-SF surface exhibited optimum density compared to PET-PAA-SF according to CCK-8 assays, which indicated that plasma pretreatment followed by SF dip coating was a simple and effective way to prepare biocompatible PET surface. Highlights: ► Silk fibroins were immobilized onto PET films with or without the linker of PAA. ► Various techniques were performed to characterize the modified surfaces ► Plasma treatment followed by SF dip coating introduced more SF onto PET films. ► Compare to PET-PAA-SF, PET-SF has better biocompatibility base on MSCs culture

  15. Complete biodegradation of chlorpyrifos by engineered Pseudomonas putida cells expressing surface-immobilized laccases.

    Science.gov (United States)

    Liu, Jin; Tan, Luming; Wang, Jing; Wang, Zhiyong; Ni, Hong; Li, Lin

    2016-08-01

    The long-term abuse use of chlorpyrifos-like pesticides in agriculture and horticulture has resulted in significant soil or water contamination and a worldwide ecosystem threat. In this study, the ability of a solvent-tolerant bacterium, Pseudomonas putida MB285, with surface-displayed bacterial laccase, to biodegrade chlorpyrifos was investigated. The results of compositional analyses of the degraded products demonstrate that the engineered MB285 was capable of completely eliminating chlorpyrifos via direct biodegradation, as determined by high-performance liquid chromatography and gas chromatography-mass spectrometry assays. Two intermediate metabolites, namely 3,5,6-trichloro-2-pyridinol (TCP) and diethyl phosphate, were temporarily detectable, verifying the joint and stepwise degradation of chlorpyrifos by surface laccases and certain cellular enzymes, whereas the purified free laccase incompletely degraded chlorpyrifos into TCP. The degradation reaction can be conducted over a wide range of pH values (2-7) and temperatures (5-55 °C) without the need for Cu(2+). Bioassays using Caenorhabditis elegans as an indicator organism demonstrated that the medium was completely detoxified of chlorpyrifos by degradation. Moreover, the engineered cells exhibited a high capacity of repeated degradation and good performance in continuous degradation cycles, as well as a high capacity to degrade real effluents containing chlorpyrifos. Therefore, the developed system exhibited a high degradation capacity and performance and constitutes an improved approach to address chlorpyrifos contamination in chlorpyrifos-remediation practice. PMID:27231878

  16. Fabrication of biofuel cell containing enzyme catalyst immobilized by layer-by-layer method

    Science.gov (United States)

    Hyun, Kyu Hwan; Han, Sang Won; Koh, Won-Gun; Kwon, Yongchai

    2015-07-01

    Enzymatic biofuel cell (EBC) employing a layer-by-layer (LbL) structure consisting of multiple layers of glucose oxidase (GOx) and poly(ethyleneimine) (PEI) at carbon nanotube (CNT) ([GOx/PEI]n/CNT) is fabricated. The [GOx/PEI]n/CNT serves as anode catalyst for promoting glucose reaction, while Pt is employed as cathode catalyst. To evaluate effect of [GOx/PEI]n/CNT on EBC performance and stability, several characterizations are conducted. The optimal GOx/PEI layer is determined electrochemically, and it turns out that [GOx/PEI]2/CNT is the best. Electron transfer rate constant of the optimal layer is 11.3 s-1, its glucose sensitivity is 83 μAmM-1cm-2, and maximum power density of EBC adopting [GOx/PEI]2/CNT is 1.34 mWcm-2. The values are superior to those of other reference structures, indicating that the [GOx/PEI]2/CNT can produce excellent reactivity, followed by improved EBC performance. In terms of redox reaction mechanism of flavin adenine dinucleotide (FAD) within [GOx/PEI]2/CNT, glucose does not affect the redox reaction of FAD, while oxygen serves as mediator in transferring electrons and protons produced by glucose oxidation into those for reduction reaction of FAD. It is also found that the [GOx/PEI]2/CNT is confined by surface reaction and the reaction is quasi-reversible. Regarding long-term stability, [GOx/PEI]2/CNT maintains ∼83% of initial activity even after two weeks.

  17. Use of Saccharum spontaneum (wild sugarcane) as biomaterial for cell immobilization and modulated ethanol production by thermotolerant Saccharomyces cerevisiae VS3.

    Science.gov (United States)

    Chandel, Anuj K; Narasu, M Lakshmi; Chandrasekhar, G; Manikyam, A; Rao, L Venkateswar

    2009-04-01

    Saccharum spontaneum is a wasteland weed consists of 45.10+/-0.35% cellulose and 22.75+/-0.28% of hemicellulose on dry solid (DS) basis. Aqueous ammonia delignified S. spontaneum yielded total reducing sugars, 53.91+/-0.44 g/L (539.10+/-0.55 mg/g of substrate) with a hydrolytic efficiency of 77.85+/-0.45%. The enzymes required for hydrolysis were prepared from culture supernatants of Aspergillus oryzae MTCC 1846. A maximum of 0.85+/-0.07 IU/mL of filter paperase (FPase), 1.25+/-0.04 IU/mL of carboxy methyl cellulase (CMCase) and 55.56+/-0.52 IU/mL of xylanase activity was obtained after 7 days of incubation at 28+/-0.5 degrees C using delignified S. spontaneum as carbon source under submerged fermentation conditions. Enzymatic hydrolysate of S. spontaneum was then tested for ethanol production under batch and repeated batch production system using "in-situ" entrapped Saccharomyces cerevisiae VS3 cells in S. spontaneum stalks (1 cm x 1 cm) size. Immobilization was confirmed by the scanning electron microscopy (SEM). Batch fermentation of VS3 free cells and immobilized cells showed ethanol production, 19.45+/-0.55 g/L (yield, 0.410+/-0.010 g/g) and 21.66+/-0.62 g/L (yield, 0.434+/-0.021 g/g), respectively. Immobilized VS3 cells showed maximum ethanol production (22.85+/-0.44 g/L, yield, 0.45+/-0.04 g/g) up to 8th cycle during repeated batch fermentation followed by a gradual reduction in subsequent cycles of fermentation. PMID:19114303

  18. Physiological and Morphological Modifications in Immobilized Gibberella fujikuroi Mycelia

    OpenAIRE

    Saucedo, José Edmundo Nava; Barbotin, Jean-Noël; Thomas, Daniel

    1989-01-01

    Constraints created by immobilization conditions modified the physiological behavior and morphological characteristics of Gibberella fujikuroi mycelia in comparison with their development in free-cell conditions. G. fujikuroi mycelia were immobilized in different support matrices (polyurethane, carrageenan, and alginate) and showed a variety of reactions in response to the different microenvironmental factors encountered during and after immobilization. The best support with respect to gibber...

  19. Matrix-immobilized BMP-2 on microcontact printed fibronectin as in vitro tool to study BMP-mediated signaling and cell migration

    Directory of Open Access Journals (Sweden)

    Kristin eHauff

    2015-05-01

    Full Text Available During development, bone morphogenetic proteins (BMPs exert important functions in several tissues by regulating signaling for cell differentiation and migration. In vivo the extracellular matrix (ECM not only provides a support for adherent cells, but also presents a reservoir of growth factors (GFs. Several constituents of the ECM provide adhesive cues, which serve as binding sites for cell transmembrane receptors, such as integrins, which convey adhesion-mediated signaling to the intracellular compartment. Integrins do not function alone but rather crosstalk and cooperate with other receptors, such as GF receptors, in regulating cell responses to extracellular signals. To this, we present here the immobilization of BMP-2 onto cellular fibronectin (cFN, a key protein of the ECM, to investigate their impact on GF-mediated signaling and migration.Following biotinylation, BMP-2 was linked to biotinylated cFN using NeutrAvidin (NA as cross-linker. Characterization with QCM-D and ELISA confirmed the efficient immobilization of BMP-2 on cFN over a period of 24 h.To validate the bioactivity of matrix-immobilized BMP-2 (iBMP-2 we investigated short- and long-term responses of C2C12 myoblasts in comparison to soluble BMP-2 (sBMP-2 or in absence of GFs. Similarly to sBMP-2, iBMP-2 triggered Smad 1/5 phosphorylation and translocation into the nucleus corresponding to the activation of BMP-mediated Smad-dependent pathway. Additionally, successful suppression of myotube formation was observed after six days.We next implemented this approach to fabricate cFN micro patterned stripes by soft lithography. These stripes only allowed cell-surface interaction on the pattern due to passivation of the surface in between, thus serving as platform for studies on directed cell migration. During a 10 h-period, cells showed an increased migratory activity upon BMP-2 exposure.Thus, this versatile tool retains the GF's bioactivity and allows the presentation of ECM

  20. Direct photo-patterning of hyaluronic acid baits onto a fouling-release perfluoropolyether surface for selective cancer cell capture and immobilization.

    Science.gov (United States)

    Credi, Caterina; De Marco, Carmela; Molena, Elena; Nava, Michele M; Raimondi, Manuela T; Levi, Marinella; Turri, Stefano

    2016-05-01

    A simple photolithographic process for directly patterning glycidyl methacrylate modified hyaluronic acid features onto UV curable perfluoropolyether-based surfaces is presented. Due to the versatility of the developed method, HA spotted areas with different geometrical features could be rapidly and inexpensively designed. In addition, the excellent antifouling and fouling-release properties of the substrates enabled direct HA baits photo-grafting onto PFPEs without further surface passivation or chemical modification to avoid not specific adsorption. The aim of the study was to locally switch the surface properties of the PFPEs from cells and protein repulsive to adherent. Particularly, we exploited HA well-known preferential interactions with CD44 transmembrane receptors to selectively immobilize cancer cells. Living cell arrays offer a higher-resolution visualization of HA-CD44 interactions and may provide a deep insight into understanding molecular mechanisms needed to develop selective therapies and diagnosis against tumor growth. PMID:26952441

  1. RAD18 and associated proteins are immobilized in nuclear foci in human cells entering S-phase with ultraviolet light-induced damage

    International Nuclear Information System (INIS)

    Proteins required for translesion DNA synthesis localize in nuclear foci of cells with replication-blocking lesions. The dynamics of this process were examined in human cells with fluorescence-based biophysical techniques. Photobleaching recovery and raster image correlation spectroscopy experiments indicated that involvement in the nuclear foci reduced the movement of RAD18 from diffusion-controlled to virtual immobility. Examination of the mobility of REV1 indicated that it is similarly immobilized when it is observed in nuclear foci. Reducing the level of RAD18 greatly reduced the focal accumulation of REV1 and reduced UV mutagenesis to background frequencies. Fluorescence lifetime measurements indicated that RAD18 and RAD6A or polη only transferred resonance energy when these proteins colocalized in damage-induced nuclear foci, indicating a close physical association only within such foci. Our data support a model in which RAD18 within damage-induced nuclear foci is immobilized and is required for recruitment of Y-family DNA polymerases and subsequent mutagenesis. In the absence of damage these proteins are not physically associated within the nucleoplasm

  2. 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

  3. 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

  4. Production of Ethanol from Beet Molasses by Ca-Alginate Immobilized Yeast Cells in a Packed-Bed Bioreactor

    OpenAIRE

    GÖKSUNGUR, Yekta; ZORLU, Neşe

    2001-01-01

    The continuous production of ethanol from beet molasses by Ca-alginate immobilized Saccharomyces cerevisiae in a packed-bed bioreactor was investigated. The temperature was maintained at 30°C and the dilution rate was 0.22 h-1. Maximum ethanol (4.62%), theoretical yield (82.9%) and volumetric productivity (10.16 gl-1h-1) were obtained from the beet molasses medium containing 10.90% total sugar with 2.0-2.4 mm diameter beads prepared from 2% (w/v) sodium alginate solution. At higher substrate ...

  5. A High-Throughput Oxidative Stress Biosensor Based on Escherichia coli roGFP2 Cells Immobilized in a k-Carrageenan Matrix

    Science.gov (United States)

    Ooi, Lia; Heng, Lee Yook; Mori, Izumi C.

    2015-01-01

    Biosensors fabricated with whole-cell bacteria appear to be suitable for detecting bioavailability and toxicity effects of the chemical(s) of concern, but they are usually reported to have drawbacks like long response times (ranging from hours to days), narrow dynamic range and instability during long term storage. Our aim is to fabricate a sensitive whole-cell oxidative stress biosensor which has improved properties that address the mentioned weaknesses. In this paper, we report a novel high-throughput whole-cell biosensor fabricated by immobilizing roGFP2 expressing Escherichia coli cells in a k-carrageenan matrix, for the detection of oxidative stress challenged by metalloid compounds. The E. coli roGFP2 oxidative stress biosensor shows high sensitivity towards arsenite and selenite, with wide linear range and low detection limit (arsenite: 1.0 × 10−3–1.0 × 101 mg·L−1, LOD: 2.0 × 10−4 mg·L−1; selenite: 1.0 × 10−5–1.0 × 102 mg·L−1, LOD: 5.8 × 10−6 mg·L−1), short response times (0–9 min), high stability and reproducibility. This research is expected to provide a new direction in performing high-throughput environmental toxicity screening with living bacterial cells which is capable of measuring the bioavailability and toxicity of environmental stressors in a friction of a second. PMID:25621608

  6. Immobilization of biomacromolecules on poly-L-lactide surface via a layer-by-layer method for the improving of its cytocompatibility to bone marrow stromal cells

    Institute of Scientific and Technical Information of China (English)

    L(U) Delong; MENG Sheng; ZHONG Wei; DU Qiangguo; GONG Li; LIU Jinfen; Dusan Bakos

    2005-01-01

    Hyaluronic acid (HA) and chitosan (CS) were immobilized on the surface of poly-L-lactide (PLLA) by the following procedure: Firstly, PLLA was aminolyzed with 1, 6-hexanediamine, and part of the PLLA surface ester groups were converted to free amino groups. Then negatively charged hyaluronic acid and positively charged chitosan were deposited onto the surface of aminolyzed PLLA film in a layer-by-layer assembly manner. The effect of the layer-by- layer deposition was evaluated by ATR-FTIR spectroscopy, Raman spectroscopy and static contact angle measurements. The cytocompatibility of PLLA sample to bone marrow stromal cells (BMSCs) was improved after modification with chitosan and HA. The cell attachment, activity, and proliferation on CS/HA modified PLLA films were enhanced comparing with the control. The cells cultured on the modified PLLA samples excreted abundant cytoplasm and can differentiate to vascular smooth muscle (SM)-like (SM-like) cells. A macroporous three-dimensional PLLA scaffold was prepared by integrating both the technique of freeze-drying and particle leaching. Layer-by-layer modification by HA/CS and cell culture was also applied on this scaffold. The scaffold cultured with BMSCs for 2 weeks has been tested successfully in vivo as a patch for repairing the artificial incision on canine pulmonary artery.

  7. Enzyme immobilization: an update

    OpenAIRE

    Homaei, Ahmad Abolpour; Sariri, Reyhaneh; Vianello, Fabio; Stevanato, Roberto

    2013-01-01

    Compared to free enzymes in solution, immobilized enzymes are more robust and more resistant to environmental changes. More importantly, the heterogeneity of the immo-bilized enzyme systems allows an easy recovery of both enzymes and products, multiple re-use of enzymes, continuous operation of enzymatic processes, rapid termination of reactions, and greater variety of bioreactor designs. This paper is a review of the recent literatures on enzyme immobilization by various techniques, the need...

  8. 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...

  9. 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.

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

    International Nuclear Information System (INIS)

    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 Mg2+ and Ca2+ 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 while

  11. 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

  12. Immobilized waste leaching

    International Nuclear Information System (INIS)

    The main mechanism by which the immobilized radioactive materials can return to biosphere is the leaching due to the intrusion of water into the repositories. Some mathematical models and experiments utilized to evaluate the leaching rates in different immobilization matrices are described. (author)

  13. Modulation of Selectin-Mediated Adhesion of Flowing Lymphoma and Bone Marrow Cells by Immobilized SDF-1

    Directory of Open Access Journals (Sweden)

    Elizabeth A. Hedges

    2014-08-01

    Full Text Available The α-chemokine, stromal-derived factor-1 (SDF-1, has been linked to the homing of circulating tumor cells to bone. SDF-1 is expressed by bone microvascular cells and osteoblasts and normally functions to attract blood-borne hematopoietic stem and progenitor cells to marrow. It has been shown that treatment of cancer cells with soluble SDF-1 results in a more aggressive phenotype; however, the relevance of the administration of the soluble protein is unclear. As such, a flow device was functionalized with P-selectin and SDF-1 to mimic the bone marrow microvasculature and the initial steps of cell adhesion. The introduction of SDF-1 onto the adhesive surface was found to significantly enhance the adhesion of lymphoma cells, as well as low-density bone marrow cells (LDBMC, both in terms of the number of adherent cells and the strength of cell adhesion. Thus, SDF-1 has a synergistic effect with P-selectin on cancer cell adhesion and may be sufficient to promote preferential metastasis to bone.

  14. A bioanode based on MWCNT/protein-assisted co-immobilization of glucose oxidase and 2,5-dihydroxybenzaldehyde for glucose fuel cells.

    Science.gov (United States)

    Yu, Chung-Mu; Yen, Miao-Ju; Chen, Lin-Chi

    2010-07-15

    This paper describes an easy-to-prepare, robust bioanode constructed on a polyester-supported screen-printed carbon paste electrode (SPCE) for glucose biofuel cells. To prepare the bioanode, carboxylated multi-walled carbon nanotubes (MWCNTs) were drop-coated on the SPCE first, and then a crosslinked matrix composed of glucose oxidase (GOx), 2,5-dihydroxybenzaldehyde (DHB), bovine serum albumin (BSA) and glutaraldehyde was coated atop the MWCNTs. It was found that the MWCNTs assisted the immobilization of the crosslinked matrix, enhanced the electron-shuttling process, and showed electrocatalytic effect to gluconic acid, which allowed squeeze more electrons out of a glucose molecule. Inside the matrix, DHB mediators could couple to GOx and BSA via the Schiff base reaction, and GOx and BSA could crosslink to each other with glutaraldehyde. From cyclic voltammetry, it was estimated that 3.63 nmol cm(-2) of DHB was anchored on the bioanode, and no mediator leaching was observed. The bioanode also attained reproducible flow-injection analysis (FIA) signals for glucose sensing (RSD=4.99%) and retained 84% of the initial response after keeping in a buffer at 4 degrees C for a week. In addition, the bioanode obeyed the Michaelis-Menten kinetics. Finally, we demonstrated that a glucose biofuel cell assembled with an optimal bioanode and a laccase/ABTS cathode generated an electric power of 45 microW cm(-2) from 1M glucose at 37 degrees C. PMID:20472420

  15. Plutonium Disposition by Immobilization

    International Nuclear Information System (INIS)

    The ultimate goal of the Department of Energy (DOE) Immobilization Project is to develop, construct, and operate facilities that will immobilize between 17 to 50 tonnes (MT) of U.S. surplus weapons-usable plutonium materials in waste forms that meet the ''spent fuel'' standard and are acceptable for disposal in a geologic repository. Using the ceramic can-in-canister technology selected for immobilization, surplus plutonium materials will be chemically combined into ceramic forms which will be encapsulated within large canisters of high level waste (HLW) glass. Deployment of the immobilization capability should occur by 2008 and be completed within 10 years. In support of this goal, the DOE Office of Fissile Materials Disposition (MD) is conducting development and testing (D and T) activities at four DOE laboratories under the technical leadership of Lawrence Livermore National Laboratory (LLNL). The Savannah River Site has been selected as the site for the planned Plutonium Immobilization Plant (PIP). The D and T effort, now in its third year, will establish the technical bases for the design, construction, and operation of the U. S. capability to immobilize surplus plutonium in a suitable and cost-effective manner. Based on the D and T effort and on the development of a conceptual design of the PIP, automation is expected to play a key role in the design and operation of the Immobilization Plant. Automation and remote handling are needed to achieve required dose reduction and to enhance operational efficiency

  16. The Application of Dielectric Spectroscopy and Biocalorimetry for the Monitoring of Biomass in Immobilized Mammalian Cell Cultures

    Directory of Open Access Journals (Sweden)

    Harriet E. Cole

    2015-05-01

    Full Text Available The purpose of this study was to introduce dielectric spectroscopy and biocalorimetry as monitoring methods to follow immobilised Chinese Hamster Ovary (CHO cell culture development. The theory behind both monitoring techniques is explained and perfusion cultures are performed in a Reaction Calorimeter (eRC1 from Mettler Toledo as an application example. The findings of this work show that dielectric spectroscopy gives highly reliable information upon the viable cell density throughout the entire culture. On the other hand, the RC1 could only provide accurate data from day 5, when the cell density exceeded 4 × 106 vcells∙mL−1 (viable cell per mL working volume (WV. The method validation showed the limit of detection (LOD for 1.4 L cultures to be 8.86 × 106 vcells∙mL−1, a viable cell density commonly achieved in fed-batch and the early stages of a perfusion culture. This work suggests that biocalorimetry should be possible to implement at industrial scale to monitor CHO cell cultures.

  17. Radiation technology for immobilization of bioactive materials

    International Nuclear Information System (INIS)

    Within the framework of the Agency's coordinated research programme on ''Application of Radiation Technology in Immobilization of Bioactive Materials'', the third and final research coordination meeting was held at Beijing University, Beijing, People's Republic of China, 15-18 June 1987. The present publication compiles all presentations made at the meeting. Fundamental processes for the immobilization of enzymes, antibodies, cells and drugs were developed and established using gamma radiation, electron beams and plasma discharge. Applications of various biofunctional components, immobilized by radiation techniques in different processes, were studied. A range of backbone polymers has been examined together with various monomers. Coupling procedures have been developed which are relevant to our particular requirements. Enzymes of various types and characteristics have been immobilized with considerable efficiency. The immobilized biocatalysts have been shown to possess significant activity and retention of activity on storage. There appears to be a high degree of specificity associated with the properties of the immobilised biocatalysts, their activity and the ease of their preparation. Novel additives which lower the total radiation dose in grafting have been discovered and their value in immobilization processes assessed. Potential applications include: medical (diagnostic, therapeutic), and industrial processes (fermentation, bioseparation, etc.). Refs, figs and tabs

  18. Immobilization induced hypercalcemia

    Science.gov (United States)

    Cano-Torres, Edgar Alonso; González-Cantú, Arnulfo; Hinojosa-Garza, Gabriela; Castilleja-Leal, Fernando

    2016-01-01

    Summary Immobilization hypercalcemia is an uncommon diagnosis associated with increased bone remodeling disorders and conditions associated with limited movement such as medullar lesions or vascular events. Diagnosis requires an extensive evaluation to rule out other causes of hypercalcemia. This is a report of a woman with prolonged immobilization who presented with severe hypercalcemia. This case contributes to identification of severe hypercalcemia as a result of immobility and the description of bone metabolism during this state. PMID:27252745

  19. Dynamic Presentation of Immobilized Ligands Regulated through Biomolecular Recognition

    OpenAIRE

    Liu, Bo; Liu, Yang; Riesberg, Jeremiah J.; Shen, Wei

    2010-01-01

    To mimic the dynamic regulation of signaling ligands immobilized on extracellular matrices or on the surfaces of neighboring cells for guidance of cell behavior and fate selection, we have harnessed biomolecular recognition in combination with polymer engineering to create dynamic surfaces on which the accessibility of immobilized ligands to cell surface receptors can be reversibly interconverted under physiological conditions. The cell-adhesive RGD peptide is chosen as a model ligand. RGD is...

  20. Hyaluronic Acid Immobilized Polyacrylamide Nanoparticle Sensors for CD44 Receptor Targeting and pH Measurement in Cells

    DEFF Research Database (Denmark)

    Sun, Honghao; Benjaminsen, Rikke Vicki; Almdal, Kristoffer;

    2012-01-01

    the CD44 receptor, which is overexpressed on the surface of a broad variety of cancer cells, we have synthesized an NP pH sensor system that targets CD44. We used a polyacrylamide nanoparticle matrix bearing hyaluronic acid (HA) on the surface as a CD44 targeting ligand. The HA-coated NPs were...

  1. Escherichia coli NemA is an efficient chromate reductase that can be biologically immobilized to provide a cell free system for remediation of hexavalent chromium.

    Directory of Open Access Journals (Sweden)

    Katherine J Robins

    Full Text Available Hexavalent chromium is a serious and widespread environmental pollutant. Although many bacteria have been identified that can transform highly water-soluble and toxic Cr(VI to insoluble and relatively non-toxic Cr(III, bacterial bioremediation of Cr(VI pollution is limited by a number of issues, in particular chromium toxicity to the remediating cells. To address this we sought to develop an immobilized enzymatic system for Cr(VI remediation. To identify novel Cr(VI reductase enzymes we first screened cell extracts from an Escherichia coli library of soluble oxidoreductases derived from a range of bacteria, but found that a number of these enzymes can reduce Cr(VI indirectly, via redox intermediates present in the crude extracts. Instead, activity assays for 15 candidate enzymes purified as His6-tagged proteins identified E. coli NemA as a highly efficient Cr(VI reductase (k(cat/K(M= 1.1×10(5 M(-1 s(-1 with NADH as cofactor. Fusion of nemA to the polyhydroxyalkanoate synthase gene phaC from Ralstonia eutropha enabled high-level biosynthesis of functionalized polyhydroxyalkanoate granules displaying stable and active NemA on their surface. When these granules were combined with either Bacillus subtilis glucose dehydrogenase or Candida boidinii formate dehydrogenase as a cofactor regenerating partner, high levels of chromate transformation were observed with only low initial concentrations of expensive NADH cofactor being required, the overall reaction being powered by consumption of the cheap sacrificial substrates glucose or formic acid, respectively. This system therefore offers promise as an economic solution for ex situ Cr(VI remediation.

  2. An automated method for determining the cytoadhesion of Plasmodium falciparum-infected erythrocytes to immobilized cells

    DEFF Research Database (Denmark)

    Hempel, Casper; Boisen, Ida M; Efunshile, Akinwale;

    2015-01-01

    BACKGROUND: Plasmodium falciparum exports antigens to the surface of infected erythrocytes causing cytoadhesion to the host vasculature. This is central in malaria pathogenesis but in vitro studies of cytoadhesion rely mainly on manual counting methods. The current study aimed at developing an...... automated high-throughput method for this purpose utilizing the pseudoperoxidase activity of intra-erythrocytic haemoglobin. METHODS: Chinese hamster ovary (CHO) cells were grown to confluence in chamber slides and microtiter plates. Cytoadhesion of co-cultured P. falciparum, selected for binding to CHO...

  3. Cell surface polypeptide CshA mediates binding of Streptococcus gordonii to other oral bacteria and to immobilized fibronectin.

    OpenAIRE

    McNab, R; Holmes, A.R.; Clarke, J M; Tannock, G W; Jenkinson, H F

    1996-01-01

    Isogenic mutants of Streptococcus gordonii DL1 (Challis) in which the genes encoding high-molecular-mass cell surface polypeptides CshA and/or CshB were inactivated were deficient in binding to four strains of Actinomyces naeslundii and two strains of Streptococcus oralis. Lactose-sensitive interactions of S. gordonii with A. naeslundii ATCC 12104 and PK606 were associated with expression of cshA but not of cshB. Lactose-insensitive interactions of S. gordonii with A. naeslundii T14V and WVU6...

  4. 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.

  5. Immobilization of Trichoderma reesei by radiation polymerization

    International Nuclear Information System (INIS)

    Immobilization of Trichoderma reesei was carried out by radiation polymerization. It was found that the activity of fixed cells increased with increasing surface area of the carrier and was affected by the concentration of monomer tetraethylenglycol dimethacrylate and the shape of the substrate composition and structure of cotton textile fabrics. (author)

  6. Performance of three pilot-scale immobilized-cell biotrickling filters for removal of hydrogen sulfide from a contaminated air steam.

    Science.gov (United States)

    Chen, Yiqing; Fan, Zhidong; Ma, Lixia; Yin, Juan; Luo, Man; Cai, Wangfeng

    2014-11-01

    Hydrogen sulfide (H2S) is a major malodorous compound emitted from wastewater treatment plants. In this study, the performance of three pilot-scale immobilized-cell biotrickling filters (BTFs) spacked with combinations of bamboo charcoal and ceramsite in different ratios was investigated in terms of H2S removal. Extensive tests were performed to determine the removal characteristics, pressure drops, metabolic products, and removal kinetics of the BTFs. The BTFs were operated in continuous mode at low loading rates varying from 0.59 to 5.00 g H2S m(-3) h(-1) with an empty bed retention time (EBRT) of 25 s. The removal efficiency (RE) for each BTF was >99% in the steady-state period, and high standards were met for the exhaust gas. It was found that a multilayer BTF had a slight advantage over a perfectly mixed BTF for the removal of H2S. Furthermore, an impressive amount >97% of the H2S was eliminated by 10% of packing materials near the inlet of the BTF. The modified Michaelis-Menten equation was adopted to describe the characteristics of the BTF, and K s and V m values for the BTF with pure bamboo charcoal packing material were 3.68 ppmv and 4.26 g H2S m(-3) h(-1), respectively. Both bamboo charcoal and ceramsite demonstrated good performance as packing materials in BTFs for the removal of H2S, and the results of this study could serve as a guide for further design and operation of industrial-scale systems. PMID:25313280

  7. Effects of multiple polyaniline layers immobilized on carbon nanotube and glutaraldehyde on performance and stability of biofuel cell

    Science.gov (United States)

    Christwardana, Marcelinus; Kwon, Yongchai

    2015-12-01

    Enzymatic biofuel cell (EBC) employing new catalyst for anode electrode is fabricated. The new catalyst consists of glucose oxidase (GOx), polyaniline (PANI) and carbon nanotube (CNT) that are multiply stacked together and finally the stack layer is surrounded by glutaraldehyde (GA) (GA/[GOx/PANI/CNT]n). To evaluate how the GA/[GOx/PANI/CNT]n layer affects EBC performance and stability, electrochemical characterizations are implemented. Regarding optimization, GA/[GOx/PANI/CNT]3 is determined. For elucidating reaction mechanism between glucose and flavin adenine dinucleotide (FAD) of GA/[GOx/PANI/CNT]3, associated investigations are performed. In the evaluations, drop in reduction current peak of FAD is observed with provisions of glucose and O2, while glucose does not influence FAD reaction without O2, confirming O2 makes mediator role. When the GA/[GOx/PANI/CNT]3 layer is adopted, superior catalytic activity and EBC performance are gained (electron transfer rate constant of 5.1 s-1, glucose sensitivity of 150 ìA mM-1 cm-2, and EBC maximum power density (MPD) of 0.29 mW cm-2). Regarding EBC stability, MPD of EBC adopting GA/[GOx/PANI/CNT]3 maintains up to 93% of their initial value even after four weeks. Although GA is little effective for improving EBC performance, EBC stability is helped by GA due to its adhesion promotion capability with [GOx/PANI/CNT]n layer.

  8. The effects of immobilization on the maturation of the anterior cruciate ligament of the rabbit knee.

    OpenAIRE

    Amiel, D.; Wallace, C. D.; Harwood, F. L.

    1994-01-01

    Immobilization-induced alterations occurred in young anterior cruciate ligament (ACL) samples, including the loss of the rounded appearance of the cells. The mature ACL was minimally altered by immobilization at the light microscopy level. In the immobilized young ACL the fibroblasts became elongated and there was loss of the normal pericellular matrix. The immobilized mature ACL differed from controls primarily in the intracellular composition, as there was significantly more rough endoplasm...

  9. The 13C/12C fractionation by microbial cells immobilized on a solid-phase carrier during the growth on glucose

    Science.gov (United States)

    Zyakun, Anatoly; Kochetkov, Vladimir

    2010-05-01

    Problem. In microbiological ecology, the level of basal СО2 respiration and the potential of microbial activity defined as substrate-induced respiration (SIR) are used as criteria of the metabolic state of soil microbiota. The peculiar feature of glucose metabolism in soil is its utilization by microbial cells immobilized on soil particles as a solid-phase carrier. The efficiency of substrate utilization and СО2 production in such cases depend on the rate of microorganisms' growth and colonization of the solid-phase carrier surface, where the substrate is located. The products of microbial metabolism are supposed to inherit the substrate isotope composition correct to the isotopic effects accompanying substrate utilization and metabolic transformations. However, all experiments in carbon isotope fractionation during microbial utilization of glucose as a substrate have been carried out with microorganisms growing in liquid media. Objective: Study of the kinetics of glucose utilization as a test substrate during the growth of soil microorganisms immobilized on a solid-phase carrier and ascertainment of peculiarities of the formation of carbon isotope composition of produced metabolic СО2. The objects of research were Pseudomonas aureofaciens BS1393(pBS216) (culture A) and Rhodococcus sp. 3-30 (culture B) as representatives of pseudomonades and rhodococci, which occur in the soils of different genesis and are of defining value in development and implementation of biotechnological schemes for degradation of toxic organic pollutants in the environment. Results and discussion. The cultures under study had different rates of growth on glucose. Specific rates of СО2 production during the growth of cultures A and B on glucose were 0.34 (± 0.05) and 0.078 (± 0.01) μg С-СО2 h-1, respectively. The lag periods of culture (A and B) growth were about 4.3 and 26 h, respectively. Comparison of the lag periods of these representatives of pseudomonades and rhodococci

  10. Effect of cell immobilization on the treatment of olive mill wastewater by a total phenols, acetic acid and formic acid degrading bacterium strain

    Directory of Open Access Journals (Sweden)

    Errami, Mohamed

    2005-06-01

    Full Text Available Olive mill wastewater (OMW is a pure vegetative by-product, containing a high organic and polyphenol content and is resistant to biodegradation. Its disposal lead to major environmental pollution problems in the Mediterranean basin. An aerobic bacterium was isolated from OMW. During three consecutive diluted and supplemented OMW treatment cycles, significant abatement of its phytotoxic substances was observed. In fact, total phenols, acetic and formic acids were reduced between 33 and 64 % when cells of the isolated bacterium were grown free; and between 62 and 78 % when cells of the same isolated bacterium were grown immobilized in a polyurethane sponge. These results suggest that the bacterium culture of the new isolate would decrease the OMW phytotoxicity. Phylogenetic analysis of 16S ribosomal DNA showed that all the related sequences are members of the Enterobacteriaceae family and revealed that the isolated bacterium was characterized as a Klebsiella oxytoca strain.El alpechín (OMW es un residuo puro de la extracción del aceite de oliva, que contiene una elevada carga orgánica y de polifenoles por lo que es resistente a la degradación. Su descarga produce graves problemas de contaminación medioambiental en toda el área mediterránea. Se ha aislado una bacteria anaerobia del OMW, que , durante tres ciclos consecutivos de tratamiento del OMW diluido y suplementado, produjo una disminución significativa de las sustancias fitotóxicas del residuo. De hecho, la concentración en fenoles totales, ácido acético y ácido fórmico se redujeron entre 33 y 64 % cuando las células no estaban inmovilizadas y entre el 62 y 78 % cuando las células bacterianas se inmovilizaron en una esponja de poliuretano. Estos resultados indican que el cultivo de la nueva bacteria aislada puede disminuir la fototoxicidad del alpechín. Análisis filogenético del ribosoma 16S de DNA demostró que todas las secuencias eran miembros de la familia

  11. Monitoring of the Effect of Dimethyl Sulfoxide on the Growth and Viability of Immobilized Plant Cells Using Two-dimensional Fluorescence Spectroscopy

    Czech Academy of Sciences Publication Activity Database

    Vaňková, Radomíra; Kuncová, Gabriela; Podrazký, Ondřej; Gaudinová, Alena; Vaněk, Tomáš

    France : Bioencapsulation Research Group, 2003, s. 1-4. [International Workshop on Bioencapsulation /11./. Illkirch (FR), 25.03.2003-27.03.2003] R&D Projects: GA MŠk OC 840.20 Institutional research plan: CEZ:AV0Z4072921; CEZ:AV0Z5038910 Keywords : fluorescence spectroscopy * immobilization * dimethyl sulfoxide Subject RIV: CE - Biochemistry

  12. Down-regulation of triose phosphate isomerase in Vineristine-resistant gastric cancer SGC7901 cell line identified by immobilized pH gradient two-dimensional gel electrophoresis and mierosequencing

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Objective:To exkplore new multidrug-resistance-related proteins in gastric SC7901 cells and clarify their mechanisms.Methods:Two-dimensional(2-D) polyacrylamide gel electrophoresis with immobilized pH gradients(IPG) was applied to compare the differential expression of multidrug-resistance-related proteins in gastric cancer SGC7901 cells and Vineristine-resistant SGC7901 cells (SGC7901/VCR) induced by vincristine sulfate.The 2-D gels were silver-stained.Then,preparative 2-D PAGE was performed.The differential proteins of PVDF membranes were cxcised and identified by N-terminal microsequencing.The mRNA expressions of differential proteins were detected in SGC 7901 cells and SGC7901/VCR cells by RT-PCR.Results:Approximatedly 680 protein sports were resolved on each 2-D gel by silver staining.Most protein spots showed no difference in composition,shape or density.25 proteins differed in abundance (6 higher in SGC7901/VCR cells;19 higher in 7901 cells);5 proteins were unique to one kind of cell or the othe(3 in SGC7901/VRC cells,2 in 7901 cells).One drug-resistance-related protein,which was down-regulated in SGC7901/VCR cells,was identified as trisephosphate isomerase(TPI),a glycolytic pathway enzyme.Conclusions:the results suggest that these differential proteins including TPI may be related to the Vincristine-resistant mechanism in human gastric cancer SGC7901/VCR cell line.

  13. Enzyme immobilization by means of ultrafiltration techniques.

    Science.gov (United States)

    Scardi, V; Cantarella, M; Gianfreda, L; Palescandolo, R; Alfani, F; Greco, G

    1980-01-01

    Unstirred, plane membrane, ultrafiltration cells have been used as enzymatic reactor units. Because of the concentration polarization phenomena which take place in the system, at steady-state the enzyme is confined (dynamically immobilized) within an extremely narrow region upstream the ultrafiltration membrane. Correspondingly its concentration attains fairly high values. Kinetic studies have been therefore performed under quite unusual experimental conditions in order to better approximate local enzyme concentration levels in immobilized enzyme systems. Studies have been also carried out on the kinetics of enzyme deactivation in the continuous presence of substrate and reaction products. Once the enzyme concentration profile is completely developed, further injection into the system of suitable amounts of an inert proteic macromolecule (albumin polymers) gives rise to the formation of a gel layer onto the ultrafiltration membrane within which the enzyme is entrapped (statically immobilized). The effect of this immobilization technique has been studied as far as the kinetics of the main reaction, the substrate mass transfer resistances and the enzyme stability are concerned. The rejective properties of such gel layers towards enzymatic molecules have been exploited in producing multilayer, multi-enzymatic reactors. PMID:7417597

  14. Removal of nitrate using Paracoccus sp. YF1 immobilized on bamboo carbon

    International Nuclear Information System (INIS)

    Highlights: ► Paracoccus sp. immobilized on bamboo carbon used for the denitrification. ►The rate of denitrification increased using the immobilized cells. ► 99.8% denitrification was maintained after 10-cycle reuse. ► Demonstrating an excellent reusability and a potential technique. - Abstract: Paracoccus sp. strain YF1 immobilized on bamboo carbon was developed for the denitrification. The results show that denitrification was significantly improved using immobilized cells compared to that of free cells, where denitrification time decreased from 24 h (free cells) to 15 h (immobilized cells). The efficiency of denitrification increased from 4.57 mg/(L h) (free cells) to 6.82 mg/(L h) (immobilized cells). Kinetics studies suggest that denitrification by immobilized YF1 cells fitted well to the zero-order model. Scanning electron microscopy (SEM) demonstrated that firstly, the bacteria became stable on the inside and exterior of the bamboo carbon particles and secondly, they formed biofilm after adhesion. Various factors and their influences on biological denitrification were investigated, namely temperature, pH, initial nitrate concentrations and carbon sources. The immobilized cells exhibited more nitrate removal at various conditions compared to free cells since bamboo carbon as a carrier protects cells against changes in environmental conditions. Denitrification using the YF1 immobilized in bamboo carbon was also maintained 99.8% after the tenth cycle reuse, thus demonstrating excellent reusability. Finally, wastewater was treated using the immobilized cells and the outcome was that nitrogen was completely removed by bamboo-immobilized YF1.

  15. Enhanced xylitol production using immobilized Candida tropicalis with non-detoxified corn cob hemicellulosic hydrolysate

    OpenAIRE

    Yewale, Tatyaso; Panchwagh, Shruti; Rajagopalan, Srinivasan; Dhamole, Pradip B.; Jain, Rishi

    2016-01-01

    This study reports an industrially applicable non-sterile xylitol fermentation process to produce xylitol from a low-cost feedstock like corn cob hydrolysate as pentose source without any detoxification. Different immobilization matrices/mediums (alginate, polyvinyl alcohol, agarose gel, polyacrylamide, gelatin, and κ-carrageenan) were studied to immobilize Candida tropicalis NCIM 3123 cells for xylitol production. Amongst this calcium alginate, immobilized cells produced maximum amount of xy...

  16. Immobilized yeast in bioreactor for alcohol fermentation

    International Nuclear Information System (INIS)

    Mutant of Saccharomyces cerevisiae was developed using a Co-60 source. Cells were immobilized onto sterile, channeled alumina beads and packed into bioreactor column under controlled temperature. Feedstocks containing substrate and nutrients were fed into the bioreactor at specific rates. Beads with greatest porosity and surface area produced the most ethanol. Factors affecting ethanol productivity included: temperature, pH, flow rate, nutrients and substrate in the feedstock

  17. Enhanced Uranium Immobilization and Reduction by Geobacter sulfurreducens Biofilms

    OpenAIRE

    Cologgi, Dena L.; Speers, Allison M.; Bullard, Blair A; Kelly, Shelly D.; Reguera, Gemma

    2014-01-01

    Biofilms formed by dissimilatory metal reducers are of interest to develop permeable biobarriers for the immobilization of soluble contaminants such as uranium. Here we show that biofilms of the model uranium-reducing bacterium Geobacter sulfurreducens immobilized substantially more U(VI) than planktonic cells and did so for longer periods of time, reductively precipitating it to a mononuclear U(IV) phase involving carbon ligands. The biofilms also tolerated high and otherwise toxic concentra...

  18. Kinetics of Phenol Biodegradation by an Immobilized Methanogenic Consortium †

    OpenAIRE

    Dwyer, Daryl F.; Krumme, Mary Lou; Boyd, Stephen A.; Tiedje, James M

    1986-01-01

    A phenol-degrading methanogenic enrichment was successfully immobilized in agar as shown by the stoichiometric conversion of phenol to CH4 and CO2. The enrichment contained members of three physiological groups necessary for the syntrophic mineralization of phenol: a phenol-oxidizing bacterium, a Methanothrix-like bacterium, and an H2-utilizing methanogen. The immobilization technique resulted in the cells being embedded in a long, thin agar strand (1 mm in diameter by 2 to 50 cm in length) t...

  19. 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.

  20. Selected transuranic waste immobilization systems

    International Nuclear Information System (INIS)

    Waste contaminated with transuranic (TRU) elements may require immobilization prior to final disposal. Pacific Northwest Laboratory has conducted research and development to identify and characterize the wastes; to evaluate the possible immobilization requirements and treatment alternatives; and to develop immobilization process technologies. This paper describes systems that are anticipated to be capable of immobilizing a selected TRU waste stream consisting of a blend of process sludge and incinerator ash. The selected waste streams are based on the waste compositions generated at the Rocky Flats Plant, Golden, Colorado. The specific waste forms and processes considered are identified in Table 1. Summary results of leach testing of the immobilized waste forms is provided for comparison. This information along with the processing considerations identify the major advantages and disadvantages of each system. The evaluation of these considerations suggests the implementation for cement or glass system with preference to the cast cement system because of its process simplicity

  1. Bioreporter pseudomonas fluorescens HK44 immobilized in a silica matrix

    Directory of Open Access Journals (Sweden)

    Trogl J.

    2003-01-01

    Full Text Available The bioluminescent bioreporter Pseudomonas fluorescens HK44, the whole cell bacterial biosensor that responds to naphthalene and its metabolites via the production of visible light, was immobilized into a silica matrix by the sol-gel technique. The bioluminescence intensities were measured in the maximum of the bioluminescence band at X = 500 nm. The immobilized cells (>105 cells per g silica matrix produced light after induction by salicylate (cone. > 10 g/l, naphthalene and aminobenzoic acid. The bioluminescence intensities induced by 2,3-dihydroxynaphthalene 3-hydroxybenzoic acid and 4-hydroxybenzoic acid were comparable to a negative control. The cells in the silica layers on glass slides produced light in response to the presence of an inductor at least 8 months after immobilization, and >50 induction cycles. The results showed that these test slides could be used as assays for the multiple determination of water pollution.

  2. Purification for eutrophic lake water with immobilized nitrogen cycle bacteria

    International Nuclear Information System (INIS)

    For purification of eutrophic lake water, immobilized nitrogen cycle bacteria (nitrobacteria-denitrifying) made from radiation copolymerization at low temperatures by means of glass forming monomers, i.e. 2-hydroxyethyl acrylate (HEA) and polyethylene glycol dimethacrylate (14 G) were used. The Sequencing Batch Reactors (SBR) system and cell growths of nitrogen cycle bacteria techniques were carried out in order to treat eutrophic lake water. The results showed that the removal efficiencies for total N(TN), NH4+-N and COD with immobilized nitrogen cycle bacteria were 75%, 91.5% and 75% respectively. The results demonstrated that the optimum temperature of immobilized nitrogen cycle bacteria system was 28 degree C. Immobilized nitrogen cycle bacteria system was more resistance to low temperature (10 degree C). The dissolved oxygen (DO) concentrations have effect on removal efficiencies for TN

  3. Immobilizing U from solution by immobilized sulfate-reducing bacteria of desulfovibrio desulfuricans

    Science.gov (United States)

    Xu, Hulfang; Barton, Larry L.

    2000-07-01

    As determined by transmission electron microscopy, the reduction of uranyl accetate by immobilized cells of Desulfovibrio desulfuricans results in the production of black uraninite nanocrystals precipitated outside the cell. Some nanocrystals are associated with outer membranes of the cell as revealed from cross sections of these metabolically active sulfate-reducing bacteria. The nanocrystals have an average diameter of 5 nm and have anhedral shape. It is proposed that cytochrome in these cells has an important role in the reduction of uranyl through transferring electron from molecular hydrogen or lactic acid to uranyl ions.

  4. Effect of oleic acid on the production of ethanol and fructose from glucose/fructose mixtures in an immobilized cell reactor

    Energy Technology Data Exchange (ETDEWEB)

    Guenette, M.E. [Ottawa Univ., ON (Canada). Dept. of Chemical Engineering]|[IOGEN Corp., Ottawa, ON (Canada); Duvnjak, Z. [Ottawa Univ., ON (Canada). Dept. of Chemical Engineering]|[IOGEN Corp., Ottawa, ON (Canada)

    1995-12-31

    Saccharomyces cerevisiae ATCC 39859 was immobilized onto small cubes of wood to produce ethanol and very enriched fructose syrup from glucose/fructose mixtures through the selective fermentation of glucose. A maximum ethanol productivity of 21.9 g/l.h was attained from a feed containing 9.7% (w/v) glucose and 9.9% (w/v) fructose. An ethanol concentration, glucose conversion and fructose yield of 29.6 g/l, 62% and 99% were obtained, respectively. This resulted in a final fructose/glucose ratio of 2.7. At lower ethanol productivity levels the fructose/glucose ratio increases, as does the ethanol concentration in the effluent. The addition of 30 mg/l oleic acid to the medium increased the ethanol productivity and its concentration by 13% at a dilution rate of 0.74 h{sup -1}. (orig.)

  5. Uptake of plutonium by immobilized bacteria

    International Nuclear Information System (INIS)

    The use of plastic-immobilized bacteria as a system for the concentration of plutonium from aqueous media is investigated. Previous research is reviewed quantifying free cell bacterial concentration of plutonium from solution or suspension. Our research indicates that the species Pseudomonas aeruginosa can be induced to attach firmly to a polymer substrate, while retaining its ability to concentrate plutonium. Melt-blown, filamentous polypropylene is shown to foster cell embedment and uptake capabilities surpassing various other substrates. Oxygen plasma treatment, used to enhance polypropylene wettability, is found to increase the rate of cell embedment significantly. Both embedment and uptake phenomena are found to be dependent upon cell viability. Potential applications for the cell/polymer system are discussed

  6. Poly(Dopamine-Assisted Immobilization of Xu Duan on 3D Printed Poly(Lactic Acid Scaffolds to Up-Regulate Osteogenic and Angiogenic Markers of Bone Marrow Stem Cells

    Directory of Open Access Journals (Sweden)

    Chia-Hung Yeh

    2015-07-01

    Full Text Available Three-dimensional printing is a versatile technique to generate large quantities of a wide variety of shapes and sizes of polymer. The aim of this study is to develop functionalized 3D printed poly(lactic acid (PLA scaffolds and use a mussel-inspired surface coating and Xu Duan (XD immobilization to regulate cell adhesion, proliferation and differentiation of human bone-marrow mesenchymal stem cells (hBMSCs. We prepared PLA scaffolds and coated with polydopamine (PDA. The chemical composition and surface properties of PLA/PDA/XD were characterized by XPS. PLA/PDA/XD controlled hBMSCs’ responses in several ways. Firstly, adhesion and proliferation of hBMSCs cultured on PLA/PDA/XD were significantly enhanced relative to those on PLA. In addition, the focal adhesion kinase (FAK expression of cells was increased and promoted cell attachment depended on the XD content. In osteogenesis assay, the osteogenesis markers of hBMSCs cultured on PLA/PDA/XD were significantly higher than seen in those cultured on a pure PLA/PDA scaffolds. Moreover, hBMSCs cultured on PLA/PDA/XD showed up-regulation of the ang-1 and vWF proteins associated with angiogenic differentiation. Our results demonstrate that the bio-inspired coating synthetic PLA polymer can be used as a simple technique to render the surfaces of synthetic scaffolds active, thus enabling them to direct the specific responses of hBMSCs.

  7. High-level-waste immobilization

    International Nuclear Information System (INIS)

    Analysis of risks, environmental effects, process feasibility, and costs for disposal of immobilized high-level wastes in geologic repositories indicates that the disposal system safety has a low sensitivity to the choice of the waste disposal form

  8. 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.

  9. Covalent co-immobilization of heparin/laminin complex that with different concentration ratio on titanium surface for selectively direction of platelets and vascular cells behavior

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jian; Chen, Yuan; Liu, Tao; Wang, Xue; Liu, Yang; Wang, Yuan; Chen, Junying, E-mail: chenjy@263.net; Huang, Nan

    2014-10-30

    Highlights: • Extracellular matrix inspired surface modification with fibronectin, heparin and VEGF to construct a favorable microenvironment for selectively anticoagulant and promote endothelialization. • Take the advantage of specific intermolecular interaction, the bioactivity of above biomolecules was more efficiently maintained in compared with the common used covalent immobilization method. • Poly-l-lysine was used as a novel interlayer for surface amination, and in comparison, PLL coating was more feasible and the degradation product had no harm to human body. - Abstract: Surface biofunctional modification of coronary artery stent to improve the hemocompatibility and selectively accelerate endothelium regeneration but prevent restenosis have been become a new hotspot. For this, a novel method was developed in this work by co-immobilization of Ln and heparin complex on poly-L-lysine modified Ti surface. Take the advantage of the specific interaction between Ln and heparin, Ln and heparin complexes with different concentration ratios were set up for creating different exposure density of these two types of biomolecules. According to biocompatibility evaluation results, the Hep/Ln complexes modified surface displayed less platelet adhesion and activation. Especially, on L(150)H and L(200)H surface, the AT III binding quantity, APTT value and anti-coagulation property of modified surface were significantly promoted. Furthermore, the adherent density and proliferation activity of ECs and EPCs were positively correlated with Ln concentration. Notably, the proliferation of both ECs and EPCs on L(100)H, L(150)H and L(200)H surface were greatly promoted. Another hand, the proliferation activity of SMCs was significantly inhibited on Hep/Ln modified surfaces, which was considered mainly due to the inhibitory effect of heparin to SMCs. According to the existing results, this study demonstrated that in a certain range of heparin and laminin concentration ratio

  10. Covalent co-immobilization of heparin/laminin complex that with different concentration ratio on titanium surface for selectively direction of platelets and vascular cells behavior

    International Nuclear Information System (INIS)

    Highlights: • Extracellular matrix inspired surface modification with fibronectin, heparin and VEGF to construct a favorable microenvironment for selectively anticoagulant and promote endothelialization. • Take the advantage of specific intermolecular interaction, the bioactivity of above biomolecules was more efficiently maintained in compared with the common used covalent immobilization method. • Poly-l-lysine was used as a novel interlayer for surface amination, and in comparison, PLL coating was more feasible and the degradation product had no harm to human body. - Abstract: Surface biofunctional modification of coronary artery stent to improve the hemocompatibility and selectively accelerate endothelium regeneration but prevent restenosis have been become a new hotspot. For this, a novel method was developed in this work by co-immobilization of Ln and heparin complex on poly-L-lysine modified Ti surface. Take the advantage of the specific interaction between Ln and heparin, Ln and heparin complexes with different concentration ratios were set up for creating different exposure density of these two types of biomolecules. According to biocompatibility evaluation results, the Hep/Ln complexes modified surface displayed less platelet adhesion and activation. Especially, on L(150)H and L(200)H surface, the AT III binding quantity, APTT value and anti-coagulation property of modified surface were significantly promoted. Furthermore, the adherent density and proliferation activity of ECs and EPCs were positively correlated with Ln concentration. Notably, the proliferation of both ECs and EPCs on L(100)H, L(150)H and L(200)H surface were greatly promoted. Another hand, the proliferation activity of SMCs was significantly inhibited on Hep/Ln modified surfaces, which was considered mainly due to the inhibitory effect of heparin to SMCs. According to the existing results, this study demonstrated that in a certain range of heparin and laminin concentration ratio

  11. Bioremediation of Bisphenol A and Benzophenone by Glycosylation with Immobilized Marine Microalga Pavlova sp.

    OpenAIRE

    Kei Shimoda; Hiroki Hamada

    2009-01-01

    Cultured cells of Pavlova sp. glycosylated bisphenol A to its mono-glucoside, 2-(4-β-D-glucopyranosyloxyphenyl)-2- hydroxyphenylpropane (9%). Use of immobilized Pavlova cells in sodium alginate gel improved yield of the product (17%). On the other hand, Pavlova cell cultures converted benzophenone into diphenylmethanol (49%) and diphenylmethyl β-D-glucopyranoside (6%). Incubation of benzophenone with immobilized Pavlova cells gave products in higher yields; the yields of diphenylmethanol and ...

  12. Growth and metabolic activity of conventional and non-conventional yeasts immobilized in foamed alginate.

    Science.gov (United States)

    Kregiel, Dorota; Berlowska, Joanna; Ambroziak, Wojciech

    2013-09-10

    The aim of this research was to study how the cell immobilization technique of forming foamed alginate gels influences the growth, vitality and metabolic activity of different yeasts. Two distinct strains were used, namely conventional yeast (exemplified by Saccharomyces cerevisiae) and a non-conventional strain (exemplified by Debaryomyces occidentalis). The encapsulation of the yeast cells was performed by the traditional process of droplet formation, but from a foamed alginate solution. The activities of two key enzymes, succinate dehydrogenase and pyruvate decarboxylase, together with the ATP content were measured in both the free and immobilized cells. This novel method of yeast cell entrapment had some notable effects. The number of living immobilized cells reached the level of 10(6)-10(7) per single bead, and was stable during the fermentation process. Reductions in both enzyme activity and ATP content were observed in all immobilized yeasts. However, S. cerevisiae showed higher levels of ATP and enzymatic activity than D. occidentalis. Fermentation trials with immobilized repitching cells showed that the tested yeasts adapted to the specific conditions. Nevertheless, the mechanical endurance of the carriers and the internal structure of the gel need to be improved to enable broad applications of alginate gels in industrial fermentation processes, especially with conventional yeasts. This is one of the few papers and patents that describe the technique of cell immobilization in foamed alginate and shows the fermentative capacities and activities of key enzymes in immobilized yeast cells. PMID:23931687

  13. Immobilization of Acetobacter sp. CCTCC M209061 for efficient asymmetric reduction of ketones and biocatalyst recycling

    Directory of Open Access Journals (Sweden)

    Chen Xiao-Hong

    2012-09-01

    Full Text Available Abstract Background The bacterium Acetobacter sp. CCTCC M209061 is a promising whole-cell biocatalyst with exclusive anti-Prelog stereoselectivity for the reduction of prochiral ketones that can be used to make valuable chiral alcohols such as (R-4-(trimethylsilyl-3-butyn-2-ol. Although it has promising catalytic properties, its stability and reusability are relatively poor compared to other biocatalysts. Hence, we explored various materials for immobilizing the active cells, in order to improve the operational stability of biocatalyst. Results It was found that Ca-alginate give the best immobilized biocatalyst, which was then coated with chitosan to further improve its mechanical strength and swelling-resistance properties. Conditions were optimized for formation of reusable immobilized beads which can be used for repeated batch asymmetric reduction of 4′-chloroacetophenone. The optimized immobilized biocatalyst was very promising, with a specific activity of 85% that of the free-cell biocatalyst (34.66 μmol/min/g dw of cells for immobilized catalyst vs 40.54 μmol/min/g for free cells in the asymmetric reduction of 4′-chloroacetophenone. The immobilized cells showed better thermal stability, pH stability, solvent tolerance and storability compared with free cells. After 25 cycles reaction, the immobilized beads still retained >50% catalytic activity, which was 3.5 times higher than degree of retention of activity by free cells reused in a similar way. The cells could be recultured in the beads to regain full activity and perform a further 25 cycles of the reduction reaction. The external mass transfer resistances were negligible as deduced from Damkohler modulus Da η ∅ Conclusions Ca-alginate coated with chitosan is a highly effective material for immobilization of Acetobacter sp. CCTCC M209061 cells for repeated use in the asymmetric reduction of ketones. Only a small cost in terms of the slightly lower catalytic activity compared to

  14. Cultivation characteristics of immobilized Aspergillus oryzae for kojic acid production.

    Science.gov (United States)

    Kwak, M Y; Rhee, J S

    1992-04-15

    Aspergillus oryzae in situ grown from spores entrapped in calcium alginate gel beads was used for the production of kojic acid. The immobilized cells in flask cultures produced kojic acid in a linear proportion while maintaining the stable metabolic activity for a prolonged production period. Kojic acid was accumulated up to a high concentration of 83 g/L, at which the kojic acid began to crystallize, and, thus, the culture had to be replaced with fresh media for the next batch culture. The overall productivities of two consecutive cultivations were higher than that of free mycelial fermentation. However, the production rate of kojic acid by the immobilized cells was suddenly decreased with the appearance of central cavernae inside the immobilized gel beads after 12 days of the third batch cultivation. PMID:18601027

  15. 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.

  16. Cometabolic Degradation of Trichloroethene by Rhodococcus sp. Strain L4 Immobilized on Plant Materials Rich in Essential Oils▿ †

    OpenAIRE

    Suttinun, Oramas; Müller, Rudolf; Luepromchai, Ekawan

    2010-01-01

    The cometabolic degradation of trichloroethene (TCE) by Rhodococcus sp. L4 was limited by the loss of enzyme activity during TCE transformation. This problem was overcome by repeated addition of inducing substrates, such as cumene, limonene, or cumin aldehyde, to the cells. Alternatively, Rhodococcus sp. L4 was immobilized on plant materials which contain those inducers in their essential oils. Cumin seeds were the most suitable immobilizing material, and the immobilized cells tolerated up to...

  17. Immobilization needs and technology programs

    International Nuclear Information System (INIS)

    In the aftermath of the Cold War, the US and Russia agreed to large reductions in nuclear weapons. To aid in the selection of long-term management options, DOE has undertaken a multifaceted study to select options for storage and disposition of plutonium in keeping with US policy that plutonium must be subjected to the highest standards of safety, security, and accountability. One alternative being considered is immobilization. To arrive at a suitable immobilization form, we first reviewed published information on high-level waste immobilization technologies and identified 72 possible plutonium immobilization forms to be prescreened. Surviving forms were further screened using multi-attribute utility analysis to determine the most promising technology families. Promising immobilization families were further evaluated to identify chemical, engineering, environmental, safety, and health problems that remain to be solved prior to making technical decisions as to the viability of using the form for long- term disposition of plutonium. From this evaluation, a detailed research and development plan has been developed to provide answers to these remaining questions

  18. Brain plasticity of rats exposed to prenatal immobilization stress

    OpenAIRE

    Badalyan B. Yu.; Tumasyan N. V.; Meliksetyan I. B.; Sahakyan I. K.; Abrahamyan S. S.; Galoyan A. A.

    2011-01-01

    Aim. This histochemical and immunohistochemical study was aimed at examining the brain cellular structures of newborn rats exposed to prenatal immobilization (IMO) stress. Methods. Histochemical method on detection of Ca2+-dependent acid phosphatase activity and ABC immunohistochemical technique. Results. Cell structures with radial astrocytes marker GFAP, neuroepithelial stem cell marker gene nestin, stem-cells marker and the hypothalamic neuroprotective proline-rich polypeptide PRP-1 (Galar...

  19. Electron Tomography of Cryo-Immobilized Plant Tissue: A Novel Approach to Studying 3D Macromolecular Architecture of Mature Plant Cell Walls In Situ

    OpenAIRE

    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.

    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 ...

  20. Skeletal fluorosis in immobilized extremities.

    Science.gov (United States)

    Rosenquist, J B

    1975-11-01

    The effect of immobilization on skeletal fluorosis was studied in growing rabbits. One hind leg was immobilized by an external fixation device extending below the wrist joint and above the knee joint, the extremity being in a straight position after severance of the sciatic nerve. The animals, aged 7 weeks at the beginning of the experiment, were given 10 mg of fluoride per kg body weight and day during 12 weeks. In the tibiae, development of the skeletal fluorosis was more irregular than that observed in previous studies of normally active animals, being most excessive in the mobile bone. The immobilization effect was most profound in the femora as the cortical thickness and the femur score were significantly higher than those in the mobile femora. It was suggested that an altered muscular activity was the reason for the observed changes. PMID:1189918

  1. Pathophysiology of immobilization osteoporosis

    Science.gov (United States)

    Doty, S. B.; DiCarlo, E. F.

    1995-01-01

    The reduction of gravity-related forces on the skeleton creates a type of osteoporosis that is unique because its severity is dependent on the mechanical stress bearing function of the skeleton as well as the length of time that the forces are absent or reduced. Bones that bear weight under normal conditions are more affected than bones that normally do not bear weight. The cytokine environment and the cells in the affected bones are altered in time so that stem cells produce fewer new cells and the differentiated cells tend to be less active. These alterations in the local environment of the affected parts appear to resemble those of age- and disease-associated systemic forms of osteoporosis. The osteoporosis produced as a result of the loss of normal activity however, appears to be at least partially reversible through remobilization, strenuous exercise, and--possibly in the future--cytokine therapy.

  2. Non-invasive screening for Alzheimer's disease by sensing salivary sugar using Drosophila cells expressing gustatory receptor (Gr5a immobilized on an extended gate ion-sensitive field-effect transistor (EG-ISFET biosensor.

    Directory of Open Access Journals (Sweden)

    Hui-Chong Lau

    Full Text Available Body fluids are often used as specimens for medical diagnosis. With the advent of advanced analytical techniques in biotechnology, the diagnostic potential of saliva has been the focus of many studies. We recently reported the presence of excess salivary sugars, in patients with Alzheimer's disease (AD. In the present study, we developed a highly sensitive, cell-based biosensor to detect trehalose levels in patient saliva. The developed biosensor relies on the overexpression of sugar sensitive gustatory receptors (Gr5a in Drosophila cells to detect the salivary trehalose. The cell-based biosensor was built on the foundation of an improved extended gate ion-sensitive field-effect transistor (EG-ISFET. Using an EG-ISFET, instead of a traditional ion-sensitive field-effect transistor (ISFET, resulted in an increase in the sensitivity and reliability of detection. The biosensor was designed with the gate terminals segregated from the conventional ISFET device. This design allows the construction of an independent reference and sensing region for simultaneous and accurate measurements of samples from controls and patients respectively. To investigate the efficacy of the cell-based biosensor for AD screening, we collected 20 saliva samples from each of the following groups: participants diagnosed with AD, participants diagnosed with Parkinson's disease (PD, and a control group composed of healthy individuals. We then studied the response generated from the interaction of the salivary trehalose of the saliva samples and the Gr5a in the immobilized cells on an EG-ISFET sensor. The cell-based biosensor significantly distinguished salivary sugar, trehalose of the AD group from the PD and control groups. Based on these findings, we propose that salivary trehalose, might be a potential biomarker for AD and could be detected using our cell-based EG-ISFET biosensor. The cell-based EG-ISFET biosensor provides a sensitive and direct approach for salivary sugar

  3. Hyaluronan Immobilized Polyurethane as a Blood Contacting Material

    International Nuclear Information System (INIS)

    Hyaluronan (hyaluronic acid, HA) was immobilized onto the surface of amino-functionalized polyurethane films with the goal of obtaining a novel kind of bio material which had the potential in blood-contacting applications. The amino-functionalized polyurethane was prepared by synthesized acidic polyurethane whose pendant carboxyl groups were treated with an excess amount of 1,3-diaminopropane in the presence of N,N-carbonyldiimidazole (CDI). Attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), Raman spectroscopy (RS), scanning electron microscopy (SEM), and water contact angle measurement were used to confirm the surface changes at each step of treatment, both in morphologies and chemical compositions. APTT and PT results showed that HA immobilization could prolong the blood coagulation time, thus HA-immobilized polyurethane (PU-HA) exhibited improved blood compatibility. Cytotoxicity analysis showed that the PU-HA films synthesized in this study were cytocompatible and could support human vein endothelial cells (HUVECs) adhesion and proliferation.

  4. Immobilization of Heparin: Approaches and Applications

    OpenAIRE

    Murugesan, Saravanababu; Xie, Jin; Linhardt, Robert J.

    2008-01-01

    Heparin, an anticoagulant, has been used in many forms to treat various diseases. These forms include soluble heparin and heparin immobilized to supporting matrices by physical adsorption, by covalent chemical methods and by photochemical attachment. These immobilization methods often require the use of spacers or linkers. This review examines and compares various techniques that have been used for the immobilization of heparin as well as applications of these immobilized heparins. In the app...

  5. Production of cyclodextrin glycosyltransferase by immobilized Bacillus sp. on chitosan matrix.

    Science.gov (United States)

    Eş, Ismail; Ribeiro, Maycon Carvalho; Dos Santos Júnior, Samuel Rodrigues; Khaneghah, Amin Mousavi; Rodriguez, Armando Garcia; Amaral, André Corrêa

    2016-10-01

    The whole-cell immobilization on chitosan matrix was evaluated. Bacillus sp., as producer of CGTase, was grown in solid-state and batch cultivation using three types of starches (cassava, potato and cornstarch). Biomass growth and substrate consumption were assessed by flow cytometry and modified phenol-sulfuric acid assays, respectively. Qualitative analysis of CGTase production was determined by colorless area formation on solid culture containing phenolphthalein. Scanning electron microscopy (SEM) analysis demonstrated that bacterial cells were immobilized on chitosan matrix efficiently. Free cells reached very high numbers during batch culture while immobilized cells maintained initial inoculum concentration. The maximum enzyme activity achieved by free cells was 58.15 U ml(-1) (36 h), 47.50 U ml(-1) (36 h) and 68.36 U ml(-1) (36 h) on cassava, potato and cornstarch, respectively. CGTase activities for immobilized cells were 82.15 U ml(-1) (18 h) on cassava, 79.17 U ml(-1) (12 h) on potato and 55.37 U ml(-1) (in 6 h and max 77.75 U ml(-1) in 36 h) on cornstarch. Application of immobilization technique increased CGTase activity significantly. The immobilized cells produced CGTase with higher activity in a shorter fermentation time comparing to free cells. PMID:27194141

  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. PMID:26853541

  7. Immobile Complex Verbs in Germanic

    DEFF Research Database (Denmark)

    Vikner, Sten

    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...... 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...... the V° requirements or the V* requirements. Haider (1993, p. 62) and Koopman (1995), who also discuss such immobile verbs, only account for verbs with two prefix-like parts (e.g., German uraufführen ‘to perform (a play) for the first time' or Dutch herinvoeren ‘to reintroduce'), not for the more...

  8. Treatability of cheese whey for single-cell protein production in nonsterile systems: Part I. Optimal condition for lactic acid fermentation using a microaerobic sequencing batch reactor (microaerobic SBR) with immobilized Lactobacillus plantarum TISTR 2265 and microbial communities.

    Science.gov (United States)

    Monkoondee, Sarawut; Kuntiya, Ampin; Chaiyaso, Thanongsak; Leksawasdi, Noppol; Techapun, Charin; Kawee-Ai, Arthitaya; Seesuriyachan, Phisit

    2016-05-18

    Cheese whey contains a high organic content and causes serious problems if it is released into the environment when untreated. This study aimed to investigate the optimum condition of lactic acid production using the microaerobic sequencing batch reactor (microaerobic SBR) in a nonsterile system. The high production of lactic acid was achieved by immobilized Lactobacillus plantarum TISTR 2265 to generate an acidic pH condition below 4.5 and then to support single-cell protein (SCP) production in the second aerobic sequencing batch reactor (aerobic SBR). A hydraulic retention time (HRT) of 4 days and a whey concentration of 80% feeding gave a high lactic acid yield of 12.58 g/L, chemical oxygen demand (COD) removal of 62.38%, and lactose utilization of 61.54%. The microbial communities in the nonsterile system were dominated by members of lactic acid bacteria, and it was shown that the inoculum remained in the system up to 330 days. PMID:26178366

  9. Use of microorganism-immobilized polyurethane foams to absorb and degrade oil on water surface

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Y.S.; Maeng, J.; Kim, S.J. [Korea Ocean Research and Development Inst., Ansan (Korea). Microbiology Lab.

    2000-07-01

    Highly oil-absorbent polyurethane foam (PUF) materials were obtained by polymerizing polyether polyol mixture and carbodiimide-modified D-methyl diisocyanate in a weight ratio of 10:2. The foam materials were prepared to contain inorganic nutrients (slow-release fertilizer; SRF) and oil-degrading yeast cells, Yarrowia lipolytica 180, to be applied for removal of oil films on surface waters through absorption and biodegradation after oil spills. PUFs absorbed 7-9 times their own weight of Arabian light crude oil and the oil absorbency appeared to improve as the ratio of surface area to foam weight increased. PUFs showed excellent floatability which was maintained for more than 6 months in sea water, and less than 5% of the absorbed oil was released when the foams were left on water for more than 10 days. For immobilization of yeast cells into PUFs, various immobilization techniques were tested to compare their oil degrading ability and the maintenance thereof. All immobilized cells showed oil degrading abilities as good as those of free cells immediately after the preparation of PUFs, however, the activity of chitin-immobilized cells remained at a high level for the longest period of preservation. The high efficiency of oil absorption and oil degradation by PUF-immobilized yeast cells suggested that PUF-immobilized cells have a high potential as a bioremediation technique for the treatment of oil films on surface waters. (orig.)

  10. Use of microorganism-immobilized polyurethane foams to absorb and degrade oil on water surface.

    Science.gov (United States)

    Oh, Y S; Maeng, J; Kim, S J

    2000-09-01

    Highly oil-absorbent polyurethane foam (PUF) materials were obtained by polymerizing polyether polyol mixture and carbodiimide-modified D-methyl diisocyanate in a weight ratio of 10:2. The foam materials were prepared to contain inorganic nutrients (slow-release fertilizer; SRF) and oil-degrading yeast cells, Yarrowia lipolytica 180, to be applied for removal of oil films on surface waters through absorption and biodegradation after oil spills. PUFs absorbed 7-9 times their own weight of Arabian light crude oil and the oil absorbency appeared to improve as the ratio of surface area to foam weight increased. PUFs showed excellent floatability which was maintained for more than 6 months in sea water, and less than 5% of the absorbed oil was released when the foams were left on water for more than 10 days. For immobilization of yeast cells into PUFs, various immobilization techniques were tested to compare their oil degrading ability and the maintenance thereof. All immobilized cells showed oil degrading abilities as good as those of free cells immediately after the preparation of PUFs, however, the activity of chitin-immobilized cells remained at a high level for the longest period of preservation. The high efficiency of oil absorption and oil degradation by PUF-immobilized yeast cells suggested that PUF-immobilized cells have a high potential as a bioremediation technique for the treatment of oil films on surface waters. PMID:11030581

  11. Surface characterization, protein adsorption, and initial cell-surface reactions on glutathione and 3-mercapto-1,2,-propanediol immobilized to gold.

    Science.gov (United States)

    Kanagaraja, S; Alaeddine, S; Eriksson, C; Lausmaa, J; Tengvall, P; Wennerberg, A; Nygren, H

    1999-09-15

    Monolayers of glutathione (GSH) and 3-mercapto-1,2-propanediol (MG) on gold were tested for their bioreactivity by assessing the degree of inflammatory reaction as manifested by the adherence and activation of platelets and white blood cells (wbc) after exposure to blood ex vivo. Surface composition was characterized by XPS, and noncontact optical profilometry was used to determine surface roughness. The thickness and composition of the adsorbed protein layers were measured by ellipsometry/antibody techniques in vitro. Cell adhesion and activation were quantified by acridine orange staining, fluorescein-diacetate staining, and by specific antibodies against cell membrane antigens. Distinct differences among the surfaces were observed relative to the amounts and composition of adsorbed plasma proteins and the adhesion and activation of platelets (CD62P-exposure) and wbc (CD11b/CD18-exposure). GSH surfaces, which adsorbed the least amount of plasma protein, caused the least adherence and activation of platelets (CD62P), followed by the highest activation of wbc (CD11b/18). The MG surfaces caused a rapid recruitment and activation of platelets (CD62P), followed by a lower activation of wbc (CD11b/18). Thus it appears that measurements of the initial adsorption of plasma protein from anticoagulated plasma and of the adhesion and activation of platelets after 8 min of exposure to whole blood cannot be used to predict accurately the adhesion and activation behavior of inflammatory cells after longer periods (2 h) of exposure on different surfaces. PMID:10398020

  12. Nanodevices for the immobilization of therapeutic enzymes.

    Science.gov (United States)

    Bosio, Valeria E; Islan, Germán A; Martínez, Yanina N; Durán, Nelson; Castro, Guillermo R

    2016-06-01

    Therapeutic enzymes are one of the most promising applications of this century in the field of pharmaceutics. Biocatalyst properties can be improved by enzyme immobilization on nano-objects, thereby increasing stability and reusability and also enhancing the targeting to specific tissues and cells. Therapeutic biocatalyst-nanodevice complexes will provide new tools for the diagnosis and treatment of old and newly emerging pathologies. Among the advantages of this approach are the wide span and diverse range of possible materials and biocatalysts that promise to make the matrix-enzyme combination a unique modality for therapeutic delivery. This review focuses on the most significant techniques and nanomaterials used for enzyme immobilization such as metallic superparamagnetic, silica, and polymeric and single-enzyme nanoparticles. Finally, a review of the application of these nanodevices to different pathologies and modes of administration is presented. In short, since therapeutic enzymes constitute a highly promising alternative for treating a variety of pathologies more effectively, this review is aimed at providing the comprehensive summary needed to understand and improve this burgeoning area. PMID:25641329

  13. Immobilization of Papain on Siliceous Mesocellular Foam

    OpenAIRE

    ZOU Ze-Chang,WEI Qi,NA Wei,SUN Hui,NIE Zuo-Ren

    2009-01-01

    Siliceous mesocellular foam (MCF) was employed as carriers in the immobilization of papain, and the properties and the stabilities of the immobilized enzyme were investigated in detail. The results show that the amount of papain immobilized on MCF material reaches 334 mg/g MCF. The optimal pH and reaction temperature of the immobilized papain are 7.5 and 50¡䪠respectively. The Michaelis constant (Km) of immobilized papain is disclosed as 6.99¡�0-3mol/L by the Lineweaver-Burk plot at 37¡䬠The im...

  14. Uncovering immobilized trypsin digestion features from large-scale proteome data generated by high-resolution mass spectrometry

    OpenAIRE

    Sun, Liangliang; Zhu, Guijie; Yan, Xiaojing; Mou, Si; Dovichi, Norman J.

    2014-01-01

    Immobilized trypsin produces very fast protein digestion, which is attractive for application to high throughput bottom-up proteomics. While there is a rich literature on the preparation of immobilized trypsin, there are very few studies that investigate its application to complex proteomic samples. In this work, we compared solution-phase trypsin with trypsin immobilized on magnetic microspheres for digestion of two complex proteomes, E. coli and the MCF7 cell line. The digests were separate...

  15. Albumin-coated monodisperse magnetic poly(glycidyl methacrylate) microspheres with immobilized antibodies: application to the capture of epithelial cancer cells

    Czech Academy of Sciences Publication Activity Database

    Horák, Daniel; Svobodová, Z.; Autebert, J.; Coudert, B.; Plichta, Zdeněk; Královec, K.; Bílková, Z.; Viovy, J.-L.

    101A, č. 1 (2013), s. 23-32. ISSN 1549-3296 R&D Projects: GA ČR GA203/09/0857; GA ČR GCP207/12/J013; GA MŠk 7E09109 EU Projects: European Commission(XE) 228980 - CAMINEMS Institutional research plan: CEZ:AV0Z40500505 Institutional support: RVO:61389013 Keywords : magnetism * microsphere * cells Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 2.841, year: 2013

  16. Anti-EpCAM-immobilized albumin-coated monodisperse magnetic poly(glycidyl methacrylate) microspheres for detection of circulating tumor cells

    Czech Academy of Sciences Publication Activity Database

    Horák, Daniel; Svobodová, Z.; Autebert, J.; Bílková, Z.; Viovy, J.-L.

    Vancouver : Faculty of Pharmaceutical Sciences, The University of British Columbia, 2012. Talk 75. [International Conference on the Scientific and Clinical Applications of Magnetic Carriers /9./. 22.05.2012-26.05.2012, Minneapolis] R&D Projects: GA MŠk 7E09109 EU Projects: European Commission(XE) 228980 - CAMINEMS Institutional research plan: CEZ:AV0Z40500505 Institutional support: RVO:61389013 Keywords : magnetic * microspheres * circulating tumor cells Subject RIV: CD - Macromolecular Chemistry

  17. 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. PMID:20580809

  18. Kefir immobilized on corn grains as biocatalyst for lactic acid fermentation and sourdough bread making.

    Science.gov (United States)

    Plessas, Stavros; Alexopoulos, Athanasios; Bekatorou, Argyro; Bezirtzoglou, Eugenia

    2012-12-01

    The natural mixed culture kefir was immobilized on boiled corn grains to produce an efficient biocatalyst for lactic acid fermentation with direct applications in food production, such as sourdough bread making. The immobilized biocatalyst was initially evaluated for its efficiency for lactic acid production by fermentation of cheese whey at various temperatures. The immobilized cells increased the fermentation rate and enhanced lactic acid production compared to free kefir cells. Maximum lactic acid yield (68.8 g/100 g) and lactic acid productivity (12.6 g/L per day) were obtained during fermentation by immobilized cells at 37 °C. The immobilized biocatalyst was then assessed as culture for sourdough bread making. The produced sourdough breads had satisfactory specific loaf volumes and good sensory characteristics. Specifically, bread made by addition of 60% w/w sourdough containing kefir immobilized on corn was more resistant regarding mould spoilage (appearance during the 11(th) day), probably due to higher lactic acid produced (2.86 g/Kg of bread) compared to the control samples. The sourdough breads made with the immobilized biocatalyst had aroma profiles similar to that of the control samples as shown by headspace SPME GC-MS analysis. PMID:23170776

  19. Immobilization of Microbes for Bioremediation of Crude Oil Polluted Environments: A Mini Review.

    Science.gov (United States)

    Bayat, Zeynab; Hassanshahian, Mehdi; Cappello, Simone

    2015-01-01

    Petroleum hydrocarbons are the most common environmental pollutants in the world and oil spills pose a great hazard to terrestrial and marine ecosystems. Oil pollution may arise either accidentally or operationally whenever oil is produced, transported, stored and processed or used at sea or on land. Oil spills are a major menace to the environment as they severely damage the surrounding ecosystems. To improve the survival and retention of the bioremediation agents in the contaminated sites, bacterial cells must be immobilized. Immobilized cells are widely tested for a variety of applications. There are many types of support and immobilization techniques that can be selected based on the sort of application. In this review article, we have discussed the potential of immobilized microbial cells to degrade petroleum hydrocarbons. In some studies, enhanced degradation with immobilized cells as compared to free living bacterial cells for the treatment of oil contaminated areas have been shown. It was demonstrated that immobilized cell to be effective and is better, faster, and can be occurred for a longer period. PMID:26668662

  20. Nuclear waste immobilization. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Ringwood, A.E.; Sinclair, W.; McLaughlin, G.M.

    1979-11-20

    United States defense nuclear wastes are presently in tank storage, largely as sludges comprising Fe, Mn, Ni, U and Na oxides and hydroxides, together with 0.5 to 5 percent of fission products and actinides (exclusive of uranium). The relative proportions of Al, Fe, Mn, Ni, U and Na in the sludges from different tanks vary considerably, except that (Fe + Al + Mn) are by far the major components and Fe is more abundant than Mn. Typical compositions of some calcined sludges from Savannah River are given. This paper briefly describes how the SYNROC process, utilizing straightforward technology, can be readily adapted to the problem of defense waste immobilization, yielding a dense, inert, ceramic waste-form, SYNROC-D. Two classes of processes are discussed - one designed to immobilize sludges containing normal amounts of sodium and the other designed for otherwise similar sludges which are, however, strongly depleted in sodium as a result of more efficient washing procedures.

  1. Nuclear waste immobilization. Progress report

    International Nuclear Information System (INIS)

    United States defense nuclear wastes are presently in tank storage, largely as sludges comprising Fe, Mn, Ni, U and Na oxides and hydroxides, together with 0.5 to 5 percent of fission products and actinides (exclusive of uranium). The relative proportions of Al, Fe, Mn, Ni, U and Na in the sludges from different tanks vary considerably, except that (Fe + Al + Mn) are by far the major components and Fe is more abundant than Mn. Typical compositions of some calcined sludges from Savannah River are given. This paper briefly describes how the SYNROC process, utilizing straightforward technology, can be readily adapted to the problem of defense waste immobilization, yielding a dense, inert, ceramic waste-form, SYNROC-D. Two classes of processes are discussed - one designed to immobilize sludges containing normal amounts of sodium and the other designed for otherwise similar sludges which are, however, strongly depleted in sodium as a result of more efficient washing procedures

  2. From protein engineering to immobilization

    DEFF Research Database (Denmark)

    Singh, Raushan Kumar; Tiwari, Manish Kumar; Singh, Ranjitha; Lee, Jung-Kul

    2013-01-01

    in protein engineering have revolutionized the development of commercially available enzymes into better industrial catalysts. Protein engineering aims at modifying the sequence of a protein, and hence its structure, to create enzymes with improved functional properties such as stability, specific...... in improved enzyme stability. Protein engineering and immobilization techniques are sequential and compatible approaches for the improvement of enzyme properties. The present review highlights and summarizes various studies that have aimed to improve the biochemical properties of industrially...

  3. Influence of immobilization on the stability of pTG201 recombinant plasmid in some strains of Escherichia coli.

    OpenAIRE

    Nasri, M; Sayadi, S.; Barbotin, J N; Dhulster, P; Thomas, D.

    1987-01-01

    The stability of pTG201 plasmid was examined by continuous culture in three genetically different Escherichia coli hosts. Two types of experiment were carried out, one with free cells and one with immobilized cells. When cells were cultivated in free continuous culture in the absence of antibiotic selection, the plasmid was maintained with various degrees of stability in the three host organisms. By contrast, in continuous culture with immobilized cells, plasmid pTG201 was stably maintained i...

  4. Phosphopeptide enrichment by immobilized metal affinity chromatography

    DEFF Research Database (Denmark)

    Thingholm, Tine E.; Larsen, Martin R.

    2016-01-01

    binding capacity. After binding, the enriched phosphopeptides are released from the metal ions using alkaline buffers of pH 10–11, EDTA, or phosphate-containing buffers. Here we describe a protocol for IMAC using Fe 3+ for phosphopeptide enrichment. The principles are illustrated on a semi-complex peptide......Immobilized metal affinity chromatography (IMAC) has been the method of choice for phosphopeptide enrichment prior to mass spectrometric analysis for many years and it is still used extensively in many laboratories. Using the affinity of negatively charged phosphate groups towards positively...... charged metal ions such as Fe3+, Ga3+, Al3+, Zr4+, and Ti4+ has made it possible to enrich phosphorylated peptides from peptide samples. However, the selectivity of most of the metal ions is limited, when working with highly complex samples, e.g., whole-cell extracts, resulting in contamination from...

  5. Modifying enzyme activity and selectivity by immobilization

    OpenAIRE

    Rodrigues, Rafael C.; Ortiz, Claudia; Berenguer Murcia, Ángel; Torres, Rodrigo; Fernández Lafuente, Roberto

    2013-01-01

    Immobilization of enzymes may produce alterations in their observed activity, specificity or selectivity. Although in many cases an impoverishment of the enzyme properties is observed upon immobilization (caused by the distortion of the enzyme due to the interaction with the support) in some instances such properties may be enhanced by this immobilization. These alterations in enzyme properties are sometimes associated with changes in the enzyme structure. Occasionally, these variations will ...

  6. 钛表面固定特异性识别内皮祖细胞的多肽适配子%Immobilization of Peptide Aptamer of Specific Indentification of Endothelial Progenitor Cell on Titanium Surface

    Institute of Scientific and Technical Information of China (English)

    陈卓玥; 李全利; 赵元聪; 陈佳龙; 游天雪; 熊开琴; 黄楠

    2011-01-01

    在钛表面固定可与循环血液中的内皮祖细胞(EPC)特异性结合的多肽适配子,构建内皮祖细胞的特异性识别表面,用于心血管材料的表面改性.首先,采用固相合成法合成可与EPC特异性结合的多肽适配子,其序列为TPSLEQRTVYAK,并在羧基端进行生物素修饰;然后,采用磷酸处理钛表面,在钛表面获得化学键合的羟基,该羟基化表面与3-氨丙基三乙氧基硅烷反应,在钛表面获得游离的氨基,进一步通过碳二亚胺(EDC)介导,在钛表面接枝上生物素;最后,通过生物素-亲和素识别体系,实现EPC特异性多肽适配子在钛表面的固定.采用场发射扫描电子显微镜(SEM)、漫反射红外光谱(DR-FTIR)和免疫荧光分析等手段对样品进行了表征.本研究为多肽适配子在材料表面的固定提供了一种有效的方法,为进一步的生物医学应用研究提供了基础.%In vivo spontaneous endothelialization of cardiovascular materials is thought to be a promising approach to prevent the formation of thrombus and restenosis. Capturing endothelial progenitor cells (EPC)from blood and inducing EPC to grow on the surface of stents is a new strategy for this purpose. In this study,we developed a facile and effective approach to construct a surface that possessed a high affinity and specificity to EPCs by binding peptide aptamer. In order to introduce primary amine groups to covalently immobilize biotin, the titanium surface was treated by phosphoric acid solution to obtain the hydroxyl groups which were used to covalently immobilize aminopropyltriethoxysilane. Furthermore, the biotin was grafted onto the amine functionalized titanium surface by carbodiimide (EDC)-mediated. Finally, using layer-by-layer self-assembly method, biotinylated peptide aptamer was fixed on the titanium surface by the biofin-avidin recognition system.The results of fourier transform infrared spectroscopy ( FTIR), fluorescence labeling method and scanning

  7. Properties of immobilized papain by radiation polymerization

    International Nuclear Information System (INIS)

    Papain was immobilized by the radiation polymerization of various monomers at low temperatures and the effects of the polymer matrix on the enzyme activity and thermal stability of the immobilized enzymes were studied. The activity of the immobilized enzymes prepared from monofunctional (acrylate and methacrylate) monomers was higher than that from bifunctional (bismethacrylate) monomers and that from polyoxyethylene dimethacrylate monomers increased with an increase in the number of oxyethylene units. The thermal stability of the immobilized enzymes prepared from hydrophilic monomers was higher than that from hydrophobic monomers and increased markedly with increasing monomer concentration. (author)

  8. Immobilization of denitrifying bacteria with polymer carrier produced by radiation polymerization

    International Nuclear Information System (INIS)

    Polymer carriers were prepared from acrylamide, glycidyl methacrylate (GMA) and mixed monomer of glycidyl methacrylate (GMA) and 2-hydroxyethyl methacrylate (HEMA) by radiation polymerization. Two denitrifying strains of bacteria were immobilized into the polymer matrix. The denitrifying activity of immobilized cells with these carriers was related to the monomer composition of polymers. The optimum monomer composition was 50% in polyacrylamide and 5:15, 5:20, 10:20 % in poly (GMA-HEMA). (author)

  9. Nitric Acid-Treated Carbon Fibers with Enhanced Hydrophilicity for Candida tropicalis Immobilization in Xylitol Fermentation

    OpenAIRE

    Le Wang; Na Liu; Zheng Guo; Dapeng Wu; Weiwei Chen; Zheng Chang; Qipeng Yuan; Ming Hui; Jinshui Wang

    2016-01-01

    Nitric acid (HNO3)-treated carbon fiber (CF) rich in hydrophilic groups was applied as a cell-immobilized carrier for xylitol fermentation. Using scanning electron microscopy, we characterized the morphology of the HNO3-treated CF. Additionally, we evaluated the immobilized efficiency (IE) of Candida tropicalis and xylitol fermentation yield by investigating the surface properties of nitric acid treated CF, specifically, the acidic group content, zero charge point, degree of moisture and cont...

  10. Immobilized epidermal growth factor stimulates persistent, directed keratinocyte migration via activation of PLCγ1.

    Science.gov (United States)

    Kim, Chloe S; Mitchell, Isaiah P; Desotell, Anthony W; Kreeger, Pamela K; Masters, Kristyn S

    2016-07-01

    Epidermal growth factor (EGF) is a critical element in dermal repair, but EGF-containing wound dressings have not been successful clinically. However, these dressings have delivered only soluble EGF, and the native environment provides both soluble and matrix-bound EGF. To address our hypothesis that tethered EGF can stimulate cell behaviors not achievable with soluble EGF, we examined single-cell movement and signaling in human immortalized HaCaT keratinocytes treated with soluble or immobilized EGF. Although both EGF treatments increased collective sheet displacement and individual cell speed, only cells treated with immobilized EGF exhibited directed migration, as well as 2-fold greater persistence compared with soluble EGF. Immunofluorescence showed altered EGF receptor (EGFR) trafficking, where EGFR remained membrane-localized in the immobilized EGF condition. Cells treated with soluble EGF demonstrated higher phosphorylated ERK1/2, and cells on immobilized EGF exhibited higher pPLCγ1, which was localized at the leading edge. Treatment with U0126 inhibited migration in both conditions, demonstrating that ERK1/2 activity was necessary but not responsible for the observed differences. In contrast, PLCγ1 inhibition with U73122 significantly decreased persistence on immobilized EGF. Combined, these results suggest that immobilized EGF increases collective keratinocyte displacement via an increase in single-cell migration persistence resulting from altered EGFR trafficking and PLCγ1 activation.-Kim, C. S., Mitchell, I. P., Desotell, A. W., Kreeger, P. K., Masters, K. S. Immobilized epidermal growth factor stimulates persistent, directed keratinocyte migration via activation of PLCγ1. PMID:27025961

  11. Immobilization of Escherichia coli containing ω‐transaminase activity in LentiKats®

    DEFF Research Database (Denmark)

    Cárdenas‐Fernández, Max; Lima Afonso Neto, Watson; López, Carmen; Álvaro, Gregorio; Tufvesson, Pär; Woodley, John M.

    2012-01-01

    Whole Escherichia coli cells overexpressing ω‐transaminase (ω‐TA) and immobilized cells entrapped in LentiKats® were used as biocatalysts in the asymmetric synthesis of the aromatic chiral amines 1‐phenylethylamine (PEA) and 3‐amino‐1‐phenylbutane (APB). Whole cells were permeabilized with...

  12. Airlift bioreactor containing chitosan-immobilized Sphingobium sp. P2 for treatment of lubricants in wastewater

    International Nuclear Information System (INIS)

    Highlights: ► Sphingobium sp. P2 effectively degraded various lubricant samples. ► Efficiency of Sphingobium sp. P2 increased after immobilization on chitosan. ► High removal efficiency was due to both sorption and degradation processes. ► The immobilized bacteria (4 g L−1) were applied in internal loop airlift bioreactor. ► The bioreactor continuously removed lubricant from emulsified wastewater. - Abstract: An internal loop airlift bioreactor containing chitosan-immobilized Sphingobium sp. P2 was applied for the removal of automotive lubricants from emulsified wastewater. The chitosan-immobilized bacteria had higher lubricant removal efficiency than free and killed-immobilized cells because they were able to sorp and degrade the lubricants simultaneously. In a semi-continuous batch experiment, the immobilized bacteria were able to remove 80–90% of the 200 mg L−1 total petroleum hydrocarbons (TPH) from both synthetic and carwash wastewater. The internal loop airlift bioreactor, containing 4 g L−1 immobilized bacteria, was later designed and operated at 2.0 h HRT (hydraulic retention time) for over 70 days. At a steady state, the reactor continuously removed 85 ± 5% TPH and 73 ± 11% chemical oxygen demand (COD) from the carwash wastewater with 25–200 mg L−1 amended lubricant. The internal loop airlift reactor's simple operation and high stability demonstrate its high potential for use in treating lubricants in emulsified wastewater from carwashes and other industries.

  13. Uranium immobilization and nuclear waste

    International Nuclear Information System (INIS)

    Considerable information useful in nuclear waste storage can be gained by studying the conditions of uranium ore deposit formation. Further information can be gained by comparing the chemistry of uranium to nuclear fission products and other radionuclides of concern to nuclear waste disposal. Redox state appears to be the most important variable in controlling uranium solubility, especially at near neutral pH, which is characteristic of most ground water. This is probably also true of neptunium, plutonium, and technetium. Further, redox conditions that immobilize uranium should immobilize these elements. The mechanisms that have produced uranium ore bodies in the Earth's crust are somewhat less clear. At the temperatures of hydrothermal uranium deposits, equilibrium models are probably adequate, aqueous uranium (VI) being reduced and precipitated by interaction with ferrous-iron-bearing oxides and silicates. In lower temperature roll-type uranium deposits, overall equilibrium may not have been achieved. The involvement of sulfate-reducing bacteria in ore-body formation has been postulated, but is uncertain. Reduced sulfur species do, however, appear to be involved in much of the low temperature uranium precipitation. Assessment of the possibility of uranium transport in natural ground water is complicated because the system is generally not in overall equilibrium. For this reason, Eh measurements are of limited value. If a ground water is to be capable of reducing uranium, it must contain ions capable of reducing uranium both thermodynamically and kinetically. At present, the best candidates are reduced sulfur species

  14. 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.

  15. Surface immobilized protein multilayers for cell seeding

    Czech Academy of Sciences Publication Activity Database

    Brynda, Eduard; Pacherník, J.; Houska, Milan; Pientka, Zbyněk; Dvořák, P.

    2005-01-01

    Roč. 21, č. 17 (2005), s. 7877. ISSN 0743-7463 R&D Projects: GA ČR(CZ) GA203/02/1326; GA ČR GA102/03/0633; GA MŠk(CZ) LN00A065 Keywords : surface modification * layer-by-layer deposition * protein multilayers Subject RIV: CE - Biochemistry Impact factor: 3.705, year: 2005

  16. Acid Black 48 dye biosorption using Saccharomyces cerevisiae immobilized with treated sugarcane bagasse.

    Science.gov (United States)

    Mitter, E K; Corso, C R

    2012-01-01

    The textile industry consumes large quantities of water and chemicals, especially in dyeing and finishing processes. Textile dye adsorption can be accomplished with natural or synthetic compounds. Cell immobilization using biomaterials allows the reduction of toxicity and mechanical resistance and opens spaces within the matrix for cell growth. The use of natural materials, such as sugarcane bagasse, is promising due to the low costs involved. The aim of the present study was to evaluate the use of sugarcane bagasse treated with either polyethyleneimine (PEI), NaOH or distilled water in the cell immobilization of Saccharomyces cerevisiae for textile dye removal. Three different adsorption tests were conducted: treated sugarcane bagasse alone, free yeast cells and bagasse-immobilized yeast cells. Yeast immobilization was 31.34% with PEI-treated bagasse, 8.56% with distilled water and 22.54% with NaOH. PEI-treated bagasse exhibited the best removal rates of the dye at all pH values studied (2.50, 4.50 and 6.50). The best Acid Black 48 adsorption rates were obtained with use of free yeast cells. At pH 2.50, 1 mg of free yeast cells was able to remove 5488.49 g of the dye. The lowest adsorption capacity rates were obtained using treated bagasse alone. However, the use of bagasse-immobilized cells increased adsorption efficiency from 20 to 40%. The use of immobilized cells in textile dye removal is very attractive due to adsorbed dye precipitation, which eliminates the industrial need for centrifugation processes. Dye adsorption using only yeast cells or sugarcane bagasse requires separation methods. PMID:22864427

  17. Plutonium Immobilization Can Loading Equipment Review

    International Nuclear Information System (INIS)

    This report lists the operations required to complete the Can Loading steps on the Pu Immobilization Plant Flow Sheets and evaluates the equipment options to complete each operation. This report recommends the most appropriate equipment to support Plutonium Immobilization Can Loading operations

  18. 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.

  19. Electrochemically Controlled Reconstitution of Immobilized Ferritins for Bioelectronic Applications

    Science.gov (United States)

    Kim, Jae-Woo; Choi, Sang H.; Lillehei, Peter T.; Chu, Sang-Hong; King, Glen C.; Watt, Gerald D.

    2007-01-01

    Site-specific reconstituted nanoparticles were fabricated via electrochemically-controlled biomineralization through the immobilization of biomolecules. The work reported herein includes the immobilization of ferritin with various surface modifications, the electrochemical biomineralization of ferritins with different inorganic cores, and the electrocatalytic reduction of oxygen on the reconstituted Pt-cored ferritins. Protein immobilization on the substrate is achieved by anchoring ferritins with dithiobis-N-succinimidyl propionate (DTSP). A reconstitution process of site-specific electrochemical biomineralization with a protein cage loads ferritins with different core materials. The ferritin acts as a nano-scale template, a biocompatible cage, and a separator between the nanoparticles. This first demonstration of electrochemically controlled site-specific reconstitution of biomolecules provides a new tool for biomineralization and opens the way to produce the bio-templated nanoparticles by electrochemical control. The nanosized platinum-cored ferritins on gold displayed good catalytic activity for the electrochemical reduction of oxygen, which is applicable to biofuel cell applications. This results in a smaller catalyst loading on the electrodes for fuel cells or other bioelectronic devices.

  20. Immobilization of recombinant vault nanoparticles on solid substrates.

    Science.gov (United States)

    Xia, Yun; Ramgopal, Yamini; Li, Hai; Shang, Lei; Srinivas, Parisa; Kickhoefer, Valerie A; Rome, Leonard H; Preiser, Peter R; Boey, Freddy; Zhang, Hua; Venkatraman, Subbu S

    2010-03-23

    Native vaults are nanoscale particles found abundantly in the cytoplasm of most eukaryotic cells. They have a capsule-like structure with a thin shell surrounding a "hollow" interior compartment. Recombinant vault particles were found to self-assemble following expression of the major vault protein (MVP) in a baculovirus expression system, and these particles are virtually identical to native vaults. Such particles have been recently studied as potential delivery vehicles. In this study, we focus on immobilization of vault particles on a solid substrate, such as glass, as a first step to study their interactions with cells. To this end, we first engineered the recombinant vaults by fusing two different tags to the C-terminus of MVP, a 3 amino acid RGD peptide and a 12 amino acid RGD-strep-tag peptide. We have demonstrated two strategies for immobilizing vaults on solid substrates. The barrel-and-cap structure of vault particles was observed for the first time, by atomic force microscopy (AFM), in a dry condition. This work proved the feasibility of immobilizing vault nanoparticles on a material surface, and the possibility of using vault nanoparticles as localized and sustainable drug carriers as well as a biocompatible surface moiety. PMID:20146454

  1. 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.

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

    International Nuclear Information System (INIS)

    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.

  3. 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.

  4. A novel approach to monitor stress-induced physiological responses in immobilized microorganisms.

    Science.gov (United States)

    Alonso, Saúl; Rendueles, Manuel; Díaz, Mario

    2015-04-01

    Microbial cell immobilization has long been considered as a potential bioprocessing strategy to increase both microorganisms' tolerance and fitness in fermentation systems. To date, little emphasis has been put on how the entrapped cells respond to the bioprocessing stresses encountered during the cultivation. The present work presents for the first time a methodology to decipher the real health status of the entrapped microorganisms by combining multiparameter flow cytometry with confocal fluorescence microscopy as monitoring tools. Comparison between resting free and immobilized cell-based systems enabled to characterize the spatial-temporal physiological response of entrapped Pseudomonas taetrolens cells during lactobionic acid production in submerged cultivation. Whereas cellular leakage from beads led to planktonic cells that faced a progressive loss of membrane integrity, immobilized cells underwent a prompt stress-induced physiological response featured by the predominance of cellular damaging. Moreover, visualization without matrix de-entrapment through confocal fluorescence microscopy revealed the overtime formation of cellular micro-colonies inside the beads. These micro-colonies comprised a shell made of dead cells, whereas the inward cells remained metabolically active. The proposed approach herein raises the possibility of using flow cytometry and confocal fluorescence microscopy as indicators of microbial cell immobilization, providing further key information on the health status and robustness of entrapped microorganisms. PMID:25776062

  5. 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.

  6. Radioactive seed immobilization techniques for interstitial brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Yan, K.; Podder, T.; Buzurovic, I.; Hu, Y.; Dicker, A.; Valicenti, R.; Yu, Y. [Thomas Jefferson University, Department of Radiation Oncology, Philadelphia, PA (United States); Messing, E. [University of Rochester, Departments of Urology and Surgery, Rochester, NY (United States); Rubens, D. [University of Rochester, Departments of Imaging Science and Surgery, Rochester, NY (United States); Sarkar, N. [Vanderbilt University, Department of Mechanical Engineering, Nashville, TN (United States); Ng, W. [Nangyang Technical University, School of Mechanical and Aerospace Engineering, Singapore (Singapore)

    2008-06-15

    In prostate brachytherapy, seeds can detach from their deposited sites and move locally in the pelvis or migrate to distant sites including the pulmonary and cardiac regions. Undesirable consequences of seed migration include inadequate dose coverage of the prostate and tissue irradiation effects at the site of migration. Thus, it is clinically important to develop seed immobilization techniques. We first analyze the possible causes for seed movement, and propose three potential techniques for seed immobilization: (1) surgical glue, (2) laser coagulation and (3) diathermy coagulation. The feasibility of each method is explored. Experiments were carried out using fresh bovine livers to investigate the efficacy of seed immobilization using surgical glue. Results have shown that the surgical glue can effectively immobilize the seeds. Evaluation of the radiation dose distribution revealed that the non-immobilized seed movement would change the planned isodose distribution considerably; while by using surgical glue method to immobilize the seeds, the changes were negligible. Prostate brachytherapy seed immobilization is necessary and three alternative mechanisms are promising for addressing this issue. Experiments for exploring the efficacy of the other two proposed methods are ongoing. Devices compatible with the brachytherapy procedure will be designed in future. (orig.)

  7. 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.

  8. The effects of the fermentation with immobilized yeast and different cherry varieties on the quality of cherry brandy

    OpenAIRE

    Miličević, B.; Babić, J.; Šubarić, D.; Ačkar, Đurđica; Jozinović, A.; Miličević, R.; Klarić, I.

    2014-01-01

    The aim of this research was to investigate influence of different fermentation processes (by immobilized yeast cells and classical fermentation) and different cherry varieties (Maraska, Montmorencys and Kelleris) on the chemical and sensorial characteristics of cherry brandies. Cherry brandies were analyzed to determine chemical composition, aroma profile and sensory properties. Cherry brandies produced by immobilized yeast cells had a higher content of aldehydes, but lower content of total ...

  9. IMMOBILIZATION OF Saccharomyces Cerevisiae USING POLY(ACRYLAMIDE) GEL FOR ASYMMETRIC SYNTHESIS OF R(-)-MANDELIC ACID

    Institute of Scientific and Technical Information of China (English)

    LI Zhongqin; GUO Daiping; HUANG Xinghua; YANG Kai; XU Xiaoping

    2006-01-01

    In this paper, the poly(acrylamide) hydrogel used to immobilize saccharomyces cerevisiae for asymmetric synthesis of R(-)-mandelic acid was prepared with free radical ploymerization in deionized water at room temperature under nitrogen atmosphere. The influence of the composition of hydrogel, loading amount of cells and culture conditions on the asymmetric synthesis was investigated. Results show that PAAm hydrogel is a feasible carrier for immobilization of cells which is a potential alternative method to prepare enantiomerically pure R(-)-mandelic acid.

  10. Plutonium immobilization feed batching system concept report

    International Nuclear Information System (INIS)

    The Plutonium Immobilization Facility will encapsulate plutonium in ceramic pucks and seal the pucks inside welded cans. Remote equipment will place these cans in magazines and the magazines in a Defense Waste Processing Facility (DWPF) canister. The DWPF will fill the canister with high level waste glass for permanent storage. Feed batching is one of the first process steps involved with first stage plutonium immobilization. It will blend plutonium oxide powder before it is combined with other materials to make pucks. This report discusses the Plutonium Immobilization feed batching process preliminary concept, batch splitting concepts, and includes a process block diagram, concept descriptions, a preliminary equipment list, and feed batching development areas

  11. OPTIMIZATION OF ALKALINE PROTEASE PRODUCTION BY STREPTOMYCES AMBOFACIENS IN FREE AND IMMOBILIZED FORM

    Directory of Open Access Journals (Sweden)

    Nayera A.M. Abdelwahed

    2014-01-01

    Full Text Available Optimization of alkaline protease production by Streptomyces ambofaciens NRRL 2420 in free and immobilized form was investigated using submerged fermentation technique. The optimum conditions for maximum alkaline protease production 342 unit mL-1 were 30°C at pH 8.5 and incubation time 96 h in free cell cultures using starch 20 g L-1 as carbon source and yeast extract 5 g L-1 as nitrogen source. The incubation time for the best yield of 344 unit mL-1 was reduced to 72 h under the optimized fermentation conditions by immobilized cells adsorbed on synthetic cotton fibers. Data obtained during 5 reusable cycles showed higher levels of enzyme in shorter time duration. Immobilization of Streptomyces ambofaciens NRRL 2420 on synthetic cotton fiber permit repeated reuse of the cells under the optimized fermentation conditions.

  12. Phosphopeptide Enrichment by Immobilized Metal Affinity Chromatography.

    Science.gov (United States)

    Thingholm, Tine E; Larsen, Martin R

    2016-01-01

    Immobilized metal affinity chromatography (IMAC) has been the method of choice for phosphopeptide enrichment prior to mass spectrometric analysis for many years and it is still used extensively in many laboratories. Using the affinity of negatively charged phosphate groups towards positively charged metal ions such as Fe(3+), Ga(3+), Al(3+), Zr(4+), and Ti(4+) has made it possible to enrich phosphorylated peptides from peptide samples. However, the selectivity of most of the metal ions is limited, when working with highly complex samples, e.g., whole-cell extracts, resulting in contamination from nonspecific binding of non-phosphorylated peptides. This problem is mainly caused by highly acidic peptides that also share high binding affinity towards these metal ions. By lowering the pH of the loading buffer nonspecific binding can be reduced significantly, however with the risk of reducing specific binding capacity. After binding, the enriched phosphopeptides are released from the metal ions using alkaline buffers of pH 10-11, EDTA, or phosphate-containing buffers. Here we describe a protocol for IMAC using Fe(3+) for phosphopeptide enrichment. The principles are illustrated on a semi-complex peptide mixture. PMID:26584922

  13. Hyaluronan Immobilized Polyurethane as a Blood Contacting Material

    Directory of Open Access Journals (Sweden)

    Feirong Gong

    2010-01-01

    Full Text Available Hyaluronan (hyaluronic acid, HA was immobilized onto the surface of amino-functionalized polyurethane films with the goal of obtaining a novel kind of biomaterial which had the potential in blood-contacting applications. The amino-functionalized polyurethane was prepared by synthesized acidic polyurethane whose pendant carboxyl groups were treated with an excess amount of 1,3-diaminopropane in the presence of N,N-carbonyldiimidazole (CDI. Attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR, Raman spectroscopy (RS, scanning electron microscopy (SEM, and water contact angle measurement were used to confirm the surface changes at each step of treatment, both in morphologies and chemical compositions. APTT and PT results showed that HA immobilization could prolong the blood coagulation time, thus HA-immobilized polyurethane (PU-HA exhibited improved blood compatibility. Cytotoxicity analysis showed that the PU-HA films synthesized in this study were cytocompatible and could support human vein endothelial cells (HUVECs adhesion and proliferation.

  14. Immobilization of antibacterial chlorhexidine on stainless steel using crosslinking polydopamine film: Towards infection resistant medical devices.

    Science.gov (United States)

    Mohd Daud, Nurizzati; Saeful Bahri, Ihda Fithriyana; Nik Malek, Nik Ahmad Nizam; Hermawan, Hendra; Saidin, Syafiqah

    2016-09-01

    Chlorhexidine (CHX) is known for its high antibacterial substantivity and is suitable for use to bio-inert medical devices due to its long-term antibacterial efficacy. However, CHX molecules require a crosslinking film to be stably immobilized on bio-inert metal surfaces. Therefore, polydopamine (PDA) was utilized in this study to immobilize CHX on the surface of 316L type stainless steel (SS316L). The SS316L disks were pre-treated, modified with PDA film and immobilized with different concentrations of CHX (10mM-50mM). The disks were then subjected to various surface characterization analyses (ATR-FTIR, XPS, ToF-SIMS, SEM and contact angle measurement) and tested for their cytocompatibility with human skin fibroblast (HSF) cells and antibacterial activity against Escherichia coli and Staphylococcus aureus. The results demonstrated the formation of a thin PDA film on the SS316L surface, which acted as a crosslinking medium between the metal and CHX. CHX was immobilized via a reduction process that covalently linked the CHX molecules with the functional group of PDA. The immobilization of CHX increased the hydrophobicity of the disk surfaces. Despite this property, a low concentration of CHX optimized the viability of HSF cells without disrupting the morphology of adherent cells. The immobilized disks also demonstrated high antibacterial efficacy against both bacteria, even at a low concentration of CHX. This study demonstrates a strong beneficial effect of the crosslinked PDA film in immobilizing CHX on bio-inert metal, and these materials are applicable in medical devices. Specifically, the coating will restrain bacterial proliferation without suffocating nearby tissues. PMID:27153117

  15. Immobilization and stabilization of cyclodextrin glucanotransferase

    Czech Academy of Sciences Publication Activity Database

    Ivanova, V.; Šafaříková, Miroslava

    VII, - (2008), s. 80-83. ISSN N R&D Projects: GA MPO(CZ) 2A-1TP1/094 Institutional research plan: CEZ:AV0Z60870520 Keywords : cyclodextrin glucanotransferase * immobilization Subject RIV: CE - Biochemistry

  16. Immobilization of Rocky Flats Graphite Fines Residue

    International Nuclear Information System (INIS)

    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

  17. Immobilization of Bacillus sp. in mesoporous activated carbon for degradation of sulphonated phenolic compound in wastewater

    International Nuclear Information System (INIS)

    Xenobiotic compounds are used in considerable quantities in leather industries besides natural organic and inorganic compounds. These compounds resist biological degradation and thus they remain in the treated wastewater in the unaltered molecular configurations. Immobilization of organisms in carrier matrices protects them from shock load application and from the toxicity of chemicals in bulk liquid phase. Mesoporous activated carbon (MAC) has been considered in the present study as the carrier matrix for the immobilization of Bacillus sp. isolated from Effluent Treatment Plant (ETP) employed for the treatment of wastewater containing sulphonated phenolic (SP) compounds. Temperature, pH, concentration, particle size and mass of MAC were observed to influence the immobilization behavior of Bacillus sp. The percentage immobilization of Bacillus sp. was the maximum at pH 7.0, temperature 20 °C and at particle size 300 μm. Enthalpy, free energy and entropy of immobilization were − 46.9 kJ mol−1, − 1.19 kJ mol−1 and − 161.36 J K−1 mol−1 respectively at pH 7.0, temperature 20 °C and particle size 300 μm. Higher values of ΔH0 indicate the firm bonding of the Bacillus sp. in MAC. Degradation of aqueous sulphonated phenolic compound by Bacillus sp. immobilized in MAC followed pseudo first order rate kinetics with rate constant 1.12 × 10−2 min−1. Highlights: ► Degradation on phenolic syntan using immobilized activated carbon as catalyst. ► Bacillus sp. immobilized cell reactor removed all refractory organic loads. ► The removal mechanism is due to co-metabolism between carbon and organisms. ► The organics are completely metabolized rather than adsorption.

  18. Immobilization of Bacillus sp. in mesoporous activated carbon for degradation of sulphonated phenolic compound in wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Sekaran, G., E-mail: ganesansekaran@gmail.com [Environmental Technology Division, Council of Scientific and Industrial Research (CSIR), Central Leather Research Institute (CLRI), Adyar, Chennai-600 020 (India); Karthikeyan, S. [Environmental Technology Division, Council of Scientific and Industrial Research (CSIR), Central Leather Research Institute (CLRI), Adyar, Chennai-600 020 (India); Gupta, V.K. [Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee-247 667 (India); Department of Chemistry, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Boopathy, R.; Maharaja, P. [Environmental Technology Division, Council of Scientific and Industrial Research (CSIR), Central Leather Research Institute (CLRI), Adyar, Chennai-600 020 (India)

    2013-03-01

    Xenobiotic compounds are used in considerable quantities in leather industries besides natural organic and inorganic compounds. These compounds resist biological degradation and thus they remain in the treated wastewater in the unaltered molecular configurations. Immobilization of organisms in carrier matrices protects them from shock load application and from the toxicity of chemicals in bulk liquid phase. Mesoporous activated carbon (MAC) has been considered in the present study as the carrier matrix for the immobilization of Bacillus sp. isolated from Effluent Treatment Plant (ETP) employed for the treatment of wastewater containing sulphonated phenolic (SP) compounds. Temperature, pH, concentration, particle size and mass of MAC were observed to influence the immobilization behavior of Bacillus sp. The percentage immobilization of Bacillus sp. was the maximum at pH 7.0, temperature 20 Degree-Sign C and at particle size 300 {mu}m. Enthalpy, free energy and entropy of immobilization were - 46.9 kJ mol{sup -1}, - 1.19 kJ mol{sup -1} and - 161.36 J K{sup -1} mol{sup -1} respectively at pH 7.0, temperature 20 Degree-Sign C and particle size 300 {mu}m. Higher values of {Delta}H{sup 0} indicate the firm bonding of the Bacillus sp. in MAC. Degradation of aqueous sulphonated phenolic compound by Bacillus sp. immobilized in MAC followed pseudo first order rate kinetics with rate constant 1.12 Multiplication-Sign 10{sup -2} min{sup -1}. Highlights: Black-Right-Pointing-Pointer Degradation on phenolic syntan using immobilized activated carbon as catalyst. Black-Right-Pointing-Pointer Bacillus sp. immobilized cell reactor removed all refractory organic loads. Black-Right-Pointing-Pointer The removal mechanism is due to co-metabolism between carbon and organisms. Black-Right-Pointing-Pointer The organics are completely metabolized rather than adsorption.

  19. Biodegradation of phenol by free and immobilized Acinetobacter sp.strain PD12

    Institute of Scientific and Technical Information of China (English)

    WANG Ying; TIAN Ye; HAN Bin; ZHAO Hua-bing; BI Jian-nan; CAI Bao-li

    2007-01-01

    A new phenol-degrading bacterium with high biodegradation activity and high tolerance of phenol, strain PD 12, was isolated from the activated sludge of Tianjin Jizhuangzi Wastewater Treatment Facility in China. This strain was capable of removing 500 mg phenol/L in liquid minimal medium by 99.6% within 9 h and metabolizing phenol at concentrations up to 1100 mg/L. DNA sequencing and homologous analysis of 16S rRNA gene identified PD12 to be an Acinetobacter sp. Polyvinyl alcohol (PVA) was used as a gel matrix to immobilize Acinetobacter sp. strain PD12 by repeated freezing and thawing. The factors affecting phenol degradation of immobilized cells were investigated, and the results showed that the immobilized cells could tolerate a high phenol level and protected the bacteria against changes in temperature and pH. Storage stability and reusability tests revealed that the phenol degradation functions of immobilized cells were stable after reuse for 50 times or storing at 4℃ for 50 d. These results indicate that immobilized Acinetobacter sp. strain PD 12 possesses a good application potential in the treatment of phenol-containing wastewater.

  20. 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.

  1. Immobilization of Fast Reactor First Cycle Raffinate

    International Nuclear Information System (INIS)

    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

  2. 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.

  3. Characterization and optimization of hydrogen production by a salt water blue-green alga Oscillatoria sp. Miami BG 7. II - Use of immobilization for enhancement of hydrogen production

    Science.gov (United States)

    Phlips, E. J.; Mitsui, A.

    1986-01-01

    The technique of cellular immobilization was applied to the process of hydrogen photoproduction of nonheterocystous, filamentous marine blue-green alga, Oscillatoria sp. Miami BG 7. Immobilization with agar significantly improved the rate and longevity of hydrogen production, compared to free cell suspensions. Rates of H2 production in excess of 13 microliters H2 mg dry/wt h were observed and hydrogen production was sustained for three weeks. Immobilization also provided some stabilization to environmental variability and was adaptable to outdoor light conditions. In general, immobilization provides significant advantages for the production and maintenance of hydrogen photoproduction for this strain.

  4. Hyperalgesia in an immobilized rat hindlimb: effect of treadmill exercise using non-immobilized limbs.

    Science.gov (United States)

    Chuganji, Sayaka; Nakano, Jiro; Sekino, Yuki; Hamaue, Yohei; Sakamoto, Junya; Okita, Minoru

    2015-01-01

    Cast immobilization of limbs causes hyperalgesia, which is a decline of the threshold of mechanical and thermal mechanical stimuli. The immobilization-induced hyperalgesia (IIH) can disturb rehabilitation and activities of daily living in patients with orthopedic disorders. However, it is unclear what therapeutic and preventive approaches can be used to alleviate IIH. Exercise that activates the descending pain modulatory system may be effective for IIH. The purpose of this study was to investigate the effects of treadmill exercise during the immobilization period, using the non-immobilized limbs, on IIH. Thirty-six 8-week-old Wistar rats were randomly divided into (1) control, (2) immobilization (Im), and (3) immobilization and treadmill exercise (Im+Ex) groups. In the Im and Im+Ex groups, the right ankle joints of each rat were immobilized in full plantar flexion with a plaster cast for an 8-week period. In the Im+Ex group, treadmill exercise (15 m/min, 30 min/day, 5 days/week) was administered during the immobilization period while the right hindlimb was kept immobilized. Mechanical hyperalgesia was measured using von Frey filaments every week. To investigate possible activation of the descending pain modulatory system, beta-endorphin expression levels in hypothalamus and midbrain periaqueductal gray were analyzed. Although IIH clearly occurred in the Im group, the hyperalgesia was partially but significantly reduced in the Im+Ex group. Beta-endorphin, which is one of the endogenous opioids, was selectively increased in the hypothalamus and midbrain periaqueductal gray of the Im+Ex group. Our data suggest that treadmill running using the non-immobilized limbs reduces the amount of hyperalgesia induced in the immobilized limb even if it is not freed. This ameliorating effect might be due to the descending pain modulatory system being activated by upregulation of beta-endorphin in the brain. PMID:25304541

  5. Brain plasticity of rats exposed to prenatal immobilization stress

    Directory of Open Access Journals (Sweden)

    Badalyan B. Yu.

    2011-10-01

    Full Text Available Aim. This histochemical and immunohistochemical study was aimed at examining the brain cellular structures of newborn rats exposed to prenatal immobilization (IMO stress. Methods. Histochemical method on detection of Ca2+-dependent acid phosphatase activity and ABC immunohistochemical technique. Results. Cell structures with radial astrocytes marker GFAP, neuroepithelial stem cell marker gene nestin, stem-cells marker and the hypothalamic neuroprotective proline-rich polypeptide PRP-1 (Galarmin, a natural cytokine of a common precursor to neurophysin vasopressin associated glycoprotein have been revealed in several brain regions. Conclusions. Our findings indicate the process of generation of new neurons in response to IMO and PRP-1 involvement in this recovery mechanism, as PRP-1-Ir was detected in the above mentioned cell structures, as well as in the neurons and nerve fibers.

  6. Immobilization of epidermal growth factor on titanium and stainless steel surfaces via dopamine treatment

    International Nuclear Information System (INIS)

    Titanium and stainless steel were modified with dopamine for the immobilization of biomolecules, epidermal growth factor (EGF). First, the treatment of metal surfaces with a dopamine solution under different pH conditions was investigated. At higher pH, the dopamine solution turned brown and formed precipitates. Treatment of the metals with dopamine at pH 8.5 also resulted in the development of brown color at the surface of the metals. The hydrophobicity of the surfaces increased after treatment with dopamine, independently of pH. X-ray photoelectron spectroscopy revealed the formation of a significant amount of an organic layer on both surfaces at pH 8.5. According to ellipsometry measurements, the organic layer formed at pH 8.5 was about 1000 times as thick as that formed at pH 4.5. The amount of amino groups in the layer formed at pH 8.5 was also higher than that observed in the layer formed at pH 4.5. EGF molecules were immobilized onto the dopamine-treated surfaces via a coupling reaction using carbodiimide. A greater amount of EGF was immobilized on surfaces treated at pH 8.5 compared with pH 4.5. Significantly higher growth of rat fibroblast cells was observed on the two EGF-immobilized surfaces compared with non-immobilized surfaces in the presence of EGF. The present study demonstrated that metals can become bioactive via the surface immobilization of a growth factor and that the effect of the immobilized growth factor on metals was greater than that of soluble growth factor. - Highlights: ► Epidermal growth factor was covalently immobilized on titan or stainless steel surfaces. ► Amino groups were formed on the surfaces by the treatment and the growth factor was immobilized through amide bonds. ► The immobilized epidermal growth factor accelerated cell proliferation more than soluble ones on the surfaces.

  7. Bioethanol production by reusable Saccharomyces cerevisiae immobilized in a macroporous monolithic hydrogel matrices.

    Science.gov (United States)

    Mulko, Lucinda; Rivarola, Claudia R; Barbero, Cesar A; Acevedo, Diego F

    2016-09-10

    Performance of yeasts on industrial processes can be dramatically improved by immobilization of the biocatalyst. The immobilization of Saccharomyces cerevisiae inside monolithic macroporous hydrogels were produced by in-situ polymerization of acrylamide around a live yeast suspension under cryogelation conditions. Preculture of the yeasts was not necessary and this innovative and simple procedure is amenable to scaling-up to industrial production. The yeasts were efficiently retained in monolithic hydrogels, presenting excellent mechanical properties and high cell viability. Macroporous hydrogels showed a fast mass transport allowing the hydrogel-yeast complexes achieved similar ethanol yield and productivity than free yeasts, which is larger than those reached with yeasts immobilized in compact hydrogels. Moreover, the same yeasts were able to maintain its activity by up to five reaction cycles with a cell single batch during fermentation reactions. PMID:27396938

  8. Improved enzyme immobilization for enhanced bioelectrocatalytic activity of porous electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Szamocki, Rafael [University Bordeaux 1, CNRS, ISM, Ecole Nationale Superieur de Chimie et Physique de Bordeaux, 16 Avenue Pey Berland, 33607 Pessac (France); Department of Physical Chemistry, Universitaet des Saarlandes, 66123 Saarbruecken (Germany); Velichko, Alexandra; Muecklich, Frank [Department of Material Science, Universitaet des Saarlandes, 66123 Saarbruecken (Germany); Reculusa, Stephane; Ravaine, Serge [Centre de Recherche Paul Pascal-CRPP, 115 Avenue du Dr. Schweitzer, 33600 Pessac (France); Neugebauer, Sebastian; Schuhmann, Wolfgang [Department of Analytical Chemistry, Ruhr-Universitaet Bochum, Universitaetsstr. 150, 44780 Bochum (Germany); Hempelmann, Rolf [Department of Physical Chemistry, Universitaet des Saarlandes, 66123 Saarbruecken (Germany); Kuhn, Alexander [University Bordeaux 1, CNRS, ISM, Ecole Nationale Superieur de Chimie et Physique de Bordeaux, 16 Avenue Pey Berland, 33607 Pessac (France)

    2007-08-15

    Porous electrodes with increased surface area have been prepared using a template route via colloidal crystals. The ordered porous structure and the interconnections between the pores have been quantitatively characterized by Focused Ion Beam Tomography. The internal surfaces of the electrodes have been biofunctionalized with two enzymatic systems for glucose oxidation. In order to increase significantly the stability, the biocatalysts have been immobilized either by crosslinking or by incorporation in an electrodeposition paint. The modified porous electrodes show an increased overall signal and therefore a better detection limit and a higher sensitivity when used as sensors, and a potentially higher power output when employed in biofuel cells. (author)

  9. Phase composition of murataite ceramics for excess weapons plutonium immobilization

    Science.gov (United States)

    Sobolev, I. A.; Stefanovsky, S. V.; Myasoedov, B. F.; Kullako, Y. M.; Yudintsev, S. V.

    2000-07-01

    Among the host phases for actinides immobilization, murataite (cubic, space group Fm3m) with the general formula A4B2C7O22-x (A=Ca, Mn, Na, Ln, An; B=Mn, Ti, Zr, AnIV; C=Ti, Al, Fe; 0ceramics in detail has shown occurrence of several murataite varieties with three-, five-, and eight-fold fluorite unit cells. [1-3] The goal of the present step of work is to study an effect of waste elements on phase composition of murataite ceramic and isomorphic capacity of waste elements.

  10. Mineral induction by immobilized phosphoproteins

    Science.gov (United States)

    Saito, T.; Arsenault, A. L.; Yamauchi, M.; Kuboki, Y.; Crenshaw, M. A.

    1997-01-01

    Dentin phosphoproteins are thought to have a primary role in the deposition of mineral on the collagen of dentin. In this study we determined the type of binding between collagen and phosphoproteins necessary for mineral formation onto collagen fibrils and whether the phosphate esters are required. Bovine dentin phosphophoryn or phosvitin from egg yolk were immobilized on reconstituted skin type I collagen fibrils by adsorption or by covalent cross-linking. In some samples the ester phosphate was removed from the covalently cross-linked phosphoproteins by treatment with acid phosphatase. All samples were incubated at 37 degrees C in metastable solutions that do not spontaneously precipitate. Reconstituted collagen fibrils alone did not induce mineral formation. The phosphoproteins adsorbed to the collagen fibrils desorbed when the mineralization medium was added, and mineral was not induced. The mineral induced by the cross-linked phosphoproteins was apatite, and the crystals were confined to the surface of the collagen fibrils. With decreasing medium saturation the time required for mineral induction increased. The interfacial tensions calculated for apatite formation by either phosphoprotein cross-linked to collagen were about the same as that for phosphatidic acid liposomes and hydroxyapatite. This similarity in values indicates that the nucleation potential of these highly phosphorylated surfaces is about the same. It is concluded that phosphoproteins must be irreversibly bound to collagen fibrils for the mineralization of the collagen network in solutions that do not spontaneously precipitate. The phosphate esters of phosphoproteins are required for mineral induction, and the carboxylate groups are not sufficient.

  11. Comparison of alcoholic fermentation performance of the free and immobilized yeast on water hyacinth stem pieces in medium with different glucose contents.

    Science.gov (United States)

    Tran, Van Nguyen; Le, Van Viet Man

    2014-01-01

    Ethanol fermentation with Saccharomyces cerevisiae cells was performed in medium with different glucose concentrations. As the glucose content augmented from 200 to 250 g/L, the growth of the immobilized cells did not change while that of the free cells was reduced. At higher glucose concentration (300, 350, and 400 g/L), the cell proliferation significantly decreased and the residual sugar level sharply augmented for both the immobilized and free yeast. The specific growth rate of the immobilized cells was 27–65 % higher than that of the free cells, and the final ethanol concentration in the immobilized yeast cultures was 9.7–18.5 % higher than that in the free yeast cultures. However, the immobilized yeast demonstrated similar or slightly lower ethanol yield in comparison with the free yeast. High fermentation rate of the immobilized yeast was associated with low unsaturation degree of fatty acids in cellular membrane. Adsorption of S. cerevisiae cells on water hyacinth stem pieces in the nutritional medium decreased the unsaturation degree of membrane lipid and the immobilized yeast always exhibited lower unsaturation degree of membrane lipid than the free yeast in ethanol fermentation. PMID:24122709

  12. Reversible thermal denaturation of immobilized rhodanese

    International Nuclear Information System (INIS)

    For the first time, the enzyme rhodanese had been refolded after thermal denaturation. This was previously not possible because of the strong tendency for the soluble enzyme to aggregate at temperatures above 37 degrees C. The present work used rhodanese that was covalently coupled to a solid support under conditions that were found to preserve enzyme activity. Rhodanese was immobilized using an N-hydroxymalonimidyl derivative of Sepharose containing a 6-carbon spacer. The number of immobilized competent active sites was measured by using [35S]SO3(2-) to form an active site persulfide that is the obligatory catalytic intermediate. Soluble enzyme was irreversibly inactivated in 10 min at 52 degrees C. The immobilized enzyme regained at least 30% of its original activity even after boiling for 20 min. The immobilized enzyme had a Km and Vmax that were each approximately 3 times higher than the corresponding values for the native enzyme. After preincubation at high temperatures, progress curves for the immobilized enzyme showed induction periods of up to 5 min before attaining apparently linear steady states. The pH dependence of the activity was the same for both the soluble and the immobilized enzyme. These results indicate significant stabilization of rhodanese after immobilization, and instabilities caused by adventitious solution components are not the sole reasons for irreversibility of thermal denaturation seen with the soluble enzyme. The results are consistent with models for rhodanese that invoke protein association as a major cause of inactivation of the enzyme. Furthermore, the induction period in the progress curves is consistent with studies which show that rhodanese refolding proceeds through intermediate states

  13. Uranium sorption by Pseudomonas biomass immobilized in radiation polymerized polyacrylamide bio-beads.

    Science.gov (United States)

    D'Souza, S F; Sar, Pinaki; Kazy, Sufia K; Kubal, B S

    2006-01-01

    A Pseudomonas strain identified as a potent biosorbent of uranium (U) and thorium was immobilized in radiation-induced polyacrylamide matrix for its application in radionuclide containing wastewater treatment. The immobilized biomass exhibited a high U sorption of 202 mg g(-1) dry wt. with its optimum at pH 5.0. A good fit of experimental data to the Freundlich model suggested multilayered uranium binding with an affinity distribution among biomass metal binding sites. Scanning electron microscopy revealed a highly porous nature of the radiation-polymerized beads with bacterial cells mostly entrapped on pore walls. Energy dispersive X-ray analysis (EDXA) coupled with SEM ascertained the accumulation of uranium by the immobilized biomass without any physical damage to the cells. A significant (90%) part of biosorbed uranium was recovered using sodium bicarbonate with the immobilized biomass maintaining their U resorption capacity for multiple sorption-desorption cycles. Uranium loading and elution behavior of immobilized biomass evaluated within a continuous up-flow packed bed columnar reactor showed its effectiveness in removing uranium from low concentration (50 mg U L(-1)) followed by its recovery resulting in a 4-5-fold waste volume reduction. The data suggested the suitability of radiation polymerization in obtaining bacterial beads for metal removal and also the potential of Pseudomonas biomass in treatment of radionuclide containing waste streams. PMID:16484078

  14. Polishing of POME by Chlorella sp. in suspended and immobilized system

    Science.gov (United States)

    Lahin, F. A.; Sarbatly, R.; Suali, E.

    2016-06-01

    The effect of using suspended and immobilized growth of Chlorella sp. to treat POME was studied. Cotton and nylon ropes were used as the immobilization material in a rotating microalgae biofilm reactor. The result showed that POME treated in suspended growth system was able to remove 81.9% and 55.5% of the total nitrogen (TN) and total phosphorus (TP) respectively. Whereas the immobilized system showed lower removal of 77.22% and 53.02% for TN and TP. Lower performance of immobilized microalgae is due to the limited light penetration and supply of CO2 inside the immobilization materials. The rotating microalgae biofilm reactor was able to reduce the biochemical oxygen demand (BOD) to 90 mg/L and chemical oxygen demand (COD) to 720 mg/L. Higher BOD and COD reading were obtained in suspended growth due to the presence of small number of microalgae cell in the samples. This study shows that suspended growth system is able to remove higher percentages of nitrogen and phosphorus. However, an efficient separation method such as membrane filtration is required to harvest the cultivated microalgae cell to avoid organic matter release into water bodies.

  15. Biodegradation of Crude Oil in Contaminated Soils by Free and Immobilized Microorganisms

    Institute of Scientific and Technical Information of China (English)

    WANG Zhen-Yu; XU Ying; WANG Hao-Yun; ZHAO Jian; GAO Dong-Mei; LI Feng-Min; B. XING

    2012-01-01

    The efficiencies of free and immobilized bacterial cultures of petroleum hydrocarbon degraders were evaluated and compared in this study.Hydrocarbon-degrading microbial communities with high tolerance to and high degrading ability of crude oil were obtained from the soil contaminated with crude oil in the Yellow River Delta.Then,the microbial ceils were immobilized in sodium alginate (SA) beads and sodium alginate-diatomite (SAD) beads.The biodegradation of crude oil in soil by immobilized cells was compared with that by free cells at three inocuIation concentrations,1 × 104 colony forming units (cfu) kg-1 (low concentration,L),5 × 104 cfu kg-1 (medium concentration,M),and 1 × 105 cfu kg -1 (high concentration,H).At 20 d after inoculation,the maximum degradation rate in the immobilized systems reached 29.8% (SAD-M),significantly higher (P < 0.05) than that of the free cells (21.1%),and the SAD beads showed greater degradation than the SA beads.Moreover,both microbial populations and total microbial activity reached significantly higher level (P < 0.05) in the immobilized systems than free cell systems at a same initial inoculation amount.The scanning electronic microscope (SEM) images also confirmed the advantages of the immobilized microstructure of SAD beads.The enhanced degradation and bacterial growth in the SAD beads indicated the high potential of SAD beads as an effective option for bioremediation of crude oil-contaminated soils in the Yellow River Delta.

  16. 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.

  17. Decolorization of azo dyes with Enterobacter agglomerans immobilized in different supports by using fluidized bed bioreactor.

    Science.gov (United States)

    Moutaouakkil, Adnane; Zeroual, Youssef; Dzayri, Fatima Zohra; Talbi, Mohamed; Lee, Kangmin; Blaghen, Mohamed

    2004-02-01

    Immobilized cells of Enterobacter agglomerans, able to reduce azo dyes enzymatically, were used as a biocatalyst for the decolorization of synthetic medium containing the toxic azo dye methyl red (MR). This bacterial strain exhibits high ability to completely decolorize 100 mg/L of MR after only 6 h of incubation under aerobic conditions. Cells of E. agglomerans were immobilized in calcium alginate, polyacylamide, cooper beech, and vermiculite, and were used for the decolorization of MR from synthetic water by using a fluidized bed bioreactor. The highest specific decolorization rate was obtained when E. agglomerans was entrapped in calcium alginate beads and was of about 3.04 mg MR/g cell/h with a 50% conversion time ( t(1/2)) of about 1.6 h. Moreover, immobilized cells in calcium alginate continuously decolorized MR even after seven repeated experiments without significant loss of activity, while polyacrylamide-, cooper beech-, and vermiculite-immobilized cells retained only 62, 15, and 13% of their original activity, respectively. PMID:15057480

  18. Immobilization of Ochrobactrum tritici As5 on PTFE thin films for arsenite biofiltration.

    Science.gov (United States)

    Branco, Rita; Sousa, Tânia; Piedade, Ana P; Morais, Paula V

    2016-03-01

    Ochrobactrum tritici SCII24T bacteria is an environmental strain with high capacity to resist to arsenic (As) toxicity, which makes it able to grow in the presence of As(III). The inactivation of the two functional arsenite efflux pumps, ArsB and ACR3_1, resulted in the mutant O. tritici As5 exhibiting a high accumulation of arsenite. This work describes a method for the immobilization of the mutant cells O. tritici As5, on a commercial polymeric net after sputtered modified by the deposition of poly(tetrafluoroethylene) (PTFE) thin films, and demonstrates the capacity of immobilized cells to accumulate arsenic from solutions. Six different set of deposition parameters for PTFE thin films were developed and tested in vitro regarding their ability to immobilize the bacterial cells. The surface that exhibited a mild zeta potential value, hydrophobic characteristics, the lowest surface free energy but with a high polar component and the appropriate ratio of chemical reactive groups allowed cells to proliferate and to grow as a biofilm. These immobilized cells maintained their ability to accumulate the surrounding arsenite, making it a great arsenic biofilter to be used in bioremediation processes. PMID:26735734

  19. 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

  20. Accumulation of uranium by immobilized persimmon tannin

    International Nuclear Information System (INIS)

    We have discovered that the extracted juice of unripe astringent persimmon fruit, designated as kakishibu or shibuol, has an extremely high affinity for uranium. To develop efficient adsorbents for uranium, we tried to immobilize kakishibu (persimmon tannin) with various aldehydes and mineral acids. Persimmon tannin immobilized with glutaraldehyde can accumulate 1.71 g (14 mEq U) of uranium per gram of the adsorbent. The uranium accumulating capacity of this adsorbent is several times greater than that of commercially available chelating resins (2-3 mEq/g). Immobilized persimmon tannin has the most favorable features for uranium recovery; high selective adsorption ability, rapid adsorption rate, and applicability in both column and batch systems. The uranium retained on immobilized persimmon tannin can be quantitatively and easily eluted with a very dilute acid, and the adsorbent can thus be easily recycled in the adsorption-desorption process. Immobilized persimmon tannin also has a high affinity for thorium. 23 refs., 13 figs., 7 tabs

  1. Immobilization of Methyltrioxorhenium on Mesoporous Aluminosilicate Materials

    Directory of Open Access Journals (Sweden)

    Martina Stekrova

    2014-03-01

    Full Text Available The presented report focuses on an in-depth detailed characterization of immobilized methyltrioxorhenium (MTO, giving catalysts with a wide spectra of utilization. The range of mesoporous materials with different SiO2/Al2O3 ratios, namely mesoporous alumina (MA, aluminosilicates type Siral (with Al content 60%–90% and MCM-41, were used as supports for immobilization of MTO. The tested support materials (aluminous/siliceous exhibited high surface area, well-defined regular structure and narrow pore size distribution of mesopores, and therefore represent excellent supports for the active components. Some of the supports were modified by zinc chloride in order to obtain catalysts with higher activities for instance in metathesis reactions. The immobilization of MTO was optimized using these supports and it was successful using all supports. The success of the immobilization of MTO and the properties of the prepared heterogeneous catalysts were characterized using X-ray Fluorescence (XRF, atomic absorption spectroscopy (AAS, X-ray powder diffraction (XRD, scanning electron microscopy (SEM, physical adsorption of N2, ultraviolet-visible spectroscopy (UV-Vis, infrared spectroscopy (FTIR, Fourier Transform Infrared Spectroscopy (FTIR using pyridine as a probe molecule and X-ray photoelectron spectroscopy (XPS. Furthermore, the catalytic activity of the immobilized MTO on the tested supports was demonstrated on metathesis reactions of various substrates.

  2. Plasmid stability in immobilized and free recombinant Escherichia coli JM105(pKK223-200): importance of oxygen diffusion, growth rate, and plasmid copy number.

    OpenAIRE

    de Taxis du Poët, P; Arcand, Y; Bernier, R.; Barbotin, J N; Thomas, D.

    1987-01-01

    Stability of the plasmid pKK223-200 in Escherichia coli JM105 was studied for both free and immobilized cells during continuous culture. The relationship between plasmid copy number, xylanase activity, which was coded for by the plasmid, and growth rate and culture conditions involved complex interactions which determined the plasmid stability. Generally, the plasmid stability was enhanced in cultured immobilized cells compared with free-cell cultures. This stability was associated with modif...

  3. Airlift bioreactor containing chitosan-immobilized Sphingobium sp. P2 for treatment of lubricants in wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Khondee, Nichakorn; Tathong, Sitti [International Postgraduate Programs in Environmental Management, Graduate School, Chulalongkorn University, Bangkok (Thailand); Bioremediation Research Unit, Department of Microbiology, Faculty of Science, Chulalongkorn University, Bangkok (Thailand); Pinyakong, Onruthai [Bioremediation Research Unit, Department of Microbiology, Faculty of Science, Chulalongkorn University, Bangkok (Thailand); National Center of Excellence for Environmental and Hazardous Waste Management (NCE-EHWM), Chulalongkorn University, Bangkok (Thailand); Powtongsook, Sorawit [Center of Excellence for Marine Biotechnology (c/o Department of Marine Science, Chulalongkorn University), National Center for Genetic Engineering and Biotechnology, Pathum Thani (Thailand); Chatchupong, Thawach; Ruangchainikom, Chalermchai [Environmental Research and Management Department, PTT Research and Technology Institute, Ayutthaya (Thailand); Luepromchai, Ekawan, E-mail: ekawan.l@chula.ac.th [Bioremediation Research Unit, Department of Microbiology, Faculty of Science, Chulalongkorn University, Bangkok (Thailand); National Center of Excellence for Environmental and Hazardous Waste Management (NCE-EHWM), Chulalongkorn University, Bangkok (Thailand)

    2012-04-30

    Highlights: Black-Right-Pointing-Pointer Sphingobium sp. P2 effectively degraded various lubricant samples. Black-Right-Pointing-Pointer Efficiency of Sphingobium sp. P2 increased after immobilization on chitosan. Black-Right-Pointing-Pointer High removal efficiency was due to both sorption and degradation processes. Black-Right-Pointing-Pointer The immobilized bacteria (4 g L{sup -1}) were applied in internal loop airlift bioreactor. Black-Right-Pointing-Pointer The bioreactor continuously removed lubricant from emulsified wastewater. - Abstract: An internal loop airlift bioreactor containing chitosan-immobilized Sphingobium sp. P2 was applied for the removal of automotive lubricants from emulsified wastewater. The chitosan-immobilized bacteria had higher lubricant removal efficiency than free and killed-immobilized cells because they were able to sorp and degrade the lubricants simultaneously. In a semi-continuous batch experiment, the immobilized bacteria were able to remove 80-90% of the 200 mg L{sup -1} total petroleum hydrocarbons (TPH) from both synthetic and carwash wastewater. The internal loop airlift bioreactor, containing 4 g L{sup -1} immobilized bacteria, was later designed and operated at 2.0 h HRT (hydraulic retention time) for over 70 days. At a steady state, the reactor continuously removed 85 {+-} 5% TPH and 73 {+-} 11% chemical oxygen demand (COD) from the carwash wastewater with 25-200 mg L{sup -1} amended lubricant. The internal loop airlift reactor's simple operation and high stability demonstrate its high potential for use in treating lubricants in emulsified wastewater from carwashes and other industries.

  4. [Water binding of adsorptive immobilized lipases].

    Science.gov (United States)

    Loose, S; Meusel, D; Muschter, A; Ruthe, B

    1990-01-01

    It is supposed that not only the total water content of lipase preparations but more their state of water binding is of technological importance in enzymatic interesterification reactions in systems nearly free from water. The isotherms at 65 degrees C of two microbial lipases immobilized on various adsorbents as well as different adsorbents themselves are shown. The water binding capacity in the range of water content of technological interest decreases from the anion exchange resin Amberlyst A 21 via nonpolar adsorbent Amberlite XAD-2 to kieselguhr Celite 545. It is demonstrated that water binding by lipases is depending on temperature but is also affected by adsorptive immobilization. Adsorptive immobilized lipases show hysteresis, which is very important for preparing a definite water content of the enzyme preparations. PMID:2325750

  5. Characterization of bioactive RGD peptide immobilized onto poly(acrylic acid) thin films by plasma polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Hyun Suk; Ko, Yeong Mu; Shim, Jae Won [Department of Dental Materials, School of Dentistry, MRC Center, Chosun University, Gwangju (Korea, Republic of); Lim, Yun Kyong; Kook, Joong-Ki [Department of Oral Biochemistry, School of Dentistry, Chosun University, Gwangju (Korea, Republic of); Cho, Dong-Lyun [School of Applied Chemical Engineering and Center for Functional Nano Fine Chemicals, Chonnam National University, Gwangju (Korea, Republic of); Kim, Byung Hoon, E-mail: kim5055@chosun.ac.kr [Department of Dental Materials, School of Dentistry, MRC Center, Chosun University, Gwangju (Korea, Republic of)

    2010-11-01

    Plasma surface modification can be used to improve the surface properties of commercial pure Ti by creating functional groups to produce bioactive materials with different surface topography. In this study, a titanium surface was modified with acrylic acid (AA) using a plasma treatment and immobilized with bioactive arginine-glycine-aspartic acid (RGD) peptide, which may accelerate the tissue integration of bone implants. Both terminals containing the -NH{sub 2} of RGD peptide sequence and -COOH of poly(acrylic acid) (PAA) thin film were combined with a covalent bond in the presence of 1-ethyl-3-3-dimethylaminopropyl carbodiimide (EDC). The chemical structure and morphology of AA film and RGD immobilized surface were investigated by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR), atomic force microscopy (AFM), and scanning electron microscopy (SEM). All chemical analysis showed full coverage of the Ti substrate with the PAA thin film containing COOH groups and the RGD peptide. The MC3T3-E1 cells were cultured on each specimen, and the cell alkaline phosphatase (ALP) activity were examined. The surface-immobilized RGD peptide has a significantly increased the ALP activity of MC3T3-E1 cells. These results suggest that the RGD peptide immobilization on the titanium surface has an effect on osteoblastic differentiation of MC3T3-E1 cells and potential use in osteo-conductive bone implants.

  6. Characterization of bioactive RGD peptide immobilized onto poly(acrylic acid) thin films by plasma polymerization

    International Nuclear Information System (INIS)

    Plasma surface modification can be used to improve the surface properties of commercial pure Ti by creating functional groups to produce bioactive materials with different surface topography. In this study, a titanium surface was modified with acrylic acid (AA) using a plasma treatment and immobilized with bioactive arginine-glycine-aspartic acid (RGD) peptide, which may accelerate the tissue integration of bone implants. Both terminals containing the -NH2 of RGD peptide sequence and -COOH of poly(acrylic acid) (PAA) thin film were combined with a covalent bond in the presence of 1-ethyl-3-3-dimethylaminopropyl carbodiimide (EDC). The chemical structure and morphology of AA film and RGD immobilized surface were investigated by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR), atomic force microscopy (AFM), and scanning electron microscopy (SEM). All chemical analysis showed full coverage of the Ti substrate with the PAA thin film containing COOH groups and the RGD peptide. The MC3T3-E1 cells were cultured on each specimen, and the cell alkaline phosphatase (ALP) activity were examined. The surface-immobilized RGD peptide has a significantly increased the ALP activity of MC3T3-E1 cells. These results suggest that the RGD peptide immobilization on the titanium surface has an effect on osteoblastic differentiation of MC3T3-E1 cells and potential use in osteo-conductive bone implants.

  7. Cobalt immobilization by manganese oxidizing bacteria from the Indian ridge system

    Digital Repository Service at National Institute of Oceanography (India)

    Antony, R.; Sujith, P.P.; Fernandes, S.O.; Verma, P.; Khedekar, V.D.; LokaBharathi, P.A.

    requirement of Mn is more than Co. Thus, these differences in the immobilization of the two metals could be driven by the differences in the requirement, cell physiology and the affinities of the isolates for the concentrations of the metals tested...

  8. Characterization of bioactive RGD peptide immobilized onto poly(acrylic acid) thin films by plasma polymerization

    Science.gov (United States)

    Seo, Hyun Suk; Ko, Yeong Mu; Shim, Jae Won; Lim, Yun Kyong; Kook, Joong-Ki; Cho, Dong-Lyun; Kim, Byung Hoon

    2010-11-01

    Plasma surface modification can be used to improve the surface properties of commercial pure Ti by creating functional groups to produce bioactive materials with different surface topography. In this study, a titanium surface was modified with acrylic acid (AA) using a plasma treatment and immobilized with bioactive arginine-glycine-aspartic acid (RGD) peptide, which may accelerate the tissue integration of bone implants. Both terminals containing the -NH2 of RGD peptide sequence and -COOH of poly(acrylic acid) (PAA) thin film were combined with a covalent bond in the presence of 1-ethyl-3-3-dimethylaminopropyl carbodiimide (EDC). The chemical structure and morphology of AA film and RGD immobilized surface were investigated by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR), atomic force microscopy (AFM), and scanning electron microscopy (SEM). All chemical analysis showed full coverage of the Ti substrate with the PAA thin film containing COOH groups and the RGD peptide. The MC3T3-E1 cells were cultured on each specimen, and the cell alkaline phosphatase (ALP) activity were examined. The surface-immobilized RGD peptide has a significantly increased the ALP activity of MC3T3-E1 cells. These results suggest that the RGD peptide immobilization on the titanium surface has an effect on osteoblastic differentiation of MC3T3-E1 cells and potential use in osteo-conductive bone implants.

  9. Immobilization of two organometallic complexes into a single cage to construct protein-based microcompartments.

    Science.gov (United States)

    Maity, Basudev; Fukumori, Kazuki; Abe, Satoshi; Ueno, Takafumi

    2016-04-01

    Natural protein-based microcompartments containing multiple enzymes promote cascade reactions within cells. We use the apo-ferritin protein cage to mimic such biocompartments by immobilizing two organometallic Ir and Pd complexes into the single protein cage. Precise locations of the metals and their accumulation mechanism were studied by X-ray crystallography. PMID:27021005

  10. Immobilization of enzymes onto carbon nanotubes

    Directory of Open Access Journals (Sweden)

    Prlainović Nevena Ž.

    2011-01-01

    Full Text Available The discovery of carbon nanotubes (CNTs has opened a new door in nanotechnology. With their high surface area, unique electronic, thermal and mechanical properties, CNTs have been widely used as carriers for protein immobilization. In fact, carbon nanotubes present ideal support system without diffusional limitations, and also have the possibility of surface covalent functionalization. It is usually the oxidation process that introduces carboxylic acid groups. Enzymes and other proteins could be adsorbed or covalently attached onto carbon nanotubes. Adsorption of enzyme is a very simple and inexpensive immobilization method and there are no chemical changes of the protein. It has also been found that this technique does not alter structure and unique properties of nanotubes. However, a major problem in process designing is relatively low stability of immobilized protein and desorption from the carrier. On the other hand, while covalent immobilization provides durable attachment the oxidation process can reduce mechanical and electronic properties of carbon nanotubes. It can also affect the active site of enzyme and cause the loss of enzyme activity. Bioimmobilization studies have showed that there are strong interactions between carbon nanotubes surface and protein. The retention of enzyme structure and activity is critical for their application and it is of fundamental interest to understand the nature of these interactions. Atomic force microscopy (AFM, transmission electron microscopy (TEM, scanning electron microscopy (SEM and circular dichroism (CD spectroscopy provide an insight into the structural changes that occur during the immobilization. The aim of this paper is to summarize progress of protein immobilization onto carbon nanotubes.

  11. [Use of immobilization in the study of glyceraldehyde 3-phosphate dehydrogenase. Immobilized monomers].

    Science.gov (United States)

    Muronets, V I; Ashmarina, L I; Asriiants, R A; Nagradova, N K

    1982-06-01

    Active immobilized monomers of glyceraldehyde 3-phosphate dehydrogenase were prepared by means of dissociation of the tetrameric enzyme molecule covalently bound to Sepharose via a single subunit. The conditions were elaborated to achieve the inactivation and solubilization of the non-covalently bound subunits leaving the monomer coupled to the matrix intact. This procedure differs from the previously developed method of matrix-bound oligomeric enzymes dissociation in a detail which was found to be essentially important. The widely used method includes complete denaturation of all subunits during treatment with urea followed by reactivation of the immobilized one, whereas only the non-covalently bound subunits suffer denaturation under the conditions developed in the present work. The immobilized monomers of glyceraldehyde 3-phosphate dehydrogenase exhibit Vmax and Km (for NAD and substrate) values similar to those found for the immobilized tetramer. Reassociation of the immobilized monomers with soluble enzyme subunits obtained in the presence of urea produces matrix-bound tetrameric species. Immobilized trimers ae formed upon incubation of matrix-bound monomers in a diluted apoenzyme solution. The immobilized monomeric, trimeric and tetrameric enzyme species were used to study the role of subunit interactions in cooperative phenomena exhibited by the dehydrogenase. PMID:7115810

  12. Selection of support materials for immobilization of Burkholderia cepacia PCL3 in treatment of carbofuran-contaminated water.

    Science.gov (United States)

    Laocharoen, S; Plangklang, P; Reungsang, A

    2013-01-01

    This study investigated the utilization of agricultural matrices as the support materials for cell immobilization to improve the technique of bioremediation. Coir, bulrush, banana stem and water hyacinth stem in both delignified and undelignified forms were used to immobilize Burkholderia cepacia PCL3 in bioremediation of carbofuran at 5 mg l(-1) in synthetic wastewater. Undelignified coir was found to be the most suitable support material for cell immobilization, giving the short half-life of carbofuran of 3.40 d (2.8 times shorter than the treatments with free cells). In addition, it could be reused three times without a loss in ability to degrade carbofuran. The growth and degradation ability of free cells were completely inhibited at the initial carbofuran concentrations of 250 mg l(-1), while there was no inhibitory effect of carbofuran on the immobilized cells. The results indicated a great potential for using the agricultural matrices as support material for cell immobilization to improve the overall efficiency of carbofuran bioremediation in contaminated water by B. cepacia PCL3. PMID:24527620

  13. Cadmium biosorption by polyvinyl alcohol immobilized recombinant Escherichia coli

    International Nuclear Information System (INIS)

    Recombinant Escherichia coli expressing human metallothionein protein was immobilized with polyvinyl alcohol (PVA) for the removal of cadmium from solution. The adsorption ability was strongly affected by pH with optimal performance at pH 5.0, while it was less sensitive to temperature over the range of 20-42 deg. C. The adsorption kinetics and equilibrium of PVA-immobilized cells was best described by pseudo-second order model and Langmuir isotherm, respectively. Over the Cd concentrations range of 10-150 mg/l, PVA-cells had the highest Cd removal percentage (82.7%) at 10 mg Cd/l and a biomass loading of 15.4 wt.%. Better adsorption ability was obtained when biomass loading was increased, as the highest adsorption capacity of 4.29 mg/g was achieved at 33.0 wt.% of biomass (initial Cd concentration = 100 mg/l). An aqueous solution of 0.01 M Na3NTA displayed the best desorption efficiency (57-89%) for four A/D cycles, while 51-61% of the original adsorption capacity was retained after regeneration.

  14. Immobilized reactor for rapid destruction of recalcitrant organics and inorganics in tannery wastewater

    Institute of Scientific and Technical Information of China (English)

    A. Ganesh Kumar; G. Sekaran; S. Swarnalatha; B. Prasad Rao

    2005-01-01

    The wastewater discharged from tanneries lack biodegradability due to the presence of recalcitrant compounds at significant concentration. The focal theme of the present investigation was to use chemo-autotrophic activated carbon oxidation(CAACO) reactor, an immobilized cell reactor using chemoautotrophs for the treatment of tannery wastewater. The treatment scheme comprised of anaerobic treatment, sand filtration, and CAACO reactor, which remove COD, BOD, TOC, VFA and sulphides respectively by 86%, 95%, 81%,71% and 100%. Rice bran mesoporous activated carbon prepared indigenously and was used for immobilization of chemoautotrophs. The degradation of xenobiotic compounds by CAACO was confirmed through HPLC and FT-IR techniques.

  15. Decolorization and partial mineralization of a polyazo dye by Bacillus firmus immobilized within tubular polymeric gel

    OpenAIRE

    Ogugbue, Chimezie Jason; Morad, Norhashimah; Sawidis, Thomas; Oranusi, Nathaniel A.

    2011-01-01

    The degradation of C.I. Direct red 80, a polyazo dye, was investigated using Bacillus firmus immobilized by entrapment in tubular polymeric gel. This bacterial strain was able to completely decolorize 50 mg/L of C.I. Direct red 80 under anoxic conditions within 12 h and also degrade the reaction intermediates (aromatic amines) during the subsequent 12 h under aerobic conditions. The tubular gel harboring the immobilized cells consisted of anoxic and aerobic regions integrated in a single unit...

  16. Immobilization of spent resin with epoxy resin

    International Nuclear Information System (INIS)

    immobilization of spent resin using epoxy resin has been conducted. The spent resin was mixtured with epoxy resin in variation of concentration, i.e., 30, 40, 50, 60, 70 weight percent of spent resin. The mixture were pour into the plastic tube, with a diameter of 40 mm and height of 40 mm. The density, compressive strength and leaching rate were respectively measured by quanta chrome, paul weber apparatus and gamma spectrometer. The results showed that the increasing of waste concentration would be decreased the compressive strength, and increased density by immobilized waste. The leaching rate of 137Cs from waste product was not detected in experiment (author)

  17. Radiation Synthesis of Nanogel for Bioactives Immobilization

    International Nuclear Information System (INIS)

    Both hydrophilic and hydrophobic core nanogel are currently being developed for immobilization and delivery purposes in Malaysian Nuclear Agency. Hydrophilic nanogel is produced by using inverse micelles irradiation of polyethelyne glycol diacrylate (PEGDA). The hydrophobic nanogel is produced via irradiation of acrylated form of palm oil. These nanogels will be used to immobilize bio actives such as curcumin, tyhmoquinone, oryzanol and chitosan. Preliminary investigation of the nanogel size using dynamic light scattering (DLS) shows that nanogel with sizes below 100nm can be obtained. (author)

  18. Use of PVA-gel immobilized cells: a new strategy for biotechnological production of Xylitol from sugarcane bagasse hidrolysate/ Uso de células imobilizadas em gel de PVA: uma nova estratégia para produção biotecnológica de Xilitol a partir de bagaço de cana-de-açúcar

    Directory of Open Access Journals (Sweden)

    Júlio César dos Santos

    2005-06-01

    Full Text Available Sugarcane bagasse is one of the most abundant residues in Brazil due to the large number of sugaralcohol industries. This biomass contains a high concentration of carbohydrates, which can be converted into products of high economic value, such as xylitol. Xylitol, a polyol with anticariogenic properties, is similar in sweetening power to sucrose, and has high potential for use in the food and pharmaceutical industries. Several studies have been carried out to produce xylitol by biotechnological processes. However, there is little information on the use of immobilized cells in these bioprocesses. The objective of this review was to present a new possibility to produce xylitol by biotechnological processes, using sugarcane bagasse hydrolysate and immobilized cells in PVA-gel.O bagaço de cana-de-açúcar é um dos resíduos mais abundantes no Brasil devido ao grande número de indústrias sucroalcooleiras. Esta biomassa contém elevado teor de carboidratos, podendo ser utilizada na produção de compostos de interesse econômico como o xilitol. O xilitol é um poliol de cinco carbonos que apresenta poder adoçante semelhante ao da sacarose e propriedades anti-cariogênicas, tendo elevado potencial de uso nas indústrias alimentícias e farmacêuticas. Diversos estudos buscando o desenvolvimento de processos de produção de xilitol por via biotecnológica têm sido realizados, entretanto pouco tem sido escrito sobre a utilização de células imobilizadas no bioprocesso. A presente revisão tem como objetivo apresentar uma possibilidade de produção de xilitol a partir de hidrolisado hemicelulósico de bagaço de canade-açúcar, em sistema com células imobilizadas em gel de álcool polivinílico.

  19. Airlift bioreactor containing chitosan-immobilized Sphingobium sp. P2 for treatment of lubricants in wastewater.

    Science.gov (United States)

    Khondee, Nichakorn; Tathong, Sitti; Pinyakong, Onruthai; Powtongsook, Sorawit; Chatchupong, Thawach; Ruangchainikom, Chalermchai; Luepromchai, Ekawan

    2012-04-30

    An internal loop airlift bioreactor containing chitosan-immobilized Sphingobium sp. P2 was applied for the removal of automotive lubricants from emulsified wastewater. The chitosan-immobilized bacteria had higher lubricant removal efficiency than free and killed-immobilized cells because they were able to sorp and degrade the lubricants simultaneously. In a semi-continuous batch experiment, the immobilized bacteria were able to remove 80-90% of the 200 mg L(-1) total petroleum hydrocarbons (TPH) from both synthetic and carwash wastewater. The internal loop airlift bioreactor, containing 4 g L(-1) immobilized bacteria, was later designed and operated at 2.0 h HRT (hydraulic retention time) for over 70 days. At a steady state, the reactor continuously removed 85±5% TPH and 73±11% chemical oxygen demand (COD) from the carwash wastewater with 25-200 mg L(-1) amended lubricant. The internal loop airlift reactor's simple operation and high stability demonstrate its high potential for use in treating lubricants in emulsified wastewater from carwashes and other industries. PMID:22398031

  20. Nitrification performance of nitrifying bacteria immobilized in waterborne polyurethane at low ammonia nitrogen concentrations

    Institute of Scientific and Technical Information of China (English)

    Yamei Dong; Zhenjia Zhang; Yongwei Jin; Zhirong Li; Jian Lu

    2011-01-01

    Suspended and waterborne polyurethane immobilized nitrifying bacteria have been adopted for evaluating the effects of environmental changes, such as temperature, dissolved oxygen (DO) concentration and pH, on nitrification characteristics under conditions of low ammonia concentrations.The results showed that nitrification was prone to complete with increasing pH, DO and temperature.Sensitivity analysis demonstrated the effects of temperature and pH on nitrification feature of suspended bacteria were slightly greater than those of immobilized nitrifying bacteria.Immobilized cells could achieve complete nitrification at low ammonia concentrations when DO was sufficient.Continuous experiments were carried out to discuss the removal of ammonia nitrogen from synthetic micropollute source water with the ammonia concentration of about 1 mg/L using immobilized nitrifying bacteria pellets in an up-flow inner circulation reactor under different hydraulic retention times (HRT).The continuous removal rate remains above 80% even under HRT 30 min.The results verified that the waterborne polyurethane immobilized nitrifying bacteria pellets had great potential applications for micro-pollution source water treatment.

  1. Intensified nitrogen removal in immobilized nitrifier enhanced constructed wetlands with external carbon addition.

    Science.gov (United States)

    Wang, Wei; Ding, Yi; Wang, Yuhui; Song, Xinshan; Ambrose, Richard F; Ullman, Jeffrey L

    2016-10-01

    Nitrogen removal performance response of twelve constructed wetlands (CWs) to immobilized nitrifier pellets and different influent COD/N ratios (chemical oxygen demand: total nitrogen in influent) were investigated via 7-month experiments. Nitrifier was immobilized on a carrier pellet containing 10% polyvinyl alcohol (PVA), 2.0% sodium alginate (SA) and 2.0% calcium chloride (CaCl2). A batch experiment demonstrated that 73% COD and 85% ammonia nitrogen (NH4-N) were degraded using the pellets with immobilized nitrifier cells. In addition, different carbon source supplement strategies were applied to remove the nitrate (NO3-N) transformed from NH4-N. An increase in COD/N ratio led to increasing reduction in NO3-N. Efficient nitrification and denitrification promoted total nitrogen (TN) removal in immobilized nitrifier biofortified constructed wetlands (INB-CWs). The results suggested that immobilized nitrifier pellets combined with high influent COD/N ratios could effectively improve the nitrogen removal performance in CWs. PMID:27396293

  2. Immobilization and direct electrochemistry of copper-containing enzymes on active carbon

    Institute of Scientific and Technical Information of China (English)

    SUN Dongmei; CAI Chenxin; XING Wei; LU Tianhong

    2004-01-01

    Two typical and important copper-containing enzymes, laccase (Lac) and tyrosinase (Tyr), have been immobilized on the surface of active carbon with simple adsorption method. The cyclic voltammetric results indicated that the active carbon could promote the direct electron transfer of both Lac and Tyr and a pair of well-defined and nearly symmetric redox peaks appeared on the cyclic voltammograms of Lac or Tyr with the formal potential, E0′, independent on the scan rate. The further experimental results showed that the immobilized copper-containing oxidase displayed an excellent electrocatalytic activity to the electrochemical reduction of O2. The immobilization method presented here has several advantages, such as simplicity, easy to operation and keeping good activity of enzyme etc., and could be further used to study the direct electrochemistry of other redox proteins and enzymes and fabricate the catalysts for biofuel cell.

  3. Hydrogels for immobilization of bacteria used in the treatment of metal-contaminated wastes

    Science.gov (United States)

    Degiorgi, C. Fernández; Pizarro, R. A.; Smolko, E. E.; Lora, S.; Carenza, M.

    2002-01-01

    Polymeric matrices prepared by gamma irradiation of 2-hydroxyethyl methacrylate and 2-hydroxyethyl acrylate at -78°C in the presence of water and glycerol and poly(vinyl alcohol) membranes were examined as carriers for immobilization of bacterial cells in experiments of metal decontamination. Bacterial strains capable of growing in the presence of heavy metals were selected from soil and water from the Rı´o de la Plata coasts in Argentina and cultured in the hydrophilic membranes with the aim of bioremediation of the standard contaminated solutions. The results obtained indicate that removal from free bacteria was more efficient for Pb(II) and Cd(II) than for Cr(III) and Cu(II). It was ascertained that all metals could be immobilized in the polymer matrices to some extent. The Cr(III) ion concentration in bacteria immobilized on the acrylic hydrogel was approximately double of that found in the poly(vinyl alcohol) membrane.

  4. Improved immobilization of laccase on a glassy carbon electrode by oriented covalent attachment

    Directory of Open Access Journals (Sweden)

    Liu Xin

    2014-01-01

    Full Text Available A laccase from Thermus thermophilus HB27 was reported to be potentially useful in the design of a temperature controlled biofuel cell. For enhancing its application in different thermal conditions, we engineered a laccase-oriented immobilized electrode. A site-directed mutant N323C of the laccase was constructed. A photometric assay was employed in order to compare the catalytic properties of wild-type laccase and mutant. The mutant was attached to a glass carbon electrode by covalent cross-linking. The electrochemical properties of the immobilized laccase were investigated by cyclic voltammetry. This immobilization allowed the active electrode to function at temperatures up to 95°C. The thermal and pH dependence profiles were similar to those of the soluble enzyme investigated by spectrophotometry.

  5. 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

  6. 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.

  7. Limb immobilization induces a coordinate down-regulation of mitochondrial and other metabolic pathways in men and women.

    Directory of Open Access Journals (Sweden)

    Arkan Abadi

    Full Text Available Advancements in animal models and cell culture techniques have been invaluable in the elucidation of the molecular mechanisms that regulate muscle atrophy. However, few studies have examined muscle atrophy in humans using modern experimental techniques. The purpose of this study was to examine changes in global gene transcription during immobilization-induced muscle atrophy in humans and then explore the effects of the most prominent transcriptional alterations on protein expression and function. Healthy men and women (N = 24 were subjected to two weeks of unilateral limb immobilization, with muscle biopsies obtained before, after 48 hours (48 H and 14 days (14 D of immobilization. Muscle cross sectional area (approximately 5% and strength (10-20% were significantly reduced in men and women (approximately 5% and 10-20%, respectively after 14 D of immobilization. Micro-array analyses of total RNA extracted from biopsy samples at 48 H and 14 D uncovered 575 and 3,128 probes, respectively, which were significantly altered during immobilization. As a group, genes involved in mitochondrial bioenergetics and carbohydrate metabolism were predominant features at both 48 H and 14 D, with genes involved in protein synthesis and degradation significantly down-regulated and up-regulated, respectively, at 14 D of muscle atrophy. There was also a significant decrease in the protein content of mitochondrial cytochrome c oxidase, and the enzyme activity of cytochrome c oxidase and citrate synthase after 14 D of immobilization. Furthermore, protein ubiquitination was significantly increased at 48 H but not 14 D of immobilization. These results suggest that transcriptional and post-transcriptional suppression of mitochondrial processes is sustained throughout 14 D of immobilization, while protein ubiquitination plays an early but transient role in muscle atrophy following short-term immobilization in humans.

  8. Immobilization of Isolated Lipase From Moldy Copra (Aspergillus Oryzae)

    OpenAIRE

    Seniwati

    2012-01-01

    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 op...

  9. Immobilization of Isolated Lipase From Moldy Copra (Aspergillus Oryzae)

    OpenAIRE

    Seniwati Dali; A. B. D. Rauf Patong; M.Noor Jalaluddin; Pirman; Baharuddin Hamzah

    2011-01-01

    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 ...

  10. Immobilization of horseradish peroxidase on β-cyclodextrin-capped silver nanoparticles: Its future aspects in biosensor application.

    Science.gov (United States)

    Karim, Zoheb; Khan, Mohd Jahir; Maskat, Mohamad Yusof; Adnan, Rohana

    2016-05-18

    This study aimed to work out a simple and high-yield procedure for the immobilization of horseradish peroxidase on silver nanoparticle. Ultraviolet-visible (UV-vis) and Fourier-transform infrared spectroscopy and transmission electron microscopy were used to characterize silver nanoparticles. Horseradish peroxidase was immobilized on β-cyclodextrin-capped silver nanoparticles via glutaraldehyde cross-linking. Single-cell gel electrophoresis (Comet assay) was also performed to confirm the genotoxicity of silver nanoparticles. To decrease toxicity, silver nanoparticles were capped with β-cyclodextrin. A comparative stability study of soluble and immobilized enzyme preparations was investigated against pH, temperature, and chaotropic agent, urea. The results showed that the cross-linked peroxidase was significantly more stable as compared to the soluble counterpart. The immobilized enzyme exhibited stable enzyme activities after repeated uses. PMID:25830286

  11. 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. PMID:27211619

  12. Kinetic studies on degradation of Reactive Red 120 dye in immobilized packed bed reactor by Bacillus cohnii RAPT1.

    Science.gov (United States)

    Padmanaban, V C; Geed, Sachin RameshRao; Achary, Anant; Singh, R S

    2016-08-01

    The degradation of Reactive Red 120 using Bacillus cohnii RAPT1 immobilized on polyurethane was studied. Initial experiments indicated that the percentage removal of dye in immobilized batch was significantly higher than batch (without immobilization). The optimum process parameters such as effect of dye concentration, time of immobilization on Poly Urethane Foam, initial inoculum size, pH and temperature for removal of dye were investigated and was found as 200ppm, 36h, 300*10(6) colony forming units/ml, 8.0 and 35°C respectively. Under optimum conditions, 100% removal of dye was obtained within 4h. The kinetics of biodegradation for the batch with free cells and immobilised packed batch was found to be IInd order with kinetic constant and initial rate of reaction as 0.0408, 0.084L/(mgday) and 1632, 3360 (mg/Lday) respectively. PMID:26968121

  13. Surface engineering of Ti-O films by photochemical immobilization of gelatin

    International Nuclear Information System (INIS)

    Crystalline Ti-O films were prepared by unbalanced magnetron sputtering and the structure was confirmed by XRD. An organic layer of 3-aminopropylphosphonic acid (APP) was first introduced on the Ti-O films by self-assembling. The stability of the APP on Ti-O films was confirmed by XPS and FTIR analysis. Simultaneously, azido group was introduced in gelatin molecule to act as photoreactive point. The derivated gelatin was spin-coated onto the self-assembled layer and immobilized by UV irradiating. Chemical patterned surface was obtained by using a photomask when irradiating and confirmed by sirius red staining and surface profile analysis. Measured by surface profilometer, the thickness of the immobilized gelatin was about 5-20 nm. The adhering of human endothelial EVC304 cells on APP modified surface was enhanced in the cell culture test. Moreover, the adherence and growth of cells were prior on gelatin-immobilized region visually seen on the patterned surface. This result indicated gelatin-immobilized Ti-O surface can serve as a biocompatible biomaterial for endothelialization

  14. Surface engineering of Ti-O films by photochemical immobilization of gelatin

    Energy Technology Data Exchange (ETDEWEB)

    Weng, Y.J.; Ren, J.R. [Department of Materials Engineering, Southwest Jiaotong University, Chengdu 610031 (China); Key Lab for Advanced Technologies of Materials, Ministry of Education, Southwest Jiaotong University, Chengdu, 610031 (China); Huang, N. [Department of Materials Engineering, Southwest Jiaotong University, Chengdu 610031 (China) and Key Lab for Advanced Technologies of Materials, Ministry of Education, Southwest Jiaotong University, Chengdu, 610031 (China)], E-mail: nhuang@263.net; Wang, J.; Chen, J.Y.; Leng, Y.X.; Liu, H.Q. [Department of Materials Engineering, Southwest Jiaotong University, Chengdu 610031 (China); Key Lab for Advanced Technologies of Materials, Ministry of Education, Southwest Jiaotong University, Chengdu, 610031 (China)

    2008-12-01

    Crystalline Ti-O films were prepared by unbalanced magnetron sputtering and the structure was confirmed by XRD. An organic layer of 3-aminopropylphosphonic acid (APP) was first introduced on the Ti-O films by self-assembling. The stability of the APP on Ti-O films was confirmed by XPS and FTIR analysis. Simultaneously, azido group was introduced in gelatin molecule to act as photoreactive point. The derivated gelatin was spin-coated onto the self-assembled layer and immobilized by UV irradiating. Chemical patterned surface was obtained by using a photomask when irradiating and confirmed by sirius red staining and surface profile analysis. Measured by surface profilometer, the thickness of the immobilized gelatin was about 5-20 nm. The adhering of human endothelial EVC304 cells on APP modified surface was enhanced in the cell culture test. Moreover, the adherence and growth of cells were prior on gelatin-immobilized region visually seen on the patterned surface. This result indicated gelatin-immobilized Ti-O surface can serve as a biocompatible biomaterial for endothelialization.

  15. Immobilized Ruthenium Catalyst for Carbon Dioxide Hydrogenation

    Institute of Scientific and Technical Information of China (English)

    Ying Min YU; Jin Hua FEI; Yi Ping ZHANG; Xiao Ming ZHENG

    2006-01-01

    Three kinds of cross linked polystyrene resin (PS) supported ruthenium complexes were developed as catalysts for the synthesis of formic acid from carbon dioxide hydrogenation. Many factors, such as the functionalized supports, solvents and ligands, could influence their activities and reuse performances greatly. These immobilized catalysts also offer the industrial advantages such as easy separation.

  16. 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. PMID:26747440

  17. Plutonium Immobilization Can Loading Preliminary Specifications

    Energy Technology Data Exchange (ETDEWEB)

    Kriikku, E.

    1998-11-25

    This report discusses the Plutonium Immobilization can loading preliminary equipment specifications and includes a process block diagram, process description, equipment list, preliminary equipment specifications, plan and elevation sketches, and some commercial catalogs. This report identifies loading pucks into cans and backfilling cans with helium as the top priority can loading development areas.

  18. Immobilization of DNA for scanning probe microscopy.

    OpenAIRE

    Allison, D. P.; Bottomley, L A; T. Thundat; Brown, G M; Woychik, R. P.; Schrick, J. J.; Jacobson, K B; Warmack, R J

    1992-01-01

    Reproducible scanning tunneling microscope and atomic force microscope images of entire molecules of uncoated plasmid DNA chemically bound to surfaces are presented. The chemically mediated immobilization of DNA to surfaces and subsequent scanning tunneling microscope imaging of DNA molecules demonstrate that the problem of molecular instability to forces exerted by the probe tip, inherent with scanning probe microscopes, can be prevented.

  19. 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 ca...

  20. Immobilization of Enzymes in Polymer Supports.

    Science.gov (United States)

    Conlon, Hugh D.; Walt, David R.

    1986-01-01

    Two experiments in which an enzyme is immobilized onto a polymeric support are described. The experiments (which also demonstrate two different polymer preparations) involve: (1) entrapping an enzyme in an acrylamide polymer; and (2) reacting the amino groups on the enzyme's (esterase) lysine residues with an activated polymer. (JN)

  1. Adsorption of metals by immobilized tannins

    International Nuclear Information System (INIS)

    Simultaneous adsorption of thorium, europium, cerium, and neodymium by immobilized tannic was studied at different ph values. Tannic materials have excellent ability to adsorb selectively thorium at pH 5. The rest of the elements could be isolated in group at pH 7

  2. Application of radiopolymerization for immobilization of enzymes

    International Nuclear Information System (INIS)

    Hydrophilic glass-forming monomers were used in an application of irradiation technology for the immobilization of cellulase and cellobiase. Experiments to observe the effect of additives such as silicates and polyethylene glycol in the enzyme entrapment are reported on. In all cases, enzymatic activity was maintained for more than fifteen batch enzyme reactions. (Author)

  3. Plutonium Immobilization Project -- Robotic canister loading

    Energy Technology Data Exchange (ETDEWEB)

    Hamilton, L.

    2000-04-28

    The Plutonium Immobilization Program (PIP) is a joint venture between the Savannah River Site, Lawrence Livermore National Laboratory, Argonne National Laboratory, and Pacific Northwest National Laboratory. When operational in 2008, the PIP will fulfill the nation's nonproliferation commitment by placing surplus weapons-grade plutonium in a permanently stable ceramic form.

  4. Silanization and antibody immobilization on SU-8

    Science.gov (United States)

    Joshi, Manoj; Pinto, Richard; Rao, V. Ramgopal; Mukherji, Soumyo

    2007-01-01

    SU-8, an epoxy based negative photoresist, has emerged as a structural material for microfabricated sensors due to its attractive mechanical properties like low Young's modulus and chemical properties like inertness to various chemicals used in microfabrication. It can be used to fabricate MEMS structures of high aspect ratio. However, the use of SU-8 in BioMEMS application has been limited by the fact that immobilization of biomolecules on SU-8 surfaces has not been reported. In this study, the epoxy groups on the SU-8 surface were hydrolyzed in the presence of sulphochromic solution. Following this, the surface was treated with [3-(2-aminoethyl) aminopropyl]-trimethoxysilane (AEAPS). The silanized SU-8 surface was used to incubate human immunoglobulin (HIgG). The immobilization of HIgG was proved by allowing FITC tagged goat anti-human IgG to react with HIgG. This process of antibody immobilization was used to immobilize HIgG on microfabricated SU-8 cantilevers.

  5. Short-Term Limb Immobilization Affects Cognitive Motor Processes

    Science.gov (United States)

    Toussaint, Lucette; Meugnot, Aurore

    2013-01-01

    We examined the effects of a brief period of limb immobilization on the cognitive level of action control. A splint placed on the participants' left hand was used as a means of immobilization. We used a hand mental rotation task to investigate the immobilization-induced effects on motor imagery performance (Experiments 1 and 2) and a number mental…

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

    OpenAIRE

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

    2016-01-01

    The physically adsorbed acetylcholinesterase on mesoporous silicon surface is presented. The catalytic behavior of immobilized enzyme was assessed by spectrophotometric bioassay. The immobilization enhanced the reusability, shelf life and thermal as well as pH stability

  7. Heterofunctional Supports in Enzyme Immobilization: From Traditional Immobilization Protocols to Opportunities in Tuning Enzyme Properties

    OpenAIRE

    Barbosa, Oveimar; Torres, Rodrigo; Ortiz, Claudia; Berenguer Murcia, Ángel; Rafael C. Rodrigues; Fernández Lafuente, Roberto

    2013-01-01

    A heterofunctional support for enzyme immobilization may be defined as that which possesses several distinct functionalities on its surface able to interact with a protein. We will focus on those supports in which a final covalent attachment between the enzyme and the support is achieved. Heterofunctionality sometimes has been featured in very old immobilization techniques, even though in many instances it has been overlooked, giving rise to some misunderstandings. In this respect, glutaralde...

  8. Ethanol fermentation of mahula (Madhuca latifolia L.) flowers using free and immobilized yeast Saccharomyces cerevisiae.

    Science.gov (United States)

    Swain, M R; Kar, S; Sahoo, A K; Ray, R C

    2007-01-01

    There is a growing interest to find alternate bioresources for production of ethanol, apart from cane/sugar beet molasses and starchy crops like sweet sorghum, cassava and sweet potato. Mahula (Madhuca latifolia L.) is a forest tree abundantly available in the Indian subcontinent and its flowers are very rich in fermentable sugars (28.1-36.3 g 100 g(-1)). Batch fermentation of fresh and 12-month-stored flowers with free (whole cells) and immobilized cells of Saccharomyces cerevisiae (strain CTCRI) was carried out in 2-l Erlenmeyer flasks. The ethanol yields were 193 and 148 g kg(-1) (using free cells) and 205 and 152 g kg(-1) (using immobilized cells) from fresh and 12-month-stored mahula flowers, respectively. PMID:16580830

  9. Design features of the laboratory-scale radiochemical immobilization system

    International Nuclear Information System (INIS)

    Under the High-Level Waste Immobilization Program, the Pacific Northwest Laboratory (PNL) is studying various ways to solidify high-level nuclear wastes. A variety of waste forms and processes are being investigated, with the most highly developed process being spray calcination coupled with in-can melting. This report describes a remote laboratory-scale system that was designed for the purpose of investigating the effects of different operating conditions and waste compositions on the product and on the effluents generated. It is termed laboratory-scale because of its nominal 1 L/h feed rate as compared to well over 300 L/h for full-scale equipment at PNL. The equipment currently consists of a feed system, a spray calciner, an in-can melter, and an effluent control system. It is operated in a shielded radiochemical hot cell using radioactive high-level liquid waste (HLLW) to answer questions on the deposition of radiochemicals during actual waste processing. The effluent control system can be modified in order to test different effluent systems, one of which has been proposed by the Savannah River Laboratories (SRL) for use in the Savannah River Plant vitrification system. The laboratory-scale system can also be used to test alternative immobilization processes, since spray calcination is a common processing step in many alternative waste form flowsheets. Thus, only the addition of a specific forming step such as pelletizing or sintering is necessary

  10. Immobilization of horseradish peroxidase on modified chitosan beads.

    Science.gov (United States)

    Monier, M; Ayad, D M; Wei, Y; Sarhan, A A

    2010-04-01

    A method has been developed to immobilize horseradish peroxidase (HRP) on modified chitosan beads by means of graft copolymerization of polyethylacrylate in presence of potassium persulphate and Mohr's salt redox initiator. The activity of free and immobilized HRP was studied. FTIR spectroscopy and scanning electron microscopy were used to characterize HRP immobilization. The efficiency of the immobilization was investigated by examining the relative enzymatic activity of free enzyme before and after the HRP immobilization. The obtained values were found to reach 98.4%. The results show that the optimum temperature of immobilized HRP was 45 degrees C, which was identical to that of free enzyme, and the immobilized HRP exhibited a higher relative activity than that of free HRP over 45 degrees C. The optimal pH for immobilized HRP was 10, which was higher than that of the free HRP (pH 9.0), and the immobilization resulted in stabilization of enzyme over a broader pH range. The apparent kinetic constant value (K(m)) of immobilized HRP was 3.784 mmol ml(-1), which was higher than that of free HRP. On the other hand, the activity of immobilized HRP decreased slowly against time when compared to that of the free HRP, and could retain 65.8% residual activity after 6 consecutive cycles. PMID:20060854

  11. Immobilization of amyloglucosidase using two forms of polyurethane polymer.

    Science.gov (United States)

    Storey, K B; Duncan, J A; Chakrabarti, A C

    1990-03-01

    Amyloglucosidase was covalently immobilized using two hydrophilic prepolymers: Hypol FHP 2002 (creates foams) and Hypol FHP 8190H (creates gels). The foamable prepolymer was superior as a support for enzyme immobilization. The percent activity immobilized in the polyurethane foams was 25 +/- 1.5%. Large substrates (greater than 200,000 daltons in mol wt) were hydrolyzed as effectively as smaller ones by the immobilized enzyme. The Km value of the foam-immobilized enzyme increased from 0.76 mg/mL (free) to 0.86 mg/mL (immobilized), whereas the Vmax dropped from 90.9 (free) to 12.4 nmol glucose/min/mL (immobilized). The long-term (2 mo) storage stability of amyloglucosidase was enhanced by immobilization in foams (70% activity retained; free enzyme only retained 50%). Immobilization also improved the enzyme stability to various denaturing agents (sodium chloride, urea, and ethanol). The immobilized enzyme exhibited increased stability compared to the free enzyme at high temperatures (95 degrees C). Both glycogen and starch could be utilized by the immobilized enzyme, indicating that this technique could prove useful for starch hydrolysis. PMID:2112366

  12. Screening of supports for immobilization of commercial porcine pancreatic lipase

    Directory of Open Access Journals (Sweden)

    Robison Scherer

    2011-12-01

    Full Text Available The aim of this work is to report the performance of different supports for the immobilization of commercial porcine pancreatic lipase. The immobilization tests were carried out in several types of Accurel, activated alumina, kaolin, montmorillonite, ion exchange resins and zeolites. The characterization of the supports showed differences in terms of specific area and morphology. The characteristics of the supports influenced the amount of enzyme adsorbed, yield of immobilization and esterification activity of the resulting immobilized catalyst. The clays KSF and natural and pillared montmorillonites presented potential for use as support for lipase immobilization in terms of yield and esterification activity. Yields of immobilization of 76.32 and 52.01% were achieved for clays KSF and natural montmorillonite, respectively. Esterification activities of 754.03, 595.51, 591.88 and 515.71 U.g-1 were obtained for lipases immobilized in Accurel MP-100, Amberlite XAD-2, mordenite and pillared montmorillonite, respectively.

  13. Preparation and characterization of latex films photo-immobilized with IFN-α.

    Science.gov (United States)

    Wu, Lifang; Hu, Kaikai; Zhang, Li; Chen, Wuya; Chen, Xiaohui; You, Rong; Yin, Liang; Guan, Yan-Qing

    2016-09-01

    We developed a biomaterial by photo-immobilizing interferon-α (IFN-α) on the surface of latex condom films for the prevention and treatment of cervicitis, cervical cancers and diseases caused by cervical virus. The IFN-α modification by photoactive N-(4-azidobenzoyloxy) succinimide was characterized on a nano-scale by spectroscopy analysis and micro morphology. The anti-bacterial, anti-cancer, and anti-viral effects of the modified bioactive latex films were evaluated by antibacterial susceptibility testing, Gram staining, flow cytometry, immunofluorescence, and Western blotting. Our results showed that the photo-immobilized IFN-α latex films effectively inhibited the growth of both Neisseria gonorrhoeae and human cervical cancer HeLa cells. Moreover, the expression of anti-viral proteins, including P56, MxA, and 2', 5'-OAS, in the human cervical epithelial cell line NC104 was significantly increased by photo-immobilized IFN-α latex films. Taken together, these results suggest that photo-immobilized IFN-α latex films may have therapeutic effects against cervicitis, cervical cancers, and cervical virus. PMID:27137809

  14. Sequential Fermentation with Selected Immobilized Non-Saccharomyces Yeast for Reduction of Ethanol Content in Wine

    Science.gov (United States)

    Canonico, Laura; Comitini, Francesca; Oro, Lucia; Ciani, Maurizio

    2016-01-01

    The average ethanol content of wine has increased over the last two decades. This increase was due to consumer preference, and also to climate change that resulted in increased grape maturity at harvest. In the present study, to reduce ethanol content in wine, a microbiological approach was investigated, using immobilized selected strains of non-Saccharomyces yeasts namely Starmerella bombicola, Metschnikowia pulcherrima, Hanseniaspora osmophila, and Hanseniaspora uvarum to start fermentation, followed by inoculation of free Saccharomyces cerevisiae cells. The immobilization procedures, determining high reaction rates, led a feasible sequential inoculation management avoiding possible contamination under actual winemaking. Under these conditions, the immobilized cells metabolized almost 50% of the sugar in 3 days, while S. cerevisiae inoculation completed all of fermentation. The S. bombicola and M. pulcherrima initial fermentations showed the best reductions in the final ethanol content (1.6 and 1.4% v/v, respectively). Resulting wines did not have any negative fermentation products with the exception of H. uvarum sequential fermentation that showed significant amount of ethyl acetate. On the other hand, there were increases in desirable compounds such as glycerol and succinic acid for S. bombicola, geraniol for M. pulcherrima and isoamyl acetate and isoamyl alcohol for H. osmophila sequential fermentations. The overall results indicated that a promising ethanol reduction could be obtained using sequential fermentation of immobilized selected non-Saccharomyces strains. In this way, a suitable timing of second inoculation and an enhancement of analytical profile of wine were obtained. PMID:27014203

  15. Sequential Fermentation with Selected Immobilized Non-Saccharomyces Yeast for Reduction of Ethanol Content in Wine.

    Science.gov (United States)

    Canonico, Laura; Comitini, Francesca; Oro, Lucia; Ciani, Maurizio

    2016-01-01

    The average ethanol content of wine has increased over the last two decades. This increase was due to consumer preference, and also to climate change that resulted in increased grape maturity at harvest. In the present study, to reduce ethanol content in wine, a microbiological approach was investigated, using immobilized selected strains of non-Saccharomyces yeasts namely Starmerella bombicola, Metschnikowia pulcherrima, Hanseniaspora osmophila, and Hanseniaspora uvarum to start fermentation, followed by inoculation of free Saccharomyces cerevisiae cells. The immobilization procedures, determining high reaction rates, led a feasible sequential inoculation management avoiding possible contamination under actual winemaking. Under these conditions, the immobilized cells metabolized almost 50% of the sugar in 3 days, while S. cerevisiae inoculation completed all of fermentation. The S. bombicola and M. pulcherrima initial fermentations showed the best reductions in the final ethanol content (1.6 and 1.4% v/v, respectively). Resulting wines did not have any negative fermentation products with the exception of H. uvarum sequential fermentation that showed significant amount of ethyl acetate. On the other hand, there were increases in desirable compounds such as glycerol and succinic acid for S. bombicola, geraniol for M. pulcherrima and isoamyl acetate and isoamyl alcohol for H. osmophila sequential fermentations. The overall results indicated that a promising ethanol reduction could be obtained using sequential fermentation of immobilized selected non-Saccharomyces strains. In this way, a suitable timing of second inoculation and an enhancement of analytical profile of wine were obtained. PMID:27014203

  16. Immobilization of calcium and phosphate ions improves the osteoconductivity of titanium implants.

    Science.gov (United States)

    Sunarso; Toita, Riki; Tsuru, Kanji; Ishikawa, Kunio

    2016-11-01

    In this work, to elevate weak osteoconductivity of titanium (Ti) implant, we prepared a Ti implant having both calcium and phosphate ions on its surface. To modify calcium and phosphate ions onto Ti, phosphate ions were first immobilized by treating the Ti with a NaH2PO4 solution, followed by CaCl2 treatment to immobilize calcium ions, which created the calcium and phosphate ions-modified Ti (Ca-P-Ti). X-ray photoelectron spectroscopy and thin-layer X-ray diffraction measurement confirmed that both phosphate and calcium ions were co-immobilized onto the Ti surface on the molecular level. Three-hour after seeding MC3T3-E1 murine pre-osteoblast cells on substrates, cell number on Ca-P-Ti was much larger than that of Ti and phosphate-modified Ti (P-Ti), but was similar to that of calcium-modified Ti (Ca-Ti). Also, MC3T3-E1 cells on Ca-P-Ti expressed larger amount of vinculin, a focal adhesion protein, than those on other substrates, probably resulting in larger cell size as well as greater cell proliferation on Ca-P-Ti than those on other substrates. Alkaline phosphatase activity of cells on Ca-P-Ti was greater than those on Ti and P-Ti, but was almost comparable to that of Ca-Ti. Moreover, the largest amount of bone-like nodule formation was observed on Ca-P-Ti. These results provide evidence that calcium and phosphate ions-co-immobilization onto Ti increased the osteoconductivity of Ti by stimulating the responses of pre-osteoblast cells. This simple modification would be promising technique for bone tissue implant including dental and orthopedic implants. PMID:27524023

  17. Produção de compostos fenólicos a partir de células imobilizadas do líquen Parmotrema andinum (Müll. Arg. Hale e avaliação de atividade antimicrobiana Production of phenolic compounds from immobilized cells of the lichen Pamotrema andinum (Müll. Arg. Hale and evaluation of antimicrobial activity

    Directory of Open Access Journals (Sweden)

    Nadejda de Azevedo Nóbrega

    2012-03-01

    Full Text Available A utilização de metabólitos secundários obtidos de líquens, na indústria farmacêutica, de cosmético, têxtil e de alimentos deve ser criteriosa, visto que a extração e isolamento desses metabólitos requerem uma grande quantidade de biomassa dificilmente renovável, devido ao crescimento lento do líquen. Atualmente, é possível obter substâncias liquênicas tanto por cultivo de tecidos, como por imobilizações celulares e enzimáticas, a partir do talo in natura, utilizando pequena quantidade de material liquênico. Portanto, este trabalho objetiva investigar a produção de compostos fenólicos a partir de células imobilizadas de Parmotrema andinum (Müll. Arg. Hale utilizando acetato de sódio como precursor da biossíntese dos fenóis. Ensaios de atividade antimicrobiana com extratos orgânicos do talo in natura, eluatos celulares e do ácido lecanórico isolado de P. andinum Hale demonstraram ação contra bactérias Gram-positivas. Através de testes biocromatográficos foi possível associar a atividade antibacteriana ao ácido lecanórico e uma substância não identificada presente na espécie. As substâncias produzidas através de imobilização celular não exibiram ação inibitória frente os microrganismos testados.Hale and evaluation of antimicrobial activity. Secondary metabolites obtained from lichens should be carefully used by the pharmaceutical, cosmetic, textile and food industries because the extraction and isolation of these metabolites requires large amounts of biomass, which is not renewable due to how slow lichens grow. Nowadays, it is possible to obtain these substances either by tissue culture or cell and enzymatic immobilizations, from an in natura thallus, using a small amount of lichenous material. Therefore, this work aimed to investigate the production of phenolic compounds from Parmotrema andinum (Müll. Arg. Hale immobilized cells, using sodium acetate as a precursor in the biosynthesis of

  18. Immobilization of Dystrophin and Laminin α2-Chain Deficient Zebrafish Larvae In Vivo Prevents the Development of Muscular Dystrophy.

    Directory of Open Access Journals (Sweden)

    Mei Li

    Full Text Available Muscular dystrophies are often caused by genetic alterations in the dystrophin-dystroglycan complex or its extracellular ligands. These structures are associated with the cell membrane and provide mechanical links between the cytoskeleton and the matrix. Mechanical stress is considered a pathological mechanism and muscle immobilization has been shown to be beneficial in some mouse models of muscular dystrophy. The zebrafish enables novel and less complex models to examine the effects of extended immobilization or muscle relaxation in vivo in different dystrophy models. We have examined effects of immobilization in larvae from two zebrafish strains with muscular dystrophy, the Sapje dystrophin-deficient and the Candyfloss laminin α2-chain-deficient strains. Larvae (4 days post fertilization, dpf of both mutants have significantly lower active force in vitro, alterations in the muscle structure with gaps between muscle fibers and altered birefringence patterns compared to their normal siblings. Complete immobilization (18 hrs to 4 dpf was achieved using a small molecular inhibitor of actin-myosin interaction (BTS, 50 μM. This treatment resulted in a significantly weaker active contraction at 4 dpf in both mutated larvae and normal siblings, most likely reflecting a general effect of immobilization on myofibrillogenesis. The immobilization also significantly reduced the structural damage in the mutated strains, showing that muscle activity is an important pathological mechanism. Following one-day washout of BTS, muscle tension partly recovered in the Candyfloss siblings and caused structural damage in these mutants, indicating activity-induced muscle recovery and damage, respectively.

  19. Enzyme-Immobilized Microfluidic Process Reactors

    Directory of Open Access Journals (Sweden)

    Hideaki Maeda

    2011-07-01

    Full Text Available Microreaction technology, which is an interdisciplinary science and engineering area, has been the focus of different fields of research in the past few years. Several microreactors have been developed. Enzymes are a type of catalyst, which are useful in the production of substance in an environmentally friendly way, and they also have high potential for analytical applications. However, not many enzymatic processes have been commercialized, because of problems in stability of the enzymes, cost, and efficiency of the reactions. Thus, there have been demands for innovation in process engineering, particularly for enzymatic reactions, and microreaction devices represent important tools for the development of enzyme processes. In this review, we summarize the recent advances of microchannel reaction technologies especially for enzyme immobilized microreactors. We discuss the manufacturing process of microreaction devices and the advantages of microreactors compared to conventional reaction devices. Fundamental techniques for enzyme immobilized microreactors and important applications of this multidisciplinary technology are also included in our topics.

  20. Technologies for immobilization and disposal of tritium

    International Nuclear Information System (INIS)

    This study was done within a program one of whose objectives was to know the state of the technology development for tritium separation in the moderator circuit at HWR and to define the possible technologies to be applied to the Argentine nuclear power plants. Within this framework the strategies adopted by each country and the available technologies for a safe disposal of tritium, not only in its gaseous state tritium but also as tritiated water were analyzed. It is considered that if the selected separation method is such that the tritium is in its gaseous state, the hydride formation for long periods of immobilization should be studied. whereas if it were triated water immobilization should be studied to choose the technology between cementation and drying agents, in both cases the final disposal site will have to be selected. (author). 8 refs

  1. Immobilization of Polymeric Luminophor on Nanoparticles Surface

    Science.gov (United States)

    Bolbukh, Yuliia; Podkoscielna, Beata; Lipke, Agnieszka; Bartnicki, Andrzej; Gawdzik, Barbara; Tertykh, Valentin

    2016-04-01

    Polymeric luminophors with reduced toxicity are of the priorities in the production of lighting devices, sensors, detectors, bioassays or diagnostic systems. The aim of this study was to develop a method of immobilization of the new luminophor on a surface of nanoparticles and investigation of the structure of the grafted layer. Monomer 2,7-(2-hydroxy-3-methacryloyloxypropoxy)naphthalene (2,7-NAF.DM) with luminophoric properties was immobilized on silica and carbon nanotubes in two ways: mechanical mixing with previously obtained polymer and by in situ oligomerization with chemisorption after carrier's modification with vinyl groups. The attached polymeric (or oligomeric) surface layer was studied using thermal and spectral techniques. Obtained results confirm the chemisorption of luminophor on the nanotubes and silica nanoparticles at the elaborated synthesis techniques. The microstructure of 2,7-NAF.DM molecules after chemisorption was found to be not changed. The elaborated modification approach allows one to obtain nanoparticles uniformly covered with polymeric luminophor.

  2. Glucose oxidase immobilization onto carbon nanotube networking

    CERN Document Server

    Karachevtsev, V A; Zarudnev, E S; Karachevtsev, M V; Leontiev, V S; Linnik, A S; Lytvyn, O S; Plokhotnichenko, A M; Stepanian, S G

    2012-01-01

    When elaborating the biosensor based on single-walled carbon nanotubes (SWNTs), it is necessary to solve such an important problem as the immobilization of a target biomolecule on the nanotube surface. In this work, the enzyme (glucose oxidase (GOX)) was immobilized on the surface of a nanotube network, which was created by the deposition of nanotubes from their solution in 1,2-dichlorobenzene by the spray method. 1-Pyrenebutanoic acid succinimide ester (PSE) was used to form the molecular interface, the bifunctional molecule of which provides the covalent binding with the enzyme shell, and its other part (pyrene) is adsorbed onto the nanotube surface. First, the usage of such a molecular interface leaves out the direct adsorption of the enzyme (in this case, its activity decreases) onto the nanotube surface, and, second, it ensures the enzyme localization near the nanotube. The comparison of the resonance Raman (RR) spectrum of pristine nanotubes with their spectrum in the PSE environment evidences the creat...

  3. Thermoresponsive and bioactive poly(vinyl ether)-based hydrogels synthesized by radiation copolymerization and photochemical immobilization

    International Nuclear Information System (INIS)

    A thermoresponsive hydrogel was synthesized by radiation copolymerization of ethylene glycol vinyl ether (EGVE) and butyl vinyl ether (BVE) in the presence of cross-linking agent diethylene glycol divinyl ether. The gel was modified by a cell adhesion factor RGD by photochemical immobilization technique. While the unmodified hydrogel shows fully hydrated form at low temperatures (+4 oC) and it extensively dehydrates at 37 oC, the biomodified hydrogel still kept its thermoresponsive character after immobilization. The effectiveness of immobilization was checked with FTIR-ATR and XPS. The use of bioactive thermoresponsive hydrogels in cell culture applications was investigated. For this purpose, cell culture experiments were realized by L929 mouse fibroblasts. Cell attachment experiments revealed the effect of immobilized RGD with higher values of cell attachment (∼85%), which were obtained especially in the absence of serum. The thermoresponsive character of the hydrogel was useful for the application of low-temperature treatment in order to recover the attached viable cells from the surface of the hydrogel without using trypsin. When the culture temperature was decreased from 37 to 10 deg. C for 30 min ∼80% of the cells were detached from the hydrogel surface

  4. Combustion synthesis of radioactive waste immobilization

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ruizhu; GUO Zhimeng; LU Xin; JIA Chengchang; LIN Tao

    2005-01-01

    Using chromium oxide (CrO3) as an oxidant, the immobilization of simulating radioactive waste in perovskite (CaTiO3) structure by a combustion synthesis (CS) method was tested. The products were characterized by Archimedes liquid displacement technique, microhardness technique, X-ray diffraction, and scanning electron microscopy. The leaching rate was measured by the method of MCC-1 or MCC-2.The primary results show that the CS method can be used to solidify the immobilizate waste effectively.

  5. Immobilization of Rocky Flats graphite fines residues

    International Nuclear Information System (INIS)

    The Savannah River Technology Center (SRTC) is developing an immobilization process for graphite fines residues generated during nuclear materials production activities at the Rocky Flats Environmental Technology Site (Rocky Flats). The continued storage of this material has been identified as an item of concern. The residue was generated during the cleaning of graphite casting molds and potentially contains reactive plutonium metal. The average residue composition is 73 wt% graphite, 15 wt% calcium fluoride (CaF2), and 12 wt% plutonium oxide (PuO2). Approximately 950 kg of this material are currently stored at Rocky Flats. The strategy of the immobilization process is to microencapsulate the residue by mixing with a sodium borosilicate (NBS) glass frit and heating at nominally 700 C. The resulting waste form would be sent to the Waste Isolation Pilot Plant (WIPP) for disposal. Since the PuO2 concentration in the residue averages 12 wt%, the immobilization process was required to meet the intent of safeguards termination criteria by limiting plutonium recoverability based on a test developed by Rocky Flats. The test required a plutonium recovery of less than 4 g/kg of waste form when a sample was leached using a nitric acid/CaF2 dissolution flowsheet. Immobilization experiments were performed using simulated graphite fines with cerium oxide (CeO2) as a surrogate for PuO2 and with actual graphite fines residues. Small-scale surrogate experiments demonstrated that a 4:1 frit to residue ratio was adequate to prevent recovery of greater than 4 g/kg of cerium from simulated waste forms. Additional experiments investigated the impact of varying concentrations of CaF2 and the temperature/heating time cycle on the cerium recovery. Optimal processing conditions developed during these experiments were subsequently demonstrated at full-scale with surrogate materials and on a smaller scale using actual graphite fines

  6. Immobilization precision of a modified GTC frame.

    Science.gov (United States)

    Winey, Brian; Daartz, Juliane; Dankers, Frank; Bussière, Marc

    2012-01-01

    The purpose of this study was to evaluate and quantify the interfraction reproducibility and intrafraction immobilization precision of a modified GTC frame. The error of the patient alignment and imaging systems were measured using a cranial skull phantom, with simulated, predetermined shifts. The kV setup images were acquired with a room-mounted set of kV sources and panels. Calculated translations and rotations provided by the computer alignment software relying upon three implanted fiducials were compared to the known shifts, and the accuracy of the imaging and positioning systems was calculated. Orthogonal kV setup images for 45 proton SRT patients and 1002 fractions (average 22.3 fractions/patient) were analyzed for interfraction and intrafraction immobilization precision using a modified GTC frame. The modified frame employs a radiotransparent carbon cup and molded pillow to allow for more treatment angles from posterior directions for cranial lesions. Patients and the phantom were aligned with three 1.5 mm stainless steel fiducials implanted into the skull. The accuracy and variance of the patient positioning and imaging systems were measured to be 0.10 ± 0.06 mm, with the maximum uncertainty of rotation being ±0.07°. 957 pairs of interfraction image sets and 974 intrafraction image sets were analyzed. 3D translations and rotations were recorded. The 3D vector interfraction setup reproducibility was 0.13 mm ± 1.8 mm for translations and the largest uncertainty of ± 1.07º for rotations. The intrafraction immobilization efficacy was 0.19 mm ± 0.66 mm for translations and the largest uncertainty of ± 0.50º for rotations. The modified GTC frame provides reproducible setup and effective intrafraction immobilization, while allowing for the complete range of entrance angles from the posterior direction. PMID:22584167

  7. Immobilizing Biomolecules Near the Diffraction Limit

    DEFF Research Database (Denmark)

    Skovsen, Esben; Neves-Petersen, Maria Teresa; Kold, Ane;

    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 ca...... a substrate, which can be generated by a UV diffraction pattern. Such patterns can have sub-micron feature sizes and could therefore be of great relevance for present and future nanotechnological applications....

  8. Uranium Immobilization by Sulfate-reducing Biofilms

    International Nuclear Information System (INIS)

    Hexavalent uranium [U(VI)] was immobilized using biofilms of the sulfate-reducing bacterium (SRB) Desulfovibrio desulfuricans G20. The biofilms were grown in flat-plate continuous-flow reactors using lactate as the electron donor and sulfate as the electron acceptor. U(VI) was continuously fed into the reactor for 32 weeks at a concentration of 126 ?M. During this time, the soluble U(VI) was removed (between 88 and 96% of feed) from solution and immobilized in the biofilms. The dynamics of U immobilization in the sulfate-reducing biofilms were quantified by estimating: (1) microbial activity in the SRB biofilm, defined as the hydrogen sulfide (H2S) production rate and estimated from the H2S concentration profiles measured using microelectrodes across the biofilms; (2) concentration of dissolved U in the solution; and (3) the mass of U precipitated in the biofilm. Results suggest that U was immobilized in the biofilms as a result of two processes: (1) enzymatically and (2) chemically, by reacting with microbially generated H2S. Visual inspection showed that the dissolved sulfide species reacted with U(VI) to produce a black precipitate. Synchrotron-based U L3-edge X-ray absorption near edge structure (XANES) spectroscopy analysis of U precipitated abiotically by sodium sulfide indicated that U(VI) had been reduced to U(IV). Selected-area electron diffraction pattern and crystallographic analysis of transmission electron microscope lattice-fringe images confirmed the structure of precipitated U as being that of uraninite

  9. Utilization of Enzyme-Immobilized Mesoporous Silica Nanocontainers (IBN-4 in Prodrug-Activated Cancer Theranostics

    Directory of Open Access Journals (Sweden)

    Bau-Yen Hung

    2015-12-01

    Full Text Available To develop a carrier for use in enzyme prodrug therapy, Horseradish peroxidase (HRP was immobilized onto mesoporous silica nanoparticles (IBN-4: Institute of Bioengineering and Nanotechnology, where the nanoparticle surfaces were functionalized with 3-aminopropyltrimethoxysilane and further conjugated with glutaraldehyde. Consequently, the enzymes could be stabilized in nanochannels through the formation of covalent imine bonds. This strategy was used to protect HRP from immune exclusion, degradation and denaturation under biological conditions. Furthermore, immobilization of HRP in the nanochannels of IBN-4 nanomaterials exhibited good functional stability upon repetitive use and long-term storage (60 days at 4 °C. The generation of functionalized and HRP-immobilized nanomaterials was further verified using various characterization techniques. The possibility of using HRP-encapsulated IBN-4 materials in prodrug cancer therapy was also demonstrated by evaluating their ability to convert a prodrug (indole-3- acetic acid (IAA into cytotoxic radicals, which triggered tumor cell apoptosis in human colon carcinoma (HT-29 cell line cells. A lactate dehydrogenase (LDH assay revealed that cells could be exposed to the IBN-4 nanocomposites without damaging their membranes, confirming apoptotic cell death. In summary, we demonstrated the potential of utilizing large porous mesoporous silica nanomaterials (IBN-4 as enzyme carriers for prodrug therapy.

  10. Sufentanil citrate immobilization of Alaskan moose calves.

    Science.gov (United States)

    Kreeger, Terry J; Kellie, Kalin A

    2012-10-01

    Free-ranging Alaskan moose calves (Alces alces gigas) were immobilized with 0.12 mg/kg sufentanil (S; n=16), 0.12 mg/kg sufentanil plus 0.27 mg/kg xylazine (SX; n=11), or 0.007 mg/kg carfentanil plus 0.36 mg/kg xylazine (CX; n=13). Immobilants were antagonized with 1.2 mg/kg naltrexone (S) or 1.2 mg/kg naltrexone plus 2.4 mg/kg tolazoline (SX, CX). There were no differences in induction (P ≥ 0.29) or processing (P ≥ 0.44) times between groups. Moose given either S or SX had significantly shorter recovery times than moose given CX (P=0.001) and recovery times from S were shorter than from SX (P=0.02). Oxygen saturation values for all groups averaged 85 ± 8%, but were significantly higher (P=0.048) for CX (89 ± 7%) than for S (82 ± 8%). Based on these data, sufentanil at 0.1 mg/kg or sufentanil at 0.1 mg/kg plus xylazine at 0.25 mg/kg could provide effective remote immobilization for Alaskan moose calves and could be substituted for carfentanil or thiafentanil should the need arise. PMID:23060515

  11. Immobilization of enzyme on a polymer surface

    Science.gov (United States)

    Shen, Lei; Cheng, Kenneth Chun Kuen; Schroeder, McKenna; Yang, Pei; Marsh, E. Neil G.; Lahann, Joerg; Chen, Zhan

    2016-06-01

    We successfully immobilized enzymes onto polymer surfaces via covalent bonds between cysteine groups of the enzyme and dibromomaleimide functionalities present at the polymer surface. In this work, we used nitroreductase (NfsB) as a model enzyme molecule. The polymers were prepared by chemical vapor deposition (CVD) polymerization, resulting in surfaces with dibromomaleimide groups. NfsB variants were engineered so that each NfsB molecule only has one cysteine group on the enzyme surface. Two different NfsB constructs were studied, with cysteines at the positions of H360 and V424, respectively. A combination of sum frequency generation (SFG) vibrational and attenuated total reflectance Fourier transformed infrared (ATR-FTIR) spectroscopies were used to deduce the orientation of the immobilized enzymes on the surface. It was found that the orientation of the immobilized enzymes is controlled by the position of the cysteine residue in the protein. The NfsB H360C construct exhibited a similar orientational behavior on the polymer surface as compared to that on the self-assembled monolayer surface, but the NsfB V424C construct showed markedly different orientations on the two surfaces.

  12. Immobilization of mycoplana sp. MVMB2 isolated from petroleum contaminated soil onto papaya stem (carica papaya l.) and its application on degradation of phenanthrene

    International Nuclear Information System (INIS)

    This study presents the degradation of phenanthrene using immobilized Mycoplana sp. MVMB2 isolated from contaminated soil. Papaya stem pretreated by two stage processes, treating with acid or alkali and drying, was used for the immobilization of Mycoplana sp. Alkali pretreated papaya stem was found to be most effective in cell uptake compared to acid treated one. The maximum immobilization capacity at various physiochemical conditions for the alkali pretreated papaya stem was found to be at 320 min time, pH 6.5, 30 C temperature, and 18.6 x 106 cells/mL initial concentrations. The adsorption mechanism of Mycoplana sp. MVMB2 on pretreated papaya stem was assessed using various kinetic and isotherm models. The immobilization of Mycoplana sp. MVMB2 on to pretreated papaya stem was corroborated by scanning electron microscopy and Fourier transformed IR spectroscopy analysis. The performance of immobilized cells in batch reactor showed more than 95% phenanthrene degradation within 72 h, whereas, free cells were found to require 120 h. The immobilized cells also showed better degradation performance in the packed column study. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  13. Immobilization of mycoplana sp. MVMB2 isolated from petroleum contaminated soil onto papaya stem (carica papaya l.) and its application on degradation of phenanthrene

    Energy Technology Data Exchange (ETDEWEB)

    Brinda Lakshmi, Mahalingam; Muthukumar, Karuppan; Velan, Manickam [Environmental Biotechnology Laboratory, Department of Chemical Engineering, A.C. College of Technology, Anna University, Chennai (India)

    2012-08-15

    This study presents the degradation of phenanthrene using immobilized Mycoplana sp. MVMB2 isolated from contaminated soil. Papaya stem pretreated by two stage processes, treating with acid or alkali and drying, was used for the immobilization of Mycoplana sp. Alkali pretreated papaya stem was found to be most effective in cell uptake compared to acid treated one. The maximum immobilization capacity at various physiochemical conditions for the alkali pretreated papaya stem was found to be at 320 min time, pH 6.5, 30 C temperature, and 18.6 x 10{sup 6} cells/mL initial concentrations. The adsorption mechanism of Mycoplana sp. MVMB2 on pretreated papaya stem was assessed using various kinetic and isotherm models. The immobilization of Mycoplana sp. MVMB2 on to pretreated papaya stem was corroborated by scanning electron microscopy and Fourier transformed IR spectroscopy analysis. The performance of immobilized cells in batch reactor showed more than 95% phenanthrene degradation within 72 h, whereas, free cells were found to require 120 h. The immobilized cells also showed better degradation performance in the packed column study. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  14. The effectiveness of immobilization during prostate irradiation

    International Nuclear Information System (INIS)

    Purpose: To evaluate the effect of a hemibody foam cradle on the reproducibility of patient setup during external beam radiation treatment of prostate cancer. Methods and Materials: Between January 1992 and April 1993, 74 patients received external beam radiation treatment to the prostate ± nodes, generally with a four-field box technique. Forty-four of the 74 patients had a custom-made hemibody foam cast used in an attempt to improve setup accuracy. A review of the routine weekly port films was performed following the completion of therapy to determine the reproducibility of patient setup in all 74 patients. The physician's request of an isocenter shift was used as an indicator of reproducibility. Neither the treating technologists nor the physicians knew at the time the films were taken that the port films would be reviewed for setup reproducibility at a later date. The results were compared between the patients treated with (44) and without (30) an immobilization device. Results: In the 44 immobilized patients, 213 routine checks of the isocenter were performed during the 7-week course of radiation therapy. In 17.4% of these instances (37 out of 213), an isocenter shift was requested. This rate is compared to 23.1% (30 out of 130) in the 30 patients who did not have the immobilization device (p < 0.2). There was a statistically significant reduction in isocenter shifts requested in the anterior to posterior direction in the patients who were immobilized, 5.1% (9 out of 175) vs. 12.6% (13 out of 103) (p < 0.05, two tailed chi-square test). There was no significant improvement in the reproducibility of isocenter placement in the cephalad to caudal or right to left directions. Conclusions: This custom-made hemibody foam cradle appears to improve the reproducibility of patient setup during the 7-week course of fractionated external beam irradiation for patients with adenocarcinoma of the prostate. This type of immobilization device is now routinely used in our

  15. Co-immobilization of glucose oxidase and xylose dehydrogenase displayed whole cell on multiwalled carbon nanotube nanocomposite films modified electrode for simultaneous voltammetric detection of D-glucose and D-xylose.

    Science.gov (United States)

    Li, Liang; Liang, Bo; Li, Feng; Shi, Jianguo; Mascini, Marco; Lang, Qiaolin; Liu, Aihua

    2013-04-15

    In this paper, we first report the construction of Nafion/glucose oxidase (GOD)/xylose dehydrogenase displayed bacteria (XDH-bacteria)/multiwalled carbon nanotubes (MWNTs) modified electrode for simultaneous voltammetric determination of D-glucose and D-xylose. The optimal conditions for the immobilized enzymes were established. Both enzymes retained their good stability and activities. In the mixture solution of D-glucose and D-xylose containing coenzyme NAD⁺ (the oxidized form of nicotinamide adenine dinucleotide), the Nafion/GOD/XDH-bacteria/MWNTs modified electrode exhibited quasi-reversible oxidation-reduction peak at -0.5 V (vs. saturated calomel electrode, SCE) originating from the catalytic oxidation of D-glucose, and oxidation peak at +0.55 V(vs. SCE) responding to the oxidation of NADH (the reduced form of nicotinamide adenine dinucleotide) by the carbon nanotubes, where NADH is the resultant product of coenzyme NAD⁺ involved in the catalysis of D-xylose by XDH-displayed bacteria. For the proposed biosensor, cathodic peak current at -0.5 V was linear with the concentration of D-glucose within the range of 0.25-6 mM with a low detection limit of 0.1 mM D-glucose (S/N=3), and the anodic peak current at +0.55 V was linear with the concentration of d-xylose in the range of 0.25∼4 mM with a low detection limit of 0.1 mM D-xylose (S/N=3). Further, D-xylose and D-glucose did not interfere with each other. 300-fold excess saccharides including D-maltose, D-galactose, D-mannose, D-sucrose, D-fructose, D-cellobiose, and 60-fold excess L-arabinose, and common interfering substances (100-fold excess ascorbic acid, dopamine, uric acid) as well as 300-fold excess D-xylitol did not affect the detection of D-glucose and D-xylose (both 1 mM). Therefore, the proposed biosensor is stable, specific, reproducible, simple, rapid and cost-effective, which holds great potential in real applications. PMID:23202346

  16. 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

  17. Lipase immobilization and production of fatty acid methyl esters from canola oil using immobilized lipase

    International Nuclear Information System (INIS)

    Lipase enzyme from Aspergillus oryzae (EC 3.1.1.3) was immobilized onto a micro porous polymeric matrix which contains aldehyde functional groups and methyl esters of long chain fatty acids (biodiesel) were synthesized by transesterification of crude canola oil using immobilized lipase. Micro porous polymeric matrix was synthesized from styrene-divinylbenzene (STY-DVB) copolymers by using high internal phase emulsion technique and two different lipases, Lipozyme TL-100L® and Novozym 388®, were used for immobilization by both physical adsorption and covalent attachment. Biodiesel production was carried out with semi-continuous operation. Methanol was added into the reactor by three successive additions of 1:4 M equivalent of methanol to avoid enzyme inhibition. The transesterification reaction conditions were as follows: oil/alcohol molar ratio 1:4; temperature 40 oC and total reaction time 6 h. Lipozyme TL-100L® lipase provided the highest yield of fatty acid methyl esters as 92%. Operational stability was determined with immobilized lipase and it indicated that a small enzyme deactivation occurred after used repeatedly for 10 consecutive batches with each of 24 h. Since the process is yet effective and enzyme does not leak out from the polymer, the method can be proposed for industrial applications. -- Research highlights: → Lipozyme TL-100L and Novozym 388 were immobilized onto micro porous polymeric matrix by both physical adsorption and covalent linking. → Immobilized enzymes were used for synthesis of fatty acid methyl esters by transesterification of canola oil and methanol using semi-continuous operation system. → According to chromatographic analysis, Lipase Lipozyme TL-100L resulted in the highest yield of methyl ester as 92%.

  18. Endothelialization of polyurethanes: Surface silanization and immobilization of REDV peptide.

    Science.gov (United States)

    Butruk-Raszeja, Beata A; Dresler, Magdalena S; Kuźmińska, Aleksandra; Ciach, Tomasz

    2016-08-01

    The paper presents method for chemical immobilization of arginine-glutamic acid-aspartic acid-valine (REDV) peptide on polyurethane surface. The peptide has been covalently bonded using silanes as a spacer molecules. The aim of this work was to investigate the proposed modification process and assess its biological effectiveness, especially in contact with blood and endothelial cells. Physicochemical properties were examined in terms of wettability, atomic composition and density of introduced functional groups and peptide molecules. Experiments with blood showed that material coating reduced number of surface-adhered platelets and fibrinogen molecules. In contrast to polyurethane (PU), there were no blood components deposited on REDV-modified materials (PU-REDV); fibrinogen adsorption on PU-REDV surface has been strongly reduced compared to PU. Analysis of cell adhesion after 1, 2, 3, 4, and 5 days of culture showed a significant increase of the cell-coated area on PU-REDV compared to PU. However, an intense cell growth appeared also on the control surface modified without the addition of REDV. Thus, the positive effect of REDV peptide on the adhesion of HUVEC could not be unequivocally confirmed. PMID:27110909

  19. Activation of accumulated nitrite reduction by immobilized Pseudomonas stutzeri T13 during aerobic denitrification.

    Science.gov (United States)

    Ma, Fang; Sun, Yilu; Li, Ang; Zhang, Xuening; Yang, Jixian

    2015-01-01

    The excellent removal efficiency of nitrate by the aerobic denitrifier, Pseudomonas stutzeri T13, was achieved in free cells system. However, poor nitrite reduction prevents efficient aerobic denitrification because of the nitrite accumulation. This problem could be conquered by immobilizing the cells on supports. In this study, strain T13 was immobilized by mycelial pellets (MPs), polyurethane foam cubes (PFCs) and sodium alginate beads (SABs). Higher removal percentages of TN in MP (43.78%), PFC (42.31%) and SAB (57.25%) systems were achieved compared with the free cell system (29.7%). Furthermore, the optimal condition for immobilized cell systems was as follows: 30°C, 100rpm shaking speed and pH 7. The shock-resistance of SAB system was relatively poor, which could collapse under either alkaline (pH=9) or high rotating (200rpm) conditions. The recycling experiments demonstrated that the high steady TN removal rate could be maintained for seven cycles in both MP and PFC systems. PMID:25827250

  20. Immobilization and release strategies for DNA delivery using carbon nanofiber arrays and self-assembled monolayers

    Energy Technology Data Exchange (ETDEWEB)

    Peckys, Diana B [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6030 (United States); Melechko, Anatoli V [Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC 27695 (United States); Simpson, Michael L [University of Tennessee in Knoxville, Knoxville, TN 37996-2200 (United States); McKnight, Timothy E [Measurement Science and Systems Engineering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6006 (United States)], E-mail: peckysdb@ornl.gov

    2009-04-08

    We report a strategy for immobilizing dsDNA (double-stranded DNA) onto vertically aligned carbon nanofibers and subsequently releasing this dsDNA following penetration and residence of these high aspect ratio structures within cells. Gold-coated nanofiber arrays were modified with self-assembled monolayers (SAM) to which reporter dsDNA was covalently and end-specifically bound with or without a cleavable linker. The DNA-modified nanofiber arrays were then used to impale, and thereby transfect, Chinese hamster lung epithelial cells. This mechanical approach enables the transport of bound ligands directly into the cell nucleus and consequently bypasses extracellular and cytosolic degradation. Statistically significant differences were observed between the expression levels from immobilized and releasable DNA, and these are discussed in relation to the distinct accessibility and mode of action of glutathione, an intracellular reducing agent responsible for releasing the bound dsDNA. These results prove for the first time that an end-specifically and covalently SAM-bound DNA can be expressed in cells. They further demonstrate how the choice of immobilization and release methods can impact expression of nanoparticle delivered DNA.

  1. Immobilization and release strategies for DNA delivery using carbon nanofiber arrays and self-assembled monolayers

    International Nuclear Information System (INIS)

    We report a strategy for immobilizing dsDNA (double-stranded DNA) onto vertically aligned carbon nanofibers and subsequently releasing this dsDNA following penetration and residence of these high aspect ratio structures within cells. Gold-coated nanofiber arrays were modified with self-assembled monolayers (SAM) to which reporter dsDNA was covalently and end-specifically bound with or without a cleavable linker. The DNA-modified nanofiber arrays were then used to impale, and thereby transfect, Chinese hamster lung epithelial cells. This mechanical approach enables the transport of bound ligands directly into the cell nucleus and consequently bypasses extracellular and cytosolic degradation. Statistically significant differences were observed between the expression levels from immobilized and releasable DNA, and these are discussed in relation to the distinct accessibility and mode of action of glutathione, an intracellular reducing agent responsible for releasing the bound dsDNA. These results prove for the first time that an end-specifically and covalently SAM-bound DNA can be expressed in cells. They further demonstrate how the choice of immobilization and release methods can impact expression of nanoparticle delivered DNA.

  2. Design of a papain immobilized antimicrobial food package with curcumin as a crosslinker.

    Directory of Open Access Journals (Sweden)

    Cynthya Maria Manohar

    Full Text Available Contamination of food products by spoilage and pathogenic microorganisms during post process handling is one of the major causes for food spoilage and food borne illnesses. The present green sustainable approach describes the covalent immobilization of papain to LDPE (low density polyethylene, HDPE (high density polyethylene, LLDPE (linear low density polyethylene and PCL (polycaprolactam with curcumin as the photocrosslinker. About 50% of curcumin and 82-92% of papain were successfully immobilized on these polymers. After 30 days, the free enzyme retained 87% of its original activity, while the immobilized enzyme retained more than 90% of its activity on these polymers. Papain crosslinked to LLDPE exhibited the best antibiofilm properties against Acinetobacter sp. KC119137.1 and Staphylococcus aureus NCIM 5021 when compared to the other three polymers, because of the highest amount of enzyme immobilized on this surface. Papain acts by damaging the cell membrane. The enzyme is able to reduce the amount of carbohydrate and protein contents in the biofilms formed by these organisms. Meat wrapped with the modified LDPE and stored at 4°C showed 9 log reduction of these organisms at the end of the seventh day when compared to samples wrapped with the bare polymer. This method of crosslinking can be used on polymers with or without functional groups and can be adopted to bind any type of antimicrobial agent.

  3. 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.

  4. Design of a papain immobilized antimicrobial food package with curcumin as a crosslinker.

    Science.gov (United States)

    Manohar, Cynthya Maria; Prabhawathi, Veluchamy; Sivakumar, Ponnurengam Malliappan; Doble, Mukesh

    2015-01-01

    Contamination of food products by spoilage and pathogenic microorganisms during post process handling is one of the major causes for food spoilage and food borne illnesses. The present green sustainable approach describes the covalent immobilization of papain to LDPE (low density polyethylene), HDPE (high density polyethylene), LLDPE (linear low density polyethylene) and PCL (polycaprolactam) with curcumin as the photocrosslinker. About 50% of curcumin and 82-92% of papain were successfully immobilized on these polymers. After 30 days, the free enzyme retained 87% of its original activity, while the immobilized enzyme retained more than 90% of its activity on these polymers. Papain crosslinked to LLDPE exhibited the best antibiofilm properties against Acinetobacter sp. KC119137.1 and Staphylococcus aureus NCIM 5021 when compared to the other three polymers, because of the highest amount of enzyme immobilized on this surface. Papain acts by damaging the cell membrane. The enzyme is able to reduce the amount of carbohydrate and protein contents in the biofilms formed by these organisms. Meat wrapped with the modified LDPE and stored at 4°C showed 9 log reduction of these organisms at the end of the seventh day when compared to samples wrapped with the bare polymer. This method of crosslinking can be used on polymers with or without functional groups and can be adopted to bind any type of antimicrobial agent. PMID:25906061

  5. Immobilized synthetic pathway for biodegradation of toxic recalcitrant pollutant 1,2,3-trichloropropane.

    Science.gov (United States)

    Dvorak, Pavel; Bidmanova, Sarka; Damborsky, Jiri; Prokop, Zbynek

    2014-06-17

    The anthropogenic compound 1,2,3-trichloropropane (TCP) has recently drawn attention as an emerging groundwater contaminant. No living organism, natural or engineered, is capable of the efficient aerobic utilization of this toxic industrial waste product. We describe a novel biotechnology for transforming TCP based on an immobilized synthetic pathway. The pathway is composed of three enzymes from two different microorganisms: engineered haloalkane dehalogenase from Rhodococcus rhodochrous NCIMB 13064, and haloalcohol dehalogenase and epoxide hydrolase from Agrobacterium radiobacter AD1. Together, they catalyze consecutive reactions converting toxic TCP to harmless glycerol. The pathway was immobilized in the form of purified enzymes or cell-free extracts, and its performance was tested in batch and continuous systems. Using a packed bed reactor filled with the immobilized biocatalysts, 52.6 mmol of TCP was continuously converted into glycerol within 2.5 months of operation. The efficiency of the TCP conversion to the intermediates was 97%, and the efficiency of conversion to the final product glycerol was 78% during the operational period. Immobilized biocatalysts are suitable for removing TCP from contaminated water up to a 10 mM solubility limit, which is an order of magnitude higher than the concentration tolerated by living microorganisms. PMID:24787668

  6. A whisker-like carbon composite for the immobilization of laccase and its bioelectrochemistry

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A novel mesoporous carbon/whisker-like carbon (MCWC) composite was used for the immobilization of laccase (Lac) and its bioelectrochemical behaviors were studied.It was confirmed by XPS that Lac was strongly adsorbed on the surface of the MCWC composite.The cyclic voltammetric results showed that the immobilized Lac underwent a direct quasi-reversible electrochemical reaction.The value of the electron transfer rate constant ks was estimated to be 0.770 s-1,indicating a reasonably fast electron transfer between the immobilized Lac and the underlying electrode.The surface concentration (I-) of Lac was estimated to be 2.730 × 10-12 mol/cm2.Further experimental results showed that the immobilized Lac displayed an appreciable electrocatalytic activity to the electrochemical reduction of O2.These properties could be attributed to the particular structure of loosely packed nanometer-scale carbon whiskers and the existence of a large amount of oxygen-containing groups.The immo- bilization method and the novel carrier (MCWC) may find new applications in fabricating the biocatalysts for biofuel cells.

  7. Chromium immobilization by extra- and intraradical fungal structures of arbuscular mycorrhizal symbioses.

    Science.gov (United States)

    Wu, Songlin; Zhang, Xin; Sun, Yuqing; Wu, Zhaoxiang; Li, Tao; Hu, Yajun; Lv, Jitao; Li, Gang; Zhang, Zhensong; Zhang, Jing; Zheng, Lirong; Zhen, Xiangjun; Chen, Baodong

    2016-10-01

    Arbuscular mycorrhizal (AM) fungi can enhance plant Cr tolerance through immobilizing Cr in mycorrhizal roots. However, the detailed processes and mechanisms are unclear. The present study focused on cellular distribution and speciation of Cr in both extraradical mycelium (ERM) and mycorrhizal roots exposed to Cr(VI) by using field emission scanning electron microscopy equipped with energy dispersive X-ray spectrometer (FE-SEM-EDS), scanning transmission soft X-ray microscopy (STXM) and X-ray absorption fine structure (XAFS) spectroscopy techniques. We found that amounts of particles (possibly extracellular polymeric substances, EPS) were produced on the AM fungal surface upon Cr(VI) stress, which contributed greatly to Cr(VI) reduction and immobilization. With EDS of the surface of AM fungi exposed to various Cr(VI) levels, a positive correlation between Cr and P was revealed, suggesting that phosphate groups might act as counter ions of Cr(III), which was also confirmed by the XAFS analysis. Besides, STXM and XAFS analyses showed that Cr(VI) was reduced to Cr(III) in AM fungal structures (arbuscules, intraradical mycelium, etc.) and cell walls in mycorrhizal roots, and complexed possibly with carboxyl groups or histidine analogues. The present work provided evidence of Cr immobilization on fungal surface and in fungal structures in mycorrhizal roots at a cellular level, and thus unraveled the underlying mechanisms by which AM symbiosis immobilize Cr. PMID:27209517

  8. 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.

  9. Immobilization of fish chromatophores for use as a micro-biosensor for biological toxins

    Directory of Open Access Journals (Sweden)

    Mojović Ljiljana V.

    2003-01-01

    Full Text Available Chromatophores isolated from the Siamese fighting fish, Betta splendens represent a class of living cells that provide a vivid color response to microbial pathogens and environmental toxins. The selection of the most appropriate microcarrier and the development of the optimal technique for the chromatophore immobilization in order to enable directed transport of the sensor cells throughout microchannels of the biosensor, as well to preserve the cell survival and its functionality was studied. Microcarriers derived from glass, polystyrene and gelatin (collagen were tested as substrates for chromatophore attachement. Gelatin microcarriers were found to be the most suitable, due to high attachment efficiency (95% of attached cells, preservation of the cell viability and enhanced cell sensitivity. The optimum conditions for fish cell immobilization on collagen microcarriers were determined based on the cell-to-microcarrier bead ratio and the pH of the solution. The rate of cell attachment to the gelatin microcarrier followed first-order kinetics. Pretreatment of the gelatin beads with fibronectin, known as a cell attachment-promoting agent, resulted in a 10% higher attachment rate constant (k.

  10. Immobilization of activated sludge using improved polyvinyl alcohol (PVA) gel

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The microbial immobilization method using polyvinyl alcohol (PVA) gel as an immobilizing material was improved and used for entrapment of activated sludge. The OUR (oxygen uptake rate) was used to characterize the biological activity of immobilized activated sludge. Three kinds of PVA-immobilized particles of activated sludge, that is, PVA-boric acid beads, PVA-sodium nitrate beads and PVA-orthophosphate beads was prepared, and their biological activity was compared by measuring the OUR value. The bioactivity of both autotrophic and heterotrophic microorganisms of activated sludge was determined using different synthetic wastewater media (containing 250 mg/L COD and 25 mg/L NH4+-N). The experimental results showed that the bioactivity and stability of the three kinds of immobilized activated sludge was greatly improved after activation. With respect of the bioactivity and the mechanical stability, the PVA-orthophosphate method may be a promising and economical technique for microbial immobilization.

  11. Covalent immobilization of Pseudomonas cepacia lipase on semiconducting materials

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, Renny Edwin [Microelectronics and MEMS Laboratory, Department of Electrical Engineering, Indian Institute of Technology Madras, Chennai (India)], E-mail: rennyedwin@gmail.com; Bhattacharya, Enakshi [Microelectronics and MEMS Laboratory, Department of Electrical Engineering, Indian Institute of Technology Madras, Chennai (India)], E-mail: enakshi@ee.iitm.ac.in; Chadha, Anju [Department of Biotechnology, National Centre for Catalysis Research, Indian Institute of Technology Madras, Chennai (India)], E-mail: anjuc@iitm.ac.in

    2008-05-30

    Lipase from Pseudomonas cepacia was covalently immobilized on crystalline silicon, porous silicon and silicon nitride surfaces. The various stages of immobilization were characterized using FTIR (Fourier transform infrared) spectroscopy. The surface topography of the enzyme immobilized surfaces was investigated using scanning electron microscopy (SEM). The quantity of the immobilized active enzyme was estimated by the para-nitrophenyl palmitate (pNPP) assay. The immobilized lipase was used for triglyceride hydrolysis and the acid produced was detected by a pH sensitive silicon nitride surface as a shift in the C-V (capacitance-voltage) characteristics of an electrolyte-insulator-semiconductor capacitor (EISCAP) thus validating the immobilization method for use as a biosensor.

  12. 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......-acyl-CoA-dehydrogenase in the vastus lateralis muscle by 9 and 14%, respectively, and thigh volume by 5%. After 7 days of immobilization, a two-step euglycemic hyperinsulinemic clamp procedure combined with arterial and bilateral femoral venous catheterization was performed. Insulin action on glucose uptake and tyrosine...... release of the thighs at mean plasma insulin concentrations of 67 (clamp step I) and 447 microU/ml (clamp step II) was decreased by immobilization, whereas immobilization did not affect insulin action on thigh exchange of free fatty acids, glycerol, O2, or potassium. Before and during the clamp step I...

  13. The immobilization of lipase on PVDF-co-HFP membrane

    Science.gov (United States)

    Kayhan, Naciye; Eyüpoǧlu, Volkan; Adem, Şevki

    2016-04-01

    Lipase is an enzyme having a lot of different industrial applications such as biodiesel production, biopolymer synthesis, enantiopure pharmaceutical productions, agrochemicals, etc. Its immobilized form on different substances is more conventional and useful than its free form. Supporting material was prepared using PVDF-co-HFP in laboratory conditions and attached 1,4-diaminobutane (DA) and epichlorohydrin (EPI) ligands to the membrane to immobilize lipase enzyme. The immobilization conditions such as enzyme amount, pH, the concentration of salt, thermal stability and activity were stabilized for our experimental setup. Then, biochemical characterizations were performed on immobilized lipase PVDF-co-HFP regarding optimal pH activity, temperature and thermal stability. Also, the desorption ratios of immobilized enzyme in two different pathway were investigated to confirm immobilization stability for 24 hours.

  14. Covalent immobilization of Pseudomonas cepacia lipase on semiconducting materials

    International Nuclear Information System (INIS)

    Lipase from Pseudomonas cepacia was covalently immobilized on crystalline silicon, porous silicon and silicon nitride surfaces. The various stages of immobilization were characterized using FTIR (Fourier transform infrared) spectroscopy. The surface topography of the enzyme immobilized surfaces was investigated using scanning electron microscopy (SEM). The quantity of the immobilized active enzyme was estimated by the para-nitrophenyl palmitate (pNPP) assay. The immobilized lipase was used for triglyceride hydrolysis and the acid produced was detected by a pH sensitive silicon nitride surface as a shift in the C-V (capacitance-voltage) characteristics of an electrolyte-insulator-semiconductor capacitor (EISCAP) thus validating the immobilization method for use as a biosensor

  15. Invertase immobilization onto radiation-induced graft copolymerized polyethylene pellets

    International Nuclear Information System (INIS)

    The graft polymer poly(ethylene-g-acrylic acid) (LDPE-g-AA) was prepared by radiation-induced graft copolymerization of acrylic acid onto low density polyethylene (LDPE) pellets, and characterized by infrared photoacoustic spectroscopy and scanning electron microscopy (SEM). The presence of the grafted poly(acrylic acid) (PAA) was established. Invertase was immobilized onto the graft polymer and the thermodynamic parameters of the souble and immobilized enzyme were determined. The Michaelis constant, Km, and the maximum reaction velocity, Vmax, were determined for the free and the immobilized invertase. The Michaelis constant, Km was larger for the immobilized invertase than for the free enzyme, whereas Vmax, was smaller for the immobilized invertase. The thermal stability of the immobilized invertase was higher than that of the free enzyme. (Author)

  16. Mapping and identification of HeLa cell proteins separated by immobilized pH-gradient two-dimensional gel electrophoresis and construction of a two-dimensional polyacrylamide gel electrophoresis database

    DEFF Research Database (Denmark)

    Shaw, AC; Rossel Larsen, M; Roepstorff, P; Holm, A; Christiansen, Gunna; Birkelund, Svend

    1999-01-01

    The HeLa cell line, a human adenocarcinoma, is used in many research fields, since it can be infected with a wide range of viruses and intracellular bacteria. Therefore, the mapping of HeLa cell proteins is useful for the investigation of parasite host cell interactions. Because of the recent imp...... and future data accessible for interlaboratory comparison, we constructed a 2-D PAGE database on the World Wide Web....... mapping of [35S]methionine/cysteine-labeled HeLa cell proteins with the 2-D PAGE (IPG)-system, using matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS) and N-terminal sequencing for protein identification. To date 21 proteins have been identified and mapped. In order to make these...

  17. Ex vivo model of an immobilized-enzyme reactor.

    OpenAIRE

    Bernstein, H; Langer, R

    1988-01-01

    Immobilized-enzyme reactors are beginning to be studied for a variety of therapeutic applications. To facilitate the design of these devices for different clinical situations and a diverse patient population, mathematical models may be valuable. An immobilized-heparinase (EC 4.2.2.7) reactor was selected as a model system. The device removes heparin from blood that has been anticoagulated to prevent thrombus formation. Heparinase was immobilized to cross-linked agarose particles. A mathematic...

  18. Limb immobilization alters functional electrophysiological parameters of sciatic nerve

    OpenAIRE

    J.S.M. Alves; J.H. Leal-Cardoso; F.F.U. Santos-Junior; Carlos, P.S.; Silva, R. C.; Lucci, C.M.; S. N. BAO; Ceccatto, V.M.; R. Barbosa

    2013-01-01

    Immobilization, used in clinical practice to treat traumatologic problems, causes changes in muscle, but it is not known whether changes also occur in nerves. We investigated the effects of immobilization on excitability and compound action potential (CAP) and the ultrastructure of the rat sciatic nerve. Fourteen days after immobilization of the right leg of adult male Wistar rats (n=34), animals were killed and the right sciatic nerve was dissected and mounted in a moist chamber. Nerves were...

  19. Repeated-Batch Ethanol Production from Sweet Sorghum Juice by Saccharomyces cerevisiae Immobilized on Sweet Sorghum Stalks

    Directory of Open Access Journals (Sweden)

    Prasit Jaisil

    2012-04-01

    Full Text Available Sweet sorghum stalks were used as a low cost carrier for immobilization of Saccharomyces cerevisiae NP 01 to produce ethanol from sweet sorghum juice. The effects on ethanol production of carrier size (6 × 6 × 6 to 20 × 20 × 20 mm3 and initial cell concentrations (5 × 107 to 2 × 108 cells mL−1 for cell immobilization were investigated. The ethanol production medium was the juice containing 230 g L−1 of total sugar without nutrient supplementation. The fermentations were carried out under static conditions in 500-mL air-locked Erlenmeyer flasks at 30 °C. The results showed that the optimum size of sorghum stalk pieces for repeated-batch ethanol production was 6 × 6 × 6 mm3, while the optimum initial cell concentration for the immobilization was 1.0 × 108 cells mL−1. The immobilized yeast under these conditions could be used for at least eight successive batches without any losses of ethanol production efficiencies. The average ethanol concentration, productivity and yield of the eight successive batches were 99.28 ± 3.53 g L−1, 1.36 ± 0.05 g L−1 h−1 and 0.47 ± 0.03 g g−1, respectively.

  20. Increase in stability of cellulase immobilized on functionalized magnetic nanospheres

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Wenjuan [Department of Machine Intelligence and Systems Engineering, Faculty of Systems Engineering, Akita Prefectural University, Akita 015-0055 (Japan); Qiu, Jianhui, E-mail: qiu@akita-pu.ac.jp [Department of Machine Intelligence and Systems Engineering, Faculty of Systems Engineering, Akita Prefectural University, Akita 015-0055 (Japan); Feng, Huixia [College of Petrochemical Engineering, Lanzhou University of Technology, Lanzhou 730050 (China); Zang, Limin; Sakai, Eiichi [Department of Machine Intelligence and Systems Engineering, Faculty of Systems Engineering, Akita Prefectural University, Akita 015-0055 (Japan)

    2015-02-01

    Functionalized magnetic nanospheres were prepared by co-condensation of tetraethylorthosilicate with three different amino-silanes: 3-(2-aminoethylamino propyl)-triethoxysilane (AEAPTES), 3-(2-aminoethylamino propyl)-trimethoxysilane (AEAPTMES) and 3-aminopropyltriethoxysilane (APTES). Then three functionalized magnetic nanospheres were used as supports for immobilization of cellulase. The three functionalized magnetic nanospheres with core–shell morphologies exhibited higher capacity for cellulase immobilization than unfunctionalized magnetic nanospheres. The increasing of surface charge of functionalized magnetic nanospheres leads to an enhancement of the capacity of cellulase immobilization. Particularly, AEAPTMES with methoxy groups was favored to be hydrolyzed and grafted on unfunctionalized magnetic nanospheres than the others. AEAPTMES functionalized magnetic nanospheres with the highest zeta potential (29 mV) exhibited 87% activity recovery and the maximum amount of immobilized cellulase was 112 mg/g support at concentration of initial cellulase of 8 mg/mL. Immobilized cellulase on AEAPTMES functionalized magnetic nanospheres had higher temperature stability and broader pH stability than other immobilized cellulases and free cellulase. In particular, it can be used in about 40 °C, demonstrating the potential of biofuel production using this immobilized cellulase. - Highlights: • Three Amino-silane modified magnetic nanospheres were prepared. • Cellulase immobilized AEAPTMES functionalized magnetic nanospheres had higher temperature stability and broader pH stability than free cellulase. • The potential of biofuel production using this immobilized cellulase.

  1. Non-Covalent Immobilization of Quince (Cydonia Oblonga) Polyphenol Oxidase

    OpenAIRE

    YAĞAR, Hülya; Sağiroğlu, Ayten

    2002-01-01

    A partially purified polyphenol oxidase from quince (Cydonia oblonga) was immobilized on bentonite by simple adsorption at pH 6.8. The properties of the immobilized enzyme were compared to those of the free enzyme. Optimum pH and temperature were determined to be 9.0 and 45°C, respectively, showing the alteration of pH and temperature profiles by immobilization. No drastic change was observed in the Km value after immobilization. Catechol, L-DOPA, p-cresole and pyrogallol were tes...

  2. 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

  3. Application of magnetic nanoparticles in smart enzyme immobilization.

    Science.gov (United States)

    Vaghari, Hamideh; Jafarizadeh-Malmiri, Hoda; Mohammadlou, Mojgan; Berenjian, Aydin; Anarjan, Navideh; Jafari, Nahideh; Nasiri, Shahin

    2016-02-01

    Immobilization of enzymes enhances their properties for efficient utilization in industrial processes. Magnetic nanoparticles, due to their high surface area, large surface-to-volume ratio and easy separation under external magnetic fields, are highly valued. Significant progress has been made to develop new catalytic systems that are immobilized onto magnetic nanocarriers. This review provides an overview of recent developments in enzyme immobilization and stabilization protocols using this technology. The current applications of immobilized enzymes based on magnetic nanoparticles are summarized and future growth prospects are discussed. Recommendations are also given for areas of future research. PMID:26472272

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

    OpenAIRE

    Shafei, M. S.; Allam, R F

    2010-01-01

    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 concentra...

  5. Immobilization patterns and dynamics of acetate-utilizing methanogens immobilized in sterile granular sludge in upflow anaerobic sludge blanket reactors

    DEFF Research Database (Denmark)

    Schmidt, Jens Ejbye; Ahring, Birgitte Kiær

    1999-01-01

    Sterile granular sludge was inoculated with either Methanosarcina mazeii S-6, Methanosaeta concilii GP-6, or both species in acetate-fea upflow anaerobic sludge blanket (UASB) reactors to investigate the immobilization patterns and dynamics of aceticlastic methanogens in granular sludge. After...... several months of reactor operation, the methanogens were immobilized, either separately or together. The fastest immobilization was observed in the reactor containing ill. mazeii S-6. The highest effluent concentration of acetate was observed in the reactor with only ill. mazeii S-6 immobilized, while...... the lowest effluent concentration of acetate was observed in the reactor where both types of methanogens were immobilized together. No changes were observed in the kinetic parameters (K-s and mu(max)) of immobilized M. concilii GP-6 or ill, mazeii S-6 compared with suspended cultures, indicating...

  6. Immobilization of degradative bacteria in polyurethane-based foams: embedding efficiency and effect on bacterial activity

    Energy Technology Data Exchange (ETDEWEB)

    Wilde, E.W. [Westinghouse Savannah River Company, Aiken, SC (United States); Radway, J.C.; Hazen, T.C.; Hermann, P. [Matrix R and D Corp., Dover, NH (United States)

    1996-09-03

    The immobilization of TCE-degrading bacterium Burkholderia cepacia was evaluated using hydrophilic polyurethane foam. The influence of several foam formulation parameters upon cell retention was examined. Surfactant type was a major determinant of retention, with a lecithin- based compound retaining more cells than pluronic or silicone based surfactants. Excessive amounts of surfactant led to increased washout of bacteria. Increasing the biomass concentration from 4.8% to 10.5% caused fewer cells to be washed out. Embedding at reduced temperature did not significantly affect retention, while the use of a silane binding agent gave inconsistent results. The optimal formulation retained all but 0.2% of total embedded cells during passage of 2 liters of water through columns containing 2 g of foam. All foam formulations tested reduced the culturability of embedded cells by several orders of magnitude. However, O{sub 2} and CO{sub 2} evolution rates of embedded cells were never less than 50% of unembedded cells. Nutrient amendments stimulated an increase in cell volume and ribosomal activity as indicated by hybridization studies using fluorescently labeled ribosomal probes. these results indicated that, although immobilized cells were nonculturable, they were metabolically active and thus could be used for biodegradation of toxic compounds.

  7. Efficient biodegradation of chlorophenols in aqueous phase by magnetically immobilized aniline-degrading Rhodococcus rhodochrous strain

    OpenAIRE

    Hou, Jianfeng; Liu, Feixia; Wu, Nan; Ju, Jiansong; Yu, Bo

    2016-01-01

    Background Chlorophenols are environmental contaminants, which are highly toxic to living beings due to their carcinogenic, mutagenic and cytotoxic properties. Bacterial degradation has been considered a cost-effective and eco-friendly method of removing chlorophenols, compared to the traditional physical–chemical processes. Results In this study, we first developed an efficient process for the biodegradation of chlorophenols by magnetically immobilized Rhodococcus rhodochrous cells. R. rhodo...

  8. Comparative Analysis of Immobilization Carriers for a Endopolygalacturonase Producing Yeast Strain

    Czech Academy of Sciences Publication Activity Database

    Almeida, C.; Brányik, Tomáš; Moradas-Ferreira, P.; Teixeira, J.

    Bratislava : Slovak University of Technology, 2003 - (Markoš, J.; Štefuca, V.), s. 155 ISBN 80-227-1889-0. [International Conference of Slovak Society of Chemical Engineering /30./. Tatranské Matliare (SK), 26.05.2003-30.05.2003] Institutional research plan: CEZ:AV0Z4072921 Keywords : continuous reactor * immobilized yeast cells * pectinase Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  9. Detoxification of Corncob Acid Hydrolysate with SAA Pretreatment and Xylitol Production by Immobilized Candida tropicalis

    OpenAIRE

    Li-Hong Deng; Yong Tang; Yun Liu

    2014-01-01

    Xylitol fermentation production from corncob acid hydrolysate has become an attractive and promising process. However, corncob acid hydrolysate cannot be directly used as fermentation substrate owing to various inhibitors. In this work, soaking in aqueous ammonia (SAA) pretreatment was employed to reduce the inhibitors in acid hydrolysate. After detoxification, the corncob acid hydrolysate was fermented by immobilized Candida tropicalis cell to produce xylitol. Results revealed that SAA pretr...

  10. Systematic studies of protein immobilization by surface plasmon field-enhanced fluorescence spectroscopy

    OpenAIRE

    Liu, Jing

    2005-01-01

    The research interest of this study is to investigate surface immobilization strategies for proteins and other biomolecules by the surface plasmon field-enhanced fluorescence spectroscopy (SPFS) technique. The recrystallization features of the S-layer proteins and the possibility of combining the S-layer lattice arrays with other functional molecules make this protein a prime candidate for supramolecular architectures. The recrystallization behavior on gold or on the secondary cell wall po...

  11. An Amperometric Biosensor for Glucose Determination Prepared from Glucose Oxidase Immobilized in Polyaniline-Polyvinylsulfonate Film

    OpenAIRE

    Halit Arslan; Selvin Ustabaş; Fatma Arslan

    2011-01-01

    In this study, a novel amperometric glucose biosensor with immobilization of glucose oxidase on electrochemically polymerized polyaniline-polyvinylsulphonate (Pani-Pvs) films has been accomplished via the entrapment technique. Electropolymerization of aniline on the Pt surface of the Pt electrode was carried out at constant potential (0.75 V, vs. Ag/AgCl) using an electrochemical cell containing aniline and polyvinylsulphonate. Firstly, the optimum working conditions for preparing polyaniline...

  12. Tritium immobilization and packaging using metal hydrides

    International Nuclear Information System (INIS)

    Tritium recovered from CANDU heavy water reactors will have to be packaged and stored in a safe manner. Tritium will be recovered in the elemental form, T2. Metal tritides are effective compounds in which to immobilize the tritium as a stable non-reactive solid with a high tritium capacity. The technology necessary to prepare hydrides of suitable metals, such as titanium and zirconium, have been developed and the properties of the prepared materials evaluated. Conceptual designs of packages for containing metal tritides suitable for transportation and long-term storage have been made and initial testing started. (author)

  13. Consecutive alcoholic fermentations of white grape musts with yeasts immobilized on grape skins : effect of biocatalyst storage and SO2 concentration on wine characteristics

    OpenAIRE

    Genisheva, Zlatina Asenova; Vilanova, Mar; Mussatto, Solange I.; Teixeira, J.A.; Oliveira, J.M.

    2014-01-01

    Abstract Saccharomyces cerevisiae yeasts, immobilized by natural adsorption on grape skins, were used to carry out the alcoholic fermentation step of a winemaking process. The viability of the immobilized cells was evaluated by the implementation of 7 successive fermentations of a white grape must containing 30 mg/L of SO2. The time to complete alcoholic fermentation, the physicochemical characteristics of the produced wines (ethanol, glycerol, organic acids, volatile compounds, color) and se...

  14. Determination of Immobilization Process Parameters of Corynebacterium glutamicum on Kappa carrageenan, Its Application in L-lysine Fermentation and The Investigation Into Its Storage Conditions

    OpenAIRE

    Suong Thi Hong Nguyen

    2014-01-01

    The parameters of the immobilized process of Corynebacterium glutamicum on kappa carrageenan were identified by Plackett-Burman matrix, and the experiments were designed by response surface methodology having the central composite designs (RSM-CCD). The maximum yield of cell immobilization on kappa carrageenan carrier reached at 78% ± 2%. Optimal parameters were 3 grams kappa carrageenan per 100 militters sterile water and 58.58 million cfu/mL, forming gels at 100C for 25 minutes ...

  15. Immobilized Metal Affinity Chromatography Coupled to Multiple Reaction Monitoring Enables Reproducible Quantification of Phospho-signaling.

    Science.gov (United States)

    Kennedy, Jacob J; Yan, Ping; Zhao, Lei; Ivey, Richard G; Voytovich, Uliana J; Moore, Heather D; Lin, Chenwei; Pogosova-Agadjanyan, Era L; Stirewalt, Derek L; Reding, Kerryn W; Whiteaker, Jeffrey R; Paulovich, Amanda G

    2016-02-01

    A major goal in cell signaling research is the quantification of phosphorylation pharmacodynamics following perturbations. Traditional methods of studying cellular phospho-signaling measure one analyte at a time with poor standardization, rendering them inadequate for interrogating network biology and contributing to the irreproducibility of preclinical research. In this study, we test the feasibility of circumventing these issues by coupling immobilized metal affinity chromatography (IMAC)-based enrichment of phosphopeptides with targeted, multiple reaction monitoring (MRM) mass spectrometry to achieve precise, specific, standardized, multiplex quantification of phospho-signaling responses. A multiplex immobilized metal affinity chromatography- multiple reaction monitoring assay targeting phospho-analytes responsive to DNA damage was configured, analytically characterized, and deployed to generate phospho-pharmacodynamic curves from primary and immortalized human cells experiencing genotoxic stress. The multiplexed assays demonstrated linear ranges of ≥3 orders of magnitude, median lower limit of quantification of 0.64 fmol on column, median intra-assay variability of 9.3%, median inter-assay variability of 12.7%, and median total CV of 16.0%. The multiplex immobilized metal affinity chromatography- multiple reaction monitoring assay enabled robust quantification of 107 DNA damage-responsive phosphosites from human cells following DNA damage. The assays have been made publicly available as a resource to the community. The approach is generally applicable, enabling wide interrogation of signaling networks. PMID:26621847

  16. Detoxification of Corncob Acid Hydrolysate with SAA Pretreatment and Xylitol Production by Immobilized Candida tropicalis

    Directory of Open Access Journals (Sweden)

    Li-Hong Deng

    2014-01-01

    Full Text Available Xylitol fermentation production from corncob acid hydrolysate has become an attractive and promising process. However, corncob acid hydrolysate cannot be directly used as fermentation substrate owing to various inhibitors. In this work, soaking in aqueous ammonia (SAA pretreatment was employed to reduce the inhibitors in acid hydrolysate. After detoxification, the corncob acid hydrolysate was fermented by immobilized Candida tropicalis cell to produce xylitol. Results revealed that SAA pretreatment showed high delignification and efficient removal of acetyl group compounds without effect on cellulose and xylan content. Acetic acid was completely removed, and the content of phenolic compounds was reduced by 80%. Furthermore, kinetic behaviors of xylitol production by immobilized C. tropicalis cell were elucidated from corncob acid hydrolysate detoxified with SAA pretreatment and two-step adsorption method, respectively. The immobilized C. tropicalis cell showed higher productivity efficiency using the corncob acid hydrolysate as fermentation substrate after detoxification with SAA pretreatment than by two-step adsorption method in the five successive batch fermentation rounds. After the fifth round fermentation, about 60 g xylitol/L fermentation substrate was obtained for SAA pretreatment detoxification, while about 30 g xylitol/L fermentation substrate was obtained for two-step adsorption detoxification.

  17. Detoxification of Corncob Acid Hydrolysate with SAA Pretreatment and Xylitol Production by Immobilized Candida tropicalis

    Science.gov (United States)

    Deng, Li-Hong; Tang, Yong; Liu, Yun

    2014-01-01

    Xylitol fermentation production from corncob acid hydrolysate has become an attractive and promising process. However, corncob acid hydrolysate cannot be directly used as fermentation substrate owing to various inhibitors. In this work, soaking in aqueous ammonia (SAA) pretreatment was employed to reduce the inhibitors in acid hydrolysate. After detoxification, the corncob acid hydrolysate was fermented by immobilized Candida tropicalis cell to produce xylitol. Results revealed that SAA pretreatment showed high delignification and efficient removal of acetyl group compounds without effect on cellulose and xylan content. Acetic acid was completely removed, and the content of phenolic compounds was reduced by 80%. Furthermore, kinetic behaviors of xylitol production by immobilized C. tropicalis cell were elucidated from corncob acid hydrolysate detoxified with SAA pretreatment and two-step adsorption method, respectively. The immobilized C. tropicalis cell showed higher productivity efficiency using the corncob acid hydrolysate as fermentation substrate after detoxification with SAA pretreatment than by two-step adsorption method in the five successive batch fermentation rounds. After the fifth round fermentation, about 60 g xylitol/L fermentation substrate was obtained for SAA pretreatment detoxification, while about 30 g xylitol/L fermentation substrate was obtained for two-step adsorption detoxification. PMID:25133211

  18. A comparison of redox polymer and enzyme co-immobilization on carbon electrodes to provide membrane-less glucose/O2 enzymatic fuel cells with improved power output and stability.

    Science.gov (United States)

    Rengaraj, Saravanan; Kavanagh, Paul; Leech, Dónal

    2011-12-15

    Glassy carbon and graphite electrodes modified with films of enzyme and osmium redox polymer, cross linked with poly (ethylene glycol) diglycidyl ether, were used for elaboration of a glucose/O(2) enzymatic fuel cell. The redox polymers [Os(4,4'-dimethoxy-2,2'-bipyridine)(2)(polyvinylimidazole)(10)Cl](+) and [Os(4,4'-dichloro-2,2'-bipyridine)(2)(polyvinylimidazole)(10)Cl](+) were selected to facilitate transfer of electrons from the glucose oxidase (GOx) active site to the T1 Cu site of multicopper oxygenases of Trametes hirsuta laccase (ThLacc) and Myrothecium verrucaria bilirubin oxidase (MvBOD). Maximum power density at pH 5.5 of 3.5 μW cm(-2) at a cell voltage of 0.35 V was obtained for an assembled membrane-less fuel cell based on ThLacc on glassy carbon as cathode, in the presence of 0.1 M glucose, 37 °C, with lower power observed at pH 7.4 and 4.5. Replacement of the ThLacc cathode with that of MvBOD produced 10 μW cm(-2) at 0.25 V under pseudo-physiological conditions. Replacement of glassy carbon with graphite as base electrode material resulted in increased redox polymer loading, leading to an increase in power output to 43 μW cm(-2) at 0.25 V under similar conditions. Improved stabilization of biofilms was achieved through covalent anchoring of enzyme and redox polymer on graphite electrodes, derivatized via electrochemical reduction of the diazonium cation generated in situ from p-phenylenediamine. Enzymatic fuel cells using this approach retained 70% power at 24 h, whereas fuel cells prepared without chemical anchoring to graphite retained only 10% of power over the same interval. PMID:22005596

  19. In vivo biotinylation of recombinant beta-glucosidase enables simultaneous purification and immobilization on streptavidin coated magnetic particles

    DEFF Research Database (Denmark)

    Alftrén, Johan; Ottow, Kim Ekelund; Hobley, Timothy John

    2013-01-01

    Beta-glucosidase from Bacillus licheniformis was in vivo biotinylated in Escherichia coli and subsequently immobilized directly from cell lysate on streptavidin coated magnetic particles. In vivo biotinylation was mediated by fusing the Biotin Acceptor Peptide to the C-terminal of beta-glucosidas...

  20. Plutonium immobilization in glass and ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Knecht, D.A. [Lockheed Martin Idaho Technologies, Idaho Falls (United States); Murphy, W.M. [Southwest Research Institute, San Antonio, TX (United States)

    1996-05-01

    The Materials Research Society Nineteenth Annual Symposium on the Scientific Basis for Nuclear Waste Management was held in Boston on November 27 to December 1, 1995. Over 150 papers were presented at the Symposium dealing with all aspects of nuclear waste management and disposal. Fourteen oral sessions and on poster session included a Plenary session on surplus plutonium dispositioning and waste forms. The proceedings, to be published in April, 1996, will provide a highly respected, referred compilation of the state of scientific development in the field of nuclear waste management. This paper provides a brief overview of the selected Symposium papers that are applicable to plutonium immobilization and plutonium waste form performance. Waste forms that were described at the Symposium cover most of the candidate Pu immobilization options under consideration, including borosilicate glass with a melting temperature of 1150 {degrees}C, a higher temperature (1450 {degrees}C) lanthanide glass, single phase ceramics, multi-phase ceramics, and multi-phase crystal-glass composites (glass-ceramics or slags). These Symposium papers selected for this overview provide the current status of the technology in these areas and give references to the relevant literature.