Constitutive synthesis of a transport function encoded by the Thiobacillus ferrooxidans merC gene cloned in Escherichia coli

International Nuclear Information System (INIS)

Kusano, Tomonobu; Ji, Guangyong; Silver, S.; Inoue, Chihiro

1990-01-01

Mercuric reductase activity determined by the Thiobacillus ferrooxidans merA gene (cloned and expressed constitutively in Escherichia coli) was measured by volatilization of 203 Hg 2+ . (The absence of a merR regulatory gene in the cloned Thiobacillus mer determinant provides a basis for the constitutive synthesis of this system.) In the absence of the Thiobacillus merC transport gene, the mercury volatilization activity was cryptic and was not seen with whole cells but only with sonication-disrupted cells. The Thiobacillus merC transport function was compared with transport via the merT-merP system of plasmid pDU1358. Both systems, cloned and expressed in E. coli, governed enhanced uptake of 203 Hg 2+ in a temperature- and concentration-dependent fashion. Uptake via MerT-MerP was greater and conferred greater hypersensitivity to Hg 2+ than did uptake with MerC. Mercury uptake was inhibited by N-ethylmaleimide but not by EDTA. Ag + salts inhibited mercury uptake by the MerT-MerP system but did not inhibit uptake via MerC. Radioactive mercury accumulated by the MerT-MerP and by the MerC systems was exchangeable with nonradioactive Hg 2+

Co-Cultures of Pseudomonas aeruginosa and Roseobacter denitrificans Reveal Shifts in Gene Expression Levels Compared to Solo Cultures

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Crystal A. Conway

2012-01-01

Full Text Available Consistent biosynthesis of desired secondary metabolites (SMs from pure microbial cultures is often unreliable. In a proof-of-principle study to induce SM gene expression and production, we describe mixed “co-culturing” conditions and monitoring of messages via quantitative real-time PCR (qPCR. Gene expression of model bacterial strains (Pseudomonas aeruginosa PAO1 and Roseobacter denitrificans Och114 was analyzed in pure solo and mixed cocultures to infer the effects of interspecies interactions on gene expression in vitro, Two P. aeruginosa genes (PhzH coding for portions of the phenazine antibiotic pathway leading to pyocyanin (PCN and the RhdA gene for thiosulfate: cyanide sulfurtransferase (Rhodanese and two R. denitrificans genes (BetaLact for metallo-beta-lactamase and the DMSP gene for dimethylpropiothetin dethiomethylase were assessed for differential expression. Results showed that R. denitrificans DMSP and BetaLact gene expression became elevated in a mixed culture. In contrast, P. aeruginosa co-cultures with R. denitrificans or a third species did not increase target gene expression above control levels. This paper provides insight for better control of target SM gene expression in vitro and bypass complex genetic engineering manipulations.

Novel Castellaniella denitrificans SA13P as a Potent Malachite Green Decolorizing Strain

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Ankita Chawla

2014-01-01

Full Text Available Triphenylmethane dyes represent a major group of dyes causing serious environmental hazards. Malachite Green is one of the commonly and extensively used triphenylmethane dyes although it is carcinogenic and mutagenic in nature. Various physicochemical methods have been employed for its elimination but are highly expensive, coupled with the formation of huge amount of sludge. Hence, biological methods being ecofriendly are good alternatives. In the present study, the novel bacterial isolate SA13P was isolated from UASB tank of tannery effluent treatment plant. Phylogenetic characterization of 1470 bp fragment of SA13P has revealed its similarity with Castellaniella denitrificans. This strain has been found to decolorize the dye (malachite green at a concentration of 100 mg L−1 (80.29%. Decolorization was done by living bacterial cells rather than adsorption. Growth conditions have also been optimized for the decolorization. Maximum decolorization was observed at a temperature of 37°C and pH 8.0. Also, it has been found that bacterization of seeds of Vigna radiata with Castellaniella denitrificans SA13P increases germination rate. We have reported for the first time that Castellaniella denitrificans SA13P may be used as a novel strain for dye decolorization (malachite green and biological treatment of tannery effluent.

Electrochemistry suggests proton access from the exit site to the binuclear center in Paracoccus denitrificans cytochrome c oxidase pathway variants.

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Meyer, Thomas; Melin, Frédéric; Richter, Oliver-M H; Ludwig, Bernd; Kannt, Aimo; Müller, Hanne; Michel, Hartmut; Hellwig, Petra

2015-02-27

Two different pathways through which protons access cytochrome c oxidase operate during oxygen reduction from the mitochondrial matrix, or the bacterial cytoplasm. Here, we use electrocatalytic current measurements to follow oxygen reduction coupled to proton uptake in cytochrome c oxidase isolated from Paracoccus denitrificans. Wild type enzyme and site-specific variants with defects in both proton uptake pathways (K354M, D124N and K354M/D124N) were immobilized on gold nanoparticles, and oxygen reduction was probed electrochemically in the presence of varying concentrations of Zn(2+) ions, which are known to inhibit both the entry and the exit proton pathways in the enzyme. Our data suggest that under these conditions substrate protons gain access to the oxygen reduction site via the exit pathway. Copyright © 2015 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

Two component system that regulates methanol and formaldehyde oxidation in Paracoccus denitrificans.

NARCIS (Netherlands)

Harms, N.; Reijnders, W.N.M.; Koning, S.; van Spanning, R.J.M.

2001-01-01

A chromosomal region encoding a two-component regulatory system, FlhRS, has been isolated from Paracoccus denitrificans. FlhRS-deficient mutants were unable to grow on methanol, methylamine, or choline as the carbon and energy source. Expression of the gene encoding glutathione-dependent

Two-component system that regulates methanol and formaldehyde oxidation in Paracoccus denitrificans.

NARCIS (Netherlands)

Harms, N.; Reijnders, W.N.M.; Koning, S.; van Spanning, R.J.M.

2001-01-01

A chromosomal region encoding a two-component regulatory system, FlhRS, has been isolated from Paracoccus denitrificans. FlhRS-deficient mutants were unable to grow on methanol, methylamine, or choline as the carbon and energy source. Expression of the gene encoding glutathione-dependent

Industrial vitamin B12 production by Pseudomonas denitrificans using maltose syrup and corn steep liquor as the cost-effective fermentation substrates.

Science.gov (United States)

Xia, Wei; Chen, Wei; Peng, Wei-Fu; Li, Kun-Tai

2015-06-01

The aerobic Pseudomonas denitrificans is widely used for industrial and commercial vitamin B12 fermentation, due to its higher productivity compared to the anaerobic vitamin B12-producing microorganisms. This paper aimed to develop a cost-effective fermentation medium for industrial vitamin B12 production by P. denitrificans in 120,000-l fermenter. It was found that maltose syrup (a low-cost syrup from corn starch by means of enzymatic or acid hydrolysis) and corn steep liquor (CSL, a by-product of starch industry) were greatly applicable to vitamin B12 production by P. denitrificans. Under the optimal fermentation medium performed by response surface methodology, 198.27 ± 4.60 mg/l of vitamin B12 yield was obtained in 120,000-l fermenter, which was close to the fermentation with the refined sucrose (198.80 mg/l) and was obviously higher than that obtained under beet molasses utilization (181.75 mg/l). Therefore, maltose syrups and CSL were the efficient and economical substrates for industrial vitamin B12 fermentation by P. denitrificans.

Study of a bacterial leaching program for uranium ores by Thiobacillus ferroxidans

International Nuclear Information System (INIS)

Garcia Junior, O.

1989-01-01

The development of a bacterial leaching program for uranium ores is studied. Three basic points are presented: isolation and purification of Thiobacillus ferroxidans, as well Thiobacillus thio oxidans; physiological studies of growth and respiratory metabolism of T. ferroxidans; uranium leaching from two types of ore by T. ferroxidans action, on laboratory, semi pilot and pilot scales. The bacterial leaching studies were carried out in shake flasks, percolation columns (laboratory and semi pilot) and in heap leaching (pilot). The potential of the ores studied in relation to bacterial action, was first showed in shake flask experiments. The production of H 2 S O 4 and Fe 3+ was a result of the bacterial activity on both ore samples containing pyrite (Fe S 2 ). These two bacterial products resulted in a high uranium and molybdenum extraction and a lower sulfuric acid consumption compared to the sterilized treatments. Similar results were obtained in percolation column at the same scale (lab). (author)

The Effect of Inoculants of Thiobacillus and Aspergillus on Corn Growth

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M. Mohammdi Aria

2011-01-01

Full Text Available Abstract Phosphorus (P is one of the essential macronutrients for growth and development of plant. Phosphorus is added to soil in the form of phosphatic fertilizers, part of which is utilized by plants and the remainder converted into insoluble fixed forms. Increasingly high cost of chemical fertilizers has been the major stimulus to search for an alternative, naturally-occurring, phosphate source. The researchers offered phosphorus rocks as a valuable alternative source for P. fertilizer. Unfortunately, rock phosphate is not plant available in soils with a pH greater than 6. One method to increase soluble form inorganic P is application of phosphate solublizing microorganisms and sulfur oxidizing bacteria (Thiobacillus with rock phosphate. A greenhouse experiment was carried out with two bio fertilizers (bio fertilizers santes in incubation condition in a soil with low available P on corn growth. The bio fertilizers were: rock phosphate with 20% sulfur, 15% vermicompost, Thiobacillus bacteria and Aspergillus fungi (BFS20V15 at three rates: 440 kg/ha (BF1 , 880 kg/ha (BF2, 1320kg/ha (BF3, rock phosphate with 20% sulfur, 15% vermicompost, Thiobacillus bacteria (BFS20V15 at three rates: 440 kg/ha (B1 , 880 kg/ha (B2, 1320kg/ha (B3, triple super phosphate (TSP, and control without phosphorus. In the greenhouse experiment, shoot dry matter, p uptake in plant and available p in soil were determined. The results showed that maximum yield obtained from BF3 with the shoot dry weight 7.2 g per plant and with no significant difference in relation to the triple super phosphate (7.5g at 5% level. Also highest rate p-uptake resulted from BF3. There was significant difference between treatment BF3 and TSP on p-uptake. Results indicated that it could be possible to substitute rock phosphate inoculated with sulfur-oxidizing bacteria and phosphorous-solublizing fungus for super phosphate. Keywords: Uptake-p, pH Rock phosphate, Solfur, Vermicompost

Purification, characterization and crystallization of the F-ATPase from Paracoccus denitrificans.

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Morales-Rios, Edgar; Watt, Ian N; Zhang, Qifeng; Ding, Shujing; Fearnley, Ian M; Montgomery, Martin G; Wakelam, Michael J O; Walker, John E

2015-09-01

The structures of F-ATPases have been determined predominantly with mitochondrial enzymes, but hitherto no F-ATPase has been crystallized intact. A high-resolution model of the bovine enzyme built up from separate sub-structures determined by X-ray crystallography contains about 85% of the entire complex, but it lacks a crucial region that provides a transmembrane proton pathway involved in the generation of the rotary mechanism that drives the synthesis of ATP. Here the isolation, characterization and crystallization of an integral F-ATPase complex from the α-proteobacterium Paracoccus denitrificans are described. Unlike many eubacterial F-ATPases, which can both synthesize and hydrolyse ATP, the P. denitrificans enzyme can only carry out the synthetic reaction. The mechanism of inhibition of its ATP hydrolytic activity involves a ζ inhibitor protein, which binds to the catalytic F₁-domain of the enzyme. The complex that has been crystallized, and the crystals themselves, contain the nine core proteins of the complete F-ATPase complex plus the ζ inhibitor protein. The formation of crystals depends upon the presence of bound bacterial cardiolipin and phospholipid molecules; when they were removed, the complex failed to crystallize. The experiments open the way to an atomic structure of an F-ATPase complex. © 2015 The Authors.

Ultrafast excited state processes in Roseobacter denitrificans antennae: comparison of isolated complexes and native membranes

NARCIS (Netherlands)

Ferretti, M.; Duquesne, K.; Sturgis, J.N.; van Grondelle, R.

2014-01-01

Roseobacter (Rsb.) denitrificans is a marine aerobic anoxygenic photosynthetic purple bacterium with an unusually high-800 nm absorption band. Ultrafast excited state processes have been intensively studied in the past in order to understand why the energy transfer efficiency between photosynthetic

Proteomic analysis of nitrate-dependent acetone degradation by Alicycliphilus denitrificans strain BC.

Science.gov (United States)

Oosterkamp, Margreet J; Boeren, Sjef; Atashgahi, Siavash; Plugge, Caroline M; Schaap, Peter J; Stams, Alfons J M

2015-06-01

Alicycliphilus denitrificans strain BC grows anaerobically on acetone with nitrate as electron acceptor. Comparative proteomics of cultures of A. denitrificans strain BC grown on either acetone or acetate with nitrate was performed to study the enzymes involved in the acetone degradation pathway. In the proposed acetone degradation pathway, an acetone carboxylase converts acetone to acetoacetate, an AMP-dependent synthetase/ligase converts acetoacetate to acetoacetyl-CoA, and an acetyl-CoA acetyltransferase cleaves acetoacetyl-CoA to two acetyl-CoA. We also found a putative aldehyde dehydrogenase associated with acetone degradation. This enzyme functioned as a β-hydroxybutyrate dehydrogenase catalyzing the conversion of surplus acetoacetate to β-hydroxybutyrate that may be converted to the energy and carbon storage compound, poly-β-hydroxybutyrate. Accordingly, we confirmed the formation of poly-β-hydroxybutyrate in acetone-grown cells of strain BC. Our findings provide insight in nitrate-dependent acetone degradation that is activated by carboxylation of acetone. This will aid studies of similar pathways found in other microorganisms degrading acetone with nitrate or sulfate as electron acceptor. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Co-Inoculation Effects of Thiobacillus thiooxidans Bacteria and Mycorrhiza (Glomus spp. on Maize Nutrition at Different Levels of Sulfur

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A. Gholami

2016-02-01

Full Text Available Introduction: Sulfur is the key element for higher crops and plays an important role in the formation of proteins, vitamins, and enzymes. It is a constituent of amino acids such as cysteine and methionine, which act for the synthesis of other compounds containing reduced sulfur, such as chlorophyll and utilization of phosphorus and otheressential nutrients.Deficiency of this nutrient in soil is usually compensated by using chemical fertilizers. However, these fertilizers have harmful effects on the environment and decrease the quality of the agriculture products. Therefore, biological fertilizers are more useful for using in agricultural ecosystems.Sulfurshould be addedto the soil, usually in a reduced form such as elemental sulfur. Use of S oxidizers enhances the rate of natural oxidation of S and speeds up the production of sulfates and makes them available to plants consequently resulting in an increased plant yield. The role of chemolithotrophic bacteria of the genus Thiobacillus through oxidation process in the soil is usually emphasized. Sulfur oxidation is the most important step of sulfur cycle, which improves soil fertility. The result is formation of sulfate, which can be used by the plants, while the acidity produced by oxidation helps to solubilize nutrients in alkaline soils. These bacteria can solubilise the soil minerals through the production of H2SO4 that reacts with these non-soluble minerals and oxidised them to be available nutrients to the cultivated plants. Arbuscular MycorrhizalFungi isan important component ofthe microbiota, mutualistic symbioticsoilfungithatcolonizesthe rootsofmost cropplants.The AM symbiosis involves an about 80% of land plant species and 92% of plant families. They have theability to enhance host uptake of relativelyimmobile nutrientsparticularly phosphorus (P andzinc (Zn,Manganese (Mn andiron(Fe.Arbuscular mycorrhizal fungi increased plant uptake of phosphorus, nitrogen and water absorption

Phospholipid Fatty Acids as Physiological Indicators of Paracoccus denitrificans Encapsulated in Silica Sol-Gel Hydrogels

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Josef Trögl

2015-02-01

Full Text Available The phospholipid fatty acid (PLFA content was determined in samples of Paracoccus denitrificans encapsulated in silica hydrogel films prepared from prepolymerized tetramethoxysilane (TMOS. Immediately after encapsulation the total PLFA concentration was linearly proportional to the optical density (600 nm of the input microbial suspension (R2 = 0.99. After 7 days this relationship remained linear, but with significantly decreased slope, indicating a higher extinction of bacteria in suspensions of input concentration 108 cells/mL and higher. trans-Fatty acids, indicators of cytoplasmatic membrane disturbances, were below the detection limit. The cy/pre ratio (i.e., ratio of cyclopropylated fatty acids (cy17:0 + cy19:0 to their metabolic precursors (16:1ω7 + 18:1ω7, an indicator of the transition of the culture to a stationary growth-phase, decreased depending on co-immobilization of nutrients in the order phosphate buffer > mineral medium > Luria Broth rich medium. The ratio, too, was logarithmically proportional to cell concentration. These results confirm the applicability of total PLFA as an indicator for the determination of living biomass and cy/pre ratio for determination of nutrient limitation of microorganisms encapsulated in sol-gel matrices. This may be of interest for monitoring of sol-gel encapsulated bacteria proposed as optical recognition elements in biosensor construction, as well as other biotechnological applications.

Specific dot-immunobinding assay for detection and enumeration of Thiobacillus ferrooxidans

International Nuclear Information System (INIS)

Arredondo, R.; Jerez, C.A.

1989-01-01

A specific and very sensitive dot-immunobinding assay for the detection and enumeration of the bioleaching microorganism Thiobacillus ferrooxidans was developed. Nitrocellulose spotted with samples was incubated with polyclonal antisera against whole T. ferrooxidans cells and then in 125 I-labeled protein A or 125 I-labeled goat antirabbit immunoglobulin G; incubation was followed by autoradiography. Since a minimum of 10 3 cells per dot could be detected, the method offers the possibility of simultaneous processing of numerous samples in a short time to monitor the levels of T. ferrooxidans in bioleaching operations

Achromobactor denitrificans SP1 produces pharmaceutically active 25C prodigiosin upon utilizing hazardous di(2-ethylhexyl)phthalate

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Achromobacter denitrificans SP1 isolated from soil sludge heavily contaminated with plastic waste produced a novel pharmaceutically-active 25C prodigiosin analog during growth in a simple mineral salt medium supplemented with hazardous di(2-ethylhexyl)phthalate (DEHP) blended PVC plastics (in situ) ...

Evaluation of Thiobacillus Bacteria and Mycorrhizal Symbiosis on Yield and Yield Components of Garlic (Allium sativum at Different Levels of Sulfur

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parvin Hejazi rad

2017-09-01

Full Text Available Introduction Most researchers believe that good management and proper use of biofertilizers are the ways for preparation of better nutritional conditions for the medicinal plant. Garlic is one of the most important medicinal crops. Allicin is the main active ingredient in this plant. Biofertilizers contain beneficial soil microorganisms or the metabolic products. Mycorrhizal symbiosis improves the soil physical, chemical and biological properties. Mycorrhizae increase crop resistance to pathogens, nutrient and water uptake, also reduce the negative effects of environmental stress and improve the quality of their host plants. Adding sulfur to the soil to improve the nutritional status of the plant by the release of nutrients will be effective when that the oxidation of sulfur in the soil is significant. For sulfur uptake by the plant, it is necessary that this element convert to sulfate by soil microorganisms. If elemental sulfur distribute in the soil and mix with the organic material, conversion of sulfur-oxidizing microorganisms be faster in wet conditions. Materials and methods The experiment was conducted as randomized complete block design with three replications in 2012. Treatments were included control plot, mycorrhizal inoculation (M, Thiobacillus (T, M + T, 75 kg sulfur per hectare (75S, 75S + M, 75S + T, 75S + M + T, 150 kg sulfur per hectare (150S, 150S + M, 150S + T, 150S + M + T. Each plot consisted of four rows with a spacing of 40 cm and row length of 10 m. In treatments with 75 and 150 kg sulfur per hectare, 48 and 96 g of sulfur were used, respectively. Thiobacillus at the recommended dose was added to the soil a week before planting. Percent of fungal colonization obtained with Gridline Intersect Method. HPLC method was used to extract allicin content. Data were analyzed with the MSTAT-C software; the means were compared with LSD test at the 5% level of probability. Results and discussion The results showed that tuber dry

Structure of a catalytic dimer of the α- and β-subunits of the F-ATPase from Paracoccus denitrificans at 2.3 Å resolution

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Morales-Ríos, Edgar; Montgomery, Martin G. [The Medical Research Council Mitochondrial Biology Unit, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY (United Kingdom); Leslie, Andrew G. W. [The Medical Research Council Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge CB2 0QH (United Kingdom); García-Trejo, José J. [Universidad Nacional Autónoma de México, Mexico City (Mexico); Walker, John E., E-mail: walker@mrc-mbu.cam.ac.uk [The Medical Research Council Mitochondrial Biology Unit, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY (United Kingdom)

2015-09-23

The structure of the αβ heterodimer of the F-ATPase from the α-proteobacterium P. denitrificans has been determined at 2.3 Å resolution. It corresponds to the ‘open’ or ‘empty’ catalytic interface found in other F-ATPases. The structures of F-ATPases have predominantly been determined from mitochondrial enzymes, and those of the enzymes in eubacteria have been less studied. Paracoccus denitrificans is a member of the α-proteobacteria and is related to the extinct protomitochondrion that became engulfed by the ancestor of eukaryotic cells. The P. denitrificans F-ATPase is an example of a eubacterial F-ATPase that can carry out ATP synthesis only, whereas many others can catalyse both the synthesis and the hydrolysis of ATP. Inhibition of the ATP hydrolytic activity of the P. denitrificans F-ATPase involves the ζ inhibitor protein, an α-helical protein that binds to the catalytic F{sub 1} domain of the enzyme. This domain is a complex of three α-subunits and three β-subunits, and one copy of each of the γ-, δ- and ∊-subunits. Attempts to crystallize the F{sub 1}–ζ inhibitor complex yielded crystals of a subcomplex of the catalytic domain containing the α- and β-subunits only. Its structure was determined to 2.3 Å resolution and consists of a heterodimer of one α-subunit and one β-subunit. It has no bound nucleotides, and it corresponds to the ‘open’ or ‘empty’ catalytic interface found in other F-ATPases. The main significance of this structure is that it aids in the determination of the structure of the intact membrane-bound F-ATPase, which has been crystallized.

Structure of a catalytic dimer of the α- and β-subunits of the F-ATPase from Paracoccus denitrificans at 2.3 Å resolution

International Nuclear Information System (INIS)

Morales-Ríos, Edgar; Montgomery, Martin G.; Leslie, Andrew G. W.; García-Trejo, José J.; Walker, John E.

2015-01-01

The structure of the αβ heterodimer of the F-ATPase from the α-proteobacterium P. denitrificans has been determined at 2.3 Å resolution. It corresponds to the ‘open’ or ‘empty’ catalytic interface found in other F-ATPases. The structures of F-ATPases have predominantly been determined from mitochondrial enzymes, and those of the enzymes in eubacteria have been less studied. Paracoccus denitrificans is a member of the α-proteobacteria and is related to the extinct protomitochondrion that became engulfed by the ancestor of eukaryotic cells. The P. denitrificans F-ATPase is an example of a eubacterial F-ATPase that can carry out ATP synthesis only, whereas many others can catalyse both the synthesis and the hydrolysis of ATP. Inhibition of the ATP hydrolytic activity of the P. denitrificans F-ATPase involves the ζ inhibitor protein, an α-helical protein that binds to the catalytic F 1 domain of the enzyme. This domain is a complex of three α-subunits and three β-subunits, and one copy of each of the γ-, δ- and ∊-subunits. Attempts to crystallize the F 1 –ζ inhibitor complex yielded crystals of a subcomplex of the catalytic domain containing the α- and β-subunits only. Its structure was determined to 2.3 Å resolution and consists of a heterodimer of one α-subunit and one β-subunit. It has no bound nucleotides, and it corresponds to the ‘open’ or ‘empty’ catalytic interface found in other F-ATPases. The main significance of this structure is that it aids in the determination of the structure of the intact membrane-bound F-ATPase, which has been crystallized

Ferrous Iron Oxidation by Thiobacillus ferrooxidans: Inhibition with Benzoic Acid, Sorbic Acid, and Sodium Lauryl Sulfate

OpenAIRE

Onysko, Steven J.; Kleinmann, Robert L. P.; Erickson, Patricia M.

1984-01-01

Benzoic acid, sorbic acid, and sodium lauryl sulfate at low concentrations (5 to 10 mg/liter) each effectively inhibited bacterial oxidation of ferrous iron in batch cultures of Thiobacillus ferrooxidans. The rate of chemical oxidation of ferrous iron in low-pH, sterile batch reactors was not substantially affected at the tested concentrations (5 to 50 mg/liter) of any of the compounds.

Ferrous Iron Oxidation by Thiobacillus ferrooxidans: Inhibition with Benzoic Acid, Sorbic Acid, and Sodium Lauryl Sulfate

Science.gov (United States)

Onysko, Steven J.; Kleinmann, Robert L. P.; Erickson, Patricia M.

1984-01-01

Benzoic acid, sorbic acid, and sodium lauryl sulfate at low concentrations (5 to 10 mg/liter) each effectively inhibited bacterial oxidation of ferrous iron in batch cultures of Thiobacillus ferrooxidans. The rate of chemical oxidation of ferrous iron in low-pH, sterile batch reactors was not substantially affected at the tested concentrations (5 to 50 mg/liter) of any of the compounds. PMID:16346592

Structure of nitrogen-converting communities induced by hydraulic retention time and COD/N ratio in constantly aerated granular sludge reactors treating digester supernatant.

Science.gov (United States)

Cydzik-Kwiatkowska, Agnieszka; Rusanowska, Paulina; Zielińska, Magdalena; Bernat, Katarzyna; Wojnowska-Baryła, Irena

2014-02-01

This study investigated how hydraulic retention time (HRT) and COD/N ratio affect nitrogen-converting consortia in constantly aerated granules treating high-ammonium digester supernatant. Three HRTs (10, 13, 19 h) were tested at COD/N ratios of 4.5 and 2.3. Denaturing gradient gel electrophoresis and relative real-time PCR were used to characterize the microbial communities. When changes in HRT and COD/N increased nitrogen loading, the ratio of the relative abundance of aerobic to anaerobic ammonium-oxidizers decreased. The COD/N ratio determined the species composition of the denitrifiers; however, Thiobacillus denitrificans, Pseudomonas denitrificans and Azoarcus sp. showed a high tolerance to the environmental conditions and occurred in the granules from all reactors. Denitrifier genera that support granule formation were identified, such as Pseudomonas, Shinella, and Flavobacterium. In aerated granules, nirK-possessing bacteria were more diverse than nirS-possessing bacteria. At a low COD/N ratio, N2O-reducer diversity increased because of the presence of bacteria known as aerobic denitrifiers. Copyright © 2013 Elsevier Ltd. All rights reserved.

Structure and function of the tetraheme cytochrome associated to the reaction center of Roseobacter denitrificans.

Science.gov (United States)

Garcia, D; Richaud, P; Breton, J; Verméglio, A

1994-01-01

We have characterized the tetrahemic RC bound cytochrome isolated from the quasi-photosynthetic bacterium Roseobacter denitrificans in terms of absorption spectrum, redox property and orientation with respect to the membrane plane. The heme, designated H1, which possesses the highest redox midpoint potential (+290 mV), absorbs at 555 nm. Its plane makes an angle of 40 degrees with the membrane plane. The second high potential heme, H2 (+240 mV), peaks at 554 nm and makes a tilt of 55 degrees with the membrane. The two low potential hemes, L1 and L2, present a similar and rather high redox midpoint potential (+90 mV). They absorb at 553 nm and 550 nm. One of these hemes is oriented at 40 degrees while the other makes an angle of 90 degrees with the membrane plane. The soluble cytochrome c551 completes the cyclic electron transfer between the RC and the bc1 complex. Both the oxidation and the re-reduction of cytochrome c551 are diffusible processes. Under semi-aerobic conditions, one of the low potential hemes is photo-oxidized under illumination but only extremely slowly re-reduced. This explains the requirement of high aerobic conditions for growth of Roseobacter denitrificans cells in the light.

Effects of ionic strength on the coordination of Eu(III) and Cm(III) to a Gram-negative bacterium, Paracoccus denitrificans

International Nuclear Information System (INIS)

Ozaki, T.; Ohnuki, T.; Kimura, T.; Francis, A.J.

2006-01-01

We studied the effect of ionic strength on the interactions of Europium(III) and Curium(III) with a Gram-negative bacterium Paracoccus denitrificans. Bacterial cells grown in 0.5-, 3.5-, and 5.0% NaCl were used in adsorption experiments and laser experiments that were performed at the same ionic strengths as those in the original growth media. The distribution ratio (log K d ) for Eu(III) and Cm(III) was determined at pHs 3-5. To elucidate the coordination environment of Eu(III) adsorbed on P. denitrificans, we estimated the number of water molecules in the inner sphere and strength of the ligand field by time-resolved laser-induced fluorescence spectroscopy (TRLFS) at pHs 4-6. The log K d of Eu(III) and Cm(III) increased with an increase of pH at all ionic strengths because there was less competition for ligands in cells with H + at higher pHs, wherein less H + was present in solution: cation adsorption generally occurs through an exchange with H + on the functional groups of coordination sites. No significant differences were observed in the log K d of Eu(III) and Cm(III) at each pH in 0.5-, 3.5-, and 5.0% NaCl solutions, though competition for ligands with Na + would be expected to increase at higher NaCl concentrations. The log K d of Eu(III) was almost equivalent to that of Cm(III) under all the experimental conditions. TRLFS showed that the coordination environments of Eu(III) did not differ from each other at 0.5-, 3.5-, and 5.0% NaCl at pHs 4-6. TRLFS also showed that the characteristic of the coordination environment of Eu(III) on P. denitrificans was similar to that on a halophile, Nesterenkonia halobia, while it significantly differed from that on a non-halophile, Pseudomonas putida. These findings indicate that the number of coordination sites for Eu(III) on P. denitrificans, whose cell surface may have similar structures to that of halophiles, increased with increasing ionic strength, though their structure remained unchanged. (orig.)

Work within the coordinated programme on bacterial leaching of uranium ores. Immunological identification of Thiobacillus ferrooxidans and Thiobacillus thiooxidans

International Nuclear Information System (INIS)

Rhee, K.S.

1978-04-01

Little is known of the antigenic structure of Thiobacillus. In the composition of the antigens of gram negative bacteria the polysaccharide moiety endows some specificity permitting immunological identification. The report considers work on attempts to isolate the type specific component from T. thiooxidans and T ferrooxidans. The fractionation procedures presented suggest that the presence of one or a few such type specific major protein antigen fractions from both of the T. ferrooxidans and the T. thiooxidans seems to be originated from the cytoplasm of the bacteria, since it is believed that the glycoprotein fractions which was derived from the cell wall are the common antigenic fraction between the T. ferrooxidans and the T. thiooxidans, respectively. In this regard, it is of great interest that the T. ferrooxidans or the T. thiooxidans appears not to have the type-specific antigens on their LPS or polysaccharide moiety in contrast to the other gram-negative bacteria. Thus, it is strongly believed that the envelopes of these bacteria contain both glycoproteins bearing common antigenicity, since the T. ferrooxidans and the T. thiooxidans have a structually different type-specific antigen moiety according to the results polyacrylamide gel electrophoresis

Paracoccus denitrificans possesses two BioR homologs having a role in regulation of biotin metabolism.

Science.gov (United States)

Feng, Youjun; Kumar, Ritesh; Ravcheev, Dmitry A; Zhang, Huimin

2015-08-01

Recently, we determined that BioR, the GntR family of transcription factor, acts as a repressor for biotin metabolism exclusively distributed in certain species of α-proteobacteria, including the zoonotic agent Brucella melitensis and the plant pathogen Agrobacterium tumefaciens. However, the scenario is unusual in Paracoccus denitrificans, another closely related member of the same phylum α-proteobacteria featuring with denitrification. Not only does it encode two BioR homologs Pden_1431 and Pden_2922 (designated as BioR1 and BioR2, respectively), but also has six predictive BioR-recognizable sites (the two bioR homolog each has one site, whereas the two bio operons (bioBFDAGC and bioYB) each contains two tandem BioR boxes). It raised the possibility that unexpected complexity is present in BioR-mediated biotin regulation. Here we report that this is the case. The identity of the purified BioR proteins (BioR1 and BioR2) was confirmed with LC-QToF-MS. Phylogenetic analyses combined with GC percentage raised a possibility that the bioR2 gene might be acquired by horizontal gene transfer. Gel shift assays revealed that the predicted BioR-binding sites are functional for the two BioR homologs, in much similarity to the scenario seen with the BioR site of A. tumefaciens bioBFDAZ. Using the A. tumefaciens reporter system carrying a plasmid-borne LacZ fusion, we revealed that the two homologs of P. denitrificans BioR are functional repressors for biotin metabolism. As anticipated, not only does the addition of exogenous biotin stimulate efficiently the expression of bioYB operon encoding biotin transport/uptake system BioY, but also inhibits the transcription of the bioBFDAGC operon resembling the de novo biotin synthetic pathway. EMSA-based screening failed to demonstrate that the biotin-related metabolite is involved in BioR-DNA interplay, which is consistent with our former observation with Brucella BioR. Our finding defined a complex regulatory network for biotin

Effect of Vermicompost, Sulfur and Thiobacillus on Some Soil Physico-chemical Properties, Yield and Yield Components of Maize (Zea mays L. in Jovain District

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Mahmmud Ahmadi

2018-02-01

Full Text Available Introduction The excessive use of chemical fertilizers causes environmental pollution that is led to imbalance of essential elements in agricultural production system. Organic matter application as compost in the soil can improve chemical quality and biochemical properties that increase essential elements for plant nutrition. Application of organic manure can significantly increase the soil aggregate as well. Reported that application of 7 ton ha-1 of vermicompost increased number of leaves, stem dry weight, and corn plant height as compared to control and water holding capacity increases. Sulphur in plant is near to phosphorus (0.2%. Sulphur deficiency cause severe reduction in plant growth and due to participation in protein building and its deficiency cause yellowish in younger leaves. Sulphur can be applied as elemental sulphur, with ammonium and super phosphate to the soil. Iran is situated in arid and semi arid region of the world and need to reduce the pH with sulphur application due to high pH above 8 in some parts. The aim of this research was to study the effect of above factors in yield and yield components of maize and reducing environmental pollution. Materials and Methods This research carried out at 2012 in Jovein Distract suberb of Sabzevar city. Before conducting the research soil sample were collected from 0-30 cm depth and physical and chemical properties of the soil were estimated. Treatments including sulphur, thiobacillus and vermicompost were applied to soil and well mixed with soil before sowing. Each plot consists of five rows with six m length by 80 cm from each other. Seeds were sown at the depth of five cm and 20 cm from each other. This research carried out as a factorial experiment on the basis of randomized complete block design. In this research three factors including elemental sulphur, vermicompost and thiobacillus were used with three replications. Elemental sulphur in three levels (control, 500 kg ha-1 and

Growth of Thiobacillus ferrooxidans on elemental sulfur

International Nuclear Information System (INIS)

Espejo, R.T.; Romero, P.

1987-01-01

Growth kinetics of Thiobacillus ferrooxidans in batch cultures, containing prills of elementary sulfur as the sole energy source, were studied by measuring the incorporation of radioactive phosphorus in free and adsorbed bacteria. The data obtained indicate an initial exponential growth of the attached bacteria until saturation of the susceptible surface was reached, followed by a linear release of free bacteria due to successive replication of a constant number of adsorbed bacteria. These adsorbed bacteria could continue replication provided the colonized prills were transferred to fresh medium each time the stationary phase was reached. The bacteria released from the prills were unable to multiply, and in the medium employed they lost viability with a half-live of 3.5 days. The spreading of the progeny on the surface was followed by staining the bacteria on the prills with crystal violet; this spreading was not uniform but seemed to proceed through distortions present in the surface. The specific growth rate of T. ferrooxidans ATCC 19859 was about 0.5 day -1 , both before and after saturation of the sulfur surface. The growth of adsorbed and free bacteria in medium containing both ferrous iron and elementary sulfur indicated that T. ferrooxidans can simultaneously utilize both energy sources

Evaluation of the Effect of Sulfur Application and Thiobacillus on Some Soil Chemical Characteristics and Yield of Canola in Wheat-Canola Rotation System

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H. Besharati

2016-09-01

Full Text Available Introduction: After soybean and palm oil, canola is third important oil seed in the world which belongs to the genus Brassicaceae, that its seeds contain about 40% oil. The per capita consumption of oil in Iran is about 14 kg, so approximately 900 thousand tons of oil will be required for each year. However, only less than 10% of this oil is produced in the country. In recent years, special attention has been paid to canola cultivation in order to increase oil production, so during recent years an apparent increase in canola cultivated lands is significant. In most of these canola cultivated lands, the soil is calcareous therefore; some available nutrients such as phosphorus, iron and zinc are less than the amounts required by plants. Increasing qualitative and quantitative yield of canola in calcareous soils is a priority to canola cultivation improvement. Sulfur plays an important role in oil content of oily seed crops. On the other hands sulfur oxidation in calcareous soils can improve some nutrients availability. The present study was designed to investigate the effect of sulfur on yield, oil content and nutrients uptake and also its impact on soil chemical properties with 8 treatments, in 3 replications. Materials and Methods: This study was conducted in Ekbatan research station in Hamedan province for 2 years as completely randomized block design with 8 treatments and 3 repetitions. The treatments were: T1: Control (Without sulfur and Thiobacillus, T2: Application of 150 kg sulfur per ha, T3: T2+ Thiobacillus inoculums (2% of applied sulfur, T4: Application of 300 kg sulfur per ha, T5: T4+ Thiobacillus inoculums (2% of applied sulfur, T6: Application of 600 kg sulfur per ha, T7: T6+ Thiobacillus inoculums (2% of applied sulfur T8: Fertilizing based on soil test without sulfur and Thiobacillus. Thiobacillus inoculant containing about 107 cells of Thiobacillus bacteria which belonged to neutrophile Thiobacilli were prepared at soil biology

Short communication: Adverse effect of surface-active reagents on the bioleaching of pyrite and chalcopyrite by Thiobacillus ferrooxidans.

Science.gov (United States)

Huerta, G; Escobar, B; Rubio, J; Badilla-Ohlbaum, R

1995-09-01

Oxidation of Fe(II) iron and bioleaching of pyrite and chalcopyrite by Thiobacillus ferrooxidans was adversely affected by isopropylxanthate, a flotation agent, and by LIX 984, a solvent-extraction agent, each at ≤ 1 g/l. The reagents/l were adsorbed on the bacterial surface, decreasing the bacteria's development and preventing biooxidation. Both reagents inhibited the bioleaching of pyrite and LIX 984 also inhibited the bioleaching of chalcopyrite.

Dicty_cDB: Contig-U05414-1 [Dicty_cDB

Lifescience Database Archive (English)

Full Text Available NA clone ZM... 76 1e-18 CP001071_756( CP001071 |pid:none) Akkermansia muciniphila ATCC BAA... 89 1e-18 AE017...CP000472 |pid:none) Shewanella piezotolerans WP3, com... 92 2e-17 AM286415_3721( AM286415 |pid:none) Yersini...lin,... 50 2e-06 AM494945_19( AM494945 |pid:none) Leishmania braziliensis chromosom... 55 5e-06 AP00725...0_22( DQ226510 |pid:none) Thellungiella halophila clone ThB... 94 2e-23 CP000116_2432( CP000116 |pid:none) Thiobacillus denitrificans...-17 CP000934_3554( CP000934 |pid:none) Cellvibrio japonicus Ueda107, c... 83 3e-17 AB274914_1( AB274914 |pid:none) Pleurochrysi

A novel mineral flotation process using Thiobacillus ferrooxidans.

Science.gov (United States)

Nagaoka, T; Ohmura, N; Saiki, H

1999-08-01

Oxidative leaching of metals by Thiobacillus ferrooxidans has proven useful in mineral processing. Here, we report on a new use for T. ferrooxidans, in which bacterial adhesion is used to remove pyrite from mixtures of sulfide minerals during flotation. Under control conditions, the floatabilities of five sulfide minerals tested (pyrite, chalcocite, molybdenite, millerite, and galena) ranged from 90 to 99%. Upon addition of T. ferrooxidans, the floatability of pyrite was significantly suppressed to less than 20%. In contrast, addition of the bacterium had little effect on the floatabilities of the other minerals, even when they were present in relatively large quantities: their floatabilities remained in the range of 81 to 98%. T. ferrooxidans thus appears to selectively suppress pyrite floatability. As a consequence, 77 to 95% of pyrite was removed from mineral mixtures while 72 to 100% of nonpyrite sulfide minerals was recovered. The suppression of pyrite floatability was caused by bacterial adhesion to pyrite surfaces. When normalized to the mineral surface area, the number of cells adhering to pyrite was significantly larger than the number adhering to other minerals. These results suggest that flotation with T. ferrooxidans may provide a novel approach to mineral processing in which the biological functions involved in cell adhesion play a key role in the separation of minerals.

Molecular origins and consequences of High-800 LH2 in Roseobacter denitrificans.

Science.gov (United States)

Duquesne, Katia; Blanchard, Cecile; Sturgis, James N

2011-08-09

Roseobacter denitrificans is a marine bacterium capable of using a wide variety of different metabolic schemes and in particular is an anoxygenic aerobic photosynthetic bacterium. In the work reported here we use a deletion mutant that we have constructed to investigate the structural origin of the unusual High-800 light-harvesting complex absorption in this bacterium. We suggest that the structure is essentially unaltered when compared to the usual nonameric complexes but that a change in the environment of the C(13:1) carbonyl group is responsible for the change in spectrum. We tentatively relate this change to the presence of a serine residue in the α-polypeptide. Surprisingly, the low spectral overlap between the peripheral and core light-harvesting systems appears not to compromise energy collection efficiency too severely. We suggest that this may be at the expense of maintaining a low antenna size. © 2011 American Chemical Society

Microbial reduction of SO{sub 2} and NO{sub x} as a means of by-product recovery/disposal from regenerable processes for the desulfurization of flue gas. Technical progress report, September 11, 1992--December 11, 1992

Energy Technology Data Exchange (ETDEWEB)

Sublette, K.L.

1992-12-31

With the continual increase in the utilization of high sulfur and high nitrogen containing fossil fuels, the release of airborne pollutants into the environment has become a critical problem. The fuel sulfur is converted to SO{sub 2} during combustion. Fuel nitrogen and a fraction of the nitrogen from the combustion air are converted to nitric oxide and nitrogen dioxide, NO{sub x}. For the past five years Combustion Engineering (now Asea Brown Boveri or ABB) and, since 1986, the University of Tulsa (TU) have been investigating the oxidation of H{sub 2}S by the facultatively anaerobic and autotrophic bacterium Thiobacillus denitrificans and have developed a process, concept for the microbial removal of H{sub 2}S from a gas stream the simultaneous removal of SO{sub 2} and NO by D. desulfuricans and T. denitrificans co-cultures and cultures-in-series was demonstrated. These systems could not be sustained due to NO inhibition of D. desulfuricans. However, a preliminary economic analysis has shown that microbial reduction of SO{sub 2} to H{sub 2}S with subsequent conversion to elemental sulfur by the Claus process is both technically and economically feasible if a less expensive carbon and/or energy source can be found. It has also been demonstrated that T. denitrificans can be grown anaerobically on NO(g) as a terminal electron acceptor with reduction to elemental nitrogen. Microbial reduction of NO{sub x} is a viable process concept for the disposal of concentrated streams of NO{sub x} as may be produced by certain regenerable processes for the removal of SO{sub 2} and NO{sub x} from flue gas.

Structure/function relationship of the rusticyanin among thiobacillus ferroxidans: from the fermenter to the crystal; Relations structure/fonction de la rusticyanine chez thiobacillus ferrooxidans: du fermenteur au cristal

Energy Technology Data Exchange (ETDEWEB)

Nunzi, F.

1996-09-23

The commercial extraction of copper and uranium from ores by microbial leaching turns to account the iron oxidation capacity of Thiobacillus ferroxidans. The iron oxidation involves an electron transport chain localized in the peri-plasmic space of the cell. The aim of our work is to study the structure-function relationships of rusticyanin, the most important component of this respiratory chain. Rusticyanin is a blue copper protein and has been characterized from a new strain of Thilbacillus ferrooxidans. A preliminary electrochemical study has been made with a new modified-gold electrode and we have examined, in particular, the pH dependence of the high redox potential of rusticyanin. Its amino acid sequence has been determined and a comparison with two other rusticyanin sequences, isolated from different strains, shows a high degree of homology. A structural alignment with six other blue copper proteins allows to propose four residues as copper ligands, His 84, Cys 138, His 143 and Met 148. The supposed factors responsible for the high redox potential of rusticyanin are discussed. (author)

Genome-wide discovery of putative sRNAs in Paracoccus denitrificans expressed under nitrous oxide emitting conditions.

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Hannah Gaimster

2016-11-01

Full Text Available Nitrous oxide (N2O is a stable, ozone depleting greenhouse gas. Emissions of N2O into the atmosphere continue to rise, primarily due to the use of nitrogen-containing fertilizers by soil denitrifying microbes. It is clear more effective mitigation strategies are required to reduce emissions. One way to help develop future mitigation strategies is to address the currently poor understanding of transcriptional regulation of the enzymes used to produce and consume N2O. With this ultimate aim in mind we performed RNA-seq on a model soil denitrifier, Paracoccus denitrificans, cultured anaerobically under high N2O and low N2O emitting conditions, and aerobically under zero N2O emitting conditions to identify small RNAs (sRNAs with potential regulatory functions transcribed under these conditions. sRNAs are short (∼40–500 nucleotides non-coding RNAs that regulate a wide range of activities in many bacteria. 167 sRNAs were identified throughout the P. denitrificans genome which are either present in intergenic regions or located antisense to ORFs. Furthermore, many of these sRNAs are differentially expressed under high N2O and low N2O emitting conditions respectively, suggesting they may play a role in production or reduction of N2O. Expression of 16 of these sRNAs have been confirmed by RT-PCR. 90% of the sRNAs are predicted to form secondary structures. Predicted targets include transporters and a number of transcriptional regulators. A number of sRNAs were conserved in other members of the α-proteobacteria. Better understanding of the sRNA factors which contribute to expression of the machinery required to reduce N2O will, in turn, help to inform strategies for mitigation of N2O emissions.

Integration of heterologous DNA into the genome of Paracoccus denitrificans is mediated by a family of IS1248-related elements and a second type of integrative recombination event

NARCIS (Netherlands)

Van Spanning, R J; Reijnders, W N; Stouthamer, A.H.

All members of the IS1248 family residing in the genome of Paracoccus denitrificans have been isolated by using a set of insertion sequence entrapment vectors. The family consists of five closely related members that integrate the entrapment vectors at distinct sites. One of these, IS1248b, was

Evaluating Maize Yield and the Quality of Response to Vermicompost, in Thiobacillus and Foliar Application of Fe and Zn

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Elnaz Davaran Hagh

2017-08-01

Full Text Available Introduction Half of the world's population suffers from micronutrients malnutrition. Use of bio-fertilizers in sustainable agricultural systems is important in production and enables plants to absorb more water from soil and improves plant nutrient uptake and photosynthesis. Benefits of vermicompost application in agriculture is due to its content of organic matter, plant nutrients and plant growth promotion. Vermicompost increases the absorption and transition of nutrients from soil to roots and improves plant growth (Simsek-Ersahin, 2011. Zn and Fe application is highly important; foliar application causes faster and higher absorption rate and cures deficiencies symptoms (Ghaffari et al., 2010. Thiobacillus is a chemolithotroph bacterium, receiving energy from sulfur oxidation. This bacterium acidifies microcites in the rhizosphere, increasing the availability of nutrients to plant roots (Kaya et al., 2009. Regarding the benefits of integrated nutrient management, this experiment was conducted with the aim of testing the effects of Fe and Zn foliar spraying, Thiobacillu sthiooxidans inoculation and vermicompost application on growth, yield and bio fortification of popcorn maize. Materials and methods This experiment was conducted in 2012 at the research field of Islamic Azad University, Tabriz branch, Iran. The experiment was conducted in factorial in the form of a randomized complete block design with three replications and four factors: vermicompost application in soil (0 and 2 t.ha-1, applied in strip form below the seeds before cultivation, inoculation with Thiobacillus thiooxidans, with a population of 108cfu.g-1. Sulfur was inoculated with T. thiooxidans prior to application. Fe chelate foliar application (without spraying and two times spraying of 0.002 concentration of 13% Fe chelate and Zn chelate foliar application (without spraying and two times spraying of 0.002 concentration of 15% Zn chelate. Maize seeds (Zea mays L. var

Resonance Raman spectroscopy of amicyanin, a blue copper protein from Paracoccus denitrificans

International Nuclear Information System (INIS)

Sharma, K.D.; Loehr, T.M.; Sanders-Loehr, J.; Husain, M.; Davidson, V.L.

1988-01-01

The copper binding site of amicyanin from Paracoccus denitrificans has been examined by resonance Raman spectroscopy. The pattern of vibrational modes is clearly similar to those of the blue copper proteins azurin and plastocyanin. Intense resonance-enhanced peaks are observed at 377, 392, and 430 cm-1 as well as weaker overtones and combination bands in the high frequency region. Most of the peaks below 500 cm-1 shift 0.5-1.5 cm-1 to lower energy when the protein is exposed to D 2 O. Based on the pattern of conserved amino acids, the axial type EPR spectrum, and the resonance Raman spectrum, it is proposed that the copper binding site in amicyanin contains a Cu(II) ion in a distorted trigonal planar geometry with one cysteine and two histidine ligands and an axial methionine ligand at a considerably longer distance. Furthermore, the presence of multiple intense Raman peaks in the 400 cm-1 region which are sensitive to deuterium substitution leads to the conclusion that the Cu-S stretch is coupled with internal ligand vibrational modes and that the sulfur of the cysteine ligand is likely to be hydrogen-bonded to the polypeptide backbone

Defluviimonas denitrificans gen. nov., sp. nov., and Pararhodobacter aggregans gen. nov., sp. nov., non-phototrophic Rhodobacteraceae from the biofilter of a marine aquaculture

DEFF Research Database (Denmark)

Foesel, Bärbel U.; Drake, Harold L.; Schramm, Andreas

2011-01-01

Three Gram-negative bacterial strains were isolated from the biofilter of a recirculating marine aquaculture. They were non-pigmented rods, mesophiles, moderately halophilic, and showed chemoorganoheterotrophic growth on various sugars, fatty acids, and amino acids, with oxygen as electron acceptor......, but clearly separate from, the genera Rhodobacter, Rhodovulum, and Rhodobaca. Based on morphological, physiological, and 16S rRNA-based phylogenetic characteristics, the isolated strains are proposed as new species of two novel genera, Defluviimonas denitrificans gen. nov., sp. nov. (type strain D9-3T = DSM...

Effect of Thiobacillus thioparus 1904 and sulphur addition on odour emission during aerobic composting.

Science.gov (United States)

Gu, Wenjie; Sun, Wen; Lu, Yusheng; Li, Xia; Xu, Peizhi; Xie, Kaizhi; Sun, Lili; Wu, Hangtao

2018-02-01

The effects of sulphur and Thiobacillus thioparus 1904 on odour emissions during composting were studied. Results indicated that the sulphur addition reduced the pH and decreased cumulative emission of ammonia and the nitrogen loss by 47.80% and 44.23%, respectively, but the amount of volatile sulphur compounds (VSCs) and the sulphur loss increased. The addition of T. thioparus 1904 effectively reduced the cumulative emissions of H 2 S, methyl sulphide, methanethiol, dimethyl disulphide and the sulphur loss by 33.24%, 81.24%, 32.70%, 54.22% and 54.24%, respectively. T. thioparus 1904 also limited the nitrogen loss. The combined application of sulphur and T. thioparus 1904 resulted in the greatest amount of nitrogen retention. The accumulation of ammonia emissions was reduced by 63.33%, and the nitrogen loss was reduced by 71.93%. The combined treatment did not increase the emission of VSCs. The application of sulphur and T. thioparus 1904 may help to control the odour of compost. Copyright © 2017. Published by Elsevier Ltd.

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

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Kang Zhao

2016-08-01

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

Denitrification performance of Pseudomonas denitrificans in a fluidized-bed biofilm reactor and in a stirred tank reactor

Energy Technology Data Exchange (ETDEWEB)

Cattaneo, C.; Nicolella, C.; Rovatti, M. [Department of Chemical and Process Engineering, Faculty of Engineering, University of Genoa, Via Opera Pia 15, 16145 Genoa (Italy)

2003-04-09

Denitrification of a synthetic wastewater containing nitrates and methanol as carbon source was carried out in two systems - a fluidized-bed biofilm reactor (FBBR) and a stirred tank reactor (STR) - using Pseudomonas denitrificans over a period of five months. Nitrogen loading was varied during operation of both reactors to assess differences in the response to transient conditions. Experimental data were analyzed to obtain a comparison of denitrification kinetics in biofilm and suspended growth reactors. The comparison showed that the volumetric degradation capacity in the FBBR (5.36 kg {sub N} . m{sup -3} . d{sup -1}) was higher than in the STR, due to higher biomass concentration (10 kg {sub BM} . m{sup -3} vs 1.2 kg {sub BM} m{sup -3}). (Abstract Copyright [2003], Wiley Periodicals, Inc.)

Construction of Methanol-Sensing Escherichia coli by the Introduction of a Paracoccus denitrificans MxaY-Based Chimeric Two-Component System.

Science.gov (United States)

Ganesh, Irisappan; Vidhya, Selvamani; Eom, Gyeong Tae; Hong, Soon Ho

2017-06-28

Escherichia coli was engineered to sense methanol by employing a chimeric two-component system (TCS) strategy. A chimeric MxaY/EnvZ (MxaYZ) TCS was constructed by fusing the Paracoccus denitrificans MxaY with the E. coli EnvZ. Real-time quantitative PCR analysis and GFP-based fluorescence analysis showed maximum transcription of ompC and the fluorescence at 0.01% of methanol, respectively. These results suggested that E. coli was successfully engineered to sense methanol by the introduction of chimeric MxaYZ. By using this strategy, various chimeric TCS-based bacterial biosensors can be constructed and used for the development of biochemical-producing recombinant microorganisms.

Crystallization and initial X-ray diffraction studies of the flavoenzyme NAD(P)H:(acceptor) oxidoreductase (FerB) from the soil bacterium Paracoccus denitrificans

International Nuclear Information System (INIS)

Klumpler, Tomáš; Sedláček, Vojtěch; Marek, Jaromír; Wimmerová, Michaela; Kučera, Igor

2010-01-01

The flavin-dependent enzyme FerB from P. denitrificans has been purified and both native and SeMet-substituted FerB have been crystallized. The two variants crystallized in two different crystallographic forms belonging to the monoclinic space group P2 1 and the orthorhombic space group P2 1 2 1 2, respectively. X-ray diffraction data were collected to 1.75 Å resolution for both forms. The flavin-dependent enzyme FerB from Paracoccus denitrificans reduces a broad range of compounds, including ferric complexes, chromate and most notably quinones, at the expense of the reduced nicotinamide adenine dinucleotide cofactors NADH or NADPH. Recombinant unmodified and SeMet-substituted FerB were crystallized under similar conditions by the hanging-drop vapour-diffusion method with microseeding using PEG 4000 as the precipitant. FerB crystallized in several different crystal forms, some of which diffracted to approximately 1.8 Å resolution. The crystals of native FerB belonged to space group P2 1 , with unit-cell parameters a = 61.6, b = 110.1, c = 65.2 Å, β = 118.2° and four protein molecules in the asymmetric unit, whilst the SeMet-substituted form crystallized in space group P2 1 2 1 2, with unit-cell parameters a = 61.2, b = 89.2, c = 71.5 Å and two protein molecules in the asymmetric unit. Structure determination by the three-wavelength MAD/MRSAD method is now in progress

Shifts in microbial community composition and function in the acidification of a lead/zinc mine tailings.

Science.gov (United States)

Chen, Lin-Xing; Li, Jin-Tian; Chen, Ya-Ting; Huang, Li-Nan; Hua, Zheng-Shuang; Hu, Min; Shu, Wen-Sheng

2013-09-01

In an attempt to link the microbial community composition and function in mine tailings to the generation of acid mine drainage, we simultaneously explored the geochemistry and microbiology of six tailings collected from a lead/zinc mine, i.e. primary tailings (T1), slightly acidic tailings (T2), extremely acidic tailings (T3, T4 and T5) and orange-coloured oxidized tailings (T6). Geochemical results showed that the six tailings (from T1 to T6) likely represented sequential stages of the acidification process of the mine tailings. 16S rRNA pyrosequencing revealed a contrasting microbial composition between the six tailings: Proteobacteria-related sequences dominated T1-T3 with relative abundance ranging from 56 to 93%, whereas Ferroplasma-related sequences dominated T4-T6 with relative abundance ranging from 28 to 58%. Furthermore, metagenomic analysis of the microbial communities of T2 and T6 indicated that the genes encoding key enzymes for microbial carbon fixation, nitrogen fixation and sulfur oxidation in T2 were largely from Thiobacillus and Acidithiobacillus, Methylococcus capsulatus, and Thiobacillus denitrificans respectively; while those in T6 were mostly identified in Acidithiobacillus and Leptospirillum, Acidithiobacillus and Leptospirillum, and Acidithiobacillus respectively. The microbial communities in T2 and T6 harboured more genes suggesting diverse metabolic capacities for sulfur oxidation/heavy metal detoxification and tolerating low pH respectively. © 2013 John Wiley & Sons Ltd and Society for Applied Microbiology.

Study of the selenite reduction in Rhodobacter sphaeroides f. sp. denitrificans

International Nuclear Information System (INIS)

Bernier-Pierru, B.

2006-05-01

Selenium is an essential element for all living organisms at the low level; however it becomes toxic and mutagenic at higher concentrations. The predominant forms of selenium in natural environments are selenate and selenite which are toxic. Bacteria can use several mechanisms of detoxification such as methylation in volatile compounds or reduction in elemental selenium. In this way, our model, Rhodobacter sphaeroides f. sp. denitrificans, is able to reduce selenite into selenium. We have combined biochemical and molecular approaches to better characterize the mechanism and protagonists of this reduction. After studying the physiological response of the bacterium in the presence of selenite, we screened a transposon library in order to isolate mutants with a weakened reduction ability. Two of these selected mutants are affected in genes involved in the molybdenum cofactor synthesis, moaA and mogA. Several reductases, the molybdo enzymes, required this cofactor. Furthermore the addition of tungsten, a competitor for the molybdenum, in the culture medium, dramatically reduces the rate of selenite reduction. These results strongly suggest that a molybdo enzyme is involved in one of the selenite reduction pathways. The potential role of different proteins has been investigated, especially for the nitrate reductase, the DMSO reductase and the biotin sulfoxide reductase. We have also selected a mutant affected in the smoM gene which encodes a peri-plasmic component of a TRAP transporter. The phenotype of this mutant suggests the involvement of this transporter in the selenite import. (author)

Immobilization of microorganisms. Part 1. Preparation of immobilized Lactobacillus bulgaricus

Energy Technology Data Exchange (ETDEWEB)

Lee, K H

1981-01-01

The immobilization of Lactobacillus bulgaricus on polyacrylamide and on alginate beads was investigated. The most active immobilized cells were obtained by entrapment in Ca alginate beads. These immobilized microbial cells, when introduced into 4.5% lactose solution and whey solution showed maximum relative activity of 28% for lactose and 18% for whey compared to free cells.

GeoChip-based analysis of the microbial community functional structures in simultaneous desulfurization and denitrification process.

Science.gov (United States)

Yu, Hao; Chen, Chuan; Ma, Jincai; Liu, Wenzong; Zhou, Jizhong; Lee, Duu-Jong; Ren, Nanqi; Wang, Aijie

2014-07-01

The elemental sulfur (S°) recovery was evaluated in the presence of nitrate in two development models of simultaneous desulfurization and denitrification (SDD) process. At the loading rates of 0.9 kg S/(m³·day) for sulfide and 0.4 kg N/(m³·day) for nitrate, S° conversion rate was 91.1% in denitrifying sulfide removal (DSR) model which was higher than in integrated simultaneous desulfurization and denitrification (ISDD) model (25.6%). A comprehensive analysis of functional diversity, structure and metabolic potential of microbial communities was examined in two models by using functional gene array (GeoChip 2.0). GeoChip data indicated that diversity indices, community structure, and abundance of functional genes were distinct between two models. Diversity indices (Simpson's diversity index (1/D) and Shannon-Weaver index (H')) of all detected genes showed that with elevated influent loading rate, the functional diversity decreased in ISDD model but increased in DSR model. In contrast to ISDD model, the overall abundance of dsr genes was lower in DSR model, while some functional genes targeting from nitrate-reducing sulfide-oxidizing bacteria (NR-SOB), such as Thiobacillus denitrificans, Sulfurimonas denitrificans, and Paracoccus pantotrophus were more abundant in DSR model which were highly associated with the change of S(0) conversion rate obtained in two models. The results obtained in this study provide additional insights into the microbial metabolic mechanisms involved in ISDD and DSR models, which in turn will improve the overall performance of SDD process. Copyright © 2014. Published by Elsevier B.V.

A kinetic study of the depyritization of oil shale HCl-kerogen concentrate by Thiobacillus ferrooxidans at different temperatures

Directory of Open Access Journals (Sweden)

OLGA CVETKOVIC

2003-05-01

Full Text Available The results of kinetic studies of bacterial depyritization of HCl-kerogen concentrate of Aleksinac (Serbia oil shale by the chemolithoautotrophic thionic bacteria Thiobacillus ferrooxidans under discontinuous laboratory conditions at various temperatures (0, 20, 28 and 37°C at a pH of ca. 1.5 are presented in this paper. Low pH prevents the occurrence of the precipitation of iron(III-ion hydrolysis products on the substrate particles and thereby reduces the process efficiency. Bacterial depyritization is developed as per kinetics of the first order. The activation energy which points to a successive mechanism of pyrite biooxidation, was computed from the Arrhenius plot. The biochemical kinetics indicators point to a high affinity of the bacteria toward pyrite but small values of Vmax, which are probably the result of decelerated metabolic processes due to the low pH value of the environment resp. the large difference of the pH between the external medium and the cell interior.

Limb immobilization and corticobasal syndrome.

Science.gov (United States)

Graff-Radford, Jonathan; Boeve, Bradley F; Drubach, Daniel A; Knopman, David S; Ahlskog, J Eric; Golden, Erin C; Drubach, Dina I; Petersen, Ronald C; Josephs, Keith A

2012-12-01

Recently, we evaluated two patients with corticobasal syndrome (CBS) who reported symptom onset after limb immobilization. Our objective was to investigate the association between trauma, immobilization and CBS. The charts of forty-four consecutive CBS patients seen in the Mayo Clinic Alzheimer Disease Research Center were reviewed with attention to trauma and limb immobilization. 10 CBS patients (23%) had immobilization or trauma on the most affected limb preceding the onset or acceleration of symptoms. The median age at onset was 61. Six patients manifested their first symptoms after immobilization from surgery or fracture with one after leg trauma. Four patients had pre-existing symptoms of limb dysfunction but significantly worsened after immobilization or surgery. 23 percent of patients had immobilization or trauma of the affected limb. This might have implications for management of CBS, for avoiding injury, limiting immobilization and increasing movement in the affected limb. Copyright © 2012 Elsevier Ltd. All rights reserved.

Status of plutonium ceramic immobilization processes and immobilization forms

International Nuclear Information System (INIS)

Ebbinghaus, B.B.; Van Konynenburg, R.A.; Vance, E.R.; Jostsons, A.

1996-01-01

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 ampersand 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 2 O 7 ), the desired actinide host phase, with lesser amounts of hollandite (BaAl 2 Ti 6 O 16 ) and rutile (TiO 2 ). Alternative actinide host phases are also being considered. These include pyrochlore (Gd 2 Ti 2 O 7 ), zircon (ZrSiO 4 ), and monazite (CePO 4 ), to name a few of the most promising. R ampersand D activities to address important technical issues are discussed. Primarily these include moderate scale hot press fabrications with plutonium, direct loading of PuO 2 powder, cold press and sinter fabrication methods, and immobilization form formulation issues

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.

Enzyme Immobilization: An Overview on Methods, Support Material, and Applications of Immobilized Enzymes.

Science.gov (United States)

Sirisha, V L; Jain, Ankita; Jain, Amita

Immobilized enzymes can be used in a wide range of processes. In recent years, a variety of new approaches have emerged for the immobilization of enzymes that have greater efficiency and wider usage. During the course of the last two decades, this area has rapidly expanded into a multidisciplinary field. This current study is a comprehensive review of a variety of literature produced on the different enzymes that have been immobilized on various supporting materials. These immobilized enzymes have a wide range of applications. These include applications in the sugar, fish, and wine industries, where they are used for removing organic compounds from waste water. This study also reviews their use in sophisticated biosensors for metabolite control and in situ measurements of environmental pollutants. Immobilized enzymes also find significant application in drug metabolism, biodiesel and antibiotic production, bioremediation, and the food industry. The widespread usage of immobilized enzymes is largely due to the fact that they are cheaper, environment friendly, and much easier to use when compared to equivalent technologies. © 2016 Elsevier Inc. All rights reserved.

Assessing attitudes toward spinal immobilization.

Science.gov (United States)

Bouland, Andrew J; Jenkins, J Lee; Levy, Matthew J

2013-10-01

Prospective studies have improved knowledge of prehospital spinal immobilization. The opinion of Emergency Medical Services (EMS) providers regarding spinal immobilization is unknown, as is their knowledge of recent research advances. To examine the attitudes, knowledge, and comfort of prehospital and Emergency Department (ED) EMS providers regarding spinal immobilization performed under a non-selective protocol. An online survey was conducted from May to July of 2011. Participants were drawn from the Howard County Department of Fire and Rescue Services and the Howard County General Hospital ED. The survey included multiple choice questions and responses on a modified Likert scale. Correlation analysis and descriptive data were used to analyze results. Comfort using the Kendrick Extrication Device was low among ED providers. Experienced providers were more likely to indicate comfort using this device. Respondents often believed that spinal immobilization is appropriate in the management of penetrating trauma to the chest and abdomen. Reported use of padding decreased along with the frequency with which providers practice and encounter immobilized patients. Respondents often indicated that they perform spinal immobilization due solely to mechanism of injury. Providers who feel as if spinal immobilization is often performed unnecessarily were more likely to agree that immobilization causes an unnecessary delay in patient care. The results demonstrate the need for improved EMS education in the use of the Kendrick Extrication Device, backboard padding, and spinal immobilization in the management of penetrating trauma. The attitudes highlighted in this study are relevant to the implementation of a selective spinal immobilization protocol. Copyright © 2013 Elsevier Inc. All rights reserved.

Exploring the Molecular Basis for Selective Binding of Homoserine Dehydrogenase from Mycobacterium leprae TN toward Inhibitors: A Virtual Screening Study

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Dongling Zhan

2014-01-01

Full Text Available Homoserine dehydrogenase (HSD from Mycobacterium leprae TN is an antifungal target for antifungal properties including efficacy against the human pathogen. The 3D structure of HSD has been firmly established by homology modeling methods. Using the template, homoserine dehydrogenase from Thiobacillus denitrificans (PDB Id 3MTJ, a sequence identity of 40% was found and molecular dynamics simulation was used to optimize a reliable structure. The substrate and co-factor-binding regions in HSD were identified. In order to determine the important residues of the substrate (l-aspartate semialdehyde (l-ASA binding, the ASA was docked to the protein; Thr163, Asp198, and Glu192 may be important because they form a hydrogen bond with HSD through AutoDock 4.2 software. neuraminidaseAfter use of a virtual screening technique of HSD, the four top-scoring docking hits all seemed to cation–π ion pair with the key recognition residue Lys107, and Lys207. These ligands therefore seemed to be new chemotypes for HSD. Our results may be helpful for further experimental investigations.

Immobilization of cellulase by radiation polymerization

International Nuclear Information System (INIS)

Kumakura, M.; Kaetsu, I.

1983-01-01

Immobilization of cellulase by radiation polymerization at low temperatures was studied. The enzymatic activity of immobilized cellulase pellets varied with the monomer, enzyme concentration, and the thickness of immobilized cellulase pellets. The optimum monomer concentration in the immobilization of cellulase was 30-50% at the pellet thickness of 1.0 mm, in which the enzymatic activity was 50%. The enzymatic activity of immobilized cellulase pellets was examined using various substrates such as cellobiose, carboxymethylcellulose, and paper pretreated by radiation. It was found that irradiated paper can be hydrolyzed by immobilized cellulase pellets. (author)

Biosynthesis of poly-3-hydroxybutyrate (PHB) from glycerol by Paracoccus denitrificans in a batch bioreactor: effect of process variables.

Science.gov (United States)

Kalaiyezhini, D; Ramachandran, K B

2015-01-01

In this study, the kinetics of poly-3-hydroxybutyrate (PHB) biosynthesis from glycerol by Paracoccus denitrificans DSMZ 413 were explored in a batch bioreactor. Effects of inorganic and organic nitrogen source, carbon to nitrogen ratio, and other process variables such as pH, aeration, and initial glycerol concentration on PHB production were investigated in a 2.5-L bioreactor. Yeast extract was found to be the best nitrogen source compared to several organic nitrogen sources tested. At pH 6, specific growth rate, product formation rate, and accumulation of PHB within the cell were maximum. Specific growth rate increased with increase in oxygen transfer rate, but moderate oxygen transfer rate promoted PHB production. High glycerol concentration inhibited specific product formation rate but not growth. High initial carbon/nitrogen (C/N) ratio favored PHB accumulation and its productivity. At a C/N ratio of 21.4 (mol mol(-1)), 10.7 g L(-1) of PHB corresponding to 72% of cell dry weight was attained.

Immobilized waste leaching

International Nuclear Information System (INIS)

Suarez, A.A.

1989-01-01

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) [pt

Plutonium Disposition by Immobilization

International Nuclear Information System (INIS)

Gould, T.; DiSabatino, A.; Mitchell, M.

2000-01-01

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

Membranes suited for immobilizing biomolecules

NARCIS (Netherlands)

2009-01-01

The present invention relates to flow-through membranes suitable for the immobilization of biomols., methods for the prepn. of such membranes and the use of such membranes for the immobilization of biomols. and subsequent detection of immobilized biomols. The invention concerns a flow-through

Immobilized enzymes and cells

Energy Technology Data Exchange (ETDEWEB)

Bucke, C; Wiseman, A

1981-04-04

This article reviews the current state of the art of enzyme and cell immobilization and suggests advances which might be made during the 1980's. Current uses of immobilized enzymes include the use of glucoamylase in the production of glucose syrups from starch and glucose isomerase in the production of high fructose corn syrup. Possibilities for future uses of immobilized enzymes and cells include the utilization of whey and the production of ethanol.

Microorganism immobilization

Science.gov (United States)

Compere, Alicia L.; Griffith, William L.

1981-01-01

Live metabolically active microorganisms are immobilized on a solid support by contacting particles of aggregate material with a water dispersible polyelectrolyte such as gelatin, crosslinking the polyelectrolyte by reacting it with a crosslinking agent such as glutaraldehyde to provide a crosslinked coating on the particles of aggregate material, contacting the coated particles with live microorganisms and incubating the microorganisms in contact with the crosslinked coating to provide a coating of metabolically active microorganisms. The immobilized microorganisms have continued growth and reproduction functions.

An overview of technologies for immobilization of enzymes and surface analysis techniques for immobilized enzymes

Science.gov (United States)

Mohamad, Nur Royhaila; Marzuki, Nur Haziqah Che; Buang, Nor Aziah; Huyop, Fahrul; Wahab, Roswanira Abdul

2015-01-01

The current demands of sustainable green methodologies have increased the use of enzymatic technology in industrial processes. Employment of enzyme as biocatalysts offers the benefits of mild reaction conditions, biodegradability and catalytic efficiency. The harsh conditions of industrial processes, however, increase propensity of enzyme destabilization, shortening their industrial lifespan. Consequently, the technology of enzyme immobilization provides an effective means to circumvent these concerns by enhancing enzyme catalytic properties and also simplify downstream processing and improve operational stability. There are several techniques used to immobilize the enzymes onto supports which range from reversible physical adsorption and ionic linkages, to the irreversible stable covalent bonds. Such techniques produce immobilized enzymes of varying stability due to changes in the surface microenvironment and degree of multipoint attachment. Hence, it is mandatory to obtain information about the structure of the enzyme protein following interaction with the support surface as well as interactions of the enzymes with other proteins. Characterization technologies at the nanoscale level to study enzymes immobilized on surfaces are crucial to obtain valuable qualitative and quantitative information, including morphological visualization of the immobilized enzymes. These technologies are pertinent to assess efficacy of an immobilization technique and development of future enzyme immobilization strategies. PMID:26019635

Supramolecular protein immobilization on lipid bilayers

NARCIS (Netherlands)

Bosmans, R.P.G.; Hendriksen, W.E.; Verheijden, Mark Lloyd; Eelkema, R.; Jonkheijm, Pascal; van Esch, J.H.; Brunsveld, Luc

2015-01-01

Protein immobilization on surfaces, and on lipid bilayers specifically, has great potential in biomolecular and biotechnological research. Of current special interest is the immobilization of proteins using supramolecular noncovalent interactions. This allows for a reversible immobilization and

Immobilization of enzymes by radiation

International Nuclear Information System (INIS)

Kaetsu, I.; Kumakura, M.; Yoshida, M.; Asano, M.; Himei, M.; Tamura, M.; Hayashi, K.

1979-01-01

Immobilization of various enzymes was performed by radiation-induced polymerization of glass-forming monomers at low temperatures. Alpha-amylase and glucoamylase were effectively immobilized in hydrophilic polymer carrier such as poly(2-hydroxyethyl methacrylate) and also in rather hydrophobic carrier such as poly(tetraethylene-glycol diacrylate). Immobilized human hemoglobin underwent the reversible oxygenation concomitantly with change of oxygen concentration outside of the matrices. (author)

Immobilized fluid membranes for gas separation

Science.gov (United States)

Liu, Wei; Canfield, Nathan L; Zhang, Jian; Li, Xiaohong Shari; Zhang, Jiguang

2014-03-18

Provided herein are immobilized liquid membranes for gas separation, methods of preparing such membranes and uses thereof. In one example, the immobilized membrane includes a porous metallic host matrix and an immobilized liquid fluid (such as a silicone oil) that is immobilized within one or more pores included within the porous metallic host matrix. The immobilized liquid membrane is capable of selective permeation of one type of molecule (such as oxygen) over another type of molecule (such as water). In some examples, the selective membrane is incorporated into a device to supply oxygen from ambient air to the device for electrochemical reactions, and at the same time, to block water penetration and electrolyte loss from the device.

Effects of immobilization on spermiogenesis

Science.gov (United States)

Meitner, E. R.

1980-01-01

The influence of immobilization stress on spermiogenesis in rats was investigated. After 96 hour immobilization, histological changes began to manifest themselves in the form of practically complete disappearance of cell population of the wall of seminiferous tubule as well as a markedly increased number of cells with pathologic mitoses. Enzymological investigations showed various changes of activity (of acid and alkaline phosphatase and nonspecific esterase) in the 24, 48, and 96 hour immobilization groups.

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 ®}.

Remote handling in the Plutonium Immobilization Project: Plutonium conversion and first stage immobilization

International Nuclear Information System (INIS)

Brault, J.R.

2000-01-01

Since the break up of the Soviet Union at the end of the Cold War, the United States and Russia have been negotiating ways to reduce their nuclear stockpiles. Economics is one of the reasons behind this, but another important reason is safeguarding these materials from unstable organizations and countries. With the downsizing of the nuclear stockpiles, large quantities of plutonium are being declared excess and must be safely disposed of. The Savannah River Site (SRS) has been selected as the site where the immobilization facility will be located. Conceptual design and process development commenced in 1998. SRS will immobilize excess plutonium in a ceramic waste form and encapsulate it in vitrified high level waste in the Defense Waste Processing Facility (DWPF) canister. These canisters will then be interred in the national repository at Yucca Mountain, New Mexico. The facility is divided into three distinct operating areas: Plutonium Conversion, First Stage Immobilization, and Second Stage Immobilization. This paper will discuss the first two operations

Immobilized cells of Candida rugosa possessing fumarase activity

Energy Technology Data Exchange (ETDEWEB)

Yang, L.; Zhone, L.

1980-01-01

Immobilized cells of C. rugosa that possessed fumarase activity were prepared by different methods; the most active immobilized cells were entrapped in polyacrylamide gels. The effects of pH temperature, and divalent cations on the fumarase activity of both immobilized and native cells were the same. Mn/sup 2 +/, Mg/sup 2 +/, Ca/sup 2 +/, and Fe/sup 2 +/ did not protect the immobilized enzyme against thermal inactivation. The activity of immobilized fumarase remained constant during 91 days of storage of 4-6 degrees. The immobilized cell column was used for the continuous production of L-malic acid from 1M fumarate at 30 degrees and pH 8.5. The immobilized column operated steadily for 2 months. Half life of the immobilized fumarase at 30 degrees was 95 days.

Immobilization needs and technology programs

International Nuclear Information System (INIS)

Gray, L.W.; Kan, T.; Shaw, H.; Armantrout, G.

1995-01-01

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

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. Copyright 2010 Elsevier Inc. All rights reserved.

Immobilization Patterns and Dynamics of Acetate-Utilizing Methanogens Immobilized in Sterile Granular Sludge in Upflow Anaerobic Sludge Blanket Reactors

Science.gov (United States)

Schmidt, Jens Ejbye; Ahring, Birgitte Kjær

1999-01-01

Sterile granular sludge was inoculated with either Methanosarcina mazeii S-6, Methanosaeta concilii GP-6, or both species in acetate-fed 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 M. mazeii S-6. The highest effluent concentration of acetate was observed in the reactor with only M. 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 (Ks and μmax) of immobilized M. concilii GP-6 or M. mazeii S-6 compared with suspended cultures, indicating that immobilization does not affect the growth kinetics of these methanogens. An enzyme-linked immunosorbent assay using polyclonal antibodies against either M. concilii GP-6 or M. mazeii S-6 showed significant variations in the two methanogenic populations in the different reactors. Polyclonal antibodies were further used to study the spatial distribution of the two methanogens. M. concilii GP-6 was immobilized only on existing support material without any specific pattern. M. mazeii S-6, however, showed a different immobilization pattern: large clumps were formed when the concentration of acetate was high, but where the acetate concentration was low this strain was immobilized on support material as single cells or small clumps. The data clearly show that the two aceticlastic methanogens immobilize differently in UASB systems, depending on the conditions found throughout the UASB reactor. PMID:10049862

Biodegradation of chlorobenzene using immobilized crude extracts ...

African Journals Online (AJOL)

SERVER

2007-10-04

Oct 4, 2007 ... immobilized crude extracts were reused for all other experiments and found that immobilization .... India which are of analytical reagent grade. .... 9. 60. 3. 1. Figure 3. Degradation of chlorobenzene by immobilized crude.

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

Directory of Open Access Journals (Sweden)

Azami M. S.

2016-01-01

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

Microbial interspecies electron transfer via electric currents through conductive minerals

Science.gov (United States)

Kato, Souichiro; Hashimoto, Kazuhito; Watanabe, Kazuya

2012-01-01

In anaerobic biota, reducing equivalents (electrons) are transferred between different species of microbes [interspecies electron transfer (IET)], establishing the basis of cooperative behaviors and community functions. IET mechanisms described so far are based on diffusion of redox chemical species and/or direct contact in cell aggregates. Here, we show another possibility that IET also occurs via electric currents through natural conductive minerals. Our investigation revealed that electrically conductive magnetite nanoparticles facilitated IET from Geobacter sulfurreducens to Thiobacillus denitrificans, accomplishing acetate oxidation coupled to nitrate reduction. This two-species cooperative catabolism also occurred, albeit one order of magnitude slower, in the presence of Fe ions that worked as diffusive redox species. Semiconductive and insulating iron-oxide nanoparticles did not accelerate the cooperative catabolism. Our results suggest that microbes use conductive mineral particles as conduits of electrons, resulting in efficient IET and cooperative catabolism. Furthermore, such natural mineral conduits are considered to provide ecological advantages for users, because their investments in IET can be reduced. Given that conductive minerals are ubiquitously and abundantly present in nature, electric interactions between microbes and conductive minerals may contribute greatly to the coupling of biogeochemical reactions. PMID:22665802

Compared microbiology of granular sludge under autotrophic, mixotrophic and heterotrophic denitrification conditions.

Science.gov (United States)

Fernández, N; Sierra-Alvarez, R; Amils, R; Field, J A; Sanz, J L

2009-01-01

Water contamination by nitrate is a wideworld extended phenomena. Biological autotrophic denitrification has a real potential to face this problem and presents less drawbacks than the most extended heterotrophic denitrification. Three bench-scale UASB reactors were operated under autotrophic (R1, H2S as electron donor), mixotrophic (R2, H2S plus p-cresol as electron donors) and heterotrophic (R3, p-cresol as electron donor) conditions using nitrate as terminal electron acceptor. 16S rDNA genetic libraries were built up to compare their microbial biodiversity. Six different bacteria phyla and three archaeal classes were observed. Proteobacteria was the main phyla in all reactors standing out the presence of denitrifiers. Microorganisms similar to Thiobacillus denitrificans and Acidovorax sp. performed the autotrophic denitification. These OTUs were displaced by chemoheterotrophic denitrifiers, especially by Limnobacter-like and Ottowia-like OTUs. Other phyla were Bacteroidetes, Chloroflexi, Firmicutes and Actinobacteria that--as well as Archaea members--were implicated in the degradation of organic matter, as substrate added as coming from endogenous sludge decay under autotrophic conditions. Archaea diversity remained low in all the reactors being Methanosaeta concilii the most abundant one.

Design-Only Conceptual Design Report: Plutonium Immobilization Plant

International Nuclear Information System (INIS)

DiSabatino, A.; Loftus, D.

1999-01-01

This design-only conceptual design report was prepared to support a funding request by the Department of Energy Office of Fissile Materials Disposition for engineering and design of the Plutonium Immobilization Plant, which will be used to immobilize up to 50 tonnes of surplus plutonium. The siting for the Plutonium Immobilization Plant will be determined pursuant to the site-specific Surplus Plutonium Disposition Environmental Impact Statement in a Plutonium Deposition Record of Decision in early 1999. This document reflects a new facility using the preferred technology (ceramic immobilization using the can-in-canister approach) and the preferred site (at Savannah River). The Plutonium Immobilization Plant accepts plutonium from pit conversion and from non-pit sources and, through a ceramic immobilization process, converts the plutonium into mineral-like forms that are subsequently encapsulated within a large canister of high-level waste glass. The final immobilized product must make the plutonium as inherently unattractive and inaccessible for use in nuclear weapons as the plutonium in spent fuel from commercial reactors and must be suitable for geologic disposal. Plutonium immobilization at the Savannah River Site uses: (1) A new building, the Plutonium Immobilization Plant, which will convert non-pit surplus plutonium to an oxide form suitable for the immobilization process, immobilize plutonium in a titanate-based ceramic form, place cans of the plutonium-ceramic forms into magazines, and load the magazines into a canister; (2) The existing Defense Waste Processing Facility for the pouring of high-level waste glass into the canisters; and (3) The Actinide Packaging and Storage Facility to receive and store feed materials. The Plutonium Immobilization Plant uses existing Savannah River Site infra-structure for analytical laboratory services, waste handling, fire protection, training, and other support utilities and services. The Plutonium Immobilization Plant

Management of immobilization and its complication for elderly.

Science.gov (United States)

Laksmi, Purwita W; Harimurti, Kuntjoro; Setiati, Siti; Soejono, Czeresna H; Aries, Wanarani; Roosheroe, Arya Govinda

2008-10-01

Increased life expectancy have an effect on the rising percentage of elderly population in Indonesia and health problem associated with the elderly, particularly immobilization. Immobilization may cause various complications, especially when it has been overlooked without any appropriate and proper medical care in keeping with the procedures. High incidence of immobilization in elderly and the life-threatening complication call for an agreement on management of immobilization and its complication. Management of immobilization needs interdisciplinary team-work cooperation, the patients and their family. The management may be commenced through a complete geriatric review, formulating functional goals and constructing therapeutic plan. Various medical conditions and external factors that may act as risk factors of immobilization as well as drugs intake that may exaggerate the immobilization should be evaluated and optimally managed. Any complication due to immobilization and other concomitant disease/condition should be recognized and managed comprehensively in order to reduce morbidity and mortality. Management of immobilization and its complications include pharmacological and non-pharmacological treatment, i.e. various mobility exercises, utilization of ambulatory device and supporting appliance for assisting patients in stand-up position, as well as the management of urinary voiding and defecation.

Excess Weapons Plutonium Immobilization in Russia

International Nuclear Information System (INIS)

Jardine, L.; Borisov, G.B.

2000-01-01

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 and 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 and 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

Radiation immobilization of catalase and its application

International Nuclear Information System (INIS)

Wang Guanghui; Ha Hongfei; Wang Xia; Wu Jilan

1988-01-01

Catalase was immobilized by a chemical method on porous polyacrylamide particles produced by radiation polymerization of acrylamide monomer at low temperature (-78 0 C). Activity of immobilized catalase was enhanced distinctly by joining a chemical arm to the support. The method of recovery of catalase activity on immobilized polymer was found by soaking it in certain buffer. The treatment of H 2 O 2 both in aqueous solution and alcoholic solution by using the immobilized catalase was performed. (author)

Radioactive seed immobilization techniques for interstitial brachytherapy

International Nuclear Information System (INIS)

Yan, K.; Podder, T.; Buzurovic, I.; Hu, Y.; Dicker, A.; Valicenti, R.; Yu, Y.; Messing, E.; Rubens, D.; Sarkar, N.; Ng, W.

2008-01-01

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.)

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.

Aplicação de técnicas eletroquímicas no estudo da dissolução oxidativa da covelita (CuS por Thiobacillus ferrooxidans Electrochemical techniques applied to study the oxidative dissolution of the covellite: CuS by Thiobacillus ferrooxidans

Directory of Open Access Journals (Sweden)

Christiane Medina Teixeira

2002-02-01

Full Text Available Among the copper sulphides, chalcopyrite (CuFeS2, covellite (CuS and chalcocite (Cu2S are the most important source of minerals for copper mining industry. The acknowledge of behaviour of these sulphides related with bacterial leaching process are essential for optimization procedures. Despite of its importance, covellite has not deserved much interest of researchers regarding this matter. In this work it was studied the oxidation of covellite by the chemolithotrophic bacterium Thiobacillus ferrooxidans by using electrochemical techniques, such as open circuit potentials with the time and cyclic voltammetry. The experiments were carried out in acid medium (pH 1.8, containing or not Fe2+ as additional energy source, and in different periods of incubation; chemical controls were run in parallel. The results showed that a sulphur layer is formed spontaneously due the acid attack, covering the sulphide in the initial phase of incubation, blocking the sulphide oxidation. However, the bacterium was capable to oxidize this sulphur layer. In the presence of Fe2+ as supplemental energy source, the corrosion process was facilitated, because ocurred an indirect oxidation of covellite by Fe3+, which was produced by T. ferrooxidans oxidation of the Fe2+ added in the medium.

Immobilization and characterization of inulinase from Ulocladium

Indian Academy of Sciences (India)

Ulocladium atrum inulinase was immobilized on different composite membranes composed of chitosan/nonwoven fabrics. Km values of free and immobilized U. atrum inulinase on different composite membranes were calculated. The enzyme had optimum pH at 5.6 for free and immobilized U. atrum inulinase on polyester ...

Immobilization of Mortierella vinacea cells by radiation polymerization

International Nuclear Information System (INIS)

Kumakura, M.; Kaetsu, I.

1983-01-01

Immobilization of Mortierella vinacea cells, which contain active α-galactosidase, by radiation polymerization at low temperatures was studied. The durability of the enzymatic activity of the immobilized cells obtained with hydrophilic monomers was affected by the concentrations of the cells and monomer in which optimum conditions were observed. The enzymatic activity of the immobilized cells obtained with hydrophilic monomers was compared to that of hydrophobic monomers. Michaelis constants of the immobilized cells varied with monomer concentration. The effect of addition of porous solid substances on the immobilization of the cells was studied

Treatment and immobilization of intermediate level radioactive wastes

International Nuclear Information System (INIS)

Lerch, R.E.; Greenhalgh, W.O.; Partridge, J.A.; Richardson, G.L.

1977-01-01

This paper discusses a new program underway to develop and demonstrate treatment and immobilization technologies for intermediate level wastes (ILW) generated in the nuclear fuel cycle. Initial work has defined the sources, quantities and types of wastes which comprise ILW. Laboratory studies are underway to define treatment technologies for liquid ILW which contains volatile contaminants and to define immobilization parameters for the residues resulting from treatment of ILW. Immobilization agents initially being evaluated for the various residues include cement, urea-formaldehyde, and bitumen although other immobilization agents will be studied. The program also includes development of acceptable test procedures for the final immobilized products as well as development of proposed criteria for storage, transportation, and disposal of the immobilized ILW. 20 figures, 10 tables

Lipase immobilization and production of fatty acid methyl esters from canola oil using immobilized lipase

International Nuclear Information System (INIS)

Yuecel, Yasin; Demir, Cevdet; Dizge, Nadir; Keskinler, Buelent

2011-01-01

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 o C 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%.

Reversible thermal denaturation of immobilized rhodanese

International Nuclear Information System (INIS)

Horowitz, P.; Bowman, S.

1987-01-01

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 [ 35 S]SO 3 (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

Properties of immobilized papain by radiation polymerization

International Nuclear Information System (INIS)

Kumakura, Minoru; Kaetsu, Isao

1984-01-01

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)

Hydrogen sulfide oxidation in novel Horizontal-Flow Biofilm Reactors dominated by an Acidithiobacillus and a Thiobacillus species.

Science.gov (United States)

Gerrity, S; Kennelly, C; Clifford, E; Collins, G

2016-09-01

Hydrogen Sulfide (H2S) is an odourous, highly toxic gas commonly encountered in various commercial and municipal sectors. Three novel, laboratory-scale, Horizontal-Flow Biofilm Reactors (HFBRs) were tested for the removal of H2S gas from air streams over a 178-day trial at 10°C. Removal rates of up to 15.1 g [H2S] m(-3) h(-1) were achieved, demonstrating the HFBRs as a feasible technology for the treatment of H2S-contaminated airstreams at low temperatures. Bio-oxidation of H2S in the reactors led to the production of H(+) and sulfate (SO(2-)4) ions, resulting in the acidification of the liquid phase. Reduced removal efficiency was observed at loading rates of 15.1 g [H2S] m(-3) h(-1). NaHCO3 addition to the liquid nutrient feed (synthetic wastewater (SWW)) resulted in improved H2S removal. Bacterial diversity, which was investigated by sequencing and fingerprinting 16S rRNA genes, was low, likely due to the harsh conditions prevailing in the systems. The HFBRs were dominated by two species from the genus Acidithiobacillus and Thiobacillus. Nonetheless, there were significant differences in microbial community structure between distinct HFBR zones due to the influence of alkalinity, pH and SO4 concentrations. Despite the low temperature, this study indicates HFBRs have an excellent potential to biologically treat H2S-contaminated airstreams.

Preparation of Laccase Immobilized Cryogels and Usage for Decolorization

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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.

Novel immobilization process of a thermophilic catalase: efficient purification by heat treatment and subsequent immobilization at high temperature.

Science.gov (United States)

Xu, Juan; Luo, Hui; López, Claudia; Xiao, Jing; Chang, Yanhong

2015-10-01

The main goal of the present work is to investigate a novel process of purification and immobilization of a thermophilic catalase at high temperatures. The catalase, originated from Bacillus sp., was overexpressed in a recombinant Escherichia coli BL21(DE3)/pET28-CATHis and efficiently purified by heat treatment, achieving a threefold purification. The purified catalase was then immobilized onto an epoxy support at different temperatures (25, 40, and 55 °C). The immobilizate obtained at higher temperatures reached its maximum activity in a shorter time than that obtained at lower temperatures. Furthermore, immobilization at higher temperatures required a lower ionic strength than immobilization at lower temperatures. The characteristics of immobilized enzymes prepared at different temperatures were investigated. The high-temperature immobilizate (55 °C) showed the highest thermal stability, followed by the 40 °C immobilizate. And the high-temperature immobilizate (55 °C) had slightly higher operational stability than the 25 °C immobilizate. All of the immobilized catalase preparations showed higher stability than the free enzyme at alkaline pH 10.0, while the alkali resistance of the 25 °C immobilizate was slightly better than that of the 40 and 55 °C immobilizates.

Glucose Oxidase Immobilization on TMAH-Modified Bentonite

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Ruth Chrisnasari

2015-03-01

Full Text Available The influence of bentonite modification by tetramethyl ammonium hydroxide (TMAH on its capability to immobilize glucose oxidase (GOX was studied. Modification of bentonite was conducted by the adding of 0-5% (v/v TMAH. The observed results show that the different concentrations of TMAH affect the percentage of immobilized enzyme. The results of this study show that the best concentration of TMAH is 5% (v/v which can immobilize up to 84.71% of GOX. X-ray diffraction (XRD and Fourier Transforms Infrared Spectroscopy (FTIR studies have been carried out to observe the structural changes in bentonite due to TMAH modification. The obtained immobilized GOX show the optimum catalytic activity on reaction temperature of 40-50 °C and pH of 7. The immobilized GOX kinetics at the optimum conditions determined the Km and Vmax value to be 4.96x10-2 mM and 4.99x10-3 mM.min-1 respectively. In addition, the immobilized GOX on TMAH-modified bentonite is stable enough so it could be re-used six times before its activity decreased by 39.44%.

Biotechnological production of vanillin using immobilized enzymes.

Science.gov (United States)

Furuya, Toshiki; Kuroiwa, Mari; Kino, Kuniki

2017-02-10

Vanillin is an important and popular plant flavor, but the amount of this compound available from plant sources is very limited. Biotechnological methods have high potential for vanillin production as an alternative to extraction from plant sources. Here, we report a new approach using immobilized enzymes for the production of vanillin. The recently discovered oxygenase Cso2 has coenzyme-independent catalytic activity for the conversion of isoeugenol and 4-vinylguaiacol to vanillin. Immobilization of Cso2 on Sepabeads EC-EA anion-exchange carrier conferred enhanced operational stability enabling repetitive use. This immobilized Cso2 catalyst allowed 6.8mg yield of vanillin from isoeugenol through ten reaction cycles at a 1mL scale. The coenzyme-independent decarboxylase Fdc, which has catalytic activity for the conversion of ferulic acid to 4-vinylguaiacol, was also immobilized on Sepabeads EC-EA. We demonstrated that the immobilized Fdc and Cso2 enabled the cascade synthesis of vanillin from ferulic acid via 4-vinylguaiacol with repetitive use of the catalysts. This study is the first example of biotechnological production of vanillin using immobilized enzymes, a process that provides new possibilities for vanillin production. Copyright © 2016 Elsevier B.V. All rights reserved.

Antimicrobial activity of immobilized lactoferrin and lactoferricin.

Science.gov (United States)

Chen, Renxun; Cole, Nerida; Dutta, Debarun; Kumar, Naresh; Willcox, Mark D P

2017-11-01

Lactoferrin and lactoferricin were immobilized on glass surfaces via two linkers, 4-azidobenzoic acid (ABA) or 4-fluoro-3-nitrophenyl azide (FNA). The resulting surfaces were characterized by X-ray photoelectron spectroscopy (XPS) and contact angle measurements. The antimicrobial activity of the surfaces was determined using Pseudomonas aeruginosa and Staphylococcus aureus strains by fluorescence microscopy. Lactoferrin and lactoferricin immobilization was confirmed by XPS showing significant increases (p lactoferricin immobilized on glass significantly (p lactoferricin were successfully immobilized on glass surfaces and showed promising antimicrobial activity against pathogenic bacteria. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2612-2617, 2017. © 2016 Wiley Periodicals, Inc.

Immobilization thresholds of electrofishing relative to fish size

Science.gov (United States)

Dolan, C.R.; Miranda, L.E.

2003-01-01

Fish size and electrical waveforms have frequently been associated with variation in electrofishing effectiveness. Under controlled laboratory conditions, we measured the electrical power required by five electrical waveforms to immobilize eight fish species of diverse sizes and shapes. Fish size was indexed by total body length, surface area, volume, and weight; shape was indexed by the ratio of body length to body depth. Our objectives were to identify immobilization thresholds, elucidate the descriptors of fish size that were best associated with those immobilization thresholds, and determine whether the vulnerability of a species relative to other species remained constant across electrical treatments. The results confirmed that fish size is a key variable controlling the immobilization threshold and further suggested that the size descriptor best related to immobilization is fish volume. The peak power needed to immobilize fish decreased rapidly with increasing fish volume in small fish but decreased slowly for fish larger than 75-100 cm 3. Furthermore, when we controlled for size and shape, different waveforms did not favor particular species, possibly because of the overwhelming effect of body size. Many of the immobilization inconsistencies previously attributed to species might simply represent the effect of disparities in body size.

Immobilization of yeast cells by radiation-induced polymerization

International Nuclear Information System (INIS)

Fujimura, T.; Kaetsu, I.

1982-01-01

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.)

Ceramic membrane microfilter as an immobilized enzyme reactor.

Science.gov (United States)

Harrington, T J; Gainer, J L; Kirwan, D J

1992-10-01

This study investigated the use of a ceramic microfilter as an immobilized enzyme reactor. In this type of reactor, the substrate solution permeates the ceramic membrane and reacts with an enzyme that has been immobilized within its porous interior. The objective of this study was to examine the effect of permeation rate on the observed kinetic parameters for the immobilized enzyme in order to assess possible mass transfer influences or shear effects. Kinetic parameters were found to be independent of flow rate for immobilized penicillinase and lactate dehydrogenase. Therefore, neither mass transfer nor shear effects were observed for enzymes immobilized within the ceramic membrane. Both the residence time and the conversion in the microfilter reactor could be controlled simply by regulating the transmembrane pressure drop. This study suggests that a ceramic microfilter reactor can be a desirable alternative to a packed bed of porous particles, especially when an immobilized enzyme has high activity and a low Michaelis constant.

Immobilization of Isolated Lipase From Moldy Copra (Aspergillus Oryzae

Directory of Open Access Journals (Sweden)

Seniwati Dali

2011-01-01

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

Immobile Complex Verbs in Germanic

DEFF Research Database (Denmark)

Vikner, Sten

2005-01-01

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...... frequent type with only one prefix-like part (e.g., German bauchreden/Dutch buikspreken ‘to ventriloquize'). This analysis will try to account not only for the data discussed in Haider (1993) and Koopman (1995) but also for the following: - why immobile verbs include verbs with only one prefix-like part...... are immobile, - why such verbs are not found in Germanic VO-languages such as English and Scandinavian....

Plutonium Immobilization Can Loading Equipment Review

International Nuclear Information System (INIS)

Kriikku, E.; Ward, C.; Stokes, M.; Randall, B.; Steed, J.; Jones, R.; Hamilton, L.

1998-05-01

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

Characterization of immobilized post-carbohydrate meal salivary α ...

African Journals Online (AJOL)

The effect of experimental parameters like pH, temperature and substrate concentration on the activity of the immobilized post-carbohydrate meal salivary ... of immobilized post-carbohydrate meal salivary α-amylase in this study show that immobilization had no significant effect on the enzyme and compared to kinetic ...

Immobilization of thorium over fibroin by polyacrylonitrile (PAN)

International Nuclear Information System (INIS)

Aslani, M.A.A.; Akyil, S.; Eral, M.

1997-01-01

This report describes a process for immobilization of thorium over fibroin, which was used as a bio-adsorbant, by polyacrylonitrile. The amounts of thorium in aqueous solutions which may be leached in various aqueous ambients were detected by a spectrophotometer. The results show that polyacrylonitrile processes are feasible to immobilize spent fibroins. The leachability of the materials immobilized with polyacrylonitrile can meet the requirements of storage and final disposal. The leachability of thorium ions from immobilized spent fibroin was rather low for 8 months

Charge and softness of the outer part of the cell wall of Thiobacillus ferrooxidans in the low ionic strength medium

Directory of Open Access Journals (Sweden)

Škvarla Jiří

2002-03-01

Full Text Available The surface charge and surface potential are parameters influencing the microbial adhesion phenomenon through the electrostatic interaction between bacteria and substrates. The Smoluchowski equation, originally developed for estimating the above parameters from the experimentally accessible electrophoretic mobility of rigid colloid particles, is however inapplicable to the elastic bacterial cells. The problem is that the outer cell wall of bacteria is a layer with a complex polyelectrolyte structure. In this article, the OhshimaLs model of the gsofth particle is applied to describe the surface electrostatics of Thiobacillus ferrooxidans cells by measuring their electrophoretic mobility in distilled water as a function of a (low ionic strength and pH. In this model, the rigid core is considered to be covered with a charged ion-penetrable layer of polyelectrolytes. Two model parameters have been determined by the curve fitting at pH from 3.2 to 5.8, namely the number density of the dissociated groups N and the softness parameter 1/ƒÉ of the polyelectrolyte layer of the bacterium. A disagreement of the best fit parameters (evaluated by the correlation coefficient with the analogous parameters determined for other colloids (including bacterial cells in aqueous solutions of a high ionic strength is discussed.

Metabolic alkalosis during immobilization in monkeys (M. nemestrina)

Science.gov (United States)

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

1983-01-01

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

Immobilization of ammonia-oxidizing bacteria by polyvinyl alcohol and sodium alginate.

Science.gov (United States)

Dong, Yuwei; Zhang, Yanqiu; Tu, Baojun

Ammonia-oxidizing bacteria were immobilized by polyvinyl alcohol (PVA) and sodium alginate. The immobilization conditions and ammonia oxidation ability of the immobilized bacteria were investigated. The following immobilization conditions were observed to be optimal: PVA, 12%; sodium alginate, 1.1%; calcium chloride, 1.0%; inoculum concentration, 1.3 immobilized balls/mL of immobilized medium; pH, 10; and temperature, 30°C. The immobilized ammonia-oxidizing bacteria exhibited strong ammonia oxidation ability even after being recycled four times. The ammonia nitrogen removal rate of the immobilized ammonia-oxidizing bacteria reached 90.30% under the optimal immobilization conditions. When compared with ammonia-oxidizing bacteria immobilized by sodium alginate alone, the bacteria immobilized by PVA and sodium alginate were superior with respect to pH resistance, the number of reuses, material cost, heat resistance, and ammonia oxidation ability. Copyright © 2017 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

Radiation technology for immobilization of bioactive materials

International Nuclear Information System (INIS)

1988-12-01

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

Thermal stability of the immobilized fructosyltransferase from Rhodotorula sp

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E Aguiar-Oliveira

2011-09-01

Full Text Available The thermal stability of the extracellular fructosyltransferase (FTase from Rhodotorula sp., recovered from cultivation medium by ethanol precipitation and immobilized onto niobium ore, was studied by Arrhenius plot, half - life profile, half - inactivation temperature (T50 and thermodynamic parameters. The Arrhenius plot showed two different behaviors with different deactivation energies (Ead only after immobilization, the transition occurring in the temperature interval between 51 and 52ºC. T50 for the free enzyme was estimated to be around 62ºC and, after immobilization, 66ºC. After 15 minutes at 52ºC, it was also possible to observe enzymatic activation for both the free and immobilized forms, but greater activation was achieved at pH 4.5 with the immobilized enzyme. Between 47 - 51ºC the immobilized enzyme was more stable than the free enzyme, with pH 6.0 being the more stable condition for the immobilized enzyme. However, above 52ºC the free form was more stable.

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.

Preparation and characterization of immobilized lipase on magnetic hydrophobic microspheres

DEFF Research Database (Denmark)

Guo, Zheng; Bai, Shu; Sun, Yan

2003-01-01

H for the immobilized CCL were determined. Activity amelioration of the immobilized CCL for the hydrolysis of olive oil was observed, indicating an interfacial activation of the enzyme after immobilization. Moreover, the immobilized CCL showed enhanced thermal stability and good durability in the repeated use after...

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…

Immobilization of Isolated Lipase From Moldy Copra (Aspergillus Oryzae)

OpenAIRE

Dali, Seniwati; Patong, A. B. D. Rauf; Jalaluddin, M. Noor; Pirman; Hamzah, Baharuddin

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 ...

Polymer-assisted iron oxide magnetic nanoparticle immobilized keratinase

Energy Technology Data Exchange (ETDEWEB)

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

2009-06-03

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

Polymer-assisted iron oxide magnetic nanoparticle immobilized keratinase

International Nuclear Information System (INIS)

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

2009-01-01

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

Polymer-assisted iron oxide magnetic nanoparticle immobilized keratinase

Science.gov (United States)

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

2009-06-01

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

Biosorption of americium-241 by immobilized Rhizopus arrihizus

International Nuclear Information System (INIS)

Liao Jiali; Yang Yuanyou; Luo Shunzhong; Liu Ning; Jin Jiannan; Zhang Taiming; Zhao Pengji

2004-01-01

Rhizopus arrihizus (R. arrihizus), a fungus, which in previous experiments had shown encouraging ability to remove 241 Am from solutions, was immobilized by calcium alginate and other reagents. The various factors affecting 241 Am biosorption by the immobilized R. arrihizus were investigated. The results showed that not only can immobilized R. arrihizus adsorb 241 Am as efficiently as free R. arrihizus, but that also can be used repeatedly or continuously. The biosorption equilibrium was achieved within 2 h, and more than 94% of 241 Am was removed from 241 Am solutions of 1.08 MBq/l by immobilized R. arrihizu in the pH range 1-7. Temperature did not affect the adsorption on immobilized R. arrihizus in the range 15-45 deg. C. After repeated adsorption for 8 times, the immobilized R. arrihizus still adsorbed more than 97% of 241 Am. At this time, the total adsorption of 241 Am was more than 88.6 KBq/g, and had not yet reached saturation. Ninety-five percent of the adsorbed 241 Am was desorbed by saturated EDTA solution and 98% by 2 mol/l HNO 3

Enzyme Engineering for In Situ Immobilization.

Science.gov (United States)

Rehm, Fabian B H; Chen, Shuxiong; Rehm, Bernd H A

2016-10-14

Enzymes are used as biocatalysts in a vast range of industrial applications. Immobilization of enzymes to solid supports or their self-assembly into insoluble particles enhances their applicability by strongly improving properties such as stability in changing environments, re-usability and applicability in continuous biocatalytic processes. The possibility of co-immobilizing various functionally related enzymes involved in multistep synthesis, conversion or degradation reactions enables the design of multifunctional biocatalyst with enhanced performance compared to their soluble counterparts. This review provides a brief overview of up-to-date in vitro immobilization strategies while focusing on recent advances in enzyme engineering towards in situ self-assembly into insoluble particles. In situ self-assembly approaches include the bioengineering of bacteria to abundantly form enzymatically active inclusion bodies such as enzyme inclusions or enzyme-coated polyhydroxyalkanoate granules. These one-step production strategies for immobilized enzymes avoid prefabrication of the carrier as well as chemical cross-linking or attachment to a support material while the controlled oriented display strongly enhances the fraction of accessible catalytic sites and hence functional enzymes.

Halloysite Clay Nanotubes for Enzyme Immobilization.

Science.gov (United States)

Tully, Joshua; Yendluri, Raghuvara; Lvov, Yuri

2016-02-08

Halloysite clay is an aluminosilicate nanotube formed by rolling flat sheets of kaolinite clay. They have a 15 nm lumen, 50-70 nm external diameter, length of 0.5-1 μm, and different inside/outside chemistry. Due to these nanoscale properties, they are used for loading, storage, and controlled release of active chemical agents, including anticorrosions, biocides, and drugs. We studied the immobilization in halloysite of laccase, glucose oxidase, and lipase. Overall, negatively charged proteins taken above their isoelectric points were mostly loaded into the positively charged tube's lumen. Typical tube loading with proteins was 6-7 wt % from which one-third was released in 5-10 h and the other two-thirds remained, providing enhanced biocatalysis in nanoconfined conditions. Immobilized lipase showed enhanced stability at acidic pH, and the optimum pH shifted to more alkaline pH. Immobilized laccase was more stable with respect to time, and immobilized glucose oxidase showed retention of enzymatic activity up to 70 °C, whereas the native sample was inactive.

Characterization of the bacterial community in a biotrickling filter treating high loads of H(2)S by molecular biology tools.

Science.gov (United States)

Maestre, Juan P; Rovira, Roger; Gamisans, Xavier; Kinney, Kerry A; Kirisits, Mary Jo; Lafuente, Javier; Gabriel, David

2009-01-01

The diversity and spatial distribution of bacteria in a lab-scale biotrickling filter treating high loads of hydrogen sulfide (H(2)S) were investigated. Diversity and community structure were studied by terminal-restriction fragment length polymorphism (T-RFLP). A 16S rRNA gene clone library was established. Near Full-length 16S rRNA gene sequences were obtained, and clones were clustered into 24 operational taxonomic units (OTUs). Nearly 74% and 26% of the clones were affiliated with the phyla Proteobacteria and Bacteroidetes, respectively. Beta-, epsilon- and gamma-proteobacteria accounted for 15, 9 and 48%, respectively. Around 45% of the sequences retrieved were affiliated to bacteria of the sulfur cycle including Thiothrix spp., Thiobacillus spp. and Sulfurimonas denitrificans. Sequences related to Thiothrix lacustris accounted for a 38%. Rarefaction curve demonstrated that clone library constructed can be sufficient to describe the vast majority of the bacterial diversity of this reactor operating under strict conditions (2,000 ppm(v) of H(2)S). A spatial distribution of bacteria was found along the length of the reactor by means of the T-RFLP technique. Although aerobic species were predominant along the reactor, facultative anaerobes had a major relative abundance in the inlet part of the reactor, where the sulfide to oxygen ratio is higher.

Disposition of surplus fissile materials via immobilization

International Nuclear Information System (INIS)

Gray, L.W.; Kan, T.; Sutcliffe, W.G.; McKibben, J.M.; Danker, W.

1995-01-01

In the Cold War aftermath, the US and Russia have agreed to large reductions in nuclear weapons. To aid in the selection of long-term management options, the USDOE has undertaken a multifaceted study to select options for storage and disposition of surplus plutonium (Pu). One disposition alternative being considered is immobilization. Immobilization is a process in which surplus Pu would be embedded in a suitable material to produce an appropriate form for ultimate disposal. To arrive at an appropriate form, we first reviewed published information on HLW immobilization technologies to identify forms to be prescreened. Surviving forms were screened using multi-attribute utility analysis to determine promising technologies for Pu immobilization. We further evaluated the most promising immobilization families to identify and seek solutions for chemical, chemical engineering, environmental, safety, and health problems; these problems remain to be solved before we can make technical decisions about the viability of using the forms for long-term disposition of Pu. All data, analyses, and reports are being provided to the DOE Office of Fissile Materials Disposition to support the Record of Decision that is anticipated in Summer of 1996

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......, but where the acetate concentration was low this strain was immobilized on support material as single cells or small clumps, The data clearly show that the two aceticlastic methanogens immobilize differently in UASB systems, depending on the conditions found throughout the UASB reactor....

Microbial control of hydrogen sulfide production

Energy Technology Data Exchange (ETDEWEB)

Montgomery, A.D.; Bhupathiraju, V.K.; Wofford, N.; McInerney, M.J. [Univ. of Oklahoma, Tulsa, OK (United States)] [and others

1995-12-31

A sulfide-resistant strain of Thiobacillus denitrificans, strain F, prevented the accumulation of sulfide by Desulfovibrio desulfuricans when both organisms were grown in liquid medium. The wild-type strain of T. denitrificans did not prevent the accumulation of sulfide produced by D. desulfuricans. Strain F also prevented the accumulation of sulfide by a mixed population of sulfate-reducing bacteria enriched from an oil field brine. Fermentation balances showed that strain F stoichiometrically oxidized the sulfide produced by D. desulfuricans and the oil field brine enrichment to sulfate. The ability of a strain F to control sulfide production in an experimental system of cores and formation water from the Redfield, Iowa, natural gas storage facility was also investigated. A stable, sulfide-producing biofilm was established in two separate core systems, one of which was inoculated with strain F while the other core system (control) was treated in an identical manner, but was not inoculated with strain F. When formation water with 10 mM acetate and 5 mM nitrate was injected into both core systems, the effluent sulfide concentrations in the control core system ranged from 200 to 460 {mu}M. In the test core system inoculated with strain F, the effluent sulfide concentrations were lower, ranging from 70 to 110 {mu}M. In order to determine whether strain F could control sulfide production under optimal conditions for sulfate-reducing bacteria, the electron donor was changed to lactate and inorganic nutrients (nitrogen and phosphate sources) were added to the formation water. When nutrient-supplemented formation water with 3.1 mM lactate and 10 mM nitrate was used, the effluent sulfide concentrations of the control core system initially increased to about 3,800 {mu}M, and then decreased to about 1,100 {mu}M after 5 weeks. However, in the test core system inoculated with strain F, the effluent sulfide concentrations were much lower, 160 to 330 {mu}M.

A field demonstration of the microbial treatment of sour produced water

Energy Technology Data Exchange (ETDEWEB)

Sublette, K.L. [Univ. of Tulsa, OK (United States); Morse, D.; Raterman, K. [Amoco Production Co., Tulsa, OK (United States)

1995-12-31

The potential for detoxification and deodorization of sulfide-laden water (sour water) by microbial treatment was evaluated at a petroleum production site under field conditions. A sulfide-tolerant strain of the chemautotroph and facultative anaerobe, Thiobacillus denitrificans, was introduced into an oil-skimming pit of the Amoco Production Company LACT 10 Unit of the Salt Creek Field, Wyoming. Field-produced water enters this pit from the oil/water separation treatment train at an average flowrate of 5,000 bbl/D (795 m{sup 3}/D) with a potential maximum of 98,000 bbl/D (15,580 m{sup 3}/D). Water conditions at the pit inlet are 4,800 mg/l TDS, 100 mg/l sulfide, pH 7.8, and 107{degrees}F. To this water an aqueous solution of ammonium nitrate and diphosphorous pentoxide was added to provide required nutrients for the bacteria. The first 20% of the pit was aerated to a maximum depth of 5 ft (1.5 m) to facilitate the aerobic oxidation of sulfide. No provisions for pH control or biomass recovery and recycle were made. Pilot operations were initiated in October 1992 with the inoculation of the 19,000 bbl (3,020 m{sup 3}) pit with 40 lb (18.1 kg) of dry weight biomass. After a brief acclimation period, a nearly constant mass flux of 175 lb/D (80 kg/D) sulfide was established to the pit. Bio-oxidation of sulfide to elemental sulfur and sulfate was immediate and complete. Subsequent pilot operations focused upon process optimization and process sensitivity to system upsets. The process appeared most sensitive to large variations in sulfide loading due to maximum water discharge events. However, recoveries from such events could be accomplished within hours. This paper details all pertinent aspects of pilot operation, performance, and economics. Based on this body of evidence, it is suggested that the oxidation of inorganic sulfides by T denitrificans represents a viable concept for the treatment of sour water coproduced with oil and gas.

Fouling-induced enzyme immobilization for membrane reactors

DEFF Research Database (Denmark)

Luo, Jianquan; Meyer, Anne S.; Jonsson, Gunnar Eigil

2013-01-01

A simple enzyme immobilization method accomplished by promoting membrane fouling formation is proposed. The immobilization method is based on adsorption and entrapment of the enzymes in/on the membrane. To evaluate the concept, two membrane orientations, skin layer facing feed (normal mode......, but the reverse mode allowed for higher enzyme loading and stability, and irreversible fouling (i.e. pore blocking) developed more readily in the support structure than in the skin layer. Compared with an enzymatic membrane reactor (EMR) with free enzymes, the novel EMR with enzymes immobilized in membrane......) and support layer facing feed (reverse mode), were used to immobilize alcohol dehydrogenase (ADH, EC 1.1.1.1) and glutamate dehydrogenase (GDH, EC 1.4.1.3), respectively. The nature of the fouling in each mode was determined by filtration fouling models. The permeate flux was larger in the normal mode...

Drug immobilization of walrus (Odobenus rosmarus)

Science.gov (United States)

DeMaster, D.P.; Faro, J.B.; Estes, J.A.; Taggart, James; Zabel, C.

1981-01-01

Five out of nine walrus (Odobenus rosmarus) were successfully immobilized at Round Island, Alaska, in May of 1978 by combinations of phencyclidine hydrochloride and acepromazine hydrochloride. A crossbow was an effective delivery technique. Walruses that had recently hauled out were more suitable for immobilization than well-rested animals. Care was taken to prevent walruses from overheating or suffocating.

b-GALACTOSIDASE IMMOBILIZATION ON CONTROLLED PORE SILICA

Directory of Open Access Journals (Sweden)

H. C. Trevisan

1997-12-01

Full Text Available The immobilization of b -galactosidase from Kluyveromyces fragilis on controlled pore silica was investigated. Immobilization was performed on amino silica activated with glutaraldehyde and the product was applied to the hydrolysis of lactose of whey. The behaviors of the soluble and immobilized enzyme were compared by using whey and a lactose solution as the substrate. With the aim of optimizing the method, parameters such as the amount of glutaraldehyde and the size of the particles were evaluated by comparing activities and stabilities on batch and continuously fluidized bed reactors

Immobilization of N-Heterocyclic Carbene Compounds: A Synthetic Perspective.

Science.gov (United States)

Zhong, Rui; Lindhorst, Anja C; Groche, Florian J; Kühn, Fritz E

2017-02-08

Over the course of the past 15 years the success story of N-heterocyclic carbene (NHC) compounds in organic, inorganic, and organometallic chemistry has been extended to another dimension. The immobilization of NHC compounds, undergoing continuous diversification, broadens their range of applications and leads to new solutions for challenges in catalytic and synthetic chemistry. This review intends to present a synthetic toolkit for the immobilization of NHC compounds, giving the reader an overview on synthetic techniques and strategies available in the literature. By individually summarizing and assessing the synthetic steps of the immobilization process, a comprehensive picture of the strategies and methodologies for the immobilization of NHC compounds is presented. Furthermore, the characterization of supported NHC compounds is discussed in detail in order to set up necessary criteria for an in-depth analysis of the immobilized derivatives. Finally, the catalytic applications of immobilized NHC compounds are briefly reviewed to illustrate the practical use of this technique for a broad variety of reaction types.

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, lactate release...

Dependence of protein binding capacity of dimethylamino-γ-butyric-acid (DMGABA)-immobilized porous membrane on composition of solvent used for DMGABA immobilization

International Nuclear Information System (INIS)

Iwanade, Akio; Umeno, Daisuke; Saito, Kyoichi; Sugo, Takanobu

2013-01-01

Dimethylamino-γ-butyric acid (DMGABA) as an ampholite was reacted with the epoxy group of the poly-glycidyl methacrylate chain grafted onto the pore surface of a porous hollow-fiber polyethylene membrane by radiation-induced graft polymerization. DMGABA was dissolved in a mixture of dioxane and water at various dioxane volume fractions, defined by dividing the dioxane volume by the total volume. The equilibrium binding capacity (EBC) of the DMGABA-immobilized porous hollow-fiber membrane for lysozyme was evaluated in the permeation mode. The EBC was varied from a 1/50-fold monolayer binding capacity to a 10-fold monolayer binding capacity by controlling the composition of the solvent used for DMGABA immobilization and the molar conversion of the epoxy group into the DMGABA group. - Highlights: ► A DMGABA membrane was immobilized by irradiation induced graft polymerization. ► The DMGABA was immobilized in a mixture of dioxane and water of various compositions. ► Lysozyme adsorptivity of DMGABA-immobilized membranes evaluated in the permeation mode. ► The composition of the DMGABA immobilized solvent can control adsorptivity

Preparation of immobilized growing cells and enzymatic hydrolysis of sawdust

International Nuclear Information System (INIS)

Kumakura, M.; Kaetsu, I.

1984-01-01

Trichoderma reesei cells were immobilized by radiation polymerization using porous materials such as non-woven material and sawdust, and the enzymatic hydrolysis of sawdust with the enzyme solution from the immobilized growing cells was studied. The filter paper activity, which shows the magnitude of cellulase production in the immobilized cells, was comparable with that in the intact cells. The filter paper activity was affected by addition concentration of monomer and porous materials. The cells in the immobilized cells grew to be adhered on the surface of the fibrous polymers. Sawdust, which was pretreated by irradiation technique, was effectively hydrolyzed with the enzyme solution resulting from the culture of the immobilized cells, in which the glucose yield increased increasing the culture time of the immobilized cells. (author)

Change in blood glucose level in rats after immobilization

Science.gov (United States)

Platonov, R. D.; Baskakova, G. M.; Chepurnov, S. A.

1981-01-01

Experiments were carried out on male white rats divided into four groups. In group one the blood glucose level was determined immediately after immobilization. In the other three groups, two hours following immobilization, the blood glucose level was determined every 20 minutes for 3 hours 40 minutes by the glucose oxidase method. Preliminary immobilization for 2 hours removed the increase in the blood glucose caused by the stress reaction. By the 2nd hour of immobilization in the presence of continuing stress, the blood glucose level stabilized and varied within 42 + or - 5.5 and 47 + or - 8.1 mg %. Within 2 hours after the immobilization, the differences in the blood glucose level of the rats from the control groups were statistically insignificant.

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.

Evaluation of fungal laccase immobilized on natural nanostructured bacterial cellulose

Directory of Open Access Journals (Sweden)

Lin eChen

2015-11-01

Full Text Available The aim of this work was to assess the possibility of using native bacterial nanocellulose (BC as a carrier for laccase immobilization. BC was synthesized by Gluconacetobacter xylinus, which was statically cultivated in a mannitol-based medium and was freeze-dried to form BC sponge after purification. For the first time, fungal laccase from Trametes versicolor was immobilized on the native nanofibril network-structured BC sponge through physical adsorption and cross-linking with glutaraldehyde. The properties including morphologic and structural features of the BC as well as the immobilized enzyme were thoroughly investigated. It was found that enzyme immobilized by cross-linking exhibited broader pH operation range of high catalytic activity as well as higher running stability compared to free and adsorbed enzyme. Using ABTS as substrate, the optimum pH value was 3.5 for the adsorption-immobilized laccase and 4.0 for the crosslinking-immobilized laccase. The immobilized enzyme retained 69% of the original activity after being recycled 7 times. Novel applications of the BC-immobilized enzyme tentatively include active packaging, construction of biosensors, and establishment of bioreactors.

Utility Estimation of the Manufactured Stereotactic Body Radiotherapy Immobilization

International Nuclear Information System (INIS)

Lee, Dong Hoon; Ahn, Jong Ho; Seo, Jeong Min; Shin, Eun Hyeak; Choi, Byeong Gi; Song, Gi Won

2011-01-01

Immobilizations used in order to maintain the reproducibility of a patient set-up and the stable posture for a long period are important more than anything else for the accurate treatment when the stereotactic body radiotherapy is underway. So the purpose of this study is to adapt the optimum immobilizations for the stereotactic body radiotherapy by comparing two commercial immobilizations with the self-manufactured immobilizations. Five people were selected for the experiment and three different immobilizations (A: Wing-board, B: BodyFix system, C: Arm up holder with vac-lock) were used to each target. After deciding on the target's most stable respiratory cycles, the targets were asked to wear a goggle monitor and maintain their respiration regularly for thirty minutes to obtain the respiratory signals. To analyze the respiratory signal, the standard deviation and the variation value of the peak value and the valley value of the respiratory signal were separated by time zone with the self-developed program at the hospital and each tie-downs were compared for the estimation by calculating a comparative index using the above. The stability of each immobilizations were measured in consideration of deviation changes studied in each respiratory time lapse. Comparative indexes of each immobilizations of each experimenter are shown to be A: 11.20, B: 4.87, C: 1.63 / A: 3.94, B: 0.67, C: 0.13 / A: 2.41, B: 0.29, C: 0.04 / A: 0.16, B: 0.19, C: 0.007 / A: 35.70, B: 2.37, C: 1.86. And when all five experimenters wore the immobilizations C, the test proved the most stable value while four people wearing A and one man wearing D expressed relatively the most unstable respiratory outcomes. The self-developed immobilizations, so called the arm up holder vac-lock for the stereotactic body radiotherapy is expected to improve the effect of the treatment by decreasing the intra-fraction organ motions because it keeps the respiration more stable than other two immobilizations

Purification-Free, Target-Selective Immobilization of a Protein from Cell Lysates.

Science.gov (United States)

Cha, Jaehyun; Kwon, Inchan

2018-02-27

Protein immobilization has been widely used for laboratory experiments and industrial processes. Preparation of a recombinant protein for immobilization usually requires laborious and expensive purification steps. Here, a novel purification-free, target-selective immobilization technique of a protein from cell lysates is reported. Purification steps are skipped by immobilizing a target protein containing a clickable non-natural amino acid (p-azidophenylalanine) in cell lysates onto alkyne-functionalized solid supports via bioorthogonal azide-alkyne cycloaddition. In order to achieve a target protein-selective immobilization, p-azidophenylalanine was introduced into an exogenous target protein, but not into endogenous non-target proteins using host cells with amber codon-free genomic DNAs. Immobilization of superfolder fluorescent protein (sfGFP) from cell lysates is as efficient as that of the purified sfGFP. Using two fluorescent proteins (sfGFP and mCherry), the authors also demonstrated that the target proteins are immobilized with a minimal immobilization of non-target proteins (target-selective immobilization). © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Cellulase immobilization on superparamagnetic nanoparticles for reuse in cellulosic biomass conversion

Directory of Open Access Journals (Sweden)

Fernando Segato

2016-07-01

Full Text Available Current cellulosic biomass hydrolysis is based on the one-time use of cellulases. Cellulases immobilized on magnetic nanocarriers offer the advantages of magnetic separation and repeated use for continuous hydrolysis. Most immobilization methods focus on only one type of cellulase. Here, we report co-immobilization of two types of cellulases, β-glucosidase A (BglA and cellobiohydrolase D (CelD, on sub-20 nm superparamagnetic nanoparticles. The nanoparticles demonstrated 100% immobilization efficiency for both BglA and CelD. The total enzyme activities of immobilized BglA and CelD were up to 67.1% and 41.5% of that of the free cellulases, respectively. The immobilized BglA and CelD each retained about 85% and 43% of the initial immobilized enzyme activities after being recycled 3 and 10 times, respectively. The effects of pH and temperature on the immobilized cellulases were also investigated. Co-immobilization of BglA and CelD on MNPs is a promising strategy to promote synergistic action of cellulases while lowering enzyme consumption.

Optimization of Adsorptive Immobilization of Alcohol Dehydrogenases

NARCIS (Netherlands)

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

2005-01-01

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

Fungal laccase: copper induction, semi-purification, immobilization ...

African Journals Online (AJOL)

Fungal laccase: copper induction, semi-purification, immobilization, phenolic effluent treatment and electrochemical measurement. ... In order to apply in an effluent treatment, laccase was immobilized on different vitroceramics supports, pyrolytic graphite and also on a carbon fiber electrode as biosensor. The maximum ...

Strong and Reversible Monovalent Supramolecular Protein Immobilization

NARCIS (Netherlands)

Young, Jacqui F.; Nguyen, Hoang D.; Yang, Lanti; Huskens, Jurriaan; Jonkheijm, Pascal; Brunsveld, Luc

2010-01-01

Proteins with an iron clasp: Site-selective incorporation of a ferrocene molecule into a protein allows for easy, strong, and reversible supramolecular protein immobilization through a selective monovalent interaction of the ferrocene with a cucurbit[7]uril immobilized on a gold surface. The

Role of Thiobacillus thioparus in the biodegradation of carbon disulfide in a biofilter packed with a recycled organic pelletized material.

Science.gov (United States)

Prenafeta-Boldú, Francesc X; Rojo, Naiara; Gallastegui, Gorka; Guivernau, Miriam; Viñas, Marc; Elías, Ana

2014-07-01

This study reports the biodegradation of carbon disulfide (CS2) in air biofilters packed with a pelletized mixture of composted manure and sawdust. Experiments were carried out in two lab-scale (1.2 L) biofiltration units. Biofilter B was seeded with activated sludge enriched previously on CS2-degrading biomass under batch conditions, while biofilter A was left as a negative inoculation control. This inoculum was characterized by an acidic pH and sulfate accumulation, and contained Achromobacter xylosoxidans as the main putative CS2 biodegrading bacterium. Biofilter operation start-up was unsuccessfully attempted under xerophilic conditions and significant CS2 elimination was only achieved in biofilter A upon the implementation of an intermittent irrigation regime. Sustained removal efficiencies of 90-100 % at an inlet load of up to 12 g CS2 m(-3) h(-1) were reached. The CS2 removal in this biofilter was linked to the presence of the chemolithoautotrophic bacterium Thiobacillus thioparus, known among the relatively small number of species with a reported capacity of growing on CS2 as the sole energy source. DGGE molecular profiles confirmed that this microbe had become dominant in biofilter A while it was not detected in samples from biofilter B. Conventional biofilters packed with inexpensive organic materials are suited for the treatment of low-strength CS2 polluted gases (IL biofiltration of recalcitrant compounds has been highlighted.

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.

Increase in stability of cellulase immobilized on functionalized magnetic nanospheres

International Nuclear Information System (INIS)

Zhang, Wenjuan; Qiu, Jianhui; Feng, Huixia; Zang, Limin; Sakai, Eiichi

2015-01-01

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

Ethanol fermentation by immobilized cells of Zymomonas mobilis

Energy Technology Data Exchange (ETDEWEB)

Grote, W.

1985-01-01

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

Characterization of a frozen shoulder model using immobilization in rats.

Science.gov (United States)

Kim, Du Hwan; Lee, Kil-Ho; Lho, Yun-Mee; Ha, Eunyoung; Hwang, Ilseon; Song, Kwang-Soon; Cho, Chul-Hyun

2016-12-08

The objective of this study was to investigate serial changes for histology of joint capsule and range of motion of the glenohumeral joint after immobilization in rats. We hypothesized that a rat shoulder contracture model using immobilization would be capable of producing effects on the glenohumeral joint similar to those seen in patients with frozen shoulder. Sixty-four Sprague-Dawley rats were randomly divided into one control group (n = 8) and seven immobilization groups (n = 8 per group) that were immobilized with molding plaster for 3 days, or for 1, 2, 3, 4, 5, or 6 weeks. At each time point, eight rats were euthanized for histologic evaluation of the axillary recess and for measurement of the abduction angle. Infiltration of inflammatory cells was found in the synovial tissue until 2 weeks after immobilization. However, inflammatory cells were diminished and fibrosis was dominantly observed in the synovium and subsynovial tissue 3 weeks after immobilization. From 1 week after immobilization, the abduction angle of all immobilization groups at each time point was significantly lower than that of the control group. Our study demonstrated that a rat frozen shoulder model using immobilization generates the pathophysiologic process of inflammation leading to fibrosis on the glenohumeral joint similar to that seen in patients with frozen shoulder. This model was attained within 3 weeks after immobilization. It may serve as a useful tool to investigate pathogenesis at the molecular level and identify potential target genes that are involved in the development of frozen shoulder.

A simple and robust approach to immobilization of antibody fragments.

Science.gov (United States)

Ikonomova, Svetlana P; He, Ziming; Karlsson, Amy J

2016-08-01

Antibody fragments, such as the single-chain variable fragment (scFv), have much potential in research and diagnostics because of their antigen-binding ability similar to a full-sized antibody and their ease of production in microorganisms. Some applications of antibody fragments require immobilization on a surface, and we have established a simple immobilization method that is based on the biotin-streptavidin interaction and does not require a separate purification step. We genetically fused two biotinylation tags-the biotin carboxyl carrier protein (BCCP) or the AviTag minimal sequence-to six different scFvs (scFv13R4, scFvD10, scFv26-10, scFv3, scFv5, and scFv12) for site-specific biotinylation in vivo by endogenous biotin ligases produced by Escherichia coli. The biotinylated scFvs were immobilized onto streptavidin-coated plates directly from cell lysates, and immobilization was detected through enzyme-linked immunosorbent assays. All scFvs fusions were successfully immobilized, and scFvs biotinylated via the BCCP tag tended to immobilize better than those biotinylated via the AviTag, even when biotinylation efficiency was improved with the biotin ligase BirA. The ability of immobilized scFvs to bind antigens was confirmed using scFv13R4 and scFvD10 with their respective targets β-galactosidase and bacteriophage lambda head protein D (gpD). The immobilized scFv13R4 bound to β-galactosidase at the same level for both biotinylation tags when the surface was saturated with the scFv, and immobilized scFvs retained their functionality for at least 100days after immobilization. The simplicity and robustness of our method make it a promising approach for future applications that require antibody fragment immobilization. Copyright © 2016 Elsevier B.V. All rights reserved.

Immobilized humic substances and immobilized aggregates of humic substances as sorbent for solid phase extraction.

Science.gov (United States)

Erny, Guillaume L; Gonçalves, Bruna M; Esteves, Valdemar I

2013-09-06

In this work, humic substances (HS) immobilized, as a thin layer or as aggregates, on silica gel were tested as material for solid phase extraction. Some triazines (simazine, atrazine, therbutylazine, atrazine-desethyl-desisopropyl-2-hydroxy, ametryn and terbutryn), have been selected as test analytes due to their environmental importance and to span a large range of solubility and octanol/water partition coefficient (logP). The sorbent was obtained immobilizing a thin layer of HS via physisorption on a pre-coated silica gel with a cationic polymer (polybrene). While the sorbent could be used as it is, it was demonstrated that additional HS could be immobilized, via weak interactions, to form stable humic aggregates. However, while a higher quantity of HS could be immobilized, no significant differences were observed in the sorption parameters. This sorbent have been tested for solid phase extraction to concentrate triazines from aqueous matrixes. The sorbent demonstrated performances equivalent to commercial alternatives as a concentration factor between 50 and 200, depending on the type of triazines, was obtained. Moreover the low cost and the high flow rate of sample through the column allowed using high quantity of sorbent. The analytical procedure was tested with different matrixes including tap water, river water and estuarine water. Copyright © 2013 Elsevier B.V. All rights reserved.

Immobilization of Peroxidase onto Magnetite Modified Polyaniline

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Eduardo Fernandes Barbosa

2012-01-01

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

Immobilization of cellulase using porous polymer matrix

International Nuclear Information System (INIS)

Kumakura, M.; Kaetsu, I.

1984-01-01

A new method is discussed for the immobilization of cellulase using porous polymer matrices, which were obtained by radiation polymerization of hydrophilic monomers. In this method, the immobilized enzyme matrix was prepared by enzyme absorbtion in the porous polymer matrix and drying treatment. The enzyme activity of the immobilized enzyme matrix varied with monomer concentration, cooling rate of the monomer solution, and hydrophilicity of the polymer matrix, takinn the change of the nature of the porous structure in the polymer matrix. The leakage of the enzymes from the polymer matrix was not observed in the repeated batch enzyme reactions

Distribution, ecology and inhibition of Thiobacillus ferrooxidans in relation to acid drainage from Witwatersrand gold mine dumps

International Nuclear Information System (INIS)

Whillier, P.A.

1987-03-01

The distribution and ecology of Thiobacillus ferrooxidans in gold mine dumps and possible means for its inhibition were investigated. A literature survey of the micro-ecology of mine waste dumps in various parts of the world was undertaken. A linear alkylbenzene sulphonate (LAS), NANSA 80/S, and a cetyl pyridinium chloride, Ceepryn, were tested as possible inhibitors for mine dump application. The LAS was rejected because it is poorly soluble in water and required higher concentrations than SLS for the inhibition of T.ferrooxidans. Ceepryn was an efficient inhibitor, but its efficiency was dramatically impeded in the presence of mine dump sand making it unsuitable for application on dumps. The SLS and LAS were tested against a mixed population of T.ferrooxidans from gold mine dumps and these bacteria were shown to be marginally more resistant to the inhibitors than the pure T.ferrooxidans culture. Sampling from mine dumps on the Witwatersrand suggested that the major T.ferrooxidans populations occurred in the moist sand of the drainage areas at the base of dumps, with few viable iron-oxidising bacteria located on the surfaces or in the centre of dumps. Sites of low moisture in dumps contained few or no viable bacteria. In the laboratory the bacterial viability decreased rapidly with loss of moisture from the sand. Moisture was shown to be important to bacterial activity and should be considered with respect to acid drainage control. Experimental sand columns showed that iron was leached with water from mine dump sand in the absence and presence of bacteria. In this study substrates, moisture, oxygen and carbon dioxide availability, ph, temperature, microorganisms and metal pollutants of uranium waste dumps are also covered

Immobilization: A Revolution in Traditional Brewing

Science.gov (United States)

Virkajärvi, Ilkka; Linko, Matti

In nature many micro-organisms tend to bind to solid surfaces. This tendency has long been utilized in a number of processes, for example in producing vinegar and acetic acid in bioreactors filled with wood shavings. Acetobacteria are attached to the surface of these shavings. In modern technical language: they are immobilized. Also yeast cells can be immobilized. In the brewing industry this has been the basis for maintaining efficient, continuous fermentation in bioreactors with very high yeast concentrations. The most dramatic change in brewing over recent years has been the replacement of traditional lagering of several weeks by a continuous process in which the residence time is only about 2h. Continuous primary fermentation is used on a commercial scale in New Zealand. In this process, instead of a carrier, yeast is retained in reactors by returning it partly after separation. In many pilot scale experiments the primary fermentation is shortened from about 1week to 1-2days using immobilized yeast reactors. When using certain genetically modified yeast strains no secondary fermentation is needed, and the total fermentation time in immobilized yeast reactors can therefore be shortened to only 2days.

Short-Term Upper Limb Immobilization Affects Action-Word Understanding

Science.gov (United States)

Bidet-Ildei, Christel; Meugnot, Aurore; Beauprez, Sophie-Anne; Gimenes, Manuel; Toussaint, Lucette

2017-01-01

The present study aimed to investigate whether well-established associations between action and language can be altered by short-term upper limb immobilization. The dominant arm of right-handed participants was immobilized for 24 hours with a rigid splint fixed on the hand and an immobilization vest restraining the shoulder, arm, and forearm. The…

Diesel oil removal by immobilized Pseudoxanthomonas sp. RN402.

Science.gov (United States)

Nopcharoenkul, Wannarak; Netsakulnee, Parichat; Pinyakong, Onruthai

2013-06-01

Pseudoxanthomonas sp. RN402 was capable of degrading diesel, crude oil, n-tetradecane and n-hexadecane. The RN402 cells were immobilized on the surface of high-density polyethylene plastic pellets at a maximum cell density of 10(8) most probable number (MPN) g(-1) of plastic pellets. The immobilized cells not only showed a higher efficacy of diesel oil removal than free cells but could also degrade higher concentrations of diesel oil. The rate of diesel oil removal by immobilized RN402 cells in liquid culture was 1,050 mg l(-1) day(-1). Moreover, the immobilized cells could maintain high efficacy and viability throughout 70 cycles of bioremedial treatment of diesel-contaminated water. The stability of diesel oil degradation in the immobilized cells resulted from the ability of living RN402 cells to attach to material surfaces by biofilm formation, as was shown by CLSM imaging. These characteristics of the immobilized RN402 cells, including high degradative efficacy, stability and flotation, make them suitable for the purpose of continuous wastewater bioremediation.

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

Science.gov (United States)

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

2016-02-02

A successful prescription is presented for acetylcholinesterase physically adsorbed on to a mesoporous silicon surface, with a promising hydrolytic response towards acetylthiocholine iodide. The catalytic behaviour of the immobilized enzyme was assessed by spectrophotometric bioassay using neostigmine methyl sulfate as a standard acetycholinesterase inhibitor. The surface modification was studied through field emission SEM, Fourier transform IR spectroscopy, energy-dispersive X-ray spectroscopy, cathode luminescence and X-ray photoelectron spectroscopy analysis, photoluminescence measurement and spectrophotometric bioassay. The porous silicon-immobilized enzyme not only yielded greater enzyme stability, but also significantly improved the native photoluminescence at room temperature of the bare porous silicon architecture. The results indicated the promising catalytic behaviour of immobilized enzyme compared with that of its free counterpart, with a greater stability, and that it aided reusability and easy separation from the reaction mixture. The porous silicon-immobilized enzyme was found to retain 50% of its activity, promising thermal stability up to 90°C, reusability for up to three cycles, pH stability over a broad pH of 4-9 and a shelf-life of 44 days, with an optimal hydrolytic response towards acetylthiocholine iodide at variable drug concentrations. On the basis of these findings, it was believed that the porous silicon-immobilized enzyme could be exploited as a reusable biocatalyst and for screening of acetylcholinesterase inhibitors from crude plant extracts and synthesized organic compounds. Moreover, the immobilized enzyme could offer a great deal as a viable biocatalyst in bioprocessing for the chemical and pharmaceutical industries, and bioremediation to enhance productivity and robustness. © 2016 Authors.

Increase in stability of cellulase immobilized on functionalized magnetic nanospheres

Science.gov (United States)

Zhang, Wenjuan; Qiu, Jianhui; Feng, Huixia; Zang, Limin; Sakai, Eiichi

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.

Visible and UV-curable chitosan derivatives for immobilization of biomolecules.

Science.gov (United States)

Kim, Eun-Hye; Han, Ga-Dug; Kim, Jae-Won; Noh, Seung-Hyun; Lee, Jae-Gwan; Ito, Yoshihiro; Son, Tae-Il

2017-11-01

Chitosan, which has many biocompatible properties, is used widely in medical field like wound healing, drug delivery and so on. Chitosan could be used as a biomaterial to immobilize protein-drug. There are many methods to immobilize protein-drug, but they have some drawbacks such as low efficiency and denaturation of protein. Therefore, photo-immobilization method is suggested to immobilize protein-drug. Photo-immobilization method is simple-reaction and also needs no additional crosslinking reagent. There has been some effort to modify chitosan to have an ability of photo-immobilization. Generally, visible and UV light reactive chitosan derivatives were prepared. Various types of photo-curable chitosan derivatives showed possibility for application to medical field. For example, they showed ability for protein-immobilization and some of them showed wound-healing effect, anti-adhesive effect, or property to interact directly with titanium surface. In this study, we introduce many types of photo-curable chitosan derivative and their possibility of medical application. Copyright © 2017 Elsevier B.V. All rights reserved.

Immobilization of cellulase on functionalized cobalt ferrite nanoparticles

International Nuclear Information System (INIS)

Bohara, Raghvendra Ashok; Thorat, Nanasaheb Devappa; Pawar, Shivaji Hariba

2016-01-01

Amine functionalized cobalt ferrite (AF-CoFe 2 O 4 ) magnetic nanoparticles (MNPs) were used for immobilization of cellulase enzyme via 1-ethyl-3-[3-dimethylaminopropyl] carbodiimide hydrochloride (EDS) and N-hydroxysuccinimide (NHS) coupling reaction. The structural, morphological and magnetic properties of AF-CoFe 2 O 4 were determined. TEM micrograph revealed a mean diameter of -8 nm and showed that the AF-CoFe 2 O 4 remain distinct with no significant change in size after binding with cellulase. Fourier transform infrared (FT-IR) spectroscopy confirmed the binding of cellulase to AF-CoFe 2 O 4 . The properties of immobilized cellulase were investigated by optimizing binding efficiency, pH, temperature and reusability. The results showed that the immobilized cellulase has higher thermal stability than free cellulase, which might be due to covalent interaction between cellulase and AF-CoFe 2 O 4 surface. The immobilized cellulase also showed good reusability after recovery. Therefore, AF-CoFe 2 O 4 MNPs can be considered as promising candidate for enzyme immobilization.

MUCOADHESIVE GEL WITH IMMOBILIZED LYSOZYME: PREPARATION AND PROPERTIES

Directory of Open Access Journals (Sweden)

Dekina S. S.

2015-08-01

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

Catalytical Properties of Free and Immobilized Aspergillus niger Tannase

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Abril Flores-Maltos

2011-01-01

Full Text Available A fungal tannase was produced, recovered, and immobilized by entrapment in calcium alginate beads. Catalytical properties of the immobilized enzyme were compared with those of the free one. Tannase was produced intracellularly by the xerophilic fungus Aspergillus niger GH1 in a submerged fermentation system. Enzyme was recovered by cell disruption and the crude extract was partially purified. The catalytical properties of free and immobilized tannase were evaluated using tannic acid and methyl gallate as substrates. KM and Vmax values for free enzyme were very similar for both substrates. But, after immobilization, KM and Vmax values increased drastically using tannic acid as substrate. These results indicated that immobilized tannase is a better biocatalyst than free enzyme for applications on liquid systems with high tannin content, such as bioremediation of tannery or olive-mill wastewater.

Catalytical Properties of Free and Immobilized Aspergillus niger Tannase.

Science.gov (United States)

Flores-Maltos, Abril; Rodríguez-Durán, Luis V; Renovato, Jacqueline; Contreras, Juan C; Rodríguez, Raúl; Aguilar, Cristóbal N

2011-01-01

A fungal tannase was produced, recovered, and immobilized by entrapment in calcium alginate beads. Catalytical properties of the immobilized enzyme were compared with those of the free one. Tannase was produced intracellularly by the xerophilic fungus Aspergillus niger GH1 in a submerged fermentation system. Enzyme was recovered by cell disruption and the crude extract was partially purified. The catalytical properties of free and immobilized tannase were evaluated using tannic acid and methyl gallate as substrates. K(M) and V(max) values for free enzyme were very similar for both substrates. But, after immobilization, K(M) and V(max) values increased drastically using tannic acid as substrate. These results indicated that immobilized tannase is a better biocatalyst than free enzyme for applications on liquid systems with high tannin content, such as bioremediation of tannery or olive-mill wastewater.

Immobilization of xanthine oxidase on a polyaniline silicone support.

Science.gov (United States)

Nadruz, W; Marques, E T; Azevedo, W M; Lima-Filho, J L; Carvalho, L B

1996-03-01

A polyaniline silicone support to immobilize xanthine oxidase is proposed as a reactor coil to monitor the action of xanthine oxidase on hypoxanthine, xanthine and 6-mercaptopurine. A purified xanthine oxidase immobilized on this support lost 80% of the initial activity after 12 min of use. Co-immobilization of superoxide dismutase and catalase increased the stability of immobilized xanthine oxidase so that the derivative maintained 79% of its initial activity after 4.6 h of continuous use in which 1.5 mumol purine bases were converted by the immobilized enzyme system. There is no evidence of either polyaniline or protein leaching from the coil during 3 h of continuous use. When solutions (10 ml) of hypoxanthine, xanthine and 6-mercaptopurine were circulated individually through the xanthine oxidase-superoxide dismutase-catalase-polyaniline coil (1 mm internal diameter and 3 m in length, 3 ml internal volume) activities of 8.12, 11.17 and 1.09 nmol min-1 coil-1, respectively, were obtained. The advantages of the reactor configuration and the redox properties of the polymer, particularly with respect to immobilized oxidoreductases, make this methodology attractive for similar enzyme systems. This immobilized enzyme system using polyaniline-silicone as support converted 6-mercaptopurine to 6-thiouric acid with equal efficiency as resins based on polyacrylamide and polyamide 11.

Immobilizing live Escherichia coli for AFM studies of surface dynamics

International Nuclear Information System (INIS)

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

2014-01-01

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

Platform for immobilization and observation of subcellular processes

Science.gov (United States)

McKnight, Timothy E.; Kalluri, Udaya C.; Melechko, Anatoli V.

2014-08-26

A method of immobilizing matter for imaging that includes providing an array of nanofibers and directing matter to the array of the nanofibers. The matter is immobilized when contacting at least three nanofibers of the array of nanofibers simultaneously. Adjacent nanofibers in the array of nanofibers may be separated by a pitch as great as 100 microns. The immobilized matter on the array of nanofibers may then be imaged. In some examples, the matter may be cell matter, such as protoplasts.

Computer-aided design of bromelain and papain covalent immobilization

OpenAIRE

Cutiño-Avila, Bessy; Gil Pradas, Dayrom; Aragón Abreu, Carlos; Fernández Marrero, Yuniel; Hernández de la Torre, Martha; Salas Sarduy, Emir; Chávez Planes, María de los Ángeles; Guisán Seijas, José Manuel; Díaz Brito, Joaquín; del Monte-Martínez, Alberto

2014-01-01

Enzymes as immobilized derivatives have been widely used in Food, Agrochemical, Pharmaceutical and Biotechnological industries. Protein immobilization is probably the most used technology to improve the operational stability of these molecules. Bromelain (Ananas comosus) and papain (Carica papaya) are cystein proteases extensively used as immobilized biocatalyst with several applications in therapeutics, racemic mixtures resolution, affinity chromatography and others industrial scenarios. The...

High-level waste immobilization program: an overview

International Nuclear Information System (INIS)

Bonner, W.R.

1979-09-01

The High-Level Waste Immobilization Program is providing technology to allow safe, affordable immobilization and disposal of nuclear waste. Waste forms and processes are being developed on a schedule consistent with national needs for immobilization of high-level wastes stored at Savannah River, Hanford, Idaho National Engineering Laboratory, and West Valley, New York. This technology is directly applicable to high-level wastes from potential reprocessing of spent nuclear fuel. The program is removing one more obstacle previously seen as a potential restriction on the use and further development of nuclear power, and is thus meeting a critical technological need within the national objective of energy independence

Immobilization routes - they're not standing still

Energy Technology Data Exchange (ETDEWEB)

Basta, N

1982-04-19

A review of the current stage of research into enzyme immobilization and the application of this technology in food processing and biomass-energy conversion is presented. The major success of the technology at present is the production of high-fructose corn syrup in the U.S. A commercial-scale plant to make sweeteners from cheese whey using immobilized lactase has come onstream in the U.K. Of two other processes reported, one uses immobilized bacteria to treat waste-water and produces pipeline-quality methane, the other holds promise for cutting the cost of corn-to-ethanol processing and enhancing the performance of cellulose-to-ethanol routes.

Preparation and characterization of two types of covalently immobilized amyloglucosidase

Directory of Open Access Journals (Sweden)

ZORAN VUJCIC

2005-05-01

Full Text Available Amyloglucosidase from A. niger was covalently immobilized onto poly (GMA-co-EGDMA by the glutaraldehyde and periodate method. The immobilization of amyloglucosidase after periodate oxidation gave a preparate with the highest specific activity reported so far on similar polymers. The obtained immobilized preparates show the same pH optimum, but a higher temperature optimum compared with the soluble enzyme. The kinetic parameters for the hydrolysis of soluble starch by free and both immobilized enzymes were determined.

Titration Behavior of Residues at the Entrance of the D-Pathway of Cytochrome c Oxidase from Paracoccus denitrificans Investigated by Continuum Electrostatic Calculations

International Nuclear Information System (INIS)

Olkhova, Elena; Helms, Volkhard H.; Michel, Hartmut

2005-01-01

Continuum electrostatic calculations were employed to investigate the titration curves of the fully oxidized state of wild type and several variants of cytochrome c oxidase from Paracoccus denitrificans (N131D, N131C, N131V, and D124N) for different values of the dielectric constant of the protein. The effects of the mutations at the entrance of the D-proton transfer pathway were found to be quite localized to their immediate surroundings. The results can be well interpreted in the light of the available biochemical and structural data and help understanding the effects of mutations on proton conductivity. The mutations of aspartic acid Asp-I-124 to a neutral residue resulted in a decreased pKa value of His-I-28 suggesting that the mutation of His-I-28 may have a significant influence on the coupling of electron and proton transfer in cytochrome c oxidase. We also investigated the effect of the mutations N131D, N131C, and N131V on the residue Glu-I-278 in terms of its pKa value and electrostatic interaction energies

Oxidation of inorganic compounds of sulphur by various sulphur bacteria

Energy Technology Data Exchange (ETDEWEB)

Parker, C D; Prisk, J

1953-01-01

Cultures of thiobacillus thiooxidans, Th. thioparus, Th. novellus, Thiobacillus b strains t and kand Th. concretivorus, Thiobacillus x and the m strains, organisms isolated from concrete were examined to elucidate the mode of oxidation and to establish the identity of the organisms recently isolated from corroded concrete. Thiosulphate was oxidized by all these bacteria. Th. thiooxidans, Th. concretivorus and Thiobacillus x first converted it to tetrathionate and sulphate and then oxidized the tetrathionate to sulphate and free sulphuric acid. Thiobaciullus x differed from the other two in that, owing to a lesser acid tolerance, some tetrathionate was found in the final products of oxidation. Th. Thioparus converted thiosulphate to sulphate and sulphur, followed by partial oxidation of the sulphur to sulphuric acid. Th. novellus produced sulphate and sulphuric acid. Thiobacillus b, the t and k strains and the m strains formed sulphate and tetrathionate with temporary increase in pH value; only Thiobacillus x oxidized tetrationate, yielding sulphate and sulphuric acid. Elementary sulphur was oxidized by Th. thiooxidans, th. Concretivorus, thiobacillus x and Th. thioparus; the rates of oxidation decreased in that order, and the only product was sulphuric acid. Hydrogen sulphide was oxidized only at low concentrations and only by th. Concretivorus and Thiobacillus x; sulphuric acid was the end-product, and elementary sulphur may have been an intermediate. Thiobacillus x differed from Th. thiooxidans in pH range for growth and from Th. thioparus in its method of oxidation of thiosulphate, tetrathionate and H/sub 2/S. The m strains were similar to thiobacillus b and the t and k strains of trautwein.

Electron beam technology for production of preparations of immobilized enzymes

International Nuclear Information System (INIS)

Gonchar, A.M.; Auslender, V.L.; Polyakov, V.A.

1995-01-01

Possibility of electron beam usage for proteases immobilization on 1,4-polyalkylene oxide (1,4-PAO) was studied to obtain biologically active complex for multi-purpose usage. It is shown that immobilization of Bacillus Subtilis protease is done due to free-radical linking of enzyme and carrier with formation of mycelium-like structures. Immobilization improves heat resistance of enzyme up to 60 centigrade without substrate and up to 80 centigrade in presence of substrate, widens range pH activity in comparison with non-immobilized forms. Immobilized proteases does not contain peroxides and long-live radicals. Our results permitted to create technologies for production of medical and veterinary preparations, active components for wool washing agents and leather fabrication technology

Studies on the preparation of immobilized enzymes by radiopolymerization, (9)

International Nuclear Information System (INIS)

Kawashima, Koji; Fujino, Satomi; Hayashi, Toru; Kim, Sung-K.

1982-01-01

Glucose Oxidase (GOD, EC 1, 1, 3, 4) was immobilized in the form of the beads by the radiation polymerization method under low temperature and the enzymatic characteristics were investigated. 1) Polyethyleneglycol dimethacrylate and acrylamide were favorable compounds for the immobilization of GOD. 2) Neither optimum pH nor pH stability was changed after immobilization treatment. 3) Optimum reaction temperature was shifted by 5 0 C to the higher side and heat stability was improved. 4) Immobilized GOD showed activity up to 60U per gram of dried polymer. 5) The small beads had retained high activities (10 - 80%) 6) The immobilized GOD was not leached out from the polymer matrix. (author)

Haloalkane hydrolysis with an immobilized haloalkane dehalogenase.

Science.gov (United States)

Dravis, B C; Swanson, P E; Russell, A J

2001-11-20

Haloalkane dehalogenase from Rhodococcus rhodochrous was covalently immobilized onto a polyethyleneimine impregnated gamma-alumina support. The dehalogenating enzyme was found to retain greater than 40% of its original activity after immobilization, displaying an optimal loading (max. activity/supported protein) of 70 to 75 mg/g with an apparent maximum (max. protein/support) of 156 mg/g. The substrate, 1,2,3-trichloropropane, was found to favorably partition (adsorb) onto the inorganic alumina carrier (10 to 20 mg/g), thereby increasing the local reactant concentration with respect to the catalyst's environment, whereas the product, 2,3-dichloropropan-1-ol, demonstrated no affinity. Additionally, the inorganic alumina support exhibited no adverse effects because of solvent/component incompatibilities or deterioration due to pH variance (pH 7.0 to 10.5). As a result of the large surface area to volume ratio of the support matrix and the accessibility of the bound protein, the immobilized biocatalyst was not subject to internal mass transfer limitations. External diffusional restrictions could be eliminated with simple agitation (mixing speed: 50 rpm; flux: 4.22 cm/min). The pH-dependence of the immobilized dehalogenase was essentially the same as that for the native enzyme. Finally, both the thermostability and resistance toward inactivation by organic solvent were improved by more than an order of magnitude after immobilization. Copyright 2001 John Wiley & Sons, Inc.

Biohydrogen production from rotten orange with immobilized mixed culture: Effect of immobilization media for various composition of substrates

Energy Technology Data Exchange (ETDEWEB)

Damayanti, Astrilia, E-mail: liasholehasd@gmail.com [Department of Chemical Engineering, Faculty of Engineering, Semarang State University, E1 Building, 2nd floor, Kampus Sekaran, Gunungpati, Semarang 50229 (Indonesia); Department of Chemical Engineering, Faculty of Engineering, Gadjah Mada University, Jl. Grafika No. 2, Kampus UGM, Yogyakarta 55281 (Indonesia); Sarto,; Syamsiah, Siti; Sediawan, Wahyudi B. [Department of Chemical Engineering, Faculty of Engineering, Gadjah Mada University, Jl. Grafika No. 2, Kampus UGM, Yogyakarta 55281 (Indonesia)

2015-12-29

Enriched–immobilized mixed culture was utilized to produce biohydrogen in mesophilic condition under anaerobic condition using rotten orange as substrate. The process was conducted in batch reactors for 100 hours. Microbial cultures from three different sources were subject to a series of enrichment and immobilized in two different types of media, i.e. calcium alginate (CA, 2%) and mixture of alginate and activated carbon (CAC, 1:1). The performance of immobilized culture in each media was tested for biohydrogen production using four different substrate compositions, namely orange meat (OM), orange meat added with peel (OMP), orange meat added with limonene (OML), and mixture of orange meat and peel added with limonene (OMPL). The results show that, with immobilized culture in CA, the variation of substrate composition gave significant effect on the production of biohydrogen. The highest production of biohydrogen was detected for substrate containing only orange meet, i.e. 2.5%, which was about 3-5 times higher than biohydrogen production from other compositions of substrate. The use of immobilized culture in CAC in general has increased the hydrogen production by 2-7 times depending on the composition of substrate, i.e. 5.4%, 4.8%, 5.1%, and 4.4% for OM, OMP, OML, and OMPL, respectively. The addition of activated carbon has eliminated the effect of inhibitory compounds in the substrate. The major soluble metabolites were acetic acid, propionic acid, and butyric acid.

Biohydrogen production from rotten orange with immobilized mixed culture: Effect of immobilization media for various composition of substrates

Science.gov (United States)

Damayanti, Astrilia; Sarto, Syamsiah, Siti; Sediawan, Wahyudi B.

2015-12-01

Enriched-immobilized mixed culture was utilized to produce biohydrogen in mesophilic condition under anaerobic condition using rotten orange as substrate. The process was conducted in batch reactors for 100 hours. Microbial cultures from three different sources were subject to a series of enrichment and immobilized in two different types of media, i.e. calcium alginate (CA, 2%) and mixture of alginate and activated carbon (CAC, 1:1). The performance of immobilized culture in each media was tested for biohydrogen production using four different substrate compositions, namely orange meat (OM), orange meat added with peel (OMP), orange meat added with limonene (OML), and mixture of orange meat and peel added with limonene (OMPL). The results show that, with immobilized culture in CA, the variation of substrate composition gave significant effect on the production of biohydrogen. The highest production of biohydrogen was detected for substrate containing only orange meet, i.e. 2.5%, which was about 3-5 times higher than biohydrogen production from other compositions of substrate. The use of immobilized culture in CAC in general has increased the hydrogen production by 2-7 times depending on the composition of substrate, i.e. 5.4%, 4.8%, 5.1%, and 4.4% for OM, OMP, OML, and OMPL, respectively. The addition of activated carbon has eliminated the effect of inhibitory compounds in the substrate. The major soluble metabolites were acetic acid, propionic acid, and butyric acid.

Biohydrogen production from rotten orange with immobilized mixed culture: Effect of immobilization media for various composition of substrates

International Nuclear Information System (INIS)

Damayanti, Astrilia; Sarto,; Syamsiah, Siti; Sediawan, Wahyudi B.

2015-01-01

Enriched–immobilized mixed culture was utilized to produce biohydrogen in mesophilic condition under anaerobic condition using rotten orange as substrate. The process was conducted in batch reactors for 100 hours. Microbial cultures from three different sources were subject to a series of enrichment and immobilized in two different types of media, i.e. calcium alginate (CA, 2%) and mixture of alginate and activated carbon (CAC, 1:1). The performance of immobilized culture in each media was tested for biohydrogen production using four different substrate compositions, namely orange meat (OM), orange meat added with peel (OMP), orange meat added with limonene (OML), and mixture of orange meat and peel added with limonene (OMPL). The results show that, with immobilized culture in CA, the variation of substrate composition gave significant effect on the production of biohydrogen. The highest production of biohydrogen was detected for substrate containing only orange meet, i.e. 2.5%, which was about 3-5 times higher than biohydrogen production from other compositions of substrate. The use of immobilized culture in CAC in general has increased the hydrogen production by 2-7 times depending on the composition of substrate, i.e. 5.4%, 4.8%, 5.1%, and 4.4% for OM, OMP, OML, and OMPL, respectively. The addition of activated carbon has eliminated the effect of inhibitory compounds in the substrate. The major soluble metabolites were acetic acid, propionic acid, and butyric acid

Immobilization of microbial cells: A promising tool for treatment of ...

African Journals Online (AJOL)

The review articles on cell immobilization have been published since 1980 and reflect the general interest in this topic. Immobilized microbial cells create opportunities in a wide range of sectors including environmental pollution control. Compared with suspended microorganism technology, cell immobilization shows many ...

Biosorption of uranium from wastewater by ZVI-SRB immobilized in calcium alginate

International Nuclear Information System (INIS)

Wang Aihe; Zhang Wei; Hu Kaiguang

2009-01-01

A ZVI-SRB was immobilized in calcium alginate gel beads,and the immobilized ZVI-SRB was used for removing uranium from wasterwater. The kinetics of uranium biosorption by the immobilized ZVI-SRB and the immobilized SRB was investigated. The results show that the immobilized ZVI-SRB and SRB were effective in removing uranium from wasterwater, and their maximal absorption capacities were up to 312.50 and 256.41 mg/g respectively. The kinetics of uranium biosorption onto the immobilized ZVI-SRB and SRB followed pseudo-second order model. (authors)

Treatment and immobilization of intermediate-level radioactive wastes

International Nuclear Information System (INIS)

Lerch, R.E.; Greenhalgh, W.O.; Partridge, J.A.; Richardson, G.L.

1979-01-01

A new program underway at the Hanford Engineering Development Laboratory (HEDL) to develop and demonstrate treatment and immobilization technologies for intermediate-level wastes (ILW) generated in the nuclear fuel cycle is discussed. ILW are defined as those liquid and solid radioactive wastes, other than high-level wastes and fuel cladding hulls, that in packaged form have radiation dose readings greater than 200 millirem/hr at the packaged surface and 10 millirem/hr at three feet from the surface. The IAEA value of 10 4 Ci/m 3 for ILW defines the upper limit. For comparative purposes, reference is also made to certain aspects of low-level radioactive wastes (LLW). Initial work has defined the sources, quantities and types of wastes which comprise ILW. Because of the wide differences in composition (e.g., acids, salt solutions, resins and zeolites, HEPA filters, etc.) the wastes may require different treatments, particularly those wastes containing volatile contaminants. The various types of ILW have been grouped into categories amenable to similar treatment. Laboratory studies are underway to define treatment technologies for liquid ILW which contain volatile contaminants and to define immobilization parameters for the residues resulting from treatment of ILW. Immobilization agents initially being evaluated for the various residues include cement, urea-formaldehyde, and bitumen although other immobilization agents will be studied. The program also includes development of acceptable test procedures for the final immobilized products as well as development of proposed criteria for storage, transportation, and disposal of the immobilized ILW

Immobilization of cellulase on functionalized cobalt ferrite nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Bohara, Raghvendra Ashok; Thorat, Nanasaheb Devappa; Pawar, Shivaji Hariba [Center for Interdisciplinary Research, D. Y. Patil University, Kolhapur (India)

2016-01-15

Amine functionalized cobalt ferrite (AF-CoFe{sub 2}O{sub 4}) magnetic nanoparticles (MNPs) were used for immobilization of cellulase enzyme via 1-ethyl-3-[3-dimethylaminopropyl] carbodiimide hydrochloride (EDS) and N-hydroxysuccinimide (NHS) coupling reaction. The structural, morphological and magnetic properties of AF-CoFe{sub 2}O{sub 4} were determined. TEM micrograph revealed a mean diameter of -8 nm and showed that the AF-CoFe{sub 2}O{sub 4} remain distinct with no significant change in size after binding with cellulase. Fourier transform infrared (FT-IR) spectroscopy confirmed the binding of cellulase to AF-CoFe{sub 2}O{sub 4}. The properties of immobilized cellulase were investigated by optimizing binding efficiency, pH, temperature and reusability. The results showed that the immobilized cellulase has higher thermal stability than free cellulase, which might be due to covalent interaction between cellulase and AF-CoFe{sub 2}O{sub 4} surface. The immobilized cellulase also showed good reusability after recovery. Therefore, AF-CoFe{sub 2}O{sub 4} MNPs can be considered as promising candidate for enzyme immobilization.

Immobilization of l-Asparaginase on Carrier Materials: A Comprehensive Review.

Science.gov (United States)

Ulu, Ahmet; Ates, Burhan

2017-06-21

There are two major applications of l-asparaginase (L-ASNase): leukemia therapy and the food industry. Especially, its chemotherapeutic effect has attracted interest from the scientific community and individual scientists. Therefore, to protect the intrinsic activity and half-time of L-ASNase, several carriers and immobilization techniques for immobilization of L-ASNase have been described in articles. Unfortunately, a comprehensive review about immobilization of L-ASNase has not been written until now. In this review, we have thoroughly discussed the carriers for L-ASNase by illustrating immobilization findings including both past and present applications. In addition, we have revealed advantages and disadvantages of immobilized enzyme and related it to free form. We believe that this review will not only provide background information, but also guide future developments.

Immobilization of antibodies and enzyme-labeled antibodies by radiation polymerization

International Nuclear Information System (INIS)

Kumakura, M.; Kaetsu, I.; Suzuki, M.; Adachi, S.

1983-01-01

Immobilization of antibodies and enzyme-labeled antibodies by radiation polymerization at low temperatures was studied. The antibody activity of antibody was not affected by irradiation at an irradiation dose of below 8 MR and low temperatures. Immobilization of peroxidase-labeled anti-rabbit IgG goat IgG, anti-peroxidase, peroxidase, and anti-alpha-fetoprotein was carried out with hydrophilic and hydrophobic monomers. The activity of the immobilized enzyme-labeled antibody membranes varied with the thickness of the membranes and increased with decreasing membrane thickness. The activity of the immobilized antibody particles was varied by particle size. Immobilized anti-alpha-fetoprotein particles and membranes can be used for the assay of alpha-fetoprotein by the antigen-antibody reaction, such as a solid-phase sandwich method with high sensitivity

Covalent immobilization of lipase from Candida rugosa on Eupergit®

Directory of Open Access Journals (Sweden)

Bezbradica Dejan I.

2005-01-01

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

Cell immobilization by radiation polymerization-a comparative study

International Nuclear Information System (INIS)

Dahlan bin Hj Mohd; Abu Bakar bin Salleh; Che Nyonya binti Abd Razak; Meheran binti Hamenudin; Kamaruzaman bin Ampon; Wan Md Zin bin Wan Yunus; Mahiran binti Basri

1991-01-01

An extracellular lipase producing fungus, Rhizopus rhizopodi formis was immobilised using radiation-induced polyHEMA, alginate and k-carrageenan. Immobilizations were done on spores since they showed better resistance against gamma radiation. The simultaneous radiation immobilization technique was found to be unsuitable because of contamination. Post-radiation immobilization using polyHEMA yielded 2-3 times more enzyme than the free cells. The value, however was slightly lower than the ones given by the cells immobilised using alginate or k-carrageenan, but the radiation-induced polymer was stronger and less likely to disintegrate

An orientation analysis method for protein immobilized on quantum dot particles

Energy Technology Data Exchange (ETDEWEB)

Aoyagi, Satoka, E-mail: aoyagi@life.shimane-u.ac.jp [Faculty of Life and Environmental Science, Shimane University, 1060 Matsue-shi, Shimane 690-8504 (Japan); Inoue, Masae [Toyota Central R and D Labs., Inc., Nagakute, Aichi 480-1192 (Japan)

2009-11-30

The evaluation of orientation of biomolecules immobilized on nanodevices is crucial for the development of high performance devices. Such analysis requires ultra high sensitivity so as to be able to detect less than one molecular layer on a device. Time-of-flight secondary ion mass spectrometry (TOF-SIMS) has sufficient sensitivity to evaluate the uppermost surface structure of a single molecular layer. The objective of this study is to develop an orientation analysis method for proteins immobilized on nanomaterials such as quantum dot particles, and to evaluate the orientation of streptavidin immobilized on quantum dot particles by means of TOF-SIMS. In order to detect fragment ions specific to the protein surface, a monoatomic primary ion source (Ga{sup +}) and a cluster ion source (Au{sub 3}{sup +}) were employed. Streptavidin-immobilized quantum dot particles were immobilized on aminosilanized ITO glass plates at amino groups by covalent bonding. The reference samples streptavidin directly immobilized on ITO plates were also prepared. All samples were dried with a freeze dryer before TOF-SIMS measurement. The positive secondary ion spectra of each sample were obtained using TOF-SIMS with Ga{sup +} and Au{sub 3}{sup +}, respectively, and then they were compared so as to characterize each sample and detect the surface structure of the streptavidin immobilized with the biotin-immobilized quantum dots. The chemical structures of the upper surface of the streptavidin molecules immobilized on the quantum dot particles were evaluated with TOF-SIMS spectra analysis. The indicated surface side of the streptavidin molecules immobilized on the quantum dots includes the biotin binding site.

Site-Selective Orientated Immobilization of Antibodies and Conjugates for Immunodiagnostics Development

Science.gov (United States)

Rusling, James

2016-01-01

Immobilized antibody systems are the key to develop efficient diagnostics and separations tools. In the last decade, developments in the field of biomolecular engineering and crosslinker chemistry have greatly influenced the development of this field. With all these new approaches at our disposal, several new immobilization methods have been created to address the main challenges associated with immobilized antibodies. Few of these challenges that we have discussed in this review are mainly associated to the site-specific immobilization, appropriate orientation, and activity retention. We have discussed the effect of antibody immobilization approaches on the parameters on the performance of an immunoassay. PMID:27876681

Effect of photo-immobilization of epidermal growth factor on the cellular behaviors

International Nuclear Information System (INIS)

Ogiwara, Kazutaka; Nagaoka, Masato; Cho, Chong-Su; Akaike, Toshihiro

2006-01-01

We constructed photo-reactive epidermal growth factor (EGF) bearing p-azido phenylalanine at the C-terminal (HEGFP) by genetic engineering to investigate the possibility of immobilized EGF as a novel artificial extracellular matrix (ECM). The constructed recombinant protein was immobilized to glass surface by ultraviolet irradiation. A431 cells adhered both to HEGFP-immobilized and collagen-coated surfaces. Interaction between immobilized HEGFP and EGF receptors in the A431 cells was independent of Mg 2+ although integrin-mediated cell adhesion to natural ECMs is dependent on Mg 2+ . Phosphorylation of EGF receptors in A431 cells was induced by immobilized HEGFP as same as soluble EGF. DNA uptake of hepatocytes decreased by immobilized HEGFP whereas it increased by soluble EGF. Liver-specific functions of hepatocytes were maintained for 3 days by immobilized HEGFP whereas they were not maintained by soluble EGF, indicating that immobilized HEGFP follows different signal transduction pathway from soluble EGF

Laser-assisted immobilization of colloid silver nanoparticles on polyethyleneterephthalate

Science.gov (United States)

Siegel, Jakub; Lyutakov, Oleksiy; Polívková, Markéta; Staszek, Marek; Hubáček, Tomáš; Švorčík, Václav

2017-10-01

Immobilization of nanoobjects on the surface of underlying material belongs to current issues of material science. Such altered materials exhibits completely exceptional properties exploitable in a broad spectrum of industrially important applications ranging from catalysts up to health-care industry. Here we present unique approach for immobilization of electrochemically synthesized silver nanoparticles on polyethyleneterephthalate (PET) foil whose essence lies in physical incorporation of particles into thin polymer surface layer induced by polarized excimer laser light. Changes in chemical composition and surface structure of polymer after particle immobilization were recorded by wide range of analytical techniques such as ARXPS, EDX, RBS, AAS, Raman, ICP-MS, DLS, UV-vis, SEM, TEM, and AFM. Thorough analysis of both nanoparticles entering the immobilization step as well as modified PET surface allowed revealing the mechanism of immobilization process itself. Silver nanoparticles were physically embedded into a thin surface layer of polymer reaching several nanometers beneath the surface rather than chemically bonded to PET macromolecules. Laser-implanted nanoparticles open up new possibilities especially in the development of the next generation cell-conform antimicrobial coatings of polymeric materials, namely due to the considerable immobilization strength which is strong enough to prevent particle release into the surrounding environment.

Production of cellulase from immobilized Trichoderma reesei

International Nuclear Information System (INIS)

Kasai, Noboru; Tamada, Masao; Kumakura, Minoru

1989-05-01

This report completed the results that obtained on the study of the enzyme activity in the culture of immobilized Trichoderma reesei cells in flask scale (100ml) and bench scale (30l). In the flask scale culture, the batch and repeated batch culture were carried out, and in the bench scale culture, the batch, repeated batch and continuous culture were done by using a culture equipment that is an unit process of the bench scale test plant for saccharification of cellulosic wastes. The enzyme activity of the immobilized cells was higher than that of the intact cells in the flask scale culture and it was confirmed that the enzyme activity was not decreased on the repeated batch culture of six times even. In the bench scale culture, it was found that a optimum culture condition of the immobilized cells was not different from that of the free cells and the immobilized cells gave the enzyme solution with a high enzyme activity in the culture condition of 450rpm stirring speed and air supply of 0.1v/v/m above. The technique of the repeated batch and continuous culture for long times in bench scale without contamination was established. The enzyme activity of the immobilized cells in continuous culture became to be 85 % to that in batch culture and it was found that the enzyme solution with high enzyme activity was continuously obtained in the continuous culture for long times. (author)

Synthesis and Characterization of Magnetic Carriers Based on Immobilized Enzyme

Science.gov (United States)

Li, F. H.; Tang, N.; Wang, Y. Q.; Zhang, L.; Du, W.; Xiang, J.; Cheng, P. G.

2018-05-01

Several new types of carriers and technologies have been implemented to improve traditional enzyme immobilization in industrial biotechnology. The magnetic immobilized enzyme is a kind of new method of enzyme immobilization developed in recent years. An external magnetic field can be used to control the motion mode and direction of immobilized enzyme, and to improve the catalytic efficiency of immobilized enzyme. In this paper, Fe3O4-CaCO3-PDA complex and CaCO3/Fe3O4 composite modified by PEI were prepared. The results show that the morphology of Fe3O4-CaCO3-PDA complex formation is irregular, while the morphology of CaCO3/Fe3O4 composite modified by PEI is regular and has a porous structure.

Catalytical Properties of Free and Immobilized Aspergillus niger Tannase

OpenAIRE

Abril Flores-Maltos; Luis V. Rodríguez-Durán; Jacqueline Renovato; Juan C. Contreras; Raúl Rodríguez; Cristóbal N. Aguilar

2011-01-01

A fungal tannase was produced, recovered, and immobilized by entrapment in calcium alginate beads. Catalytical properties of the immobilized enzyme were compared with those of the free one. Tannase was produced intracellularly by the xerophilic fungus Aspergillus niger GH1 in a submerged fermentation system. Enzyme was recovered by cell disruption and the crude extract was partially purified. The catalytical properties of free and immobilized tannase were evaluated using tannic acid and methy...

Evaluation of co-immobilized lactobacillus delbrueckii with porous particles for lactic acid production

Energy Technology Data Exchange (ETDEWEB)

Wang, H.; Seki, M.; Furusaki, S. [The University of Tokyo, Tokyo (Japan)

1996-02-01

Lactic acid production using co-immobilized L.defbrveckii with porous particles has been studied. The effect of co-immobilization with porous particles was verified by measuring the variations of both overall production rate of lactic acid and effective diffusion coefficient in the co-immobilized gel. The effective diffusion coefficient decreased with increasing cell concentration in the co-immobilized gel. However, in the high cell density regimes, the effective diffusion coefficient in co-immobilized gel was higher than that without co-immobilized porous particles. The optimal volume fraction of porous particles in the co-immobilizing gel beads leas estimated experimentally at about 10%(v/v). An approximately 30% increase of the overall production rate was obtained compared to the control culture. Mathematical analysis showed that by co-immobilizing cells with porous particles, the steady-state concentration profiles of proton and undissociated lactic acid changed favorably inside the gel beads. The result indicates that co-immobilization with porous particles is a useful method to improve fermentation efficiency in processes using immobilized cells. 19 refs., 8 figs.

Electrically conductive, immobilized bioanodes for microbial fuel cells

International Nuclear Information System (INIS)

Ganguli, R; Dunn, B

2012-01-01

The power densities of microbial fuel cells with yeast cells as the anode catalyst were significantly increased by immobilizing the yeast in electrically conductive alginate electrodes. The peak power densities measured as a function of the electrical conductivity of the immobilized electrodes show that although power increases with rising electrical conductivity, it tends to saturate beyond a certain point. Changing the pH of the anode compartment at that point seems to further increase the power density, suggesting that proton transport limitations and not electrical conductivity will limit the power density from electrically conductive immobilized anodes. (paper)

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

Energy Technology Data Exchange (ETDEWEB)

Liu, Yan; Gan, Li [School of Environmental Science and Engineering, Fujian Normal University, Fuzhou 350007, Fujian Province (China); Chen, Zuliang, E-mail: Zuliang.chen@unisa.edu.au [School of Environmental Science and Engineering, Fujian Normal University, Fuzhou 350007, Fujian Province (China); Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes, SA 5095 (Australia); Cooperative Research Centre for Contamination Assessment and Remediation of Environments, Mawson Lakes, SA 5095 (Australia); Megharaj, Mallavarapu; Naidu, Ravi [Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes, SA 5095 (Australia); Cooperative Research Centre for Contamination Assessment and Remediation of Environments, Mawson Lakes, SA 5095 (Australia)

2012-08-30

Highlights: Black-Right-Pointing-Pointer Paracoccus sp. immobilized on bamboo carbon used for the denitrification. Black-Right-Pointing-Pointer The rate of denitrification increased using the immobilized cells. Black-Right-Pointing-Pointer 99.8% denitrification was maintained after 10-cycle reuse. Black-Right-Pointing-Pointer 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.

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

International Nuclear Information System (INIS)

Liu, Yan; Gan, Li; Chen, Zuliang; Megharaj, Mallavarapu; Naidu, Ravi

2012-01-01

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.

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.

A multilayered polyurethane foam technique for skin graft immobilization.

Science.gov (United States)

Nakamura, Motoki; Ito, Erika; Kato, Hiroshi; Watanabe, Shoichi; Morita, Akimichi

2012-02-01

Several techniques are applicable for skin graft immobilization. Although the sponge dressing is a popular technique, pressure failure near the center of the graft is a weakness of the technique that can result in engraftment failure. To evaluate the efficacy of a new skin graft immobilization technique using multilayered polyurethane foam in vivo and in vitro. Twenty-six patients underwent a full-thickness skin graft. Multiple layers of a hydrocellular polyurethane foam dressing were used for skin graft immobilization. In addition, we created an in vitro skin graft model that allowed us to estimate immobilization pressure at the center and edges of skin grafts of various sizes. Overall mean graft survival was 88.9%. In the head and neck region (19 patients), mean graft survival was 93.6%. Based on the in vitro outcomes, this technique supplies effective pressure (skin graft. This multilayered polyurethane foam dressing is simple, safe, and effective for skin graft immobilization. © 2011 by the American Society for Dermatologic Surgery, Inc. Published by Wiley Periodicals, Inc.

Immobilization of Trichoderma reesei cells by radiation polymerization

International Nuclear Information System (INIS)

Kumakura, M.; Kaetsu, I.

1983-01-01

Trichoderma reesei cells were immobilized by radiation polymerization 2-hydroxyethyl acrylate monomer at low temperature. Cellulase production resulting from the growth of the cells in the porous polymer matrix of immobilized cell composites was confirmed by measuring the cellulase activity and pH during the culture. (orig.)

Laccase Immobilization by Chelated Metal Ion Coordination Chemistry

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Qingqing Wang

2014-09-01

Full Text Available In this work, amidoxime polyacrylonitrile (AOPAN nanofibrous membrane was prepared by a reaction between PAN nanofibers and hydroxylamine hydrochloride. The AOPAN nanofibrous membranes were used for four metal ions (Fe3+, Cu2+, Ni2+, Cd2+ chelation under different conditions. Further, the competition of different metal ions coordinating with AOPAN nanofibrous membrane was also studied. The AOPAN chelated with individual metal ion (Fe3+, Cu2+, Ni2+, Cd2+ and also the four mixed metal ions were further used for laccase (Lac immobilization. Compared with free laccase, the immobilized laccase showed better resistance to pH and temperature changes as well as improved storage stability. Among the four individual metal ion chelated membranes, the stability of the immobilized enzymes generally followed the order as Fe–AOPAN–Lac > Cu–AOPAN–Lac > Ni–AOPAN–Lac > Cd–AOPAN–Lac. In addition, the immobilized enzyme on the carrier of AOPAN chelated with four mixed metal ions showed the best properties.

Investigating the dynamics of surface-immobilized DNA nanomachines

Science.gov (United States)

Dunn, Katherine E.; Trefzer, Martin A.; Johnson, Steven; Tyrrell, Andy M.

2016-07-01

Surface-immobilization of molecules can have a profound influence on their structure, function and dynamics. Toehold-mediated strand displacement is often used in solution to drive synthetic nanomachines made from DNA, but the effects of surface-immobilization on the mechanism and kinetics of this reaction have not yet been fully elucidated. Here we show that the kinetics of strand displacement in surface-immobilized nanomachines are significantly different to those of the solution phase reaction, and we attribute this to the effects of intermolecular interactions within the DNA layer. We demonstrate that the dynamics of strand displacement can be manipulated by changing strand length, concentration and G/C content. By inserting mismatched bases it is also possible to tune the rates of the constituent displacement processes (toehold-binding and branch migration) independently, and information can be encoded in the time-dependence of the overall reaction. Our findings will facilitate the rational design of surface-immobilized dynamic DNA nanomachines, including computing devices and track-based motors.

Immobilization of leachable toxic soil pollutants by using oxidative enzymes

International Nuclear Information System (INIS)

Shannon, M.J.R.; Bartha, R.

1988-01-01

Screening of leachable toxic chemicals in a horseradish peroxidase-H 2 O 2 immobilization system established that immobilization was promising for most phenolic pollutants but not for benzoic acid, 2,6-dinitrocresol, or dibutyl phthalate. The treatment did not mobilize inherently nonmobile pollutants such as anilines and benzo[a]pyrene. In a separate study, an extracellular laccase in the culture filtrate of Geotrichum candidum was selected from five fungal enzymes evaluated as a cost-effective substitute for horseradish peroxidase. This enzyme was used in demonstrating the immobilization and subsequent fate of 14 C-labeled 4-methylphenol and 2,4-dichlorophenol in soil columns. When applied to Lakewood sand, 98.1% of 4-methylpheno was leached through with distilled water. Two days after immobilization treatment with the G. candidum culture filtrate, only 9.1% of the added 4-methylphenol was leached with the same volume of water. Of the more refractory test pollutant 2,4-dichlorophenol, 91.6% had leached at time zero and 48.5% had leached 1 day after the immobilization treatment. However, 2 weeks after immobilization, only 12.0% of the 2,4-dichlorophenol was leached compared with 61.7% from the control column that received no immobilization treatment. No remobilization of the bound pollutants was detected during 3- and 4-week incubation periods

Immobilization of acid digestion residue

International Nuclear Information System (INIS)

Greenhalgh, W.O.; Allen, C.R.

1983-01-01

Acid digestion treatment of nuclear waste is similar to incineration processes and results in the bulk of the waste being reduced in volume and weight to some residual solids termed residue. The residue is composed of various dispersible solid materials and typically contains the resultant radioactivity from the waste. This report describes the immobilization of the residue in portland cement, borosilicate glass, and some other waste forms. Diagrams showing the cement and glass virtification parameters are included in the report as well as process steps and candidate waste product forms. Cement immobilization is simplest and probably least expensive; glass vitrification exhibits the best overall volume reduction ratio

Preparation and Properties of Urease Immobilized onto Glutaraldehyde Cross-linked Chitosan Beads

Institute of Scientific and Technical Information of China (English)

Zu Pei LIANG; Ya Qing FENG; Shu Xian MENG; Zhi Yan LIANG

2005-01-01

Urease was immobilized onto the glutaraldehyde cross-linked chitosan beads that were prepared under microwave irradiation. The activity and the yield of activity of immobilized urease was 10.83 U/g B and 47.7%, respectively. The conditions of urease immobilization were optimized. The properties of the immobilized urease were investigated and compared with that of the free enzyme.

Characteristics of immobilized aminoacylase from Aspergillus oryzae on macroporous copolymers.

Science.gov (United States)

He, B L; Jiang, P; Qiu, Y B

1990-01-01

Aminoacylase from Aspergillus oryzae was adsorbed on functionallized macroporous copolymers where the enzyme showed excellent catalyzing activity and operation stability. Various factors which effect the activity of the immobilized aminoacylase such as temperature, pH and ionic strength were investigated. The continuous operation of the enzyme immobilized on macroporous copolymers was compared with that of the enzyme immobilized on DEAE-Sephadex.

PREPARATION AND CHARACTERIZATION OF BIOCATALYSTS BASED ON IMMOBILIZED GLYCOSIDASES

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O. L. Meshcheriakova

2014-01-01

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

Studies on the immobilization of biofunctional components by radiation polymerization and their applications

International Nuclear Information System (INIS)

Kaetsu, I.; Kumakura, M.; Fujimura, T.; Yoshida, M.; Asano, M.; Kasai, N.; Tamada, M.

1986-01-01

The recent progress on the studies of immobilization of various biofunctional components mainly by means of radiation polymerization as well as their practical applications to biomedical and biochemical fields were reviewed. The immobilization of drugs for the controlled release and targetting, the immobilization of antigens and antibodies for the immunodiagnosis, and the immobilization of microorganisms and tissue cells for the cell culture and the biomass conversion were the main topics in this review. The new findings on the enhanced immobilization methods and the polymeric carriers for immobilization were also attached. (author)

Short-term immobilization influences use-dependent cortical plasticity and fine motor performance.

Science.gov (United States)

Opie, George M; Evans, Alexandra; Ridding, Michael C; Semmler, John G

2016-08-25

Short-term immobilization that reduces muscle use for 8-10h is known to influence cortical excitability and motor performance. However, the mechanisms through which this is achieved, and whether these changes can be used to modify cortical plasticity and motor skill learning, are not known. The purpose of this study was to investigate the influence of short-term immobilization on use-dependent cortical plasticity, motor learning and retention. Twenty-one adults were divided into control and immobilized groups, both of which underwent two experimental sessions on consecutive days. Within each session, transcranial magnetic stimulation (TMS) was used to assess motor-evoked potential (MEP) amplitudes, short- (SICI) and long-interval intracortical inhibition (LICI), and intracortical facilitation (ICF) before and after a grooved pegboard task. Prior to the second training session, the immobilized group underwent 8h of left hand immobilization targeting the index finger, while control subjects were allowed normal limb use. Immobilization produced a reduction in MEP amplitudes, but no change in SICI, LICI or ICF. While motor performance improved for both groups in each session, the level of performance was greater 24-h later in control, but not immobilized subjects. Furthermore, training-related MEP facilitation was greater after, compared with before, immobilization. These results indicate that immobilization can modulate use-dependent plasticity and the retention of motor skills. They also suggest that changes in intracortical excitability are unlikely to contribute to the immobilization-induced modification of cortical excitability. Copyright © 2016. Published by Elsevier Ltd.

Immobilization of Gibberella fujikuroi cells with carriers modified by radiation polymerization

International Nuclear Information System (INIS)

Lu Zhaoxin; Xie Zhongchuan; Wei Qijiang

1994-01-01

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

Immobilization of periodate oxidized invertase by adsorption on sepiolite

Directory of Open Access Journals (Sweden)

RADIVOJE M. PRODANOVIC

2003-11-01

Full Text Available Periodate oxidized invertase was immobilized by adsorption on sepiolite. The obtained immobilized enzyme was more resistant to washing out by concentrated salt solution, and had an eight times higher half-life at 60ºC than adsorbed native invertase. In packed bed reactor 50 % conversion of 500 g/dm3 sucrose at 40ºC and a flow rate of 1 bv/h was achieved. The specific productivity of the immobilized invertase was 0.187 kg/dm3/h.

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

Directory of Open Access Journals (Sweden)

G. Arabaci

2013-01-01

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

Central nervous adaptations following 1 week of wrist and hand immobilization

DEFF Research Database (Denmark)

Lundbye-Jensen, Jesper; Nielsen, Jens Bo

2008-01-01

in relation to one week of immobilization of the non-dominant wrist and hand and a corresponding period of recovery in 10 able-bodied volunteers. Following immobilization maximal voluntary contraction torque (MVC) decreased and the variability of submaximal static contractions increased significantly without...... (MEPs) elicited by transcranial magnetic stimulation (TMS). Corticomuscular coherence measures were derived from EEG and EMG obtained during static contractions. Following immobilization corticomuscular coherence in the 15-35 Hz range associated with maximum negative cumulant values at lags...... motor cortex and spinal motoneuronal activity following immobilization. Key words: Plasticity, Immobilization, Motor Control....

Bed Rest and Immobilization: Risk Factors for Bone Loss

Science.gov (United States)

... Risk Factors for Bone Loss Bed Rest and Immobilization: Risk Factors for Bone Loss Like muscle, bone ... complications of pregnancy; and those who are experiencing immobilization of some part of the body because of ...

Characterization of cellulose acetate micropore membrane immobilized acylase I.

Science.gov (United States)

Guo, Yong-Sheng; Wang, Jie; Song, Xi-Jin

2004-12-01

This paper describes an innovative method for the immobilization of acylase I, which was entrapped into the CA-CTA micropore membrane. The most suitable casting solutions proportion for immobilizing the enzyme was obtained through orthogonal experiment. Properties of the enzyme membrane were investigated and compared with those of free enzyme and blank membrane. The thermal stability and pH stability of the enzyme inside the membrane were changed by immobilization. The optimum pH was found to be 6.0, which changes 1.0 unit compared with that of free acylase I. The optimum temperature was found to be about 90 degrees C, which is higher than that of free acylase I (60 degrees C). Experimental results showed that immobilization had effects on the kinetic parameters of acylase I.

Design and Properties of an Immobilization Enzyme System for Inulin Conversion.

Science.gov (United States)

Hang, Hua; Wang, Changbao; Cheng, Yiqun; Li, Ning; Song, Liuli

2018-02-01

A commercial inulinase could convert inulin into fructose, which was optimized to be entrapped in the calcium alginate-gelatin beads with the immobilization yield of 86% for free inulinase activities. The optimum pH values and temperatures were 4.5 and 40 °C for the free enzyme and 5.0-5.5 and 45-50 °C for the immobilized enzyme. The kinetic parameters of V max and K m were 5.24 μmol/min and 57.6 mg/mL for the free inulinase and 4.32 μmol/min and 65.8 mg/mL for the immobilized inulinase, respectively. The immobilized enzyme retained 80% of its initial activities at 45 °C for 4 days, which could exhibit better thermal stability. The reuse of immobilized inulinase throughout the continuous batch operations was explored, which had better reusability of the immobilized biocatalyst. At the same time, the stability of immobilized enzyme in the continuous packed-bed bioreactor was estimated, which showed the better results and had its potential scale-up fructose production for inulin conversion.

Management of primary anterior shoulder dislocations using immobilization.

Science.gov (United States)

Smith, Brent I; Bliven, Kellie C Huxel; Morway, Genoveffa R; Hurbanek, Jason G

2015-05-01

Reference/Citation : Paterson WH, Throckmorton TW, Koester M, Azar FM, Kuhn JE. Position and duration of immobilization after primary anterior shoulder dislocation: a systemic review and meta-analysis of the literature. J Bone Joint Surg Am. 2010;92(18):2924-2933. Does an optimum duration and position of immobilization after primary anterior shoulder dislocation exist for reducing recurrence rates? MEDLINE/PubMed, EMBASE, and Cochrane databases were searched up to December 2009 without limitations. The search terms for all databases used were shoulder AND dislocation and shoulder AND immobilization. Criteria used to include articles were (1) English language, (2) prospective level I or level II studies (according to Journal of Bone & Joint Surgery guidelines), (3) nonoperative management of initial anterior shoulder dislocation, (4) minimum follow-up of 1 year, and (5) rate of recurrent dislocation as a reported outcome. A standardized evaluation method was used to extract data to allow assessment of methods issues and statistical analysis to determine sources of bias. The primary outcome was the recurrence rate after nonoperative management of anterior shoulder dislocation. Additional data extracted and used in subanalyses included duration and position of immobilization and age at the time of initial dislocation. Data were analyzed to determine associations among groups using 2-tailed Fisher exact tests. For pooled categorical data, relative risk of recurrent dislocation, 95% confidence intervals, and heterogeneity using the I(2) statistic and χ(2) tests were calculated for individual studies. The Mantel-Haenszel method was used to combine studies and estimate overall relative risk of recurrent dislocation and 95% confidence intervals. The statistical difference between duration of immobilization and position was determined using z tests for overall effect. Pooled results were presented as forest plots. In the initial search of the databases, the authors

Studies of the immobilization of enzymes and microorganism pt.1

International Nuclear Information System (INIS)

Kim, S.K.

1979-01-01

A new method of immobilization of glucose oxidase by the aerobic gamma radiation of synthetic monomers was developed. The radiocopolymerization was conducted aerobically at -70 to-80 degC with the mixture of several polyfunctional esters, acrylates and native enzyme. The retained activity of immobilized glucoseoxidase was about 50 to 55% when a NK 23G ester, acrylamide-bis and water mixture (1:1:2) in cold toluene treated with 450 Krad of gamma radiation. The radiation dose did not influence significantly to the enzyme activity. The solvents used to prepare the beads of glucose oxidase and monomers were toluene, n-hexane, petoleum ether and chloroform. 0.05M tris-gycerol(pH 7.0) was a more suitable buffer solution for immobilizing the enzyme than was 0.02M phosphate. Immobilization of glucose oxidase shifted the optimum pH for its reaction from 6.0 to 6.5. The pH profile for the immobilized enzyme showed a broad range of optimum activity while the native enzyme gave a sharp pick for its optimum pH value. The immobilized enzyme reaction temperature was at the range of 30-40 degreesC. (Author)

High-level-waste immobilization

International Nuclear Information System (INIS)

Crandall, J.L.

1982-01-01

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

DOE materials program supporting immobilization of radioactive wastes

International Nuclear Information System (INIS)

Oertel, G.K.; Scheib, W.S. Jr.

1979-01-01

A summary is presented of the DOE program for developing waste-form criteria, immobilization processes, and generation and evaluation of performance characterization data. Interrelationships are discussed among repository design, materials requirements, immobilization process definition, quality assurance, and risk analysis as part of the National Environmental Policy Act and regulatory processes

Preparation and activity of bubbling-immobilized cellobiase within chitosan-alginate composite.

Science.gov (United States)

Wang, Fang; Su, Rong-Xin; Qi, Wei; Zhang, Ming-Jia; He, Zhi-Min

2010-01-01

Cellobiase can hydrolyze cellobiose into glucose; it plays a key role in the process of cellulose hydrolysis by reducing the product inhibition. To reuse the enzyme and improve the economic value of cellulosic ethanol, cellobiase was immobilized using sodium alginate and chitosan as carriers by the bubbling method. The immobilization conditions were optimized as follows: enzyme loading of 100 U cellobiase/g carrier, 30 min immobilization, 3.5 wt% sodium alginate, 0.25 wt% chitosan, and 2 wt% calcium chloride. Compared to free enzyme, the immobilized cellobiase had a decreased apparent K(m) and the maximum activity at a lower pH, indicating its higher acidic and thermal stability. The immobilized cellobiase was further tested in the hydrolysis of cellobiose and various cellulosic substrates (microcrystalline cellulose, filter paper, and ammonia-pretreated corn cobs). Together with cellulases, the immobilized cellobiase converted the cellulosic substrates into glucose with the rate and extent similar to the free enzyme.

Covalent immobilization of lipases on monodisperse magnetic microspheres modified with PAMAM-dendrimer

Energy Technology Data Exchange (ETDEWEB)

Zhu, Weiwei [Lanzhou University, State Key Laboratory of Applied Organic Chemistry, Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, College of Chemistry and Chemical Engineering, Institute of Biochemical Engineering and Environmental Technology (China); Zhang, Yimei [Suzhou Research Academy of North China Electric Power University (China); Hou, Chen; Pan, Duo; He, Jianjun; Zhu, Hao, E-mail: zhuhao07@lzu.edu.cn [Lanzhou University, State Key Laboratory of Applied Organic Chemistry, Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, College of Chemistry and Chemical Engineering, Institute of Biochemical Engineering and Environmental Technology (China)

2016-02-15

This paper reported an immobilization of Candida rugosa lipase (CRL) onto PAMAM-dendrimer-grafted magnetic nanoparticles synthesized by a modified solvothermal reduction method. The dendritic magnetic nanoparticles were amply characterized by several instrumental measurements, and the CRL was covalently anchored on the three generation supports with glutaraldehyde as coupling reagent. The amount of immobilized enzyme was up to 150 mg/g support and the factors related with the enzyme activity were investigated. The immobilization of lipase improved their performance in wider ranges of pH and temperature. The immobilized lipase exhibited excellent thermal stability and reusability in comparison with free enzyme and can be reused 10 cycles with the enzymatic activity remained above 90 %. The properties of lipase improved obviously after being immobilized on the dendritic supports. The inactive immobilized lipase could be regenerated with glutaraldehyde and Cu{sup 2+}, respectively. This synthetic strategy was facile and eco-friendly for applications in lipase immobilization.

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

Science.gov (United States)

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

2016-11-05

In order to prepare ultrafiltration membranes possessing biocatalytic properties, α-amylase has been immobilized on cellulose membranes. Enzyme immobilization was based on a covalent bonding between chitosan and a surface of cellulose membrane, followed by an attachment of Cibacron Blue F3G-A dye as affinity ligand. Various factors affecting the immobilization process, such as enzyme concentration, pH of modifying solution, zeta-potential of membrane surface, and stability of immobilized enzyme were studied. The applicability of immobilized α-amylase has been investigated in ultrafiltration processes. The immobilization of α-amylase on membrane surface allows to increase the value of mass transfer coefficient and to decrease the concentration polarization effect during ultrafiltration of starch solutions. The enzyme layer on the membrane surface prevents a rapid increase of starch concentration due to the amylase hydrolysis of starch in the boundary layer. The presented affinity immobilization technique allows also for the regeneration of membranes from inactivated enzyme. Copyright © 2016 Elsevier Ltd. All rights reserved.

Integrated development and testing plan for the plutonium immobilization project

International Nuclear Information System (INIS)

Kan, T.

1998-01-01

This integrated plan for the DOE Office of Fissile Materials Disposition (MD) describes the technology development and major project activities necessary to support the deployment of the immobilization approach for disposition of surplus weapons-usable plutonium. The plan describes details of the development and testing (D and T) tasks needed to provide technical data for design and operation of a plutonium immobilization plant based on the ceramic can-in-canister technology (''Immobilization Fissile Material Disposition Program Final Immobilization Form Assessment and Recommendation'', UCRL-ID-128705, October 3, 1997). The plan also presents tasks for characterization and performance testing of the immobilization form to support a repository licensing application and to develop the basis for repository acceptance of the plutonium form. Essential elements of the plant project (design, construction, facility activation, etc.) are described, but not developed in detail, to indicate how the D and T results tie into the overall plant project. Given the importance of repository acceptance, specific activities to be conducted by the Office of Civilian Radioactive Waste Management (RW) to incorporate the plutonium form in the repository licensing application are provided in this document, together with a summary of how immobilization D and T activities provide input to the license activity. The ultimate goal of the Immobilization Project is to develop, construct, and operate facilities that will immobilize from about 18 to 50 tonnes (MT) of U.S. surplus weapons usable plutonium materials in a manner that meets the ''spent fuel'' standard (Fissile Materials Storage and Disposition Programmatic Environmental Impact Statement Record of Decision, ''Storage and Disposition Final PEIS'', issued January 14, 1997, 62 Federal Register 3014) and is acceptable for disposal in a geologic repository. In the can-in-canister technology, this is accomplished by encapsulating the

Light transfer in agar immobilized microalgae cell cultures

Science.gov (United States)

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

2017-09-01

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

Determination of conformation and orientation of immobilized peptides and proteins at buried interfaces

Science.gov (United States)

Shen, Lei; Ulrich, Nathan W.; Mello, Charlene M.; Chen, Zhan

2015-01-01

Surface immobilized peptides/proteins have important applications such as antimicrobial coating and biosensing. We report a study of such peptides/proteins using sum frequency generation vibrational spectroscopy and ATR-FTIR. Immobilization on surfaces via physical adsorption and chemical coupling revealed that structures of chemically immobilized peptides are determined by immobilization sites, chemical environments, and substrate surfaces. In addition, controlling enzyme orientation by engineering the surface immobilization site demonstrated that structures can be well-correlated to measured chemical activity. This research facilitates the development of immobilized peptides/proteins with improved activities by optimizing their surface orientation and structure.

Immobilization of catalase on chitosan and amino acid- modified chitosan beads.

Science.gov (United States)

Başak, Esra; Aydemir, Tülin

2013-08-01

Bovine liver catalase was covalently immobilized onto amino acid-modified chitosan beads. The beads were characterized with SEM, FTIR, TGA and the effects of immobilization on optimum pH and temperature, thermostability, reusability were evaluated. Immobilized catalase showed the maximal enzyme activity at pH 7.0 at 30°C. The kinetic parameters, Km and Vmax, for immobilized catalase on alanine-chitosan beads and lysine-chitosan beads were estimated to be 25.67 mM, 27 mM and 201.39 μmol H2O2/min, 197.50 μmol H2O2/min, respectively. The activity of the immobilized catalase on Ala-CB and Lys-CB retained 40% of its high initial activity after 100 times of reuse.

Plutonium Immobilization Can Loading Conceptual Design

Energy Technology Data Exchange (ETDEWEB)

Kriikku, E.

1999-05-13

'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 glass for permanent storage. This report discusses the Plutonium Immobilization can loading conceptual design and includes a process block diagram, process description, preliminary equipment specifications, and several can loading issues. This report identifies loading pucks into cans and backfilling cans with helium as the top priority can loading development areas.'

Plutonium Immobilization Can Loading Conceptual Design

International Nuclear Information System (INIS)

Kriikku, E.

1999-01-01

'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 glass for permanent storage. This report discusses the Plutonium Immobilization can loading conceptual design and includes a process block diagram, process description, preliminary equipment specifications, and several can loading issues. This report identifies loading pucks into cans and backfilling cans with helium as the top priority can loading development areas.'

Covalent immobilization of invertase on PAMAM-dendrimer modified superparamagnetic iron oxide nanoparticles

International Nuclear Information System (INIS)

Uzun, K.; Cevik, E.; Senel, M.; Soezeri, H.; Baykal, A.; Abasiyanik, M. F.; Toprak, M. S.

2010-01-01

In this study, polyamidoamine (PAMAM) dendrimer was synthesized on the surface of superparamagnetite nanoparticles to enhance invertase immobilization. The amount of immobilized enzyme on the surface-hyperbranched magnetite nanoparticle was up to 2.5 times (i.e., 250%) as much as that of magnetite nanoparticle modified with only amino silane. Maximum reaction rate (V max ) and Michaelis-Menten constant (K m ) were determined for the free and immobilized enzymes. Various characteristics of immobilized invertase such as; the temperature activity, thermal stability, operational stability, and storage stability were evaluated and results revealed that stability of the enzyme is improved upon immobilization.

The effects of below-elbow immobilization on driving performance.

Science.gov (United States)

Jones, Evan M; Barrow, Aaron E; Skordas, Nic J; Green, David P; Cho, Mickey S

2017-02-01

There is limited research to guide physicians and patients in deciding whether it is safe to drive while wearing various forms of upper extremity immobilization. The purpose of this study is to evaluate the effect of below-elbow removable splints and fiberglass casts on automobile driving performance. 20 healthy subjects completed 10 runs through a closed, cone-marked driving course while wearing a randomized sequence of four different types of immobilization on each extremity (short arm thumb spica fiberglass cast, short arm fiberglass cast, short arm thumb spica splint, and short arm wrist splint). The first and last driving runs were without immobilization and served as controls. Performance was measured based on evaluation by a certified driving instructor (pass/fail scoring), cones hit, run time, and subject-perceived driving difficulty (1-10 analogue scoring). The greatest number of instructor-scored failures occurred while immobilized in right arm spica casts (n=6; p=0.02) and left arm spica casts (n=5; p=0.049). The right arm spica cast had the highest subject-perceived difficulty (5.2±1.9; pimmobilization had significantly increased perceived difficulty compared to control, except for the left short arm splint (2.5±1.6; p>0.05). There was no significant difference in number of cones hit or driving time between control runs and runs with any type of immobilization. Drivers should use caution when wearing any of the forms of upper extremity immobilization tested in this study. All forms of immobilization, with exception of the left short arm splint significantly increased perceived driving difficulty. However, only the fiberglass spica casts (both left and right arm), significantly increased drive run failures due to loss of vehicle control. We recommend against driving when wearing a below-elbow fiberglass spica cast on either extremity. Copyright © 2016. Published by Elsevier Ltd.

Enhanced activity and stability of L-arabinose isomerase by immobilization on aminopropyl glass.

Science.gov (United States)

Zhang, Ye-Wang; Jeya, Marimuthu; Lee, Jung-Kul

2011-03-01

Immobilization of Bacillus licheniformis L: -arabinose isomerase (BLAI) on aminopropyl glass modified with glutaraldehyde (4 mg protein g support⁻¹) was found to enhance the enzyme activity. The immobilization yield of BLAI was proportional to the quantity of amino groups on the surface of support. Reducing particle size increased the adsorption capacity (q(m)) and affinity (k(a)). The pH and temperature for immobilization were optimized to be pH 7.1 and 33 °C using response surface methodology (RSM). The immobilized enzyme was characterized and compared to the free enzyme. There is no change in optimal pH and temperature before and after immobilization. However, the immobilized BLAI enzyme achieved 145% of the activity of the free enzyme. Correspondingly, the catalytic efficiency (k(cat)/K(m)) was improved 1.47-fold after immobilization compared to the free enzyme. The thermal stability was improved 138-fold (t₁/₂) increased from 2 to 275 h) at 50 °C following immobilization.

Bioremediation of contaminated surface water by immobilized Micrococcus roseus.

Science.gov (United States)

Li, H; Li, P; Hua, T; Zhang, Y; Xiong, X; Gong, Z

2005-08-01

The problems caused by contaminated surface water have gradually become more serious in recent years. Although various remediation technologies were investigated, unfortunately, no efficient method was developed. In this paper, a new bioremediation technology was studied using Micrococcus roseus, which was immobilized in porous spherical beads by an improved polyvinyl alcohol (PVA) - sodium alginate (SA) embedding method. The experimental results indicated that COD removal rate could reach 64.7 % within 72 hours when immobilized M. roseus beads were used, which was ten times as high as that of free cells. The optimum inoculation rate of immobilized M. roseus beads was 10 % (mass percent of the beads in water sample, g g(-1)). Suitable aeration was proved necessary to enhance the bioremediation process. The immobilized cells had an excellent tolerance to pH and temperature changes, and were also more resistant to heavy metal stress compared with free cells. The immobilized M. roseus beads had an excellent regeneration capacity and could be reused after 180-day continuous usage. The Scanning Electronic Microscope (SEM) analysis showed that the bead microstructure was suitable for M. roseus growth, however, some defect structures should still be improved.

Immobilization as a route to surplus fissile materials disposition

International Nuclear Information System (INIS)

Gray, L.W.; Kan, T.

1995-01-01

In the aftermath of the Cold War, the US and Russia have 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 (Pu) in keeping with the national policy that Pu 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, the authors first reviewed published information on high-level waste (HLW) immobilization technologies in order to identify 72 possible Pu immobilization forms to be prescreened. Surviving forms were screened using multiattribute analysis to determine the most promising technologies. 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. All data, analyses, and reports are being provided to the DOE Fissile Materials Disposition Project Office to support the Record of Decision that is anticipated in the fourth quarter of FY96

Immobilization of iodine in concrete

Science.gov (United States)

Clark, Walter E.; Thompson, Clarence T.

1977-04-12

A method for immobilizing fission product radioactive iodine recovered from irradiated nuclear fuel comprises combining material comprising water, Portland cement and about 3-20 wt. % iodine as Ba(IO.sub.3).sub.2 to provide a fluid mixture and allowing the fluid mixture to harden, said Ba(IO.sub.3).sub.2 comprising said radioactive iodine. An article for solid waste disposal comprises concrete prepared by this method. BACKGROUND OF THE INVENTION This invention was made in the course of, or under a contract with the Energy Research and Development Administration. It relates in general to reactor waste solidification and more specifically to the immobilization of fission product radioactive iodine recovered from irradiated nuclear fuel for underground storage.

Improvement of thermal-stability of enzyme immobilized onto mesoporous zirconia

Directory of Open Access Journals (Sweden)

Yuichi Masuda

2014-03-01

Thereafter, FDH immobilized on MPZ showed higher catalytic activity than that on MPS. Enhancement of catalytic activity was obtained by improving the substrate affinity derived from interparticle voids of MPZ. In addition, the FDH immobilized on MPZ had a very great higher thermal stability. Further investigation using transmittance Infrared spectroscopy indicated that the high-order structure of the FDH immobilized on MPZ did not get altered after the heat-treatment.

Immobilization of enzyme and antibody by low energy electron beam polymerization

International Nuclear Information System (INIS)

Kaetsu, Isao; Kumakura, Minoru

1987-01-01

Immobilization of glucoamylase and AFP-antibody was studied using an electron beam of relatively low energy. A thin polymer membrane formed by irradiation of monomer enzyme mixture in a buffer, which had a considerable enzymatic activity. A membrane of almost the same thickness and activity was obtained by repeated irradiation. The effect of irradiation conditions on the immobilization and the variations of irradiation method for immobilization were investigated. The immobilization of antibody was carried out in similar ways as for enzyme, and the product also showed a considerable activity. (author)

Cost-effective immobilization for whole brain radiation therapy.

Science.gov (United States)

Rubinstein, Ashley E; Ingram, W Scott; Anderson, Brian M; Gay, Skylar S; Fave, Xenia J; Ger, Rachel B; McCarroll, Rachel E; Owens, Constance A; Netherton, Tucker J; Kisling, Kelly D; Court, Laurence E; Yang, Jinzhong; Li, Yuting; Lee, Joonsang; Mackin, Dennis S; Cardenas, Carlos E

2017-07-01

To investigate the inter- and intra-fraction motion associated with the use of a low-cost tape immobilization technique as an alternative to thermoplastic immobilization masks for whole-brain treatments. The results of this study may be of interest to clinical staff with severely limited resources (e.g., in low-income countries) and also when treating patients who cannot tolerate standard immobilization masks. Setup reproducibility of eight healthy volunteers was assessed for two different immobilization techniques. (a) One strip of tape was placed across the volunteer's forehead and attached to the sides of the treatment table. (b) A second strip was added to the first, under the chin, and secured to the table above the volunteer's head. After initial positioning, anterior and lateral photographs were acquired. Volunteers were positioned five times with each technique to allow calculation of inter-fraction reproducibility measurements. To estimate intra-fraction reproducibility, 5-minute anterior and lateral videos were taken for each technique per volunteer. An in-house software was used to analyze the photos and videos to assess setup reproducibility. The maximum intra-fraction displacement for all volunteers was 2.8 mm. Intra-fraction motion increased with time on table. The maximum inter-fraction range of positions for all volunteers was 5.4 mm. The magnitude of inter-fraction and intra-fraction motion found using the "1-strip" and "2-strip" tape immobilization techniques was comparable to motion restrictions provided by a thermoplastic mask for whole-brain radiotherapy. The results suggest that tape-based immobilization techniques represent an economical and useful alternative to the thermoplastic mask. © 2017 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine.

Simultaneous bioreduction of nitrate and chromate using sulfur-based mixotrophic denitrification process

Energy Technology Data Exchange (ETDEWEB)

Sahinkaya, Erkan, E-mail: erkansahinkaya@yahoo.com [Istanbul Medeniyet University, Bioengineering Department, Goztepe, Istanbul (Turkey); Kilic, Adem [Harran University, Environmental Engineering Department, Osmanbey Campus, 63000 Sanliurfa (Turkey); Calimlioglu, Beste; Toker, Yasemin [Istanbul Medeniyet University, Bioengineering Department, Goztepe, Istanbul (Turkey)

2013-11-15

Highlights: • Simultaneous heterotrophic and autotrophic denitrification was stimulated. • Simultaneous bioreduction of nitrate and chromate was achieved. • Total chromium decreased <50 μg/L when the influent Cr(VI) was ≤5 mg/L. -- Abstract: This study aims at evaluating simultaneous chromate and nitrate reduction using sulfur-based mixotrophic denitrification process in a column reactor packed with elemental sulfur and activated carbon. The reactor was supplemented with methanol at C/N ratio of 1.33 or 2. Almost complete denitrification was achieved at influent NO{sub 3}{sup −}–N and Cr(VI) concentrations of 75 mg/L and 10 mg/L, respectively, and 3.7 h HRT. Maximum denitrification rate was 0.5 g NO{sub 3}{sup −}–N/(L.d) when the bioreactor was fed with 75 mg/L NO{sub 3}{sup −}–N, 150 mg/L methanol and 10 mg/L Cr(VI). The share of autotrophic denitrification was between 12% and 50% depending on HRT, C/N ratio and Cr(VI) concentration. Effluent total chromium was below 50 μg/L provided that influent Cr(VI) concentration was equal or below 5 mg/L. DGGE results showed stable microbial community throughout the operation and the presence of sulfur oxidizing denitrifying bacteria (Thiobacillus denitrificans) and Cr(VI) reducing bacteria (Exiguobacterium spp.) in the column bed.

Uranium uptake by immobilized cells of Pseudomonas strain EPS 5028

International Nuclear Information System (INIS)

Pons, M.P.; Fuste, M.C.

1993-01-01

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.)

PVA-Glutaraldehyde as support for lectin immobilization and affinity chromatography

Directory of Open Access Journals (Sweden)

Moacyr Jesus Barreto de Melo Rêgo

2016-12-01

Full Text Available Immobilized lectins are a powerful biotechnological tool for separation and isolation of glycoconjugates. In the present study, polyvinyl alcohol (PVA and glutaraldehyde (GA were used as a support for Concanavalin A (Con A covalent immobilization and for entrapment of Parkia pendula seed gum (PpeG. Con A immobilization yielded approximately 30% and 0.6 M glucose solution was the minimum concentration able to elute fetuin from column. PVA-GA-PpeG column was efficiently recognized by pure P. pendula lectin (PpeL. These findings indicate that PVA-GA interpenetrated network showed to be an efficient support for lectin covalent immobilization and as affinity chromatography matrix after trapping of PpeG.

Materials Science of High-Level Nuclear Waste Immobilization

International Nuclear Information System (INIS)

Weber, William J.; Navrotsky, Alexandra; Stefanovsky, S. V.; Vance, E. R.; Vernaz, Etienne Y.

2009-01-01

With the increasing demand for the development of more nuclear power comes the responsibility to address the technical challenges of immobilizing high-level nuclear wastes in stable solid forms for interim storage or disposition in geologic repositories. The immobilization of high-level nuclear wastes has been an active area of research and development for over 50 years. Borosilicate glasses and complex ceramic composites have been developed to meet many technical challenges and current needs, although regulatory issues, which vary widely from country to country, have yet to be resolved. Cooperative international programs to develop advanced proliferation-resistant nuclear technologies to close the nuclear fuel cycle and increase the efficiency of nuclear energy production might create new separation waste streams that could demand new concepts and materials for nuclear waste immobilization. This article reviews the current state-of-the-art understanding regarding the materials science of glasses and ceramics for the immobilization of high-level nuclear waste and excess nuclear materials and discusses approaches to address new waste streams

Synthesis of glycinamides using protease immobilized magnetic nanoparticles

Directory of Open Access Journals (Sweden)

Abha Sahu

2016-12-01

Full Text Available In the present investigation, Bacillus subtilis was isolated from slaughterhouse waste and screened for the production of protease enzyme. The purified protease was successfully immobilized on magnetic nanoparticles (MNPs and used for the synthesis of series of glycinamides. The binding and thermal stability of protease on MNPs was confirmed by FTIR spectroscopy and TGA analysis. The surface morphology of MNPs before and after protease immobilization was carried out using SEM analysis. XRD pattern revealed no phase change in MNPs after enzyme immobilization. The processing parameters for glycinamides synthesis viz. temperature, pH, and time were optimized using Response Surface Methodology (RSM by using Design Expert (9.0.6.2. The maximum yield of various amides 2 butyramidoacetic acid (AMD-1,83.4%, 2-benzamidoacetic acid (AMD-2,80.5% and 2,2′((carboxymethyl amino-2-oxoethyl-2-hydroxysuccinylbis(azanediyldiacetic acid (AMD-3,80.8% formed was observed at pH-8, 50 °C and 30 min. The synthesized immobilized protease retained 70% of the initial activity even after 8 cycles of reuse.

Experimental investigation of activities and tolerance of denitrifying bacteria under alkaline and reducing condition

International Nuclear Information System (INIS)

Mine, Tatsuya; Mihara, Morihiro; Ooi, Takao

2000-07-01

In the geological disposal system of TRU wastes, nitrogen generation by denitrifying bacteria could provide significant impact on the assessment of this system, because nitrate contained in process concentrated liquid waste might be electron acceptor for denitrifying bacteria. In this study, the activities and tolerance of denitrifying under disposal condition were investigated. Pseudomonas denitrificans as denitrifying bacteria was used. The results showed that Pseudomonas denitrificans had activity under reducing condition, but under high pH condition (pH>9.5), the activity of Pseudomonas denitrificans was not detected. It is possible that the activity of Pseudomonas denitrificans would be low under disposal condition. (author)

Optimization of pectinase immobilization on grafted alginate-agar gel beads by 24 full factorial CCD and thermodynamic profiling for evaluating of operational covalent immobilization.

Science.gov (United States)

Abdel Wahab, Walaa A; Karam, Eman A; Hassan, Mohamed E; Kansoh, Amany L; Esawy, Mona A; Awad, Ghada E A

2018-07-01

Pectinase produced by a honey derived from the fungus Aspergillus awamori KX943614 was covalently immobilized onto gel beads made of alginate and agar. Polyethyleneimine, glutaraldehyde, loading time and enzyme's units were optimized by 2 4 full factorial central composite design (CCD). The immobilization process increased the optimal working pH for the free pectinase from 5 to a broader range of pH4.5-5.5 and the optimum operational temperature from 55°C to a higher temperature, of 60°C, which is favored to reduce the enzyme's microbial contamination. The thermodynamics studies showed a thermal stability enhancement against high temperature for the immobilized formula. Moreover, an increase in half-lives and D-values was achieved. The thermodynamic studies proved that immobilization of pectinase made a remarkable increase in enthalpy and free energy because of enzyme stability enhancement. The reusability test revealed that 60% of pectinase's original activity was retained after 8 successive cycles. This gel formula may be convenient for immobilization of other industrial enzymes. Copyright © 2018 Elsevier B.V. All rights reserved.

Safe immobilization of high-level nuclear reactor wastes

International Nuclear Information System (INIS)

Ringwood, A.; Kesson, S.; Ware, N.; Hibberson, W.; Major, A.

1979-01-01

The advantages and disadvantages of methods of immobilizing high-level radioactive wastes are discussed. Problems include the devitrification of glasses and the occurrence of radiation damage. An alternative method of radioctive waste immobilization is described in which the waste is incorporated in the constituent minerals of a synthetic rock, Synroc. Synroc is immune from devitrification and is composed of phases which possess crystal structures identical to those of minerals which are known to have retained radioactive elements in geological environments at elevated pressures and tempertures for long periods. The composition and mineralogy of Synroc is given and the process of immobilizing wastes in Synroc is described. Accelerated leaching tests at elevated pressures and temperatures are also described

Biosorption of 239Pu by immobilized sargassum fusiforme

International Nuclear Information System (INIS)

Liang Zhirong; Chen Qi; Wu Yusheng

2009-01-01

Sargassum fusiforme was immobilized with calcium alginates and its biosorption property to 239 Pu was studied by batch and column methods. Biosorption equilibrium time of immobilized Sargassum fusiforme biosorbent to 239 Pu is 120 min and biosorption efficiency is over 99.2% when the initial concentration of 239 Pu is 21.5 kBq/L and pH is 2.5-5.0. After five times repetition biosorption-desorption cycles biosorption efficiency is still over 98.0% when the velocity of flow is 2 ml/min in column experiment. Immobilized Sargassum fusiforme biosorbent is better to 239 Pu due to its better chemical stability, mechanical strength, lower cost, high biosorption efficiency and repeated biosorption-desorption cycles. (authors)

Immobilization technology for krypton in amorphous zeolite

International Nuclear Information System (INIS)

Takusagawa, Atsushi; Ishiyama, Keiichi

1989-01-01

Radioactive krypton recovered from the offgas of a reprocessing plant requires long-term storage on the order of 100 years. Immobilization technology for krypton into amorphous zeolite 5A is considered one of the best methods for long-term storage. In this report, conditions for immobilization treatment and stability of amorphous zeolite 5A loaded krypton against heat, radiation and water are discussed, and a treatment system using this technology is described. (author)

Electrochemical immobilization of biomolecules on gold surface modified with monolayered L-cysteine

Energy Technology Data Exchange (ETDEWEB)

Honda, Mitsunori, E-mail: honda.mitsunori@jaea.go.jp; Baba, Yuji; Sekiguchi, Tetsuhiro; Shimoyama, Iwao; Hirao, Norie

2014-04-01

Immobilization of organic molecules on the top of a metal surface is not easy because of lattice mismatch between organic and metal crystals. Gold atoms bind to thiol groups through strong chemical bonds, and a self-assembled monolayer of sulfur-terminated organic molecules is formed on the gold surface. Herein, we suggested that a monolayer of L-cysteine deposited on a gold surface can act as a buffer layer to immobilize biomolecules on the metal surface. We selected lactic acid as the immobilized biomolecule because it is one of the simplest carboxyl-containing biomolecules. The immobilization of lactic acid on the metal surface was carried out by an electrochemical method in an aqueous environment under the potential range varying from − 0.6 to + 0.8 V. The surface chemical states before and after the electrochemical reaction were characterized using X-ray photoelectron spectroscopy (XPS). The N 1s and C 1s XPS spectra showed that the L-cysteine-modified gold surface can immobilize lactic acid via peptide bonds. This technique might enable the immobilization of large organic molecules and biomolecules. - Highlights: • Monolayer l-cysteine deposited on Au surface as a buffer layer to immobilize biomolecules. • Lactic acid as the immobilized biomolecule as it is simple carboxyl-containing biomolecule. • X-ray photoelectron spectroscopy (XPS) of surface chemical states, before and after. • L-cysteine-modified Au surface can immobilize lactic acid via peptide bonds.

Electrochemical immobilization of biomolecules on gold surface modified with monolayered L-cysteine

International Nuclear Information System (INIS)

Honda, Mitsunori; Baba, Yuji; Sekiguchi, Tetsuhiro; Shimoyama, Iwao; Hirao, Norie

2014-01-01

Immobilization of organic molecules on the top of a metal surface is not easy because of lattice mismatch between organic and metal crystals. Gold atoms bind to thiol groups through strong chemical bonds, and a self-assembled monolayer of sulfur-terminated organic molecules is formed on the gold surface. Herein, we suggested that a monolayer of L-cysteine deposited on a gold surface can act as a buffer layer to immobilize biomolecules on the metal surface. We selected lactic acid as the immobilized biomolecule because it is one of the simplest carboxyl-containing biomolecules. The immobilization of lactic acid on the metal surface was carried out by an electrochemical method in an aqueous environment under the potential range varying from − 0.6 to + 0.8 V. The surface chemical states before and after the electrochemical reaction were characterized using X-ray photoelectron spectroscopy (XPS). The N 1s and C 1s XPS spectra showed that the L-cysteine-modified gold surface can immobilize lactic acid via peptide bonds. This technique might enable the immobilization of large organic molecules and biomolecules. - Highlights: • Monolayer l-cysteine deposited on Au surface as a buffer layer to immobilize biomolecules. • Lactic acid as the immobilized biomolecule as it is simple carboxyl-containing biomolecule. • X-ray photoelectron spectroscopy (XPS) of surface chemical states, before and after. • L-cysteine-modified Au surface can immobilize lactic acid via peptide bonds

Immobilization of Candida antarctica Lipase B by Adsorption to Green Coconut Fiber

Science.gov (United States)

Brígida, Ana I. S.; Pinheiro, Álvaro D. T.; Ferreira, Andrea L. O.; Gonçalves, Luciana R. B.

An agroindustrial residue, green coconut fiber, was evaluated as support for immobilization of Candida antarctica type B (CALB) lipase by physical adsorption. The influence of several parameters, such as contact time, amount of enzyme offered to immobilization, and pH of lipase solution was analyzed to select a suitable immobilization protocol. Kinetic constants of soluble and immobilized lipases were assayed. Thermal and operational stability of the immobilized enzyme, obtained after 2 h of contact between coconut fiber and enzyme solution, containing 40 U/ml in 25 mM sodium phosphate buffer pH 7, were determined. CALB immobilization by adsorption on coconut fiber promoted an increase in thermal stability at 50 and 60 °C, as half-lives (t 1/2) of the immobilized enzyme were, respectively, 2- and 92-fold higher than the ones for soluble enzyme. Furthermore, operational stabilities of methyl butyrate hydrolysis and butyl butyrate synthesis were evaluated. After the third cycle of methyl butyrate hydrolysis, it retained less than 50% of the initial activity, while Novozyme 435 retained more than 70% after the tenth cycle. However, in the synthesis of butyl butyrate, CALB immobilized on coconut fiber showed a good operational stability when compared to Novozyme 435, retaining 80% of its initial activity after the sixth cycle of reaction.

Immobilization of Chloroperoxidase on Aminopropyl-Glass

Science.gov (United States)

Kadima, Tenshuk A.; Pickard, Michael A.

1990-01-01

Chloroperoxidase (CPO) purified from Caldariomyces fumago CMI 89362 was covalently bound to aminopropyl-glass by using a modification of an established method. Acid-washed glass was derivatized by using aminopropyltriethoxysilane, and the enzyme was ionically bound at low ionic strength. Further treatment with glutaraldehyde covalently linked the enzyme to the glass beads in an active form. No elution of bound activity from glass beads could be detected with a variety of washings. The loading of enzyme protein to the glass beads was highest, 100 mg of CPO per g of glass, at high reaction ratios of CPO to glass, but the specific activity of the immobilized enzyme was highest, 36% of theoretical, at low enzyme-to-carrier ratios. No differences in the properties of the soluble and immobilized enzymes could be detected by a number of criteria: their pH-activity and pH-stability profiles were similar, as were their thermal stabilities. After five uses, the immobilized enzyme retained full activity between pH 6.0 and 6.7. PMID:16348352

The effects of using immobilizer made of the polyurethane foam

International Nuclear Information System (INIS)

Kim, Yong Hwan; Chung, Sang Hwa; Kim, Hwa Young; Lim, Shin Taek; Oh, Sae Dong

1992-01-01

The immogilzer for control the patient movement during the radiation beam on was made of the polyurethane foam. The time consumption is abut 8 minutes for completely making the immobilizer. In this experimental study, the effects of using the individual immobilizer have shown that the patients have had always a same position with comfortable and high reproducibilities. Furthermore, it has shown the time for patient setup was decreased by using the individual patient immobilizer.

Biomimetic mineralization of calcium carbonate/carboxymethylcellulose microspheres for lysozyme immobilization

International Nuclear Information System (INIS)

Lu Zheng; Zhang Juan; Ma Yunzi; Song Siyue; Gu Wei

2012-01-01

Porous calcium carbonate/carboxymethylcellulose (CaCO 3 /CMC) microspheres were prepared by the biomimetic mineralization method for lysozyme immobilization via adsorption. The size and morphology of CaCO 3 /CMC microspheres were characterized by transmitted electron microscopy (TEM) and zeta potential measurement. The lysozyme immobilization was verified by Fourier transform infrared (FTIR) spectroscopy. The effects of pHs and temperatures on lysozyme adsorption were investigated as well. It was revealed that CaCO 3 /CMC microspheres could immobilize lysozyme efficiently via electrostatic interactions and a maximum adsorption capacity of 450 mg/g was achieved at pH 9.2 and 25 °C. Moreover, it was found that the adsorption process fitted well with the Langmuir isothermal model. In addition, UV, fluorescence, and circular dichroism (CD) spectroscopic studies showed that lysozyme maintained its original secondary structure during the adsorption/desorption process. Our study therefore demonstrated that CaCO 3 /CMC microsphere can be used as a cost-effective and efficient support for lysozyme immobilization. - Graphical abstract: CaCO 3 /CMC microsphere was prepared by a facile biomimetic mineralization method and can be used as an efficient and cost-effective support for lysozyme immobilization. Highlights: ► CaCO 3 /CMC microspheres were prepared by the biomimetic mineralization method. ► Lysozyme was efficiently immobilized to CaCO 3 /CMC microspheres via adsorption. ► A maximum adsorption capacity of 450 mg/g was obtained at pH 9.2 and 25 °C. ► The original secondary structure of lysozyme was maintained upon immobilization.

Properties and Gamma Radiation Stability of Immobilized Alpha Amylase on Synthetic and Natural Polymer Blends

International Nuclear Information System (INIS)

Ismaill, S.A.; Mobasher, E.F.; Shousha, M.A.

2009-01-01

αAmylase was immobilized onto two different copolymers. One of them was chitosan/alginate copolymer. The other copolymer was N- isopropyl acrylamide and alginate. αAmylase was immobilized by entrapment method. The optimum temperature and thermal inactivation of the free enzyme and the immobilized one were investigated. The activity of the immobilized enzyme was stable at higher temperature. Immobilized enzyme was stable under different ph. The immobilized enzymes showed a slight decrease in the relative activity after being used 12 times. Storage of the free and immobilized enzymes for 2 months showed that the free αamylase lost most of its catalytic activity after storage at this period. The storage of the immobilized enzyme in dry state was much better than that in the wet state. Storage at room temperature showed much less stability of the immobilized enzyme than in 4 degree C. Exposure the free and immobilized enzymes to gamma- radiation at doses (0-50 kGy) showed complete loss in activity of free enzyme at 5 kGy, while the immobilized enzyme showed high resistance to gamma- radiation. The kinetic studies of free and immobilized enzymes showed that the immobilization process increased Km and decreased V m ax values of the enzyme

Properties and Gamma Radiation Stability of Immobilized Alpha Amylase on Synthetic and Natural Polymer Blends

International Nuclear Information System (INIS)

Ismaill, S.A.; Mobasher, E.F.; Shousha, M.A.

2008-01-01

αAmylase was immobilized onto two different copolymers. One of them was chitosan/alginate copolymer. The other copolymer was N- isopropyl acrylamide and alginate. αAmylase was immobilized by entrapment method. The optimum temperature and thermal inactivation of the free enzyme and the immobilized one were investigated. The activity of the immobilized enzyme was stable at higher temperature. Immobilized enzyme was stable under different ph. The immobilized enzymes showed a slight decrease in the relative activity after being used 12 times. Storage of the free and immobilized enzymes for 2 months showed that the free αamylase lost most of its catalytic activity after storage at this period. The storage of the immobilized enzyme in dry state was much better than that in the wet state. Storage at room temperature showed much less stability of the immobilized enzyme than in 4 degree C. Exposure the free and immobilized enzymes to gamma- radiation at doses (0-50 kGy) showed complete loss in activity of free enzyme at 5 kGy, while the immobilized enzyme showed high resistance to gamma- radiation. The kinetic studies of free and immobilized enzymes showed that the immobilization process increased Km and decreased V m ax values of the enzyme

Immobilization of wet solid wastes at nuclear power plants

International Nuclear Information System (INIS)

Neilson, R.M. Jr.

1977-01-01

Wet solid wastes are classified into four basic types: spent resins, filter sludges, evaporator concentrates, and miscellaneous liquids. Although the immobilization of wet solid wastes is primarily concerned with the incorporation of the waste with a solidification agent, there are a number of other discrete operations or subsystems involved in the treatment of these wastes that may affect the immobilized waste product. The immobilization process may be broken down into five basic operations: waste collection, waste pretreatment, solidification agent handling, mixing/packaging, and waste package handling. The properties of the waste forms that are ultimately shipped from the reactor site are primarily influenced by the methods utilized during the waste collection, waste pretreatment and mixing/packaging operations. The mixing/packaging (solidification) operation is perhaps the most important stage of the immobilization process. The basic solidification agent types are: absorbants, hydraulic cement, urea-formaldehyde, bitumen, and other polymer systems

pH-dependent immobilization of urease on glutathione-capped gold nanoparticles.

Science.gov (United States)

Garg, Seema; De, Arnab; Mozumdar, Subho

2015-05-01

Urease is a nickel-dependent metalloenzyme that catalyzes the hydrolysis of urea to form ammonia and carbon dioxide. Although the enzyme serves a significant role in several detoxification and analytical processes, its usability is restricted due to high cost, availability in small amounts, instability, and a limited possibility of economic recovery from a reaction mixture. Hence, there is a need to develop an efficient, simple, and reliable immobilization strategy for the enzyme. In this study, the carboxyl terminated surface of glutathione-capped gold nanoparticles have been utilized as a solid support for the covalent attachment of urease. The immobilization has been carried out at different pH conditions so as to elucidate its effect on the immobilization efficiency and enzyme bioactivity. The binding of the enzyme has been quantitatively and qualitatively analyzed through techniques like ultraviolet-visible spectroscopy, intrinsic steady state fluorescence, and circular dichorism. The bioactivity of the immobilized enzyme was investigated with respect to the native enzyme under different thermal conditions. Recyclability and shelf life studies of the immobilized enzyme have also been carried out. Results reveal that the immobilization is most effective at pH of 7.4 followed by that in an acidic medium and is least in alkaline environment. The immobilized enzyme also exhibits enhance activity in comparison to the native form at physiological temperature. The immobilized urease (on gold glutathione nanoconjugates surface) can be effectively employed for biosensor fabrication, immunoassays and as an in vivo diagnostic tool in the future. © 2014 Wiley Periodicals, Inc.

Plutonium immobilization plant using ceramic in existing facilities at the Savannah River site

International Nuclear Information System (INIS)

DiSabatino, A.

1998-01-01

The Plutonium Immobilization Plant (PIP) accepts plutonium (Pu) from pit conversion and from non-pit sources, and through a ceramic immobilization process converts the plutonium into an immobilized form that can be disposed of in a high level waste (HLW) repository. This immobilization process is shown conceptually in Figure 1-1. The objective is to make an immobilized form, suitable for geologic disposal, in which the plutonium is as inherently unattractive and inaccessible as the plutonium in spent fuel from commercial reactors. The ceramic immobilization alternative presented in this report consists of first converting the surplus material to an oxide, followed by incorporating the plutonium oxide into a titanate-based ceramic material that is placed in metal cans

Immobilization of swift foxes with ketamine hydrochloride-xylazine hydrochloride

Science.gov (United States)

Telesco, R.L.; Sovada, Marsha A.

2002-01-01

There is an increasing need to develop field immobilization techniques that allow researchers to handle safely swift foxes (Vulpes velox) with minimal risk of stress or injury. We immobilized captive swift foxes to determine the safety and effectiveness of ketamine hydrochloride and xylazine hydrochloride at different dosages. We attempted to determine appropriate dosages to immobilize swift foxes for an adequate field-handling period based on three anesthesia intervals (induction period, immobilization period, and recovery period) and physiologic responses (rectal temperature, respiration rate, and heart rate). Between October 1998–July 1999, we conducted four trials, evaluating three different dosage ratios of ketamine and xylazine (2.27:1.2, 5.68:1.2, and 11.4:1.2 mg/kg ketamine:mg/kg xylazine, respectively), followed by a fourth trial with a higher dosage at the median ratio (11.4 mg/kg ketamine:2.4 mg/kg xylazine). We found little difference in induction and recovery periods among trials 1–3, but immobilization time increased with increasing dosage (Pimmobilization period and recovery period increased in trial 4 compared with trials 1–3 (P≤0.03). There was a high variation in responses of individual foxes across trials, making it difficult to identify an appropriate dosage for field handling. Heart rate and respiration rates were depressed but all physiologic measures remained within normal parameters established for domestic canids. We recommend a dosage ratio of 10 mg/kg ketamine to 1 mg/kg xylazine to immobilize swift foxes for field handling.

Ameliorating Hemorheology by Direct Hemoperfusion with a Polymyxin B-immobilized Adsorbent

Institute of Scientific and Technical Information of China (English)

Li Yuan; Wang Xiang; Gao Wei; Cai Shaoxi

2004-01-01

Direct hemoperfusion (DHP) with an adsorbent column using polymyxin B-immobilized polystyrene beads has been used to investigate the changes of hemorheology in rabbits with endotoxemia. We measured whole blood viscosity and hemotocrit before and after DHP with polymyxin B-immobilized polystyrene beads. Reduction in blood endotoxin concentration by DHP therapy positively correlated with improvement in hemorheological indexs. Our findings indicate that the amelioration in hemorheology was related directly to endotoxin removal by the adsorbent column with polymyxin B-immobilize polystyrene beads. So DHP with polymyxin B-immobilized polystyrene beads seems to be an important therapeutic strategy for endotoxemia.

Alternatives generation and analysis report for immobilized low-level waste interim storage architecture

Energy Technology Data Exchange (ETDEWEB)

Burbank, D.A., Westinghouse Hanford

1996-09-01

The Immobilized Low-Level Waste Interim Storage subproject will provide storage capacity for immobilized low-level waste product sold to the U.S. Department of Energy by the privatization contractor. This report describes alternative Immobilized Low-Level Waste storage system architectures, evaluation criteria, and evaluation results to support the Immobilized Low-Level Waste storage system architecture selection decision process.

Immobilization of biomolecules onto surfaces according to ultraviolet light diffraction patterns

International Nuclear Information System (INIS)

Bjoern Petersen, Steffen; Kold di Gennaro, Ane; Neves-Petersen, Maria Teresa; Skovsen, Esben; Parracino, Antonietta

2010-01-01

We developed a method for immobilization of biomolecules onto thiol functionalized surfaces according to UV diffraction patterns. UV light-assisted molecular immobilization proceeds through the formation of free, reactive thiol groups that can bind covalently to thiol reactive surfaces. We demonstrate that, by shaping the pattern of the UV light used to induce molecular immobilization, one can control the pattern of immobilized molecules onto the surface. Using a single-aperture spatial mask, combined with the Fourier transforming property of a focusing lens, we show that submicrometer (0.7 μm) resolved patterns of immobilized prostate-specific antigen biomolecules can be created. If a dual-aperture spatial mask is used, the results differ from the expected Fourier transform pattern of the mask. It appears as a superposition of two diffraction patterns produced by the two apertures, with a fine structured interference pattern superimposed.

Hierarchically Nanoporous Bioactive Glasses for High Efficiency Immobilization of Enzymes

DEFF Research Database (Denmark)

He, W.; Min, D.D.; Zhang, X.D.

2014-01-01

Bioactive glasses with hierarchical nanoporosity and structures have been heavily involved in immobilization of enzymes. Because of meticulous design and ingenious hierarchical nanostructuration of porosities from yeast cell biotemplates, hierarchically nanostructured porous bioactive glasses can...... and products of catalytic reactions can freely diffuse through open mesopores (2–40 nm). The formation mechanism of hierarchically structured porous bioactive glasses, the immobilization mechanism of enzyme and the catalysis mechanism of immobilized enzyme are then discussed. The novel nanostructure...

Covalent immobilization of β-glucosidase on magnetic particles for lignocellulose hydrolysis.

Science.gov (United States)

Alftrén, Johan; Hobley, Timothy John

2013-04-01

β-Glucosidase hydrolyzes cellobiose to glucose and is an important enzyme in the consortium used for hydrolysis of cellulosic and lignocellulosic feedstocks. In the present work, β-glucosidase was covalently immobilized on non-porous magnetic particles to enable re-use of the enzyme. It was found that particles activated with cyanuric chloride and polyglutaraldehyde gave the highest bead-related immobilized enzyme activity when tested with p-nitrophenyl-β-D-glucopyranoside (104.7 and 82.2 U/g particles, respectively). Furthermore, the purified β-glucosidase preparation from Megazyme gave higher bead-related enzyme activities compared to Novozym 188 (79.0 and 9.8 U/g particles, respectively). A significant improvement in thermal stability was observed for immobilized enzyme compared to free enzyme; after 5 h (at 65 °C), 36 % of activity remained for the former, while there was no activity in the latter. The performance and recyclability of immobilized β-glucosidase on more complex substrate (pretreated spruce) was also studied. It was shown that adding immobilized β-glucosidase (16 U/g dry matter) to free cellulases (8 FPU/g dry matter) increased the hydrolysis yield of pretreated spruce from ca. 44 % to ca. 65 %. In addition, it was possible to re-use the immobilized β-glucosidase in the spruce and retain activity for at least four cycles. The immobilized enzyme thus shows promise for lignocellulose hydrolysis.

Catalytic properties of immobilized tannase produced from Aspergillus aculeatus compared with the free enzyme

Directory of Open Access Journals (Sweden)

A. B El-Tanash

2011-09-01

Full Text Available Aspergillus aculeatus tannase was immobilized on several carriers by entrapment and covalent binding with cross - linking. Tannase immobilized on gelatin with cross - linking agent showed the highest activity and immobilization yield. The optimum pH of the immobilized enzyme was shifted to a more acidic range compared with the free enzyme (from pH 5.5 to pH 5.0. The optimum temperature of the reaction was determined to be 50ºC for the free enzyme and 60ºC for the immobilized form. The thermal stability, as well as stability over a wide range of pH, was significantly improved by the immobilization process. The calculated Km of the immobilized tannase (11.8 mg ml-1 is higher than that of the free tannase (6.5 mg ml-1, while Vmax of the immobilized enzyme (0.32 U (µg protein-1 is lower than that of the free tannase (2.7 U (µg protein-1. The immobilized enzyme was able to retain 84 % of the initial catalytic activity after 5.0 cycles.

End-Point Immobilization of Recombinant Thrombomodulin via Sortase-Mediated Ligation

Science.gov (United States)

Jiang, Rui; Weingart, Jacob; Zhang, Hailong; Ma, Yong; Sun, Xue-Long

2012-01-01

We report an enzymatic end-point modification and immobilization of recombinant human thrombomodulin (TM), a cofactor for activation of anticoagulant protein C pathway via thrombin. First, a truncated TM mutant consisting of epidermal growth factor-like domains 4–6 (TM456) with a conserved pentapeptide LPETG motif at its C-terminal was expressed and purified in E. coli. Next, the truncated TM456 derivative was site-specifically modified with N-terminal diglycine containing molecules such as biotin and the fluorescent probe dansyl via sortase A (SrtA) mediated ligation (SML). The successful ligations were confirmed by SDS-PAGE and fluorescence imaging. Finally, the truncated TM456 was immobilized onto N-terminal diglycine-functionalized glass slide surface via SML directly. Alternatively, the truncated TM456 was biotinylated via SML and then immobilized onto streptavidin-functionalized glass slide surface indirectly. The successful immobilizations were confirmed by fluorescence imaging. The bioactivity of the immobilized truncated TM456 was further confirmed by protein C activation assay, in which enhanced activation of protein C by immobilized recombinant TM was observed. The sortase A-catalyzed surface ligation took place under mild conditions and is rapid occurring in a single step without prior chemical modification of the target protein. This site-specific covalent modification leads to molecules being arranged in a definitively ordered fashion and facilitating the preservation of the protein’s biological activity. PMID:22372933

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.

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.

Dental pulp stem cells immobilized in alginate microspheres for applications in bone tissue engineering.

Science.gov (United States)

Kanafi, M M; Ramesh, A; Gupta, P K; Bhonde, R R

2014-07-01

To immobilize dental pulp stem cells (DPSC) in alginate microspheres and to determine cell viability, proliferation, stem cell characteristics and osteogenic potential of the immobilized DPSCs. Human DPSCs isolated from the dental pulp were immobilized in 1% w/v alginate microspheres. Viability and proliferation of immobilized DPSCs were determined by trypan blue and MTT assay, respectively. Stem cell characteristics of DPSCs post immobilization were verified by labelling the cells with CD73 and CD90. Osteogenic potential of immobilized DPSCs was assessed by the presence of osteocalcin. Alizarin red staining and O-cresolphthalein complexone method confirmed and quantified calcium deposition. A final reverse transcriptase PCR evaluated the expression of osteogenic markers - ALP, Runx-2 and OCN. More than 80% of immobilized DPSCs were viable throughout the 3-week study. Proliferation appeared controlled and consistent unlike DPSCs in the control group. Presence of CD73 and CD90 markers confirmed the stem cell nature of immobilized DPSCs. The presence of osteocalcin, an osteoblastic marker, was confirmed in the microspheres on day 21. Mineralization assays showed high calcium deposition indicating elevated osteogenic potential of immobilized DPSCs. Osteogenic genes- ALP, Runx-2 and OCN were also upregulated in immobilized DPSCs. Surprisingly, immobilized DPSCs in the control group cultured in conventional stem cell media showed upregulation of osteogenic genes and expressed osteocalcin. Dental pulp stem cells immobilized in alginate hydrogels exhibit enhanced osteogenic potential while maintaining high cell viability both of which are fundamental for bone tissue regeneration. © 2013 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Substrate Specificity and Enzyme Recycling Using Chitosan Immobilized Laccase

Directory of Open Access Journals (Sweden)

Everton Skoronski

2014-10-01

Full Text Available The immobilization of laccase (Aspergillus sp. on chitosan by cross-linking and its application in bioconversion of phenolic compounds in batch reactors were studied. Investigation was performed using laccase immobilized via chemical cross-linking due to the higher enzymatic operational stability of this method as compared to immobilization via physical adsorption. To assess the influence of different substrate functional groups on the enzyme’s catalytic efficiency, substrate specificity was investigated using chitosan-immobilized laccase and eighteen different phenol derivatives. It was observed that 4-nitrophenol was not oxidized, while 2,5-xylenol, 2,6-xylenol, 2,3,5-trimethylphenol, syringaldazine, 2,6-dimetoxyphenol and ethylphenol showed reaction yields up 90% at 40 °C. The kinetic of process, enzyme recyclability and operational stability were studied. In batch reactors, it was not possible to reuse the enzyme when it was applied to syringaldazne bioconversion. However, when the enzyme was applied to bioconversion of 2,6-DMP, the activity was stable for eight reaction batches.

Remote handling in the Plutonium Immobilization Project: Puck handling

International Nuclear Information System (INIS)

Brault, J.R.

2000-01-01

Since the break up of the Soviet Union at the end of the Cold War, the US and Russia have been negotiating ways to reduce their nuclear stockpiles. Economics is one of the reasons behind this, but another important reason is safeguarding these materials from unstable organizations and countries. With the downsizing of the nuclear stockpiles, large quantities of plutonium are being declared excess and must be safely disposed of. The Savannah River Site (SRS) has been selected as the site where the immobilization facility will be located. Conceptual design and process development commenced in 1998. SRS will immobilize excess plutonium in a ceramic waste form and encapsulate it in vitrified high level waste in the Defense Waste Processing Facility (DWPF) canister. These canisters will then be interred in the national repository at Yucca Mountain, New Mexico. The facility is divided into three distinct operating areas: Plutonium Conversion, First Stage Immobilization, and Second Stage Immobilization. This paper will discuss the first two operations

Cellulase immobilization on magnetic nanoparticles encapsulated in polymer nanospheres.

Science.gov (United States)

Lima, Janaina S; Araújo, Pedro H H; Sayer, Claudia; Souza, Antonio A U; Viegas, Alexandre C; de Oliveira, Débora

2017-04-01

Immobilization of cellulases on magnetic nanoparticles, especially magnetite nanoparticles, has been the main approach studied to make this enzyme, economically and industrially, more attractive. However, magnetite nanoparticles tend to agglomerate, are very reactive and easily oxidized in air, which has strong impact on their useful life. Thus, it is very important to provide proper surface coating to avoid the mentioned problems. This study aimed to investigate the immobilization of cellulase on magnetic nanoparticles encapsulated in polymeric nanospheres. The support was characterized in terms of morphology, average diameter, magnetic behavior and thermal decomposition analyses. The polymer nanospheres containing encapsulated magnetic nanoparticles showed superparamagnetic behavior and intensity average diameter about 150 nm. Immobilized cellulase exhibited broader temperature stability than in the free form and great reusability capacity, 69% of the initial enzyme activity was maintained after eight cycles of use. The magnetic support showed potential for cellulase immobilization and allowed fast and easy biocatalyst recovery through a single magnet.

Immobilization of hazardous and radioactive waste into glass structures

International Nuclear Information System (INIS)

Wicks, G.G.

1997-01-01

As a result of more than three decades of international research, glass has emerged as the material of choice for immobilization of a wide range of potentially hazardous radioactive and non-radioactive materials. The ability of glass structures to incorporate and then immobilize many different elements into durable, high integrity, waste glass products is a direct function of the unique random network structure of the glassy state. Every major country involved with long-term management of high-level radioactive waste (HLW) has either selected or is considering glass as the matrix of choice for immobilizing and ultimately, disposing of the potentially hazardous, high-level radioactive material. There are many reasons why glass is preferred. Among the most important considerations are the ability of glass structures to accommodate and immobilize the many different types of radionuclides present in HLW, and to produce a product that not only has excellent technical properties, but also possesses good processing features. Good processability allows the glass to be fabricated with relative ease even under difficult remote-handling conditions necessary for vitrification of highly radioactive material. The single most important property of the waste glass produced is its ability to retain hazardous species within the glass structure and this is reflected by its excellent chemical durability and corrosion resistance to a wide range of environmental conditions. In addition to immobilization of HLW glass matrices are also being considered for isolation of many other types of hazardous materials, both radioactive as well as nonradioactive. This includes vitrification of various actinides resulting from clean-up operations and the legacy of the cold war, as well as possible immobilization of weapons grade plutonium resulting from disarmament activities. Other types of wastes being considered for immobilization into glasses include transuranic wastes, mixed wastes, contaminated

Flow synthesis of phenylserine using threonine aldolase (TA) immobilized on Eupergit support

NARCIS (Netherlands)

Tibhe, J.; Fu, Hui; Noel, T.; Wang, Q.; Meuldijk, J.; Hessel, V.

2013-01-01

Threonine aldolase (TA) from Thermotoga maritima was immobilized on Eupergit support by both a direct and an indirect method. The incubation time for the direct immobilization method was optimized for the highest amount of enzyme on the support. By introducing the immobilized TA in a packed-bed

omega-Amino acid:pyruvate transaminase from Alcaligenes denitrificans Y2k-2: a new catalyst for kinetic resolution of beta-amino acids and amines.

Science.gov (United States)

Yun, Hyungdon; Lim, Seongyop; Cho, Byung-Kwan; Kim, Byung-Gee

2004-04-01

Alcaligenes denitrificans Y2k-2 was obtained by selective enrichment followed by screening from soil samples, which showed omega-amino acid:pyruvate transaminase activity, to kinetically resolve aliphatic beta-amino acid, and the corresponding structural gene (aptA) was cloned. The gene was functionally expressed in Escherichia coli BL21 by using an isopropyl-beta-D-thiogalactopyranoside (IPTG)-inducible pET expression system (9.6 U/mg), and the recombinant AptA was purified to show a specific activity of 77.2 U/mg for L-beta-amino-n-butyric acid (L-beta-ABA). The enzyme converts various beta-amino acids and amines to the corresponding beta-keto acids and ketones by using pyruvate as an amine acceptor. The apparent K(m) and V(max) for L-beta-ABA were 56 mM and 500 U/mg, respectively, in the presence of 10 mM pyruvate. In the presence of 10 mM L-beta-ABA, the apparent K(m) and V(max) for pyruvate were 11 mM and 370 U/mg, respectively. The enzyme exhibits high stereoselectivity (E > 80) in the kinetic resolution of 50 mM D,L-beta-ABA, producing optically pure D-beta-ABA (99% enantiomeric excess) with 53% conversion.

ω-Amino Acid:Pyruvate Transaminase from Alcaligenes denitrificans Y2k-2: a New Catalyst for Kinetic Resolution of β-Amino Acids and Amines

Science.gov (United States)

Yun, Hyungdon; Lim, Seongyop; Cho, Byung-Kwan; Kim, Byung-Gee

2004-01-01

Alcaligenes denitrificans Y2k-2 was obtained by selective enrichment followed by screening from soil samples, which showed ω-amino acid:pyruvate transaminase activity, to kinetically resolve aliphatic β-amino acid, and the corresponding structural gene (aptA) was cloned. The gene was functionally expressed in Escherichia coli BL21 by using an isopropyl-β-d-thiogalactopyranoside (IPTG)-inducible pET expression system (9.6 U/mg), and the recombinant AptA was purified to show a specific activity of 77.2 U/mg for l-β-amino-n-butyric acid (l-β-ABA). The enzyme converts various β-amino acids and amines to the corresponding β-keto acids and ketones by using pyruvate as an amine acceptor. The apparent Km and Vmax for l-β-ABA were 56 mM and 500 U/mg, respectively, in the presence of 10 mM pyruvate. In the presence of 10 mM l-β-ABA, the apparent Km and Vmax for pyruvate were 11 mM and 370 U/mg, respectively. The enzyme exhibits high stereoselectivity (E > 80) in the kinetic resolution of 50 mM d,l-β-ABA, producing optically pure d-β-ABA (99% enantiomeric excess) with 53% conversion. PMID:15066855

Influences of apolipoprotein E on soluble and heparin-immobilized hepatic lipase

International Nuclear Information System (INIS)

Landis, B.A.; Rotolo, F.S.; Meyers, W.C.; Clark, A.B.; Quarfordt, S.H.

1987-01-01

The effect of human apolipoprotein E (apoE), either alone or in combination with apoC, on the lipolysis of a radiolabeled triglyceride emulsion was studied with hepatic lipase in solution and immobilized on heparin-Sepharose. The soluble hepatic lipase was inhibited, whereas the heparin-immobilized lipase was stimulated by apoE. This stimulation was attenuated by combining apoE with either apoC-II or C-III. The heparin-immobilized lipase demonstrated much less lipolysis of the zwitterionic phosphatidylcholine-stabilized triglyceride emulsion than did the soluble enzyme. This difference was less when the emulsion was stabilized by a nonionic detergent. apoE inhibited lipase activity when assayed under conditions (0.4 M NaCl) of bound enzyme and unbound substrate. Increasing the emulsion apoE content beyond optimum inhibited lipolysis by the immobilized enzyme. Kinetic analysis of phosphatidylcholine-stabilized triglyceride emulsions revealed a significant decrease in immobilized enzyme K/sub m/ and an increase in V/sub max/ when the emulsion was supplemented with apoE. Distributing the immobilized lipase in clustered aggregates produced more lipolysis than when the same enzyme content was uniformly bound

Synthesis and immobilization of polystyreneb-polyvinyltriethoxysilane micelles

KAUST Repository

Zhu, Saisai

2018-01-31

Diblock copolymers polystyrene-block-polyvinyltriethoxysilane (PS-b-PVTES) were synthesized via atom transfer radical polymerization (ATRP), which self-assembled into spherical micelles in solvent of THF-methanol mixtures. The self-assembled micelles were immobilized by cross-linking reaction of VTES in a shell layer of micelles. The chemical structures of block copolymers and morphology of micelles were characterized in detail. It was found that the size of immobilized micelles was strongly affected by the copolymer concentration, composition of mixture solvent, and block ratios.

Simple traction-immobilization device for CT scanners

International Nuclear Information System (INIS)

Robertson, J.; Federle, M.P.

1983-01-01

Successful computed tomographic (CT) scanning of acutely ill or traumatized patients often requires immobilization or traction of the extremities. Existing medical appliances and external fixation devices often are cumbersome, produce technical artifacts, or are uncomfortable for patients. This paper describes a traction-immobilization device that overcomes many of these difficulties. The authors have used this device successfully in several hundred cases and found that it markedly facilitated patient comfort and throughput. Construction is simple and inexpensive, using materials available in most hardware stores

Potential Applications of Immobilized β-Galactosidase in Food Processing Industries

Directory of Open Access Journals (Sweden)

Parmjit S. Panesar

2010-01-01

Full Text Available The enzyme β-galactosidase can be obtained from a wide variety of sources such as microorganisms, plants, and animals. The use of β-galactosidase for the hydrolysis of lactose in milk and whey is one of the promising enzymatic applications in food and dairy processing industries. The enzyme can be used in either soluble or immobilized forms but the soluble enzyme can be used only for batch processes and the immobilized form has the advantage of being used in batch wise as well as in continuous operation. Immobilization has been found to be convenient method to make enzyme thermostable and to prevent the loss of enzyme activity. This review has been focused on the different types of techniques used for the immobilization of β-galactosidase and its potential applications in food industry.

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

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

Thrombin immobilization to methacrylic acid grafted poly(3-hydroxybutyrate) and its in vitro application.

Science.gov (United States)

Akkaya, Alper; Pazarlioglu, Nurdan

2013-01-01

Poly(3-hydroxybutyrate) is nontoxic and biodegradable, with good biocompatibility and potential support for long-term implants. For this reason, it is a good support for enzyme immobilization. Enzyme immobilization could not be done directly because poly(3-hydroxybutyrate) has no functional groups. Therefore, modification should be done for enzyme immobilization. In this study, methacrylic acid was graft polymerized to poly(3-hydroxybutyrate) and thrombin was immobilized to polymethacrylic acid grafted poly(3-hydroxybutyrate). In fact, graft polymerization of methacrylic acid to poly(3-hydroxybutyrate) and thrombin immobilization was a model study. Biomolecule immobilized poly(3-hydroxybutyrate) could be used as an implant. Thrombin was selected as a biomolecule for this model study and it was immobilized to methacrylic acid grafted poly(3-hydroxybutyrate). Then the developed product was used to stop bleeding.

Tendon collagen synthesis declines with immobilization in elderly humans

DEFF Research Database (Denmark)

Dideriksen, Kasper; Boesen, Anders P; Reitelseder, Søren

2017-01-01

-80 yr) were randomly assigned to NSAIDs (ibuprofen 1,200 mg/day; Ibu) or placebo (Plc). One lower limb was immobilized in a cast for 2 wk and retrained for 6 wk. Tendon collagen protein synthesis, mechanical properties, size, expression of genes related to collagen turnover and remodeling, and signal...... intensity (from magnetic resonance imaging) were investigated. Tendon collagen synthesis decreased (P ... immobilization in both groups, whereas scleraxis mRNA decreased with inactivity in the Plc group only (P collagen protein synthesis decreased after 2 wk of immobilization, whereas tendon stiffness and modulus were only marginally reduced, and NSAIDs had no influence upon this...

Strength of interactions between immobilized dye molecules and sol-gel matrices.

Science.gov (United States)

Ismail, Fanya; Schoenleber, Monika; Mansour, Rolan; Bastani, Behnam; Fielden, Peter; Goddard, Nicholas J

2011-02-21

In this paper we present a new theory to re-examine the immobilization technique of dye doped sol-gel films, define the strength and types of possible bonds between the immobilized molecule and sol-gel glass, and show that the immobilized molecule is not free inside the pores as was previously thought. Immobilizing three different pH sensitive dyes with different size and functional groups inside the same sol-gel films revealed important information about the nature of the interaction between the doped molecule and the sol-gel matrix. The samples were characterized by means of ultraviolet-visible spectrophotometer (UV-VIS), thermal gravimetric analysis (TGA), mercury porosimetry (MP), nuclear magnetic resonance spectroscopy ((29)Si NMR) and field-emission environmental scanning electron microscopy (ESEM-FEG). It was found that the doped molecule itself has a great effect on the strength and types of the bonds. A number of factors were identified, such as number and types of the functional groups, overall charge, size, pK(a) and number of the silanol groups which surround the immobilized molecule. These results were confirmed by the successful immobilization of bromocresol green (BCG) after a completely polymerized sol-gel was made. The sol-gel consisted of 50% tetraethoxysilane (TEOS) and 50% methyltriethoxysilane (MTEOS) (w/w). Moreover, the effect of the immobilized molecule on the structure of the sol-gel was studied by means of a leaky waveguide (LW) mode for doped films made before and after polymerization of the sol-gel.

Properties of Immobilized Candida antarctica Lipase B on Highly Macroporous Copolymer

International Nuclear Information System (INIS)

Handayani, N.; Achmad, S.; Wahyuningrum, D.

2011-01-01

In spite of their excellent catalytic properties, enzymes should be improved before their implementation both in industrial and laboratorium scales. Immobilization of enzyme is one of the ways to improve their properties. Candida antarctica lipase B (Cal-B) has been reported in numerous publications to be a particularly useful enzyme catalizing in many type of reaction including regio- and enantio- synthesis. For this case, cross-linking of immobilized Cal-B with 1,2,7,8 diepoxy octane is one of methods that proved significantly more stable from denaturation by heat, organic solvents, and proteolysis than lyophilized powder or soluble enzymes. More over, the aim of this procedure is to improve the activity and reusability of lipase. Enzyme kinetics test was carried out by transesterification reaction between 4-nitrophenyl acetate (pNPA) and methanol by varying substrate concentrations, and the result is immobilized enzymes follows the Michaelis-Menten models and their activity is match with previous experiment. Based on the V max values, the immobilized enzymes showed higher activity than the free enzyme. Cross-linking of immobilized lipase indicate that cross-linking by lower concentration of cross-linker, FIC (immobilized lipase that was incubated for 24 h) gave the highest activity and cross-linking by higher concentration of cross-linker, PIC (immobilized lipase that was incubated for 2 h) gives the highest activity. However, pore size and saturation level influenced their activity. (author)

Preliminary assessment of modified borosilicate glasses for chromium and ruthenium immobilization

Energy Technology Data Exchange (ETDEWEB)

Farid, Osama M. [Reactors Department, Nuclear Research Center, Atomic Energy Authority of Egypt, P.O. 13759, Inshas, Cairo (Egypt); Centre of Nuclear Engineering (CNE), Department of Materials, Imperial College London, London, SW7 2BP (United Kingdom); Abdel Rahman, R.O., E-mail: alaarehab@yahoo.com [Hot Laboratory Center, Atomic Energy Authority of Egypt, P.O. 13759, Inshas, Cairo (Egypt)

2017-01-15

The feasibility of using modified alkali borosilicate glasses for ruthenium and chromium immobilization is preliminary assessed by investigating the immobilization system structure under normal conditions. Within this context, reference alkali borosilicate, and simulated Magnox-modified glasses were prepared and studied. The results indicate that ruthenium is immobilized in the vitreous structure as encapsulated RuO{sub 2} crystallites that act as seeds for heterogeneous nucleation of other crystalline phases. The presence of Zn, as modifier, has contributed to chromium immobilization in zincochromite spinel structure, whereas Ca is accommodated in the vitreous structure. Immobilization performance was evaluated by conducting conservative static leach test and studying the leached glass. Leached glass morphology was altered, where near surface reference glass is leached over 400 nm and simulated Magnox-modified sample is altered over 300 nm. Normalized release rates are within normal range for borosilicate material. For simulated Magnox-modified sample, Ca and alkali structural element, i.e. Na and Li, are leached via ion-exchange reaction. The ion-exchanged fraction equals 1.06 × 10{sup −8} mol/m{sup 2} s and chromium has slightly lower normalized release rate value than ruthenium. - Highlights: • The presence of modifiers and waste oxides led to localized de-vitrification. • Ruthenium is encapsulated within the vitreous glass network as RuO{sub 2} crystals. • Chromium is immobilized within the zincochromite spinel structure. • Pitting and cracks induced by leaching did not affect the immobilization performance.

Fluidized Bed Steam Reforming For Treatment And Immobilization Of Low-Activity Waste

International Nuclear Information System (INIS)

Hewitt, W.M.

2011-01-01

This report is one of four reports written to provide background information regarding immobilization technologies remaining under consideration for supplemental immobilization of Hanford's low-activity waste. This paper provides the reader a general understanding of fluidized bed steam reforming and its possible application to treat and immobilize Hanford low-activity waste.

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

Energy Technology Data Exchange (ETDEWEB)

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

2014-07-01

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

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

International Nuclear Information System (INIS)

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

2014-01-01

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

Radiation Synthesis of Nanogel for Bioactives Immobilization

International Nuclear Information System (INIS)

Hamzah, M.Y.

2009-01-01

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)

Radiation Synthesis of Nanogel for Bioactives Immobilization

Energy Technology Data Exchange (ETDEWEB)

Hamzah, M. Y. [Polymer Modification Group, Malaysian Nuclear Agency, Bangi (Malaysia)

2009-07-01

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)

A disposal centre for immobilized nuclear waste

International Nuclear Information System (INIS)

1980-02-01

This report describes a conceptual design of a disposal centre for immobilized nuclear waste. The surface facilities consist of plants for the preparation of steel cylinders containing nuclear waste immobilized in glass, shaft headframe buildings and all necessary support facilities. The underground disposal vault is located on one level at a depth of 1000 m. The waste cylinders are emplaced into boreholes in the tunnel floors. All surface and subsurface facilities are described, operations and schedules are summarized, and cost estimates and manpower requirements are given. (auth)

Phospholipid-sepiolite biomimetic interfaces for the immobilization of enzymes.

Science.gov (United States)

Wicklein, Bernd; Darder, Margarita; Aranda, Pilar; Ruiz-Hitzky, Eduardo

2011-11-01

Biomimetic interfaces based on phosphatidylcholine (PC) assembled to the natural silicate sepiolite were prepared for the stable immobilization of the urease and cholesterol oxidase enzymes. This is an important issue in practical advanced applications such as biocatalysis or biosensing. The supported lipid bilayer (BL-PC), prepared from PC adsorption, was used for immobilization of enzymes and the resulting biomimetic systems were compared to several other supported layers including a lipid monolayer (ML-PC), a mixed phosphatidylcholine/octyl-galactoside layer (PC-OGal), a cetyltrimethylammonium monolayer (CTA), and also to the bare sepiolite surface. Interfacial characteristics of these layers were investigated with a focus on layer packing density, hydrophilicity/hydrophobicity, and surface charge, which are being considered as key points for enzyme immobilization and stabilization of their biological activity. Cytoplasmic urease and membrane-bound cholesterol oxidase, which served as model enzymes, were immobilized on the different PC-based hybrid materials to probe their biomimetic character. Enzymatic activity was assessed by cyclic voltammetry and UV-vis spectrophotometry. The resulting enzyme/bio-organoclay hybrids were applied as active phase of a voltammetric urea biosensor and cholesterol bioreactor, respectively. Urease supported on sepiolite/BL-PC proved to maintain its enzymatic activity over several months while immobilized cholesterol oxidase demonstrated high reusability as biocatalyst. The results emphasize the good preservation of bioactivity due to the accommodation of the enzymatic system within the biomimetic lipid interface on sepiolite.

Ethanol production by immobilized cells with forced substrate supply

Energy Technology Data Exchange (ETDEWEB)

Mitani, Y.; Nishizawa, Y.; Nagai, S.

1984-01-01

Ethanol fermentation by a forced substrate supply into an immobilized cell layer was carried out to increase the ethanol production rate and to eliminate the diffusion dependency of substrate supply in an ordinary immobilized cell reaction. Saccharomyces cerevisiae IFO 2347 was immobilized in a mixture of k-carrageenan, locust bean gum, and celite (2: 0.5: 40 wt/vol %). A glucose minimal medium was fed into the immobilized cell layer (5 to 22 mm in thickness) at retention times between 0.6 and 2.8 h under pressure. The stable ethanol fermentation could be maintained for more than 3 weeks with an ethanol yield of 0.48 g ethanol/g glucose and ethanol productivity of 63 g.(l gel)/sup -1/.h/sup -1/ at a retention time of 1.5 h. The yeast cells were well distributed through the gel layer with a vertical gradient, and an average cell density was ca. 8.0 X 10/sup 9/ cells/ml gel, 4-fold higher than that of ordinary immobilized cells. A small filter press reactor was constructed to examine the applicability of ethanol fermentation with this forced substrate supply. The operation could be continued for a month at a retention time of 2 h yielding 96 g/l of ethanol from 200 g/l of glucose. 6 references, 5 figures, 3 tables.

Remote material handling in the Plutonium Immobilization Project. Revision 1

International Nuclear Information System (INIS)

Brault, J.R.

2000-01-01

With the downsizing of the US and Russian nuclear stockpiles, large quantities of weapons-usable plutonium in the US are being declared excess and will be disposed of by the Department of Energy Fissile Materials Disposition Program. To implement this program, DOE has selected the Savannah River Site (SRS) for the construction and operation of three new facilities: pit disassembly and conversion; mixed oxide fuel fabrication; and plutonium immobilization. The Plutonium Immobilization Project (PIP) will immobilize a portion of the excess plutonium in a hybrid ceramic and glass form containing high level waste for eventual disposal in a geologic repository. The PIP is divided into three distinct operating areas: Plutonium Conversion, First Stage Immobilization, and Second Stage Immobilization. Processing technology for the PIP is being developed jointly by the Lawrence Livermore National Laboratory and Westinghouse Savannah River Company. This paper will discuss development of the automated unpacking and sorting operations in the conversion area, and the automated puck and tray handling operations in the first stage immobilization area. Due to the high radiation levels and toxicity of the materials to be disposed of, the PIP will utilize automated equipment in a contained (glovebox) facility. Most operations involving plutonium-bearing materials will be performed remotely, separating personnel from the radiation source. Source term materials will be removed from the operations during maintenance. Maintenance will then be performed hands on within the containment using glove ports

Bulk Vitrification Technology For The Treatment And Immobilization Of Low-Activity Waste

International Nuclear Information System (INIS)

Ard, K.E.

2011-01-01

This report is one of four reports written to provide background information regarding immobilization technologies under consideration for supplemental immobilization of Hanford's low-activity waste. This paper is intended to provide the reader with general understanding of Bulk Vitrification and how it might be applied to immobilization of Hanford's low-activity waste.

FLUIDIZED BED STEAM REFORMING FOR TREATMENT AND IMMOBILIZATION OF LOW-ACTIVITY WASTE

Energy Technology Data Exchange (ETDEWEB)

HEWITT WM

2011-04-08

This report is one of four reports written to provide background information regarding immobilization technologies remaining under consideration for supplemental immobilization of Hanford's low-activity waste. This paper provides the reader a general understanding of fluidized bed steam reforming and its possible application to treat and immobilize Hanford low-activity waste.

Graphene immobilized enzyme/polyethersulfone mixed matrix membrane: Enhanced antibacterial, permeable and mechanical properties

International Nuclear Information System (INIS)

Duan, Linlin; Wang, Yuanming; Zhang, Yatao; Liu, Jindun

2015-01-01

Graphical abstract: - Highlights: • Lysozyme was immobilized on the surface of graphene oxide (GO) and reduced GO (RGO). • The novel hybrid membranes based on lysozyme and graphene were fabricated firstly. • These membranes showed good antibacterial and mechanical performance. - Abstract: Enzyme immobilization has been developed to address lots of issues of free enzyme, such as instability, low activity and difficult to retain. In this study, graphene was used as an ideal carrier for lysozyme immobilization, including graphene oxide (GO) immobilized lysozyme (GO-Ly) and chemically reduced graphene oxide (CRGO) immobilized lysozyme (CRGO-Ly). Herein, lysozyme as a bio-antibacterial agent has excellent antibacterial performance and the products of its catalysis are safety and nontoxic. Then the immobilized lysozyme materials were blended into polyethersulfone (PES) casting solution to prepare PES ultrafiltration membrane via phase inversion method. GO and CRGO were characterized by Fourier transform infrared spectroscopy (FTIR), Ultraviolet–visible spectrum (UV), X-ray diffraction (XRD), and transmission electron microscopy (TEM) and the immobilized lysozyme composites were observed by fluorescent microscopy. The results revealed that GO and CRGO were successfully synthesized and lysozyme was immobilized on their surfaces. The morphology, hydrophilicity, mechanical properties, separation properties and antibacterial activity of the hybrid membranes were characterized in detail. The hydrophilicity, water flux and mechanical strength of the hybrid membranes were significantly enhanced after adding the immobilized lysozyme. In the antibacterial experiment, the hybrid membranes exhibited an effective antibacterial performance against Escherichia coli (E. coli).

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

International Nuclear Information System (INIS)

Oktay, Burcu; Demir, Serap; Kayaman-Apohan, Nilhan

2015-01-01

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

Nanoclays for Lipase Immobilization: Biocatalyst Characterization and Activity in Polyester Synthesis

Directory of Open Access Journals (Sweden)

Hale Öztürk

2016-12-01

Full Text Available The immobilization of Candida antarctica lipase B (CALB was performed by physical adsorption on both neat and organo-modified forms of sepiolite and montmorillonite. The influence of different parameters, e.g., solvent, enzyme loading, cross-linking, and type of clay support, on immobilization efficiency and catalyst hydrolytic activity has been investigated. The highest hydrolytic activities were obtained for CALB immobilized on organo-modified clay minerals, highlighting the beneficial effect of organo-modification. The esterification activity of these CALB/organoclay catalysts was also tested in the ring-opening polymerization of ε-caprolactone. The polymerization kinetics observed for clay-immobilized catalysts confirmed that CALB adsorbed on organo-modified montmorillonite (CALB/MMTMOD was the highest-performing catalytic system.

Herbaceous plants as filters: Immobilization of particulates along urban street corridors

International Nuclear Information System (INIS)

Weber, Frauke; Kowarik, Ingo; Säumel, Ina

2014-01-01

Among air pollutants, particulate matter (PM) is considered to be the most serious threat to human health. Plants provide ecosystem services in urban areas, including reducing levels of PM by providing a surface for deposition and immobilization. While previous studies have mostly addressed woody species, we focus on herbaceous roadside vegetation and assess the role of species traits such as leaf surface roughness or hairiness for the immobilization of PM. We found that PM deposition patterns on plant surfaces reflect site-specific traffic densities and that strong differences in particulate deposition are present among species. The amount of immobilized PM differed according to particle type and size and was related to specific plant species traits. Our study suggests that herbaceous vegetation immobilizes a significant amount of the air pollutants relevant to human health and that increasing biodiversity of roadside vegetation supports air filtration and thus healthier conditions along street corridors. -- Highlights: • We assessed PM immobilization by common urban herbaceous roadside species. • PM deposition was related to traffic density and plant species traits. • Amount of PM deposited differed according to particle type and size. • Increasing biodiversity of roadside vegetation supports air filtration. -- Herbaceous urban roadside vegetation immobilizes particulate matter relevant to human health, thus supporting healthier conditions next to busy roads

Availability and improvement of a vacuum-type immobilization device in pediatric CT

International Nuclear Information System (INIS)

Tani, Shoji; Mizuno, Naoto; Abe, Syuji

2002-01-01

The essential factors for an immobilization device in pediatric CT are absence of artifacts, safety, no disturbance of the patient's sedation, and ease of handling. We evaluated the suitability of a commercially available vacuum-type immobilization device designed for radiation therapy (Vac-Lok) that meets these requisites. There were no artifacts in scans of the water phantom. The device easily immobilized the patient, was quick to release, and was superior to previous immobilization systems, according to replies to a questionnaire administered to physicians, technologists, and nurses. Schedule delays were reduced by using this device to examine sedated patients (up to 1 year of age). Despite these advantages, the device was too small to immobilize both extremities together when examining older patients. In order to overcome this problem, we invented a special immobilization device for pediatric CT. The new device could be applied to taller patients, up to 85 cm in height (the average height of 2-year-old infants), and was able to contribute to efficient utilization of the examination room. (author)

Evaluation of protein immobilization capacity on various carbon nanotube embedded hydrogel biomaterials

Energy Technology Data Exchange (ETDEWEB)

Derkus, Burak, E-mail: burakderkus@gmail.com; Emregul, Kaan Cebesoy; Emregul, Emel

2015-11-01

This study investigates effective immobilization of proteins, an important procedure in many fields of bioengineering and medicine, using various biomaterials. Gelatin, alginate and chitosan were chosen as polymeric carriers, and applied in both their composites and nanocomposite forms in combination with carbon nanotubes (CNTs). The prepared nano/composite structures were characterized using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TG) and contact angle analysis (CA). Electrochemical impedance spectroscopy analysis revealed gelatin composites in general to exhibit better immobilization performance relative to the native gelatin which can be attributed to enhanced film morphologies of the composite structures. Moreover, superior immobilization efficiencies were obtained with the addition of carbon nanotubes, due to their conducting and surface enhancement features, especially in the gelatin–chitosan structures due to the presence of structural active groups. - Highlights: • Various nanocomposite biomaterials were developed for efficient immobilization of proteins. • CNTs enhance the immobilization efficiency owing to their conducting and surface enhancement features. • Gelatin–chitosan–CNTs structure is promising immobilization matrix thanks to its effective CNTs binding capacity.

External rotation immobilization for primary shoulder dislocation: a randomized controlled trial.

Science.gov (United States)

Whelan, Daniel B; Litchfield, Robert; Wambolt, Elizabeth; Dainty, Katie N

2014-08-01

The traditional treatment for primary anterior shoulder dislocations has been immobilization in a sling with the arm in a position of adduction and internal rotation. However, recent basic science and clinical data have suggested recurrent instability may be reduced with immobilization in external rotation after primary shoulder dislocation. We performed a randomized controlled trial to compare the (1) frequency of recurrent instability and (2) disease-specific quality-of-life scores after treatment of first-time shoulder dislocation using either immobilization in external rotation or immobilization in internal rotation in a group of young patients. Sixty patients younger than 35 years of age with primary, traumatic, anterior shoulder dislocations were randomized (concealed, computer-generated) to immobilization with either an internal rotation sling (n = 29) or an external rotation brace (n = 31) at a mean of 4 days after closed reduction (range, 1-7 days). Patients with large bony lesions or polytrauma were excluded. The two groups were similar at baseline. Both groups were immobilized for 4 weeks with identical therapy protocols thereafter. Blinded assessments were completed by independent observers for a minimum of 12 months (mean, 25 months; range, 12-43 months). Recurrent instability was defined as a second documented anterior dislocation or multiple episodes of shoulder subluxation severe enough for the patient to request surgical stabilization. Validated disease-specific quality-of-life data (Western Ontario Shoulder Instability index [WOSI], American Shoulder and Elbow Surgeons evaluation [ASES]) were also collected. Ten patients (17%, five from each group) were lost to followup. Reported compliance with immobilization in both groups was excellent (80%). With the numbers available, there was no difference in the rate of recurrent instability between groups: 10 of 27 patients (37%) with the external rotation brace versus 10 of 25 patients (40%) with the

Immobilization of urease on grafted starch by radiation method

International Nuclear Information System (INIS)

Nguyenanh Dung; Nguyendinh Huyen

1995-01-01

The acrylamide was grafted by radiation onto starch which is a kind of polymeric biomaterial. The urease was immobilized on the grafted starch. Some experiments to observe the quantitative relationships between the percent graft and the activity of immobilized enzyme were determined. The enzyme activity was maintained by more than seven batch enzyme reactions. (author)

Immobilization of oxidases and their analytical applications

International Nuclear Information System (INIS)

Yasinzai, M.

2007-01-01

Immobilized enzymes are replacing their soluble counter-parts in nearly every field of application. These enzyme modifications have evolved from a research curiosity into an entire branch of Biotechnology. An immobilization method for flavin containing oxidases and their use in flow injection system is described. An electrochemical detector for H/sub 2/O/sub 2/ is assembled which is used effectively for the determination of glucose using more common glucose oxidase and the simultaneous determination of sugars. The combination of oxidases with hydrolases have been used for the determination of maltose and starch. (author)

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.

Polyketone polymer: a new support for direct enzyme immobilization.

Science.gov (United States)

Agostinelli, E; Belli, F; Tempera, G; Mura, A; Floris, G; Toniolo, L; Vavasori, A; Fabris, S; Momo, F; Stevanato, R

2007-01-20

Polyketone polymer -[-CO-CH(2)-CH(2)-](n)-, obtained by copolymerization of ethene and carbon monoxide, is utilized for immobilization of three different enzymes, one peroxidase from horseradish (HRP) and two amine oxidases, from bovine serum (BSAO) and lentil seedlings (LSAO). The easy immobilization procedure is carried out in diluted buffer, at pH 7.0 and 3 degrees C, gently mixing the proteins with the polymer. No bifunctional reagents and spacer arms are required for the immobilization, which occurs exclusively via a large number of hydrogen bonds between the carbonyl groups of the polymer and the -NH groups of the polypeptidic chain. Experiments demonstrate a high linking capacity of polymer for BSAO and an extraordinary strong linkage for LSAO. Moreover, activity measurements demonstrate that immobilized LSAO totally retains the catalytic characteristics of the free enzyme, where only a limited increase of K(M) value is observed. Finally, the HRP-activated polymer is successfully used as active packed bed of an enzymatic reactor for continuous flow conversion and flow injection analysis of hydrogen peroxide containing solutions.

Applications of polymers for biomolecule immobilization in electrochemical biosensors

International Nuclear Information System (INIS)

Teles, F.R.R.; Fonseca, L.P.

2008-01-01

Polymers are becoming inseparable from biomolecule immobilization strategies and biosensor platforms. Their original role as electrical insulators has been progressively substituted by their electrical conductive abilities, which opens a new and broad scope of applications. In addition, recent advances in diagnostic chips and microfluidic systems, together with the requirements of mass-production technologies, have raised the need to replace glass by polymeric materials, which are more suitable for production through simple manufacturing processes. Conducting polymers (CPs), in particular, are especially amenable for electrochemical biosensor development for providing biomolecule immobilization and for rapid electron transfer. It is expected that the combination of known polymer substrates, but also new transducing and biocompatible interfaces, with nanobiotechnological structures, like nanoparticles, carbon nanotubes (CNTs) and nanoengineered 'smart' polymers, may generate composites with new and interesting properties, providing higher sensitivity and stability of the immobilized molecules, thus constituting the basis for new and improved analytical devices for biomedical and other applications. This review covers the state-of-the-art and main novelties about the use of polymers for immobilization of biomolecules in electrochemical biosensor platforms

Immobilization of trypsin on sub-micron skeletal polymer monolith

Energy Technology Data Exchange (ETDEWEB)

Yao Chunhe [Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Graduate School, Chinese Academy of Sciences, Beijing 100049 (China); Qi Li, E-mail: qili@iccas.ac.cn [Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Hu Wenbin [Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Graduate School, Chinese Academy of Sciences, Beijing 100049 (China); Wang Fuyi [Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Yang Gengliang [College of Pharmacy, Hebei University, Baoding 071002 (China)

2011-04-29

A new kind of immobilized trypsin reactor based on sub-micron skeletal polymer monolith has been developed. Covalent immobilization of trypsin on this support was performed using the epoxide functional groups in either a one- or a multi-step reaction. The proteolytic activity of the immobilized trypsin was measured by monitoring the formation of N-{alpha}-benzoyl-L-arginine (BA) which is the digestion product of a substrate N-{alpha}-benzoyl-L-arginine ethyl ester (BAEE). Results showed that the digestion speed was about 300 times faster than that performed in free solution. The performance of such an enzyme reactor was further demonstrated by digesting protein myoglobin. It has been found that the protein digestion could be achieved in 88 s at 30 deg. C, which is comparable to 24 h digestion in solution at 37 {sup o}C. Furthermore, the immobilized trypsin exhibits increased stability even after continuous use compared to that in free solution. The present monolithic enzyme-reactor provides a promising platform for the proteomic research.

Poly(acrylonitrile)chitosan composite membranes for urease immobilization.

Science.gov (United States)

Gabrovska, Katya; Georgieva, Aneliya; Godjevargova, Tzonka; Stoilova, Olya; Manolova, Nevena

2007-05-10

(Poly)acrylonitrile/chitosan (PANCHI) composite membranes were prepared. The chitosan layer was deposited on the surface as well as on the pore walls of the base membrane. This resulted in the reduction of the pore size of the membrane and in an increase of their hydrophilicity. The pore structure of PAN and PANCHI membranes were determined by TEM and SEM analyses. It was found that the average size of the pore under a selective layer base PAN membrane is 7 microm, while the membrane coated with 0.25% chitosan shows a reduced pore size--small or equal to 5 microm and with 0.35% chitosan--about 4 microm. The amounts of the functional groups, the degree of hydrophilicity and transport characteristics of PAN/Chitosan composite membranes were determined. Urease was covalently immobilized onto all kinds of PAN/chitosan composite membranes using glutaraldehyde. Both the amount of bound protein and relative activity of immobilized urease were measured. The highest activity (94%) was measured for urease bound to PANCHI2 membranes (0.25% chitosan). The basic characteristics (pH(opt), pH(stability), T(opt), T(stability), heat inactivation and storage stability) of immobilized urease were determined. The obtained results show that the poly(acrylonitrile)chitosan composite membranes are suitable for enzyme immobilization.

Dose behind various immobilization and beam-modifying devices

International Nuclear Information System (INIS)

Mellenberg, David E.

1995-01-01

Purpose: To quantify the degradation of skin sparing associated with using beam modifiers such as compensators, immobilization devices, and custom blocks for high energy photon beams. Methods and Materials: The degradation of skin sparing was quantified by measuring dose build-up curves with an extrapolation chamber for 6 and 15 MV photon beams. Uniform thickness compensators made of gypsum and lead, thermoplastic mask material, immobilization cradle foam, and cerrobend custom blocks were placed in geometries that mimic relevant clinical situations. Results: Compensators, whether made of gypsum or lead, placed in the linear accelerator's wedge slot did not significantly effect the depth dose curve's build-up region. Immobilization devices such as cradle foam or thermoplastic placed in contact with the patient degrade the skin sparing expected from high energy photon beams proportional to their thickness and density. Measurements behind custom blocks show that surface and near surface doses for a blocked field are best described by build-up curves for an equivalent size open field. Conclusions: These results allow explanation and possibly prediction of skin reactions on patients in which compensators, foam immobilization cradles, thermoplastic masks, or custom blocks are used. These results also provide a baseline by which substitute materials can be evaluated

A summary of methods for conditioning and immobilizing ion-exchange resins

International Nuclear Information System (INIS)

Speranzini, R.A.; Buckley, L.P.

1983-02-01

Ion-exchange resins are used in CANDU-PHW nuclear power stations to purify heavy water in the primary heat transport (PHT) and moderator systems. Two promising techniques for conditioning spent ion-exchange resins for disposal have been evaluated: direct immobilization and incineration combined with immobilization of the ash and scrubbed off-gases. When ion-exchange resins were immobilized directly, volumes of bitumen products were about 0.75 times the volumes of untreated resin, while the volumes of cement and polyester products were 2 to 3 times larger. While incinerating the resin is an extra processing step, much smaller volumes result from the latter option. Bitumen and glass product volumes were six and ten times smaller, respectively, than the volumes of untreated resin, while cement and polyester product volumes were about one-half the volume of untreated resin. Since the releases of Cs-136 by leaching were lowest for products made by immobilization in glass, PHT resins which have high concentrations of Cs-137 should be vitrified. Moderator resins which have high concentrations of C-14 should be incinerated and the ash and C-14-contaminated scrubbing solutions should be immobilized. By pretreating such resins with calcium chloride or carbon dioxide, the C-14 present on resin could be released at temperatures below the ignition temperature of the resin. The pretreatment technique reduces the amount of inactive carbon dioxide that must be scrubbed to trap the C-14. The releases of C-14 from immobilized barium hydroxide scrubbing solution were the same as releases from immobilized resin

Immobilization and controlled release of drug using plasma polymerized thin film

Energy Technology Data Exchange (ETDEWEB)

Myung, Sung-Woon [Department of Dental Materials, School of Dentistry, MRC Center, Chosun University, 309 Pilmun-daero, Dong-gu, Gwangju (Korea, Republic of); Jung, Sang-Chul [Department of Environmental Engineering, Sunchon National University, Sunchon 540-742 (Korea, Republic of); Kim, Byung-Hoon, E-mail: kim5055@chosun.ac.kr [Department of Dental Materials, School of Dentistry, MRC Center, Chosun University, 309 Pilmun-daero, Dong-gu, Gwangju (Korea, Republic of)

2015-06-01

In this study, plasma polymerization of acrylic acid was employed to immobilize drug and control its release. Doxorubicin (DOX) was immobilized covalently on the glass surface deposited with plasma polymerized acrylic acid (PPAAc) thin film containing the carboxylic group. At first, the PPAAc thin film was coated on a glass surface at a pressure of 1.33 Pa and radio frequency (RF) discharge power of 20 W for 10 min. DOX was immobilized on the PPAAc deposition in a two environment of phosphate buffer saline (PBS) and dimethyl sulfoxide (DMSO) solutions. The DOX immobilized surface was characterized by scanning electron microscope, atomic force microscope and attenuated total reflection Fourier transform infrared spectroscopy. The DOX molecules were more immobilized in PBS than DMSO solution. The different immobilization and release profiles of DOX result from the solubility of hydrophobic DOX in aqueous and organic solutions. Second, in order to control the release of the drug, PPAAc thin film was covered over DOX dispersed layer. Different thicknesses and cross-linked PPAAc thin films by adjusting deposition time and RF discharge power were covered on the DOX layer dispersed. PPAAc thin film coated DOX layer reduced the release rate of DOX. The thickness control of plasma deposition allows controlling the release rate of drug. - Highlights: • Doxorubicin was immobilized on the surface of plasma polymerized acrylic acid thin film. • Release profile of doxorubicin was affected by aqueous and organic solutions. • Plasma polymerized acrylic acid thin film can be used to achieve controlled release.

Immobilization and controlled release of drug using plasma polymerized thin film

International Nuclear Information System (INIS)

Myung, Sung-Woon; Jung, Sang-Chul; Kim, Byung-Hoon

2015-01-01

In this study, plasma polymerization of acrylic acid was employed to immobilize drug and control its release. Doxorubicin (DOX) was immobilized covalently on the glass surface deposited with plasma polymerized acrylic acid (PPAAc) thin film containing the carboxylic group. At first, the PPAAc thin film was coated on a glass surface at a pressure of 1.33 Pa and radio frequency (RF) discharge power of 20 W for 10 min. DOX was immobilized on the PPAAc deposition in a two environment of phosphate buffer saline (PBS) and dimethyl sulfoxide (DMSO) solutions. The DOX immobilized surface was characterized by scanning electron microscope, atomic force microscope and attenuated total reflection Fourier transform infrared spectroscopy. The DOX molecules were more immobilized in PBS than DMSO solution. The different immobilization and release profiles of DOX result from the solubility of hydrophobic DOX in aqueous and organic solutions. Second, in order to control the release of the drug, PPAAc thin film was covered over DOX dispersed layer. Different thicknesses and cross-linked PPAAc thin films by adjusting deposition time and RF discharge power were covered on the DOX layer dispersed. PPAAc thin film coated DOX layer reduced the release rate of DOX. The thickness control of plasma deposition allows controlling the release rate of drug. - Highlights: • Doxorubicin was immobilized on the surface of plasma polymerized acrylic acid thin film. • Release profile of doxorubicin was affected by aqueous and organic solutions. • Plasma polymerized acrylic acid thin film can be used to achieve controlled release

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

Science.gov (United States)

Inada, Toru; Kaneko, Fuminari; Hayami, Tatsuya

2016-04-01

Kinesthetic illusions by visual stimulation (KiNVIS) enhances corticomotor excitability and activates motor association areas. The purpose of this study was to investigate the effect of KiNVIS induction on muscular output function after short-term immobilization. Thirty subjects were assigned to 3 groups: an immobilization group, with the left hand immobilized for 12h (immobilization period); an illusion group, with the left hand immobilized and additionally subjected to KiNVIS of the immobilized part during the immobilization period; and a control group with no manipulation. The maximum voluntary contraction (MVC), fluctuation of force (force fluctuation) during a force modulation task, and twitch force were measured both before (pre-test) and after (post-test) the immobilization period. Data were analyzed by performing two-way (TIME×GROUP) repeated measures ANOVA. The MVC decreased in the immobilization group only (pre-test; 37.8±6.1N, post-test; 32.8±6.9N, p<0.0005) after the immobilization period. The force fluctuation increased only in the immobilization group (pre-test; 2.19±0.54%, post-test; 2.78±0.87%, p=0.007) after the immobilization period. These results demonstrate that induction of KiNVIS prevents negative effect on MVC and force fluctuation after 12h of immobilization. Copyright © 2016 Elsevier Ltd. All rights reserved.

BULK VITRIFICATION TECHNOLOGY FOR THE TREATMENT AND IMMOBILIZATION OF LOW-ACTIVITY WASTE

Energy Technology Data Exchange (ETDEWEB)

ARD KE

2011-04-11

This report is one of four reports written to provide background information regarding immobilization technologies under consideration for supplemental immobilization of Hanford's low-activity waste. This paper is intended to provide the reader with general understanding of Bulk Vitrification and how it might be applied to immobilization of Hanford's low-activity waste.

Plasma lactate concentrations in free-ranging moose (Alces alces) immobilized with etorphine.

Science.gov (United States)

Haga, Henning A; Wenger, Sandra; Hvarnes, Silje; Os, Oystein; Rolandsen, Christer M; Solberg, Erling J

2009-11-01

To investigate plasma lactate concentrations of etorphine-immobilized moose in relation to environmental, temporal and physiological parameters. Prospective clinical study. Fourteen female and five male moose (Alces alces), estimated age range 1-7 years. The moose were darted from a helicopter with 7.5 mg etorphine per animal using projectile syringes and a dart gun. Once immobilized, the moose were approached, a venous blood sample was obtained and vital signs including pulse oximetry were recorded. Diprenorphine was administered to reverse the effects of etorphine. Timing of events, ambient temperature and snow depth were recorded. Blood samples were cooled and centrifuged before plasma was harvested and frozen. The plasma was thawed later and lactate analysed. Data were analysed using descriptive statistics and regression analysis. All animals recovered uneventfully and were alive 12 weeks after immobilization. Mean +/- SD plasma lactate was found to be 9.2 +/- 2.1 mmol L(-1). Plasma lactate concentrations were related positively to snow depth and negatively to time from induction of immobilization to blood sampling. The model that best described the variability in plasma lactate concentrations used induction time (time from firing the dart to the moose being immobilized). The second best model included induction time and snow depth. Plasma lactate concentrations in these etorphine-immobilized moose were in the range reported for other immobilized wild ruminants. Decreasing induction time, which may be related to a more profound etorphine effect, and increasing snow depth possibly may increase plasma lactate concentrations in etorphine-immobilized moose.

Immobilized enzymes in blood plasma exchangers via radiation grafting

Science.gov (United States)

Gombotz, Wayne; Hoffman, Allan; Schmer, Gottfried; Uenoyama, Satoshi

The enzyme asparaginase was immobilized onto a porous hollow polypropylene (PP) fiber blood plasma exchange device for the treatment of acute lymphocytic leukemia. The devices were first radiation grafted with polymethacrylic acid (poly(MAAc)). This introduces carboxyl groups onto the surface of the fibers. Several variables were studied in the grafting reaction including the effects of solvent type and monomer concentration. The carboxyl groups were activated with N-hydroxy succinimide (NHS) using carbodiimide chemistry. Asparaginase was then covalently immobilized on the activated surfaces. Quantitative relationships were found relating the percent graft to the amount of immobilized enzyme which was active. The enzyme reactor was tested both in vitro and in vivo using a sheep as an animal model.

Effects of immobilization and whole-body vibration on rat serum Type I collagen turnover.

Science.gov (United States)

Dönmez, Gürhan; Doral, Mahmut Nedim; Suljevic, Şenay; Sargon, Mustafa Fevzi; Bilgili, Hasan; Demirel, Haydar Ali

2016-08-01

The aim of this study was to investigate the effects of short-term, high-magnitude whole-body vibration (WBV) on serum type I collagen turnover in immobilized rats. Thirty Wistar albino rats were randomly divided into the following 5 groups: immobilization (IS), immobilization + remobilization (IR), immobilization + WBV (IV), control (C), and WBV control (CV). Immobilization was achieved by casting from the crista iliaca anterior superior to the lower part of the foot for 2 weeks. The applied WBV protocol involved a frequency of 45 Hz and amplitude of 3 mm for 7 days starting a day after the end of the immobilization period. Serum type I collagen turnover markers were measured by using ELISA kits. Serum NH2-terminal propeptide of type I collagen (PINP) levels were significantly lower in the immobilization groups (p immobilization groups. Similarly, serum COOH-terminal telopeptide of type I collagen (CTX) levels were higher in the WBV controls than their own controls (p Immobilization led to deterioration of tendon tissue, as observed by histopathological analysis with a transmission electron microscope. Although 1 week of WBV had a positive effect on type I collagen turnover in controls, it is not an efficient method for repairing tissue damage in the early stage following immobilization. Copyright © 2016 Turkish Association of Orthopaedics and Traumatology. Production and hosting by Elsevier B.V. All rights reserved.

Immobilization of urease on copper chelated EC-Tri beads and ...

African Journals Online (AJOL)

Maximum reaction rate (Vmax) and Michaelis-Menten constant (km) were determined for the free and immobilized enzymes. Various characteristics of immobilized urease such as the temperature activity curve, thermal stability, operational stability and storage stability were evaluated. The results demonstrated that triazole ...

Immobilization of fission products in phosphate ceramic waste forms

International Nuclear Information System (INIS)

Singh, D.

1996-01-01

The goal of this project is to develop and demonstrate the feasibility of a novel low-temperature solidification/stabilization (S/S) technology for immobilizing waste streams containing fission products such as cesium, strontium, and technetium in a chemically bonded phosphate ceramic. This technology can immobilize partitioned tank wastes and decontaminate waste streams containing volatile fission products

Immobilization of alpha-amylase from Bacillus circulans GRS 313 on coconut fiber.

Science.gov (United States)

Dey, Gargi; Nagpal, Varima; Banerjee, Rintu

2002-01-01

A simple and inexpensive method for immobilizing alpha-amylase from Bacillus circulans GRS 313 on coconut fiber was developed. The immobilization conditions for highest efficiency were optimized with respect to immobilization pH of 5.5, 30 degrees C, contact time of 4 h, and enzyme to support a ratio of 1:1 containing 0.12 mg/mL of protein. The catalytic properties of the immobilized enzyme were compared with that of the free enzyme. The activity of amylase adsorbed on coconut fiber was 38.7 U/g of fiber at its optimum pH of 5.7 and 48 degrees C, compared with the maximum activity of 40.2 U/mL of free enzyme at the optimum pH of 4.9 and 48 degrees C. The reutilization capacity of the immobilized enzyme was up to three cycles.

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

Science.gov (United States)

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

2005-10-01

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

Motor cortical adaptations to 2 weeks of lower limb immobilization

DEFF Research Database (Denmark)

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

was to examine the effect of 2 weeks of immobilization on corticospinal excitability using transcranial magnetic stimulation (TMS) and to investigate blood flow changes in the sensorimotor cortex during ankle movement using functional magnetic resonance imaging (fMRI). 12 healthy volunteers had the left ankle...... and foot immobilized by a cast for 2 weeks. TMS and fMRI testing was performed on 2 separate days before immobilization, on the day of cast removal and 2 weeks of recovery. fMRI was accomplished with a Siemens Trio 3T scanner and fMRI time series were obtained during both active and passive ankle movement...... in a block design alternating between movement (20s) and rest (20s). Ankle joint position, torque and the EMG activity from m. soleus and m. tibialis anterior were monitored throughout all measurements. Following immobilization maximal voluntary plantarflexion and dorsiflexion torque decreased by 15% and 22...

Continuous synthesis of glucoamylase by immobilized fungal mycelium of Aspergillus niger

Energy Technology Data Exchange (ETDEWEB)

Abraham, T.E.; Jamuna, R.; Bansilal, C.V.; Ramakrishna, S.V. (Regional Research Lab., Trivandrum (India))

1991-03-01

The extracellular glucoamylase enzyme (EC 3.2.1.3) was synthesized continuously by the immobilized mycelial fragments of A. niger. Of the several polymeric matrices attempted for immobilization k-carrageenan and alginate were found to be the most effective. However, the enzyme activity exhibited by the immobilized mycelia (I.M.) was 15-20% lower than that of free cells under batch conditions. The immobilized cells have retained nearly the same enzymatic activity (120IU/g of I.M.) for 6 repeated batches and thereafter decline in activity was noticed. An aerated packed bed reactor with I.M. was operated continuously for 360 h. The volumetric productivity of the reactor was 1600IU/L/h for 192 h and reduced to 25% in 360 h. (orig.).

Immobilization and kinetics of catalase on calcium carbonate nanoparticles attached epoxy support.

Science.gov (United States)

Preety; Hooda, Vinita

2014-01-01

A novel hybrid epoxy/nano CaCO3 composite matrix for catalase immobilization was prepared by polymerizing epoxy resin in the presence of CaCO3 nanoparticles. The hybrid support was characterized using scanning electron microscopy and Fourier transform infrared spectroscopy. Catalase was successfully immobilized onto epoxy/nano CaCO3 support with a conjugation yield of 0.67 ± 0.01 mg/cm(2) and 92.63 ± 0.80 % retention of activity. Optimum pH and optimum temperature of free and immobilized catalases were found to be 7.0 and 35 °C. The value of Km for H2O2 was higher for immobilized enzyme (31.42 mM) than native enzyme (27.73 mM). A decrease in Vmax value from 1,500 to 421.10 μmol (min mg protein)(-1) was observed after immobilization. Thermal and storage stabilities of catalase improved immensely after immobilization. Immobilized enzyme retained three times than the activity of free enzyme when kept at 75 °C for 1 h and the half-life of enzyme increased five times when stored in phosphate buffer (0.01 M, pH 7.0) at 5 °C. The enzyme could be reused 30 times without any significant loss of its initial activity. Desorption of catalase from the hybrid support was minimum at pH 7.0.

Immobilization of Mn and NH4 (+)-N from electrolytic manganese residue waste.

Science.gov (United States)

Chen, Hongliang; Liu, Renlong; Liu, Zuohua; Shu, Jiancheng; Tao, Changyuan

2016-06-01

The objective of this work was the immobilization of soluble manganese (Mn) and ammonium nitrogen (NH4 (+)-N) leached from electrolytic manganese residue (EMR). Immobilization of Mn was investigated via carbonation using carbon dioxide (CO2) and alkaline additives. NH4 (+)-N immobilization was evaluated via struvite precipitation using magnesium and phosphate sources. Results indicated that the immobilization efficiency of Mn using CO2 and quicklime (CaO) was higher than using CO2 and sodium hydroxide (NaOH). This higher efficiency was likely due to the slower release of OH(-) during CaO hydrolysis. The immobilization efficiency of Mn was >99.99 % at the CaO:EMR mass ratio of 0.05:1 for 20-min reaction time. The struvite precipitation of NH4 (+)-N was conducted in the carbonated EMR slurry and the immobilization efficiency was 89 % using MgCl2 · 6H2O + Na3PO4 · 12H2O at the Mg:P:N molar ratio of 1.5:1.5:1 for 90-min reaction time. A leaching test showed that the concentrations of Mn and NH4 (+)-N in the filtrate of the treated EMR were 0.2 and 9 mg/L, respectively. The combined immobilization of Mn and NH4 (+)-N was an effective pretreatment method in the harmless treatment of the EMR.

Enhanced Uranium Immobilization and Reduction by Geobacter sulfurreducens Biofilms

Science.gov (United States)

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

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 concentrations (up to 5 mM) of uranium, consistent with a respiratory strategy that also protected the cells from uranium toxicity. The enhanced ability of the biofilms to immobilize uranium correlated only partially with the biofilm biomass and thickness and depended greatly on the area of the biofilm exposed to the soluble contaminant. In contrast, uranium reduction depended on the expression of Geobacter conductive pili and, to a lesser extent, on the presence of the c cytochrome OmcZ in the biofilm matrix. The results support a model in which the electroactive biofilm matrix immobilizes and reduces the uranium in the top stratum. This mechanism prevents the permeation and mineralization of uranium in the cell envelope, thereby preserving essential cellular functions and enhancing the catalytic capacity of Geobacter cells to reduce uranium. Hence, the biofilms provide cells with a physically and chemically protected environment for the sustained immobilization and reduction of uranium that is of interest for the development of improved strategies for the in situ bioremediation of environments impacted by uranium contamination. PMID:25128347

Nanostructured ZnO-based biosensor: DNA immobilization and hybridization

Directory of Open Access Journals (Sweden)

Ahmed Mishaal Mohammed

2017-09-01

Full Text Available An electrochemical DNA biosensor was successfully fabricated by using (3-aminopropyl triethoxysilane (APTES with zinc oxide (ZnO nanorods synthesized using microwave-assisted chemical bath deposition method on thermally oxidized SiO2 thin films. The structural quality and morphology of the ZnO nanorods were determined by employing scanning electron microscopy (SEM and X-ray diffraction (XRD, which show a hexagonal wurtzite structure with a preferred orientation along the (101 direction. The surface of the SiO2 thin films was chemically modified with ZnO. Label-free detection DNA immobilization and hybridization were performed using potassium hexacyanoferrate with cyclic voltammetry (CV measurements. The capacitance, permittivity, and conductivity profiles of the fabricated sensor clearly indicate DNA immobilization and hybridization. Results show that the capacitance values of bare, ZnO- modified surface immobilization, and target DNA hybridization were 46×10−12F, 47×10−8F, 27μF, and 17μF, respectively, at 1Hz. The permittivity measurement increased from 3.94×103 to 251×103 and 165×103 at the frequency range of approximately 200 to 1Hz for bare and DNA immobilization and hybridization, respectively. The measured conductivity values for the bare, ZnO, immobilized, and hybridization device were 2.4×10−9, 10×10−8, 1.6×10−7, and 1.3×10−7Scm−1, respectively. Keywords: Zinc oxide, Biosensor, Capacitance, Permittivity, Conductivity

Optimization of Enzyme Co-Immobilization with Sodium Alginate and Glutaraldehyde-Activated Chitosan Beads.

Science.gov (United States)

Gür, Sinem Diken; İdil, Neslihan; Aksöz, Nilüfer

2018-02-01

In this study, two different materials-alginate and glutaraldehyde-activated chitosan beads-were used for the co-immobilization of α-amylase, protease, and pectinase. Firstly, optimization of multienzyme immobilization with Na alginate beads was carried out. Optimum Na alginate and CaCl 2 concentration were found to be 2.5% and 0.1 M, respectively, and optimal enzyme loading ratio was determined as 2:1:0.02 for pectinase, protease, and α-amylase, respectively. Next, the immobilization of multiple enzymes on glutaraldehyde-activated chitosan beads was optimized (3% chitosan concentration, 0.25% glutaraldehyde with 3 h of activation and 3 h of coupling time). While co-immobilization was successfully performed with both materials, the specific activities of enzymes were found to be higher for the enzymes co-immobilized with glutaraldehyde-activated chitosan beads. In this process, glutaraldehyde was acting as a spacer arm. SEM and FTIR were used for the characterization of activated chitosan beads. Moreover, pectinase and α-amylase enzymes immobilized with chitosan beads were also found to have higher activity than their free forms. Three different enzymes were co-immobilized with these two materials for the first time in this study.

Fissile material disposition program final immobilization form assessment and recommendation

International Nuclear Information System (INIS)

Cochran, S.G.; Dunlop, W.H.; Edmunds, T.A.; MacLean, L.M.; Gould, T.H.

1997-01-01

Lawrence Livermore National Laboratory (LLNL), in its role as the lead laboratory for the development of plutonium immobilization technologies for the Department of Energy's Office of Fissile Materials Disposition (MD), has been requested by MD to recommend an immobilization technology for the disposition of surplus weapons- usable plutonium. The recommendation and supporting documentation was requested to be provided by September 1, 1997. This report addresses the choice between glass and ceramic technologies for immobilizing plutonium using the can-in-canister approach. Its purpose is to provide a comparative evaluation of the two candidate technologies and to recommend a form based on technical considerations

Influence of Immobilization and X-rays on the Animal Behavior

International Nuclear Information System (INIS)

Melitauri, N.; Jojua, M.; Chabashvili, M.; Marsagishvili, G.; Maisuradze, I.; Nikolaishvili, M.; Iordanishvili, G.

2006-01-01

It was shown that four-hour immobilization of the normal rats, in 70% of the animals induced elevated aggressiveness; it diminishes at twelfth day, while in a case of 7 Gy X-ray irradiation, aggressiveness disappears at second day. The X-rays decreased the number of the immobilized animals with retained fear reactions, and abolished the already acquired active avoidance responses. It was determined that the immobilized animals in the ''Open field'' test differed from the normal ones with lesser ambulation, orienting-exploratory activity, and emotionality, which reversed to the contrary values after the X-rays. (authors)

Compound immobilization and drug-affinity chromatography.

Science.gov (United States)

Rix, Uwe; Gridling, Manuela; Superti-Furga, Giulio

2012-01-01

Bioactive small molecules act through modulating a yet unpredictable number of targets. It is therefore of critical importance to define the cellular target proteins of a compound as an entry point to understanding its mechanism of action. Often, this can be achieved in a direct fashion by chemical proteomics. As with any affinity chromatography, immobilization of the bait to a solid support is one of the earliest and most crucial steps in the process. Interfering with structural features that are important for identification of a target protein will be detrimental to binding affinity. Also, many molecules are sensitive to heat or to certain chemicals, such as acid or base, and might be destroyed during the process of immobilization, which therefore needs to be not only efficient, but also mild. The subsequent affinity chromatography step needs to preserve molecular and conformational integrity of both bait compound and proteins in order to result in the desired specific enrichment while ensuring a high level of compatibility with downstream analysis by mass spectrometry. Thus, the right choice of detergent, buffer, and protease inhibitors is also essential. This chapter describes a widely applicable procedure for the immobilization of small molecule drugs and for drug-affinity chromatography with subsequent protein identification by mass spectrometry.

Arsenic immobilization by calcium-arsenic precipitates in lime treated soils

International Nuclear Information System (INIS)

Moon, Deok Hyun; Dermatas, Dimitris; Menounou, Nektaria

2004-01-01

Lime-based stabilization/solidification (S/S) can be an effective remediation alternative for the immobilization of arsenic (As) in contaminated soils and sludges. However, the exact immobilization mechanism has not been well established. Based on previous research, As immobilization could be attributed to sorption and/or inclusion in pozzolanic reaction products and/or the formation of calcium-arsenic (Ca-As) precipitates. In this study, suspensions of lime-As and lime-As-kaolinite were studied in an attempt to elucidate the controlling mechanism of As immobilization in lime treated soils. Aqueous lime-As suspensions (slurries) with varying Ca/As molar ratios (1:1, 1.5:1, 2:1, 2.5:1 and 4:1) were prepared and soluble As concentrations were determined. X-Ray diffraction (XRD) analyses were used to establish the resulting mineralogy of crystalline precipitate formation. Depending on the redox state of the As source, different As precipitates were identified. When As (III) was used, the main precipitate formation was Ca-As-O. With As(V) as the source, Ca 4 (OH) 2 (AsO 4 ) 2 ·4H 2 O formed at Ca/As molar ratios greater than 1:1. A significant increase in As (III) immobilization was observed at Ca/As molar ratios greater than 1:1. Similarly, a substantial increase in As (V) immobilization was noted at Ca/As molar ratios greater than or equal to 2.5:1. This observation was also confirmed by XRD. Lime-As-kaolinite slurries were also prepared at different Ca/As molar ratios. These slurries were used to specifically investigate the possibility of forming pozzolanic reaction products. Such products would immobilize As by sorption and/or inclusion along with the formations of different As precipitates. Toxicity Characteristic Leaching Procedure (TCLP) tests were used to evaluate As leachability in these slurries. XRD analyses revealed no pozzolanic reaction product formation. Instead, As immobilization was found to be precipitation controlled. The same Ca-As precipitate, Ca

Biocatalytic conversion of wheat bran hydrolysate using an immobilized GH43 beta-xylosidase.

Science.gov (United States)

Smaali, Issam; Rémond, Caroline; Skhiri, Yousr; O'Donohue, Michael J

2009-01-01

To investigate the concept of a xylosidase-based process for the continuous production of xylose from arabinoxylan-containing feedstocks, a beta-xylosidase from Bacillus halodurans C-125 was immobilized and deployed in packed bed reactor (PBR). Among the several immobilization methods tested, glutaraldehyde-mediated immobilization on chitosan was the best both in terms of immobilization and activity yields (91% and 72.9%, respectively). In batch experiments the immobilized enzyme hydrolyzed wheat bran hydrolysates quite efficiently, consuming nearly all xylobiose and xylotriose after 6h. Its reusability showed only a 50% decrease of its activity after 92h. Using the chitosan-immobilized beta-xylosidase in a PBR, xylose productivity was 7.2g xylose l(-1)h(-1) and the conversion factor was 0.55 (derived from initial xylose in the substrate). The operational stability of the PBR was good, because only 25% of productivity was lost after the treatment of three batches of substrate over a 72-h period.

Clinical application of vacuum bag immobilization of the trunk in malignant tumor patients

International Nuclear Information System (INIS)

Su Jianxin; Wu Yuqi; Huang Jun; Lin Chengguang; Liu Hui; Huang Xiaoyan

2005-01-01

Objective: To evaluate the clinical application of vacuum bag immobilization of thorax and pelvis for patients with malignant tumors. Methods: Of 714 patients (fields) chosen randomly, 582(fields) were immobilized with vacuum bag, while the other 132 (fields) used only sand bags, tapes, and other simple immobilizing devices. The field movements were measured and compared before and after the setup, along with 56 patients immobilized twice with vacuum bag. Results: The variance of movement before and after the setup was 6.7% for patients with vacuum bag , while that was 26.5% for patients without the vacuum bag. It was even 32.1% for patients immobilized twice with vacuum bag. Conclusions: The variance of movement decreases significantly with vacuum bag immobilization. It should be used as frequently as possible. As the variance of movement rises obviously when vacuum bag is used twice, the semi-soft vacuum bag should be prepared afresh and checked under the simulator before the second use. (authors)

Dye decolorization and detoxification potential of Ca-alginate beads immobilized manganese peroxidase.

Science.gov (United States)

Bilal, Muhammad; Asgher, Muhammad

2015-12-10

In view of compliance with increasingly stringent environmental legislation, an eco-friendly treatment technology of industrial dyes and effluents is a major environmental challenge in the color industry. In present study, a promising and eco-friendly entrapment approach was adopted to immobilize purified manganese peroxidase (MnP) produced from an indigenous strain of Ganoderma lucidum IBL-05 on Ca-alginate beads. The immobilized MnP was subsequently used for enhanced decolorization and detoxification of textile reactive dyes). MnP isolated from solid-state culture of G. lucidum IBL-05, presented highest immobilization yield (83.9 %) using alginate beads prepared at optimized conditions of 4 % (w/v) sodium alginate, 2 % (w/v) Calcium chloride (CaCl2) and 0.5 mg/ml enzyme concentration. Immobilization of MnP enhanced optimum temperature but caused acidic shift in optimum pH of the enzyme. The immobilized MnP showed optimum activity at pH 4.0 and 60 °C as compared to pH 5.0 and 35 °C for free enzyme. The kinetic parameters K(m) and V(max) of MnP were significantly improved by immobilization. The enhanced catalytic potential of immobilized MnP led to 87.5 %, 82.1 %, 89.4 %, 95.7 % and 83 % decolorization of Sandal-fix Red C4BLN, Sandal-fix Turq Blue GWF, Sandal-fix Foron Blue E2BLN, Sandal-fix Black CKF and Sandal-fix Golden Yellow CRL dyes, respectively. The insolubilized MnP was reusable for 7 repeated cycles in dye color removal. Furthermore, immobilized MnP also caused a significant reduction in biochemical oxygen demand (BOD) (94.61-95.47 %), chemical oxygen demand (COD) (91.18-94.85 %), and total organic carbon (TOC) (89.58-95 %) of aqueous dye solutions. G. lucidum MnP was immobilized in Ca-alginate beads by entrapment method to improve its practical effectiveness. Ca-alginate bound MnP was catalytically more vigorous, thermo-stable, reusable and worked over wider ranges of pH and temperature as compared to its free counterpart. Results of cytotoxicity like

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

Directory of Open Access Journals (Sweden)

C.C.F. Nascimento

2008-09-01

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

Cortical Reorganization after Hand Immobilization: The beta qEEG Spectral Coherence Evidences

Science.gov (United States)

Fortuna, Marina; Teixeira, Silmar; Machado, Sérgio; Velasques, Bruna; Bittencourt, Juliana; Peressutti, Caroline; Budde, Henning; Cagy, Mauricio; Nardi, Antonio E.; Piedade, Roberto; Ribeiro, Pedro; Arias-Carrión, Oscar

2013-01-01

There is increasing evidence that hand immobilization is associated with various changes in the brain. Indeed, beta band coherence is strongly related to motor act and sensitive stimuli. In this study we investigate the electrophysiological and cortical changes that occur when subjects are submitted to hand immobilization. We hypothesized that beta coherence oscillations act as a mechanism underlying inter- and intra-hemispheric changes. As a methodology for our study fifteen healthy individuals between the ages of 20 and 30 years were subjected to a right index finger task before and after hand immobilization while their brain activity pattern was recorded using quantitative electroencephalography. This analysis revealed that hand immobilization caused changes in frontal, central and parietal areas of the brain. The main findings showed a lower beta-2 band in frontal regions and greater cortical activity in central and parietal areas. In summary, the coherence increased in the frontal, central and parietal cortex, due to hand immobilization and it adjusted the brains functioning, which had been disrupted by the procedure. Moreover, the brain adaptation upon hand immobilization of the subjects involved inter- and intra-hemispheric changes. PMID:24278213

Biodegradation of Mustard

Science.gov (United States)

1994-07-01

different areas of Kuwait. The isolates were identified as Asoeraillus terreus, h. IlabirM, Mucor alobosus, usarium sp . and Penicillium citrinum (94...Thiobacillus delicatus nov. sp . J. Ferment . Technol. 54:181-191 (1976). (39) Harrison, AP. The acidophilic thiobacilli and other acidophilic bacteria...methyl sulfide is oxidized to sulfate by Hnhomicrobium S sp ., Hynhomicrobu EG (21-23), Thiobacillus thioDarus TK-m and Thiobacillus MS1 (24,25), but only

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

Energy Technology Data Exchange (ETDEWEB)

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

2005-10-01

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

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

International Nuclear Information System (INIS)

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

2005-01-01

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

Covalent immobilization of penicillin G acylase on aminopropyl-functionalized mesostructured cellular foams.

Science.gov (United States)

Zhao, Junqi; Wang, Yujun; Luo, Guangsheng; Zhu, Shenlin

2010-10-01

Mesostructured cellular foams (MCFs) are suitable for biomolecular immobilization because of their relatively large-pore diameter and pore volume. Penicillin G acylase (PGA) was immobilized on aminopropyl-functionalized MCFs through Schiff base reaction. It is shown that PGA could be fixed more firmly through the covalent immobilization on aminopropyl-functionalized MCFs support than through the adsorption immobilization on blank MCFs. The PGA loading amount on the aminopropyl-functionalized MCFs could reach 443 mg/g (dry support), and the apparent activity could achieve up to 4138 U/g (dry support). The influence of the amount of grafted aminopropyl group was studied, and it is found that the optimal molar ratio of MCFs to APTS was 15/1; in addition, the suitable enzyme distribution density for the specific activity of the immobilized PGA was 0.7 mg enzyme per m(2) of specific area of MCFs. Copyright 2010 Elsevier Ltd. All rights reserved.

Immobilization of cross-linked tannase enzyme on multiwalled carbon nanotubes and its catalytic behavior.

Science.gov (United States)

Ong, Chong-Boon; Annuar, Mohamad S M

2018-02-07

Immobilization of cross-linked tannase on pristine multiwalled carbon nanotubes (MWCNT) was successfully performed. Cross-linking of tannase molecules was made through glutaraldehyde. The immobilized tannase exhibited significantly improved pH, thermal, and recycling stability. The optimal pH for both free and immobilized tannase was observed at pH 5.0 with optimal operating temperature at 30°C. Moreover, immobilized enzyme retained greater biocatalytic activities upon 10 repeated uses compared to free enzyme in solution. Immobilization of tannase was accomplished by strong hydrophobic interaction most likely between hydrophobic amino acid moieties of the glutaraldehyde-cross-linked tannase to the MWCNT.

NCBI nr-aa BLAST: CBRC-DNOV-01-2878 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-DNOV-01-2878 ref|YP_680769.1| murein endopeptidase [Roseobacter denitrificans ...OCh 114] gb|ABG30083.1| murein endopeptidase [Roseobacter denitrificans OCh 114] YP_680769.1 1.4 29% ...

Removal of Strontium Ions by Immobilized Saccharomyces Cerevisiae in Magnetic Chitosan Microspheres

Directory of Open Access Journals (Sweden)

Yanan Yin

2017-02-01

Full Text Available A novel biosorbent, immobilized Saccharomyces cerevisiae in magnetic chitosan microspheres was prepared, characterized, and used for the removal of Sr2+ from aqueous solution. The structure and morphology of immobilized S. cerevisiae before and after Sr2+adsorption were observed using scanning electron microscopy with energy dispersive X-ray spectroscopy. The experimental results showed that the Langmuir and Freundlich isotherm models could be used to describe the Sr2+ adsorption onto immobilized S. cerevisiae microspheres. The maximal adsorption capacity (qm was calculated to be 81.96 mg/g by the Langmuir model. Immobilized S. cerevisiae was an effective adsorbent for the Sr2+ removal from aqueous solution.

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

DEFF Research Database (Denmark)

Alftrén, Johan

feedstocks containing insolubles. This could potentially be overcome by immobilizing the cellulases on magnetically susceptible particles. Consequently, the immobilized cellulases could be magnetically recovered and recycled for a new cycle of enzymatic hydrolysis of cellulose. The main objective...... of this thesis was to examine the possibility of immobilizing cellulases on magnetic particles in order to enable enzyme re-use. Studies at lab and pilot scale (20 L) were conducted using model and real substrates. In paper I and III beta-glucosidase or a whole cellulase mixture was covalently immobilized...... on commercial, but expensive, magnetic particles activated with different chemistries. It was observed that the highest immobilized enzyme activities were obtained using magnetic particles activated with cyanuric chloride. In paper II biotinylated recombinant beta-glucosidase was produced and immobilized...

Antibody Immobilization on Conductive Polymer Coated Nonwoven Fibers for Biosensors

Directory of Open Access Journals (Sweden)

Shannon K. MCGRAW

2011-12-01

Full Text Available This work is being performed to develop rapid and novel electrochemical biosensors for foodborne pathogen detection. This research focuses on electrotextile platforms to perform both capture and sensing functions in a single component. The biosensor uses nonwoven fiber membranes coated with conductive polymer and functionalized with antibodies for biological capture. This study examines three methods for antibody immobilization: passive adsorption, glutaraldehyde cross-linking, and EDC/Sulfo-NHS cross-linking. Antibodies are immobilized onto the conductive fiber surfaces for the specific capture of a target pathogen. The immobilization and capture capabilities of each method are analyzed through the use of two different fluorescent reporters: FITC and PicoGreen DNA stain. Fluorescence is measured using a fluorescent plate reader and then imaged using a fluorescent microscope. The effect of a blocking agent on specificity is also evaluated. It is found that glutaraldehyde with blocking is the best immobilization method with PicoGreen being the best fluorescent reporter.

Immobilization of bacterial proteases on water-solved polymer by means of electron beam

Science.gov (United States)

Gonchar, A. M.; Auslender, V. L.

1996-12-01

Possibility of electron beam usage for proteases' immobilization on 1,4-polyalkylene oxide (1,4-PAO) was studied to obtain biologically active complex for multi-purpose usage. It is shown that immobilization of Bacillus Subtilis protease takes place due to free-radical linking of enzyme and carrier with formation of mycellium-like structures. Immobilization improves heat resistance of enzyme up to 60°C without substrate and up to 80°C in presence of substrate, widens range of pH activity in comparison with non-immobilized forms. Immobilized proteases do not contain peroxides or long-live radicals. Our results permitted to create technologies for production of medical and veterinary preparations, active components for wool washing agents and leather fabrication technology.

Immobilization of bacterial proteases on water-solved polymer by means of electron beam

International Nuclear Information System (INIS)

Gonchar, A.M.; Auslender, V.L.

1996-01-01

Possibility of electron beam usage for proteases' immobilization on 1,4-polyalkylene oxide (1,4-PAO) was studied to obtain biologically active complex for multi-purpose usage. It is shown that immobilization of Bacillus Subtilis protease takes place due to free-radical linking of enzyme and carrier with formation of mycellium-like structures. Immobilization improves heat resistance of enzyme up to 60 o C without substrate and up to 80 o C in presence of substrate, widens range of pH activity in comparison with non-immobilized forms. Immobilized proteases do not contain peroxides or long-live radicals. Our results permitted to create technologies for production of medical and veterinary preparations, active components for wool washing agents and leather fabrication technology. (Author)

Transcriptional and metabolic regulation of denitrification in Paracoccus denitrificans allows low but significant activity of nitrous oxide reductase under oxic conditions.

Science.gov (United States)

Qu, Zhi; Bakken, Lars R; Molstad, Lars; Frostegård, Åsa; Bergaust, Linda L

2016-09-01

Oxygen is known to repress denitrification at the transcriptional and metabolic levels. It has been a common notion that nitrous oxide reductase (N2 OR) is the most sensitive enzyme among the four N-oxide reductases involved in denitrification, potentially leading to increased N2 O production under suboxic or fluctuating oxygen conditions. We present detailed gas kinetics and transcription patterns from batch culture experiments with Paracoccus denitrificans, allowing in vivo estimation of e(-) -flow to O2 and N2 O under various O2 regimes. Transcription of nosZ took place concomitantly with that of narG under suboxic conditions, whereas transcription of nirS and norB was inhibited until O2 levels approached 0 μM in the liquid. Catalytically functional N2 OR was synthesized and active in aerobically raised cells transferred to vials with 7 vol% O2 in headspace, but N2 O reduction rates were 10 times higher when anaerobic pre-cultures were subjected to the same conditions. Upon oxygen exposure, there was an incomplete and transient inactivation of N2 OR that could be ascribed to its lower ability to compete for electrons compared with terminal oxidases. The demonstrated reduction of N2 O at high O2 partial pressure and low N2 O concentrations by a bacterium not known as a typical aerobic denitrifier may provide one clue to the understanding of why some soils appear to act as sinks rather than sources for atmospheric N2 O. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

{sup 125}I Labelling of Protein Using Immobilized Enzyme

Energy Technology Data Exchange (ETDEWEB)

Kim, Jae Rok; Park, Kyung Bae; Awh, Ok Doo [Korea Advanced Energy Research Institute, Daejeon (Korea, Republic of)

1984-03-15

For an effective solid-phase labelling of protein with {sup 125}I, studies on the immobilization of lactoperoxidase (LPO) on the inner wall of polystyrene tubes were carried out. Labelling of bovine serum albumin (BSA) and insulin was also practiced using the LPO immobilized tubes. The immobilized enzyme of about 2.5 mu g/tube was sufficient for small scale labelling since the results of radio-paper chromatography of the labelling mixture of insulin indicated that the yields were sufficiently high (80%) even in the reactions conducted at room temperature for 60 sec. The results of the Sephadex column chromatography indicated that the labelled products were not contaminated with LPO-{sup 125}I, and the radiochemical purity of the products was more than 90%. In considering the general trend that the {sup 125}I labelled protein obtained by using LPO maintains its intactness better than those obtained by using chloramine-T, together with the tendency of yield enhancing with increase of reactants-concentration, the LPO immobilized tube method is estimated to be one of the simple methods of labelling. The product might be applicable without further purification.

Assessment of "YouTube" Content for Distal Radius Fracture Immobilization.

Science.gov (United States)

Addar, Abdullah; Marwan, Yousef; Algarni, Nizar; Berry, Gregory

Distal radius fractures (DRFs) are the most common orthopedic fractures, with >70% of cases treated by closed immobilization using a short arm cast or a sugar tong splint. However, inadequate immobilization is a risk factor for loss of reduction requiring repeat reduction or surgical treatment. Therefore, education of clinical skills for appropriate immobilization of DRFs is important. With the increasing use of web-based information by medical learners, our aim was to assess the quality and quantity of videos regarding closed immobilization of DRFs on YouTube. Retrospective review of YouTube videos on distal radius fracture immobilization using specific search terms. Identified videos were analyzed for their educational value, quality of the technical skill demonstrated, and overall metrics. Educational value was scored on a 5-point scale, with "1" indicative of low quality and "5" of high quality. Not applicable. Among the 68,366 videos identified, 16 met our inclusion criteria of being in English; performed by a health care professional or institution; and with casting being the major theme of the educational information provided. Of these 16 videos, 6 had an educational value score of 4 or 5, with the remaining 10 having a score ≤3. Although immobilization was demonstrated by cast technician specialized in orthopedics, skills were also performed by orthopedic attendants, urgent care physicians, orthopedic residents, and nurse practitioners. The credentials of the performer in 3 videos were not identified. There is a need to promote high-quality educational videos produced by established medical school faculty members on open, web-based, portals. Copyright © 2017 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

Scandium sorption by immobilized microdispersed forms of phosporus-containing ion exchangers

International Nuclear Information System (INIS)

Sokolova, Yu.V.; Kurdyumov, G.M.; Smirnov, A.V.; Mezhirov, M.S.

1991-01-01

The possibility to improve considerably kinetics of scandium sorption by phosphate ion exchangers, immobilized into polyacrylonitrile (PAN) fibers, as compared with granular samples of ion exchangers, was shown. The influence of dispersion degree of immobilized ionite particles on sorption rate was studied. It is ascertained that the ionite grinding to the particle size ≤ 52 μm is sufficient for the rate increase by 1-1.5 orders. A lower swelling of the immobilized ion exchanger is its additional advantage as compared with granular form

(Au/PANA/PVAc) nanofibers as a novel composite matrix for albumin and streptavidin immobilization

Energy Technology Data Exchange (ETDEWEB)

Golshaei, Rana [University of Kashan, Institute of Nano Science and Nano Technology, Kashan, P.O. Box 87317-51167, Islamic Republic of Iran (Iran, Islamic Republic of); Guler, Zeliha [Istanbul Technical University, Nanoscience and Nanoengineering, Maslak, Istanbul 34469 (Turkey); Sarac, Sezai A., E-mail: sarac@itu.edu.tr [Istanbul Technical University, Nanoscience and Nanoengineering, Maslak, Istanbul 34469 (Turkey); Istanbul Technical University, Department of Chemistry and Polymer Science and Technology, Maslak, Istanbul 34469 (Turkey)

2016-03-01

A novel electrospun nanofiber mat (Au/PANA/PVAc) consists of (Gold/Poly Anthranilic acid) (Au/PANA) core/shell nanostructures as a support material for protein immobilization that was developed and characterized by electrochemical impedance spectroscopy. In the core/shells, PANA served carboxyl groups (− COOH) for covalent protein immobilization and Au enhanced the electrochemical properties by acting as tiny conduction centers to facilitate electron transfer. Covalent immobilization of albumin and streptavidin as model proteins onto the (Au/PANA/PVAc) nanofibers was carried out by using 1-ethyl-3-(dimethyl-aminopropyl) carbodiimide hydrochloride (EDC)/N-hydroxyl succinimide (NHS) activation. PVAc nanofibers were compared with Au/PANA/PVAc nanofibers before and after protein immobilization. The successful covalent binding of both albumin and streptavidin onto (Au/PANA/PVAc) nanofibers was confirmed by FTIR-ATR, Electron Microscopy/Energy-Dispersive X-ray Spectroscopy SEM/EDX and Electrochemical impedance spectroscopy (EIS). The nanofibers became resistive due to protein immobilization and the higher charge transfer resistance was observed after higher amount of protein was immobilized. - Highlights: • Au/PANA/PVAc nanofibers with (COOH) groups as a suitable supports for covalent immobilization of proteins. • Increasing of the resistivity of the nanofibers after immobilization of the proteins. • Activation of Au/PANA/PVAc nanofibers by using EDC/NHS.

Fluctuation correlation models for receptor immobilization

Science.gov (United States)

Fourcade, B.

2017-12-01

Nanoscale dynamics with cycles of receptor diffusion and immobilization by cell-external-or-internal factors is a key process in living cell adhesion phenomena at the origin of a plethora of signal transduction pathways. Motivated by modern correlation microscopy approaches, the receptor correlation functions in physical models based on diffusion-influenced reaction is studied. Using analytical and stochastic modeling, this paper focuses on the hybrid regime where diffusion and reaction are not truly separable. The time receptor autocorrelation functions are shown to be indexed by different time scales and their asymptotic expansions are given. Stochastic simulations show that this analysis can be extended to situations with a small number of molecules. It is also demonstrated that this analysis applies when receptor immobilization is coupled to environmental noise.

Effect of sulfonylureas administered centrally on the blood glucose level in immobilization stress model.

Science.gov (United States)

Sharma, Naveen; Sim, Yun-Beom; Park, Soo-Hyun; Lim, Su-Min; Kim, Sung-Su; Jung, Jun-Sub; Hong, Jae-Seung; Suh, Hong-Won

2015-05-01

Sulfonylureas are widely used as an antidiabetic drug. In the present study, the effects of sulfonylurea administered supraspinally on immobilization stress-induced blood glucose level were studied in ICR mice. Mice were once enforced into immobilization stress for 30 min and returned to the cage. The blood glucose level was measured 30, 60, and 120 min after immobilization stress initiation. We found that intracerebroventricular (i.c.v.) injection with 30 µg of glyburide, glipizide, glimepiride or tolazamide attenuated the increased blood glucose level induced by immobilization stress. Immobilization stress causes an elevation of the blood corticosterone and insulin levels. Sulfonylureas pretreated i.c.v. caused a further elevation of the blood corticosterone level when mice were forced into the stress. In addition, sulfonylureas pretreated i.c.v. alone caused an elevation of the plasma insulin level. Furthermore, immobilization stress-induced insulin level was reduced by i.c.v. pretreated sulfonylureas. Our results suggest that lowering effect of sulfonylureas administered supraspinally against immobilization stress-induced increase of the blood glucose level appears to be primarily mediated via elevation of the plasma insulin level.

Improvement of the homogeneity of protein-imprinted polymer films by orientated immobilization of the template

Energy Technology Data Exchange (ETDEWEB)

Liu Lijian; Zheng Jingjing; Fang Guijie [Key Laboratory of Fermentation Engineering (Ministry of Education), College of Bioengineering, Hubei University of Technology, Nanhu Li Jia Dun 1, Wuhan 430068 (China); Xie Weihong, E-mail: weihong.xie@yahoo.com.cn [Key Laboratory of Fermentation Engineering (Ministry of Education), College of Bioengineering, Hubei University of Technology, Nanhu Li Jia Dun 1, Wuhan 430068 (China)

2012-05-13

Highlights: Black-Right-Pointing-Pointer MPH was genetically modified at its C-terminal with (Gly-Ser){sub 5}-Cys. Black-Right-Pointing-Pointer MPH-L was immobilized with fixed orientation via disulfide chemistry. Black-Right-Pointing-Pointer The immobilized MPH-L retained the activity of MPH. Black-Right-Pointing-Pointer MPH-L formed a homogeneous template. Black-Right-Pointing-Pointer Homogeneous MIP film was obtained with orientated immobilization of the template. - Abstract: A method for preparing homogeneous protein-imprinted polymer films with orientated immobilization of template is described. The template methyl parathion hydrolase (MPH) was modified with a peptide linker (Gly-Ser){sub 5}-Cys and was immobilized on a cover glass with a fixed orientation via the linker. The activity of the fusion enzyme (MPH-L) was evaluated by determining the product's absorbance at 405 nm (A{sub 405}). Both the free and the immobilized MPH-L showed higher retention of the bioactivity than the wide type enzyme (MPH-W) as revealed by the A{sub 405} values for MPH-L{sub free}/MPH-W{sub free} (1.159/1.111) and for MPH-L{sub immobilized}/MPH-W{sub immobilized} (0.348/0.118). The immobilized MPH-L also formed a more homogeneous template stamp compared to the immobilized MPH-W. The molecularly imprinted polymer films prepared with the immobilized MPH-L exhibited high homogeneity with low Std. Deviations of 80 and 200 from the CL intensity mean volumes which were observed for batch-prepared films and an individual film, respectively. MPH-L-imprinted polymer film also had a larger template binding capacity indicated by higher CL intensity mean volume of 3900 INT over 2500 INT for MPH-W-imprinted films. The imprinted film prepared with the orientated immobilization of template showed an imprinting factor of 1.7, while the controls did not show an imprinting effect.

Improvement of the homogeneity of protein-imprinted polymer films by orientated immobilization of the template

International Nuclear Information System (INIS)

Liu Lijian; Zheng Jingjing; Fang Guijie; Xie Weihong

2012-01-01

Highlights: ► MPH was genetically modified at its C-terminal with (Gly-Ser) 5 –Cys. ► MPH-L was immobilized with fixed orientation via disulfide chemistry. ► The immobilized MPH-L retained the activity of MPH. ► MPH-L formed a homogeneous template. ► Homogeneous MIP film was obtained with orientated immobilization of the template. - Abstract: A method for preparing homogeneous protein-imprinted polymer films with orientated immobilization of template is described. The template methyl parathion hydrolase (MPH) was modified with a peptide linker (Gly-Ser) 5 –Cys and was immobilized on a cover glass with a fixed orientation via the linker. The activity of the fusion enzyme (MPH-L) was evaluated by determining the product's absorbance at 405 nm (A 405 ). Both the free and the immobilized MPH-L showed higher retention of the bioactivity than the wide type enzyme (MPH-W) as revealed by the A 405 values for MPH-L free /MPH-W free (1.159/1.111) and for MPH-L immobilized /MPH-W immobilized (0.348/0.118). The immobilized MPH-L also formed a more homogeneous template stamp compared to the immobilized MPH-W. The molecularly imprinted polymer films prepared with the immobilized MPH-L exhibited high homogeneity with low Std. Deviations of 80 and 200 from the CL intensity mean volumes which were observed for batch-prepared films and an individual film, respectively. MPH-L-imprinted polymer film also had a larger template binding capacity indicated by higher CL intensity mean volume of 3900 INT over 2500 INT for MPH-W-imprinted films. The imprinted film prepared with the orientated immobilization of template showed an imprinting factor of 1.7, while the controls did not show an imprinting effect.

Immobilization of zinc from metallurgical waste and water solutions using geopolymerization technology

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Nikolići I.

2014-07-01

Full Text Available Geopolymeraization technology is recognized as a promising method for immobilization of heavy metals by the stabilization or solidification process. This process involves the chemical reaction of alumino-silicate oxides with highly alkaline activator yielding the new material with amorphous or semi-amorphous structure, called geopolymer. Fly ash and blast furnace slag were mainly used as a raw material for geopolymerization process. In this paper we have investigated the possibility of immobilization of Zn from electric arc furnace dust (EAFD through geopolymerization of fly ash and possibility of Zn2+ adsorption from waste waters using fly ash based geopolymers. Efficacy of Zn immobilization from electric arc furnace dust was evaluated by TCLP test while the immobilization of Zn2+ ions from the water solution was evaluated through the removal efficiency. The results have shown that geopolymerization process may successfully be used for immobilization of Zn by stabilization of EAFD and for production of low cost adsorbent for waste water treatment.

Effective L-Tyrosine Hydroxylation by Native and Immobilized Tyrosinase.

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Małgorzata Cieńska

Full Text Available Hydroxylation of L-tyrosine to 3,4-dihydroxyphenylalanine (L-DOPA by immobilized tyrosinase in the presence of ascorbic acid (AH2, which reduces DOPA-quinone to L-DOPA, is characterized by low reaction yields that are mainly caused by the suicide inactivation of tyrosinase by L-DOPA and AH2. The main aim of this work was to compare processes with native and immobilized tyrosinase to identify the conditions that limit suicide inactivation and produce substrate conversions to L-DOPA of above 50% using HPLC analysis. It was shown that immobilized tyrosinase does not suffer from partitioning and diffusion effects, allowing a direct comparison of the reactions performed with both forms of the enzyme. In typical processes, additional aeration was applied and boron ions to produce the L-DOPA and AH2 complex and hydroxylamine to close the cycle of enzyme active center transformations. It was shown that the commonly used pH 9 buffer increased enzyme stability, with concomitant reduced reactivity of 76%, and that under these conditions, the maximal substrate conversion was approximately 25 (native to 30% (immobilized enzyme. To increase reaction yield, the pH of the reaction mixture was reduced to 8 and 7, producing L-DOPA yields of approximately 95% (native enzyme and 70% (immobilized. A three-fold increase in the bound enzyme load achieved 95% conversion in two successive runs, but in the third one, tyrosinase lost its activity due to strong suicide inactivation caused by L-DOPA processing. In this case, the cost of the immobilized enzyme preparation is not overcome by its reuse over time, and native tyrosinase may be more economically feasible for a single use in L-DOPA production. The practical importance of the obtained results is that highly efficient hydroxylation of monophenols by tyrosinase can be obtained by selecting the proper reaction pH and is a compromise between complexation and enzyme reactivity.

Effective L-Tyrosine Hydroxylation by Native and Immobilized Tyrosinase.

Science.gov (United States)

Cieńska, Małgorzata; Labus, Karolina; Lewańczuk, Marcin; Koźlecki, Tomasz; Liesiene, Jolanta; Bryjak, Jolanta

2016-01-01

Hydroxylation of L-tyrosine to 3,4-dihydroxyphenylalanine (L-DOPA) by immobilized tyrosinase in the presence of ascorbic acid (AH2), which reduces DOPA-quinone to L-DOPA, is characterized by low reaction yields that are mainly caused by the suicide inactivation of tyrosinase by L-DOPA and AH2. The main aim of this work was to compare processes with native and immobilized tyrosinase to identify the conditions that limit suicide inactivation and produce substrate conversions to L-DOPA of above 50% using HPLC analysis. It was shown that immobilized tyrosinase does not suffer from partitioning and diffusion effects, allowing a direct comparison of the reactions performed with both forms of the enzyme. In typical processes, additional aeration was applied and boron ions to produce the L-DOPA and AH2 complex and hydroxylamine to close the cycle of enzyme active center transformations. It was shown that the commonly used pH 9 buffer increased enzyme stability, with concomitant reduced reactivity of 76%, and that under these conditions, the maximal substrate conversion was approximately 25 (native) to 30% (immobilized enzyme). To increase reaction yield, the pH of the reaction mixture was reduced to 8 and 7, producing L-DOPA yields of approximately 95% (native enzyme) and 70% (immobilized). A three-fold increase in the bound enzyme load achieved 95% conversion in two successive runs, but in the third one, tyrosinase lost its activity due to strong suicide inactivation caused by L-DOPA processing. In this case, the cost of the immobilized enzyme preparation is not overcome by its reuse over time, and native tyrosinase may be more economically feasible for a single use in L-DOPA production. The practical importance of the obtained results is that highly efficient hydroxylation of monophenols by tyrosinase can be obtained by selecting the proper reaction pH and is a compromise between complexation and enzyme reactivity.

Effective L-Tyrosine Hydroxylation by Native and Immobilized Tyrosinase

Science.gov (United States)

Lewańczuk, Marcin; Koźlecki, Tomasz; Liesiene, Jolanta; Bryjak, Jolanta

2016-01-01

Hydroxylation of L-tyrosine to 3,4-dihydroxyphenylalanine (L-DOPA) by immobilized tyrosinase in the presence of ascorbic acid (AH2), which reduces DOPA-quinone to L-DOPA, is characterized by low reaction yields that are mainly caused by the suicide inactivation of tyrosinase by L-DOPA and AH2. The main aim of this work was to compare processes with native and immobilized tyrosinase to identify the conditions that limit suicide inactivation and produce substrate conversions to L-DOPA of above 50% using HPLC analysis. It was shown that immobilized tyrosinase does not suffer from partitioning and diffusion effects, allowing a direct comparison of the reactions performed with both forms of the enzyme. In typical processes, additional aeration was applied and boron ions to produce the L-DOPA and AH2 complex and hydroxylamine to close the cycle of enzyme active center transformations. It was shown that the commonly used pH 9 buffer increased enzyme stability, with concomitant reduced reactivity of 76%, and that under these conditions, the maximal substrate conversion was approximately 25 (native) to 30% (immobilized enzyme). To increase reaction yield, the pH of the reaction mixture was reduced to 8 and 7, producing L-DOPA yields of approximately 95% (native enzyme) and 70% (immobilized). A three-fold increase in the bound enzyme load achieved 95% conversion in two successive runs, but in the third one, tyrosinase lost its activity due to strong suicide inactivation caused by L-DOPA processing. In this case, the cost of the immobilized enzyme preparation is not overcome by its reuse over time, and native tyrosinase may be more economically feasible for a single use in L-DOPA production. The practical importance of the obtained results is that highly efficient hydroxylation of monophenols by tyrosinase can be obtained by selecting the proper reaction pH and is a compromise between complexation and enzyme reactivity. PMID:27711193

TiO₂ beads and TiO₂-chitosan beads for urease immobilization.

Science.gov (United States)

Ispirli Doğaç, Yasemin; Deveci, Ilyas; Teke, Mustafa; Mercimek, Bedrettin

2014-09-01

The aim of the present study is to synthesize TiO2 beads for urease immobilization. Two different strategies were used to immobilize the urease on TiO2 beads. In the first method (A), urease enzyme was immobilized onto TiO2 beads by adsorption and then crosslinking. In the second method (B), TiO2 beads were coated with chitosan-urease mixture. To determine optimum conditions of immobilization, different parameters were investigated. The parameters of optimization were initial enzyme concentration (0.5; 1; 1.5; 2mg/ml), alginate concentration (1; 2; 3%), glutaraldehyde concentration (1; 2; 3% v/v) and chitosan concentration (2; 3; 4 mg/ml). The optimum enzyme concentrations were determined as 1.5mg/ml for A and 1.0mg/ml for B. The other optimum conditions were found 2.0% (w/v) for alginate concentration (both A and B); 3.0mg/ml for chitosan concentration (B) and 2.0% (v/v) for glutaraldehyde concentration (A). The optimum temperature (20-60°C), optimum pH (3.0-10.0), kinetic parameters, thermal stability (4-70°C), pH stability (4.0-9.0), operational stability (0-230 min) and reusability (20 times) were investigated for characterization. The optimum temperatures were 30°C (A), 40°C (B) and 35°C (soluble). The temperature profiles of the immobilized ureases were spread over a large area. The optimum pH values for the soluble urease and immobilized urease prepared by using methods (A) and (B) were found to be 7.5, 7.0, 7.0, respectively. The thermal stabilities of immobilized enzyme sets were studied and they maintained 50% activity at 65°C. However, at this temperature free urease protected only 15% activity. Copyright © 2014 Elsevier B.V. All rights reserved.

Pressure ulcers from spinal immobilization in trauma patients: a systematic review.

Science.gov (United States)

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

2014-04-01

To protect the (possibly) injured spine, trauma patients are immobilized on backboard or vacuum mattress, with a cervical collar, lateral headblocks, and straps. Several studies identified pressure ulcer (PU) development from these devices. The aim of this literature study was to gain insight into the occurrence and development of PUs, the risk factors, and the possible interventions to prevent PUs related to spinal immobilization with devices in adult trauma patients. We systematically searched PubMed (MEDLINE), EMBASE, Cochrane, and CINAHL for the period 1970 to September 2011. Studies were included if participants were healthy volunteers under spinal immobilization or trauma patients under spinal immobilization until spine injuries were diagnosed or excluded. Outcomes of primary interest included occurrence, severity, and risk for PU development as well as prevention of PU development related to spinal immobilization devices. The results of included studies show an incidence of collar-related PUs ranging from 6.8% to 38%. Described locations are the occiput, chin, shoulders, and back. The severity of these PUs varies between Stages 1 and 3, and one study describes PUs requiring surgical debridement, indicating a Stage 4 PU. Described risk factors for PU development are high pressure and pain from immobilizing devices, the length of time in/on a device, intensive care unit admission, high Injury Severity Scores (ISSs), mechanical ventilation, and intracranial pressure monitoring. Preventive interventions for collar-related PUs include early replacement of the extrication collar and regular skin assessment, collar refit, and position change. The results from this systematic review show that immobilization with devices increases the risk for PU development. This risk is demonstrated in nine experimental studies with healthy volunteers and in four clinical studies. Systematic review, level III.

Removal of strontium ions by immobilized saccharomyces cerevisiae in magnetic chitosan microspheres

Energy Technology Data Exchange (ETDEWEB)

Yin, Yanan; Wang, Jian Long; Yang, Xiao Yong; Li, Weihua [Collaborative Innovation Center for Advanced Nuclear Energy Technology, Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing (China)

2017-02-15

A novel biosorbent, immobilized Saccharomyces cerevisiae in magnetic chitosan microspheres was prepared, characterized, and used for the removal of Sr{sup 2+} from aqueous solution. The structure and morphology of immobilized S. cerevisiae before and after Sr{sup 2+}adsorption were observed using scanning electron microscopy with energy dispersive X-ray spectroscopy. The experimental results showed that the Langmuir and Freundlich isotherm models could be used to describe the Sr{sup 2+} adsorption onto immobilized S. cerevisiae microspheres. The maximal adsorption capacity (q{sub m}) was calculated to be 81.96 mg/g by the Langmuir model. Immobilized S. cerevisiae was an effective adsorbent for the Sr{sup 2+} removal from aqueous solution.

Enhanced bio-decolorization of azo dyes by co-immobilized quinone-reducing consortium and anthraquinone

DEFF Research Database (Denmark)

Su, YY; Zhang, Yifeng; Wang, J

2009-01-01

In the present study, the accelerating effect of co-immobilized anthraquinone and quinone-reducing consortium was investigated in the bio-decolorization process. The anthraquinone and quinone-reducing consortium were co-immobilized by entrapment in calcium alginate. The co-immobilized beads...

Hyaluronan Immobilized Polyurethane as a Blood Contacting Material

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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.

Enzymatic removal of phenol and p-chlorophenol in enzyme reactor: Horseradish peroxidase immobilized on magnetic beads

International Nuclear Information System (INIS)

Bayramoglu, Guelay; Arica, M. Yakup

2008-01-01

Horseradish peroxidase was immobilized on the magnetic poly(glycidylmethacrylate-co-methylmethacrylate) (poly(GMA-MMA)), via covalent bonding and used for the treatment of phenolic wastewater in continuous systems. For this purposes, horseradish peroxidase (HRP) was covalently immobilized onto magnetic poly(GMA-MMA) beds using glutaraldehyde (GA) as a coupling agent. The maximum HRP immobilization capacity of the magnetic poly(GMA-MMA)-GA beads was 3.35 mg g -1 . The immobilized HRP retained 79% of the activity of the free HRP used for immobilization. The immobilized HRP was used for the removal of phenol and p-chlorophenol via polymerization of dissolved phenols in the presence of hydrogen peroxide (H 2 O 2 ). The effect of pH and temperature on the phenol oxidation rate was investigated. The results were compared with the free HRP, which showed that the optimum pH value for the immobilized HRP is similar to that for the free HRP. The optimum pH value for free and immobilized HRP was observed at pH 7.0. The optimum temperature for phenols oxidation with immobilized HRP was between 25 and 35 deg. C and the immobilized HRP has more resistance to temperature inactivation than that of the free form. Finally, the immobilized HRP was operated in a magnetically stabilized fluidized bed reactor, and phenols were successfully removed in the enzyme reactor

Effective immobilization of DNA for development of polypyrrole nanowires based biosensor

Energy Technology Data Exchange (ETDEWEB)

Tran, Thi Luyen; Chu, Thi Xuan, E-mail: xuan@itims.edu.vn; Huynh, Dang Chinh; Pham, Duc Thanh; Luu, Thi Hoai Thuong; Mai, Anh Tuan, E-mail: tuan.maianh@hust.edu.vn

2014-09-30

Highlights: • Effective technique to immobilize probe DNA to the conducting polymer Polypyrrole nanowires (PPy NWs). • The PPy-NWs were electrochemically synthesized on the surface of the Pt electrodes using gelatin as the soft mold. • The DNA probe sequences were immobilized easily on the PPy NWs/Pt electrode using the adsorption method. • The DNA sensor has a low detection limit. - Abstract: This paper reports an easy technique for immobilization of the DNA to the conducting polymer polypyrrole nanowires (PPy NWs). The nanowires were electrochemically synthesized on the surface of working electrode in the presence of gelatin as a soft mold. The structure of obtained PPy NWs was investigated by Scanning Electron Microscopy (SEM), Fourier Transform Infrared (FTIR) spectroscopy and Surface Enhanced Raman Spectroscopy (SERS). The DNA strands were directly immobilized on the PPy NWs. The amino groups at the up-end of the PPy nanowires facilitate the linkage with the phosphate groups of the probe DNA. The DNA immobilization and hybridization were characterized by Electrochemical Impedance Spectroscopy (EIS). The initial results show that the sensor responses to 10 pM of DNA sequence in the solution.

Immobilization of Lead from Pb-Contaminated Soil Amended with Peat Moss

Directory of Open Access Journals (Sweden)

Seul-Ji Lee

2013-01-01

Full Text Available Immobilization of lead (Pb using soil amendments can reduce Pb toxicity and bioavailability in soil. This study evaluated Pb immobilization in a Pb-contaminated soil by using peat moss through various tests. The Pb-contaminated soil (2000 mg Pb·kg−1 was amended with 1%, 5%, and 10% of peat moss to immobilize Pb in the soil. The immobilization properties of Pb in the contaminated soil were evaluated by a column leaching experiment, a microcosm test, and a batch incubation test. Peat moss significantly reduced the Pb leaching in all of the experiments and more effectively reduced mobility and toxicity of Pb in the column leaching and microcosm tests than bioavailability in the batch incubation test. The immobilized lead from the soils amended with 1%, 5%, and 10% of peat moss was 37.9%, 87.1%, and 95.4% from the column leaching test, 18.5%, 90.9%, and 96.4% from the microcosm test, and 2.0%, 36.9%, and 57.9% from the NH4NO3 extraction method, respectively, indicating that peat moss can be effectively used for the remediation of Pb-contaminated soil.

Biological methanol production by immobilized Methylocella tundrae using simulated biohythane as a feed.

Science.gov (United States)

Patel, Sanjay K S; Singh, Raushan K; Kumar, Ashok; Jeong, Jae-Hoon; Jeong, Seong Hun; Kalia, Vipin C; Kim, In-Won; Lee, Jung-Kul

2017-10-01

Biohythane may be used as an alternative feed for methanol production instead of costly pure methane. In this study, methanol production potential of Methylocella tundrae immobilized through covalent immobilization, adsorption, and encapsulation was evaluated. Cells covalently immobilized on groundnut shells and chitosan showed a relative methanol production potential of 83.9 and 91.6%, respectively, compared to that of free cells. The maximum methanol production by free cells and cells covalently immobilized on groundnut shells and chitosan was 6.73, 6.20, and 7.23mM, respectively, using simulated biohythane as a feed. Under repeated batch conditions of eight cycles, cells covalently immobilized on chitosan and groundnut shells, and cells encapsulated in sodium-alginate resulted in significantly higher cumulative methanol production of 37.76, 31.80, and 25.58mM, respectively, than free cells (18.57mM). This is the first report on immobilization of methanotrophs on groundnut shells and its application in methanol production using biohythane as a feed. Copyright © 2017 Elsevier Ltd. All rights reserved.

The removal of thermo-tolerant coliform bacteria by immobilized waste stabilization pond algae.

Science.gov (United States)

Pearson, H W; Marcon, A E; Melo, H N

2011-01-01

This study investigated the potential of laboratory- scale columns of immobilized micro-algae to disinfect effluents using thermo-tolerant coliforms (TTC) as a model system. Cells of a Chlorella species isolated from a waste stabilization pond complex in Northeast Brazil were immobilized in calcium alginate, packed into glass columns and incubated in contact with TTC suspensions for up to 24 hours. Five to six log removals of TTC were achieved in 6 hours and 11 log removals in 12 hours contact time. The results were similar under artificial light and shaded sunlight. However little or no TTC removal occurred in the light in columns of alginate beads without immobilized algae present or when the immobilized algae were incubated in the dark suggesting that the presence of both algae and light were necessary for TTC decay. There was a positive correlation between K(b) values for TTC and increasing pH in the effluent from the immobilized algal columns within the range pH 7.2 and 8.9. The potential of immobilized algal technology for wastewater disinfection may warrant further investigation.

Radiation-induced polymerization for the immobilization of penicillin acylase

International Nuclear Information System (INIS)

Boccu, E.; Carenza, M.; Lora, S.; Palma, G.; Veronese, F.M.

1987-01-01

The immobilization of Escherichia coli penicillin acylase was investigated by radiation-induced polymerization of 2-hydroxyethyl methacrylate at low temperature. A leak-proof composite that does not swell in water was obtained by adding the cross-linking agent trimethylolpropane trimethacrylate to the monomer-aqueous enzyme mixture. Penicillin acylase, which was immobilized with greater than 70% yield, possessed a higher Km value toward the substrate 6-nitro-3-phenylacetamidobenzoic acid than the free enzyme form (Km = 1.7 X 10(-5) and 1 X 10(-5) M, respectively). The structural stability of immobilized penicillin acylase, as assessed by heat, guanidinium chloride, and pH denaturation profiles, was very similar to that of the free-enzyme form, thus suggesting that penicillin acylase was entrapped in its native state into aqueous free spaces of the polymer matrix

Nano-Immobilized Biocatalysts for Biodiesel Production from Renewable and Sustainable Resources

Directory of Open Access Journals (Sweden)

Keon Hee Kim

2018-02-01

Full Text Available The cost of biodiesel production relies on feedstock cost. Edible oil is unfavorable as a biodiesel feedstock because of its expensive price. Thus, non-edible crop oil, waste oil, and microalgae oil have been considered as alternative resources. Non-edible crop oil and waste cooking oil are more suitable for enzymatic transesterification because they include a large amount of free fatty acids. Recently, enzymes have been integrated with nanomaterials as immobilization carriers. Nanomaterials can increase biocatalytic efficiency. The development of a nano-immobilized enzyme is one of the key factors for cost-effective biodiesel production. This paper presents the technology development of nanomaterials, including nanoparticles (magnetic and non-magnetic, carbon nanotubes, and nanofibers, and their application to the nano-immobilization of biocatalysts. The current status of biodiesel production using a variety of nano-immobilized lipase is also discussed.

Enhancing the functional properties of thermophilic enzymes by chemical modification and immobilization.

Science.gov (United States)

Cowan, Don A; Fernandez-Lafuente, Roberto

2011-09-10

The immobilization of proteins (mostly typically enzymes) onto solid supports is mature technology and has been used successfully to enhance biocatalytic processes in a wide range of industrial applications. However, continued developments in immobilization technology have led to more sophisticated and specialized applications of the process. A combination of targeted chemistries, for both the support and the protein, sometimes in combination with additional chemical and/or genetic engineering, has led to the development of methods for the modification of protein functional properties, for enhancing protein stability and for the recovery of specific proteins from complex mixtures. In particular, the development of effective methods for immobilizing large multi-subunit proteins with multiple covalent linkages (multi-point immobilization) has been effective in stabilizing proteins where subunit dissociation is the initial step in enzyme inactivation. In some instances, multiple benefits are achievable in a single process. Here we comprehensively review the literature pertaining to immobilization and chemical modification of different enzyme classes from thermophiles, with emphasis on the chemistries involved and their implications for modification of the enzyme functional properties. We also highlight the potential for synergies in the combined use of immobilization and other chemical modifications. Copyright © 2011 Elsevier Inc. All rights reserved.

The effectiveness of immobilization during prostate irradiation

International Nuclear Information System (INIS)

Bentel, Gunilla C.; Marks, Lawrence B.; Sherouse, George W.; Spencer, David P.; Anscher, Mitchell S.

1995-01-01

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

Studeis on the immobilization of water soluble phosphatic fertilizer in some soils with 32P

International Nuclear Information System (INIS)

Zhang Yumei; Li Rensheng; Xu Xinyu

1985-01-01

Using superphosphate lablled with 32 P, we studied immobilization of water-soluble phosphatic fertilizer on 12 typies of soil. The experimental result showed that major factors to govern immobilization of water-soluble phosphatic fertilizer are: quickly availible Fe that showed positive correlation with the immobilization when it was 4.64-65.72 ppm; and pH that showed negative correlation with the immobilization when it was between 5.35 and 8.88. CaCO 3 and organic matter showed a great effect on the immobilization though there wasn't obvious correlation among them

Improved Performance of Pseudomonas fluorescens lipase by covalent immobilization onto Amberzyme

NARCIS (Netherlands)

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

2013-01-01

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

Preparation and photocatalytic activity of immobilized composite photocatalyst (titania nanoparticle/activated carbon)

International Nuclear Information System (INIS)

Mahmoodi, Niyaz Mohammad; Arami, Mokhtar; Zhang, Jason

2011-01-01

Research highlights: → Dyes were decolorized and degraded using novel immobilized composite photocatalyst. → Formate, acetate and oxalate anions were detected as dominant aliphatic intermediates where, they were further oxidized slowly to CO 2 . → Nitrate, chloride and sulfate anions were detected as the photocatalytic mineralization products of dyes. → Novel immobilized composite photocatalyst is the most effective novel immobilized composite photocatalyst to degrade of textile dyes. - Abstract: An immobilized composite photocatalyst, titania (TiO 2 ) nanoparticle/activated carbon (AC), was prepared and its photocatalytic activity on the degradation of textile dyes was tested. AC was prepared using Canola hull. Basic Red 18 (BR18) and Basic Red 46 (BR46) were used as model dyes. Fourier transform infrared (FTIR), wavelength dispersive X-ray spectroscopy (WDX), scanning electron microscopy (SEM), UV-vis spectrophotometry, chemical oxygen demand (COD) and ion chromatography (IC) analyses were employed. The effects of reaction parameters such as weight percent (wt.%) of activated carbon, pH, dye concentration and anions (NO 3 - , Cl - , SO 4 2- , HCO 3 - and CO 3 2- ) were investigated on dye degradation. Data showed that dyes were decolorized and degraded using novel immobilized composite photocatalyst. Formate, acetate and oxalate anions were detected as dominant aliphatic intermediates where, they were further oxidized slowly to CO 2 . Nitrate, chloride and sulfate anions were detected as the photocatalytic mineralization products of dyes. Results show that novel immobilized composite photocatalyst with 2 wt.% of AC is the most effective novel immobilized composite photocatalyst to degrade of textile dyes.

Influence of recent immobilization and recent surgery on mortality in patients with pulmonary embolism.

Science.gov (United States)

Nauffal, D; Ballester, M; Reyes, R Lopez; Jiménez, D; Otero, R; Quintavalla, R; Monreal, M

2012-09-01

The influence of recent immobilization or surgery on mortality in patients with pulmonary embolism (PE) is not well known. We used the Registro Informatizado de Enfermedad TromboEmbólica (RIETE) data to compare the 3-month mortality rate in patients with PE, with patients categorized according to the presence of recent immobilization, recent surgery, or neither. Of 18,028 patients with PE, 4169 (23%) had recent immobilization, 2212 (12%) had recent surgery, and 11,647 (65%) had neither. The all-cause mortality was 10.0% (95% confidence interval [CI] 9.5-10.4), and the PE-related mortality was 2.6% (95% CI 2.4-2.9). One in every two patients who died from PE had recent immobilization (43%) or recent surgery (6.7%). Only 25% of patients with immobilization had received prophylaxis, as compared with 65% of the surgical patients. Fatal PE was more common in patients with recent immobilization (4.9%; 95% CI 4.3-5.6) than in those with surgery (1.4%; 95% CI 1.0-2.0) or those with neither (2.1%; 95% CI 1.8-2.3). On multivariate analysis, patients with immobilization were at increased risk for fatal PE (odds ratio 2.2; 95% CI 1.8-2.7), with no differences being seen between patients immobilized in hospital or in the community. Forty-three per cent of patients dying from PE had recent immobilization for ≥4 days. Many of these deaths could have been prevented. © 2012 International Society on Thrombosis and Haemostasis.

Immobilization of spent resin with epoxy resin

International Nuclear Information System (INIS)

Gultom, O.; Suryanto; Sayogo; Ramdan

1997-01-01

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 137 Cs from waste product was not detected in experiment (author)

Influence of cosolvents on the hydrophobic surface immobilization topography of Candida antarctica lipase B

Science.gov (United States)

The presence of cosolvents and co-solutes during the immobilization of lipases on hydrophobic supports may influence the extent of lipase immobilization and the long-term catalytic stability of the biocatalyst. Candida antarctica B lipase immobilization was examined on a hydrophobic surface, i.e., ...

Stabilization of dimeric β-glucosidase from Aspergillus niger via glutaraldehyde immobilization under different conditions.

Science.gov (United States)

Vazquez-Ortega, Perla Guadalupe; Alcaraz-Fructuoso, Maria Teresa; Rojas-Contreras, Juan A; López-Miranda, Javier; Fernandez-Lafuente, Roberto

2018-03-01

The dimeric enzyme β-glucosidase from Aspergillus niger has been immobilized on different amino-agarose beads at pH 5 and 7, exploiting the versatility of glutaraldehyde. The stability of the free enzyme depended on enzyme concentration. Immobilization via ion exchange improved enzyme stability/activity, depending on the immobilization pH. However, the enzyme was desorbed in 75 mM NaCl at pH 7 and some stability/enzyme concentration dependence still existed. of these biocatalysts with glutaraldehyde increased enzyme stability (e.g. at pH 5, after incubation under conditions where the enzyme just ionically exchanged was fully inactivated, the activity of the glutaraldehyde treated enzyme remained unaltered). Immobilization on glutaraldehyde pre-activated supports yielded a higher increase in enzyme activity, but the stabilization was lower. While when measuring the enzyme activity at pH 4 there were no changes after immobilization, all immobilized enzymes were more active than the free enzyme at pH 6 and 7 (2-3 times). The Ki/Km ratio did not significantly decrease in any immobilized biocatalysts, and in some cases it worsened in a significant way (by a 9 fold factor using preactivated supports). The new biocatalysts are significantly more stable and avoid enzyme subunit desorption, being the immobilization pH a key point in their design. Copyright © 2017 Elsevier Inc. All rights reserved.

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.)

Immobilization of radioactive strontium in contaminated soils by phosphate treatment

International Nuclear Information System (INIS)

Kim, K.H.; Ammons, J.T.

1990-01-01

The feasibility of in situ phosphate- and metal- (calcium, aluminum, and iron) solution treatment for 90 Sr immobilization was investigated. Batch and column experiments were performed to find optimum conditions for coprecipitation of 90 Sr with Ca-, Al-, and Fe-phosphate compounds in contaminated soils. Separate columns were packed with artificially 85 Sr-contaminated acid soil as well as 90 Sr-contaminated soil from the Oak Ridge Reservation. After metal-phosphate treatment, the columns were then leached successively with either tapwater or 0.001 M CaCl 2 solution. Most of the 85 Sr coprecipitated with the metal phosphate compounds. Immobilization of 85 Sr and 90 Sr was affected by such factors as solution pH, metal and phosphate concentration, metal-to-phosphate ratio, and soil characteristics. Equilibration time after treatments also affected 85 Sr immobilization. Many technology aspects still need to be investigated before field applications are feasible, but these experiments indicate that phosphate-based in situ immobilization should prevent groundwater contamination and will be useful as a treatment technology for 90 Sr-contaminated sites. 15 refs., 3 figs., 1 tab

Study on the immobilization of alpha-amylase by radiation-induced polymerization at low-temperature, (2)

International Nuclear Information System (INIS)

Yoshida, Masaru; Kumakura, Minoru; Kaetsu, Isao

1975-07-01

The immobilization α-amylase in low concentration (50-250μg) by radiation induced polymerization at low temperature, with HEMA has been studied. The immobilization was performed in the temperature range of -196 0 C to +40 0 C. Activity of the immobilized enzyme decreases at temperatures above 0 0 C. The optimum temperatures for immobilization of α-amylase are -78 0 C - -24 0 C, where only the polymerization by irradiation is effective. HEMA is a suitable monomer as the immobilization carrier, because of its high polymerization rate of 100% in the temperature range. The suitable concentration of HEMA is less than 30%, and above this concentration the activity of enzyme decreases considerably. The optimum irradiation dose for immobilization is 1 x 10 6 R, and the activity of enzyme decreases at 5 x 10 6 R. The polymerization composition is porous gel structure, so the enzymatic reaction can be carried out merely by introducing a substrate to the composition. The activity attained in the immobilized enzyme is 75-80% that of the native α-amylase. The immobilized enzyme is more heat-resistant than the native one. (auth.)

The mechanisms of heavy metal immobilization by cementitious material treatments and thermal treatments: A review.

Science.gov (United States)

Guo, Bin; Liu, Bo; Yang, Jian; Zhang, Shengen

2017-05-15

Safe disposal of solid wastes containing heavy metals is a significant task for environment protection. Immobilization treatment is an effective technology to achieve this task. Cementitious material treatments and thermal treatments are two types of attractive immobilization treatments due to that the heavy metals could be encapsulated in their dense and durable wasteforms. This paper discusses the heavy metal immobilization mechanisms of these methods in detail. Physical encapsulation and chemical stabilization are two fundamental mechanisms that occur simultaneously during the immobilization processes. After immobilization treatments, the wasteforms build up a low permeable barrier for the contaminations. This reduces the exposed surface of wastes. Chemical stabilization occurs when the heavy metals transform into more stable and less soluble metal bearing phases. The heavy metal bearing phases in the wasteforms are also reviewed in this paper. If the heavy metals are incorporated into more stable and less soluble metal bearing phases, the potential hazards of heavy metals will be lower. Thus, converting heavy metals into more stable phases during immobilization processes should be a common way to enhance the immobilization effect of these immobilization methods. Copyright © 2017 Elsevier Ltd. All rights reserved.

Recent advances in covalent, site-specific protein immobilization [version 1; referees

DEFF Research Database (Denmark)

Meldal, Morten Peter; Schoffelen, Sanne

2016-01-01

The properties of biosensors, biomedical implants, and other materials based on immobilized proteins greatly depend on the method employed to couple the protein molecules to their solid support. Covalent, site-specific immobilization strategies are robust and can provide the level of control...

Implementation of immobilization accessories for positioning of small animals for radiation therapy

International Nuclear Information System (INIS)

Vettorato, M.C.; Girotto, C.H.; Fogaça, J.L.; Vulcano, L.C.; Fernandes, M.A.R.

2017-01-01

Radiation therapy is a modality that is presenting great advances in veterinary medicine worldwide. In Brazil, this therapeutic option is underachieved. The success of this method depends on several factors, including the use of appropriate accessories for protection and immobilization of patients. For the immobilization of small animals during treatment, in addition to sedation and anesthesia, immobilizing accessories, similar to those used in human radiotherapy, are used. This study aimed to present proposals for immobilizing accessories adapted to the positioning of small animals in order to be used in radiotherapy planning. In order to achieve results, accessories were made and tested in a living animal simulating a radiotherapy planning, which proved to be favorable to use in positioning small animals undergoing radiotherapy and for implementation processes. (author)

Implementation of immobilization accessories for positioning of small animals for radiation therapy

Energy Technology Data Exchange (ETDEWEB)

Vettorato, M.C.; Girotto, C.H.; Fogaça, J.L.; Vulcano, L.C.; Fernandes, M.A.R., E-mail: m_vettorato@hotmail.com [Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP), Botucatu, SP (Brazil)

2017-11-15

Radiation therapy is a modality that is presenting great advances in veterinary medicine worldwide. In Brazil, this therapeutic option is underachieved. The success of this method depends on several factors, including the use of appropriate accessories for protection and immobilization of patients. For the immobilization of small animals during treatment, in addition to sedation and anesthesia, immobilizing accessories, similar to those used in human radiotherapy, are used. This study aimed to present proposals for immobilizing accessories adapted to the positioning of small animals in order to be used in radiotherapy planning. In order to achieve results, accessories were made and tested in a living animal simulating a radiotherapy planning, which proved to be favorable to use in positioning small animals undergoing radiotherapy and for implementation processes. (author)

Capture and immobilization of krypton-85

International Nuclear Information System (INIS)

Whitmell, D.S.; Geens, L.; Penzhorn, R.D.; Smith, M.J.S.

1985-01-01

It may become necessary to contain the krypton-85 released from nuclear fuel during reprocessing in order to reduce the exposure to the local population and the radioactive background throughout the world. A brief description is given of studies being carried out in the Indirect Action Programme. The separation of krypton from other off-gases by cryogenic distillation in the presence of oxygen is being studied at SCK/CEN Mol, together with the behavior of ozone in the distillation column. Two processes for the immobilization of krypton in solid forms have been successfully developed and demonstrated. At KfK Karlsruhe, krypton is encapsulated in vitrified zeolites; at AERE Harwell, krypton is immobilized within a metallic matrix. These processes offer excellent gas retention and either could be adopted for a reprocessing plant

Studies on the preparation of immobilized enzymes by radio-polymerization, 10

International Nuclear Information System (INIS)

Amarakone, S.P.; Hayashi, Toru; Kawashima, Koji.

1983-01-01

β-Galactosidase of E. coli origin was immobilized in the form of beads by the radiopolymerization of different combinations of monomers using a gamma irradiation technique. With the dialysed enzyme, recoveries of over 300 % could be obtained on suitable monomer combinations containing magnesium and sodium acrylates. The recovery of the enzyme also depended on the irradiation time. The immobilized enzyme had better pH and temperature stability and was less affected by the presence of metal ions in the medium, compared to the native enzyme. The optimum pH and temperatures of the immobilized enzyme were different from those of the native enzyme and were 7.0 to 7.5 and 50 deg C respectively. The immobilized enzyme was used in a column for the continuous determination of lactose with a standard type autoanalyser. Good linearity could be observed even up to 3 % lactose in the sample. (author)

Application and use of spinal immobilization devices in zero-gravity flight

Science.gov (United States)

Krupa, Debra T.; Gosbee, John; Billica, Roger; Boyce, Joey B.

1991-01-01

A KC-135 parabolic flight was performed for the purpose of evaluation of spinal immobilization techniques in microgravity. The flight followed the standard 40 parabola profile with four NASA/KRUG experimenters involved. One performed as coordinator/recorder, one as test subject, and two as the Crew Medical Officers (CMO). The flight was to evaluate the application of spinal immobilization devices and techniques in microgravity as are performed during initial stabilization or patient transport scenarios. The sequence of detail for examination of the following objectives included: attempted cervical spine immobilization with all free floating, the patient restrained to the floor, various hand positioning techniques; c-collar placement; Kendrick Extrication Device (KED) application with various restraints for patient and CMO; patient immobilization and transport using the KED; patient transported on KED and spine board. Observations for each task are included. Major conclusions and issues are also included.

NCBI nr-aa BLAST: CBRC-DRER-14-0059 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-DRER-14-0059 ref|YP_683352.1| hypothetical protein RD1_3158 [Roseobacter denit...rificans OCh 114] gb|ABG32666.1| conserved hypothetical protein [Roseobacter denitrificans OCh 114] YP_683352.1 2.5 41% ...

NCBI nr-aa BLAST: CBRC-DRER-26-0529 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-DRER-26-0529 ref|YP_683352.1| hypothetical protein RD1_3158 [Roseobacter denit...rificans OCh 114] gb|ABG32666.1| conserved hypothetical protein [Roseobacter denitrificans OCh 114] YP_683352.1 2.5 41% ...

Drying of enzyme immobilized on eco-friendly supports | Costa-Silva ...

African Journals Online (AJOL)

Immobilized derivatives obtained had decreased enzyme activity (≈ 30.0%) during a storage period of six months; and retained an average of 50.0% of the initial activity after five reuse cycles. Water content in immobilized derivatives varied between 4.2 and 6.1% and the water activities ranged from 0.14 to 0.30. Key words: ...

Effects of toxic organic flotation reagent (aniline aerofloat) on an A/O submerged membrane bioreactor (sMBR): Microbial community dynamics and performance.

Science.gov (United States)

Lin, Weixiong; Sun, Shuiyu; Wu, Chun; Xu, Pingting; Ye, Ziwei; Zhuang, Shengwei

2017-08-01

Bio-treatment of flotation wastewater has been proven to be both effective and economical, as a treatment method. Despite this, little is known regarding the effects of toxic organic floatation reagents such as Dianilinodithiophosphoric acid (DDA), on the microbial community performance or dynamics, which are critical to the effective performance of the bio-treatment reactor. A submerged membrane bioreactor (sMBR) was constructed to continuously treat simulated wastewater contaminated with DDA, an organic flotation reagent that is now considered a significant pollutant. The performance of the sMBR system was investigated at different DDA loading concentrations, with assessment of the effects of DDA on the microbial communities within the sMBR, in particular the biodiversity and succession within the microbial community. Results showed that, with increased DDA loadings, the performance of the sMBR was initially negatively affected, but the system adapted efficiently and consistently reached a COD removal rate of up to 80%. Increased DDA loading concentrations had an adverse effect on the activity of both the activated sludge and microbial communities, resulting in a large alteration in microbial dynamics, especially during the start-up stage and the high DDA loading stage. Strains capable of adapting to the presence of DDA, capable of degrading DDA or utilizing its byproducts, were enriched within the sMBR community, such as Zoogloea, Clostridium, Sideroxydans lithotrophicus, Thiobacillus, Thauera amino aromatica and Alicycliphilus denitrificans. Copyright © 2017 Elsevier Inc. All rights reserved.

Biodegradation of different petroleum hydrocarbons by free and immobilized microbial consortia.

Science.gov (United States)

Shen, Tiantian; Pi, Yongrui; Bao, Mutai; Xu, Nana; Li, Yiming; Lu, Jinren

2015-12-01

The efficiencies of free and immobilized microbial consortia in the degradation of different types of petroleum hydrocarbons were investigated. In this study, the biodegradation rates of naphthalene, phenanthrene, pyrene and crude oil reached about 80%, 30%, 56% and 48% under the optimum environmental conditions of free microbial consortia after 7 d. We evaluated five unique co-metabolic substances with petroleum hydrocarbons, α-lactose was the best co-metabolic substance among glucose, α-lactose, soluble starch, yeast powder and urea. The orthogonal biodegradation analysis results showed that semi-coke was the best immobilized carrier followed by walnut shell and activated carbon. Meanwhile, the significance of various factors that contribute to the biodegradation of semi-coke immobilized microbial consortia followed the order of: α-lactose > semi-coke > sodium alginate > CaCl2. Moreover, the degradation rate of the immobilized microbial consortium (47%) was higher than that of a free microbial consortium (26%) under environmental conditions such as the crude oil concentration of 3 g L(-1), NaCl concentration of 20 g L(-1), pH at 7.2-7.4 and temperature of 25 °C after 5 d. SEM and FTIR analyses revealed that the structure of semi-coke became more porous and easily adhered to the microbial consortium; the functional groups (e.g., hydroxy and phosphate) were identified in the microbial consortium and were changed by immobilization. This study demonstrated that the ability of microbial adaptation to the environment can be improved by immobilization which expands the application fields of microbial remediation.

Geometry-dependent DNA-TiO2 immobilization mechanism: A spectroscopic approach

Science.gov (United States)

Silva-Moraes, M. O.; Garcia-Basabe, Y.; de Souza, R. F. B.; Mota, A. J.; Passos, R. R.; Galante, D.; Fonseca Filho, H. D.; Romaguera-Barcelay, Y.; Rocco, M. L. M.; Brito, W. R.

2018-06-01

DNA nucleotides are used as a molecular recognition system on electrodes modified to be applied in the detection of various diseases, but immobilization mechanisms, as well as, charge transfers are not satisfactorily described in the literature. An electrochemical and spectroscopic study was carried out to characterize the molecular groups involved in the direct immobilization of DNA structures on the surface of nanostructured TiO2 with the aim of evaluating the influence of the geometrical aspects. X-ray photoelectron spectroscopy at O1s and P2p core levels indicate that immobilization of DNA samples occurs through covalent (Psbnd Osbnd Ti) bonds. X-ray absorption spectra at the Ti2p edge reinforce this conclusion. A new species at 138.5 eV was reported from P2p XPS spectra analysis which plays an important role in DNA-TiO2 immobilization. The Psbnd Osbnd Ti/Osbnd Ti ratio showed that quantitatively the DNA immobilization mechanism is dependent on their geometry, becoming more efficient for plasmid ds-DNA structures than for PCR ds-DNA structures. The analysis of photoabsorption spectra at C1s edge revealed that the molecular groups that participate in the C1s → LUMO electronic transitions have different pathways in the charge transfer processes at the DNA-TiO2 interface. Our results may contribute to additional studies of immobilization mechanisms understanding the influence of the geometry of different DNA molecules on nanostructured semiconductor and possible impact to the charge transfer processes with application in biosensors or aptamers.

TiO2 beads and TiO2-chitosan beads for urease immobilization

International Nuclear Information System (INIS)

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

2014-01-01

The aim of the present study is to synthesize TiO 2 beads for urease immobilization. Two different strategies were used to immobilize the urease on TiO 2 beads. In the first method (A), urease enzyme was immobilized onto TiO 2 beads by adsorption and then crosslinking. In the second method (B), TiO 2 beads were coated with chitosan-urease mixture. To determine optimum conditions of immobilization, different parameters were investigated. The parameters of optimization were initial enzyme concentration (0.5; 1; 1.5; 2 mg/ml), alginate concentration (1; 2; 3%), glutaraldehyde concentration (1; 2; 3% v/v) and chitosan concentration (2; 3; 4 mg/ml). The optimum enzyme concentrations were determined as 1.5 mg/ml for A and 1.0 mg/ml for B. The other optimum conditions were found 2.0% (w/v) for alginate concentration (both A and B); 3.0 mg/ml for chitosan concentration (B) and 2.0% (v/v) for glutaraldehyde concentration (A). The optimum temperature (20-60 °C), optimum pH (3.0-10.0), kinetic parameters, thermal stability (4–70 °C), pH stability (4.0-9.0), operational stability (0-230 min) and reusability (20 times) were investigated for characterization. The optimum temperatures were 30 °C (A), 40 °C (B) and 35 °C (soluble). The temperature profiles of the immobilized ureases were spread over a large area. The optimum pH values for the soluble urease and immobilized urease prepared by using methods (A) and (B) were found to be 7.5, 7.0, 7.0, respectively. The thermal stabilities of immobilized enzyme sets were studied and they maintained 50% activity at 65 °C. However, at this temperature free urease protected only 15% activity. - Highlights: • TiO 2 and TiO 2 -chitosan beads for urease immobilization have been prepared and characterized. • The beads used in this work are good matrices for the immobilization of urease. • The immobilized urease was shown to have good properties and stabilities (pH and thermal stability, operational stability). • The 50

A new method of lower extremity immobilization in radiotherapy

International Nuclear Information System (INIS)

Zheng, Xuhai; Dai, Tangzhi; Shu, Xiaochuan; Pu, Yuanxue; Feng, Gang; Li, Xuesong; Liao, Dongbiao; Du, Xiaobo

2012-01-01

We developed a new method for immobilization of the fix lower extremities by using a thermoplastic mask, a carbon fiber base plate, a customized headrest, and an adjustable angle holder. The lower extremities of 11 patients with lower extremity tumors were immobilized by this method. CT simulation was performed for each patient. For all 11 patients, the device fit was suitable and comfortable and had good reproducibility, which was proven in daily radiotherapy

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

Immobilization of Fab' fragments onto substrate surfaces: A survey of methods and applications.

Science.gov (United States)

Crivianu-Gaita, Victor; Thompson, Michael

2015-08-15

Antibody immobilization onto surfaces has widespread applications in many different fields. It is desirable to bind antibodies such that their fragment-antigen-binding (Fab) units are oriented away from the surface in order to maximize analyte binding. The immobilization of only Fab' fragments yields benefits over the more traditional whole antibody immobilization technique. Bound Fab' fragments display higher surface densities, yielding a higher binding capacity for the analyte. The nucleophilic sulfide of the Fab' fragments allows for specific orientations to be achieved. For biosensors, this indicates a higher sensitivity and lower detection limit for a target analyte. The last thirty years have shown tremendous progress in the immobilization of Fab' fragments onto gold, Si-based, polysaccharide-based, plastic-based, magnetic, and inorganic surfaces. This review will show the current scope of Fab' immobilization techniques available and illustrate methods employed to minimize non-specific adsorption of undesirables. Furthermore, a variety of examples will be given to show the versatility of immobilized Fab' fragments in different applications and future directions of the field will be addressed, especially regarding biosensors. Copyright © 2015 Elsevier B.V. All rights reserved.

NCBI nr-aa BLAST: CBRC-DRER-26-0448 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-DRER-26-0448 ref|YP_682608.1| hypothetical protein RD1_2346 [Roseobacter denit...rificans OCh 114] gb|ABG31922.1| conserved hypothetical protein [Roseobacter denitrificans OCh 114] YP_682608.1 2e-89 38% ...

NCBI nr-aa BLAST: CBRC-DDIS-03-0142 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-DDIS-03-0142 ref|YP_683041.1| 5-aminolevulinic acid synthase [Roseobacter deni...trificans OCh 114] gb|ABG32355.1| 5-aminolevulinic acid synthase [Roseobacter denitrificans OCh 114] YP_683041.1 1e-122 61% ...

Comparison of four supports for adsorption of reactive dyes by immobilized Aspergillus fumigatus beads

Institute of Scientific and Technical Information of China (English)

WANG Bao-e; HU Yong-you

2007-01-01

Four materials, sodium carboxymethylcellulose (Na-CMC), sodium alginate (SA), polyvinyl alcohol (PVA), and chitosan (CTS), were prepared as supports for entrapping fungus Aspergillus fumigatus. The adsorption of synthetic dyes, reactive brilliant blue KN-R, and reactive brilliant red K-2BP, by these immobilized gel beads and plain gel beads was evaluated. The adsorption efficiencies of reactive brilliant red K-2BP and reactive brilliant blue KN-R by CTS immobilized beads were 89.1% and 93.5% in 12 h, respectively. The adsorption efficiency by Na-CMC immobilized beads was slightly lower than that of mycelial pellets. But the dye culture mediums were almost completely decolorized in 48 h using the above-mentioned two immobilized beads (exceeding 95%). The adsorption efficiency by SA immobilized beads exceeded 92% in 48 h. PVA-SA immobilized beads showed the lowest adsorption efficiency, which was 79.8% for reactive brilliant red K-2BP and 92.5% for reactive brilliant blue KN-R in 48 h. Comparing the adsorption efficiency by plain gel beads, Na-CMC plain gel beads ranked next to CTS ones. SA and PVA-SA plain gel beads hardly had the ability of adsorbing dyes. Subsequently, the growth of mycelia in Na-CMC and SA immobilized beads were evaluated. The biomass increased continuously in 72 h. The adsorption capacity of reactive brilliant red K-2BP and reactive brilliant blue KN-R by Na-CMC immobilized beads was 78.0 and 86.7 mg/g, respectively. The SEM micrographs show that the surface structure of Na-CMC immobilized bead is loose and finely porous, which facilitates diffusion of the dyes.

Hydrolysis of whey lactose by immobilized β-Galactosidase

Directory of Open Access Journals (Sweden)

Marcela Panaro Mariotti

2008-12-01

Full Text Available Hydrolysis of whey lactose to glucose and galactose by immobilized galactosidase comes as an alternative to enlarge the possibilities of commercial use of this feedstock. To be applied at industrial scale, the process should be performed continuously .This work aimed to study the hydrolysis of whey lactose by an immobilized enzyme reactor. b-Galactosidase from Aspergillus oryzae was immobilized on silica and activity and stability were evaluated. The best immobilization results were attained by using glutaraldehyde as support's activator and enzyme stabilizer. The optimized enzyme proportion for immobilization was 15-20 mg g-1 of support. Treatments of whey were performed (microfiltration, thermal treatment and ultrafiltration, seeking the elimination of sludge, and the effects on operating the fixed bed reactor were evaluated. Ultrafiltration was the best treatment towards a proper substrate solution for feeding the reactor.A hidrólise de lactose de soro de leite, resultando em glicose e galactose, apresenta-se como uma alternativa para ampliar as possibilidades de uso comercial deste insumo. Para ser aplicado em escala industrial, o processo deve ser operado de modo contínuo. Reporta-se o estudo de um sistema objetivando hidrólise de lactose de soro de leite através de um reator com enzima imobilizada. b-Galactosidase de Aspergillus oryzae foi imobilizada em sílica, sendo avaliadas a estabilidade e atividade. Os melhores resultados de imobilização foram obtidos usando glutaraldeído como ativante do suporte e estabilizador da enzima. A proporção otimizada entre enzima e suporte foi 15-20 mg.g-1. Foram estudadas formas de tratamento do soro (microfiltração, tratamento térmico e ultrafiltração, objetivando eliminação de material suspenso, e avaliando os efeitos na operação de reator de leito fixo. A ultrafiltração foi o melhor tratamento, na busca de uma solução de substrato apropriada para o reator contínuo.

Immobilized Trienzymatic System with Enhanced Stabilization for the Biotransformation of Lactose

Directory of Open Access Journals (Sweden)

Pedro Torres

2017-02-01

Full Text Available The use of ketohexose isomerases is a powerful tool in lactose whey processing, but these enzymes can be very sensitive and expensive. Development of immobilized/stabilized biocatalysts could be a further option to improve the process. In this work, β-galactosidase from Bacillus circulans, l-arabinose (d-galactose isomerase from Enterococcus faecium, and d-xylose (d-glucose isomerase from Streptomyces rubiginosus were immobilized individually onto Eupergit C and Eupergit C 250 L. Immobilized activity yields were over 90% in all cases. With the purpose of increasing thermostability of derivatives, two post-immobilization treatments were performed: alkaline incubation to favor the formation of additional covalent linkages, and blocking of excess oxirane groups by reacting with glycine. The greatest thermostability was achieved when alkaline incubation was carried out for 24 h, producing l-arabinose isomerase-Eupergit C derivatives with a half-life of 379 h and d-xylose isomerase-Eupergit C derivatives with a half-life of 554 h at 50 °C. Preliminary assays using immobilized and stabilized biocatalysts sequentially to biotransform lactose at pH 7.0 and 50 °C demonstrated improved performances as compared with soluble enzymes. Further improvements in ketohexose productivities were achieved when the three single-immobilizates were incubated simultaneously with lactose in a mono-reactor system.

Conceptual process for immobilizing defense high level wastes in SYNROC-D

International Nuclear Information System (INIS)

Anon.

1981-01-01

It is believed that the immobilization of defense wastes in SYNROC-D possesses important advantages over an alternative process which involves immobilizing the sludges in borosilicate glass. (1) It is possible to immobilize about 3 times the weight of sludge in a given volume of SYNROC-D as compared to borosilicate glass. The costs of fabrications, transport and ultimate geologic storage are correspondingly reduced; (2) the mineral assemblage of SYNROC-D is vastly more stable in the presence of groundwaters than are borosilicate glasses. The long-lived actinide elements, in particular, are immobilized much more securely in SYNROC-D than in glass; and (3) SYNROC-D is composed of thermodynamically compatible phases which possess crystal structures identical to those of natural minerals which are known to have survived in geological environments at elevated pressures and temperatures for periods of 500 to 2000 million years and to have retained radioactive elements quantitatively for these periods despite strong radiation damage. It is this evidence, provided by nature herself, which can demonstrate to the community that the shorter times required for radwaste immobilization under the much less extreme pressure, temperature conditions present in a suitable geological repository can be successfully achieved. Glass, as a waste-form, is intrinsically incapable of providing this assurance

Flow-induced immobilization of glucose oxidase in nonionic micellar nanogels for glucose sensing.

Science.gov (United States)

Cardiel, Joshua J; Zhao, Ya; Tonggu, Lige; Wang, Liguo; Chung, Jae-Hyun; Shen, Amy Q

2014-10-21

A simple microfluidic platform was utilized to immobilize glucose oxidase (GOx) in a nonionic micellar scaffold. The immobilization of GOx was verified by using a combination of cryogenic electron microscopy (cryo-EM), scanning electron microscopy (SEM), and ultraviolet spectroscopy (UV) techniques. Chronoamperometric measurements were conducted on nanogel-GOx scaffolds under different glucose concentrations, exhibiting linear amperometric responses. Without impacting the lifetime and denaturation of GOx, the nonionic nanogel provides a favorable microenvironment for GOx in biological media. This flow-induced immobilization method in a nonionic nanogel host matrix opens up new pathways for designing a simple, fast, biocompatible, and cost-effective process to immobilize biomolecules that are averse to ionic environments.

Immobilizer-assisted management of metal-contaminated agricultural soils for safer food production.

Science.gov (United States)

Kim, Kwon-Rae; Kim, Jeong-Gyu; Park, Jeong-Sik; Kim, Min-Suk; Owens, Gary; Youn, Gyu-Hoon; Lee, Jin-Su

2012-07-15

Production of food crops on metal contaminated agricultural soils is of concern because consumers are potentially exposed to hazardous metals via dietary intake of such crops or crop derived products. Therefore, the current study was conducted to develop management protocols for crop cultivation to allow safer food production. Metal uptake, as influenced by pH change-induced immobilizing agents (dolomite, steel slag, and agricultural lime) and sorption agents (zeolite and compost), was monitored in three common plants representative of leafy (Chinese cabbage), root (spring onion) and fruit (red pepper) vegetables, in a field experiment. The efficiency of the immobilizing agents was assessed by their ability to decrease the phytoavailability of metals (Cd, Pb, and Zn). The fruit vegetable (red pepper) showed the least accumulation of Cd (0.16-0.29 mgkg(-1) DW) and Pb (0.2-0.9 mgkg(-1) DW) in edible parts regardless of treatment, indicating selection of low metal accumulating crops was a reasonable strategy for safer food production. However, safer food production was more likely to be achievable by combining crop selection with immobilizing agent amendment of soils. Among the immobilizing agents, pH change-induced immobilizers were more effective than sorption agents, showing decreases in Cd and Pb concentrations in each plant well below standard limits. The efficiency of pH change-induced immobilizers was also comparable to reductions obtained by 'clean soil cover' where the total metal concentrations of the plow layer was reduced via capping the surface with uncontaminated soil, implying that pH change-induced immobilizers can be practically applied to metal contaminated agricultural soils for safer food production. Copyright © 2012 Elsevier Ltd. All rights reserved.

Feeding response of sport fish after electrical immobilization, chemical sedation, or both

Science.gov (United States)

Meinertz, Jeffery R.; Fredricks, Kim T.; Ambrose, Ryan D.; Jackan, Leanna M.; Wise, Jeremy K.

2012-01-01

Fishery managers frequently capture wild fish for a variety of fishery management activities. Though some activities can be accomplished without immobilizing the fish, others are accomplished more readily, humanely, and safely (for both the handler and the fish) when fish are immobilized by physical (e.g., electrical immobilization) or chemical sedation. A concern regarding the use of chemical sedatives is that chemical residues may remain in the fillet tissue after the fish recovers from sedation. If those residues are harmful to humans, there is some risk that a postsedated fish released to public waters may be caught and consumed by an angler. To characterize this risk, a series of four trials were conducted. Three trials assessed feeding activity after hatchery-reared fish were electrically immobilized, chemically sedated, or both, and one trial assessed the likelihood of an angler catching a wild fish that had been electrically immobilized and chemically sedated. Results from the first trial indicated that the feeding activity of laboratory habituated fish was variable among and within species after electrical immobilization, chemical sedation, or both. Results from the second trial indicated that the resumption of feeding activity was rapid after being mildly sedated for 45 min. Results from the third trial indicated that the feeding activity of outdoor, hatchery-reared fish was relatively aggressive after fish had been chemically sedated. Results from the fourth trial indicated that the probability of capturing wild fish in a more natural environment by angling after fish had been electrically immobilized and chemically sedated is not likely, i.e., in a group of five fish caught, 3 out of 100 times one would be a fish that had been sedated.

Degradation of phenol and TCE using suspended and chitosan-bead immobilized Pseudomonas putida.

Science.gov (United States)

Chen, Yan-Min; Lin, Tsair-Fuh; Huang, Chih; Lin, Jui-Che; Hsieh, Feng-Ming

2007-09-30

The degradability of phenol and trichloroethene (TCE) by Pseudomonas putida BCRC 14349 in both suspended culture and immobilized culture systems are investigated. Chitosan beads at a size of about 1-2mm were employed to encapsulate the P. putida cells, becoming an immobilized culture system. The phenol concentration was controlled at 100 mg/L, and that of TCE was studied from 0.2 to 20 mg/L. The pH, between 6.7 and 10, did not affect the degradation of either phenol or TCE in the suspended culture system. However, it was found to be an important factor in the immobilized culture system in which the only significant degradation was observed at pH >8. This may be linked to the surface properties of the chitosan beads and its influence on the activity of the bacteria. The transfer yield of TCE on a phenol basis was almost the same for the suspended and immobilized cultures (0.032 mg TCE/mg phenol), except that these yields occurred at different TCE concentrations. The transfer yield at a higher TCE concentration for the immobilized system suggested that the cells immobilized in carriers can be protected from harsh environmental conditions. For kinetic rate interpretation, the Monod equation was employed to describe the degradation rates of phenol, while the Haldane's equation was used for TCE degradation. Based on the kinetic parameters obtained from the two equations, the rate for the immobilized culture systems was only about 1/6 to that of the suspended culture system for phenol degradation, and was about 1/2 for TCE degradation. The slower kinetics observed for the immobilized culture systems was probably due to the slow diffusion of substrate molecules into the beads. However, compared with the suspended cultures, the immobilized cultures may tolerate a higher TCE concentration as much less inhibition was observed and the transfer yield occurred at a higher TCE concentration.

Immobilization of Mitochondria on Graphene

Science.gov (United States)

2013-08-29

poly-L-lysine has also been reported for immobilization of yeast mitochondria. Coating was performed by repetitive washing of cover slips with 0.02...of Poly-L-lysine Applications of PLL PLL is a production of bacterial fermentation and is used as a food preservative. In biology, PLL is used in

NCBI nr-aa BLAST: CBRC-OPRI-01-0485 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-OPRI-01-0485 ref|YP_680544.1| magnesium chelatase subunit D [Roseobacter denit...rificans OCh 114] gb|ABG29858.1| magnesium-chelatase 60 kDa subunit [Roseobacter denitrificans OCh 114] YP_680544.1 0.003 28% ...

UniProt search blastx result: AK288277 [KOME

Lifescience Database Archive (English)

Full Text Available AK288277 J090017K16 Q160X3|RL11_ROSDO 50S ribosomal protein L11 - Roseobacter denit...rificans (strain ATCC 33942 / OCh 114) (Erythrobacter sp. (strain OCh 114)) (Roseobacter denitrificans) 7.00E-34 ...

UniProt search blastx result: AK288771 [KOME

Lifescience Database Archive (English)

Full Text Available AK288771 J090068A13 Q160Y1|RS12_ROSDO 30S ribosomal protein S12 - Roseobacter denit...rificans (strain ATCC 33942 / OCh 114) (Erythrobacter sp. (strain OCh 114)) (Roseobacter denitrificans) 2.00E-37 ...

UniProt search blastx result: AK288526 [KOME

Lifescience Database Archive (English)

Full Text Available AK288526 J090044E18 Q160Y1|RS12_ROSDO 30S ribosomal protein S12 - Roseobacter denit...rificans (strain ATCC 33942 / OCh 114) (Erythrobacter sp. (strain OCh 114)) (Roseobacter denitrificans) 1.00E-37 ...

Protic ionic liquid as additive on lipase immobilization using silica sol-gel.

Science.gov (United States)

de Souza, Ranyere Lucena; de Faria, Emanuelle Lima Pache; Figueiredo, Renan Tavares; Freitas, Lisiane dos Santos; Iglesias, Miguel; Mattedi, Silvana; Zanin, Gisella Maria; dos Santos, Onélia Aparecida Andreo; Coutinho, João A P; Lima, Álvaro Silva; Soares, Cleide Mara Faria

2013-03-05

Ionic liquids (ILs) have evolved as a new type of non-aqueous solvents for biocatalysis, mainly due to their unique and tunable physical properties. A number of recent review papers have described a variety of enzymatic reactions conducted in IL solutions, on the other hand, to improve the enzyme's activity and stability in ILs; major methods being explored include the enzyme immobilization (on solid support, sol-gel, etc.), protic ionic liquids used as an additive process. The immobilization of the lipase from Burkholderia cepacia by the sol-gel technique using protic ionic liquids (PIL) as additives to protect against inactivation of the lipase due to release of alcohol and shrinkage of the gel during the sol-gel process was investigated in this study. The influence of various factors such as the length of the alkyl chain of protic ionic liquids (monoethanolamine-based) and a concentration range between 0.5 and 3.0% (w/v) were evaluated. The resulting hydrophobic matrices and immobilized lipases were characterised with regard to specific surface area, adsorption-desorption isotherms, pore volume (V(p)) and size (d(p)) according to nitrogen adsorption and scanning electron microscopy (SEM), physico-chemical properties (thermogravimetric - TG, differential scanning calorimetry - DSC and Fourier transform infrared spectroscopy - FTIR) and the potential for ethyl ester and emulsifier production. The total activity yields (Y(a)) for matrices of immobilized lipase employing protic ionic liquids as additives always resulted in higher values compared with the sample absent the protic ionic liquids, which represents 35-fold increase in recovery of enzymatic activity using the more hydrophobic protic ionic liquids. Compared with arrays of the immobilized biocatalyst without additive, in general, the immobilized biocatalyst in the presence of protic ionic liquids showed increased values of surface area (143-245 m(2) g(-1)) and pore size (19-38 Å). Immobilization with

Photochemical immobilization of anthraquinone conjugated oligonucleotides and PCR amplicons on solid surfaces

DEFF Research Database (Denmark)

Koch, T.; Jacobsen, N.; Fensholdt, J.

2000-01-01

Ligand immobilization on solid surfaces is an essential step in fields such as diagnostics, bio sensor manufacturing, and new material sciences in general. In this paper a photochemical approach based on anthraquinone as the chromophore is presented. Photochemical procedures offer special...... advantages as they are able to generate highly reactive species in an orientation specific manner. As presented here, anthraquinone (AQ) mediated covalent DNA immobilization appears to be superior to currently known procedures. A synthetic procedure providing AQ-phosphoramidites is presented. These reagents...... facilitate AQ conjugation during routine DNA synthesis, thus enabling the AQ-oligonucleotides to be immobilized in a very convenient and efficient manner. AQ-conjugated PCR primers can be used directly in PCR. When the PCR is performed in solution, the amplicons can be immobilized after the PCR. Moreover...

Simultaneously and separately immobilizing incompatible dual-enzymes on polymer substrate via visible light induced graft polymerization

Science.gov (United States)

Zhu, Xing; He, Bin; Zhao, Changwen; Ma, Yuhong; Yang, Wantai

2018-04-01

Developing facile and mild strategy to construct multi-enzymes immobilization system has attracted considerable attentions in recent years. Here a simple immobilization strategy called visible light induced graft polymerization that can simultaneously and separately encapsulate two kinds of enzymes on one polymer film was proposed. Two incompatible enzymes, trypsin and transglutaminase (TGase) were selected as model dual-enzymes system and simultaneously immobilized on two sides of low-density polyethylene (LDPE) film. After immobilization, it was found that more than 90% of the enzymes can be embedded into dual-enzymes loaded film without leakage. And the activities of both separately immobilized enzymes were higher than the activities of mixed co-immobilized enzymes or the sequential immobilized ones. This dual-enzymes loaded film (DEL film) showed excellent recyclability and can retain >87% activities of both enzymes after 4 cycles of utilization. As an example, this DEL film was used to conjugate a prodrug of cytarabine with a target peptide. The successful preparation of expected product demonstrated that the separately immobilized two enzymes can worked well together to catalyze a two-step reaction.

Direct immobilization and hybridization of DNA on group III nitride semiconductors

Energy Technology Data Exchange (ETDEWEB)

Xu Xiaobin; Jindal, Vibhu; Shahedipour-Sandvik, Fatemeh; Bergkvist, Magnus [College of Nanoscale Science and Engineering, University at Albany (SUNY), 255 Fuller Road, Albany, NY 12203 (United States); Cady, Nathaniel C. [College of Nanoscale Science and Engineering, University at Albany (SUNY), 255 Fuller Road, Albany, NY 12203 (United States)], E-mail: ncady@uamail.albany.edu

2009-03-15

A key concern for group III-nitride high electron mobility transistor (HEMT) biosensors is the anchoring of specific capture molecules onto the gate surface. To this end, a direct immobilization strategy was developed to attach single-stranded DNA (ssDNA) to AlGaN surfaces using simple printing techniques without the need for cross-linking agents or complex surface pre-functionalization procedures. Immobilized DNA molecules were stably attached to the AlGaN surfaces and were able to withstand a range of pH and ionic strength conditions. The biological activity of surface-immobilized probe DNA was also retained, as demonstrated by sequence-specific hybridization experiments. Probe hybridization with target ssDNA could be detected by PicoGreen fluorescent dye labeling with a minimum detection limit of 2 nM. These experiments demonstrate a simple and effective immobilization approach for attaching nucleic acids to AlGaN surfaces which can further be used for the development of HEMT-based DNA biosensors.

Immobilization of yeast cells with ionic hydrogel produced by radiation polymerization

International Nuclear Information System (INIS)

Lu Zhaoxin; Fujimura, T.

1990-01-01

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 60 Co 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

Stabilization of penicillin G acylase by immobilization on glutaraldehyde-activated chitosan

Directory of Open Access Journals (Sweden)

W. S. Adriano

2005-12-01

Full Text Available The objective of this work was to study enzyme immobilization on chitosan activated with glutaraldehyde, aiming to produce a cheap biocatalyst. Two different immobilization strategies were studied: one-point and multipoint covalent attachment to the solid matrix. The multipoint covalent attachment derivative had an 82% immobilization yield. It was 4.9-fold more stable than the free enzyme at 50°C and 4.5-fold more stable than soluble enzyme at pH 10.0. The one-point derivative had an 85% immobilization yield. It was 2.7-fold more stable than the free enzyme at 50°C and 3.8-fold more stable than soluble PGA at pH 10.0. Results indicated that chitosan can be loaded with PGA above 330 IU/g. Intraparticle diffusive effects, however, limited hydrolysis of penicillin G catalyzed by those derivatives at 37°C and 25°C. Operational stability assays were performed and the multipoint derivative exhibited a half-life of 40 hours.

New mouse model of skeletal muscle atrophy using spiral wire immobilization.

Science.gov (United States)

Onda, Akiko; Kono, Hajime; Jiao, Qibin; Akimoto, Takayuki; Miyamoto, Toshikazu; Sawada, Yasuhiro; Suzuki, Katsuhiko; Kusakari, Yoichiro; Minamisawa, Susumu; Fukubayashi, Toru

2016-10-01

Disuse-induced skeletal muscle atrophy is a serious concern; however, there is not an effective mouse model to elucidate the molecular mechanisms. We developed a noninvasive atrophy model in mice. After the ankle joints of mice were bandaged into a bilateral plantar flexed position, either bilateral or unilateral hindlimbs were immobilized by wrapping in bonsai steel wire. After 3, 5, or 10 days of immobilization of the hip, knee, and ankle, the weight of the soleus and plantaris muscles decreased significantly in both bilateral and unilateral immobilization. MAFbx/atrogin-1 and MuRF1 mRNA was found to have significantly increased in both muscles, consistent with disuse-induced atrophy. Notably, the procedure did not result in either edema or necrosis in the fixed hindlimbs. This method allows repeated, direct access to the immobilized muscle, making it a useful procedure for concurrent application and assessment of various therapeutic interventions. Muscle Nerve 54: 788-791, 2016. © 2016 Wiley Periodicals, Inc.

Pertechnetate immobilization in aqueous media with hydrogen sulfide under anaerobic and aerobic environments

International Nuclear Information System (INIS)

Liu, Y.; Jurisson, S.; Terry, J.

2007-01-01

The basic chemistry for the immobilization of pertechnetate (TcO 4 - ) by hydrogen sulfide was investigated in aqueous solution under both aerobic and anaerobic environments. Pertechnetate immobilization was acid dependent, with accelerated rates and increased immobilization yields as the acid concentration increased. Oxygen had no effect under acidic conditions. Under anaerobic alkaline conditions, the pH, and therefore the speciation of sulfide, was the determining factor on the immobilization of pertechnetate. Only 53% of the TcO 4 - was immobilized at pH 8, while the yield increased to 83% at pH 9 as HS - became the dominant sulfide species. The immobilization yield then decreased to 73% at pH 13. No reaction was observed between TcO 4 - and sulfide under aerobic alkaline conditions, indicating that oxygen suppressed this reaction. Pertechnetate immobilization was found to be first order with respect to both sulfide and pertechnetate in acidic solutions, and in alkaline solution under anaerobic conditions. The results of stoichiometry studies and product analysis under alkaline anaerobic environments indicated that Tc 2 S 7 was obtained at pH 9. EXAFS (extended X-ray absorption fine structure) and XANES (X-ray absorption near edge structure) studies suggested that the samples obtained from acidic, aerobic solution and alkaline anaerobic solution were both Tc 2 S 7 . The stability of Tc 2 S 7 is affected by O 2 with accelerated dissolution at high pH. (orig.)

A comparison of UV cross-linking and vacuum baking for nucleic acid immobilization and retention

International Nuclear Information System (INIS)

Nierzwicki-Bauer, S.A.; Gebhardt, J.S.; Linkkila, L.; Walsh, K.

1990-01-01

The effectiveness of UV cross-linking and in vacuo baking for the immobilization and retention of DNA to various solid supports was investigated. Optimal immobilization treatments for supported and unsupported nitrocellulose and nylon membranes were: UV cross-linking at 254 nm with an exposure of 120 milliJoules/cm 2 , or baking in vacuo for two hours at 80 degrees C. UV-immobilized nitrocellulose-based membranes showed no increase in sensitivity when compared to baked membranes. An increase in sensitivity was observed for UV-immobilized nylon membranes as compared with baked nylon membranes in some instances, although this varied within lots of the membranes tested. Repeated strippings and heterologous reprobings resulted in loss of target DNA from UV-immobilized nylon membranes as compared to baked nylon membranes. Loss of target DNA from UV-immobilized nitrocellulose-based membranes due to repeated strippings and reprobings was even more pronounced. In vacuo baking of supported and unsupported nitrocellulose and nylon membranes was more effective for immobilization, and more importantly, for retention of target DNA through many reprobings of the same blot

Eggshell membrane: A natural substrate for immobilization and detection of DNA

Energy Technology Data Exchange (ETDEWEB)

Ray, Preetam Guha; Roy, Somenath, E-mail: sroy@cgcri.res.in

2016-02-01

Chemically modified eggshell membranes (ESM) have been explored as potentially novel platforms for immobilization of oligonucleotides and subsequent detection of target DNA. The fibrous network of the native ESM as well those functionalized with acetic acid or n-butyl acetate has been examined by field-emission scanning electron microscopy (FESEM). The formation of surface functional moieties has been confirmed by Fourier-transform infrared spectroscopy (FTIR). DNA molecules, with an end terminal − NH{sub 2} group (at 5′ end) have been immobilized on the chemically modified ESM surface. The effect of surface modification on the DNA immobilization efficiency has been investigated using fluorescence microscopy and atomic force microscopy (AFM). The above studies concurrently suggest that functionalization of ESM with n-butyl acetate causes a better homogeneity of the DNA probes on the membrane surface. On-chip hybridization of the target DNA with the surface bound capture probes has been performed on the functionalized membranes. It is observed that n-butyl acetate modification of ESM pushes the limit of detection (LOD) of the DNA sensors by at least an order of magnitude compared to the other modification method. - Graphical abstract: Eggshell membranes (ESM) have been chemically modified with acetic acid or n-butyl acetate for immobilization of aminated capture probes and subsequent detection of fluorophore-tagged target DNA molecules. n-Butyl acetate modified ESM exhibits superior homogeneity of capture probe immobilization and lower limit of detection for the target DNA molecules. - Highlights: • Eggshell membranes (ESM) have been explored as potentially novel platforms for immobilization of oligonucleotides. • Compared to native ESM, those modified with acetic acid or n-butyl acetate have shown more efficient loading of DNA probes. • ESM modified with n-butyl acetate pushed the lower limit of detection (LOD) of the sensor down to 10 nM of target DNA

Enzyme-immobilized SiO2-Si electrode: Fast interfacial electron transfer with preserved enzymatic activity

Science.gov (United States)

Wang, Gang; Yau, Siu-Tung

2005-12-01

The enzyme, glucose oxidase (GOx), is immobilized using electrostatic interaction on the native oxide of heavily doped n-type silicon. Voltammetric measurement shows that the immobilized GOx gives rise to a very fast enzyme-silicon interfacial electron transfer rate constant of 7.9s-1. The measurement also suggests that the enzyme retains its native conformation when immobilized on the silicon surface. The preserved native conformation of GOx is further confirmed by testing the enzymatic activity of the immobilized GOx using glucose. The GOx-immobilized silicon is shown to behave as a glucose sensor that detects glucose with concentrations as low as 50μM.

Silica Nanofibers with Immobilized Tetracycline for Wound Dressing

Directory of Open Access Journals (Sweden)

Irena Lovětinská-Šlamborová

2016-01-01

Full Text Available Local antibiotic treatment has its justification for superficial infections. The advantage of this treatment is that the antibiotic has effects on bacterial agent directly at the application site. Skin infections which are intended for the local antibiotic treatment are superficial pyoderma, some festering wounds, burns of second and third degree, infected leg ulcers, or decubitus of second and third degree. Tetracyclines are available topical antibiotics with a broad bacterial spectrum. At present, ointments containing tetracycline are also used for the treatment, which rarely can lead to skin sensitization. In this paper, a development of novel nanofibrous material with immobilized tetracycline is presented. Two different methods of immobilized tetracycline quantification onto silica nanofibers are employed. It was proven that the prevailing part of tetracycline was bound weakly by physisorption forces, while the minor part was covalently bound by NH2 groups formed by the preceding functionalization. The silica nanofibers with immobilized tetracycline are promising material for wound dressing applications due to its antibacterial activity; it was proved by tests.

Experimental study on cesium immobilization in struvite structures.

Science.gov (United States)

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

2016-01-25

Ceramicrete, a chemically bonded phosphate ceramic, was developed for nuclear waste immobilization and nuclear radiation shielding. Ceramicrete products are fabricated by an acid-base reaction between magnesium oxide and mono potassium phosphate that has a struvite-K mineral structure. In this study, we demonstrate that this crystalline structure is ideal for incorporating radioactive Cs into a Ceramicrete matrix. This is accomplished by partially replacing K by Cs in the struvite-K structure, thus forming struvite-(K, Cs) mineral. X-ray diffraction and thermo-gravimetric analyses are used to confirm such a replacement. The resulting product is non-leachable and stable at high temperatures, and hence it is an ideal matrix for immobilizing Cs found in high-activity nuclear waste streams. The product can also be used for immobilizing secondary waste streams generated during glass vitrification of spent fuel, or the method described in this article can be used as a pretreatment method during glass vitrification of high level radioactive waste streams. Furthermore, it suggests a method of producing safe commercial radioactive Cs sources. Copyright © 2015 Elsevier B.V. All rights reserved.

Protein-based inverse opals: A novel support for enzyme immobilization.

Science.gov (United States)

Jiang, Yanjun; Sun, Wenya; Wang, Yaping; Wang, Lihui; Zhou, Liya; Gao, Jing; He, Ying; Ma, Li; Zhang, Xu

2017-01-01

In this study, protein-based inverse opals were prepared for the first time by using the colloidal crystal templating method. The preparation process involved three steps including filling the templates with protein molecules, crosslinking, and template removal. The obtained inverse opals were used to immobilize Penicillin G acylase (PGA) because of its intrinsic biocompatible property. The immobilization process was optimized and the properties of the immobilized PGA (PGA@IO) were investigated. PGA@IO exhibited improved thermal and pH stability compared with its free counterpart. After reusing nine times, it retained 70% of the initial activity. Besides, the PGA@IO retained high activity during the hydrolysis reactions in continuous catalysis in packed-bed reactor (PBR) after 15 days. Copyright © 2016 Elsevier Inc. All rights reserved.

DWPF upgrade, immobilization Programmatic Environmental Impact Statement input. Revision 1

International Nuclear Information System (INIS)

Sullivan, I.K.; Bignell, D.

1994-01-01

This Programmatic Environmental Impact Statement (PEIS) addresses the immobilization of plutonium by vitrification. Existing engineering documents, analyses, EIS, and technical publications were used and incorporated wherever possible to provide a timely response to this support effort. Although the vitrification technology is proven for the immobilization of high-level radioactive waste, more study and technical detail will be necessary to provide a comprehensive EIS that fully addresses all aspects of introduction of plutonium to the vitrification process. This document describes the concept(s) of plutonium processing as it relates to the upgrade of the DWPF and is therefore conceptual in nature. These concepts are based on technical data and experience at the Savannah River Site and will be detailed and finalized to support execution of this immobilization option

Immobilization of Aspergillus awamori β-glucosidase on commercial gelatin: An inexpensive and efficient process.

Science.gov (United States)

Nishida, Verônica S; de Oliveira, Roselene F; Brugnari, Tatiane; Correa, Rúbia Carvalho G; Peralta, Rosely A; Castoldi, Rafael; de Souza, Cristina G M; Bracht, Adelar; Peralta, Rosane M

2018-05-01

In this work, a β-glucosidase of Aspergillus awamori with a molecular weight of 180 kDa was produced in solid-state cultures using a mixture of pineapple crown leaves and wheat bran. Maximum production of the enzyme (820 ± 30 U/g substrate) was obtained after 8 days of culture at 28 °C and initial moisture of 80%. The crude enzyme was efficiently immobilized on glutaraldehyde cross-linked commercial gelatin. Immobilization changed the kinetics of the enzyme, whose behavior could no longer be described by a saturation function of the Michaelis-Menten type. Comparative evaluation of the free and immobilized enzyme showed that the immobilized enzyme was more thermostable and less inhibited by glucose than the free form. In consequence of these properties, the immobilized enzyme was able to hydrolyze cellobiose more extensively. In association with Trichoderma reesei cellulase, the free and immobilized β-glucosidase increased the liberation of glucose from cellulose 3- and 5-fold, respectively. Immobilization of the A. awamori β-glucosidase on glutaraldehyde cross-linked commercial gelatin is an efficient and cheap method allowing the reuse of the enzyme by at least 10 times. Copyright © 2018 Elsevier B.V. All rights reserved.

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

Energy Technology Data Exchange (ETDEWEB)

Kang, Jeonghwa [Nano Medical Engineering Laboratory, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako, Saitama, 351-0198 (Japan); Department of Biological Sciences, Tokyo Metropolitan University, 1-1 Minami-Osawa, Tokyo, 192-0397 Japan (Japan); Sakuragi, Makoto; Shibata, Aya; Abe, Hiroshi; Kitajima, Takashi; Tada, Seiichi [Nano Medical Engineering Laboratory, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako, Saitama, 351-0198 (Japan); Mizutani, Masayoshi; Ohmori, Hitoshi [Material Fabrication Laboratory, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako, Saitama, 351-0198 (Japan); Ayame, Hirohito [Diagnostic Biochip Laboratory, RIKEN Center for Intellectual Property Strategies, 2-1 Hirosawa, Wako, Saitama, 351-0198 (Japan); Son, Tae Il [Bioscience and Biotechnology, Chung-Ang University, 40-1 San, Nae-Ri, Daeduck-myun, Ansung-si, Kyungki-do, 456-756 (Korea, Republic of); Aigaki, Toshiro [Department of Biological Sciences, Tokyo Metropolitan University, 1-1 Minami-Osawa, Tokyo, 192-0397 Japan (Japan); Ito, Yoshihiro, E-mail: y-ito@riken.jp [Nano Medical Engineering Laboratory, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako, Saitama, 351-0198 (Japan); Department of Biological Sciences, Tokyo Metropolitan University, 1-1 Minami-Osawa, Tokyo, 192-0397 Japan (Japan); Diagnostic Biochip Laboratory, RIKEN Center for Intellectual Property Strategies, 2-1 Hirosawa, Wako, Saitama, 351-0198 (Japan)

2012-12-01

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: Black-Right-Pointing-Pointer Epidermal growth factor was covalently immobilized on titan or stainless steel surfaces. Black-Right-Pointing-Pointer Amino groups were formed on the surfaces by the treatment and the growth factor was immobilized through amide bonds. Black-Right-Pointing-Pointer The immobilized epidermal growth factor accelerated cell proliferation more than soluble ones on the surfaces.

Computer-aided design of bromelain and papain covalent immobilization

OpenAIRE

Bessy Cutiño-Avila; Dayrom Gil Pradas; Carlos Aragón Abreu; Yuniel Fernández Marrero; Martha Hernández de la Torre; Emir Salas Sarduy; María de los Ángeles Chávez Planes; José Manuel Guisán Seijas; Joaquín Díaz Brito; Alberto del Monte-Martínez

2014-01-01

Título en español: Diseño asistido por computadora de la inmovilización covalente de bromelina y papaína. Título corto: Computer-aided design of bromelain and papain.  Abstract: Enzymes as immobilized derivatives have been widely used in Food, Agrochemical, Pharmaceutical and Biotechnological industries. Protein immobilization is probably the most used technology to improve the operational stability of these molecules. Bromelain (Ananas comosus) and papain (Carica papaya) are cystein pr...

Uranium speciation and stability after reductive immobilization in sediments.

OpenAIRE

Sharp J.O

2011-01-01

It has generally been assumed that the bioreduction of hexavalent uranium in groundwater systems will result in the precipitation of immobile uraninite (UO2). In order to explore the form and stability of uranium immobilized under these conditions we introduced lactate (15 mM for 3 months) into flow through columns containing sediments derived from a former uranium processing site at Old Rifle CO. This resulted in metal reducing conditions as evidenced by concurrent uranium uptake and iron re...

Uranium speciation and stability after reductive immobilization in sediments

OpenAIRE

Sharp, Jonathan O.; Schofield, Eleanor J.; Lezama-Pacheco, Juan S.; Webb, Sam; Ulrich, Kai-Uwe; Blue, Lisa; Chinni, Satyavani; Veeramani, Harish; Junier, Pilar; Margot-Roquier, Camille; Suvorova Buffat, Elena; Tebo, Bradley M.; Giammar, Daniel E.; Bargar, John R.; Bernier-Latmani, Rizlan

2011-01-01

It has generally been assumed that the bioreduction of hexavalent uranium in groundwater systems will result in the precipitation of immobile uraninite (UO2). In order to explore the form and stability of uranium immobilized under these conditions, we introduced lactate (15 mM for 3 months) into flow-through columns containing sediments derived from a former uranium-processing site at Old Rifle, CO. This resulted in metal-reducing conditions as evidenced by concurrent uranium uptake and iron ...

Immobilization of Recombinant Glucose Isomerase for Efficient Production of High Fructose Corn Syrup.

Science.gov (United States)

Jin, Li-Qun; Xu, Qi; Liu, Zhi-Qiang; Jia, Dong-Xu; Liao, Cheng-Jun; Chen, De-Shui; Zheng, Yu-Guo

2017-09-01

Glucose isomerase is the important enzyme for the production of high fructose corn syrup (HFCS). One-step production of HFCS containing more than 55% fructose (HFCS-55) is receiving much attention for its industrial applications. In this work, the Escherichia coli harboring glucose isomerase mutant TEGI-W139F/V186T was immobilized for efficient production of HFCS-55. The immobilization conditions were optimized, and the maximum enzyme activity recovery of 92% was obtained. The immobilized glucose isomerase showed higher pH, temperature, and operational stabilities with a K m value of 272 mM and maximum reaction rate of 23.8 mM min -1 . The fructose concentration still retained above 55% after the immobilized glucose isomerase was reused for 10 cycles, and more than 85% of its initial activity was reserved even after 15 recycles of usage at temperature of 90 °C. The results highlighted the immobilized glucose isomerase as a potential biocatalyst for HFCS-55 production.

Spectroscopic properties of triangular silver nanoplates immobilized on polyelectrolyte multilayer-modified glass substrates

Science.gov (United States)

Rabor, Janice B.; Kawamura, Koki; Muko, Daiki; Kurawaki, Junichi; Niidome, Yasuro

2017-07-01

Fabrication of surface-immobilized silver nanostructures with reproducible plasmonic properties by dip-coating technique is difficult due to shape alteration. To address this challenge, we used a polyelectrolyte multilayer to promote immobilization of as-received triangular silver nanoplates (TSNP) on a glass substrate through electrostatic interaction. The substrate-immobilized TSNP were characterized by absorption spectrophotometry and scanning electron microscopy. The bandwidth and peak position of localized surface plasmon resonance (LSPR) bands can be tuned by simply varying the concentration of the colloidal solution and immersion time. TSNP immobilized from a higher concentration of colloidal solution with longer immersion time produced broadened LSPR bands in the near-IR region, while a lower concentration with shorter immersion time produced narrower bands in the visible region. The shape of the nanoplates was retained even at long immersion time. Analysis of peak positions and bandwidths also revealed the point at which the main species of the immobilization had been changed from isolates to aggregates.

Purification, immobilization, and characterization of nattokinase on PHB nanoparticles.

Science.gov (United States)

Deepak, Venkataraman; Pandian, Suresh babu Ram Kumar; Kalishwaralal, Kalimuthu; Gurunathan, Sangiliyandi

2009-12-01

In this study, nattokinase was purified from Bacillus subtilis using ion exchange chromatography and immobilized upon polyhydroxybutyrate (PHB) nanoparticles. A novel strain isolated from industrial dairy waste was found to synthesize polyhydroxyalkanoates (PHA) and the strain was identified as Brevibacterium casei SRKP2. PHA granules were extracted from 48 h culture and the FT-IR analysis characterized them as PHB, a natural biopolymer from B. casei. Nanoprecipitation by solvent displacement technique was used to synthesize PHB nanoparticles. PHB nanoparticles were characterized using transmission electron microscopy and particle size ranged from 100-125 nm. Immobilization of nattokinase upon PHB nanoparticles resulted in a 20% increase in the enzyme activity. Immobilization also contributed to the enhanced stability of the enzyme. Moreover, the activity was completely retained on storage at 4 degrees C for 25 days. The method has proven to be highly simple and can be implemented to other enzymes also.

Physical immobilization of 60 kDa chaperonin linked lipase from pseudomonas aeruginosa BN-1

International Nuclear Information System (INIS)

Syed, M.N.; Mehmood, S.; Bashir, A.; Ashraf, F.

2012-01-01

Abstract: The 60 kDa chaperone linked lipase from Pseudomonas aeruginosa was subjected to physical adsorption on silica 60 and acrylic beads. It was found that higher enzyme loading was achieved on silica gel than acrylic bead. The half life of immobilized enzyme was greater compared to the free enzyme. The adsorption of the enzyme onto a solid phase also resulted in increased thermo and solvent stability. It was observed that soluble enzyme showed maximum stability at 70 degree C while immobilized enzyme showed stability up to 80 degree C for 45 minutes. The stability of immobilized enzyme increased up to 48 hours from 24 hours against different organic solvent at 1.0 M concentration. It was noted that enzyme immobilized on acrylic beads have greater reusability compared to silica immobilized enzyme. (author)

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.

Co immobilization by two manganese oxidizing isolates from Carlsberg Ridge waters (CR35 and CR48) was compared with that of Mn at same molar concentrations. At a lower concentration of 10 mu M, CR35 and CR48 immobilized 22 and 23 fM Co cell-1...

Sol-gel immobilization of serine proteases for application in organic solvents

NARCIS (Netherlands)

van Unen, D.J.; Engbersen, Johannes F.J.; Reinhoudt, David

2001-01-01

The serine proteases α-chymotrypsin, trypsin, and subtilisin Carlsberg were immobilized in a sol-gel matrix and the effects on the enzyme activity in organic media are evaluated. The percentage of immobilized enzyme is 90% in the case of α-chymotrypsin and the resulting specific enzyme activity in

Synthesis of structured phospholipids by immobilized phospholipase A2 catalyzed acidolysis

DEFF Research Database (Denmark)

Vikbjerg, Anders Falk; Vikbjerg, Anders Falk; Xu, Xuebing

2007-01-01

Acyl modification of the sn-2 position in phospholipids (PLs) was conducted by acidolysis reaction using immobilized phospholipase A2 (PLA2) as the catalyst. In the first stage we screened different carriers for their ability to immobilize PLA2. Several carriers were able to fix the enzyme...

Approaching Immobilization of Enzymes onto Open Porous Basotect®

Directory of Open Access Journals (Sweden)

Peter J. Allertz

2017-11-01

Full Text Available For the first time, commercial macroporous melamine formaldehyde foam Basotect® (BT was used as a basic carrier material for both adsorptive and covalent enzyme immobilization. In order to access inherent amino groups, the Basotect® surface was pretreated with hydrochloric acid. The resulting material revealed 6 nmol of superficial amino groups per milligram Basotect®. Different optimized strategies for tethering the laccase from Trametes versicolor and the lipase from Thermomyces lanuginosus onto the pre-treated Basotect® surface were studied. Particularly, for covalent immobilization, two different strategies were pursued: lipase was tethered via a cross-linking method using 1-ethyl-3-(3-dimethylaminopropylcarbodiimide, and laccase was bound after functionalizing Basotect® with hydrophilic copolymer poly(ethylene-alt-maleic anhydride (PEMA. Prior to laccase immobilization, the PEMA coating of Basotect® was verified by ATR-FTIR analysis. Subsequent quantification of available high-reactive PEMA anhydride moieties revealed an amount of 1028 ± 73 nmol per mg Basotect®. The surface-bound enzyme amounts were quantified as 4.1–5.8 μg per mg Basotect®. A theoretical surface-covered enzyme mass for the ideal case that an enzyme monolayer was immobilized onto the Basotect® surface was calculated and compared to the amount of adsorptive and covalently bound enzymes before and after treatment with SDS. Furthermore, the enzyme activities were determined for the different immobilization approaches, and the stability during storage over time and against sodium dodecyl sulfate treatment was monitored. Additionally, PEMA-BT-bound laccase was tested for the elimination of anthropogenic micropollutant bisphenol A from contaminated water in a cost-effective and environmentally-friendly way and resulted in a degradation rate higher than 80%.

Polyacrolein/mesoporous silica nanocomposite: Synthesis, thermal stability and covalent lipase immobilization

Energy Technology Data Exchange (ETDEWEB)

Motevalizadeh, Seyed Farshad; Khoobi, Mehdi; Shabanian, Meisam [Department of Medicinal Chemistry, Faculty of Pharmacy and Pharmaceutical Sciences Research Center, Tehran University of Medical Sciences, Tehran 14176 (Iran, Islamic Republic of); Asadgol, Zahra; Faramarzi, Mohammad Ali [Department of Pharmaceutical Biotechnology, Faculty of Pharmacy and Biotechnology Research Center, Tehran University of Medical Sciences, P.O. Box 14155-6451, Tehran 14176 (Iran, Islamic Republic of); Shafiee, Abbas, E-mail: ashafiee@ams.ac.ir [Department of Medicinal Chemistry, Faculty of Pharmacy and Pharmaceutical Sciences Research Center, Tehran University of Medical Sciences, Tehran 14176 (Iran, Islamic Republic of); Center of Excellence in Biothermodynamics, University of Tehran, Tehran (Iran, Islamic Republic of)

2013-12-16

In this work, new polyacrolein/MCM-41 nanocomposites with good phase mixing behavior were prepared through an emulsion polymerization technique. Mesoporous silica was synthesized by in situ assembly of tetraethyl orthosilicate (TEOS) and cetyl trimethyl ammonium bromide (CTAB). The structure and properties of polyacrolein containing nanosized MCM-41 particle (5 and 10 wt%), were investigated by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction, Dynamic light scattering (DLS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N{sub 2} adsorption techniques, and thermogravimetric (TGA) analyses. The SEM images from the final powder have revealed good dispersion of the MCM-41 nanoparticles throughout polymeric matrix with no distinct voids between two phases. The results indicated that the thermal properties of the nanocomposite were enhanced by addition of MCM-41. Thermomyces lanuginosa lipase (TLL) was used as a model biocatalyst and successfully immobilized with polyacrolein and the nanocomposite via covalent bonds with the aldehyde groups. The activity between free enzyme, polyacrolein, and MCM-41 nanocomposite (10 wt%)-immobilized TLL was compared. The immobilized lipase with the nanocomposite shows better operational stability such as pH tolerance, thermal and storage stability. In addition, the immobilized lipase with the nanocomposite can be easily recovered and retained at 74% of its initial activity after 15 time reuses. - Graphical abstract: The influence of incorporation of mesoporous MCM-41 nanoparticle with polyacrolein on the thermal properties and enzyme immobilization was investigated. - Highlights: • Polyacrolein/MCM-41 nanocomposites were prepared by emulsion polymerization method. • Thermal stability and char residues in nanocomposites were improved. • Nanocomposites significant effects on immobilization of lipase.

Stable functionalization of germanium surface and its application in biomolecules immobilization

Energy Technology Data Exchange (ETDEWEB)

Cai, Qi [State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, No.865, Changning Road, Shanghai 200050 (China); University of Chinese Academy of Sciences, No.19A, Yuquan Road, Beijing 100049 (China); Xu, Baojian [State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, No.865, Changning Road, Shanghai 200050 (China); Ye, Lin [Sate Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, No.865, Changning Road, Shanghai 200050 (China); University of Chinese Academy of Sciences, No.19A, Yuquan Road, Beijing 100049 (China); Tang, Teng; Huang, Shanluo; Du, Xiaowei [State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, No.865, Changning Road, Shanghai 200050 (China); University of Chinese Academy of Sciences, No.19A, Yuquan Road, Beijing 100049 (China); Bian, Xiaojun; Zhang, Jishen [State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, No.865, Changning Road, Shanghai 200050 (China); Di, Zengfeng, E-mail: zfdi@mail.sim.ac.cn [Sate Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, No.865, Changning Road, Shanghai 200050 (China); Jin, Qinghui [State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, No.865, Changning Road, Shanghai 200050 (China); Zhao, Jianlong, E-mail: jlzhao@mail.sim.ac.cn [State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, No.865, Changning Road, Shanghai 200050 (China)

2014-10-15

Highlights: • An effective method to immobilize biomolecules on the functionalized Ge surface. • The surface of Ge was functionalized with 11-Mercaptoundecanoic acid (11-MUA). • Stable and uniform SAMs was obtained on Ge surface after 11-MUA treatment. • The functionalized Ge was employed as substrate for protein immobilization. • Paving the way of Ge for further applications in bioelectronics field. - Abstract: As a typical semiconductor material, germanium (Ge) has the potential to be utilized in microelectronics and bioelectronics. Herein, we present a simple and effective method to immobilize biomolecules on the surface of functionalized Ge. The surface oxide of Ge was removed with the pretreatment of hydrochloric acid and the Cl-terminated Ge reacted with 11-Mercaptoundecanoic acid (11-MUA). The surface of Ge was coated with 11-MUA self-assembled monolayers (SAMs) due to the bonding reaction between the sulfhydryl group of 11-MUA and Cl-terminated Ge. Furthermore, typical biomolecule, a green fluorescent protein was chosen to be immobilized on the surface of the functionalized Ge. Contact angle analysis, atomic force microscopy and X-ray photoelectron spectroscopy were used to study the characteristics including wettability, stability, roughness and component of the functionalized Ge, respectively. Fluorescence microscopy was utilized to indicate the efficiency of protein immobilization on the surface of the functionalized Ge. With these studies, stable and uniform functionalized monolayer was obtained on the surface of Ge after 11-MUA treatment and the functionalized Ge was effectively applied in protein immobilization. Furthermore, this study may pave the way for further applications such as the integration of bioelectronics and biosensors with the attractive semiconductor material-Ge in future work.

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.

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

KAUST Repository

Wagner, Rachel C; Porter-Gill, Sikandar; Logan, Bruce E

2012-01-01

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.

Rapid detection of food pathogens using RNA aptamers-immobilized slide.

Science.gov (United States)

Maeng, Jin-Soo; Kim, Namsoo; Kim, Chong-Tai; Han, Seung Ryul; Lee, Young Ju; Lee, Seong-Wook; Lee, Myung-Hyun; Cho, Yong-Jin

2012-07-01

The purpose of this study was to develop a simple and rapid detection system for foodborne bacteria, which consisted of an optical microscope and its slide chip with artificial antibodies, or RNA aptamers. From an RNA pool, three each RNA aptamers were built by the method of SELEX (systematic evolution of ligands by exponential enrichment) for components of cell wall, LPS (lipopolysaccharide) from E. coli O157:H7, teichoic acid from Staphylococcus aureus and a cell membrane protein of OmpC from Salmonella typhimurium, respectively. These aptamers were hybridized with thiol-conjugated 16 dT-linker molecules in order to be immobilized on silver surface which was, in advance, fabricated on glass slide, using a spin-coating method. To confirm that each aptamers retained its specific binding activities to their antigenic live bacteria, microscopic view of bound cells immobilized on silver film were observed. Furthermore, we observed the fluorescence-emitting bacteria-aptamer complex immobilized on silver film after adding RNA aptamers hybridized with fluorophore, FAM-conjugated 16 dT-linker molecules. As a result, the RNA aptamers-immobilized slide system developed in this study was a useful new tool to rapidly monitor individual food pathogens.

Evaluation of cellulose-binding domain fused to a lipase for the lipase immobilization.

Science.gov (United States)

Hwang, Sangpill; Ahn, Jungoh; Lee, Sumin; Lee, Tai Gyu; Haam, Seungjoo; Lee, Kangtaek; Ahn, Ik-Sung; Jung, Joon-Ki

2004-04-01

A cellulose-binding domain (CBD) fragment of a cellulase gene of Trichoderma hazianum was fused to a lipase gene of Bacillus stearothermophilus L1 to make a gene cluster for CBD-BSL lipase. The specific activity of CBD-BSL lipase for oil hydrolysis increased by 33% after being immobilized on Avicel (microcrystalline cellulose), whereas those of CBD-BSL lipase and BSL lipase decreased by 16% and 54%, respectively, after being immobilized on silica gel. Although the loss of activity of an enzyme immobilized by adsorption has been reported previously, the loss of activity of the CBD-BSL lipase immobilized on Avicel was less than 3% after 12 h due to the irreversible binding of CBD to Avicel.

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

International Nuclear Information System (INIS)

Kumakura, M.; Kaetsu, I.

1983-01-01

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

Experimental joint immobilization in guinea pigs. Effects on the knee joint

Science.gov (United States)

Marcondesdesouza, J. P.; Machado, F. F.; Sesso, A.; Valeri, V.

1980-01-01

In young and adult guinea pigs, the aftermath experimentally induced by the immobilization of the knee joint in hyperextended forced position was studied. Joint immobilization which varied from one to nine weeks was attained by plaster. Eighty knee joints were examined macro and microscopically. Findings included: (1) muscular hypotrophy and joint stiffness in all animals, directly proportional to the length of immobilization; (2) haemoarthrosis in the first week; (3) intra-articular fibrous tissue proliferation ending up with fibrous ankylosis; (4) hyaline articular cartilage erosions; (5) various degrees of destructive menisci changes. A tentative explanation of the fibrous tissue proliferation and of the cartilage changes is offered.

Supplemental Immobilization of Hanford Low-Activity Waste: Cast Stone Screening Tests

Energy Technology Data Exchange (ETDEWEB)

Westsik, Joseph H. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Piepel, Gregory F. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lindberg, Michael J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Heasler, Patrick G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Mercier, Theresa M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Russell, Renee L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Cozzi, Alex [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Daniel, William E. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Eibling, Russell E. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Hansen, E. K. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Reigel, Marissa M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Swanberg, David J. [Washington River Protection Solutions (WRPS), Aiken, SC (United States)

2013-09-30

More than 56 million gallons of radioactive and hazardous waste are stored in 177 underground storage tanks at the U.S. Department of Energy’s (DOE’s) Hanford Site in southeastern Washington State. The Hanford Tank Waste Treatment and Immobilization Plant (WTP) is being constructed to treat the wastes and immobilize them in a glass waste form. The WTP includes a pretreatment facility to separate the wastes into a small volume of high-level waste (HLW) containing most of the radioactivity and a larger volume of low-activity waste (LAW) containing most of the nonradioactive chemicals. The HLW will be converted to glass in the HLW vitrification facility for ultimate disposal at an offsite federal repository. At least a portion (~35%) of the LAW will be converted to glass in the LAW vitrification facility and will be disposed of onsite at the Integrated Disposal Facility (IDF). The pretreatment and HLW vitrification facilities will have the capacity to treat and immobilize the wastes destined for each facility. However, a second LAW immobilization facility will be needed for the expected volume of LAW requiring immobilization. A cementitious waste form known as Cast Stone is being considered to provide the required additional LAW immobilization capacity. The Cast Stone waste form must be acceptable for disposal in the IDF. The Cast Stone waste form and immobilization process must be tested to demonstrate that the final Cast Stone waste form can comply with the waste acceptance criteria for the disposal facility and that the immobilization processes can be controlled to consistently provide an acceptable waste form product. Further, the waste form must be tested to provide the technical basis for understanding the long-term performance of the waste form in the disposal environment. These waste form performance data are needed to support risk assessment and performance assessment (PA) analyses of the long-term environmental impact of the waste disposal in the IDF

Cyclooxygenase-2 inhibitor celecoxib attenuates joint contracture following immobilization in rat knees.

Science.gov (United States)

Ozawa, Junya; Kaneguchi, Akinori; Tanaka, Ryo; Kito, Nobuhiro; Moriyama, Hideki

2016-10-24

The aim of this study is to clarify the following two points: First, whether a cyclooxygenase-2 mediated pathway is involved in the formation of immobilization-induced joint contracture and, second, the effectiveness of oral administration of non-steroidal anti-inflammatory drug celecoxib (CBX) for the prevention of myogenic and arthrogenic contracture following immobilization in a rat model. Thirty male rats were randomly divided into three groups: immobilization (Im), Im + CBX, and control (n = 10 each). External fixation immobilized the right knee joint of Im and Im + CBX groups in flexion for 3 weeks. 50 mg/kg of CBX was administrated daily to the Im + CBX group during this period. The passive range of motion (ROM) of knee joints was measured before and after transection of knee flexor muscles and myogenic and arthrogenic ROM restrictions were calculated. The semitendinosus muscles and knee joints were investigated histologically to elucidate factors responsible for contracture. Myogenic ROM restrictions were exhibited both in Im and Im + CBX groups (44 ± 5 and 36 ± 8 °, respectively), but restrictions significantly decreased in the Im + CBX group compared to the Im group. Significant reductions of the muscle length ratios (Rt/Lt) and sarcomere number ratios (Rt/Lt) in knee flexor semitendinosus muscle, which are responsible for myogenic contracture, were also seen both in Im group (92 ± 5 and 92 ± 4 %, respectively) and Im + CBX group (97 ± 3 and 97 ± 3 %, respectively), but were inhibited by CBX administration (P muscle shortening following immobilization. These results imply that inflammation and nociception are involved in myogenic contracture formation independently of joint immobilization, and that CBX is effective in preventing joint contracture following immobilization in rats.

Optimization of Phospholipase A1 Immobilization on Plasma Surface Modified Chitosan Nanofibrous Mat

Directory of Open Access Journals (Sweden)

Zahra Beig Mohammadi

2016-01-01

Full Text Available Phospholipase A1 is known as an effective catalyst for hydrolysis of various phospholipids in enzymatic vegetable oil degumming. Immobilization is one of the most efficient strategies to improve its activity, recovery and functional properties. In this study, chitosan-co-polyethylene oxide (90:10 nanofibrous mat was successfully fabricated and modified with atmospheric plasma at different times (2, 6 and 10 min to interact with enzyme molecules. Scanning electron microscopy images revealed that the membranes retained uniform nanofibrous and open porous structures before and after the treatment. PLA1 was successfully immobilized onto the membrane surfaces via covalent bonds with the functional groups of chitosan nanofibrous mat. Response surface methodology was used to optimize the immobilization conditions for reaching the maximum immobilization efficiency. Enzyme concentration, pH, and immobilization time were found to be significant key factors. Under optimum conditions (5.03 h, pH 5.63, and enzyme dosage 654.36 UI, the atmospheric plasma surface modified chitosan nanofibers reached the highest immobilization efficiency (78.50%. Fourier transform infrared spectroscopy of the control and plasma surface-modified chitosan nanofibers revealed the functional groups of nanofibers and their reaction with the enzyme. The results indicated that surface modification by atmospheric plasma induced an increase in PLA1 loading on the membrane surfaces.

Lipases Immobilization for Effective Synthesis of Biodiesel Starting from Coffee Waste Oils

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Lucia Gardossi

2013-08-01

Full Text Available Immobilized lipases were applied to the enzymatic conversion of oils from spent coffee ground into biodiesel. Two lipases were selected for the study because of their conformational behavior analysed by Molecular Dynamics (MD simulations taking into account that immobilization conditions affect conformational behavior of the lipases and ultimately, their efficiency upon immobilization. The enzymatic synthesis of biodiesel was initially carried out on a model substrate (triolein in order to select the most promising immobilized biocatalysts. The results indicate that oils can be converted quantitatively within hours. The role of the nature of the immobilization support emerged as a key factor affecting reaction rate, most probably because of partition and mass transfer barriers occurring with hydrophilic solid supports. Finally, oil from spent coffee ground was transformed into biodiesel with yields ranging from 55% to 72%. The synthesis is of particular interest in the perspective of developing sustainable processes for the production of bio-fuels from food wastes and renewable materials. The enzymatic synthesis of biodiesel is carried out under mild conditions, with stoichiometric amounts of substrates (oil and methanol and the removal of free fatty acids is not required.