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Sample records for medium-chain-length polyhydroxyalkanoate granule

  1. Synthesis Gas (Syngas)-Derived Medium-Chain-Length Polyhydroxyalkanoate Synthesis in Engineered Rhodospirillum rubrum.

    Science.gov (United States)

    Heinrich, Daniel; Raberg, Matthias; Fricke, Philipp; Kenny, Shane T; Morales-Gamez, Laura; Babu, Ramesh P; O'Connor, Kevin E; Steinbüchel, Alexander

    2016-10-15

    The purple nonsulfur alphaproteobacterium Rhodospirillum rubrum S1 was genetically engineered to synthesize a heteropolymer of mainly 3-hydroxydecanoic acid and 3-hydroxyoctanoic acid [P(3HD-co-3HO)] from CO- and CO 2 -containing artificial synthesis gas (syngas). For this, genes from Pseudomonas putida KT2440 coding for a 3-hydroxyacyl acyl carrier protein (ACP) thioesterase (phaG), a medium-chain-length (MCL) fatty acid coenzyme A (CoA) ligase (PP_0763), and an MCL polyhydroxyalkanoate (PHA) synthase (phaC1) were cloned and expressed under the control of the CO-inducible promoter P cooF from R. rubrum S1 in a PHA-negative mutant of R. rubrum P(3HD-co-3HO) was accumulated to up to 7.1% (wt/wt) of the cell dry weight by a recombinant mutant strain utilizing exclusively the provided gaseous feedstock syngas. In addition to an increased synthesis of these medium-chain-length PHAs (PHA MCL ), enhanced gene expression through the P cooF promoter also led to an increased molar fraction of 3HO in the synthesized copolymer compared with the P lac promoter, which regulated expression on the original vector. The recombinant strains were able to partially degrade the polymer, and the deletion of phaZ2, which codes for a PHA depolymerase most likely involved in intracellular PHA degradation, did not reduce mobilization of the accumulated polymer significantly. However, an amino acid exchange in the active site of PhaZ2 led to a slight increase in PHA MCL accumulation. The accumulated polymer was isolated; it exhibited a molecular mass of 124.3 kDa and a melting point of 49.6°C. With the metabolically engineered strains presented in this proof-of-principle study, we demonstrated the synthesis of elastomeric second-generation biopolymers from renewable feedstocks not competing with human nutrition. Polyhydroxyalkanoates (PHAs) are natural biodegradable polymers (biopolymers) showing properties similar to those of commonly produced petroleum-based nondegradable polymers. The

  2. Second-generation functionalized medium-chain-length polyhydroxyalkanoates: the gateway to high-value bioplastic applications.

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    Tortajada, Marta; da Silva, Luiziana Ferreira; Prieto, María Auxiliadora

    2013-03-01

    Polyhydroxyalkanoates (PHAs) are biodegradable biocompatible polyesters, which accumulate as granules in the cytoplasm of many bacteria under unbalanced growth conditions. Medium-chain-length PHAs (mcl-PHAs), characterized by C6-C14 branched monomer chains and typically produced by Pseudomonas species, are promising thermoelastomers, as they can be further modified by introducing functional groups in the side chains. Functionalized PHAs are obtained either by feeding structurally related substrates processed through the beta-oxidation pathway, or using specific strains able to transform sugars or glycerol into unsaturated PHA by de novo fatty-acid biosynthesis. Functionalized mcl-PHAs provide modified mechanical and thermal properties, and consequently have new processing requirements and highly diverse potential applications in emergent fields such as biomedicine. However, process development and sample availability are limited due to the toxicity of some precursors and still low productivity, which hinder investigation. Conversely, improved mutant strains designed through systems biology approaches and cofeeding with low-cost substrates may contribute to the widespread application of these biopolymers. This review focuses on recent developments in the production of functionalized mcl-PHAs, placing particular emphasis on strain and bioprocess design for cost-effective production.

  3. Enhancement of medium-chain-length polyhydroxyalkanoates biosynthesis from glucose by metabolic engineering in Pseudomonas mendocina.

    Science.gov (United States)

    Wang, Yuanyuan; Zhao, Fengjie; Fan, Xu; Wang, Shufang; Song, Cunjiang

    2016-02-01

    To enhance the biosynthesis of medium-chain-length polyhydroxyalkanoates (PHAMCL) from glucose in Pseudomonas mendocina NK-01, metabolic engineering strategies were used to block or enhance related pathways. Pseudomonas mendocina NK-01 produces PHAMCL from glucose. Besides the alginate oligosaccharide biosynthetic pathway proved by our previous study, UDP-D-glucose and dTDP-L-rhamnose biosynthetic pathways were identified. These might compete for glucose with the PHAMCL biosynthesis. First, the alg operon, galU and rmlC gene were deleted one by one, resulting in NK-U-1(∆alg), NK-U-2 (∆alg∆galU), NK-U-3(alg∆galU∆rmlC). After fermentation for 36 h, the cell dry weight (CDW) and PHAMCL production of these strains were determined. Compared with NK-U: 1) NK-U-1 produced elevated CDW (from 3.19 ± 0.16 to 3.5 ± 0.11 g/l) and equal PHAMCL (from 0.78 ± 0.06 to 0.79 ± 0.07 g/l); 2) NK-U-2 produced more CDW (from 3.19 ± 0.16 to 3.55 ± 0.23 g/l) and PHAMCL (from 0.78 ± 0.06 to 1.05 ± 0.07 g/l); 3) CDW and PHAMCL dramatically decreased in NK-U-3 (1.53 ± 0.21 and 0.41 ± 0.09 g/l, respectively). Additionally, the phaG gene was overexpressed in strain NK-U-2. Although CDW of NK-U-2/phaG decreased to 1.29 ± 0.2 g/l, PHA titer (%CDW) significantly increased from 24.5 % up to 51.2 %. The PHAMCL biosynthetic pathway was enhanced by blocking branched metabolic pathways in combination with overexpressing phaG gene.

  4. Production of Medium Chain Length Polyhydroxyalkanoates From Oleic Acid Using Pseudomonas putida PGA1 by Fed Batch Culture

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    Sidik Marsudi

    2010-10-01

    Full Text Available Bacterial polyhydroxyalkanoates (PHAs are a class of p0lymers currently receiving much attention because of their potential as renewable and biodegradable plastics. A wide variety of bacteria has been reported to produce PHAs including Pseudomonas strains. These strains are known as versatile medium chain length PHAs (PHAs-mcl producers using fatty acids as carbon source. Oleic acid was used to produce PHAs-mcl using Pseudomonas putida PGA 1 by continuous feeding of both nitrogen and carbon source, in a fed batch culture. During cell growth, PHAs also accumulated, indicating that PHA production in this organism is growth associated. Residual cell increased until the nitrogen source was depleted. At the end of fermentation, final cell concentration, PHA content, and roductivity were 30.2 g/L, 44.8 % of cell dry weight, and 0.188 g/l/h, respectively.

  5. Synthesis of Medium-Chain-Length Polyhydroxyalkanoate Homopolymers, Random Copolymers, and Block Copolymers by an Engineered Strain of Pseudomonas entomophila.

    Science.gov (United States)

    Wang, Ying; Chung, Ahleum; Chen, Guo-Qiang

    2017-04-01

    Medium-chain-length polyhydroxyalkanoates (mcl-PHAs), widely used in medical area, are commonly synthesized by Pseudomonas spp. This study tries to use β-oxidation pathways engineered P. entomophila to achieve single source of a series of mcl-monomers for microbial production of PHA homopolymers. The effort is proven successful for the first time to obtain a wide range of mcl-PHA homopolymers from engineered P. entomophila LAC23 grown on various fatty acids, respectively, ranging from poly(3-hydroxyheptanoate) to poly(3-hydroxytetradecanoate). Effects of a PHA monomer chain length on thermal and crystallization properties including the changes of T m , T g , and T d5% are investigated. Additionally, strain LAC23 is used to synthesize random copolymers of 3-hydroxyoctanoate (3HO) and 3-hydroxydodecanoate (3HDD) or 3-hydroxytetradecanoates, their compositions could be controlled by adjusting the ratios of two related fatty acids. Meanwhile, block copolymer P(3HO)-b-P(3HDD) is synthesized by the same strain. It is found for the first time that even- and odd number mcl-PHA homopolymers have different physical properties. When the gene of the PHA synthase in the engineered P. entomophila is replaced by phaC from Aeromonas hydrophila 4AK4, poly(3-hydroxybutyrate-co-30 mol%-3-hydroxyhexanoate) is synthesized. Therefore, P. entomophila can be used to synthesize the whole range of PHA (C7-C14) homopolymers, random- and block copolymers. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Increasing the Carbon Flux toward Synthesis of Short-Chain-Length-Medium-Chain-Length Polyhydroxyalkanoate in the Peroxisome of Saccharomyces cerevisiae through Modification of the β-Oxidation Cycle

    OpenAIRE

    de Oliveira, Valeria Cora; Maeda, Isamu; Delessert, Syndie; Poirier, Yves

    2004-01-01

    Short-chain-length-medium-chain-length polyhydroxyalkanoates were synthesized in Saccharomyces cerevisiae from intermediates of the β-oxidation cycle by expressing the polyhydroxyalkanoate synthases from Aeromonas caviae and Ralstonia eutropha in the peroxisomes. The quantity of polymer produced was increased by using a mutant of the β-oxidation-associated multifunctional enzyme with low dehydrogenase activity toward R-3-hydroxybutyryl coenzyme A.

  7. Production of medium-chain-length polyhydroxyalkanoate by Pseudomonas oleovorans grown in sugary cassava extract supplemented with andiroba oil

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    Diego Aires da Silva

    2014-12-01

    Full Text Available Pseudomonas oleovorans were grown on sugary cassava extracts supplemented with andiroba oil for the synthesis of a mediumchain- length polyhydroxyalkanoate (PHA MCL. The concentration of total sugars in the extract was approximately: 40 g/L in culture 1, 15 g/L in cultures 2 and 3, and 10 g/L in culture 4. Supplementation with 1% andiroba oil and 0.2 g/L of (NH42HPO4 was performed 6.5 hours after growth in culture 3, and supplementation with the same amount of andiroba oil and 2.4 g/L of (NH42HPO4 was performed at the beginning of growth in culture 4. The synthesis resulted mainly in 3-hydroxy-decanoate and 3-hydroxy-dodecanoate units; 3-hydroxy-butyrate, 3-hydroxy-hexanoate; and 3-hydroxy-octanoate monomers were also produced but in smaller proportions. P. oleovorans significantly accumulated PHA MCL in the deceleration phase of growth with an oxygen limitation but with sufficient nitrogen concentration to maintain cell growth. The sugary cassava extract supplemented with andiroba oil proved to be a potential substrate for PHA MCL production.

  8. Medium-chain-length polyhydroxyalkanoates synthesis by Pseudomonas putida KT2440 relA/spoT mutant: bioprocess characterization and transcriptome analysis.

    Science.gov (United States)

    Mozejko-Ciesielska, Justyna; Dabrowska, Dorota; Szalewska-Palasz, Agnieszka; Ciesielski, Slawomir

    2017-12-01

    Pseudomonas putida KT2440 is a model bacteria used commonly for medium-chain-length polyhydroxyalkanoates (mcl-PHAs) production using various substrates. However, despite many studies conducted on P. putida KT2440 strain, the molecular mechanisms of leading to mcl-PHAs synthesis in reaction to environmental stimuli are still not clear. The rearrangement of the metabolism in response to environmental stress could be controlled by stringent response that modulates the transcription of many genes in order to promote survival under nutritional deprivation conditions. Therefore, in this work we investigated the relation between mcl-PHAs synthesis and stringent response. For this study, a relA/spoT mutant of P. putida KT2440, unable to induce the stringent response, was used. Additionally, the transcriptome of this mutant was analyzed using RNA-seq in order to examine rearrangements of the metabolism during cultivation. The results show that the relA/spoT mutant of P. putida KT2440 is able to accumulate mcl-PHAs in both optimal and nitrogen limiting conditions. Nitrogen starvation did not change the efficiency of mcl-PHAs synthesis in this mutant. The transition from exponential growth to stationary phase caused significant upregulation of genes involved in transport system and nitrogen metabolism. Transcriptional regulators, including rpoS, rpoN and rpoD, did not show changes in transcript abundance when entering the stationary phase, suggesting their limited role in mcl-PHAs accumulation during stationary phase.

  9. Co-synthesis of medium-chain-length polyhydroxyalkanoates and CdS quantum dots nanoparticles in Pseudomonas putida KT2440.

    Science.gov (United States)

    Oliva-Arancibia, Barbara; Órdenes-Aenishanslins, Nicolás; Bruna, Nicolas; Ibarra, Paula S; Zacconi, Flavia C; Pérez-Donoso, José M; Poblete-Castro, Ignacio

    2017-12-20

    Microbial polymers and nanomaterials production is a promising alternative for sustainable bioeconomics. To this end, we used Pseudomonas putida KT2440 as a cell factory in batch cultures to coproduce two important nanotechnology materials- medium-chain-length (MCL)-polyhydroxyalkanoates (PHAs) and CdS fluorescent nanoparticles (i.e. quantum dots [QDots]). Due to high cadmium resistance, biomass and PHA yields were almost unaffected by coproduction conditions. Fluorescent nanocrystal biosynthesis was possible only in presence of cysteine. Furthermore, this process took place exclusively in the cell, displaying the classical emission spectra of CdS QDots under UV-light exposure. Cell fluorescence, zeta potential values, and particles size of QDots depended on cadmium concentration and exposure time. Using standard PHA-extraction procedures, the biosynthesized QDots remained associated with the biomass, and the resulting PHAs presented no traces of CdS QDots. Transmission electron microscopy located the synthesized PHAs in the cell cytoplasm, whereas CdS nanocrystals were most likely located within the periplasmic space, exhibiting no apparent interaction. This is the first report presenting the microbial coproduction of MCL-PHAs and CdS QDots in P. putida KT2440, thus constituting a foundation for further bioprocess developments and strain engineering towards the efficient synthesis of these highly relevant bioproducts for nanotechnology. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Medium chain length polyhydroxyalkanoates biosynthesis in Pseudomonas putida mt-2 is enhanced by co-metabolism of glycerol/octanoate or fatty acids mixtures.

    Science.gov (United States)

    Fontaine, Paul; Mosrati, Ridha; Corroler, David

    2017-05-01

    The synthesis of medium chain length polyhydroxyalkanoates (mcl-PHAs) by Pseudomonas putida mt-2 was investigated under nitrogen-rich then deficient conditions with glycerol/octanoate or long-chain fatty acids (LCFAs) as carbon sources. When mixed, glycerol and octanoate were co-assimilated regardless of nitrogen availability but provided that glycerol uptake has been already triggered under non-limiting nutrient conditions. This concomitant consumption allowed to enhance mcl-PHAs accumulation (up to 57% of cell dry weight (CDW)) under both non-limiting and nitrogen deficient conditions. Octanoate then mostly drove anabolism of the polyester with 3-hydroxyoctanoate (3HO) synthesized as the main monomer (83%). If the preferred PHA precursor octanoate was supplied, glycerol was mainly involved in cell growth and/or maintenance but very little in PHA production even under nitrogen starvation. P. putida cells accumulated higher amounts of mcl-PHAs when grown on mixtures of LCFAs compared to LCFAs supplied as single substrate (25% and 9% of CDW, respectively). However, only a weak enrichment of the polyester was observed after transfer of cells in a fresh nitrogen-free medium containing the same combination of LCFAs. Some typical units within the polyester were related to the LCFAs ratio supplied in the medium indicating that tailor-made monomers could be synthesized. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Production of medium-chain-length polyhydroxyalkanoates by sequential feeding of xylose and octanoic acid in engineered Pseudomonas putida KT2440

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    Le Meur Sylvaine

    2012-08-01

    Full Text Available Abstract Background Pseudomonas putida KT2440 is able to synthesize large amounts of medium-chain-length polyhydroxyalkanoates (mcl-PHAs. To reduce the substrate cost, which represents nearly 50% of the total PHA production cost, xylose, a hemicellulose derivate, was tested as the growth carbon source in an engineered P. putida KT2440 strain. Results The genes encoding xylose isomerase (XylA and xylulokinase (XylB from Escherichia coli W3110 were introduced into P. putida KT2440. The recombinant KT2440 exhibited a XylA activity of 1.47 U and a XylB activity of 0.97 U when grown on a defined medium supplemented with xylose. The cells reached a maximum specific growth rate of 0.24 h-1 and a final cell dry weight (CDW of 2.5 g L-1 with a maximal yield of 0.5 g CDW g-1 xylose. Since no mcl-PHA was accumulated from xylose, mcl-PHA production can be controlled by the addition of fatty acids leading to tailor-made PHA compositions. Sequential feeding strategy was applied using xylose as the growth substrate and octanoic acid as the precursor for mcl-PHA production. In this way, up to 20% w w-1 of mcl-PHA was obtained. A yield of 0.37 g mcl-PHA per g octanoic acid was achieved under the employed conditions. Conclusions Sequential feeding of relatively cheap carbohydrates and expensive fatty acids is a practical way to achieve more cost-effective mcl-PHA production. This study is the first reported attempt to produce mcl-PHA by using xylose as the growth substrate. Further process optimizations to achieve higher cell density and higher productivity of mcl-PHA should be investigated. These scientific exercises will undoubtedly contribute to the economic feasibility of mcl-PHA production from renewable feedstock.

  12. A reduction in growth rate of Pseudomonas putida KT2442 counteracts productivity advances in medium-chain-length polyhydroxyalkanoate production from gluconate

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    Zinn Manfred

    2011-04-01

    Full Text Available Abstract Background The substitution of plastics based on fossil raw material by biodegradable plastics produced from renewable resources is of crucial importance in a context of oil scarcity and overflowing plastic landfills. One of the most promising organisms for the manufacturing of medium-chain-length polyhydroxyalkanoates (mcl-PHA is Pseudomonas putida KT2440 which can accumulate large amounts of polymer from cheap substrates such as glucose. Current research focuses on enhancing the strain production capacity and synthesizing polymers with novel material properties. Many of the corresponding protocols for strain engineering rely on the rifampicin-resistant variant, P. putida KT2442. However, it remains unclear whether these two strains can be treated as equivalent in terms of mcl-PHA production, as the underlying antibiotic resistance mechanism involves a modification in the RNA polymerase and thus has ample potential for interfering with global transcription. Results To assess PHA production in P. putida KT2440 and KT2442, we characterized the growth and PHA accumulation on three categories of substrate: PHA-related (octanoate, PHA-unrelated (gluconate and poor PHA substrate (citrate. The strains showed clear differences of growth rate on gluconate and citrate (reduction for KT2442 > 3-fold and > 1.5-fold, respectively but not on octanoate. In addition, P. putida KT2442 PHA-free biomass significantly decreased after nitrogen depletion on gluconate. In an attempt to narrow down the range of possible reasons for this different behavior, the uptake of gluconate and extracellular release of the oxidized product 2-ketogluconate were measured. The results suggested that the reason has to be an inefficient transport or metabolization of 2-ketogluconate while an alteration of gluconate uptake and conversion to 2-ketogluconate could be excluded. Conclusions The study illustrates that the recruitment of a pleiotropic mutation, whose effects might

  13. A reduction in growth rate of Pseudomonas putida KT2442 counteracts productivity advances in medium-chain-length polyhydroxyalkanoate production from gluconate

    Science.gov (United States)

    2011-01-01

    Background The substitution of plastics based on fossil raw material by biodegradable plastics produced from renewable resources is of crucial importance in a context of oil scarcity and overflowing plastic landfills. One of the most promising organisms for the manufacturing of medium-chain-length polyhydroxyalkanoates (mcl-PHA) is Pseudomonas putida KT2440 which can accumulate large amounts of polymer from cheap substrates such as glucose. Current research focuses on enhancing the strain production capacity and synthesizing polymers with novel material properties. Many of the corresponding protocols for strain engineering rely on the rifampicin-resistant variant, P. putida KT2442. However, it remains unclear whether these two strains can be treated as equivalent in terms of mcl-PHA production, as the underlying antibiotic resistance mechanism involves a modification in the RNA polymerase and thus has ample potential for interfering with global transcription. Results To assess PHA production in P. putida KT2440 and KT2442, we characterized the growth and PHA accumulation on three categories of substrate: PHA-related (octanoate), PHA-unrelated (gluconate) and poor PHA substrate (citrate). The strains showed clear differences of growth rate on gluconate and citrate (reduction for KT2442 > 3-fold and > 1.5-fold, respectively) but not on octanoate. In addition, P. putida KT2442 PHA-free biomass significantly decreased after nitrogen depletion on gluconate. In an attempt to narrow down the range of possible reasons for this different behavior, the uptake of gluconate and extracellular release of the oxidized product 2-ketogluconate were measured. The results suggested that the reason has to be an inefficient transport or metabolization of 2-ketogluconate while an alteration of gluconate uptake and conversion to 2-ketogluconate could be excluded. Conclusions The study illustrates that the recruitment of a pleiotropic mutation, whose effects might reach deep into

  14. Application of polyhydroxyalkanoate granules for sizing of paper.

    Science.gov (United States)

    Bourbonnais, Robert; Marchessault, Robert H

    2010-04-12

    Polyhydroxyalkanoates (PHAs) are characterized by the chemistry of the biodegradable inclusions inside the microbial membrane. They are produced by a wide variety of bacteria, where they function as energy and carbon storage materials. This intracellular Bioplastic forms a stable latex suitable for surface treatments of paper such as sizing and coating. In this work, we compare native granules and artificial granules made from market poly(3-hydroxybutyrate) (PHB) and poly(3-hydroxybutyrate-co-hydroxyvalerate), P(3HB-co-3HV), for their ability as sizing agent. Paper sizing was assayed by measuring the resistance of sized paper to penetration by aqueous fluids. Our results indicate that the sizing effect of PHAs is dependent on several factors, such as, paper drying temperature, drying time, pressure, and polymer composition, that is, homopolymer, random copolymer, and texture of granules. The sizing efficiency of the copolymer is generally poor compared to the PHB homopolymer. In addition to water permeability, the tensile strength of sized paper was measured and physical properties of granule suspensions were recorded using SEM microscopy, X-ray diffraction, and dynamic light scattering.

  15. Quantitative 'Omics Analyses of Medium Chain Length Polyhydroxyalkanaote Metabolism in Pseudomonas putida LS46 Cultured with Waste Glycerol and Waste Fatty Acids.

    Science.gov (United States)

    Fu, Jilagamazhi; Sharma, Parveen; Spicer, Vic; Krokhin, Oleg V; Zhang, Xiangli; Fristensky, Brian; Cicek, Nazim; Sparling, Richard; Levin, David B

    2015-01-01

    Transcriptomes and proteomes of Pseudomonas putida LS46 cultured with biodiesel-derived waste glycerol or waste free fatty acids, as sole carbon sources, were compared under conditions that were either permissive or non-permissive for synthesis of medium chain length polyhydroxyalkanoates (mcl-PHA). The objectives of this study were to elucidate mechanisms that influence activation of biopolymer synthesis, intra-cellular accumulation, and monomer composition, and determine if these were physiologically specific to the carbon sources used for growth of P. putida LS46. Active mcl-PHA synthesis by P. putida LS46 was associated with high expression levels of key mcl-PHA biosynthesis genes and/or gene products including monomer-supplying proteins, PHA synthases, and granule-associated proteins. 'Omics data suggested that expression of these genes were regulated by different genetic mechanisms in P. putida LS46 cells in different physiological states, when cultured on the two waste carbon sources. Optimal polymer production by P. putida LS46 was primarily limited by less efficient glycerol metabolism during mcl-PHA synthesis on waste glycerol. Mapping the 'Omics data to the mcl-PHA biosynthetic pathway revealed significant variations in gene expression, primarily involved in: 1) glycerol transportation; 2) enzymatic reactions that recycle reducing equivalents and produce key mcl-PHA biosynthesis pathway intermediates (e.g. NADH/NADPH, acetyl-CoA). Active synthesis of mcl-PHAs was observed during exponential phase in cultures with waste free fatty acids, and was associated with the fatty acid beta-oxidation pathway. A putative Thioesterase in the beta-oxidation pathway that may regulate the level of fatty acid beta-oxidation intermediates, and thus carbon flux to mcl-PHA biosynthesis, was highly up-regulated. Finally, the data suggested that differences in expression of selected fatty acid metabolism and mcl-PHA monomer-supplying enzymes may play a role in determining the

  16. Quantitative ‘Omics Analyses of Medium Chain Length Polyhydroxyalkanaote Metabolism in Pseudomonas putida LS46 Cultured with Waste Glycerol and Waste Fatty Acids

    Science.gov (United States)

    Fu, Jilagamazhi; Sharma, Parveen; Spicer, Vic; Krokhin, Oleg V.; Zhang, Xiangli; Fristensky, Brian; Cicek, Nazim; Sparling, Richard; Levin, David. B.

    2015-01-01

    Transcriptomes and proteomes of Pseudomonas putida LS46 cultured with biodiesel-derived waste glycerol or waste free fatty acids, as sole carbon sources, were compared under conditions that were either permissive or non-permissive for synthesis of medium chain length polyhydroxyalkanoates (mcl-PHA). The objectives of this study were to elucidate mechanisms that influence activation of biopolymer synthesis, intra-cellular accumulation, and monomer composition, and determine if these were physiologically specific to the carbon sources used for growth of P. putida LS46. Active mcl-PHA synthesis by P. putida LS46 was associated with high expression levels of key mcl-PHA biosynthesis genes and/or gene products including monomer-supplying proteins, PHA synthases, and granule-associated proteins. ‘Omics data suggested that expression of these genes were regulated by different genetic mechanisms in P. putida LS46 cells in different physiological states, when cultured on the two waste carbon sources. Optimal polymer production by P. putida LS46 was primarily limited by less efficient glycerol metabolism during mcl-PHA synthesis on waste glycerol. Mapping the ‘Omics data to the mcl-PHA biosynthetic pathway revealed significant variations in gene expression, primarily involved in: 1) glycerol transportation; 2) enzymatic reactions that recycle reducing equivalents and produce key mcl-PHA biosynthesis pathway intermediates (e.g. NADH/NADPH, acetyl-CoA). Active synthesis of mcl-PHAs was observed during exponential phase in cultures with waste free fatty acids, and was associated with the fatty acid beta-oxidation pathway. A putative Thioesterase in the beta-oxidation pathway that may regulate the level of fatty acid beta-oxidation intermediates, and thus carbon flux to mcl-PHA biosynthesis, was highly up-regulated. Finally, the data suggested that differences in expression of selected fatty acid metabolism and mcl-PHA monomer-supplying enzymes may play a role in determining

  17. Quantitative 'Omics Analyses of Medium Chain Length Polyhydroxyalkanaote Metabolism in Pseudomonas putida LS46 Cultured with Waste Glycerol and Waste Fatty Acids.

    Directory of Open Access Journals (Sweden)

    Jilagamazhi Fu

    Full Text Available Transcriptomes and proteomes of Pseudomonas putida LS46 cultured with biodiesel-derived waste glycerol or waste free fatty acids, as sole carbon sources, were compared under conditions that were either permissive or non-permissive for synthesis of medium chain length polyhydroxyalkanoates (mcl-PHA. The objectives of this study were to elucidate mechanisms that influence activation of biopolymer synthesis, intra-cellular accumulation, and monomer composition, and determine if these were physiologically specific to the carbon sources used for growth of P. putida LS46. Active mcl-PHA synthesis by P. putida LS46 was associated with high expression levels of key mcl-PHA biosynthesis genes and/or gene products including monomer-supplying proteins, PHA synthases, and granule-associated proteins. 'Omics data suggested that expression of these genes were regulated by different genetic mechanisms in P. putida LS46 cells in different physiological states, when cultured on the two waste carbon sources. Optimal polymer production by P. putida LS46 was primarily limited by less efficient glycerol metabolism during mcl-PHA synthesis on waste glycerol. Mapping the 'Omics data to the mcl-PHA biosynthetic pathway revealed significant variations in gene expression, primarily involved in: 1 glycerol transportation; 2 enzymatic reactions that recycle reducing equivalents and produce key mcl-PHA biosynthesis pathway intermediates (e.g. NADH/NADPH, acetyl-CoA. Active synthesis of mcl-PHAs was observed during exponential phase in cultures with waste free fatty acids, and was associated with the fatty acid beta-oxidation pathway. A putative Thioesterase in the beta-oxidation pathway that may regulate the level of fatty acid beta-oxidation intermediates, and thus carbon flux to mcl-PHA biosynthesis, was highly up-regulated. Finally, the data suggested that differences in expression of selected fatty acid metabolism and mcl-PHA monomer-supplying enzymes may play a role in

  18. Biosynthesis of medium chain length alkanes for bio-aviation fuel by metabolic engineered Escherichia coli.

    Science.gov (United States)

    Wang, Meng; Nie, Kaili; Cao, Hao; Xu, Haijun; Fang, Yunming; Tan, Tianwei; Baeyens, Jan; Liu, Luo

    2017-09-01

    The aim of this work was to study the synthesis of medium-chain length alkanes (MCLA), as bio-aviation product. To control the chain length of alkanes and increase the production of MCLA, Escherichia coli cells were engineered by incorporating (i) a chain length specific thioesterase from Umbellularia californica (UC), (ii) a plant origin acyl carrier protein (ACP) gene and (iii) the whole fatty acid synthesis system (FASs) from Jatropha curcas (JC). The genetic combination was designed to control the product spectrum towards optimum MCLA. Decanoic, lauric and myristic acid were produced at concentrations of 0.011, 0.093 and 1.657mg/g, respectively. The concentration of final products nonane, undecane and tridecane were 0.00062mg/g, 0.0052mg/g, and 0.249mg/g respectively. Thioesterase from UC controlled the fatty acid chain length in a range of 10-14 carbons and the ACP gene with whole FASs from JC significantly increased the production of MCLA. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Development of environmentally friendly coatings and paints using medium-chain-length poly(3-hydroxyalkanoates) as the polymer binder

    NARCIS (Netherlands)

    Walle, van der G.A.M.; Buisman, F.J.H.; Weusthuis, R.A.; Eggink, G.

    1999-01-01

    Unsaturated medium-chain-length poly(3-hydroxyalkanoates) (mcl-PHAs) produced by Pseudomonas putida from linseed oil fatty acids (LOFA) and tall oil fatty acids (TOFA), were used as the polymer binder in the formulation of high solid alkyd-like paints. The relatively high concentration of

  20. Development of a bioprocess to convert PET derived terephthalic acid and biodiesel derived glycerol to medium chain length polyhydroxyalkanoate

    Energy Technology Data Exchange (ETDEWEB)

    Kenny, Shane T.; Nikodinovic Runic, Jasmina; O' Connor, Kevin E. [University College Dublin (Ireland). School of Biomolecular and Biomedical Sciences; Kaminsky, Walter [Hamburg Univ. (Germany). Inst. of Technical and Macromolecular Chemistry; Woods, Trevor; Babu, Ramesh P. [Dublin Univ. (Ireland). Materials Ireland Polymer Research Center

    2012-08-15

    Sodium terephthalate (TA) produced from a PET pyrolysis product and waste glycerol (WG) from biodiesel manufacture were supplied to Pseudomonas putida GO16 in a fed-batch bioreactor. Six feeding strategies were employed by altering the sequence of TA and WG feeding. P. putida GO16 reached 8.70 g/l cell dry weight (CDW) and 2.61 g/l PHA in 48 h when grown on TA alone. When TA and WG were supplied in combination, biomass productivity (g/l/h) was increased between 1.3- and 1.7-fold and PHA productivity (g/l/h) was increased 1.8- to 2.2-fold compared to TA supplied alone. The monomer composition of the PHA accumulated from TA or WG was predominantly composed of 3-hydroxydecanoic acid. PHA monomers 3-hydroxytetradeeanoic acid and 3-hydroxytetradecenoic acid were not present in PHA accumulated from TA alone but were present when WG was supplied to the fermentation. When WG was either the sole carbon source or the predominant carbon source supplied to the fermentation the molecular weight of PHA accumulated was lower compared to PHA accumulated when TA was supplied as the sole substrate. Despite similarities in data for the properties of the polymers, PHAs produced with WG present in the PHA accumulation phase were tacky while PHA produced where TA was the sole carbon substrate in the polymer accumulation phase exhibited little or no tackiness at room temperature. The co-feeding of WG to fermentations allows for increased utilisation of TA. The order of feeding of WG and TA has an effect on TA utilisation and polymer properties. (orig.)

  1. Novel extracellular medium-chain-length polyhydroxyalkanoate depolymerase from Streptomyces exfoliatus K10 DSMZ 41693

    DEFF Research Database (Denmark)

    Martinez, Virginia; de Santos, Patricia Gómez; García-Hidalgo, Javier

    2015-01-01

    produced as an extracellular active form in Rhodococcus and purified by two consecutive hydrophobic chromatographic steps. Matrix-assisted laser desorption-time-of-flight (MALDI-TOF) analysis of the purified enzyme revealed a monomer of 27.6 kDa with a midpoint transition temperature of 44.2 °C. Remarkably......, the activity is significantly enhanced by low concentrations of nonionic and anionic detergents and thermal stability is improved by the presence of 10 % glycerol. PhaZSex2 is an endo-exohydrolase that cleaves both large and small PHA molecules, producing (R)-3-hydroxyoctanoic acid monomers as the main...

  2. Crystallization and initial X-ray analysis of polyhydroxyalkanoate granule-associated protein from Aeromonas hydrophila

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Minglian; Li, Zhenguo; Zheng, Wei; Lou, Zhiyong [MOE Key Laboratory of Protein Science, Department of Biological Sciences and Biotechnology, Tsinghua University, Beijing 100084 (China); Chen, Guo-Qiang, E-mail: chengq@stu.edu.cn [MOE Key Laboratory of Protein Science, Department of Biological Sciences and Biotechnology, Tsinghua University, Beijing 100084 (China); Multidisciplinary Research Center, Shantou University, Shantou 515063, Guangdong (China)

    2006-08-01

    The phasin PhaP{sub Ah} from A. hydrophila strain 4AK4 was crystallized using the hanging-drop vapour-diffusion method. Polyhydroxyalkanoate (PHA) granule-associated proteins (phasins) were discovered in PHA-accumulating bacteria. They play a crucial role as a structural protein during initial PHA-granule formation and granule growth and also serve as interfaces for granule stabilization in vivo. The phasin PhaP{sub Ah} from Aeromonas hydrophila strain 4AK4 was crystallized using the hanging-drop vapour-diffusion method. Single crystals were cryocooled for X-ray diffraction analysis. The phasin crystals belonged to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 80.8, b = 108.9, c = 134.4 Å.

  3. Development of environmentally friendly coatings and paints using medium-chain-length poly(3-hydroxyalkanoates) as the polymer binder.

    Science.gov (United States)

    van der Walle, G A; Buisman, G J; Weusthuis, R A; Eggink, G

    1999-01-01

    Unsaturated medium-chain-length poly(3-hydroxyalkanoates) (mcl-PHAs) produced by Pseudomonas putida from linseed oil fatty acids (LOFA) and tall oil fatty acids (TOFA), were used as the polymer binder in the formulation of high solid alkyd-like paints. The relatively high concentration of unsaturated alkyl side chains incorporated into the PHA resins resulted in oxidative drying PHA paints having excellent coating properties. The homogeneously pigmented PHA coatings yielded high-gloss, smooth and strong films upon curing and showed an excellent flexibility, a good adhesion to different substrates, cohesive film properties and resistance to chipping.

  4. New insights into the effect of medium-chain-length lactones on yeast membranes. Importance of the culture medium.

    Science.gov (United States)

    Ta, Thi Minh Ngoc; Cao-Hoang, Lan; Phan-Thi, Hanh; Tran, Hai Dang; Souffou, Nadhuirata; Gresti, Joseph; Marechal, Pierre-André; Cavin, Jean-François; Waché, Yves

    2010-07-01

    In hydrophobic compounds biotechnology, medium-chain-length metabolites often perturb cell activity. Their effect is usually studied in model conditions of growth in glucose media. Here, we study whether culture on lipids has an impact on the resistance of Yarrowia lipolytica to such compounds: Cells were cultured on glucose or oleate and submitted to gamma-dodecalactone. After a 60-min exposure to 3 g L(-1), about 80% of the glucose-grown cells (yeast extract peptone dextrose (YPD) cells) had lost their cultivability, 38% their membrane integrity, and 31% their reducing capacity as shown with propidium iodide and methylene blue, respectively. For oleate-grown cells, treatment at 6 g L(-1) did not alter cultivability despite some transient loss of membrane integrity from 3 g L(-1). It was shown with diphenylhexatriene and 1-(4-trimethylammoniumphenyl)-6-phenyl-1,3,5-hexatriene that oleate-grown cells had membranes more fluid and less sensitive to the lactone-induced fluidization. Analyses revealed also higher contents of ergosterol but, for YPD- and minimum-oleate-grown cells (YNBO cells), the addition of lactone provoked a decrease in the concentration of ergosterol in a way similar to the depletion by methyl-beta-cyclodextrin and an important membrane fluidization. Ergosterol depletion or incorporation increased or decreased, respectively, cell sensitivity to lactone. This study shows that the embedment of oleate moieties into membranes as well as higher concentrations of sterol play a role in the higher resistance to lactone of oleate-grown cells (YPO cells). Similar oleate-induced increase in resistance was also observed for Rhodotorula and Candida strains able to grow on oleate as the sole carbon source whereas Saccharomyces and Sporidiobolus cells were more sensitive after induction.

  5. Production of Medium-Chain-Length Poly(3-Hydroxyalkanoates from Saponified Palm Kernel Oil by Pseudomonas putida: Kinetics of Batch and Fed-Batch Fermentations

    Directory of Open Access Journals (Sweden)

    Annuar, M. S. M.

    2006-01-01

    Full Text Available The kinetics of medium-chain-length poly(3-hydroxyalkanoates, PHAMCL production by Pseudomonas putida PGA1 in batch and fed-batch fermentations were studied. With saponified palm kernel oil (SPKO supplying the free fatty acids mixture as the sole carbon and energy source, PHAMCL accumulation is encouraged under ammonium-limited condition, which is a nitrogen stress environment. The amount of PHAMCL accumulated and its specific production rate, qPHA were influenced by the residual ammonium concentration level in the culture medium. It was observed that in both fermentation modes, when the residual ammonium was exhausted (< 0.05 gL-1, the PHAMCL accumulation (11.9% and qPHA (0.0062 h-1 were significantly reduced. However, this effect can be reversed by feeding low amount of ammonium to the culture, resulting in significantly improved PHAMCL yield (71.4% and specific productivity (0.6 h-1. It is concluded that the feeding of low ammonium concentration to the culture medium during the PHAMCL accumulation has a positive effect on sustaining the PHAMCL biosynthetic capability of the organism. It was also found that increasing SPKO concentration in the medium significantly reduced (up to 50% the volumetric oxygen transfer coefficient (KLa of the fermentation system.

  6. In vivo and in vitro depolymerizations of intracellular medium-chain-length poly-3-hydroxyalkanoates produced by Pseudomonas putida Bet001.

    Science.gov (United States)

    Anis, Siti Nor Syairah; Mohamad Annuar, Mohamad Suffian; Simarani, Khanom

    2017-09-14

    In vivo and in vitro depolymerizations of intracellular medium-chain-length poly-3-hydroxyalkanoates (mcl-PHA) in Pseudomonas putida Bet001 grown on lauric acid was studied. Both processes were studied under optimum conditions for mcl-PHA depolymerization viz. 0.2 M Tris-HCl buffer, pH 9, ionic strength (I) = 0.2 M at 30°C. For in vitro depolymerization studies, cell-free system was obtained from lysing bacterial cells suspension by ultrasonication at optimum conditions (frequency 37 kHz, 30% of power output, <25°C for 120 min). The comparison between in vivo and in vitro depolymerizations of intracellular mcl-PHA was made. In vitro depolymerization showed lower depolymerization rate but higher yield compared to in vivo depolymerization. The monomer liberation rate reflected the mol% distribution of the initial polymer subunit composition, and the resulting direct individual products of depolymerization were identical for both in vivo and in vitro processes. It points to exo-type reaction for both processes, and potential biological route to chiral molecules.

  7. Transcriptome analysis of Pseudomonas mediterranea and P. corrugata plant pathogens during accumulation of medium-chain-length PHAs by glycerol bioconversion.

    Science.gov (United States)

    Licciardello, Grazia; Ferraro, Rosario; Russo, Marcella; Strozzi, Francesco; Catara, Antonino F; Bella, Patrizia; Catara, Vittoria

    2017-07-25

    Pseudomonas corrugata and P. mediterranea are soil inhabitant bacteria, generally living as endophytes on symptomless plants and bare soil, but also capable of causing plant diseases. They share a similar genome size and a high proteome similarity. P. corrugata produces many biomolecules which play an important role in bacterial cell survival and fitness. Both species produce different medium-chain-length PHAs (mcl-PHAs) from the bioconversion of glycerol to a transparent film in P. mediterranea and a sticky elastomer in P. corrugata. In this work, using RNA-seq we investigated the transcriptional profiles of both bacteria at the early stationary growth phase with glycerol as the carbon source. Quantitative analysis of P. mediterranea transcripts versus P. corrugata revealed that 1756 genes were differentially expressed. A total of 175 genes were significantly upregulated in P. mediterranea, while 217 were downregulated. The largest group of upregulated genes was related to transport systems and stress response, energy and central metabolism, and carbon metabolism. Expression levels of most genes coding for enzymes related to PHA biosynthesis and central metabolic pathways showed no differences or only slight variations in pyruvate metabolism. The most relevant result was the significantly increased expression in P. mediterranea of genes involved in alginate production, an important exopolysaccharide, which in other Pseudomonas spp. plays a key role as a virulence factor or in stress tolerance and shows many industrial applications. In conclusion, the results provide useful information on the co-production of mcl-PHAs and alginate from glycerol as carbon source by P. mediterranea in the design of new strategies of genetic regulation to improve the yield of bioproducts or bacterial fitness. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Novel polyhydroxyalkanoate copolymers produced in Pseudomonas putida by metagenomic polyhydroxyalkanoate synthases.

    Science.gov (United States)

    Cheng, Jiujun; Charles, Trevor C

    2016-09-01

    Bacterially produced biodegradable polyhydroxyalkanoates (PHAs) with versatile properties can be achieved using different PHA synthases (PhaCs). This work aims to expand the diversity of known PhaCs via functional metagenomics and demonstrates the use of these novel enzymes in PHA production. Complementation of a PHA synthesis-deficient Pseudomonas putida strain with a soil metagenomic cosmid library retrieved 27 clones expressing either class I, class II, or unclassified PHA synthases, and many did not have close sequence matches to known PhaCs. The composition of PHA produced by these clones was dependent on both the supplied growth substrates and the nature of the PHA synthase, with various combinations of short-chain-length (SCL) and medium-chain-length (MCL) PHA. These data demonstrate the ability to isolate diverse genes for PHA synthesis by functional metagenomics and their use for the production of a variety of PHA polymer and copolymer mixtures.

  9. Production of Polyhydroxyalkanoates from Sludge Palm Oil Using Pseudomonas putida S12.

    Science.gov (United States)

    Kang, Du-Kyeong; Lee, Cho-Ryong; Lee, Sun Hee; Bae, Jung-Hoon; Park, Young-Kwon; Rhee, Young Ha; Sung, Bong Hyun; Sohn, Jung-Hoon

    2017-05-28

    Polyhydroxyalkanoates (PHAs) are biodegradable plastics produced by bacteria, but their use in diverse applications is prohibited by high production costs. To reduce these costs, the conversion by Pseudomonas strains of P HAs from crude s ludge p alm oil ( SPO) a s an inexpensive renewable raw material was tested. Pseudomonas putida S12 was found to produce the highest yield (~41%) of elastomeric medium-chain-length (MCL)-PHAs from SPO. The MCL-PHA characteristics were analyzed by gas-chromatography/mass spectrometry, gel permeation chromatography, and differential scanning calorimetry. These findings may contribute to more widespread use of PHAs by reducing PHA production costs.

  10. Influence of growth stage on activities of polyhydroxyalkanoate (PHA polymerase and PHA depolymerase in Pseudomonas putida U

    Directory of Open Access Journals (Sweden)

    Zinn Manfred

    2010-10-01

    Full Text Available Abstract Background Medium chain length (mcl- polyhydroxyalkanoates (PHA are synthesized by many bacteria in the cytoplasm as storage compounds for energy and carbon. The key enzymes for PHA metabolism are PHA polymerase (PhaC and depolymerase (PhaZ. Little is known of how mcl-PHA accumulation and degradation are controlled. It has been suggested that overall PHA metabolism is regulated by the β-oxidation pathway of which the flux is governed by intracellular ratios of [NADH]/[NAD] and [acetyl-CoA]/[CoA]. Another level of control could relate to modulation of the activities of PhaC and PhaZ. In order to investigate the latter, assays for in vitro activity measurements of PhaC and PhaZ in crude cell extracts are necessary. Results Two in vitro assays were developed which allow the measurement of PhaC and PhaZ activities in crude cell extracts of Pseudomonas putida U. Using the assays, it was demonstrated that the activity of PhaC decreased 5-fold upon exponential growth on nitrogen limited medium and octanoate. In contrast, the activity of PhaZ increased only 1.5-fold during growth. One reason for the changes in the enzymatic activity of PhaC and PhaZ could relate to a change in interaction with the phasin surface proteins on the PHA granule. SDS-PAGE analysis of isolated PHA granules demonstrated that during growth, the ratio of [phasins]/[PHA] decreased. In addition, it was found that after eliminating phasins (PhaF and PhaI from the granules PhaC activity decreased further. Conclusion Using the assays developed in this study, we followed the enzymatic activities of PhaC and PhaZ during growth and correlated them to the amount of phasins on the PHA granules. It was found that in P. putida PhaC and PhaZ are concomitantly active, resulting in parallel synthesis and degradation of PHA. Moreover PhaC activity was found to be decreased, whereas PhaZ activity increased during growth. Availability of phasins on PHA granules affected the activity of

  11. High Polyhydroxybutyrate Production in Pseudomonas extremaustralis Is Associated with Differential Expression of Horizontally Acquired and Core Genome Polyhydroxyalkanoate Synthase Genes

    Science.gov (United States)

    Catone, Mariela V.; Ruiz, Jimena A.; Castellanos, Mildred; Segura, Daniel; Espin, Guadalupe; López, Nancy I.

    2014-01-01

    Pseudomonas extremaustralis produces mainly polyhydroxybutyrate (PHB), a short chain length polyhydroxyalkanoate (sclPHA) infrequently found in Pseudomonas species. Previous studies with this strain demonstrated that PHB genes are located in a genomic island. In this work, the analysis of the genome of P. extremaustralis revealed the presence of another PHB cluster phbFPX, with high similarity to genes belonging to Burkholderiales, and also a cluster, phaC1ZC2D, coding for medium chain length PHA production (mclPHA). All mclPHA genes showed high similarity to genes from Pseudomonas species and interestingly, this cluster also showed a natural insertion of seven ORFs not related to mclPHA metabolism. Besides PHB, P. extremaustralis is able to produce mclPHA although in minor amounts. Complementation analysis demonstrated that both mclPHA synthases, PhaC1 and PhaC2, were functional. RT-qPCR analysis showed different levels of expression for the PHB synthase, phbC, and the mclPHA synthases. The expression level of phbC, was significantly higher than the obtained for phaC1 and phaC2, in late exponential phase cultures. The analysis of the proteins bound to the PHA granules showed the presence of PhbC and PhaC1, whilst PhaC2 could not be detected. In addition, two phasin like proteins (PhbP and PhaI) associated with the production of scl and mcl PHAs, respectively, were detected. The results of this work show the high efficiency of a foreign gene (phbC) in comparison with the mclPHA core genome genes (phaC1 and phaC2) indicating that the ability of P. extremaustralis to produce high amounts of PHB could be explained by the different expression levels of the genes encoding the scl and mcl PHA synthases. PMID:24887088

  12. High polyhydroxybutyrate production in Pseudomonas extremaustralis is associated with differential expression of horizontally acquired and core genome polyhydroxyalkanoate synthase genes.

    Directory of Open Access Journals (Sweden)

    Mariela V Catone

    Full Text Available Pseudomonas extremaustralis produces mainly polyhydroxybutyrate (PHB, a short chain length polyhydroxyalkanoate (sclPHA infrequently found in Pseudomonas species. Previous studies with this strain demonstrated that PHB genes are located in a genomic island. In this work, the analysis of the genome of P. extremaustralis revealed the presence of another PHB cluster phbFPX, with high similarity to genes belonging to Burkholderiales, and also a cluster, phaC1ZC2D, coding for medium chain length PHA production (mclPHA. All mclPHA genes showed high similarity to genes from Pseudomonas species and interestingly, this cluster also showed a natural insertion of seven ORFs not related to mclPHA metabolism. Besides PHB, P. extremaustralis is able to produce mclPHA although in minor amounts. Complementation analysis demonstrated that both mclPHA synthases, PhaC1 and PhaC2, were functional. RT-qPCR analysis showed different levels of expression for the PHB synthase, phbC, and the mclPHA synthases. The expression level of phbC, was significantly higher than the obtained for phaC1 and phaC2, in late exponential phase cultures. The analysis of the proteins bound to the PHA granules showed the presence of PhbC and PhaC1, whilst PhaC2 could not be detected. In addition, two phasin like proteins (PhbP and PhaI associated with the production of scl and mcl PHAs, respectively, were detected. The results of this work show the high efficiency of a foreign gene (phbC in comparison with the mclPHA core genome genes (phaC1 and phaC2 indicating that the ability of P. extremaustralis to produce high amounts of PHB could be explained by the different expression levels of the genes encoding the scl and mcl PHA synthases.

  13. Up-cycling of PET (polyethylene terephthalate) to the biodegradable plastic PHA (polyhydroxyalkanoate).

    Science.gov (United States)

    Kenny, Shane T; Runic, Jasmina Nikodinovic; Kaminsky, Walter; Woods, Trevor; Babu, Ramesh P; Keely, Chris M; Blau, Werner; O'Connor, Kevin E

    2008-10-15

    The conversion of the petrochemical polymer polyethylene terephthalate (PET) to a biodegradable plastic polyhydroxyal-kanoate (PHA) is described here. PET was pyrolised at 450 degrees C resulting in the production of a solid, liquid, and gaseous fraction. The liquid and gaseous fractions were burnt for energy recovery, whereas the solid fraction terephthalic acid (TA) was used as the feedstock for bacterial production of PHA. Strains previously reported to grow on TA were unable to accumulate PHA. We therefore isolated bacteria from soil exposed to PET granules at a PET bottle processing plant From the 32 strains isolated, three strains capable of accumulation of medium chain length PHA (mclPHA) from TA as a sole source of carbon and energy were selected for further study. These isolates were identified using 16S rDNA techniques as P. putida (GO16), P. putida (GO19), and P. frederiksbergensis (GO23). P. putida GO16 and GO19 accumulate PHA composed predominantly of a 3-hydroxydecanoic acid monomer while P. frederiksbergensis GO23 accumulates 3-hydroxydecanoic acid as the predominant monomer with increased amounts of 3-hydroxydodecanoic acid and 3-hydroxydodecenoic acid compared to the other two strains. PHA was detected in all three strains when nitrogen depleted below detectable levels in the growth medium. Strains GO16 and GO19 accumulate PHA at a maximal rate of approximately 8.4 mg PHA/l/h for 12 h before the rate of PHA accumulation decreased dramatically. Strain GO23 accumulates PHA at a lower maximal rate of 4.4 mg PHA/l/h but there was no slow down in the rate of PHA accumulation over time. Each of the PHA polymers is a thermoplastic with the onset of thermal degradation occurring around 308 degrees C with the complete degradation occurring by 370 degrees C. The molecular weight ranged from 74 to 123 kDa. X-ray diffraction indicated crystallinity of the order of 18-31%. Thermal analysis shows a low glass transition (-53 degrees C) with a broad melting

  14. Microbial production of polyhydroxyalkanoate block copolymer by recombinant Pseudomonas putida.

    Science.gov (United States)

    Li, Shi Yan; Dong, Cui Ling; Wang, Shen Yu; Ye, Hai Mu; Chen, Guo-Qiang

    2011-04-01

    Polyhydroxyalkanoate (PHA) synthesis genes phaPCJ(Ac) cloned from Aeromonas caviae were transformed into Pseudomonas putida KTOY06ΔC, a mutant of P. putida KT2442, resulting in the ability of the recombinant P. putida KTOY06ΔC (phaPCJ(A.c)) to produce a short-chain-length and medium-chain-length PHA block copolymer consisting of poly-3-hydroxybutyrate (PHB) as one block and random copolymer of 3-hydroxyvalerate (3HV) and 3-hydroxyheptanoate (3HHp) as another block. The novel block polymer was studied by differential scanning calorimetry (DSC), nuclear magnetic resonance, and rheology measurements. DSC studies showed the polymer to possess two glass transition temperatures (T(g)), one melting temperature (T(m)) and one cool crystallization temperature (T(c)). Rheology studies clearly indicated a polymer chain re-arrangement in the copolymer; these studies confirmed the polymer to be a block copolymer, with over 70 mol% homopolymer (PHB) of 3-hydroxybutyrate (3HB) as one block and around 30 mol% random copolymers of 3HV and 3HHp as the second block. The block copolymer was shown to have the highest tensile strength and Young's modulus compared with a random copolymer with similar ratio and a blend of homopolymers PHB and PHVHHp with similar ratio. Compared with other commercially available PHA including PHB, PHBV, PHBHHx, and P3HB4HB, the short-chain- and medium-chain-length block copolymer PHB-b-PHVHHp showed differences in terms of mechanical properties and should draw more attentions from the PHA research community. © Springer-Verlag 2010

  15. Use of a mannitol rich ensiled grass press juice (EGPJ) as a sole carbon source for polyhydroxyalkanoates (PHAs) production through high cell density cultivation.

    Science.gov (United States)

    Cerrone, Federico; Davis, Reeta; Kenny, Shane T; Woods, Trevor; O'Donovan, Anthonia; Gupta, Vijai Kumar; Tuohy, Maria; Babu, Ramesh P; O'Kiely, Padraig; O'Connor, Kevin

    2015-09-01

    This study demonstrates the use of a mannitol rich ensiled grass press juice (EGPJ) as a renewable carbon substrate for polyhydroxyalkanoates (PHA) production in shaking flask experiments and fed-batch stirred tank reactor cultivations. Fed-batch cultivations of Burkholderia sacchari IPT101 using EGPJ as sole carbon source produced 44.5 g/L CDW containing 33% polyhydroxybutyrate (PHB) in 36 h, while Pseudomonas chlororaphis IMD555 produced a CDW of 37 g/L containing 10% of medium chain length polyhydroxyalkanoates (mcl-PHA) in 34 h. PHB and mcl-PHA extracted from B. sacchari IPT101 and P. chlororaphis IMD555, grown on EGPJ, had a molecular weight of 548 kg/mol and 115.4 kg/mol, respectively. While mcl-PHA can be produced from EGPJ, PHB production is more interesting as there is a 4-fold higher volumetric productivity compared to mcl-PHA. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Occurrence, metabolism, metabolic role, and industrial uses of bacterial polyhydroxyalkanoates.

    OpenAIRE

    Anderson, A J; Dawes, E A

    1990-01-01

    Polyhydroxyalkanoates (PHAs), of which polyhydroxybutyrate (PHB) is the most abundant, are bacterial carbon and energy reserve materials of widespread occurrence. They are composed of 3-hydroxyacid monomer units and exist as a small number of cytoplasmic granules per cell. The properties of the C4 homopolymer PHB as a biodegradable thermoplastic first attracted industrial attention more than 20 years ago. Copolymers of C4 (3-hydroxybutyrate [3HB]) and C5 (3-hydroxyvalerate [3HV]) monomer unit...

  17. Bacterial polyhydroxyalkanoates: Still fabulous?

    Science.gov (United States)

    Możejko-Ciesielska, Justyna; Kiewisz, Robert

    2016-11-01

    Bacterial polyhydroxyalkanoates (PHA) are polyesters accumulated as carbon and energy storage materials under limited growth conditions in the presence of excess carbon sources. They have been developed as biomaterials with unique properties for the past many years being considered as a potential substitute for conventional non-degradable plastics. Due to the increasing concern towards global climate change, depleting petroleum resource and problems with an utilization of a growing number of synthetic plastics, PHAs have gained much more attention from industry and research. These environmentally friendly microbial polymers have great potential in biomedical, agricultural, and industrial applications. However, their production on a large scale is still limited. This paper describes the backgrounds of PHAs and discussed the current state of knowledge on the polyhydroxyalkanoates. Ability of bacteria to convert different carbon sources to PHAs, the opportunities and challenges of their introduction to global market as valuable renewable products have been also discussed. Copyright © 2016 Elsevier GmbH. All rights reserved.

  18. Efficient production of polyhydroxyalkanoates (PHAs) from Pseudomonas mendocina PSU using a biodiesel liquid waste (BLW) as the sole carbon source.

    Science.gov (United States)

    Chanasit, Wankuson; Hodgson, Brian; Sudesh, Kumar; Umsakul, Kamontam

    2016-07-01

    Conditions for the optimal production of polyhydroxyalkanoate (PHA) by Pseudomonas mendocina PSU using a biodiesel liquid waste (BLW) were determined by response surface methodology. These were an initial carbon to nitrogen ratio (C/N) of 40 (mole/mole), an initial pH of 7.0, and a temperature of 35 °C. A biomass and PHA concentration of 3.65 g/L and about 2.6 g/L (77% DCW), respectively, were achieved in a growth associated process using 20 g/L glycerol in the BLW after 36 h of exponential growth. The PHA monomer compositions were 3HB (3-hydroxybutyrate), a short-chain-length-PHA, and the medium-chain-length-PHA e.g. 3-hydroxyoctanoate and 3-hydroxydecanoate. Both the phbC and phaC genes were characterized. The phbC enzyme had not been previously detected in a Pseudomonas mendocina species. A 2.15 g/L of an exopolysaccharide, alginate, was also produced with a similar composition to that of other Pseudomonas species.

  19. A role for the regulator PsrA in the polyhydroxyalkanoate metabolism of Pseudomonas putida KT2440.

    Science.gov (United States)

    Fonseca, Pilar; de la Peña, Fernando; Prieto, María Auxiliadora

    2014-11-01

    Pseudomonas putida KT2440 is a Gram-negative bacterium capable of producing medium-chain-length-polyhydroxyalkanoates (mcl-PHA). When fatty acids are used as growth and polymer precursors, the biosynthesis is linked to fatty acid metabolism via ß-oxidation route. In the close-related Pseudomonas aeruginosa, the transcriptional repressor PsrA regulates the ß-oxidation, but little is known about the regulatory system in P. putida. To analyze the effect of the absence of psrA gene on the growth and PHA production in P. putida, a set of different carbon sources were assayed in the wild type strain and in a generated psrA deficient strain (KT40P). The growth rates were in all cases, lower for the mutant. The amount of PHA produced by the mutant strain is lower than the wild type. Moreover, the monomeric composition seems to be different among the strains, as there is enrichment in monomers with shorter carbon length in the mutant strain. To understand the role of the psrA gene on the metabolism of fatty acids, we have determined the expression profile of several genes related to fatty acid metabolism in the wild type and in the mutant strain. The results indicated that PsrA mostly negatively regulate genes related to fatty acid metabolism. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Bioconversion of styrene to poly(hydroxyalkanoate) (PHA) by the new bacterial strain Pseudomonas putida NBUS12.

    Science.gov (United States)

    Tan, Giin-Yu Amy; Chen, Chia-Lung; Ge, Liya; Li, Ling; Tan, Swee Ngin; Wang, Jing-Yuan

    2015-01-01

    Styrene is a toxic pollutant commonly found in waste effluents from plastic processing industries. We herein identified and characterized microorganisms for bioconversion of the organic eco-pollutant styrene into a valuable biopolymer medium-chain-length poly(hydroxyalkanoate) (mcl-PHA). Twelve newly-isolated styrene-degrading Pseudomonads were obtained and partial phaC genes were detected by PCR in these isolates. These isolates assimilated styrene to produce mcl-PHA, forming PHA contents between 0.05±0.00 and 23.10±3.25% cell dry mass (% CDM). The best-performing isolate was identified as Pseudomonas putida NBUS12. A genetic analysis of 16S rDNA and phaZ genes revealed P. putida NBUS12 as a genetically-distinct strain from existing phenotypically-similar bacterial strains. This bacterium achieved a final biomass of 1.28±0.10 g L(-1) and PHA content of 32.49±2.40% CDM. The extracted polymer was mainly comprised of 3-hydroxyhexanoate (C6 ), 3-hydroxyoctanoate (C8 ), 3-hydroxydecanoate (C10 ), 3-hydroxydodecanoate (C12 ), and 3-hydroxytetradecanoate (C14 ) monomers at a ratio of 2:42:1257:17:1. These results collectively suggested that P. putida NBUS12 is a promising candidate for the biotechnological conversion of styrene into mcl-PHA.

  1. Synthesis and Physical Properties of Polyhydroxyalkanoate Polymers with Different Monomer Compositions by Recombinant Pseudomonas putida LS46 Expressing a Novel PHA SYNTHASE (PhaC116 Enzyme

    Directory of Open Access Journals (Sweden)

    Parveen K. Sharma

    2017-03-01

    Full Text Available A recombinant of Pseudomonas putida LS461 (deletion of the phaC1phaZphaC2 genes was constructed by introducing cosmid JC123 carrying a novel phaC116 gene from a metagenomic clone. The resulting strain, P. putida LS46123, was able to synthesize polyhydroxyalkanoate (PHA polymers with novel monomer compositions when cultured on glucose or free fatty acids, and accumulated PHAs from 9.24% to 27.09% of cell dry weight. The PHAs synthesized by P. putida LS46123 contained up to 50 mol % short chain length subunits (3-hydroxybutyrate and 3-hydroxyvalerate, with the remaining monomers consisting of various medium chain length subunits. The PhaC116 protein expressed by P. putida LS46123 had an amino acid sequence similarity of 45% with the PhaC1 protein of the parent strain, P. putida LS46. Predicted 3D structures of the PhaC116 proteins from P. putida LS46123 and P. putida LS46 revealed several differences in the numbers and locations of protein secondary structures. The physical and thermal properties of the novel polymers synthesized by P. putida LS46123 cultured with glucose or free fatty acids differed significantly from those produced by P. putida LS46 grown on the same substrates. PHA polymers with different subunit compositions, and hence different physical and thermal properties, can be tailor-made using novel PHA synthase for specific applications.

  2. Granulator Selection

    Energy Technology Data Exchange (ETDEWEB)

    Gould, T H; Armantrout, G

    1999-08-02

    Following our detailed review of the granulation reports and additional conversations with process and development personnel, we have reached a consensus position regarding granulator selection. At this time, we recommend going forward with implementation of the tumbling granulator approach (GEMCO) based on our assessment of the tested granulation techniques using the established criteria. The basis for this selection is summarized in the following sections, followed by our recommendations for proceeding with implementation of the tumbling granulation approach. All five granulation technologies produced granulated products that can be made into acceptable sintered pucks. A possible exception is the product from the fluidized bed granulator. This material has been more difficult to press into uniform pucks without subsequent cracking of the puck during the sintering cycle for the pucks in this series of tests. This problem may be an artifact of the conditions of the particular granulation demonstration run involved, but earlier results have also been mixed. All granulators made acceptable granulated feed from the standpoint of transfer and press feeding, though the roller compactor and fluidized bed products were dustier than the rest. There was also differentiation among the granulators in the operational areas of (1) potential for process upset, (2) plant implementation and operational complexity, and (3) maintenance concerns. These considerations will be discussed further in the next section. Note that concerns also exist regarding the extension of the granulation processes to powders containing actinides. Only the method that involves tumbling and moisture addition has been tested with uranium, and in that instance, significant differences were found in the granulation behavior of the powders.

  3. Homologous functional expression of cryptic phaG from Pseudomonas oleovorans establishes the transacylase-mediated polyhydroxyalkanoate biosynthetic pathway.

    Science.gov (United States)

    Hoffmann, N; Steinbüchel, A; Rehm, B H

    2000-11-01

    Various pseudomonads are capable of the synthesis of polyhydroxyalkanoate (PHA), composed of medium chain length (MCL) 3-hydroxy fatty acids (C6-C14), when grown on simple carbon sources such as, for example, gluconate or acetate. In Pseudomonas putida, the fatty acid de novo synthesis and PHA synthesis are linked by the transacylase PhaG. Southern hybridization experiments with digoxigenin-labeled phaG(Pp) from P. putida and genomic DNA from various pseudomonads indicate that phaG homologues are present in various other pseudomonads. Although P. oleovorans does not accumulate PHA(MCL) from non-related carbon sources, its genomic DNA reveals a strong hybridization signal. We employed PCR to amplify this phaG homologue. The respective PCR product comprising the coding region of phaG(Po) was cloned into pBBR1MCS-2, resulting in plasmid pBHR84. DNA sequencing revealed that putative PhaG(Po) from P. oleovorans exhibited about 95% amino acid sequence identity to PhaG(Pp) from P. putida. Reverse transcriptase-PCR analysis demonstrated that phaG(Po) was not transcribed even tinder inducing conditions, i.e. in the presence of gluconate as carbon source, whereas induction of phaG(Pp) transcription was obtained in P. putida. When octanoate was used as sole carbon source, only low levels of phaG mRNA were detected in P. putida. Plasmid pBHR84 complemented the phaG-negative mutant PhaG(N)-21 from P. putida. Interestingly, reintroduction of phaG(Po) under lac promoter control into the natural host P. oleovorans established PHA(MCL) synthesis from non-related carbon sources in this bacterium. These data indicated that phaG(Po) in P. oleovorans is not functionally expressed and does not exert its original function.

  4. Synthesis of medium-chain length capsinoids from coconut oil catalyzed by Candida rugosa lipases.

    Science.gov (United States)

    Trbojević Ivić, Jovana; Milosavić, Nenad; Dimitrijević, Aleksandra; Gavrović Jankulović, Marija; Bezbradica, Dejan; Kolarski, Dušan; Veličković, Dušan

    2017-03-01

    A commercial preparation of Candida rugosa lipases (CRL) was tested for the production of capsinoids by esterification of vanillyl alcohol (VA) with free fatty acids (FA) and coconut oil (CO) as acyl donors. Screening of FA chain length indicated that C8-C12 FA (the most common FA found in CO triglycerides) are the best acyl-donors, yielding 80-85% of their specific capsinoids. Hence, when CO, which is rich in these FA, was used as the substrate, a mixture of capsinoids (vanillyl caprylate, vanillyl decanoate and vanillyl laurate) was obtained. The findings presented here suggest that our experimental method can be applied for the enrichment of CO with capsinoids, thus giving it additional health promoting properties. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Microstructure synthesis control of biological polyhydroxyalkanoates with mass spectrometry

    Science.gov (United States)

    Pederson, Erik Norman

    Polyhydroxyalkanoates (PHA's) are a class of biologically produced polymers, or plastic, that is synthesized by various microorganisms. PHA's are made from biorenewable resources and are fully biodegradable and biocompatible, making them an environmentally friendly green polymer. A method of incorporating polymer microstructure into the PHA synthesized in Ralstonia eutropha was developed. These microstructures were synthesized with polyhydroxybutyrate (PHB) and poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) as the polymer domains. To synthesize the PHB V copolymer, the additional presence of valerate was required. To control valerate substrate additions to the bioreactor, an off-gas mass spectrometry (MS) feedback control system was developed. Important process information including the cell physiology, growth kinetics, and product formation kinetics in the bioreactor was obtained with MS and used to control microstructure synthesis. The two polymer microstructures synthesized were core-shell granules and block copolymers. Block copolymers control the structure of the individual polymer chains while core-shell granules control the organization of many polymer chains. Both these microstructures result in properties unattainable by blending the two polymers together. The core-shell structures were synthesized with controlled domain thickness based on a developed model. Different block copolymers compositions were synthesized by varying the switching time of the substrate pulses responsible for block copolymer synthesis. The block copolymers were tested to determine their chemical properties and cast into films to determine the materials properties. These block copolymer films possessed new properties not achieved by copolymers or blends of the two polymers.

  6. In-silico-driven metabolic engineering of Pseudomonas putida for enhanced production of poly-hydroxyalkanoates

    NARCIS (Netherlands)

    Poblete-Castro, I.; Binger, D.; Rodrigues, A.; Becker, J.; Martins Dos Santos, V.A.P.; Wittmann, C.

    2013-01-01

    Here, we present systems metabolic engineering driven by in-silico modeling to tailor Pseudomonas putida for synthesis of medium chain length PHAs on glucose. Using physiological properties of the parent wild type as constraints, elementary flux mode analysis of a large-scale model of the metabolism

  7. Biotechnological Production of Polyhydroxyalkanoates: A Review on Trends and Latest Developments

    Directory of Open Access Journals (Sweden)

    Baljeet Singh Saharan

    2014-01-01

    Full Text Available Polyhydroxyalkanoates (PHA producers have been reported to reside at various ecological niches which are naturally or accidently exposed to high organic matter or growth limited conditions such as dairy wastes, hydrocarbon contaminated sites, pulp and paper mill wastes, agricultural wastes, activated sludges of treatment plants, rhizosphere, and industrial effluents. Few among them also produce extracellular by-products like rhamnolipids, extracellular polymeric substances, and biohydrogen gas. These sorts of microbes are industrially important candidates for the reason that they can use waste materials of different origin as substrate with simultaneous production of valuable bioproducts including PHA. Implementation of integrated system to separate their by-products (intracellular and extracellular can be economical in regard to production. In this review, we have discussed various microorganisms dwelling at different environmental conditions which stimulate them to accumulate carbon as polyhydroxyalkanoates granules and factors influencing its production and composition. A brief aspect on metabolites which are produced concomitantly with PHA has also been discussed. In conclusion, exploring of capabilities like of dual production by microbes and use of wastes as renewable substrate under optimized cultural conditions either in batch or continuous process can cause deduction in present cost of bioplastic production from stored PHA granules.

  8. Biosynthesis of polyhydroxyalkanoates: Current research and ...

    African Journals Online (AJOL)

    Polyhydroxyalkanoates (PHAs) as an attractive biopolymer with a wide range of applications have been extensively studied. Many new strategies have been employed to effectively and economically produce PHAs. This mini-review mainly focuses on the research and development of new PHAs-producing strains, utilization ...

  9. Polyhydroxyalkanoate (PHA) production by Lynisibacillus sp. strain ...

    African Journals Online (AJOL)

    After the period of adaptation in mineral medium from 12 to 24 h, the cell division occurred from 12 to 24 h, and the formation of biopolymers from 36 to 48 h. It was observed that the polymer produced by the isolated UEA-20.171, was P(3HB). Keywords: Polyhydroxyalkanoates, polyhydroxybutyrate, bioplastics, ...

  10. Production of Polyhydroxyalkanoates, a bacterial biodegradable ...

    African Journals Online (AJOL)

    ... production has restricted its applications. The possibility of producing this polymer commercially and at comparable cost has been the main focus in this area. Key Words: Polyhydroxyalkanoates, biodegradable polymer, bioplastic, poly(3-hydroxybutyrate), biosynthesis. African Journal of Biotechnology Vol.3(1) 2004: 18- ...

  11. Production of polyhydroxyalkanoates (PHAs) in transgenic potato

    NARCIS (Netherlands)

    Romano, A.

    2002-01-01

    Polyhydroxyalkanoates (PHAs) represent a large class of microbial polyesters which are widely distributed in prokaryotes. Because of the current environmental concerns related to the use of mineral-oil-based plastics, PHAs gained a considerable interest for

  12. Occurrence, metabolism, metabolic role, and industrial uses of bacterial polyhydroxyalkanoates.

    Science.gov (United States)

    Anderson, A J; Dawes, E A

    1990-12-01

    Polyhydroxyalkanoates (PHAs), of which polyhydroxybutyrate (PHB) is the most abundant, are bacterial carbon and energy reserve materials of widespread occurrence. They are composed of 3-hydroxyacid monomer units and exist as a small number of cytoplasmic granules per cell. The properties of the C4 homopolymer PHB as a biodegradable thermoplastic first attracted industrial attention more than 20 years ago. Copolymers of C4 (3-hydroxybutyrate [3HB]) and C5 (3-hydroxyvalerate [3HV]) monomer units have modified physical properties; e.g., the plastic is less brittle than PHB, whereas PHAs containing C8 to C12 monomers behave as elastomers. This family of materials is the centre of considerable commercial interest, and 3HB-co-3HV copolymers have been marketed by ICI plc as Biopol. The known polymers exist as 2(1) helices with the fiber repeat decreasing from 0.596 nm for PHB to about 0.45 nm for C8 to C10 polymers. Novel copolymers with a backbone of 3HB and 4HB have been obtained. The native granules contain noncrystalline polymer, and water may possibly act as a plasticizer. Although the biosynthesis and regulation of PHB are generally well understood, the corresponding information for the synthesis of long-side-chain PHAs from alkanes, alcohols, and organic acids is still incomplete. The precise mechanisms of action of the polymerizing and depolymerizing enzymes also remain to be established. The structural genes for the three key enzymes of PHB synthesis from acetyl coenzyme A in Alcaligenes eutrophus have been cloned, sequenced, and expressed in Escherichia coli. Polymer molecular weights appear to be species specific. The factors influencing the commercial choice of organism, substrate, and isolation process are discussed. The physiological functions of PHB as a reserve material and in symbiotic nitrogen fixation and its presence in bacterial plasma membranes and putative role in transformability and calcium signaling are also considered.

  13. Engineering bacteria for enhanced polyhydroxyalkanoates (PHA) biosynthesis

    OpenAIRE

    Chen, Guo-Qiang; Jiang, Xiao-Ran

    2017-01-01

    Polyhydroxyalkanoates (PHA) have been produced by some bacteria as bioplastics for many years. Yet their commercialization is still on the way. A few issues are related to the difficulty of PHA commercialization: namely, high cost and instabilities on molecular weights (Mw) and structures, thus instability on thermo-mechanical properties. The high cost is the result of complicated bioprocessing associated with sterilization, low conversion of carbon substrates to PHA products, and slow growth...

  14. Food waste conversion to microbial polyhydroxyalkanoates

    OpenAIRE

    Nielsen, Chad; Rahman, Asif; Rehman, Asad Ur; Walsh, Marie K.; Miller, Charles D.

    2017-01-01

    Summary Polyhydroxyalkanoates (PHAs) are biopolymers with desirable material properties similar to petrochemically derived plastics. PHAs are naturally produced by a wide range of microorganisms as a carbon storage mechanism and can accumulate to significantly high levels. PHAs are an environmentally friendly alternative to their petroleum counterparts because they can be easily degraded, potentially reducing the burden on municipal waste systems. Nevertheless, widespread use of PHAs is not c...

  15. Genome features of Pseudomonas putida LS46, a novel polyhydroxyalkanoate producer and its comparison with other P. putida strains

    Science.gov (United States)

    2014-01-01

    A novel strain of Pseudomonas putida LS46 was isolated from wastewater on the basis of its ability to synthesize medium chain-length polyhydroxyalkanoates (mcl-PHAs). P.putida LS46 was differentiated from other P.putida strains on the basis of cpn60 (UT). The complete genome of P.putida LS46 was sequenced and annotated. Its chromosome is 5,86,2556 bp in size with GC ratio of 61.69. It is encoding 5316 genes, including 7 rRNA genes and 76 tRNA genes. Nucleotide sequence data of the complete P. putida LS46 genome was compared with nine other P. putida strains (KT2440, F1, BIRD-1, S16, ND6, DOT-T1E, UW4, W619 and GB-1) identified either as biocontrol agents or as bioremediation agents and isolated from different geographical region and different environment. BLASTn analysis of whole genome sequences of the ten P. putida strains revealed nucleotide sequence identities of 86.54 to 97.52%. P.putida genome arrangement was LS46 highly similar to P.putida BIRD1 and P.putida ND6 but was markedly different than P.putida DOT-T1E, P.putida UW4 and P.putida W619. Fatty acid biosynthesis (fab), fatty acid degradation (fad) and PHA synthesis genes were highly conserved among biocontrol and bioremediation P.putida strains. Six genes in pha operon of P. putida LS46 showed >98% homology at gene and proteins level. It appears that polyhydroxyalkanoate (PHA) synthesis is an intrinsic property of P. putida and was not affected by its geographic origin. However, all strains, including P. putida LS46, were different from one another on the basis of house keeping genes, and presence of plasmid, prophages, insertion sequence elements and genomic islands. While P. putida LS46 was not selected for plant growth promotion or bioremediation capacity, its genome also encoded genes for root colonization, pyoverdine synthesis, oxidative stress (present in other soil isolates), degradation of aromatic compounds, heavy metal resistance and nicotinic acid degradation, manganese (Mn II) oxidation

  16. Recent Advances and Challenges towards Sustainable Polyhydroxyalkanoate (PHA) Production

    DEFF Research Database (Denmark)

    Kourmentza, Constantina; Plácido, Jersson; Venetsaneas, Nikolaos

    2017-01-01

    Sustainable biofuels, biomaterials, and fine chemicals production is a critical matter that research teams around the globe are focusing on nowadays. Polyhydroxyalkanoates represent one of the biomaterials of the future due to their physicochemical properties, biodegradability, and biocompatibility...... polyhydroxyalkanoate production are presented and discussed, covering key steps of their overall production process by applying pure and mixed culture biotechnology, from raw bioprocess development to downstream processing....

  17. The relation between granule size, granule stickiness, and torque in the high-shear granulation process

    NARCIS (Netherlands)

    Bouwman, A.M.; Henstra, M.J.; Hegge, J.J.M.E.; Zhang, Z.; Ingram, A.; Seville, J.P.K.; Frijlink, H.W.

    2005-01-01

    Purpose. To investigate the background of the observed relationship between measured torque and granule size in high-shear granulation processes. Methods. Torque was measured during the granulation process; the behavior of individual wet granules during compaction was investigated using

  18. Polyhydroxyalkanoate (PHA)/inorganic phase composites for tissue engineering applications.

    Science.gov (United States)

    Misra, Superb K; Valappil, Sabeel P; Roy, Ipsita; Boccaccini, Aldo R

    2006-08-01

    Polyhydroxyalkanoates are emerging as a class of biodegradable polymers for applications in tissue engineering. Members of the polyhydroxyalkanoates family encompass a wide variety of materials, from hard and brittle materials to soft and elastomeric. Over the years, efforts have been made to extend the group of polyhydroxyalkanoates and to investigate their use in numerous biomedical applications, such as sutures, cardiovascular patches, wound dressings, guided tissue repair/regeneration devices, and tissue engineering scaffolds. Along with the development of polyhydroxyalkanoates, researchers have looked into the possibility of designing composites in combination with inorganic phases to further improve the mechanical properties, rate of degradation, and also impart bioactivity. Poly(3-hydroxybutyrate), poly(3-hydroxybutyrate-co-3-hydroxyvalerate), and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) are some of the polymers which have been studied extensively to fabricate composites in combination with hydroxyapatite, bioactive glass, and glass-ceramic fillers or coatings. This paper reviews international research carried out toward development of polyhydroxyalkanoates/inorganic phase composites in terms of systems investigated, microstructures, properties achieved, and applications, with special focus on tissue engineering scaffolds. A comparison between different composite systems developed in the past few years is presented. The paper also addresses the prospect of potential further development of polyhydroxyalkanoates/inorganic phase composites with optimized microstructure and properties for improved tissue engineering scaffolds.

  19. Granulation of fine powder

    Science.gov (United States)

    Chen, Ching-Fong

    2016-08-09

    A mixture of fine powder including thorium oxide was converted to granulated powder by forming a first-green-body and heat treating the first-green-body at a high temperature to strengthen the first-green-body followed by granulation by crushing or milling the heat-treated first-green-body. The granulated powder was achieved by screening through a combination of sieves to achieve the desired granule size distribution. The granulated powder relies on the thermal bonding to maintain its shape and structure. The granulated powder contains no organic binder and can be stored in a radioactive or other extreme environment. The granulated powder was pressed and sintered to form a dense compact with a higher density and more uniform pore size distribution.

  20. Isolation and recovery of microbial polyhydroxyalkanoates

    Directory of Open Access Journals (Sweden)

    2011-07-01

    Full Text Available The deleterious environmental impacts caused by plastic wastes have attracted worldwide concern. The biobased and biodegradable polyhydroxyalkanoate (PHA appears to be one of the potential candidates to replace some conventional plastics. However, high production cost of PHAs has limited their market penetration. The major cost absorbing factors are the upstream fermentation processes and the downstream PHA recovery technologies. The latter significantly affects the overall process economics. Various recovery technologies have been proposed and studied in small scales in the laboratory as well as in industrial scales. These include solvent extraction, chemical digestion, enzymatic treatment and mechanical disruption, supercritical fluid disruption, flotation techniques, use of gamma irradiation and aqueous two-phase system. This paper reviews all the recovery methods known to date and compares their efficiency and the quality of the resulting PHA. Some of the large-scale production of PHA and the strategies employed to reduce the production cost are also discussed.

  1. Bacillus subtilis as potential producer for polyhydroxyalkanoates

    Directory of Open Access Journals (Sweden)

    Patel Sanjay KS

    2009-07-01

    Full Text Available Abstract Polyhydroxyalkanoates (PHAs are biodegradable polymers produced by microbes to overcome environmental stress. Commercial production of PHAs is limited by the high cost of production compared to conventional plastics. Another hindrance is the brittle nature and low strength of polyhydroxybutyrate (PHB, the most widely studied PHA. The needs are to produce PHAs, which have better elastomeric properties suitable for biomedical applications, preferably from inexpensive renewable sources to reduce cost. Certain unique properties of Bacillus subtilis such as lack of the toxic lipo-polysaccharides, expression of self-lysing genes on completion of PHA biosynthetic process – for easy and timely recovery, usage of biowastes as feed enable it to compete as potential candidate for commercial production of PHA.

  2. Light scattering on PHA granules protects bacterial cells against the harmful effects of UV radiation.

    Science.gov (United States)

    Slaninova, Eva; Sedlacek, Petr; Mravec, Filip; Mullerova, Lucie; Samek, Ota; Koller, Martin; Hesko, Ondrej; Kucera, Dan; Marova, Ivana; Obruca, Stanislav

    2018-02-01

    Numerous prokaryotes accumulate polyhydroxyalkanoates (PHA) in the form of intracellular granules. The primary function of PHA is the storage of carbon and energy. Nevertheless, there are numerous reports that the presence of PHA granules in microbial cells enhances their stress resistance and fitness when exposed to various stress factors. In this work, we studied the protective mechanism of PHA granules against UV irradiation employing Cupriavidus necator as a model bacterial strain. The PHA-accumulating wild type strain showed substantially higher UV radiation resistance than the PHA non-accumulating mutant. Furthermore, the differences in UV-Vis radiation interactions with both cell types were studied using various spectroscopic approaches (turbidimetry, absorption spectroscopy, and nephelometry). Our results clearly demonstrate that intracellular PHA granules efficiently scatter UV radiation, which provides a substantial UV-protective effect for bacterial cells and, moreover, decreases the intracellular level of reactive oxygen species in UV-challenged cells. The protective properties of the PHA granules are enhanced by the fact that granules specifically bind to DNA, which in turn provides shield-like protection of DNA as the most UV-sensitive molecule. To conclude, the UV-protective action of PHA granules adds considerable value to their primary storage function, which can be beneficial in numerous environments.

  3. [Bio-modification of polyhydroxyalkanoates and its biocompatibility with chondrocytes].

    Science.gov (United States)

    Gao, Tianxi; Chang, Huimin; Fan, Minjie; Lu, Xiaoyun; Wang, Zhenghui; Zhang, Xianghong; Jing, Xiaohong; Shi, Yanxia; Li, Zhihui

    2014-08-01

    To study the hydrophilicity and the cell biocompatibility of the poly(3-hydroxybutyrate-co- 3-hydroxyvalerate) (PHBV) and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) coated with a fusion protein polyhydroxyalkanoates granule binding protein (PhaP) fused with Arg-Gly-Asp (RGD) peptide (PhaP-RGD). PHBV and PHBHHx films were fabricated by solvent evaporation. Scanning electronic microscope (SEM) was used to study the morphology of the films. PhaP-RGD fusion proteins were expressed and purified by the technology of protein engineering; PHBV and PHBHHx films were immersed in the PhaP-RGD with an amount of 3.5 mg/mL protein/per sample respectively. The hydrophilicity of the surface were detected by the contact angle measurements. Septal cartilage cells obtained from human septal cartilage were cultured in vitro. The 2nd passage chondrocytes were incubated on PHBV unmodified with PhaP-RGD in group A1, PHBV modified with PhaP-RGD in group A2, PHBHHx unmodified with PhaP-RGD in group Bl, PHBHHx modified with PhaP-RGD in group B2, and on the cell culture plates in group C. After cultured for 3 days, the proliferation of cells was detected by the DAPI staining; the proliferation viability of cells was detected by the MTT assay after cultured for 3 and 7 days; after cultured for 7 days, the adhesion and morphology of the cells on the surface of the biomaterial films were observed by SEM and the matrix of the cells was detected through the toluidine blue staining. SEM observation showed that PHBV and PHBHHx films had porous structures. The contact angle of the surface of the PHBV and PHBHHx films modified with PhaP-RGD fusion proteins were significantly reduced when compared with the films unmodified with PhaP-RGD fusion proteins (P films could grow in all groups. After 3 days of cultivation in vitro, the cell proliferation and viability of group B2 were the strongest among all groups (P films of PHBHHx modified with PhaP-RGD fusion protein can promote its

  4. Isolation and screening of polyhydroxyalkanoates producing bacteria from pulp, paper, and cardboard industry wastes.

    Science.gov (United States)

    Bhuwal, Anish Kumari; Singh, Gulab; Aggarwal, Neeraj Kumar; Goyal, Varsha; Yadav, Anita

    2013-01-01

    Background. Polyhydroxyalkanoates (PHAs) are storage materials that accumulate by various bacteria as energy and carbon reserve materials. They are biodegradable, environmentally friendly, and also biocompatible bioplastics. Unlike petrochemical-based plastics that take several decades to fully degrade, PHAs can be completely degraded within a year by variety of microorganisms into CO2 and water. In the present study, we aim to utilize pulp, paper, and cardboard industry sludge and waste water for the isolation and screening of polyhydroxyalkanoates (PHAs) accumulating bacteria and production of cost-effective PHB using cardboard industry waste water. Results. A total of 42 isolates showed black-blue coloration when stained with Sudan black B, a preliminary screening agent for lipophilic compounds, and a total of 15 isolates showed positive result with Nile blue A staining, a more specific dye for PHA granules. The isolates NAP11 and NAC1 showed maximum PHA production 79.27% and 77.63% with polymer concentration of 5.236 g/L and 4.042 g/L with cardboard industry waste water. Both of the selected isolates, NAP11 and NAC1, were classified up to genus level by studying their morphological and biochemical characteristics and were found to be Enterococcus sp., Brevundimonas sp. and, respectively. Conclusion. The isolates Enterococcus sp. NAP11 and Brevundimonas sp. NAC1 can be considered as good candidates for industrial production of PHB from cardboard industry waste water. We are reporting for the first time the use of cardboard industry waste water as a cultivation medium for the PHB production.

  5. Isolation and Screening of Polyhydroxyalkanoates Producing Bacteria from Pulp, Paper, and Cardboard Industry Wastes

    Directory of Open Access Journals (Sweden)

    Anish Kumari Bhuwal

    2013-01-01

    Full Text Available Background. Polyhydroxyalkanoates (PHAs are storage materials that accumulate by various bacteria as energy and carbon reserve materials. They are biodegradable, environmentally friendly, and also biocompatible bioplastics. Unlike petrochemical-based plastics that take several decades to fully degrade, PHAs can be completely degraded within a year by variety of microorganisms into CO2 and water. In the present study, we aim to utilize pulp, paper, and cardboard industry sludge and waste water for the isolation and screening of polyhydroxyalkanoates (PHAs accumulating bacteria and production of cost-effective PHB using cardboard industry waste water. Results. A total of 42 isolates showed black-blue coloration when stained with Sudan black B, a preliminary screening agent for lipophilic compounds, and a total of 15 isolates showed positive result with Nile blue A staining, a more specific dye for PHA granules. The isolates NAP11 and NAC1 showed maximum PHA production 79.27% and 77.63% with polymer concentration of 5.236 g/L and 4.042 g/L with cardboard industry waste water. Both of the selected isolates, NAP11 and NAC1, were classified up to genus level by studying their morphological and biochemical characteristics and were found to be Enterococcus sp., Brevundimonas sp. and, respectively. Conclusion. The isolates Enterococcus sp. NAP11 and Brevundimonas sp. NAC1 can be considered as good candidates for industrial production of PHB from cardboard industry waste water. We are reporting for the first time the use of cardboard industry waste water as a cultivation medium for the PHB production.

  6. Anaerobic sludge granulation

    NARCIS (Netherlands)

    Hulshoff Pol, L.W.; Castro Lopes, de S.I.; Lettinga, G.; Lens, P.N.L.

    2004-01-01

    This paper reviews different theories on anaerobic sludge granulation in UASB-reactors that have been proposed during the past two decades
    This paper reviews different theories on anaerobic sludge granulation in UASB-reactors that have been proposed during the past two decades. The initial

  7. Engineering bacteria for enhanced polyhydroxyalkanoates (PHA biosynthesis

    Directory of Open Access Journals (Sweden)

    Guo-Qiang Chen

    2017-09-01

    Full Text Available Polyhydroxyalkanoates (PHA have been produced by some bacteria as bioplastics for many years. Yet their commercialization is still on the way. A few issues are related to the difficulty of PHA commercialization: namely, high cost and instabilities on molecular weights (Mw and structures, thus instability on thermo-mechanical properties. The high cost is the result of complicated bioprocessing associated with sterilization, low conversion of carbon substrates to PHA products, and slow growth of microorganisms as well as difficulty of downstream separation. Future engineering on PHA producing microorganisms should be focused on contamination resistant bacteria especially extremophiles, developments of engineering approaches for the extremophiles, increase on carbon substrates to PHA conversion and controlling Mw of PHA. The concept proof studies could still be conducted on E. coli or Pseudomonas spp. that are easily used for molecular manipulations. In this review, we will use E. coli and halophiles as examples to show how to engineer bacteria for enhanced PHA biosynthesis and for increasing PHA competitiveness.

  8. Engineering bacteria for enhanced polyhydroxyalkanoates (PHA) biosynthesis.

    Science.gov (United States)

    Chen, Guo-Qiang; Jiang, Xiao-Ran

    2017-09-01

    Polyhydroxyalkanoates (PHA) have been produced by some bacteria as bioplastics for many years. Yet their commercialization is still on the way. A few issues are related to the difficulty of PHA commercialization: namely, high cost and instabilities on molecular weights (Mw) and structures, thus instability on thermo-mechanical properties. The high cost is the result of complicated bioprocessing associated with sterilization, low conversion of carbon substrates to PHA products, and slow growth of microorganisms as well as difficulty of downstream separation. Future engineering on PHA producing microorganisms should be focused on contamination resistant bacteria especially extremophiles, developments of engineering approaches for the extremophiles, increase on carbon substrates to PHA conversion and controlling Mw of PHA. The concept proof studies could still be conducted on E. coli or Pseudomonas spp. that are easily used for molecular manipulations. In this review, we will use E. coli and halophiles as examples to show how to engineer bacteria for enhanced PHA biosynthesis and for increasing PHA competitiveness.

  9. Food waste conversion to microbial polyhydroxyalkanoates.

    Science.gov (United States)

    Nielsen, Chad; Rahman, Asif; Rehman, Asad Ur; Walsh, Marie K; Miller, Charles D

    2017-11-01

    Polyhydroxyalkanoates (PHAs) are biopolymers with desirable material properties similar to petrochemically derived plastics. PHAs are naturally produced by a wide range of microorganisms as a carbon storage mechanism and can accumulate to significantly high levels. PHAs are an environmentally friendly alternative to their petroleum counterparts because they can be easily degraded, potentially reducing the burden on municipal waste systems. Nevertheless, widespread use of PHAs is not currently realistic due to a variety of factors. One of the major constraints of large-scale PHA production is the cost of carbon substrate for PHA-producing microbes. The cost of production could potentially be reduced with the use of waste carbon from food-related processes. Food wastage is a global issue and therefore harbours immense potential to create valuable bioproducts. This article's main focus is to examine the state of the art of converting food-derived waste into carbon substrates for microbial metabolism and subsequent conversion into PHAs. © 2017 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

  10. Recent Advances and Challenges towards Sustainable Polyhydroxyalkanoate (PHA) Production

    Science.gov (United States)

    Kourmentza, Constantina; Plácido, Jersson; Venetsaneas, Nikolaos; Burniol-Figols, Anna; Varrone, Cristiano; Gavala, Hariklia N.; Reis, Maria A. M.

    2017-01-01

    Sustainable biofuels, biomaterials, and fine chemicals production is a critical matter that research teams around the globe are focusing on nowadays. Polyhydroxyalkanoates represent one of the biomaterials of the future due to their physicochemical properties, biodegradability, and biocompatibility. Designing efficient and economic bioprocesses, combined with the respective social and environmental benefits, has brought together scientists from different backgrounds highlighting the multidisciplinary character of such a venture. In the current review, challenges and opportunities regarding polyhydroxyalkanoate production are presented and discussed, covering key steps of their overall production process by applying pure and mixed culture biotechnology, from raw bioprocess development to downstream processing. PMID:28952534

  11. Recent Advances and Challenges towards Sustainable Polyhydroxyalkanoate (PHA) Production.

    Science.gov (United States)

    Kourmentza, Constantina; Plácido, Jersson; Venetsaneas, Nikolaos; Burniol-Figols, Anna; Varrone, Cristiano; Gavala, Hariklia N; Reis, Maria A M

    2017-06-11

    Sustainable biofuels, biomaterials, and fine chemicals production is a critical matter that research teams around the globe are focusing on nowadays. Polyhydroxyalkanoates represent one of the biomaterials of the future due to their physicochemical properties, biodegradability, and biocompatibility. Designing efficient and economic bioprocesses, combined with the respective social and environmental benefits, has brought together scientists from different backgrounds highlighting the multidisciplinary character of such a venture. In the current review, challenges and opportunities regarding polyhydroxyalkanoate production are presented and discussed, covering key steps of their overall production process by applying pure and mixed culture biotechnology, from raw bioprocess development to downstream processing.

  12. Accumulation of PHA granules in Cupriavidus necator as seen by confocal fluorescence microscopy

    Czech Academy of Sciences Publication Activity Database

    Mravec, F.; Obruča, S.; Krzyžánek, Vladislav; Sedláček, P.; Hrubanová, Kamila; Samek, Ota; Kučera, D.; Benešová, P.; Nebesářová, Jana

    2016-01-01

    Roč. 363, č. 10 (2016), fnw094:1-7 ISSN 0378-1097 R&D Projects: GA ČR(CZ) GA15-20645S Grant - others:GA MŠk(CZ) LO1211 Institutional support: RVO:68081731 ; RVO:60077344 Keywords : polyhydroxyalkanoates * intracellular granules * confocal fluorescence microscopy * bacterial cell diameters Subject RIV: BH - Optics, Masers, Lasers; BH - Optics, Masers, Lasers (BC-A) Impact factor: 1.765, year: 2016 http://femsle.oxfordjournals.org/content/363/10/fnw094

  13. Effect of the granulation process on nitrofurantoin granule characteristics.

    Science.gov (United States)

    Arnaud, P; Brossard, D; Chaumeil, J C

    1998-01-01

    We studied four granulation methods on the same quantitative and qualitative formula: wet massing by forced agglomeration (Lödige) and free agglomeration (Glatt); and dry massing by slugging and roller compaction technique. Three different particle sizes of nitrofurantoin (bioinequivalent drug) were used. The nitrofurantoin particle size has a very low influence on the physical characteristics of the granules. The granulating process influenced the binding of the particles. Granules processed using the wet granulating method were harder than those made by dry process. Lödige granules were more bonded than Glatt granules. Granules prepared by dry massing presented broken particles. The surface area and the porosity of Glatt granules were the most important parameters. Dissolution studies must be effected to make a correlation between the physical results and the dissolution rates. It is necessary to effect a new validation and a comparison of the results when a new granulating apparatus is used.

  14. Genetic determination of polyhydroxyalkanoate metabolism in Rhodobacter capsulatus SB1003

    Czech Academy of Sciences Publication Activity Database

    Ulbrich, P.; Strnad, Hynek; Hejkalová, V.; Pačes, Jan

    2002-01-01

    Roč. 48, č. 4 (2002), s. 157-159 ISSN 0015-5500 R&D Projects: GA MŠk LN00A079 Institutional research plan: CEZ:AV0Z5052915 Keywords : bacterial genomes * gene organization * polyhydroxyalkanoates Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 0.615, year: 2002

  15. Metabolic modeling of mixed substrate uptake for polyhydroxyalkanoate (PHA) production

    NARCIS (Netherlands)

    Jiang, Y.; Hebly, M.; Kleerebezem, R.; Muyzer, G.; van Loosdrecht, M.C.M.

    2011-01-01

    Polyhydroxyalkanoate (PHA) production by mixed microbial communities can be established in a two-stage process, consisting of a microbial enrichment step and a PHA accumulation step. In this study, a mathematical model was constructed for evaluating the influence of the carbon substrate composition

  16. Immobilization of Active Bacteriophages on Polyhydroxyalkanoate Surfaces.

    Science.gov (United States)

    Wang, Chanchan; Sauvageau, Dominic; Elias, Anastasia

    2016-01-20

    A rapid, efficient technique for the attachment of bacteriophages (phages) onto polyhydroxyalkanoate (PHA) surfaces has been developed and compared to three reported methods for phage immobilization. Polymer surfaces were modified to facilitate phage attachment using (1) plasma treatment alone, (2) plasma treatment followed by activation by 1-ethyl-3-(3-(dimethylamino)propyl)carbodiimide hydrochloride (EDC) and N-hydroxysulfosuccinimide (sulfo-NHS), (3) plasma-initiated acrylic acid grafting, or (4) plasma-initiated acrylic acid grafting with activation by EDC and sulfo-NHS. The impact of each method on the surface chemistry of PHA was investigated using contact angle analysis and X-ray photoelectron spectroscopy. Each of the four treatments was shown to result in both increased hydrophilicity and in the modification of the surface functional groups. Modified surfaces were immersed in suspensions of phage T4 for immobilization. The highest level of phage binding was observed for the surfaces modified by plasma treatment alone. The change in chemical bond states observed for surfaces that underwent plasma treatment is suspected to be the cause of the increased binding of active phages. Plasma-treated surfaces were further analyzed through phage-staining and fluorescence microscopy to assess the surface density of immobilized phages and their capacity to capture hosts. The infective capability of attached phages was confirmed by exposing the phage-immobilized surfaces to the host bacteria Escherichia coli in both plaque and infection dynamic assays. Plasma-treated surfaces with immobilized phages displayed higher infectivity than surfaces treated with other methods; in fact, the equivalent initial multiplicity of infection was 2 orders of magnitude greater than with other methods. Control samples - prepared by immersing polymer surfaces in phage suspensions (without prior plasma treatment) - did not show any bacterial growth inhibition, suggesting they did not bind

  17. Mining the granule proteome

    DEFF Research Database (Denmark)

    Albrethsen, Jakob; Goetze, Jens P; Johnsen, Anders H

    2015-01-01

    Proteomics of secretory granules is an emerging strategy for identifying secreted proteins, including potentially novel candidate biomarkers and peptide hormones. In addition, proteomics can provide information about the abundance, localization and structure (post-translational modification) of g...

  18. Isolation of RNP granules

    DEFF Research Database (Denmark)

    Jønson, Lars; Nielsen, Finn Cilius; Christiansen, Jan

    2011-01-01

    The post-transcriptional operon provides a means of synexpression of mRNAs encoding interrelated proteins. The coordination of gene expression may be achieved by a trans-acting RNA-binding protein attaching to similar cis-elements in different, yet functionally clustered, mRNAs. The RNP granule can...... be regarded as a supramolecular assembly of RNA and protein, probably representing several overlapping post-transcriptional operons. The present protocol describes how RNP granules may be isolated by the transgenic expression of a 3X FLAG version of an RNA-binding protein under tetracycline control via...

  19. Experimental study of urea granulation

    International Nuclear Information System (INIS)

    Irshad, U.; Sharif, M.N.; Rabbani, F.; Rauf, A.; Saleem, M.

    2009-01-01

    Urea is a nitrogenous fertilizer available in two commercial forms, prills and granules, in Pakistan. Prills are more common in Pakistan, however, it has some problems associated with it. Those are moisture, biuret contents of urea prills, prill size, hardness of prills, caking of prills and urea dust emission. Due to these problems urea granulation is favoured over prilling. Urea granulation is studied on laboratory scale using pan granulator and effect of different parameters like binders (water and urea solution), quantity of binders, rpm of pan granulator, time of granulation and angle of inclination on granulation yield is studied. Water and urea solutions of different concentrations are used and results reveal that concentration of urea solution is proportional to rate of granulation. A threshold quantity of binder is required for optimum granulation yield. RPM of pan is inversely proportional to rate of granulation. Granulation yield is also proportional to time of granulation however it becomes critical at a certain point. Angle of inclination of pan has no significant effects on granulation yield. (author)

  20. Granulation of increasingly hydrophobic formulations using a twin screw granulator.

    Science.gov (United States)

    Yu, Shen; Reynolds, Gavin K; Huang, Zhenyu; de Matas, Marcel; Salman, Agba D

    2014-11-20

    The application of twin screw granulation in the pharmaceutical industry has generated increasing interest due to its suitability for continuous processing. However, an understanding of the impact of formulation properties such as hydrophobicity on intermediate and finished product quality has not yet been established. Hence, the current work investigated the granulation behaviour of three formulations containing increasing amounts of hydrophobic components using a Consigma™-1 twin screw granulator. Process conditions including powder feed rate, liquid to solid ratio, granulation liquid composition and screw configuration were also evaluated. The size of the wet granules was measured in order to enable exploration of granulation behaviour in isolation without confounding effects from downstream processes such as drying. The experimental observations indicated that the granulation process was not sensitive to the powder feed rate. The hydrophobicity led to heterogeneous liquid distribution and hence a relatively large proportion of un-wetted particles. Increasing numbers of kneading elements led to high shear and prolonged residence time, which acted to enhance the distribution of liquid and feeding materials. The bimodal size distributions considered to be characteristic of twin screw granulation were primarily ascribed to the breakage of relatively large granules by the kneading elements. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Biosynthesis and composition of bacterial poly(hydroxyalkanoates).

    Science.gov (United States)

    Anderson, A J; Haywood, G W; Dawes, E A

    1990-04-01

    It is well established that Alcaligenes eutrophus can accumulate a copolymer containing 3-hydroxybutyrate and 3-hydroxyvalerate, but longer 3-hydroxyacid monomers have not been reported to occur in this organism. The properties of the enzymes of poly(hydroxyalkanoate) (PHA) biosynthesis are discussed and it is proposed that the substrate specificity of the polymerizing enzyme restricts the range of monomer units incorporated into PHA. Various other bacteria produce similar copolymers from propionic acid and/or valeric acid. A number of Pseudomonas species accumulate PHAs containing longer-chain monomer units from linear alkanoic acids, alkanes and alcohols.

  2. Optimization of polyhydroxyalkanoates fermentations with on-line capacitance measurement.

    Science.gov (United States)

    Li, Lan; Wang, Ze-Jian; Chen, Xue-Jun; Chu, Ju; Zhuang, Ying-Ping; Zhang, Si-Liang

    2014-03-01

    The aim of this work was to provide an effective methodology for optimization of the polyhydroxyalkanoates (PHAs) fermentation with Ralstonia eutropha by the on-line capacitance measurement. The present study found the capacitance values could reflect variations of microbial morphology and viability. Furthermore, oxygen uptake rate, specific oxygen uptake rate and specific growth rate were measured in real-time and compared with the capacitance value. In addition, a fed-batch control strategy based on the on-line capacitance measurement was proposed to improve the PHAs production by 22%. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Roll compaction/dry granulation: comparison between roll mill and oscillating granulator in dry granulation.

    Science.gov (United States)

    Sakwanichol, Jarunee; Puttipipatkhachorn, Satit; Ingenerf, Gernot; Kleinebudde, Peter

    2012-01-01

    Different experimental factorial designs were employed to evaluate granule properties obtained from oscillating granulator and roll mill. Four oscillating-granulator parameters were varied, i.e. rotor speed, oscillating angle, aperture of mesh screen and rotor type. Six roll-mill parameters that were throughput, speed ratio in both first and second stages, gap between roll pair in both stages and roll-surface texture were also investigated. Afterwards, the granule properties obtained from two milling types with similar median particle size were compared. All milling parameters in both milling types affected significantly the median particle size, size distribution and amount of fine particles (P rotor types of oscillating granulator on fines. Only three milling parameters influenced significantly the flowability (P < 0.05). These were the throughput and the gap size in the first stage of roll mill and the sieve size of oscillating granulator. In comparison between milling types, the differences of granule properties were not practically relevant. However, the roll mill had much higher capacity than the oscillating granulator about seven times, resulting in improving energy savings per unit of product. Consequently, the roll mill can be applied instead of oscillating granulator for roll compaction/dry granulation technique.

  4. Induction of apoptosis by the medium-chain length fatty acid lauric acid in colon cancer cells due to induction of oxidative stress.

    Science.gov (United States)

    Fauser, J K; Matthews, G M; Cummins, A G; Howarth, G S

    2013-01-01

    Fatty acids are classified as short-chain (SCFA), medium-chain (MCFA) or long-chain and hold promise as adjunctive chemotherapeutic agents for the treatment of colorectal cancer. The antineoplastic potential of MCFA remains underexplored; accordingly, we compared the MCFA lauric acid (C12:0) to the SCFA butyrate (C4:0) in terms of their capacity to induce apoptosis, modify glutathione (GSH) levels, generate reactive oxygen species (ROS), and modify phases of the cell cycle in Caco-2 and IEC-6 intestinal cell lines. Caco-2 and IEC-6 cells were treated with lauric acid, butyrate, or vehicle controls. Apoptosis, ROS, and cell cycle analysis were determined by flow cytometry. GSH availability was assessed by enzymology. Lauric acid induced apoptosis in Caco-2 (p lauric acid reduced GSH availability and generated ROS compared to butyrate (p Lauric acid reduced Caco-2 and IEC-6 cells in G0/G1and arrested cells in the S and G2/M phases. Lauric acid induced apoptosis in IEC-6 cells compared to butyrate (p lauric acid induced high levels of ROS compared to butyrate. Compared to butyrate, lauric acid displayed preferential antineoplastic properties, including induction of apoptosis in a CRC cell line.

  5. Improved production of medium-chain-length Polyhydroxyalkanotes in glucose-based fed-batch cultivations of metabolically engineered Pseudomonas putida strains

    NARCIS (Netherlands)

    Poblete-Castro, I.; Rodriguez, A.L.; Lam, M.C.; Kessler, W.

    2014-01-01

    One of the major challenges in metabolic engineering for enhanced synthesis of value-added chemicals is to design and develop new strains which can be translated into well-controlled fermentation processes using bioreactors. The aim of this study was to assess the influence of various fed-batch

  6. Spray granulation for drug formulation.

    Science.gov (United States)

    Loh, Zhi Hui; Er, Dawn Z L; Chan, Lai Wah; Liew, Celine V; Heng, Paul W S

    2011-12-01

    Granulation is a key unit process in the production of pharmaceutical solid dosage forms and involves the agglomeration of fine particles with the aid of a binding agent. Fluidized bed granulation, a classic example of spray granulation, is a technique of particle agglomeration brought about by the spray addition of the binding liquid onto a stationary bed of powder particles that is transformed to a fluid-like state by the passage of air through it. The basic working principles, equipment set-up, advantages and challenges of fluidized bed granulation are introduced in this review. This is followed by an overview of the formulation and process-related variables affecting granulation performance. Technological advances, particularly in the application of process analytical tools, in the field of fluidized bed granulation research are also discussed. Fluidized bed granulation is a popular technique for pharmaceutical production, as it is a highly economical and efficient one-pot process. The research and development of process analytical technologies (PAT) has allowed greater process understanding and control to be achieved, even for the lesser known fluidized bed techniques, such as bottom spray and fluidized hot melt granulation. In view of its consistent mixing, as well as continuous and concurrent wetting and drying occurring throughout processing, fluidized bed granulation shows great potential for continuous production although more research is required to fully implement, validate and integrate the PAT tools in a production line.

  7. A Comparison of Granules Produced by High-Shear and Fluidized-Bed Granulation Methods

    OpenAIRE

    Morin, Garett; Briens, Lauren

    2014-01-01

    Placebo granules were manufactured by both wet high-shear and fluidized-bed techniques. The granules were compared based on size, shape, surface morphology, and a variety of different flowability measurements. This comparison showed that granule formation and growth were different, with induction growth for high-shear granulation and steady growth for fluidized-bed granulation. Final granules from high-shear granulation were more spherical and dense compared with the irregular granules from f...

  8. Correlation between loose density and compactibility of granules prepared by various granulation methods.

    Science.gov (United States)

    Murakami, H; Yoneyama, T; Nakajima, K; Kobayashi, M

    2001-03-23

    The objectives of this study were to prepare the lactose granules by various granulation methods using polyethylene glycol 6000 (PEG 6000) as a binder and to evaluate the effects of granulation methods on the compressibility and compactibility of granules in tabletting. Lactose was granulated by seven granulation methods -- four wet granulations including wet massing granulation, wet high-speed mixer granulation, wet fluidized bed granulation and wet tumbling fluidized bed granulation; and three melt granulations including melt high-speed mixer granulation, melt fluidized bed granulation and melt tumbling fluidized bed granulation. The loose density, angle of repose, granule size distribution, mean diameter of granules, and the tensile strength and porosity of tablets were evaluated. The compactibilities of granules were varied by the granulation methods. However, the difference in compactibility of granules could not be explained due to the difference in compressibility, since there was no difference in Heckel plots due to granulation methods. Among their granule properties, the loose density of granules seemed to have a correlation with the tablet strength regardless of the granulation methods.

  9. Granulation techniques and technologies: recent progresses.

    Science.gov (United States)

    Shanmugam, Srinivasan

    2015-01-01

    Granulation, the process of particle enlargement by agglomeration technique, is one of the most significant unit operations in the production of pharmaceutical dosage forms, mostly tablets and capsules. Granulation process transforms fine powders into free-flowing, dust-free granules that are easy to compress. Nevertheless, granulation poses numerous challenges due to high quality requirement of the formed granules in terms of content uniformity and physicochemical properties such as granule size, bulk density, porosity, hardness, moisture, compressibility, etc. together with physical and chemical stability of the drug. Granulation process can be divided into two types: wet granulation that utilize a liquid in the process and dry granulation that requires no liquid. The type of process selection requires thorough knowledge of physicochemical properties of the drug, excipients, required flow and release properties, to name a few. Among currently available technologies, spray drying, roller compaction, high shear mixing, and fluid bed granulation are worth of note. Like any other scientific field, pharmaceutical granulation technology also continues to change, and arrival of novel and innovative technologies are inevitable. This review focuses on the recent progress in the granulation techniques and technologies such as pneumatic dry granulation, reverse wet granulation, steam granulation, moisture-activated dry granulation, thermal adhesion granulation, freeze granulation, and foamed binder or foam granulation. This review gives an overview of these with a short description about each development along with its significance and limitations.

  10. Process optimization for polyhydroxyalkanoate (PHA) production from waste via microbial enrichment cultures

    NARCIS (Netherlands)

    Korkakaki, E.

    2017-01-01

    Polyhydroxyalkanoates (PHA) are compounds naturally produced by microorganisms, with many industrial applications, either as bioplastics or as precursors for production of chemicals. Until now, industrial PHA production was conducted with pure strains of bacteria fed with well-defined feedstocks,

  11. Potential of Diverse Prokaryotic Organisms for Glycerol-based Polyhydroxyalkanoate Production

    Directory of Open Access Journals (Sweden)

    Martin Koller

    2015-06-01

    Full Text Available The potential and performance of various Gram-negative, Gram-positive and archaeal wild type microorganisms, and bacterial mixed cultures, as well as the application of genetically engineered strains as whole-cell biocatalysts for glycerol-based polyhydroxyalkanoate production are analyzed and assessed. This encompasses the comparison of growth and polyhydroxyalkanoate accumulation kinetics, thermo-mechanical properties of isolated glycerol-based polyhydroxyalkanoate of different composition on the monomeric level, and the presentation of mathematical models developed to describe glycerol-based polyhydroxyalkanoate production processes. For all these aspects, the article provides a detailed compilation of the contemporary state of knowledge, and gives an outlook to expected future developments.

  12. Accumulation of a Polyhydroxyalkanoate Containing Primarily 3-Hydroxydecanoate from Simple Carbohydrate Substrates by Pseudomonas sp. Strain NCIMB 40135

    OpenAIRE

    Haywood, Geoffrey W.; Anderson, Alistair J.; Ewing, David F.; Dawes, Edwin A.

    1990-01-01

    A number of Pseudomonas species have been identified which accumulate a polyhydroxyalkanoate containing mainly 3-hydroxydecanoate monomers from sodium gluconate as the sole carbon source. One of these, Pseudomonas sp. strain NCIMB 40135, was further investigated and shown to accumulate such a polyhydroxyalkanoate from a wide range of carbon sources (C2 to C6); however, when supplied with octanoic acid it produced a polyhydroxyalkanoate containing mainly 3-hydroxyoctanoate monomers. Polymer sy...

  13. A comparison of granules produced by high-shear and fluidized-bed granulation methods.

    Science.gov (United States)

    Morin, Garett; Briens, Lauren

    2014-08-01

    Placebo granules were manufactured by both wet high-shear and fluidized-bed techniques. The granules were compared based on size, shape, surface morphology, and a variety of different flowability measurements. This comparison showed that granule formation and growth were different, with induction growth for high-shear granulation and steady growth for fluidized-bed granulation. Final granules from high-shear granulation were more spherical and dense compared with the irregular granules from fluidized-bed granulation. The high-shear granules demonstrated better overall flow properties.

  14. Collages of granulation pictures

    International Nuclear Information System (INIS)

    Dunn, R.B.; November, L.J.

    1985-01-01

    This paper describes two small-area selection schemes that the authors have applied to CCD observations of solar granulation. The first scheme, which the authors call the ''mosaic,'' divides the 128 x 128 array into 64 subarrays each containing 16 x 16 pixels. On each picture in the burst the RMS contrast of the fine structure is measured in each subarray and compared to the corresponding value in a table that contains the highest previous RMS values. The second scheme, which the authors call a ''collage,'' is similar except the RMS value is calculated smoothly within a sliding Gaussian window over the entire scene and the value of an individual pixel is gated into the final collage whenever the RMS contrast at that pixel location exceeds that of all previous frames taken during the burst

  15. Ecology and characterization of polyhydroxyalkanoate-producing microorganisms on and in plants.

    Science.gov (United States)

    Gasser, Ilona; Müller, Henry; Berg, Gabriele

    2009-10-01

    Polyhydroxyalkanoates are energy reserve polymers produced by bacteria to survive periods of starvation in natural habitats. Little is known about the ecology of polyhydroxyalkanoate-producing bacteria. To analyse the occurrence of this specific group on/in seven different plant species, a combined strategy containing culture-dependent and -independent methods was applied. Using microbial fingerprint techniques (single-strand conformation polymorphism analysis with specific primers for phaC gene encoding the key enzyme of the polyhydroxyalkanoate synthesis), a high number of bands were especially found for the rhizosphere. Furthermore, cluster analysis revealed plant species-specific communities. Isolation of bacteria, recognition of brightly refractile cytoplasmatic inclusions, lipophilic stainings and a PCR strategy targeted on the phaC gene were used as a culture-dependent strategy for the detection of polyhydroxyalkanoate-producing bacteria. Results again represent a high degree of plant specificity: the rhizosphere of sugar beet contained the highest number of positive strains. This was confirmed by quantitative PCR: the relative copy number of phaC was statistically and significantly enhanced in all rhizospheres in comparison with bulk soil. New polyhydroxyalkanoate-producing bacterial species were detected: for example, Burkholderia terricola, Lysobacter gummosus, Pseudomonas extremaustralis, Pseudomonas brassicacearum and Pseudomonas orientalis. Our results confirm the hypothesis that the rhizosphere is an interesting hidden reservoir for polyhydroxyalkanoate producers.

  16. Coupling granule properties and granulation rates in high-shear granulation

    NARCIS (Netherlands)

    Biggs, CA; Sanders, C; Scott, AC; Willemse, AW; Hoffman, AC; Instone, T; Salman, AD; Hounslow, MJ

    2003-01-01

    It is possible to link granulation rates to granule properties. The linkage is by multiple dimension population balance equations that, by means of simplifying assumptions, can be reduced to multiple one-dimensional (1-D) population balance equations (PBES). Using simple physically based models,

  17. Evaluation of the Fertilizer Granules Strength Obtained from Plate Granulation with Different Angle of Granulation Blade

    Directory of Open Access Journals (Sweden)

    Leszczuk Tomasz

    2014-09-01

    Full Text Available The goal of the paper was to assess the strength of the fertilizer granules obtained by non-pressure granulation method. The granulation process was carried out in plate granulator, according to the three-level experiment plan. A mixture of raw materials prepared in a Polish factory of agrochemicals for agriculture and horticulture was used as a study material and water was used as a wetting liquid. Granulator design parameters and process parameters were treated as entrance sizes of the experiment. Three different angles of granulation blade were used in experiments. This paper presents: the results of study of equivalent diameter size and the impact of changes in the angle of granulating blade on the strength of obtained granulate. Pfost apparatus and a set of sieves used in granulometric sieve were utilized in this study. A relation was suggested P∞ = f(α, ϰ, n, ww, t. The results were presented in the form of graphs and tables. Conclusions were presented.

  18. Granulation of acetaminophen by a rotating fluidized-bed granulator.

    Science.gov (United States)

    Kawaguchi, T; Sunada, H; Yonezawa, Y; Danjo, K; Hasegawa, M; Makino, T; Sakamoto, H; Fujita, K; Tanino, T; Kokubo, H

    2000-01-01

    The purpose of this research was to evaluate the use of a rotating fluidized-bed granulator to produce acetaminophen granules with sufficient binding force between particles and good plasticity in tablets. Ethenzamide and ascorbic acid were used to compare the relationship between granulation and the sample wetness. It was revealed that a blade rotation rate of 300 rpm, inlet air flow rate of 42 m3/hr, and spraying pressure of 1.5 kg/cm3 produced tablets with the best properties. The granule and tablet properties of ethenzamide and ascorbic acid were compared to those of acetaminophen. These compounds showed different wetting behaviors with water and different compression behaviors. With an increase in medicament content, tablet hardness increased except for the ascorbic acid formulation. Capping and sticking were observed in acetaminophen and in ascorbic acid, respectively, and acetaminophen and ethenzamide showed prolonged disintegration time.

  19. Linking granulation performance with residence time and granulation liquid distributions in twin-screw granulation: An experimental investigation

    DEFF Research Database (Denmark)

    Kumar, Ashish; Alakarjula, Maija; Vanhoorne, Valérie

    2016-01-01

    elements in the granulator screw allowing the production of granules with a size distribution appropriate for tableting. The distribution of residence time and granulation liquid is governed by the field conditions (such as location and length of mixing zones) in the twin-screw granulator, thus contain...

  20. Recovery of polyhydroxyalkanoates from municipal secondary wastewater sludge.

    Science.gov (United States)

    Kumar, Manish; Ghosh, Pooja; Khosla, Khushboo; Thakur, Indu Shekhar

    2018-05-01

    In the current study, the feasibility of utilizing municipal secondary wastewater sludge for Polyhydroxyalkanoate (PHA) extraction was improved by optimization of various parameters (temperature, duration and concentration of sludge solids). Optimized process parameters resulted in PHA recovery of 0.605 g, significantly higher than un-optimized conditions. The characterization of PHA was carried out by GC-MS, FT-IR and NMR ( 1 H and 13 C) spectroscopy. The PHA profile was found to be dominated by mcl PHA (58%) along with other diverse PHA. The results of the present study show rich diversity of PHA extracted from a raw material which is readily available at minimal cost. In conclusion, exploring the potential of wastes for production of bioplastics not only reduces the cost of bioplastic production, but also provides a sustainable means for waste management. Copyright © 2018 Elsevier Ltd. All rights reserved.

  1. Polyhydroxyalkanoates: A way to sustainable development of bioplastics

    Directory of Open Access Journals (Sweden)

    Roopesh Jain

    2010-01-01

    Full Text Available This paper reviews role of polyhydroxyalkanoates (PHAs for sustainable development of bioplastics. PHAs are polyesters of hydroxyalkanoates with the general structural and have been investigated by biologists, chemists, engineers and other experts over the past many years. Bio-based and biodegradable plastics can form the basis for environmentally referable and sustainable alternative to current materials based exclusively on petroleum feed stocks. The result of the efforts made by scientist sought solution in form of biopolymer obtained either from microorganism or plants source and likely to replace currently used synthetic polymers as bioplastic. Applications of PHA as bioplastics, fine chemicals, implant biomaterials, and medicines have been developed. The PHA polymers promise to extend significantly the range of biomaterials as suitable alternative of plastic.

  2. A microbial polyhydroxyalkanoates (PHA) based bio- and materials industry.

    Science.gov (United States)

    Chen, Guo-Qiang

    2009-08-01

    Biopolyesters polyhydroxyalkanoates (PHA) produced by many bacteria have been investigated by microbiologists, molecular biologists, biochemists, chemical engineers, chemists, polymer experts and medical researchers. PHA applications as bioplastics, fine chemicals, implant biomaterials, medicines and biofuels have been developed and are covered in this critical review. Companies have been established or involved in PHA related R&D as well as large scale production. Recently, bacterial PHA synthesis has been found to be useful for improving robustness of industrial microorganisms and regulating bacterial metabolism, leading to yield improvement on some fermentation products. In addition, amphiphilic proteins related to PHA synthesis including PhaP, PhaZ or PhaC have been found to be useful for achieving protein purification and even specific drug targeting. It has become clear that PHA and its related technologies are forming an industrial value chain ranging from fermentation, materials, energy to medical fields (142 references).

  3. Collages of granulation pictures

    Science.gov (United States)

    Dunn, R. B.; November, L. J.

    Two small-area selection schemes are applied to CCD observations of solar granulation. One procedure, referred to as mosaic, divides a 128 x 128 array into 64 subarrays of 16 x 16 pixels; the rms contrast of the fine structure is measured and compared in order to develop a mosaic of the subarrays. The second technique, collage, involves calculating rms values within a sliding Gaussian window and gating the pixel into the final image. Methods for assessing seeing quality, which involve the calculation of rms after high-pass filtering, are examined; a simple high-pass filter or an edge-locating function can be utilized for filtering. The rms map is then formed from the convolution of a Gaussian with either the high-pass or the Laplacian filters. The usefulness of the two procedures is demonstrated by applying the mosaic and collage processes to data recorded on July 17, 1983 with a CCD device on the NSO/Sac Peak Vacuum Tower Telescope.

  4. Linking granulation performance with residence time and granulation liquid distributions in twin-screw granulation: An experimental investigation.

    Science.gov (United States)

    Kumar, Ashish; Alakarjula, Maija; Vanhoorne, Valérie; Toiviainen, Maunu; De Leersnyder, Fien; Vercruysse, Jurgen; Juuti, Mikko; Ketolainen, Jarkko; Vervaet, Chris; Remon, Jean Paul; Gernaey, Krist V; De Beer, Thomas; Nopens, Ingmar

    2016-07-30

    Twin-screw granulation is a promising wet granulation technique for the continuous manufacturing of pharmaceutical solid dosage forms. A twin screw granulator displays a short residence time. Thus, the solid-liquid mixing must be achieved quickly by appropriate arrangement of transport and kneading elements in the granulator screw allowing the production of granules with a size distribution appropriate for tableting. The distribution of residence time and granulation liquid is governed by the field conditions (such as location and length of mixing zones) in the twin-screw granulator, thus contain interesting information on granulation time, mixing and resulting sub-processes such as wetting, aggregation and breakage. In this study, the impact of process (feed rate, screw speed and liquid-to-solid ratio) and equipment parameters (number of kneading discs and stagger angle) on the residence time (distribution), the granulation liquid-powder mixing and the resulting granule size distributions during twin-screw granulation were investigated. Residence time and axial mixing data was extracted from tracer maps and the solid-liquid mixing was quantified from moisture maps, obtained by monitoring the granules at the granulator outlet using near infra-red chemical imaging (NIR-CI). The granule size distribution was measured using the sieving method. An increasing screw speed dominantly reduced the mean residence time. Interaction of material throughput with the screw speed and with the number of kneading discs led to most variation in the studied responses including residence time and mixing capacity. At a high screw speed, granulation yield improved due to high axial mixing. However, increasing material throughput quickly lowers the yield due to insufficient mixing of liquid and powder. Moreover, increasing liquid-to-solid ratio resulted in more oversized granules, and the fraction of oversized granules further increased at higher throughput. Although an increasing number

  5. Granulation techniques and technologies: recent progresses

    OpenAIRE

    Shanmugam, Srinivasan

    2015-01-01

    Granulation, the process of particle enlargement by agglomeration technique, is one of the most significant unit operations in the production of pharmaceutical dosage forms, mostly tablets and capsules. Granulation process transforms fine powders into free-flowing, dust-free granules that are easy to compress. Nevertheless, granulation poses numerous challenges due to high quality requirement of the formed granules in terms of content uniformity and physicochemical proper...

  6. OPTIMIZATION OF GRANULATION TECHNIQUES FOR DEVELOPMENT OF TABLET DOSAGE FORM

    OpenAIRE

    V. B. Khot*, D.A. Bhagwat, J. I. D'Souza, S. S. Shelake, S. V. Patil

    2017-01-01

    The purpose of this study was to optimize the best granulation techniques for development of tablet dosage form. The present study explains comparative study of different wet granulation techniques including Planetary mixer granulation, Rapid mixer granulation, Fluid bed granulation with Direct compression method. Similar formulations were used to evaluate Planetary mixer granulation, Rapid mixer granulation and Fluid bed granulation method. The granules prepared by different techniques were ...

  7. Granulopoiesis and granules of human neutrophils

    DEFF Research Database (Denmark)

    Cowland, Jack B; Borregaard, Niels

    2016-01-01

    Granules are essential for the ability of neutrophils to fulfill their role in innate immunity. Granule membranes contain proteins that react to environmental cues directing neutrophils to sites of infection and initiate generation of bactericidal oxygen species. Granules are densely packed...... with proteins that contribute to microbial killing when liberated to the phagosome or extracellularly. Granules are, however, highly heterogeneous and are traditionally subdivided into azurophil granules, specific granules, and gelatinase granules in addition to secretory vesicles. This review will address...... issues pertinent to formation of granules, which is a process intimately connected to maturation of neutrophils from their precursors in the bone marrow. We further discuss possible mechanisms by which decisions are made regarding sorting of proteins to constitutive secretion or storage in granules...

  8. Conversion of industrial food wastes by Alcaligenes latus into polyhydroxyalkanoates.

    Science.gov (United States)

    Yu, P H; Chua, H; Huang, A L; Ho, K P

    1999-01-01

    Broader usage of biodegradable plastics in packaging and disposable products as a solution to environmental problems would heavily depend on further reduction of costs and the discovery of novel biodegradable plastics with improved properties. As the first step in our pursuit of eventual usage of industrial food wastewater as nutrients for microorganisms to synthesise environmental-friendly bioplastics, we investigated the usage of soya wastes from a soya milk dairy, and malt wastes from a beer brewery plant as the carbon sources for the production of polyhydroxyalkanoates (PHA) by selected strain of microorganism. Bench experiments showed that Alcaligenes latus DSM 1124 used the nutrients from malt and soya wastes to biosynthesise PHAs. The final dried cell mass and specific polymer production of A. latus DSM 1124 were 32g/L and 70% polymer/cells (g/g), 18.42 g/L and 32.57% polymer/cell (g/g), and 28 g/L and 36% polymer/cells (g/g), from malt waste, soya waste, and from sucrose, respectively. These results suggest that many types of food wastes might be used as the carbon source for the production of PHA.

  9. Carbon Sources for Polyhydroxyalkanoates and an Integrated Biorefinery.

    Science.gov (United States)

    Jiang, Guozhan; Hill, David J; Kowalczuk, Marek; Johnston, Brian; Adamus, Grazyna; Irorere, Victor; Radecka, Iza

    2016-07-19

    Polyhydroxyalkanoates (PHAs) are a group of bioplastics that have a wide range of applications. Extensive progress has been made in our understanding of PHAs' biosynthesis, and currently, it is possible to engineer bacterial strains to produce PHAs with desired properties. The substrates for the fermentative production of PHAs are primarily derived from food-based carbon sources, raising concerns over the sustainability of their production in terms of their impact on food prices. This paper gives an overview of the current carbon sources used for PHA production and the methods used to transform these sources into fermentable forms. This allows us to identify the opportunities and restraints linked to future sustainable PHA production. Hemicellulose hydrolysates and crude glycerol are identified as two promising carbon sources for a sustainable production of PHAs. Hemicellulose hydrolysates and crude glycerol can be produced on a large scale during various second generation biofuels' production. An integration of PHA production within a modern biorefinery is therefore proposed to produce biofuels and bioplastics simultaneously. This will create the potential to offset the production cost of biofuels and reduce the overall production cost of PHAs.

  10. Co-production of microbial polyhydroxyalkanoates with other chemicals.

    Science.gov (United States)

    Li, Tian; Elhadi, Dina; Chen, Guo-Qiang

    2017-09-01

    Engineering microorganisms capable of simultaneously accumulating multiple products are economically attractive for biotechnology. Polyhydroxyalkanoates (PHA) or microbial bioplastics are promising as biodegradable plastics to address environmental concerns resulted from plastic wastes accumulation. Unfortunately, PHA production is still limited and cannot compete with the chemically synthesized plastics due to their high production cost. Efforts have been devoted to reduce PHA production cost by employing PHA co-production with other valuable chemicals. Successful co-productions of PHA have been demonstrated with amino acids, proteins, alcohols, hydrogen, biosurfactants, exopolysaccharides and several fine chemicals. The strategy allows recovering PHA from the cells and other value-added products from the no-cells broths. Numerous successful strategies have been developed for minimizing the substrate cost and improving the product yields. This paper reviews the recent strategies developed in PHA co-production with other compounds, discusses the challenges and prospective during the scale up of the co-production strategies. Copyright © 2017 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  11. Polyhydroxyalkanoate production from crude glycerol by newly isolated Pandoraea sp.

    Directory of Open Access Journals (Sweden)

    Fabrício Coutinho de Paula

    2017-04-01

    Full Text Available A new bacterial strain was isolated from Atlantic rainforest in Brazil for polyhydroxyalkanoate (PHA production utilizing crude glycerol from biodiesel industry (CG and it was identified as Pandoraea sp. MA03. Shake flask experiments were performed at 10–50 g L−1 carbon source and showed the best values of poly(3-hydroxybutyrate (P3HB production from CG cultivations compared to pure glycerol, with a polymer accumulation ranging from 49.0% to 63.6% cell dry weight (CDW. The results obtained from this study showed a positive effect of contaminant NaCl on P3HB synthesis up to 30 g L−1 CG. Poly(3-hydroxybutyrate-co-3-hydroxyvalerate [P(3HB-co-3HV] production was obtained from CG plus propionic acid with up to 25.9 mol% 3HV. Since it is interesting the utilization of CG for obtaining added-value products along with biodiesel, this study reported a novel and promising PHA-producing bacterial strain as an additional effort to enhance the viability of a sustainable industry based on biofuels and biopolymers.

  12. Producing microbial polyhydroxyalkanoate (PHA) biopolyesters in a sustainable manner.

    Science.gov (United States)

    Koller, Martin; Maršálek, Lukáš; de Sousa Dias, Miguel Miranda; Braunegg, Gerhart

    2017-07-25

    Sustainable production of microbial polyhydroxyalkanoate (PHA) biopolyesters on a larger scale has to consider the "four magic e": economic, ethical, environmental, and engineering aspects. Moreover, sustainability of PHA production can be quantified by modern tools of Life Cycle Assessment. Economic issues are to a large extent affected by the applied production mode, downstream processing, and, most of all, by the selection of carbon-rich raw materials as feedstocks for PHA production by safe and naturally occurring wild type microorganisms. In order to comply with ethics, such raw materials should be used which do not interfere with human nutrition and animal feed supply chains, and shall be convertible towards accessible carbon feedstocks by simple methods of upstream processing. Examples were identified in carbon-rich waste materials from various industrial braches closely connected to food production. Therefore, the article shines a light on hetero-, mixo-, and autotrophic PHA production based on various industrial residues from different branches. Emphasis is devoted to the integration of PHA-production based on selected raw materials into the holistic patterns of sustainability; this encompasses the choice of new, powerful microbial production strains, non-hazardous, environmentally benign methods for PHA recovery, and reutilization of waste streams from the PHA production process itself. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Carbon roadmap from syngas to polyhydroxyalkanoates in Rhodospirillum rubrum.

    Science.gov (United States)

    Revelles, O; Tarazona, N; García, J L; Prieto, M A

    2016-02-01

    The gasification of organic waste materials to synthesis gas (syngas), followed by microbial fermentation, provides a significant resource for generating bioproducts such as polyhydroxyalkanoates (PHA). The anaerobic photosynthetic bacterium, Rhodospirillum rubrum, is an organism particularly attractive for the bioconversion of syngas into PHAs. In this study, a quantitative physiological analysis of R. rubrum was carried out by implementing GC-MS and HPLC techniques to unravel the metabolic pathway operating during syngas fermentation that leads to PHA production. Further, detailed investigations of the central carbon metabolites using (13) C-labelled substrate showed significant CO2 assimilation (of 40%) into cell material and PHA from syngas carbon fraction. By a combination of quantitative gene expression and enzyme activity analyses, the main role of carboxylases from the central carbon metabolism in CO2 assimilation was shown, where the Calvin-Benson-Bassham cycle (CBB) played a minor role. This knowledge sheds light about the biochemical pathways that contribute to synthesis of PHA during syngas fermentation being valuable information to further optimize the fermentation process. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

  14. Start a Research on Biopolymer Polyhydroxyalkanoate (PHA: A Review

    Directory of Open Access Journals (Sweden)

    Giin-Yu Amy Tan

    2014-03-01

    Full Text Available With the impending fossil fuel crisis, the search for and development of alternative chemical/material substitutes is pivotal in reducing mankind’s dependency on fossil resources. One of the potential substitute candidates is polyhydroxyalkanoate (PHA. PHA is a carbon-neutral and valuable polymer that could be produced from many renewable carbon sources by microorganisms, making it a sustainable and environmental-friendly material. At present, PHA is not cost competitive compared to fossil-derived products. Encouraging and intensifying research work on PHA is anticipated to enhance its economic viability in the future. The development of various biomolecular and chemical techniques for PHA analysis has led to the identification of many PHA-producing microbial strains, some of which are deposited in culture collections. Research work on PHA could be rapidly initiated with these ready-to-use techniques and microbial strains. This review aims to facilitate the start-up of PHA research by providing a summary of commercially available PHA-accumulating microbial cultures, PHA biosynthetic pathways, and methods for PHA detection, extraction and analysis.

  15. Carbon Sources for Polyhydroxyalkanoates and an Integrated Biorefinery

    Directory of Open Access Journals (Sweden)

    Guozhan Jiang

    2016-07-01

    Full Text Available Polyhydroxyalkanoates (PHAs are a group of bioplastics that have a wide range of applications. Extensive progress has been made in our understanding of PHAs’ biosynthesis, and currently, it is possible to engineer bacterial strains to produce PHAs with desired properties. The substrates for the fermentative production of PHAs are primarily derived from food-based carbon sources, raising concerns over the sustainability of their production in terms of their impact on food prices. This paper gives an overview of the current carbon sources used for PHA production and the methods used to transform these sources into fermentable forms. This allows us to identify the opportunities and restraints linked to future sustainable PHA production. Hemicellulose hydrolysates and crude glycerol are identified as two promising carbon sources for a sustainable production of PHAs. Hemicellulose hydrolysates and crude glycerol can be produced on a large scale during various second generation biofuels’ production. An integration of PHA production within a modern biorefinery is therefore proposed to produce biofuels and bioplastics simultaneously. This will create the potential to offset the production cost of biofuels and reduce the overall production cost of PHAs.

  16. Biotechnological conversion of spent coffee grounds into polyhydroxyalkanoates and carotenoids.

    Science.gov (United States)

    Obruca, Stanislav; Benesova, Pavla; Kucera, Dan; Petrik, Sinisa; Marova, Ivana

    2015-12-25

    Coffee is one of the world's most popular beverages and has been growing steadily in commercial importance. Nowadays, coffee is the second largest traded commodity in the world, after petroleum. Hence, coffee industry is responsible for the generation of large amounts of waste, especially spent coffee grounds (SCG). Various attempts to valorize this waste stream of coffee industry were made. This article summarizes our research and publications aiming at the conversion of SCG into valuable products - polyhydroxyalkanoates (PHAs) and carotenoids. At first, oil extracted from SCG (approx. 15 wt% oil in SCG) can be efficiently (YP/S=0.82 g/g) converted into PHA employing Cupriavidus necator H16. Further, the solid residues after oil extraction can be hydrolyzed (by the combination of chemical and enzymatic hydrolysis) yielding fermentable sugars, which can be further used as a substrate for the production of PHAs employing Bacillus megaterium (YP/S=0.04 g/g) or Burkholderia cepacia (YP/S=0.24 g/g). Alternatively, SCG hydrolysate can be used as a substrate for biotechnological production of carotenoids by carotenogenic yeast Sporobolomyces roseus. Solid residues after either oil extraction or hydrolysis can be used as fuel in industrial boilers to generate heat and energy. Therefore, entire biomass of SCG can be used for sustainable production of PHAs and/or carotenoids employing bio-refinery approach. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Community proteomics provides functional insight into polyhydroxyalkanoate production by a mixed microbial culture cultivated on fermented dairy manure.

    Science.gov (United States)

    Hanson, Andrea J; Guho, Nicholas M; Paszczynski, Andrzej J; Coats, Erik R

    2016-09-01

    Polyhydroxyalkanoates (PHAs) are bio-based, biodegradable polyesters that can be produced from organic-rich waste streams using mixed microbial cultures (MMCs). To maximize PHA production, MMCs are enriched for bacteria with a high polymer storage capacity through the application of aerobic dynamic feeding (ADF) in a sequencing batch reactor (SBR), which consequently induces a feast-famine metabolic response. Though the feast-famine response is generally understood empirically at a macro-level, the molecular level is less refined. The objective of this study was to investigate the microbial community composition and proteome profile of an enriched MMC cultivated on fermented dairy manure. The enriched MMC exhibited a feast-famine response and was capable of producing up to 40 % (wt. basis) PHA in a fed-batch reactor. High-throughput 16S rRNA gene sequencing revealed a microbial community dominated by Meganema, a known PHA-producing genus not often observed in high abundance in enrichment SBRs. The application of the proteomic methods two-dimensional electrophoresis and LC-MS/MS revealed PHA synthesis, energy generation, and protein synthesis prominently occurring during the feast phase, corroborating bulk solution variable observations and theoretical expectations. During the famine phase, nutrient transport, acyl-CoA metabolism, additional energy generation, and housekeeping functions were more pronounced, informing previously under-determined MMC functionality under famine conditions. During fed-batch PHA production, acetyl-CoA acetyltransferase and PHA granule-bound phasin proteins were in increased abundance relative to the SBR, supporting the higher PHA content observed. Collectively, the results provide unique microbial community structural and functional insight into feast-famine PHA production from waste feedstocks using MMCs.

  18. Multidimensional modelling of anaerobic granules

    DEFF Research Database (Denmark)

    Picioreanu, C.; Batstone, Damien J.; van Loosdrecht, M.C.M.

    2005-01-01

    A multispecies, two- and three-dimensional model was developed, based on a previously published planar biofilm model, and the biochemical structure of the ADM1. Several soluble substrates diffuse and react in the granule. Local pH is calculated from acid-base equilibria and charge balance...

  19. Cultures of Cerebellar Granule Neurons

    OpenAIRE

    sprotocols

    2014-01-01

    Authors: Parizad M. Bilimoria and Azad Bonni1 Corresponding author ([]()) ### INTRODUCTION Primary cultures of granule neurons from the post-natal rat cerebellum provide an excellent model system for molecular and cell biological studies of neuronal development and function. The cerebellar cortex, with its highly organized structure and few neuronal subtypes, offers a well-characterized neural circuitry. Many fundamental insight...

  20. Improving solid dosage forms with dry granulation

    OpenAIRE

    Boswell, Steve; Smith, Geoff

    2011-01-01

    Although tablet manufacture is traditionally a batchbased wet granulation process, there are many advantages to be gained by adopting dry granulation, including lower costs and increased yields. The simplicity of dry granulation could also enable it to become one of the main technologies for continuous processing

  1. Molecular composition of IMP1 ribonucleoprotein granules

    DEFF Research Database (Denmark)

    Jønson, Lars; Vikesaa, Jonas; Krogh, Anders

    2007-01-01

    , and in motile cells IMP-containing granules are dispersed around the nucleus and in cellular protrusions. We isolated the IMP1-containing RNP granules and found that they represent a unique RNP entity distinct from neuronal hStaufen and/or fragile X mental retardation protein granules, processing bodies...

  2. Momordica Foetida (cucurbitacea) A Potential Laxative Granule ...

    African Journals Online (AJOL)

    There has been a folklore belief that the plant Momordica foetida has a laxative effect. This paper attempted to investigate this claim. The dried extract was granulated with cornstarch mucilage to produce free flowing granules. Capsules containing 500mg of the granules were hand filled. The capsules were evaluated in ...

  3. Statistical analysis and comparison of a continuous high shear granulator with a twin screw granulator: Effect of process parameters on critical granule attributes and granulation mechanisms.

    Science.gov (United States)

    Meng, Wei; Kotamarthy, Lalith; Panikar, Savitha; Sen, Maitraye; Pradhan, Shankali; Marc, Michaelis; Litster, James D; Muzzio, Fernando J; Ramachandran, Rohit

    2016-11-20

    This study is concerned with identifying the design space of two different continuous granulators and their respective granulation mechanisms. Performance of a continuous high shear granulator and a twin screw granulator with paracetamol formulations were examined by face-centered cubic design, which focused on investigating key performance metrics, namely, granule size, porosity, flowability and particle morphology of granules as a function of essential input process parameters (liquid content, throughput and rotation speed). Liquid and residence time distribution tests were also performed to gain insights into the liquid-powder mixing and flow behavior. The results indicated that continuous high shear granulation was more sensitive to process variation and produced spherical granules with monomodal size distribution and distinct internal structure and strength variation. Twin screw granulation with such a particular screw configuration showed narrower design space and granules were featured with multimodal size distribution, irregular shape, less detectible porosity difference and tighter range of strength. Granulation mechanisms explored on the basis of nucleation and growth regime maps revealed that for most cases liquid binder was uniformly distributed with fast droplet penetration into the powder bed and that granule consolidation and coalescence mainly took place in the nucleation, steady growth and rapid growth regimes. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Renewable alkenes from the hydrothermal treatment of polyhydroxyalkanoates-containing sludge

    NARCIS (Netherlands)

    Torri, Cristian; Detert Oude Weme, Tom; Samorì, Chiara; Kiwan, Alisar; Brilman, Derk W.F.

    2017-01-01

    Polyhydroxyalkanoates (PHA) are a key constituent of excess sludge produced by Aerobic Sewage Sludge Treatment plants. The accumulation of significant amount of PHA inside aerobic microbial cells occurs when a surplus of an easily degradable carbon source (e.g., volatile fatty acids, VFA) is found

  5. Vortex rings and the solar granulation

    Science.gov (United States)

    Arendt, Steve

    1994-01-01

    Observations indicate that solar granules have the flow topology of updraft vortex loops. We interpret granule behavior in terms of the mutual and self-interactions of such loops. In particular, the expansion phase that granules commonly undergo is explained by the self-expansion of a vortex ring in a stratified fluid. For a range of granular parameters, we find that the expansion velocity of a vortex ring varies from 0.7 to 1.5 times the maximum surface flow velocity, in agreement with granule observations. We also present speculation on the nature of granule fragmentation.

  6. Neutrophil granules in health and disease

    DEFF Research Database (Denmark)

    Häger, M; Cowland, J B; Borregaard, N

    2010-01-01

    Neutrophil granules store proteins that are critically important for the neutrophil to move from the vascular bed to tissues and to kill microorganisms. This is illustrated in nature when individual proteins are deleted due to inherited mutations of their cognate genes, and such deficiencies result...... in the conditions leucocyte adhesion deficiency and chronic granulomatous disease. The granules of the neutrophil have traditionally been divided into two or three major types but are instead a continuum where several subtypes can be identified with differences in protein content and propensity for mobilization....... This is explained by the 'targeting by timing hypothesis' which states that granules are filled with granule proteins that are synthesized at the time the granule is formed. The heterogeneity of granules arises because the synthesis of granule proteins is individually controlled and major differences exist...

  7. Effect of process variables on the production of Polyhydroxyalkanoates by activated sludge

    Directory of Open Access Journals (Sweden)

    Mokhtarani Nader

    2012-09-01

    Full Text Available Abstract Polyhydroxyalkanoates are known to be temporarily stored by microorganisms in activated sludge, especially in anaerobic-aerobic processes. Due to the problems resulted from the disposals of plastic wastes and excess sludge of wastewater treatment plants, the production of polyhydroxyalkanoates by treating activated sludge and determining the effect of process variables were the main issues of this paper. In this research, an anaerobic-aerobic sequencing batch reactor was used to make microorganism adapted and a batch aerobic reactor was used for enriching them. The variables affecting polyhydroxyalkanoates production including aeration time, sludge retention time, and volatile fatty acids concentration of the influent in sequencing batch reactor, and also carbon to nitrogen ratio and cultivation time in polymer production reactor, were investigated using Taguchi statistical approach to determine optimum conditions. The maximum polymer production of 29% was achieved at sludge retention time of 5–10 days, aeration time of 2 hours, supplementation of 40% of volatile fatty acids in the influent and increasing of carbon to nitrogen ratio of polymer production reactor to above 25 g/g. Based on the results, in optimum conditions, the volatile fatty acids concentration which increased the production of polyhydroxyalkanoates up to 49% was the most effective variable. Carbon to nitrogen ratio, sludge retention time and aeration time were ranked as the next affecting parameters. Although the polyhydroxyalkanoates content achieved in present study is much lower than that by pure culture, but the proposed method may still serve well as an environmental friendly means to convert waste into valuable product.

  8. Effect of Process Variables on the Production of Polyhydroxyalkanoates by Activated Sludge

    Directory of Open Access Journals (Sweden)

    Nader Mokhtarani

    2012-09-01

    Full Text Available Polyhydroxyalkanoates are known to be temporarily stored by microorganisms in activated sludge, especially in anaerobic-aerobic processes. Due to the problems resulted from the disposals of plastic wastes and excess sludge of wastewater treatment plants, the production of polyhydroxyalkanoates by treating activated sludge anddetermining the effect of process variables were the main issues of this paper. In this research, an anaerobic-aerobic sequencing batch reactor was used to make microorganism adapted and a batch aerobic reactor was used for enriching them. The variables affecting polyhydroxyalkanoates production including aeration time, sludge retention time, and volatile fatty acids concentration of the influent in sequencing batch reactor, and also carbon to nitrogenratio and cultivation time in polymer production reactor, were investigated using Taguchi statistical approach to determine optimum conditions. The maximum polymer production of 29% was achieved at sludge retention time of 5–10 days, aeration time of 2 hours, supplementation of 40% of volatile fatty acids in the influent and increasing of carbon to nitrogen ratio of polymer production reactor to above 25 g/g. Based on the results, in optimum conditions, the volatile fatty acids concentration which increased the production of polyhydroxyalkanoates up to 49% was the most effective variable. Carbon to nitrogen ratio, sludge retention time and aeration time were ranked as the next affecting parameters. Although the polyhydroxyalkanoates content achieved in present study is muchlower than that by pure culture, but the proposed method may still serve well as an environmental friendly means to convert waste into valuable product.

  9. Accumulation of a Polyhydroxyalkanoate Containing Primarily 3-Hydroxydecanoate from Simple Carbohydrate Substrates by Pseudomonas sp. Strain NCIMB 40135.

    Science.gov (United States)

    Haywood, G W; Anderson, A J; Ewing, D F; Dawes, E A

    1990-11-01

    A number of Pseudomonas species have been identified which accumulate a polyhydroxyalkanoate containing mainly 3-hydroxydecanoate monomers from sodium gluconate as the sole carbon source. One of these, Pseudomonas sp. strain NCIMB 40135, was further investigated and shown to accumulate such a polyhydroxyalkanoate from a wide range of carbon sources (C(2) to C(6)); however, when supplied with octanoic acid it produced a polyhydroxyalkanoate containing mainly 3-hydroxyoctanoate monomers. Polymer synthesis occurred in batch culture after cessation of growth due to exhaustion of nitrogen. In continuous culture under nitrogen limitation up to 16.9% (wt/wt) polyhydroxyalkanoate was synthesized from glucose as the carbon source. The monomer units are mainly of the R-(-) configuration. Nuclear magnetic resonance studies confirmed the composition of the polymer. Differential scanning calorimetry suggested that the solvent-extracted polymer contained a significant proportion of crystalline material. The weight-average molecular weight of the polymer from glucose-grown cells was 143,000.

  10. Markov properties of solar granulation

    Science.gov (United States)

    Asensio Ramos, A.

    2009-01-01

    Aims: We estimate the minimum length on which solar granulation can be considered to be a Markovian process. Methods: We measure the variation in the bright difference between two pixels in images of the solar granulation for different distances between the pixels. This scale-dependent data is empirically analyzed to find the minimum scale on which the process can be considered Markovian. Results: The results suggest that the solar granulation can be considered to be a Markovian process on scales longer than r_M=300-500 km. On longer length scales, solar images can be considered to be a Markovian stochastic process that consists of structures of size r_M. Smaller structures exhibit correlations on many scales simultaneously yet cannot be described by a hierarchical cascade in scales. An analysis of the longitudinal magnetic-flux density indicates that it cannot be a Markov process on any scale. Conclusions: The results presented in this paper constitute a stringent test for the realism of numerical magneto-hydrodynamical simulations of solar magneto-convection. In future exhaustive analyse, the non-Markovian properties of the magnetic flux density on all analyzed scales might help us to understand the physical mechanism generating the field that we detect in the solar surface.

  11. Protein mobility within secretory granules.

    Science.gov (United States)

    Weiss, Annita Ngatchou; Bittner, Mary A; Holz, Ronald W; Axelrod, Daniel

    2014-07-01

    We investigated the basis for previous observations that fluorescent-labeled neuropeptide Y (NPY) is usually released within 200 ms after fusion, whereas labeled tissue plasminogen activator (tPA) is often discharged over many seconds. We found that tPA and NPY are endogenously expressed in small and different subpopulations of bovine chromaffin cells in culture. We measured the mobility of these proteins (tagged with fluorophore) within the lumen of individual secretory granules in living chromaffin cells, and related their mobilities to postfusion release kinetics. A method was developed that is not limited by standard optical resolution, in which a bright flash of strongly decaying evanescent field (∼64 nm exponential decay constant) produced by total internal reflection (TIR) selectively bleaches cerulean-labeled protein proximal to the glass coverslip within individual granules. Fluorescence recovery occurred as unbleached protein from distal regions within the 300 nm granule diffused into the bleached proximal regions. The fractional bleaching of tPA-cerulean (tPA-cer) was greater when subsequently probed with TIR excitation than with epifluorescence, indicating that tPA-cer mobility was low. The almost equal NPY-cer bleaching when probed with TIR and epifluorescence indicated that NPY-cer equilibrated within the 300 ms bleach pulse, and therefore had a greater mobility than tPA-cer. TIR-fluorescence recovery after photobleaching revealed a significant recovery of tPA-cer (but not NPY-cer) fluorescence within several hundred milliseconds after bleaching. Numerical simulations, which take into account bleach duration, granule diameter, and the limited number of fluorophores in a granule, are consistent with tPA-cer being 100% mobile, with a diffusion coefficient of 2 × 10(-10) cm(2)/s (∼1/3000 of that for a protein of similar size in aqueous solution). However, the low diffusive mobility of tPA cannot alone explain its slow postfusion release. In the

  12. Increased accuracy of starch granule type quantification using mixture distributions

    OpenAIRE

    Tanaka, Emi; Ral, Jean-Phillippe F.; Li, Sean; Gaire, Raj; Cavanagh, Colin R.; Cullis, Brian R.; Whan, Alex

    2017-01-01

    Background The proportion of granule types in wheat starch is an important characteristic that can affect its functionality. It is widely accepted that granule types are either large, disc-shaped A-type granules or small, spherical B-type granules. Additionally, there are some reports of the tiny C-type granules. The differences between these granule types are due to its carbohydrate composition and crystallinity which is highly, but not perfectly, correlated with the granule size. A majority...

  13. Metabolic modelling of polyhydroxyalkanoate copolymers production by mixed microbial cultures

    Directory of Open Access Journals (Sweden)

    Reis Maria AM

    2008-07-01

    Full Text Available Abstract Background This paper presents a metabolic model describing the production of polyhydroxyalkanoate (PHA copolymers in mixed microbial cultures, using mixtures of acetic and propionic acid as carbon source material. Material and energetic balances were established on the basis of previously elucidated metabolic pathways. Equations were derived for the theoretical yields for cell growth and PHA production on mixtures of acetic and propionic acid as functions of the oxidative phosphorylation efficiency, P/O ratio. The oxidative phosphorylation efficiency was estimated from rate measurements, which in turn allowed the estimation of the theoretical yield coefficients. Results The model was validated with experimental data collected in a sequencing batch reactor (SBR operated under varying feeding conditions: feeding of acetic and propionic acid separately (control experiments, and the feeding of acetic and propionic acid simultaneously. Two different feast and famine culture enrichment strategies were studied: (i either with acetate or (ii with propionate as carbon source material. Metabolic flux analysis (MFA was performed for the different feeding conditions and culture enrichment strategies. Flux balance analysis (FBA was used to calculate optimal feeding scenarios for high quality PHA polymers production, where it was found that a suitable polymer would be obtained when acetate is fed in excess and the feeding rate of propionate is limited to ~0.17 C-mol/(C-mol.h. The results were compared with published pure culture metabolic studies. Conclusion Acetate was more conducive toward the enrichment of a microbial culture with higher PHA storage fluxes and yields as compared to propionate. The P/O ratio was not only influenced by the selected microbial culture, but also by the carbon substrate fed to each culture, where higher P/O ratio values were consistently observed for acetate than propionate. MFA studies suggest that when mixtures of

  14. Production of functionalized polyhydroxyalkanoates by genetically modified Methylobacterium extorquens strains.

    Science.gov (United States)

    Höfer, Philipp; Choi, Young J; Osborne, Michael J; Miguez, Carlos B; Vermette, Patrick; Groleau, Denis

    2010-09-16

    Methylotrophic (methanol-utilizing) bacteria offer great potential as cell factories in the production of numerous products from biomass-derived methanol. Bio-methanol is essentially a non-food substrate, an advantage over sugar-utilizing cell factories. Low-value products as well as fine chemicals and advanced materials are envisageable from methanol. For example, several methylotrophic bacteria, including Methylobacterium extorquens, can produce large quantities of the biodegradable polyester polyhydroxybutyric acid (PHB), the best known polyhydroxyalkanoate (PHA). With the purpose of producing second-generation PHAs with increased value, we have explored the feasibility of using M. extorquens for producing functionalized PHAs containing C-C double bonds, thus, making them amenable to future chemical/biochemical modifications for high value applications. Our proprietary M. extorquens ATCC 55366 was found unable to yield functionalized PHAs when fed methanol and selected unsaturated carboxylic acids as secondary substrates. However, cloning of either the phaC1 or the phaC2 gene from P. fluorescens GK13, using an inducible and regulated expression system based on cumate as inducer (the cumate switch), yielded recombinant M. extorquens strains capable of incorporating modest quantities of C-C double bonds into PHA, starting from either C6= and/or C8=. The two recombinant strains gave poor results with C11=. The strain containing the phaC2 gene was better at using C8= and at incorporating C-C double bonds into PHA. Solvent fractioning indicated that the produced polymers were PHA blends that consequently originated from independent actions of the native and the recombinant PHA synthases. This work constitutes an example of metabolic engineering applied to the construction of a methanol-utilizing bacterium capable of producing functionalized PHAs containing C-C double bonds. In this regard, the PhaC2 synthase appeared superior to the PhaC1 synthase at utilizing C8= as

  15. Production of functionalized polyhydroxyalkanoates by genetically modified Methylobacterium extorquens strains

    Directory of Open Access Journals (Sweden)

    Miguez Carlos B

    2010-09-01

    Full Text Available Abstract Background Methylotrophic (methanol-utilizing bacteria offer great potential as cell factories in the production of numerous products from biomass-derived methanol. Bio-methanol is essentially a non-food substrate, an advantage over sugar-utilizing cell factories. Low-value products as well as fine chemicals and advanced materials are envisageable from methanol. For example, several methylotrophic bacteria, including Methylobacterium extorquens, can produce large quantities of the biodegradable polyester polyhydroxybutyric acid (PHB, the best known polyhydroxyalkanoate (PHA. With the purpose of producing second-generation PHAs with increased value, we have explored the feasibility of using M. extorquens for producing functionalized PHAs containing C-C double bonds, thus, making them amenable to future chemical/biochemical modifications for high value applications. Results Our proprietary M. extorquens ATCC 55366 was found unable to yield functionalized PHAs when fed methanol and selected unsaturated carboxylic acids as secondary substrates. However, cloning of either the phaC1 or the phaC2 gene from P. fluorescens GK13, using an inducible and regulated expression system based on cumate as inducer (the cumate switch, yielded recombinant M. extorquens strains capable of incorporating modest quantities of C-C double bonds into PHA, starting from either C6= and/or C8=. The two recombinant strains gave poor results with C11=. The strain containing the phaC2 gene was better at using C8= and at incorporating C-C double bonds into PHA. Solvent fractioning indicated that the produced polymers were PHA blends that consequently originated from independent actions of the native and the recombinant PHA synthases. Conclusions This work constitutes an example of metabolic engineering applied to the construction of a methanol-utilizing bacterium capable of producing functionalized PHAs containing C-C double bonds. In this regard, the PhaC2 synthase

  16. Twin screw granulation - review of current progress.

    Science.gov (United States)

    Thompson, M R

    2015-01-01

    Twin screw granulation (TSG) is a new process of interest to the pharmaceutical community that can continuously wet granulate powders, doing so at lower liquid concentrations and with better product consistency than found by a high shear batch mixer. A considerable body of research has evolved over the short time since this process was introduced but generally with little comparison of results. A certain degree of confidence has been developed through these studies related to how process variables and many attributes of machinery configuration will affect granulation but some major challenges still lay ahead related to scalability, variations in the processing regimes related to degree of channel fill and the impact of wetting and granulation of complex powder formulations. This review examines the current literature for wet granulation processes studied in twin screw extrusion machinery, summarizing the influences of operational and system parameters affecting granule properties as well as strives to provide some practical observations to newly interested users of the technique.

  17. Balloon-borne imagery of the solar granulation. II - The lifetime of solar granulation

    Science.gov (United States)

    Mehltretter, J. P.

    1978-01-01

    Phenomenological aspects of the temporal evolution of photospheric granulation are reported as derived from time series of granulation photographs obtained during a flight of a balloon-borne telescope. The distribution of granule lifetime probabilities is determined, and it is found that the data can be represented by an exponential decrease with a 'decay constant' of 5.9 min. The general properties of granular evolution are described along with the way individual granules evolve with time. The most common type of granule is shown to be a medium-sized or small fragment, and it is suggested that all granules are produced by fragmentation of preexisting granules. The relative frequencies of granule destruction by fragmentation, fading, and merging are determined to be 51%, 21%, and 28%, respectively. An average radial velocity of 0.8 km/s is computed for conglomerates with an average diameter of 2.25 arcsec.

  18. Medical image of the week: granulation tissue

    Directory of Open Access Journals (Sweden)

    Ganesh A

    2014-03-01

    Full Text Available A 57 year old woman presented with a tickling sensation in the back of throat and intermittent bleeding from the healing stoma one month after decannulation of her tracheostomy tube. On bronchoscopy a granuloma with surrounding granulation tissue was present in the subglottic space (Figure 1. Argon plasma coagulation (APC was performed to cauterize the granulation tissue (Figure 2. Formation of granulation tissue after tracheostomy is a common complication which can result in tracheal stenosis. APC and electrocautery using flexible bronchoscopy has been shown to safely and effectively remove the granulation tissue.

  19. Granulation of coal fly ash by using different types of granule agents

    Science.gov (United States)

    Agusta, H.; Nisya, F. N.; Iman, R. N.; Bilad, D. B. C.

    2017-05-01

    The use of coal produces about 5% solid pollutant in the form of ash (fly ash and bottom ash). Of the total ash produced, about 10-20% is bottom ash and 80-90% is fly ash. This study was aimed at obtaining a type of adhesive which could be used as a fly granulation material for soil conditioner. The study was conducted at the pilot plant of Surfactant and Bioenergy Research Center (SBRC) LPPM IPB from April to August 2016. The fly ash used in this study was obtained from Kalimantan. A pan granulator was used in fly ash granule making process. Granule agent materials were diluted in the concentration of 5, 10, and 15%. Different types of granule agents, namely SBRC-M, SBRC-T, and SBRC-SC were used. The formed fly ash granules were then analyzed for their physical properties including particle density, fly ash granule pH, fly ash granule durability, and fly ash granule water holding capacity. Results showed that fly ash granules made from 15% of SBRC-M had the highest particle density (0.75 g/cm3). Fly ash granules made with SBRC-M had higher pH (10) than those made by using SBRC-SC adhesive (9.3) and SBRC-T (9). SBRC-T was found as the granule agent material which produced fly ash granules with the highest durability levels on average. In this study, the use of SBRC-M granule agent resulted in higher water holding capacity (WHC) (40.62%) than did SBRC-SC (38.79%) and SBRC-T (36.85%). As a granule agent, compared to SBRC-SC and SBRC-T, SBRC-M could produce fly ash granules with highest particle density, highest pH, good durability, and best water holding capacity.

  20. Distribution of binder in granules produced by means of twin screw granulation

    DEFF Research Database (Denmark)

    Fonteyne, Margot; Fussell, Andrew Luke; Vercruysse, Jurgen

    2014-01-01

    According to the quality by design principle processes may not remain black-boxes and full process understanding is required. The granule size distribution of granules produced via twin screw granulation is often found to be bimodal. The aim of this study was to gain a better understanding...

  1. The paradox of high shear granulation : the formation of non-homogeneous granules

    NARCIS (Netherlands)

    Dries, Kaspar van den

    2004-01-01

    Wet granulation is a process used for the particle size enlargement of primary powders. The mixing of a liquid with the powder glues the primary particles together, which results in the formation of the granules. The mixing action can be performed in many ways, like tumbling (drum granulation),

  2. APPLICATION OF GRANULATION TECHNOLOGY IN VARIOUS INDUSTRIES

    Directory of Open Access Journals (Sweden)

    B. V. YEGOROV

    2017-10-01

    Full Text Available Science and practice proved the high efficiency of granulated mixed fodders. This article presents an overview of granulation technologies for various industries. This article discusses the application of granulation technologies in various industries. The processes of granulation are mass technological processes currently used in a wide range of industries: feed industry, food industry, pharmaceutical industry, fertilizer production, polyethylene, metal production, mining, etc. A wide range of different materials are granulated, including chemicals, iron ore, mixed fodder, and much more. Granulation is a process of pressing or shaping a material in the form of granulesGranulation is widely used in the production of pigments, dyes, synthetic detergents, catalysts, plastics, soot, chemical reagents, etc. The use of granular raw materials in the metallurgical industry helps not only to mechanize processes, but also to increase their intensity by increasing the contact surface of interacting media. Granular fertilizers retain their properties for a long time. In the mining industry, granulation processes are used at the stage of preparation and enrichment of raw materials and release of the finished product.  Particular attention is paid to the feed industry. Granulation allows to ensure stable homogeneity, to improve sanitary and hygienic parameters, to increase nutritional value, to increase the storage period, improve the physical properties. However, despite all the advantages, the existing granulation production lines have a relatively high productivity and, at the same time, a high energy intensity. In this regard, this article proposes a technology for improving the granulation of mixed fodders. According to a preliminary literary review, It should be concluded that improving the technology of the granulation process for feed production is a topical issue in the feed industry today. The development of technology for improving the

  3. Modeling de novo granulation of anaerobic sludge.

    Science.gov (United States)

    Doloman, Anna; Varghese, Honey; Miller, Charles D; Flann, Nicholas S

    2017-07-17

    A unique combination of mechanical, physiochemical and biological forces influences granulation during processes of anaerobic digestion. Understanding this process requires a systems biology approach due to the need to consider not just single-cell metabolic processes, but also the multicellular organization and development of the granule. In this computational experiment, we address the role that physiochemical and biological processes play in granulation and provide a literature-validated working model of anaerobic granule de novo formation. The agent-based model developed in a cDynoMiCs simulation environment successfully demonstrated a de novo granulation in a glucose fed system, with the average specific methanogenic activity of 1.11 ml C H 4 /g biomass and formation of a 0.5 mm mature granule in 33 days. The simulated granules exhibit experimental observations of radial stratification: a central dead core surrounded by methanogens then encased in acidogens. Practical application of the granulation model was assessed on the anaerobic digestion of low-strength wastewater by measuring the changes in methane yield as experimental configuration parameters were systematically searched. In the model, the emergence of multicellular organization of anaerobic granules from randomly mixed population of methanogens and acidogens was observed and validated. The model of anaerobic de novo granulation can be used to predict the morphology of the anaerobic granules in a alternative substrates of interest and to estimate methane potential of the resulting microbial consortia. The study demonstrates a successful integration of a systems biology approach to model multicellular systems with the engineering of an efficient anaerobic digestion system.

  4. Quantitative Raman Spectroscopy Analysis of Polyhydroxyalkanoates Produced by Cupriavidus necator H16

    Czech Academy of Sciences Publication Activity Database

    Samek, Ota; Obruča, S.; Šiler, Martin; Sedláček, P.; Benešová, P.; Kučera, D.; Márová, I.; Ježek, Jan; Bernatová, Silvie; Zemánek, Pavel

    2016-01-01

    Roč. 16, č. 11 (2016), 1808:1-7 ISSN 1424-8220 R&D Projects: GA ČR(CZ) GA15-20645S; GA MŠk(CZ) LO1212; GA MŠk ED0017/01/01 Institutional support: RVO:68081731 Keywords : Raman spectroscopy * Cupriavidus necator H16 * polyhydroxyalkanoates Subject RIV: BH - Optics, Masers, Lasers Impact factor: 2.677, year: 2016

  5. Syngas obtained by microwave pyrolysis of household wastes as feedstock for polyhydroxyalkanoate production in Rhodospirillum rubrum

    OpenAIRE

    Revelles, Olga; Beneroso, Daniel; Menéndez, J. Angel; Arenillas, Ana; García, J. Luis; Prieto, M. Auxiliadora

    2016-01-01

    Summary The massive production of urban and agricultural wastes has promoted a clear need for alternative processes of disposal and waste management. The potential use of municipal solid wastes (MSW) as feedstock for the production of polyhydroxyalkanoates (PHA) by a process known as syngas fermentation is considered herein as an attractive bio‐economic strategy to reduce these wastes. In this work, we have evaluated the potential of Rhodospirillum rubrum as microbial cell factory for the syn...

  6. Processes for producing polyhydroxybutyrate and related polyhydroxyalkanoates in the plastids of higher plants

    Energy Technology Data Exchange (ETDEWEB)

    Somerville, C.R.; Nawrath, C.; Poirier, Y.

    1997-03-11

    The present invention relates to a process for producing poly-D-(-)-3-hydroxybutyric acid (PHB) and related polyhydroxyalkanoates (PHA) in the plastids of plants. The production of PHB is accomplished by genetically transforming plants with modified genes from microorganisms. The genes encode the enzymes required to synthesize PHB from acetyl-CoA or related metabolites and are fused with additional plant sequences for targeting the enzymes to the plastid. 37 figs.

  7. Processes for producing polyhydroxybutyrate and related polyhydroxyalkanoates in the plastids of higher plants

    Science.gov (United States)

    Somerville, Christopher R.; Nawrath, Christiane; Poirier, Yves

    1997-03-11

    The present invention relates to a process for producing poly-D-(-)-3-hydroxybutyric acid (PHB) and related polyhydroxyalkanoates (PHA) in the plastids of plants. The production of PHB is accomplished by genetically transforming plants with modified genes from microorganisms. The genes encode the enzymes required to synthesize PHB from acetyl-CoA or related metabolites and are fused with additional plant sequences for targeting the enzymes to the plastid.

  8. Antibiotics-free stable polyhydroxyalkanoate (PHA) production from carbon dioxide by recombinant cyanobacteria.

    Science.gov (United States)

    Akiyama, Hideo; Okuhata, Hiroshi; Onizuka, Takuo; Kanai, Shozo; Hirano, Masahiko; Tanaka, Satoshi; Sasaki, Ken; Miyasaka, Hitoshi

    2011-12-01

    A practical antibiotics-free plasmid expression system in cyanobacteria was developed by using the complementation of cyanobacterial recA null mutation with the EscherichiacolirecA gene on the plasmid. This system was applied to the production of polyhydroxyalkanoate (PHA), a biodegradable plastic, and the transgenic cyanobacteria stably maintained the pha genes for PHA production in the antibiotics-free medium, and accumulated up to 52% cell dry weight of PHA. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. Slag melt granulation and factors affecting the quality of Granulated slag

    Directory of Open Access Journals (Sweden)

    Володимир Петрович Кравченко

    2015-10-01

    Full Text Available An analysis of the state of slags recycling in foreign countries was carried out. A modern principle was put forward in the article: blast furnace is an apparatus for manufacturing of two basic types of products : cast iron and slag. Granulation, as the primary recycling of slag melt fixes the structure with certain properties at rapid cooling. An analysis of the existing methods of granulation was carried out and factors influencing the quality of granular slag were determined, as well as the ways of obtaining granular slag with the required physical and mechanical characteristics. The main factors of granulated slags quality, employed for manufacturing of binding materials are chemical composition and the structure of fine granulated particles. All wet methods of granulation are characterized by high humidity of granulated slag, its value reaching 24,5%, due to increase in granules’ porosity. Real options for reducing humidity of granulated slag may include: development of the process of granulation, ensuring manufacturing of products with increased density and low content of fine fractions, dehydration of slag in high bunkers and stacks at sufficient soaking time and slag blowdown with a stream moving downwards. Using mechanical granulators and gaseous energy carriers (air for melt’s dispersion is an efficient way of reducing water consumption for granulation (semi-dry or dry methods of granulation. It also makes it possible to reduce r consumption of water, supplied for granulation from 3,0 to 0,7-1,5m3/min. Application of air blast for melt’s dispersion influences its fractional composition and grain shape in the slag: the content of the fraction less than 1,25mm reduces to 49,1%, as compared to conventional 92,8%. The content of spherical grains is with tough surface is 33%, it promoting reduction of residual humidity of granulated slag. Thus, application of air blast for granulation of slags is an efficient way of obtaining high

  10. Coating of waste containing ceramic granules

    International Nuclear Information System (INIS)

    Neumann, W.; Kofler, O.

    1979-01-01

    Simulated high-level waste granules produced by fluidized-bed calcination were overcoated by chemical vapor deposition (CVD) with pyrocarbon and nickel in laboratory-scale experiments. Successful development enables pyrocrbon deposition at temperatures of 600 to 800 0 K. The coated granules have excellent properties for long-term waste storage

  11. Twin screw wet granulation: Binder delivery.

    Science.gov (United States)

    Saleh, Mohammed F; Dhenge, Ranjit M; Cartwright, James J; Hounslow, Michael J; Salman, Agba D

    2015-06-20

    The effects of three ways of binder delivery into the twin screw granulator (TSG) on the residence time, torque, properties of granules (size, shape, strength) and binder distribution were studied. The binder distribution was visualised through the transparent barrel using high speed imaging as well as quantified using offline technique. Furthermore, the effect of binder delivery and the change of screw configuration (conveying elements only and conveying elements with kneading elements) on the surface velocity of granules across the screw channel were investigated using particle image velocimetry (PIV). The binder was delivered in three ways; all solid binder incorporated with powder mixture, 50% of solid binder mixed with powder mixture and 50% mixed with water, all the solid binder dissolved in water. Incorporation of all solid binder with powder mixture resulted in the relatively longer residence time and higher torque, narrower granule size distribution, more spherical granules, weaker big-sized granules, stronger small-sized granules and better binder distribution compared to that in other two ways. The surface velocity of granules showed variation from one screw to another as a result of uneven liquid distribution as well as shown a reduction while introducing the kneading elements into the screw configuration. Copyright © 2015. Published by Elsevier B.V.

  12. The effect of the amount of binder liquid on the granulation mechanisms and structure of microcrystalline cellulose granules prepared by high shear granulation

    NARCIS (Netherlands)

    Bouwman, A M; Henstra, M J; Westerman, D; Chung, J T; Zhang, Z; Ingram, A; Seville, J P K; Frijlink, H W

    2005-01-01

    The structure of granules changes during the high shear granulation process. The purpose of this research was to investigate the effect of the amount of binder liquid on the structure of the granules and the structural changes which occur during the granulation process, using microcrystalline

  13. Granulation effects on the radon emanation rate.

    Science.gov (United States)

    Bikit, I; Mrda, D; Grujic, S; Kozmidis-Luburic, U

    2011-05-01

    The radon emanation and the granulation effect on the emanation rate of several building materials (ceramic plates, sand, red brick and siporex brick) with different (226)Ra concentrations were investigated. A ball mill was used to achieve different granulations of the materials. The particle size distributions were determined by a particle size analyser (Mastersizer 2000). The increase in the (222)Rn concentration inside a closed chamber (volume ≈5.4 × 10(-3) m(3)) due to emanation from each material with different granulations was measured by an alpha spectrometer (RAD7). Thus, time-dependent curves for radon concentrations were obtained. The highest radon emanation coefficient (27 %) was obtained for the siporex sample with the smallest grain size (0.34 µm). For the ceramic pads, the granulation effect was negligible and the emanation coefficient was very low (∼0.4 %). The strongest influence of granulation on the radon emanation rate was found for the siporex brick sample.

  14. Exploration of Global Trend on Biomedical Application of Polyhydroxyalkanoate (PHA): A Patent Survey.

    Science.gov (United States)

    Ponnaiah, Paulraj; Vnoothenei, Nagiah; Chandramohan, Muruganandham; Thevarkattil, Mohamed Javad Pazhayakath

    2018-01-30

    Polyhydroxyalkanoates are bio-based, biodegradable naturally occurring polymers produced by a wide range of organisms, from bacteria to higher mammals. The properties and biocompatibility of PHA make it possible for a wide spectrum of applications. In this context, we analyze the potential applications of PHA in biomedical science by exploring the global trend through the patent survey. The survey suggests that PHA is an attractive candidate in such a way that their applications are widely distributed in the medical industry, drug delivery system, dental material, tissue engineering, packaging material as well as other useful products. In our present study, we explored patents associated with various biomedical applications of polyhydroxyalkanoates. Patent databases of European Patent Office, United States Patent and Trademark Office and World Intellectual Property Organization were mined. We developed an intensive exploration approach to eliminate overlapping patents and sort out significant patents. We demarcated the keywords and search criterions and established search patterns for the database request. We retrieved documents within the recent 6 years, 2010 to 2016 and sort out the collected data stepwise to gather the most appropriate documents in patent families for further scrutiny. By this approach, we retrieved 23,368 patent documents from all the three databases and the patent titles were further analyzed for the relevance of polyhydroxyalkanoates in biomedical applications. This ensued in the documentation of approximately 226 significant patents associated with biomedical applications of polyhydroxyalkanoates and the information was classified into six major groups. Polyhydroxyalkanoates has been patented in such a way that their applications are widely distributed in the medical industry, drug delivery system, dental material, tissue engineering, packaging material as well as other useful products. There are many avenues through which PHA & PHB could be

  15. THE STUDY OF THE KINETIC OF NATURAL ZEOLITE GRANULES GROWTH AT DIFFERENT WAYS OF GRANULATION

    Directory of Open Access Journals (Sweden)

    Rybachuk VD

    2016-12-01

    Full Text Available Introduction. Active substances and excipients used in the manufacture of medicines in tablet form, in most cases, have poor technological properties. This fact determines the need for prior granulation of mass before compression. Granulators of various sizes and designs, running on different modes, made the formation, growth and consolidation of the powder particles that lead to obtain pellets of different shapes and sizes. From the literature it is known that granulation leads to two forms of granules: isodiametric and nonisodiametric. The first group of particles forms has globular shape with a smooth surface and the proportion in which the length, thickness and height are about the same. They are usually made by fluidized bed granulation, spray drying, pelletizing and granulation in dragee pan. Granules of nonisodiametric form in which length is several times the width and height are made mostly by extrusion and compacting. The geometrical parameters of obtained granules are affected by the properties of raw materials, the granulation modes, type and amount of added humidifier and so on. The shape and size of granules, from a technological point of view, are the key factors that contribute, except organoleptic characteristics of the product, its technological properties such as particle size distribution, bulk volume, the ability of the material to shrinkage, porosity, fluidity, mechanical strength and so on. Properly selected for specific conditions granulation method is able to provide the finished product with the specified technological parameters depending on the needs. The aim of this work was to study the effect of granulation method and its conditions on the kinetics of growth of the natural zeolite granules and some quality characteristics of obtained granules. Material & methods. As objects of study served the natural zeolite pellets produced using 3%, 5%, 7% and 10% potato starch paste and solution of polyvinylpyrrolidone (PVP

  16. Impact of screw configuration on the particle size distribution of granules produced by twin screw granulation.

    Science.gov (United States)

    Vercruysse, J; Burggraeve, A; Fonteyne, M; Cappuyns, P; Delaet, U; Van Assche, I; De Beer, T; Remon, J P; Vervaet, C

    2015-02-01

    Twin screw granulation (TSG) has been reported by different research groups as an attractive technology for continuous wet granulation. However, in contrast to fluidized bed granulation, granules produced via this technique typically have a wide and multimodal particle size distribution (PSD), resulting in suboptimal flow properties. The aim of the current study was to evaluate the impact of granulator screw configuration on the PSD of granules produced by TSG. Experiments were performed using a 25 mm co-rotating twin screw granulator, being part of the ConsiGma™-25 system (a fully continuous from-powder-to-tablet manufacturing line from GEA Pharma Systems). Besides the screw elements conventionally used for TSG (conveying and kneading elements), alternative designs of screw elements (tooth-mixing-elements (TME), screw mixing elements (SME) and cutters) were investigated using an α-lactose monohydrate formulation granulated with distilled water. Granulation with only conveying elements resulted in wide and multimodal PSD. Using kneading elements, the width of the PSD could be partially narrowed and the liquid distribution was more homogeneous. However, still a significant fraction of oversized agglomerates was obtained. Implementing additional kneading elements or cutters in the final section of the screw configuration was not beneficial. Furthermore, granulation with only TME or SME had limited impact on the width of the PSD. Promising results were obtained by combining kneading elements with SME, as for these configurations the PSD was narrower and shifted to the size fractions suitable for tableting. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Granular Data Description: Designing Ellipsoidal Information Granules.

    Science.gov (United States)

    Zhu, Xiubin; Pedrycz, Witold; Li, Zhiwu

    2017-12-01

    Granular computing (GrC) has emerged as a unified conceptual and processing framework. Information granules are fundamental constructs that permeate concepts and models of GrC. This paper is concerned with a design of a collection of meaningful, easily interpretable ellipsoidal information granules with the use of the principle of justifiable granularity by taking into consideration reconstruction abilities of the designed information granules. The principle of justifiable granularity supports designing of information granules based on numeric or granular evidence, and aims to achieve a compromise between justifiability and specificity of the information granules to be constructed. A two-stage development strategy behind the construction of justifiable information granules is considered. First, a collection of numeric prototypes is determined with the use of fuzzy clustering. Second, the lengths of the semi-axes of ellipsoidal information granules to be formed around such prototypes are optimized. Two optimization criteria are introduced and studied. Experimental studies involving synthetic data set and data sets coming from the machine learning repository are reported.

  18. Analysis of the release process of phenylpropanolamine hydrochloride from ethylcellulose matrix granules V. Release properties of ethylcellulose layered matrix granules.

    Science.gov (United States)

    Fukui, Atsuko; Fujii, Ryuta; Yonezawa, Yorinobu; Sunada, Hisakazu

    2008-04-01

    In the pharmaceutical preparation of a controlled release drug, it is very important and necessary to understand the release properties. In previous papers, a combination of the square-root time law and cube-root law equations was confirmed to be a useful equation for qualitative treatment. It was also confirmed that the combination equation could analyze the release properties of layered granules as well as matrix granules. The drug release property from layered granules is different from that of matrix granules. A time lag occurs before release, and the entire release property of layered granules was analyzed using the combination of the square-root time law and cube-root law equations. It is considered that the analysis method is very useful and efficient for both matrix and layered granules. Comparing the granulation methods, it is easier to control the manufacturing process by tumbling granulation (method B) than by tumbling-fluidized bed granulation (method C). Ethylcellulose (EC) layered granulation by a fluidized bed granulator might be convenient for the preparation of controlled release dosage forms as compared with a tumbling granulator, because the layered granules prepared by the fluidized bed granulator can granulate and dry at the same time. The time required for drying by the fluidized bed granulator is shorter than that by the tumbling granulator, so the fluidized bed granulator is convenient for preparation of granules in handling and shorter processing time than the tumbling granulator. It was also suggested that the EC layered granules prepared by the fluidized bed granulator were suitable for a controlled release system as well as the EC matrix granules.

  19. High-temperature superconductivity of granulated metals

    CERN Document Server

    Mejlikhov, E Z

    2001-01-01

    Only the area of relatively low temperatures was traditionally considered in the theoretical ands experimental studies on the nanocomposites (granulated metals) conductivity, related to the intergranular electrons tunneling. The conductivity temperature dependence in this mode is exponential. However, according to the experiment the character of the nanocomposites conductivity at higher temperatures essentially changes. The model, relating the peculiarities of the granulated metals conductivity at high temperatures, to the involvement of the multicharged granules in this process under the conditions of high spread of their sizes, is proposed. The model conclusions are in agreement with the experiment

  20. Fluid bed granulation of a poorly water soluble, low density, micronized drug: comparison with high shear granulation.

    Science.gov (United States)

    Gao, Julia Z H; Jain, A; Motheram, R; Gray, D B; Hussain, M A

    2002-04-26

    A 2(4-1) fractional factorial design was used to evaluate the effect of various process variables in fluid bed granulation, on the physico-chemical properties of granule and tablet containing a high dose, poorly water soluble, low density, and micronized drug. The process variables studied were inlet air temperature, inlet air flow, spray rate of the binder solution, and atomization air pressure. Tablets with identical composition, weight, size and hardness were also manufactured in a high shear granulator and their physical properties were determined and compared with those produced by the fluidized bed granulation method. Except for the granule size distribution, other physical properties of granulations and tablets produced in a fluid bed granulator are independent of the selected process variables within the study range. Both atomization air pressure and spray rate of the binder solution had strong impact on granule size distribution. Irrespective of the process conditions used in the fluid bed granulation, granules from this process were more porous, less dense and more compressible than the granules from the high shear granulation process. Comparable tablet dissolution rates to those prepared by the optimized high shear granulation method can be achieved by selecting the appropriate process conditions in fluid bed granulation. These results suggest that wet granulation tablets of a high dose, poorly water soluble, low density, micronized drug can be manufactured using a fluidized bed granulation method, with comparable tablet dissolution rates to those produced with an optimized high shear granulation method.

  1. High-shear granulation as a manufacturing method for cocrystal granules

    DEFF Research Database (Denmark)

    Rehder, Sönke; Christensen, Niels Peter Aae; Rantanen, Jukka

    2013-01-01

    influenced by the excipients, since in presence of calcium hydrogenphosphate, the poorly water-soluble salt calcium tartrate monohydrate was formed at high relative humidity. Interestingly, compactability was increased by cocrystal formation compared to that of the reference granules (piracetam......Cocrystal formation allows the tailoring of physicochemical as well as of mechanical properties of an API. However, there is a lack of large-scale manufacturing methods of cocrystals. Therefore, the objective of this work was to examine the suitability of high-shear wet granulation...... as a manufacturing method for cocrystal granules on a batch scale. Furthermore, the cocrystal granules were characterized regarding their mechanical properties as well as their dissolution behavior. High-shear wet granulation was found to be a feasible manufacturing method for cocrystal granules. Cocrystal formation...

  2. Wet granulation in rotary processor and fluid bed: Comparison of granule and tablet properties

    OpenAIRE

    Kristensen, Jakob; Hansen, Vibeke Wallaert

    2006-01-01

    The aim of the present study was to investigate and compare granule and tablet properties of granules prepared by wet granulation in a rotary processor or a conventional fluid bed. For this purpose the working range of selected process variables was determined and a factorial study with 3 factors (equipment type, filler type, and liquid addition rate) and 1 covariate (fluidizing air flow rate) was performed. Two grades of calcium carbonate with different size and shape characteristics were ap...

  3. Bone growth response with porous hydroxyapatite granules in a

    Indian Academy of Sciences (India)

    Bone growth with porous hydroxyapatite granules 147 granules. Yet few gaps still persisted between the new bone and the granules. Morphologically the granules did not show any signs of degradation. Formation of the. Haversian system and the maturation of woven bone were observed (figure 7b). 12 weeks: The defect ...

  4. A murine model of subglottic granulation.

    Science.gov (United States)

    Ghosh, A; Leahy, K P; Singhal, S; Einhorn, E; Howlett, P; Cohen, N A; Mirza, N

    2016-04-01

    This study aimed to develop a functional model of subglottic stenosis by inducing direct airway irritation in transplanted mouse laryngotracheal complexes. Laryngotracheal complexes from C57BL/6 mice were harvested and divided into three groups: uninjured, mechanically injured and chemically injured. Donor laryngotracheal complexes from each group were placed in dorsal subcutaneous pockets of recipient mice. Each week, the transplanted laryngotracheal complexes were harvested, and tissues were fixed, sectioned, and stained with haematoxylin and eosin. Representative slides were reviewed by a blinded pathologist, to determine the formation of granulation tissue, and graded as to the degree of granulation formation. Direct airway irritation induced granulation tissue formation under the disrupted epithelium of airway mucosa; this was seen as early as two weeks after chemical injury. Results indicate that granulation tissue formation in a murine model may be an efficient tool for investigating the development and treatment of subglottic stenosis.

  5. The quorum-sensing effect of aerobic granules on bacterial adhesion, biofilm formation, and sludge granulation.

    Science.gov (United States)

    Ren, Ting-ting; Yu, Han-qing; Li, Xiao-yan

    2010-10-01

    Quorum sensing (QS) through signal chemical molecules is known to be essential to bacterial adhesion and biofilm formation. In this study, the QS ability of aerobic granules--a special form of biofilms used for biological wastewater treatment--was investigated and compared with that of conventional activated sludge flocs. A novel sectional membrane bioreactor was used together with a flow-cell to evaluate the possible influence of signal chemicals produced by the source sludge on the growth mode of bacterial cells. The results demonstrate the apparent production of QS chemicals from granules and its impact on initial cell attachment and granule formation. When granules were used as the signal-producing biomass, the attached-growth mode was dominant for the free cells, and the biofilm formation rate in the flow-cell was about ten times faster than in cases which used activated sludge as the signal source biomass. In addition, the intracellular extract from mature granules significantly accelerated the sludge granulation process. It is argued that the production and expression of QS signal chemicals from granules and granule precursors might have induced the gene expression of bacteria in suspension for attached growth rather than suspended growth, leading to granule formation and its stable structure.

  6. Process analysis of fluidized bed granulation.

    Science.gov (United States)

    Rantanen, J; Jørgensen, A; Räsänen, E; Luukkonen, P; Airaksinen, S; Raiman, J; Hänninen, K; Antikainen, O; Yliruusi, J

    2001-10-17

    This study assesses the fluidized bed granulation process for the optimization of a model formulation using in-line near-infrared (NIR) spectroscopy for moisture determination. The granulation process was analyzed using an automated granulator and optimization of the verapamil hydrochloride formulation was performed using a mixture design. The NIR setup with a fixed wavelength detector was applied for moisture measurement. Information from other process measurements, temperature difference between process inlet air and granules (T(diff)), and water content of process air (AH), was also analyzed. The application of in-line NIR provided information related to the amount of water throughout the whole granulation process. This information combined with trend charts of T(diff) and AH enabled the analysis of the different process phases. By this means, we can obtain in-line documentation from all the steps of the processing. The choice of the excipient affected the nature of the solid-water interactions; this resulted in varying process times. NIR moisture measurement combined with temperature and humidity measurements provides a tool for the control of water during fluid bed granulation.

  7. Specific character of bacterial biodegradation of polyhydroxyalkanoates with different chemical structure in soil.

    Science.gov (United States)

    Prudnikova, S V; Vinogradova, O N; Trusova, M Y

    2017-03-01

    The study addresses the influence of the physicochemical properties of the reserve cellular macromolecules (polyhydroxyalkanoates, PHA) with different chemical composition on their biodegradation in the agro-transformed field soil of the Siberian region (Krasnoyarsk Territory, Russia). It was shown that the degradation of the PHA samples depends on the degree of polymer crystallinity (C x ). For the first time, it was shown that the range of PHA-degrading microorganisms differs for each of PHA types. The study defines the primary degraders specific to each PHA type and common to all types of examined polymers.

  8. Involvement of polyhydroxyalkanoates in stress resistance of microbial cells: Biotechnological consequences and applications.

    Science.gov (United States)

    Obruca, Stanislav; Sedlacek, Petr; Koller, Martin; Kucera, Dan; Pernicova, Iva

    2017-12-14

    Polyhydroxyalkanoates (PHA) are polyesters accumulated by numerous prokaryotes as storage materials; they attract attention as "green" alternatives to petrochemical plastics. Recent research has demonstrated that their biological role goes beyong their storage function, since they presence in cytoplasm enhances stress resistance of microorganisms. To address these complex functions, this review summarizes the protective effects of PHA for microrganisms; the involvement of PHA in stress resistance is discussed also from a praxis-oriented perspective. The review discourses the controlled application of stress to improve PHA productivity. Also the manifold advantages of using stress adapted microbes - extremophiles as PHA producers are discussed. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Synthetic routes to degradable copolymers deriving from the biosynthesized polyhydroxyalkanoates: A mini review

    Directory of Open Access Journals (Sweden)

    Y. Ke

    2016-01-01

    Full Text Available Polyhydroxyalkanoates are a family of natural polyesters being produced as intracellular carbon and energy reserves by a wide variety of microorganisms. They have developed rapidly in both research and development efforts globally in the last 15 years. Till now, over 100 different types of PHAs have been successfully biosynthesized using both genetic engineering and fermentation techniques. Their unique biodegradable, biocompatible and thermoplastic characteristics make PHAs promising candidates for the commodity and biomedical applications. This review focused on the chemical synthesis of the derivatives of the biosynthesized PHAs.

  10. Detection of component segregation in granules manufactured by high shear granulation with over-granulation conditions using near-infrared chemical imaging.

    Science.gov (United States)

    Koide, Tatsuo; Nagato, Takuya; Kanou, Yoshiyuki; Matsui, Kou; Natsuyama, Susumu; Kawanishi, Toru; Hiyama, Yukio

    2013-01-30

    The objective of this study was to evaluate the high shear granulation process using near-infrared (NIR) chemical imaging technique and to make the findings available for pharmaceutical development. We prepared granules and tablets made under appropriate- and over-granulation conditions with high shear granulation and observed these granules and tablets using NIR chemical imaging system. We found an interesting phenomenon: lactose agglomeration and segregation of ingredients occurred in experimental tablets when over-granulation conditions, including greater impeller rotation speeds and longer granulation times, were employed. Granules prepared using over-granulation conditions were larger and had progressed to the consolidation stage; segregation between ethenzamide and lactose occurred within larger granules. The segregation observed here is not detectable using conventional analytical technologies such as high pressure liquid chromatography (HPLC) because the content of the granules remained uniform despite the segregation. Therefore, granule visualization using NIR chemical imaging is an effective method for investigating and evaluating the granulation process. Copyright © 2012 Elsevier B.V. All rights reserved.

  11. Wet granulation in rotary processor and fluid bed: Comparison of granule and tablet properties.

    Science.gov (United States)

    Kristensen, Jakob; Hansen, Vibeke Wallaert

    2006-03-01

    The aim of the present study was to investigate and compare granule and tablet properties of granules prepared by wet granulation in a rotary processor or a conventional fluid bed. For this purpose the working range of selected process variables was determined and a factorial study with 3 factors (equipment type, filler type, and liquid addition rate) and 1 covariate (fluidizing air flow rate) was performed. Two grades of calcium carbonate with different size and shape characteristics were applied, and the liquid addition and fluidizing air flow rates were investigated in the widest possible range. Dry mixtures of microcrystalline cellulose, polyvinyl povidone, calcium carbonate, and riboflavin, in a 10∶5∶84∶1 ratio, were granulated in both types of equipment. The granulation end point was determined manually in the fluid bed and by torque measurements in the rotary processor. The filler type had a more pronounced effect on granular properties in the fluid bed, but the rotary processor showed a higher dependency on the investigated process variables. The rotary processor gave rise to more dense granules with better flow properties, but the fluid bed granules had slightly better compressional properties. Furthermore, the distribution of a low-dose drug was found to be more homogeneous in the rotary processor granules and tablets. Generally, wet granulation in a rotary processor was found to be a good alternative to conventional fluid bed granulation, especially when cohesive powders with poor flow properties or formulations with low drug content are to be granulated by a fluidizing air technique.

  12. [Air drying process of granules and characteristics of their structure].

    Science.gov (United States)

    Li, Zhi-Hua; Zhang, Yu-Rong; Wang, Xiao-Chang

    2011-08-01

    Filamentous granules were cultivated using a sequencing batch reactor. The yellowish bacteria dominated granules, black fungi dominated granules and Microthrix parvicella dominated white smooth granules occurred in the reactor on the day 18, 23 and 27 respectively. Distribution of surface related free water and capillary water were analysis using air drying method. It was found that the surface related free water in the black and white filamentous granules was 79% and 83%, respectively, and that in the conventional bacteria granules were 64%, suggesting that the surface area opening ratio of surface and porosity decreased in the order of white, black and yellowish granules. According to the air drying rate in different phases of granules, it can be inferred that the white and black filamentous granules could rapidly exchange the substrates on the surface and consequently prone to be big and loose, which discourages the stability of granules. Additionally, the section image showed that filamentous granules were more porous than the black bacteria granules. Filamentous granules exhibited encouraging COD and nitrogen removal efficiencies. The black and white filamentous granules showed higher bioactivity with the oxygen up-take rate (SOUR) of 1.29 and 1.26 fold of the conventional yellowish granules.

  13. [Study on fluidized melt-granulation. I. Examination of the factors on the granulation].

    Science.gov (United States)

    Haramiishi, Y; Kitazawa, Y; Sakai, M; Kataoka, K

    1991-09-01

    The purpose of this study is to develop a new granulation method by using a fluidized-bed granulator, which requires a nucleus with a low melting point as a binder. This method was named as fluidized melt-granulation. The technique is very simple and useful. In this paper, the granulation mechanism and the effect of the physico-chemical properties of raw materials on the growth of the granules were investigated. The results were as follows: (1) The mixture of the nucleus and the other powder particles was heated up to the melting point of the nucleus by hot inlet air, immediately resulting in the generation of the adhesion of the powders on the melted nucleus. The granules grew as the melted material immersed into the void space among the adhered particles. (2) The lower the viscosity of the melted nucleus was, the faster the granule grew. (3) The shape and the size of the nucleus affected those of the products. (4) The optimum mixing ratio between the nucleus and the granulated materials existed and it depended on the ratio between the surface areas of these materials.

  14. Eosinophil secretion of granule-derived cytokines

    Directory of Open Access Journals (Sweden)

    Lisa A Spencer

    2014-10-01

    Full Text Available Eosinophils are tissue-dwelling leukocytes, present in the thymus, and gastrointestinal and genitourinary tracts of healthy individuals at baseline, and recruited, often in large numbers, to allergic inflammatory foci and sites of active tissue repair. The biological significance of eosinophils is vast and varied. In health, eosinophils support uterine and mammary gland development, and maintain bone marrow plasma cells and adipose tissue alternatively activated macrophages, while in response to tissue insult eosinophils function as inflammatory effector cells, and, in the wake of an inflammatory response, promote tissue regeneration and wound healing. One common mechanism driving many of the diverse eosinophil functions is the regulated and differential secretion of a vast array of eosinophil-derived cytokines. Eosinophils are distinguished from most other leukocytes in that many, if not all, of the over three dozen eosinophil-derived cytokines are pre-synthesized and stored within intracellular granules, poised for very rapid, stimulus-induced secretion. Eosinophils engaged in cytokine secretion in situ utilize distinct pathways of cytokine release that include: classical exocytosis, whereby granules themselves fuse with the plasma membrane and release their entire contents extracellularly; piecemeal degranulation, whereby granule-derived cytokines are selectively mobilized into vesicles that emerge from granules, traverse the cytoplasm and fuse with the plasma membrane to release discrete packets of cytokines; and eosinophil cytolysis, whereby intact granules are extruded from eosinophils, and deposited within tissues. In this latter scenario, extracellular granules can themselves function as stimulus-responsive secretory-competent organelles within the tissue. Here we review the distinctive processes of differential secretion of eosinophil granule-derived cytokines.

  15. Investigation of Physicochemical Drug Properties to Prepare Fine Globular Granules Composed of Only Drug Substance in Fluidized Bed Rotor Granulation.

    Science.gov (United States)

    Mise, Ryohei; Iwao, Yasunori; Kimura, Shin-Ichiro; Osugi, Yukiko; Noguchi, Shuji; Itai, Shigeru

    2015-01-01

    The effect of some drug properties (wettability and particle size distribution) on granule properties (mean particle size, particle size distribution, sphericity, and granule strength) were investigated in a high (>97%) drug-loading formulation using fluidized bed rotor granulation. Three drugs: acetaminophen (APAP); ibuprofen (IBU); and ethenzamide (ETZ) were used as model drugs based on their differences in wettability and particle size distribution. Granules with mean particle sizes of 100-200 µm and a narrow particle size distribution (PSD) could be prepared regardless of the drug used. IBU and ETZ granules showed a higher sphericity than APAP granules, while APAP and ETZ granules exhibited higher granule strength than IBU. The relationship between drug and granule properties suggested that the wettability and the PSD of the drugs were critical parameters affecting sphericity and granule strength, respectively. Furthermore, the dissolution profiles of granules prepared with poorly water-soluble drugs (IBU and ETZ) showed a rapid release (80% release in 20 min) because of the improved wettability with granulation. The present study demonstrated for the first time that fluidized bed rotor granulation can prepare high drug-loaded (>97%) globular granules with a mean particle size of less than 200 µm and the relationship between physicochemical drug properties and the properties of the granules obtained could be readily determined, indicating the potential for further application of this methodology to various drugs.

  16. Pseudomonas putida KT2442 as a platform for the biosynthesis of polyhydroxyalkanoates with adjustable monomer contents and compositions

    DEFF Research Database (Denmark)

    Tripathi, Lakshmi; Wu, Lin-Ping; Dechuan, Meng

    2013-01-01

    The β-oxidation weakened Pseudomonas putida were established as a platform for the production of polyhydroxyalkanoates (PHA) with adjustable monomer compositions and micro-structures. When mutant P. putida KTOYO6ΔC (phaPCJA.c) was cultivated on mixtures of sodium butyrate and sodium hexanoate (C4...

  17. Differential sensitivity of polyhydroxyalkanoate producing bacteria to fermentation inhibitors and comparison of polyhydroxybutyrate production from Burkholderia cepacia and Pseudomonas pseudoflava

    Science.gov (United States)

    Diane Dietrich; Barbara Illman; Casey Crooks

    2013-01-01

    The aim of this study is determine the relative sensitivity of a panel of seven polyhydroxyalkanoate producing bacteria to a panel of seven lignocellulosic-derived fermentation inhibitors representing aliphatic acids, furans and phenolics. A further aim was to measure the polyhydroxybutyrate production of select organisms on lignocellulosic-derived monosaccharides...

  18. Inexpensive, renewable substrates for the fermentative biosynthesis of bacterial poly(hydroxyalkanoate)s with controlled monomeric compositions

    Science.gov (United States)

    Poly(hydroxyalkanoate)s (PHA’s) are well-known bacterial polyesters produced by many bacteria under nutrient-deficient conditions. While many PHA’s demonstrate comparable properties to the more popular petrochemical polymers, PHA applications are inhibited by high production costs. In an effort to r...

  19. Cloning and heterologous expression of a novel subgroup of class IV polyhydroxyalkanoate synthase genes from the genus Bacillus.

    Science.gov (United States)

    Mizuno, Kouhei; Kihara, Takahiro; Tsuge, Takeharu; Lundgren, Benjamin R; Sarwar, Zaara; Pinto, Atahualpa; Nomura, Christopher T

    2017-01-01

    Many microorganisms harbor genes necessary to synthesize biodegradable plastics known as polyhydroxyalkanoates (PHAs). We surveyed a genomic database and discovered a new cluster of class IV PHA synthase genes (phaRC). These genes are different in sequence and operon structure from any previously reported PHA synthase. The newly discovered PhaRC synthase was demonstrated to produce PHAs in recombinant Escherichia coli.

  20. Comb-like temperature-responsive polyhydroxyalkanoate-graft-poly(2-dimethylamino-ethylmethacrylate) for controllable protein adsorption

    DEFF Research Database (Denmark)

    Yao, Hui; Wei, Daixu; Che, Xuemei

    2016-01-01

    Polyhydroxyalkanoates (PHA) are a family of diverse biopolyesters produced by many bacteria grown on sustainable bio-resources such as glucose or fatty acids. A PHA copolymer P(3HDD-co-3H9D) consisting of 3-hydroxydodecanoate (3HDD) and 3-hydroxy-9-decenoate (3H9D) was synthesized by the engineer...

  1. Granule fraction inhomogeneity of calcium carbonate/sorbitol in roller compacted granules

    DEFF Research Database (Denmark)

    Bacher, Charlotte; Olsen, P.M.; Bertelsen, P.

    2008-01-01

    The granule fraction inhomogeneity of roller compacted granules was examined on mixtures of three different morphologic forms of calcium carbonate and three particle sizes of sorbitol. The granule fraction inhomogeneity was determined by the distribution of the calcium carbonate in each of the 10...... size fractions between 0 and 2000 µm and by calculating the demixing potential. Significant inhomogeneous occurrence of calcium carbonate in the size fractions was demonstrated, depending mostly on the particles sizes of sorbitol but also on the morphological forms of calcium carbonate....... The heterogeneous distribution of calcium carbonate was related to the decrease in compactibility of roller compacted granules in comparison to the ungranulated materials. This phenomenon was explained by a mechanism where fracturing of the ribbon during granulation occurred at the weakest interparticulate bonds...

  2. Production of polyhydroxyalkanoates from spent coffee grounds oil obtained by supercritical fluid extraction technology.

    Science.gov (United States)

    Cruz, Madalena V; Paiva, Alexandre; Lisboa, Pedro; Freitas, Filomena; Alves, Vítor D; Simões, Pedro; Barreiros, Susana; Reis, Maria A M

    2014-04-01

    Spent coffee grounds (SCG) oil was obtained by supercritical carbon dioxide (scCO2) extraction in a pilot plant apparatus, with an oil extraction yield of 90% at a 35kgkg(-1) CO2/SCG ratio. Cupriavidus necator DSM 428 was cultivated in 2L bioreactor using extracted SCG oil as sole carbon source for production of polyhydroxyalkanoates. The culture reached a cell dry weight of 16.7gL(-1) with a polymer content of 78.4% (w/w). The volumetric polymer productivity and oil yield were 4.7gL(-1)day(-1) and 0.77gg(-1), respectively. The polymer produced was a homopolymer of 3-hydroxybutyrate with an average molecular weight of 2.34×10(5) and a polydispersity index of 1.2. The polymer exhibited brittle behaviour, with very low elongation at break (1.3%), tensile strength at break of 16MPa and Young's Modulus of 1.0GPa. Results show that SCG can be a bioresource for polyhydroxyalkanoates production with interesting properties. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Statistical media design for efficient polyhydroxyalkanoate production in Pseudomonas sp. MNNG-S.

    Science.gov (United States)

    Saranya, V; Rajeswari, V; Abirami, P; Poornimakkani, K; Suguna, P; Shenbagarathai, R

    2016-07-03

    Polyhydroxyalkanoate (PHA) is a promising polymer for various biomedical applications. There is a high need to improve the production rate to achieve end use. When a cost-effective production was carried out with cheaper agricultural residues like molasses, traces of toxins were incorporated into the polymer, which makes it unfit for biomedical applications. On the other hand, there is an increase in the popularity of using chemically defined media for the production of compounds with biomedical applications. However, these media do not exhibit favorable characteristics such as efficient utilization at large scale compared to complex media. This article aims to determine the specific nutritional requirement of Pseudomonas sp. MNNG-S for efficient production of polyhydroxyalkanoate. Response surface methodology (RSM) was used in this study to statistically design for PHA production based on the interactive effect of five significant variables (sucrose; potassium dihydrogen phosphate; ammonium sulfate; magnesium sulfate; trace elements). The interactive effects of sucrose with ammonium sulfate, ammonium sulfate with combined potassium phosphate, and trace element with magnesium sulfate were found to be significant (p < .001). The optimization approach adapted in this study increased the PHA production more than fourfold (from 0.85 g L(-1) to 4.56 g L(-1)).

  4. Improvements of condenser performance with granulate balls

    International Nuclear Information System (INIS)

    Bratthaell, L.

    1986-05-01

    At the nuclear power plant Oskarshamn has during time Nov 1983 - Apr 1985 test series been done to investigate the improvements of condensor performance with granulate balls. This type of ball is a normal sponge rubber ball coated with granulated plastic material. This material is, different from carborundum and pumice not abrasive to the tube material. The test results show that granulate balls give an improvement of the overall heat transfer coefficient of 5-7 percent compared to continous cleaning with normal sponge rubber balls. Granulate balls remove the utmost thin coating of organic material that the spong rubber balls are not able to remove and a practically metallic clean surface is established. This has been verified by laboratory inspection of tubes withdrawn from the tube bundle and site inspections of the condenser. When the condenser is cleaned by granulate balls during a period of about three days it is possible to keep the performance at a high level for a long time with continous cleaning with normal sponge rubber balls. After about three days the plastic layer on the balls is practically worned out. The balls have during that time fulfilled their function. The improvement in condenser temperature is 1,0-1,5 degree C. For the 02-turbine this means additional delivered energy of about 15000 MWh per year. (author)

  5. Microbial selection pressure is not a prerequisite for granulation: dynamic granulation and microbial community study in a complete mixing bioreactor.

    Science.gov (United States)

    Zhou, Dandan; Niu, Shu; Xiong, Yongjiao; Yang, Yang; Dong, Shuangshi

    2014-06-01

    Microbial selection pressure is traditionally supposed as a prerequisite for aerobic granulation. This work gives a different insight on this issue. Fluorescent microspheres were used to label the flocculent biomass granulation for a period of 47days in a continuous-flow bioreactor. Analysis of the distribution of fluorescent microspheres in granules revealed that the terminal phase of granulation is in a dynamic steady state, where bioflocs detach, collide and aggregate randomly. This revealed that the un-granulated biomass was the result of the dynamic aggregation and breakage, rather than the microbial species unable to be granulated. Furthermore, denaturing gradient gel electrophoresis (DGGE) profile and UPGMA dendrogram results showed similar microbial communities during the granulation. To sum up, microbial selection pressure was not a prerequisite for aerobic granulation from both of the dynamic granulation steps and molecular biology aspects. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. A Survey of Sludge Granulation Theories Under Anaerobic Conditions

    Directory of Open Access Journals (Sweden)

    Jalal Shayegan

    2011-01-01

    Full Text Available This paper surveys the different theories developed on anaerobic sludge granulation. The theories are generally categorized as physical, microbial, and thermodynamic approaches. In the physical approach to the granulation process, granulation is described by such physical conditions of the reactor as upflow velocity of gas and liquid streams, suspended solids in the effluent flow, and excess sludge removal. Microbial theories are based on the properties of specific organisms and on granule properties (granule structure and its microbiology. The thermodynamic approach studies such factors as hydrophobia, electrophoretic mobility, effective energy in granule adhesion process, and effect of proton transferring activities on bacterial membrane surfaces.

  7. The combined effect of wet granulation process parameters and dried granule moisture content on tablet quality attributes.

    Science.gov (United States)

    Gabbott, Ian P; Al Husban, Farhan; Reynolds, Gavin K

    2016-09-01

    A pharmaceutical compound was used to study the effect of batch wet granulation process parameters in combination with the residual moisture content remaining after drying on granule and tablet quality attributes. The effect of three batch wet granulation process parameters was evaluated using a multivariate experimental design, with a novel constrained design space. Batches were characterised for moisture content, granule density, crushing strength, porosity, disintegration time and dissolution. Mechanisms of the effect of the process parameters on the granule and tablet quality attributes are proposed. Water quantity added during granulation showed a significant effect on granule density and tablet dissolution rate. Mixing time showed a significant effect on tablet crushing strength, and mixing speed showed a significant effect on the distribution of tablet crushing strengths obtained. The residual moisture content remaining after granule drying showed a significant effect on tablet crushing strength. The effect of moisture on tablet tensile strength has been reported before, but not in combination with granulation parameters and granule properties, and the impact on tablet dissolution was not assessed. Correlations between the energy input during granulation, the density of granules produced, and the quality attributes of the final tablets were also identified. Understanding the impact of the granulation and drying process parameters on granule and tablet properties provides a basis for process optimisation and scaling. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Antimicrobial-Coated Granules for Disinfecting Water

    Science.gov (United States)

    Akse, James R.; Holtsnider, John T.; Kliestik, Helen

    2011-01-01

    Methods of preparing antimicrobialcoated granules for disinfecting flowing potable water have been developed. Like the methods reported in the immediately preceding article, these methods involve chemical preparation of substrate surfaces (in this case, the surfaces of granules) to enable attachment of antimicrobial molecules to the surfaces via covalent bonds. A variety of granular materials have been coated with a variety of antimicrobial agents that include antibiotics, bacteriocins, enzymes, bactericides, and fungicides. When employed in packed beds in flowing water, these antimicrobial-coated granules have been proven effective against gram-positive bacteria, gram-negative bacteria, fungi, and viruses. Composite beds, consisting of multiple layers containing different granular antimicrobial media, have proven particularly effective against a broad spectrum of microorganisms. These media have also proven effective in enhancing or potentiating the biocidal effects of in-line iodinated resins and of very low levels of dissolved elemental iodine.

  9. Chromospheric impact of an exploding solar granule

    Science.gov (United States)

    Fischer, C. E.; Bello González, N.; Rezaei, R.

    2017-06-01

    Context. Observations of multi-wavelength and therefore height-dependent information following events throughout the solar atmosphere and unambiguously assigning a relation between these rapidly evolving layers are rare and difficult to obtain. Yet, they are crucial for our understanding of the physical processes that couple the different regimes in the solar atmosphere. Aims: We characterize the exploding granule event with simultaneous observations of Hinode spectroplarimetric data in the solar photosphere and Hinode broadband Ca II H images combined with Interface Region Imaging Spectrograph (IRIS) slit spectra. We follow the evolution of an exploding granule and its connectivity throughout the atmosphere and analyze the dynamics of a magnetic element that has been affected by the abnormal granule. Methods: In addition to magnetic flux maps we use a local correlation tracking method to infer the horizontal velocity flows in the photosphere and apply a wavelet analysis on several IRIS chromospheric emission features such as Mg II k2v and Mg II k3 to detect oscillatory phenomena indicating wave propagation. Results: During the vigorous expansion of the abnormal granule we detect radially outward horizontal flows, causing, together with the horizontal flows from the surrounding granules, the magnetic elements in the bordering intergranular lanes to be squeezed and elongated. In reaction to the squeezing, we detect a chromospheric intensity and velocity oscillation pulse which we identify as an upward traveling hot shock front propagating clearly through the IRIS spectral line diagnostics of Mg II h&k. Conclusions: Exploding granules can trigger upward-propagating shock fronts that dissipate in the chromosphere. Movies associated to Figs. A.1 and A.2 are available in electronic form at http://www.aanda.org

  10. Biosynthesis and characterization of polyhydroxyalkanoates copolymers produced by Pseudomonas putida Bet001 isolated from palm oil mill effluent.

    Directory of Open Access Journals (Sweden)

    Ahmad Mohammed Gumel

    Full Text Available The biosynthesis and characterization of medium chain length poly-3-hydroxyalkanoates (mcl-PHA produced by Pseudomonas putida Bet001 isolated from palm oil mill effluent was studied. The biosynthesis of mcl-PHA in this newly isolated microorganism follows a growth-associated trend. Mcl-PHA accumulation ranging from 49.7 to 68.9% on cell dry weight (CDW basis were observed when fatty acids ranging from octanoic acid (C(8:0 to oleic acid (C(18:1 were used as sole carbon and energy source. Molecular weight of the polymer was found to be ranging from 55.7 to 77.7 kDa. Depending on the type of fatty acid used, the (1H NMR and GCMSMS analyses of the chiral polymer showed a composition of even and odd carbon atom chain with monomer length of C4 to C14 with C8 and C10 as the principal monomers. No unsaturated monomer was detected. Thermo-chemical analyses showed the accumulated PHA to be semi-crystalline polymer with good thermal stability, having a thermal degradation temperature (T(d of 264.6 to 318.8 (± 0.2 (oC, melting temperature (T(m of 43. (± 0.2 (oC, glass transition temperature (T(g of -1.0 (± 0.2 (oC and apparent melting enthalpy of fusion (ΔH(f of 100.9 (± 0.1 J g(-1.

  11. Arachnoid granulation affected by subarachnoid hemorrhage

    Directory of Open Access Journals (Sweden)

    R.P. Chopard

    1993-11-01

    Full Text Available The purpose of this study was to investigate using light microscopy the fibro-cellular components of arachnoid granulations affected by mild and severe subarachnoid hemorrage. The erythrocytes were in the channels delimitated by collagenous and elastic bundles and arachnoid cells, showing their tortuous and intercommunicating row from the pedicle to the fibrous capsule. The core portion of the pedicle and the center represented a principal route to the bulk outflow of cerebrospinal fluid and erythrocytes. In the severe hemorrhage, the fibrocellular components are desorganized, increasing the extracellular channels. We could see arachnoid granulations without erythrocytes, which cells showed big round nucleous suggesting their transformation into phagocytic cells.

  12. Novel compaction techniques with pellet-containing granules.

    Science.gov (United States)

    Pan, Xin; Chen, Meiwan; Han, Ke; Peng, Xinsheng; Wen, Xinguo; Chen, Bao; Wang, Jin; Li, Ge; Wu, Chuanbin

    2010-08-01

    The purpose of this investigation was to introduce a new concept of admixing coated pellets with excipients to obtain a segregation-free combination of pellet-containing granules and cushioning granules during mixing and compression. Acrylic polymeric-coated pellets were granulated by centrifugal granulation method with excipients; then, the pellet-containing granules were compacted into tablets with the cushioning granules, which were prepared in mixer or fluidized bed-granulator. Tablets were also made in a traditional method by directly compressing the mixtures of coated pellets and cushioning granules for control. Drug-release profiles, weights and drug content of tables were tested to compare this new method with the traditional method. The granulation process changed the surface morphology of coated pellets from smooth to rough and increased the angle of repose of pellets to close to that of the cushioning granules. Weight and drug content RSD values of tablets prepared by pellet-containing granules were much lower than those of tablets prepared by coated pellets. The similarity factor f(2) values for drug-release profiles of tablets prepared from pellet-containing granules and the original coated pellets were above 50 when microcrystalline cellulose (MCC), Polyplasdone(R) XL (PVPP), and lactose were used as granulating excipients. The granulation process could roughen the surface of coated pellets and increase the angle of repose and uniformity of the mixture with cushioning granules. Compared with the tablets directly compressed from coated pellets, the tablets prepared by pellet-containing granules showed improved uniformity in both weight and drug content. The granulation and compression processes did not significantly influence the drug-release behavior of coated pellets, and the enteric dissolution was retained.

  13. Granule size distributions after twin-screw granulation - Do not forget the feeding systems.

    Science.gov (United States)

    Meier, R; Thommes, M; Rasenack, N; Moll, K-P; Krumme, M; Kleinebudde, P

    2016-09-01

    The aim of this study was to investigate the influence of qualitatively different powder feeder performances on resulting granule size distributions after twin-screw granulation of a highly drug loaded, hydrophobic mixture and a mannitol powder. It was shown that powder feeder related problems usually cannot be identified by trusting in the values given by the feeder. Therefore, a newly developed model for the evaluation of the performance of powder feeders was introduced and it was tried to connect this model to residence time distributions in twin-screw granulation processes. The influence of feeder performances on resulting granule size distributions varied, depending on the applied screw configuration and the used powder. Regarding the hydrophobic and highly drug loaded formulation, which was granulated at an L/S-ratio of 0.5, a pure conveying screw and a medium kneading configuration, consisting of 60° kneading blocks were negatively influenced by poor feeder settings. For optimal settings more narrow distributions could be obtained. For an extensive kneading configuration good and poor settings resulted in mono-modal granule size distributions but were differing in the overall size. Mannitol, a model substance for a liquid sensitive formulation was granulated at an L/S-ratio of 0.075. It was even more important to maintain optimal feeding as mannitol was highly affected by poor feeder performances. Even an extensive kneading configuration could not level the errors in powder feeder performance, resulting in qualitatively different granule size distributions. The results of this study demonstrate the importance of detailed knowledge about applied feeding systems to gain optimal performance in twin-screw granulation. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Application of fluidized hot-melt granulation (FHMG) for the preparation of granules for tableting; properties of granules and tablets prepared by FHMG.

    Science.gov (United States)

    Kidokoro, Motonori; Haramiishi, Yasuo; Sagasaki, Shinji; Shimizu, Tsutomu; Yamamoto, Yoji

    2002-01-01

    The objective of this study was to investigate the properties of granules and tablets prepared by a novel Fluidized Hot-Melt Granulation (FHMG) technique. Macrogol 6000 (polyethylene glycol 6000, PEG 6000), macrogol 20000 (polyethylene glycol 20000, PEG 20000), and glyceryl monostearate (GMS) were used as binders with different levels of viscosity and water solubility. The properties of both granules and tablets were compared with those obtained using the Standard Tablet Formulation (STF, lactose/corn starch/hydroxypropylcellulose/ magnesium stearate: 66/30/3.5/0.5) for fluidized-bed granulation, which is widely used for wet granulation. To obtain suitable flowability as granules for tabletting, the content of the melting material should be approximately 10 w/w%. The rate of increase in the mean diameter of the granules during FHMG was affected by both the melting temperature and the viscosity of the melting material used in the granules. The compression properties of granules prepared by FHMG were also investigated, demonstrating that these granules had a high pressure transmittance. The hardness and the disintegration time of tablets obtained from granules prepared by FHMG were influenced by the properties of the melting material, such as its compaction behavior, solubility, and wettability. No significant differences of hardness were observed when compared to STF tablets. Tablets prepared from FHMG granules disintegrated within 15 min, whereas the STF tablets showed faster disintegration. It was also demonstrated that the hardness and disintegration time of tablets prepared from FHMG granules were not affected by the tablet porosity. Therefore, tablets with a constant quality may be obtainable under a wide range of compression forces. The results of this study suggested that FHMG is a useful method of preparing granules for tableting without using any solvents or water.

  15. The evolution of granule fracture strength as a function of impeller tip speed and granule size for a novel reverse-phase wet granulation process.

    Science.gov (United States)

    Wade, J B; Martin, G P; Long, D F

    2015-07-05

    The feasibility of a novel reverse-phase wet granulation process has been established previously and several potential advantages over the conventional process have been highlighted (Wade et al., 2014a,b,b). Due to fundamental differences in the growth mechanism and granule consolidation behaviour between the two processes the reverse-phase approach generally formed granules with a greater mass mean diameter and a lower intragranular porosity than those formed by the conventional granulation process under the same liquid saturation and impeller tip speed conditions. The lower intragranular porosity was hypothesised to result in an increase in the granule strength and subsequent decrease in tablet tensile strength. Consequently, the aim of this study was to compare the effect of impeller tip speed and granule size on the strength and compaction properties of granules prepared using both the reverse-phase and conventional granulation processes. For the conventional granulation process an increase in the impeller tip speed from 1.57 to 4.71 ms(-1) (200-600 RPM) resulted in an increase in the mean granule strength (pgranule size fractions and as the granule size fraction increased from 425-600 to 2000-3350 μm the mean fracture strength decreased (p0.05) on mean granule strength whereas, like the conventional process, an increase in granule size fraction from 425-600 to 2000-3350 μm resulted in a decrease (pgranule fracture strength and the tablet tensile strength (p>0.05) for either granulation approach. These data support the rejection of the original hypothesis which stated that an increase in granule strength may result in a decrease in the tablet tensile strength. The similar tablet tensile strength observed between the conventional and reverse-phase granulation processes indicated that while mechanistic differences exist in the formation of the granules, which resulted in significant granule-scale fracture strength differences, the granule compaction properties

  16. EFFECT OF BINDER ON THE RELATIONSHIP BETWEEN BULK-DENSITY AND COMPACTIBILITY OF LACTOSE GRANULATIONS

    NARCIS (Netherlands)

    ZUURMAN, K; BOLHUIS, GK; VROMANS, H

    1995-01-01

    The effect of a binder on the relationship between the bulk density and compactibility of lactose granulations was studied by comparing binderless granules with granules containing hydroxypropylcellulose. Granulations were prepared from different grades of alpha-lactose monohydrate and anhydrous

  17. Detection and Analysis of the Quality of Ibuprofen Granules

    Science.gov (United States)

    Yu-bin, Ji; Xin, LI; Guo-song, Xin; Qin-bing, Xue

    2017-12-01

    The Ibuprofen Granules comprehensive quality testing to ensure that it is in accordance with the provisions of Chinese pharmacopoeia. With reference of Chinese pharmacopoeia, the Ibuprofen Granules is tested by UV, HPLC, in terms of grain size checking, volume deviation, weight loss on drying detection, dissolution rate detection, and quality evaluation. Results indicated that Ibuprofen Granules conform to the standards. The Ibuprofen Granules are qualified and should be permitted to be marketed.

  18. Tracheostomy Decannulation: Suprastomal Granulation Tissue in ...

    African Journals Online (AJOL)

    Background: Suprastomal granulation tissue is a complication of tracheostomy which may make decannulation difficult and presents a therapeutic challenge to the Otorhinolaryngologists. The aims of this study therefore were to evaluate tracheostomy in black African population, determine the prevalence of suprastomal ...

  19. Atrial natriuretic peptide (ANP)-granules: ultrastructure ...

    African Journals Online (AJOL)

    ANP) are present in the four regions of the atrial-auricular complex (two atria and two auricles). ANP-immunoreactivity was detected in all granules from the four regions. Ultrastructurally, atrial myocytes show the presence of very electron dense ...

  20. Next generation fluidized bed granulator automation.

    Science.gov (United States)

    Rantanen, J; Känsäkoski, M; Suhonen, J; Tenhunen, J; Lehtonen, S; Rajalahti, T; Mannermaa, J P; Yliruusi, J

    2000-05-06

    A system for fluidized bed granulator automation with in-line multichannel near infrared (NIR) moisture measurement and a unique air flow rate measurement design was assembled, and the information gained was investigated. The multivariate process data collected was analyzed using principal component analysis (PCA). The test materials (theophylline and microcrystalline cellulose) were granulated and the calibration behavior of the multichannel NIR set-up was evaluated against full Fourier Transform (FT) NIR spectra. Accurate and reliable process air flow rate measurement proved critical in controlling the granulation process. The process data describing the state of the process was projected in two dimensions, and the information from various trend charts was outlined simultaneously. The absorbence of test material at correction wavelengths (NIR region) and the nature of material-water interactions affected the detected in-line NIR water signal. This resulted in different calibration models for the test materials. Development of process analytical methods together with new data visualization algorithms creates new tools for in-process control of the fluidized bed granulation.

  1. Chinese herbal medicine shenqi detoxification granule ...

    African Journals Online (AJOL)

    Shenqi Detoxification Granule (SDG), a traditional Chinese herbal formula, has been used for treatment of chronic renal failure in clinic for many years. Materials and Methods: In order to evaluate the efficacy, and explore the mechanism of SDG to inhibit the progression of renal fibrosis, study was carried out using the ...

  2. Granulate of stainless steel as compensator material

    NARCIS (Netherlands)

    J.P.C. van Santvoort (J. P C)

    1995-01-01

    textabstractCompensators produced with computer controlled milling devices usually consist of a styrofoam mould, filled with an appropriate material. We investigated granulate of stainless steel as filling material. This cheap, easy to use, clean and re-usable material can be obtained with an

  3. Creep of granulated loose-fill insulation

    DEFF Research Database (Denmark)

    Rasmussen, Torben Valdbjørn

    with SP-Building Physics in Sweden and VTT Building Technology in Finland. For the round robin test a cellulosic fibre insulation material was used. The proposed standardised method for creep tests and theories are limited to cases when the granulated loose-fill material is exposed to a constant......, Organisation for Testing in Scandinavia funded the Nordtest....

  4. 21 CFR 520.1468 - Naproxen granules.

    Science.gov (United States)

    2010-04-01

    ... and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.1468 Naproxen granules. (a... musculoskeletal system of the horse. (2)(i) For oral maintenance therapy following initial intravenous dosage...

  5. The influence of granulating solvents on drug release from tablets ...

    African Journals Online (AJOL)

    ... significantly lower than the other wet granulated tablets, but higher than the matrix tablets. The granulating solvent influenced the release of drug which increased with increase in the water content. Key Words: Grewia gum: Granulating solvents; Release mechanisms. Journal of Pharmacy and Bioresources Vol.1(1) 2004: ...

  6. Which shape factor(s) best describe granules?

    NARCIS (Netherlands)

    Bouwman, Anneke M.; Bosma, Jaap C.; Vonk, Pieter; Wesselingh, J.A.; Frijlink, Henderik W.

    2004-01-01

    This study evaluates methods used for granule shape characterization. The aim is to identify an optimal combination of shape factors to measure granule shape and roughness. Granules were prepared from microcrystalline cellulose (MCC), alpha-lactose, microfine cellulose (MFC), and dextrin, using a

  7. Microbial synthesis of functional homo-, random, and block polyhydroxyalkanoates by β-oxidation deleted Pseudomonas entomophila

    DEFF Research Database (Denmark)

    Li, Shijun; Cai, Longwei; Wu, Linping

    2014-01-01

    -link with other PHA polymer chains. However, it has been very difficult to obtain structurally controllable functional homo-, random, or block PHA. For the first time, a β-oxidation deleted Pseudomonas entomophila was used to successfully synthesize random copolymers of 3-hydroxydodecanoate (3HDD) and 3-hydroxy-9......Functional polyhydroxyalkanoates (PHAs) allow chemical modifications to widen PHA diversity, promising to increase values of these biodegradable and biocompatible polyesters. Among functional PHAs, unsaturated PHA site chains can be easily grafted to add chemical groups, and to cross...... by feeding DDA as the first precursor to form a P3HDD block followed by adding 9DEO as the second precursor to form a second P3H9D block. It was demonstrated that random copolymers P(3HDD-co-3H9D) could be crossed-linked under UV-radiation due to the presence of the unsaturated bonds. Thermal and mechanical...

  8. Polyhydroxyalkanoate (PHA) synthesis by Spirulina subsalsa from Gujarat coast of India.

    Science.gov (United States)

    Shrivastav, Anupama; Mishra, Sanjiv K; Mishra, Sandhya

    2010-03-01

    Cyanobacteria have many unexploited potential for natural products with a huge variability in structure and biological activity. Their products are species specific and substrate+growth condition specific. Under stress conditions they are reported to produce biopolymers like EPS and PHA, which can be produced extracellularly and intracellularly, respectively. Polyhydroxyalkanoates are polymers of biological origin, they are also capable of being completely broken down to water and carbon dioxide by microorganisms found in a wide range of environments, such as soil, water, and sewage. We have studied marine cyanobacteria Spirulina subsalsa from Veraval coast, Gujarat, India, producing PHA under increased sodium chloride (NaCl) concentration (5% enhancement to the ASNIII medium), The biopolymer was chemically characterized through FTIR, NMR, TGA, and DSC. The present study shows increased PHA accumulation in S. subsalsa by twofold increased NaCl concentration in the growth media. 2010 Elsevier B.V. All rights reserved.

  9. Synthesis, production, and biotechnological applications of exopolysaccharides and polyhydroxyalkanoates by archaea.

    Science.gov (United States)

    Poli, Annarita; Di Donato, Paola; Abbamondi, Gennaro Roberto; Nicolaus, Barbara

    2011-01-01

    Extreme environments, generally characterized by atypical temperatures, pH, pressure, salinity, toxicity, and radiation levels, are inhabited by various microorganisms specifically adapted to these particular conditions, called extremophiles. Among these, the microorganisms belonging to the Archaea domain are of significant biotechnological importance as their biopolymers possess unique properties that offer insights into their biology and evolution. Particular attention has been devoted to two main types of biopolymers produced by such peculiar microorganisms, that is, the extracellular polysaccharides (EPSs), considered as a protection against desiccation and predation, and the endocellular polyhydroxyalkanoates (PHAs) that provide an internal reserve of carbon and energy. Here, we report the composition, biosynthesis, and production of EPSs and PHAs by different archaeal species.

  10. Synthesis, Production, and Biotechnological Applications of Exopolysaccharides and Polyhydroxyalkanoates by Archaea

    Directory of Open Access Journals (Sweden)

    Annarita Poli

    2011-01-01

    Full Text Available Extreme environments, generally characterized by atypical temperatures, pH, pressure, salinity, toxicity, and radiation levels, are inhabited by various microorganisms specifically adapted to these particular conditions, called extremophiles. Among these, the microorganisms belonging to the Archaea domain are of significant biotechnological importance as their biopolymers possess unique properties that offer insights into their biology and evolution. Particular attention has been devoted to two main types of biopolymers produced by such peculiar microorganisms, that is, the extracellular polysaccharides (EPSs, considered as a protection against desiccation and predation, and the endocellular polyhydroxyalkanoates (PHAs that provide an internal reserve of carbon and energy. Here, we report the composition, biosynthesis, and production of EPSs and PHAs by different archaeal species.

  11. Polyamines are present in mast cell secretory granules and are important for granule homeostasis.

    Science.gov (United States)

    García-Faroldi, Gianni; Rodríguez, Carlos E; Urdiales, José L; Pérez-Pomares, José M; Dávila, José C; Pejler, Gunnar; Sánchez-Jiménez, Francisca; Fajardo, Ignacio

    2010-11-30

    Mast cell secretory granules accommodate a large number of components, many of which interact with highly sulfated serglycin proteoglycan (PG) present within the granules. Polyamines (putrescine, spermidine and spermine) are absolutely required for the survival of the vast majority of living cells. Given the reported ability of polyamines to interact with PGs, we investigated the possibility that polyamines may be components of mast cell secretory granules. Spermidine was released by mouse bone marrow derived mast cells (BMMCs) after degranulation induced by IgE/anti-IgE or calcium ionophore A23187. Additionally, both spermidine and spermine were detected in isolated mouse mast cell granules. Further, depletion of polyamines by culturing BMMCs with α-difluoromethylornithine (DFMO) caused aberrant secretory granule ultrastructure, impaired histamine storage, reduced serotonin levels and increased β-hexosaminidase content. A proteomic approach revealed that DFMO-induced polyamine depletion caused an alteration in the levels of a number of proteins, many of which are connected either with the regulated exocytosis or with the endocytic system. Taken together, our results show evidence that polyamines are present in mast cell secretory granules and, furthermore, indicate an essential role of these polycations during the biogenesis and homeostasis of these organelles.

  12. Polyamines are present in mast cell secretory granules and are important for granule homeostasis.

    Directory of Open Access Journals (Sweden)

    Gianni García-Faroldi

    2010-11-01

    Full Text Available Mast cell secretory granules accommodate a large number of components, many of which interact with highly sulfated serglycin proteoglycan (PG present within the granules. Polyamines (putrescine, spermidine and spermine are absolutely required for the survival of the vast majority of living cells. Given the reported ability of polyamines to interact with PGs, we investigated the possibility that polyamines may be components of mast cell secretory granules.Spermidine was released by mouse bone marrow derived mast cells (BMMCs after degranulation induced by IgE/anti-IgE or calcium ionophore A23187. Additionally, both spermidine and spermine were detected in isolated mouse mast cell granules. Further, depletion of polyamines by culturing BMMCs with α-difluoromethylornithine (DFMO caused aberrant secretory granule ultrastructure, impaired histamine storage, reduced serotonin levels and increased β-hexosaminidase content. A proteomic approach revealed that DFMO-induced polyamine depletion caused an alteration in the levels of a number of proteins, many of which are connected either with the regulated exocytosis or with the endocytic system.Taken together, our results show evidence that polyamines are present in mast cell secretory granules and, furthermore, indicate an essential role of these polycations during the biogenesis and homeostasis of these organelles.

  13. Amylolytic hydrolysis of native starch granules affected by granule surface area.

    Science.gov (United States)

    Kim, J C; Kong, B W; Kim, M J; Lee, S H

    2008-11-01

    Initial stage of hydrolysis of native starch granules with various amylolytic enzymes, alpha-amylase from Bacillus subtilis, glucoamylase I (GA-I) and II (GA-II) from Aspergillus niger, and beta-amylase from sweet potato showed that the reaction was apparently affected by a specific surface area of the starch granules. The ratios of the reciprocal of initial velocity of each amylolytic hydrolysis for native potato and maize starch to that for rice with the amylolytic enzymes were nearly equivalent to the ratio of surface area per mass of the 2 starch granules to that of rice, that is, 6.94 and 2.25, respectively. Thus, the reciprocal of initial velocity of each enzymatic hydrolysis as expressed in a Lineweaver-Burk plot was a linear function of the reciprocal of surface area for each starch granule. As a result, it is concluded that amylolytic hydrolysis of native starch granules is governed by the specific surface area, not by the mass concentration, of each granule.

  14. Transformation of anaerobic granules into aerobic granules and the succession of bacterial community.

    Science.gov (United States)

    Sun, Haohao; Yu, Ping; Li, Qiaoling; Ren, Hongqiang; Liu, Bo; Ye, Lin; Zhang, Xu-Xiang

    2017-10-01

    In this study, we demonstrated that anaerobic granular sludge could be successfully transformed into aerobic granular sludge in a continuous up-flow reactor in 45 days. An aerobic microbial community successfully developed in the granules and high organic matter and nitrogen removal performance was achieved. Under an ammonia nitrogen loading rate of 0.8 kg N/(m 3 day), ammonia nitrogen and the total nitrogen removal efficiency of the reactor reached up to 100 and 93%, respectively. An obvious bacterial community shift in granular sludge was observed during the transformation process. By comparing with the bacterial community in aerobic granules cultivated from floccular activated sludge, some bacteria (affiliated with Comamonadaceae, Xanthomonadaceae, Rhodocyclaceae, Moraxellaceae, and Nitrosomonadaceae) playing significant roles in maintaining the structures and functions of aerobic granules were identified. After the transformation, the granules could be clearly separated into the inner core and outer shell. 16S rRNA gene sequencing results indicated many bacterial species present in both the inner core and outer shell; however, their abundance differed significantly. Overall, this study confirms the feasibility of transforming anaerobic granules into aerobic granules and provides novel approaches and insights to understand the microbial ecology in granular sludge.

  15. Cryo-SEM and Raman Spectroscopy Study of the Involvement of Polyhydroxyalkanoates in Stress Response of Bacteria

    Czech Academy of Sciences Publication Activity Database

    Krzyžánek, Vladislav; Hrubanová, Kamila; Samek, Ota; Obruča, S.; Márová, I.; Bernatová, Silvie; Šiler, Martin; Zemánek, Pavel

    2015-01-01

    Roč. 21, S3 (2015), s. 183-184 ISSN 1431-9276 R&D Projects: GA MŠk(CZ) LO1212; GA MŠk ED0017/01/01; GA ČR(CZ) GA15-20645S; GA ČR(CZ) GA14-20012S Institutional support: RVO:68081731 Keywords : cryo-SEM * Raman spectroscopy * polyhydroxyalkanoates Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.730, year: 2015

  16. In silico modeling of in situ fluidized bed melt granulation.

    Science.gov (United States)

    Aleksić, Ivana; Duriš, Jelena; Ilić, Ilija; Ibrić, Svetlana; Parojčić, Jelena; Srčič, Stanko

    2014-05-15

    Fluidized bed melt granulation has recently been recognized as a promising technique with numerous advantages over conventional granulation techniques. The aim of this study was to evaluate the possibility of using response surface methodology and artificial neural networks for optimizing in situ fluidized bed melt granulation and to compare them with regard to modeling ability and predictability. The experiments were organized in line with the Box-Behnken design. The influence of binder content, binder particle size, and granulation time on granule properties was evaluated. In addition to the response surface analysis, a multilayer perceptron neural network was applied for data modeling. It was found that in situ fluidized bed melt granulation can be used for production of spherical granules with good flowability. Binder particle size had the most pronounced influence on granule size and shape, suggesting the importance of this parameter in achieving desired granule properties. It was found that binder content can be a critical factor for the width of granule size distribution and yield when immersion and layering is the dominant agglomeration mechanism. The results obtained indicate that both in silico techniques can be useful tools in defining the design space and optimization of in situ fluidized bed melt granulation. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Polymorphic changes of thiamine hydrochloride during granulation and tableting.

    Science.gov (United States)

    Wöstheinrich, K; Schmidt, P C

    2001-07-01

    Thiamine hydrochloride was granulated using an instrumented fluidized bed granulator (Hüttlin HKC 05-TJ). Granules consisting of pure thiamine hydrochloride were produced using an aqueous solution of thiamine hydrochloride as the granulating liquid. The effects of process variables such as inlet air temperature, spray rate, and amount of granulating liquid on granule properties are described. Particle size distributions of granules depended mainly on the amount of granulating liquid sprayed into the powder bed. Granules were tableted on a rotary tablet press at four different compression forces. Crushing strengths and disintegration times of all tablets were found to be very low after manufacture, but increased considerably after 4 months of storage at room temperature. Granular materials showed "caking" under the same storage conditions. These changes could be attributed to alterations of the polymorphic form of thiamine hydrochloride. The water-free form, being present directly after granulation, absorbs humidity very fast and is transformed into the monohydrate, which is stable at room temperature. Loss of water takes place during the drying phase of the granulation process and on storage of the substance at temperatures of 50 degrees C and 80 degrees C. During storage at room temperature while exposed to humidity, a transformation into the hemihydrate was observed. This polymorph is transformed during thermal analysis at about 190 degrees C to a water-free form that is stable at higher temperatures.

  18. Factors Involved in Sludge Granulation under Anaerobic Conditions

    Directory of Open Access Journals (Sweden)

    Jalal Shayegan

    2011-03-01

    Full Text Available This paper investigates the effects of factors involved in sludge anaerobic granulation. Granulated sludge formation is the main parameter contributing to the success of UASB reactors. Anaerobic granulation leads to reduced reactor size, space requirement, and investment costs. Operation costs are also greatly reduced due to lack of aeration. An important parameter affecting process performance is the size of sludge granules; the factors involved in granule size will be investigated. Some of the important parameters of anaerobic sludge granulation are: existence of growth cores as inert particles or granulated sludge, process operational conditions (Sludge Loading Rate and Organic Loading Rate, Loading rate increase and …, and environment conditions (nutrients, temperature, pH, combination and ….

  19. Giant renin secretory granules in beige mouse renal afferent arterioles

    DEFF Research Database (Denmark)

    Jensen, B L; Rasch, Ruth; Nyengaard, Jens Randel

    1997-01-01

    The mutant beige mouse (C57BL/6 bg) has a disease characterised by abnormally enlarged cytoplasmic granules in a variety of cells. With the purpose of establishing a suitable cellular model for studying renin secretion, the present study was undertaken to compare renin granule morphology in beige.......5+/-0.3 mGoldblatt units/ml). The total volume of renin granules per afferent arteriole was similar in the two mice strains (1114 microm3 in the controls and 1507 microm3 in the beige mice). The total number of renin granules per arteriole as assessed by stereological techniques was about 1900 in controls...... (average granular volume 0.681 microm3), whereas 1-2 large granules were present per cell in beige mice. The volume of afferent arteriole that contained secretory granules was lower in the beige mice. We conclude that the beige mouse synthesizes, stores and releases active renin. Renin secretory granules...

  20. Differential sensitivity of polyhydroxyalkanoate producing bacteria to fermentation inhibitors and comparison of polyhydroxybutyrate production from Burkholderia cepacia and Pseudomonas pseudoflava

    Science.gov (United States)

    2013-01-01

    Background The aim of this study is determine the relative sensitivity of a panel of seven polyhydroxyalkanoate producing bacteria to a panel of seven lignocellulosic-derived fermentation inhibitors representing aliphatic acids, furans and phenolics. A further aim was to measure the polyhydroxybutyrate production of select organisms on lignocellulosic-derived monosaccharides arabinose, xylose, glucose and mannose. Findings We examined the sensitivity of seven polyhydroxyalkanoate producing bacteria: Azohydromonas lata, Bacillus megaterium, Bacillus cereus, Burkholderia cepacia, Pseudomonas olevorans, Pseudomonas pseudoflava and Ralstonia eutropha, against seven fermentation inhibitors produced by the saccharification of lignocellulose: acetic acid, levulinic acid, coumaric acid, ferulic acid, syringaldehyde, furfural, and hyroxymethyfurfural. There was significant variation in the sensitivity of these microbes to representative phenolics ranging from 0.25-1.5 g/L coumaric and ferulic acid and between 0.5-6.0 g/L syringaldehyde. Inhibition ranged from 0.37-4 g/L and 0.75-6 g/L with acetic acid and levulinic acid, respectively. B. cepacia and P. pseudoflava were selected for further analysis of polyhydroxyalkanoate production. Conclusions We find significant differences in sensitivity to the fermentation inhibitors tested and find these variations to be over a relevant concentration range given the concentrations of inhibitors typically found in lignocellulosic hydrolysates. Of the seven bacteria tested, B. cepacia demonstrated the greatest inhibitor tolerance. Similarly, of two organisms examined for polyhydroxybutyrate production, B. cepacia was notably more efficient when fermenting pentose substrates. PMID:23734728

  1. Increased accuracy of starch granule type quantification using mixture distributions.

    Science.gov (United States)

    Tanaka, Emi; Ral, Jean-Phillippe F; Li, Sean; Gaire, Raj; Cavanagh, Colin R; Cullis, Brian R; Whan, Alex

    2017-01-01

    The proportion of granule types in wheat starch is an important characteristic that can affect its functionality. It is widely accepted that granule types are either large, disc-shaped A-type granules or small, spherical B-type granules. Additionally, there are some reports of the tiny C-type granules. The differences between these granule types are due to its carbohydrate composition and crystallinity which is highly, but not perfectly, correlated with the granule size. A majority of the studies that have considered granule types analyse them based on a size threshold rather than chemical composition. This is understandable due to the expense of separating starch into different types. While the use of a size threshold to classify granule type is a low-cost measure, this results in misclassification. We present an alternative, statistical method to quantify the proportion of granule types by a fit of the mixture distribution, along with an R package, a web based app and a video tutorial for how to use the web app to enable its straightforward application. Our results show that the reliability of the genotypic effects increase approximately 60% using the proportions of the A-type and B-type granule estimated by the mixture distribution over the standard size-threshold measure. Although there was a marginal drop in reliability for C-type granules. The latter is likely due to the low observed genetic variance for C-type granules. The determination of the proportion of granule types from size-distribution is better achieved by using the mixing probabilities from the fit of the mixture distribution rather than using a size-threshold.

  2. Study of standard tablet formulation based on fluidized-bed granulation.

    Science.gov (United States)

    Sunada, H; Hasegawa, M; Makino, T; Sakamoto, H; Fujita, K; Tanino, T; Kokubo, H; Kawaguchi, T

    1998-03-01

    In this study, acetaminophen, ascorbic acid, and ethenzamide were selected as model drugs for tableting granules. Agitation and fluidized-bed granulation were carried out at three drug contents of 30, 50, and 70%. Compared with agitation granulation, granules made by fluidized-bed granulation showed superior compressibility with wide formulation allowance for drug type and amount. Fluidized-bed granulation resulted in less granule hardness and greater plastic deformability. The granules had considerable compactness and for tablets containing 70% ethenzamide, prolonged disintegration and dissolution times were noted. These are typical features of granules produced by fluidized-bed granulation.

  3. Polyhydroxyalkanoate production by a novel bacterium Massilia sp. UMI-21 isolated from seaweed, and molecular cloning of its polyhydroxyalkanoate synthase gene.

    Science.gov (United States)

    Han, Xuerong; Satoh, Yasuharu; Kuriki, Yumi; Seino, Teruyuki; Fujita, Shinji; Suda, Takanori; Kobayashi, Takanori; Tajima, Kenji

    2014-11-01

    We successfully isolated one microorganism (UMI-21) from Ulva, a green algae that contains starch. The strain UMI-21 can produce polyhydroxyalkanoate (PHA) from starch, maltotriose, or maltose as a sole carbon source. Taxonomic studies and 16S rDNA sequence analysis revealed that strain UMI-21 was phylogenetically related to species of the genus Massilia. The PHA content under the cultivation condition using a 10-L jar fermentor was 45.5% (w/w). This value was higher than that obtained after cultivation in a flask, suggesting the possibility of large-scale PHA production by UMI-21 from starch. A major issue for the industrial production of microbial PHAs is the very high production cost. Starch is a relatively inexpensive substrate that is also found in abundant seaweeds such as Ulva. Therefore, the strain isolated in this study may be very useful for producing PHA from seaweeds containing polysaccharides such as starch. In addition, a 3.7-kbp DNA fragment containing the whole PHA synthase gene (phaC) was obtained from the strain UMI-21. The results of open reading frame (ORF) analysis suggested that the DNA fragment contained two ORFs, which were composed of 1740 (phaC) and 564 bp (phaR). The deduced amino acid sequence of PhaC from strain UMI-21 shared high similarity with PhaC from Ralstonia eutropha, which is a representative PHA-producing bacterium with a class I PHA synthase. This is the first report for the cloning of the PHA synthase gene from Massilia species. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  4. Zymophagy: Selective Autophagy of Secretory Granules

    Directory of Open Access Journals (Sweden)

    Maria I. Vaccaro

    2012-01-01

    Full Text Available Timing is everything. That's especially true when it comes to the activation of enzymes created by the pancreas to break down food. Pancreatic enzymes are packed in secretory granules as precursor molecules called zymogens. In physiological conditions, those zymogens are activated only when they reach the gut, where they get to work releasing and distributing nutrients that we need to survive. If this process fails and the enzymes are prematurely activated within the pancreatic cell, before they are released from the gland, they break down the pancreas itself causing acute pancreatitis. This is a painful disease that ranges from a mild and autolimited process to a severe and lethal condition. Recently, we demonstrated that the pancreatic acinar cell is able to switch on a refined mechanism that could explain the autolimited form of the disease. This is a novel selective form of autophagy named zymophagy, a cellular process to specifically detect and degrade secretory granules containing activated enzymes before they can digest the organ. In this work, we revise the molecules and mechanisms that mediate zymophagy, a selective autophagy of secretory granules.

  5. Influence of binder droplet dimension on granulation rate during fluidized bed granulation.

    Science.gov (United States)

    Fujiwara, Maya; Dohi, Masafumi; Otsuka, Tomoko; Yamashita, Kazunari; Sako, Kazuhiro

    2013-01-01

    Here, we statistically identified the critical factor of the granulation rate during the fluidized bed granulation process. Lactose was selected as the excipient and was granulated with several binders, including hydroxypropyl cellulose, hydroxypropyl methyl cellulose, and polyvinylpyrrolidone. The viscosity, density, and surface tension of the binder solution, contact angle, and the work done during adhesion and cohesion between the binder and lactose, mist diameter, Stokes number, and the dimension of the droplet were considered. The Stokes number was defined as the ratio of the inertial force to the viscous-damping force of a particle. We confirmed that droplet diameter after adhesion had the highest correlation coefficient with the granulation rate constant in our investigated parameters. Partial least squares regression revealed two critical principal components of the granulation rate: one relating to the droplet dimension, which is composed of mist diameter and diameter and thickness of the droplet after adhesion of the binder to the lactose surface; and the other relating to wettability, which involves the work done during adhesion and cohesion, surface tension, and the thickness of the droplet after adhesion of the binder to the lactose surface.

  6. PTEN deletion from adult-generated dentate granule cells disrupts granule cell mossy fiber axon structure.

    Science.gov (United States)

    LaSarge, Candi L; Santos, Victor R; Danzer, Steve C

    2015-03-01

    Dysregulation of the mTOR-signaling pathway is implicated in the development of temporal lobe epilepsy. In mice, deletion of PTEN from hippocampal dentate granule cells leads to mTOR hyperactivation and promotes the rapid onset of spontaneous seizures. The mechanism by which these abnormal cells initiate epileptogenesis, however, is unclear. PTEN-knockout granule cells develop abnormally, exhibiting morphological features indicative of increased excitatory input. If these cells are directly responsible for seizure genesis, it follows that they should also possess increased output. To test this prediction, dentate granule cell axon morphology was quantified in control and PTEN-knockout mice. Unexpectedly, PTEN deletion increased giant mossy fiber bouton spacing along the axon length, suggesting reduced innervation of CA3. Increased width of the mossy fiber axon pathway in stratum lucidum, however, which likely reflects an unusual increase in mossy fiber axon collateralization in this region, offsets the reduction in boutons per axon length. These morphological changes predict a net increase in granule cell innervation of CA3. Increased diameter of axons from PTEN-knockout cells would further enhance granule cell communication with CA3. Altogether, these findings suggest that amplified information flow through the hippocampal circuit contributes to seizure occurrence in the PTEN-knockout mouse model of temporal lobe epilepsy. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Comparison of the granulation behavior of three different excipients in a laboratory fluidized bed granulator using statistical methods.

    Science.gov (United States)

    Schinzinger, Oliver; Schmidt, Peter C

    2005-01-01

    The granulation process and, subsequently, the tableting behavior of the resulting granules of alpha-lactose-monohydrate, dicalcium phosphate anhydrous, and potato starch were investigated using statistical designs. The three substances were chosen due to their differences in granulation and tableting behavior, such as water solubility, swelling, and compressional properties. Granulation process variables, namely the inlet air temperature, spray rate, binder concentration of granulating solution, and inlet air flow rate were investigated. A central composite design was applied to study the granulation of alpha-lactose-monohydrate. Granulations of dicalcium phosphate and potato starch were investigated using a 2(3) factorial design, in which the effects of the inlet air temperature, spray rate, and binder concentration were considered. To compare the granulation behavior of theses substances the particle size distribution, angle of repose, and yield of the granules were used as responses for the statistical designs. The granules were compressed into tablets and the tensile strength was used as an additional statistical response. Based on the process parameters, models were developed using multiple regression modeling for each examined response. These models were then used to optimize the granulation process that provides granules with a Sauter mean diameter of D32 between 300 and 500 microm, an angle of repose smaller than 36 degrees and a granule yield above 90%. Moreover, the values of the tensile strength of the tablets should be between 1.6 and 2.5 N/mm2. The intersections of the response surfaces of each examined substance were compared using contour plots. To achieve the largest "satisfactory zone," the granulations of milled alpha-lactose-monohydrate, dicalcium phosphate, or potato starch should be performed at low inlet air temperatures.

  8. Scaling up of the fluidized bed granulation process.

    Science.gov (United States)

    Rambali, B; Baert, L; Massart, D L

    2003-02-18

    The scaling up of a fluidized bed granulation process from small scale to production scale is often done empirically in the pharmaceutical industry. In this study, a more practical and systematic method was developed in order to achieve a similar granule size in the scaled up fluid bed. The scaling up is based on the relative droplet size, and the powder bed moisture content at the end of the spraying cycle. The present study describes the scaling up of the fluidized granulation process from small (5 kg scale) to medium (30 kg scale) and to production fluid bed scale (120 kg scale). The granulation process is scaled up with as target a geometric mean granule size of 400 microm. First, the effect of the relative droplet size on the granule size was investigated in the different fluid beds. The effect of the change in relative droplet size on the granule size was different for each fluid bed. Second, experimental design is applied on the small and the medium fluid scale, and regression models for the granule size are proposed in order to scale up the granulation process on the small to medium scale. The granulation process was also successful by scaling-up to the large fluid bed, considering only the relative droplet size.

  9. Effect of vortex orifice air distributor on granule growth in conical fluidized bed granulation with bottom entry spray

    Energy Technology Data Exchange (ETDEWEB)

    Kurita, Y.; Sekiguchi, I. [Chuo Univ., Tokyo (Japan). Faculty of Science and Engineering

    2000-02-01

    This investigation is undertaken to obtain information on the effect of vortex orifice air distributors on the granule growth in conical fluidized bed granulation with a bottom entry spray. The five types of vortex orifice distributors suitable for a strong swirling air supply at the base of the conical bed were prepared. Although all these orifices consisted of four tangential injection nozzles with the same opening, the opening size of the air injection nozzle in each of the orifices was different. Intensity of the air injection nozzle torque within the vortex orifice was measured by a torque balance method. The granule formation of fluidising lactose particles in the process of size-enlargement was carried out by spraying an aqueous HPC solution into the bed where the moisture content of granules was maintained at or below 0.30 wt %. As a result, granule growth in the bed could be precisely controlled by changes in the air injection nozzle torques arising from the vortex orifice distributor. The extent of granule growth, namely the granule growth conversion increasing with accumulated content of HPC in the bed particles during the operating time decreased according to the air injection nozzle torque within the vortex orifice. Using these process variables, granule growth conversion could be arranged experimentally. It is finally found that one of the features of the proposed air distributor is useful for size-control of granule products in the conical fluidized bed granulation with a bottom entry spray. (author)

  10. Visualization and understanding of the granulation liquid mixing and distribution during continuous twin screw granulation using NIR chemical imaging.

    Science.gov (United States)

    Vercruysse, Jurgen; Toiviainen, Maunu; Fonteyne, Margot; Helkimo, Niko; Ketolainen, Jarkko; Juuti, Mikko; Delaet, Urbain; Van Assche, Ivo; Remon, Jean Paul; Vervaet, Chris; De Beer, Thomas

    2014-04-01

    Over the last decade, there has been increased interest in the application of twin screw granulation as a continuous wet granulation technique for pharmaceutical drug formulations. However, the mixing of granulation liquid and powder material during the short residence time inside the screw chamber and the atypical particle size distribution (PSD) of granules produced by twin screw granulation is not yet fully understood. Therefore, this study aims at visualizing the granulation liquid mixing and distribution during continuous twin screw granulation using NIR chemical imaging. In first instance, the residence time of material inside the barrel was investigated as function of screw speed and moisture content followed by the visualization of the granulation liquid distribution as function of different formulation and process parameters (liquid feed rate, liquid addition method, screw configuration, moisture content and barrel filling degree). The link between moisture uniformity and granule size distributions was also studied. For residence time analysis, increased screw speed and lower moisture content resulted to a shorter mean residence time and narrower residence time distribution. Besides, the distribution of granulation liquid was more homogenous at higher moisture content and with more kneading zones on the granulator screws. After optimization of the screw configuration, a two-level full factorial experimental design was performed to evaluate the influence of moisture content, screw speed and powder feed rate on the mixing efficiency of the powder and liquid phase. From these results, it was concluded that only increasing the moisture content significantly improved the granulation liquid distribution. This study demonstrates that NIR chemical imaging is a fast and adequate measurement tool for allowing process visualization and hence for providing better process understanding of a continuous twin screw granulation system. Copyright © 2013 Elsevier B.V. All

  11. Comparison of Different Granulation Techniques for Lactose Monohydrate

    OpenAIRE

    Pankaj Patel; Darshan Telange; Nitesh Sharma

    2011-01-01

    The objective of this study was directed to improve the physical and technical properties of poorly flowing and highly cohesive Lactose monohydrate to solve the most important problem that affects tablet manufacture. To overcome all the problems related to lactose granulation is required. Granulation is one of the most important unit operations in the production of pharmaceutical oral dosage forms. Granulation process will improve flow and compression characteristics, reduce segregation, impr...

  12. Giant arachnoid granulation in a patient with benign intracranial hypertension

    Energy Technology Data Exchange (ETDEWEB)

    Kiroglu, Yilmaz; Yaqci, Baki; Cirak, Bayram; Karabulut, Nevzat [Pamukkale University, Department of Radiology, School of Medicine, Denizli (Turkey)

    2008-10-15

    We report magnetic resonance (MR), computed tomography (CT) and angiographic imaging of an unusual giant arachnoid granulation in the superior sagittal sinus in a man with headache and vertigo. Intrasinus pressure measurements revealed a significant pressure gradient across the lesion. MR imaging is useful to identify giant arachnoid granulation and dural sinus thrombosis, whereas dural sinus pressure measurement in certain cases of giant arachnoid granulations can be used to evaluate the lesion as the cause of the patient's symptoms. (orig.)

  13. Giant arachnoid granulation in a patient with benign intracranial hypertension

    International Nuclear Information System (INIS)

    Kiroglu, Yilmaz; Yaqci, Baki; Cirak, Bayram; Karabulut, Nevzat

    2008-01-01

    We report magnetic resonance (MR), computed tomography (CT) and angiographic imaging of an unusual giant arachnoid granulation in the superior sagittal sinus in a man with headache and vertigo. Intrasinus pressure measurements revealed a significant pressure gradient across the lesion. MR imaging is useful to identify giant arachnoid granulation and dural sinus thrombosis, whereas dural sinus pressure measurement in certain cases of giant arachnoid granulations can be used to evaluate the lesion as the cause of the patient's symptoms. (orig.)

  14. Aerobic granules: microbial landscape and architecture, stages, and practical implications.

    Science.gov (United States)

    Gonzalez-Gil, Graciela; Holliger, Christof

    2014-06-01

    For the successful application of aerobic granules in wastewater treatment, granules containing an appropriate microbial assembly able to remove contaminants should be retained and propagated within the reactor. To manipulate and/or optimize this process, a good understanding of the formation and dynamic architecture of the granules is desirable. Models of granules often assume a spherical shape with an outer layer and an inner core, but limited information is available regarding the extent of deviations from such assumptions. We report on new imaging approaches to gain detailed insights into the structural characteristics of aerobic granules. Our approach stained all components of the granule to obtain a high quality contrast in the images; hence limitations due to thresholding in the image analysis were overcome. A three-dimensional reconstruction of the granular structure was obtained that revealed the mesoscopic impression of the cavernlike interior of the structure, showing channels and dead-end paths in detail. In "old" granules, large cavities allowed for the irrigation and growth of dense microbial colonies along the path of the channels. Hence, in some areas, paradoxically higher biomass content was observed in the inner part of the granule compared to the outer part. Microbial clusters "rooting" from the interior of the mature granule structure indicate that granules mainly grow via biomass outgrowth and not by aggregation of small particles. We identify and discuss phenomena contributing to the life cycle of aerobic granules. With our approach, volumetric tetrahedral grids are generated that may be used to validate complex models of granule formation.

  15. Aerobic Granules: Microbial Landscape and Architecture, Stages, and Practical Implications

    Science.gov (United States)

    Holliger, Christof

    2014-01-01

    For the successful application of aerobic granules in wastewater treatment, granules containing an appropriate microbial assembly able to remove contaminants should be retained and propagated within the reactor. To manipulate and/or optimize this process, a good understanding of the formation and dynamic architecture of the granules is desirable. Models of granules often assume a spherical shape with an outer layer and an inner core, but limited information is available regarding the extent of deviations from such assumptions. We report on new imaging approaches to gain detailed insights into the structural characteristics of aerobic granules. Our approach stained all components of the granule to obtain a high quality contrast in the images; hence limitations due to thresholding in the image analysis were overcome. A three-dimensional reconstruction of the granular structure was obtained that revealed the mesoscopic impression of the cavernlike interior of the structure, showing channels and dead-end paths in detail. In “old” granules, large cavities allowed for the irrigation and growth of dense microbial colonies along the path of the channels. Hence, in some areas, paradoxically higher biomass content was observed in the inner part of the granule compared to the outer part. Microbial clusters “rooting” from the interior of the mature granule structure indicate that granules mainly grow via biomass outgrowth and not by aggregation of small particles. We identify and discuss phenomena contributing to the life cycle of aerobic granules. With our approach, volumetric tetrahedral grids are generated that may be used to validate complex models of granule formation. PMID:24657859

  16. Rab3A, a possible marker of cortical granules, participates in cortical granule exocytosis in mouse eggs

    Energy Technology Data Exchange (ETDEWEB)

    Bello, Oscar Daniel; Cappa, Andrea Isabel; Paola, Matilde de; Zanetti, María Natalia [Instituto de Histología y Embriología, CONICET – Universidad Nacional de Cuyo, Av. Libertador 80, 5500 Mendoza (Argentina); Fukuda, Mitsunori [Department of Developmental Biology and Neurosciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8578 (Japan); Fissore, Rafael A. [Department of Veterinary and Animal Sciences, University of Massachusetts Amherst, 661 North Pleasant Street, Amherst, MA 01003 (United States); Mayorga, Luis S. [Instituto de Histología y Embriología, CONICET – Universidad Nacional de Cuyo, Av. Libertador 80, 5500 Mendoza (Argentina); Michaut, Marcela A., E-mail: mmichaut@gmail.com [Instituto de Histología y Embriología, CONICET – Universidad Nacional de Cuyo, Av. Libertador 80, 5500 Mendoza (Argentina); Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo (Argentina)

    2016-09-10

    Fusion of cortical granules with the oocyte plasma membrane is the most significant event to prevent polyspermy. This particular exocytosis, also known as cortical reaction, is regulated by calcium and its molecular mechanism is still not known. Rab3A, a member of the small GTP-binding protein superfamily, has been implicated in calcium-dependent exocytosis and is not yet clear whether Rab3A participates in cortical granules exocytosis. Here, we examine the involvement of Rab3A in the physiology of cortical granules, particularly, in their distribution during oocyte maturation and activation, and their participation in membrane fusion during cortical granule exocytosis. Immunofluorescence and Western blot analysis showed that Rab3A and cortical granules have a similar migration pattern during oocyte maturation, and that Rab3A is no longer detected after cortical granule exocytosis. These results suggested that Rab3A might be a marker of cortical granules. Overexpression of EGFP-Rab3A colocalized with cortical granules with a Pearson correlation coefficient of +0.967, indicating that Rab3A and cortical granules have almost a perfect colocalization in the egg cortical region. Using a functional assay, we demonstrated that microinjection of recombinant, prenylated and active GST-Rab3A triggered cortical granule exocytosis, indicating that Rab3A has an active role in this secretory pathway. To confirm this active role, we inhibited the function of endogenous Rab3A by microinjecting a polyclonal antibody raised against Rab3A prior to parthenogenetic activation. Our results showed that Rab3A antibody microinjection abolished cortical granule exocytosis in parthenogenetically activated oocytes. Altogether, our findings confirm that Rab3A might function as a marker of cortical granules and participates in cortical granule exocytosis in mouse eggs. - Highlights: • Rab3A has a similar migration pattern to cortical granules in mouse oocytes. • Rab3A can be a marker of

  17. Multimodal sensory integration in single cerebellar granule cells in vivo.

    Science.gov (United States)

    Ishikawa, Taro; Shimuta, Misa; Häusser, Michael

    2015-12-29

    The mammalian cerebellum is a highly multimodal structure, receiving inputs from multiple sensory modalities and integrating them during complex sensorimotor coordination tasks. Previously, using cell-type-specific anatomical projection mapping, it was shown that multimodal pathways converge onto individual cerebellar granule cells (Huang et al., 2013). Here we directly measure synaptic currents using in vivo patch-clamp recordings and confirm that a subset of single granule cells receive convergent functional multimodal (somatosensory, auditory, and visual) inputs via separate mossy fibers. Furthermore, we show that the integration of multimodal signals by granule cells can enhance action potential output. These recordings directly demonstrate functional convergence of multimodal signals onto single granule cells.

  18. Growth and Localization of Polyhydroxybutyrate Granules in Ralstonia eutropha

    Science.gov (United States)

    Beeby, Morgan; Cho, Mimi

    2012-01-01

    The bacterium Ralstonia eutropha forms cytoplasmic granules of polyhydroxybutyrate that are a source of biodegradable thermoplastic. While much is known about the biochemistry of polyhydroxybutyrate production, the cell biology of granule formation and growth remains unclear. Previous studies have suggested that granules form either in the inner membrane, on a central scaffold, or in the cytoplasm. Here we used electron cryotomography to monitor granule genesis and development in 3 dimensions (3-D) in a near-native, “frozen-hydrated” state in intact Ralstonia eutropha cells. Neither nascent granules within the cell membrane nor scaffolds were seen. Instead, granules of all sizes resided toward the center of the cytoplasm along the length of the cell and exhibited a discontinuous surface layer more consistent with a partial protein coating than either a lipid mono- or bilayer. Putatively fusing granules were also seen, suggesting that small granules are continually generated and then grow and merge. Together, these observations support a model of biogenesis wherein granules form in the cytoplasm coated not by phospholipid but by protein. Previous thin-section electron microscopy (EM), fluorescence microscopy, and atomic force microscopy (AFM) results to the contrary may reflect both differences in nucleoid condensation and specimen preparation-induced artifacts. PMID:22178974

  19. Lunar gravity pattern: two modes of granulation

    Science.gov (United States)

    Kochemasov, G.

    The Lunar Prospector's lunar gravity map [1] clearly shows two prevailing modes of granulation. Most abundant one evenly covering the whole surface is represented by even-sized shoulder-to-shoulder grains about 100 km in diameter (πR/60 -πR/48). This background is interrupted by a few much greater grains with a characteristic diameter about or less than πR/4 (hundreds to thousand km). Haw to explain this pattern? We now know that "orbits make structures"[2 & others]. This follows from the facts that all celestial bodies move in non-round (elliptical, parabolic) orbits and rotate. Cyclic movements in non-round orbits with periodically changing accelerations arouse inertia-gravity forces exiting warping waves of stationary character and 4 ortho- and diagonal directions. Interferences of these waves produce tectonic blocks of various sizes depending on wavelengths. Along with the fundamental wave1making ubiquitous dichotomy and its overtones (mainly the first one wave2) making tectonic sectors, every body is subjected to a warping action of waves whose lengths are strictly proportional to bodies orbital periods or inversely proportional to their orbital frequencies. These individual waves are responsible for ubiquitous tectonic granulation. Most known from the thirties of the 20th century is the solar supergranulation with the characteristic granule size about 30000 km (πR/60) corresponding to its orbital frequency around the center of the solar system about 1/1 month. But the same orbital frequency has the Moon around Earth. So, one might expect to find similar granulation in the lunar crust. This theoretical assumption was perfectly confirmed when a lunar gravity map was created [1]. Thus, the Sun's 30000 km supergranules are the same as the Moon's 100 km granules. Farther from Sun, the terrestrial planets orbital frequencies diminish and concordantly granule sizes increase: Mercury πR/16, Venus πR/6, Earth πR/4, Mars πR/2, asteroids πR/1. This sizes are

  20. Recycling of Waste Streams of the Biotechnological Poly(hydroxyalkanoate Production by Haloferax mediterranei on Whey

    Directory of Open Access Journals (Sweden)

    Martin Koller

    2015-01-01

    Full Text Available For manufacturing “bioplastics” such as poly(hydroxyalkanoates (PHA, the combination of utilization of inexpensive carbon sources with the application of robust microbial production strains is considered a decisive step to make this process more cost-efficient and sustainable. PHA production based on surplus whey from dairy industry was accomplished by the extremely halophile archaeon Haloferax mediterranei. After fermentative production of PHA-rich biomass and the subsequent cell harvest and downstream processing for PHA recovery, environmentally hazardous, highly saline residues, namely spent fermentation broth and cell debris, remain as residues. These waste streams were used for recycling experiments to assess their recyclability in subsequent production processes. It was demonstrated that spent fermentation broth can be used to replace a considerable part of fresh saline fermentation medium in subsequent production processes. In addition, 29% of the expensive yeast extract, needed as nitrogen and phosphate source for efficient cultivation of the microorganism, can be replaced by cell debris from prior cultivations. The presented study provides strategies to combine the reduction of costs for biomediated PHA production with minimizing ecological risks by recycling precarious waste streams. Overall, the presented work shall contribute to the quick economic success of these promising biomaterials.

  1. Acidogenic spent wash valorization through polyhydroxyalkanoate (PHA) synthesis coupled with fermentative biohydrogen production.

    Science.gov (United States)

    Amulya, K; Reddy, M Venkateswar; Mohan, S Venkata

    2014-04-01

    The production of polyhydroxyalkanoates (PHAs) by Bacillus tequilensis biocatalyst using spent wash effluents as substrate was evaluated to increase the versatility of the existing PHA production process and reduce production cost. In this study, spent wash was used as a substrate for biohydrogen (H2) production and the resulting acidogenic effluents were subsequently employed as substrate for PHA production. Maximum H2 production of 39.8L and maximum PHA accumulation of 40% dry cell weight was attained. Good substrate removal associated with decrement in acidification (53% to 15%) indicates that the VFA generated were effectively utilized for PHA production. The PHA composition showed presence of copolymer [P (3HB-co-3HV)] with varying contents of hydroxybutyrate and hydroxyvalerate. The results obtained suggest that the use of spent wash effluents as substrate can considerably reduce the production cost of PHA with simultaneous waste valorization. PHA synthesis with B. tequilensis and spent wash effluents is reported for the first time. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Renewable Alkenes from the Hydrothermal Treatment of Polyhydroxyalkanoates-Containing Sludge.

    Science.gov (United States)

    Torri, Cristian; Weme, Tom Detert Oude; Samorì, Chiara; Kiwan, Alisar; Brilman, Derk W F

    2017-11-07

    Polyhydroxyalkanoates (PHA) are a key constituent of excess sludge produced by Aerobic Sewage Sludge Treatment plants. The accumulation of significant amount of PHA inside aerobic microbial cells occurs when a surplus of an easily degradable carbon source (e.g., volatile fatty acids, VFA) is found in combination with other nutrients limitation. Herein, hydrothermal treatment (HT) of PHA-containing sludge at 300 and 375 °C was demonstrated to be effective in converting most (>70% w/w) of the bacterial PHA stored inside microbial cells into alkene/CO 2 gas mixtures. Simultaneously, most of non-PHA biomass was converted into water-soluble compounds (50% carbon yield) that were acidogenic fermented to produce volatile fatty acids, ideal substrate to feed aerobic bacteria and produce more PHA. According to results here presented, HT of excess sludge with moderate (13%) PHA content can produce about 50 kg of alkenes per tonne of suspended solids treated, with a significant reduction of sludge mass (80% reduction of wet sludge volume) and consequent disposal cost.

  3. Polyhydroxyalkanoates production with Ralstonia eutropha from low quality waste animal fats.

    Science.gov (United States)

    Riedel, Sebastian L; Jahns, Stefan; Koenig, Steven; Bock, Martina C E; Brigham, Christopher J; Bader, Johannes; Stahl, Ulf

    2015-11-20

    Polyhydroxyalkanoates (PHAs) are biodegradable and biocompatible polyesters considered as alternatives to petroleum-based plastics. Ralstonia eutropha is a model organism for PHA production. Utilizing industrially rendered waste animal fats as inexpensive carbon feedstocks for PHA production is demonstrated here. An emulsification strategy, without any mechanical or chemical pre-treatment, was developed to increase the bioavailability of solid, poorly-consumable fats. Wild type R. eutropha strain H16 produced 79-82% (w/w) polyhydroxybutyrate (PHB) per cell dry weight (CDW) when cultivated on various fats. A productivity of 0.3g PHB/(L × h) with a total PHB production of 24 g/L was achieved using tallow as carbon source. Using a recombinant strain of R. eutropha that produces poly(hydroxybutyrate-co-hydroxyhexanoate) [P(HB-co-HHx)], 49-72% (w/w) of PHA per CDW with a HHx content of 16-27 mol% were produced in shaking flask experiments. The recombinant strain was grown on waste animal fat of the lowest quality available at lab fermenter scale, resulting in 45 g/L CDW with 60% (w/w) PHA per CDW and a productivity of 0.4 g PHA/(L × h). The final HHx content of the polymer was 19 mol%. The use of low quality waste animal fats as an inexpensive carbon feedstock exhibits a high potential to accelerate the commercialization of PHAs. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Perspectives on the production of polyhydroxyalkanoates in biorefineries associated with the production of sugar and ethanol.

    Science.gov (United States)

    Silva, Luiziana Ferreira; Taciro, Marilda Keico; Raicher, Gil; Piccoli, Rosane Aparecida Moniz; Mendonça, Thatiane Teixeira; Lopes, Mateus Schreiner Garcez; Gomez, José Gregório Cabrera

    2014-11-01

    Polyhydroxyalkanoates (PHA) are biodegradable and biocompatible bacterial thermoplastic polymers that can be obtained from renewable resources. The high impact of the carbon source in the final cost of this polymer has been one of the major limiting factors for PHA production and agricultural residues, mainly lignocellulosic materials, have gained attention to overcome this problem. In Brazil, production of 2nd generation ethanol from the glucose fraction, derived from sugarcane bagasse hydrolysate has been studied. The huge amounts of remaining xylose will create an opportunity for the development of other bioprocesses, generating new products to be introduced into a biorefinery model. Although PHA production from sucrose integrated to a 1G ethanol and sugar mill has been proposed in the past, the integration of the process of 2G ethanol in the context of a biorefinery will provide enormous amounts of xylose, which could be applied to produce PHA, establishing a second-generation of PHA production process. Those aspects and perspectives are presented in this article. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. UTILIZATION OF MUSTARD OIL FOR THE PRODUCTION OF POLYHYDROXYALKANOATES BY Pseudomonas aeruginosa

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    Hasnain Javed

    2015-04-01

    Full Text Available With the unnecessary use of plastics and cumulative pressure being placed on capacities available for plastic waste disposal, the need for biodegradable plastics and biodegradation of plastic wastes has assumed increasing importance in the last few years. Bioplastic production from mustard oil was considered relatively cheap, easily available, included in vegetable oil and don’t having much volatile characteristics. Total of 67 bacterial strains were isolated and purified from different regions of the Pakistan, and were checked for Polyhydroxyalkanoates (PHA production by Sudan black and Nile blue staining. Quantitative analysis for biodegradable plastic produced by different bacterial species was performed by Modified surfactant hypochlorite method. High PHA production was detected in 35 strains belonging to different genera including Pseudomonas, Staphylococcus, Escherichia and Enterobacter. Fermentation and PHA production was done in batch culture. The PHA production of P. aeruginosa by mustered oil cultivation was studied under six experimental conditions, such as air flow rates, pH, Temperature, optical density, substrates concentration and cell dry weight. PHA production of Pseudomonas species were subsequently authenticated at molecular level by PCR amplifications and sequence analysis. PHA polymerase 1 (PhaC1 and PHA polymerase 2 (PhaC2 from Pseudomonas aeruginosa were amplified, sequenced and submitted to gene bank.

  6. Peroxisomal polyhydroxyalkanoate biosynthesis is a promising strategy for bioplastic production in high biomass crops.

    Science.gov (United States)

    Tilbrook, Kimberley; Gebbie, Leigh; Schenk, Peer M; Poirier, Yves; Brumbley, Stevens M

    2011-12-01

    Polyhydroxyalkanoates (PHAs) are bacterial carbon storage polymers with diverse plastic-like properties. PHA biosynthesis in transgenic plants is being developed as a way to reduce the cost and increase the sustainability of industrial PHA production. The homopolymer polyhydroxybutyrate (PHB) is the simplest form of these biodegradable polyesters. Plant peroxisomes contain the substrate molecules and necessary reducing power for PHB biosynthesis, but peroxisomal PHB production has not been explored in whole soil-grown transgenic plants to date. We generated transgenic sugarcane (Saccharum sp.) with the three-enzyme Ralstonia eutropha PHA biosynthetic pathway targeted to peroxisomes. We also introduced the pathway into Arabidopsis thaliana, as a model system for studying and manipulating peroxisomal PHB production. PHB, at levels up to 1.6%-1.8% dry weight, accumulated in sugarcane leaves and A. thaliana seedlings, respectively. In sugarcane, PHB accumulated throughout most leaf cell types in both peroxisomes and vacuoles. A small percentage of total polymer was also identified as the copolymer poly (3-hydroxybutyrate-co-3-hydroxyvalerate) in both plant species. No obvious deleterious effect was observed on plant growth because of peroxisomal PHA biosynthesis at these levels. This study highlights how using peroxisomal metabolism for PHA biosynthesis could significantly contribute to reaching commercial production levels of PHAs in crop plants. © 2011 The Authors. Plant Biotechnology Journal © 2011 Society for Experimental Biology, Association of Applied Biologists and Blackwell Publishing Ltd.

  7. Development and Characterization of a Metal Injection Molding Bio Sourced Inconel 718 Feedstock Based on Polyhydroxyalkanoates

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    Alexandre Royer

    2016-04-01

    Full Text Available The binder plays the most important role in the metal injection molding (MIM process. It provides fluidity of the feedstock mixture and adhesion of the powder to keep the molded shape during injection molding. The binder must provide strength and cohesion for the molded part and must be easy to remove from the molded part. Moreover, it must be recyclable, environmentally friendly and economical. Also, the miscibility between polymers affects the homogeneity of the injected parts. The goal of this study is to develop a feedstock of superalloy Inconel 718 that is environmentally friendly. For these different binders, formulations based on polyethylene glycol (PEG, because of his water solubility property, and bio sourced polymers were studied. Polyhydroxyalkanoates (PHA were investigated as a bio sourced polymer due to its miscibility with the PEG. The result is compared to a standard formulation using polypropylene (PP. The chemical and rheological behavior of the binder formulation during mixing, injection and debinding process were investigated. The feedstock was characterized in the same way as the binders and the interactions between the powder and the binders were also studied. The results show the well adapted formulation of polymer binder to produce a superalloy Inconel 718 feedstock.

  8. The polyhydroxyalkanoate metabolism controls carbon and energy spillage in Pseudomonas putida.

    Science.gov (United States)

    Escapa, I F; García, J L; Bühler, B; Blank, L M; Prieto, M A

    2012-04-01

    The synthesis and degradation of polyhydroxyalkanoates (PHAs), the storage polymer of many bacteria, is linked to the operation of central carbon metabolism. To rationalize the impact of PHA accumulation on central carbon metabolism of the prototype bacterium Pseudomonas putida, we have revisited PHA production in quantitative physiology experiments in the wild-type strain vs. a PHA negative mutant growing under low nitrogen conditions. When octanoic acid was used as PHA precursor and as carbon and energy source, we have detected higher intracellular flux via acetyl-CoA in the mutant strain than in the wild type, which correlates with the stimulation of the TCA cycle and glyoxylate shunt observed on the transcriptional level. The mutant defective in carbon and energy storage spills the additional resources, releasing CO(2) instead of generating biomass. Hence, P. putida operates the metabolic network to optimally exploit available resources and channels excess carbon and energy to storage via PHA, without compromising growth. These findings demonstrate that the PHA metabolism plays a critical role in synchronizing global metabolism to availability of resources in PHA-producing microorganisms. © 2012 Society for Applied Microbiology and Blackwell Publishing Ltd.

  9. Microbial selection strategies for polyhydroxyalkanoates production from crude glycerol: Effect of OLR and cycle length.

    Science.gov (United States)

    Freches, André; Lemos, Paulo C

    2017-10-25

    Crude glycerol from biodiesel manufacture can be used as carbon source for microbial fermentations. The production of polyhydroxyalkanoates by manipulating the Sequencing Batch Reactor (SBR) selection stage of microbial mixed cultures (MMC) using high organic loading rates (OLR, 50CmM/day) and different cycles lengths (6, 12 and 24h) were optimized. Batch-production of polyhydroxybutyrate (PHB) presented an accumulation capacity in the high range (0.44g/g) after 3 pulses of 50CmM, with a final content of 59% PHB/wt., for the culture selected with 50CmM/day and a 24h cycle length. These values were in the range to those obtained with pure cultures and higher than the ones for MMC. With this strategy three main advantages in terms of the PHA production can be considered: utilization of a real waste without the resort to pure microbial cultures and a pre-fermentation step, consolidating the role of MMC in the valorisation of complex wastes/by-products. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Synthesis of High-Molecular-Weight Polyhydroxyalkanoates by Marine Photosynthetic Purple Bacteria.

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    Mieko Higuchi-Takeuchi

    Full Text Available Polyhydroxyalkanoate (PHA is a biopolyester/bioplastic that is produced by a variety of microorganisms to store carbon and increase reducing redox potential. Photosynthetic bacteria convert carbon dioxide into organic compounds using light energy and are known to accumulate PHA. We analyzed PHAs synthesized by 3 purple sulfur bacteria and 9 purple non-sulfur bacteria strains. These 12 purple bacteria were cultured in nitrogen-limited medium containing acetate and/or sodium bicarbonate as carbon sources. PHA production in the purple sulfur bacteria was induced by nitrogen-limited conditions. Purple non-sulfur bacteria accumulated PHA even under normal growth conditions, and PHA production in 3 strains was enhanced by nitrogen-limited conditions. Gel permeation chromatography analysis revealed that 5 photosynthetic purple bacteria synthesized high-molecular-weight PHAs, which are useful for industrial applications. Quantitative reverse transcription polymerase chain reaction analysis revealed that mRNA levels of phaC and PhaZ genes were low under nitrogen-limited conditions, resulting in production of high-molecular-weight PHAs. We conclude that all 12 tested strains are able to synthesize PHA to some degree, and we identify 5 photosynthetic purple bacteria that accumulate high-molecular-weight PHA molecules. Furthermore, the photosynthetic purple bacteria synthesized PHA when they were cultured in seawater supplemented with acetate. The photosynthetic purple bacteria strains characterized in this study should be useful as host microorganisms for large-scale PHA production utilizing abundant marine resources and carbon dioxide.

  11. Production of polyhydroxyalkanoates by Burkholderia cepacia ATCC 17759 using a detoxified sugar maple hemicellulosic hydrolysate.

    Science.gov (United States)

    Pan, Wenyang; Perrotta, Joseph A; Stipanovic, Arthur J; Nomura, Christopher T; Nakas, James P

    2012-03-01

    Sugar maple hemicellulosic hydrolysate containing 71.9 g/l of xylose was used as an inexpensive feedstock to produce polyhydroxyalkanoates (PHAs) by Burkholderia cepacia ATCC 17759. Several inhibitory compounds present in wood hydrolysate were analyzed for effects on cell growth and PHA production with strong inhibition observed at concentrations of 1 g/l furfural, 2 g/l vanillin, 7 g/l levulinic acid, and 1 M acetic acid. Gradual catabolism of lower concentrations of these inhibitors was observed in this study. To increase the fermentability of wood hydrolysate, several detoxification methods were tested. Overliming combined with low-temperature sterilization resulted in the highest removal of total inhibitory phenolics (65%). A fed-batch fermentation exhibited maximum PHA production after 96 h (8.72 g PHA/L broth and 51.4% of dry cell weight). Compositional analysis by NMR and physical-chemical characterization showed that PHA produced from wood hydrolysate was composed of polyhydroxybutyrate (PHB) with a molecular mass (M (N)) of 450.8 kDa, a melting temperature (T (m)) of 174.4°C, a glass transition temperature (T (g)) of 7.31°C, and a decomposition temperature (T (decomp)) of 268.6°C.

  12. Modification and Potential Application of Short-Chain-Length Polyhydroxyalkanoate (SCL-PHA

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    Shichao Wang

    2016-07-01

    Full Text Available As the only kind of naturally-occurring biopolyester synthesized by various microorganisms, polyhydroxyalkanoate (PHA shows a great market potential in packaging, fiber, biomedical, and other fields due to its biodegradablity, biocompatibility, and renewability. However, the inherent defects of scl-PHA with low 3HV or 4HB content, such as high stereoregularity, slow crystallization rate, and particularly the phenomena of formation of large-size spherulites and secondary crystallization, restrict the processing and stability of scl-PHA, as well as the application of its products. Many efforts have focused on the modification of scl-PHA to improve the mechanical properties and the applicability of obtained scl-PHA products. The modification of structure and property together with the potential applications of scl-PHA are covered in this review to give a comprehensive knowledge on the modification and processing of scl-PHA, including the effects of physical blending, chemical structure design, and processing conditions on the crystallization behaviors, thermal stability, and mechanical properties of scl-PHA.

  13. Perspectives on the production, structural characteristics and potential applications of bioplastics derived from polyhydroxyalkanoates.

    Science.gov (United States)

    Albuquerque, Priscilla B S; Malafaia, Carolina B

    2018-02-01

    Since the last two decades, the use of synthetic materials has increased and become more frequent in this capitalist system. Polymers used as raw materials are usually disposed very rapidly and considered serious damages when they return to the environment. Because of this behaviour, there was an increasing in the global awareness by minimizing the waste generated, in addition to the scientific community concern for technological alternatives to solve this problem. Alternatively, biodegradable polymers are attracting special interest due to their inherent properties, which are similar to the ones of the conventional plastics. Bioplastics covers plastics made from renewable resources, including plastics that biodegrade under controlled conditions at the end of their use phase. Polyhydroxyalkanoates (PHAs) are polyesters composed of hydroxy acids, synthesized by a variety of microorganisms as intracellular carbon and energy storage. These environmentally friendly biopolymers have excellent potential in domestic, agricultural, industrial and medical field, however their production on a large scale is still limited. This review considered the most recent scientific publications on the production of bioplastics based on PHAs, their structural characteristics and the exploitation of different renewable sources of raw materials. In addition, there were also considered the main biotechnological applications of these biopolymers. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Marine sponge-associated bacteria as a potential source for polyhydroxyalkanoates.

    Science.gov (United States)

    Sathiyanarayanan, Ganesan; Saibaba, Ganesan; Kiran, George Seghal; Yang, Yung-Hun; Selvin, Joseph

    2017-05-01

    Marine sponges are filter feeding porous animals and usually harbor a remarkable array of microorganisms in their mesohyl tissues as transient and resident endosymbionts. The marine sponge-microbial interactions are highly complex and, in some cases, the relationships are thought to be truly symbiotic or mutualistic rather than temporary associations resulting from sponge filter-feeding activity. The marine sponge-associated bacteria are fascinating source for various biomolecules that are of potential interest to several biotechnological industries. In recent times, a particular attention has been devoted to bacterial biopolymer (polyesters) such as intracellular polyhydroxyalkanoates (PHAs) produced by sponge-associated bacteria. Bacterial PHAs act as an internal reserve for carbon and energy and also are a tremendous alternative for fossil fuel-based polymers mainly due to their eco-friendliness. In addition, PHAs are produced when the microorganisms are under stressful conditions and this biopolymer synthesis might be exhibited as one of the survival mechanisms of sponge-associated or endosymbiotic bacteria which exist in a highly competitive and stressful sponge-mesohyl microenvironment. In this review, we have emphasized the industrial prospects of marine bacteria for the commercial production of PHAs and special importance has been given to marine sponge-associated bacteria as a potential resource for PHAs.

  15. Polyhydroxyalkanoate (PHA: Review of synthesis, characteristics, processing and potential applications in packaging

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    E. Bugnicourt

    2014-11-01

    Full Text Available Polyhydroxyalkanoates (PHAs are gaining increasing attention in the biodegradable polymer market due to their promising properties such as high biodegradability in different environments, not just in composting plants, and processing versatility. Indeed among biopolymers, these biogenic polyesters represent a potential sustainable replacement for fossil fuel-based thermoplastics. Most commercially available PHAs are obtained with pure microbial cultures grown on renewable feedstocks (i.e. glucose under sterile conditions but recent research studies focus on the use of wastes as growth media. PHA can be extracted from the bacteria cell and then formulated and processed by extrusion for production of rigid and flexible plastic suitable not just for the most assessed medical applications but also considered for applications including packaging, moulded goods, paper coatings, non-woven fabrics, adhesives, films and performance additives. The present paper reviews the different classes of PHAs, their main properties, processing aspects, commercially available ones, as well as limitations and related improvements being researched, with specific focus on potential applications of PHAs in packaging.

  16. Syngas obtained by microwave pyrolysis of household wastes as feedstock for polyhydroxyalkanoate production in Rhodospirillum rubrum.

    Science.gov (United States)

    Revelles, Olga; Beneroso, Daniel; Menéndez, J Angel; Arenillas, Ana; García, J Luis; Prieto, M Auxiliadora

    2017-11-01

    The massive production of urban and agricultural wastes has promoted a clear need for alternative processes of disposal and waste management. The potential use of municipal solid wastes (MSW) as feedstock for the production of polyhydroxyalkanoates (PHA) by a process known as syngas fermentation is considered herein as an attractive bio-economic strategy to reduce these wastes. In this work, we have evaluated the potential of Rhodospirillum rubrum as microbial cell factory for the synthesis of PHA from syngas produced by microwave pyrolysis of the MSW organic fraction from a European city (Seville). Growth rate, uptake rate, biomass yield and PHA production from syngas in R. rubrum have been analysed. The results revealed the strong robustness of this syngas fermentation where the purity of the syngas is not a critical constraint for PHA production. Microwave-induced pyrolysis is a tangible alternative to standard pyrolysis, because it can reduce cost in terms of energy and time as well as increase syngas production, providing a satisfactory PHA yield. © 2016 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

  17. Effect of gamma irradiation on cell lysis and polyhydroxyalkanoate produced by Bacillus flexus

    Science.gov (United States)

    Divyashree, M. S.; Shamala, T. R.

    2009-02-01

    Bacillus flexus cultivated on sucrose and sucrose with plant oil such as castor oil produced polyhydroxybutyrate (PHB), a homopolymer of polyhydroxyalkanoate (PHA) and PHA copolymer (containing hydroxybutyrate and hexanoate), respectively. Gamma irradiation of these cells (5-40 kGy) resulted in cell damage and aided in the isolation of 45% and 54% PHA on biomass weight, correspondingly. Molecular weight of PHB increased from 1.5×10 5 to 1.9×10 5 after irradiation (10 kGy), with marginal increase of tensile strength from 18 to 20 MPa. At the same irradiation dosage, PHA copolymer showed higher molecular weight increase from 1.7×10 5 to 2.3×10 5 and tensile strength from 20 to 35 MPa. GC, GC-MS, FTIR and 1H NMR were used for the characterization of PHA. Gamma irradiation seems to be a novel technique, to induce cross-linking and molecular weight increase of PHA copolymer and aid in easy extractability of intracellular PHA, simultaneously.

  18. Evaluation of short-chain-length polyhydroxyalkanoate accumulation in Bacillus aryabhattai

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    Aneesh Balakrishna Pillai

    Full Text Available Abstract This study was focused on the polyhydroxybutyrate (PHB accumulation property of Bacillus aryabhattai isolated from environment. Twenty-four polyhydroxyalkanoate (PHA producers were screened out from sixty-two environmental bacterial isolates based on Sudan Black B colony staining. Based on their PHA accumulation property, six promising isolates were further screened out. The most productive isolate PHB10 was identified as B. aryabhattai PHB10. The polymer production maxima were 3.264 g/L, 2.181 g/L, 1.47 g/L, 1.742 g/L and 1.786 g/L in glucose, fructose, maltose, starch and glycerol respectively. The bacterial culture reached its stationary and declining phases at 18 h and 21 h respectively and indicated growth-associated PHB production. Nuclear Magnetic Resonance (NMR spectra confirmed the material as PHB. The material has thermal stability between 30 and 140 °C, melting point at 170 °C and maximum thermal degradation at 287 °C. The molecular weight and poly dispersion index of the polymer were found as 199.7 kDa and 2.67 respectively. The bacterium B. aryabhattai accumulating PHB up to 75% of cell dry mass utilizing various carbon sources is a potential candidate for large scale production of bacterial polyhydroxybutyrate.

  19. Effect of gamma irradiation on cell lysis and polyhydroxyalkanoate produced by Bacillus flexus

    Energy Technology Data Exchange (ETDEWEB)

    Divyashree, M.S. [Department of Food Microbiology, Central Food Technological Research Institute, Mysore 570020 (India); Shamala, T.R. [Department of Food Microbiology, Central Food Technological Research Institute, Mysore 570020 (India)], E-mail: shamala_trs@yahoo.co.uk

    2009-02-15

    Bacillus flexus cultivated on sucrose and sucrose with plant oil such as castor oil produced polyhydroxybutyrate (PHB), a homopolymer of polyhydroxyalkanoate (PHA) and PHA copolymer (containing hydroxybutyrate and hexanoate), respectively. Gamma irradiation of these cells (5-40 kGy) resulted in cell damage and aided in the isolation of 45% and 54% PHA on biomass weight, correspondingly. Molecular weight of PHB increased from 1.5x10{sup 5} to 1.9x10{sup 5} after irradiation (10 kGy), with marginal increase of tensile strength from 18 to 20 MPa. At the same irradiation dosage, PHA copolymer showed higher molecular weight increase from 1.7x10{sup 5} to 2.3x10 {sup 5} and tensile strength from 20 to 35 MPa. GC, GC-MS, FTIR and {sup 1}H NMR were used for the characterization of PHA. Gamma irradiation seems to be a novel technique, to induce cross-linking and molecular weight increase of PHA copolymer and aid in easy extractability of intracellular PHA, simultaneously.

  20. Bacillus thuringiensis strain NG, a Novel Isolated Strain for production of Various Polyhydroxyalkanoates

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    Nazila Gholamveisi

    2017-12-01

    Full Text Available Introduction: Microbial biopolymers such as polyhydroxyalkanoates (PHA are proper alternatives for petroleum-derived plastics. These biopolymers have many advantages over conventional plastics such as biodegradability, environmental friendly and infinite as a renewable resource. Therefore, our study was aimed to isolate a bacterial strain capable of producing polyhydroxybutyrate (PHB; a highly applicable type of PHA. Materials and methods: To this aim, a total of 6 PHA-producing bacteria were isolated from waste water exit site of a brewery factory. The 6 isolates were studied by Sudan black-staining technique and the most stained isolate was selected for further studies. Next, the selected isolate was identified based on morphological, biochemical and phylogenetic analyses. Finally, the ability of strain in producing PHB as well as other PHAs was analyzed via GC-MS technique. Results: Strain NG had the highest yield of PHB, according to Sudan black-staining technique and it was selected for further studies. The strain NG was identified as a new strain of Bacillus thuringiensis. According to GC-MS results, this strain was able to produce PHB as well as 4 other PHAs including hexadecanoic acid methyl ester, octadecanoic acid methyl ester, tetradecanoic acid methyl ester, 8-octadecenoic acid methyl ester. Discussion and conclusion: It was the first report on producing various PHAs at the same time by a strain of Bacillus thuringiensis.

  1. Microbial production of polyhydroxyalkanoates (PHAs) and its copolymers: A review of recent advancements.

    Science.gov (United States)

    Anjum, Anbreen; Zuber, Mohammad; Zia, Khalid Mahmood; Noreen, Aqdas; Anjum, Muhammad Naveed; Tabasum, Shazia

    2016-08-01

    Traditional mineral oil based plastics are important commodity to enhance the comfort and quality of life but the accumulation of these plastics in the environment has become a major universal problem due to their low biodegradation. Solution to the plastic waste management includes incineration, recycling and landfill disposal methods. These processes are very time consuming and expensive. Biopolymers are important alternatives to the petroleum-based plastics due to environment friendly manufacturing processes, biodegradability and biocompatibility. Therefore use of novel biopolymers, such as polylactide, polysaccharides, aliphatic polyesters and polyhydroxyalkanoates is of interest. PHAs are biodegradable polyesters of hydroxyalkanoates (HA) produced from renewable resources by using microorganisms as intracellular carbon and energy storage compounds. Even though PHAs are promising candidate for biodegradable polymers, however, the production cost limit their application on an industrial scale. This article provides an overview of various substrates, microorganisms for the economical production of PHAs and its copolymers. Recent advances in PHAs to reduce the cost and to improve the performance of PHAs have also been discussed. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Polyhydroxyalkanoates from Pseudomonas sp. using synthetic and olive mill wastewater under limiting conditions.

    Science.gov (United States)

    Kourmentza, C; Ntaikou, I; Lyberatos, G; Kornaros, M

    2015-03-01

    The present study aimed at investigating the ability of bacteria isolated from an enriched mixed culture to produce polyhydroxyalkanoates (PHAs) and examining the effect of nitrogen and dual nitrogen-oxygen limitation on PHAs production, by using both synthetic and olive mill wastewater (OMW). PHAs production was performed through batch experiments using both the enriched culture and the isolated strains (belonging to the genus of Pseudomonas) aiming to compare PHAs accumulation capacity, yields and rates. The use of enriched culture and synthetic wastewater under nitrogen limitation resulted in the highest PHA accumulation, i.e. 64.4%gPHAs/g of cell dry mass (CDM). However, when OMW was used, PHAs accumulation significantly decreased, i.e. 8.8%gPHAs/g CDM. The same trend was followed by the isolated strains, nevertheless, their ability to synthesize PHAs was lower. Although, dual nitrogen-oxygen limitation generally slowed down PHAs biosynthesis, in certain strains PHAs production was positively affected. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Production of co-polymers of polyhydroxyalkanoates by regulating the hydrolysis of biowastes.

    Science.gov (United States)

    Kumar, Prasun; Ray, Subhasree; Kalia, Vipin C

    2016-01-01

    Production of polyhydroxyalkanoate (PHA) co-polymers by Bacillus spp. was studied by feeding defined volatile fatty acids (VFAs) obtained through controlled hydrolysis of various wastes. Eleven mixed hydrolytic cultures (MHCs) each containing 6 strains could generate VFA from slurries of (2% total solids): pea-shells (PS), potato peels (PP), apple pomace (AP) and onion peels (OP). PS hydrolysates (obtained with MHC2 and MHC5) inoculated with Bacillus cereus EGU43 and Bacillus thuringiensis EGU45 produced co-polymers of PHA at the rate of 15-60mg/L with a 3HV content of 1%w/w. An enhancement in PHA yield of 3.66-fold, i.e. 205-550mg/L with 3HV content up to 7.5%(w/w) was observed upon addition of OP hydrolysate and 1% glucose (w/v) to PS hydrolysates. This is the first demonstration, where PHA co-polymer composition, under non-axenic conditions, could be controlled by customizing VFA profile of the hydrolysate by the addition of different biowastes. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Biodegradable and Biocompatible Polyhydroxy-alkanoates (PHA: Auspicious Microbial Macromolecules for Pharmaceutical and Therapeutic Applications

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    Martin Koller

    2018-02-01

    Full Text Available Polyhydroxyalkanoates (PHA are bio-based microbial biopolyesters; their stiffness, elasticity, crystallinity and degradability are tunable by the monomeric composition, selection of microbial production strain, substrates, process parameters during production, and post-synthetic processing; they display biological alternatives for diverse technomers of petrochemical origin. This, together with the fact that their monomeric and oligomeric in vivo degradation products do not exert any toxic or elsewhere negative effect to living cells or tissue of humans or animals, makes them highly stimulating for various applications in the medical field. This article provides an overview of PHA application in the therapeutic, surgical and tissue engineering area, and reviews strategies to produce PHA at purity levels high enough to be used in vivo. Tested applications of differently composed PHA and advanced follow-up products as carrier materials for controlled in vivo release of anti-cancer drugs or antibiotics, as scaffolds for tissue engineering, as guidance conduits for nerve repair or as enhanced sutures, implants or meshes are discussed from both a biotechnological and a material-scientific perspective. The article also describes the use of traditional processing techniques for production of PHA-based medical devices, such as melt-spinning, melt extrusion, or solvent evaporation, and emerging processing techniques like 3D-printing, computer-aided wet-spinning, laser perforation, and electrospinning.

  5. Biosynthesis and Lipase-Catalysed Hydrolysis of 4-Hydroxybutyrate-Containing Polyhydroxyalkanoates from Delftia acidovorans

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    Diana Hooi-Ean Ch’ng

    2012-09-01

    Full Text Available Aims: Polyhydroxyalkanoates (PHA having various molar fractions of 4-hydroxybutyrate has been successfully synthesized by Delftia acidovorans.Methodology and results: The monomer compositions of the PHA were varied by cultivating the bacterium in a mixture of 1,4-butanediol and sodium valerate, γ-butyrolactone and sodium valerate as well as 4-hydroxybutyric acid and sodium valerate, which resulted in the production of PHA terpolymers. Although the highest terpolymer content achieved was only 57 wt% of the dry cell weight, the 4HB molar fractions can be regulated from 2-50 mol% when culture conditions such as initial pH, inoculum concentration and aeration were varied. The in vitro degradation of [P(3HB-co-50 % 4HB] synthesized by D. acidovorans were also studied by monitoring the erosion rate of the copolymer in aqueous solutions of lipases (Lipase A ‘Amano’ 12 and Newlase F. Results have shown that the types of lipases, concentration of lipase solution and pH of the buffer solution influenced the degradation rate of the PHA copolymer.Conclusion, significance and impact of the study: The overall results have shown that D. acidovorans is a very promising strain for the production of 4HB containing PHAs with specific compositions which are very suitable to be tailor made into biodegradable and biocompatible materials for medical applications.

  6. Influence of process variable and physicochemical properties on the granulation mechanism of mannitol in a fluid bed top spray granulator.

    Science.gov (United States)

    Bouffard, Jonathan; Kaster, Meagan; Dumont, Hubert

    2005-10-01

    This study investigated the influence of specific process variables, including the hydroxypropyl cellulose (HPC) binder solution atomization, on the fluidized bed top spray granulation of mannitol. Special attention was given to the relationship between wetting and the granule growth profile. The atomization of the HPC binder solution using a binary nozzle arrangement produced droplets of decreasing size as the atomization pressure was increased, while changes in the spray rate had little effect on the mean droplet size. Increasing the HPC binder concentration from 2 to 8% w/w increased the binder droplet size and was most likely attributed to higher solution viscosity. The top spray granulation of mannitol showed induction type growth behavior. Process conditions like high spray rate, low fluidizing air velocity and binder solution concentration that promote the availability of HPC binder solution at the surface of the particles appeared to be key in enhancing nucleation and growth of the granules. Increasing the bed moisture level, up to a certain value, reduced the contribution of attrition to the overall growth profile of the granule and, more significantly, produced less granule breakage on drying. It was observed that the mean granule size could be reduced as much as 40% between the end of granulation and the end of drying for lower initial bed moisture level despite a shorter drying phase. High atomization pressure, especially when maintained during the drying phase, contributed substantially to granule breakage.

  7. Rheological and fractal hydrodynamics of aerobic granules.

    Science.gov (United States)

    Tijani, H I; Abdullah, N; Yuzir, A; Ujang, Zaini

    2015-06-01

    The structural and hydrodynamic features for granules were characterized using settling experiments, predefined mathematical simulations and ImageJ-particle analyses. This study describes the rheological characterization of these biologically immobilized aggregates under non-Newtonian flows. The second order dimensional analysis defined as D2=1.795 for native clusters and D2=1.099 for dewatered clusters and a characteristic three-dimensional fractal dimension of 2.46 depicts that these relatively porous and differentially permeable fractals had a structural configuration in close proximity with that described for a compact sphere formed via cluster-cluster aggregation. The three-dimensional fractal dimension calculated via settling-fractal correlation, U∝l(D) to characterize immobilized granules validates the quantitative measurements used for describing its structural integrity and aggregate complexity. These results suggest that scaling relationships based on fractal geometry are vital for quantifying the effects of different laminar conditions on the aggregates' morphology and characteristics such as density, porosity, and projected surface area. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. The biology and dynamics of mammalian cortical granules

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    Liu Min

    2011-11-01

    Full Text Available Abstract Cortical granules are membrane bound organelles located in the cortex of unfertilized oocytes. Following fertilization, cortical granules undergo exocytosis to release their contents into the perivitelline space. This secretory process, which is calcium dependent and SNARE protein-mediated pathway, is known as the cortical reaction. After exocytosis, the released cortical granule proteins are responsible for blocking polyspermy by modifying the oocytes' extracellular matrices, such as the zona pellucida in mammals. Mammalian cortical granules range in size from 0.2 um to 0.6 um in diameter and different from most other regulatory secretory organelles in that they are not renewed once released. These granules are only synthesized in female germ cells and transform an egg upon sperm entry; therefore, this unique cellular structure has inherent interest for our understanding of the biology of fertilization. Cortical granules are long thought to be static and awaiting in the cortex of unfertilized oocytes to be stimulated undergoing exocytosis upon gamete fusion. Not till recently, the dynamic nature of cortical granules is appreciated and understood. The latest studies of mammalian cortical granules document that this organelle is not only biochemically heterogeneous, but also displays complex distribution during oocyte development. Interestingly, some cortical granules undergo exocytosis prior to fertilization; and a number of granule components function beyond the time of fertilization in regulating embryonic cleavage and preimplantation development, demonstrating their functional significance in fertilization as well as early embryonic development. The following review will present studies that investigate the biology of cortical granules and will also discuss new findings that uncover the dynamic aspect of this organelle in mammals.

  9. Roll compaction and granulation system for nuclear fuel material

    International Nuclear Information System (INIS)

    Goldmann, L.H. Jr.; Holley, C.C.

    1981-01-01

    A roll compaction and roll granulation system has been designed and fabricated to replace conventional preslugging and crushing operations typically used in the fabrication of mixed oxide nuclear fuel pellets. This equipment will be of maintenance advantage with only the compaction and granulation rolls inside containment. The prototype is being tested and the results will be reported within a year

  10. Proximate analysis of Sweet Potato Toasted Granules | Meludu ...

    African Journals Online (AJOL)

    Sweet potato is an important root crop in the food system of many African countries. The yield, nutrition and economic potential of sweet potato have been identified as very high. In this study, sweet potato was processed and toasted into granules. The proximate analysis performed on the toasted granules showed protein, ...

  11. Investigation of Compost Fertilizer Granulation Parameters Using Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Y Ghasemi

    2015-03-01

    Full Text Available Nowadays compost fertilizers are suitable alternative to chemical fertilizers, due to the threats for human health and agriculture products. The most important problems for applying the compost fertilizer in the farm are: transportation (high volume, high moisture content, spreading problem, impurity such as dust and storage. To solve the problems mentioned, pressing process such as converting the compost to pellets and granules are suggested. In this research the effects of some granulation parameters on the percent of useful granules in a laboratory scale rotating drum was evaluated. The percentage of useful granules decreased by increasing the granulation time and increased by increasing the percentage of drum filling. The optimal conditions for granules production was achieved at drum rotational speed of 40.38 rpm, granulation time of 15 min, drum filling of 10% and molasse percentage of 40.97. According to these conditions, the response for useful granule was estimated as 81.6% with R2 of 0.924.

  12. Granule properties of paracetamol made with Bombax ceiba gum ...

    African Journals Online (AJOL)

    Bombax ceiba gum was extracted from the calyx of the Bombax flower using both hot and cold water extraction method. The gum was used as binder to prepare paracetamol granules in concentrations of 1, 1.5, 2, and 3 %. Acacia gum was used to prepare the standard at the same concentrations. The granule properties of ...

  13. Internal structure and fragmentation kinetics of silica granules

    Science.gov (United States)

    Grosseau, P.; Dumas, T.; Bonnefoy, O.; Barriquand, L.; Guy, L.; Thomas, G.

    2013-06-01

    To improve the mechanical properties of tires, silica granules can be incorporated into the elastomer as well as carbon black. Ideally, the fragmentation of the granules in the elastomer must be obtained with low mechanical stresses and lead to very small fragments distributed homogeneously in the material. On the other hand, granules must present a sufficient cohesion, in order to avoid the generation of fine particles during handling operations. Thus it appears necessary to control the mechanical strength of granules and the mechanism of their fragmentation. In this experimental study, we investigated the fragmentation of silica granules of 250 microns produced by spray drying. For this, we characterized by granulometry the evolution of the Particle Size Distribution of silica powder in water. The granules were suspended in water and submitted to ultrasounds. This treatment is used to create the fragmentation that occurs by viscous shearing in industrial rubber processing. A core-shell structure, characteristic of granules obtained by atomization process, was observed by SEM. Furthermore, by varying the intensity of mechanical stress, the multi-scale structure of granules was evidenced as well as the existence of different regimes of fragmentation. The kinetics of fragmentation was experimentally followed on two grades of silica that showed significant differences in their behavior during the fragmentation process.

  14. Bone growth response with porous hydroxyapatite granules in a ...

    Indian Academy of Sciences (India)

    This study evaluated the tissue reaction to porous hydroxyapatite (HA) granules in a critical sized tibial-defect of New Zealand white rabbits for a period of 2, 6, 12 and 24 weeks. Physicochemical characterizations of the granules were done using transmission electron microscopy, scanning electron microscopy, X-ray ...

  15. Application of granulating of tires; Aplicaciones de granulado de NFUs

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez Justicia, A.

    2001-07-01

    At present, used tires are mainly used as fuel, retreading and granulating of tires. In this article. I will focus on the last option, talking about some of the multiple applications and going into detail of the making process of the granulation of used tires in a recycling plant. (Author)

  16. Experimental study of wet granulation in fluidized bed: impact of the binder properties on the granule morphology.

    Science.gov (United States)

    Rajniak, P; Mancinelli, C; Chern, R T; Stepanek, F; Farber, L; Hill, B T

    2007-04-04

    In this work, the effect of the physicochemical properties of aqueous hydroxypropyl-cellulose (HPC) binder solutions and different pharmaceutical excipients (mannitol and anhydrous CaHPO(4)) on the agglomeration kinetics and granule properties were investigated. First, a particle size distribution (PSD) analysis together with a detailed analysis of morphological properties of the excipient particles were performed. Second, the viscosity, density, surface tension and size of the spray droplets of binder solutions with different HPC concentrations were determined and wetting characteristics of the binders on the excipients were measured. Third, several fluid bed wet granulation experiments were conducted for pure excipients and their blends with binder solution of different HPC concentrations in a pilot plant Wurster granulator. The observed granule growth for different binder concentrations was a strong function of the binder concentration and the excipient solubility. For mannitol, a significant "coating" period followed by a slow granule growth was observed for the case with the diluted 5% binder. The "coating" period was significantly shorter for the 10% HPC binder and did not exist for the 15% HPC for which immediate and fast granule growth was observed. For anhydrous CaHPO(4) (trademark A-TAB), no growth was observed for the 10% HPC binder and a long coating period followed by fast granule growth was observed for the 15% HPC. Simple physically based criteria were also evaluated, which employ the morphological properties of excipients (size and surface roughness) together with physical properties of the used binder for prediction of the coating versus agglomeration regime at given flow conditions (collision velocity). As expected, a preferential coalescence and growth of the mannitol granules from the blend of mannitol+A-TAB was observed. Finally, the mechanical and morphological properties of the produced granules were measured and correlated to the HPC

  17. Understanding and predicting bed humidity in fluidized bed granulation.

    Science.gov (United States)

    Hu, Xinhui; Cunningham, John; Winstead, Denita

    2008-04-01

    Bed humidity is a critical parameter that needs to be controlled in a fluidized bed granulation to ensure reliability. To predict and control the bed humidity during the fluidized bed granulation process, a simple model based on the mass conservation of moisture was developed. The moisture mass balance model quantitatively simulates the effects of spray rate, binder solution concentration, airflow rate, inlet air temperature, and dew point on the bed humidity. The model was validated by a series of granulations performed in different scale granulators including Glatt GPCG-1, GPCG-15, and GPCG-60. Good agreement was observed between the theoretical prediction and the measured loss on drying (LOD). The model developed in the current work enables us to choose the appropriate parameters for the fluidized bed granulation and can be used as a valuable tool in process scaling-up. 2007 Wiley-Liss, Inc

  18. Compressional Behavior of a Mixture of Granules Containing High Load of Phyllanthus niruri Spray-Dried Extract and Granules of Adjuvants: Comparison between Eccentric and Rotary Tablet Machines

    OpenAIRE

    Spaniol, Bárbara; Bica, Vinicius Claudino; Ruppenthal, Lisias Rafael; Volpato, Maria Ramos; Petrovick, Pedro Ros

    2009-01-01

    The purpose of this paper was to evaluate the compressional behavior of granules containing high load of a Phyllanthus niruri spray-dried extract in eccentric (ETM) and rotary (RTM) tablet presses. Tablets were constituted by spray-dried extract granules (SDEG, 92%), excipient granules (EXCG, 7.92%), and magnesium stearate (0.08%). SDEG was obtained by dry granulation and EXCG, composed of microcrystalline cellulose (62.9%) and sodium starch glycolate (37.1%), by wet granulation. Particle siz...

  19. A review on granules initiation and development inside UASB Reactor and the main factors affecting granules formation process

    Energy Technology Data Exchange (ETDEWEB)

    Habeeb, S.A.; Latiff, Ab Aziz Bin Abdul; Daud, Zawawi Bin; Ahmad, Zulkifli Bin [Civil and Environmental Engineering, University Tun Hussein Onn Malaysia (Malaysia)

    2011-07-01

    Decades of investigations and explorations in the field of anaerobic wastewater treatment have resulted in significant indications about the role importance of sludge granules in biodegradation anaerobic process. It is believed that the development of anaerobic granules is reflecting an important role on the performance of reactor. An overview on the concept of up-flow anaerobic sludge bed (UASB) reactor operation as well as the main parts that reactor consists of is briefly explained in this paper, whereas the major theories of anaerobic granules formation are listed by related researchers. The correlations and compositions of such sludge granule have been specifically explained. It is believed that the extracellular polymer (ECP) is totally responsible of bacterial cell correlations and the formation of bacterial communities in the form of granules. In addition, the dependable factors for the performance of anaerobic granules formation process e.g. temperature, organic loading rate, pH, and alkalinity, nutrients, and cations and heavy metals have been discussed in this paper. Strong evidences proved that the process of gas production in the form of biogas is related to the methanogens activities, which are practically found in the core of granules. The aim of this review is to explore and assess the mechanisms of granules initiation and development inside UASB reactor.

  20. The effect of the physical state of binders on high-shear wet granulation and granule properties: a mechanistic approach to understand the high-shear wet granulation process. part IV. the impact of rheological state and tip-speeds.

    Science.gov (United States)

    Li, Jinjiang; Tao, Li; Buckley, David; Tao, Jing; Gao, Julia; Hubert, Mario

    2013-12-01

    The purpose of this study is to provide a mechanistic understanding concerning the effect of tip-speed on a granulation at various binder rheological states; the in situ rheological state of a binder was controlled by exposing a granulation blend to 96% relative humidity. This approach allowed us to investigate the impact of tip-speed on granule consolidation coupled with the in situ binder state, which was not possible using a conventional granulation approach. Experimentally, the rheological state of binders was characterized using a rheometer. Granule size and granule porosity were measured by Qicpic instrument and Mercury Intrusion Porosimetry, respectively. For the granulations containing binders at viscous state (PVP K17 and PVP K29/32), the granule size increased significantly with mixing time and the growth rate increased with tip-speed until 5.8 m/s; when binders were at viscoelastic state, tip-speed had no impact on granulation. Furthermore, the granule porosity was higher for granulation with binders at viscoelastic state (HPC and PVP K90), whereas it was lower for granulation with binders at viscous state. In addition, the impeller tip-speed had minimal impact on the porosity of the final granules. Finally, Ennis' model was used for interpreting results, providing mechanistic insights on granulation. © 2013 Wiley Periodicals, Inc. and the American Pharmacists Association.

  1. Microbial granulation for lactic acid production

    DEFF Research Database (Denmark)

    Kim, Dong-Hoon; Lee, Mo-Kwon; Hwang, Yuhoon

    2016-01-01

    was fed with 2% glucose and operated at a hydraulic retention time (HRT) of 12 h and pH 5.0 ± 0.1 under a thermophilic condition (50°C). The mixed liquor in the CSTR was then transferred to an up-flow anaerobic sludge blanket reactor (UASB). The fermentation performance and granulation process were...... monitored with a gradual decrease of HRT from 8.0 to 0.17 h, corresponding to an increase in the substrate loading from 60 to 2,880 g glucose L−1d−1. As the operation continued, the accumulation of biomass in the UASB was clearly observed, which changed from flocculent to granular form with decrease in HRT...

  2. Variation analysis of bacterial polyhydroxyalkanoates production using saturated and unsaturated hydrocarbons

    Directory of Open Access Journals (Sweden)

    Saiqa Tufail

    Full Text Available ABSTRACT Polyhydroxyalkanoates (PHA are efficient, renewable and environment friendly polymeric esters. These polymers are synthesized by a variety of microbes under stress conditions. This study was carried out to check the suitability of waste frying oil in comparison to other oils for economical bioplastic production. Six bacterial strains were isolated and identified as Bacillus cereus (KF270349, Klebsiella pneumoniae (KF270350, Bacillus subtilis (KF270351, Brevibacterium halotolerance (KF270352, Pseudomonas aeruginosa (KF270353, and Stenotrophomonas rhizoposid (KF270354 by ribotyping. All strains were PHA producers so were selected for PHA synthesis using four different carbon sources, i.e., waste frying oil, canola oil, diesel and glucose. Extraction of PHA was carried out using sodium hypochlorite method and maximum amount was detected after 72 h in all cases. P. aeruginosa led to maximum PHA production after 72 h at 37 °C and 100 rpm using waste frying oil that was 53.2% PHA in comparison with glucose 37.8% and cooking oil 34.4%. B. cereus produced 40% PHA using glucose as carbon source which was high when compared against other strains. A significantly lesser amount of PHA was recorded with diesel as a carbon source for all strains. Sharp Infrared peaks around 1740-1750 cm-1 were present in Fourier Transform Infrared spectra that correspond to exact position for PHA. The use of waste oils and production of poly-3hydroxybutyrate-co-3hydroxyvalerate (3HB-co-3HV by strains used in this study is a good aspect to consider for future prospects as this type of polymer has better properties as compared to PHBs.

  3. Commercialization of bacterial cell factories for the sustainable production of polyhydroxyalkanoate thermoplastics: progress and prospects.

    Science.gov (United States)

    Kumar, Abhishek; Srivastava, Janmejai K; Mallick, Nirupama; Singh, Akhilesh K

    2015-01-01

    Ubiquitous conventional plastics, generally manufactured from finite, nonsustainable fossil fuels are non-biodegradable wonder entities but their ill effect on Mother Nature has subsequently raised major environmental concerns like their safe disposal, solid waste management and several potential hazards. Such concerns have fuelled initiatives for research globally towards development of sustainable and eco-friendly bioplastics. The new generation of plastics called 'bioplastics' are polymers of long chain of repeating monomer units that are classified as photodegradable, semi-biodegradable, chemically synthesized and polyhydroxyalkanoates (PHAs). The commonly emerged novel bioplastics are polyesters of hydroxyalkanoates (HAs) called PHAs, which are lipoidic storage materials found in the cytosol of vast and diverse forms of bacteria. Among 150 different PHAs known so far, poly- 3-hydroxybutyrate is the most common and comprehensively characterized PHA. Interestingly, PHAs are only completely biodegradable plastics with material properties comparable to conventional plastics that can be achieved by regulating the co-monomers incorporation into PHAs backbone. PHA bioplastics are exploited in the form of user-friendly goods viz. films, absorbable sutures, bone plates, drug carriers, etc. Besides advantages, such useful entity(s) has major shortcomings as well like high production cost compared to conventional plastics. Precisely, in PHAs production, about fifty percent of the overall price is due to the carbon substrates. Consequently, exploring novel cost-effective substrates is a major compulsion for successful commercialization of this bioplastic, which is anticipated to reduce the cost of production as a result of advancing and intensifying research work. This review presents an insight and patent developments in the field of PHAs bioplastics.

  4. Production and Characterization of Polyhydroxyalkanoates and Native Microorganisms Synthesized from Fatty Waste

    Directory of Open Access Journals (Sweden)

    Javier Ricardo Gómez Cardozo

    2016-01-01

    Full Text Available Polyhydroxyalkanoates (PHAs are biodegradable and biocompatible plastics. They are synthesized by a wide variety of microorganisms (i.e., fungi and bacteria and some organisms such as plants, which share characteristics with petrochemical-based plastics. The most recent studies focus on finding inexpensive substrates and extraction strategies that allow reducing product costs, thus moving into a widespread market, the market for petroleum-based plastics. In this study, the production of polyhydroxybutyrate (PHB was evaluated using the native strains, Bacillus megaterium, Bacillus sp., and Lactococcus lactis, and glycerol reagent grade (GRG, residual glycerol (RGSB byproduct of biodiesel from palm oil, Jatropha oil, castor oil, waste frying oils, and whey as substrates. Different bacteria-substrate systems were evaluated thrice on a laboratory scale under different conditions of temperature, pH, and substrate concentration, employing 50 mL of broth in 250 mL. The bacterial growth was tested in all systems; however, the B. megaterium GRG system generated the highest accumulation of PHA. The previous approach was allowed to propose a statistical design optimization with RGSB (i.e., RGSB, 15 g/L, pH 7.0, and 25°C. This system reached 2.80 g/L of PHB yield and was the optimal condition tested; however, the optimal biomass 5.42 g/L occurs at pH 9.0 and 25°C, with a substrate concentration of 22 g/L.

  5. Agrowaste-based Polyhydroxyalkanoate (PHA production using hydrolytic potential of Bacillus thuringiensis IAM 12077

    Directory of Open Access Journals (Sweden)

    Vaishnavi Gowda

    2014-02-01

    Full Text Available The study identified the innate enzymatic potential (amylase of the PHB producing strain B.thuringiensis IAM 12077 and explored the same for cost-effective production of PHB using agrowastes, eliminating the need for pretreatment (acid hydrolysis and/or commercial enzyme. Comparative polyhydroxyalkanoate (PHA production by B. thuringiensis IAM 12077 in biphasic growth conditions using glucose and starch showed appreciable levels of growth (5.7 and 6.8 g/L and PHA production (58.5 and 41.5% with a PHA yield of 3.3 and 2.8 g/L, respectively. Nitrogen deficiency supported maximum PHA yield (2.46 g/L and accumulation (53.3%. Maximum growth (3.6 g/L, PHB yield (2.6 g/L and PHA accumulation (72.8% was obtained with C:N ratio of 8:1 using starch as the carbon source (10 g/L. Nine substrates (agro and food wastes viz. rice husk, wheat bran, ragi husk, jowar husk, jackfruit seed powder, mango peel, potato peel, bagasse and straw were subjected to two treatments- acid hydrolysis and hydrolysis by innate enzymes, and the reducing sugars released thereby were utilized for polymer production. All the substrates tested supported comparable PHB production with acid hydrolysis (0.96 g/L-8.03 g/L and enzyme hydrolysis (0.96 g/L -5.16 g/L. Mango peel yielded the highest PHB (4.03 g/L; 51.3%, followed by jackfruit seed powder (3.93 g/L; 29.32%. Varied levels of amylase activity (0.25U-10U in all the substrates suggested the enzymatic hydrolysis of agrowastes.

  6. Intracellular organisation of polyhydroxyalkanoate inclusion bodies: a role for small angle neutron scattering?

    International Nuclear Information System (INIS)

    Foster, L.J.R.; Holden, P.J.; Garvey, C.J.; Russell, R.A.; Stone, D.J.M.

    2003-01-01

    Full text: Polyhydroxyalkanoates (PHAs) are a diverse family of bacterially produced biopolyesters. Their biodegradability, and in some cases biocompatibility, suggest applications ranging from bioplastics to biomedical implantation devices. Despite extensive interest in their production and potential applications, little is known about their intracellular organisation. Microbial PHAs are synthesised by microorganisms under conditions of nutrient stress and can comprise up to 90% of the dry cell mass. The formation and organisation of these PHA inclusion bodies requires clarification. Such investigations have important implications for the biotechnological production of PHAs in microbes and other organisms, for downstream processing and in vitro precision polymerisation. Morphological and biochemical evidence supports two different models for the intracellular organisation of PHAs. Steinbuchel and coworkers propose a simple model of amorphous PHA enclosed by a single protein membrane consisting of structural proteins (PHAsins) and enzymes responsible for synthesis and degradation. In contrast, Fuller and coworkers have theorised a more complex system of PHA encompassed by a PHAsin bilayer separated by phospholipid. The polymerase and depolymerase enzymes are proposed to be associated with an incomplete inner PHAsin layer. It may be that such models are genera or species specific, since both proposals were derived from research on different species producing different types of PHA. Our initial investigations have focussed on in vivo deuteration of polyhydroxyoctanoate, produced by Pseudomonas oleovorans, both in fermentation on natural and deuterated substrates and during Small Angle Neutron Scattering by whole cells using AUSANS. The nature of the structural questions and our preliminary findings including contrast variation data will be discussed

  7. Evaluation of Factors Affecting Polyhydroxyalkanoates Production by Comamonas sp. EB172 Using Central Composite Design

    Directory of Open Access Journals (Sweden)

    Noor Azman Mohd Johar

    2012-09-01

    Full Text Available Aims: Statistical approach, central composite design (CCD was used to investigate the complex interaction among temperature (25-37 °C, initial medium pH (5-9, inoculum size (4-10 % (v/v, concentration of (NH42SO4 (0-1 g/L and concentration of mixed organic acids (5-10 g/L in the production of polyhydroxyalkanoates by Comamonas sp. EB172.Methodology and Results: Mixed organic acids derived from anaerobically treated palm oil mill effluent (POME containing acetic:propionic:butyric (ratio of 3:1:1 were used as carbon source in the batch culture of Comamonas sp. EB172 to produce polyhydoxyalkanoates (PHAs. The analysis of variance (ANOVA showed that all five factors were significantly important in the batch fermentation by shake flask with a P value of less than 0.001. The optimal temperature, initial medium pH, inoculum size, concentration of (NH42SO4 and concentration of mixed organic acids were 30 °C, 7.04, 4.0 % (v/v, 0.01 g/L and 5.05 g/L respectively.Conclusion, significance and impact of study: Optimization of the production medium containing mixed organic acids has improved the PHA production for more than 2 folds. Under optimal condition in the shake flask fermentation, the predicted growth is 2.98 g/L of dry cell weight (DCW with 47.07 wt % of PHA content. The highest yield of PHA was 0.28 g of PHA per g mixed organic acids.

  8. Effect of Magnetic Field on the Type and Amount of Monomers in Polyhydroxyalkanoate Copolymer

    Directory of Open Access Journals (Sweden)

    Marzie Fatehi

    2014-10-01

    Full Text Available Many studies have been conducted on production of biodegradable polymers such as polyhydroxyalkanoates (PHAs in overcoming the environmental problems due to the accumulation of synthetic plastics as waste materials and excessive activated sludge produced in municipal waste water treatment plants. In this study; the effect of magnetic field intensity of 5, 10, 15, 20, 25 and 50 milliTesla (mT was investigated on the type and amount of monomers produced in the copolymer and PHA production in activated sludge and the results were compared simultaneously with the results of PHA production without the magnetic field (0 mT. The experimental procedure included the transfer of the activated sludge into the batch reactor, addition of sodium acetate, magnetic field generation by magnets, aeration for 30 h, sampling at definite timing, measurement of PHA by gas chromatography. In summary, this research indicated that, the maximum PHA content was produced at 20 mT which was equal to 0.75 g/L, whereas the lowest PHA content was observed at 50 mT (0.55 g/L. In addition, the magnetic field was influenced by the type and amount of monomer produced in PHA. The highest amount of valerate was observed at 50 mT, while this magnetic field decreased the amount of PHA (8.33% compared to the control sample. Also, the maximum amount of butyrate monomer in the copolymer was observed at 5 and 20 mT, which were equal to 81% and 74 %. According to the results obtained, the mass percentage of valerate in the control sample and those exposed to magnetic field with negative effects was more than the mass percentage of butyrate; an indication of better copolymers on the basis of their mechanical properties.

  9. Microbial synthesis of polyhydroxyalkanoate using seaweed-derived crude levulinic acid as co-nutrient.

    Science.gov (United States)

    Bera, Anupam; Dubey, Sonam; Bhayani, Khushbu; Mondal, Dibyendu; Mishra, Sandhya; Ghosh, Pushpito K

    2015-01-01

    Production of polyhydroxyalkanoates (PHAs) from Jatropha biodiesel residues, namely crude glycerol and oil cake hydrolysate, has been reported previously. Halomonas hydrothermalis (MTCC accession no. 5445; NCBI Genbank accession no. GU938192), a wild marine strain, was used in the bio-synthesis. The present study was initiated to vary the properties of the polymer. Seaweed-derived crude levulinic acid (SDCLA), containing formic acid, residual sugars and dissolved minerals additionally, was proposed as co-feed along with the biodiesel residues. Experiments were conducted at 100mL scale in batch process. Whereas the PHA yield was only 0.40 ± 0.01 g when only biodiesel residues were employed, it rose to 1.07 ± 0.02 g in presence of 0.35% (w/v) of SDCLA. The corresponding carbon utilisation efficiencies were 29.3% and 57.5%, respectively. 3-Hydroxy valerate incorporation in the PHA was pronounced in presence of SDCLA, with associated changes in polymer properties. The microbial synthesis fared poorly when SDCLA was substituted with pure levulinic acid. Thus, Halomonas hydrothermalis had a poor response to levulinic acid, as such, and other constituents present in SDCLA appear to have played a vital role in bacterial cell division and accumulation of PHA. Biodegradability tests in moist soil were also conducted as part of the study. Marine microalgal cultivation for biodiesel and seaweed cultivation for fuels may help generate biodiesel residues and crude levulinic acid in proximity, which would open up the possibility of large scale PHA manufacture in efficient and practical manner in the future through the methodology of the present study. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Poly(hydroxyalkanoates for Food Packaging: Application and Attempts towards Implementation

    Directory of Open Access Journals (Sweden)

    M. Koller

    2014-09-01

    Full Text Available Plastics are well-established for convenient and safe packaging and distribution of food and feed goods. At present, this special sector of the plastic market displays remarkably increasing quantities of its annual production. Caused by the ongoing limitation and strongly fluctuating prices of fossil feedstocks, classically used for plastic production, there is an evident trend to switch towards so-called “bio-plastics”. Especially for bulk applications such as food packaging, a broad implementation of “bio-plastics” constitutes a future-oriented strategy to restrict the dependence of global industry on fossil feedstocks, and to diminish current problematic environmental issues arising from plastic disposal. However, food packaging demands a great deal of the utilized packaging material. This encompasses tailored mechanical properties such as low brittleness and adequate tensile strength, a sufficient barrier for oxygen, CO2, and aromatic flavors, high UV-resistance, and high water retention-capacity to block the food´s moisture content, or to prevent humidity, respectively. Due to their hydrophobic character and the broad flexibility of their mechanical features, prokaryotic poly(hydroxyalkanoates (PHAs are considered as promising materials to compete with petro-plastics on the food-packaging market. Nevertheless, short-comings in particular aspects of their material performance and economics of their biosynthesis and purification constitute stumbling blocks on the long way towards broad implementation of PHAs for food packaging. This article discusses advantages and drawbacks of PHAs as food packaging materials, and demonstrates how desired properties can be improved by the designing of novel composite materials, and also encompassing techniques by applying nanoparticles.

  11. The Solar-flux Third Granulation Signature

    Science.gov (United States)

    Gray, David F.; Oostra, Benjamin

    2018-01-01

    The velocity shifts of spectral lines as a function of line strength, so-called the third signature of granulation, are investigated using three published solar-flux atlases. We use flux atlases because we wish to treat the Sun as a star, against which stellar observations can be compared and judged. The atlases are critiqued and compared to the lower-resolution observations taken with the Elginfield stellar spectrograph. Third-signature plots are constructed for the 6020–6340 Å region. No dependence on excitation potential or wavelength is found over this wavelength span. The shape of the plots from the three solar atlases is essentially the same, with rms line-core velocity differences of 30–35 m s‑1. High-resolution atlas data are degraded to the level of the Elginfield spectrograph and compared to direct observations taken with that spectrograph. The line-core velocities show good agreement, with rms differences of 38 m s‑1. A new standard curve is derived and compared with the previously published one. Only small differences in shape are found, but a significant (+97 m s‑1) change in the zero point is indicated. The bisector of the Fe I 6253 line is mapped onto the third-signature plots and flux deficits are derived, which measure the granule/lane flux imbalance. The lower spectral resolution lowers the flux deficit area slightly and moves the peak of the deficit 0.3–0.5 km s‑1 toward higher velocities. These differences, while significant, are not large compared to measurement errors for stellar data.

  12. Ocular Injury due to Potassium Permanganate Granules

    Directory of Open Access Journals (Sweden)

    Chareenun Chirapapaisan

    2018-02-01

    Full Text Available Purpose: We report a rare case of ocular injury due to potassium permanganate (KMnO4 granules in a child. Methods: This is a retrospective case report. Results: A 2-year-old boy was transferred to our emergency room with severe pain in his right eye, inflamed eyelids, and brownish stains on his fingers. Chemical injury was suspected. Copious eye irrigation was immediately performed. Diffuse brownish splotches were then observed at the inferior bulbar conjunctiva. Otherwise, systemic organs were intact. Complete eye exam under general anesthesia revealed a 5-mm epithelial defect at the central cornea, along with generalized conjunctival injection and limbal ischemia, inferiorly. Multiple semi-dissolved granules of KMnO4 trapped in the inferior fornix were identified. The chemical particles were gradually washed out and removed; however, the brownish stains remained. The patient received preservative-free steroid, antibiotic eye drops, and lubricants as regular management for mild to moderate degree of ocular burn. Pseudomembrane developed early and transformed into symblepharon within a few days after the injury. Membrane adhesion was lysed, and more aggressive medications were then substituted. Commercial amniotic membrane (PROKERA® was also applied to promote wound healing and to prevent recurrence of symblepharon. The ocular surface was eventually restored, and corneal transparency was preserved. Conclusion: Ocular injury with the granular form of KMnO4 is rare. Its toxicity is comparable to concentrated KMnO4 solution. However, the dissolved particles that had been absorbed in the stained conjunctiva were continuously released and damaged the ocular surface more than we primarily anticipated. Awareness of this condition and prompt management yield a good treatment outcome.

  13. Evolution of granule structure and drug content during fluidized bed granulation by X-ray microtomography and confocal Raman spectroscopy.

    Science.gov (United States)

    Poutiainen, Sami; Pajander, Jari; Savolainen, Armi; Ketolainen, Jarkko; Järvinen, Kristiina

    2011-12-01

    The distribution of the drug in the granular end product is a critical quality attribute in fluidized bed spray granulation of pharmaceuticals. The evolution of drug content inhomogeneity in a case study was examined as a function of granulation time. Intragranular structure was also investigated using confocal Raman spectroscopy and computerized X-ray microtomography. A principal component analysis was conducted on the results to investigate granule structure-drug content relationships. Inhomogeneity increased at the beginning of the process but later it was found to decrease. Changes in the homogeneity were accompanied by significant changes in the intragranular structure. It was concluded that segregation of the primary components explained the observed inhomogeneity at low saturation levels when the granules grow by layering, but at elevated moisture levels, granule growth is mediated by the coalescence of agglomerates, which promotes homogeneous distribution of the drug particles. Copyright © 2011 Wiley-Liss, Inc.

  14. Cerebellar granule cells are predominantly generated by terminal symmetric divisions of granule cell precursors.

    Science.gov (United States)

    Nakashima, Kie; Umeshima, Hiroki; Kengaku, Mineko

    2015-06-01

    Neurons in the central nervous system (CNS) are generated by symmetric and asymmetric cell division of neural stem cells and their derivative progenitor cells. Cerebellar granule cells are the most abundant neurons in the CNS, and are generated by intensive cell division of granule cell precursors (GCPs) during postnatal development. Dysregulation of GCP cell cycle is causal for some subtypes of medulloblastoma. However, the details and mechanisms underlying neurogenesis from GCPs are not well understood. Using long-term live-cell imaging of proliferating GCPs transfected with a fluorescent newborn-granule cell marker, we found that GCPs underwent predominantly symmetric divisions, generating two GCPs or two neurons, while asymmetric divisions generating a GCP and a neuron were only occasionally observed, in both dissociated culture and within tissues of isolated cerebellar lobules. We found no significant difference in cell cycle length between proliferative and neurogenic divisions, or any consistent changes in cell cycle length during repeated proliferative division. Unlike neural stem cells in the cerebral cortex and spinal cord, which generate many neurons by repeated asymmetric division, cerebellar GCPs produce neurons predominantly by terminal symmetric division. These results indicate diverse mechanisms of neurogenesis in the mammalian brain. © 2015 Wiley Periodicals, Inc.

  15. Enhanced aerobic nitrifying granulation by static magnetic field.

    Science.gov (United States)

    Wang, Xin-Hua; Diao, Mu-He; Yang, Ying; Shi, Yi-Jing; Gao, Ming-Ming; Wang, Shu-Guang

    2012-04-01

    One of the main challenging issues for aerobic nitrifying granules in treating high strength ammonia wastewater is the long granulation time required for activated sludge to transform into aerobic granules. The present study provides a novel strategy for enhancing aerobic nitrifying granulation by applying an intensity of 48.0mT static magnetic field. The element analysis showed that the applied magnetic field could promote the accumulation of iron compounds in the sludge. And then the aggregation of iron decreased the full granulation time from 41 to 25days by enhancing the setting properties of granules and stimulating the secretion of extracellular polymeric substances (EPS). Long-term, cycle experiments and fluorescence in-situ hybridization (FISH) analysis proved that an intensity of 48.0mT magnetic field could enhance the activities and growth of nitrite-oxidizing bacteria (NOB). These findings suggest that magnetic field is helpful and reliable for accelerating the aerobic nitrifying granulation. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. Prediction of suitable amount of water addition for wet granulation.

    Science.gov (United States)

    Miwa, A; Yajima, T; Itai, S

    2000-02-15

    The purpose of this study was to predict the amounts of water addition suitable for pharmaceutical formulations in wet granulation, using a high-speed mixer or a fluidized bed granulator, before granulation trials. In order to determine the suitable amount of water addition, each excipient was first subjected to kneading with water in a mortar and a refractive near-infrared moisture sensor (IR sensor) measured the amount of water at the powder surface. Further by analysis the plot (output value of the IR sensor vs. amount of added water) for each excipient, the amount of water addition for granulation was determined for it. As a second step, two model formulations were designed and suitable amounts of water for granulation were predicted by summation of the obtained excipient values. The predicted value was compared with the experimental value for high-speed mixer granulation. The predicted and experimental amounts of water addition corresponded for the two model formulations, suggesting that the above method is useful for estimating suitable amounts of addition of water for formulations before granulation trials.

  17. UNCERTAINTY HANDLING IN DISASTER MANAGEMENT USING HIERARCHICAL ROUGH SET GRANULATION

    Directory of Open Access Journals (Sweden)

    H. Sheikhian

    2015-08-01

    Full Text Available Uncertainty is one of the main concerns in geospatial data analysis. It affects different parts of decision making based on such data. In this paper, a new methodology to handle uncertainty for multi-criteria decision making problems is proposed. It integrates hierarchical rough granulation and rule extraction to build an accurate classifier. Rough granulation provides information granules with a detailed quality assessment. The granules are the basis for the rule extraction in granular computing, which applies quality measures on the rules to obtain the best set of classification rules. The proposed methodology is applied to assess seismic physical vulnerability in Tehran. Six effective criteria reflecting building age, height and material, topographic slope and earthquake intensity of the North Tehran fault have been tested. The criteria were discretized and the data set was granulated using a hierarchical rough method, where the best describing granules are determined according to the quality measures. The granules are fed into the granular computing algorithm resulting in classification rules that provide the highest prediction quality. This detailed uncertainty management resulted in 84% accuracy in prediction in a training data set. It was applied next to the whole study area to obtain the seismic vulnerability map of Tehran. A sensitivity analysis proved that earthquake intensity is the most effective criterion in the seismic vulnerability assessment of Tehran.

  18. ATP storage and uptake by isolated pancreatic zymogen granules

    DEFF Research Database (Denmark)

    Haanes, Kristian Agmund; Novak, Ivana

    2010-01-01

    ATP is released from pancreatic acini in response to cholinergic and hormonal stimulation. The same stimuli cause exocytosis of ZG (zymogen granules) and release of digestive enzymes. The aim of the present study was to determine whether ZG stored ATP and to characterize the uptake mechanism...... for ATP transport into the ZG. ZG were isolated and the ATP content was measured using luciferin/luciferase assays and was related to protein in the sample. The estimate of ATP concentration in freshly isolated granules was 40-120 µM. The ATP uptake had an apparent Km value of 4.9±2.1 mM when granules...

  19. Does Thermal Granulation Drive Tephra Jets?

    Science.gov (United States)

    White, J. D.; Zimanowski, B.; Buettner, R.; Sonder, I.; Dellino, P.

    2011-12-01

    Surtseyan tephra jets, also called cypressoid or cock's tail plumes, comprise a characteristic mixture of ash with bombs travelling roughly ballistic paths that tip the individual fingers of the projecting jet. Jets of similar form but smaller scale are generated by littoral magma-water interactions, confirming the general inference that surtseyan tephra jets are a characteristic product of explosive magma-water interaction, and suggesting that magmatic volatiles play a subsidiary role, if any, in their formation. Surtseyan jets have been inferred to result from both intense fuel-coolant interactions, and from simple boiling of water entrained into rising magma, and little new information has become available to test these two positions since they were clearly developed in the 1980s. Recent experiments in which magma is poured into standing water have produced vigorous jetting of hot water as melt solidifies and undergoes extensive thermal granulation. We present high-resolution hi-speed video of these jets, which we see as having the following origin. As thermal granulation takes place, a fracture network advances into the melt/glass body, and water invading the cracks at the rate of propagation is heated nearly instantaneously. Vapor produced at the contact expands and drives outward through cooled cracks, condensing as it moves to the exterior of the magma body where it is emitted as a jet of hot water. In ocean ridge hydrothermal systems a diffuse crack network inducts cold water, which is heated and expelled in focused jets. Focusing of hot outflow in experiments is inferred to result, as suggested for ridge hydrothermal systems, from thermoelastic closure of cracks near the one(s) feeding the jet. From the cooled products of our experimental runs, we know that thermal contraction produces a network of curved cracks with modal spacing of 1-2 mm, which separate domains of unbroken glass. It is during growth of this crack network that cold water enters, is

  20. A review of monitoring methods for pharmaceutical wet granulation.

    Science.gov (United States)

    Hansuld, E M; Briens, L

    2014-09-10

    High-shear wet granulation is commonly used in the pharmaceutical industry to improve powder properties for downstream processes such as tabletting. Granule growth, however, is difficult to predict because the process is sensitive to raw material properties and operating conditions. Development of process analytical technologies is encouraged by regulatory bodies to improve process understanding and monitor quality online. The primary technologies investigated for high-shear wet granulation monitoring include power consumption, near-infrared spectroscopy, Raman spectroscopy, capacitance measurements, microwave measurements, imaging, focused beam reflectance measurements, spatial filter velocimetry, stress and vibration measurements, as well as acoustic emissions. This review summarizes relevant research related to each of these technologies and discusses the challenges associated with each approach as a possible process analytical technology tool for high-shear wet granulation. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. In vitro binding of puroindolines to wheat starch granules

    DEFF Research Database (Denmark)

    Sørensen, Helle Aagaard; Darlington, H.F.; Shewry, P.R.

    2001-01-01

    Puroindoline (pin) preparations made from flours of hard and soft wheats contained a mixture of pin-a, 0.19/0.53 alpha -amylase inhibitor, and purothionins. Starch granule preparations from the same cultivars were treated with proteinase to remove surface proteins and incubated with solutions...... of the pin preparations. Binding of pin-a and purothionins but not the 0.19/0.53 inhibitor was observed with no apparent differences between the behavior of the pin preparations or starch granule preparations from hard or soft types. No binding was observed when several other proteins (bovine serum albumin......, total albumins, a commercial preparation of wheat alpha -amylase inhibitors, and barley beta -amylase) were incubated with the starch granules under the same conditions, indicating that in vitro binding can be used to study specific starch granule and protein interactions....

  2. Heterogeneity of secretory granules of silent pituitary adenomas

    DEFF Research Database (Denmark)

    Holck, S; Wewer, U M; Albrechtsen, R

    1988-01-01

    Silent pituitary adenomas were compared with hormonally active tumors taking into account the size, number, and ultrastructural characteristics of secretory granules (SG). The study group (a total of 79 primary pituitary adenomas) comprised 27 silent, 21 growth hormone (GH)-producing-, 16 prolactin...... (PRL)-producing-, 5 GH-PRL-producing- and 10 adrenocorticotropic hormone (ACTH)-producing adenomas. The SG of silent adenomas were significantly smaller than SG in endocrine active adenomas. All hormonally inactive tumors also contained small (mean, 94 nm) specific cytoplasmic granules, designated...... "silent adenoma granules" (SIG). The fine structural features of the SIG included: a flocculent, granular material occupying an eccentric position in a larger vesicle limited by a double membrane. In the silent adenomas this particular granule was present in up to 90% of the adenoma cells and constituted...

  3. Treatment of hyper-granulated limb wounds in horses

    Directory of Open Access Journals (Sweden)

    O. A. Bader

    2011-01-01

    Full Text Available This study was performed to investigate the different methods of treating hyper granulation tissue on experimentally induced wounds in equine limbs. Wounds were induced by removal of a skin patch and subcutaneous tissue for about 5-7 cm width and 6-8 cm in length from the dorsal and lateral aspect of the fore and hind limbs below the carpal and tarsal joints. The wounds were left open without treatment and the animals were trained 2-2.5 hours every day for about 3-5 weeks until hyper granulation tissue was developed. The schedule for the treatment of hyper granulation was divided into five groups each contained eight wounds of hyper granulation tissue; each main group was divided into two subgroups. The subgroups of first, second, third, fourth and fifth groups were treated by the following schedules: bandage alone; copper sulphate ointment 10%; silver nitrate ointment 2%; red mercury ointment 11%; and laser therapy (at a total dose of 9.72 Joule / cm2 respectively. While the second subgroups were treated by surgical resection of the hyper granulation tissue, followed by the same treatments applied on the first subgroup. The bandage for all experimental groups was changed every 48 hours until healing was occurred. The clinical and histological observation of the first group revealed that the healing take long period comparing with other groups. The mean of wound healing were 65 days in non surgical removal of hyper granulation tissue subgroup, while 57 days in surgical removed of hyper granulation tissue subgroup. The results of the second, third, fourth groups revealed that the caustic material especially red mercury has a role in healing processes through depressing the hyper granulation tissue. The mean of wound healing of the second group was 42.25 days in non surgical removal of hyper granulation tissue subgroup while 37.25 days in surgically removed hyper granulation tissue subgroup. In the third group the mean of wound healing was 45

  4. Carbon-rich wastes as feedstocks for biodegradable polymer (polyhydroxyalkanoate) production using bacteria.

    Science.gov (United States)

    Nikodinovic-Runic, Jasmina; Guzik, Maciej; Kenny, Shane T; Babu, Ramesh; Werker, Alan; O Connor, Kevin E

    2013-01-01

    Research into the production of biodegradable polymers has been driven by vision for the most part from changes in policy, in Europe and America. These policies have their origins in the Brundtland Report of 1987, which provides a platform for a more sustainable society. Biodegradable polymers are part of the emerging portfolio of renewable raw materials seeking to deliver environmental, social, and economic benefits. Polyhydroxyalkanoates (PHAs) are naturally-occurring biodegradable-polyesters accumulated by bacteria usually in response to inorganic nutrient limitation in the presence of excess carbon. Most of the early research into PHA accumulation and technology development for industrial-scale production was undertaken using virgin starting materials. For example, polyhydroxybutyrate and copolymers such as polyhydroxybutyrate-co-valerate are produced today at industrial scale from corn-derived glucose. However, in recent years, research has been undertaken to convert domestic and industrial wastes to PHA. These wastes in today's context are residuals seen by a growing body of stakeholders as platform resources for a biobased society. In the present review, we consider residuals from food, plastic, forest and lignocellulosic, and biodiesel manufacturing (glycerol). Thus, this review seeks to gain perspective of opportunities from literature reporting the production of PHA from carbon-rich residuals as feedstocks. A discussion on approaches and context for PHA production with reference to pure- and mixed-culture technologies is provided. Literature reports advocate results of the promise of waste conversion to PHA. However, the vast majority of studies on waste to PHA is at laboratory scale. The questions of surmounting the technical and political hurdles to industrialization are generally left unanswered. There are a limited number of studies that have progressed into fermentors and a dearth of pilot-scale demonstration. A number of fermentation studies show

  5. Impact of nitrogen feeding regulation on polyhydroxyalkanoates production by mixed microbial cultures.

    Science.gov (United States)

    Silva, Fernando; Campanari, Sabrina; Matteo, Stefania; Valentino, Francesco; Majone, Mauro; Villano, Marianna

    2017-07-25

    A sequencing batch reactor (SBR) is typically used for selecting mixed microbial cultures (MMC) for polyhydroxyalkanoate (PHA) production. Since many waste streams suitable as process feedstock for PHA production are nitrogen-deficient, a nutrient supply in the SBR is typically required to allow for efficient microbial growth. The scope of this study was to devise a nitrogen feeding strategy which allows controlling the nitrogen levels during the feast and famine regime of a lab-scale SBR, thereby selecting for PHA-storing microorganisms. At the beginning of the cycle the reactor was fed with a synthetic mixture of acetic and propionic acids at an overall organic load rate of 8.5gCODL -1 d -1 (i.e. 260CmmolL -1 d -1 ), whereas nitrogen (in the form of ammonium sulphate) was added either simultaneously to the carbon feed (coupled feeding strategy) or after the end of the feast phase (uncoupled feeding strategy). As a main result, PHA production was more than doubled (up to about 1300±64mgCODL -1 ) when carbon and nitrogen were separately fed and the higher PHA production also corresponded to an 82% increase in the polymer HV content (up to 20±1%, wtwt -1 ). Three SBR runs were performed with the uncoupled carbon and nitrogen feeding at different carbon to nitrogen (C/N) ratios (of 14.3, 17.9, and 22.3CmolNmol -1 , respectively) which were varied by progressively reducing the concentration of the nitrogen feeding. In spite of a comparable PHA storage yield at 14.3 and 17.9CmolNmol -1 (0.41±0.05 gCOD PHA gCOD VFA -1 and 0.38±0.05 gCOD PHA gCOD VFA -1 , respectively), the storage response of the selected MMC significantly decreased when the C/N ratio was set at the highest investigated value. Notably, an increase in this parameter also resulted in a change in the HV content in the polymer regardless the composition of the organic acids solution. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Methodological issues in life cycle assessment of mixed-culture polyhydroxyalkanoate production utilising waste as feedstock.

    Science.gov (United States)

    Heimersson, Sara; Morgan-Sagastume, Fernando; Peters, Gregory M; Werker, Alan; Svanström, Magdalena

    2014-06-25

    Assessing the environmental performance of emerging technologies using life cycle assessment (LCA) can be challenging due to a lack of data in relation to technologies, application areas or other life cycle considerations, or a lack of LCA methodology that address the specific concerns. Nevertheless, LCA can be a valuable tool in the environmental optimisation in the technology development phase. One emerging technology is the mixed-culture production of polyhydroxyalkanoates (PHAs). PHA production by pure microbial cultures has been developed and assessed in several LCAs during the previous decade. Recent developments within mixed-culture PHA production call for environmental assessment to guide in technology development. Mixed-culture PHA production can use the organic content in wastewater as a feedstock; the production may then be integrated with wastewater treatment (WWT) processes. This means that mixed-culture PHA is produced as a by-product from services in the WWT. This article explores different methodological challenges for LCA of mixed-culture PHA production using organic material in wastewater as feedstock. LCAs of both pure- and mixed-culture PHA production were reviewed. Challenges, similarities and differences when assessing PHA production by mixed- or pure-cultures were identified and the resulting implications for methodological choices in LCA were evaluated and illustrated, using a case study with mixed- and pure-culture PHA model production systems, based on literature data. Environmental impacts of processes producing multiple products or services need to be allocated between the different products or services. Such situations occur both in feedstock production and when the studied system is providing multiple functions. The selection of allocation method is shown to determine the LCA results. The type of data used, for electricity in the energy system, is shown to be important for the results, which indicates, a strong regional dependency of

  7. Kit systems for granulated decontamination formulations

    Science.gov (United States)

    Tucker, Mark D.

    2010-07-06

    A decontamination formulation and method of making that neutralizes the adverse health effects of both chemical and biological compounds, especially chemical warfare (CW) and biological warfare (BW) agents, and toxic industrial chemicals. The formulation provides solubilizing compounds that serve to effectively render the chemical and biological compounds, particularly CW and BW compounds, susceptible to attack, and at least one reactive compound that serves to attack (and detoxify or kill) the compound. The formulation includes at least one solubilizing agent, a reactive compound, a sorbent additive, and water. A highly adsorbent sorbent additive (e.g., amorphous silica, sorbitol, mannitol, etc.) is used to "dry out" one or more liquid ingredients into a dry, free-flowing powder that has an extended shelf life, and is more convenient to handle and mix in the field. The formulation can be pre-mixed and pre-packaged as a multi-part kit system, where one or more of the parts are packaged in a powdered, granulated form for ease of handling and mixing in the field.

  8. Height variation of the solar granulation

    Science.gov (United States)

    Krieg, J.; Wunnenberg, M.; Kneer, F.; Koschinsky, M.; Ritter, C.

    1999-03-01

    We analyze spectral scans of narrow-band images across the Na D_2 line. They were obtained from disc centre of the Sun with our Fabry-Perot interferometer (FPI) in the Vacuum Tower Telescope at the Observatorio del Teide. The FPI was set to a bandwidth of 200 mAngstroms FWHM and the spectral stepwidth was 100 mAngstroms. Our aim is to study the variation of the granulation pattern with height in the atmosphere. To achieve high spatial resolution the simultaneously taken broad-band images are restored with speckle methods. With the knowledge of these reconstructed images we were also able to restore the narrow-band images. The formation heights are found from temperature response functions RF_T. In the wings of NaD_2, the response functions for different wavelengths exhibit a substantial overlap in atmospheric heights. Therefore we use linear combinations which allow a better height discrimination. Applying the same combinations to the D_2 images we can visualize the height variation of the granular pattern. The granular intensity fluctuations are a matter of the deep photosphere alone. They disappear at heights of about 100 km (above tau_ {5000}=1).

  9. Development of granules from Phyllanthus niruri spray-dried extract

    Directory of Open Access Journals (Sweden)

    Tatiane Pereira de Souza

    2009-12-01

    Full Text Available The aim of this study was to develop granules from Phyllanthus niruri spray-dried extract using dry and wet granulation and to assess techniques to enable the production of granules with improved technological characteristics and yields. Granules were characterized by granulometry, reological parameters, compression and hygroscopic behavior. Independent of the granulation technique, technologically developed granules presented particle diameter, bulk and tapped densities and compressibility indexes suitable for a solid dosage form. The compression behavior showed plastic and fragmentary deformation for granules produced by the dry granulation technique and predominantly plastic deformation for wet granulation. Concerning the humidity sorption, the study showed that granules absorb less humidity than the spray-dried extract. However, granules with Eudragit® E 100 were the least hygroscopic.O objetivo deste estudo foi desenvolver grânulos de extrato Phyllantus niruri seco por aspersão e por granulação úmida e avaliar técnicas que possibilitem a produção de grânulos com características tecnológicas e rendimentos aperfeiçoados. Os grânulos foram caracterizados por granulometria, parâmetros reológicos, compressão e comportamento higroscópico. Independentemente da técnica de granulação, os grânulos tecnologicamente desenvolvidos apresentaram diâmetro de partículas, densidades aparente e compactada e índices de compressibilidade adequados para a formulação sólida. O comportamento de compressão mostrou deformação plástica e elástica para os grânulos produzidos por técnicas de granulação seca e, predominantemente, deformação plástica para a granulação úmida. Com relação à absorção da umidade, o estudo mostrou que os grânulos absorvem menos umidade do que o extrato seco por aspersão. Entretanto, os grânulos com Eudragit E 100 foram os menos higroscópicos.

  10. Sludge granulation during anaerobic treatment of pre-hydrolysed ...

    African Journals Online (AJOL)

    An upflow anaerobic sludge bed (UASB) digester was operated at different hydraulic retention times (HRT) ranging from 26.7 h to 2.2 h, while the organic load rate (OLR) ranged from 0.9 to 7.3 kgCOD/m3·d. Sludge granulation was observed after day 150 of operation, at an HRT of 3.4 h, when small granules of less than 2 ...

  11. Superheated superconducting granules: a detector for particle physics and astrophysics

    International Nuclear Information System (INIS)

    Gonzalez-Mestres, L.; Perret-Gallix, D.

    1987-01-01

    A general introduction to superheated superconducting granules (SSG) detectors is given and some recent results on their basic properties are presented. Granules recently made by industrial producers exhibit good metastability properties and show sensitivity, better than naively expected, to photons and ionizing particles. The behaviour of SSG detectors at very low temperatures is also discussed. We finally sketch a critical review of proposed applications to the cross-disciplinary frontier between particle physics and astrophysics

  12. Effect of granular activated carbon on the aerobic granulation of sludge and its mechanism.

    Science.gov (United States)

    Tao, Jia; Qin, Lian; Liu, Xiaoying; Li, Bolin; Chen, Junnan; You, Juan; Shen, Yitian; Chen, Xiaoguo

    2017-07-01

    The granulation of activated sludge and effect of granular activated carbon (GAC) was investigated under the alternative anaerobic and aerobic conditions. The results showed that GAC accelerated the granulation, but had no obvious effect on the bacterial community structure of granules. The whole granulation process could be categorized into three phases, i.e. lag, granulation and granule maturation phase. During lag period GAC provided nuclei for sludge to attach, and thus enhanced the morphological regularization of sludge. During granulation period the granule size increased significantly due to the growth of bacteria in granules. GAC reduced the compression caused by the inter-particle collisions and thus accelerate the granulation. GAC has no negative effect on the performance of SBR, and thus efficient simultaneous removal of COD, nitrogen and phosphorus were obtained during most of the operating time. Copyright © 2017. Published by Elsevier Ltd.

  13. Aerobic granulation in a sequencing batch airlift reactor.

    Science.gov (United States)

    Beun, J J; van Loosdrecht, M C M; Heijnen, J J

    2002-02-01

    Aerobic granular sludge was cultivated in an intensely mixed sequencing batch airlift reactor (SBAR). A COD loading of 2.5 kg Acetate-COD/(m3 d) was applied. Granules developed in the reactor within one week after inoculation with suspended activated sludge from a conventional wastewater treatment plant. Selection of the dense granules from the biomass mixture occurs because of the differences in settling velocities between granules (fast settling biomass), and filaments and flocs (slow settling biomass). At 'steady state' the granules had an average diameter of 2.5 mm, a biomass density of 60g VSS/I of granules, and a settling rate of > 10 m/h. The biomass consisted of both heterotrophic and nitrifying bacteria. The reactor was operated over a long period during which the granular sludge proved to remain stable. The performance of the intermittently fed SBAR was compared to that of the continuously fed biofilm airlift suspension reactor (BASR). The most importance difference was that the density of the granules in the SBAR was much higher than the density of the biofilms in the BASR. It is discussed that this could be due to the fact that the SBAR is intermittently fed, while the BASR is continuously fed.

  14. Modeling agglomeration processes in fluid-bed granulation

    Energy Technology Data Exchange (ETDEWEB)

    Cryer, S.A.

    1999-10-01

    Many agrochemicals are formulated as water dispersive granules through agglomeration, beginning with a fine powder ({approximately}1 {micro}m) and ending with granules on the order of 500 {micro}m. Powders are charged into a granulation system with a liquid binding agent, and granules are subsequently grown to an appropriate size. Granulation in fluid beds is presented using a mass conserving discretized population balance equation. Coalesce kernels governing the rate and extent of granulation are assumed dependent on the Stokes number, which is indirectly liked to important process variables (air and under flow rate, bed charge, bed geometry) such that the physical processes governing particle coalescence and rebound are correlated to process variables. A new coalescence kernel is proposed based on physical insight, simplicity, and deterministic equivalent modeling to account for uncertainty. This kernel is based on a Stokes number method where uncertainty in the Stokes number is characterized by polynomial chaos expansions. The magnitude of the coalescence kernel is proportional to the probability of the distribution of Stokes number exceeding a critical value. This mechanistic/semiempirical approach to fluid-bed agglomeration fosters an environment for process scaleup by eliminating specific equipment and process variable constraints to focus on the underlying mechanisms for proper scale-up procedures. Model predictions using this new kernel are then compared to experimental pilot-plant observations.

  15. Validation of fluid bed granulation utilizing artificial neural network.

    Science.gov (United States)

    Behzadi, Sharareh Salar; Klocker, Johanna; Hüttlin, Herbert; Wolschann, Peter; Viernstein, Helmut

    2005-03-03

    Three innovative components (an annular gap spray system, a booster bottom and an outlet filter) have been developed by Innojet Technologies to improve fluid bed technology and to reduce the common interference factors (clogging of nozzles and outlet filters, spray loss, spray drying and fluidized bed heterogeneity). In a fluid bed granulator, three conventional components have been replaced with these innovative components. Validation of the modified fluid bed granulator has been conducted using a generalized regression neural network (GRNN). Under different operating conditions (by variation of inlet air temperature, liquid-binder spray rate, atomizing air pressure, air velocity, amount and concentration of binder solution and batch size), sucrose was granulated and the properties of size, size distribution, flow rate, repose angle and bulk and tapped volumes of granules were measured. To confirm the method's validity, the trained network has been used to predict new granulation parameters as well as granule properties. These forecasts were then compared with the corresponding experimental results. Good correlation has been obtained between the predicted and the experimental data. From these findings, we conclude that the GRNN may serve as a reliable method to validate the modified fluid bed apparatus.

  16. Rapid start-up and improvement of granulation in SBR.

    Science.gov (United States)

    Jalali, Sajjad; Shayegan, Jalal; Rezasoltani, Samira

    2015-01-01

    The aim of this study is to accelerate and improve aerobic granulation within a Sequencing Batch Reactor (SBR) by cationic polymer addition. To identify whether the polymer additive is capable of enhancing granule formation, two SBRs (R1 and R2, each 0.15 m in diameter and 2 m in height) are used by feeding synthetic wastewater. The cationic polymer with concentration of 30 to 2 ppm is added to R2, while no cationic polymer is added to R1. Results show that the cationic polymer addition causes faster granule formation and consequently shorter reactor start-up period. The polymer-amended reactor contains higher concentration of biomass with better settling ability (23% reduction in SVI15) and larger and denser granules (112% increase of granular diameter). In addition, the results demonstrate that the cationic polymer improve the sludge granulation process by 31% increase in Extracellular Polymer Substance(EPS) concentration, 7% increase in Specific Oxygen Uptake Rate(SOUR), 18% increase in hydrophobicity, and 17% reduction in effluent Mixed Liquor Suspended Solid(MLSS) concentration. Concludingly, it is found that using the cationic polymer to an aerobic granular system has the potential to enhance the sludge granulation process.

  17. Statistical properties of solar granulation derived from the SOUP instrument on Spacelab 2

    Science.gov (United States)

    Title, A. M.; Tarbell, T. D.; Topka, K. P.; Ferguson, S. H.; Shine, R. A.

    1989-01-01

    Computer algorithms and statistical techniques were used to identify, measure, and quantify the properties of solar granulation derived from movies collected by the Solar Optical Universal Polarimeter on Spacelab 2. The results show that there is neither a typical solar granule nor a typical granule evolution. A granule's evolution is dependent on local magnetic flux density, its position with respect to the active region plage, its position in the mesogranulation pattern, and the evolution of granules in its immediate neighborhood.

  18. Abnormal ion content, hydration and granule expansion of the secretory granules from cystic fibrosis airway glandular cells

    International Nuclear Information System (INIS)

    Baconnais, S.; Delavoie, F.; Zahm, J.M.; Milliot, M.; Terryn, C.; Castillon, N.; Banchet, V.; Michel, J.; Danos, O.; Merten, M.; Chinet, T.; Zierold, K.; Bonnet, N.; Puchelle, E.; Balossier, G.

    2005-01-01

    The absence or decreased expression of cystic fibrosis transmembrane conductance regulator (CFTR) induces increased Na + absorption and hyperabsorption of the airway surface liquid (ASL) resulting in a dehydrated and hyperviscous ASL. Although the implication of abnormal airway submucosal gland function has been suggested, the ion and water content in the Cystic Fibrosis (CF) glandular secretory granules, before exocytosis, is unknown. We analyzed, in non-CF and CF human airway glandular cell lines (MM-39 and KM4, respectively), the ion content in the secretory granules by electron probe X-ray microanalysis and the water content by quantitative dark field imaging on freeze-dried cryosections. We demonstrated that the ion content (Na + , Mg 2+ , P, S and Cl - ) is significantly higher and the water content significantly lower in secretory granules from the CF cell line compared to the non-CF cell line. Using videomicroscopy, we observed that the secretory granule expansion was deficient in CF glandular cells. Transfection of CF cells with CFTR cDNA or inhibition of non-CF cells with CFTR inh -172, respectively restored or decreased the water content and granule expansion, in parallel with changes in ion content. We hypothesize that the decreased water and increased ion content in glandular secretory granules may contribute to the dehydration and increased viscosity of the ASL in CF

  19. Application of an optimized electroporation procedure for replacement of the polyhydroxyalkanoate synthase I gene in Nocardia corallina.

    Science.gov (United States)

    Valentin, H E; Dennis, D

    1996-07-01

    To develop a system for gene replacement in Nocardia corallina, a protocol for electroporation was optimized by systematic alterations of growth conditions, field strength, time constant and the electroporation buffer. Transformation efficiencies of 0.5 x 10(6) - 3 x 10(6) transformants/microgram plasmid DNA were obtained routinely. The gene encoding the polyhydroxyalkanoate (PHA) synthase I of N. corallina was cloned and interrupted by insertion of a kanamycin-resistance gene. The resulting plasmid was introduced into N. corallina by electroporation to inactivate the wild-type gene by homologous recombination. Kanamycin-resistant clones were screened by Southern hybridization for the absence of the wild-type gene and analyzed for PHA accumulation.

  20. Accumulation of a poly(hydroxyalkanoate) copolymer containing primarily 3-hydroxyvalerate from simple carbohydrate substrates by Rhodococcus sp. NCIMB 40126.

    Science.gov (United States)

    Haywood, G W; Anderson, A J; Williams, D R; Dawes, E A; Ewing, D F

    1991-04-01

    A number of taxonomically-related bacteria have been identified which accumulate poly(hydroxyalkanoate) (PHA) copolymers containing primarily 3-hydroxyvalerate (3HV) monomer units from a range of unrelated single carbon sources. One of these, Rhodococcus sp. NCIMB 40126, was further investigated and shown to produce a copolymer containing 75 mol% 3HV and 25 mol% 3-hydroxybutyrate (3HB) from glucose as sole carbon source. Polyesters containing both 3HV and 3HB monomer units, together with 4-hydroxybutyrate (4HB), 5-hydroxyvalerate (5HV) or 3-hydroxyhexanoate (3HHx), were also produced by this organism from certain accumulation substrates. With valeric acid as substrate, almost pure (99 mol% 3HV) poly(3-hydroxyvalerate) was produced. N.m.r. analysis confirmed the composition of these polyesters. The thermal properties and molecular weight of the copolymer produced from glucose were comparable to those of PHB produced by Alcaligenes eutrophus.

  1. Degradation of corn stover by fungal cellulase cocktail for production of polyhydroxyalkanoates by moderate halophile Paracoccus sp. LL1.

    Science.gov (United States)

    Sawant, Shailesh S; Salunke, Bipinchandra K; Kim, Beom Soo

    2015-10-01

    Bioprocessing of lignocellulose as a renewable resource for fuels, chemicals or value added products is a necessity to fulfil demands of petroleum products. This study aims to convert corn stover to polyhydroxyalkanoates (PHA). Corn stover was hydrolyzed to crude sugars by an on-site prepared cellulase cocktail from co-culture of Trichoderma reesei and Aspergillus niger. The potent PHA producer, Paracoccus sp. LL1, was isolated from Lonar Lake, India and could accumulate PHA up to 72.4% of its dry cell weight. PHA production reached 9.71 g/L from corn stover hydrolysate containing 40 g/L sugar mixture. The PHA synthase gene (phaC) sequence of the isolate showed 79% identity with the phaC gene of Paracoccus seriniphilus (E71) strain from the NCBI database. The nature/type of PHA was found to be poly(3-hydroxybutyrate) by Fourier transform infrared spectroscopy. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Analysis of polyhydroxyalkanoates granuales in bacillus Sp. MFD11 and enterobacter Sp. SEL2

    International Nuclear Information System (INIS)

    Naheed, N.; Jamil, N.

    2016-01-01

    Bacillus sp. MFD11 (JF901809) and Enterobacter sp. SEL2 (JF901810) were isolated from agriculture waste contaminated sites. When fed with 2% glucose as a carbon source, these bacteria produced 75.26±0.45% and 76.61±0.28% PHA of their wet weight respectively. The accumulated PHA was extracted by direct addition of sodium dodysyl sulphate in the culture medium, which yielded 52.3±0.56 micro g/l and 136.21±0.45 micro g/l PHA respectively when assayed with Crotonic acid. The PHA detection medium (PDM) provided nutrient limitation condition which favored accumulation of PHA granules. A tremendous increase in cell size was observed when strain MFD11 was grown in PDM. The size of the granules as revealed by TEM micrographs spanned from 0.1 to 1.5 micro m which is quite large as compared to the size reported in the literature 0.2 to 0.5 micro m 18). (PHA polymer was analyzed by FTIR, GC/MS and proton Nuclear magnetic resonance. The intense absorption band in the spectrum at 1724-1740 cm -1 and 1215 cm -1 to 1280 corresponding to C=O and C-O stretching group, respectively, indicated that the both strains were PHA producers. GC/MS analysis indicated that the polymer produced were copolymers of PHB-co-PHV. NMR also suggested that the extracted PHA was not a homopolymer but was the blend of copolymers with 3HV in lower abundance. Differential calorimetric thermal analysis showed melting temperature of 163 and 169 degree C for PHA produced by both strains, respectively. However, the observed melting temperature was found to be lower than the standard PHB (Signa-aldrich). (author)

  3. Correlation between microbial community and granule conductivity in anaerobic bioreactors for brewery wastewater treatment

    DEFF Research Database (Denmark)

    Shrestha, Pravin; Malvankar, Nikhil S.; Werner, Jeffrey

    2014-01-01

    Prior investigation of an upflow anaerobic sludge blanket (UASB) reactor treating brewery wastes suggested that direct interspecies electron transfer (DIET) significantly contributed to interspecies electron transfer to methanogens. To investigate DIET in granules further, the electrical conducti......Prior investigation of an upflow anaerobic sludge blanket (UASB) reactor treating brewery wastes suggested that direct interspecies electron transfer (DIET) significantly contributed to interspecies electron transfer to methanogens. To investigate DIET in granules further, the electrical...... conductivity and bacterial community composition of granules in fourteen samples from four different UASB reactors treating brewery wastes were investigated. All of the UASB granules were electrically conductive whereas control granules from ANAMMOX (ANaerobic AMMonium OXidation) reactors and microbial...... granules from an aerobic bioreactor designed for phosphate removal were not. There was a moderate correlation (r = 0.67) between the abundance of Geobacter species in the UASB granules and granule conductivity, suggesting that Geobacter contributed to granule conductivity. These results, coupled...

  4. The influence of substrate transport limitation on porosity and methanogenic activity of anaerobic sludge granules

    Energy Technology Data Exchange (ETDEWEB)

    Alphenaar, P.A. (Agricultural Univ., Wageningen (Netherlands). Dept. of Environmental Technology); Perez, M.C. (Agricultural Univ., Wageningen (Netherlands). Dept. of Environmental Technology); Lettinga, G. (Agricultural Univ., Wageningen (Netherlands). Dept. of Environmental Technology)

    1993-05-01

    The relationship between porosity, diameter and methanogenic activity of anaerobic granules has been investigated. Experiments with different granular sludges revealed that substrate transport limitations increase with the diameter of the granules. As a consequence, autolysis can occur in the core of the granule, producing hollow granules. The porosity measurements revealed that the hollow centre is not available for substrate transport. Possibly as an effect of bacterial lysis, the porosity decreases in the more interior layers of the granules. This results in a inactive inner part of the large granules, which is not involved in the treatment process; the specific methanogenic activity decreases with granule size. No marked difference in substrate affinity is observed between granules of different sizes, which probably indicates that for large granules only the exterior is biological active. (orig.)

  5. Improvement of the agitation granulation method to prepare granules containing a high content of a very hygroscopic drug.

    Science.gov (United States)

    Hirai, Nobuaki; Ishikawa, Kazuyuki; Takahashi, Koichi

    2006-11-01

    This study describes a new approach to the preparation of a granulate with a high content of a very hygroscopic powder or drug, using the agitation granulation method, and the development of a tablet formulation using these granulates. A Chinese medicine extract, Hatimi-zio-gan, was used as the model of a very hygroscopic drug. Among the several excipients tested, only porous calcium silicate could be used to prepare granules, with a mixing ratio (extract to porous calcium silicate) from 2:1 to 20:1. With other excipients, very large lumps were formed during the granulation process. The best mixing ratio of extract to porous calcium silicate was 6:1. For preparation of the granules, water could be added to the mixed powder within a range of 1- to 4-times the amount of porous calcium silicate. From these results, it was concluded that the ability of porous calcium silicate to hold large amounts of water in its numerous pores may allow for the preparation of granulates with a high content of very hygroscopic drugs. Starch with partial alpha-links, carboxymethyl starch sodium salt and crospovidone were used for selection of the disintegration agent. When crospovidone was used as a disintegration agent, tablets containing about 70% of the Chinese medicine extract disintegrated in less than 7 min, with good dissolution rates. The same process was applied to extracts of Hotyu-ekki-to, Syo-seiryu-to, Boi-ogi-to and Bohu-tusyo-san. The absorption of paeoniflorin, a characteristic monoterpene glucoside contained in Hatimi-zio-gan extract, was evaluated in beagle dogs after oral administration of the Hatimi-zio-gan tablets prepared in this study. The values of C(max) and AUC obtained after administration of the tablets prepared in this study were significantly greater than those obtained for commercial tablets.

  6. Effect of characteristics of fine iron ores on the granulation behavior of concentrate in sintering granulation process

    Science.gov (United States)

    Wu, Shengli; Que, Zhigang; Zhai, Xiaobo; Li, Kailang

    2017-12-01

    Concentrates have advantages of high ferrous grade, less harmful impurities and lower price. However, the small size and poor granulation behavior of concentrates could deteriorate the permeability of the sinter bed and reduce sinter productivity, thus making it difficult to use concentrates effectively. Therefore, in order to strengthen the granulation behavior of concentrates, granulation experiments were carried out and experiment samples made with one kind of concentrates and five kinds of fine iron ores were produced in this paper. Then, the effects of water absorbility and wettability of fine iron ores on granulation behavior of concentrates were investigated. Furthermore, optimized ore blending recipes were proposed to strengthen the granulation behavior of concentrates by sinter pot tests. Results show that the granulation behavior of concentrates was improved for the samples exhibiting high maximum capillary water and small contact angle in fine iron ores. Compared with the scheme of blending ores containing 15 mass% concentrate, the growth index of quasi-particles increased by 20.62% in the case of iron ore BR-2 replacing half of iron ore BR-1, the vertical sintering speed went up from 26.32 to 29.26 mm min-1, the productivity increased from 1.95 to 2.20 t m-2 h-1. The growth index of the quasi-particles increased by 30% when using iron ore AR-2 to replace half of iron ore AR-1. The vertical sintering speed and the productivity of sinter improved to 29.82 mm min-1 and 2.24 t m-2 h-1, respectively. The results help to improve the granulation behavior of concentrates by optimizing the blending ore recipes, based on the characteristics of fine iron ores, and thus use these concentrates more efficiently in the sintering process.

  7. Overcoming Microalgae Harvesting Barrier by Activated Algae Granules.

    Science.gov (United States)

    Tiron, Olga; Bumbac, Costel; Manea, Elena; Stefanescu, Mihai; Nita Lazar, Mihai

    2017-07-05

    The economic factor of the microalgae harvesting step acts as a barrier to scaling up microalgae-based technology designed for wastewater treatment. In view of that, this study presents an alternative microalgae-bacteria system, which is proposed for eliminating the economic obstacle. Instead of the microalgae-bacteria (activated algae) flocs, the study aimed to develop activated algae granules comprising the microalgae Chlorella sp. as a target species. The presence of the filamentous microalgae (Phormidium sp.) was necessary for the occurrence of the granulation processes. A progressive decrease in frequency of the free Chlorella sp. cells was achieved once with the development of the activated algae granules as a result of the target microalgae being captured in the dense and tangled network of filaments. The mature activated algae granules ranged between 600 and 2,000 µm, and were characterized by a compact structure and significant settling ability (21.6 ± 0.9 m/h). In relation to the main aim of this study, a microalgae recovery efficiency of higher than 99% was achieved only by fast sedimentation of the granules; this performance highlighted the viability of the granular activated algae system for sustaining a microalgae harvesting procedure with neither cost nor energy inputs.

  8. Physicochemical and tablet properties of Cyperus alulatus rhizomes starch granules.

    Science.gov (United States)

    Paramakrishnan, N; Jha, S; Kumar, K Jayaram

    2015-05-01

    The starch extracted from rhizomes of Cyperus alulatus (CA) was characterized for its physicochemical, morphological and tableting properties. Rhizomes of CA yield a significant quantity of starch granules (CASG) i.e., 11.93%. CASG was characterized in terms of moisture, ash and amylose contents, solubility and swelling power, paste clarity and water retention capacity. The swelling power was found to be significantly improved with the increase in temperature. Scanning electron micrographs revealed that the granule's surface was smooth, the granules were spherical, mostly round, disc like, and the size range was 6.65-12.13 μm. Finger print region in FTIR spectra confirmed its carbohydrate nature. The evaluated micromeritic properties of extracted granule's bulk density, tapped density, Carr's index, Hausner ratio, true density and porosity render unique practicability of CASG being used as an adjuvant in pharmaceutical solid dosage forms. Tablets prepared by using CASG showed higher mechanical strength and more disintegration time, which depicted the characteristic binding nature of the starch granules. As CASG is imparting better binding properties in less concentration and also it can be used in combination with the established starches to get the synergistic effect; this starch can be used commercially in the tablet preparation. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. An investigation into the effect of formulation variables and process parameters on characteristics of granules obtained by in situ fluidized hot melt granulation.

    Science.gov (United States)

    Mašić, Ivana; Ilić, Ilija; Dreu, Rok; Ibrić, Svetlana; Parojčić, Jelena; Durić, Zorica

    2012-02-28

    The aim of this study was to investigate the influence of binder content, binder particle size, granulation time and inlet air flow rate on granule size and size distribution, granule shape and flowability, as well as on drug release rate. Hydrophilic (polyethyleneglycol 2000) and hydrophobic meltable binder (glyceryl palmitostearate) were used for in situ fluidized hot melt granulation. Granule size was mainly influenced by binder particle size. Binder content was shown to be important for narrow size distribution and good flow properties. The results obtained indicate that conventional fluid bed granulator may be suitable for production of highly spherical agglomerates, particularly when immersion and layering is dominant agglomeration mechanism. Granule shape was affected by interplay of binder content, binder particle size and granulation time. Solid state analysis confirmed unaltered physical state of the granulate components and the absence of interactions between the active and excipients. Besides the nature and amount of binder, the mechanism of agglomerate formation seems to have an impact on drug dissolution rate. The results of the present study indicate that fluidized hot melt granulation is a promising powder agglomeration technique for spherical granules production. Copyright © 2011 Elsevier B.V. All rights reserved.

  10. Possibility of monitoring granulation by analyzing the amount of hydroxypropylcellulose, a binder on the surface of granules, using ToF-SIMS.

    Science.gov (United States)

    Furudate, Takeaki; Kurasako, Yuta; Takata, Eriko; Morishita, Taku; Miwa, Akio; Suzuki, Rei; Terada, Katsuhide

    2015-11-30

    The purpose of this study was to clarify the mechanism responsible for high-shear wet granulation using time-of-flight secondary ion mass spectrometry (ToF-SIMS), which can be used for surface chemical mapping. A total of 15 kinds of granules, including hydroxypropylcellulose (HPC) as a binder, were obtained in a model formulation using different granulation conditions, such as the amount of sprayed water and the granulation time. Surface chemical mapping of these granules was then performed using a ToF-SIMS analysis, which distinguishes each component by detecting the specific mass-to-charge ratio (m/z). As a result, we found that HPC got to appear on the surface of granule with proceeding wet granulation. By considering this result, we concluded that the distributions of HPC might be closely related to the progress of granule consolidation and growth in wet granulation. Therefore, the progress of granulation can likely be understood by measuring the content of HPC on the granule surface. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Pharmacokinetics of rabeprazole granules versus tablets, and the effect of food on the pharmacokinetics of rabeprazole granules in healthy adults-cross-study comparison.

    Science.gov (United States)

    Thyssen, An; Solanki, Bhavna; Gonzalez, Martha; Leitz, Gerhard; Treem, William; Mannaert, Erik

    2014-09-01

    The primary objective was to compare the pharmacokinetics (PK) of rabeprazole granules versus rabeprazole tablets, and assess the effect of food on the PK of rabeprazole granules. Data from three phase 1, open-label, single-dose, randomized, crossover studies in healthy adult participants are presented separately and as a cross-study comparison; study 1: PK of phase 1 rabeprazole granules versus rabeprazole tablets under fasting conditions; study 2: PK of phase 3 rabeprazole granules versus phase 1 rabeprazole granules; study 3: bioequivalence of to-be-marketed rabeprazole granules (sprinkle capsules) versus phase 3 rabeprazole granules; and assessment of the food effect for the to-be-marketed rabeprazole granules. Overall, 123 of 130 participants enrolled completed the studies. The overall plasma exposure as measured by area under the plasma concentration-time curve (AUC) was comparable between rabeprazole granules and tablets; mean peak plasma concentration (Cmax ) was lower for the granules compared with tablets. The plasma elimination half-life was short and independent of formulation. Food intake prior to administration of the to-be-marketed granules delayed the absorption and reduced the estimated parameters for bioavailability by 55% (Cmax ) and 28% (AUCinf ). Rabeprazole was well-tolerated. © 2014, The American College of Clinical Pharmacology.

  12. The granule porosity controls the loss of compactibility for both dry- and wet-processed cellulose granules but at different rate.

    Science.gov (United States)

    Nordström, Josefina; Alderborn, Göran

    2015-06-01

    The aim of this study was to investigate the role of porosity on the compression behavior and tablet tensile strength for granules produced by a dry granulation procedure. Microcrystalline cellulose was used as a typical pharmaceutical excipient and a comparison was made with the effect of granule porosity on the compression behavior and tablet tensile strength of wet-processed granules of the same composition. Both the wet and dry granulation process caused a loss in compactibility of the material that was controlled by the granule porosity up to a critical point of porosity and friability. Above this threshold value of porosity, the granules nearly collapsed completely into primary particles during compression. In these cases, the micro-structure and tensile strength of the formed tablets resembled that of tablets formed from the original ungranulated powder. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

  13. Block-based approach to modelling of granulated fertilizers' quality

    DEFF Research Database (Denmark)

    Kohonen, J.; Reinikainen, S. P.; Høskuldsson, Agnar

    2009-01-01

    be defined through testing the flow rate with, e.g., seed drill. Besides the chemical composition, flowability can be considered as one of the most important characteristics. There are numerous factors affecting the flowability of a granulated fertilizer, several of them related to the particle size...... distribution. Particle size distribution of the granulated product has to be within the customer specification, but is also a highly significant factor to the quality, especially in the presence of moisture. This can affect numerous phenomena, inter alia, agglomeration and aggregation of granules and Ostwald...... size distribution. The goals are to find a reliable model for flowability using this data and to find the most important variables and to identify the effect of blocks to the quality....

  14. Summary of Granulation Matrix Testing for the Plutonium Immobilization Program

    Energy Technology Data Exchange (ETDEWEB)

    Herman, C.C.

    2001-10-19

    In FY00, a matrix for process development testing was created to identify those items related to the ceramic process that had not been fully developed or tested and to help identify variables that needed to be tested. This matrix, NMTP/IP-99-003, was jointly created between LLNL and SRTC and was issued to all affected individuals. The matrix was also used to gauge the progress of the development activities. As part of this matrix, several series of tests were identified for the granulation process. This summary provides the data and results from the granulation testing. The results of the granulation matrix testing were used to identify the baseline process for testing in the PuCTF with cold surrogates in B241 at LLNL.

  15. High-resolution observations of the solar granulation

    Science.gov (United States)

    Topka, K. P.; Title, A. M.

    1991-01-01

    Digitally-enhanced high-resolution images from space and ground observatories have yielded data on the solar granulation which show it to be a more complex combination of phenomena than previously suspected. These new data have been used to detect large-scale horizontal flows over the solar surface through direct measurements of granule proper motions. The results thus obtained may have important implications for the heating of the solar chromosphere and corona. The observed intensity pattern on the surface of the sun is noted to be due not only to granulation, but the superposition of different types of waves as well. All such phenomena are modified in the presence of magnetic fields, becoming smaller and of reduced contrast.

  16. Mechanistic modelling of the drying behaviour of single pharmaceutical granules

    DEFF Research Database (Denmark)

    Thérèse F.C. Mortier, Séverine; Beer, Thomas De; Gernaey, Krist

    2012-01-01

    The trend to move towards continuous production processes in pharmaceutical applications enhances the necessity to develop mechanistic models to understand and control these processes. This work focuses on the drying behaviour of a single wet granule before tabletting, using a six......-segmented fluidised bed drying system, which is part of a fully continuous from-powder-to-tablet manufacturing line. The drying model is based on a model described by Mezhericher et al. [1] and consists of two submodels. In the first drying phase (submodel 1), the surface water evaporates, while in the second drying...... phase (submodel 2), the water inside the granule evaporates. The second submodel contains an empirical power coefficient, b. A sensitivity analysis was performed to study the influence of parameters on the moisture content of single pharmaceutical granules, which clearly points towards the importance...

  17. Studies on preparation of aceclofenac pellets by centrifugal granulator

    Directory of Open Access Journals (Sweden)

    Zibin GAO

    Full Text Available To prepare aceclofenac pellets by centrifugal granulation. Using 90~100 g of starch pellets as the core pellets,100 g of aceclofenac mixed with 50 g of microcrystalline cellulose(MCC and 4 g talc, methyl cellulose (HPMC as binder,the aceclofenac pellets were prepared by centrifugal granulation .And evaluate the quality of the pellets. The aceclofenac pellets had high yield and less losses,the pellets had a partical size of 0.70~0.88 mm(18~24 mesh)and had uniform particle size .the moisture ,drug content and dissolution meet the requirement . Aceclofenac pellets were prepared by the process of centrifugal granulation .The preparation prescription and process parameters were optimized by single factor method .and the pellets meet the standard requirements.

  18. Morphology of dentate granule cells in the human epileptogenic hippocampus.

    Science.gov (United States)

    von Campe, G; Spencer, D D; de Lanerolle, N C

    1997-01-01

    Hippocampal dentate granule cells in temporal lobe epilepsy (TLE) patients with mesial sclerosis (MTLE) are reported to be hyperexcitable compared to those in patients with a mass lesion outside the hippocampus (MaTLE) (Williamson, Clin Neurosci 1994;2: 47-52). To determine if such hyperexcitability is associated with an altered morphology of these neurons, Lucifer Yellow-filled granule cells from MTLE patients were compared with those from MaTLE. The morphology of granule cells in both subject groups resembles closely that of human granule cells described previously by Golgi studies. About 40% of human granule cells have basal dendrites. Additionally their apical dendrites are much more limited in their spread in the longitudinal axis of the hippocampus contributing perhaps to a much more narrow lamellar organization than in rats. Analysis of variance computed on 21 morphometric parameters reveals a significant increase in the length of the portion of the dendrite in the inner molecular layer (IML), and a decrease in length in the outer third of the molecular layer in MTLE, compared to MaTLE. Factor analysis performed on the morphometric features of each group of neurons reveals that in the MaTLE neurons the most distinctive feature is the total dendritic length and the overall distribution of spines on them, whereas in MTLE a lengthening and elaboration of the dendrites in the IML is most distinctive. Previous observations of increased synaptic terminals containing neuropeptides, and neurotransmitter receptors in the IML taken in conjunction with an elaboration of granule cell dendrites in this region, suggest considerable synaptic reorganization within the IML of the MTLE hippocampus which may contribute to its epileptogenicity.

  19. UVC-induced stress granules in mammalian cells.

    Directory of Open Access Journals (Sweden)

    Mohamed Taha Moutaoufik

    Full Text Available Stress granules (SGs are well characterized cytoplasmic RNA bodies that form under various stress conditions. We have observed that exposure of mammalian cells in culture to low doses of UVC induces the formation of discrete cytoplasmic RNA granules that were detected by immunofluorescence staining using antibodies to RNA-binding proteins. UVC-induced cytoplasmic granules are not Processing Bodies (P-bodies and are bone fide SGs as they contain TIA-1, TIA-1/R, Caprin1, FMRP, G3BP1, PABP1, well known markers, and mRNA. Concomitant with the accumulation of the granules in the cytoplasm, cells enter a quiescent state, as they are arrested in G1 phase of the cell cycle in order to repair DNA damages induced by UVC irradiation. This blockage persists as long as the granules are present. A tight correlation between their decay and re-entry into S-phase was observed. However the kinetics of their formation, their low number per cell, their absence of fusion into larger granules, their persistence over 48 hours and their slow decay, all differ from classical SGs induced by arsenite or heat treatment. The induction of these SGs does not correlate with major translation inhibition nor with phosphorylation of the α subunit of eukaryotic translation initiation factor 2 (eIF2α. We propose that a restricted subset of mRNAs coding for proteins implicated in cell cycling are removed from the translational apparatus and are sequestered in a repressed form in SGs.

  20. An evaluation of fluid bed drying of aqueous granulations.

    Science.gov (United States)

    Hlinak, A J; Saleki-Gerhardt, A

    2000-01-01

    The purpose of the work described was twofold: (a) to apply heat and mass balance approaches to evaluate the fluid bed drying cycle of an aqueous granulation, and (b) to determine the effect of the temperature and relative humidity of the drying air on the ability to meet a predetermined moisture content specification. Water content determinations were performed using Karl Fischer titration, and Computrac and Mark 1 moisture analyzers. The water vapor sorption isotherms were measured using a gravimetric moisture sorption apparatus with vacuum-drying capability. Temperature, relative humidity, and air flow were measured during the drying cycle of a production-scale fluid bed dryer. Heat and mass balance equations were used to calculate the evaporation rates. Evaporation rates calculated from heat and mass balance equations agreed well with the experimental data, whereas equilibrium moisture content values provided useful information for determination of the upper limit for inlet air humidity. Increasing the air flow rate and inlet temperature reduced the drying time through the effect on the primary driving force. As expected, additional drying of granules during the equilibration period did not show a significant impact on reducing the final moisture content of granules. Reducing the drying temperature resulted in measurement of higher equilibrium moisture content for the granules, which was in good agreement with the water vapor sorption data. Heat and mass balance equations can be used to successfully model the fluid bed drying cycle of aqueous granulations. The water vapor sorption characteristics of granules dictate the final moisture content at a given temperature and relative humidity.

  1. Giant arachnoid granulation: differential diagnosis of acute headache

    International Nuclear Information System (INIS)

    Peters, S.A.; Heyer, C.M.; Frombach, E.

    2007-01-01

    Full text: We present a case of intense, rapidly evolving headache clinically mimicking meningitis, subarachnoid haemorrhage or venous sinus thrombosis. Clinical examination, standard blood work and central nervous system studies were non-contributory and effectively ruled out these diagnoses. Cranial multidetector CT studies before and after application of intravenous contrast medium performed prior to lumbar tap disclosed a non-enhancing ovoid mass filling the superior sagittal sinus. This lesion posed a differential to venous sinus thrombosis, but ultimately fulfilled the criteria of a giant arachnoid granulation. The imaging characteristics and differential diagnosis of giant arachnoid granulations are discussed

  2. Process analytical tools for monitoring, understanding, and control of pharmaceutical fluidized bed granulation: A review.

    Science.gov (United States)

    Burggraeve, Anneleen; Monteyne, Tinne; Vervaet, Chris; Remon, Jean Paul; De Beer, Thomas

    2013-01-01

    Fluidized bed granulation is a widely applied wet granulation technique in the pharmaceutical industry to produce solid dosage forms. The process involves the spraying of a binder liquid onto fluidizing powder particles. As a result, the (wetted) particles collide with each other and form larger permanent aggregates (granules). After spraying the required amount of granulation liquid, the wet granules are rapidly dried in the fluid bed granulator. Since the FDA launched its Process Analytical Technology initiative (and even before), a wide range of analytical process sensors has been used for real-time monitoring and control of fluid bed granulation processes. By applying various data analysis techniques to the multitude of data collected from the process analyzers implemented in fluid bed granulators, a deeper understanding of the process has been achieved. This review gives an overview of the process analytical technologies used during fluid bed granulation to monitor and control the process. The fundamentals of the mechanisms contributing to wet granule growth and the characteristics of fluid bed granulation processing are briefly discussed. This is followed by a detailed overview of the in-line applied process analyzers, contributing to improved fluid bed granulation understanding, modeling, control, and endpoint detection. Analysis and modeling tools enabling the extraction of the relevant information from the complex data collected during granulation and the control of the process are highlighted. Copyright © 2012 Elsevier B.V. All rights reserved.

  3. Phenotypic properties and microbial diversity of methanogenic granules from a full-scale UASB reactor treating brewery wastewater

    NARCIS (Netherlands)

    Diaz, E.E.; Stams, A.J.M.; Amils, R.; Sanz, J.L.

    2006-01-01

    Methanogenic granules from an anaerobic bioreactor that treated wastewater of a beer brewery consisted of different morphological types of granules. In this study, the microbial compositions of the different granules were analyzed by molecular microbiological techniques: cloning, denaturing gradient

  4. Inline real-time near-infrared granule moisture measurements of a continuous granulation-drying-milling process.

    Science.gov (United States)

    Chablani, Lipika; Taylor, Michael K; Mehrotra, Amit; Rameas, Patrick; Stagner, William C

    2011-12-01

    The purpose of this research was to use inline real-time near-infrared (NIR) to measure the moisture content of granules manufactured using a commercial production scale continuous twin-screw granulator fluid-bed dryer milling process. A central composite response surface statistical design was used to study the effect of inlet air temperature and dew point on granule moisture content. The NIR moisture content was compared to Karl Fischer (KF) and loss on drying (LOD) moisture determinations. Using multivariate analysis, the data showed a statistically significant correlation between the conventional methods and NIR. The R(2) values for predicted moisture content by NIR versus KF and predicted moisture values by NIR versus LOD were 0.94 (p moisture content as measured by predicted NIR (adjusted R(2) = 0.84, p moisture measurements.

  5. Correlation between microbial community and granule conductivity in anaerobic bioreactors for brewery wastewater treatment

    DEFF Research Database (Denmark)

    Shrestha, Pravin; Malvankar, Nikhil S.; Werner, Jeffrey

    2014-01-01

    conductivity and bacterial community composition of granules in fourteen samples from four different UASB reactors treating brewery wastes were investigated. All of the UASB granules were electrically conductive whereas control granules from ANAMMOX (ANaerobic AMMonium OXidation) reactors and microbial......Prior investigation of an upflow anaerobic sludge blanket (UASB) reactor treating brewery wastes suggested that direct interspecies electron transfer (DIET) significantly contributed to interspecies electron transfer to methanogens. To investigate DIET in granules further, the electrical...... granules from an aerobic bioreactor designed for phosphate removal were not. There was a moderate correlation (r = 0.67) between the abundance of Geobacter species in the UASB granules and granule conductivity, suggesting that Geobacter contributed to granule conductivity. These results, coupled...

  6. Effect of matrix granulation and wax coating on the dissolution rates ...

    African Journals Online (AJOL)

    disintegrating) granules consisting of paracetamol (drug) and acrylatemethacrylate copolymer, a matrix forming material. The effect of coating the matrix granules with wax on the drug release profiles was also investigated. The objective was to ...

  7. Formulation of a poorly water-soluble drug in sustained-release hollow granules with a high viscosity water-soluble polymer using a fluidized bed rotor granulator.

    Science.gov (United States)

    Asada, Takumi; Yoshihara, Naoki; Ochiai, Yasushi; Kimura, Shin-Ichiro; Iwao, Yasunori; Itai, Shigeru

    2018-04-25

    Water-soluble polymers with high viscosity are frequently used in the design of sustained-release formulations of poorly water-soluble drugs to enable complete release of the drug in the gastrointestinal tract. Tablets containing matrix granules with a water-soluble polymer are preferred because tablets are easier to handle and the multiple drug-release units of the matrix granules decreases the influences of the physiological environment on the drug. However, matrix granules with a particle size of over 800 μm sometimes cause a content uniformity problem in the tableting process because of the large particle size. An effective method of manufacturing controlled-release matrix granules with a smaller particle size is desired. The aim of this study was to develop tablets containing matrix granules with a smaller size and good controlled-release properties, using phenytoin as a model poorly water-soluble drug. We adapted the recently developed hollow spherical granule granulation technology, using water-soluble polymers with different viscosities. The prepared granules had an average particle size of 300 μm and sharp particle size distribution (relative width: 0.52-0.64). The values for the particle strength of the granules were 1.86-1.97 N/mm 2 , and the dissolution profiles of the granules were not affected by the tableting process. The dissolution profiles and the blood concentration levels of drug released from the granules depended on the viscosity of the polymer contained in the granules. We succeeded in developing the desired controlled-release granules, and this study should be valuable in the development of sustained-release formulations of poorly water-soluble drugs. Copyright © 2018 Elsevier B.V. All rights reserved.

  8. Determination of size distribution of barley starch granules using low angle laser light scattering

    International Nuclear Information System (INIS)

    Psota, V.; Bohacenko, I.; Pytela, J.; Vydrova, H.; Chmelik, J.

    2000-01-01

    LALLS method (Low Angle Laser Light Scattering) was used to determine the size distribution of starch granules in caryopses of two varieties of malting barley (Hordeum vulgare). Two size fractions of granules were proved similarly to results obtained by other methods. The variety Kompakt contained significantly more large starch granules than the variety Novum. The LALLS method could be used as an accurate, reproducible and quick method for determination of starch granule size distribution

  9. The development of a growth regime map for a novel reverse-phase wet granulation process.

    Science.gov (United States)

    Wade, Jonathan B; Martin, Gary P; Long, David F

    2016-10-15

    The feasibility of a novel reverse-phase wet granulation process has been established and potential advantages identified. Granule growth in the reverse-phase process proceeds via a steady state growth mechanism controlled by capillary forces, whereas granule growth in the conventional process proceeds via an induction growth regime controlled by viscous forces. The resultant reverse-phase granules generally have greater mass mean diameter and lower intragranular porosity when compared to conventional granules prepared under the same liquid saturation and impeller speed conditions indicating the two processes may be operating under different growth regimes. Given the observed differences in growth mechanism and consolidation behaviour of the reverse-phase and conventional granules the applicability of the current conventional granulation regime map is unclear. The aim of the present study was therefore to construct and evaluate a growth regime map, which depicts the regime as a function of liquid saturation and Stokes deformation number, for the reverse-phase granulation process. Stokes deformation number was shown to be a good predictor of both granule mass mean diameter and intragranular porosity over a wide range of process conditions. The data presented support the hypothesis that reverse-phase granules have a greater amount of surface liquid present which can dissipate collision energy and resist granule rebound resulting in the greater granule growth observed. As a result the reverse-phase granulation process results in a greater degree of granule consolidation than that produced using the conventional granulation process. Stokes deformation number was capable of differentiating these differences in the granulation process. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Iron-based granules in body of bumblebees

    Czech Academy of Sciences Publication Activity Database

    Jandacka, P.; Kasparova, B.; Jirásková, Yvonna; Dedkova, K.; Mamulová-Kutláková, K.; Kukutschová, J.

    2015-01-01

    Roč. 28, č. 1 (2015), s. 89-99 ISSN 0966-0844 R&D Projects: GA ČR(CZ) GAP108/11/1350 Institutional support: RVO:68081723 Keywords : Magnetoreception * Bumblebee * Biomineralisation * Iron granules Subject RIV: BO - Biophysics Impact factor: 2.134, year: 2015

  11. Measurement of the moisture content of the granulated sugar by ...

    African Journals Online (AJOL)

    AJB SERVER

    2007-01-18

    Jan 18, 2007 ... The moisture content of granulated sugar is a critical parameter for its transformation into cubes. To the best of our ... resolve this, a new method using infrared transphotometry technique based on the attenuation of an infrared ... contribution of other interactions to the attenuation of the incident wave, i.e. ...

  12. Population balance modelling of fluidized bed melt granulation: an overview

    NARCIS (Netherlands)

    Tan, H.S.; Goldschmidt, M.J.V.; Boerefijn, R.; Hounslow, M.J.; Salman, A.; Kuipers, J.A.M.

    2005-01-01

    This paper presents an overview of the work undertaken by our group to identify and quantify the rates processes active in fluidized bed melt granulation (FBMG). The process involves the identification and development of physically representative models to mechanistically describe FBMG using both

  13. Heterogeneity of secretory granules of silent pituitary adenomas

    DEFF Research Database (Denmark)

    Holck, S; Wewer, U M; Albrechtsen, R

    1988-01-01

    Silent pituitary adenomas were compared with hormonally active tumors taking into account the size, number, and ultrastructural characteristics of secretory granules (SG). The study group (a total of 79 primary pituitary adenomas) comprised 27 silent, 21 growth hormone (GH)-producing-, 16 prolactin...

  14. Thermal effects on granules and direct determination of swelling ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-08-04

    Aug 4, 2009 ... DEA. UAA. Abidjan. Côte d'Ivoire, pp. 25-28. Larrigue S, Alvarez G, Cuvelier G, Flick D (2008). Swelling kinetics of waxy maize and starches at high temperatures and heating rates. Carbohydr. Polym. 73: 148-155. Leach HW, MC Cowen LD, Schoch JJ (1959). Structure of the starch granule swelling and ...

  15. F-Granulation Generalized Rough Entropy and Image Analysis

    Science.gov (United States)

    Pal, Sankar K.

    2012-12-01

    Role of f-granulation in handling uncertainty in machine intelligence and its significance as a facet of natural computation are discussed. Its modeling through judicious integration of rough and fuzzy sets is explained. Several tasks like case generation, clustering, classification and segmentation are described in rough-fuzzy framework demonstrating the role of f-granulation and the resulting merits. A definition of generalized rough sets is given considering both the set and granules as crisp and/or fuzzy. Based on that new entropy measures are defined using exponential and logarithmic gain functions. The superiority of rough-fuzzy integration, in terms of performance and computation time, is illustrated for the tasks of case mining in large data sets, segmenting brain MR images, and classifying remotely sensed images as examples. Neighbourhood rough sets are capable of better dimensionality reduction. The effect of fuzzy-granules and generalizations in rough sets is demonstrated for image segmentation. The article includes some of the results published elsewhere.

  16. Electron microscopic analysis of the specific granule content of ...

    African Journals Online (AJOL)

    Knowledge about the stimulus for the release of atrial natriuretic peptide (ANP) from human atria is incomplete. Atrial stretch is known to be a stimulus and atrial tachyarrhythmias are thought to be another. The effects of atrial size (by twodimensional echocardiography) and atrial fibrillation on the atrial specific granule ...

  17. Discrete element modelling of fluidised bed spray granulation

    NARCIS (Netherlands)

    Goldschmidt, M.J.V.; Weijers, G.G.C.; Boerefijn, R.; Kuipers, J.A.M.

    2003-01-01

    A novel discrete element spray granulation model capturing the key features of fluidised bed hydrodynamics, liquid¿solid contacting and agglomeration is presented. The model computes the motion of every individual particle and droplet in the system, considering the gas phase as a continuum.

  18. Investigation of polymorphic transitions of piracetam induced during wet granulation.

    Science.gov (United States)

    Potter, Catherine B; Kollamaram, Gayathri; Zeglinski, Jacek; Whitaker, Darren A; Croker, Denise M; Walker, Gavin M

    2017-10-01

    Piracetam was investigated as a model API which is known to exhibit a number of different polymorphic forms. It is freely soluble in water so the possibility exists for polymorphic transformations to occur during wet granulation. Analysis of the polymorphic form present during lab-scale wet granulation, using water as a granulation liquid, was studied with powder X-ray diffraction and Raman spectroscopy as off-line and inline analysis tools respectively. Different excipients with a range of hydrophilicities, aqueous solubilities and molecular weights were investigated to examine their influence on these solution-mediated polymorphic transitions and experimental results were rationalised using molecular modelling. Our results indicated that as an increasing amount of water was added to the as-received piracetam FIII, a greater amount of the API dissolved which recrystallised upon drying to the metastable FII(6.403) via a monohydrate intermediary. Molecular level analysis revealed that the observed preferential transformation of monohydrate to FII is linked with a greater structural similarity between the monohydrate and FII polymorph in comparison to FIII. The application of Raman spectroscopy as a process analytical technology (PAT) tool to monitor the granulation process for the production of the monohydrate intermediate as a precursor to the undesirable metastable form was demonstrated. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Extradural granulation complicated by chronic suppurative otitis media with cholesteatoma.

    Science.gov (United States)

    Jang, Chul Ho; Choi, Yong Ho; Jeon, Eun Sun; Yang, Hyung Chae; Cho, Yong Beom

    2014-01-01

    Extrdural granulation or abscess is a possible complication of chronic suppurative otitis media (CSOM) with cholesteatoma. However, due to development of newer antibiotics and advances in bacteriology and imaging techniques, the incidence of extradural granulation or abscess has significantly decreased. The present study analyzed the clinical presentation, imaging findings, and surgical treatment of eight patients with CSOM with cholesteatoma extending to the cranial fossa. From 2000 to 2012, 1,010 patients were surgically treated for CSOM with cholesteatoma. Patients with extension to the cranial fossa were studied. Clinical presentation, imaging studies, operative findings, surgical treatment, and postoperative results were evaluated. Twenty cases (1.9%) in a series of 1,010 patients with CSOM with cholesteatoma had bony destruction of the cranial fossa in the temporal bone computed tomography (cr). Of the 20 cases, eight (0.79%) were identified as extradural granulation by magnetic resonance imaging. One patient exhibited nodular enhancement, but it disappeared on preoperative antibiotic treatment. Surgical access for removal of cholesteatoma with extradural granulation was accomplished through canal wall-down tympanomastoidectomy. CSOM with cholesteatoma can extend to either the middle or posterior cranial fossa. While CT is sufficient to reveal bony destruction of the cranial fossa, magnetic resonance imaging is required to differentiate and define intracranial extension of CSOM with cholesteatoma. Copyright © 2014 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  20. Measurement of the moisture content of the granulated sugar by ...

    African Journals Online (AJOL)

    The moisture content of granulated sugar is a critical parameter for its transformation into cubes. To the best of our knowledge there is no easy-to-use method for the determination of this parameter. To resolve this, a new method using infrared transphotometry technique based on the attenuation of an infrared radiation ...

  1. IL-1 Receptor Antagonist Inhibits Early Granulation Formation.

    Science.gov (United States)

    Nicolli, Elizabeth A; Ghosh, Ankona; Haft, Sunny; Frank, Renee; Saunders, Cecil James; Cohen, Noam; Mirza, Natasha

    2016-04-01

    Using a functional model of airway granulation tissue in laryngotracheal stenosis, we investigated changes in histopathology and inflammatory markers within granulation tissue in response to an interleukin-1 receptor antagonist (IL-1Ra). This study allows us to further delineate the immune response to wound healing and potentially identify treatment markers. Laryngotracheal complexes (LTCs) of donor mice underwent direct airway injury. The LTCs were transplanted into subcutaneous tissue of recipient mice in 2 groups: IL-1Ra treated and untreated. The IL-1Ra-treated arm received daily intraperitoneal injections of IL-1Ra for 3 weeks. The LTCs were then harvested. Granulation formation was measured. The mRNA expression of transforming growth factor (TGF) beta and IL-1 was quantified using real-time reverse transcript polymerase chain reaction. There were statistically significant differences in lamina propria thickness. There were no statistically significant changes in mRNA expression of TGF-β and IL-1β between the treated and untreated specimens. Using a previously described murine model, we delineate inflammatory markers that can be targeted for potential therapy. While the levels of inflammatory markers do not change significantly, the lamina propria thickness shows that the effects of IL-1 have been inhibited. The early use of the IL-1Ra will inhibit the efficacy of IL-1 in the inflammatory cascade and can prevent early granulation formation. © The Author(s) 2015.

  2. Automation system for production of UO2 granules

    International Nuclear Information System (INIS)

    Swaminathan, N.; Setty, C.R.P.; Banerjee, P.K.; Husnain, G.; Rao, K.C.M.; Satyanarayana, A.

    1990-01-01

    Precompaction of UO 2 powder into slugs and granulation of the slugs were used to be carried out in two different work centres involving manual loading/handling of powder and compacts which resulted in a very high level of air-borne activity. This has been simplified by integrating both the operations into one work centre on both the precompaction presses. In the present system, UO 2 powder is transferred to feed hopper through the use of high vac. feeder. The powder in metered quantities is fed into the shoe by deploying screw feeder driven by a compact hydraulic motor. The die cavity is filled with just the right quantity of powder to prevent spillage. The compacts are pushed on to the granulator through a set of guides mounted on the die platform. The granulated powder is made to pass through Vibro screen for separating the fines before collecting in a replaceable S.S. Container. This container is mounted on the final compacting press by using job crane installed on the press. The replaceable container handling facility drastically cuts down the manual handling of UO 2 granules and also eliminates spillage, air borne activity. The development and fabrication of hydraulically operated screw feeder, feed shoe, replaceable container and the job crane structure etc., were completely carried out at Nuclear Fuel Complex, Hyderabad. Paper deals in detail the design of the system developed, present operational experiences and further improvements planned. (author). 6 figs

  3. Metabolic changes induced by Bushenhouxue Granules on striatum ...

    African Journals Online (AJOL)

    Background: Parkinson's disease is a neurodegenerative disease, while its mechanism is still unclear. Long-term levodopa-based treatment leads to decreased response or loss of response, as well as severe side effects. Our previous study has proved that Bushenhuoxue Granules have effects on Parkinson's disease, but ...

  4. Effect of Drug Active Substance Particles on Wet Granulation Process.

    Czech Academy of Sciences Publication Activity Database

    Bělohlav, Z.; Břenková, L.; Hanika, Jiří; Durdil, P.; Rapek, P.; Tomášek, V.

    2007-01-01

    Roč. 85, A7 (2007) , s. 974-980 ISSN 0263-8762 Institutional research plan: CEZ:AV0Z40720504 Keywords : wet granulation * control * active substance Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 0.837, year: 2007

  5. 21 CFR 520.2520f - Trichlorfon granules.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Trichlorfon granules. 520.2520f Section 520.2520f Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL.... Do not fast horses before or after treatment. Treatment of mares in late pregnancy is not recommended...

  6. Glass foam granulate as growing medium for tomato and cucumber

    NARCIS (Netherlands)

    Blok, C.; Winkel, van A.; Chizhmak, S.

    2011-01-01

    Glass foam granulate was evaluated for use as a horticultural rooting medium with laboratory tests and cultivation experiments. The laboratory tests included moisture characteristics, rehydration rate and pH buffering analyses. Cucumbers and later on tomatoes were propagated in rockwool propagation

  7. Granulated blast furnace slag – A boon for foundry industry

    African Journals Online (AJOL)

    In the present investigation efforts have been put together to employ Granulated Blast furnace (GBF) slag as mould material for replacement of existing silica sand either full or partial in foundry industry. Nishiyama procedure was assumed for appraising the same. The process factors reflected on for this were the % of ...

  8. THE RELATIONSHIP BETWEEN BULK-DENSITY AND COMPACTIBILITY OF LACTOSE GRANULATIONS

    NARCIS (Netherlands)

    ZUURMAN, K; RIEPMA, KA; BOLHUIS, GK; VROMANS, H; LERK, CF

    1994-01-01

    The relationship between the bulk density and the compactibility of lactose granulations was studied. The granulations were prepared from different alpha-lactose monohydrate and roller dried beta-lactose powders by wet granulation, using different techniques with only water as a binder, or by

  9. TABLETING PROPERTIES OF EXPERIMENTAL AND COMMERCIALLY AVAILABLE LACTOSE GRANULATIONS FOR DIRECT COMPRESSION

    NARCIS (Netherlands)

    BOLHUIS, GK; ZUURMAN, K

    1995-01-01

    Lactose granulations (125-250 mu m) were prepared from two different alpha-lactose monohydrate powders and one roller dried beta-lactose powder respectively, by wet granulation with only water as a binder. As an effect of the granulation process, the flow properties improved, but the compactibility

  10. Microbial starch-binding domains as a tool for targeting proteins to granules during starch biosynthesis

    NARCIS (Netherlands)

    Ji, Q.; Vincken, J.P.; Suurs, L.C.J.M.; Visser, R.G.F.

    2003-01-01

    Modification of starch biosynthesis pathways holds an enormous potential for tailoring granules or polymers with new functionalities. In this study, we explored the possibility of engineering artificial granule-bound proteins, which can be incorporated in the granule during biosynthesis. The

  11. File list: Oth.Neu.05.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.Neu.05.AllAg.Cerebellar_granule_neurons mm9 TFs and others Neural Cerebellar granule neuron...s http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Oth.Neu.05.AllAg.Cerebellar_granule_neurons.bed ...

  12. File list: His.Neu.10.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  13. File list: His.Neu.05.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  14. File list: Oth.Neu.20.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

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  15. File list: ALL.Neu.50.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

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    Full Text Available ALL.Neu.50.AllAg.Cerebellar_granule_neurons mm9 All antigens Neural Cerebellar granule neuron...s SRX685885,SRX685882,SRX685880 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/ALL.Neu.50.AllAg.Cerebellar_granule_neurons.bed ...

  16. File list: Oth.Neu.50.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.Neu.50.AllAg.Cerebellar_granule_neurons mm9 TFs and others Neural Cerebellar granule neuron...s http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Oth.Neu.50.AllAg.Cerebellar_granule_neurons.bed ...

  17. File list: DNS.Neu.10.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available DNS.Neu.10.AllAg.Cerebellar_granule_neurons mm9 DNase-seq Neural Cerebellar granule neuron...s SRX685882,SRX685880,SRX685883,SRX685885,SRX685877,SRX685878 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/DNS.Neu.10.AllAg.Cerebellar_granule_neurons.bed ...

  18. File list: Unc.Neu.50.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Unc.Neu.50.AllAg.Cerebellar_granule_neurons mm9 Unclassified Neural Cerebellar granule neuron...s http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Unc.Neu.50.AllAg.Cerebellar_granule_neurons.bed ...

  19. The consequences of granulate heterogeneity towards breakage and attrition upon fluid-bed drying

    NARCIS (Netherlands)

    Nieuwmeyer, Florentine; Maarschalk, Kees van der Voort; Vromans, Herman

    High-shear granulated lactose granulates were dried in it fluid-bed dryer at various conditions. Granules were characterized by water content and size analysis. It is shown that the drying process is very dynamic in terms of growth and breakage phenomena. Granular size heterogeneity, composition and

  20. File list: DNS.Neu.50.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available DNS.Neu.50.AllAg.Cerebellar_granule_neurons mm9 DNase-seq Neural Cerebellar granule... neurons SRX685885,SRX685882,SRX685880 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/DNS.Neu.50.AllAg.Cerebellar_granule_neurons.bed ...

  1. File list: His.Neu.50.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

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    Lifescience Database Archive (English)

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  14. Continuous and sustainable granulation of nanopharmaceuticals by spray coagulation encapsulation in alginate.

    Science.gov (United States)

    Hadinoto, Kunn; Yang, Yue

    2014-10-01

    Nanopharmaceuticals (NPs) have emerged as an attractive formulation strategy for bioavailability enhancement of poorly soluble drugs. Their oral solid dosage form preparation requires them to undergo granulation before they can be processed into tablets. Existing NP granulation methods (e.g., spray drying, spray granulation), however, are lacking in sustainability due to their high energy expense and low mass efficiency. Herein we developed a one-step continuous NP granulation process via encapsulation by spray coagulation (ESC) in alginate, which transforms the NP immediately upon their preparation, thus removing the need for NP recovery prior to granulation, resulting in a highly sustainable process. Moreover, unlike spray-dried NP granules, the ESC-prepared granules are readily compacted into tablets owed to their larger size, thus further enhancing the overall sustainability of the solid dosage form preparation. Crystalline fenofibrate nanoparticles prepared by confined impinging jet crystallization were used as the model NP. Granules containing 25% NPs by mass with size ≈ 300 ± 100 μm were successfully prepared at >80% yield. The NPs maintain their fast dissolution (relative to native microcrystalline fenofibrate) after granulation. The tableted NP granules, having uniform dosage, exhibit similar drug release profiles as the free granules indicating complete granule disassociation from the tablets. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Fluidized bed granulation of an ordered powder mixture.

    Science.gov (United States)

    Thiel, W J; Nguyen, L T

    1982-11-01

    The phenomenon of ordered unit segregation is of paramount importance in determining the homogeneity of an ordered mixture. This problem can be avoided by using a monodisperse carrier, but it is uneconomic. The fluidized bed granulation of a 0.1% ordered mixture has been studied as a method of reducing the effects of segregation. The ordered units were stable when fluidized and no significant loss of the microfine adsorbed material occurred during processing. The distribution of the minor component in the granules was significantly more uniform than in the original ordered mixtures. The demixing potential (formula: see text) (where p = proportion of cohesive minor component and w is the weight % of carrier material in a particular size range) was used to quantify the distribution of the minor component as a function of particle size. DP is a coefficient of variation and can be directly compared with the specification standard deviation sigma A. Batches of granules were compressed into 100 or 350 mg tablets, containing approximately 100 and 350 micrograms of model drug substance. The weight and content coefficients of variation (c.v.) were determined for 20 tablets. All batches had a weight c.v. less than or equal to 1.5% and a content c.v. less than or equal to 4.6%. Granulation of an ordered mixture greatly reduces the potential for segregation to decrease the mixture homogeneity. It also provides a solution to the problems which may be encountered when the mixing of small quantities of cohesive materials during conventional fluidized bed granulation is attempted.

  16. Magnetic resonance microscopy of iron transport in methanogenic granules

    Science.gov (United States)

    Bartacek, Jan; Vergeldt, Frank J.; Gerkema, Edo; Jenicek, Pavel; Lens, Piet N. L.; Van As, Henk

    2009-10-01

    Interactions between anaerobic biofilms and heavy metals such as iron, cobalt or nickel are largely unknown. Magnetic resonance imaging (MRI) is a non-invasive method that allows in situ studies of metal transport within biofilm matrixes. The present study investigates quantitatively the penetration of iron (1.75 mM) bound to ethylenediaminetetraacetate (EDTA) into the methanogenic granules (spherical biofilm). A spatial resolution of 109 × 109 × 218 μm 3 and a temporal resolution of 11 min are achieved with 3D Turbo Spin Echo (TSE) measurements. The longitudinal relaxivity, i.e. the slope the dependence of the relaxation rate (1/ T1) on the concentration of paramagnetic metal ions, was used to measure temporal changes in iron concentration in the methanogenic granules. It took up to 300 min for the iron-EDTA complex ([FeEDTA] 2-) to penetrate into the methanogenic granules (3-4 mm in diameter). The diffusion was equally fast in all directions with irregularities such as diffusion-facilitating channels and diffusion-resistant zones. Despite these irregularities, the overall process could be modeled using Fick's equations for diffusion in a sphere, because immobilization of [FeEDTA] 2- in the granular matrix (or the presence of a reactive barrier) was not observed. The effective diffusion coefficient ( D ejf) of [FeEDTA] 2- was found to be 2.8 × 10 -11 m 2 s -1, i.e. approximately 4% of D ejf of [FeEDTA] 2- in water. The Fickian model did not correspond to the processes taking place in the core of the granule (3-5% of the total volume of the granule), where up to 25% over-saturation by iron (compare to the concentration in the bulk solution) occurred.

  17. GRANULATION AND BRIQUETTING OF SOLID PRODUCTS FROM FLUE GAS DESULFURIZATION

    Directory of Open Access Journals (Sweden)

    Jan J. Hycnar

    2015-11-01

    Full Text Available Most flue gas desulfurization products can be characterized by significant solubility in water and dusting in dry state. These characteristics can cause a considerable pollution of air, water, and soil. Among many approaches to utilization of this waste, the process of agglomeration using granulation or briquetting has proved very effective. Using desulfurization products a new material of aggregate characteristics has been acquired, and this material is resistant to water and wind erosion as well as to the conditions of transportation and storage. The paper presents the results of industrial trials granulation and briquetting of calcium desulphurization products. The granulation of a mixture of phosphogypsum used with fly ash (in the share 1:5. The resulting granules characterized by a compressive strength of 41.6 MPa, the damping resistance of 70% and 14.2% abrasion. The granulate was used for the production of cement mix. The produced concrete mortar have a longer setting and hardening time, as compared to the traditional ash and gypsum mortar, and have a higher or comparable flexural and compressive strength during hardening. Briquetting trials made of a product called synthetic gypsum or rea-gypsum both in pure form and with the addition of 5% and 10% of the limestone dust. Briquettes have a high initial strength and resistance to abrasion. The values ​​of these parameters increased after 72 hours of seasoning. It was found that higher hardiness of briquettes with rea-gypsum was obtained with the impact of atmospheric conditions and higher resistance to elution of water-soluble components in comparison to ash briquettes.

  18. Continuous wet granulation using fluidized-bed techniques. I. Examination of powder mixing kinetics and preliminary granulation experiments.

    Science.gov (United States)

    Gotthardt, S; Knoch, A; Lee, G

    1999-11-01

    The movement of powder/granules within the reaction chambers of two continuously-operating granulators (Niro/Aeromatic-Fielder Contipharm and the Glatt Continuous Fluidized-Bed Granulator) was examined by adding dyestuffs to the powder-inlet. Comparison of the dye mass-fraction in the product with the appropriate transport equation indicated random mixing and transport within the product-chamber. Photographs of powder movement on the gill-plate of the Contipharm showed, however, air-driven transport of powder from inlet to outlet, which evidently does not prevent overall random mixing. The output half-life is > 20 min, showing substantial residence time within each machine. A simplex granule was also prepared using the two machines. With the Niro it was shown that an increase in binder solution spraying rate during the continuous process produced an increase in particle size distribution and moisture content. Reduction of air volumetric flow rate on the Glatt machine during continuous operation produced higher moisture content of the product. It was thus demonstrated that changes in process conditions during continuous operation produce predictable alterations in product properties,

  19. Impact of fill-level in twin-screw granulation on critical quality attributes of granules and tablets.

    Science.gov (United States)

    Meier, Robin; Moll, Klaus-Peter; Krumme, Markus; Kleinebudde, Peter

    2017-06-01

    In a previous study a change of the fill-level in the barrel exerted a huge influence on the twin-screw granulation (TSG) process of a high drug loaded, simplified formulation. The present work investigated this influence systematically. The specific feed load (SFL) indicating the mass per revolution as surrogate parameter for the fill-level was applied and the correlation to the real volumetric fill level of an extruder could be demonstrated by a newly developed method. A design of experiments was conducted to examine the combined influence of SFL and screw speed on the process and on critical quality attributes of granules and tablets. The same formulation was granulated at constant liquid level with the same screw configuration and led to distinctively different results by only changing the fill-level and the screw speed. The power consumption of the extruder increased at higher SFLs with hardly any influence of screw speed. At low SFL the median residence time was mainly fill-level dependent and at higher SFL mainly screw speed dependent. Optimal values for the product characteristics were found at medium values for the SFL. Granule size distributions shifted from mono-modal and narrow shape to broader and even bimodal distributions of larger median granule sizes, when exceeding or falling below a certain fill-level. Deviating from the optimum fill-level, tensile strength of tablets decreased by about 25% and disintegration times of tablets increased for more than one third. At low fill-levels, material accumulation in front of the kneading zone was detected by pressure measurements and was assumed to be responsible for the unfavored product performance. At high fill-levels, granule consolidation due to higher propensity of contact with the result of higher material temperature was accounted for inferior product performance. The fill-level was found to be an important factor in assessment and development of twin-screw granulation processes as it impacted

  20. Production of Polyhydroxyalkanoates Using Hydrolyzates of Spruce Sawdust: Comparison of Hydrolyzates Detoxification by Application of Overliming, Active Carbon, and Lignite

    Directory of Open Access Journals (Sweden)

    Dan Kucera

    2017-05-01

    Full Text Available Polyhydroxyalkanoates (PHAs are bacterial polyesters which are considered biodegradable alternatives to petrochemical plastics. PHAs have a wide range of potential applications, however, the production cost of this bioplastic is several times higher. A major percentage of the final cost is represented by the price of the carbon source used in the fermentation. Burkholderia cepacia and Burkholderia sacchari are generally considered promising candidates for PHA production from lignocellulosic hydrolyzates. The wood waste biomass has been subjected to hydrolysis. The resulting hydrolyzate contained a sufficient amount of fermentable sugars. Growth experiments indicated a strong inhibition by the wood hydrolyzate. Over-liming and activated carbon as an adsorbent of inhibitors were employed for detoxification. All methods of detoxification had a positive influence on the growth of biomass and PHB production. Furthermore, lignite was identified as a promising alternative sorbent which can be used for detoxification of lignocellulose hydrolyzates. Detoxification using lignite instead of activated carbon had lower inhibitor removal efficiency, but greater positive impact on growth of the bacterial culture and overall PHA productivity. Moreover, lignite is a significantly less expensive adsorbent in comparison with activated charcoal and; moreover, used lignite can be simply utilized as a fuel to, at least partially, cover heat and energetic demands of fermentation, which should improve the economic feasibility of the process.

  1. Simplified recovery process of Ralstonia solanacearum-synthesized polyhydroxyalkanoates via chemical extraction complemented by liquid-liquid phase separation

    Directory of Open Access Journals (Sweden)

    Karine L. Macagnan

    Full Text Available Poly (3-hydroxybutyrate (P(3HB is the most studied thermoplastic biopolymer belonging to the polyhydroxyalkanoate (PHA family, the main features of which include rapid biodegradability and biocompatibility. The bioplastic recovery process is an important step during production and can directly influence the characteristics of PHAs. However, more efficient methods for the production of P(3HB are necessary to make it economically viable. The aim of the present study was to improve the standard, chloroform-based, extraction step for the recovery of P(3HB. The polymer was produced using a Ralstonia solanacearum strain. The following parameters were improved in the recovery process: heating time, separation method (filtration or liquid-liquid phase separation, biomass state (fresh or dry cell concentrate and the solvent:biomass ratio. By improving the chemical extraction of P(3HB we recovered 98% of the cumulative polymer and reduced the heating time by 75%. Furthermore, we improved the separation process and developed an extraction solution that was faster and more economical.

  2. Production of Polyhydroxyalkanoates Using Hydrolyzates of Spruce Sawdust: Comparison of Hydrolyzates Detoxification by Application of Overliming, Active Carbon, and Lignite

    Science.gov (United States)

    Kucera, Dan; Benesova, Pavla; Ladicky, Peter; Pekar, Miloslav; Sedlacek, Petr; Obruca, Stanislav

    2017-01-01

    Polyhydroxyalkanoates (PHAs) are bacterial polyesters which are considered biodegradable alternatives to petrochemical plastics. PHAs have a wide range of potential applications, however, the production cost of this bioplastic is several times higher. A major percentage of the final cost is represented by the price of the carbon source used in the fermentation. Burkholderia cepacia and Burkholderia sacchari are generally considered promising candidates for PHA production from lignocellulosic hydrolyzates. The wood waste biomass has been subjected to hydrolysis. The resulting hydrolyzate contained a sufficient amount of fermentable sugars. Growth experiments indicated a strong inhibition by the wood hydrolyzate. Over-liming and activated carbon as an adsorbent of inhibitors were employed for detoxification. All methods of detoxification had a positive influence on the growth of biomass and PHB production. Furthermore, lignite was identified as a promising alternative sorbent which can be used for detoxification of lignocellulose hydrolyzates. Detoxification using lignite instead of activated carbon had lower inhibitor removal efficiency, but greater positive impact on growth of the bacterial culture and overall PHA productivity. Moreover, lignite is a significantly less expensive adsorbent in comparison with activated charcoal and; moreover, used lignite can be simply utilized as a fuel to, at least partially, cover heat and energetic demands of fermentation, which should improve the economic feasibility of the process. PMID:28952532

  3. Production of polyhydroxyalkanoates (PHA) using sludge from different wastewater treatment processes and the potential for medical and pharmaceutical applications.

    Science.gov (United States)

    Lam, Wai; Wang, Yujie; Chan, Pui Ling; Chan, Shun Wan; Tsang, Yiu Fai; Chua, Hong; Yu, Peter Hoi Fu

    2017-07-01

    In this study, seven strains of bacteria with polyhydroxyalkanoates (PHA)-producing ability (i.e. Bacillus cereus, Pseudomonas putida, Bacillus pumilus, Pseudomona huttiensis, Yersinia frederiksenii, Aeromonas ichthiosmia, and Sphingopyxis terrae) were isolated from various waste treatment plants in Hong Kong. Simultaneous wastewater treatment and PHA accumulation were successfully achieved in the bioreactors using isolated bacteria from different sludges. At the organic loading less than 13,000 ppm, more than 95% of chemical oxygen demand (COD) was removed by the isolated strains before the decrease of PHA accumulation. In addition, more than 95% of nitrogen removal was achieved by all isolated strains. In the bioreactors inoculated with single strains, the highest yields of poly(3-hydroxybutyrate) (PHB) and poly(3-hydroxyvalerate) (PHV) were obtained in A. ichthiosmia (84 mg PHB/g) and B. cereus (69 mg/g), respectively. For the mixed culture, the highest yields of PHB and PHV were increased by 55% and 45% in the system inoculated with B. pumilus and A. ichthiosmia. The biologically synthesized PHA also showed the potential applications in drug delivery and tissue engineering. PHA-nanoparticles loaded with pyrene were successfully prepared by recombinant Escherichia coli. The results of in vitro drug release and biocompatibility tests revealed that nanoparticles could be used as safer dray carriers with high loading capacity and efficiency. After 20 days, the cells successfully grew on 90% of the PHA-aortic valve.

  4. The influence of substrate source on the growth of Ralstonia eutropha, aiming at the production of polyhydroxyalkanoate

    Directory of Open Access Journals (Sweden)

    Marangoni C.

    2001-01-01

    Full Text Available With the aim of producing polyhydroxyalkanoates, a study of the influence of culture conditions (nitrogen and carbon sources and temperature on the growth of Ralstonia eutropha in stirred flasks was carried out and the use of some low-cost sources (hydrolyzed lactose, inverted sugar and corn steep liquor as evaluated. The best specific growth rate was obtained when inverted sugar was utilized as the substrate (mumax = 0.26 h-1. Two different phases in the assimilation of the carbon source were observed when hydrolyzed lactose was present, suggesting the assimilation first of glucose and then of galactose. To confirm the growth of Ralstonia eutropha using galactose as the only carbon source, experiments were carried out and the results showed that this bacterium is able to grow in the presence of this sugar at a growth rate of 0.13 h-1. The use of galactose by Ralstonia eutropha for its growth has not been reported in the literature until now. Corn steep liquor was found to be a viable alternative nitrogen source to ammonium sulfate. The results of experiments carried out at 30°C and 34°C were similar.

  5. Enhancing the Production of Polyhydroxyalkanoate Biopolymer by Azohydromonas Australica Using a Simple Empty and Fill Bioreactor Cultivation Strategy

    Directory of Open Access Journals (Sweden)

    G. Gahlawat

    2018-01-01

    Full Text Available Polyhydroxyalkanoates (PHAs are biodegradable polymers which are considered as an effective alternative for conventional plastics due to their mechanical properties similar to the latter. However, widespread use of these polymers is still hampered due to their high cost of production. This shortcoming could partly be resolved by obtaining high yields and productivity. In the present study, a drain-and-fill strategy of repeated-batch cultivation was adopted for the enhanced production of polyhydroxybutyrate PHB using Azohydromonas australica. In this strategy, 20 % (v/v of the culture broth was removed from the reactor and supplemented with an equal volume of fresh medium. This strategy demonstrated a 3.3 fold and 1.8 fold increase in PHB concentration and productivity, respectively, as compared to batch cultivation. Repeated cultivation had also the benefit of avoiding non-productive time required for cleaning, refilling and sterilization of bioreactor during batch, thereby increasing the overall volumetric productivity and industrial importance of the process.

  6. New Bio-Composites Based on Polyhydroxyalkanoates and Posidonia oceanica Fibres for Applications in a Marine Environment

    Science.gov (United States)

    Seggiani, Maurizia; Cinelli, Patrizia; Mallegni, Norma; Balestri, Elena; Puccini, Monica; Vitolo, Sandra; Lardicci, Claudio; Lazzeri, Andrea

    2017-01-01

    Bio-composites based on polyhydroxyalkanoates (PHAs) and fibres of Posidonia oceanica (PO) were investigated to assess their processability by extrusion, mechanical properties, and potential biodegradability in a natural marine environment. PHAs were successfully compounded with PO fibres up to 20 wt % while, at 30 wt % of fibres, the addition of 10 wt % of polyethylene glycol (PEG 400) was necessary to improve their processability. Thermal, rheological, mechanical, and morphological characterizations of the developed composites were conducted and the degradation of composite films in a natural marine habitat was evaluated in a mesocosm by weight loss measure during an incubation period of six months. The addition of PO fibres led to an increase in stiffness of the composites with tensile modulus values about 80% higher for composites with 30 wt % fibre (2.3 GPa) compared to unfilled material (1.24 GPa). Furthermore, the impact energy markedly increased with the addition of the PO fibres, from 1.63 (unfilled material) to 3.8 kJ/m2 for the composites with 30 wt % PO. The rate of degradation was markedly influenced by seawater temperature and significantly promoted by the presence of PO fibres leading to the total degradation of the film with 30 wt % PO in less than six months. The obtained results showed that the developed composites can be suitable to manufacture items usable in marine environments, for example, in natural engineering interventions, and represent an interesting valorisation of the PO fibrous wastes accumulated in large amounts on coastal beaches. PMID:28772689

  7. Microbial community-based polyhydroxyalkanoates (PHAs) production from wastewater: Techno-economic analysis and ex-ante environmental assessment.

    Science.gov (United States)

    Fernández-Dacosta, Cora; Posada, John A; Kleerebezem, Robbert; Cuellar, Maria C; Ramirez, Andrea

    2015-06-01

    This work investigates the potential for polyhydroxybutyrate (PHB) production from wastewater, from a techno-economic and an environmental perspective, examining scale-up opportunities and bottlenecks prior to commercialisation. Conceptual process design, economic, environmental impacts and sensitivity analysis are developed for one fermentation process and three downstream processing routes, based on alkali, surfactant-hypochlorite and solvent treatments. Environmentally and cost-wise, the alkali treatment is the most favourable with production costs of 1.40€/kg PHB, global warming potential of 2.4kgCO2-eq/kg PHB and non-renewable energy use of 106MJ/kg PHB. The solvent-based process yields the highest costs and environmental burdens: 1.95€/kg PHB, 4.30kgCO2-eq/kg PHB and 156MJ/kg PHB. The production of PHB from wastewater is identified as an interesting alternative to pure culture-polyhydroxyalkanoates production from sugars. However, these results are not yet competitive with those for the petrochemical counterparts. Additional performance improvements may be possible, through process integration and optimisation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Liquefied Wood as Inexpensive Precursor-Feedstock for Bio-Mediated Incorporation of (R-3-Hydroxyvalerate into Polyhydroxyalkanoates

    Directory of Open Access Journals (Sweden)

    Martin Koller

    2015-09-01

    Full Text Available Liquefied wood (LW prepared in a microwave process was applied as a novel; inexpensive precursor feedstock for incorporation of (R-3-hydroxyvalerate (3HV into polyhydroxyalkanoate (PHA biopolyesters in order to improve the biopolyester’s material quality; Cupriavidus necator was applied as microbial production strain. For proof of concept, pre-experiments were carried out on a shake flask scale using different mixtures of glucose and LW as carbon source. The results indicate that LW definitely acts as a 3HV precursor, but, at the same time, displays toxic effects on C. necator at concentrations exceeding 10 g/L. Based on these findings, PHA biosynthesis under controlled conditions was performed using a fed-batch feeding regime on a bioreactor scale. As major outcome, a poly(3HB-co-0.8%-3HV copolyester was obtained displaying a desired high molar mass of Mw = 5.39 × 105 g/mol at low molar-mass dispersity (ĐM of 1.53, a degree of crystallinity (Xc of 62.1%, and melting temperature Tm (176.3 °C slightly lower than values reported for poly([R]-3-hydroxybutyrate (PHB homopolyester produced by C. necator; thus, the produced biopolyester is expected to be more suitable for polymer processing purposes.

  9. Glycerine and levulinic acid: renewable co-substrates for the fermentative synthesis of short-chain poly(hydroxyalkanoate) biopolymers.

    Science.gov (United States)

    Ashby, Richard D; Solaiman, Daniel K Y; Strahan, Gary D; Zhu, Chengjun; Tappel, Ryan C; Nomura, Christopher T

    2012-08-01

    Glycerine (a biodiesel co-product) and levulinic acid (a pulp and paper co-product) were used as co-substrates for the fermentative synthesis of short-chain polyhydroxyalkanoate (sc-PHA) biopolymers with tunable monomer and molecular weight characteristics. Pseudomonas oleovorans NRRL B-14682 utilized glycerine alone to produce poly(3-hydroxybutyrate) (PHB). When levulinic acid was added to the media at shake-flask scale in concentrations ≤0.6 wt.%, poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHB/V) copolymers were produced with 3-HV contents ranging from 37 to 97 mol%; a glycerine:levulinic acid ratio of 0.2%:0.8% (w/v) resulted in poly(3-hydroxyvalerate) (PHV). Ten-liter batch fermentations using glycerine:levulinic acid ratios of 1%:0, 0.75%:0.25%, 0.5%:0.5% and 0.25%:0.75% (w/v) resulted in PHB, P(73%-3HB-co-27%-3HV), P(30%-3HB-co-70%-3HV) and PHV with increasing number average molecular weights (×10(3) g/mol) of 328, 511, 728 and 1330, respectively, owing to glycerine-based chain termination. These results provide a novel means by which glycerine and levulinic acid can be used collectively to produce an array of distinct sc-PHA biopolymers. Published by Elsevier Ltd.

  10. Polyhydroxyalkanoate (PHA) accumulation potential and PHA-accumulating microbial communities in various activated sludge processes of municipal wastewater treatment plants.

    Science.gov (United States)

    Sakai, K; Miyake, S; Iwama, K; Inoue, D; Soda, S; Ike, M

    2015-01-01

    To clarify the polyhydroxyalkanoate (PHA) accumulation potential and the PHA-accumulating microbial community structure in activated sludge in municipal wastewater treatment plants (WWTPs) and to identify their influential factors. Nine activated sludge samples were collected from municipal WWTPs employing various biological treatment processes. In acetate-fed 24-h batch experiments under aerobic and nitrogen- and phosphorus-limited conditions, polyhydroxybutyrate (PHB) content of activated sludge increased from 0-1·3 wt% to 7·9-24 wt%, with PHB yields of 0·22-0·50 C-mol 3-hydroxybutyrate (C-mol acetate)(-1). Microbial community analyses found that activated sludge samples that accumulated >20 wt% of PHB after 24-h PHA accumulation experiments had >5·0 × 10(8) copies g(-1)-mixed liquor-suspended solid of phaC genes. Results indicated that (i) activated sludge in municipal WWTPs can accumulate up to approx. 20 wt% of PHA without enrichment processes, (ii) PHA accumulation potential of activated sludge varied depending on the operational conditions (treatment processes) of WWTPs, and (iii) phaC gene number can provide a simple indication of PHA accumulation potential. This is the first study to compare the PHA accumulation potential and PHA-accumulating microbial communities in activated sludge of various treatment processes. Our findings may be useful for enhancing the resource recovery potential of wastewater treatment systems. © 2014 The Society for Applied Microbiology.

  11. Comprehensive utilization of activated sludge for the preparation of hydrolytic enzymes, polyhydroxyalkanoates, and water-retaining organic fertilizer.

    Science.gov (United States)

    Ni, He; Fan, Xiao-Min; Guo, Hao-Ning; Liang, Jian-Hua; Li, Qing-Rong; Yang, Liu; Li, Hui; Li, Hai-Hang

    2017-07-03

    The urban wastewater treatment industry produces a large amount of excess activated sludge which is mainly composed of microbial biomass and costly to be disposed. In this research, a comprehensive utilization of activated sludge was developed by sequentially extracting hydrolytic enzymes and polyhydroxyalkanoates (PHAs), and the residue was used to prepare water-retaining organic fertilizer. The sludge was extracted with fourfold H 2 O-containing 1% Triton X-100 with the yield of 66.7% protease activity. The enzyme solution was precipitated in 80% acetone and vacuum dried at 40°C at the dried enzyme yield of 2.4 g/kg wet sludge. The enzyme product contains collagenase, lipase, amylase, and cellulase activities, which are good compound enzymes to feed. The PHAs were extracted with 30% sodium hypoclorite:chloroform (1:3). The PHA solution was decolored and dried, and pure white PHAs were obtained at the yield of 70.1 g/kg wet sludge. The residue was used to prepare water-retaining organic fertilizer at the optimal condition. The fertilizer absorbs 131.3-fold distilled water and had good performance in water retention and can effectively slow down the loss of soil moisture when added into soil. This work provides a simple and practical approach for comprehensive utilizing activated sludge with significant economic benefits.

  12. Nutrient optimization of polyhydroxyalkanoate production from palm oil fiber by Ralstonia eutropha TISTR 1095 using response surface methodology

    Directory of Open Access Journals (Sweden)

    Piyarat Boonsawang

    2010-03-01

    Full Text Available Polyhydroxyalkanoate (PHA is polyesters formed in several bacteria as a carbon or energy storage under some nutrientlimitation. Ralstonia eutropha has potential to produce PHA from various substrates, including carboxylic acids. In this research,the nutrient optimum to produce PHA from carboxylic acid was studied by using response surface methodology. Thecarboxylic acids were produced by anaerobic palm oil fiber fermentation for 7 days. Then Ralstonia eutropha TISTR 1095was cultured in fermented broth containing 840 mg/l of acids. The interaction of two factors at the same time was investigated.The effects of propionic acid, butyric acid, (NH42SO4 and K2HPO4 addition were examined. The result showed that the nutrient optimum for PHA production was fermented broth with nutrient addition (2.50 g/l propionic acid, 6.53 g/l butyric acid,1.53 g/l, (NH42SO4 and 0.03 g/l K2HPO4. The cell concentration, PHA concentration, and PHA content were 1.53 g/l, 0.70 g/l and 46.5%, respectively

  13. The use of Rheology Combined with Differential Scanning Calorimetry to Elucidate the Granulation Mechanism of an Immiscible Formulation During Continuous Twin-Screw Melt Granulation.

    Science.gov (United States)

    Monteyne, Tinne; Heeze, Liza; Mortier, Severine Therese F C; Oldörp, Klaus; Cardinaels, Ruth; Nopens, Ingmar; Vervaet, Chris; Remon, Jean-Paul; De Beer, Thomas

    2016-10-01

    Twin screw hot melt granulation (TS HMG) is a valuable, but still unexplored alternative to continuous granulation of moisture sensitive drugs. However, knowledge of the material behavior during TS HMG is crucial to optimize the formulation, process and resulting granule properties. The aim of this study was to evaluate the agglomeration mechanism during TS HMG using a rheometer in combination with differential scanning calorimetry (DSC). An immiscible drug-binder formulation (caffeine-Soluplus(®)) was granulated via TS HMG in combination with thermal and rheological analysis (conventional and Rheoscope), granule characterization and Near Infrared chemical imaging (NIR-CI). A thin binder layer with restricted mobility was formed on the surface of the drug particles during granulation and is covered by a second layer with improved mobility when the Soluplus(®) concentration exceeded 15% (w/w). The formation of this second layer was facilitated at elevated granulation temperatures and resulted in smaller and more spherical granules. The combination of thermal and rheological analysis and NIR-CI images was advantageous to develop in-depth understanding of the agglomeration mechanism during continuous TS HMG and provided insight in the granule properties as function of process temperature and binder concentration.

  14. A process to produce effervescent tablets: fluidized bed dryer melt granulation.

    Science.gov (United States)

    Yanze, F M; Duru, C; Jacob, M

    2000-11-01

    The purpose of the present study was to apply melt granulation in a fluidized bed dryer (fluidized bed dryer melt granulation) to manufacture one-step effervescent granules composed of anhydrous citric acid and sodium bicarbonate to make tablets. This study permitted us to establish that such process parameters as concentrations of polyethylene glycol (PEG) 6000, residence times in the fluidized bed dryer, fineness of PEG6000, fineness of initial mixture effervescent systems, and efficiency of two lubricants markedly affect some granule and tablet characteristics. It is a dry process that is simple, rapid, effective, economical, reproducible, and particularly adapted to produce effervescent granules that are easily compressed into effervescent tablets.

  15. Air-dictated bottom spray process: impact of fluid dynamics on granule growth and morphology.

    Science.gov (United States)

    Liew, Celine V; Er, Dawn Z L; Heng, Paul W S

    2009-07-01

    Growing interest in the use of the less-explored bottom spray technique for fluidized bed granulation provided impetus for this study. The impact of fluid dynamics (air accelerator insert diameter; partition gap) and wetting (binder spray rate) on granule properties were investigated. In this 3(3) full factorial study, the results were fitted to a quadratic model using response surface methodology. The air velocity at the spray granulation zone for the investigated conditions was measured using a pitot tube. Air accelerator insert diameter correlated to measured air velocity at the spray granulation zone and was found to not only dictate growth but also influence granule morphology. The partition gap was found to play important roles in regulating particle movement into the spray granulation zone and optimizing process yields, whereas binder spray rate significantly affected granule morphology but not granule size. Unlike conventional fluidized bed granulation, ease of modulation of fluid dynamics and insensitivity of the bottom spray process to wetting allow flexible control of granule size, shape, and flow. Its good drying ability also indicated potential use in granulating moisture-sensitive materials.

  16. Study growth kinetics in fluidized bed granulation with at-line FBRM.

    Science.gov (United States)

    Hu, Xinhui; Cunningham, John C; Winstead, Denita

    2008-01-22

    In this study, a novel at-line focused beam reflectance measurement (FBRM) technique was developed to investigate granule growth in a fluidized bed granulation (FBG). The chord length distribution (CLD) measured by the FBRM was used to represent granule particle size distribution (PSD). Through a systematic study, it was proved that the trends of the chord length measured by the at-line FBRM technique were identical to those measured by a laser diffraction instrument and sieve analysis in spite of different measurement mechanisms. The portable at-line FBRM technique was successfully applied to a granule growth kinetics study for a fluidized bed granulation performed in a Glatt GPCG-1 granulator. Granule size evolution was clearly exhibited by the at-line FBRM. Spray rate was found to be the most significant factor on the granule growth compared with the other two factors: binder solution concentration and intra- to extra-granular microcrystalline cellulose (MCC) ratio for the formulation studied in this work. The CLD evolution measured by the FBRM confirmed that the granule agglomeration was mainly dominated by the binder on the granule surface. The at-line FBRM enables us to select appropriate process parameters and effectively control the fluid bed granulation process.

  17. Use of the near-infrared reflectance method for measurement of moisture content during granulation.

    Science.gov (United States)

    Rantanen, J; Antikainen, O; Mannermaa, J P; Yliruusi, J

    2000-01-01

    The purpose of this study was to demonstrate the use of a near-infrared (NIR) method for in-process control of a placebo formulation. An NIR setup with a multichannel detector was applied in the measurement of water during fluidized bed granulation. The effects of two critical granulation parameters were studied using the central composite design. The present NIR setup with three wavelengths proved applicable for in-line moisture measurement. The 1990 nm signal was used for measurement of water and the 1745 and 2145 nm signals were used to correct the change in spectra baseline during granulation. Variations in inlet air conditions proved to be critical factors, explaining differences in the granule size distributions. Differences in granule moistening and drying rates resulting from varying inlet air conditions could be measured with the NIR setup. The moisture content of granules at the end of the spraying phase explained part of the differences in granule size distributions. The moisture content of granules at the end of the drying phase affected the tableting behavior of granules. The results suggested that direct measurement of granule moisture content facilitates the in-process control of the granulation.

  18. Investigation on side-spray fluidized bed granulation with swirling airflow.

    Science.gov (United States)

    Wong, Poh Mun; Chan, Lai Wah; Heng, Paul Wan Sia

    2013-03-01

    Top-spray fluidized bed granulation with axial fluidization airflow from the bottom of the granulator is well-established in the pharmaceutical industry. The application of swirling airflow for fluidized bed granulation was more recently introduced. This study examined the effects of various process parameters on the granules produced by side-spray fluidized bed with swirling airflow using the central composite and Box-Behnken design of experiment. Influence of the amount of binder solution, spray rate, and distance between spray nozzle and powder bed were initially studied to establish operationally viable values for these parameters. This was followed by an in-depth investigation on the effects of inlet airflow rate, atomizing air pressure and distance between spray nozzle and powder bed on granule properties. It was found that the amount of binder solution had a positive correlation with granule size and percentage of lumps but a negative correlation with size distribution and Hausner ratio of the granules. Binder solution spray rate was also found to affect the granules size. High drug content uniformity was observed in all the batches of granules produced. Both inlet airflow rate and atomizing air pressure were found to correlate negatively with granule size and percentage of lumps but correlate positively with the size distribution of the granule produced. Percentage of fines was found to be significantly affected by inlet airflow rate. Distance between spray nozzle and powder bed generally affected the percentage of lumps.

  19. Statistical properties of solar granulation from the SOUP instrument on Spacelab 2

    Science.gov (United States)

    Topka, K.; Title, A.; Tarbell, T.; Ferguson, S.; Shine, R.

    1988-01-01

    The Solar Optical Universal Polarimeter (SOUP) on Spacelab 2 collected movies of solar granulation completely free from atmospheric blurring, and are not degraded by pointint jitter (the pointing stability was 0.003 sec root mean square). The movies illustrate that the solar five minute oscillation has a major role in the appearance of solar granulation and that exploding granules are a common feature of the granule evolution. Using 3-D Fourier filtering techniques the oscillations were removed and it was demonstrated that the autocorrelation lifetime of granulation is a factor of two greater in magnetic field regions than in field-free quiet sun. Horizontal velocities were measured and flow patterns were observed on the scale of meso- and super granulation. In quiet regions the mean flow velocity is 370 m/s while in the magnetic regions it is about 125 m/s. It was also found that the root mean square (RMS) fluctuating horizonal velocity field is substantially greater in quiet sun than in strong magnetic field regions. By superimposing the location of exploding granules on the average flow maps it was found that they appear almost exclusively in the center of mesogranulation size flow cells. Because of the nonuniformity of the distribution of exploding granules, the evolution of the granulation pattern in mesogranule cell centers and boundaries differs fundamentally. It is clear from this study there is neither a typical granule nor a typical granule evolution.

  20. Assessment of granulation technologies for an API with poor physical properties.

    Science.gov (United States)

    Dalziel, Gena; Nauka, Ewa; Zhang, Feng; Kothari, Sanjeev; Xie, Minli

    2013-07-01

    Granulation technologies are widely used in solid oral dosage forms to improve the physical properties during manufacture. Wet, dry, and melt granulation techniques were assessed for Compound A, a BCS class II compound. Characterization techniques were used to quantify physical property limitations inherent for Compound A including hygroscopicity, low solubility and bulk density, and poor powder flowability. High shear aqueous wet granulation induced an undesirable water mediated phase transition of the solid form. A formulation and process for dry granulation by roller compaction was developed and scaled to 10 kg batch size. Roll force, and roll gap parameters were assessed. Porosity of compacted ribbons was analyzed by mercury intrusion porosimetry, and particle size distributions of milled ribbons by sieve analysis. A roll force of 15 kN/cm produced granules with higher density and improved flow properties compared to the pre-blend. Fines content (granulation to 26% post-granulation. Cohesive properties of Compound A limited drug loading (API:excipient ratio) in roller compaction to 0.6:1 or less. Hot melt granulation by extrusion assessed with four polymers. A vast improvement in drug loading of 4:1 was achieved via melt processes using low molecular weight thermo-binders (glyceryl behenate and Polyethylene glycol 4000). Granules produced by melt processing contained less fines compared to wet and dry granulation. Both roller compaction and melt extrusion are viable granulation process alternatives for scale up to overcome the physical property limitations of Compound A.

  1. GRANULATION TRIALS OF WASTE THE DUST SILICON CARBIDE FOR UTILIZATION IN METALLURGY

    Directory of Open Access Journals (Sweden)

    Gabriel Borowski

    2016-09-01

    Full Text Available The article presents the results of laboratory granulation tests of dust silicon carbide and the results of research on the selection of the binder and the properties of the granules obtained. The research material was a waste of the silicon carbide powder with a high fragmentation, mixed with a cement or an organic modified starch specimen. Six tests were performed in a disc granulator with 100 cm in diameter. In each series of trial specified: the type and share of the binder, the diameter of the granules, tenderness, type of structure and mechanical properties. Good granules of silicon carbide obtained with the addition of cement binder with 4% of the mass fraction and at least 24 hours of seasoning. The binder should be added twice by powdering, first in a stirred granulator, and again after manufacture. It was found that the resulting granules may be used as a replacement of ferrosilicon in the process of steelmaking.

  2. Study of Viability of Phosphate Solubilizing Bacteria in Phosphate granules

    Directory of Open Access Journals (Sweden)

    hajar rajabi

    2017-06-01

    Full Text Available Introduction: sustainable development and the environment are interconnected. Sustainable agriculture is continuous utilization of a farm with respect to various aspects of environmental conditions by using fewer inputs (other than Bio-fertilizers. Phosphorus is one of the essential elements for the plants. Management of soil is possible by using biological fertilizers pillar of sustainable agriculture and providing some of the phosphorus needed by plants via bio-fertilizers. Phosphorus deficiency is extremely effective on the plant growth and productivity. The application of phosphorus fertilizers is expensive and dangerous. In addition, phosphorus in the soilmay become insoluble and will be unavailable to the plants. Studies showed that phosphate solubilizing bacteria in the soil rhizosphere are active and by root exudates solve insoluble phosphates such as tricalcium phosphate, and form absorbable P for plant. Consequently, the use of microbial fertilizers could reduce excessive use of chemical fertilizers and lead to decrease their harmful effects and protect the environment and conservation of available resources. The biological phosphate fertilizer industry uses sugar beet molasses as a binder and drying granules at high temperatures. Therefore, it is important to evaluate the durability of the bacteria in molasses at high temperature. Materials and Methods: This study was designed as completely randomized design in a factorial arrangement.10 isolates were selected and the ratios of 50%, 25%, 15% and 10% of the apatite, organic matter, sulfur and soluble granule (ratio 1: 1 and 2: 1 bacteria and molasses, respectively, for each isolate was prepared. The final product was dried at 28 and 40 °C and remained for 4 months and population counted at first day and 10, 20, 30, 60, 90 and 120 days after the preparing. The population was counted by the serial dilution technique and cultured at Sperber media. Results and Discussion:Comparing the

  3. Controlling granule size through breakage in a novel reverse-phase wet granulation process: the effect of impeller speed and binder liquid viscosity.

    Science.gov (United States)

    Wade, J B; Martin, G P; Long, D F

    2015-01-30

    The feasibility of a novel reverse-phase wet granulation process has been established previously highlighting several potential advantages over the conventional wet granulation process and making recommendations for further development of the approach. The feasibility study showed that in the reverse-phase process granule formation proceeds via a controlled breakage mechanism. Consequently, the aim of the present study was to investigate the effect of impeller speeds and binder liquid viscosity on the size distribution and intragranular porosity of granules using this novel process. Impeller tip speed was found to have different effects on the granules produced by a conventional as opposed to a reverse-phase granulation process. For the conventional process, an increase in impeller speed from 1.57 to 3.14 ms(-1) had minimal effect on granule size distribution. However, a further increase in impeller tip speed to 3.93 and 4.71 ms(-1) resulted in a decrease in intragranular porosity and a corresponding increase in mean granule size. In contrast when the reverse-phase process was used, an increase in impeller speed from 1.57 to 4.71 ms(-1) resulted in increased granule breakage and a decrease in the mean granule size. This was postulated to be due to the fact that the granulation process begins with fully saturated pores. Under these conditions further consolidation of granules at increased impeller tip speeds is limited and rebound or breakage occurs. Based on these results and analysis of the modified capillary number the conventional process appears to be driven by viscous forces whereas the reverse-phase process appears to be driven by capillary forces. Additionally, in the reverse-phase process a critical impeller speed, represented by the equilibrium between centrifugal and gravitational forces, appears to represent the point above which breakage of large wet agglomerates and mechanical dispersion of binder liquid take place. In contrast the conventional process

  4. Organic-mineral binder for molybdenum concentrate granulation

    International Nuclear Information System (INIS)

    Guro, Vitaliy P.; Ibragimova, Matluba A.; Safarov, Edgorjon T.

    2016-01-01

    Process of pyrite cinders production from Mo middlings consists of molybdenite concentrate granulation, firing to oxidize sulfide minerals and to recover Re-oxide. If kaolin binder is used a pyrite cinders dilution with Mo takes place. So, the development of organic binding agents, alternative to kaolin, is an actual issue. The approach is based on the comparison of the hydrophilic, strength and technological features of the hydrometallurgical processing of pellets. The new batch is developed. It differs from the traditional mixture by polymer burning and minimizing Mo dilution, thus aiming to maximize Re, Au, Ag recovery. The composition of the new organic-mineral batch is as follows: 97.3 % of molybdenite concentrate, 2 % of kaolin and 0.7 % of SK polymer. Keywords: molybdenum middlings, binder, organic additive, batch, granulation.

  5. Contaminated fluid filtration plant using pneumatically renewable granulated material

    International Nuclear Information System (INIS)

    Lucas, J.-C.; Messirejean, Pierre.

    1980-01-01

    This invention concerns a plant for the filtration of a contaminated fluid flow using a granulated material capable of absorbing or adsorbing the contaminants. This plant includes a filtration box within which there is at least one appreciably vertical filtering bed filled with the material and crossed by the fluid flow, loading and discharge compartments respectively located at the top and bottom of the box, each in communication with the filtering bed and an air-actuated transfer system for loading and discharging this bed through these compartments. Facilities of this kind are used mainly in the nuclear and chemical engineering industries to rid their waste of radio-iodines, generally constituted by elementary iodine and methyl iodide, or of toxic gases that contaminate them. The granulated material, whose job it is to trap these contaminants by adsorption or absorption, is generally composed of active carbon or zeolites whose utilisation time is limited [fr

  6. Self-organizing of critical state in granulated superconductors

    International Nuclear Information System (INIS)

    Ginzburg, S.L.; Savitskaya, N.E.

    2000-01-01

    Critical state in granulated superconductors was studied on the basis of two mathematical models - the system of differential equations for calibration and invariant difference of phases and a simplified model describing the system of associated images and equivalent to the standard models to study self-organizing criticality. The critical state of granulated superconductors in all studied cases was shown to be self-organized. Besides, it is shown that the applied models are practically equivalent ones, that is they both show similar critical behavior and lead to coincidence of noncritical phenomena. For the first time one showed that the occurrence of self-organized critically within the system of nonlinear differential equations and its equivalence to self-organized critically in the standard models [ru

  7. Cultivation of aerobic granules for polyhydroxybutyrate production from wastewater.

    Science.gov (United States)

    Wang, Jin; Li, Wen-Wei; Yue, Zheng-Bo; Yu, Han-Qing

    2014-05-01

    Polyhydroxybutyrate (PHB)-rich aerobic granule was cultivated in a sequencing batch reactor (SBR) under nitrogen deficient conditions by adapting a two-step strategy. In the first step the PHB-storage ability of activated sludge was enhanced by keeping both oxygen and ammonia at a low level. In the second step granular sludge was cultivated through adjusting sludge settling time. The matured PHB-rich granular sludge with a PHB content of 40 ± 4.6% and a high settling ability was successfully obtained. The analysis on sludge surface properties showed that the surface charge, extracellular polymeric substances (EPS) content and the sludge hydrophobicity all increased significantly, while the surface energy of sludge decreased to a relatively steady state accompanied with the growth of granular sludge. This study demonstrates that the metabolism of intracellular storages induced microbial production of EPS, which favored the formation of aerobic granules. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Spray Drying Processing: granules production and drying kinetics of droplets

    International Nuclear Information System (INIS)

    Mondragon, R.; Julia, J. E.; Barba, A.; Jarque, J. C.

    2013-01-01

    Spray drying is a unit operation very common in many industrial processes. For each particular application, the resulting granulated material must possess determined properties that depend on the conditions in which the spray drying processing has been carried out, and whose dependence must be known in order to optimize the quality of the material obtained. The large number of variables that influence on the processes of matter and energy transfer and on the formation of granular material has required a detailed analysis of the drying process. Over the years there have been many studies on the spray drying processing of all kind of materials and the influence of process variables on the drying kinetics of the granulated material properties obtained. This article lists the most important works published for both the spray drying processing and the drying of individual droplets, as well as studies aimed at modeling the drying kinetics of drops. (Author)

  9. Multivariate modelling of the tablet manufacturing process with wet granulation for tablet optimization and in-process control

    NARCIS (Netherlands)

    Westerhuis, J.A; Coenegracht, P.M J; Lerk, C.F

    1997-01-01

    The process of tablet manufacturing with granulation is described as a two-step process. The first step comprises wet granulation of the powder mixture, and in the second step the granules are compressed into tablets. For the modelling of the pharmaceutical process of wet granulation and tableting,

  10. Behavioral experience induces zif268 expression in mature granule cells but suppresses its expression in immature granule cells

    Science.gov (United States)

    Huckleberry, Kylie A.; Kane, Gary A.; Mathis, Rita J.; Cook, Sarah G.; Clutton, Jonathan E.; Drew, Michael R.

    2015-01-01

    Thousands of neurons are born each day in the dentate gyrus (DG), but many of these cells die before reaching maturity. Both death and survival of adult-born neurons are regulated by neuronal activity in the DG. The immediate-early gene (IEG) zif268 appears to be an important mediator of these effects, as its expression can be induced by neural activity and knockout of zif268 impairs survival of adult-born neurons (Richardson et al., 1992; Veyrac et al., 2013). Despite the apparent importance of zif268 for adult neurogenesis, its behavior-induced expression has not been fully characterized in adult-born neurons. Here we characterize behavior-evoked expression of zif268 in mature and newborn dentate granule cells (DGCs). We first quantified zif268 expression in doublecortin-positive (DCX+) immature neurons and in the general granule cell population after brief exposure to a novel environment (NE). In the general granule cell population, zif268 expression peaked 1 h after NE exposure and returned to baseline by 8 h post-exposure. However, in the DCX+ cells, zif268 expression was suppressed relative to home cage for at least 8 h post-exposure. We next asked whether suppression of zif268 in DCX+ immature cells occurs in other behavioral paradigms that recruit the hippocampus. Exposure to Morris water maze (MWM) training, an enriched environment, or a NE caused approximately equal suppression of zif268 expression in DCX+ cells and approximately equal activation of zif268 expression among the general granule cell population. The same behavioral procedures activated zif268 expression in 6-week-old BrdU-labeled adult-born neurons, indicating that zif268 suppression is specific to immature neurons. Finally, we asked whether zif268 suppression varied as a function of age within the DCX+ population, which ranges in age from 0 to approximately 4 weeks. NE exposure had no significant effect on zif268 expression in 2- or 4-week-old BrdU-labeled neurons, but it significantly

  11. Soil Stabilisation Using Ground Granulated Blast Furnace Slag

    OpenAIRE

    Ashish Kumar Pathak; Dr. V. Pandey

    2014-01-01

    Stabilisation is a broad sense for the various methods employed and modifying the properties of a soil to improve its engineering performance and used for a variety of engineering works. In today‟s day soil stabilisation is the major problem for civil engineers, either for construction of road and also for increasing the strength or stability of soil and reduces the construction cost. In this thesis the soil are stabilised by ground granulated blast furnace slag (GGBS) and this material is ob...

  12. Lewis M. Rutherfurd and the First Photograph of Solar Granulation

    Science.gov (United States)

    Harvey, J. W.; Briggs, John W.; Prosser, Sian

    2017-08-01

    A major astronomical controversy of the mid-19th century was discordant descriptions of the small scale structure of the solar surface. Visual observers contradicted each other by describing the surface as consisting of “corrugations”, “willow leaves”, “rice grains”, “cumuli”, “thatch”, “granules”, etc. Early photographs of the solar surface were not good enough to settle the controversy. The French astronomer Jules Janssen is credited with the first 1876 photographs that clearly showed what we now call solar granulation (1876, CRAS 82, 1363). Upon seeing these images, New Yorker Lewis M. Rutherfurd (1878, MNRAS 38, 410) praised the high quality of Janssen’s images but asserted that he had also photographed granulation as early as 1871 using collodion wet plates. He sent copies of his best photograph to the Royal Astronomical Society to support his assertion. Curious about his claim, Briggs and Harvey set up Rutherfurd’s 13-inch achromatic refractor on Kitt Peak and found that it easily showed well-resolved solar granulation, so his claim might well have been justified. But without his plates we could not confirm the claim. For 140 years the copies of Rutherfurd’s best solar photograph remained in the archives of the Royal Astronomical Society and were recently discovered by Prosser (RAS Photographs A3/001B and A3/002). By coincidence a few days later, Briggs found the original August 11, 1871 plate. Despite poor condition these photographs show solar granulation. There are at least two other possible early claimants (Reade; Vogel) but their plates are almost certainly lost. Rutherfurd was a master of astronomical instrumentation and photography. He was reticent about his work, letting results speak for themselves, so it is satisfying to find that he was justified in making his claim of priority.

  13. Convergent evolution of germ granule nucleators: A hypothesis.

    Science.gov (United States)

    Kulkarni, Arpita; Extavour, Cassandra G

    2017-10-01

    Germ cells have been considered "the ultimate stem cell" because they alone, during normal development of sexually reproducing organisms, are able to give rise to all organismal cell types. Morphological descriptions of a specialized cytoplasm termed 'germ plasm' and associated electron dense ribonucleoprotein (RNP) structures called 'germ granules' within germ cells date back as early as the 1800s. Both germ plasm and germ granules are implicated in germ line specification across metazoans. However, at a molecular level, little is currently understood about the molecular mechanisms that assemble these entities in germ cells. The discovery that in some animals, the gene products of a small number of lineage-specific genes initiate the assembly (also termed nucleation) of germ granules and/or germ plasm is the first step towards facilitating a better understanding of these complex biological processes. Here, we draw on research spanning over 100years that supports the hypothesis that these nucleator genes may have evolved convergently, allowing them to perform analogous roles across animal lineages. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  14. Performance of Lightweight Concrete based on Granulated Foamglass

    Science.gov (United States)

    Popov, M.; Zakrevskaya, L.; Vaganov, V.; Hempel, S.; Mechtcherine, V.

    2015-11-01

    The paper presents an investigation of lightweight concretes properties, based on granulated foamglass (GFG-LWC) aggregates. The application of granulated foamglass (GFG) in concrete might significantly reduce the volume of waste glass and enhance the recycling industry in order to improve environmental performance. The conducted experiments showed high strength and thermal properties for GFG-LWC. However, the use of GFG in concrete is associated with the risk of harmful alkali-silica reactions (ASR). Thus, one of the main aims was to study ASR manifestation in GFG-LWC. It was found that the lightweight concrete based on porous aggregates, and ordinary concrete, have different a mechanism of ASR. In GFG-LWC, microstructural changes, partial destruction of granules, and accumulation of silica hydro-gel in pores were observed. According to the existing methods of analysis of ASR manifestation in concrete, sample expansion was measured, however, this method was found to be not appropriate to indicate ASR in concrete with porous aggregates. Microstructural analysis and testing of the concrete strength are needed to evaluate the damage degree due to ASR. Low-alkali cement and various pozzolanic additives as preventive measures against ASR were chosen. The final composition of the GFG-LWC provides very good characteristics with respect to compressive strength, thermal conductivity and durability. On the whole, the potential for GFG-LWC has been identified.

  15. ROTATION AND GRANULATION OF THE K2 GIANT α SER

    Energy Technology Data Exchange (ETDEWEB)

    Gray, David F., E-mail: dfgray@uwo.ca [Department of Physics and Astronomy University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 3K7 (Canada)

    2016-07-20

    The red giant α Ser was observed over 10 seasons, 2001–2010, at the Elginfield Observatory with the high-resolution coudé spectrograph. Season-mean radial velocities appear to show a small secular rise ∼11 ± 3 m s{sup 1} yr{sup 1}. The absolute spectroscopic radial velocity with convective blueshifts taken into account is 2730 m s{sup 1}. Ten line-depth ratios were investigated and show that the star's temperature is constant with any secular variation below 1.3 ± 1.0 K over the 11 years of observation. Fourier analysis of the line broadening yields v sin i = 2.0 ± 0.3 km s{sup 1} and a radial-tangential macroturbulence dispersion ζ {sub RT} = 4.50 ± 0.10 km s{sup 1}. The third-granulation-signature plot shows that the granulation velocities of α Ser are only 0.55 ± 0.10 as large as the Sun's. The line bisector of Fe i λ 6253 has the usual “C” shape and when mapped onto the third-signature plot results in a flux deficit that is slightly broader than seen in other measured K giants. The deficit fractional area of 12.3 ± 1.5% suggests a temperature difference between granules and lanes of 105 K as seen averaged over the stellar disk.

  16. First results on quiet and magnetic granulation from SOUP

    Science.gov (United States)

    Title, A. M.; Tarbell, T. D.; Acton, L.; Duncan, D.; Ferguson, S. H.; Finch, M.; Frank, Z.; Kelly, G.; Lindgren, R.; Morrill, M.

    1987-01-01

    The flight of Solar Optical Universal Polarimeter (SOUP) on Spacelab 2 allowed the collection of time sequences of diffraction limited (0.5 arc sec) granulation images with excellent pointing (0.003 arc sec) and completely free of the distortion that plagues groundbased images. The p-mode oscillations are clearly seen in the data. Using Fourier transforms in the temporal and spatial domain, it was shown that the p-modes dominate the autocorrelation lifetime in magnetic regions. When these oscillations are removed the autocorrelation lifetime is found to be 500 sec in quiet and 950 sec in magnetic regions. In quiet areas exploding granules are seen to be common. It is speculated that a significant fraction of granule lifetimes are terminated by nearby explosions. Using local correlation tracking techniques it was able to measure horizontal displacements, and thus transverse velocities, in the magnetic field. In quiet sun it is possible to detect both super and mesogranulation. Horizontal velocities are as great as 1000 m/s and the average velocity is 400 m/s. In magnetic regions horizontal velocities are much less, about 100 m/s.

  17. Experimental determination of residence time distribution in continuous dry granulation.

    Science.gov (United States)

    Mangal, Haress; Kleinebudde, Peter

    2017-05-30

    With increasing importance of continuous manufacturing, the interest in integrating dry granulation into a continuous manufacturing line is growing. Residence time distribution measurements are of importance as they provide information about duration of materials within the process. These data enable traceability and are highly beneficial for developing control strategies. A digital image analysis system was used to determine the residence time distribution of two materials with different deformation behavior (brittle, plastic) in the milling unit of dry granulation systems. A colorant was added to the material (20%w/w iron oxide), which did not affect the material properties excessively, so the milling process could be mimicked well. Experimental designs were conducted to figure out which parameters effect the mean residence time strongly. Moreover, two types of dry granulation systems were contrasted. Longer mean residence times were obtained for the oscillating mill (OM) compared to the conical mill (CM). For co-processed microcrystalline cellulose residence times of 19.8-44.4s (OM) and 11.6-29.1s (CM) were measured, mainly influenced by the specific compaction force, the mill speed and roll speed. For dibasic calcium phosphate anhydrate residence times from 17.7-46.4 (OM) and 5.4-10.2s (CM) were measured, while here the specific compaction force, the mill speed and their interactions with the roll speed had an influence on the mean residence time. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Studies on the influence of laser beams on wound granulation

    International Nuclear Information System (INIS)

    Brunner, R.

    1982-01-01

    The influence of laser light of law energy on wound healing was tested on 204 rats in a blind study. The growth of granulation tissue in a polyvinylchloride cylinder implanted on the backs of the animals served as parameter for wound healing. Irradiation was carried out with a helium-neon laser (wavelength 632.8 nm) at daily doses of 0.5 J/cm 2 , 1.5 J/cm 2 , 4 J/cm 2 , 10 J/cm 2 and 20 J/cm 2 , and with incoherent non-linear polarized red light (wavelength 630 nm) with a daily dose of 4 J/cm 2 . This was repeated 8 times. Laser irradiation caused a statistically significant increase in wet and dry granulation tissue weight of 25% in the dose range 1.5 J/cm 2 to 20 J/cm 2 . At 0.5 J/cm 2 the effect was less, but the least effect was achieved by non-linear polarized incoherent red light. Bacteriological evaluation of wound germ counts revealed a marginally lower presence of high germ cell densities. In irradiated animals, histological and enzyme cytochemical findings revealed, in addition to a significant findings revealed, in addition to a significant increase in mast cells, a smaller increase in fibroblast count and a slight decrease in granulocytic and histiocytic elements. The biochemical evaluation of granulation tissue revealed no differences in collagen content between irradiated and unirradiated animals. (orig.) [de

  19. Quantification of heterotypic granule fusion in human neutrophils by imaging flow cytometry

    Directory of Open Access Journals (Sweden)

    Halla Björnsdottir

    2016-03-01

    Full Text Available Human neutrophils are filled with intracellular storage organelles, called granules and secretory vesicles, which differ in their content of soluble matrix proteins and membrane-bound molecules. To date, at least four distinct granule/vesicle subsets have been identified. These organelles may secrete their content extracellularly following mobilization to and fusion with the plasma membrane, but some of them may also fuse with internal membrane-enclosed organelles, typically a plasma membrane-derived phagosome. There are also instances where different granules appear to fuse with one another, a process that would enable mixing of their matrix and membrane components. Such granule fusion enables e.g., myeloperoxidase-processing of intragranular oxygen radicals, a key event in the formation of neutrophil extracellular traps (Björnsdottir et al., 2015 [1]. Described herein are data that show the quantification of such heterotypic granule–granule fusion by the use of imaging flow cytometry, a technique that combines flow cytometry with microscopy. The analysis described is based on immunofluorescent staining of established granule markers (lactoferrin and/or NGAL for one granule subset; the specific granules, and CD63 for another granule subset, the azurophil granules and calculation of a colocalization score for resting and PMA-stimulated neutrophils.

  20. Fluidized Bed Hot Melt Granulation with Hydrophilic Materials Improves Enalapril Maleate Stability.

    Science.gov (United States)

    Guimarães, Thiago F; Comelli, Amanda C C; Tacón, Luciana A; Cunha, Talita A; Marreto, Ricardo N; Freitas, Luís A P

    2017-05-01

    This work aimed at developing enalapril maleate granules in order to improve its stability in solid dosage form. Granules were prepared by hot melt granulation using a fluidized bed apparatus. Gelucire 50/13®, polyethylene glycol 6000 e Poloxamer 407® were studied and compared as binders in 2 × 2 factorial designs where the proportions of enalapril maleate, binders and spray dried lactose were varied. The granulation process resulted in high yields and granule sizes that indicated the prevalence of particles coating. Furthermore, the granules obtained showed adequate flowability and a fast dissolution rate of enalapril maleate with almost 100% of the drug released in 10 min. The stability of enalapril maleate in hard gelatin capsules showed that the drug stability was greatly increased in granules, since for raw drug, the remaining content of enalapril maleate after 91 days was 68.4% and, for granules, the content was always above 93%. This result was confirmed by the quantification of the degradation products, enalaprilat and diketopiperazine, which were found in very low content in granules samples. The results demonstrate that fluidized bed hot melt granulation with hydrophilic binders is a suitable alternative for improving the chemical stability of enalapril maleate.

  1. Formation of tRNA granules in the nucleus of heat-induced human cells

    International Nuclear Information System (INIS)

    Miyagawa, Ryu; Mizuno, Rie; Watanabe, Kazunori; Ijiri, Kenichi

    2012-01-01

    Highlights: ► tRNAs are tranlocated into the nucleus in heat-induced HeLa cells. ► tRNAs form the unique granules in the nucleus. ► tRNA ganules overlap with nuclear stress granules. -- Abstract: The stress response, which can trigger various physiological phenomena, is important for living organisms. For instance, a number of stress-induced granules such as P-body and stress granule have been identified. These granules are formed in the cytoplasm under stress conditions and are associated with translational inhibition and mRNA decay. In the nucleus, there is a focus named nuclear stress body (nSB) that distinguishes these structures from cytoplasmic stress granules. Many splicing factors and long non-coding RNA species localize in nSBs as a result of stress. Indeed, tRNAs respond to several kinds of stress such as heat, oxidation or starvation. Although nuclear accumulation of tRNAs occurs in starved Saccharomyces cerevisiae, this phenomenon is not found in mammalian cells. We observed that initiator tRNA Met (Meti) is actively translocated into the nucleus of human cells under heat stress. During this study, we identified unique granules of Meti that overlapped with nSBs. Similarly, elongator tRNA Met was translocated into the nucleus and formed granules during heat stress. Formation of tRNA granules is closely related to the translocation ratio. Then, all tRNAs may form the specific granules.

  2. Rice starch granule amylolysis--differentiating effects of particle size, morphology, thermal properties and crystalline polymorph.

    Science.gov (United States)

    Dhital, Sushil; Butardo, Vito M; Jobling, Stephen A; Gidley, Michael J

    2015-01-22

    The underlying mechanism of amylolysis of rice starch granules was investigated using isolated starch granules from wild-type, as well as SBEIIb mutant and down-regulated lines. Fused granule agglomerates isolated from mutant and transgenic lines were hydrolysed at similar rates by amylases, and had similar crystalline patterns and thermal properties as individual granules. Surface pores, a feature previously only reported for A-polymorphic starch granules, were also observed in B- and C-polymorphic rice starch granules. Although the microscopic patterns of hydrolysis among granules with different crystalline polymorphs were qualitatively similar, the extent and the rate of amylolysis were different, suggesting that B-type crystalline polymorphs are intrinsically more resistant to enzymatic hydrolysis than A-type in rice starch granules. It is proposed that the slightly longer branch lengths of amylopectin which leads to the formation of more stable B-type double helical structures compared to their A-type counterparts is the major parameter, with other factors such as granule size, surface pores and interior channels having secondary roles, in determining the rate of enzymatic hydrolysis of rice starch granules. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Proteome Profile of Starch Granules Purified from Rice (Oryza sativa) Endosperm.

    Science.gov (United States)

    Xing, Shihai; Meng, Xiaoxi; Zhou, Lihui; Mujahid, Hana; Zhao, Chunfang; Zhang, Yadong; Wang, Cailin; Peng, Zhaohua

    2016-01-01

    Starch is the most important food energy source in cereals. Many of the known enzymes involved in starch biosynthesis are partially or entirely granule-associated in the endosperm. Studying the proteome of rice starch granules is critical for us to further understand the mechanisms underlying starch biosynthesis and packaging of starch granules in rice amyloplasts, consequently for the improvement of rice grain quality. In this article, we developed a protocol to purify starch granules from mature rice endosperm and verified the quality of purified starch granules by microscopy observations, I2 staining, and Western blot analyses. In addition, we found the phenol extraction method was superior to Tris-HCl buffer extraction method with respect to the efficiency in recovery of starch granule associated proteins. LC-MS/MS analysis showed identification of already known starch granule associated proteins with high confidence. Several proteins reported to be involved in starch synthesis in prior genetic studies in plants were also shown to be enriched with starch granules, either directly or indirectly, in our studies. In addition, our results suggested that a few additional candidate proteins may also be involved in starch synthesis. Furthermore, our results indicated that some starch synthesis pathway proteins are subject to protein acetylation modification. GO analysis and KEGG pathway enrichment analysis showed that the identified proteins were mainly located in plastids and involved in carbohydrate metabolism. This study substantially advances the understanding of the starch granule associated proteome in rice and post translational regulation of some starch granule associated proteins.

  4. Isolation and studies of the granules of the amebocytes of Limulus polyphemus, the horseshoe crab.

    Science.gov (United States)

    Mürer, E H; Levin, J; Holme, R

    1975-12-01

    Granules were isolated from the cytoplasm of the amebocytes of Limulus polyphemus, the horseshoe crab, by disruption of cells obtained from blood which had been drawn into 2 mM propranolol. The granules subsequently were purified by centrifugation through a sucrose gradient that contained heparin. Extracts of the granules were prepared by freezing and thawing the granule preparations in distilled water. Transmission and scanning electron microscopy of the granules revealed round or ovoid particles. However, only one type of granule appeared to be present. The ultraviolet spectrum of the extract of amebocyte granules demonstrated a peak at 277 nm at pH 7.4, and a shift into two peaks of 281 nm and 290 nm at alkaline pH. Analytical ultracentrifugation revealed a pattern similar to that observed with lysates prepared from intact amebocytes. Polyacrylamide gel electrophoresis, in the presence of urea at pH 4.5, demonstrated patterns similar to those observed with amebocyte lysate. Extracts of the granules were gelled by bacterial endotoxin. The blood of the horseshoe crab contains only one type of cell, the amebocyte. Previous studies have shown that the blood coagulation mechanism of Limulus is contained entirely within amebocytes. The current studies suggest that the granules, which pack the cytoplasm of these cells, contain all of the factors required for the coagulation of blood, including the clottable protein. The intracellularly localized coagulation system is released from amebocytes when their granules rupture during cell aggregation.

  5. The acceleration of sludge granulation using the chlamydospores of Phanerochaete sp. HSD

    International Nuclear Information System (INIS)

    Hailei, Wang; Li, Li; Ping, Li; Hui, Li; Guosheng, Liu; Jianming, Yao

    2011-01-01

    Highlights: → Seeding the chlamydospores of Phanerochaete sp. HSD to SBR can accelerate sludge granulation. → We reveal the annual ring-like multilayer structure of aerobic granule. → We propose the mechanism of accelerated sludge granulation. → Accelerated granular sludge reactor has better removal performance toward phenol wastewater. - Abstract: In the present paper, a novel method to accelerate sludge granulation is presented. Inoculation with chlamydospores of Phanerochaete sp. HSD accelerated sludge granulation during the treatment process of phenol wastewater, and the sludge granulation rate reached 66 ± 2% on day 7, 32 days earlier than that of the control inoculated with activated sludge only. Aerobic granule in R1 (AG R1 ) showed an annual ring-like multilayer structure and a primary core also existed in the nuclear area of the granule. The mechanism of rapid granulation revealed that the chlamydospore could survive in phenol wastewater and form the primary matrix on which aerobic granule was developed layer by layer. In addition, AG R1 developed in a phenol uptake system to counteract the adverse effects of phenol inhibition. Higher tolerance toward wastewater with high phenol strength was exhibited, and the maximum specific phenol degradation rate reached 1.54 g phenol g -1 VSS day -1 .

  6. Quantitative Assessment of Mass Flow Boundaries in Continuous Twin-screw Granulation.

    Science.gov (United States)

    Schmidt, Adrian; de Waard, Hans; Moll, Klaus-Peter; Krumme, Markus; Kleinebudde, Peter

    In pharmaceutical manufacturing, there is an increasing interest in continuous manufacturing. As an example for fast continuous processes in general of considerable complexity, this study was focussed on improving the understanding of twin-screw wet granulation. The impact of the liquid-to-solid (L/S) mass flow ratio on product quality (granules) as well as on downstream process operations (tableting) was investigated in detail. Initially two methods were used to define L/S ratio boundaries for the granulation regime in twin-screw wet granulation. It was shown that the first method, which is based on measuring the wet granule mass flow variation, can be used to define the upper L/S ratio boundary of the granulation regime. The second method, based on measuring the granule size distribution, can be used to define the lower L/S ratio boundary of the regime. Using these methods, the granulation regime for different formulations could be established. This information was then used to show that the formulation could be optimised such that the process is more robust (i.e. wider L/S ratio boundaries for the granulation regime). Also it could be used to optimise the formulation considering further downstream processing such as drying (using as little water as possible to reduce drying efforts) or tableting (obtain granules with optimised tableting properties). Preferably, the process should be performed close to the lower L/S ratio boundary of the granulation regime. In summary, these tools enabled the quantitative establishment of granulation regime boundaries in a twin-screw wet granulation process and can be used to optimise formulation and to create a robust process. Analogies to other continuous processes in completely different applications can be conceived.

  7. How Does Poly(hydroxyalkanoate) Affect Methane Production from the Anaerobic Digestion of Waste-Activated Sludge?

    Science.gov (United States)

    Wang, Dongbo; Zhao, Jianwei; Zeng, Guangming; Chen, Yinguang; Bond, Philip L; Li, Xiaoming

    2015-10-20

    Recent studies demonstrate that, besides being used for production of biodegradable plastics, poly(hydroxyalkanoate) (PHA) that is accumulated in heterotrophic microorganisms during wastewater treatment has another novel application direction, i.e., being utilized for enhancing methane yield during the anaerobic digestion of waste-activated sludge (WAS). To date, however, the underlying mechanism of how PHA affects methane production remains largely unknown, and this limits optimization and application of the strategy. This study therefore aims to fill this knowledge gap. Experimental results showed that with the increase of sludge PHA levels from 21 to 184 mg/g of volatile suspended solids (VSS) the methane yield linearly increased from 168.0 to 246.1 mL/g of VSS (R(2) = 0.9834). Compared with protein and carbohydrate (the main components of a cell), PHA exhibited a higher biochemical methane potential on a unit VSS basis. It was also found that the increased PHA not only enhanced cell disruption of PHA cells but also benefited the soluble protein conversion of both PHA- and non-PHA cells. Moreover, the reactor fed with higher PHA sludge showed greater sludge hydrolysis and acidification than those fed with the lower PHA sludges. Further investigations using fluorescence in situ hybridization and enzyme analysis revealed that the increased PHA enhanced the abundance of methanogenic Archaea and increased the activities of protease, acetate kinase, and coenzyme F420, which were consistent with the observed methane yield. This work provides insights into PHA-involved WAS digestion systems and may have important implications for future operation of wastewater treatment plants.

  8. The effect of polyphosphate kinase gene deletion on polyhydroxyalkanoate accumulation and carbon metabolism in Pseudomonas putida KT2440.

    Science.gov (United States)

    Casey, William T; Nikodinovic-Runic, Jasmina; Fonseca Garcia, Pilar; Guzik, Maciej W; McGrath, John W; Quinn, John P; Cagney, Gerard; Prieto, Maria Auxiliadora; O'Connor, Kevin E

    2013-10-01

    The primary enzyme involved in polyphosphate (polyP) synthesis, polyP kinase (ppk), has been deleted in Pseudomonas putida KT2440. This has resulted in a threefold to sixfold reduction in polyhydroxyalkanoate (PHA) accumulation compared with the wild type under conditions of nitrogen limitation, with either temperature or oxidative (H2O2) stress, when grown on glucose. The accumulation of PHA by Δppk mutant was the same as the wild type under nitrogen-limiting growth conditions. There was no difference in polyP levels between wild-type and Δppk strains under all growth conditions tested. In the Δppk mutant proteome, polyP kinase (PPK) was undetectable, but up-regulation of the polyp-associated proteins polyP adenosine triphosphate (ATP)/nicotinamide adenine dinucleotide (NAD) kinase (PpnK), a putative polyP adenosine monophosphate (AMP) phosphotransferase (PP_1752), and exopolyphosphatase was observed. Δppk strain exhibited significantly retarded growth with glycerol as carbon and energy source (42 h of lag period compared with 24 h in wild-type strain) but similar growth to the wild-type strain with glucose. Analysis of gene transcription revealed downregulation of glycerol kinase and the glycerol facilitator respectively. Glycerol kinase protein expression was also downregulated in the Δppk mutant. The deletion of ppk did not affect motility but reduced biofilm formation. Thus, the knockout of the ppk gene has resulted in a number of phenotypic changes to the mutant without affecting polyP accumulation. © 2013 John Wiley & Sons Ltd and Society for Applied Microbiology.

  9. Structure reveals regulatory mechanisms of a MaoC-like hydratase from Phytophthora capsici involved in biosynthesis of polyhydroxyalkanoates (PHAs.

    Directory of Open Access Journals (Sweden)

    Huizheng Wang

    Full Text Available Polyhydroxyalkanoates (PHAs have attracted increasing attention as "green plastic" due to their biodegradable, biocompatible, thermoplastic, and mechanical properties, and considerable research has been undertaken to develop low cost/high efficiency processes for the production of PHAs. MaoC-like hydratase (MaoC, which belongs to (R-hydratase involved in linking the β-oxidation and the PHA biosynthetic pathways, has been identified recently. Understanding the regulatory mechanisms of (R-hydratase catalysis is critical for efficient production of PHAs that promise synthesis an environment-friendly plastic.We have determined the crystal structure of a new MaoC recognized from Phytophthora capsici. The crystal structure of the enzyme was solved at 2.00 Å resolution. The structure shows that MaoC has a canonical (R-hydratase fold with an N-domain and a C-domain. Supporting its dimerization observed in structure, MaoC forms a stable homodimer in solution. Mutations that disrupt the dimeric MaoC result in a complete loss of activity toward crotonyl-CoA, indicating that dimerization is required for the enzymatic activity of MaoC. Importantly, structure comparison reveals that a loop unique to MaoC interacts with an α-helix that harbors the catalytic residues of MaoC. Deletion of the loop enhances the enzymatic activity of MaoC, suggesting its inhibitory role in regulating the activity of MaoC.The data in our study reveal the regulatory mechanism of an (R-hydratase, providing information on enzyme engineering to produce low cost PHAs.

  10. An integrative study on biologically recovered polyhydroxyalkanoates (PHAs) and simultaneous assessment of gut microbiome in yellow mealworm.

    Science.gov (United States)

    Ong, Su Yean; Kho, Hui-Pheng; Riedel, Sebastian L; Kim, Seok-Won; Gan, Chee-Yuen; Taylor, Todd D; Sudesh, Kumar

    2018-01-10

    Polyhydroxyalkanoates (PHAs) are produced in microbes as a source of carbon and energy storage. They are biodegradable and have properties similar to synthetic plastics, which make them an interesting alternative to petroleum-based plastics. In this study, a refined method of recovering PHA from Cupriavidus necator biomass was proposed by incorporating the use of the yellow mealworm (the larval phase of the mealworm beetle, Tenebrio molitor) as partial purification machinery, followed by washing of the fecal pellets with distilled water and sodium hydroxide. The PHA contents of the cells used in this study were 55wt% (produced from palm olein) and 60 wt% (produced from waste animal fats). The treatment of distilled water and NaOH further increased the purity of PHA to 94%. In parallel, analysis of the 16S rRNA metagenomic sequencing of the mealworm gut microbiome has revealed remarkable changes in the bacterial diversity, especially between the mealworms fed with cells produced from palm olein and waste animal fats. This biological recovery of PHA from cells is an attempt to move towards a green and sustainable process with the aim of reducing the use of harmful solvents and strong chemicals during polymer purification. The results obtained show that - purities of >90%, without a reduction in the molecular weight, can be obtained through this integrative biological recovery approach. In addition, this study has successfully shown that the cells, regardless of their origins, were readily consumed by the mealworms, and there is a correlation between the feed type and the mealworm gut microbiome. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Microbial Community Composition of Polyhydroxyalkanoate-Accumulating Organisms in Full-Scale Wastewater Treatment Plants Operated in Fully Aerobic Mode

    Science.gov (United States)

    Oshiki, Mamoru; Onuki, Motoharu; Satoh, Hiroyasu; Mino, Takashi

    2013-01-01

    The removal of biodegradable organic matter is one of the most important objectives in biological wastewater treatments. Polyhydroxyalkanoate (PHA)-accumulating organisms (PHAAOs) significantly contribute to the removal of biodegradable organic matter; however, their microbial community composition is mostly unknown. In the present study, the microbial community composition of PHAAOs was investigated at 8 full-scale wastewater treatment plants (WWTPs), operated in fully aerobic mode, by fluorescence in situ hybridization (FISH) analysis and post-FISH Nile blue A (NBA) staining techniques. Our results demonstrated that 1) PHAAOs were in the range of 11–18% in the total number of cells, and 2) the microbial community composition of PHAAOs was similar at the bacterial domain/phylum/class/order level among the 8 full-scale WWTPs, and dominant PHAAOs were members of the class Alphaproteobacteria and Betaproteobacteria. The microbial community composition of α- and β-proteobacterial PHAAOs was examined by 16S rRNA gene clone library analysis and further by applying a set of newly designed oligonucleotide probes targeting 16S rRNA gene sequences of α- or β-proteobacterial PHAAOs. The results demonstrated that the microbial community composition of PHAAOs differed in the class Alphaproteobacteria and Betaproteobacteria, which possibly resulted in a different PHA accumulation capacity among the WWTPs (8.5–38.2 mg-C g-VSS−1 h−1). The present study extended the knowledge of the microbial diversity of PHAAOs in full-scale WWTPs operated in fully aerobic mode. PMID:23257912

  12. Downstream processing from melt granulation towards tablets: In-depth analysis of a continuous twin-screw melt granulation process using polymeric binders.

    Science.gov (United States)

    Grymonpré, W; Verstraete, G; Vanhoorne, V; Remon, J P; De Beer, T; Vervaet, C

    2018-03-01

    The concept of twin-screw melt granulation (TSMG) has steadily (re)-gained interest in pharmaceutical formulation development as an intermediate step during tablet manufacturing. However, to be considered as a viable processing option for solid oral dosage forms there is a need to understand all critical sources of variability which could affect this granulation technique. The purpose of this study was to provide an in-depth analysis of the continuous TSMG process in order to expose the critical process parameters (CPP) and elucidate the impact of process and formulation parameters on the critical quality attributes (CQA) of granules and tablets during continuous TSMG. A first part of the study dealt with the screening of various amorphous polymers as binder for producing high-dosed melt granules of two model drug (i.e. acetaminophen and hydrochlorothiazide). The second part of this study described a quality-by-design (QbD) approach for melt granulation of hydrochlorothiazide in order to thoroughly evaluate TSMG, milling and tableting stage of the continuous TSMG line. Using amorphous polymeric binders resulted in melt granules with high milling efficiency due to their brittle behaviour without producing excessive amounts of fines, providing high granule yields with low friability. Therefore, it makes them extremely suitable for further downstream processing. One of the most important CPP during TSMG with polymeric binders was the granulation-torque, which - in case of polymers with high T g - increased during longer granulation runs to critical levels endangering the continuous process flow. However, by optimizing both screw speed and throughput or changing to polymeric binders with lower T g it was possible to significantly reduce this risk. This research paper highlighted that TSMG must be considered as a viable option during formulation development of solid oral dosage forms based on the robustness of the CQA of both melt granules and tablets. Copyright © 2017

  13. Effects of hydraulic retention time on aerobic granulation and granule growth kinetics at steady state with a fast start-up strategy.

    Science.gov (United States)

    Liu, Yong-Qiang; Zhang, Xing; Zhang, Rui; Liu, Wen-Tso; Tay, Joo-Hwa

    2016-01-01

    A hydraulic retention time (HRT) of 4, 6, and 8 h was employed, respectively, in three reactors to study the effects of HRT on granulation with a newly developed fast granulation strategy, i.e., a strategy by combining strong hydraulic selection pressure with high organic loading rate (OLR). Granules with clear boundary appeared within 24 h after reactor start-up and all reactors reached a pseudo steady state after 6-day operation. A 4-h HRT resulted in a relatively higher increasing rate in terms of granule size during granule development period, i.e., 208 μm day(-1), and the bigger granule size and the higher sludge volume index at the pseudo steady state. For HRT of 6 or 8 h, no obvious difference was observed. However, it was found that HRT influenced sludge retention time (SRT) and kinetics significantly. A HRT changing from 4 to 8 h led to an increased SRT from 3 to 21 days, a decreased observed specific biomass growth rate (μ obs) and an decreased observed biomass yield (Y obs) of stable granules from 0.37 to 0.062 days(-1), and 0.177 to 0.055 g MLVSS g(-1) COD, respectively. Both μ obs and Y obs had a linear relationship with the reciprocal of HRT. In addition, the great difference of microbial community between seed sludge, sludge retained in the reactors, and sludge washed out indicated a strong microbial selection for fast granulation within 24 h. However, during the granule development period from day 1 to 6, no more microbial selection was observed except an adjustment of microbial community. Little influence of HRT on microbial population in granular sludge indicated a minor role of HRT played for granulation with the fast start-up strategy adopted in this study. The results demonstrated that hydraulic selection pressure for granulation was mainly from short settling time, which led to strong microbial selection during the granulation period. Meanwhile, although HRT did not affect granulation with the fast start-up strategy, it played an

  14. Using deepest regression method for optimization of fluidized bed granulation on semi-full scale.

    Science.gov (United States)

    Rambali, B; Van Aelst, S; Baert, L; Massart, D L

    2003-06-04

    This study applied the deepest regression method to estimate the granule size of unsuccessful fluidized bed granulation runs. This study uses data from a previous study [Int. J. Pharm. 220 (2001) 149] on optimization of fluidized granulation process, wherein 8 of the 30 runs did not succeeded due to overwetting of the powder bed. The "complete data" (the observed and the estimated granule size by the depth regression method) were used to develop two regression models for the granule size: an empirical model based on the process variables (inlet air temperature, inlet airflow rate, spray rate, and inlet air humidity) and a fundamental model based on the powder bed moisture content and the relative droplet size. The regression models based on the incomplete data from the previous study and the regression models of the "complete data" were comparable in the sense that the contour plots based on the respective models and the predicted granule size were comparable.

  15. Penicillium species as a rare isolate in tracheal granulation tissue: a case series

    Science.gov (United States)

    Randhawa, Premjit S; Nouraei, SA Reza; Howard, David J; Sandhu, Gurpreet S; Petrou, Michael A

    2008-01-01

    Introduction Granulation tissue formation is a major problem complicating the treatment of upper airway stenosis. We present two cases of recurrent tracheal granulation tissue colonisation by Penicillium species in patients undergoing laryngotracheal reconstructive surgery for post-intubation tracheal stenosis. We believe that although most Penicillium species do not cause invasive disease they can be a contributory factor to the occurrence of upper airway stenosis. Case presentation A microbiological and mycological study of tracheal granulation tissue in two patients with recurrent laryngotracheal stenosis was carried out. Penicillium species was seen microscopically and cultured from tracheal granulation tissue. Neither patient grew any bacteria known to be associated with airway granulation tissue formation. Amphotericin B, itraconazole, flucytosine voriconazole and caspofungin were highly active against both isolates. Conclusion A search for a fungal cause should form part of the investigation for recurrent tracheal granulation tissue during laryngotracheal reconstruction. PMID:18346276

  16. High level waste containing granules coated and embedded in metal as an alternative to HLW glasses

    International Nuclear Information System (INIS)

    Neumann, W.

    1980-01-01

    Simulated high level waste containing granules were overcoated with pyrocarbon or nickel respectively. The coatings were performed by the use of chemical vapour deposition in a fluidized bed. The coated granules were embedded in an aluminium-silicon-alloy to improve the dissipation of radiation induced heat. The metal-granules-composites obtained were of improved product stability related to the high level waste containing glasses. (orig.) [de

  17. Melt granulation in fluidized bed: a comparative study of spray-on versus in situ procedure.

    Science.gov (United States)

    Mašić, Ivana; Ilić, Ilija; Dreu, Rok; Ibrić, Svetlana; Parojčić, Jelena; Srčič, Stanko

    2014-01-01

    The aim of this study was to investigate the influence of process parameters, binder content and binder addition method on characteristics of the granules obtained by melt granulation (MG) in fluidized bed. Spray-on experiments were performed according to 2(3) full factorial design. The effect of binder content, molten binder feed rate, and spray air pressure on granule size and size distribution, granule shape, flowability and drug release rate was investigated. In the in situ experiments, the influence of binder particle size and binder content was evaluated. Solid-state characterization was performed by means of differential scanning calorimetry, X-ray powder diffraction and Fourier transform infrared spectroscopy. Size of the granules obtained by spray-on procedure was significantly influenced by binder content and spray air pressure, while the width of particle size distribution was mainly affected by binder feed rate. Spray air pressure showed the most significant influence on granule shape. It was shown that smooth and spherical particles with good flow properties may be obtained by both procedures, spray-on and in situ MG. The results obtained indicated the influence of agglomeration mechanism on granule sphericity, with higher degree of granule sphericity observed when immersion and layering was the dominant mechanism. Paracetamol release from granulates was very rapid, but after compression of the granules into tablets, drug release was considerably slower. Solid-state analysis confirmed that the physical form of the granulate components remained unaffected after the MG process. The results presented indicate that MG in fluidized bed could be a good alternative to conventional granulation techniques.

  18. Pseudo chediak-higashi granules in acute lymphoblastic leukemia: a rare entity.

    Science.gov (United States)

    Agrawal, Pallavi; Kumar, Narender; Sharma, Prashant; Varma, Subhash; Varma, Neelam

    2014-09-01

    Pseudo-Chediak-Highashi granules are giant cytoplasmic inclusions commonly encountered in myeloblasts or other myeloid precursors in acute myeloid leukemia and myelodysplastic syndromes. They derive their name from the inherited Chediak-Higashi syndrome that presents with oculocutaneous albinism, chronic infections and platelet dense granule deficiency. We report possibly the third case in world literature where these granules were seen in the blast cells of acute lymphoblastic leukemia in a 15-year-old male.

  19. Continuous twin screw granulation of controlled release formulations with various HPMC grades.

    Science.gov (United States)

    Vanhoorne, V; Janssens, L; Vercruysse, J; De Beer, T; Remon, J P; Vervaet, C

    2016-09-25

    HPMC is a popular matrix former to formulate tablets with extended drug release. Tablets with HPMC are preferentially produced by direct compression. However, granulation is often required prior to tableting to overcome poor flowability of the formulation. While continuous twin screw granulation has been extensively evaluated for granulation of immediate release formulations, twin screw granulation of controlled release formulations including the dissolution behavior of the formulations received little attention. Therefore, the influence of the HPMC grade (viscosity and substitution degree) and the particle size of theophylline on critical quality attributes of granules (continuously produced via twin screw granulation) and tablets was investigated in the current study. Formulations with 20 or 40% HPMC, 20% theophylline and lactose were granulated with water at fixed process parameters via twin screw granulation. The torque was influenced by the viscosity and substitution degree of HPMC, but was not a limiting factor for the granulation process. An optimal L/S ratio was selected for each formulation based on the granule size distribution. The granule size distributions were influenced by the substitution degree and concentration of HPMC and the particle size of theophylline. Raman and UV spectroscopic analysis on 8 sieve fractions of granules indicated an inhomogeneous distribution of theophylline over the size fractions. However, this phenomenon was not correlated with the hydration rate or viscosity of HPMC. Controlled release of theophylline could be obtained over 24h with release profiles close to zero-order. The release of theophylline could be tailored via selection of the substitution degree and viscosity of HPMC. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Comparison of A and B Starch Granules from Three Wheat Varieties

    Directory of Open Access Journals (Sweden)

    Haiyan Gao

    2011-12-01

    Full Text Available Three starches from the wheat varieties AK58, ZM18 and YZ4110 were separated into large (A and small (B granules, which were characterized structurally and evaluated for their functional properties. SEM results showed that the size of A-granules from ZM18 and YZ4110 were about the same, but the sizes of A-granules and B-granules from AK58 were larger than those of ZM18 and YZ4110. FTIR spectra showed that all the samples exhibited a similar pattern, with seven main modes with maximum absorbance peaks near 3,500, 3,000, 1,600, 1,400, 1,000, 800, 500 cm−1. The B-granules of ZM18 and YZ4110 had less amylose content, although the difference among the total amylose contents of the three unfractionated starches was not significant. X-ray diffraction (XRD patterns showed predominantly A-type crystallinity for all the starches. The A-granules showed sharper XRD patterns than the other starches. DSC analysis showed that the A-granules had broader ranges of gelatinization temperatures than the B-granules from the same wheat variety. The gelatinization enthalpy (ΔH of A-granules was higher than that of B-granules. AK58 exhibited the smallest enthalpy, while ZM18 showed the largest enthalpy. In pasting tests, the A-granule starch of AK58 had higher peak, final and setback viscosity, lower breakdown and pasting temperature, and the B-granule starch and unfractionated starch of AK58 had lower peak, breakdown, final and setback viscosity and higher pasting temperature than ZM18 and YZ4110.

  1. HIGH SHEAR GRANULATION PROCESS: ASSESSING IMPACT OF FORMULATION VARIABLES ON GRANULES AND TABLETS CHARACTERISTICS OF HIGH DRUG LOADING FORMULATION USING DESIGN OF EXPERIMENT METHODOLOGY.

    Science.gov (United States)

    Fayed, Mohamed H; Abdel-Rahman, Sayed I; Alanazi, Fars K; Ahmed, Mahrous O; Tawfeek, Hesham M; Ali, Bahaa E

    2017-03-01

    High shear wet granulation is a significant component procedure in the pharmaceutical industry. The objective of the study was to investigate the influence of two independent formulation variables; polyvinypyrrolidone (PVP) as a binder (X,) and croscarmellose sodium (CCS) as a disintegrant (X2) on the crit- ical quality attributes of acetaminophen granules and their corresponding tablets using design of experiment (DoE) approach. A two factor, three level (32) full factorial design has been applied; each variable was investi- gated at three levels to characterize their strength and interaction. The dried granules have been analyzed for their density, granule size and flowability. Additionally, the produced tablets have been investigated for: break- ing force, friability, disintegration time and t. of drug dissolution. The analysis of variance (ANOVA) showed that the two variables had a significant impact (p < 0.05) on granules and tablets characteristics, while only the binder concentration influenced the tablets friability. Furthermore, significant interactions (p < 0.05) between the two variables, for granules and tablets attributes, were also found. However, variables interaction showed minimal effect for granules flowability as well as tablets friability. Desirability function was carried out to opti- mize the variables under study to obtain product within the USP limit. It was found that the higher desirability (0.985) could be obtained at the medium level of PVP and low level of CCS. Ultimately, this study supplies the formulator with beneficial tools in selecting the proper level of binder and disintegrant to attain product with desired characteristics.

  2. Role of adaptor proteins in secretory granule biogenesis and maturation

    Directory of Open Access Journals (Sweden)

    Mathilde L Bonnemaison

    2013-08-01

    Full Text Available In the regulated secretory pathway, secretory granules (SGs store peptide hormones that are released on demand. SGs are formed at the trans-Golgi network (TGN and must undergo a maturation process to become responsive to secretagogues. The production of mature SGs requires concentrating newly synthesized soluble content proteins in granules whose membranes contain the appropriate integral membrane proteins. The mechanisms underlying the sorting of soluble and integral membrane proteins destined for SGs from other proteins are not yet well understood. For soluble proteins, luminal pH and divalent metals can affect aggregation and interaction with surrounding membranes. The trafficking of granule membrane proteins can be controlled by both luminal and cytosolic factors. Cytosolic adaptor proteins, which recognize the cytosolic domains of proteins that span the SG membrane, have been shown to play essential roles in the assembly of functional SGs. Adaptor protein 1A (AP-1A is known to interact with specific motifs in its cargo proteins and with the clathrin heavy chain, contributing to the formation of a clathrin coat. AP-1A is present in patches on immature SG membranes, where it removes cargo and facilitates SG maturation. AP-1A recruitment to membranes can be modulated by PACS-1 (Phosphofurin Acidic Cluster Sorting protein 1, a cytosolic protein which interacts with both AP-1A and cargo that has been phosphorylated by casein kinase II. A cargo/PACS-1/AP-1A complex is necessary to drive the appropriate transport of several cargo proteins within the regulated secretory pathway. The GGA (Golgi-localized, -ear containing, ADP-ribosylation factor binding family of adaptor proteins serve a similar role. We review the functions of AP-1A, PACS-1 and GGAs in facilitating the retrieval of proteins from immature SGs and review examples of cargo proteins whose trafficking within the regulated secretory pathway is governed by adaptor proteins.

  3. Feasibility study of hydrogen generator with molten slag granulation

    Energy Technology Data Exchange (ETDEWEB)

    Akiyama, T.; Mizuochi, T. [Graduate School of Engineering, Osaka Pref. Univ., Sakai, Osaka (Japan); Yagi, J.I.; Nogami, H. [Inst. of Multidisciplinary Research for Advanced Materials, Tohoku Univ., Aobaku, Sendai (Japan)

    2004-02-01

    A huge amount of hot molten oxides, such as steelmaking slag and molten municipal waste, is discharged at present without heat recovery, in spite of its very high potential. For example, hot molten slag as a byproduct in the Japanese steelmaking industry, over 1723 K in temperature, reaches as much as 30 million tonnes annually. To recover heat of the viscous slag chemically, the strongly endothermic reaction CH{sub 4}+H{sub 2}O {yields} 3H{sub 2}+CO was selected and then the property of dry granulation of the molten slag by rotary cup atomizer (RCA) for expanding surface area of the slag was experimentally studied. The purpose of this paper was, therefore, to study slag granulation under various conditions for promoting heat exchange between slag and gas, in which the influence of the rotating speed and the shape of the cup on the slag drop size was mainly examined. The collected slag drops were correlated with operating conditions such as rotating speed, cup shape, etc. Most significantly, the molten slag was successfully granulated under the dry conditions without water impingement. The rotating speed of the cup influenced the diameter and shape of the slag drops very strongly. The higher rotating speed made the slag drops smaller, more spherical and uniform. Drops with 5 to 6 mm of average dimension were obtained at a rotating speed of 15 rps (900 rpm), and drops with about 1 mm at 50 rps (3000 rpm). In the former case, the shape of the obtained drops changed from spherical to ribbon-like. These results will be useful to establish new heat recovery processes with hydrogen generation from molten slag with many benefits. Energy analysis and cost evaluation were also conducted, to study the benefit of the proposed process. (orig.)

  4. DEM Modelling of Granule Rearrangement and Fracture Behaviours During a Closed-Die Compaction.

    Science.gov (United States)

    Furukawa, Ryoichi; Kadota, Kazunori; Noguchi, Tetsuro; Shimosaka, Atsuko; Shirakawa, Yoshiyuki

    2017-08-01

    The closed-die compaction behaviour of D-mannitol granules has been simulated by the discrete element method (DEM) to investigate the granule rearrangement and fracture behaviour during compaction which affects the compactibility of the tablet. The D-mannitol granules produced in a fluidized bed were modelled as agglomerates of primary particles connected by linear spring bonds. The validity of the model granule used in the DEM simulation was demonstrated by comparing to the experimental results of a uniaxial compression test. During uniaxial compression, the numerical results of the force-displacement curve corresponded reasonably well to the experimental data. The closed-die compaction of the modelled granules was carried out to investigate the rearrangement and fracture behaviours of the granule at different upper platen velocities. The forces during closed-die compaction calculated by DEM fluctuated in the low-pressure region due to the rearrangement of granules. A Heckel analysis showed that the force fluctuation occurred at the initial bending region of the Heckel plot, which represents the granule rearrangement and fracture. Furthermore, the upper platen velocity affected the trend of compaction forces, which can lead to compaction failure due to capping. These results could contribute to designing the appropriate granules during closed-die compaction.

  5. P granules phase transition induced by cytoplasmic streaming in Caenorhabditis elegans embryo

    Science.gov (United States)

    Wang, Hang; Hu, GuoHui

    2017-01-01

    P granules are germ granules contained in Caenorhabditis elegans germ cells. The first germ cell is specified by the one-cell embryo in which P granules localize to the posterior. Previous studies suggested that the mechanism of the localization phenomena is induced by liquid-liquid phase transition (LLPT), in which the polarity proteins control the saturation point of P granules. In the present study, we propose that the P granules phase transition can be triggered by the cytoplasmic streaming. A two-phase flow model is employed to simulate the localization of P granules, i.e., the cytoplasm is considered as a liquid phase, and the droplet-like P granules are another liquid phase. With the presence of the cytoplasmic streaming, P granules, initially distributing uniformly in the entire one-cell embryo, eventually condense/dissolve in the cytoplasm phase, regulated by difference between the saturation pressure and the hydrodynamic pressure. The numerical results reveal that the cytoplasmic streaming has significant effects on the localization of P granules, as well as the embryo division.

  6. Layered growth with bottom-spray granulation for spray deposition of drug.

    Science.gov (United States)

    Er, Dawn Z L; Liew, Celine V; Heng, Paul W S

    2009-07-30

    The gap in scientific knowledge on bottom-spray fluidized bed granulation has emphasized the need for more studies in this area. This paper comparatively studied the applicability of a modified bottom-spray process and the conventional top-spray process for the spray deposition of a micronized drug during granulation. The differences in circulation pattern, mode of growth and resultant granule properties between the two processes were highlighted. The more ordered and consistent circulation pattern of particles in a bottom-spray fluidized bed was observed to give rise to layered granule growth. This resulted in better drug content uniformity among the granule batches and within a granule batch. The processes' sensitivities to wetting and feed material characteristics were also compared and found to differ markedly. Less robustness to differing process conditions was observed for the top-spray process. The resultant bottom-spray granules formed were observed to be less porous, more spherical and had good flow properties. The bottom-spray technique can thus be potentially applied for the spray deposition of drug during granulation and was observed to be a good alternative to the conventional technique for preparing granules.

  7. Formation mechanism of nitrifying granules observed in an aerobic upflow fluidized bed (AUFB) reactor.

    Science.gov (United States)

    Tsuneda, S; Ejiri, Y; Nagano, T; Hirata, A

    2004-01-01

    The influences of trace metals in the wastewater and shear stress by aeration were particularly examined to clarify the formation mechanism of nitrifying granules in an aerobic upflow fluidized bed (AUFB) reactor. It was found that Fe added as a trace element to the inorganic wastewater accumulated at the central part of the nitrifying granules. Another result obtained was that suitable shear stress by moderate aeration (0.07-0.20 L/min/L-bed) promoted granulation. Furthermore, it was successfully demonstrated that pre-aggregation of seed sludge using hematite promoted core formation, leading to rapid production of nitrifying granules. From these results, a nitrifying granulation mechanism is proposed: 1) as a first step, nitrifying bacteria aggregate along with Fe precipitation, and then the cores of granules are formed; 2) as a second step, the aggregates grow to be spherical or elliptical in form due to multiplication of the nitrifying bacteria and moderate shear stress in the reactor, and then mature nitrifying granules are produced. Fluorescence in situ hybridization (FISH) analysis successfully visualized the change in the spatial distribution of nitrifying bacteria in the granules, which supports the proposed granulation mechanism.

  8. Adipose derived mesenchymal stem cells - their osteogenicity and osteoblast in vitro mineralization on titanium granule carriers.

    Science.gov (United States)

    Dahl, Morten; Syberg, Susanne; Jørgensen, Niklas Rye; Pinholt, Else Marie

    2013-12-01

    Adipose derived mesenchymal stem cells (ADMSCs) may be osteogenic, may generate neoangiogenisis and may be progenitors for differentiated osteoblast mineralization. Titanium granules may be suitable as carriers for these cells. The aim was to demonstrate the osteogenic potential of ADMSCs and the effect of porous non-oxidized (Ti) and oxidized titanium (TiO2) granules as carriers for ADMSCs mineralization in vitro. ADMSCs were isolated, cultivated in osteoblast medium and evaluated for alkaline phosphatase (ALP) assay, RNA isolation, and ALP staining. Osteoblast in vitro mineralization cells without granules or seeded on Ti or TiO2 granules were evaluated for Alizarin Red assay and RNA isolation for later gene expressing. ADMSCs express osteoblastic lineage genes, CBFA-1 and stain strongly for ALP. Mineralization was significantly higher for cells seeded on TiO2 than on Ti granules or pure cells. Expression of ALPL and RUNX2 was significantly higher for cells seeded on TiO2 granules and expression of COL1α1 for pure cells was significantly higher than for cells seeded on granules. ADMSCs have osteogenic potential. Mineralization was significantly high when cells were seeded on TiO2 granules. TiO2 granules may be used as carriers for adipose derived mesenchymal osteoblastic cells from laboratory bench to the patient. Copyright © 2013 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  9. The Effect of Wetting on The Course of The Drum Granulation

    Directory of Open Access Journals (Sweden)

    Błaszczyk Michał

    2017-06-01

    Full Text Available This paper presents the results of experimental drum granulation of silica flour with the use of wetting liquids with different values of surface tension. Additionally, different liquid jet breakup and different residual moisture of the bed were applied in the tests. The process was conducted periodically in two stages: wetting and proper granulation, during which no liquid was supplied to the bed. The condition of the granulated material after the period of wetting (particle size distribution and moisture of separate fractions and a change in the particle size distribution during the further conduct of the process (granulation kinetics were determined.

  10. Injected mass deposition thresholds for lithium granule instigated triggering of edge localized modes on EAST

    Science.gov (United States)

    Lunsford, R.; Sun, Z.; Maingi, R.; Hu, J. S.; Mansfield, D.; Xu, W.; Zuo, G. Z.; Diallo, A.; Osborne, T.; Tritz, K.; Canik, J.; Huang, M.; Meng, X. C.; Gong, X. Z.; Wan, B. N.; Li, J. G.; the EAST team

    2018-03-01

    The ability of an injected lithium granule to promptly trigger an edge localized mode (ELM) has been established in multiple experiments. By horizontally injecting granules ranging in diameter from 200 microns to 1 mm in diameter into the low field side of EAST H-mode discharges we have determined that granules with diameter  >600 microns are successful in triggering ELMs more than 95% of the time. It was also demonstrated that below 600 microns the triggering efficiency decreased roughly with granule size. Granules were radially injected from the outer midplane with velocities ~80 m s‑1 into EAST upper single null discharges with an ITER like tungsten monoblock divertor. These granules were individually tracked throughout their injection cycle in order to determine their efficacy at triggering an ELM. For those granules of sufficient size, ELM triggering was a prompt response to granule injection. By simulating the granule injection with an experimentally benchmarked neutral gas shielding (NGS) model, the ablatant mass deposition required to promptly trigger an ELM is calculated and the fractional mass deposition is determined.

  11. Application of continuous twin screw granulation for the metformin hydrochloride extended release formulation.

    Science.gov (United States)

    Kim, Su-Hyeon; Hwang, Kyu-Min; Cho, Cheol-Hee; Nguyen, Thi-Tram; Seok, Su Hyun; Hwang, Kyu-Mok; Kim, Ju-Young; Park, Chun-Woong; Rhee, Yun-Seok; Park, Eun-Seok

    2017-08-30

    This study focuses on evaluating the potential of transferring from a batch process to continuous process for manufacturing of the extended release formulation. Metformin hydrochloride (HCl) was used in the model formulation which was intended to contain the high amount of hydrophilic drug. The effects of barrel temperature, binder type, powder feed rate, and screw speed on granule properties (size and strength) and torque value in twin screw granulation were investigated. Due to the high content of hydrophilic model drug, the granules prepared at a higher temperature with HPMC binding solution had the narrower size distribution and greater strength than the granules prepared with distilled water as a binding solution. After continuous drying and milling steps, the granules (continuous process) satisfied the fundamental purpose of granulation with size and flowability, despite different shape compared with the granules (batch process). Furthermore, there were no significant differences between two granulation processes in tablet properties, such as tablet hardness and in vitro release. The considerations and strategies used in this study to transfer from a batch to continuous process can be applied to other existing formulations based on high shear granulation to enable rapid process transfer in the pharmaceutical industry. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Three novel proteins co-localise with polyhydroxybutyrate (PHB) granules in Rhodospirillum rubrum S1.

    Science.gov (United States)

    Narancic, Tanja; Scollica, Elisa; Cagney, Gerard; O'Connor, Kevin E

    2018-04-01

    Polyhydroxybutyrate (PHB), a biodegradable polymer accumulated by bacteria is deposited intracellularly in the form of inclusion bodies often called granules. The granules are supramolecular complexes harbouring a varied number of proteins on their surface, which have specific but incompletely characterised functions. By comparison with other organisms that produce biodegradable polymers, only two phasins have been described to date for Rhodosprillum rubrum, raising the possibility that more await discovery. Using a comparative proteomics strategy to compare the granules of wild-type R. rubrum with a PHB-negative mutant housing artificial PHB granules, we identified four potential PHB granules' associated proteins. These were: Q2RSI4, an uncharacterised protein; Q2RWU9, annotated as an extracellular solute-binding protein; Q2RQL4, annotated as basic membrane lipoprotein; and Q2RQ51, annotated as glucose-6-phosphate isomerase. In silico analysis revealed that Q2RSI4 harbours a Phasin_2 family domain and shares low identity with a single-strand DNA-binding protein from Sphaerochaeta coccoides. Fluorescence microscopy found that three proteins Q2RSI4, Q2EWU9 and Q2RQL4 co-localised with PHB granules. This work adds three potential new granule associated proteins to the repertoire of factors involved in bacterial storage granule formation, and confirms that proteomics screens are an effective strategy for discovery of novel granule associated proteins.

  13. In vivo and in vitro observations of polyhydroxybutyrate granules formed by Dinoroseobacter sp. JL 1447.

    Science.gov (United States)

    Xiao, Na; Jiao, Nianzhi; Liu, Yongqin

    2015-03-01

    Polyhydroxybutyrate (PHB) granules formed by a marine aerobic anoxygenic phototrophic bacterial strain Dinoroseobacter sp. JL 1447 were detected using transmission electron microscopy and atomic force microscopy. When Dinoroseobacter sp. JL 1447 was inoculated into a medium with glucose as the sole carbon source, the formation of PHB granules occurred and accumulated with incubation time, reaching their maximum in the stationary phase cultures. PHB granules, formed in the cytoplasm at the cell poles or future cell poles, were remobilized and used by the cells in late stationary complex cultures. When PHB granules formed, cell length elongated from 0.5 to 1.5 μm and spherical protrusions appeared on the cell surface. The French press method was used to break the cells and isolate the PHB granules. The freshly prepared and intact PHB granules were spherical with a soft, smooth outer envelope without visible substructures. Upon treating PHB granules with sodium dodecyl sulfate, the envelope was destroyed and nearly parted from the granules, and uniform, spherical structures with a central pore appeared on the granule surface. Copyright © 2015. Published by Elsevier B.V.

  14. Comparison of Ca2+ and Mg2+ enhancing aerobic granulation in SBR

    International Nuclear Information System (INIS)

    Liu Lin; Gao Dawen; Zhang Min; Fu Yuan

    2010-01-01

    Two sequencing batch reactors (SBRs) were operated to investigate the effect of Ca 2+ and Mg 2+ augmentation on aerobic granulation. Reactor R1 was augmented with Ca 2+ at 40 mg/L, while Mg 2+ was added to the reactor R2 with 40 mg/L. Results showed that the reactor R1 had a faster granulation process compared with R2, and the mature granules in R1 showed better physical characteristics. However, the mature granules in R2 had the higher production yield of polysaccharides and proteins, and aerobic granules in R2 experienced a faster substrate biodegradation. Microbial and genetic characteristics in mature granules were analyzed using polymerase chain reaction (PCR) and denaturing gradient gel electrophoresis (DGGE) techniques. The results revealed that Mg 2+ addition led to higher microbial diversity in mature granules. In addition, an uncultured bacterium (AB447697) was major specie in R1, and β-proteobacterium was dominant in R2. It can be concluded that Ca 2+ had an important effect on physical properties of aerobic granules, while Mg 2+ played a key role on biological properties during the sludge granulation.

  15. Effect of granule properties on rough mouth feel and palatability of orally disintegrating tablets.

    Science.gov (United States)

    Kimura, Shin-Ichiro; Uchida, Shinya; Kanada, Ken; Namiki, Noriyuki

    2015-04-30

    In this study, we evaluated the palatability of orally disintegrating tablets (ODTs) containing core granules with different particle sizes, coating, and types of materials using visual analog scales (VAS). Tableting the core granules into ODTs reduced rough mouth feel and improved overall palatability compared to the ingestion of core granules alone. Moreover, the evaluation performed immediately after spitting out ODTs demonstrated differences in rough mouth feel between ODTs containing placebo and core granules. Rough mouth feel was found to be significantly more intense with core granules with particle sizes ≥ 200 μm. Since ODTs may contain taste-masked particles, palatability of ODTs containing coated core granules was also evaluated. Although coating with polymers impairs palatability, it was improved by coating the outer layer with d-mannitol. The effects on palatability of materials constituting core granules were also evaluated, with reduced rough mouth feel observed with core granules composed of water-soluble additives. Based on these data, receiver operating characteristic analysis was performed to determine the threshold VAS scores at which the subjects felt roughness and discomfort. In addition, the threshold particle size of the core granule contained within the ODT required for feeling roughness was determined to be 244 μm. This study elucidated the effect of the properties of masking particles on the rough mouth feel and palatability of ODTs. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Role of the Caenorhabditis elegans multidrug resistance gene, mrp-4, in gut granule differentiation.

    Science.gov (United States)

    Currie, Erin; King, Brian; Lawrenson, Andrea L; Schroeder, Lena K; Kershner, Aaron M; Hermann, Greg J

    2007-11-01

    Caenorhabditis elegans gut granules are lysosome-related organelles with birefringent contents. mrp-4, which encodes an ATP-binding cassette (ABC) transporter homologous to mammalian multidrug resistance proteins, functions in the formation of gut granule birefringence. mrp-4(-) embryos show a delayed appearance of birefringent material in the gut granule but otherwise appear to form gut granules properly. mrp-4(+) activity is required for the extracellular mislocalization of birefringent material, body-length retraction, and NaCl sensitivity, phenotypes associated with defective gut granule biogenesis exhibited by embryos lacking the activity of GLO-1/Rab38, a putative GLO-1 guanine nucleotide exchange factor GLO-4, and the AP-3 complex. Multidrug resistance protein (MRP)-4 localizes to the gut granule membrane, consistent with it playing a direct role in the transport of molecules that compose and/or facilitate the formation of birefringent crystals within the gut granule. However, MRP-4 is also present in oocytes and early embryos, and our genetic analyses indicate that its site of action in the formation of birefringent material may not be limited to just the gut granule in embryos. In a search for genes that function similarly to mrp-4(+), we identified WHT-2, another ABC transporter that acts in parallel to MRP-4 for the formation of birefringent material in the gut granule.

  17. Common spectrum of polypeptides occurs in secretion granule membranes of different exocrine glands

    International Nuclear Information System (INIS)

    Cameron, R.S.; Cameron, P.L.; Castle, J.D.

    1986-01-01

    A highly purified membrane preparation from rat parotid secretion granules has been used as a comparative probe to examine the extent of compositional overlap in granule membranes of three other exocrine secretory tissues - pancreatic, lacrimal, and submandibular - from several standpoints. First, indirect immunofluorescent studies using a polyclonal polyspecific anti-parotid granule membrane antiserum has indicated a selective staining of granule membrane profiles in all acinar cells of all tissues. Second, highly purified granule membrane subfractions have been isolated from each exocrine tissue; comparative two-dimensional (isoelectric focusing; SDS) PAGE of radioiodinated granule membranes has identified 10-15 polypeptides of identical pI and apparent molecular mass. These species are likely to be integral membrane components since they are not extracted by either saponin-sodium sulfate or sodium carbonate (pH 11.5) treatments, and they do not have counterparts in the granule content. Finally, the identity among selected parotid and pancreatic radioiodinated granule membrane polypeptides has been documented using two-dimensional peptide mapping of chymotryptic and tryptic digests. These findings clearly indicate that exocrine secretory granules, irrespective of the nature of stored secretion, comprise a type of vesicular carrier with a common (and probably refined) membrane composition. Conceivably, the polypeptides identified carry out general functions related to exocrine secretion

  18. Midline 1 directs lytic granule exocytosis and cytotoxicity of mouse killer T cells

    DEFF Research Database (Denmark)

    Boding, Lasse; Hansen, Ann K; Meroni, Germana

    2014-01-01

    upregulated in murine cytotoxic lymphocytes (CTLs), and that it controls TCR signaling, centrosome trafficking and exocytosis of lytic granules. In accordance, we find that the killing capacity of MID1(-/-) CTLs is impaired. Transfection of MID1 into MID1(-/-) CTLs completely rescued lytic granule exocytosis......, and vice versa, knock-down of MID1 inhibited exocytosis of lytic granules in wild-type CTLs, cementing a central role for MID1 in the regulation of granule exocytosis. Thus, MID1 orchestrates multiple events in CTL responses, adding a novel level of regulation to CTL activation and cytotoxicity...

  19. Who Regulates Whom? An Overview of RNA Granules and Viral Infections

    Directory of Open Access Journals (Sweden)

    Natalia Poblete-Durán

    2016-06-01

    Full Text Available After viral infection, host cells respond by mounting an anti-viral stress response in order to create a hostile atmosphere for viral replication, leading to the shut-off of mRNA translation (protein synthesis and the assembly of RNA granules. Two of these RNA granules have been well characterized in yeast and mammalian cells, stress granules (SGs, which are translationally silent sites of RNA triage and processing bodies (PBs, which are involved in mRNA degradation. This review discusses the role of these RNA granules in the evasion of anti-viral stress responses through virus-induced remodeling of cellular ribonucleoproteins (RNPs.

  20. Microbial community structure and biodiversity of size-fractionated granules in a partial nitritation-anammox process.

    Science.gov (United States)

    Luo, Jinghuan; Chen, Hui; Han, Xiaoyu; Sun, Yanfang; Yuan, Zhiguo; Guo, Jianhua

    2017-06-01

    The performance of a granule-based partial nitritation-anammox process is expected to be affected by the granule size distribution, but little is known about the impact of granule size on microbial community structure and diversity. To reveal how the microbial composition and diversity vary with granule size, granules from a partial nitritation-anammox reactor were size-fractionated into five classes (1.0 mm). Microbial communities and diversity in these size-fractionated granules were investigated using 16S rRNA gene high-throughput sequencing. It was found that larger granules harbor more diverse microbial communities than small granules. Both quantitative PCR and 16S rRNA gene sequencing indicated that the abundance of anammox bacteria (dominated by Candidatus Brocadia) exhibited an increasing trend with granule size. In contrast, the abundance of ammonia-oxidizing bacteria (Nitrosomonas) decreased with increasing granule size. Moreover, larger granules harbored more diverse anammox bacteria, with four genera found in the largest granules while only two with limited abundance were detected in the smallest granules. The findings highlight an important role for granule size in shaping community structure and biodiversity. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  1. Tachykinin neuropeptides in cerebellar granule neurons: an immunocytochemical study

    Directory of Open Access Journals (Sweden)

    C Barbato

    2009-06-01

    Full Text Available We previously demonstrated that exogenously administered neurokinin A and neurokinin B, but not substance P, increased the sensitivity of cultured cerebellar granule neurons (CGNs to glutamate. In the present study, the presence of tachykinin neuropeptides in CGNs was tested by confocalbased immunofluorescence.We found that neurokinin A and neurokinin B are present in CGNs but absent in astrocytes. while substance P is abundant in astrocytes but absent in CGNs. It is postulated that the different localization of tachykinin neuropeptides in CGNs and astroglial cells has a physiological role in the modulation of excitatory transmission.

  2. Evidence for transonic flows in the solar granulation

    Science.gov (United States)

    Nesis, A.; Bogdan, T. J.; Cattaneo, F.; Hanslmeier, A.; Knoelker, M.; Malagoli, A.

    1992-01-01

    High-resolution observations of the solar granulation are interpreted in the light of recent numerical simulations of compressible convection. The observations show a negative correlation between the width of suitably chosen, nonmagnetic lines and the continuum intensity. This result is consistent with a model of granular convection where regions of supersonic horizontal flow form intermittently in the vicinity of the downflow lanes. We conjecture that the observed line broadening in the regions of low intensity is caused by enhanced turbulent fluctuations generated by the passage of shock fronts bounding the regions of supersonic motion.

  3. HIGH-SHEAR GRANULATION PROCESS: INFLUENCE OF PROCESSING PARAMETERS ON CRITICAL QUALITY ATTRIBUTES OF ACETAMINOPHEN GRANULES AND TABLETS USING DESIGN OF EXPERIMENT APPROACH.

    Science.gov (United States)

    Fayed, Mohamed H; Abdel-Rahman, Sayed I; Alanazi, Fars K; Ahmed, Mahrous O; Tawfeek, Hesham M; Al-Shedfat, Ramadan I

    2017-01-01

    Application of quality by design (QbD) in high shear granulation process is critical and need to recognize the correlation between the granulation process parameters and the properties of intermediate (granules) and corresponding final product (tablets). The present work examined the influence of water amount (X,) and wet massing time (X2) as independent process variables on the critical quality attributes of granules and corresponding tablets using design of experiment (DoE) technique. A two factor, three level (32) full factorial design was performed; each of these variables was investigated at three levels to characterize their strength and interaction. The dried granules have been analyzed for their size distribution, density and flow pattern. Additionally, the produced tablets have been investigated for weight uniformity, crushing strength, friability and percent capping, disintegration time and drug dissolution. Statistically significant impact (p < 0.05) of water amount was identified for granule growth, percent fines and distribution width and flow behavior. Granule density and compressibility were found to be significantly influenced (p < 0.05) by the two operating conditions. Also, water amount has significant effect (p < 0.05) on tablet weight unifornity, friability and percent capping. Moreover, tablet disintegration time and drug dissolution appears to be significantly influenced (p < 0.05) by the two process variables. On the other hand, the relationship of process parameters with critical quality attributes of granule and final product tablet was identified and correlated. Ultimately, a judicious selection of process parameters in high shear granulation process will allow providing product of desirable quality.

  4. New gentle-wing high-shear granulator: impact of processing variables on granules and tablets characteristics of high-drug loading formulation using design of experiment approach.

    Science.gov (United States)

    Fayed, Mohamed H; Abdel-Rahman, Sayed I; Alanazi, Fars K; Ahmed, Mahrous O; Tawfeek, Hesham M; Al-Shdefat, Ramadan I

    2017-10-01

    The aim of this work was to study the application of design of experiment (DoE) approach in defining design space for granulation and tableting processes using a novel gentle-wing high-shear granulator. According to quality-by-design (QbD) prospective, critical attributes of granules, and tablets should be ensured by manufacturing process design. A face-centered central composite design has been employed in order to investigate the effect of water amount (X 1 ), impeller speed (X 2 ), wet massing time (X 3 ), and water addition rate (X 4 ) as independent process variables on granules and tablets characteristics. Acetaminophen was used as a model drug and granulation experiments were carried out using dry addition of povidone k30. The dried granules have been analyzed for their size distribution, density, and flow pattern. Additionally, the produced tablets have been investigated for; weight uniformity, breaking force, friability and percent capping, disintegration time, and drug dissolution. Results of regression analysis showed that water amount, impeller speed and wet massing time have significant (p tablets characteristics. However, the water amount had the most pronounced effect as indicated by its higher parameter estimate. On the other hand, water addition rate showed a minimal impact on granules and tablets properties. In conclusion, water amount, impeller speed, and wet massing time could be considered as critical process variables. Thus, understanding the relationship between these variables and quality attributes of granules and corresponding tablets provides the basis for adjusting granulation variables in order to optimize product performance.

  5. [Quantitative structure characteristics and fractal dimension of Chinese medicine granules measured by synchrotron radiation X-ray computed micro tomography].

    Science.gov (United States)

    Lu, Xiao-long; Zheng, Qin; Yin, Xian-zhen; Xiao, Guang-qing; Liao, Zu-hua; Yang, Ming; Zhang, Ji-wen

    2015-06-01

    The shape and structure of granules are controlled by the granulation process, which is one of the main factors to determine the nature of the solid dosage forms. In this article, three kinds of granules of a traditional Chinese medicine for improving appetite and promoting digestion, namely, Jianwei Granules, were prepared using granulation technologies as pendular granulation, high speed stirring granulation, and fluidized bed granulation and the powder properties of them were investigated. Meanwhile, synchrotron radiation X-ray computed micro tomography (SR-µCT) was applied to quantitatively determine the irregular internal structures of the granules. The three-dimensional (3D) structure models were obtained by 3D reconstruction, which were more accurately to characterize the three-dimensional structures of the particles through the quantitative data. The models were also used to quantitatively compare the structural differences of granules prepared by different granulation processes with the same formula, so as to characterize how the production process plays a role in the pharmaceutical behaviors of the granules. To focus on the irregularity of the particle structure, the box counting method was used to calculate the fractal dimensions of the granules. The results showed that the fractal dimension is more sensitive to reflect the minor differences in the structure features than the conventional parameters, and capable to specifically distinct granules in structure. It is proved that the fractal dimension could quantitatively characterize the structural information of irregular granules. It is the first time suggested by our research that the fractal dimension difference (Df,c) between two fractal dimension parameters, namely, the volume matrix fractal dimension and the surface matrix fractal dimension, is a new index to characterize granules with irregular structures and evaluate the effects of production processes on the structures of granules as a new

  6. Wolfram syndrome 1 gene (WFS1) product localizes to secretory granules and determines granule acidification in pancreatic beta-cells.

    Science.gov (United States)

    Hatanaka, Masayuki; Tanabe, Katsuya; Yanai, Akie; Ohta, Yasuharu; Kondo, Manabu; Akiyama, Masaru; Shinoda, Koh; Oka, Yoshitomo; Tanizawa, Yukio

    2011-04-01

    Wolfram syndrome is an autosomal recessive disorder characterized by juvenile-onset insulin-dependent diabetes mellitus and optic atrophy. The gene responsible for the syndrome (WFS1) encodes an endoplasmic reticulum (ER) resident transmembrane protein. The Wfs1-null mouse exhibits progressive insulin deficiency causing diabetes. Previous work suggested that the function of the WFS1 protein is connected to unfolded protein response and to intracellular Ca(2+) homeostasis. However, its precise molecular function in pancreatic β-cells remains elusive. In our present study, immunofluorescent and electron-microscopic analyses revealed that WFS1 localizes not only to ER but also to secretory granules in pancreatic β-cells. Intragranular acidification was assessed by measuring intracellular fluorescence intensity raised by the acidotrophic agent, 3-[2,4-dinitroanilino]-3'-amino-N-methyldipropyramine. Compared with wild-type β-cells, there was a 32% reduction in the intensity in WFS1-deficient β-cells, indicating the impairment of granular acidification. This phenotype may, at least partly, account for the evidence that Wfs1-null islets have impaired proinsulin processing, resulting in an increased circulating proinsulin level. Morphometric analysis using electron microscopy evidenced that the density of secretory granules attached to the plasma membrane was significantly reduced in Wfs1-null β-cells relative to that in wild-type β-cells. This may be relevant to the recent finding that granular acidification is required for the priming of secretory granules preceding exocytosis and may partly explain the fact that glucose-induced insulin secretion is profoundly impaired in young prediabetic Wfs1-null mice. These results thus provide new insights into the molecular mechanisms of β-cell dysfunction in patients with Wolfram syndrome.

  7. Improved tabletability after a polymorphic transition of delta-mannitol during twin screw granulation.

    Science.gov (United States)

    Vanhoorne, V; Bekaert, B; Peeters, E; De Beer, T; Remon, J-P; Vervaet, C

    2016-06-15

    In most formulations processed via continuous twin screw granulation microcrystalline cellulose (MCC) and/or lactose are used as excipients, but mannitol is also a preferred excipient for wet granulation and tableting due to its non-hygroscopicity and inertness. Therefore, the aim of the current study was to investigate the influence of process parameters on critical quality attributes of granules (moisture content, solid state, morphology, size distribution, specific surface area, friability, flowability and hygroscopicity) and tablets (tensile strength and friability) after twin screw granulation of δ-mannitol. The δ-polymorph was selected since a moisture-induced transformation to β-mannitol was observed during batch wet granulation, which exhibited a unique morphology with a large surface area and improved tabletability. A full factorial experimental design was performed, varying screw speed (400-900rpm), granulation temperature (25-40°C), number of kneading elements (6 or 12) and liquid-to-solid (L/S) ratio, on the granulation unit of a ConsiGma™-25 line (a continuous powder-to-tablet manufacturing system). After tray drying the granules were milled and tableted. The results showed that the polymorphic transition from δ- to β-mannitol also occurred during twin screw granulation, although the residence time and L/S ratios were much lower in continuous twin screw granulation compared to batch processing. However, the polymorphic transition was not complete in all experiments and depended on the L/S ratio, screw speed and number of kneading elements. Nevertheless all granules exhibited the unique morphology linked to the polymorphic transition and had a superior tabletability compared to granules produced with β-mannitol as starting material. This was attributed to enhanced plastic deformation of the granules manufactured using δ-mannitol as starting material. In addition, it was concluded that mannitol was granulated via a different mechanism than

  8. High Plasticity of New Granule Cells in the Aging Hippocampus

    Directory of Open Access Journals (Sweden)

    Mariela F. Trinchero

    2017-10-01

    Full Text Available Summary: During aging, the brain undergoes changes that impair cognitive capacity and circuit plasticity, including a marked decrease in production of adult-born hippocampal neurons. It is unclear whether development and integration of those new neurons are also affected by age. Here, we show that adult-born granule cells (GCs in aging mice are scarce and exhibit slow development, but they display a remarkable potential for structural plasticity. Retrovirally labeled 3-week-old GCs in middle-aged mice were small, underdeveloped, and disconnected. Neuronal development and integration were accelerated by voluntary exercise or environmental enrichment. Similar effects were observed via knockdown of Lrig1, an endogenous negative modulator of neurotrophin receptors. Consistently, blocking neurotrophin signaling by Lrig1 overexpression abolished the positive effects of exercise. These results demonstrate an unparalleled degree of plasticity in the aging brain mediated by neurotrophins, whereby new GCs remain immature until becoming rapidly recruited to the network by activity. : Trinchero et al. show that development of new granule cells born in the adult hippocampus is strongly influenced by age. In the aging hippocampus, new neurons remain immature for prolonged intervals, yet voluntary exercise triggers their rapid growth and functional synaptogenesis. This extensive structural remodeling is mediated by neurotrophins. Keywords: adult neurogenesis, dentate gyrus, functional integration, neurotrophins, synaptogenesis, exercise

  9. Enteric coating of granules containing the probiotic Lactobacillus acidophilus

    Directory of Open Access Journals (Sweden)

    Pyar Hassan

    2014-06-01

    Full Text Available In the present study, a capsule formulation composed of enteric coated granules of Lactobacillus acidophilus ATCC 4962 was developed using Eudragit L30D-55 as enteric polymer. Optimization of the capsule formulation was achieved with a maximum viable cell count after 2 h of incubation in acid medium and disintegration time of 1 h in buffer pH 6.8. The amount of Eudragit L30D-55 in the capsules correlated with gastric juice resistance. The best protective qualities against artificial gastric juice were observed when capsules were prepared from granules composed of L. acidophilus, corn starch, lactose monohydrate, polyvinylpyrrolidone and coated with 12.5 % (m/V of Eudragit L30D-55. Capsule formulation of L. acidophilus in edible broth medium suspension serves as a cheap alternative to the expensive freeze-drying procedure for preparing L. acidophilus. In addition, the enteric coating using Eudragit L30D-55 could protect probiotics from the acidic gastric environment and enhance the bioactivity of probiotics along with replacement of pathogenic microbes in human intestine

  10. Enteric coating of granules containing the probiotic Lactobacillus acidophilus.

    Science.gov (United States)

    Pyar, Hassan; Peh, Kok-Khiang

    2014-06-01

    In the present study, a capsule formulation composed of enteric coated granules of Lactobacillus acidophilus ATCC 4962 was developed using Eudragit L30D-55 as enteric polymer. Optimization of the capsule formulation was achieved with a maximum viable cell count after 2 h of incubation in acid medium and disintegration time of 1 h in buffer pH 6.8. The amount of Eudragit L30D-55 in the capsules correlated with gastric juice resistance. The best protective qualities against artificial gastric juice were observed when capsules were prepared from granules composed of L. acidophilus, corn starch, lactose monohydrate, polyvinylpyrrolidone and coated with 12.5 % (m/V) of Eudragit L30D-55. Capsule formulation of L. acidophilus in edible broth medium suspension serves as a cheap alternative to the expensive freeze-drying procedure for preparing L. acidophilus. In addition, the enteric coating using Eudragit L30D-55 could protect probiotics from the acidic gastric environment and enhance the bioactivity of probiotics along with replacement of pathogenic microbes in human intestine.

  11. Tribology of swollen starch granule suspensions from maize and potato.

    Science.gov (United States)

    Zhang, Bin; Selway, Nichola; Shelat, Kinnari J; Dhital, Sushil; Stokes, Jason R; Gidley, Michael J

    2017-01-02

    The tribological properties of suspensions of cooked swollen starch granules are characterised for systems based on maize starch and potato starch. These systems are known as granule 'ghosts' due to the release (and removal) of polymer from their structure during cooking. Maize starch ghosts are less swollen than potato starch ghosts, resulting in a higher packing concentration and greater mechanical stability. In a soft-tribological contact, maize ghost suspensions reduce friction compared to the solvent (water), generate bell-shaped tribological profiles characteristic of particle entrainment and show a marked concentration dependence, whereas potato ghost suspensions exhibit lubrication behaviour similar to water. Microscopy analysis of the samples following tribological testing suggests that this is due to the rapid break-up of potato ghosts under the shear and rolling conditions within the tribological contact. A reduction in the small deformation moduli (associated with a weak gel structure) is also observed when the potato ghost suspensions are subjected to steady shear using parallel plate rheometry; both microscopy and particle size analysis show that this is accompanied by the partial shear-induced breakage of ghost particles. This interplay between particle microstructure and the resultant rheological and lubrication dynamics of starch ghost suspensions contributes to an enhanced mechanistic understanding of textural and other functional properties of cooked starches in food and other applications. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Biodegradation of p-nitrophenol by aerobic granules in a sequencing batch reactor.

    Science.gov (United States)

    Yi, Shan; Zhuang, Wei-Qin; Wu, Bing; Tay, Stephen Tiong-Lee; Tay, Joo-Hwa

    2006-04-01

    In this study, aerobic granules to treat wastewater containing p-nitrophenol (PNP) were successfully developed in a sequencing batch reactor (SBR) using activated sludge as inoculum. A key step was the conditioning of the activated sludge seed to enrich for biomass with improved settleability and higher PNP degradation activity by implementing progressive decreases in settling time and stepwise increases in PNP concentration. The aerobic granules were cultivated at a PNP loading rate of 0.6 kg/ m3 x day, with glucose to boost the growth of PNP-degrading biomass. The granules had a clearly defined shape and appearance, settled significantly faster than activated sludge, and were capable of nearly complete PNP removal. The granules had specific PNP degradation rates that increased with PNP concentration from 0 to 40.1 mg of PNP/L, peaked at 19.3 mg of PNP/(g of VSS) x h (VSS = volatile suspended solids), and declined with further increases in PNP concentration as substrate inhibition effects became significant. Batch incubation experiments show that the PNP-degrading granules could also degrade other phenolic compounds, such as hydroquinone, p-nitrocatechol, phenol, 2,4-dichlorophenol, and 2,6-dichlorophenol. The PNP-degrading granules contained diverse microbial morphotypes, and PNP-degrading bacteria accounted for 49% of the total culturable heterotrophic bacteria. Denaturing gradient gel electrophoresis analysis of 16S rRNA gene fragments showed a gradual temporal shift in microbial community succession as the granules developed from the activated sludge seed. Specific oxygen utilization rates at 100 mg/L PNP were found to increase with the evolution of smaller granules to large granules, suggesting that the granulation process can enhance metabolic efficiency toward biodegradation of PNP. The results in this study demonstrate that it is possible to use aerobic granules for PNP biodegradation and broadens the benefits of using the SBR to target treatment of toxic

  13. NEW METHODOLOGY FOR DEVELOPMENT OF ORODISPERSIBLE TABLETS USING HIGH-SHEAR GRANULATION PROCESS.

    Science.gov (United States)

    Ali, Bahaa E; Al-Shedfat, Ramadan I; Fayed, Mohamed H; Alanazi, Fars K

    2017-05-01

    Development of orodispersible delivery system of high mechanical properties and low disintegration time is a big challenge. The aim of the current work was to assess and optimize the high shear granulation process as a new methodology for development of orodispersible tablets of high quality attributes using design of experiment approach. A two factor, three levels (32), full factorial design was carried out to investigate the main and interaction effects of independent variables, water amount (XI) and granulation time (X2) on the characteristics of granules and final product, tablet. The produced granules were analyzed for their granule size, density and flowability. Furthermore, the produced tablets were tested for: weight variation, breaking force/ crushing strength, friability, disintegration time and drug dissolution. Regression analysis results of multiple linear models showed a high correlation between the adjusted R-squared and predicted R-squared for all granules and tablets characteristics, the difference is less than 0.2. All dependent responses of granules and tablets were found to be impacted significantly (p granules and tablet characteristics as shown by higher its coefficient estimate for all selected responses. Numerical optimization using desirability function was performed to optimize the variables under study to provide orodispersible system within the USP limit with respect of mechanical properties and disintegration time. It was found that the higher desirability (0.915) could be attained at the low level pf water (180 g) and short granulation time (1.65 min). Eventually, this study provides the formulator with helpful information in selecting the proper level of water and granulation time to provide an orodispersible system of high crushing strength and very low disintegration time, when high shear granulation methodology was used as a method of manufacture.

  14. Preparation of porcelain tile granulates by more environmentally sustainable processes

    Directory of Open Access Journals (Sweden)

    García-Ten, J.

    2012-04-01

    Full Text Available This study examines the feasibility of manufacturing glazed porcelain tiles with a more environmentally friendly manufacturing process, by reducing water and thermal energy consumption. The process studied in this paper is dry milling in a pendulum mill, with subsequent granulation (in order to obtain a press powder with similar flowability to that of spraydried powders. The different morphology of the new granulate with respect to the standard spray-dried granulate modifies the microstructure of the green compacts and thus, their behaviour and fired tile properties. In order to obtain porcelain tiles with the required properties (water absorption, mechanical strength,… changes have been made in the raw materials mixture and in the processing variables. Finally, porcelain tiles measuring 50x50 cm have been manufactured at industrial scale with the new granulate using a conventional firing cycle, obtaining quality levels identical to those provided by the spray-dried granulate. These results open the possibility of preparing porcelain tile body compositions through a manufacturing process alternative to the standard one, more environmentally friendly and with lower costs.

    En el presente trabajo se ha estudiado la viabilidad de fabricar gres porcelánico esmaltado utilizando un sistema de preparación de la composición del soporte más respetuoso con el medio ambiente, lo que implica una reducción importante de los consumos de agua y de energía térmica. El proceso que se estudia en el presente trabajo es el consistente en la molienda vía seca en molino pendular y en la posterior granulación (para obtener un polvo de prensas con fluidez similar a la de los polvos atomizados. La distinta morfología de los nuevos gránulos obtenidos respecto al polvo atomizado actual, modifica la microestuctura en crudo de las piezas y, con ello, el comportamiento y propiedades finales de las baldosas obtenidas. Por ello, ha sido necesario

  15. DEVELOPMENT OF A FABRICATION PROCESS FOR SOL-GEL/METAL HYDRIDE COMPOSITE GRANULES

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, E; Eric Frickey, E; Leung Heung, L

    2004-02-23

    An external gelation process was developed to produce spherical granules that contain metal hydride particles in a sol-gel matrix. Dimensionally stable granules containing metal hydrides are needed for applications such as hydrogen separation and hydrogen purification that require columns containing metal hydrides. Gases must readily flow through the metal hydride beds in the columns. Metal hydrides reversibly absorb and desorb hydrogen and hydrogen isotopes. This is accompanied by significant volume changes that cause the metal hydride to break apart or decrepitate. Repeated cycling results in very fine metal hydride particles that are difficult to handle and contain. Fine particles tend to settle and pack making it more difficult to flow gases through a metal hydride bed. Furthermore, the metal hydrides can exert a significant force on the containment vessel as they expand. These problems associated with metal hydrides can be eliminated with the granulation process described in this report. Small agglomerates of metal hydride particles and abietic acid (a pore former) were produced and dispersed in a colloidal silica/water suspension to form the feed slurry. Fumed silica was added to increase the viscosity of the feed slurry which helped to keep the agglomerates in suspension. Drops of the feed slurry were injected into a 27-foot tall column of hot ({approx}70 C), medium viscosity ({approx}3000 centistokes) silicone oil. Water was slowly evaporated from the drops as they settled. The drops gelled and eventually solidified to form spherical granules. This process is referred to as external gelation. Testing was completed to optimize the design of the column, the feed system, the feed slurry composition, and the operating parameters of the column. The critical process parameters can be controlled resulting in a reproducible fabrication technique. The residual silicone oil on the surface of the granules was removed by washing in mineral spirits. The granules were

  16. In-depth experimental analysis of pharmaceutical twin-screw wet granulation in view of detailed process understanding.

    Science.gov (United States)

    Verstraeten, Maxim; Van Hauwermeiren, Daan; Lee, Kai; Turnbull, Neil; Wilsdon, David; Am Ende, Mary; Doshi, Pankaj; Vervaet, Chris; Brouckaert, Davinia; Mortier, Séverine T F C; Nopens, Ingmar; Beer, Thomas De

    2017-08-30

    Twin-screw wet granulation is gaining increasing interest within the pharmaceutical industry for the continuous manufacturing of solid oral dosage forms. However, limited prior fundamental physical understanding has been generated relating to the granule formation mechanisms and kinetics along the internal compartmental length of a twin-screw granulator barrel, and about how process settings, barrel screw configuration and formulation properties such as particle size, density and surface properties influence these mechanisms. One of the main reasons for this limited understanding is that experimental data is generally only collected at the exit of the twin-screw granulator barrel although the granule formation occurs spatially along the internal length of the barrel. The purpose of this study is to analyze the twin-screw wet granulation process using both hydrophilic and hydrophobic formulations, manufactured under different process settings such as liquid-to-solid ratio, mass throughput and screw speed, in such a way that the mechanisms occurring in the individual granulator barrel compartments (i.e., the wetting and different conveying and kneading compartments) and their impact upon granule formation are understood. To achieve this, a unique experimental setup was developed allowing granule characteristic data-collection such as size, shape, liquid and porosity distribution at the different compartments along the length of the granulator barrel. Moreover, granule characteristic information per granule size class was determined. The experimental results indicated that liquid-to-solid ratio is the most important factor dictating the formation of the granules and their corresponding properties, by regulating the degree of aggregation and breakage in the different compartments along the internal length of the twin-screw granulator barrel. Collecting appropriate and detailed experimental data about granule formation along the internal length of the granulator barrel

  17. Manufacture of slow-release matrix granules by wet granulation with an aqueous dispersion of quaternary poly(meth)acrylates in the fluidized bed.

    Science.gov (United States)

    Radtke, Guido; Knop, Klaus; Lippold, Bernhard C

    2002-11-01

    Slow-release matrix granules were manufactured in the fluidized bed using an aqueous dispersion of quaternary poly(meth)acrylates (Eudragit RS 30 D) as binder for granulation. A factorial design was carried out to investigate the influence of the following parameters, spraying rate, applied polymer amount, and inlet air temperature, on various granule properties. Prerequisites for a slow release of the model drug theophylline are high spraying rate, high amount of polymer, and low inlet air temperature. No considerable decrease of the drug release rate can be achieved without a subsequent curing of the dry granules. A clear correlation exists between the moisture content of the fluidized bed, indicated by the terminal moisture content (TMC), and the mean dissolution time for 80% of the drug (MDT80).

  18. The use of rheology to elucidate the granulation mechanisms of a miscible and immiscible system during continuous twin-screw melt granulation.

    Science.gov (United States)

    Monteyne, Tinne; Heeze, Liza; Mortier, Séverine Thérèse F C; Oldörp, Klaus; Nopens, Ingmar; Remon, Jean-Paul; Vervaet, Chris; De Beer, Thomas

    2016-08-20

    Twin-screw hot melt granulation (TS HMG) is a valuable, but still unexplored alternative to granulate temperature and moisture sensitive drugs in a continuous way. Recently, the material behavior of an immiscible drug-binder blend during TS HMG was unraveled by using a rheometer and differential scanning calorimetry (DSC). Additionally, vibrational spectroscopic techniques proved the link between TS HMG and rheology since equal interactions at molecular level did occur in both processes. This allowed to use a rheometer to gain knowledge of the material behavior during hot melt processing of an immiscible drug-binder blend. However, miscibility of a drug-binder formulation and drug-binder interactions appear to influence the rheological properties and, hence conceivably also the granulation mechanism. The aim of this research was to examine if the TS HMG process of a miscible formulation system is comparable with the mechanism of an immiscible system and to evaluate whether rheology still serves as a useful tool to understand and optimize the hot melt granulation (HMG) process. The executed research (thermal analysis, rheological parameters and spectroscopic data) demonstrated the occurrence of a high and broad tan(δ) curve without a loss peak during the rheological temperature ramp which implies a higher material deformability without movement of the softened single polymer chains. Spectroscopic analysis revealed drug-polymer interactions which constrain the polymer to flow independently. As a result, the binder distribution step, which generally follows the immersion step, was hindered. This insight assisted the understanding of the granule properties. Inhomogeneous granules were produced due to large initial nuclei or adhesion of multiple smaller nuclei. Consequently, a higher granulation temperature was required in order to get the binder more homogeneously distributed within the granules. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Investigating the Properties of Granulation in the Red Giants Observed by Kepler

    DEFF Research Database (Denmark)

    Mathur, S.; Hekker, S.; Trampedach, R.

    2012-01-01

    More than 1000 red giants have been observed by NASA/Kepler mission during a nearly continuous period of ˜ 13 months. The resulting high-frequency resolution (<0.03 μHz) allows us to study the granulation parameters of these stars. The granulation pattern results from the convection motions leadi...

  20. The Impact of Granule Density on Tabletting and Pharmaceutical Product Performance.

    Science.gov (United States)

    van den Ban, Sander; Goodwin, Daniel J

    2017-05-01

    The impact of granule densification in high-shear wet granulation on tabletting and product performance was investigated, at pharmaceutical production scale. Product performance criteria need to be balanced with the need to deliver manufacturability criteria to assure robust industrial scale tablet manufacturing processes. A Quality by Design approach was used to determine in-process control specifications for tabletting, propose a design space for disintegration and dissolution, and to understand the permitted operating limits and required controls for an industrial tabletting process. Granules of varying density (filling density) were made by varying water amount added, spray rate, and wet massing time in a design of experiment (DoE) approach. Granules were compressed into tablets to a range of thicknesses to obtain tablets of varying breaking force. Disintegration and dissolution performance was evaluated for the tablets made. The impact of granule filling density on tabletting was rationalised with compressibility, tabletability and compactibility. Tabletting and product performance criteria provided competing requirements for porosity. An increase in granule filling density impacted tabletability and compactability and limited the ability to achieve tablets of adequate mechanical strength. An increase in tablet solid fraction (decreased porosity) impacted disintegration and dissolution. An attribute-based design space for disintegration and dissolution was specified to achieve both product performance and manufacturability. The method of granulation and resulting granule filling density is a key design consideration to achieve both product performance and manufacturability required for modern industrial scale pharmaceutical product manufacture and distribution.