Impairment of Cellulose Synthases Required for Arabidopsis Secondary Cell Wall Formation Enhances Disease Resistance[W

Science.gov (United States)

Hernández-Blanco, Camilo; Feng, Dong Xin; Hu, Jian; Sánchez-Vallet, Andrea; Deslandes, Laurent; Llorente, Francisco; Berrocal-Lobo, Marta; Keller, Harald; Barlet, Xavier; Sánchez-Rodríguez, Clara; Anderson, Lisa K.; Somerville, Shauna; Marco, Yves; Molina, Antonio

2007-01-01

Cellulose is synthesized by cellulose synthases (CESAs) contained in plasma membrane–localized complexes. In Arabidopsis thaliana, three types of CESA subunits (CESA4/IRREGULAR XYLEM5 [IRX5], CESA7/IRX3, and CESA8/IRX1) are required for secondary cell wall formation. We report that mutations in these proteins conferred enhanced resistance to the soil-borne bacterium Ralstonia solanacearum and the necrotrophic fungus Plectosphaerella cucumerina. By contrast, susceptibility to these pathogens was not altered in cell wall mutants of primary wall CESA subunits (CESA1, CESA3/ISOXABEN RESISTANT1 [IXR1], and CESA6/IXR2) or POWDERY MILDEW–RESISTANT5 (PMR5) and PMR6 genes. Double mutants indicated that irx-mediated resistance was independent of salicylic acid, ethylene, and jasmonate signaling. Comparative transcriptomic analyses identified a set of common irx upregulated genes, including a number of abscisic acid (ABA)–responsive, defense-related genes encoding antibiotic peptides and enzymes involved in the synthesis and activation of antimicrobial secondary metabolites. These data as well as the increased susceptibility of ABA mutants (abi1-1, abi2-1, and aba1-6) to R. solanacearum support a direct role of ABA in resistance to this pathogen. Our results also indicate that alteration of secondary cell wall integrity by inhibiting cellulose synthesis leads to specific activation of novel defense pathways that contribute to the generation of an antimicrobial-enriched environment hostile to pathogens. PMID:17351116

Characterization of Cellulose Synthesis in Plant Cells

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Maleki, Samaneh Sadat; Mohammadi, Kourosh; Ji, Kong-shu

2016-01-01

Cellulose is the most significant structural component of plant cell wall. Cellulose, polysaccharide containing repeated unbranched β (1-4) D-glucose units, is synthesized at the plasma membrane by the cellulose synthase complex (CSC) from bacteria to plants. The CSC is involved in biosynthesis of cellulose microfibrils containing 18 cellulose synthase (CesA) proteins. Macrofibrils can be formed with side by side arrangement of microfibrils. In addition, beside CesA, various proteins like the KORRIGAN, sucrose synthase, cytoskeletal components, and COBRA-like proteins have been involved in cellulose biosynthesis. Understanding the mechanisms of cellulose biosynthesis is of great importance not only for improving wood production in economically important forest trees to mankind but also for plant development. This review article covers the current knowledge about the cellulose biosynthesis-related gene family. PMID:27314060

Characterization of Cellulose Synthesis in Plant Cells

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Samaneh Sadat Maleki

2016-01-01

Full Text Available Cellulose is the most significant structural component of plant cell wall. Cellulose, polysaccharide containing repeated unbranched β (1-4 D-glucose units, is synthesized at the plasma membrane by the cellulose synthase complex (CSC from bacteria to plants. The CSC is involved in biosynthesis of cellulose microfibrils containing 18 cellulose synthase (CesA proteins. Macrofibrils can be formed with side by side arrangement of microfibrils. In addition, beside CesA, various proteins like the KORRIGAN, sucrose synthase, cytoskeletal components, and COBRA-like proteins have been involved in cellulose biosynthesis. Understanding the mechanisms of cellulose biosynthesis is of great importance not only for improving wood production in economically important forest trees to mankind but also for plant development. This review article covers the current knowledge about the cellulose biosynthesis-related gene family.

Expression analysis of cellulose synthase and main cytoskeletal protein genes in flax (Linum usitatissimum L.).

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Galinousky, Dmitry; Padvitski, Tsimafei; Bayer, Galina; Pirko, Yaroslav; Pydiura, Nikolay; Anisimova, Natallia; Nikitinskaya, Tatyana; Khotyleva, Liubov; Yemets, Alla; Kilchevsky, Aleksandr; Blume, Yaroslav

2017-08-09

Fiber flax is an important source of natural fiber and a comprehensive model for the plant fiber biogenesis studies. Cellulose-synthase (CesA) and cytoskeletal genes are known to be important for the cell wall biogenesis in general and for the biogenesis of flax fibers in particular. Currently, knowledge about activity of these genes during the plant growth is limited. In this study, we have investigated flax fiber biogenesis by measuring expression of CesA and cytoskeletal genes at two stages of the flax development (seedlings and stems at the rapid growth stage) in several flax subspecies (elongatum, mediterraneum, crepitans). RT-qPCR has been used to quantify the expression of LusСesA1, LusСesA4, LusСesA7, LusСesA6, Actin, and α-Tubulin genes in plant samples. We report that CesA genes responsible for the secondary cell wall synthesis (LusCesA4, LusCesA7) have different expression pattern compared with CesA genes responsible for the primary cell wall synthesis (LusCesA1, LusCesA6): an average expression of LusCesA4 and LusCesA7 genes is relatively high in seedlings and further increases in stems at the rapid growth stage, whereas an average expression of LusCesA1 and LusCesA6 genes decreases. Interestingly, LusCesA1 is the only studied gene with different expression dynamics between the flax subspecies: its expression decreases by 5.2-10.7 folds in elongatum and mediterraneum but does not change in crepitans subspecies when the rapid growth stage and seedlings are compared. The expression of cytoskeleton genes (coding actin and α-tubulin) is relatively stable and significantly higher than the expression of cellulose-synthase genes in all the studied samples. © 2017 International Federation for Cell Biology.

Effect of late planting and shading on cellulose synthesis during cotton fiber secondary wall development.

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Ji Chen

Full Text Available Cotton-rapeseed or cotton-wheat double cropping systems are popular in the Yangtze River Valley and Yellow River Valley of China. Due to the competition of temperature and light resources during the growing season of double cropping system, cotton is generally late-germinating and late-maturing and has to suffer from the coupling of declining temperature and low light especially in the late growth stage. In this study, late planting (LP and shading were used to fit the coupling stress, and the coupling effect on fiber cellulose synthesis was investigated. Two cotton (Gossypium hirsutum L. cultivars were grown in the field in 2010 and 2011 at three planting dates (25 April, 25 May and 10 June each with three shading levels (normal light, declined 20% and 40% PAR. Mean daily minimum temperature was the primary environmental factor affected by LP. The coupling of LP and shading (decreased cellulose content by 7.8%-25.5% produced more severe impacts on cellulose synthesis than either stress alone, and the effect of LP (decreased cellulose content by 6.7%-20.9% was greater than shading (decreased cellulose content by 0.7%-5.6%. The coupling of LP and shading hindered the flux from sucrose to cellulose by affecting the activities of related cellulose synthesis enzymes. Fiber cellulose synthase genes expression were delayed under not only LP but shading, and the coupling of LP and shading markedly postponed and even restrained its expression. The decline of sucrose-phosphate synthase activity and its peak delay may cause cellulose synthesis being more sensitive to the coupling stress during the later stage of fiber secondary wall development (38-45 days post-anthesis. The sensitive difference of cellulose synthesis between two cultivars in response to the coupling of LP and shading may be mainly determined by the sensitiveness of invertase, sucrose-phosphate synthase and cellulose synthase.

Unidirectional Movement of Cellulose Synthase Complexes in Arabidopsis Seed Coat Epidermal Cells Deposit Cellulose Involved in Mucilage Extrusion, Adherence, and Ray Formation1[OPEN

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Lam, Patricia; Young, Robin; DeBolt, Seth

2015-01-01

CELLULOSE SYNTHASE5 (CESA5) synthesizes cellulose necessary for seed mucilage adherence to seed coat epidermal cells of Arabidopsis (Arabidopsis thaliana). The involvement of additional CESA proteins in this process and details concerning the manner in which cellulose is deposited in the mucilage pocket are unknown. Here, we show that both CESA3 and CESA10 are highly expressed in this cell type at the time of mucilage synthesis and localize to the plasma membrane adjacent to the mucilage pocket. The isoxaben resistant1-1 and isoxaben resistant1-2 mutants affecting CESA3 show defects consistent with altered mucilage cellulose biosynthesis. CESA3 can interact with CESA5 in vitro, and green fluorescent protein-tagged CESA5, CESA3, and CESA10 proteins move in a linear, unidirectional fashion around the cytoplasmic column of the cell, parallel with the surface of the seed, in a pattern similar to that of cortical microtubules. Consistent with this movement, cytological evidence suggests that the mucilage is coiled around the columella and unwinds during mucilage extrusion to form a linear ray. Mutations in CESA5 and CESA3 affect the speed of mucilage extrusion and mucilage adherence. These findings imply that cellulose fibrils are synthesized in an ordered helical array around the columella, providing a distinct structure to the mucilage that is important for both mucilage extrusion and adherence. PMID:25926481

A Molecular Description of Cellulose Biosynthesis

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McNamara, Joshua T.; Morgan, Jacob L.W.; Zimmer, Jochen

2016-01-01

Cellulose is the most abundant biopolymer on Earth, and certain organisms from bacteria to plants and animals synthesize cellulose as an extracellular polymer for various biological functions. Humans have used cellulose for millennia as a material and an energy source, and the advent of a lignocellulosic fuel industry will elevate it to the primary carbon source for the burgeoning renewable energy sector. Despite the biological and societal importance of cellulose, the molecular mechanism by which it is synthesized is now only beginning to emerge. On the basis of recent advances in structural and molecular biology on bacterial cellulose synthases, we review emerging concepts of how the enzymes polymerize glucose molecules, how the nascent polymer is transported across the plasma membrane, and how bacterial cellulose biosynthesis is regulated during biofilm formation. Additionally, we review evolutionary commonalities and differences between cellulose synthases that modulate the nature of the cellulose product formed. PMID:26034894

A Genome-Wide Association Study for Culm Cellulose Content in Barley Reveals Candidate Genes Co-Expressed with Members of the CELLULOSE SYNTHASE A Gene Family

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Houston, Kelly; Burton, Rachel A.; Sznajder, Beata; Rafalski, Antoni J.; Dhugga, Kanwarpal S.; Mather, Diane E.; Taylor, Jillian; Steffenson, Brian J.; Waugh, Robbie; Fincher, Geoffrey B.

2015-01-01

Cellulose is a fundamentally important component of cell walls of higher plants. It provides a scaffold that allows the development and growth of the plant to occur in an ordered fashion. Cellulose also provides mechanical strength, which is crucial for both normal development and to enable the plant to withstand both abiotic and biotic stresses. We quantified the cellulose concentration in the culm of 288 two – rowed and 288 six – rowed spring type barley accessions that were part of the USDA funded barley Coordinated Agricultural Project (CAP) program in the USA. When the population structure of these accessions was analysed we identified six distinct populations, four of which we considered to be comprised of a sufficient number of accessions to be suitable for genome-wide association studies (GWAS). These lines had been genotyped with 3072 SNPs so we combined the trait and genetic data to carry out GWAS. The analysis allowed us to identify regions of the genome containing significant associations between molecular markers and cellulose concentration data, including one region cross-validated in multiple populations. To identify candidate genes we assembled the gene content of these regions and used these to query a comprehensive RNA-seq based gene expression atlas. This provided us with gene annotations and associated expression data across multiple tissues, which allowed us to formulate a supported list of candidate genes that regulate cellulose biosynthesis. Several regions identified by our analysis contain genes that are co-expressed with CELLULOSE SYNTHASE A (HvCesA) across a range of tissues and developmental stages. These genes are involved in both primary and secondary cell wall development. In addition, genes that have been previously linked with cellulose synthesis by biochemical methods, such as HvCOBRA, a gene of unknown function, were also associated with cellulose levels in the association panel. Our analyses provide new insights into the

Disruption of ATCSLD5 results in reduced growth, reduced xylan and homogalacturonan synthase activity and altered xylan occurrence in Arabidopsis

DEFF Research Database (Denmark)

Bernal Giraldo, Adriana Jimena; Jensen, Jacob Krüger; Harholt, Jesper

2007-01-01

Members of a large family of cellulose synthase-like genes (CSLs) are predicted to encode glycosyl transferases (GTs) involved in the biosynthesis of plant cell walls. The CSLA and CSLF families are known to contain mannan and glucan synthases, respectively, but the products of other CSLs...... are unknown. Here we report the effects of disrupting ATCSLD5 expression in Arabidopsis. Both stem and root growth were significantly reduced in ATCSLD5 knock-out plants, and these plants also had increased susceptibility to the cellulose synthase inhibitor isoxaben. Antibody and carbohydrate-binding module...

High polymorphism in Est-SSR loci for cellulose synthase and β-amylase of sugarcane varieties (Saccharum spp.) used by the industrial sector for ethanol production.

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Augusto, Raphael; Maranho, Rone Charles; Mangolin, Claudete Aparecida; Pires da Silva Machado, Maria de Fátima

2015-01-01

High and low polymorphisms in simple sequence repeats of expressed sequence tag (EST-SSR) for specific proteins and enzymes, such as β-amylase, cellulose synthase, xyloglucan endotransglucosylase, fructose 1,6-bisphosphate aldolase, and fructose 1,6-bisphosphatase, were used to illustrate the genetic divergence within and between varieties of sugarcane (Saccharum spp.) and to guide the technological paths to optimize ethanol production from lignocellulose biomass. The varieties RB72454, RB867515, RB92579, and SP813250 on the second stage of cutting, all grown in the state of Paraná (PR), and the varieties RB92579 and SP813250 cultured in the PR state and in Northeastern Brazil, state of Pernambuco (PE), were analyzed using five EST-SSR primers for EstC66, EstC67, EstC68, EstC69, and EstC91 loci. Genetic divergence was evident in the EstC67 and EstC69 loci for β-amylase and cellulose synthase, respectively, among the four sugarcane varieties. An extremely high level of genetic differentiation was also detected in the EstC67 locus from the RB82579 and SP813250 varieties cultured in the PR and PE states. High polymorphism in SSR of the cellulose synthase locus may explain the high variability of substrates used in pretreatment and enzymatic hydrolysis processes, which has been an obstacle to effective industrial adaptations.

Bacterial cellulose biosynthesis: diversity of operons, subunits, products and functions

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Römling, Ute; Galperin, Michael Y.

2015-01-01

Summary Recent studies of bacterial cellulose biosynthesis, including structural characterization of a functional cellulose synthase complex, provided the first mechanistic insight into this fascinating process. In most studied bacteria, just two subunits, BcsA and BcsB, are necessary and sufficient for the formation of the polysaccharide chain in vitro. Other subunits – which differ among various taxa – affect the enzymatic activity and product yield in vivo by modulating expression of biosynthesis apparatus, export of the nascent β-D-glucan polymer to the cell surface, and the organization of cellulose fibers into a higher-order structure. These auxiliary subunits play key roles in determining the quantity and structure of the resulting biofilm, which is particularly important for interactions of bacteria with higher organisms that lead to rhizosphere colonization and modulate virulence of cellulose-producing bacterial pathogens inside and outside of host cells. Here we review the organization of four principal types of cellulose synthase operons found in various bacterial genomes, identify additional bcs genes that encode likely components of the cellulose biosynthesis and secretion machinery, and propose a unified nomenclature for these genes and subunits. We also discuss the role of cellulose as a key component of biofilms formed by a variety of free-living and pathogenic bacteria and, for the latter, in the choice between acute infection and persistence in the host. PMID:26077867

Chitinase-like (CTL) and cellulose synthase (CESA) gene expression in gelatinous-type cellulosic walls of flax (Linum usitatissimum L.) bast fibers.

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Mokshina, Natalia; Gorshkova, Tatyana; Deyholos, Michael K

2014-01-01

Plant chitinases (EC 3.2.1.14) and chitinase-like (CTL) proteins have diverse functions including cell wall biosynthesis and disease resistance. We analyzed the expression of 34 chitinase and chitinase-like genes of flax (collectively referred to as LusCTLs), belonging to glycoside hydrolase family 19 (GH19). Analysis of the transcript expression patterns of LusCTLs in the stem and other tissues identified three transcripts (LusCTL19, LusCTL20, LusCTL21) that were highly enriched in developing bast fibers, which form cellulose-rich gelatinous-type cell walls. The same three genes had low relative expression in tissues with primary cell walls and in xylem, which forms a xylan type of secondary cell wall. Phylogenetic analysis of the LusCTLs identified a flax-specific sub-group that was not represented in any of other genomes queried. To provide further context for the gene expression analysis, we also conducted phylogenetic and expression analysis of the cellulose synthase (CESA) family genes of flax, and found that expression of secondary wall-type LusCESAs (LusCESA4, LusCESA7 and LusCESA8) was correlated with the expression of two LusCTLs (LusCTL1, LusCTL2) that were the most highly enriched in xylem. The expression of LusCTL19, LusCTL20, and LusCTL21 was not correlated with that of any CESA subgroup. These results defined a distinct type of CTLs that may have novel functions specific to the development of the gelatinous (G-type) cellulosic walls.

Cellulose microfibril crystallinity is reduced by mutating C-terminal transmembrane region residues CESA1{sup A903V} and CESA3{sup T942I} of cellulose synthase

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Harris, Darby; Corbin, Kendall; Wang, Tuo; Gutierrez, Ryan; Bertolo, Ana; Petti, Caroalberto; Smilgies, Detlef-M; Estevez, Jose Manuel; Bonetta, Dario; Urbanowicz, Breeanna; Ehrhardt, David; Somerville, Chris; Rose, Jocelyn; Hong, Mei; DeBolt, Seth

2012-01-08

The mechanisms underlying the biosynthesis of cellulose in plants are complex and still poorly understood. A central question concerns the mechanism of microfibril structure and how this is linked to the catalytic polymerization action of cellulose synthase (CESA). Furthermore, it remains unclear whether modification of cellulose microfibril structure can be achieved genetically, which could be transformative in a bio-based economy. To explore these processes in planta, we developed a chemical genetic toolbox of pharmacological inhibitors and corresponding resistance-conferring point mutations in the C-terminal transmembrane domain region of CESA1{sup A903V} and CESA3{sup T942I} in Arabidopsis thaliana. Using {sup 13}C solid-state nuclear magnetic resonance spectroscopy and X-ray diffraction, we show that the cellulose microfibrils displayed reduced width and an additional cellulose C4 peak indicative of a degree of crystallinity that is intermediate between the surface and interior glucans of wild type, suggesting a difference in glucan chain association during microfibril formation. Consistent with measurements of lower microfibril crystallinity, cellulose extracts from mutated CESA1{sup A903V} and CESA3{sup T942I} displayed greater saccharification efficiency than wild type. Using live-cell imaging to track fluorescently labeled CESA, we found that these mutants show increased CESA velocities in the plasma membrane, an indication of increased polymerization rate. Collectively, these data suggest that CESA1{sup A903V} and CESA3{sup T942I} have modified microfibril structure in terms of crystallinity and suggest that in plants, as in bacteria, crystallization biophysically limits polymerization.

[Cellulose synthase genes that control the fiber formation of flax (Linum usitatissimum L.)].

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Galinovskiĭ, D V; Anisimova, N V; Raĭskiĭ, A P; Leont'ev, V N; Titok, V V; Hotyleva, L V

2014-01-01

Four cellulose synthase genes were identified by analysis of their class-specific regions (CSRII) in plants of fiber flax during the "rapid growth" stage. These genes were designated as LusCesA1, LusCesA4, LusCesA7 and LusCesA9. LusCesA4, LusCesA7, and LusCesA9 genes were expressed in the stem; LusCesA1 and LusCesA4 genes were expressed in the apex part of plants, and the LusCesA4 gene was expressed in the leaves of fiber flax. The expression of the LusCesA7 and LusCesA9 genes was specific to the stems of fiber flax. These genes may influence the quality of the flax fiber.

Glycogen synthase activation by sugars in isolated hepatocytes.

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Ciudad, C J; Carabaza, A; Bosch, F; Gòmez I Foix, A M; Guinovart, J J

1988-07-01

We have investigated the activation by sugars of glycogen synthase in relation to (i) phosphorylase a activity and (ii) changes in the intracellular concentration of glucose 6-phosphate and adenine nucleotides. All the sugars tested in this work present the common denominator of activating glycogen synthase. On the other hand, phosphorylase a activity is decreased by mannose and glucose, unchanged by galactose and xylitol, and increased by tagatose, glyceraldehyde, and fructose. Dihydroxyacetone exerts a biphasic effect on phosphorylase. These findings provide additional evidence proving that glycogen synthase can be activated regardless of the levels of phosphorylase a, clearly establishing that a nonsequential mechanism for the activation of glycogen synthase occurs in liver cells. The glycogen synthase activation state is related to the concentrations of glucose 6-phosphate and adenine nucleotides. In this respect, tagatose, glyceraldehyde, and fructose deplete ATP and increase AMP contents, whereas glucose, mannose, galactose, xylitol, and dihydroxyacetone do not alter the concentration of these nucleotides. In addition, all these sugars, except glyceraldehyde, increase the intracellular content of glucose 6-phosphate. The activation of glycogen synthase by sugars is reflected in decreases on both kinetic constants of the enzyme, M0.5 (for glucose 6-phosphate) and S0.5 (for UDP-glucose). We propose that hepatocyte glycogen synthase is activated by monosaccharides by a mechanism triggered by changes in glucose 6-phosphate and adenine nucleotide concentrations which have been described to modify glycogen synthase phosphatase activity. This mechanism represents a metabolite control of the sugar-induced activation of hepatocyte glycogen synthase.

Cellulose microfibril structure: inspirations from plant diversity

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Roberts, A. W.

2018-03-01

Cellulose microfibrils are synthesized at the plasma membrane by cellulose synthase catalytic subunits that associate to form cellulose synthesis complexes. Variation in the organization of these complexes underlies the variation in cellulose microfibril structure among diverse organisms. However, little is known about how the catalytic subunits interact to form complexes with different morphologies. We are using an evolutionary approach to investigate the roles of different catalytic subunit isoforms in organisms that have rosette-type cellulose synthesis complexes.

Functional analyses of cellulose synthase genes in flax (Linum usitatissimum) by virus-induced gene silencing.

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Chantreau, Maxime; Chabbert, Brigitte; Billiard, Sylvain; Hawkins, Simon; Neutelings, Godfrey

2015-12-01

Flax (Linum usitatissimum) bast fibres are located in the stem cortex where they play an important role in mechanical support. They contain high amounts of cellulose and so are used for linen textiles and in the composite industry. In this study, we screened the annotated flax genome and identified 14 distinct cellulose synthase (CESA) genes using orthologous sequences previously identified. Transcriptomics of 'primary cell wall' and 'secondary cell wall' flax CESA genes showed that some were preferentially expressed in different organs and stem tissues providing clues as to their biological role(s) in planta. The development for the first time in flax of a virus-induced gene silencing (VIGS) approach was used to functionally evaluate the biological role of different CESA genes in stem tissues. Quantification of transcript accumulation showed that in many cases, silencing not only affected targeted CESA clades, but also had an impact on other CESA genes. Whatever the targeted clade, inactivation by VIGS affected plant growth. In contrast, only clade 1- and clade 6-targeted plants showed modifications in outer-stem tissue organization and secondary cell wall formation. In these plants, bast fibre number and structure were severely impacted, suggesting that the targeted genes may play an important role in the establishment of the fibre cell wall. Our results provide new fundamental information about cellulose biosynthesis in flax that should facilitate future plant improvement/engineering. © 2015 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

Isolation and Characterization of Two Cellulose Morphology Mutants of Gluconacetobacter hansenii ATCC23769 Producing Cellulose with Lower Crystallinity

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Deng, Ying; Nagachar, Nivedita; Fang, Lin; Luan, Xin; Catchmark, Jeffrey M.; Tien, Ming; Kao, Teh-hui

2015-01-01

Gluconacetobacter hansenii, a Gram-negative bacterium, produces and secrets highly crystalline cellulose into growth medium, and has long been used as a model system for studying cellulose synthesis in higher plants. Cellulose synthesis involves the formation of β-1,4 glucan chains via the polymerization of glucose units by a multi-enzyme cellulose synthase complex (CSC). These glucan chains assemble into ordered structures including crystalline microfibrils. AcsA is the catalytic subunit of the cellulose synthase enzymes in the CSC, and AcsC is required for the secretion of cellulose. However, little is known about other proteins required for the assembly of crystalline cellulose. To address this question, we visually examined cellulose pellicles formed in growth media of 763 individual colonies of G. hansenii generated via Tn5 transposon insertion mutagenesis, and identified 85 that produced cellulose with altered morphologies. X-ray diffraction analysis of these 85 mutants identified two that produced cellulose with significantly lower crystallinity than wild type. The gene disrupted in one of these two mutants encoded a lysine decarboxylase and that in the other encoded an alanine racemase. Solid-state NMR analysis revealed that cellulose produced by these two mutants contained increased amounts of non-crystalline cellulose and monosaccharides associated with non-cellulosic polysaccharides as compared to the wild type. Monosaccharide analysis detected higher percentages of galactose and mannose in cellulose produced by both mutants. Field emission scanning electron microscopy showed that cellulose produced by the mutants was unevenly distributed, with some regions appearing to contain deposition of non-cellulosic polysaccharides; however, the width of the ribbon was comparable to that of normal cellulose. As both lysine decarboxylase and alanine racemase are required for the integrity of peptidoglycan, we propose a model for the role of peptidoglycan in the

Isolation and characterization of two cellulose morphology mutants of Gluconacetobacter hansenii ATCC23769 producing cellulose with lower crystallinity.

Directory of Open Access Journals (Sweden)

Ying Deng

Full Text Available Gluconacetobacter hansenii, a Gram-negative bacterium, produces and secrets highly crystalline cellulose into growth medium, and has long been used as a model system for studying cellulose synthesis in higher plants. Cellulose synthesis involves the formation of β-1,4 glucan chains via the polymerization of glucose units by a multi-enzyme cellulose synthase complex (CSC. These glucan chains assemble into ordered structures including crystalline microfibrils. AcsA is the catalytic subunit of the cellulose synthase enzymes in the CSC, and AcsC is required for the secretion of cellulose. However, little is known about other proteins required for the assembly of crystalline cellulose. To address this question, we visually examined cellulose pellicles formed in growth media of 763 individual colonies of G. hansenii generated via Tn5 transposon insertion mutagenesis, and identified 85 that produced cellulose with altered morphologies. X-ray diffraction analysis of these 85 mutants identified two that produced cellulose with significantly lower crystallinity than wild type. The gene disrupted in one of these two mutants encoded a lysine decarboxylase and that in the other encoded an alanine racemase. Solid-state NMR analysis revealed that cellulose produced by these two mutants contained increased amounts of non-crystalline cellulose and monosaccharides associated with non-cellulosic polysaccharides as compared to the wild type. Monosaccharide analysis detected higher percentages of galactose and mannose in cellulose produced by both mutants. Field emission scanning electron microscopy showed that cellulose produced by the mutants was unevenly distributed, with some regions appearing to contain deposition of non-cellulosic polysaccharides; however, the width of the ribbon was comparable to that of normal cellulose. As both lysine decarboxylase and alanine racemase are required for the integrity of peptidoglycan, we propose a model for the role of

Cellulose synthesis genes CESA6 and CSI1 are important for salt stress tolerance in Arabidopsis.

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Zhang, Shuang-Shuang; Sun, Le; Dong, Xinran; Lu, Sun-Jie; Tian, Weidong; Liu, Jian-Xiang

2016-07-01

Two salt hypersensitive mutants she1 and she2 were identified through genetic screening. SHE1 encodes a cellulose synthase CESA6 while SHE2 encodes a cellulose synthase-interactive protein CSI1. Both of them are involved in cellulose deposition. Our results demonstrated that the sustained cellulose synthesis is important for salt stress tolerance in Arabidopsis. © 2015 Institute of Botany, Chinese Academy of Sciences.

Cyanobacterial cellulose synthesis in the light of the photanol concept

NARCIS (Netherlands)

Schuurmans, R.M.; Matthijs, H.C.P.; Stal, L.J.; Hellingwerf, K.J.; Sharma, N.K.; Rai, A.K.; Stal, L.J.

2014-01-01

The detailed knowledge already available about cellulose synthases and their regulation, plus emerging insights into the process of cellulose secretion in cyanobacteria make cellulose an attractive polymer for the application of the photanol concept in an economically viable production process. By

Regulation of cellulose synthesis in response to stress.

Science.gov (United States)

Kesten, Christopher; Menna, Alexandra; Sánchez-Rodríguez, Clara

2017-12-01

The cell wall is a complex polysaccharide network that provides stability and protection to the plant and is one of the first layers of biotic and abiotic stimuli perception. A controlled remodeling of the primary cell wall is essential for the plant to adapt its growth to environmental stresses. Cellulose, the main component of plant cell walls is synthesized by plasma membrane-localized cellulose synthases moving along cortical microtubule tracks. Recent advancements demonstrate a tight regulation of cellulose synthesis at the primary cell wall by phytohormone networks. Stress-induced perturbations at the cell wall that modify cellulose synthesis and microtubule arrangement activate similar phytohormone-based stress response pathways. The integration of stress perception at the primary cell wall and downstream responses are likely to be tightly regulated by phytohormone signaling pathways in the context of cellulose synthesis and microtubule arrangement. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Transgene silencing of sucrose synthase in alfalfa (Medicago sativa L.) stem vascular tissue suggests a role for invertase in cell wall cellulose synthesis.

Science.gov (United States)

Samac, Deborah A; Bucciarelli, Bruna; Miller, Susan S; Yang, S Samuel; O'Rourke, Jamie A; Shin, Sanghyun; Vance, Carroll P

2015-12-01

Alfalfa (Medicago sativa L.) is a widely adapted perennial forage crop that has high biomass production potential. Enhanced cellulose content in alfalfa stems would increase the value of the crop as a bioenergy feedstock. We examined if increased expression of sucrose synthase (SUS; EC 2.4.1.13) would increase cellulose in stem cell walls. Alfalfa plants were transformed with a truncated alfalfa phosphoenolpyruvate carboxylase gene promoter (PEPC7-P4) fused to an alfalfa nodule-enhanced SUS cDNA (MsSUS1) or the β-glucuronidase (GUS) gene. Strong GUS expression was detected in xylem and phloem indicating that the PEPC7-P4 promoter was active in stem vascular tissue. In contrast to expectations, MsSUS1 transcript accumulation was reduced 75-90 % in alfalfa plants containing the PEPC7-P4::MsSUS1 transgene compared to controls. Enzyme assays indicated that SUS activity in stems of selected down-regulated transformants was reduced by greater than 95 % compared to the controls. Although SUS activity was detected in xylem and phloem of control plants by in situ enzyme assays, plants with the PEPC7-P4::MsSUS1 transgene lacked detectable SUS activity in post-elongation stem (PES) internodes and had very low SUS activity in elongating stem (ES) internodes. Loss of SUS protein in PES internodes of down-regulated lines was confirmed by immunoblots. Down-regulation of SUS expression and activity in stem tissue resulted in no obvious phenotype or significant change in cell wall sugar composition. However, alkaline/neutral (A/N) invertase activity increased in SUS down-regulated lines and high levels of acid invertase activity were observed. In situ enzyme assays of stem tissue showed localization of neutral invertase in vascular tissues of ES and PES internodes. These results suggest that invertases play a primary role in providing glucose for cellulose biosynthesis or compensate for the loss of SUS1 activity in stem vascular tissue.

Characterization of a 1,4-. beta. -D-glucan synthase from Dictyostelium discoideum

Energy Technology Data Exchange (ETDEWEB)

Blanton, R.L.

1992-01-15

Various aspects of research concerning Dictyostelium discoideum are presented. The initial focus of this project was upon: the characterization of potential probes for the cellulose synthase (antibody and nucleic acid), the determination of the cultural induction conditions of cellulose synthesis, the solubilization of the enzyme activity, the development of a non-inhibitory disruption buffer, the generation and isolation of mutant strains deficient in cellulose synthesis, and the development of the capability to determine the degree of polymerization of the in vitro product. I have briefly summarized our most significant findings with only selected data sets being shown in this report in the interest of brevity.

The primary defect in glycogen synthase activity is not based on increased glycogen synthase kinase-3a activity in diabetic myotubes

DEFF Research Database (Denmark)

Gaster, Michael; Brusgaard, Klaus; Handberg, Aa.

2004-01-01

The mechanism responsible for the diminished activation of glycogen synthase (GS) in diabetic myotubes remains unclear, but may involve increased activity and/or expression of glycogen synthase kinase-3 (GSK-3). In myotubes established from type 2 diabetic and healthy control subjects we determined...

Active-site-directed inhibition of 3-hydroxy-3-methylglutaryl coenzyme A synthase by 3-chloropropionyl coenzyme A

International Nuclear Information System (INIS)

Miziorko, H.M.; Behnke, C.E.

1985-01-01

3-Chloropropionyl coenzyme A (3-chloropropionyl-CoA) irreversibly inhibits avian liver 3-hydroxy-3-methylglutaryl-CoA synthase (HMG-CoA synthase). Enzyme inactivation follows pseudo-first-order kinetics and is retarded in the presence of substrates, suggesting that covalent labeling occurs at the active site. A typical rate saturation effect is observed when inactivation kinetics are measured as a function of 3-chloropropionyl-CoA concentration. These data indicate a Ki = 15 microM for the inhibitor and a limiting kinact = 0.31 min-1. [1- 14 C]-3-Chloropropionyl-CoA binds covalently to the enzyme with a stoichiometry (0.7 per site) similar to that measured for acetylation of the enzyme by acetyl-CoA. While the acetylated enzyme formed upon incubation of HMG-CoA synthase with acetyl-CoA is labile to performic acid oxidation, the adduct formed upon 3-chloropropionyl-CoA inactivation is stable to such treatment. Therefore, such an adduct cannot solely involve a thio ester linkage. Exhaustive Pronase digestion of [ 14 C]-3-chloropropionyl-CoA-labeled enzyme produces a radioactive compound which cochromatographs with authentic carboxyethylcysteine using reverse-phase/ion-pairing high-pressure liquid chromatography and both silica and cellulose thin-layer chromatography systems. This suggests that enzyme inactivation is due to alkylation of an active-site cysteine residue

Arabidopsis cortical microtubules position cellulose synthase delivery to the plasma membrane and interact with cellulose synthase trafficking compartments.

NARCIS (Netherlands)

Gutierrez, R.; Lindeboom, J.J.; Paredez, A.R.; Emons, A.M.C.; Ehrhardt, D.W.

2009-01-01

Plant cell morphogenesis relies on the organization and function of two polymer arrays separated by the plasma membrane: the cortical microtubule cytoskeleton and cellulose microfibrils in the cell wall. Studies using in vivo markers confirmed that one function of the cortical microtubule array is

Rice Cellulose SynthaseA8 Plant-Conserved Region Is a Coiled-Coil at the Catalytic Core Entrance

Energy Technology Data Exchange (ETDEWEB)

Rushton, Phillip S.; Olek, Anna T.; Makowski, Lee; Badger, John; Steussy, C. Nicklaus; Carpita, Nicholas C.; Stauffacher, Cynthia V. (NEU); (Purdue)

2016-11-22

The crystallographic structure of a rice (Oryza sativa) cellulose synthase, OsCesA8, plant-conserved region (P-CR), one of two unique domains in the catalytic domain of plant CesAs, was solved to 2.4 Å resolution. Two antiparallel α-helices form a coiled-coil domain linked by a large extended connector loop containing a conserved trio of aromatic residues. The P-CR structure was fit into a molecular envelope for the P-CR domain derived from small-angle X-ray scattering data. The P-CR structure and molecular envelope, combined with a homology-based chain trace of the CesA8 catalytic core, were modeled into a previously determined CesA8 small-angle X-ray scattering molecular envelope to produce a detailed topological model of the CesA8 catalytic domain. The predicted position for the P-CR domain from the molecular docking models places the P-CR connector loop into a hydrophobic pocket of the catalytic core, with the coiled-coil aligned near the entrance of the substrate UDP-glucose into the active site. In this configuration, the P-CR coiled-coil alone is unlikely to regulate substrate access to the active site, but it could interact with other domains of CesA, accessory proteins, or other CesA catalytic domains to control substrate delivery.

Cellulose Synthesis in Agrobacterium tumefaciens

Energy Technology Data Exchange (ETDEWEB)

Alan R. White; Ann G. Matthysse

2004-07-31

We have cloned the celC gene and its homologue from E. coli, yhjM, in an expression vector and expressed the both genes in E. coli; we have determined that the YhjM protein is able to complement in vitro cellulose synthesis by extracts of A. tumefaciens celC mutants, we have purified the YhjM protein product and are currently examining its enzymatic activity; we have examined whole cell extracts of CelC and various other cellulose mutants and wild type bacteria for the presence of cellulose oligomers and cellulose; we have examined the ability of extracts of wild type and cellulose mutants including CelC to incorporate UDP-14C-glucose into cellulose and into water-soluble, ethanol-insoluble oligosaccharides; we have made mutants which synthesize greater amounts of cellulose than the wild type; and we have examined the role of cellulose in the formation of biofilms by A. tumefaciens. In addition we have examined the ability of a putative cellulose synthase gene from the tunicate Ciona savignyi to complement an A. tumefaciens celA mutant. The greatest difference between our knowledge of bacterial cellulose synthesis when we started this project and current knowledge is that in 1999 when we wrote the original grant very few bacteria were known to synthesize cellulose and genes involved in this synthesis were sequenced only from Acetobacter species, A. tumefaciens and Rhizobium leguminosarum. Currently many bacteria are known to synthesize cellulose and genes that may be involved have been sequenced from more than 10 species of bacteria. This additional information has raised the possibility of attempting to use genes from one bacterium to complement mutants in another bacterium. This will enable us to examine the question of which genes are responsible for the three dimensional structure of cellulose (since this differs among bacterial species) and also to examine the interactions between the various proteins required for cellulose synthesis. We have carried out one

Characterization of a 1,4-{beta}-D-glucan synthase from Dictyostelium discoideum. Progress report, May 1990--January 1992

Energy Technology Data Exchange (ETDEWEB)

Blanton, R.L.

1992-01-15

Various aspects of research concerning Dictyostelium discoideum are presented. The initial focus of this project was upon: the characterization of potential probes for the cellulose synthase (antibody and nucleic acid), the determination of the cultural induction conditions of cellulose synthesis, the solubilization of the enzyme activity, the development of a non-inhibitory disruption buffer, the generation and isolation of mutant strains deficient in cellulose synthesis, and the development of the capability to determine the degree of polymerization of the in vitro product. I have briefly summarized our most significant findings with only selected data sets being shown in this report in the interest of brevity.

Crystallographic snapshot of cellulose synthesis and membrane translocation.

Science.gov (United States)

Morgan, Jacob L W; Strumillo, Joanna; Zimmer, Jochen

2013-01-10

Cellulose, the most abundant biological macromolecule, is an extracellular, linear polymer of glucose molecules. It represents an essential component of plant cell walls but is also found in algae and bacteria. In bacteria, cellulose production frequently correlates with the formation of biofilms, a sessile, multicellular growth form. Cellulose synthesis and transport across the inner bacterial membrane is mediated by a complex of the membrane-integrated catalytic BcsA subunit and the membrane-anchored, periplasmic BcsB protein. Here we present the crystal structure of a complex of BcsA and BcsB from Rhodobacter sphaeroides containing a translocating polysaccharide. The structure of the BcsA-BcsB translocation intermediate reveals the architecture of the cellulose synthase, demonstrates how BcsA forms a cellulose-conducting channel, and suggests a model for the coupling of cellulose synthesis and translocation in which the nascent polysaccharide is extended by one glucose molecule at a time.

Mapping of a Cellulose-Deficient Mutant Named dwarf1-1 in Sorghum bicolor to the Green Revolution Gene gibberellin20-oxidase Reveals a Positive Regulatory Association between Gibberellin and Cellulose Biosynthesis.

Science.gov (United States)

Petti, Carloalberto; Hirano, Ko; Stork, Jozsef; DeBolt, Seth

2015-09-01

Here, we show a mechanism for expansion regulation through mutations in the green revolution gene gibberellin20 (GA20)-oxidase and show that GAs control biosynthesis of the plants main structural polymer cellulose. Within a 12,000 mutagenized Sorghum bicolor plant population, we identified a single cellulose-deficient and male gametophyte-dysfunctional mutant named dwarf1-1 (dwf1-1). Through the Sorghum propinquum male/dwf1-1 female F2 population, we mapped dwf1-1 to a frameshift in GA20-oxidase. Assessment of GAs in dwf1-1 revealed ablation of GA. GA ablation was antagonistic to the expression of three specific cellulose synthase genes resulting in cellulose deficiency and growth dwarfism, which were complemented by exogenous bioactive gibberellic acid application. Using quantitative polymerase chain reaction, we found that GA was positively regulating the expression of a subset of specific cellulose synthase genes. To cross reference data from our mapped Sorghum sp. allele with another monocotyledonous plant, a series of rice (Oryza sativa) mutants involved in GA biosynthesis and signaling were isolated, and these too displayed cellulose deficit. Taken together, data support a model whereby suppressed expansion in green revolution GA genes involves regulation of cellulose biosynthesis. © 2015 American Society of Plant Biologists. All Rights Reserved.

Recent Progress on Cellulose-Based Electro-Active Paper, Its Hybrid Nanocomposites and Applications.

Science.gov (United States)

Khan, Asif; Abas, Zafar; Kim, Heung Soo; Kim, Jaehwan

2016-07-26

We report on the recent progress and development of research into cellulose-based electro-active paper for bending actuators, bioelectronics devices, and electromechanical transducers. The cellulose electro-active paper is characterized in terms of its biodegradability, chirality, ample chemically modifying capacity, light weight, actuation capability, and ability to form hybrid nanocomposites. The mechanical, electrical, and chemical characterizations of the cellulose-based electro-active paper and its hybrid composites such as blends or coatings with synthetic polymers, biopolymers, carbon nanotubes, chitosan, and metal oxides, are explained. In addition, the integration of cellulose electro-active paper is highlighted to form various functional devices including but not limited to bending actuators, flexible speaker, strain sensors, energy harvesting transducers, biosensors, chemical sensors and transistors for electronic applications. The frontiers in cellulose paper devices are reviewed together with the strategies and perspectives of cellulose electro-active paper and cellulose nanocomposite research and applications.

Recent Progress on Cellulose-Based Electro-Active Paper, Its Hybrid Nanocomposites and Applications

Directory of Open Access Journals (Sweden)

Asif Khan

2016-07-01

Full Text Available We report on the recent progress and development of research into cellulose-based electro-active paper for bending actuators, bioelectronics devices, and electromechanical transducers. The cellulose electro-active paper is characterized in terms of its biodegradability, chirality, ample chemically modifying capacity, light weight, actuation capability, and ability to form hybrid nanocomposites. The mechanical, electrical, and chemical characterizations of the cellulose-based electro-active paper and its hybrid composites such as blends or coatings with synthetic polymers, biopolymers, carbon nanotubes, chitosan, and metal oxides, are explained. In addition, the integration of cellulose electro-active paper is highlighted to form various functional devices including but not limited to bending actuators, flexible speaker, strain sensors, energy harvesting transducers, biosensors, chemical sensors and transistors for electronic applications. The frontiers in cellulose paper devices are reviewed together with the strategies and perspectives of cellulose electro-active paper and cellulose nanocomposite research and applications.

Brittle Culm1, a COBRA-Like Protein, Functions in Cellulose Assembly through Binding Cellulose Microfibrils

Science.gov (United States)

Zhang, Baocai; Liu, Xiangling; Yan, Meixian; Zhang, Lanjun; Shi, Yanyun; Zhang, Mu; Qian, Qian; Li, Jiayang; Zhou, Yihua

2013-01-01

Cellulose represents the most abundant biopolymer in nature and has great economic importance. Cellulose chains pack laterally into crystalline forms, stacking into a complicated crystallographic structure. However, the mechanism of cellulose crystallization is poorly understood. Here, via functional characterization, we report that Brittle Culm1 (BC1), a COBRA-like protein in rice, modifies cellulose crystallinity. BC1 was demonstrated to be a glycosylphosphatidylinositol (GPI) anchored protein and can be released into cell walls by removal of the GPI anchor. BC1 possesses a carbohydrate-binding module (CBM) at its N-terminus. In vitro binding assays showed that this CBM interacts specifically with crystalline cellulose, and several aromatic residues in this domain are essential for binding. It was further demonstrated that cell wall-localized BC1 via the CBM and GPI anchor is one functional form of BC1. X-ray diffraction (XRD) assays revealed that mutations in BC1 and knockdown of BC1 expression decrease the crystallite width of cellulose; overexpression of BC1 and the CBM-mutated BC1s caused varied crystallinity with results that were consistent with the in vitro binding assay. Moreover, interaction between the CBM and cellulose microfibrils was largely repressed when the cell wall residues were pre-stained with two cellulose dyes. Treating wild-type and bc1 seedlings with the dyes resulted in insensitive root growth responses in bc1 plants. Combined with the evidence that BC1 and three secondary wall cellulose synthases (CESAs) function in different steps of cellulose production as revealed by genetic analysis, we conclude that BC1 modulates cellulose assembly by interacting with cellulose and affecting microfibril crystallinity. PMID:23990797

Brittle Culm1, a COBRA-like protein, functions in cellulose assembly through binding cellulose microfibrils.

Directory of Open Access Journals (Sweden)

Lifeng Liu

Full Text Available Cellulose represents the most abundant biopolymer in nature and has great economic importance. Cellulose chains pack laterally into crystalline forms, stacking into a complicated crystallographic structure. However, the mechanism of cellulose crystallization is poorly understood. Here, via functional characterization, we report that Brittle Culm1 (BC1, a COBRA-like protein in rice, modifies cellulose crystallinity. BC1 was demonstrated to be a glycosylphosphatidylinositol (GPI anchored protein and can be released into cell walls by removal of the GPI anchor. BC1 possesses a carbohydrate-binding module (CBM at its N-terminus. In vitro binding assays showed that this CBM interacts specifically with crystalline cellulose, and several aromatic residues in this domain are essential for binding. It was further demonstrated that cell wall-localized BC1 via the CBM and GPI anchor is one functional form of BC1. X-ray diffraction (XRD assays revealed that mutations in BC1 and knockdown of BC1 expression decrease the crystallite width of cellulose; overexpression of BC1 and the CBM-mutated BC1s caused varied crystallinity with results that were consistent with the in vitro binding assay. Moreover, interaction between the CBM and cellulose microfibrils was largely repressed when the cell wall residues were pre-stained with two cellulose dyes. Treating wild-type and bc1 seedlings with the dyes resulted in insensitive root growth responses in bc1 plants. Combined with the evidence that BC1 and three secondary wall cellulose synthases (CESAs function in different steps of cellulose production as revealed by genetic analysis, we conclude that BC1 modulates cellulose assembly by interacting with cellulose and affecting microfibril crystallinity.

Brittle Culm1, a COBRA-like protein, functions in cellulose assembly through binding cellulose microfibrils.

Science.gov (United States)

Liu, Lifeng; Shang-Guan, Keke; Zhang, Baocai; Liu, Xiangling; Yan, Meixian; Zhang, Lanjun; Shi, Yanyun; Zhang, Mu; Qian, Qian; Li, Jiayang; Zhou, Yihua

2013-01-01

Cellulose represents the most abundant biopolymer in nature and has great economic importance. Cellulose chains pack laterally into crystalline forms, stacking into a complicated crystallographic structure. However, the mechanism of cellulose crystallization is poorly understood. Here, via functional characterization, we report that Brittle Culm1 (BC1), a COBRA-like protein in rice, modifies cellulose crystallinity. BC1 was demonstrated to be a glycosylphosphatidylinositol (GPI) anchored protein and can be released into cell walls by removal of the GPI anchor. BC1 possesses a carbohydrate-binding module (CBM) at its N-terminus. In vitro binding assays showed that this CBM interacts specifically with crystalline cellulose, and several aromatic residues in this domain are essential for binding. It was further demonstrated that cell wall-localized BC1 via the CBM and GPI anchor is one functional form of BC1. X-ray diffraction (XRD) assays revealed that mutations in BC1 and knockdown of BC1 expression decrease the crystallite width of cellulose; overexpression of BC1 and the CBM-mutated BC1s caused varied crystallinity with results that were consistent with the in vitro binding assay. Moreover, interaction between the CBM and cellulose microfibrils was largely repressed when the cell wall residues were pre-stained with two cellulose dyes. Treating wild-type and bc1 seedlings with the dyes resulted in insensitive root growth responses in bc1 plants. Combined with the evidence that BC1 and three secondary wall cellulose synthases (CESAs) function in different steps of cellulose production as revealed by genetic analysis, we conclude that BC1 modulates cellulose assembly by interacting with cellulose and affecting microfibril crystallinity.

Cellulose Electro-Active Paper: From Discovery to Technology Applications

Science.gov (United States)

Abas, Zafar; Kim, Heung Soo; Kim, Jaehwan; Kim, Joo-Hyung

2014-09-01

Cellulose electro-active paper (EAPap) is an attractive material of electro-active polymers (EAPs) family due to its smart characteristics. EAPap is thin cellulose film coated with metal electrodes on both sides. Its large displacement output, low actuation voltage and low power consumption can be used for biomimetic sensors/actuators and electromechanical system. Because cellulose EAPap is ultra-lightweight, easy to manufacture, inexpensive, biocompatible, and biodegradable, it has been employed for many applications such as bending actuator, vibration sensor, artificial muscle, flexible speaker, and can be advantageous in areas such as micro-insect robots, micro-flying objects, microelectromechanical systems, biosensors, and flexible displays.

SCREENING OF 6-PYRUVOYL-TETRAHYDROPTERIN SYNTHASE ACTIVITY DEFICIENCY AMONG HYPERP HENYLALANINEMIC PATIENTS

Directory of Open Access Journals (Sweden)

DURDI QUJEQ

1999-10-01

Full Text Available A deficiency of the phenylalanine hydroxylase activity or its cofactor tetrahydrobiopterin may"nlead to hyperphenylalamnemia and as a result, loss of IQ, poor school performance, and"nbehavior problems occurs. Deficiency in 6-pyruvoyl-tetrahydropterin synthase activity is the"nmajor cause of tetrahydrobiopterin deficient phenylketonuria. In this study, blood specimens"nfrom 165 healthy volunteers and 127 children with phenylketonuria were used to determine"nthe 6-pyruvoyl-tetrahydropterin synthase activity. It was found that the activity of 6-"npyruvoyl- tetrahydropterin synthase was decreased in comparison with control [23.46 +/-"n2.94, (mean +/- SD, mmol/ ml/h, n=I27 vs. 127.63 +/- 4.52, n=165, p<0.05]. Results of"nthis study indicate that examination of 6-pyruvoyl-tetrahydropterin synthase activity is helpful"nand may lead to the diagnosis cause of hyperphenylalaninemia.

Cellulose Electro-Active Paper: From Discovery to Technology Applications

Directory of Open Access Journals (Sweden)

Zafar eAbas

2014-09-01

Full Text Available Cellulose electro-active paper (EAPap is an attractive material of electro-active polymers (EAPs family due to its smart characteristics. EAPap is thin cellulose film coated with metal electrodes on both sides. Its large displacement output, low actuation voltage and low power consumption can be used for biomimetic sensors/actuators and electromechanical system. Because cellulose EAPap is ultra-lightweight, easy to manufacture, inexpensive, biocompatible, and biodegradable, it has been employed for many applications such as bending actuator, vibration sensor, artificial muscle, flexible speaker, and can be advantageous in areas such as micro-insect robots, micro-flying objects, microelectromechanical systems, biosensors, and flexible displays.

A Gibberellin-Mediated DELLA-NAC Signaling Cascade Regulates Cellulose Synthesis in Rice[OPEN

Science.gov (United States)

Huang, Debao; Wang, Shaogan; Zhang, Baocai; Shang-Guan, Keke; Shi, Yanyun; Zhang, Dongmei; Liu, Xiangling; Wu, Kun; Xu, Zuopeng; Fu, Xiangdong; Zhou, Yihua

2015-01-01

Cellulose, which can be converted into numerous industrial products, has important impacts on the global economy. It has long been known that cellulose synthesis in plants is tightly regulated by various phytohormones. However, the underlying mechanism of cellulose synthesis regulation remains elusive. Here, we show that in rice (Oryza sativa), gibberellin (GA) signals promote cellulose synthesis by relieving the interaction between SLENDER RICE1 (SLR1), a DELLA repressor of GA signaling, and NACs, the top-layer transcription factors for secondary wall formation. Mutations in GA-related genes and physiological treatments altered the transcription of CELLULOSE SYNTHASE genes (CESAs) and the cellulose level. Multiple experiments demonstrated that transcription factors NAC29/31 and MYB61 are CESA regulators in rice; NAC29/31 directly regulates MYB61, which in turn activates CESA expression. This hierarchical regulation pathway is blocked by SLR1-NAC29/31 interactions. Based on the results of anatomical analysis and GA content examination in developing rice internodes, this signaling cascade was found to be modulated by varied endogenous GA levels and to be required for internode development. Genetic and gene expression analyses were further performed in Arabidopsis thaliana GA-related mutants. Altogether, our findings reveal a conserved mechanism by which GA regulates secondary wall cellulose synthesis in land plants and provide a strategy for manipulating cellulose production and plant growth. PMID:26002868

A Gibberellin-Mediated DELLA-NAC Signaling Cascade Regulates Cellulose Synthesis in Rice.

Science.gov (United States)

Huang, Debao; Wang, Shaogan; Zhang, Baocai; Shang-Guan, Keke; Shi, Yanyun; Zhang, Dongmei; Liu, Xiangling; Wu, Kun; Xu, Zuopeng; Fu, Xiangdong; Zhou, Yihua

2015-06-01

Cellulose, which can be converted into numerous industrial products, has important impacts on the global economy. It has long been known that cellulose synthesis in plants is tightly regulated by various phytohormones. However, the underlying mechanism of cellulose synthesis regulation remains elusive. Here, we show that in rice (Oryza sativa), gibberellin (GA) signals promote cellulose synthesis by relieving the interaction between SLENDER RICE1 (SLR1), a DELLA repressor of GA signaling, and NACs, the top-layer transcription factors for secondary wall formation. Mutations in GA-related genes and physiological treatments altered the transcription of CELLULOSE SYNTHASE genes (CESAs) and the cellulose level. Multiple experiments demonstrated that transcription factors NAC29/31 and MYB61 are CESA regulators in rice; NAC29/31 directly regulates MYB61, which in turn activates CESA expression. This hierarchical regulation pathway is blocked by SLR1-NAC29/31 interactions. Based on the results of anatomical analysis and GA content examination in developing rice internodes, this signaling cascade was found to be modulated by varied endogenous GA levels and to be required for internode development. Genetic and gene expression analyses were further performed in Arabidopsis thaliana GA-related mutants. Altogether, our findings reveal a conserved mechanism by which GA regulates secondary wall cellulose synthesis in land plants and provide a strategy for manipulating cellulose production and plant growth. © 2015 American Society of Plant Biologists. All rights reserved.

Molecular size estimation of plasma membrane β-glucan synthase from red beet root

International Nuclear Information System (INIS)

Sloan, M.E.; Eiberger, L.L.; Wasserman, B.P.

1986-01-01

Cellulose and cell wall β-D-glucans in higher plants are thought to be synthesized by the plasma membrane enzyme, β-glucan synthase. This enzyme has never been purified to homogeneity, hence its subunit composition is unknown. Partial purification of red beet root glucan synthase by glycerol density gradient centrifugation followed by SDS-PAGE yielded a highly enriched subunit of 68 kDa. Radiation inactivation of plasma membranes gave a molecular size the 450 kDa for the holoenzyme complex. This suggests that glucan synthase consists of 6 to 7 subunits and confirms electron microscope studies showing that glucan synthases exist as multi-subunit complexes embedded within the membrane

Platelet-derived growth factor (PDGF) stimulates glycogen synthase activity in 3T3 cells

International Nuclear Information System (INIS)

Chan, C.P.; Bowen-Pope, D.F.; Ross, R.; Krebs, E.G.

1986-01-01

Hormonal regulation of glycogen synthase, an enzyme that can be phosphorylated on multiple sites, is often associated with changes in its phosphorylation state. Enzyme activation is conventionally monitored by determining the synthase activity ratio [(activity in the absence of glucose 6-P)/(activity in the presence of glucose 6-P)]. Insulin causes an activation of glycogen synthase with a concomitant decrease in its phosphate content. In a previous report, the authors showed that epidermal growth factor (EGF) increases the glycogen synthase activity ratio in Swiss 3T3 cells. The time and dose-dependency of this response was similar to that of insulin. Their recent results indicate that PDGF also stimulates glycogen synthase activity. Enzyme activation was maximal after 30 min. of incubation with PDGF; the time course observed was very similar to that with insulin and EGF. At 1 ng/ml (0.03nM), PDGF caused a maximal stimulation of 4-fold in synthase activity ratio. Half-maximal stimulation was observed at 0.2 ng/ml (6 pM). The time course of changes in enzyme activity ratio closely followed that of 125 I-PDGF binding. The authors data suggest that PDGF, as well as EFG and insulin, may be important in regulating glycogen synthesis through phosphorylation/dephosphorylation mechanisms

Suite of Activity-Based Probes for Cellulose-Degrading Enzymes

Energy Technology Data Exchange (ETDEWEB)

Chauvigne-Hines, Lacie M.; Anderson, Lindsey N.; Weaver, Holly M.; Brown, Joseph N.; Koech, Phillip K.; Nicora, Carrie D.; Hofstad, Beth A.; Smith, Richard D.; Wilkins, Michael J.; Callister, Stephen J.; Wright, Aaron T.

2012-12-19

Microbial glycoside hydrolases play a dominant role in the biochemical conversion of cellulosic biomass to high-value biofuels. Anaerobic cellulolytic bacteria are capable of producing multicomplex catalytic subunits containing cell-adherent cellulases, hemicellulases, xylanases, and other glycoside hydrolases to facilitate the degradation of highly recalcitrant cellulose and other related plant cell wall polysaccharides. Clostridium thermocellum is a cellulosome producing bacterium that couples rapid reproduction rates to highly efficient degradation of crystalline cellulose. Herein, we have developed and applied a suite of difluoromethylphenyl aglycone, N-halogenated glycosylamine, and 2-deoxy-2-fluoroglycoside activity-based protein profiling (ABPP) probes to the direct labeling of the C. thermocellum cellulosomal secretome. These activity-based probes (ABPs) were synthesized with alkynes to harness the utility and multimodal possibilities of click chemistry, and to increase enzyme active site inclusion for LC-MS analysis. We directly analyzed ABP-labeled and unlabeled global MS data, revealing ABP selectivity for glycoside hydrolase (GH) enzymes in addition to a large collection of integral cellulosome-containing proteins. By identifying reactivity and selectivity profiles for each ABP, we demonstrate our ability to widely profile the functional cellulose degrading machinery of the bacterium. Derivatization of the ABPs, including reactive groups, acetylation of the glycoside binding groups, and mono- and disaccharide binding groups, resulted in considerable variability in protein labeling. Our probe suite is applicable to aerobic and anaerobic cellulose degrading systems, and facilitates a greater understanding of the organismal role associated within biofuel development.

A cellulose synthase-like protein is required for osmotic stress tolerance in Arabidopsis

KAUST Repository

Zhu, Jianhua

2010-04-16

Osmotic stress imposed by soil salinity and drought stress significantly affects plant growth and development, but osmotic stress sensing and tolerance mechanisms are not well understood. Forward genetic screens using a root-bending assay have previously identified salt overly sensitive (sos) mutants of Arabidopsis that fall into five loci, SOS1 to SOS5. These loci are required for the regulation of ion homeostasis or cell expansion under salt stress, but do not play a major role in plant tolerance to the osmotic stress component of soil salinity or drought. Here we report an additional sos mutant, sos6-1, which defines a locus essential for osmotic stress tolerance. sos6-1 plants are hypersensitive to salt stress and osmotic stress imposed by mannitol or polyethylene glycol in culture media or by water deficit in the soil. SOS6 encodes a cellulose synthase-like protein, AtCSLD5. Only modest differences in cell wall chemical composition could be detected, but we found that sos6-1 mutant plants accumulate high levels of reactive oxygen species (ROS) under osmotic stress and are hypersensitive to the oxidative stress reagent methyl viologen. The results suggest that SOS6/AtCSLD5 is not required for normal plant growth and development but has a critical role in osmotic stress tolerance and this function likely involves its regulation of ROS under stress. © 2010 Blackwell Publishing Ltd.

Impaired glycogen synthase activity and mitochondrial dysfunction in skeletal muscle

DEFF Research Database (Denmark)

Højlund, Kurt; Beck-Nielsen, Henning

2006-01-01

Insulin resistance in skeletal muscle is a major hallmark of type 2 diabetes and an early detectable abnormality in the development of this disease. The cellular mechanisms of insulin resistance include impaired insulin-mediated muscle glycogen synthesis and increased intramyocellular lipid content......, whereas impaired insulin activation of muscle glycogen synthase represents a consistent, molecular defect found in both type 2 diabetic and high-risk individuals. Despite several studies of the insulin signaling pathway believed to mediate dephosphorylation and hence activation of glycogen synthase......, the molecular mechanisms responsible for this defect remain unknown. Recently, the use of phospho-specific antibodies in human diabetic muscle has revealed hyperphosphorylation of glycogen synthase at sites not regulated by the classical insulin signaling pathway. In addition, novel approaches such as gene...

Possibility of cellulose-based electro-active paper energy scavenging transducer.

Science.gov (United States)

Abas, Zafar; Kim, Heung Soo; Zhai, Lindong; Kim, Jaehwan; Kim, Joo Hyung

2014-10-01

In this paper, a cellulose-based Electro-Active Paper (EAPap) energy scavenging transducer is presented. Cellulose is proven as a smart material, and exhibits piezoelectric effect. Specimens were prepared by coating gold electrodes on both sides of cellulose film. The fabricated specimens were tested by a base excited aluminum cantilever beam at resonant frequency. Different tests were performed with single and multiple parallel connected electrodes coated on the cellulose film. A maximum of 131 mV output voltage was measured, when three electrodes were connected in parallel. It was observed that voltage output increases significantly with the area of electrodes. From these results, it can be concluded that the piezoelectricity of cellulose-based EAPap can be used in energy transduction application.

Recent Progress on Cellulose-Based Electro-Active Paper, Its Hybrid Nanocomposites and Applications

OpenAIRE

Asif Khan; Zafar Abas; Heung Soo Kim; Jaehwan Kim

2016-01-01

We report on the recent progress and development of research into cellulose-based electro-active paper for bending actuators, bioelectronics devices, and electromechanical transducers. The cellulose electro-active paper is characterized in terms of its biodegradability, chirality, ample chemically modifying capacity, light weight, actuation capability, and ability to form hybrid nanocomposites. The mechanical, electrical, and chemical characterizations of the cellulose-based electro-active pa...

Interrelationships between cellulase activity and cellulose particle morphology

DEFF Research Database (Denmark)

Olsen, Johan Pelck; Donohoe, Bryon S.; Borch, Kim

2016-01-01

It is well documented that the enzymatic hydrolysis of cellulose follows a reaction pattern where an initial phase of relatively high activity is followed by a gradual slow-down over the entire course of the reaction. This phenomenon is not readily explained by conventional factors like substrate...... on this observation we argue that cellulose structure, specifically surface area and roughness, plays a major role in the ubiquitous rate loss observed for cellulases....... depletion, product inhibition or enzyme instability. It has been suggested that the underlying reason for the loss of enzyme activity is connected to the heterogeneous structure of cellulose, but so far attempts to establish quantitative measures of such a correlation remain speculative. Here, we have...... to observe and quantify structural features at μm and nm resolution, respectively. We implemented a semi-automatic image analysis protocol, which allowed us to analyze almost 3000 individual micrographs comprising a total of more than 300,000 particles. From this analysis we estimated the temporal...

Waste Composite Sensor Designed by Cellulose and Activated Carbon as Ethylene Absorber

Directory of Open Access Journals (Sweden)

S. Ummartyotin

2016-01-01

Full Text Available Activated carbon was successfully derived from scrap tile waste from thermochemical conversion. Chemical and physical modifications were therefore employed to modify the specific surface area and porosity of activated carbon. Cellulose was successfully extracted from palm front. Designation of waste composite was prepared by cellulose and activated carbon. Less than 30 wt% of activated carbon was integrated into cellulose sheet matrix. It was important to note that there is no change in mechanical and morphological properties. Small amount of activated carbon was well dispersed. In order to investigate the feasibility of composite as active packaging, oxygen permeation rate and ethylene gas adsorption ability were preliminary investigated.

Cyclic diguanylic acid and cellulose synthesis in Agrobacterium tumefaciens

International Nuclear Information System (INIS)

Amikam, D.; Benziman, M.

1989-01-01

The occurrence of the novel regulatory nucleotide bis(3',5')-cyclic diguanylic acid (c-di-GMP) and its relation to cellulose biogenesis in the plant pathogen Agrobacterium tumefaciens was studied. c-di-GMP was detected in acid extracts of 32 P-labeled cells grown in various media, and an enzyme responsible for its formation from GTP was found to be present in cell-free preparations. Cellulose synthesis in vivo was quantitatively assessed with [ 14 C]glucose as a tracer. The organism produced cellulose during growth in the absence of plant cells, and this capacity was retained in resting cells. Synthesis of a cellulosic product from UDP-glucose in vitro with membrane preparations was markedly stimulated by c-di-GMP and its precursor GTP and was further enhanced by Ca2+. The calcium effect was attributed to inhibition of a c-di-GMP-degrading enzyme shown to be present in the cellulose synthase-containing membranes

Phytochelatin synthase activity as a marker of metal pollution

Energy Technology Data Exchange (ETDEWEB)

Zitka, Ondrej; Krystofova, Olga; Sobrova, Pavlina [Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Zemedelska 1, CZ-613 00 Brno (Czech Republic); Adam, Vojtech [Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Zemedelska 1, CZ-613 00 Brno (Czech Republic); Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, CZ-616 00 Brno (Czech Republic); Zehnalek, Josef; Beklova, Miroslava [Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Zemedelska 1, CZ-613 00 Brno (Czech Republic); Kizek, Rene, E-mail: kizek@sci.muni.cz [Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Zemedelska 1, CZ-613 00 Brno (Czech Republic); Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, CZ-616 00 Brno (Czech Republic)

2011-08-30

Highlights: {yields} New tool for determination of phytochelatin synthase activity. {yields} The optimization of experimental condition for determination of the enzyme activity. {yields} First evaluation of K{sub m} for the enzyme. {yields} The effects of cadmium (II) not only on the activity of the enzyme but also on K{sub m}. -- Abstract: The synthesis of phytochelatins is catalyzed by {gamma}-Glu-Cys dipeptidyl transpeptidase called phytochelatin synthase (PCS). Aim of this study was to suggest a new tool for determination of phytochelatin synthase activity in the tobacco BY-2 cells treated with different concentrations of the Cd(II). After the optimization steps, an experiment on BY-2 cells exposed to different concentrations of Cd(NO{sub 3}){sub 2} for 3 days was performed. At the end of the experiment, cells were harvested and homogenized. Reduced glutathione and cadmium (II) ions were added to the cell suspension supernatant. These mixtures were incubated at 35 {sup o}C for 30 min and analysed using high performance liquid chromatography coupled with electrochemical detector (HPLC-ED). The results revealed that PCS activity rises markedly with increasing concentration of cadmium (II) ions. The lowest concentration of the toxic metal ions caused almost three fold increase in PCS activity as compared to control samples. The activity of PCS (270 fkat) in treated cells was more than seven times higher in comparison to control ones. K{sub m} for PCS was estimated as 2.3 mM.

Phytochelatin synthase activity as a marker of metal pollution

International Nuclear Information System (INIS)

Zitka, Ondrej; Krystofova, Olga; Sobrova, Pavlina; Adam, Vojtech; Zehnalek, Josef; Beklova, Miroslava; Kizek, Rene

2011-01-01

Highlights: → New tool for determination of phytochelatin synthase activity. → The optimization of experimental condition for determination of the enzyme activity. → First evaluation of K m for the enzyme. → The effects of cadmium (II) not only on the activity of the enzyme but also on K m . -- Abstract: The synthesis of phytochelatins is catalyzed by γ-Glu-Cys dipeptidyl transpeptidase called phytochelatin synthase (PCS). Aim of this study was to suggest a new tool for determination of phytochelatin synthase activity in the tobacco BY-2 cells treated with different concentrations of the Cd(II). After the optimization steps, an experiment on BY-2 cells exposed to different concentrations of Cd(NO 3 ) 2 for 3 days was performed. At the end of the experiment, cells were harvested and homogenized. Reduced glutathione and cadmium (II) ions were added to the cell suspension supernatant. These mixtures were incubated at 35 o C for 30 min and analysed using high performance liquid chromatography coupled with electrochemical detector (HPLC-ED). The results revealed that PCS activity rises markedly with increasing concentration of cadmium (II) ions. The lowest concentration of the toxic metal ions caused almost three fold increase in PCS activity as compared to control samples. The activity of PCS (270 fkat) in treated cells was more than seven times higher in comparison to control ones. K m for PCS was estimated as 2.3 mM.

Genome-wide analysis of the cellulose synthase-like (Csl) gene family in bread wheat (Triticum aestivum L.).

Science.gov (United States)

Kaur, Simerjeet; Dhugga, Kanwarpal S; Beech, Robin; Singh, Jaswinder

2017-11-03

Hemicelluloses are a diverse group of complex, non-cellulosic polysaccharides, which constitute approximately one-third of the plant cell wall and find use as dietary fibres, food additives and raw materials for biofuels. Genes involved in hemicellulose synthesis have not been extensively studied in small grain cereals. In efforts to isolate the sequences for the cellulose synthase-like (Csl) gene family from wheat, we identified 108 genes (hereafter referred to as TaCsl). Each gene was represented by two to three homeoalleles, which are named as TaCslXY_ZA, TaCslXY_ZB, or TaCslXY_ZD, where X denotes the Csl subfamily, Y the gene number and Z the wheat chromosome where it is located. A quarter of these genes were predicted to have 2 to 3 splice variants, resulting in a total of 137 putative translated products. Approximately 45% of TaCsl genes were located on chromosomes 2 and 3. Sequences from the subfamilies C and D were interspersed between the dicots and grasses but those from subfamily A clustered within each group of plants. Proximity of the dicot-specific subfamilies B and G, to the grass-specific subfamilies H and J, respectively, points to their common origin. In silico expression analysis in different tissues revealed that most of the genes were expressed ubiquitously and some were tissue-specific. More than half of the genes had introns in phase 0, one-third in phase 2, and a few in phase 1. Detailed characterization of the wheat Csl genes has enhanced the understanding of their structural, functional, and evolutionary features. This information will be helpful in designing experiments for genetic manipulation of hemicellulose synthesis with the goal of developing improved cultivars for biofuel production and increased tolerance against various stresses.

Modulation of hyaluronan synthase activity in cellular membrane fractions

OpenAIRE

Vigetti, Davide; Genasetti, A; Karousou, Evgenia; Viola, Manuela; Clerici, M; Bartolini, B; Moretto, Paola; DE LUCA, Giancarlo; Hascall, Vc; Passi, Alberto

2009-01-01

Hyaluronan (HA), the only non-sulfated glycosaminoglycan, is involved in morphogenesis, wound healing, inflammation, angiogenesis, and cancer. In mammals, HA is synthesized by three homologous HA synthases, HAS1, HAS2, and HAS3, that polymerize the HA chain using UDP-glucuronic acid and UDP-N-acetylglucosamine as precursors. Since the amount of HA is critical in several pathophysiological conditions, we developed a non-radioactive assay for measuring the activity of HA synthases (HASs) in euk...

Cytidine triphosphate synthase activity and mRNA expression in normal human blood cells

NARCIS (Netherlands)

Verschuur, A. C.; van Gennip, A. H.; Muller, E. J.; Voûte, P. A.; Vreken, P.; van Kuilenburg, A. B.

1999-01-01

Cytidine triphosphate (CTP) synthase is one of the key enzymes in pyrimidine nucleotide anabolic pathways. The activity of this enzyme is elevated in various malignancies including acute lymphocytic leukemia (ALL). In this study we investigated the activity of CTP synthase in various human blood

Integration of Physical, Genetic, and Cytogenetic Mapping Data for Cellulose Synthase (CesA) Genes in Flax (Linum usitatissimum L.).

Science.gov (United States)

Yurkevich, Olga Y; Kirov, Ilya V; Bolsheva, Nadezhda L; Rachinskaya, Olga A; Grushetskaya, Zoya E; Zoschuk, Svyatoslav A; Samatadze, Tatiana E; Bogdanova, Marina V; Lemesh, Valentina A; Amosova, Alexandra V; Muravenko, Olga V

2017-01-01

Flax, Linum usitatissimum L., is a valuable multi-purpose plant, and currently, its genome is being extensively investigated. Nevertheless, mapping of genes in flax genome is still remaining a challenging task. The cellulose synthase ( CesA ) multigene family involving in the process of cellulose synthesis is especially important for metabolism of this fiber crop. For the first time, fluorescent in situ hybridization (FISH)-based chromosomal localization of the CesA conserved fragment (KF011584.1), 5S, and 26S rRNA genes was performed in landrace, oilseed, and fiber varieties of L. usitatissimum . Intraspecific polymorphism in chromosomal distribution of KF011584.1 and 5S DNA loci was revealed, and the generalized chromosome ideogram was constructed. Using BLAST analysis, available data on physical/genetic mapping and also whole-genome sequencing of flax, localization of KF011584.1, 45S, and 5S rRNA sequences on genomic scaffolds, and their anchoring to the genetic map were conducted. The alignment of the results of FISH and BLAST analyses indicated that KF011584.1 fragment revealed on chromosome 3 could be anchored to linkage group (LG) 11. The common LG for 45S and 5S rDNA was not found probably due to the polymorphic localization of 5S rDNA on chromosome 1. Our findings indicate the complexity of integration of physical, genetic, and cytogenetic mapping data for multicopy gene families in plants. Nevertheless, the obtained results can be useful for future progress in constructing of integrated physical/genetic/cytological maps in L. usitatissimum which are essential for flax breeding.

A high-throughput colorimetric screening assay for terpene synthase activity based on substrate consumption.

Directory of Open Access Journals (Sweden)

Maiko Furubayashi

Full Text Available Terpene synthases catalyze the formation of a variety of terpene chemical structures. Systematic mutagenesis studies have been effective in providing insights into the characteristic and complex mechanisms of C-C bond formations and in exploring the enzymatic potential for inventing new chemical structures. In addition, there is growing demand to increase terpene synthase activity in heterologous hosts, given the maturation of metabolic engineering and host breeding for terpenoid synthesis. We have developed a simple screening method for the cellular activities of terpene synthases by scoring their substrate consumption based on the color loss of the cell harboring carotenoid pathways. We demonstrate that this method can be used to detect activities of various terpene synthase or prenyltransferase genes in a high-throughput manner, irrespective of the product type, enabling the mutation analysis and directed evolution of terpene synthases. We also report the possibility for substrate-specific screening system of terpene synthases by taking advantage of the substrate-size specificity of C30 and C40 carotenoid pathways.

Zinc oxide nanorod clusters deposited seaweed cellulose sheet for antimicrobial activity.

Science.gov (United States)

Bhutiya, Priyank L; Mahajan, Mayur S; Abdul Rasheed, M; Pandey, Manoj; Zaheer Hasan, S; Misra, Nirendra

2018-06-01

Seaweed cellulose was isolated from green seaweed Ulva fasciata using a common bleaching agent. Sheet containing porous mesh was prepared from the extracted seaweed crystalline cellulose along with zinc oxide (ZnO) nanorod clusters grown over the sheet by single step hydrothermal method. Seaweed cellulose and zinc oxide nanorod clusters deposited seaweed cellulose sheet was characterized by FT-IR, XRD, TGA, and SEM-EDX. Morphology showed that the diameter of zinc oxide nanorods were around 70nm. Zinc oxide nanorod clusters deposited on seaweed cellulose sheet gave remarkable antibacterial activity towards gram-positive (Staphylococcus aureus, Bacillus ceresus, Streptococcus thermophilis) and gram-negative (Escherichia coli, Pseudomonas aeruginous) microbes. Such deposited sheet has potential applications in pharmaceutical, biomedical, food packaging, water treatment and biotechnological industries. Copyright © 2018 Elsevier B.V. All rights reserved.

Gibberellin overproduction promotes sucrose synthase expression and secondary cell wall deposition in cotton fibers.

Directory of Open Access Journals (Sweden)

Wen-Qin Bai

Full Text Available Bioactive gibberellins (GAs comprise an important class of natural plant growth regulators and play essential roles in cotton fiber development. To date, the molecular base of GAs' functions in fiber development is largely unclear. To address this question, the endogenous bioactive GA levels in cotton developing fibers were elevated by specifically up-regulating GA 20-oxidase and suppressing GA 2-oxidase via transgenic methods. Higher GA levels in transgenic cotton fibers significantly increased micronaire values, 1000-fiber weight, cell wall thickness and cellulose contents of mature fibers. Quantitative RT-PCR and biochemical analysis revealed that the transcription of sucrose synthase gene GhSusA1 and sucrose synthase activities were significantly enhanced in GA overproducing transgenic fibers, compared to the wild-type cotton. In addition, exogenous application of bioactive GA could promote GhSusA1 expression in cultured fibers, as well as in cotton hypocotyls. Our results suggested that bioactive GAs promoted secondary cell wall deposition in cotton fibers by enhancing sucrose synthase expression.

The valine and lysine residues in the conserved FxVTxK motif are important for the function of phylogenetically distant plant cellulose synthases

Energy Technology Data Exchange (ETDEWEB)

Slabaugh, Erin; Scavuzzo-Duggan, Tess; Chaves, Arielle; Wilson, Liza; Wilson, Carmen; Davis, Jonathan K.; Cosgrove, Daniel J.; Anderson, Charles T.; Roberts, Alison W.; Haigler, Candace H.

2015-12-08

Cellulose synthases (CESAs) synthesize the β-1,4-glucan chains that coalesce to form cellulose microfibrils in plant cell walls. In addition to a large cytosolic (catalytic) domain, CESAs have eight predicted transmembrane helices (TMHs). However, analogous to the structure of BcsA, a bacterial CESA, predicted TMH5 in CESA may instead be an interfacial helix. This would place the conserved FxVTxK motif in the plant cell cytosol where it could function as a substrate-gating loop as occurs in BcsA. To define the functional importance of the CESA region containing FxVTxK, we tested five parallel mutations in Arabidopsis thaliana CESA1 and Physcomitrella patens CESA5 in complementation assays of the relevant cesa mutants. In both organisms, the substitution of the valine or lysine residues in FxVTxK severely affected CESA function. In Arabidopsis roots, both changes were correlated with lower cellulose anisotropy, as revealed by Pontamine Fast Scarlet. Analysis of hypocotyl inner cell wall layers by atomic force microscopy showed that two altered versions of Atcesa1 could rescue cell wall phenotypes observed in the mutant background line. Overall, the data show that the FxVTxK motif is functionally important in two phylogenetically distant plant CESAs. The results show that Physcomitrella provides an efficient model for assessing the effects of engineered CESA mutations affecting primary cell wall synthesis and that diverse testing systems can lead to nuanced insights into CESA structure–function relationships. Although CESA membrane topology needs to be experimentally determined, the results support the possibility that the FxVTxK region functions similarly in CESA and BcsA.

Electrically aligned cellulose film for electro-active paper and its piezoelectricity

International Nuclear Information System (INIS)

Yun, Sungryul; Jang, Sangdong; Yun, Gyu-Young; Kim, Jaehwan

2009-01-01

Electrically aligned regenerated cellulose films were fabricated and the effect of applied electric field was investigated for the piezoelectricity of electro-active paper (EAPap). The EAPap was fabricated by coating gold electrodes on both sides of regenerated cellulose film. The cellulose film was prepared by dissolving cotton pulp in LiCl/N,N-dimethylacetamide solution followed by a cellulose chain regeneration process. During the regeneration process an external electric field was applied in the direction of mechanical stretching. Alignment of cellulose fiber chains was investigated as a function of applied electric field. The material characteristics of the cellulose films were analyzed by using an x-ray diffractometer, a field emission scanning electron microscope and a high voltage electron microscope. The application of external electric fields was found to induce formation of nanofibers in the cellulose, resulting in an increase in the crystallinity index (CI) values. It was also found that samples with higher CI values showed higher in-plane piezoelectric constant, d 31 , values. The piezoelectricity of the current EAPap films was measured to be equivalent or better than that of ordinary PVDF films. Therefore, an external electric field applied to a cellulose film along with a mechanical stretching during the regeneration process can enhance the piezoelectricity. (technical note)

Integration of Physical, Genetic, and Cytogenetic Mapping Data for Cellulose Synthase (CesA Genes in Flax (Linum usitatissimum L.

Directory of Open Access Journals (Sweden)

Olga Y. Yurkevich

2017-08-01

Full Text Available Flax, Linum usitatissimum L., is a valuable multi-purpose plant, and currently, its genome is being extensively investigated. Nevertheless, mapping of genes in flax genome is still remaining a challenging task. The cellulose synthase (CesA multigene family involving in the process of cellulose synthesis is especially important for metabolism of this fiber crop. For the first time, fluorescent in situ hybridization (FISH-based chromosomal localization of the CesA conserved fragment (KF011584.1, 5S, and 26S rRNA genes was performed in landrace, oilseed, and fiber varieties of L. usitatissimum. Intraspecific polymorphism in chromosomal distribution of KF011584.1 and 5S DNA loci was revealed, and the generalized chromosome ideogram was constructed. Using BLAST analysis, available data on physical/genetic mapping and also whole-genome sequencing of flax, localization of KF011584.1, 45S, and 5S rRNA sequences on genomic scaffolds, and their anchoring to the genetic map were conducted. The alignment of the results of FISH and BLAST analyses indicated that KF011584.1 fragment revealed on chromosome 3 could be anchored to linkage group (LG 11. The common LG for 45S and 5S rDNA was not found probably due to the polymorphic localization of 5S rDNA on chromosome 1. Our findings indicate the complexity of integration of physical, genetic, and cytogenetic mapping data for multicopy gene families in plants. Nevertheless, the obtained results can be useful for future progress in constructing of integrated physical/genetic/cytological maps in L. usitatissimum which are essential for flax breeding.

Homocysteine threshold value based on cystathionine beta synthase and paraoxonase 1 activities in mice.

Science.gov (United States)

Hamelet, J; Aït-Yahya-Graison, E; Matulewicz, E; Noll, C; Badel-Chagnon, A; Camproux, A-C; Demuth, K; Paul, J-L; Delabar, J M; Janel, N

2007-12-01

Hyperhomocysteinaemia is a metabolic disorder associated with the development of premature atherosclerosis. Among the determinants which predispose to premature thromboembolic and atherothrombotic events, serum activity of paraoxonase 1, mainly synthesized in the liver, has been shown to be a predictor of cardiovascular disease and to be negatively correlated with serum homocysteine levels in human. Even though treatments of hyperhomocysteinaemic patients ongoing cardiovascular complications are commonly used, it still remains unclear above which homocysteine level a preventive therapy should be started. In order to establish a threshold of plasma homocysteine concentration we have analyzed the hepatic cystathionine beta synthase and paraoxonase 1 activities in a moderate to intermediate murine model of hyperhomocysteinaemia. Using wild type and heterozygous cystathionine beta synthase deficient mice fed a methionine enriched diet or a control diet, we first studied the link between cystathionine beta synthase and paraoxonase 1 activities and plasma homocysteine concentration. Among the animals used in this study, we observed a negative correlation between plasma homocysteine level and cystathionine beta synthase activity (rho=-0.52, P=0.0008) or paraoxonase 1 activity (rho=-0.49, P=0.002). Starting from these results, a homocysteine cut-off value of 15 microm has been found for both cystathionine beta synthase (P=0.0003) and paraoxonase 1 (P=0.0007) activities. Our results suggest that both cystathionine beta synthase and paraoxonase 1 activities are significantly decreased in mice with a plasma homocysteine value greater than 15 microm. In an attempt to set up preventive treatment for cardiovascular disease our results indicate that treatments should be started from 15 microm of plasma homocysteine.

Properties of cellulose derivatives produced from radiation-Modified cellulose pulps

International Nuclear Information System (INIS)

Iller, Edward; Stupinska, Halina; Starostka, Pawel

2007-01-01

The aim of project was elaboration of radiation methods for properties modification of cellulose pulps using for derivatives production. The selected cellulose pulps were exposed to an electron beam with energy 10 MeV in a linear accelerator. After irradiation pulps underwent the structural and physico-chemical investigations. The laboratory test for manufacturing carboxymethylocellulose (CMC), cellulose carbamate (CC) and cellulose acetate (CA) with cellulose pulps irradiated dose 10 and 15 kGy have been performed. Irradiation of the pulp influenced its depolimerisation degree and resulted in the drop of viscosity of CMC. However, the expected level of cellulose activation expressed as a rise of the substitution degree or increase of the active substance content in the CMC sodium salt was not observed. In the case of cellulose esters (CC, CA) formation, the action of ionising radiation on cellulose pulps with the dose 10 and 15 kGy enables obtaiment of the average values of polimerisation degree as required for CC soluble in aqueous sodium hydroxide solution. The properties of derivatives prepared by means of radiation and classic methods were compared

Activation of corn cellulose with alcohols to improve its dissolvability in fabricating ultrafine fibers via electrospinning.

Science.gov (United States)

Chen, Haizhen; Ni, Jinping; Chen, Jing; Xue, Wenwen; Wang, Jinggang; Na, Haining; Zhu, Jin

2015-06-05

Water and four small molecular alcohols are respectively used to activate corn cellulose (CN cellulose) with the aim to improve the dissolvability in DMAc/LiCl. Among all these activated agents, monohydric alcohols are found to produce the optimal effect of activation in the whole process including of activating, dissolving, and electrospinning of CN cellulose. Meanwhile, well distributed fibers with the diameter of 500nm-2μm are fabricated in electrospinning. Understanding the activation effect of monohydric alcohols with water and polyhydric alcohols, the most effective activated agent is ascertained with the characteristics of small molecular size, low viscosity, and single functionality. This work is definitely initiated to understand the critical principle of CN cellulose in dissolving. Accordingly, a feasible methodology is also established to prepare ultrafine cellulose fibers with good morphology in electrospinning. Copyright © 2015 Elsevier Ltd. All rights reserved.

Application of a Colorimetric Assay to Identify Putative Ribofuranosylaminobenzene 5'-Phosphate Synthase Genes Expressed with Activity in Escherichia coli

Directory of Open Access Journals (Sweden)

Bechard Matthew E.

2003-01-01

Full Text Available Tetrahydromethanopterin (H4MPT is a tetrahydrofolate analog originally discovered in methanogenic archaea, but later found in other archaea and bacteria. The extent to which H4MPT occurs among living organisms is unknown. The key enzyme which distinguishes the biosynthetic pathways of H4MPT and tetrahydrofolate is ribofuranosylaminobenzene 5'-phosphate synthase (RFAP synthase. Given the importance of RFAP synthase in H4MPT biosynthesis, the identification of putative RFAP synthase genes and measurement of RFAP synthase activity would provide an indication of the presence of H4MPT in untested microorganisms. Investigation of putative archaeal RFAP synthase genes has been hampered by the tendency of the resulting proteins to form inactive inclusion bodies in Escherichia coli. The current work describes a colorimetric assay for measuring RFAP synthase activity, and two modified procedures for expressing recombinant RFAP synthase genes to produce soluble, active enzyme. By lowering the incubation temperature during expression, RFAP synthase from Archaeoglobus fulgidus was produced in E. coli and purified to homogeneity. The production of active RFAP synthase from Methanothermobacter thermautotrophicus was achieved by coexpression of the gene MTH0830 with a molecular chaperone. This is the first direct biochemical identification of a methanogen gene that codes for an active RFAP synthase.

Application of a Colorimetric Assay to Identify Putative Ribofuranosylaminobenzene 5'-Phosphate Synthase Genes Expressed with Activity in Escherichia coli.

Science.gov (United States)

Bechard, Matthew E.; Chhatwal, Sonya; Garcia, Rosemarie E.; Rasche, Madeline E.

2003-01-01

Tetrahydromethanopterin (H(4)MPT) is a tetrahydrofolate analog originally discovered in methanogenic archaea, but later found in other archaea and bacteria. The extent to which H(4)MPT occurs among living organisms is unknown. The key enzyme which distinguishes the biosynthetic pathways of H(4)MPT and tetrahydrofolate is ribofuranosylaminobenzene 5'-phosphate synthase (RFAP synthase). Given the importance of RFAP synthase in H(4)MPT biosynthesis, the identification of putative RFAP synthase genes and measurement of RFAP synthase activity would provide an indication of the presence of H(4)MPT in untested microorganisms. Investigation of putative archaeal RFAP synthase genes has been hampered by the tendency of the resulting proteins to form inactive inclusion bodies in Escherichia coli. The current work describes a colorimetric assay for measuring RFAP synthase activity, and two modified procedures for expressing recombinant RFAP synthase genes to produce soluble, active enzyme. By lowering the incubation temperature during expression, RFAP synthase from Archaeoglobus fulgidus was produced in E. coli and purified to homogeneity. The production of active RFAP synthase from Methanothermobacter thermautotrophicus was achieved by coexpression of the gene MTH0830 with a molecular chaperone. This is the first direct biochemical identification of a methanogen gene that codes for an active RFAP synthase.

[Development of specific and degenerated primers to CesA genes encoding flax (Linum usitatissimum L.) cellulose synthase].

Science.gov (United States)

Grushetskaia, Z E; Lemesh, V A; Khotyleva, L V

2010-01-01

Cellulose synthase catalytic subunit genes, CesA, have been discovered in several higher plant species, and it has been shown that the CesA gene family has multiple members. HVR2 fragment of these genes determine the class specificity of the CESA protein and its participation in the primary or secondary cell wall synthesis. The aim of this study was development of specific and degenerated primers to flax CesA gene fragments leading to obtaining the class specific HVR2 region of the gene. Two pairs of specific primers to the certain fragments of CesA-1 and CesA-6 genes and one pair of degenerated primers to HVR2 region of all flax CesA genes were developed basing on comparison of six CesA EST sequences of flax and full cDNA sequences of Arabidopsis, poplar, maize and cotton plants, obtained from GenBank. After amplification of flax cDNA, the bands of expected size were detected (201 and 300 b.p. for the CesA-1 and CesA-6, and 600 b.p. for the HVR2 region of CesA respectively). The developed markers can be used for cloning and sequencing of flax CesA genes, identifying their number in flax genome, tissue and stage specificity.

Evaluation in Cellulolytic Activity of Stenotrophomonas sp. in Cellulose Nitrogen Free Mineral Medium

International Nuclear Information System (INIS)

Honey Thet Paing Htway; San San Yu; Zaw Ko Latt

2011-12-01

Three bacterial strains were isolated from rice rhizospheric soil and their nitrogen fixing activity was determined in nitrogen free mineral medium and broth with glucose and cellulose as carbon sources and they produced ammonium concentration (above 3ppm) in G-NFFMM and (2-3ppm) in C-NFMM. Moreover, their cellulolytic activity was determined by DNS mothod and strain H3 having the cellulolytic activity was selected. Then, cellulose, carboxymethyl cellulose, baggasse, pea haulm, corn stem, rice straw were used as substrates and determined its reducing sugar concentration. After detection of the cellulolytic activity, the bacteria produced the highest concentration of reducing sugar on cellulose substrate at 12 day incubation period with the reducing sugar amount of 0.12mg/ml and 0.298mg/ml on CMC substrates. In the study of argicultral wastes as substrates, the selected strain, H3, produced in the reducing sugar concentration with 0.12, 0.116,0.103 and 0.098mg/ml respectively. The selected strain was identified by biochemical characterists and 16s ribosomal DNA analysis and it was Stenotrophomonas sp.

Dielectric and polarization behaviour of cellulose electro-active paper (EAPap)

International Nuclear Information System (INIS)

Yun, Gyu-Young; Kim, Joo-Hyung; Kim, Jaehwan

2009-01-01

Dielectric and polarization behaviour of electro-active paper (EAPap) were studied to understand the detailed material behaviour of EAPap as a novel smart material. It was revealed that the dielectric constant of EAPap was temperature and frequency dependent. The largest change in the dielectric constant was observed near 0 0 C while the highest dielectric constant was obtained at around 100 0 C, which might be related to the dipolar behaviour of the hydroxyl structure of cellulose and adsorbed or existing internal water molecules in cellulose EAPap. By thermal stimulated current measurement for polarization behaviour of cellulose EAPap, it was shown that the maximum current was observed in the temperature range 105-110 0 C. Compared with the polarization behaviour in the low temperature range, abnormal polarization was observed under an applied field mainly due to the trapped space charge in EAPap, which indicates that cellulose EAPap has a similar material behaviour to that of electret polymers. (fast track communication)

NOpiates: Novel Dual Action Neuronal Nitric Oxide Synthase Inhibitors with μ-Opioid Agonist Activity.

Science.gov (United States)

Renton, Paul; Green, Brenda; Maddaford, Shawn; Rakhit, Suman; Andrews, John S

2012-03-08

A novel series of benzimidazole designed multiple ligands (DMLs) with activity at the neuronal nitric oxide synthase (nNOS) enzyme and the μ-opioid receptor was developed. Targeting of the structurally dissimilar heme-containing enzyme and the μ-opioid GPCR was predicated on the modulatory role of nitric oxide on μ-opioid receptor function. Structure-activity relationship studies yielded lead compound 24 with excellent nNOS inhibitory activity (IC50 = 0.44 μM), selectivity over both endothelial nitric oxide synthase (10-fold) and inducible nitric oxide synthase (125-fold), and potent μ-opioid binding affinity, K i = 5.4 nM. The functional activity as measured in the cyclic adenosine monosphospate secondary messenger assay resulted in full agonist activity (EC50 = 0.34 μM). This work represents a novel approach in the development of new analgesics for the treatment of pain.

Simultaneous microwave-assisted synthesis, characterization, thermal stability, and antimicrobial activity of cellulose/AgCl nanocomposites

International Nuclear Information System (INIS)

Li, Shu-Ming; Fu, Lian-Hua; Ma, Ming-Guo; Zhu, Jie-Fang; Sun, Run-Cang; Xu, Feng

2012-01-01

By means of a simultaneous microwave-assisted method and a simple chemical reaction, cellulose/AgCl nanocomposites have been successfully synthesized using cellulose solution and AgNO 3 in N,N-dimethylacetamide (DMAc) solvent. The cellulose solution was firstly prepared by the dissolution of the microcrystalline cellulose and lithium chloride (LiCl) in DMAc. DMAc acts as both a solvent and a microwave absorber. LiCl was used as the reactant to fabricate AgCl crystals. The effects of the heating time and heating temperature on the products were studied. This method is based on the simultaneous formation of AgCl nanoparticles and precipitation of the cellulose, leading to a homogeneous distribution of AgCl nanoparticles in the cellulose matrix. The experimental results confirmed the formation of cellulose/AgCl nanocomposites with high-purity, good thermal stability and antimicrobial activity. This rapid, green and environmentally friendly microwave-assisted method opens a new window to the high value-added applications of biomass. -- Highlights: ► Cellulose/AgCl nanocomposites have been synthesized by microwave method. ► Effect of heating temperature on the nanocomposites was researched. ► Thermal stability of the nanocomposites was investigated. ► Cellulose/AgCl nanocomposites had good antimicrobial activity. ► This method is based on the simultaneous formation of AgCl and cellulose.

Chitin synthases from Saprolegnia are involved in tip growth and represent a potential target for anti-oomycete drugs.

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Gea Guerriero

Full Text Available Oomycetes represent some of the most devastating plant and animal pathogens. Typical examples are Phytophthora infestans, which causes potato and tomato late blight, and Saprolegnia parasitica, responsible for fish diseases. Despite the economical and environmental importance of oomycete diseases, their control is difficult, particularly in the aquaculture industry. Carbohydrate synthases are vital for hyphal growth and represent interesting targets for tackling the pathogens. The existence of 2 different chitin synthase genes (SmChs1 and SmChs2 in Saprolegnia monoica was demonstrated using bioinformatics and molecular biology approaches. The function of SmCHS2 was unequivocally demonstrated by showing its catalytic activity in vitro after expression in Pichia pastoris. The recombinant SmCHS1 protein did not exhibit any activity in vitro, suggesting that it requires other partners or effectors to be active, or that it is involved in a different process than chitin biosynthesis. Both proteins contained N-terminal Microtubule Interacting and Trafficking domains, which have never been reported in any other known carbohydrate synthases. These domains are involved in protein recycling by endocytosis. Enzyme kinetics revealed that Saprolegnia chitin synthases are competitively inhibited by nikkomycin Z and quantitative PCR showed that their expression is higher in presence of the inhibitor. The use of nikkomycin Z combined with microscopy showed that chitin synthases are active essentially at the hyphal tips, which burst in the presence of the inhibitor, leading to cell death. S. parasitica was more sensitive to nikkomycin Z than S. monoica. In conclusion, chitin synthases with species-specific characteristics are involved in tip growth in Saprolegnia species and chitin is vital for the micro-organisms despite its very low abundance in the cell walls. Chitin is most likely synthesized transiently at the apex of the cells before cellulose, the major

Immobilization of Cold-Active Cellulase from Antarctic Bacterium and Its Use for Kelp Cellulose Ethanol Fermentation

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Yi Bin Wang

2015-01-01

Full Text Available Immobilization is an effective way to solve the problem associated with the application of cold-active cellulase in industrial processes. In this study, a cold-active cellulase from the Antarctic psychrophilic bacterium Pseudoalteromonas sp. NJ64 was obtained, immobilized, and analyzed for optimal immobilization conditions. Then it was used in kelp cellulose ethanol fermentation, achieving a higher purity level of kelp cellulose ethanol. The enzymatic activity of this cold-active cellulase was 49.7 U/mL. The optimal immobilization process conditions were as follows: sodium alginate, 30 g/L; calcium chloride, 5 g/L; glutaraldehyde, 0.4%; and cross-linking time, 5 h. Under these conditions, the activity recovery rate was 51.58%. The optimum reaction temperature was at 40 °C, the optimum initial pH was 9.0, and the relative enzyme activity was 58.37% after being recovered seven times. A higher purity level of kelp cellulose ethanol has reached (37.37%. Immobilized cold-active cellulase can effectively hydrolyze the cellulose of kelp residue, which is a valuable component of cellulose bio-ethanol production and will have broad implications in the development of the ethanol industry in China.

Four Novel Cellulose Synthase (CESA Genes from Birch (Betula platyphylla Suk. Involved in Primary and Secondary Cell Wall Biosynthesis

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Xuemei Liu

2012-09-01

Full Text Available Cellulose synthase (CESA, which is an essential catalyst for the generation of plant cell wall biomass, is mainly encoded by the CesA gene family that contains ten or more members. In this study; four full-length cDNAs encoding CESA were isolated from Betula platyphylla Suk., which is an important timber species, using RT-PCR combined with the RACE method and were named as BplCesA3, −4, −7 and −8. These deduced CESAs contained the same typical domains and regions as their Arabidopsis homologs. The cDNA lengths differed among these four genes, as did the locations of the various protein domains inferred from the deduced amino acid sequences, which shared amino acid sequence identities ranging from only 63.8% to 70.5%. Real-time RT-PCR showed that all four BplCesAs were expressed at different levels in diverse tissues. Results indicated that BplCESA8 might be involved in secondary cell wall biosynthesis and floral development. BplCESA3 appeared in a unique expression pattern and was possibly involved in primary cell wall biosynthesis and seed development; it might also be related to the homogalacturonan synthesis. BplCESA7 and BplCESA4 may be related to the formation of a cellulose synthase complex and participate mainly in secondary cell wall biosynthesis. The extremely low expression abundance of the four BplCESAs in mature pollen suggested very little involvement of them in mature pollen formation in Betula. The distinct expression pattern of the four BplCesAs suggested they might participate in developments of various tissues and that they are possibly controlled by distinct mechanisms in Betula.

The Effect of Cellulose Crystal Structure and Solid-State Morphology on the Activity of Cellulases

Energy Technology Data Exchange (ETDEWEB)

Stipanovic, Arthur J [SUNY College of Environmental Science and Forestry

2014-11-17

Consistent with the US-DOE and USDA “Roadmap” objective of producing ethanol and chemicals from cellulosic feedstocks more efficiently, a three year research project entitled “The Effect of Cellulose Crystal Structure and Solid-State Morphology on the Activity of Cellulases” was initiated in early 2003 under DOE sponsorship (Project Number DE-FG02-02ER15356). A three year continuation was awarded in June 2005 for the period September 15, 2005 through September 14, 2008. The original goal of this project was to determine the effect of cellulose crystal structure, including allomorphic crystalline form (Cellulose I, II, III, IV and sub-allomorphs), relative degree of crystallinity and crystallite size, on the activity of different types of genetically engineered cellulase enzymes to provide insight into the mechanism and kinetics of cellulose digestion by “pure” enzymes rather than complex mixtures. We expected that such information would ultimately help enhance the accessibility of cellulose to enzymatic conversion processes thereby creating a more cost-effective commercial process yielding sugars for fermentation into ethanol and other chemical products. Perhaps the most significant finding of the initial project phase was that conversion of native bacterial cellulose (Cellulose I; BC-I) to the Cellulose II (BC-II) crystal form by aqueous NaOH “pretreatment” provided an increase in cellulase conversion rate approaching 2-4 fold depending on enzyme concentration and temperature, even when initial % crystallinity values were similar for both allomorphs.

Enhancement of crystallinity of cellulose produced by Escherichia coli through heterologous expression of bcsD gene from Gluconacetobacter xylinus.

Science.gov (United States)

Sajadi, Elaheh; Babaipour, Valiollah; Deldar, Ali Asghar; Yakhchali, Bagher; Fatemi, Seyed Safa-Ali

2017-09-01

To evaluate the crystallinity index of the cellulose produced by Escherichia coli Nissle 1917 after heterologous expression of the cellulose synthase subunit D (bcsD) gene of Gluconacetobacter xylinus BPR2001. The bcsD gene of G. xylinus BPR2001 was expressed in E. coli and its protein product was visualized using SDS-PAGE. FTIR analysis showed that the crystallinity index of the cellulose produced by the recombinants was 0.84, which is 17% more than that of the wild type strain. The increased crystallinity index was also confirmed by X-ray diffraction analysis. The cellulose content was not changed significantly after over-expressing the bcsD. The bcsD gene can improve the crystalline structure of the bacterial cellulose but there is not any significant difference between the amounts of cellulose produced by the recombinant and wild type E. coli Nissle 1917.

Modulation of hyaluronan synthase activity in cellular membrane fractions.

Science.gov (United States)

Vigetti, Davide; Genasetti, Anna; Karousou, Evgenia; Viola, Manuela; Clerici, Moira; Bartolini, Barbara; Moretto, Paola; De Luca, Giancarlo; Hascall, Vincent C; Passi, Alberto

2009-10-30

Hyaluronan (HA), the only non-sulfated glycosaminoglycan, is involved in morphogenesis, wound healing, inflammation, angiogenesis, and cancer. In mammals, HA is synthesized by three homologous HA synthases, HAS1, HAS2, and HAS3, that polymerize the HA chain using UDP-glucuronic acid and UDP-N-acetylglucosamine as precursors. Since the amount of HA is critical in several pathophysiological conditions, we developed a non-radioactive assay for measuring the activity of HA synthases (HASs) in eukaryotic cells and addressed the question of HAS activity during intracellular protein trafficking. We prepared three cellular fractions: plasma membrane, cytosol (containing membrane proteins mainly from the endoplasmic reticulum and Golgi), and nuclei. After incubation with UDP-sugar precursors, newly synthesized HA was quantified by polyacrylamide gel electrophoresis of fluorophore-labeled saccharides and high performance liquid chromatography. This new method measured HAS activity not only in the plasma membrane fraction but also in the cytosolic membranes. This new technique was used to evaluate the effects of 4-methylumbeliferone, phorbol 12-myristate 13-acetate, interleukin 1beta, platelet-derived growth factor BB, and tunicamycin on HAS activities. We found that HAS activity can be modulated by post-translational modification, such as phosphorylation and N-glycosylation. Interestingly, we detected a significant increase in HAS activity in the cytosolic membrane fraction after tunicamycin treatment. Since this compound is known to induce HA cable structures, this result links HAS activity alteration with the capability of the cell to promote HA cable formation.

Eggshell and Bacterial Cellulose Composite Membrane as Absorbent Material in Active Packaging

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S. Ummartyotin

2016-01-01

Full Text Available Bacterial cellulose and eggshell composite was successfully developed. Eggshell was mixed with bacterial cellulose suspension and it was casted as a composite film. CaCO3 derived from eggshell was compared with its commercial availability. It can be noted that good dispersion of eggshell particle was prepared. Eggshell particle was irregular in shape with a variation in size. It existed in bacterial cellulose network. Characterization on composite was focused on thermal and mechanical properties. It showed that flexibility and thermal stability of composite were enhanced. No significant effect of mechanical properties was therefore observed. The thermal stability of composite was stable up to 300°C. The adsorption experiment on water and vegetable oil capacity was performed. The enhancement on adsorption was due to the existence of eggshell in bacterial cellulose composite. It exhibited the potential to be a good candidate for absorbent material in active packaging.

Evaluation of synthase and hemisynthase activities of glucosamine-6-phosphate synthase by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

Science.gov (United States)

Gaucher-Wieczorek, Florence; Guérineau, Vincent; Touboul, David; Thétiot-Laurent, Sophie; Pelissier, Franck; Badet-Denisot, Marie-Ange; Badet, Bernard; Durand, Philippe

2014-08-01

Glucosamine-6-phosphate synthase (GlmS, EC 2.6.1.16) catalyzes the first and rate-limiting step in the hexosamine biosynthetic pathway, leading to the synthesis of uridine-5'-diphospho-N-acetyl-D-glucosamine, the major building block for the edification of peptidoglycan in bacteria, chitin in fungi, and glycoproteins in mammals. This bisubstrate enzyme converts D-fructose-6-phosphate (Fru-6P) and L-glutamine (Gln) into D-glucosamine-6-phosphate (GlcN-6P) and L-glutamate (Glu), respectively. We previously demonstrated that matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) allows determination of the kinetic parameters of the synthase activity. We propose here to refine the experimental protocol to quantify Glu and GlcN-6P, allowing determination of both hemisynthase and synthase parameters from a single assay kinetic experiment, while avoiding interferences encountered in other assays. It is the first time that MALDI-MS is used to survey the activity of a bisubstrate enzyme. Copyright © 2014 Elsevier Inc. All rights reserved.

Constitutive nitric oxide synthase (cNOS activity in Langerhans islets from streptozotocin diabetic rats

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Fonovich de Schroeder T.M.

1998-01-01

Full Text Available Nitric oxide synthase activity was measured in Langerhans islets isolated from control and streptozotocin diabetic rats. The activity of the enzyme was linear up to 150 µg of protein from control rats and was optimal at 0.1 µM calcium, when it was measured after 45 min of incubation at 37oC in the presence of 200 µM arginine. Specific activity of the enzyme was 25 x 10-4 nmol [3H]citrulline 45 min-1 mg protein-1. Streptozotocin diabetic rats exhibited less enzyme activity both in total pancreas homogenate and in isolated Langerhans islets when compared to control animals. Nitric oxide synthase activity measured in control and diabetic rats 15 days after the last streptozotocin injection in the second group of animals corresponded only to a constitutive enzyme since it was not inhibited by aminoguanidine in any of the mentioned groups. Hyperglycemia in diabetic rats may be the consequence of impaired insulin release caused at least in part by reduced positive modulation mediated by constitutive nitric oxide synthase activity, which was dramatically reduced in islets severely damaged after streptozotocin treatment.

Benzalacetone Synthase

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Ikuro eAbe

2012-03-01

Full Text Available Benzalacetone synthase, from the medicinal plant Rheum palmatum (Polygonaceae (RpBAS, is a plant-specific chalcone synthase (CHS superfamily of type III polyketide synthase (PKS. RpBAS catalyzes the one-step, decarboxylative condensation of 4-coumaroyl-CoA with malonyl-CoA to produce the C6-C4 benzalacetone scaffold. The X-ray crystal structures of RpBAS confirmed that the diketide-forming activity is attributable to the characteristic substitution of the conserved active-site "gatekeeper" Phe with Leu. Furthermore, the crystal structures suggested that RpBAS employs novel catalytic machinery for the thioester bond cleavage of the enzyme-bound diketide intermediate and the final decarboxylation reaction to produce benzalacetone. Finally, by exploiting the remarkable substrate tolerance and catalytic versatility of RpBAS, precursor-directed biosynthesis efficiently generated chemically and structurally divergent, unnatural novel polyketide scaffolds. These findings provided a structural basis for the functional diversity of the type III PKS enzymes.

Converting S-limonene synthase to pinene or phellandrene synthases reveals the plasticity of the active site.

Science.gov (United States)

Xu, Jinkun; Ai, Ying; Wang, Jianhui; Xu, Jingwei; Zhang, Yongkang; Yang, Dong

2017-05-01

S-limonene synthase is a model monoterpene synthase that cyclizes geranyl pyrophosphate (GPP) to form S-limonene. It is a relatively specific enzyme as the majority of its products are composed of limonene. In this study, we converted it to pinene or phellandrene synthases after introducing N345A/L423A/S454A or N345I mutations. Further studies on N345 suggest the polarity of this residue plays a critical role in limonene production by stabilizing the terpinyl cation intermediate. If it is mutated to a non-polar residue, further cyclization or hydride shifts occurs so the carbocation migrates towards the pyrophosphate, leading to the production of pinene or phellandrene. On the other hand, mutant enzymes that still possess a polar residue at this position produce limonene as the major product. N345 is not the only polar residue that may stabilize the terpinyl cation because it is not strictly conserved among limonene synthases across species and there are also several other polar residues in this area. These residues could form a "polar pocket" that may collectively play this stabilizing role. Our study provides important insights into the catalytic mechanism of limonene synthases. Furthermore, it also has wider implications on the evolution of terpene synthases. Copyright © 2017 Elsevier Ltd. All rights reserved.

Synthesis of hybrid cellulose nanocomposite bonded with dopamine SiO2/TiO2 and its antimicrobial activity

Science.gov (United States)

Ramesh, Sivalingam; Kim, Gwang-Hoon; Kim, Jaehwan; Kim, Joo-Hyung

2015-04-01

Organic-inorganic hybrid material based cellulose was synthesized by the sol-gel approach. The explosion of activity in this area in the past decade has made tremendous progress in industry or academic both fundamental understanding of sol-gel process and applications of new functionalized hybrid materials. In this present research work, we focused on cellulose-dopamine functionalized SiO2/TiO2 hybrid nanocomposite by sol-gel process. The cellulose-dopamine hybrid nanocomposite was synthesized via γ-aminopropyltriethoxysilane (γ-APTES) coupling agent by in-situ sol-gel process. The chemical structure of cellulose-amine functionalized dopamine bonding to cellulose structure with covalent cross linking hybrids was confirmed by FTIR spectral analysis. The morphological analysis of cellulose-dopamine nanoSiO2/TiO2 hybrid nanocomposite materials was characterized by XRD, SEM and TEM. From this different analysis results indicate that the optical transparency, thermal stability, control morphology of cellulose-dopamine-SiO2/TiO2 hybrid nanocomposite. Furthermore cellulose-dopamine-SiO2/TiO2 hybrid nanocomposite was tested against pathogenic bacteria for antimicrobial activity.

Mechanical properties of cellulose electro-active paper under different environmental conditions

International Nuclear Information System (INIS)

Kim, Heung Soo; Kim, Jaehwan; Jung, Woochul; Ampofo, Joshua; Craft, William; Sankar, Jagannathan

2008-01-01

The mechanical properties of cellulose-based electro-active paper (EAPap) are investigated under various environmental conditions. Cellulose EAPap has been discovered as a smart material that can be used as both sensor and actuator. Its advantages include low voltage operation, light weight, low power consumption, biodegradability and low cost. EAPap is made with cellulose paper coated with thin electrodes. EAPap shows a reversible and reproducible bending movement as well as longitudinal displacement under an electric field. However, EAPap is a complex anisotropic material which has not been fully characterized. This study investigates the mechanical properties of cellulose-based EAPap, including Young's modulus, yield strength, ultimate strength and creep, along with orientation directions, humidity and temperature levels. To test the materials in different humidity and temperature levels, a special material testing system was made that can control the testing environmental conditions. The initial Young's modulus of EAPap is in the range of 4–9 GPa, which was higher than that of other polymer materials. Also, the Young's modulus is orientation dependent, which may be associated with the piezoelectricity of EAPap materials. The elastic strength and stiffness gradually decreased when the humidity and temperature were increased. Creep and relaxation were observed under constant stress and strain, respectively. Through scanning electron microscopy, EAPap is shown to exhibit both layered and oriented cellulose macromolecular structures that impact both the elastic and plastic behavior

The effect of high pressure on the intracellular trehalose synthase activity of Thermus aquaticus.

Science.gov (United States)

Dong, Yongsheng; Ma, Lei; Duan, Yuanliang

2016-01-01

To understand the effect of high pressure on the intracellular trehalose synthase activity, Thermus aquaticus (T. aquaticus) in the logarithmic growth phase was treated with high-pressure air, and its intracellular trehalose synthase (TSase) activity was determined. Our results indicated that pressure is a factor strongly affecting the cell growth. High pressure significantly attenuated the growth rate of T. aquaticus and shortened the duration of stationary phase. However, after 2 h of culture under 1.0 MPa pressure, the activity of intracellular TSase in T. aquaticus reached its maximum value, indicating that pressure can significantly increase the activity of intracellular TSase in T. aquaticus. Thus the present study provides an important guide for the enzymatic production of trehalose.

Preparation of amino-functionalized regenerated cellulose membranes with high catalytic activity.

Science.gov (United States)

Wang, Wei; Bai, Qian; Liang, Tao; Bai, Huiyu; Liu, Xiaoya

2017-09-01

The modification of regenerated cellulose (RC) membranes was carried out by using silane coupling agents presenting primary and secondary amino-groups. The grafting of the amino groups onto the modified cellulose molecule was confirmed by X-ray photoelectron spectroscopies and 13 C nuclear magnetic resonance spectroscopic analyses. The crystallinity of the cellulose membranes (CM) decreased after chemical modification as indicated by the X-ray diffraction results. Moreover, a denser structure was observed at the surface and cross section of the modified membranes by SEM images. The contact angle measurements showed that the silane coupling treatment enhanced the hydrophobicity of the obtained materials. Then the catalytic properties of two types of modified membranes were studied in a batch process by evaluating their catalytic performance in a Knoevenagel condensation. The results indicated that the cellulose membrane grafted with many secondary amines exhibited a better catalytic activity compared to the one grafted only by primary amines. In addition, the compact structure of the modified membranes permitted their application in a pervaporation catalytic membrane reactor. Therefore, functional CM that prepared in this paper represented a promising material in the field of industrial catalysis. Copyright © 2017 Elsevier B.V. All rights reserved.

HAEM SYNTHASE AND COBALT PORPHYRIN SYNTHASE IN VARIOUS MICRO-ORGANISMS.

Science.gov (United States)

PORRA, R J; ROSS, B D

1965-03-01

1. The preparation of a crude extract of Clostridium tetanomorphum containing cobalt porphyrin synthase but little haem-synthase activity is described. 2. The properties of cobalt porphyrin synthase in the clostridial extracts is compared with the properties of a haem synthase present in crude extracts of the yeast Torulopsis utilis. 3. Cobalt porphyrin synthase in extracts of C. tetanomorphum inserts Co(2+) ions into the following dicarboxylic porphyrins in descending order of rate of insertion: meso-, deutero- and proto-porphyrins. Esterification renders meso- and deutero-porphyrins inactive as substrates. Neither the tetracarboxylic (coproporphyrin III) nor the octacarboxylic (uroporphyrin III) compounds are converted into cobalt porphyrins by the extract, but the non-enzymic incorporation of Co(2+) ions into these two porphyrins is rapid. These extracts are unable to insert Mn(2+), Zn(2+), Mg(2+) or Cu(2+) ions into mesoporphyrin. 4. Crude extracts of T. utilis readily insert both Co(2+) and Fe(2+) ions into deutero-, meso, and proto-porphyrins. Unlike the extracts of C. tetanomorphum, these preparations catalyse the insertion of Co(2+) ions into deuteroporphyrin more rapidly than into mesoporphyrin. This parallels the formation of haems by the T. utilis extract. 5. Cobalt porphyrin synthase is present in the particulate fraction of the extracts of C. tetanomorphum but requires a heat-stable factor present in the soluble fraction. This soluble factor can be replaced by GSH. 6. Cobalt porphyrin synthase in the clostridial extract is inhibited by iodoacetamide and to a smaller extent by p-chloromercuribenzoate and N-ethylmaleimide. The haem synthases of T. utilis and Micrococcus denitrificans are also inhibited by various thiol reagents.

NCBI nr-aa BLAST: CBRC-ATHA-03-0002 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-ATHA-03-0002 ref|NP_186955.1| CSLD3 (CELLULOSE SYNTHASE-LIKE 3); cellulose syn...thase/ transferase, transferring glycosyl groups [Arabidopsis thaliana] gb|AAF26119.1|AC012328_22 putative cellulose... synthase catalytic subunit [Arabidopsis thaliana] gb|AAG60543.1|AF232907_1 cellulose synthase-like ...CSLD3 [Arabidopsis thaliana] gb|AAK25890.1|AF360180_1 putative cellulose synthase... catalytic subunit [Arabidopsis thaliana] gb|AAK64073.1| putative cellulose synthase catalytic subunit [Arab

NCBI nr-aa BLAST: CBRC-OSAT-10-0021 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-OSAT-10-0021 ref|NP_186955.1| CSLD3 (CELLULOSE SYNTHASE-LIKE 3); cellulose syn...thase/ transferase, transferring glycosyl groups [Arabidopsis thaliana] gb|AAF26119.1|AC012328_22 putative cellulose... synthase catalytic subunit [Arabidopsis thaliana] gb|AAG60543.1|AF232907_1 cellulose synthase-like ...CSLD3 [Arabidopsis thaliana] gb|AAK25890.1|AF360180_1 putative cellulose synthase... catalytic subunit [Arabidopsis thaliana] gb|AAK64073.1| putative cellulose synthase catalytic subunit [Arab

NCBI nr-aa BLAST: CBRC-OSAT-12-0025 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-OSAT-12-0025 ref|NP_186955.1| CSLD3 (CELLULOSE SYNTHASE-LIKE 3); cellulose syn...thase/ transferase, transferring glycosyl groups [Arabidopsis thaliana] gb|AAF26119.1|AC012328_22 putative cellulose... synthase catalytic subunit [Arabidopsis thaliana] gb|AAG60543.1|AF232907_1 cellulose synthase-like ...CSLD3 [Arabidopsis thaliana] gb|AAK25890.1|AF360180_1 putative cellulose synthase... catalytic subunit [Arabidopsis thaliana] gb|AAK64073.1| putative cellulose synthase catalytic subunit [Arab

Biofilm formation and cellulose expression by Bordetella avium 197N, the causative agent of bordetellosis in birds and an opportunistic respiratory pathogen in humans.

Science.gov (United States)

McLaughlin, Kimberley; Folorunso, Ayorinde O; Deeni, Yusuf Y; Foster, Dona; Gorbatiuk, Oksana; Hapca, Simona M; Immoor, Corinna; Koza, Anna; Mohammed, Ibrahim U; Moshynets, Olena; Rogalsky, Sergii; Zawadzki, Kamil; Spiers, Andrew J

2017-06-01

Although bacterial cellulose synthase (bcs) operons are widespread within the Proteobacteria phylum, subunits required for the partial-acetylation of the polymer appear to be restricted to a few γ-group soil, plant-associated and phytopathogenic pseudomonads, including Pseudomonas fluorescens SBW25 and several Pseudomonas syringae pathovars. However, a bcs operon with acetylation subunits has also been annotated in the unrelated β-group respiratory pathogen, Bordetella avium 197N. Our comparison of subunit protein sequences and GC content analyses confirms the close similarity between the B. avium 197N and pseudomonad operons and suggests that, in both cases, the cellulose synthase and acetylation subunits were acquired as a single unit. Using static liquid microcosms, we can confirm that B. avium 197N expresses low levels of cellulose in air-liquid interface biofilms and that biofilm strength and attachment levels could be increased by elevating c-di-GMP levels like the pseudomonads, but cellulose was not required for biofilm formation itself. The finding that B. avium 197N is capable of producing cellulose from a highly-conserved, but relatively uncommon bcs operon raises the question of what functional role this modified polymer plays during the infection of the upper respiratory tract or survival between hosts, and what environmental signals control its production. Copyright © 2017 Institut Pasteur. All rights reserved.

Cellulose Degradation by Cellulose-Clearing and Non-Cellulose-Clearing Brown-Rot Fungi

OpenAIRE

Highley, Terry L.

1980-01-01

Cellulose degradation by four cellulose-clearing brown-rot fungi in the Coniophoraceae—Coniophora prasinoides, C. puteana, Leucogyrophana arizonica, and L. olivascens—is compared with that of a non-cellulose-clearing brown-rot fungus, Poria placenta. The cellulose- and the non-cellulose-clearing brown-rot fungi apparently employ similar mechanisms to depolymerize cellulose; most likely a nonenzymatic mechanism is involved.

Cellulose aerogels functionalized with polypyrrole and silver nanoparticles: In-situ synthesis, characterization and antibacterial activity.

Science.gov (United States)

Wan, Caichao; Li, Jian

2016-08-01

Green porous and lightweight cellulose aerogels have been considered as promising candidates to substitute some petrochemical host materials to support various nanomaterials. In this work, waste wheat straw was collected as feedstock to fabricate cellulose hydrogels, and a green inexpensive NaOH/polyethylene glycol solution was used as cellulose solvent. Prior to freeze-drying treatment, the cellulose hydrogels were integrated with polypyrrole and silver nanoparticles by easily-operated in-situ oxidative polymerization of pyrrole using silver ions as oxidizing agent. The tri-component hybrid aerogels were characterized by scanning electron microscope, transmission electron microscope, energy dispersive X-ray spectroscopy, selected area electron diffraction, X-ray photoelectron spectroscopy, and X-ray diffraction. Moreover, the antibacterial activity of the hybrid aerogels against Escherichia coli (Gram-negative), Staphylococcus aureus (Gram-positive) and Listeria monocytogenes (intracellular bacteria) was qualitatively and quantitatively investigated by parallel streak method and determination of minimal inhibitory concentration, respectively. This work provides an example of combining cellulose aerogels with nanomaterials, and helps to develop novel forms of cellulose-based functional materials. Copyright © 2016 Elsevier Ltd. All rights reserved.

Glycogen synthase kinase 3β promotes liver innate immune activation by restraining AMP-activated protein kinase activation.

Science.gov (United States)

Zhou, Haoming; Wang, Han; Ni, Ming; Yue, Shi; Xia, Yongxiang; Busuttil, Ronald W; Kupiec-Weglinski, Jerzy W; Lu, Ling; Wang, Xuehao; Zhai, Yuan

2018-02-13

Glycogen synthase kinase 3β (Gsk3β [Gsk3b]) is a ubiquitously expressed kinase with distinctive functions in different types of cells. Although its roles in regulating innate immune activation and ischaemia and reperfusion injuries (IRIs) have been well documented, the underlying mechanisms remain ambiguous, in part because of the lack of cell-specific tools in vivo. We created a myeloid-specific Gsk3b knockout (KO) strain to study the function of Gsk3β in macrophages in a murine liver partial warm ischaemia model. Compared with controls, myeloid Gsk3b KO mice were protected from IRI, with diminished proinflammatory but enhanced anti-inflammatory immune responses in livers. In bone marrow-derived macrophages, Gsk3β deficiency resulted in an early reduction of Tnf gene transcription but sustained increase of Il10 gene transcription on Toll-like receptor 4 stimulation in vitro. These effects were associated with enhanced AMP-activated protein kinase (AMPK) activation, which led to an accelerated and higher level of induction of the novel innate immune negative regulator small heterodimer partner (SHP [Nr0b2]). The regulatory function of Gsk3β on AMPK activation and SHP induction was confirmed in wild-type bone marrow-derived macrophages with a Gsk3 inhibitor. Furthermore, we found that this immune regulatory mechanism was independent of Gsk3β Ser9 phosphorylation and the phosphoinositide 3-kinase-Akt signalling pathway. In vivo, myeloid Gsk3β deficiency facilitated SHP upregulation by ischaemia-reperfusion in liver macrophages. Treatment of Gsk3b KO mice with either AMPK inhibitor or SHP small interfering RNA before the onset of liver ischaemia restored liver proinflammatory immune activation and IRI in these otherwise protected hosts. Additionally, pharmacological activation of AMPK protected wild-type mice from liver IRI, with reduced proinflammatory immune activation. Inhibition of the AMPK-SHP pathway by liver ischaemia was demonstrated in tumour resection

Self-activation of cellulose: A new preparation methodology for activated carbon electrodes in electrochemical capacitors

Energy Technology Data Exchange (ETDEWEB)

Bommier, Clement; Xu, Rui; Wang, Wei; Wang, Xingfeng; Wen, David; Lu, Jun; Ji, Xiulei

2015-04-01

Current synthetic methods of biomass-derived activated carbon call for a costly chemical or physical activation process. Herein, we report a simple one-step annealing synthesis yielding a high surface area cellulose-derived activated carbon. We discover that simply varying the flow rate of Argon during pyrolysis enables ‘self-activation’ reactions that can tune the specific surface areas of the resulting carbon, ranging from 98 m2/g to values as high as 2600 m2/g. Furthermore, we, for the first time, observe a direct evolution of H2 from the pyrolysis, which gives strong evidence towards an in situ self-activation mechanism. Surprisingly, the obtained activated carbon is a crumbled graphene nanostructure composed of interconnected sheets, making it ideal for use in an electrochemical capacitor. The cellulose-derived nanoporous carbon exhibits a capacitance of 132 F g-1 at 1 A g-1, a performance comparable to the state-of-the-art activated carbons. This work presents a fundamentally new angle to look at the synthesis of activated carbon, and highlights the importance of a controlled inert gas flow rate during synthesis in general, as its contributions can have a very large impact on the final material properties.

Characterization and sequencing of the active site of 1-aminocyclopropane-1-carboxylate synthase

International Nuclear Information System (INIS)

Yip, Wing-Kin; Dong, Jian-Guo; Yang, S.F.; Kenny, J.W.; Thompson, G.A.

1990-01-01

The pyridoxal phosphate (PLP)-dependent 1-aminocyclopropane-1-carboxylic acid (ACC) synthase the key enzyme in ethylene biosynthesis, is inactivated by its substrate S-adenosylmethionine (AdoMet). Apple ACC synthase was purified with an immunoaffinity gel, and its active site was probed with NaB 3 H 4 or Ado[ 14 C]Met. Peptide sequencing of both 3 H- and 14 C-labeled peptides revealed a common dodecapeptide of Ser-Leu-Ser-Xaa-Asp-Leu-Gly-Leu-Pro-Gly-Phe-Arg, where Xaa was the modified, radioactive residue in each case. Acid hydrolysis of the 3 H-labeled enzyme released radioactive N-pyridoxyllysine, indicating that the active-site peptide contained lysine at position 4. Mass spectrometry of the 14 C-labeled peptide indicated a protonated molecular ion at m/z 1390.6, from which the mass of Xaa was calculated to be 229, a number that is equivalent to the mass of a lysine residue alkylated by the 2-aminobutyrate portion of AdoMet, as we previously proposed. These results indicate that the same active-site lysine binds the PLP and convalently links to the 2-aminobutyrate portion of AdoMet during inactivation. The active site of tomato ACC synthase was probed in the same manner with Ado [ 14 C]Met. Sequencing of the tomato active-site peptide revealed two highly conserved dodecapeptides; the minor peptide possessed a sequence identical to that of the apple enzyme, whereas the major peptide differed from the minor peptide in that methionine replaced leucine at position 6

Inhibitory effect of vanillin on cellulase activity in hydrolysis of cellulosic biomass.

Science.gov (United States)

Li, Yun; Qi, Benkun; Wan, Yinhua

2014-09-01

Pretreatment of lignocellulosic material produces a wide variety of inhibitory compounds, which strongly inhibit the following enzymatic hydrolysis of cellulosic biomass. Vanillin is a kind of phenolics derived from degradation of lignin. The effect of vanillin on cellulase activity for the hydrolysis of cellulose was investigated in detail. The results clearly showed that vanillin can reversibly and non-competitively inhibit the cellulase activity at appropriate concentrations and the value of IC50 was estimated to be 30 g/L. The inhibition kinetics of cellulase by vanillin was studied using HCH-1 model and inhibition constants were determined. Moreover, investigation of three compounds with similar structure of vanillin on cellulase activity demonstrated that aldehyde group and phenolic hydroxyl groups of vanillin had inhibitory effect on cellulase. These results provide valuable and detailed information for understanding the inhibition of lignin derived phenolics on cellulase. Copyright © 2014 Elsevier Ltd. All rights reserved.

Kinetics of Cellulose Digestion by Fibrobacter succinogenes S85

OpenAIRE

Maglione, G.; Russell, J. B.; Wilson, D. B.

1997-01-01

Growing cultures of Fibrobacter succinogenes S85 digested cellulose at a rapid rate, but nongrowing cells and cell extracts did not have detectable crystalline cellulase activity. Cells that had been growing exponentially on cellobiose initiated cellulose digestion and succinate production immediately, and cellulose-dependent succinate production could be used as an index of enzyme activity against crystalline cellulose. Cells incubated with cellulose never produced detectable cellobiose, and...

Loosenin, a novel protein with cellulose-disrupting activity from Bjerkandera adusta.

Science.gov (United States)

Quiroz-Castañeda, Rosa E; Martínez-Anaya, Claudia; Cuervo-Soto, Laura I; Segovia, Lorenzo; Folch-Mallol, Jorge L

2011-02-11

Expansins and expansin-like proteins loosen cellulose microfibrils, possibly through the rupture of intramolecular hydrogen bonds. Together with the use of lignocellulolytic enzymes, these proteins are potential molecular tools to treat plant biomass to improve saccharification yields. Here we describe a new type of expansin-related fungal protein that we have called loosenin. Its corresponding gene, loos1, from the basidiomycete Bjerkandera adusta, was cloned and heterologously expressed in Saccharomyces cerevisiae. LOOS1 is distantly related to plant expansins through the shared presence of a DPBB domain, however domain II found in plant expansins is absent. LOOS1 binds tightly to cellulose and chitin, and we demonstrate that cotton fibers become susceptible to the action of a commercial cellulase following treatment with LOOS1. Natural fibers of Agave tequilana also become susceptible to hydrolysis by cellulases after loosenin treatment. LOOS1 is a new type of protein with disrupting activity on cellulose. LOOS1 binds polysaccharides, and given its enhancing properties on the action of hydrolytic enzymes, LOOS1 represents a potential additive in the production of fermentable sugars from lignocellulose.

Haptic device development based on electro static force of cellulose electro active paper

Science.gov (United States)

Yun, Gyu-young; Kim, Sang-Youn; Jang, Sang-Dong; Kim, Dong-Gu; Kim, Jaehwan

2011-04-01

Haptic is one of well-considered device which is suitable for demanding virtual reality applications such as medical equipment, mobile devices, the online marketing and so on. Nowadays, many of concepts for haptic devices have been suggested to meet the demand of industries. Cellulose has received much attention as an emerging smart material, named as electro-active paper (EAPap). The EAPap is attractive for mobile haptic devices due to its unique characteristics in terms of low actuation power, suitability for thin devices and transparency. In this paper, we suggest a new concept of haptic actuator with the use of cellulose EAPap. Its performance is evaluated depending on various actuation conditions. As a result, cellulose electrostatic force actuator shows a large output displacement and fast response, which is suitable for mobile haptic devices.

Activation of cellulose by 1,4-dioxane for dissolution in N,N-dimethylacetamide/LiCl

Czech Academy of Sciences Publication Activity Database

Raus, Vladimír; Šturcová, Adriana; Dybal, Jiří; Šlouf, Miroslav; Vacková, Taťana; Šálek, Petr; Kobera, Libor; Vlček, Petr

2012-01-01

Roč. 19, č. 6 (2012), s. 1893-1906 ISSN 0969-0239 R&D Projects: GA ČR GAP108/12/0703; GA ČR GA106/09/1348 Institutional research plan: CEZ:AV0Z40500505 Institutional support: RVO:61389013 Keywords : cellulose activation * cellulose dissolution * 1,4-dioxane Subject RIV: CD - Macromolecular Chemistry Impact factor: 3.476, year: 2012

A green and efficient technology for the degradation of cellulosic materials: structure changes and enhanced enzymatic hydrolysis of natural cellulose pretreated by synergistic interaction of mechanical activation and metal salt.

Science.gov (United States)

Zhang, Yanjuan; Li, Qian; Su, Jianmei; Lin, Ye; Huang, Zuqiang; Lu, Yinghua; Sun, Guosong; Yang, Mei; Huang, Aimin; Hu, Huayu; Zhu, Yuanqin

2015-02-01

A new technology for the pretreatment of natural cellulose was developed, which combined mechanical activation (MA) and metal salt treatments in a stirring ball mill. Different valent metal nitrates were used to investigate the changes in degree of polymerization (DP) and crystallinity index (CrI) of cellulose after MA+metal salt (MAMS) pretreatment, and Al(NO3)3 showed better pretreatment effect than NaNO3 and Zn(NO3)2. The destruction of morphological structure of cellulose was mainly resulted from intense ball milling, and the comparative studies on the changes of DP and crystal structure of MA and MA+Al(NO3)3 pretreated cellulose samples showed a synergistic interaction of MA and Al(NO3)3 treatments with more effective changes of structural characteristics of MA+Al(NO3)3 pretreated cellulose and substantial increase of reducing sugar yield in enzymatic hydrolysis of cellulose. In addition, the results indicated that the presence of Al(NO3)3 had significant enhancement for the enzymatic hydrolysis of cellulose. Copyright © 2014 Elsevier Ltd. All rights reserved.

PhaM is the physiological activator of poly(3-hydroxybutyrate) (PHB) synthase (PhaC1) in Ralstonia eutropha.

Science.gov (United States)

Pfeiffer, Daniel; Jendrossek, Dieter

2014-01-01

Poly(3-hydroxybutyrate) (PHB) synthase (PhaC1) is the key enzyme of PHB synthesis in Ralstonia eutropha and other PHB-accumulating bacteria and catalyzes the polymerization of 3-hydroxybutyryl-CoA to PHB. Activity assays of R. eutropha PHB synthase are characterized by the presence of lag phases and by low specific activity. It is assumed that the lag phase is caused by the time necessary to convert the inactive PhaC1 monomer into the active dimeric form by an unknown priming process. The lag phase can be reduced by addition of nonionic detergents such as hecameg [6-O-(N-heptyl-carbamoyl)-methyl-α-D-glucopyranoside], which apparently accelerates the formation of PhaC1 dimers. We identified the PHB granule-associated protein (PGAP) PhaM as the natural primer (activator) of PHB synthase activity. PhaM was recently discovered as a novel type of PGAP with multiple functions in PHB metabolism. Addition of PhaM to PHB synthase assays resulted in immediate polymerization of 3HB coenzyme A with high specific activity and without a significant lag phase. The effect of PhaM on (i) PhaC1 activity, (ii) oligomerization of PhaC1, (iii) complex formation with PhaC1, and (iv) PHB granule formation in vitro and in vivo was shown by cross-linking experiments of purified proteins (PhaM, PhaC1) with glutardialdehyde, by size exclusion chromatography, and by fluorescence microscopic detection of de novo-synthesized PHB granules.

Xyloglucan Deficiency Disrupts Microtubule Stability and Cellulose Biosynthesis in Arabidopsis, Altering Cell Growth and Morphogenesis

Energy Technology Data Exchange (ETDEWEB)

Xiao, Chaowen; Zhang, Tian; Zheng, Yunzhen; Cosgrove, Daniel J.; Anderson, Charles T.

2015-11-02

Xyloglucan constitutes most of the hemicellulose in eudicot primary cell walls and functions in cell wall structure and mechanics. Although Arabidopsis (Arabidopsis thaliana) xxt1 xxt2 mutants lacking detectable xyloglucan are viable, they display growth defects that are suggestive of alterations in wall integrity. To probe the mechanisms underlying these defects, we analyzed cellulose arrangement, microtubule patterning and dynamics, microtubule- and wall-integrity-related gene expression, and cellulose biosynthesis in xxt1 xxt2 plants. We found that cellulose is highly aligned in xxt1 xxt2 cell walls, that its three-dimensional distribution is altered, and that microtubule patterning and stability are aberrant in etiolated xxt1 xxt2 hypocotyls. We also found that the expression levels of microtubule-associated genes, such as MAP70-5 and CLASP, and receptor genes, such as HERK1 and WAK1, were changed in xxt1 xxt2 plants and that cellulose synthase motility is reduced in xxt1 xxt2 cells, corresponding with a reduction in cellulose content. Our results indicate that loss of xyloglucan affects both the stability of the microtubule cytoskeleton and the production and patterning of cellulose in primary cell walls. These findings establish, to our knowledge, new links between wall integrity, cytoskeletal dynamics, and wall synthesis in the regulation of plant morphogenesis.

Loosenin, a novel protein with cellulose-disrupting activity from Bjerkandera adusta

Directory of Open Access Journals (Sweden)

Segovia Lorenzo

2011-02-01

Full Text Available Abstract Background Expansins and expansin-like proteins loosen cellulose microfibrils, possibly through the rupture of intramolecular hydrogen bonds. Together with the use of lignocellulolytic enzymes, these proteins are potential molecular tools to treat plant biomass to improve saccharification yields. Results Here we describe a new type of expansin-related fungal protein that we have called loosenin. Its corresponding gene, loos1, from the basidiomycete Bjerkandera adusta, was cloned and heterologously expressed in Saccharomyces cerevisiae. LOOS1 is distantly related to plant expansins through the shared presence of a DPBB domain, however domain II found in plant expansins is absent. LOOS1 binds tightly to cellulose and chitin, and we demonstrate that cotton fibers become susceptible to the action of a commercial cellulase following treatment with LOOS1. Natural fibers of Agave tequilana also become susceptible to hydrolysis by cellulases after loosenin treatment. Conclusions LOOS1 is a new type of protein with disrupting activity on cellulose. LOOS1 binds polysaccharides, and given its enhancing properties on the action of hydrolytic enzymes, LOOS1 represents a potential additive in the production of fermentable sugars from lignocellulose.

Electrode effects of a cellulose-based electro-active paper energy harvester

International Nuclear Information System (INIS)

Abas, Zafar; Kim, Heung Soo; Zhai, Lindong; Kim, Jaehwan; Kim, Joo-Hyung

2014-01-01

The possibility of cellulose-based electro-active paper (EAPap) as a vibrational energy transducer was investigated in this paper. Thin cellulose EAPap film specimens were prepared by the regenerating process. Three different metal electrodes of gold, silver and aluminum were deposited on a 50 × 50 mm 2 cellulose film using a thermal evaporator. An aluminum cantilever beam was used as a vibrational bender and EAPap was attached close to the root of the cantilever beam. The voltage output of the EAPap was measured under harmonic base excitation of the cantilever beam. The EAPap with aluminum electrode provided the largest open circuit voltage output compared to those with gold or silver electrodes. The output voltages of the EAPap increased linearly with increase of the area of the electrodes. The output voltages also increased with increasing input acceleration but became saturated at a certain magnitude. From the experimental results, we conclude that EAPap with metal electrodes can be used as a flexible energy harvesting transducer by external mechanical stress, and the output voltage is related to the electrode material due to its work function. (paper)

Development of Biocomposites with Antioxidant Activity Based on Red Onion Extract and Acetate Cellulose

Directory of Open Access Journals (Sweden)

Carol López de Dicastillo

2015-08-01

Full Text Available Antioxidant biocomposites have been successfully developed from cellulose acetate, eco-friendly triethyl citrate plasticizer and onion extract as a source of natural antioxidants. First, an onion extraction process was optimized to obtain the extract with highest antioxidant power. Extracts under absolute ethanol and ethanol 85% were the extracts with the highest antioxidant activity, which were the characterized through different methods, DPPH (2,2-diphenyl-1-picrylhydrazyl and ABTS (2,2ʹ-azinobis(3-ethylbenzothiazoline-6-sulphonate, that measure radical scavenger activity, and polyphenolic and flavonoid content. Afterwards, the extract was incorporated in cellulose acetate as polymer matrix owing to develop an active material intended to oxidative sensitive food products packaging. Different concentrations of onion extract and plasticizer were statistically studied by using response surface methodology in order to analyze the influence of both factors on the release of active compounds and therefore the antioxidant activity of these materials.

A highly prevalent equine glycogen storage disease is explained by constitutive activation of a mutant glycogen synthase

DEFF Research Database (Denmark)

Maile, C A; Hingst, Janne Rasmuss; Mahalingan, K K

2017-01-01

BACKGROUND: Equine type 1 polysaccharide storage myopathy (PSSM1) is associated with a missense mutation (R309H) in the glycogen synthase (GYS1) gene, enhanced glycogen synthase (GS) activity and excessive glycogen and amylopectate inclusions in muscle. METHODS: Equine muscle biochemical...... had significantly higher glycogen content than control horse muscle despite no difference in GS expression. GS activity was significantly higher in muscle from homozygous mutants than from heterozygote and control horses, in the absence and presence of the allosteric regulator, glucose 6 phosphate (G6...

Glutamylation of the DNA sensor cGAS regulates its binding and synthase activity in antiviral immunity.

Science.gov (United States)

Xia, Pengyan; Ye, Buqing; Wang, Shuo; Zhu, Xiaoxiao; Du, Ying; Xiong, Zhen; Tian, Yong; Fan, Zusen

2016-04-01

Cyclic GMP-AMP synthase (cGAS) senses cytosolic DNA during viral infection and catalyzes synthesis of the dinucleotide cGAMP, which activates the adaptor STING to initiate antiviral responses. Here we found that deficiency in the carboxypeptidase CCP5 or CCP6 led to susceptibility to DNA viruses. CCP5 and CCP6 were required for activation of the transcription factor IRF3 and interferons. Polyglutamylation of cGAS by the enzyme TTLL6 impeded its DNA-binding ability, whereas TTLL4-mediated monoglutamylation of cGAS blocked its synthase activity. Conversely, CCP6 removed the polyglutamylation of cGAS, whereas CCP5 hydrolyzed the monoglutamylation of cGAS, which together led to the activation of cGAS. Therefore, glutamylation and deglutamylation of cGAS tightly modulate immune responses to infection with DNA viruses.

Radiation modification of cellulose pulps. Preparation of cellulose derivatives

International Nuclear Information System (INIS)

Iller, E.; Zimek, Z.; Stupinska, H.; Mikolajczyk, W; Starostka, P.

2005-01-01

One of the most common methods of cellulose pulp modification (activation) applied in the production process of cellulose derivatives is the treatment of the pulp with NaOH solutions leading to the formation of alkalicellulose. The product then undergoes a prolonged process of maturation by its storage under specific conditions. The goal of the process is lowering of the molecular weight of cellulose down to the level resulting from various technological requirements. The process is time-consuming and costly; besides, it requires usage of large-capacity technological vessels and produces considerable amounts of liquid waste. Therefore, many attempts have been made to limit or altogether eliminate the highly disadvantageous stage of cellulose treatment with lye. One of the alternatives proposed so far is the radiation treatment of the cellulose pulp. In the pulp exposed to an electron beam, the bonds between molecules of D-antihydroglucopiranoses loosen and the local crystalline lattice becomes destroyed. This facilitates the access of chemical reagents to the inner structure of the cellulose and, in consequence, eliminates the need for the prolonged maturation of alkalicellulose, thus reducing the consumption of chemicals by the whole process. Research aimed at the application of radiation treatment of cellulose pulp for the production of cellulose derivatives has been conducted by a number of scientific institutions including the Institute of Nuclear Chemistry and Technology, Institute of Biopolymers and Chemical Fibres, and Pulp and Paper Research Institute. For the investigations and assessment of the molecular, hypermolecular, morphologic properties and the chemical reactivity, cellulose pulps used for chemical processing, namely Alicell, Borregaard and Ketchikan, as well as paper pulps made from pine and birch wood were selected. The selected cellulose pulps were exposed to an electron beam with an energy of 10 MeV generated in a linear electron accelerator

Multifarious activities of cellulose degrading bacteria from Koala (Phascolarctos cinereus) faeces.

Science.gov (United States)

Singh, Surender; Thavamani, Palanisami; Megharaj, Mallavarapu; Naidu, Ravi

2015-01-01

Cellulose degrading bacteria from koala faeces were isolated using caboxymethylcellulose-Congo red agar, screened in vitro for different hydrolytic enzyme activities and phylogenetically characterized using molecular tools. Bacillus sp. and Pseudomonas sp. were the most prominent bacteria from koala faeces. The isolates demonstrated good xylanase, amylase, lipase, protease, tannase and lignin peroxidase activities apart from endoglucanase activity. Furthermore many isolates grew in the presence of phenanthrene, indicating their probable application for bioremediation. Potential isolates can be exploited further for industrial enzyme production or in bioremediation of contaminated sites.

Intestinal nitric oxide synthase activity changes during experimental colon obstruction.

Science.gov (United States)

Palásthy, Zsolt; Kaszaki, József; Lázár, György; Nagy, Sándor; Boros, Mihály

2006-08-01

The experiments in this study were designed to follow the time course of nitric oxide (NO) synthesis in the large bowel during acute mechanical ileus. Occlusion of the mid-transverse colon was maintained for 420 min in anesthetized dogs. Strain-gauge transducers were used to analyze motility changes on the hepatic and lienal flexures, respectively. Constitutive NO synthase (cNOS) and inducible NOS (iNOS) activities were determined in tissue biopsies, and plasma nitrite/nitrate (NOx) level was measured in the portal blood. Following completion of the baseline studies, the animals were treated with either 7-nitroindazole (7-NI, selective neuronal NOS inhibitor), or N-nitro-L-arginine (NNA, non-selective NOS inhibitor). In the sham-operated group the cNOS activities differed significantly in the oral and aboral tissue samples (oral: 102.9; versus aboral: 62.1 fmol/mg protein/min). The obstruction elicited a significant increase in portal NOx and elevated tissue inducible NO synthase (iNOS) activity. NNA treatment decreased the motility index in both intestinal segments for 60 min, but 120 min later the motility index was significantly elevated (2.5-fold increase in the oral part, and 1.8-fold enhancement in the aboral segment, respectively). Treatment with 7-NI decreased the cNOS activity in the oral and aboral parts by approximately 40% and 70%, respectively, and suppressed the motility increase in the aboral colon segment. The motility of the colon was either significantly increased or decreased, depending on the type and selectivity of the NOS inhibitor compounds applied. NO of neuronal origin is a transmitter that stimulates peristaltic activity; but an increased iNOS/nNOS ratio significantly moderates the obstruction-induced motility increase.

One-step green synthesis of non-hazardous dicarboxyl cellulose flocculant and its flocculation activity evaluation

International Nuclear Information System (INIS)

Zhu, Hangcheng; Zhang, Yong; Yang, Xiaogang; Liu, Hongyi; Shao, Lan; Zhang, Xiumei; Yao, Juming

2015-01-01

The waste management of used flocculants is a thorny issue in the field of wastewater treatment. To natural cellulose based flocculants, utilization of hazardous cellulose solvent and simplification of synthetic procedure are the two urgent problems needing to be further improved. In this work, a series of natural dicarboxyl cellulose flocculants (DCCs) were one-step synthesized via Schiff-base route. The cellulose solvent (NaOH/Urea solution) was utilized during the synthesis process. The full-biodegradable flocculants avoid causing secondary pollution to environment. The chemical structure and solution property of the DCC products were characterized by FT-IR, 1 H NMR, 13 C NMR, TGA, FESEM, charge density and ζ-potential. Kaolin suspension and effluent from paper mill were selected to evaluate the flocculation activity of the DCCs. Their flocculation performance was compared with that of commercial cationic polyacrylamide and poly aluminium chloride flocculants. The positive results showed that the NaOH/Urea solvent effectively promoted the dialdehyde cellulose (DAC) conversion to DCC in the one-step synthesis reaction. The DCCs with the carboxylate content more than 1 mmol/g exhibited steady flocculation performance to kaolin suspension in the broad pH range from 4 to 10. Its flocculation capacity to the effluent from paper mill also showed excellent

Structural basis for substrate activation and regulation by cystathionine beta-synthase (CBS) domains in cystathionine [beta]-synthase

Energy Technology Data Exchange (ETDEWEB)

Koutmos, Markos; Kabil, Omer; Smith, Janet L.; Banerjee, Ruma (Michigan-Med)

2011-08-17

The catalytic potential for H{sub 2}S biogenesis and homocysteine clearance converge at the active site of cystathionine {beta}-synthase (CBS), a pyridoxal phosphate-dependent enzyme. CBS catalyzes {beta}-replacement reactions of either serine or cysteine by homocysteine to give cystathionine and water or H{sub 2}S, respectively. In this study, high-resolution structures of the full-length enzyme from Drosophila in which a carbanion (1.70 {angstrom}) and an aminoacrylate intermediate (1.55 {angstrom}) have been captured are reported. Electrostatic stabilization of the zwitterionic carbanion intermediate is afforded by the close positioning of an active site lysine residue that is initially used for Schiff base formation in the internal aldimine and later as a general base. Additional stabilizing interactions between active site residues and the catalytic intermediates are observed. Furthermore, the structure of the regulatory 'energy-sensing' CBS domains, named after this protein, suggests a mechanism for allosteric activation by S-adenosylmethionine.

Genome-centric metatranscriptomes and ecological roles of the active microbial populations during cellulosic biomass anaerobic digestion.

Science.gov (United States)

Jia, Yangyang; Ng, Siu-Kin; Lu, Hongyuan; Cai, Mingwei; Lee, Patrick K H

2018-01-01

Although anaerobic digestion for biogas production is used worldwide in treatment processes to recover energy from carbon-rich waste such as cellulosic biomass, the activities and interactions among the microbial populations that perform anaerobic digestion deserve further investigations, especially at the population genome level. To understand the cellulosic biomass-degrading potentials in two full-scale digesters, this study examined five methanogenic enrichment cultures derived from the digesters that anaerobically digested cellulose or xylan for more than 2 years under 35 or 55 °C conditions. Metagenomics and metatranscriptomics were used to capture the active microbial populations in each enrichment culture and reconstruct their meta-metabolic network and ecological roles. 107 population genomes were reconstructed from the five enrichment cultures using a differential coverage binning approach, of which only a subset was highly transcribed in the metatranscriptomes. Phylogenetic and functional convergence of communities by enrichment condition and phase of fermentation was observed for the highly transcribed populations in the metatranscriptomes. In the 35 °C cultures grown on cellulose, Clostridium cellulolyticum -related and Ruminococcus -related bacteria were identified as major hydrolyzers and primary fermenters in the early growth phase, while Clostridium leptum -related bacteria were major secondary fermenters and potential fatty acid scavengers in the late growth phase. While the meta-metabolism and trophic roles of the cultures were similar, the bacterial populations performing each function were distinct between the enrichment conditions. Overall, a population genome-centric view of the meta-metabolism and functional roles of key active players in anaerobic digestion of cellulosic biomass was obtained. This study represents a major step forward towards understanding the microbial functions and interactions at population genome level during the

Isolation and functional characterization of a τ-cadinol synthase, a new sesquiterpene synthase from Lavandula angustifolia.

Science.gov (United States)

Jullien, Frédéric; Moja, Sandrine; Bony, Aurélie; Legrand, Sylvain; Petit, Cécile; Benabdelkader, Tarek; Poirot, Kévin; Fiorucci, Sébastien; Guitton, Yann; Nicolè, Florence; Baudino, Sylvie; Magnard, Jean-Louis

2014-01-01

In this paper we characterize three sTPSs: a germacrene D (LaGERDS), a (E)-β-caryophyllene (LaCARS) and a τ-cadinol synthase (LaCADS). τ-cadinol synthase is reported here for the first time and its activity was studied in several biological models including transiently or stably transformed tobacco species. Three dimensional structure models of LaCADS and Ocimum basilicum γ-cadinene synthase were built by homology modeling using the template structure of Gossypium arboreum δ-cadinene synthase. The depiction of their active site organization provides evidence of the global influence of the enzymes on the formation of τ-cadinol: instead of a unique amino-acid, the electrostatic properties and solvent accessibility of the whole active site in LaCADS may explain the stabilization of the cadinyl cation intermediate. Quantitative PCR performed from leaves and inflorescences showed two patterns of expression. LaGERDS and LaCARS were mainly expressed during early stages of flower development and, at these stages, transcript levels paralleled the accumulation of the corresponding terpene products (germacrene D and (E)-β-caryophyllene). By contrast, the expression level of LaCADS was constant in leaves and flowers. Phylogenetic analysis provided informative results on potential duplication process leading to sTPS diversification in lavender.

Characteristic of Hybrid Cellulose-Amino Functionalized POSS-Silica Nanocomposite and Antimicrobial Activity

Directory of Open Access Journals (Sweden)

Sivalingam Ramesh

2015-01-01

Full Text Available Recently, cellulose has much attention as an emerging renewable nanomaterial which holds promising properties having unique piezoelectricity, insulating, and biodegradable nature for various applications. Also, the modified properties of cellulose by appropriate chemical modifications in various functional groups with outstanding properties or significantly improved physical, chemical, biological, and electronic properties will widen the way for it to be utilized in different usages. Therefore, in this paper, cellulose-functionalized polyhedral oligomeric silsesquioxanes (POSS based materials were considered an important class of high-performance hybrid nanocomposite materials. To functionalize the regenerated cellulose, amino functionalized POSS material was synthesized via sol-gel covalent crosslinking process in presence of amino coupling agent. In this reaction, tetraethoxsilane (TEOS and γ-aminopropyltriethoxy silane (γ-APTES as coupling agent for metal precursors were selected. The chemical structure of cellulose-amine functionalized bonding and covalent crosslinking hybrids was confirmed by FTIR and 1H NMR spectral analysis. From the TEM results, well-dispersed hybrid cellulose-functionalized POSS-silica composites are observed. The resulting cellulose-POSS-silica hybrid nanocomposites materials provided significantly improved the optical transparency, and thermal and morphological properties to compare the cellulose-silica hybrid materials. Further, antimicrobial test against pathogenic bacteria was carried out.

Exogenous thyroid hormones regulate the activity of citrate synthase and cytochrome c oxidase in warm- but not cold-acclimated lake whitefish (Coregonus clupeaformis)

Science.gov (United States)

Zak, Megan A.; Regish, Amy M.; McCormick, Stephen; Manzon, Richard G.

2017-01-01

Thermal acclimation is known to elicit metabolic adjustments in ectotherms, but the cellular mechanisms and endocrine control of these shifts have not been fully elucidated. Here we examined the relationship between thermal acclimation, thyroid hormones and oxidative metabolism in juvenile lake whitefish. Impacts of thermal acclimation above (19 °C) or below (8 °C) the thermal optimum (13 °C) and exposure to exogenous thyroid hormone (60 µg T4/g body weight) were assessed by quantifying citrate synthase and cytochrome c oxidase activities in liver, red muscle, white muscle and heart. Warm acclimation decreased citrate synthase activity in liver and elevated both citrate synthase and cytochrome c oxidase activities in red muscle. In contrast, induction of hyperthyroidism in warm-acclimated fish stimulated a significant increase in liver citrate synthase and heart cytochrome c oxidase activities, and a decrease in the activity of both enzymes in red muscle. No change in citrate synthase or cytochrome c oxidase activities was observed following cold acclimation in either the presence or absence of exogenous thyroid hormones. Collectively, our results indicate that thyroid hormones influence the activity of oxidative enzymes more strongly in warm-acclimated than in cold-acclimated lake whitefish, and they may play a role in mediating metabolic adjustments observed during thermal acclimation.

Exogenous thyroid hormones regulate the activity of citrate synthase and cytochrome c oxidase in warm- but not cold-acclimated lake whitefish (Coregonus clupeaformis).

Science.gov (United States)

Zak, Megan A; Regish, Amy M; McCormick, Stephen D; Manzon, Richard G

2017-06-01

Thermal acclimation is known to elicit metabolic adjustments in ectotherms, but the cellular mechanisms and endocrine control of these shifts have not been fully elucidated. Here we examined the relationship between thermal acclimation, thyroid hormones and oxidative metabolism in juvenile lake whitefish. Impacts of thermal acclimation above (19°C) or below (8°C) the thermal optimum (13°C) and exposure to exogenous thyroid hormone (60µg T 4 /g body weight) were assessed by quantifying citrate synthase and cytochrome c oxidase activities in liver, red muscle, white muscle and heart. Warm acclimation decreased citrate synthase activity in liver and elevated both citrate synthase and cytochrome c oxidase activities in red muscle. In contrast, induction of hyperthyroidism in warm-acclimated fish stimulated a significant increase in liver citrate synthase and heart cytochrome c oxidase activities, and a decrease in the activity of both enzymes in red muscle. No change in citrate synthase or cytochrome c oxidase activities was observed following cold acclimation in either the presence or absence of exogenous thyroid hormones. Collectively, our results indicate that thyroid hormones influence the activity of oxidative enzymes more strongly in warm-acclimated than in cold-acclimated lake whitefish, and they may play a role in mediating metabolic adjustments observed during thermal acclimation. Copyright © 2017 Elsevier Inc. All rights reserved.

Assessing nano cellulose developments using science and technology indicators

International Nuclear Information System (INIS)

Milanez, Douglas Henrique; Amaral, Roniberto Morato do; Faria, Leandro Innocentini Lopes de; Gregolin, Jose Angelo Rodrigues

2013-01-01

This research aims to examine scientific and technological trends of developments in nano cellulose based on scientometric and patent indicators obtained from the Science Citation Index and Derwent Innovations Index in 2001-2010. The overall nano cellulose activity indicators were compared to nanotechnology and other selected nano materials. Scientific and technological future developments in nano cellulose were forecasted using extrapolation growth curves and the main countries were also mapped. The results showed that nano cellulose publications and patent documents have increased rapidly over the last five years with an average growth rate higher than that of nanotechnology and fullerene. The USA, Japan, France, Sweden and Finland all played a significant role in nano cellulose development and the extrapolation growth curves suggested that nano cellulose scientific and technological activities are still emerging. Finally, the evidence from this study recommends monitoring nano cellulose S and T advances in the coming years. (author)

Assessing nano cellulose developments using science and technology indicators

Energy Technology Data Exchange (ETDEWEB)

Milanez, Douglas Henrique; Amaral, Roniberto Morato do; Faria, Leandro Innocentini Lopes de; Gregolin, Jose Angelo Rodrigues, E-mail: douglasmilanez@yahoo.com.br [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil). Nucleo de Informacao Tecnologica em Materiais. Dept. de Engenharia de Materiais

2013-11-01

This research aims to examine scientific and technological trends of developments in nano cellulose based on scientometric and patent indicators obtained from the Science Citation Index and Derwent Innovations Index in 2001-2010. The overall nano cellulose activity indicators were compared to nanotechnology and other selected nano materials. Scientific and technological future developments in nano cellulose were forecasted using extrapolation growth curves and the main countries were also mapped. The results showed that nano cellulose publications and patent documents have increased rapidly over the last five years with an average growth rate higher than that of nanotechnology and fullerene. The USA, Japan, France, Sweden and Finland all played a significant role in nano cellulose development and the extrapolation growth curves suggested that nano cellulose scientific and technological activities are still emerging. Finally, the evidence from this study recommends monitoring nano cellulose S and T advances in the coming years. (author)

Structure and mechanism of the diterpene cyclase ent-copalyl diphosphate synthase

Energy Technology Data Exchange (ETDEWEB)

Köksal, Mustafa; Hu, Huayou; Coates, Robert M.; Peters, Reuben J.; Christianson, David W. (UIUC); (Iowa State); (Penn)

2011-09-20

The structure of ent-copalyl diphosphate synthase reveals three {alpha}-helical domains ({alpha}, {beta} and {gamma}), as also observed in the related diterpene cyclase taxadiene synthase. However, active sites are located at the interface of the {beta}{gamma} domains in ent-copalyl diphosphate synthase but exclusively in the {alpha} domain of taxadiene synthase. Modular domain architecture in plant diterpene cyclases enables the evolution of alternative active sites and chemical strategies for catalyzing isoprenoid cyclization reactions.

The relationship between skeletal muscle mitochondrial citrate synthase activity and whole body oxygen uptake adaptations in response to exercise training

DEFF Research Database (Denmark)

Vigelsø Hansen, Andreas; Andersen, Nynne Bjerre; Dela, Flemming

2014-01-01

Citrate synthase (CS) activity is a validated biomarker for mitochondrial density in skeletal muscle. CS activity is also used as a biochemical marker of the skeletal muscle oxidative adaptation to a training intervention, and a relationship between changes in whole body aerobic capacity and chan......Citrate synthase (CS) activity is a validated biomarker for mitochondrial density in skeletal muscle. CS activity is also used as a biochemical marker of the skeletal muscle oxidative adaptation to a training intervention, and a relationship between changes in whole body aerobic capacity...

Reduced ceramide synthase 2 activity causes progressive myoclonic epilepsy

DEFF Research Database (Denmark)

Mosbech, Mai-Britt; Olsen, Anne S B; Neess, Ditte

2014-01-01

between genes involved in SL metabolism and epilepsy. METHODS: We used quantitative real-time PCR, Western blotting, and enzymatic assays to determine the mRNA, protein, and activity levels of ceramide synthase 2 (CERS2) in fiibroblasts isolated from parental control subjects and from a patient diagnosed...... with progressive myoclonic epilepsy (PME). Mass spectrometry and fluorescence microscopy were used to examine the effects of reduced CERS2 activity on cellular lipid composition and plasma membrane functions. RESULTS: We identify a novel 27 kb heterozygous deletion including the CERS2 gene in a proband diagnosed...... with PME. Compared to parental controls, levels of CERS2 mRNA, protein, and activity were reduced by ˜50% in fibroblasts isolated from this proband, resulting in significantly reduced levels of ceramides and sphingomyelins containing the very long-chain fatty acids C24:0 and C26:0. The change in SL...

Enhanced Cellulose Degradation Using Cellulase-Nanosphere Complexes

Science.gov (United States)

Blanchette, Craig; Lacayo, Catherine I.; Fischer, Nicholas O.; Hwang, Mona; Thelen, Michael P.

2012-01-01

Enzyme catalyzed conversion of plant biomass to sugars is an inherently inefficient process, and one of the major factors limiting economical biofuel production. This is due to the physical barrier presented by polymers in plant cell walls, including semi-crystalline cellulose, to soluble enzyme accessibility. In contrast to the enzymes currently used in industry, bacterial cellulosomes organize cellulases and other proteins in a scaffold structure, and are highly efficient in degrading cellulose. To mimic this clustered assembly of enzymes, we conjugated cellulase obtained from Trichoderma viride to polystyrene nanospheres (cellulase:NS) and tested the hydrolytic activity of this complex on cellulose substrates from purified and natural sources. Cellulase:NS and free cellulase were equally active on soluble carboxymethyl cellulose (CMC); however, the complexed enzyme displayed a higher affinity in its action on microcrystalline cellulose. Similarly, we found that the cellulase:NS complex was more efficient in degrading natural cellulose structures in the thickened walls of cultured wood cells. These results suggest that nanoparticle-bound enzymes can improve catalytic efficiency on physically intractable substrates. We discuss the potential for further enhancement of cellulose degradation by physically clustering combinations of different glycosyl hydrolase enzymes, and applications for using cellulase:NS complexes in biofuel production. PMID:22870287

Enhanced cellulose degradation using cellulase-nanosphere complexes.

Directory of Open Access Journals (Sweden)

Craig Blanchette

Full Text Available Enzyme catalyzed conversion of plant biomass to sugars is an inherently inefficient process, and one of the major factors limiting economical biofuel production. This is due to the physical barrier presented by polymers in plant cell walls, including semi-crystalline cellulose, to soluble enzyme accessibility. In contrast to the enzymes currently used in industry, bacterial cellulosomes organize cellulases and other proteins in a scaffold structure, and are highly efficient in degrading cellulose. To mimic this clustered assembly of enzymes, we conjugated cellulase obtained from Trichoderma viride to polystyrene nanospheres (cellulase:NS and tested the hydrolytic activity of this complex on cellulose substrates from purified and natural sources. Cellulase:NS and free cellulase were equally active on soluble carboxymethyl cellulose (CMC; however, the complexed enzyme displayed a higher affinity in its action on microcrystalline cellulose. Similarly, we found that the cellulase:NS complex was more efficient in degrading natural cellulose structures in the thickened walls of cultured wood cells. These results suggest that nanoparticle-bound enzymes can improve catalytic efficiency on physically intractable substrates. We discuss the potential for further enhancement of cellulose degradation by physically clustering combinations of different glycosyl hydrolase enzymes, and applications for using cellulase:NS complexes in biofuel production.

Enhanced cellulose degradation using cellulase-nanosphere complexes.

Science.gov (United States)

Blanchette, Craig; Lacayo, Catherine I; Fischer, Nicholas O; Hwang, Mona; Thelen, Michael P

2012-01-01

Enzyme catalyzed conversion of plant biomass to sugars is an inherently inefficient process, and one of the major factors limiting economical biofuel production. This is due to the physical barrier presented by polymers in plant cell walls, including semi-crystalline cellulose, to soluble enzyme accessibility. In contrast to the enzymes currently used in industry, bacterial cellulosomes organize cellulases and other proteins in a scaffold structure, and are highly efficient in degrading cellulose. To mimic this clustered assembly of enzymes, we conjugated cellulase obtained from Trichoderma viride to polystyrene nanospheres (cellulase:NS) and tested the hydrolytic activity of this complex on cellulose substrates from purified and natural sources. Cellulase:NS and free cellulase were equally active on soluble carboxymethyl cellulose (CMC); however, the complexed enzyme displayed a higher affinity in its action on microcrystalline cellulose. Similarly, we found that the cellulase:NS complex was more efficient in degrading natural cellulose structures in the thickened walls of cultured wood cells. These results suggest that nanoparticle-bound enzymes can improve catalytic efficiency on physically intractable substrates. We discuss the potential for further enhancement of cellulose degradation by physically clustering combinations of different glycosyl hydrolase enzymes, and applications for using cellulase:NS complexes in biofuel production.

Preparation, Characterization and Activity of a Peptide-Cellulosic Aerogel Protease Sensor from Cotton

Directory of Open Access Journals (Sweden)

J. Vincent Edwards

2016-10-01

Full Text Available Nanocellulosic aerogels (NA provide a lightweight biocompatible material with structural properties, like interconnected high porosity and specific surface area, suitable for biosensor design. We report here the preparation, characterization and activity of peptide-nanocellulose aerogels (PepNA made from unprocessed cotton and designed with protease detection activity. Low-density cellulosic aerogels were prepared from greige cotton by employing calcium thiocyanate octahydrate/lithium chloride as a direct cellulose dissolving medium. Subsequent casting, coagulation, solvent exchange and supercritical carbon dioxide drying afforded homogeneous cellulose II aerogels of fibrous morphology. The cotton-based aerogel had a porosity of 99% largely dominated by mesopores (2–50 nm and an internal surface of 163 m2·g−1. A fluorescent tripeptide-substrate (succinyl-alanine-proline-alanine-4-amino-7-methyl-coumarin was tethered to NA by (1 esterification of cellulose C6 surface hydroxyl groups with glycidyl-fluorenylmethyloxycarbonyl (FMOC, (2 deprotection and (3 coupling of the immobilized glycine with the tripeptide. Characterization of the NA and PepNA included techniques, such as elemental analysis, mass spectral analysis, attenuated total reflectance infrared imaging, nitrogen adsorption, scanning electron microscopy and bioactivity studies. The degree of substitution of the peptide analog attached to the anhydroglucose units of PepNA was 0.015. The findings from mass spectral analysis and attenuated total reflectance infrared imaging indicated that the peptide substrate was immobilized on to the surface of the NA. Nitrogen adsorption revealed a high specific surface area and a highly porous system, which supports the open porous structure observed from scanning electron microscopy images. Bioactivity studies of PepNA revealed a detection sensitivity of 0.13 units/milliliter for human neutrophil elastase, a diagnostic biomarker for inflammatory

Tritium transfer studies in cellulose-HTO system

International Nuclear Information System (INIS)

Jayaraman, A.P.; Misra, B.M.

1986-01-01

This paper describes some aspects of studies on transfer of tritium to cellulose from tritiated water at six different specific activities and discusses the generalized tritiation pattern. Cellulose was irradiated in steps to 10 M Rads and the tritium transfer was determined at each stage. Experimental results signify substantial increase of tritiation in cellulose at higher dose of irradiation. (author). 8 refs

Cellulose microfibril deposition: coordinated activity at the plant plasma membrane

NARCIS (Netherlands)

Lindeboom, J.J.; Mulder, B.; Vos, J.W.; Ketelaar, M.J.; Emons, A.M.C.

2008-01-01

Plant cell wall production is a membrane-bound process. Cell walls are composed of cellulose microfibrils, embedded inside a matrix of other polysaccharides and glycoproteins. The cell wall matrix is extruded into the existing cell wall by exocytosis. This same process also inserts the cellulose

Cellulose Anionic Hydrogels Based on Cellulose Nanofibers As Natural Stimulants for Seed Germination and Seedling Growth.

Science.gov (United States)

Zhang, Hao; Yang, Minmin; Luan, Qian; Tang, Hu; Huang, Fenghong; Xiang, Xia; Yang, Chen; Bao, Yuping

2017-05-17

Cellulose anionic hydrogels were successfully prepared by dissolving TEMPO-oxidized cellulose nanofibers in NaOH/urea aqueous solution and being cross-linked with epichlorohydrin. The hydrogels exhibited microporous structure and high hydrophilicity, which contribute to the excellent water absorption property. The growth indexes, including the germination rate, root length, shoot length, fresh weight, and dry weight of the seedlings, were investigated. The results showed that cellulose anionic hydrogels with suitable carboxylate contents as plant growth regulators could be beneficial for seed germination and growth. Moreover, they presented preferable antifungal activity during the breeding and growth of the sesame seed breeding. Thus, the cellulose anionic hydrogels with suitable carboxylate contents could be applied as soilless culture mediums for plant growth. This research provided a simple and effective method for the fabrication of cellulose anionic hydrogel and evaluated its application in agriculture.

Cellulose- and xylan-degrading thermophilic anaerobic bacteria from biocompost.

Science.gov (United States)

Sizova, M V; Izquierdo, J A; Panikov, N S; Lynd, L R

2011-04-01

Nine thermophilic cellulolytic clostridial isolates and four other noncellulolytic bacterial isolates were isolated from self-heated biocompost via preliminary enrichment culture on microcrystalline cellulose. All cellulolytic isolates grew vigorously on cellulose, with the formation of either ethanol and acetate or acetate and formate as principal fermentation products as well as lactate and glycerol as minor products. In addition, two out of nine cellulolytic strains were able to utilize xylan and pretreated wood with roughly the same efficiency as for cellulose. The major products of xylan fermentation were acetate and formate, with minor contributions of lactate and ethanol. Phylogenetic analyses of 16S rRNA and glycosyl hydrolase family 48 (GH48) gene sequences revealed that two xylan-utilizing isolates were related to a Clostridium clariflavum strain and represent a distinct novel branch within the GH48 family. Both isolates possessed high cellulase and xylanase activity induced independently by either cellulose or xylan. Enzymatic activity decayed after growth cessation, with more-rapid disappearance of cellulase activity than of xylanase activity. A mixture of xylan and cellulose was utilized simultaneously, with a significant synergistic effect observed as a reduction of lag phase in cellulose degradation.

Cellulolytic activity of some cellulose-decomposing fungi in salinized soils

Directory of Open Access Journals (Sweden)

R. A. Badran

2014-08-01

Full Text Available Maximum evolution of CO2 was marked in control soil inoculated by tested fungi but its rate decreased with the increasing salinity. The period of 10 days was most suitable for cellulose degradation by A. niger and P. chrysoecnum and 15 days by A. flavus and C. globosum in control soil. High salinity levels affected greatly the cellulolylic activities of tesled fungi. Carbon content of saline soils increased white the nitrogen content decreased.

Arabidopsis CDS blastp result: AK110467 [KOME

Lifescience Database Archive (English)

Full Text Available AK110467 002-166-G08 At3g03050.1 cellulose synthase family protein (CslD3) similar to cellulose... synthase catalytic subunit gi:2827143 from [Arabidopsis thaliana], cellulose synthase-7 (gi:962

Current characterization methods for cellulose nanomaterials.

Science.gov (United States)

Foster, E Johan; Moon, Robert J; Agarwal, Umesh P; Bortner, Michael J; Bras, Julien; Camarero-Espinosa, Sandra; Chan, Kathleen J; Clift, Martin J D; Cranston, Emily D; Eichhorn, Stephen J; Fox, Douglas M; Hamad, Wadood Y; Heux, Laurent; Jean, Bruno; Korey, Matthew; Nieh, World; Ong, Kimberly J; Reid, Michael S; Renneckar, Scott; Roberts, Rose; Shatkin, Jo Anne; Simonsen, John; Stinson-Bagby, Kelly; Wanasekara, Nandula; Youngblood, Jeff

2018-04-23

A new family of materials comprised of cellulose, cellulose nanomaterials (CNMs), having properties and functionalities distinct from molecular cellulose and wood pulp, is being developed for applications that were once thought impossible for cellulosic materials. Commercialization, paralleled by research in this field, is fueled by the unique combination of characteristics, such as high on-axis stiffness, sustainability, scalability, and mechanical reinforcement of a wide variety of materials, leading to their utility across a broad spectrum of high-performance material applications. However, with this exponential growth in interest/activity, the development of measurement protocols necessary for consistent, reliable and accurate materials characterization has been outpaced. These protocols, developed in the broader research community, are critical for the advancement in understanding, process optimization, and utilization of CNMs in materials development. This review establishes detailed best practices, methods and techniques for characterizing CNM particle morphology, surface chemistry, surface charge, purity, crystallinity, rheological properties, mechanical properties, and toxicity for two distinct forms of CNMs: cellulose nanocrystals and cellulose nanofibrils.

Arabidopsis CDS blastp result: AK105393 [KOME

Lifescience Database Archive (English)

Full Text Available AK105393 001-123-B04 At5g16910.1 cellulose synthase family protein similar to gi:2827143 cellulose... synthase catalytic subunit, Arabidopsis thaliana, gi:9622886 cellulose synthase-7 from Zea mays 0.0 ...

Arabidopsis CDS blastp result: AK102695 [KOME

Lifescience Database Archive (English)

Full Text Available AK102695 J033103F21 At5g16910.1 cellulose synthase family protein similar to gi:2827143 cellulose... synthase catalytic subunit, Arabidopsis thaliana, gi:9622886 cellulose synthase-7 from Zea mays 0.0 ...

Arabidopsis CDS blastp result: AK100523 [KOME

Lifescience Database Archive (English)

Full Text Available AK100523 J023100P04 At5g16910.1 cellulose synthase family protein similar to gi:2827143 cellulose... synthase catalytic subunit, Arabidopsis thaliana, gi:9622886 cellulose synthase-7 from Zea mays 0.0 ...

Arabidopsis CDS blastp result: AK065259 [KOME

Lifescience Database Archive (English)

Full Text Available AK065259 J013002J18 At5g16910.1 cellulose synthase family protein similar to gi:2827143 cellulose... synthase catalytic subunit, Arabidopsis thaliana, gi:9622886 cellulose synthase-7 from Zea mays 0.0 ...

Arabidopsis CDS blastp result: AK102134 [KOME

Lifescience Database Archive (English)

Full Text Available AK102134 J033085F12 At5g16910.1 cellulose synthase family protein similar to gi:2827143 cellulose... synthase catalytic subunit, Arabidopsis thaliana, gi:9622886 cellulose synthase-7 from Zea mays 0.0 ...

Nitric oxide synthase expression and enzymatic activity in multiple sclerosis

DEFF Research Database (Denmark)

Broholm, H; Andersen, B; Wanscher, B

2004-01-01

We used post-mortem magnetic resonance imaging (MRI) guidance to obtain paired biopsies from the brains of four patients with clinical definite multiple sclerosis (MS). Samples were analyzed for the immunoreactivity (IR) of the three nitric oxide (NO) synthase isoforms [inducible, neuronal......NOS expressing cells in active lesions. NOS IR expressing cells were widely distributed in plaques, in white and gray matter that appeared normal macroscopically, and on MR. Endothelial NOS (eNOS) was highly expressed in intraparenchymal vascular endothelial cells of MS patients. A control group matched for age...

Paper Actuators Made with Cellulose and Hybrid Materials

OpenAIRE

Kim, Jaehwan; Yun, Sungryul; Mahadeva, Suresha K.; Yun, Kiju; Yang, Sang Yeol; Maniruzzaman, Mohammad

2010-01-01

Recently, cellulose has been re-discovered as a smart material that can be used as sensor and actuator materials, which is termed electro-active paper (EAPap). This paper reports recent advances in paper actuators made with cellulose and hybrid materials such as multi-walled carbon nanotubes, conducting polymers and ionic liquids. Two distinct actuator principles in EAPap actuators are demonstrated: piezoelectric effect and ion migration effect in cellulose. Piezoelectricity of cellulose EAPa...

Coffee-Driven Green Activation of Cellulose and Its Use for All-Paper Flexible Supercapacitors.

Science.gov (United States)

Lee, Donggue; Cho, Yoon-Gyo; Song, Hyun-Kon; Chun, Sang-Jin; Park, Sang-Bum; Choi, Don-Ha; Lee, Sun-Young; Yoo, JongTae; Lee, Sang-Young

2017-07-12

Cellulose, which is one of the most-abundant and -renewable natural resources, has been extensively explored as an alternative substance for electrode materials such as activated carbons. Here, we demonstrate a new class of coffee-mediated green activation of cellulose as a new environmentally benign chemical-activation strategy and its potential use for all-paper flexible supercapacitors. A piece of paper towel is soaked in espresso coffee (acting as a natural activating agent) and then pyrolyzed to yield paper-derived activated carbons (denoted as "EK-ACs"). Potassium ions (K + ), a core ingredient of espresso, play a viable role in facilitating pyrolysis kinetics and also in achieving a well-developed microporous structure in the EK-ACs. As a result, the EK-ACs show significant improvement in specific capacitance (131 F g -1 at a scan rate of 1.0 mV s -1 ) over control ACs (64 F g -1 ) obtained from the carbonization of a pristine paper towel. All-paper flexible supercapacitors are fabricated by assembling EK-ACs/carbon nanotube mixture-embedded paper towels (as electrodes), poly(vinyl alcohol)/KOH mixture-impregnated paper towels (as electrolytes), and polydimethylsiloxane-infiltrated paper towels (as packaging substances). The introduction of the EK-ACs (as an electrode material) and the paper towel (as a deformable and compliant substrate) enables the resulting all-paper supercapacitor to provide reliable and sustainable cell performance as well as exceptional mechanical flexibility. Notably, no appreciable loss in the cell capacitance is observed after repeated bending (over 5000 cycles) or multiple folding. The coffee-mediated green activation of cellulose and the resultant all-paper flexible supercapacitors open new material and system opportunities for eco-friendly high-performance flexible power sources.

Chrysanthemyl diphosphate synthase operates in planta as a bifunctional enzyme with chrysanthemol synthase activity

DEFF Research Database (Denmark)

Yang, Ting; Gao, Liping; Hu, Hao

2014-01-01

Chrysanthemyl diphosphate synthase (CDS) is the first path-way-specific enzyme in the biosynthesis of pyrethrins, the most widely used plant-derived pesticide. CDS catalyzes c1′-2-3 cyclopropanation reactions of two molecules of dimethylallyl diphosphate (DMAPP) to yield chrysanthemyl diphosphate...

Arabidopsis CDS blastp result: AK102766 [KOME

Lifescience Database Archive (English)

Full Text Available AK102766 J033107E04 At1g55850.1 cellulose synthase family protein similar to cellulose... synthase catalytic subunit [gi:13925881] from Nicotiana alata, cellulose synthase-5 [gi:9622882] from Zea mays 0.0 ...

Arabidopsis CDS blastp result: AK109812 [KOME

Lifescience Database Archive (English)

Full Text Available AK109812 002-147-H02 At5g16910.1 cellulose synthase family protein similar to gi:2827143 cellulose... synthase catalytic subunit, Arabidopsis thaliana, gi:9622886 cellulose synthase-7 from Zea mays 5e-90 ...

Arabidopsis CDS blastp result: AK110534 [KOME

Lifescience Database Archive (English)

Full Text Available AK110534 002-168-A07 At5g16910.1 cellulose synthase family protein similar to gi:2827143 cellulose... synthase catalytic subunit, Arabidopsis thaliana, gi:9622886 cellulose synthase-7 from Zea mays 1e-114 ...

Arabidopsis CDS blastp result: AK067424 [KOME

Lifescience Database Archive (English)

Full Text Available AK067424 J013107C16 At1g02730.1 cellulose synthase family protein similar to cellulose... synthase catalytic subunit [gi:13925881] from Nicotiana alata, cellulose synthase-4 [gi:9622880] from Zea mays 0.0 ...

Arabidopsis CDS blastp result: AK101487 [KOME

Lifescience Database Archive (English)

Full Text Available AK101487 J033042D19 At1g55850.1 cellulose synthase family protein similar to cellulose... synthase catalytic subunit [gi:13925881] from Nicotiana alata, cellulose synthase-5 [gi:9622882] from Zea mays 0.0 ...

Arabidopsis CDS blastp result: AK066835 [KOME

Lifescience Database Archive (English)

Full Text Available AK066835 J013087I16 At5g16910.1 cellulose synthase family protein similar to gi:2827143 cellulose... synthase catalytic subunit, Arabidopsis thaliana, gi:9622886 cellulose synthase-7 from Zea mays 1e-171 ...

Arabidopsis CDS blastp result: AK242601 [KOME

Lifescience Database Archive (English)

Full Text Available AK242601 J090014G03 At4g24000.1 68417.m03449 cellulose synthase family protein similar to cellulose... synthase from Gossypium hirsutum [gi:1706956], cellulose synthase-5 from Zea mays [gi:9622882] 2e-27 ...

Arabidopsis CDS blastp result: AK121003 [KOME

Lifescience Database Archive (English)

Full Text Available AK121003 J023045B21 At2g32540.1 cellulose synthase family protein similar to cellulose... synthase catalytic subunit from Arabidopsis thaliana [gi:5230423], cellulose synthase-5 from Zea mays [gi:9622882] 1e-167 ...

Arabidopsis CDS blastp result: AK103810 [KOME

Lifescience Database Archive (English)

Full Text Available AK103810 J033147A19 At1g55850.1 cellulose synthase family protein similar to cellulose... synthase catalytic subunit [gi:13925881] from Nicotiana alata, cellulose synthase-5 [gi:9622882] from Zea mays 1e-179 ...

Arabidopsis CDS blastp result: AK120054 [KOME

Lifescience Database Archive (English)

Full Text Available AK120054 J013000L05 At1g55850.1 cellulose synthase family protein similar to cellulose... synthase catalytic subunit [gi:13925881] from Nicotiana alata, cellulose synthase-5 [gi:9622882] from Zea mays 1e-148 ...

Arabidopsis CDS blastp result: AK069071 [KOME

Lifescience Database Archive (English)

Full Text Available AK069071 J023010H01 At2g32540.1 cellulose synthase family protein similar to cellulose... synthase catalytic subunit from Arabidopsis thaliana [gi:5230423], cellulose synthase-5 from Zea mays [gi:9622882] 1e-167 ...

Arabidopsis CDS blastp result: AK107881 [KOME

Lifescience Database Archive (English)

Full Text Available AK107881 002-134-D06 At1g55850.1 cellulose synthase family protein similar to cellulose... synthase catalytic subunit [gi:13925881] from Nicotiana alata, cellulose synthase-5 [gi:9622882] from Zea mays 5e-51 ...

Arabidopsis CDS blastp result: AK242601 [KOME

Lifescience Database Archive (English)

Full Text Available AK242601 J090014G03 At4g24000.1 68417.m03449 cellulose synthase family protein similar to cellulose... synthase from Gossypium hirsutum [gi:1706956], cellulose synthase-5 from Zea mays [gi:9622882] 5e-27 ...

Arabidopsis CDS blastp result: AK242585 [KOME

Lifescience Database Archive (English)

Full Text Available AK242585 J090010M20 At4g24000.1 68417.m03449 cellulose synthase family protein similar to cellulose... synthase from Gossypium hirsutum [gi:1706956], cellulose synthase-5 from Zea mays [gi:9622882] 1e-123 ...

Arabidopsis CDS blastp result: AK242890 [KOME

Lifescience Database Archive (English)

Full Text Available AK242890 J090079L19 At4g24000.1 68417.m03449 cellulose synthase family protein similar to cellulose... synthase from Gossypium hirsutum [gi:1706956], cellulose synthase-5 from Zea mays [gi:9622882] 4e-48 ...

Arabidopsis CDS blastp result: AK061162 [KOME

Lifescience Database Archive (English)

Full Text Available AK061162 006-209-A01 At2g32540.1 cellulose synthase family protein similar to cellulose... synthase catalytic subunit from Arabidopsis thaliana [gi:5230423], cellulose synthase-5 from Zea mays [gi:9622882] 3e-35 ...

Arabidopsis CDS blastp result: AK111344 [KOME

Lifescience Database Archive (English)

Full Text Available AK111344 002-181-F12 At1g55850.1 cellulose synthase family protein similar to cellulose... synthase catalytic subunit [gi:13925881] from Nicotiana alata, cellulose synthase-5 [gi:9622882] from Zea mays 2e-15 ...

Arabidopsis CDS blastp result: AK242601 [KOME

Lifescience Database Archive (English)

Full Text Available AK242601 J090014G03 At4g24000.1 68417.m03449 cellulose synthase family protein similar to cellulose... synthase from Gossypium hirsutum [gi:1706956], cellulose synthase-5 from Zea mays [gi:9622882] 4e-25 ...

Arabidopsis CDS blastp result: AK061639 [KOME

Lifescience Database Archive (English)

Full Text Available AK061639 001-036-B01 At1g55850.1 cellulose synthase family protein similar to cellulose... synthase catalytic subunit [gi:13925881] from Nicotiana alata, cellulose synthase-5 [gi:9622882] from Zea mays 4e-49 ...

Arabidopsis CDS blastp result: AK060286 [KOME

Lifescience Database Archive (English)

Full Text Available AK060286 001-006-C08 At2g32540.1 cellulose synthase family protein similar to cellulose... synthase catalytic subunit from Arabidopsis thaliana [gi:5230423], cellulose synthase-5 from Zea mays [gi:9622882] 6e-78 ...

Functional Analysis of Cellulose and Xyloglucan in the Walls of Stomatal Guard Cells of Arabidopsis1[OPEN

Science.gov (United States)

Rui, Yue; Anderson, Charles T.

2016-01-01

Stomatal guard cells are pairs of specialized epidermal cells that control water and CO2 exchange between the plant and the environment. To fulfill the functions of stomatal opening and closure that are driven by changes in turgor pressure, guard cell walls must be both strong and flexible, but how the structure and dynamics of guard cell walls enable stomatal function remains poorly understood. To address this question, we applied cell biological and genetic analyses to investigate guard cell walls and their relationship to stomatal function in Arabidopsis (Arabidopsis thaliana). Using live-cell spinning disk confocal microscopy, we measured the motility of cellulose synthase (CESA)-containing complexes labeled by green fluorescent protein (GFP)-CESA3 and observed a reduced proportion of GFP-CESA3 particles colocalizing with microtubules upon stomatal closure. Imaging cellulose organization in guard cells revealed a relatively uniform distribution of cellulose in the open state and a more fibrillar pattern in the closed state, indicating that cellulose microfibrils undergo dynamic reorganization during stomatal movements. In cesa3je5 mutants defective in cellulose synthesis and xxt1 xxt2 mutants lacking the hemicellulose xyloglucan, stomatal apertures, changes in guard cell length, and cellulose reorganization were aberrant during fusicoccin-induced stomatal opening or abscisic acid-induced stomatal closure, indicating that sufficient cellulose and xyloglucan are required for normal guard cell dynamics. Together, these results provide new insights into how guard cell walls allow stomata to function as responsive mediators of gas exchange at the plant surface. PMID:26729799

Evolutionary and mechanistic insights from the reconstruction of α-humulene synthases from a modern (+)-germacrene A synthase.

Science.gov (United States)

Gonzalez, Veronica; Touchet, Sabrina; Grundy, Daniel J; Faraldos, Juan A; Allemann, Rudolf K

2014-10-15

Germacrene A synthase (GAS) from Solidago canadensis catalyzes the conversion of farnesyl diphosphate (FDP) to the plant sesquiterpene (+)-germacrene A. After diphosphate expulsion, farnesyl cation reacts with the distal 10,11-double bond to afford germacrene A (>96%) and <2% α-humulene, which arises from 1,11-cyclization of FDP. The origin of the 1,11-activity of GAS was investigated by amino acid sequence alignments of 1,10- and 1,11-synthases and comparisons of X-ray crystal structures with the homology model of GAS; a triad [Thr 401-Gly 402-Gly 403] that might be responsible for the predominant 1,10-cyclization activity of GAS was identified. Replacement of Gly 402 with residues of increasing size led to a progressive increase of 1,11-cyclization. The catalytic robustness of these 1,10- /1,11-GAS variants point to Gly 402 as a functional switch of evolutionary significance and suggests that enzymes with strict functionalities have evolved from less specific ancestors through a small number of substitutions. Similar results were obtained with germacrene D synthase (GDS) upon replacement of the homologous active-site residue Gly 404: GDS-G404V generated approximately 20% bicyclogermacrene, a hydrocarbon with a cyclopropane ring that underlines the dual 1,10-/1,11-cyclization activity of this mutant. This suggests that the reaction pathways to germacrenes and humulenes might be connected through a bridged 1,10,11-carbocation intermediate or transition state that resembles bicyclogermacrene. Mechanistic studies using [1-(3)H1]-10-fluorofarnesyl diphosphate and deuterium-labeling experiments with [12,13-(2)H6]-FDP support a germacrene-humulene rearrangement linking 1,10- and 1,11-pathways. These results support the bioinformatics proposal that modern 1,10-synthases could have evolved from promiscuous 1,11-sesquiterpene synthases.

Cyclic GMP-AMP Synthase is Activated by Double-stranded DNA-Induced Oligomerization

OpenAIRE

Li, Xin; Shu, Chang; Yi, Guanghui; Chaton, Catherine T.; Shelton, Catherine L.; Diao, Jiasheng; Zuo, Xiaobing; Kao, C Cheng; Herr, Andrew B.; Li, Pingwei

2013-01-01

Cyclic GMP-AMP synthase (cGAS) is a cytosolic DNA sensor mediating innate antimicrobial immunity. It catalyzes the synthesis of a noncanonical cyclic dinucleotide 2′,5′ cGAMP that binds to STING and mediates the activation of TBK1 and IRF-3. Activated IRF-3 translocates to the nucleus and initiates the transcription of the IFN-β gene. The structure of mouse cGAS bound to an 18 bp dsDNA revealed that cGAS interacts with dsDNA through two binding sites, forming a 2:2 complex. Enzyme assays and ...

Paper actuators made with cellulose and hybrid materials.

Science.gov (United States)

Kim, Jaehwan; Yun, Sungryul; Mahadeva, Suresha K; Yun, Kiju; Yang, Sang Yeol; Maniruzzaman, Mohammad

2010-01-01

Recently, cellulose has been re-discovered as a smart material that can be used as sensor and actuator materials, which is termed electro-active paper (EAPap). This paper reports recent advances in paper actuators made with cellulose and hybrid materials such as multi-walled carbon nanotubes, conducting polymers and ionic liquids. Two distinct actuator principles in EAPap actuators are demonstrated: piezoelectric effect and ion migration effect in cellulose. Piezoelectricity of cellulose EAPap is quite comparable with other piezoelectric polymers. But, it is biodegradable, biocompatible, mechanically strong and thermally stable. To enhance ion migration effect in the cellulose, polypyrrole conducting polymer and ionic liquids were nanocoated on the cellulose film. This hybrid cellulose EAPap nanocomposite exhibits durable bending actuation in an ambient humidity and temperature condition. Fabrication, characteristics and performance of the cellulose EAPap and its hybrid EAPap materials are illustrated. Also, its possibility for remotely microwave-driven paper actuator is demonstrated.

The cellulose-binding activity of the PsB multiprotein complex is required for proper assembly of the spore coat and spore viability in Dictyostelium discoideum.

Science.gov (United States)

Srinivasan, S; Griffiths, K R; McGuire, V; Champion, A; Williams, K L; Alexander, S

2000-08-01

The terminal event of spore differentiation in the cellular slime mould Dictyostelium discoideum is the assembly of the spore coat, which surrounds the dormant amoeba and allows the organism to survive during extended periods of environmental stress. The spore coat is a polarized extracellular matrix composed of glycoproteins and cellulose. The process of spore coat formation begins by the regulated secretion of spore coat proteins from the prespore vesicles (PSVs). Four of the major spore coat proteins (SP96, PsB/SP85, SP70 and SP60) exist as a preassembled multiprotein complex within the PSVs. This complete complex has an endogenous cellulose-binding activity. Mutant strains lacking either the SP96 or SP70 proteins produce partial complexes that do not have cellulose-binding activity, while mutants lacking SP60 produce a partial complex that retains this activity. Using a combination of immunofluorescence microscopy and biochemical methods we now show that the lack of cellulose-binding activity in the SP96 and SP70 mutants results in abnormally assembled spore coats and spores with greatly reduced viability. In contrast, the SP60 mutant, in which the PsB complex retains its cellulose-binding activity, produces spores with apparently unaltered structure and viability. Thus, it is the loss of the cellulose-binding activity of the PsB complex, rather than the mere loss of individual spore coat proteins, that results in compromised spore coat structure. These results support the idea that the cellulose-binding activity associated with the complete PsB complex plays an active role in the assembly of the spore coat.

Arabidopsis CDS blastp result: AK242601 [KOME

Lifescience Database Archive (English)

Full Text Available AK242601 J090014G03 At4g38190.1 68417.m05391 cellulose synthase family protein similar to cellulose... synthase catalytic subunit gi:2827143 from [Arabidopsis thaliana], cellulose synthase-5 (gi:9622882) from Zea mays 0.0 ...

Arabidopsis CDS blastp result: AK242601 [KOME

Lifescience Database Archive (English)

Full Text Available AK242601 J090014G03 At1g32180.1 68414.m03958 cellulose synthase family protein similar to cellulose... synthase catalytic subunit gi:2827143 from [Arabidopsis thaliana], cellulose synthase-9 (gi:9622890) from Zea mays 0.0 ...

Arabidopsis CDS blastp result: AK242890 [KOME

Lifescience Database Archive (English)

Full Text Available AK242890 J090079L19 At1g02730.1 68414.m00226 cellulose synthase family protein similar to cellulose... synthase catalytic subunit [gi:13925881] from Nicotiana alata, cellulose synthase-4 [gi:9622880] from Zea mays 1e-131 ...

Arabidopsis CDS blastp result: AK242585 [KOME

Lifescience Database Archive (English)

Full Text Available AK242585 J090010M20 At4g38190.1 68417.m05391 cellulose synthase family protein similar to cellulose... synthase catalytic subunit gi:2827143 from [Arabidopsis thaliana], cellulose synthase-5 (gi:9622882) from Zea mays 8e-63 ...

Arabidopsis CDS blastp result: AK242601 [KOME

Lifescience Database Archive (English)

Full Text Available AK242601 J090014G03 At4g23990.1 68417.m03448 cellulose synthase family protein similar to cellulose... synthase catalytic subunit from Arabidopsis thaliana [gi:5230423], cellulose synthase-5 from Zea mays [gi:9622882] 2e-26 ...

Arabidopsis CDS blastp result: AK242601 [KOME

Lifescience Database Archive (English)

Full Text Available AK242601 J090014G03 At1g02730.1 68414.m00226 cellulose synthase family protein similar to cellulose... synthase catalytic subunit [gi:13925881] from Nicotiana alata, cellulose synthase-4 [gi:9622880] from Zea mays 0.0 ...

Arabidopsis CDS blastp result: AK242585 [KOME

Lifescience Database Archive (English)

Full Text Available AK242585 J090010M20 At1g02730.1 68414.m00226 cellulose synthase family protein similar to cellulose... synthase catalytic subunit [gi:13925881] from Nicotiana alata, cellulose synthase-4 [gi:9622880] from Zea mays 7e-27 ...

Arabidopsis CDS blastp result: AK242601 [KOME

Lifescience Database Archive (English)

Full Text Available AK242601 J090014G03 At1g55850.1 68414.m06405 cellulose synthase family protein similar to cellulose... synthase catalytic subunit [gi:13925881] from Nicotiana alata, cellulose synthase-5 [gi:9622882] from Zea mays 2e-22 ...

Arabidopsis CDS blastp result: AK242890 [KOME

Lifescience Database Archive (English)

Full Text Available AK242890 J090079L19 At2g32540.1 68415.m03975 cellulose synthase family protein similar to cellulose... synthase catalytic subunit from Arabidopsis thaliana [gi:5230423], cellulose synthase-5 from Zea mays [gi:9622882] 4e-47 ...

Arabidopsis CDS blastp result: AK242601 [KOME

Lifescience Database Archive (English)

Full Text Available AK242601 J090014G03 At2g32540.1 68415.m03975 cellulose synthase family protein similar to cellulose... synthase catalytic subunit from Arabidopsis thaliana [gi:5230423], cellulose synthase-5 from Zea mays [gi:9622882] 3e-31 ...

GenBank blastx search result: AK287855 [KOME

Lifescience Database Archive (English)

Full Text Available AK287855 J065196O16 AB091060.1 AB091060 Gluconacetobacter xylinus acsAB, acsC, acsD genes for cellulose... synthase subunit AB, cellulose synthase subunit C, cellulose synthase subunit D, complete cds. BCT 4e-15 0 ...

GenBank blastx search result: AK242831 [KOME

Lifescience Database Archive (English)

Full Text Available AK242831 J090067L08 AB091060.1 AB091060 Gluconacetobacter xylinus acsAB, acsC, acsD genes for cellulose... synthase subunit AB, cellulose synthase subunit C, cellulose synthase subunit D, complete cds. BCT 1e-14 1 ...

Arabidopsis CDS blastp result: AK242585 [KOME

Lifescience Database Archive (English)

Full Text Available AK242585 J090010M20 At5g16910.1 68418.m01982 cellulose synthase family protein similar to gi:2827143 cellulo...se synthase catalytic subunit, Arabidopsis thaliana, gi:9622886 cellulose synthase-7 from Zea mays 1e-28 ...

Arabidopsis CDS blastp result: AK242601 [KOME

Lifescience Database Archive (English)

Full Text Available AK242601 J090014G03 At4g23990.1 68417.m03448 cellulose synthase family protein similar to cellulose... synthase catalytic subunit from Arabidopsis thaliana [gi:5230423], cellulose synthase-5 from Zea mays [gi:9622882] 8e-25 ...

Arabidopsis CDS blastp result: AK242890 [KOME

Lifescience Database Archive (English)

Full Text Available AK242890 J090079L19 At1g32180.1 68414.m03958 cellulose synthase family protein similar to cellulose... synthase catalytic subunit gi:2827143 from [Arabidopsis thaliana], cellulose synthase-9 (gi:9622890) from Zea mays 1e-126 ...

Arabidopsis CDS blastp result: AK242890 [KOME

Lifescience Database Archive (English)

Full Text Available AK242890 J090079L19 At4g23990.1 68417.m03448 cellulose synthase family protein similar to cellulose... synthase catalytic subunit from Arabidopsis thaliana [gi:5230423], cellulose synthase-5 from Zea mays [gi:9622882] 1e-45 ...

Arabidopsis CDS blastp result: AK242601 [KOME

Lifescience Database Archive (English)

Full Text Available AK242601 J090014G03 At4g23990.1 68417.m03448 cellulose synthase family protein similar to cellulose... synthase catalytic subunit from Arabidopsis thaliana [gi:5230423], cellulose synthase-5 from Zea mays [gi:9622882] 5e-25 ...

Arabidopsis CDS blastp result: AK242585 [KOME

Lifescience Database Archive (English)

Full Text Available AK242585 J090010M20 At5g16910.1 68418.m01982 cellulose synthase family protein similar to gi:2827143 cellulo...se synthase catalytic subunit, Arabidopsis thaliana, gi:9622886 cellulose synthase-7 from Zea mays 2e-65 ...

Arabidopsis CDS blastp result: AK242585 [KOME

Lifescience Database Archive (English)

Full Text Available AK242585 J090010M20 At1g32180.1 68414.m03958 cellulose synthase family protein similar to cellulose... synthase catalytic subunit gi:2827143 from [Arabidopsis thaliana], cellulose synthase-9 (gi:9622890) from Zea mays 1e-24 ...

Arabidopsis CDS blastp result: AK242601 [KOME

Lifescience Database Archive (English)

Full Text Available AK242601 J090014G03 At2g32530.1 68415.m03974 cellulose synthase family protein similar to cellulose... synthase catalytic subunit from Arabidopsis thaliana [gi:5230423], cellulose synthase-5 from Zea mays [gi:9622882] 2e-29 ...

Arabidopsis CDS blastp result: AK242585 [KOME

Lifescience Database Archive (English)

Full Text Available AK242585 J090010M20 At1g32180.1 68414.m03958 cellulose synthase family protein similar to cellulose... synthase catalytic subunit gi:2827143 from [Arabidopsis thaliana], cellulose synthase-9 (gi:9622890) from Zea mays 3e-66 ...

Arabidopsis CDS blastp result: AK242585 [KOME

Lifescience Database Archive (English)

Full Text Available AK242585 J090010M20 At4g23990.1 68417.m03448 cellulose synthase family protein similar to cellulose... synthase catalytic subunit from Arabidopsis thaliana [gi:5230423], cellulose synthase-5 from Zea mays [gi:9622882] 1e-124 ...

Arabidopsis CDS blastp result: AK242601 [KOME

Lifescience Database Archive (English)

Full Text Available AK242601 J090014G03 At2g32540.1 68415.m03975 cellulose synthase family protein similar to cellulose... synthase catalytic subunit from Arabidopsis thaliana [gi:5230423], cellulose synthase-5 from Zea mays [gi:9622882] 2e-45 ...

Arabidopsis CDS blastp result: AK242890 [KOME

Lifescience Database Archive (English)

Full Text Available AK242890 J090079L19 At5g16910.1 68418.m01982 cellulose synthase family protein similar to gi:2827143 cellulo...se synthase catalytic subunit, Arabidopsis thaliana, gi:9622886 cellulose synthase-7 from Zea mays 1e-130 ...

Arabidopsis CDS blastp result: AK242890 [KOME

Lifescience Database Archive (English)

Full Text Available AK242890 J090079L19 At4g38190.1 68417.m05391 cellulose synthase family protein similar to cellulose... synthase catalytic subunit gi:2827143 from [Arabidopsis thaliana], cellulose synthase-5 (gi:9622882) from Zea mays 1e-125 ...

Arabidopsis CDS blastp result: AK242585 [KOME

Lifescience Database Archive (English)

Full Text Available AK242585 J090010M20 At2g32540.1 68415.m03975 cellulose synthase family protein similar to cellulose... synthase catalytic subunit from Arabidopsis thaliana [gi:5230423], cellulose synthase-5 from Zea mays [gi:9622882] 4e-98 ...

Arabidopsis CDS blastp result: AK242601 [KOME

Lifescience Database Archive (English)

Full Text Available AK242601 J090014G03 At1g55850.1 68414.m06405 cellulose synthase family protein similar to cellulose... synthase catalytic subunit [gi:13925881] from Nicotiana alata, cellulose synthase-5 [gi:9622882] from Zea mays 1e-61 ...

Arabidopsis CDS blastp result: AK242601 [KOME

Lifescience Database Archive (English)

Full Text Available AK242601 J090014G03 At5g16910.1 68418.m01982 cellulose synthase family protein similar to gi:2827143 cellulo...se synthase catalytic subunit, Arabidopsis thaliana, gi:9622886 cellulose synthase-7 from Zea mays 0.0 ...

Arabidopsis CDS blastp result: AK242585 [KOME

Lifescience Database Archive (English)

Full Text Available AK242585 J090010M20 At2g32530.1 68415.m03974 cellulose synthase family protein similar to cellulose... synthase catalytic subunit from Arabidopsis thaliana [gi:5230423], cellulose synthase-5 from Zea mays [gi:9622882] 8e-98 ...

Arabidopsis CDS blastp result: AK242585 [KOME

Lifescience Database Archive (English)

Full Text Available AK242585 J090010M20 At4g38190.1 68417.m05391 cellulose synthase family protein similar to cellulose... synthase catalytic subunit gi:2827143 from [Arabidopsis thaliana], cellulose synthase-5 (gi:9622882) from Zea mays 4e-27 ...

Arabidopsis CDS blastp result: AK242585 [KOME

Lifescience Database Archive (English)

Full Text Available AK242585 J090010M20 At1g02730.1 68414.m00226 cellulose synthase family protein similar to cellulose... synthase catalytic subunit [gi:13925881] from Nicotiana alata, cellulose synthase-4 [gi:9622880] from Zea mays 1e-69 ...

Arabidopsis CDS blastp result: AK242585 [KOME

Lifescience Database Archive (English)

Full Text Available AK242585 J090010M20 At1g55850.1 68414.m06405 cellulose synthase family protein similar to cellulose... synthase catalytic subunit [gi:13925881] from Nicotiana alata, cellulose synthase-5 [gi:9622882] from Zea mays 0.0 ...

Arabidopsis CDS blastp result: AK242890 [KOME

Lifescience Database Archive (English)

Full Text Available AK242890 J090079L19 At1g55850.1 68414.m06405 cellulose synthase family protein similar to cellulose... synthase catalytic subunit [gi:13925881] from Nicotiana alata, cellulose synthase-5 [gi:9622882] from Zea mays 1e-52 ...

Arabidopsis CDS blastp result: AK242890 [KOME

Lifescience Database Archive (English)

Full Text Available AK242890 J090079L19 At2g32530.1 68415.m03974 cellulose synthase family protein similar to cellulose... synthase catalytic subunit from Arabidopsis thaliana [gi:5230423], cellulose synthase-5 from Zea mays [gi:9622882] 4e-50 ...

Arabidopsis CDS blastp result: AK242601 [KOME

Lifescience Database Archive (English)

Full Text Available AK242601 J090014G03 At2g32530.1 68415.m03974 cellulose synthase family protein similar to cellulose... synthase catalytic subunit from Arabidopsis thaliana [gi:5230423], cellulose synthase-5 from Zea mays [gi:9622882] 5e-48 ...

Production of activated carbon from cellulosic fibers for environment protection

International Nuclear Information System (INIS)

Le Coq, L.; Faur, C.; Le Cloirec, P.; Phan Ngoc, H.

2005-01-01

Activated carbon fibers (ACF) have received an increasing attention in recent years as an adsorbent for purifying polluted gaseous and aqueous streams. Their preparation, characterization and application have been reported in many studies [1], which show that the porosity of ACF is dependent on activation conditions, as temperature, time or gas. ACF provide adsorption rates 2 to 50 times higher than Granular Activated Carbon [2], because of their low diameter (∼10 m) providing a larger external surface area in contact with the fluid compared with that of granules. Furthermore, their potential for the removal of various pollutants from water was demonstrated towards micro-organics like phenols [3], pesticides or dyes [4]. Generally, fibrous activated carbons are produced from natural or synthetic precursors by carbonization at 600-1000 C followed by an activation step by CO 2 oe steam at higher temperature [2]. Another way to produce the fibrous activated carbons is chemical activation with H 3 PO 4 , HNO 3 , KOH...[5]. Different types of synthetic or natural fibers have been used as precursors of fibrous activated carbons since 1970: polyacrylonitrile (PAN), polyphenol, rayon, cellulose phosphate, pitch, etc. Each of them has its own applications and limitations. The synthetic fibers being generally expensive, it would be interesting to find out low-cost precursors from local material resources. This work is a part of a research exchange program between the Vietnamese National Center of Natural Sciences and Technology (Vietnam) and the Ecole des Mines de Nantes (Gepea, France), with the aim to find some economical solutions for water treatment. Fibrous activated carbons are produced from natural cellulose fibers, namely jute and coconut fibers, which are abundant in Vietnam as well as in other tropical countries, have a low ash content and a low cost in comparison with synthetic fibers. Two methods are compared to produce activated carbons: 1) a physical

Trichothecenes induce accumulation of glucosylceramide in neural cells by interfering with lactosylceramide synthase activity

International Nuclear Information System (INIS)

Kralj, Ana; Gurgui, Mihaela; Koenig, Gabriele M.; Echten-Deckert, Gerhild van

2007-01-01

Trichothecenes are sesquiterpenoid metabolites produced by several fungal strains that impair human and animal health. Since sphingolipids were connected with fungal toxicity the aim of the present study was to test the influence of fungal metabolites on sphingolipid metabolism in neural cells. The crude extract of fungal strain Spicellum roseum induced accumulation of glucosylceramide (GlcCer), and simultaneous reduction of the formation of lactosylceramide (LacCer) and complex gangliosides in primary cultured neurons. Following a bioassay-guided fractionation of the respective fungal extract we could demonstrate that the two isolated trichothecene derivatives, 8-deoxy-trichothecin (8-dT) and trichodermol (Td-ol) were responsible for this effect. Thus, incubation of primary cultured neurons as well as of neuroblastoma B104 cells for 24 h with 30 μM of either of the two fungal metabolites resulted in uncoupling of sphingolipid biosynthesis at the level of LacCer. For the observed reduction of LacCer synthase activity by about 90% cell integrity was crucial in both cell types. In neuroblastoma cells the amount of LacCer synthase mRNA was reduced in the presence of trichothecenes, whereas in primary cultured neurons this was not the case, suggesting a post-transcriptional mechanism of action in the latter cell type. The data also show that the compounds did not interfere with the translocation of GlcCer in neuroblastoma cells. Collectively, our results demonstrate that trichodermol and 8-deoxy-trichothecin inhibit LacCer synthase activity in a cell-type-specific manner

Effects and mechanism of acid rain on plant chloroplast ATP synthase.

Science.gov (United States)

Sun, Jingwen; Hu, Huiqing; Li, Yueli; Wang, Lihong; Zhou, Qing; Huang, Xiaohua

2016-09-01

Acid rain can directly or indirectly affect plant physiological functions, especially photosynthesis. The enzyme ATP synthase is the key in photosynthetic energy conversion, and thus, it affects plant photosynthesis. To clarify the mechanism by which acid rain affects photosynthesis, we studied the effects of acid rain on plant growth, photosynthesis, chloroplast ATP synthase activity and gene expression, chloroplast ultrastructure, intracellular H(+) level, and water content of rice seedlings. Acid rain at pH 4.5 remained the chloroplast structure unchanged but increased the expression of six chloroplast ATP synthase subunits, promoted chloroplast ATP synthase activity, and increased photosynthesis and plant growth. Acid rain at pH 4.0 or less decreased leaf water content, destroyed chloroplast structure, inhibited the expression of six chloroplast ATP synthase subunits, decreased chloroplast ATP synthase activity, and reduced photosynthesis and plant growth. In conclusion, acid rain affected the chloroplast ultrastructure, chloroplast ATPase transcription and activity, and P n by changing the acidity in the cells, and thus influencing the plant growth and development. Finally, the effects of simulated acid rain on the test indices were found to be dose-dependent.

Cellulose is not just cellulose

DEFF Research Database (Denmark)

Hidayat, Budi Juliman; Felby, Claus; Johansen, Katja Salomon

2012-01-01

are not regions where free cellulose ends are more abundant than in the bulk cell wall. In more severe cases cracks between fibrils form at dislocations and it is possible that the increased accessibility that these cracks give is the reason why hydrolysis of cellulose starts at these locations. If acid...... or enzymatic hydrolysis of plant cell walls is carried out simultaneously with the application of shear stress, plant cells such as fibers or tracheids break at their dislocations. At present it is not known whether specific carbohydrate binding modules (CBMs) and/or cellulases preferentially access cellulose...

NCBI nr-aa BLAST: CBRC-DDIS-01-0132 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-DDIS-01-0132 ref|XP_646256.1| cellulose synthase [Dictyostelium discoideum AX4...] gb|AAF00200.1|AF163835_1 cellulose synthase [Dictyostelium discoideum] gb|EAL71912.1| cellulose synthase [Dictyostelium discoideum AX4] XP_646256.1 0.0 99% ...

Enantiospecific (+)- and (-)-germacrene D synthases, cloned from goldenrod, reveal a functionally active variant of the universal isoprenoid-biosynthesis aspartate-rich motif.

Science.gov (United States)

Prosser, Ian; Altug, Iris G; Phillips, Andy L; König, Wilfried A; Bouwmeester, Harro J; Beale, Michael H

2004-12-15

The naturally occurring, volatile sesquiterpene hydrocarbon germacrene D has strong effects on insect behaviour and genes encoding enzymes that produce this compound are of interest in the study of plant-insect interactions and in a number of biotechnological approaches to pest control. Goldenrod, Solidago canadensis, is unusual in that it produces both enantiomers of germacrene D. Two new sesquiterpene synthase cDNAs, designated Sc11 and Sc19, have been isolated from goldenrod and functional expression in Escherichia coli identified Sc11 as (+)-germacrene D synthase and Sc19 as (-)-germacrene D synthase. Thus, the enantiomers of germacrene D are the products of separate, but closely related (85% amino-acid identity), enzymes. Unlike other sesquiterpene synthases and the related monoterpene synthases and prenyl transferases, which contain the characteristic amino-acid motif DDXX(D,E), Sc11 is unusual in that this motif occurs as (303)NDTYD. Mutagenesis of this motif to (303)DDTYD gave rise to an enzyme that fully retained (+)-germacrene D synthase activity. The converse mutation in Sc19 (D303N) resulted in a less efficient but functional enzyme. Mutagenesis of position 303 to glutamate in both enzymes resulted in loss of activity. These results indicate that the magnesium ion-binding role of the first aspartate in the DDXXD motif may not be as critical as previously thought. Further amino-acid sequence comparisons and molecular modelling of the enzyme structures revealed that very subtle changes to the active site of this family of enzymes are required to alter the reaction pathway to form, in this case, different enantiomers from the same enzyme-bound carbocationic intermediate.

Pronounced between-subject and circadian variability in thymidylate synthase and dihydropyrimidine dehydrogenase enzyme activity in human volunteers

NARCIS (Netherlands)

Jacobs, Bart A W; Deenen, Maarten J; Pluim, Dick; van Hasselt, J G Coen; Krähenbühl, Martin D; van Geel, Robin M J M; de Vries, Niels; Rosing, Hilde; Meulendijks, Didier; Burylo, Artur M; Cats, Annemieke; Beijnen, Jos H; Huitema, Alwin D R; Schellens, Jan H M

AIMS: The enzymatic activity of dihydropyrimidine dehydrogenase (DPD) and thymidylate synthase (TS) are important for the tolerability and efficacy of the fluoropyrimidine drugs. In the present study, we explored between-subject variability (BSV) and circadian rhythmicity in DPD and TS activity in

Fatty Acid Synthase Activity as a Target for c-Met Driven Prostate Cancer

Science.gov (United States)

2013-07-01

cancer potentially due to increased fecal fat excretion. In addition, several families of plant-derived flavonoid compounds including...Apoptosis by Flavonoids Is Associated with Their Ability to Inhibit Fatty Acid Synthase Activity. J. Biol. Chem., 2005. 280(7): p. 5636-5645. 156... flavonoids , represent a source of relatively nontoxic, orally available and affordable compounds that are known to affect a number of different

Imidazopyridine-Based Fatty Acid Synthase Inhibitors That Show Anti-HCV Activity and in Vivo Target Modulation.

Science.gov (United States)

Oslob, Johan D; Johnson, Russell J; Cai, Haiying; Feng, Shirley Q; Hu, Lily; Kosaka, Yuko; Lai, Julie; Sivaraja, Mohanram; Tep, Samnang; Yang, Hanbiao; Zaharia, Cristiana A; Evanchik, Marc J; McDowell, Robert S

2013-01-10

Potent imidazopyridine-based inhibitors of fatty acid synthase (FASN) are described. The compounds are shown to have antiviral (HCV replicon) activities that track with their biochemical activities. The most potent analogue (compound 19) also inhibits rat FASN and inhibits de novo palmitate synthesis in vitro (cell-based) as well as in vivo.

Metaproteomics of cellulose methanisation under thermophilic conditions reveals a surprisingly high proteolytic activity.

Science.gov (United States)

Lü, Fan; Bize, Ariane; Guillot, Alain; Monnet, Véronique; Madigou, Céline; Chapleur, Olivier; Mazéas, Laurent; He, Pinjing; Bouchez, Théodore

2014-01-01

Cellulose is the most abundant biopolymer on Earth. Optimising energy recovery from this renewable but recalcitrant material is a key issue. The metaproteome expressed by thermophilic communities during cellulose anaerobic digestion was investigated in microcosms. By multiplying the analytical replicates (65 protein fractions analysed by MS/MS) and relying solely on public protein databases, more than 500 non-redundant protein functions were identified. The taxonomic community structure as inferred from the metaproteomic data set was in good overall agreement with 16S rRNA gene tag pyrosequencing and fluorescent in situ hybridisation analyses. Numerous functions related to cellulose and hemicellulose hydrolysis and fermentation catalysed by bacteria related to Caldicellulosiruptor spp. and Clostridium thermocellum were retrieved, indicating their key role in the cellulose-degradation process and also suggesting their complementary action. Despite the abundance of acetate as a major fermentation product, key methanogenesis enzymes from the acetoclastic pathway were not detected. In contrast, enzymes from the hydrogenotrophic pathway affiliated to Methanothermobacter were almost exclusively identified for methanogenesis, suggesting a syntrophic acetate oxidation process coupled to hydrogenotrophic methanogenesis. Isotopic analyses confirmed the high dominance of the hydrogenotrophic methanogenesis. Very surprising was the identification of an abundant proteolytic activity from Coprothermobacter proteolyticus strains, probably acting as scavenger and/or predator performing proteolysis and fermentation. Metaproteomics thus appeared as an efficient tool to unravel and characterise metabolic networks as well as ecological interactions during methanisation bioprocesses. More generally, metaproteomics provides direct functional insights at a limited cost, and its attractiveness should increase in the future as sequence databases are growing exponentially.

Cellulose-Based Nanomaterials for Energy Applications.

Science.gov (United States)

Wang, Xudong; Yao, Chunhua; Wang, Fei; Li, Zhaodong

2017-11-01

Cellulose is the most abundant natural polymer on earth, providing a sustainable green resource that is renewable, degradable, biocompatible, and cost effective. Recently, nanocellulose-based mesoporous structures, flexible thin films, fibers, and networks are increasingly developed and used in photovoltaic devices, energy storage systems, mechanical energy harvesters, and catalysts components, showing tremendous materials science value and application potential in many energy-related fields. In this Review, the most recent advancements of processing, integration, and application of cellulose nanomaterials in the areas of solar energy harvesting, energy storage, and mechanical energy harvesting are reviewed. For solar energy harvesting, promising applications of cellulose-based nanostructures for both solar cells and photoelectrochemical electrodes development are reviewed, and their morphology-related merits are discussed. For energy storage, the discussion is primarily focused on the applications of cellulose-based nanomaterials in lithium-ion batteries, including electrodes (e.g., active materials, binders, and structural support), electrolytes, and separators. Applications of cellulose nanomaterials in supercapacitors are also reviewed briefly. For mechanical energy harvesting, the most recent technology evolution in cellulose-based triboelectric nanogenerators is reviewed, from fundamental property tuning to practical implementations. At last, the future research potential and opportunities of cellulose nanomaterials as a new energy material are discussed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Metal active site elasticity linked to activation of homocysteine in methionine synthases

Energy Technology Data Exchange (ETDEWEB)

Koutmos, Markos; Pejchal, Robert; Bomer, Theresa M.; Matthews, Rowena G.; Smith, Janet L.; Ludwig, Martha L. (Michigan)

2008-04-02

Enzymes possessing catalytic zinc centers perform a variety of fundamental processes in nature, including methyl transfer to thiols. Cobalamin-independent (MetE) and cobalamin-dependent (MetH) methionine synthases are two such enzyme families. Although they perform the same net reaction, transfer of a methyl group from methyltetrahydrofolate to homocysteine (Hcy) to form methionine, they display markedly different catalytic strategies, modular organization, and active site zinc centers. Here we report crystal structures of zinc-replete MetE and MetH, both in the presence and absence of Hcy. Structural investigation of the catalytic zinc sites of these two methyltransferases reveals an unexpected inversion of zinc geometry upon binding of Hcy and displacement of an endogenous ligand in both enzymes. In both cases a significant movement of the zinc relative to the protein scaffold accompanies inversion. These structures provide new information on the activation of thiols by zinc-containing enzymes and have led us to propose a paradigm for the mechanism of action of the catalytic zinc sites in these and related methyltransferases. Specifically, zinc is mobile in the active sites of MetE and MetH, and its dynamic nature helps facilitate the active site conformational changes necessary for thiol activation and methyl transfer.

Several genes encoding enzymes with the same activity are necessary for aerobic fungal degradation of cellulose in nature.

Directory of Open Access Journals (Sweden)

Peter K Busk

Full Text Available The cellulose-degrading fungal enzymes are glycoside hydrolases of the GH families and lytic polysaccharide monooxygenases. The entanglement of glycoside hydrolase families and functions makes it difficult to predict the enzymatic activity of glycoside hydrolases based on their sequence. In the present study we further developed the method Peptide Pattern Recognition to an automatic approach not only to find all genes encoding glycoside hydrolases and lytic polysaccharide monooxygenases in fungal genomes but also to predict the function of the genes. The functional annotation is an important feature as it provides a direct route to predict function from primary sequence. Furthermore, we used Peptide Pattern Recognition to compare the cellulose-degrading enzyme activities encoded by 39 fungal genomes. The results indicated that cellobiohydrolases and AA9 lytic polysaccharide monooxygenases are hallmarks of cellulose-degrading fungi except brown rot fungi. Furthermore, a high number of AA9, endocellulase and β-glucosidase genes were identified, not in what are known to be the strongest, specialized lignocellulose degraders but in saprophytic fungi that can use a wide variety of substrates whereas only few of these genes were found in fungi that have a limited number of natural, lignocellulotic substrates. This correlation suggests that enzymes with different properties are necessary for degradation of cellulose in different complex substrates. Interestingly, clustering of the fungi based on their predicted enzymes indicated that Ascomycota and Basidiomycota use the same enzymatic activities to degrade plant cell walls.

Prevalence and trends of cellulosics in pharmaceutical dosage forms.

Science.gov (United States)

Mastropietro, David J; Omidian, Hossein

2013-02-01

Many studies have shown that cellulose derivatives (cellulosics) can provide various benefits when used in virtually all types of dosage forms. Nevertheless, the popularity of their use in approved drug products is rather unknown. This research reports the current prevalence and trends of use for 15 common cellulosics in prescription drug products. The cellulosics were powdered and microcrystalline cellulose (MCC), ethyl cellulose, hydroxypropyl cellulose (HPC), hydroxyethyl cellulose (HEC), hypromellose (HPMC), HPMC phthalate, HPMC acetate succinate, cellulose acetate (CA), CA phthalate, sodium (Na) and calcium (Ca) carboxymethylcellulose (CMC), croscarmellose sodium (XCMCNa), methyl cellulose, and low substituted HPC. The number of brand drug products utilizing each cellulosics was determined using the online drug index Rxlist. A total of 607 brand products were identified having one or more of the cellulosics as an active or inactive ingredient. An array of various dosage forms was identified and revealed HPMC and MCC to be the most utilized cellulosics in all products followed by XCMCNa and HPC. Many products contained two or more cellulosics in the formulation (42% containing two, 23% containing three, and 4% containing 4-5). The largest combination occurrence was HPMC with MCC. The use of certain cellulosics within different dosage form types was found to contain specific trends. All injectables utilized only CMCNa, and the same with all ophthalmic solutions utilizing HPMC, and otic suspensions utilizing HEC. Popularity and trends regarding cellulosics use may occur based on many factors including functionality, safety, availability, stability, and ease of manufacturing.

Synthesis and characterization of cellulose derivatives obtained from bacterial cellulose

International Nuclear Information System (INIS)

Oliveira, Rafael L. de; Barud, Hernane; Ribeiro, Sidney J.L.; Messaddeq, Younes

2011-01-01

The chemical modification of cellulose leads to production of derivatives with different properties from those observed for the original cellulose, for example, increased solubility in more traditional solvents. In this work we synthesized four derivatives of cellulose: microcrystalline cellulose, cellulose acetate, methylcellulose and carboxymethylcellulose using bacterial cellulose as a source. These were characterized in terms of chemical and structural changes by examining the degree of substitution (DS), infrared spectroscopy (FTIR) and nuclear magnetic resonance spectroscopy - NMR 13 C. The molecular weight and degree of polymerization were evaluated by viscometry. The characterization of the morphology of materials and thermal properties were performed with the techniques of X-ray diffraction, electron microscopy images, differential scanning calorimetry (DSC) and thermogravimetric analysis. (author)

Chitosan Based Regenerated Cellulose Fibers Functionalized with Plasma and Ultrasound

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Urška Vrabič Brodnjak

2018-04-01

Full Text Available The great potential of regenerated cellulose fibers, which offer excellent possibilities as a matrix for the design of bioactive materials, was the lead for our research. We focused on the surface modification of fibers to improve the sorption properties of regenerated cellulose and biocomposite regenerated cellulose/chitosan fibers, which are on the market. The purpose of our investigation was also the modification of regenerated cellulose fibers with the functionalization by chitosan as a means of obtaining similar properties to biocomposite regenerated cellulose/chitosan fibers on the market. Argon gas plasma was used for fiber surface activation and chitosan adsorption. Ultrasound was also used as a treatment procedure for the surface activation of regenerated cellulose fibers and treatment with chitosan. Analyses have shown that ultrasonic energy or plasma change the accessibility of free functional groups, structure and reactivity, especially in regenerated cellulose fibers. Changes that occurred in the morphology and in the structure of fibers were also reflected in their physical and chemical properties. Consequently, moisture content, sorption properties and water retention improved.

Bacillus caldolyticus prs gene encoding phosphoribosyldiphosphate synthase

DEFF Research Database (Denmark)

Krath, Britta N.; Hove-Jensen, Bjarne

1996-01-01

The prs gene, encoding phosphoribosyl-diphosphate (PRPP) synthase, as well as the flanking DNA sequences were cloned and sequenced from the Gram-positive thermophile, Bacillus caldolyticus. Comparison with the homologous sequences from the mesophile, Bacillus subtilis, revealed a gene (gca......D) encoding N-acetylglucosamine-l-phosphate uridyltransferase upstream of prs, and a gene homologous to ctc downstream of prs. cDNA synthesis with a B. caldolyticus gcaD-prs-ctc-specified mRNA as template, followed by amplification utilising the polymerase chain reaction indicated that the three genes are co......-transcribed. Comparison of amino acid sequences revealed a high similarity among PRPP synthases across a wide phylogenetic range. An E. coli strain harbouring the B. caldolyticus prs gene in a multicopy plasmid produced PRPP synthase activity 33-fold over the activity of a haploid B. caldolyticus strain. B. caldolyticus...

The role of nitric oxide in aspirin induced thrombolysis in vitro and the purification of aspirin activated nitric oxide synthase from human blood platelets.

Science.gov (United States)

Karmohapatra, Soumendra K; Chakraborty, Kushal; Kahn, Nighat N; Sinha, Asru K

2007-11-01

Aspirin, a well-known inhibitor of platelet aggregation, is extensively used for the prevention/treatment of coronary artery disease. The beneficial and antithrombotic effects of the compound are related to the inhibition of platelet cyclooxygenase. It is currently believed that aspirin has no effect on the formed thrombus, which results in coronary artery disease. It was found that the exposure of platelets to 4.0 microM aspirin either in vitro or in vivo resulted in fibrinolysis of the formed "clot" produced by the recalcification of platelet-rich plasma due to the production of NO in these cells by the compound. The lysis of clot in the presence of aspirin was found to be related to the fibrinolysis with simultaneous appearance of fibrin degradation products due to the generation of serine proteinase activity by NO in the assay mixture. The aspirin activated nitric oxide synthase that catalyzed the synthesis of NO in platelets was solubilized by Triton X-100 treatment and purified to homogeneity by chromatography on DEAE cellulose and Sephadex G-50 columns. The enzyme was found to be a single chain polypeptide with M.W. 19 kDa. The treatment of human plasminogen with NO was found to directly activate the zymogen to plasmin with the production of preactivation peptide in the absence of cofactors, or cells without the formation of cyclic GMP in the assay mixture. (c) 2007 Wiley-Liss, Inc.

Enhancement of Cellulose Degradation by Cattle Saliva

Science.gov (United States)

Seki, Yasutaka; Kikuchi, Yukiko; Kimura, Yoshihiro; Yoshimoto, Ryo; Takahashi, Masatoshi; Aburai, Kenichi; Kanai, Yoshihiro; Ruike, Tatsushi; Iwabata, Kazuki; Sugawara, Fumio; Sakai, Hideki; Abe, Masahiko; Sakaguchi, Kengo

2015-01-01

Saccharification of cellulose is a promising technique for producing alternative source of energy. However, the efficiency of conversion of cellulose into soluble sugar using any currently available methodology is too low for industrial application. Many additives, such as surfactants, have been shown to enhance the efficiency of cellulose-to-sugar conversion. In this study, we have examined first whether cattle saliva, as an additive, would enhance the cellulase-catalyzed hydrolysis of cellulose, and subsequently elucidated the mechanism by which cattle saliva enhanced this conversion. Although cattle saliva, by itself, did not degrade cellulose, it enhanced the cellulase-catalyzed degradation of cellulose. Thus, the amount of reducing sugar produced increased approximately 2.9-fold by the addition of cattle saliva. We also found that non-enzymatic proteins, which were present in cattle saliva, were responsible for causing the enhancement effect. Third, the mechanism of cattle saliva mediated enhancement of cellulase activity was probably similar to that of the canonical surfactants. Cattle saliva is available in large amounts easily and cheaply, and it can be used without further purification. Thus, cattle saliva could be a promising additive for efficient saccharification of cellulose on an industrial scale. PMID:26402242

Influence of Tableting on Enzymatic Activity of Papain along with Determination of Its Percolation Threshold with Microcrystalline Cellulose

Science.gov (United States)

Sharma, Manu; Sharma, Vinay; Majumdar, Dipak K.

2014-01-01

The binary mixture tablets of papain and microcrystalline cellulose (MCC), dicalcium phosphate dihydrate (DCP), carrageenan, tragacanth, and agar were prepared by direct compression. Carrageenan, tragacanth, and agar provided maximum protection to enzyme activity compared to MCC and DCP. However, stability studies indicated highest loss of enzyme activity with carrageenan, tragacanth, and agar. Therefore, compression behaviour of different binary mixtures of papain with MCC at different compaction pressures, that is, 40–280 MPa, was studied according to Heckel equation. The compressibility studies of binary mixtures indicated brittle behavior of papain. The application of percolation theory on the relationship between critical density as a function of enzyme activity and mixture composition revealed the presence of percolation threshold for binary mixture. Papain-MCC mixture composition showed significant percolation threshold at 18.48% (w/w) papain loading. Microcrystalline cellulose provided higher protection during stability study. However, higher concentrations of microcrystalline cellulose, probably as dominant particles, do not protect the enzyme with their plastic deformation. Below the percolation threshold, that is, 18.48% (w/w) papain amount in mixture with plastic excipient, activity loss increases strongly because of higher shearing forces during compaction due to system dominance of plastic particles. This mixture range should therefore be avoided to get robust formulation of papain. PMID:27350972

Structural Basis of Catalysis in the Bacterial Monoterpene Synthases Linalool Synthase and 1,8-Cineole Synthase

OpenAIRE

Karuppiah, Vijaykumar; Ranaghan, Kara E.; Leferink, Nicole G. H.; Johannissen, Linus O.; Shanmugam, Muralidharan; Ní Cheallaigh, Aisling; Bennett, Nathan J.; Kearsey, Lewis J.; Takano, Eriko; Gardiner, John M.; van der Kamp, Marc W.; Hay, Sam; Mulholland, Adrian J.; Leys, David; Scrutton, Nigel S.

2017-01-01

Terpenoids form the largest and stereochemically most diverse class of natural products, and there is considerable interest in producing these by biocatalysis with whole cells or purified enzymes, and by metabolic engineering. The monoterpenes are an important class of terpenes and are industrially important as flavors and fragrances. We report here structures for the recently discovered Streptomyces clavuligerus monoterpene synthases linalool synthase (bLinS) and 1,8-cineole synthase (bCinS)...

INFLUENCE OF CELLULOSE POLYMERIZATION DEGREE AND CRYSTALLINITY ON KINETICS OF CELLULOSE DEGRADATION

OpenAIRE

Edita Jasiukaitytė-Grojzdek,; Matjaž Kunaver,; Ida Poljanšek

2012-01-01

Cellulose was treated in ethylene glycol with p-toluene sulfonic acid monohydrate as a catalyst at different temperatures. At the highest treatment temperature (150 °C) liquefaction of wood pulp cellulose was achieved and was dependant on cellulose polymerization degree (DP). Furthermore, the rate of amorphous cellulose weight loss was found to increase with cellulose degree of polymerization, while the rate of crystalline cellulose weight loss was reciprocal to the size of the crystallites. ...

Expression Patterns, Activities and Carbohydrate-Metabolizing Regulation of Sucrose Phosphate Synthase, Sucrose Synthase and Neutral Invertase in Pineapple Fruit during Development and Ripening

Science.gov (United States)

Zhang, Xiu-Mei; Wang, Wei; Du, Li-Qing; Xie, Jiang-Hui; Yao, Yan-Li; Sun, Guang-Ming

2012-01-01

Differences in carbohydrate contents and metabolizing-enzyme activities were monitored in apical, medial, basal and core sections of pineapple (Ananas comosus cv. Comte de paris) during fruit development and ripening. Fructose and glucose of various sections in nearly equal amounts were the predominant sugars in the fruitlets, and had obvious differences until the fruit matured. The large rise of sucrose/hexose was accompanied by dramatic changes in sucrose phosphate synthase (SPS) and sucrose synthase (SuSy) activities. By contrast, neutral invertase (NI) activity may provide a mechanism to increase fruit sink strength by increasing hexose concentrations. Furthermore, two cDNAs of Ac-sps (accession no. GQ996582) and Ac-ni (accession no. GQ996581) were first isolated from pineapple fruits utilizing conserved amino-acid sequences. Homology alignment reveals that the amino acid sequences contain some conserved function domains. Transcription expression analysis of Ac-sps, Ac-susy and Ac-ni also indicated distinct patterns related to sugar accumulation and composition of pineapple fruits. It suggests that differential expressions of multiple gene families are necessary for sugar metabolism in various parts and developmental stages of pineapple fruit. A cycle of sucrose breakdown in the cytosol of sink tissues could be mediated through both Ac-SuSy and Ac-NI, and Ac-NI could be involved in regulating crucial steps by generating sugar signals to the cells in a temporally and spatially restricted fashion. PMID:22949808

Biofunctional Paper via Covalent Modification of Cellulose

Science.gov (United States)

Yu, Arthur; Shang, Jing; Cheng, Fang; Paik, Bradford A.; Kaplan, Justin M.; Andrade, Rodrigo B.; Ratner, Daniel M.

2012-01-01

Paper-based analytical devices are the subject of growing interest for the development of low-cost point-of-care diagnostics, environmental monitoring technologies and research tools for limited-resource settings. However, there are limited chemistries available for the conjugation of biomolecules to cellulose for use in biomedical applications. Herein, divinyl sulfone (DVS) chemistry was demonstrated to covalently immobilize small molecules, proteins and DNA onto the hydroxyl groups of cellulose membranes through nucleophilic addition. Assays on modified cellulose using protein-carbohydrate and protein-glycoprotein interactions as well as oligonucleotide hybridization showed that the membrane’s bioactivity was specific, dose-dependent, and stable over a long period of time. Use of an inkjet printer to form patterns of biomolecules on DVS-activated cellulose illustrates the adaptability of the DVS functionalization technique to pattern sophisticated designs, with potential applications in cellulose-based lateral flow devices. PMID:22708701

Cellulose-Hemicellulose Interactions at Elevated Temperatures Increase Cellulose Recalcitrance to Biological Conversion

Energy Technology Data Exchange (ETDEWEB)

Mittal, Ashutosh [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Himmel, Michael E [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Kumar, Rajeev [University of California, Riverside; Oak Ridge National Laboratory; ; Smith, Micholas Dean [Oak Ridge National Laboratory; University of Tennessee; Petridis, Loukas [Oak Ridge National Laboratory; University of Tennessee; Ong, Rebecca G. [Michigan Technological University; Cai, Charles M. [University of California, Riverside; Oak Ridge National Laboratory; Balan, Venkatesh [University of Houston; Dale, Bruce E. [Michigan State University; Ragauskas, Arthur J. [Oak Ridge National Laboratory; University of Tennessee; Smith, Jeremy C. [Oak Ridge National Laboratory; University of Tennessee; Wyman, Charles E. [University of California, Riverside; Oak Ridge National Laboratory

2018-01-23

It has been previously shown that cellulose-lignin droplets' strong interactions, resulting from lignin coalescence and redisposition on cellulose surface during thermochemical pretreatments, increase cellulose recalcitrance to biological conversion, especially at commercially viable low enzyme loadings. However, information on the impact of cellulose-hemicellulose interactions on cellulose recalcitrance following relevant pretreatment conditions are scarce. Here, to investigate the effects of plausible hemicellulose precipitation and re-association with cellulose on cellulose conversion, different pretreatments were applied to pure Avicel(R) PH101 cellulose alone and Avicel mixed with model hemicellulose compounds followed by enzymatic hydrolysis of resulting solids at both low and high enzyme loadings. Solids produced by pretreatment of Avicel mixed with hemicelluloses (AMH) were found to contain about 2 to 14.6% of exogenous, precipitated hemicelluloses and showed a remarkably much lower digestibility (up to 60%) than their respective controls. However, the exogenous hemicellulosic residues that associated with Avicel following high temperature pretreatments resulted in greater losses in cellulose conversion than those formed at low temperatures, suggesting that temperature plays a strong role in the strength of cellulose-hemicellulose association. Molecular dynamics simulations of hemicellulosic xylan and cellulose were found to further support this temperature effect as the xylan-cellulose interactions were found to substantially increase at elevated temperatures. Furthermore, exogenous, precipitated hemicelluloses in pretreated AMH solids resulted in a larger drop in cellulose conversion than the delignified lignocellulosic biomass containing comparably much higher natural hemicellulose amounts. Increased cellulase loadings or supplementation of cellulase with xylanases enhanced cellulose conversion for most pretreated AMH solids; however, this approach

Degradation of cellulosic substances by Thermomonospora curvata

Energy Technology Data Exchange (ETDEWEB)

Stutzenberger, F J

1979-05-01

Research is reported on the cellulolytic activity of Thermomonospora curvata, a thermophilic cellulolytic actinomycete prevalent in municipal solid waste compost. Various cellulosic wastes were evaluated for their potential for the induction of cellulase synthesis by Th. curvata and the extent of cellulose degradation under optimal culture conditions. All the substrates tested showed significant degradation of their cellulose content with the exception of sawdust and barley straw. In contrast to Trichoderma viride, cotton fibers were the best substrates for both C/sub 1/ and C/sub x/ cellulase production. Further research is recommended. (JSR)

A Comparison of the Effects of Neuronal Nitric Oxide Synthase and Inducible Nitric Oxide Synthase Inhibition on Cartilage Damage

Directory of Open Access Journals (Sweden)

Nevzat Selim Gokay

2016-01-01

Full Text Available The objective of this study was to investigate the effects of selective inducible nitric oxide synthase and neuronal nitric oxide synthase inhibitors on cartilage regeneration. The study involved 27 Wistar rats that were divided into five groups. On Day 1, both knees of 3 rats were resected and placed in a formalin solution as a control group. The remaining 24 rats were separated into 4 groups, and their right knees were surgically damaged. Depending on the groups, the rats were injected with intra-articular normal saline solution, neuronal nitric oxide synthase inhibitor 7-nitroindazole (50 mg/kg, inducible nitric oxide synthase inhibitor amino-guanidine (30 mg/kg, or nitric oxide precursor L-arginine (200 mg/kg. After 21 days, the right and left knees of the rats were resected and placed in formalin solution. The samples were histopathologically examined by a blinded evaluator and scored on 8 parameters. Although selective neuronal nitric oxide synthase inhibition exhibited significant (P=0.044 positive effects on cartilage regeneration following cartilage damage, it was determined that inducible nitric oxide synthase inhibition had no statistically significant effect on cartilage regeneration. It was observed that the nitric oxide synthase activation triggered advanced arthrosis symptoms, such as osteophyte formation. The fact that selective neuronal nitric oxide synthase inhibitors were observed to have mitigating effects on the severity of the damage may, in the future, influence the development of new agents to be used in the treatment of cartilage disorders.

Practical screening of purified cellobiohydrolases and endoglucanases with α-cellulose and specification of hydrodynamics

Directory of Open Access Journals (Sweden)

Jäger Gernot

2010-08-01

Full Text Available Abstract Background It is important to generate biofuels and society must be weaned from its dependency on fossil fuels. In order to produce biofuels, lignocellulose is pretreated and the resulting cellulose is hydrolyzed by cellulases such as cellobiohydrolases (CBH and endoglucanases (EG. Until now, the biofuel industry has usually applied impractical celluloses to screen for cellulases capable of degrading naturally occurring, insoluble cellulose. This study investigates how these cellulases adsorb and hydrolyze insoluble α-cellulose − considered to be a more practical substrate which mimics the alkaline-pretreated biomass used in biorefineries. Moreover, this study investigates how hydrodynamics affects cellulase adsorption and activity onto α-cellulose. Results First, the cellulases CBH I, CBH II, EG I and EG II were purified from Trichoderma reesei and CBH I and EG I were utilized in order to study and model the adsorption isotherms (Langmuir and kinetics (pseudo-first-order. Second, the adsorption kinetics and cellulase activities were studied under different hydrodynamic conditions, including liquid mixing and particle suspension. Third, in order to compare α-cellulose with three typically used celluloses, the exact cellulase activities towards all four substrates were measured. It was found that, using α-cellulose, the adsorption models fitted to the experimental data and yielded parameters comparable to those for filter paper. Moreover, it was determined that higher shaking frequencies clearly improved the adsorption of cellulases onto α-cellulose and thus bolstered their activity. Complete suspension of α-cellulose particles was the optimal operating condition in order to ensure efficient cellulase adsorption and activity. Finally, all four purified cellulases displayed comparable activities only on insoluble α-cellulose. Conclusions α-Cellulose is an excellent substrate to screen for CBHs and EGs. This current investigation

Structure/Function Analysis of Cotton-Based Peptide-Cellulose Conjugates: Spatiotemporal/Kinetic Assessment of Protease Aerogels Compared to Nanocrystalline and Paper Cellulose

Directory of Open Access Journals (Sweden)

J. Vincent Edwards

2018-03-01

Full Text Available Nanocellulose has high specific surface area, hydration properties, and ease of derivatization to prepare protease sensors. A Human Neutrophil Elastase sensor designed with a nanocellulose aerogel transducer surface derived from cotton is compared with cotton filter paper, and nanocrystalline cellulose versions of the sensor. X-ray crystallography was employed along with Michaelis–Menten enzyme kinetics, and circular dichroism to contrast the structure/function relations of the peptide-cellulose conjugate conformation to enzyme/substrate binding and turnover rates. The nanocellulosic aerogel was found to have a cellulose II structure. The spatiotemporal relation of crystallite surface to peptide-cellulose conformation is discussed in light of observed enzyme kinetics. A higher substrate binding affinity (Km of elastase was observed with the nanocellulose aerogel and nanocrystalline peptide-cellulose conjugates than with the solution-based elastase substrate. An increased Km observed for the nanocellulosic aerogel sensor yields a higher enzyme efficiency (kcat/Km, attributable to binding of the serine protease to the negatively charged cellulose surface. The effect of crystallite size and β-turn peptide conformation are related to the peptide-cellulose kinetics. Models demonstrating the orientation of cellulose to peptide O6-hydroxymethyl rotamers of the conjugates at the surface of the cellulose crystal suggest the relative accessibility of the peptide-cellulose conjugates for enzyme active site binding.

Structure/Function Analysis of Cotton-Based Peptide-Cellulose Conjugates: Spatiotemporal/Kinetic Assessment of Protease Aerogels Compared to Nanocrystalline and Paper Cellulose

Science.gov (United States)

Edwards, J. Vincent; Fontenot, Krystal; Liebner, Falk; Pircher, Nicole Doyle nee; French, Alfred D.; Condon, Brian D.

2018-01-01

Nanocellulose has high specific surface area, hydration properties, and ease of derivatization to prepare protease sensors. A Human Neutrophil Elastase sensor designed with a nanocellulose aerogel transducer surface derived from cotton is compared with cotton filter paper, and nanocrystalline cellulose versions of the sensor. X-ray crystallography was employed along with Michaelis–Menten enzyme kinetics, and circular dichroism to contrast the structure/function relations of the peptide-cellulose conjugate conformation to enzyme/substrate binding and turnover rates. The nanocellulosic aerogel was found to have a cellulose II structure. The spatiotemporal relation of crystallite surface to peptide-cellulose conformation is discussed in light of observed enzyme kinetics. A higher substrate binding affinity (Km) of elastase was observed with the nanocellulose aerogel and nanocrystalline peptide-cellulose conjugates than with the solution-based elastase substrate. An increased Km observed for the nanocellulosic aerogel sensor yields a higher enzyme efficiency (kcat/Km), attributable to binding of the serine protease to the negatively charged cellulose surface. The effect of crystallite size and β-turn peptide conformation are related to the peptide-cellulose kinetics. Models demonstrating the orientation of cellulose to peptide O6-hydroxymethyl rotamers of the conjugates at the surface of the cellulose crystal suggest the relative accessibility of the peptide-cellulose conjugates for enzyme active site binding. PMID:29534033

Identification and Characterization of Non-Cellulose-Producing Mutants of Gluconacetobacter hansenii Generated by Tn5 Transposon Mutagenesis

Science.gov (United States)

Deng, Ying; Nagachar, Nivedita; Xiao, Chaowen; Tien, Ming

2013-01-01

The acs operon of Gluconacetobacter is thought to encode AcsA, AcsB, AcsC, and AcsD proteins that constitute the cellulose synthase complex, required for the synthesis and secretion of crystalline cellulose microfibrils. A few other genes have been shown to be involved in this process, but their precise role is unclear. We report here the use of Tn5 transposon insertion mutagenesis to identify and characterize six non-cellulose-producing (Cel−) mutants of Gluconacetobacter hansenii ATCC 23769. The genes disrupted were acsA, acsC, ccpAx (encoding cellulose-complementing protein [the subscript “Ax” indicates genes from organisms formerly classified as Acetobacter xylinum]), dgc1 (encoding guanylate dicyclase), and crp-fnr (encoding a cyclic AMP receptor protein/fumarate nitrate reductase transcriptional regulator). Protein blot analysis revealed that (i) AcsB and AcsC were absent in the acsA mutant, (ii) the levels of AcsB and AcsC were significantly reduced in the ccpAx mutant, and (iii) the level of AcsD was not affected in any of the Cel− mutants. Promoter analysis showed that the acs operon does not include acsD, unlike the organization of the acs operon of several strains of closely related Gluconacetobacter xylinus. Complementation experiments confirmed that the gene disrupted in each Cel− mutant was responsible for the phenotype. Quantitative real-time PCR and protein blotting results suggest that the transcription of bglAx (encoding β-glucosidase and located immediately downstream from acsD) was strongly dependent on Crp/Fnr. A bglAx knockout mutant, generated via homologous recombination, produced only ∼16% of the wild-type cellulose level. Since the crp-fnr mutant did not produce any cellulose, Crp/Fnr may regulate the expression of other gene(s) involved in cellulose biosynthesis. PMID:24013627

Synthesis and characterization of amorphous cellulose from triacetate of cellulose

International Nuclear Information System (INIS)

Vega-Baudrit, Jose; Sibaja, Maria; Nikolaeva, Svetlana; Rivera A, Andrea

2014-01-01

It was carried-out a study for the synthesis and characterization of amorphous cellulose starting from cellulose triacetate. X-rays diffraction was used in order to obtain the cellulose crystallinity degree, also infrared spectroscopy FTIR was used. (author)

Class II recombinant phosphoribosyl diphosphate synthase from spinach

DEFF Research Database (Denmark)

Krath, B N; Hove-Jensen, B

2001-01-01

to other PRPP synthases the activity of spinach PRPP synthase isozyme 3 is independent of P(i), and the enzyme is inhibited by ribonucleoside diphosphates in a purely competitive manner, which indicates a lack of allosteric inhibition by these compounds. In addition spinach PRPP synthase isozyme 3 shows...... an unusual low specificity toward diphosphoryl donors by accepting dATP, GTP, CTP, and UTP in addition to ATP. The kinetic mechanism of the enzyme is an ordered steady state Bi Bi mechanism with K(ATP) and K(Rib-5-P) values of 170 and 110 micrometer, respectively, and a V(max) value of 13.1 micromol (min x...... mg of protein)(-1). The enzyme has an absolute requirement for magnesium ions, and maximal activity is obtained at 40 degrees C at pH 7.6....

Oxidoreductive Cellulose Depolymerization by the Enzymes Cellobiose Dehydrogenase and Glycoside Hydrolase 61▿†

Science.gov (United States)

Langston, James A.; Shaghasi, Tarana; Abbate, Eric; Xu, Feng; Vlasenko, Elena; Sweeney, Matt D.

2011-01-01

Several members of the glycoside hydrolase 61 (GH61) family of proteins have recently been shown to dramatically increase the breakdown of lignocellulosic biomass by microbial hydrolytic cellulases. However, purified GH61 proteins have neither demonstrable direct hydrolase activity on various polysaccharide or lignacious components of biomass nor an apparent hydrolase active site. Cellobiose dehydrogenase (CDH) is a secreted flavocytochrome produced by many cellulose-degrading fungi with no well-understood biological function. Here we demonstrate that the binary combination of Thermoascus aurantiacus GH61A (TaGH61A) and Humicola insolens CDH (HiCDH) cleaves cellulose into soluble, oxidized oligosaccharides. TaGH61A-HiCDH activity on cellulose is shown to be nonredundant with the activities of canonical endocellulase and exocellulase enzymes in microcrystalline cellulose cleavage, and while the combination of TaGH61A and HiCDH cleaves highly crystalline bacterial cellulose, it does not cleave soluble cellodextrins. GH61 and CDH proteins are coexpressed and secreted by the thermophilic ascomycete Thielavia terrestris in response to environmental cellulose, and the combined activities of T. terrestris GH61 and T. terrestris CDH are shown to synergize with T. terrestris cellulose hydrolases in the breakdown of cellulose. The action of GH61 and CDH on cellulose may constitute an important, but overlooked, biological oxidoreductive system that functions in microbial lignocellulose degradation and has applications in industrial biomass utilization. PMID:21821740

PsB multiprotein complex of Dictyostelium discoideum. Demonstration of cellulose binding activity and order of protein subunit assembly.

Science.gov (United States)

McGuire, V; Alexander, S

1996-06-14

The differentiated spores of Dictyostelium are surrounded by an extracellular matrix, the spore coat, which protects them from environmental factors allowing them to remain viable for extended periods of time. This presumably is a major evolutionary advantage. This unique extracellular matrix is composed of cellulose and glycoproteins. Previous work has shown that some of these spore coat glycoproteins exist as a preassembled multiprotein complex (the PsB multiprotein complex) which is stored in the prespore vesicles (Watson, N., McGuire, V., and Alexander, S (1994) J. Cell Sci. 107, 2567-2579). Later in development, the complex is synchronously secreted from the prespore vesicles and incorporated into the spore coat. We now have shown that the PsB complex has a specific in vitro cellulose binding activity. The analysis of mutants lacking individual subunits of the PsB complex revealed the relative order of assembly of the subunit proteins and demonstrated that the protein subunits must be assembled for cellulose binding activity. These results provide a biochemical explanation for the localization of this multiprotein complex in the spore coat.

An active site–tail interaction in the structure of hexahistidine-tagged Thermoplasma acidophilum citrate synthase

Energy Technology Data Exchange (ETDEWEB)

Murphy, Jesse R.; Donini, Stefano; Kappock, T. Joseph, E-mail: kappock@purdue.edu [Purdue University, 175 South University Street, West Lafayette, IN 47907-2063 (United States)

2015-09-23

Citrate synthase from the thermophilic euryarchaeon T. acidophilum fused to a hexahistidine tag was purified and biochemically characterized. The structure of the unliganded enzyme at 2.2 Å resolution contains tail–active site contacts in half of the active sites. Citrate synthase (CS) plays a central metabolic role in aerobes and many other organisms. The CS reaction comprises two half-reactions: a Claisen aldol condensation of acetyl-CoA (AcCoA) and oxaloacetate (OAA) that forms citryl-CoA (CitCoA), and CitCoA hydrolysis. Protein conformational changes that ‘close’ the active site play an important role in the assembly of a catalytically competent condensation active site. CS from the thermoacidophile Thermoplasma acidophilum (TpCS) possesses an endogenous Trp fluorophore that can be used to monitor the condensation reaction. The 2.2 Å resolution crystal structure of TpCS fused to a C-terminal hexahistidine tag (TpCSH6) reported here is an ‘open’ structure that, when compared with several liganded TpCS structures, helps to define a complete path for active-site closure. One active site in each dimer binds a neighboring His tag, the first nonsubstrate ligand known to occupy both the AcCoA and OAA binding sites. Solution data collectively suggest that this fortuitous interaction is stabilized by the crystalline lattice. As a polar but almost neutral ligand, the active site–tail interaction provides a new starting point for the design of bisubstrate-analog inhibitors of CS.

An active site–tail interaction in the structure of hexahistidine-tagged Thermoplasma acidophilum citrate synthase

International Nuclear Information System (INIS)

Murphy, Jesse R.; Donini, Stefano; Kappock, T. Joseph

2015-01-01

Citrate synthase from the thermophilic euryarchaeon T. acidophilum fused to a hexahistidine tag was purified and biochemically characterized. The structure of the unliganded enzyme at 2.2 Å resolution contains tail–active site contacts in half of the active sites. Citrate synthase (CS) plays a central metabolic role in aerobes and many other organisms. The CS reaction comprises two half-reactions: a Claisen aldol condensation of acetyl-CoA (AcCoA) and oxaloacetate (OAA) that forms citryl-CoA (CitCoA), and CitCoA hydrolysis. Protein conformational changes that ‘close’ the active site play an important role in the assembly of a catalytically competent condensation active site. CS from the thermoacidophile Thermoplasma acidophilum (TpCS) possesses an endogenous Trp fluorophore that can be used to monitor the condensation reaction. The 2.2 Å resolution crystal structure of TpCS fused to a C-terminal hexahistidine tag (TpCSH6) reported here is an ‘open’ structure that, when compared with several liganded TpCS structures, helps to define a complete path for active-site closure. One active site in each dimer binds a neighboring His tag, the first nonsubstrate ligand known to occupy both the AcCoA and OAA binding sites. Solution data collectively suggest that this fortuitous interaction is stabilized by the crystalline lattice. As a polar but almost neutral ligand, the active site–tail interaction provides a new starting point for the design of bisubstrate-analog inhibitors of CS

Approaching zero cellulose loss in cellulose nanocrystal (CNC) production: recovery and characterization of cellulosic solid residues (CSR) and CNC

Science.gov (United States)

Q.Q. Wang; J.Y. Zhu; R.S. Reiner; S.P. Verrill; U. Baxa; S.E. McNeil

2012-01-01

This study demonstrated the potential of simultaneously recovering cellulosic solid residues (CSR) and producing cellulose nanocrystals (CNCs) by strong sulfuric acid hydrolysis to minimize cellulose loss to near zero. A set of slightly milder acid hydrolysis conditions than that considered as “optimal” were used to significantly minimize the degradation of cellulose...

Characterization of two geraniol synthases from Valeriana officinalis and Lippia dulcis: similar activity but difference in subcellular localization

NARCIS (Netherlands)

Dong, L.; Miettinen, K.; Verstappen, F.W.A.; Voster, A.; Jongsma, M.A.; Memelink, J.; Krol, van der S.; Bouwmeester, H.J.

2013-01-01

Two geraniol synthases (GES), from Valeriana officinalis (VoGES) and Lippia dulcis (LdGES), were isolated and were shown to have geraniol biosynthetic activity with Km values of 32 µM and 51 µM for GPP, respectively, upon expression in Escherichia coli. The in planta enzymatic activity and

Sucrose Phosphate Synthase and Sucrose Accumulation at Low Temperature 1

Science.gov (United States)

Guy, Charles L.; Huber, Joan L. A.; Huber, Steven C.

1992-01-01

The influence of growth temperature on the free sugar and sucrose phosphate synthase content and activity of spinach (Spinacia oleracea) leaf tissue was studied. When plants were grown at 25°C for 3 weeks and then transferred to a constant 5°C, sucrose, glucose, and fructose accumulated to high levels during a 14-d period. Predawn sugar levels increased from 14- to 20-fold over the levels present at the outset of the low-temperature treatment. Sucrose was the most abundant free sugar before, during, and after exposure to 5°C. Leaf sucrose phosphate synthase activity was significantly increased by the low-temperature treatment, whereas sucrose synthase and invertases were not. Synthesis of the sucrose phosphate synthase subunit was increased during and after low-temperature exposure and paralleled an increase in the steady-state level of the subunit. The increases in sucrose and its primary biosynthetic enzyme, sucrose phosphate synthase, are discussed in relation to adjustment of metabolism to low nonfreezing temperature and freezing stress tolerance. Images Figure 1 Figure 2 Figure 3 PMID:16652990

Arabidopsis CDS blastp result: AK242585 [KOME

Lifescience Database Archive (English)

Full Text Available AK242585 J090010M20 At3g03050.1 68416.m00301 cellulose synthase family protein (CslD3) similar to cellulose... synthase catalytic subunit gi:2827143 from [Arabidopsis thaliana], cellulose syntha

Arabidopsis CDS blastp result: AK242601 [KOME

Lifescience Database Archive (English)

Full Text Available AK242601 J090014G03 At3g03050.1 68416.m00301 cellulose synthase family protein (CslD3) similar to cellulose... synthase catalytic subunit gi:2827143 from [Arabidopsis thaliana], cellulose syntha

Arabidopsis CDS blastp result: AK242890 [KOME

Lifescience Database Archive (English)

Full Text Available AK242890 J090079L19 At3g03050.1 68416.m00301 cellulose synthase family protein (CslD3) similar to cellulose... synthase catalytic subunit gi:2827143 from [Arabidopsis thaliana], cellulose syntha

Biofunctional paper via the covalent modification of cellulose.

Science.gov (United States)

Yu, Arthur; Shang, Jing; Cheng, Fang; Paik, Bradford A; Kaplan, Justin M; Andrade, Rodrigo B; Ratner, Daniel M

2012-07-31

Paper-based analytical devices are the subject of growing interest for the development of low-cost point-of-care diagnostics, environmental monitoring technologies, and research tools for limited-resource settings. However, there are limited chemistries available for the conjugation of biomolecules to cellulose for use in biomedical applications. Herein, divinyl sulfone (DVS) chemistry was demonstrated to immobilize small molecules, proteins, and DNA covalently onto the hydroxyl groups of cellulose membranes through nucleophilic addition. Assays on modified cellulose using protein-carbohydrate and protein-glycoprotein interactions as well as oligonucleotide hybridization showed that the membrane's bioactivity was specific, dose-dependent, and stable over a long period of time. The use of an inkjet printer to form patterns of biomolecules on DVS-activated cellulose illustrates the adaptability of the DVS functionalization technique to pattern sophisticated designs, with potential applications in cellulose-based lateral flow devices.

A Selective Assay to Detect Chitin and Biologically Active Nano-Machineries for Chitin-Biosynthesis with Their Intrinsic Chitin-Synthase Molecules

Directory of Open Access Journals (Sweden)

Hildgund Schrempf

2010-09-01

Full Text Available A new assay system for chitin has been developed. It comprises the chitin-binding protein ChbB in fusion with a His-tag as well as with a Strep-tag, the latter of which was chemically coupled to horseradish peroxidase. With the resulting complex, minimal quantities of chitin are photometrically detectable. In addition, the assay allows rapid scoring of the activity of chitin-synthases. As a result, a refined procedure for the rapid purification of yeast chitosomes (nano-machineries for chitin biosynthesis has been established. Immuno-electronmicroscopical studies of purified chitosomes, gained from a yeast strain carrying a chitin-synthase gene fused to that for GFP (green-fluorescence protein, has led to the in situ localization of chitin-synthase-GFP molecules within chitosomes.

Final Report for Award DE-FG02-09ER16008

Energy Technology Data Exchange (ETDEWEB)

Somerville, Chris

2014-04-26

The research objectives of this project was to characterize the factors that regulate the pattern, amount and quality of cellulose deposition in higher plants. We pursued this goal in four ways: (1) by searching for proteins that interact with the cellulose synthase complex using novel bioinformatics tools to identify genes which exhibit gene expression patterns that are highly correlated with cellulose synthase components, (2) by using cellulose synthase domains as bait in 2-hybrid screens, and then characterizing any proteins that are identified by both gene expression network analysis and 2-hybrid screens (3) by testing the function of all known post-translational modifications, (4) by identifying and characterizing kinases that carry out most of the known post-translational modification of cellulose synthase components.

Non-bilayer structures in mitochondrial membranes regulate ATP synthase activity.

Science.gov (United States)

Gasanov, Sardar E; Kim, Aleksandr A; Yaguzhinsky, Lev S; Dagda, Ruben K

2018-02-01

Cardiolipin (CL) is an anionic phospholipid at the inner mitochondrial membrane (IMM) that facilitates the formation of transient non-bilayer (non-lamellar) structures to maintain mitochondrial integrity. CL modulates mitochondrial functions including ATP synthesis. However, the biophysical mechanisms by which CL generates non-lamellar structures and the extent to which these structures contribute to ATP synthesis remain unknown. We hypothesized that CL and ATP synthase facilitate the formation of non-bilayer structures at the IMM to stimulate ATP synthesis. By using 1 H NMR and 31 P NMR techniques, we observed that increasing the temperature (8°C to 37°C), lowering the pH (3.0), or incubating intact mitochondria with CTII - an IMM-targeted toxin that increases the formation of immobilized non-bilayer structures - elevated the formation of non-bilayer structures to stimulate ATP synthesis. The F 0 sector of the ATP synthase complex can facilitate the formation of non-bilayer structures as incubating model membranes enriched with IMM-specific phospholipids with exogenous DCCD-binding protein of the F 0 sector (DCCD-BPF) elevated the formation of immobilized non-bilayer structures to a similar manner as CTII. Native PAGE assays revealed that CL, but not other anionic phospholipids, specifically binds to DCCD-BPF to promote the formation of stable lipid-protein complexes. Mechanistically, molecular docking studies identified two lipid binding sites for CL in DCCD-BPF. We propose a new model of ATP synthase regulation in which CL mediates the formation of non-bilayer structures that serve to cluster protons and ATP synthase complexes as a mechanism to enhance proton translocation to the F 0 sector, and thereby increase ATP synthesis. Copyright © 2017 Elsevier B.V. All rights reserved.

The relationship between skeletal muscle mitochondrial citrate synthase activity and whole body oxygen uptake adaptations in response to exercise training

DEFF Research Database (Denmark)

Vigelsø, Andreas; Andersen, Nynne B; Dela, Flemming

2014-01-01

Citrate synthase (CS) activity is a validated biomarker for mitochondrial density in skeletal muscle. CS activity is also used as a biochemical marker of the skeletal muscle oxidative adaptation to a training intervention, and a relationship between changes in whole body aerobic capacity and chan......Citrate synthase (CS) activity is a validated biomarker for mitochondrial density in skeletal muscle. CS activity is also used as a biochemical marker of the skeletal muscle oxidative adaptation to a training intervention, and a relationship between changes in whole body aerobic capacity...... and changes in CS activity is often assumed. However, this relationship and absolute values of CS and maximal oxygen uptake (V.O2max) has never been assessed across different studies. A systematic PubMed search on literature published from 1983 to 2013 was performed. The search profile included: citrate...... and CS activity. 70 publications with 97 intervention groups were included. There was a positive (r = 0.45) correlation (P

Studies on the Active Site of Deacetoxycephalosporin C Synthase

NARCIS (Netherlands)

Lloyd, Matthew D.; Lee, Hwei-Jen; Harlos, Karl; Zhang, Zhi-Hong; Baldwin, Jack E.; Schofield, Christopher J.; Charnock, John M.; Garner, C. David; Hara, Takane; Terwisscha van Scheltinga, Anke C.; Valegård, Karin; Viklund, Jenny A.C.; Hajdu, Janos; Andersson, Inger; Danielsson, Åke; Bhikhabhai, Rama

1999-01-01

The Fe(II) and 2-oxoglutarate-dependent dioxygenase deacetoxycephalosporin C synthase (DAOCS) from Streptomyces clavuligerus was expressed at ca 25% of total soluble protein in Escherichia coli and purified by an efficient large-scale procedure. Purified protein catalysed the conversions of

Structure of the human beta-ketoacyl [ACP] synthase from the mitochondrial type II fatty acid synthase

DEFF Research Database (Denmark)

Christensen, Caspar Elo; Kragelund, Birthe B; von Wettstein-Knowles, Penny

2007-01-01

Two distinct ways of organizing fatty acid biosynthesis exist: the multifunctional type I fatty acid synthase (FAS) of mammals, fungi, and lower eukaryotes with activities residing on one or two polypeptides; and the dissociated type II FAS of prokaryotes, plastids, and mitochondria with individual...... activities encoded by discrete genes. The beta-ketoacyl [ACP] synthase (KAS) moiety of the mitochondrial FAS (mtKAS) is targeted by the antibiotic cerulenin and possibly by the other antibiotics inhibiting prokaryotic KASes: thiolactomycin, platensimycin, and the alpha-methylene butyrolactone, C75. The high...... degree of structural similarity between mitochondrial and prokaryotic KASes complicates development of novel antibiotics targeting prokaryotic KAS without affecting KAS domains of cytoplasmic FAS. KASes catalyze the C(2) fatty acid elongation reaction using either a Cys-His-His or Cys-His-Asn catalytic...

Zinc affects differently growth, photosynthesis, antioxidant enzyme activities and phytochelatin synthase expression of four marine diatoms.

Science.gov (United States)

Nguyen-Deroche, Thi Le Nhung; Caruso, Aurore; Le, Thi Trung; Bui, Trang Viet; Schoefs, Benoît; Tremblin, Gérard; Morant-Manceau, Annick

2012-01-01

Zinc-supplementation (20 μM) effects on growth, photosynthesis, antioxidant enzyme activities (superoxide dismutase, ascorbate peroxidase, catalase), and the expression of phytochelatin synthase gene were investigated in four marine diatoms (Amphora acutiuscula, Nitzschia palea, Amphora coffeaeformis and Entomoneis paludosa). Zn-supplementation reduced the maximum cell density. A linear relationship was found between the evolution of gross photosynthesis and total chlorophyll content. The Zn treatment decreased the electron transport rate except in A. coffeaeformis and in E. paludosa at high irradiance. A linear relationship was found between the efficiency of light to evolve oxygen and the size of the light-harvesting antenna. The external carbonic anhydrase activity was stimulated in Zn-supplemented E. paludosa but was not correlated with an increase of photosynthesis. The total activity of the antioxidant enzymes did not display any clear increase except in ascorbate peroxidase activity in N. palea. The phytochelatin synthase gene was identified in the four diatoms, but its expression was only revealed in N. palea, without a clear difference between control and Zn-supplemented cells. Among the four species, A. paludosa was the most sensitive and A. coffeaeformis, the most tolerant. A. acutiuscula seemed to be under metal starvation, whereas, to survive, only N. palea developed several stress responses.

Zinc Affects Differently Growth, Photosynthesis, Antioxidant Enzyme Activities and Phytochelatin Synthase Expression of Four Marine Diatoms

Directory of Open Access Journals (Sweden)

Thi Le Nhung Nguyen-Deroche

2012-01-01

Full Text Available Zinc-supplementation (20 μM effects on growth, photosynthesis, antioxidant enzyme activities (superoxide dismutase, ascorbate peroxidase, catalase, and the expression of phytochelatin synthase gene were investigated in four marine diatoms (Amphora acutiuscula, Nitzschia palea, Amphora coffeaeformis and Entomoneis paludosa. Zn-supplementation reduced the maximum cell density. A linear relationship was found between the evolution of gross photosynthesis and total chlorophyll content. The Zn treatment decreased the electron transport rate except in A. coffeaeformis and in E. paludosa at high irradiance. A linear relationship was found between the efficiency of light to evolve oxygen and the size of the light-harvesting antenna. The external carbonic anhydrase activity was stimulated in Zn-supplemented E. paludosa but was not correlated with an increase of photosynthesis. The total activity of the antioxidant enzymes did not display any clear increase except in ascorbate peroxidase activity in N. palea. The phytochelatin synthase gene was identified in the four diatoms, but its expression was only revealed in N. palea, without a clear difference between control and Zn-supplemented cells. Among the four species, A. paludosa was the most sensitive and A. coffeaeformis, the most tolerant. A. acutiuscula seemed to be under metal starvation, whereas, to survive, only N. palea developed several stress responses.

Monoterpene synthases from common sage (Salvia officinalis)

Energy Technology Data Exchange (ETDEWEB)

Croteau, Rodney Bruce (Pullman, WA); Wise, Mitchell Lynn (Pullman, WA); Katahira, Eva Joy (Pullman, WA); Savage, Thomas Jonathan (Christchurch 5, NZ)

1999-01-01

cDNAs encoding (+)-bornyl diphosphate synthase, 1,8-cineole synthase and (+)-sabinene synthase from common sage (Salvia officinalis) have been isolated and sequenced, and the corresponding amino acid sequences has been determined. Accordingly, isolated DNA sequences (SEQ ID No:1; SEQ ID No:3 and SEQ ID No:5) are provided which code for the expression of (+)-bornyl diphosphate synthase (SEQ ID No:2), 1,8-cineole synthase (SEQ ID No:4) and (+)-sabinene synthase SEQ ID No:6), respectively, from sage (Salvia officinalis). In other aspects, replicable recombinant cloning vehicles are provided which code for (+)-bornyl diphosphate synthase, 1,8-cineole synthase or (+)-sabinene synthase, or for a base sequence sufficiently complementary to at least a portion of (+)-bornyl diphosphate synthase, 1,8-cineole synthase or (+)-sabinene synthase DNA or RNA to enable hybridization therewith. In yet other aspects, modified host cells are provided that have been transformed, transfected, infected and/or injected with a recombinant cloning vehicle and/or DNA sequence encoding (+)-bornyl diphosphate synthase, 1,8-cineole synthase or (+)-sabinene synthase. Thus, systems and methods are provided for the recombinant expression of the aforementioned recombinant monoterpene synthases that may be used to facilitate their production, isolation and purification in significant amounts. Recombinant (+)-bornyl diphosphate synthase, 1,8-cineole synthase and (+)-sabinene synthase may be used to obtain expression or enhanced expression of (+)-bornyl diphosphate synthase, 1,8-cineole synthase and (+)-sabinene synthase in plants in order to enhance the production of monoterpenoids, or may be otherwise employed for the regulation or expression of (+)-bornyl diphosphate synthase, 1,8-cineole synthase and (+)-sabinene synthase, or the production of their products.

Inhibition of muscle glycogen synthase activity and non-oxidative glucose disposal during hypoglycaemia in normal man

DEFF Research Database (Denmark)

Ørskov, Lotte; Bak, Jens Friis; Abildgaard, Ulrik

1996-01-01

The purpose of the present study was to evaluate the role of muscle glycogen synthase activity in the reduction of glucose uptake during hypoglycaemia. Six healthy young men were examined twice; during 120 min of hyperinsulinaemic (1.5 mU.kg-1. min-1) euglycaemia followed by: 1)240 min of graded ...

One-Pot Route towards Active TiO2 Doped Hierarchically Porous Cellulose: Highly Efficient Photocatalysts for Methylene Blue Degradation

Directory of Open Access Journals (Sweden)

Xiaoxia Sun

2017-03-01

Full Text Available In this study, novel photocatalyst monolith materials were successfully fabricated by a non-solvent induced phase separation (NIPS technique. By adding a certain amount of ethyl acetate (as non-solvent into a cellulose/LiCl/N,N-dimethylacetamide (DMAc solution, and successively adding titanium dioxide (TiO2 nanoparticles (NPs, cellulose/TiO2 composite monoliths with hierarchically porous structures were easily formed. The obtained composite monoliths possessed mesopores, and two kinds of macropores. Scanning Electron Microscope (SEM, Energy Dispersive Spectroscopy (EDS, Fourier Transform Infrared Spectroscopy (FT-IR, X-ray Diffraction (XRD, Brunauer-Emmett-Teller (BET, and Ultraviolet-visible Spectroscopy (UV-Vis measurements were adopted to characterize the cellulose/TiO2 composite monolith. The cellulose/TiO2 composite monoliths showed high efficiency of photocatalytic activity in the decomposition of methylene blue dye, which was decomposed up to 99% within 60 min under UV light. Moreover, the composite monoliths could retain 90% of the photodegradation efficiency after 10 cycles. The novel NIPS technique has great potential for fabricating recyclable photocatalysts with highly efficiency.

Physicotechnical, spectroscopic and thermogravimetric properties of powdered cellulose and microcrystalline cellulose derived from groundnut shells

Directory of Open Access Journals (Sweden)

Chukwuemeka P. Azubuike

2012-09-01

Full Text Available α-Cellulose and microcrystalline cellulose powders, derived from agricultural waste products, that have for the pharmaceutical industry, desirable physical (flow properties were investigated. α–Cellulose (GCN was extracted from groundnut shell (an agricultural waste product using a non-dissolving method based on inorganic reagents. Modification of this α -cellulose was carried out by partially hydrolysing it with 2N hydrochloric acid under reflux to obtain microcrystalline cellulose (MCGN. The physical, spectroscopic and thermal properties of the derived α-cellulose and microcrystalline cellulose powders were compared with Avicel® PH 101, a commercial brand of microcrystalline cellulose (MCCA, using standard methods. X-ray diffraction and infrared spectroscopy analysis showed that the α-cellulose had lower crystallinity. This suggested that treatment with 2N hydrochloric acid led to an increase in the crystallinity index. Thermogravimetric analysis showed quite similar thermal behavior for all cellulose samples, although the α-cellulose had a somewhat lower stability. A comparison of the physical properties between the microcrystalline celluloses and the α-cellulose suggests that microcrystalline cellulose (MCGN and MCCA might have better flow properties. In almost all cases, MCGN and MCCA had similar characteristics. Since groundnut shells are agricultural waste products, its utilization as a source of microcrystalline cellulose might be a good low-cost alternative to the more expensive commercial brand.

Investigation of the physico-mechanical properties of electrospun PVDF/cellulose nanofibers.

OpenAIRE

Issa, A.A.; Al-Maadeed, M.; Luyt, A.S.; Mrlik, M.; Hassan, M.K.

2016-01-01

The electro-activity and mechanical properties of PVDF depends mainly on the b-phase content and degree of crystallinity. In this study, cellulose fibers were used to improve these characteristics. This could be achieved because the hydroxyl groups on cellulose would force the fluorine atoms in PVDF to be in the trans-conformation, and the cellulose particles could act as nucleation centers. Electrospinning was used to prepare the PVDF/cellulose (nano)fibrous films, and this improved the tota...

Ionic Liquids and Cellulose: Dissolution, Chemical Modification and Preparation of New Cellulosic Materials

Science.gov (United States)

Isik, Mehmet; Sardon, Haritz; Mecerreyes, David

2014-01-01

Due to its abundance and a wide range of beneficial physical and chemical properties, cellulose has become very popular in order to produce materials for various applications. This review summarizes the recent advances in the development of new cellulose materials and technologies using ionic liquids. Dissolution of cellulose in ionic liquids has been used to develop new processing technologies, cellulose functionalization methods and new cellulose materials including blends, composites, fibers and ion gels. PMID:25000264

Biological evaluation of nanosilver incorporated cellulose pulp for hygiene products

Energy Technology Data Exchange (ETDEWEB)

Kavitha Sankar, P.C.; Ramakrishnan, Reshmi; Rosemary, M.J., E-mail: rosemarymj@lifecarehll.com

2016-04-01

Cellulose pulp has a visible market share in personal hygiene products such as sanitary napkins and baby diapers. However it offers good surface for growth of microorganisms. Huge amount of research is going on in developing hygiene products that do not initiate microbial growth. The objective of the present work is to produce antibacterial cellulose pulp by depositing silver nanopowder on the cellulose fiber. The silver nanoparticles used were of less than 100 nm in size and were characterised using transmission electron microscopy and X-ray powder diffraction studies. Antibacterial activity of the functionalized cellulose pulp was proved by JIS L 1902 method. The in-vitro cytotoxicity, in-vivo vaginal irritation and intracutaneous reactivity studies were done with silver nanopowder incorporated cellulose pulp for introducing a new value added product to the market. Cytotoxicity evaluation suggested that the silver nanoparticle incorporated cellulose pulp is non-cytotoxic. No irritation and skin sensitization were identified in animals tested with specific extracts prepared from the test material in the in-vivo experiments. The results indicated that the silver nanopowder incorporated cellulose pulp meets the requirements of the standard practices recommended for evaluating the biological reactivity and has good biocompatibility, hence can be classified as a safe hygiene product. - Highlights: • Different amounts of silver nanoparticles (0.2 g–0.4 g/napkin) were added to cellulose pulp. • The silver nanoparticle incorporated cellulose pulp was proved to be antibacterial by JIS L 1902 method. • The minimum concentration of silver required for antibacterial activity with no cytotoxicity has been found out. • In-vivo vaginal irritation and intracutaneous reactivity studies confirmed the biocompatibility of the material.

Biological evaluation of nanosilver incorporated cellulose pulp for hygiene products

International Nuclear Information System (INIS)

Kavitha Sankar, P.C.; Ramakrishnan, Reshmi; Rosemary, M.J.

2016-01-01

Cellulose pulp has a visible market share in personal hygiene products such as sanitary napkins and baby diapers. However it offers good surface for growth of microorganisms. Huge amount of research is going on in developing hygiene products that do not initiate microbial growth. The objective of the present work is to produce antibacterial cellulose pulp by depositing silver nanopowder on the cellulose fiber. The silver nanoparticles used were of less than 100 nm in size and were characterised using transmission electron microscopy and X-ray powder diffraction studies. Antibacterial activity of the functionalized cellulose pulp was proved by JIS L 1902 method. The in-vitro cytotoxicity, in-vivo vaginal irritation and intracutaneous reactivity studies were done with silver nanopowder incorporated cellulose pulp for introducing a new value added product to the market. Cytotoxicity evaluation suggested that the silver nanoparticle incorporated cellulose pulp is non-cytotoxic. No irritation and skin sensitization were identified in animals tested with specific extracts prepared from the test material in the in-vivo experiments. The results indicated that the silver nanopowder incorporated cellulose pulp meets the requirements of the standard practices recommended for evaluating the biological reactivity and has good biocompatibility, hence can be classified as a safe hygiene product. - Highlights: • Different amounts of silver nanoparticles (0.2 g–0.4 g/napkin) were added to cellulose pulp. • The silver nanoparticle incorporated cellulose pulp was proved to be antibacterial by JIS L 1902 method. • The minimum concentration of silver required for antibacterial activity with no cytotoxicity has been found out. • In-vivo vaginal irritation and intracutaneous reactivity studies confirmed the biocompatibility of the material.

Purification and characterization of CDP-diacylglycerol synthase from Saccharomyces cerevisiae

International Nuclear Information System (INIS)

Kelley, M.J.; Carman, G.M.

1987-01-01

The membrane-associated phospholipid biosynthetic enzyme CDP-diacylglycerol synthase (CTP:phosphatidate cytidylyltransferase was purified 2300-fold from Saccharomyces cerevisiae. The purification procedure included Triton X-100 solubilization of mitochondrial membranes, CDP-diacylglycerol-Sepharose affinity chromatography, and hydroxylapatite chromatography. The procedure resulted in a nearly homogeneous enzyme preparation as determined by native and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Radiation inactivation of mitochondrial associated and purified CDP-diacylglycerol synthase suggested that the molecular weight of the native enzyme was 114,000. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the purified enzyme preparation yielded two subunits with molecular weights of 56,000 and 54,000. Antibodies prepared against the purified enzyme immunoprecipitated CDP-diacylglycerol synthase activity and subunits. CDP-diacylglycerol synthase activity was dependent on magnesium ions and Triton X-100 at pH 6.5. Thio-reactive agents inhibited activity. The activation energy for the reaction was 9 kcal/mol, and the enzyme was thermally labile above 30 degrees C. The Km values for CTP and phosphatidate were 1 and 0.5 mM, respectively, and the Vmax was 4700 nmol/min/mg. Results of kinetic and isotopic exchange reactions suggested that the enzyme catalyzes a sequential Bi Bi reaction mechanism

Electrically conductive cellulose composite

Science.gov (United States)

Evans, Barbara R.; O'Neill, Hugh M.; Woodward, Jonathan

2010-05-04

An electrically conductive cellulose composite includes a cellulose matrix and an electrically conductive carbonaceous material incorporated into the cellulose matrix. The electrical conductivity of the cellulose composite is at least 10 .mu.S/cm at 25.degree. C. The composite can be made by incorporating the electrically conductive carbonaceous material into a culture medium with a cellulose-producing organism, such as Gluconoacetobacter hansenii. The composites can be used to form electrodes, such as for use in membrane electrode assemblies for fuel cells.

Ionic Liquids and Cellulose: Dissolution, Chemical Modification and Preparation of New Cellulosic Materials

Directory of Open Access Journals (Sweden)

Mehmet Isik

2014-07-01

Full Text Available Due to its abundance and a wide range of beneficial physical and chemical properties, cellulose has become very popular in order to produce materials for various applications. This review summarizes the recent advances in the development of new cellulose materials and technologies using ionic liquids. Dissolution of cellulose in ionic liquids has been used to develop new processing technologies, cellulose functionalization methods and new cellulose materials including blends, composites, fibers and ion gels.

Thermostable cellulases, and mutants thereof, capable of hydrolyzing cellulose in ionic liquid

Science.gov (United States)

Sapra, Rajat; Datta, Supratim; Chen, Zhiwei; Holmes, Bradley M.; Simmons, Blake A.; Blanch, Harvey W.

2016-04-26

The present invention provides for a composition comprising an ionic liquid and a thermostable cellulose, and a method of hydrolyzing a cellulose, comprising: (a) providing a composition comprising a solution comprising an ionic liquid and a cellulose, and (b) introducing a thermostable cellulase to the solution, such that the cellulose is hydrolyzed by the cellulase. The present invention also provides for a Thermatoga maritima thermostable cellulase mutant with increased cellulase activity.

Genomics of aerobic cellulose utilization systems in actinobacteria.

Directory of Open Access Journals (Sweden)

Iain Anderson

Full Text Available Cellulose degrading enzymes have important functions in the biotechnology industry, including the production of biofuels from lignocellulosic biomass. Anaerobes including Clostridium species organize cellulases and other glycosyl hydrolases into large complexes known as cellulosomes. In contrast, aerobic actinobacteria utilize systems comprised of independently acting enzymes, often with carbohydrate binding domains. Numerous actinobacterial genomes have become available through the Genomic Encyclopedia of Bacteria and Archaea (GEBA project. We identified putative cellulose-degrading enzymes belonging to families GH5, GH6, GH8, GH9, GH12, GH48, and GH51 in the genomes of eleven members of the actinobacteria. The eleven organisms were tested in several assays for cellulose degradation, and eight of the organisms showed evidence of cellulase activity. The three with the highest cellulase activity were Actinosynnema mirum, Cellulomonas flavigena, and Xylanimonas cellulosilytica. Cellobiose is known to induce cellulolytic enzymes in the model organism Thermobifida fusca, but only Nocardiopsis dassonvillei showed higher cellulolytic activity in the presence of cellobiose. In T. fusca, cellulases and a putative cellobiose ABC transporter are regulated by the transcriptional regulator CelR. Nine organisms appear to use the CelR site or a closely related binding site to regulate an ABC transporter. In some, CelR also regulates cellulases, while cellulases are controlled by different regulatory sites in three organisms. Mining of genome data for cellulose degradative enzymes followed by experimental verification successfully identified several actinobacteria species which were not previously known to degrade cellulose as cellulolytic organisms.

Photo-Activated Localization Microscopy of Single Carbohydrate Binding Modules on Cellulose Nanofibers

Science.gov (United States)

Hor, Amy; Dagel, Daryl; Luu, Quocanh; Savaikar, Madhusudan; Ding, Shi-You; Smith, Steve

2015-03-01

Photo Activated Localization Microscopy (PALM) is used to conduct an in vivo study of the binding affinity of polysaccharide-specific Carbohydrate Binding Modules (CBMs) to insoluble cellulose substrates. Two families of CBMs, namely TrCBM1 and CtCBM3, were modified to incorporate photo-activatable mCherry fluorescent protein (PAmCherry), and exposed to highly crystalline Valonia cellulose nano-fibrils. The resulting PALM images show CBMs binding along the nano-fibril long axis in a punctuated linear array, localized with, on average, 10 nm precision. Statistical analysis of the binding events results in nearest neighbor distributions between CBMs. A comparison between TrCBM1 and CtCBM3 reveals a similarity in the nearest neighbor distribution peaks but differences in the overall binding density. The former is attributed to steric hindrance among the CBMs on the nano-fibril whereas the latter is attributed to differences in the CBMs' binding strength. These results are compared to similar distributions derived from TEM measurements of dried samples of CtCBM3-CdSs quantum dot bioconjugates and AFM images of CtCBM3-GFP bound to similar Valonia nano-fibrils. Funding provided by NSF MPS/DMR/BMAT Award # 1206908.

Adsorption of Saccharomyces cerevisiae onto cellulose and ecteola-cellulose films for ethanol production

Energy Technology Data Exchange (ETDEWEB)

Lueng, K.L.; Joshi, S.; Yamazaki, H.

1983-05-01

Epichlorohydrin-triethanolamine (ECTEOLA)-cellulose films (paper and cloth) have been found to bind Saccharomyces cerevisiae cells which were able to develop metabolically active colonies on the surface of the films. Umodified cellulose films also bound the yeast but to a lesser extent. Film fermenters were constructed by coiling a double layer of the cloth and copper screen and vertically placing the resulting cartridge into a column. These film fermenters were able to convert the sugars (14%) in the hydrolysate of a Jerusalem artichoke tuber into ethanol, with 90% of the theoretical yield after 6 hours of fermentation. The bound yeast produced ethanol at a specific rate of 1.0 g ethanol per g cell per hour. (Refs. 4).

Fabrication of polyaniline/carboxymethyl cellulose/cellulose nanofibrous mats and their biosensing application

International Nuclear Information System (INIS)

Fu, Jiapeng; Pang, Zengyuan; Yang, Jie; Huang, Fenglin; Cai, Yibing; Wei, Qufu

2015-01-01

Graphical abstract: - Highlights: • PANI nanorods have been grown onto the surface of CMC/cellulose nanofibers for the fabrication of biosensor substrate material. • The proposed laccase biosensor exhibited a low detection limit and high sensitivity in the detection of catechol. • Hierarchical PANI/CMC/cellulose nanofibers are the promising material in the design of high-efficient biosensors. - Abstract: We report a facile approach to synthesizing and immobilizing polyaniline nanorods onto carboxymethyl cellulose (CMC)-modified cellulose nanofibers for their biosensing application. Firstly, the hierarchical PANI/CMC/cellulose nanofibers were fabricated by in situ polymerization of aniline on the CMC-modified cellulose nanofiber. Subsequently, the PANI/CMC/cellulose nanofibrous mat modified with laccase (Lac) was used as biosensor substrate material for the detection of catechol. PANI/CMC/cellulose nanofibers with highly conductive and three dimensional nanostructure were characterized by scanning electron microscopy (SEM), transmission electron microscope (TEM), Fourier transform infrared spectra (FT-IR), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Under optimum conditions, the Lac/PANI/CMC/cellulose/glassy carbon electrode (GCE) exhibited a fast response time (within 8 s), a linear response range from 0.497 μM to 2.27 mM with a high sensitivity and low detection limit of 0.374 μM (3σ). The developed biosensor also displayed good repeatability, reproducibility as well as selectivity. The results indicated that the composite mat has potential application in enzyme biosensors

Fabrication of polyaniline/carboxymethyl cellulose/cellulose nanofibrous mats and their biosensing application

Energy Technology Data Exchange (ETDEWEB)

Fu, Jiapeng, E-mail: firgexiao@sina.cn; Pang, Zengyuan, E-mail: pangzengyuan1212@163.com; Yang, Jie, E-mail: young1993@126.com; Huang, Fenglin, E-mail: flhuang@jiangnan.edu.cn; Cai, Yibing, E-mail: yibingcai@jiangnan.edu.cn; Wei, Qufu, E-mail: qfwei@jiangnan.edu.cn

2015-09-15

Graphical abstract: - Highlights: • PANI nanorods have been grown onto the surface of CMC/cellulose nanofibers for the fabrication of biosensor substrate material. • The proposed laccase biosensor exhibited a low detection limit and high sensitivity in the detection of catechol. • Hierarchical PANI/CMC/cellulose nanofibers are the promising material in the design of high-efficient biosensors. - Abstract: We report a facile approach to synthesizing and immobilizing polyaniline nanorods onto carboxymethyl cellulose (CMC)-modified cellulose nanofibers for their biosensing application. Firstly, the hierarchical PANI/CMC/cellulose nanofibers were fabricated by in situ polymerization of aniline on the CMC-modified cellulose nanofiber. Subsequently, the PANI/CMC/cellulose nanofibrous mat modified with laccase (Lac) was used as biosensor substrate material for the detection of catechol. PANI/CMC/cellulose nanofibers with highly conductive and three dimensional nanostructure were characterized by scanning electron microscopy (SEM), transmission electron microscope (TEM), Fourier transform infrared spectra (FT-IR), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Under optimum conditions, the Lac/PANI/CMC/cellulose/glassy carbon electrode (GCE) exhibited a fast response time (within 8 s), a linear response range from 0.497 μM to 2.27 mM with a high sensitivity and low detection limit of 0.374 μM (3σ). The developed biosensor also displayed good repeatability, reproducibility as well as selectivity. The results indicated that the composite mat has potential application in enzyme biosensors.

High Dehumidification Performance of Amorphous Cellulose Composite Membranes prepared from Trimethylsilyl Cellulose

KAUST Repository

Puspasari, Tiara

2018-04-11

Cellulose is widely regarded as an environmentally friendly, natural and low cost material which can significantly contribute the sustainable economic growth. In this study, cellulose composite membranes were prepared via regeneration of trimethylsilyl cellulose (TMSC), an easily synthesized cellulose derivative. The amorphous hydrophilic feature of the regenerated cellulose enabled fast permeation of water vapour. The pore-free cellulose layer thickness was adjustable by the initial TMSC concentration and acted as an efficient gas barrier. As a result, a 5,000 GPU water vapour transmission rate (WVTR) at the highest ideal selectivity of 1.1 x 106 was achieved by the membranes spin coated from a 7% (w/w) TMSC solution. The membranes maintained a 4,000 GPU WVTR with selectivity of 1.1 x 104 in the mixed-gas experiments, surpassing the performances of the previously reported composite membranes. This study provides a simple way to not only produce high performance membranes but also to advance cellulose as a low-cost and sustainable membrane material for dehumidification applications.

Degradation of γ-irradiated cellulose by the accumulating culture of a cellulose bacterium

International Nuclear Information System (INIS)

Namsaraev, B.B.; Kuznetsova, E.A.; Termkhitarova, N.G.

1987-01-01

Possibility of degradation of γ-irradiated cellulose by the accumulating culture of an anaerobic cellulose bacterium has been investigated. Cellulose irradiation by γ-quanta (Co 60 ) has been carried out using the RKh-30 device with 35.9 Gy/min dose rate. Radiation monitoring has been carried out by the standard ferrosulfate method. Samples have been irradiated in dry state or when water presenting with MGy. It is detected that the accumulating culture with the growth on the irradiated cellulose has a lag-phase, which duration reduces when the cellulose cleaning by flushing with distillation water. The culture has higher growth and substrate consumption rate when growing by cellulose irradiated in comparison with non-irradiated one. The economical coefficient is the same in using both the irradiated and non-irradiated cellulose. The quantity of forming reducing saccharides, organic acids, methane and carbon dioxide is the same both when cultivating by irradiated cellulose and by non-irradiated. pH of the culture liquid is shifted to the acid nature in the process of growth

Nano-tubular cellulose for bioprocess technology development.

Science.gov (United States)

Koutinas, Athanasios A; Sypsas, Vasilios; Kandylis, Panagiotis; Michelis, Andreas; Bekatorou, Argyro; Kourkoutas, Yiannis; Kordulis, Christos; Lycourghiotis, Alexis; Banat, Ibrahim M; Nigam, Poonam; Marchant, Roger; Giannouli, Myrsini; Yianoulis, Panagiotis

2012-01-01

Delignified cellulosic material has shown a significant promotional effect on the alcoholic fermentation as yeast immobilization support. However, its potential for further biotechnological development is unexploited. This study reports the characterization of this tubular/porous cellulosic material, which was done by SEM, porosimetry and X-ray powder diffractometry. The results showed that the structure of nano-tubular cellulose (NC) justifies its suitability for use in "cold pasteurization" processes and its promoting activity in bioprocessing (fermentation). The last was explained by a glucose pump theory. Also, it was demonstrated that crystallization of viscous invert sugar solutions during freeze drying could not be otherwise achieved unless NC was present. This effect as well as the feasibility of extremely low temperature fermentation are due to reduction of the activation energy, and have facilitated the development of technologies such as wine fermentations at home scale (in a domestic refrigerator). Moreover, NC may lead to new perspectives in research such as the development of new composites, templates for cylindrical nano-particles, etc.

Co-inoculating ruminal content neither provides active hydrolytic microbes nor improves methanization of ¹³C-cellulose in batch digesters.

Science.gov (United States)

Chapleur, Olivier; Bize, Ariane; Serain, Thibaut; Mazéas, Laurent; Bouchez, Théodore

2014-03-01

Cellulose hydrolysis often limits the kinetics and efficiency of anaerobic degradation in industrial digesters. In animal digestive systems, specialized microorganisms enable cellulose biodegradation at significantly higher rates. This study aims to assess the potential of ruminal microbial communities to settle and to express their cellulolytic properties in anaerobic digesters. Cellulose-degrading batch incubations were co-inoculated with municipal solid waste digester sludge and ruminal content. ¹³C-labeled cellulose degradation was described over time with Gas Chromatography-Combustion-Isotope Ratio Mass Spectrometry. Results were linked to the identification of the microorganisms assimilating ¹³C and to the monitoring of their relative dynamics. Cellulose degradation in co-inoculated incubations was efficient but not significantly improved. Transient disturbances in degradation pathways occurred, as revealed by propionate accumulation. Automated Ribosomal Intergenic Spacer Analysis dynamics and pyrosequencing revealed that expected classes of Bacteria and Archaea were active and degraded cellulose. However, despite the favorable co-inoculation conditions, molecular tools also revealed that no ruminal species settled in the bioreactors. Other specific parameters were probably needed for this to happen. This study shows that exploiting the rumen's cellulolytic properties in anaerobic digesters is not straightforward. Co-inoculation can only be successful if ruminal microorganisms manage to thrive in the anaerobic digester and outcompete native microorganisms, which requires specific nutritional and environmental parameters, and a meticulous reproduction of the selection pressure encountered in the rumen. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

Leishmania donovani argininosuccinate synthase is an active enzyme associated with parasite pathogenesis.

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Ines Lakhal-Naouar

Full Text Available BACKGROUND: Gene expression analysis in Leishmania donovani (Ld identified an orthologue of the urea cycle enzyme, argininosuccinate synthase (LdASS, that was more abundantly expressed in amastigotes than in promastigotes. In order to characterize in detail this newly identified protein in Leishmania, we determined its enzymatic activity, subcellular localization in the parasite and affect on virulence in vivo. METHODOLOGY/PRINCIPAL FINDINGS: Two parasite cell lines either over expressing wild type LdASS or a mutant form (G128S associated with severe cases of citrullinemia in humans were developed. In addition we also produced bacterially expressed recombinant forms of the same proteins. Our results demonstrated that LdASS has argininosuccinate synthase enzymatic activity that is abolished using an ASS specific inhibitor (MDLA: methyl-D-L-Aspartic acid. However, the mutant form of the protein is inactive. We demonstrate that though LdASS has a glycosomal targeting signal that binds the targeting apparatus in vitro, only a small proportion of the total cellular ASS is localized in a vesicle, as indicated by protection from protease digestion of the crude organelle fraction. The majority of LdASS was found to be in the cytosolic fraction that may include large cytosolic complexes as indicated by the punctate distribution in IFA. Surprisingly, comparison to known glycosomal proteins by IFA revealed that LdASS was located in a structure different from the known glycosomal vesicles. Significantly, parasites expressing a mutant form of LdASS associated with a loss of in vitro activity had reduced virulence in vivo in BALB/c mice as demonstrated by a significant reduction in the parasite load in spleen and liver. CONCLUSION/SIGNIFICANCE: Our study suggests that LdASS is an active enzyme, with unique localization and essential for parasite survival and growth in the mammalian host. Based on these observations LdASS could be further explored as a

Electrical and mechanical characterization of nanoscale-layered cellulose-based electro-active paper.

Science.gov (United States)

Yun, Gyu-Young; Yun, Ki-Ju; Kim, Joo-Hyung; Kim, Jaehwan

2011-01-01

In order to understand the electro-mechanical behavior of piezoelectric electro active paper (EAPap), the converse and direct piezoelectric characterization of cellulose EAPap was studied and compared. A delay between the electrical field and the induced strain of EAPap was observed due to the inner nano-voids or the localized amorphous regions in layer-by-layered structure to capture or hold the electrical charges and remnant ions. The linear relation between electric field and induced strain is also observed. The electro-mechanical performance of EAPap is discussed in detail in this paper.

Liquid crystalline solutions of cellulose in phosphoric acid for preparing cellulose yarns

NARCIS (Netherlands)

Boerstoel, H.

2006-01-01

The presen thesis describes a new process for manufacturing high tenacity and high modulus cellulose yarns. A new direct solvent for cellulose has been discovered, leading to liquid crystalline solutions. This new solvent, superphosphoric acid, rapidly dissolves cellulose. These liquid crystalline

Functional genomic analysis supports conservation of function among cellulose synthase-like a gene family members and suggests diverse roles of mannans in plants

DEFF Research Database (Denmark)

Liepman, Aaron H; Nairn, C Joseph; Willats, William G T

2007-01-01

from Arabidopsis (Arabidopsis thaliana), guar (Cyamopsis tetragonolobus), and Populus trichocarpa catalyze beta-1,4-mannan and glucomannan synthase reactions in vitro. Mannan polysaccharides and homologs of CslA genes appear to be present in all lineages of land plants analyzed to date. In many plants......, the CslA genes are members of extended multigene families; however, it is not known whether all CslA proteins are glucomannan synthases. CslA proteins from diverse land plant species, including representatives of the mono- and dicotyledonous angiosperms, gymnosperms, and bryophytes, were produced...... they are prevalent at cell junctions and in buds. Taken together, these results demonstrate that members of the CslA gene family from diverse plant species encode glucomannan synthases and support the hypothesis that mannans function in metabolic networks devoted to other cellular processes in addition to cell wall...

Formation of cellulases and degradation of cellulose by several fungi

Energy Technology Data Exchange (ETDEWEB)

Herr, D; Luck, G; Dellweg, H

1978-01-01

Five strains of fungi (Aspergillus niger, Lenzites trabea, Myrothecium verrucaria, Trichoderma koningii and Trichoderma lignorum) were tested for the production of cellulolytic enzymes on pure glucose and on cellulose media. The most active strains belonging to the genera of Trichoderma, Aspergillus and Myrothecium, also secreting high activities of ..beta..-glucosidase, were grown in a bioreactor under defined conditions. Depending on the strain this procedure resulted in a manifold increase in cellulolytic activities. The culture filtrates were concentrated and standardized with respect to ..beta..-glucosidase activity and used for the hydrolysis of cellulose powder. With Trichoderma-cellulase, 46% conversion of crystalline cellulose to glucose was achieved within 48 h. The ratio of cellobiose to glucose found in the hydrolysate, the amount of high molecular carbohydrates as well as the degree of hydrolysis widely depended on the type of cellulase used.

Isolation and functional effects of monoclonal antibodies binding to thymidylate synthase.

Science.gov (United States)

Jastreboff, M M; Todd, M B; Malech, H L; Bertino, J R

1985-01-29

Monoclonal antibodies against electrophoretically pure thymidylate synthase from HeLa cells have been produced. Antibodies (M-TS-4 and M-TS-9) from hybridoma clones were shown by enzyme-linked immunoassay to recognize thymidylate synthase from a variety of human cell lines, but they did not bind to thymidylate synthase from mouse cell lines. The strongest binding of antibodies was observed to enzyme from HeLa cells. These two monoclonal antibodies bind simultaneously to different antigenic sites on thymidylate synthase purified from HeLa cells, as reflected by a high additivity index and results of cross-linked radioimmunoassay. Both monoclonal antibodies inhibit the activity of thymidylate synthase from human cell lines. The strongest inhibition was observed with thymidylate synthase from HeLa cells. Monoclonal antibody M-TS-9 (IgM subclass) decreased the rate of binding of [3H]FdUMP to thymidylate synthase in the presence of 5,10-methylenetetrahydrofolate while M-TS-4 (IgG1) did not change the rate of ternary complex formation. These data indicate that the antibodies recognize different epitopes on the enzyme molecule.

The preparation, characterization and actuation behavior of polyaniline and cellulose blended electro-active paper

International Nuclear Information System (INIS)

John, Amalraj; Mahadeva, Suresha K; Kim, Jaehwan

2010-01-01

This paper reports polyaniline and cellulose blended electro-active paper (EAPap) that can produce large bending displacement at ambient humidity conditions with long lifetime durability. A novel solution processable polyaniline-p-toluene sulfonate (PANI–PTSA) salt was prepared by an inverted emulsion polymerization technique using benzoyl peroxide and p-toluene sulfonic acid. Cellulose solution prepared by dissolving cotton with lithium chloride/N, N-dimethylacetamide was mixed with the PANI emaraldine salt solution and a cellulose–PANI blended film was obtained. The obtained cellulose–PANI film was characterized by ultraviolet–visible (UV–visible), x-ray diffraction, scanning electron microscopy and tensile test methods. A cellulose–PANI EAPap actuator was made by depositing very thin gold electrodes on both sides of the cellulose–PANI film. When the actuator performance of the cellulose–PANI EAPap was evaluated in terms of bending displacement with respect to the actuation frequencies, voltages and relative humidity levels, a large bending displacement was shown at ambient humidity conditions with long lifetime durability

Surface and Adsorption Properties of Activated Carbon Fabric Prepared from Cellulosic Polymer: Mixed Activation Method

Energy Technology Data Exchange (ETDEWEB)

Bhati, Surendra; Mahur, J. S.; Choubey, O. N. [Barkatullah Univ., Bhopal (India); Dixit, Mahur Savita [Maulana Azad National Institute of Technology, Bhopla (India)

2013-02-15

In this study, activated carbon fabric was prepared from a cellulose-based polymer (viscose rayon) via a combination of physical and chemical activation (mixed activation) processes by means of CO{sub 2} as a gasifying agent and surface and adsorption properties were evaluated. Experiments were performed to investigate the consequence of activation temperature (750, 800, 850 and 925 .deg. C), activation time (15, 30, 45 and 60 minutes) and CO{sub 2} flow rate (100, 200, 300 and 400 mL/min) on the surface and adsorption properties of ACF. The nitrogen adsorption isotherm at 77 K was measured and used for the determination of surface area, total pore volume, micropore volume, mesopore volume and pore size distribution using BET, t-plot, DR, BJH and DFT methods, respectively. It was observed that BET surface area and TPV increase with rising activation temperature and time due to the formation of new pores and the alteration of micropores into mesopores. It was also found that activation temperature dominantly affects the surface properties of ACF. The adsorption of iodine and CCl{sub 4} onto ACF was investigated and both were found to correlate with surface area.

Surface and Adsorption Properties of Activated Carbon Fabric Prepared from Cellulosic Polymer: Mixed Activation Method

International Nuclear Information System (INIS)

Bhati, Surendra; Mahur, J. S.; Choubey, O. N.; Dixit, Mahur Savita

2013-01-01

In this study, activated carbon fabric was prepared from a cellulose-based polymer (viscose rayon) via a combination of physical and chemical activation (mixed activation) processes by means of CO 2 as a gasifying agent and surface and adsorption properties were evaluated. Experiments were performed to investigate the consequence of activation temperature (750, 800, 850 and 925 .deg. C), activation time (15, 30, 45 and 60 minutes) and CO 2 flow rate (100, 200, 300 and 400 mL/min) on the surface and adsorption properties of ACF. The nitrogen adsorption isotherm at 77 K was measured and used for the determination of surface area, total pore volume, micropore volume, mesopore volume and pore size distribution using BET, t-plot, DR, BJH and DFT methods, respectively. It was observed that BET surface area and TPV increase with rising activation temperature and time due to the formation of new pores and the alteration of micropores into mesopores. It was also found that activation temperature dominantly affects the surface properties of ACF. The adsorption of iodine and CCl 4 onto ACF was investigated and both were found to correlate with surface area

Characterization of cellulose nanowhiskers

International Nuclear Information System (INIS)

Nascimento, Nayra R.; Pinheiro, Ivanei F.; Morales, Ana R.; Ravagnani, Sergio P.; Mei, Lucia

2015-01-01

Cellulose is the most abundant polymer earth. The cellulose nanowhiskers can be extracted from the cellulose. These have attracted attention for its use in nanostructured materials for various applications, such as nanocomposites, because they have peculiar characteristics, among them, high aspect ratio, biodegradability and excellent mechanical properties. This work aims to characterize cellulose nanowhiskers from microcrystalline cellulose. Therefore, these materials were characterized by X-ray diffraction (XRD) to assess the degree of crystallinity, infrared spectroscopy (FT-IR), transmission electron microscopy (TEM) to the morphology of nanowhiskers and thermal stability was evaluated by Thermogravimetric Analysis (TGA). (author)

New procedures to measure synthase and phosphatase activities of bis-phosphoglycerate mutase. Interest for development of therapeutic drugs

International Nuclear Information System (INIS)

Ravel, P.; Garel, M.C.; Toullec, D.

1997-01-01

In red blood cells, a modulation of the level of the allosteric effector of hemoglobin, 2,3-diphosphoglycerate (2,3-DPG) would have implications in the treatment of ischemia and sickle cell anemia. Its concentrations is determined by the relative activities of the synthase and phosphatase reactions of the multifunctional bis-phosphoglycerate mutase (BPGM). In this report we develop first a more direct synthase assay which uses glyceraldehyde phosphate to suppress the aldolase and triose phosphate isomerase reactions. Secondly we propose a radioactive phosphatase assay coupled to chromatographic separation and identification of the reaction products by paper electrophoresis. Such identification of these products allows us to show that the multifunctional BPGM expresses its mutase instead of its phosphatase activity in conditions of competition between the 3-phosphoglycerate and the 2-phospho-glycolate activator in the phosphatase reaction. These two more precise procedures could be used to study the effects of substrate and cofactor analogues regarding potential therapeutic approaches and could be used for clinical analyses to detect deficiency of BPGM. (author)

CELLULOSIC NANOCOMPOSITES: A REVIEW

Directory of Open Access Journals (Sweden)

Martin A. Hubbe

2008-08-01

Full Text Available Because of their wide abundance, their renewable and environmentally benign nature, and their outstanding mechanical properties, a great deal of attention has been paid recently to cellulosic nanofibrillar structures as components in nanocomposites. A first major challenge has been to find efficient ways to liberate cellulosic fibrils from different source materials, including wood, agricultural residues, or bacterial cellulose. A second major challenge has involved the lack of compatibility of cellulosic surfaces with a variety of plastic materials. The water-swellable nature of cellulose, especially in its non-crystalline regions, also can be a concern in various composite materials. This review of recent work shows that considerable progress has been achieved in addressing these issues and that there is potential to use cellulosic nano-components in a wide range of high-tech applications.

The identification of and relief from Fe3+ inhibition for both cellulose and cellulase in cellulose saccharification catalyzed by cellulases from Penicillium decumbens.

Science.gov (United States)

Wang, Mingyu; Mu, Ziming; Wang, Junli; Hou, Shaoli; Han, Lijuan; Dong, Yanmei; Xiao, Lin; Xia, Ruirui; Fang, Xu

2013-04-01

Lignocellulosic biomass is an underutilized, renewable resource that can be converted to biofuels. The key step in this conversion is cellulose saccharification catalyzed by cellulase. In this work, the effect of metal ions on cellulose hydrolysis by cellulases from Penicillium decumbens was reported for the first time. Fe(3+) and Cu(2+) were shown to be inhibitory. Further studies on Fe(3+) inhibition showed the inhibition takes place on both enzyme and substrate levels. Fe(3+) treatment damages cellulases' capability to degrade cellulose and inhibits all major cellulase activities. Fe(3+) treatment also reduces the digestibility of cellulose, due to its oxidation. Treatment of Fe(3+)-treated cellulose with DTT and supplementation of EDTA to saccharification systems partially relieved Fe(3+) inhibition. It was concluded that Fe(3+) inhibition in cellulose degradation is a complicated process in which multiple inhibition events occur, and that relief from Fe(3+) inhibition can be achieved by the supplementation of reducing or chelating agents. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effect of chemical modifications of cellulose on the activity of a cellulase from Aspergillus niger

Energy Technology Data Exchange (ETDEWEB)

Boyer, R.F.; Redmond, M.A.

1983-05-01

Five chemically modified forms of cellulose were prepared, characterized, and tested as substrates for a homogeneous glucanohydrolase from A. niger. The relative order of reactivity at pH 4.0 was DEAE = PEI more than benzyl DEAE more than cellulose more than P more than CM. This indicates that positively charged cellulose substrates are more susceptible to hydrolysis by the cellulase. This observation strengthens an earlier proposal that carboxyl groups on the enzyme are involved in substrate binding and catalytic action. Chemical modification is suggested as a method to increase the rate of enzymatic hydrolysis of cellulose, a process now in the commercial development stage. (Refs. 27).

Recent Strategies in Preparation of Cellulose Nanocrystals and Cellulose Nanofibrils Derived from Raw Cellulose Materials

Directory of Open Access Journals (Sweden)

Hongxiang Xie

2018-01-01

Full Text Available The recent strategies in preparation of cellulose nanocrystals (CNCs and cellulose nanofibrils (CNFs were described. CNCs and CNFs are two types of nanocelluloses (NCs, and they possess various superior properties, such as large specific surface area, high tensile strength and stiffness, low density, and low thermal expansion coefficient. Due to various applications in biomedical engineering, food, sensor, packaging, and so on, there are many studies conducted on CNCs and CNFs. In this review, various methods of preparation of CNCs and CNFs are summarized, including mechanical, chemical, and biological methods. The methods of pretreatment of cellulose are described in view of the benefits to fibrillation.

Inter-domain synergism is required for efficient feeding of cellulose chain into active site of cellobiohydrolase Cel7A

DEFF Research Database (Denmark)

Kont, Riin; Kari, Jeppe; Borch, Kim

2016-01-01

systems. TrCel7A consists of catalytic domain (CD) and a smaller carbohydrate binding module (CBM) connected through the glycosylated linker peptide. A tunnel shaped active site rests in the CD and contains 10 glucose unit binding sites. The active site of TrCel7A is lined with four Trp residues with two...... to Ala substitution on on-rates was strongly dependent on the presence of the CBM-linker. This compensation between CBM-linker and Trp-38 indicates synergism between CBM-linker and CD in feeding the cellulose chain into the active site. The inter-domain synergism was pre-requisite for the efficient......Structural polysaccharides like cellulose and chitin are abundant and their enzymatic degradation to soluble sugars is an important route in green chemistry. Processive glycoside hydrolases (GHs), like cellobiohydrolase Cel7A of Trichoderma reesei (TrCel7A) are key components of efficient enzyme...

Versatile High-Performance Regenerated Cellulose Membranes Prepared using Trimethylsilyl Cellulose as a Precursor

KAUST Repository

Puspasari, Tiara

2018-01-01

(TMSC), a highly soluble cellulose derivative, as a precursor for the fabrication of cellulose thin film composite membranes. TMSC is an attractive precursor to assemble thin cellulose films with good deposition behavior and film morphology; cumbersome

Cellulose digestion in Monochamus marmorator Kby. (coleoptera: Cerambycidae): role of acquired fungal enzymes

Energy Technology Data Exchange (ETDEWEB)

Kukol, J.J.; Martin, M.M.

1986-05-01

Larvae of the balsam fir sawyer, Monochamus marmorator Kby. (Coleoptera, Cerambycidae), contain midgut digestive enzymes active against hemicellulose and cellulose. Cellulases from larvae fed on balsam fir wood infected with the fungus, Trichoderma harzianum Rifai (Deuteromycetes, Moniliales, Moniliaceae), were found to be identical to those of the cellulase complex produced by this fungus when compared using chromatography, electrophoresis, and isofocusing. When larvae are maintained on a fungusfree diet, their midgut fluids lack cellulolytic activity, and they are unable to digest cellulose. Cellulolytic capacity can be restored by feeding the larvae wood permeated by fungi. We conclude that the enzymes which enable M. marmorator larvae to digest cellulose are not produced by the larvae. Instead, the larvae acquire the capacity to digest cellulose by ingesting active fungal cellulases while feeding in fungus-infected wood.

Cellulose digestion in Monochamus marmorator Kby. (coleoptera: Cerambycidae): role of acquired fungal enzymes

International Nuclear Information System (INIS)

Kukol, J.J.; Martin, M.M.

1986-01-01

Larvae of the balsam fir sawyer, Monochamus marmorator Kby. (Coleoptera, Cerambycidae), contain midgut digestive enzymes active against hemicellulose and cellulose. Cellulases from larvae fed on balsam fir wood infected with the fungus, Trichoderma harzianum Rifai (Deuteromycetes, Moniliales, Moniliaceae), were found to be identical to those of the cellulase complex produced by this fungus when compared using chromatography, electrophoresis, and isofocusing. When larvae are maintained on a fungusfree diet, their midgut fluids lack cellulolytic activity, and they are unable to digest cellulose. Cellulolytic capacity can be restored by feeding the larvae wood permeated by fungi. We conclude that the enzymes which enable M. marmorator larvae to digest cellulose are not produced by the larvae. Instead, the larvae acquire the capacity to digest cellulose by ingesting active fungal cellulases while feeding in fungus-infected wood

Herbicide effect on 14C cellulose and 14C straw decomposition in soils. Influence of phenylcarbamates on biological activity

International Nuclear Information System (INIS)

Ramanujam, T.; Bellinck, Celine; Mayaudon, J.

1979-01-01

Aniline, 2,4-D, 2,4,5-T, simazine and paraquat have no effect on cellulose decomposition in soils. The monophenylcarbamates SN 38210, IPC and CIPC, applied at 500 ppm exert per contra an important inhibitory effect. The decomposition of straw is little influenced by the phenylcarbamates, 100 ppm of 2,4-D, 2,4,5-T or simazine significantly increase the decomposition of straw in a sandy soil. The diphenylcarbamate SN 38584 has little effect on biological activity of soils; this is strongly inhibited by application of 500 ppm of SN 38210. This inhibition may be reduced by amending the soil with lignin but addition of straw or cellulose doesn't enhance biological activity of soil. Addition of 5000 ppm of soil extract or humic acids reduces somewhat the toxicity of SN 38210 [fr

Glycogen synthase kinase 3 alpha phosphorylates and regulates the osteogenic activity of Osterix.

Science.gov (United States)

Li, Hongyan; Jeong, Hyung Min; Choi, You Hee; Lee, Sung Ho; Jeong, Hye Gwang; Jeong, Tae Cheon; Lee, Kwang Youl

2013-05-10

Osteoblast-specific transcription factor Osterix is a zinc-finger transcription factor that required for osteoblast differentiation and new bone formation. The function of Osterix can be modulated by post-translational modification. Glycogen synthase kinase 3 alpha (GSK3α) is a multifunctional serine/threonine protein kinase that plays a role in the Wnt signaling pathways and is implicated in the control of several regulatory proteins and transcription factors. In the present study, we investigated how GSK3α regulates Osterix during osteoblast differentiation. Wide type GSK3α up-regulated the protein level, protein stability and transcriptional activity of Osterix. These results suggest that GSK3α regulates osteogenic activity of Osterix. Copyright © 2013 Elsevier Inc. All rights reserved.

Dual regulation of muscle glycogen synthase during exercise by activation and compartmentalization

DEFF Research Database (Denmark)

Prats, Clara; Helge, Jørn W; Nordby, Pernille

2009-01-01

Glycogen synthase (GS) is considered the rate-limiting enzyme in glycogenesis but still today there is a lack of understanding on its regulation. We have previously shown phosphorylation-dependent GS intracellular redistribution at the start of glycogen re-synthesis in rabbit skeletal muscle (Prats......, C., Cadefau, J. A., Cussó, R., Qvortrup, K., Nielsen, J. N., Wojtaszewki, J. F., Wojtaszewki, J. F., Hardie, D. G., Stewart, G., Hansen, B. F., and Ploug, T. (2005) J. Biol. Chem. 280, 23165-23172). In the present study we investigate the regulation of human muscle GS activity by glycogen, exercise......, and insulin. Using immunocytochemistry we investigate the existence and relevance of GS intracellular compartmentalization during exercise and during glycogen re-synthesis. The results show that GS intrinsic activity is strongly dependent on glycogen levels and that such regulation involves associated...

Enzymatic activity of the cellulolytic complex produced by trichoderma reesei. Enzymatic hydrolysis of cellulose

International Nuclear Information System (INIS)

Alfonsel Jaen, M.; Negro, M.J.; Saez, R.; Martin Moreno, C.

1986-01-01

The enzymatic activity characterization of the cellulolytic complex obtained from Trichoderma reese QM 9414 and the influence of the enzymatic hydrolysis conditions on the hydrolysis yield are studied. Pure cellulose and native or alkali pretreated biomass from Onopordum nervosum have been used as substrates. The values of pH, temperature, substrate concentration and enzyme-substrate ratio for the optimum activity of that complex, evaluated as glucose and reducing sugars productions, have been selected. Previous studies on enzymatic hydrolysis of O. nervosum have shown a remarkable effect of the alkaline pretreatments on the final hydrolysis yield. (author). 10 figs.; 10 refs

Enzymatic activity of the cellulolytic complex produced by Trichoderma reesei. Enzymatic hydrolysis of cellulose

International Nuclear Information System (INIS)

Alfonsel J, M.; Negro A, M. J.; Saez A, R.; Martin M, C.

1986-01-01

The enzymatic activity characterization of the cellulolytic complex obtained from Trichoderma reesei QM 9414 and the influence of the enzymatic hydrolysis conditions on the hydrolysis yield are studied. Pure cellulose and native or alkali pretreated biomass Onopordum nervosum have been used as substrates. The values of pH, temperature, substrate concentration and enzyme-substrate ratio for the optimum activity of that complex, evaluated as glucose and reducing sugars production, have been selected. Previous studies on enzymatic hydrolysis of 0. nervosum have shown a remarkable effect of the alkaline pretreatments on the final hydrolysis yield. (Author) 10 refs

Production process of a new cellulosic fiber with antimicrobial properties.

Science.gov (United States)

Zikeli, Stefan

2006-01-01

The Lyocell process (system: cellulose-water-N-methylmorpholine oxide) of Zimmer AG offers special advantages for the production of cellulose fibers. The process excels by dissolving the most diverse cellulose types as these are optimally adjusted to the process by applying different pretreatment methods. Based on this stable process, Zimmer AG's objective is to impart to the Lyocell fiber additional value to improve quality of life and thus to tap new markets for the product. Thanks to the specific incorporation of seaweed, the process allows to produce cellulose Lyocell fibers with additional and new features. They are activated in a further step - by specific charging with metal ions - in order to obtain antibacterial properties. The favorable textile properties of fibers produced by the Lyocell process are not adversely affected by the incorporation of seaweed material or by activation to obtain an antibacterial fiber so that current textile products can be made from the fibers thus produced. The antibacterial effect is achieved by metal ion activation of the Lyocell fibers with incorporated seaweed, which contrasts with the antibacterial fibers known so far. Antibacterial fibers produced by conventional methods are in part only surface finished with antibacterially active chemicals or else they are produced by incorporating organic substances with antibacterial and fungicidal effects. Being made from cellulose, the antibacterial Lyocell fiber Sea Cell Active as the basis for quality textiles exhibits a special wear comfort compared to synthetic fibers with antibacterial properties and effects. This justifies the conclusion that the Zimmer Lyocell process provides genuine value added and that it is a springboard for further applications.

Cyclic GMP-AMP synthase is activated by double-stranded DNA-induced oligomerization.

Science.gov (United States)

Li, Xin; Shu, Chang; Yi, Guanghui; Chaton, Catherine T; Shelton, Catherine L; Diao, Jiasheng; Zuo, Xiaobing; Kao, C Cheng; Herr, Andrew B; Li, Pingwei

2013-12-12

Cyclic GMP-AMP synthase (cGAS) is a cytosolic DNA sensor mediating innate antimicrobial immunity. It catalyzes the synthesis of a noncanonical cyclic dinucleotide, 2',5' cGAMP, that binds to STING and mediates the activation of TBK1 and IRF-3. Activated IRF-3 translocates to the nucleus and initiates the transcription of the IFN-β gene. The structure of mouse cGAS bound to an 18 bp dsDNA revealed that cGAS interacts with dsDNA through two binding sites, forming a 2:2 complex. Enzyme assays and IFN-β reporter assays of cGAS mutants demonstrated that interactions at both DNA binding sites are essential for cGAS activation. Mutagenesis and DNA binding studies showed that the two sites bind dsDNA cooperatively and that site B plays a critical role in DNA binding. The structure of mouse cGAS bound to dsDNA and 2',5' cGAMP provided insight into the catalytic mechanism of cGAS. These results demonstrated that cGAS is activated by dsDNA-induced oligomerization. Copyright © 2013 Elsevier Inc. All rights reserved.

Comparative Community Proteomics Demonstrates the Unexpected Importance of Actinobacterial Glycoside Hydrolase Family 12 Protein for Crystalline Cellulose Hydrolysis

Energy Technology Data Exchange (ETDEWEB)

Hiras, Jennifer; Wu, Yu-Wei; Deng, Kai; Nicora, Carrie D.; Aldrich, Joshua T.; Frey, Dario; Kolinko, Sebastian; Robinson, Errol W.; Jacobs, Jon M.; Adams, Paul D.; Northen, Trent R.; Simmons, Blake A.; Singer, Steven W.

2016-08-23

Glycoside hydrolases (GHs) are key enzymes in the depolymerization of plant-derived cellulose, a process central to the global carbon cycle and the conversion of plant biomass to fuels and chemicals. A limited number of GH families hydrolyze crystalline cellulose, often by a processive mechanism along the cellulose chain. During cultivation of thermophilic cellulolytic microbial communities, substantial differences were observed in the crystalline cellulose saccharification activities of supernatants recovered from divergent lineages. Comparative community proteomics identified a set of cellulases from a population closely related to actinobacteriumThermobispora bisporathat were highly abundant in the most active consortium. Among the cellulases fromT. bispora, the abundance of a GH family 12 (GH12) protein correlated most closely with the changes in crystalline cellulose hydrolysis activity. This result was surprising since GH12 proteins have been predominantly characterized as enzymes active on soluble polysaccharide substrates. Heterologous expression and biochemical characterization of the suite ofT. bisporahydrolytic cellulases confirmed that the GH12 protein possessed the highest activity on multiple crystalline cellulose substrates and demonstrated that it hydrolyzes cellulose chains by a predominantly random mechanism. This work suggests that the role of GH12 proteins in crystalline cellulose hydrolysis by cellulolytic microbes should be reconsidered.

IMPORTANCECellulose is the most abundant organic polymer on earth, and its enzymatic hydrolysis is a key reaction in the global carbon cycle and the conversion of plant biomass to biofuels. The glycoside hydrolases that depolymerize crystalline cellulose have been primarily characterized from isolates. In this study, we demonstrate that adapting microbial consortia from compost to grow on crystalline cellulose

Drug-loaded Cellulose Acetate and Cellulose Acetate Butyrate Films ...

African Journals Online (AJOL)

The purpose of this research work was to evaluate the contribution of formulation variables on release properties of matrix type ocular films containing chloramphenicol as a model drug. This study investigated the use of cellulose acetate and cellulose acetate butyrate as film-forming agents in development of ocular films.

Nano-tubular cellulose for bioprocess technology development.

Directory of Open Access Journals (Sweden)

Athanasios A Koutinas

Full Text Available Delignified cellulosic material has shown a significant promotional effect on the alcoholic fermentation as yeast immobilization support. However, its potential for further biotechnological development is unexploited. This study reports the characterization of this tubular/porous cellulosic material, which was done by SEM, porosimetry and X-ray powder diffractometry. The results showed that the structure of nano-tubular cellulose (NC justifies its suitability for use in "cold pasteurization" processes and its promoting activity in bioprocessing (fermentation. The last was explained by a glucose pump theory. Also, it was demonstrated that crystallization of viscous invert sugar solutions during freeze drying could not be otherwise achieved unless NC was present. This effect as well as the feasibility of extremely low temperature fermentation are due to reduction of the activation energy, and have facilitated the development of technologies such as wine fermentations at home scale (in a domestic refrigerator. Moreover, NC may lead to new perspectives in research such as the development of new composites, templates for cylindrical nano-particles, etc.

The mechanism of Acetobacter xylinum cellulose biosynthesis: direction of chain elongation and the role of lipid pyrophosphate intermediates in the cell membrane

International Nuclear Information System (INIS)

Han, N.S.; Robyt, J.F.

1998-01-01

The biosynthesis of Acetobacter xylinum ATCC 10821 cellulose has been studied with resting cells and a membrane preparation using 14 C-pulse and chase reactions, with d-glucose and UDPGlc, respectively. Cellulose was biosynthesized from UDPGlc, and it was found to be tightly associated with both the cells and the membrane. The cellulose chains could be released from the cells and the membrane preparation by treating at pH 2, 100 C for 20 min. The cellulose chains that were released from the pulse and pulse-chase reactions were purified and separated from any low molecular weight substances by gel chromatography on Bio-Gel P4. They were then reduced with sodium borohydride and hydrolyzed with 4 M trifluoroacetic acid at 121 C for 2 h. Labeled products from the acid hydrolyzates were separated by paper chromatography and found to be d-glucose and d-glucitol. The amount of radioactivity in the products was determined by liquid scintillation counting. It was found that the pulsed products from the resting cells gave a ratio of d-[ 14 C]glucitol to d-[ 14 C]glucose of 1:11, and after chasing, the ratio decreased to 1:36. The pulsed products from the membrane gave a ratio of d-[ 14 C]glucitol to d-[ 14 C]glucose of 1:12, and after chasing for 5 min the ratio decreased to 1:43, and after 10 min, the ratio decreased to 1:66. These results show that the labeled d-glucitol obtained from the reducing end of the cellulose chain is chased into the interior of the cellulose chain during synthesis, showing that the cellulose chain is elongated from the reducing end. An insertion mechanism for the synthesis of cellulose from UDPGlc is proposed that involves lipid pyrophosphate glycosyl intermediates and three membrane enzymes: lipid phosphate:UDPGlc phosphotransferase, cellulose synthase, and lipid pyrophosphate phosphohydrolase. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

Isolation, characterization, and mechanistic studies of (-)-alpha-gurjunene synthase from Solidago canadensis.

Science.gov (United States)

Schmidt, C O; Bouwmeester, H J; Bülow, N; König, W A

1999-04-15

The leaves of the composite Solidago canadensis (goldenrod) were shown to contain (-)-alpha-gurjunene synthase activity. This sesquiterpene is likely to be the precursor for cyclocolorenone, a sesquiterpene ketone present in high amounts in S. canadensis leaves. (-)-alpha-Gurjunene synthase was purified to apparent homogeneity (741-fold) by anion-exchange chromatography (on several matrices), dye ligand chromatography, hydroxylapatite chromatography, and gel filtration. Chromatography on a gel filtration matrix indicated a native molecular mass of 48 kDa, and SDS-PAGE showed the enzyme to be composed of one subunit with a denatured mass of 60 kDa. Its maximum activity was observed at pH 7.8 in the presence of 10 mM Mg2+ and the KM value for the substrate farnesyl diphosphate was 5.5 microM. Over a range of purification steps (-)-alpha-gurjunene and (+)-gamma-gurjunene synthase activities copurified. In addition, the product ratio of the enzyme activity under several different assay conditions was always 91% (-)-alpha-gurjunene and 9% (+)-gamma-gurjunene. This suggests that the formation of these two structurally related products is catalyzed by one enzyme. For further confirmation, we carried out a number of mechanistic studies with (-)-alpha-gurjunene synthase, in which an enzyme preparation was incubated with deuterated substrate analogues. Based on mass spectrometry analysis of the products formed, a cyclization mechanism was postulated which makes it plausible that the synthase catalyzes the formation of both sesquiterpenes. Copyright 1999 Academic Press.

ATP Synthase, a Target for Dementia and Aging?

Science.gov (United States)

Larrick, James W; Larrick, Jasmine W; Mendelsohn, Andrew R

2018-02-01

Advancing age is the biggest risk factor for development for the major life-threatening diseases in industrialized nations accounting for >90% of deaths. Alzheimer's dementia (AD) is among the most devastating. Currently approved therapies fail to slow progression of the disease, providing only modest improvements in memory. Recently reported work describes mechanistic studies of J147, a promising therapeutic molecule previously shown to rescue the severe cognitive deficits exhibited by aged, transgenic AD mice. Apparently, J147 targets the mitochondrial alpha-F1-ATP synthase (ATP5A). Modest inhibition of the ATP synthase modulates intracellular calcium to activate AMP-activated protein kinase to inhibit mammalian target of rapamycin, a known mechanism of lifespan extension from worms to mammals.

Adsorptive removal of Lead from water by the effective and reusable magnetic cellulose nanocomposite beads entrapping activated bentonite.

Science.gov (United States)

Luo, Xiaogang; Lei, Xiaojuan; Xie, Xiuping; Yu, Bo; Cai, Ning; Yu, Faquan

2016-10-20

Many efforts have been driven to decontaminate the drinking water, and the development of efficient adsorbents with the advantages of cost-effectiveness and operating convenience for the removal of Pb(2+) from water is a major challenge. This work was aimed to explore the possibility of using cellulose-based adsorbents for efficient adsorption of Pb(2+). The millimeter-scale magnetic cellulose-based nanocomposite beads were fabricated via an optimal extrusion dropping technology by blending cellulose with the carboxyl-functionalized magnetite nanoparticles and acid-activated bentonite in NaOH/urea aqueous solution, and then they had been tested to evaluate the effectiveness in the removal of Pb(2+) from water. The effects of contact time, initial heavy metal ion concentrations, adsorption isotherms and solution pH on the sorption behavior were studied. The thermodynamic parameters (ΔG, ΔH and ΔS) indicated that the adsorption processes were feasible, spontaneous, endothermic and mainly controlled by chemical mechanisms. The reusability of the adsorbent was also studied. Copyright © 2016 Elsevier Ltd. All rights reserved.

Using heavy-ion mutagenesis technology to select cellulose enzyme vitality of mutants of Aspergillium niger

International Nuclear Information System (INIS)

Tang Jiahui; Yang Fumin; Wang Shuyang

2012-01-01

In order to improve the cellulose ion beam at 20, 40, 60, 80, 100, 120Gy and 140 enzyme vitality of Aspergillus niger (=AS3.316), heavy Gy doses was used for inducing mutation. Higher cellulose enzyme vitality strains were screened through the primary screening and secondary screening. The result showed that 5 mutants T2-1, T3-1, T5-1, T6-3, T6-4 were selected, and T6-4 had the highest cellulose enzyme activity. The activity of filter paper cellulose enzyme, endo-glucanase, exo-glucanase and 13-glucosidase of T6-4 was 61.3, 116.2, 29.9 U/mL and 35.9 U/mL respectively. Compared with the original A. niger (=AS3.316), the cellulose enzyme activity was increased by 3.5, 3.78, 2.76 and 2.52 times in turn. The activity of cellulose enzyme of the rest mutants sorted from strong to the weak were T6-3T5-1T3-1T2-1. The dose at 120 Gy showed the best mutagenesis effect. Mutants had different degree of changes in the genetic stability, but overall, the performance showed relatively stable

Structure of the dimeric form of CTP synthase from Sulfolobus solfataricus

DEFF Research Database (Denmark)

Lauritsen, Iben; Willemoës, Martin; Jensen, Kaj Frank

2011-01-01

CTP synthase catalyzes the last committed step in de novo pyrimidine-nucleotide biosynthesis. Active CTP synthase is a tetrameric enzyme composed of a dimer of dimers. The tetramer is favoured in the presence of the substrate nucleotides ATP and UTP; when saturated with nucleotide, the tetramer...... completely dominates the oligomeric state of the enzyme. Furthermore, phosphorylation has been shown to regulate the oligomeric states of the enzymes from yeast and human. The crystal structure of a dimeric form of CTP synthase from Sulfolobus solfataricus has been determined at 2.5 Å resolution...

The Tomato Terpene Synthase Gene Family1[W][OA

Science.gov (United States)

Falara, Vasiliki; Akhtar, Tariq A.; Nguyen, Thuong T.H.; Spyropoulou, Eleni A.; Bleeker, Petra M.; Schauvinhold, Ines; Matsuba, Yuki; Bonini, Megan E.; Schilmiller, Anthony L.; Last, Robert L.; Schuurink, Robert C.; Pichersky, Eran

2011-01-01

Compounds of the terpenoid class play numerous roles in the interactions of plants with their environment, such as attracting pollinators and defending the plant against pests. We show here that the genome of cultivated tomato (Solanum lycopersicum) contains 44 terpene synthase (TPS) genes, including 29 that are functional or potentially functional. Of these 29 TPS genes, 26 were expressed in at least some organs or tissues of the plant. The enzymatic functions of eight of the TPS proteins were previously reported, and here we report the specific in vitro catalytic activity of 10 additional tomato terpene synthases. Many of the tomato TPS genes are found in clusters, notably on chromosomes 1, 2, 6, 8, and 10. All TPS family clades previously identified in angiosperms are also present in tomato. The largest clade of functional TPS genes found in tomato, with 12 members, is the TPS-a clade, and it appears to encode only sesquiterpene synthases, one of which is localized to the mitochondria, while the rest are likely cytosolic. A few additional sesquiterpene synthases are encoded by TPS-b clade genes. Some of the tomato sesquiterpene synthases use z,z-farnesyl diphosphate in vitro as well, or more efficiently than, the e,e-farnesyl diphosphate substrate. Genes encoding monoterpene synthases are also prevalent, and they fall into three clades: TPS-b, TPS-g, and TPS-e/f. With the exception of two enzymes involved in the synthesis of ent-kaurene, the precursor of gibberellins, no other tomato TPS genes could be demonstrated to encode diterpene synthases so far. PMID:21813655

Heme A synthase in bacteria depends on one pair of cysteinyls for activity.

Science.gov (United States)

Lewin, Anna; Hederstedt, Lars

2016-02-01

Heme A is a prosthetic group unique for cytochrome a-type respiratory oxidases in mammals, plants and many microorganisms. The poorly understood integral membrane protein heme A synthase catalyzes the synthesis of heme A from heme O. In bacteria, but not in mitochondria, this enzyme contains one or two pairs of cysteine residues that are present in predicted hydrophilic polypeptide loops on the extracytoplasmic side of the membrane. We used heme A synthase from the eubacterium Bacillus subtilis and the hyperthermophilic archeon Aeropyrum pernix to investigate the functional role of these cysteine residues. Results with B. subtilis amino acid substituted proteins indicated the pair of cysteine residues in the loop connecting transmembrane segments I and II as being essential for catalysis but not required for binding of the enzyme substrate, heme O. Experiments with isolated A. pernix and B. subtilis heme A synthase demonstrated that a disulfide bond can form between the cysteine residues in the same loop and also between loops showing close proximity of the two loops in the folded enzyme protein. Based on the findings, we propose a classification scheme for the four discrete types of heme A synthase found so far in different organisms and propose that essential cysteinyls mediate transfer of reducing equivalents required for the oxygen-dependent catalysis of heme A synthesis from heme O. Copyright © 2015 Elsevier B.V. All rights reserved.

Nitrite reductase activity and inhibition of H₂S biogenesis by human cystathionine ß-synthase.

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Carmen Gherasim

Full Text Available Nitrite was recognized as a potent vasodilator >130 years and has more recently emerged as an endogenous signaling molecule and modulator of gene expression. Understanding the molecular mechanisms that regulate nitrite metabolism is essential for its use as a potential diagnostic marker as well as therapeutic agent for cardiovascular diseases. In this study, we have identified human cystathionine ß-synthase (CBS as a new player in nitrite reduction with implications for the nitrite-dependent control of H₂S production. This novel activity of CBS exploits the catalytic property of its unusual heme cofactor to reduce nitrite and generate NO. Evidence for the possible physiological relevance of this reaction is provided by the formation of ferrous-nitrosyl (Fe(II-NO CBS in the presence of NADPH, the human diflavin methionine synthase reductase (MSR and nitrite. Formation of Fe(II-NO CBS via its nitrite reductase activity inhibits CBS, providing an avenue for regulating biogenesis of H₂S and cysteine, the limiting reagent for synthesis of glutathione, a major antioxidant. Our results also suggest a possible role for CBS in intracellular NO biogenesis particularly under hypoxic conditions. The participation of a regulatory heme cofactor in CBS in nitrite reduction is unexpected and expands the repertoire of proteins that can liberate NO from the intracellular nitrite pool. Our results reveal a potential molecular mechanism for cross-talk between nitrite, NO and H₂S biology.

A small RNA activates CFA synthase by isoform-specific mRNA stabilization.

Science.gov (United States)

Fröhlich, Kathrin Sophie; Papenfort, Kai; Fekete, Agnes; Vogel, Jörg

2013-11-13

Small RNAs use a diversity of well-characterized mechanisms to repress mRNAs, but how they activate gene expression at the mRNA level remains not well understood. The predominant activation mechanism of Hfq-associated small RNAs has been translational control whereby base pairing with the target prevents the formation of an intrinsic inhibitory structure in the mRNA and promotes translation initiation. Here, we report a translation-independent mechanism whereby the small RNA RydC selectively activates the longer of two isoforms of cfa mRNA (encoding cyclopropane fatty acid synthase) in Salmonella enterica. Target activation is achieved through seed pairing of the pseudoknot-exposed, conserved 5' end of RydC to an upstream region of the cfa mRNA. The seed pairing stabilizes the messenger, likely by interfering directly with RNase E-mediated decay in the 5' untranslated region. Intriguingly, this mechanism is generic such that the activation is equally achieved by seed pairing of unrelated small RNAs, suggesting that this mechanism may be utilized in the design of RNA-controlled synthetic circuits. Physiologically, RydC is the first small RNA known to regulate membrane stability.

Microwave-Assisted Combustion Synthesis of Nano Iron Oxide/Iron-Coated Activated Carbon, Anthracite, Cellulose Fiber, and Silica, with Arsenic Adsorption Studies

Directory of Open Access Journals (Sweden)

Mallikarjuna N. Nadagouda

2011-01-01

Full Text Available Combustion synthesis of iron oxide/iron coated carbons such as activated carbon, anthracite, cellulose fiber, and silica is described. The reactions were carried out in alumina crucibles using a Panasonic kitchen microwave with inverter technology, and the reaction process was completed within a few minutes. The method used no additional fuel and nitrate, which is present in the precursor itself, to drive the reaction. The obtained samples were then characterized with X-ray mapping, scanning electron microscopy (SEM, energy dispersive X-ray analysis (EDS, selected area diffraction pattern (SAED, transmission electron microscopy (TEM, X-ray diffraction (XRD, and inductively coupled plasma (ICP spectroscopy. The size of the iron oxide/iron nanoparticle-coated activated carbon, anthracite, cellulose fiber, and silica samples were found to be in the nano range (50–400 nm. The iron oxide/iron nanoparticles mostly crystallized into cubic symmetry which was confirmed by SAED. The XRD pattern indicated that iron oxide/iron nano particles existed in four major phases. That is, γ-Fe2O3, α-Fe2O3, Fe3O4, and Fe. These iron-coated activated carbon, anthracite, cellulose fiber, and silica samples were tested for arsenic adsorption through batch experiments, revealing that few samples had significant arsenic adsorption.

Alexa Fluor-labeled Fluorescent Cellulose Nanocrystals for Bioimaging Solid Cellulose in Spatially Structured Microenvironments

Energy Technology Data Exchange (ETDEWEB)

Grate, Jay W.; Mo, Kai-For; Shin, Yongsoon; Vasdekis, Andreas; Warner, Marvin G.; Kelly, Ryan T.; Orr, Galya; Hu, Dehong; Dehoff, Karl J.; Brockman, Fred J.; Wilkins, Michael J.

2015-03-18

Cellulose nanocrystal materials have been labeled with modern Alexa Fluor dyes in a process that first links the dye to a cyanuric chloride molecule. Subsequent reaction with cellulose nanocrystals provides dyed solid microcrystalline cellulose material that can be used for bioimaging and suitable for deposition in films and spatially structured microenvironments. It is demonstrated with single molecular fluorescence microscopy that these films are subject to hydrolysis by cellulose enzymes.

Homogeneous preparation of cellulose acetate propionate (CAP) and cellulose acetate butyrate (CAB) from sugarcane bagasse cellulose in ionic liquid.

Science.gov (United States)

Huang, Kelin; Wang, Ben; Cao, Yan; Li, Huiquan; Wang, Jinshu; Lin, Weijiang; Mu, Chaoshi; Liao, Dankui

2011-05-25

Cellulose acetate butyrate (CAB) and cellulose acetate propionate (CAP) were prepared homogeneously in a 1-allyl-3-methylimidazolium chloride (AmimCl) ionic liquid system from sugarcane bagasse (SB). The reaction temperature, reaction time, and molar ratio of butyric (propionic) anhydride/anhydroglucose units in the cellulose affect the butyryl (B) or propionyl (P) content of CAB or CAP samples. The (13)C NMR data revealed the distribution of the substituents of CAB and CAP. The thermal stability of sugar cane bagasse cellulose was found by thermogravimetric analysis to have decreased after chemical modification. After reaction, the ionic liquid was effectively recycled and reused. This study provides a new way for high-value-added utilization of SB and realizing the objective of turning waste into wealth.

The CSLA and CSLC Families: Recent Advances and Future Perspectives

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Aaron Howard Liepman

2012-05-01

Full Text Available The CELLULOSE SYNTHASE (CESA superfamily of proteins contains several sub-families of closely related CELLULOSE SYNTHASE-LIKE (CSL sequences, Among these, the CSLA and CSLC families are closely related to each other and are the most evolutionarily divergent from the CESA family. Significant progress has been made with the functional characterization of CSLA and CSLC genes, which have been shown to encode enzymes with 1,4-B-glycan synthase activities involved in the biosynthesis of mannan and possibly xyloglucan backbones, respectively. This review examines recent work on the CSLA and CSLC families from evolutionary, molecular, and biochemical perspectives. We pose a series of questions, whose answers likely will provide further insight about the specific functions of members of the CSLA and CSLC families and about plant polysaccharide biosynthesis is general.

Electrospun curcumin-loaded cellulose acetate/polyvinylpyrrolidone fibrous materials with complex architecture and antibacterial activity

International Nuclear Information System (INIS)

Tsekova, Petya B.; Spasova, Mariya G.; Manolova, Nevena E.; Markova, Nadya D.; Rashkov, Iliya B.

2017-01-01

Novel fibrous materials from cellulose acetate (CA) and polyvinylpyrrolidone (PVP) containing curcumin (Curc) with original design were prepared by one-pot electrospinning or dual spinneret electrospinning. The electrospun materials were characterized by scanning electron microscopy (SEM), fluorescence microscopy, Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV–Vis), differential scanning calorimetry (DSC), water contact angle measurements, and microbiological tests. It was found that the incorporation of Curc into the CA and PVP solutions resulted in an increase of the solution viscosity and obtaining fibers with larger diameters (ca. 1.5 μm) compared to the neat CA (ca. 800 nm) and PVP fibers (ca. 500 nm). The incorporation of PVP resulted in increased hydrophilicity of the fibers and in faster Curc release. Curc was found in the amorphous state in the Curc-containing fibers and these mats exhibited antibacterial activity against Staphylococcus aureus (S. aureus). The results suggest that, due to their complex architecture, the obtained new antibacterial materials are suitable for wound dressing applications, which necessitate diverse release behaviors of the bioactive compound. - Highlights: • Novel curcumin-loaded materials based on cellulose acetate and polyvinylpyrrolidone were prepared by electrospinning. • Using one-pot or dual spinneret electrospinning enabled modulating drug release. • The incorporation of polyvinylpyrrolidone resulted in faster curcumin release. • The curcumin-containing mats exhibited antibacterial activity thus rendering them suitable for wound dressing applications.

Electrospun curcumin-loaded cellulose acetate/polyvinylpyrrolidone fibrous materials with complex architecture and antibacterial activity

Energy Technology Data Exchange (ETDEWEB)

Tsekova, Petya B.; Spasova, Mariya G.; Manolova, Nevena E. [Laboratory of Bioactive Polymers, Institute of Polymers, Bulgarian Academy of Sciences, Acad. G. Bonchev St, bl. 103A, BG-1113 Sofia (Bulgaria); Markova, Nadya D. [Institute of Microbiology, Bulgarian Academy of Sciences, Acad. G. Bonchev St, bl. 26, BG-1113 Sofia (Bulgaria); Rashkov, Iliya B., E-mail: rashkov@polymer.bas.bg [Laboratory of Bioactive Polymers, Institute of Polymers, Bulgarian Academy of Sciences, Acad. G. Bonchev St, bl. 103A, BG-1113 Sofia (Bulgaria)

2017-04-01

Novel fibrous materials from cellulose acetate (CA) and polyvinylpyrrolidone (PVP) containing curcumin (Curc) with original design were prepared by one-pot electrospinning or dual spinneret electrospinning. The electrospun materials were characterized by scanning electron microscopy (SEM), fluorescence microscopy, Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV–Vis), differential scanning calorimetry (DSC), water contact angle measurements, and microbiological tests. It was found that the incorporation of Curc into the CA and PVP solutions resulted in an increase of the solution viscosity and obtaining fibers with larger diameters (ca. 1.5 μm) compared to the neat CA (ca. 800 nm) and PVP fibers (ca. 500 nm). The incorporation of PVP resulted in increased hydrophilicity of the fibers and in faster Curc release. Curc was found in the amorphous state in the Curc-containing fibers and these mats exhibited antibacterial activity against Staphylococcus aureus (S. aureus). The results suggest that, due to their complex architecture, the obtained new antibacterial materials are suitable for wound dressing applications, which necessitate diverse release behaviors of the bioactive compound. - Highlights: • Novel curcumin-loaded materials based on cellulose acetate and polyvinylpyrrolidone were prepared by electrospinning. • Using one-pot or dual spinneret electrospinning enabled modulating drug release. • The incorporation of polyvinylpyrrolidone resulted in faster curcumin release. • The curcumin-containing mats exhibited antibacterial activity thus rendering them suitable for wound dressing applications.

A co-production of sugars, lignosulfonates, cellulose, and cellulose nanocrystals from ball-milled woods.

Science.gov (United States)

Du, Lanxing; Wang, Jinwu; Zhang, Yang; Qi, Chusheng; Wolcott, Michael P; Yu, Zhiming

2017-08-01

This study demonstrated the technical potential for the large-scale co-production of sugars, lignosulfonates, cellulose, and cellulose nanocrystals. Ball-milled woods with two particle sizes were prepared by ball milling for 80min or 120min (BMW 80 , BMW 120 ) and then enzymatically hydrolyzed. 78.3% cellulose conversion of BMW 120 was achieved, which was three times as high as the conversion of BMW 80 . The hydrolyzed residues (HRs) were neutrally sulfonated cooking. 57.72g/L and 88.16g/L lignosulfonate concentration, respectively, were harvested from HR 80 and HR 120 , and 42.6±0.5% lignin were removed. The subsequent solid residuals were purified to produce cellulose and then this material was acid-hydrolyzed to produce cellulose nanocrystals. The BMW 120 maintained smaller particle size and aspect ratio during each step of during the multiple processes, while the average aspect ratio of its cellulose nanocrystals was larger. The crystallinity of both materials increased with each step of wet processing, reaching to 74% for the cellulose. Copyright © 2017 Elsevier Ltd. All rights reserved.

Versatile High-Performance Regenerated Cellulose Membranes Prepared using Trimethylsilyl Cellulose as a Precursor

KAUST Repository

Puspasari, Tiara

2018-05-01

Cellulose has emerged as an indispensable membrane material due to its abundant availability, low cost, fascinating physiochemical properties and environment benignancy. However, it is believed that the potential of this polymer is not fully explored yet due to its insolubility in the common organic solvents, encouraging the use of derivatization-regeneration method as a viable alternative to the direct dissolution in exotic or reactive solvents. In this work, we use trimethylsilyl cellulose (TMSC), a highly soluble cellulose derivative, as a precursor for the fabrication of cellulose thin film composite membranes. TMSC is an attractive precursor to assemble thin cellulose films with good deposition behavior and film morphology; cumbersome solvents used in the one step cellulose processing are avoided. This derivative is prepared from cellulose by the known silylation reaction. The complete transformation of TMSC back into cellulose after the membrane formation is carried out by vapor-phase acid treatment, which is simple, scalable and reproducible. This process along with the initial TMSC concentration determines the membrane sieving characteristics. Unlike the typical regenerated cellulose membranes with meso- or macropores, membranes regenerated from TMSC display micropores suitable for the selective separation of nanomolecules in aqueous and organic solvent nanofiltration. The membranes introduced in this thesis represent the first polymeric membranes ever reported for highly selective separation of similarly sized small organic molecules based on charge and size differences with outstanding fluxes. Owing to its strong hydrophilic and amorphous character, the membranes also demonstrate excellent air-dehumidification performance as compared to previously reported thin film composite membranes. Moreover, the use of TMSC enables the creation of the previously unfeasible cellulose–polydimethylsiloxane (PDMS) and cellulose–polyethyleneimine (PEI) blend membranes

Physicochemical analysis of cellulose from microalgae ...

African Journals Online (AJOL)

USER

2016-06-15

Jun 15, 2016 ... The extraction method of algae cellulose was a modification of ... triplicate. Characterization of cellulose. Analysis of ... The current analysis of the cellulose extracted .... Cellulose nanomaterials review: structure, properties and.

Monoterpene and sesquiterpene synthases and the origin of terpene skeletal diversity in plants.

Science.gov (United States)

Degenhardt, Jörg; Köllner, Tobias G; Gershenzon, Jonathan

2009-01-01

The multitude of terpene carbon skeletons in plants is formed by enzymes known as terpene synthases. This review covers the monoterpene and sesquiterpene synthases presenting an up-to-date list of enzymes reported and evidence for their ability to form multiple products. The reaction mechanisms of these enzyme classes are described, and information on how terpene synthase proteins mediate catalysis is summarized. Correlations between specific amino acid motifs and terpene synthase function are described, including an analysis of the relationships between active site sequence and cyclization type and a discussion of whether specific protein features might facilitate multiple product formation.

Cellulose hydrolysis by fungi. 2. Cellulase production by Trichoderma harzianum in liquid medium fermentation

Energy Technology Data Exchange (ETDEWEB)

Roussos, S.; Raimbault, M. (Laboratoire de Microbiologie ORSTOM, Centre de Recherche IRCHA, 91 - Vert-le-Petit (France))

Microcrystalline cellulose (cellulose Avicel, Merck) supported growth of Trichoderma harzianum and induced production of cellulases in liquid cultures. After 50 h growth, the total cellulasic activities present in both the supernatant and the mycelium were 3,000 IU/l of carboxymethyl cellulose, 400 IU/l of filter paper activity, and 4 IU/l of cotton activity corresponding to 1.7 g/l of proteins. Cellulase production could be increased by a preliminary treatment of cellulose, and pH regulation during growth. The influence of inoculum concentration was studied and an optimum of 3 X 10/sup 7/ conidia/g dry weight of substrate was demonstrated. Using a synthetic culture medium, a soluble factor of germination was demonstrated which could be leached out by 3 successive washings of conidia.

An Investigation of Cellulose Digesting Bacteria in the Panda Gut Microbiome

Science.gov (United States)

Lu, M.; Leung, F. C.

2014-12-01

The Giant Panda (Ailuropoda melanoleuca) diet consists primarily of bamboo leaves, stems and shoots. However, the Giant Panda lacks genes for the enzymes needed to digest cellulose, the core component of bamboo. Thus, it is hypothesized that the cellulolytic digestion necessary for maintaining the Giant Panda diet is carried out by microbial symbionts in the panda gut microbiota. Fecal microbiota is used as surrogate index for gut microbiota since the Giant Panda is listed by the World Conservation Union as a Threatened Species. Two bacterial isolates with potential cellulolytic activity were isolated from Giant Panda fecal samples and cultured on selective media CMC (carboxymethyl cellulose) agar and CMC-Congo Red agar using various methods of inoculation. After incubation, clearance zones around colonies were observed and used as qualitative assays for cellulose digestion. Polymerase chain reaction amplification of the 16S rRNA gene was completed and species identification was done based on the BLAST result of 16S rRNA sequence obtained using Sanger sequencing. Once the cellulase activity is confirmed, genomic DNA of the bacteria will be extracted and used for whole genome shotgun sequencing. Illumina next generation sequencing platform will be adopted as it yields high-throughput information, providing a better understanding of cellulose digestion and the molecular genetic pathways to renewable sources of biofuels. Researchers have identified multiple cellulose-digesting microbes in the Giant Panda gut, but few have applied such bacteria in converting cellulose into glucose to create biofuel. Cellulosic ethanol, a biofuel, is produced through the fermentation of lignocellulosic biomasses. This anaerobic process is aided by cellulose-digesting enzymes. Certain microbes, such as those present in the Giant Panda gut, can produce enzymes that cleave the glycosidic bonds of cellulose (C6H10O5) into glucose molecules (C6H12O6), which can then be fermented into ethanol

Novel Cu@SiO2/bacterial cellulose nanofibers: Preparation and excellent performance in antibacterial activity

International Nuclear Information System (INIS)

Ma, Bo; Huang, Yang; Zhu, Chunlin; Chen, Chuntao; Chen, Xiao; Fan, Mengmeng; Sun, Dongping

2016-01-01

The antibacterial composite based on bacterial cellulose (BC) was successfully prepared by in-situ synthesis of SiO 2 coated Cu nanoparticles (Cu@SiO 2 /BC) and its properties were characterized. Its chemical structures and morphologies were evaluated by Fourier transformation infrared spectrum (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The results demonstrated that the SiO 2 coated Cu particles were well homogeneously precipitated on the surface of BC. The Cu@SiO 2 /BC was more resistant to oxidation than the Cu nanoparticles impregnated into BC (Cu/BC) and then Cu@SiO 2 /BC could prolong the antimicrobial activity against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). - Graphical abstract: Schematic illustration of the preparation of Cu@SiO 2 /BC. Due to its unique structure, the Cu@SiO 2 /BC membrane shows excellent antibacterial effects and can be used for a long time. - Highlights: • This work paves the novel way to fabricate antibacterial nanomaterial with good efficiency. • We prepare the antibacterial membrane based on bacterial cellulose by in-situ synthesis of SiO 2 -coated Cu nanoparticles. • The antibacterial membrane is more resistant to oxidation and can prolong the antimicrobial activity.

Long-term effects of rapamycin treatment on insulin mediated phosphorylation of Akt/PKB and glycogen synthase activity

International Nuclear Information System (INIS)

Varma, Shailly; Shrivastav, Anuraag; Changela, Sheena; Khandelwal, Ramji L.

2008-01-01

Protein kinase B (Akt/PKB) is a Ser/Thr kinase that is involved in the regulation of cell proliferation/survival through mammalian target of rapamycin (mTOR) and the regulation of glycogen metabolism through glycogen synthase kinase 3β (GSK-3β) and glycogen synthase (GS). Rapamycin is an inhibitor of mTOR. The objective of this study was to investigate the effects of rapamycin pretreatment on the insulin mediated phosphorylation of Akt/PKB phosphorylation and GS activity in parental HepG2 and HepG2 cells with overexpression of constitutively active Akt1/PKB-α (HepG2-CA-Akt/PKB). Rapamycin pretreatment resulted in a decrease (20-30%) in the insulin mediated phosphorylation of Akt1 (Ser 473) in parental HepG2 cells but showed an upregulation of phosphorylation in HepG2-CA-Akt/PKB cells. Rictor levels were decreased (20-50%) in parental HepG2 cells but were not significantly altered in the HepG2-CA-Akt/PKB cells. Furthermore, rictor knockdown decreased the phosphorylation of Akt (Ser 473) by 40-60% upon rapamycin pretreatment. GS activity followed similar trends as that of phosphorylated Akt and so with rictor levels in these cells pretreated with rapamycin; parental HepG2 cells showed a decrease in GS activity, whereas as HepG2-CA-Akt/PKB cells showed an increase in GS activity. The changes in the levels of phosphorylated Akt/PKB (Ser 473) correlated with GS and protein phoshatase-1 activity

Glycogen synthase from the parabasalian parasite Trichomonas vaginalis: An unusual member of the starch/glycogen synthase family.

Science.gov (United States)

Wilson, Wayne A; Pradhan, Prajakta; Madhan, Nayasha; Gist, Galen C; Brittingham, Andrew

2017-07-01

Trichomonas vaginalis, a parasitic protist, is the causative agent of the common sexually-transmitted infection trichomoniasis. The organism has long been known to synthesize substantial glycogen as a storage polysaccharide, presumably mobilizing this compound during periods of carbohydrate limitation, such as might be encountered during transmission between hosts. However, little is known regarding the enzymes of glycogen metabolism in T. vaginalis. We had previously described the identification and characterization of two forms of glycogen phosphorylase in the organism. Here, we measure UDP-glucose-dependent glycogen synthase activity in cell-free extracts of T. vaginalis. We then demonstrate that the TVAG_258220 open reading frame encodes a glycosyltransferase that is presumably responsible for this synthetic activity. We show that expression of TVAG_258220 in a yeast strain lacking endogenous glycogen synthase activity is sufficient to restore glycogen accumulation. Furthermore, when TVAG_258220 is expressed in bacteria, the resulting recombinant protein has glycogen synthase activity in vitro, transferring glucose from either UDP-glucose or ADP-glucose to glycogen and using both substrates with similar affinity. This protein is also able to transfer glucose from UDP-glucose or ADP-glucose to maltose and longer oligomers of glucose but not to glucose itself. However, with these substrates, there is no evidence of processivity and sugar transfer is limited to between one and three glucose residues. Taken together with our earlier work on glycogen phosphorylase, we are now well positioned to define both how T. vaginalis synthesizes and utilizes glycogen, and how these processes are regulated. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

In vivo inhibition of the mitochondrial H+-ATP synthase in neurons promotes metabolic preconditioning.

Science.gov (United States)

Formentini, Laura; Pereira, Marta P; Sánchez-Cenizo, Laura; Santacatterina, Fulvio; Lucas, José J; Navarro, Carmen; Martínez-Serrano, Alberto; Cuezva, José M

2014-04-01

A key transducer in energy conservation and signaling cell death is the mitochondrial H(+)-ATP synthase. The expression of the ATPase inhibitory factor 1 (IF1) is a strategy used by cancer cells to inhibit the activity of the H(+)-ATP synthase to generate a ROS signal that switches on cellular programs of survival. We have generated a mouse model expressing a mutant of human IF1 in brain neurons to assess the role of the H(+)-ATP synthase in cell death in vivo. The expression of hIF1 inhibits the activity of oxidative phosphorylation and mediates the shift of neurons to an enhanced aerobic glycolysis. Metabolic reprogramming induces brain preconditioning affording protection against quinolinic acid-induced excitotoxicity. Mechanistically, preconditioning involves the activation of the Akt/p70S6K and PARP repair pathways and Bcl-xL protection from cell death. Overall, our findings provide the first in vivo evidence highlighting the H(+)-ATP synthase as a target to prevent neuronal cell death.

Inter-domain Synergism Is Required for Efficient Feeding of Cellulose Chain into Active Site of Cellobiohydrolase Cel7A.

Science.gov (United States)

Kont, Riin; Kari, Jeppe; Borch, Kim; Westh, Peter; Väljamäe, Priit

2016-12-09

Structural polysaccharides like cellulose and chitin are abundant and their enzymatic degradation to soluble sugars is an important route in green chemistry. Processive glycoside hydrolases (GHs), like cellobiohydrolase Cel7A of Trichoderma reesei (TrCel7A) are key components of efficient enzyme systems. TrCel7A consists of a catalytic domain (CD) and a smaller carbohydrate-binding module (CBM) connected through the glycosylated linker peptide. A tunnel-shaped active site rests in the CD and contains 10 glucose unit binding sites. The active site of TrCel7A is lined with four Trp residues with two of them, Trp-40 and Trp-38, in the substrate binding sites near the tunnel entrance. Although addressed in numerous studies the elucidation of the role of CBM and active site aromatics has been obscured by a complex multistep mechanism of processive GHs. Here we studied the role of the CBM-linker and Trp-38 of TrCel7A with respect to binding affinity, on- and off-rates, processivity, and synergism with endoglucanase. The CBM-linker increased the on-rate and substrate affinity of the enzyme. The Trp-38 to Ala substitution resulted in increased off-rates and decreased processivity. The effect of the Trp-38 to Ala substitution on on-rates was strongly dependent on the presence of the CBM-linker. This compensation between CBM-linker and Trp-38 indicates synergism between CBM-linker and CD in feeding the cellulose chain into the active site. The inter-domain synergism was pre-requisite for the efficient degradation of cellulose in the presence of endoglucanase. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Optimizing Extraction of Cellulose and Synthesizing Pharmaceutical Grade Carboxymethyl Sago Cellulose from Malaysian Sago Pulp

Directory of Open Access Journals (Sweden)

Anand Kumar Veeramachineni

2016-06-01

Full Text Available Sago biomass is an agro-industrial waste produced in large quantities, mainly in the Asia-Pacific region and in particular South-East Asia. This work focuses on using sago biomass to obtain cellulose as the raw material, through chemical processing using acid hydrolysis, alkaline extraction, chlorination and bleaching, finally converting the material to pharmaceutical grade carboxymethyl sago cellulose (CMSC by carboxymethylation. The cellulose was evaluated using Thermogravimetric Analysis (TGA, Infrared Spectroscopy (FTIR, X-Ray Diffraction (XRD, Differential Scanning Calorimetry (DSC and Field Emission Scanning Electronic Microscopy (FESEM. The extracted cellulose was analyzed for cellulose composition, and subsequently modified to CMSC with a degree of substitution (DS 0.6 by typical carboxymethylation reactions. X-ray diffraction analysis indicated that the crystallinity of the sago cellulose was reduced after carboxymethylation. FTIR and NMR studies indicate that the hydroxyl groups of the cellulose fibers were etherified through carboxymethylation to produce CMSC. Further characterization of the cellulose and CMSC were performed using FESEM and DSC. The purity of CMSC was analyzed according to the American Society for Testing and Materials (ASTM International standards. In this case, acid and alkaline treatments coupled with high-pressure defibrillation were found to be effective in depolymerization and defibrillation of the cellulose fibers. The synthesized CMSC also shows no toxicity in the cell line studies and could be exploited as a pharmaceutical excipient.

Induction of mutation in Aspergillus niger for conversion of cellulose into glucose

Energy Technology Data Exchange (ETDEWEB)

Helmi, S.; Khalil, A.E.; Tahoun, M.K.; Khairy, A.H. [Univ. of Alexandria Research Centre, Alexandria (Egypt)

1991-12-31

Plant wastes are very important part of biomass used and investigated for energy, chemical, and fuel production. Cellulose is the major renewable form of carbohydrate in the world, about 10{sup 11} tons of which is synthesized annually. For general use, it must be hydrolyzed first, either chemically or by cellulases derived from a few specialized microorganisms. Enzymes are acceptable environmentally but expensive to produce. Certainly, induction of mutations and selection of high cellulose microbial strains with significant adaptability to degrade cellulose to glucose is promising solutions. Induction of mutations in other fungi and Aspergillus sp. rather than Aspergillus niger was reported. Aspergillus ustus and Trichoderma harzianum were induced by gamma irradiation indicating mutants that excrete higher cellulose yields, particularly exocellobiohydrolase (Avicelase) than their respective wild types. Mutants from the celluiolytic fungus Penicillium pinophilum were induced by chemical and UV-irradiation. Enhancing the production of endo-1,4-{Beta}-D-glucanase (CMCase) and particularly {Beta}-glucosidase was obtained by gamma irradiation of Altemaria alternate. To overcome the lower activity of {beta}-glucosidase in certain fungi species rather than A. niger, mixed cultures of different species were tried. Thus, Aspergillus phonicis with Trichoderma reesei Rut 30, produced a cellulose complex that improved activity twofold over cellulose from Trichoderma alone.

OsCESA9 conserved-site mutation leads to largely enhanced plant lodging resistance and biomass enzymatic saccharification by reducing cellulose DP and crystallinity in rice.

Science.gov (United States)

Li, Fengcheng; Xie, Guosheng; Huang, Jiangfeng; Zhang, Ran; Li, Yu; Zhang, Miaomiao; Wang, Yanting; Li, Ao; Li, Xukai; Xia, Tao; Qu, Chengcheng; Hu, Fan; Ragauskas, Arthur J; Peng, Liangcai

2017-09-01

Genetic modification of plant cell walls has been posed to reduce lignocellulose recalcitrance for enhancing biomass saccharification. Since cellulose synthase (CESA) gene was first identified, several dozen CESA mutants have been reported, but almost all mutants exhibit the defective phenotypes in plant growth and development. In this study, the rice (Oryza sativa) Osfc16 mutant with substitutions (W481C, P482S) at P-CR conserved site in CESA9 shows a slightly affected plant growth and higher biomass yield by 25%-41% compared with wild type (Nipponbare, a japonica variety). Chemical and ultrastructural analyses indicate that Osfc16 has a significantly reduced cellulose crystallinity (CrI) and thinner secondary cell walls compared with wild type. CESA co-IP detection, together with implementations of a proteasome inhibitor (MG132) and two distinct cellulose inhibitors (Calcofluor, CGA), shows that CESA9 mutation could affect integrity of CESA4/7/9 complexes, which may lead to rapid CESA proteasome degradation for low-DP cellulose biosynthesis. These may reduce cellulose CrI, which improves plant lodging resistance, a major and integrated agronomic trait on plant growth and grain production, and enhances biomass enzymatic saccharification by up to 2.3-fold and ethanol productivity by 34%-42%. This study has for the first time reported a direct modification for the low-DP cellulose production that has broad applications in biomass industries. © 2017 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

Structural characterization of a mixed-linkage glucan deficient mutant reveals alteration in cellulose microfibril orientation in rice coleoptile mesophyll cell walls

Directory of Open Access Journals (Sweden)

Andreia Michelle Smith-Moritz

2015-08-01

Full Text Available The CELLULOSE SYNTHASE-LIKE F6 (CslF6 gene was previously shown to mediate the biosynthesis of mixed-linkage glucan (MLG, a cell wall polysaccharide that is hypothesized to be a tightly associated with cellulose and also have a role in cell expansion in the primary cell wall of young seedlings in grass species. We have recently shown that loss-of-function cslf6 rice mutants do not accumulate MLG in most vegetative tissues. Despite the absence of a structurally important polymer, MLG, these mutants are unexpectedly viable and only show a moderate growth compromise compared to wild type. Therefore these mutants are ideal biological systems to test the current grass cell wall model. In order to gain a better understanding of the role of MLG in the primary wall, we performed in-depth compositional and structural analyses of the cell walls of three day-old rice seedlings using various biochemical and novel microspectroscopic approaches. We found that cellulose content as well as matrix polysaccharide composition was not significantly altered in the MLG deficient mutant. However, we observed a significant change in cellulose microfibril bundle organization in mesophyll cell walls of the cslf6 mutant. Using synchrotron source Fourier Transform Mid-Infrared Spectromicroscopy for high-resolution imaging, we determined that the bonds associated with cellulose and arabinoxylan, another major component of the primary cell was of grasses, were in a lower energy configuration compared to wild type, suggesting a slightly weaker primary wall in MLG deficient mesophyll cells. Taken together, these results suggest that MLG may influence cellulose deposition in mesophyll cell walls without significantly affecting anisotropic growth thus challenging MLG importance in cell wall expansion.

Restructuring the crystalline cellulose hydrogen bond network enhances its depolymerization rate

Science.gov (United States)

Shishir P.S. Chundawat; Giovanni Bellesia; Nirmal Uppugundla; Leonardo da Costa Sousa; Dahai Gao; Albert M. Cheh; Umesh P. Agarwal; Christopher M. Bianchetti; George N. Phillips; Paul Langan; Venkatesh Balan; S. Gnanakaran; Bruce E. Dale

2011-01-01

Conversion of lignocellulose to biofuels is partly inefficient due to the deleterious impact of cellulose crystallinity on enzymatic saccharification. We demonstrate how the synergistic activity of cellulases was enhanced by altering the hydrogen bond network within crystalline cellulose fibrils. We provide a molecular-scale explanation of these phenomena through...

Novel Structural and Functional Motifs in cellulose synthase (CesA Genes of Bread Wheat (Triticum aestivum, L..

Directory of Open Access Journals (Sweden)

Simerjeet Kaur

Full Text Available Cellulose is the primary determinant of mechanical strength in plant tissues. Late-season lodging is inversely related to the amount of cellulose in a unit length of the stem. Wheat is the most widely grown of all the crops globally, yet information on its CesA gene family is limited. We have identified 22 CesA genes from bread wheat, which include homoeologs from each of the three genomes, and named them as TaCesAXA, TaCesAXB or TaCesAXD, where X denotes the gene number and the last suffix stands for the respective genome. Sequence analyses of the CESA proteins from wheat and their orthologs from barley, maize, rice, and several dicot species (Arabidopsis, beet, cotton, poplar, potato, rose gum and soybean revealed motifs unique to monocots (Poales or dicots. Novel structural motifs CQIC and SVICEXWFA were identified, which distinguished the CESAs involved in the formation of primary and secondary cell wall (PCW and SCW in all the species. We also identified several new motifs specific to monocots or dicots. The conserved motifs identified in this study possibly play functional roles specific to PCW or SCW formation. The new insights from this study advance our knowledge about the structure, function and evolution of the CesA family in plants in general and wheat in particular. This information will be useful in improving culm strength to reduce lodging or alter wall composition to improve biofuel production.

Diterpene synthases of the biosynthetic system of medicinally active diterpenoids in Marrubium vulgare

DEFF Research Database (Denmark)

Zerbe, Philipp; Chiang, Angela; Dullat, Harpreet

2014-01-01

Marrubium vulgare (Lamiaceae) is a medicinal plant whose major bioactive compounds, marrubiin and other labdane-related furanoid diterpenoids, have potential applications as anti-diabetics, analgesics or vasorelaxants. Metabolite and transcriptome profiling of M. vulgare leaves identified five...... different candidate diterpene synthases (diTPSs) of the TPS-c and TPS-e/f clades. We describe the in vitro and in vivo functional characterization of the M. vulgare diTPS family. In addition to MvEKS ent-kaurene synthase of general metabolism, we identified three diTPSs of specialized metabolism: MvCPS3...

Optimization of upstream and development of cellulose hydrolysis process for cellulosic bio-ethanol production

International Nuclear Information System (INIS)

Bae, Hyeun Jong; Wi, Seung Gon; Lee, Yoon Gyo; Kim, Ho Myung; Kim, Su Bae

2011-10-01

The purpose of this project is optimization of upstream and development of cellulose hydrolysis process for cellulosic bio-ethanol production. The 2nd year Research scope includes: 1) Optimization of pre-treatment conditions for enzymatic hydrolysis of lignocellulosic biomass and 2) Demonstration of enzymatic hydrolysis by recombinant enzymes. To optimize the pretreatment, we applied two processes: a wet process (wet milling + popping), and dry process (popping + dry milling). Out of these, the wet process presented the best glucose yield with a 93.1% conversion, while the dry process yielded 69.6%, and the unpretreated process yielded <20%. The recombinant cellulolytic enzymes showed very high specific activity, about 80-1000 times on CMC and 13-70 times on filter paper at pH 3.5 and 55 .deg. C

Application of a Colorimetric Assay to Identify Putative Ribofuranosylaminobenzene 5'-Phosphate Synthase Genes Expressed with Activity in Escherichia coli

OpenAIRE

Bechard, Matthew E.; Chhatwal, Sonya; Garcia, Rosemarie E.; Rasche, Madeline E.

2003-01-01

Tetrahydromethanopterin (H4MPT) is a tetrahydrofolate analog originally discovered in methanogenic archaea, but later found in other archaea and bacteria. The extent to which H4MPT occurs among living organisms is unknown. The key enzyme which distinguishes the biosynthetic pathways of H4MPT and tetrahydrofolate is ribofuranosylaminobenzene 5'-phosphate synthase (RFAP synthase). Given the importance of RFAP synthase in H4MPT biosynthesis, the identification of putative RFAP synthase genes and...

Cellulase digestibility of pretreated biomass is limited by cellulose accessibility.

Science.gov (United States)

Jeoh, Tina; Ishizawa, Claudia I; Davis, Mark F; Himmel, Michael E; Adney, William S; Johnson, David K

2007-09-01

Attempts to correlate the physical and chemical properties of biomass to its susceptibility to enzyme digestion are often inconclusive or contradictory depending on variables such as the type of substrate, the pretreatment conditions and measurement techniques. In this study, we present a direct method for measuring the key factors governing cellulose digestibility in a biomass sample by directly probing cellulase binding and activity using a purified cellobiohydrolase (Cel7A) from Trichoderma reesei. Fluorescence-labeled T. reesei Cel7A was used to assay pretreated corn stover samples and pure cellulosic substrates to identify barriers to accessibility by this important component of cellulase preparations. The results showed cellulose conversion improved when T. reesei Cel7A bound in higher concentrations, indicating that the enzyme had greater access to the substrate. Factors such as the pretreatment severity, drying after pretreatment, and cellulose crystallinity were found to directly impact enzyme accessibility. This study provides direct evidence to support the notion that the best pretreatment schemes for rendering biomass more digestible to cellobiohydrolase enzymes are those that improve access to the cellulose in biomass cell walls, as well as those able to reduce the crystallinity of cell wall cellulose.

The structural and functional contributions of β-glucosidase-producing microbial communities to cellulose degradation in composting.

Science.gov (United States)

Zang, Xiangyun; Liu, Meiting; Fan, Yihong; Xu, Jie; Xu, Xiuhong; Li, Hongtao

2018-01-01

Compost habitats sustain a vast ensemble of microbes that engender the degradation of cellulose, which is an important part of global carbon cycle. β-Glucosidase is the rate-limiting enzyme of degradation of cellulose. Thus, analysis of regulation of β-glucosidase gene expression in composting is beneficial to a better understanding of cellulose degradation mechanism. Genetic diversity and expression of β-glucosidase-producing microbial communities, and relationships of cellulose degradation, metabolic products and the relative enzyme activity during natural composting and inoculated composting were evaluated. Compared with natural composting, adding inoculation agent effectively improved the degradation of cellulose, and maintained high level of the carboxymethyl cellulose (CMCase) and β-glucosidase activities in thermophilic phase. Gene expression analysis showed that glycoside hydrolase family 1 (GH1) family of β-glucosidase genes contributed more to β-glucosidase activity in the later thermophilic phase in inoculated compost. In the cooling phase of natural compost, glycoside hydrolase family 3 (GH3) family of β-glucosidase genes contributed more to β-glucosidase activity. Intracellular β-glucosidase activity played a crucial role in the regulation of β-glucosidase gene expression, and upregulation or downregulation was also determined by extracellular concentration of glucose. At sufficiently high glucose concentrations, the functional microbial community in compost was altered, which may contribute to maintaining β-glucosidase activity despite the high glucose content. This research provides an ecological functional map of microorganisms involved in carbon metabolism in cattle manure-rice straw composting. The performance of the functional microbial groups in the two composting treatments is different, which is related to the cellulase activity and cellulose degradation, respectively.

Regiocontroll synthesis cellulose-graft-polycaprolactone copolymer (2,3-di-O-PCL-cellulose by a new route

Directory of Open Access Journals (Sweden)

K. L. Wang

2017-12-01

Full Text Available A new and convenient route to the regiocontrolled synthesis of a cellulose-based derivate copolymer (2,3-di-O-polycaprolactone-cellulose grafting ε-caprolactone (ε-CL from α-cellulose, cellulose-graft-polycaprolactone (cellulose-g-PCL, by a classical ring-opening polymerization (ROP reaction, using stannous octoate (Sn(Oct2 as catalyst, in 68% concentration of zinc chloride aqueous solution at 120 °C was presented. By controlling the hydroxyl of cellulose/ε-CL, catalyst/monomer ratio and the reaction time, the molecular architecture of the copolymers can be altered. The solubility of cellulose in zinc chloride aqueous was indicated by UV/VIS spectrometer and rheological measurements. The structures and thermal properties of cellulose-g-polycaprolactone copolymers were characterized using Fourier Transform Infrared (FT-IR, Proton Nuclear Magnetic Resonance Spectroscopy (1H NMR, X-ray Diffraction (XRD, Thermogravimetric Analysis (TGA, Differential Scanning Calorimetry (DSC and Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES. The interesting results confirm that zinc chloride solution can break the intra-molecular hydrogen bonds of cellulose selectively (not only O3H···O5, but also O2H···O6, and has no effect on the inter-molecular hydrogen bonds (O6H···O3. And the grafting reactivity of hydroxyl on cellulose is C2–OH > C3–OH >> C6–OH in zinc chloride solution, and this is clearly different from other researches. Most importantly, this work confirms that the method to regiocontrolled synthesis cellulose-based derivative polymers by regiobreaking hydrogen bonds is feasible. It is strongly believed that the new discovery may give a novel, environmental, simple and inexpensive method to modify cellulose chemically with various side chains grafted on a given hydroxyl, through liberating hydroxyl as reactive group from hydrogen bonds broken selectively by different solvents.

High Dehumidification Performance of Amorphous Cellulose Composite Membranes prepared from Trimethylsilyl Cellulose

KAUST Repository

Puspasari, Tiara; Akhtar, Faheem Hassan; Ogieglo, Wojciech; Alharbi, Ohoud; Peinemann, Klaus-Viktor

2018-01-01

Cellulose is widely regarded as an environmentally friendly, natural and low cost material which can significantly contribute the sustainable economic growth. In this study, cellulose composite membranes were prepared via regeneration

Altered expression of the caffeine synthase gene in a naturally caffeine-free mutant of Coffea arabica

Directory of Open Access Journals (Sweden)

Mirian Perez Maluf

2009-01-01

Full Text Available In this work, we studied the biosynthesis of caffeine by examining the expression of genes involved in this biosynthetic pathway in coffee fruits containing normal or low levels of this substance. The amplification of gene-specific transcripts during fruit development revealed that low-caffeine fruits had a lower expression of the theobromine synthase and caffeine synthase genes and also contained an extra transcript of the caffeine synthase gene. This extra transcript contained only part of exon 1 and all of exon 3. The sequence of the mutant caffeine synthase gene revealed the substitution of isoleucine for valine in the enzyme active site that probably interfered with enzymatic activity. These findings indicate that the absence of caffeine in these mutants probably resulted from a combination of transcriptional regulation and the presence of mutations in the caffeine synthase amino acid sequence.

Preparation of cellulose II and IIII films by allomorphic conversion of bacterial cellulose I pellicles

International Nuclear Information System (INIS)

Faria-Tischer, Paula C.S.; Tischer, Cesar A.; Heux, Laurent; Le Denmat, Simon; Picart, Catherine; Sierakowski, Maria-R.

2015-01-01

The structural changes resulting from the conversion of native cellulose I (Cel I) into allomorphs II (Cel II) and III I (Cel III I ) have usually been studied using powder samples from plant or algal cellulose. In this work, the conversion of Cel I into Cel II and Cel III I was performed on bacterial cellulose films without any mechanical disruption. The surface texture of the films was observed by atomic force microscopy (AFM) and the morphology of the constituting cellulose ribbons, by transmission electron microscopy (TEM). The structural changes were characterized using solid-state NMR spectroscopy as well as X-ray and electron diffraction. The allomorphic change into Cel II and Cel III I resulted in films with different crystallinity, roughness and hydrophobic/hydrophilicity surface and the films remained intact during all process of allomorphic conversion. - Highlights: • Description of a method to modify the allomorphic structure of bacterial cellulose films • Preparation of films with specific morphologies and hydrophobic/hydrophilic surface characters • First report on cellulose III films from bacterial cellulose under swelling conditions • Detailed characterization of cellulose II and III films with complementary techniques • Development of films with specific properties as potential support for cells, enzymes, and drugs

Cellulose nanocrystal properties and their applications

Directory of Open Access Journals (Sweden)

mahdi jonoobi

2015-05-01

Full Text Available The main purpose of this work is to provide an overview of recent research in the area of cellulose nonmaterials production from different sources. Due to their abundance, their renewability, high strength and stiffness, being eco-friendly, and low weight; numerous studies have been reported on the isolation of cellulose nanomaterials from different cellulosic sources and their use in high performance applications. This work covers an introduction into the nano cellulose definition as well as used methods for isolation of nanomaterials (nanocrystals from various sources. The rod-like cellulose nanocrystals (CNC can be isolated from sources like wood, plant fibers, agriculture and industrial bio residues, tunicates, and bacterial cellulose using acid hydrolysis process. Following this, the paper focused on characterization methods, materials properties and structure. The current review is a comprehensive literature regarding the nano cellulose isolation and demonstrates the potential of cellulose nanomaterials to be used in a wide range of high-tech applications.

fA cellular automaton model of crystalline cellulose hydrolysis by cellulases

Directory of Open Access Journals (Sweden)

Little Bryce A

2011-10-01

Full Text Available Abstract Background Cellulose from plant biomass is an abundant, renewable material which could be a major feedstock for low emissions transport fuels such as cellulosic ethanol. Cellulase enzymes that break down cellulose into fermentable sugars are composed of different types - cellobiohydrolases I and II, endoglucanase and β-glucosidase - with separate functions. They form a complex interacting network between themselves, soluble hydrolysis product molecules, solution and solid phase substrates and inhibitors. There have been many models proposed for enzymatic saccharification however none have yet employed a cellular automaton approach, which allows important phenomena, such as enzyme crowding on the surface of solid substrates, denaturation and substrate inhibition, to be considered in the model. Results The Cellulase 4D model was developed de novo taking into account the size and composition of the substrate and surface-acting enzymes were ascribed behaviors based on their movements, catalytic activities and rates, affinity for, and potential for crowding of, the cellulose surface, substrates and inhibitors, and denaturation rates. A basic case modeled on literature-derived parameters obtained from Trichoderma reesei cellulases resulted in cellulose hydrolysis curves that closely matched curves obtained from published experimental data. Scenarios were tested in the model, which included variation of enzyme loadings, adsorption strengths of surface acting enzymes and reaction periods, and the effect on saccharide production over time was assessed. The model simulations indicated an optimal enzyme loading of between 0.5 and 2 of the base case concentrations where a balance was obtained between enzyme crowding on the cellulose crystal, and that the affinities of enzymes for the cellulose surface had a large effect on cellulose hydrolysis. In addition, improvements to the cellobiohydrolase I activity period substantially improved overall

Glucose production for cellulose

Energy Technology Data Exchange (ETDEWEB)

Suzuki, S; Karube, I

1977-04-16

Glucose was produced from cellulose by passing a cellulose solution through a column of an immobilized cellulase which was prepared by coating an inorganic carrier such as macadam or stainless steel beads with collagen containing the cellulase. Thus, 4 mL of 5% cellulase T-AP (60,000 units/g) solution was dissolved in 100 g of 0.9% collagen solution and the solution mixed with 60 g of macadam (diam. = 0.5 to 1.5 mm) and stirred for 10 min. The treated beads were dried in air at 10/sup 0/ to yield an immobilized enzyme retaining 64% of its activity. Through a column (0.8 x 20 cm) packed with 3 g of the immobilized enzyme, 100 mL of 0.33% Avicel SF solution was circulated at 26.4 mL/min at 30/sup 0/ for 60 h. The Avicel SF conversion to glucose was 23%.

Identification of a Fungal 1,8-Cineole Synthase from Hypoxylon sp. with Specificity Determinants in Common with the Plant Synthases*

Science.gov (United States)

Shaw, Jeffrey J.; Berbasova, Tetyana; Sasaki, Tomoaki; Jefferson-George, Kyra; Spakowicz, Daniel J.; Dunican, Brian F.; Portero, Carolina E.; Narváez-Trujillo, Alexandra; Strobel, Scott A.

2015-01-01

Terpenes are an important and diverse class of secondary metabolites widely produced by fungi. Volatile compound screening of a fungal endophyte collection revealed a number of isolates in the family Xylariaceae, producing a series of terpene molecules, including 1,8-cineole. This compound is a commercially important component of eucalyptus oil used in pharmaceutical applications and has been explored as a potential biofuel additive. The genes that produce terpene molecules, such as 1,8-cineole, have been little explored in fungi, providing an opportunity to explore the biosynthetic origin of these compounds. Through genome sequencing of cineole-producing isolate E7406B, we were able to identify 11 new terpene synthase genes. Expressing a subset of these genes in Escherichia coli allowed identification of the hyp3 gene, responsible for 1,8-cineole biosynthesis, the first monoterpene synthase discovered in fungi. In a striking example of convergent evolution, mutational analysis of this terpene synthase revealed an active site asparagine critical for water capture and specificity during cineole synthesis, the same mechanism used in an unrelated plant homologue. These studies have provided insight into the evolutionary relationship of fungal terpene synthases to those in plants and bacteria and further established fungi as a relatively untapped source of this important and diverse class of compounds. PMID:25648891

Polymorphy in native cellulose: recent developments

International Nuclear Information System (INIS)

Atalla, R.H.

1984-01-01

In a number of earlier studies, the authors developed a model of cellulose structure based on the existence of two stable, linearly ordered conformations of the cellulose chain that are dominant in celluloses I and II, respectively. The model rests on extensive Raman spectral observations together with conformational considerations and solid-state 13 C-NMR studies. More recently, they have proposed, on the basis of high resolution solid-state 13 C-NMR observations, that native celluloses are composites of two distinct crystalline forms that coexist in different proportions in all native celluloses. In the present work, they examine the Raman spectra of the native celluloses, and reconcile their view of conformational differences with the new level of crystalline polymorphy of native celluloses revealed in the solid-state 13 C-NMR investigations

Cellulase and Xylanase Production by Penicillium echinulatum in Submerged Media Containing Cellulose Amended with Sorbitol

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Carla Eliana Todero Ritter

2013-01-01

Full Text Available The present work investigated the use of sorbitol as a soluble carbon source, in association with cellulose, to produce cellulases and xylanases in submerged cultures of Penicillium echinulatum 9A02S1. Because cellulose is an insoluble carbon source, in cellulase production, there are some problems with rheology and oxygen transfer. The submerged fermentations containing media composed of 0, 0.25, 0.5, 0.75, and 1% (w/v sorbitol and cellulose that were added at different times during the cultivation; 0.2% (w/v soy bran; 0.1% (w/v wheat bran; and a solution of salts. The highest filter paper activity (FPA ( IU·mL−1 was obtained on the seventh day in the medium containing 0.5% (w/v sorbitol and 0.5% (w/v cellulose added 24 h after the start of cultivation. However, the CMCases showed an activity peak on the sixth day ( IU·mL−1 in the medium containing 0.75% (w/v sorbitol and 0.75% (w/v cellulose added after 12 h of cultivation. The xylanases showed the highest activity in the medium with 0.75% (w/v sorbitol and 0.25% (w/v cellulose added 36 h after the start of cultivation. This strategy enables the reduction of the cellulose concentration, which in high concentrations can cause rheological and oxygen transfer problems.

Biochemistry of cellulose degradation and cellulose utilization for feeds and for protein

Energy Technology Data Exchange (ETDEWEB)

Sadara, J C; Lachke, A H; Shewale, J G

1979-01-01

A review discussing production of single-cell protein, fuel, and glucose from cellulose decomposition; surface or solid fermentations of single-cell protein; production of cellulases; and the biochemistry of cellulose degradation was presented.

Electrospinning cellulose based nanofibers for sensor applications

Science.gov (United States)

Nartker, Steven

2009-12-01

Bacterial pathogens have recently become a serious threat to the food and water supply. A biosensor based on an electrochemical immunoassay has been developed for detecting food borne pathogens, such as Escherichia coli (E. coli) O157:H7. These sensors consist of several materials including, cellulose, cellulose nitrate, polyaniline and glass fibers. The current sensors have not been optimized in terms of microscale architecture and materials. The major problem associated with the current sensors is the limited concentration range of pathogens that provides a linear response on the concentration conductivity chart. Electrospinning is a process that can be used to create a patterned fiber mat design that will increase the linear range and lower the detection limit of these sensors by improving the microscale architecture. Using the electrospinning process to produce novel mats of cellulose nitrate will offer improved surface area, and the cellulose nitrate can be treated to further improve chemical interactions required for sensor activity. The macro and micro architecture of the sensor is critical to the performance of the sensors. Electrospinning technology can be used to create patterned architectures of nanofibers that will enhance sensor performance. To date electrospinning of cellulose nitrate has not been performed and optimization of the electrospinning process will provide novel materials suitable for applications such as filtration and sensing. The goal of this research is to identify and elucidate the primary materials and process factors necessary to produce cellulose nitrate nanofibers using the electrospinning process that will improve the performance of biosensors. Cellulose nitrate is readily dissolved in common organic solvents such as acetone, tetrahydrofuran (THF) and N,N dimethylformamide (DMF). These solvents can be mixed with other latent solvents such as ethanol and other alcohols to provide a solvent system with good electrospinning behavior

Enzymatic cellulose oxidation is linked to lignin by long-range electron transfer

DEFF Research Database (Denmark)

Westereng, Bjorge; Cannella, David; Wittrup Agger, Jane

2015-01-01

cell walls. Electron transfer was confirmed by electron paramagnetic resonance spectroscopy showing that LPMO activity on cellulose changes the level of unpaired electrons in the lignin. The discovery of a long-range electron transfer mechanism links the biodegradation of cellulose and lignin and sheds...

The molecular motor F-ATP synthase is targeted by the tumoricidal protein HAMLET.

Science.gov (United States)

Ho, James; Sielaff, Hendrik; Nadeem, Aftab; Svanborg, Catharina; Grüber, Gerhard

2015-05-22

HAMLET (human alpha-lactalbumin made lethal to tumor cells) interacts with multiple tumor cell compartments, affecting cell morphology, metabolism, proteasome function, chromatin structure and viability. This study investigated if these diverse effects of HAMLET might be caused, in part, by a direct effect on the ATP synthase and a resulting reduction in cellular ATP levels. A dose-dependent reduction in cellular ATP levels was detected in A549 lung carcinoma cells, and by confocal microscopy, co-localization of HAMLET with the nucleotide-binding subunits α (non-catalytic) and β (catalytic) of the energy converting F1F0 ATP synthase was detected. As shown by fluorescence correlation spectroscopy, HAMLET binds to the F1 domain of the F1F0 ATP synthase with a dissociation constant (KD) of 20.5μM. Increasing concentrations of the tumoricidal protein HAMLET added to the enzymatically active α3β3γ complex of the F-ATP synthase lowered its ATPase activity, demonstrating that HAMLET binding to the F-ATP synthase effects the catalysis of this molecular motor. Single-molecule analysis was applied to study HAMLET-α3β3γ complex interaction. Whereas the α3β3γ complex of the F-ATP synthase rotated in a counterclockwise direction with a mean rotational rate of 3.8±0.7s(-1), no rotation could be observed in the presence of bound HAMLET. Our findings suggest that direct effects of HAMLET on the F-ATP synthase may inhibit ATP-dependent cellular processes. Copyright © 2015 Elsevier Ltd. All rights reserved.

All-cellulose composites of regenerated cellulose fibres by surface selective dissolution

NARCIS (Netherlands)

Soykeabkaew, N.; Nishino, T.; Peijs, Ton

2009-01-01

All-cellulose composites of Lyocell and high modulus/strength cellulose fibres were successfully prepared using a surface selective dissolution method. The effect of immersion time of the fibres in the solvent during composite's preparation and the effect of the starting fibre's structure on their

Synthesis, characterization and antibacterial activity of biodegradable starch/PVA composite films reinforced with cellulosic fibre.

Science.gov (United States)

Priya, Bhanu; Gupta, Vinod Kumar; Pathania, Deepak; Singha, Amar Singh

2014-08-30

Cellulosic fibres reinforced composite blend films of starch/poly(vinyl alcohol) (PVA) were prepared by using citric acid as plasticizer and glutaraldehyde as the cross-linker. The mechanical properties of cellulosic fibres reinforced composite blend were compared with starch/PVA crossed linked blend films. The increase in the tensile strength, elongation percentage, degree of swelling and biodegradability of blend films was evaluated as compared to starch/PVA crosslinked blend films. The value of different evaluated parameters such as citric acid, glutaraldehyde and reinforced fibre to starch/PVA (5:5) was found to be 25 wt.%, 0.100 wt.% and 20 wt.%, respectively. The blend films were characterized using Fourier transform-infrared spectrophotometry (FTIR), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA/DTA/DTG). Scanning electron microscopy illustrated a good adhesion between starch/PVA blend and fibres. The blend films were also explored for antimicrobial activities against pathogenic bacteria like Staphylococcus aureus and Escherichia coli. The results confirmed that the blended films may be used as exceptional material for food packaging. Copyright © 2014 Elsevier Ltd. All rights reserved.

Biochemical identification of residues that discriminate between 3,4-dihydroxyphenylalanine decarboxylase and 3,4-dihydroxyphenylacetaldehyde synthase-mediated reactions.

Science.gov (United States)

Liang, Jing; Han, Qian; Ding, Haizhen; Li, Jianyong

2017-12-01

In available insect genomes, there are several L-3,4-dihydroxyphenylalanine (L-dopa) decarboxylase (DDC)-like or aromatic amino acid decarboxylase (AAAD) sequences. This contrasts to those of mammals whose genomes contain only one DDC. Our previous experiments established that two DDC-like proteins from Drosophila actually mediate a complicated decarboxylation-oxidative deamination process of dopa in the presence of oxygen, leading to the formation of 3,4-dihydroxyphenylacetaldehyde (DHPA), CO 2 , NH 3, and H 2 O 2 . This contrasts to the typical DDC-catalyzed reaction, which produces CO 2 and dopamine. These DDC-like proteins were arbitrarily named DHPA synthases based on their critical role in insect soft cuticle formation. Establishment of reactions catalyzed by these AAAD-like proteins solved a puzzle that perplexed researchers for years, but to tell a true DHPA synthase from a DDC in the insect AAAD family remains problematic due to high sequence similarity. In this study, we performed extensive structural and biochemical comparisons between DHPA synthase and DDC. These comparisons identified several target residues potentially dictating DDC-catalyzed and DHPA synthase-catalyzed reactions, respectively. Comparison of DHPA synthase homology models with crystal structures of typical DDC proteins, particularly residues in the active sites, provided further insights for the roles these identified target residues play. Subsequent site-directed mutagenesis of the tentative target residues and activity evaluations of their corresponding mutants determined that active site His192 and Asn192 are essential signature residues for DDC- and DHPA synthase-catalyzed reactions, respectively. Oxygen is required in DHPA synthase-mediated process and this oxidizing agent is reduced to H 2 O 2 in the process. Biochemical assessment established that H 2 O 2 , formed in DHPA synthase-mediated process, can be reused as oxidizing agent and this active oxygen species is reduced to H 2

Homospermidine synthase, the first pathway-specific enzyme of pyrrolizidine alkaloid biosynthesis, evolved from deoxyhypusine synthase

Science.gov (United States)

Ober, Dietrich; Hartmann, Thomas

1999-01-01

Pyrrolizidine alkaloids are preformed plant defense compounds with sporadic phylogenetic distribution. They are thought to have evolved in response to the selective pressure of herbivory. The first pathway-specific intermediate of these alkaloids is the rare polyamine homospermidine, which is synthesized by homospermidine synthase (HSS). The HSS gene from Senecio vernalis was cloned and shown to be derived from the deoxyhypusine synthase (DHS) gene, which is highly conserved among all eukaryotes and archaebacteria. DHS catalyzes the first step in the activation of translation initiation factor 5A (eIF5A), which is essential for eukaryotic cell proliferation and which acts as a cofactor of the HIV-1 Rev regulatory protein. Sequence comparison provides direct evidence for the evolutionary recruitment of an essential gene of primary metabolism (DHS) for the origin of the committing step (HSS) in the biosynthesis of pyrrolizidine alkaloids. PMID:10611289

Magnetically modified bacterial cellulose: A promising carrier for immobilization of affinity ligands, enzymes, and cells

Energy Technology Data Exchange (ETDEWEB)

Baldikova, Eva [Global Change Research Institute, CAS, Na Sadkach 7, 370 05 Ceske Budejovice (Czech Republic); Pospiskova, Kristyna [Regional Centre of Advanced Technologies and Materials, Palacky University, Slechtitelu 27, 783 71 Olomouc (Czech Republic); Ladakis, Dimitrios; Kookos, Ioannis K. [Department of Chemical Engineering, University of Patras, 26504 Patras, Rio (Greece); Koutinas, Apostolis A. [Department of Food Science and Human Nutrition, Agricultural University of Athens, Iera Odos 75, Athens 11855 (Greece); Safarikova, Mirka [Global Change Research Institute, CAS, Na Sadkach 7, 370 05 Ceske Budejovice (Czech Republic); Department of Nanobiotechnology, Biology Centre, ISB, CAS, Na Sadkach 7, 370 05 Ceske Budejovice (Czech Republic); Safarik, Ivo, E-mail: safarik@nh.cas.cz [Global Change Research Institute, CAS, Na Sadkach 7, 370 05 Ceske Budejovice (Czech Republic); Regional Centre of Advanced Technologies and Materials, Palacky University, Slechtitelu 27, 783 71 Olomouc (Czech Republic); Department of Nanobiotechnology, Biology Centre, ISB, CAS, Na Sadkach 7, 370 05 Ceske Budejovice (Czech Republic)

2017-02-01

Bacterial cellulose (BC) produced by Komagataeibacter sucrofermentans was magnetically modified using perchloric acid stabilized magnetic fluid. Magnetic bacterial cellulose (MBC) was used as a carrier for the immobilization of affinity ligands, enzymes and cells. MBC with immobilized reactive copper phthalocyanine dye was an efficient adsorbent for crystal violet removal; the maximum adsorption capacity was 388 mg/g. Kinetic and thermodynamic parameters were also determined. Model biocatalysts, namely bovine pancreas trypsin and Saccharomyces cerevisiae cells were immobilized on MBC using several strategies including adsorption with subsequent cross-linking with glutaraldehyde and covalent binding on previously activated MBC using sodium periodate or 1,4-butanediol diglycidyl ether. Immobilized yeast cells retained approximately 90% of their initial activity after 6 repeated cycles of sucrose solution hydrolysis. Trypsin covalently bound after MBC periodate activation was very stable during operational stability testing; it could be repeatedly used for ten cycles of low molecular weight substrate hydrolysis without loss of its initial activity. - Highlights: • Bacterial cellulose was magnetically modified with magnetic fluid. • Magnetic cellulose is an efficient carrier for affinity ligands. • Enzymes and cells can be efficiently immobilized to magnetic cellulose.

Preparation and characterization of transparent PMMA-cellulose-based nanocomposites.

Science.gov (United States)

Kiziltas, Esra Erbas; Kiziltas, Alper; Bollin, Shannon C; Gardner, Douglas J

2015-01-01

Nanocomposites of polymethylmethacrylate (PMMA) and cellulose were made by a solution casting method using acetone as the solvent. The nanofiber networks were prepared using three different types of cellulose nanofibers: (i) nanofibrillated cellulose (NFC), (ii) cellulose nanocrystals (CNC) and (iii) bacterial cellulose from nata de coca (NDC). The loading of cellulose nanofibrils in the PMMA varied between 0.25 and 0.5 wt%. The mechanical properties of the composites were evaluated using a dynamic mechanical thermal analyzer (DMTA). The flexural modulus of the nanocomposites reinforced with NDC at the 0.5 wt% loading level increased 23% compared to that of pure PMMA. The NFC composite also exhibited a slightly increased flexural strength around 60 MPa while PMMA had a flexural strength of 57 MPa. The addition of NDC increased the storage modulus (11%) compared to neat PMMA at room temperature while the storage modulus of PPMA/CNC nanocomposite containing 0.25 and 0.5 wt% cellulose increased about 46% and 260% to that of the pure PMMA at the glass transition temperature, respectively. Thermogravimetric analysis (TGA) indicated that there was no significant change in thermal stability of the composites. The UV-vis transmittance of the CNF nanocomposites decreased by 9% and 27% with the addition of 0.25 wt% CNC and NDC, respectively. This work is intended to spur research and development activity for application of CNF reinforced PMMA nanocomposites in applications such as: packaging, flexible screens, optically transparent films and light-weight transparent materials for ballistic protection. Copyright © 2015 Elsevier Ltd. All rights reserved.

Volatile constituents of Dianthus rupicola Biv. from Sicily: activity against microorganisms affecting cellulosic objects.

Science.gov (United States)

Casiglia, Simona; Bruno, Maurizio; Senatore, Felice

2014-01-01

Dianthus rupicola Biv. (cliffs carnation) is a camephytic, suffruticous, perennial plant growing up to 40 cm high. The plant is widespread in Sicily and neighbouring islands (Egadi, Lampedusa, Lipari) and in some areas of southern Italy. GC and GC-MS analyses of the essential oil distilled from the flowers showed the presence of 66 components. Its composition is characterised by the high content of thymol and carvacrol derivatives. A good antibacterial activity against Bacillus cereus and Bacillussubtilis, both infesting cellulosic historical material, was shown, whereas the antioxidant capacity was determined to be quite poor.

Strong and Optically Transparent Films Prepared Using Cellulosic Solid Residue Recovered from Cellulose Nanocrystals Production Waste Stream

Science.gov (United States)

Qianqian Wang; J.Y. Zhu; John M. Considine

2013-01-01

We used a new cellulosic material, cellulosic solid residue (CSR), to produce cellulose nanofibrils (CNF) for potential high value applications. Cellulose nanofibrils (CNF) were produced from CSR recovered from the hydrolysates (waste stream) of acid hydrolysis of a bleached Eucalyptus kraft pulp (BEP) to produce nanocrystals (CNC). Acid hydrolysis greatly facilitated...

Human METTL12 is a mitochondrial methyltransferase that modifies citrate synthase.

Science.gov (United States)

Rhein, Virginie F; Carroll, Joe; Ding, Shujing; Fearnley, Ian M; Walker, John E

2017-06-01

The protein methylome in mammalian mitochondria has been little studied until recently. Here, we describe that lysine-368 of human citrate synthase is methylated and that the modifying enzyme, localized in the mitochondrial matrix, is methyltransferase-like protein 12 (METTL12), a member of the family of 7β-strand methyltransferases. Lysine-368 is near the active site of citrate synthase, but removal of methylation has no effect on its activity. In mitochondria, it is possible that some or all of the enzymes of the citric acid cycle, including citrate synthase, are organized in metabolons to facilitate the channelling of substrates between participating enzymes. Thus, possible roles for the methylation of Lys-368 are in controlling substrate channelling itself, or in influencing protein-protein interactions in the metabolon. © 2017 The Authors FEBS Letters published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies.

21 CFR 573.420 - Ethyl cellulose.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ethyl cellulose. 573.420 Section 573.420 Food and... Listing § 573.420 Ethyl cellulose. The food additive ethyl cellulose may be safely used in animal feed in accordance with the following prescribed conditions: (a) The food additive is a cellulose ether containing...

21 CFR 172.868 - Ethyl cellulose.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethyl cellulose. 172.868 Section 172.868 Food and... Multipurpose Additives § 172.868 Ethyl cellulose. The food additive ethyl cellulose may be safely used in food in accordance with the following prescribed conditions: (a) The food additive is a cellulose ether...

Isolation and Characterization of Three New Monoterpene Synthases from Artemisia annua

Science.gov (United States)

Ruan, Ju-Xin; Li, Jian-Xu; Fang, Xin; Wang, Ling-Jian; Hu, Wen-Li; Chen, Xiao-Ya; Yang, Chang-Qing

2016-01-01

Artemisia annua, an annual herb used in traditional Chinese medicine, produces a wealth of monoterpenes and sesquiterpenes, including the well-known sesquiterpene lactone artemisinin, an active ingredient in the treatment for malaria. Here we report three new monoterpene synthases of A. annua. From a glandular trichome cDNA library, monoterpene synthases of AaTPS2, AaTPS5, and AaTPS6, were isolated and characterized. The recombinant proteins of AaTPS5 and AaTPS6 produced multiple products with camphene and 1,8-cineole as major products, respectively, and AaTPS2 produced a single product, β-myrcene. Although both Mg2+ and Mn2+ were able to support their catalytic activities, altered product spectrum was observed in the presence of Mn2+ for AaTPS2 and AaTPS5. Analysis of extracts of aerial tissues and root of A. annua with gas chromatography–mass spectrometry detected more than 20 monoterpenes, of which the three enzymes constituted more than 1/3 of the total. Mechanical wounding induced the expression of all three monoterpene synthase genes, and transcript levels of AaTPS5 and AaTPS6 were also elevated after treatments with phytohormones of methyl jasmonate, salicylic acid, and gibberellin, suggesting a role of these monoterpene synthases in plant–environment interactions. The three new monoterpene synthases reported here further our understanding of molecular basis of monoterpene biosynthesis and regulation in plant. PMID:27242840

Isolation and characterization of three new monoterpene synthases from Artemisia annua

Directory of Open Access Journals (Sweden)

Ju-Xin eRuan

2016-05-01

Full Text Available Artemisia annua, an annual herb used in traditional Chinese medicine, produces a wealth of monoterpenes and sesquiterpenes, including the well-known sesquiterpene lactone artemisinin, an active ingredient in the treatment for malaria. Here we report three new monoterpene synthases of A. annua. From a glandular trichome cDNA library, monoterpene synthases of AaTPS2, AaTPS5 and AaTPS6, were isolated and characterized. The recombinant proteins of AaTPS5 and AaTPS6 produced multiple products with camphene and 1,8-cineole as major products, respectively, and AaTPS2 produced a single product, β-myrcene. Although both Mg2+ and Mn2+ were able to support their catalytic activities, altered product spectrum was observed in the presence of Mn2+ for AaTPS2 and AaTPS5. Analysis of extracts of aerial tissues and root of A. annua with gas chromatography-mass spectrometry (GC-MS detected more than 20 monoterpenes, of which the three enzymes constituted more than 1/3 of the total. Mechanical wounding induced the expression of all three monoterpene synthase genes, and transcript levels of AaTPS5 and AaTPS6 were also elevated after treatments with phytohormones of methyl jasmonate (MeJA, salicylic acid (SA and gibberellin (GA, suggesting a role of these monoterpene synthases in plant-environment interactions. The three new monoterpene synthases reported here further our understanding of molecular basis of monoterpene biosynthesis and regulation in plant.

BSA treatment to enhance enzymatic hydrolysis of cellulose in lignin containing substrates.

Science.gov (United States)

Yang, Bin; Wyman, Charles E

2006-07-05

Cellulase and bovine serum albumin (BSA) were added to Avicel cellulose and solids containing 56% cellulose and 28% lignin from dilute sulfuric acid pretreatment of corn stover. Little BSA was adsorbed on Avicel cellulose, while pretreated corn stover solids adsorbed considerable amounts of this protein. On the other hand, cellulase was highly adsorbed on both substrates. Adding a 1% concentration of BSA to dilute acid pretreated corn stover prior to enzyme addition at 15 FPU/g cellulose enhanced filter paper activity in solution by about a factor of 2 and beta-glucosidase activity in solution by about a factor of 14. Overall, these results suggested that BSA treatment reduced adsorption of cellulase and particularly beta-glucosidase on lignin. Of particular note, BSA treatment of pretreated corn stover solids prior to enzymatic hydrolysis increased 72 h glucose yields from about 82% to about 92% at a cellulase loading of 15 FPU/g cellulose or achieved about the same yield at a loading of 7.5 FPU/g cellulose. Similar improvements were also observed for enzymatic hydrolysis of ammonia fiber explosion (AFEX) pretreated corn stover and Douglas fir treated by SO(2) steam explosion and for simultaneous saccharification and fermentation (SSF) of BSA pretreated corn stover. In addition, BSA treatment prior to hydrolysis reduced the need for beta-glucosidase supplementation of SSF. The results are consistent with non-specific competitive, irreversible adsorption of BSA on lignin and identify promising strategies to reduce enzyme requirements for cellulose hydrolysis. (c) 2006 Wiley Periodicals, Inc.

Optimization of upstream and development of cellulose hydrolysis process for cellulosic bio-ethanol production

Energy Technology Data Exchange (ETDEWEB)

Bae, Hyun Jong; Wi, Seung Gon; Kim, Su Bae; Shin, You Jung; Yi, Ju Hui [Chonnam National University, Bio-Energy Research Institute, Gwangju (Korea, Republic of)

2010-10-15

The purpose of this project is optimization of upstream and development of cellulose hydrolysis process for cellulosic bio-ethanol production. Research scope includes 1) screening of various microorganisms from decayed biomass in order to search for more efficient lignocellulose degrading microorganism, 2) identification and verification of new cell wall degrading cellulase for application cellulose bioconversion process, and 3) identification and characterization of novel genes involved in cellulose degradation. To find good microorganism candidates for lignocellulose degrading, 75 decayed samples from different areas were assayed in triplicate and analyzed. For cloning new cell wall degrading enzymes, we selected microorganisms because it have very good lignocellulose degradation ability. From that microorganisms, we have apparently cloned a new cellulase genes (10 genes). We are applying the new cloned cellulase genes to characterize in lignocellulsoe degradation that are most important to cellulosic biofuels production

Optimization of upstream and development of cellulose hydrolysis process for cellulosic bio-ethanol production

International Nuclear Information System (INIS)

Bae, Hyun Jong; Wi, Seung Gon; Kim, Su Bae; Shin, You Jung; Yi, Ju Hui

2010-10-01

The purpose of this project is optimization of upstream and development of cellulose hydrolysis process for cellulosic bio-ethanol production. Research scope includes 1) screening of various microorganisms from decayed biomass in order to search for more efficient lignocellulose degrading microorganism, 2) identification and verification of new cell wall degrading cellulase for application cellulose bioconversion process, and 3) identification and characterization of novel genes involved in cellulose degradation. To find good microorganism candidates for lignocellulose degrading, 75 decayed samples from different areas were assayed in triplicate and analyzed. For cloning new cell wall degrading enzymes, we selected microorganisms because it have very good lignocellulose degradation ability. From that microorganisms, we have apparently cloned a new cellulase genes (10 genes). We are applying the new cloned cellulase genes to characterize in lignocellulsoe degradation that are most important to cellulosic biofuels production

Cellulose-binding domains: tools for innovation in cellulosic fibre production and modification

NARCIS (Netherlands)

Quentin, M.G.E.; Valk, van der H.C.P.M.; Dam, van J.E.G.; Jong, de E.

2003-01-01

Plant cell walls are composed of cellulose, nature's most abundant macromolecule, and therefore represent a renewable resource of special technical importance. Cellulose degrading enzymes involved in plant cell wall loosening (expansins), or produced by plant pathogenic microorganisms (cellulases),

Internally plasticised cellulose polymers

International Nuclear Information System (INIS)

Burnup, M.; Hayes, G.F.; Fydelor, P.J.

1981-01-01

Plasticised cellulose polymers comprise base polymer having a chain of β-anhydroglucose units joined by ether linkages, with at least one of said units carrying at least one chemically unreactive side chain derived from an allylic monomer or a vinyl substituted derivative of ferrocene. The side chains are normally formed by radiation grafting. These internally plasticised celluloses are useful in particular as inhibitor coatings for rocket motor propellants and in general wherever cellulose polymers are employed. (author)

Cellulose Nanomaterials in Water Treatment Technologies

Science.gov (United States)

Carpenter, Alexis Wells; de Lannoy, Charles François; Wiesner, Mark R.

2015-01-01

Cellulose nanomaterials are naturally occurring with unique structural, mechanical and optical properties. While the paper and packaging, automotive, personal care, construction, and textiles industries have recognized cellulose nanomaterials’ potential, we suggest cellulose nanomaterials have great untapped potential in water treatment technologies. In this review, we gather evidence of cellulose nanomaterials’ beneficial role in environmental remediation and membranes for water filtration, including their high surface area-to-volume ratio, low environmental impact, high strength, functionalizability, and sustainability. We make direct comparison between cellulose nanomaterials and carbon nanotubes (CNTs) in terms of physical and chemical properties, production costs, use and disposal in order to show the potential of cellulose nanomaterials as a sustainable replacement for CNTs in water treatment technologies. Finally, we comment on the need for improved communication and collaboration across the myriad industries invested in cellulose nanomaterials production and development to achieve an efficient means to commercialization. PMID:25837659

Cellulose nanomaterials in water treatment technologies.

Science.gov (United States)

Carpenter, Alexis Wells; de Lannoy, Charles-François; Wiesner, Mark R

2015-05-05

Cellulose nanomaterials are naturally occurring with unique structural, mechanical and optical properties. While the paper and packaging, automotive, personal care, construction, and textiles industries have recognized cellulose nanomaterials' potential, we suggest cellulose nanomaterials have great untapped potential in water treatment technologies. In this review, we gather evidence of cellulose nanomaterials' beneficial role in environmental remediation and membranes for water filtration, including their high surface area-to-volume ratio, low environmental impact, high strength, functionalizability, and sustainability. We make direct comparison between cellulose nanomaterials and carbon nanotubes (CNTs) in terms of physical and chemical properties, production costs, use and disposal in order to show the potential of cellulose nanomaterials as a sustainable replacement for CNTs in water treatment technologies. Finally, we comment on the need for improved communication and collaboration across the myriad industries invested in cellulose nanomaterials production and development to achieve an efficient means to commercialization.

Cellulose conversion of corn pericarp without pretreatment.

Science.gov (United States)

Kim, Daehwan; Orrego, David; Ximenes, Eduardo A; Ladisch, Michael R

2017-12-01

We report enzyme hydrolysis of cellulose in unpretreated pericarp at a cellulase loading of 0.25FPU/g pericarp solids using a phenol tolerant Aspergillus niger pectinase preparation. The overall protein added was 5mg/g and gave 98% cellulose conversion in 72h. However, for double the amount of enzyme from Trichoderma reesei, which is significantly less tolerant to phenols, conversion was only 16%. The key to achieving high conversion without pretreatment is combining phenol inhibition-resistant enzymes (such as from A. niger) with unground pericarp from which release of phenols is minimal. Size reduction of the pericarp, which is typically carried out in a corn-to-ethanol process, where corn is first ground to a fine powder, causes release of highly inhibitory phenols that interfere with cellulase enzyme activity. This work demonstrates hydrolysis without pretreatment of large particulate pericarp is a viable pathway for directly producing cellulose ethanol in corn ethanol plants. Copyright © 2017 Elsevier Ltd. All rights reserved.

Posidonia oceanica as a Renewable Lignocellulosic Biomass for the Synthesis of Cellulose Acetate and Glycidyl Methacrylate Grafted Cellulose

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Elena Vismara

2013-05-01

Full Text Available High-grade cellulose (97% α-cellulose content of 48% crystallinity index was extracted from the renewable marine biomass waste Posidonia oceanica using H2O2 and organic peracids following an environmentally friendly and chlorine-free process. This cellulose appeared as a new high-grade cellulose of waste origin quite similar to the high-grade cellulose extracted from more noble starting materials like wood and cotton linters. The benefits of α-cellulose recovery from P. oceanica were enhanced by its transformation into cellulose acetate CA and cellulose derivative GMA-C. Fully acetylated CA was prepared by conventional acetylation method and easily transformed into a transparent film. GMA-C with a molar substitution (MS of 0.72 was produced by quenching Fenton’s reagent (H2O2/FeSO4 generated cellulose radicals with GMA. GMA grafting endowed high-grade cellulose from Posidonia with adsorption capability. GMA-C removes β-naphthol from water with an efficiency of 47%, as measured by UV-Vis spectroscopy. After hydrolysis of the glycidyl group to glycerol group, the modified GMA-C was able to remove p-nitrophenol from water with an efficiency of 92%, as measured by UV-Vis spectroscopy. α-cellulose and GMA-Cs from Posidonia waste can be considered as new materials of potential industrial and environmental interest.

Bifunctional cis-Abienol Synthase from Abies balsamea Discovered by Transcriptome Sequencing and Its Implications for Diterpenoid Fragrance Production*

Science.gov (United States)

Zerbe, Philipp; Chiang, Angela; Yuen, Macaire; Hamberger, Björn; Hamberger, Britta; Draper, Jason A.; Britton, Robert; Bohlmann, Jörg

2012-01-01

The labdanoid diterpene alcohol cis-abienol is a major component of the aromatic oleoresin of balsam fir (Abies balsamea) and serves as a valuable bioproduct material for the fragrance industry. Using high-throughput 454 transcriptome sequencing and metabolite profiling of balsam fir bark tissue, we identified candidate diterpene synthase sequences for full-length cDNA cloning and functional characterization. We discovered a bifunctional class I/II cis-abienol synthase (AbCAS), along with the paralogous levopimaradiene/abietadiene synthase and isopimaradiene synthase, all of which are members of the gymnosperm-specific TPS-d subfamily. The AbCAS-catalyzed formation of cis-abienol proceeds via cyclization and hydroxylation at carbon C-8 of a postulated carbocation intermediate in the class II active site, followed by cleavage of the diphosphate group and termination of the reaction sequence without further cyclization in the class I active site. This reaction mechanism is distinct from that of synthases of the isopimaradiene- or levopimaradiene/abietadiene synthase type, which employ deprotonation reactions in the class II active site and secondary cyclizations in the class I active site, leading to tricyclic diterpenes. Comparative homology modeling suggested the active site residues Asp-348, Leu-617, Phe-696, and Gly-723 as potentially important for the specificity of AbCAS. As a class I/II bifunctional enzyme, AbCAS is a promising target for metabolic engineering of cis-abienol production. PMID:22337889

Sticking to cellulose: exploiting Arabidopsis seed coat mucilage to understand cellulose biosynthesis and cell wall polysaccharide interactions.

Science.gov (United States)

Griffiths, Jonathan S; North, Helen M

2017-05-01

The cell wall defines the shape of cells and ultimately plant architecture. It provides mechanical resistance to osmotic pressure while still being malleable and allowing cells to grow and divide. These properties are determined by the different components of the wall and the interactions between them. The major components of the cell wall are the polysaccharides cellulose, hemicellulose and pectin. Cellulose biosynthesis has been extensively studied in Arabidopsis hypocotyls, and more recently in the mucilage-producing epidermal cells of the seed coat. The latter has emerged as an excellent system to study cellulose biosynthesis and the interactions between cellulose and other cell wall polymers. Here we review some of the major advances in our understanding of cellulose biosynthesis in the seed coat, and how mucilage has aided our understanding of the interactions between cellulose and other cell wall components required for wall cohesion. Recently, 10 genes involved in cellulose or hemicellulose biosynthesis in mucilage have been identified. These discoveries have helped to demonstrate that xylan side-chains on rhamnogalacturonan I act to link this pectin directly to cellulose. We also examine other factors that, either directly or indirectly, influence cellulose organization or crystallization in mucilage. © 2017 INRA. New Phytologist © 2017 New Phytologist Trust.

Reaction kinetics of cellulose hydrolysis in subcritical and supercritical water

Science.gov (United States)

Olanrewaju, Kazeem Bode

converting cellulose to fermentable sugars in subcritical and supercritical water differs because of the difference in their activation energies. Cellulose and starch were both hydrolyzed in micro- and tubular reactors and at subcritical and supercritical conditions. Due to the difficulty involved in generating an aqueous based dissolved cellulose and having it reacted in subcritical water, dissolved starch was used instead. Better yield of water soluble hydrolysates, especially fermentable sugars, were observed from the hydrolysis of cellulose and dissolved starch in subcritical water than at supercritical conditions. The concluding phase of this project focuses on establishing the mode of scission of cellulose chains in the hydrothermal reactor. This was achieved by using the simulated degradation pattern generated based on different scission modes to fingerprint the degradation pattern obtained from experiment.

Cellulose ionics: switching ionic diode responses by surface charge in reconstituted cellulose films.

Science.gov (United States)

Aaronson, Barak D B; Wigmore, David; Johns, Marcus A; Scott, Janet L; Polikarpov, Igor; Marken, Frank

2017-09-25

Cellulose films as well as chitosan-modified cellulose films of approximately 5 μm thickness, reconstituted from ionic liquid media onto a poly(ethylene-terephthalate) (PET, 6 μm thickness) film with a 5, 10, 20, or 40 μm diameter laser-drilled microhole, show significant current rectification in aqueous NaCl. Reconstituted α-cellulose films provide "cationic diodes" (due to predominant cation conductivity) whereas chitosan-doped cellulose shows "anionic diode" effects (due to predominant anion conductivity). The current rectification, or "ionic diode" behaviour, is investigated as a function of NaCl concentration, pH, microhole diameter, and molecular weight of the chitosan dopant. Future applications are envisaged exploiting the surface charge induced switching of diode currents for signal amplification in sensing.

Aspirin inhibits interleukin 1-induced prostaglandin H synthase expression in cultured endothelial cells

International Nuclear Information System (INIS)

Wu, K.K.; Sanduja, R.; Tsai, A.L.; Ferhanoglu, B.; Loose-Mitchell, D.S.

1991-01-01

Prostaglandin H (PGH) synthase is a key enzyme in the biosynthesis of prostaglandins, thromboxane, and prostacyclin. In cultured human umbilical vein endothelial cells, interleukin 1 (IL-1) is known to induce the synthesis of this enzyme, thereby raising the level of PGH synthase protein severalfold over the basal level. Pretreatment with aspirin at low concentrations inhibited more than 60% of the enzyme mass and also the cyclooxygenase activity in IL-1-induced cells with only minimal effects on the basal level of the synthase enzyme in cells without IL-1. Sodium salicylate exhibited a similar inhibitory action whereas indomethacin had no apparent effect. Similarly low levels of aspirin inhibited the increased L-[ 35 S]methionine incorporation into PGH synthase that was induced by IL0-1 and also suppressed expression of the 2.7-kilobase PGH synthase mRNA. These results suggest that in cultured endothelial cells a potent inhibition of eicosanoid biosynthetic capacity can be effected by aspirin or salicylate at the level of PGH synthase gene expression. The aspirin effect may well be due to degradation of salicylate

Inhibition of nitric oxide synthase expression in activated microglia and peroxynitrite scavenging activity by Opuntia ficus indica var. saboten.

Science.gov (United States)

Lee, Ming Hong; Kim, Jae Yeon; Yoon, Jeong Hoon; Lim, Hyo Jin; Kim, Tae Hee; Jin, Changbae; Kwak, Wie-Jong; Han, Chang-Kyun; Ryu, Jae-Ha

2006-09-01

Activated microglia by neuronal injury or inflammatory stimulation overproduce nitric oxide (NO) by inducible nitric oxide synthase (iNOS) and reactive oxygen species (ROS) such as superoxide anion, resulting in neurodegenerative diseases. The toxic peroxynitrite (ONOO-), the reaction product of NO and superoxide anion further contributes to oxidative neurotoxicity. A butanol fraction obtained from 50% ethanol extracts of Opuntia ficus indica var. saboten (Cactaceae) stem (SK OFB901) and its hydrolysis product (SK OFB901H) inhibited the production of NO in LPS-activated microglia in a dose dependent manner (IC50 15.9, 4.2 microg/mL, respectively). They also suppressed the expression of protein and mRNA of iNOS in LPS-activated microglial cells at higher than 30 microg/mL as observed by western blot analysis and RT-PCR experiment. They also inhibited the degradation of I-kappaB-alpha in activated microglia. Moreover, they showed strong activity of peroxynitrite scavenging in a cell free bioassay system. These results imply that Opuntia ficus indica may have neuroprotective activity through the inhibition of NO production by activated microglial cells and peroxynitrite scavenging activity. Copyright (c) 2006 John Wiley & Sons, Ltd.

Raman spectroscopy in the analysis of cellulose nanomaterials

Science.gov (United States)

Umesh P. Agarwal

2017-01-01

Cellulose nanomaterials (CNs) are new types of materials derived from celluloses and offer unique challenges and opportunities for Raman spectroscopic investigations. CNs can be classified into the categories of cellulose nanocrystals (CNCs, also known as cellulose whisker) and cellulose nanofibrils (CNFs, also known as nanofibrillated cellulose or NFCs) which when...

CELLULOSE DEGRADATION BY OXIDATIVE ENZYMES

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Maria Dimarogona

2012-09-01

Full Text Available Enzymatic degradation of plant biomass has attracted intensive research interest for the production of economically viable biofuels. Here we present an overview of the recent findings on biocatalysts implicated in the oxidative cleavage of cellulose, including polysaccharide monooxygenases (PMOs or LPMOs which stands for lytic PMOs, cellobiose dehydrogenases (CDHs and members of carbohydrate-binding module family 33 (CBM33. PMOs, a novel class of enzymes previously termed GH61s, boost the efficiency of common cellulases resulting in increased hydrolysis yields while lowering the protein loading needed. They act on the crystalline part of cellulose by generating oxidized and non-oxidized chain ends. An external electron donor is required for boosting the activity of PMOs. We discuss recent findings concerning their mechanism of action and identify issues and questions to be addressed in the future.

Inhibition of the ATP Synthase Eliminates the Intrinsic Resistance of Staphylococcus aureus towards Polymyxins

DEFF Research Database (Denmark)

Vestergaard, Martin; Nøhr-Meldgaard, Katrine; Bojer, Martin Saxtorph

2017-01-01

, linezolid, daptomycin, and oxacillin were unchanged. ATP synthase activity is known to be inhibited by oligomycin A, and the presence of this compound increased polymyxin B-mediated killing of S. aureus Our results demonstrate that the ATP synthase contributes to intrinsic resistance of S. aureus towards...

Phosphorylation of inhibitor-2 and activation of MgATP-dependent protein phosphatase by rat skeletal muscle glycogen synthase kinase

International Nuclear Information System (INIS)

Hegazy, M.G.; Reimann, E.M.; Thysseril, T.J.; Schlender, K.K.

1986-01-01

Rat skeletal muscle contains a glycogen synthase kinase (GSK-M) which is not stimulated by Ca 2+ or cAMP. This kinase has an apparent Mr of 62,000 and uses ATP but not GTP as a phosphoryl donor. GSK-M phosphorylated glycogen synthase at sites 2 and 3. It phosphorylated ATP-citrate lyase and activated MgATP-dependent phosphatase in the presence of ATP but not GTP. As expected, the kinase also phosphorylated phosphatase inhibitor 2 (I-2). Phosphatase incorporation reached approximately 0.3 mol/mol of I-2. Phosphopeptide maps were obtained by digesting 32 P-labeled I-2 with trypsin and separating the peptides by reversed phase HPLC. Two partially separated 32 P-labeled peaks were obtained when I-2 was phosphorylated with either GSK-M or glycogen synthase kinase 3 (GSK-3) and these peptides were different from those obtained when I-2 was phosphorylated with the catalytic subunit of cAMP-dependent protein kinase (CSU) or casein kinase II (CK-II). When I-2 was phosphorylated with GSK-M or GSK-3 and cleaved by CNBr, a single radioactive peak was obtained. Phosphoamino acid analysis showed that I-2 was phosphorylated by GSK-M or GSK-3 predominately in Thr whereas CSU and CK-II phosphorylated I-2 exclusively in Ser. These results indicate that GSK-M is similar to GSK-3 and to ATP-citrate lyase kinase. However, it appears to differ in Mr from ATP-citrate lyase kinase and it differs from GSK-3 in that it phosphorylates glycogen synthase at site 2 and it does not use GTP as a phosphoryl donor

Extraction of cellulose from pistachio shell and physical and mechanical characterisation of cellulose-based nanocomposites

Science.gov (United States)

Movva, Mounika; Kommineni, Ravindra

2017-04-01

Cellulose is an important nanoentity that have been used for the preparation of composites. The present work focuses on the extraction of cellulose from pistachio shell and preparing a partially degradable nanocomposite with extracted cellulose. Physical and microstructural characteristics of nanocellulose extracted from pistachio shell powder (PSP) through various stages of chemical treatment are identified from scanning electron microscopy (SEM), Fourier transform infra-red spectroscopy (FTIR), x-ray powder diffraction (XRD), and thermogravimetric analysis (TGA). Later, characterized nanocellulose is reinforced in a polyester matrix to fabricate nanocellulose-based composites according to the ASTM standard. The resulting nanocellulose composite performance is evaluated in the mechanical perspective through tensile and flexural loading. SEM, FTIR, and XRD showed that the process for extraction is efficient in obtaining 95% crystalline cellulose. Cellulose also showed good thermal stability with a peak thermal degradation temperature of 361 °C. Such cellulose when reinforced in a matrix material showed a noteworthy rise in tensile and flexural strengths of 43 MPa and 127 MPa, at a definite weight percent of 5%.

Saccharification of cellulose by acetolysis

Energy Technology Data Exchange (ETDEWEB)

Tanaka, T; Yamanaka, S; Takinami, K

1978-01-01

For saccharification of cellulose, an acetolysis method using assimilable acid with a microorganism was applied. Based on this method, a new method which gave totally assimilable products was established. The rigid crystalline structure of cellulose was disrupted by acetolysis with 2-2.5 times as much acetic anhydride as cellulose on a weight basis and 1 N sulfuric acid as a catalyst. Then for cleavage of O-acetyl ester and glycosidic bonds, the resulting amorphous acetolysate of cellulose could easily be hydrolyzed by heating in 1 N sulfuric acid at 120/sup 0/C for 1-1.5 h without over-disruption of glucose. Ninety-eight % of the cellulose used was recovered in the form of hydrolysate having about 30% saccharide concentration. The hydrolysate obtained was composed of 74% glucose, 13% cellobiose and 11% mono-O-acetyl glucose on a weight basis.

Telmisartan activates endothelial nitric oxide synthase via Ser1177 phosphorylation in vascular endothelial cells.

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