Expanding the enzyme universe: accessing non-natural reactions by mechanism-guided directed evolution.

Science.gov (United States)

Renata, Hans; Wang, Z Jane; Arnold, Frances H

2015-03-09

High selectivity and exquisite control over the outcome of reactions entice chemists to use biocatalysts in organic synthesis. However, many useful reactions are not accessible because they are not in nature's known repertoire. In this Review, we outline an evolutionary approach to engineering enzymes to catalyze reactions not found in nature. We begin with examples of how nature has discovered new catalytic functions and how such evolutionary progression has been recapitulated in the laboratory starting from extant enzymes. We then examine non-native enzyme activities that have been exploited for chemical synthesis, with an emphasis on reactions that do not have natural counterparts. Non-natural activities can be improved by directed evolution, thus mimicking the process used by nature to create new catalysts. Finally, we describe the discovery of non-native catalytic functions that may provide future opportunities for the expansion of the enzyme universe. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Expanding the Enzyme Universe: Accessing Non-Natural Reactions by Mechanism-Guided Directed Evolution

Science.gov (United States)

Renata, Hans; Wang, Z. Jane

2015-01-01

High selectivities and exquisite control over reaction outcomes entice chemists to use biocatalysts in organic synthesis. However, many useful reactions are not accessible because they are not in nature’s known repertoire. We will use this review to outline an evolutionary approach to engineering enzymes to catalyze reactions not found in nature. We begin with examples of how nature has discovered new catalytic functions and how such evolutionary progressions have been recapitulated in the laboratory starting from extant enzymes. We then examine non-native enzyme activities that have been discovered and exploited for chemical synthesis, emphasizing reactions that do not have natural counterparts. The new functions have mechanistic parallels to the native reaction mechanisms that often manifest as catalytic promiscuity and the ability to convert from one function to the other with minimal mutation. We present examples of how non-natural activities have been improved by directed evolution, mimicking the process used by nature to create new catalysts. Examples of new enzyme functions include epoxide opening reactions with non-natural nucleophiles catalyzed by a laboratory-evolved halohydrin dehalogenase, cyclopropanation and other carbene transfer reactions catalyzed by cytochrome P450 variants, and non-natural modes of cyclization by a modified terpene synthase. Lastly, we describe discoveries of non-native catalytic functions that may provide future opportunities for expanding the enzyme universe. PMID:25649694

Enzyme activities at different stages of plant biomass decomposition in three species of fungus-growing termites

DEFF Research Database (Denmark)

da Costa, Rafael R.; Hu, Haofu; Pilgaard, Bo

2018-01-01

contributing to the success of the termites as the main plant decomposers in the Old World. Here we evaluate which plant polymers are decomposed and which enzymes are active during the decomposition process in two major genera of fungus-growing termites. We find a diversity of active enzymes at different...... stages of decomposition and a consistent decrease in plant components during the decomposition process. Furthermore, our findings are consistent with the hypothesis that termites transport enzymes from the older mature parts of the fungus comb through young worker guts to freshly inoculated plant...... substrate. However, preliminary fungal RNAseq analyses suggest that this likely transport is supplemented with enzymes produced in situ Our findings support that the maintenance of an external fungus comb, inoculated with an optimal mix of plant material, fungal spores, and enzymes, is likely the key...

Functional diversity of carbohydrate-active enzymes enabling a bacterium to ferment plant biomass.

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Boutard, Magali; Cerisy, Tristan; Nogue, Pierre-Yves; Alberti, Adriana; Weissenbach, Jean; Salanoubat, Marcel; Tolonen, Andrew C

2014-11-01

Microbial metabolism of plant polysaccharides is an important part of environmental carbon cycling, human nutrition, and industrial processes based on cellulosic bioconversion. Here we demonstrate a broadly applicable method to analyze how microbes catabolize plant polysaccharides that integrates carbohydrate-active enzyme (CAZyme) assays, RNA sequencing (RNA-seq), and anaerobic growth screening. We apply this method to study how the bacterium Clostridium phytofermentans ferments plant biomass components including glucans, mannans, xylans, galactans, pectins, and arabinans. These polysaccharides are fermented with variable efficiencies, and diauxies prioritize metabolism of preferred substrates. Strand-specific RNA-seq reveals how this bacterium responds to polysaccharides by up-regulating specific groups of CAZymes, transporters, and enzymes to metabolize the constituent sugars. Fifty-six up-regulated CAZymes were purified, and their activities show most polysaccharides are degraded by multiple enzymes, often from the same family, but with divergent rates, specificities, and cellular localizations. CAZymes were then tested in combination to identify synergies between enzymes acting on the same substrate with different catalytic mechanisms. We discuss how these results advance our understanding of how microbes degrade and metabolize plant biomass.

Alpha-Glucosidase Enzyme Biosensor for the Electrochemical Measurement of Antidiabetic Potential of Medicinal Plants.

Science.gov (United States)

Mohiuddin, M; Arbain, D; Islam, A K M Shafiqul; Ahmad, M S; Ahmad, M N

2016-12-01

A biosensor for measuring the antidiabetic potential of medicinal plants was developed by covalent immobilization of α-glucosidase (AG) enzyme onto amine-functionalized multi-walled carbon nanotubes (MWCNTs-NH2). The immobilized enzyme was entrapped in freeze-thawed polyvinyl alcohol (PVA) together with p-nitrophenyl-α-D-glucopyranoside (PNPG) on the screen-printed carbon electrode at low pH to prevent the premature reaction between PNPG and AG enzyme. The enzymatic reaction within the biosensor is inhibited by bioactive compounds in the medicinal plant extracts. The capability of medicinal plants to inhibit the AG enzyme on the electrode correlates to the potential of the medicinal plants to inhibit the production of glucose from the carbohydrate in the human body. Thus, the inhibition indicates the antidiabetic potential of the medicinal plants. The performance of the biosensor was evaluated to measure the antidiabetic potential of three medicinal plants such as Tebengau (Ehretis laevis), Cemumar (Micromelum pubescens), and Kedondong (Spondias dulcis) and acarbose (commercial antidiabetic drug) via cyclic voltammetry, amperometry, and spectrophotometry. The cyclic voltammetry (CV) response for the inhibition of the AG enzyme activity by Tebengau plant extracts showed a linear relation in the range from 0.423-8.29 μA, and the inhibition detection limit was 0.253 μA. The biosensor exhibited good sensitivity (0.422 μA/mg Tebengau plant extracts) and rapid response (22 s). The biosensor retains approximately 82.16 % of its initial activity even after 30 days of storage at 4 °C.

Survival of Bemisia tabaci and activity of plant defense-related enzymes in genotypes of Capsicum annuum L.

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Luis Latournerie-Moreno

2015-03-01

Full Text Available The whitefly Bemisia tabaci (Gennadius, 1889 is a major plant pest of horticultural crops from the families Solanaceae, Fabaceae and Cucurbitaceae in Neotropical areas. The exploration of host plant resistance and their biochemical mechanisms offers an excellent alternative to better understand factors affecting the interaction between phytophagous insect and host plant. We evaluated the survival of B. tabaci in landrace genotypes of Capsicum annuum L., and the activity of plant defense-related enzymes (chitinase, polyphenoloxidase, and peroxidase. The landrace genotypes Amaxito, Tabaquero, and Simojovel showed resistance to B. tabaci, as we observed more than 50% nymphal mortality, while in the commercial susceptible genotype Jalapeño mortality of B. tabaci nymphs was not higher than 20%. The activities of plant defense-related enzymes were significantly different among pepper genotypes (P < 0.05. Basal activities of chitinase, polyphenoloxidase and peroxidase were significantly lower or equal in landrace genotypes than that of the commercial genotype Jalapeño. The activity of plant enzymes was differential among pepper genotypes (P < 0.05. For example, the activity of chitinase enzyme generally was higher in non-infested plants with B. tabaci than those infested. Instead polyphenoloxidase ('Amaxito' and 'Simojovel' and peroxidase enzymes activities ('Tabaquero' increased in infested plants (P < 0.05. We conclude that basal activities of plant defense-related enzymes could be act through other mechanism plant induction, since plant defense-related enzymes showed a different induction response to B. tabaci. We underlined the role of polyphenoloxidase as plant defense in the pepper genotype Simojovel related to B. tabaci.

A plant gene for photolyase: an enzyme catalyzing the repair of UV-light-induced DNA damage

International Nuclear Information System (INIS)

Batschauer, A.

1993-01-01

Photolyases are thought to be critical components of the defense of plants against damage to DNA by solar ultraviolet light, but nothing is known about their molecular or enzymatic nature. The molecular cloning of a photolyase from mustard (Sinapis alba) described here is intended to increase the knowledge about this important repair mechanism in plant species at a molecular level. The gene encodes a polypeptide of 501 amino acids with a predicted molecular mass of 57 kDa. There is a strong sequence similarity to bacterial and yeast photolyases, with a close relationship to enzymes with a deazaflavin chromophor. The plant photolyase is shown to be functional in Escherichia coli which also indicates conservation of photolyases during evolution. It is demonstrated that photolyase expression in plants is light induced, thus providing good evidence for the adaptation of plants to their environment in order to diminish the harmful effects of sunlight. (author)

Plant lipid environment and membrane enzymes: the case of the plasma membrane H+-ATPase.

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Morales-Cedillo, Francisco; González-Solís, Ariadna; Gutiérrez-Angoa, Lizbeth; Cano-Ramírez, Dora Luz; Gavilanes-Ruiz, Marina

2015-04-01

Several lipid classes constitute the universal matrix of the biological membranes. With their amphipathic nature, lipids not only build the continuous barrier that confers identity to every cell and organelle, but they are also active actors that modulate the activity of the proteins immersed in the lipid bilayer. The plasma membrane H(+)-ATPase, an enzyme from plant cells, is an excellent example of a transmembrane protein whose activity is influenced by the hydrophilic compartments at both sides of the membrane and by the hydrophobic domains of the lipid bilayer. As a result, an extensive documentation of the effect of numerous amphiphiles in the enzyme activity can be found. Detergents, membrane glycerolipids, and sterols can produce activation or inhibition of the enzyme activity. In some cases, these effects are associated with the lipids of the membrane bulk, but in others, a direct interaction of the lipid with the protein is involved. This review gives an account of reports related to the action of the membrane lipids on the H(+)-ATPase activity.

Effects of natural plant tenderizers on proteolysis and texture of dry ...

African Journals Online (AJOL)

, and overall acceptability. From these results, it is shown that those enzymes as a raw plant juices could be used as tenderizers in dry sausage production. Keywords: Dry sausages, wild boar meat, plant enzymes, proteolysis, texture, sensory ...

Vacuolar processing enzyme in plant programmed cell death

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Noriyuki eHatsugai

2015-04-01

Full Text Available Vacuolar processing enzyme (VPE is a cysteine proteinase originally identified as the proteinase responsible for the maturation and activation of vacuolar proteins in plants, and it is known to be an orthologue of animal asparaginyl endopeptidase (AEP/VPE/legumain. VPE has been shown to exhibit enzymatic properties similar to that of caspase 1, which is a cysteine protease that mediates the programmed cell death (PCD pathway in animals. Although there is limited sequence identity between VPE and caspase 1, their predicted three-dimensional structures revealed that the essential amino-acid residues for these enzymes form similar pockets for the substrate peptide YVAD. In contrast to the cytosolic localization of caspases, VPE is localized in vacuoles. VPE provokes vacuolar rupture, initiating the proteolytic cascade leading to PCD in the plant immune response. It has become apparent that the VPE-dependent PCD pathway is involved not only in the immune response, but also in the responses to a variety of stress inducers and in the development of various tissues. This review summarizes the current knowledge on the contribution of VPE to plant PCD and its role in vacuole-mediated cell death, and it also compares VPE with the animal cell death executor caspase 1.

Enzymes in biogenesis of plant cell wall polysaccharides. Enzyme characterization using tracer techniques

International Nuclear Information System (INIS)

Dickinson, D.B.

1975-01-01

Enzymes and metabolic pathways, by which starch and cell wall polysaccharides are formed, were investigated in order to learn how these processes are regulated and to identify the enzymatic regulatory mechanisms involved. Germinating lily pollen was used for studies of cell wall formation, and pollen and maize endosperm for studies of starch biosynthesis. Hexokinase being the first step in conversion of hexoses to starch, wall polysaccharides and respiratory substrates, maize endosperm enzyme was assayed by its conversion of 14 C-hexose to 14 C-hexose-6-P, and rapid separation of the two labelled compounds on anion-exchange paper. This enzyme did not appear to be under tight regulation by feed-back inhibition or activation, nor to be severely inhibited by glucose-6-P or activated by citrate. ADP-glucose pyrophosphorylase and other pyrophosphorylases were assayed radiochemically with 14 C-glucose-1-P (forward direction) or 32-PPsub(i) (reverse direction). They showed that the maize endosperm enzyme was activated by the glycolytic intermediates fructose-6-P and 3-phosphoglycerate, and that low levels of the enzyme were present in the high sucrose-low starch mutant named shrunken-2. Under optimal in-vitro assay conditions, the pollen enzyme reacted four times faster than the observed in-vivo rate of starch accumulation. Biogenesis of plant cell wall polysaccharides requires the conversion of hexose phosphates to various sugar nucleotides and utilization of the latter by the appropriate polysaccharide synthetases. Lily pollen possesses a β-1,3-glucan synthetase which is activated up to six-fold by β-linked oligosaccharides. Hence, the in-vivo activity of this enzyme may be modulated by such effector molecules

Diverse effects of arsenic on selected enzyme activities in soil-plant-microbe interactions.

Science.gov (United States)

Lyubun, Yelena V; Pleshakova, Ekaterina V; Mkandawire, Martin; Turkovskaya, Olga V

2013-11-15

Under the influence of pollutants, enzyme activities in plant-microbe-soil systems undergo changes of great importance in predicting soil-plant-microbe interactions, regulation of metal and nutrient uptake, and, ultimately, improvement of soil health and fertility. We evaluated the influence of As on soil enzyme activities and the effectiveness of five field crops for As phytoextraction. The initial As concentration in soil was 50mg As kg(-1) soil; planted clean soil, unplanted polluted soil, and unplanted clean soil served as controls. After 10 weeks, the growth of the plants elevated soil dehydrogenase activity relative to polluted but unplanted control soils by 2.4- and 2.5-fold for sorghum and sunflower (respectively), by 3-fold for ryegrass and sudangrass, and by 5.2-fold for spring rape. Soil peroxidase activity increased by 33% with ryegrass and rape, while soil phosphatase activity was directly correlated with residual As (correlation coefficient R(2)=0.7045). We conclude that soil enzyme activities should be taken into account when selecting plants for phytoremediation. Copyright © 2013 Elsevier B.V. All rights reserved.

Gaseous environment of plants and activity of enzymes of carbohydrate catabolism

International Nuclear Information System (INIS)

Ivanov, B.F.; Zemlyanukhin, A.A.; Igamberdiev, A.U.; Salam, A.M.M.

1989-01-01

The authors investigated the action of hypoxia and high CO 2 concentration in the atmosphere on activity of phosphofructokinase, aldolase, glucose phosphate isomerase, glucose-6-phosphate dehydrogenase, lactate dehydrogenase, alcohol dehydrogenase, and isocitrate lyase in pea seedlings (Pisum sativum L.), corn scutella (Zea mays L.), and hemp cotyledons (Cannabis sativa L.). The first 4-12h of hypoxia witnessed suppression of enzymes of the initial stages of glycolysis (glucose-6-phosphate isomerase, phosphofructokinase)and activation of enzymes of its final stages (alcohol dehydrogenase and lactate dehydrogenase) and enzymes linking glycolysis and the pentose phosphate pathway (aldolase and glucose-6-phosphate dehydrogenase). An excess of CO 2 in the environment accelerated and amplified this effect. At the end of a 24-h period of anaerobic incubation, deviations of enzyme activity from the control were leveled in both gaseous environments. An exception was observed in the case of phosphofructokinase, whose activity increased markedly at this time in plants exposed to CO 2 . Changes in activity of the enzymes were coupled with changes in their kinetic parameters (apparent K m and V max values). The activity of isocitrate lyase was suppressed in both variants of hypoxic gaseous environments, a finding that does not agree with the hypothesis as to participation of the glyoxylate cycle in the metabolic response of plants to oxygen stress. Thus, temporary inhibition of the system of glycolysis and activation of the pentose phosphate pathway constituted the initial response of the plants to O 2 stress, and CO 2 intensified this metabolic response

SAM-dependent enzyme-catalysed pericyclic reactions in natural product biosynthesis

Science.gov (United States)

Ohashi, Masao; Liu, Fang; Hai, Yang; Chen, Mengbin; Tang, Man-Cheng; Yang, Zhongyue; Sato, Michio; Watanabe, Kenji; Houk, K. N.; Tang, Yi

2017-09-01

Pericyclic reactions—which proceed in a concerted fashion through a cyclic transition state—are among the most powerful synthetic transformations used to make multiple regioselective and stereoselective carbon-carbon bonds. They have been widely applied to the synthesis of biologically active complex natural products containing contiguous stereogenic carbon centres. Despite the prominence of pericyclic reactions in total synthesis, only three naturally existing enzymatic examples (the intramolecular Diels-Alder reaction, and the Cope and the Claisen rearrangements) have been characterized. Here we report a versatile S-adenosyl-L-methionine (SAM)-dependent enzyme, LepI, that can catalyse stereoselective dehydration followed by three pericyclic transformations: intramolecular Diels-Alder and hetero-Diels-Alder reactions via a single ambimodal transition state, and a retro-Claisen rearrangement. Together, these transformations lead to the formation of the dihydropyran core of the fungal natural product, leporin. Combined in vitro enzymatic characterization and computational studies provide insight into how LepI regulates these bifurcating biosynthetic reaction pathways by using SAM as the cofactor. These pathways converge to the desired biosynthetic end product via the (SAM-dependent) retro-Claisen rearrangement catalysed by LepI. We expect that more pericyclic biosynthetic enzymatic transformations remain to be discovered in naturally occurring enzyme ‘toolboxes’. The new role of the versatile cofactor SAM is likely to be found in other examples of enzyme catalysis.

Role of Proteolytic Enzymes in the Interaction of Phytopathogenic Microorganisms with Plants.

Science.gov (United States)

Valueva, T A; Zaichik, B Ts; Kudryavtseva, N N

2016-12-01

Various forms of participation of proteolytic enzymes in pathogenesis and defense in plants are reviewed. Along with extracellular proteinases, phytopathogenic microorganisms produce specific effectors having proteolytic activity and capable of acting on proteins inside plant cells. In turn, for defense against pathogens, plants use both extracellular and intracellular proteinases.

Carbohydrate-related enzymes of important Phytophthora plant pathogens.

Science.gov (United States)

Brouwer, Henk; Coutinho, Pedro M; Henrissat, Bernard; de Vries, Ronald P

2014-11-01

Carbohydrate-Active enZymes (CAZymes) form particularly interesting targets to study in plant pathogens. Despite the fact that many CAZymes are pathogenicity factors, oomycete CAZymes have received significantly less attention than effectors in the literature. Here we present an analysis of the CAZymes present in the Phytophthora infestans, Ph. ramorum, Ph. sojae and Pythium ultimum genomes compared to growth of these species on a range of different carbon sources. Growth on these carbon sources indicates that the size of enzyme families involved in degradation of cell-wall related substrates like cellulose, xylan and pectin is not always a good predictor of growth on these substrates. While a capacity to degrade xylan and cellulose exists the products are not fully saccharified and used as a carbon source. The Phytophthora genomes encode larger CAZyme sets when compared to Py. ultimum, and encode putative cutinases, GH12 xyloglucanases and GH10 xylanases that are missing in the Py. ultimum genome. Phytophthora spp. also encode a larger number of enzyme families and genes involved in pectin degradation. No loss or gain of complete enzyme families was found between the Phytophthora genomes, but there are some marked differences in the size of some enzyme families. Copyright © 2014 Elsevier Inc. All rights reserved.

Vacuolar processing enzyme: an executor of plant cell death.

Science.gov (United States)

Hara-Nishimura, Ikuko; Hatsugai, Noriyuki; Nakaune, Satoru; Kuroyanagi, Miwa; Nishimura, Mikio

2005-08-01

Apoptotic cell death in animals is regulated by cysteine proteinases called caspases. Recently, vacuolar processing enzyme (VPE) was identified as a plant caspase. VPE deficiency prevents cell death during hypersensitive response and cell death of limited cell layers at the early stage of embryogenesis. Because plants do not have macrophages, dying cells must degrade their materials by themselves. VPE plays an essential role in the regulation of the lytic system of plants during the processes of defense and development. VPE is localized in the vacuoles, unlike animal caspases, which are localized in the cytosol. Thus, plants might have evolved a regulated cellular suicide strategy that, unlike animal apoptosis, is mediated by VPE and the vacuoles.

Convergent evolution of caffeine in plants by co-option of exapted ancestral enzymes.

Science.gov (United States)

Huang, Ruiqi; O'Donnell, Andrew J; Barboline, Jessica J; Barkman, Todd J

2016-09-20

Convergent evolution is a process that has occurred throughout the tree of life, but the historical genetic and biochemical context promoting the repeated independent origins of a trait is rarely understood. The well-known stimulant caffeine, and its xanthine alkaloid precursors, has evolved multiple times in flowering plant history for various roles in plant defense and pollination. We have shown that convergent caffeine production, surprisingly, has evolved by two previously unknown biochemical pathways in chocolate, citrus, and guaraná plants using either caffeine synthase- or xanthine methyltransferase-like enzymes. However, the pathway and enzyme lineage used by any given plant species is not predictable from phylogenetic relatedness alone. Ancestral sequence resurrection reveals that this convergence was facilitated by co-option of genes maintained over 100 million y for alternative biochemical roles. The ancient enzymes of the Citrus lineage were exapted for reactions currently used for various steps of caffeine biosynthesis and required very few mutations to acquire modern-day enzymatic characteristics, allowing for the evolution of a complete pathway. Future studies aimed at manipulating caffeine content of plants will require the use of different approaches given the metabolic and genetic diversity revealed by this study.

Natural AChE Inhibitors from Plants and their Contribution to Alzheimer's Disease Therapy.

Science.gov (United States)

Murray, Ana Paula; Faraoni, María Belén; Castro, María Julia; Alza, Natalia Paola; Cavallaro, Valeria

2013-07-01

As acetylcholinesterase (AChE) inhibitors are an important therapeutic strategy in Alzheimer's disease, efforts are being made in search of new molecules with anti-AChE activity. The fact that naturally-occurring compounds from plants are considered to be a potential source of new inhibitors has led to the discovery of an important number of secondary metabolites and plant extracts with the ability of inhibiting the enzyme AChE, which, according to the cholinergic hypothesis, increases the levels of the neurotransmitter acetylcholine in the brain, thus improving cholinergic functions in patients with Alzheimer's disease and alleviating the symptoms of this neurological disorder. This review summarizes a total of 128 studies which correspond to the most relevant research work published during 2006-2012 (1st semester) on plant-derived compounds, plant extracts and essential oils found to elicit AChE inhibition.

The lipoxygenase metabolic pathway in plants: potential for industrial production of natural green leaf volatiles

Directory of Open Access Journals (Sweden)

Gigot, C.

2010-01-01

Full Text Available Lipoxygenase enzymatic pathway is a widely studied mechanism in the plant kingdom. Combined actions of three enzymes: lipase, lipoxygenase (LOX and hydroperoxide lyase (HPL convert lipidic substrates such as C18:2 and C18:3 fatty acids into short chain volatiles. These reactions, triggered by cell membrane disruptions, produce compounds known as Green Leaf Volatiles (GLVs which are C6 or C9-aldehydes and alcohols. These GLVs are commonly used as flavors to confer a fresh green odor of vegetable to food products. Therefore, competitive biocatalytic productions have been developed to meet the high demand in these natural flavors. Vegetable oils, chosen for their lipidic acid profile, are converted by soybean LOX and plant HPL into natural GLVs. However this second step of the bioconversion presents low yield due to the HPL instability and the inhibition by its substrate. This paper will shortly describe the different enzymes involved in this bioconversion with regards to their chemical and enzymatic properties. Biotechnological techniques to enhance their production potentialities will be discussed along with their implication in a complete bioprocess, from the lipid substrate to the corresponding aldehydic or alcoholic flavors.

Three Newly Naturalized Plants in Taiwan

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Ming-Jer Jung

2009-11-01

Full Text Available Three newly naturalized plants are reported in this paper. Hypochaeris microcephala (Sch. Bip. Cabrera var. albiflora (Kuntze Cabrera (Asteraceae is naturalized in urban areas of northern Taiwan. Indigofera pseudo-tinctoria Matsum. (Leguminosae is naturalized in low elevations of northern and southern Taiwan and in middle elevations of central Taiwan. Lamium purpureum L. (Laminaceae has become naturalized locally in middle elevations of central Taiwan. Descriptions, illustrations and color photos of these plants are provided.

Enzyme oxidation of plant galactomannans yielding biomaterials with novel properties and applications, including as delivery systems.

Science.gov (United States)

Galante, Yves M; Merlini, Luca; Silvetti, Tiziana; Campia, Paola; Rossi, Bianca; Viani, Fiorenza; Brasca, Milena

2018-06-01

New biomaterials from renewable sources and the development of "functionalized biopolymers" are fields of growing industrial interest. Plant polysaccharides represent a valid alternative to traditional synthetic polymers, which are obtained from monomers of fossil, non-renewable origin. Several polysaccharides, either in their natural or chemically/biochemically modified forms, are currently employed in the biomedical, food and feed, and industrial fields, including packaging. Sustainable biochemical reactions, such as enzyme modifications of polysaccharides, open further possibilities for new product and process innovation. In the present review, we summarize the recent progress on enzyme oxidation of galactomannans (GM) from few leguminous plants (performed either with galactose oxidase or laccase) and we focus on the versatile and easily accessible laccase/TEMPO oxidative reaction. The latter causes a steep viscosity increase of GM water solutions and a transition of the gels from a viscous to an elastic form, due to formation of emiacetalic bonds and thus of internal cross-linking of the polymers. Following lyophilization of these hydrogels, stable aerogels can be obtained, which were shown to have good potential as delivery systems (DS) of actives. The active molecules tested and herewith described are polymyxin B, an antibiotic; nisin, an antimicrobial peptide; the enzymes lysozyme, protease and lipase; the mixture of the industrial microbiocides 5-chloro-2-methyl-4-isothiazolin-3-one (CIT) and 2-methyl-4-isothiazolin-3-one (MIT). The advantages of such aerogel systems and the possibilities they open for future developments, including as DS, are described.

Spatial distribution of enzyme activities along the root and in the rhizosphere of different plants

Science.gov (United States)

Razavi, Bahar S.; Zarebanadkouki, Mohsen; Blagodatskaya, Evgenia; Kuzyakov, Yakov

2015-04-01

Extracellular enzymes are important for decomposition of many biological macromolecules abundant in soil such as cellulose, hemicelluloses and proteins. Activities of enzymes produced by both plant roots and microbes are the primary biological drivers of organic matter decomposition and nutrient cycling. So far acquisition of in situ data about local activity of different enzymes in soil has been challenged. That is why there is an urgent need in spatially explicit methods such as 2-D zymography to determine the variation of enzymes along the roots in different plants. Here, we developed further the zymography technique in order to quantitatively visualize the enzyme activities (Spohn and Kuzyakov, 2013), with a better spatial resolution We grew Maize (Zea mays L.) and Lentil (Lens culinaris) in rhizoboxes under optimum conditions for 21 days to study spatial distribution of enzyme activity in soil and along roots. We visualized the 2D distribution of the activity of three enzymes:β-glucosidase, leucine amino peptidase and phosphatase, using fluorogenically labelled substrates. Spatial resolution of fluorescent images was improved by direct application of a substrate saturated membrane to the soil-root system. The newly-developed direct zymography shows different pattern of spatial distribution of enzyme activity along roots and soil of different plants. We observed a uniform distribution of enzyme activities along the root system of Lentil. However, root system of Maize demonstrated inhomogeneity of enzyme activities. The apical part of an individual root (root tip) in maize showed the highest activity. The activity of all enzymes was the highest at vicinity of the roots and it decreased towards the bulk soil. Spatial patterns of enzyme activities as a function of distance from the root surface were enzyme specific, with highest extension for phosphatase. We conclude that improved zymography is promising in situ technique to analyze, visualize and quantify

Fungal Enzymes and Yeasts for Conversion of Plant Biomass to Bioenergy and High-Value Products

DEFF Research Database (Denmark)

Lange, Lene

2017-01-01

Fungi and fungal enzymes play important roles in the new bioeconomy. Enzymes from filamentous fungi can unlock the potential of recalcitrant lignocellulose structures of plant cell walls as a new resource, and fungi such as yeast can produce bioethanol from the sugars released after enzyme treatm...... contributed to mycology and environmental research? Future perspectives and approaches are listed, highlighting the importance of fungi in development of the bioeconomy.......Fungi and fungal enzymes play important roles in the new bioeconomy. Enzymes from filamentous fungi can unlock the potential of recalcitrant lignocellulose structures of plant cell walls as a new resource, and fungi such as yeast can produce bioethanol from the sugars released after enzyme...... treatment. Such processes reflect inherent characteristics of the fungal way of life, namely, that fungi as heterotrophic organisms must break down complex carbon structures of organic materials to satisfy their need for carbon and nitrogen for growth and reproduction. This chapter describes major steps...

A saponin-detoxifying enzyme mediates suppression of plant defences

Science.gov (United States)

Bouarab, K.; Melton, R.; Peart, J.; Baulcombe, D.; Osbourn, A.

2002-08-01

Plant disease resistance can be conferred by constitutive features such as structural barriers or preformed antimicrobial secondary metabolites. Additional defence mechanisms are activated in response to pathogen attack and include localized cell death (the hypersensitive response). Pathogens use different strategies to counter constitutive and induced plant defences, including degradation of preformed antimicrobial compounds and the production of molecules that suppress induced plant defences. Here we present evidence for a two-component process in which a fungal pathogen subverts the preformed antimicrobial compounds of its host and uses them to interfere with induced defence responses. Antimicrobial saponins are first hydrolysed by a fungal saponin-detoxifying enzyme. The degradation product of this hydrolysis then suppresses induced defence responses by interfering with fundamental signal transduction processes leading to disease resistance.

Natural and Synthetic Macrocyclic Inhibitors of the Histone Deacetylase Enzymes

DEFF Research Database (Denmark)

Maolanon, Alex; Kristensen, Helle; Leman, Luke

2017-01-01

Inhibition of histone deacetylase (HDAC) enzymes has emerged as a target for development of cancer chemotherapy. Four compounds have gained approval for clinical use by the Food and Drug Administration (FDA) in the US, and several are currently in clinical trials. However, none of these compounds...... HDAC enzymes may hold an advantage over traditional hydroxamic acid-containing inhibitors, which rely on chelation to the conserved active site zinc ion. Here, we review the literature on macrocyclic HDAC inhibitors obtained from natural sources and structure-activity relationship studies inspired...

Enzyme inhibitory and radical scavenging effects of some antidiabetic plants of Turkey

Science.gov (United States)

Orhan, Nilüfer; Hoçbaç, Sanem; Orhan, Didem Deliorman; Asian, Mustafa; Ergun, Fatma

2014-01-01

Objective(s): Ethnopharmacological field surveys demonstrated that many plants, such as Gentiana olivieri, Helichrysum graveolens, Helichrysum plicatum ssp. plicatum, Juniperus oxycedrus ssp. oxycedrus, Juniperus communis var. saxatilis, Viscum album (ssp. album, ssp. austriacum), are used as traditional medicine for diabetes in different regions of Anatolia. The present study was designed to evaluate the in vitro antidiabetic effects of some selected plants, tested in animal models recently. Materials and Methods: α-glucosidase and α-amylase enzyme inhibitory effects of the plant extracts were investigated and Acarbose was used as a reference drug. Additionally, radical scavenging capacities were determined using 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) ABTS radical cation scavenging assay and total phenolic content of the extracts were evaluated using Folin Ciocalteu method. Results: H. graveolens ethanol extract exhibited the highest inhibitory activity (55.7 % ± 2.2) on α-amylase enzyme. Additionally, J. oxycedrus hydro-alcoholic leaf extract had potent α-amylase inhibitory effect, while the hydro-alcoholic extract of J. communis fruit showed the highest α-glucosidase inhibitory activity (IC50: 4.4 μg/ml). Conclusion: Results indicated that, antidiabetic effect of hydro-alcoholic extracts of H. graveolens capitulums, J. communis fruit and J. oxycedrus leaf might arise from inhibition of digestive enzymes. PMID:25140204

Enzyme inhibitory and radical scavenging effects of some antidiabetic plants of Turkey

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Nilüfer Orhan

2014-06-01

Full Text Available Objective(s:Ethnopharmacological field surveys demonstrated that many plants, such as Gentiana olivieri, Helichrysum graveolens, Helichrysum plicatum ssp. plicatum, Juniperus oxycedrus ssp. oxycedrus, Juniperus  communis var. saxatilis, Viscum album (ssp. album, ssp. austriacum, are used as traditional medicine for diabetes in different regions of Anatolia. The present study was designed to evaluate the in vitro antidiabetic effects of some selected plants, tested in animal models recently. Materials and Methods: α-glucosidase and α-amylase enzyme inhibitory effects of the plant extracts were investigated and Acarbose was used as a reference drug. Additionally, radical scavenging capacities were determined using 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid ABTS radical cation scavenging assay and total phenolic content of the extracts were evaluated using Folin Ciocalteu method. Results: H. graveolens ethanol extract exhibited the highest inhibitory activity (55.7 % ± 2.2 on α-amylase enzyme. Additionally, J. oxycedrus hydro-alcoholic leaf extract had potent α-amylase inhibitory effect, while the hydro-alcoholic extract of J. communis fruit showed the highest α-glucosidase inhibitory activity (IC50: 4.4 μg/ml. Conclusion:Results indicated that, antidiabetic effect of hydro-alcoholic extracts of H. graveolens capitulums, J. communis fruit and J. oxycedrus leaf might arise from inhibition of digestive enzymes.

Control of biofouling by xanthine oxidase on seawater reverse osmosis membranes from a desalination plant: enzyme production and screening of bacterial isolates from the full-scale plant.

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Nagaraj, V; Skillman, L; Li, D; Xie, Z; Ho, G

2017-07-01

Control of biofouling on seawater reverse osmosis (SWRO) membranes is a major challenge as treatments can be expensive, damage the membrane material and often biocides do not remove the polymers in which bacteria are embedded. Biological control has been largely ignored for biofouling control. The objective of this study was to demonstrate the effectiveness of xanthine oxidase enzyme against complex fouling communities and then identify naturally occurring bacterial strains that produce the free radical generating enzyme. Initially, 64 bacterial strains were isolated from different locations of the Perth Seawater Desalination Plant. In our preceding study, 25/64 isolates were selected from the culture collection as models for biofouling studies, based on their prevalence in comparison to the genomic bacterial community. In this study, screening of these model strains was performed using a nitroblue tetrazolium assay in the presence of hypoxanthine as substrate. Enzyme activity was measured by absorbance. Nine of 25 strains tested positive for xanthine oxidase production, of which Exiguobacterium from sand filters and Microbacterium from RO membranes exhibited significant levels of enzyme production. Other genera that produced xanthine oxidase were Marinomonas, Pseudomonas, Bacillus, Pseudoalteromonas and Staphylococcus. Strain variations were observed between members of the genera Microbacterium and Bacillus. Xanthine oxidase, an oxidoreductase enzyme that generates reactive oxygen species, is endogenously produced by many bacterial species. In this study, production of the enzyme by bacterial isolates from a full-scale desalination plant was investigated for potential use as biological control of membrane fouling in seawater desalination. We have previously demonstrated that free radicals generated by a commercially available xanthine oxidase in the presence of a hypoxanthine substrate, effectively dispersed biofilm polysaccharides on industrially fouled membranes

Plant Growth-Promoting Rhizobacteria Enhance Salinity Stress Tolerance in Okra through ROS-Scavenging Enzymes

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Sheikh Hasna Habib

2016-01-01

Full Text Available Salinity is a major environmental stress that limits crop production worldwide. In this study, we characterized plant growth-promoting rhizobacteria (PGPR containing 1-aminocyclopropane-1-carboxylate (ACC deaminase and examined their effect on salinity stress tolerance in okra through the induction of ROS-scavenging enzyme activity. PGPR inoculated okra plants exhibited higher germination percentage, growth parameters, and chlorophyll content than control plants. Increased antioxidant enzyme activities (SOD, APX, and CAT and upregulation of ROS pathway genes (CAT, APX, GR, and DHAR were observed in PGPR inoculated okra plants under salinity stress. With some exceptions, inoculation with Enterobacter sp. UPMR18 had a significant influence on all tested parameters under salt stress, as compared to other treatments. Thus, the ACC deaminase-containing PGPR isolate Enterobacter sp. UPMR18 could be an effective bioresource for enhancing salt tolerance and growth of okra plants under salinity stress.

Chemometrics Optimized Extraction Procedures, Phytosynergistic Blending and in vitro Screening of Natural Enzyme Inhibitors Amongst Leaves of Tulsi, Banyan and Jamun.

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De, Baishakhi; Bhandari, Koushik; Singla, Rajeev K; Katakam, Prakash; Samanta, Tanmoy; Kushwaha, Dilip Kumar; Gundamaraju, Rohit; Mitra, Analava

2015-10-01

Tulsi, Banyan, and Jamun are popular Indian medicinal plants with notable hypoglycemic potentials. Now the work reports chemo-profiling of the three species with in-vitro screening approach for natural enzyme inhibitors (NEIs) against enzymes pathogenic for type 2 diabetes. Further along with the chemometrics optimized extraction process technology, phyto-synergistic studies of the composite polyherbal blends have also been reported. Chemometrically optimized extraction procedures, ratios of polyherbal composites to achieve phyto-synergistic actions, and in-vitro screening of NEIs amongst leaves of Tulsi, Banyan, and Jamun. The extraction process parameters of the leaves of three plant species (Ficus benghalensis, Syzigium cumini and Ocimum sanctum) were optimized by rotatable central composite design of chemometrics so as to get maximal yield of bio-actives. Phyto-blends of three species were prepared so as to achieve synergistic antidiabetic and antioxidant potentials and the ratios were optimized by chemometrics. Next, for in vitro screening of natural enzyme inhibitors the individual leaf extracts as well as composite blends were subjected to assay procedures to see their inhibitory potentials against the enzymes pathogenic in type 2 diabetes. The antioxidant potentials were also estimated by DPPH radical scavenging, ABTS, FRAP and Dot Blot assay. Considering response surface methodology studies and from the solutions obtained using desirability function, it was found that hydro-ethanolic or methanolic solvent ratio of 52.46 ± 1.6 and at a temperature of 20.17 ± 0.6 gave an optimum yield of polyphenols with minimal chlorophyll leaching. The species also showed the presence of glycosides, alkaloids, and saponins. Composites in the ratios of 1:1:1 and 1:1:2 gave synergistic effects in terms of polyphenol yield and anti-oxidant potentials. All composites (1:1:1, 1:2:1, 2:1:1, 1:1:2) showed synergistic anti-oxidant actions. Inhibitory activities against the

Enzymes from Higher Eukaryotes for Industrial Biocatalysis

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Zhibin Liu

2004-01-01

Full Text Available The industrial production of fine chemicals, feed and food ingredients, pharmaceuticals, agrochemicals and their respective intermediates relies on an increasing application of biocatalysis, i.e. on enzyme or whole-cell catalyzed conversions of molecules. Simple procedures for discovery, cloning and over-expression as well as fast growth favour fungi, yeasts and especially bacteria as sources of biocatalysts. Higher eukaryotes also harbour an almost unlimited number of potential biocatalysts, although to date the limited supply of enzymes, the high heterogeneity of enzyme preparations and the hazard of infectious contaminants keep some interesting candidates out of reach for industrial bioprocesses. In the past only a few animal and plant enzymes from agricultural waste materials were employed in food processing. The use of bacterial expression strains or non-conventional yeasts for the heterologous production of efficient eukaryotic enzymes can overcome the bottleneck in enzyme supply and provide sufficient amounts of homogenous enzyme preparations for reliable and economically feasible applications at large scale. Ideal enzymatic processes represent an environmentally friendly, »near-to-completion« conversion of (mostly non-natural substrates to pure products. Recent developments demonstrate the commercial feasibility of large-scale biocatalytic processes employing enzymes from higher eukaryotes (e.g. plants, animals and also their usefulness in some small-scale industrial applications.

Inhibition and kinetic studies of lignin degrading enzymes of Ganoderma boninense by naturally occurring phenolic compounds.

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Surendran, Arthy; Siddiqui, Yasmeen; Saud, Halimi Mohd; Ali, Nusaibah Syd; Manickam, Sivakumar

2018-05-22

Lignolytic (Lignin degrading) enzyme, from oil palm pathogen Ganoderma boninense Pat. (Syn G. orbiforme (Ryvarden), is involved in the detoxification and the degradation of lignin in the oil palm and is the rate-limiting step in the infection process of this fungus. Active inhibition of lignin degrading enzymes secreted by G. boninense by various naturally occurring phenolic compounds and estimation of efficiency on pathogen suppression was aimed at. In our work, ten naturally occurring phenolic compounds were evaluated for their inhibitory potential towards the lignolytic enzymes of G.boninense. Additionally, the lignin degrading enzymes were characterised. Most of the peholic compounds exhibited an uncompetitive inhibition towards the lignin degrading enzymes. Benzoic acid was the superior inhibitor to the production of lignin degrading enzymes, when compared between the ten phenolic compounds. The inhibitory potential of the phenolic compounds toward the lignin degrading enzymes are higher than that of the conventional metal ion inhibitor. The lignin degrading enzymes were stable in a wide range of pH but were sensitive to higher to temperature. The study demonstrated the inhibitor potential of ten naturally occurring phenolic compounds toward the lignin degrading enzymes of G. boninense with different efficacies. The study has shed a light towards a new management strategy to control BSR in oil palm. It serves as replacement for the existing chemical control. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Enzyme (re)design: lessons from natural evolution and computation.

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Gerlt, John A; Babbitt, Patricia C

2009-02-01

The (re)design of enzymes to catalyze 'new' reactions is a topic of considerable practical and intellectual interest. Directed evolution (random mutagenesis followed by screening/selection) has been used widely to identify novel biocatalysts. However, 'rational' approaches using either natural divergent evolution or computational predictions based on chemical principles have been less successful. This review summarizes recent progress in evolution-based and computation-based (re)design.

Effect of parenteral serum plant sterols on liver enzymes and cholesterol metabolism in a patient with short bowel syndrome.

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Hallikainen, Maarit; Huikko, Laura; Kontra, Kirsi; Nissinen, Markku; Piironen, Vieno; Miettinen, Tatu; Gylling, Helena

2008-01-01

Hepatobiliary complications are common during parenteral nutrition. Lipid moiety in commercially available solutions contains plant sterols. It is not known whether plant sterols in parenteral nutrition interfere with hepatic function in adults. We detected how different amounts of plant sterols in parenteral nutrition solution affected serum plant sterol concentrations and liver enzymes during a 1.5-year follow-up in a patient with short bowel syndrome. Serum lipid, plant sterol, and liver enzyme levels were measured regularly during the transition from Intralipid (100% soy-based intravenous fat emulsion) to ClinOleic (an olive oil-based intravenous fat emulsion with 80% olive oil, 20% soy oil and lower plant sterols); the lipid supply was also gradually increased from 20 to 35 g/d. Plant sterols in parenteral nutrition solution and serum were measured with gas-liquid chromatography. During infusion of soy-based intravenous fat emulsion (30 g/d, total plant sterols 87 mg/d), the concentrations of sitosterol, campesterol, and stigmasterol were 4361, 1387, and 378 microg/dL, respectively, and serum liver enzyme values were >or= 2.5 times above upper limit of normal. After changing to olive oil-based intravenous fat emulsion (20-35 g/d, plant sterols 37-65 mg/d), concentrations decreased to 2148 to 2251 microg/dL for sitosterol, 569-297 microg/dL for campesterol, and 95-55 microg/dL for stigmasterol. Concomitantly, liver enzyme values decreased to 1.4 to 1.8 times above upper limit of normal at the end of follow-up. The nutrition status of the patient improved. The amount of plant sterols in lipid emulsion affects serum liver enzyme levels more than the amount of lipid.

Something Old, Something New: Conserved Enzymes and the Evolution of Novelty in Plant Specialized Metabolism1

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Moghe, Gaurav D.; Last, Robert L.

2015-01-01

Plants produce hundreds of thousands of small molecules known as specialized metabolites, many of which are of economic and ecological importance. This remarkable variety is a consequence of the diversity and rapid evolution of specialized metabolic pathways. These novel biosynthetic pathways originate via gene duplication or by functional divergence of existing genes, and they subsequently evolve through selection and/or drift. Studies over the past two decades revealed that diverse specialized metabolic pathways have resulted from the incorporation of primary metabolic enzymes. We discuss examples of enzyme recruitment from primary metabolism and the variety of paths taken by duplicated primary metabolic enzymes toward integration into specialized metabolism. These examples provide insight into processes by which plant specialized metabolic pathways evolve and suggest approaches to discover enzymes of previously uncharacterized metabolic networks. PMID:26276843

Lead action on activity of some enzymes of plants

International Nuclear Information System (INIS)

Korolyov, A.N.; Koshkaryova, A.I.

2008-01-01

Lead action on activity of some enzymes of young plants of barley double-row (Hordeum distichon L.) families of cereals (Grominea). It is established that activity urease, catalase, ascorbatoxidase is in dependence as from a lead dose in a nutritious solution, and term ontogenesis. At later stages ontogenesis the increase in concentration of lead in an inhabitancy leads to sharp decrease in activity ascorbatoxidase. In the same conditions activity urease and catalase raises.

Natural variations in xenobiotic-metabolizing enzymes: developing tools for coral monitoring

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Rougée, L. R. A.; Richmond, R. H.; Collier, A. C.

2014-06-01

The continued deterioration of coral reefs worldwide demonstrates the need to develop diagnostic tools for corals that go beyond general ecological monitoring and can identify specific stressors at sublethal levels. Cellular diagnostics present an approach to defining indicators (biomarkers) that have the potential to reflect the impact of stress at the cellular level, allowing for the detection of intracellular changes in corals prior to outright mortality. Detoxification enzymes, which may be readily induced or inhibited by environmental stressors, present such a set of indicators. However, in order to apply these diagnostic tools for the detection of stress, a detailed understanding of their normal, homeostatic levels within healthy corals must first be established. Herein, we present molecular and biochemical evidence for the expression and activity of major Phase I detoxification enzymes cytochrome P450 (CYP450), CYP2E1, and CYP450 reductase, as well as the Phase II enzymes UDP, glucuronosyltransferase (UGT), β-glucuronidase, glutathione- S-transferase (GST), and arylsulfatase C (ASC) in the coral Pocillopora damicornis. Additionally, we characterized enzyme expression and activity variations over a reproductive cycle within a coral's life history to determine natural endogenous changes devoid of stress exposure. Significant changes in enzyme activity over the coral's natural lunar reproductive cycle were observed for CYP2E1 and CYP450 reductase as well as UGT and GST, while β-glucuronidase and ASC did not fluctuate significantly. The data represent a baseline description of `health' for the expression and activity of these enzymes that can be used toward understanding the impact of environmental stressors on corals. Such knowledge can be applied to address causes of coral reef ecosystem decline and to monitor effectiveness of mitigation strategies. Achieving a better understanding of cause-and-effect relationships between putative stressors and biological

Heterologous Expression of Plant Cell Wall Degrading Enzymes for Effective Production of Cellulosic Biofuels

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Jung, Sang-Kyu; Parisutham, Vinuselvi; Jeong, Seong Hun; Lee, Sung Kuk

2012-01-01

A major technical challenge in the cost-effective production of cellulosic biofuel is the need to lower the cost of plant cell wall degrading enzymes (PCDE), which is required for the production of sugars from biomass. Several competitive, low-cost technologies have been developed to produce PCDE in different host organisms such as Escherichia coli, Zymomonas mobilis, and plant. Selection of an ideal host organism is very important, because each host organism has its own unique features. Synthetic biology-aided tools enable heterologous expression of PCDE in recombinant E. coli or Z. mobilis and allow successful consolidated bioprocessing (CBP) in these microorganisms. In-planta expression provides an opportunity to simplify the process of enzyme production and plant biomass processing and leads to self-deconstruction of plant cell walls. Although the future of currently available technologies is difficult to predict, a complete and viable platform will most likely be available through the integration of the existing approaches with the development of breakthrough technologies. PMID:22911272

Ecotoxicological effects of copper and selenium combined pollution on soil enzyme activities in planted and unplanted soils.

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Hu, Bin; Liang, Dongli; Liu, Juanjuan; Xie, Junyu

2013-04-01

The present study explored the joint effects of Cu and Se pollution mechanisms on soil enzymes to provide references for the phytoremediation of contaminated areas and agricultural environmental protection. Pot experiments and laboratory analyses were carried out to study the individual and combined influences of Cu and Se on soil enzyme activities. The activities of four soil enzymes (urease, catalase, alkaline phosphatase, and nitrate reductase) were chosen. All soil enzyme activities tested were inhibited by Cu and Se pollution, either individually or combined, in varying degrees, following the order nitrate reductase>urease>catalase>alkaline phosphatase. Growing plants stimulated soil enzyme activity in a similar trend compared with treatments without plants. The joint effects of Cu and Se on catalase activity showed synergism at low concentrations and antagonism at high concentrations, whereas the opposite was observed for urease activity. However, nitrate reductase activity showed synergism both with and without plant treatments. The half maximal effective concentration (EC50) of exchangeable fractions had a similar trend with the EC50 of total content and was lower than that of total content. The EC50 values of nitrate reductase and urease activities were significantly lower for both Se and Cu (p<0.05), which indicated that they were more sensitive than the other two enzymes. Copyright © 2013 SETAC.

Prequels to Synthetic Biology: From Candidate Gene Identification and Validation to Enzyme Subcellular Localization in Plant and Yeast Cells.

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Foureau, E; Carqueijeiro, I; Dugé de Bernonville, T; Melin, C; Lafontaine, F; Besseau, S; Lanoue, A; Papon, N; Oudin, A; Glévarec, G; Clastre, M; St-Pierre, B; Giglioli-Guivarc'h, N; Courdavault, V

2016-01-01

Natural compounds extracted from microorganisms or plants constitute an inexhaustible source of valuable molecules whose supply can be potentially challenged by limitations in biological sourcing. The recent progress in synthetic biology combined to the increasing access to extensive transcriptomics and genomics data now provide new alternatives to produce these molecules by transferring their whole biosynthetic pathway in heterologous production platforms such as yeasts or bacteria. While the generation of high titer producing strains remains per se an arduous field of investigation, elucidation of the biosynthetic pathways as well as characterization of their complex subcellular organization are essential prequels to the efficient development of such bioengineering approaches. Using examples from plants and yeasts as a framework, we describe potent methods to rationalize the study of partially characterized pathways, including the basics of computational applications to identify candidate genes in transcriptomics data and the validation of their function by an improved procedure of virus-induced gene silencing mediated by direct DNA transfer to get around possible resistance to Agrobacterium-delivery of viral vectors. To identify potential alterations of biosynthetic fluxes resulting from enzyme mislocalizations in reconstituted pathways, we also detail protocols aiming at characterizing subcellular localizations of protein in plant cells by expression of fluorescent protein fusions through biolistic-mediated transient transformation, and localization of transferred enzymes in yeast using similar fluorescence procedures. Albeit initially developed for the Madagascar periwinkle, these methods may be applied to other plant species or organisms in order to establish synthetic biology platform. © 2016 Elsevier Inc. All rights reserved.

Anthraquinone profile, antioxidant and enzyme inhibitory effect of root extracts of eight Asphodeline taxa from Turkey: can Asphodeline roots be considered as a new source of natural compounds?

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Zengin, Gokhan; Locatelli, Marcello; Ceylan, Ramazan; Aktumsek, Abdurrahman

2016-10-01

Plant-based foods have become attractive for scientists and food producers. Beneficial effects related to their consumption as dietary supplements are due to the presence of natural occurring secondary metabolites. In this context, studies on these products are important for natural and safely food ingredients evaluation. The aim of this study was to evaluate root extract of eight Asphodeline species as antioxidants, enzyme inhibitors and phytochemical content. Spectrophotometric antioxidant and enzyme inhibitory assays were performed. Total phenolic and flavonoids contents as well as the chemical free-anthraquinones profiles were determined using routinely procedure (HPLC-PDA). Data show that Asphodeline roots can be considered as a new source of natural compounds and can be used as a valuable dietary supplement. Some differences related to biological activities can be inferred to other phytochemicals that can be considered in the future for their synergic or competitive activities.

Deep Learning for Plant Identification in Natural Environment.

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Sun, Yu; Liu, Yuan; Wang, Guan; Zhang, Haiyan

2017-01-01

Plant image identification has become an interdisciplinary focus in both botanical taxonomy and computer vision. The first plant image dataset collected by mobile phone in natural scene is presented, which contains 10,000 images of 100 ornamental plant species in Beijing Forestry University campus. A 26-layer deep learning model consisting of 8 residual building blocks is designed for large-scale plant classification in natural environment. The proposed model achieves a recognition rate of 91.78% on the BJFU100 dataset, demonstrating that deep learning is a promising technology for smart forestry.

Deep Learning for Plant Identification in Natural Environment

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Yu Sun

2017-01-01

Full Text Available Plant image identification has become an interdisciplinary focus in both botanical taxonomy and computer vision. The first plant image dataset collected by mobile phone in natural scene is presented, which contains 10,000 images of 100 ornamental plant species in Beijing Forestry University campus. A 26-layer deep learning model consisting of 8 residual building blocks is designed for large-scale plant classification in natural environment. The proposed model achieves a recognition rate of 91.78% on the BJFU100 dataset, demonstrating that deep learning is a promising technology for smart forestry.

Effects of naturally occurring coumarins on hepatic drug-metabolizing enzymes inmice

International Nuclear Information System (INIS)

Kleiner, Heather E.; Xia, Xiaojun; Sonoda, Junichiro; Zhang, Jun; Pontius, Elizabeth; Abey, Jane; Evans, Ronald M.; Moore, David D.; DiGiovanni, John

2008-01-01

Cytochromes P450 (P450s) and glutathione S-transferases (GSTs) constitute two important enzyme families involved in carcinogen metabolism. Generally, P450s play activation or detoxifying roles while GSTs act primarily as detoxifying enzymes. We previously demonstrated that oral administration of the linear furanocoumarins, isopimpinellin and imperatorin, modulated P450 and GST activities in various tissues of mice. The purpose of the present study was to compare a broader range of naturally occurring coumarins (simple coumarins, and furanocoumarins of the linear and angular type) for their abilities to modulate hepatic drug-metabolizing enzymes when administered orally to mice. We now report that all of the different coumarins tested (coumarin, limettin, auraptene, angelicin, bergamottin, imperatorin and isopimpinellin) induced hepatic GST activities, whereas the linear furanocoumarins possessed the greatest abilities to induce hepatic P450 activities, in particular P450 2B and 3A. In both cases, this corresponded to an increase in protein expression of the enzymes. Induction of P4502B10, 3A11, and 2C9 by xenobiotics often is a result of activation of the pregnane X receptor (PXR) and/or constitutive androstane receptor (CAR). Using a pregnane X receptor reporter system, our results demonstrated that isopimpinellin activated both PXR and its human ortholog SXR by recruiting coactivator SRC-1 in transfected cells. In CAR transfection assays, isopimpinellin counteracted the inhibitory effect of androstanol on full-length mCAR, a Gal4-mCAR ligand-binding domain fusion, and restored coactivator binding. Orally administered isopimpinellin induced hepatic mRNA expression of Cyp2b10, Cyp3a11, and GSTa in CAR(+/+) wild-type mice. In contrast, the induction of Cyp2b10 mRNA by isopimpinellin was attenuated in the CAR(-/-) mice, suggesting that isopimpinellin induces Cyp2b10 via the CAR receptor. Overall, the current data indicate that naturally occurring coumarins have

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

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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.

Ferulic acid: an antioxidant found naturally in plant cell walls and feruloyl esterases involved in its release and their applications.

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Mathew, Sindhu; Abraham, T Emilia

2004-01-01

Ferulic acid is the most abundant hydroxycinnamic acid in the plant world and maize bran with 3.1% (w/w) ferulic acid is one of the most promising sources of this antioxidant. The dehydrodimers of ferulic acid are important structural components in the plant cell wall and serve to enhance its rigidity and strength. Feruloyl esterases are a subclass of the carboxylic acid esterases that hydrolyze the ester bond between hydroxycinnamic acids and sugars present in plant cell walls and they have been isolated from a wide range of microorganisms, when grown on complex substrates such as cereal brans, sugar beet pulp, pectin and xylan. These enzymes perform a function similar to alkali in the deesterification of plant cell wall and differ in their specificities towards the methyl esters of cinnamic acids and ferulolylated oligosaccharides. They act synergistically with xylanases and pectinases and facilitate the access of hydrolases to the backbone of cell wall polymers. The applications of ferulic acid and feruloyl esterase enzymes are many and varied. Ferulic acid obtained from agricultural byproducts is a potential precursor for the production of natural vanillin, due to the lower production cost.

Tracking dynamics of plant biomass composting by changes in substrate structure, microbial community, and enzyme activity

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2012-01-01

Background Understanding the dynamics of the microbial communities that, along with their secreted enzymes, are involved in the natural process of biomass composting may hold the key to breaking the major bottleneck in biomass-to-biofuels conversion technology, which is the still-costly deconstruction of polymeric biomass carbohydrates to fermentable sugars. However, the complexity of both the structure of plant biomass and its counterpart microbial degradation communities makes it difficult to investigate the composting process. Results In this study, a composter was set up with a mix of yellow poplar (Liriodendron tulipifera) wood-chips and mown lawn grass clippings (85:15 in dry-weight) and used as a model system. The microbial rDNA abundance data obtained from analyzing weekly-withdrawn composted samples suggested population-shifts from bacteria-dominated to fungus-dominated communities. Further analyses by an array of optical microscopic, transcriptional and enzyme-activity techniques yielded correlated results, suggesting that such population shifts occurred along with early removal of hemicellulose followed by attack on the consequently uncovered cellulose as the composting progressed. Conclusion The observed shifts in dominance by representative microbial groups, along with the observed different patterns in the gene expression and enzymatic activities between cellulases, hemicellulases, and ligninases during the composting process, provide new perspectives for biomass-derived biotechnology such as consolidated bioprocessing (CBP) and solid-state fermentation for the production of cellulolytic enzymes and biofuels. PMID:22490508

Carotenoid-cleavage activities of crude enzymes from Pandanous amryllifolius.

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Ningrum, Andriati; Schreiner, Matthias

2014-11-01

Carotenoid degradation products, known as norisoprenoids, are aroma-impact compounds in several plants. Pandan wangi is a common name of the shrub Pandanus amaryllifolius. The genus name 'Pandanus' is derived from the Indonesian name of the tree, pandan. In Indonesia, the leaves from the plant are used for several purposes, e.g., as natural colorants and flavor, and as traditional treatments. The aim of this study was to determine the cleavage of β-carotene and β-apo-8'-carotenal by carotenoid-cleavage enzymes isolated from pandan leaves, to investigate dependencies of the enzymatic activities on temperature and pH, to determine the enzymatic reaction products by using Headspace Solid Phase Microextraction Gas Chromatography/Mass Spectrophotometry (HS-SPME GC/MS), and to investigate the influence of heat treatment and addition of crude enzyme on formation of norisoprenoids. Crude enzymes from pandan leaves showed higher activity against β-carotene than β-apo-8'-carotenal. The optimum temperature of crude enzymes was 70°, while the optimum pH value was 6. We identified β-ionone as the major volatile reaction product from the incubations of two different carotenoid substrates, β-carotene and β-apo-8'-carotenal. Several treatments, e.g., heat treatment and addition of crude enzymes in pandan leaves contributed to the norisoprenoid content. Our findings revealed that the crude enzymes from pandan leaves with carotenoid-cleavage activity might provide a potential application, especially for biocatalysis, in natural-flavor industry. Copyright © 2014 Verlag Helvetica Chimica Acta AG, Zürich.

Regulation of sucrose metabolism in higher plants: localization and regulation of activity of key enzymes

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Winter, H.; Huber, S. C.; Brown, C. S. (Principal Investigator)

2000-01-01

Sucrose (Suc) plays a central role in plant growth and development. It is a major end product of photosynthesis and functions as a primary transport sugar and in some cases as a direct or indirect regulator of gene expression. Research during the last 2 decades has identified the pathways involved and which enzymes contribute to the control of flux. Availability of metabolites for Suc synthesis and 'demand' for products of sucrose degradation are important factors, but this review specifically focuses on the biosynthetic enzyme sucrose-phosphate synthase (SPS), and the degradative enzymes, sucrose synthase (SuSy), and the invertases. Recent progress has included the cloning of genes encoding these enzymes and the elucidation of posttranslational regulatory mechanisms. Protein phosphorylation is emerging as an important mechanism controlling SPS activity in response to various environmental and endogenous signals. In terms of Suc degradation, invertase-catalyzed hydrolysis generally has been associated with cell expansion, whereas SuSy-catalyzed metabolism has been linked with biosynthetic processes (e.g., cell wall or storage products). Recent results indicate that SuSy may be localized in multiple cellular compartments: (1) as a soluble enzyme in the cytosol (as traditionally assumed); (2) associated with the plasma membrane; and (3) associated with the actin cytoskeleton. Phosphorylation of SuSy has been shown to occur and may be one of the factors controlling localization of the enzyme. The purpose of this review is to summarize some of the recent developments relating to regulation of activity and localization of key enzymes involved in sucrose metabolism in plants.

Computational enzyme design: transitioning from catalytic proteins to enzymes.

Science.gov (United States)

Mak, Wai Shun; Siegel, Justin B

2014-08-01

The widespread interest in enzymes stem from their ability to catalyze chemical reactions under mild and ecologically friendly conditions with unparalleled catalytic proficiencies. While thousands of naturally occurring enzymes have been identified and characterized, there are still numerous important applications for which there are no biological catalysts capable of performing the desired chemical transformation. In order to engineer enzymes for which there is no natural starting point, efforts using a combination of quantum chemistry and force-field based protein molecular modeling have led to the design of novel proteins capable of catalyzing chemical reactions not catalyzed by naturally occurring enzymes. Here we discuss the current status and potential avenues to pursue as the field of computational enzyme design moves forward. Published by Elsevier Ltd.

40 CFR 174.525 - E. coli B-D-glucuronidase enzyme as a plant-incorporated protectant inert ingredient; exemption...

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 23 2010-07-01 2010-07-01 false E. coli B-D-glucuronidase enzyme as a... E. coli B-D-glucuronidase enzyme as a plant-incorporated protectant inert ingredient; exemption from the requirement of a tolerance. Residues of E. coli B-D-glucuronidase enzyme are exempt from the...

The role of carbon starvation in the induction of enzymes that degrade plant-derived carbohydrates in Aspergillus niger.

Science.gov (United States)

van Munster, Jolanda M; Daly, Paul; Delmas, Stéphane; Pullan, Steven T; Blythe, Martin J; Malla, Sunir; Kokolski, Matthew; Noltorp, Emelie C M; Wennberg, Kristin; Fetherston, Richard; Beniston, Richard; Yu, Xiaolan; Dupree, Paul; Archer, David B

2014-11-01

Fungi are an important source of enzymes for saccharification of plant polysaccharides and production of biofuels. Understanding of the regulation and induction of expression of genes encoding these enzymes is still incomplete. To explore the induction mechanism, we analysed the response of the industrially important fungus Aspergillus niger to wheat straw, with a focus on events occurring shortly after exposure to the substrate. RNA sequencing showed that the transcriptional response after 6h of exposure to wheat straw was very different from the response at 24h of exposure to the same substrate. For example, less than half of the genes encoding carbohydrate active enzymes that were induced after 24h of exposure to wheat straw, were also induced after 6h exposure. Importantly, over a third of the genes induced after 6h of exposure to wheat straw were also induced during 6h of carbon starvation, indicating that carbon starvation is probably an important factor in the early response to wheat straw. The up-regulation of the expression of a high number of genes encoding CAZymes that are active on plant-derived carbohydrates during early carbon starvation suggests that these enzymes could be involved in a scouting role during starvation, releasing inducing sugars from complex plant polysaccharides. We show, using proteomics, that carbon-starved cultures indeed release CAZymes with predicted activity on plant polysaccharides. Analysis of the enzymatic activity and the reaction products, indicates that these proteins are enzymes that can degrade various plant polysaccharides to generate both known, as well as potentially new, inducers of CAZymes. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Carnivorous Nutrition in Pitcher Plants (Nepenthes spp.) via an Unusual Complement of Endogenous Enzymes.

Science.gov (United States)

Lee, Linda; Zhang, Ye; Ozar, Brittany; Sensen, Christoph W; Schriemer, David C

2016-09-02

Plants belonging to the genus Nepenthes are carnivorous, using specialized pitfall traps called "pitchers" that attract, capture, and digest insects as a primary source of nutrients. We have used RNA sequencing to generate a cDNA library from the Nepenthes pitchers and applied it to mass spectrometry-based identification of the enzymes secreted into the pitcher fluid using a nonspecific digestion strategy superior to trypsin in this application. This first complete catalog of the pitcher fluid subproteome includes enzymes across a variety of functional classes. The most abundant proteins present in the secreted fluid are proteases, nucleases, peroxidases, chitinases, a phosphatase, and a glucanase. Nitrogen recovery involves a particularly rich complement of proteases. In addition to the two expected aspartic proteases, we discovered three novel nepenthensins, two prolyl endopeptidases that we name neprosins, and a putative serine carboxypeptidase. Additional proteins identified are relevant to pathogen-defense and secretion mechanisms. The full complement of acid-stable enzymes discovered in this study suggests that carnivory in the genus Nepenthes can be sustained by plant-based mechanisms alone and does not absolutely require bacterial symbiosis.

Some medicinal plants as natural anticancer agents

OpenAIRE

Govind Pandey; S Madhuri

2009-01-01

India is the largest producer of medicinal plants and is rightly called the "Botanical garden of the World". The medicinal plants, besides having natural therapeutic values against various diseases, also provide high quality of food and raw materials for livelihood. Considerable works have been done on these plants to treat cancer, and some plant products have been marketed as anticancer drugs, based on the traditional uses and scientific reports. These plants may promote host resistance agai...

Plant cell wall glycosyltransferases: High-throughput recombinant expression screening and general requirements for these challenging enzymes

DEFF Research Database (Denmark)

Welner, Ditte Hededam; Shin, David; Tomaleri, Giovani P.

2017-01-01

Molecular characterization of plant cell wall glycosyltransferases is a critical step towards understanding the biosynthesis of the complex plant cell wall, and ultimately for efficient engineering of biofuel and agricultural crops. The majority of these enzymes have proven very difficult to obta...

Recent Advances in Marine Enzymes for Biotechnological Processes.

Science.gov (United States)

Lima, R N; Porto, A L M

In the last decade, new trends in the food and pharmaceutical industries have increased concern for the quality and safety of products. The use of biocatalytic processes using marine enzymes has become an important and useful natural product for biotechnological applications. Bioprocesses using biocatalysts like marine enzymes (fungi, bacteria, plants, animals, algae, etc.) offer hyperthermostability, salt tolerance, barophilicity, cold adaptability, chemoselectivity, regioselectivity, and stereoselectivity. Currently, enzymatic methods are used to produce a large variety of products that humans consume, and the specific nature of the enzymes including processing under mild pH and temperature conditions result in fewer unwanted side-effects and by-products. This offers high selectivity in industrial processes. The marine habitat has been become increasingly studied because it represents a huge source potential biocatalysts. Enzymes include oxidoreductases, hydrolases, transferases, isomerases, ligases, and lyases that can be used in food and pharmaceutical applications. Finally, recent advances in biotechnological processes using enzymes of marine organisms (bacterial, fungi, algal, and sponges) are described and also our work on marine organisms from South America, especially marine-derived fungi and bacteria involved in biotransformations and biodegradation of organic compounds. © 2016 Elsevier Inc. All rights reserved.

Application of carbohydrate arrays coupled with mass spectrometry to detect activity of plant-polysaccharide degradative enzymes from the fungus Aspergillus niger.

Science.gov (United States)

van Munster, Jolanda M; Thomas, Baptiste; Riese, Michel; Davis, Adrienne L; Gray, Christopher J; Archer, David B; Flitsch, Sabine L

2017-02-21

Renewables-based biotechnology depends on enzymes to degrade plant lignocellulose to simple sugars that are converted to fuels or high-value products. Identification and characterization of such lignocellulose degradative enzymes could be fast-tracked by availability of an enzyme activity measurement method that is fast, label-free, uses minimal resources and allows direct identification of generated products. We developed such a method by applying carbohydrate arrays coupled with MALDI-ToF mass spectrometry to identify reaction products of carbohydrate active enzymes (CAZymes) of the filamentous fungus Aspergillus niger. We describe the production and characterization of plant polysaccharide-derived oligosaccharides and their attachment to hydrophobic self-assembling monolayers on a gold target. We verify effectiveness of this array for detecting exo- and endo-acting glycoside hydrolase activity using commercial enzymes, and demonstrate how this platform is suitable for detection of enzyme activity in relevant biological samples, the culture filtrate of A. niger grown on wheat straw. In conclusion, this versatile method is broadly applicable in screening and characterisation of activity of CAZymes, such as fungal enzymes for plant lignocellulose degradation with relevance to biotechnological applications as biofuel production, the food and animal feed industry.

Plant nucleoside 5'-phosphoramidate hydrolase; simple purification from yellow lupin (Lupinus luteus) seeds and properties of homogeneous enzyme.

Science.gov (United States)

Guranowski, Andrzej; Wojdyła, Anna M; Rydzik, Anna M; Stepiński, Janusz; Jemielity, Jacek

2011-01-01

Adenosine 5'-phosphoramidate (NH₂-pA) is an uncommon natural nucleotide of poorly understood biochemistry and function. We studied a plant enzyme potentially involved in the catabolism of NH₂-pA. A fast and simple method comprising extraction of yellow lupin (Lupinus luteus) seed-meal with a low ionic strength buffer, ammonium sulfate and acetone fractionations, removal of contaminating proteins by heat denaturation, and affinity chromatography on AMP-agarose, yielded homogenous nucleoside 5'-phosphoramidase. Mass spectrometric analysis showed that the lupin hydrolase exhibits closest similarity to Arabidopsis thaliana Hint1 protein. The substrate specificity of the lupin enzyme, in particular its ability to split the P-S bond in adenosine 5'-phosphorothioate, is typical of known Hint1 proteins. Adenosine 5'-phosphofluoride and various derivatives of guanosine 5'-phosphoramidate were also substrates. Neither common divalent metal cations nor 10 mM EDTA or EGTA affected the hydrolysis of NH₂-pA. The enzyme functions as a homodimer (2 x 15,800 Da). At the optimum pH of 7.0, the K(m) for NH₂-pA was 0.5 µM and k(cat) 0.8 s⁻¹ (per monomer active site). The properties of the lupin nucleoside 5'-phosphoramidase are compared with those of its counterparts from other organisms.

Fungal enzyme production in seeds of transgenic canola plants for conversion of cellulosic materials to ethanol

Energy Technology Data Exchange (ETDEWEB)

Cheng, K.J.; Beauchemin, K.A. [Agriculture and Agri-Food Canada, Lethbridge, AB (Canada); Moloney, M.M. [Calgary Univ., AB (Canada). Dept. of Biological Sciences

1997-07-01

The fuel alcohol industry makes use of industrial enzymes to effectively degrade fibrous plant cell walls. Carbohydrates in cellulosic materials are in the form of complex sugars that can be hydrolyzed to simple sugars by fungal fibrolytic enzymes such as cellulases and xylanases. This study was conducted to find a cost effective way to produce fibrolytic enzymes using gene fusion technology in which a xylanase gene and a cellulase gene from two fungal species are introduced into canola to be a carrier for the production of these enzymes. The two genes had been analyzed for maximal enzymatic activity to minimize side effects. Results of the study demonstrated the stability and potential of transgenic oil-bodies as an immobilized enzyme matrix, and showed that it is possible to express fibrolytic enzymes in canola.

Enzyme inhibitory and antioxidant activities of traditional medicinal plants: Potential application in the management of hyperglycemia

Directory of Open Access Journals (Sweden)

Gulati Vandana

2012-06-01

Full Text Available Abstract Background Traditional Indian and Australian medicinal plant extracts were investigated to determine their therapeutic potential to inhibit key enzymes in carbohydrate metabolism, which has relevance to the management of hyperglycemia and type 2 diabetes. The antioxidant activities were also assessed. Methods The evaluation of enzyme inhibitory activity of seven Australian aboriginal medicinal plants and five Indian Ayurvedic plants was carried out against α-amylase and α-glucosidase. Antioxidant activity was determined by measuring (i the scavenging effect of plant extracts against 2, 2-diphenyl-1-picryl hydrazyl (DPPH and 2, 2′-azinobis-3-ethylbenzothiazoline-6-sulfonate (ABTS and (ii ferric reducing power. Total phenolic and total flavonoid contents were also determined. Results Of the twelve plant extracts evaluated, the highest inhibitory activity against both α-amylase and α-glucosidase enzymes was exerted by Santalum spicatum and Pterocarpus marsupium with IC50 values of 5.43 μg/ml and 0.9 μg/ml, respectively, and 5.16 μg/ml and 1.06 μg/ml, respectively. However, the extracts of Acacia ligulata (IC50 = 1.01 μg/ml, Beyeria leshnaultii (0.39 μg/ml, Mucuna pruriens (0.8 μg/ml and Boerhaavia diffusa (1.72 μg/ml exhibited considerable activity against α-glucosidase enzyme only. The free radical scavenging activity was found to be prominent in extracts of Acacia kempeana, Acacia ligulata followed by Euphorbia drummondii against both DPPH and ABTS. The reducing power was more pronounced in Euphorbia drummondii and Pterocarpus marsupium extracts. The phenolic and flavonoid contents ranged from 0.42 to 30.27 μg/mg equivalent of gallic acid and 0.51 to 32.94 μg/mg equivalent of quercetin, respectively, in all plant extracts. Pearson’s correlation coefficient between total flavonoids and total phenolics was 0.796. Conclusion The results obtained in this study showed that most of the plant extracts

Effect of different nutrient supply and other growth factors on the activity of the oxidizing enzymes in plants

Energy Technology Data Exchange (ETDEWEB)

Amberger, A

1960-01-01

Among the plants studied were french beans and peas; the oxidizing enzymes examined were ascorbic acid oxidase, cytochrome oxidase, phenol oxidase, peroxidase and catalase. Increasing the K dosage reduced enzyme activity and raised dry matter contents until at a very high dosage this action was reversed. Both N and P increased enzyme activity and yields. With B high enzyme activity and low dry matter content were both associated with deficiency and toxicity levels. Increasing the Fe dosage led to a rise in both dry matter content and enzyme activity, whereas F depressed yields and raised enzyme activity. Lack of water increased respiration. Light inhibited all enzyme activity.

Flavonoids as modulators of metabolic enzymes and drug transporters.

Science.gov (United States)

Miron, Anca; Aprotosoaie, Ana Clara; Trifan, Adriana; Xiao, Jianbo

2017-06-01

Flavonoids, natural compounds found in plants and in plant-derived foods and beverages, have been extensively studied with regard to their capacity to modulate metabolic enzymes and drug transporters. In vitro, flavonoids predominantly inhibit the major phase I drug-metabolizing enzyme CYP450 3A4 and the enzymes responsible for the bioactivation of procarcinogens (CYP1 enzymes) and upregulate the enzymes involved in carcinogen detoxification (UDP-glucuronosyltransferases, glutathione S-transferases (GSTs)). Flavonoids have been reported to inhibit ATP-binding cassette (ABC) transporters (multidrug resistance (MDR)-associated proteins, breast cancer-resistance protein) that contribute to the development of MDR. P-glycoprotein, an ABC transporter that limits drug bioavailability and also induces MDR, was differently modulated by flavonoids. Flavonoids and their phase II metabolites (sulfates, glucuronides) inhibit organic anion transporters involved in the tubular uptake of nephrotoxic compounds. In vivo studies have partially confirmed in vitro findings, suggesting that the mechanisms underlying the modulatory effects of flavonoids are complex and difficult to predict in vivo. Data summarized in this review strongly support the view that flavonoids are promising candidates for the enhancement of oral drug bioavailability, chemoprevention, and reversal of MDR. © 2017 New York Academy of Sciences.

Natural products – learning chemistry from plants

NARCIS (Netherlands)

Staniek, A.; Bouwmeester, H.J.; Fraser, P.D.; Kayser, O.; Martens, S.; Tissier, A.; Krol, van der A.R.; Wessjohann, L.; Warzecha, H.

2014-01-01

Plant natural products (PNPs) are unique in that they represent a vast array of different structural features, ranging from relatively simple molecules to very complex ones. Given the fact that many plant secondary metabolites exhibit profound biological activity, they are frequently used as

Hydrolytic enzymes in the central vacuole of plant cells.

Science.gov (United States)

Boller, T; Kende, H

1979-06-01

The hydrolase content of vacuoles isolated from protoplasts of suspension-cultured tobacco cells, of tulip petals, and of pineapple leaves, and the sedimentation behavior of tobacco tonoplasts were studied. Three precautions were found to be important for the analysis of vacuolar hydrolases and of the tonoplast. (a) Purification of protoplasts in a Ficoll gradient was necessary to remove cell debris which contained contaminating hydrolases adsorbed from the fungal cell-wall-degrading enzyme preparation. (b) Hydrolase activities in the homogenates of the intact cells or the tissue used and of the purified protoplasts had to be compared to verify the absence of contaminating hydrolases in the protoplast preparation. (c) Vacuoles obtained from the protoplasts by an osmotic shock had to be purified from the lysate in a Ficoll gradient. Since the density of the central vacuole approximates that of the protoplasts, about a 10% contamination of the vacuolar preparation by surviving protoplasts could not be eliminated and had to be taken into account when the distribution of enzymes and of radioactivity was calculated.THE INTRACELLULAR ACTIVITIES OF THE FOLLOWING ACID HYDROLASES WERE PRIMARILY LOCALIZED IN THE VACUOLE OF TOBACCO CELLS: alpha-mannosidase, beta-N-acetylglucosaminidase, beta-fructosidase, nuclease, phosphatase, phosphodiesterase. A similar composition of acid hydrolases was found in vacuoles obtained from protoplasts of tulip petals. Proteinase, a hydrolase with low activity in tobacco cells and tulip petals and therefore difficult to localize unequivocally, was found to be vacuolar in pineapple leaves, a tissue containing high levels of this enzyme. Our data support the hypothesis that the central vacuole of higher plant cells has an enzyme composition analogous to that of the animal lysosome.None of the vacuolar enzymes investigated was found to be bound to the tonoplast. When vacuoles were isolated from cells labeled with radioactive choline, the vacuolar

Tracking dynamics of plant biomass composting by changes in substrate structure, microbial community, and enzyme activity

Directory of Open Access Journals (Sweden)

Wei Hui

2012-04-01

Full Text Available Abstract Background Understanding the dynamics of the microbial communities that, along with their secreted enzymes, are involved in the natural process of biomass composting may hold the key to breaking the major bottleneck in biomass-to-biofuels conversion technology, which is the still-costly deconstruction of polymeric biomass carbohydrates to fermentable sugars. However, the complexity of both the structure of plant biomass and its counterpart microbial degradation communities makes it difficult to investigate the composting process. Results In this study, a composter was set up with a mix of yellow poplar (Liriodendron tulipifera wood-chips and mown lawn grass clippings (85:15 in dry-weight and used as a model system. The microbial rDNA abundance data obtained from analyzing weekly-withdrawn composted samples suggested population-shifts from bacteria-dominated to fungus-dominated communities. Further analyses by an array of optical microscopic, transcriptional and enzyme-activity techniques yielded correlated results, suggesting that such population shifts occurred along with early removal of hemicellulose followed by attack on the consequently uncovered cellulose as the composting progressed. Conclusion The observed shifts in dominance by representative microbial groups, along with the observed different patterns in the gene expression and enzymatic activities between cellulases, hemicellulases, and ligninases during the composting process, provide new perspectives for biomass-derived biotechnology such as consolidated bioprocessing (CBP and solid-state fermentation for the production of cellulolytic enzymes and biofuels.

Inhibition and kinetic studies of cellulose- and hemicellulose-degrading enzymes of Ganoderma boninense by naturally occurring phenolic compounds.

Science.gov (United States)

Surendran, A; Siddiqui, Y; Ali, N S; Manickam, S

2018-06-01

Ganoderma sp, the causal pathogen of the basal stem rot (BSR) disease of oil palm, secretes extracellular hydrolytic enzymes. These play an important role in the pathogenesis of BSR by nourishing the pathogen through the digestion of cellulose and hemicellulose of the host tissue. Active suppression of hydrolytic enzymes secreted by Ganoderma boninense by various naturally occurring phenolic compounds and estimation of their efficacy on pathogen suppression is focused in this study. Ten naturally occurring phenolic compounds were assessed for their inhibitory effect on the hydrolytic enzymes of G. boninense. The enzyme kinetics (V max and K m ) and the stability of the hydrolytic enzymes were also characterized. The selected compounds had shown inhibitory effect at various concentrations. Two types of inhibitions namely uncompetitive and noncompetitive were observed in the presence of phenolic compounds. Among all the phenolic compounds tested, benzoic acid was the most effective compound suppressive to the growth and production of hydrolytic enzymes secreted by G. boninense. The phenolic compounds as inhibitory agents can be a better replacement for the metal ions which are known as conventional inhibitors till date. The three hydrolytic enzymes were stable in a wide range of pH and temperature. These findings highlight the efficacy of the applications of phenolic compounds to control Ganoderma. The study has proved a replacement for chemical controls of G. boninense with naturally occurring phenolic compounds. © 2018 The Society for Applied Microbiology.

Glycosylation Helps Cellulase Enzymes Bind to Plant Cell Walls (Fact Sheet)

Energy Technology Data Exchange (ETDEWEB)

2012-06-01

Computer simulations suggest a new strategy to design enhanced enzymes for biofuels production. Large-scale computer simulations predict that the addition of glycosylation on carbohydrate-binding modules can dramatically improve the binding affinity of these protein domains over amino acid mutations alone. These simulations suggest that glycosylation can be used as a protein engineering tool to enhance the activity of cellulase enzymes, which are a key component in the conversion of cellulose to soluble sugars in the production of biofuels. Glycosylation is the covalent attachment of carbohydrate molecules to protein side chains, and is present in many proteins across all kingdoms of life. Moreover, glycosylation is known to serve a wide variety of functions in biological recognition, cell signaling, and metabolism. Cellulase enzymes, which are responsible for deconstructing cellulose found in plant cell walls to glucose, contain glycosylation that when modified can affect enzymatic activity-often in an unpredictable manner. To gain insight into the role of glycosylation on cellulase activity, scientists at the National Renewable Energy Laboratory (NREL) used computer simulation to predict that adding glycosylation on the carbohydrate-binding module of a cellulase enzyme dramatically boosts the binding affinity to cellulose-more than standard protein engineering approaches in which amino acids are mutated. Because it is known that higher binding affinity in cellulases leads to higher activity, this work suggests a new route to designing enhanced enzymes for biofuels production. More generally, this work suggests that tuning glycosylation in cellulase enzymes is a key factor to consider when engineering biochemical conversion processes, and that more work is needed to understand how glycosylation affects cellulase activity at the molecular level.

Nanomaterials with enzyme-like characteristics (nanozymes): next-generation artificial enzymes.

Science.gov (United States)

Wei, Hui; Wang, Erkang

2013-07-21

Over the past few decades, researchers have established artificial enzymes as highly stable and low-cost alternatives to natural enzymes in a wide range of applications. A variety of materials including cyclodextrins, metal complexes, porphyrins, polymers, dendrimers and biomolecules have been extensively explored to mimic the structures and functions of naturally occurring enzymes. Recently, some nanomaterials have been found to exhibit unexpected enzyme-like activities, and great advances have been made in this area due to the tremendous progress in nano-research and the unique characteristics of nanomaterials. To highlight the progress in the field of nanomaterial-based artificial enzymes (nanozymes), this review discusses various nanomaterials that have been explored to mimic different kinds of enzymes. We cover their kinetics, mechanisms and applications in numerous fields, from biosensing and immunoassays, to stem cell growth and pollutant removal. We also summarize several approaches to tune the activities of nanozymes. Finally, we make comparisons between nanozymes and other catalytic materials (other artificial enzymes, natural enzymes, organic catalysts and nanomaterial-based catalysts) and address the current challenges and future directions (302 references).

Curious Cases of the Enzymes.

Science.gov (United States)

Ulusu, Nuriye Nuray

2015-07-01

Life as we know it heavily relies on biological catalysis, in fact, in a very nonromantic version of it, life could be considered as a series of chemical reactions, regulated by the guarding principles of thermodynamics. In ancient times, a beating heart was a good sign of vitality, however, to me, it is actually the presence of active enzymes that counts… Though we do not usually pay attention, the history of enzymology is as old as humanity itself, and dates back to the ancient times. This paper is dedicated to these early moments of this remarkable science that touched our lives in the past and will make life a lot more efficient for humanity in the future. There was almost always a delicate, fundamentally essential relationship between mankind and the enzymes. Challenged by a very alien and hostile Nature full of predators, prehistoric men soon discovered the medicinal properties of the plants, through trial and error. In fact, they accidently discovered the enzyme inhibitors and thus, in crude terms, kindled a sparkling area of research. These plant-derivatives that acted as enzyme inhibitors helped prehistoric men in their pursuit of survival and protection from predators; in hunting and fishing… Later in history, while the underlying purposes of survival and increasing the quality of life stayed intact, the ways and means of enzymology experienced a massive transformation, as the 'trial and error' methodology of the ancients is now replaced with rational scientific theories.

Natural occurrence of mycotoxins in medicinal plants: a review.

Science.gov (United States)

Ashiq, Samina; Hussain, Mubbashir; Ahmad, Bashir

2014-05-01

Medicinal plants are widely used as home remedies and raw materials for the pharmaceutical industries. Herbal remedies are used in the prevention, treatment and cure of disorders and diseases since ancient times. However, use of medicinal herbs may not meet the requirements of quality, safety and efficacy. During harvesting, handling, storage and distribution, medicinal plants are subjected to contamination by various fungi, which may be responsible for spoilage and production of mycotoxins. The increasing consumption of medicinal plants has made their use a public health problem due to the lack of effective surveillance of the use, efficacy, toxicity and quality of these natural products. The increase in use of medicinal plants may lead to an increase in the intake of mycotoxins therefore contamination of medicinal plants with mycotoxins can contribute to adverse human health problems and therefore represents a special hazard. Numerous natural occurrences of mycotoxins in medicinal plants and traditional herbal medicines have been reported from various countries including Spain, China, Germany, India, Turkey and from Middle East as well. This review discusses the important mycotoxins and their natural occurrences in medicinal plants and their products. Copyright © 2014 Elsevier Inc. All rights reserved.

SCADA Architecture for Natural Gas plant

Directory of Open Access Journals (Sweden)

Turc Traian

2009-12-01

Full Text Available The paper describes the Natural Gas Plant SCADA architecture. The main purpose of SCADA system is remote monitoring and controlling of any industrial plant. The SCADA hardware architecture is based on multi-dropping system allowing connecting a large number of different fiels devices. The SCADA Server gathers data from gas plant and stores data to a MtSQL database. The SCADA server is connected to other SCADA client application offers a intuitive and user-friendly HMI. The main benefit of using SCADA is real time displaying of gas plant state. The main contriobution of the authors consists in designing SCADA architecture based on multi-dropping system and Human Machine Interface.

Effect of Rhizosphere Enzymes on Phytoremediation in PAH-Contaminated Soil Using Five Plant Species

Science.gov (United States)

Liu, Rui; Dai, Yuanyuan; Sun, Libo

2015-01-01

A pot experiment was performed to study the effectiveness of remediation using different plant species and the enzyme response involved in remediating PAH-contaminated soil. The study indicated that species Echinacea purpurea, Festuca arundinacea Schred, Fire Phoenix (a combined F. arundinacea), and Medicago sativa L. possess the potential for remediation in PAH-contaminated soils. The study also determined that enzymatic reactions of polyphenol oxidase (except Fire Phoenix), dehydrogenase (except Fire Phoenix), and urease (except Medicago sativa L.) were more prominent over cultivation periods of 60d and 120d than 150d. Urease activity of the tested species exhibited prominently linear negative correlations with alkali-hydrolyzable nitrogen content after the tested plants were cultivated for 150d (R2 = 0.9592). The experiment also indicated that alkaline phosphatase activity in four of the five tested species (Echinacea purpurea, Callistephus chinensis, Festuca arundinacea Schred and Fire Phoenix) was inhibited during the cultivation process (at 60d and 120d). At the same time, the study determined that the linear relationship between alkaline phosphatase activity and effective phosphorus content in plant rhizosphere soil exhibited a negative correlation after a growing period of 120d (R2 = 0.665). Phytoremediation of organic contaminants in the soil was closely related to specific characteristics of particular plant species, and the catalyzed reactions were the result of the action of multiple enzymes in the plant rhizosphere soil. PMID:25822167

Resolving the role of plant glutamate dehydrogenase: II. Physiological characterization of plants overexpressing the two enzyme subunits individually or simultaneously.

Science.gov (United States)

Tercé-Laforgue, Thérèse; Bedu, Magali; Dargel-Grafin, Céline; Dubois, Frédéric; Gibon, Yves; Restivo, Francesco M; Hirel, Bertrand

2013-10-01

Glutamate dehydrogenase (GDH; EC 1.4.1.2) is able to carry out the deamination of glutamate in higher plants. In order to obtain a better understanding of the physiological function of GDH in leaves, transgenic tobacco (Nicotiana tabacum L.) plants were constructed that overexpress two genes from Nicotiana plumbaginifolia (GDHA and GDHB under the control of the Cauliflower mosiac virus 35S promoter), which encode the α- and β-subunits of GDH individually or simultaneously. In the transgenic plants, the GDH protein accumulated in the mitochondria of mesophyll cells and in the mitochondria of the phloem companion cells (CCs), where the native enzyme is normally expressed. Such a shift in the cellular location of the GDH enzyme induced major changes in carbon and nitrogen metabolite accumulation and a reduction in growth. These changes were mainly characterized by a decrease in the amount of sucrose, starch and glutamine in the leaves, which was accompanied by an increase in the amount of nitrate and Chl. In addition, there was an increase in the content of asparagine and a decrease in proline. Such changes may explain the lower plant biomass determined in the GDH-overexpressing lines. Overexpressing the two genes GDHA and GDHB individually or simultaneously induced a differential accumulation of glutamate and glutamine and a modification of the glutamate to glutamine ratio. The impact of the metabolic changes occurring in the different types of GDH-overexpressing plants is discussed in relation to the possible physiological function of each subunit when present in the form of homohexamers or heterohexamers.

Gene expression and activity of antioxidant enzymes in rice plants, cv. BRS AG, under saline stress.

Science.gov (United States)

Rossatto, Tatiana; do Amaral, Marcelo Nogueira; Benitez, Letícia Carvalho; Vighi, Isabel Lopes; Braga, Eugenia Jacira Bolacel; de Magalhães Júnior, Ariano Martins; Maia, Mara Andrade Colares; da Silva Pinto, Luciano

2017-10-01

The rice cultivar ( Oryza sativa L.) BRS AG, developed by Embrapa Clima Temperado, is the first cultivar designed for purposes other than human consumption. It may be used in ethanol production and animal feed. Different abiotic stresses negatively affect plant growth. Soil salinity is responsible for a serious reduction in productivity. Therefore, the objective of this study was to evaluate the gene expression and the activity of antioxidant enzymes (SOD, CAT, APX and GR) and identify their functions in controlling ROS levels in rice plants, cultivar BRS AG, after a saline stress period. The plants were grown in vitro with two NaCl concentrations (0 and 136 mM), collected at 10, 15 and 20 days of cultivation. The results indicated that the activity of the enzymes evaluated promotes protection against oxidative stress. Although, there was an increase of reactive oxygen species, there was no increase in MDA levels. Regarding genes encoding isoforms of antioxidant enzymes, it was observed that OsSOD3 - CU/Zn , OsSOD2 - Cu/Zn , OsSOD - Cu/Zn , OsSOD4 - Cu/Zn , OsSODCc1 - Cu/Zn , OsSOD - Fe , OsAPX1 , OsCATB and OsGR2 were the most responsive. The increase in the transcription of all genes among evaluated isoforms, except for OsAPX6 , which remained stable, contributed to the increase or the maintenance of enzyme activity. Thus, it is possible to infer that the cv. BRS AG has defense mechanisms against salt stress.

Conversion of nuclear power plants into natural gas plant: dismaking the disinformation

International Nuclear Information System (INIS)

Lima Porto, M.S.P. de.

1990-05-01

This work was presented by the Brasilian Nuclear Energy Association - ABEN during the meeting of May 9th of the GT Pronen-Grupo de trabalho do Programa Nacional de Energia Nuclear created by the decret 99194 of March 27, 90. The political subject named convertion of nuclear power plants into natural gas plants is analysed. The conclusion calls for the total technical impossibility of such 'convertion'. The term reconstruction is sugested in substitution to the term convertion. Complete and actual data with figures of the reconstruction, in USA, of the Midland units I and II is presented. The case of Montalto Di Castro plant, in Italy, where no work at all was performed is analysed. Considerations concerning the use of natural gas in the brasilian energy matrix is also presented. (author)

Assessment of the effect of silicon on antioxidant enzymes in cotton plants by multivariate analysis.

Science.gov (United States)

Alberto Moldes, Carlos; Fontão de Lima Filho, Oscar; Manuel Camiña, José; Gabriela Kiriachek, Soraya; Lia Molas, María; Mui Tsai, Siu

2013-11-27

Silicon has been extensively researched in relation to the response of plants to biotic and abiotic stress, as an element triggering defense mechanisms which activate the antioxidant system. Furthermore, in some species, adding silicon to unstressed plants modifies the activity of certain antioxidant enzymes participating in detoxifying processes. Thus, in this study, we analyzed the activity of antioxidant enzymes in leaves and roots of unstressed cotton plants fertilized with silicon (Si). Cotton plants were grown in hydroponic culture and added with increasing doses of potassium silicate; then, the enzymatic activity of catalase (CAT), guaiacol peroxidase (GPOX), ascorbate peroxidase (APX), and lipid peroxidation were determined. Using multivariate analysis, we found that silicon altered the activity of GPOX, APX, and CAT in roots and leaves of unstressed cotton plants, whereas lipid peroxidation was not affected. The analysis of these four variables in concert showed a clear differentiation among Si treatments. We observed that enzymatic activities in leaves and roots changed as silicon concentration increased, to stabilize at 100 and 200 mg Si L(-1) treatments in leaves and roots, respectively. Those alterations would allow a new biochemical status that could be partially responsible for the beneficial effects of silicon. This study might contribute to adjust the silicon application doses for optimal fertilization, preventing potential toxic effects and unnecessary cost.

EFFECT OF NATURAL PLANT EXTRACTS ON PORCINE OVARIAN FUNCTIONS

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Attila Kádasi

2015-02-01

Full Text Available This report provides information about the impact of chosen natural plant extracts on basic ovarian functions. This article summarizes our results concerning the effect of selected plant extracts on proliferation, apoptosis and hormone secretion – release of progesterone (P4, testosterone (T and leptin (L on porcine granulosa cells (GC, We analyzed effects of ginkgo (GB, rooibos (RB, flaxseed (FL, green tea polyphenols (GTPP, green tea - epigallocatechin-3-gallate (EGCG, resveratrol (RSV and curcumin (CURC (0; 1; 10 and 100 μg.ml-1 on markers of proliferation, apoptosis and secretory activity of porcine ovarian granulosa cells by using immunocytochemistry and EIA. It was demonstrated, that all these natural plants and plant molecules inhibited the accumulation of proliferation-related peptide (PCNA and apoptosis-associated peptide (Bax in cultured. Furthermore, it was observed that natural plant extracts altered progesterone, testosterone and leptin release in porcine ovarian cells. It is concluded, that GB, RB, FL, RSV, CURC, GTPP and EGCG can directly affect ovarian cells and therefore they could potentially influence ovarian functions.

Nitrilase enzymes and their role in plant–microbe interactions

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Howden, Andrew J. M.; Preston, Gail M.

2009-01-01

Summary Nitrilase enzymes (nitrilases) catalyse the hydrolysis of nitrile compounds to the corresponding carboxylic acid and ammonia, and have a wide range of industrial and biotechnological applications, including the synthesis of industrially important carboxylic acids and bioremediation of cyanide and toxic nitriles. Nitrilases are produced by a wide range of organisms, including plants, bacteria and fungi, but despite their biotechnological importance, the role of these enzymes in living organisms is relatively underexplored. Current research suggests that nitrilases play important roles in a range of biological processes. In the context of plant–microbe interactions they may have roles in hormone synthesis, nutrient assimilation and detoxification of exogenous and endogenous nitriles. Nitrilases are produced by both plant pathogenic and plant growth‐promoting microorganisms, and their activities may have a significant impact on the outcome of plant–microbe interactions. In this paper we review current knowledge of the role of nitriles and nitrilases in plants and plant‐associated microorganisms, and discuss how greater understanding of the natural functions of nitrilases could be applied to benefit both industry and agriculture. PMID:21255276

Plant diversity associated with pools in natural and restored peatlands

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N. Fontaine

2007-06-01

Full Text Available This study describes plant assemblages associated with the edges of peatland pools. We conducted inventories in six natural peatlands in the province of Québec (Canada in order to measure the contribution of pools to species diversity in climatic regions where peatlands are used for peat extraction. We also carried out vegetation surveys in a peatland that has been restored after peat extraction/harvesting to determine whether pool vegetation establishes along the edges of created pools when dry surface restoration techniques only are used. Pools enhanced plant species richness in natural peatlands. Around created pools, species associated with natural pools were still absent, and non-bog species were present, six years after restoration. On this basis, we emphasise the importance of preserving natural peatlands with pools. In order to restore fully the plant diversity associated with peatlands at harvested sites, it may be necessary to modify pool excavation techniques so that created pools resemble more closely those in natural peatlands. Active introduction of the plant species or communities associated with natural pools may also be needed; candidate species for North America include Andromeda glaucophylla, Cladopodiella fluitans, Carex limosa, Eriophorum virginicum, Rhynchospora alba and Sphagnum cuspidatum.

Isolation and enzyme bioprospection of endophytic bacteria associated with plants of Brazilian mangrove ecosystem.

Science.gov (United States)

Castro, Renata A; Quecine, Maria Carolina; Lacava, Paulo T; Batista, Bruna D; Luvizotto, Danice M; Marcon, Joelma; Ferreira, Anderson; Melo, Itamar S; Azevedo, João L

2014-01-01

The mangrove ecosystem is a coastal tropical biome located in the transition zone between land and sea that is characterized by periodic flooding, which confers unique and specific environmental conditions on this biome. In these ecosystems, the vegetation is dominated by a particular group of plant species that provide a unique environment harboring diverse groups of microorganisms, including the endophytic microorganisms that are the focus of this study. Because of their intimate association with plants, endophytic microorganisms could be explored for biotechnologically significant products, such as enzymes, proteins, antibiotics and others. Here, we isolated endophytic microorganisms from two mangrove species, Rhizophora mangle and Avicennia nitida, that are found in streams in two mangrove systems in Bertioga and Cananéia, Brazil. Bacillus was the most frequently isolated genus, comprising 42% of the species isolated from Cananéia and 28% of the species from Bertioga. However, other common endophytic genera such as Pantoea, Curtobacterium and Enterobacter were also found. After identifying the isolates, the bacterial communities were evaluated for enzyme production. Protease activity was observed in 75% of the isolates, while endoglucanase activity occurred in 62% of the isolates. Bacillus showed the highest activity rates for amylase and esterase and endoglucanase. To our knowledge, this is the first reported diversity analysis performed on endophytic bacteria obtained from the branches of mangrove trees and the first overview of the specific enzymes produced by different bacterial genera. This work contributes to our knowledge of the microorganisms and enzymes present in mangrove ecosystems.

Natural radioactivity levels of some medical plants used in Ghana

International Nuclear Information System (INIS)

Tettey-Larbi, L.

2012-07-01

The presence of natural radioactivity in plants constitutes pathway of exposure to human via the food chain. The natural radioactivity concentrations in some selected medicinal plants used in Ghana from the Centre for Scientific Research into Plant Medicine were investigated to determine the activity concentration and the annual committed effective dose due to primodial radionuclide series of 238 U, 232 Th, and the non-serial 40 K. The plants were sampled based on their therapeutic purposes for which they are commonly used. The activity concentration was determined using gamma spectrometry. The results of the analysis indicated an average activity concentration of 238 U, 232 Th, and 40 K in the medicinal plants to be 31.78±2.80 Bq kg -1 , 56.16±2.32 Bq kg -1 and 839.80±11.86 Bq kg -1 respectively. Khaya ivorensis recorded the highest concerntration of 238 U and 232 Th while Lippia multiflora recorded the highest concentration of 40 K. The total annual committed effective doses due to 238 U, 232 Th, and 40 K in medicinal plant samples ranged from 0.026±0.001 to 0.042±0.002 mSv a -1 with an average value of 0.035±001 mSv a -1 . The average annual committed effective dose due to ingestion of the natural radionuclides in the medicinal plant samples were far below the world average annual effective dose of 0.3 mSv a -1 for ingestion of natural radionuclide provided in UNSCEAR 2000 report. Therefore, the radiological hazard associated with intake of the natural radionuclides in the medicinal plants is insignificant. (author)

Genomic characterization of plant cell wall degrading enzymes and in silico analysis of xylanses and polygalacturonases of Fusarium virguliforme

Science.gov (United States)

Plant cell wall degrading enzymes (PCWDEs) are important effectors for plant pathogens to invade plants. In this study, the composition of PCWDEs in Fusarium virguliforme that were grown for 5-days and 20 days in liquid medium was determined by RNA-Seq. Differential expression analysis showed more P...

Tolerance of plants to air pollutants. Shokubutsu no taiki osen taisei

Energy Technology Data Exchange (ETDEWEB)

Kondo, N.; Saji, H. (National Institute for Environmental Studies, Tsukuba (Japan))

1992-11-10

Attempts have been made to improve tolerance of plants to air pollutants by changing activities in detoxifying enzymes against toxic substances attributable to air pollutants, through gene manipulation. An air pollutant, absorbed in a plant through its stomata, produces toxic substances in the cells and damages the organism. Detailed discussions were given on the following: Stoma opening action and reaction; injuries attributable to air pollutants and detoxifying metabolism systems; ethylene and toxic enzymes of secondary toxic substances in an organism; different detoxifying mechanisms and active enzymes; and activation of detoxifying enzymes using genes. Pollution tolerance in plants is governed by inherent plant natures and environmental conditions. Plants that have two opposing functions of emerging damages from toxicity and preventing them with detoxifying capability are controlled with a complex and delicate balance. Changing pollution tolerance in plants may be possible by manipulating genes, but the importance is to elucidate what the tolerating enzymes are, and obtain their genes. Genes that could be used are very few in number. Expectations are placed on the future development. 122 refs., 4 figs.

The transport of natural radionuclides from soil to plants

International Nuclear Information System (INIS)

Bikit, I.; Conkic, Lj.; Slivka, J.; Krmar, M.

1995-01-01

The transport and accumulation processes of Ra-226, U-238, Th-232 and K-40 from soil to plants have been studied. Plant samples with consumable parts grown below surface have been bred in natural conditions on soil with enhanced levels of natural radioactivity (barren soil of the uranium mine Gabrovnica-Kalna). An intensive transport of heavy natural radionuclides from soil to the roots was established. The transfer factors for U-238 and Ra-226 have been much bigger than for Th-232. The most intensive uptake was registered for beet root. (author)

Exploring the functional significance of sterol glycosyltransferase enzymes.

Science.gov (United States)

Singh, Gaurav; Dhar, Yogeshwar Vikram; Asif, Mehar Hasan; Misra, Pratibha

2018-01-01

Steroidal alkaloids (SAs) are widely synthesized and distributed in plants manifesting as natural produce endowed with potential for medicinal, pesticidal and other high-value usages. Glycosylation of these SAs raises complex and diverse glycosides in plant cells that indeed govern numerous functional aspects. During the glycosylation process of these valuable metabolites, the addition of carbohydrate molecule(s) is catalyzed by enzymes known as sterol glycosyltransferases (SGTs), commonly referred to as UGTs, leading to the production of steryl glycosides (SGs). The ratio of SGs and nonglyco-conjugated SAs are different in different plant species, however, their biosynthesis in the cell is controlled by different environmental factors. The aim of this review is to evaluate the current SGT enzyme research and the functional consequences of glycomodification of SAs on the physiology and plant development, which together are associated with the plant's primary processes. Pharmaceutical, industrial, and other potential uses of saponins have also been discussed and their use in therapeutics has been unveiled by in silico analysis. The field of biotransformation or conversion of nonglycosylated to glycosylated phytosterols by the activity of SGTs, making them soluble, available and more useful for humankind is the new field of interest towards drug therapy. Copyright © 2017 Elsevier Ltd. All rights reserved.

Xenobiotic-metabolizing enzymes in plants and their role in uptake and biotransformation of veterinary drugs in the environment.

Science.gov (United States)

Bártíková, Hana; Skálová, Lenka; Stuchlíková, Lucie; Vokřál, Ivan; Vaněk, Tomáš; Podlipná, Radka

2015-08-01

Many various xenobiotics permanently enter plants and represent potential danger for their organism. For that reason, plants have evolved extremely sophisticated detoxification systems including a battery of xenobiotic-metabolizing enzymes. Some of them are similar to those in humans and animals, but there are several plant-specific ones. This review briefly introduces xenobiotic-metabolizing enzymes in plants and summarizes present information about their action toward veterinary drugs. Veterinary drugs are used worldwide to treat diseases and protect animal health. However, veterinary drugs are also unwantedly introduced into environment mostly via animal excrements, they persist in the environment for a long time and may impact on the non-target organisms. Plants are able to uptake, transform the veterinary drugs to non- or less-toxic compounds and store them in the vacuoles and cell walls. This ability may protect not only plant themselves but also other organisms, predominantly invertebrates and wild herbivores. The aim of this review is to emphasize the importance of plants in detoxification of veterinary drugs in the environment. The results of studies, which dealt with transport and biotransformation of veterinary drugs in plants, are summarized and evaluated. In conclusion, the risks and consequences of veterinary drugs in the environment and the possibilities of phytoremediation technologies are considered and future perspectives are outlined.

Natural product biosyntheses in cyanobacteria: A treasure trove of unique enzymes.

Science.gov (United States)

Kehr, Jan-Christoph; Gatte Picchi, Douglas; Dittmann, Elke

2011-01-01

Cyanobacteria are prolific producers of natural products. Investigations into the biochemistry responsible for the formation of these compounds have revealed fascinating mechanisms that are not, or only rarely, found in other microorganisms. In this article, we survey the biosynthetic pathways of cyanobacteria isolated from freshwater, marine and terrestrial habitats. We especially emphasize modular nonribosomal peptide synthetase (NRPS) and polyketide synthase (PKS) pathways and highlight the unique enzyme mechanisms that were elucidated or can be anticipated for the individual products. We further include ribosomal natural products and UV-absorbing pigments from cyanobacteria. Mechanistic insights obtained from the biochemical studies of cyanobacterial pathways can inspire the development of concepts for the design of bioactive compounds by synthetic-biology approaches in the future.

Natural product biosyntheses in cyanobacteria: A treasure trove of unique enzymes

Directory of Open Access Journals (Sweden)

Jan-Christoph Kehr

2011-12-01

Full Text Available Cyanobacteria are prolific producers of natural products. Investigations into the biochemistry responsible for the formation of these compounds have revealed fascinating mechanisms that are not, or only rarely, found in other microorganisms. In this article, we survey the biosynthetic pathways of cyanobacteria isolated from freshwater, marine and terrestrial habitats. We especially emphasize modular nonribosomal peptide synthetase (NRPS and polyketide synthase (PKS pathways and highlight the unique enzyme mechanisms that were elucidated or can be anticipated for the individual products. We further include ribosomal natural products and UV-absorbing pigments from cyanobacteria. Mechanistic insights obtained from the biochemical studies of cyanobacterial pathways can inspire the development of concepts for the design of bioactive compounds by synthetic-biology approaches in the future.

Measuring the Enzyme Activity of Arabidopsis Deubiquitylating Enzymes.

Science.gov (United States)

Kalinowska, Kamila; Nagel, Marie-Kristin; Isono, Erika

2016-01-01

Deubiquitylating enzymes, or DUBs, are important regulators of ubiquitin homeostasis and substrate stability, though the molecular mechanisms of most of the DUBs in plants are not yet understood. As different ubiquitin chain types are implicated in different biological pathways, it is important to analyze the enzyme characteristic for studying a DUB. Quantitative analysis of DUB activity is also important to determine enzyme kinetics and the influence of DUB binding proteins on the enzyme activity. Here, we show methods to analyze DUB activity using immunodetection, Coomassie Brilliant Blue staining, and fluorescence measurement that can be useful for understanding the basic characteristic of DUBs.

Cellular Ubc2/Rad6 E2 ubiquitin-conjugating enzyme facilitates tombusvirus replication in yeast and plants

International Nuclear Information System (INIS)

Imura, Yoshiyuki; Molho, Melissa; Chuang, Chingkai; Nagy, Peter D.

2015-01-01

Mono- and multi-ubiquitination alters the functions and subcellular localization of many cellular and viral proteins. Viruses can co-opt or actively manipulate the ubiquitin network to support viral processes or suppress innate immunity. Using yeast (Saccharomyces cerevisiae) model host, we show that the yeast Rad6p (radiation sensitive 6) E2 ubiquitin-conjugating enzyme and its plant ortholog, AtUbc2, interact with two tombusviral replication proteins and these E2 ubiquitin-conjugating enzymes could be co-purified with the tombusvirus replicase. We demonstrate that TBSV RNA replication and the mono- and bi-ubiquitination level of p33 is decreased in rad6Δ yeast. However, plasmid-based expression of AtUbc2p could complement both defects in rad6Δ yeast. Knockdown of UBC2 expression in plants also decreases tombusvirus accumulation and reduces symptom severity, suggesting that Ubc2p is critical for virus replication in plants. We provide evidence that Rad6p is involved in promoting the subversion of Vps23p and Vps4p ESCRT proteins for viral replicase complex assembly. - Highlights: • Tombusvirus p33 replication protein interacts with cellular RAD6/Ubc2 E2 enzymes. • Deletion of RAD6 reduces tombusvirus replication in yeast. • Silencing of UBC2 in plants inhibits tombusvirus replication. • Mono- and bi-ubiquitination of p33 replication protein in yeast and in vitro. • Rad6p promotes the recruitment of cellular ESCRT proteins into the tombusvirus replicase

Cellular Ubc2/Rad6 E2 ubiquitin-conjugating enzyme facilitates tombusvirus replication in yeast and plants

Energy Technology Data Exchange (ETDEWEB)

Imura, Yoshiyuki, E-mail: imura@brs.nihon-u.ac.jp; Molho, Melissa; Chuang, Chingkai; Nagy, Peter D., E-mail: pdnagy2@uky.edu

2015-10-15

Mono- and multi-ubiquitination alters the functions and subcellular localization of many cellular and viral proteins. Viruses can co-opt or actively manipulate the ubiquitin network to support viral processes or suppress innate immunity. Using yeast (Saccharomyces cerevisiae) model host, we show that the yeast Rad6p (radiation sensitive 6) E2 ubiquitin-conjugating enzyme and its plant ortholog, AtUbc2, interact with two tombusviral replication proteins and these E2 ubiquitin-conjugating enzymes could be co-purified with the tombusvirus replicase. We demonstrate that TBSV RNA replication and the mono- and bi-ubiquitination level of p33 is decreased in rad6Δ yeast. However, plasmid-based expression of AtUbc2p could complement both defects in rad6Δ yeast. Knockdown of UBC2 expression in plants also decreases tombusvirus accumulation and reduces symptom severity, suggesting that Ubc2p is critical for virus replication in plants. We provide evidence that Rad6p is involved in promoting the subversion of Vps23p and Vps4p ESCRT proteins for viral replicase complex assembly. - Highlights: • Tombusvirus p33 replication protein interacts with cellular RAD6/Ubc2 E2 enzymes. • Deletion of RAD6 reduces tombusvirus replication in yeast. • Silencing of UBC2 in plants inhibits tombusvirus replication. • Mono- and bi-ubiquitination of p33 replication protein in yeast and in vitro. • Rad6p promotes the recruitment of cellular ESCRT proteins into the tombusvirus replicase.

Association of antioxidative enzymes with the synergistic effect of selenium and UV irradiation in enhancing plant growth

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T. XUE

2008-12-01

Full Text Available Selenium (Se is able to defend human and animal cells against UV(B stress. Higher plants are generally considered not to require Se but to have a low tolerance to it. However, recently it has been demonstrated that Se is able to protect also plants against UV-induced oxidative stress and even to promote the growth of plants subjected to high-energy light. In the present study the effects of Se on antioxidative enzymes possibly associated with this synergistic effect were investigated. Ryegrass and lettuce were grown in soil supplemented with Se at 0, 0.1 or 1.0 mg kg-1 under normal light or subjected to UV episodes. Lipid peroxidation and the changes of antioxidative enzymes were measured at two growing stages. The positive synergistic effect of the lower Se dosage and UV was found to be at least partly associated with the antioxidative role of Se through increased glutathione peroxidase (GSH-Px and catalase (CAT activity, whereas ascorbate peroxidase (APX responded negatively to both factors. The contribution of the other enzymes studied seemed to be plant-specific: glutathione S-transferase (GST increased in both ryegrass assays and superoxide dismutase (SOD in the first lettuce assay. At the higher addition level Se acted as a pro-oxidant and diminished fresh weight yields. UV irradiation alleviated the toxicity coincidently with increase of CAT in ryegrass and SOD in lettuce.;

PlantNATsDB: a comprehensive database of plant natural antisense transcripts.

Science.gov (United States)

Chen, Dijun; Yuan, Chunhui; Zhang, Jian; Zhang, Zhao; Bai, Lin; Meng, Yijun; Chen, Ling-Ling; Chen, Ming

2012-01-01

Natural antisense transcripts (NATs), as one type of regulatory RNAs, occur prevalently in plant genomes and play significant roles in physiological and pathological processes. Although their important biological functions have been reported widely, a comprehensive database is lacking up to now. Consequently, we constructed a plant NAT database (PlantNATsDB) involving approximately 2 million NAT pairs in 69 plant species. GO annotation and high-throughput small RNA sequencing data currently available were integrated to investigate the biological function of NATs. PlantNATsDB provides various user-friendly web interfaces to facilitate the presentation of NATs and an integrated, graphical network browser to display the complex networks formed by different NATs. Moreover, a 'Gene Set Analysis' module based on GO annotation was designed to dig out the statistical significantly overrepresented GO categories from the specific NAT network. PlantNATsDB is currently the most comprehensive resource of NATs in the plant kingdom, which can serve as a reference database to investigate the regulatory function of NATs. The PlantNATsDB is freely available at http://bis.zju.edu.cn/pnatdb/.

Plant Cell Protolytic Enzymes Activity under Exposure to Lectins of Endophytic and Epiphytic Azospirillum Strains

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S.A. Alen’kina

2016-05-01

Full Text Available We studied the ability of lectins isolated from the surface of the two strains of nitrogen-fixing soil bacteria of the genus Azospirillum, A. brasilense Sp7 (epiphytic and A. brasilense Sp245 (endophytic, to show have a regulating effect on the activity of pectinolytic enzymes in the roots of wheat seedlings. Research results showed that the lectins under study can cause the induction of the activity of polygalacturonase, pectinesterase, pectatlyase from the plant cell wall, thereby ensuring the bacteria penetration in the plant tissues, as well as the induction of plants responses which, being combined with growth-stimulating effect of bacteria, contributes to the formation of plants stability and productivity.

Studies on antioxidative enzymes induced by cadmium in pea plants (Pisum sativum).

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Pandey, Nalini; Singh, Gaurav Kumar

2012-03-01

Pea plants (Pisum sativum cv. Swati) exposed to different concentration of cadmium (50,100, 200 microM Cd) under controlled glass house conditions were quantified for different physiological parameters and antioxidative enzymes. In pea plants, Cd produced a significant inhibition of growth and induced chlorosis, marginal yellowing and necrosis in young leaves, the effect being most pronounced at 200 microM Cd supply. An alteration in the activated oxygen metabolism of pea plants were also detected as evidenced by an increase in concentration of H2O2 and TBARS along with decrease in the chlorophyll and carotenoid concentration in leaves. Cadmium toxicity induced an increase in non-protein thiol, ascorbate, proline and cysteine concentration. A significant increment in the activity of SOD, APX and GR, and a decrease in CAT was observed as a result of Cd treatment. The enhanced activity of SOD and inhibition of CAT and POD produces a high build up of H2O2 which appears to be the main cause of oxidative stress due to Cd toxicity in pea plants.

Natural Endophytic Occurrence of Acetobacter diazotrophicus in Pineapple Plants.

Science.gov (United States)

Tapia-Hernández; Bustillos-Cristales; Jiménez-Salgado; Caballero-Mellado; Fuentes-Ramírez

2000-01-01

The presence of endophytic Acetobacter diazotrophicus was tested for pineapple plants (Ananas comosus [L.] Merr.) grown in the field. Diazotrophic bacteria were isolated from the inner tissues of surface sterilized roots, stems, and leaves of pineapple plants. Phenotypic tests permitted the selection of presumptive nitrogen-fixing A. diazotrophicus isolates. Restriction fragment length polymorphisms (RFLPs) of small subunit (SSU) rDNA using total DNA digested with endonuclease SphI and with endonuclease NcoI, hybridizations of RNA with an A. diazotrophicus large subunit (LSU) rRNA specific probe, as well as patterns in denaturing protein electrophoresis (SDS-PAGE) and multilocus enzyme tests allowed the identification of A. diazotrophicus isolates. High frequencies of isolation were obtained from propagative buds that had not been nitrogen-fertilized, and lower frequencies from 3-month-old plants that had been nitrogen-fertilized. No isolates were recovered from 5- to 7-month-old nitrogen-fertilized plants. All the A. diazotrophicus isolates recovered from pineapple plants belonged to the multilocus genotype which shows the most extensive distribution among all host species previously analyzed.

Plant extraction process

DEFF Research Database (Denmark)

2006-01-01

A method for producing a plant extract comprises incubating a plant material with an enzyme composition comprising a lipolytic enzyme.......A method for producing a plant extract comprises incubating a plant material with an enzyme composition comprising a lipolytic enzyme....

Naturalization of European plants on other continents: The role of donor habitats.

Science.gov (United States)

Kalusová, Veronika; Chytrý, Milan; van Kleunen, Mark; Mucina, Ladislav; Dawson, Wayne; Essl, Franz; Kreft, Holger; Pergl, Jan; Weigelt, Patrick; Winter, Marten; Pyšek, Petr

2017-12-26

The success of European plant species as aliens worldwide is thought to reflect their association with human-disturbed environments. However, an explicit test including all human-made, seminatural and natural habitat types of Europe, and their contributions as donor habitats of naturalized species to the rest of the globe, has been missing. Here we combine two databases, the European Vegetation Checklist and the Global Naturalized Alien Flora, to assess how human influence in European habitats affects the probability of naturalization of their plant species on other continents. A total of 9,875 native European vascular plant species were assigned to 39 European habitat types; of these, 2,550 species have become naturalized somewhere in the world. Species that occur in both human-made habitats and seminatural or natural habitats in Europe have the highest probability of naturalization (64.7% and 64.5% of them have naturalized). Species associated only with human-made or seminatural habitats still have a significantly higher probability of becoming naturalized (41.7% and 28.6%, respectively) than species confined to natural habitats (19.4%). Species associated with arable land and human settlements were recorded as naturalized in the largest number of regions worldwide. Our findings highlight that plant species' association with native-range habitats disturbed by human activities, combined with broad habitat range, play an important role in shaping global patterns of plant invasions.

Evaluation of enzymes inhibition activities of medicinal plant from Burkina Faso.

Science.gov (United States)

Bangou, Mindiédiba Jean; Kiendrebeogo, Martin; Meda, Nâg-Tiero Roland; Coulibaly, Ahmed Yacouba; Compaoré, Moussa; Zeba, Boukaré; Millogo-Rasolodimby, Jeanne; Nacoulma, Odile Germaine

2011-01-15

The aim of the present study was to evaluate some enzymes inhibitory effects of 11 plant species belonging to 9 families from Burkina Faso. Methanolic extracts were used for their Glutathione-s-transferase (GST), Acetylcholinesterase (AChE), Carboxylesterase (CES) and Xanthine Oxidase (XO) inhibitory activities at final concentration of 100 microg mL(-1). The total phenolics, flavonoids and tannins were also determined spectrophotometrically using Folin-Ciocalteu, AlCl3 and ammonium citrate iron reagents, respectively. Among the 11 species tested, the best inhibitory percentages were found with Euphorbia hirta, Sclerocarya birrea and Scoparia dulcis (inhibition > 40%) followed by Annona senegalensis, Annona squamosa, Polygala arenaria and Ceratotheca sesamoides (inhibition > 25%). The best total phenolic and tannin contents were found with S. birrea with 56.10 mg GAE/100 mg extract and 47.75 mg TAE/100 mg extract, respectively. E hirta presented the higher total flavonoids (9.96 mg QE/100 mg extract). It's was found that Sclerocarya birrea has inhibited all enzymes at more than 30% and this activity is correlated to total tannins contents. Contrary to S. birrea, the enzymatic activities of E. hirta and S. dulcis are correlated to total flavonoids contents. Present findings suggest that the methanolic extracts of those plant species are potential inhibitors of GST, AChE, CES and XO and confirm their traditional uses in the treatment of mental disorders, gout, painful inflammations and cardiovascular diseases.

The Attractivity of Ornamental Plants to Some Natural Enemies of Pest

Directory of Open Access Journals (Sweden)

Fatima Ramdan Muhamed Al Kawan

2018-01-01

Full Text Available There are several roles of ornamental plants to environment management and human being. One of them is to attract some natural enemies of pest which more ecofriendly and specific target. Related with this role, the objectives of this study are to inventory kind of ornamental plants in the play ground, to inventory kind of ornamental plants which attract natural enemies, and to know the foreign students perception to the function of the ornamental plant species for attracting the natural enemies. This study was conducted using Visual Encounter Survey (VES method with three repetitions. The result showed that there were 5 ornamental plants in the area study as Acalypha siamensis, Osmoxylon lineare, Canna indica, Crinum asiaticum L. and Oleina syzigium. Data analysis using Community structure of Arthropods, Index of Diversity, and Index of Similarity on different area. The result Based on the average of species abundance, O. lineare is the most visited plant by animals. It was showed from range of average of species abundance which reached from 0.17 to 13.72 individu. The second one was A. siamensis which had average of species abundance 0.14 - 13.14 individu. The next plant which visited by many animals are C. indica and C. asiaticum L. The average of species abundance respectively varied from 0.43 to 12.00 individu and from 0.14 to 8.72 individu. Oleina syzigium became the least one, because the average of species abundance reached from 0.14 to 3.14 individu. Overall, the level of respondents (foreign students knowledge about the function of ornamental plants for attracting natural enemies was categorized into high Key words: Attractivity, Natural enemies, Ornamental plants

Estimation of Nitrogenase Enzyme Activities and Plant Growth of Legume and Non-legume Inoculated with Diazotrophic Bacteria

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Salwani S.

2012-06-01

Full Text Available Biological Nitrogen Fixation (BNF process benefits the agriculture sector especially for reducing cost of nitrogenfertilizer. In the process, the diazotrophs convert N2 into ammonia (NH3 which is useable by plants. The BNF process iscatalysed by nitrogenase enzyme that involved protons and electrons together with evolution of H2 therefore, theassessment of N2 fixation is also available via H2 production and electron allocation analysis. Thus, the aims of thisexperiment were to estimate the nitrogenase enzyme activities and observe the influence of diazothrophs on growth oflegume (soybean and non legume (rice plants. Host plants were inoculated with respective inocula; Bradyrhizobiumjaponicum (strain 532C for soybean while Azospirillum brasilense (Sp7 and locally isolated diazotroph (isolate 5 forrice. At harvest, the plants were observed for plant growth parameters, H2 evolution, N2 fixation and electron allocationcoefficient (EAC values. The experiment recorded N2 fixation activities of inoculated soybean plants at 141.2 μmol N2 h-1g-1 dry weight nodule, and the evolution of H2 at 144.4 μmol H2 h-1 g-1 dry weight nodule. The electron allocationcoefficient (EAC of soybean was recorded at 0.982. For inoculated rice plants, none of the observations was successfully recorded. However, results for chlorophyll contents and plant dry weight of both plants inoculated with respective inocula were similar to the control treatments supplied with full nitrogen fertilization (+N. The experiment clearly showed that inoculation of diazotrophic bacteria could enhance growth of the host plants similar to plants treated with nitrogenous fertilizer due to efficient N2 fixation process

Plant fatty acyl reductases: enzymes generating fatty alcohols for protective layers with potential for industrial applications.

Science.gov (United States)

Rowland, Owen; Domergue, Frédéric

2012-09-01

Primary fatty alcohols are found throughout the biological world, either in free form or in a combined state. They are common components of plant surface lipids (i.e. cutin, suberin, sporopollenin, and associated waxes) and their absence can significantly perturb these essential barriers. Fatty alcohols and/or derived compounds are also likely to have direct functions in plant biotic and abiotic interactions. An evolutionarily related set of alcohol-forming fatty acyl reductases (FARs) is present in all kingdoms of life. Plant microsomal and plastid-associated FAR enzymes have been characterized, acting on acyl-coenzymeA (acyl-CoA) or acyl-acyl carrier protein (acyl-ACP) substrates, respectively. FARs have distinct substrate specificities both with regard to chain length and chain saturation. Fatty alcohols and wax esters, which are a combination of fatty alcohol and fatty acid, have a variety of commercial applications. The expression of FARs with desired specificities in transgenic microbes or oilseed crops would provide a novel means of obtaining these valuable compounds. In the present review, we report on recent progress in characterizing plant FAR enzymes and in understanding the biological roles of primary fatty alcohols, as well as describe the biotechnological production and industrial uses of fatty alcohols. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Soil microflora and enzyme activities in rhizosphere of Transgenic Bt cotton hybrid under different intercropping systems and plant protection schedules

Science.gov (United States)

Biradar, D. P.; Alagawadi, A. R.; Basavanneppa, M. A.; Udikeri, S. S.

2012-04-01

Field experiments were conducted over three rainy seasons of 2005-06 to 2007-08 on a Vertisol at Dharwad, Karnataka, India to study the effect of intercropping and plant protection schedules on productivity, soil microflora and enzyme activities in the rhizosphere of transgenic Bt cotton hybrid. The experiment consisted of four intercropping systems namely, Bt cotton + okra, Bt cotton + chilli, Bt cotton + onion + chilli and Bt cotton + redgram with four plant protection schedules (zero protection, protection for Bt cotton, protection for intercrop and protection for both crops). Observations on microbial populations and enzyme activities were recorded at 45, 90, 135 and 185 (at harvest) days after sowing (DAS). Averaged over years, Bt cotton + okra intercropping had significantly higher total productivity than Bt cotton + chilli and Bt cotton + redgram intercropping system and was similar to Bt cotton + chilli + onion intercropping system. With respect to plant protection schedules for bollworms, protection for both cotton and intercrops recorded significantly higher yield than the rest of the treatments. Population of total bacteria, fungi, actinomycetes, P-solubilizers, free-living N2 fixers as well as urease, phosphatase and dehydrogenase enzyme activities increased up to 135 days of crop growth followed by a decline. Among the intercropping systems, Bt cotton + chilli recorded significantly higher population of microorganisms and enzyme activities than other cropping systems. While Bt cotton with okra as intercrop recorded the least population of total bacteria and free-living N2 fixers as well as urease activity. Intercropping with redgram resulted in the least population of actinomycetes, fungi and P-solubilizers, whereas Bt cotton with chilli and onion recorded least activities of dehydrogenase and phosphatase. Among the plant protection schedules, zero protection recorded maximum population of microorganisms and enzyme activities. This was followed by the

The natural radioactivity of plants, animals and humans. 3. enl. ed.

International Nuclear Information System (INIS)

Schewtschenko, I.N.; Danilenko, A.I.

2007-01-01

The natural radioactivity of plants, animals and humans are of important scientific relevance for radiobiology and medicine. The possible effects of micro doses during life span are still controversially discussed. Part I of the book (the natural radioactivity of plants, animals and humans for the normal case and in case of pathological changes) covers the following topics: the natural radioisotopes in living organisms (plants, animals, humans) and their environment; methodologies of qualitative and quantitative determination of beta-activity in biological objects; the radioactivity of atmospheric precipitations; the beta-activity of plants; the beta-activity of animals; beta-activity of human organs and tissues. Part II (dynamics of radionuclides in the biological chains in the period 1960 to 2007): the modern conceptions on the biological role of natural radioactive elements, biological indications during early stages of low-dose ionizing irradiation; the radioactivity of the human blood; radiation and carcerogenesis

Enzyme-linked immunosorbent assay for the quantitative/qualitative analysis of plant secondary metabolites.

Science.gov (United States)

Sakamoto, Seiichi; Putalun, Waraporn; Vimolmangkang, Sornkanok; Phoolcharoen, Waranyoo; Shoyama, Yukihiro; Tanaka, Hiroyuki; Morimoto, Satoshi

2018-01-01

Immunoassays are antibody-based analytical methods for quantitative/qualitative analysis. Since the principle of immunoassays is based on specific antigen-antibody reaction, the assays have been utilized worldwide for diagnosis, pharmacokinetic studies by drug monitoring, and the quality control of commercially available products. Berson and Yalow were the first to develop an immunoassay, known as radioimmunoassay (RIA), for detecting endogenous plasma insulin [1], a development for which Yalow was awarded the Nobel Prize in Physiology or Medicine in 1977. Even today, after half a century, immunoassays are widely utilized with some modifications from the originally proposed system, e.g., radioisotopes have been replaced with enzymes because of safety concerns regarding the use of radioactivity, which is referred to as enzyme immunoassay/enzyme-linked immunosorbent assay (ELISA). In addition, progress has been made in ELISA with the recent advances in recombinant DNA technology, leading to increase in the range of antibodies, probes, and even systems. This review article describes ELISA and its applications for the detection of plant secondary metabolites.

Potentilla fulgens (Family Rosaceae), a medicinal plant of north-east India: a natural anthelmintic?

Science.gov (United States)

Roy, Bishnupada; Swargiary, Ananta; Syiem, D; Tandon, V

2010-10-01

The cestode parasite, Raillietina echinobothrida and the trematode, Gastrothylax crumenifer were exposed to the ethanolic root peel extract of Potentilla fulgens, an antiparasitic local medicinal plant of Meghalaya, India, to evaluate the anthelmintic efficacy of the plant. The parasites were incubated in 1, 5, 10, 20, 50 and 100 mg crude alcoholic extract per ml of phosphate buffered saline (PBS) at a temperature of 37 ± 1°C. Paralysis and death were observed at 2.00 ± 0.05 and 2.80 ± 0.06 h for the cestode and 1.21 ± 0.06 and 2.18 ± 0.04 h for the trematode parasites at the highest test concentration of the plant extract. The commercial anthelmintic, Praziquantel (PZQ) showed higher activity at the tested concentration (0.02 mg/ml). To further investigate the efficacy of the plant extract, vital tegumental enzymes of the parasite viz. Acid phosphatase (AcPase), Alkaline phosphatase (AlkPase) and Adenosine triphosphatase (ATPase) were studied. Quantitatively, the total enzyme activity of AcPase, AlkPase and ATPase was found to be reduced significantly by 69.20, 66.43 and 29.63% for R. echinobothrida and 47.96, 51.79 and 42.63% for G. crumenifer, respectively compared to the respective controls; histochemical study also showed reduction in the visible staining of the enzymes. The reference drug, PZQ also showed more or less similar effect like that of the plant extract. The result suggests that phytochemicals of P. fulgens have anthelmintic potential.

Production by Tobacco Transplastomic Plants of Recombinant Fungal and Bacterial Cell-Wall Degrading Enzymes to Be Used for Cellulosic Biomass Saccharification.

Science.gov (United States)

Longoni, Paolo; Leelavathi, Sadhu; Doria, Enrico; Reddy, Vanga Siva; Cella, Rino

2015-01-01

Biofuels from renewable plant biomass are gaining momentum due to climate change related to atmospheric CO2 increase. However, the production cost of enzymes required for cellulosic biomass saccharification is a major limiting step in this process. Low-cost production of large amounts of recombinant enzymes by transgenic plants was proposed as an alternative to the conventional microbial based fermentation. A number of studies have shown that chloroplast-based gene expression offers several advantages over nuclear transformation due to efficient transcription and translation systems and high copy number of the transgene. In this study, we expressed in tobacco chloroplasts microbial genes encoding five cellulases and a polygalacturonase. Leaf extracts containing the recombinant enzymes showed the ability to degrade various cell-wall components under different conditions, singly and in combinations. In addition, our group also tested a previously described thermostable xylanase in combination with a cellulase and a polygalacturonase to study the cumulative effect on the depolymerization of a complex plant substrate. Our results demonstrate the feasibility of using transplastomic tobacco leaf extracts to convert cell-wall polysaccharides into reducing sugars, fulfilling a major prerequisite of large scale availability of a variety of cell-wall degrading enzymes for biofuel industry.

Natural Antioxidants in Foods and Medicinal Plants: Extraction, Assessment and Resources.

Science.gov (United States)

Xu, Dong-Ping; Li, Ya; Meng, Xiao; Zhou, Tong; Zhou, Yue; Zheng, Jie; Zhang, Jiao-Jiao; Li, Hua-Bin

2017-01-05

Natural antioxidants are widely distributed in food and medicinal plants. These natural antioxidants, especially polyphenols and carotenoids, exhibit a wide range of biological effects, including anti-inflammatory, anti-aging, anti-atherosclerosis and anticancer. The effective extraction and proper assessment of antioxidants from food and medicinal plants are crucial to explore the potential antioxidant sources and promote the application in functional foods, pharmaceuticals and food additives. The present paper provides comprehensive information on the green extraction technologies of natural antioxidants, assessment of antioxidant activity at chemical and cellular based levels and their main resources from food and medicinal plants.

Expression, purification, crystallization and preliminary X-ray analysis of perakine reductase, a new member of the aldo-keto reductase enzyme superfamily from higher plants

Energy Technology Data Exchange (ETDEWEB)

Rosenthal, Cindy [Department of Pharmaceutical Biology, Institute of Pharmacy, Johannes Gutenberg-University Mainz, Staudinger Weg 5, D-55099 Mainz (Germany); Mueller, Uwe [Berliner Elektronenspeicherring-Gesellschaft für Synchrotronstrahlung mbH, Albert-Einstein-Strasse 15, D-12489 Berlin (Germany); Panjikar, Santosh [European Molecular Biology Laboratory Hamburg, Outstation Deutsches Elektronen-Synchrotron, Notkestrasse 85, D-22603 Hamburg (Germany); Sun, Lianli [Department of Pharmaceutical Biology, Institute of Pharmacy, Johannes Gutenberg-University Mainz, Staudinger Weg 5, D-55099 Mainz (Germany); Department of TCM and Natural Drug Research, College of Pharmaceutical Sciences, 513 Zijingang Campus, Zhejiang University, 310058 Hangzhou (China); Ruppert, Martin [Department of Pharmaceutical Biology, Institute of Pharmacy, Johannes Gutenberg-University Mainz, Staudinger Weg 5, D-55099 Mainz (Germany); Zhao, Yu [Department of TCM and Natural Drug Research, College of Pharmaceutical Sciences, 513 Zijingang Campus, Zhejiang University, 310058 Hangzhou (China); Stöckigt, Joachim [Department of Pharmaceutical Biology, Institute of Pharmacy, Johannes Gutenberg-University Mainz, Staudinger Weg 5, D-55099 Mainz (Germany); Department of TCM and Natural Drug Research, College of Pharmaceutical Sciences, 513 Zijingang Campus, Zhejiang University, 310058 Hangzhou (China)

2006-12-01

Perakine reductase, a novel member of the aldo-keto reductase enzyme superfamily of higher plants, is involved in the biosynthesis of monoterpenoid indole alkaloids in the Indian medicinal plant Rauvolfia serpentina. The enzyme has been crystallized in C-centered orthorhombic space group and diffracts to 2.0 Å resolution. Perakine reductase (PR) is a novel member of the aldo-keto reductase enzyme superfamily from higher plants. PR from the plant Rauvolfia serpentina is involved in the biosynthesis of monoterpenoid indole alkaloids by performing NADPH-dependent reduction of perakine, yielding raucaffrinoline. However, PR can also reduce cinnamic aldehyde and some of its derivatives. After heterologous expression of a triple mutant of PR in Escherichia coli, crystals of the purified and methylated enzyme were obtained by the hanging-drop vapour-diffusion technique at 293 K with 100 mM sodium citrate pH 5.6 and 27% PEG 4000 as precipitant. Crystals belong to space group C222{sub 1} and diffract to 2.0 Å, with unit-cell parameters a = 58.9, b = 93.0, c = 143.4 Å.

Expression, purification, crystallization and preliminary X-ray analysis of perakine reductase, a new member of the aldo-keto reductase enzyme superfamily from higher plants

International Nuclear Information System (INIS)

Rosenthal, Cindy; Mueller, Uwe; Panjikar, Santosh; Sun, Lianli; Ruppert, Martin; Zhao, Yu; Stöckigt, Joachim

2006-01-01

Perakine reductase, a novel member of the aldo-keto reductase enzyme superfamily of higher plants, is involved in the biosynthesis of monoterpenoid indole alkaloids in the Indian medicinal plant Rauvolfia serpentina. The enzyme has been crystallized in C-centered orthorhombic space group and diffracts to 2.0 Å resolution. Perakine reductase (PR) is a novel member of the aldo-keto reductase enzyme superfamily from higher plants. PR from the plant Rauvolfia serpentina is involved in the biosynthesis of monoterpenoid indole alkaloids by performing NADPH-dependent reduction of perakine, yielding raucaffrinoline. However, PR can also reduce cinnamic aldehyde and some of its derivatives. After heterologous expression of a triple mutant of PR in Escherichia coli, crystals of the purified and methylated enzyme were obtained by the hanging-drop vapour-diffusion technique at 293 K with 100 mM sodium citrate pH 5.6 and 27% PEG 4000 as precipitant. Crystals belong to space group C222 1 and diffract to 2.0 Å, with unit-cell parameters a = 58.9, b = 93.0, c = 143.4 Å

Probabilities of Natural Events Occurring at Savannah River Plant

Energy Technology Data Exchange (ETDEWEB)

Huang, J.C.

2001-07-17

This report documents the comprehensive evaluation of probability models of natural events which are applicable to Savannah River Plant. The probability curves selected for these natural events are recommended to be used by all SRP/SRL safety analysts. This will ensure a consistency in analysis methodology for postulated SAR incidents involving natural phenomena.

Natural radioactivity releases from lignite power plants in Southwestern Anatolia

International Nuclear Information System (INIS)

Yaprak, G.; Guer, F.; Cam, F.; Candan, O.

2006-01-01

The Mugla basin is one of the most productive lignite basins in Southwestern Anatolia, Turkey. Mining activities started in 1979 and total reserves were estimated during exploration at 767.5 million tonnes. Total mean annual lignite production of the Mugla basin is estimated at about 10 million tonnes per year. Most of the lignite production supplies three thermal power plants (Yatagan 630 MW, Yenikoey 420 MW, Kemerkoey 630 MW) with a total capacity of 1680 MW. It is well known that the lignite contains naturally occurring primordial radionuclides arising from the uranium and thorium series as well as from 4 0K. Lignite burning is, therefore, one of the sources of technologically enhanced exposure to humans from natural radionuclides. The investigation reported here deals with the determination of the 2 26Ra, 2 32Th and 4 0K concentrations in the lignite feeding 3 thermal power plants in Mugla region and in the product ash. Samples of lignite feeding the power plants and fly and bottom ashes produced in the same power plants were collected over a period of 1 year and therefore systematic sampling allowed for the determination of mean representative values for the natural radioactivity content of above materials and also estimation of the radioactivity releases to the environment. Furthermore, grid soil sampling within 10-15 km around the power plants allowed for the mapping of the surface soil activity of natural radionuclides. Dosimetric calculations from terrestrial gamma radiation for the population living around the power plants were performed based on the guidance of UNSCEAR 2000 report

Fuel prices, emission standards, and generation costs for coal vs natural gas power plants.

Science.gov (United States)

Pratson, Lincoln F; Haerer, Drew; Patiño-Echeverri, Dalia

2013-05-07

Low natural gas prices and stricter, federal emission regulations are promoting a shift away from coal power plants and toward natural gas plants as the lowest-cost means of generating electricity in the United States. By estimating the cost of electricity generation (COE) for 304 coal and 358 natural gas plants, we show that the economic viability of 9% of current coal capacity is challenged by low natural gas prices, while another 56% would be challenged by the stricter emission regulations. Under the current regulations, coal plants would again become the dominant least-cost generation option should the ratio of average natural gas to coal prices (NG2CP) rise to 1.8 (it was 1.42 in February 2012). If the more stringent emission standards are enforced, however, natural gas plants would remain cost competitive with a majority of coal plants for NG2CPs up to 4.3.

Do Refuge Plants Favour Natural Pest Control in Maize Crops?

Science.gov (United States)

Quispe, Reinaldo; Mazón, Marina; Rodríguez-Berrío, Alexander

2017-01-01

The use of non-crop plants to provide the resources that herbivorous crop pests’ natural enemies need is being increasingly incorporated into integrated pest management programs. We evaluated insect functional groups found on three refuges consisting of five different plant species each, planted next to a maize crop in Lima, Peru, to investigate which refuge favoured natural control of herbivores considered as pests of maize in Peru, and which refuge plant traits were more attractive to those desirable enemies. Insects occurring in all the plants, including the maize crop itself, were sampled weekly during the crop growing cycle, from February to June 2011. All individuals collected were identified and classified into three functional groups: herbivores, parasitoids, and predators. Refuges were compared based on their effectiveness in enhancing the populations of predator and parasitoid insects of the crop enemies. Refuges A and B were the most effective, showing the highest richness and abundance of both predators and parasitoids, including several insect species that are reported to attack the main insect pests of maize (Spodoptera frugiperda and Rhopalosiphum maidis), as well as other species that serve as alternative hosts of these natural enemies. PMID:28718835

Novel NAD+-Farnesal Dehydrogenase from Polygonum minus Leaves. Purification and Characterization of Enzyme in Juvenile Hormone III Biosynthetic Pathway in Plant.

Directory of Open Access Journals (Sweden)

Ahmad-Faris Seman-Kamarulzaman

Full Text Available Juvenile Hormone III is of great concern due to negative effects on major developmental and reproductive maturation in insect pests. Thus, the elucidation of enzymes involved JH III biosynthetic pathway has become increasing important in recent years. One of the enzymes in the JH III biosynthetic pathway that remains to be isolated and characterized is farnesal dehydrogenase, an enzyme responsible to catalyze the oxidation of farnesal into farnesoic acid. A novel NAD+-farnesal dehydrogenase of Polygonum minus was purified (315-fold to apparent homogeneity in five chromatographic steps. The purification procedures included Gigacap S-Toyopearl 650M, Gigacap Q-Toyopearl 650M, and AF-Blue Toyopearl 650ML, followed by TSK Gel G3000SW chromatographies. The enzyme, with isoelectric point of 6.6 is a monomeric enzyme with a molecular mass of 70 kDa. The enzyme was relatively active at 40°C, but was rapidly inactivated above 45°C. The optimal temperature and pH of the enzyme were found to be 35°C and 9.5, respectively. The enzyme activity was inhibited by sulfhydryl agent, chelating agent, and metal ion. The enzyme was highly specific for farnesal and NAD+. Other terpene aldehydes such as trans- cinnamaldehyde, citral and α- methyl cinnamaldehyde were also oxidized but in lower activity. The Km values for farnesal, citral, trans- cinnamaldehyde, α- methyl cinnamaldehyde and NAD+ were 0.13, 0.69, 0.86, 1.28 and 0.31 mM, respectively. The putative P. minus farnesal dehydrogenase that's highly specific towards farnesal but not to aliphatic aldehydes substrates suggested that the enzyme is significantly different from other aldehyde dehydrogenases that have been reported. The MALDI-TOF/TOF-MS/MS spectrometry further identified two peptides that share similarity to those of previously reported aldehyde dehydrogenases. In conclusion, the P. minus farnesal dehydrogenase may represent a novel plant farnesal dehydrogenase that exhibits distinctive substrate

Manufacturing economics of plant-made biologics: case studies in therapeutic and industrial enzymes.

Science.gov (United States)

Tusé, Daniel; Tu, Tiffany; McDonald, Karen A

2014-01-01

Production of recombinant biologics in plants has received considerable attention as an alternative platform to traditional microbial and animal cell culture. Industrially relevant features of plant systems include proper eukaryotic protein processing, inherent safety due to lack of adventitious agents, more facile scalability, faster production (transient systems), and potentially lower costs. Lower manufacturing cost has been widely claimed as an intuitive feature of the platform by the plant-made biologics community, even though cost information resides within a few private companies and studies accurately documenting such an advantage have been lacking. We present two technoeconomic case studies representing plant-made enzymes for diverse applications: human butyrylcholinesterase produced indoors for use as a medical countermeasure and cellulases produced in the field for the conversion of cellulosic biomass into ethanol as a fuel extender. Production economics were modeled based on results reported with the latest-generation expression technologies on Nicotiana host plants. We evaluated process unit operations and calculated bulk active and per-dose or per-unit costs using SuperPro Designer modeling software. Our analyses indicate that substantial cost advantages over alternative platforms can be achieved with plant systems, but these advantages are molecule/product-specific and depend on the relative cost-efficiencies of alternative sources of the same product.

Manufacturing Economics of Plant-Made Biologics: Case Studies in Therapeutic and Industrial Enzymes

Directory of Open Access Journals (Sweden)

Daniel Tusé

2014-01-01

Full Text Available Production of recombinant biologics in plants has received considerable attention as an alternative platform to traditional microbial and animal cell culture. Industrially relevant features of plant systems include proper eukaryotic protein processing, inherent safety due to lack of adventitious agents, more facile scalability, faster production (transient systems, and potentially lower costs. Lower manufacturing cost has been widely claimed as an intuitive feature of the platform by the plant-made biologics community, even though cost information resides within a few private companies and studies accurately documenting such an advantage have been lacking. We present two technoeconomic case studies representing plant-made enzymes for diverse applications: human butyrylcholinesterase produced indoors for use as a medical countermeasure and cellulases produced in the field for the conversion of cellulosic biomass into ethanol as a fuel extender. Production economics were modeled based on results reported with the latest-generation expression technologies on Nicotiana host plants. We evaluated process unit operations and calculated bulk active and per-dose or per-unit costs using SuperPro Designer modeling software. Our analyses indicate that substantial cost advantages over alternative platforms can be achieved with plant systems, but these advantages are molecule/product-specific and depend on the relative cost-efficiencies of alternative sources of the same product.

Soil Properties and Plant Biomass Production in Natural Rangeland Management Systems

Directory of Open Access Journals (Sweden)

Romeu de Souza Werner

Full Text Available ABSTRACT Improper management of rangelands can cause land degradation and reduce the economic efficiency of livestock activity. The aim of this study was to evaluate soil properties and quantify plant biomass production in four natural rangeland management systems in the Santa Catarina Plateau (Planalto Catarinense of Brazil. The treatments, which included mowed natural rangeland (NR, burned natural rangeland (BR, natural rangeland improved through the introduction of plant species after harrowing (IH, and natural rangeland improved through the introduction of plant species after chisel plowing (IC, were evaluated in a Nitossolo Bruno (Nitisol. In the improved treatments, soil acidity was corrected, phosphate fertilizer was applied, and intercropped annual ryegrass (Lolium multiflorum, velvet grass (Holcus lanatus, and white clover (Trifolium repens were sown. Management systems with harrowed or chisel plowed soil showed improved soil physical properties; however, the effect decreased over time and values approached those of burned and mowed natural rangelands. Natural rangeland systems in the establishment phase had little influence on soil organic C. The mowed natural rangeland and improved natural rangeland exhibited greater production of grazing material, while burning the field decreased production and increased the proportion of weeds. Improvement of the natural rangelands increased leguminous biomass for pasture.

Drought Signaling in Plants

Indian Academy of Sciences (India)

depending upon the source and nature of signaling: (i) hormone signal, (ii) .... plants to regulate the rate of transpiration through minor structural .... cell has to keep spending energy (in the form of A TP) to maintain a .... enzymes and proteins in the regulation of cellular metabolism can be determined by either inactivating.

Fungal enzymes in the attine ant symbiosis

DEFF Research Database (Denmark)

de Fine Licht, Henrik Hjarvard; Schiøtt, Morten; Boomsma, Jacobus Jan

the more basal attine genera use substrates such as flowers, plant debris, small twigs, insect feces and insect carcasses. This diverse array of fungal substrates across the attine lineage implies that the symbiotic fungus needs different enzymes to break down the plant material that the ants provide...... or different efficiencies of enzyme function. Fungal enzymes that degrade plant cell walls may have functionally co-evolved with the ants in this scenario. We explore this hypothesis with direct measurements of enzyme activity in fungus gardens in 12 species across 8 genera spanning the entire phylogeny...... and diversity of life-styles within the attine clade. We find significant differences in enzyme activity between different genera and life-styles of the ants. How these findings relate to attine ant coevolution and crop optimization are discussed....

Decarboxylation of Malate in the Crassulacean Acid Metabolism Plant Bryophyllum (Kalanchoe) fedtschenkoi (Role of NAD-Malic Enzyme).

Science.gov (United States)

Cook, R. M.; Lindsay, J. G.; Wilkins, M. B.; Nimmo, H. G.

1995-01-01

The role of NAD-malic enzyme (NAD-ME) in the Crassulacean acid metabolism plant Bryophyllum (Kalanchoe) fedtschenkoi was investigated using preparations of intact and solubilized mitochondria from fully expanded leaves. Intact, coupled mitochondria isolated during the day or night did not differ in their ability to take up [14C]malic acid from the surrounding medium or to respire using malate or succinate as substrate. However, intact mitochondria isolated from plants during the day decarboxylated added malate to pyruvate significantly faster than mitochondria isolated from plants at night. NAD-ME activity in solubilized mitochondrial extracts showed hysteretic kinetics and was stimulated by a number of activators, including acetyl-coenzyme A, fructose-1,6-bisphosphate, and sulfate ions. In the absence of these effectors, reaction progress curves were nonlinear, with a pronounced acceleration phase. The lag period before a steady-state rate was reached in assays of mitochondrial extracts decreased during the photoperiod and increased slowly during the period of darkness. However, these changes in the kinetic properties of the enzyme could not account for the changes in the rate of decarboxylation of malate by intact mitochondria. Gel-filtration experiments showed that mitochondrial extracts contained three forms of NAD-ME with different molecular weights. The relative proportions of the three forms varied somewhat throughout the light/dark cycle, but this did not account for the changes in the kinetics behavior of the enzyme during the diurnal cycle. PMID:12228671

Floating natural gas processing plants. Technical ideal or feasible technology

Energy Technology Data Exchange (ETDEWEB)

Backhaus, H

1977-04-01

Realizability of floating natural gas processing plants is decisively influenced by the economy of the system. Illustrated by the example of the natural gas product LPG (liquefied petroleum gas), a model cost calculation is carried out. It is demonstrated that the increase in the price level during the 1973/1974 energy crisis is an important factor for the realiability in terms of economy of such complicated technical systems. Another aspect which the model calculation revealed is that the economy of floating natural gas processing plants and storage systems can only be estimated in connection with other system components.

Ozone sensitivity of plants in natural communities

Energy Technology Data Exchange (ETDEWEB)

Treshow, M; Stewart, D

1973-07-01

Field fumigation studies conducted in grassland, oak, aspen, and conifer, communities established the injury threshold of prevalent plant species to ozone. Several important species, including Bromus tectorum, Quercus gambelii, and Populus tremuloides, were injured by a single 2-hours exposure to 15 pphM ozone. Over half the perennial forbs and woody species studied were visibly injured at concentrations of 30 pphM ozone or less. It is postulated that lower concentrations at prolonged or repeated exposures to ozone may impair growth and affect community vigor and stability. Continued exposure of natural plant communities to ozone is expected to initiate major shifts in the plant composition of communities. 10 references, 4 figures, 1 table.

Can plant-natural enemy communication withstand disruption by biotic and abiotic factors?

Science.gov (United States)

Clavijo McCormick, Andrea

2016-12-01

The attraction of natural enemies towards herbivore-induced plant volatiles is a well-documented phenomenon. However, the majority of published studies are carried under optimal water and nutrient regimes and with just one herbivore. But what happens when additional levels of ecological complexity are added? Does the presence of a second herbivore, microorganisms, and abiotic stress interfere with plant-natural enemy communication? or is communication stable enough to withstand disruption by additional biotic and abiotic factors?Investigating the effects of these additional levels of ecological complexity is key to understanding the stability of tritrophic interactions in natural ecosystems and may aid to forecast the impact of environmental disturbances on these, especially in climate change scenarios, which are often associated with modifications in plant and arthropod species distribution and increased levels of abiotic stress.This review explores the literature on natural enemy attraction to herbivore-induced volatiles when, besides herbivory, plants are challenged by additional biotic and abiotic factors.The aim of this review was to establish the impact of different biotic and abiotic factors on plant-natural enemy communication and to highlight critical aspects to guide future research efforts.

Simple and robust determination of the activity signature of key carbohydrate metabolism enzymes for physiological phenotyping in model and crop plants

DEFF Research Database (Denmark)

Jammer, Alexandra; Gasperl, Anna; Luschin-Ebengreuth, Nora

2015-01-01

The analysis of physiological parameters is important to understand the link between plant phenotypes and their genetic bases, and therefore is needed as an important element in the analysis of model and crop plants. The activities of enzymes involved in primary carbohydrate metabolism have been...... shown to be strongly associated with growth performance, crop yield, and quality, as well as stress responses. A simple, fast, and cost-effective method to determine activities for 13 key enzymes involved in carbohydrate metabolism has been established, mainly based on coupled spectrophotometric kinetic...

Effects of supplemental enzymes on apparent nutrient digestibility in rainbow trout (Oncorhynchus mykiss) fed plant-based diets

DEFF Research Database (Denmark)

Dalsgaard, Anne Johanne Tang; Hjermitslev, Niels Harthøj; Ekmann, Kim Schøn

2010-01-01

in fish feed due to growing demands for and high price variations in fish meal, but high inclusion levels in diets for carnivorous fish are hampered by a great variety of anti-nutritional factors (ANFs), which reduce nutrient utilisation. Exogenous dietary enzymes may potentially help to alleviate...... on the effects of enzymes in fish feed apart from phytase. Phytase works by hydrolyzing phytic acid, and numerous studies have documented that phytase supplementation increases phosphorus availability in fish fed diets with high inclusion levels of plant proteins. Plant derived proteins are increasingly used...... these effects, and the objective of the present study was to evaluate the effects of supplementing protease and pectinase to a diet containing approximately 30% soybean meal, rapeseed meal or sunflower meal on nutrient digestibility in juvenile rainbow trout (Oncorhynchus mykiss). Digestibility trials were...

Production by Tobacco Transplastomic Plants of Recombinant Fungal and Bacterial Cell-Wall Degrading Enzymes to Be Used for Cellulosic Biomass Saccharification

Directory of Open Access Journals (Sweden)

Paolo Longoni

2015-01-01

Full Text Available Biofuels from renewable plant biomass are gaining momentum due to climate change related to atmospheric CO2 increase. However, the production cost of enzymes required for cellulosic biomass saccharification is a major limiting step in this process. Low-cost production of large amounts of recombinant enzymes by transgenic plants was proposed as an alternative to the conventional microbial based fermentation. A number of studies have shown that chloroplast-based gene expression offers several advantages over nuclear transformation due to efficient transcription and translation systems and high copy number of the transgene. In this study, we expressed in tobacco chloroplasts microbial genes encoding five cellulases and a polygalacturonase. Leaf extracts containing the recombinant enzymes showed the ability to degrade various cell-wall components under different conditions, singly and in combinations. In addition, our group also tested a previously described thermostable xylanase in combination with a cellulase and a polygalacturonase to study the cumulative effect on the depolymerization of a complex plant substrate. Our results demonstrate the feasibility of using transplastomic tobacco leaf extracts to convert cell-wall polysaccharides into reducing sugars, fulfilling a major prerequisite of large scale availability of a variety of cell-wall degrading enzymes for biofuel industry.

Expression and characterization of plant aspartic protease nepenthesin-1 from Nepenthes gracilis.

Science.gov (United States)

Kadek, Alan; Tretyachenko, Vyacheslav; Mrazek, Hynek; Ivanova, Ljubina; Halada, Petr; Rey, Martial; Schriemer, David C; Man, Petr

2014-03-01

Carnivorous plants of the genus Nepenthes produce their own aspartic proteases, nepenthesins, to digest prey trapped in their pitchers. Nepenthesins differ significantly in sequence from other aspartic proteases in the animal or even plant kingdoms. This difference, which also brings more cysteine residues into the structure of these proteases, can be a cause of uniquely high temperature and pH stabilities of nepenthesins. Their detailed structure characterization, however, has not previously been possible due to low amounts of protease present in the pitcher fluid and also due to limited accessibility of Nepenthes plants. In the present study we describe a convenient way for obtaining high amounts of nepenthesin-1 from Nepenthes gracilis using heterologous production in Escherichia coli. The protein can be easily refolded in vitro and its characteristics are very close to those described for a natural enzyme isolated from the pitcher fluid. Similarly to the natural enzyme, recombinant nepenthesin-1 is sensitive to denaturing and reducing agents. It also has maximal activity around pH 2.5, shows unusual stability at high pH and its activity is not irreversibly inhibited even after prolonged incubation in the basic pH range. On the other hand, temperature stability of the recombinant enzyme is lower in comparison with the natural enzyme, which can be attributed to missing N-glycosylation in the recombinant protein. Copyright © 2013 Elsevier Inc. All rights reserved.

High throughput Screening to Identify Natural Human Monoamine Oxidase B Inhibitors

Science.gov (United States)

Mazzio, E; Deiab, S; Park, K; Soliman, KFA

2012-01-01

Age-related increase in monoamine oxidase B (MAO-B) may contribute to CNS neurodegenerative diseases. Moreover, MAO-B inhibitors are used in the treatment of idiopathic Parkinson disease as preliminary monotherapy or adjunct therapy with L-dopa. To date, meager natural sources of MAO-B inhibitors have been identified, and the relative strength, potency and rank of many plants relative to standard drugs such as Selegiline (L-deprenyl, Eldepryl) are not known. In this work, we developed and utilized a high throughput enzyme microarray format to screen and evaluate 905 natural product extracts (0.025–.7 mg/ml) to inhibit human MAO-B derived from BTI-TN-5B1-4 cells infected with recombinant baculovirus. The protein sequence of purified enzyme was confirmed using 1D gel electrophoresis-matrix assisted laser desorption ionization-time-of-flight-tandem mass spectroscopy, and enzyme activity was confirmed by [1] substrate conversion (3-mM benzylamine) to H202 and [2] benzaldehyde. Of the 905 natural extracts tested, the lowest IC50s [Comfrey, Bringraj, Skullcap, Kava-kava, Wild Indigo, Gentian and Green Tea. In conclusion, the data reflect relative potency information by rank of commonly used herbs and plants that contain human MAO-B inhibitory properties in their natural form. PMID:22887993

Compressed Natural Gas Technology for Alternative Fuel Power Plants

Science.gov (United States)

Pujotomo, Isworo

2018-02-01

Gas has great potential to be converted into electrical energy. Indonesia has natural gas reserves up to 50 years in the future, but the optimization of the gas to be converted into electricity is low and unable to compete with coal. Gas is converted into electricity has low electrical efficiency (25%), and the raw materials are more expensive than coal. Steam from a lot of wasted gas turbine, thus the need for utilizing exhaust gas results from gas turbine units. Combined cycle technology (Gas and Steam Power Plant) be a solution to improve the efficiency of electricity. Among other Thermal Units, Steam Power Plant (Combined Cycle Power Plant) has a high electrical efficiency (45%). Weakness of the current Gas and Steam Power Plant peak burden still using fuel oil. Compressed Natural Gas (CNG) Technology may be used to accommodate the gas with little land use. CNG gas stored in the circumstances of great pressure up to 250 bar, in contrast to gas directly converted into electricity in a power plant only 27 bar pressure. Stored in CNG gas used as a fuel to replace load bearing peak. Lawyer System on CNG conversion as well as the power plant is generally only used compressed gas with greater pressure and a bit of land.

Enzymes involved in organellar DNA replication in photosynthetic eukaryotes.

Science.gov (United States)

Moriyama, Takashi; Sato, Naoki

2014-01-01

Plastids and mitochondria possess their own genomes. Although the replication mechanisms of these organellar genomes remain unclear in photosynthetic eukaryotes, several organelle-localized enzymes related to genome replication, including DNA polymerase, DNA primase, DNA helicase, DNA topoisomerase, single-stranded DNA maintenance protein, DNA ligase, primer removal enzyme, and several DNA recombination-related enzymes, have been identified. In the reference Eudicot plant Arabidopsis thaliana, the replication-related enzymes of plastids and mitochondria are similar because many of them are dual targeted to both organelles, whereas in the red alga Cyanidioschyzon merolae, plastids and mitochondria contain different replication machinery components. The enzymes involved in organellar genome replication in green plants and red algae were derived from different origins, including proteobacterial, cyanobacterial, and eukaryotic lineages. In the present review, we summarize the available data for enzymes related to organellar genome replication in green plants and red algae. In addition, based on the type and distribution of replication enzymes in photosynthetic eukaryotes, we discuss the transitional history of replication enzymes in the organelles of plants.

Understanding drivers of peatland extracellular enzyme activity in the PEATcosm experiment: mixed evidence for enzymic latch hypothesis

Science.gov (United States)

Karl J. Romanowicz; Evan S. Kane; Lynette R. Potvin; Aleta L. Daniels; Randy Kolka; Erik A. Lilleskov

2015-01-01

Aims. Our objective was to assess the impacts of water table position and plant functional groups on peatland extracellular enzyme activity (EEA) framed within the context of the enzymic latch hypothesis. Methods. We utilized a full factorial experiment with 2 water table (WT) treatments (high and low) and 3 plant functional...

Does early use of enzyme replacement therapy alter the natural history of mucopolysaccharidosis I? Experience in three siblings.

Science.gov (United States)

Laraway, Sarah; Breen, Catherine; Mercer, Jean; Jones, Simon; Wraith, James E

2013-07-01

Enzyme replacement therapy is widely used as treatment for mucopolysaccharidosis I (MPS I), and there is evidence that this produces improvement in certain clinical domains. There does appear to be variation in the response of clinical features to treatment once these are established. In a reported sibling pair, when enzyme replacement therapy was commenced pre-symptomatically in the younger child, the natural history of the condition appeared to be affected. We present data from three siblings treated with enzyme replacement therapy at different ages which supports this finding. Copyright © 2013 Elsevier Inc. All rights reserved.

Variation in natural plant products and the attraction of bodyguards involved in indirect plant defense

NARCIS (Netherlands)

Mumm, R.; Dicke, M.

2010-01-01

Plants can respond to feeding or egg deposition by herbivorous arthropods by changing the volatile blend that they emit. These herbivore-induced plant volatiles (HIPVs) can attract carnivorous natural enemies of the herbivores, such as parasitoids and predators, a phenomenon that is called indirect

Biochemical studies on the effect of fluoride on higher plants. II. The effect of fluoride on sucrose-synthesizing enzymes from higher plants

Energy Technology Data Exchange (ETDEWEB)

Yang, S F; Miller, G W

1963-01-01

A study was initiated to characterize the properties of partially purified phosphoglucomutase, uridine diphosphate glucose pyrophosphorylase and uridine diphosphate glucose-fructose transglucosyalse, from various plant sources, with respect to activation by metal ions and inhibition by fluoride. Of the three enzymes studied, only phosphoglucomutase was very sensitive to fluoride. It is likely that the inhibition of sucrose synthesis in fluoride-fumigated plants might be due to the inhibition of phosphoglucomutase, which plays an important role in carbohydrate metabolism. However, at present, there is insufficient evidence to show the inhibition of phosphoglucomutase in vivo by fumigation with hydrogen fluoride.

Methods of natural gas liquefaction and natural gas liquefaction plants utilizing multiple and varying gas streams

Science.gov (United States)

Wilding, Bruce M; Turner, Terry D

2014-12-02

A method of natural gas liquefaction may include cooling a gaseous NG process stream to form a liquid NG process stream. The method may further include directing the first tail gas stream out of a plant at a first pressure and directing a second tail gas stream out of the plant at a second pressure. An additional method of natural gas liquefaction may include separating CO.sub.2 from a liquid NG process stream and processing the CO.sub.2 to provide a CO.sub.2 product stream. Another method of natural gas liquefaction may include combining a marginal gaseous NG process stream with a secondary substantially pure NG stream to provide an improved gaseous NG process stream. Additionally, a NG liquefaction plant may include a first tail gas outlet, and at least a second tail gas outlet, the at least a second tail gas outlet separate from the first tail gas outlet.

Evolution of plant parasitism in the phylum Nematoda.

Science.gov (United States)

Quist, Casper W; Smant, Geert; Helder, Johannes

2015-01-01

Within the species-rich and trophically diverse phylum Nematoda, at least four independent major lineages of plant parasites have evolved, and in at least one of these major lineages plant parasitism arose independently multiple times. Ribosomal DNA data, sequence information from nematode-produced, plant cell wall-modifying enzymes, and the morphology and origin of the style(t), a protrusible piercing device used to penetrate the plant cell wall, all suggest that facultative and obligate plant parasites originate from fungivorous ancestors. Data on the nature and diversification of plant cell wall-modifying enzymes point at multiple horizontal gene transfer events from soil bacteria to bacterivorous nematodes resulting in several distinct lineages of fungal or oomycete-feeding nematodes. Ribosomal DNA frameworks with sequence data from more than 2,700 nematode taxa combined with detailed morphological information allow for explicit hypotheses on the origin of agronomically important plant parasites, such as root-knot, cyst, and lesion nematodes.

Oligogalacturonide-mediated induction of a gene involved in jasmonic acid synthesis in response to the cell-wall-degrading enzymes of the plant pathogen Erwinia carotovora.

Science.gov (United States)

Norman, C; Vidal, S; Palva, E T

1999-07-01

Identification of Arabidopsis thaliana genes responsive to plant cell-wall-degrading enzymes of Erwinia carotovora subsp. carotovora led to the isolation of a cDNA clone with high sequence homology to the gene for allene oxide synthase, an enzyme involved in the biosynthesis of jasmonates. Expression of the corresponding gene was induced by the extracellular enzymes from this pathogen as well as by treatment with methyl jasmonate and short oligogalacturonides (OGAs). This suggests that OGAs are involved in the induction of the jasmonate pathway during plant defense response to E. carotovora subsp. carotovora attack.

Literature study of plants diversity in Sempu Island Nature Reserve, East Java

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RONY IRAWANTO

2017-03-01

Full Text Available Abstract. Irawanto R, Abywijaya IK, Mudiana D. 2017. Literature study of plants diversity in Sempu Island Nature Reserve, East Java. Pros Sem Nas Masy Biodiv Indon 3: 138-146. Purwodadi Botanic Garden have the task of plant conservation through inventories, exploration, collection and maintenance of plants, especially on dry lowland plants. Exploration activities and plants collection aim to conserve and save the plants from extinction, as well as conduct research and documentation of plant diversity in a region. It's related of the global strategy for plant conservation (GSPC target is known and documentation of plants diversity, especially in threatened habitats could be a priority. Sempu island's status as a nature reserve has a diversity of ecosystem and biodiversity of flora and fauna that are endemic and unique. This study aims to determine the plant's diversity in Island Sempu Nature Reserve based on a literature review of various studies that have been done. This study is a database for planning exploration activities, collecting, and documenting the plant's diversity in Sempu Island - East Java. Based on the literature review there are 282 species of plant diversity in Sempu Island, included in 80 families, contained in 10 blocks/location areas, namely Telaga Lele, Telaga Sat, Telaga Dowo, Gladakan, Baru-baru, Gua Macan, Teluk Ra’as, Teluk Semut, Air Tawar, dan Waru-Waru.Tenth blocks represent plants vegetation of mangrove forest, coastal forest, lowland tropical forests, and meadows.

Rivina humilis L. (Phytolaccaceae, a Newly Naturalized Plant in Taiwan

Directory of Open Access Journals (Sweden)

Yen-Hsueh Tseng

2008-12-01

Full Text Available A newly naturalized plant, Rivina humilis L., was found recently in the central part of Taiwan. This plant represents a new record of this genus and species for Taiwan. This Neotropical plant, native to the southern USA, Mexico, the Caribbean islands, and Central and South America, is described and illustrated in this report.

In vitro inhibitory activities of selected Australian medicinal plant extracts against protein glycation, angiotensin converting enzyme (ACE) and digestive enzymes linked to type II diabetes.

Science.gov (United States)

Deo, Permal; Hewawasam, Erandi; Karakoulakis, Aris; Claudie, David J; Nelson, Robert; Simpson, Bradley S; Smith, Nicholas M; Semple, Susan J

2016-11-04

There is a need to develop potential new therapies for the management of diabetes and hypertension. Australian medicinal plants collected from the Kuuku I'yu (Northern Kaanju) homelands, Cape York Peninsula, Queensland, Australia were investigated to determine their therapeutic potential. Extracts were tested for inhibition of protein glycation and key enzymes relevant to the management of hyperglycaemia and hypertension. The inhibitory activities were further correlated with the antioxidant activities. Extracts of five selected plant species were investigated: Petalostigma pubescens, Petalostigma banksii, Memecylon pauciflorum, Millettia pinnata and Grewia mesomischa. Enzyme inhibitory activity of the plant extracts was assessed against α-amylase, α-glucosidase and angiotensin converting enzyme (ACE). Antiglycation activity was determined using glucose-induced protein glycation models and formation of protein-bound fluorescent advanced glycation endproducts (AGEs). Antioxidant activity was determined by measuring the scavenging effect of plant extracts against 1, 1-diphenyl-2-picryl hydrazyl (DPPH) and using the ferric reducing anti-oxidant potential assay (FRAP). Total phenolic and flavonoid contents were also determined. Extracts of the leaves of Petalostigma banksii and P. pubescens showed the strongest inhibition of α-amylase with IC 50 values of 166.50 ± 5.50 μg/mL and 160.20 ± 27.92 μg/mL, respectively. The P. pubescens leaf extract was also the strongest inhibitor of α-glucosidase with an IC 50 of 167.83 ± 23.82 μg/mL. Testing for the antiglycation potential of the extracts, measured as inhibition of formation of protein-bound fluorescent AGEs, showed that P. banksii root and fruit extracts had IC 50 values of 34.49 ± 4.31 μg/mL and 47.72 ± 1.65 μg/mL, respectively, which were significantly lower (p < 0.05) than other extracts. The inhibitory effect on α-amylase, α-glucosidase and the antiglycation potential of

Effects of uranium on soil microbial biomass carbon, enzymes, plant biomass and microbial diversity in yellow soils

International Nuclear Information System (INIS)

Yan, X.; Zhang, Y.; Luo, X.; Yu, L.

2016-01-01

We conducted an experiment to investigate the effects of uranium (U) on soil microbial biomass carbon (MBC), enzymes, plant biomass and microbial diversity in yellow soils under three concentrations: 0 mg kg"-"1 (T1, control), 30 mg kg"-"1 (T2) and 60 mg kg"-"1 (T3). Under each treatment, elevated U did not reduce soil MBC or plant biomass, but inhibited the activity of the soil enzymes urease (UR), dehydrogenase (DH) and phosphatase (PHO). The microbial diversity was different, with eight dominant phyla in T1 and six in T2 and T3. Furthermore, Proteobacteria and material X were both detected in each treatment site (T1, T2 and T3). Pseudomonas sp. was the dominant strain, followed by Acidiphilium sp. This initial study provided valuable data for further research toward a better understanding of U contamination in yellow soils in China. (authors)

Metabolic Engineering Strategies for the Optimization of Medicinal and Aromatic Plants : Expectations and Realities

NARCIS (Netherlands)

Kayser, O.; Baricevic, D; Novak, J; Pank, F

2010-01-01

In recent years classic genetic and molecular biology strategies (Bioballistics, Agrobacterium tumefaciens transformation, recombinant enzymes) for production of natural compounds or even breeding of medicinal and aromatic plants have expanded and improved productivity of plant-derived fine

Production of plant cell wall degrading enzymes by monoculture and co-culture of Aspergillus niger and Aspergillus terreus under SSF of banana peels

Directory of Open Access Journals (Sweden)

Shazia Rehman

2014-12-01

Full Text Available Filamentous fungi are considered to be the most important group of microorganisms for the production of plant cell wall degrading enzymes (CWDE, in solid state fermentations. In this study, two fungal strains Aspergillus niger MS23 and Aspergillus terreus MS105 were screened for plant CWDE such as amylase, pectinase, xylanase and cellulases (β-glucosidase, endoglucanase and filterpaperase using a novel substrate, Banana Peels (BP for SSF process. This is the first study, to the best of our knowledge, to use BP as SSF substrate for plant CWDE production by co-culture of fungal strains. The titers of pectinase were significantly improved in co-culture compared to mono-culture. Furthermore, the enzyme preparations obtained from monoculture and co-culture were used to study the hydrolysis of BP along with some crude and purified substrates. It was observed that the enzymatic hydrolysis of different crude and purified substrates accomplished after 26 h of incubation, where pectin was maximally hydrolyzed by the enzyme preparations of mono and co-culture. Along with purified substrates, crude materials were also proved to be efficiently degraded by the cocktail of the CWDE. These results demonstrated that banana peels may be a potential substrate in solid-state fermentation for the production of plant cell wall degrading enzymes to be used for improving various biotechnological and industrial processes.

Production of plant cell wall degrading enzymes by monoculture and co-culture of Aspergillus niger and Aspergillus terreus under SSF of banana peels.

Science.gov (United States)

Rehman, Shazia; Aslam, Hina; Ahmad, Aqeel; Khan, Shakeel Ahmed; Sohail, Muhammad

2014-01-01

Filamentous fungi are considered to be the most important group of microorganisms for the production of plant cell wall degrading enzymes (CWDE), in solid state fermentations. In this study, two fungal strains Aspergillus niger MS23 and Aspergillus terreus MS105 were screened for plant CWDE such as amylase, pectinase, xylanase and cellulases (β-glucosidase, endoglucanase and filterpaperase) using a novel substrate, Banana Peels (BP) for SSF process. This is the first study, to the best of our knowledge, to use BP as SSF substrate for plant CWDE production by co-culture of fungal strains. The titers of pectinase were significantly improved in co-culture compared to mono-culture. Furthermore, the enzyme preparations obtained from monoculture and co-culture were used to study the hydrolysis of BP along with some crude and purified substrates. It was observed that the enzymatic hydrolysis of different crude and purified substrates accomplished after 26 h of incubation, where pectin was maximally hydrolyzed by the enzyme preparations of mono and co-culture. Along with purified substrates, crude materials were also proved to be efficiently degraded by the cocktail of the CWDE. These results demonstrated that banana peels may be a potential substrate in solid-state fermentation for the production of plant cell wall degrading enzymes to be used for improving various biotechnological and industrial processes.

Characterization of Sugar Contents and Sucrose Metabolizing Enzymes in Developing Leaves of Hevea brasiliensis

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Jinheng Zhu

2018-02-01

Full Text Available Sucrose-metabolizing enzymes in plant leaves have hitherto been investigated mainly in temperate plants, and rarely conducted in tandem with gene expression and sugar analysis. Here, we investigated the sugar content, gene expression, and the activity of sucrose-metabolizing enzymes in the leaves of Hevea brasiliensis, a tropical tree widely cultivated for natural rubber. Sucrose, fructose and glucose were the major sugars detected in Hevea leaves at four developmental stages (I to IV, with starch and quebrachitol as minor saccharides. Fructose and glucose contents increased until stage III, but decreased strongly at stage IV (mature leaves. On the other hand, sucrose increased continuously throughout leaf development. Activities of all sucrose-cleaving enzymes decreased markedly at maturation, consistent with transcript decline for most of their encoding genes. Activity of sucrose phosphate synthase (SPS was low in spite of its high transcript levels at maturation. Hence, the high sucrose content in mature leaves was not due to increased sucrose-synthesizing activity, but more to the decline in sucrose cleavage. Gene expression and activities of sucrose-metabolizing enzymes in Hevea leaves showed striking differences compared with other plants. Unlike in most other species where vacuolar invertase predominates in sucrose cleavage in developing leaves, cytoplasmic invertase and sucrose synthase (cleavage direction also featured prominently in Hevea. Whereas SPS is normally responsible for sucrose synthesis in plant leaves, sucrose synthase (synthesis direction was comparable or higher than that of SPS in Hevea leaves. Mature Hevea leaves had an unusually high sucrose:starch ratio of about 11, the highest reported to date in plants.

Natural Antioxidants in Foods and Medicinal Plants: Extraction, Assessment and Resources

OpenAIRE

Xu, Dong-Ping; Li, Ya; Meng, Xiao; Zhou, Tong; Zhou, Yue; Zheng, Jie; Zhang, Jiao-Jiao; Li, Hua-Bin

2017-01-01

Natural antioxidants are widely distributed in food and medicinal plants. These natural antioxidants, especially polyphenols and carotenoids, exhibit a wide range of biological effects, including anti-inflammatory, anti-aging, anti-atherosclerosis and anticancer. The effective extraction and proper assessment of antioxidants from food and medicinal plants are crucial to explore the potential antioxidant sources and promote the application in functional foods, pharmaceuticals and food additive...

Induced and constitutive responses of digestive enzymes to plant toxins in an herbivorous mammal.

Science.gov (United States)

Kohl, Kevin D; Dearing, M Denise

2011-12-15

Many plants produce plant secondary compounds (PSCs) that bind and inhibit the digestive enzymes of herbivores, thus limiting digestibility for the herbivore. Herbivorous insects employ several physiological responses to overcome the anti-nutritive effects of PSCs. However, studies in vertebrates have not shown such responses, perhaps stemming from the fact that previously studied vertebrates were not herbivorous. The responses of the digestive system to dietary PSCs in populations of Bryant's woodrat (Neotoma bryanti) that vary in their ecological and evolutionary experience with the PSCs in creosote bush (Larrea tridentata) were compared. Individuals from naïve and experienced populations were fed diets with and without added creosote resin. Animals fed diets with creosote resin had higher activities of pancreatic amylase, as well as luminal amylase and chymotrypsin, regardless of prior experience with creosote. The experienced population showed constitutively higher activities of intestinal maltase and sucrase. Additionally, the naïve population produced an aminopeptidase-N enzyme that was less inhibited by creosote resin when feeding on the creosote resin diet, whereas the experienced population constitutively expressed this form of aminopeptidase-N. Thus, the digestive system of an herbivorous vertebrate responds significantly to dietary PSCs, which may be important for allowing herbivorous vertebrates to feed on PSC-rich diets.

Cultivation of Podospora anserina on soybean hulls results in an efficient enzyme cocktail for plant biomass hydrolysis

NARCIS (Netherlands)

Mäkelä, Miia R; Bouzid, Ourdia; Ruiz-Robleto, J.; Post, Harm|info:eu-repo/dai/nl/341667374; Peng, Mao; Heck, Albert|info:eu-repo/dai/nl/105189332; Altelaar, Maarten|info:eu-repo/dai/nl/304833517; de Vries, Ronald P|info:eu-repo/dai/nl/186324960

2017-01-01

The coprophilic ascomycete fungus Podospora anserina was cultivated on three different plant biomasses, i.e. cotton seed hulls (CSH), soybean hulls (SBH) and acid-pretreated wheat straw (WS) for four days, and the potential of the produced enzyme mixtures was compared in the enzymatic

Brassinosteroids improve photosystem II efficiency, gas exchange, antioxidant enzymes and growth of cowpea plants exposed to water deficit.

Science.gov (United States)

Lima, J V; Lobato, A K S

2017-01-01

Water deficit is considered the main abiotic stress that limits agricultural production worldwide. Brassinosteroids (BRs) are natural substances that play roles in plant tolerance against abiotic stresses, including water deficit. This research aims to determine whether BRs can mitigate the negative effects caused by water deficiency, revealing how BRs act and their possible contribution to increased tolerance of cowpea plants to water deficit. The experiment was a factorial design with the factors completely randomised, with two water conditions (control and water deficit) and three levels of brassinosteroids (0, 50 and 100 nM 24-epibrassinolide; EBR is an active BRs). Plants sprayed with 100 nM EBR under the water deficit presented significant increases in Φ PSII , q P and ETR compared with plants subjected to the water deficit without EBR. With respect to gas exchange, P N , E and g s exhibited significant reductions after water deficit, but application of 100 nM EBR caused increases in these variables of 96, 24 and 33%, respectively, compared to the water deficit + 0 nM EBR treatment. To antioxidant enzymes, EBR resulted in increases in SOD, CAT, APX and POX, indicating that EBR acts on the antioxidant system, reducing cell damage. The water deficit caused significant reductions in Chl a , Chl b and total Chl, while plants sprayed with 100 nM EBR showed significant increases of 26, 58 and 33% in Chl a , Chl b and total Chl, respectively. This study revealed that EBR improves photosystem II efficiency, inducing increases in Φ PSII , q P and ETR. This substance also mitigated the negative effects on gas exchange and growth induced by the water deficit. Increases in SOD, CAT, APX and POX of plants treated with EBR indicate that this steroid clearly increased the tolerance to the water deficit, reducing reactive oxygen species, cell damage, and maintaining the photosynthetic pigments. Additionally, 100 nM EBR resulted in a better dose-response of cowpea

Report: screening of selected medicinal plants for their enzyme inhibitory potential - a validation of their ethnopharmacological uses.

Science.gov (United States)

Khuda, Fazli; Iqbal, Zafar; Khan, Ayub; Zakiullah; Shah, Yasar; Khan, Abad

2014-05-01

In present study four medicinal plants namely Valeriana wallichii, Xanthium strumarium, Achyranthes aspera and Duchesnea indica belonging to different families were collected in Khyber Pakhtunkhwa province and crude extract and subsequent fractions were analyzed for their inhibitory potential against acetylcholinesterase, butyrylcholinesterase and α-glucosidase enzymes. Valeriana wallichii, Xanthium strumarium and Achyranthes aspera were significantly active against cholinesterases. Chloroform and ethylacetate fractions of Valeriana wallichii exhibited significant activity against acetylcholinesterase (IC50: 61μg/ml) and butyrylcholinesterase enzymes (IC50: 58μg/ml), respectively. Similarly ethylacetate fraction of Achyranthes aspera showed significant activity against acetylcholinesterase (IC50: 61 μg/ml) and butyrylcholinesterase enzymes (IC50: 61 μg/ml), respectively. In case of α-glucosidase enzyme, the chloroform fraction of Xanthium strumarium exhibited significant inhibitory activity (IC50: 72 μg/ml) as compared to the standard compound acarbose (IC50: 483 μg/ml). Duchesnea indica showed no such activities.

Hexose kinases and their role in sugar-sensing and plant development

Directory of Open Access Journals (Sweden)

David eGranot

2013-03-01

Full Text Available Hexose sugars, such as glucose and fructose produced in plants, are ubiquitous in most organisms and are the origin of most of the organic matter found in nature. To be utilized, hexose sugars must first be phosphorylated. The central role of hexose-phosphorylating enzymes has attracted the attention of many researchers, leading to novel discoveries. Only two families of enzymes capable of phosphorylating glucose and fructose have been identified in plants; hexokinases (HXKs and fructokinases (FRKs. Intensive investigations of these two families in numerous plant species have yielded a wealth of knowledge regarding the genes number, enzymatic characterization, intracellular localization and developmental and physiological roles of several HXKs and FRKs. The emerging picture indicates that HXK and FRK enzymes found at specific intracellular locations play distinct roles in plant metabolism and development. Individual HXKs were shown for the first time to be dual-function enzymes - sensing sugar levels independent of their catalytic activity and also controlling gene expression and major developmental pathways, as well as hormonal interactions. FRK, on the other hand, seems to play a central metabolic role in vascular tissues, controlling the amounts of sugars allocated for vascular development. While a clearer picture of the roles of these two types of enzymes is emerging, many questions remain unsolved, such as the specific tissues and types of cells in which these enzymes function, the roles of individual HXK and FRK genes, and how these enzymes interact with hormones in the regulation of developmental processes. It is anticipated that ongoing efforts will broaden our knowledge of these important plant enzymes and their potential uses in the modification of plant traits.

Deciphering the factors associated with the colonization of rice plants by cyanobacteria.

Science.gov (United States)

Bidyarani, Ngangom; Prasanna, Radha; Chawla, Gautam; Babu, Santosh; Singh, Rajendra

2015-04-01

Cyanobacteria-rice plant interactions were analyzed using a hydroponics experiment. The activity of plant defense and pathogenesis-related enzymes, scanning electron microscopy, growth, nitrogen fixation (measured as ARA), and DNA fingerprinting assays proved useful in illustrating the nature of associations of cyanobacteria with rice plants. Microscopic analyses revealed the presence of short filaments and coiled masses of filaments of cyanobacteria near the epidermis and cortex of roots and shoot tissues. Among the six cyanobacterial strains employed, Calothrix sp. (RPC1), Anabaena laxa (RPAN8), and Anabaena azollae (C16) were the best performing strains, in terms of colonization in roots and stem. These strains also enhanced nitrogen fixation and stimulated the activity of plant defense/cell wall-degrading enzymes. A significantly high correlation was also recorded between the elicited plant enzymes, growth, and ARA. DNA fingerprinting using highly iterated palindromic sequences (HIP-TG) further helped in proving the establishment of inoculated organisms in the roots/shoots of rice plants. This study illustrated that the colonization of cyanobacteria in the plant tissues is facilitated by increased elicitation of plant enzymes, leading to improved plant growth, nutrient mobilization, and enhanced plant fitness. Such strains can be promising candidates for developing "cyanobacteria colonized-nitrogen-fixing rice plants" in the future. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Research progress of nanoparticles as enzyme mimetics

Science.gov (United States)

Hu, XiaoNa; Liu, JianBo; Hou, Shuai; Wen, Tao; Liu, WenQi; Zhang, Ke; He, WeiWei; Ji, YingLu; Ren, HongXuan; Wang, Qi; Wu, XiaoChun

2011-10-01

Natural enzymes as biological catalysts possess remarkable advantages, especially their highly efficient and selective catalysis under mild conditions. However, most natural enzymes are proteins, thus exhibiting an inherent low durability to harsh reaction conditions. Artificial enzyme mimetics have been pursued extensively to avoid this drawback. Quite recently, some inorganic nanoparticles (NPs) have been found to exhibit unique enzyme mimetics. In addition, their much higher stability overcomes the inherent disadvantage of natural enzymes. Furthermore, easy mass-production and low cost endow them more benefits. As a new member of artificial enzyme mimetics, they have received intense attention. In this review article, major progress in this field is summarized and future perspectives are highlighted.

[POLYMORPHISM OF ALFA-AMYLASE AND CONJUGATION IN COMMON WHEAT ENZYME TYPES WITH QUANTITATIVE TRAITS OF PLANTS].

Science.gov (United States)

Netsvetaev, V P; Bondarenko, L S; Motorina, I P

2015-01-01

Using polymorphism of alpha-amylase in the winter common wheat studied inheritance isoenzymes and its conjugation enzyme types with germinating grain on the "vine", grain productivity, plant height and time of ear formation. It is shown that the polymorphism isoenzyme of alpha-amylase wheat is limited by the presence of different loci whose products are similar in electrophoretic parameters. In this regard, one component of the enzyme can be controlling at one or two or three genes. Identification of a locus controlling alpha-amylase isoenzyme in the fast moving part of the electrophoretogram, designated as α-Amy-B7. Determine the distance of the locus to factor α-Amy-B6.

Transgenerational Effects Alter Plant Defense and Resistance in Nature

Science.gov (United States)

Colicchio, Jack

2017-01-01

Trichomes, or leaf hairs, are epidermal extensions that take a variety of forms and perform many functions in plants, including herbivore defense. In this study, I document genetically determined variation, within-generation plasticity, and a direct role of trichomes in herbivore defense for Mimulus guttatus. After establishing the relationship between trichomes and herbivory, I test for transgenerational effects of wounding on trichome density and herbivore resistance. Patterns of inter-annual variation in herbivore density and the high cost of plant defense makes plant-herbivore interactions a system in which transgenerational phenotypic plasticity (TPP) is apt to evolve. Here, I demonstrate that parental damage alters offspring trichome density and herbivore resistance in nature. Moreover, this response varies between populations. This is among the first studies to demonstrate that TPP contributes to variation in nature, and also suggests that selection can modify TPP in response to local conditions. PMID:28102915

Metagenomic insights into the rumen microbial fibrolytic enzymes in Indian crossbred cattle fed finger millet straw.

Science.gov (United States)

Jose, V Lyju; Appoothy, Thulasi; More, Ravi P; Arun, A Sha

2017-12-01

The rumen is a unique natural habitat, exhibiting an unparalleled genetic resource of fibrolytic enzymes of microbial origin that degrade plant polysaccharides. The objectives of this study were to identify the principal plant cell wall-degrading enzymes and the taxonomic profile of rumen microbial communities that are associated with it. The cattle rumen microflora and the carbohydrate-active enzymes were functionally classified through a whole metagenomic sequencing approach. Analysis of the assembled sequences by the Carbohydrate-active enzyme analysis Toolkit identified the candidate genes encoding fibrolytic enzymes belonging to different classes of glycoside hydrolases(11,010 contigs), glycosyltransferases (6366 contigs), carbohydrate esterases (4945 contigs), carbohydrate-binding modules (1975 contigs), polysaccharide lyases (480 contigs), and auxiliary activities (115 contigs). Phylogenetic analysis of CAZyme encoding contigs revealed that a significant proportion of CAZymes were contributed by bacteria belonging to genera Prevotella, Bacteroides, Fibrobacter, Clostridium, and Ruminococcus. The results indicated that the cattle rumen microbiome and the CAZymes are highly complex, structurally similar but compositionally distinct from other ruminants. The unique characteristics of rumen microbiota and the enzymes produced by resident microbes provide opportunities to improve the feed conversion efficiency in ruminants and serve as a reservoir of industrially important enzymes for cellulosic biofuel production.

Comparative evaluation of Bacillus licheniformis 5A5 and Aloe variegata milk-clotting enzymes

Directory of Open Access Journals (Sweden)

S. A. Ahmed

2012-03-01

Full Text Available The properties of a milk clotting enzyme (MCE produced by bacteria (Bacillus licheniformis 5A5 were investigated and compared to those of rennet extracted from a plant (Aloe variegata. Production of MCE by B. licheniformis 5A5 was better in static than in shaken cultures. Maximum activity (98.3 and 160.3 U/ml of clotting was obtained at 75ºC and 80ºC with bacterial and plant rennet, respectively. In the absence of substrate, the clotting activity of Aloe MCE was found to be less sensitive to heat inactivation up to 80ºC for 75 min, retaining 63.8% of its activity, while bacterial MCE was completely inhibited. CaCl2 stimulated milk clotting activity (MCA up to 2% and 1.5% for bacterial and plant enzymes. NaCl inhibited MCA for both enzymes, even at low concentration (1%. Plant MCE was more sensitive to NaCl at 3% concentration it retained 30.2% of its activity, whereas bacterial MCE retained 64.1%. Increasing skim milk concentration caused a significant increase in MCA up to 6% for both enzymes. Mn2+ stimulated the activity of bacterial and plant enzymes to 158.6 and 177.9%, respectively. EDTA and PMSF increased the activity of plant MCE by 34.4 and 41.1%, respectively, which is higher than those for the bacterial MCE (19.1 and 20.9%. Some natural materials activated MCE, the highest activation of bacterial MCE (128.1% was obtained in the presence of Fenugreek (with acid extraction. However Lupine Giza 1 (with neutral extraction gave the highest activation of plant MCE (137.9%. All extracts from Neem plant increased MCA at range from 105.6% to 136.4%. Plant MCE exhibited much better stability when stored at room temperature (25-30ºC for 30 days, retaining 51.2% of its activity. Bacterial MCE was highly stabile when stored under freezing (-18ºC, retaining 100% of its activity after 30 days. Moreover, bacterial MCE was highly tolerant to repeated freezing and thawing without loss of activity for 8 months.

NORM emissions from heavy oil and natural gas fired power plants in Syria

International Nuclear Information System (INIS)

Al-Masri, M.S.; Haddad, Kh.

2012-01-01

Naturally occurring radioactive materials (NORM) have been determined in fly and bottom ash collected from four major Syrian power plants fired by heavy oil and natural gas. 210 Pb and 210 Po were the main NORM radionuclides detected in the fly and bottom ash. 210 Pb activity concentrations have reached 3393 ± 10 Bq kg −1 and 4023 ± 7 Bq kg −1 in fly ash and bottom ash, respectively; lower values of 210 Po were observed due to its high volatility. In addition, 210 Po and 210 Pb annual emissions in bottom ash from mixed (heavy oil and natural gas) fired power plants varied between 2.7 × 10 9 –7.95 × 10 9 Bq and 3.5 × 10 9 –10 10 Bq, respectively; higher emissions of 210 Po and 210 Pb from gas power plants being observed. However, the present study showed that 210 Po and 210 Pb emissions from thermal power plants fired by natural gas are much higher than the coal power plants operated in the World. - Highlights: ► NORM have been determined in fly and bottom ash collected from Syrian power plants fired by heavy oil and natural gas. ► 210 Pb and 210 Po were the main NORM radionuclides detected in the fly and bottom ash. ► 210 Po and 210 Pb annual emissions from these power plants were estimated.

Natural Ecosystem Surrounding a Conventional Banana Crop Improves Plant Health and Fruit Quality

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Florence P. Castelan

2018-06-01

Full Text Available Natural ecosystems near agricultural landscapes may provide rich environments for growing crops. However, the effect of a natural ecosystem on crop health and fruit quality is poorly understood. In the present study, it was investigated whether the presence of a natural ecosystem surrounding a crop area influences banana plant health and fruit postharvest behavior. Plants from two conventional banana crop areas with identical planting time and cultural practices were used; the only difference between banana crop areas is that one area was surrounded by a natural forest (Atlantic forest fragment (Near-NF, while the other area was inserted at the center of a conventional banana crop (Distant-NF. Results showed that bananas harvested from Near-NF showed higher greenlife and a more homogeneous profile during ripening compared to fruits harvested from Distant-NF. Differences in quality parameters including greenlife, carbohydrate profile, and pulp firmness between fruits harvested from Near-NF and Distant-NF are explained, at least partly, by differences in the balance of plant growth regulators (indole-3-acetic acid and abscisic acid in bananas during ripening. Furthermore, plants from Near-NF showed a lower severity index of black leaf streak disease (BLSD and higher levels of phenolic compounds in leaves compared to plants from Distant-NF. Together, the results provide additional evidence on how the maintenance of natural ecosystems near conventional crop areas could be a promising tool to improve plant health and fruit quality.

From phenotypic to molecular polymorphisms involved in naturally occurring variation for plant development

NARCIS (Netherlands)

Alonso-Blanco, C.; Mendez-Vigo, B.; Koornneef, M.

2005-01-01

An enormous amount of naturally occurring genetic variation affecting development is found within wild and domesticated plant species. This diversity is presumably involved in plant adaptation to different natural environments or in human preferences. In addition, such intraspecific variation

The family of berberine bridge enzyme-like enzymes: A treasure-trove of oxidative reactions.

Science.gov (United States)

Daniel, Bastian; Konrad, Barbara; Toplak, Marina; Lahham, Majd; Messenlehner, Julia; Winkler, Andreas; Macheroux, Peter

2017-10-15

Biological oxidations form the basis of life on earth by utilizing organic compounds as electron donors to drive the generation of metabolic energy carriers, such as ATP. Oxidative reactions are also important for the biosynthesis of complex compounds, i.e. natural products such as alkaloids that provide vital benefits for organisms in all kingdoms of life. The vitamin B 2 -derived cofactors flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD) enable an astonishingly diverse array of oxidative reactions that is based on the versatility of the redox-active isoalloxazine ring. The family of FAD-linked oxidases can be divided into subgroups depending on specific sequence features in an otherwise very similar structural context. The sub-family of berberine bridge enzyme (BBE)-like enzymes has recently attracted a lot of attention due to the challenging chemistry catalyzed by its members and the unique and unusual bi-covalent attachment of the FAD cofactor. This family is the focus of the present review highlighting recent advancements into the structural and functional aspects of members from bacteria, fungi and plants. In view of the unprecedented reaction catalyzed by the family's namesake, BBE from the California poppy, recent studies have provided further insights into nature's treasure chest of oxidative reactions. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Climate change will increase the naturalization risk from garden plants in Europe.

Science.gov (United States)

Dullinger, Iwona; Wessely, Johannes; Bossdorf, Oliver; Dawson, Wayne; Essl, Franz; Gattringer, Andreas; Klonner, Günther; Kreft, Holger; Kuttner, Michael; Moser, Dietmar; Pergl, Jan; Pyšek, Petr; Thuiller, Wilfried; van Kleunen, Mark; Weigelt, Patrick; Winter, Marten; Dullinger, Stefan; Beaumont, Linda

2017-01-01

Plant invasions often follow initial introduction with a considerable delay. The current non-native flora of a region may hence contain species that are not yet naturalized but may become so in the future, especially if climate change lifts limitations on species spread. In Europe, non-native garden plants represent a huge pool of potential future invaders. Here, we evaluate the naturalization risk from this species pool and how it may change under a warmer climate. Europe. We selected all species naturalized anywhere in the world but not yet in Europe from the set of non-native European garden plants. For this subset of 783 species, we used species distribution models to assess their potential European ranges under different scenarios of climate change. Moreover, we defined geographical hotspots of naturalization risk from those species by combining projections of climatic suitability with maps of the area available for ornamental plant cultivation. Under current climate, 165 species would already find suitable conditions in > 5% of Europe. Although climate change substantially increases the potential range of many species, there are also some that are predicted to lose climatically suitable area under a changing climate, particularly species native to boreal and Mediterranean biomes. Overall, hotspots of naturalization risk defined by climatic suitability alone, or by a combination of climatic suitability and appropriate land cover, are projected to increase by up to 102% or 64%, respectively. Our results suggest that the risk of naturalization of European garden plants will increase with warming climate, and thus it is very likely that the risk of negative impacts from invasion by these plants will also grow. It is therefore crucial to increase awareness of the possibility of biological invasions among horticulturalists, particularly in the face of a warming climate.

The potential medicinal value of plants from Asteraceae family with antioxidant defense enzymes as biological targets.

Science.gov (United States)

Koc, Suheda; Isgor, Belgin S; Isgor, Yasemin G; Shomali Moghaddam, Naznoosh; Yildirim, Ozlem

2015-05-01

Plants and most of the plant-derived compounds have long been known for their potential pharmaceutical effects. They are well known to play an important role in the treatment of several diseases from diabetes to various types of cancers. Today most of the clinically effective pharmaceuticals are developed from plant-derived ancestors in the history of medicine. The aim of this study was to evaluate the free radical scavenging activity and total phenolic and flavonoid contents of methanol, ethanol, and acetone extracts from flowers and leaves of Onopordum acanthium L., Carduus acanthoides L., Cirsium arvense (L.) Scop., and Centaurea solstitialis L., all from the Asteraceae family, for investigating their potential medicinal values of biological targets that are participating in the antioxidant defense system such as catalase (CAT), glutathione S-transferase (GST), and glutathione peroxidase (GPx). In this study, free radical scavenging activity and total phenolic and flavonoid contents of the plant samples were assayed by DPPH, Folin-Ciocalteu, and aluminum chloride colorimetric methods. Also, the effects of extracts on CAT, GST, and GPx enzyme activities were investigated. The highest phenolic and flavonoid contents were detected in the acetone extract of C. acanthoides flowers, with 90.305 mg GAE/L and 185.43 mg Q/L values, respectively. The highest DPPH radical scavenging was observed with the methanol leaf extracts of C. arvense with an IC50 value of 366 ng/mL. The maximum GPx and GST enzyme inhibition activities were observed with acetone extracts from the flower of C. solstitialis with IC50 values of 79 and 232 ng/mL, respectively.

Exploring the Potential for Using Inexpensive Natural Reagents Extracted from Plants to Teach Chemical Analysis

Science.gov (United States)

Hartwell, Supaporn Kradtap

2012-01-01

A number of scientific articles report on the use of natural extracts from plants as chemical reagents, where the main objective is to present the scientific applications of those natural plant extracts. The author suggests that natural reagents extracted from plants can be used as alternative low cost tools in teaching chemical analysis,…

Transgenerational effects alter plant defence and resistance in nature.

Science.gov (United States)

Colicchio, J

2017-04-01

Trichomes, or leaf hairs, are epidermal extensions that take a variety of forms and perform many functions in plants, including herbivore defence. In this study, I document genetically determined variation, within-generation plasticity, and a direct role of trichomes in herbivore defence for Mimulus guttatus. After establishing the relationship between trichomes and herbivory, I test for transgenerational effects of wounding on trichome density and herbivore resistance. Patterns of interannual variation in herbivore density and the high cost of plant defence makes plant-herbivore interactions a system in which transgenerational phenotypic plasticity (TPP) is apt to evolve. Here, I demonstrate that parental damage alters offspring trichome density and herbivore resistance in nature. Moreover, this response varies between populations. This is among the first studies to demonstrate that TPP contributes to variation in nature, and also suggests that selection can modify TPP in response to local conditions. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

[Plants as a source of natural harmful substances].

Science.gov (United States)

Czerwiecki, Ludwik

2005-01-01

In this review the several data concerning phytotoxins as natural harmful substances of plants and phycotoxins--toxicants of algae were described. For example plants are source of pyrrolizidine alkaloids, glycoalkaloids, glucosinolates as well as glycosides, saponine and psolarens. Possible adverse effects of phytoestrogens as endocrine disruptors versus beneficial influence these substances on human organism were mentioned. About lectins as possible factors of some diseases was reported, as well as some proteins as allergens of soy and peanuts was mentioned. Accumulated by shellfish and fish the most important phycotoxins such as saxitoxin, okadaic acid, brevetoxins and ciguatoxins were described. Phycotoxins produced several poisoning symptoms. Microcystins and nodularin--cyanobacterial phycotoxins of freshwater, was mentioned. In conclusion, the need of limitation of permissible levels of some plant toxicants, development of analytical methods as well as knowledge of influence of some technological processes on toxic plant substances was highlighted. The importance of balanced diet as a tool of defense against plant toxicants was concluded.

Biosynthetic Pathway and Metabolic Engineering of Plant Dihydrochalcones.

Science.gov (United States)

Ibdah, Mwafaq; Martens, Stefan; Gang, David R

2018-03-14

Dihydrochalcones are plant natural products containing the phenylpropanoid backbone and derived from the plant-specific phenylpropanoid pathway. Dihydrochalcone compounds are important in plant growth and response to stresses and, thus, can have large impacts on agricultural activity. In recent years, these compounds have also received increased attention from the biomedical community for their potential as anticancer treatments and other benefits for human health. However, they are typically produced at relatively low levels in plants. Therefore, an attractive alternative is to express the plant biosynthetic pathway genes in microbial hosts and to engineer the metabolic pathway/host to improve the production of these metabolites. In the present review, we discuss in detail the functions of genes and enzymes involved in the biosynthetic pathway of the dihydrochalcones and the recent strategies and achievements used in the reconstruction of multi-enzyme pathways in microorganisms in efforts to be able to attain higher amounts of desired dihydrochalcones.

Arabinogalactan proteins: focus on carbohydrate active enzymes

Directory of Open Access Journals (Sweden)

Eva eKnoch

2014-06-01

Full Text Available Arabinogalactan proteins (AGPs are a highly diverse class of cell surface proteoglycans that are commonly found in most plant species. AGPs play important roles in many cellular processes during plant development, such as reproduction, cell proliferation, pattern formation and growth, and in plant-microbe interaction. However, little is known about the molecular mechanisms of their function. Numerous studies using monoclonal antibodies that recognize different AGP glycan epitopes have shown the appearance of a slightly altered AGP glycan in a specific stage of development in plant cells. Therefore, it is anticipated that the biosynthesis and degradation of AGP glycan is tightly regulated during development. Until recently, however, little was known about the enzymes involved in the metabolism of AGP glycans. In this review, we summarize recent discoveries of carbohydrate active enzymes (CAZy; http://www.cazy.org/ involved in the biosynthesis and degradation of AGP glycans, and we discuss the biological role of these enzymes in plant development.

Development of enzymes and enzyme systems by genetic engineering to convert biomass to sugars

Science.gov (United States)

TITLE Development of Enzymes and Enzyme Systems by Genetic Engineering to Convert Biomass to Sugars ABSTRACT Plant cellulosic material is one of the most viable renewable resources for the world’s fuel and chemical feedstock needs. Currently ethanol derived from corn starch is the most common li...

FT Raman microscopy of untreated natural plant fibres

Science.gov (United States)

Edwards, H. G. M.; Farwell, D. W.; Webster, D.

1997-11-01

The application of FT-Raman microscopy to the non-destructive analysis of natural plant fibres is demonstrated with samples of flax, jute, ramie, cotton, kapok, sisal and coconut fibre. Vibrational assignments are proposed and characteristic features of each material are presented. Samples were not pre-treated chemically before analysis and were used directly from their respective storage collection; the adaptation of the Raman microscopic technique to the identification of specimens of natural fibres in archaeological burial sites is explored for its forensic potential.

Enzymes of industrial purpose - review of the market of enzyme preparations and prospects for its development

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A. A. Tolkacheva

2017-01-01

Full Text Available Microbial enzyme preparations are increasingly replacing conventional chemical catalysts in a number of industrial processes. Such drugs, in addition to environmental friendliness and high activity, have a number of advantages over enzyme preparations of vegetable and animal origin, namely: the production of microbial enzymes in bioreactors is easily controlled and predictable; excreted microbiological enzymes are more stable than intracellular animals and plant enzymes; the genetic diversity of microorganisms makes it possible to produce enzyme preparations with a wide range of specificity; microbiological enzymes can be synthesized year-round, in contrast to the production of plant enzymes, which is often seasonal. The leaders of the world market of enzymes are proteases and amylases, which account for 25% and 15%, respectively. Over the past five years, the world market for carbohydrases, including mainly amylases, cellulases and xylanases, has been the fastest growing segment of the enzyme market with an aggregate annual growth rate of more than 7.0%. Another major product of the industrial enzyme market, which has a great potential for growth, is lipases. From the point of view of designation, the main part is represented by food and food enzymes. The Russian market continues to be unsaturated - the current supply is not able to meet the needs of the Russian feed and food industry in enzyme preparations. Enzyme preparations of domestic producers are in demand in forage production, while food industrial enterprises prefer imported products. The most significant enterprises in the enzymatic industry in Russia at the moment are Sibbiofarm, AgroSistema, Agroferment. In the light of the Russian policy of increasing food security, the development of the domestic enzyme industry is an extremely topical task.

Using Plants to Explore the Nature & Structural Complexity of Life

Science.gov (United States)

Howard, Ava R.

2014-01-01

Use of real specimens brings the study of biology to life. This activity brings easily acquired plant specimens into the classroom to tackle common alternative conceptions regarding life, size, complexity, the nature of science, and plants as multicellular organisms. The activity occurs after a discussion of the characteristics of life and engages…

Assessing the Greenhouse Gas Emissions from Natural Gas Fired Power Plants

Science.gov (United States)

Hajny, K. D.; Shepson, P. B.; Rudek, J.; Stirm, B. H.; Kaeser, R.; Stuff, A. A.

2017-12-01

Natural gas is often discussed as a "bridge fuel" to transition to renewable energy as it only produces 51% the amount of CO2 per unit energy as coal. This, coupled with rapid increases in production fueled by technological advances, has led to a near tripling of natural gas used for electricity generation since 2005. One concern with this idea of a "bridge fuel" is that methane, the primary component of natural gas, is itself a potent greenhouse gas with 28 and 84 times the global warming potential of CO2 based on mass over a 100 and 20 year period, respectively. Studies have estimated that leaks from the point of extraction to end use of 3.2% would offset the climate benefits of natural gas. Previous work from our group saw that 3 combined cycle power plants emitted unburned CH4 from the stacks and leaked additional CH4 from equipment on site, but total loss rates were still less than 2.2%. Using Purdue's Airborne Laboratory for Atmospheric Research (ALAR) we completed additional aircraft based mass balance experiments combined with passes directly over power plant stacks to expand on the previous study. In this work, we have measured at 12 additional natural gas fired power plants including a mix of operation types (baseload, peaking, intermediate) and firing methods (combined cycle, simple thermal, combustion turbine). We have also returned to the 3 plants previously sampled to reinvestigate emissions for each of those, to assess reproducibility of the results. Here we report the comparison of reported continuous emissions monitoring systems (CEMS) data for CO2 to our emission rates calculated from mass balance experiments, as well as a comparison of calculated CH4 emission rates to estimated emission rates based on the EPA emission factor of 1 g CH4/mmbtu natural gas and CEMS reported heat input. We will also discuss emissions from a coal-fired plant which has been sampled by the group in the past and has since converted to natural gas. Lastly, we discuss the

Activating antioxidant enzymes, hyoscyamine and scopolamine biosynthesis of Hyoscyamus niger L. plants with nano-sized titanium dioxide and bulk application

Directory of Open Access Journals (Sweden)

Mansour GHORBANPOUR

2015-11-01

Full Text Available  Application of nanotechnology is now widely distributed overall the life, especially in agricultural systems. This study intended to indicate the impacts of nano-sized titanium dioxide particles (NT and bulk (BT on antioxidant enzymes activities including superoxide dismutase (SOD, peroxidase (POX and catalase (CAT, and variations of two major tropane alkaloids such as hyoscyamine (HYO and scopolamine (SCO in Hyoscyamus niger L. Plants were treated with different concentrations of NT and BT (0, 20, 40 and 80 mg l-1. Alkaloids extracted were identified by gas chromatography (GC and gas chromatography-mass spectrometry (GC-MS analysis. Results showed that SOD activity increased with increasing titanium dioxide concentration in both nano-particles and bulk treated plants. However, the highest and the lowest POX activity were observed in plants exposed to NT at 40 mg l-1 and control, respectively. Generally, all tested enzymes activities were higher in NT treated plants that those of BT except CAT activity at 80 mg l-1. The highest alkaloids content values, HYO: 0.286 g kg-1 and SCO: 0.126 g kg-1, were achieved in plants treated with NT at 80 and 20 mg l-1, respectively. The maximum and minimum plant biomass and subsequently total alkaloids yield were obtained in plants exposed to NT at 40 mg l-1 and controls, respectively. Our results suggest that NT in appropriate level (40 mg l-1 may act as an elicitor for biochemical responses and tropane alkaloids biosynthesis in H. niger plants. 

Synthesis of non-natural carbohydrates from glycerol and aldehydes in a one-pot four-enzyme cascade reaction

NARCIS (Netherlands)

Babich, L.; Hartog, L.; Falcicchio, P.; Oost, van der J.

2011-01-01

A simple procedure has been developed for the synthesis of enantio- and diastereomerically pure carbohydrate analogues from glycerol and a variety of aldehydes in one pot using a four-enzyme cascade reaction. As a proof of concept of the usefulness of this enzymatic catalytic cascade the naturally

Nuclear power plant decommissioning. The nature of problems

Energy Technology Data Exchange (ETDEWEB)

Yunus, Yaziz

1986-04-01

A number of issues have to be taken into account before the introduction of any nuclear power plant in any country. These issues include reactor safety (site and operational), waste disposal and, lastly, the decommissioning of the reactor inself. Because of the radioactive nature of the components, nuclear power plants require a different approach to decommission compared to other plants. Until recently, issues on reactor safety and waste disposal were the main topics discussed. As for reactor decommissioning, the debates have been academic until now. Although reactors have operated for 25 years, decommissioning of retired reactors has simply not been fully planned. But the Shippingport Atomic Power Plant in Pennysylvania, the first large-scale power reactor to be retired, is now being decommissioned. The work has rekindled the debate in the light of reality. Outside the United States, decommissioning is also being confronted on a new plane.

Priming of plant resistance by natural compounds. Hexanoic acid as a model

Directory of Open Access Journals (Sweden)

Paz eAranega Bou

2014-10-01

Full Text Available Some alternative control strategies of currently emerging plant diseases are based on the use of resistance inducers. This review highlights the recent advances made in the characterization of natural compounds that induce resistance by a priming mechanism. These include vitamins, chitosans, oligogalacturonides, volatile organic compounds, azelaic and pipecolic acid, among others. Overall, other than providing novel disease control strategies that meet environmental regulations, natural priming agents are valuable tools to help unravel the complex mechanisms underlying the induced resistance phenomenon. The data presented in this review reflect the novel contributions made from studying these natural plant inducers, with special emphasis placed on hexanoic acid (Hx, proposed herein as a model tool for this research field. Hx is a potent natural priming agent of proven efficiency in a wide range of host plants and pathogens. It can early activate broad-spectrum defenses by inducing callose deposition and the SA and JA pathways. Later it can prime pathogen-specific responses according to the pathogen’s lifestyle. Interestingly, Hx primes redox-related genes to produce an anti-oxidant protective effect, which might be critical for limiting the infection of necrotrophs. Our Hx-induced resistance (Hx-IR findings also strongly suggest that it is an attractive tool for the molecular characterization of the plant alarmed state, with the added advantage of it being a natural compound.

Improving a natural enzyme activity through incorporation of unnatural amino acids.

Science.gov (United States)

Ugwumba, Isaac N; Ozawa, Kiyoshi; Xu, Zhi-Qiang; Ely, Fernanda; Foo, Jee-Loon; Herlt, Anthony J; Coppin, Chris; Brown, Sue; Taylor, Matthew C; Ollis, David L; Mander, Lewis N; Schenk, Gerhard; Dixon, Nicholas E; Otting, Gottfried; Oakeshott, John G; Jackson, Colin J

2011-01-19

The bacterial phosphotriesterases catalyze hydrolysis of the pesticide paraoxon with very fast turnover rates and are thought to be near to their evolutionary limit for this activity. To test whether the naturally evolved turnover rate could be improved through the incorporation of unnatural amino acids and to probe the role of peripheral active site residues in nonchemical steps of the catalytic cycle (substrate binding and product release), we replaced the naturally occurring tyrosine amino acid at position 309 with unnatural L-(7-hydroxycoumarin-4-yl)ethylglycine (Hco) and L-(7-methylcoumarin-4-yl)ethylglycine amino acids, as well as leucine, phenylalanine, and tryptophan. Kinetic analysis suggests that the 7-hydroxyl group of Hco, particularly in its deprotonated state, contributes to an increase in the rate-limiting product release step of substrate turnover as a result of its electrostatic repulsion of the negatively charged 4-nitrophenolate product of paraoxon hydrolysis. The 8-11-fold improvement of this already highly efficient catalyst through a single rationally designed mutation using an unnatural amino acid stands in contrast to the difficulty in improving this native activity through screening hundreds of thousands of mutants with natural amino acids. These results demonstrate that designer amino acids provide easy access to new and valuable sequence and functional space for the engineering and evolution of existing enzyme functions.

Plant natural products research in tuberculosis drug discovery and ...

African Journals Online (AJOL)

Plant natural products research in tuberculosis drug discovery and development: A situation report ... African Journal of Biotechnology ... tuberculosis (XDR-TB), call for the development of new anti-tuberculosis drugs to combat this disease.

Managing invasive plants in natural areas: Moving beyond weed control

Science.gov (United States)

Dean Pearson; Yvette Ortega

2009-01-01

Exotic invasive plants present one of the greatest challenges to natural resource management. These weeds can alter entire communities and ecosystems, substantially degrading important ecosystem services such as forage for wild and domestic herbivores, water and soil quality, recreational values, and wildlife habitat. Traditionally, weed management in natural areas has...

Application of ionic liquids based enzyme-assisted extraction of chlorogenic acid from Eucommia ulmoides leaves

Energy Technology Data Exchange (ETDEWEB)

Liu, Tingting; Sui, Xiaoyu, E-mail: suixiaoyu@outlook.com; Li, Li; Zhang, Jie; Liang, Xin; Li, Wenjing; Zhang, Honglian; Fu, Shuang

2016-01-15

A new approach for ionic liquid based enzyme-assisted extraction (ILEAE) of chlorogenic acid (CGA) from Eucommia ulmoides is presented in which enzyme pretreatment was used in ionic liquids aqueous media to enhance extraction yield. For this purpose, the solubility of CGA and the activity of cellulase were investigated in eight 1-alkyl-3-methylimidazolium ionic liquids. Cellulase in 0.5 M [C6mim]Br aqueous solution was found to provide better performance in extraction. The factors of ILEAE procedures including extraction time, extraction phase pH, extraction temperatures and enzyme concentrations were investigated. Moreover, the novel developed approach offered advantages in term of yield and efficiency compared with other conventional extraction techniques. Scanning electronic microscopy of plant samples indicated that cellulase treated cell wall in ionic liquid solution was subjected to extract, which led to more efficient extraction by reducing mass transfer barrier. The proposed ILEAE method would develope a continuous process for enzyme-assisted extraction including enzyme incubation and solvent extraction process. In this research, we propose a novel view for enzyme-assisted extraction of plant active component, besides concentrating on enzyme facilitated cell wall degradation, focusing on improvement of bad permeability of ionic liquids solutions. - Highlights: • An ionic liquid based enzyme-assisted extraction method of natural product was explored. • ILEAE utilizes enzymatic treatment to improve permeability of ionic liquids solution. • Enzyme incubation and solvent extraction process were ongoing simultaneously. • ILEAE process simplified operating process and suitable for more complete extraction.

Application of ionic liquids based enzyme-assisted extraction of chlorogenic acid from Eucommia ulmoides leaves

International Nuclear Information System (INIS)

Liu, Tingting; Sui, Xiaoyu; Li, Li; Zhang, Jie; Liang, Xin; Li, Wenjing; Zhang, Honglian; Fu, Shuang

2016-01-01

A new approach for ionic liquid based enzyme-assisted extraction (ILEAE) of chlorogenic acid (CGA) from Eucommia ulmoides is presented in which enzyme pretreatment was used in ionic liquids aqueous media to enhance extraction yield. For this purpose, the solubility of CGA and the activity of cellulase were investigated in eight 1-alkyl-3-methylimidazolium ionic liquids. Cellulase in 0.5 M [C6mim]Br aqueous solution was found to provide better performance in extraction. The factors of ILEAE procedures including extraction time, extraction phase pH, extraction temperatures and enzyme concentrations were investigated. Moreover, the novel developed approach offered advantages in term of yield and efficiency compared with other conventional extraction techniques. Scanning electronic microscopy of plant samples indicated that cellulase treated cell wall in ionic liquid solution was subjected to extract, which led to more efficient extraction by reducing mass transfer barrier. The proposed ILEAE method would develope a continuous process for enzyme-assisted extraction including enzyme incubation and solvent extraction process. In this research, we propose a novel view for enzyme-assisted extraction of plant active component, besides concentrating on enzyme facilitated cell wall degradation, focusing on improvement of bad permeability of ionic liquids solutions. - Highlights: • An ionic liquid based enzyme-assisted extraction method of natural product was explored. • ILEAE utilizes enzymatic treatment to improve permeability of ionic liquids solution. • Enzyme incubation and solvent extraction process were ongoing simultaneously. • ILEAE process simplified operating process and suitable for more complete extraction.

Use of anthocyanin extracted from natural plant materials to develop ...

African Journals Online (AJOL)

The aim of this work was to study the optimal conditions for anthocyanin extraction from natural plant materials in order to develop a pH test kit. The plant materials used were butterfly pea flower (BPF), roselle red flower (RRF) and dragon fruit peel (DFP). The solvents used in this study were distilled water, 1% HCl/95% ...

Enzymes and fungal virulence | Tonukari | Journal of Applied ...

African Journals Online (AJOL)

This paper presents a comprehensive literature review of cell wall degrading enzymes (CWDEs). Plant pathogenic fungi secrete extracellular enzymes that are capable of degrading the cell walls of their host plants. These CWDEs may be necessary for penetration of the cell wall barrier, as well as for generation of simple ...

Induction of antioxidant enzyme activity and lipid peroxidation level in ion-beam-bombarded rice seeds

Science.gov (United States)

Semsang, Nuananong; Yu, LiangDeng

2013-07-01

Low-energy ion beam bombardment has been used to mutate a wide variety of plant species. To explore the indirect effects of low-energy ion beam on biological damage due to the free radical production in plant cells, the increase in antioxidant enzyme activities and lipid peroxidation level was investigated in ion-bombarded rice seeds. Local rice seeds were bombarded with nitrogen or argon ion beams at energies of 29-60 keV and ion fluences of 1 × 1016 ions cm-2. The activities of the antioxidant enzymes; superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR), glutathione reductase (GR), glutathione S-transferase (GST) and lipid peroxidation level were assayed in the germinated rice seeds after ion bombardment. The results showed most of the enzyme activities and lipid peroxidation levels in both the argon and nitrogen bombarded samples were higher than those in the natural control. N-ion bombardment could induce higher levels of antioxidant enzyme activities in the rice samples than the Ar-ion bombardment. Additional effects due to the vacuum condition were found to affect activities of some antioxidant enzymes and lipid peroxidation level. This study demonstrates that ion beam bombardment and vacuum condition could induce the antioxidant enzyme activity and lipid peroxidation level which might be due to free radical production in the bombarded rice seeds.

Natural radioactivity around the coal-fired power plant

International Nuclear Information System (INIS)

Kovac, J.; Bajlo, M.

1996-01-01

By far the greatest part of the radiation received by the worlds population comes from natural sources, in some situations the exposure to natural radiation sources is enhanced as a result of technological developments. Burning of coal is one source of enhanced radiation exposure to naturally occurring elements, particularly radium, thorium and uranium. Extensive investigations have been performed in the coal-fired power plant (CFPP) Plomin in Croatia, using an anthracite coal with a higher than usual uranium content and normal thorium content. A network of TL dosimeters (TLD), working levels (WL) measurements, air pollution monitoring and monitoring of waste pile were organized. Some of the measurements have been repeated, and the results have shown decreased contamination. (author)

Plant Size as Determinant of Species Richness of Herbivores, Natural Enemies and Pollinators across 21 Brassicaceae Species.

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Hella Schlinkert

Full Text Available Large plants are often more conspicuous and more attractive for associated animals than small plants, e.g. due to their wider range of resources. Therefore, plant size can positively affect species richness of associated animals, as shown for single groups of herbivores, but studies usually consider intraspecific size differences of plants in unstandardised environments. As comprehensive tests of interspecific plant size differences under standardised conditions are missing so far, we investigated effects of plant size on species richness of all associated arthropods using a common garden experiment with 21 Brassicaceae species covering a broad interspecific plant size gradient from 10 to 130 cm height. We recorded plant associated ecto- and endophagous herbivores, their natural enemies and pollinators on and in each aboveground plant organ, i.e. flowers, fruits, leaves and stems. Plant size (measured as height from the ground, the number of different plant organ entities and their biomass were assessed. Increasing plant size led to increased species richness of associated herbivores, natural enemies and pollinating insects. This pattern was found for ectophagous and endophagous herbivores, their natural enemies, as well as for herbivores associated with leaves and fruits and their natural enemies, independently of the additional positive effects of resource availability (i.e. organ biomass or number of entities and, regarding natural enemies, herbivore species richness. We found a lower R2 for pollinators compared to herbivores and natural enemies, probably caused by the high importance of flower characteristics for pollinator species richness besides plant size. Overall, the increase in plant height from 10 to 130 cm led to a 2.7-fold increase in predicted total arthropod species richness. In conclusion, plant size is a comprehensive driver of species richness of the plant associated arthropods, including pollinators, herbivores and their

Comparison of bacterial and fungal communities between natural and planted pine forests in subtropical China.

Science.gov (United States)

Nie, Ming; Meng, Han; Li, Ke; Wan, Jia-Rong; Quan, Zhe-Xue; Fang, Chang-Ming; Chen, Jia-Kuan; Li, Bo

2012-01-01

To improve our understanding of the changes in bacterial and fungal diversity in natural pine and planted forests in subtropical region of China, we examined bacterial and fungal communities from a native and a nearby planted pine forest of the Mt. Lushan by constructing clone libraries of 16S and 18S rRNA genes. For bacterial communities, Proteobacteria and Acidobacteria were dominant bacterial taxa in both two types of forest soils. The Shannon-Wiener diversity index, rarefaction curve analysis, and LibShuff analysis suggest that these two forests contained similar diversity of bacterial communities. Low soil acidity (pH ≈ 4) of our study forests might be one of the most important selection factors determining growth of acidophilic Acidobacteria and Proteobacteria. However, the natural forest harbored greater level of fungal diversity than the planted forest according to the Shannon-Wiener diversity index and rarefaction curve analysis. Basidiomycota and Ascomycota were dominant fungal taxa in the soils of natural and planted forests, respectively. Our results suggest that fungal community was more sensitive than the bacterial community in characterizing the differences in plant cover impacts on the microbial flora in the natural and planted forests. The natural and planted forests may function differently due to the differences in soil fungal diversity and relative abundance.

de novo computational enzyme design.

Science.gov (United States)

Zanghellini, Alexandre

2014-10-01

Recent advances in systems and synthetic biology as well as metabolic engineering are poised to transform industrial biotechnology by allowing us to design cell factories for the sustainable production of valuable fuels and chemicals. To deliver on their promises, such cell factories, as much as their brick-and-mortar counterparts, will require appropriate catalysts, especially for classes of reactions that are not known to be catalyzed by enzymes in natural organisms. A recently developed methodology, de novo computational enzyme design can be used to create enzymes catalyzing novel reactions. Here we review the different classes of chemical reactions for which active protein catalysts have been designed as well as the results of detailed biochemical and structural characterization studies. We also discuss how combining de novo computational enzyme design with more traditional protein engineering techniques can alleviate the shortcomings of state-of-the-art computational design techniques and create novel enzymes with catalytic proficiencies on par with natural enzymes. Copyright © 2014 Elsevier Ltd. All rights reserved.

Production of Enzymes from Marine Actinobacteria.

Science.gov (United States)

Zhao, X Q; Xu, X N; Chen, L Y

Marine actinobacteria are well recognized for their capabilities to produce valuable natural products, which have great potential for applications in medical, agricultural, and fine chemical industries. In addition to producing unique enzymes responsible for biosynthesis of natural products, many marine actinobacteria also produce hydrolytic enzymes which are able to degrade various biopolymers, such as cellulose, xylan, and chitin. These enzymes are important to produce biofuels and biochemicals of interest from renewable biomass. In this chapter, the recent reports of novel enzymes produced by marine actinobacteria are reviewed, and advanced technologies that can be applied to search for novel marine enzymes as well as for improved enzyme production by marine actinobacteria are summarized, which include ribosome engineering, genome mining, as well as synthetic biology studies. © 2016 Elsevier Inc. All rights reserved.

Covalent attachment of the plant natural product naringenin to small glass and ceramic beads

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Grotewold Erich

2005-10-01

Full Text Available Abstract Background Natural products have numerous medicinal applications and play important roles in the biology of the organisms that accumulate them. Few methods are currently available for identifying proteins that bind to small molecules, therefore the discovery of cellular targets for natural products with pharmacological activity continues to pose a significant challenge in drug validation. Similarly, the identification of enzymes that participate in the biosynthesis or modification of natural products remains a formidable bottleneck for metabolic engineering. Flavonoids are one large group of natural products with a diverse number of functions in plants and in human health. The coupling of flavonoids to small ceramic and glass beads provides a first step in the development of high-throughput, solid-support base approaches to screen complex libraries to identify proteins that bind natural products. Results The utilization of small glass and ceramic beads as solid supports for the coupling of small molecules was explored. Initial characterization of the beads indicated uniform and high capacity loading of amino groups. Once the beads were deemed adequate for the linking of small molecules by the coupling of NHS-fluorescein followed by microscopy, chemical hydrolysis and fluorometry, the flavonoid naringenin was modified with 1,4-dibromobutane, followed by the attachment of aminopropyltriethoxysilane. After NMR structural confirmation, the resulting 7-(4-(3-(triethoxysilylpropylaminobutoxy naringenin was attached to the ceramic beads. Conclusion Our results demonstrate that ceramic and glass beads provide convenient solid supports for the efficient and facile coupling of small molecules. We succeeded in generating naringenin-coupled ceramic and glass beads. We also developed a convenient series of steps that can be applied for the solid-support coupling of other related flavonoids. The availability of solid-support coupled naringenin opens

Incorporation of natural radionuclides and rare earth element into a salt tolerant plant

International Nuclear Information System (INIS)

Summerton, A.P.

1992-01-01

A highly salt tolerant shrub, samphire (Halosarcia halocnemoides), found growing in the solid alkaline residues in an evaporation pond at a former uranium and monazite treatment plant, has been analysed for natural radionuclides and rare earths. The data obtained have been copared with that for plants from the local natural environment. Vegetation-to-soil concentration ratios have been determined. The radionuclide concentration ratios for samples from the contaminated site are similar to those from the natural environment. Significant differences have been noted in the case of the rare earth elements with an apparent preferential incorporation of the light rare earth elements into the plant growing in the chemical residues. (author) 10 refs.; 1 fig.; 2 tabs

Plant volatile aldehydes as natural insecticides against stored-product beetles.

Science.gov (United States)

Hubert, Jan; Münzbergová, Zuzana; Santino, Angelo

2008-01-01

Infestation by stored-product pests causes serious losses in food and feed commodities. Among possible strategies against these pests, which aim to reduce the use of synthetic insecticides, including fumigants, natural insecticides produced by plants represent one of the most promising approaches for their ecochemical control. Three six-carbon and nine-carbon aldehydes, natural plant volatiles produced by the plant lipoxygenase pathway, were tested for their insecticidal activity against five species of stored-product beetles in feeding, fumigation and combined bioassays. The compounds (2E,6Z)-nonadienal, (2E)-nonenal and (2E)-hexenal were incorporated into feeding discs in feeding bioassays or evaporated from filter paper in closed glass chambers in fumigation tests. Beetle sensitivity to aldehydes differed according to the different treatments. The highest activity was obtained by (2E)-hexenal in fumigation tests, with the LC(50) ranging from 4 to 26 mg L(-1), while (2E, 6Z)-nonadienal was the most effective in feeding tests, giving LD(50)s ranging from 0.44 to 2.76 mg g(-1) when applied to feeding discs. Fumigation tests in the presence of wheat grains confirmed that (2E)-hexenal was the most effective compound, with a calculated LC(99) ranging from 33 to 166 mg L(-1). The results of both feeding and fumigation tests indicated that natural plant aldehydes are potential candidates to control stored-product beetles.

Subcellular site and nature of intracellular cadmium in plants

International Nuclear Information System (INIS)

Wagner, G.J.

1979-01-01

The mechanisms underlying heavy metal accumulation, toxicity, and tolerance in higher plants are poorly understood. Since subcellular processes are undoubtedly involved in all these phenomena, it is of interest to study the extent, subcellular site and nature of intracellularly accumulated cadmium in higher plants. Whole plants supplied 109 CdCl 2 or 112 CdSO 4 accumulated Cd into roots and aerial tissues. Preparation of protoplasts from aerial tissues followed by subcellular fractionation of the protoplasts to obtain intact vacuoles, chloroplasts and cytosol revealed the presence of Cd in the cytosol but not in vacuoles or chloroplasts. No evidence was obtained for the production of volatile Cd complexes in tobacco

A short history of RubisCO: the rise and fall (?) of Nature's predominant CO2 fixing enzyme.

Science.gov (United States)

Erb, Tobias J; Zarzycki, Jan

2018-02-01

Ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO) is arguably one of the most abundant proteins in the biosphere and a key enzyme in the global carbon cycle. Although RubisCO has been intensively studied, its evolutionary origins and rise as Nature's most dominant carbon dioxide (CO 2 )-fixing enzyme still remain in the dark. In this review we will bring together biochemical, structural, physiological, microbiological, as well as phylogenetic data to speculate on the evolutionary roots of the CO 2 -fixation reaction of RubisCO, the emergence of RubisCO-based autotrophic CO 2 -fixation in the context of the Calvin-Benson-Bassham cycle, and the further evolution of RubisCO into the 'RubisCOsome', a complex of various proteins assembling and interacting with the enzyme to improve its operational capacity (functionality) under different biological and environmental conditions. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Nanoarmored Enzymes for Organic Enzymology: Synthesis and Characterization of Poly(2-Alkyloxazoline)-Enzyme Conjugates.

Science.gov (United States)

Leurs, Melanie; Tiller, Joerg C

2017-01-01

The properties of enzymes can be altered significantly by modification with polymers. Numerous different methods are known to obtain such polymer-enzyme conjugates (PECs). However, there is no universal method to render enzymes into PECs that are fully soluble in organic solvents. Here, we present a method, which achieves such high degree of modification of proteins that the majority of modified enzymes will be soluble in organic solvents. This is achieved by preparing poly(2-alkyloxazoline)s (POx) with an NH 2 end group and coupling this functional polymer via pyromellitic acid dianhydride onto the amino groups of the respective protein. The resulting PECs are capable of serving as surfactants for unmodified proteins, rendering the whole mixture organosoluble. Depending on the nature of the POx and the molecular weight and the nature of the enzyme, the PECs are soluble in chloroform or even toluene. Another advantage of this method is that the poly(2-alkyloxazoline) can be activated with the coupling agent and used for the enzyme conjugation without further purification. The POx-enzyme conjugates generated by this modification strategy show modulated catalytic activity in both, aqueous and organic, systems. © 2017 Elsevier Inc. All rights reserved.

Enzyme Mimics: Advances and Applications.

Science.gov (United States)

Kuah, Evelyn; Toh, Seraphina; Yee, Jessica; Ma, Qian; Gao, Zhiqiang

2016-06-13

Enzyme mimics or artificial enzymes are a class of catalysts that have been actively pursued for decades and have heralded much interest as potentially viable alternatives to natural enzymes. Aside from having catalytic activities similar to their natural counterparts, enzyme mimics have the desired advantages of tunable structures and catalytic efficiencies, excellent tolerance to experimental conditions, lower cost, and purely synthetic routes to their preparation. Although still in the midst of development, impressive advances have already been made. Enzyme mimics have shown immense potential in the catalysis of a wide range of chemical and biological reactions, the development of chemical and biological sensing and anti-biofouling systems, and the production of pharmaceuticals and clean fuels. This Review concerns the development of various types of enzyme mimics, namely polymeric and dendrimeric, supramolecular, nanoparticulate and proteinic enzyme mimics, with an emphasis on their synthesis, catalytic properties and technical applications. It provides an introduction to enzyme mimics and a comprehensive summary of the advances and current standings of their applications, and seeks to inspire researchers to perfect the design and synthesis of enzyme mimics and to tailor their functionality for a much wider range of applications. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Gene Duplication Leads to Altered Membrane Topology of a Cytochrome P450 Enzyme in Seed Plants.

Science.gov (United States)

Renault, Hugues; De Marothy, Minttu; Jonasson, Gabriella; Lara, Patricia; Nelson, David R; Nilsson, IngMarie; André, François; von Heijne, Gunnar; Werck-Reichhart, Danièle

2017-08-01

Evolution of the phenolic metabolism was critical for the transition of plants from water to land. A cytochrome P450, CYP73, with cinnamate 4-hydroxylase (C4H) activity, catalyzes the first plant-specific and rate-limiting step in this pathway. The CYP73 gene is absent from green algae, and first detected in bryophytes. A CYP73 duplication occurred in the ancestor of seed plants and was retained in Taxaceae and most angiosperms. In spite of a clear divergence in primary sequence, both paralogs can fulfill comparable cinnamate hydroxylase roles both in vitro and in vivo. One of them seems dedicated to the biosynthesis of lignin precursors. Its N-terminus forms a single membrane spanning helix and its properties and length are highly constrained. The second is characterized by an elongated and variable N-terminus, reminiscent of ancestral CYP73s. Using as proxies the Brachypodium distachyon proteins, we show that the elongation of the N-terminus does not result in an altered subcellular localization, but in a distinct membrane topology. Insertion in the membrane of endoplasmic reticulum via a double-spanning open hairpin structure allows reorientation to the lumen of the catalytic domain of the protein. In agreement with participation to a different functional unit and supramolecular organization, the protein displays modified heme proximal surface. These data suggest the evolution of divergent C4H enzymes feeding different branches of the phenolic network in seed plants. It shows that specialization required for retention of gene duplicates may result from altered protein topology rather than change in enzyme activity. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Multiple RNA processing defects and impaired chloroplast function in plants deficient in the organellar protein-only RNase P enzyme.

Directory of Open Access Journals (Sweden)

Wenbin Zhou

Full Text Available Transfer RNA (tRNA precursors undergo endoribonucleolytic processing of their 5' and 3' ends. 5' cleavage of the precursor transcript is performed by ribonuclease P (RNase P. While in most organisms RNase P is a ribonucleoprotein that harbors a catalytically active RNA component, human mitochondria and the chloroplasts (plastids and mitochondria of seed plants possess protein-only RNase P enzymes (PRORPs. The plant organellar PRORP (PRORP1 has been characterized to some extent in vitro and by transient gene silencing, but the molecular, phenotypic and physiological consequences of its down-regulation in stable transgenic plants have not been assessed. Here we have addressed the function of the dually targeted organellar PRORP enzyme in vivo by generating stably transformed Arabidopsis plants in which expression of the PRORP1 gene was suppressed by RNA interference (RNAi. PRORP1 knock-down lines show defects in photosynthesis, while mitochondrial respiration is not appreciably affected. In both plastids and mitochondria, the effects of PRORP1 knock-down on the processing of individual tRNA species are highly variable. The drastic reduction in the levels of mature plastid tRNA-Phe(GAA and tRNA-Arg(ACG suggests that these two tRNA species limit plastid gene expression in the PRORP1 mutants and, hence, are causally responsible for the mutant phenotype.

Influence of a Modified Plant Extract on Activity of Antioxidant Enzymes and Concentration of Pigments in Gamma-Irradiated Plants of Maize and Wheat

Directory of Open Access Journals (Sweden)

Azizov Ibrahim

2018-02-01

Full Text Available The influence of a medicinal plant extract, immobilised by ligands, on the activity of antioxidant enzymes and photosynthetic pigment concentration of wheat and maize was studied. The object of study was seed of drought-resistant firm durum wheat (Triticum durum Desf. and maize (Zea mays L.. Seeds were subjected to general uniform γ-radiation from a 60Co source on a Rkhund installation at average dose power of MD = 0.306 Gy/sec. Before radiation seeds were treated in modified extract from medicinal plants. The treatment of seeds with 0.1 and 0.01% solution of modified extract from Hypericum, Dandelion, and Calendula caused significant reduction in processes initiated by radiation and in formation of free radicals. On the basis of the obtained results it was concluded that the used modified plant extract collection had a protective effect, reducing the amount of free radicals produced by γ-irradiation.

Occurrence of 222Rn and progeny in natural gas processing plants in western Canada

International Nuclear Information System (INIS)

Drummond, I.; Boucher, P.; Bradford, B.; Evans, H.; McLean, J.; Reczek, E.; Thunem, H.

1990-01-01

In Western Canada, there are many plants that process natural gas to remove impurities (CO 2 , H 2 S, H 2 O) and recover natural gas liquids (propane, butane, etc.). Trace quantities of 222 Rn present in the inlet stream are concentrated in streams rich with propane. Potential hazards to plant operators include direct inhalation of 222 Rn and progeny; exposure to gamma radiation from short-lived progeny deposited inside equipment; or inhalation of 210 Pb when contaminated equipment is opened for repair. Twenty-four plants operated by seven companies cooperated to assess these potential hazards. The findings indicate a substantial flux of 222 Rn and progeny passing through the plants, but little accumulation of radionuclides. In no case was there evidence of significant exposure of plant operators or maintenance personnel to ionizing radiation. Further investigation of pipeline operations, and chemical operations using natural gas liquids as feed stock, is recommended

The study of distribution characteristics of vascular and naturalized plants in Dokdo, South Korea

Directory of Open Access Journals (Sweden)

Su-Young Jung

2014-06-01

Full Text Available This study was performed to investigate the distribution of vascular plants and the characteristics of naturalized plants in Dokdo Island, South Korea. The survey was conducted a total of 5 times from June 2012 to September 2013. The number of plants confirmed in this study was 60 taxa in total: 29 families, 49 genera, 55 species, 2 subspecies and 3 varieties. To classify them by regional groups, 53 taxa were confirmed in the Dongdo and 38 taxa were confirmed in the Seodo. Among them, the distribution of Stellaria neglecta Weihe and Puccinellia nipponica Ohwi was first discovered in this study. The naturalized plants distributed in Dokdo was 7 taxa: Chenopodium album L., Sonchus asper (L. Hill, Sonchus oleraceus L., Ipomoea purpurea Roth, Brassica juncea (L. Czern., etc. Overall, concerns over the naturalized plants in Dokdo are high regardless of the scale of their distribution and the appearance frequency.

Genetic polymorphisms of the CYP1A1, GSTM1, and GSTT1 enzymes and their influence on cardiovascular risk and lipid profile in people who live near a natural gas plant.

Science.gov (United States)

Pašalić, Daria; Marinković, Natalija

2017-03-01

The aim of this cross-sectional study was to see whether genetic polymorphisms of the enzymes CYP1A1, GSTM1, and GSTT1 are associated with higher risk of coronary artery disease (CAD) and whether they affect lipid profile in 252 subjects living near a natural gas plant, who are likely to be exposed to polycyclic aromatic hydrocarbons (PAHs). Fasting serum concentrations of biochemical parameters were determined with standard methods. Genetic polymorphisms of CYP 1A1 rs4646903, rs1048943, rs4986883, and rs1799814 were genotyped with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFPL), while GSTM1 and GSTT1 deletions were detected with multiplex PCR. Cardiovascular risk was assessed with Framingham risk score, and the subjects divided in two groups: >10% risk and ≤10% risk. The two groups did not differ in the genotype frequencies. MANCOVA analysis, which included lipid parameters, glucose, and BMI with sex, age, hypertension and smoking status as covariates, showed a significant difference between the GSTT1*0 and GSTT1*1 allele carriers (p=0.001). UNIANCOVA with same covariates showed that total cholesterol and triglyceride levels were significantly higher in GSTT1*1 allele carriers than in GSTT1*0 carriers (prisk of CAD, but that GSTT1 affects lipid profile.

The mechanisms of Excited states in enzymes

DEFF Research Database (Denmark)

Petersen, Frederic Nicolas Rønne; Bohr, Henrik

2010-01-01

Enzyme catalysis is studied on the basis of excited state processes, which are of electronic, vibrational and thermal nature. The ways of achieving the excited state, such as photo-absorption and ligand binding, are discussed and exemplified by various cases of enzymes.......Enzyme catalysis is studied on the basis of excited state processes, which are of electronic, vibrational and thermal nature. The ways of achieving the excited state, such as photo-absorption and ligand binding, are discussed and exemplified by various cases of enzymes....

Enzymes with activity toward Xyloglucan

NARCIS (Netherlands)

Vincken, J.P.

2003-01-01

Xyloglucans are plant cell wall polysaccharides, which belong to the hemicellulose class. Here the structural variations of xyloglucans will be reviewed. Subsequently, the anchoring of xyloglucan in the plant cell wall will be discussed. Enzymes involved in degradation or modification of xyloglucan

Exergic, economic and environmental impacts of natural gas and diesel in operation of combined cycle power plants

International Nuclear Information System (INIS)

Mohammadi Khoshkar Vandani, Amin; Joda, Fatemeh; Bozorgmehry Boozarjomehry, Ramin

2016-01-01

Highlights: • Investigating the effect of natural gas and diesel on the power plant performance. • Exergy, economic and environmental evaluation of a combined cycle power plant. • Using life cycle assessment (LCA) to perform the environmental evaluation. • Optimizing the power plant in terms of exergy and economic. • Better performance of natural gas with respect to diesel. - Abstract: Combined cycle power plants (CCPPs) play an important role in electricity production throughout the world. Their energy efficiency is relatively high and their production rates of greenhouse gases are considerably low. In a country like Iran with huge oil and gas resources, most CCPP’s use natural gas as primary fuel and diesel as secondary fuel. In this study, effect of using diesel instead of natural gas for a selected power plant will be investigated in terms of exergy, economic and environmental impacts. The environmental evaluation is performed using life cycle assessment (LCA). In the second step, the operation of the plant will be optimized using exergy and economic objective functions. The results show that the exergy efficiency of the plant with natural gas as fuel is equal to 43.11%, while this efficiency with diesel will be 42.03%. Furthermore, the annual cost of plant using diesel is twice as that of plant using natural gas. Finally, diesel utilization leads to more contaminants production. Thus, environmental effects of diesel are much higher than that of natural gas. The optimization results demonstrate that in case of natural gas, exergy efficiency and annual cost of the power plant improve 2.34% and 4.99%, respectively. While these improvements for diesel are 2.36% and 1.97%.

Quality-related enzymes in plant-based products: effects of novel food processing technologies part 2: pulsed electric field processing.

Science.gov (United States)

Terefe, Netsanet Shiferaw; Buckow, Roman; Versteeg, Cornelis

2015-01-01

Pulsed electric field (PEF) processing is an effective technique for the preservation of pumpable food products as it inactivates vegetative microbial cells at ambient to moderate temperature without significantly affecting the nutritional and sensorial quality of the product. However, conflicting views are expressed about the effect of PEF on enzymes. In this review, which is part 2 of a series of reviews dealing with the effectiveness of novel food preservation technologies for controlling enzymes, the scientific literature over the last decade on the effect of PEF on plant enzymes is critically reviewed to shed more light on the issue. The existing evidence indicates that PEF can result in substantial inactivation of most enzymes, although a much more intense process is required compared to microbial inactivation. Depending on the processing condition and the origin of the enzyme, up to 97% inactivation of pectin methylesterase, polyphenol oxidase, and peroxidase as well as no inactivation have been reported following PEF treatment. Both electrochemical effects and Ohmic heating appear to contribute to the observed inactivation, although the relative contribution depends on a number of factors including the origin of the enzyme, the design of the PEF treatment chamber, the processing condition, and the composition of the medium.

Catalase and ascorbate peroxidase-representative H2O2-detoxifying heme enzymes in plants.

Science.gov (United States)

Anjum, Naser A; Sharma, Pallavi; Gill, Sarvajeet S; Hasanuzzaman, Mirza; Khan, Ekhlaque A; Kachhap, Kiran; Mohamed, Amal A; Thangavel, Palaniswamy; Devi, Gurumayum Devmanjuri; Vasudhevan, Palanisamy; Sofo, Adriano; Khan, Nafees A; Misra, Amarendra Narayan; Lukatkin, Alexander S; Singh, Harminder Pal; Pereira, Eduarda; Tuteja, Narendra

2016-10-01

Plants have to counteract unavoidable stress-caused anomalies such as oxidative stress to sustain their lives and serve heterotrophic organisms including humans. Among major enzymatic antioxidants, catalase (CAT; EC 1.11.1.6) and ascorbate peroxidase (APX; EC 1.11.1.11) are representative heme enzymes meant for metabolizing stress-provoked reactive oxygen species (ROS; such as H2O2) and controlling their potential impacts on cellular metabolism and functions. CAT mainly occurs in peroxisomes and catalyzes the dismutation reaction without requiring any reductant; whereas, APX has a higher affinity for H2O2 and utilizes ascorbate (AsA) as specific electron donor for the reduction of H2O2 into H2O in organelles including chloroplasts, cytosol, mitochondria, and peroxisomes. Literature is extensive on the glutathione-associated H2O2-metabolizing systems in plants. However, discussion is meager or scattered in the literature available on the biochemical and genomic characterization as well as techniques for the assays of CAT and APX and their modulation in plants under abiotic stresses. This paper aims (a) to introduce oxidative stress-causative factors and highlights their relationship with abiotic stresses in plants; (b) to overview structure, occurrence, and significance of CAT and APX in plants; (c) to summarize the principles of current technologies used to assay CAT and APX in plants; (d) to appraise available literature on the modulation of CAT and APX in plants under major abiotic stresses; and finally, (e) to consider a brief cross-talk on the CAT and APX, and this also highlights the aspects unexplored so far.

Improvement in Saccharification Yield of Mixed Rumen Enzymes by Identification of Recalcitrant Cell Wall Constituents Using Enzyme Fingerprinting.

Science.gov (United States)

Badhan, Ajay; Wang, Yu-Xi; Gruninger, Robert; Patton, Donald; Powlowski, Justin; Tsang, Adrian; McAllister, Tim A

2015-01-01

Identification of recalcitrant factors that limit digestion of forages and the development of enzymatic approaches that improve hydrolysis could play a key role in improving the efficiency of meat and milk production in ruminants. Enzyme fingerprinting of barley silage fed to heifers and total tract indigestible fibre residue (TIFR) collected from feces was used to identify cell wall components resistant to total tract digestion. Enzyme fingerprinting results identified acetyl xylan esterases as key to the enhanced ruminal digestion. FTIR analysis also suggested cross-link cell wall polymers as principal components of indigested fiber residues in feces. Based on structural information from enzymatic fingerprinting and FTIR, enzyme pretreatment to enhance glucose yield from barley straw and alfalfa hay upon exposure to mixed rumen-enzymes was developed. Prehydrolysis effects of recombinant fungal fibrolytic hydrolases were analyzed using microassay in combination with statistical experimental design. Recombinant hemicellulases and auxiliary enzymes initiated degradation of plant structural polysaccharides upon application and improved the in vitro saccharification of alfalfa and barley straw by mixed rumen enzymes. The validation results showed that microassay in combination with statistical experimental design can be successfully used to predict effective enzyme pretreatments that can enhance plant cell wall digestion by mixed rumen enzymes.

Technologically enhanced natural radioactivity around the coal fired power plant

International Nuclear Information System (INIS)

Kovac, J.; Marovic, G.

1997-01-01

In some situations the exposure to natural radiation sources is enhanced as a result to technological developments. Burning of coal is one source of enhanced radiation exposure to naturally occurring elements, particularly radium, thorium and uranium. Most of the radioactive substances are concentrated in the ash and slag, which are heavy and drop to the bottom of a furnace. Lighter fly ash is carried up the chimney and into the atmosphere. The bottom ash and slag are usually deposited in a waste pile, from where some activity may leach into aquifers or be dispersed by wind.The main pathways through which the populations living around coal fired power plants are exposed to enhanced levels of natural radionuclides are inhalation and ingestion of the activity discharged into the Exosphere. For this reason, extensive investigations have been under way for several years in the coal fired power plant in Croatia, which uses an anthracite coal with a higher than usual uranium content. (authors)

Plant-Derived Natural Products as Sources of Anti-Quorum Sensing Compounds

Directory of Open Access Journals (Sweden)

Kok-Gan Chan

2013-05-01

Full Text Available Quorum sensing is a system of stimuli and responses in relation to bacterial cell population density that regulates gene expression, including virulence determinants. Consequently, quorum sensing has been an attractive target for the development of novel anti-infective measures that do not rely on the use of antibiotics. Anti-quorum sensing has been a promising strategy to combat bacterial infections as it is unlikely to develop multidrug resistant pathogens since it does not impose any selection pressure. A number of anti-quorum sensing approaches have been documented and plant-based natural products have been extensively studied in this context. Plant matter is one of the major sources of chemicals in use today in various industries, ranging from the pharmaceutical, cosmetic, and food biotechnology to the textile industries. Just like animals and humans, plants are constantly exposed to bacterial infections, it is therefore logical to expect that plants have developed sophisticated of chemical mechanisms to combat pathogens. In this review, we have surveyed the various types of plant-based natural products that exhibit anti-quorum sensing properties and their anti-quorum sensing mechanisms.

A Theoretical Approach to Engineering a New Enzyme

International Nuclear Information System (INIS)

Anderson, Greg; Gomatam, Ravi; Behera, Raghu N.

2016-01-01

Density function theory, a subfield of quantum mechanics (QM), in combination with molecular mechanics (MM) has opened the way to engineer new artificial enzymes. Herein, we report theoretical calculations done using QM/MM to examine whether the regioselectivity and rate of chlorination of the enzyme chloroperoxidase can be improved by replacing the vanadium of this enzyme with niobium through dialysis. Our calculations show that a niobium substituted chloroperoxidase will be able to enter the initial steps of the catalytic cycle for chlorination. Although the protonation state of the niobium substituted enzyme is calculated to be different from than that of the natural vanadium substituted enzyme, our calculations show that the catalytic cycle can still proceed forward. Using natural bond orbitals, we analyse the electronic differences between the niobium substituted enzyme and the natural enzyme. We conclude by briefly examining how good of a model QM/MM provides for understanding the mechanism of catalysis of chloroperoxidase. (paper)

Structure of a Berberine Bridge Enzyme-Like Enzyme with an Active Site Specific to the Plant Family Brassicaceae

DEFF Research Database (Denmark)

Daniel, Bastian; Wallner, Silvia; Steiner, Barbara

2016-01-01

Berberine bridge enzyme-like (BBE-like) proteins form a multigene family (pfam 08031), which is present in plants, fungi and bacteria. They adopt the vanillyl alcohol-oxidase fold and predominantly show bi-covalent tethering of the FAD cofactor to a cysteine and histidine residue, respectively....... The Arabidopsis thaliana genome was recently shown to contain genes coding for 28 BBE-like proteins, while featuring four distinct active site compositions. We determined the structure of a member of the AtBBE-like protein family (termed AtBBE-like 28), which has an active site composition that has not been...... be exploited for catalysis. The structure also indicates a shift of the position of the isoalloxazine ring in comparison to other members of the BBE-like family. The dioxygen surrogate chloride was found near the C(4a) position of the isoalloxazine ring in the oxygen pocket, pointing to a rapid reoxidation...

Affinity Crystallography: A New Approach to Extracting High-Affinity Enzyme Inhibitors from Natural Extracts.

Science.gov (United States)

Aguda, Adeleke H; Lavallee, Vincent; Cheng, Ping; Bott, Tina M; Meimetis, Labros G; Law, Simon; Nguyen, Nham T; Williams, David E; Kaleta, Jadwiga; Villanueva, Ivan; Davies, Julian; Andersen, Raymond J; Brayer, Gary D; Brömme, Dieter

2016-08-26

Natural products are an important source of novel drug scaffolds. The highly variable and unpredictable timelines associated with isolating novel compounds and elucidating their structures have led to the demise of exploring natural product extract libraries in drug discovery programs. Here we introduce affinity crystallography as a new methodology that significantly shortens the time of the hit to active structure cycle in bioactive natural product discovery research. This affinity crystallography approach is illustrated by using semipure fractions of an actinomycetes culture extract to isolate and identify a cathepsin K inhibitor and to compare the outcome with the traditional assay-guided purification/structural analysis approach. The traditional approach resulted in the identification of the known inhibitor antipain (1) and its new but lower potency dehydration product 2, while the affinity crystallography approach led to the identification of a new high-affinity inhibitor named lichostatinal (3). The structure and potency of lichostatinal (3) was verified by total synthesis and kinetic characterization. To the best of our knowledge, this is the first example of isolating and characterizing a potent enzyme inhibitor from a partially purified crude natural product extract using a protein crystallographic approach.

Phytochemical investigation of natural and in vitro raised Vṛddhadāruka plants.

Science.gov (United States)

Bharati, Asha Jyoti; Bansal, Yogendra Kumar

2014-01-01

Argyreia nervosa commonly known as elephant creeper (English) and Vṛddhadāruka (Sanskrit) is a woody climber that belongs to the family Convolvulaceae. Seeds of this plant contain hallucinogens including ergot alkaloids and a naturally occurring lysergic acid amide. Traditionally the plant is used in the treatment of gonorrhea, strangury, chronic ulcers, diabetes, anemia and cerebral disorders. The plant is also used as appetitiser, brain tonic, cardiotonic, aphrodisiac. It possesses anti-inflammatory, immunomodulatory, antibacterial, antiviral and antifungal activities. To give an account of information on in vitro regeneration and phytochemical analysis of the plant. Nodal explants were selected for in vitro regeneration. Different aerial parts viz., seeds, natural and in vitro leaf, stem and callus were dried and extracted with different solvents and were subjected to various phytochemical analyses. Different concentrations of 6-benzylaminopurine showed shoot and root initiation. The study of phytochemical screening of different extracts showed the presence of bioactive substances like flavonoids, alkaloids, terpenoids, etc. The study will provide an efficient in vitro protocol for micropropagation as an alternative method to conserve the plant and shows the presence of some important secondary metabolites in the nature grown and in vitro raised plants which can be useful for treatment of various diseases.

Phytochemical investigation of natural and in vitro raised Vṛddhadāruka plants

Directory of Open Access Journals (Sweden)

Asha Jyoti Bharati

2014-01-01

Full Text Available Background: Argyreia nervosa commonly known as elephant creeper (English and Vṛddhadāruka (Sanskrit is a woody climber that belongs to the family Convolvulaceae. Seeds of this plant contain hallucinogens including ergot alkaloids and a naturally occurring lysergic acid amide. Traditionally the plant is used in the treatment of gonorrhea, strangury, chronic ulcers, diabetes, anemia and cerebral disorders. The plant is also used as appetitiser, brain tonic, cardiotonic, aphrodisiac. It possesses anti-inflammatory, immunomodulatory, antibacterial, antiviral and antifungal activities. Objective: To give an account of information on in vitro regeneration and phytochemical analysis of the plant. Materials and Methods: Nodal explants were selected for in vitro regeneration. Different aerial parts viz., seeds, natural and in vitro leaf, stem and callus were dried and extracted with different solvents and were subjected to various phytochemical analyses. Results: Different concentrations of 6-benzylaminopurine showed shoot and root initiation. The study of phytochemical screening of different extracts showed the presence of bioactive substances like flavonoids, alkaloids, terpenoids, etc. Conclusion: The study will provide an efficient in vitro protocol for micropropagation as an alternative method to conserve the plant and shows the presence of some important secondary metabolites in the nature grown and in vitro raised plants which can be useful for treatment of various diseases.

Natural phenomena risk assessment at Rocky Flats Plant

International Nuclear Information System (INIS)

Foppe, T.L.

1985-01-01

A realistic approach is currently being used at the Rocky Flats Plant to assess the risks of natural phenomena events. The methodology addresses frequency of occurrence estimates, damage stress on the facility and vital equipment, material-at-risk, release fractions and source terms, leakpath, dispersion and dosimetric models, risk curves, and an uncertainty analysis. 28 references, 1 figure

Cytochrome P450-Mediated Phytoremediation using Transgenic Plants: A Need for Engineered Cytochrome P450 Enzymes

OpenAIRE

Kumar, Santosh; Jin, Mengyao; Weemhoff, James L

2012-01-01

There is an increasing demand for versatile and ubiquitous Cytochrome P450 (CYP) biocatalysts for biotechnology, medicine, and bioremediation. In the last decade there has been an increase in realization of the power of CYP biocatalysts for detoxification of soil and water contaminants using transgenic plants. However, the major limitations of mammalian CYP enzymes are that they require CYP reductase (CPR) for their activity, and they show relatively low activity, stability, and expression. O...

Soil-to-plant transfer factors of natural radionuclides (226Ra and 40K) in selected Thai medicinal plants.

Science.gov (United States)

Saenboonruang, Kiadtisak; Phonchanthuek, Endu; Prasandee, Kamonkhuan

2018-04-01

A soil-to-plant transfer factor (TF) is an important parameter that could be used to estimate radionuclides levels in medicinal plants. This work reports concentrations of natural radionuclides ( 226 Ra and 40 K) and TFs in six Thai medicinal plants grown in central Thailand using an HPGe gamma ray spectrometer. Either root, leaf, or flower parts of each medicinal plant were selected for use in the investigation according to their practical uses in traditional medicine. The results showed that due to K being essential in plants, 40 K had higher arithmetic means of activity concentrations and geometric means of TFs (geometric standard deviations in parentheses) of 610 ± 260 Bq kg -1 dry weight (DW) and 2.0 (1.4), respectively, than 226 Ra, which had the activity concentrations and TFs of 4.8 ± 2.6 Bq kg -1 DW and 0.17 (1.8), respectively. The results also showed that the leaves of medicinal plants had higher activity concentrations and TFs than root and flower parts, probably due to higher metabolic activities in leaves. Furthermore, there was good agreement between the results from the current work and other similar reports on medicinal plants. The information obtained from this work could strengthen knowledge of natural radionuclides in plants and particularly increase available TF data on Thai medicinal plants. Copyright © 2018 Elsevier Ltd. All rights reserved.

Current concepts on selected plant secondary metabolites with promising inhibitory effects against enzymes linked to Alzheimer's disease.

Science.gov (United States)

Orhan, I Erdogan

2012-01-01

Alzheimer's disease (AD) has become one of the deadliest diseases for human beings with special incidence in elderly population. It is a progressive neurodegenerative disease and the most prevalent cause of dementia. The neuropathology of AD has not been fully elucidated yet, however, cholinergic hypothesis is the most accepted theory nowadays, resulting from the cholinergic deficit emerging in the brains of AD patients. Shortage of the neurotransmitters, acetylcholine and butyrylcholine has been demonstrated, and therefore, inhibition of the enzymes; acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) that break down acetylcholine and butyrylcholine has become a standard approach for AD treatment. However, cholinesterase inhibitors are only effective in symptomatic treatment and have no ability to impede the disease. The pathogenesis of AD is highly complex and another hypothesis is the formation of amyloid plaques containing beta-amyloid peptide, which causes neurolesions in the brains of AD patients. Beta-amyloid peptide is generated after the sequential cleavage of amyloid precursor protein, especially by the beta- and gamma-secretase in the amyloidogenic pathway. The secretases involved in the processing of amyloid precursor protein are of particular interest and, consequently, the inhibition of secretase enzyme family of protease type has become another desired treatment strategy for AD. On the other hand, medicinal plants are attractive sources for drug research and development as they produce chemically-varying molecules with preferred biological activities. The aim of this article is to review the available data on selected inhibitors from plant secondary metabolites with emphasis on cholinesterase, prolyl endopeptidase, and secretase enzyme families as being the current treatments of AD.

Natural enemies drive geographic variation in plant defenses

DEFF Research Database (Denmark)

Zuest, Tobias; Heichinger, Christian; Grossniklaus, Ueli

2012-01-01

Plants defend themselves against attack by natural enemies, and these defenses vary widely across populations. However, whether communities of natural enemies are a sufficiently potent force to maintain polymorphisms in defensive traits is largely unknown. Here, we exploit the genetic resources...... of Arabidopsis thaliana, coupled with 39 years of field data on aphid abundance, to (i) demonstrate that geographic patterns in a polymorphic defense locus (GS-ELONG) are strongly correlated with changes in the relative abundance of two specialist aphids; and (ii) demonstrate differential selection by the two...... aphids on GS-ELONG, using a multigeneration selection experiment. We thereby show a causal link between variation in abundance of the two specialist aphids and the geographic pattern at GS-ELONG, which highlights the potency of natural enemies as selective forces....

Remediation Using Plants and Plant Enzymes: A Progress Report

National Research Council Canada - National Science Library

1995-01-01

.... In every case, the sources are plants growing near the sediment. The use of plants for remediation of hazardous materials such as TNT or other munitions like RDX and HMX has led to a new approach to remediation-- phytoremediation...

Plants as natural antioxidants for meat products

Science.gov (United States)

Tomović, V.; Jokanović, M.; Šojić, B.; Škaljac, S.; Ivić, M.

2017-09-01

The meat industry is demanding antioxidants from natural sources to replace synthetic antioxidants because of the negative health consequences or beliefs regarding some synthetic ones. Plants materials provide good alternatives. Spices and herbs, generally used for their flavouring characteristics, can be added to meat products in various forms: whole, ground, or as isolates from their extracts. These natural antioxidants contain some active compounds, which exert antioxidative potential in meat products. This antioxidant activity is most often due to phenolic acids, phenolic diterpenes, flavonoids and volatile oils. Each of these compounds often has strong H-donating activity, thus making them extremely effective antioxidants; some compounds can chelate metals and donate H to oxygen radicals, thus slowing oxidation via two mechanisms. Numerous studies have demonstrated the efficacy of natural antioxidants when used in meat products. Based on this literature review, it can be concluded that natural antioxidants are added to fresh and processed meat and meat products to delay, retard, or prevent lipid oxidation, retard development of off-flavours (rancidity), improve colour stability, improve microbiological quality and extend shelf-life, without any damage to the sensory or nutritional properties.

Naturalization of introduced plants: ecological drivers of biogeographic patterns

Czech Academy of Sciences Publication Activity Database

Richardson, D. M.; Pyšek, Petr

2012-01-01

Roč. 196, č. 2 (2012), s. 383-396 ISSN 0028-646X R&D Projects: GA ČR(CZ) GAP504/11/1028 Institutional support: RVO:67985939 Keywords : plant invasions * naturalization * macroecological patterns Subject RIV: EF - Botanics Impact factor: 6.736, year: 2012

NPACT: Naturally Occurring Plant-based Anti-cancer Compound-Activity-Target database.

Science.gov (United States)

Mangal, Manu; Sagar, Parul; Singh, Harinder; Raghava, Gajendra P S; Agarwal, Subhash M

2013-01-01

Plant-derived molecules have been highly valued by biomedical researchers and pharmaceutical companies for developing drugs, as they are thought to be optimized during evolution. Therefore, we have collected and compiled a central resource Naturally Occurring Plant-based Anti-cancer Compound-Activity-Target database (NPACT, http://crdd.osdd.net/raghava/npact/) that gathers the information related to experimentally validated plant-derived natural compounds exhibiting anti-cancerous activity (in vitro and in vivo), to complement the other databases. It currently contains 1574 compound entries, and each record provides information on their structure, manually curated published data on in vitro and in vivo experiments along with reference for users referral, inhibitory values (IC(50)/ED(50)/EC(50)/GI(50)), properties (physical, elemental and topological), cancer types, cell lines, protein targets, commercial suppliers and drug likeness of compounds. NPACT can easily be browsed or queried using various options, and an online similarity tool has also been made available. Further, to facilitate retrieval of existing data, each record is hyperlinked to similar databases like SuperNatural, Herbal Ingredients' Targets, Comparative Toxicogenomics Database, PubChem and NCI-60 GI(50) data.

NPACT: Naturally Occurring Plant-based Anti-cancer Compound-Activity-Target database

Science.gov (United States)

Mangal, Manu; Sagar, Parul; Singh, Harinder; Raghava, Gajendra P. S.; Agarwal, Subhash M.

2013-01-01

Plant-derived molecules have been highly valued by biomedical researchers and pharmaceutical companies for developing drugs, as they are thought to be optimized during evolution. Therefore, we have collected and compiled a central resource Naturally Occurring Plant-based Anti-cancer Compound-Activity-Target database (NPACT, http://crdd.osdd.net/raghava/npact/) that gathers the information related to experimentally validated plant-derived natural compounds exhibiting anti-cancerous activity (in vitro and in vivo), to complement the other databases. It currently contains 1574 compound entries, and each record provides information on their structure, manually curated published data on in vitro and in vivo experiments along with reference for users referral, inhibitory values (IC50/ED50/EC50/GI50), properties (physical, elemental and topological), cancer types, cell lines, protein targets, commercial suppliers and drug likeness of compounds. NPACT can easily be browsed or queried using various options, and an online similarity tool has also been made available. Further, to facilitate retrieval of existing data, each record is hyperlinked to similar databases like SuperNatural, Herbal Ingredients’ Targets, Comparative Toxicogenomics Database, PubChem and NCI-60 GI50 data. PMID:23203877

Contrasting natural regeneration and tree planting in fourteen North American cities

Science.gov (United States)

David J. Nowak

2012-01-01

Field data from randomly located plots in 12 cities in the United States and Canada were used to estimate the proportion of the existing tree population that was planted or occurred via natural regeneration. In addition, two cities (Baltimore and Syracuse) were recently re-sampled to estimate the proportion of newly established trees that were planted. Results for the...

Plant Formate Dehydrogenase

Energy Technology Data Exchange (ETDEWEB)

John Markwell

2005-01-10

The research in this study identified formate dehydrogenase, an enzyme that plays a metabolic role on the periphery of one-carbon metabolism, has an unusual localization in Arabidopsis thaliana and that the enzyme has an unusual kinetic plasticity. These properties make it possible that this enzyme could be engineered to attempt to engineer plants with an improved photosynthetic efficiency. We have produced transgenic Arabidopsis and tobacco plants with increased expression of the formate dehydrogenase enzyme to initiate further studies.

Optimization of the Production of 1-Phenylethanol Using Enzymes from Flowers of Tea (Camellia sinensis Plants

Directory of Open Access Journals (Sweden)

Fang Dong

2017-01-01

Full Text Available 1-Phenylethanol (1PE can be used as a fragrance in food flavoring and cosmetic industries and as an intermediate in the pharmaceutical industry. 1PE can be synthesized from acetophenone, and the cost of 1PE is higher than the cost of acetophenone. Therefore, it is important to establish an effective and low-cost approach for producing 1PE. Our previous studies found that tea (Camellia sinensis flowers, which are an abundant and waste resource, contained enzymes that could transform acetophenone to 1PE. In the present study, we extracted crude enzymes from tea flowers and optimized the production conditions of 1PE using response surface methodology. The optimized conditions were an extraction pH of 7.0, a reaction pH of 5.3, a reaction temperature of 55 °C, a reaction time of 100 min, a coenzyme NADPH concentration of 3.75 μmol/mL in the reaction assay, and a substrate acetophenone concentration of 1.25 μmol/mL in the reaction assay. The results provide essential information for future industrial 1PE production using plant-derived enzymes.

Greenhouse gas emission measurement and economic analysis of Iran natural gas fired power plants

International Nuclear Information System (INIS)

Shahsavari Alavijeh, H.; Kiyoumarsioskouei, A.; Asheri, M.H.; Naemi, S.; Shahsavari Alavije, H.; Basirat Tabrizi, H.

2013-01-01

This study attempts to examine the natural gas fired power plants in Iran. The required data from natural gas fired power plants were gathered during 2008. The characteristics of thirty two gas turbine power plants and twenty steam power plants have been measured. Their emission factor values were then compared with the standards of Energy Protection Agency, Euro Union and World Bank. Emission factors of gas turbine and steam power plants show that gas turbine power plants have a better performance than steam power plants. For economic analysis, fuel consumption and environmental damages caused by the emitted pollutants are considered as cost functions; and electricity sales revenue are taken as benefit functions. All of these functions have been obtained according to the capacity factor. Total revenue functions show that gas turbine and steam power plants are economically efficient at 98.15% and 90.89% of capacity factor, respectively; this indicates that long operating years of power plants leads to reduction of optimum capacity factor. The stated method could be implemented to assess the economic status of a country’s power plants where as efficient capacity factor close to one means that power plant works in much better condition. - Highlights: • CO 2 and NO x emissions of Iran natural gas fired power plants have been studied. • CO 2 and NO x emission factors are compared with EPA, EU and World Bank standards. • Costs and benefit as economic functions are obtained according to capacity factor. • Maximum economic profit is obtained for gas turbine and steam power plants. • Investment in CO 2 reduction is recommended instead of investment in NO x reduction

Degradation of pheromone and plant volatile components by a same odorant-degrading enzyme in the cotton leafworm, Spodoptera littoralis.

Directory of Open Access Journals (Sweden)

Nicolas Durand

Full Text Available Odorant-Degrading Enzymes (ODEs are supposed to be involved in the signal inactivation step within the olfactory sensilla of insects by quickly removing odorant molecules from the vicinity of the olfactory receptors. Only three ODEs have been both identified at the molecular level and functionally characterized: two were specialized in the degradation of pheromone compounds and the last one was shown to degrade a plant odorant.Previous work has shown that the antennae of the cotton leafworm Spodoptera littoralis, a worldwide pest of agricultural crops, express numerous candidate ODEs. We focused on an esterase overexpressed in males antennae, namely SlCXE7. We studied its expression patterns and tested its catalytic properties towards three odorants, i.e. the two female sex pheromone components and a green leaf volatile emitted by host plants.SlCXE7 expression was concomitant during development with male responsiveness to odorants and during adult scotophase with the period of male most active sexual behaviour. Furthermore, SlCXE7 transcription could be induced by male exposure to the main pheromone component, suggesting a role of Pheromone-Degrading Enzyme. Interestingly, recombinant SlCXE7 was able to efficiently hydrolyze the pheromone compounds but also the plant volatile, with a higher affinity for the pheromone than for the plant compound. In male antennae, SlCXE7 expression was associated with both long and short sensilla, tuned to sex pheromones or plant odours, respectively. Our results thus suggested that a same ODE could have a dual function depending of it sensillar localisation. Within the pheromone-sensitive sensilla, SlCXE7 may play a role in pheromone signal termination and in reduction of odorant background noise, whereas it could be involved in plant odorant inactivation within the short sensilla.

Heterologous expression, purification, crystallization and preliminary X-ray analysis of raucaffricine glucosidase, a plant enzyme specifically involved in Rauvolfia alkaloid biosynthesis

Energy Technology Data Exchange (ETDEWEB)

Ruppert, Martin [Department of Pharmaceutical Biology, Institute of Pharmacy, Johannes Gutenberg-University Mainz, Staudinger Weg 5, D-55099 Mainz (Germany); Panjikar, Santosh [European Molecular Biology Laboratory Hamburg, Outstation Deutsches Elektronen-Synchrotron, Notkestrasse 85, D-22603 Hamburg (Germany); Barleben, Leif [Department of Pharmaceutical Biology, Institute of Pharmacy, Johannes Gutenberg-University Mainz, Staudinger Weg 5, D-55099 Mainz (Germany); Stöckigt, Joachim [Department of Pharmaceutical Biology, Institute of Pharmacy, Johannes Gutenberg-University Mainz, Staudinger Weg 5, D-55099 Mainz (Germany); College of Pharmaceutical Sciences, Zhejiang University, 353 Yan An Road, 310031 Hangzhou (China)

2006-03-01

Raucaffricine glucosidase, an enzyme involved in the biosynthesis of monoterpenoid indole alkaloids in the plant Rauvolfia serpentina, was crystallized by the hanging-drop vapour-diffusion method using PEG4000 as precipitant. The crystals diffract to 2.3 Å resolution and belong to space group I222. Raucaffricine glucosidase (RG) is an enzyme that is specifically involved in the biosynthesis of indole alkaloids from the plant Rauvolfia serpentina. After heterologous expression in Escherichia coli cells, crystals of RG were obtained by the hanging-drop vapour-diffusion technique at 293 K with 0.3 M ammonium sulfate, 0.1 M sodium acetate pH 4.6 buffer and 11% PEG 4000 as precipitant. Crystals belong to space group I222 and diffract to 2.30 Å, with unit-cell parameters a = 102.8, b = 127.3, c = 215.8 Å.

Heterologous expression, purification, crystallization and preliminary X-ray analysis of raucaffricine glucosidase, a plant enzyme specifically involved in Rauvolfia alkaloid biosynthesis

International Nuclear Information System (INIS)

Ruppert, Martin; Panjikar, Santosh; Barleben, Leif; Stöckigt, Joachim

2006-01-01

Raucaffricine glucosidase, an enzyme involved in the biosynthesis of monoterpenoid indole alkaloids in the plant Rauvolfia serpentina, was crystallized by the hanging-drop vapour-diffusion method using PEG4000 as precipitant. The crystals diffract to 2.3 Å resolution and belong to space group I222. Raucaffricine glucosidase (RG) is an enzyme that is specifically involved in the biosynthesis of indole alkaloids from the plant Rauvolfia serpentina. After heterologous expression in Escherichia coli cells, crystals of RG were obtained by the hanging-drop vapour-diffusion technique at 293 K with 0.3 M ammonium sulfate, 0.1 M sodium acetate pH 4.6 buffer and 11% PEG 4000 as precipitant. Crystals belong to space group I222 and diffract to 2.30 Å, with unit-cell parameters a = 102.8, b = 127.3, c = 215.8 Å

Uptake of the natural radioactive gas radon by an epiphytic plant.

Science.gov (United States)

Li, Peng; Zhang, Ruiwen; Gu, Mintian; Zheng, Guiling

2018-01-15

Radon ( 222 Rn) is a natural radioactive gas and the major radioactive contributor to human exposure. The present effective ways to control Rn contamination are ventilation and adsorption with activated carbon. Plants are believed to be negligible in reducing airborne Rn. Here, we found epiphytic Tillandsia brachycaulos (Bromeliaceae) was effective in reducing airborne Rn via the leaves. Rn concentrations in the Rn chamber after Tillandsia plant treatments decreased more than those in the natural situation. The specialized foliar trichomes densely covering Tillandsia leaves play a major role in the uptake of Rn because the amplified rough leaf surface area facilitates deposition of Rn progeny particles and the powdery epicuticular wax layer of foliar trichomes uptakes liposoluble Rn. The results provide us a new ecological strategy for Rn contamination control, and movable epiphytic Tillandsia plants can be applied widely in Rn removal systems. Copyright © 2017 Elsevier B.V. All rights reserved.

Proof of the Wave Nature of Plants

Science.gov (United States)

Wagner, Orvin

2008-03-01

I assume plants operate with a set of frequencies. These frequencies and the means of these frequencies are equal in all directions. We can then write (vh/λ)avh=(vv/λ)avv where the subscripts h and v represent horizontal and vertical respectively and av is average,. or vv/vh=(1/λh)av/(1/λv)av. I use an internodal spacing as λ/2 or the the distance between adjacent branches, leaves, etc. The ratios, vv/vh, are ratios of small integers for sufficient samplings. For example, for Ponderosa pine the ratio is 3/1 or for delicious apple 4/3. Note that these ratios represent the shape of the tree or other plant and their interactions with gravity. These ratios are derivable by other means such as use the ratio of # of horizontal needles per unit length from a horizontal sample to the # of needles per unit length from a vertical sample from p-pine. Or measure the vertical and horizontal velocities. My literature provides many other proofs of the wave nature of plants. I suggest that the waves in and related waves outside of plants (outside 4.9 m/s) are a dark matter related since they travel at such low velocities. See my present web site at home.budget.net/˜oedphd.

The Complexity of Bioactive Natural Products in Plants

DEFF Research Database (Denmark)

Frisch, Tina

Plants produce a diverse range of bioactive natural products promoting their fitness. These specialized metabolites may serve as chemical defence against herbivores and pathogens and may inhibit the growth and development of competing species. Hydroxynitrile glucosides and glucosinolates are two...... classes of defence compounds, which have diverging properties, but also share common biosynthetic features. Hydroxynitrile glucosides are produced in species across the plant kingdom, whereas glucosinolates are found almost exclusively within the Brassicales, which generally does not contain...... hydroxynitrile glucosides. This division has raised questions regarding possible evolutionary relationships between the biosynthetic pathways. The very rare co-occurrence of hydroxynitrile glucosides and glucosinolates found in Alliaria petiolata (garlic mustard, løgkarse) and Carica papaya (papaya) makes...

Compounds from silicones alter enzyme activity in curing barnacle glue and model enzymes.

Science.gov (United States)

Rittschof, Daniel; Orihuela, Beatriz; Harder, Tilmann; Stafslien, Shane; Chisholm, Bret; Dickinson, Gary H

2011-02-17

Attachment strength of fouling organisms on silicone coatings is low. We hypothesized that low attachment strength on silicones is, in part, due to the interaction of surface available components with natural glues. Components could alter curing of glues through bulk changes or specifically through altered enzyme activity. GC-MS analysis of silicone coatings showed surface-available siloxanes when the coatings were gently rubbed with a cotton swab for 15 seconds or given a 30 second rinse with methanol. Mixtures of compounds were found on 2 commercial and 8 model silicone coatings. The hypothesis that silicone components alter glue curing enzymes was tested with curing barnacle glue and with commercial enzymes. In our model, barnacle glue curing involves trypsin-like serine protease(s), which activate enzymes and structural proteins, and a transglutaminase which cross-links glue proteins. Transglutaminase activity was significantly altered upon exposure of curing glue from individual barnacles to silicone eluates. Activity of purified trypsin and, to a greater extent, transglutaminase was significantly altered by relevant concentrations of silicone polymer constituents. Surface-associated silicone compounds can disrupt glue curing and alter enzyme properties. Altered curing of natural glues has potential in fouling management.

Plant regeneration of natural tetraploid Trifolium  Hum pratense L

Directory of Open Access Journals (Sweden)

HATICE ÇÖLGEÇEN

2008-01-01

Full Text Available The regeneration of natural tetraploid T. pratense, originated from Erzurum-Turkey, is reported in this study. This plant has low seed setting and hard seed problems due to polyploidy. Hypocotyl, cotyledon, apical meristems, epicotyl and young primary leaves were inoculated on MS and PC-L2 media containing different concentrations of BAP and NAA as growth regulators. The best shoot formation has been observed on explants initiated from apical meristem placed on PC-L2 medium that includes 2 mg dm-3 BAP and 1 mg dm-3 NAA. 94.4% of the shoots originated from calli were rooted on PC-L2 medium with 1 mg dm-3 NAA. In vitro organogénesis has been accomplished in the natural tetraploid T. pratense regenerated plants successively transferred to the field

Plant Research '75

Energy Technology Data Exchange (ETDEWEB)

1975-01-01

Research is reported on stomatal regulation of the gas exchanges between plant and environment; inhibitory effects in flower formation; plant growth and development through hormones; hormone action; development and nitrogen fixation in algae; primary cell wall glycoprotein ectensin; enzymic mechanisms and control of polysaccharide and glycoprotein synthesis; molecular studies of membrane studies; sensory transduction in plants; regulation of formation of protein complexes and enzymes in higher plant cell and mechanism of sulfur dioxide toxicity in plants. (PCS)

Natural radionuclides in soil profiles surrounding the largest coal-fired power plant in Serbia

Directory of Open Access Journals (Sweden)

Tanić Milan N.

2016-01-01

Full Text Available This study evaluates the influence of the largest Serbian coal-fired power plant on radionuclide concentrations in soil profiles up to 50 cm in depth. Thirty soil profiles were sampled from the plant surroundings (up to 10 km distance and analyzed using standard methods for soil physicochemical properties and gamma ray spectrometry for specific activities of natural radionuclides (40K, 226Ra and 232Th. Spatial and vertical distribution of radionuclides was determined and analyzed to show the relations between the specific activities in the soil and soil properties and the most influential factors of natural radionuclide variability were identified. The radiological indices for surface soil were calculated and radiological risk assessment was performed. The measured specific activities were similar to values of background levels for Serbia. The sampling depth did not show any significant influence on specific activities of natural radionuclides. The strongest predictor of specific activities of the investigated radionuclides was soil granulometry. All parameters of radiological risk assessment were below the recommended values and adopted limits. It appears that the coal-fired power plant does not have a significant impact on the spatial and vertical distribution of natural radionuclides in the area of interest, but technologically enhanced natural radioactivity as a consequence of the plant operations was identified within the first 1.5 km from the power plant. [Projekat Ministarstva nauke Republike Srbije br. III43009 i br. III41005

Diversity and strain specificity of plant cell wall degrading enzymes revealed by the draft genome of Ruminococcus flavefaciens FD-1.

Directory of Open Access Journals (Sweden)

Margret E Berg Miller

Full Text Available BACKGROUND: Ruminococcus flavefaciens is a predominant cellulolytic rumen bacterium, which forms a multi-enzyme cellulosome complex that could play an integral role in the ability of this bacterium to degrade plant cell wall polysaccharides. Identifying the major enzyme types involved in plant cell wall degradation is essential for gaining a better understanding of the cellulolytic capabilities of this organism as well as highlighting potential enzymes for application in improvement of livestock nutrition and for conversion of cellulosic biomass to liquid fuels. METHODOLOGY/PRINCIPAL FINDINGS: The R. flavefaciens FD-1 genome was sequenced to 29x-coverage, based on pulsed-field gel electrophoresis estimates (4.4 Mb, and assembled into 119 contigs providing 4,576,399 bp of unique sequence. As much as 87.1% of the genome encodes ORFs, tRNA, rRNAs, or repeats. The GC content was calculated at 45%. A total of 4,339 ORFs was detected with an average gene length of 918 bp. The cellulosome model for R. flavefaciens was further refined by sequence analysis, with at least 225 dockerin-containing ORFs, including previously characterized cohesin-containing scaffoldin molecules. These dockerin-containing ORFs encode a variety of catalytic modules including glycoside hydrolases (GHs, polysaccharide lyases, and carbohydrate esterases. Additionally, 56 ORFs encode proteins that contain carbohydrate-binding modules (CBMs. Functional microarray analysis of the genome revealed that 56 of the cellulosome-associated ORFs were up-regulated, 14 were down-regulated, 135 were unaffected, when R. flavefaciens FD-1 was grown on cellulose versus cellobiose. Three multi-modular xylanases (ORF01222, ORF03896, and ORF01315 exhibited the highest levels of up-regulation. CONCLUSIONS/SIGNIFICANCE: The genomic evidence indicates that R. flavefaciens FD-1 has the largest known number of fiber-degrading enzymes likely to be arranged in a cellulosome architecture. Functional

Search for bioactive natural products from medicinal plants of Bangladesh.

Science.gov (United States)

Ahmed, Firoj; Sadhu, Samir Kumar; Ishibashi, Masami

2010-10-01

In our continuous search for bioactive natural products from natural resources, we explored medicinal plants of Bangladesh, targeting cancer-related tumor necrosis factor-related apoptosis-inducing ligand-signaling pathway, along with some other biological activities such as prostaglandin inhibitory activity, 1,1-diphenyl-2-picrylhydrazyl free-radical-scavenging activity, and cell growth inhibitory activity. Along with this, we describe a short field study on Sundarbans mangrove forests, Bangladesh, in the review.

Natural radioactivity level in coal and ash collected from Baoji coal-fired power plant

International Nuclear Information System (INIS)

Jia Xiaodan; Lu Xinwei

2006-01-01

Specific activities of natural radionuclides 226 Ra, 232 Th and 40 K were assessed in coal (3 samples), fly ash (17 samples) and bottom ash (6 samples) collected from Baoji coal-fired power plant. This paper analyzed the characteristics of 226 Ra, 232 Th and 40 K contents in bottom ash and fly ash, and studied the concentration factors of these radionuclides in ash in relation to those in coal. The level of natural radionuclides 226 Ra, 232 Th and 40 K of coal collected from Baoji coal-fired power plant are in the range of radionuclides contents of Chinese coal. The natural radioactivity level of fly ash collected from Baoji coal-fired power plant is close to Beijing and Shanghai coal-fired power plants. The paper farther assessed the possibility of fly ash of Baoji coal-fired power plant used as building materials according to the state standard. The results show that there are 29% samples exceeding the state limit when fly ash used as building materials. So the usage of fly ash in building material should be controlled. (authors)

Evolved Control of Natural Plants: Crossing the Reality Gap for User-Defined Steering of Growth and Motion

DEFF Research Database (Denmark)

Hofstadler, Daniel Nicolas; Wahby, Mostafa; Heinrich, Mary Katherine

2017-01-01

Mixing societies of natural and artificial systems can provide interesting and potentially fruitful research targets. Here we mix robotic setups and natural plants in order to steer the motion behavior of plants while growing. The robotic setup uses a camera to observe the plant and uses a pair...... of light sources to trigger phototropic response, steering the plant to user-defined targets. An evolutionary robotic approach is used to design a controller for the setup. Initially, preliminary experiments are performed with a simple predetermined controller and a growing bean plant. The plant behavior......-evolved controller in the real setup controlling a natural bean plant. The results demonstrate a successful crossing of the reality gap in the setup. The success of the approach allows for future extensions to more complex tasks including control of the shape of plants and pattern formation in multiple plant setups....

Subcellular site and nature of intracellular cadmium in plants

International Nuclear Information System (INIS)

Wagner, G.J.

1979-01-01

The mechanisms underlying heavy metal accumulation, toxicity and tolerance in higher plants are poorly understood. Since subcellular processes are undoubtedly involved in all these phenomena, it is of interest to study the extent of, subcellular site of and nature of intracellularly accumulated cadmium in higher plants. Whole plants supplied 109 CdCl 2 or 112 CdSO 4 accumulated Cd into roots and aerial tissues. Preparation of protoplasts from aerial tissue followed by subcellular fractionation of the protoplasts to obtain intact vacuoles, chloroplasts and cytosol revealed the presence of Cd in the cytosol but not in vacuoles or chloroplasts. Particulate materials containing other cell components were also labeled. Of the 109 Cd supplied to plants, 2 to 10% was recovered in both cytosol preparations and in particulate materials. Cytosol contained proteinaceous--Cd complexes, free metal and low molecular weight Cd complexes. Labeling of protoplasts gave similar results. No evidence was obtained for the production of volatile Cd complexes in tobacco

Bacteria Associated to Plants Naturally Selected in a Historical PCB Polluted Soil Show Potential to Sustain Natural Attenuation.

Science.gov (United States)

Vergani, Lorenzo; Mapelli, Francesca; Marasco, Ramona; Crotti, Elena; Fusi, Marco; Di Guardo, Antonio; Armiraglio, Stefano; Daffonchio, Daniele; Borin, Sara

2017-01-01

The exploitation of the association between plants and microorganisms is a promising approach able to boost natural attenuation processes for soil clean-up in vast polluted areas characterized by mixed chemical contamination. We aimed to explore the selection of root-associated bacterial communities driven by different plant species spontaneously established in abandoned agricultural soils within a historical polluted site in north Italy. The site is highly contaminated by chlorinated persistent organic pollutants, mainly constituted by polychlorobiphenyls (PCBs), together with heavy metals and metalloids, in variable concentrations and uneven distribution. The overall structure of the non-vegetated and root-associated soil fractions bacterial communities was described by high-throughput sequencing of the 16S rRNA gene, and a collection of 165 rhizobacterial isolates able to use biphenyl as unique carbon source was assayed for plant growth promotion (PGP) traits and bioremediation potential. The results showed that the recruitment of specific bacterial communities in the root-associated soil fractions was driven by both soil fractions and plant species, explaining 21 and 18% of the total bacterial microbiome variation, respectively. PCR-based detection in the soil metagenome of bacterial bphA gene, encoding for the biphenyl dioxygenase α subunit, indicated that the soil in the site possesses metabolic traits linked to PCB degradation. Biphenyl-utilizing bacteria isolated from the rhizosphere of the three different plant species showed low phylogenetic diversity and well represented functional traits, in terms of PGP and bioremediation potential. On average, 72% of the strains harbored the bphA gene and/or displayed catechol 2,3-dioxygenase activity, involved in aromatic ring cleavage. PGP traits, including 1-aminocyclopropane-1-carboxylic acid deaminase activity potentially associated to plant stress tolerance induction, were widely distributed among the isolates

Bacteria Associated to Plants Naturally Selected in a Historical PCB Polluted Soil Show Potential to Sustain Natural Attenuation

KAUST Repository

Vergani, Lorenzo

2017-07-25

The exploitation of the association between plants and microorganisms is a promising approach able to boost natural attenuation processes for soil clean-up in vast polluted areas characterized by mixed chemical contamination. We aimed to explore the selection of root-associated bacterial communities driven by different plant species spontaneously established in abandoned agricultural soils within a historical polluted site in north Italy. The site is highly contaminated by chlorinated persistent organic pollutants, mainly constituted by polychlorobiphenyls (PCBs), together with heavy metals and metalloids, in variable concentrations and uneven distribution. The overall structure of the non-vegetated and root-associated soil fractions bacterial communities was described by high-throughput sequencing of the 16S rRNA gene, and a collection of 165 rhizobacterial isolates able to use biphenyl as unique carbon source was assayed for plant growth promotion (PGP) traits and bioremediation potential. The results showed that the recruitment of specific bacterial communities in the root-associated soil fractions was driven by both soil fractions and plant species, explaining 21 and 18% of the total bacterial microbiome variation, respectively. PCR-based detection in the soil metagenome of bacterial bphA gene, encoding for the biphenyl dioxygenase α subunit, indicated that the soil in the site possesses metabolic traits linked to PCB degradation. Biphenyl-utilizing bacteria isolated from the rhizosphere of the three different plant species showed low phylogenetic diversity and well represented functional traits, in terms of PGP and bioremediation potential. On average, 72% of the strains harbored the bphA gene and/or displayed catechol 2,3-dioxygenase activity, involved in aromatic ring cleavage. PGP traits, including 1-aminocyclopropane-1-carboxylic acid deaminase activity potentially associated to plant stress tolerance induction, were widely distributed among the isolates

Bacteria Associated to Plants Naturally Selected in a Historical PCB Polluted Soil Show Potential to Sustain Natural Attenuation

Directory of Open Access Journals (Sweden)

Lorenzo Vergani

2017-07-01

Full Text Available The exploitation of the association between plants and microorganisms is a promising approach able to boost natural attenuation processes for soil clean-up in vast polluted areas characterized by mixed chemical contamination. We aimed to explore the selection of root-associated bacterial communities driven by different plant species spontaneously established in abandoned agricultural soils within a historical polluted site in north Italy. The site is highly contaminated by chlorinated persistent organic pollutants, mainly constituted by polychlorobiphenyls (PCBs, together with heavy metals and metalloids, in variable concentrations and uneven distribution. The overall structure of the non-vegetated and root-associated soil fractions bacterial communities was described by high-throughput sequencing of the 16S rRNA gene, and a collection of 165 rhizobacterial isolates able to use biphenyl as unique carbon source was assayed for plant growth promotion (PGP traits and bioremediation potential. The results showed that the recruitment of specific bacterial communities in the root-associated soil fractions was driven by both soil fractions and plant species, explaining 21 and 18% of the total bacterial microbiome variation, respectively. PCR-based detection in the soil metagenome of bacterial bphA gene, encoding for the biphenyl dioxygenase α subunit, indicated that the soil in the site possesses metabolic traits linked to PCB degradation. Biphenyl-utilizing bacteria isolated from the rhizosphere of the three different plant species showed low phylogenetic diversity and well represented functional traits, in terms of PGP and bioremediation potential. On average, 72% of the strains harbored the bphA gene and/or displayed catechol 2,3-dioxygenase activity, involved in aromatic ring cleavage. PGP traits, including 1-aminocyclopropane-1-carboxylic acid deaminase activity potentially associated to plant stress tolerance induction, were widely distributed

Long term developments in irradiated natural uranium processing costs. Optimal size and siting of plants

International Nuclear Information System (INIS)

Thiriet, L.

1964-01-01

The aim of this paper is to help solve the problem of the selection of optimal sizes and sites for spent nuclear fuel processing plants associated with power capacity programmes already installed. Firstly, the structure of capital and running costs of irradiated natural uranium processing plants is studied, as well as the influence of plant sizes on these costs and structures. Shipping costs from the production site to the plant must also be added to processing costs. An attempt to reach a minimum cost for the production of a country or a group of countries must therefore take into account both the size and the location of the plants. The foreseeable shipping costs and their structure (freight, insurance, container cost and depreciation), for spent natural uranium are indicated. Secondly, for various annual spent fuel reprocessing programmes, the optimal sizes and locations of the plants are determined. The sensitivity of the results to the basic assumptions relative to processing costs, shipping costs, the starting up year of the plant programme and the length of period considered, is also tested. - this rather complex problem, of a combinative nature, is solved through dynamic programming methods. - It is shown that these methods can also be applied to the problem of selecting the optimal sizes and locations of processing plants for MTR type fuel elements, related to research reactor programmes, as well as to future plutonium element processing plants related to breeder reactors. Thirdly, the case where yearly extraction of the plutonium contained in the irradiated natural uranium is not compulsory is examined; some stockpiling of the fuel is then allowed some years, entailing delayed processing. The load factor of such plants is thus greatly improved with respect to that of plants where the annual plutonium demand is strictly satisfied. By including spent natural uranium stockpiling costs an optimal rhythm of introduction and optimal sizes for spent fuel

EVOLUTIONARY TRANSITIONS IN ENZYME ACTIVITY OF ANT FUNGUS GARDENS

DEFF Research Database (Denmark)

De Fine Licht, Henrik H; Schiøtt, Morten; Mueller, Ulrich G

2010-01-01

an association with a monophyletic clade of specialized symbionts. In conjunction with the transition to specialized symbionts, the ants advanced in colony size and social complexity. Here we provide a comparative study of the functional specialization in extracellular enzyme activities in fungus gardens across...... the attine phylogeny. We show that, relative to sister clades, gardens of higher-attine ants have enhanced activity of protein-digesting enzymes, whereas gardens of leaf-cutting ants also have increased activity of starch-digesting enzymes. However, the enzyme activities of lower-attine fungus gardens...... are targeted primarily towards partial degradation of plant cell walls, reflecting a plesiomorphic state of non-domesticated fungi. The enzyme profiles of the higher-attine and leaf-cutting gardens appear particularly suited to digest fresh plant materials and to access nutrients from live cells without major...

Production of soybean isoflavone genistein in non-legume plants via genetically modified secondary metabolism pathway.

Science.gov (United States)

Liu, Rongrong; Hu, Yuanlei; Li, Jialin; Lin, Zhongping

2007-01-01

Genetic modification of secondary metabolic pathways to produce desirable natural products is an attractive approach in plant biotechnology. In our study, we attempted to produce a typical soybean isoflavone genistein, a well-known health-promoting metabolite, in non-legume plants via genetic engineering. Both overexpression and antisense suppression strategies were used to manipulate the expression of several genes encoding key enzymes in the flavonoids/isoflavonoids pathway in transgenic tobacco, lettuce, and petunia. Introducing soybean isoflavone synthase (IFS) into these plants, which naturally do not produce isoflavonoids due to a lack of this leguminous enzyme, resulted in genistein biosynthesis in tobacco petals, petunia leaves and petals, and lettuce leaves. In tobacco, when flavanone 3-hydroxylase (F3H) expression was suppressed by its antisense gene while soybean IFS was overexpressed at the same time, genistein yield increased prominently. In addition, overexpression of phenylalanine ammonia-lyase (PAL) also led to an enhanced genistein production in tobacco petals and lettuce leaves in the presence of IFS than in the plants that overexpressed only IFS.

Harnessing Biomedical Natural Language Processing Tools to Identify Medicinal Plant Knowledge from Historical Texts.

Science.gov (United States)

Sharma, Vivekanand; Law, Wayne; Balick, Michael J; Sarkar, Indra Neil

2017-01-01

The growing amount of data describing historical medicinal uses of plants from digitization efforts provides the opportunity to develop systematic approaches for identifying potential plant-based therapies. However, the task of cataloguing plant use information from natural language text is a challenging task for ethnobotanists. To date, there have been only limited adoption of informatics approaches used for supporting the identification of ethnobotanical information associated with medicinal uses. This study explored the feasibility of using biomedical terminologies and natural language processing approaches for extracting relevant plant-associated therapeutic use information from historical biodiversity literature collection available from the Biodiversity Heritage Library. The results from this preliminary study suggest that there is potential utility of informatics methods to identify medicinal plant knowledge from digitized resources as well as highlight opportunities for improvement.

Natural gas is more than gas power plants

International Nuclear Information System (INIS)

Lind, Oddvar

2000-01-01

Through the Statpipe gas line at Karmoey, Norway supplies 20% of the natural gas on the European market. The pipeline is 'leaking' a little bit of gas to the local communities at Karmoey and Haugesund. These communities have replaced 65% of their oil consumption with natural gas, which is a fine contribution to a better environment. The supplier of the natural gas, Gasnor ASA in this case, claims an energy efficiency of 90% at the end user because the gas burns directly and the loss in the pipeline is minimal. The efficiency of natural gas utilisation is twice that of the planned gas power stations in West-Norway, subtracting the losses in the electrical network. Gasnor ASA competes with oil suppliers and, if necessary, with electric utilities. The county hospital at Haugesund is quoted as an example. The hospital has two large boilers with dual fuel burners. They have been using natural gas since 1998 because it was worth while both economically and environmentally. The use of natural gas in the transport sector would be very important, but the necessary infrastructure is very little developed. For instance, five diesel-powered ferries on the Boknafjord emit as much NOx as the planned gas power plant at Kaarstoe

Fructan active enzymes (FAZY) activities and biosynthesis of fructooligosaccharides in the vacuoles of Agave tequilana Weber Blue variety plants of different age.

Science.gov (United States)

Mellado-Mojica, Erika; González de la Vara, Luis E; López, Mercedes G

2017-02-01

Biosynthesis of agave fructans occurs in mesontle vacuoles which showed fluctuations in FAZY activities and synthesized a diverse spectrum of fructooligosaccharide isomers. Agave tequilana Weber Blue variety is an important agronomic crop in Mexico. Fructan metabolism in A. tequilana exhibits changes in fructan content, type, degree of polymerization (DP), and molecular structure. Specific activities of vacuolar fructan active enzymes (FAZY) in A. tequilana plants of different age and the biosynthesis of fructooligosaccharides (FOSs) were analyzed in this work. Vacuoles from mesontle (stem) protoplasts were isolated and collected from 2- to 7-year-old plants. For the first time, agave fructans were identified in the vacuolar content by HPAEC-PAD. Several FAZY activities (1-SST, 6-SFT, 6G-FFT, 1-FFT, and FEH) with fluctuations according to the plant age were found in protein vacuolar extracts. Among vacuolar FAZY, 1-SST activities appeared in all plant developmental stages, as well as 1-FFT and FEH activities. The enzymes 6G-FFT and 6-SST showed only minimal activities. Lowest and highest FAZY activities were found in 2- and 6-year-old plants, respectively. Synthesized products (FOS) were analyzed by TLC and HPAEC-PAD. Vacuolar FAZYs yielded large FOS isomers diversity, being 7-year-old plants the ones that synthesized a greater variety of fructans with different DP, linkages, and molecular structures. Based on the above, we are proposing a model for the FAZY activities constituting the FOS biosynthetic pathways in Agave tequilana Weber Blue variety.

The surface science of enzymes

DEFF Research Database (Denmark)

Rod, Thomas Holm; Nørskov, Jens Kehlet

2002-01-01

One of the largest challenges to science in the coming years is to find the relation between enzyme structure and function. Can we predict which reactions an enzyme catalyzes from knowledge of its structure-or from its amino acid sequence? Can we use that knowledge to modify enzyme function......? To solve these problems we must understand in some detail how enzymes interact with reactants from its surroundings. These interactions take place at the surface of the enzyme and the question of enzyme function can be viewed as the surface science of enzymes. In this article we discuss how to describe...... catalysis by enzymes, and in particular the analogies between enzyme catalyzed reactions and surface catalyzed reactions. We do this by discussing two concrete examples of reactions catalyzed both in nature (by enzymes) and in industrial reactors (by inorganic materials), and show that although analogies...

Enzymes and Ecosystems -- Where Do They Overlap?

Science.gov (United States)

Richard E. Dickson

1996-01-01

The whole plant is not the sum of its enzyme systems. This book demonstrates the importance of whole-plant physiology by examining carbon-nitrogen interactions and how these interactions are influenced by demands of the whole plant. In some aspects it is a timely response to the current, strong reductionist trends in plant physiology associated with advances in...

Cadmium phytotoxicity: Quantitative sensitivity relationships between classical endpoints and antioxidative enzyme biomarkers

International Nuclear Information System (INIS)

Rosa Correa, Albertina Xavier da; Roerig, Leonardo Rubi; Verdinelli, Miguel A.; Cotelle, Sylvie; Ferard, Jean-Francois; Radetski, Claudemir Marcos

2006-01-01

In this work, cadmium phytotoxicity and quantitative sensitivity relationships between different hierarchical endpoints in plants cultivated in a contaminated soil were studied. Thus, germination rate, biomass growth and antioxidative enzyme activity (i.e. superoxide dismutase, peroxidase, catalase and glutathione reductase) in three terrestrial plants (Avena sativa L., Brassica campestris L. cv. Chinensis, Lactuca sativa L. cv. hanson) were analyzed. Plant growth tests were carried out according to an International Standard Organization method and the results were analyzed by ANOVA followed by Williams' test. The concentration of Cd 2+ that had the smallest observed significant negative effect (LOEC) on plant biomass was 6.25, 12.5 and 50 mg Cd/kg dry soil for lettuce, oat and Chinese cabbage, respectively. Activity of all enzymes studied increased significantly compared to enzyme activity in plant controls. For lettuce, LOEC values (mg Cd/kg dry soil) for enzymic activity ranged from 0.05 (glutathione reductase) to 0.39 (catalase). For oat, LOEC values (mg Cd/kg dry soil) ranged from 0.19 (for superoxide dismutase and glutathione reductase) to 0.39 (for catalase and peroxidase). For Chinese cabbage, LOEC values (mg Cd/kg dry soil) ranged from 0.19 (peroxidase, catalase and glutathione reductase) to 0.39 (superoxide dismutase). Classical (i.e. germination and biomass) and biochemical (i.e. enzyme activity) endpoints were compared to establish a sensitivity ranking, which was: enzyme activity > biomass > germination rate. For cadmium-soil contamination, the determination of quantitative sensitivity relationships (QSR) between classical and antioxidative enzyme biomarkers showed that the most sensitive plant species have, generally, the lowest QSR values

Identification of the plants use as natural herbal shampoo in Manipur.

Science.gov (United States)

Singh, S R; Phurailatpam, A K; Senjam, P

2014-01-01

A field survey was conducted in the year, 2011 - 12 in Imphal valley of Manipur, on the use of herbs as ingredient sources for the preparation of traditional natural herbal shampoo referred to as 'Chinghi', by Meitei community. Methodological field survey and personal interview of local people aged between 30-70 years of both sexes using standard questionnaires were carried out to collect information on the plants use in the herbal shampoo preparation. The survey revealed the therapeutic application of 35 plant species representing 28 genera and 18 families available in the Imphal valley. Tree species contributed immensely, yielding 38%, while herbs 32%, shrubs 27%, and climbing shrubs 3%, respectively being the record of the total number of plants used as ingredient in herbal shampoo preparation. These natural shampoos are used for a wide range of common hair care like anti-ageing of the hair, blackness, shininess and smoothness of the hair. It is prepared from young leaves and tender stalk of shoot of trees or shrubs, or whole plant of the herbs and fresh fruits boiled with local sticky rice water locally called 'Chinghi'. Fermented lime peel is also used as a herbal shampoo. The study shows details of their scientific, common, and local names, including their family, parts used, habit of the plants, and the benefit to the hair health as a whole.

Facilitating the recovery of natural evergreen forests in South Africa via invader plant stands

Directory of Open Access Journals (Sweden)

Coert J. Geldenhuys

2017-11-01

Full Text Available Contrary to general belief, planted and naturalized stands of introduced species facilitate the recovery of natural evergreen forests and their diversity. Forest rehabilitation actions are often performed at great cost: mature forest species are planted, while species with adaptations to recover effectively and quickly after severe disturbance are ignored; or stands are cleared of invasive alien species before native tree species are planted. By contrast, cost-effective commercial plantation forestry systems generally use fast-growing pioneer tree species introduced from other natural forest regions. Such planted tree stands often facilitate the recovery of shade-tolerant native forest species. This paper provides a brief overview of disturbance-recovery processes at landscape level, and how pioneer stands of both native and introduced tree species develop from monocultures to diverse mature forest communities. It uses one example of a study of how natural forest species from small forest patches of 3 ha in total invaded a 90-ha stand of the invasive Black wattle, Acacia mearnsii, over a distance of 3.1 ha at Swellendam near Cape Town, South Africa. The study recorded 329 forest species clusters across the wattle stand: more large clusters closer to and more smaller clusters further away from natural forest patches. The 28 recorded forest species (of potentially 40 species in the surrounding forest patches included 79% tree and 21% shrub species. Colonizing forest species had mostly larger fleshy fruit and softer small seeds, and were dispersed by mostly birds and primate species. Maturing forest trees within developing clusters in the wattle stand became a source for forest regeneration away from the clusters, showing different expansion patterns. Four sets of fenced-unfenced plots in the wattle stand showed the impact of browsing by livestock, antelope, rodents and insects on the successful establishment of regenerating forest species, and the

Nonnative invasive plants: Maintaining biotic and soceioeconomic integrity along the urban-rural-natural gradient

Science.gov (United States)

Cynthia D. Huebner; David J. Nowak; Richard V. Pouyat; Allison R. Bodine

2012-01-01

In this chapter, we evaluate nonnative invasive plant species of the urban-rural-natural area gradient in order to reduce negative impacts of invasive plants on native species and ecosystems. This evaluation includes addressing (i) the concept of urban areas as the primary source of invasive plant species and characteristics of urban nonnative plants, including their...

Naturally seeded versus planted ponderosa pine seedlings in group-selection openings

Science.gov (United States)

Philip M. McDonald; Gary Fiddler; Martin Ritchie; Paula Anderson

2009-01-01

The purpose of this article was to determine whether natural regeneration or planted seedlings should be used in group-selection openings. The answer dependson the survival and growth rate of both types of seedlings, and that could depend on the size of the openings and the effect of trees on their edge. In thisside-by-side study, the natural pine seedlings originated...

Passive safety systems and natural circulation in water cooled nuclear power plants

International Nuclear Information System (INIS)

2009-11-01

Nuclear power produces 15% of the world's electricity. Many countries are planning to either introduce nuclear energy or expand their nuclear generating capacity. Design organizations are incorporating both proven means and new approaches for reducing the capital costs of their advanced designs. In the future most new nuclear plants will be of evolutionary design, often pursuing economies of scale. In the longer term, innovative designs could help to promote a new era of nuclear power. Since the mid-1980s it has been recognized that the application of passive safety systems (i.e. those whose operation takes advantage of natural forces such as convection and gravity), can contribute to simplification and potentially improve economics of new nuclear power plant designs. The IAEA Conference on The Safety of Nuclear Power: Strategy for the Future, which was convened in 1991, noted that for new plants 'the use of passive safety features is a desirable method of achieving simplification and increasing the reliability of the performance of essential safety functions, and should be used wherever appropriate'. Some new designs also utilize natural circulation as a means to remove core power during normal operation. The use of passive systems can eliminate the costs associated with the installation, maintenance, and operation of active systems that require multiple pumps with independent and redundant electric power supplies. However, considering the weak driving forces of passive systems based on natural circulation, careful design and analysis methods must be employed to ensure that the systems perform their intended functions. To support the development of advanced water cooled reactor designs with passive systems, investigations of natural circulation are conducted in several IAEA Member States with advanced reactor development programmes. To foster international collaboration on the enabling technology of passive systems that utilize natural circulation, the IAEA

Capital and operating costs of irradiated natural uranium reprocessing plants

International Nuclear Information System (INIS)

Thiriet, L.; Jouannaud, C.; Couture, J.; Duboz, J.

1966-01-01

This paper presents first a method of analysing natural uranium reprocessing plants investment costs (method similar to LANG and BACH well known in the fuel oil industry) and their operating costs (analysed according to their economic type). This method helps establishing standard cost structures for these plants, allowing thus comparisons between existing or planned industrial facilities. It also helps evaluating the foreseeable consequences of technical progress. Some results obtained are given, concerning: the investment costs sensitivity to the various technical parameters defining the fuel and their comparison according to the country or the economic area taken into account. Finally, the influence of the plants size on their investment costs is shown. (author) [fr

Natural transformation in plant breeding - a biotechnological platform for quality improvement of ornamental, agricultural and medicinal plants

DEFF Research Database (Denmark)

Lütken, Henrik Vlk; Hegelund, Josefine Nymark; Himmelboe, Martin

2015-01-01

Compactness is a desirable trait in ornamental plant breeding because it is preferred by producers, distributors and consumers. Presently, in ornamental plant production growth of many potted plants is regulated by application of chemical growth retardants, several of which are harmful to both...... (rol)-genes rolA, rolB, rolC and rolD among 18 ORFs, into the plant genome. Infection of plants by A. rhizogenes induces hairy roots, from which shoots containing rol-genes can be regenerated. Natural transformation with A. rhizogenes reveals very promising results in several plant species and can...... be useful in a broader range of application than ornamental breeding. One important aspect of this technology is that the hairy roots can be used directly in the selection proceß as a primary indicator of a succeßful transformation. Thus the technology avoids use of undesired antibiotic resistance marker...

Vanillin biosynthetic pathways in plants.

Science.gov (United States)

Kundu, Anish

2017-06-01

The present review compiles the up-to-date knowledge on vanillin biosynthesis in plant systems to focus principally on the enzymatic reactions of in planta vanillin biosynthetic pathway and to find out its impact and prospect in future research in this field. Vanillin, a very popular flavouring compound, is widely used throughout the world. The principal natural resource of vanillin is the cured vanilla pods. Due to the high demand of vanillin as a flavouring agent, it is necessary to explore its biosynthetic enzymes and genes, so that improvement in its commercial production can be achieved through metabolic engineering. In spite of significant advancement in elucidating vanillin biosynthetic pathway in the last two decades, no conclusive demonstration had been reported yet for plant system. Several biosynthetic enzymes have been worked upon but divergences in published reports, particularly in characterizing the crucial biochemical steps of vanillin biosynthesis, such as side-chain shortening, methylation, and glucoside formation and have created a space for discussion. Recently, published reviews on vanillin biosynthesis have focused mainly on the biotechnological approaches and bioconversion in microbial systems. This review, however, aims to compile in brief the overall vanillin biosynthetic route and present a comparative as well as comprehensive description of enzymes involved in the pathway in Vanilla planifolia and other plants. Special emphasis has been given on the key enzymatic biochemical reactions that have been investigated extensively. Finally, the present standpoint and future prospects have been highlighted.

Enzyme Inhibitory and Molecular Docking Studies on Some Organic Molecules of Natural Occurrence

International Nuclear Information System (INIS)

Abbasi, M. A.; Hussain, G.; Rehman, A. U.; Shahwar, D.; Mohyuddin, A.; Ashraf, M.; Rahman, J.; Lodhi, M. A.; Khan, F. A.

2016-01-01

In the present study, in vitro enzyme inhibitory studies on cinchonidine (1), cinchonine (2), quinine (3), noscapine (narcotine, 4) and santonine (5) were carried out. The various enzymes included in the study were lipoxygenase, xanthine oxidase, acetyl cholinesterase, butyryl cholinesterase and protease. The results revealed that 2, 3, and 4 were moderate active against lipoxygenase and xanthine oxidase enzymes. The molecule 3 possessed weak activity against butyryl cholinesterase enzyme while remaining molecules were inactive against this enzyme. However, all these compounds were inactive against acetyl cholinestrase and protease enzymes. The synthesized compounds were computationally docked into the active site of lipoxygenase enzyme. The compounds 3 and 4 showed decent interactions, hence strengthening the observed results. (author)

Enzyme recycling in lignocellulosic biorefineries

DEFF Research Database (Denmark)

Jørgensen, Henning; Pinelo, Manuel

2017-01-01

platform. Cellulases are the most important enzymes required in this process, but the complex nature of lignocellulose requires several other enzymes (hemicellulases and auxiliary enzymes) for efficient hydrolysis. Enzyme recycling increases the catalytic productivity of the enzymes by reusing them...... for several batches of hydrolysis, and thereby reduces the overall cost associated with the hydrolysis. Research on this subject has been ongoing for many years and several promising technologies and methods have been developed and demonstrated. But only in a very few cases have these technologies been...... upscaled and tested in industrial settings, mainly because of many difficulties with recycling of enzymes from the complex lignocellulose hydrolyzate at industrially relevant conditions, i.e., high solids loadings. The challenges are associated with the large number of different enzymes required...

Oxidative enzymes activity in sugarcane juice as a function of the planting system

Directory of Open Access Journals (Sweden)

Tadeu Alcides Marques

2013-03-01

Full Text Available In Brazil, the largest producer of sugarcane in the world, the industrial process transforms this crop into ethanol and/or granulated sugar. Some cultivars exhibit enzymatic browning in the extracted sugarcane juice at levels harmful to the manufacturing process of white granulated sugar. The objective of this study was to assess the effect of sugarcane straw used as soil coverage, the use of different planting systems, and treatments with hydrogel polymer on enzymatic activity. The cultivar RB 86 7515 was sampled for 8 months; the first sample was obtained by cutting the upper portion of the stalk at the internode, which was taken to the laboratory for determination of the enzymatic activity of polyphenoloxidase (PPO and peroxidase (POD. The soil coverage with different forms of straw as well as the planting systems did not change the enzymatic activity of polyphenoloxidase (PPO and peroxidase (POD. The polyphenoloxidase (PPO activity increased with the use of a polymer due to increased polyphenoloxidase (PPO activity in the groove system. The enzymes studied showed changes in activity during the experimental period. The production of sugar at the end of the season (August to November avoids the periods of highest enzymatic activity.

Plant management in natural areas: balancing chemical, mechanical, and cultural control methods

Science.gov (United States)

Steven Manning; James. Miller

2011-01-01

After determining the best course of action for control of an invasive plant population, it is important to understand the variety of methods available to the integrated pest management professional. A variety of methods are now widely used in managing invasive plants in natural areas, including chemical, mechanical, and cultural control methods. Once the preferred...

Potential of plant growth promoting rhizobacteria and chemical fertilizers on soil enzymes and plant growth

International Nuclear Information System (INIS)

Nosheen, A.; Bano, A.

2014-01-01

The present investigation deals with the role of Plant Growth Promoting Rhizobacteria and chemical fertilizers alone or in combination on urease, invertase and phosphatase activities of rhizospheric soil and also on general impact on growth of safflower cvv. Thori and Saif-32. The PGPR (Azospirillum brasilense and Azotobacter vinelandii) were applied at 10/sup 6/ cells/mL as seed inoculation prior to sowing. Chemical fertilizers were applied at full (Urea 60 Kg ha/sup -1/ and Diammonium phosphate (DAP) 30 Kg ha/sup -1/), half (Urea 30 Kg ha/sup -1/ and DAP 15 Kg ha/sup -1/) and quarter doses (Urea 15 Kg ha-1 and DAP 7.5 Kg ha/sup -1/) during sowing. The chemical fertilizers and PGPR enhanced urease and invertase activities of soil. Presence of PGPR in combination with quarter and half doses of chemical fertilizers further augmented their effect on soil enzymes activities. The soil phosphatase activity was greater in Azospirillum and Azotobacter in combination with half dose of chemical fertilizers. Maximum increase in leaf melondialdehyde content was recorded in full dose of chemical fertilizers whereas coinoculation treatment exhibited significant reduction in cv. Thori. Half and quarter dose of chemical fertilizers increased the shoot length of safflower whereas maximum increase in leaf protein was recorded in Azotobacter in combination with full dose of chemical fertilizers. Root length was improved by Azospirillum and Azotobacter in combination with quarter dose of chemical fertilizers. Leaf area and chlorophyll contents were significantly improved by Azotobacter in combination with half dose of chemical fertilizers. It is inferred that PGPR can supplement 50 % chemical fertilizers for better plant growth and soil health. (author)

Radiation hormesis in plant

International Nuclear Information System (INIS)

Kim, Jae Sung; Lee, Young Keun; Lee, Sang Jae and others; Park, Youn Il; Kwon, Soon Tae

2003-05-01

This research was performed to investigate the effects of low dose gamma radiation on germination, early growth and yield in a wide range of vegetable crops. The stimulating effects of gamma radiation was evaluated through investigating germination rate, early growth and physiological activities such as enzyme activities, hormones and photosynthetic responses etc. Induction of increased shikonin production in the plants by low dose gamma radiation was challenged to open up the possibility of applying radiation hormesis to the industrial mass production system of the natural materials useful to humans. Effects of natural radiation emitted from solid ceramics was compared on the plants with those of low dose gamma radiation. Finally, activation of aged seeds by low dose gamma radiation, probably facilitating their commercial circulation in the agriculture, was challenged in association with an industrial seed company. Moreover, the shift in resistance of the crops to environmental stresses including UV and low temperature was addressed as well as DNA damage, repair and protein expression after gamma irradiation

Enzyme stabilization for pesticide degradation

Energy Technology Data Exchange (ETDEWEB)

Rivers, D.B.; Frazer, F.R. III; Mason, D.W.; Tice, T.R.

1988-01-01

Enzymes offer inherent advantages and limitations as active components of formulations used to decontaminate soil and equipment contaminated with toxic materials such as pesticides. Because of the catalytic nature of enzymes, each molecule of enzyme has the potential to destroy countless molecules of a contaminating toxic compound. This degradation takes place under mild environmental conditions of pH, temperature, pressure, and solvent. The basic limitation of enzymes is their degree of stability during storage and application conditions. Stabilizing methods such as the use of additives, covalent crosslinking, covalent attachment, gel entrapment, and microencapsulation have been directed developing an enzyme preparation that is stable under extremes of pH, temperature, and exposure to organic solvents. Initial studies were conducted using the model enzymes subtilisin and horseradish peroxidase.

Levels of natural radionuclides in soil samples around a phosphate fertilizer plant

International Nuclear Information System (INIS)

Ajmal, P.Y.; Sahu, S.K.; Bhangare, R.C.; Pandit, G.G.; Puranik, V.D.

2010-01-01

The present study is aimed at the determination of the activity levels of primordial radionuclides in soil from various locations around a phosphate fertilizer plant and also to figure out the external dose rate due to natural gamma background in the area by mapping the dose rates with the geographical co-ordinates within the plant premises

Cadmium phytotoxicity: Quantitative sensitivity relationships between classical endpoints and antioxidative enzyme biomarkers

Energy Technology Data Exchange (ETDEWEB)

Rosa Correa, Albertina Xavier da [Centro de Ciencias Tecnologicas da Terra e do Mar, Universidade do Vale do Itajai, Rua Uruguai, 458, 88302-202 Itajai SC (Brazil); Roerig, Leonardo Rubi [Centro de Ciencias Tecnologicas da Terra e do Mar, Universidade do Vale do Itajai, Rua Uruguai, 458, 88302-202 Itajai SC (Brazil); Verdinelli, Miguel A. [Centro de Ciencias Tecnologicas da Terra e do Mar, Universidade do Vale do Itajai, Rua Uruguai, 458, 88302-202 Itajai SC (Brazil); Cotelle, Sylvie [Centre des Sciences de l' Environnement, Universite de Metz, 57000 Metz (France); Ferard, Jean-Francois [Centre des Sciences de l' Environnement, Universite de Metz, 57000 Metz (France); Radetski, Claudemir Marcos [Centro de Ciencias Tecnologicas da Terra e do Mar, Universidade do Vale do Itajai, Rua Uruguai, 458, 88302-202 Itajai SC (Brazil)]. E-mail: radetski@univali.br

2006-03-15

In this work, cadmium phytotoxicity and quantitative sensitivity relationships between different hierarchical endpoints in plants cultivated in a contaminated soil were studied. Thus, germination rate, biomass growth and antioxidative enzyme activity (i.e. superoxide dismutase, peroxidase, catalase and glutathione reductase) in three terrestrial plants (Avena sativa L., Brassica campestris L. cv. Chinensis, Lactuca sativa L. cv. hanson) were analyzed. Plant growth tests were carried out according to an International Standard Organization method and the results were analyzed by ANOVA followed by Williams' test. The concentration of Cd{sup 2+} that had the smallest observed significant negative effect (LOEC) on plant biomass was 6.25, 12.5 and 50 mg Cd/kg dry soil for lettuce, oat and Chinese cabbage, respectively. Activity of all enzymes studied increased significantly compared to enzyme activity in plant controls. For lettuce, LOEC values (mg Cd/kg dry soil) for enzymic activity ranged from 0.05 (glutathione reductase) to 0.39 (catalase). For oat, LOEC values (mg Cd/kg dry soil) ranged from 0.19 (for superoxide dismutase and glutathione reductase) to 0.39 (for catalase and peroxidase). For Chinese cabbage, LOEC values (mg Cd/kg dry soil) ranged from 0.19 (peroxidase, catalase and glutathione reductase) to 0.39 (superoxide dismutase). Classical (i.e. germination and biomass) and biochemical (i.e. enzyme activity) endpoints were compared to establish a sensitivity ranking, which was: enzyme activity > biomass > germination rate. For cadmium-soil contamination, the determination of quantitative sensitivity relationships (QSR) between classical and antioxidative enzyme biomarkers showed that the most sensitive plant species have, generally, the lowest QSR values.

Genetic variation in plant volatile emission does not result in differential attraction of natural enemies in the field.

Science.gov (United States)

Wason, Elizabeth L; Hunter, Mark D

2014-02-01

Volatile organic chemical (VOC) emission by plants may serve as an adaptive plant defense by attracting the natural enemies of herbivores. For plant VOC emission to evolve as an adaptive defense, plants must show genetic variability for the trait. To date, such variability has been investigated primarily in agricultural systems, yet relatively little is known about genetic variation in VOCs emitted by natural populations of native plants. Here, we investigate intraspecific variation in constitutive and herbivore-induced plant VOC emission using the native common milkweed plant (Asclepias syriaca) and its monarch caterpillar herbivore (Danaus plexippus) in complementary field and common garden greenhouse experiments. In addition, we used a common garden field experiment to gauge natural enemy attraction to milkweed VOCs induced by monarch damage. We found evidence of genetic variation in the total constitutive and induced concentrations of VOCs and the composition of VOC blends emitted by milkweed plants. However, all milkweed genotypes responded similarly to induction by monarchs in terms of their relative change in VOC concentration and blend. Natural enemies attacked decoy caterpillars more frequently on damaged than on undamaged milkweed, and natural enemy visitation was associated with higher total VOC concentrations and with VOC blend. Thus, we present evidence that induced VOCs emitted by milkweed may function as a defense against herbivores. However, plant genotypes were equally attractive to natural enemies. Although milkweed genotypes diverge phenotypically in their VOC concentrations and blends, they converge into similar phenotypes with regard to magnitude of induction and enemy attraction.

Plants as Natural Dyes for Jonegoroan Batik Processing in Jono Cultural Tourism Village, Bojonegoro, East Java

Directory of Open Access Journals (Sweden)

Nurizza Fauziyah

2015-05-01

Full Text Available Batik Jonegoroan is one of the potential tourism product in Jono Village, Bojonegoro. Batik was processed by traditional procedure using natural dyes from plants. In order to preserve the traditional batik which was colored by natural dyes from plant, the preservation of such plant were important. As far, there are no scientific data related to the species usage in Batik production. The aims of the research were identifying plant which were used as natural dyes in Batik processing. Data were collected ​​through observation, and  semi-structured interviews to batik craftsmen. Results of interviews were analyzed descriptively. The importance of plant was analyzed using Relative Frequency of Citation (RFC index. Based on the results, there are 12 plant species used as batik dye. It is consisted of Teak, Mahogany, Ketapang, Tamarind, Mangosteen, Mango, Suji, Pandan, Indigofera, Guava, Banana and Onion. Teak (Tectonagrandis L. and Mahogany (Swietenia mahogany L. have the highest value of RFC, 1.00. Both species were the most frequently cited species as sources of natural dyes. Extraction of Teak leaves produce red hearts and extraction of mahogany tree bark produces red-brown dye. Both of the color is the most important color in batik motifs. Keywords: batik Jonegoroan, Jono Cultural Tourism Village, perception, quality, RFC

Exploiting fine-scale genetic and physiological variation of closely related microbes to reveal unknown enzyme functions.

Science.gov (United States)

Badur, Ahmet H; Plutz, Matthew J; Yalamanchili, Geethika; Jagtap, Sujit Sadashiv; Schweder, Thomas; Unfried, Frank; Markert, Stephanie; Polz, Martin F; Hehemann, Jan-Hendrik; Rao, Christopher V

2017-08-04

Polysaccharide degradation by marine microbes represents one of the largest and most rapid heterotrophic transformations of organic matter in the environment. Microbes employ systems of complementary carbohydrate-specific enzymes to deconstruct algal or plant polysaccharides (glycans) into monosaccharides. Because of the high diversity of glycan substrates, the functions of these enzymes are often difficult to establish. One solution to this problem may lie within naturally occurring microdiversity; varying numbers of enzymes, due to gene loss, duplication, or transfer, among closely related environmental microbes create metabolic differences akin to those generated by knock-out strains engineered in the laboratory used to establish the functions of unknown genes. Inspired by this natural fine-scale microbial diversity, we show here that it can be used to develop hypotheses guiding biochemical experiments for establishing the role of these enzymes in nature. In this work, we investigated alginate degradation among closely related strains of the marine bacterium Vibrio splendidus One strain, V. splendidus 13B01, exhibited high extracellular alginate lyase activity compared with other V. splendidus strains. To identify the enzymes responsible for this high extracellular activity, we compared V. splendidus 13B01 with the previously characterized V. splendidus 12B01, which has low extracellular activity and lacks two alginate lyase genes present in V. splendidus 13B01. Using a combination of genomics, proteomics, biochemical, and functional screening, we identified a polysaccharide lyase family 7 enzyme that is unique to V. splendidus 13B01, secreted, and responsible for the rapid digestion of extracellular alginate. These results demonstrate the value of querying the enzymatic repertoires of closely related microbes to rapidly pinpoint key proteins with beneficial functions. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Natural products - plenty more where that came from

Energy Technology Data Exchange (ETDEWEB)

Arnold, M.

1980-12-22

In this article, natural products and their possible use as renewable resources are reviewed. The fermentation of corn for the production of alcohol for motor fuel is discussed and other crops for this purpose include sugar cane, cassava, sweet potato and Jerusalem artichoke. The hydrolysis of cellulose to sugars based on enzyme hydrolysis is currently being researched in the USA. Also in the USA, Melvin Calvin hopes to breed a rubber-bearing plant whose latex can be easily cracked to motor fuel. Guayule and jojoba rubber-bearing plants are also the focus of research at present. The importance of natural vegetation in the manufacturing of medicines and in the chemical and food industries is stressed. Finally products of the sea, particularly alginates and carragheenins are mentioned, but as yet, the full potential of the sea to yield renewable resources is unknown.

Engineering microbial cell factories for the production of plant natural products: from design principles to industrial-scale production.

Science.gov (United States)

Liu, Xiaonan; Ding, Wentao; Jiang, Huifeng

2017-07-19

Plant natural products (PNPs) are widely used as pharmaceuticals, nutraceuticals, seasonings, pigments, etc., with a huge commercial value on the global market. However, most of these PNPs are still being extracted from plants. A resource-conserving and environment-friendly synthesis route for PNPs that utilizes microbial cell factories has attracted increasing attention since the 1940s. However, at the present only a handful of PNPs are being produced by microbial cell factories at an industrial scale, and there are still many challenges in their large-scale application. One of the challenges is that most biosynthetic pathways of PNPs are still unknown, which largely limits the number of candidate PNPs for heterologous microbial production. Another challenge is that the metabolic fluxes toward the target products in microbial hosts are often hindered by poor precursor supply, low catalytic activity of enzymes and obstructed product transport. Consequently, despite intensive studies on the metabolic engineering of microbial hosts, the fermentation costs of most heterologously produced PNPs are still too high for industrial-scale production. In this paper, we review several aspects of PNP production in microbial cell factories, including important design principles and recent progress in pathway mining and metabolic engineering. In addition, implemented cases of industrial-scale production of PNPs in microbial cell factories are also highlighted.

Sterol glycosyltransferases--the enzymes that modify sterols.

Science.gov (United States)

Chaturvedi, Pankaj; Misra, Pratibha; Tuli, Rakesh

2011-09-01

Sterols are important components of cell membranes, hormones, signalling molecules and defense-related biotic and abiotic chemicals. Sterol glycosyltransferases (SGTs) are enzymes involved in sterol modifications and play an important role in metabolic plasticity during adaptive responses. The enzymes are classified as a subset of family 1 glycosyltransferases due to the presence of a signature motif in their primary sequence. These enzymes follow a compulsory order sequential mechanism forming a ternary complex. The diverse applications of sterol glycosides, like cytotoxic and apoptotic activity, anticancer activity, medicinal values, anti-stress roles and anti-insect and antibacterial properties, draws attention towards their synthesis mechanisms. Many secondary metabolites are derived from sterol pathways, which are important in defense mechanisms against pathogens. SGTs in plants are involved in changed sensitivity to stress hormones and their agrochemical analogs and changed tolerance to biotic and abiotic stresses. SGTs that glycosylate steroidal hormones, such as brassinosteroids, function as growth and development regulators in plants. In terms of metabolic roles, it can be said that SGTs occupy important position in plant metabolism and may offer future tools for crop improvement.

Sequestration of plant secondary metabolites by insect herbivores: molecular mechanisms and ecological consequences.

Science.gov (United States)

Erb, Matthias; Robert, Christelle Am

2016-04-01

Numerous insect herbivores can take up and store plant toxins as self-defense against their own natural enemies. Plant toxin sequestration is tightly linked with tolerance strategies that keep the toxins functional. Specific transporters have been identified that likely allow the herbivore to control the spatiotemporal dynamics of toxin accumulation. Certain herbivores furthermore possess specific enzymes to boost the bioactivity of the sequestered toxins. Ecologists have studied plant toxin sequestration for decades. The recently uncovered molecular mechanisms in combination with transient, non-transgenic systems to manipulate insect gene expression will help to understand the importance of toxin sequestration for food-web dynamics in nature. Copyright © 2015 Elsevier Inc. All rights reserved.

Standard model for safety analysis report of hexafluoride power plants from natural uranium

International Nuclear Information System (INIS)

1983-01-01

The standard model for safety analysis report for hexafluoride production power plants from natural uranium is presented, showing the presentation form, the nature and the degree of detail, of the minimal information required by the Brazilian Nuclear Energy Commission - CNEN. (E.G.) [pt

Applications of Microbial Enzymes in Food Industry

Directory of Open Access Journals (Sweden)

Binod Parameswaran

2018-01-01

Full Text Available The use of enzymes or microorganisms in food preparations is an age-old process. With the advancement of technology, novel enzymes with wide range of applications and specificity have been developed and new application areas are still being explored. Microorganisms such as bacteria, yeast and fungi and their enzymes are widely used in several food preparations for improving the taste and texture and they offer huge economic benefits to industries. Microbial enzymes are the preferred source to plants or animals due to several advantages such as easy, cost-effective and consistent production. The present review discusses the recent advancement in enzyme technology for food industries. A comprehensive list of enzymes used in food processing, the microbial source of these enzymes and the wide range of their application are discussed.

Induction of antioxidant enzyme activity and lipid peroxidation level in ion-beam-bombarded rice seeds

Energy Technology Data Exchange (ETDEWEB)

Semsang, Nuananong, E-mail: nsemsang@gmail.com [Molecular Biology Laboratory, Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Yu, LiangDeng [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand)

2013-07-15

Highlights: ► Ion beam bombarded rice seeds in vacuum. ► Studied seed survival from the ion bombardment. ► Determined various antioxidant enzyme activities and lipid peroxidation level. ► Discussed vacuum, ion species and ion energy effects. ► Attributed the changes to free radical formation due to ion bombardment. -- Abstract: Low-energy ion beam bombardment has been used to mutate a wide variety of plant species. To explore the indirect effects of low-energy ion beam on biological damage due to the free radical production in plant cells, the increase in antioxidant enzyme activities and lipid peroxidation level was investigated in ion-bombarded rice seeds. Local rice seeds were bombarded with nitrogen or argon ion beams at energies of 29–60 keV and ion fluences of 1 × 10{sup 16} ions cm{sup −2}. The activities of the antioxidant enzymes; superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR), glutathione reductase (GR), glutathione S-transferase (GST) and lipid peroxidation level were assayed in the germinated rice seeds after ion bombardment. The results showed most of the enzyme activities and lipid peroxidation levels in both the argon and nitrogen bombarded samples were higher than those in the natural control. N-ion bombardment could induce higher levels of antioxidant enzyme activities in the rice samples than the Ar-ion bombardment. Additional effects due to the vacuum condition were found to affect activities of some antioxidant enzymes and lipid peroxidation level. This study demonstrates that ion beam bombardment and vacuum condition could induce the antioxidant enzyme activity and lipid peroxidation level which might be due to free radical production in the bombarded rice seeds.

Reduced Dental Plaque Formation in Dogs Drinking a Solution Containing Natural Antimicrobial Herbal Enzymes and Organic Matcha Green Tea

Directory of Open Access Journals (Sweden)

Michael I. Lindinger

2016-01-01

Full Text Available The results of an exploratory, multicenter clinical study confirmed the hypothesis that a novel, natural, and safe oral care product (OCP reduced the rate of plaque formation on teeth of dogs consuming the OCP (antimicrobial plant-derived enzymes, organic matcha green tea, cultured dextrose, sodium bicarbonate, and ascorbic acid compared to controls. Healthy dogs without periodontitis, of varying breeds, sex, and age, were recruited and enrolled, using nonrandomized stratification methods, into a control and treatment groups. Treatment group dogs drank only water into which OCP was suspended, for 28 days. Control group dogs drank their normal household water. On day 0 all teeth were cleaned by a veterinarian and gingivitis was assessed. On days 14, 21, and 28 plaque index, plaque thickness, gingivitis, freshness of breath, and general health were assessed. Over the 28 days of study, dogs on the OCP had significant reduction in plaque index and plaque thickness compared to controls. By day 14 OCP reduced plaque formation by 37%; the 28-day reduction in plaque index and coverage averaged 22% with no measurable gingivitis or calculus. Conclusion. Using the OCP attenuated dental plaque formation when consumed as normal drinking water and in the absence of other modes of oral care.

Enzymes are a sweet way to do business

Energy Technology Data Exchange (ETDEWEB)

1980-01-04

The use of enzymes in industry is growing steadily. This artic discusses some areas of enzyme research: included are enzyme treatments for the production of high-fructose corn syrup and ethanol for gasohol blends, enzyme research focusing on cellulose breakdown, especially from municipal waste and pulp and paper waste to produce ethanol and the conversion of soybeans into a protein-rich powder. The enzymatic process for nitrogen fixation in the nodules of certain leguminous plants and in medical diagnostics are also mentioned.

Enzymes in Fermented Fish.

Science.gov (United States)

Giyatmi; Irianto, H E

Fermented fish products are very popular particularly in Southeast Asian countries. These products have unique characteristics, especially in terms of aroma, flavor, and texture developing during fermentation process. Proteolytic enzymes have a main role in hydrolyzing protein into simpler compounds. Fermentation process of fish relies both on naturally occurring enzymes (in the muscle or the intestinal tract) as well as bacteria. Fermented fish products processed using the whole fish show a different characteristic compared to those prepared from headed and gutted fish. Endogenous enzymes like trypsin, chymotrypsin, elastase, and aminopeptidase are the most involved in the fermentation process. Muscle tissue enzymes like cathepsins, peptidases, transaminases, amidases, amino acid decarboxylases, glutamic dehydrogenases, and related enzymes may also play a role in fish fermentation. Due to the decreased bacterial number during fermentation, contribution of microbial enzymes to proteolysis may be expected prior to salting of fish. Commercial enzymes are supplemented during processing for specific purposes, such as quality improvement and process acceleration. In the case of fish sauce, efforts to accelerate fermentation process and to improve product quality have been studied by addition of enzymes such as papain, bromelain, trypsin, pepsin, and chymotrypsin. © 2017 Elsevier Inc. All rights reserved.

Robust Control of PEP Formation Rate in the Carbon Fixation Pathway of C4 Plants by a Bi-functional Enzyme

Directory of Open Access Journals (Sweden)

Hart Yuval

2011-10-01

Full Text Available Abstract Background C4 plants such as corn and sugarcane assimilate atmospheric CO2 into biomass by means of the C4 carbon fixation pathway. We asked how PEP formation rate, a key step in the carbon fixation pathway, might work at a precise rate, regulated by light, despite fluctuations in substrate and enzyme levels constituting and regulating this process. Results We present a putative mechanism for robustness in C4 carbon fixation, involving a key enzyme in the pathway, pyruvate orthophosphate dikinase (PPDK, which is regulated by a bifunctional enzyme, Regulatory Protein (RP. The robust mechanism is based on avidity of the bifunctional enzyme RP to its multimeric substrate PPDK, and on a product-inhibition feedback loop that couples the system output to the activity of the bifunctional regulator. The model provides an explanation for several unusual biochemical characteristics of the system and predicts that the system's output, phosphoenolpyruvate (PEP formation rate, is insensitive to fluctuations in enzyme levels (PPDK and RP, substrate levels (ATP and pyruvate and the catalytic rate of PPDK, while remaining sensitive to the system's input (light levels. Conclusions The presented PPDK mechanism is a new way to achieve robustness using product inhibition as a feedback loop on a bifunctional regulatory enzyme. This mechanism exhibits robustness to protein and metabolite levels as well as to catalytic rate changes. At the same time, the output of the system remains tuned to input levels.

Epigenetic variation in mangrove plants occurring in contrasting natural environment.

Directory of Open Access Journals (Sweden)

Catarina Fonseca Lira-Medeiros

2010-04-01

Full Text Available Epigenetic modifications, such as cytosine methylation, are inherited in plant species and may occur in response to biotic or abiotic stress, affecting gene expression without changing genome sequence. Laguncularia racemosa, a mangrove species, occurs in naturally contrasting habitats where it is subjected daily to salinity and nutrient variations leading to morphological differences. This work aims at unraveling how CpG-methylation variation is distributed among individuals from two nearby habitats, at a riverside (RS or near a salt marsh (SM, with different environmental pressures and how this variation is correlated with the observed morphological variation.Significant differences were observed in morphological traits such as tree height, tree diameter, leaf width and leaf area between plants from RS and SM locations, resulting in smaller plants and smaller leaf size in SM plants. Methyl-Sensitive Amplified Polymorphism (MSAP was used to assess genetic and epigenetic (CpG-methylation variation in L. racemosa genomes from these populations. SM plants were hypomethylated (14.6% of loci had methylated samples in comparison to RS (32.1% of loci had methylated samples. Within-population diversity was significantly greater for epigenetic than genetic data in both locations, but SM also had less epigenetic diversity than RS. Frequency-based (G(ST and multivariate (beta(ST methods that estimate population structure showed significantly greater differentiation among locations for epigenetic than genetic data. Co-Inertia analysis, exploring jointly the genetic and epigenetic data, showed that individuals with similar genetic profiles presented divergent epigenetic profiles that were characteristic of the population in a particular environment, suggesting that CpG-methylation changes may be associated with environmental heterogeneity.In spite of significant morphological dissimilarities, individuals of L. racemosa from salt marsh and riverside presented

Genetic variability in chronic irradiated plant populations - Polymorphism and activity of antioxidant enzymes in chronic irradiated plant populations

Energy Technology Data Exchange (ETDEWEB)

Volkova, Polina Y.; Geras' kin, Stanislav A. [Russian Institute of Agricultural Radiology and Agroecology, 249030, Obninsk, Kievskoe shosse 109 km (Russian Federation)

2014-07-01

Introduction: The gene pool of natural population is constantly changing in order to provide the greatest fitness at this time. Ability of population to adapt to changing environmental conditions depends on genetic polymorphism of traits which are operates by selection. Chronic stress exposure can change amount or structure intra-population variability. Therefore, it is necessary to analyze the relationships between genetic polymorphism and stress factors, such as radiation exposure. This studies my assist in the development of new bio-indication methods. Materials and methods: Studying sites: Bryansk region is the most contaminated region of Russia as a result of Chernobyl accident. The initial activity by {sup 137}Cs on this territory reached 1 MBq/m{sup 2} above surface. Our study conducted in several districts of Bryansk region, which are characterized the most dose rate. Experimental sites similar to climate characteristics, stand of trees is homogeneous, pine trees take up a significant part of phytocenosis. Heavy metals content in soils and cones be within background. Dose rates vary from 0.14 to 130 mGy/year. Object: Pinus sylvestris L.,the dominant tree species in North European and Asian boreal forests. Scots pine has a long maturation period (18-20 month), which means that significant DNA damage may accumulate in the undifferentiated stem cells, even at low doses (or dose rates) during exposure to low concentrations of contaminants Isozyme analysis: We evaluated isozyme polymorphism of three antioxidant enzymes: superoxide dismutase, glutatione reductase and glutatione peroxidase. Analysis of enzymes activities: We chose key enzymes of antioxidant system for this experiment: superoxide dismutase, catalase and peroxidase. Results and conclusions: We estimated frequency of each allele in reference and experimental populations. based It was showed that frequency of rare alleles increase in chronic irradiated populations, i.e. increase the sampling variance

Development and design of plants for high-pressure extraction of natural products

Energy Technology Data Exchange (ETDEWEB)

Eggers, R; Tschiersch, R [Thyssen Industrie A.G., Witten (Germany, F.R.)

1979-06-01

Criteria underlying the design of plant for recovery of carrier material or extract are reviewed, particularly in relation to the extraction of natural products with supercritical CO/sub 2/. The parameters to be determined in the planning of a large-scale plant are outlined and as an example of a typical process, the extraction of spices is discussed in detail. The plant components and equipment are presented together with their particular process and construction characteristics. Finally, the thermodynamic aspects are analyzed and methods of optimizing a large-scale plant and of reducing the power consumption are outlined. Particular attention is paid to the question of optimization with regard to the most economic method of operation of such a plant to be applied in the future.

Bacteria Associated to Plants Naturally Selected in a Historical PCB Polluted Soil Show Potential to Sustain Natural Attenuation

KAUST Repository

Vergani, Lorenzo; Mapelli, Francesca; Marasco, Ramona; Crotti, Elena; Fusi, Marco; Di Guardo, Antonio; Armiraglio, Stefano; Daffonchio, Daniele; Borin, Sara

2017-01-01

The exploitation of the association between plants and microorganisms is a promising approach able to boost natural attenuation processes for soil clean-up in vast polluted areas characterized by mixed chemical contamination. We aimed to explore

Expression, purification, crystallization and preliminary X-ray analysis of perakine reductase, a new member of the aldo-keto reductase enzyme superfamily from higher plants

Science.gov (United States)

Rosenthal, Cindy; Mueller, Uwe; Panjikar, Santosh; Sun, Lianli; Ruppert, Martin; Zhao, Yu; Stöckigt, Joachim

2006-01-01

Perakine reductase (PR) is a novel member of the aldo-keto reductase enzyme superfamily from higher plants. PR from the plant Rauvolfia serpentina is involved in the biosynthesis of monoterpenoid indole alkaloids by performing NADPH-dependent reduction of perakine, yielding raucaffrinoline. However, PR can also reduce cinnamic aldehyde and some of its derivatives. After heterologous expression of a triple mutant of PR in Escherichia coli, crystals of the purified and methylated enzyme were obtained by the hanging-drop vapour-diffusion technique at 293 K with 100 mM sodium citrate pH 5.6 and 27% PEG 4000 as precipitant. Crystals belong to space group C2221 and diffract to 2.0 Å, with unit-cell parameters a = 58.9, b = 93.0, c = 143.4 Å. PMID:17142919

Investigation of Natural Radioactivity in a Monazite Processing Plant in Japan.

Science.gov (United States)

Iwaoka, Kazuki; Yajima, Kazuaki; Suzuki, Toshikazu; Yonehara, Hidenori; Hosoda, Masahiro; Tokonami, Shinji; Kanda, Reiko

2017-09-01

Monazite is a naturally occurring radioactive material that is processed for use in a variety of domestic applications. At present, there is little information available on potential radiation doses experienced by people working with monazite. The ambient dose rate and activity concentration of natural radionuclides in raw materials, products, and dust in work sites as well as the Rn and Rn concentrations in work sites were measured in a monazite processing plant in Japan. Dose estimations for plant workers were also conducted. The activity concentration of the U series in raw materials and products for the monazite processing plant was found to be higher than the relevant values described in the International Atomic Energy Agency Safety Standards. The ambient dose rates in the raw material yard were higher than those in other work sites. Moreover, the activity concentrations of dust in the milling site were higher than those in other work sites. The Rn concentrations in all work sites were almost the same as those in regular indoor environments in Japan. The Rn concentrations in all work sites were much higher than those in regular indoor environments in Japan. The maximum value of the effective dose for workers was 0.62 mSv y, which is lower than the reference level range (1-20 mSv y) for abnormally high levels of natural background radiation published in the International Commission of Radiological Protection Publication 103.

Beyond theories of plant invasions: Lessons from natural landscapes

Science.gov (United States)

Stohlgren, Thomas J.

2002-01-01

There are a growing number of contrasting theories about plant invasions, but most are only weakly supported by small-scale field experiments, observational studies, and mathematical models. Among the most contentious theories is that species-rich habitats should be less vulnerable to plant invasion than species-poor sites, stemming from earlier theories that competition is a major force in structuring plant communities. Early ecologists such as Charles Darwin (1859) and Charles Elton (1958) suggested that a lack of intense interspecific competition on islands made these low-diversity habitats vulnerable to invasion. Small-scale field experiments have supported and contradicted this theory, as have various mathematical models. In contrast, many large-scale observational studies and detailed vegetation surveys in continental areas often report that species-rich areas are more heavily invaded than species-poor areas, but there are exceptions here as well. In this article, I show how these seemingly contrasting patterns converge once appropriate spatial and temporal scales are considered in complex natural environments. I suggest ways in which small-scale experiments, mathematical models, and large- scale observational studies can be improved and better integrated to advance a theoretically based understanding of plant invasions.

Massive lateral transfer of genes encoding plant cell wall-degrading enzymes to the mycoparasitic fungus Trichoderma from its plant-associated hosts

Science.gov (United States)

Chenthamara, Komal; Zhang, Jian; Atanasova, Lea; Yang, Dongqing; Miao, Youzhi; Grujic, Marica; Pourmehdi, Shadi; Pretzer, Carina; Kopchinskiy, Alexey G.; Hundley, Hope; Wang, Mei; Aerts, Andrea; Salamov, Asaf; Lipzen, Anna; Barry, Kerrie; Grigoriev, Igor V.; Shen, Qirong; Kubicek, Christian P.

2018-01-01

Unlike most other fungi, molds of the genus Trichoderma (Hypocreales, Ascomycota) are aggressive parasites of other fungi and efficient decomposers of plant biomass. Although nutritional shifts are common among hypocrealean fungi, there are no examples of such broad substrate versatility as that observed in Trichoderma. A phylogenomic analysis of 23 hypocrealean fungi (including nine Trichoderma spp. and the related Escovopsis weberi) revealed that the genus Trichoderma has evolved from an ancestor with limited cellulolytic capability that fed on either fungi or arthropods. The evolutionary analysis of Trichoderma genes encoding plant cell wall-degrading carbohydrate-active enzymes and auxiliary proteins (pcwdCAZome, 122 gene families) based on a gene tree / species tree reconciliation demonstrated that the formation of the genus was accompanied by an unprecedented extent of lateral gene transfer (LGT). Nearly one-half of the genes in Trichoderma pcwdCAZome (41%) were obtained via LGT from plant-associated filamentous fungi belonging to different classes of Ascomycota, while no LGT was observed from other potential donors. In addition to the ability to feed on unrelated fungi (such as Basidiomycota), we also showed that Trichoderma is capable of endoparasitism on a broad range of Ascomycota, including extant LGT donors. This phenomenon was not observed in E. weberi and rarely in other mycoparasitic hypocrealean fungi. Thus, our study suggests that LGT is linked to the ability of Trichoderma to parasitize taxonomically related fungi (up to adelphoparasitism in strict sense). This may have allowed primarily mycotrophic Trichoderma fungi to evolve into decomposers of plant biomass. PMID:29630596

Multi-Target Screening and Experimental Validation of Natural Products from Selaginella Plants against Alzheimer's Disease

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Yin-Hua Deng

2017-08-01

Full Text Available Alzheimer's disease (AD is a progressive and irreversible neurodegenerative disorder which is considered to be the most common cause of dementia. It has a greater impact not only on the learning and memory disturbances but also on social and economy. Currently, there are mainly single-target drugs for AD treatment but the complexity and multiple etiologies of AD make them difficult to obtain desirable therapeutic effects. Therefore, the choice of multi-target drugs will be a potential effective strategy inAD treatment. To find multi-target active ingredients for AD treatment from Selaginella plants, we firstly explored the behaviors effects on AD mice of total extracts (TE from Selaginella doederleinii on by Morris water maze test and found that TE has a remarkable improvement on learning and memory function for AD mice. And then, multi-target SAR models associated with AD-related proteins were built based on Random Forest (RF and different descriptors to preliminarily screen potential active ingredients from Selaginella. Considering the prediction outputs and the quantity of existing compounds in our laboratory, 13 compounds were chosen to carry out the in vitro enzyme inhibitory experiments and 4 compounds with BACE1/MAO-B dual inhibitory activity were determined. Finally, the molecular docking was applied to verify the prediction results and enzyme inhibitory experiments. Based on these study and validation processes, we explored a new strategy to improve the efficiency of active ingredients screening based on trace amount of natural product and numbers of targets and found some multi-target compounds with biological activity for the development of novel drugs for AD treatment.

Contemporary enzyme based technologies for bioremediation: A review.

Science.gov (United States)

Sharma, Babita; Dangi, Arun Kumar; Shukla, Pratyoosh

2018-03-15

The persistent disposal of xenobiotic compounds like insecticides, pesticides, fertilizers, plastics and other hydrocarbon containing substances is the major source of environmental pollution which needs to be eliminated. Many contemporary remediation methods such as physical, chemical and biological are currently being used, but they are not sufficient to clean the environment. The enzyme based bioremediation is an easy, quick, eco-friendly and socially acceptable approach used for the bioremediation of these recalcitrant xenobiotic compounds from the natural environment. Several microbial enzymes with bioremediation capability have been isolated and characterized from different natural sources, but less production of such enzymes is a limiting their further exploitation. The genetic engineering approach has the potential to get large amount of recombinant enzymes. Along with this, enzyme immobilization techniques can boost the half-life, stability and activity of enzymes at a significant level. Recently, nanozymes may offer the potential bioremediation ability towards a broad range of pollutants. In the present review, we have described a brief overview of the microbial enzymes, different enzymes techniques (genetic engineering and immobilization of enzymes) and nanozymes involved in bioremediation of toxic, carcinogenic and hazardous environmental pollutants. Copyright © 2018 Elsevier Ltd. All rights reserved.

Expanding the Halohydrin Dehalogenase Enzyme Family: Identification of Novel Enzymes by Database Mining.

Science.gov (United States)

Schallmey, Marcus; Koopmeiners, Julia; Wells, Elizabeth; Wardenga, Rainer; Schallmey, Anett

2014-12-01

Halohydrin dehalogenases are very rare enzymes that are naturally involved in the mineralization of halogenated xenobiotics. Due to their catalytic potential and promiscuity, many biocatalytic reactions have been described that have led to several interesting and industrially important applications. Nevertheless, only a few of these enzymes have been made available through recombinant techniques; hence, it is of general interest to expand the repertoire of these enzymes so as to enable novel biocatalytic applications. After the identification of specific sequence motifs, 37 novel enzyme sequences were readily identified in public sequence databases. All enzymes that could be heterologously expressed also catalyzed typical halohydrin dehalogenase reactions. Phylogenetic inference for enzymes of the halohydrin dehalogenase enzyme family confirmed that all enzymes form a distinct monophyletic clade within the short-chain dehydrogenase/reductase superfamily. In addition, the majority of novel enzymes are substantially different from previously known phylogenetic subtypes. Consequently, four additional phylogenetic subtypes were defined, greatly expanding the halohydrin dehalogenase enzyme family. We show that the enormous wealth of environmental and genome sequences present in public databases can be tapped for in silico identification of very rare but biotechnologically important biocatalysts. Our findings help to readily identify halohydrin dehalogenases in ever-growing sequence databases and, as a consequence, make even more members of this interesting enzyme family available to the scientific and industrial community. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Medicinal plants and natural products in amelioration of arsenic toxicity: a short review.

Science.gov (United States)

Bhattacharya, Sanjib

2017-12-01

Chronic arsenic toxicity (arsenicosis) is considered a serious public health menace worldwide, as there is no specific, safe, and efficacious therapeutic management of arsenicosis. To collate the studies on medicinal plants and natural products with arsenic toxicity ameliorative effect, active pre-clinically and/or clinically. Literature survey was carried out by using Google, Scholar Google and Pub-Med. Only the scientific journal articles found on the internet for last two decades were considered. Minerals and semi-synthetic or synthetic analogs of natural products were excluded. Literature study revealed that 34 medicinal plants and 14 natural products exhibited significant protection from arsenic toxicity, mostly in preclinical trials and a few in clinical studies. This research could lead to development of a potentially useful agent in clinical management of arsenicosis in humans.

High-level accumulation of oleyl oleate in plant seed oil by abundant supply of oleic acid substrates to efficient wax ester synthesis enzymes.

Science.gov (United States)

Yu, Dan; Hornung, Ellen; Iven, Tim; Feussner, Ivo

2018-01-01

Biotechnology enables the production of high-valued industrial feedstocks from plant seed oil. The plant-derived wax esters with long-chain monounsaturated acyl moieties, like oleyl oleate, have favorite properties for lubrication. For biosynthesis of wax esters using acyl-CoA substrates, expressions of a fatty acyl reductase (FAR) and a wax synthase (WS) in seeds are sufficient. For optimization of the enzymatic activity and subcellular localization of wax ester synthesis enzymes, two fusion proteins were created, which showed wax ester-forming activities in Saccharomyces cerevisiae . To promote the formation of oleyl oleate in seed oil, WSs from Acinetobactor baylyi ( Ab WSD1) and Marinobacter aquaeolei ( Ma WS2), as well as the two created fusion proteins were tested in Arabidopsis to evaluate their abilities and substrate preference for wax ester production. The tested seven enzyme combinations resulted in different yields and compositions of wax esters. Expression of a FAR of Marinobacter aquaeolei ( Ma FAR) with Ab WSD1 or Ma WS2 led to a high incorporation of C 18 substrates in wax esters. The Ma FAR/TM Mm AWAT2- Ab WSD1 combination resulted in the incorporation of more C 18:1 alcohol and C 18:0 acyl moieties into wax esters compared with Ma FAR/ Ab WSD1. The fusion protein of a WS from Simmondsia chinensis ( Sc WS) with MaFAR exhibited higher specificity toward C 20:1 substrates in preference to C 18:1 substrates. Expression of Ma FAR/ Ab WSD1 in the Arabidopsis fad2 fae1 double mutant resulted in the accumulation of oleyl oleate (18:1/18:1) in up to 62 mol% of total wax esters in seed oil, which was much higher than the 15 mol% reached by Ma FAR/ Ab WSD1 in Arabidopsis Col-0 background. In order to increase the level of oleyl oleate in seed oil of Camelina , lines expressing Ma FAR/ Sc WS were crossed with a transgenic high oleate line. The resulting plants accumulated up to >40 mg g seed -1 of wax esters, containing 27-34 mol% oleyl oleate. The

On the role of natural radiation background in the initial development of plants

International Nuclear Information System (INIS)

Kuzin, A.M.; Vagabova, M.Eh.; Primak-Mirolyubov, V.N.

1977-01-01

To obtain data on plant development under strictly controlled decreased natural radiation conditions, the experiment with radish seeds was conducted in a special chamber having a decreased natural radiation background. It has been shown that the development of seedlings in the course of the first 4-5 days in significantly delayed, and it normalizes when radiation sources, imitating the natural radiation background, are placed inside the chamber

Resolving the Role of Plant NAD-Glutamate Dehydrogenase: III. Overexpressing Individually or Simultaneously the Two Enzyme Subunits Under Salt Stress Induces Changes in the Leaf Metabolic Profile and Increases Plant Biomass Production.

Science.gov (United States)

Tercé-Laforgue, Thérèse; Clément, Gilles; Marchi, Laura; Restivo, Francesco M; Lea, Peter J; Hirel, Bertrand

2015-10-01

NAD-dependent glutamate dehydrogenase (NAD-GDH) of higher plants has a central position at the interface between carbon and nitrogen metabolism due to its ability to carry out the deamination of glutamate. In order to obtain a better understanding of the physiological function of NAD-GDH under salt stress conditions, transgenic tobacco (Nicotiana tabacum L.) plants that overexpress two genes from Nicotiana plumbaginifolia individually (GDHA and GDHB) or simultaneously (GDHA/B) were grown in the presence of 50 mM NaCl. In the different GDH overexpressors, the NaCl treatment induced an additional increase in GDH enzyme activity, indicating that a post-transcriptional mechanism regulates the final enzyme activity under salt stress conditions. A greater shoot and root biomass production was observed in the three types of GDH overexpressors following growth in 50 mM NaCl, when compared with the untransformed plants subjected to the same salinity stress. Changes in metabolites representative of the plant carbon and nitrogen status were also observed. They were mainly characterized by an increased amount of starch present in the leaves of the GDH overexpressors as compared with the wild type when plants were grown in 50 mM NaCl. Metabolomic analysis revealed that overexpressing the two genes GDHA and GDHB, individually or simultaneously, induced a differential accumulation of several carbon- and nitrogen-containing molecules involved in a variety of metabolic, developmental and stress-responsive processes. An accumulation of digalactosylglycerol, erythronate and porphyrin was found in the GDHA, GDHB and GDHA/B overexpressors, suggesting that these molecules could contribute to the improved performance of the transgenic plants under salinity stress conditions. © The Author 2015. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

PILOT PLANT STUDY ON NATURAL WATER COAGULANTS AS COAGULAN AIDS FOR WATER SUPPLY

Directory of Open Access Journals (Sweden)

B BINA

2001-06-01

Full Text Available Introduction: Natural plant coagulants have an important role to play in provision of portable water to rural communities in the developing world. The plant material that their coagulation properties have been confirmed in previous lab scale studies and can be found widely in Iran was selected as coagulant aids. Pilot plant study was done to evaluate the efficiency of natural material such as Starch/Gum Tragacanth, Fenugreek and Yeast as coagulant aids in conjunction with comercial alum. Methods: The pilot was placed in Isfahan Water Treatment Plant (IWTP and efficiency of these materials in removal of turbidity from raw water enters the IWTP was evaluated. The results indicated while these materials were used as coagulant aids in concentration of 1-5 mg/l conjunction with alum are able to reduced the turbidity and final residuals turbidity meets the standards limits. Results: The coagulation efficiency of these material were found to be effected by certain physico-chemical factors, namely, concentration of suspended solids, divalent cation metal and time of agitation. The relative importance of these variable was evaluated. The results of COD test proved that the natural coagulant aids in the optimum doses produce no any significant organic residual. Discussion: Economical considerations showed that using of these material as coagulant aids can cause reduction in alum consumption and in some cases are more econmical than synthetic polyelectrolyte.

Life Cycle Assessment of Producing Electricity in Thailand: A Case Study of Natural Gas Power Plant

Directory of Open Access Journals (Sweden)

Usapein Parnuwat

2017-01-01

Full Text Available Environmental impacts from natural gas power plant in Thailand was investigated in this study. The objective was to identify the hotspot of environmental impact from electricity production and the allocation of emissions from power plant was studied. All stressors to environment were collected for annual natural gas power plant operation. The allocation of environmental load between electricity and steam was done by WRI/WBCSD method. Based on the annual power plant operation, the highest of environmental impact was fuel combustion, followed by natural gas extraction, and chemical reagent. After allocation, the result found that 1 kWh of electricity generated 0.425 kgCO2eq and 1 ton of steam generated 225 kgCO2eq. When compared based on 1GJ of energy product, the result showed that the environmental impact of electricity is higher than steam product. To improve the environmental performance, it should be focused on the fuel combustion, for example, increasing the efficiency of gas turbine, and using low sulphur content of natural gas. This result can be used as guideline for stakeholder who engage with the environmental impact from power plant; furthermore, it can be useful for policy maker to understand the allocation method between electricity and steam products.

Drying and purification of natural gas by clinoptilolite on an experimental pilot plant

Energy Technology Data Exchange (ETDEWEB)

Tsitsishvili, G V; Urotadze, S L; Lukin, V D; Bagirov, R M

1976-02-01

The paper deals with the process of the drying and purification of natural gas from CO/sub 2/ on an experimental pilot plant using the natural zeolite clinoptilolite. On the basis of the obtained data the dynamic activity of clinoptilolite against water and CO/sub 2/ has been calculated.

Thermoelectric power plant selection using natural gas and sugar cane bagasse; Selecao de centrais termoeletricas utilizando gas natural e bagaco de cana

Energy Technology Data Exchange (ETDEWEB)

Leite, Caio de Paula [UNIFei - Faculdade de Engenharia Industrial, Sao Bernardo do Campo, SP (Brazil). Dept. de Engenharia Mecanica]. E-mail: cleite@edu.fei.br; Tribess, Arlindo [Sao Paulo Univ., SP (Brazil). Escola Politecnica. Dept. de Engenharia Mecanica]. E-mail: atribess@usp.br

2003-07-01

The electric power consumption in Brazil is growing about 4.2% a year, according to ELETROBRAS Decenal Plan in 1999. The capacity of installed electrical power is approximately 50000 MW, of the which 75% are in the Southern, South eastern and Middle western regions of the country. The growth rate indicates the need of an increase of the installed capacity of 2100 MW a year to avoid the risk of the lack of energy. On the other hand, the hydraulic potential sources of the region are practically exhausted and the government budget is low for this kind of investment. Therefore the solution would be the construction of new thermoelectric plants, with the possibility using natural gas and cane bagasse. The present work consists of the evaluation of the best option considering criterion of minimum cost for kWh of energy produced for the thermo electrical plants selection. Thermo economic analysis was made evaluating the production costs of steam and electricity in exergetic basis. The results show that the power cycles and cogeneration plants that use natural gas and cane bagasse are much more economical than the ones that just use natural gas, with 48% reduction of steam cost, 40% reduction of electricity cost generated b the steam turbine in the power cycle and 37% reduction of electricity cost generated by the steam turbine in the cogeneration plant, for cane bagasse price at 4 US$ /t and natural gas price at 140 US$/t. (author)

Natural gums of plant origin as edible coatings for food industry applications.

Science.gov (United States)

Saha, Anuradha; Tyagi, Shvetambri; Gupta, Rajinder K; Tyagi, Yogesh K

2017-12-01

Natural plant-based gums and their derivatives are widely utilized in food industries, however, their applications as edible coatings to extend fresh fruits and vegetable shelf-life has been explored recently. These natural polymeric polysaccharides have many advantages as compared to synthetic polymers, because they are biodegradable, nontoxic, economical and easily available in the environment. Natural gums can also be semi synthetically modified to produce derivatives, which can easily compete with the synthetic preservatives available on the food market. In this review, the recent developments in the use of natural gums and their derivatives as edible coatings have been explored and discussed.

Plant isoflavone and isoflavanone O-methyltransferase genes

Science.gov (United States)

Broeckling, Bettina E.; Liu, Chang-Jun; Dixon, Richard A.

2014-08-19

The invention provides enzymes that encode O-methyltransferases (OMTs) from Medicago truncatula that allow modification to plant (iso)flavonoid biosynthetic pathways. In certain aspects of the invention, the genes encoding these enzymes are provided. The invention therefore allows the modification of plants for isoflavonoid content. Transgenic plants comprising such enzymes are also provided, as well as methods for improving disease resistance in plants. Methods for producing food and nutraceuticals, and the resulting compositions, are also provided.

Antibacterial and glucosyltransferase enzyme inhibitory activity of helmyntostachyszelanica

Science.gov (United States)

Kuspradini, H.; Putri, AS; Mitsunaga, T.

2018-04-01

Helminthostachyszeylanica is a terrestrial, herbaceous, fern-like plant of southeastern Asia and Australia, commonly known as tunjuk-langit. This kind of plant have a medicinal properties such as treatment of malaria, dysentery and can be eaten with betel in the treatment of whooping cough. To evaluate the scientific basis for the use of the plant, the antimicrobial activities of extracts of the stem and leaves were evaluated. The bacteria used in this study is Streptococcus sobrinus, a species of gram-positive, that may be associated with human dental caries. The dried powdered plant parts were extracted using methanol and 50% aqueous extract and screened for their antibacterial effects of Streptococcus sobrinus using the 96 well-plate microdilution broth method. The inhibitory activities of its related enzyme were also determined. The plant extracts showed variable antibacterial and Glucosyltransferase enzyme inhibitory activity while some extracts could not cause any inhibition. It was shown that 50% ethanolics of Helminthostachyzeylanica stem have a potency as anti dental caries agents.

Finding and defining the natural automata acting in living plants: Toward the synthetic biology for robotics and informatics in vivo.

Science.gov (United States)

Kawano, Tomonori; Bouteau, François; Mancuso, Stefano

2012-11-01

The automata theory is the mathematical study of abstract machines commonly studied in the theoretical computer science and highly interdisciplinary fields that combine the natural sciences and the theoretical computer science. In the present review article, as the chemical and biological basis for natural computing or informatics, some plants, plant cells or plant-derived molecules involved in signaling are listed and classified as natural sequential machines (namely, the Mealy machines or Moore machines) or finite state automata. By defining the actions (states and transition functions) of these natural automata, the similarity between the computational data processing and plant decision-making processes became obvious. Finally, their putative roles as the parts for plant-based computing or robotic systems are discussed.

Enzyme Activities in Waste Water and Activated Sludge

DEFF Research Database (Denmark)

Nybroe, Ole; Jørgensen, Per Elberg; Henze, Mogens

1992-01-01

The purpose of the present study was to evaluate the potential of selected enzyme activity assays to determine microbial abundance and heterotrophic activity in waste water and activated sludge. In waste water, esterase and dehydrogenase activities were found to correlate with microbial abundance...... measured as colony forming units of heterotrophic bacteria. A panel of four enzyme activity assays, α-glucosidase, alanine-aminopeptidase, esterase and dehydrogenase were used to characterize activated sludge and anaerobic hydrolysis sludge from a pilot scale plant. The enzymatic activity profiles were...... distinctly different, suggesting that microbial populations were different, or had different physiological properties, in the two types of sludge. Enzyme activity profiles in activated sludge from four full-scale plants seemed to be highly influenced by the composition of the inlet. Addition of hydrolysed...

Granivory of invasive, naturalized, and native plants in communities differentially susceptible to invasion.

Science.gov (United States)

Connolly, B M; Pearson, D E; Mack, R N

2014-07-01

Seed predation is an important biotic filter that can influence abundance and spatial distributions of native species through differential effects on recruitment. This filter may also influence the relative abundance of nonnative plants within habitats and the communities' susceptibility to invasion via differences in granivore identity, abundance, and food preference. We evaluated the effect of postdispersal seed predators on the establishment of invasive, naturalized, and native species within and between adjacent forest and steppe communities of eastern Washington, USA that differ in severity of plant invasion. Seed removal from trays placed within guild-specific exclosures revealed that small mammals were the dominant seed predators in both forest and steppe. Seeds of invasive species (Bromus tectorum, Cirsium arvense) were removed significantly less than the seeds of native (Pseudoroegneria spicata, Balsamorhiza sagittata) and naturalized (Secale cereale, Centaurea cyanus) species. Seed predation limited seedling emergence and establishment in both communities in the absence of competition in a pattern reflecting natural plant abundance: S. cereale was most suppressed, B. tectorum was least suppressed, and P. spicata was suppressed at an intermediate level. Furthermore, seed predation reduced the residual seed bank for all species. Seed mass correlated with seed removal rates in the forest and their subsequent effects on plant recruitment; larger seeds were removed at higher rates than smaller seeds. Our vegetation surveys indicate higher densities and canopy cover of nonnative species occur in the steppe compared with the forest understory, suggesting the steppe may be more susceptible to invasion. Seed predation alone, however, did not result in significant differences in establishment for any species between these communities, presumably due to similar total small-mammal abundance between communities. Consequently, preferential seed predation by small

Effect Of Heavy Metals Stress On Enzyme Activities And Chlorophyll Content Of Pea (Pisum Sativum) And Tomato Plants

International Nuclear Information System (INIS)

Ahmed, B.M.; El Maghrabi, G.; Hashem, M.F.

2013-01-01

The effects of heavy metal stress on the chlorophyll in addition to catalase and peroxidase activities were studied in the leaves and roots of tomato and pea plants. Four groups were studied; the control group and other three groups treated with heavy metals. Group 1HM was treated with 1.0 mg CuSO 4 /l + 0.2 mg CdSO 4 /l + 0.1 mg ZnNO 3 /l every 10 days while in group 5 HM and group 10 HM, the doses were 5 and 10 folds the 1 HM, respectively. Leaves and roots of control and heavy metal-stressed plants were harvested after 10 weeks for chlorophyll determination. The chlorophyll content, especially chlo. b, was significantly decreased with the increase in heavy metals stress in both plants. In leaves of heavy metal-stressed plants, the peroxidase level in different stress levels was increased with increasing stress levels in tomato and pea while catalase was unchanged in leaves of tomato in comparison with the control. The activities of catalase and peroxidase in roots of heavy metal-stressed plants were increased in group 5 HM then decreased in case of group 10 HM. The increase in enzyme activities demonstrated that tomato is more tolerant to heavy metals than pea

Biological and Chemical Aspects of Natural Biflavonoids from Plants: A Brief Review.

Science.gov (United States)

Gontijo, Vanessa Silva; Dos Santos, Marcelo Henrique; Viegas, Claudio

2017-01-01

Biflavonoids belong to a subclass of the plant flavonoids family and are limited to several species in the plant kingdom. In the literature, biflavonoids are extensively reported for their pharmacological properties including anti-inflammatory, antioxidant, inhibitory activity against phospholipase A2 (PLA2) and antiprotozoal activity. These activities have been discovered from the small number of biflavonoid structures that have been investigated, although the natural biflavonoids library is likely to be large. In addition, many medicinal properties and traditional use of plants are attributed to the presence of bioflavonoids among their secondary metabolites. Structurally, biflavonoids are polyphenol compounds comprising of two identical or non-identical flavonflavonoid units joined in a symmetrical or unsymmetrical manner through an alkyl or an alkoxy-based linker of varying length. Due to their chemical and biological importance, several bioprospective phytochemical studies and chemical approaches using coupling and molecular rearrangement strategies have been developed to identify and synthesize new bioactive biflavonoids. In this brief review, we present some basic structural aspects for classification and nomenclature of bioflavonoids and a compilation of the literature data published in the last 7 years, concerning the discovery of new natural biflavonoids of plant origin and their pharmacological and biological properties. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Chemopreventive effect of natural dietary compounds on xenobiotic-induced toxicity

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Jia-Ching Wu

2017-01-01

Full Text Available Contaminants (or pollutants that affect human health have become an important issue, spawning a myriad of studies on how to prevent harmful contaminant-induced effects. Recently, a variety of biological functions of natural dietary compounds derived from consumed foods and plants have been demonstrated in a number of studies. Natural dietary compounds exhibited several beneficial effects for the prevention of disease and the inhibition of chemically-induced carcinogenesis. Contaminant-induced toxicity and carcinogenesis are mostly attributed to the mutagenic activity of reactive metabolites and the disruption of normal biological functions. Therefore, the metabolic regulation of hazardous chemicals is key to reducing contaminant-induced adverse health effects. Moreover, promoting contaminant excretion from the body through Phase I and II metabolizing enzymes is also a useful strategy for reducing contaminant-induced toxicity. This review focuses on summarizing the natural dietary compounds derived from common dietary foods and plants and their possible mechanisms of action in the prevention/suppression of contaminant-induced toxicity.

Laccase Enzymes in Inocula Pleurotus spp

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Nora García-Oduardo

2017-01-01

Full Text Available The cultivation of edible and medicinal mushrooms Pleurotus has been aimed at promoting alternative management for agricultural products. This basidiomicete has been the subject of numerous studies because of its fruiting body constitutes a food, being a producer of enzymes with industrial interest and for its ability of biotransformation of lignocellulosic substrates. Pleurotus inocula in the established technology for growing edible and medicinal mushrooms in the CEBI Research- Production Plant were performed using sorghum or wheat. However, it is possible to expand the possibilities with other substrates. In this paper, the results of laccase enzymes production in inocula prepared with sorghum, corn and coffee pulp with two strains Pleurotus ostreatus CCEBI 3021 and Pleurotus ostreatus CCEBI 3024 are presented. The period of preparation of seed reaches 15-21 days, the measurements of laccase activity were performed in periods of seven days. Extraction of crude enzyme was performed in aqueous phase, the determination of the laccase enzyme activity, using guaiacol as substrate. The results obtained in this work with studies in previous work using sorghum as inocula are compared. It is found that higher yields are obtained laccase in coffee pulp. This study contributes to the theoretical knowledge and to provide alternatives for securing the production process of the plant.

Trigeneration scheme for a natural gas liquids extraction plant in the Middle East

International Nuclear Information System (INIS)

Eveloy, Valérie; Rodgers, Peter; Popli, Sahil

2014-01-01

Highlights: • Trigeneration scheme tailored to natural gas liquids extraction plant. • High ambient temperature and RH conditions in the Persian Gulf. • Absorption refrigeration powered by gas turbine (GT) exhaust gas waste heat. • GT compressor inlet air- and process gas cooling, process gas heating. • Significant OPEX and primary energy savings, favorable payback period and net present value. - Abstract: Natural gas processing plants in the Persian Gulf face extreme climatic conditions that constrain their gas turbine (GT) power generation and cooling capacities. However, due to a past history of low hydrocarbon prices, such plants have not fully exploited their waste heat recovery potential to date. The techno-economic performance of a combined cooling, heating and power (CCHP) scheme designed to enhance the energy efficiency of a major natural gas liquids extraction plant in the Persian Gulf is assessed. The trigeneration scheme utilizes double-effect water–lithium bromide absorption refrigeration powered by steam generated from GT exhaust gas waste heat to provide both GT compressor inlet air- and process gas cooling. Part of the generated steam is also used for process gas heating. Thermodynamic modeling reveals that recovery of 82 MW of GT waste heat would provide additional cooling and heating capacities of 75 MW and 24 MW to the plant, respectively, thereby permitting elimination of a 28 MW GT, and existing cooling and heating equipment. GT compressor inlet air cooling alone yields approximately 151 GW h of additional electric power annually, highlighting the effectiveness of absorption refrigeration in meeting compressor inlet air cooling loads throughout the year in the Gulf climate. The overall net annual operating expenditure savings contributed by the CCHP system would average approximately 14.6 million US$ over its lifespan, which corresponds to average yearly savings of 190 MMSCM of natural gas. The CCHP scheme economic payback period is

Analysis and design of Fuel Cycle Plant for natural phenomena hazards

International Nuclear Information System (INIS)

Horsager, B.K.

1985-01-01

A description of the Design Basis and the analysis and design methods used for natural phenomena at the Fuel Cycle Plant at Hanford, Washington is presented. A physical description of the main process facility and the auxiliary emergency and support facilities is given. The mission of the facility is presented and a brief description of the processes which will take place within the facility is given. The Design Criteria and design bases for natural phenomena including tornados, earthquakes and volcanic eruptions are described

Species diversity of plant communities from territories with natural origin radionuclides contamination

Energy Technology Data Exchange (ETDEWEB)

Kaneva, A.V.; Belykh, E.S.; Maystrenko, T.A.; Grusdev, B.I.; Zainullin, V.G.; Vakhrusheva, O.M. [Institute of Biology, Komi Scientific Center, Ural Division of RAS, Syktyvkar, 167982 (Russian Federation); Oughton, D. [Norwegian University of Life Sciences, P.O. Box 5003, NO-1432 Aas (Norway)

2014-07-01

Since plants dominate every landscape, the impact of any environmental stressor on plants can directly affect the structure and function of an ecosystem, resulting in decreased primary productivity and degradation of wildlife habitat. The investigation goal of the present research was to study how vascular plant species' composition at a former radium mining site could be related to i) soil contamination with heavy metals and uranium and thorium decay chain radionuclides and ii) soil agrochemical properties. Between the 1930's and 1950's, the commercial extraction of radium, storage of the uranium mill tailings and radium production wastes, together with deactivation of the site with a mixture of sand and gravel completely destroyed plant communities in the vicinity of Vodny settlement (Komi Republic, Russia). The plant cover recovery started more than 60 years ago, and resulted in overgrowing with common grassland plant species. Three meadow sites were investigated, one with low contamination (on the territory of former radium production plant), one with high contamination (waste storage cell) and a reference sites out of the radiochemical plant zone of influence, but with similar natural conditions. Geo-botanical descriptions revealed 134 vascular plant species from 34 families in the meadow communities studied. The greatest richness was seen for Poaceae, Asteraceae, Rosaceae and Fabaceae families; others had 1-5 species. The highest richness in diversity was seen at reference sites with 95 vascular plant species. 87 species were registered on low contaminated sites and 75 species on high contaminated. Perennial herbs were the dominant life form on all the studied meadow communities. Arboreal species expansion in vegetation was noted at both experimental and reference sites. Shannon index calculations indicated a significant (p<0.05) decrease in species diversity on sample areas of the highly contaminated radioactive waste storage cell. Mean values

Development and planning of plant for the high-pressure extraction of natural products

Energy Technology Data Exchange (ETDEWEB)

Eggers, R; Tschiersch, R [Thyssen Industrie A.G., Witten (Germany, F.R.)

1978-11-01

Important criteria in the designing of plant for the recovery of carrier or extract are reviewed, especially for the extraction of natural products with supercritical CO/sub 2/. The quantities to be determined in the planning of a large-scale plant are outlined and a typical process, the extraction of spices, is discussed in detail. The plant components and assemblies are presented together with their particular process engineering and construction characteristics. Finally, the thermodynamic aspects are dealt with in more detail and ways of optimizing a large-scale plant and reducing the power consumption are outlined. Particular attention is paid to the question of optimization regarding the most economic method of operation of such a plant in the future.

Tyrosine biosynthesis, metabolism, and catabolism in plants.

Science.gov (United States)

Schenck, Craig A; Maeda, Hiroshi A

2018-05-01

L-Tyrosine (Tyr) is an aromatic amino acid (AAA) required for protein synthesis in all organisms, but synthesized de novo only in plants and microorganisms. In plants, Tyr also serves as a precursor of numerous specialized metabolites that have diverse physiological roles as electron carriers, antioxidants, attractants, and defense compounds. Some of these Tyr-derived plant natural products are also used in human medicine and nutrition (e.g. morphine and vitamin E). While the Tyr biosynthesis and catabolic pathways have been extensively studied in microbes and animals, respectively, those of plants have received much less attention until recently. Accumulating evidence suggest that the Tyr biosynthetic pathways differ between microbes and plants and even within the plant kingdom, likely to support the production of lineage-specific plant specialized metabolites derived from Tyr. The interspecies variations of plant Tyr pathway enzymes can now be used to enhance the production of Tyr and Tyr-derived compounds in plants and other synthetic biology platforms. Copyright © 2018 Elsevier Ltd. All rights reserved.

The fungal cultivar of leaf-cutter ants produces specific enzymes in response to different plant substrates

Energy Technology Data Exchange (ETDEWEB)

Khadempour, Lily [Department of Bacteriology, University of Wisconsin-Madison, Madison WI 53706 USA; Department of Zoology, University of Wisconsin-Madison, Madison WI 53706 USA; Department of Energy Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison WI 53706 USA; Burnum-Johnson, Kristin E. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland WA 99352 USA; Baker, Erin S. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland WA 99352 USA; Nicora, Carrie D. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland WA 99352 USA; Webb-Robertson, Bobbie-Jo M. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland WA 99352 USA; White, Richard A. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland WA 99352 USA; Monroe, Matthew E. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland WA 99352 USA; Huang, Eric L. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland WA 99352 USA; Smith, Richard D. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland WA 99352 USA; Currie, Cameron R. [Department of Bacteriology, University of Wisconsin-Madison, Madison WI 53706 USA; Department of Energy Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison WI 53706 USA

2016-10-26

Herbivores use symbiotic microbes to help gain access to energy and nutrients from plant material. Leaf-cutter ants are a paradigmatic example, having tremendous impact on their ecosystems as dominant generalist herbivores through cultivation of a fungus, Leucoagaricus gongylophorous. Here we examine how this mutualism could facilitate the flexible substrate incorporation of the ants by providing leaf-cutter ant subcolonies four substrate types: leaves, flowers, oats, and a mixture of all three. Through metaproteomic analysis of the fungus gardens, we were able to identify and quantify 1766 different fungal proteins, including 161 biomass-degrading enzymes. This analysis revealed that fungal protein profiles were significantly different between subcolonies fed different substrates with the highest abundance of cellulolytic enzymes observed in the leaf and flower treatments. When the fungus garden is provided with leaves and flowers, which contain the majority of their energy in recalcitrant material, it increases its production of proteins that break down cellulose: endoglucanases, exoglucanase and β-glucosidase. Further, the complete metaproteomes for the leaves and flowers treatments were very similar, the mixed treatment closely resembled the treatment with oats alone. This suggests that when provided a mixture of substrates, the fungus garden preferentially produces enzymes necessary for breakdown of simpler, more digestible substrates. This flexible, substrate-specific response of the fungal cultivar allows the leaf-cutter ants to derive energy from a wide range of substrates, which may contribute to their ability to be dominant generalist herbivores.

Phytase, a new life for an “old” enzyme

Science.gov (United States)

Phytase represents a group of phosphohydrolytic enzymes that initiate stepwise removals of phosphate from phytate. Simple-stomached species such as swine, poultry, and fish require extrinsic phytase to digest phytate: the major form of phosphorus in plant feeds. Consequently, this enzyme is suppleme...

Structure, function and regulation of the enzymes in the starch biosynthetic pathway.

Energy Technology Data Exchange (ETDEWEB)

Geiger, Jim

2013-11-30

Starch is the major reserve polysaccharide in nature and accounts for the majority of the caloric intact of humans. It is also gaining importance as a renewable and biodegradable industrial material. There is burgeoning interest in increasing the amount and altering the properties of the plant starches by plant genetic modification. A rational approach to this effort will require a detailed, atomic-level understanding of the enzymatic processes that produce the starch granule. The starch granule is a complex particle made up of alternating layers of crystalline and amorphous lamellae. It consists of two types of polymer, amylose, a polymer of relatively long chains of α-1,4-linked glucans that contain virtually no branches, and amylopectin, which is highly branched and contains much shorter chains. This complex structure is synthesized by the coordinate activities of the starch synthases (SS), which elongate the polysaccharide chain by addition of glucose units via α-1,4 linkages using ADP- glucose as a donor, and branching enzymes (BE), which branch the polysaccharide chain by cleavage of α₋1,4 linkages and subsequent re-attachment via α₋1,6 linkages. Several isoforms of both starch synthase (SS) and branching enzyme (BE) are found in plants, including SSI, SSII, SSIII and granule- bound SS (GBSS), and SBEI, SBEIIa and SBEIIb. These isoforms have different activities and substrate and product specificities and play different roles in creating the granule and determining the properties of the resulting starch. The overarching goal of this proposal is to begin to understand the regulation and specificities of these enzymes at the atomic level. High-resolution X-ray structures of these enzymes bound to substrates and products will be determined to visualize the molecular interactions responsible for the properties of the enzymes. Hypotheses regarding these issues will then be tested using mutagenesis and enzyme assays. To date, we have determined the

Core@shell Nanoparticles: Greener Synthesis Using Natural Plant Products

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Mehrdad Khatami

2018-03-01

Full Text Available Among an array of hybrid nanoparticles, core-shell nanoparticles comprise of two or more materials, such as metals and biomolecules, wherein one of them forms the core at the center, while the other material/materials that were located around the central core develops a shell. Core-shell nanostructures are useful entities with high thermal and chemical stability, lower toxicity, greater solubility, and higher permeability to specific target cells. Plant or natural products-mediated synthesis of nanostructures refers to the use of plants or its extracts for the synthesis of nanostructures, an emerging field of sustainable nanotechnology. Various physiochemical and greener methods have been advanced for the synthesis of nanostructures, in contrast to conventional approaches that require the use of synthetic compounds for the assembly of nanostructures. Although several biological resources have been exploited for the synthesis of core-shell nanoparticles, but plant-based materials appear to be the ideal candidates for large-scale green synthesis of core-shell nanoparticles. This review summarizes the known strategies for the greener production of core-shell nanoparticles using plants extract or their derivatives and highlights their salient attributes, such as low costs, the lack of dependence on the use of any toxic materials, and the environmental friendliness for the sustainable assembly of stabile nanostructures.

Characterization of cysteine-degrading and H2S-releasing enzymes of higher plants - from the field to the test tube and back.

Science.gov (United States)

Papenbrock, J; Riemenschneider, A; Kamp, A; Schulz-Vogt, H N; Schmidt, A

2007-09-01

Due to the clean air acts and subsequent reduction of emission of gaseous sulfur compounds sulfur deficiency became one of the major nutrient disorders in Northern Europe. Typical sulfur deficiency symptoms can be diagnosed. Especially plants of the Cruciferae family are more susceptible against pathogen attack. Sulfur fertilization can in part recover or even increase resistance against pathogens in comparison to sulfur-deficient plants. The term sulfur-induced resistance (SIR) was introduced, however, the molecular basis for SIR is largely unknown. There are several sulfur-containing compounds in plants which might be involved in SIR, such as high levels of thiols, glucosinolates, cysteine-rich proteins, phytoalexins, elemental sulfur, or H2S. Probably more than one strategy is used by plants. Species- or even variety-dependent differences in the development of SIR are probably used. Our research focussed mainly on the release of H2S as defence strategy. In field experiments using different BRASSICA NAPUS genotypes it was shown that the genetic differences among BRASSICA genotypes lead to differences in sulfur content and L-cysteine desulfhydrase activity. Another field experiment demonstrated that sulfur supply and infection with PYRENOPEZIZA BRASSICA influenced L-cysteine desulfhydrase activity in BRASSICA NAPUS. Cysteine-degrading enzymes such as cysteine desulfhydrases are hypothesized to be involved in H2S release. Several L- and D-cysteine-specific desulfhydrase candidates have been isolated and partially analyzed from the model plant ARABIDOPSIS THALIANA. However, it cannot be excluded that H2S is also released in a partial back reaction of O-acetyl-L-serine(thiol)lyase or enzymes not yet characterized. For the exact determination of the H2S concentration in the cell a H2S-specific microsensor was used the first time for plant cells. The transfer of the results obtained for application back on BRASSICA was initiated.

Integrating natural and social science perspectives on plant disease risk, management and policy formulation

Science.gov (United States)

Mills, Peter; Dehnen-Schmutz, Katharina; Ilbery, Brian; Jeger, Mike; Jones, Glyn; Little, Ruth; MacLeod, Alan; Parker, Steve; Pautasso, Marco; Pietravalle, Stephane; Maye, Damian

2011-01-01

Plant diseases threaten both food security and the botanical diversity of natural ecosystems. Substantial research effort is focused on pathogen detection and control, with detailed risk management available for many plant diseases. Risk can be assessed using analytical techniques that account for disease pressure both spatially and temporally. We suggest that such technical assessments of disease risk may not provide an adequate guide to the strategies undertaken by growers and government to manage plant disease. Instead, risk-management strategies need to account more fully for intuitive and normative responses that act to balance conflicting interests between stakeholder organizations concerned with plant diseases within the managed and natural environments. Modes of effective engagement between policy makers and stakeholders are explored in the paper, together with an assessment of such engagement in two case studies of contemporary non-indigenous diseases in one food and in one non-food sector. Finally, a model is proposed for greater integration of stakeholders in policy decisions. PMID:21624923

Monoterpenes as inhibitors of digestive enzymes and counter-adaptations in a specialist avian herbivore.

Science.gov (United States)

Kohl, Kevin D; Pitman, Elizabeth; Robb, Brecken C; Connelly, John W; Dearing, M Denise; Forbey, Jennifer Sorensen

2015-05-01

Many plants produce plant secondary metabolites (PSM) that inhibit digestive enzymes of herbivores, thus limiting nutrient availability. In response, some specialist herbivores have evolved digestive enzymes that are resistant to inhibition. Monoterpenes, a class of PSMs, have not been investigated with respect to the interference of specific digestive enzymes, nor have such interactions been studied in avian herbivores. We investigated this interaction in the Greater Sage-Grouse (Phasianidae: Centrocercus urophasianus), which specializes on monoterpene-rich sagebrush species (Artemisia spp.). We first measured the monoterpene concentrations in gut contents of free-ranging sage-grouse. Next, we compared the ability of seven individual monoterpenes present in sagebrush to inhibit a protein-digesting enzyme, aminopeptidase-N. We also measured the inhibitory effects of PSM extracts from two sagebrush species. Inhibition of aminopeptidase-N in sage-grouse was compared to inhibition in chickens (Gallus gallus). We predicted that sage-grouse enzymes would retain higher activity when incubated with isolated monoterpenes or sagebrush extracts than chicken enzymes. We detected unchanged monoterpenes in the gut contents of free-ranging sage-grouse. We found that three isolated oxygenated monoterpenes (borneol, camphor, and 1,8-cineole) inhibited digestive enzymes of both bird species. Camphor and 1,8-cineole inhibited enzymes from chickens more than from sage-grouse. Extracts from both species of sagebrush had similar inhibition of chicken enzymes, but did not inhibit sage-grouse enzymes. These results suggest that specific monoterpenes may limit the protein digestibility of plant material by avian herbivores. Further, this work presents additional evidence that adaptations of digestive enzymes to plant defensive compounds may be a trait of specialist herbivores.

DETERMINATION OF ENZYMES PRODUCED BY CERIPORIOPSIS SUBVERMISPORA DURING PRETREATMENT OF DIFFERENT BIOMASS SOURCES

Directory of Open Access Journals (Sweden)

Miroslav Ondrejovič

2012-02-01

Full Text Available The aim of this paper was to study of lignocellulolytic enzymes producing by Ceriporiopsis subvermispora during its cultivation on three types of plant biomass differentiated by chemical composition and physical properties (wheat straw, pine and poplar wood. The activity of lignocellulolytic enzymes in cultivation medium was determined by catalytic transformation of their natural substrates to products which were detected by photometric methods. Cellulase activities were very low while xylanases predominated. Wheat straw was best substrate for production of cellulases (4.38 U/mL and xylanases (23.34 U/mL. The maximum activity of cellulase and xylanase was reached at 8th and 3rd day, respectively. Laccase activity reached the maximum after 16 days and then gradually decreased. The best substrate for production of laccases was poplar wood (1.67 U/mL.

α-Glucosidase inhibitory activity of selected Malaysian plants

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Dzatil Awanis Mohd Bukhari

2017-01-01

Full Text Available Diabetes is a common metabolic disease indicated by unusually high plasma glucose level that can lead to major complications such as diabetic neuropathy, retinopathy, and cardiovascular diseases. One of the effective therapeutic managements of the disease is to reduce postprandial hyperglycemia through inhibition of α-glucosidase, a carbohydrate-hydrolyzing enzyme to retard overall glucose absorption. In recent years, a plenty of research works have been conducted looking for novel and effective α-glucosidase inhibitors (AGIs from natural sources as alternatives for the synthetic AGI due to their unpleasant side effects. Plants and herbs are rich with secondary metabolites that have massive pharmaceutical potential. Besides, studies showed that phytochemicals such as flavonoids, alkaloids, terpenoids, anthocyanins, glycosides, and phenolic compounds possess significant inhibitory activity against α-glucosidase enzyme. Malaysia is a tropical country that is rich with medicinal herbs. In this review, we focus on eight Malaysian plants with the potential as AGI to develop a potential functional food or lead compounds against diabetes.

α-Glucosidase Inhibitory Activity of Selected Malaysian Plants.

Science.gov (United States)

Mohd Bukhari, Dzatil Awanis; Siddiqui, Mohammad Jamshed; Shamsudin, Siti Hadijah; Rahman, Md Mukhlesur; So'ad, Siti Zaiton Mat

2017-01-01

Diabetes is a common metabolic disease indicated by unusually high plasma glucose level that can lead to major complications such as diabetic neuropathy, retinopathy, and cardiovascular diseases. One of the effective therapeutic managements of the disease is to reduce postprandial hyperglycemia through inhibition of α-glucosidase, a carbohydrate-hydrolyzing enzyme to retard overall glucose absorption. In recent years, a plenty of research works have been conducted looking for novel and effective α-glucosidase inhibitors (AGIs) from natural sources as alternatives for the synthetic AGI due to their unpleasant side effects. Plants and herbs are rich with secondary metabolites that have massive pharmaceutical potential. Besides, studies showed that phytochemicals such as flavonoids, alkaloids, terpenoids, anthocyanins, glycosides, and phenolic compounds possess significant inhibitory activity against α-glucosidase enzyme. Malaysia is a tropical country that is rich with medicinal herbs. In this review, we focus on eight Malaysian plants with the potential as AGI to develop a potential functional food or lead compounds against diabetes.

Kainic Acid-Induced Excitotoxicity Experimental Model: Protective Merits of Natural Products and Plant Extracts

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Nur Shafika Mohd Sairazi

2015-01-01

Full Text Available Excitotoxicity is well recognized as a major pathological process of neuronal death in neurodegenerative diseases involving the central nervous system (CNS. In the animal models of neurodegeneration, excitotoxicity is commonly induced experimentally by chemical convulsants, particularly kainic acid (KA. KA-induced excitotoxicity in rodent models has been shown to result in seizures, behavioral changes, oxidative stress, glial activation, inflammatory mediator production, endoplasmic reticulum stress, mitochondrial dysfunction, and selective neurodegeneration in the brain upon KA administration. Recently, there is an emerging trend to search for natural sources to combat against excitotoxicity-associated neurodegenerative diseases. Natural products and plant extracts had attracted a considerable amount of attention because of their reported beneficial effects on the CNS, particularly their neuroprotective effect against excitotoxicity. They provide significant reduction and/or protection against the development and progression of acute and chronic neurodegeneration. This indicates that natural products and plants extracts may be useful in protecting against excitotoxicity-associated neurodegeneration. Thus, targeting of multiple pathways simultaneously may be the strategy to maximize the neuroprotection effect. This review summarizes the mechanisms involved in KA-induced excitotoxicity and attempts to collate the various researches related to the protective effect of natural products and plant extracts in the KA model of neurodegeneration.

Potential local use of natural gas or LNG from Hammerfest LNG plant

International Nuclear Information System (INIS)

Neeraas, Bengt Olav

1999-01-01

A base-load LNG plant is planned to be built in Norway, near by the northern most city in the world, Hammerfest. Natural gas from the Snoehvit-field will be transported by pipeline to Melkoeya, a few kilometres from Hammerfest, where the liquefaction plant is planned to be located. SINTEF Energy Research has performed a study in co-operation with the local authorities on potentials for the use of LNG and natural gas locally in the Hammerfest region. Combined power and heat production by lean-burn gas engine, low temperature freezing of high quality products by use of LNG cold and drying of fish products are some of the identified fields for the use of natural gas and LNG. The establishment of an industrial area, with fish processing industry and a central freezing storage near by Hammerfest has been suggested. The gas may be transported locally either as LNG, by tank lorry or container, or as gas in a small pipeline, depending on distance, amount and the actual use. (author)

Plants and other natural products used in the management of oral infections and improvement of oral health.

Science.gov (United States)

Chinsembu, Kazhila C

2016-02-01

Challenges of resistance to synthetic antimicrobials have opened new vistas in the search for natural products. This article rigorously reviews plants and other natural products used in oral health: Punica granatum L. (pomegranate), Matricaria recutita L. (chamomile), Camellia sinensis (L.) Kuntze (green tea), chewing sticks made from Diospyros mespiliformis Hochst. ex A.D.C., Diospyros lycioides Desf., and Salvadora persica L. (miswak), honey and propolis from the manuka tree (Leptospermum scoparium J.R. Forst. & G. Forst.), rhein from Rheum rhabarbarum L. (rhubarb), dried fruits of Vitis vinifera L. (raisins), essential oils, probiotics and mushrooms. Further, the review highlights plants from Africa, Asia, Brazil, Mexico, Europe, and the Middle East. Some of the plants' antimicrobial properties and chemical principles have been elucidated. While the use of natural products for oral health is prominent in resource-poor settings, antimicrobial testing is mainly conducted in the following countries (in decreasing order of magnitude): India, South Africa, Brazil, Japan, France, Egypt, Iran, Mexico, Kenya, Switzerland, Nigeria, Australia, Uganda, and the United Kingdom. While the review exposes a dire gap for more studies on clinical efficacy and toxicity, the following emerging trend was noted: basic research on plants for oral health is mainly done in Brazil, Europe and Australia. Brazil, China, India and New Zealand generally conduct value addition of natural products for fortification of toothpastes. African countries focus on bioprospecting and primary production of raw plants and other natural products with antimicrobial efficacies. The Middle East and Egypt predominantly research on plants used as chewing sticks. More research and funding are needed in the field of natural products for oral health, especially in Africa where oral diseases are fuelled by human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS). Copyright © 2015 Elsevier B

Comparison of Natural and Engineered Chlorophenol Bioremediation Enzymes

Science.gov (United States)

2015-02-26

herein addresses the urgent need to incorporate biological strategies into environmental restoration efforts ( bioremediation ) that focus on the catalytic... Bioremediation Enzymes The views, opinions and/or findings contained in this report are those of the author(s) and should not contrued as an official Department...Army Research Office P.O. Box 12211 Research Triangle Park, NC 27709-2211 dehaloperoxidase, bioremediation , halophenol, Amphitrite ornata, marine

Novel mutants of Erwinia carotovora subsp. carotovora defective in the production of plant cell wall degrading enzymes generated by Mu transpososome-mediated insertion mutagenesis.

Science.gov (United States)

Laasik, Eve; Ojarand, Merli; Pajunen, Maria; Savilahti, Harri; Mäe, Andres

2005-02-01

As in Erwinia carotovora subsp. carotovora the regulation details of the main virulence factors, encoding extracellular enzymes that degrade the plant cell wall, is only rudimentally understood, we performed a genetic screen to identify novel candidate genes involved in the process. Initially, we used Mu transpososome-mediated mutagenesis approach to generate a comprehensive transposon insertion mutant library of ca. 10000 clones and screened the clones for the loss of extracellular enzyme production. Extracellular enzymes production was abolished by mutations in the chromosomal helEcc, trkAEcc yheLEcc, glsEcc, igaAEcc and cysQEcc genes. The findings reported here demonstrate that we have isolated six new representatives that belong to the pool of genes modulating the production of virulence factors in E. carotovora.

Engineering Cellulase Enzymes for Bioenergy

Science.gov (United States)

Atreya, Meera Elizabeth

Sustainable energy sources, such as biofuels, offer increasingly important alternatives to fossil fuels that contribute less to global climate change. The energy contained within cellulosic biofuels derives from sunlight energy stored in the form of carbon-carbon bonds comprising sugars such as glucose. Second-generation biofuels are produced from lignocellulosic biomass feedstocks, including agricultural waste products and non-food crops like Miscanthus, that contain lignin and the polysaccharides hemicellulose and cellulose. Cellulose is the most abundant biological material on Earth; it is a polymer of glucose and a structural component of plant cell walls. Accessing the sugar is challenging, as the crystalline structure of cellulose resists degradation; biochemical and thermochemical means can be used to depolymerize cellulose. Cellulase enzymes catalyze the biochemical depolymerization of cellulose into glucose. Glucose can be used as a carbon source for growth of a biofuel-producing microorganism. When it converts glucose to a hydrocarbon fuel, this microbe completes the biofuels process of transforming sunlight energy into accessible, chemical energy capable of replacing non-renewable transportation fuels. Due to strong intermolecular interactions between polymer chains, cellulose is significantly more challenging to depolymerize than starch, a more accessible polymer of glucose utilized in first-generation biofuels processes (often derived from corn). While most mammals cannot digest cellulose (dietary fiber), certain fungi and bacteria produce cellulase enzymes capable of hydrolyzing it. These organisms secrete a wide variety of glycoside hydrolase and other classes of enzymes that work in concert. Because cellulase enzymes are slow-acting and expensive to produce, my aim has been to improve the properties of these enzymes as a means to make a cellulosic biofuels process possible that is more efficient and, consequently, more economical than current

BAKERY ENZYMES IN CEREAL TECHNOLOGIES

Directory of Open Access Journals (Sweden)

Václav Koman

2012-10-01

Full Text Available Normal 0 21 false false false SK X-NONE X-NONE Bread is the most common and traditional food in the world. For years, enzymes such as malt and fungal alpha-amylase have been used in bread making. Due to the changes in the baking industry and the ever-increasing demand for more natural products, enzymes have gained real importance in bread-making. If an enzyme is added, it is often destroyed by the heat during the baking process. For generations, enzymes have been used for the improvement of texture and appearance, enhancement of nutritional values and generation of appealing flavours and aromas. Enzymes used in bakery industry constitute nearly one third of the market. The bakery products have undergone radical improvements in quality over the past years in terms of flavour, texture and shelf-life. The the biggest contributor for these improvementsis the usage of enzymes. Present work seeks to systematically describe bakery enzymes, their classification, benefits, usage and chemical reactions in the bread making process.doi:10.5219/193

The dynamic basis of energy transduction in enzymes.

Science.gov (United States)

Somogyi, B; Welch, G R; Damjanovich, S

1984-09-06

The most important idea underlying our treatment herein is the unity of the enzyme molecule and the medium. Appreciation of this relationship is vital, if enzymology is to graduate from its present reductionistic status to a more holistic posture. Enzymes are biological entities firstly, and isolated objects of physicochemical analysis secondly. Perhaps the most crucial 'biological lesson', particularly apropos of enzymes in intermediary metabolism, concerns the 'cytosociology' of enzyme action in vivo [94,128]. The natural habitat of many enzymes in the living cell is far different from that in bulk aqueous solution in vitro. In order to obtain a real grasp of the nature of enzyme function, one must ultimately couch enzymology in concepts emerging from contemporary cell biology [95]. Notwithstanding, analysis precedes synthesis; and one must needs begin with the individual enzyme molecule. The trenchant efforts of the physical chemist and the organic chemist have produced a wealth of information on the nature of the binding and catalytic events at the enzyme active site. While it is not yet possible to explain precisely the complete sequence of events in the catalytic process, nevertheless, the basic mechanisms by which enzymes effect catalysis (i.e., reduce activation energy) now seem apparent [81,129]. The new frontier is to be found, in exploring the dynamic role of the protein matrix [17]. Not only does the protein provide the 3-D scaffolding for active-site processes, but, more importantly, it serves as the local solvent for the bound chemical subsystem. Thus, the dynamical aspects of enzyme catalysis (for thermally based systems) must arise from the fluctuational properties of the protein molecule. This notion is the common denominator in all of the models in subsection IIC. It is the anisotropic nature of this fluctuational behavior, which would characterize the energy-transduction phenomenon leading to localized catalytic events at the active-site. In

Salinity and Salicylic Acid Interactions in Affecting Nitrogen Assimilation, Enzyme Activity, Ions Content and Translocation Rate of Maize Plants

International Nuclear Information System (INIS)

Khodary, S.E.A.; Moussa, H.R.

2002-01-01

This study was carried out to establish the relationship between nitrogen metabolism, enzyme activity, ions concentration as well as the translocation rate (TR) of carbohydrates and salicylic acid (SA) in salt-stressed maize (Zea mays L). Salicylic acid plus salinity treatment highly significantly increased: nucleic acids (DNA and RNA), protein content, phosphoenolpyruvate carboxylase (PEPCase) and nitrate reductase (NR) and inhibited nucleases (DNase and RNase) activities compared with Na CI-treated plants. In addition, the ionic levels of potassium (K), phosphorus (P), nitrate (NO 3 ) and the translocation rate of the labelled photo assimilates have also been stimulated while sodium (Na) ions content was decreased. It is concluded that, salinazid maize plants might show an enhancement in their growth pattern upon salicylic acid application

Brassinosteroid-induced CO2 assimilation is associated with increased stability of redox-sensitive photosynthetic enzymes in the chloroplasts in cucumber plants

International Nuclear Information System (INIS)

Jiang, Yu Ping; Cheng, Fei; Zhou, Yan Hong; Xia, Xiao Jian; Mao, Wei Hua; Shi, Kai; Chen, Zhi Xiang; Yu, Jing Quan

2012-01-01

Highlights: ► Activity of certain Calvin cycle enzymes and CO 2 assimilation are induced by BRs. ► BRs upregulate the activity of the ascorbate–glutathione cycle in the chloroplasts. ► BRs increase the chloroplast thiol reduction state. ► A BR-induced reducing environment increases the stability of photosynthetic enzymes. -- Abstract: Brassinosteroids (BRs) play important roles in plant growth, development, photosynthesis and stress tolerance; however, the mechanism underlying BR-enhanced photosynthesis is currently unclear. Here, we provide evidence that an increase in the BR level increased the quantum yield of PSII, activities of Rubisco activase (RCA) and fructose-1,6-bisphosphatase (FBPase), and CO 2 assimilation. BRs upregulated the transcript levels of genes and activity of enzymes involved in the ascorbate–glutathione cycle in the chloroplasts, leading to an increased ratio of reduced (GSH) to oxidized (GSSG) glutathione in the chloroplasts. An increased GSH/GSSG ratio protected RCA from proteolytic digestion and increased the stability of redox-sensitive enzymes in the chloroplasts. These results strongly suggest that BRs are capable of regulating the glutathione redox state in the chloroplasts through the activation of the ascorbate–glutathione cycle. The resulting increase in the chloroplast thiol reduction state promotes CO 2 assimilation, at least in part, by enhancing the stability and activity of redox-sensitive photosynthetic enzymes through post-translational modifications.

Plant-plant interactions mediate the plastic and genotypic response of Plantago asiatica to CO2: an experiment with plant populations from naturally high CO2 areas.

Science.gov (United States)

van Loon, Marloes P; Rietkerk, Max; Dekker, Stefan C; Hikosaka, Kouki; Ueda, Miki U; Anten, Niels P R

2016-06-01

The rising atmospheric CO2 concentration ([CO2]) is a ubiquitous selective force that may strongly impact species distribution and vegetation functioning. Plant-plant interactions could mediate the trajectory of vegetation responses to elevated [CO2], because some plants may benefit more from [CO2] elevation than others. The relative contribution of plastic (within the plant's lifetime) and genotypic (over several generations) responses to elevated [CO2] on plant performance was investigated and how these patterns are modified by plant-plant interactions was analysed. Plantago asiatica seeds originating from natural CO2 springs and from ambient [CO2] sites were grown in mono stands of each one of the two origins as well as mixtures of both origins. In total, 1944 plants were grown in [CO2]-controlled walk-in climate rooms, under a [CO2] of 270, 450 and 750 ppm. A model was used for upscaling from leaf to whole-plant photosynthesis and for quantifying the influence of plastic and genotypic responses. It was shown that changes in canopy photosynthesis, specific leaf area (SLA) and stomatal conductance in response to changes in growth [CO2] were mainly determined by plastic and not by genotypic responses. We further found that plants originating from high [CO2] habitats performed better in terms of whole-plant photosynthesis, biomass and leaf area, than those from ambient [CO2] habitats at elevated [CO2] only when both genotypes competed. Similarly, plants from ambient [CO2] habitats performed better at low [CO2], also only when both genotypes competed. No difference in performance was found in mono stands. The results indicate that natural selection under increasing [CO2] will be mainly driven by competitive interactions. This supports the notion that plant-plant interactions have an important influence on future vegetation functioning and species distribution. Furthermore, plant performance was mainly driven by plastic and not by genotypic responses to changes in

The role of enzymes in fungus-growing ant evolution

DEFF Research Database (Denmark)

de Fine Licht, Henrik Hjarvard

behaviour. Here we report the first large-scale comparative study on fungus garden enzyme profiles and show that various interesting changes can be documented. A more detailed analysis of laccase expression, an enzyme that is believed to oxidize phenols in defensive secondary plant compounds such as tannins...

Analysis of natural variation in bermudagrass (Cynodon dactylon) reveals physiological responses underlying drought tolerance.

Science.gov (United States)

Shi, Haitao; Wang, Yanping; Cheng, Zhangmin; Ye, Tiantian; Chan, Zhulong

2012-01-01

Bermudagrass (Cynodon dactylon) is a widely used warm-season turfgrass and one of the most drought tolerant species. Dissecting the natural variation in drought tolerance and physiological responses will bring us powerful basis and novel insight for plant breeding. In the present study, we evaluated the natural variation of drought tolerance among nine bermudagrass varieties by measuring physiological responses after drought stress treatment through withholding water. Three groups differing in drought tolerance were identified, including two tolerant, five moderately tolerant and two susceptible varieties. Under drought stress condition, drought sensitive variety (Yukon) showed relative higher water loss, more severe cell membrane damage (EL), and more accumulation of hydrogen peroxide (H₂O₂) and malondialdehyde (MDA), while drought tolerant variety (Tifgreen) exhibited significantly higher antioxidant enzymes activities. Further results indicated that drought induced cell injury in different varieties (Yukon, SR9554 and Tifgreen) exhibited liner correlation with leaf water content (LWC), H₂O₂ content, MDA content and antioxidant enzyme activities. Additionally, Tifgreen plants had significantly higher levels of osmolytes (proline level and soluble sugars) when compared with Yukon and SR9554 under drought stress condition. Taken together, our results indicated that natural variation of drought stress tolerance in bermudagrass varieties might be largely related to the induced changes of water status, osmolyte accumulation and antioxidant defense system.

Hydrolytic enzyme activity enhanced by Barium supplementation

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Camilo Muñoz

2016-10-01

Full Text Available Hydrolysis of polymers is a first and often limiting step during the degradation of plant residues. Plant biomass is generally a major component of waste residues and a major renewable resource to obtain a variety of secondary products including biofuels. Improving the performance of enzymatic hydrolysis of plant material with minimum costs and limiting the use of additional microbial biomass or hydrolytic enzymes directly influences competitiveness of these green biotechnological processes. In this study, we cloned and expressed a cellulase and two esterases recovered from environmental thermophilic soil bacterial communities and characterize their optimum activity conditions including the effect of several metal ions. Results showed that supplementing these hydrolytic reactions with Barium increases the activity of these extracellular hydrolytic enzymes. This observation represents a simple but major improvement to enhance the efficiency and competitiveness of this process within an increasingly important biotechnological sector.

Comparative studies focusing on transgenic through cp4EPSPS gene and non-transgenic soybean plants: an analysis of protein species and enzymes.

Science.gov (United States)

Arruda, Sandra C C; Barbosa, Herbert S; Azevedo, Ricardo A; Arruda, Marco A Z

2013-11-20

This work evaluates the activity of a few key enzymes involved in combating reactive oxygen species (ROS), such as ascorbate peroxidase (EC 1.11.1.11), catalase (EC 1.11.1.6), glutathione reductase (EC 1.6.4.2), and superoxide dismutase (EC 1.15.1.1), as well as the concentration of malondialdehyde and hydrogen peroxide in transgenic and non-transgenic soybean leaves. Additionally, differential protein species from leaves of both genotypes were evaluated by applying a regulation factor of ≥1.8 to further corroborate the hypothesis that genetic modification itself can be a stress factor for these plants. For this task, transgenic soybean plants were obtained from seeds modified with the cp4EPSPS gene. The results revealed higher activities of all evaluated enzymes in transgenic than in non-transgenic soybean leaves (ranging from 13.8 to 70.1%), as well as higher concentrations of malondialdehyde and hydrogen peroxide in transgenic soybean leaves, clearly indicating a condition of oxidative stress established in the transgenic genotype. Additionally, 47 proteins were differentially abundant when comparing the leaves of both plants, with 26 species accurately identified, including the protein involved in the genetic modification (CP4EPSPS). From these results, it is possible to conclude that the plant is searching for a new equilibrium to maintain its metabolism because the stress condition is being maintained within levels that can be tolerated by the plant. The present paper is the first one in the literature where are shown translational aspects involving plant stress and the genetic modification for soybean involving the cp4 EPSPS gene. The main biological importance of this work is to make possible the demystification of the genetic modification, allowing answers for some questions that still remain unknown, and enlarge our knowledge about genetically modified organisms. This article is part of a Special Issue entitled: Translational Plant Proteomics. Copyright

Purification, cloning, functional expression and characterization of perakine reductase: the first example from the AKR enzyme family, extending the alkaloidal network of the plant Rauvolfia.

Science.gov (United States)

Sun, Lianli; Ruppert, Martin; Sheludko, Yuri; Warzecha, Heribert; Zhao, Yu; Stöckigt, Joachim

2008-07-01

Perakine reductase (PR) catalyzes an NADPH-dependent step in a side-branch of the 10-step biosynthetic pathway of the alkaloid ajmaline. The enzyme was cloned by a "reverse-genetic" approach from cell suspension cultures of the plant Rauvolfia serpentina (Apocynaceae) and functionally expressed in Escherichia coli as the N-terminal His(6)-tagged protein. PR displays a broad substrate acceptance, converting 16 out of 28 tested compounds with reducible carbonyl function which belong to three substrate groups: benzaldehyde, cinnamic aldehyde derivatives and monoterpenoid indole alkaloids. The enzyme has an extraordinary selectivity in the group of alkaloids. Sequence alignments define PR as a new member of the aldo-keto reductase (AKR) super family, exhibiting the conserved catalytic tetrad Asp52, Tyr57, Lys84, His126. Site-directed mutagenesis of each of these functional residues to an alanine residue results in >97.8% loss of enzyme activity, in compounds of each substrate group. PR represents the first example of the large AKR-family which is involved in the biosynthesis of plant monoterpenoid indole alkaloids. In addition to a new esterase, PR significantly extends the Rauvolfia alkaloid network to the novel group of peraksine alkaloids.

The significance of cellulolytic enzymes produced by Trichoderma in opportunistic lifestyle of this fungus.

Science.gov (United States)

Strakowska, Judyta; Błaszczyk, Lidia; Chełkowski, Jerzy

2014-07-01

The degradation of native cellulose to glucose monomers is a complex process, which requires the synergistic action of the extracellular enzymes produced by cellulolytic microorganisms. Among fungi, the enzymatic systems that can degrade native cellulose have been extensively studied for species belonging to the genera of Trichoderma. The majority of the cellulolytic enzymes described so far have been examples of Trichoderma reesei, extremely specialized in the efficient degradation of plant cell wall cellulose. Other Trichoderma species, such as T. harzianum, T. koningii, T. longibrachiatum, and T. viride, known for their capacity to produce cellulolytic enzymes, have been isolated from various ecological niches, where they have proved successful in various heterotrophic interactions. As saprotrophs, these species are considered to make a contribution to the degradation of lignocellulosic plant material. Their cellulolytic potential is also used in interactions with plants, especially in plant root colonization. However, the role of cellulolytic enzymes in species forming endophytic associations with plants or in those existing in the substratum for mushroom cultivation remains unknown. The present review discusses the current state of knowledge about cellulolytic enzymes production by Trichoderma species and the encoding genes, as well as the involvement of these proteins in the lifestyle of Trichoderma. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Detection of methyl salicylate using bi-enzyme electrochemical sensor consisting salicylate hydroxylase and tyrosinase.

Science.gov (United States)

Fang, Yi; Bullock, Hannah; Lee, Sarah A; Sekar, Narendran; Eiteman, Mark A; Whitman, William B; Ramasamy, Ramaraja P

2016-11-15

Volatile organic compounds have been recognized as important marker chemicals to detect plant diseases caused by pathogens. Methyl salicylate has been identified as one of the most important volatile organic compounds released by plants during a biotic stress event such as fungal pathogen infection. Advanced detection of these marker chemicals could help in early identification of plant diseases and has huge significance for agricultural industry. This work describes the development of a novel bi-enzyme based electrochemical biosensor consisting of salicylate hydroxylase and tyrosinase enzymes immobilized on carbon nanotube modified electrodes. The amperometric detection using the bi-enzyme platform was realized through a series of cascade reactions that terminate in an electrochemical reduction reaction. Electrochemical measurements revealed that the sensitivity of the bi-enzyme sensor was 30.6±2.7µAcm(-2)µM(-1) and the limit of detection and limit of quantification were 13nM (1.80ppb) and 39nM (5.39ppb) respectively. Interference studies showed no significant interference from the other common plant volatile compounds. Synthetic analyte studies revealed that the bi-enzyme based biosensor can be used to reliably detect methyl salicylate released by unhealthy plants. Copyright © 2016. Published by Elsevier B.V.

Homology modelling and docking studies on Neuraminidase enzyme as a natural product target for combating influenza

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Nisha Singh

2017-10-01

Full Text Available Influenza remains to be dreadful with yearly epidemics and sudden pandemic outbreaks causing significant mortality, even in nations with the most advanced health care systems. Thus, there has been a long-standing interest to develop effective and safe antiviral agents to treat infected individuals. Attempt to identify suitable molecular targets as antiviral compounds have focused recently on the influenza virus neuraminidase (NA, a key enzyme in viral replication [1]. In this research, virtual screening was done on a total of 600 natural compounds from 22 ethno medicinal Indian herbs for activity against neuraminidase enzyme exploiting representative protein conformations selected from molecular dynamics simulations. Neuraminidase enzyme sequences from different existing strains available on National Center of Biotechnology Information [2] (NCBI protein database were aligned using Clustal W [3] and CLC workbench 10 [4] to find the conserved residues. Neuraminidase protein sequence from H1N1 strain available on NCBI was used to structure 3D target model predicted against dataset from Protein data bank using modeller [5]. The target model was validated on different parameter at SAVES Server [6]. Using this target model a pharmacophore model was developed using ligand based strategy exploiting the three known inhibitors. The docking parameters were validated by redocking Zanamivir to its co-complex 2009 H1N1 NA crystal structure (PDB ID: 3TI5 generating best pose with a RMSD value of 0.7543 A°. This model was then used for in silico analysis of a library of natural compounds from 22 ethno medicinal Indian herbs known to have antiviral activity taken downloaded from PubChem database and selected on the basis of drug likeliness. All the compounds were docked in the binding pocket of neuraminidase. Top compounds having binding affinity better than or comparable to the control drug Zanamivir were selected and analyzed for their ADME and toxicity

Plant growth and development vs. high and low levels of plant-beneficial heavy metal ions

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Namira Arif

2016-11-01

Full Text Available Heavy metals (HMs exists in the environment in both forms as essential and non-essential. These HM ions enter in soil biota from various sources like natural and anthropogenic. Essential HMs such as cobalt (Co, copper (Cu, iron (Fe, manganese (Mn, molybdenum (Mo, nickel (Ni, and zinc (Zn plays a beneficial role in plant growth and development. At optimum level these beneficial elements improves the plant’s nutritional level and also several mechanisms essential for the normal growth and better yield of plants. The range of their optimality for land plants is varied. Plant uptake heavy metals as a soluble component or solubilized them by root exudates. While their presence in excess become toxic for plants that switches the plant’s ability to uptake and accumulate other nonessential elements. The increased amount of HMs within the plant tissue displays direct and indirect toxic impacts. Such direct effects are the generation of oxidative stress which further aggravates inhibition of cytoplasmic enzymes and damage to cell structures. Although, indirect possession is the substitution of essential nutrients at plant’s cation exchange sites. These ions readily influence role of various enzymes and proteins, arrest metabolism, and reveal phytotoxicity. On account of recent advancements on beneficial HMs ions Co, Cu, Fe, Mn, Mo, Ni, and Zn in soil-plant system, the present paper: overview the sources of HMs in soils and their uptake and transportation mechanism, here we have discussed the role of metal transporters in transporting the essential metal ions from soil to plants. The role played by Co, Cu, Fe, Mn, Mo, Ni, and Zn at both low and high level on the plant growth and development and the mechanism to alleviate metal toxicity at high level have been also discussed. At the end, on concluding the article we have also discussed the future perspective in respect to beneficial HM ions interaction with plant at both levels.

Natural radioactivity in soil around Baoji coal-fired power plant

International Nuclear Information System (INIS)

Wang Lingqing; Lu Xinwei; Jia Xiaodan; Wang Fengling

2007-01-01

Based on systematic sampling of soil around the Baoji coal-fired power plant, the activity concentrations of the natural radionuclides 226 Ra, 232 Th and 40 K were determined using γ-ray spectrometry. Each eight soil samples were collected within the range of 1 km of the plant, and at a distance of 1 and 3 km from the plant, respectively. Two layers of soil sample [0-25cm(layer A), 25cm-50cm(layer B)] were collected at each location. The concentrations of these radionuclides are different horizontally and vertically. The measured specific activity of 226 Ra, 232 Th and 40 K were compared with the average activity of other cities in Shaanxi soil. The results show that 226 Ra concentrations in layer A were higher than those in layer B and concentrations of 232 Th and 40 K in layer B were greater than those in layer A in soil samples collected at 1 km. (authors)

The Natural Antimicrobial Enzyme Lysozyme is Up-Regulated in Gastrointestinal Inflammatory Conditions

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Carlos A. Rubio

2014-01-01

Full Text Available The cells that line the mucosa of the human gastrointestinal tract (GI, that is, oral cavity, oesophagus, stomach, small intestine, large intestine, and rectum are constantly challenged by adverse micro-environmental factors, such as different pH, enzymes, and bacterial flora. With exception of the oral cavity, these microenvironments also contain remnant cocktails of secreted enzymes and bacteria from upper organs along the tract. The density of the GI bacteria varies, from 103/mL near the gastric outlet, to 1010/mL at the ileocecal valve, to 1011 to 1012/mL in the colon. The total microbial population (ca. 1014 exceeds the total number of cells in the tract. It is, therefore, remarkable that despite the prima facie inauspicious mixture of harmful secretions and bacteria, the normal GI mucosa retains a healthy state of cell renewal. To counteract the hostile microenvironment, the GI epithelia react by speeding cell exfoliation (the GI mucosa has a turnover time of two to three days, by increasing peristalsis, by eliminating bacteria through secretion of plasma cell-immunoglobulins and by increasing production of natural antibacterial compounds, such as defensin-5 and lysozyme. Only recently, lysozyme was found up-regulated in Barrett’s oesophagitis, chronic gastritis, gluten-induced atrophic duodenitis (coeliac disease, collagenous colitis, lymphocytic colitis, and Crohn’s colitis. This up-regulation is a response directed to the special types of bacteria recently detected in these diseases. The aim of lysozyme up-regulation is to protect individual mucosal segments to chronic inflammation. The molecular mechanisms connected to the crosstalk between the intraluminal bacterial flora and the production of lysozyme released by the GI mucosae, are discussed. Bacterial resistance continues to exhaust our supply of commercial antibiotics. The potential use of lysozyme to treat infectious diseases is receiving much attention.

Ligninolytic enzyme activities in mycelium of some wild and ...

African Journals Online (AJOL)

Lignin is probably one of the most recalcitrant compounds synthesized by plants. This compound is degraded by few microorganisms. White-rot fungi have been extensively studied due to its powerful ligninolytic enzymes. In this study, ligninolytic enzyme activities of different fungal species (six commercial and 13 wild) were ...

Antiherbivore defenses alter natural selection on plant reproductive traits.

Science.gov (United States)

Thompson, Ken A; Johnson, Marc T J

2016-04-01

While many studies demonstrate that herbivores alter selection on plant reproductive traits, little is known about whether antiherbivore defenses affect selection on these traits. We hypothesized that antiherbivore defenses could alter selection on reproductive traits by altering trait expression through allocation trade-offs, or by altering interactions with mutualists and/or antagonists. To test our hypothesis, we used white clover, Trifolium repens, which has a Mendelian polymorphism for the production of hydrogen cyanide-a potent antiherbivore defense. We conducted a common garden experiment with 185 clonal families of T. repens that included cyanogenic and acyanogenic genotypes. We quantified resistance to herbivores, and selection on six floral traits and phenology via male and female fitness. Cyanogenesis reduced herbivory but did not alter the expression of reproductive traits through allocation trade-offs. However, the presence of cyanogenic defenses altered natural selection on petal morphology and the number of flowers within inflorescences via female fitness. Herbivory influenced selection on flowers and phenology via female fitness independently of cyanogenesis. Our results demonstrate that both herbivory and antiherbivore defenses alter natural selection on plant reproductive traits. We discuss the significance of these results for understanding how antiherbivore defenses interact with herbivores and pollinators to shape floral evolution. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

Natural variations and controlled changes in lignification process

Energy Technology Data Exchange (ETDEWEB)

Grand, C.; Boudet, A.M.; Ranjeva, R.

1982-10-01

Plant materials exhibit a great heterogeneity as far as the concentration and composition of lignins are concerned. Different examples of their natural variation, including taxonomic differences, developmental changes, mutations and responses to pathogen attack are presented. This variability suggests that lignin content and composition can be manipulated in plants, to a certain extent, by different treatments. Several possibilities are described to increase lignin concentrations. They mainly include hormonal or precursor treatments. Moreover light greatly affects the quantity and quality of lignins and such changes in environmental conditions can be used to produce specific radio-labelled lignins in view of biodegradation studies. Finally, induced mutants with modified lignins are described and attempts in inhibiting lignification through specific enzyme inhibitors are discussed. These data suggest that there is a good possibility of obtaining plants with modified lignins either genetically or by chemical inhibition. These strategies should be developed in the future in order to optimize plant biomass utilisation. (Refs. 44).

Response of antioxidant enzymes in Nicotiana tabacum clones during phytoextraction of heavy metals.

Science.gov (United States)

Lyubenova, Lyudmila; Nehnevajova, Erika; Herzig, Rolf; Schröder, Peter

2009-07-01

Tobacco, Nicotiana tabacum, is a widely used model plant for growth on heavy-metal-contaminated sites. Its high biomass and deep rooting system make it interesting for phytoextraction. In the present study, we investigated the antioxidative activities and glutathione-dependent enzymes of different tobacco clones optimized for better Cd and Zn accumulation in order to characterize their performance in the field. The improved heavy metal resistance also makes the investigated tobacco clones interesting for understanding the plant defense enzyme system in general. Freshly harvested plant material (N. tabacum leaves) was used to investigate the antioxidative cascade in plants grown on heavy metal contaminated sites with and without amendments of different ammonium nitrate and ammonium sulfate fertilizers. Plants were grown on heavily polluted soils in north-east Switzerland. Leaves were harvested at the field site and directly deep frozen in liquid N(2). Studies were concentrated on the antioxidative enzymes of the Halliwell-Asada cycle, and spectrophotometric measurements of catalase (CAT, EC 1.11.1.6), ascorbate peroxidase (APX, EC 1.11.1.11), superoxide dismutase (SOD, EC 1.15.1.1), glutathione peroxidase (GPX, EC 1.11.1.9), glutathione reductase (GR, EC 1.6.4.2), glutathione S-transferase (GST, EC 2.5.1.18) were performed. We tried to explain the relationship between fertilizer amendments and the activity of the enzymatic defense systems. When tobacco (N. tabacum) plants originating from different mutants were grown under field conditions with varying fertilizer application, the uptake of cadmium and zinc from soil increased with increasing biomass. Depending on Cd and Zn uptake, several antioxidant enzymes showed significantly different activities. Whereas SOD and CAT were usually elevated, several other enzymes, and isoforms of GST were strongly inhibited. Heavy metal uptake represents severe stress to plants, and specific antioxidative enzymes are induced at the

Effects of fluoride on germination, early growth and antioxidant enzyme activities of legume plant species Prosopis juliflora.

Science.gov (United States)

Saini, Poonam; Khan, Suphiya; Baunthiyal, Mamta; Sharma, Vinay

2013-03-01

Prosopis juliflora (Mimosoideae) is a fast growing and drought resistant tree of semi-arid region of India where fluoride (F) toxicity is a common problem. In the present investigations this species was fluoride tested to check their capacity as bioindicator plant and its efficiency to accumulate. To achieve this aim, P. juliflora seedlings grown in hydroponic culture containing different concentrations of F were analyzed for germination percentage together with some biochemical parameters viz, antioxidant enzyme activities, total chlorophyll and accumulation of F in different plant parts. After 15 days of treatment, root growth (r = -0.928, p juliflora did not show any morphological changes (marginal and tip chlorosis of leaf portions, necrosis and together these features are referred to as leaf "tip-burn") therefore, this species may be used as suitable bioindicator species for potentially F affected areas. Further, higher accumulation of F in roots indicates that P. juliflora is a suitable species for the removal of F in phytoremediation purposes.

Enzymes from Fungal and Plant Origin Required for Chemical Diversification of Insecticidal Loline Alkaloids in Grass-Epichloë Symbiota

Science.gov (United States)

Pan, Juan; Bhardwaj, Minakshi; Nagabhyru, Padmaja; Grossman, Robert B.; Schardl, Christopher L.

2014-01-01

The lolines are a class of bioprotective alkaloids that are produced by Epichloë species, fungal endophytes of grasses. These alkaloids are saturated 1-aminopyrrolizidines with a C2 to C7 ether bridge, and are structurally differentiated by the various modifications of the 1-amino group: -NH2 (norloline), -NHCH3 (loline), -N(CH3)2 (N-methylloline), -N(CH3)Ac (N-acetylloline), -NHAc (N-acetylnorloline), and -N(CH3)CHO (N-formylloline). Other than the LolP cytochrome P450, which is required for conversion of N-methylloline to N-formylloline, the enzymatic steps for loline diversification have not yet been established. Through isotopic labeling, we determined that N-acetylnorloline is the first fully cyclized loline alkaloid, implying that deacetylation, methylation, and acetylation steps are all involved in loline alkaloid diversification. Two genes of the loline alkaloid biosynthesis (LOL) gene cluster, lolN and lolM, were predicted to encode an N-acetamidase (deacetylase) and a methyltransferase, respectively. A knockout strain lacking both lolN and lolM stopped the biosynthesis at N-acetylnorloline, and complementation with the two wild-type genes restored production of N-formylloline and N-acetylloline. These results indicated that lolN and lolM are required in the steps from N-acetylnorloline to other lolines. The function of LolM as an N-methyltransferase was confirmed by its heterologous expression in yeast resulting in conversion of norloline to loline, and of loline to N-methylloline. One of the more abundant lolines, N-acetylloline, was observed in some but not all plants with symbiotic Epichloë siegelii, and when provided with exogenous loline, asymbiotic meadow fescue (Lolium pratense) plants produced N-acetylloline, suggesting that a plant acetyltransferase catalyzes N-acetylloline formation. We conclude that although most loline alkaloid biosynthesis reactions are catalyzed by fungal enzymes, both fungal and plant enzymes are responsible for the

Enzymes from fungal and plant origin required for chemical diversification of insecticidal loline alkaloids in grass-Epichloë symbiota.

Science.gov (United States)

Pan, Juan; Bhardwaj, Minakshi; Nagabhyru, Padmaja; Grossman, Robert B; Schardl, Christopher L

2014-01-01

The lolines are a class of bioprotective alkaloids that are produced by Epichloë species, fungal endophytes of grasses. These alkaloids are saturated 1-aminopyrrolizidines with a C2 to C7 ether bridge, and are structurally differentiated by the various modifications of the 1-amino group: -NH2 (norloline), -NHCH3 (loline), -N(CH3)2 (N-methylloline), -N(CH3)Ac (N-acetylloline), -NHAc (N-acetylnorloline), and -N(CH3)CHO (N-formylloline). Other than the LolP cytochrome P450, which is required for conversion of N-methylloline to N-formylloline, the enzymatic steps for loline diversification have not yet been established. Through isotopic labeling, we determined that N-acetylnorloline is the first fully cyclized loline alkaloid, implying that deacetylation, methylation, and acetylation steps are all involved in loline alkaloid diversification. Two genes of the loline alkaloid biosynthesis (LOL) gene cluster, lolN and lolM, were predicted to encode an N-acetamidase (deacetylase) and a methyltransferase, respectively. A knockout strain lacking both lolN and lolM stopped the biosynthesis at N-acetylnorloline, and complementation with the two wild-type genes restored production of N-formylloline and N-acetylloline. These results indicated that lolN and lolM are required in the steps from N-acetylnorloline to other lolines. The function of LolM as an N-methyltransferase was confirmed by its heterologous expression in yeast resulting in conversion of norloline to loline, and of loline to N-methylloline. One of the more abundant lolines, N-acetylloline, was observed in some but not all plants with symbiotic Epichloë siegelii, and when provided with exogenous loline, asymbiotic meadow fescue (Lolium pratense) plants produced N-acetylloline, suggesting that a plant acetyltransferase catalyzes N-acetylloline formation. We conclude that although most loline alkaloid biosynthesis reactions are catalyzed by fungal enzymes, both fungal and plant enzymes are responsible for the

Enzymes from fungal and plant origin required for chemical diversification of insecticidal loline alkaloids in grass-Epichloë symbiota.

Directory of Open Access Journals (Sweden)

Juan Pan

Full Text Available The lolines are a class of bioprotective alkaloids that are produced by Epichloë species, fungal endophytes of grasses. These alkaloids are saturated 1-aminopyrrolizidines with a C2 to C7 ether bridge, and are structurally differentiated by the various modifications of the 1-amino group: -NH2 (norloline, -NHCH3 (loline, -N(CH32 (N-methylloline, -N(CH3Ac (N-acetylloline, -NHAc (N-acetylnorloline, and -N(CH3CHO (N-formylloline. Other than the LolP cytochrome P450, which is required for conversion of N-methylloline to N-formylloline, the enzymatic steps for loline diversification have not yet been established. Through isotopic labeling, we determined that N-acetylnorloline is the first fully cyclized loline alkaloid, implying that deacetylation, methylation, and acetylation steps are all involved in loline alkaloid diversification. Two genes of the loline alkaloid biosynthesis (LOL gene cluster, lolN and lolM, were predicted to encode an N-acetamidase (deacetylase and a methyltransferase, respectively. A knockout strain lacking both lolN and lolM stopped the biosynthesis at N-acetylnorloline, and complementation with the two wild-type genes restored production of N-formylloline and N-acetylloline. These results indicated that lolN and lolM are required in the steps from N-acetylnorloline to other lolines. The function of LolM as an N-methyltransferase was confirmed by its heterologous expression in yeast resulting in conversion of norloline to loline, and of loline to N-methylloline. One of the more abundant lolines, N-acetylloline, was observed in some but not all plants with symbiotic Epichloë siegelii, and when provided with exogenous loline, asymbiotic meadow fescue (Lolium pratense plants produced N-acetylloline, suggesting that a plant acetyltransferase catalyzes N-acetylloline formation. We conclude that although most loline alkaloid biosynthesis reactions are catalyzed by fungal enzymes, both fungal and plant enzymes are responsible for

Relating Nanoscale Accessibility within Plant Cell Walls to Improved Enzyme Hydrolysis Yields in Corn Stover Subjected to Diverse Pretreatments.

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Crowe, Jacob D; Zarger, Rachael A; Hodge, David B

2017-10-04

Simultaneous chemical modification and physical reorganization of plant cell walls via alkaline hydrogen peroxide or liquid hot water pretreatment can alter cell wall structural properties impacting nanoscale porosity. Nanoscale porosity was characterized using solute exclusion to assess accessible pore volumes, water retention value as a proxy for accessible water-cell walls surface area, and solute-induced cell wall swelling to measure cell wall rigidity. Key findings concluded that delignification by alkaline hydrogen peroxide pretreatment decreased cell wall rigidity and that the subsequent cell wall swelling resulted increased nanoscale porosity and improved enzyme binding and hydrolysis compared to limited swelling and increased accessible surface areas observed in liquid hot water pretreated biomass. The volume accessible to a 90 Å dextran probe within the cell wall was found to be correlated to both enzyme binding and glucose hydrolysis yields, indicating cell wall porosity is a key contributor to effective hydrolysis yields.

The Action of Antidiabetic Plants of the Canadian James Bay Cree Traditional Pharmacopeia on Key Enzymes of Hepatic Glucose Homeostasis

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Abir Nachar

2013-01-01

Full Text Available We determined the capacity of putative antidiabetic plants used by the Eastern James Bay Cree (Canada to modulate key enzymes of gluconeogenesis and glycogen synthesis and key regulating kinases. Glucose-6-phosphatase (G6Pase and glycogen synthase (GS activities were assessed in cultured hepatocytes treated with crude extracts of seventeen plant species. Phosphorylation of AMP-dependent protein kinase (AMPK, Akt, and Glycogen synthase kinase-3 (GSK-3 were probed by Western blot. Seven of the seventeen plant extracts significantly decreased G6Pase activity, Abies balsamea and Picea glauca, exerting an effect similar to insulin. This action involved both Akt and AMPK phosphorylation. On the other hand, several plant extracts activated GS, Larix laricina and A. balsamea, far exceeding the action of insulin. We also found a significant correlation between GS stimulation and GSK-3 phosphorylation induced by plant extract treatments. In summary, three Cree plants stand out for marked effects on hepatic glucose homeostasis. P. glauca affects glucose production whereas L. laricina rather acts on glucose storage. However, A. balsamea has the most promising profile, simultaneously and powerfully reducing G6Pase and stimulating GS. Our studies thus confirm that the reduction of hepatic glucose production likely contributes to the therapeutic potential of several antidiabetic Cree traditional medicines.

How Do Enzymes 'Meet' Nanoparticles and Nanomaterials?

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Chen, Ming; Zeng, Guangming; Xu, Piao; Lai, Cui; Tang, Lin

2017-11-01

Enzymes are fundamental biological catalysts responsible for biological regulation and metabolism. The opportunity for enzymes to 'meet' nanoparticles and nanomaterials is rapidly increasing due to growing demands for applications in nanomaterial design, environmental monitoring, biochemical engineering, and biomedicine. Therefore, understanding the nature of nanomaterial-enzyme interactions is becoming important. Since 2014, enzymes have been used to modify, degrade, or make nanoparticles/nanomaterials, while numerous nanoparticles/nanomaterials have been used as materials for enzymatic immobilization and biosensors and as enzyme mimicry. Among the various nanoparticles and nanomaterials, metal nanoparticles and carbon nanomaterials have received extensive attention due to their fascinating properties. This review provides an overview about how enzymes meet nanoparticles and nanomaterials. Copyright © 2017 Elsevier Ltd. All rights reserved.

Novel fermentation processes for manufacturing plant natural products.

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Zhou, Jingwen; Du, Guocheng; Chen, Jian

2014-02-01

Microbial production of plant natural products (PNPs), such as terpenoids, flavonoids from renewable carbohydrate feedstocks offers sustainable and economically attractive alternatives to their petroleum-based production. Rapid development of metabolic engineering and synthetic biology of microorganisms shows many advantages to replace the current extraction of these useful high price chemicals from plants. Although few of them were actually applied on a large scale for PNPs production, continuous research on these high-price chemicals and the rapid growing global market of them, show the promising future for the production of these PNPs by microorganisms with a more economic and environmental friendly way. Introduction of novel pathways and optimization of the native cellular processes by metabolic engineering of microorganisms for PNPs production are rapidly expanding its range of cell-factory applications. Here we review recent progress in metabolic engineering of microorganisms for the production of PNPs. Besides, factors restricting the yield improvement and application of lab-scale achievements to industrial applications have also been discussed. Copyright © 2013 Elsevier Ltd. All rights reserved.

Microbial genetic engineering and enzyme technology

Energy Technology Data Exchange (ETDEWEB)

Hollenberg, C.P.; Sahm, H.

1987-01-01

In a series of up-to-date contributions BIOTEC 1 has experts discussing the current topics in microbial gene technology and enzyme technology and speculating on future developments. Bacterial and yeast systems for the production of interferons, growth hormone or viral antigenes are described as well as the impact of gene technology on plants. Exciting is the prospect of degrading toxic compounds in our environment by microorganisms tuned in the laboratory. Enzymes are the most effective catalysts we know. They exhibit a very high substrate- and stereospecificity. These properties make enzymes extremely attractive as industrial catalysts, leading to new production processes that are non-polluting and save both energy and raw materials. (orig.) With 135 figs., 36 tabs.

Podophyllotoxin: a novel potential natural anticancer agent

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Hamidreza Ardalani

2017-06-01

Full Text Available Objective: The aim of the present review is to give an overview about the role, biosynthesis, and characteristics of Podophyllotoxin (PTOX as a potential antitumor agent with particular emphasis on key biosynthesis processes, function of related enzymes and characterization of genes encoding the enzymes. Materials and Methods: Google scholar, PubMed and Scopus were searched for literatures which have studied identification, characterization, fermentation and therapeutic effects of PTOX and published in English language until end of 2016. Results: PTOX is an important plant-derived natural product, has derivatives such as etoposide and teniposide, which have been used as therapies for cancers and venereal wart. PTOX structure is closely related to the aryltetralin lactone lignans that have antineoplastic and antiviral activities. Podophyllum emodi Wall. (syn. P. hexandrum and Podophyllum peltatum L. (Berberidaceae are the major sources of PTOX. It has been shown that ferulic acid and methylenedioxy substituted cinnamic acid are the enzymes involved in PTOX synthesis. PTOX prevents cell growth via polymerization of tubulin, leading to cell cycle arrest and suppression of the formation of the mitotic-spindles microtubules.   Conclusion: Several investigations have been performed in biosynthesis of PTOX such as cultivation of these plants, though they were unsuccessful. Thus, it is important to find alternative sources to satisfy the pharmaceutical demand for PTOX. Moreover, further preclinical studies are warranted to explore the molecular mechanisms of these agents in treatment of cancer and their possible potential to overcome chemoresistance of tumor cells.

Podophyllotoxin: a novel potential natural anticancer agent

Science.gov (United States)

Ardalani, Hamidreza; Avan, Amir; Ghayour-Mobarhan, Majid

2017-01-01

Objective: The aim of the present review is to give an overview about the role, biosynthesis, and characteristics of Podophyllotoxin (PTOX) as a potential antitumor agent with particular emphasis on key biosynthesis processes, function of related enzymes and characterization of genes encoding the enzymes. Materials and Methods: Google scholar, PubMed and Scopus were searched for literatures which have studied identification, characterization, fermentation and therapeutic effects of PTOX and published in English language until end of 2016. Results: PTOX is an important plant-derived natural product, has derivatives such as etoposide and teniposide, which have been used as therapies for cancers and venereal wart. PTOX structure is closely related to the aryltetralin lactone lignans that have antineoplastic and antiviral activities. Podophyllum emodi Wall. (syn. P. hexandrum) and Podophyllum peltatum L. (Berberidaceae) are the major sources of PTOX. It has been shown that ferulic acid and methylenedioxy substituted cinnamic acid are the enzymes involved in PTOX synthesis. PTOX prevents cell growth via polymerization of tubulin, leading to cell cycle arrest and suppression of the formation of the mitotic-spindles microtubules. Conclusion: Several investigations have been performed in biosynthesis of PTOX such as cultivation of these plants, though they were unsuccessful. Thus, it is important to find alternative sources to satisfy the pharmaceutical demand for PTOX. Moreover, further preclinical studies are warranted to explore the molecular mechanisms of these agents in treatment of cancer and their possible potential to overcome chemoresistance of tumor cells. PMID:28884079

Trait differences between naturalized and invasive plant species independent of residence time and phylogeny.

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Gallagher, R V; Randall, R P; Leishman, M R

2015-04-01

The ability to predict which alien plants will transition from naturalized to invasive prior to their introduction to novel regions is a key goal for conservation and has the potential to increase the efficacy of weed risk assessment (WRA). However, multiple factors contribute to plant invasion success (e.g., functional traits, range characteristics, residence time, phylogeny), and they all must be taken into account simultaneously in order to identify meaningful correlates of invasion success. We compiled 146 pairs of phylogenetically paired (congeneric) naturalized and invasive plant species in Australia with similar minimum residence times (i.e., time since introduction in years). These pairs were used to test for differences in 5 functional traits (flowering duration, leaf size, maximum height, specific leaf area [SLA], seed mass) and 3 characteristics of species' native ranges (biome occupancy, mean annual temperature, and rainfall breadth) between naturalized and invasive species. Invasive species, on average, had larger SLA, longer flowering periods, and were taller than their congeneric naturalized relatives. Invaders also exhibited greater tolerance for different environmental conditions in the native range, where they occupied more biomes and a wider breadth of rainfall and temperature conditions than naturalized congeners. However, neither seed mass nor leaf size differed between pairs of naturalized and invasive species. A key finding was the role of SLA in distinguishing between naturalized and invasive pairs. Species with high SLA values were typically associated with faster growth rates, more rapid turnover of leaf material, and shorter lifespans than those species with low SLA. This suite of characteristics may contribute to the ability of a species to transition from naturalized to invasive across a wide range of environmental contexts and disturbance regimes. Our findings will help in the refinement of WRA protocols, and we advocate the inclusion

Economic and Environmental Assessment of Natural Gas Plants with Carbon Capture and Storage (NGCC-CCS)

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The CO2 intensity of electricity produced by state-of-the-art natural gas combined-cycle turbines (NGCC) isapproximately one-third that of the U.S. fleet of existing coal plants. Compared to new nuclear plants and coal plantswith integrated carbon capture, NGCC has a lower invest...

Natural radionuclides in waste water discharged from coal-fired power plants in Serbia.

Science.gov (United States)

Janković, Marija M; Todorović, Dragana J; Sarap, Nataša B; Krneta Nikolić, Jelena D; Rajačić, Milica M; Pantelić, Gordana K

2016-12-01

Investigation of the natural radioactivity levels in water around power plants, as well as in plants, coal, ash, slag and soil, and to assess the associated radiation hazard is becoming an emerging and interesting topic. This paper is focused on the results of the radioactivity analysis in waste water samples from five coal-fired power plants in Serbia (Nikola Tesla A, Nikola Tesla B, Kolubara, Morava and Kostolac), which were analyzed in the period 2003-2015. River water samples taken upstream and downstream from the power plants, drain water and overflow water were analyzed. In the water samples gamma spectrometry analysis was performed as well as determination of gross alpha and beta activity. Natural radionuclide 40 K was detected by gamma spectrometry, while the concentrations of other radionuclides, 226 Ra, 235 U and 238 U, usually were below the minimum detection activity (MDA). 232 Th and artificial radionuclide 137 Cs were not detected in these samples. Gross alpha and beta activities were determined by the α/β low level proportional counter Thermo Eberline FHT 770 T. In the analyzed samples, gross alpha activity ranged from MDA to 0.47 Bq L - 1 , while the gross beta activity ranged from MDA to 1.55 Bq L - 1 .

Plant-bacteria partnership: phytoremediation of hydrocarbons contaminated soil and expression of catabolic genes

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Hamna Saleem

2016-01-01

Full Text Available Petroleum hydrocarbons are harmful to living organisms when they are exposed in natural environment. Once they come in contact, it is not an easy to remove them because many of their constituents are persistent in nature. To achieve this target, different approaches have been exploited by using plants, bacteria, and plant-bacteria together. Among them, combined use of plants and bacteria has gained tremendous attention as bacteria possess set of catabolic genes which produce catabolic enzymes to decontaminate hydrocarbons. In return, plant ooze out root exudates containing nutrients and necessary metabolites which facilitate the microbial colonization in plant rhizosphere. This results into high gene abundance and gene expression in the rhizosphere and, thus, leads to enhanced degradation. Moreover, high proportions of beneficial bacteria helps plant to gain more biomass due to their plant growth promoting activities and production of phytohromones. This review focuses functioning and mechanisms of catabolic genes responsible for degradation of straight chain and aromatic hydrocarbons with their potential of degradation in bioremediation. With the understanding of expression mechanisms, rate of degradation can be enhanced by adjusting environmental factors and acclimatizing plant associated bacteria in plant rhizosphere.

Enzyme mediated synthesis of polypyrrole in the presence of chondroitin sulfate and redox mediators of natural origin

International Nuclear Information System (INIS)

Grijalva-Bustamante, G.A.; Evans-Villegas, A.G.; Castillo-Castro, T. del; Castillo-Ortega, M.M.; Cruz-Silva, R.; Huerta, F.; Morallón, E.

2016-01-01

Polypyrrole (PPy) was synthesized by enzyme mediated oxidation of pyrrole using naturally occurring compounds as redox mediators. The catalytic mechanism is an enzymatic cascade reaction in which hydrogen peroxide is the oxidizer and soybean peroxidase, in the presence of acetosyringone, syringaldehyde or vanillin, acts as a natural catalysts. The effect of the initial reaction composition on the polymerization yield and electrical conductivity of PPy was analyzed. Morphology of the PPy particles was studied by scanning electron microscopy and transmission electron microscopy whereas the chemical structure was studied by X-ray photoelectron and Fourier transformed infrared spectroscopic techniques. The redox mediators increased the polymerization yield without a significant modification of the electronic structure of PPy. The highest conductivity of PPy was reached when chondroitin sulfate was used simultaneously as dopant and template during pyrrole polymerization. Electroactive properties of PPy obtained from natural precursors were successfully used in the amperometric quantification of uric acid concentrations. PPy increases the amperometric sensitivity of carbon nanotube screen-printed electrodes toward uric acid detection. - Highlights: • A new method of pyrrole polymerization using naturally occurring redox mediators and doping agents was studied. • The catalytic efficiency of different redox mediators toward pyrrole oxidation was evaluated. • Two different naturally occurring polymers were studied as bifunctional steric stabilizer/doping agents. • Polypyrrole improves the amperometric response of carbon nanotube screen printed electrodes toward uric acid sensing.

Enzyme mediated synthesis of polypyrrole in the presence of chondroitin sulfate and redox mediators of natural origin

Energy Technology Data Exchange (ETDEWEB)

Grijalva-Bustamante, G.A. [Departamento de Investigación en Polímeros y Materiales, Universidad de Sonora, CP 83000 Hermosillo, Sonora (Mexico); Evans-Villegas, A.G. [Departamento de Ciencias Químico Biológicas, Universidad de Sonora, CP 83000 Hermosillo, Sonora (Mexico); Castillo-Castro, T. del, E-mail: terecat@polimeros.uson.mx [Departamento de Investigación en Polímeros y Materiales, Universidad de Sonora, CP 83000 Hermosillo, Sonora (Mexico); Castillo-Ortega, M.M. [Departamento de Investigación en Polímeros y Materiales, Universidad de Sonora, CP 83000 Hermosillo, Sonora (Mexico); Cruz-Silva, R. [Research Center for Exotic Nanocarbons, Shinshu University, 4-17-1 Wakasato, 380-8553, Nagano (Japan); Huerta, F. [Departamento Ingeniería Textil y Papelera, Universitat Politecnica de Valencia, Plaza Ferrandiz y Carbonell, 1, E-03801 Alcoy (Spain); Morallón, E. [Departamento Química Física e Instituto Universitario de Materiales, Universidad de Alicante, Ap. 99, E-03080 Alicante (Spain)

2016-06-01

Polypyrrole (PPy) was synthesized by enzyme mediated oxidation of pyrrole using naturally occurring compounds as redox mediators. The catalytic mechanism is an enzymatic cascade reaction in which hydrogen peroxide is the oxidizer and soybean peroxidase, in the presence of acetosyringone, syringaldehyde or vanillin, acts as a natural catalysts. The effect of the initial reaction composition on the polymerization yield and electrical conductivity of PPy was analyzed. Morphology of the PPy particles was studied by scanning electron microscopy and transmission electron microscopy whereas the chemical structure was studied by X-ray photoelectron and Fourier transformed infrared spectroscopic techniques. The redox mediators increased the polymerization yield without a significant modification of the electronic structure of PPy. The highest conductivity of PPy was reached when chondroitin sulfate was used simultaneously as dopant and template during pyrrole polymerization. Electroactive properties of PPy obtained from natural precursors were successfully used in the amperometric quantification of uric acid concentrations. PPy increases the amperometric sensitivity of carbon nanotube screen-printed electrodes toward uric acid detection. - Highlights: • A new method of pyrrole polymerization using naturally occurring redox mediators and doping agents was studied. • The catalytic efficiency of different redox mediators toward pyrrole oxidation was evaluated. • Two different naturally occurring polymers were studied as bifunctional steric stabilizer/doping agents. • Polypyrrole improves the amperometric response of carbon nanotube screen printed electrodes toward uric acid sensing.

Measurents of natural radioactivity in an underground hydroelectric power plant

International Nuclear Information System (INIS)

Malvicini, Andrea; Esposito, PierLuigi; Depiesse, Danielle

2008-01-01

In underground working places, especially when ventilation is not properly regulated, large amounts of natural radioactivity can be found. This can give rise to potential exposures of non-negligible magnitude. Direct measurements of gamma radiation and radon were carried out during excavation works for the construction of an hydroelectric plant in the north of Italy. After the construction of the plant, in order to reduce radon concentrations and to improve ventilation effectiveness, the main entry gate was motorized and automated. Then, in order to find the optimal speed for the fans located in the galleries and in the power plant, radon and airflow velocity were measured. Correlation data between airflow and radon concentrations were found. An automatic regulation system has been set up using air velocity detectors and slightly modifying the software for the control and regulation of the power plant. Measurements must be made in order to identify radon sources and evaluate quantitative contributions as a function of ventilation. Underground hydroelectric plants are provided with entry galleries as well as secondary galleries from which radon coming out from the soil and the walls can exhale in quantities that depend on the contents of 226 Ra in the rocks and in the building materials. Other radon sources are the water coming out from the walls of the galleries and the water in the deep well located at the bottom of the power plant. Geological studies and mathematical models are useful means for the analysis of the relative contributions of the main sources as well as for the prediction of the effects deriving from modifications of the hydroelectric plant ventilation system or resulting from other important structural changes. (author)

Natural circulation in water cooled nuclear power plants: Phenomena, models, and methodology for system reliability assessments

International Nuclear Information System (INIS)

2005-11-01

In recent years it has been recognized that the application of passive safety systems (i.e. those whose operation takes advantage of natural forces such as convection and gravity), can contribute to simplification and potentially to improved economics of new nuclear power plant designs. Further, the IAEA Conference on The Safety of Nuclear Power: Strategy for the Future which was convened in 1991 noted that for new plants 'the use of passive safety features is a desirable method of achieving simplification and increasing the reliability of the performance of essential safety functions, and should be used wherever appropriate'. Considering the weak driving forces of passive systems based on natural circulation, careful design and analysis methods must be employed to assure that the systems perform their intended functions. To support the development of advanced water cooled reactor designs with passive systems, investigations of natural circulation are an ongoing activity in several IAEA Member States. Some new designs also utilize natural circulation as a means to remove core power during normal operation. In response to the motivating factors discussed above, and to foster international collaboration on the enabling technology of passive systems that utilize natural circulation, an IAEA Coordinated Research Project (CRP) on Natural Circulation Phenomena, Modelling and Reliability of Passive Systems that Utilize Natural Circulation was started in early 2004. Building on the shared expertise within the CRP, this publication presents extensive information on natural circulation phenomena, models, predictive tools and experiments that currently support design and analyses of natural circulation systems and highlights areas where additional research is needed. Therefore, this publication serves both to provide a description of the present state of knowledge on natural circulation in water cooled nuclear power plants and to guide the planning and conduct of the CRP in

Radiation hormesis in plant

International Nuclear Information System (INIS)

Kim, Jae Sung; Song, Hi Sup; Lee, Young Keun; Cun, Ki Jung; Shin, In Chul; Lim, Young Taek

1999-04-01

This research was performed to investigate the effects of low dose γ-ray radiation on the seed germination and the following physiological responses in vegetable crops. Special attention was focused on whether the resistance of vegetables against the unfavorable conditions of environment such as acid rain or soil types could be enhanced as an aspect of radiation hormesis. Analysis and characterization of antioxidant enzyme from plant culture cells and radiation tolerant of transformed plants from antioxidant enzyme (POD) were accomplished in the plant irradiated with difference dosage of γ-ray

Radiation hormesis in plant

Energy Technology Data Exchange (ETDEWEB)

Kim, Jae Sung; Song, Hi Sup; Lee, Young Keun; Cun, Ki Jung; Shin, In Chul; Lim, Young Taek

1999-04-01

This research was performed to investigate the effects of low dose {gamma}-ray radiation on the seed germination and the following physiological responses in vegetable crops. Special attention was focused on whether the resistance of vegetables against the unfavorable conditions of environment such as acid rain or soil types could be enhanced as an aspect of radiation hormesis. Analysis and characterization of antioxidant enzyme from plant culture cells and radiation tolerant of transformed plants from antioxidant enzyme (POD) were accomplished in the plant irradiated with difference dosage of {gamma}-ray.

Effect of single and binary combinations of plant-derived molluscicides on different enzyme activities in the nervous tissue of Achatina fulica.

Science.gov (United States)

Rao, I G; Singh, Amrita; Singh, V K; Singh, D K

2003-01-01

Effect of single and binary treatments of plant-derived molluscicides on different enzymes--acetylcholinesterase (AChE), lactic dehydrogenase (LDH) and acid/alkaline phosphatase (ACP/ALP)--in the nervous tissue of the harmful terrestrial snail Achatina fulica were studied. Sublethal in vivo 24-h exposure to 40% and 80% LC(50) of Azadirachta indica oil, Cedrus deodara oil, Allium sativum bulb powder, Nerium indicum bark powder and binary combinations of A. sativum (AS) + C. deodara (CD) and CD + A. indica (AI) oils significantly altered the activity of these enzymes in the nervous tissue of Achatina fulica. The binary treatment of AS + CD was more effective against AChE, LDH, and ALP than the single ones. However, binary treatment of AI + CD was more effective against ALP. Copyright 2003 John Wiley & Sons, Ltd.

Watching Individual Enzymes at Work

Science.gov (United States)

Blank, Kerstin; Rocha, Susana; De Cremer, Gert; Roeffaers, Maarten B. J.; Uji-i, Hiroshi; Hofkens, Johan