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Sample records for acid accumulation limits

  1. Investigation of fatty acid accumulation in the engineered Saccharomyces cerevisiae under nitrogen limited culture condition.

    Tang, Xiaoling; Chen, Wei Ning

    2014-06-01

    In this study, the Saccharomyces cerevisiae wild type strain and engineered strain with an overexpressed heterologous ATP-citrate lyase (acl) were cultured in medium with different carbon and nitrogen concentrations, and their fatty acid production levels were investigated. The results showed that when the S. cerevisiae engineered strain was cultivated under nitrogen limited culture condition, the yield of mono-unsaturated fatty acids showed higher than that under non-nitrogen limited condition; with the carbon concentration increased, the accumulation become more apparent, whereas in the wild type strain, no such correlation was found. Besides, the citrate level in the S. cerevisiae under nitrogen limited condition was found to be much higher than that under non-nitrogen limited condition, which indicated a relationship between the diminution of nitrogen and accumulation of citrate in the S. cerevisiae. The accumulated citrate could be further cleaved by acl to provide substrate for fatty acid synthesis. PMID:24755317

  2. Supply of fatty acid is one limiting factor in the accumulation of triacylglycerol in developing embryos

    Bao, X.; Ohlrogge, J.

    1999-08-01

    The metabolic factors that determine oil yield in seeds are still not well understood. To begin to examine the limits on triacylglycerol (TAG) production, developing Cuphea lanceolata, Ulmus carpinifolia, and Ulmus parvifolia embryos were incubated with factors whose availability might limit oil accumulation. The addition of glycerol or sucrose did not significantly influence the rate of TAG synthesis. However, the rate of {sup 14}C-TAG synthesis upon addition of 2.1 mM {sup 14}C-decanoic acid (10:0) was approximately four times higher than the in vivo rate of TAG accumulation in C. lanceolata and two times higher than the in vivo rate in U. carpinifolia and U. parvifolia. In C. lanceolata embryos, the highest rate of {sup 14}C-TAG synthesis (14.3 nmol h{sup {minus}1} embryo {sup {minus}1}) was achieved with the addition of 3.6 mM decanoic acid. {sup 14}C-Decanoic acid was incorporated equally well in all three acyl positions of TAG. The results suggest that C. lancelata, U. Carpinifolia, and U. parvifolia embryos have sufficient acyltransferase activities and glycerol-3-phosphate levels to support rates of TAG synthesis in excess of those found in vivo. Consequently, the amount of TAG synthesized in these oilseeds may be in part determined by the amount of fatty acid produced in plastids.

  3. Combined nitrogen limitation and cadmium stress stimulate total carbohydrates, lipids, protein and amino acid accumulation in Chlorella vulgaris (Trebouxiophyceae)

    Chia, Mathias Ahii, E-mail: chia28us@yahoo.com [Department of Botany, Federal University of São Carlos, Rodovia Washington Luis km 235, São Carlos, SP Cep 13565905 (Brazil); Lombardi, Ana Teresa [Department of Botany, Federal University of São Carlos, Rodovia Washington Luis km 235, São Carlos, SP Cep 13565905 (Brazil); Graça Gama Melão, Maria da [Department of Hydrobiology, Federal University of São Carlos, Rodovia Washington Luis km 235, São Carlos, SP Cep 13565905 (Brazil); Parrish, Christopher C. [Department of Ocean Sciences, Memorial University of Newfoundland, St. John’s, Newfoundland A1C 5S7 (Canada)

    2015-03-15

    Highlights: • Chlorella vulgaris was exposed to Cd under varying N concentrations. • Growth rate and cell density decreased with increasing Cd stress and N limitation. • Dry weight, chlorophyll a, total lipid, carbohydrate and protein were accumulated. • Amino acids like proline and glutamine were accumulated under N and Cd stress. • Changes in amino acid composition are sensitive biomarkers for Cd and N stress. - Abstract: Metals have interactive effects on the uptake and metabolism of nutrients in microalgae. However, the effect of trace metal toxicity on amino acid composition of Chlorella vulgaris as a function of varying nitrogen concentrations is not known. In this research, C. vulgaris was used to investigate the influence of cadmium (10{sup −7} and 2.0 × 10{sup −8} mol L{sup −1} Cd) under varying nitrogen (2.9 × 10{sup −6}, 1.1 × 10{sup −5} and 1.1 × 10{sup −3} mol L{sup −1} N) concentrations on its growth rate, biomass and biochemical composition. Total carbohydrates, total proteins, total lipids, as well as individual amino acid proportions were determined. The combination of Cd stress and N limitation significantly inhibited growth rate and cell density of C. vulgaris. However, increasing N limitation and Cd stress stimulated higher dry weight and chlorophyll a production per cell. Furthermore, biomolecules like total proteins, carbohydrates and lipids increased with increasing N limitation and Cd stress. Ketogenic and glucogenic amino acids were accumulated under the stress conditions investigated in the present study. Amino acids involved in metal chelation like proline, histidine and glutamine were significantly increased after exposure to combined Cd stress and N limitation. We conclude that N limitation and Cd stress affects the physiology of C. vulgaris by not only decreasing its growth but also stimulating biomolecule production.

  4. Combined nitrogen limitation and cadmium stress stimulate total carbohydrates, lipids, protein and amino acid accumulation in Chlorella vulgaris (Trebouxiophyceae)

    Highlights: • Chlorella vulgaris was exposed to Cd under varying N concentrations. • Growth rate and cell density decreased with increasing Cd stress and N limitation. • Dry weight, chlorophyll a, total lipid, carbohydrate and protein were accumulated. • Amino acids like proline and glutamine were accumulated under N and Cd stress. • Changes in amino acid composition are sensitive biomarkers for Cd and N stress. - Abstract: Metals have interactive effects on the uptake and metabolism of nutrients in microalgae. However, the effect of trace metal toxicity on amino acid composition of Chlorella vulgaris as a function of varying nitrogen concentrations is not known. In this research, C. vulgaris was used to investigate the influence of cadmium (10−7 and 2.0 × 10−8 mol L−1 Cd) under varying nitrogen (2.9 × 10−6, 1.1 × 10−5 and 1.1 × 10−3 mol L−1 N) concentrations on its growth rate, biomass and biochemical composition. Total carbohydrates, total proteins, total lipids, as well as individual amino acid proportions were determined. The combination of Cd stress and N limitation significantly inhibited growth rate and cell density of C. vulgaris. However, increasing N limitation and Cd stress stimulated higher dry weight and chlorophyll a production per cell. Furthermore, biomolecules like total proteins, carbohydrates and lipids increased with increasing N limitation and Cd stress. Ketogenic and glucogenic amino acids were accumulated under the stress conditions investigated in the present study. Amino acids involved in metal chelation like proline, histidine and glutamine were significantly increased after exposure to combined Cd stress and N limitation. We conclude that N limitation and Cd stress affects the physiology of C. vulgaris by not only decreasing its growth but also stimulating biomolecule production

  5. Bromine accumulation in acidic black colluvial soils

    Cortizas, Antonio Martínez; Vázquez, Cruz Ferro; Kaal, Joeri; Biester, Harald; Casais, Manuela Costa; Rodríguez, Teresa Taboada; Lado, Luis Rodríguez

    2016-02-01

    Recent investigations showed that bromine is incorporated to soil organic matter (SOM), its content increasing with humification. But few research was done on its long-term accumulation and the role played by pedogenetic processes, as those involved in organic matter stabilization. We investigated bromine content and distribution in four deep, acidic, organic-rich, Holocene soils from an oceanic area of Western Europe. Bromine concentrations (93-778 μg g-1) in the silt + clay (area, and total estimated retention was low (6-16%). The degree of SOM bromination, expressed as the Br/C molar ratio, varied between 0.03 and 1.20 mmol Br/mol C. The ratio was highly correlated (n = 23, r2 0.88, p pool of metal-clay-stabilized organic matter.

  6. Using lead-acid accumulators in hybrid electric vehicle regime

    Hejdiš, Roman

    2010-01-01

    The master´s thesis discuss characteristics of hybrid electric vehicles and lead-acid accumulators applied in car industry. It compares classic and alternative drive in cars, descibes classification of hybrid drives and its characteristics. Further work disscus lead-acid accumulators which focuses on VRLA accumulators applied in hybrid electric cars. Practical part contains a construction description of negative electrode and experiment, which studied influence of various amount addition of c...

  7. Surface-atmosphere decoupling limits accumulation at Summit, Greenland.

    Berkelhammer, Max; Noone, David C; Steen-Larsen, Hans Christian; Bailey, Adriana; Cox, Christopher J; O'Neill, Michael S; Schneider, David; Steffen, Konrad; White, James W C

    2016-04-01

    Despite rapid melting in the coastal regions of the Greenland Ice Sheet, a significant area (~40%) of the ice sheet rarely experiences surface melting. In these regions, the controls on annual accumulation are poorly constrained owing to surface conditions (for example, surface clouds, blowing snow, and surface inversions), which render moisture flux estimates from myriad approaches (that is, eddy covariance, remote sensing, and direct observations) highly uncertain. Accumulation is partially determined by the temperature dependence of saturation vapor pressure, which influences the maximum humidity of air parcels reaching the ice sheet interior. However, independent proxies for surface temperature and accumulation from ice cores show that the response of accumulation to temperature is variable and not generally consistent with a purely thermodynamic control. Using three years of stable water vapor isotope profiles from a high altitude site on the Greenland Ice Sheet, we show that as the boundary layer becomes increasingly stable, a decoupling between the ice sheet and atmosphere occurs. The limited interaction between the ice sheet surface and free tropospheric air reduces the capacity for surface condensation to achieve the rate set by the humidity of the air parcels reaching interior Greenland. The isolation of the surface also acts to recycle sublimated moisture by recondensing it onto fog particles, which returns the moisture back to the surface through gravitational settling. The observations highlight a unique mechanism by which ice sheet mass is conserved, which has implications for understanding both past and future changes in accumulation rate and the isotopic signal in ice cores from Greenland. PMID:27386509

  8. Targeting acid sphingomyelinase reduces cardiac ceramide accumulation in the post-ischemic heart.

    Klevstig, Martina; Ståhlman, Marcus; Lundqvist, Annika; Scharin Täng, Margareta; Fogelstrand, Per; Adiels, Martin; Andersson, Linda; Kolesnick, Richard; Jeppsson, Anders; Borén, Jan; Levin, Malin C

    2016-04-01

    Ceramide accumulation is known to accompany acute myocardial ischemia, but its role in the pathogenesis of ischemic heart disease is unclear. In this study, we aimed to determine how ceramides accumulate in the ischemic heart and to determine if cardiac function following ischemia can be improved by reducing ceramide accumulation. To investigate the association between ceramide accumulation and heart function, we analyzed myocardial left ventricle biopsies from subjects with chronic ischemia and found that ceramide levels were higher in biopsies from subjects with reduced heart function. Ceramides are produced by either de novo synthesis or hydrolysis of sphingomyelin catalyzed by acid and/or neutral sphingomyelinase. We used cultured HL-1 cardiomyocytes to investigate these pathways and showed that acid sphingomyelinase activity rather than neutral sphingomyelinase activity or de novo sphingolipid synthesis was important for hypoxia-induced ceramide accumulation. We also used mice with a partial deficiency in acid sphingomyelinase (Smpd1(+/-) mice) to investigate if limiting ceramide accumulation under ischemic conditions would have a beneficial effect on heart function and survival. Although we showed that cardiac ceramide accumulation was reduced in Smpd1(+/-) mice 24h after an induced myocardial infarction, this reduction was not accompanied by an improvement in heart function or survival. Our findings show that accumulation of cardiac ceramides in the post-ischemic heart is mediated by acid sphingomyelinase. However, targeting ceramide accumulation in the ischemic heart may not be a beneficial treatment strategy. PMID:26930027

  9. Acid Rain Limits Global Warming

    Will Knight; 张林玲

    2004-01-01

    @@ Acid rain restricts global warming by reducing methane① emissions from natural wetland areas, suggests a global climate study. Acid rain is the result of industrial pollution,which causes rainwater to carry small quantities of acidic compoumds② such as sulphuric and nitric acid③. Contaminated rainwater can upset rivers and lakes, killing fish and other organisms and also damage plants, trees and buildings.

  10. Cholic acid is accumulated spontaneously, driven by membrane Delta pH, in many lactobacilli

    Kurdi, P; van Veen, HW; Tanaka, H; Mierau, [No Value; Konings, WN; Tannock, GW; Tomita, F; Yokota, A

    2000-01-01

    Many lactobacilli from various origins were found to apparently lack cholic acid extrusion activity. Cholic acid was accumulated spontaneously, driven by the transmembrane proton gradient. Accumulation is a newly identified kind of interaction between intestinal microbes and unconjugated bile acids

  11. Susceptibility of riparian wetland plants to perfluorooctanoic acid (PFOA) accumulation.

    Mudumbi, J B N; Ntwampe, S K O; Muganza, M; Okonkwo, J O

    2014-01-01

    As plants have been shown to accumulate organic compounds from contaminated sediments, there is a potential for long-lasting ecological impact as a result of contaminant accumulation in riparian areas of wetlands, particularly the accumulation of non-biodegradable contaminants such as perfluorooctanoic acid (PFOA). In this study, commonly found riparian wetland plants including reeds, i.e., Xanthium strumarium, Phragmites australis, Schoenoplectus corymbosus, Ruppia maritime; Populus canescens, Polygonum salicifolium, Cyperus congestus; Persicaria amphibian, Ficus carica, Artemisia schmidtiana, Eichhornia crassipes, were studied to determine their susceptibility to PFOA accumulation from PFOA contaminated riparian sediment with a known PFOA concentration, using liquid chromatography/tandem mass spectrometry (LC/MS/MS). The bioconcentration factor (BCF) indicated that the plants affinity to PFOA accumulation was; E. crassipes, > P. sali-cifolium, > C. congestus, > P. x canescens, > P. amphibian, > F. carica, > A. schmidtiana, > X. strumarium,> P. australis, > R. maritime, > S. corymbosus. The concentration of PFOA in the plants and/or reeds was in the range 11.7 to 38 ng/g, with a BCF range of 0.05 to 0.37. The highest BCF was observed in sediment for which its core water had a high salinity, total organic carbon and a pH which was near neutral. As the studied plants had a higher affinity for PFOA, the resultant effect is that riparian plants such as E. crassipes, X. strumarium, and P. salicifolium, typified by a fibrous rooting system, which grow closer to the water edge, exacerbate the accumulation of PFOA in riparian wetlands. PMID:24933893

  12. Limited accumulation of copper in heavy metal adapted mosses.

    Antreich, Sebastian; Sassmann, Stefan; Lang, Ingeborg

    2016-04-01

    Copper is an essential micronutrient but has toxic effects at high concentrations. Bryophytes are remarkably tolerant to elevated levels of copper but we wondered if this tolerance might be species dependent. Therefore, in three moss species, Physcomitrella patens, Mielichhoferia elongata and Pohlia drummondii, the accumulation of copper was compared with semiquantitative SEM-EDX analyses after six weeks of cultivation on copper containing media. We investigated the role of the copper-linked anion and applied copper as CuCl2, CuSO4 and CuEDTA, respectively. Line scans along the growth axis of moss gametophores allowed for a detailed analysis of copper detection from the base towards the tip. Mosses originating from metal-containing habitats (i.e. M. elongata and P. drummondii) revealed a lower accumulation of copper when compared to the non-adapted P. patens. CuEDTA had a shielding effect in all three species and copper levels differed greatly from CuCl2 or CuSO4. The detection of reactive oxygen species (ROS), H2O2 and O2(-), was further used to indicate stress levels in the gametophore stems. ROS staining was increased along the whole stem and the tip in the non-adapted species P. patens whereas the tolerant species M. elongata and P. drummondii generally showed less staining located mainly at the base of the stem. We discuss the relation between metal accumulation and ROS production using indicator dyes in the three moss species. As moss gametophores are very delicate structures, ROS staining provide an excellent alternative to spectrophotometric analyses to estimate stress levels. PMID:26878481

  13. Global southern limit of flowering plants and moss peat accumulation

    Peter Convey

    2011-10-01

    Full Text Available The ecosystems of the western Antarctic Peninsula, experiencing amongst the most rapid trends of regional climate warming worldwide, are important “early warning” indicators for responses expected in more complex systems elsewhere. Central among responses attributed to this regional warming are widely reported population and range expansions of the two native Antarctic flowering plants, Deschampsia antarctica and Colobanthus quitensis. However, confirmation of the predictions of range expansion requires baseline knowledge of species distributions. We report a significant southwards and westwards extension of the known natural distributions of both plant species in this region, along with several range extensions in an unusual moss community, based on a new survey work in a previously unexamined and un-named low altitude peninsula at 69°22.0′S 71°50.7′W in Lazarev Bay, north-west Alexander Island, southern Antarctic Peninsula. These plant species therefore have a significantly larger natural range in the Antarctic than previously thought. This site provides a potentially important monitoring location near the southern boundary of the region currently demonstrated to be under the influence of rapidly changing climate trends. Combined radiocarbon and lead isotope radiometric dating suggests that this location was most likely deglaciated sufficiently to allow peat to start accumulating towards the end of the 19th century, which we tentatively link to a phase of post-1870 climate amelioration. We conclude that the establishment of vegetation in this location is unlikely to be linked to the rapid regional warming trends recorded along the Antarctic Peninsula since the mid-20th century.

  14. Caffeoylquinic Acids Generated In Vitro in a High-Anthocyanin-Accumulating Sweet potato Cell Line

    Izabela Konczak; Shigenori Okuno; Makoto Yoshimoto; Osamu Yamakawa

    2004-01-01

    Accumulation of phenolic compounds has been monitored in a suspension culture of anthocyanin-accumulating sweet potato cell line grown under the conditions of modified Murashige and Skoog high-anthocyanin production medium (APM) over a period of 24 days. Tissue samples extracted with 15% acetic acid were analysed using HPLC at a detection wavelength of 326 nm. Among others, the following derivatives of caffeoylquinic acids were detected: 4,5-dicaffeoylquinic acid, 3,5-dicaffeoylquinic acid, 3...

  15. Phosphate limitation promotes unsaturated fatty acids and arachidonic acid biosynthesis by microalgae Porphyridium purpureum.

    Su, Gaomin; Jiao, Kailin; Li, Zheng; Guo, Xiaoyi; Chang, Jingyu; Ndikubwimana, Theoneste; Sun, Yong; Zeng, Xianhai; Lu, Yinghua; Lin, Lu

    2016-07-01

    Polyunsaturated fatty acids (PUFAs) are highly appreciated on their nutritive value for human health and aquaculture. P. purpureum, one of the red microalgae acknowledged as a promising accumulator of ARA, was chosen as the target algae in the present research. Effects of sodium bicarbonate (0.04-1.2 g/L), temperature (25, 30 and 33 °C) and phosphate (0.00-0.14 g/L) on biomass yield, total fatty acids (TFA) and arachidonic acid (ARA) accumulation were investigated systemically. NaHCO3 dose of 0.8 g/L and moderate temperature of 30 °C were preferred. In addition, TFA and ARA production were significantly enhanced by an appropriate concentration of phosphate, and the highest TFA yield of 666.38 mg/L and ARA yield of 159.74 mg/L were obtained at a phosphate concentration of 0.035 g/L. Interestingly, with phosphate concentration continuing to fall, UFA/TFA and ARA/EPA ratios were increased accordingly, suggesting that phosphate limitation promoted unsaturated fatty acids and arachidonic acid biosynthesis. Low concentration of phosphate may be favored to increase the enzymatic activities of ∆6-desaturase, which played a key role in catalyzing the conversion of C16:0 to C18:2, and thus the selectivity of UFA increased. Meanwhile, the increase of ARA selectivity could be attributed to ω6 pathway promotion and ∆17-desaturase activity inhibition with phosphate limitation. Phosphate limitation strategy enhanced unsaturated fatty acids and ARA biosynthesis in P. purpureum, and can be applied in commercial scale manufacturing and commercialization of ARA. PMID:27004948

  16. Avoiding propionic acid accumulation in the anaerobic process for biohydrogen production

    The accumulation of propionic acid in the anaerobic process will result in low efficiency of the methanogenic phase due to the low acetogenic rate of propionic acid, and hence low wastewater treatment efficiency. The reasons for propionic acid accumulation in the acidogenic phase and the relationship between the accumulation and biohydrogen generation were studied and a strategy for avoiding propionic acid accumulation in the anaerobic process for biohydrogen generation is also introduced. The experimental results indicate that changing pH and oxidation-reduction potential (ORP) can result in the variation of fermentation type, and maintaining lower ORP and avoiding pH of 5.5 will reduce the accumulation of propionic acid in the anaerobic process. Higher biohydrogen generation rate is not always accompanied with the accumulation of propionic acid. In the acidogenic reactor of two-phase separated anaerobic process, ethanol type fermentation, in which pH at 4.5 below, can produce much more biohydrogen but without accumulation of propionic acid. Thus, ethanol-type fermentation is a better selection when using an acidogenic reactor of a two-phase separated anaerobic process to efficiently produce biohydrogen with simultaneous organic wastewater pre-treatment

  17. Oil and fatty acid accumulation during coriander (Coriandrum sativum L. fruit ripening under organic cultivation

    Quang-Hung Nguyen

    2015-08-01

    Full Text Available To evaluate the accumulation of oil and fatty acids in coriander during fruit ripening, a field experiment was conducted under organic cultivation conditions in Auch (near Toulouse, southwestern France during the 2009 cropping season. The percentage and composition of the fatty acids of coriander were determined by gas chromatography. Our results showed that rapid oil accumulation started in early stages (two days after flowering, DAF. Twelve fatty acids were identified. Saturated and polyunsaturated acids were the dominant fatty acids at earlier stages (2–12 DAF, but decreased after this date. After this stage, petroselinic acid increased to its highest amount at 18 DAF. In contrast, palmitic acid followed the opposite trend. Saturated and polyunsaturated fatty acids decreased markedly and monounsaturated fatty acids increased during fruit maturation. It appears that the fruit of coriander may be harvested before full maturity.

  18. Influence of Climatic Conditions on Accumulation of α-acids in Hop Clones

    Siniša Srečec

    2008-09-01

    Full Text Available The influence of climatic conditions on accumulation of α-acids was determined during the six years (2001 – 2006 of stationary experiment in hop cultivar Aurora. The research results show that increasing sum of effective temperatures during the technological maturity stay in negative correlation with accumulation of α-acids in hop cones (r = - 0.39*, whereas total rainfalls stays in positive one (r = 0.46* At the same time sum of hours of sun shining stay in not significant negative correlation with the accumulation of α-acids (r = - 0.38. The results of factorial analysis show significant positive multiple correlation between sum of effective temperatures and total rainfalls with α-acids accumulation (multiple r = 0.6232** and at the same time show a significant positive multiple correlation between total rainfalls and sunshine hours with α-acids accumulation (multiple r = 0.5492*. However, there was a very strong negative influence of reference crop evapotranspiration during the phenological phase of hop cones formation on yield of hop cones and of α-acids (rs = - 0.75* and – 0.88*, respectively. The total rainfalls during the hop vegetation in interval of [212.1; 391.8] mm and also the sum of effective temperature in interval of [1601.74; 2000] ºC caused the α-acids accumulation in hop cones of cultivar Aurora in interval of [7.41; 12.35] % in dry matter. It is important to point out that the level of provided tillage, plant protection measures and fertilization was the same in all six experimental years, which excluded their effects on accumulation of α-acids. These results could possibly contribute in creating a model of predication of α-acids accumulation and beginning of hop harvest.

  19. Ammonia activates pacC and patulin accumulation in an acidic environment during apple colonization by Penicillium expansum.

    Barad, Shiri; Espeso, Eduardo A; Sherman, Amir; Prusky, Dov

    2016-06-01

    Penicillium expansum, the causal agent of blue mould rot, causes severe post-harvest fruit maceration simultaneously with the secretion of d-gluconic acid (GLA) and the mycotoxin patulin in colonized tissue. The factor(s) inducing patulin biosynthesis during colonization of the host acidic environment is unclear. During the colonization of apple fruit in vivo and growth in culture, P. expansum secretes pH-modulating GLA and ammonia. Although patulin and its possible opportunistic precursor GLA accumulate together during fungal development, ammonia is detected on the colonized tissue's leading edge and after extended culture, close to patulin accumulation. Here, we demonstrate ammonia-induced transcript activation of the global pH modulator PacC and patulin accumulation in the presence of GLA by: (i) direct exogenous treatment of P. expansum growing on solid medium; (ii) direct exogenous treatment on colonized apple tissue; (iii) growth under self-ammonia production conditions with limited carbon; and (iv) analysis of the transcriptional response to ammonia of the patulin biosynthesis cluster. Ammonia induced patulin accumulation concurrently with the transcript activation of pacC and patulin biosynthesis cluster genes, indicating the regulatory effect of ammonia on pacC transcript expression under acidic conditions. Electrophoretic mobility shift assays using P. expansum PacC and antibodies to the different cleaved proteins showed that PacC is not protected against proteolytic signalling at pH 4.5 relative to pH 7.0, but NH4 addition did not further enhance its proteolytic cleavage. Ammonia enhanced the activation of palF transcript in the Pal pathway under acidic conditions. Ammonia accumulation in the host environment by the pathogen under acidic pH may be a regulatory cue for pacC activation, towards the accumulation of secondary metabolites, such as patulin. PMID:26420024

  20. Limited Resources, Limited Opportunities, and the Accumulation of Disadvantage: Evidence from the Global Survey of Physicists

    Ivie, Rachel

    2012-03-01

    Using the results of the Global Survey of Physicists, which we conducted in collaboration with the International Union of Pure and Applied Physics Working Group on Women, we document the effect of limited resources and opportunities on women physicists' careers. We find that women respondents are less likely than men to report access to a variety of resources and opportunities that would be helpful in advancing a scientific career. These include access to funding, travel money, lab and office space, equipment, clerical support, and availability of employees or students to help with research. When asked about specific opportunities, women report fewer invited talks and overseas research opportunities. Women who responded are less likely to have been journal editors, acted as bosses or managers, advised graduate students, served on thesis or dissertation committees, and served on committees for grant agencies. We also show the disproportionate effects of children on women physicists' careers. Women who responded are more likely than men to have changed their work situations upon becoming parents. Mothers are more likely than men and women without children to report that their careers have progressed more slowly than colleagues who finished their degrees at the same time. Furthermore, women are more likely than men to report that their careers affected the decisions they made about marriage and children. The results of this survey draw attention to the need to focus on factors other than representation when discussing the situation of women in physics. 15,000 physicists in 130 countries answered this survey, and across all these countries, women have fewer resources and opportunities and are more affected by cultural expectations concerning child care. Cultural expectations about home and family are difficult to change. However, for women to have successful outcomes and advance in physics, they must have equal access to resources and opportunities.

  1. Hyperosmosis and its combination with nutrient-limitation are novel environmental stressors for induction of triacylglycerol accumulation in cells of Chlorella kessleri.

    Hirai, Kazuho; Hayashi, Taihei; Hasegawa, Yuri; Sato, Atsushi; Tsuzuki, Mikio; Sato, Norihiro

    2016-01-01

    Triacylglycerols of oleaginous algae are promising for production of food oils and biodiesel fuel. Air-drying of cells induces triacylglycerol accumulation in a freshwater green alga, Chlorella kessleri, therefore, it seems that dehydration, i.e., intracellular hyperosmosis, and/or nutrient-limitation are key stressors. We explored this possibility in liquid-culturing C. kessleri cells. Strong hyperosmosis with 0.9 M sorbitol or 0.45 M NaCl for two days caused cells to increase the triacylglycerol content in total lipids from 1.5 to 48.5 and 75.3 mol%, respectively, on a fatty acid basis, whereas nutrient-limitation caused its accumulation to 41.4 mol%. Even weak hyperosmosis with 0.3 M sorbitol or 0.15 M NaCl, when nutrient-limitation was simultaneously imposed, induced triacylglycerol accumulation to 61.9 and 65.7 mol%, respectively. Furthermore, culturing in three-fold diluted seawater, the chemical composition of which resembled that of the medium for the combinatory stress, enabled the cells to accumulate triacylglycerol up to 24.7 weight% of dry cells in only three days. Consequently, it was found that hyperosmosis is a novel stressor for triacylglycerol accumulation, and that weak hyperosmosis, together with nutrient-limitation, exerts a strong stimulating effect on triacylglycerol accumulation. A similar combinatory stress would contribute to the triacylglycerol accumulation in air-dried C. kessleri cells. PMID:27184595

  2. Concomitant extracellular accumulation of alpha-keto acids and higher alcohols by Zygosaccharomyces rouxii.

    Van Der Sluis, Catrinus; Rahardjo, Yovita S P; Smit, Bart A; Kroon, Pieter J; Hartmans, Sybe; Ter Schure, Eelko G; Tramper, Johannes; Wijffels, Renéh

    2002-01-01

    Alpha-keto acids are key intermediates in the formation of higher alcohols, important flavor components in soy sauce, and produced by the salt-tolerant yeast Zygosaccharomyces rouxii. Unlike most of the higher alcohols, the alpha-keto acids are usually not extracellularly accumulated by Z. rouxii when it is cultivated with ammonium as the sole nitrogen source. To facilitate extracellular accumulation of the alpha-keto acids from aspartate-derived amino acid metabolism, the amino acids valine, leucine, threonine and methionine were exogenously supplied during batch and A-star cultivations of (routants of) Z. rouxii. It was shown that all alpha-keto acids from the aspartate-derived amino acid metabolism, except alpha-ketobutyrate, could be extracellularly accumulated. In addition, it appeared from the concomitant extracellular accumulation of alpha-keto acids and higher alcohols that in Z. rouxii, valine, leucine and methionine were converted via Ehrlich pathways similar to those in Saccharomyces cerevisiae. Unlike these amino acids, threonine was converted via both the Ehrlich and amino acid biosynthetic pathways in Z. rouxii. PMID:16233175

  3. AtNOA1 modulates nitric oxide accumulation and stomatal closure induced by salicylic acid in Arabidopsis

    Sun, Li Rong; Hao, Fu Shun; Lu, Bao Shi; Ma, Li Ya

    2010-01-01

    Phytohormone salicylic acid (SA) has been documented to induce nitric oxide (NO) generation and stomatal closure in plants. However, the cellular components mediating these processes are limited. Here, we report that NO synthesis in guard cells and stomatal closure are markedly induced by SA in Arabidopsis wild type plants, whereas these effects caused by SA are suppressed significantly in noa1 T-DNA mutant plants. These results suggest that AtNOA1 regulates SA-triggered NO accumulation and s...

  4. Mechanism and controlling strategy of the production and accumulation of propionic acid for anaerobic wastewater treatment

    任南琪; 李建政; 赵丹; 陈晓蕾

    2002-01-01

    The production and accumulation of propionic acid affect significantly anaerobic wastewater treatment system, but the reasons are not approached until now. Based on the results of continuous-flow tests and the analysis of biochemistry and ecology, two mechanisms of producing propionic acid have been put forward. It is demonstrated that the reasons of propionic acid production and accumulation are not caused by higher hydrogen partial pressure. The combination of specific pH value and ORP is the ecological factor affecting propionic acid production, and the equilibrium regulation of NADH/NAD+ ratio in cells is the physiological factor. Meanwhile, it is put forward that using the two-phase anaerobic treatment process and the ethanol type fermentation in anaerobic reactor to avoid propionic acid accumulation are efficient methods.

  5. Improved cadmium uptake and accumulation in the hyperaccumulator Sedum alfredii: the impact of citric acid and tartaric acid* #

    Lu, Ling-li; Tian, Sheng-ke; Yang, Xiao-e; Peng, Hong-yun; Li, Ting-qiang

    2013-01-01

    The elucidation of a natural strategy for metal hyperaccumulation enables the rational design of technologies for the clean-up of metal-contaminated soils. Organic acid has been suggested to be involved in toxic metallic element tolerance, translocation, and accumulation in plants. The impact of exogenous organic acids on cadmium (Cd) uptake and translocation in the zinc (Zn)/Cd co-hyperaccumulator Sedum alfredii was investigated in the present study. By the addition of organic acids, short-t...

  6. The relationship between lumenal and limiting membranes in swollen late endocytic compartments formed after wortmannin treatment or sucrose accumulation.

    Bright, N A; Lindsay, M R; Stewart, A; Luzio, J P

    2001-09-01

    Immunofluorescence and electron microscopy were used to evaluate the formation of swollen endosomes in NRK cells after treatment with wortmannin or sucrose and to study the relationship between lumenal and limiting membrane. Both treatments resulted in the formation of two populations of swollen late endocytic vacuoles, positive for lysosomal glycoproteins or cation-independent mannose 6-phosphate receptors, but those induced by wortmannin were characterised by time-dependent accumulation of lumenal vesicles, whereas those induced by sucrose uptake did not accumulate lumenal vesicles. In both cases, the distribution of the late endosomal marker, lysobisphosphatidic acid, remained unchanged and was present within the lumen of the swollen vacuoles. Consumption of plasma membrane and peripheral early endosomes, and the appearance of transferrin receptors in swollen late endosomes, indicated that continued membrane influx from early endocytic compartments, together with inhibition of membrane traffic out of the swollen compartments, is sufficient to account for the observed phenotype of cells treated with wortmannin. The accumulation of organelles with the characteristic morphology of endocytic carrier vesicles in cells that have taken up sucrose offers an explanation for the paucity of lumenal vesicles in swollen sucrosomes. Our data suggest that in fibroblast cells the swollen endosome phenotype induced by wortmannin is a consequence of endocytic membrane influx, coupled with the failure to recycle membrane to other cellular destinations, and not the inhibition of multivesicular body biogenesis. PMID:11555417

  7. Detoxification and Accumulation of Cadmium and Arsenic in Plants : : Implications for Phytoremediation and Limiting Accumulation in Foods

    Jobe, Timothy O.

    2013-01-01

    Many of the metals and metalloids commonly used by our modern society are extremely toxic and can pose a significant health risk if consumed. However, unlike animals, some plants are often extremely tolerant to the toxic effects of these metals and can accumulate large amounts in various tissues. Because some plants can bioaccumulate toxic metals, a number of bioremediation strategies using plants have been proposed. However, accumulation of toxic metals in agronomic crops is not desirable. I...

  8. Intracellular boron accumulation in CHO-K1 cells using amino acid transport control

    BPA used in BNCT has a similar structure to some essential amino acids and is transported into tumor cells by amino acid transport systems. Previous study groups have tried various techniques of loading BPA to increase intracellular boron concentration. CHO-K1 cells demonstrate system L (LAT1) activity and are suitable for specifying the transport system of a neutral amino acid. In this study, we examined the intracellular accumulation of boron in CHO-K1 cells by amino acid transport control, which involves co-loading with L-type amino acid esters. Intracellular boron accumulation in CHO-K1 cells showed the greatest increased upon co-loading 1.0 mM BPA, with 1.0 mM L-Tyr-O-Et and incubating for 60 min. This increase is caused by activation of a system L amino acid exchanger between BPA and L-Tyr. The amino acid esters are metabolized to amino acids by intracellular hydrolytic enzymes that increase the concentrations of intracellular amino acids and stimulate exchange transportation. We expect that this amino acid transport control will be useful for enhancing intracellular boron accumulation. - Highlights: • We examined optimal L-p-boronophenylalanine (BPA) loading in CHO-K1 cells. • Optimal BPA loading parameters were 1.0 mM and incubation for 60 min. • Intracellular boron accumulation increased upon co-loading BPA with L-Tyr-O-Et. • Optimal L-Tyr-O-Et loading parameters were 1.0 mM and incubation for 60 min. • Co-loading BPA with L-Tyr-O-Et can increase intracellular boron accumulation

  9. Rhodobacter sphaeroides mutants which accumulate 5-aminolevulinic acid under aerobic and dark conditions.

    Nishikawa, S; Watanabe, K; Tanaka, T; Miyachi, N; Hotta, Y; Murooka, Y

    1999-01-01

    The photosynthetic bacterium Rhodobacter sphaeroides accumulates 5-aminolevulinic acid (ALA), which is a precursor in tetrapyrrole biosynthesis, under light illumination and upon addition of levulinic acid as an inhibitor of ALA dehydratase. To generate an industrial strain which produces ALA in the absence of light, we sequentially mutated R. sphaeroides CR-286 using N-methyl-N'-nitro-N-nitrosoguanidine (NTG). The mutant strains were screened by cultivating in the absence of light and assayed for ALA by the Ehrlich reaction in a 96-well microtiter plate. The mutant strain CR-386, derived from R. sphaeroides CR-286, was selected as a mutant that exhibited significant ALA accumulation. While CR-286 required light illumination for ALA production, CR-386 was able to accumulate 1.5 mM ALA in the presence of 50 mM glucose, 60 mM glycine, 15 mM levulinic acid and 1.0% (w/v) yeast extract under conditions of agitation in the absence of light. The mutant strain CR-450, derived from strain CR-386, was selected further as a mutant that exhibited significant ALA accumulation but no accumulation of aminoacetone, analogue of ALA. CR-450 accumulated 3.8 mM ALA under the same conditions. In the presence of 50 mM glucose, 60 mM glycine, 5 mM levulinic acid and 1.0% (w/v) yeast extract, the mutant strain CR-520, derived from strain CR-450, and strain CR-606, derived from strain CR-520, accumulated 8.1 mM and 11.2 mM ALA, respectively. In batch fermentation, the strain CR-606 accumulated 20 mM ALA over 18 h after the addition of glycine, levulinic acid, glucose and yeast extract. PMID:16232557

  10. Effect of acetic acid on lipid accumulation by glucose-fed activated sludge cultures

    Mondala, Andro; Hernandez, Rafael; French, Todd; McFarland, Linda; Sparks, Darrell; Holmes, William; Haque, Monica

    2012-01-01

    The effect of acetic acid, a lignocellulose hydrolysis by-product, on lipid accumulation by activated sludge cultures grown on glucose was investigated. This was done to assess the possible application of lignocellulose as low-cost and renewable fermentation substrates for biofuel feedstock production. Results: Biomass yield was reduced by around 54% at a 2 g L -1 acetic acid dosage but was increased by around 18% at 10 g L -1 acetic acid dosage relative to the control run. The final gravimetric lipid contents at 2 and 10 g L -1 acetic acid levels were 12.5 + 0.7% and 8.8 + 3.2% w/w, respectively, which were lower than the control (17.8 + 2.8% w/w). However, biodiesel yields from activated sludge grown with acetic acid (5.6 + 0.6% w/w for 2 g L -1 acetic acid and 4.2 + 3.0% w/w for 10 g L -1 acetic acid) were higher than in raw activated sludge (1-2% w/w). The fatty acid profiles of the accumulated lipids were similar with conventional plant oil biodiesel feedstocks. Conclusions: Acetic acid enhanced biomass production by activated sludge at high levels but reduced lipid production. Further studies are needed to enhance acetic acid utilization by activated sludge microorganisms for lipid biosynthesis.

  11. Influence of earthworm mucus and amino acids on tomato seedling growth and cadmium accumulation

    The effects on the growth of tomato seedlings and cadmium accumulation of earthworm mucus and a solution of amino acids matching those in earthworm mucus was studied through a hydroponic experiment. The experiment included four treatments: 5 mg Cd L-1 (CC), 5 mg Cd L-1 + 100 mL L-1 earthworm mucus (CE), 5 mg Cd L-1 + 100 mL L-1 amino acids solution (CA) and the control (CK). Results showed that, compared with CC treatment, either earthworm mucus or amino acids significantly increased tomato seedling growth and Cd accumulation but the increase was much higher in the CE treatment compared with the CA treatment. This may be due to earthworm mucus and amino acids significantly increasing the chlorophyll content, antioxidative enzyme activities, and essential microelement uptake and transport in the tomato seedlings. The much greater increase in the effect of earthworm mucus compared with amino acid treatments may be due to IAA-like substances in earthworm mucus. - Earthworm mucus increased tomato seedlings growth and Cd accumulation through increasing chlorophyll content, antioxidative enzyme activities, and essential microelement accumulation.

  12. Influence of earthworm mucus and amino acids on tomato seedling growth and cadmium accumulation

    Zhang Shujie [College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095 (China); Hu Feng, E-mail: fenghu@njau.edu.c [College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095 (China); Li Huixin; Li Xiuqiang [College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095 (China)

    2009-10-15

    The effects on the growth of tomato seedlings and cadmium accumulation of earthworm mucus and a solution of amino acids matching those in earthworm mucus was studied through a hydroponic experiment. The experiment included four treatments: 5 mg Cd L{sup -1} (CC), 5 mg Cd L{sup -1} + 100 mL L{sup -1} earthworm mucus (CE), 5 mg Cd L{sup -1} + 100 mL L{sup -1} amino acids solution (CA) and the control (CK). Results showed that, compared with CC treatment, either earthworm mucus or amino acids significantly increased tomato seedling growth and Cd accumulation but the increase was much higher in the CE treatment compared with the CA treatment. This may be due to earthworm mucus and amino acids significantly increasing the chlorophyll content, antioxidative enzyme activities, and essential microelement uptake and transport in the tomato seedlings. The much greater increase in the effect of earthworm mucus compared with amino acid treatments may be due to IAA-like substances in earthworm mucus. - Earthworm mucus increased tomato seedlings growth and Cd accumulation through increasing chlorophyll content, antioxidative enzyme activities, and essential microelement accumulation.

  13. Exogenous malic and acetic acids reduce cadmium phytotoxicity and enhance cadmium accumulation in roots of sunflower plants.

    Hawrylak-Nowak, Barbara; Dresler, Sławomir; Matraszek, Renata

    2015-09-01

    There is increasing evidence showing that low molecular weight organic acids (LMWOA) are involved in heavy metal resistance mechanisms in plants. The aim of this study was to investigate the effects of exogenous malic (MA) or acetic (AA) acids on the toxicity and accumulation of cadmium (Cd) in sunflower (Helianthus annuus L.). For this purpose, plants were grown in hydroponics under controlled conditions. Single Cd stress (5 μM Cd for 14 days) induced strong phytotoxic effects, as indicated by a decrease in all growth parameters, concentration of photosynthetic pigments, and root activity, as well as a high level of hydrogen peroxide (H2O2) accumulation. Exogenous MA or AA (250 or 500 μM) applied to the Cd-containing medium enhanced the accumulation of Cd by the roots and limited Cd translocation to the shoots. Moreover, the MA or AA applied more or less reduced Cd phytotoxicity by increasing the growth parameters, photosynthetic pigment concentrations, decreasing accumulation of H2O2, and improving the root activity. Of the studied organic acids, MA was much more efficient in mitigation of Cd toxicity than AA, probably by its antioxidant effects, which were stronger than those of AA. Plant response to Cd involved decreased production of endogenous LMWOA, probably as a consequence of severe Cd toxicity. The addition of MA or AA to the medium increased endogenous accumulation of LMWOA, especially in the roots, which could be beneficial for plant metabolism. These results imply that especially MA may be involved in the processes of Cd uptake, translocation, and tolerance in plants. PMID:26115548

  14. Systems biology and metabolic modelling unveils limitations to polyhydroxybutyrate accumulation in sugarcane leaves; lessons for C4 engineering.

    McQualter, Richard B; Bellasio, Chandra; Gebbie, Leigh K; Petrasovits, Lars A; Palfreyman, Robin W; Hodson, Mark P; Plan, Manuel R; Blackman, Deborah M; Brumbley, Stevens M; Nielsen, Lars K

    2016-02-01

    In planta production of the bioplastic polyhydroxybutyrate (PHB) is one important way in which plant biotechnology can address environmental problems and emerging issues related to peak oil. However, high biomass C4 plants such as maize, switch grass and sugarcane develop adverse phenotypes including stunting, chlorosis and reduced biomass as PHB levels in leaves increase. In this study, we explore limitations to PHB accumulation in sugarcane chloroplasts using a systems biology approach, coupled with a metabolic model of C4 photosynthesis. Decreased assimilation was evident in high PHB-producing sugarcane plants, which also showed a dramatic decrease in sucrose and starch content of leaves. A subtle decrease in the C/N ratio was found which was not associated with a decrease in total protein content. An increase in amino acids used for nitrogen recapture was also observed. Based on the accumulation of substrates of ATP-dependent reactions, we hypothesized ATP starvation in bundle sheath chloroplasts. This was supported by mRNA differential expression patterns. The disruption in ATP supply in bundle sheath cells appears to be linked to the physical presence of the PHB polymer which may disrupt photosynthesis by scattering photosynthetically active radiation and/or physically disrupting thylakoid membranes. PMID:26015295

  15. Expression of fatty acid synthesis genes and fatty acid accumulation in haematococcus pluvialis under different stressors

    Lei Anping

    2012-03-01

    Full Text Available Abstract Background Biofuel has been the focus of intensive global research over the past few years. The development of 4th generation biofuel production (algae-to-biofuels based on metabolic engineering of algae is still in its infancy, one of the main barriers is our lacking of understanding of microalgal growth, metabolism and biofuel production. Although fatty acid (FA biosynthesis pathway genes have been all cloned and biosynthesis pathway was built up in some higher plants, the molecular mechanism for its regulation in microalgae is far away from elucidation. Results We cloned main key genes for FA biosynthesis in Haematococcus pluvialis, a green microalga as a potential biodiesel feedstock, and investigated the correlations between their expression alternation and FA composition and content detected by GC-MS under different stress treatments, such as nitrogen depletion, salinity, high or low temperature. Our results showed that high temperature, high salinity, and nitrogen depletion treatments played significant roles in promoting microalgal FA synthesis, while FA qualities were not changed much. Correlation analysis showed that acyl carrier protein (ACP, 3-ketoacyl-ACP-synthase (KAS, and acyl-ACP thioesterase (FATA gene expression had significant correlations with monounsaturated FA (MUFA synthesis and polyunsaturated FA (PUFA synthesis. Conclusions We proposed that ACP, KAS, and FATA in H. pluvialis may play an important role in FA synthesis and may be rate limiting genes, which probably could be modified for the further study of metabolic engineering to improve microalgal biofuel quality and production.

  16. Transcriptional and antioxidative responses to endogenous polyunsaturated fatty acid accumulation in yeast.

    Andrisic, Luka; Collinson, Emma J; Tehlivets, Oksana; Perak, Eleonora; Zarkovic, Tomislav; Dawes, Ian W; Zarkovic, Neven; Cipak Gasparovic, Ana

    2015-01-01

    Pathophysiology of polyunsaturated fatty acids (PUFAs) is associated with aberrant lipid and oxygen metabolism. In particular, under oxidative stress, PUFAs are prone to autocatalytic degradation via peroxidation, leading to formation of reactive aldehydes with numerous potentially harmful effects. However, the pathological and compensatory mechanisms induced by lipid peroxidation are very complex and not sufficiently understood. In our study, we have used yeast capable of endogenous PUFA synthesis in order to understand the effects triggered by PUFA accumulation on cellular physiology of a eukaryotic organism. The mechanisms induced by PUFA accumulation in S. cerevisiae expressing Hevea brasiliensis Δ12-fatty acid desaturase include down-regulation of components of electron transport chain in mitochondria as well as up-regulation of pentose-phosphate pathway and fatty acid β-oxidation at the transcriptional level. Interestingly, while no changes were observed at the transcriptional level, activities of two important enzymatic antioxidants, catalase and glutathione-S-transferase, were altered in response to PUFA accumulation. Increased intracellular glutathione levels further suggest an endogenous oxidative stress and activation of antioxidative defense mechanisms under conditions of PUFA accumulation. Finally, our data suggest that PUFA in cell membrane causes metabolic changes which in turn lead to adaptation to endogenous oxidative stress. PMID:25280400

  17. Gama-aminobutyric acid accumulation in Elsholtzia splendens in response to copper toxicity

    YANG Xiao-e; PENG Hong-yun; TIAN Sheng-ke

    2005-01-01

    A solution with different Cu supply levels was cultured to investigate gama-aminobutyric acid (GABA) accumulation in Elsholtzia splendens, a native Chinese Cu-tolerant and accumulating plant species. Increasing Cu from 0.25 to 500 ?mol/L significantly enhanced levels of GABA and histidine (His), but considerably decreased levels of aspartate (Asp) and glutamate (Glu) in the leaves. The leaf Asp level negatively correlated with leaf Cu level, while leaf GABA level positively correlated with leaf Cu level. The leaf Glu level negatively correlated with leaf GABA level in Elsholtzia splendens. The depletion of leaf Glu may be related to the enhanced synthesis ofleafGABA under Cu stress.

  18. Accumulation of aluminium and iron by bryophytes in streams affected by acid-mine drainage

    Engleman, C.J.; McDiffett, W.F. [Bucknell University, Lewisburg, PA (United States). Dept. of Biology

    1996-12-31

    This paper examines the accumulation of two heavy metals (Al and Fe) by bryophytes in a northern Pennsylvania stream system affected by acid-mine drainage. Four sites within one watershed were selected on the basis of their pH and dissolved metal concentrations. Significant differences among sites were found with regard to bioaccumulation of Al an Fe. A negative relationship between pH and Fe concentrations in bryophyte tissues was found, with the highest accumulation of Fe observed at the most acidic site (pH 3.5), whereas accumulation of Al was highest at a site with an intermediate pH of 5.2. Bryophytes transplanted from a circum-neutral site to acidic sites showed highly significant increases in Fe and Al concentrations in tissues after 6 weeks, and transplants from more acidic sites to a circum-neutral site generally showed highly significant declines in Fe and Al concentration in tissues after the incubation period.

  19. [Relationships between cadmium accumulation and organic acids in leaves of Solanum nigrum L. as a cadmium-hyperaccumulator].

    Sun, Rui-lian; Zhou, Qi-xing; Wang, Xin

    2006-04-01

    The influence of different cadmium concentrations on the organic acid level in leaves of the Cd hyperaccumulator, Solanum nigrum L., in particular, the relationship of organic acids with Cd accumulation in S. nigrum was investigated based on the pot-culture experiment. The results showed that the Cd concentration in S. nigrum leaves exceeded 100 microg x g(-1), the threshold value used to define Cd-hyperaccumulators, and the bioaccumulation coefficient of cadmium in shoots of S. nigrum was higher than 1 when Cd concentration in soil was 25 microg x g(-1). The level of organic acids in leaves of S. nigrum had significant differences between the seedling stage and the mature stage. At the seedling stage, the sequence of organic acids in leaves of S. nigrum was acetic acid> tartaric acid> malic acid> citric acid. On the contrary, the accumulation of organic acids in S. nigrum at the mature stage was approximately in the following sequence malic acid> tartaric acid, acetic acid> citric acid. The significant positive correlation between Cd accumulation in leaves of S. nigrum and the concentration of tartaric acid in leaves of S. nigrum was observed at the seedling stage, whereas there was a significant positive correlation between Cd accumulation in leaves of S. nigrum and both acetic and citric acid concentrations at the mature stage. These results indicated that tartaric, acetic and citric acids in leaves of S. nigrum might act as the indication of Cd hyperaccumulation. PMID:16768003

  20. Identity of the Growth-Limiting Nutrient Strongly Affects Storage Carbohydrate Accumulation in Anaerobic Chemostat Cultures of Saccharomyces cerevisiae

    Hazelwood, L.A.; Walsh, M.C.; Luttik, M.A.H.; Daran-Lapujade, P.; Pronk, J.T.; Daran, J.M.

    2009-01-01

    OA Fund TU Delft Accumulation of glycogen and trehalose in nutrient-limited cultures of Saccharomyces cerevisiae is negatively correlated with the specific growth rate. Additionally, glucose-excess conditions (i.e., growth limitation by nutrients other than glucose) are often implicated in high-lev

  1. Accumulation of the Antibiotic Phenazine-1-Carboxylic Acid in the Rhizosphere of Dryland Cereals

    Mavrodi, Dmitri V; Mavrodi, Olga V; Parejko, James A.; Bonsall, Robert F.; Kwak, Youn-Sig; Paulitz, Timothy C.; Thomashow, Linda S.; Weller, David M

    2012-01-01

    Natural antibiotics are thought to function in the defense, fitness, competitiveness, biocontrol activity, communication, and gene regulation of microorganisms. However, the scale and quantitative aspects of antibiotic production in natural settings are poorly understood. We addressed these fundamental questions by assessing the geographic distribution of indigenous phenazine-producing (Phz+) Pseudomonas spp. and the accumulation of the broad-spectrum antibiotic phenazine-1-carboxylic acid (P...

  2. Prolonged acid rain facilitates soil organic carbon accumulation in a mature forest in Southern China.

    Wu, Jianping; Liang, Guohua; Hui, Dafeng; Deng, Qi; Xiong, Xin; Qiu, Qingyan; Liu, Juxiu; Chu, Guowei; Zhou, Guoyi; Zhang, Deqiang

    2016-02-15

    With the continuing increase in anthropogenic activities, acid rain remains a serious environmental threat, especially in the fast developing areas such as southern China. To detect how prolonged deposition of acid rain would influence soil organic carbon accumulation in mature subtropical forests, we conducted a field experiment with simulated acid rain (SAR) treatments in a monsoon evergreen broadleaf forest at Dinghushan National Nature Reserve in southern China. Four levels of SAR treatments were set by irrigating plants with water of different pH values: CK (the control, local lake water, pH ≈ 4.5), T1 (water pH=4.0), T2 (water pH=3.5), and T3 (water pH=3.0). Results showed reduced pH measurements in the topsoil exposed to simulated acid rains due to soil acidification. Soil respiration, soil microbial biomass and litter decomposition rates were significantly decreased by the SAR treatments. As a result, T3 treatment significantly increased the total organic carbon by 24.5% in the topsoil compared to the control. Furthermore, surface soil became more stable as more recalcitrant organic matter was generated under the SAR treatments. Our results suggest that prolonged acid rain exposure may have the potential to facilitate soil organic carbon accumulation in the subtropical forest in southern China. PMID:26657252

  3. Effects of Aeration Treatment on γ-Aminobutyric Acid Accumulation in Germinated Tartary Buckwheat (Fagopyrum tataricum

    Yuanxin Guo

    2016-01-01

    Full Text Available To explore the optimum condition of γ-aminobutyric acid (GABA accumulation in germinated tartary buckwheat, effects of some factors including aeration treatment, physiological indexes, air flow rate, culture temperature, and pH value of cultivating solution under hypoxia on GABA in germinated tartary buckwheat were investigated. The results showed that the dark cultures with distilled water at 30°C, 2 days, and aeration stress with 1.0 L/min air flow rate at 30°C were optimal for GABA accumulation. Under these conditions, the predicted content of GABA was up to 371.98 μg/g DW. The analysis of correlation indicated that there was a significant correlation (P<0.01 between GABA accumulation and physiological indexes. Box-Behnken experimental analysis revealed that optimal conditions with aeration treatment for GABA accumulation in germinated tartary buckwheat were air flow rate of 1.04 L/min, culture temperature of 31.25°C, and a pH value of 4.21. Under these conditions, the GABA content was predicted as high as 386.20 μg/g DW, which was close to the measured value (379.00±9.30 μg/g DW. The variance analysis and validation test suggested that this established regression model could predict GABA accumulation in tartary buckwheat during germination.

  4. Modelling metal accumulation using humic acid as a surrogate for plant roots.

    Le, T T Yen; Swartjes, Frank; Römkens, Paul; Groenenberg, Jan E; Wang, Peng; Lofts, Stephen; Hendriks, A Jan

    2015-04-01

    Metal accumulation in roots was modelled with WHAM VII using humic acid (HA) as a surrogate for root surface. Metal accumulation was simulated as a function of computed metal binding to HA, with a correction term (E(HA)) to account for the differences in binding site density between HA and root surface. The approach was able to model metal accumulation in roots to within one order of magnitude for 95% of the data points. Total concentrations of Mn in roots of Vigna unguiculata, total concentrations of Ni, Zn, Cu and Cd in roots of Pisum sativum, as well as internalized concentrations of Cd, Ni, Pb and Zn in roots of Lolium perenne, were significantly correlated to the computed metal binding to HA. The method was less successful at modelling metal accumulation at low concentrations and in soil experiments. Measured concentrations of Cu internalized in L. perenne roots were not related to Cu binding to HA modelled and deviated from the predictions by over one order of magnitude. The results indicate that metal uptake by roots may under certain conditions be influenced by conditional physiological processes that cannot simulated by geochemical equilibrium. Processes occurring in chronic exposure of plants grown in soil to metals at low concentrations complicate the relationship between computed metal binding to HA and measured metal accumulation in roots. PMID:25482978

  5. Competing mechanisms for perfluoroalkyl acid accumulation in plants revealed using an Arabidopsis model system.

    Müller, Claudia E; LeFevre, Gregory H; Timofte, Anca E; Hussain, Fatima A; Sattely, Elizabeth S; Luthy, Richard G

    2016-05-01

    Perfluoroalkyl acids (PFAAs) bioaccumulate in plants, presenting a human exposure route if present in irrigation water. Curiously, accumulation of PFAAs in plant tissues is greatest for both the short-chain and long-chain PFAAs, generating a U-shaped relationship with chain length. In the present study, the authors decouple competing mechanisms of PFAA accumulation using a hydroponic model plant system (Arabidopsis thaliana) exposed to a suite of 10 PFAAs to determine uptake, depuration, and translocation kinetics. Rapid saturation of root concentrations occurred for all PFAAs except perfluorobutanoate, the least-sorptive (shortest-chain) PFAA. Shoot concentrations increased continuously, indicating that PFAAs are efficiently transported and accumulate in shoots. Tissue concentrations of PFAAs during depuration rapidly declined in roots but remained constant in shoots, demonstrating irreversibility of the translocation process. Root and shoot concentration factors followed the U-shaped trend with perfluoroalkyl chain length; however, when normalized to dead-tissue sorption, this relationship linearized. The authors therefore introduce a novel term, the "sorption normalized concentration factor," to describe PFAA accumulation in plants; because of their hydrophobicity, sorption is the determining factor for long-chain PFAAs, whereas the shortest-chain PFAAs are most effectively transported in the plant. The present study provides a mechanistic explanation for previously unexplained PFAA accumulation trends in plants and suggests that shorter-chained PFAAs may bioaccumulate more readily in edible portions. Environ Toxicol Chem 2016;35:1138-1147. © 2015 SETAC. PMID:26383989

  6. Multidrug Efflux Transporters Limit Accumulation of Inorganic, but Not Organic, Mercury in Sea Urchin Embryos

    BOŠNJAK, IVANA; Uhlinger, Kevin R.; Heim, Wesley; Smital, Tvrtko; Franekić-Čolić, Jasna; Coale, Kenneth; Epel, David; Hamdoun, Amro

    2009-01-01

    Mercuric compounds are persistent global pollutants that accumulate in marine organisms and in humans who consume them. While the chemical cycles and speciation of mercury in the oceans are relatively well described, the cellular mechanisms that govern which forms of mercury accumulate in cells and why they persist are less understood. In this study we examined the role of multidrug efflux transport in the differential accumulation of inorganic (HgCl2) and organic (CH3HgCl) mercury in sea urc...

  7. Dry matter accumulation in citrus fruit is not limited by transport capacity of the pedicel.

    Garcia-Luis, A; Oliveira, M E M; Bordon, Y; Siqueira, D L; Tominaga, S; Guardiola, J L

    2002-12-01

    The vascularization of the pedicel in Marisol clementine (Citrus clementina Hort. ex Tanaka) has been characterized in relation to fruit growth. Phloem and xylem formation occurred during the first half of the period of fruit growth. Phloem cross-sectional area reached its maximum value by the end of fruitlet abscission, 78 d after anthesis (DAA), shortly after the rate of accumulation of dry matter in fruitlets reached its maximum value. Secondary xylem formation occurred until day 93, well after the end of fruitlet abscission. At fruit maturity, xylem accounted for 42-46 % of the cross-section of the pedicel. Vessels differentiated in this late-formed xylem. Formation of phloem and early xylem was directly related to fruitlet size (and growth rate). Differences in the rate of formation of conductive tissues in the pedicel of the developing fruitlets followed rather than preceded the differences in growth rate. Specific mass transfer (SMT) in the phloem was highest in the fastest growing fruitlets, and peaked during the late stages of fruitlet abscission (72-78 DAA) and during the main period of fruit growth (107-121 DAA). Application of a synthetic auxin to developing fruits, either at the end of flowering (2,4-D) or by day 64 after flowering (2,4-DP), increased the growth rate of the fruit and fruit size at maturity (8-13 % increase in fruit diameter at maturity). These auxin applications also enhanced the formation of conductive tissues in the pedicel, with a specific effect on phloem formation. Applying auxin at flowering resulted in a reduction in the phloem SMT by days 72-78, whereas auxin application on day 64 increased this parameter. Despite this difference in behaviour, which resulted from the different time-course of the growth response of the fruit to auxin applications, these applications increased fruit size to a similar extent. Severing 37 % of the phloem of the pedicel during the main period of fruit growth resulted in an increase in the specific

  8. Conjugated Linoleic Acid Accumulation via 10-Hydroxy-12-Octadecaenoic Acid during Microaerobic Transformation of Linoleic Acid by Lactobacillus acidophilus

    Ogawa, Jun; Matsumura, Kenji; Kishino, Shigenobu; Omura, Yoriko; Shimizu, Sakayu

    2001-01-01

    Specific isomers of conjugated linoleic acid (CLA), a fatty acid with potentially beneficial physiological and anticarcinogenic effects, were efficiently produced from linoleic acid by washed cells of Lactobacillus acidophilus AKU 1137 under microaerobic conditions, and the metabolic pathway of CLA production from linoleic acid is explained for the first time. The CLA isomers produced were identified as cis-9, trans-11- or trans-9, cis-11-octadecadienoic acid and trans-9, trans-11-octadecadie...

  9. Regulation and limitations to fatty acid oxidation during exercise

    Jeppesen, Jacob; Kiens, Bente

    2012-01-01

    turn is trapped by carnitine. This will lead to less availability of free carnitine for fatty acid transport into mitochondria. This review summarizes our present view on how FA metabolism is regulated during exercise with a special focus on the limitations in FA oxidation in the transition from...

  10. Improved cadmium uptake and accumulation in the hyperaccumulator Sedum alfredii: the impact of citric acid and tartaric acid.

    Lu, Ling-li; Tian, Sheng-ke; Yang, Xiao-e; Peng, Hong-yun; Li, Ting-qiang

    2013-02-01

    The elucidation of a natural strategy for metal hyperaccumulation enables the rational design of technologies for the clean-up of metal-contaminated soils. Organic acid has been suggested to be involved in toxic metallic element tolerance, translocation, and accumulation in plants. The impact of exogenous organic acids on cadmium (Cd) uptake and translocation in the zinc (Zn)/Cd co-hyperaccumulator Sedum alfredii was investigated in the present study. By the addition of organic acids, short-term (2 h) root uptake of (109)Cd increased significantly, and higher (109)Cd contents in roots and shoots were noted 24 h after uptake, when compared to controls. About 85% of the (109)Cd taken up was distributed to the shoots in plants with citric acid (CA) treatments, as compared with 75% within controls. No such effect was observed for tartaric acid (TA). Reduced growth under Cd stress was significantly alleviated by low CA. Long-term application of the two organic acids both resulted in elevated Cd in plants, but the effects varied with exposure time and levels. The results imply that CA may be involved in the processes of Cd uptake, translocation and tolerance in S. alfredii, whereas the impact of TA is mainly on the root uptake of Cd. PMID:23365009

  11. Improved cadmium uptake and accumulation in the hyperaccumulator Sedum alfredii:the impact of citric acid and tartaric acid

    Ling-li LU; Sheng-ke TIAN; Xiao-e YANG; Hong-yun PENG; Ting-qiang LI

    2013-01-01

    The elucidation of a natural strategy for metal hyperaccumulation enables the rational design of technologies for the clean-up of metal-contaminated soils.Organic acid has been suggested to be involved in toxic metallic element tolerance,translocation,and accumulation in plants.The impact of exogenous organic acids on cadmium(Cd)uptake and translocation in the zinc(Zn)/Cd co-hyperaccumulator Sedum alfredii was investigated in the present study.By the addition of organic acids,short-term(2 h)root uptake of 109Cd increased significantly,and higher 109Cd contents in roots and shoots were noted 24 h after uptake,when compared to controls.About 85% of the 109Cd taken up was distributed to the shoots in plants with citric acid(CA)treatments,as compared with 75% within controls.No such effect was observed for tartaric acid(TA).Reduced growth under Cd stress was significantly alleviated by low CA.Long-term application of the two organic acids both resulted in elevated Cd in plants,but the effects varied with exposure time and levels.The results imply that CA may be involved in the processes of Cd uptake,translocation and tolerance in S.alfredii,whereas the impact of TA is mainly on the root uptake of Cd.

  12. Improved cadmium uptake and accumulation in the hyperaccumulator Sedum alfredii: the impact of citric acid and tartaric acid* #

    Lu, Ling-li; Tian, Sheng-ke; Yang, Xiao-e; Peng, Hong-yun; Li, Ting-qiang

    2013-01-01

    The elucidation of a natural strategy for metal hyperaccumulation enables the rational design of technologies for the clean-up of metal-contaminated soils. Organic acid has been suggested to be involved in toxic metallic element tolerance, translocation, and accumulation in plants. The impact of exogenous organic acids on cadmium (Cd) uptake and translocation in the zinc (Zn)/Cd co-hyperaccumulator Sedum alfredii was investigated in the present study. By the addition of organic acids, short-term (2 h) root uptake of 109Cd increased significantly, and higher 109Cd contents in roots and shoots were noted 24 h after uptake, when compared to controls. About 85% of the 109Cd taken up was distributed to the shoots in plants with citric acid (CA) treatments, as compared with 75% within controls. No such effect was observed for tartaric acid (TA). Reduced growth under Cd stress was significantly alleviated by low CA. Long-term application of the two organic acids both resulted in elevated Cd in plants, but the effects varied with exposure time and levels. The results imply that CA may be involved in the processes of Cd uptake, translocation and tolerance in S. alfredii, whereas the impact of TA is mainly on the root uptake of Cd. PMID:23365009

  13. ACCUMULATION OF POLYHYDROXYALKANOIC ACIDS BY AZOTOBACTER CHROOCOCCUM MAL-201 FROM ORGANIC WASTE

    Soma Pal Saha

    2013-08-01

    Full Text Available Azotobacter chroococcum MAL-201 (MTCC 3853, a free-living nitrogen-fixing bacterium accumulated intracellular poly(3-hydroxybutyric acid [P(3HB] accounting 69% of cell dry weight (CDW when grown in nitrogrn-free Stockdale medium containing 2% (w/v glucose. It also produced copolymer of poly(3-hydroxybutyrate co-3-hydroxyvalerate [P(3HB-co-3HV] using glucose as primary carbon source and valerate cas cosubstrate. To make the polymer production cost effective four types of waste material of different origin were tested for growth and polymer production. Stockdale medium supplemented with 1% (w/v waste materials failed to yield good growth and polymer accumulation. Two–step cultivation was adopted for better growth and enhanced polymer accumulation. The candy factory waste was most suitable for synthesis of P(3HB accounting 17.8 and 40.58% using single and two-step cultivation conditions respectively. Wastes of domestic and poultry origin produced P(3HB-co-3HV with 3HV content 28.8 and 21.5 mol% respectively in two-step cultivation. Increase concentration of these wastes resulted in further upliftment of 3HV content of polymer with reduced growth and polymer accumulation. However, at optimum incubation the strain MAL-201 cells accumulated P(3HB 48.5% of CDW (at 40h from candy factory waste and P(3HB-co-3HV 24.75 % of CDW with 3HV 34.65 mol % from domestic waste. Intrinsic viscosity, molecular weight and thermal degradation of the polymers accumulated in the cells grown in glucose, glucose with valerate and glucose with waste were compared.

  14. Increased accumulation of the lipophilic cation tetraphenylphosphonium+ by cyclopiazonic acid-treated renal epithelial cells

    Pig kidney renal epithelial cells (LLC-PK1) in culture were used to determine the effects of cyclopiazonic acid (CPA) on the uptake of the transmembrane potential probe, [3H]tetraphenylphosphonium bromide (TPP+). CPA had a significant stimulatory effect on TPP+ accumulation, which occurred in a dose-related manner. TPP+ accumulation in the presence of CPA was significantly reduced by high-potassium media (HK) and carbonylcyanide m-chlorophenylhydrazone (CCCP), but neither HK nor the protonophore CCCP, could completely abolish the stimulatory effect of CPA. The apparent transmembrane potential difference, calculated based on the difference in accumulation of TPP+ in low-potassium and HK media, ranged from -55.9 to -85.7 mV for control cells and -89.4 to -109.0 mV for CPA-treated cells (20 mg CPA/I). The mechanism of CPA stimulation of TPP+ accumulation was not known. However, it was hypothesized that the effect could be a result of alterations in ion pumps or altered membrane permeability

  15. Monochloroacetic acid lethality in the rat in relation to lactic acid accumulation in the cerebrospinal fluid

    Potential antidotes for human exposure to monochloroacetic acid (MCA) were evaluated using a rodent model. Dichloroacetic acid (DCA) and phenobarbital (PB) but not ethanol or phenytoin, were found to be effective antidotes to monochloroacetic acid (MCA) in rats. DCA (110 mg/kg, ip), administered to rats 15 minutes after a LD-80 of MCA (80 mg/kg, iv), consistently reduced mortality to 0%, while PB reduced mortality to less than 20%. Both DCA and PB were found to be similarly effective in mice. The hypothesis that PB reduces mortality in MCA treated rats by altering the metabolic disposition of MCA was evaluated and rejected. Administration of PB to rats treated with a lethal dose of [14C]MCA did not alter the concentrations of MCA or its metabolites in plasma or cerebrospinal fluid (CSF), or the extent of covalent binding between radioactivity equivalent to [14C]MCA and brain proteins. The relationship between altered blood-brain barrier permeability and death in MCA treated rats was investigated. Treatment with MCA (80 mg/kg, iv) was associated with a significant (50%) increase in the permeability of the rat blood-brain barrier to [125I]BSA. The effect was not altered by treatment with PB, however, suggesting that altered blood-brain barrier permeability does not have an important role in the lethal effect of MCA in rats. The effect of MCA on brain carbohydrate metabolism in vivo was investigated. CSF and blood lactic acid concentrations increased in MCA treated rats, and the increase in CSF levels was dose related. In individual MCA treated rats, CSF lactate concentrations paralleled the time course of ataxia and a discrete threshold for death (18 mmol/L) was observed. The relationship between excess brain lactate levels and death in MCA treated rats was investigated further

  16. Trade-Off between Growth and Carbohydrate Accumulation in Nutrient-Limited Arthrospira sp. PCC 8005 Studied by Integrating Transcriptomic and Proteomic Approaches.

    Orily Depraetere

    Full Text Available Cyanobacteria have a strong potential for biofuel production due to their ability to accumulate large amounts of carbohydrates. Nitrogen (N stress can be used to increase the content of carbohydrates in the biomass, but it is expected to reduce biomass productivity. To study this trade-off between carbohydrate accumulation and biomass productivity, we characterized the biomass productivity, biomass composition as well as the transcriptome and proteome of the cyanobacterium Arthrospira sp. PCC 8005 cultured under N-limiting and N-replete conditions. N limitation resulted in a large increase in the carbohydrate content of the biomass (from 14 to 74% and a decrease in the protein content (from 37 to 10%. Analyses of fatty acids indicated that no lipids were accumulated under N-limited conditions. Nevertheless, it did not affect the biomass productivity of the culture up to five days after N was depleted from the culture medium. Transcriptomic and proteomic analysis indicated that de novo protein synthesis was down-regulated in the N-limited culture. Proteins were degraded and partly converted into carbohydrates through gluconeogenesis. Cellular N derived from protein degradation was recycled through the TCA and GS-GOGAT cycles. In addition, photosynthetic energy production and carbon fixation were both down-regulated, while glycogen synthesis was up-regulated. Our results suggested that N limitation resulted in a redirection of photosynthetic energy from protein synthesis to glycogen synthesis. The fact that glycogen synthesis has a lower energy demand than protein synthesis might explain why Arthrospira is able to achieve a similar biomass productivity under N-limited as under N-replete conditions despite the fact that photosynthetic energy production was impaired by N limitation.

  17. Effect of orthosilicic acid on the accumulation of trace metals by the pond snail Lymnaea stagnalis

    Silicon (Si) has a marked affinity for aluminium (Al(III)), but not other trace metals such as cadmium (Cd(II)) and zinc (Zn(II)). Exogenous orthosilicic acid (Si(OH)4) ameliorates the toxicity of Al(III) to the pond snail Lymnaea stagnalis, but its mechanism of action is unclear. Here, studies were conducted to ascertain whether interaction between orthosilicic acid and Al(III) occurs in the water column to prevent Al(III) uptake, or in the tissues to reduce the toxicity of accumulated metal. Silicon did not reduce the accumulation of Al(III) by the digestive gland (the main 'sink' for trace metals in L. stagnalis) following exposure of the snail for 30 days to 500 μg l-1 added Al(III) and 13-fold molar excess of orthosilicic acid. However, Si concentrations correlated well with Al(III) levels in the digestive gland (R2=0.77), giving a ratio of 2.5:1 (Al(III):Si). Exposure to Zn(II) or Cd(II) and 13-fold molar excess of orthosilicic acid did not prevent uptake of these metals, or result in a correlation between metal and Si concentrations of the snail digestive gland. These data show that aquated orthosilicic acid does not prevent Al(III) accumulation by L. stagnalis. However, following exposure, the ratio of Al(III) to Si in the digestive gland is suggestive of the early formation of hydroxyaluminosilicates, probably proto-imogolites (2-3:1 Al(III):Si). Whether hydroxyaluminates are formed ex vivo in the water column and taken up by snails into the digestive gland, or formed in situ within the digestive gland remains to be established. Either way, orthosilicic acid clearly prevents the in vivo toxicity of Al(III) rather than reducing its uptake. Silicon appears to have an important role in the handling Al(III) by the pond snail which may also have wider relevance in understanding the role of Si in ameliorating Al(III) toxicity

  18. Ascorbic acid accumulates as a defense response to Turnip mosaic virus in resistant Brassica rapa cultivars.

    Fujiwara, Ayaka; Togawa, Satoko; Hikawa, Takahiro; Matsuura, Hideyuki; Masuta, Chikara; Inukai, Tsuyoshi

    2016-07-01

    We initially observed that Brassica rapa cultivars containing the Turnip mosaic virus (TuMV) resistance gene, Rnt1-1, accumulated a high level of endogenous ascorbic acid (AS) and dehydroascobic acid (DHA) when infected with TuMV. We here hypothesized a possible contribution of an elevated level of AS+DHA (TAA) to the Rnt1-1-mediated resistance, and conducted a series of experiments using B. rapa and Arabidopsis plants. The application of l-galactose (the key substrate in AS synthesis) to a susceptible cultivar could increase the TAA level ~2-fold, and simultaneously lead to some degree of enhanced viral resistance. To confirm some positive correlation between TAA levels and viral resistance, we analyzed two Arabidopsis knockout mutants (ao and vtc1) in the AS pathways; the TAA levels were significantly increased and decreased in ao and vtc1 plants, respectively. While the ao plants showed enhanced resistance to TuMV, vtc1 plants were more susceptible than the control, supporting our hypothesis. When we analyzed the expression profiles of the genes involved in the AS pathways upon TuMV infection, we found that the observed TAA increase was mainly brought about by the reduction of AS oxidation and activation of AS recycling. We then investigated the secondary signals that regulate endogenous TAA levels in response to viral infection, and found that jasmonic acid (JA) might play an important role in TAA accumulation. In conclusion, we reason that the elevated TAA accumulation in B. rapa plants would be at least partly mediated by the JA-dependent signaling pathway and may significantly contribute to viral resistance. PMID:27255930

  19. Comparative proteomic analysis of engineered Saccharomyces cerevisiae with enhanced free fatty acid accumulation.

    Chen, Liwei; Lee, Jaslyn Jie Lin; Zhang, Jianhua; Chen, Wei Ning

    2016-02-01

    The engineered Saccharomyces cerevisiae strain △faa1△faa4 [Acot5s] was demonstrated to accumulate more free fatty acids (FFA) previously. Here, comparative proteomic analysis was performed to get a global overview of metabolic regulation in the strain. Over 500 proteins were identified, and 82 of those proteins were found to change significantly in the engineered strains. Proteins involved in glycolysis, acetate metabolism, fatty acid synthesis, TCA cycle, glyoxylate cycle, the pentose phosphate pathway, respiration, transportation, and stress response were found to be upregulated in △faa1△faa4 [Acot5s] as compared to the wild type. On the other hand, proteins involved in glycerol, ethanol, ergosterol, and cell wall synthesis were downregulated. Taken together with our metabolite analysis, our results showed that the disruption of Faa1 and Faa4 and expression of Acot5s in the engineered strain △faa1△faa4 [Acot5s] not only relieved the feedback inhibition of fatty acyl-CoAs on fatty acid synthesis, but also caused a major metabolic rearrangement. The rearrangement redirected carbon flux toward the pathways which generate the essential substrates and cofactors for fatty acid synthesis, such as acetyl-CoA, ATP, and NADPH. Therefore, our results help shed light on the mechanism for the increased production of fatty acids in the engineered strains, which is useful in providing information for future studies in biofuel production. PMID:26450510

  20. ACCUMULATION OF POLYHYDROXYALKANOIC ACIDS BY AZOTOBACTER CHROOCOCCUM MAL-201 FROM ORGANIC WASTE

    Soma Pal Saha; A. Patra; P. B. Ghosh; A.K. Paul

    2013-01-01

    Azotobacter chroococcum MAL-201 (MTCC 3853), a free-living nitrogen-fixing bacterium accumulated intracellular poly(3-hydroxybutyric acid) [P(3HB)] accounting 69% of cell dry weight (CDW) when grown in nitrogrn-free Stockdale medium containing 2% (w/v) glucose. It also produced copolymer of poly(3-hydroxybutyrate co-3-hydroxyvalerate) [P(3HB-co-3HV)] using glucose as primary carbon source and valerate cas cosubstrate. To make the polymer production cost effective four types of waste material ...

  1. Determination of dopamine with improved sensitivity by exploiting an accumulation effect at a nano-gold electrode modified with poly(sulfosalicylic acid)

    We describe a glassy carbon electrode modified with nano-gold and a film of poly(sulfosalicylic acid) that was obtained by electropolymerization of sulfosalicylic acid. The electrochemical characteristics of the electrode were investigated by using (a) the anionic hexacyanoferrate, and (b) the cationic ruthenium-trisbipyridyl systems as redox probes. The electrode displayed selective and enhanced electroanalytical response towards dopamine (DA), obviously because DA (which is cationic) is accumulated at the electrode, while anions such as ascorbic acid (AA) do not and in fact are being repelled. A 2000-fold molar excess of AA is tolerated after a 120-s accumulation time followed by stripping detection at pH 6. 5. Response is linear with the concentration of DA in the range from 0. 05 to 5 μM, and the detection limit is 7 nM (at an S/N of 3) even in the presence of 100 μM concentrations of AA. (author)

  2. Vermicompost humic acids modulate the accumulation and metabolism of ROS in rice plants.

    García, Andrés Calderín; Santos, Leandro Azevedo; de Souza, Luiz Gilberto Ambrósio; Tavares, Orlando Carlos Huertas; Zonta, Everaldo; Gomes, Ernane Tarcisio Martins; García-Mina, José Maria; Berbara, Ricardo Luis Louro

    2016-03-15

    This work aims to determine the reactive oxygen species (ROS) accumulation, gene expression, anti-oxidant enzyme activity, and derived effects on membrane lipid peroxidation and certain stress markers (proline and malondialdehyde-MDA) in the roots of unstressed and PEG-stressed rice plants associated with vermicompost humic acid (VCHA) application. The results show that the application of VCHA to the roots of unstressed rice plants caused a slight but significant increase in root ROS accumulation and the gene expression and activity of the major anti-oxidant enzymes (superoxide dismutase and peroxidase). This action did not have negative effects on root development, and an increase in both root growth and root proliferation occurred. However, the root proline and MDA concentrations and the root permeability results indicate the development of a type of mild stress associated with VCHA application. When VCHA was applied to PEG-stressed plants, a clear alleviation of the inhibition in root development linked to PEG-mediated osmotic stress was observed. This was associated with a reduction in root ROS production and anti-oxidant enzymatic activity caused by osmotic stress. This alleviation of stress caused by VCHA was also reflected as a reduction in the PEG-mediated concentration of MDA in the root as well as root permeability. In summary, the beneficial action of VCHA on the root development of unstressed or PEG-stressed rice plants clearly involves the modulation of ROS accumulation in roots. PMID:26851887

  3. Accumulation of Flavonols over Hydroxycinnamic Acids Favors Oxidative Damage Protection under Abiotic Stress

    Martinez, Vicente; Mestre, Teresa C.; Rubio, Francisco; Girones-Vilaplana, Amadeo; Moreno, Diego A.; Mittler, Ron; Rivero, Rosa M.

    2016-01-01

    Efficient detoxification of reactive oxygen species (ROS) is thought to play a key role in enhancing the tolerance of plants to abiotic stresses. Although multiple pathways, enzymes, and antioxidants are present in plants, their exact roles during different stress responses remain unclear. Here, we report on the characterization of the different antioxidant mechanisms of tomato plants subjected to heat stress, salinity stress, or a combination of both stresses. All the treatments applied induced an increase of oxidative stress, with the salinity treatment being the most aggressive, resulting in plants with the lowest biomass, and the highest levels of H2O2 accumulation, lipid peroxidation, and protein oxidation. However, the results obtained from the transcript expression study and enzymatic activities related to the ascorbate-glutathione pathway did not fully explain the differences in the oxidative damage observed between salinity and the combination of salinity and heat. An exhaustive metabolomics study revealed the differential accumulation of phenolic compounds depending on the type of abiotic stress applied. An analysis at gene and enzyme levels of the phenylpropanoid metabolism concluded that under conditions where flavonols accumulated to a greater degree as compared to hydroxycinnamic acids, the oxidative damage was lower, highlighting the importance of flavonols as powerful antioxidants, and their role in abiotic stress tolerance. PMID:27379130

  4. Transcripts for genes encoding soluble acid invertase and sucrose synthase accumulate in root tip and cortical cells containing mycorrhizal arbuscules.

    Blee, Kristopher A; Anderson, Anne J

    2002-09-01

    Arbuscule formation by the arbuscular mycorrhizal fungus Glomus intraradices (Schenck & Smith) was limited to cortical cells immediately adjacent to the endodermis. Because these cortical cells are the first to intercept photosynthate exiting the vascular cylinder, transcript levels for sucrose metabolizing-enzymes were compared between mycorrhizal and non-mycorrhizal roots. The probes corresponded to genes encoding a soluble acid invertase with potential vacuolar targeting, which we generated from Phaseolus vulgaris roots, a Rhizobium-responsive sucrose synthase of soybean and a cell wall acid invertase of carrot. Transcripts in non-mycorrhizal roots were developmentally regulated and abundant in the root tips for all three probes but in differentiated roots of P. vulgaris they were predominantly located in phloem tissues for sucrose synthase or the endodermis and phloem for soluble acid invertase. In mycorrhizal roots increased accumulations of transcripts for sucrose synthase and vacuolar invertase were both observed in the same cortical cells bearing arbuscules that fluoresce. There was no effect on the expression of the cell wall invertase gene in fluorescent carrot cells containing arbuscules. Thus, it appears that presence of the fungal hyphae in the fluorescent arbusculated cell stimulates discrete alterations in expression of sucrose metabolizing enzymes to increase the sink potential of the cell. PMID:12175013

  5. Electrochemical antimony removal from accumulator acid: Results from removal trials in laboratory cells

    Highlights: ► In non-divided cells, antimony did not deposit at cathode due to oxidation of Sb(III) at anode. ► Copper and graphite were found to be the most suitable electrode materials for antimony deposition. ► Sb species covering electrode lowers deposition efficiency with time. ► Thus, periodical renewal of cathode material is necessary. ► Calculated specific electroenergy consumption was relatively high. ► In contrast, absolute energy consumption was low due to small quantities of antimony removed. - Abstract: Regeneration of spent accumulator acid could be an alternative process for crystallization, neutralisation and disposal. Therefore, for the first time in a study of the possibilities of electrochemical removal of antimony and accumulator acid regeneration on a laboratory scale, two synthetic and several real systems containing sulfuric acid of concentrations ranging between 28% and 36%, and antimony species were tested. Discontinuous electrochemical reactors with anion exchange membranes were successfully used in these experiments, which were conducted at a temperature of 35 °C. Removal of antimony using cells that were not divided by a separator, however, was not possible. In selected experiments, by varying the electrode material, type of electrolyte, and cell current, the concentration of antimony could be reduced from the range of 5 ppm to 0.15 ppm. This resulted in current efficiencies between 0.00002% and 0.001%, and in specific electroenergy demands between 100 Wh L−1 and 2000 Wh L−1. In other experiments on substances with antimony contents up to 3500 mg L−1, the current efficiencies obtained were more than a thousandfold higher. In contrast to the formally high relative energy consumption parameters absolute demand parameters are relatively small and favour the electrochemical method in small scale application. Besides plate electrodes, 3D-cathodes were used. Copper- and graphite cathodes produced the best results.

  6. Presystemic branchial metabolism limits di-2-ethylhexyl phthalate accumulation in fish

    Despite the high lipophilicity of di-2-ethylhexyl phthalate (DEHP), fish do not extensively accumulate this ubiquitous environmental contaminant. Experiments with rainbow trout (Salmo gairdneri) fitted with an indwelling cannula showed that the majority of [14C]DEHP did not reach the systemic circulation of the fish, but was present in the exposure water as metabolites. Pharmacokinetic analysis, using a compartmental model that included the gill as a separate metabolic compartment, indicated that DEHP was extensively metabolized as it diffused from water to blood. Isolated perfused gill arches of trout metabolized DEHP in the exposure bath to monoethylhexyl phthalate, demonstrating the ability of the gill to prevent DEHP entry into the fish. The relationship between metabolic clearance and tissue perfusion further suggests that metabolism in the gill can play an important role in determining the accumulation and toxicity of organic chemical pollutants in fish

  7. Jasmonic Acid Effect on the Fatty Acid and Terpenoid Indole Alkaloid Accumulation in Cell Suspension Cultures of Catharanthus roseus

    Guitele Dalia Goldhaber-Pasillas

    2014-07-01

    Full Text Available The stress response after jasmonic acid (JA treatment was studied in cell suspension cultures of Catharanthus roseus. The effect of JA on the primary and secondary metabolism was based on changes in profiles of fatty acids (FA and terpenoid indole alkaloids (TIA. According to multivariate data analyses (MVDA, three major time events were observed and characterized according to the variations of specific FA and TIA: after 0–30 min of induction FA such as C18:1, C20:0, C22:0 and C24:0 were highly induced by JA; 90–360 min after treatment was characterized by variations of C14:0 and C15:0; and 1440 min after induction JA had the largest effect on both group of metabolites were C18:1, C18:2, C18:3, C16:0, C20:0, C22:0, C24:0, catharanthine, tabersonine-like 1, serpentine, tabersonine and ajmalicine-like had the most significant variations. These results unambiguously demonstrate the profound effect of JA particularly on the accumulation of its own precursor, C18:3 and the accumulation of TIA, which can be considered as late stress response events to JA since they occurred only after 1440 min. These observations show that the early events in the JA response do not involve the de novo biosynthesis of neither its own precursor nor TIA, but is due to an already present biochemical system.

  8. Jasmonic acid effect on the fatty acid and terpenoid indole alkaloid accumulation in cell suspension cultures of Catharanthus roseus.

    Goldhaber-Pasillas, Guitele Dalia; Mustafa, Natali Rianika; Verpoorte, Robert

    2014-01-01

    The stress response after jasmonic acid (JA) treatment was studied in cell suspension cultures of Catharanthus roseus. The effect of JA on the primary and secondary metabolism was based on changes in profiles of fatty acids (FA) and terpenoid indole alkaloids (TIA). According to multivariate data analyses (MVDA), three major time events were observed and characterized according to the variations of specific FA and TIA: after 0-30 min of induction FA such as C18:1, C20:0, C22:0 and C24:0 were highly induced by JA; 90-360 min after treatment was characterized by variations of C14:0 and C15:0; and 1440 min after induction JA had the largest effect on both group of metabolites were C18:1, C18:2, C18:3, C16:0, C20:0, C22:0, C24:0, catharanthine, tabersonine-like 1, serpentine, tabersonine and ajmalicine-like had the most significant variations. These results unambiguously demonstrate the profound effect of JA particularly on the accumulation of its own precursor, C18:3 and the accumulation of TIA, which can be considered as late stress response events to JA since they occurred only after 1440 min. These observations show that the early events in the JA response do not involve the de novo biosynthesis of neither its own precursor nor TIA, but is due to an already present biochemical system. PMID:25029072

  9. Strigolactone regulates anthocyanin accumulation, acid phosphatases production and plant growth under low phosphate condition in Arabidopsis.

    Shinsaku Ito

    Full Text Available Phosphate is an essential macronutrient in plant growth and development; however, the concentration of inorganic phosphate (Pi in soil is often suboptimal for crop performance. Accordingly, plants have developed physiological strategies to adapt to low Pi availability. Here, we report that typical Pi starvation responses in Arabidopsis are partially dependent on the strigolactone (SL signaling pathway. SL treatment induced root hair elongation, anthocyanin accumulation, activation of acid phosphatase, and reduced plant weight, which are characteristic responses to phosphate starvation. Furthermore, the expression profile of SL-response genes correlated with the expression of genes induced by Pi starvation. These results suggest a potential overlap between SL signaling and Pi starvation signaling pathways in plants.

  10. Effect of Nitrogen Sources on the Growth and Docosahexaenoic Acid Accumulation in Crypthecodinium cohnii

    Wang Jufang; Wu Haizhen; Liang Shizhong; Chen Feng

    2002-01-01

    The effect of various nitrogen sources on the growth and docosahexaenoic acid (DHA) yield is determined in Crypthecodinium cohnii ATCC30556. Single nitrogen tryptone and peptone are suitable to growth, the dry weight biomass is up to 2.78 g/L and 2.70g/L respectively on medium containing 0.34 g/L nitrogen. Peptone is a favorable nitrogen source for DHA accumulation, DHA yield increases up to 338.56 mg/L. Using peptone and KNO3 as a multiple nitrogen source, the highest biomass and DHA yield are obtained from media containing 0.34 g/L nitrogen in which the ratio of peptone-N:NO3--N is 1:2,and the biomass and DHA yield are 2.98 g/L(DW) and 527.97mg/L respectively.

  11. Retinoic acid induces nuclear accumulation of Raf1 during differentiation of HL-60 cells

    Smith, James; Bunaciu, Rodica P.; Reiterer, Gudrun [Department of Biomedical Sciences, T4-008 VRT, Cornell University, Ithaca, NY 14853 (United States); Coder, David; George, Thaddeus [Amnis Corporation, Seattle, Washington (United States); Asaly, Michael [Department of Biomedical Sciences, T4-008 VRT, Cornell University, Ithaca, NY 14853 (United States); Yen, Andrew, E-mail: ay13@cornell.edu [Department of Biomedical Sciences, T4-008 VRT, Cornell University, Ithaca, NY 14853 (United States)

    2009-08-01

    All trans-retinoic acid (RA) is a standard therapeutic agent used in differentiation induction therapy treatment of acute promyelocytic leukemia (APL). RA and its metabolites use a diverse set of signal transduction pathways during the differentiation program. In addition to the direct transcriptional targets of the nuclear RAR and RXR receptors, signals derived from membrane receptors and the Raf-MEK-ERK pathway are required. Raf1 phosphorylation and the prolonged activation of Raf1 persisting during the entire differentiation process are required for RA-dependent differentiation of HL-60 cells. Here we identify a nuclear redistribution of Raf1 during the RA-induced differentiation of HL-60 cells. In addition, the nuclear accumulation of Raf1 correlates with an increase in Raf1 phosphorylated at serine 621. The serine 621 phosphorylated Raf1 is predominantly localized in the nucleus. The RA-dependent nuclear accumulation of Raf1 suggests a novel nuclear role for Raf1 during the differentiation process.

  12. Salicylic acid reduces napropamide toxicity by preventing its accumulation in rapeseed (Brassica napus L.).

    Cui, Jing; Zhang, Rui; Wu, Guo Lin; Zhu, Hong Mei; Yang, Hong

    2010-07-01

    Napropamide is a widely used herbicide for controlling weeds in crop production. However, extensive use of the herbicide has led to its accumulation in ecosystems, thus causing toxicity to crops and reducing crop production and quality. Salicylic acid (SA) plays multiple roles in regulating plant adaptive responses to biotic and environmental stresses. However, whether SA regulates plant response to herbicides (or pesticides) was unknown. In this study, we investigated the effect of SA on herbicide napropamide accumulation and biological processes in rapeseed (Brassica napus). Plants exposed to 8 mg kg(-1) napropamide showed growth stunt and oxidative damage. Treatment with 0.1 mM SA improved growth and reduced napropamide levels in plants. Treatment with SA also decreased the abundance of O (2) (-.) and H(2)O(2) as well as activities of superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX), and increased activities of guaiacol peroxidase (POD) and glutathione-S-transferase (GST) in napropamide-exposed plants. Analysis of SOD, CAT, and POD activities using nondenaturing polyacrylamide gel electrophoresis (PAGE) confirmed the results. These results may help to understand how SA regulates plant response to organic contaminants and provide a basis to control herbicide/pesticide contamination in crop production. PMID:19967348

  13. Accumulation of some metals by legumes and their extractability from acid mine spoils. [USA - Alabama

    Taylor, R.W.; Ibeabuchi, I.O.; Sistani, K.R.; Shuford, J.W. (Alabama A M University, Normal, AL (USA). Dept. of Plant and Soil Science)

    A greenhouse study was conducted to investigate the growth (dry matter yield) of selected legume cover crops; phytoaccumulation of metals such as Zn, Mn, Pb, Cu, Ni, and Al; the extractability of heavy metals from three different Alabama acid mine spoils. The spoils were amended based on soil test recommended levels of N, P, K, Ca and Mg prior to plant growth. Metals were extracted by three extractants (Mehlich 1, DTPA, and 0.1 M HCl) and values correlated with their accumulation by the selected legumes. Among the cover crops, kobe lespedeza {ital Lespedeza striata} (Thung.) Hook and Arn, sericea lespedeza {ital Lespedeza cuneata} (Dum.) G. Don, and red clover (Trifolium pratense L.) did not survive the stressful conditions of the spoils. However, cowpea (Vigna unguiculata L.) followed by Bragg' soybean {ital Glycine max} (L.) Merr. generally produced the highest dry matter yield while accumulating the largest quantity of metals, except Al, from spoils. The extractability of most metals from the spoils was generally in the order of: 0.1 MHCl {gt} DTPA. Mehlich 1 did not extract Pb and 0.1 M HCl did not extract Ni, whereas DTPA extracted all the metals in a small amount relative to HCl and Mehlich 1. All the extractants were quite effective in removing plant-available Zn from the spoils. In general, the extractants' ability to predict plant-available metals depended on the crop species, spoil type, and extractant used. 28 refs., 4 tabs.

  14. Copper accumulation in vineyard soils: Rhizosphere processes and agronomic practices to limit its toxicity.

    Brunetto, Gustavo; Bastos de Melo, George Wellington; Terzano, Roberto; Del Buono, Daniele; Astolfi, Stefania; Tomasi, Nicola; Pii, Youry; Mimmo, Tanja; Cesco, Stefano

    2016-11-01

    Viticulture represents an important agricultural practice in many countries worldwide. Yet, the continuous use of fungicides has caused copper (Cu) accumulation in soils, which represent a major environmental and toxicological concern. Despite being an important micronutrient, Cu can be a potential toxicant at high concentrations since it may cause morphological, anatomical and physiological changes in plants, decreasing both food productivity and quality. Rhizosphere processes can, however, actively control the uptake and translocation of Cu in plants. In particular, root exudates affecting the chemical, physical and biological characteristics of the rhizosphere, might reduce the availability of Cu in the soil and hence its absorption. In addition, this review will aim at discussing the advantages and disadvantages of agronomic practices, such as liming, the use of pesticides, the application of organic matter, biochar and coal fly ashes, the inoculation with bacteria and/or mycorrhizal fungi and the intercropping, in alleviating Cu toxicity symptoms. PMID:27513550

  15. Xanthurenic acid distribution, transport, accumulation and release in the rat brain.

    Gobaille, Serge; Kemmel, Véronique; Brumaru, Daniel; Dugave, Christophe; Aunis, Dominique; Maitre, Michel

    2008-05-01

    Tryptophan metabolism through the kynurenine pathway leads to several neuroactive compounds, including kynurenic and picolinic acids. Xanthurenic acid (Xa) has been generally considered as a substance with no physiological role but possessing toxic and apoptotic properties. In the present work, we present several findings which support a physiological role for endogenous Xa in synaptic signalling in brain. This substance is present in micromolar amounts in most regions of the rat brain with a heterogeneous distribution. An active vesicular synaptic process inhibited by bafilomycin and nigericin accumulates xanthurenate into pre-synaptic terminals. A neuronal transport, partially dependant on adenosine 5'-triphosphate (ATP), sodium and chloride ions exists in NCB-20 neurons which could participate in the clearance of extracellular xanthurenate. Both transports (neuronal and vesicular) are greatly enhanced by the presence of micromolar amounts of zinc ions. Finally, electrical in vivo stimulation of A10-induced Xa release in the extracellular spaces of the rat prefrontal cortex. This phenomenon is reproduced by veratrine, K+ ions and blocked by EGTA and tetrodotoxin. These results strongly argue for a role for Xa in neurotransmission/neuromodulation in the rat brain, thus providing the existence of specific Xa receptors. PMID:18182052

  16. Genome-wide association mapping identifies a new arsenate reductase enzyme critical for limiting arsenic accumulation in plants.

    Dai-Yin Chao

    2014-12-01

    Full Text Available Inorganic arsenic is a carcinogen, and its ingestion through foods such as rice presents a significant risk to human health. Plants chemically reduce arsenate to arsenite. Using genome-wide association (GWA mapping of loci controlling natural variation in arsenic accumulation in Arabidopsis thaliana allowed us to identify the arsenate reductase required for this reduction, which we named High Arsenic Content 1 (HAC1. Complementation verified the identity of HAC1, and expression in Escherichia coli lacking a functional arsenate reductase confirmed the arsenate reductase activity of HAC1. The HAC1 protein accumulates in the epidermis, the outer cell layer of the root, and also in the pericycle cells surrounding the central vascular tissue. Plants lacking HAC1 lose their ability to efflux arsenite from roots, leading to both increased transport of arsenic into the central vascular tissue and on into the shoot. HAC1 therefore functions to reduce arsenate to arsenite in the outer cell layer of the root, facilitating efflux of arsenic as arsenite back into the soil to limit both its accumulation in the root and transport to the shoot. Arsenate reduction by HAC1 in the pericycle may play a role in limiting arsenic loading into the xylem. Loss of HAC1-encoded arsenic reduction leads to a significant increase in arsenic accumulation in shoots, causing an increased sensitivity to arsenate toxicity. We also confirmed the previous observation that the ACR2 arsenate reductase in A. thaliana plays no detectable role in arsenic metabolism. Furthermore, ACR2 does not interact epistatically with HAC1, since arsenic metabolism in the acr2 hac1 double mutant is disrupted in an identical manner to that described for the hac1 single mutant. Our identification of HAC1 and its associated natural variation provides an important new resource for the development of low arsenic-containing food such as rice.

  17. Engineering alfalfa to accumulate useful caffeic acid derivatives and characterization of hydroxycinnamoyl-CoA transferases from legumes

    Some forages crops, such as red clover, accumulate high levels of caffeic acid derivatives. Oxidation of these o-diphenols to quinones by endogenous polyphenol oxidases (PPOs) and the subsequent reactions of these quinones (probably with endogenous plant proteases) result in a significant reduction ...

  18. Effects of Formulated Fertilizer Synergist on Abscisic Acid Accumulation, Proline Content and Photosynthetic Characteristics of Rice under Drought

    WANG Shao-xian; XIA Shi-tou; PENG Ke-qin; KUANG Feng-chun; CAO Yong; XIAO Lang-tao

    2007-01-01

    To investigate the effects of formulated fertilizer synergist on the drought tolerance in rice, pot experiment was conducted to analyze the photosynthetic characteristics and the accumulation of abscisic acid (ABA) and proline in middle-season rice variety Peiliangyou 93. The synergist could improve the net photosynthetic rate, and coordination between the water loss and the CO2 absorption as well as reduce the harmful effect on photosynthetic process under drought conditions. Under drought, the ABA accumulated massively both in roots and leaves, while the ABA content in roots was far higher than that in leaves. The results indicate that synergist could increase the ABA accumulation, but reduce the proline accumulation in rice plant under drought.

  19. Identifying nitrogen limitations to organic sediments accumulation in various vegetation types of arctic tundra (Hornsund, Svalbard)

    Skrzypek, G.; Wojtuń, B.; Hua, Q.; Richter, D.; Jakubas, D.; Wojczulanis-Jakubas, K.; Samecka-Cymerman, A.

    2015-12-01

    Arctic and subarctic regions play important roles in the global carbon balance. However, nitrogen (N) deficiency is a major constraint for organic carbon sequestration in the High Arctic. Hence, the identification of the relative contributions from different N-sources is critical for understanding the constraints that limit tundra growth. The stable nitrogen composition of the three main N-sources and numerous plants were analyzed in ten tundra types in the Fuglebekken catchment (Hornsund Fjord, Svalbard, 77°N 15°E). The percentage of the total tundra N-pool provided by seabirds' feces (colonially breeding, planktivorous Alle alle), ranged from 0-21% in Patterned-ground tundra to 100% in Ornithocoprophilous tundra. The total N-pool utilized by tundra plants in the studied catchment was built in 36% by birds, 38% by atmospheric deposition, and 26% by N2-fixation. The results clearly show that N-pool in the tundra is significantly supplemented by nesting seabirds. Thus, if they experienced substantial negative environmental pressure associated with climate change, it would adversely influence the tundra N-budget [1]. The growth rates and the sediment thickness (climatic conditions but also by birds' contribution to the tundra N-pool. [1] Skrzypek G, Wojtuń B, Richter D, Jakubas D, Wojczulanis-Jakubas K, Samecka-Cymerman A, 2015. Diversification of nitrogen sources in various tundra vegetation types in the high Arctic. PLoS ONE (in review).

  20. Metformin reduces lipid accumulation in macrophages by inhibiting FOXO1-mediated transcription of fatty acid-binding protein 4

    Objective: The accumulation of lipids in macrophages contributes to the development of atherosclerosis. Strategies to reduce lipid accumulation in macrophages may have therapeutic potential for preventing and treating atherosclerosis and cardiovascular complications. The antidiabetic drug metformin has been reported to reduce lipid accumulation in adipocytes. In this study, we examined the effects of metformin on lipid accumulation in macrophages and investigated the mechanisms involved. Methods and results: We observed that metformin significantly reduced palmitic acid (PA)-induced intracellular lipid accumulation in macrophages. Metformin promoted the expression of carnitine palmitoyltransferase I (CPT-1), while reduced the expression of fatty acid-binding protein 4 (FABP4) which was involved in PA-induced lipid accumulation. Quantitative real-time PCR showed that metformin regulates FABP4 expression at the transcriptional level. We identified forkhead transcription factor FOXO1 as a positive regulator of FABP4 expression. Inhibiting FOXO1 expression with FOXO1 siRNA significantly reduced basal and PA-induced FABP4 expression. Overexpression of wild-type FOXO1 and constitutively active FOXO1 significantly increased FABP4 expression, whereas dominant negative FOXO1 dramatically decreased FABP4 expression. Metformin reduced FABP4 expression by promoting FOXO1 nuclear exclusion and subsequently inhibiting its activity. Conclusions: Taken together, these results suggest that metformin reduces lipid accumulation in macrophages by repressing FOXO1-mediated FABP4 transcription. Thus, metformin may have a protective effect against lipid accumulation in macrophages and may serve as a therapeutic agent for preventing and treating atherosclerosis in metabolic syndrome.

  1. Metformin reduces lipid accumulation in macrophages by inhibiting FOXO1-mediated transcription of fatty acid-binding protein 4

    Song, Jun [Qilu Hospital, Shandong University, Jinan, Shandong (China); Division of Cardiothoracic Surgery, Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, TX (United States); Texas Heart Institute at St. Luke' s Episcopal Hospital, Houston, TX (United States); Ren, Pingping; Zhang, Lin [Division of Cardiothoracic Surgery, Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, TX (United States); Texas Heart Institute at St. Luke' s Episcopal Hospital, Houston, TX (United States); Wang, Xing Li [Qilu Hospital, Shandong University, Jinan, Shandong (China); Division of Cardiothoracic Surgery, Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, TX (United States); Texas Heart Institute at St. Luke' s Episcopal Hospital, Houston, TX (United States); Chen, Li [Qilu Hospital, Shandong University, Jinan, Shandong (China); Shen, Ying H., E-mail: hyshen@bcm.edu [Division of Cardiothoracic Surgery, Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, TX (United States); Texas Heart Institute at St. Luke' s Episcopal Hospital, Houston, TX (United States)

    2010-02-26

    Objective: The accumulation of lipids in macrophages contributes to the development of atherosclerosis. Strategies to reduce lipid accumulation in macrophages may have therapeutic potential for preventing and treating atherosclerosis and cardiovascular complications. The antidiabetic drug metformin has been reported to reduce lipid accumulation in adipocytes. In this study, we examined the effects of metformin on lipid accumulation in macrophages and investigated the mechanisms involved. Methods and results: We observed that metformin significantly reduced palmitic acid (PA)-induced intracellular lipid accumulation in macrophages. Metformin promoted the expression of carnitine palmitoyltransferase I (CPT-1), while reduced the expression of fatty acid-binding protein 4 (FABP4) which was involved in PA-induced lipid accumulation. Quantitative real-time PCR showed that metformin regulates FABP4 expression at the transcriptional level. We identified forkhead transcription factor FOXO1 as a positive regulator of FABP4 expression. Inhibiting FOXO1 expression with FOXO1 siRNA significantly reduced basal and PA-induced FABP4 expression. Overexpression of wild-type FOXO1 and constitutively active FOXO1 significantly increased FABP4 expression, whereas dominant negative FOXO1 dramatically decreased FABP4 expression. Metformin reduced FABP4 expression by promoting FOXO1 nuclear exclusion and subsequently inhibiting its activity. Conclusions: Taken together, these results suggest that metformin reduces lipid accumulation in macrophages by repressing FOXO1-mediated FABP4 transcription. Thus, metformin may have a protective effect against lipid accumulation in macrophages and may serve as a therapeutic agent for preventing and treating atherosclerosis in metabolic syndrome.

  2. Redirection of metabolic flux for high levels of omega-7 monounsaturated fatty acid accumulation in camelina seeds.

    Nguyen, Huu Tam; Park, Hyunwoo; Koster, Karen L; Cahoon, Rebecca E; Nguyen, Hanh T M; Shanklin, John; Clemente, Thomas E; Cahoon, Edgar B

    2015-01-01

    Seed oils enriched in omega-7 monounsaturated fatty acids, including palmitoleic acid (16:1∆9) and cis-vaccenic acid (18:1∆11), have nutraceutical and industrial value for polyethylene production and biofuels. Existing oilseed crops accumulate only small amounts (camelina (Camelina sativa) and soybean (Glycine max) that is dependent on redirection of metabolic flux from the typical ∆9 desaturation of stearoyl (18:0)-acyl carrier protein (ACP) to ∆9 desaturation of palmitoyl (16:0)-acyl carrier protein (ACP) and coenzyme A (CoA). This was achieved by seed-specific co-expression of a mutant ∆9-acyl-ACP and an acyl-CoA desaturase with high specificity for 16:0-ACP and CoA substrates, respectively. This strategy was most effective in camelina where seed oils with ~17% omega-7 monounsaturated fatty acids were obtained. Further increases in omega-7 fatty acid accumulation to 60-65% of the total fatty acids in camelina seeds were achieved by inclusion of seed-specific suppression of 3-keto-acyl-ACP synthase II and the FatB 16:0-ACP thioesterase genes to increase substrate pool sizes of 16:0-ACP for the ∆9-acyl-ACP desaturase and by blocking C18 fatty acid elongation. Seeds from these lines also had total saturated fatty acids reduced to ~5% of the seed oil versus ~12% in seeds of nontransformed plants. Consistent with accumulation of triacylglycerol species with shorter fatty acid chain lengths and increased monounsaturation, seed oils from engineered lines had marked shifts in thermotropic properties that may be of value for biofuel applications. PMID:25065607

  3. The expression of the Cuphea palustris thioesterase CpFatB2 in Yarrowia lipolytica triggers oleic acid accumulation.

    Stefan, Alessandra; Hochkoeppler, Alejandro; Ugolini, Luisa; Lazzeri, Luca; Conte, Emanuele

    2016-01-01

    The conversion of industrial by-products into high-value added compounds is a challenging issue. Crude glycerol, a by-product of the biodiesel production chain, could represent an alternative carbon source for the cultivation of oleaginous yeasts. Here, we developed five minimal synthetic glycerol-based media, with different C/N ratios, and we analyzed the production of biomass and fatty acids by Yarrowia lipolytica Po1g strain. We identified two media at the expense of which Y. lipolytica was able to accumulate ∼5 g L(-1) of biomass and 0.8 g L(-1) of fatty acids (0.16 g of fatty acids per g of dry weight). These optimized media contained 0.5 g L(-1) of urea or ammonium sulfate and 20 g L(-1) of glycerol, and were devoid of yeast extract. Moreover, Y. lipolytica was engineered by inserting the FatB2 gene, coding for the CpFatB2 thioesterase from Cuphea palustris, in order to modify the fatty acid composition towards the accumulation of medium-chain fatty acids. Contrary to the expected, the expression of the heterologous gene increased the production of oleic acid, and concomitantly decreased the level of saturated fatty acids. PMID:26518537

  4. Characterization of major ripening events during softening in grape: turgor, sugar accumulation, abscisic acid metabolism, colour development, and their relationship with growth

    Castellarin, Simone D.; Gambetta, Gregory A.; Wada, Hiroshi; Krasnow, Mark N.; Cramer, Grant R.; Peterlunger, Enrico; Shackel, Kenneth A.; Matthews, Mark A.

    2015-01-01

    Highlight The earliest events in ripening are decreases in turgor, softening, and increases in abscisic acid. Later events integral to regulating colour development include growth, further increases in abscisic acid, and sugar accumulation.

  5. A relaxed eddy accumulation system for measuring vertical fluxes of nitrous acid

    X. Ren

    2011-10-01

    Full Text Available A relaxed eddy accumulation (REA system combined with a nitrous acid (HONO analyzer was developed to measure atmospheric HONO vertical fluxes. The system consists of three major components: (1 a fast-response sonic anemometer measuring both vertical wind velocity and air temperature, (2 a fast-response controlling unit separating air motions into updraft and downdraft samplers by the sign of vertical wind velocity, and (3 a highly sensitive HONO analyzer based on aqueous long path absorption photometry that measures HONO concentrations in the updrafts and downdrafts. A dynamic velocity threshold (±0.5σw, where σw is a standard deviation of the vertical wind velocity was used for valve switching determined by the running means and standard deviations of the vertical wind velocity. Using measured temperature as a tracer and the average values from two field deployments, the flux proportionality coefficient, β, was determined to be 0.42 ± 0.02, in good agreement with the theoretical estimation. The REA system was deployed in two ground-based field studies. In the California Research at the Nexus of Air Quality and Climate Change (CalNex study in Bakersfield, California in summer 2010, measured HONO fluxes appeared to be upward during the day and were close to zero at night. The upward HONO flux was highly correlated to the product of NO2 and solar radiation. During the Biosphere Effects on Aerosols and Photochemistry Experiment (BEARPEX 2009 at Blodgett Forest, California in July 2009, the overall HONO fluxes were small in magnitude and were close to zero. Causes for the different HONO fluxes in the two different environments are briefly discussed.

  6. Glucose phosphorylation is not rate limiting for accumulation of glycogen from glucose in perfused livers from fasted rats

    Incorporation of Glc and Fru into glycogen was measured in perfused livers from 24-h fasted rats using [6-3H]Glc and [U-14C]Fru. For the initial 20 min, livers were perfused with low Glc (2 mM) to deplete hepatic glycogen and were perfused for the following 30 min with various combinations of Glc and Fru. With constant Fru (2 mM), increasing perfusate Glc increased the relative contribution of Glc carbons to glycogen (7.2 +/- 0.4, 34.9 +/- 2.8, and 59.1 +/- 2.7% at 2, 10, and 20 mM Glc, respectively; n = 5 for each). During perfusion with substrate levels seen during refeeding (10 mM Glc, 1.8 mumol/g/min gluconeogenic flux from 2 mM Fru), Fru provided 54.7 +/- 2.7% of the carbons for glycogen, while Glc provided only 34.9 +/- 2.8%, consistent with in vivo estimations. However, the estimated rate of Glc phosphorylation was at least 1.10 +/- 0.11 mumol/g/min, which exceeded by at least 4-fold the glycogen accumulation rate (0.28 +/- 0.04 mumol of glucose/g/min). The total rate of glucose 6-phosphate supply via Glc phosphorylation and gluconeogenesis (2.9 mumol/g/min) exceeded reported in vivo rates of glycogen accumulation during refeeding. Thus, in perfused livers of 24-h fasted rats there is an apparent redundancy in glucose 6-phosphate supply. These results suggest that the rate-limiting step for hepatic glycogen accumulation during refeeding is located between glucose 6-phosphate and glycogen, rather than at the step of Glc phosphorylation or in the gluconeogenic pathway

  7. Prey-induced changes in the accumulation of amino acids and phenolic metabolites in the leaves of Drosera capensis L.

    Kováčik, Jozef; Klejdus, Bořivoj; Stork, František; Hedbavny, Josef

    2012-04-01

    Effect of prey feeding (ants Formica fusca) on the quantitative changes in the accumulation of free amino acids, soluble proteins, phenolic metabolites and mineral nutrients in the leaves of carnivorous plant Drosera capensis was studied. Arginine was the most abundant compound in Drosera leaves, while proline was abundant in ants. The amount of the majority of amino acids and their sum were elevated in the fed leaves after 3 and 21 days, and the same, but with further enhancement after 21 days, was observed in ants. Accumulation of amino acids also increased in young non-fed leaves of fed plants. Soluble proteins decreased in ants, but were not enhanced in fed leaves. This confirms the effectiveness of sundew's enzymatic machinery in digestion of prey and suggests that amino acids are not in situ deposited, but rather are allocated within the plant. The content of total soluble phenols, flavonoids and two selected flavonols (quercetin and kaempferol) was not affected by feeding in Drosera leaves, indicating that their high basal level was sufficient for the plant's metabolism and prey-induced changes were mainly N based. The prey also showed to be an important source of other nutrients besides N, and a stimulation of root uptake of some mineral nutrients is assumed (Mg, Cu, Zn). Accumulation of Ca and Na was not affected by feeding. PMID:21140278

  8. Accumulation fatty acids of in Chlorella vulgaris under heterotrophic conditions in relation to activity of acetyl-CoA carboxylase, temperature, and co-immobilization with Azospirillum brasilense

    Leyva, Luis A.; Bashan, Yoav; Mendoza, Alberto; de-Bashan, Luz E.

    2014-10-01

    The relation between fatty acid accumulation, activity of acetyl-CoA carboxylase (ACC), and consequently lipid accumulation was studied in the microalgae Chlorella vulgaris co-immobilized with the plant growth-promoting bacterium Azospirillum brasilense under dark heterotrophic conditions with Na acetate as a carbon source. In C. vulgaris immobilized alone, cultivation experiments for 6 days showed that ACC activity is directly related to fatty acid accumulation, especially in the last 3 days. In co-immobilization experiments, A. brasilense exerted a significant positive effect over ACC activity, increased the quantity in all nine main fatty acids, increased total lipid accumulation in C. vulgaris, and mitigated negative effects of nonoptimal temperature for growth. No correlation between ACC activity and lipid accumulation in the cells was established for three different temperatures. This study demonstrated that the interaction between A. brasilense and C. vulgaris has a significant effect on fatty acid and lipid accumulation in the microalgae.

  9. Accumulation of fatty acids in Chlorella vulgaris under heterotrophic conditions in relation to activity of acetyl-CoAcarboxylase, temperature, and co-immobilization with Azospirillum brasilense [corrected].

    Leyva, Luis A; Bashan, Yoav; Mendoza, Alberto; de-Bashan, Luz E

    2014-10-01

    The relation between fatty acid accumulation, activity of acetyl-CoA carboxylase (ACC), and consequently lipid accumulation was studied in the microalgae Chlorella vulgaris co-immobilized with the plant growth-promoting bacterium Azospirillum brasilense under dark heterotrophic conditions with Na acetate as a carbon source. In C. vulgaris immobilized alone, cultivation experiments for 6 days showed that ACC activity is directly related to fatty acid accumulation, especially in the last 3 days. In co-immobilization experiments, A. brasilense exerted a significant positive effect over ACC activity, increased the quantity in all nine main fatty acids, increased total lipid accumulation in C. vulgaris, and mitigated negative effects of nonoptimal temperature for growth. No correlation between ACC activity and lipid accumulation in the cells was established for three different temperatures. This study demonstrated that the interaction between A. brasilense and C. vulgaris has a significant effect on fatty acid and lipid accumulation in the microalgae. PMID:25129521

  10. Growth and palmitoleic acid accumulation of filamentous oleaginous microalgae Tribonema minus at varying temperatures and light regimes.

    Wang, Hui; Gao, Lili; Zhou, Wenjun; Liu, Tianzhong

    2016-10-01

    Palmitoleic acid (C16:1Δ9), contributes greatly to human health, industrial chemicals and biodiesel. The filamentous oleaginous microalgae Tribonema sp. has been identified as a highly efficient producer of palmitoleic acid. Temperature and light regime were adapted to regulate the palmitoleic acid content in this study. Strain T. minus was able to grow well at all the tested temperatures, even at 5 °C. The optimum temperature for palmitoleic acid accumulation (54.25 % of total fatty acid) was 25 °C. Moreover, both light intensity and photoperiod affect the growth, lipid content and fatty acid files of T. minus. The culture exposed to 240 μmol photons m(-2) s(-1) with a photoperiod of 24:0 showed the highest biomass (6.87 g L(-1)) and biggest lipid content (61.27 % of dry weight), whereas the most amount of palmitoleic acid (50.47 % of total fatty acid) was detected at 120 μmol photons m(-2) s(-1). These findings make tangible contributions to culture T. minus for commercial production of lipid or palmitoleic acid. PMID:27250652

  11. Saxitoxins and okadaic acid group: accumulation and distribution in invertebrate marine vectors from Southern Chile.

    García, Carlos; Pérez, Francisco; Contreras, Cristóbal; Figueroa, Diego; Barriga, Andrés; López-Rivera, Américo; Araneda, Oscar F; Contreras, Héctor R

    2015-01-01

    Harmful algae blooms (HABs) are the main source of marine toxins in the aquatic environment surrounding the austral fjords in Chile. Huichas Island (Aysén) has an history of HABs spanning more than 30 years, but there is limited investigation of the bioaccumulation of marine toxins in the bivalves and gastropods from the Region of Aysén. In this study, bivalves (Mytilus chilenses, Choromytilus chorus, Aulacomya ater, Gari solida, Tagelus dombeii and Venus antiqua) and carnivorous gastropods (Argobuccinum ranelliformes and Concholepas concholepas) were collected from 28 sites. Researchers analysed the accumulation of STX-group toxins using a LC with a derivatisation post column (LC-PCOX), while lipophilic toxins (OA-group, azapiracids, pectenotoxins and yessotoxins) were analysed using LC-MS/MS with electrospray ionisation (+/-) in visceral (hepatopancreas) and non-visceral tissues (mantle, adductor muscle, gills and foot). Levels of STX-group and OA-group toxins varied among individuals from the same site. Among all tissue samples, the highest concentrations of STX-group toxins were noted in the hepatopancreas in V. antiqua (95 ± 0.1 μg STX-eq 100 g(-1)), T. dombeii (148 ± 1.4 μg STX-eq 100 g(-1)) and G. solida (3232 ± 5.2 μg STX-eq 100 g(-1); p mantle > adductor muscle for the STX-group toxins and foot > digestive gland for the OA-group toxins. These results gave a better understanding of the variability and compartmentalisation of STX-group and OA-group toxins in different bivalve and gastropod species from the south of Chile, and the analyses determined that tissues could play an important role in the biotransformation of STX-group toxins and the retention of OA-group toxins. PMID:25769036

  12. Effects of waste activated sludge and surfactant addition on primary sludge hydrolysis and short-chain fatty acids accumulation.

    Ji, Zhouying; Chen, Guanlan; Chen, Yinguang

    2010-05-01

    This paper focused on the effects of waste activated sludge (WAS) and surfactant sodium dodecylbenzene sulfonate (SDBS) addition on primary sludge (PS) hydrolysis and short-chain fatty acids (SCFA) accumulation in fermentation. The results showed that sludge hydrolysis, SCFA accumulation, NH(4)(+)-N and PO(4)(3-)-P release, and volatile suspended solids (VSS) reduction were increased by WAS addition to PS, which were further increased by the addition of SDBS to the mixture of PS and WAS. Acetic, propionic and valeric acids were the top three SCFA in all experiments. Also, the fermentation liquids of PS, PS+WAS, and PS+WAS+SDBS were added, respectively, to municipal wastewater to examine their effects on biological municipal wastewater treatment, and the enhancement of both wastewater nitrogen and phosphorus removals was observed compared with no fermentation liquid addition. PMID:20096564

  13. Effects of LaCl3 on photosynthesis and the accumulation of tanshinones and salvianolic acids in Salvia miltiorrhiza seedlings

    ZHOU Jie; GUO Lanping; ZHANG Ji; ZHOU Shufeng; YANG Guang; ZHAO Manxi; HUANG Luqi

    2011-01-01

    The effects of LaCl3 on the growth, photosynthetic gas-exchange characteristics, chlorophyll fluorescence, and the accumulation of tanshinones and salvianolic acids in Salvia miltiorrhiza seedlings were investigated. The results showed that the increase in photosynthesis induced by LaCl3 might be attributed to the enhanced stomatal conductance of the leaves and the increased level of the photochemical efficiency of PS Ⅱ. The accumulation of tanshinone IIA and cryptotanshinone was markedly increased with the application of LaCl3 at 20 and 60mg/L, while tanshinone I was only slightly increased. The content of salvianolic acid B was, however, decreased with the treatment of LaCl3at 200 mg/L.

  14. Naturally evolved enhanced Cd tolerance of Dianthus carthusianorum L. is not related to accumulation of thiol peptides and organic acids.

    Wójcik, Małgorzata; Dresler, Sławomir; Plak, Andrzej; Tukiendorf, Anna

    2015-05-01

    Two contrasting ecotypes of Dianthus carthusianorum L., metallicolous (M) and nonmetallicolous (NM), were cultivated in hydroponics at 0-50 μM Cd for 14 days to compare their Cd accumulation, sensitivity and tolerance mechanisms. While both ecotypes contained similar concentrations of Cd in the shoots and roots, the M ecotype was more Cd-tolerant (as measured by fresh weight production and root and leaf viability). Both ecotypes accumulated phytochelatins (PCs) in response to Cd with a higher amount thereof found in the NM ecotype. Concentrations of PCs remained unchanged with increasing Cd concentrations in the root tissues, but their content in the shoots increased. The addition of L-buthionine-sulfoximine (BSO) diminished glutathione (GSH) accumulation and arrested PC production, which increased the sensitivity to Cd of the NM, but not M ecotype. Organic acids (malate and citrate) as well as proline accumulation did not change significantly after Cd exposition and was at the same level in both ecotypes. The enhanced Cd tolerance of the M ecotype of D. carthusianorum cannot be explained in terms of restricted Cd uptake and differential production of PCs, organic acids or proline; some other mechanisms must be involved in its adaptation to the high Cd content in the environment. PMID:25510617

  15. Cd and Ni transport and accumulation in the halophyte Sesuvium portulacastrum: implication of organic acids in these processes.

    Mnasri, Mejda; Ghabriche, Rim; Fourati, Emna; Zaier, Hanen; Sabally, Kebba; Barrington, Suzelle; Lutts, Stanley; Abdelly, Chedly; Ghnaya, Tahar

    2015-01-01

    The implication of organic acids in Cd and Ni translocation was studied in the halophyte species Sesuvium portulacastrum. Citric, fumaric, malic, and ascorbic acids were separated and quantified by HPLC technique in shoots, roots and xylem saps of plants grown on nutrient solutions added with 50 μM Cd, 100 μM Ni and the combination of 50 μM Cd + 100 μM Ni. Results showed that Cd had no significant impact on biomass production while Ni and the combination of both metals drastically affected plant development. Cadmium and Ni concentrations in tissues and xylem sap were higher in plants subjected to individual metal application than those subjected to the combined effect of Cd and Ni suggesting a possible competition between these metals for absorption. Both metals applied separately or in combination induced an increase in citrate concentration in shoots and xylem sap but a decrease of this concentration in the roots. However, a minor relationship was observed between metal application and fumaric, malic, and ascorbic acids. Both observations suggest the implication of citric acid in Cd, Ni translocation and shoot accumulation in S. portulacastrum. The relatively high accumulation of citric acid in xylem sap and shoot of S. portulacastrum could be involved in metal chelation and thus contributes to heavy metal tolerance in this species. PMID:25821455

  16. Cd and Ni transport and accumulation in the halophyte Sesuvium portulacastrum: implication of organic acids in these processes

    Tahar eGhnaya

    2015-03-01

    Full Text Available The implication of organic acids in Cd and Ni translocation was studied in the halophyte species Sesuvium portulacastrum. Citric, fumaric, malic and ascorbic acids were separated and quantified by HPLC technique in shoots, roots and xylem saps of plants grown on nutrient solutions added with 50 µM Cd, 100 µM Ni and the combination of 50 µM Cd + 100 µM Ni. Results showed that Cd had no significant impact on biomass production while Ni and the combination of both metals drastically affected plant development. Cadmium and Ni concentrations in tissues and xylem sap were higher in plants individually exposed to heavy metal application than in those subjected to the combined treatment Cd + Ni, suggesting a possible competition between these metals for absorption. Both metals applied separately or in combination induced an increase in citrate concentration in shoots and xylem sap but a decrease of this concentration in the roots. However a minor relationship was observed between metal application and fumaric, malic and ascorbic acids. Both observations suggest the implication of citric acid in Cd, Ni translocation and shoot accumulation in S. portulacastrum. The relatively high accumulation of citric acid in xylem sap and shoot of S. portulacastrum could be involved in metal chelation and thus contributes to heavy metal tolerance in this species.

  17. Fungal biotransformation of chlorogenic and caffeic acids by Fusarium graminearum: New insights in the contribution of phenolic acids to resistance to deoxynivalenol accumulation in cereals.

    Gauthier, Léa; Bonnin-Verdal, Marie-Noelle; Marchegay, Gisèle; Pinson-Gadais, Laetitia; Ducos, Christine; Richard-Forget, Florence; Atanasova-Penichon, Vessela

    2016-03-16

    Fusarium Head Blight and Gibberella Ear Rot, mainly caused by the fungi Fusarium graminearum and Fusarium culmorum, are two of the most devastating diseases of small-grain cereals and maize. In addition to yield loss, these diseases frequently result in contamination of kernels with toxic type B trichothecenes. The potential involvement of chlorogenic acid in cereal resistance to Fusarium Head Blight and Gibberella Ear Rot and to trichothecene accumulation was the focus of this study. The effects of chlorogenic acid and one of its hydrolyzed products, caffeic acid, on fungal growth and type B trichothecenes biosynthesis were studied using concentrations close to physiological amounts quantified in kernels and a set of F. graminearum and F. culmorum strains. Both chlorogenic and caffeic acids negatively impact fungal growth and mycotoxin production, with caffeic acid being significantly more toxic. Inhibitory efficiencies of both phenolic acids were strain-dependent. To further investigate the antifungal and anti "mycotoxin" effect of chlorogenic and caffeic acids, the metabolic fate of these two phenolic acids was characterized in supplemented F. graminearum broths. For the first time, our results demonstrated the ability of F. graminearum to degrade chlorogenic acid into caffeic, hydroxychlorogenic and protocatechuic acids and caffeic acid into protocatechuic and hydroxycaffeic acids. Some of these metabolic products can contribute to the inhibitory efficiency of chlorogenic acid that, therefore, can be compared as a "pro-drug". As a whole, our data corroborate the contribution of chlorogenic acid to the chemical defense that cereals employ to counteract F. graminearum and its production of mycotoxins. PMID:26812586

  18. Path analysis suggests phytoene accumulation is the key step limiting the carotenoid pathway in white carrot roots

    Carlos Antonio Fernandes Santos

    2005-01-01

    Full Text Available Two F2 carrot (Daucus carota L. populations (orange rooted Brasilia x very dark orange rooted High Carotene Mass - HCM cross and the dark orange rooted cultivated variety B493 x white rooted wild carrot Queen Anne's Lace - QAL cross with very unrelated genetic backgrounds were used to investigate intrinsic factors limiting carotenoid accumulation in carrots by applying phenotypic correlation and path analysis to study the relationships between major root carotenes, root color and several other morphological traits. Most of the correlations between traits were close and agreed in sign between the two populations. Root weight had a moderate to highly significant positive correlation with leaf length, root length and top and middle root diameter. Although phenotypic correlations failed to identify the order of the substrates and products in the carotenoid pathway the correct order of substrates and products (phytoene -> zeta-carotene -> lycopene was identified in the causal diagram of beta-carotene for the Brasilia x HCM population. Path analysis of beta-carotene synthesis in the B493 x QAL population suggested that selection for root carotenes had little effect on plant morphological traits. Causal model of beta-carotene and lycopene in the B493 x QAL population suggested that phytoene synthesis is the key step limiting the carotenoid pathway in white carrots. Path analysis, first presented by Sewall Wright to study quantitative traits, appears to be a powerful statistical approach for the identification of key compounds in complex pathways.

  19. Do acid volatile sulfides (AVS) influence the accumulation of sediment-bound metals to benthic invertebrates under natural field conditions?

    De Jonge, Maarten; Dreesen, Freja; De Paepe, Josefina; Blust, Ronny; Bervoets, Lieven

    2009-06-15

    The present study evaluates the influence of acid volatile sulfides (AVS) on accumulation of sediment-bound metals in benthic invertebrates under natural field conditions. Natural sediments, pore water, surface water, and two species of widespread benthic invertebrates (Chironomus gr. thummi and Tubifex tubifex) were collected from 17 historical polluted Flemish lowland rivers and measured for metal concentrations. Different sediment characteristics were determined (AVS, organic matter, clay content) and multiple regression was used to study their relationship with accumulated metals in the invertebrates. Physical and chemical analysis of the field samples indicated low metal concentrations in the water and pore water, but very high metal concentrations in the sediment and the invertebrates, especially for Pb (5.99 micromol/ g). In general, metal accumulation in chironomids and tubificid worms was most strongly correlated with total metal concentrations in the sediment and sediment metal concentrations normalized for organic matter and clay content. Following the results of the linear regression model, AVS did not turn out to be a significant variable in describing variation in metal accumulation. Our study clearly demonstrates that, in addition to the results gained from experiments under lab conditions, benthic invertebrates can accumulate metals from unspiked field sediments even when there's an excess of AVS. PMID:19603670

  20. Point mutation of the xylose reductase (XR) gene reduces xylitol accumulation and increases citric acid production in Aspergillus carbonarius

    Weyda, István; Lübeck, Mette; Ahring, Birgitte K; Peter S. Lübeck

    2014-01-01

    Aspergillus carbonarius accumulates xylitol when it grows on d-xylose. In fungi, d-xylose is reduced to xylitol by the NAD(P)H-dependent xylose reductase (XR). Xylitol is then further oxidized by the NAD+-dependent xylitol dehydrogenase (XDH). The cofactor impairment between the XR and XDH can lead to the accumulation of xylitol under oxygen-limiting conditions. Most of the XRs are NADPH dependent and contain a conserved Ile-Pro-Lys-Ser motif. The only known naturally occurring NADH-dependent...

  1. Regulation of erucic acid accumulation in oilseed rape (Brassica napus L.). Effects of temperature and abscisic acid.

    Wilmer, J.A.

    1997-01-01

    Vegetable oils are an important commodity world-wide with an annual production of about 70 million tonnes. Oilseed rape is one of the four major crops, providing about 10% of the total production. Quality of vegetable oils is determined by the fatty acid composition of the triacylglycerols (TAG) that constitute such oils. These fatty acids comprise a range of chain lengths and desaturated and oxidised residues. A small group of fatty acids dominates the edible oils which are the predominant p...

  2. Genome-scale metabolic modeling and in silico analysis of lipid accumulating yeast Candida tropicalis for dicarboxylic acid production.

    Mishra, Pranjul; Park, Gyu-Yeon; Lakshmanan, Meiyappan; Lee, Hee-Seok; Lee, Hongweon; Chang, Matthew Wook; Ching, Chi Bun; Ahn, Jungoh; Lee, Dong-Yup

    2016-09-01

    Recently, the bio-production of α,ω-dicarboxylic acids (DCAs) has gained significant attention, which potentially leads to the replacement of the conventional petroleum-based products. In this regard, the lipid accumulating yeast Candida tropicalis, has been recognized as a promising microbial host for DCA biosynthesis: it possess the unique ω-oxidation pathway where the terminal carbon of α-fatty acids is oxidized to form DCAs with varying chain lengths. However, despite such industrial importance, its cellular physiology and lipid accumulation capability remain largely uncharacterized. Thus, it is imperative to better understand the metabolic behavior of this lipogenic yeast, which could be achieved by a systems biological approach. To this end, herein, we reconstructed the genome-scale metabolic model of C. tropicalis, iCT646, accounting for 646 unique genes, 945 metabolic reactions, and 712 metabolites. Initially, the comparative network analysis of iCT646 with other yeasts revealed several distinctive metabolic reactions, mainly within the amino acid and lipid metabolism including the ω-oxidation pathway. Constraints-based flux analysis was, then, employed to predict the in silico growth rates of C. tropicalis which are highly consistent with the cellular phenotype observed in glucose and xylose minimal media chemostat cultures. Subsequently, the lipid accumulation capability of C. tropicalis was explored in comparison with Saccharomyces cerevisiae, indicating that the formation of "citrate pyruvate cycle" is essential to the lipid accumulation in oleaginous yeasts. The in silico flux analysis also highlighted the enhanced ability of pentose phosphate pathway as NADPH source rather than malic enzyme during lipogenesis. Finally, iCT646 was successfully utilized to highlight the key directions of C. tropicalis strain design for the whole cell biotransformation application to produce long-chain DCAs from alkanes. Biotechnol. Bioeng. 2016;113: 1993-2004.

  3. Acidification, heavy metal mobility and nutrient accumulation in the soil-plant system of a revegetated acid mine wasteland.

    Yang, Sheng-Xiang; Liao, Bin; Li, Jin-tian; Guo, Tao; Shu, Wen-Sheng

    2010-08-01

    A revegetation program was established at an extreme acidic and metal-toxic pyrite/copper mine wasteland in Guangdong Province, PR China using a combination of four native grass species and one non-native woody species. It was continued and monitored for 2 y. The emphasis was on acidification, metal mobility and nutrient accumulation in the soil-plant system. Our results showed the following: (i) the acid-forming potential of the mine soils decreased steadily with time, which might be due to plant root-induced changes inhibiting the oxidization of sulphide minerals; (ii) heavy metal extractability (diethylene-triamine-pentaacetic acid-extractable Pb and Zn) in the soils increased with time despite an increase in soil pH, which might be attributed to soil disturbance and plant rhizospheric processes, as well as a consequence of the enhanced metal accumulation in plants over time; and (iii) the vegetation cover increased rapidly with time, and plant development accelerated the accumulation of major nutrients (organic matter, total and ammonium-N, and available P and K). The 2-y field experiment demonstrates that direct seeding/planting of native plant species in combination with lime and manure amelioration is a practical approach to the initial establishment of a self-sustaining vegetation cover on this metalliferous and sulphide-bearing mine wasteland. However, heavy metal accumulation in the soil-plant system should be of great concern, and long-term monitoring of ecological risk must be an integral part of such a restoration scheme. PMID:20580409

  4. Selection for low erucic acid and genetic mapping of loci affecting the accumulation of very long-chain fatty acids in meadowfoam seed storage lipids.

    Gandhi, S D; Kishore, V K; Crane, J M; Slabaugh, M B; Knapp, S J

    2009-06-01

    Erucic acid (22:1(13)) has been identified as an anti-nutritional compound in meadowfoam (Limnanthes alba) and other oilseeds in the Brassicales, a classification which has necessitated the development of low erucic acid cultivars for human consumption. The erucic acid concentrations of meadowfoam wild types (8%-24%) surpass industry standards for human consumption (acid lines and identify loci affecting the accumulation of 22:1(13) and other very long-chain fatty acids (VLCFAs) in meadowfoam seed storage lipids. LE76, a low erucic acid line, was developed by 3 cycles of selection in an ethyl methanesulfonate-treated wildtype population. LE76 produced 3% 22:1(13), threefold less than the M0 population. Wildtype x LE76 F2 populations produced continuous, approximately normal erucic and dienoic acid distributions. Loss-of-function mutations apparently did not segregate and individuals with low 22:1(13) concentrations (acid F2 progeny. Composite interval mapping identified 3 moderately large-effect erucic acid QTL. The low erucic acid parent transmitted favorable alleles for 2 of 3 QTL, suggesting low erucic acid cultivars can be developed by combining favorable alleles transmitted by wildtype and low erucic acid parents. PMID:19483773

  5. The levels of heavy metals in water and all aquatic in Ismailia canal, (Egypt) compared with the international permissible limits and accumulative studies for these metals in biota

    The concentration of Pb, Cd, Cu, Zu, Ni, Fe and Mn were determined in water, and in different organs of fishes, bivalves, snails and plants in Ismailia canal, Egypt. Moreover, accumulation of the investigated heavy metals by aquatic biota in Ismailia canal and the concentration factor values for this accumulation were calculated to qualify the degree of pollution and compare these levels with the international permissible limits. Results showed that Pb, Cd, Cu and Zn were exceeded the permissible limits especially in the industrial area of Abu- Zaabal, Kalubia governorate. The relative order of heavy metal levels in the canal water was: Fe>Mn>Pb>Zn>Ni>Cd>Cu.Accumulation of heavy metals by the aquatic biota was determined. The accumulation of heavy metals by common snails, namely physa acuta and biomphalaria alexandrina and the bivalve oyster Caelatura (caelatura) companyoi was found mainly in the edible parts (soft parts), whereas, the accumulation by their shells, which are mainly formed of calcium carbonate was via adsorption and surface complexation, since all the accumulated heavy metals were released by adding 0.1 M HCl for few minutes . Moreover, accumulation of heavy metals by common plants namely water hyacinth plant (Eichhornia crassipes) and freshwater weeds were determined. It was found that the accumulation of heavy metals was higher in roots than in leaves. On the other hand, the accumulation of heavy metals by common fish namely, Oreochromis niloticus (Nile Tilapia) was measured in its organs : muscles, liver, gills and gonads. It was found that there is variation of distribution of heavy metals among fish organs. Since the high accumulation of heavy metals among the investigated biota, they can be used as biological indicator for pollution of heavy metals in aquatic ecosystem . The average values and standard deviation for all measurements were determined. Data obtained were compared with the permissible concentrations of the environmental protection

  6. Accumulation of Phenolic Compounds and Expression Profiles of Phenolic Acid Biosynthesis-Related Genes in Developing Grains of White, Purple, and Red Wheat

    Ma, Dongyun; Li, Yaoguang; Zhang, Jian; Wang, Chenyang; Qin, Haixia; Ding, Huina; Xie, Yingxin; Guo, Tiancai

    2016-01-01

    Polyphenols in whole grain wheat have potential health benefits, but little is known about the expression patterns of phenolic acid biosynthesis genes and the accumulation of phenolic acid compounds in different-colored wheat grains. We found that purple wheat varieties had the highest total phenolic content (TPC) and antioxidant activity. Among phenolic acid compounds, bound ferulic acid, vanillic, and caffeic acid levels were significantly higher in purple wheat than in white and red wheat,...

  7. Ultraviolet light and ozone stimulate accumulation of salicylic acid, pathogenesis-related proteins and virus resistance in tobacco

    In tobacco (Nicotiana tabacum L. cv. Xanthinc), salicylic acid (SA) levels increase in leaves inoculated by necrotizing pathogens and in healthy leaves located above the inoculated site. Systemic SA increase may trigger disease resistance and synthesis of pathogenesis-related proteins (PR proteins). Here we report that ultraviolet (UV)-C light or ozone induced biochemical responses similar to those induced by necrotizing pathogens. Exposure of leaves to UV-C light or ozone resulted in a transient ninefold increase in SA compared to controls. In addition, in UV-light-irradiated plants, SA increased nearly fourfold to 0.77 μg·g−1 fresh weight in leaves that were shielded from UV light. Increased SA levels were accompanied by accumulation of an SA conjugate and by an increase in the activity of benzoic acid 2-hydroxylase which catalyzes SA biosynthesis. In irradiated and in unirradiated leaves of plants treated with UV light, as well as in plants fumigated with ozone, PR proteins 1a and 1b accumulated. This was paralleled by the appearance of induced resistance to a subsequent challenge with tobacco mosaic virus. The results suggest that UV light, ozone fumigation and tobacco mosaic virus can activate a common signal-transduction pathway that leads to SA and PR-protein accumulation and increased disease resistance. (author)

  8. Some things get better with age: differences in salicylic acid accumulation and defense signaling in young and mature Arabidopsis

    Philip eCarella

    2015-01-01

    Full Text Available In Arabidopsis, much of what we know about the phytohormone salicylic acid (SA and its role in plant defense comes from experiments using young plants. We are interested in understanding why young plants are susceptible to virulent strains of Pseudomonas syringae, while mature plants exhibit a robust defense response known as Age-Related Resistance (ARR. SA-mediated signaling is important for defense in young plants, however, ARR occurs independently of the defense regulators NPR1 and WHY1. Furthermore, intercellular SA accumulation is an important component of ARR, and intercellular washing fluids from ARR-competent plants exhibit antibacterial activity, suggesting that SA acts as an antimicrobial agent in the intercellular space. Young plants accumulate both intracellular and intercellular SA during PAMP- and Effector-Triggered Immunity, however, virulent P. syringae promotes susceptibility by suppressing SA accumulation using the phytotoxin coronatine. Here we outline the hypothesis that mature, ARR-competent Arabidopsis alleviates coronatine-mediated suppression of SA accumulation. We also explore the role of SA in other mature-plant processes such as flowering and senescence, and discuss their potential impact on ARR.

  9. Deleted in Breast Cancer 1 Limits Adipose Tissue Fat Accumulation and Plays a Key Role in the Development of Metabolic Syndrome Phenotype

    Escande, Carlos; Nin, Veronica; Pirtskhalava, Tamar; Chini, Claudia C. S.; Tchkonia, Tamar; Kirkland, James L.; Chini, Eduardo N.

    2015-01-01

    Obesity is often regarded as the primary cause of metabolic syndrome. However, many lines of evidence suggest that obesity may develop as a protective mechanism against tissue damage during caloric surplus and that it is only when the maximum fat accumulation capacity is reached and fatty acid spill

  10. The Citrus transcription factor, CitERF13, regulates citric acid accumulation via a protein-protein interaction with the vacuolar proton pump, CitVHA-c4.

    Li, Shao-jia; Yin, Xue-ren; Xie, Xiu-lan; Allan, Andrew C; Ge, Hang; Shen, Shu-ling; Chen, Kun-song

    2016-01-01

    Organic acids are essential to fruit flavor. The vacuolar H(+) transporting adenosine triphosphatase (V-ATPase) plays an important role in organic acid transport and accumulation. However, less is known of V-ATPase interacting proteins and their relationship with organic acid accumulation. The relationship between V-ATPase and citric acid was investigated, using the citrus tangerine varieties 'Ordinary Ponkan (OPK)' and an early maturing mutant 'Zaoshu Ponkan (ZPK)'. Five V-ATPase genes (CitVHA) were predicted as important to citric acid accumulation. Among the genes, CitVHA-c4 was observed, using a yeast two-hybrid screen, to interact at the protein level with an ethylene response factor, CitERF13. This was verified using bimolecular fluorescence complementation assays. A similar interaction was also observed between Arabidopsis AtERF017 (a CitERF13 homolog) and AtVHA-c4 (a CitVHA-c4 homolog). A synergistic effect on citric acid levels was observed between V-ATPase proteins and interacting ERFs when analyzed using transient over-expression in tobacco and Arabidopsis mutants. Furthermore, the transcript abundance of CitERF13 was concomitant with CitVHA-c4. CitERF13 or AtERF017 over-expression leads to significant citric acid accumulation. This accumulation was abolished in an AtVHA-c4 mutant background. ERF-VHA interactions appear to be involved in citric acid accumulation, which was observed in both citrus and Arabidopsis. PMID:26837571

  11. Methyl Jasmonate and Salicylic Acid Induced Oxidative Stress and Accumulation of Phenolics in Panax ginseng Bioreactor Root Suspension Cultures

    Kee-Yoeup Paek

    2007-03-01

    Full Text Available To investigate the enzyme variations responsible for the synthesis of phenolics, 40 day-old adventitious roots of Panax ginseng were treated with 200 μM methyl jasmonate (MJ or salicylic acid (SA in a 5 L bioreactor suspension culture (working volume 4 L. Both treatments caused an increase in the carbonyl and hydrogen peroxide (H2O2 contents, although the levels were lower in SA treated roots. Total phenolic, flavonoid, ascorbic acid, non-protein thiol (NPSH and cysteine contents and 1,1-diphenyl-2-picrylhydrazyl (DPPH radical reducing activity were increased by MJ and SA. Fresh weight (FW and dry weight (DW decreased significantly after 9 days of exposure to SA and MJ. The highest total phenolics (62%, DPPH activity (40%, flavonoids (88%, ascorbic acid (55%, NPSH (33%, and cysteine (62% contents compared to control were obtained after 9 days in SA treated roots. The activities of glucose 6-phosphate dehydrogenase, phenylalanine ammonia lyase, substrate specific peroxidases (caffeic acid peroxidase, quercetin peroxidase and ferulic acid peroxidase were higher in MJ treated roots than the SA treated ones. Increased shikimate dehydrogenase, chlorogenic acid peroxidase and β-glucosidase activities and proline content were observed in SA treated roots than in MJ ones. Cinnamyl alcohol dehydrogenase activity remained unaffected by both MJ and SA. These results strongly indicate that MJ and SA induce the accumulation of phenolic compounds in ginseng root by altering the phenolic synthesis enzymes.

  12. Stearoyl-CoA desaturase-1 (SCD1 augments saturated fatty acid-induced lipid accumulation and inhibits apoptosis in cardiac myocytes.

    Hiroki Matsui

    Full Text Available Mismatch between the uptake and utilization of long-chain fatty acids in the myocardium leads to abnormally high intracellular fatty acid concentration, which ultimately induces myocardial dysfunction. Stearoyl-Coenzyme A desaturase-1 (SCD1 is a rate-limiting enzyme that converts saturated fatty acids (SFAs to monounsaturated fatty acids. Previous studies have shown that SCD1-deficinent mice are protected from insulin resistance and diet-induced obesity; however, the role of SCD1 in the heart remains to be determined. We examined the expression of SCD1 in obese rat hearts induced by a sucrose-rich diet for 3 months. We also examined the effect of SCD1 on myocardial energy metabolism and apoptotic cell death in neonatal rat cardiac myocytes in the presence of SFAs. Here we showed that the expression of SCD1 increases 3.6-fold without measurable change in the expression of lipogenic genes in the heart of rats fed a high-sucrose diet. Forced SCD1 expression augmented palmitic acid-induced lipid accumulation, but attenuated excess fatty acid oxidation and restored reduced glucose oxidation. Of importance, SCD1 substantially inhibited SFA-induced caspase 3 activation, ceramide synthesis, diacylglycerol synthesis, apoptotic cell death, and mitochondrial reactive oxygen species (ROS generation. Experiments using SCD1 siRNA confirmed these observations. Furthermore, we showed that exposure of cardiac myocytes to glucose and insulin induced SCD1 expression. Our results indicate that SCD1 is highly regulated by a metabolic syndrome component in the heart, and such induction of SCD1 serves to alleviate SFA-induced adverse fatty acid catabolism, and eventually to prevent SFAs-induced apoptosis.

  13. SFH2 regulates fatty acid synthase activity in the yeast Saccharomyces cerevisiae and is critical to prevent saturated fatty acid accumulation in response to haem and oleic acid depletion

    Desfougères, Thomas; Ferreira, Thierry; Bergès, Thierry; Régnacq, Matthieu

    2007-01-01

    Abstract The yeast Saccharomyces cerevisiae is a facultative anaerobic organism. In anaerobiosis, sustained growth relies on the presence of exogenously supplied unsaturated fatty acids and ergosterol that yeast is unable to synthesize in the absence of oxygen or upon haem depletion. In the absence of exogenous supplementation with unsaturated fatty acid, a net accumulation of saturated fatty acid (SFA) is observed that induces significant modification of phospholipid profile [1]. ...

  14. Metabolism of L-malic acid accumulation in Aspergillus flavus%黄曲霉积累L-苹果酸代谢机制初探

    郝夕祥; 刘建军; 赵祥颖; 田延军; 张家祥

    2011-01-01

    L-malic acid is a member of tricarboxylic acid cycle (TCA cycle) in organism, which has widespread applications in food, medical, daily chemical industry, etc. The paper preliminary introduced the metabolic mechanism of L-malic acid in Aspergillus flavus from the aspects of limiting oxygen fermentation, the addition of calcium carbonate, the inhibitor of enzyme in the TCA cycle, glyoxylate cycle and so on. It was concluded that CO2 fixing pathway was the main route accumulating L-malic acid.%L-苹果酸是生物体内三羧酸循环的成员之一,在食品、医药、日用化工等部门具有广泛的用途.文中从限氧发酵、碳酸钙的添加量、乙醛酸循环和TCA循环相应酶的抑制剂几个方面初步探讨黄曲霉积累L-苹果酸的代谢机制,得出CO2固定途径是积累L-苹果酸的主要途径.

  15. Environmental Risk Limits for Ethylene Diamine Tetra Acetic acid (EDTA)

    Kalf DF; Hoop MAGT van den; Rila JP; Posthuma C; Traas TP; SEC

    2003-01-01

    In this report maximum permissible concentration (MPC) and negligible concentration (NC) in water are derived for Ethylene Diamine Tetra Acetic acid (EDTA; CAS No. 64-02-8, EINECS No. 200-573-9), based on the EU risk assessment report for this compound. The Maximum Permissible Concentration (MPC) for the water compartment is 2.2 mg/l, and the Negligible Concentration (NC) is 0.022 mg/l. Calculation of MPCs for sediment or soil is not possible due to complex speciation of EDTA.

  16. Jasmonic acid is involved in the signaling pathway for fungal endophyte-induced volatile oil accumulation of Atractylodes lancea plantlets

    Ren Cheng-Gang

    2012-08-01

    Full Text Available Abstract Background Jasmonic acid (JA is a well-characterized signaling molecule in plant defense responses. However, its relationships with other signal molecules in secondary metabolite production induced by endophytic fungus are largely unknown. Atractylodes lancea (Asteraceae is a traditional Chinese medicinal plant that produces antimicrobial volatiles oils. We incubated plantlets of A. lancea with the fungus Gilmaniella sp. AL12. to research how JA interacted with other signal molecules in volatile oil production. Results Fungal inoculation increased JA generation and volatile oil accumulation. To investigate whether JA is required for volatile oil production, plantlets were treated with JA inhibitors ibuprofen (IBU and nordihydroguaiaretic acid. The inhibitors suppressed both JA and volatile oil production, but fungal inoculation could still induce volatile oils. Plantlets were further treated with the nitric oxide (NO-specific scavenger 2-(4-carboxyphenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide potassium salt (cPTIO, the H2O2 inhibitors diphenylene iodonium (DPI and catalase (CAT, and the salicylic acid (SA biosynthesis inhibitors paclobutrazol and 2-aminoindan-2-phosphonic acid. With fungal inoculation, IBU did not inhibit NO production, and JA generation was significantly suppressed by cPTIO, showing that JA may act as a downstream signal of the NO pathway. Exogenous H2O2 could reverse the inhibitory effects of cPTIO on JA generation, indicating that NO mediates JA induction by the fungus through H2O2-dependent pathways. With fungal inoculation, the H2O2 scavenger DPI/CAT could inhibit JA generation, but IBU could not inhibit H2O2 production, implying that H2O2 directly mediated JA generation. Finally, JA generation was enhanced when SA production was suppressed, and vice versa. Conclusions Jasmonic acid acts as a downstream signaling molecule in NO- and H2O2-mediated volatile oil accumulation induced by endophytic fungus and has

  17. Fatty acid transport protein-2 inhibitor Grassofermata/CB5 protects cells against lipid accumulation and toxicity

    The inhibition of the fatty acid uptake into non-adipose tissues provides an attractive target for prevention of lipotoxicity leading to obesity-associated non-alcoholic fatty liver disease and type 2 diabetes. Fatty acid transport proteins (FATPs) are bifunctional proteins involved in the uptake and activation of fatty acids by esterification with coenzyme A. Here we characterize Grassofermata/CB5, previously identified as a fatty acid uptake inhibitor directed against HsFATP2. The compound was effective in inhibiting the uptake of fatty acids in the low micro-molar range (IC50 8–11 μM) and prevented palmitate-mediated lipid accumulation and cell death in cell lines that are models for intestines, liver, muscle and pancreas. In adipocytes, uptake inhibition was less effective (IC50 58 μM). Inhibition was specific for long chain fatty acids and was ineffective toward medium chain fatty acids, which are transported by diffusion. Kinetic analysis of Grassofermata-dependent FA transport inhibition verified a non-competitive mechanism. By comparison with Grassofermata, several atypical antipsychotic drugs previously implicated as inhibitors of FA uptake were ineffectual. In mice Grassofermata decreased absorption of 13C-oleate demonstrating its potential as a therapeutic agent. - Highlights: • Grassofermata is a small compound inhibitor of FATP2. • Uptake inhibition is specific for long chain fatty acids. • Uptake kinetics shows low specificity for adipocytes compared to other cell types. • Inhibition is by a non-competitive mechanism. • Atypical antipsychotics do not inhibit FA uptake by comparison with Grassofermata

  18. Fatty acid transport protein-2 inhibitor Grassofermata/CB5 protects cells against lipid accumulation and toxicity

    Saini, Nipun; Black, Paul N.; Montefusco, David; DiRusso, Concetta C., E-mail: cdirusso2@unl.edu

    2015-09-25

    The inhibition of the fatty acid uptake into non-adipose tissues provides an attractive target for prevention of lipotoxicity leading to obesity-associated non-alcoholic fatty liver disease and type 2 diabetes. Fatty acid transport proteins (FATPs) are bifunctional proteins involved in the uptake and activation of fatty acids by esterification with coenzyme A. Here we characterize Grassofermata/CB5, previously identified as a fatty acid uptake inhibitor directed against HsFATP2. The compound was effective in inhibiting the uptake of fatty acids in the low micro-molar range (IC{sub 50} 8–11 μM) and prevented palmitate-mediated lipid accumulation and cell death in cell lines that are models for intestines, liver, muscle and pancreas. In adipocytes, uptake inhibition was less effective (IC{sub 50} 58 μM). Inhibition was specific for long chain fatty acids and was ineffective toward medium chain fatty acids, which are transported by diffusion. Kinetic analysis of Grassofermata-dependent FA transport inhibition verified a non-competitive mechanism. By comparison with Grassofermata, several atypical antipsychotic drugs previously implicated as inhibitors of FA uptake were ineffectual. In mice Grassofermata decreased absorption of {sup 13}C-oleate demonstrating its potential as a therapeutic agent. - Highlights: • Grassofermata is a small compound inhibitor of FATP2. • Uptake inhibition is specific for long chain fatty acids. • Uptake kinetics shows low specificity for adipocytes compared to other cell types. • Inhibition is by a non-competitive mechanism. • Atypical antipsychotics do not inhibit FA uptake by comparison with Grassofermata.

  19. Synergistic Accumulative Effect of Salicylic Acid and Dibutyl Phthalate on Paclitaxel Production in Corylus avellana Cell Culture

    Rezaei, A.

    2013-02-01

    Full Text Available Suspension cell cultures of Corylus avellana were challenged with salicylic acid and its combined use with dibutyl phthalate solvent. Salicylic acid with concentrations of 12.5, 25 and 50 mg L–1 and 10% (v/v dibutyl phthalate were used and added on day 8 and 10 of subculture, respectively. The results showed that growth, viability and protein content of cells were decreased by the treatments, compared to control. In all treatments, hydrogen peroxide content and lipid peroxidation rate of cells increased, compared to those of the control cells. Activity of phenylalanine ammonia-lyase increased by salicylic acid and, dibutyl phthalate exaggerated effect of salicylic acid. While flavonoids content decreased by the treatments, paclitaxel content increased significantly. The extracellular paclitaxel was more affected, compared to cell-associated paclitaxel and all treatments increased paclitaxel release and specific yield compared to that of the control. The most production of paclitaxel and specific yield of it were observed under effect of combined use of salicylic acid (50 mg L–1 and dibutyl phthalate, suggesting a synergistic accumulative effect.

  20. Improved detection of coastal acid sulfate soil hotspots through biomonitoring of metal(loid) accumulation in water lilies (Nymphaea capensis).

    Stroud, Jacqueline L; Collins, Richard N

    2014-07-15

    Anthropogenically disturbed coastal acid sulfate soils along the east coast of Australia, and worldwide, periodically result in the discharge of acid waters containing high concentrations of metals. Identifying priority sites (hotspots) within a catchment for acid sulfate soil remediation activities typically involves long-term monitoring of drainwater chemistry, including the capture of data on unpredictable rain-induced groundwater discharge events. To improve upon this monitoring approach, this study investigated using the water lily (Nymphaea capensis) as a biomonitor of drainage waters to identify hotspots in three acid sulfate soil impacted catchments (83 km(2)) in north-eastern New South Wales, Australia. In one catchment where the location of hotspots was known, water lily lamina concentrations of a suite of metal(loid)s were significantly (pcatchment-scale water lily sampling program undertaken in catchments with unidentified hotspots revealed within catchment variation of plant metal concentrations up to 70-fold. High resolution maps produced from these results, therefore, provided strong evidence for the location of potential hotspots which were confirmed with measurements of drainwater chemistry during rain-induced groundwater discharge events. Median catchment lily accumulation was ca. 160 mg Al kg(-1) and 1,300 mg Fe kg(-1), with hotspots containing up to 6- and 10-fold higher Al and Fe concentrations. These findings suggest that biomonitoring with N. capensis can be an important tool to rapidly identify priority sites for remediation in acid sulfate soil impacted landscapes. PMID:24805963

  1. Identification and expression of a stearoyl-ACP desaturase gene responsible for oleic acid accumulation in Xanthoceras sorbifolia seeds.

    Zhao, Na; Zhang, Yuan; Li, Qiuqi; Li, Rufang; Xia, Xinli; Qin, Xiaowei; Guo, Huihong

    2015-02-01

    Xanthoceras sorbifolia Bunge is an oilseed tree that grows well on barren lands in dry climate. Its seeds contain a large amount of oil rich in oleic acid (18:1(Δ9)) and linoleic acid (18:2(Δ9, 12)). However, the molecular regulation of oil biosynthesis in X. sorbifolia seeds is poorly understood. Stearoyl-ACP desaturase (SAD, EC 1.14.99.6) is a plastid-localized soluble desaturase that catalyzes the conversion of stearic acid (18:0) to oleic acid, which plays a key role in determining the ratio of saturated to unsaturated fatty acids. In this study, a full-length cDNA of XsSAD was isolated from developing X. sorbifolia embryos. The XsSAD open reading frame had 1194-bp, encoding a polypeptide of 397 amino acids. XsSAD expression in Escherichia coli cells resulted in increased 18:1(Δ9) level, confirming the biological activity of the enzyme encoded by XsSAD. XsSAD expression in Arabidopsis ssi2 mutants partially restored the morphological phenotype and effectively increased the 18:1(Δ9) level. The levels of other unsaturated fatty acids synthesized with 18:1(Δ9) as the substrate also increased to some degree. XsSAD in X. sorbifolia had a much higher expression in embryos than in leaves and petals. XsSAD expression also correlated well with the oleic acid, unsaturated fatty acid, and total fatty acid levels in developing embryos. These data suggested that XsSAD determined the synthesis of oleic acid and contributed to the accumulation of unsaturated fatty acid and total oil in X. sorbifolia seeds. A preliminary tobacco rattle virus-based virus-induced gene silencing system established in X. sorbifolia can also be helpful for further analyzing the functions of XsSAD and other oil synthesis-related genes in woody plants. PMID:25528221

  2. The Citrus transcription factor, CitERF13, regulates citric acid accumulation via a protein-protein interaction with the vacuolar proton pump, CitVHA-c4

    Shao-jia Li; Xue-ren Yin; Xiu-lan Xie; Andrew C. Allan; Hang Ge; Shu-ling Shen; Kun-song Chen

    2016-01-01

    Organic acids are essential to fruit flavor. The vacuolar H+ transporting adenosine triphosphatase (V-ATPase) plays an important role in organic acid transport and accumulation. However, less is known of V-ATPase interacting proteins and their relationship with organic acid accumulation. The relationship between V-ATPase and citric acid was investigated, using the citrus tangerine varieties ‘Ordinary Ponkan (OPK)’ and an early maturing mutant ‘Zaoshu Ponkan (ZPK)’. Five V-ATPase genes (CitVHA...

  3. Regulation of erucic acid accumulation in oilseed rape (Brassica napus L.). Effects of temperature and abscisic acid.

    Wilmer, J.A.

    1997-01-01

    Vegetable oils are an important commodity world-wide with an annual production of about 70 million tonnes. Oilseed rape is one of the four major crops, providing about 10% of the total production. Quality of vegetable oils is determined by the fatty acid composition of the triacylglycerols (TAG) tha

  4. Graphene oxide induces plasma membrane damage, reactive oxygen species accumulation and fatty acid profiles change in Pichia pastoris.

    Zhang, Meng; Yu, Qilin; Liang, Chen; Liu, Zhe; Zhang, Biao; Li, Mingchun

    2016-10-01

    During the past couple of years, graphene nanomaterials were extremely popular among the scientists due to the promising properties in many aspects. Before the materials being well applied, we should first focus on their biosafety and toxicity. In this study, we investigated the toxicity of synthesized graphene oxide (GO) against the model industrial organism Pichia pastoris. We found that the synthesized GO showed dose-dependent toxicity to P. pastoris, through cell membrane damage and intracellular reactive oxygen species (ROS) accumulation. In response to these cell stresses, cells had normal unsaturated fatty acid (UFA) levels but increased contents of polyunsaturated fatty acid (PUFA) with up-regulation of UFA synthesis-related genes on the transcriptional level, which made it overcome the stress under GO attack. Two UFA defective strains (spt23Δ and fad12Δ) were used to demonstrate the results above. Hence, this study suggested a close connection between PUFAs and cell survival against GO. PMID:27376352

  5. Effects of Amino Acids Replacing Nitrate on Growth, Nitrate Accumulation, and Macroelement Concentrations in Pak-choi (Brassica chinensis L.)

    2007-01-01

    A hydroponic experiment was carried out to determine the influence of replacing 20% of nitrate-N in nutrient solutions with 20 individual amino acids on growth, nitrate accumulation, and concentrations of nitrogen (N), phosphorus (P), and potassium (K) in pak-choi (Brassica chinensis L.) shoots. When 20% of nitrate-N was replaced with arginine (Arg)compared to the full nitrate treatment, pak-choi shoot fresh and dry weights increased significantly (P ≤ 0.05), but when 20% of nitrate-N was replaced with alanine (Ala), valine (Val), leucine (Leu), isoleucine (Ile), proline (Pro), phenylalanine (Phe), methionine (Met), aspartic acid (Asp), glutamic acid (Glu), lysine (Lys), glycine (Gly), serine (Ser), threonine(Thr), cysteine (Cys), and tyrosine (Tyr), shoot fresh and dry weights decreased significantly (P ≤ 0.05). After replacing 20% of nitrate-N with asparagine (Asn) and glutamine (Gln), shoot fresh and dry weights were unaffected. Compared to the full nitrate treatment, amino acid replacement treatments, except for Cys, Gly, histidine (His), and Arg, significantly reduced (P ≤ 0.05) nitrate concentrations in plant shoots. Except for Cys, Leu, Pro, and Met, total N concentrations in plant tissues of the other amino acid treatments significantly increased (P ≤ 0.05). Amino acids also affected total P and K concentrations, but the effects differed depending on individual amino acids. To improve pak-choi shoot quality, Gln and Asn, due to their insignificant effects on pak-choi growth, their significant reduction in nitrate concentrations, and their increase in macroelement content in plants, may be used to partially replace nitrate-N.

  6. Accumulation and Clearance of Perfluorooctanoic Acid (PFOA) in Current and Former Residents of an Exposed Community

    Seals, Ryan; Bartell, Scott M; Steenland, Kyle

    2010-01-01

    Background Perfluorooctanoic acid (PFOA) is a perfluoroalkyl acid found in > 99% of Americans. Its health effects are unknown. Prior estimates of serum half-life range from 2.3 to 3.8 years. Objectives We assessed the impact of years of residence and years since residing in the study area on serum PFOA concentration in a sample of current and former residents who were exposed to PFOA emissions from an industrial facility in six water districts in West Virginia and Ohio. Methods Serum samples ...

  7. Accumulation and Clearance of Perfluorooctanoic Acid (PFOA) in Current and Former Residents of an Exposed Community

    Seals, Ryan; Bartell, Scott M; Steenland, Kyle

    2010-01-01

    Background: Perfluorooctanoic acid (PFOA) is a perfluoroalkyl acid found in > 99% of Americans. Its health effects are unknown. Prior estimates of serum half-life range from 2.3 to 3.8 years. Objectives: We assessed the impact of years of residence and years since residing in the study area on serum PFOA concentration in a sample of current and former residents who were exposed to PFOA emissions from an industrial facility in six water districts in West Virginia and Ohio. Methods: Serum sampl...

  8. Limiting Current of Oxygen Reduction on Gas-Diffusion Electrodes for Phosphoric Acid Fuel Cells

    Li, Qingfeng; Gang, Xiao; Hjuler, Hans Aage;

    1994-01-01

    on polytetrafluorine-ethyl bonded gas-diffusion electordes in phosphoric acid with and without fluorinated additives. This provides an alternative to estimate the film thickness by combining it with the acid-adsorption measurements and the porosity analysis of the catalyst layer. It was noticed that the limiting...... expression for the limiting current density. The acid-film thickness estimated this way was found to be of 0.1 mum order of magnitude for the two types of electrodes used in phosphoric acid with and without fluorinated additives at 150-degrees-C....

  9. Gibberellic acid alleviates cadmium toxicity by reducing nitric oxide accumulation and expression of IRT1 in Arabidopsis thaliana

    Zhu, Xiao Fang [State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou 310058 (China); Jiang, Tao [Key Laboratory of Conservation Biology for Endangered Wildlife of the Ministry of Education, College of Life Sciences, Zhejiang University, Hangzhou 310058 (China); Wang, Zhi Wei [State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou 310058 (China); Lei, Gui Jie [Key Laboratory of Conservation Biology for Endangered Wildlife of the Ministry of Education, College of Life Sciences, Zhejiang University, Hangzhou 310058 (China); Shi, Yuan Zhi [The Key Laboratory of Tea Chemical Engineering, Ministry of Agriculture, Yunqi Road 1, Hangzhou 310008 (China); Li, Gui Xin, E-mail: guixinli@zju.edu.cn [College of Agronomy and Biotechnology, Zhejiang University, Hangzhou 310058 (China); Zheng, Shao Jian [State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou 310058 (China); Key Laboratory of Conservation Biology for Endangered Wildlife of the Ministry of Education, College of Life Sciences, Zhejiang University, Hangzhou 310058 (China)

    2012-11-15

    Highlights: Black-Right-Pointing-Pointer Cd reduces endogenous GA levels in Arabidopsis. Black-Right-Pointing-Pointer GA exogenous applied decreases Cd accumulation in plant. Black-Right-Pointing-Pointer GA suppresses the Cd-induced accumulation of NO. Black-Right-Pointing-Pointer Decreased NO level downregulates the expression of IRT1. Black-Right-Pointing-Pointer Suppressed IRT1 expression reduces Cd transport across plasma membrane. - Abstract: Gibberellic acid (GA) is involved in not only plant growth and development but also plant responses to abiotic stresses. Here it was found that treating the plants with GA concentrations from 0.1 to 5 {mu}M for 24 h had no obvious effect on root elongation in the absence of cadmium (Cd), whereas in the presence of Cd{sup 2+}, GA at 5 {mu}M improved root growth, reduced Cd content and lipid peroxidation in the roots, indicating that GA can partially alleviate Cd toxicity. Cd{sup 2+} increased nitric oxide (NO) accumulation in the roots, but GA remarkably reduced it, and suppressed the up-regulation of the expression of IRT1. In contrary, the beneficial effect of GA on alleviating Cd toxicity was not observed in an IRT1 knock-out mutant irt1, suggesting the involvement of IRT1 in Cd{sup 2+} absorption. Furthermore, the GA-induced reduction of NO and Cd content can also be partially reversed by the application of a NO donor (S-nitrosoglutathione [GSNO]). Taken all these together, the results showed that GA-alleviated Cd toxicity is mediated through the reduction of the Cd-dependent NO accumulation and expression of Cd{sup 2+} uptake related gene-IRT1 in Arabidopsis.

  10. Accumulation of sigmaS due to enhanced synthesis and decreased degradation in acidic phospholipid-deficient Escherichia coli cells.

    Uchiyama, Junji; Sasaki, Yu; Nagahama, Hideki; Itou, Aya; Matsuoka, Satoshi; Matsumoto, Kouji; Hara, Hiroshi

    2010-06-01

    The Escherichia coli pgsA3 mutation, which causes deficiency in acidic phospholipids, leads to a significant accumulation of sigma(S). This accumulation is partly accounted for by the higher transcription level of rpoS; however, it has also been suggested that the cells accumulate sigma(S) post-transcriptionally. We found that the level of the small regulatory RNA RprA, which is involved in the promotion of rpoS translation, is higher in pgsA3 cells than in pgsA(+) cells. Induction of altered rpoS mRNA that does not depend on RprA in pgsA(+) cells did not increase the level of sigma(S) to the high level observed in pgsA3 cells, suggesting post-translational sigma(S) accumulation in the latter. The mRNA levels of clpX and clpP, whose products form a ClpXP protease that degrades sigma(S), were much reduced in pgsA3 cells. Consistent with the reduced mRNA levels, the half-life of sigma(S) in pgsA3 cells was much longer than in pgsA(+) cells, indicating that downregulation of the degradation is a major cause for the high sigma(S) content. We show that the downregulation can be partially attributed to activated CpxAR in the mutant cells, which causes repression of rpoE on whose gene product the expression of clpPX depends. PMID:20455949

  11. Loss of cation-independent mannose 6-phosphate receptor expression promotes the accumulation of lysobisphosphatidic acid in multilamellar bodies.

    Reaves, B J; Row, P E; Bright, N A; Luzio, J P; Davidson, H W

    2000-11-01

    A number of recent studies have highlighted the importance of lipid domains within endocytic organelles in the sorting and movement of integral membrane proteins. In particular, considerable attention has become focussed upon the role of the unusual phospholipid lysobisphosphatidic acid (LBPA). This lipid appears to be directly involved in the trafficking of cholesterol and glycosphingolipids, and accumulates in a number of lysosomal storage disorders. Antibody-mediated disruption of LBPA function also leads to mis-sorting of cation-independent mannose 6-phosphate receptors. We now report that the converse is also true, and that spontaneous loss of cation-independent mannose 6-phosphate receptors from a rat fibroblast cell line led to the formation of aberrant late endocytic structures enriched in LBPA. Accumulation of LBPA was directly dependent upon the loss of the receptors, and could be reversed by expression of bovine cation-independent mannose 6-phosphate receptors in the mutant cell line. Ultrastructural analysis indicated that the abnormal organelles were electron-dense, had a multi-lamellar structure, accumulated endocytosed probes, and were distinct from dense-core lysosomes present within the same cells. The late endocytic structures present at steady state within any particular cell likely reflect the balance of membrane traffic through the endocytic pathway of that cell, and the rate of maturation of individual endocytic organelles. Moreover, there is considerable evidence which suggests that cargo receptors also play a direct mechanistic role in membrane trafficking events. Therefore, loss of such a protein may disturb the overall equilibrium of the pathway, and hence cause the accumulation of aberrant organelles. We propose that this mechanism underlies the phenotype of the mutant cell line, and that the formation of inclusion bodies in many lysosomal storage diseases is also due to an imbalance in membrane trafficking within the endocytic pathway

  12. The plant immunity inducer pipecolic acid accumulates in the xylem sap and leaves of soybean seedlings following Fusarium virguliforme infection.

    Abeysekara, Nilwala S; Swaminathan, Sivakumar; Desai, Nalini; Guo, Lining; Bhattacharyya, Madan K

    2016-02-01

    The causal agent of the soybean sudden death syndrome (SDS), Fusarium virguliforme, remains in infected roots and secretes toxins to cause foliar SDS. In this study we investigated the xylem sap, roots, and leaves of F. virguliforme-infected and -uninfected soybean seedlings for any changes in a set of over 3,000 metabolites following pathogen infection by conducting GC/MS and LC/MS/MS, and detected 273 biochemicals. Levels of many intermediates of the TCA cycle were reduced suggesting suppression of this metabolic pathway by the pathogen. There was an increased accumulation of peroxidated lipids in leaves of F. virguliforme-infected plants suggesting possible involvement of free radicals and lipoxygenases in foliar SDS development. Levels of both isoflavone conjugates and isoflavonoid phytoalexins were decreased in infected roots suggesting degradation of these metabolites by the pathogen to promote root necrosis. The levels of the plant immunity inducer pipecolic acid (Pip) and the plant hormone salicylic acid (SA) were significantly increased in xylem sap (in case of Pip) and leaves (in case of both Pip and SA) of F. virguliforme-infected soybean plants compared to the control plants. This suggests a major signaling role of Pip in inducing host defense responses in above ground parts of the F. virguliforme-infected soybean. Increased accumulation of pipecolic acid in foliar tissues was associated with the induction of GmALD1, the soybean homolog of Arabidopsis ALD1. This metabolomics study generated several novel hypotheses for studying the mechanisms of SDS development in soybean. PMID:26795155

  13. Amino acid limitation induces down-regulation of WNT5a at transcriptional level

    An aberrant WNT signaling contributes to the development and progression of multiple cancers. WNT5a is one of the WNT signaling molecules. This study was designed to test the hypothesis that amino acid deprivation induces changes in the WNT signaling pathway in colon cancer cells. Results showed that targets of the amino acid response pathway, ATF3 and p21, were induced in the human colon cancer cell line SW480 during amino acid limitation. There was a significant decrease in the WNT5a mRNA level following amino acid deprivation. The down-regulation of WNT5a mRNA by amino acid deprivation is not due to mRNA destabilization. There is a reduction of nuclear β-catenin protein level by amino acid limitation. Under amino acid limitation, phosphorylation of ERK1/2 was increased and the blockage of ERK1/2 by the inhibitor U0126 partially restored WNT5a mRNA level. In conclusion, amino acid limitation in colon cancer cells induces phosphorylation of ERK1/2, which then down-regulates WNT5a expression.

  14. Simultaneous effect of nitrate (NO3- concentration, carbon dioxide (CO2 supply and nitrogen limitation on biomass, lipids, carbohydrates and proteins accumulation in Nannochloropsis oculata

    Aarón Millán-Oropeza

    2015-03-01

    Full Text Available Biodiesel from microalgae is a promising technology. Nutrient limitation and the addition of CO2 are two strategies to increase lipid content in microalgae. There are two different types of nitrogen limitation, progressive and abrupt limitation. In this work, the simultaneous effect of initial nitrate concentration, addition of CO2, and nitrogen limitation on biomass, lipid, protein and carbohydrates accumulation were analyzed. An experimental design was established in which initial nitrogen concentration, culture time and CO2 aeration as independent numerical variables with three levels were considered. Nitrogen limitation was taken into account as a categorical independent variable. For the experimental design, all the experiments were performed with progressive nitrogen limitation. The dependent response variables were biomass, lipid production, carbohydrates and proteins. Subsequently, comparison of both types of limitation i.e. progressive and abrupt limitation, was performed. Nitrogen limitation in a progressive mode exerted a greater effect on lipid accumulation. Culture time, nitrogen limitation and the interaction of initial nitrate concentration with nitrogen limitation had higher influences on lipids and biomass production. The highest lipid production and productivity were at 582 mgL-1 (49.7 % lipid, dry weight basis and 41.5 mgL-1d-1, respectively; under the following conditions: 250 mgL-1 of initial nitrate concentration, CO2 supply of 4% (v/v, 12 d of culturing and 2 d in state of nitrogen starvation induced by progressive limitation. This work presents a novel way to perform simultaneous analysis of the effect of the initial concentration of nitrate, nitrogen limitation, and CO2 supply on growth and lipid production of Nannochloropsis oculata, with the aim to produce potential biofuels feedstock.

  15. SFH2 regulates fatty acid synthase activity in the yeast Saccharomyces cerevisiae and is critical to prevent saturated fatty acid accumulation in response to haem and oleic acid depletion.

    Desfougères, Thomas; Ferreira, Thierry; Bergès, Thierry; Régnacq, Matthieu

    2008-01-01

    The yeast Saccharomyces cerevisiae is a facultative anaerobic organism. Under anaerobiosis, sustained growth relies on the presence of exogenously supplied unsaturated fatty acids and ergosterol that yeast is unable to synthesize in the absence of oxygen or upon haem depletion. In the absence of exogenous supplementation with unsaturated fatty acid, a net accumulation of SFA (saturated fatty acid) is observed that induces significant modification of phospholipid profile [Ferreira, Régnacq, Alimardani, Moreau-Vauzelle and Bergès (2004) Biochem. J. 378, 899-908]. In the present paper, we focus on the role of SFH2/CSR1, a hypoxic gene related to SEC14 and its involvement in lipid metabolism upon haem depletion in the absence of oleic acid supplementation. We observed that inactivation of SFH2 results in enhanced accumulation of SFA and phospholipid metabolism alterations. It results in premature growth arrest and leads to an exacerbated sensitivity to exogenous SFA. This phenotype is suppressed in the presence of exogenous oleic acid, or by a controlled expression of FAS1, one of the two genes encoding FAS. We present several lines of evidence to suggest that Sfh2p and oleic acid regulate SFA synthase in yeast at different levels: whereas oleic acid acts on FAS2 at the transcriptional level, we show that Sfh2p inhibits fatty acid synthase activity in response to haem depletion. PMID:17803462

  16. 1-FFT amino acids involved in high DP inulin accumulation in Viguiera discolor

    Emerik eDe Sadeleer

    2015-08-01

    Full Text Available Fructans are important vacuolar reserve carbohydrates with drought, cold, ROS and general abiotic stress mediating properties. They occur in 15% of all flowering plants and are believed to display health benefits as a prebiotic and dietary fiber. Fructans are synthesized by specific fruc- tosyltransferases and classified based on the linkage type between fructosyl units. Inulins, one of these fructan types with β(2-1 linkages, are elongated by fructan:fructan 1-fructosyltransferases (1-FFT using a fructosyl unit from a donor inulin to elongate the acceptor inulin molecule. The sequence identity of the 1-FFT of Viguiera discolor (Vd and Helianthus tuberosus (Ht is 91% although these enzymes produce distinct fructans. The Vd 1-FFT produces high degree of poly- merization (DP inulins by preferring the elongation of long chain inulins, in contrast to the Ht 1-FFT which prefers small molecules (DP3 or 4 as acceptor. Since higher DP inulins have in- teresting properties for industrial, food and medical applications, we report here on the influence of two amino acids on the high DP inulin production capacity of the Vd 1-FFT. Introducing the M19F and H308T mutations in the active site of the Vd 1-FFT greatly reduces its capacity to pro- duce high DP inulin molecules. Both amino acids can be considered important to this capacity, although the double mutation had a much higher impact than the single mutations.

  17. Trichoderma inoculation augments grain amino acids and mineral nutrients by modulating arsenic speciation and accumulation in chickpea (Cicer arietinum L.).

    Tripathi, Pratibha; Singh, Poonam C; Mishra, Aradhana; Tripathi, Rudra D; Nautiyal, Chandra S

    2015-07-01

    Trichoderma reesei is an industrially important fungi which also imparts stress tolerance and plant growth promotion in various crops. Arsenic (As) contamination of field soils is one of the challenging problems in agriculture, posing potential threats for both human health and the environment. Plants in association with microbes are a liable method to improve metal tolerance and enhance crop productivity. Chickpea (Cicer arietinum L.), is an important grain legume providing cheap source of protein in semi-arid regions including As affected areas. In this study we report the role of T. reesei NBRI 0716 (NBRI 0716) in supporting chickpea growth and improving soil quality in As simulated conditions. NBRI 0716 modulated the As speciation and its availability to improve grain yield and quality (amino acids and mineral content) in chickpea (C. arietinum L.) plants grown in As spiked soil (100 mg As kg(-1) soil). Arsenic accumulation and speciation results indicate that arsenate [As(V)] was the dominant species in chickpea seeds and rhizosphere soil. The Trichoderma reduced total grain inorganic As (Asi) by 66% and enhanced dimethylarsonic acid (DMA) and monomethylarsinic acid (MMA) content of seed and rhizosphere soil. The results indicate a probable role of NBRI 0716 in As methylation as the possible mechanism for maneuvering As stress in chickpea. Analysis of functional diversity using carbon source utilization (Biolog) showed significant difference in diversity and evenness indices among the soil microbial rhizosphere communities. Microbial diversity loss caused by As were prevented in the presence of Trichoderma NBRI 0716. PMID:25839184

  18. Analysis of Organic Acids Accumulated in Kochia Scoparia Shoots and Roots by Reverse-phase High Performance Liquid Chromatography Under Salt and Alkali Stress

    2006-01-01

    Several organic acids accumulated in Kochia Scoparia shoots and roots were studied by means of reverse-phase high performance liquid chromatography with a C18 column. Five types of binary organic acids were separated. The organic acid concentrations were determined in K. Scoparia seedlings stressed by saline (NaCl) and alkaline(NaHCO3) at the same Na + concentration. Concentrations of organic acids are stimulated by alkaline because the cells will adjust their pH values through the accumulation of organic acids, when the environment is basic. The concentrations of oxalic acid and succinic acid are higher than those of other organic acids, including tartaric acid and malic acid, and the concentration of citric acid is the lowest. The concentrations of the organic acids in the roots are higher than those in the shoots under salt(NaCl) stress, but the results are opposite while the roots are under alkali (NaHCO3) stress. This indicates that there are different adaptive strategies for K. Scoparia seedlings in organic acid metabolism under salt and alkali stress.

  19. Accumulation of Phenolic Compounds and Expression Profiles of Phenolic Acid Biosynthesis-Related Genes in Developing Grains of White, Purple, and Red Wheat.

    Ma, Dongyun; Li, Yaoguang; Zhang, Jian; Wang, Chenyang; Qin, Haixia; Ding, Huina; Xie, Yingxin; Guo, Tiancai

    2016-01-01

    Polyphenols in whole grain wheat have potential health benefits, but little is known about the expression patterns of phenolic acid biosynthesis genes and the accumulation of phenolic acid compounds in different-colored wheat grains. We found that purple wheat varieties had the highest total phenolic content (TPC) and antioxidant activity. Among phenolic acid compounds, bound ferulic acid, vanillic, and caffeic acid levels were significantly higher in purple wheat than in white and red wheat, while total soluble phenolic acid, soluble ferulic acid, and vanillic acid levels were significantly higher in purple and red wheat than in white wheat. Ferulic acid and syringic acid levels peaked at 14 days after anthesis (DAA), whereas p-coumaric acid and caffeic acid levels peaked at 7 DAA, and vanillic acid levels gradually increased during grain filling and peaked near ripeness (35 DAA). Nine phenolic acid biosynthesis pathway genes (TaPAL1, TaPAL2, TaC3H1, TaC3H2, TaC4H, Ta4CL1, Ta4CL2, TaCOMT1, and TaCOMT2) exhibited three distinct expression patterns during grain filling, which may be related to the different phenolic acids levels. White wheat had higher phenolic acid contents and relatively high gene expression at the early stage, while purple wheat had the highest phenolic acid contents and gene expression levels at later stages. These results suggest that the expression of phenolic acid biosynthesis genes may be closely related to phenolic acids accumulation. PMID:27148345

  20. Accumulation of Phenolic Compounds and Expression Profiles of Phenolic Acid Biosynthesis-Related Genes in Developing Grains of White, Purple, and Red Wheat

    Ma, Dongyun; Li, Yaoguang; Zhang, Jian; Wang, Chenyang; Qin, Haixia; Ding, Huina; Xie, Yingxin; Guo, Tiancai

    2016-01-01

    Polyphenols in whole grain wheat have potential health benefits, but little is known about the expression patterns of phenolic acid biosynthesis genes and the accumulation of phenolic acid compounds in different-colored wheat grains. We found that purple wheat varieties had the highest total phenolic content (TPC) and antioxidant activity. Among phenolic acid compounds, bound ferulic acid, vanillic, and caffeic acid levels were significantly higher in purple wheat than in white and red wheat, while total soluble phenolic acid, soluble ferulic acid, and vanillic acid levels were significantly higher in purple and red wheat than in white wheat. Ferulic acid and syringic acid levels peaked at 14 days after anthesis (DAA), whereas p-coumaric acid and caffeic acid levels peaked at 7 DAA, and vanillic acid levels gradually increased during grain filling and peaked near ripeness (35 DAA). Nine phenolic acid biosynthesis pathway genes (TaPAL1, TaPAL2, TaC3H1, TaC3H2, TaC4H, Ta4CL1, Ta4CL2, TaCOMT1, and TaCOMT2) exhibited three distinct expression patterns during grain filling, which may be related to the different phenolic acids levels. White wheat had higher phenolic acid contents and relatively high gene expression at the early stage, while purple wheat had the highest phenolic acid contents and gene expression levels at later stages. These results suggest that the expression of phenolic acid biosynthesis genes may be closely related to phenolic acids accumulation. PMID:27148345

  1. Inhibition of norsolorinic acid accumulation to Aspergillus parasiticus by marine actinomycetes

    Yan, Peisheng; Shi, Cuijuan; Shen, Jihong; Wang, Kai; Gao, Xiujun; Li, Ping

    2014-11-01

    Thirty-six strains of marine actinomycetes were isolated from a sample of marine sediment collected from the Yellow Sea and evaluated in terms of their inhibitory activity on the growth of Aspergillus parasiticus and the production of norsolorinic acid using dual culture plate assay and agar diffusion methods. Among them, three strains showed strong antifungal activity and were subsequently identified as Streptomyces sp. by 16S rRNA gene sequencing analysis. The supernatant from the fermentation of the MA01 strain was extracted sequentially with chloroform and ethyl acetate, and the activities of the extracts were determined by tip culture assay. The assay results show that both extracts inhibited mycelium growth and toxin production, and the inhibitory activities of the extracts increased as their concentrations increased. The results of this study suggest that marine actinomycetes are biologically important for the control of mycotoxins, and that these bacteria could be used as novel biopesticides against mycotoxins.

  2. Effects of salicylic acid on thermotolerance and cardenolide accumulation under high temperature stress in Digitalis trojana Ivanina.

    Cingoz, Gunce Sahin; Gurel, Ekrem

    2016-08-01

    Long periods of high temperature or transitory increased temperature, a widespread agricultural problem, may lead to a drastic reduction in economic yield, affecting plant growth and development in many areas of the world. Heat stress causes many anatomical and physiological changes in plants. Its unfavorable effects can be alleviated by thermotolerance induced by exogenous application of plant growth regulators and osmoprotectants or by gradual application of temperature stress. Digitalis trojana Ivanina is an important medicinal plant species well known mainly for its cardenolides. The production of cardenolides via traditional agriculture is commercially inadequate. In this study, elicitation strategies were employed for improving crop thermotolerance and accumulation of cardenolides. For these purposes, the effects of salicylic acid (SA) and/or high temperature treatments in inducing cardenolide accumulation and thermotolerance were tested in callus cultures of D. trojana. Considerable increases in the production of cardenolides (up to 472.28 μg.g(-1) dry weight, dw) and induction of thermotolerance capacity were observed when callus cultures were exposed to high temperature for 2 h after pretreating with SA. High temperature treatments (2 h and 4 h) caused a marked reduction in superoxide dismutase (SOD; EC 1.15.1.1) and catalase (CAT; EC 1.11.1.6) activities, while SA pretreatment increased their activities. High temperature and/or SA appeared to increase the levels of proline, total phenolic, and flavonoid content. Elevated phenolic accumulation could be associated with increased stress protection. These results indicated that SA treatments induced synthesis of antioxidants and cardenolides, which may play a significant role in resistance to high temperature stress. PMID:27105421

  3. Involvement of indole-3-acetic acid produced by Azospirillum brasilense in accumulating intracellular ammonium in Chlorella vulgaris.

    Meza, Beatriz; de-Bashan, Luz E; Bashan, Yoav

    2015-01-01

    Accumulation of intracellular ammonium and activities of the enzymes glutamine synthetase (GS) and glutamate dehydrogenase (GDH) were measured when the microalgae Chlorella vulgaris was immobilized in alginate with either of two wild type strains of Azospirillum brasilense or their corresponding indole-3-acetic acid (IAA)-attenuated mutants. After 48 h of immobilization, both wild types induced higher levels of intracellular ammonium in the microalgae than their respective mutants; the more IAA produced, the higher the intracellular ammonium accumulated. Accumulation of intracellular ammonium in the cells of C. vulgaris followed application of four levels of exogenous IAA reported for A. brasilense and its IAA-attenuated mutants, which had a similar pattern for the first 24 h. This effect was transient and disappeared after 48 h of incubation. Immobilization of C. vulgaris with any bacteria strain induced higher GS activity. The bacterial strains also had GS activity, comparable to the activity detected in C. vulgaris, but weaker than when immobilized with the bacteria. When net activity was calculated, the wild type always induced higher GS activity than IAA-attenuated mutants. GDH activity in most microalgae/bacteria interactions resembled GS activity. When complementing IAA-attenuated mutants with exogenous IAA, GS activity in co-immobilized cultures matched those of the wild type A. brasilense immobilized with the microalga. Similarity occurred when the net GS activity was measured, and was higher with greater quantities of exogenous IAA. It is proposed that IAA produced by A. brasilense is involved in ammonium uptake and later assimilation by C. vulgaris. PMID:25554489

  4. Resistance of Streptococcus bovis to acetic acid at low pH: Relationship between intracellular pH and anion accumulation

    Streptococcus bovis JB1, an acid-tolerant ruminal bacterium, was able to grown at pHs from 6.7 to 4.5, and 100 mM acetate had little effect on growth rate or proton motive force across the cell membrane. When S. bovis was grown in glucose-limited chemostats at pH 5.2, the addition of sodium acetate (as much as 100 mM) had little effect on the production of bacterial protein. At higher concentrations of sodium acetate (100 to 360 mM), production of bacterial protein declined, but this decrease could largely be explained by a shift in fermentation products (acetate, formate, and ethanol production to lactate production) and a decline in ATP production (3 ATP per glucose versus 2 ATP per glucose). YATP (grams of cells per mole at ATP) was not decreased significantly even by high concentrations of acetate. Cultures supplemented with 100 mM sodium acetate took up [14C]acetate and [14C]benzoate in accordance with the Henderson-Hasselbalch equation and gave similar estimates of intracellular pH. As the extracellular pH declined, S. bovis allowed its intracellular pH to decrease and maintained a relatively constant pH gradient across the cell membrane (0.9 unit). The decrease in intracellular pH prevented S. bovis from accumulating large amounts of acetate anion. On the basis of these results it did not appear that acetate was acting as an uncoupler. The sensitivity of other bacteria to volatile fatty acids at low pH is explained most easily by a high transmembrane pH gradient and anion accumulation

  5. Ascorbic acid enhances the accumulation of polycyclic aromatic hydrocarbons (PAHs in roots of tall fescue (Festuca arundinacea Schreb..

    Yanzheng Gao

    Full Text Available Plant contamination by polycyclic aromatic hydrocarbons (PAHs is crucial to food safety and human health. Enzyme inhibitors are commonly utilized in agriculture to control plant metabolism of organic components. This study revealed that the enzyme inhibitor ascorbic acid (AA significantly reduced the activities of peroxidase (POD and polyphenol oxidase (PPO, thus enhancing the potential risks of PAH contamination in tall fescue (Festuca arundinacea Schreb.. POD and PPO enzymes in vitro effectively decomposed naphthalene (NAP, phenanthrene (PHE and anthracene (ANT. The presence of AA reduced POD and PPO activities in plants, and thus was likely responsible for enhanced PAH accumulation in tall fescue. This conclusion is supported by the significantly enhanced uptake of PHE in plants in the presence of AA, and the positive correlation between enzyme inhibition efficiencies and the rates of metabolism of PHE in tall fescue roots. This study provides a new perspective, that the common application of enzyme inhibitors in agricultural production could increase the accumulation of organic contaminants in plants, hence enhancing risks to food safety and quality.

  6. Sulfur alleviates arsenic toxicity by reducing its accumulation and modulating proteome, amino acids and thiol metabolism in rice leaves

    Dixit, Garima; Singh, Amit Pal; Kumar, Amit; Dwivedi, Sanjay; Deeba, Farah; Kumar, Smita; Suman, Shankar; Adhikari, Bijan; Shukla, Yogeshwar; Trivedi, Prabodh Kumar; Pandey, Vivek; Tripathi, Rudra Deo

    2015-11-01

    Arsenic (As) contamination of water is a global concern and rice consumption is the biggest dietary exposure to human posing carcinogenic risks, predominantly in Asia. Sulfur (S) is involved in di-sulfide linkage in many proteins and plays crucial role in As detoxification. Present study explores role of variable S supply on rice leaf proteome, its inclination towards amino acids (AA) profile and non protein thiols under arsenite exposure. Analysis of 282 detected proteins on 2-DE gel revealed 113 differentially expressed proteins, out of which 80 were identified by MALDI-TOF-TOF. The identified proteins were mostly involved in glycolysis, TCA cycle, AA biosynthesis, photosynthesis, protein metabolism, stress and energy metabolism. Among these, glycolytic enzymes play a major role in AA biosynthesis that leads to change in AAs profiling. Proteins of glycolytic pathway, photosynthesis and energy metabolism were also validated by western blot analysis. Conclusively S supplementation reduced the As accumulation in shoot positively skewed thiol metabolism and glycolysis towards AA accumulation under AsIII stress.

  7. Foliar abscisic acid-to-ethylene accumulation and response regulate shoot growth sensitivity to mild drought in wheat

    Ravi eValluru

    2016-04-01

    Full Text Available Although plant hormones play an important role in adjusting growth in response to environmental perturbation, the relative contributions of abscisic acid (ABA and ethylene remain elusive. Using six spring wheat genotypes differing for stress tolerance, we show that young seedlings of the drought-tolerant (DT group maintained or increased shoot dry weight (SDW while the drought-susceptible (DS group decreased SDW in response to mild drought. Both the DT and DS groups increased endogenous ABA and ethylene concentrations under mild drought compared to control. The DT and DS groups exhibited different SDW response trends, whereby the DS group decreased while the DT group increased SDW, to increased concentrations of ABA and ethylene under mild drought, although both groups decreased ABA/ethylene ratio under mild drought albeit at different levels. We concluded that SDW of the DT and DS groups might be distinctly regulated by specific ABA:ethylene ratio. Further, a foliar-spray of low concentrations (0.1 μM of ABA increased shoot relative growth rate (RGR in the DS group while ACC (1-aminocyclopropane-1-carboxylic acid, ethylene precursor spray increased RGR in both groups compared to control. Furthermore, the DT group accumulated a significantly higher galactose while a significantly lower maltose in the shoot compared to the DS group. Taken all together, these results suggest an impact of ABA, ethylene and ABA:ethylene ratio on SDW of wheat seedlings that may partly underlie a genotypic variability of different shoot growth sensitivities to drought among crop species under field conditions. We propose that phenotyping based on hormone accumulation, response and hormonal ratio would be a viable, rapid, and an early–stage selection tool aiding genotype selection for stress tolerance.

  8. Foliar Abscisic Acid-To-Ethylene Accumulation and Response Regulate Shoot Growth Sensitivity to Mild Drought in Wheat.

    Valluru, Ravi; Davies, William J; Reynolds, Matthew P; Dodd, Ian C

    2016-01-01

    Although, plant hormones play an important role in adjusting growth in response to environmental perturbation, the relative contributions of abscisic acid (ABA) and ethylene remain elusive. Using six spring wheat genotypes differing for stress tolerance, we show that young seedlings of the drought-tolerant (DT) group maintained or increased shoot dry weight (SDW) while the drought-susceptible (DS) group decreased SDW in response to mild drought. Both the DT and DS groups increased endogenous ABA and ethylene concentrations under mild drought compared to control. The DT and DS groups exhibited different SDW response trends, whereby the DS group decreased while the DT group increased SDW, to increased concentrations of ABA and ethylene under mild drought, although both groups decreased ABA/ethylene ratio under mild drought albeit at different levels. We concluded that SDW of the DT and DS groups might be distinctly regulated by specific ABA:ethylene ratio. Further, a foliar-spray of low concentrations (0.1 μM) of ABA increased shoot relative growth rate (RGR) in the DS group while ACC (1-aminocyclopropane-1-carboxylic acid, ethylene precursor) spray increased RGR in both groups compared to control. Furthermore, the DT group accumulated a significantly higher galactose while a significantly lower maltose in the shoot compared to the DS group. Taken all together, these results suggest an impact of ABA, ethylene, and ABA:ethylene ratio on SDW of wheat seedlings that may partly underlie a genotypic variability of different shoot growth sensitivities to drought among crop species under field conditions. We propose that phenotyping based on hormone accumulation, response and hormonal ratio would be a viable, rapid, and an early-stage selection tool aiding genotype selection for stress tolerance. PMID:27148292

  9. On the state of jumus accumulation observed in soil profile and the contents of sugar, uronic acid and amino acid in fulvic acid fraction

    In a previous report, the author wrote on the form of volcanic soil in Onohara, Tarumi City, which consists of about fourty soil layers, and seventeen of which contain more than 0.69% total carbon. The present report is concerned with the result of determination of 1) carbon and nitrogen contents of the soil and its fulvic acid, humic acid and humine, 2) sugar, uronic acid and amino acid contents and amino acid composition of fulvic acid fraction, and 3) 14C age of some soil layers. Methods of sample preparation and content determination are briefly given, and the results are shown. 14C age ranged from some 5500 to 9300 yr. B. P. In general tendency, as the carbon content of a soil layer is higher, its C/N ratio is higher, and C/N ratio of fulvic acid Fraction is almost constant (10-13) in all samples. The total content of sugar, uronic acid and hydrolytic amino acid is 30-40% of that of fulvic acid and almost invariable for all layers, 19-25% of which being occupied by the first two. (Shibata, I.)

  10. Reduced Inflammation in the Tumor Microenvironment Delays the Accumulation of Myeloid-Derived Suppressor Cells and Limits Tumor Progression

    Bunt, Stephanie K.; YANG, LINGLIN; Sinha, Pratima; Clements, Virginia K.; Leips, Jeff; Ostrand-Rosenberg, Suzanne

    2007-01-01

    Chronic inflammation is frequently associated with malignant growth and is thought to promote and enhance tumor progression, although the mechanisms which regulate this relationship remain elusive. We reported previously that interleukin (IL)-1β promoted tumor progression by enhancing the accumulation of myeloid-derived suppressor cells (MDSC), and hypothesized that inflammation leads to cancer through the production of MDSC which inhibit tumor immunity. If inflammation-induced MDSC promote t...

  11. Prevention of volatile fatty acids production and limitation of odours from winery wastewaters by denitrification.

    Bories, André; Guillot, Jean-Michel; Sire, Yannick; Couderc, Marie; Lemaire, Sophie-Andréa; Kreim, Virginie; Roux, Jean-Claude

    2007-07-01

    The effect of the addition of nitrate to winery wastewaters to control the formation of VFA in order to prevent odours during storage and treatment was studied in batch bioreactors at different NO(3)/chemical oxygen demand (COD) ratios and at full scale in natural evaporation ponds (2 x 7000 m(2)) by measuring olfactory intensity. In the absence of nitrate, butyric acid (2304 mgL(-1)), acetic acid (1633 mgL(-1)), propionic acid (1558 mgL(-1)), caproic acid (499 mgL(-1)) and valeric acid (298 mgL(-1)) were produced from reconstituted winery wastewater. For a ratio of NO(3)/COD=0.4 gg(-1), caproic and valeric acids were not formed. The production of butyric and propionic acids was reduced by 93.3% and 72.5%, respectively, at a ratio of NO(3)/COD=0.8, and by 97.4% and 100% at a ratio of NO(3)/COD=1.2 gg(-1). Nitrate delayed and decreased butyric acid formation in relation to the oxidoreduction potential. Studies in ponds showed that the addition of concentrated calcium nitrate (NITCAL) to winery wastewaters (3526 m(3)) in a ratio of NO(3)/COD=0.8 inhibited VFA production, with COD elimination (94%) and total nitrate degradation, and no final nitrite accumulation. On the contrary, in ponds not treated with nitrate, malodorous VFA (from propionic to heptanoïc acids) represented up to 60% of the COD. Olfactory intensity measurements in relation to the butanol scale of VFA solutions and the ponds revealed the pervasive role of VFA in the odour of the untreated pond as well as the clear decrease in the intensity and not unpleasant odour of the winery wastewater pond enriched in nitrates. The results obtained at full scale underscored the feasibility and safety of the calcium nitrate treatment as opposed to concentrated nitric acid. PMID:17467770

  12. NFX1-LIKE2 (NFXL2 suppresses abscisic acid accumulation and stomatal closure in Arabidopsis thaliana.

    Janina Lisso

    Full Text Available The NFX1-LIKE1 (NFXL1 and NFXL2 genes were identified as regulators of salt stress responses. The NFXL1 protein is a nuclear factor that positively affects adaptation to salt stress. The nfxl1-1 loss-of-function mutant displayed reduced survival rates under salt and high light stress. In contrast, the nfxl2-1 mutant, defective in the NFXL2 gene, and NFXL2-antisense plants exhibited enhanced survival under these conditions. We show here that the loss of NFXL2 function results in abscisic acid (ABA overaccumulation, reduced stomatal conductance, and enhanced survival under drought stress. The nfxl2-1 mutant displayed reduced stomatal aperture under all conditions tested. Fusicoccin treatment, exposition to increasing light intensities, and supply of decreasing CO(2 concentrations demonstrated full opening capacity of nfxl2-1 stomata. Reduced stomatal opening presumably is a consequence of elevated ABA levels. Furthermore, seedling growth, root growth, and stomatal closure were hypersensitive to exogenous ABA. The enhanced ABA responses may contribute to the improved drought stress resistance of the mutant. Three NFXL2 splice variants were cloned and named NFXL2-78, NFXL2-97, and NFXL2-100 according to the molecular weight of the putative proteins. Translational fusions to the green fluorescent protein suggest nuclear localisation of the NFXL2 proteins. Stable expression of the NFXL2-78 splice variant in nfxl2-1 plants largely complemented the mutant phenotype. Our data show that NFXL2 controls ABA levels and suppresses ABA responses. NFXL2 may prevent unnecessary and costly stress adaptation under favourable conditions.

  13. Implication of organic acids in the long-distance transport and the accumulation of lead in Sesuvium portulacastrum and Brassica juncea.

    Ghnaya, Tahar; Zaier, Hanen; Baioui, Raoudha; Sghaier, Souhir; Lucchini, Giorgio; Sacchi, Gian Attilio; Lutts, Stanley; Abdelly, Chedly

    2013-01-01

    The implication of organic acids in Pb translocation was studied in two species varying in shoot lead accumulation, Sesuvium portulacastrum and Brassica juncea. Citric, fumaric, malic and α-cetoglutaric acids were separated and determined by HPLC technique in shoots, roots and xylem saps of the both species grown in nutrient solutions added with 200 and 400 μM of Pb(II). The lead content of the xylem saps was determined by ICP-MS. Results showed that S. portulacastrum is more tolerant to Pb than B. juncea. Lead concentration in xylem sap of the S. portulacastrum was significantly greater than in that of B. juncea. For both species, a positive correlation was established between lead and citrate concentrations in xylem sap. However minor relationship was observed for fumaric, malic and α-cetoglutaric acids. In the shoots lead treatment also induced a significant increase in citric acid concentration. Both observations suggest the implication of citric acid in lead translocation and shoot accumulation in S. portulacastrum and B. juncea. The relatively high accumulation of citric acid in xylem sap and shoot of S. portulacastrum could explain its high potential to translocate and accumulate this metal in shoot suggesting their possible use to remediate Pb polluted soils. PMID:23026160

  14. Enhanced production of nitric oxide, reactive oxygen species, and pro-inflammatory cytokines in very long chain saturated fatty acid-accumulated macrophages

    Kiyanagi Takashi; Sumiyoshi Katsuhiko; Kitamura Yohei; Kume Atsumi; Miyazaki Tetsuro; Shimada Kazunori; Yanagisawa Naotake; Iesaki Takafumi; Inoue Nao; Daida Hiroyuki

    2008-01-01

    Abstract Background Deterioration of peroxisomal β-oxidation activity causes an accumulation of very long chain saturated fatty acids (VLCSFA) in various organs. We have recently reported that the levels of VLCSFA in the plasma and/or membranes of blood cells were significantly higher in patients with metabolic syndrome and in patients with coronary artery disease than the controls. The aim of the present study is to investigate the effect of VLCSFA accumulation on inflammatory and oxidative ...

  15. Cadmium and manganese accumulation in Phytolacca americana L. and the roles of non-protein thiols and organic acids.

    Gao, Lu; Peng, Kejian; Xia, Yan; Wang, Guiping; Niu, Liyuan; Lian, Chunlan; Shen, Zhenguo

    2013-01-01

    Phytolacca americana L. can accumulate large amounts of heavy metals in its aerial tissues, especially cadmium (Cd) and manganese (Mn). It has great potential for use in phytoextraction of metals from multi-metal-contaminated soils. This study was conducted to further investigate the Cd- and Mn-tolerance strategies of this plant. Concentrations of non-protein thiols (NPTs) and phytochelatins (PCs) in leaves and roots increased significantly as the concentration of Cd in solution increased. The molar ratios of PCs:soluble Cd ranged from 1.8 to 3.6 in roots and 8.1 to 31.6 in leaves, suggesting that the cellular response involving PC synthesis was sufficient to complex Cd ions in the cytosol, especially that of leaves. In contrast, excess Mn treatments did not result in a significant increase in NPT or PC concentrations in leaves or roots. Oxalic acid concentrations in leaves of plants exposed to 2 or 20 mM Mn reached 69.4 to 89.3 mg (0.771 to 0.992 mmol) g(-1) dry weight, respectively, which was approximately 3.7- to 8.6-fold higher than the Mn level in the 0.6 M HCl extract. Thus, oxalic acid may play an important role in the detoxification of Mn. PMID:23487997

  16. Transport and metabolism of fumaric acid in Saccharomyces cerevisiae in aerobic glucose-limited chemostat culture.

    Shah, Mihir V; van Mastrigt, Oscar; Heijnen, Joseph J; van Gulik, Walter M

    2016-04-01

    Currently, research is being focused on the industrial-scale production of fumaric acid and other relevant organic acids from renewable feedstocks via fermentation, preferably at low pH for better product recovery. However, at low pH a large fraction of the extracellular acid is present in the undissociated form, which is lipophilic and can diffuse into the cell. There have been no studies done on the impact of high extracellular concentrations of fumaric acid under aerobic conditions in S. cerevisiae, which is a relevant issue to study for industrial-scale production. In this work we studied the uptake and metabolism of fumaric acid in S. cerevisiae in glucose-limited chemostat cultures at a cultivation pH of 3.0 (pH exporting fumaric acid. We observed that fumaric acid entered the cells most likely via passive diffusion of the undissociated form. Approximately two-thirds of the fumaric acid in the feed was metabolized together with glucose. From metabolic flux analysis, an increased ATP dissipation was observed only at high intracellular concentrations of fumarate, possibly due to the export of fumarate via an ABC transporter. The implications of our results for the industrial-scale production of fumaric acid are discussed. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26683700

  17. Active accumulation of internal DIC pools reduces transport limitation in large colonies of Nostoc pruniforme

    Raun, Ane-Marie Løvendahl; Borum, Jens; Jensen, Kaj Sand

    2009-01-01

    Nostoc pruniforme is a freshwater cyanobacterium forming large spherical colonies of up to several centimeters in diameter. The size and shape result in low surface area to volume (SA/V) ratios that potentially put severe constraints on resource acquisition. In the present study we have...... polysaccharides contains declining densities of trichomes with increasing colony size. N. pruniforme is a very efficient bicarbonate (HCO3-) user and, in addition, actively accumulates large pools of DIC that can support net photosynthesis for >22 h without a supply of external DIC. Both the efficient HCO3......- utilization and the large internal DIC pools greatly reduce N. pruniforme dependence on the immediate availability and species of external DIC. The location of the trichomes in the shell, the HCO3- utilization and the internal DIC pools mean that colony size only has a minor effect on photosynthetic rates as...

  18. Yeast Extract and Silver Nitrate Induce the Expression of Phenylpropanoid Biosynthetic Genes and Induce the Accumulation of Rosmarinic Acid in Agastache rugosa Cell Culture

    Woo Tae Park; Mariadhas Valan Arasu; Naif Abdullah Al-Dhabi; Sun Kyung Yeo; Jin Jeon; Jong Seok Park; Sook Young Lee; Sang Un Park

    2016-01-01

    The present study aimed to investigate the role of yeast extract and silver nitrate on the enhancement of phenylpropanoid pathway genes and accumulation of rosmarinic acid in Agastache rugosa cell cultures. The treatment of cell cultures with yeast extract (500 mg/L) and silver nitrate (30 mg/L) for varying times enhanced the expression of genes in the phenylpropanoid pathway and the production of rosmarinic acid. The results indicated that the expression of RAS and HPPR was proportional to t...

  19. Influence of different fertilization on the dissolved organic carbon, nitrogen and phosphorus accumulation in acid and limed soils

    Ieva Jokubauskaite

    2015-04-01

    Full Text Available Soil quality has become an important issue in soil science. Dissolved organic carbon (DOC is believed to play an important role in soil processes and in the C, N and P balances, their supplies to plants in all types of soils. It is much more sensitive to soil management than is soil organic matter as a whole, and can be used as a key indicator of soil natural functions. This study aimed to assess the influence of different organic fertilizers on DOC and N, P accumulation. The study was carried out on a moraine loam soil at the Vezaiciai Branch of Lithuanian Research Centre for Agriculture and Forestry in 2012. Farmyard manure (FYM (60 t ha -1 and alternative organic fertilizers (wheat straw, rape residues, roots, stubble, perennial grasses were applied on two soil backgrounds - acid and limed. DOC was analysed using an ion chromatograph SKALAR. Application of organic amendments resulted in a significant increase of soil organic carbon (SOC content, which demonstrates a positive role of organic fertilizers in SOC conservation. The combination of different organic fertilizers and liming had a significant positive effect on DOC concentration in the soil. The highest DOC content (0.241 g kg-1 was established in the limed soil fertilized with farmyard manure. The most unfavourable status of DOC was determined in the unlimed, unfertilized soil. The limed and FYM-applied soil had the highest nitrogen (1.47 g kg-1 and phosphorus (0.84 g kg-1 content compared to the other treatments. Organic fertilizers gave a significant positive effect on SOC and DOC content increase in the topsoil. This immediate increase is generally attributed to the presence of soluble materials in the amendments. Application of organic fertilizers in acid and limed soil increased the nutrient stocks and ensured soil chemical indicators at the optimal level for plant growth and thus may provide a mechanism as well as prediction opportunities for soil fertility, conservation

  20. β-Aminobutyric acid increases abscisic acid accumulation and desiccation tolerance and decreases water use but fails to improve grain yield in two spring wheat cultivars under soil drying

    Du, Yan-Lei; Wang, Zhen-Yu; Fan, Jing-Wei; Turner, Neil C.; Wang, Tao; Li, Feng-Min

    2012-01-01

    A pot experiment was conducted to investigate the effect of the non-protein amino acid, β-aminobutyric acid (BABA), on the homeostasis between reactive oxygen species (ROS) and antioxidant defence during progressive soil drying, and its relationship with the accumulation of abscisic acid (ABA), water use, grain yield, and desiccation tolerance in two spring wheat (Triticum aestivum L.) cultivars released in different decades and with different yields under drought. Drenching the soil with 100...

  1. Control of α-amylase mRNA accumulation by gibberellic acid and calcium in barley aleurone layers

    Pulse-labeling of barley (Hordeum vulgare L. cv Himalaya) aleurone layers incubated for 13 hours in 2.5 micromolar gibberellic acid (GA3) with or without 5 millimolar CaCl2 shows that α-amylase isozymes 3 and 4 are not synthesized in vivo in the absence of Ca2+. No difference was observed in α-amylase mRNA levels between layers incubated for 12 hours in 2.5 micromolar GA3 with 5 millimolar CaCl2 and layers incubated in GA3 alone. RNA isolated from layers incubated for 12 hours in GA3 with and without CA2+. A cDNA clone for α-amylase was isolated and used to measure α-amylase mRNA levels in aleurone layers incubated in the presence and absence of Ca2+ was translated in vitro and was found to produce the same complement of translation products regardless of the presence of Ca2+ in the incubation medium. Immunoprecipitation of translation products showed that the RNA for α-amylase synthesized in Ca2+-deprived aleurone layers was translatable. Ca2+ is required for the synthesis of α-amylase isozymes 3 and 4 at a step after mRNA accumulation and processing

  2. Toxic effects of oil sand naphthenic acids on the biomass accumulation of 21 potential phytoplankton remediation candidates.

    Woodworth, Adam P J; Frank, Richard A; McConkey, Brendan J; Müller, Kirsten M

    2012-12-01

    The oil sands of northern Alberta, Canada contain an estimated 170 billion barrels of crude oil. Extraction processes produce large amounts of liquid tailings known as oil sand process affected water (OSPW) that are toxic to aquatic organisms. Naphthenic acids (NAs), and their sodium salts, represent a significant contributor to the toxicity of these waters. Due to the recalcitrant nature of these compounds, an effective mode of remediation has yet to be established. This study investigates the suitability of the use of phytoplankton for remediation efforts based on two criteria: the ability of phytoplankton strains to withstand the toxic effects of NAs, and their rate of biomass accumulation. A total of 21 phytoplankton strains were isolated from waters containing NAs, cultured, and maintained under unialgal conditions. These strains were then exposed to NAs in concentrations ranging from 0mg L(-1) to 1000mg L(-1) over a 14 day period. Inhibition of growth was observed at 30mg L(-1) NA (one strain), 100mg L(-1) NA (one strain), 300mg L(-1) NA (six strains), and 1000mg L(-1) NA (six strains). Five strains failed to show any growth inhibition at any test concentration and two strains could not be analysed due to poor growth during the test period. Strains were then ranked based on their suitability for use in remediation efforts. PMID:23031586

  3. Diets enriched in trans-11 vaccenic acid alleviate ectopic lipid accumulation in a rat model of NAFLD and metabolic syndrome.

    Jacome-Sosa, M Miriam; Borthwick, Faye; Mangat, Rabban; Uwiera, Richard; Reaney, Martin J; Shen, Jianheng; Quiroga, Ariel D; Jacobs, René L; Lehner, Richard; Proctor, Spencer D; Nelson, Randal C

    2014-07-01

    Trans11-18:1 (vaccenic acid, VA) is one of the most predominant naturally occurring trans fats in our food chain and has recently been shown to exert hypolipidemic effects in animal models. In this study, we reveal new mechanism(s) by which VA can alter body fat distribution, energy utilization and dysfunctional lipid metabolism in an animal model of obesity displaying features of the metabolic syndrome (MetS). Obese JCR:LA-cp rats were assigned to a control diet that included dairy-derived fat or the control diet supplemented with 1% VA. VA reduced total body fat (-6%), stimulated adipose tissue redistribution [reduced mesenteric fat (-17%) while increasing inguinal fat mass (29%)] and decreased adipocyte size (-44%) versus control rats. VA supplementation also increased metabolic rate (7%) concomitantly with an increased preference for whole-body glucose utilization for oxidation and increased insulin sensitivity [lower HOMA-IR (-59%)]. Further, VA decreased nonalcoholic fatty liver disease activity scores (-34%) and reduced hepatic (-27%) and intestinal (-39%) triglyceride secretion relative to control diet, while exerting differential transcriptional regulation of SREBP1 and FAS amongst other key genes in the liver and the intestine. Adding VA to dairy fat alleviates features of MetS potentially by remodeling adipose tissue and attenuating ectopic lipid accumulation in a rat model of obesity and MetS. Increasing VA content in the diet (naturally or by fortification) may be a useful approach to maximize the health value of dairy-derived fats. PMID:24775093

  4. Accumulation of non-superoxide anion reactive oxygen species mediates nitrogen-limited alcoholic fermentation by Saccharomyces cerevisiae

    Ferreira, Ana Mendes; Marques, Belém Sampaio; Barbosa, Catarina; Rodrigues, Fernando José dos Santos; Costa, Vitor; Faia, A. Mendes; Ludovico, Paula; Leão, Cecília

    2010-01-01

    Throughout alcoholic fermentation, nitrogen depletion is one of the most important environmental stresses that can negatively affect the yeast metabolic activity and ultimately leads to fermentation arrest. Thus, the identification of the underlying effects and biomarkers of nitrogen limitation is valuable for controlling, and therefore optimizing, alcoholic fermentation. In this study, reactive oxygen species (ROS), plasma membrane integrity, and cell cycle were evaluated in a wine strain of...

  5. Random amino acid mutations and protein misfolding lead to Shannon limit in sequence-structure communication.

    Andreas Martin Lisewski

    Full Text Available The transmission of genomic information from coding sequence to protein structure during protein synthesis is subject to stochastic errors. To analyze transmission limits in the presence of spurious errors, Shannon's noisy channel theorem is applied to a communication channel between amino acid sequences and their structures established from a large-scale statistical analysis of protein atomic coordinates. While Shannon's theorem confirms that in close to native conformations information is transmitted with limited error probability, additional random errors in sequence (amino acid substitutions and in structure (structural defects trigger a decrease in communication capacity toward a Shannon limit at 0.010 bits per amino acid symbol at which communication breaks down. In several controls, simulated error rates above a critical threshold and models of unfolded structures always produce capacities below this limiting value. Thus an essential biological system can be realistically modeled as a digital communication channel that is (a sensitive to random errors and (b restricted by a Shannon error limit. This forms a novel basis for predictions consistent with observed rates of defective ribosomal products during protein synthesis, and with the estimated excess of mutual information in protein contact potentials.

  6. ABA biosynthesis defective mutants reduce some free amino acids accumulation under drought stress in tomato leaves in comparison with Arabidopsis plants tissues

    Adnan Ali Al.Asbahi

    2012-05-01

    Full Text Available The ability of plants to tolerate drought conditions is crucial for plant survival and crop production worldwide. The present data confirm previous findings reported existence of a strong relation between abscisic acid (ABA content and amino acid accumulation as response water stress which is one of the most important defense mechanism activated during water stress in many plant species. Therefore, free amino acids were measured to determine any changes in the metabolite pool in relation to ABA content. The ABA defective mutants of Arabidopsis plants were subjected to leaf dehydration for Arabidopsis on Whatman 3 mm filter paper at room temperature while, tomato mutant plants were subjected to drought stresses for tomato plants by withholding water. To understand the signal transduction mechanisms underlying osmotic stress-regulating gene induction and activation of osmoprotectant free amino acid synthesizing genes, we carried out a genetic screen to isolate Arabidopsis mutants defective in ABA biosynthesis under drought stress conditions. The present results revealed an accumulation of specific free amino acid in water stressed tissues in which majority of free amino acids are increased especially those playing an osmoprotectant role such as proline and glycine. Drought stress related Amino acids contents are significantly reduced in the mutants under water stress condition while they are increased significantly in the wild types plants. The exhibited higher accumulation of other amino acids under stressed condition in the mutant plants suggest that, their expressions are regulated in an ABA independent pathways. In addition, free amino acids content changes during water stress condition suggest their contribution in drought toleration as common compatible osmolytes.

  7. Enhanced Photosynthesis and Growth in atquac1 Knockout Mutants Are Due to Altered Organic Acid Accumulation and an Increase in Both Stomatal and Mesophyll Conductance.

    Medeiros, David B; Martins, Samuel C V; Cavalcanti, João Henrique F; Daloso, Danilo M; Martinoia, Enrico; Nunes-Nesi, Adriano; DaMatta, Fábio M; Fernie, Alisdair R; Araújo, Wagner L

    2016-01-01

    Stomata control the exchange of CO2 and water vapor in land plants. Thus, whereas a constant supply of CO2 is required to maintain adequate rates of photosynthesis, the accompanying water losses must be tightly regulated to prevent dehydration and undesired metabolic changes. Accordingly, the uptake or release of ions and metabolites from guard cells is necessary to achieve normal stomatal function. The AtQUAC1, an R-type anion channel responsible for the release of malate from guard cells, is essential for efficient stomatal closure. Here, we demonstrate that mutant plants lacking AtQUAC1 accumulated higher levels of malate and fumarate. These mutant plants not only display slower stomatal closure in response to increased CO2 concentration and dark but are also characterized by improved mesophyll conductance. These responses were accompanied by increases in both photosynthesis and respiration rates, without affecting the activity of photosynthetic and respiratory enzymes and the expression of other transporter genes in guard cells, which ultimately led to improved growth. Collectively, our results highlight that the transport of organic acids plays a key role in plant cell metabolism and demonstrate that AtQUAC1 reduce diffusive limitations to photosynthesis, which, at least partially, explain the observed increments in growth under well-watered conditions. PMID:26542441

  8. Successful high-level accumulation of fish oil omega-3 long-chain polyunsaturated fatty acids in a transgenic oilseed crop.

    Ruiz-Lopez, Noemi; Haslam, Richard P; Napier, Johnathan A; Sayanova, Olga

    2014-01-01

    Omega-3 (also called n-3) long-chain polyunsaturated fatty acids (≥C20; LC-PUFAs) are of considerable interest, based on clear evidence of dietary health benefits and the concurrent decline of global sources (fish oils). Generating alternative transgenic plant sources of omega-3 LC-PUFAs, i.e. eicosapentaenoic acid (20:5 n-3, EPA) and docosahexaenoic acid (22:6 n-3, DHA) has previously proved problematic. Here we describe a set of heterologous genes capable of efficiently directing synthesis of these fatty acids in the seed oil of the crop Camelina sativa, while simultaneously avoiding accumulation of undesirable intermediate fatty acids. We describe two iterations: RRes_EPA in which seeds contain EPA levels of up to 31% (mean 24%), and RRes_DHA, in which seeds accumulate up to 12% EPA and 14% DHA (mean 11% EPA and 8% DHA). These omega-3 LC-PUFA levels are equivalent to those in fish oils, and represent a sustainable, terrestrial source of these fatty acids. We also describe the distribution of these non-native fatty acids within C. sativa seed lipids, and consider these data in the context of our current understanding of acyl exchange during seed oil synthesis. PMID:24308505

  9. Does aspartic acid racemization constrain the depth limit of the subsurface biosphere?

    Onstott, T. C. [Princeton University; Aubrey, A.D. [Jet Propulsion Laboratory, Pasadena, CA; Kieft, T L [New Mexico Institute of Mining and Technology; Silver, B J [Jet Propulsion Laboratory, Pasadena, CA; Phelps, Tommy Joe [ORNL; Van Heerden, E. [University of the Free State; Opperman, D. J. [University of the Free State; Bada, J L. [Geosciences Research Division, Scripps Instition of Oceanography, Univesity of California San Diego,

    2014-01-01

    Previous studies of the subsurface biosphere have deduced average cellular doubling times of hundreds to thousands of years based upon geochemical models. We have directly constrained the in situ average cellular protein turnover or doubling times for metabolically active micro-organisms based on cellular amino acid abundances, D/L values of cellular aspartic acid, and the in vivo aspartic acid racemization rate. Application of this method to planktonic microbial communities collected from deep fractures in South Africa yielded maximum cellular amino acid turnover times of ~89 years for 1 km depth and 27 C and 1 2 years for 3 km depth and 54 C. The latter turnover times are much shorter than previously estimated cellular turnover times based upon geochemical arguments. The aspartic acid racemization rate at higher temperatures yields cellular protein doubling times that are consistent with the survival times of hyperthermophilic strains and predicts that at temperatures of 85 C, cells must replace proteins every couple of days to maintain enzymatic activity. Such a high maintenance requirement may be the principal limit on the abundance of living micro-organisms in the deep, hot subsurface biosphere, as well as a potential limit on their activity. The measurement of the D/L of aspartic acid in biological samples is a potentially powerful tool for deep, fractured continental and oceanic crustal settings where geochemical models of carbon turnover times are poorly constrained. Experimental observations on the racemization rates of aspartic acid in living thermophiles and hyperthermophiles could test this hypothesis. The development of corrections for cell wall peptides and spores will be required, however, to improve the accuracy of these estimates for environmental samples.

  10. Does aspartic acid racemization constrain the depth limit of the subsurface biosphere?

    Onstott, T C; Magnabosco, C; Aubrey, A D; Burton, A S; Dworkin, J P; Elsila, J E; Grunsfeld, S; Cao, B H; Hein, J E; Glavin, D P; Kieft, T L; Silver, B J; Phelps, T J; van Heerden, E; Opperman, D J; Bada, J L

    2014-01-01

    Previous studies of the subsurface biosphere have deduced average cellular doubling times of hundreds to thousands of years based upon geochemical models. We have directly constrained the in situ average cellular protein turnover or doubling times for metabolically active micro-organisms based on cellular amino acid abundances, D/L values of cellular aspartic acid, and the in vivo aspartic acid racemization rate. Application of this method to planktonic microbial communities collected from deep fractures in South Africa yielded maximum cellular amino acid turnover times of ~89 years for 1 km depth and 27 °C and 1-2 years for 3 km depth and 54 °C. The latter turnover times are much shorter than previously estimated cellular turnover times based upon geochemical arguments. The aspartic acid racemization rate at higher temperatures yields cellular protein doubling times that are consistent with the survival times of hyperthermophilic strains and predicts that at temperatures of 85 °C, cells must replace proteins every couple of days to maintain enzymatic activity. Such a high maintenance requirement may be the principal limit on the abundance of living micro-organisms in the deep, hot subsurface biosphere, as well as a potential limit on their activity. The measurement of the D/L of aspartic acid in biological samples is a potentially powerful tool for deep, fractured continental and oceanic crustal settings where geochemical models of carbon turnover times are poorly constrained. Experimental observations on the racemization rates of aspartic acid in living thermophiles and hyperthermophiles could test this hypothesis. The development of corrections for cell wall peptides and spores will be required, however, to improve the accuracy of these estimates for environmental samples. PMID:24289240

  11. Arbuscular mycorrhiza increase artemisinin accumulation in Artemisia annua by higher expression of key biosynthesis genes via enhanced jasmonic acid levels.

    Mandal, Shantanu; Upadhyay, Shivangi; Wajid, Saima; Ram, Mauji; Jain, Dharam Chand; Singh, Ved Pal; Abdin, Malik Zainul; Kapoor, Rupam

    2015-07-01

    It is becoming increasingly evident that the formation of arbuscular mycorrhiza (AM) enhances secondary metabolite production in shoots. Despite mounting evidence, relatively little is known about the underlying mechanisms. This study suggests that increase in artemisinin concentration in Artemisia annua colonized by Rhizophagus intraradices is due to altered trichome density as well as transcriptional patterns that are mediated via enhanced jasmonic acid (JA) levels. Mycorrhizal (M) plants had higher JA levels in leaf tissue that may be due to induction of an allene oxidase synthase gene (AOS), encoding one of the key enzymes for JA production. Non-mycorrhizal (NM) plants were exogenously supplied with a range of methyl jasmonic acid concentrations. When leaves of NM and M plants with similar levels of endogenous JA were compared, these matched closely in terms of shoot trichome density, artemisinin concentration, and transcript profile of artemisinin biosynthesis genes. Mycorrhization increased artemisinin levels by increasing glandular trichome density and transcriptional activation of artemisinin biosynthesis genes. Transcriptional analysis of some rate-limiting enzymes of mevalonate and methyl erythritol phosphate (MEP) pathways revealed that AM increases isoprenoids by induction of the MEP pathway. A decline in artemisinin concentration in shoots of NM and M plants treated with ibuprofen (an inhibitor of JA biosynthesis) further confirmed the implication of JA in the mechanism of artemisinin production. PMID:25366131

  12. Dissimilation of carbon monoxide to acetic acid by glucose-limited cultures of Clostridium thermoaceticum

    Clostridium thermoaceticum was cultivated in glucose-limited media, and the dissimilation of CO to acetic acid was evaluated. The authors found that cultures catalyzed the rapid dissimilation of CO to acetic acid and CO2, with the stoichiometry obtained for conversion approximating that predicted from the following reaction: 4CO + 2H2O → CH3CO2H + 2CO2. Growing cultures formed approximately 50 mmol (3 g) of CO-derived acetic acid per liter of culture, with the rate of maximal consumption approximating 9.1 mmol of CO consumed/h per liter of culture. In contrast, resting cells were found not to dissimilate CO to acetic acid. 14CO was incorporated, with equal distribution between the carboxyl and methyl carbons of acetic acid when the initial cultivation gas phase was 100% CO whereas 14CO2 preferentially entered the carboxyl carbon when the initial gas phase was 100% CO2. Significantly, in the presence of saturating levels of CO, 14CO2 preferentially entered the methyl carbon, whereas saturating levels of CO2 yielded 14CO-derived labeling predominantly in the carboxyl carbon. These findings are discussed in relation to the path of carbon flow to acetic acid

  13. Accumulation of cellobiose lipids under nitrogen-limiting conditions by two ustilaginomycetous yeasts, Pseudozyma aphidis and Pseudozyma hubeiensis.

    Morita, Tomotake; Fukuoka, Tokuma; Imura, Tomohiro; Kitamoto, Dai

    2013-02-01

    Some basidiomycetous yeast strains extracellularly produce cellobiose lipids (CLs), glycolipid biosurfactants which have strong fungicidal activity. The representative CL producer Ustilago maydis produces CLs together with the other glycolipids, mannosylerythritol lipids (MELs); the preference of the two glycolipids is affected considerably by the nitrogen source. To develop new CL producers, 12 MEL producers were cultured under the nitrogen-limited conditions. Pseudozyma aphidis and Pseudozyma. hubeiensis were characterized as new CL producers. CL production was induced on three strains, P. aphidis, Pseudozyma graminicola, and P. hubeiensis under these conditions. The putative homologous genes of U. maydis cyp1, which encodes a P450 monooxygenase, essential for CL biosynthesis, were partially amplified from their genomic DNA. The nucleotide sequences of the gene fragments from P. hubeiensis and P. aphidis shared identities with U. maydis cyp1 of 99% and 78%, respectively. Furthermore, all of the deduced translation products are tightly clustered in the phylogenic tree of the monooxygenase. These results suggest that the genes involved with CL biosynthesis must be widely distributed in the basidiomycetous fungi as well as the MEL biosynthesis genes, and thus, the genus Pseudozyma has great potential as a biosurfactant producer. PMID:22985214

  14. Different responses of two Mosla species to potassium limitation in relation to acid rain deposition

    Meng WANG; Bao-jing GU; Ying GE; Zhen LIU; De-an JIANG; Scott X. CHANG; Jie CHANG

    2009-01-01

    The increasingly serious problem of acid rain is leading to increased potassium (K) loss from soils, and in our field investigation, we found that even congenerically relative Mosla species show different tolerance to K-deficiency. A hydroponic study was conducted on the growth of two Mosla species and their morphological, physiological and stoichiometric traits in response to limited (0.35 mmol K/L), normal (3.25 mmol K/L) and excessive (6.50 mmol K/L) K concentrations. Mosla hang-chowensis is an endangered plant, whereas Mosla dianthera a widespread weed. In the case of M. hangchowensis, in comparison with normal K concentration, K-limitation induced a significant reduction in net photosynthetic rate (Pn), soluble protein content, and superoxide dismutase (SOD) activity, but an increase in malondialdehyde (MDA) concentration. However, leaf mass ratio (LMR) and root mass ratio (RMR) were changed little by K-limitation. In contrast, for M. dianthera, K-limitation had little effect on Pn, soluble protein content, SOD activity, and MDA concentration, but increased LMR and RMR. Critical values of N (nitrogen):K and K:P (phosphorus) ratios in the shoots indicated that limitation in acquiring K occurred under K-limited conditions for M. hangchowensis but not for M. dianthera. We found that low K content in natural habitats was a restrictive factor in the growth and distribution of M. hangchowensis, and soil K-deficiency caused by acid rain worsened the situation of M. hangchowensis, while M. dianthera could well acclimate to the increasing K-deficiency. We suggest that controlling the acid rain and applying K fertilizers may be an effective way to rescue the endangered M. hangchowensis.

  15. The Na+ transporter, TaHKT1;5-D, limits shoot Na+ accumulation in bread wheat

    Byrt, Caitlin Siobhan

    2014-10-01

    Bread wheat (Triticum aestivum L.) has a major salt tolerance locus, Kna1, responsible for the maintenance of a high cytosolic K+/Na+ ratio in the leaves of salt stressed plants. The Kna1 locus encompasses a large DNA fragment, the distal 14% of chromosome 4DL. Limited recombination has been observed at this locus making it difficult to map genetically and identify the causal gene. Here, we decipher the function of TaHKT1;5-D, a candidate gene underlying the Kna1 locus. Transport studies using the heterologous expression systems Saccharomyces cerevisiae and Xenopus laevis oocytes indicated that TaHKT1;5-D is a Na+-selective transporter. Transient expression in Arabidopsis thaliana mesophyll protoplasts and in situ polymerase chain reaction indicated that TaHKT1;5-D is localised on the plasma membrane in the wheat root stele. RNA interference-induced silencing decreased the expression of TaHKT1;5-D in transgenic bread wheat lines which led to an increase in the Na+ concentration in the leaves. This indicates that TaHKT1;5-D retrieves Na+ from the xylem vessels in the root and has an important role in restricting the transport of Na+ from the root to the leaves in bread wheat. Thus, TaHKT1;5-D confers the essential salinity tolerance mechanism in bread wheat associated with the Kna1 locus via shoot Na+ exclusion and is critical in maintaining a high K+/Na+ ratio in the leaves. These findings show there is potential to increase the salinity tolerance of bread wheat by manipulation of HKT1;5 genes.

  16. Accumulation of nitrogen - a critical parameter for the calculation of load limits from nitrogen in forests; Akkumulering av nitrogen - en kritisk parameter for beregning av taalegrenser for nitrogen i skog

    Sogn, T.A.; Stuanes, A.O.; Abrahamsen, G.

    1996-01-01

    The conference paper deals with the accumulation of nitrogen in forests in Norway. The level of accumulation is a critical factor for the calculation of load limits. The paper compares the average rapidity values of accumulation since the last glacial age with the calculated values from the more short-lasting period based on data from surveying programs of the State Pollution Control Authority, manuring experiments, and other relevant research programs in this field. 8 refs., 1 fig., 1 tab.

  17. Yeast Extract and Silver Nitrate Induce the Expression of Phenylpropanoid Biosynthetic Genes and Induce the Accumulation of Rosmarinic Acid in Agastache rugosa Cell Culture

    Woo Tae Park

    2016-03-01

    Full Text Available The present study aimed to investigate the role of yeast extract and silver nitrate on the enhancement of phenylpropanoid pathway genes and accumulation of rosmarinic acid in Agastache rugosa cell cultures. The treatment of cell cultures with yeast extract (500 mg/L and silver nitrate (30 mg/L for varying times enhanced the expression of genes in the phenylpropanoid pathway and the production of rosmarinic acid. The results indicated that the expression of RAS and HPPR was proportional to the amount of yeast extract and silver nitrate. The transcript levels of HPPR under yeast extract treatment were 1.84-, 1.97-, and 2.86-fold higher than the control treatments after 3, 6, and 12 h, respectively, whereas PAL expression under silver nitrate treatment was 52.31-fold higher than in the non-treated controls after 24 h of elicitation. The concentration of rosmarinic acid was directly proportional to the concentration of the applied elicitors. Yeast extract supplementation documented the highest amount of rosmarinic acid at 4.98 mg/g, whereas silver nitrate addition resulted in a comparatively lower amount of rosmarinic acid at 0.65 mg/g. In conclusion, addition of yeast extract to the cell cultures enhanced the accumulation of rosmarinic acid, which was evidenced by the expression levels of the phenylpropanoid biosynthetic pathway genes in A. rugosa.

  18. Nucleic acids for recognition and catalysis: landmarks, limitations, and looking to the future.

    Perrin, D M

    2000-06-01

    Combinatorial selection of nucleic acids has led to the discovery of novel ligands and catalysts that have implications for both chemistry and medicine. In the context of combinatorial chemistry, degenerate syntheses of nucleic acid libraries readily generate as many as 10(15) different molecules in which a small percentage exhibit interesting binding and/or catalytic properties. The primary advantage of nucleic acids is that library coding is an intrinsic property; sequential composition directly determines the activity. At low temperatures, the sequential composition of single stranded nucleic acids governs folding into irregular tertiary structures resulting in interesting activities. At higher temperatures, the same structures are unfolded and decoded by polymerases to reveal sequential information. The use of PCR (polymerase chain reaction) permits amplification and thus enrichment of the selected activity which is then regenerated chemi-enzymatically. Iterative selection and amplification result in one of the highest throughput screens conceivable whereby each molecule encodes its own activity permitting the ultimate in parallel sampling. Finally, sequence information, and by extension the chemical composition, is obtained by simple sequencing techniques obviating the need for mass spectrometric deconvolution, parallel tagging, and/or large volumes needed for viral and cell culture. This review begins with an introduction of general concepts and considerations. The potential for nucleic acids to generate tight-binding ligands is of interest to structural biologists and medicinal chemists. The therapeutic implications to medicine are also touched upon. Since combinatorially selected nucleic acids and antibodies share many conceptual similarities, their respective advantages and limitations are compared. Theoretical and practical limitations for catalyst discovery are discussed along with the use of other chemical and physical approaches to address some current

  19. The effect of methyl jasmonate and phenolic acids on growth of seedlings and accumulation of anthocyanins in common buckwheat (Fagopyrum esculentum Moench

    Marcin Horbowicz

    2012-12-01

    Full Text Available The effect of methyl jasmonate (JA-Me and phenolic acids: trans-cinnamic acid (t-CA, p-coumaric acid (p-CA, salicylic acid (SA as well as naringenine (NAR on growth of seedlings and accumulation of anthocyanins in common buckwheat (Fagopyrum esculentum Moench were studied. JA-Me and phenolics were applied to growth medium of 4-days etiolated buckwheat seedlings before their exposition to day/night (16h/8h conditions. The increase of primary roots and hypocotyls length were measured after 3 days of seedling growth in such conditions. At the end of experiment the total anthocyanins contents were measured as well. Methyl jasmonate (JA-Me and trans-cinnamic acid (t-CA inhibited growth of the primary root in young buckwheat seedlings, while naringenine (NAR had a stimulatory influence, and p-coumaric acid had no effect at all. None of investigated phenolics or JA-Me had an effect on the growth of buckwheat hypocotyls, except the mixture of JA-Me and p-coumarcic acid. JA-Me significantly decreased the anthocyanins level in buckwheat hypocototyls, but not in cotyledons. trans-Cinnamic acid, p-coumaric acid and naringenine had no significant influence on the anthocyanin level in hypocotyls and cotyledons of buckwheat seedlings. Simultaneous treatment of buckwheat seedlings with JA-Me and t-CA or p-CA did not change the inhibition of anthocyanins accumulation in buckwheat hypocotyls by JA-Me. In the hypocotyls of buckwheat treated with a mixture of JA-Me and NAR, or SA, a synergistic reduction of anthocyanins was observed.

  20. Achieving Stable Nitritation for Mainstream Deammonification by Combining Free Nitrous Acid-Based Sludge Treatment and Oxygen Limitation

    Wang, Dongbo; Wang, Qilin; Laloo, Andrew; Xu, Yifeng; Bond, Philip L.; Yuan, Zhiguo

    2016-05-01

    Stable nitritation is a critical bottleneck for achieving autotrophic nitrogen removal using the energy-saving mainstream deammonification process. Herein we report a new strategy to wash out both the Nitrospira sp. and Nitrobacter sp. from the treatment of domestic-strength wastewater. The strategy combines sludge treatment using free nitrous acid (FNA) with dissolved oxygen (DO) control in the nitritation reactor. Initially, the nitrifying reactor achieved full conversion of NH4+ to NO3‑. Then, nitrite accumulation at ~60% was achieved in the reactor when 1/4 of the sludge was treated daily with FNA at 1.82 mg N/L in a side-stream unit for 24 h. Fluorescence in-situ hybridization (FISH) revealed FNA treatment substantially reduced the abundance of nitrite oxidizing bacteria (NOB) (from 23.0 ± 4.3 to 5.3 ± 1.9%), especially that of Nitrospira sp. (from 15.7 ± 3.9 to 0.4 ± 0.1%). Nitrite accumulation increased to ~80% when the DO concentration in the mainstream reactor was reduced from 2.5–3.0 to 0.3–0.8 mg/L. FISH revealed the DO limitation further reduced the abundance of NOB (to 2.1 ± 1.0%), especially that of Nitrobacter sp. (from 4.9 ± 1.2 to 1.8 ± 0.8%). The strategy developed removes a major barrier for deammonification in low-strength domestic wastewater.

  1. Dietary supplementation with phytosterol and ascorbic acid reduces body mass accumulation and alters food transit time in a diet-induced obesity mouse model

    Kozlowski Petri

    2011-06-01

    Full Text Available Abstract Previous research indicates that animals fed a high fat (HF diet supplemented with disodium ascorbyl phytostanyl phosphate (DAPP exhibit reduced mass accumulation when compared to HF control. This compound is a water-soluble phytostanol ester and consists of a hydrophobic plant stanol covalently bonded to ascorbic acid (Vitamin C. To provide insight into the mechanism of this response, we examined the in vivo effects of a high fat diet supplemented with ascorbic acid (AA in the presence and absence of unesterified phytosterols (PS, and set out to establish whether the supplements have a synergistic effect in a diet-induced obesity mouse model. Our data indicate that HF diet supplementation with a combination of 1% w/w phytosterol and 1% w/w ascorbic acid results in reduced mass accumulation, with mean differences in absolute mass between PSAA and HF control of 10.05%; and differences in mass accumulation of 21.6% (i.e. the PSAA group gained on average 21% less mass each week from weeks 7-12 than the HF control group. In our previous study, the absolute mass difference between the 2% DAPP and HF control was 41%, while the mean difference in mass accumulation between the two groups for weeks 7-12 was 67.9%. Mass loss was not observed in animals supplemented with PS or AA alone. These data suggest that the supplements are synergistic with respect to mass accumulation, and the esterification of the compounds further potentiates the response. Our data also indicate that chronic administration of PS, both in the presence and absence of AA, results in changes to fecal output and food transit time, providing insight into the possibility of long-term changes in intestinal function related to PS supplementation.

  2. Characterization of major ripening events during softening in grape: turgor, sugar accumulation, abscisic acid metabolism, colour development, and their relationship with growth.

    Castellarin, Simone D; Gambetta, Gregory A; Wada, Hiroshi; Krasnow, Mark N; Cramer, Grant R; Peterlunger, Enrico; Shackel, Kenneth A; Matthews, Mark A

    2016-02-01

    Along with sugar accumulation and colour development, softening is an important physiological change during the onset of ripening in fruits. In this work, we investigated the relationships among major events during softening in grape (Vitis vinifera L.) by quantifying elasticity in individual berries. In addition, we delayed softening and inhibited sugar accumulation using a mechanical growth-preventing treatment in order to identify processes that are sugar and/or growth dependent. Ripening processes commenced on various days after anthesis, but always at similarly low elasticity and turgor. Much of the softening occurred in the absence of other changes in berry physiology investigated here. Several genes encoding key cell wall-modifying enzymes were not up-regulated until softening was largely completed, suggesting softening may result primarily from decreases in turgor. Similarly, there was no decrease in solute potential, increase in sugar concentration, or colour development until elasticity and turgor were near minimum values, and these processes were inhibited when berry growth was prevented. Increases in abscisic acid occurred early during softening and in the absence of significant expression of the V. vinifera 9-cis-epoxycarotenoid dioxygenases. However, these increases were coincident with decreases in the abscisic acid catabolite diphasic acid, indicating that initial increases in abscisic acid may result from decreases in catabolism and/or exogenous import. These data suggest that softening, decreases in turgor, and increases in abscisic acid represent some of the earliest events during the onset of ripening. Later, physical growth, further increases in abscisic acid, and the accumulation of sugar are integral for colour development. PMID:26590311

  3. Limiting amino acids in an 11% crude protein corn-soybean meal diet for growing pigs.

    Russell, L E; Kerr, B J; Easter, R A

    1987-11-01

    Three experiments were conducted to test the hypothesis that methionine, isoleucine, valine or nitrogen either singly or in combination are limiting in an 11% crude protein, lysine-tryptophan-threonine-supplemented, corn-soybean meal diet for growing pigs. A 16% crude protein diet was used as a positive control in each experiment and all amino acid additions were made, at a minimum, to equal requirements. Average initial weights were 21.3 kg, 23.0 kg and 19.1 kg in Exp. 1, 2 and 3, respectively. The experiments averaged 4 wk in duration. In Exp. 1 and 2, neither the addition of glutamic acid as a source of nitrogen, nor methionine to the 11% diet resulted in any improvement (P greater than .20) in rate or efficiency of growth. Addition of the combination of isoleucine and valine to the 11% diet resulted in an increase (P less than .05) in both growth rate and feed efficiency to a level not different (P greater than .20) from that of the pigs consuming the positive control diet. The addition of valine to the 11% crude protein diet with supplemental lysine, tryptophan and threonine (Exp. 3) caused an improvement in daily gain (P less than .05) but not feed efficiency (P greater than .10). Isoleucine addition tended to reduce pig performance. The results of these experiments suggest that an 11% crude protein, corn-soybean meal diet fortified with lysine, tryptophan and threonine is not limiting in sulfur amino acids or nitrogen. Valine may be the only limiting amino acid. PMID:3693151

  4. Suppression of γ-Aminobutyric Acid (GABA) Transaminases Induces Prominent GABA Accumulation, Dwarfism and Infertility in the Tomato (Solanum lycopersicum L.)

    Koike, Satoshi; Matsukura, Chiaki; Takayama, Mariko; Asamizu, Erika; Ezura, Hiroshi

    2013-01-01

    Tomatoes accumulate γ-aminobutyric acid (GABA) at high levels in the immature fruits. GABA is rapidly converted to succinate during fruit ripening through the activities of GABA transaminase (GABA-T) and succinate semialdehyde dehydrogenase (SSADH). Although three genes encoding GABA-T and both pyruvate- and α-ketoglutarate-dependent GABA-T activities have been detected in tomato fruits, the mechanism underlying the GABA-T-mediated conversion of GABA has not been fully understood. In this wor...

  5. Perfluoroalkyl Acids (PFAAs) and Selected Precursors in the Baltic Sea Environment: Do Precursors Play a Role in Food Web Accumulation of PFAAs?

    Gebbink, Wouter A; Bignert, Anders; Berger, Urs

    2016-06-21

    The present study examined the presence of perfluoroalkyl acids (PFAAs) and selected precursors in the Baltic Sea abiotic environment and guillemot food web, and investigated the relative importance of precursors in food web accumulation of PFAAs. Sediment, water, zooplankton, herring, sprat, and guillemot eggs were analyzed for perfluoroalkane sulfonic acids (PFSAs; C4,6,8,10) and perfluoroalkyl carboxylic acids (PFCAs; C6-15) along with six perfluoro-octane sulfonic acid (PFOS) precursors and 11 polyfluoroalkyl phosphoric acid diesters (diPAPs). FOSA, FOSAA and its methyl and ethyl derivatives (Me- and EtFOSAA), and 6:2/6:2 diPAP were detected in sediment and water. While FOSA and the three FOSAAs were detected in all biota, a total of nine diPAPs were only detected in zooplankton. Concentrations of PFOS precursors and diPAPs exceeded PFOS and PFCA concentrations, respectively, in zooplankton, but not in fish and guillemot eggs. Although PFOS precursors were present at all trophic levels, they appear to play a minor role in food web accumulation of PFOS based on PFOS precursor/PFOS ratios and PFOS and FOSA isomer patterns. The PFCA pattern in fish could not be explained by the intake pattern based on PFCAs and analyzed precursors, that is, diPAPs. Exposure to additional precursors might therefore be a dominant exposure pathway compared to direct PFCA exposure for fish. PMID:27192404

  6. Naturally evolved enhanced Cd tolerance of Dianthus carthusianorum L. is not related to accumulation of thiol peptides and organic acids

    Wójcik, Małgorzata; DRESLER, Sławomir; Plak, Andrzej; Tukiendorf, Anna

    2014-01-01

    Two contrasting ecotypes of Dianthus carthusianorum L., metallicolous (M) and nonmetallicolous (NM), were cultivated in hydroponics at 0–50 μM Cd for 14 days to compare their Cd accumulation, sensitivity and tolerance mechanisms. While both ecotypes contained similar concentrations of Cd in the shoots and roots, the M ecotype was more Cd-tolerant (as measured by fresh weight production and root and leaf viability). Both ecotypes accumulated phytochelatins (PCs) in response to Cd with a higher...

  7. Accumulated SET protein up-regulates and interacts with hnRNPK, increasing its binding to nucleic acids, the Bcl-xS repression, and cellular proliferation

    Almeida, Luciana O.; Garcia, Cristiana B.; Matos-Silva, Flavia A. [Department of Clinical Analyses, Toxicology and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP (Brazil); Curti, Carlos [Department of Physics and Chemistry, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP (Brazil); Leopoldino, Andréia M., E-mail: andreiaml@usp.br [Department of Clinical Analyses, Toxicology and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP (Brazil)

    2014-02-28

    Highlights: • hnRNPK is a new target of SET. • SET regulates hnRNPK. • SET and hnRNPK accumulation promotes tumorigenesis. • SET accumulation is a potential model to study genes regulated by SET-hnRNPK. - Abstract: SET and hnRNPK are proteins involved in gene expression and regulation of cellular signaling. We previously demonstrated that SET accumulates in head and neck squamous cell carcinoma (HNSCC); hnRNPK is a prognostic marker in cancer. Here, we postulate that SET and hnRNPK proteins interact to promote tumorigenesis. We performed studies in HEK293 and HNSCC (HN6, HN12, and HN13) cell lines with SET/hnRNPK overexpression and knockdown, respectively. We found that SET and/or hnRNPK protein accumulation increased cellular proliferation. SET accumulation up-regulated hnRNPK mRNA and total/phosphorylated protein, promoted hnRNPK nuclear location, and reduced Bcl-x mRNA levels. SET protein directly interacted with hnRNPK, increasing both its binding to nucleic acids and Bcl-xS repression. We propose that hnRNPK should be a new target of SET and that SET–hnRNPK interaction, in turn, has potential implications in cell survival and malignant transformation.

  8. Crossing the pedogenetic threshold: Apparent phosphorus limitation by soil microorganisms in unglaciated acidic eastern hardwood forests

    Deforest, J. L.; Smemo, K. A.; Burke, D. J.

    2010-12-01

    The availability of soil phosphorus (P) can significantly influence microbial community composition and the ecosystem-level processes they mediate. However, the threshold at which soil microorganisms become functionally P-limited is unclear because of soil acidity effect on P availability. We reason that acidic temperate hardwood forest ecosystems are, in fact, functionally P-limited, but compensation occur via soil microbial production of phosphatase enzymes. We tested this hypothesis in glaciated and unglaciated mature mixed-mesophytic forests in eastern Ohio where both soil pH and P availability had been experientially manipulated. We measured the activity of two P acquiring soil enzymes, phosphomonoesterase (PMono) and phosphodiesterase (PDi), to understand how soil acidity and available P influence microbial function. Our experimental treatments elevated ambient soil pH from below 4.5 to around 5.5 and increased readily available phosphate from 3 to ~25 mg P/kg on glaciated soils and from 0.5 to ~5 mg P/kg on unglaciated soils. The P treatment decreased the activity of PDi by 82% relative to the control on unglaciated soils, but we observed no P treatment effect on glaciated soils. A similar result was observed for PMono. Soil pH, alone, did not significantly influence enzyme activities. Results suggest that soil microorganisms are more likely to be P-limited in older unglaciated soils. However, dramatically higher phosphatase activity in response to very low P availability suggests that an underlying ecosystem P limitation can be ameliorated by soil microbial community dynamics. This mechanism may be more important for older, unglaciated soils that have already crossed a pedogenic threshold where P availability influences ecosystem and microbial function.

  9. Anthocyanins and phenolic acids from a wild blueberry (Vaccinium angustifolium) powder counteract lipid accumulation in THP-1-derived macrophages

    Del Bo', Cristian; Cao, Yi; Roursgaard, Martin;

    2016-01-01

    PURPOSE: Blueberries are a rich source of anthocyanins (ACNs) and phenolic acids (PA), which are hypothesized to protect against development of atherosclerosis. The present study examined the effect of an ACN- and PA-rich fractions, obtained from a wild blueberry powder, on the capacity to counte....... CONCLUSIONS: The results demonstrated a potential role of both the ACN- and PA-rich fractions and single compounds in the lipid accumulation also at concentrations close to that achievable in vivo.......PURPOSE: Blueberries are a rich source of anthocyanins (ACNs) and phenolic acids (PA), which are hypothesized to protect against development of atherosclerosis. The present study examined the effect of an ACN- and PA-rich fractions, obtained from a wild blueberry powder, on the capacity to...... concentrations (from 0.05 to 10 μg mL(-1)) of ACN- and PA-rich fractions, pure ACN standards (malvidin, delphinidin and cyanidin 3-glucoside), and metabolites (syringic, gallic and protocatechuic acids). Lipid accumulation was quantified with the fluorescent dye Nile red. RESULTS: Lipid accumulation was reduced...

  10. Ability of Agrogyron elongatum to accumulate the single metal of cadmium, copper, nickel and lead and root exudation of organic acids

    2001-01-01

    Agrogyron elongatum were grown in nutrient solution containing moderate to high amounts of separate heavy metal of Cd, Cu, Ni and Pb in a greenhouse for a 9-day. Cd, Cu, Ni and Pb generally led to decrease in the elongation of roots although the length of seedlings exposed to Cd and Pb at 0,05 and 0.5 mg/L showed to be slightly greater than that of controls. Of the four metals in the experiment, Pb was absorbed and accumulated to the highest level, with the concentrations of 92754 mg/kg dry weight (DW) in roots and 11683 mg/kg DW in shoots. Cd was moderately accumulated in Agrogyron elongatum, but the maximum bioaccumulation coefficients (BCs) for rpots and shoots were observed. The patterns for Cu and Ni uptake and distribution in plants differed from those of Pb and Cd, as it was showed that the shoot accumulation of Cu and Ni was significantly higher than in roots. A. elongatum had the highest Ni concentration in shoots (30261 mg/kg DW)at the external concentration of 250 mg/L. Cu ranked second, with a shoot concentration of 12230 mg/kg DW when 50 mg/L Cu in solution was applied. For the four trace elements tested, the highest concentrations in shoots decreased by the order of Ni > Cu > Pb > Cd (mg/kg DW),and those in roots were Pb > Cd > Ni > Cu (mg/kg DW). Malic, oxalic and citric acids exuded by roots exposed to 1 and 50 mg/L of the metals were detected. Release of organic acids from plants significantly differed among the metal treatments. Cu was most effectively in inducing rpot exudation of the three types of organic acids. Cd, and Ni were also the inducers of secretion of malic and oxalic acids. With reference of Pb,a small amounts of malic and oxalic acids were detected in the root exudates, but few quantities of citric acid were found. However, no orrelation between alternations in root exudation of organic acids and metal accumulation could be established.

  11. Predator evasion in zooplankton is suppressed by polyunsaturated fatty acid limitation.

    Brzeziński, Tomasz; von Elert, Eric

    2015-11-01

    Herbivorous zooplankton avoid size-selective predation by vertical migration to a deep, cold water refuge. Adaptation to low temperatures in planktonic poikilotherms depends on essential dietary lipids; the availability of these lipids often limits growth and reproduction of zooplankton. We hypothesized that limitation by essential lipids may affect habitat preferences and predator avoidance behavior in planktonic poikilotherms. We used a liposome supplementation technique to enrich the green alga Scenedesmus obliquus and the cyanobacterium Synecchococcus elongatus with the essential lipids, cholesterol and eicosapentaenoic acid (EPA), and an indoor system with a stratified water-column (plankton organ) to test whether the absence of these selected dietary lipids constrains predator avoidance (habitat preferences) in four species of the key-stone pelagic freshwater grazer Daphnia. We found that the capability of avoiding fish predation through habitat shift to the deeper and colder environment was suppressed in Daphnia unless the diet was supplemented with EPA; however, the availability of cholesterol did not affect habitat preferences of the tested taxa. Thus, their ability to access a predator-free refuge and the outcome of predator-prey interactions depends upon food quality (i.e. the availability of an essential fatty acid). Our results suggest that biochemical food quality limitation, a bottom-up factor, may affect the top-down control of herbivorous zooplankton. PMID:26232092

  12. Limitations to ruminal absorption of volatile fatty acids in lactating dairy cows

    Storm, Adam Christian

    ruminal overproduction of VFA represents a possible health risk. A challenge of the lactating dairy cow is to avoid acidic overload of the rumen while satisfying the nutritional demand of the peripheral tissue. Thus, the overall objective of the Ph.D. study was to detect and quantify possible limitations......The symbiotic relationship between ruminants and the microbial inhabitants of the rumen constitutes a unique feature of the ruminant digestive system. Through the microbial utilization of feed carbohydrates and protein in the rumen, substantial amounts of fermentation products and microbial cell...... bodies are released for the benefit of the host animal. The main end product of ruminal fermentation is volatile fatty acids (VFA), which provide the cow with the majority of energetic precursors for metabolic processes. Ruminal VFA are therefore, quantitatively the most important nutrient in cattle, but...

  13. Effects of Limiting Amino Acids on Rumen Fermentation and Microbial Community In vitro

    2008-01-01

    Three goats fitted with cannula were used to provide rumen liquor to investigate the effects of limiting amino acids on rumen fermentation and microbial community in vitro. The removal method was used in the current experiments. Treatments are total essential amino acid (TEAA), His-removal, Lys-removal, Met-removal, and branch chain amino acid (BCAA)-removal. Results indicated that, pH-value ranged between 5.9 and 6.8, with the highest mean value for the group with BCAA-removal (6.54) in the culture. Concentration of NH3-N ranged between 10.99 to 30.51 mg 100 mL-1, with the group of TEAA recording the highest average NH3-N concentration (17.85 mg 100 mL-1). Yields of microbial protein and limiting degree on microbial growth varied with treatments (P < 0.01), and the lowest accrued in treatment with BCAA-removal (0.1389, 0.1772, and 0.3161 mg mL-1 for bacteria, protozoa, and mixed microbes, respectively), compared to the group with TEAA, microbial production of mixed microbes decreased by 44.52%. As for micro-flora, protozoa to bacteria ratio was the lowe st for the group with Lys-removal (89.12%), while the h i ghe st for the group with B CAA-removal (127.60%) (P < 0.01). Furthermore, PCR-SSCP analysis revealed that, microbial profile subjected to substrates within bacteria and protozoa groups. It was therefore concluded that, dietary amino acid influenced both rumen fermentation and microbial characteristics.

  14. The Unusual Acid-Accumulating Behavior during Ripening of Cherimoya (Annona cherimola Mill.) is Linked to Changes in Transcription and Enzyme Activity Related to Citric and Malic Acid Metabolism.

    González-Agüero, Mauricio; Tejerina Pardo, Luis; Zamudio, María Sofía; Contreras, Carolina; Undurraga, Pedro; Defilippi, Bruno G

    2016-01-01

    Cherimoya (Annona cherimola Mill.) is a subtropical fruit characterized by a significant increase in organic acid levels during ripening, making it an interesting model for studying the relationship between acidity and fruit flavor. In this work, we focused on understanding the balance between the concentration of organic acids and the gene expression and activity of enzymes involved in the synthesis and degradation of these metabolites during the development and ripening of cherimoya cv. "Concha Lisa". Our results showed an early accumulation of citric acid and other changes associated with the accumulation of transcripts encoding citrate catabolism enzymes. During ripening, a 2-fold increase in malic acid and a 6-fold increase in citric acid were detected. By comparing the contents of these compounds with gene expression and enzymatic activity levels, we determined that cytoplasmic NAD-dependent malate dehydrogenase (cyNAD-MDH) and mitochondrial citrate synthase (mCS) play important regulatory roles in the malic and citric acid biosynthetic pathways. PMID:27120592

  15. Accumulation of 3-hydroxytetradecenoic acid: Cause or corollary of glucolipotoxic impairment of pancreatic β-cell bioenergetics?

    Nicolai M. Doliba

    2015-12-01

    Conclusions: As long chain 3-hydroxylated FA metabolites are known to uncouple heart and brain mitochondria [53–55], we propose that under glucolipotoxic condition, unsaturated hydroxylated long-chain FAs accumulate, uncouple and ultimately inhibit β-cell respiration. This leads to the slow deterioration of mitochondrial function progressing to bioenergetics β-cell failure.

  16. The potato suberin feruloyl transferase FHT which accumulates in the phellogen is induced by wounding and regulated by abscisic and salicylic acids.

    Boher, Pau; Serra, Olga; Soler, Marçal; Molinas, Marisa; Figueras, Mercè

    2013-08-01

    The present study provides new insights on the role of the potato (Solanum tuberosum) suberin feruloyl transferase FHT in native and wound tissues, leading to conclusions about hitherto unknown properties of the phellogen. In agreement with the enzymatic role of FHT, it is shown that its transcriptional activation and protein accumulation are specific to tissues that undergo suberization such as the root boundary layers of the exodermis and the endodermis, along with the tuber periderm. Remarkably, FHT expression and protein accumulation within the periderm is restricted to the phellogen derivative cells with phellem identity. FHT levels in the periderm are at their peak near harvest during periderm maturation, with the phellogen becoming meristematically inactive and declining thereafter. However, periderm FHT levels remain high for several months after harvest, suggesting that the inactive phellogen retains the capacity to synthesize ferulate esters. Tissue wounding induces FHT expression and the protein accumulates from the first stages of the healing process onwards. FHT is up-regulated by abscisic acid and down-regulated by salicylic acid, emphasizing the complex regulation of suberin synthesis and wound healing. These findings open up new prospects important for the clarification of the suberization process and yield important information with regard to the skin quality of potatoes. PMID:23918964

  17. Tailoring Conformation-Induced Chromism of Polythiophene Copolymers for Nucleic Acid Assay at Resource Limited Settings.

    Rajwar, Deepa; Ammanath, Gopal; Cheema, Jamal Ahmed; Palaniappan, Alagappan; Yildiz, Umit Hakan; Liedberg, Bo

    2016-04-01

    Here we report on the design and synthesis of cationic water-soluble thiophene copolymers as reporters for colorimetric detection of microRNA (miRNA) in human plasma. Poly(3-alkoxythiophene) (PT) polyelectrolytes with controlled ratios of pendant groups such as triethylamine/1-methyl imidazole were synthesized for optimizing interaction with target miRNA sequence (Tseq). Incorporation of specific peptide nucleic acid (PNA) sequences with the cationic polythiophenes yielded distinguishable responses upon formation of fluorescent PT-PNA-Tseq triplex and weakly fluorescent PT-Tseq duplex, thereby enabling selective detection of target miRNA. Unlike homopolymers of PT (hPT), experimental results indicate the possibility of utilizing copolymers of PT (cPT) with appropriate ratios of pendant groups for miRNA assay in complex matrices such as plasma. As an illustration, colorimetric responses were obtained for lung cancer associated miRNA sequence (mir21) in human plasma, with a detection limit of 10 nM, illustrating the feasibility of proposed methodology for clinical applications without involving sophisticated instrumentation. The described methodology therefore possesses high potential for low-cost nucleic acid assays in resource-limited settings. PMID:26956217

  18. Effect of Soil Moisture on Release of Low-MolecularWeight Organic Acids in Root Exudates and the Accumulation of Iron in Root Apoplasm of Peanut

    2000-01-01

    A three-compartments rhizobox was designed and used to study the low-molecular-weight organic acids in root exudates and the root apoplastic iron of "lime-induced chlorosis" peanut grown on a calcareous soil in relation to different soil moisture conditions. Results showed that chlorosis of peanuts developed under condition of high soil moisture level (250 g kg-1), while peanuts grew well and chlorosis did not develop when soil moisture was managed to a normal level (150 g kg-1). The malic acid, maleic acid and succinic acid contents of chlorotic peanut increased by 108.723, 0.029 and 22.446μg cm-2, respectively,compared with healthy peanuts. The content of citric acid and fumaric acid also increased in root exudates of chlorotic peanuts. On Days 28 and 42 of peanut growth, the accumulation of root apoplastic iron in chlorotic peanuts was higher than that of healthy peanuts. From Day 28 to Day 42, the mobilization percentages of chlorotic peanuts and healthy peanuts to root apoplastic iron were almost the same, being 52.4% and 52.8%,respectively, indicating that the chlorosis might be caused by the inactivation of iron within peanut plant grown on a calcareous soil under high soil moisture conditions.

  19. Plant regeneration and biochemical accumulation of hydroxybenzoic and hydroxycinnamic acid derivatives in Hypoxis hemerocallidea organ and callus cultures

    Moyo, M.; Amoo, S.O.; Aremu, A.O.; Grúz, Jiří; Šubrtová, Michaela; Doležal, Karel; van Staden, J.

    2014-01-01

    Roč. 227, OCT 2014 (2014), s. 157-164. ISSN 0168-9452 R&D Projects: GA MŠk(CZ) LO1204 Institutional support: RVO:61389030 Keywords : Antioxidants * Hydroxybenzoic acids * Hydroxycinnamic acids Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.607, year: 2014

  20. Crassulacean acid metabolism under severe light limitation: a matter of plasticity in the shadows?

    Ceusters, Johan; Borland, Anne M; Godts, Christof; Londers, Elsje; Croonenborghs, Sarah; Van Goethem, Davina; De Proft, Maurice P

    2011-01-01

    Despite the increased energetic costs of CAM compared with C(3) photosynthesis, it is hypothesized that the inherent photosynthetic plasticity of CAM allows successful acclimation to light-limiting conditions. The present work sought to determine if CAM presented any constraints to short and longer term acclimation to light limitation and to establish if and how metabolic and photosynthetic plasticity in the deployment of the four phases of CAM might facilitate acclimation to conditions of deep shade. Measurements of leaf gas exchange, organic acids, starch and soluble sugar (glucose, fructose, and sucrose) contents were made in the leaves of the constitutive CAM bromeliad Aechmea 'Maya' over a three month period under severe light limitation. A. 'Maya' was not particularly tolerant of severe light limitation in the short term. A complete absence of net CO(2) uptake and fluctuations in key metabolites (i.e. malate, starch or soluble sugars) indicated a dampened metabolism whilst cell death in the most photosynthetically active leaves was attributed to an over-acidification of the cytoplasm. However, in the longer term, plasticity in the use of the different phases of gas exchange and different storage carbohydrate pools, i.e. a switch from starch to sucrose as the major carbohydrate source, ensured a positive carbon balance for this CAM species under extremely low levels of irradiance. As such, co-ordinated plasticity in the use of C(3) and C(4) carboxylases and different carbohydrate pools together with an increase in the abundance of light-harvesting complexes, appear to underpin the adaptive radiation of the energetically costly CAM pathway within light-limiting environments such as wet cloud forests and shaded understoreys of tropical forests. PMID:20861137

  1. Antifungal canthin-6-one series accumulate in lipid droplets and affect fatty acid metabolism in Saccharomyces cerevisiae

    Lagoutte, D.; Nicolas, V; Poupon, E.; Fournet, Anne; Hocquemiller, R.; Libong, D.; Chaminade, P.; Loiseau, P.M.

    2008-01-01

    The mechanism of action of antifungal canthin-6-one series was investigated in Saccharomyces cerevisiae. After a rapid uptake, a preferential accumulation of the drug within lipid droplets was observed. The antifungal action of canthin-6-one was found as reversible. Canthin-6-one did not exhibit affinity for sterols, and membrane ergosterol was not necessary for the antifungal activity since the MICs were similar on an ergosterol-deleted and the wild-type S. cerevisiae clones. Relative amount...

  2. Induced Protoporphyrin IX Accumulation by the δ-Aminolevulinic Acid in Bacteria and its Potential Use in the Photodynamic Therapy

    Brígido-Aparicio, Cyntiha; Ramón-Gallegos, Eva; Arenas-Huertero, Francisco Jesús; Uribe-Hernández, Raúl

    2008-08-01

    The increasing incident of resistant strains to antibiotic has encouraged the search of new antibacterial treatments, such as the photodynamic therapy. In recent years, photodynamic therapy has demonstrated being a good technology for the treatment of recurrent bacteria infection. PDT presents a hopeful approach to eliminate Gram positive and negative bacteria in immunological compromised patients. This therapy uses a laser in combination with a photosensibilizer in presence of intracellular molecular oxygen. The process generates an effect of phototoxicity in bacterial cells. The aim of this work was to determine the in vitro conditions to accumulate PpIX in effective concentrations in Staphylococcus aureus ATCC25923 and Streptococcus pyogenes, which are responsible of human cutaneous diseases. A cellular suspension of both strains was prepared in TSB to obtain growth in Log-phase, then, the suspensions were adjusted to a final concentration of 2.61×108 cells/mL. The strains were exposed to increasing concentrations from 0 to 160μg/mL of δ-ALA in order to determinate the concentration that induces the biggest accumulation of PpIX. PpIX was measured using the Piomelli method modified for bacteria. The concentration selected was 40 mg/mL of ALA. It was found that in basal concentration of δ-ALA (0 μg/mL) both strains accumulated similar amount of PpIX. In concentrations of 5 mg/mL of δ-ALA it was observed a significant (paureus ATCC25923 accumulated significantly the biggest concentration of PpIX with regard to S. pyogenes. In conclusion, it was found that the optimal conditions to apply PDT will be to expose both strains to 40 mg/mL of ALA and to irradiate at 24 h after the exposition.

  3. Increased placental fatty acid transporter 6 and binding protein 3 expression and fetal liver lipid accumulation in a mouse model of obesity in pregnancy.

    Díaz, Paula; Harris, Jessica; Rosario, Fredrick J; Powell, Theresa L; Jansson, Thomas

    2015-12-15

    Obesity in pregnancy is associated with increased fetal growth and adiposity, which, in part, is determined by transplacental nutrient supply. Trophoblast uptake and intracellular trafficking of lipids are dependent on placental fatty acid transport proteins (FATP), translocase (FAT/CD36), and fatty acid binding proteins (FABP). We hypothesized that maternal obesity in mice leads to increased placental expression of FAT/CD36, FATPs, and FABPs, and lipid accumulation in the fetal liver. C57/BL6J female mice were fed either a control (C; n = 10) or an obesogenic (OB; n = 10) high-fat, high-sugar diet before mating and throughout pregnancy. At E18.5, placentas and fetal livers were collected. Trophoblast plasma membranes (TPM) were isolated from placental homogenates. Expression of FAT/CD36 and FATP (TPM) and FABP (homogenates) was determined by immunoblotting. Gene expression was assessed by RT-quantitative PCR. Sections of fetal livers were stained for Oil Red O, and lipid droplets were quantified. TPM protein expression of FAT/CD36, FATP 2, and FATP 4 was comparable between C and OB groups. Conversely, TPM FATP 6 expression was increased by 35% in OB compared with C placentas without changes in mRNA expression. FABPs 1, 3-5 and PPARγ were expressed in homogenates, and FABP 3 expression increased 27% in OB compared with C placentas; however, no changes were observed in mRNA expression. Lipid droplet accumulation was 10-fold higher in the livers of fetuses from OB compared with C group. We propose that increased lipid transport capacity in obese mice promotes transplacental fatty acid transport and contributes to excess lipid accumulation in the fetal liver. PMID:26491104

  4. Limitation of fault-sealing and its control on hydrocarbon accumulation-An example from the Laoyemiao Oilfield of the Nanpu Sag

    Jiang Zhenxue; Dong Yuexia; Li Hongyi; Liu Luofu; Liu Guangdi; Li Xiaoying

    2008-01-01

    Based on previous studies on the internal structures of fault belts, the fault belts in the Laoyemiao Oilfieid of the Nanpu Sag can be divided into three units, a crushed zone, an upper induced fracture zone and a lower induced fracture zone according to the log response characteristics. The upper induced fracture zone is characterized by the development of pervasive fractures and has a poor sealing or non-sealing capability. It therefore can act as pathways for hydrocarbon migration. The lower induced fracture zone consists of fewer fractures and has limited sealing capability. The crushed zone has a good sealing capability comparable to mudstone and can thus prevent lateral migration of fluid.Through physical modeling and comparing laboratory data with calculated data of oil column heights of traps sealed by faults, it is concluded that the fault-sealing capability for oil and gas is limited. When the oil column height reaches a threshold, oil will spill over from the top of reservoir along the lower induced fracture zone under the action of buoyancy, and the size of reservoir will remain unchanged.Analysis of the formation mechanisms of the fault-sealed reservoirs in the Nanpu Sag indicated that the charging sequence of oil and gas in the reservoir was from lower formation to upper formation, with the fault playing an important role in oil and gas accumulation. The hydrocarbon potential in reverse faultsealed traps is much better than that in the consequent fault-sealed traps. The reverse fault-sealed traps are favorable and preferred exploration targets.

  5. Rice bran oil and oryzanol reduce plasma lipid and lipoprotein cholesterol concentrations and aortic cholesterol ester accumulation to a greater extent than ferulic acid in hypercholesterolemic hamsters.

    Wilson, Thomas A; Nicolosi, Robert J; Woolfrey, Benjamin; Kritchevsky, David

    2007-02-01

    plasma triglyceride concentrations compared to the control (-53% and -65%, respectively) and ferulic acid (-47% and -60%, respectively) diets. Hamsters fed the control and ferulic acid diets had significantly higher plasma vitamin E concentrations compared to the RBO (201% and 161%, respectively) and oryzanol (548% and 462%, respectively) diets; the ferulic acid and oryzanol diets had significantly lower plasma lipid hydroperoxide levels than the control (-57% and -46%, respectively) diet. The oryzanol-fed hamsters excreted significantly more coprostenol and cholesterol in their feces than the ferulic acid (127% and 120%, respectively) diet. The control diet had significantly greater aortic TC and FC accumulation compared to the RBO (115% and 89%, respectively), ferulic acid (48% and 58%, respectively) and the oryzanol (74% and 70%, respectively) diets. However, only the RBO and oryzanol diets had significantly lower aortic cholesterol ester accumulation compared to the control (-73% and -46%, respectively) diet. The present study suggests that at equal dietary levels, oryzanol has a greater effect on lowering plasma non-HDL-C levels and raising plasma HDL-C than ferulic acid, possibly through a greater extent to increase fecal excretion of cholesterol and its metabolites. However, ferulic acid may have a greater antioxidant capacity via its ability to maintain serum vitamin E levels compared to RBO and oryzanol. Thus, both oryzanol and ferulic acid may exert similar antiatherogenic properties, but through different mechanisms. PMID:16713234

  6. P Limitation and Microbial Biogeochemistry in Acidic Forest Soils of the Northeastern United States

    Smemo, K. A.; Deforest, J. L.; Burke, D. J.; Elliot, H. L.; Kluber, L. A.; Carrino-Kyker, S. R.

    2010-12-01

    In forest ecosystems with acidic soils, such as many hardwood forests of the Northeastern United States, net primary productivity should be limited by phosphorus (P) because P is biologically less available at pH temperate forests that have naturally acidic soil or are exposed to chronic acid deposition; such findings are contrary to biogeochemical expectations. We hypothesize that many eastern forests possess an underlying P limitation not realized at the ecosystem level. Instead, shifts in the composition, structure and function of soil microbial communities compensate by acquiring more P from organic sources and P limitation is therefore not manifested at the aboveground (plant) level. To test this hypothesis, we manipulated soil pH and P availability in 72 20 x 40 m mature hardwood forest plots across northeastern (glaciated) and southeastern (unglaciated) Ohio beginning in late summer 2009. Ten months after treatment initiation, soil pH has increased from 4.5 to 5.5 and soil P has increased from 3 to ~25 mg P/kg soil on glaciated soils and from 0.5 to ~5 mg P/kg soil on unglaciated soils. To quantify treatment responses, we measured the activity of soil extracellular enzymes associated with liberation of P, N, and C from organic matter, as well as pools of N and N cycling processes. We saw no significant effects of our treatments on pools of available ammonium or nitrate, nor did we see effects on net N mineralization and net nitrification rates. However, glaciated soils had significantly greater nitrate pools and higher N cycling rates than older unglaciated soils. Nitrogen and C cycling enzymes in treatment plots were not significantly different than control plots, but N-acetylglucosaminidase activity (N acquisition) was significantly greater in the unglaciated soils and β-glucosidase and cellobiosidase activities (C cycling) were greatest in the glaciated soils. In only the unglaciated soils was the activity of P acquisition enzymes (phosphomonoesterase

  7. Generation of transgenic wheat (Triticum aestivum L.) accumulating heterologous endo-xylanase or ferulic acid esterase in the endosperm

    Harholt, Jesper; Bach, Inga C; Lind-Bouquin, Solveig; Nunan, Kylie J.; Madrid, Susan M.; Brinch-Pedersen, Henrik; Holm, Preben B.; Scheller, Henrik V.

    2009-12-08

    Endo-xylanase (from Bacillus subtilis) or ferulic acid esterase (from Aspergillus niger) were expressed in wheat under the control of the endosperm specific 1DX5 glutenin promoter. Constructs both with and without the endoplasmic reticulum retention signal KDEL were used. Transgenic plants were recovered in all four cases but no qualitative differences could be observed whether KDEL was added or not. Endo-xylanase activity in transgenic grains was increased between two and three fold relative to wild type. The grains were shriveled and had a 25-33% decrease in mass. Extensive analysis of the cell walls showed a 10-15% increase in arabinose to xylose ratio, a 50% increase in the proportion of water extractable arabinoxylan, and a shift in the MW of the water extractable arabinoxylan from being mainly larger than 85 kD to being between 2 kD and 85 kD. Ferulic acid esterase expressing grains were also shriveled and the seed weight was decreased by 20-50%. No ferulic acid esterase activity could be detected in wild type grains whereas ferulic acid esterase activity was detected in transgenic lines. The grain cell walls had 15-40% increase in water unextractable arabinoxylan and a decrease in monomeric ferulic acid between 13 and 34%. In all the plants the observed changes are consistent with a plant response that serves to minimize the effect of the heterologously expressed enzymes by increasing arabinoxylan biosynthesis and cross-linking.

  8. Solar-thermal complex sample processing for nucleic acid based diagnostics in limited resource settings.

    Gumus, Abdurrahman; Ahsan, Syed; Dogan, Belgin; Jiang, Li; Snodgrass, Ryan; Gardner, Andrea; Lu, Zhengda; Simpson, Kenneth; Erickson, David

    2016-05-01

    The use of point-of-care (POC) devices in limited resource settings where access to commonly used infrastructure, such as water and electricity, can be restricted represents simultaneously one of the best application fits for POC systems as well as one of the most challenging places to deploy them. Of the many challenges involved in these systems, the preparation and processing of complex samples like stool, vomit, and biopsies are particularly difficult due to the high number and varied nature of mechanical and chemical interferents present in the sample. Previously we have demonstrated the ability to use solar-thermal energy to perform PCR based nucleic acid amplifications. In this work demonstrate how the technique, using similar infrastructure, can also be used to perform solar-thermal based sample processing system for extracting and isolating Vibrio Cholerae nucleic acids from fecal samples. The use of opto-thermal energy enables the use of sunlight to drive thermal lysing reactions in large volumes without the need for external electrical power. Using the system demonstrate the ability to reach a 95°C threshold in less than 5 minutes and maintain a stable sample temperature of +/- 2°C following the ramp up. The system is demonstrated to provide linear results between 10(4) and 10(8) CFU/mL when the released nucleic acids were quantified via traditional means. Additionally, we couple the sample processing unit with our previously demonstrated solar-thermal PCR and tablet based detection system to demonstrate very low power sample-in-answer-out detection. PMID:27231636

  9. Solar-thermal complex sample processing for nucleic acid based diagnostics in limited resource settings

    Gumus, Abdurrahman; Ahsan, Syed; Dogan, Belgin; Jiang, Li; Snodgrass, Ryan; Gardner, Andrea; Lu, Zhengda; Simpson, Kenneth; Erickson, David

    2016-01-01

    The use of point-of-care (POC) devices in limited resource settings where access to commonly used infrastructure, such as water and electricity, can be restricted represents simultaneously one of the best application fits for POC systems as well as one of the most challenging places to deploy them. Of the many challenges involved in these systems, the preparation and processing of complex samples like stool, vomit, and biopsies are particularly difficult due to the high number and varied nature of mechanical and chemical interferents present in the sample. Previously we have demonstrated the ability to use solar-thermal energy to perform PCR based nucleic acid amplifications. In this work demonstrate how the technique, using similar infrastructure, can also be used to perform solar-thermal based sample processing system for extracting and isolating Vibrio Cholerae nucleic acids from fecal samples. The use of opto-thermal energy enables the use of sunlight to drive thermal lysing reactions in large volumes without the need for external electrical power. Using the system demonstrate the ability to reach a 95°C threshold in less than 5 minutes and maintain a stable sample temperature of +/− 2°C following the ramp up. The system is demonstrated to provide linear results between 104 and 108 CFU/mL when the released nucleic acids were quantified via traditional means. Additionally, we couple the sample processing unit with our previously demonstrated solar-thermal PCR and tablet based detection system to demonstrate very low power sample-in-answer-out detection. PMID:27231636

  10. Cd and Ni transport and accumulation in the halophyte Sesuvium portulacastrum: implication of organic acids in these processes

    Mnasri, Mejda; Ghabriche, Rim; Fourati, Emna; Zaier, Hanen; Sabally, Kebba; Barrington, Suzelle; Lutts, Stanley; Abdelly, Chedly; Ghnaya, Tahar

    2015-01-01

    The implication of organic acids in Cd and Ni translocation was studied in the halophyte species Sesuvium portulacastrum. Citric, fumaric, malic, and ascorbic acids were separated and quantified by HPLC technique in shoots, roots and xylem saps of plants grown on nutrient solutions added with 50 μM Cd, 100 μM Ni and the combination of 50 μM Cd + 100 μM Ni. Results showed that Cd had no significant impact on biomass production while Ni and the combination of both metals drastically affected pl...

  11. Cd and Ni transport and accumulation in the halophyte Sesuvium portulacastrum: implication of organic acids in these processes

    Tahar eGhnaya

    2015-01-01

    The implication of organic acids in Cd and Ni translocation was studied in the halophyte species Sesuvium portulacastrum. Citric, fumaric, malic and ascorbic acids were separated and quantified by HPLC technique in shoots, roots and xylem saps of plants grown on nutrient solutions added with 50 µM Cd, 100 µM Ni and the combination of 50 µM Cd + 100 µM Ni. Results showed that Cd had no significant impact on biomass production while Ni and the combination of both metals drastically affected pla...

  12. Impact of mixed low-molecular-weight organic acids on uranium accumulation and distribution in a variant of mustard (Brassica juncea var. tumida)

    The impact of a mixture of low-molecular-weight organic acids (LMWOAs) composed of CA/MA/OA/LA with a molar ratio of 2.5:2.31:1.15:0.044 on uranium (U) accumulation and distribution in mustard (Brassica juncea var. tumida) was studied in this paper in order to understand the mechanism of rhizosphere-exudation assisted phytoremediation by hydroponic and pot culture experiments. The impact of the mixture of LWMOAs (Mix) on U accumulation showed that in hydroponic conditions Mix could enhance U translocation from root-to-shoot in mustard, but inhibit U uptake in root. In pot experiments, Mix enhanced both root and shoot U accumulation in mustard. The time-dependent kinetics of U uptake in mustard on Mix treatment showed that U content in plant shoots and roots increased with time increasing, and the steady state conditions were obtained at the 8th and 5th day with the U content of 1,528 and 2,300 mg/kg, respectively. Transmission electron microscope and energy dispersive X-ray spectrometry analysis for mustard roots showed that U was mainly observed on cell membrane of mustard roots on Mix treatment. This study would provide new insights for the mixture of LWMOAs-assisted phytoremediation of U-contaminated soil. (author)

  13. Generation of transgenic wheat (Triticum aestivum L.) accumulating heterologous endo-xylanase or ferulic acid esterase in the endosperm

    Harholt, Jesper; Bach, Inga Christensen; Lind Bouquin, Solveig; Nunan, Kylie J.; Madrid, Susan M.; Brinch-Pedersen, Henrik; Holm, Preben Bach; Scheller, Henrik Vibe

    2010-01-01

    Endo-xylanase (from Bacillus subtilis) or ferulic acid esterase (from Aspergillus niger) were expressed in wheat under the control of the endosperm-specific 1DX5 glutenin promoter. Constructs both with and without the endoplasmic reticulum retention signal (Lys-Asp-Glu-Leu) KDEL were used. Transg...

  14. Accumulation of Rare Earth Elements in Spinach and Soil under Condition of Using REE and Acid Rain Stress

    严重玲; 洪业汤; 林鹏; 王世杰; 李心清; 梁洁

    2002-01-01

    The content and distribution characteristics of REE in spinach and soil under using REE and acid rain stress were studied by pot experiments. The results show that the content of REE is 0.527~0.696 (μgg-1) in the above-ground portion of spinach, 2.668~3.003 (μg*g-1) in the under-ground portion of spinach and 229.09~250.30 (μg*g-1) in the soil. With the acidity of acid rain increasing, the leaching of REE in plants and soil is strengthened and the amount of REE reduces with decreasing of pH value. After REE are used, though plants show the selective absorption to Ce group elements (especially spraying on leaves), regardless under acid rain stress or using REE or not, the distribution model of REE in the above-ground and under-ground portion of plants is basically the same with the control. Plants also follow the Oddo-Harkins rule of the REE of distribution abundance, light rare earth elements is enriched, the minus of Eu is abnormal and admeasure of Ce is a rich model. The results show that REE in plants mainly come from soil and are affected by it.

  15. Biofiltration of fishpond effluents and accumulation of N-compounds (phycobiliproteins and mycosporine-like amino acids) versus C-compounds (polysaccharides) in Hydropuntia cornea (Rhodophyta)

    The biofiltration capacity, biomass-yield and accumulation of N- and C-compounds of Hydropuntia cornea were analyzed. Algae were grown in different conditions for 28 d: outdoor and indoor, with or without fishpond effluents. N-uptake efficiency of these effluents was higher than 95% after 7 d both outdoors and indoors. N-enriched conditions reduced the extent of photoinhibition and increased the maximal quantum yield in H. cornea. The biomass-yield was higher in outdoor grown-algae after 7 d and decreased independently of the treatment after 28 d. N, acid polysaccharide (AP) and mycosporine-like amino acid (MAA)-yields decreased throughout the experiment in all conditions. The highest MAA-yield was observed in fishpond effluent outdoor-grown algae, indicating a positive effect of increased radiation on MAA accumulation. However, APs were higher under N-depleted conditions. The use of MAAs as UV-screening and antioxidants, and the use of AP as immunostimulants are discussed.

  16. Accumulation, selection and covariation of amino acids in sieve tube sap of tansy (Tanacetum vulgare) and castor bean (Ricinus communis): evidence for the function of a basic amino acid transporter and the absence of a γ-amino butyric acid transporter.

    Bauer, Susanne N; Nowak, Heike; Keller, Frank; Kallarackal, Jose; Hajirezaei, Mohamad-Reza; Komor, Ewald

    2014-09-01

    Sieve tube sap was obtained from Tanacetum by aphid stylectomy and from Ricinus after apical bud decapitation. The amino acids in sieve tube sap were analyzed and compared with those from leaves. Arginine and lysine accumulated in the sieve tube sap of Tanacetum more than 10-fold compared to the leaf extracts and they were, together with asparagine and serine, preferably selected into the sieve tube sap, whereas glycine, methionine/tryptophan and γ-amino butyric acid were partially or completely excluded. The two basic amino acids also showed a close covariation in sieve tube sap. The acidic amino acids also grouped together, but antagonistic to the other amino acids. The accumulation ratios between sieve tube sap and leaf extracts were smaller in Ricinus than in Tanacetum. Arginine, histidine, lysine and glutamine were enriched and preferentially loaded into the phloem, together with isoleucine and valine. In contrast, glycine and methionine/tryptophan were partially and γ-amino butyric acid almost completely excluded from sieve tube sap. The covariation analysis grouped arginine together with several neutral amino acids. The acidic amino acids were loaded under competition with neutral amino acids. It is concluded from comparison with the substrate specificities of already characterized plant amino acid transporters, that an AtCAT1-like transporter functions in phloem loading of basic amino acids, whereas a transporter like AtGAT1 is absent in phloem. Although Tanacetum and Ricinus have different minor vein architecture, their phloem loading specificities for amino acids are relatively similar. PMID:24446756

  17. Excessive ammonia inhibited transcription of MsU2 gene and furthermore affected accumulation distribution of allantoin and amino acids in alfalfa Medicago sativa

    WANG Li; JIANG Lin-lin; Nomura Mika; Tajima Shigeyuki; CHENG Xian-guo

    2015-01-01

    In legume plants, uricase gene (Nodulin-35) plays a positive role in metabolism of ureide and amide compounds in symbiotic nitrogen-ifxing in the nodules. In this study, a pot experiment was performed to examine the effects of ammonium application on the transcription of MsU2 gene and distribution of major nitrogen compounds in alfalfa Medicago sativa. Data showed that alfalfa plant has a signiifcant difference in contents of nitrogen compounds in xylem saps compared with soybean plant, and belongs to typical amide type legume plants with little ureide accumulation, and the accumulation of asparagines and ureide in the tissues of alfalfa is mainly gathered in the nodules. Northern blotting showed that excessive ammonium signiifcantly inhibited the transcription of MsU2 gene in the nodules and roots, and mRNA accumulation of MsU2 gene in the plants exposed to excessive ammonium decreased gradual y with culture time extension, indicating that application of ammonium signiifcantly inhibited the transcription of MsU2 gene in the alfalfa plants. Although the application of exces-sive ammonium increased the contents of amino acids in various tissues of alfalfa, the accumulation of al antoin relfecting the strength of uricase activity is remarkably reduced in the xylem saps, stems and nodules when alfalfa plants exposed to excessive ammonium, suggesting that application of excessive ammonium generated a negative effect on symbiosis ifxing-nitrogen system due to inhibition of ammonium ion on uricase activity in the nodules of alfalfa. This result seems to imply that application of excessive ammonium in legume plants should not be proposed to avoid affecting the ability of ifxing nitrogen in the nodules of legume plants, and reasonable dose of ammonium should be recommended to effectively utilize the ifxed N from atmosphere in legume plant production.

  18. Pattern of accumulation of inorganic elements in sunflower (helianthus annuus l.) plants subjected to salt stress and exogenous application of 5-aminolevulinic acid

    Influence of a potential plant growth regulator, 5-aminolevulinic acid (5-ALA) on the pattern of accumulation of some key inorganic elements in salt-stressed sunflower plants was observed under greenhouse conditions. Two cultivars of sunflower viz., Hysun-33 and S-278 were grown under non-saline and saline (150 mM NaCl) regimes in sand culture. After two weeks of salt treatment, all plants were subjected to four (0 (no spray), 20, 50 and 80 mg L/sup -1/) levels of 5-ALA as a foliar spray for 14 days. Shoot fresh and dry matter of both sunflower cultivars was markedly reduced due to salt stress. Of different inorganic ions, Na/sup +/ and Cl/sup -/ in leaf, stem and root tissues increased markedly while, K/sup +/, and Ca/sup 2+/ in all these tissues reduced under the saline regime. However, salt stress did not alter the leaf, stem or root P as well as root K/sup +/ /Na//sup +/ ratio. Foliar-applied ALA improved growth under normal (non-saline) and saline conditions, and 20 and 80 mg L/sup -1/ levels of 5-ALA were relatively more effective than the other levels used in this study. Of nutrient accumulation, 5-ALA altered only root Na/sup +/ and K/sup +/ and root K/sup +//Na/sup +/ ratio e.g., root Na/sup +/ was lower at 50 mg L/sup -1/, while root K/sup +/and K/sup +//Na/sup +/ ratio were higher at 80 mg L/sup -1/. In contrast, accumulation of all other ions in plant organs remained unaffected. Overall, foliar-applied 5-ALA did not alter the accumulation of different nutrients in different plant parts except root Na/sup +/, K/sup +/ and K/sup +//Na/sup +/ ratio in both sunflower cultivars. (author)

  19. Regulation of amino-acid metabolism controls flux to lipid accumulation in Yarrowia lipolytica

    Kerkhoven, Eduard J.; Pomraning, Kyle R.; Baker, Scott E.; Nielsen, Jens

    2016-01-01

    Yarrowia lipolytica is a promising microbial cell factory for the production of lipids to be used as fuels and chemicals, but there are few studies on regulation of its metabolism. Here we performed the first integrated data analysis of Y. lipolytica grown in carbon and nitrogen limited chemostat...... is similar to the overflow metabolism observed in many other microorganisms, e.g. ethanol production by Sacchromyces cerevisiae at nitrogen limitation....

  20. Foliar abscisic acid-to-ethylene accumulation and response regulate shoot growth sensitivity to mild drought in wheat

    Valluru, Ravi; Davies, William John; Reynolds, Matthew; Dodd, Ian Charles

    2016-01-01

    Although, plant hormones play an important role in adjusting growth in response to environmental perturbation, the relative contributions of abscisic acid (ABA) and ethylene remain elusive. Using six spring wheat genotypes differing for stress tolerance, we show that young seedlings of the drought-tolerant (DT) group maintained or increased shoot dry weight (SDW) while the drought-susceptible (DS) group decreased SDW in response to mild drought. Both the DT and DS groups increased endogenous ...

  1. Foliar abscisic acid-to-ethylene accumulation and response regulate shoot growth sensitivity to mild drought in wheat

    Ravi eValluru; William J eDavies; Matthew P eReynolds; Ian C eDodd

    2016-01-01

    Although plant hormones play an important role in adjusting growth in response to environmental perturbation, the relative contributions of abscisic acid (ABA) and ethylene remain elusive. Using six spring wheat genotypes differing for stress tolerance, we show that young seedlings of the drought-tolerant (DT) group maintained or increased shoot dry weight (SDW) while the drought-susceptible (DS) group decreased SDW in response to mild drought. Both the DT and DS groups increased endogenous A...

  2. Novel Inhibitory Effects of Glycyrrhizic Acid on the Accumulation of Advanced Glycation End Product and Its Receptor Expression

    Cheng, Hong Sheng; Kong, Joana Magdelene Xiao Fang; Ng, Athena Xin Hui; Chan, Weng Keong; Ton, So Ha; Abdul Kadir, Khalid

    2014-01-01

    Abstract Beneficial effects of glycyrrhizic acid (GA), a bioactive extract of licorice root, in the prevention of metabolic syndrome have been consistently reported while advanced glycation end products (AGE) and receptor for advanced glycation end product (RAGE) are the leading factors in the development of diabetes mellitus. The aim of this study was to investigate the effects of GA on the AGE-RAGE axis using high-fat/high-sucrose (HF/HS) diet-induced metabolic syndrome rat models. Twenty f...

  3. Oostatic peptides containing d-amino acids: synthesis, oostatic activity, degradation, accumulation in ovaries and NMR study

    Hlaváček, Jan; Tykva, Richard; Holík, Josef; Bennettová, Blanka; Buděšínský, Miloš; Vlasáková, Věra; Černý, Bohuslav; Slaninová, Jiřina

    2012-01-01

    Roč. 42, č. 5 (2012), s. 1715-1725. ISSN 0939-4451 R&D Projects: GA ČR GA203/06/1272 Institutional research plan: CEZ:AV0Z40550506; CEZ:AV0Z50380511; CEZ:AV0Z50070508 Keywords : D-amino acids * oostatic peptide synthesis * H-3 labeling * oostatic activity in Neobellieria bullata * H-3 incorporation * Peptide degradation * NMR study Subject RIV: CC - Organic Chemistry Impact factor: 3.914, year: 2012

  4. Cardiomyocyte Triglyceride Accumulation and Reduced Ventricular Function in Mice with Obesity Reflect Increased Long Chain Fatty Acid Uptake and De Novo Fatty Acid Synthesis

    Fengxia Ge

    2012-01-01

    Full Text Available A nonarteriosclerotic cardiomyopathy is increasingly seen in obese patients. Seeking a rodent model, we studied cardiac histology, function, cardiomyocyte fatty acid uptake, and transporter gene expression in male C57BL/6J control mice and three obesity groups: similar mice fed a high-fat diet (HFD and db/db and ob/ob mice. At sacrifice, all obesity groups had increased body and heart weights and fatty livers. By echocardiography, ejection fraction (EF and fractional shortening (FS of left ventricular diameter during systole were significantly reduced. The Vmax for saturable fatty acid uptake was increased and significantly correlated with cardiac triglycerides and insulin concentrations. Vmax also correlated with expression of genes for the cardiac fatty acid transporters Cd36 and Slc27a1. Genes for de novo fatty acid synthesis (Fasn, Scd1 were also upregulated. Ten oxidative phosphorylation pathway genes were downregulated, suggesting that a decrease in cardiomyocyte ATP synthesis might explain the decreased contractile function in obese hearts.

  5. Propensity to metal accumulation and oxidative stress responses of two benthic species (Cerastoderma edule and Nephtys hombergii): are tolerance processes limiting their responsiveness?

    Marques, Ana; Piló, David; Araújo, Olinda; Pereira, Fábio; Guilherme, Sofia; Carvalho, Susana; Santos, Maria Ana; Pacheco, Mário; Pereira, Patrícia

    2016-05-01

    The chronic exposure of benthic organisms to metals in sediments can lead to the development of tolerance mechanisms, thus diminishing their responsiveness. This study aims to evaluate the accumulation profiles of V, Cr, Co, Ni, As, Cd, Pb and Hg and antioxidant system responses of two benthic organisms (Cerastoderma edule, Bivalvia; Nephtys hombergii, Polychaeta). This approach will provide clarifications about the ability of each species to signalise metal contamination. Organisms of both species were collected at the Tagus estuary, in two sites with distinct contamination degrees (ALC, slightly contaminated; BAR, highly contaminated). Accordingly, C. edule accumulated higher concentrations of As, Pb and Hg at BAR compared to ALC. However, antioxidant responses of C. edule were almost unaltered at BAR and no peroxidative damage occurred, suggesting adjustment mechanisms to the presence of metals. In contrast, N. hombergii showed a minor propensity to metal accumulation, only signalising spatial differences for As and Pb and accumulating lower concentrations of metals than C. edule. The differences in metal accumulation observed between species might be due to their distinctive foraging behaviour and/or the ability of N. hombergii to minimise the metal uptake. Despite that, the accumulation of As and Pb was on the basis of the polychaete antioxidant defences inhibition at BAR, including CAT, SOD, GR and GPx. The integrated biomarker response index (IBRv2) confirmed that N. hombergii was more affected by metal exposure than C. edule. In the light of current findings, in field-based studies, the information of C. edule as a bioindicator should be complemented by that provided by another benthic species, since tolerance mechanisms to metals can hinder a correct diagnosis of sediment contamination and of the system's health. Overall, the present study contributed to improve the lack of fundamental knowledge of two widespread and common estuarine species, providing

  6. Propensity to metal accumulation and oxidative stress responses of two benthic species (Cerastoderma edule and Nephtys hombergii): are tolerance processes limiting their responsiveness?

    Marques, Ana

    2016-02-24

    The chronic exposure of benthic organisms to metals in sediments can lead to the development of tolerance mechanisms, thus diminishing their responsiveness. This study aims to evaluate the accumulation profiles of V, Cr, Co, Ni, As, Cd, Pb and Hg and antioxidant system responses of two benthic organisms (Cerastoderma edule, Bivalvia; Nephtys hombergii, Polychaeta). This approach will provide clarifications about the ability of each species to signalise metal contamination. Organisms of both species were collected at the Tagus estuary, in two sites with distinct contamination degrees (ALC, slightly contaminated; BAR, highly contaminated). Accordingly, C. edule accumulated higher concentrations of As, Pb and Hg at BAR compared to ALC. However, antioxidant responses of C. edule were almost unaltered at BAR and no peroxidative damage occurred, suggesting adjustment mechanisms to the presence of metals. In contrast, N. hombergii showed a minor propensity to metal accumulation, only signalising spatial differences for As and Pb and accumulating lower concentrations of metals than C. edule. The differences in metal accumulation observed between species might be due to their distinctive foraging behaviour and/or the ability of N. hombergii to minimise the metal uptake. Despite that, the accumulation of As and Pb was on the basis of the polychaete antioxidant defences inhibition at BAR, including CAT, SOD, GR and GPx. The integrated biomarker response index (IBRv2) confirmed that N. hombergii was more affected by metal exposure than C. edule. In the light of current findings, in field-based studies, the information of C. edule as a bioindicator should be complemented by that provided by another benthic species, since tolerance mechanisms to metals can hinder a correct diagnosis of sediment contamination and of the system’s health. Overall, the present study contributed to improve the lack of fundamental knowledge of two widespread and common estuarine species, providing

  7. Survival of mycobacteria depends on proteasome-mediated amino acid recycling under nutrient limitation

    Elharar, Yifat; Roth, Ziv; Hermelin, Inna; Moon, Alexandra; Peretz, Gabriella; Shenkerman, Yael; Vishkautzan, Marina; Khalaila, Isam; Gur, Eyal

    2014-01-01

    Intracellular protein degradation is an essential process in all life domains. While in all eukaryotes regulated protein degradation involves ubiquitin tagging and the 26S-proteasome, bacterial prokaryotic ubiquitin-like protein (Pup) tagging and proteasomes are conserved only in species belonging to the phyla Actinobacteria and Nitrospira. In Mycobacterium tuberculosis, the Pup-proteasome system (PPS) is important for virulence, yet its physiological role in non-pathogenic species has remained an enigma. We now report, using Mycobacterium smegmatis as a model organism, that the PPS is essential for survival under starvation. Upon nitrogen limitation, PPS activity is induced, leading to accelerated tagging and degradation of many cytoplasmic proteins. We suggest a model in which the PPS functions to recycle amino acids under nitrogen starvation, thereby enabling the cell to maintain basal metabolic activities. We also find that the PPS auto-regulates its own activity via pupylation and degradation of its components in a manner that promotes the oscillatory expression of PPS components. As such, the destructive activity of the PPS is carefully balanced to maintain cellular functions during starvation. PMID:24986881

  8. Phase transformations of high-purity PbI2 nanoparticles synthesized from lead-acid accumulator anodes

    Malevu, T. D.; Ocaya, R. O.; Tshabalala, K. G.

    2016-09-01

    High-purity hexagonal lead iodide nanoparticles have been synthesized from a depleted sealed lead acid battery anode. The synthesized product was found to consist of the rare 6R polytype form of PbI2 that is thought to have good potential in photovoltaic applications. We investigate the effects of annealing time and post-melting temperature on the structure and optical properties using 1.5418 Å CuKα radiation. Photoluminescence measurements were done under 150 W/221 nm wavelength xenon excitation. Phase transformation was observed through XRD peaks when annealing time increased from 0.5-5 h. The nanoparticle grain size and inter-planar distance appeared to be independent of annealing time. PL measurements show three broad peaks in a range of 400 nm to 700 nm that are attributed to excitonic, donor-acceptor pair and luminescence bands from the deep levels.

  9. Silencing of ABCC13 transporter in wheat reveals its involvement in grain development, phytic acid accumulation and lateral root formation.

    Bhati, Kaushal Kumar; Alok, Anshu; Kumar, Anil; Kaur, Jagdeep; Tiwari, Siddharth; Pandey, Ajay Kumar

    2016-07-01

    Low phytic acid is a trait desired in cereal crops and can be achieved by manipulating the genes involved either in its biosynthesis or its transport in the vacuoles. Previously, we have demonstrated that the wheat TaABCC13 protein is a functional transporter, primarily involved in heavy metal tolerance, and a probable candidate gene to achieve low phytate wheat. In the current study, RNA silencing was used to knockdown the expression of TaABCC13 in order to evaluate its functional importance in wheat. Transgenic plants with significantly reduced TaABCC13 transcripts in either seeds or roots were selected for further studies. Homozygous RNAi lines K1B4 and K4G7 exhibited 34-22% reduction of the phytic acid content in the mature grains (T4 seeds). These transgenic lines were defective for spike development, as characterized by reduced grain filling and numbers of spikelets. The seeds of transgenic wheat had delayed germination, but the viability of the seedlings was unaffected. Interestingly, early emergence of lateral roots was observed in TaABCC13-silenced lines as compared to non-transgenic lines. In addition, these lines also had defects in metal uptake and development of lateral roots in the presence of cadmium stress. Our results suggest roles of TaABCC13 in lateral root initiation and enhanced sensitivity towards heavy metals. Taken together, these data demonstrate that wheat ABCC13 is functionally important for grain development and plays an important role during detoxification of heavy metals. PMID:27342224

  10. Effect of surfactant on hydrolysis products accumulation and short-chain fatty acids (SCFA) production during mesophilic and thermophilic fermentation of waste activated sludge: kinetic studies.

    Zhang, Peng; Chen, Yinguang; Zhou, Qi

    2010-09-01

    In the presence of surfactant sodium dodecylbenzene sulfonate (SDBS) the hydrolysis products accumulation and the short-chain fatty acids (SCFA) production during waste activated sludge fermentation under mesophilic and thermophilic conditions was compared with that at room temperature. In order to understand the mechanism of significant amounts of mesophilic and thermophilic hydrolysis products and SCFA observed in the presence of surfactant, the kinetic models at different SDBS dosages were developed. It was found that SDBS increased the mesophilic and thermophilic hydrolysis rate significantly, and the maximum specific utilization of hydrolysis products increased at low SDBS and decreased at high one. However, the observed maximum specific utilization of SCFA decreased seriously with SDBS increase. In the presence of SDBS the decay rate of acidogenic bacteria not only was lower than that in the absence of SDBS but decreased with the increase of SDBS under either mesophilic or thermophilic conditions. PMID:20409704

  11. Impact of Precooling and Controlled-Atmosphere Storage on γ-Aminobutyric Acid (GABA) Accumulation in Longan (Dimocarpus longan Lour.) Fruit.

    Zhou, Molin; Ndeurumio, Kessy H; Zhao, Lei; Hu, Zhuoyan

    2016-08-24

    Longan (Dimocarpus longan Lour.) fruit cultivars 'Chuliang' and 'Shixia' were analyzed for γ-aminobutyric acid (GABA) accumulation after precooling and in controlled-atmosphere storage. Fruit were exposed to 5% O2 plus 3%, 5%, or 10% CO2 at 4 °C, and GABA and associated enzymes, aril firmness, and pericarp color were measured. Aril softening and pericarp browning were delayed by 5% CO2 + 5% O2. GABA concentrations and glutamate decarboxylase (GAD; EC 4.1.1.15) activities declined during storage at the higher-CO2 treatments. However, GABA aminotransferase (GABA-T; EC 2.6.1.19) activities in elevated CO2-treated fruit fluctuated during storage. GABA concentrations increased after precooling treatments. GAD activity and GABA-T activity were different between cultivars after precooling. GABA concentrations in fruit increased after 3 days of 10% CO2 + 5% O2 treatment and then declined as storage time increased. GABA accumulation was associated with stimulation of GAD activity rather than inhibition of GABA-T activity. PMID:27412947

  12. Salicylic acid treatment reduces the rot of postharvest citrus fruit by inducing the accumulation of H2O2, primary metabolites and lipophilic polymethoxylated flavones.

    Zhu, Feng; Chen, Jiajing; Xiao, Xue; Zhang, Mingfei; Yun, Ze; Zeng, Yunliu; Xu, Juan; Cheng, Yunjiang; Deng, Xiuxin

    2016-09-15

    To comprehensively analyze the effects of salicylic acid (SA) on the storability of Satsuma mandarin (Citrus unshiu), fruits were treated with 2mM SA. The disease incidence of control/SA-treated fruit at 50d and 120d after treatment was 23.3%/10% and 67.3%/23.3%, respectively, suggesting that SA treatment can significantly reduce the rot rate of postharvest citrus fruit. Fruit quality assays revealed that the treatment can maintain fruit firmness without affecting the inner quality. Furthermore, the contents of H2O2 and some defense-related metabolites, such as ornithine and threonine, in citrus pericarp, were significantly increased by SA treatment. Moreover, it was lipophilic polymethoxylated flavones, rather than flavanone glycosides, that accumulated in SA-treated fruits and these can directly inhibit pathogen development. These results suggest that the effects of SA on postharvest citrus fruit may be attributed to the accumulation of H2O2 and defense-related metabolites. PMID:27080881

  13. Low Temperature-Induced 30 (LTI30 positively regulates drought stress resistance in Arabidopsis: effect on abscisic acid sensitivity and hydrogen peroxide accumulation

    Haitao eShi

    2015-10-01

    Full Text Available As a dehydrin belonging to group II late embryogenesis abundant protein (LEA family, Arabidopsis Low Temperature-Induced 30 (LTI30/XERO2 has been shown to be involved in plant freezing stress resistance. However, the other roles of AtLTI30 remain unknown. In this study, we found that the expression of AtLTI30 was largely induced by drought stress and abscisic acid (ABA treatments. Thereafter, AtLTI30 knockout mutants and overexpressing plants were isolated to investigate the possible involvement of AtLTI30 in ABA and drought stress responses. AtLTI30 knockout mutants were less sensitive to ABA-mediated seed germination, while AtLTI30 overexpressing plants were more sensitive to ABA compared with wild type (WT. Consistently, the AtLTI30 knockout mutants displayed decreased drought stress resistance, while the AtLTI30 overexpressing plants showed improved drought stress resistance compared with WT, as evidenced by a higher survival rate and lower leaf water loss than WT after drought stress. Moreover, manipulation of AtLTI30 expression positively regulated the activities of catalases (CATs and endogenous proline content, as a result, negatively regulated drought stress-triggered hydrogen peroxide (H2O2 accumulation. All these results indicate that AtLTI30 is a positive regulator of plant drought stress resistance, partially through the modulation of ABA sensitivity, H2O2 and proline accumulation.

  14. The effect of cis-jasmone, jasmonic acid and methyl jasmonate on accumulation of anthocyanins and proanthocyanidins in seedlings of common buckwheat (Fagopyrum esculentum Moench

    Marcin Horbowicz

    2011-04-01

    Full Text Available Effects of various jasmonates (methyl jasmonate, jasmonic acid, cis-jasmone on anthocyanins and procyanidins content of, as well as on growth of common buckwheat (Fagopyrum esculentum Moench seedlings were studied. The studied jasmonates were applied as solutions or vapors on four days seedlings, and the seedlings were grown during the next four days in day/night conditions (16/8 h. Afterwards anthocyanins and proanthocyanidins content, as well as elongation of primary roots and hypocotyls were measured. When applied as solutions cis-jasmone (JAS stimulated the anthocyanins accumulation, but when used as vapors had tendency to decrease its accumulation in buckwheat hypocotyls. Jasmonic acid (JA solutions slightly stimulated or had no effect on biosynthesis of anthocyanins in buckwheat hypocotyls, but used as vapors caused a decline of anthocyanins in buckwheat hypocotyls. Methyl jasmonate (MJ clearly inhibited biosynthesis of anthocyanins in hypocotyls of buckwheat seedlings. The studied jasmonates had no influence on anthocyanins level in cotyledons of buckwheat seedlings, except cis-jasmone, which at the lowest solution concentration slightly enhanced biosynthesis of the pigments. Treatment of buckwheat seedlings with solutions of all jasmonates (10-8 M, 10-6 M and 10-4 M had no influence on the growth of buckwheat hypocotyls. Contrary to that observation vapors of the growth regulators in concentrations 10-4 M, had a strong inhibitory effect on the growth of hypocotyls of buckwheat seedlings. Solutions of JA and MJ, as well as vapors of JA, MJ and JAS strongly inhibited the primary root growth of buckwheat seedlings, while JAS applied as solution had no such influence. MJ and JA caused much higher stimulation of proanthocyanidin biosynthesis in buckwheat hypocotyls than JAS.

  15. Effects of Ghrelin on Triglyceride Accumulation and Glucose Uptake in Primary Cultured Rat Myoblasts under Palmitic Acid-Induced High Fat Conditions

    Lingling Han

    2015-01-01

    Full Text Available This study aimed to study the effects of acylated ghrelin on glucose and triglyceride metabolism in rat myoblasts under palmitic acid- (PA- induced high fat conditions. Rat myoblasts were treated with 0, 10−11, 10−9, or 10−7 M acylated ghrelin and 0.3 mM PA for 12 h. Triglyceride accumulation was determined by Oil-Red-O staining and the glycerol phosphate dehydrogenase-peroxidase enzymatic method, and glucose uptake was determined by isotope tracer. The glucose transporter 4 (GLUT4, AMP-activated protein kinase (AMPK, acetyl-CoA carboxylase (ACC, and uncoupling protein 3 (UCP3 were assessed by RT-PCR and western blot. Compared to 0.3 mM PA, ghrelin at 10−9 and 10−7 M reduced triglyceride content (5.855 ± 0.352 versus 5.030 ± 0.129 and 4.158 ± 0.254 mM, P<0.05 and prevented PA-induced reduction of glucose uptake (1.717 ± 0.264 versus 2.233 ± 0.333 and 2.333 ± 0.273 10−2 pmol/g/min, P<0.05. The relative protein expression of p-AMPKα/AMPKα, UCP3, and p-ACC under 0.3 mM PA was significantly reduced compared to controls (all P<0.05, but those in the 10−9 and 10−7 M ghrelin groups were significantly protected from 0.3 mM PA (all P<0.05. In conclusion, acylated ghrelin reduced PA-induced triglyceride accumulation and prevented the PA-induced decrease in glucose uptake in rat myoblasts. These effects may involve fatty acid oxidation.

  16. Leptosphaeria maculans effector AvrLm4-7 affects salicylic acid (SA) and ethylene (ET) signalling and hydrogen peroxide (H2 O2 ) accumulation in Brassica napus.

    Nováková, Miroslava; Šašek, Vladimír; Trdá, Lucie; Krutinová, Hana; Mongin, Thomas; Valentová, Olga; Balesdent, Marie-HelEne; Rouxel, Thierry; Burketová, Lenka

    2016-08-01

    To achieve host colonization, successful pathogens need to overcome plant basal defences. For this, (hemi)biotrophic pathogens secrete effectors that interfere with a range of physiological processes of the host plant. AvrLm4-7 is one of the cloned effectors from the hemibiotrophic fungus Leptosphaeria maculans 'brassicaceae' infecting mainly oilseed rape (Brassica napus). Although its mode of action is still unknown, AvrLm4-7 is strongly involved in L. maculans virulence. Here, we investigated the effect of AvrLm4-7 on plant defence responses in a susceptible cultivar of B. napus. Using two isogenic L. maculans isolates differing in the presence of a functional AvrLm4-7 allele [absence ('a4a7') and presence ('A4A7') of the allele], the plant hormone concentrations, defence-related gene transcription and reactive oxygen species (ROS) accumulation were analysed in infected B. napus cotyledons. Various components of the plant immune system were affected. Infection with the 'A4A7' isolate caused suppression of salicylic acid- and ethylene-dependent signalling, the pathways regulating an effective defence against L. maculans infection. Furthermore, ROS accumulation was decreased in cotyledons infected with the 'A4A7' isolate. Treatment with an antioxidant agent, ascorbic acid, increased the aggressiveness of the 'a4a7' L. maculans isolate, but not that of the 'A4A7' isolate. Together, our results suggest that the increased aggressiveness of the 'A4A7' L. maculans isolate could be caused by defects in ROS-dependent defence and/or linked to suppressed SA and ET signalling. This is the first study to provide insights into the manipulation of B. napus defence responses by an effector of L. maculans. PMID:26575525

  17. High molecular weight hyaluronic acid limits astrocyte activation and scar formation after spinal cord injury

    Khaing, Zin Z.; Milman, Brian D.; Vanscoy, Jennifer E.; Seidlits, Stephanie K.; Grill, Raymond J.; Schmidt, Christine E.

    2011-08-01

    A major hurdle for regeneration after spinal cord injury (SCI) is the ability of axons to penetrate and grow through the scar tissue. After SCI, inflammatory cells, astrocytes and meningeal cells all play a role in developing the glial scar. In addition, degradation of native high molecular weight (MW) hyaluronic acid (HA), a component of the extracellular matrix, has been shown to induce activation and proliferation of astrocytes. However, it is not known if the degradation of native HA actually enhances glial scar formation. We hypothesize that the presence of high MW HA (HA with limited degradation) after SCI will decrease glial scarring. Here, we demonstrate that high MW HA decreases cell proliferation and reduces chondroitin sulfate proteoglycan (CSPG) production in cultured neonatal and adult astrocytes. In addition, stiffness-matched high MW HA hydrogels crosslinked to resist degradation were implanted in a rat model of spinal dorsal hemisection injury. The numbers of immune cells (macrophages and microglia) detected at the lesion site in animals with HA hydrogel implants were significantly reduced at acute time points (one, three and ten days post-injury). Lesioned animals with HA implants also exhibited significantly lower CSPG expression at ten days post-injury. At nine weeks post-injury, animals with HA hydrogel implants exhibited a significantly decreased astrocytic response, but did not have significantly altered CSPG expression. Combined, these data suggest that high MW HA, when stabilized against degradation, mitigates astrocyte activation in vitro and in vivo. The presence of HA implants was also associated with a significant decrease in CSPG deposition at ten days after SCI. Therefore, HA-based hydrogel systems hold great potential for minimizing undesired scarring as part of future repair strategies after SCI.

  18. Endogenous Synthesis of Amino Acids Limits Growth, Lactation, and Reproduction in Animals.

    Hou, Yongqing; Yao, Kang; Yin, Yulong; Wu, Guoyao

    2016-03-01

    Amino acids (AAs) are building blocks of protein. Eight AAs (Ala, Asn, Asp, Glu, Gln, Gly, Pro, and Ser) are formed by all animals, whereas de novo synthesis of Arg occurs in a species-specific manner in most mammals (e.g., humans, pigs, and rats). Synthesizable AAs were traditionally classified as nutritionally nonessential for animals, because they were thought to be formed in sufficient amounts. However, this assumption is not supported by evidence showing that 1) rats grow slowly when their diets do not contain Arg, Glu, or Gln despite adequate provision of all other proteinogenous AAs; 2) pigs cannot achieve maximum growth, lactation, or reproduction performance when fed corn- and soybean meal-based diets meeting National Research Council-recommended requirements of protein and AAs without supplemental Arg, Glu, Gln, Gly, or Pro; 3) chickens exhibit increases in lean tissue gain and feed efficiency when their diets are supplemented with Glu, Gln, Gly, and Pro; 4) lactating cows cannot obtain maximum milk protein production without a postruminal supply of Gln or Pro; 5) fish cannot achieve maximum growth when diets do not contain Gln or Pro; and 6) men fail to sustain spermatogenesis when fed an Arg-deficient diet. Quantitative analysis of nitrogen metabolism showed that AA synthesis in animals is constrained by both precursor availability and enzyme activity. Taken together, these findings support the conclusion that the endogenous synthesis of AAs limits growth, lactation, and reproduction in animals. This new knowledge can guide the optimization of human nutrition for improving health and well-being. PMID:26980816

  19. Similar PAH fate in anaerobic digesters inoculated with three microbial communities accumulating either volatile fatty acids or methane.

    Florence Braun

    Full Text Available Urban sludge produced on wastewater treatment plants are often contaminated by organic pollutants such as polycyclic aromatic hydrocarbons (PAH. Their removal under methanogenic conditions was already reported, but the factors influencing this removal remain unclear. Here, we determined the influence of microbial communities on PAH removal under controlled physico-chemical conditions. Twelve mesophilic anaerobic digesters were inoculated with three microbial communities extracted from ecosystems with contrasting pollution histories: a PAH contaminated soil, a PCB contaminated sediment and a low contaminated anaerobic sludge. These anaerobic digesters were operated during 100 days in continuous mode. A sterilised activated sludge, spiked with 13 PAH at concentrations usually encountered in full-scale wastewater treatment plants, was used as substrate. The dry matter and volatile solid degradation, the biogas production rate and composition, the volatile fatty acids (VFA production and the PAH removals were monitored. Bacterial and archaeal communities were compared in abundance (qPCR, in community structure (SSCP fingerprinting and in dominant microbial species (454-pyrosequencing. The bioreactors inoculated with the community extracted from low contaminated anaerobic sludge showed the greater methane production. The PAH removals ranged from 10% to 30%, respectively, for high and low molecular weight PAH, whatever the inoculums tested, and were highly correlated with the dry matter and volatile solid removals. The microbial community structure and diversity differed with the inoculum source; this difference was maintained after the 100 days of digestion. However, the PAH removal was not correlated to these diverse structures and diversities. We hence obtained three functional stable consortia with two contrasted metabolic activities, and three different pictures of microbial diversity, but similar PAH and matter removals. These results confirm

  20. Rapid Phosphatidic Acid Accumulation in Response to Low Temperature Stress in Arabidopsis is Generated through Diacylglycerol Kinase

    Steven A. Arisz

    2013-01-01

    Full Text Available Phosphatidic acid (PtdOH is emerging as an important signalling lipid in abiotic stress responses in plants. The effect of cold stress was monitored using 32P-labelled seedlings and leaf discs of Arabidopsis thaliana. Low, non-freezing temperatures were found to trigger a very rapid 32P-PtdOH increase, peaking within 2 and 5 min, respectively. In principle, PtdOH can be generated through three different pathways, i.e. i via de novo phospholipid biosynthesis (through acylation of lyso-PtdOH, ii via phospholipase D hydrolysis of structural phospholipids or iii via phosphorylation of diacylglycerol (DAG by DAG kinase (DGK. Using a differential 32P-labelling protocol and a PLD-transphosphatidylation assay, evidence is provided that the rapid 32P-PtdOH response was primarily generated through DGK. A simultaneous decrease in the levels of 32P-PtdInsP, correlating in time, temperature dependency and magnitude with the increase in 32P-PtdOH, suggested that a PtdInsP-hydrolyzing PLC generated the DAG in this reaction. Testing T-DNA insertion lines available for the seven DGK genes, revealed no clear changes in 32P-PtdOH responses, suggesting functional redundancy. Similarly, known cold-stress mutants were analyzed to investigate whether the PtdOH response acted downstream of the respective gene products. The hos1, los1 and fry1 mutants were found to exhibit normal PtdOH responses. Slight changes were found for ice1, snow1, and the overexpression line Super-ICE1, however, this was not cold-specific and likely due to pleiotropic effects. A tentative model illustrating direct cold effects on phospholipid metabolism is presented.

  1. Experimentally Testing the Hypothesis of a Limited Amino Acid Repertoire in Primitive Proteins

    Akanuma, S.; Nakajima, Y.; Yokobori, S.; Yamagishi, A.

    2013-11-01

    It has been argued that a fewer amino acids were used in primitive proteins and later the repertoire increased up to 20. To test this hypothesis experimentally, we restricted the amino acid usage of a reconstructed, ancestral protein to reduced sets.

  2. Intake of a Western diet containing cod instead of pork alters fatty acid composition in tissue phospholipids and attenuates obesity and hepatic lipid accumulation in mice.

    Liisberg, Ulrike; Fauske, Kristin Røen; Kuda, Ondrej; Fjære, Even; Myrmel, Lene Secher; Norberg, Nina; Frøyland, Livar; Graff, Ingvild Eide; Liaset, Bjørn; Kristiansen, Karsten; Kopecky, Jan; Madsen, Lise

    2016-07-01

    The content of the marine n-3 polyunsaturated fatty acids (PUFAs), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) is far lower in lean than in fatty seafood. Cod filets contain less than 2g fat per kg, whereof approximately 50% is EPA and DHA. However, a large fraction of these n-3 PUFAs is present in the phospholipid (PL) fraction and may have high bioavailability and capacity to change the endocannabinoid profile. Here we investigated whether exchanging meat from a lean terrestrial animal with cod in a background Western diet would alter the endocannabinoid tone in mice and thereby attenuate obesity development and hepatic lipid accumulation. Accordingly, we prepared iso-caloric diets with 15.1 energy (e) % protein, 39.1 e% fat and 45.8 e% carbohydrates using freeze-dried meat from cod filets or pork sirloins, and using a combination of soybean oil, corn oil, margarine, milk fat, and lard as the fat source. Compared with mice receiving diets containing pork, mice fed cod gained less adipose tissue mass and had a lower content of hepatic lipids. This was accompanied by a lower n-6 to n-3 ratio in liver PLs and in red blood cells (RBCs) in the mice. Furthermore, mice receiving the cod-containing diet had lower circulating levels of the two major endocannabinoids, N-arachidonoylethanolamine and 2-arachidonoylglycerol. Together, our data demonstrate that despite the relatively low content of n-3 PUFAs in cod fillets, the cod-containing diet could exert beneficial metabolic effects. PMID:27155918

  3. Involvement of sigmaS accumulation in repression of the flhDC operon in acidic phospholipid-deficient mutants of Escherichia coli.

    Uchiyama, Junji; Nobue, Yuka; Zhao, Hong; Matsuzaki, Hiroshi; Nagahama, Hideki; Matsuoka, Satoshi; Matsumoto, Kouji; Hara, Hiroshi

    2010-06-01

    Escherichia coli pgsA mutations, which cause acidic phospholipid deficiency, repress transcription of the flagellar master operon flhDC, and thus impair flagellar formation and motility. The molecular mechanism of the strong repression of flhDC transcription in the mutant cells, however, has not yet been clarified. In order to shed light on this mechanism we isolated genes which, when supplied in multicopy, suppress the repression of flhD, and found that three genes, gadW, metE and yeaB, were capable of suppression. Taking into account a previous report that gadW represses sigma(S) production, the level of sigma(S) in the pgsA3 mutant was examined. We found that pgsA3 cells had a high level of sigma(S) and that introduction of a gadW plasmid into pgsA3 cells did reduce the sigma(S) level. The pgsA3 cells exhibited a sharp increase in sigma(S) levels that can only be partially attributed to the slight increase in rpoS transcription; the largest part of the effect is due to a post-transcriptional accumulation of sigma(S). GadW in multicopy exerts its effect by post-transcriptionally downregulating sigma(S). YeaB and MetE in multicopy also exert their effect via sigma(S). Disruption of rpoS caused an increase of the flhD mRNA level, and induction from P(trc)-rpoS repressed the flhD mRNA level. The strong repression of flhD transcription in pgsA3 mutant cells is thus suggested to be caused by the accumulated sigma(S). PMID:20185506

  4. Comparison of trans-1-amino-3-[18 F]fluorocyclobutanecarboxylic acid (anti-[18 F]FACBC) accumulation in lymph node prostate cancer metastasis and lymphadenitis in rats

    Introduction: Trans-1-amino-3-[18 F]fluorocyclobutanecarboxylic acid (anti-[18 F]FACBC) is a positron emission tomography (PET) tracer used to visualize prostate cancer (PCa). In this study, we investigated the differences in anti-[18 F]FACBC accumulation between metastatic and inflamed lymph node (LN) lesions. Methods: A PCa LN metastasis (PLM) model was developed by inoculating a rat PCa cell line, MAT-Ly-Lu-B2, into popliteal LNs of Copenhagen rats. Acute lymphadenitis (AL) was induced by injecting concanavalin A (Con A) into the hind footpad, and chronic lymphadenitis (CL) was induced by daily injection of Con A into the tissues surrounding the popliteal LNs for 2 weeks. Main lesions of all animal models were established in lumbar and/or inguinal LNs. Biodistribution and dynamic PET imaging data were acquired after tracer injection. T2-weighted magnetic resonance (MR) images were registered with PET images. Results: In the biodistribution study, the uptake ratios of PLM-to-lymphadenitis in lesional lumbar and inguinal LNs were 0.97 − 1.57 and 1.47 − 2.08 at 15 and 60 min post-anti-[18 F]FACBC injection respectively. In PET imaging, the lesional lumbar LNs of CL and PLM, but not of AL, were visualized on anti-[18 F]FACBC-PET/MR fusion images without disturbance from radioactivity from urine, and the rank order of anti-[18 F]FACBC accumulation at 50 − 60 post-injection in lesional lumbar LNs was PLM > CL > AL. Conclusions: Anti-[18 F]FACBC accumulation in LNs with PLM was higher than that in inflamed LNs. Advances in knowledge: The study showed that although low but significant levels of anti-[18 F]FACBC uptake by chronic inflamed lesions might cause false-positives in anti-[18 F]FACBC-PET in some PCa patients, uptake of the tracer at acutely inflamed sites was minimal. Implications for patient care: The findings of this study suggest the potential of Anti-[18 F]FACBC for distinguishing between tumors and acute inflammation in clinical practice

  5. What makes ribosome-mediated transcriptional attenuation sensitive to amino Acid limitation?

    2005-06-01

    Full Text Available Ribosome-mediated transcriptional attenuation mechanisms are commonly used to control amino acid biosynthetic operons in bacteria. The mRNA leader of such an operon contains an open reading frame with "regulatory" codons, cognate to the amino acid that is synthesized by the enzymes encoded by the operon. When the amino acid is in short supply, translation of the regulatory codons is slow, which allows transcription to continue into the structural genes of the operon. When amino acid supply is in excess, translation of regulatory codons is rapid, which leads to termination of transcription. We use a discrete master equation approach to formulate a probabilistic model for the positioning of the RNA polymerase and the ribosome in the attenuator leader sequence. The model describes how the current rate of amino acid supply compared to the demand in protein synthesis (signal determines the expression of the amino acid biosynthetic operon (response. The focus of our analysis is on the sensitivity of operon expression to a change in the amino acid supply. We show that attenuation of transcription can be hyper-sensitive for two main reasons. The first is that its response depends on the outcome of a race between two multi-step mechanisms with synchronized starts: transcription of the leader of the operon, and translation of its regulatory codons. The relative change in the probability that transcription is aborted (attenuated can therefore be much larger than the relative change in the time it takes for the ribosome to read a regulatory codon. The second is that the general usage frequencies of codons of the type used in attenuation control are small. A small percentage decrease in the rate of supply of the controlled amino acid can therefore lead to a much larger percentage decrease in the rate of reading a regulatory codon. We show that high sensitivity further requires a particular choice of regulatory codon among several synonymous codons for the

  6. What makes ribosome-mediated transcriptional attenuation sensitive to amino acid limitation?

    Johan Elf

    2005-06-01

    Full Text Available Ribosome-mediated transcriptional attenuation mechanisms are commonly used to control amino acid biosynthetic operons in bacteria. The mRNA leader of such an operon contains an open reading frame with "regulatory" codons, cognate to the amino acid that is synthesized by the enzymes encoded by the operon. When the amino acid is in short supply, translation of the regulatory codons is slow, which allows transcription to continue into the structural genes of the operon. When amino acid supply is in excess, translation of regulatory codons is rapid, which leads to termination of transcription. We use a discrete master equation approach to formulate a probabilistic model for the positioning of the RNA polymerase and the ribosome in the attenuator leader sequence. The model describes how the current rate of amino acid supply compared to the demand in protein synthesis (signal determines the expression of the amino acid biosynthetic operon (response. The focus of our analysis is on the sensitivity of operon expression to a change in the amino acid supply. We show that attenuation of transcription can be hyper-sensitive for two main reasons. The first is that its response depends on the outcome of a race between two multi-step mechanisms with synchronized starts: transcription of the leader of the operon, and translation of its regulatory codons. The relative change in the probability that transcription is aborted (attenuated can therefore be much larger than the relative change in the time it takes for the ribosome to read a regulatory codon. The second is that the general usage frequencies of codons of the type used in attenuation control are small. A small percentage decrease in the rate of supply of the controlled amino acid can therefore lead to a much larger percentage decrease in the rate of reading a regulatory codon. We show that high sensitivity further requires a particular choice of regulatory codon among several synonymous codons for the

  7. What makes ribosome-mediated transcriptional attenuation sensitive to amino acid limitation?

    Elf, Johan; Ehrenberg, Måns

    2005-06-01

    Ribosome-mediated transcriptional attenuation mechanisms are commonly used to control amino acid biosynthetic operons in bacteria. The mRNA leader of such an operon contains an open reading frame with "regulatory" codons, cognate to the amino acid that is synthesized by the enzymes encoded by the operon. When the amino acid is in short supply, translation of the regulatory codons is slow, which allows transcription to continue into the structural genes of the operon. When amino acid supply is in excess, translation of regulatory codons is rapid, which leads to termination of transcription. We use a discrete master equation approach to formulate a probabilistic model for the positioning of the RNA polymerase and the ribosome in the attenuator leader sequence. The model describes how the current rate of amino acid supply compared to the demand in protein synthesis (signal) determines the expression of the amino acid biosynthetic operon (response). The focus of our analysis is on the sensitivity of operon expression to a change in the amino acid supply. We show that attenuation of transcription can be hyper-sensitive for two main reasons. The first is that its response depends on the outcome of a race between two multi-step mechanisms with synchronized starts: transcription of the leader of the operon, and translation of its regulatory codons. The relative change in the probability that transcription is aborted (attenuated) can therefore be much larger than the relative change in the time it takes for the ribosome to read a regulatory codon. The second is that the general usage frequencies of codons of the type used in attenuation control are small. A small percentage decrease in the rate of supply of the controlled amino acid can therefore lead to a much larger percentage decrease in the rate of reading a regulatory codon. We show that high sensitivity further requires a particular choice of regulatory codon among several synonymous codons for the same amino acid. We

  8. Optical limiting response of multi-walled carbon nanotube-phthalocyanine nanocomposite in solution and when in poly (acrylic acid)

    Sekhosana, Kutloano Edward; Nyokong, Tebello

    2016-08-01

    Bis{23-(3,4-di-yloxybenzoic acid)-(2(3), 9(10), 16(17), 23(24)-(hexakis-pyridin-3-yloxy phthalocyaninato)} dineodymium (III) acetate (3) is linked to amino-functionalized multi-walled carbon nanotubes (MWCNT) to form 3-MWCNT. Z-scan technique was employed to experimentally determine the nonlinear absorption coefficient from the open-aperture data. The limiting threshold values as low as 0.045 J cm-2 were found in solution. The conjugate (3-MWCNT) gave better optical limiting behavior than complex 3 alone.

  9. 籽用南瓜种子发育过程中脂肪酸积累模式%Accumulation pattern of fatty acids during pumpkin ( Cucurbita maxima Duch) seed development

    屈淑平; 常影; 秦俊芬; 邢伟; 崔崇士

    2011-01-01

    Accumulation pattern of fatty acids during seed development of seed pumpkin (Cucurbita maxima cv Yinhui 1) was investigated using GC -MS method. Results showed eight fatty acids in mature pumpkin seeds. They were oleic acid, linoleic acid, cetylic acid, stearic acid, arachic acid, myristic acid, palmitoleic acid and linolenic acid. The quantity of crude fat changed during seed development in Z curve. During accumulation, there were negative correlation between oleic acid (C18: 1) and linolenic acid (C18: 2), and positive correlation among other fatty acids.%以籽用南瓜品种银辉一号为材料对南瓜种子发育过程中脂肪酸的累积过程进行了分析.结果表明,成熟的南瓜种子中可检测到8种脂肪酸,按含量高低依次为:油酸、亚油酸、棕榈酸、硬脂酸、花生酸、豆蔻酸、棕榈油酸、亚麻酸.南瓜种子粗脂肪含量的积累模式呈现升-降-升的Z字型变化模式.在累积过程中除了C18∶1和C1∶2有负相关性外,其它脂肪酸相互之间显示了高度的正相关性.

  10. Biocontrol of Potato Common Scab is Associated with High Pseudomonas fluorescens LBUM223 Populations and Phenazine-1-Carboxylic Acid Biosynthetic Transcript Accumulation in the Potato Geocaulosphere.

    Arseneault, Tanya; Goyer, Claudia; Filion, Martin

    2016-09-01

    Pseudomonads are often used as biocontrol agents because they display a broad range of mechanisms to control diseases. Common scab of potato, caused by Streptomyces scabies, was previously reported to be controlled by Pseudomonas fluorescens LBUM223 through phenazine-1-carboxylic acid (PCA) production. In this study, we aimed at characterizing the population dynamics of LBUM223 and the expression of phzC, a key gene involved in the biosynthesis of PCA, in the rhizosphere and geocaulosphere of potato plants grown under controlled and field conditions. Results obtained from controlled experiments showed that soil populations of LBUM223 significantly declined over a 15-week period. However, at week 15, the presence of S. scabies in the geocaulosphere was associated with significantly higher populations of LBUM223 than when the pathogen was absent. It also led to the detection of significantly higher phzC gene transcript numbers. Under field conditions, soil populations of LBUM223 followed a similar decline in time when a single inoculation was applied in spring but remained stable when reinoculated biweekly, which also led to greater phzC gene transcripts accumulation. Taken together, our findings suggest that LBUM223 must colonize the potato geocaulosphere at high levels (10(7) bacteria/g of soil) in order to achieve biocontrol of common scab through increased PCA production. PMID:27088392

  11. Arachidonic acid alters tomato HMG expression and fruit growth and induces 3-hydroxy-3-methylglutaryl coenzyme A reductase-independent lycopene accumulation

    Rodriguez-Concepcion, M.; Gruissem, W. [Univ. of California, Berkeley, CA (United States). Dept. of Plant and Microbial Biology

    1999-01-01

    Regulation of isoprenoid end-product synthesis required for normal growth and development in plants is not well understood. To investigate the extent to which specific genes for the enzyme 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR) are involved in end-product regulation, the authors manipulated expression of the HMG1 and HMG2 genes in tomato (Lycopersicon esculentum) fruit using arachidonic acid (AA). In developing young fruit AA blocked fruit growth, inhibited HMG1, and activated HMG2 expression. These results are consistent with other reports indicating that HMG1 expression is closely correlated with growth processes requiring phytosterol production. In mature-green fruit AA strongly induced the expression of HMG2, PSY1 (the gene for phytoene synthase), and lycopene accumulation before the normal onset of carotenoid synthesis and ripening. The induction of lycopene synthesis was not blocked by inhibition of HMGR activity using mevinolin, suggesting that cytoplasmic HMGR is not required for carotenoid synthesis. Their results are consistent with the function of an alternative plastid isoprenoid pathway (the Rohmer pathway) that appears to direct the production of carotenoids during tomato fruit ripening.

  12. Growth Limits of Listeria monocytogenes as a Function of Temperature, pH, NaCl, and Lactic Acid

    Tienungoon, S.; Ratkowsky, D A; McMeekin, T A; Ross, T.

    2000-01-01

    Models describing the limits of growth of pathogens under multiple constraints will aid management of the safety of foods which are sporadically contaminated with pathogens and for which subsequent growth of the pathogen would significantly increase the risk of food-borne illness. We modeled the effects of temperature, water activity, pH, and lactic acid levels on the growth of two strains of Listeria monocytogenes in tryptone soya yeast extract broth. The results could be divided unambiguous...

  13. Assessment of factors limiting algal growth in acidic pit lakes-a case study from Western Australia, Australia.

    Kumar, R Naresh; McCullough, Clint D; Lund, Mark A; Larranaga, Santiago A

    2016-03-01

    Open-cut mining operations can form pit lakes on mine closure. These new water bodies typically have low nutrient concentrations and may have acidic and metal-contaminated waters from acid mine drainage (AMD) causing low algal biomass and algal biodiversity. A preliminary study was carried out on an acidic coal pit lake, Lake Kepwari, in Western Australia to determine which factors limited algal biomass. Water quality was monitored to obtain baseline data. pH ranged between 3.7 and 4.1, and solute concentrations were slightly elevated to levels of brackish water. Concentrations of N were highly relative to natural lakes, although concentrations of FRP (water quality. Microcosms of Lake Kepwari water were amended with N, P and C nutrients with and without sediment. Nutrient amendments under microcosm conditions could not show any significant phytoplankton growth but was able to promote benthic algal growth. P amendments without sediment showed a statistically higher mean algal biomass concentration than controls or microcosms amended with phosphorus but with sediment did. Results indicated that algal biomass in acidic pit lake (Lake Kepwari) may be limited primarily by low nutrient concentrations (especially phosphorus) and not by low pH or elevated metal concentrations. Furthermore, sediment processes may also reduce the nutrient availability. PMID:26593729

  14. Accumulation of intra-cellular polyphosphate in Chlorella vulgaris cells is related to indole-3-acetic acid produced by Azospirillum brasilense.

    Meza, Beatriz; de-Bashan, Luz E; Hernandez, Juan-Pablo; Bashan, Yoav

    2015-06-01

    Accumulation of intra-cellular phosphate, as polyphosphate, was measured when the microalga Chlorella vulgaris was immobilized in alginate with either of two wild-type strains of the microalgae growth-promoting bacterium Azospirillum brasilense or their corresponding IAA-attenuated mutants. Wild type strains of A. brasilense induced higher amounts of intra-cellular phosphate in Chlorella than their respective mutants. Calculations comparing intra-cellular phosphate accumulation by culture or net accumulation by the cell and the amount of IAA that was produced by each of these strains revealed that higher IAA was linked to higher accumulations of intra-cellular phosphate. Application of four levels of exogenous IAA reported for A. brasilense and their IAA-attenuated mutants to cultures of C. vulgaris enhanced accumulation of intra-cellular phosphate; the higher the content of IAA per culture or per single cell, the higher was the amount of accumulated phosphate. When an IAA-attenuated mutant was complemented with exogenous IAA, accumulation of intra-cellular phosphate at the culture level was even higher than phosphate accumulation with the respective wild type strains. When calculating the net accumulation of intra-cellular phosphate in the complementation experiment, net intra-cellular phosphate induced by the IAA-attenuated mutant was completely restored and was similar to the wild strains. We propose that IAA produced by A. brasilense is linked to polyphosphate accumulation in C. vulgaris. PMID:25797155

  15. Offspring from rat mothers fed a high-fat/high-sucrose diet during gestation and lactation accumulate free fatty acids in the liver when exposed to high fat diet as adults

    Hellgren, Lars; Ingvorsen, Camilla

    Introduction: Maternal diet during gestation and lactation has been implicated as a factor that modifies the risk of developing metabolic diseases later in life. Hepatic lipid accumulation is strongly linked to development of metabolic diseases. Free fatty acids induce ER stress, mitochondrial......-fostered by the dams, so that half of the pups born by HFHS mothers was lactated by C dams and vice versa, generating four groups; CC, CH, HC and HH (first letter maternal diet during pregnancy and the second diet during lactation). At weaning all pups were transferred to chow-diet and kept on this diet until...... caused strongly increased levels of hepatic free fatty acids (FFA) in rats both born and lactated by HFHS-dams. Principal component analysis of the FFA fatty acid composition showed that there were in particular dietary PUFA that accumulated, indicating that it is the ability to metabolize these fatty...

  16. Silencing Brassinosteroid Receptor BRI1 Impairs Herbivory-elicited Accumulation of Jasmonic Acid-isoleucine and Diterpene Glycosides, but not Jasmonic Acid and Trypsin Proteinase Inhibitors in Nicotiana attenuata

    Da-Hai Yang; lan T.Baldwin; Jianqiang Wu

    2013-01-01

    The brassinosteroid (BR) receptor,BR insensitive 1 (BRI1),plays a critical role in plant development,but whether BRI1-mediated BR signaling is involved in plant defense responses to herbivores was largely unknown.Here,we examined the function of BRI1 in the resistance of Nicotiana attenuata (Solanaceae) to its specialist insect herbivore Manduca sexta.Jasmonic acid (JA) and JA-isoleucine conjugate (JA-Ile) are important hormones that mediate resistance to herbivores and we found that after wounding or simulated herbivory NaBRI1 had little effect on JA levels,but was important for the induction of JA-Ile.Further experiments revealed that decreased JAR (the enzyme for JA-Ile production) activity and availability of lie in NaBRI1-silenced plants were likely responsible for the low JA-Ile levels.Consistently,M.sexta larvae gained more weight on NaBRI1-silenced plants than on the control plants.Quantification of insect feeding-induced secondary metabolites revealed that silencing NaBRI1 resulted in decreased levels of carbon-rich defensive secondary metabolites (hydroxygeranyllinalool diterpene glycosides,chlorogenic acid,and rutin),but had little effect on the nitrogen-rich ones (nicotine and trypsin proteinase inhibitors).Thus,NaBRI1-mediated BR signaling is likely involved in plant defense responses to M.sexta,including maintaining JA-Ile levels and the accumulation of several carbon-rich defensive secondary metabolites.

  17. Effects of low temperature on the sugar and ascorbic acid contents of komatsuna (Brassica campestris L.) under limited solar radiation

    The effects of low temperature on the sugar and ascorbic acid contents of Komatsuna (Brassica campestris L.) plants grown under limited solar radiation in the greenhouse were evaluated. Komatsuna plants were grown in a greenhouse in which the mean air temperature was maintained between 13 degree C and 15 degree C (defined as the 'cool temperature' condition). The solar radiation in the greenhouse fluctuated between 2 and 4 MJ/m2. day-l during the experiment. When Komatsuna plants grew to about 20 cm height, they were transferred to a greenhouse in which the mean air temperature fluctuated between 2 degree C and 3 degree C (defined as the 'cold temperature' or 'cold treatment'). The total sugar contents in leaf blades and in petioles of Komatsuna plants increased rapidly as a function of the cold treatment. The total ascorbic acid content in the leaf blades increased rapidly after the initiation of cold treatment, whereas that content in the petioles increased gradually. On the other hand, the composition of the leaf blades and petioles in the Komatsuna plants did not change when grown continuously in the cool plot. The data show that cold treatment promoted the per unit area production of the total sugar and total ascorbic acid. These results indicate that cold treatment could improve the nutritional qualities of Komatsuna plants, even under limited solar radiation in winter,

  18. Limitations in the use of 14C-glycocholate breath and stool bile acid determinations in patients with chronic diarrhea

    Analysis of a modified 14C-glycocholate breath test on 165 consecutive in-patients being investigated for chronic diarrhea showed that the measurement of 14CO2 between 3 and 6 h after oral dosing of 5 microCi of 14C-glycocholic acid was of only limited use to distinguish between patients with Crohn's disease (CD), idiopathic bile salt wastage (IBW), or ileal resection (IR) from those with the irritable bowel syndrome (IBS). Continuing 14CO2 collections for up to 24 h was of little more help in establishing the presence of bacterial overgrowth syndrome (BOS) and in distinguishing between BOS and CD. Stool bile acid measurements were of use in differentiating between IBW and IBS, but did not distinguish between CD and BOS or between CD and IR. Since the range of normal values was defined by measurements in the IBS group, a positive test was specific for an organic cause of chronic diarrhea. Even so, the sensitivity of the test was relatively low: CD, 53%; IR, 23%; IBW, 14%; and BOS, 10%. We believe that the 24-h 14C-glycocholic breath test combined with the measurement of stool bile acids represents a screening test of only limited use for the identification of organic causes of chronic diarrhea

  19. Improved docosahexaenoic acid production in Aurantiochytrium by glucose limited pH-auxostat fed-batch cultivation.

    Janthanomsuk, Panyawut; Verduyn, Cornelis; Chauvatcharin, Somchai

    2015-11-01

    Fed-batch, pH auxostat cultivation of the docosahexaenoic acid (DHA)-producing microorganism Aurantiochytrium B072 was performed to obtain high cell density and record high productivity of both total fatty acid (TFA) and DHA. Using glucose feeding by carbon excess (C-excess) and by C-limitation at various feeding rates (70%, 50% or 20% of C-excess), high biomass density was obtained and DHA/TFA content (w/w) was improved from 30% to 37% with a 50% glucose feed rate when compared with C-excess. To understand the biochemistry behind these improvements, lipogenic enzyme assays and in silico metabolic flux calculations were used and revealed that enzyme activity and C-fluxes to TFA were reduced with C-limited feeding but that the carbon flux to the polyketide synthase pathway increased relative to the fatty acid synthase pathway. As a result, a new strategy to improve the DHA to TFA content while maintaining relatively high DHA productivity is proposed. PMID:26298403

  20. Fatty acid oxidation in brain is limited by the low activity of 3-ketoacyl-CoA thiolase

    In an attempt to establish why the brain is virtually incapable of oxidizing fatty acids, the activities of the β-oxidation enzymes in rat brain and rat heart mitochondria were measured and compared with each other. Although the apparent K/sub m/ values and chain-length specificities of the brain and heart enzymes are similar, the specific activities of all but one brain enzyme are between 4% and 50% of those observed in heart mitochondria. The exception is 3-ketoacyl-CoA thiolase (EC 2.3.1.16) whose specific activity in brain mitochondria is 125-times lower than in heart mitochondria. The partially purified brain 3-ketoacyl-CoA thiolase was shown to be catalytically and immunologically identical with the heart enzyme. The low rate of fatty acid oxidation in brain mitochondria estimated on the basis of palmitoylcarnitine-supported respiration and [1-14C]palmitoylcarnitine degradation may be the consequence of the low activity of 3-ketoacyl-CoA thiolase. Inhibition of [1-14C]palmitoylcarnitine oxidation by 4-bromocrotonic acid proves that the observed oxidation of fatty acids in brain is dependent on 3-ketoacyl-CoA thiolase and thus occurs via β-oxidation. Since the reactions catalyzed by carnitine palmitoyltransferase (EC 2.3.1.21) and acyl-CoA synthetase (EC 6.2.1.3) do not seem to restrict fatty acid oxidation in brain, it is concluded that the oxidation of fatty acids in rat brain is limited by the activity of the mitochondrial 3-ketoacyl-CoA thiolase

  1. Investigation of intercellular salicylic acid accumulation during compatible and incompatible Arabidopsis-pseudomonas syringae interactions using a fast neutron-generated mutant allele of EDS5 identified by genetic mapping and whole-genome sequencing.

    Jessie L Carviel

    Full Text Available A whole-genome sequencing technique developed to identify fast neutron-induced deletion mutations revealed that iap1-1 is a new allele of EDS5 (eds5-5. RPS2-AvrRpt2-initiated effector-triggered immunity (ETI was compromised in iap1-1/eds5-5 with respect to in planta bacterial levels and the hypersensitive response, while intra- and intercellular free salicylic acid (SA accumulation was greatly reduced, suggesting that SA contributes as both an intracellular signaling molecule and an antimicrobial agent in the intercellular space during ETI. During the compatible interaction between wild-type Col-0 and virulent Pseudomonas syringae pv. tomato (Pst, little intercellular free SA accumulated, which led to the hypothesis that Pst suppresses intercellular SA accumulation. When Col-0 was inoculated with a coronatine-deficient strain of Pst, high levels of intercellular SA accumulation were observed, suggesting that Pst suppresses intercellular SA accumulation using its phytotoxin coronatine. This work suggests that accumulation of SA in the intercellular space is an important component of basal/PAMP-triggered immunity as well as ETI to pathogens that colonize the intercellular space.

  2. Solar-thermal complex sample processing for nucleic acid based diagnostics in limited resource settings

    Gumus, Abdurrahman; Ahsan, Syed; Dogan, Belgin; Jiang, Li; Snodgrass, Ryan; Gardner, Andrea; Lu, Zhengda; Simpson, Kenneth; Erickson, David

    2016-01-01

    The use of point-of-care (POC) devices in limited resource settings where access to commonly used infrastructure, such as water and electricity, can be restricted represents simultaneously one of the best application fits for POC systems as well as one of the most challenging places to deploy them. Of the many challenges involved in these systems, the preparation and processing of complex samples like stool, vomit, and biopsies are particularly difficult due to the high number and varied natu...

  3. Retinoic acid signaling acts via Hox1 to establish the posterior limit of the pharynx in the chordate amphioxus

    Schubert, Michael; Yu, Jr-Kai; Holland, Nicholas D; Escriva, Hector; Laudet, Vincent; Holland, Linda Z

    2004-01-01

    In the invertebrate chordate amphioxus, as in vertebrates, retinoic acid (RA) specifies position along the anterior/posterior axis with elevated RA signaling in the middle third of the endoderm setting the posterior limit of the pharynx. Here we show that AmphiHox1 is also expressed in the middle third of the developing amphioxus endoderm and is activated by RA signaling. Knockdown of AmphiHox1 function with an antisense morpholino oligonucleotide shows that AmphiHox1 mediates the role of RA ...

  4. Comparative study of two routes of administration of 5-aminolevulinic acid (oral and intratumoral via) and their effect on the accumulation of PpIX in tissues in murine model of breast cancer

    González-Agüero, G.; Ramón-Gallegos, E.

    2012-10-01

    Protoporphyrin IX (PpIX) is a photosensitizer synthesized from 5-aminolevulinic acid (ALA) that has been used in photodynamic therapy (PDT) as a promising treatment for many types of cancer. In this work it was quantified the accumulation of PpIX in tumors and in different tissues of female mice (nu/nu) inoculated with breast cancer cells. Two routes of administration of ALA: gastric probe and intratumoral injection were used to find optimum time of accumulation and the via that induce the higher quantity of PpIX to improve the efficiency of PDT. The results show that the accumulation of PpIX using the intratumoral via is two times bigger than the oral via in tumors at 8 h of treatment. The concentrations obtained in the different tissues are not physiologically significant.

  5. Glycerol-3-phosphate Acyltransferase Isoform-4 (GPAT4) Limits Oxidation of Exogenous Fatty Acids in Brown Adipocytes.

    Cooper, Daniel E; Grevengoed, Trisha J; Klett, Eric L; Coleman, Rosalind A

    2015-06-12

    Glycerol-3-phosphate acyltransferase-4 (GPAT4) null pups grew poorly during the suckling period and, as adults, were protected from high fat diet-induced obesity. To determine why Gpat4(-/-) mice failed to gain weight during these two periods of high fat feeding, we examined energy metabolism. Compared with controls, the metabolic rate of Gpat4(-/-) mice fed a 45% fat diet was 12% higher. Core body temperature was 1 ºC higher after high fat feeding. Food intake, fat absorption, and activity were similar in both genotypes. Impaired weight gain in Gpat4(-/-) mice did not result from increased heat loss, because both cold tolerance and response to a β3-adrenergic agonist were similar in both genotypes. Because GPAT4 comprises 65% of the total GPAT activity in brown adipose tissue (BAT), we characterized BAT function. A 45% fat diet increased the Gpat4(-/-) BAT expression of peroxisome proliferator-activated receptor α (PPAR) target genes, Cpt1α, Pgc1α, and Ucp1, and BAT mitochondria oxidized oleate and pyruvate at higher rates than controls, suggesting that fatty acid signaling and flux through the TCA cycle were enhanced. To assess the role of GPAT4 directly, neonatal BAT preadipocytes were differentiated to adipocytes. Compared with controls, Gpat4(-/-) brown adipocytes incorporated 33% less fatty acid into triacylglycerol and 46% more into the pathway of β-oxidation. The increased oxidation rate was due solely to an increase in the oxidation of exogenous fatty acids. These data suggest that in the absence of cold exposure, GPAT4 limits excessive fatty acid oxidation and the detrimental induction of a hypermetabolic state. PMID:25918168

  6. Multivariate detection limits of on-line NIR model for extraction process of chlorogenic acid from Lonicera japonica.

    Wu, Zhisheng; Sui, Chenglin; Xu, Bing; Ai, Lu; Ma, Qun; Shi, Xinyuan; Qiao, Yanjiang

    2013-04-15

    A methodology is proposed to estimate the multivariate detection limits (MDL) of on-line near-infrared (NIR) model in Chinese Herbal Medicines (CHM) system. In this paper, Lonicera japonica was used as an example, and its extraction process was monitored by on-line NIR spectroscopy. Spectra of on-line NIR could be collected by two fiber optic probes designed to transmit NIR radiation by a 2mm-flange. High performance liquid chromatography (HPLC) was used as a reference method to determine the content of chlorogenic acid in the extract solution. Multivariate calibration models were carried out including partial least squares regression (PLS) and interval partial least-squares (iPLS). The result showed improvement of model performance: compared with PLS model, the root mean square errors of prediction (RMSEP) of iPLS model decreased from 0.111mg to 0.068mg, and the R(2) parameter increased from 0.9434 to 0.9801. Furthermore, MDL values were determined by a multivariate method using the type of errors and concentration ranges. The MDL of iPLS model was about 14ppm, which confirmed that on-line NIR spectroscopy had the ability to detect trace amounts of chlorogenic acid in L. japonica. As a result, the application of on-line NIR spectroscopy for monitoring extraction process in CHM could be very encouraging and reliable. PMID:23376723

  7. 枇杷果实糖酸积累的分子生理机制%Review of the studies on the accumulation mechanisms of sugar and organic acids in Eriobotryajaponica fruit

    秦巧平; 林飞凡; 张岚岚

    2012-01-01

    糖酸含量及糖酸比是果实品质的重要指标.糖不仅决定果实甜度,也是色素、氨基酸、维生素和芳香物质等其他营养成分合成的基础原料.果实有机酸与糖一起形成糖酸比,决定果实风味,同时,果实有机酸作为呼吸底物为合成其他物质提供基础.糖酸比是影响果实口感的最主要因子.对糖酸代谢机制的阐明可为果树栽培管理及高品质育种提供理论依据.文章综述了近年来国内外有关枇杷Eriobotrya japonica糖酸代谢的生理学、分子生物学及栽培措施对糖酸积累的影响等方面的研究进展,并结合笔者的研究经验提出未来在枇杷糖酸代谢机制与调控方面的主要研究重点:进一步明确栽培措施和环境因子对果实糖酸代谢的影响及分子机制;探明果实糖、酸运输的分子机制;应用遗传工程调控果实糖酸组成;探明糖积累与酸积累的相互作用机制.%Sugar and acid content and sugar/acid ratio are the important indexes for fruit quality. Sugars not only determine fruit sweetness, but also provide raw materials for synthesis of pigment, ammo acids, vitamins and other nutrients and aromatic substances. Fruit acids and sugar form sugar/acid ratio, which decides fruit flavor. Meanwhile, fruit organic acids provide respiratory substrates for the synthesis of other essential substances. Sugar/acid ratio is one of the most important determiner for fruit quality. Sugar and organic acid metabolism processes are extremely complicated, the two pathways are closely connected. Understanding towards sugar and acid accumulation mechanism would provide important theoretical basis for cultivation and breeding. This article reviews the recent research advances on loquat (Eriobotrya japonica) sugar acid metabolism, physiology, molecular biology, and cultivation, etc, which will be helpful for related areas. Combining the authors' research experience, the possible researching focuses on

  8. Curcumin and Ellagic acid synergistically induce ROS generation, DNA damage, p53 accumulation and apoptosis in HeLa cervical carcinoma cells.

    Kumar, Devbrat; Basu, Soumya; Parija, Lucy; Rout, Deeptimayee; Manna, Sanjeet; Dandapat, Jagneshwar; Debata, Priya Ranjan

    2016-07-01

    Cervical cancer and precancerous lesions of the cervix continue to be a global health issue, and the medication for the treatment for chronic HPV infection so far has not been effective. Potential anticancer and anti HPV activities of two known phytochemicals, Curcumin and Ellagic acid were evaluated in HeLa cervical cancer cells. Curcumin is a natural compound found in the root of Curcuma longa plant and Ellagic acid a polyphenol found in fruits of strawberries, raspberries and walnuts. The combination of Curcumin and Ellagic acid at various concentrations showed better anticancer properties than either of the drug when used alone as evidenced by MTT assay. Besides this, Curcumin and Ellagic acid also restore p53, induce ROS formation and DNA damage. Mechanistic study further indicated that Curcumin and Ellagic acid show anti-HPV activity as evidenced by decrease in the HPV E6 oncoprotein on HeLa cells. PMID:27261574

  9. Does Glycine Betaine and Salicylic Acid Ameliorate the Negative Effect of Drought on Wheat by Regulating Osmotic Adjustment through Solutes Accumulation?

    Heshmat S. Aldesuquy

    2013-08-01

    Full Text Available A pot experiment was conducted to evaluate the beneficial effect of foliar application of glycine betaine (10mM, grain presoaking in salicylic acid (0.05 M and their interaction on drought tolerance of two wheat (Triticum aestivum L. cultivars (sensitive, Sakha 94 and resistant, Sakha 93. Osmotic pressure, some osmolytes concentration and grain yield were determined. Water stress caused an increase in osmotic pressure, proline, total soluble nitrogen, total soluble sugars, organic acids, ions (Na+, K+, Ca+2, Mg+2 and Cl- content as well as Na+/K+ ratio in cell sap flag leaves of both wheat cultivars. The resistant variety had higher values of osmotic pressure, proline, organic acids and ions content than the sensitive one. On the other hand, water stress induced marked decrease (P<0.05 in grain yield. The applied chemicals mitigated the effect of water stress on the used wheat cultivars. The effect was more pronounced with glycine betaine + salicylic acid treatment. The applied chemicals increased the osmotic pressure, the osmolytes concentrations as well as the grain yield. Furthermore, the osmotic pressure of flag leaf sap appeared to depend on proline, TSN, TSS, organic acids and the ions content. The economic yield (grain yield was positively correlated with proline, keto-acids and osmotic pressure but negatively correlated with TSN, TSS and citric acid.

  10. Excessive reactive oxygen species induces apoptosis in fibroblasts: Role of mitochondrially accumulated hyaluronic acid binding protein 1 (HABP1/p32/gC1qR)

    Constitutively expressed HABP1 in normal murine fibroblast cell line induces growth perturbation, morphological abnormalities alongwith initiation of apoptosis. Here, we demonstrate that though HABP1 accumulation started in mitochondria from 48 hr of growth, induction of apoptosis with the release of cytochrome c and apoptosome complex formation occurred only after 60 hr. This mitochondrial dysfunction was due to gradual increase in ROS generation in HABP1 overexpressing cells. Along with ROS generation, increased Ca2+ influx in mitochondria leading to drop in membrane potential was evident. Interestingly, upon expression of HABP1, the respiratory chain complex I was shown to be significantly inhibited. Electronmicrograph confirmed defective mitochondrial ultrastructure. The reduction in oxidant generation and drop in apoptotic cell population accomplished by disruption of HABP1 expression, corroborating the fact that excess ROS generation in HABP1 overexpressing cells leading to apoptosis was due to mitochondrial HABP1 accumulation

  11. Jasmonic acid accumulation and systemic photosynthetic and electrical changes in locally burned wild type tomato, ABA-deficient sitiens mutants and sitiens pre-treated by ABA

    Hlavinka, J.; Nožková-Hlaváčková, V.; Floková, Kristýna; Novák, Ondřej; Nauš, J.

    2012-01-01

    Roč. 54, May 2012 (2012), s. 89-96. ISSN 0981-9428 R&D Projects: GA ČR GD522/08/H003 Grant ostatní: GA MŠk(CZ) ED0007/01/01 Institutional research plan: CEZ:AV0Z50380511 Keywords : abscisic acid * gas exchange * jasmonic acid Subject RIV: CE - Biochemistry Impact factor: 2.775, year: 2012

  12. Field trial evaluation of the accumulation of omega-3 long chain polyunsaturated fatty acids in transgenic Camelina sativa: Making fish oil substitutes in plants

    Sarah Usher; Haslam, Richard P.; Noemi Ruiz-Lopez; Olga Sayanova; Napier, Johnathan A.

    2015-01-01

    The global consumption of fish oils currently exceeds one million tonnes, with the natural de novo source of these important fatty acids forming the base of marine foodwebs. Here we describe the first field-based evaluation of a terrestrial source of these essential nutrients, synthesised in the seeds of transgenic Camelina sativa plants via the heterologous reconstitution of the omega-3 long chain polyunsaturated fatty acid biosynthetic pathway. Our data demonstrate the robust nature of this...

  13. 5-Hydroxymethylfurfural (5-HMF) Production from Hexoses: Limits of Heterogeneous Catalysis in Hydrothermal Conditions and Potential of Concentrated Aqueous Organic Acids as Reactive Solvent System

    Nadine Essayem; Franck Rataboul; Rodrigo Lopes de Souza; Hao Yu

    2012-01-01

    5-Hydroxymethylfurfural (5-HMF) is an important bio-sourced intermediate, formed from carbohydrates such as glucose or fructose. The treatment at 150–250 °C of glucose or fructose in pure water and batch conditions, with catalytic amounts of most of the usual acid-basic solid catalysts, gave limited yields in 5-HMF, due mainly to the fast formation of soluble oligomers. Niobic acid, which possesses both Lewis and Brønsted acid sites, gave the highest 5-HMF yield, 28%, when high catalyst/gluco...

  14. Selective inhibition of jasmonic acid accumulation by a small α, β-unsaturated carbonyl and phenidone reveals different modes of octadecanoid signalling activation in response to insect elicitors and green leaf volatiles in Zea mays

    Engelberth Jurgen

    2011-10-01

    Full Text Available Abstract Background Plants often release a complex blend of volatile organic compounds (VOC in response to insect herbivore damage. Among those blends of VOC green leaf volatiles (GLV have been demonstrated to function as defence signals between plants, thereby providing protection against impending herbivory. A problem in understanding the mode of action of these 6-carbon aldehydes, alcohols, and esters is caused by their structural diversity. Besides different degrees of oxidation, E-2- as well as Z-3-configured isomers are often released. This study was therefore initiated to determine the structural requirement necessary to exhibit biological activity measured as jasmonic acid (JA accumulation in Zea mays seedlings. Findings The structure/function analysis of green leaf volatiles and related compounds revealed that an olefinic bond in position 2 or 3 and a size of 6-8 carbons is required for biological activity in maize. Also, it was found that the presence of an α, β-unsaturated carbonyl is not a prerequisite for activity. However, by treating plants first with volatile acrolein it was discovered that this smallest α, β-unsaturated carbonyl inhibits JA accumulation in response to insect elicitor treatment, but not after GLV exposure. This selective inhibitory effect was also found for phenidone, an inhibitor of lipoxygenases. These findings led to the discovery of a pool of protein-associated 12-oxo-phytodienoic acid, a biosynthetic precursor of JA, which appeared to be rapidly converted into JA upon exposure to GLV. Conclusions The structure/function analysis of GLV demonstrates a high degree of correlation between the compounds released by wounded plants in nature and their biological activity. The selective inhibitory effects of acrolein and phenidone on insect elicitor- and GLV-induced JA accumulation in maize led to the discovery of a pool of protein-associated precursor, which is rapidly activated and transformed to JA after

  15. Effect of short-chain fatty acids on triacylglycerol accumulation, lipid droplet formation and lipogenic gene expression in goat mammary epithelial cells.

    Sun, Yuting; Luo, Jun; Zhu, Jiangjiang; Shi, Hengbo; Li, Jun; Qiu, Siyuan; Wang, Ping; Loor, Juan J

    2016-02-01

    Short-chain fatty acids (SCFAs) are the major energy sources for ruminants and are known to regulate various physiological functions in other species. However, their roles in ruminant milk fat metabolism are still unclear. In this study, goat mammary gland epithelial cells (GMECs) were treated with 3 mmol/L acetate, propionate or butyrate for 24 h to assess their effects on lipogenesis. Data revealed that the content of triacylglycerol (TAG) and lipid droplet formation were significantly stimulated by propionate and butyrate. The expression of FABP3, SCD1, PPARG, SREBP1, DGAT1, AGPAT6 and ADRP were upregulated by propionate and butyrate treatment. In contrast, the messenger RNA (mRNA) expression of FASN and LXRα was not affected by propionate, but reduced by butyrate. Acetate had no obvious effect on the content of TAG and lipid droplets but increased the mRNA expression of SCD1 and FABP3 in GMECs. Additionally, it was observed that propionate significantly increased the relative content of mono-unsaturated fatty acids (C18:1 and C16:1) at the expense of decreased saturated fatty acids (C16:0 and C18:0). Butyrate and acetate had no significant effect on fatty acid composition. Overall, the results from this work help enhance our understanding of the regulatory role of SCFAs on goat mammary cell lipid metabolism. PMID:26304676

  16. Field trial evaluation of the accumulation of omega-3 long chain polyunsaturated fatty acids in transgenic Camelina sativa: Making fish oil substitutes in plants

    Sarah Usher

    2015-12-01

    Full Text Available The global consumption of fish oils currently exceeds one million tonnes, with the natural de novo source of these important fatty acids forming the base of marine foodwebs. Here we describe the first field-based evaluation of a terrestrial source of these essential nutrients, synthesised in the seeds of transgenic Camelina sativa plants via the heterologous reconstitution of the omega-3 long chain polyunsaturated fatty acid biosynthetic pathway. Our data demonstrate the robust nature of this novel trait, and the feasibility of making fish oils in genetically modified crops. Moreover, to our knowledge, this is the most complex example of plant genetic engineering to undergo environmental release and field evaluation.

  17. Does Glycine Betaine and Salicylic Acid Ameliorate the Negative Effect of Drought on Wheat by Regulating Osmotic Adjustment through Solutes Accumulation?

    Heshmat S. Aldesuquy; Mohamed A. Abbas; Abo-Hamed, Samy A.; Abeer H. Elhakem

    2013-01-01

    A pot experiment was conducted to evaluate the beneficial effect of foliar application of glycine betaine (10mM), grain presoaking in salicylic acid (0.05 M) and their interaction on drought tolerance of two wheat (Triticum aestivum L.) cultivars (sensitive, Sakha 94 and resistant, Sakha 93). Osmotic pressure, some osmolytes concentration and grain yield were determined. Water stress caused an increase in osmotic pressure, proline, total soluble nitrogen, total so...

  18. Culture Conditions stimulating high γ-Linolenic Acid accumulation by Spirulina platensis Condições de cultura simulando o levado acúmulo de ácido γ-linolênico por Spirulina platensis

    Srinivasa Reddy Ronda

    2008-12-01

    Full Text Available Gamma-linolenic acid (GLA production by Spirulina platensis under different stress-inducing conditions was studied. Submerged culture studies showed that low temperature (25ºC, strong light intensity (6 klux and primrose oil supplement (0.8%w/v induced 13.2 mg/g, 14.6 mg/g and 13.5 mg linolenic acid per gram dry cell weight respectively. A careful observation of fatty acid profile of the cyanobacteria shows that, oleic acid and linoleic acid, in experiments with varying growth temperature and oil supplements respectively, helped in accumulating excess γ-linolenic acid. In addition, cultures grown at increasing light regimes maintained the γ-linolenic acid to the total fatty acid ratio(GLA/TFA constant, despite any change in γ-linolenic acid content of the cyanobacteria.Estudou-se a produção de ácido γ-linolênico por Spirulina platensis em diferentes condições de estresse. Culturas submersas indicaram que temperatura baixa (25ºC, forte intensidade de luz (6 klux e suplementação com óleo de prímula (0,8% p/v induziram a produção de ácido linolênico de 13,2 mg/g, 14,6 mg/g e 13,5 mg/g peso seco, respectivamente. Uma observação cuidadosa do perfil de ácidos graxos da cianobacteria indica que os ácidos oléico e linoléico, em experimentos com diferentes temperaturas de crescimento e suplementos de óleo, auxiliaram no acúmulo de excesso de ácido γ-linolênico. Além disso, as culturas obtidas em intensidades crescentes de luz mantiveram a relação ácido γ-linolênico/ácidos graxos totais constante, independentemente de qualquer mudança no conteúdo de ácido γ-linolênico da cianobactéria.

  19. Low Temperature-Induced 30 (LTI30) positively regulates drought stress resistance in Arabidopsis: effect on abscisic acid sensitivity and hydrogen peroxide accumulation

    Shi, Haitao; Chen, Yinhua; Qian, Yongqiang; Chan, Zhulong

    2015-01-01

    As a dehydrin belonging to group II late embryogenesis abundant protein (LEA) family, Arabidopsis Low Temperature-Induced 30 (LTI30)/XERO2 has been shown to be involved in plant freezing stress resistance. However, the other roles of AtLTI30 remain unknown. In this study, we found that the expression of AtLTI30 was largely induced by drought stress and abscisic acid (ABA) treatments. Thereafter, AtLTI30 knockout mutants and overexpressing plants were isolated to investigate the possible invol...

  20. 有机酸与根表铁膜对茶树吸收和富集氟的影响%Effects of organic acids and iron plaque outside roots on absorption and accumulation of fluoride in tea plants

    刘腾腾; 赵强; 郜红建; 宛晓春; 张正竹

    2013-01-01

    The effects of Fe2+ concentration,Fe2+ incubation time,pH and organic acids including oxalic acid,malic acid and citric acid on iron plaque on root surfaces and fluoride absorption and accumulation in tea plants were investigated in the hydroponics condition. Results showed that most of the iron plaque induced on tea roots was concentrated between 0. 2 cm and 0. 5 cm from the root tip. As the Fe2+ concentration and incubation time increased, the amount of iron plaque increased, but negative relationships were found when pH as well as organic acids concentrations increased. When the amount of iron plaque was 2.40 to 13. 60 mg·g-1,there was a positive relationship between fluoride adsorption and accumulation in tea plants and the iron plaque. Compared with CK1 without iron plaque and organic acids treatment, the amount of fluoride accumulated in tea plants increased between 42. 3% and 103. 7% with only Fe2+ treated. And it increased from 101.7% to 243.0% as the organic acids and Fe2+were added into the hydroponics solution together.%采用溶液培养法,研究了Fe2+质量浓度、Fe2+诱导时间、pH值、外源有机酸(草酸、苹果酸、柠檬酸)对根表铁膜形成及茶树吸收、富集氟的影响.结果表明:茶树根表铁膜主要集中在离根尖0.2~0.5 cm区域;茶树根表铁膜含量随Fe2+诱导时间的延长呈现先升高后降低的趋势,随Fe2+质量浓度的增加显著升高,与溶液pH、有机酸浓度呈负相关.当铁膜含量为2.40 ~ 13.60 mg·g-1,根表铁膜含量与茶树吸收、富集氟的能力呈正相关.与根表无铁膜的茶树单加氟处理的对照(CK1)相比,加Fe2+诱导形成铁膜后,茶树体内氟的含量增加了42.3% ~ 103.7%;有机酸与Fe2+共同作用时,茶树体内氟含量显著增加了101.7% ~243.0%.

  1. Tricarboxylic acid cycle intermediates accumulate at the onset of intense exercise in man but are not essential for the increase in muscle oxygen uptake

    Bangsbo, Jens; Gibala, Martin J.; Howarth, Krista R.; Krustrup, Peter

    2006-01-01

    It was proposed that a contraction-induced increase in tricarboxylic acid cycle intermediates (TCAI) is obligatory for the increase in muscle oxygen uptake at the start of exercise. To test this hypothesis, we measured changes in muscle TCAI during the initial seconds of intense exercise and used...... seconds of exercise; however, this increase is not essential for the contraction-induced increase in mitochondrial respiration.......It was proposed that a contraction-induced increase in tricarboxylic acid cycle intermediates (TCAI) is obligatory for the increase in muscle oxygen uptake at the start of exercise. To test this hypothesis, we measured changes in muscle TCAI during the initial seconds of intense exercise and used...... dichloroacetate (DCA) in an attempt to alter the level of TCAI. Five men performed strenuous leg kicking exercise (64+/-8 W) under noninfused control (CON) and DCA-supplemented conditions; biopsies (vastus lateralis) were obtained at rest and after 5, 15, and 180 s of exercise. In CON, the total concentration of...

  2. 腐殖酸对重茬烤烟氮积累及产量与质量的影响%Effects of humic acid on nitrogen accumulation,production and quality of continuously cropped and flue-cured tobacco

    张吉立; 孙海人; 孟蕾; 肖瑶; 王鹏

    2015-01-01

    为研究腐殖酸对克服烤烟重茬障碍的效果,试验在田间试验条件下设置对照(B1),当地常规施肥(B2),腐殖酸复混肥(B3)3个处理,研究了烤烟氮积累与烟叶品质变化规律。结果表明:根系氮积累生育期内呈现出增加的趋势,收获期B3处于最高值,与B2相比提高32.62%;茎内氮积累成熟期B3比B2处理提高41.62%,差异显著;下部叶成熟期B3比B2处理提高35.37%;中部叶B3比B2处理提高14.61%,差异显著;上部叶B3比B2处理提高32.64%,差异显著;B3促进氮在茎内的分配,比B1和B2处理分别提高5.27%、1.84%;B3产量与产值分别比B2提高6.94%、7.94%,烟叶质量评分下部叶、中部叶、上部叶分别低于B2处理1.50分、2.00分、2.00分。综合分析认为,腐殖酸对提高烤烟氮积累量和产量效果最佳。%In order to study the effects of humic acid in overcoming cropping obstacles of flue-cured tobacco ,three trials in the field were set including control (B1 ) ,local conventional fertilization (B2 ) ,and humic acid fertilizer (B3 ) , to investigate the changes of nitrogen accumulation and quality in flue-cured tobacco .The results showed that root nitro-gen accumulation tended to be increased during reproduction ,reaching the highest level with B3 treatment ,32 .62%higher than that by B2 during harvest .Stem nitrogen accumulation with B3 treatment was 41 .62% higher than that with B2 ,exhibiting significant differences .Nitrogen accumulation in lower leaves with B3 treatment was 35 .37% higher than that with B2 treatment .Middle leaves with B3 were 14 .61% higher than those with B2 treatment ,displaying significant differences .Upper leaves with B3 were 32 .64% higher than those with B2 treatment ,showing significant differences . B3 treatment promoted distribution of nitrogen into stem ,5 .27% and 1 .84% higher than B1 and B2 treatments ,respec-tively .Yield

  3. Metal accumulating plants: Medium's role

    Rabier, J.; Prudent, P.; Szymanska, B.; Mevy, J.-P.

    2003-05-01

    To evaluate phytoremediation potentialities by metal accumulation in tolerant plants, trials are carried out using in vitro cultures. Organie compounds influence on metal accumulation is studied with metals supplemented media. The tested compounds on zinc and lead absorption by Brassica juncea, are chelating agents (EDTA, citric acid) and soluble organic fractions of compost. EDTA seems to enhance the transfer of lead in plant but it is the opposite in the case of zinc. Citric acid stimulates root absorption for both zinc and lead. For the aqueous extracts of compost, variable effects are obtained according to the origin of compost (green wastes and food wastes). In'all tested conditions of cultures, zinc is mainly exported towards shoot while lead is stored in root.

  4. Norvaline is accumulated after a down-shift of oxygen in Escherichia coli W3110

    Bernhardt Jörg

    2008-10-01

    Full Text Available Abstract Background Norvaline is an unusual non-proteinogenic branched-chain amino acid which has been of interest especially during the early enzymological studies on regulatory mutants of the branched-chain amino acid pathway in Serratia marcescens. Only recently norvaline and other modified amino acids of the branched-chain amino acid synthesis pathway got attention again when they were found to be incorporated in minor amounts in heterologous proteins with a high leucine or methionine content. Earlier experiments have convincingly shown that norvaline and norleucine are formed from pyruvate being an alternative substrate of α-isopropylmalate synthase, however so far norvaline accumulation was not shown to occur in non-recombinant strains of E. coli. Results Here we show that oxygen limitation causes norvaline accumulation in E. coli K-12 W3110 during grow in glucose-based mineral salt medium. Norvaline accumulates immediately after a shift to oxygen limitation at high glucose concentration. On the contrary free norvaline is not accumulated in E. coli W3110 in aerobic cultures. The analysis of medium components, supported by transcriptomic studies proposes a purely metabolic overflow mechanism from pyruvate into the branched chain amino acid synthesis pathway, which is further supported by the significant accumulation of pyruvate after the oxygen downshift. The results indicate overflow metabolism from pyruvate as necessary and sufficient, but deregulation of the branched chain amino acid pathway may be an additional modulating parameter. Conclusion Norvaline synthesis has been so far mainly related to an imbalance of the synthesis of the branched chain amino acids under conditions were pyruvate level is high. Here we show that simply a downshift of oxygen is sufficient to cause norvaline accumulation at a high glucose concentration as a consequence of the accumulation of pyruvate and its direct chain elongation over α-ketobutyrate and

  5. 5-Hydroxymethylfurfural (5-HMF Production from Hexoses: Limits of Heterogeneous Catalysis in Hydrothermal Conditions and Potential of Concentrated Aqueous Organic Acids as Reactive Solvent System

    Nadine Essayem

    2012-09-01

    Full Text Available 5-Hydroxymethylfurfural (5-HMF is an important bio-sourced intermediate, formed from carbohydrates such as glucose or fructose. The treatment at 150–250 °C of glucose or fructose in pure water and batch conditions, with catalytic amounts of most of the usual acid-basic solid catalysts, gave limited yields in 5-HMF, due mainly to the fast formation of soluble oligomers. Niobic acid, which possesses both Lewis and Brønsted acid sites, gave the highest 5-HMF yield, 28%, when high catalyst/glucose ratio is used. By contrast, we disclose in this work that the reaction of fructose in concentrated aqueous solutions of carboxylic acids, formic, acetic or lactic acids, used as reactive solvent media, leads to the selective dehydration of fructose in 5-HMF with yields up to 64% after 2 hours at 150 °C. This shows the potential of such solvent systems for the clean and easy production of 5-HMF from carbohydrates. The influence of adding solid catalysts to the carboxylic acid media was also reported, starting from glucose.

  6. Exercise bicycle for accumulator charging

    Nekvapil, Jan

    2014-01-01

    Bachelor thesis is about possible solution construction of exercise bicycle with electric part working as a electric source. The first part of document introduces readers to issues about lead acid accumulators and charging, electronically commutated motors and electric converters. The second part shows potential solving constitution of exercise bicycle and we choose components and devices. EC motor will be connected with exercise bicycle by chain transmission. Transfer energy is realized thro...

  7. Uptake and Accumulation of Nephrotoxic and Carcinogenic Aristolochic Acids in Food Crops Grown in Aristolochia clematitis-Contaminated Soil and Water.

    Li, Weiwei; Hu, Qin; Chan, Wan

    2016-01-13

    Emerging evidence has suggested aristolochic acids (AAs) are linked to the development of Balkan endemic nephropathy (BEN), a chronic renal disease affecting numerous farmers living in the Balkan peninsula. However, the pathway by which AAs enter the human food chain and cause kidney disease remains poorly understood. Using our previously developed analytical method with high sensitivity and selectivity (Chan, W.; Lee, K. C.; Liu, N.; Cai, Z. J. Chromatogr. A 2007, 1164, 113-119), we quantified AAs in lettuce, tomato, and spring onion grown in AA-contaminated soil and culture medium. Our study revealed that AAs were being taken up from the soil and bioaccumulated in food crops in a time- and dose-dependent manner. To the best of our knowledge, this study is the first to identify one of the possible pathways by which AAs enter our food chain to cause chronic food poisoning. Results also demonstrated that AAs were resistant to the microbial activity of the soil/water. PMID:26654710

  8. Accumulation of radioactivity in rat brain and peripheral tissues including salivary gland after intravenous administration of {sup 14}C-D-aspartic acid

    Imai, Kazuhiro; Fukushima, Takeshi; Santa, Tomofumi; Homma, Hiroshi [Tokyo Univ. (Japan). Faculty of Pharmaceutical Sciences; Sugihara, Juko; Kodama, Hirohiko; Yoshikawa, Masayoshi

    1997-03-01

    After the intravenous administration of {sup 14}C-D-aspartic acid (Asp) into Sprague-Dawley rats (male, 7-week-old), the distribution and elimination of radioactivity was investigated by the whole body autoradiography. High radioactivities were detected in pineal gland, pituitary gland and salivary gland at 30 min after administration. The other tissues detected were liver, lung, adrenal gland, pancreas and spleen where D-Asp was reported to occur naturally. After 24 hr, the radioactivities were still detected at high levels in the pineal, pituitary and salivary glands. The data suggested the natural occurrence of D-Asp in salivary gland. After careful examination utilizing fluorescent derivatization and chiral separation by high-performance liquid chromatography, the presence of D-Asp was, for the first time, demonstrated in salivary gland in situ, the concentration of which was 7.85 {+-} 1.0 nmol/g. The administration of {sup 14}C-L-Asp was also carried out. The data suggested that D-Asp in the circulating blood is one of the sources of the tissue D-Asp. (author)

  9. Brain region-specific perfluoroalkylated sulfonate (PFSA) and carboxylic acid (PFCA) accumulation and neurochemical biomarker responses in east Greenland polar bears (Ursus maritimus)

    Pedersen, Kathrine Eggers; Basu, Niladri; Letcher, Robert J.;

    2015-01-01

    MAO activity in occipital lobe (e.g. ∑PFCA; rp=0.83, p=0.041, n=6) and across brain regions (e.g. ∑PFCA; rp=0.47, p=0.001, ∑PFSA; rp=0.44, p>0.001; n=50). GABA-A receptor density was positively correlated with two PFASs across brain regions (PFOS; rp=0.33, p=0.02 and PFDoDA; rp=0.34, p=0.014; n=52...... regions, whereas GS activity was positively correlated with PFASs primarily in occipital lobe. Results from the present study support the hypothesis that PFAS concentrations in polar bears from East Greenland have exceeded the threshold limits for neurochemical alterations. It is not known whether the...

  10. Trans-10,cis-12 conjugated linoleic acid (CLA) interferes with lipid droplet accumulation during 3T3-L1 preadipocyte differentiation.

    Yeganeh, Azadeh; Taylor, Carla G; Tworek, Leslee; Poole, Jenna; Zahradka, Peter

    2016-07-01

    In this study, we hypothesize that the biologically active isomers of conjugated linoleic acid (CLA), cis-9,trans-11 (c9,t11) and trans-10,cis-12 (t10,c12) CLA, have different effects on early and late stages 3T3-L1 preadipocyte differentiation. Both c9-t11 and t10-c12CLA stimulated early stage pre-adipocyte differentiation (day 2), while t10-c12CLA inhibited late differentiation (day 8) as determined by lipid droplet numbers and both perilipin-1 levels and phosphorylation state. At day 8, the adipokines adiponectin, chemerin and adipsin were all reduced in t10-c12CLA treated cells versus control cells. Immunofluorescence microscopy showed perilipin-1 was present solely on lipid droplets on day 8 in t10-c12 treated 3T3-L1 cells, whereas preilipin-1 was also located in the perinuclear region in control and c9-t11 treated cells. The t10-c12CLA isomer also decreased levels of hormone-sensitive lipase and inhibited lipolysis. These findings indicate that the decrease in lipid droplets caused by t10-c12CLA is the result of an inhibition of lipid droplet production during adipogenesis rather than a stimulation of lipolysis. Additionally, treatment with Gö6976 blocked the effect of t10-c12CLA on perilipin-1 phosphorylation, implicating PKCα in perilipin-1 phosphorylation, and thus a regulator of triglyceride catabolism. These data are supported by evidence that t10-c12CLA activated PKCα. These are the first data to show that CLA isomers can affect lipid droplet dynamics in adipocytes through PKCα. PMID:27131602

  11. Bile acids induce glucagon-like peptide 2 secretion with limited effects on intestinal adaptation in early weaned pigs

    Ipharraguerre, Ignacio R; Tedó, Gemma; Menoyo, David; de Diego Cabero, Nuria; Holst, Jens Juul; Nofrarías, Miquel; Mereu, Alessandro; Burrin, Douglas G

    2013-01-01

    Early weaning is a stressful event characterized by a transient period of intestinal atrophy that may be mediated by reduced secretion of glucagon-like peptide (GLP) 2. We tested whether enterally fed bile acids or plant sterols could increase nutrient-dependent GLP-2 secretion and improve...

  12. 白色紫锥菊不定根诱导及咖啡酸衍生物积累研究%Induction of adventitious roots of Echinacea pallida and accumulation of caffeic acid derivatives

    吴春华; 黄韬; 崔锡花; 白基烨

    2012-01-01

    以白色紫锥菊试管苗子叶为外植体,研究了植物生长素2,4-D,IAA,IBA,NAA对不定根诱导以及IBA浓度对液体悬浮培养中不定根的生长及咖啡酸衍生物积累的影响,并进行了生物反应器培养.结果表明,对白色紫锥不定根诱导最适合植物生长素是IBA1.0mg· L-1,不定根诱导数目达到22.5根/培养皿.液体悬浮培养中IBA 1.0 mg·L-1最适合不定根生长及咖啡酸衍生物的积累.白色紫锥菊不定根在5L气升式生物反应器中培养30 d后可获得8.98 g· L-1干重,是三角瓶悬浮培养干重4.38 g·L-1的2.05倍;生物反应器培养的不定根中紫锥菊苷质量分数为14.08 mg·g-1(干重),是栽培根的2.4倍;氯原酸,菊苣酸,总咖啡酸衍生物含量是栽培根的4.0 ~25.6倍.该研究为大量生产紫锥菊药品可提供富含紫锥菊苷等咖啡酸衍生物的高品质生物医学药材.%Objective:To investigate the effect of auxins 2,4-D, IAA, IBA, NAA on induction of adventitious roots as well as that of IBA concentrations on the growth of adventitious roots and the accumulation of caffeic acid derivatives, with test-tube seedling leaves Echinacea pallida as the explant,and cultivate adventitious roots in bioreactors. Result: 1.0 mg·L-1 IBA was found the best for the induction of adventitious roots,with the numer of induced adventitious roots up to 22. 5 in each culture dish. Among different concentrations for suspension cultivation of IBA tested, 1. 0 mg·L-1lBA was found the most suitable for the growth of adventitious roots and the accumulation of caffeic acid derivatives. In a 5 L balloon type bubble bioreactor,8. 98 g·L-1 dry weight was achieved after one month,which was 2. 05 times of 4. 38 g·L-1 dry weight cultivated in a triangular flask. The content of echinacoside cultivated in a bioreactor was 14. 08 mg g -1 DW, which was 2. 4 times of cultivated roots. The contents of chlorogenic acid, chicoric acid and total caffeic acid derivatives were

  13. Monitoring the influence of marine aquaculture on wild fish communities: benefits and limitations of fatty acid profiles

    Fernandez-Jover, Damian; Arechavala-Lopez, Pablo; Martínez Rubio, Laura; Tocher, Douglas R.; Bayle-Sempere, Just T.; López-Jiménez, José Ángel; Martínez-López, Francisco Javier; Sanchez-Jerez, Pablo

    2011-01-01

    Fatty acids (FA) have been applied as indicators of the influence of coastal sea-cage fish farming on wild fish communities in several recent scientific publications. Due to the relatively high conservation of FA composition throughout the food web, they are useful for characterizing trophic relationships. The increasing utilization of vegetable or alternative animal oils in the production of aquafeeds results in cultivated fish exhibiting higher levels of terrestrial FAs in their tissues. As...

  14. Energy Efficiency Limits For A Recuperative Bayonet Sulfuric Acid Decomposition Reactor For Sulfur Cycle Thermochemical Hydrogen Production

    A recuperative bayonet reactor design for the high-temperature sulfuric acid decomposition step in sulfur-based thermochemical hydrogen cycles was evaluated using pinch analysis in conjunction with statistical methods. The objective was to establish the minimum energy requirement. Taking hydrogen production via alkaline electrolysis with nuclear power as the benchmark, the acid decomposition step can consume no more than 450 kJ/mol SO2 for sulfur cycles to be competitive. The lowest value of the minimum heating target, 320.9 kJ/mol SO2, was found at the highest pressure (90 bar) and peak process temperature (900 C) considered, and at a feed concentration of 42.5 mol% H2SO4. This should be low enough for a practical water-splitting process, even including the additional energy required to concentrate the acid feed. Lower temperatures consistently gave higher minimum heating targets. The lowest peak process temperature that could meet the 450-kJ/mol SO2 benchmark was 750 C. If the decomposition reactor were to be heated indirectly by an advanced gas-cooled reactor heat source (50 C temperature difference between primary and secondary coolants, 25 C minimum temperature difference between the secondary coolant and the process), then sulfur cycles using this concept could be competitive with alkaline electrolysis provided the primary heat source temperature is at least 825 C. The bayonet design will not be practical if the (primary heat source) reactor outlet temperature is below 825 C.

  15. Metabolic regulation of Escherichia coli and its phoB and phoR genes knockout mutants under phosphate and nitrogen limitations as well as at acidic condition

    Shimizu Kazuyuki

    2011-05-01

    Full Text Available Abstract Background The phosphorus compounds serve as major building blocks of many biomolecules, and have important roles in signal transduction. The phosphate is involved in many biochemical reactions by the transfer of phosphoryl groups. All living cells sophisticatedly regulate the phosphate uptake, and survive even under phosphate-limiting condition, and thus phosphate metabolism is closely related to the diverse metabolism including energy and central carbon metabolism. In particular, phosphorylation may play important roles in the metabolic regulation at acidic condition and nitrogen limiting condition, which typically appears at the late growth phase in the batch culture. Moreover, phosphate starvation is a relatively inexpensive means of gene induction in practice, and the phoA promoter has been used for overexpression of heterologous genes. A better understanding of phosphate regulation would allow for optimization of such processes. Results The effect of phosphate (P concentration on the metabolism in Escherichia coli was investigated in terms of fermentation characteristics and gene transcript levels for the aerobic continuous culture at the dilution rate of 0.2 h-1. The result indicates that the specific glucose consumption rate and the specific acetate production rate significantly increased, while the cell concentration decreased at low P concentration (10% of the M9 medium. The increase in the specific glucose uptake rate may be due to ATP demand caused by limited ATP production under P-limitation. The lower cell concentration was also caused by less ATP production. The less ATP production by H+-ATPase may have caused less cytochrome reaction affecting in quinone pool, and caused up-regulation of ArcA/B, which repressed TCA cycle genes and caused more acetate production. In the case of phoB mutant (and also phoR mutant, the fermentation characteristics were less affected by P-limitation as compared to the wild type where the Pho

  16. ENERGY EFFICIENCY LIMITS FOR A RECUPERATIVE BAYONET SULFURIC ACID DECOMPOSITION REACTOR FOR SULFUR CYCLE THERMOCHEMICAL HYDROGEN PRODUCTION

    Gorensek, M.; Edwards, T.

    2009-06-11

    A recuperative bayonet reactor design for the high-temperature sulfuric acid decomposition step in sulfur-based thermochemical hydrogen cycles was evaluated using pinch analysis in conjunction with statistical methods. The objective was to establish the minimum energy requirement. Taking hydrogen production via alkaline electrolysis with nuclear power as the benchmark, the acid decomposition step can consume no more than 450 kJ/mol SO{sub 2} for sulfur cycles to be competitive. The lowest value of the minimum heating target, 320.9 kJ/mol SO{sub 2}, was found at the highest pressure (90 bar) and peak process temperature (900 C) considered, and at a feed concentration of 42.5 mol% H{sub 2}SO{sub 4}. This should be low enough for a practical water-splitting process, even including the additional energy required to concentrate the acid feed. Lower temperatures consistently gave higher minimum heating targets. The lowest peak process temperature that could meet the 450-kJ/mol SO{sub 2} benchmark was 750 C. If the decomposition reactor were to be heated indirectly by an advanced gas-cooled reactor heat source (50 C temperature difference between primary and secondary coolants, 25 C minimum temperature difference between the secondary coolant and the process), then sulfur cycles using this concept could be competitive with alkaline electrolysis provided the primary heat source temperature is at least 825 C. The bayonet design will not be practical if the (primary heat source) reactor outlet temperature is below 825 C.

  17. Oxygen limitation induces acid tolerance and impacts simulated gastro-intestinal transit in Listeria monocytogenes J0161

    Sewell, Danny; Allen, Stuart CH; Phillips, Carol A

    2015-01-01

    ᅟ Listeria monocytogenes is a food-borne pathogen and the causative agent of listeriosis, a severe infection to those with a pre-disposition. Infections often arise through consumption of contaminated foods, where high intrinsic resistance to food processing practises permit survival and growth. Several practises, including refrigeration, acidification and oxygen limitation are ineffective in controlling L. monocytogenes, therefore foods which do not undergo thermal processing, e.g. ready-to-...

  18. Effect of Humic Acid Application on Nitrate Accumulation in Edible-type Sweet Potato Tuberous Root%腐植酸对食用型甘薯块根硝酸盐积累的影响

    柴沙沙; 史春余; 张立明; 柳洪鹃; 王翠娟

    2013-01-01

    The sweet potato cultivar Beijing 553 was used to study the effects of humic acid (HA) on the nitrate accumulation in tuberous root under pool culture. The results showed that the application of HA reduced the nitrate content and the total nitrogen content in harvest time in sweet potato roots, but increased the nitrate reductase activity and total nitrogen of tuberous roots in early - middle period and the glutamine syn-thetase (GS) activity of functional leaves.%采用池栽方式,以北京553为试材,研究了腐植酸对甘薯块根硝酸盐积累的影响.结果表明,施用腐植酸降低了甘薯块根中硝酸盐含量,提高了前、中期功能叶片硝酸还原酶活性和块根中全氮含量,降低了收获期块根全氮含量,提高了块根和叶片中谷氨酰胺合成酶活性.

  19. Trans-Splicing Adeno-Associated Viral Vector-Mediated Gene Therapy Is Limited by the Accumulation of Spliced mRNA but Not by Dual Vector Coinfection Efficiency

    XU, ZHUPING; Yue, Yongping; Lai, Yi; Ye, Chaoyang; Qiu, Jianming; Pintel, David J.; Duan, Dongsheng

    2004-01-01

    Therapeutic application of recombinant adeno-associated virus (AAV) has been limited by its small carrying capacity. To overcome this limitation trans-splicing vectors were developed recently. However, the transduction efficiency of trans-splicing vectors is considerably lower than that of a single intact vector in skeletal muscle. To improve trans-splicing vectors for skeletal muscle gene therapy, we examined whether coinfection efficiency is a rate-limiting factor in the mdx mouse, a model ...

  20. Limitations of rat carotid balloon de-endothelialization model in arterial photodynamic therapy: a study using 5-aminolaevulinic acid

    Nyamekye, Isaac; MacRobert, Alexander J.; Bishop, Christopher C. R.; Bown, Stephen G.

    1995-05-01

    Photodynamic therapy (PDT) effectively inhibits fibrocellular intimal hyperplasia (FCIH) two and four weeks after arterial traction balloon injury in rat carotid arteries. The aim of the present study was to assess the long term effects of PDT in this rat model of FCIH. 5- aminolaevulinic acid-induced protoporphyrin IX was used to sensitize rats for PDT after traction balloon arterial injury to the whole of the left common carotid artery. Rats were sacrificed at intervals of six to 26 weeks, and perfusion fixed and H and E stained sections were analyzed using computerized morphometry. PDT inhibition of FCIH was only partial at these late times. The amount of FCIH present increased with increasing time after injury. The late occurrence of FCIH appeared to be due to migration of FCIH from balloon injured areas outside the PDT treated field as a result of the traction injury being applied to the whole carotid. We recommend segmental balloon injury rather than the traction injury of the whole common carotid injury for future studies in this model.

  1. Addition of Ctric Acid for Stimulating Catalase Accumulation by Serratia marcescens%添加柠檬酸促进粘质沙雷氏菌发酵产过氧化氢酶

    贺仁艳; 蔡宇杰; 廖祥儒; 李婷婷; 张大兵

    2011-01-01

    在优化1株粘质沙雷氏菌发酵产过氧化氢酶(CAT)的培养基成分时发现,柠檬酸可以显著提高该菌胞内CAT的活力。结合先前报道,探究了柠檬酸促进粘质沙雷氏菌合成胞内CAT的原因。以等摩尔碳含量的柠檬酸、葡萄糖、柠檬酸与葡萄糖的混合物分别作为碳源,测定了在不同碳源发酵产CAT时粘质沙雷氏菌胞内抗氧化的相关数据。结果显示:添加柠檬酸(20g/L)后,该菌细胞内H2O2和羟自由基含量均比对照组(葡萄糖)高,说明柠檬酸代谢物对其产生了活性氧胁迫,进而诱导更多CAT的合成。考察了甲萘醌和百草枯(活性氧O2^-·的来源物)对该菌合成CAT的影响,实验结果验证了适量的活性氧能够诱导该菌合成CAT的结论。%In an experiment to optimize the culture conditions for the catalase(CAT) production by Serratia marcescens SYBCT02,an interesting phenomenon occurred that the addition of ctric acid to the culture medium significantly stimulated the accumulation of CAT.To explore the reason for this finding,an experiment was designed based on the previous reports.Three kinds of carbon source,i.e.glucose,ctric acid and a mixture constituted by glucose and citric acid,with the same amount of carbon element,were used in the culture medium for CAT production by Serratia marcescens SYBCT02.After determining the contents of cellular antioxidant substrates and the activities of cellular antioxidant enzymes,an occurrence of oxidative stress was found in the cells of Serratia marcescens SYBCT02 cultivated in the media with citric acid.Compared with the control,the increased amounts of hydrogen peroxide(H2O2) and hydroxyl radical( ·OH ) induced the synthesis of CAT after an addition of citric acid to the culture medium. This conclusion was further confirmed by the addition of exogenous reactive oxygen(produced by menadione and paraquat) to the culture media.

  2. Evaluation of trans-1-amino-3-18F-fluorocyclobutanecarboxylic acid accumulation in low-grade glioma in chemically induced rat models: PET and autoradiography compared with morphological images and histopathological findings

    Introduction: Magnetic resonance imaging (MRI) can have a problem to delineate diffuse gliomas with an intact blood–brain barrier (BBB) especially when a marked peritumoral edema is present. We evaluated the potential of trans-1-amino-3-18F-fluorocyclobutanecarboxylic acid (anti-18F-FACBC) positron emission tomography (PET) to delineate the extent of diffuse gliomas by comparing PET findings with autoradiography, in vivo and ex vivo MRI, and histopathology findings. Methods: Dynamic PET was performed in rats with N-ethyl-N-nitrosourea-induced glioma for 60 min after anti-18F-FACBC injection. Contrast-enhanced MRI was performed before or after PET. The PET images were fused with in vivo and ex vivo MR images, and histopathological images for direct comparisons. Autoradiograms were compared with the results of Evans Blue (EB) extravasation (to assess BBB integrity) and hematoxylin-eosin staining. Results: Histopathological examination, including EB extravasation assessment, and enhanced T1-weighted MRI identified several diffuse gliomas with slight BBB disruption, similar to low-grade human gliomas. Anti-18F-FACBC uptake was specific and high in the gliomas, irrespective of BBB integrity. Higher anti-18F-FACBC uptake corresponded to areas of T2 hyperintensity, independent of gadolinium enhancement. Ex vivo autoradiography also showed high anti-18F-FACBC accumulation in tumors lacking EB extravasation and a correlation between anti-18F-FACBC accumulation and tumor cell density, but not EB extravasation. Conclusions: Anti-18F-FACBC-PET allowed visualization of gliomas irrespective of BBB integrity. The tumor-to-normal uptake ratio of anti-18F-FACBC generally correlated with the relative cell density. Anti-18F-FACBC PET combined with MRI shows promise for preoperative glioma delineation. Advances in knowledge: Radiopharmaceuticals that cross the BBB, such as anti-18F-FACBC, are taken up by low-grade gliomas with equivocal MRI findings due to an intact BBB

  3. Topically applied ceramide accumulates in skin glyphs

    Zhang Q

    2015-07-01

    Full Text Available Qihong Zhang,1 Carol R Flach,1 Richard Mendelsohn,1 Guangru Mao,2 Apostolos Pappas,2 M Catherine Mack,2 Russel M Walters,2 Michael D Southall2 1Department of Chemistry, Rutgers University, Newark, 2Johnson & Johnson Consumer Companies, Inc., Skillman, NJ, USAAbstract: Ceramides (CERs, structural components of the stratum corneum (SC, impart essential barrier properties to this thin outer layer of the epidermis. Variations in CER species within this layer have been linked to several skin diseases. A recent proliferation of CER-containing topical skin-care products warrants the elucidation of CER penetration profiles in both healthy and diseased skin. In the current study, the spatial distributions of CER concentration profiles, following topical application of two species of CER, were tracked using infrared imaging. Suspensions of single-chain perdeuterated sphingosine and phytosphingosine CER in oleic acid were applied, in separate experiments, to the surface of healthy intact ex vivo human skin using Franz diffusion cells. Following either a 24- or 48-hour incubation period at 34°C, infrared images were acquired from microtomed skin sections. Both CER species accumulated in glyph regions of the skin and penetrated into the SC, to a limited extent, only in these regions. The concentration profiles observed herein were independent of the CER species and incubation time utilized in the study. As a result, a very heterogeneous, sparse, spatial distribution of CERs in the SC was revealed. In contrast, oleic acid was found to be fairly homogeneously distributed throughout the SC and viable epidermis, albeit at lower concentrations in the latter. A more uniform, lateral distribution of CERs in the SC would likely be important for barrier efficacy or enhancement.Keywords: stratum corneum, infrared imaging, topical delivery, oleic acid

  4. High Systemic Exposure of Pyrazinoic Acid Has Limited Antituberculosis Activity in Murine and Rabbit Models of Tuberculosis.

    Lanoix, Jean-Philippe; Tasneen, Rokeya; O'Brien, Paul; Sarathy, Jansy; Safi, Hassan; Pinn, Michael; Alland, David; Dartois, Véronique; Nuermberger, Eric

    2016-07-01

    Pyrazinamide (PZA) is a prodrug requiring conversion to pyrazinoic acid (POA) by an amidase encoded by pncA for in vitro activity. Mutation of pncA is the most common cause of PZA resistance in clinical isolates. To determine whether the systemic delivery of POA or host-mediated conversion of PZA to POA could circumvent such resistance, we evaluated the efficacy of orally administered and host-derived POA in vivo Dose-ranging plasma and intrapulmonary POA pharmacokinetics and the efficacy of oral POA or PZA treatment against PZA-susceptible tuberculosis were determined in BALB/c and C3HeB/FeJ mice. The activity of host-derived POA was assessed in rabbits infected with a pncA-null mutant and treated with PZA. Median plasma POA values for the area under the concentration-time curve from 0 h to infinity (AUC0-∞) were 139 to 222 μg·h/ml and 178 to 287 μg·h/ml after doses of PZA and POA of 150 mg/kg of body weight, respectively, in mice. Epithelial lining fluid POA concentrations in infected mice were comparable after POA and PZA administration. In chronically infected BALB/c mice, PZA at 150 mg/kg reduced lung CFU counts by >2 log10 after 4 weeks. POA was effective only at 450 mg/kg, which reduced lung CFU counts by ∼0.7 log10 POA had no demonstrable bactericidal activity in C3HeB/FeJ mice, nor did PZA administered to rabbits infected with a PZA-resistant mutant. Oral POA administration and host-mediated conversion of PZA to POA producing plasma POA exposures comparable to PZA administration was significantly less effective than PZA. These results suggest that the intrabacillary delivery of POA and that producing higher POA concentrations at the site of infection will be more effective strategies for maximizing POA efficacy. PMID:27139472

  5. Copper extrusion after accumulation during growth of copper-tolerant yeast Yarrowia lipolytica

    Ito, Hiroyasu; Inouhe, Masahiro; Tohoyama, Hiroshi; Joho, Masanori [Ehime Univ., Matsuyama (Japan). Dept. of Biology

    2007-01-15

    The Cu{sup 2+}-tolerant yeast Yarrowia lipolytica accumulated Cu{sup 2+} until the late logarithmic phase. Thereafter, Cu{sup 2+} was temperature-dependently extruded into phosphate-limited culture medium containing high concentrations of heavy metal ions but not into 10 mm 2-(N-morpholino) ethane sulfonic acid (MES) buffer (pH 6.0). Peptone in the culture medium played an important role in the extrusion, which proceeded even when peptone was substituted with cysteine or histidine, but not with any other amino acid tested. (orig.)

  6. PNA-based DNA assay with attomolar detection limit based on polygalacturonic acid mediated in-situ deposition of metallic silver on a gold electrode

    An electrochemical method is described for the ultrasensitive determination of sequence-specific DNA by using polysaccharide-mediated in-situ deposition of metallic silver on a gold electrode. Specifically, a thiolated peptide nucleic acid (PNA) is immobilized on the gold electrode via formation of a self-assembled monolayer. Following hybridization between PNA and target single-stranded DNA (ssDNA), polygalacturonic acid (PGUA) is introduced to the PNA/DNA heteroduplexes via phosphate-zirconium-carboxylate coordination interaction. Next, the vicinal hydroxy groups of the polysaccharide backbone are cleaved and oxidized into aldehyde groups. These act as reductants and convert added silver ions into metallic silver which in-situ deposits on the gold electrode, and then is stripped off electrochemically into a solution of KCl where it is accurately determined by differential pulse voltammetry. Under optimal conditions, this assay exhibits a wide linear response range in that the stripping current is related to the logarithm of the concentration of target ssDNA in the 0.1 fM to 10 pM range, with a detection limit as low as 2.5 aM. The method displays excellent specificity in clearly differentiating mismatched oligonucleotide fragments. We therefore believe that this method has a large potential in terms of genotyping of single-nucleotide polymorphism. Moreover, this kind of signal amplification possesses a very large capability with respect to ultrasensitive quantitation of low-abundant biomarkers. (author)

  7. Nitrogen deficiency system is helpful in characterizing regulation mechanisms of ectopic triacylglycerol accumulation in Arabidopsis seedlings.

    Yang, Yang; Yu, Xiangchun; Song, Lianfen; An, Chengcai

    2011-12-01

    Triacylglycerol (TAG) is the major storage component accumulated in seed. However the regulatory mechanism of TAG synthesis and accumulation in non-seed tissues remains unknown. Recently, we found that nitrogen (N) deficiency (0.1mM N) caused an inducement of TAG biosynthesis in Arabidopsis seedlings. ABSCISIC ACID INSENSITIVE 4 (ABI4) was essential for the activation of Acyl-CoA:diacylglycerol acyltransferase1(DGAT1) expression during N deficiency in Arabidopsis seedlings. In this addendum, we further discussed the approaches to provide a net increase in total oil production in higher plants by using the low N platform. First, the N-deficient seedlings can be used to determine the key factors that regulate the ectopic expression of key genes in TAG metabolism. Second, the research on the relationship between TAG homeostasis and cell division will be helpful to find the key factors that specifically regulate TAG accumulation under the nutrient-limited condition. PMID:22112453

  8. Further improvement in ganoderic acid production in static liquid culture of Ganoderma lucidum by integrating nitrogen limitation and calcium ion addition.

    Li, Huan-Jun; Zhang, De-Huai; Han, Li-Liang; Yu, Xuya; Zhao, Peng; Li, Tao; Zhong, Jian-Jiang; Xu, Jun-Wei

    2016-01-01

    To further improve the ganoderic acid (GA) production, a novel integrated strategy by combining nitrogen limitation and calcium ion addition was developed. The effects of the integrated combination on the content of GA-T (one powerful anticancer compound), their intermediates (squalene and lanosterol) and on the transcription levels of GA biosynthetic genes in G. lucidum fermentation were investigated. The maximum GA-T content with the integrated strategy were 1.87 mg/ 100 mg dry cell weight, which was 2.1-4.2 fold higher than that obtained with either calcium ion addition or nitrogen limitation alone, and it is also the highest record as ever reported in submerged fermentation of G. lucidum. The squalene content was increased by 3.9- and 2.2-fold in this case compared with either individual strategy alone. Moreover, the transcription levels of the GA biosynthetic genes encoding 3-hydroxy-3-methyglutaryl coenzyme A reductase and lanosterol synthase were also up-regulated by 3.3-7.5 and 1.3-2.3 fold, respectively. PMID:26508324

  9. Plastids and Carotenoid Accumulation.

    Li, Li; Yuan, Hui; Zeng, Yunliu; Xu, Qiang

    2016-01-01

    Plastids are ubiquitously present in plants and are the organelles for carotenoid biosynthesis and storage. Based on their morphology and function, plastids are classified into various types, i.e. proplastids, etioplasts, chloroplasts, amyloplasts, and chromoplasts. All plastids, except proplastids, can synthesize carotenoids. However, plastid types have a profound effect on carotenoid accumulation and stability. In this chapter, we discuss carotenoid biosynthesis and regulation in various plastids with a focus on carotenoids in chromoplasts. Plastid transition related to carotenoid biosynthesis and the different capacity of various plastids to sequester carotenoids and the associated effect on carotenoid stability are described in light of carotenoid accumulation in plants. PMID:27485226

  10. Mesenchymal Stromal Cells Differentiating to Adipocytes Accumulate Autophagic Vesicles Instead of Functional Lipid Droplets.

    Gruia, Alexandra T; Suciu, Maria; Barbu-Tudoran, Lucian; Azghadi, Seyed Mohammad Reza; Cristea, Mirabela I; Nica, Dragos V; Vaduva, Adrian; Muntean, Danina; Mic, Ani Aurora; Mic, Felix A

    2016-04-01

    Adult bone marrow mesenchymal stromal cells (BMSCs) can easily be differentiated into a variety of cells. In vivo transplantation of BMSCs-differentiated cells has had limited success, suggesting that these cells may not be fully compatible with the cells they are intended to replace in vivo. We investigated the structural and functional features of BMSCs-derived adipocytes as compared with adipocytes from adipose tissue, and the structure and functionality of lipid vesicles formed during BMSCs differentiation to adipocytes. Gas chromatography-mass spectrometry showed fatty acid composition of BMSCs-derived adipocytes and adipocytes from the adipose tissue to be very different, as is the lipid rafts composition, caveolin-1 expression, caveolae distribution in their membranes, and the pattern of expression of fatty acid elongases. Confocal microscopy confirmed the absence from BMSCs-derived adipocytes of markers of lipid droplets. BMSCs-derived adipocytes cannot convert deuterated glucose into deuterated species of fatty acids and cannot uptake the deuterated fatty acid-bovine serum albumin complexes from the culture medium, suggesting that intra-cellular accumulation of lipids does not occur by lipogenesis. We noted that BMSCs differentiation to adipocytes is accompanied by an increase in autophagy. Autophagic vesicles accumulate in the cytoplasm of BMSCs-derived adipocytes and their size and distribution resembles that of Nile Red-stained lipid vesicles. Stimulation of autophagy in BMSCs triggers the intra-cellular accumulation of lipids, while inhibition of autophagy prevents this accumulation. In conclusion, differentiation of BMSCs-derived adipocytes leads to intra-cellular accumulation of autophagic vesicles rather than functional lipid droplets, suggesting that these cells are not authentic adipocytes. J. Cell. Physiol. 231: 863-875, 2016. © 2015 Wiley Periodicals, Inc. PMID:26332160

  11. Biotechnological production of citric acid

    Belén Max

    2010-12-01

    Full Text Available This work provides a review about the biotechnological production of citric acid starting from the physicochemical properties and industrial applications, mainly in the food and pharmaceutical sectors. Several factors affecting citric acid fermentation are discussed, including carbon source, nitrogen and phosphate limitations, pH of culture medium, aeration, trace elements and morphology of the fungus. Special attention is paid to the fundamentals of biochemistry and accumulation of citric acid. Technologies employed at industrial scale such as surface or submerged cultures, mainly employing Aspergillus niger, and processes carried out with Yarrowia lipolytica, as well as the technology for recovering the product are also described. Finally, this review summarizes the use of orange peels and other by-products as feedstocks for the bioproduction of citric acid.

  12. Chimpanzee accumulative stone throwing.

    Kühl, Hjalmar S; Kalan, Ammie K; Arandjelovic, Mimi; Aubert, Floris; D'Auvergne, Lucy; Goedmakers, Annemarie; Jones, Sorrel; Kehoe, Laura; Regnaut, Sebastien; Tickle, Alexander; Ton, Els; van Schijndel, Joost; Abwe, Ekwoge E; Angedakin, Samuel; Agbor, Anthony; Ayimisin, Emmanuel Ayuk; Bailey, Emma; Bessone, Mattia; Bonnet, Matthieu; Brazolla, Gregory; Buh, Valentine Ebua; Chancellor, Rebecca; Cipoletta, Chloe; Cohen, Heather; Corogenes, Katherine; Coupland, Charlotte; Curran, Bryan; Deschner, Tobias; Dierks, Karsten; Dieguez, Paula; Dilambaka, Emmanuel; Diotoh, Orume; Dowd, Dervla; Dunn, Andrew; Eshuis, Henk; Fernandez, Rumen; Ginath, Yisa; Hart, John; Hedwig, Daniela; Ter Heegde, Martijn; Hicks, Thurston Cleveland; Imong, Inaoyom; Jeffery, Kathryn J; Junker, Jessica; Kadam, Parag; Kambi, Mohamed; Kienast, Ivonne; Kujirakwinja, Deo; Langergraber, Kevin; Lapeyre, Vincent; Lapuente, Juan; Lee, Kevin; Leinert, Vera; Meier, Amelia; Maretti, Giovanna; Marrocoli, Sergio; Mbi, Tanyi Julius; Mihindou, Vianet; Moebius, Yasmin; Morgan, David; Morgan, Bethan; Mulindahabi, Felix; Murai, Mizuki; Niyigabae, Protais; Normand, Emma; Ntare, Nicolas; Ormsby, Lucy Jayne; Piel, Alex; Pruetz, Jill; Rundus, Aaron; Sanz, Crickette; Sommer, Volker; Stewart, Fiona; Tagg, Nikki; Vanleeuwe, Hilde; Vergnes, Virginie; Willie, Jacob; Wittig, Roman M; Zuberbuehler, Klaus; Boesch, Christophe

    2016-01-01

    The study of the archaeological remains of fossil hominins must rely on reconstructions to elucidate the behaviour that may have resulted in particular stone tools and their accumulation. Comparatively, stone tool use among living primates has illuminated behaviours that are also amenable to archaeological examination, permitting direct observations of the behaviour leading to artefacts and their assemblages to be incorporated. Here, we describe newly discovered stone tool-use behaviour and stone accumulation sites in wild chimpanzees reminiscent of human cairns. In addition to data from 17 mid- to long-term chimpanzee research sites, we sampled a further 34 Pan troglodytes communities. We found four populations in West Africa where chimpanzees habitually bang and throw rocks against trees, or toss them into tree cavities, resulting in conspicuous stone accumulations at these sites. This represents the first record of repeated observations of individual chimpanzees exhibiting stone tool use for a purpose other than extractive foraging at what appear to be targeted trees. The ritualized behavioural display and collection of artefacts at particular locations observed in chimpanzee accumulative stone throwing may have implications for the inferences that can be drawn from archaeological stone assemblages and the origins of ritual sites. PMID:26923684

  13. Culture Conditions stimulating high γ-Linolenic Acid accumulation by Spirulina platensis Condições de cultura simulando o levado acúmulo de ácido γ-linolênico por Spirulina platensis

    Srinivasa Reddy Ronda; S. S. Lele

    2008-01-01

    Gamma-linolenic acid (GLA) production by Spirulina platensis under different stress-inducing conditions was studied. Submerged culture studies showed that low temperature (25ºC), strong light intensity (6 klux) and primrose oil supplement (0.8%w/v) induced 13.2 mg/g, 14.6 mg/g and 13.5 mg linolenic acid per gram dry cell weight respectively. A careful observation of fatty acid profile of the cyanobacteria shows that, oleic acid and linoleic acid, in experiments with varying growth temperature...

  14. Evaluating the role of conserved amino acids in bacterial O-oligosaccharyltransferases by in vivo, in vitro and limited proteolysis assays.

    Musumeci, Matias A; Faridmoayer, Amirreza; Watanabe, Yasuharu; Feldman, Mario F

    2014-01-01

    Bacterial O-Oligosaccharyltransferases (O-OTases) constitute a growing family of enzymes that catalyze the transfer of a glycan from a lipid carrier to protein acceptors. O-OTases are inner membrane proteins that display limited sequence similarity, except for the Wzy_C signature domain also present in a predicted periplasmic loop of the WaaL ligase, the enzyme responsible for transferring the O antigen to the lipid A core. The mechanism of O-OTase-dependent glycosylation is poorly understood. In this work, conserved amino acid residues in the O-OTases were replaced with alanine in PglL, the O-OTase of Neisseria meningitidis. The activity of wild-type PglL and its mutant derivatives were analyzed in vivo in engineered Escherichia coli cells, and in in vitro assays. We identified two additional sites of pilin glycosylated exclusively by PglL in E. coli. Both sites are modified with phosphoglycerol (PG) by different enzymes in Neisseria gonorrhoeae and Neisseria meningitidis. Limited proteolysis experiments revealed a conformational change that is triggered upon interaction of the C-terminal region of PglL with the lipid-linked oligosaccharide (LLO) substrate. These experiments showed that Q178 and Y405 are required for optimal function, whereas H349 is essential for activity and plays a critical role in the interaction with LLO. The equivalent His residue is also essential for WaaL activity, which suggests a common mechanism for both enzymes, and supports the hypothesis that O-glycosylation and lipopolysaccharide (LPS) synthesis are evolutionarily related. These results contribute to the elucidation of the mechanism of O-OTases, which are promising targets for novel antibiotics and present an enormous potential for glycoengineering novel vaccines and therapeutics. PMID:24092836

  15. Impact of nitrous acid photolysis on the total hydroxyl radical budget during the Limitation of Oxidant Production/Pianura Padana Produzione di Ozono study in Milan

    Alicke, B.; Platt, U.; Stutz, J.

    2002-11-01

    The photolysis of nitrous acid (HONO) in the early morning hours is believed to be a significant source of hydroxyl radicals (OH), the most important daytime oxidizing species. Although the importance of this mechanism has been recognized for many years, no accurate experimental quantification is available. Here we present measurements of HONO, NO2, SO2, O3 and HCHO by Differential Optical Absorption Spectroscopy (DOAS) during the Limitation of Oxidant Production/Pianura Padana Produzione di Ozono (LOOP/PIPAPO) study in May-June 1998 in Milan, Italy. The concentration of NO and J(NO2)/J(HONO) were simultaneously monitored by in situ monitors. The photolysis frequencies of HCHO and O3 were determined with a radiative transfer model. High nocturnal HONO mixing ratios of up to 4.4 ppb were regularly observed. Elevated daytime HONO levels during cloudy periods show that the formation of HONO proceeds after sunrise and therefore also represents a source of hydroxyl radicals throughout the day. Averaged over 24 hours, HCHO photolysis is the most important source of OH in Milan, followed by either ozone or HONO photolysis. Our observations indicate that on certain days the OH production from HONO can be even more important than that from ozone photolysis. The diurnal variation of the different OH formation mechanisms shows that HONO photolysis is by far the most important source in the early hours of the morning, and can be as large as and even surpass the total OH production at noon.

  16. Limited effect of reactive oxygen species on the composition of susceptible essential amino acids in the midguts of Lymantria dispar caterpillars.

    Barbehenn, Raymond V; Niewiadomski, Julie; Kochmanski, Joseph; Constabel, C Peter

    2012-11-01

    The essential amino acids (EAAs) arginine, histidine, lysine, and methionine, as well as cysteine (semiessential), are believed to be susceptible to reactions with reactive oxygen species (ROS) in biological systems. The decreased availability of these EAAs could harm insect nutrition, since several of them can also be limiting for protein synthesis. However, no in vivo studies have quantified the effect of ROS in the midguts of insect herbivores on EAA composition. This study examined the association between elevated levels of ROS in the midgut fluid of Lymantria dispar caterpillars and the compositions of EAAs (protein-bound + protein-free) in their midgut fluid and frass. Contrary to expectation, the compositions of EAAs were not significantly decreased by ROS in midgut fluid ex vivo when incubated with phenolic compounds. Two in vivo comparisons of low- and high-ROS-producing leaves also showed similar results: there were no significant decreases in the compositions of EAAs in the midgut fluids and/or frass of larvae with elevated levels of ROS in their midguts. In addition, waste nitrogen excretion was not significantly increased from larvae on high-ROS treatments, as would be expected if ROS produced unbalanced EAA compositions. These results suggest that L. dispar larvae are able to tolerate elevated levels of ROS in their midguts without nutritionally significant changes in the compositions of susceptible EAAs in their food. PMID:22961657

  17. Antiproton Accumulator (AA)

    Photographic Service

    1980-01-01

    The AA in its final stage of construction, before it disappeared from view under concrete shielding. Antiprotons were first injected, stochastically cooled and accumulated in July 1980. From 1981 on, the AA provided antiprotons for collisions with protons, first in the ISR, then in the SPS Collider. From 1983 on, it also sent antiprotons, via the PS, to the Low-Energy Antiproton Ring (LEAR). The AA was dismantled in 1997 and shipped to Japan.

  18. Accumulation of satellites

    Formation and evolution of circumplanetary satellite swarms are investigated. Characteristic times of various processes are estimated. The characteristic time for the accumulation of the bodies in the swarm was several orders of magnitude shorter than that of the planet, i.e. than the time of the replenishment of the material by the swarm (108 yr). The model of the accumulation of the swarm is constructed taking into account the increase of its mass due to trapping of heliocentrically moving particles and its decrease due to outfall of the inner part of the swarm onto the growing planet. The accumulation of circumplanetary bodies is also considered. The main features of the evolution of the swarm essentially depend on the size distribution of bodies in the swarm and in the zone of the planet and also on the degree of the concentration of the swarm mass toward the planet. If the sum of the exponents of the inverse power laws of these distributions is less than 7, the model of the transparent swarm developed in this paper should be preferred. When this sum is greater than 7, the model of opaque swarm suggested by A. Harris and W.M. Kaula is better. There is predominant trapping of small particles into the swarm due to their more frequent collisions. Optical thickness of the protoplanetary cloud in radial direction is estimated. It is shown that at the final stage of the planetary accumulation, the cloud was semitransparent in the region of terrestrial planets and volatile substances evaporated at collisions could be swept out from the outer parts of the satellite swarm by the solar wind

  19. Information Accumulation in Development

    Acemoglu, Daron; Zilibotti, Fabrizio

    1998-01-01

    We propose a model in which economic relations and institutions in advanced and less developed countires differ as these societies have access to different amounts of information. The lack of information in less developped economies makes it hard to evaluate the performance of managers, and leads to high "agency costs". Differencies in the amount of information have a variety of sources. As well as factors related to the informational infrastructure, we emphasize that societies accumulate inf...

  20. Chimpanzee accumulative stone throwing

    Hjalmar S Kühl; Kalan, Ammie K.; Mimi Arandjelovic; Floris Aubert; Lucy D’Auvergne; Annemarie Goedmakers; Sorrel Jones; Laura Kehoe; Sebastien Regnaut; Alexander Tickle; Els Ton; Joost van Schijndel; Abwe, Ekwoge E; Samuel Angedakin; Anthony Agbor

    2016-01-01

    The authors would like to thank the Max Planck Society and Krekeler Foundation for generous funding of the Pan African Programme. The study of the archaeological remains of fossil hominins must rely on reconstructions to elucidate the behaviour that may have resulted in particular stone tools and their accumulation. Comparatively, stone tool use among living primates has illuminated behaviours that are also amenable to archaeological examination, permitting direct observations of the behav...

  1. New yeast-based approaches in production of palmitoleic acid.

    Kolouchová, Irena; Sigler, Karel; Schreiberová, Olga; Masák, Jan; Řezanka, Tomáš

    2015-09-01

    Palmitoleic acid is found in certain dairy products and has broad applications in medicine and cosmetics. We tried to find a suitable producer of this acid among traditional biotechnological yeast species (Kluyveromyces polysporus, Torulaspora delbrueckii, Saccharomyces cerevisiae) characterized by high biomass yield and Candida krusei, Yarrowia lipolytica and Trichosporon cutaneum accumulating large amounts of lipids. The main factor affecting the content of palmitoleic acid was found to be the C/N ratio in the culture medium, with ammonium sulfate as an optimum nitrogen source leading to highest biomass yield with concomitantly increased lipid accumulation, and an increased content of ω6-linoleic acid, the precursor of prostaglandins, leukotrienes, and thromboxanes. We found that C. krusei can be conveniently used for the purpose, albeit only under certain cultivation conditions, whereas S. cerevisiae can produce high and stable amounts of palmitoleic acid in a broad range of cultivation conditions ranging from conventional to nutrient limitations. PMID:26101962

  2. Comparison of the frequency of functional SH3 domains with different limited sets of amino acids using mRNA display.

    Junko Tanaka

    Full Text Available Although modern proteins consist of 20 different amino acids, it has been proposed that primordial proteins consisted of a small set of amino acids, and additional amino acids have gradually been recruited into the genetic code. This hypothesis has recently been supported by comparative genome sequence analysis, but no direct experimental approach has been reported. Here, we utilized a novel experimental approach to test a hypothesis that native-like globular proteins might be easily simplified by a set of putative primitive amino acids with retention of its structure and function than by a set of putative new amino acids. We performed in vitro selection of a functional SH3 domain as a model from partially randomized libraries with different sets of amino acids using mRNA display. Consequently, a library rich in putative primitive amino acids included a larger number of functional SH3 sequences than a library rich in putative new amino acids. Further, the functional SH3 sequences were enriched from the primitive library slightly earlier than from a randomized library with the full set of amino acids, while the function and structure of the selected SH3 proteins with the primitive alphabet were comparable with those from the 20 amino acid alphabet. Application of this approach to various combinations of codons in protein sequences may be useful not only for clarifying the precise order of the amino acid expansion in the early stages of protein evolution but also for efficiently creating novel functional proteins in the laboratory.

  3. Electron-Positron Accumulator (EPA)

    Photographic Service

    1986-01-01

    After acceleration in the low-current linac LIL-W, the electrons and positrons are accumulated in EPA to obtain a sufficient intensity and a suitable time-structure, before being passed on to the PS for further acceleration to 3.5 GeV. Electrons circulate from right to left, positrons in the other direction. Dipole bending magnets are red, focusing quadrupoles blue, sextupoles for chromaticity-control orange. The vertical tube at the left of the picture belongs to an optical transport system carrying the synchrotron radiation to detectors for beam size measurement. Construction of EPA was completed in spring 1986. LIL-W and EPA were conceived for an energy of 600 MeV, but operation was limited to 500 MeV.

  4. Production of polyhydroxyalkanoates by glycogen accumulating organisms treating a paper mill wastewater.

    Bengtsson, Simon; Werker, Alan; Welander, Thomas

    2008-01-01

    A process for production of polyhydroxyalkanoates (PHA) by activated sludge treating a paper mill wastewater was investigated. The applied strategy was to select for glycogen accumulating organisms (GAOs) by alternating anaerobic/aerobic conditions. Acidogenic fermentation was used as pretreatment to convert various organic compounds to volatile fatty acids which are preferable substrates for PHA production. Enrichment resulted in a culture dominated by GAOs related to Defluviicoccus vanus (56%) and Candidatus Competibacter phosphatis (22%). Optimization of PHA accumulation by the enriched GAO culture was performed through batch experiments. Accumulation of PHA under anaerobic conditions was limited by the intracellular glycogen stored. Under aerobic conditions significant glycogen production (to 25% of sludge dry weight) was observed alongside PHA accumulation (to 22% of sludge dry weight). By applying a subsequent anaerobic period after an initial aerobic, the produced glycogen could be utilized for further PHA accumulation and by this strategy PHA content was increased to 42% of sludge dry weight. The PHA yield over the entire process was 0.10 kg per kg of influent COD treated which is similar to what has been achieved with a process applying feast/famine enrichment strategy with the same wastewater. PMID:18701781

  5. The release of dipicolinic acid--the rate-limiting step of Bacillus endospore inactivation during the high pressure thermal sterilization process.

    Reineke, Kai; Schlumbach, Karl; Baier, Daniel; Mathys, Alexander; Knorr, Dietrich

    2013-03-01

    High pressure combined with elevated temperatures can produce low acid, commercially sterile and shelf-stable foods. Depending on the temperature and pressure levels applied, bacterial endospores pass through different pathways, which can lead to a pressure-induced germination or inactivation. Regardless of the pathway, Bacillus endospores first release pyridine-2,6-dicarboxylic acid (DPA), which contributes to the low amount of free water in the spore core and is consequently responsible for the spore's high resistance against wet and dry heat. This is therefore the rate-limiting step in the high pressure sterilization process. To evaluate the impact of a broad pressure, temperature and time domain on the DPA release, Bacillus subtilis spores were pressure treated between 0.1 and 900 MPa at between 30 and 80 °C under isothermal isobaric conditions during dwell time. DPA quantification was assessed using HPLC, and samples were taken both immediately and 2 h after the pressure treatment. To obtain a release kinetic for some pressure-temperature conditions, samples were collected between 1s and 60 min after decompression. A multiresponse kinetic model was then used to derive a model covering all kinetic data. The isorate lines modeled for the DPA release in the chosen pressure-temperature landscape enabled the determination of three distinct zones. (I) For pressures temperatures >50 °C, a 90% DPA release was achievable in less than 5 min and no difference in the amount of DPA was found immediately 2 h after pressurization. This may indicate irreversible damage to the inner spore membrane or membrane proteins. (II) Above 600 MPa the synergism between pressure and temperature diminished, and the treatment temperature alone dominated DPA release. (III) Pressures temperatures <50 °C resulted in a retarded release of DPA, with strong increased differences in the amount of DPA released after 2 h, which implies a pressure-induced physiological like germination with

  6. Assimilate transfer and accumulation with in the maize pedicel

    This study was conducted to characterize assimilate transfer through the pedicel of the maize (Zea mays L.) kernel and assess this transfer process as a possible limitation to kernel dry matter accumulation. Sugar, amino acid, and 14C-assimilate unloading from the pedicel were studied following removal of the endosperm and embryo. Unloading was not affected by potassium or a 10-min treatment with p-chloromercuribenzene sulfonic acid (PCMBS), a slowly penetrating sulfhydryl group inhibitor. These observations are consistent with the recent hypothesis of passive assimilate unloading from the pedicel cells, followed by uptake into the endosperm. Sugar content of the pedicel parenchyma-placento-chalazal tissue (PPPC) of the maize kernel was measured following light periods of varying duration and following source-sink manipulation. Source-sink ratio manipulation, imposed by partial defoliation and ear removal at 12 d postpollination, did not influence PPPC sugar content 10 d after treatment. PPPC sugar content was 16-21% higher in the afternoon than in the morning. Using compartmental analysis techniques, it was determined that fluctuations in PPPC sugar content occurred primarily within the free space. These observations support the hypothesis that assimilate uptake into the endosperm, rather unloading from the pedicel, is a rate-limiting transfer process. Source-sink manipulation affected kernel number per ear, kernel weight, kernel growth rate, and stalk dry weight. On a long-term basis, PPPC sugar content was maintained at relatively constant levels by changes in kernel growth patterns, assimilate partitioning, and remobilization

  7. Effect of Phytase Superdoses and Citric Acid on Growth Performance, Plasma Phosphorus and Tibia Ash in Broilers Fed Canola Meal-Based Diets Severely Limited in Available Phosphorus

    Taheri HR

    2015-06-01

    Full Text Available This experiment was conducted to investigate the effect of phytase superdoses alone or in combination with citric acid (CA in canola meal-based diets severely limited in available phosphorus (Pa on growth performance, plasma phosphorus (P, and tibia ash (TA in broilers from 22 to 42 d of age. Two hundreds and eighty 21-d-old male broilers were used in 28 pens of 10 birds per each. The experimental diets consisted of a positive control (PC diet and six negative control (NC diets which consisted of two levels of CA (0 and 20 g/Kg and three levels of phytase (0, 1000 and 4000 U/Kg in a 2 × 3 factorial arrangement. The PC diet contained 4.3 g/Kg Pa, but all NC diets contained 1.5 g/Kg Pa. Results indicated that the birds fed the PC diet had a significantly higher average daily gain (ADG, plasma P and TA, but a lower feed conversion ratio (FCR than those fed the NC diet. The ADG, FCR and plasma P values in birds fed NC diets supplemented with 4000 U/Kg phytase enzyme (with or without CA significantly reached those of birds fed the PC diet. But, addition of phytase enzyme at 1000 U/Kg only plus CA to the NC diet could significantly improve FCR and plasma P. A significant interaction was observed between phytase and CA for FCR and plasma P. Although TA values in NC + 1000 U/Kg phytase treatments (with or without CA were similar to the PC treatment, TA values of NC + 4000 U/Kg phytase treatments (with or without CA was greater than that of the PC treatment. Results of this study showed that, in severely limited Pa corn-canola meal-based diets, supplementing 4000 U/Kg phytase or also 1000 U/Kg phytase plus CA will be sufficient to obtain the comparable feed efficiency in broilers to those fed the adequate Pa diet.

  8. A Case-Control Study between Gene Polymorphisms of Polyunsaturated Fatty Acid Metabolic Rate-Limiting Enzymes and Acute Coronary Syndrome in Chinese Han Population

    Zikai Song; Hongyan Cao; Ling Qin; Yanfang Jiang

    2013-01-01

    The purpose of this study is to analyze the relationship between the polymorphisms of fatty acid desaturase 1 (FADS1), fatty acid desaturase 2 (FADS2), and elongation of very long-chain fatty acids-like 2 (ELOVL2) and acute coronary syndrome (ACS) in Chinese Han population. Therefore, we selected three single nucleotide polymorphisms (SNPs) from these candidate genes and genotyped them using PCR-based restriction fragment length polymorphism analysis in 249 ACS patients and 240 non-ACS subjec...

  9. Ice slurry accumulation

    Christensen, K.G.; Kauffeld, M.

    1998-06-01

    More and more refrigeration systems are designed with secondary loops, thus reducing the refrigerant charge of the primary refrigeration plant. In order not to increase energy consumption by introducing a secondary refrigerant, alternatives to the well established single phase coolants (brines) and different concepts of the cooling plant have to be evaluated. Combining the use of ice-slurry - mixture of water, a freezing point depressing agent (antifreeze) and ice particles - as melting secondary refrigerant and the use of a cool storage makes it possible to build plants with secondary loops without increasing the energy consumption and investment. At the same time the operating costs can be kept at a lower level. The accumulation of ice-slurry is compared with other and more traditional storage systems. The method is evaluated and the potential in different applications is estimated. Aspects of practically use of ice-slurry has been examined in the laboratory at the Danish Technological Institute (DTI). This paper will include the final conclusions from this work concerning tank construction, agitator system, inlet, outlet and control. The work at DTI indicates that in some applications systems with ice-slurry and accumulation tanks have a great future. These applications are described by a varying load profile and a process temperature suiting the temperature of ice-slurry (-3 - -8/deg. C). (au)

  10. Reactive oxygen species and autophagy associated apoptosis and limitation of clonogenic survival induced by zoledronic acid in salivary adenoid cystic carcinoma cell line SACC-83.

    Xi-Yuan Ge

    Full Text Available Salivary adenoid cystic carcinoma is an epithelial tumor in the head and neck region. Despite its slow growth, patients with salivary adenoid cystic carcinoma exhibit poor long term survival because of a high rate of distant metastasis. Lung and bone are common distant metastasis sites. Zoledronic acid, a third generation bisphosphonate, has been used for tumor-induced osteolysis due to bone metastasis and has direct antitumor activity in several human neoplasms. Here, we observed that zoledronic acid inhibited salivary adenoid cystic carcinoma cell line SACC-83 xenograft tumor growth in nude mice. In vitro, zoledronic acid induced apoptosis and reduced clonogenic survival in SACC-83. Flow cytometry and western blotting indicated that the cell cycle was arrested at G0/G1. Zoledronic acid treatment upregulated reactive oxygen species as well as the autophagy marker protein LC-3B. Reactive oxygen species scavenger N-acetylcysteine and autophagy antagonist 3-methyladenine decreased zoledronic acid-induced apoptosis and increased clonogenic survival. Silencing of the autophagy related gene Beclin-1 also decreased zoledronic acid-induced apoptosis and inhibition of clonogenic formation. In addition, isobolographic analysis revealed synergistic effects on apoptosis when zoledronic acid and paclitaxel/cisplatin were combined. Taken together, our results suggest that zoledronic acid induced apoptosis and reduced clonogenic survival via upregulation of reactive oxygen species and autophagy in the SACC-83 cell line. Thus, zoledronic acid should be considered a promising drug for the treatment of salivary adenoid cystic carcinoma.

  11. Effect of natural saline soil on organic acid accumulation in the stem and leaf of Chloris virgata and analysis of stress factors%天然盐碱土壤对虎尾草茎叶有机酸积累影响及胁迫因子分析

    吕家强; 李长有; 杨春武; 胡锐

    2015-01-01

    虎尾草是一种耐盐碱性很强的天然牧草,在吉林省长岭县盐碱化草地上随机选择45个虎尾草天然种群样点,测量每个样点的土壤电导率、pH、缓冲量3个因素作为反映土壤盐碱化程度的胁迫强度指标,在每个样点上测量虎尾草茎叶中有机酸含量作为反映植物生理响应的胁变指标,进行回归分析。结果表明:虎尾草茎叶大量积累柠檬酸、苹果酸、草酸以及总有机酸以响应强盐碱胁迫且与三胁迫因素呈显著正相关,仅积累量较低的琥珀酸相反。多元回归分析发现土壤电导率对除了琥珀酸之外的其他有机酸积累影响最大,电导率可以作为天然盐碱化土壤环境下考察虎尾草响应盐碱胁迫的主要胁迫因素。%Chloris virgata is a native forage grass with strong salt-alkali resistance.Samples of 45 natural popu-lations of C.virgata were randomly chosen from the saline meadows in Changling County,Jilin Province.Soil electrical conductivity,pH and buffering capacity were measured in each sample area to assess the degree of soil salinization and associated plant stress.Organic acid contents in C.virgata stems and leaves were measured as plant physiological response indexes.A regression analysis was conducted incorporating incorporating both plant and soil data.C.virgata accumulated large amounts of organic acids including citric acid,malic acid and oxalic acid in response to strong salt-alkali stress,and there was a significantly positive correlation between the accumulation of citric acid,malic acid,oxalic acid and total organic acids and the three soil indexes.By con-trast,the level of amber acid was less under saline stress and was negatively correlated with the three soil inde-xes.Further multiple regression analysis showed that soil electrical conductivity was more strongly correlated with the accumulation of the plant organic acids (except succinic acid)than pH and buffering capacity.In con

  12. Global southern limit of flowering plants and moss peat accumulation

    Convey, Peter; Hopkins, David W.; Roberts, Stephen J.; Tyler, Andrew N.

    2011-01-01

    The ecosystems of the western Antarctic Peninsula, experiencing amongst the most rapid trends of regional climate warming worldwide, are important “early warning” indicators for responses expected in more complex systems elsewhere. Central among responses attributed to this regional warming are widely reported population and range expansions of the two native Antarctic flowering plants, Deschampsia antarctica and Colobanthus quitensis. However, confirmation of the predictions of range expansi...

  13. Quantum gravity and inventory accumulation

    Sheffield, Scott

    2011-01-01

    We begin by studying inventory accumulation at a LIFO (last-in-first-out) retailer with two products. In the simplest version, the following occur with equal probability at each time step: first product ordered, first product produced, second product ordered, second product produced. The inventory thus evolves as a simple random walk on Z^2. In more interesting versions, a p fraction of customers orders the "freshest available" product regardless of type. We show that the corresponding random walks scale to Brownian motions with diffusion matrices depending on p. We then turn our attention to the critical Fortuin-Kastelyn random planar map model, which gives, for each q>0, a probability measure on random (discretized) two-dimensional surfaces decorated by loops, related to the q-state Potts model. A longstanding open problem is to show that as the discretization gets finer, the surfaces converge in law to a limiting (loop-decorated) random surface. The limit is expected to be a Liouville quantum gravity surfa...

  14. 草甘膦对耐草甘膦大豆体内莽草酸含量及产量的影响%Shikimic Acid Accumulation as an Indicator of Glyphosate Tolerance in Glyphosate-Resistant Soybean

    杨鑫浩; 李香菊

    2014-01-01

    采用网室盆栽试验与田间试验相结合的方法,测定处于不同叶龄的大豆在草甘膦处理后莽草酸的积累量。结果表明:1230~2460 g a.i./hm2草甘膦处理后,常规大豆莽草酸积累量急剧上升,并随草甘膦处理剂量的增加而升高。耐草甘膦大豆莽草酸积累量与不用药的空白对照差异不显著;在4920 g a.i./hm2草甘膦处理后,体内莽草酸出现短时间的积累,但5~9d后恢复至药前水平。在3、5、7张羽状三出复叶期喷施草甘膦后,不同叶龄之间的大豆叶片莽草酸积累量差异不显著,说明这3个叶龄处理的耐草甘膦大豆均有较好的耐受性。上述草甘膦处理剂量及处理时期施药后,耐草甘膦大豆籽粒产量与不用药的空白对照差异不显著。%Pot experiments and field trials were conducted to determine the shikimate accumulation after glyphosate appli -cation during the period of soybean growth .At 1 230.0~2 460.0 g a.i./hm2,shikimate accumulation rapidly increased in leaves of conventional soybean .Accumulation increased with increasing herbicide doses .Shikimate accumulation in glyphosate-resistant soybean did not differ between glyphosate -applied and blank control treatments .Shikimate accu-mulation did not differ among glyphosate -resistant crop plants treated with glyphostate at the 3 -,5 -and 7 -leaf growth stages,which indicates that transgenic soybeans at those growth stages expressed high tolerance to glyphosate .At 4 920 g a.i./hm2 ,shikimate transiently accumulated but returned to its normal level before the glyphosate application after 5~9 days.The transgenic glyphosate -resistant soybean subjected to the above dosage of glyphosate produced the same yield as the blank control .Shikimate accumulation can be used as an early detection index of glyphosate tolerance levels of soybean .

  15. The Antiproton Accumulator (AA)

    1980-01-01

    Section 06 - 08*) of the AA where the dispersion (and hence the horizontal beam size) is large. One can distinguish (left to right): A vacuum-tank, two bending magnets (BST06 and BST07 in blue) with a quadrupole (QDN07, in red) in between, another vacuum-tank, a wide quadrupole (QFW08) and a further tank . The tanks are covered with heating tape for bake-out. The tank left of BST06 contained the stack core pickup for stochastic cooling (see 7906193, 7906190, 8005051), the two other tanks served mainly as vacuum chambers in the region where the beam was large. Peter Zettwoch works on BST06. *) see: H. Koziol, Antiproton Accumulator Parameter List, PS/AA/Note 84-2 (1984)

  16. Solids Accumulation Scouting Studies

    Duignan, M. R.; Steeper, T. J.; Steimke, J. L.

    2012-09-26

    The objective of Solids Accumulation activities was to perform scaled testing to understand the behavior of remaining solids in a Double Shell Tank (DST), specifically AW-105, at Hanford during multiple fill, mix, and transfer operations. It is important to know if fissionable materials can concentrate when waste is transferred from staging tanks prior to feeding waste treatment plants. Specifically, there is a concern that large, dense particles containing plutonium could accumulate in poorly mixed regions of a blend tank heel for tanks that employ mixing jet pumps. At the request of the DOE Hanford Tank Operations Contractor, Washington River Protection Solutions, the Engineering Development Laboratory of the Savannah River National Laboratory performed a scouting study in a 1/22-scale model of a waste staging tank to investigate this concern and to develop measurement techniques that could be applied in a more extensive study at a larger scale. Simulated waste tank solids: Gibbsite, Zirconia, Sand, and Stainless Steel, with stainless steel particles representing the heavier particles, e.g., plutonium, and supernatant were charged to the test tank and rotating liquid jets were used to mix most of the solids while the simulant was pumped out. Subsequently, the volume and shape of the mounds of residual solids and the spatial concentration profiles for the surrogate for heavier particles were measured. Several techniques were developed and equipment designed to accomplish the measurements needed and they included: 1. Magnetic particle separator to remove simulant stainless steel solids. A device was designed and built to capture these solids, which represent the heavier solids during a waste transfer from a staging tank. 2. Photographic equipment to determine the volume of the solids mounds. The mounds were photographed as they were exposed at different tank waste levels to develop a composite of topographical areas. 3. Laser rangefinders to determine the volume of

  17. AN OPEN LABEL PROSPE CTIVE RANDOMIZED TRI AL TO COMPARE THE EFFICACY OF SALICYLI C ACID OINTMENT 3% V ERSUS BETAMETHASONE DIPROPIONATE OINTMEN T IN THE TREATMENT O F LIMITED CHRONIC PLAQUE PSORIASIS

    Santha Bai

    2015-05-01

    Full Text Available AIMS AND OBJECTIVES: There is no study comparing Salicylic acid v s . betamethasone dipropionate ointment in limited chronic plaque psoriasis . The aim of this study is to compare the efficacy and safety of topical application of salicylic acid ointment with betamethasone dipropionate ointment applied once at night for 12 we eks for the treatment of limited chronic plaque psoriasis . MATERIALS AND METHODS: A total of 62 patients of limited chronic plaque psoriasis ( body surface area <10% were randomized into two treatment groups : Group A received topical application with 3% sa licylic acid ointment and Group B received betamethasone dipropionate , once at night for 12 weeks . Results were assessed based on psoriasis area severity index ( PASI scores and patient global assessment ( PGA at each visit . RESULTS: Mean PASI was signifi cantly lower at week 2 ( P=0 . 01 and week 4 follow - up ( P=0 . 05 and the mean reduction in PASI was significantly higher at week 2 ( P=0 . 02 with betamethasone than salicylic acid , but this difference was not sustained at subsequent follow - up visits . Similarly , PGA scores at weeks 2 and 4 were significantly lower with betamethasone dipropionate ointment ( P=0 . 003 and P=0 . 007 respectively . There was no significant difference in any parameter during subsequent follow - up visits or at the end of the treatment phase ( 12 weeks . CONCLUSION: Topical nightly application of betamethasone dipropionate ointment leads to an initial , more rapid reduction in disease severity , but the overall outcome parameters are comparable in the two treatment groups .

  18. Limits for Life

    Marion, Giles M.; Kargel, Jeffrey S.

    The current mantra of astrobiology is “Follow the Water.” Where there is water, there may be life. The FREZCHEM model can determine the presence or absence of water down to the eutectic temperature, below which only solid phases are thermodynamically stable. Salinity, the desiccation potential, and acidity are other potentially life-limiting factors that are calculated by FREZCHEM. In Chapter 4, we discuss potential life-limiting factors such as temperature, salinity, acidity, desiccation, radiation, pressure, and time.

  19. Sobre limites e fronteiras: a reprodutibilidade do estoque territorial para os fins da acumulação capitalista Limites et frontières : la reproductibilité de la réserve territoriale aux fins d’accumulation capitaliste

    César Ricardo Simoni Santos

    2011-01-01

    As palavras fronteira e limite, não raro, são empregadas como sinônimos, apesar da redução implicada nesse gesto. Mas não é difícil reconhecer que a primeira aparece mais frequentemente associada aos fenômenos espaciais enquanto a segunda parece estar mais próxima da indicação de fim ou esgotamento de qualquer natureza. É possível pensar numa relação entre elas, entretanto. No plano econômico, os limites da reprodução capitalista andam a par com a situação das fronteiras desse mesmo modo de p...

  20. Relationship between muscle lactic acid accumulation and exercise-induced fatigue%肌肉乳酸堆积与运动性疲劳关系的再认识

    方宏义; 崔晨

    2015-01-01

    From the exercise-induced fatigue and its production mechanism, this article research progress of lactic acid and exercise-induced fatigue, to discuss of the advantages and disadvantages aspect of the lactic acid to the fatigue, aims to provide a reference for the coaches for scientific training.%从运动性疲劳及其产生机制入手,对乳酸与运动性疲劳的研究进展进行阐述,旨在为运动员进行科学训练提供参考。

  1. The Antiproton Accumulator (AA)

    1980-01-01

    A section of the AA where the dispersion (and hence the horizontal beam size) is large. One can distinguish (left to right): A large vacuum-tank, a quadrupole (QDN09*), a bending magnet (BST08), another vacuum-tank, a wide quadrupole (QFW08) and (in the background) a further bending magnet (BST08). The tanks are covered with heating tape for bake-out. The tank left of QDN09 contained the kickers for stochastic pre-cooling (see 790621, 8002234, 8002637X), the other one served mainly as vacuum chamber in the region where the beam was large. Peter Zettwoch works on QFW08. * see: H. Koziol, Antiproton Accumulator Parameter List, PS/AA/Note 84-2 (1984) See under 7911303, 7911597X, 8004261 and 8202324. For photos of the AA in different phases of completion (between 1979 and 1982) see: 7911303, 7911597X, 8004261, 8004608X, 8005563X, 8005565X, 8006716X, 8006722X, 8010939X, 8010941X, 8202324, 8202658X, 8203628X .

  2. Batteries and accumulators in France

    The present report gives an overview of the batteries and accumulators market in France in 2011 based on the data reported through ADEME's Register of Batteries and accumulators. In 2001, the French Environmental Agency, known as ADEME, implemented a follow-up of the batteries and accumulators market, creating the Observatory of batteries and accumulators (B and A). In 2010, ADEME created the National Register of producers of Batteries and Accumulators in the context of the implementation of the order issued on November 18, 2009. This is one of the four enforcement orders for the decree 2009-1139 issued on September 22, 2009, concerning batteries and accumulators put on the market and the disposal of waste batteries and accumulators, and which transposes the EU-Directive 2006/66/CE into French law. This Register follows the former Observatory for batteries and accumulators. This Register aims to record the producers on French territory and to collect the B and A producers and recycling companies' annual reporting: the regulation indeed requires that all B and A producers and recycling companies report annually on the Register the quantities of batteries and accumulators they put on the market, collect and treat. Based on this data analysis, ADEME issues an annual report allowing both the follow-up of the batteries and accumulators market in France and communication regarding the achievement of the collection and recovery objectives set by EU regulation. This booklet presents the situation in France in 2011

  3. Systems of Accumulation and the Evolving MEC

    Ashman, Sam; Fine, Ben; Newman, Susan

    2013-01-01

    textabstractThe limitations of the Developmental State Paradigm were discussed in the introductory chapter to this volume. This chapter offers an alternative approach to the DSP through use of the notion of systems of (capital) accumulation and its specific application to South Africa’s evolving political economy, which we characterise as the ‘Minerals-Energy Complex’ (MEC) following Fine and Rustomjee (1996).

  4. Sucrose accumulation in mature sweet melon fruits

    Mesocarp tissue from sucrose-accumulating sweet melon (Cucumis melo cv. Galia) showed sucrose synthase activity (ca 1 nkat/gfw) while soluble acid invertase and sucrose phosphate synthase activities were not observed. Sucrose uptake into mesocarp discs was linear with sucrose concentration (1-500 mM) and unaffected by PCMBS and CCCP. Sucrose compartmentation into the vacuole also increased linearly with sucrose concentration as indicated by compartmental efflux kinetics. Mesocarp discs incubated in 14C-fructose + UDP-glu synthesized 14C-sucrose and efflux kinetics indicated that the 14C-sucrose was compartmentalized. These data support the hypothesis that two mechanisms are involved in sucrose accumulation in sweet melon: (1) compartmentation of intact sucrose and (2) synthesis of sucrose via sucrose synthase and subsequent compartmentation in the vacuole

  5. Accumulation Properties of Conjuagted Linoleic Acid Isomers Biosynthesized by Ruminal Bacteria%瘤胃细菌生物合成共轭亚油酸的累积特性

    刘晓华; 李海星; 陈燕; 曹郁生

    2011-01-01

    为了解瘤胃细菌生物合成共轭亚油酸(CLA)的特性,通过毛细管电泳(CE)分析,发现瘤胃细菌生物合成CLA的主要异构体有c9,t11-CLA、t10,c12-CLA和t9,t11-CLA 3种。在厌氧和有氧条件下,瘤胃细菌均能合成CLA,且氧气有利于CLA的累积,随反应时间的延长,CLA的量呈现先增加后减少的变化趋势。结果表明瘤胃细菌参与了反刍动物体内CLA异构体的生物合成与代谢,瘤胃细菌生物合成CLA异构体的特异性还有待更深入的研究。%In order to understand accumulation properties of conjugated linoleic acid(CLA) biosynthesized by ruminal bacteria,capillary electrophoresis(ce)was used to analyze CLA isomers.Three main isomers including c9,t11-CLA,t10,c12-CLA and t9,t11-CLA were synthesized by ruminal bacteria under both anaerobic and aerobic conditions.Aerobic environment was more beneficial for the accumulation of CLA than anaerobic environment.The yield of CLA exhibited a trend of initial increase and final decrease.Therefore,ruminal bacteria play key roles in the biosynthesis and metabolism of CLA in rumen.

  6. Influence of ionic strength and pH on the limitation of latex microsphere deposition sites on iron-oxide coated sand by humic acid

    Yang, X. [School of Planning, Architecture and Civil Engineering, Queen' s University Belfast, David Keir Building, Stranmillis Road, Belfast BT9 5AG, N. Ireland (United Kingdom); Flynn, R., E-mail: r.flynn@qub.ac.uk [School of Planning, Architecture and Civil Engineering, Queen' s University Belfast, David Keir Building, Stranmillis Road, Belfast BT9 5AG, N. Ireland (United Kingdom); Kammer, F. von der, E-mail: frank.von.der.kammer@univie.ac.at [Department of Environmental Geosciences, University of Vienna, Althanstrasse 14, 1090 Vienna (Austria); Hofmann, T. [Department of Environmental Geosciences, University of Vienna, Althanstrasse 14, 1090 Vienna (Austria)

    2011-07-15

    This study, for the first time, investigates and quantifies the influence of slight changes in solution pH and ionic strength (IS) on colloidal microsphere deposition site coverage by Suwannee River Humic Acid (SRHA) in a column matrix packed with saturated iron-oxide coated sand. Triple pulse experimental (TPE) results show adsorbed SRHA enhances microsphere mobility more at higher pH and lower IS and covers more sites than at higher IS and lower pH. Random sequential adsorption (RSA) modelling of experimental data suggests 1 {mu}g of adsorbed SRHA occupied 9.28 {+-} 0.03 x 10{sup 9} sites at pH7.6 and IS of 1.6 mMol but covered 2.75 {+-} 0.2 x 10{sup 9} sites at pH6.3 and IS of 20 mMol. Experimental responses are suspected to arise from molecular conformation changes whereby SRHA extends more at higher pH and lower ionic strength but is more compact at lower pH and higher IS. Results suggest effects of pH and IS on regulating SRHA conformation were additive. - Highlights: > We quantified the coupled role of pH and IS and humic acid on colloid deposition. > Humic acid enhances microsphere mobility more at higher pH and lower IS. > pH and IS may control the behaviour of humic acid by regulating its conformation. > The effect of pH and IS on regulating humic acid conformation is additive. - This paper quantifies the impact of pH and ionic strength on the transient deposition behaviour of colloids in porous medium in the presence of humic acid.

  7. The effect of CaCl2 on growth rate, wood decay and oxalic acid accumulation in Serpula lacrymans and related brown-rot fungi

    Hastrup, Anne Christine Steenkjær; Jensen, Bo; Clausen, Carol. A.;

    2006-01-01

    for 12 strains of S. lacrymans and compared to five brown-rot fungi. This was done by treating copper citrate (CC)-treated Southern yellow pine (SYP) wood with a CaCl2 solution and estimating the decay rate and amount of soluble oxalic acid in an ASTM soil block test. Decay by S. lacrymans was found...... containing CaCl2. In summary, a marked decrease was observed in the decay capacity of S. lacrymans in pine treated with CC+CaCl2. The amount of soluble oxalic acid was measured in CC-treated blocks and blocks also treated with CaCl2. Of the comparative brown-rot fungi, both Antrodia vaillantii (TFFH 294) and...

  8. Systemic ceramide accumulation leads to severe and varied pathological consequences

    Alayoubi, Abdulfatah M; Wang, James C M; Au, Bryan C.Y.; Carpentier, Stéphane; Garcia, Virginie; Dworski, Shaalee; El-Ghamrasni, Samah; Kirouac, Kevin N.; Exertier, Mathilde J; Xiong, Zi Jian; Privé, Gilbert G.; Calogera M Simonaro; Casas, Josefina; Fabrias, Gemma; Schuchman, Edward H.

    2013-01-01

    Farber disease (FD) is a severe inherited disorder of lipid metabolism characterized by deficient lysosomal acid ceramidase (ACDase) activity, resulting in ceramide accumulation. Ceramide and metabolites have roles in cell apoptosis and proliferation. We introduced a single-nucleotide mutation identified in human FD patients into the murine Asah1 gene to generate the first model of systemic ACDase deficiency. Homozygous Asah1 P361R/P361R animals showed ACDase defects, accumulated ceramide, de...

  9. Metal Accumulation, Blood δ-Aminolevulinic Acid Dehydratase Activity and Micronucleated Erythrocytes of Feral pigeons (Columba Livia) Living Near Former Lead-Zinc Smelter “ Trepça” – Kosovo

    Elezaj I. R.; Selimi I. Q.; Letaj K. Rr.; Millaku L. B.; Sefaja L.

    2013-01-01

    The concentration of lead in blood and tibia (Pb), zinc (Zn) and cupper (Cu) in tibia, blood δ- aminolevulinic acid dehydratase (ALA-D; EC: 4.2.1.24) activity, hematocrit value (Hct) and micronuclei frequency (MN) of peripheral erythrocytes have been determinated in three different populations of feral pigeons (Columba livia; forma urbana and forma domestica), collected in Mitrovica town (situated close to smelter “Trepça”, down closed in 2000 year ) and in rural area (Koshare willage ) . The...

  10. Biodegradation of poly(lactic acid), poly(hydroxybutyrate-co-hydroxyvalerate), poly(butylene succinate) and poly(butylene adipate-co-terephthalate) under anaerobic and oxygen limited thermophilic conditions

    Jutakan Boonmee; Charnwit Kositanont; Thanawadee Leejarkpai

    2016-01-01

    In order to study the biodegradation behavior of biodegradable plastics in landfill conditions, four types of biodegradable plastics including poly(lactic acid) (PLA), poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV), poly(butylene succinate) (PBS), and poly(butylene adipate-co-terephthalate) (PBAT) were tested by burying in sludge mixed soil medium under anaerobic and oxygen limited conditions. The experiments were operated at 52 ± 2ºC in dark conditions according to ISO15985. The degree of b...

  11. Limited evidence for trans-generational effects of maternal dietary supplementation with ¿-3 fatty acids on immunity in broiler chickens

    Koppenol, A.; Delezie, E.; Parmentier, H.K.; Buyse, J.; Everaert, N.

    2015-01-01

    The aim of the present study was to investigate whether the immune response of broiler chickens is modulated by including different omega-3 (¿-3) polyunsaturated fatty acids (PUFAs) in the maternal diet. Broiler breeder hens (n¿=¿120 birds per group) were fed one of four diets, differing in the rati

  12. Phospholipids accumulation in mucolipidosis IV cultured fibroblasts.

    Bargal, R; Bach, G

    1988-01-01

    Cultured fibroblasts from mucolipidosis IV patients accumulated phospholipids when compared to normal controls or cells from other genotypes. The major stored compounds were identified as phosphatidylcholine, phosphatidylethanolamine and to a larger extent lysophosphatidylcholine and lysobisphosphatidic acid. Pulse chase experiments of 32P-labelled phospholipids showed increased retention of these compounds in the mucolipidosis IV lines throughout the pulse and chase periods. Phospholipase A1, A2, C, D and lysophospholipase showed normal activity in the mucolipidosis IV lines and thus the metabolic cause for this storage remains to be identified. PMID:3139925

  13. Major histocompatibility complex class I-related chain A/B (MICA/B) expression in tumor tissue and serum of pancreatic cancer: Role of uric acid accumulation in gemcitabine-induced MICA/B expression

    Major histocompatibility complex class I-related chain A and B (MICA/B) are two stress-inducible ligands that bind the immunoreceptor NKG2D and play an important role in mediating the cyotoxicity of NK and T cells. In this study, we sought to study MICA/B expression in pancreatic cancer and to determine whether and how genotoxic drugs such as gemcitabine can affect MICA/B expression and natural killer cytotoxity. Seven pancreatic cancer cell lines were analyzed for MICA/B expression by flow cytometry and for their sensitivity to NK-92 cell killing by a 51Cr release assay. MICA/B expression in tumor tissues and sera of pancreatic cancer was analyzed by immunohistochemical staining (IHC) and ELISA, respectively. Two MICA/B-positive cell lines were sensitive to the cytotoxic activity of NK-92 cells. Other two MICA/B-positive cell lines and three MICA/B-negative cell lines were resistant to NK-92 cell killing. MICA/B expression was positive in 17 of 25 (68%) pancreatic ductal adenocarcinomas but not in normal pancreatic ductal epithelial cells. Serum MICA/B levels were significantly elevated in patients with pancreatic adenocarcinomas but did not correlate with the stage of pancreatic cancer and patient survival. Gemcitabine therapy led to increased serum MICA levels in 6 of 10 patients with detectable serum MICA. Allopurinol, an inhibitor of xanthine oxidoreductase that converts xanthine to uric acid, blocked uric acid production, MICA/B expression, and sensitivity to NK-92 cell killing toward a PANC-1 cancer cell line exposed to radiation and two genotoxic drugs, gemcitabine and 5-fluorouracil. The levels of MICA/B expression in serum and tissue of pancreatic cancer are elevated. DNA damage-induced MICA/B expression is mediated through increased uric acid production

  14. (Accumulation of methyl-deficient rat liver messenger ribonucleic acid on ethionine administration). Progress report. [Methyltransferase activity in Ehrlich ascites tumor cells and effects of phorbol ester on methyltransferase activity

    Borek, E.

    1980-01-01

    Enzyme fractions were isolated from Ehrlich ascites cells which introduced methyl groups into methyl deficient rat liver mRNA and unmethylated vaccinia mRNA. The methyl groups were incorporated at the 5' end into cap 1 structures by the viral enzyme, whereas both cap 0 and cap 1 structures were formed by the Ehrlich ascites cell enzymes. Preliminary results indicate the presence of adenine N/sup 6/-methyltransferase activity in Ehrlich ascites cells. These results indicate that mRNA deficient in 5'-cap methylation and in internal methylation of adenine accumulated in rats on exposure to ethionine. The methyl-deficient mRNA isolated from the liver of ethionine-fed rats differed in its translational properties from mRNA isolated from control animals. Preliminary experiments indicate that single topical application of 17n moles of TPA to mouse skin altered tRNA methyltransferases. The extent of methylation was increased over 2-fold in mouse skin treated with TPA for 48 hours. These changes have been observed as early as 12 hours following TPA treatment. In contrast, the application of initiating dose of DMBA had no effect on these enzymes. It should be emphasized that the changes in tRNA methyltransferases produced by TPA are not merely an increase of the concentration of the enzyme, rather that they represent alterations of specificity of a battery of enzymes. In turn the change in enzyme specificity can produce alterations in the structure of tRNA. (ERB)

  15. Carnosic acid-rich rosemary (Rosmarinus officinalis L.) leaf extract limits weight gain and improves cholesterol levels and glycaemia in mice on a high-fat diet

    Chiralt Boix, Mª Amparo; Cases, Julien; Coussaert, Aurélie Coussaert; Roller, Marc; Ripoll, Christophe

    2011-01-01

    Rosemary (Rosmarinus officinalis L.) extracts (RE) are natural antioxidants that are used in food, food supplements and cosmetic applications; exert anti-inflammatory and anti-hyperglycaemic effects; and promote weight loss, which can be exploited to develop new preventive strategies against metabolic disorders. Therefore, the aim of the present study was to evaluate the preventive effects of rosemary leaf extract that was standardised to 20 % carnosic acid (RE) on weight gain, glucose levels...

  16. Lauric acid-rich medium-chain triglycerides can substitute for other oils in cooking applications and may have limited pathogenicity.

    McCarty, Mark F; DiNicolantonio, James J

    2016-01-01

    Recently, medium-chain triglycerides (MCTs) containing a large fraction of lauric acid (LA) (C12)-about 30%-have been introduced commercially for use in salad oils and in cooking applications. As compared to the long-chain fatty acids found in other cooking oils, the medium-chain fats in MCTs are far less likely to be stored in adipose tissue, do not give rise to 'ectopic fat' metabolites that promote insulin resistance and inflammation, and may be less likely to activate macrophages. When ingested, medium-chain fatty acids are rapidly oxidised in hepatic mitochondria; the resulting glut of acetyl-coenzyme A drives ketone body production and also provokes a thermogenic response. Hence, studies in animals and humans indicate that MCT ingestion is less obesogenic than comparable intakes of longer chain oils. Although LA tends to raise serum cholesterol, it has a more substantial impact on high density lipoprotein (HDL) than low density lipoprotein (LDL) in this regard, such that the ratio of total cholesterol to HDL cholesterol decreases. LA constitutes about 50% of the fatty acid content of coconut oil; south Asian and Oceanic societies which use coconut oil as their primary source of dietary fat tend to be at low cardiovascular risk. Since ketone bodies can exert neuroprotective effects, the moderate ketosis induced by regular MCT ingestion may have neuroprotective potential. As compared to traditional MCTs featuring C6-C10, laurate-rich MCTs are more feasible for use in moderate-temperature frying and tend to produce a lower but more sustained pattern of blood ketone elevation owing to the more gradual hepatic oxidation of ingested laurate. PMID:27547436

  17. Limited evidence for trans-generational effects of maternal dietary supplementation with ω-3 fatty acids on immunity in broiler chickens.

    Koppenol, Astrid; Delezie, Evelyne; Parmentier, Henk K; Buyse, Johan; Everaert, Nadia

    2015-02-01

    The aim of the present study was to investigate whether the immune response of broiler chickens is modulated by including different omega-3 (ω-3) polyunsaturated fatty acids (PUFAs) in the maternal diet. Broiler breeder hens (n = 120 birds per group) were fed one of four diets, differing in the ratios of n-6:n-3 PUFAs and eicosapentaenoic acid (EPA):docosahexaenoic acid (DHA). At 28 weeks of age, the eggs produced were incubated to obtain 720 chicks (n = 180 per group). All broiler chicks were fed a control diet and were vaccinated against Newcastle disease virus (NDV). Blood samples were taken at different time points after immunisation with human serum albumin (HuSA) in Freund's adjuvant to determine the acute phase response, antibody response and cytokine production. Addition of EPA to the maternal diet was associated with greater ovotransferrin concentrations post-immunisation, compared to other groups. Altering the ratios of n-6:n-3 PUFA or EPA:DHA in the maternal diet did not affect the offspring in terms of production of caeruloplasmin, α1-acid glycoprotein, interleukin (IL)-1β, IL-6, IL-12 or tumour necrosis factor (TNF)-α. Dietary manipulation of the maternal diet did not influence the specific antibody response to HuSA or NDV, nor did it alter the levels of natural antibody binding to keyhole limpet haemocyanin in the offspring. Thus, maternal supplementation with n-3 PUFAs played a minor role in perinatal programming of the immune response of broiler chickens. PMID:25576140

  18. Self-limited uptake of α-pinene oxide to acidic aerosol: the effects of liquid–liquid phase separation and implications for the formation of secondary organic aerosol and organosulfates from epoxides

    G. T. Drozd

    2013-08-01

    Full Text Available The reactive uptake of α-pinene oxide (αPO to acidic sulfate aerosol was studied under humid conditions in order to gain insight into the effects of liquid–liquid phase separation on aerosol heterogeneous chemistry and to elucidate further the formation of secondary organic aerosol and organosulfates from epoxides. A continuous flow environmental chamber was used to monitor changes in diameter of monodisperse, deliquesced, acidic sulfate particles exposed to αPO at 25% and 50% RH (relative humidity. In order to induce phase separation and probe potential limits to particle growth from acidic uptake, αPO was introduced over a wide range of concentrations, from 200 ppb to 5 ppm. Uptake was observed to be highly dependent on initial aerosol pH. Significant uptake of αPO to aerosol was observed with initial pH Kp, eff were in the range of (0.1–2 x 10-4 m3μg-1 and were correlated to initial particle acidity and particle organic content; particles with higher organic content had lower partition coefficients. Effective uptake coefficients (γeff ranged from 0.1 to 1.1 x 10-4 and are much lower than recently reported for uptake to bulk solutions. In experiments in which αPO was added to bulk H2SO4 solutions, phase separation was observed for mass loadings similar to those observed with particles, and product distributions were dependent on acid concentration. Liquid–liquid phase separation in bulk experiments, along with our observations of decreased uptake to particles with the largest growth factors, suggests an organic coating forms upon uptake to particles, limiting reactive uptake.

  19. Self-limited uptake of α-pinene-oxide to acidic aerosol: the effects of liquid-liquid phase separation and implications for the formation of secondary organic aerosol and organosulfates from epoxides

    G. T. Drozd

    2013-03-01

    Full Text Available The reactive uptake of α-pinene oxide (αPO to acidic sulfate aerosol was studied under humid conditions in order to gain insight into the effects of liquid-liquid phase separation on aerosol heterogeneous chemistry and further elucidate the formation of secondary organic aerosol and organosulfates from epoxides. A continuous flow environmental chamber was used to monitor changes in diameter of monodisperse, deliquesced, acidic sulfate particles exposed to αPO at 30 and 50% RH. In order to induce phase separation and probe potential limits to particle growth from acidic uptake, αPO was introduced over a wide range of concentrations, from 200 ppb to 5 ppm. Uptake was observed to be highly dependent on initial aerosol pH. Significant uptake of αPO to aerosol was observed with initial pH Kp ranged from 0.2–1.6 × 10−4 m3 μg−1 and were correlated to initial particle acidity and particle organic content; particles with higher organic content had lower partition coefficients. Effective uptake coefficients (γ ranged from 0.4 to 4.7 × 10−5 and are much lower than recently reported for uptake to bulk solutions. In experiments in which αPO was added to bulk H2SO4 solutions, phase separation was observed for mass loadings similar to those observed with particles, and product distributions were dependent on acid concentration. Liquid-liquid phase separation in bulk experiments, along with our observations of decreased uptake to particles with the largest growth factors, suggest an organic coating forms upon uptake to particles, limiting reactive uptake.

  20. Adaptation and tolerance of bacteria against acetic acid.

    Trček, Janja; Mira, Nuno Pereira; Jarboe, Laura R

    2015-08-01

    Acetic acid is a weak organic acid exerting a toxic effect to most microorganisms at concentrations as low as 0.5 wt%. This toxic effect results mostly from acetic acid dissociation inside microbial cells, causing a decrease of intracellular pH and metabolic disturbance by the anion, among other deleterious effects. These microbial inhibition mechanisms enable acetic acid to be used as a preservative, although its usefulness is limited by the emergence of highly tolerant spoilage strains. Several biotechnological processes are also inhibited by the accumulation of acetic acid in the growth medium including production of bioethanol from lignocellulosics, wine making, and microbe-based production of acetic acid itself. To design better preservation strategies based on acetic acid and to improve the robustness of industrial biotechnological processes limited by this acid's toxicity, it is essential to deepen the understanding of the underlying toxicity mechanisms. In this sense, adaptive responses that improve tolerance to acetic acid have been well studied in Escherichia coli and Saccharomyces cerevisiae. Strains highly tolerant to acetic acid, either isolated from natural environments or specifically engineered for this effect, represent a unique reservoir of information that could increase our understanding of acetic acid tolerance and contribute to the design of additional tolerance mechanisms. In this article, the mechanisms underlying the acetic acid tolerance exhibited by several bacterial strains are reviewed, with emphasis on the knowledge gathered in acetic acid bacteria and E. coli. A comparison of how these bacterial adaptive responses to acetic acid stress fit to those described in the yeast Saccharomyces cerevisiae is also performed. A systematic comparison of the similarities and dissimilarities of the ways by which different microbial systems surpass the deleterious effects of acetic acid toxicity has not been performed so far, although such exchange

  1. Arsenic accumulation by edible aquatic macrophytes.

    Falinski, K A; Yost, R S; Sampaga, E; Peard, J

    2014-01-01

    Edible aquatic macrophytes grown in arsenic (As)-contaminated soil and sediment were investigated to determine the extent of As accumulation and potential risk to humans when consumed. Nasturtium officinale (watercress) and Diplazium esculentum (warabi) are two aquatic macrophytes grown and consumed in Hawaii. Neither has been assessed for potential to accumulate As when grown in As-contaminated soil. Some former sugarcane plantation soils in eastern Hawaii have been shown to have concentrations of total As over 500 mg kg(-1). It was hypothesized that both species will accumulate more As in contaminated soils than in non-contaminated soils. N. officinale and D. esculentum were collected in areas with and without As-contaminated soil and sediment. High soil As concentrations averaged 356 mg kg(-1), while low soil As concentrations were 0.75 mg kg(-1). Average N. officinale and D. esculentum total As concentrations were 0.572 mg kg(-1) and 0.075 mg kg(-1), respectively, corresponding to hazard indices of 0.12 and 0.03 for adults. Unlike previous studies where watercress was grown in As-contaminated water, N. officinale did not show properties of a hyperaccumulator, yet plant concentrations in high As areas were more than double those in low As areas. There was a slight correlation between high total As in sediment and soil and total As concentrations in watercress leaves and stems, resulting in a plant uptake factor of 0.010, an order of magnitude higher than previous studies. D. esculentum did not show signs of accumulating As in the edible fiddleheads. Hawaii is unique in having volcanic ash soils with extremely high sorption characteristics of As and P that limit release into groundwater. This study presents a case where soils and sediments were significantly enriched in total As concentration, but the water As concentration was below detection limits. PMID:24210365

  2. Differences in acidity of apples are probably mainly caused by a malic acid transporter gene on LG16

    Khan, S.A.; Beekwilder, J.; Schaart, J.G.; Mumm, R.; Soriano, J.M.; Jacobsen, E.; Schouten, H.J.

    2013-01-01

    Acidity has profound effects on the taste of apples (Malus × domestica). Malic acid is the predominant organic acid in apples. Differences in malic acid content are caused by differences in accumulation of malic acid in the vacuole. This accumulation may be caused by a gene that is responsible for t

  3. Thioesterase superfamily member 1 suppresses cold thermogenesis by limiting the oxidation of lipid droplet-derived fatty acids in brown adipose tissue

    Kosuke Okada

    2016-05-01

    Conclusions: These results show that Them1 may act as a break on uncontrolled heat production and limit the extent of energy expenditure. Pharmacologic inhibition of Them1 could provide a targeted strategy for the management of metabolic disorders via activation of brown fat.

  4. Accumulation of uranium by immobilized persimmon tannin

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

  5. Evidence accumulation for spatial reasoning

    Matsuyama, T.; Hwang, V. S. S.; Davis, L. S.

    1984-01-01

    The evidence accumulation proces of an image understanding system is described enabling the system to perform top-down(goal-oriented) picture processing as well as bottom-up verification of consistent spatial relations among objects.

  6. Oligopoly banking and capital accumulation

    Nicola Cetorelli; Pietro F. Peretto

    2000-01-01

    We develop a dynamic general equilibrium model of capital accumulation where credit is intermediated by banks operating in a Cournot oligopoly. The number of banks affects capital accumulation through two channels. First, it affects the quantity of credit available to entrepreneurs. Second, it affects banks' decisions to collect costly information about entrepreneurs, and thus determines the efficiency of the credit market. We show that under plausible conditions, the market structure that ma...

  7. Cystathionine accumulation in Saccharomyces cerevisiae.

    Ono, B; Suruga, T; Yamamoto, M.; Yamamoto, S.; Murata, K; Kimura, A; Shinoda, S; Ohmori, S.

    1984-01-01

    A cysteine-dependent strain of Saccharomyces cerevisiae and its prototrophic revertants accumulated cystathionine in cells. The cystathionine accumulation was caused by a single mutation having a high incidence of gene conversion. The mutation was designated cys3 and was shown to cause loss of gamma-cystathionase activity. Cysteine dependence of the initial strain was determined by two linked and interacting mutations, cys3 and cys1 . Since cys1 mutations cause a loss of serine acetyltransfer...

  8. Hormesis in Cholestatic Liver Disease; Preconditioning with Low Bile Acid Concentrations Protects against Bile Acid-Induced Toxicity

    Verhaag, Esther M.; Manon Buist-Homan; Martijn Koehorst; Groen, Albert K; Han Moshage; Klaas Nico Faber

    2016-01-01

    Introduction Cholestasis is characterized by accumulation of bile acids and inflammation, causing hepatocellular damage. Still, liver damage markers are highest in acute cholestasis and drop when this condition becomes chronic, indicating that hepatocytes adapt towards the hostile environment. This may be explained by a hormetic response in hepatocytes that limits cell death during cholestasis. Aim To investigate the mechanisms that underlie the hormetic response that protect hepatocytes agai...

  9. An open label prospective randomized trial to compare the efficacy of coal tar-salicylic acid ointment versus calcipotriol/betamethasone dipropionate ointment in the treatment of limited chronic plaque psoriasis

    Sujay Khandpur

    2014-01-01

    Full Text Available Background: Chronic plaque psoriasis is a common papulosquamous skin disorder, for which a number of topical agents are being used including coal tar, topical steroids and more recently topical calcipotriol/betamethasone dipropionate. There is no study comparing purified coal tar preparation with calcipotriol/betamethasone dipropionate ointment in limited chronic plaque psoriasis. Aims and Objectives: A prospective randomized open label controlled trial to compare the efficacy and safety of topical application of coal tar-salicylic acid ointment with calcipotriol/betamethasone dipropionate ointment applied once at night for 12 weeks for the treatment of limited chronic plaque psoriasis. Materials and Methods: A total of 62 patients of limited chronic plaque psoriasis (body surface area <10% were randomized into two treatment groups: Group A received topical application of 6% coal tar with 3% salicylic acid ointment and Group B received calcipotriol/betamethasone dipropionate, once at night for 12 weeks. Results were assessed based on psoriasis area severity index (PASI scores and patient global assessment (PGA at each visit. Results: Mean PASI was significantly lower at week 2 (P = 0.01 and week 4 follow-up (P = 0.05 and the mean reduction in PASI was significantly higher at week 2 (P = 0.02 with calcipotriol/betamethasone than coal tar-salicylic acid, but this difference was not sustained at subsequent follow-up visits. Similarly, PGA scores at weeks 2 and 4 were significantly lower with calcipotriol/betamethasone dipropionate ointment (P = 0.003 and P = 0.007 respectively. There was no significant difference in any parameter during subsequent follow-up visits or at the end of the treatment phase (12 weeks. Conclusion: Topical nightly application of calcipotriol/betamethasone dipropionate ointment leads to an initial, more rapid reduction in disease severity, but the overall outcome parameters are comparable in the two treatment groups.

  10. Metal Accumulation, Blood δ-Aminolevulinic Acid Dehydratase Activity and Micronucleated Erythrocytes of Feral pigeons (Columba Livia Living Near Former Lead-Zinc Smelter “ Trepça” – Kosovo

    Elezaj I. R.

    2013-04-01

    Full Text Available The concentration of lead in blood and tibia (Pb, zinc (Zn and cupper (Cu in tibia, blood δ- aminolevulinic acid dehydratase (ALA-D; EC: 4.2.1.24 activity, hematocrit value (Hct and micronuclei frequency (MN of peripheral erythrocytes have been determinated in three different populations of feral pigeons (Columba livia; forma urbana and forma domestica, collected in Mitrovica town (situated close to smelter “Trepça”, down closed in 2000 year and in rural area (Koshare willage . The blood lead level in feral pigeons from Mitrovica (forma urbana was 3 times higher (149.6; 50.5 μg% in comparison with that in feral pigeons from Mitrovica (forma domestica and 27.7 times higher (5.4 μg% in comparison with pigeons from rural area. The Pb concentration of tibia of feral pigeons (froma urbana and forma domestica, from Mitrovica town was significantly higher (P<0.001 in comparison with control. The concentration of Zn in tibia of feral pigeons from Mitrovica town (forma urbana, was significantly higher (P<0.006 in comparison with control. The blood ALA-D activity of feral pigeons from Mitrovica town (forma urbana and froma domestica, was significantly inhibited in comparison with control. The blood ALA-D activity of feral pigeons –forma urbana from Mitrovica town was significantly inhibited (P<0.001 in comparison with the blood ALA-D activity of feral pigeons-forma domestica from Mitrovica town. The erythrocyte MN frequency of feral pigeons from Mitrovica was significantly higher (P <0.001 in comparison with controls. The smelter “Trepça” ten year after closed down pose a threat to the local environment, biota and people’s health.

  11. Mercury accumulation of three Lactarius mushroom species.

    Falandysz, Jerzy

    2017-01-01

    Accumulation, distribution and potential dietary intake of mercury accumulated by mushrooms of Lactarius species L. delicious, L. volemus and L. deterrimus were studied in the Pomerania region of Poland. In total, 212 fruiting bodies and 106 underlying topsoil samples were analyzed. Analysis indicated that the concentrations of Hg were at low levels both in mushrooms and forest topsoils for a majority of the locations investigated. L. volemus that grew in soils with only a slightly elevated contamination (0.11±0.07mgkg(-1) of dried soil), very efficiently accumulated Hg in fruiting bodies and concentration levels were at 3.7±1.3mgkg(-1) of dry biomass in caps and at 1.9±0.9mgkg(-1) of dry biomass in stipes. Consumption of mushrooms foraged from the Sobowidz forest, which is close to a foundry using ferrous and non-ferrous metals could result in a Hg intake that exceeds the current statutory limits. PMID:27507453

  12. Position of folic acid in fortification of nutrition in neonatal period

    Tatiana Žikavská

    2013-07-01

    Full Text Available Folic acid is an essential vitamin which has been known in recent 50 years. It plays an important role in period of neurogenesis. The substitution of folic acid is one of the important parts in the complex treatment of anaemia in premature newborns. It is also a component of artificial milk formulae or breast milk following mother’s intake. Fortification of foods with folic acid for population in the world is still discussed. To determine optimal dose of folic acid in premature newborns is difficult. Daily recommended doses of folic acid in infants under the six months were identified. The needs of folic acid in newborns vary. It depends upon the gestational age, body reserves at birth or maternal status of folates during gravidity. On the other hand there is a risk of accumulation of unmetabolised folic acid in circulation of newborns after mandatory folic acid fortification in some countries, which were reported in some studies. The safe upper limits of folic acid intake in premature newborns are not known. In this review article authors inform about the clear positive effect of folic acid in prenatal and neonatal period, but excessive doses of folic acid could present risk of accumulation and possible adverse effects. To follow up these notions further studies are required.

  13. Effect of Carbon, Nitrogen Sources on Lipid Accumulation and Fatty Acid Composition of Monoraphidium sp.FXY-10 under Heterotrophic Cultivation%碳源、氮源对异养单针藻Monoraphidium sp.FXY-10油脂积累和脂肪酸组成的影响

    黄力; 贺赐安; 赵鹏; 余旭亚

    2013-01-01

    Effect of carbon and nitrogen sources on heterotrophic cultivation of microalgae Monoraphidium sp. FXY-10 is studied. The biomass, oil accumulation and fatty acid composition of microalgae cell are analysed comparatively by selecting various types and setting different concentrations of carbon and nitrogen sources with BG-11 as basic medium. The results show that microalgae lipid accumulating with glucose as carbon source and sodium nitrate as nitrogen source is an ideal candidate for biodiesel production. The lipid production is not significantly impacted (P > 0. 05) by different sodium nitrate concentration which was 1. 00, 3. 00 and 5.00 g/L, respectively. Moreover, when glucose concentration is 10.00 g/L using sodium nitrate as nitrogen source, lipid production can be obtained the highest experiment value 0. 84 g/L. And the fatty acid of microalgae lipid is mainly composed of short chain saturated and monounsaturated fatty acids, such as C16= 0 and C18: 1. So they result a lower degree of unsaturation (DU) value 61.98.%研究了碳源与氮源对单针藻Monoraphidium sp.FXY-10异养培养的影响.以BG-11为基础培养基,通过添加不同类型、浓度梯度碳源和氮源,比较分析微藻生物量、油脂积累以及脂肪酸组成.结果表明,以葡萄糖作碳源,硝酸钠为氮源,微藻细胞积累的油脂是理想的生物柴油制备原料.硝酸钠浓度分别为1.00、3.00和5.00 g/L时,对油脂产量影响不显著(P>0.05).葡萄糖浓度为10.00 g/L,硝酸钠为氮源油脂产量达到实验最高值0.84 g/L,其油脂脂肪酸组成主要由C16∶0和C18∶1等短链饱和脂肪酸和单不饱和脂肪酸组成,不饱和度值(DU)为61.98,相对偏低.

  14. Non-chemical proton-dependent steps prior to O2-activation limit Azotobacter vinelandii 3-mercaptopropionic acid dioxygenase (MDO) catalysis.

    Crowell, Joshua K; Sardar, Sinjinee; Hossain, Mohammad S; Foss, Frank W; Pierce, Brad S

    2016-08-15

    3-mercaptopropionate dioxygenase from Azotobacter vinelandii (Av MDO) is a non-heme mononuclear iron enzyme that catalyzes the O2-dependent oxidation of 3-mercaptopropionate (3mpa) to produce 3-sulfinopropionic acid (3spa). With one exception, the active site residues of MDO are identical to bacterial cysteine dioxygenase (CDO). Specifically, the CDO Arg-residue (R50) is replaced by Gln (Q67) in MDO. Despite this minor active site perturbation, substrate-specificity of Av MDO is more relaxed as compared to CDO. In order to investigate the relative timing of chemical and non-chemical events in Av MDO catalysis, the pH/D-dependence of steady-state kinetic parameters (kcat and kcat/KM) and viscosity effects are measured using two different substrates [3mpa and l-cysteine (cys)]. The pL-dependent activity of Av MDO in these reactions can be rationalized assuming a diprotic enzyme model in which three ionic forms of the enzyme are present [cationic, E((z+1)); neutral, E(z); and anionic, E((z-1))]. The activities observed for each substrate appear to be dominated by electrostatic interactions within the enzymatic active site. Given the similarity between MDO and the more extensively characterized mammalian CDO, a tentative model for the role of the conserved 'catalytic triad' is proposed. PMID:27311613

  15. Tannins as feed additives to modulate ruminal biohydrogenation: effects on animal performance, milk fatty acid composition and ruminal fermentation in dairy ewes fed a diet containing sunflower oil

    Toral, Pablo G.; Hervás, Gonzalo; Bichi, Elena; Belenguer, Álvaro; Frutos, Pilar

    2011-01-01

    In vitro studies have suggested that feeding tannins to ruminants can favourably alter ruminal biohydrogenation of dietary linoleic acid, enhancing accumulation of trans-11 18:1 (VA, vaccenic acid) in the rumen and thereby the content of some human health promoting fatty acids, such as VA and cis-9 trans-11 18:2 (rumenic acid, RA), in dairy or meat products. However, reports on impacts of these phenolic compounds on milk fatty acid (FA) profile are very limited and inconsistent. Therefore, fo...

  16. How Integrated Management Strategies Promote Protein Quality of Cotton Embryos: High Levels of Soil Available N, N Assimilation and Protein Accumulation Rate

    Yang, HongKun; Meng, YaLi; Chen, BingLin; Zhang, XingYue; Wang, YouHua; Zhao, WenQing; Zhou, ZhiGuo

    2016-01-01

    Cottonseed is widely used as a source of ruminant feed and for industrial purposes. Therefore, there is a tremendous need to improve the nutritional value of cotton embryos. In this study, a conventional management (CM) and two integrated cotton management strategies (IMS1, IMS2) were performed at two soil fertility levels to study the relationships among soil N, N assimilation, embryonic protein accumulation and protein quality. The levels of proteins, essential amino acids, and semi-essential amino acids, especially those of glutamate, lysine, and methionine, were higher in IMS1 and IMS2 embryos than in CM embryos. These changes were significantly positively correlated with the soil-available N content, glutamine synthetase activity and peak value of protein accumulation rate and were negatively correlated with the free amino acid level. These results illustrated that integrated management strategies, especially the rates and timing of N application, raise the level of soil available N, which is beneficial for N assimilation in developing cotton embryos. The protein content was limited by the rate of protein accumulation rather than by the free amino acid content. The combination of target yield fertilization, a growth-driven N application schedule, a high plant density and the seedling raising with bio-organic fertilizer can substantially improve protein quality in cotton embryos, especially at a soil with low soil organic matter and total nitrogen. PMID:27532007

  17. The Effect of Limited Diffusion and Wet–Dry Cycling on Reversible Polymerization Reactions: Implications for Prebiotic Synthesis of Nucleic Acids

    Paul G. Higgs

    2016-06-01

    Full Text Available A long-standing problem for the origins of life is that polymerization of many biopolymers, including nucleic acids and peptides, is thermodynamically unfavourable in aqueous solution. If bond making and breaking is reversible, monomers and very short oligomers predominate. Recent experiments have shown that wetting and drying cycles can overcome this problem and drive the formation of longer polymers. In the dry phase, bond formation is favourable, but diffusion is restricted, and bonds only form between monomers that are initially close together. In the wet phase, some of the bonds are hydrolyzed. However, repositioning of the molecules allows new bonds to form in the next dry phase, leading to an increase in mean polymer length. Here, we consider a simple theoretical model that explains the effect of cycling. There is an equilibrium length distribution with a high mean length that could be achieved if diffusion occurred freely in the dry phase. This equilibrium is inaccessible without diffusion. A single dry cycle without diffusion leads to mean lengths much shorter than this. Repeated cycling leads to a significant increase in polymerization relative to a single cycle. In the most favourable case, cycling leads to the same equilibrium length distribution as would be achieved if free diffusion were possible in the dry phase. These results support the RNA World scenario by explaining a potential route to synthesis of long RNAs; however, they also imply that cycling would be beneficial to the synthesis of other kinds of polymers, including peptides, where bond formation involves a condensation reaction.

  18. The Effect of Limited Diffusion and Wet-Dry Cycling on Reversible Polymerization Reactions: Implications for Prebiotic Synthesis of Nucleic Acids.

    Higgs, Paul G

    2016-01-01

    A long-standing problem for the origins of life is that polymerization of many biopolymers, including nucleic acids and peptides, is thermodynamically unfavourable in aqueous solution. If bond making and breaking is reversible, monomers and very short oligomers predominate. Recent experiments have shown that wetting and drying cycles can overcome this problem and drive the formation of longer polymers. In the dry phase, bond formation is favourable, but diffusion is restricted, and bonds only form between monomers that are initially close together. In the wet phase, some of the bonds are hydrolyzed. However, repositioning of the molecules allows new bonds to form in the next dry phase, leading to an increase in mean polymer length. Here, we consider a simple theoretical model that explains the effect of cycling. There is an equilibrium length distribution with a high mean length that could be achieved if diffusion occurred freely in the dry phase. This equilibrium is inaccessible without diffusion. A single dry cycle without diffusion leads to mean lengths much shorter than this. Repeated cycling leads to a significant increase in polymerization relative to a single cycle. In the most favourable case, cycling leads to the same equilibrium length distribution as would be achieved if free diffusion were possible in the dry phase. These results support the RNA World scenario by explaining a potential route to synthesis of long RNAs; however, they also imply that cycling would be beneficial to the synthesis of other kinds of polymers, including peptides, where bond formation involves a condensation reaction. PMID:27338479

  19. The Effect of Limited Diffusion and Wet–Dry Cycling on Reversible Polymerization Reactions: Implications for Prebiotic Synthesis of Nucleic Acids

    Higgs, Paul G.

    2016-01-01

    A long-standing problem for the origins of life is that polymerization of many biopolymers, including nucleic acids and peptides, is thermodynamically unfavourable in aqueous solution. If bond making and breaking is reversible, monomers and very short oligomers predominate. Recent experiments have shown that wetting and drying cycles can overcome this problem and drive the formation of longer polymers. In the dry phase, bond formation is favourable, but diffusion is restricted, and bonds only form between monomers that are initially close together. In the wet phase, some of the bonds are hydrolyzed. However, repositioning of the molecules allows new bonds to form in the next dry phase, leading to an increase in mean polymer length. Here, we consider a simple theoretical model that explains the effect of cycling. There is an equilibrium length distribution with a high mean length that could be achieved if diffusion occurred freely in the dry phase. This equilibrium is inaccessible without diffusion. A single dry cycle without diffusion leads to mean lengths much shorter than this. Repeated cycling leads to a significant increase in polymerization relative to a single cycle. In the most favourable case, cycling leads to the same equilibrium length distribution as would be achieved if free diffusion were possible in the dry phase. These results support the RNA World scenario by explaining a potential route to synthesis of long RNAs; however, they also imply that cycling would be beneficial to the synthesis of other kinds of polymers, including peptides, where bond formation involves a condensation reaction. PMID:27338479

  20. On limit and limit setting.

    Gorney, J E

    1994-01-01

    This article investigates the role of limit and limit setting within the psychoanalytic situation. Limit is understood to be a boundary between self and others, established as an interactional dimension of experience. Disorders of limit are here understood within the context of Winnicott's conception of the "anti-social tendency." Limit setting is proposed as a necessary and authentic response to the patient's acting out via holding and empathic responsiveness, viewed here as a form of boundary delineation. It is proposed that the patient attempts to repair his or her boundary problem through a seeking of secure limits within the analyst. The setting of secure and appropriate limits must arise from a working through of the analyst's own countertransference response to the patient. It is critical that this response be evoked by, and arise from, the immediate therapeutic interaction so that the patient can experience limit setting as simultaneously personal and authentic. PMID:7972580

  1. Blockade of Lysosomal Acid Ceramidase Induces GluN2B-Dependent Tau Phosphorylation in Rat Hippocampal Slices

    Marie-Elaine Laurier-Laurin; Audrée De Montigny; Suzanne Attiori Essis; Michel Cyr; Guy Massicotte

    2014-01-01

    The lysosomal acid ceramidase, an enzyme known to limit intracellular ceramide accumulation, has been reported to be defective in neurodegenerative disorders. We show here that rat hippocampal slices, preincubated with the acid ceramidase inhibitor (ACI) d-NMAPPD, exhibit increased N-methyl-D-aspartate (NMDA) receptor-mediated field excitatory postsynaptic potentials (fEPSPs) in CA1 synapses. The ACI by itself did not interfere with either paired pulse facilitation or alpha-amino-3-hydroxy-5-...

  2. Loss of Nuclear Receptor SHP Impairs but Does Not Eliminate Negative Feedback Regulation of Bile Acid Synthesis

    Kerr, Thomas A.; Saeki, Shigeru; Schneider, Manfred; Schaefer, Karen; Berdy, Sara; Redder, Thadd; Shan, Bei; Russell, David W.; Schwarz, Margrit

    2002-01-01

    The in vivo role of the nuclear receptor SHP in feedback regulation of bile acid synthesis was examined. Loss of SHP in mice caused abnormal accumulation and increased synthesis of bile acids due to derepression of rate-limiting CYP7A1 and CYP8B1 hydroxylase enzymes in the biosynthetic pathway. Dietary bile acids induced liver damage and restored feedback regulation. A synthetic agonist of the nuclear receptor FXR was not hepatotoxic and had no regulatory effects. Reduction of the bile acid p...

  3. Usefulness and limitations of {sup 99m}Tc-3,3-diphosphono-1,2-propanodicarboxylic acid scintigraphy in the aetiological diagnosis of amyloidotic cardiomyopathy

    Rapezzi, Claudio; Quarta, Candida Cristina; Longhi, Simone; Gallo, Pamela; Gagliardi, Christian; Branzi, Angelo [University of Bologna and Policlinico S. Orsola-Malpighi Hospital, Institute of Cardiology, Bologna (Italy); Guidalotti, Pier Luigi; Pettinato, Cinzia [S. Orsola-Malpighi Hospital, Nuclear Medicine Unit, Bologna (Italy); Leone, Ornella [University of Bologna and S. Orsola-Malpighi Hospital, Department of Pathology, Bologna (Italy); Ferlini, Alessandra [University of Ferrara, Department of Diagnostic and Experimental Medicine, Section of Medical Genetics, Ferrara (Italy); Salvi, Fabrizio [Ospedale Bellaria, Department of Neurology, Bologna (Italy)

    2011-03-15

    We previously reported in a small series of patients that {sup 99m}Tc-3,3-diphosphono-1,2-propanodicarboxylic acid ({sup 99m}Tc-DPD) scintigraphy tested positive in transthyretin-related (TTR) (both mutant and wild-type) but not in primary (AL) amyloidotic cardiomyopathy (AC). We extended our study to a larger cohort of patients with AC. We evaluated (1) 45 patients with TTR-related AC (28 mutant and 17 wild-type), (2) 34 with AL-related AC and (3) 15 non-affected controls. Myocardial uptake of {sup 99m}Tc-DPD (740 MBq i.v.) was semiquantitatively and visually assessed at 5 min and at 3 h. Heart retention (HR) and heart to whole-body retention ratio (H/WB) of late {sup 99m}Tc-DPD uptake were higher among TTR-related AC (HR 7.8%; H/WB 10.4) compared with both unaffected controls (HR 3.5%; H/WB 5.7; p < 0.0001) and AL-related AC (HR 4.0%; H/WB 6.1; p < 0.0001). For the diagnosis of TTR-related AC, positive and negative predictive accuracy of visual scoring of cardiac retention were: 80 and 100% (visual score {>=}1); 88 and 100% (visual score {>=}2); and 100 and 68% (visual score = 3). At adjusted linear regression analysis, TTR aetiology turned out to be the only positive predictor of increasing {sup 99m}Tc-DPD uptake in terms of both HR [{beta} 2.5, 95% confidence interval (CI) 1.5-3.5; p < 0.0001] and H/WB ({beta} 3.5, 95% CI 2.1-4.9; p < 0.0001). While {sup 99m}Tc-DPD scintigraphy was confirmed to be useful for differentiating TTR from AL-related AC, diagnostic accuracy was lower than previously reported due to a mild degree of tracer uptake in about one third of AL patients. {sup 99m}Tc-DPD scintigraphy can provide an accurate differential diagnosis in cases of absent or intense uptake evaluated by visual score. (orig.)

  4. Transgenic increase in N-3/n-6 Fatty Acid ratio reduces maternal obesity-associated inflammation and limits adverse developmental programming in mice.

    Margaret J R Heerwagen

    Full Text Available Maternal and pediatric obesity has risen dramatically over recent years, and is a known predictor of adverse long-term metabolic outcomes in offspring. However, which particular aspects of obese pregnancy promote such outcomes is less clear. While maternal obesity increases both maternal and placental inflammation, it is still unknown whether this is a dominant mechanism in fetal metabolic programming. In this study, we utilized the Fat-1 transgenic mouse to test whether increasing the maternal n-3/n-6 tissue fatty acid ratio could reduce the consequences of maternal obesity-associated inflammation and thereby mitigate downstream developmental programming. Eight-week-old WT or hemizygous Fat-1 C57BL/6J female mice were placed on a high-fat diet (HFD or control diet (CD for 8 weeks prior to mating with WT chow-fed males. Only WT offspring from Fat-1 mothers were analyzed. WT-HFD mothers demonstrated increased markers of infiltrating adipose tissue macrophages (P<0.02, and a striking increase in 12 serum pro-inflammatory cytokines (P<0.05, while Fat1-HFD mothers remained similar to WT-CD mothers, despite equal weight gain. E18.5 Fetuses from WT-HFD mothers had larger placentas (P<0.02, as well as increased placenta and fetal liver TG deposition (P<0.01 and P<0.02, respectively and increased placental LPL TG-hydrolase activity (P<0.02, which correlated with degree of maternal insulin resistance (r = 0.59, P<0.02. The placentas and fetal livers from Fat1-HFD mothers were protected from this excess placental growth and fetal-placental lipid deposition. Importantly, maternal protection from excess inflammation corresponded with improved metabolic outcomes in adult WT offspring. While the offspring from WT-HFD mothers weaned onto CD demonstrated increased weight gain (P<0.05, body and liver fat (P<0.05 and P<0.001, respectively, and whole body insulin resistance (P<0.05, these were prevented in WT offspring from Fat1-HFD mothers. Our results

  5. Earthworms accumulate alanine in response to drought.

    Holmstrup, Martin; Slotsbo, Stine; Henriksen, Per G; Bayley, Mark

    2016-09-01

    Earthworms have ecologically significant functions in tropical and temperate ecosystems and it is therefore important to understand how these animals survive during drought. In order to explore the physiological responses to dry conditions, we simulated a natural drought incident in a laboratory trial exposing worms in slowly drying soil for about one month, and then analyzed the whole-body contents of free amino acids (FAAs). We investigated three species forming estivation chambers when soils dry out (Aporrectodea tuberculata, Aporrectodea icterica and Aporrectodea longa) and one species that does not estivate during drought (Lumbricus rubellus). Worms subjected to drought conditions (drought level. These results suggest that the accumulation of alanine is an important adaptive trait in drought tolerance of earthworms in general. PMID:27107492

  6. Metabolic adaptation in transplastomic plants massively accumulating recombinant proteins.

    Julia Bally

    Full Text Available BACKGROUND: Recombinant chloroplasts are endowed with an astonishing capacity to accumulate foreign proteins. However, knowledge about the impact on resident proteins of such high levels of recombinant protein accumulation is lacking. METHODOLOGY/PRINCIPAL FINDINGS: Here we used proteomics to characterize tobacco (Nicotiana tabacum plastid transformants massively accumulating a p-hydroxyphenyl pyruvate dioxygenase (HPPD or a green fluorescent protein (GFP. While under the conditions used no obvious modifications in plant phenotype could be observed, these proteins accumulated to even higher levels than ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco, the most abundant protein on the planet. This accumulation occurred at the expense of a limited number of leaf proteins including Rubisco. In particular, enzymes involved in CO(2 metabolism such as nuclear-encoded plastidial Calvin cycle enzymes and mitochondrial glycine decarboxylase were found to adjust their accumulation level to these novel physiological conditions. CONCLUSIONS/SIGNIFICANCE: The results document how protein synthetic capacity is limited in plant cells. They may provide new avenues to evaluate possible bottlenecks in recombinant protein technology and to maintain plant fitness in future studies aiming at producing recombinant proteins of interest through chloroplast transformation.

  7. Inhibition of Fat Accumulation by Hesperidin in Caenorhabditis elegans.

    Peng, Huimin; Wei, Zhaohan; Luo, Hujie; Yang, Yiting; Wu, Zhengxing; Gan, Lu; Yang, Xiangliang

    2016-06-29

    Hesperidin, abundant in citrus fruits, has a wide range of pharmacological effects, including anticarcinogenic, anti-inflammatory, antioxidative, radioprotective, and antiviral activities. However, relatively few studies on the effects of hesperidin on lipid metabolism have been reported. Here, using Caenorhaditis elegans as a model animal, we found that 100 μM hesperidin significantly decreased fat accumulation in both high-fat worms cultured in nematode growth medium containing 10 mM glucose (83.5 ± 1.2% versus control by Sudan Black B staining and 87.6 ± 2.0% versus control by Oil Red O staining; p acid/stearic acid (C18:1Δ9/C18:0) (p acid could restore the inhibitory effect of hesperidin on fat accumulation. Hesperidin significantly downregulated the expression of stearoyl-CoA desaturase, fat-6, and fat-7 (p < 0.05), and mutation of fat-6 and fat-7 reversed fat accumulation inhibited by hesperidin. In addition, hesperidin decreased the expression of other genes involved in lipid metabolism, including pod-2, mdt-15, acs-2, and kat-1 (p < 0.05). These results suggested that hesperidin reduced fat accumulation by affecting several lipid metabolism pathways, such as fat-6 and fat-7. This study provided new insights into elucidating the mechanism underlying the regulation of lipid metabolism by hesperidin. PMID:27267939

  8. Quench limits

    With thirteen beam induced quenches and numerous Machine Development tests, the current knowledge of LHC magnets quench limits still contains a lot of unknowns. Various approaches to determine the quench limits are reviewed and results of the tests are presented. Attempt to reconstruct a coherent picture emerging from these results is taken. The available methods of computation of the quench levels are presented together with dedicated particle shower simulations which are necessary to understand the tests. The future experiments, needed to reach better understanding of quench limits as well as limits for the machine operation are investigated. The possible strategies to set BLM (Beam Loss Monitor) thresholds are discussed. (author)

  9. Accumulation of mercury in fish

    In model experiments the direct uptake (excluding the food chain) of different dissolved mercury compounds by female species of Poecilia reticulata was investigated using the radiochemical tracer method. Hg-203 labelled Hg(NO3)2 and CH3HgCl were dissolved in deionized water resulting in concentrations of 0.1/1/5/10 and 20 ng Hg/ml H2O. The fish were measured in vivo using a 3'' x 3'' NaI(Tl) well-type-detector. The experiments showed, that the accumulation rate (ng Hg/g/sub fi/. d) depends very much on the chemical form and the concentration of the dissolved Hg-compound. The accumulation in a CH3HgCl-solution is about four times as fast as in a Hg(NO3)2- solution. In the presence of complexing agents the accumulation rates decrease whereas the accumulation rates increase with increasing Hg-concentration in the water. The release of incorporated methylmercury has a half life of about 69 days. For inorganic mercury a two step mechanism has been found with half lives of 4 days and 68 days, respectively. The relative amount of mercury released in the second step increases with increasing time of incorporation. This indicates the methylation of inorganic mercury in the fish

  10. Pension funds and capital accumulation

    Belan, Pascal; Michel, Philippe; Wigniolle, Bertrand

    2001-01-01

    This note presents a model in which pension funds, by holding a signifiant share of capital assets, can exert a non competitive behavior on labor market. This leads to lower wages and higher capital returns, and can reduce capital accumulation and Long-run welfare.

  11. Strategic Feeding of Ammonium and Metal Ions for Enhanced GLA-Rich Lipid Accumulation in Cunninghamella bainieri 2A1

    Shuwahida Shuib

    2014-01-01

    Full Text Available Strategic feeding of ammonium and metal ions (Mg2+, Mn2+, Fe3+, Cu2+, Ca2+, Co2+, and Zn2+ for enhanced GLA-rich lipid accumulation in C. bainieri 2A1 was established. When cultivated in nitrogen-limited medium, the fungus produced up to 30% lipid (g/g biomass with 12.9% (g/g lipid GLA. However, the accumulation of lipid stopped at 48 hours of cultivation although glucose was abundant. This event occurred in parallel to the diminishing activity of malic enzyme (ME, fatty acid synthase (FAS, and ATP citrate lyase (ACL as well as the depletion of metal ions in the medium. Reinstatement of the enzymes activities was achieved by feeding of ammonium tartrate, but no increment in the lipid content was observed. However, increment in lipid content from 32% to 50% (g/g biomass with 13.2% GLA was achieved when simultaneous feeding of ammonium, glucose, and metal ions was carried out. This showed that the cessation of lipid accumulation was caused by diminishing activities of the enzymes as well as depletion of the metal ions in the medium. Therefore, strategic feeding of ammonium and metal ions successfully reinstated enzymes activities and enhanced GLA-rich lipid accumulation in C. bainieri 2A1.

  12. Metabolic engineering of Yarrowia lipolytica for itaconic acid production.

    Blazeck, John; Hill, Andrew; Jamoussi, Mariam; Pan, Anny; Miller, Jarrett; Alper, Hal S

    2015-11-01

    Itaconic acid is a naturally produced organic acid with diverse applications as a replacement for petroleum derived products. However, its industrial viability as a bio-replacement has been restricted due to limitations with native producers. In this light, Yarrowia lipolytica is an excellent potential candidate for itaconic acid production due to its innate capacity to accumulate citric acid cycle intermediates and tolerance to lower pH. Here, we demonstrate the capacity to produce itaconic acid in Y. lipolytica through heterologous expression of the itaconic acid synthesis enzyme, resulting in an initial titer of 33 mg/L. Further optimizations of this strain via metabolic pathway engineering, enzyme localization, and media optimization strategies enabled 4.6g/L of itaconic acid to be produced in bioreactors, representing a 140-fold improvement over initial titer. Moreover, these fermentation conditions did not require additional nutrient supplementation and utilized a low pH condition that enabled the acid form of itaconic acid to be produced. Overall yields (0.058 g/g yield from glucose) and maximum productivity of 0.045 g/L/h still provide areas for future strain improvement. Nevertheless, this work demonstrates that Y. lipolytica has the potential to serve as an industrially relevant platform for itaconic acid production. PMID:26384571

  13. Limited Neutrality

    Nielsen, Morten Ebbe Juul

    2006-01-01

    Article Concerning the prospect of a kind of limited neutrality in place of the standard liberal egalitarian "neutrality of justification."......Article Concerning the prospect of a kind of limited neutrality in place of the standard liberal egalitarian "neutrality of justification."...

  14. Dose limits

    The dose limit is defined to be the level of harmfulness which must not be exceeded, so that an activity can be exercised in a regular manner without running a risk unacceptable to man and the society. The paper examines the effects of radiation categorised into stochastic and non-stochastic. Dose limits for workers and the public are discussed

  15. Biodegradation of poly(lactic acid, poly(hydroxybutyrate-co-hydroxyvalerate, poly(butylene succinate and poly(butylene adipate-co-terephthalate under anaerobic and oxygen limited thermophilic conditions

    Jutakan Boonmee

    2016-01-01

    Full Text Available In order to study the biodegradation behavior of biodegradable plastics in landfill conditions, four types of biodegradable plastics including poly(lactic acid (PLA, poly(hydroxybutyrate-co-hydroxyvalerate (PHBV, poly(butylene succinate (PBS, and poly(butylene adipate-co-terephthalate (PBAT were tested by burying in sludge mixed soil medium under anaerobic and oxygen limited conditions. The experiments were operated at 52 ± 2ºC in dark conditions according to ISO15985. The degree of biodegradation after 75 days was investigated by weight loss determination, visual examination, and surface appearance by scanning electronic microscopy (SEM. Under both anaerobic and oxygen limited conditions, the complete degradation (100% weight loss was found only in PHBV after 75 days. The plastic degradations were ranked in the order of PHBV> PLA> PBS> PBAT. The percentage of weight losses were significantly different at p ≤ 0.05. However, for all studied plastics, the degradation under anaerobic and oxygen limited conditions did not significantly different at 95% confidence.

  16. Survival strategies of polyphosphate accumulating organisms and glycogen accumulating organisms under conditions of low organic loading.

    Carvalheira, Mónica; Oehmen, Adrian; Carvalho, Gilda; Reis, Maria A M

    2014-11-01

    Enhanced biological phosphorus removal (EBPR) is usually limited by organic carbon availability in wastewater treatment plants (WWTPs). Polyphosphate accumulating organisms (PAOs) and glycogen accumulating organisms (GAOs) were operated under extended periods with low organic carbon loading in order to examine its impact on their activity and survival. The decrease in organic carbon load affected PAOs and GAOs in different ways, where the biomass decay rate of GAOs was approximately 4times higher than PAOs. PAOs tended to conserve a relatively high residual concentration of polyhydroxyalkanoates (PHAs) under aerobic conditions, while GAOs tended to deplete their available PHA more rapidly. This slower oxidation rate of PHA by PAOs at residual concentration levels enabled them to maintain an energy source for aerobic maintenance processes for longer than GAOs. This may provide PAOs with an advantage over GAOs in surviving the low organic loading conditions commonly found in full-scale wastewater treatment plants. PMID:25270044

  17. R-acetoin accumulation and dissimilation in Klebsiella pneumoniae.

    Wang, Dexin; Zhou, Jidong; Chen, Chuan; Wei, Dong; Shi, Jiping; Jiang, Biao; Liu, Pengfu; Hao, Jian

    2015-08-01

    Klebsiella pneumoniae is a 2,3-butanediol producer, and R-acetoin is an intermediate of 2,3-butanediol production. R-acetoin accumulation and dissimilation in K. pneumoniae was studied here. A budC mutant, which has lost 2,3-butanediol dehydrogenase activity, accumulated high levels of R-acetoin in culture broth. However, after glucose was exhausted, the accumulated R-acetoin could be reused by the cells as a carbon source. Acetoin dehydrogenase enzyme system, encoded by acoABCD, was responsible for R-acetoin dissimilation. acoABCD mutants lost the ability to grow on acetoin as the sole carbon source, and the acetoin accumulated could not be dissimilated. However, in the presence of another carbon source, the acetoin accumulated in broth of acoABCD mutants was converted to 2,3-butanediol. Parameters of R-acetoin production by budC mutants were optimized in batch culture. Aerobic culture and mildly acidic conditions (pH 6-6.5) favored R-acetoin accumulation. At the optimized conditions, in fed-batch fermentation, 62.3 g/L R-acetoin was produced by budC and acoABCD double mutant in 57 h culture, with an optical purity of 98.0 %, and a substrate conversion ratio of 28.7 %. PMID:26059458

  18. Specific fatty acids as metabolic modulators in the dairy cow

    J.A.A. Pires

    2008-07-01

    Full Text Available This review summarizes recent developments on the utilization of specific fatty acids to modulate bovine energy metabolism, with emphasis on the periparturient dairy cow. A number of experiments have assessed the effects of polyunsaturated fatty acids on bovine hepatic energy metabolism using in vitro and in vivo models. Treatment of hepatocytes with specific fatty acids altered energy metabolism in vitro. For example, linolenic acid seemed to decrease hepatocyte triacylglycerol accumulation. This effect was confirmed in vivo, using parenteral infusions of emulsions derived from different fat sources to feed-restricted non-lactating cows. Additionally, polyunsaturated fatty acids can increase whole body response to insulin, potentially enhancing antilipolytic effects of insulin and muscle protein anabolism in the bovine. There is limited literature on the effects of feeding fat sources rich in omega-3 polyunsaturated fatty acids, such as fish oil and linseed oil, on metabolism of periparturient dairy cows. Available research has yielded conflicting results which need further clarification. On the other hand, specific isomers of conjugated linoleic acid consistently induce milk fat depression and are able to decrease energy export in milk by periparturient dairy cows. Nonetheless, research is still needed to assess whether these effects will ultimately benefit productivity and health status of periparturient dairy cows. Limitations of available methods to protect fatty acids from ruminal biohydrogenation are also addressed.

  19. PAEs胁迫对高/低累积品种水稻根系形态及根系分泌低分子有机酸的影响%Effects of PAE Stress on Root Morphology andLow Molecular Weight Organic Acid (LMWOC) in Root Exudates of Rice (Oryza sativa L.) Cultivars with High- and Low-PAE Accumulation

    陈桐; 蔡全英; 吴启堂; 吕辉雄; 曾巧云; 李慧

    2015-01-01

    以前期筛选获得的邻苯二甲酸酯(PAEs)高/低累积基因型水稻(Oryza sativa L.)品种(培杂泰丰/丰优丝苗)进行水培试验,分别于分蘖期和拔节期采集样品,采用根系扫描仪分析根系形态学特性、高效液相色谱法测定根系分泌物中低分子有机酸成分,以及采用气相色谱-质谱仪(GC-MS)测定水稻根、茎、叶中 PAEs 质量分数。对比研究两种基因型水稻的根系形态特征和根系分泌物(低分子有机酸)的差异,初步探讨两种基因型水稻吸收累积PAEs差异原因,为保障农产品质量安全提供科学依据。结果表明,随着培养液中PAEs质量浓度增加,两种基因型水稻总根长、根表面积和根体积先增大后减小;相同PAEs质量浓度下,高累积型品种培杂泰丰根系形态指标大多高于丰优丝苗。两种水稻体内的PAEs质量分数均随污染物浓度增大而升高,高PAEs水平(80 mg·L-1)处理是低PAEs水平(20 mg·L-1)处理的3.8~7.3倍(邻苯二甲酸二丁酯(DBP))和2.7~20.4倍(邻苯二甲酸二(2-乙基己基)酯(DEHP)),培杂泰丰高于丰优丝苗。植物体内DBP和DEHP质量分数呈现根>叶≥茎。分蘖期两种水稻体内DBP和DEHP质量分数高于拔节期,且与营养液中PAEs的质量浓度呈显著相关,但拔节期的相关程度减弱。拔节期两种水稻根系分泌物中低分子有机酸质量浓度随培养液中PAEs质量浓度升高呈现不同的变化规律,但二者草酸质量浓度均增加(在1.11~8.13 mg·L-1之间),并与根系中DBP和DEHP的质量分数呈显著正相关。说明PAEs胁迫会影响水稻根系形态和低分子有机酸分泌,进而影响水稻对PAEs的吸收累积。%Two different genotypic cultivars of rice (Oryza sativa L.) with PAE (phthalic acid esters) high-accumulation (cultivar Peizataifeng) and low-accumulation (cultivar Fengyousimiao), were grown in hydroponic

  20. High Threshold for Lead Accumulators Helps the Battery Industry to Recover in Q2

    2012-01-01

    <正>Along with release of relevant access conditions of the lead acid accumulator industry and increasing popularity of new-type batteries including lithium battery and lead-carbon battery, etc., the battery industry recovered in the first

  1. Stearic Acid

    Young, Jay A.

    2004-01-01

    A chemical laboratory information profile (CLIP) is presented for the chemical, stearic acid. The profile lists the chemical's physical and harmful characteristics, exposure limits, and symptoms of major exposure, for the benefit of teachers and students, who use the chemical in the laboratory.

  2. Neurodegeneration with Brain Iron Accumulation: An Overview

    Seyed Hassan TONEKABONI*

    2014-12-01

    Full Text Available How to Cite This Article: Tonekaboni SH, Mollamohammadi M. Neurodegeneration with Brain Iron Accumulation: An Overview. Iran J Child Neurol. 2014 Autumn;8(4: 1-8.AbstractObjectiveNeurodegeneration with brain iron accumulation (NBIA is a group of neurodegenerative disorder with deposition of iron in the brain (mainly Basal Ganglia leading to a progressive Parkinsonism, spasticity, dystonia, retinal degeneration, optic atrophy often accompanied by psychiatric manifestations and cognitive decline. 8 of the 10 genetically defined NBIA types are inherited as autosomal recessive and the remaining two by autosomal dominant and X-linked dominant manner. Brain MRI findings are almost specific and show abnormal brain iron deposition in basal ganglia some other related anatomicallocations. In some types of NBIA cerebellar atrophy is the major finding in MRI.ReferencesShevel M. Racial hygiene, activeeuthanasia, and Julius Hallervorden. Neurology 1992;42:2214-2219.HayflickSJ. Neurodegeneration with brain Iron accumulation: from genes to pathogenesis.Semin Pediatr Neurol 2006;13:182-185.Zhou B, Westawy SK, Levinson B, et al. A novel pantothenate kinase gene(PANK2 is defective in Hallervorden-Spatzsyndrome. Nat Genet 2001;28:345- 349.www.ncbi.nlm.nihgov/NBK111Y/university of Washington, seattle. Allison Gregory and Susan Hayflick.Paisan-Ruiz C, Li A, Schneider SA, et al. Widesread Levy body and tau accumulation in childhood and adult onset dystonia-parkinsonism cases with PLA2G6 mutations. Neurobiol Aging 2012;33:814-823.Dick KJ, Eckhardt M, Paison-Ruiz C, et al. Mutation of FA2H underlies a complicated form of hereditary spastic paraplegia(SPG 35. Hum Mutat 31: E1251-E1260.Edvardson S, Hama H, Shaag A, et al. Mutation in the fatty acid 2-Hydroxylase gene are associated with leukodystrophy with spastic paraparesis and dystonia. Am I Hum Genet 2008;83:647-648.Schneider SA, Aggarwal A, Bhatt m, et al. Severe tongue protrusion dystonia: clinical syndromes

  3. Accumulation of humic acid in DET/DGT gels

    Van der Veeken, P.L.R.; Chakraborty, P.; Van Leeuwen, H.P.

    Gel layer based sensors are increasingly employed for dynamic trace metal speciation analysis in aquatic and soil media. In DGT (Diffusive Gradient in Thin film), polyacrylamide hydrogels are commonly used for the diffusive gel layer. While some...

  4. Docosahexaenoic acid accumulation in hraustochytrids: Search for the rationale

    Jain, R.; Raghukumar, S.; Sambaiah, K.; Kumon, Y.; Nakahara, T.

    with increased lipids and DHA showed higher specific gravities than nonrefrigerated cells. The following roles are suggested for storage lipids and DHA in thraustochytrids: (1) lipids serve as energy sources during movement of cells and for production of EN; (2...

  5. A Systematic Analysis of Coal Accumulation Process

    CHENG Aiguo

    2008-01-01

    Formation of coal seam and coal-rich zone is an integrated result of a series of factors in coal accumulation process. The coal accumulation system is an architectural aggregation of coal accumulation factors. It can be classified into 4 levels: the global coal accumulation super-system, the coal accumulation domain mega.system, the coal accumulation basin system, and the coal seam or coal seam set sub-system. The coal accumulation process is an open, dynamic, and grey system, and is meanwhile a system with such natures as aggregation, relevance, entirety, purpose-orientated, hierarchy, and environment adaptability. In this paper, we take coal accumulation process as a system to study origin of coal seam and coal-rich zone; and we will discuss a methodology of the systematic analysis of coal accumulation process. As an example, the Ordos coal basin was investigated to elucidate the application of the method of the coal accumulation system analysis.

  6. Crises and human capital accumulation

    Freddy Heylen; Lorenzo Pozzi

    2007-01-01

    This paper studies the effects of crises on human capital formation. Theoretically, a crisis undermines total factor productivity, which reduces the return to working and to accumulating physical capital. If the crisis is temporary, young agents will study now and work later. Human capital rises. To test our model we rely on inflation crises as our main empirical proxy. Using GMM panel procedures, our analysis for 86 countries in 1970-2000 confirms the positive effects of crises on human capi...

  7. Debt Redemption and Reserve Accumulation

    Laura Alfaro; Fabio Kanczuk

    2013-01-01

    Foreign participation in local-currency bond markets in emerging countries has increased dramatically over the past decade. In light of this trend, we revisit sovereign debt sustainability and incentives to default when the sovereign is temporarily excluded from capital markets. Differently from previous analyses, we assume that in addition to accumulating international reserves, countries can borrow internationally using their own currency. As opposed to traditional sovereign debt models (al...

  8. Limiting Skepticism

    Hendricks, Vincent Fella; Symons, John

    2011-01-01

    Skeptics argue that the acquisition of knowledge is impossible given the standing possibility of error. We present the limiting convergence strategy for responding to skepticism and discuss the relationship between conceivable error and an agent’s knowledge in the limit. We argue that the skeptic...... must demonstrate that agents are operating with a bad method or are in an epistemically cursed world. Such demonstration involves a significant step beyond conceivability and commits the skeptic to potentially convergent inquiry...

  9. 氯霉素水杨酸搽剂微生物限度检查方法的验证%Verification of the Method to Determine the Microbial Limit Test for Chloramphenicol Salicylic Acid Liniment

    邓菲; 宋莹

    2014-01-01

    Objective To establish a method to determine the microbial limit test for Chloramphenicol salicylic acid liniment. Method According to China Pharmcopoeia edition 2010,the antimicrobial effect of Chloramphenicol salicylic acid liniment was determined by recovery rate with 5 control trains.Result Antibacterial effect was not found against escherichia coli,bacillus subtilis,staphylococcus aureus,Candida albicans and Aspergillus niger.Conventional method was used for counting bacteria. Conclusion The method is sample and it can be used for qualitity control of Chloramphenicol salicylic acid liniment.%目的:建立氯霉素水杨酸搽剂的微生物限度检查方法。方法参照《中国药典》2010版,采用5种阳性对照菌回收率试验测定其是否含抑菌成分。结果该品种对大肠埃希菌、枯草芽孢杆菌、金黄色葡萄球菌、白色念珠菌和黑曲霉均没有抑菌活性,细菌、霉菌和酵母菌数及控制菌的检查采用常规法进行。结论用该方法进行微生物限度检查可以客观地反映药物中微生物的污染状况,可用于该制剂微生物控制。

  10. Glyphosate accumulation, translocation, and biological effects in Coffea arabica after single and multiple exposures

    Schrübbers, Lars Christoph; Valverde, Bernal E.; Strobel, Bjarne W.;

    2016-01-01

    In perennial crops like coffee, glyphosate drift exposure can occur multiple times during its commercial life span. Due to limited glyphosate degradation in higher plants, a potential accumulation of glyphosate could lead to increased biological effects with increased exposure frequency. In this...... study, we investigated glyphosate translocation over time, and its concentration and biological effects after single and multiple simulated spray-drift exposures. Additionally, shikimic acid/glyphosate ratios were used as biomarkers for glyphosate binding to its target enzyme.Four weeks after the...... exposure, glyphosate was continuously translocated. Shikimic acid levels were lin-ear correlated with glyphosate levels. After two months, however, glyphosate appeared to have reduced activity. In the greenhouse, multiple applications resulted in higher internal glyphosate concentrations.The time of...

  11. Echium oil: A valuable source of n-3 and n-6 fatty acids

    MIR Miquel

    2008-07-01

    Full Text Available Echium oil is a vegetable oil of non-GMO plant origin extracted from the seeds of Echium plantagineum containing significant amounts of omega-3 fatty acid Stearidonic Acid (SDA and omega-6 acid γ-linolenic acid (GLA. Typical fatty acid composition of Echium oil is: Oleic acid (18:1 n-9 16%, Linoleic acid (LA, 18:2 n-6 19%, γ-linolenic acid (GLA, 18:3 n-610%, α-linolenic acid (ALA, 18:3 n-3 30% and Stearidonic acid (SDA, 18:4 n-3 13%. This natural ratio of fatty acids, trough their metabolism, deliver enhanced plasma concentrations of eicosapentaenoic (EPA, 20:5 n-3, docosapentaenoic (DPA, 22:5 n-3 and dihomo-γ-linolenic (DGLA, 20:3 n-6 acids without increasing the concentrations of arachidonic acid (AA, 20:4 n-6. GLA is commonly associated with the anti-inflammatory effects of oils such as evening primrose oil and borage oil. Supplementation with GLA can markedly increase serum AA with subsequent pro-inflammatory effects. The presence of stearidonic acid in echium oil prevents the accumulation of serum AA and AA-derived eicosanoids without preventing the accumulation of DGLA which is the real n-6 precursor of anti-inflammatory eicosanoids. SDA is an intermediate in the biosynthetic conversion of ALA to EPA. As SDA is the product of the rate-limiting ∆6-desaturase step and due the efficiency of the elongase and ∆5-desaturase steps, SDA is readily converted to EPA. SDA has the physiologic benefits of EPA, for instance, lowering the serum triglycerides in hypertriglyceridemic subjects. Therefore echium oil is a true alternative for vegetarians or those who do not eat fish, to benefit from the anti-inflammatory effects of omega-3 and omega-6 long chain polyunsaturated fatty acids.

  12. Field shape of the accumulator LDA dipoles

    Large Aperture Dipoles (LDA) are used in the Fermilab Antiproton Accumulator to provide one half of the bending required for that storage ring. The production measurement data for those magnets are analyzed and the integrated field shape on the median plane at the design operating current (1,180 A) is reported. When linear (quadrupole) and parabolic (sextupole) terms are subtracted, the remaining field errors are only ∼10-4 over a ±4 inch aperture. Polynomial fits to that data can be interpreted in terms of normal harmonics of the magnetic field. However the polynomial fits are not unique. When the polynomial coefficients are expressed as harmonics with a reference radius of 1 inch, the nonlinear portions of this field (harmonics higher than quadrupole) are typically 10-5 to 10-6. Both individual magnet results and statistical profiles are reported along with studies of the fitting limitations

  13. Field shape of the accumulator LDA dipoles

    Brown, B.C.

    1996-05-01

    Large Aperture Dipoles (LDA) are used in the Fermilab Antiproton Accumulator to provide one half of the bending required for that storage ring. The production measurement data for those magnets are analyzed and the integrated field shape on the median plane at the design operating current (1,180 A) is reported. When linear (quadrupole) and parabolic (sextupole) terms are subtracted, the remaining field errors are only {approximately}10{sup {minus}4} over a {+-}4 inch aperture. Polynomial fits to that data can be interpreted in terms of normal harmonics of the magnetic field. However the polynomial fits are not unique. When the polynomial coefficients are expressed as harmonics with a reference radius of 1 inch, the nonlinear portions of this field (harmonics higher than quadrupole) are typically 10{sup {minus}5} to 10{sup {minus}6}. Both individual magnet results and statistical profiles are reported along with studies of the fitting limitations.

  14. Acidizing carbonate reservoirs with chlorocarboxylic acid salt solutions

    Richardson, E.A.; Scheuerman, R.F.; Templeton, C.C.

    1978-10-31

    A carbonate reservoir is acidized slowly by injecting an aqueous solution of a chlorocarboxylic acid salt so that the rate of the acidization is limited to the rate at which an acid is formed by the hydrolyzing of the chlorocarboxylate ions. The rate at which a chlorocarboxylic acid salt hydrolyzes to form an acid provides the desired rate of acid-release. A more complete acid-base reaction by chloroacetic acid, as compared to formic, acetic, and proprionic, is due to its being a much stronger acid. The pKa of chloroacetic acid is 2.86, whereas that of formic acid is 3.75, and that of acetic acid is 4.75. The pKa of a solution of a weak acid is the pH exhibited when the concentration of undissociated acid equals the concentration of the acid anion. 14 claims.

  15. Psoralen induced bile acid accumulation and cytotoxicity by inhibiting MRP2 and MRP3 in HepG2 cells%异补骨脂素抑制MRP2、MRP3所致的HepG2细胞内胆汁酸蓄积和毒性

    周昆; 毕亚男; 史红

    2015-01-01

    Aim To investigate the toxicity of isopsor-alen in HepG2 cells and its effects on bile acid, bile acid synthesis and transport. Methods Cell viability was evaluated by MTT assay and bile acid was deter-mined inside HepG2 cells, with exposure to various isopsoralen for 24h. The mRNA transcription of BSEP, MRP2, MRP3, NTCP, OATP2, OSTα, CYP7A1, CYP27 A1 , FXR and PXR were assessed by real-time PCR. Results The cell viability was decreased dose-dependently with isopsoralen in HepG2 cells, and IC50 was 118. 1μmol·L-1 exposure to isopsoralen for 24h. Bile acid inside cells significantly increased with 100 and 400 μmol · L-1 isopsoralen. Isopsoralen caused the down-regulation of MRP2 , MRP3 , CYP7 A1 mRNA at 25 μmol · L-1 . Beside these, the up-regulation of OATP2,OSTα,CYP27A1,FXR,PXR with 100 μmol· L-1 isopsoralen, but there was no significant change of BSEP and NTCP. Conclusion The results show that isopsoralen induces bile acid accumulation and cytotox-icity which may be associated with the down-regulation of MRP2, MRP3 in HepG2 cells.%目的:观察异补骨脂素体外对HepG2细胞毒性和细胞内胆汁酸浓度的影响,并考察其对胆汁酸合成转运的影响。方法不同浓度异补骨脂素在HepG2细胞作用24 h, MTT法检测细胞存活,并检查细胞内胆汁酸浓度。常规TRIzol法提取RNA,real time PCR检测细胞中转运体BSEP、MRP2、 MRP3、 OATP2、 NTCP、 OSTα,合成酶 CYP7A1、CYP27A1和受体 FXR、PXR 的 mRNA 转录水平。结果HepG2细胞存活率随着异补骨脂素浓度升高而剂量依赖性的降低,异补骨脂素作用24 h的IC50为118.1μmol·L-1。100、400μmol·L-1异补骨脂素可使细胞内胆汁酸浓度明显升高。异补骨脂素在25μmol·L-1时就可使MRP2、MRP3、CYP7A1明显降低,当浓度增大到100μmol · L-1时, OATP2、OSTα、CYP27A1、FXR、PXR 也明显升高,但 BSEP、NTCP差异无显著性。结论异补骨脂素可引起HepG2细胞内胆汁酸升高和细胞

  16. Accumulation of cobalt by cephalopods

    Accumulation of cobalt by cephalopod mollusca was investigated by radiotracer experiments and elemental analysis. In the radiotracer experiments, Octopus vulgaris took up cobalt-60 from seawater fairly well and the concentration of the nuclide in whole body attained about 150 times the level of seawater at 25th day at 200C. Among the tissues and organs measured, branchial heart which is the specific organ of cephalopods showed the highest affinity for the nuclide. The organ accumulated about 50% of the radioactivity in whole body in spite of its little mass as 0.2% of total body weight. On the other hand, more than 90% of the radioactivity taken up from food (soft parts of Gomphina melanaegis labelled with cobalt-60 previously in an aquarium) was accumulated in liver at 3rd day after the single administration and then the radioactivity in the liver seemed to be distributed to other organs and tissues. The characteristic elution profiles of cobalt-60 was observed for each of the organs and tissues in Sephadex gel-filtration experiment. It was confirmed by the gel-filtration that most of cobalt-60 in the branchial heart was combined with the constituents of low molecular weights. The average concentration of stable cobalt in muscle of several species of cephalopods was 5.3 +- 3.0 μg/kg wet and it was almost comparable to the fish muscle. On the basis of soft parts, concentration of the nuclide closed association among bivalve, gastropod and cephalopod except squid that gave lower values than the others. (author)

  17. Lysosomal Cholesterol Accumulation Sensitizes To Acetaminophen Hepatotoxicity by Impairing Mitophagy

    Baulies, Anna; Ribas, Vicent; Núñez, Susana; Torres, Sandra; Alarcón-Vila, Cristina; Martínez, Laura; Suda, Jo; Ybanez, Maria D.; Kaplowitz, Neil; García-Ruiz, Carmen; Fernández-Checa, Jose C.

    2015-01-01

    The role of lysosomes in acetaminophen (APAP) hepatotoxicity is poorly understood. Here, we investigated the impact of genetic and drug-induced lysosomal cholesterol (LC) accumulation in APAP hepatotoxicity. Acid sphingomyelinase (ASMase)−/− mice exhibit LC accumulation and higher mortality after APAP overdose compared to ASMase+/+ littermates. ASMase−/− hepatocytes display lower threshold for APAP-induced cell death and defective fusion of mitochondria-containing autophagosomes with lysosomes, which decreased mitochondrial quality control. LC accumulation in ASMase+/+ hepatocytes caused by U18666A reproduces the susceptibility of ASMase−/− hepatocytes to APAP and the impairment in the formation of mitochondria-containing autolysosomes. LC extraction by 25-hydroxycholesterol increased APAP-mediated mitophagy and protected ASMase−/− mice and hepatocytes against APAP hepatotoxicity, effects that were reversed by chloroquine to disrupt autophagy. The regulation of LC by U18666A or 25-hydroxycholesterol did not affect total cellular sphingomyelin content or its lysosomal distribution. Of relevance, amitriptyline-induced ASMase inhibition in human hepatocytes caused LC accumulation, impaired mitophagy and increased susceptibility to APAP. Similar results were observed upon glucocerebrosidase inhibition by conduritol β-epoxide, a cellular model of Gaucher disease. These findings indicate that LC accumulation determines susceptibility to APAP hepatotoxicity by modulating mitophagy, and imply that genetic or drug-mediated ASMase disruption sensitizes to APAP-induced liver injury. PMID:26657973

  18. Active transport and accumulation of bicarbonate by a unicellular cyanobacterium.

    Miller, A G; Colman, B

    1980-09-01

    The rates of inorganic carbon accumulation and carbon fixation in light by the unicellular cyanobacterim Coccohloris peniocystis have been determined. Cells incubated in the light in medium containing H14CO3- were rapidly separated from the medium by centrifugation through silicone oil into a strongly basic terminating solution. Samples of these inactivated cells were assayed to determine total 14C accumulation, and acid-treated samples were assayed to determine 14C fixation. The rate of transport of inorganic into illuminated cells was faster than the rate of CO2 production in the medium from HCO3- dehydration. This evidence for HCO3- transport in these cells is in agreement with our previous results based upon measurements of photosynthetic O2 evolution. A substantial pool of inorganic carbon was bulit up within the cells presumably as HCO3- before the onset of the maximum rate of photosynthesis. Large accumulation ratios were observed, greater than 1,000 times the external HCO3- concentration. Accumulation did not occur in the dark and was greatly suppressed by the photosynthesis inhibitors 3-(3,4-dichlorophenyl)-1,1-dimethyl urea and 3-chloro-carbonylcyanide phenylhydrazone. These results indicate that the accumulation of inorganic carbon in these cells involves a light-dependent active transport process. PMID:6773925

  19. Apolipoprotein E promotes lipid accumulation and differentiation in human adipocytes

    Lasrich, Dorothee; Bartelt, Alexander [Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg (Germany); Grewal, Thomas, E-mail: thomas.grewal@sydney.edu.au [Faculty of Pharmacy A15, The University of Sydney, Sydney, NSW 2006 (Australia); Heeren, Joerg, E-mail: heeren@uke.de [Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg (Germany)

    2015-09-10

    Several studies in mice indicate a role for apolipoprotein E (APOE) in lipid accumulation and adipogenic differentiation in adipose tissue. However, little is yet known if APOE functions in a similar manner in human adipocytes. This prompted us to compare lipid loading and expression of adipocyte differentiation markers in APOE-deficient and control adipocytes using the differentiated human mesenchymal stem cell line hMSC-Tert as well as primary human and mouse adipocytes as model systems. Differentiated hMSC-Tert were stably transduced with or without siRNA targeting APOE while murine adipocytes were isolated from wild type and Apoe knockout mice. Human APOE knockdown hMSC-Tert adipocytes accumulated markedly less triglycerides compared to control cells. This correlated with strongly decreased gene expression levels of adipocyte markers such as adiponectin (ADIPOQ) and fatty acid binding protein 4 (FABP4) as well as the key transcription factor driving adipocyte differentiation, peroxisome proliferator activator receptor gamma (PPARG), in particular the PPARG2 isoform. Similarly, differentiation of murine Apoe-deficient adipocytes was characterized by reduced gene expression of Adipoq, Fabp4 and Pparg. Interestingly, incubation of APOE-deficient hMSC-Tert adipocytes with conditioned media from APOE3-overexpressing adipocytes or APOE-containing Very Low Density Lipoprotein (VLDL) partially restored triglyceride accumulation, but were unable to induce adipocyte differentiation, as judged by expression of adipocyte markers. Taken together, depletion of endogenous APOE in human adipocytes severely impairs lipid accumulation, which is associated with an inability to initiate differentiation. - Highlights: • Immortalized human mesenchymal stem cells were used to study adipocyte development. • Knockdown of endogenous APOE lead to impaired lipid accumulation and adipogenesis. • APOE supplementation partially restored lipid accumulation but not differentiation.

  20. Apolipoprotein E promotes lipid accumulation and differentiation in human adipocytes

    Several studies in mice indicate a role for apolipoprotein E (APOE) in lipid accumulation and adipogenic differentiation in adipose tissue. However, little is yet known if APOE functions in a similar manner in human adipocytes. This prompted us to compare lipid loading and expression of adipocyte differentiation markers in APOE-deficient and control adipocytes using the differentiated human mesenchymal stem cell line hMSC-Tert as well as primary human and mouse adipocytes as model systems. Differentiated hMSC-Tert were stably transduced with or without siRNA targeting APOE while murine adipocytes were isolated from wild type and Apoe knockout mice. Human APOE knockdown hMSC-Tert adipocytes accumulated markedly less triglycerides compared to control cells. This correlated with strongly decreased gene expression levels of adipocyte markers such as adiponectin (ADIPOQ) and fatty acid binding protein 4 (FABP4) as well as the key transcription factor driving adipocyte differentiation, peroxisome proliferator activator receptor gamma (PPARG), in particular the PPARG2 isoform. Similarly, differentiation of murine Apoe-deficient adipocytes was characterized by reduced gene expression of Adipoq, Fabp4 and Pparg. Interestingly, incubation of APOE-deficient hMSC-Tert adipocytes with conditioned media from APOE3-overexpressing adipocytes or APOE-containing Very Low Density Lipoprotein (VLDL) partially restored triglyceride accumulation, but were unable to induce adipocyte differentiation, as judged by expression of adipocyte markers. Taken together, depletion of endogenous APOE in human adipocytes severely impairs lipid accumulation, which is associated with an inability to initiate differentiation. - Highlights: • Immortalized human mesenchymal stem cells were used to study adipocyte development. • Knockdown of endogenous APOE lead to impaired lipid accumulation and adipogenesis. • APOE supplementation partially restored lipid accumulation but not differentiation.

  1. Artificial Neural Network Model of Hydrocarbon Migration and Accumulation

    刘海滨; 吴冲龙

    2002-01-01

    Based on the dynamic simulation of the 3-D structure the sedimentary modeling, the unit entity model has been adopted to transfer the heterogeneous complex pas sage system into limited simple homogeneous entity, and then the traditional dyn amic simulation has been used to calculate the phase and the drive forces of the hyd rocarbon , and the artificial neural network(ANN) technology has been applied to resolve such problems as the direction, velocity and quantity of the hydrocarbo n migration among the unit entities. Through simulating of petroleum migration a nd accumulation in Zhu Ⅲ depression, the complex mechanism of hydrocarbon migra tion and accumulation has been opened out.

  2. Sulfur-accumulating plants convert sulfate salts from soils into environmentally resilient biominerals

    Robson, Thomas; Reid, Nathan; Stevens, Jason; Dixon, Kingsley

    2016-04-01

    Sulfur-accumulator plants (thiophores), which accumulate atypically high sulfur and calcium concentrations in their aerial biomass, may be suitable for revegetating and phytostabilising reactive sulfur-enriched substrates such as mine tailings, acid-sulfate soils and polluted soils. We present biogeochemical insights on thiophores from the Australian Great Sandy Desert, which accumulate up to 40 times as much sulfur (2-5 %S) versus comparator species. X-ray microanalyses revealed this accumulation relates to peculiar gypsum-like mineralisation throughout their foliage, illustrating a mechanism for sulfate removal from soils and sequestration as sparingly soluble biominerals. However, we did not know whether these species treat the excess Ca/S as a waste to be shed with senescent litter and, if so, how resilient these 'biominerals' are to photo-biodegradation once shed and so to what extent the accumulated elements are recycled back into the reactive/bioavailable sulfate reservoir. To address these questions, we sampled four foliage (phyllode) fractions from ten individuals of the thiophore, Acacia bivenosa: healthy mature phyllodes, senescent phyllodes on the branch, recently shed and older, more degraded ground litter. We selected two thiophores (A. bivenosa and A. robeorum) and a non-thiophore (A. ancistrocarpa) for detailed soil/regolith studies. Samples were collected from trenches bisected by each tree, taken from varying depth (20-500 mm) and distance from the stem (0.1-5 m). Dried foliage was cleaned, sectioned for SEM-EDXS examination and elemental compositions of foliage and soils were determined (microwave-assisted acid digestion + ICP-OES/MS). Each species generated a 'halo' of elevated S/Ca in the soil immediately beneath their crowns, although that of A. ancistrocarpa was of minor magnitude. These anomalies were confined to shallow soil (20-50 mm i.e. influenced by litter), suggesting limited S/Ca re-mobilisation from the litter. Foliar elemental

  3. Water Extract of Dolichos lablab Attenuates Hepatic Lipid Accumulation in a Cellular Nonalcoholic Fatty Liver Disease Model.

    Im, A-Rang; Kim, Yun Hee; Lee, Hye Won; Song, Kwang Hoon

    2016-05-01

    Nonalcoholic fatty liver disease (NAFLD) is a common chronic liver disease that is rising in prevalence worldwide. Therapeutic strategies for patients with NAFLD are limited by a lack of effective drugs. In this report, we show that Dolichos lablab water extract (DLL-Ex) protects against free fatty acid (FFA)-induced lipid accumulation and attenuates expression of genes involved in lipid droplet accumulation in cellular NAFLD models. The hepatoprotective effects and underlying mechanism of DLL-Ex were assessed using an in vitro cellular model in which NAFLD was simulated by inducing excessive FFA influx into hepatocytes. HepG2 cells were treated with DLL-Ex and FFAs for 24 h, after which intracellular lipid content was observed by using Nile Red and Oil Red O staining. Quantitative real-time polymerase chain reaction was used to measure expression levels of genes related to FFA-mediated cellular energy depletion. Western blotting was used to measure protein levels of phosphorylated c-Jun N-terminal kinase, AMP-activated protein kinase alpha (AMPKα), and peroxisome proliferator-activated receptor γ coactivator 1 alpha. In HepG2 cells, DLL-Ex inhibited expression of CD36, which regulates fatty acid uptake, as well as BODIPY-labeled fatty acid uptake. Additionally, DLL-Ex significantly attenuated FFA-mediated cellular energy depletion and mitochondrial membrane depolarization. Furthermore, DLL-Ex enhanced phosphorylation of AMPK, indicating that AMPK is a critical regulator of DLL-Ex-mediated inhibition of hepatic lipid accumulation, possibly through its antioxidative effect. These results demonstrate that DLL-Ex exerts potent anti-NAFLD activity, suggesting that it could be a potential adjuvant treatment for patients with NAFLD. PMID:27152979

  4. Screening, Identification and Fermentation Property of a Yeast Strain R6 Accumulating Alpha-ketoglutaric Acid%酵母 R6中α-酮戊二酸的筛选、鉴定和发酵性能的研究

    陈静; 张春杨; 李超

    2015-01-01

    A yeast strain R6 was obtained by the method of thiamine(VB1) auxotroph-ic negative selection from the edible oil-pol uted soil in Zibo, China. Physiological and biochemical experiments revealed that strain R6 shared common feature with Rhodotorula mucilaginosa according to the API 20 C AUX yeast identification sys-tem which has been tested previously. Furthermore, the 18S rDNA gene of strain R6 was amplified and sequenced. Phylogenetic analysis based on the 18S rDNA sequence and the relatives indicated that R6 shared 99% homologies with the members of R. mucilaginosa, suggesting that strain R6 belonged to R. mucilaginosa. Investigation showed that strain R6 possessed the capacity of accumulating exocel-lular alpha-ketoglutaric acid (alpha-KG). Final y, the fermentation conditions of R6 to accumulate alpha-KG was optimized by control ing each single fermenting variable and detected through high performance liquid chromatography (HPLC). Results showed that both VB1 and CaCO3 in fermentation medium were the key factors in-fluencing the cumulant of alpha-KG. The discovery of natural auxotrophic strain R6 not only broadened the microbial resource which can achieve lots of alpha-KG pro-duction through fermentation, but also laid a foundation for further fermentation regu-lation to achieve excessive alpha-KG accumulation.%该研究通过硫胺素( VB1)营养缺陷型负选择法,从中国淄博食用油污染的土壤中获得一株酵母属菌株 R6。该菌株具有累积胞外α-酮戊二酸(α-KG)的能力。生理学和生物化学实验表明该 R6菌株与已测试的 API 20 C AUX酵母鉴别系统中的胶红酵母具有共同特征。此外,R6菌株的18S rDNA 基因已经获得并测序,基于该序列以及同源菌属所得到的系统进化学分析表明菌株 R6与胶红酵母属成员具有99%的同源性。因此,菌株 R6被鉴别为胶红酵母属的一员。随后,本实验通过控制单一发酵变量以及高效液相

  5. Hepatic bile acids and bile acid-related gene expression in pregnant and lactating rats

    Qiong N. Zhu

    2013-08-01

    Full Text Available Background. Significant physiological changes occur during pregnancy and lactation. Intrahepatic cholestasis of pregnancy (ICP is a liver disease closely related to disruption of bile acid homeostasis. The objective of this study was to examine the regulation of bile acid synthesis and transport in normal pregnant and lactating rats. Materials and Methods. Livers from timed pregnant SD rats were collected on gestational days (GD 10, 14 and 19, and postnatal days (PND 1, 7, 14 and 21. Total bile acids were determined by the enzymatic method, total RNA was isolated and subjected to real time RT-PCR analysis. Liver protein was extracted for western-blot analysis. Results. Under physiological conditions hepatic bile acids were not elevated during pregnancy but increased during lactation in rats. Bile acid synthesis rate-limiting enzyme Cyp7a1 was unchanged on gestational days, but increased on PND14 and 21 at mRNA and protein levels. Expression of Cyp8b1, Cyp27a1 and Cyp7b1 was also higher during lactation. The mRNA levels of small heterodimer partner (SHP and protein levels of farnesoid X receptor (FXR were increased during pregnancy and lactation. Bile acid transporters Ntcp, Bsep, Mrp3 and Mrp4 were lower at gestation, but increased during lactation. Hepatic Oatp transporters were decreased during pregnancy and lactation. Conclusion. Hepatic bile acid homeostasis is maintained during normal pregnancy in rats, probably through the FXR-SHP regulation. The expression of bile acid synthesis genes and liver bile acid accumulation were increased during lactation, together with increased expression of bile acid efflux transporter Bsep, Mrp3 and Mrp4.

  6. Biota-Sediment Accumulation Factor Data

    U.S. Environmental Protection Agency — The Biota-Sediment Accumulation Factor contains approximately 20,000 biota-sediment accumulation factors (BSAFs) from 20 locations (mostly Superfund sites) for...

  7. Total lipid and fatty acid accumulation during basidiospore formation in the ectomycorrhizal fungus Pisolithus sp. Acúmulo de lipídeos totais e de ácidos graxos durante a formação de basidiósporos no fungo ectomicorrízico Pisolithus sp.

    André Narvaes da Rocha Campos

    2008-08-01

    Full Text Available The basidiospores of Pisolithus sp. contain large amounts of lipids, indicating provision for future germination in the host rhizosphere. However, the accumulation, composition, and mobilization of lipids during formation and germination of these spores are largely unknown. In this study, lipid storage and fatty acid composition during basidiosporogenesis were analyzed in fresh basidiocarps using bright-field microscopy and gas chromatography. Abundant lipid bodies are found in the hyphae, basidia, and basidiospores of fungal basidiocarps. This evidences a considerable C transport in the basidiocarp to meet the C demand during basidiospore formation. Fatty acid composition analysis revealed the presence of 24 compounds with chains of 9 to 18 C atoms, either saturated or insaturated, with one or two insaturations. The fatty acid composition and content varied according to the developmental stage of the peridioles. In free basidiospores, the predominant compounds were 16:0, 16:1w5c, 18:1w9c, and 18:2w6,9c/18:0ante, at concentrations of 76, 46, 192, and 51 µg g-1 dry matter, respectively. Our results indicate that oleic acid is the major constituent of lipid reserves in Pisolithus sp. basidiospores. Further studies are being conducted to determine the factors that induce lipid mobilization during spore germination.Os basidiósporos de Pisolithus sp. contêm grande quantidade de lipídeos, indicando provisão para futura germinação na rizosfera da planta hospedeira. No entanto, pouco se conhece a respeito do acúmulo, da composição e da mobilização dos lipídeos durante a formação e germinação dos esporos. Neste trabalho, o armazenamento de lipídeos e a análise da composição em ácidos graxos durante a basidiosporogênese foram estudados utilizando-se técnicas de microscopia de luz e cromatografia gasosa. O basidiocarpo fúngico apresentou abundantes corpos lipídicos no interior de suas hifas, basídios e basidiósporos. Esse fato

  8. Characterization of accumulated precipitates during subsurface iron removal

    Research highlights: → Accumulated iron was not found to clog the well or aquifer after 12 years of subsurface iron removal. → 56-100% of accumulated iron hydroxides were found to be crystalline. → Subsurface iron removal favoured certain soil layers, either due to hydraulics or mineralogy. → Other groundwater constituents, such as manganese and arsenic were found to co-accumulate with iron. - Abstract: The principle of subsurface iron removal for drinking water supply is that aerated water is periodically injected into the aquifer through a tube well. On its way into the aquifer, the injected O2-rich water oxidizes adsorbed Fe2+, creating a subsurface oxidation zone. When groundwater abstraction is resumed, the soluble Fe2+ is adsorbed and water with reduced Fe concentrations is abstracted for multiple volumes of the injection water. In this article, Fe accumulation deposits in the aquifer near subsurface treatment wells were identified and characterized to assess the sustainability of subsurface iron removal regarding clogging of the aquifer and the potential co-accumulation of other groundwater constituents, such as As. Chemical extraction of soil samples, with Acid-Oxalate and HNO3, showed that Fe had accumulated at specific depths near subsurface iron removal wells after 12 years of operation. Whether it was due to preferred flow paths or geochemical mineralogy conditions; subsurface iron removal clearly favoured certain soil layers. The total Fe content increased between 11.5 and 390.8 mmol/kg ds in the affected soil layers, and the accumulated Fe was found to be 56-100% crystalline. These results suggest that precipitated amorphous Fe hydroxides have transformed to Fe hydroxides of higher crystallinity. These crystalline, compact Fe hydroxides have not noticeably clogged the investigated well and/or aquifer between 1996 and 2008. The subsurface iron removal wells even need less frequent rehabilitation, as drawdown increases more slowly than in normal

  9. Accumulation of terpenoid phytoalexins in maize roots is associated with drought tolerance.

    Vaughan, Martha M; Christensen, Shawn; Schmelz, Eric A; Huffaker, Alisa; McAuslane, Heather J; Alborn, Hans T; Romero, Maritza; Allen, Leon Hartwell; Teal, Peter E A

    2015-11-01

    Maize (Zea mays) production, which is of global agro-economic importance, is largely limited by herbivore pests, pathogens and environmental conditions, such as drought. Zealexins and kauralexins belong to two recently identified families of acidic terpenoid phytoalexins in maize that mediate defence against both pathogen and insect attacks in aboveground tissues. However, little is known about their function in belowground organs and their potential to counter abiotic stress. In this study, we show that zealexins and kauralexins accumulate in roots in response to both biotic and abiotic stress including, Diabrotica balteata herbivory, Fusarium verticillioides infection, drought and high salinity. We find that the quantity of drought-induced phytoalexins is positively correlated with the root-to-shoot ratio of different maize varieties, and further demonstrate that mutant an2 plants deficient in kauralexin production are more sensitive to drought. The induction of phytoalexins in response to drought is root specific and does not influence phytoalexin levels aboveground; however, the accumulation of phytoalexins in one tissue may influence the induction capacity of other tissues. PMID:25392907

  10. 47 CFR 32.3100 - Accumulated depreciation.

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Accumulated depreciation. 32.3100 Section 32... Accumulated depreciation. (a) This account shall include the accumulated depreciation associated with the... with depreciation amounts concurrently charged to Account 6561, Depreciation...

  11. Acute intestinal injury induced by acetic acid and casein: prevention by intraluminal misoprostol

    Acute injury was established in anesthetized rabbits by intraluminal administration of acetic acid with and without bovine casein, into loops of distal small intestine. Damage was quantified after 45 minutes by the blood-to-lumen movement of 51Cr-labeled ethylenediaminetetraacetic acid (EDTA) and fluorescein isothiocyanate-tagged bovine serum albumin as well as luminal fluid histamine levels. The amount of titratable acetic acid used to lower the pH of the treatment solutions to pH 4.0 was increased by the addition of calcium gluconate. Luminal acetic acid caused a 19-fold increase in 51Cr-EDTA accumulation over saline controls; casein did not modify this effect. In saline controls, loop fluid histamine levels bordered on the limits of detection (1 ng/g) but were elevated 19-fold by acetic acid exposure and markedly increased (118-fold) by the combination of acid and casein. Intraluminal misoprostol (3 or 30 micrograms/mL), administered 30 minutes before acetic acid, significantly attenuated the increase in epithelial permeability (luminal 51Cr-EDTA, fluorescein isothiocyanate-bovine serum albumin accumulation) and histamine release (P less than 0.05). Diphenhydramine, alone or in combination with cimetidine, and indomethacin (5 mg/kg IV) were not protective. It is concluded that exposure of the epithelium to acetic acid promotes the transepithelial movement of casein leading to enhanced mast cell activation and mucosal injury. Damage to the epithelial barrier can be prevented by misoprostol

  12. New strategies for optimal methane production from long chain fatty acids

    Cavaleiro, A. J.; Salvador, A. F.; Silva, Sérgio; Pereira, M.A.; Sousa, D.Z.; Alves, M. M.

    2012-01-01

    High methane production can be expected from biodegradation of long chain fatty acids (LCFA) in anaerobic bioreactors; however, in practice, this process is limited by LCFA accumulation onto the sludge. To optimize methane production from LCFA-rich wastewater, two novel strategies were tested: (i) bioreactor start-up based on the alternation of continuous-feeding phases with batch-degradation phases, and (ii) bioreactor bioaugmentation with the LCFAdegrading bacterium Syntrophomonas zehnderi....

  13. Characterization of accumulated precipitates during subsurface iron removal

    Van Halem, Doris

    2011-01-01

    The principle of subsurface iron removal for drinking water supply is that aerated water is periodically injected into the aquifer through a tube well. On its way into the aquifer, the injected O2-rich water oxidizes adsorbed Fe 2+, creating a subsurface oxidation zone. When groundwater abstraction is resumed, the soluble Fe 2+ is adsorbed and water with reduced Fe concentrations is abstracted for multiple volumes of the injection water. In this article, Fe accumulation deposits in the aquifer near subsurface treatment wells were identified and characterized to assess the sustainability of subsurface iron removal regarding clogging of the aquifer and the potential co-accumulation of other groundwater constituents, such as As. Chemical extraction of soil samples, with Acid-Oxalate and HNO3, showed that Fe had accumulated at specific depths near subsurface iron removal wells after 12 years of operation. Whether it was due to preferred flow paths or geochemical mineralogy conditions; subsurface iron removal clearly favoured certain soil layers. The total Fe content increased between 11.5 and 390.8 mmol/kg ds in the affected soil layers, and the accumulated Fe was found to be 56-100% crystalline. These results suggest that precipitated amorphous Fe hydroxides have transformed to Fe hydroxides of higher crystallinity. These crystalline, compact Fe hydroxides have not noticeably clogged the investigated well and/or aquifer between 1996 and 2008. The subsurface iron removal wells even need less frequent rehabilitation, as drawdown increases more slowly than in normal production wells. Other groundwater constituents, such as Mn, As and Sr were found to co-accumulate with Fe. Acid extraction and ESEM-EDX showed that Ca occurred together with Fe and by X-ray Powder Diffraction it was identified as calcite. © 2010 Elsevier Ltd. All rights reserved.

  14. Markov models for accumulating mutations

    Beerenwinkel, Niko

    2007-01-01

    We introduce and analyze a waiting time model for the accumulation of genetic changes. The continuous time conjunctive Bayesian network is defined by a partially ordered set of mutations and by the rate of fixation of each mutation. The partial order encodes constraints on the order in which mutations can fixate in the population, shedding light on the mutational pathways underlying the evolutionary process. We study a censored version of the model and derive equations for an EM algorithm to perform maximum likelihood estimation of the model parameters. We also show how to select the maximum likelihood poset. The model is applied to genetic data from different cancers and from drug resistant HIV samples, indicating implications for diagnosis and treatment.

  15. Chip integrated fuel cell accumulator

    Frank, M.; Erdler, G.; Frerichs, H.-P.; Müller, C.; Reinecke, H.

    A unique new design of a chip integrated fuel cell accumulator is presented. The system combines an electrolyser and a self-breathing polymer electrolyte membrane (PEM) fuel cell with integrated palladium hydrogen storage on a silicon substrate. Outstanding advantages of this assembly are the fuel cell with integrated hydrogen storage, the possibility of refuelling it by electrolysis and the opportunity of simply refilling the electrolyte by adding water. By applying an electrical current, wiring the palladium hydrogen storage as cathode and the counter-electrode as anode, the electrolyser produces hydrogen at the palladium surface and oxygen at the electrolyser cell anode. The generated hydrogen is absorbed by the palladium electrode and the hydrogen storage is refilled consequently enabling the fuel cell to function.

  16. Chip integrated fuel cell accumulator

    Frank, M.; Mueller, C.; Reinecke, H. [Laboratory for Process Technology, IMTEK-Department of Microsystems Engineering, University of Freiburg, Georges-Koehler-Allee 103, 79110 Freiburg (Germany); Erdler, G.; Frerichs, H.-P. [Micronas GmbH, Hans-Bunte-Strasse 19, Freiburg (Germany)

    2008-07-01

    A unique new design of a chip integrated fuel cell accumulator is presented. The system combines an electrolyser and a self-breathing polymer electrolyte membrane (PEM) fuel cell with integrated palladium hydrogen storage on a silicon substrate. Outstanding advantages of this assembly are the fuel cell with integrated hydrogen storage, the possibility of refuelling it by electrolysis and the opportunity of simply refilling the electrolyte by adding water. By applying an electrical current, wiring the palladium hydrogen storage as cathode and the counter-electrode as anode, the electrolyser produces hydrogen at the palladium surface and oxygen at the electrolyser cell anode. The generated hydrogen is absorbed by the palladium electrode and the hydrogen storage is refilled consequently enabling the fuel cell to function. (author)

  17. L-lysine escinat, thiotriazolin, gordox and mydocalm influence on oxygen tension in the intestinal wall and acid-base balance and limited proteolysis in intestinal venous blood in terms of intraabdominal hypertension modeling

    Sapegin V.I.

    2014-11-01

    Full Text Available In acute experiments on rabbits there were studied changes in oxygen tension in the intestinal wall tissues, acid-base balance and limited proteolysis and its inhibitors in intestinal venous blood, protective action of L-lysine escinat (0,15 mg/kg / single dose, thiotriazolin (25 mg/kg / single dose, aprotinin (gordox (10,000 units/kg / single dose in sequential modeling of standard levels increasing of intra-abdominal hypertension (IAH — 50, 100, 150, 200, 250, 300, 350 m H2O, and also of tolperison (mydocalm (5 mg/kg / single dose on modeling of stable 3-hour IAH 200 m H2O. The IAH modeling was performed by means of stand of our construction. Under the influence of IAH the compensated metabolic acidosis in intestinal venous blood with a compensative hyperpnoe develops, decline of oxygen tension in tissues and activating of a limited proteolysis as well as decline of its inhibitors activity in intestinal venous blood occur. By the degree of metabolic acidosis prevention investigational preparations were distributed as follows gordox > thiotriazolin = L-lysine escinat = mydocalm, and by prevention of decline of oxygen tension in tissues — thiotriazolin > L-lysine escinat > mydocalm > gordox, it is is connected with different rate of methabolic products excretion into the blood, due to the influence on blood circulation and transcapilary exchange. By the degree of prevention of proteolytic activity and inhibitory potential changes, investigational preparations were distributed as follows: gordox > mydocalm > thiotriazolin > L-lysine escinat, this is connected with inhibition of proteolysis in gordox, and in other ones – with reduction of ischemic damage of tissues. Owing to different mechanism of action thiotriazolin, L-lysine escinat and mydocalm may be simultaneously recommended for a conservative treatment of patients with intraabdominal hypertension syndrome.

  18. Stillage reflux in food waste ethanol fermentation and its by-product accumulation.

    Ma, Hongzhi; Yang, Jian; Jia, Yan; Wang, Qunhui; Tashiro, Yukihiro; Sonomoto, Kenji

    2016-06-01

    Raw materials and pollution control are key issues for the ethanol fermentation industry. To address these concerns, food waste was selected as fermentation substrate, and stillage reflux was carried out in this study. Reflux was used seven times during fermentation. Corresponding ethanol and reducing sugar were detected. Accumulation of by-products, such as organic acid, sodium chloride, and glycerol, was investigated. Lactic acid was observed to accumulate up to 120g/L, and sodium chloride reached 0.14mol/L. Other by-products did not accumulate. The first five cycles of reflux increased ethanol concentration, which prolonged fermentation time. Further increases in reflux time negatively influenced ethanol fermentation. Single-factor analysis with lactic acid and sodium chloride demonstrated that both factors affected ethanol fermentation, but lactic acid induced more effects. PMID:26974357

  19. Acúmulo de ácido oxálico e cristais de cálcio em ectomicorrizas de eucalipto.: I- produção de ácido oxálico e concentração de nutrientes em raízes laterais finas colonizadas por fungos ectomicorrízicos Accumulation of oxalic acid and calcium crystals in eucalypt ectomycorrhizas.: I- oxalic acid production and nutrient concentration in fine lateral roots colonized with ectomicorrhizal fungi

    Jhon Alexander Zambrano Gonzalez

    2009-06-01

    Full Text Available O eucalipto apresenta ótimo crescimento em solo com baixa fertilidade, mas pouco se sabe sobre a participação das ectomicorrizas e de ácidos orgânicos na aquisição e no acúmulo de nutrientes pela planta em campo. A produção de ácido oxálico e sua relação com as concentrações de P, Ca, Mg e K foram avaliadas em ectomicorrizas e raízes laterais finas de híbrido de Eucalyptus grandis x Eucalyptus urophylla, de 2,5 anos de idade, na região de Viçosa, MG. A área de estudo apresenta topografia típica em meia laranja, de vertente côncavo-convexa. Foram também avaliadas as concentrações desse composto no solo rizosférico, não rizosférico e ectomicorrizosférico. As maiores percentagens de colonização micorrízica foram observadas na área de encosta, onde havia limitada disponibilidade de nutrientes e alta saturação de Al. As concentrações de ácido oxálico + oxalato corresponderam, em mg kg-1: folhas, 324,6; ectomicorrizas, 208,3; raízes laterais finas não colonizadas, 183,1. Já no solo, as concentrações foram maiores no solo ectomicorrizosférico, com 183,7 mg kg-1, seguido pelo solo rizosférico, com 134,3 mg kg-1, e pelo solo não rizosférico, com 76,0 mg kg-1. As maiores concentrações de ácido oxálico e P (p Eucalypt is highly efficient at growing in nutrient-poor soils, but little is known about the role of ectomycorrhizas and organic acids in nutrient uptake and storage under field conditions. Oxalic acid production and its relationships with Ca, P, K, and Mg concentrations were evaluated in the ectomycorrhizas and fine lateral roots of a 2.5 year-old Eucalyptus grandis x Eucalyptus urophylla hybrid grown in a mountainous area at Viçosa, MG, Brazil. Oxalic acid concentrations were also evaluated in rhizospheric, non-rhizospheric, and ectomycorhizospheric soil. Mycorrhizal colonization was highest in a slope area with limited nutrient availability and high Al saturation. The oxalic acid concentration

  20. Guidelines for Waste Accumulation Areas (WAAs)

    The purpose of this document is to set conditions for establishing and maintaining areas for the accumulation of hazardous waste at LBL. Areas designed for accumulation of these wastes in quantities greater than 100 kg (220 lb) per month of solid waste or 55 gallons per month of liquid waste are called Waste Accumulation Areas (WAAs). Areas designed for accumulation of wastes in smaller amounts are called Satellite Accumulation Areas (SAAs). This document provides guidelines for employee and organizational responsibilities for WAAs; constructing a WAA; storing waste in a WAA; operating and maintaining a WAA, and responding to spills in a WAA. 4 figs

  1. Guidelines for Waste Accumulation Areas (WAAs)

    1991-07-01

    The purpose of this document is to set conditions for establishing and maintaining areas for the accumulation of hazardous waste at LBL. Areas designed for accumulation of these wastes in quantities greater than 100 kg (220 lb) per month of solid waste or 55 gallons per month of liquid waste are called Waste Accumulation Areas (WAAs). Areas designed for accumulation of wastes in smaller amounts are called Satellite Accumulation Areas (SAAs). This document provides guidelines for employee and organizational responsibilities for WAAs; constructing a WAA; storing waste in a WAA; operating and maintaining a WAA, and responding to spills in a WAA. 4 figs.

  2. Radionuclide accumulation peculiarities demonstrated by vegetable varieties

    This study focused on ecological and genetic aspects of radionuclide accumulation demonstrated by a number of vegetable varieties. The researches resulted in determining the cabbage varieties which were characterised by the minimal level of radionuclide accumulation. It was shown that the above varieties manifested the relation between radionuclide accumulation and morphobiological characteristics such as vegetation period duration and yield criteria. The study specified the genotypes with high ecological stability as regards to radionuclide accumulation: 'Beloruskaya 85' cabbage and 'Dokhodny' tomato showed the best response to Cs 137, while 'Beloruskaya 85', 'Rusinovka', 'Amager 611' cabbage varieties and 'Sprint' tomato showed the minimal level of Sr 90 accumulation. (authors)

  3. Morphological Studies of Synechocystis sp. UNIWG under Polyhydroxyalkanoate Accumulating Conditions

    Yew, S. P.

    2005-01-01

    Full Text Available Some cyanobacteria are capable of producing polyhydroxyalkanoate (PHA, among which is the unicellular Synechocystis sp. Here, we report the identification and preliminary characterization of a newly isolated strain of Synechocystis sp. UNIWG that is capable of accumulating unusually high number of PHA granules. This cyanobacterium was isolated from oil-contaminated brackish water sample from Wadi Gaza, Palestine. Surprisingly, Nile Blue A staining of PHA-accumulating cells failed to reveal the accumulated PHA granules. Ultrastructural analysis of Synechocystis sp. UNIWG cells grown under nitrogen limiting conditions revealed the presence of up to 17 electron-transparent granules in the cell cytoplasm. Gas chromatography analysis further revealed that these cells contain up to 14 wt% poly(3-hydroxybutyrate of the cell dry weight. Ultrastructural analysis also revealed that Synechocystis sp. UNIWG cells from the growth phase were covered with a dense layer of pilus like structures. However, these pilus-like structures were not observed in cells from the PHA-accumulation phase. The possible roles of these pilus-like structures and PHA accumulation for the survival of this cyanobacterium is discussed here.

  4. Identification and application of keto acids transporters in Yarrowia lipolytica

    Hongwei Guo; Peiran Liu; Catherine Madzak; Guocheng Du; Jingwen Zhou; Jian Chen

    2015-01-01

    Production of organic acids by microorganisms is of great importance for obtaining building-block chemicals from sustainable biomass. Extracellular accumulation of organic acids involved a series of transporters, which play important roles in the accumulation of specific organic acid while lack of systematic demonstration in eukaryotic microorganisms. To circumvent accumulation of by-product, efforts have being orchestrated to carboxylate transport mechanism for potential clue in Yarrowia lip...

  5. Multiple shoot regeneration and alkaloid cerpegin accumulation in callus culture of Ceropegia juncea Roxb.

    Nikam, T. D.; Savant, R. S.

    2009-01-01

    This is the first report of in vitro propagation and alkaloid accumulation in callus cultures of Ceropegia juncea Roxb. a source of “Soma” drug in Ayurvedic medicine. Multiple shoots and callus induction was optimized by studying the influence of auxins [IAA (Indole-3-acetic acid), NAA (2-Naphthalene acetic acid) and 2,4-D (2,4-Dichlorophenoxyacetic acid.)] and cytokinins [BA (6-benzyladenine) and Kin (Kinetin)] alone and in combinations. The best response for multiple shoot induction was obt...

  6. Cystic fibrosis bronchial epithelial cells are lipointoxicated by membrane palmitate accumulation.

    Laurie-Anne Payet

    Full Text Available The F508del-CFTR mutation, responsible for Cystic Fibrosis (CF, leads to the retention of the protein in the endoplasmic reticulum (ER. The mistrafficking of this mutant form can be corrected by pharmacological chaperones, but these molecules showed limitations in clinical trials. We therefore hypothesized that important factors in CF patients may have not been considered in the in vitro assays. CF has also been associated with an altered lipid homeostasis, i. e. a decrease in polyunsaturated fatty acid levels in plasma and tissues. However, the precise fatty acyl content of membrane phospholipids from human CF bronchial epithelial cells had not been studied to date. Since the saturation level of phospholipids can modulate crucial membrane properties, with potential impacts on membrane protein folding/trafficking, we analyzed this parameter for freshly isolated bronchial epithelial cells from CF patients. Interestingly, we could show that Palmitate, a saturated fatty acid, accumulates within Phosphatidylcholine (PC in CF freshly isolated cells, in a process that could result from hypoxia. The observed PC pattern can be recapitulated in the CFBE41o(- cell line by incubation with 100 µM Palmitate. At this concentration, Palmitate induces an ER stress, impacts calcium homeostasis and leads to a decrease in the activity of the corrected F508del-CFTR. Overall, these data suggest that bronchial epithelial cells are lipointoxicated by hypoxia-related Palmitate accumulation in CF patients. We propose that this phenomenon could be an important bottleneck for F508del-CFTR trafficking correction by pharmacological agents in clinical trials.

  7. Acúmulo de ácido oxálico e cristais de cálcio em ectomicorrizas de eucalipto.: II- formação de cristais de oxalato de cálcio induzida por fungos ectomicorrízicos em raízes laterais finas Accumulation of oxalic acid and calcium crystals in ectomycorrhizas of eucalypt.: II- calcium oxalate crystal formation induced by ectomicorrhizal fungi in fine lateral roots

    Jhon Alexander Zambrano Gonzalez

    2009-06-01

    Full Text Available O eucalipto é eficiente na aquisição de Ca do solo, mas pouco se sabe sobre a participação das ectomicorrizas e dos ácidos orgânicos nesse processo em campo. O acúmulo de cristais de Ca (CaOx foi avaliado em, aproximadamente, 2.100 raízes laterais finas e ectomicorrizas do híbrido de Eucalyptus grandis x Eucalyptus urophylla, cultivado por 2,5 anos em área com topografia típica em meia laranja, com vertente côncavo-convexa, na região de Viçosa, MG. Técnicas de microscopia óptica e microscopia eletrônica de varredura foram usadas para a visualização dos CaOx. Em 73,7 % das raízes, ocorreu abundante acúmulo de drusas e grânulos de CaOx nas células do córtex. A presença conspícua de CaOx foi observada em 56,2 % das ectomicorrizas e em 17,5 % das raízes laterais finas não colonizadas, evidenciando o papel das micorrizas no acúmulo de Ca em eucalipto. A forma predominante dos CaOx foram as drusas nas ectomicorrizas e os grânulos cristalinos nas raízes. Os dez morfotipos de ectomicorrizas observados na área diferiram quanto à presença e à morfologia dos CaOx, o que pode representar distintas capacidades dos fungos ectomicorrízicos em fornecer Ca para a planta hospedeira. A análise da superfície do manto das ectomicorrizas por microscopia eletrônica de varredura não evidenciou a presença de CaOx nessa estrutura, confirmando que, nas condições avaliadas, o acúmulo de cristais limita-se ao córtex radicular. Este é o primeiro relato da ocorrência de CaOx em ectomicorrizas de eucalipto no Brasil, com dados que comprovam que há mecanismos de armazenamento de Ca nas ectomicorrizas em áreas com baixa disponibilidade do elemento.Eucalypt is efficient at taking up Ca from the soil, however little is known about the contribution of ectomycorrhizas and organic acids to this process under field conditions. The accumulation of calcium oxalate crystals (CaOx was evaluated in, approximately, 2,100 fine lateral roots

  8. Effect of nitrogen and/or oxygen concentration on poly(3-hydroxybutyrate) accumulation by Halomonas boliviensis.

    García-Torreiro, María; Lu-Chau, Thelmo A; Lema, Juan M

    2016-09-01

    The behaviour of Halomonas boliviensis during growth in fed-batch culture under different kind of nutrient restrictions was examined. The metabolic switch between growth and accumulation phase is determined by the limitation in one or more essential nutrient for bacterial growth. The aim of this study was to test the effect of applying limitations of a essential nutrient, such as nitrogen, and the influence of different O2 concentrations on poly(3-hydroxybutyrate) (PHB) production during the accumulation phase. Single limitations of nitrogen and oxygen provoke PHB accumulations of 45 and 37 % (g g(-1)), respectively, while N limitation with low O2 supply causes the highest PHB accumulation of 73 %. The characterization of the PHB production with the strain H. boliviensis would allow a better optimization of the process and enrich the knowledge about the PHB production from strains different than Cupriavidus necator. PMID:27126501

  9. Different responses of low grain-Cd-accumulating and high grain-Cd-accumulating rice cultivars to Cd stress.

    Wang, Feijuan; Wang, Min; Liu, Zhouping; Shi, Yan; Han, Tiqian; Ye, Yaoyao; Gong, Ning; Sun, Junwei; Zhu, Cheng

    2015-11-01

    Cadmium (Cd) is a major heavy metal pollutant which is highly toxic to plants and animals. The accumulation of Cd in rice grains is a major agricultural problem in regions with Cd pollution. A hydroponics experiment using low grain-Cd-accumulating rice (xiushui 11) and high grain-Cd-accumulating rice (xiushui 110) was carried out to characterize the different responses of rice cultivars to Cd stress. We found that xiushui 11 was more tolerant to Cd than xiushui 110, and xiushui 11 suffered less oxidative damage. Cell walls played an important role in limiting the amount of Cd that entered the protoplast, especially in xiushui 11. Cd stored in organelles as soluble fractions, leading to greater physiological stress of Cd detoxification. We found that Cd can disturb the ion homeostasis in rice roots because Cd(2+) and Ca(2+) may have a similar uptake route. Xiushui 11 had a faster root-to-shoot transport of Cd, and the expression level of OsPCR1 gene which was predicted related with Cd accumulation in rice was consist with the Cd transport of root-to-shoot in rice and maintain the greater Cd tolerance of xiushui 11. These results suggest there are different Cd detoxification and accumulation mechanisms in rice cultivars. PMID:26318143

  10. Nitrogen-deprivation elevates lipid levels in Symbiodinium spp. by lipid droplet accumulation: morphological and compositional analyses.

    Pei-Luen Jiang

    Full Text Available Stable cnidarian-dinoflagellate (genus Symbiodinium endosymbioses depend on the regulation of nutrient transport between Symbiodinium populations and their hosts. It has been previously shown that the host cytosol is a nitrogen-deficient environment for the intracellular Symbiodinium and may act to limit growth rates of symbionts during the symbiotic association. This study aimed to investigate the cell proliferation, as well as ultrastructural and lipid compositional changes, in free-living Symbiodinium spp. (clade B upon nitrogen (N-deprivation. The cell proliferation of the N-deprived cells decreased significantly. Furthermore, staining with a fluorescent probe, boron dipyrromethane 493/503 (BODIPY 493/503, indicated that lipid contents progressively accumulated in the N-deprived cells. Lipid analyses further showed that both triacylglycerol (TAG and cholesterol ester (CE were drastically enriched, with polyunsaturated fatty acids (PUFA; i.e., docosahexaenoic acid, heneicosapentaenoic acid, and oleic acid became more abundant. Ultrastructural examinations showed that the increase in concentration of these lipid species was due to the accumulation of lipid droplets (LDs, a cellular feature that have previously shown to be pivotal in the maintenance of intact endosymbioses. Integrity of these stable LDs was maintained via electronegative repulsion and steric hindrance possibly provided by their surface proteins. Proteomic analyses of these LDs identified proteins putatively involved in lipid metabolism, signaling, stress response and energy metabolism. These results suggest that LDs production may be an adaptive response that enables Symbiodinium to maintain sufficient cellular energy stores for survival under the N-deprived conditions in the host cytoplasm.

  11. Accumulation rates of airborne heavy metals in wetlands

    Souch, C.J.; Filippelli, G.M.; Dollar, N.; Perkins, S.; Mastalerz, Maria

    2002-01-01

    Accumulation rates of heavy metals (Cd, Cr, Cu, Mn, Pb, and Zn) retained in wetland sediments in northwest Indiana-downwind of the Chicago-Gary-Hammond industrial area-are quantified to assess anthropogenic influences on atmospheric fluxes. Metal concentrations for 22 sediment cores are determined by ICP-AES after ashing and strong acid extraction. Relations between organic content and metal concentrations at depth are used to separate natural and anthropogenic sources. Accumulation rates over the lifetime of the wetlands (???4500 years) have averaged 0.2 (Cd), 1.4 (Cu), 1.7 (Cr), 13.4 (Mn), 4.8 (Pb), and 18.7 (Zn) mg m-2 y-1. Rates for the last 100 years have increased on average by factors of 6 (Cd), 8 (Cu), 10 (Mn), 15 (Pb), and 30 (Zn), remaining effectively constant for Cr. Where the wetlands have been drained, metals have been lost from the sediments, owing to changes in organic content and local hydrochemistry (exposure to acidic rainfall). Sediment-based accumulation rates at the undrained sites are higher, though generally consistent, with measured and modeled atmospheric fluxes documented by short-term studies conducted over the last three decades. The fraction of the total metals in the wetlands estimated to be of anthropogenic origin ranges from approximately 3% for Cr, up to approximately 35% for Pb, and 70% for Zn. This historic legacy of contamination must be considered in land management decisions, particularly when wetlands are drained.

  12. Accumulation of disparity in physical activity in old age

    Eronen, Johanna; von Bonsdorff, Mikaela; Rantakokko, Merja; Rantanen, Taina

    2012-01-01

    Background and aims: The level of physical activity often declines in old age, although many older people would like to be more active than what they are capable of. This leads to unmet physical activity need, the feeling that one’s level of physical activity is inadequate, which is a manifestation of disparity in physical activity in old age. The accumulation of risk factors, including mobility limitations, low socioeconomic status (SES) and lack of social support may increase disparity in p...

  13. Accumulation of glycosaminoglycans in radiation-induced muscular fibrosis

    The content and biosynthesis of glycosaminoglycans (GAGs) were studied in pig thigh muscle after acute local γ-irradiation. Seven months following irradiation, the muscular tissue next to the irradiation cone was replaced by severe mutilating fibrosis delimited by an intermediary perifibrotic zone. Results showed a parallel increase of collagen and GAG content in perifibrotic and fibrotic tissues. Sulphated GAGs, heparan sulphate and dermatan sulphate were preferentially accumulated in fibrotic tissue, while the hyaluronic acid content increased only slightly. Synthesis of sulphated GAGs was more elevated in fibrotic tissue than in perifibrotic zone as compared with normal muscle. Seven months after irradiation well-developed fibrotic tissue continued to synthesize and to accumulate extracellular matrix macromolecules. (Author)

  14. Sucrose accumulation in mature sweet melon fruits. [Cucumis melo

    Schaffer, A.A.; Aloni, B.

    1987-04-01

    Mesocarp tissue from sucrose-accumulating sweet melon (Cucumis melo cv. Galia) showed sucrose synthase activity (ca 1 nkat/gfw) while soluble acid invertase and sucrose phosphate synthase activities were not observed. Sucrose uptake into mesocarp discs was linear with sucrose concentration (1-500 mM) and unaffected by PCMBS and CCCP. Sucrose compartmentation into the vacuole also increased linearly with sucrose concentration as indicated by compartmental efflux kinetics. Mesocarp discs incubated in /sup 14/C-fructose + UDP-glu synthesized /sup 14/C-sucrose and efflux kinetics indicated that the /sup 14/C-sucrose was compartmentalized. These data support the hypothesis that two mechanisms are involved in sucrose accumulation in sweet melon: (1) compartmentation of intact sucrose and (2) synthesis of sucrose via sucrose synthase and subsequent compartmentation in the vacuole.

  15. ACCUMULATION AND CONSUMPTION IN MICROECONOMIC SYSTEM

    Serghey A. Amelkin

    2004-12-01

    Full Text Available Two main processes are common for an economic system. They are consumption and accumulation. The first one is described by utility function, either cardinal or ordinal one. The mathematical model for accumulation process can be constructed using wealth function introduced within the frame of irreversible microeconomics. Characteristics of utility and wealth functions are compared and a problem of extreme performance of resources exchange process is solved for a case when both the consumption and accumulation exist.

  16. Natural Resource Abundance and Human Capital Accumulation

    Jean-Philippe C. Stijns

    2001-01-01

    This study examines indicators of human capital accumulation together with data for natural resource abundance and rents in a panel of 102 countries running from 1970 to 1999. Mineral wealth makes a positive and marked difference on human capital accumulation. Matching on observables reveals that cross-country results are not driven by a third factor such as overall economic development. Political stability does seem to affect both human capital accumulation and subsoil wealth, but not enough...

  17. Metabolomic analysis reveals mechanism of antioxidant butylated hydroxyanisole on lipid accumulation in Crypthecodinium cohnii.

    Sui, Xiao; Niu, Xiangfeng; Shi, Mengliang; Pei, Guangsheng; Li, Jinghan; Chen, Lei; Wang, Jiangxin; Zhang, Weiwen

    2014-12-24

    The heterotrophic dinoflagellate alga Crypthecodinium cohnii is known to accumulate lipids with a high fraction of docosahexaenoic acid (DHA). In this study, we first evaluated two antioxidant compounds, butylated hydroxyanisole (BHA) and propyl gallate (PG), for their effects on lipid accumulation in C. cohnii. The results showed that antioxidant BHA could increase lipid accumulation in C. cohnii by 8.80% at a final concentration of 30 μM, while PG had no obvious effect on lipid accumulation at the tested concentrations. To decipher the molecular mechanism responsible for the increased lipid accumulation by BHA, we employed an integrated GC-MS and LC-MS metabolomic approach to determine the time-series metabolic profiles with or without BHA, and then subjected the metabolomic data to a principal component analysis (PCA) and a weighted gene coexpression network analysis (WGCNA) network analyses to identify the key metabolic modules and metabolites possibly relevant to the increased lipid accumulation. LC-MS analysis showed that several metabolites, including NADPH, could be important for the stimulation role of BHA on lipid accumulation. Meanwhile GC-MS and network analyses allowed identification of eight metabolic modules and nine hub metabolites possibly relevant to the stimulation role of BHA in C. cohnii. The study provided a metabolomics view of the BHA mode of action on lipid accumulation in C. cohnii, and the information could be valuable for a better understanding of antioxidant effects on lipid accumulation in other microalgae as well. PMID:25436856

  18. Inhibitor degradation and lipid accumulation potentials of oleaginous yeast Trichosporon cutaneum using lignocellulose feedstock.

    Wang, Juan; Gao, Qiuqiang; Zhang, Huizhan; Bao, Jie

    2016-10-01

    Oleaginous yeast Trichosporon cutaneum is robust to high levels of lignocellulose derived inhibitor compounds with considerable lipid accumulation capacity. The potential of lipid accumulation of T. cutaneum ACCC 20271 was investigated using corn stover hydrolysates with varying sugar and inhibitor concentrations. Biodiesel was synthesized using the extracted lipid and the product satisfied the ASTM standards. Among the typical inhibitors, T. cutaneum ACCC 20271 is relatively sensitive to furfural and 4-hydroxybenzaldehyde, but strongly tolerant to high titers of formic acid, acetic acid, levulinic acid, HMF, vanillin, and syringaldehyde. It is capable of complete degradation of formic acid, acetic acid, vanillin and 4-hydroxybenzaldehyde. Finally, the inhibitor degradation pathways of T. cutaneum ACCC 20271 were constructed based on the newly sequenced whole genome information and the experimental results. The study provided the first insight to the inhibitor degradation of T. cutaneum and demonstrated the potentials of lipid production from lignocellulose. PMID:27441826

  19. Factors influencing the accumulation of tetraphenylphosphonium cation in HeLa cells.

    Hiller, R.; Schaefer, A; Zibirre, R; Kaback, H R; Koch, G

    1984-01-01

    Exposure of HeLa cells to tetraphenylphosphonium cation (TPP+) results in a rapid accumulation intracellularly, and a steady-state level is reached within 10 min. Accumulation of [3H]TPP+ in HeLa cells is reduced under the following conditions: (i) after preincubation of cells in buffered saline or in medium containing two- to fourfold higher concentrations of amino acids, (ii) exposure to the alkylating agent L-1-tosylamido-2-phenyl-ethylchloromethyl ketone, (iii) ouabain-mediated inhibition...

  20. A new model of Holocene peatland net primary production, decomposition, water balance, and peat accumulation

    S. Frolking; N. T. Roulet; E. Tuittila; J. L. Bubier; Quillet, A.; J. Talbot; Richard, P.J.H.

    2010-01-01

    Peatland carbon and water cycling are tightly coupled, so dynamic modeling of peat accumulation over decades to millennia should account for carbon-water feedbacks. We present initial results from a new simulation model of long-term peat accumulation, evaluated at a well-studied temperate bog in Ontario, Canada. The Holocene Peat Model (HPM) determines vegetation community composition dynamics and annual net primary productivity based on peat depth (as a proxy for nutrients and acidity) and w...

  1. (Limiting the greenhouse effect)

    Rayner, S.

    1991-01-07

    Traveler attended the Dahlem Research Conference organized by the Freien Universitat, Berlin. The subject of the conference was Limiting the Greenhouse Effect: Options for Controlling Atmospheric CO{sub 2} Accumulation. Like all Dahlem workshops, this was a meeting of scientific experts, although the disciplines represented were broader than usual, ranging across anthropology, economics, international relations, forestry, engineering, and atmospheric chemistry. Participation by scientists from developing countries was limited. The conference was divided into four multidisciplinary working groups. Traveler acted as moderator for Group 3 which examined the question What knowledge is required to tackle the principal social and institutional barriers to reducing CO{sub 2} emissions'' The working rapporteur was Jesse Ausubel of Rockefeller University. Other working groups examined the economic costs, benefits, and technical feasibility of options to reduce emissions per unit of energy service; the options for reducing energy use per unit of GNP; and the significant of linkage between strategies to reduce CO{sub 2} emissions and other goals. Draft reports of the working groups are appended. Overall, the conference identified a number of important research needs in all four areas. It may prove particularly important in bringing the social and institutional research needs relevant to climate change closer to the forefront of the scientific and policy communities than hitherto.

  2. Accumulation, transformation and breakdown of DSP toxins from the toxic dinoflagellate Dinophysis acuta in blue mussels, Mytilus edulis

    Nielsen, Lasse Tor; Hansen, Per Juel; Krock, Bernd;

    2016-01-01

    Okadaic acid (OA), dinophysistoxins (DTX) and pectenotoxins (PTX) produced by the dinoflagellates Dinophysis spp. can accumulate in shellfish and cause diarrhetic shellfish poisoning upon human consumption. Shellfish toxicity is a result of algal abundance and toxicity as well as accumulation and...

  3. Accumulation and breakdown of DSP toxins from the toxic dinoflagellate Dinophysis acuta in blue mussels, Mytilus edulis

    Nielsen, Lasse Tor; Krock, Bernd; Hansen, Per Juel;

    2016-01-01

    Okadaic acid (OA), dinophysistoxins (DTX) and pectenotoxins (PTX) produced by the dinoflagellates Dinophysis spp. can accumulate in shellfish and cause diarrhetic shellfish poisoning upon human consumption. Shellfish toxicity is a result of algal abundance and toxicity as well as accumulation and...

  4. Effects of proteome rebalancing and sulfur nutrition on the accumulation of methionine rich d-zein in transgenic soybeans

    Expression of heterologous methionine-rich proteins to increase the overall sulfur amino acid content of soybean seeds has been only marginally successful, presumably due to low accumulation of transgenes in soybeans. Proteome rebalancing of seed proteins has been shown to promote the accumulation o...

  5. Characters related to higher starch accumulation in cassava storage roots.

    Li, You-Zhi; Zhao, Jian-Yu; Wu, San-Min; Fan, Xian-Wei; Luo, Xing-Lu; Chen, Bao-Shan

    2016-01-01

    Cassava (Manihot esculenta) is valued mainly for high content starch in its roots. Our understanding of mechanisms promoting high starch accumulation in the roots is, however, still very limited. Two field-grown cassava cultivars, Huanan 124(H124) with low root starch and Fuxuan 01(F01) with high root starch, were characterised comparatively at four main growth stages. Changes in key sugars in the leaves, stems and roots seemed not to be strongly associated with the final amount of starch accumulated in the roots. However, when compared with H124, F01 exhibited a more compact arrangement of xylem vascular bundles in the leaf axils, much less callose around the phloem sieve plates in the stems, higher starch synthesis-related enzymatic activity but lower amylase activity in the roots, more significantly up-regulated expression of related genes, and a much higher stem flow rate (SFR). In conclusion, higher starch accumulation in the roots results from the concurrent effects of powerful stem transport capacity highlighted by higher SFR, high starch synthesis but low starch degradation in the roots, and high expression of sugar transporter genes in the stems. A model of high starch accumulation in cassava roots was therefore proposed and discussed. PMID:26892156

  6. Phenylpropanoids accumulation in eggplant fruit: characterization of biosynthetic genes and regulation by a MYB transcription factor

    Teresa eDocimo

    2016-01-01

    Full Text Available Phenylpropanoids are major secondary metabolites in eggplant (Solanum melongena fruits. Chlorogenic acid (CGA accounts for 70 to 90% of total phenolics in flesh tissues, while anthocyanins are mainly present in the fruit skin. As a contribution to the understanding of the peculiar accumulation of these health-promoting metabolites in eggplant, we report on metabolite abundance, regulation of CGA and anthocyanin biosynthesis, and characterization of candidate CGA biosynthetic genes in S. melongena.Higher contents of CGA, Delphinidin 3-rutinoside and rutin were found in eggplant fruits compared to other tissues, associated to an elevated transcript abundance of structural genes such as PAL, HQT, DFR and ANS, suggesting that active in situ biosynthesis contributes to anthocyanin and CGA accumulation in fruit tissues. Putative orthologs of the two CGA biosynthetic genes PAL and HQT, as well as a variant of a MYB1 transcription factor showing identity with group 6 MYBs, were isolated from an Occidental S. melongena traditional variety and demonstrated to differ from published sequences from Asiatic varieties.In silico analysis of the isolated SmPAL1, SmHQT1, SmANS, and SmMyb1 promoters revealed the presence of several Myb regulatory elements for the biosynthetic genes and unique elements for the TF, suggesting its involvement in other physiological roles beside phenylpropanoid biosynthesis regulation.Transient overexpression in Nicotiana benthamiana leaves of SmMyb1 and of a C-terminal SmMyb1 truncated form (SmMyb1Δ9 resulted in anthocyanin accumulation only of SmMyb1 agro-infiltrated leaves. A yeast two-hybrid assay confirmed the interaction of both SmMyb1 and SmMyb1Δ9 with an anthocyanin-related potato bHLH1 TF. Interestingly, a doubled amount of CGA was detected in both SmMyb1 and SmMyb1Δ9 agro-infiltrated leaves, thus suggesting that the N-terminal region of SmMyb1 is sufficient to activate its synthesis. These data suggest that a deletion of

  7. Effect of metal accumulation on optical properties of mosses

    Complete text of publication follows. Photoluminescence (PL) spectroscopy is known to be a powerful tool to detect plant stress and is applied to investigate the effect of metal stress on mosses. Scopelophila cataractae is reported to be a Cu-accumulating moss. Nevertheless, the mechanism of Cu accumulation remains unclear. This is the same for S. ligulata, which is known to be a Fe-accumulating moss. The color of S. cataractae is deep green, deeper than those of other common mosses. Hence, its color must reflect the structure and photoreaction related to Cu accumulated. However, the photoabsorption and PL have not been studied for S. cataractae, as well as for S. ligulata. Even for mosses spectral data are limited. In this study, to understand the effect of metal accumulation on optical properties of S. cataractae and S. ligulata, PL and absorption spectra of these two and other common mosses were measured. We found that the PL intensity of chlorophyll for S. cataractae increases remarkably after moistening whereas for the other mosses the increase is very low; this remarkable increase in PL intensity is suggested to be characteristic of S. cataractae. Correspondingly, it is assumed that there is a difference between chlorophyll in S. cataractae and in the other mosses. To clarify this point, absorption spectra of chlorophyll extracted from the mosses were measured and compared. The absorption spectrum of chlorophyll extracted from S. cataractae agreed with those from other mosses, revealing that S. cataractae has chlorophyll common to those of other mosses. On the other hand, the chlorophyll concentration in S. cataractae was higher than those in other mosses. This may be due to the effect of Cu accumulated in S. cataractae. On the contrary, we found that the absorption spectrum of chlorophyll extracted from S. ligulata differs from those of the other mosses. This indicates that the composition of pigments including chlorophyll, the structures of these pigments

  8. On accumulation time of the Jupiter

    It is suggested that accumulation time of Mars is strongly influenced by the presence of proto-Jupiter. It is shown that accumulation time of the Mars constrains the growth time scale for Jupiter. This constraint has been roughly estimated to be ∼ 1.7x107 y nearly in agreement with the lifetime of T Tauri phase of the Sun

  9. Accumulation of zirconium by microalgae and cyanobacteria

    The accumulation of zirconium (Zr) as [Zr4-(OH)8(H2O)16]8+ by cyanobacteria and microalgae has been characterized. In all the cyanobacterial and microalgal species examined, accumulation consisted of a single rapid energy-independent phase (''biosorp-tion'') and no energy-dependent accumulation was observed. Biosorption of Zr was concentration-dependent, followed a Freundlich adsorption isotherm, and was dependent on pH, showing decreased accumulation with decreased pH. Prior treatment with Na+, K+, Cs+, Ca2+, Mg2+ and Sr2+ (added as chlorides) also decreased Zr accumulation by cyanobacteria and microalgae, probably a result of competition between Zr ions and othecations, including H+, for available binding sites on the cell walls. Zr desorption from micoalgae and cyanobacteria was increased by increasing external cation concentrations or by decreasing the pH of the desorption agent. (orig.)

  10. Drivers of Holocene peatland carbon accumulation across a climate gradient in northeastern North America

    Charman, Dan J.; Amesbury, Matthew J.; Hinchliffe, William; Hughes, Paul D. M.; Mallon, Gunnar; Blake, William H.; Daley, Tim J.; Gallego-Sala, Angela V.; Mauquoy, Dmitri

    2015-08-01

    or fire, but early successional stages of peatland growth had faster rates of C accumulation even though temperatures were probably lower at the time. We conclude that climate is the most important driver of peatland accumulation rates over millennial timescales, but that successional vegetation change is a significant additional influence. Whilst the majority of northern peatlands are likely to increase C accumulation rates under future warmer climates, those at the southern limit of distribution may show reduced rates. However, early succession peatlands that develop under future warming at the northern limits of peatland distribution are likely to have high rates of C accumulation and will compensate for some of the losses elsewhere.

  11. Linking Central Metabolism with Increased Pathway Flux: l-Valine Accumulation by Corynebacterium glutamicum

    Radmacher, Eva; Vaitsikova, Adela; Burger, Udo; Krumbach, Karin; Sahm, Hermann; Eggeling, Lothar

    2002-01-01

    Mutants of Corynebacterium glutamicum were made and enzymatically characterized to clone ilvD and ilvE, which encode dihydroxy acid dehydratase and transaminase B, respectively. These genes of the branched-chain amino acid synthesis were overexpressed together with ilvBN (which encodes acetohydroxy acid synthase) and ilvC (which encodes isomeroreductase) in the wild type, which does not excrete l-valine, to result in an accumulation of this amino acid to a concentration of 42 mM. Since l-vali...

  12. Accumulation of Phosphorus-Containing Compounds in Developing Seeds of Low-Phytate Pea (Pisum sativum L. Mutants

    Arun S.K. Shunmugam

    2014-12-01

    Full Text Available Low phytic acid (lpa crops are low in phytic acid and high in inorganic phosphorus (Pi. In this study, two lpa pea genotypes, 1-150-81, 1-2347-144, and their progenitor CDC Bronco were grown in field trials for two years. The lpa genotypes were lower in IP6 and higher in Pi when compared to CDC Bronco. The total P concentration was similar in lpa genotypes and CDC Bronco throughout the seed development. The action of myo-inositol phosphate synthase (MIPS (EC 5.5.1.4 is the first and rate-limiting step in the phytic acid biosynthesis pathway. Aiming at understanding the genetic basis of the lpa mutation in the pea, a 1530 bp open reading frame of MIPS was amplified from CDC Bronco and the lpa genotypes. Sequencing results showed no difference in coding sequence in MIPS between CDC Bronco and lpa genotypes. Transcription levels of MIPS were relatively lower at 49 days after flowering (DAF than at 14 DAF for CDC Bronco and lpa lines. This study elucidated the rate and accumulation of phosphorus compounds in lpa genotypes. The data also demonstrated that mutation in MIPS was not responsible for the lpa trait in these pea lines.

  13. Analysis of ac Surface Photovoltages in Accumulation Region

    Munakata, Chusuke

    1988-05-01

    Equations for ac surface photovoltages (SPVs) excited with a chopped photon beam (PB) in the accumulation region are proposed for such semiconductors as silicon and germanium. Following the previously reported half-sided junction model for the depleted or inverted region, equations for photocurrent density and surface impedance per unit area have been newly deduced. When the surface potential is highly negative in p-type semiconductors, the maximum ac SPV in the accumulation region is limited by the conductance due to majority carrier diffusion flow. This is compared with the strong inversion region, where the mathematically maximum SPV depends upon the minority carrier diffusion flow. The voltage ratio between the two maximum ac SPVs is the same as that previously reported using the different models for dc SPVs excited with a continuous PB.

  14. Cloning and transcriptional analysis of Crepis alpina fatty acid desaturases affecting the biosynthesis of crepenynic acid.

    Nam, Jeong-Won; Kappock, T Joseph

    2007-01-01

    Crepis alpina acetylenase is a variant FAD2 desaturase that catalyses the insertion of a triple bond at the Delta12 position of linoleic acid, forming crepenynic acid in developing seeds. Seeds contain a high level of crepenynic acid but other tissues contain none. Using reverse transcriptase-coupled PCR (RT-PCR), acetylenase transcripts were identified in non-seed C. alpina tissues, which were highest in flower heads. To understand why functional expression of the acetylenase is limited to seeds, genes that affect acetylenase activity by providing substrate (FAD2) or electrons (cytochrome b5), or that compete for substrate (FAD3), were cloned. RT-PCR analysis indicated that the availability of a preferred cytochrome b5 isoform is not a limiting factor. Developing seeds co-express acetylenase and FAD2 isoform 2 (FAD2-2) at high levels. Flower heads co-express FAD2-3 and FAD3 at high levels, and FAD2-2 and acetylenase at moderate levels. FAD2-3 was not expressed in developing seed. Real-time RT-PCR absolute transcript quantitation showed 10(4)-fold higher acetylenase expression in developing seeds than in flower heads. Collectively, the results show that both the acetylenase expression level and the co-expression of other desaturases may contribute to the tissue specificity of crepenynate production. Helianthus annuus contains a Delta12 acetylenase in a polyacetylene biosynthetic pathway, so does not accumulate crepenynate. Real-time RT-PCR analysis showed relatively strong acetylenase expression in young sunflowers. Acetylenase transcription is observed in both species without accumulation of the enzymatic product, crepenynate. Functional expression of acetylenase appears to be affected by competition and collaboration with other enzymes. PMID:17329262

  15. Amino acids

    Amino acids are organic compounds that combine to form proteins . Amino acids and proteins are the building blocks of life. When proteins are digested or broken down, amino acids are left. The human body uses amino acids ...

  16. Uranium accumulation by aquatic macrophyte, Pistia stratiotes

    Uranium accumulation by aquatic macrophyte, Pistia stratiotes from aqueous solution was investigated in laboratory condition. The objective was to evaluate the uranium accumulation potential and adopt the plant in uranium containing medium to improve its uptake capacity. The plant was found to tolerate and grow in the pH range of 3-7. Accumulation of uranium improved with increasing pH and the plant could remove 70% uranium from the medium (20 mg/L) within 24 hours of incubation at pH 5-6. Uptake of uranium on either side of this pH range decreased

  17. Microbial accumulation of uranium, radium, and cesium

    Diverse microbial species varied considerably in their ability to accumulate uranium, cesium, and radium. Mechanistic differences in uranium uptake by Saccharomyces cerevisiae and Pseudomonas aeruginosa were indicated. S. serevisiae exhibited a slow (hours) surface accumulation of uranium which was subject to environmental factors, while P. aeruginosa accumulated uranium rapidly (minutes) as dense intracellular deposits and did not appear to be affected by environmental parameters. Metabolism was not required for uranium uptake by either organism. Cesium and radium were concentrated to a considerably lesser extent than uranium by the several species tested

  18. Geochemistry Model Validation Report: External Accumulation Model

    The purpose of this Analysis and Modeling Report (AMR) is to validate the External Accumulation Model that predicts accumulation of fissile materials in fractures and lithophysae in the rock beneath a degrading waste package (WP) in the potential monitored geologic repository at Yucca Mountain. (Lithophysae are voids in the rock having concentric shells of finely crystalline alkali feldspar, quartz, and other materials that were formed due to entrapped gas that later escaped, DOE 1998, p. A-25.) The intended use of this model is to estimate the quantities of external accumulation of fissile material for use in external criticality risk assessments for different types of degrading WPs: U.S. Department of Energy (DOE) Spent Nuclear Fuel (SNF) codisposed with High Level Waste (HLW) glass, commercial SNF, and Immobilized Plutonium Ceramic (Pu-ceramic) codisposed with HLW glass. The scope of the model validation is to (1) describe the model and the parameters used to develop the model, (2) provide rationale for selection of the parameters by comparisons with measured values, and (3) demonstrate that the parameters chosen are the most conservative selection for external criticality risk calculations. To demonstrate the applicability of the model, a Pu-ceramic WP is used as an example. The model begins with a source term from separately documented EQ6 calculations; where the source term is defined as the composition versus time of the water flowing out of a breached waste package (WP). Next, PHREEQC, is used to simulate the transport and interaction of the source term with the resident water and fractured tuff below the repository. In these simulations the primary mechanism for accumulation is mixing of the high pH, actinide-laden source term with resident water; thus lowering the pH values sufficiently for fissile minerals to become insoluble and precipitate. In the final section of the model, the outputs from PHREEQC, are processed to produce mass of accumulation

  19. Limitation of mitragynine biosynthesis in Mitragyna speciosa (Roxb.) Korth. through tryptamine availability.

    Charoonratanaa, Tossaton; Wungsintaweekul, Juraithip; Pathompak, Pathamaporn; Georgiev, Milen I; Choi, Young Hae; Verpoorte, Robert

    2013-01-01

    Metabolite profiles of Mitragyna speciosa were determined by means of 1H NMR-based and HPLC-based analyses. The results indicated that high contents of secologanin, caffeic acid, gallic acid, epigallocatechin, and mitragynine were accumulated in leaves. In M. speciosa, feedings of tryptamine, tryptophan, phenylalanine or tyrosine significantly increased the mitragynine contents. Feedings of tryptamine and loganin also enhanced the mitragynine accumulation, but feeding of loganin only did not affect the mitragynine level. The mRNA levels of anthranilate synthase alpha subunit (ASA), tryptophan decarboxylase (TDC), and strictosidine synthase (STR) were measured by quantitative real-time polymerase chain reaction (RT-qPCR) in control plants and those exposed to methyl jasmonate (MJ; 10 microM). All genes responded to MJ after a 24-h treatment. The mitragynine contents were also enhanced and corresponded to the transcript levels. From the present results we conclude that a high content of secologanin together with a undetectable level of tryptamine in M. speciosa feature the limitation of mitragynine biosynthesis. Additionally, expression of all the genes limits production of an essential precursor for mitragynine production. PMID:24459773

  20. Activation of AMPKα2 Is Not Required for Mitochondrial FAT/CD36 Accumulation during Exercise

    Monaco, Cynthia; Whitfield, Jamie; Jain, Swati S.; Spriet, Lawrence L.; Bonen, Arend; Holloway, Graham P.

    2015-01-01

    Exercise has been shown to induce the translocation of fatty acid translocase (FAT/CD36), a fatty acid transport protein, to both plasma and mitochondrial membranes. While previous studies have examined signals involved in the induction of FAT/CD36 translocation to sarcolemmal membranes, to date the signaling events responsible for FAT/CD36 accumulation on mitochondrial membranes have not been investigated. In the current study muscle contraction rapidly increased FAT/CD36 on plasma membranes...

  1. LCFA accumulation and biodegradation during anaerobic discontinuous treatment of an oleate-rich wastewater

    Cavaleiro, A. J.; Alves, J.I.; Alves, M.M.

    2007-01-01

    The dynamics of medium and long-chain fatty acids (LCFA) accumulation and biodegradation was studied during the anaerobic treatment of an oleate-rich wastewater. This treatment was made in an upflow sludge bed reactor operated in cycles during 213 days. Five cycles were performed, each one with a feeding phase in continuous and a reaction phase in batch. Saturated and unsaturated fatty acids from C6 to C18 were extracted and analyzed by gas chromatography on biomass samples col...

  2. Soil Copper and Zinc Accumulation and Bioavailability under a Long Term Vineyard Cultivation in South Italy

    Anna Maria Corea

    2011-02-01

    Full Text Available Soil metal contamination, particularly by copper, is a phenomenon which often occurs in the surface layer of vineyard soils, due to the widespread application of Cu-based products in the plant disease management. Our study was focused on soil Cu and Zn accumulation and bioavailability as related to some soil properties under a long term vineyard cultivation, in a D.O.C. wine area of South Italy (Calabria region. Soils selected from different landscape units, ranging from acid to alkaline, under homogeneous climate conditions and vineyard management system, were investigated. Each soil was sampled in both a vineyard and a fallow area, at the depth levels of 0-10 cm, 10-25 cm and 25-50 cm. The experimental data were analysed by ANOVA, correlation and multiple stepwise regression procedures. As expected, the results indicated a contamination of the vineyard soils by Cu due to the repeated application of Cu-based products in the plant disease control, with increments of total Cu content up to 150% against the fallow soils. On the contrary, the results led to exclude any soil Zn pollution due to the vineyard management and to suppose a main pedogenic origin for this metal. According to the relationships between Cu content and soil properties, Cu accumulation was promoted by higher pH, clay and organic matter contents. These soil properties also showed a strong influence on metal bioavailability, which underwent a significant reduction in soils with higher pH and clay contents. A further result of great significance was the adverse impact of soil erosion, enhanced by the application of not suitable management systems in hilly areas, on soil capability to retain polluting metals. Soil pH, organic matter content and texture, as well as soil management system, are key factors in soil capability to limit polluting metal dispersion in the environment.

  3. Soil Copper and Zinc Accumulation and Bioavailability under a Long Term Vineyard Cultivation in South Italy

    Anna Maria Corea

    2007-03-01

    Full Text Available Soil metal contamination, particularly by copper, is a phenomenon which often occurs in the surface layer of vineyard soils, due to the widespread application of Cu-based products in the plant disease management. Our study was focused on soil Cu and Zn accumulation and bioavailability as related to some soil properties under a long term vineyard cultivation, in a D.O.C. wine area of South Italy (Calabria region. Soils selected from different landscape units, ranging from acid to alkaline, under homogeneous climate conditions and vineyard management system, were investigated. Each soil was sampled in both a vineyard and a fallow area, at the depth levels of 0-10 cm, 10-25 cm and 25-50 cm. The experimental data were analysed by ANOVA, correlation and multiple stepwise regression procedures. As expected, the results indicated a contamination of the vineyard soils by Cu due to the repeated application of Cu-based products in the plant disease control, with increments of total Cu content up to 150% against the fallow soils. On the contrary, the results led to exclude any soil Zn pollution due to the vineyard management and to suppose a main pedogenic origin for this metal. According to the relationships between Cu content and soil properties, Cu accumulation was promoted by higher pH, clay and organic matter contents. These soil properties also showed a strong influence on metal bioavailability, which underwent a significant reduction in soils with higher pH and clay contents. A further result of great significance was the adverse impact of soil erosion, enhanced by the application of not suitable management systems in hilly areas, on soil capability to retain polluting metals. Soil pH, organic matter content and texture, as well as soil management system, are key factors in soil capability to limit polluting metal dispersion in the environment.

  4. Aluminium Uptake and Accumulation in the Hyperaccumulator Camellia Oleifera Abel

    ZENG Qi-Long; CHEN Rong-Fu; ZHAO Xue-Qiang; WANG Huo-Yan; SHEN Ren-Fang

    2011-01-01

    Oiltea camellia (Camellia oleifera Abel.), an aluminium (Al) hyperaccumulator, grows well on acid soils in tropical or subtropical areas. In this study, the growth of oiltea camellia in response to Al application and the characteristics of Al uptake and accumulation were investigated using laboratory and field experiments. The growth of oiltea camellia seedlings in the nutrient solution tended to be stimulated by addition of Al. Results of the field experiment showed that oiltea camellia accumulated 11000 mg kg-1 Al in leaves within 10 months, and the average rate of A1 accumulation in new leaves was about 1 100 mg kg-1 month-1; however, the monthly rate varied and was highest in spring and autumn. The results of the laboratory experiment on Al uptake by oiltea camellia seedlings in CaCl2 solutions with various forms of Al showed that large amounts of Al supplied as Al3+ and Al complexes Al-malate (1:1) and Al-F (1:1) were influxed into oiltea camellia roots, whereas Al supplied as Al-citrate (1:1), Al-F (1:6), Al-oxalate (1:3), and Al-oxalate (1:1) complexes exhibited low affinity to oiltea camellia roots. The kinetics of Als+ cumulative uptake in excised roots and intact plants showed a biphasic pattern, with an initial rapid phase followed by a slow phase. The Al cumulative uptake was unaffected by low temperature,which indicated that Al uptake in oiltea camellia was a passive process. The efficient influx of Al into the roots and the high transport rate in specific seasons were presumed to account for the plentiful Al accumulation in leaves of oiltea camellia.

  5. Iron accumulation with age, oxidative stress and functional decline.

    Jinze Xu

    Full Text Available Identification of biological mediators in sarcopenia is pertinent to the development of targeted interventions to alleviate this condition. Iron is recognized as a potent pro-oxidant and a catalyst for the formation of reactive oxygen species in biological systems. It is well accepted that iron accumulates with senescence in several organs, but little is known about iron accumulation in muscle and how it may affect muscle function. In addition, it is unclear if interventions which reduced age-related loss of muscle quality, such as calorie restriction, impact iron accumulation. We investigated non-heme iron concentration, oxidative stress to nucleic acids in gastrocnemius muscle and key indices of sarcopenia (muscle mass and grip strength in male Fischer 344 X Brown Norway rats fed ad libitum (AL or a calorie restricted diet (60% of ad libitum food intake starting at 4 months of age at 8, 18, 29 and 37 months of age. Total non-heme iron levels in the gastrocnemius muscle of AL rats increased progressively with age. Between 29 and 37 months of age, the non-heme iron concentration increased by approximately 200% in AL-fed rats. Most importantly, the levels of oxidized RNA in gastrocnemius muscle of AL rats were significantly increased as well. The striking age-associated increase in non-heme iron and oxidized RNA levels and decrease in sarcopenia indices were all attenuated in the calorie restriction (CR rats. These findings strongly suggest that the age-related iron accumulation in muscle contributes to increased oxidative damage and sarcopenia, and that CR effectively attenuates these negative effects.

  6. Establishment of biological limit value of urinary S-phenylmercapturic acid for occupational exposure to benzene%职业接触苯尿中苯巯基尿酸生物限值研究

    梅勇; 宋世震; 陈斯琦; 叶玉杰; 叶方立

    2009-01-01

    Objective To establish the biological exposure limit values of urinary S-phenylmercap-turic acid (SPMA) for assessing occupational exposure to benzene. Methods Study participants were selected from 55 workers of benzene exposures below 32.5 mg/m~3. The concentration of personal exposure to benzene was measured by gas chromatography and sampled with personal sampler. The urine samples were collected at the end of work shift and individual internal exposure level was evaluated by determination of SPMA in urine by HPLC/MS method. Comparison of external and internal exposure was assessed by the relative internal expo-sure(RIE) index. Results The benzene exposure level ranged from 0.71 to 32.17 mg/m~3 (geometric mean 6.98 mg/m~3, median 7.50 mg/m~3). The urinary SPMA at the end of the work shift were significantly correlated with benzene exposure, Y (μg/g Cr)=-8.625 + 18.367X (mg/m~3), r=0.8035, (P<0.01). According to the occupational exposure limit for benzene in China and calculation of regression equation, the expected value of urinary SPMA was 101.58 μg/g Cr. Mean level of biotransformation of per mg/m~3 benzene to urinary SPMA was 18.23 μg/g Cr and the metabolic efficiencies of benzene transformation to urinary SPMA decreased with benzene exposure in-creased. Conclusion Based on abroad documents and data, biological limit value for occupational exposure to benzene in China is recommended as follows: 100 μg/g Cr (47 μmol/mol Cr) for SPMA in the urine at the end of shift.%目的 研制我国职业接触苯工人尿中苯巯基尿酸(SPMA)的生物限值.方法 在苯作业车间选择空气中苯浓度在32.5 mg/m~3以下接苯工人55人,应用个体采样器采集空气样品,用气相色谱法检测作业者个体苯接触水平,同时采集当日工人班后尿,应用高压液相色谱/质谱法(HPLC/MS)测定尿中SPMA含量以评价苯接触者的内暴露水平,内外暴露水平的比较用相对内暴露指数(RIE)加以评定.结果 接苯工人工作

  7. Sodium accumulation in rice and quinoa

    Full text: Sensitivity to salinity is often attributed to excessive accumulation of Na+ ions in leaf cells. This implies that screening for low Na+ accumulation should result in enhanced tolerance to salt. While this is generally true, there are a number of examples where Na+ accumulation is not the only factor. In rice (Oryza sativa) there is good evidence linking genetically-determined Na+ accumulation with tolerance to salinity, but there are other factors that should be considered, including Cl- accumulation and the inter- and intra-cellular distribution of solutes. In quinoa (Chenopodium quinoa) There are large varietal differences in Na+ accumulation, but smaller differences in salt tolerance. We have studied the genetics of salinity responses in two cultivars of rice, Co39 and Moroberekan. The latter accumulates more Na+ than Co39 and many other rice varieties. Experiments at a range of salt concentrations and with varying Na: Ca ratios showed that Na+ accumulation was initially quite low, but increased with time of exposure to salt. Part of the increase in Na+, and all of the observed increase in K+ concentrations, could be attributed to dehydration of the leaves. Measurements of leaf solute and water potentials indicated that solutes accumulated in the leaf apoplast. This resulted in reduced turgor and increased leaf rolling. Concentrations of Cl- in the leaves were several times higher than those of Na+. QTL analysis of a hybrid population derived from these varieties revealed a major QTL for leaf Na+ accumulation on chromosome 1 at a position where QTL for salt tolerance and Na+ uptake have been identified by other groups. No QTL were identified for Cl- accumulation. Is rice relatively salt sensitive because it accumulates low concentrations of Na+ under genetic control, or is Cl- (present at much higher concentrations) responsible for salt damage. We are looking for rice accessions that differ in Cl- accumulation to find Cl- QTL. Perhaps it does not

  8. Rock bed heat accumulators. Final report

    Riaz, M.

    1977-12-01

    The principal objectives of the research program on rock bed heat accumulators (or RBHA) are: (1) to investigate the technical and economic feasibility of storing large amounts of thermal energy (in the tens of MWt range) at high temperature (up to 500/sup 0/C) over extended periods of time (up to 6 months) using native earth or rock materials; (2) to conduct studies to establish the performance characteristics of large rock bed heat accumulators at various power and temperature levels compatible with thermal conversion systems; and (3) to assess the materials and environmental problems associated with the operation of such large heat accumulators. Results of the study indicate that rock bed heat accumulators for seasonal storage are both technically and economically feasible, and hence could be exploited in various applications in which storage plays an essential role such as solar power and total energy systems, district and cogeneration heating systems.

  9. Factors influencing the cardiac MIBG accumulation

    Following factors possibly influencing the cardiac MIBG accumulation were examined mainly in mice. 1. The specific activity of the MIBG (meta-iodo-benzyl guanidine) on the neuronal and non-neuronal fractions. 2. Motor restriction stress on MIBG accumulation and washout. 3. Loading and restriction of sodium chloride on the accumulation and effect of suppression of renin-angiotensin system. 4. Examinations in Dahl rats. 125I- or 131I-MIBG was intravenously administered to mice at 74 kBq. At 30 min or 4 hr after administration, mice were sacrificed and their left ventricles were dissected out for measurement of radioactivity in a liquid scintillation counter. Salt-sensitive and -resistant Dahl rats were given with 37 MBq of 123I-MIBG and cardiac radioactivity was measured externally for calculation of washout. Factors examined were found highly correlated with the accumulation of MIBG and measurement of its washout was considered useful for evaluating sympathetic activity. (K.H.)

  10. Accumulation of nickel in transgenic tobacco

    Sidik, Nik Marzuki; Othman, Noor Farhan

    2013-11-01

    The accumulation of heavy metal Ni in the roots and leaves of four T1 transgenic lines of tobacco (T(1)20E, T(1)24C, T(1)18B1 and T(1)20B) expressing eiMT1 from E.indica was assessed. The aim of the study was to investigate the level of Ni accumulation in the leaves and roots of each transgenic lines and to evaluate the eligibility of the plants to be classified as a phytoremediation agent. All of the transgenic lines showed different ability in accumulating different metals and has translocation factor (TF) less than 1 (TFtransgenic lines, transgenic line T(1)24C showed the highest accumulation of Ni (251.9 ± 0.014 mg/kg) and the lowest TF value (TFT(1)24C=0.0875) at 60 ppm Ni.

  11. Role and influence of mycorrhizal fungi on radiocesium accumulation by plants

    This review summarizes current knowledge on the contribution of mycorrhizal fungi to radiocesium immobilization and plant accumulation. These root symbionts develop extended hyphae in soils and readily contribute to the soil-to-plant transfer of some nutrients. Available data show that ecto-mycorrhizal (ECM) fungi can accumulate high concentration of radiocesium in their extraradical phase while radiocesium uptake and accumulation by arbuscular mycorrhizal (AM) fungi is limited. Yet, both ECM and AM fungi can transport radiocesium to their host plants, but this transport is low. In addition, mycorrhizal fungi could thus either store radiocesium in their intraradical phase or limit its root-to-shoot translocation. The review discusses the impact of soil characteristics, and fungal and plant transporters on radiocesium uptake and accumulation in plants, as well as the potential role of mycorrhizal fungi in phytoremediation strategies

  12. Accumulation of nanocarriers in the ovary

    Schädlich, Andreas; Hoffmann, Stefan; Mueller, Thomas;

    2012-01-01

    Several nanocarrier systems are frequently used in modern pharmaceutical therapies. Within this study a potential toxicity risk of all nanoscaled drug delivery systems was found. An accumulation of several structurally different nanocarriers but not of soluble polymers was detected in rodent...... vivo multispectral fluorescence imaging and confocal laser scanning microscopy. The findings of this study emphasise the role of early and comprehensive in vivo studies in pharmaceutical research. Nanocarrier accumulation in the ovaries may also comprise an important toxicity issue in humans...

  13. Development of the flow controlled accumulator

    Mitsubishi is developing the new type accumulator incorporating the technology of Fluidics as one of seeds for the improved safety of the new generation PWR (Pressurized Water Reactor) plants. This accumulator employs a vortex flow control device named a vortex damper as a Fluidic device for the simplification of the safety systems. We have done a basic experimental study to develop the vortex damper and gotten satisfactory results. This paper describes the results of the basic experiments of the vortex dampers. (author)

  14. Plastic accumulation in the mediterranean sea

    Andrés Cózar; Marina Sanz-Martín; Elisa Martí; Ignacio González-Gordillo, J; Bárbara Ubeda; José Á Gálvez; Xabier Irigoien; Duarte, Carlos M.

    2015-01-01

    Copyright: © 2015 Cózar et al. Concentrations of floating plastic were measured throughout the Mediterranean Sea to assess whether this basin can be regarded as a great accumulation region of plastic debris. We found that the average density of plastic (1 item per 4 m2), as well as its frequency of occurrence (100% of the sites sampled), are comparable to the accumulation zones described for the five subtropical ocean gyres. Plastic debris in the Mediterranean surface waters was dominated by ...

  15. Financial Literacy, Schooling, and Wealth Accumulation

    Behrman, Jere R.; Mitchell, Olivia S.; Cindy Soo; David Bravo

    2010-01-01

    Financial literacy and schooling attainment have been linked to household wealth accumulation. Yet prior findings may be biased due to noisy measures of financial literacy and schooling, as well as unobserved factors such as ability, intelligence, and motivation that could enhance financial literacy and schooling but also directly affect wealth accumulation. We use a new household dataset and an instrumental variables approach to isolate the causal effects of financial literacy and schooling ...

  16. Plastic Accumulation in the Mediterranean Sea

    Cózar, Andrés; Sanz-Martín, Marina; Martí, Elisa; González-Gordillo, J. Ignacio; Ubeda, Bárbara; Gálvez, José Á.; Irigoien, Xabier; Duarte, Carlos M.

    2015-01-01

    Concentrations of floating plastic were measured throughout the Mediterranean Sea to assess whether this basin can be regarded as a great accumulation region of plastic debris. We found that the average density of plastic (1 item per 4 m2), as well as its frequency of occurrence (100% of the sites sampled), are comparable to the accumulation zones described for the five subtropical ocean gyres. Plastic debris in the Mediterranean surface waters was dominated by millimeter-sized fragments, but...

  17. Incorporation of oxygen into abscisic acid and phaseic acid for molecular oxygen

    Abscisic acid accumulates in detached, wilted leaves of Xanthium strumariu. When these leaves are subsequently rehydrated, phaseic acid, a catabolite of abscisic acid, accumulates. Analysis by gas chromatography-mass spectrometry of phaseic acid isolated from stressed and subsequently rehydrated leaves placed in an atmosphere containing 20% 18O2 and 80% N2 indicates that one atom of 18O is incorporated in the 6'-hydroxymethyl group of phaseic acid. This suggests that the enzyme that converts abscisic acid to phaseic acid is an oxygenase. Analysis by gas chromatography-mass spectrometry of abscisic acid isolated from stressed leaves kept in an atmosphere containing 18O2 indicates that one atom of 18O is presented in the carboxyl group of abscisic acid. Thus, when abscisic acid accumulates in water-streesed leaves, only one of the four oxygens present in the abscisic acid molecule is derived from molecular oxygen. This suggest that either (a) the oxygen present in the 1'-, 4'-, and one of the two oxygens at the 1-position of abscisic acid arise from water, or (b) there exists a stored precursor with oxygen atoms already present in the 1'- and 4'-positions of abscisic acid which is converted to abscisic acid under conditions of water stress. 17 references, 2 figures, 1 tables

  18. Arbuscular mycorrhizal fungus-promoted accumulation of two new triterpenoids in cucumber roots.

    Akiyama, Kohki; Hayashi, Hideo

    2002-04-01

    Cucumber (Cucumis sativus L.) roots were analyzed by HPLC and TLC for their levels of secondary metabolites upon inoculation with the arbuscular mycorrhizal fungus, Glomus caledonium. Three compounds in EtOAc extracts from the mycorrhizal roots showed significant increases six weeks after inoculation. These compounds were isolated by column chromatography and determined to be two novel triterpenes, 2beta-hydroxybryonolic acid (2beta,3beta-dihydroxy-D:C-friedoolean-8-en-29-oic acid) and 3beta-bryoferulic acid [3beta-O-trans-ferulyl-D:C-friedooleana-7,9(11)-diene-29-oic acid], and the known triterpene, bryonolic acid, by spectroscopic methods. Time-course experiments showed that the levels of the three terpenoids in cucumber roots were significantly increased by the application of a 53-microm sieving from a soil inoculum of the arbuscular mycorrhizal fungus containing soil microbes but no mycorrhizal fungi, and that mycorrhizal colonization further promoted the terpenoid accumulation. Inoculation with Glomus mosseae also enhanced the accumulation of the triterpenes, whereas no accumulation was observed by inoculating with the fungal pathogen, Fusarium oxysporum f. sp. cucumerinum. 2Beta-hydroxybryonolic acid was also isolated from the roots of melon and watermelon. PMID:12036048

  19. The Long-Run Effects of Structural Change and the Treatment of International Capital Accumulation, Mobility and Ownership

    George Verikios; Kevin Hanslow

    2009-01-01

    Taking a commonly-used and commonly-available trade policy model as our starting point, we examine the long-run effects of large-scale structural change with and without international capital accumulation, mobility and ownership. We demonstrate the relative merits and limitations of different treatments of international capital accumulation, mobility and ownership. In doing so, we present a treatment of international capital accumulation, mobility and ownership that gives policy analysts an a...

  20. AMP-activated protein kinase is required for the anti-adipogenic effects of alpha-linolenic acid

    Zhou, Xihong; Wu, Weiche; Chen, Jingqing; Wang, Xinxia; Wang, Yizhen

    2015-01-01

    Background n-3 long chain polyunsaturated fatty acid (n-3 LC PUFA) increases β-oxidation and limits lipid accumulation in adipocytes. The current study was conducted to determine whether their precursor alpha-linolenic acid (ALA) could also exert the above effects and how AMP-activated protein kinase (AMPK) was involved. Methods AMPKα1−/−, AMPKα2−/− mice and wild-type (WT) mice were fed a high-fat diet (HFD) or HFD with ALA. Body weight was recorded weekly and serum was collected. Adipocytes ...