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Sample records for accumulating organisms paos

  1. Impact of salinity on the anaerobic metabolism of phosphate-accumulating organisms (PAO) and glycogen-accumulating organisms (GAO).

    Welles, L; Lopez-Vazquez, C M; Hooijmans, C M; van Loosdrecht, M C M; Brdjanovic, D

    2014-09-01

    The use of saline water as secondary quality water in urban environments for sanitation is a promising alternative towards mitigating fresh water scarcity. However, this alternative will increase the salinity in the wastewater generated that may affect the biological wastewater treatment processes, such as biological phosphorus removal. In addition to the production of saline wastewater by the direct use of saline water in urban environments, saline wastewater is also generated by some industries. Intrusion of saline water into the sewers is another source of salinity entering the wastewater treatment plant. In this study, the short-term effects of salinity on the anaerobic metabolism of phosphate-accumulating organisms (PAO) and glycogen-accumulating organisms (GAO) were investigated to assess the impact of salinity on enhanced biological phosphorus removal. Hereto, PAO and GAO cultures enriched at a relatively low salinity level (0.02 % W/V) were exposed to salinity concentrations of up to 6 % (as NaCl) in anaerobic batch tests. It was demonstrated that both PAO and GAO are affected by higher salinity levels, with PAO being the more sensitive organisms to the increasing salinity. The maximum acetate uptake rate of PAO decreased by 71 % when the salinity increased from 0 to 1 %, while that of GAO decreased by 41 % for the same salinity increase. Regarding the stoichiometry of PAO, a decrease in the P-release/HAc uptake ratio accompanied with an increase in the glycogen consumption/HAc uptake ratio was observed for PAO when the salinity increased from 0 to 2 % salinity, indicating a metabolic shift from a poly-P-dependent to a glycogen-dependent metabolism. The anaerobic maintenance requirements of PAO and GAO increased as the salinity concentrations risen up to 4 % salinity. PMID:24831025

  2. The effect of substrate competition on the metabolism of polyphosphate accumulating organisms (PAOs).

    Carvalheira, Mónica; Oehmen, Adrian; Carvalho, Gilda; Reis, Maria A M

    2014-11-01

    The type of carbon source present in the wastewater is one factor that affects the competition between polyphosphate accumulating organisms (PAO) and glycogen accumulating organisms (GAO) and therefore, the efficiency of the enhanced biological phosphorus removal (EBPR) process. This study investigated the impact of the carbon source composition on the anaerobic and aerobic kinetics of PAOs and the EBPR performance of an 85% PAO enrichment. When both acetate (HAc) and propionate (HPr) were present, propionate was depleted more quickly, with a constant uptake rate of 0.18 ± 0.02 C-mol/(C-mol biomass·h), while the acetate uptake rate decreased with an increase in propionate concentration, due to the substrate competition between acetate and propionate. The metabolic model for PAOs was modified to incorporate the anaerobic substrate competition effect. The aerobic rates for phosphorus (P) uptake, glycogen production and polyhydroxyalkanoates (PHA) degradation were within the same range for all tests, indicating that these rates are essentially independent of the acetate and propionate concentration, simplifying the calibration procedure for metabolic models. The metabolic model applied to describe the anaerobic and aerobic activity agreed well with the experimental data of HAc, HPr, P, PHA and biomass growth. The low glycogen consumption observed suggest that some reducing equivalents were generated anaerobically through the TCA cycle. The results of this work suggest that the propionate uptake kinetics by PAOs can provide them an advantage over GAOs in EBPR systems, even when the propionate fraction of the influent is relatively low. PMID:25051162

  3. 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

  4. The Competition between Polyphosphate-Accumulating Organisms and Glycogen-Accumulating Organisms: Temperature Effects and Modelling

    López Vázquez, C.M.

    2009-01-01

    Due to relatively high phosphorus removal efficiency and economy, the enhanced biological phosphorus removal (EBPR) in activated sludge wastewater treatment systems is a widely applied process to control and prevent eutrophication in surface water bodies. However, the EBPR process can be prone to suffer of upsets and deterioration. Since glycogen-accumulating organisms (GAO) compete with polyphosphate-accumulating organisms (PAO), which are the microorganisms that perform the biological phosp...

  5. TIME DEPENDENT ACCUMULATION OF NICOTINE DERIVATIVES IN THE CULTURE MEDIUM OF ARTHROBACTER NICOTINOVORANS pAO1

    Răzvan Ștefan Boiangiu

    2014-12-01

    Full Text Available Previous studies have shown that the metabolic intermediate 6-hidroxy-D-nicotine (6HNic found in the Arthrobacter nicotinovorans pAO1+ nicotine catabolic pathway has the ability to bind nicotinic acetylcholine receptors and to sustain spatial memory in rats. These properties make 6HNic a valuable compound with some potential for medical applications, thereby a suitable, simple and efficient method for producing 6-hidroxy-D-nicotine is necessary. Here, we focus on identifying the best moment for harvesting A. nicotinovorans cells in order to directly convert nicotine to 6HNic with the best yield.  The growth of  A. nicotinovorans pAO1+ was monitored and the correlation between the growth phases and nicotine metabolism was established. After about 5 hours of lag,the strain entered the log phase and was fully grown after 10 hours. The nicotine concentration began to drop dramatically as the pAO1+ culture reached saturation and was depleted in 5 hours. As the nicotine concentration dropped, 6HNic began to accumulate, reaching the maximum levels after about 11 hours of growth. Two other products could be detected by HPLC, one which was identified as the nicotine-blue (NB pigment and a second a still unknown end-product. 

  6. Modelling the metabolic shift of polyphosphate-accumulating organisms.

    Acevedo, B; Borrás, L; Oehmen, A; Barat, R

    2014-11-15

    Enhanced biological phosphorus removal (EBPR) is one of the most important methods of phosphorus removal in municipal wastewater treatment plants, having been described by different modelling approaches. In this process, the PAOs (polyphosphate accumulating organisms) and GAOs (glycogen accumulating organisms) compete for volatile fatty acids uptake under anaerobic conditions. Recent studies have revealed that the metabolic pathways used by PAOs in order to obtain the energy and the reducing power needed for polyhydroxyalkanoates synthesis could change depending on the amount of polyphosphate stored in the cells. The model presented in this paper extends beyond previously developed metabolic models by including the ability of PAO to change their metabolic pathways according to the content of poly-P available. The processes of the PAO metabolic model were adapted to new formulations enabling the change from P-driven VFA uptake to glycogen-driven VFA uptake using the same process equations. The stoichiometric parameters were changed from a typical PAO coefficient to a typical GAO coefficient depending on the internal poly-P with Monod-type expressions. The model was calibrated and validated with seven experiments under different internal poly-P concentrations, showing the ability to correctly represent the PAO metabolic shift at low poly-P concentrations. The sensitivity and error analysis showed that the model is robust and has the ability to describe satisfactorily the change from one metabolic pathway to the other one, thereby encompassing a wider range of process conditions found in EBPR plants. PMID:25123437

  7. Accumulibacter clades Type I and II performing kinetically different glycogen-accumulating organisms metabolisms for anaerobic substrate uptake.

    Welles, L; Tian, W D; Saad, S; Abbas, B; Lopez-Vazquez, C M; Hooijmans, C M; van Loosdrecht, M C M; Brdjanovic, D

    2015-10-15

    The anaerobic acetate (HAc) uptake stoichiometry of phosphorus-accumulating organisms (PAO) in enhanced biological phosphorus removal (EBPR) systems has been an extensive subject of study due to the highly variable reported stoichiometric values (e.g. anaerobic P-release/HAc-uptake ratios ranging from 0.01 up to 0.93 P-mol/C-mol). Often, such differences have been explained by the different applied operating conditions (e.g. pH) or occurrence of glycogen-accumulating organisms (GAO). The present study investigated the ability of biomass highly enriched with specific PAO clades ('Candidatus Accumulibacter phosphatis' Clade I and II, hereafter PAO I and PAO II) to adopt a GAO metabolism. Based on long-term experiments, when Poly-P is not stoichiometrically limiting for the anaerobic VFA uptake, PAO I performed the typical PAO metabolism (with a P/HAc ratio of 0.64 P-mol/C-mol); whereas PAO II performed a mixed PAO-GAO metabolism (showing a P/HAc ratio of 0.22 P-mol/C-mol). In short-term batch tests, both PAO I and II gradually shifted their metabolism to a GAO metabolism when the Poly-P content decreased, but the HAc-uptake rate of PAO I was 4 times lower than that of PAO II, indicating that PAO II has a strong competitive advantage over PAO I when Poly-P is stoichiometrically limiting the VFA uptake. Thus, metabolic flexibility of PAO clades as well as their intrinsic differences are additional factors leading to the controversial anaerobic stoichiometry and kinetic rates observed in previous studies. From a practical perspective, the dominant type of PAO prevailing in full-scale EBPR systems may affect the P-release processes for biological or combined biological and chemical P-removal and recovery and consequently the process performance. PMID:26189167

  8. Isolation and Identification of Phosphate-accumulating Strain PAO3-1 and Its Phosphorus Removal Characteristics

    LIU Ya-nan; XUE Gang; SHI Feng-hua; YU Shui-li

    2007-01-01

    A phosphate-accumulating bacteria strain PAO3-1 was isolated from biological phosphorus removal sludge supplied with sodium acetate as carbon source under stable performance. This strain has good enhanced biological phosphorus removal effect on normal activated sludge system. Phosphorus removal ratio was raised form 44%with no added strain to more than 82% with strain strengthening biological phosphorus removal. It is identified to be AlcaUgenes sp. according to its morphology,biochemical characteristics and 16S rDNA sequence analysis. The cell of strain PAO3-1 is straight bacilli form, 0.4×1.1 μm, no flagellum, gram negative and special aerobiotic. The optimal temperature and pH for growth are 32℃-37℃ and 5.5-9.5, respectively. The shape of slant clone is feathery. The phosphate situation, which was 76. 5% higher than that in non-starving situation. Its phosphate release rate of log course in anaerobic phase and in culture without phosphorus was lower than that in log course.

  9. Metabolic characteristics of a glycogen-accumulating organism in Defluviicoccus cluster II revealed by comparative genomics.

    Wang, Zhiping; Guo, Feng; Mao, Yanping; Xia, Yu; Zhang, Tong

    2014-11-01

    Glycogen-accumulating organisms (GAOs) may compete with phosphate-accumulating organisms (PAOs) for short-chain fatty acids (VFAs) in anaerobic polyhydroxyalkanoates (PHA) synthesis, but no consequently aerobic polyphosphate accumulation in enhanced biological phosphorus removal (EBPR) process, thus deteriorating the EBPR process. They are detected frequently in the deteriorated EBPR process, but their metabolisms are still far from our comprehensions for there is seldom pure culture. In this study, a nearly complete draft genome of a GAOs in Defluviicoccus cluster II, GAO-HK, is recruited from the metagenome of activated sludge in a full-scale industrial anoxic/aerobic wastewater plant. Comparative genomics reveal similar metabolisms of PHA and glycogen in GAOs of GAO-HK, Defluviicoccus tetraformis TFO71 (TFO71) and Competibacter phosphatis clade IIA (CPIIA), and PAOs of Accumulibacter clade IIA UW-1 (UW-1) and Tetrasphaera elongata Lp2 (Lp2). Although there are similar gene cassettes related with polyphosphate metabolism in these GAOs and PAOs, especially for Defluviicoccus-relative bacteria and UW-1, ppk1 in GAOs are diverse from those in the identified PAOs, implying the difference of polyphosphate metabolism in GAOs and PAOs. Additionally, genes related to the dissimilatory denitrification are absent in TFO71 and GAO-HK, implying that additional nitrate or nitrite may favor PAOs over Defluviicoccus-relative GAOs. Therefore, PAOs suffering from competition of Defluviicoccus-relative GAOs might be rescued with the additional nitrate/nitrite, which is important to improve the stability of EBPR processes. PMID:24889288

  10. Calcium effect on the metabolic pathway of phosphorus accumulating organisms in enhanced biological phosphorus removal systems.

    Zhang, Hai-Ling; Sheng, Guo-Ping; Fang, Wei; Wang, Yong-Peng; Fang, Cai-Yun; Shao, Li-Min; Yu, Han-Qing

    2015-11-01

    Phosphorus accumulating organisms (PAOs) have been found to act as glycogen-accumulating organisms (GAOs) under certain conditions, thus, the deterioration in the performance of enhanced biological phosphorus removal systems is not always attributed to the proliferation of GAOs. In this work, the effects of calcium on the metabolic pathway of PAOs were explored. It was found that when the influent Ca(2+) concentration was elevated, the tendency and extent of extracellular calcium phosphate precipitation increased, and the intracellular inert Ca-bound polyphosphate was synthesized, while the microbial population remained almost unchanged. The changes in the ratios of phosphorus released/acetate uptaken, the glycogen degraded/acetate uptaken and the poly-β-hydroxyalkanoates synthesized/acetate uptaken during the anaerobic period confirm that, as the influent Ca(2+) concentration was increased, the polyphosphate-accumulating metabolism was partially shifted to the glycogen-accumulating metabolism. At an influent Ca(2+) around 50 mg/L, in addition to the extracellular calcium phosphate precipitation, the intracellular inert Ca-bound polyphosphate synthesis might also be involved in the metabolic change of PAOs. The results of the present work would be beneficial to better understand the biochemical metabolism of PAOs in enhanced biological phosphorus removal systems. PMID:26233656

  11. Impact of nitrite on aerobic phosphorus uptake by poly-phosphate accumulating organisms in enhanced biological phosphorus removal sludges.

    Zeng, Wei; Li, Boxiao; Yang, Yingying; Wang, Xiangdong; Li, Lei; Peng, Yongzhen

    2014-02-01

    Impact of nitrite on aerobic phosphorus (P) uptake of poly-phosphate accumulating organisms (PAOs) in three different enhanced biological phosphorus removal (EBPR) systems was investigated, i.e., the enriched PAOs culture fed with synthetic wastewater, the two lab-scale sequencing batch reactors (SBRs) treating domestic wastewater for nutrient removal through nitrite-pathway nitritation and nitrate-pathway nitrification, respectively. Fluorescence in situ hybridization results showed that PAOs in the three sludges accounted for 72, 7.6 and 6.5% of bacteria, respectively. In the enriched PAOs culture, at free nitrous acid (FNA) concentration of 0.47 × 10(-3) mg HNO₂-N/L, aerobic P-uptake and oxidation of intercellular poly-β-hydroxyalkanoates were both inhibited. Denitrifying phosphorus removal under the aerobic conditions was observed, indicating the existence of PAOs using nitrite as electron acceptor in this culture. When the FNA concentration reached 2.25 × 10(-3) mg HNO2-N/L, denitrifying phosphorus removal was also inhibited. And the inhibition ceased once nitrite was exhausted. Corresponding to both SBRs treating domestic wastewater with nitritation and nitrification pathway, nitrite inhibition on aerobic P-uptake by PAOs did not occur even though FNA concentration reached 3 × 10(-3) and 2.13 × 10(-3) mg HNO₂-N/L, respectively. Therefore, PAOs taken from different EBPR activated sludges had different tolerance to nitrite. PMID:23771179

  12. “Candidatus Propionivibrio aalborgensis”: A Novel Glycogen Accumulating Organism Abundant in Full-Scale Enhanced Biological Phosphorus Removal Plants

    Albertsen, Mads; McIlroy, Simon Jon; Stokholm-Bjerregaard, Mikkel;

    2016-01-01

    Enhanced biological phosphorus removal (EBPR) is widely used to remove phosphorus from wastewater. The process relies on polyphosphate accumulating organisms (PAOs) that are able to take up phosphorus in excess of what is needed for growth, whereby phosphorus can be removed from the wastewater...

  13. Characterisation of Phosphate Accumulating Organisms and Techniques for Polyphosphate Detection: A Review

    Tarayre, Cédric; Nguyen, Huu-Thanh; Brognaux, Alison; Delepierre, Anissa; De Clercq, Lies; Charlier, Raphaëlle; Michels, Evi; Meers, Erik; Delvigne, Frank

    2016-01-01

    Phosphate minerals have long been used for the production of phosphorus-based chemicals used in many economic sectors. However, these resources are not renewable and the natural phosphate stocks are decreasing. In this context, the research of new phosphate sources has become necessary. Many types of wastes contain non-negligible phosphate concentrations, such as wastewater. In wastewater treatment plants, phosphorus is eliminated by physicochemical and/or biological techniques. In this latter case, a specific microbiota, phosphate accumulating organisms (PAOs), accumulates phosphate as polyphosphate. This molecule can be considered as an alternative phosphate source, and is directly extracted from wastewater generated by human activities. This review focuses on the techniques which can be applied to enrich and try to isolate these PAOs, and to detect the presence of polyphosphate in microbial cells. PMID:27258275

  14. Characterisation of Phosphate Accumulating Organisms and Techniques for Polyphosphate Detection: A Review

    Cédric Tarayre

    2016-05-01

    Full Text Available Phosphate minerals have long been used for the production of phosphorus-based chemicals used in many economic sectors. However, these resources are not renewable and the natural phosphate stocks are decreasing. In this context, the research of new phosphate sources has become necessary. Many types of wastes contain non-negligible phosphate concentrations, such as wastewater. In wastewater treatment plants, phosphorus is eliminated by physicochemical and/or biological techniques. In this latter case, a specific microbiota, phosphate accumulating organisms (PAOs, accumulates phosphate as polyphosphate. This molecule can be considered as an alternative phosphate source, and is directly extracted from wastewater generated by human activities. This review focuses on the techniques which can be applied to enrich and try to isolate these PAOs, and to detect the presence of polyphosphate in microbial cells.

  15. Polyphosphate- and glycogen-accumulating organisms in one EBPR system for liquid dairy manure.

    Liu, Ze-Hua; Pruden, Amy; Ogejo, Jactone Arogo; Knowlton, Katharine F

    2014-07-01

    Two enhanced biological phosphorus removal (EBPR) sequencing batch reactors (SBR1, SBR2) treating liquid dairy manure were operated with the same hydraulic retention time (HRT) and solids retention time (SRT), but with different aeration cycles. During eight months of operation, both SBRs achieved good removal of total phosphorus (P) (TP; 56.8 and 73.5% for SBR1 and SBR2 respectively) and of orthophosphate (OP; 76.2 vs. 82.7%, P < 0.05). Growth dynamics of presumptive phosphate-accumulating organisms (PAOs) and glycogen-accumulating organisms (GAOs) were examined by quantitative polymerase chain reaction (qPCR). SBR1 was enriched with a greater abundance of PAOs while SBR2 was characterized by a greater abundance of GAOs. These results demonstrate the capability of EBPR of dairy manure and challenge conventional wisdom, since greater abundance of PAOs in EBPR system was not associated with improved OP removal and greater abundance of GAOs did not indicate deterioration of the EBPR system. PMID:25112034

  16. "Candidatus Propionivibrio aalborgensis": A Novel Glycogen Accumulating Organism Abundant in Full-Scale Enhanced Biological Phosphorus Removal Plants.

    Albertsen, Mads; McIlroy, Simon J; Stokholm-Bjerregaard, Mikkel; Karst, Søren M; Nielsen, Per H

    2016-01-01

    Enhanced biological phosphorus removal (EBPR) is widely used to remove phosphorus from wastewater. The process relies on polyphosphate accumulating organisms (PAOs) that are able to take up phosphorus in excess of what is needed for growth, whereby phosphorus can be removed from the wastewater by wasting the biomass. However, glycogen accumulating organisms (GAOs) may reduce the EBPR efficiency as they compete for substrates with PAOs, but do not store excessive amounts of polyphosphate. PAOs and GAOs are thought to be phylogenetically unrelated, with the model PAO being the betaproteobacterial "Candidatus Accumulibacter phosphatis" (Accumulibacter) and the model GAO being the gammaproteobacterial "Candidatus Competibacter phosphatis". Here, we report the discovery of a GAO from the genus Propionivibrio, which is closely related to Accumulibacter. Propionivibrio sp. are targeted by the canonical fluorescence in situ hybridization probes used to target Accumulibacter (PAOmix), but do not store excessive amounts of polyphosphate in situ. A laboratory scale reactor, operated to enrich for PAOs, surprisingly contained co-dominant populations of Propionivibrio and Accumulibacter. Metagenomic sequencing of multiple time-points enabled recovery of near complete population genomes from both genera. Annotation of the Propionivibrio genome confirmed their potential for the GAO phenotype and a basic metabolic model is proposed for their metabolism in the EBPR environment. Using newly designed fluorescence in situ hybridization (FISH) probes, analyses of full-scale EBPR plants revealed that Propionivibrio is a common member of the community, constituting up to 3% of the biovolume. To avoid overestimation of Accumulibacter abundance in situ, we recommend the use of the FISH probe PAO651 instead of the commonly applied PAOmix probe set. PMID:27458436

  17. “Candidatus Propionivibrio aalborgensis”: A Novel Glycogen Accumulating Organism Abundant in Full-Scale Enhanced Biological Phosphorus Removal Plants

    Albertsen, Mads; McIlroy, Simon J.; Stokholm-Bjerregaard, Mikkel; Karst, Søren M.; Nielsen, Per H.

    2016-01-01

    Enhanced biological phosphorus removal (EBPR) is widely used to remove phosphorus from wastewater. The process relies on polyphosphate accumulating organisms (PAOs) that are able to take up phosphorus in excess of what is needed for growth, whereby phosphorus can be removed from the wastewater by wasting the biomass. However, glycogen accumulating organisms (GAOs) may reduce the EBPR efficiency as they compete for substrates with PAOs, but do not store excessive amounts of polyphosphate. PAOs and GAOs are thought to be phylogenetically unrelated, with the model PAO being the betaproteobacterial “Candidatus Accumulibacter phosphatis” (Accumulibacter) and the model GAO being the gammaproteobacterial “Candidatus Competibacter phosphatis”. Here, we report the discovery of a GAO from the genus Propionivibrio, which is closely related to Accumulibacter. Propionivibrio sp. are targeted by the canonical fluorescence in situ hybridization probes used to target Accumulibacter (PAOmix), but do not store excessive amounts of polyphosphate in situ. A laboratory scale reactor, operated to enrich for PAOs, surprisingly contained co-dominant populations of Propionivibrio and Accumulibacter. Metagenomic sequencing of multiple time-points enabled recovery of near complete population genomes from both genera. Annotation of the Propionivibrio genome confirmed their potential for the GAO phenotype and a basic metabolic model is proposed for their metabolism in the EBPR environment. Using newly designed fluorescence in situ hybridization (FISH) probes, analyses of full-scale EBPR plants revealed that Propionivibrio is a common member of the community, constituting up to 3% of the biovolume. To avoid overestimation of Accumulibacter abundance in situ, we recommend the use of the FISH probe PAO651 instead of the commonly applied PAOmix probe set. PMID:27458436

  18. A GAO hiding among the PAO: The role of the Propionivibrio spp. in biological phosphorus removal

    McIlroy, Simon Jon; Albertsen, Mads; Stokholm-Bjerregaard, Mikkel;

    Enhanced biological phosphorus removal (EBPR) is widely used to remove phosphorus from wastewater. The process relies on polyphosphate accumulating organisms (PAOs) that are able to take up phosphorus in excess of what is needed for growth, whereby phosphorus can be removed from the wastewater...

  19. Naturally Ocurring Polyphosphate-accumulating Bacteria in Benthic Biofilms

    Locke, N. A.; Saia, S. M.; Walter, M. T.; Carrick, H. J.; Buda, A. R.; Regan, J. M.

    2014-12-01

    Polyphosphate accumulating organisms (PAOs), known to store excess phosphorus (P) as polyphosphate (poly-P), influence P transport in the environment. Enhanced biological phosphorus removal (EBPR) from wastewater has long served as a basis to study bacterial PAOs, yet little research has genetically identified similar organisms in natural settings. Aerobic/anaerobic cycles, used to select for PAOs in EBPR, can result from changing environmental conditions such as night/day cycles for benthic biofilms. Benthic biofilms from eight Pennsylvanian streams were studied for naturally-occurring bacterial PAOs similar to those typically found in EBPR systems. PAOs were confirmed in the benthic biofilms by a characteristic yellow fluorescent emission from DAPI staining. Cells containing yellow fluorescence were separated from the rest of the sample using a flow cytometer, resulting in a physically enriched culture of PAOs from the benthic biofilms. Amplicon-based metagenomic sequencing will reveal the phylogeny of bacteria responsible for poly-P accumulation in these benthic biofilms. Sequencing data will be used to develop fluorescent in-situ hybridization (FISH) probes, and hybridizations will be performed on DAPI-stained cells to confirm poly-P accumulation by targeted phylotypes. Identifying PAOs in natural settings is a critical step towards studying environments that support high concentrations of PAOs, serving as significant factors in the P cycle. PAOs can then be connected to P transport models to help understand and mitigate P pollution in agricultural watersheds.

  20. Impact of salinity on the aerobic metabolism of phosphate-accumulating organisms.

    Welles, L; Lopez-Vazquez, C M; Hooijmans, C M; van Loosdrecht, M C M; Brdjanovic, D

    2015-04-01

    The use of saline water in urban areas for non-potable purposes to cope with fresh water scarcity, intrusion of saline water, and disposal of industrial saline wastewater into the sewerage lead to elevated salinity levels in wastewaters. Consequently, saline wastewater is generated, which needs to be treated before its discharge into surface water bodies. The objective of this research was to study the effects of salinity on the aerobic metabolism of phosphate-accumulating organisms (PAO), which belong to the microbial populations responsible for enhanced biological phosphorus removal (EBPR) in activated sludge systems. In this study, the short-term impact (hours) of salinity (as NaCl) was assessed on the aerobic metabolism of a PAO culture, enriched in a sequencing batch reactor (SBR). All aerobic PAO metabolic processes were drastically affected by elevated salinity concentrations. The aerobic maintenance energy requirement increased, when the salinity concentration rose up to a threshold concentration of 2 % salinity (on a W/V basis as NaCl), while above this concentration, the maintenance energy requirements seemed to decrease. All initial rates were affected by salinity, with the NH4- and PO4-uptake rates being the most sensitive. A salinity increase from 0 to 0.18 % caused a 25, 46, and 63 % inhibition of the O2, PO4, and NH4-uptake rates. The stoichiometric ratios of the aerobic conversions confirmed that growth was the process with the highest inhibition, followed by poly-P and glycogen formation. The study indicates that shock loads of 0.18 % salt, which corresponds to the use or intrusion of about 5 % seawater may severely affect the EBPR process already in wastewater treatment plants not exposed regularly to high salinity concentrations. PMID:25524698

  1. Research progrss of competition and control between PAOs and GAOs for different cabon sources%聚磷菌和聚糖菌对碳源竞争及调控的研究进展

    冯翠杰; 王淑梅; 陈少华

    2011-01-01

    Principles for enhanced biological phosphorus removal and metabolism mechanism of polyphosphate accumulating organisms (PAOs) & glycogen accumulating organisms (GAOs) are introduced in this paper. The effects of different carbon sources on competitions between GAOs and PAOs are discussed, and changes of phosphate removal efficiency and the microbial community are analyzed based on the recent researches. Furthermore, some measures are put forward to resolve the problem of PAOs-GAOs competition.%介绍了生物强化除磷原理以及聚磷菌(PAOs)和聚糖菌(GAOs)的代谢机理,阐述了不同碳源对GAOs与PAOs的影响,不同碳源下的除磷效果和微生物群落结构变化,提出了抑制生物强化除磷系统中GAOs竟争的措施.

  2. Comparison of biochemical characteristics between PAO and DPAO sludges.

    Lee, Hansaem; Yun, Zuwhan

    2014-06-01

    A successful enhanced biological phosphorus removal (EBPR) was observed in both anaerobic-aerobic sequencing batch reactor (An-Ox SBR) to induce growth of phosphorus accumulating organism (PAO) and anaerobic-anoxic (An-Ax) SBR to induce growth of denitrifying PAO (DPAO). Although the EBPR performance of An-Ox SBR was higher by 11.3% than that of An-Ax SBR, specific phosphorus release rates in the An-Ax SBR (22.8 ± 3.5 mg P/(g VSS·hr)) and the An-Ox SBR (22.4 ± 4.8 mg P/(g VSS·hr)) were similar. Specific phosphorus uptake rates under anoxic and aerobic conditions were 26.3 ± 4.8 mg P/(g VSS·hr) (An-Ax SBR) and 25.6 ± 2.8 mg P/(g VSS·hr) (An-Ox SBR), respectively, which were also similar. In addition, an analysis of relationship of poly-β-hydroxyalkanoates (PHA) synthesized under anaerobic conditions with phosphorous release (Preleased/PHA synthesized) and of PHA utilized under anoxic and aerobic conditions with phosphorous uptake (Puptaked/PHAutilized) verified that biological activities of EBPR per unit biomass between DPAO and PAO were similar. An analysis of the specific denitrification rate of DPAO showed that NO(-)3-N can be denitrified at a rate that does not substantially differ from that of an ordinary denitrifier without additional consumption of organic carbon when the PHA stored inside the cell under anaerobic conditions is sufficiently secured. PMID:25079846

  3. Elucidating further phylogenetic diversity among the Defluviicoccus-related glycogen-accumulating organisms in activated sludge.

    McIlroy, Simon; Seviour, Robert J

    2009-12-01

    Glycogen-accumulating organisms (GAO) are thought to out-compete the polyphosphate-accumulating organisms (PAO) in activated sludge communities removing phosphate (P). Two GAO groups are currently recognized, the gammaproteobacterial Candidatus'Competibacter phosphatis', and the alphaproteobacterial Defluviicoccus vanus-related tetrad forming organisms (TFOs). Both are phylogenetically diverse based on their 16S rRNA sequences, with the latter currently considered to contain members falling into three distinct clusters. This paper identifies members of an additional fourth Defluviicoccus cluster from 16S rRNA gene clone library data obtained from a laboratory-scale activated sludge plant community removing P, and details FISH probes designed against them. Probe DF181A was designed to target a single sequence and DF181B designed against the remaining sequences in the cluster. Cells hybridizing with these probes in the biomass samples tested always appeared as either TFOs or in large clusters of small cocci. Members of the Defluviicoccus-related organisms were commonly found in full-scale wastewater treatments plants, sometimes as a dominant population. PMID:23765935

  4. Experimental evaluation of decrease in the activities of polyphosphate/glycogen-accumulating organisms due to cell death and activity decay in activated sludge.

    Hao, Xiaodi; Wang, Qilin; Cao, Yali; van Loosdrecht, Mark C M

    2010-06-15

    Decrease in bacterial activity (biomass decay) in activated sludge can result from cell death (reduction in the amount of active bacteria) and activity decay (reduction in the specific activity of active bacteria). The goal of this study was to experimentally differentiate between cell death and activity decay as the cause of decrease in bacterial activity. By means of measuring maximal anaerobic phosphate release rates, verifying membrane integrity by live/dead staining and verifying presence of 16S rRNA with fluorescence in situ hybridization (FISH), the decay rates and death rates of polyphosphate-accumulating organisms (PAOs) in a biological nutrient removal (BNR) system and a laboratory phosphate removing sequencing batch reactor (SBR) system were determined, respectively, under famine conditions. In addition, the decay rate and death rate of glycogen-accumulating organisms (GAOs) in a SBR system with an enrichment culture of GAOs were also measured under famine conditions. Hereto the maximal anaerobic volatile fatty acid uptake rates, live/dead staining, and FISH were used. The experiments revealed that in the BNR and enriched PAO-SBR systems, activity decay contributed 58% and 80% to the decreased activities of PAOs, and that cell death was responsible for 42% and 20% of decreases in their respective activities. In the enriched GAOs system, activity decay constituted a proportion of 74% of the decreased activity of GAOs, and cell death only accounted for 26% of the decrease of their activity. PMID:20178124

  5. Experimental and model-based evaluation of the role of denitrifying polyphosphate accumulating organisms at two large scale WWTPs in northern Poland.

    Makinia, J; Rosenwinkel, K H; Swinarski, M; Dobiegala, E

    2006-01-01

    The capabilities of denitrifying Polyphosphate Accumulating Organisms (DPAOs) in two large-scale plants in northern Poland performing enhanced biological phosphorus removal (EBPR) were evaluated in this study. A series of batch tests with the process biomass aimed at the measurements of phosphate release (with artificial substrate and real wastewater) and subsequent phosphate uptake under anoxic/aerobic conditions. The process kinetics were predicted using ASM2d implemented in the GPS-X ver. 4.0.2 simulation package. The results from one experimental series (summer) were used for the model calibration, whereas the results from another series (spring) were used for the model validation. The model parameters were also accurately confirmed by predictions of the accompanying field measurements in the full-scale bioreactors. The experimental and simulation results revealed that a relatively small fraction of PAO could denitrify (eta(NO3,PAO) = 0.32). The denitrification rates associated with the anoxic storage of PP and the anoxic growth of PAO only constituted 16.0-21.0% of the denitrification rates associated with the anoxic activity of "ordinary" heterotrophs. PMID:17163015

  6. HM-PAO-SPECT in complicated migraine

    Three HM-PAO-SPECT investigations have been performed in a female patient with a complicated migraine. 2.5 hours after an attack with right-sided numbness and atonic hemiparesis, at the left side a reduced blood flow was seen parietotemporally and in the subcortical structures. The cerebellum showed crossed diaschisis. During a symptom-free interval the SPECT showed a slightly increased parietotemporal blood blow and a reduced right temporooccipital blood flow. During a seizure with left-sided facial spasm, unsystematic clonic movements in all extremities and a following left-sided hemiparesis, the uptake in the visual cortex was increased by 60%. In the right frontotemporal and left temporal region a slightly increased accumulation was found. (orig.)

  7. Phosphorus Accumulating Organisms and Biogeochemical Hotspots

    Archibald, J.; Walter, M. T.

    2008-12-01

    Despite extensive research, many of the processes that control phosphorus (P) movement from agricultural fields to streams and lakes are not well understood. This limits our ability to develop management strategies that will mediate P contamination of freshwater ecosystems and subsequent eutrophication. Recent advances in molecular microbiology have prompted a paradigm shift in wastewater treatment that recognizes and exploits the ways specific microbial processes influence P solubility. Central to this enhanced biological phosphorus removal in wastewater treatment plants is a relatively recently discovered microorganism, Candidatus accumulibacter, which takes-up P and stores it internally as polyphosphate under alternating aerobic and anaerobic conditions. Within the past few months we have discovered this organism in the natural environment and its role in P biogeochemistry is unclear. We speculate that it may function similarly in variable source areas, which experience cycles of saturation and desaturation, as it does in the anaerobic- aerobic cycles in a wastewater treatment plant. If so, there may be potential opportunities to realize similarly new perspectives and advancements in the watershed context as have been seen in wastewater technologies. Here we present some of our preliminary findings.

  8. Accumulation of organic C components in soil and aggregates

    Yu, Hongyan; Ding, Weixin; Chen, Zengming; Zhang, Huanjun; Luo, Jiafa; Bolan, Nanthi

    2015-09-01

    To explore soil organic carbon (SOC) accumulation mechanisms, the dynamics of C functional groups and macroaggregation were studied synchronously through aggregate fractionation and 13C NMR spectroscopy in sandy loam soil following an 18-year application of compost and fertilizer in China. Compared with no fertilizer control, both compost and fertilizer improved SOC content, while the application of compost increased macroaggregation. Fertilizer application mainly increased the levels of recalcitrant organic C components characterized by methoxyl/N-alkyl C and alkyl C, whereas compost application mainly promoted the accumulation of methoxyl/N-alkyl C, phenolic C, carboxyl C, O-alkyl C and di-O-alkyl C in bulk soil. The preferential accumulation of organic C functional groups in aggregates depended on aggregate size rather than nutrient amendments. These groups were characterized by phenolic C and di-O-alkyl C in the silt + clay fraction, carboxyl C in microaggregates and phenolic C, carboxyl C and methoxyl/N-alkyl C in macroaggregates. Thus, the differences in accumulated organic C components in compost- and fertilizer-amended soils were primarily attributable to macroaggregation. The accumulation of methoxyl/N-alkyl C in microaggregates effectively promoted macroaggregation. Our results suggest that organic amendment rich in methoxyl/N-alkyl C effectively improved SOC content and accelerated macroaggregation in the test soil.

  9. Dynamics of Intracellular Polymers in Enhanced Biological Phosphorus Removal Processes under Different Organic Carbon Concentrations

    Lizhen Xing; Li Ren; Bo Tang,; Guangxue Wu; Yuntao Guan

    2013-01-01

    Enhanced biological phosphorus removal (EBPR) may deteriorate or fail during low organic carbon loading periods. Polyphosphate accumulating organisms (PAOs) in EBPR were acclimated under both high and low organic carbon conditions, and then dynamics of polymers in typical cycles, anaerobic conditions with excess organic carbons, and endogenous respiration conditions were examined. After long-term acclimation, it was found that organic loading rates did not affect the yield of PAOs and the app...

  10. Accumulation and distribution 137Сs in predators’ organism

    A. V. Gulakov

    2007-10-01

    Full Text Available Data of the long-term research of accumulation and distribution 137Cs radionuclide in organisms of predatory wild animals from the alienation zone of the Chernobyl nuclear power station are presented. Essential fluctuations of the 137Cs contents in muscular tissue are noted. The results have large practical value for management of the hunting facilities on the radioactively polluted territories.

  11. Denitrifying capability and community dynamics of glycogen accumulating organisms during sludge granulation in an anaerobic-aerobic sequencing batch reactor

    Bin, Zhang; Bin, Xue; Zhigang, Qiu; Zhiqiang, Chen; Junwen, Li; Taishi, Gong; Wenci, Zou; Jingfeng, Wang

    2015-08-01

    Denitrifying capability of glycogen accumulating organisms (GAOs) has received great attention in environmental science and microbial ecology. Combining this ability with granule processes would be an interesting attempt. Here, a laboratory-scale sequencing batch reactor (SBR) was operated to enrich GAOs and enable sludge granulation. The results showed that the GAO granules were cultivated successfully and the granules had denitrifying capability. The batch experiments demonstrated that all NO3--N could be removed or reduced, some amount of NO2--N were accumulated in the reactor, and N2 was the main gaseous product. SEM analysis suggested that the granules were tightly packed with a large amount of tetrad-forming organisms (TFOs); filamentous bacteria served as the supporting structures for the granules. The microbial community structure of GAO granules was differed substantially from the inoculant conventional activated sludge. Most of the bacteria in the seed sludge grouped with members of Proteobacterium. FISH analysis confirmed that GAOs were the predominant members in the granules and were distributed evenly throughout the granular space. In contrast, PAOs were severely inhibited. Overall, cultivation of the GAO granules and utilizing their denitrifying capability can provide us with a new approach of nitrogen removal and saving more energy.

  12. Accumulation and excretion of 60Co by marine organisms

    The biological half-life of 60Co accumulated from seawater by marine fish was 20-50 days. It was slightly longer in the liver and muscles than in the whole body. Feed including natural feed organisms contributed more to the total body burden of 60Co than environmental waters. The total body burden of 60Co via feed varied according to the organism species, kinds of feed and the root of incorporation. Transfer ratio of 60Co from the water into the organisms was higher than that from the marine sediments having high affinity of Co into the organisms. The elevated water temperature promoted the biological activity, resulting in the increased bioaccumulation of radioactive Co. Concentration coefficients of 60Co by mollusca and seaweeds were generally high. In particular, organic 60Co was more likely to be accumulated than inorganic 60Co. The biological half-life of organic 60Co was longer than inorganic 60Co in mollusca, while it was the same as or shorter than inorganic 60Co in the other organisms. (Namekawa, K.)

  13. Study on accumulation of 137Cs in aquatic organisms

    FengDing-Hua; CheungT

    1998-01-01

    The organisms were cultivated for 7d in well water contaminated with 137Cs,The experimental results show that the accumulation level of tissues of carassius auratus had the order of gill>viscera>epidermis(including scales)>bone(including head and tail)>flesh.The concentration capability of them had the order of shrimp>carassius auratus>ophiocephalus argus,The concentration factors(CF) of shrimp was 12.6 times of that of ophiocephalus argus.

  14. Organic Illness and Psychic Puberty: An Accumulation of Trauma.

    de Kernier, Nathalie

    2015-08-01

    When an adolescent faces serious organic illness, two traumatic events coincide and reinforce each other. The Oedipus fantasy and its murderous component are exacerbated. Starting psychotherapy in these circumstances is a challenge. Teens suffering from serious organic illness rarely request psychological help. They accumulate aggressive impulses that remain unspoken but are self-directed. We will use excerpts from cases to comment upon the problems and psychical processes experienced by such teens. We will show how expressing murder fantasies can be a motor in psychotherapy. Such expression not only supports therapy but also relieves the patient and contributes to a new psychosomatic equilibrium. PMID:26290946

  15. Extreme accumulations of natural polonium-210 in certain marine organisms

    Concentration levels of polonium-210 reported for sea water are reviewed, and activities accumulated by various marine plant and animal species are discussed. Special mention is made of detailed studies of one giant algae upon whose outer surfaces intense accumulations of polonium have been discovered recently. Some concentrations found in two organisms intimate with algae, the abalones and the sea hares, are reported. Concentrations are listed pertaining to organisms selected from the open ocean in order to show that intense polonium concentrations are not restricted to organisms living near the continents where precursors of polonium originate. A brief discussion of conditions on one of the marine mammals, the dolphin, next is made. Then comments are made upon a benthic species (the sable fish) that prefers to live close to the deep sea floor, presumably so as to eat detritus. They also eat many of the smaller organisms that compete for the natural deep sea fallout of food, and many of these live in close contact with the muds and clays of the sea floor that are rich in radium. Some of the behavior and anatomical features and polonium-210 distribution in one of the most interesting and valuable of fishes, the North Pacific albacore (Thunnus alalunga) is described. This species has been used previously to tell us something about nuclear fallout distributions in the North Pacific Ocean during the past decade and repeatedly has directed attention to features of this ocean that might hardly be detected otherwise. (U.S.)

  16. Retention mechanism of technetium-99m-HM-PAO: intracellular reaction with glutathione

    Preparations of d,l- and meso-hexamethylpropyleneamine oxime (HM-PAO) labeled with technetium-99m were added to rat brain homogenates diluted with phosphate buffer (1:10). The conversion of d,l-HM-PAO to hydrophilic forms took place with an initial rate constant of 0.12 min-1. Incubation of the brain homogenate with 2% diethyl maleate for 5 h decreased the homogenate's measured glutathione (GSH) concentration from 160 to 16 microM and decreased the conversion rate to 0.012 min-1. Buffered aqueous solutions of glutathione rapidly converted the HM-PAO tracers to hydrophilic forms having the same chromatographic characteristics as found in the brain homogenates. The rate constant for the conversion reaction of d,l-HM-PAO in GSH aqueous solution was 208 and 317 L/mol/min in two different assay systems and for meso-HM-PAO the values were 14.7 and 23.2 L/mol/min, respectively. Rat brain has a GSH concentration of about 2.3 mM and the conversion of the d,l-HM-PAO due to GSH alone should proceed with a rate constant of 0.48 to 0.73 min-1 and be correspondingly 14-fold slower for meso-HM-PAO. In human brain, the in vivo data of Lassen et al. show a conversion rate constant of 0.80 min-1. This correspondence of values supports the notion that GSH may be important for the in vivo conversion of 99mTc-labeled HM-PAO to hydrophilic forms and may be the mechanism of trapping in brain and other cells. A kinetic model for the trapping of d,l- and meso-HM-PAO in tissue is developed that is based on data of GSH concentration in various organs

  17. Dynamics of Intracellular Polymers in Enhanced Biological Phosphorus Removal Processes under Different Organic Carbon Concentrations

    Lizhen Xing

    2013-01-01

    Full Text Available Enhanced biological phosphorus removal (EBPR may deteriorate or fail during low organic carbon loading periods. Polyphosphate accumulating organisms (PAOs in EBPR were acclimated under both high and low organic carbon conditions, and then dynamics of polymers in typical cycles, anaerobic conditions with excess organic carbons, and endogenous respiration conditions were examined. After long-term acclimation, it was found that organic loading rates did not affect the yield of PAOs and the applied low organic carbon concentrations were advantageous for the enrichment of PAOs. A low influent organic carbon concentration induced a high production of extracellular carbohydrate. During both anaerobic and aerobic endogenous respirations, when glycogen decreased to around 80 ± 10 mg C per gram of volatile suspended solids, PAOs began to utilize polyphosphate significantly. Regressed by the first-order reaction model, glycogen possessed the highest degradation rate and then was followed by polyphosphate, while biomass decay had the lowest degradation rate.

  18. Characterization of the denitrifying fraction of phosphate accumulating organisms in biological phosphate removal

    Meinhold, Jens; Filipe, Carlos D.M.; Daigger, Glen T.;

    1999-01-01

    Results of experimental investigations are presented that strongly support the hypothesis that PAO from activated sludge systems consist of two groups: a) denitrifying PAO (DNPAO) capable of using oxygen and nitrate and b) non-denitrifying PAO (non-DNPAO) only able to use oxygen. Batch experiment...

  19. 生物除磷系统中聚磷菌检测常用技术%Commonly Used Technologies for Detecting Phosphate Accumulating Organisms in Biological Phosphorus Removal System

    潘丹华; 李勇; 张娜

    2013-01-01

    As the main functional bacteria in biological phosphorus removal system, it was an inevitable trend to have a qualitative and quantitative analysis for phosphate accumulating organisms (PAOs) in order to deeply understand the biological phosphorus removal system and improve phosphorus removal efficiency. Mainly used methods for detecting PAOs include chemical and molecular biological technologies. Characteristics and applications of technologies such as fluorescence in situ hybridization(FISH), polymerase chain reaction (PCR), degeneration gradient electrophoresis (DGGE) and combined technologies used in detecting PAOs were reviewed. Some improvement measures and future direction for PAOs detecting technologies were also offered.%作为生物除磷系统中的主要功能菌,对聚磷菌菌群进行定性、定量分析是深入理解生物除磷系统、提高除磷效率的必然趋势.目前常用于检测聚磷菌的方法主要有生物化学法和分子生物学法,文章主要阐述了荧光原位杂交技术、聚合酶链反应技术、变性梯度凝胶电泳技术以及多技术结合使用的特点及应用情况,并在此基础上提出了改进措施以及聚磷菌检测技术的发展方向.

  20. Higher lung accumulation of intravenously injected organic nanotubes

    Maitani Y

    2013-01-01

    Full Text Available Yoshie Maitani,1 Yuri Nakamura,1 Masao Kon,1 Emi Sanada,1 Kae Sumiyoshi,1 Natsuki Fujine,1 Masumi Asakawa,2 Masaki Kogiso,2 Toshimi Shimizu21Institute of Medicinal Chemistry, Hoshi University, Tokyo, Japan; 2Nanotube Research Center (NTRC, National Institute of Advanced Industrial Science and Technology (AIST, Tsukuba, JapanAbstract: The size and shape of intravenously injected particles can affect their biodistribution and is of importance for the development of particulated drug carrier systems. In this study, organic nanotubes (ONTs with a carboxyl group at the surface, a length of approximately 2 µm and outer diameter of 70–90 nm, were injected intravenously into tumor-bearing mice. To use ONTs as drug carriers, the biodistribution in selected organs of ONTs postinjection was examined using irinotecan, as an entrapped water-soluble marker inside ONTs, and gadolinium-chelated ONT, as an ONT marker, and compared with that of a 3 µm fluorescently labeled spherical microparticle which was similar size to the length of ONTs. It was found that for irinotecan, its active metabolite and gadolinium-chelated ONTs were highly accumulated in the lung, but to a lower level in the liver and spleen. On the other hand, microparticles deposited less in the lung and more highly in the liver. Moreover, histologic examination showed ONTs distributed more in lung tissues in part, whereas microparticles were present in blood vessels postinjection. These preliminary results support the notion of using negatively charged ONTs as intravascular carriers to maximize accumulation in the lung whilst reducing sequestration by the liver and spleen. This finding suggested that ONTs are potential carriers for lung-targeting drug delivery.Keywords: organic nanotube, lung, biodistribution, microparticle, particle shape

  1. Accumulation of motile elongated micro-organisms in turbulence

    Zhan, Caijuan; Sardina, Gaetano; Lushi, Enkeleida; Brandt, Luca

    2014-01-01

    We study the effect of turbulence on marine life by performing numerical simulations of motile microorganisms, modelled as prolate spheroids, in isotropic homogeneous turbulence. We show that the clustering and patchiness observed in laminar flows, linear shear and vortex flows, are significantly reduced in a three-dimensional turbulent flow mainly because of the complex topology; elongated micro-orgamisms show some level of clustering in the case of swimmers without any preferential alignment whereas spherical swimmers remain uniformly distributed. Micro-organisms with one preferential swimming direction (e.g. gyrotaxis) still show significant clustering if spherical in shape, whereas prolate swimmers remain more uniformly distributed. Due to their large sensitivity to the local shear, these elongated swimmers react slower to the action of vorticity and gravity and therefore do not have time to accumulate in a turbulent flow. These results show how purely hydrodynamic effects can alter the ecology of microorganisms that can vary their shape and their preferential orientation.

  2. Accumulation of motile elongated micro-organisms in turbulence

    Zhan, Caijuan; Lushi, Enkeleida; Brandt, Luca

    2013-01-01

    We study the effect of turbulence on marine life by performing numerical simulations of motile microorganisms, modelled as prolate spheroids, in isotropic homogeneous turbulence. We show that the clustering and patchiness observed in laminar flows, linear shear and vortex flows, are significantly reduced in a three-dimensional turbulent flow mainly because of the complex topology; elongated micro-orgamisms show some level of clustering in the case of swimmers without any preferential alignment whereas spherical swimmers remain uniformly distributed. Micro-organisms with one preferential swimming direction (e.g. gyrotaxis) still show significant clustering if spherical in shape, whereas prolate swimmers remain more uniformly distributed. Due to their large sensitivity to the local shear, these elongated swimmers react slower to the action of vorticity and gravity and therefore do not have time to accumulate in a turbulent flow. These results show how purely hydrodynamic effects can alter the ecology of microor...

  3. Organization and transcription of the principal sigma gene (rpoDA) of Pseudomonas aeruginosa PAO1: involvement of a sigma 32-like RNA polymerase in rpoDA gene expression.

    Fujita, M.; Tanaka, K; Takahashi, H; Amemura, A

    1993-01-01

    S1 nuclease mapping and Northern (RNA) hybridization revealed that the rpoDA gene encoding the principal sigma subunit of Pseudomonas aeruginosa PAO1 is transcribed as a monocistronic mRNA of 2 kb and that the transcription from the rpoDA promoter (PC) starts 32 bases upstream from the first nucleotide of the initiation codon during the steady-state growth condition at a low temperature (30 degrees C). The transcript terminates 31 bases downstream from the last nucleotide of the termination c...

  4. ACCUMULATION OF POLYCHLORINATED BIPHENYLS IN AQUATIC ORGANISMS AND ENVIRONMENT

    ÇAKIROĞULLARI, Gül

    2010-01-01

    Polychlorinated biphenyls (PCBs) were discovered in the late of the 19th century and their usefulness for industry, because of their physical properties, was recognized early. The PCBs have been used commercially, since 1930, as dielectric and heat-exchange fluids and in a variety of other applications. They have become widely distributed in the environment throughout the world, and are persistent and accumulate in food webs. PCBs accumulate in the fatty tissues of humans and other animals an...

  5. Quinolone accumulation in Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus.

    McCaffrey, C; Bertasso, A; Pace, J.; Georgopapadakou, N H

    1992-01-01

    The accumulation of quinolones by Escherichia coli JF568, Pseudomonas aeruginosa PAO1, and Staphylococcus aureus ATCC 29213 was measured by a modified fluorometric assay (J. S. Chapman and N. H. Georgopapadakou, Antimicrob. Agents Chemother. 33:27-29, 1989). The quinolones examined were fleroxacin, pefloxacin, norfloxacin, difloxacin, A56620, ciprofloxacin, ofloxacin, and Ro 09-1168. In all three organisms, uptake was complete in less than 5 min and was proportional to extracellular quinolone...

  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. Accumulation of trace metals in coastal marine organisms

    ECN at Petten carries out a survey on the occurrence of trace metals in coastal marine organisms. The survey is aimed to provide an estimate of concentration factors in local marine organisms for neutron activation products released as low-level liquid radioactive waste into the North Sea. The organisms studied are red and brown seaweed, edible mussels ans shrimp. A summary of the results of analyses of iron, cobalt, zinc, silver and antimony in these organisms is presented. Concentration factors derived from mean stable-element concentrations range from about 50 for Sb in red seaweed and shrimp to about 104 for Fe in red seaweed and mussels. The largest variation is shown for zinc in seaweed, which variation is seasonal and most pronounced in brown seaweed. A discussion of the data is presented in relation to data from other West-European coastal areas and to data used for the radiological assessment of deep sea disposal of radioactive waste

  8. Transference and accumulative peculiarity of enriched uranium in organism

    Studies show that 235UO2F2 was chiefly localized in kidneys, then in skeleton and liver. Its radioactivity in skeleton rose steadily while the concentration in kidneys and liver dropped. 235UO2F2 was difficult to pass through the blood-testes barrier. With 1 to 6 h contact period, only 1.4-1.6% 235UO2F2 was found in the intact skin, but 41-54% in the abrasive skin. The dynamic retention of 235UO2F2 through intact or abrasive skins was also dominantly localized in kidneys, skeleton and liver. Accumulation of insoluble 235U3O8 in gastrointestinal tract was well described by a double-exponential-term expression. Values of retention were estimated for fast component T1 = 0.34 d, and for relatively long term component T2 = 4.05 d

  9. 99mTc-HM-PAO SPECT of epileptic patients showing focal paroxysm on electroencephalography

    The usefulness of 99mTc-HM-PAO SPECT in diagnosing epilepsy was studied. The subjects were 33 epileptic patients, ranging in age from 5 years and 5 months to 28 years and 3 months, who showed focal paroxysm on electroencephalograms. Lowered accumulation site was found on SPECT in 19 patients. Four patients with abnormal findings on X-ray CT or MRI showed lowered accumulation and focal paroxysm at the same site. Of 29 patients with normal X-ray CT or MRI findings, 15 (52%) showed lowered accumulation. Five patients showed a focal paroxysm at the site of lowered accumulation. In 8 patients the focal paroxysm site was partly coincided with the accumulation site. In some patients the focal site predicted by the findings of clinical symptoms and the lowered accumulation site coincided. SPECT is therefore a useful method in diagnosing a focal site in epilepsy and considered to reflect the severity of disease. (Y.S.)

  10. Determining Multiple Responses of Pseudomonas aeruginosa PAO1 to an Antimicrobial Agent, Free Nitrous Acid.

    Gao, Shu-Hong; Fan, Lu; Peng, Lai; Guo, Jianhua; Agulló-Barceló, Míriam; Yuan, Zhiguo; Bond, Philip L

    2016-05-17

    Free nitrous acid (FNA) has recently been demonstrated as an antimicrobial agent on a range of micro-organisms, especially in wastewater-treatment systems. However, the antimicrobial mechanism of FNA is largely unknown. Here, we report that the antimicrobial effects of FNA are multitargeted. The response of a model denitrifier, Pseudomnas aeruginosa PAO1 (PAO1), common in wastewater treatment, was investigated in the absence and presence of inhibitory level of FNA (0.1 mg N/L) under anaerobic denitrifying conditions. This was achieved through coupling gene expression analysis, by RNA sequencing, and with a suite of physiological analyses. Various transcripts exhibited significant changes in abundance in the presence of FNA. Respiration was likely inhibited because denitrification activity was severely depleted, and decreased transcript levels of most denitrification genes occurred. As a consequence, the tricarboxylic acid (TCA) cycle was inhibited due to the lowered cellular redox state in the FNA-exposed cultures. Meanwhile, during FNA exposure, PAO1 rerouted its carbon metabolic pathway from the TCA cycle to pyruvate fermentation with acetate as the end product as a possible survival mechanism. Additionally, protein synthesis was significantly decreased, and ribosome preservation was evident. These findings improve our understanding of PAO1 in response to FNA and contribute toward the potential application for use of FNA as an antimicrobial agent. PMID:27116299

  11. Accumulation of persistent organic pollutants in Tasmanian platypus (Ornithorhynchus anatinus)

    Munday, B.L.; Stewart, N.J.; Soedergren, A

    2002-12-01

    Elevated levels of persistent organic pollutants were found in both male and female platypus in Tasmania. - Tailfat samples were collected from 56 platypuses, 38 male and 18 female in Tasmania. No statistically significant, nor apparent, differences between the sexes were found for tailfat lipid levels and DDT and its metabolites, Lindane and PCB concentrations in tailfat lipid. Apparently - but not statistically - significantly different levels of DDT and its metabolites, Lindane and PCB concentrations were found in animals from different geographic regions of the State. Higher concentrations of DDT and its metabolites and Lindane were related to the intensity of agricultural activity and elevated PCB levels were mainly found in animals from zones with industrial and hydroelectric developments.

  12. Accumulation of persistent organic pollutants in Tasmanian platypus (Ornithorhynchus anatinus)

    Elevated levels of persistent organic pollutants were found in both male and female platypus in Tasmania. - Tailfat samples were collected from 56 platypuses, 38 male and 18 female in Tasmania. No statistically significant, nor apparent, differences between the sexes were found for tailfat lipid levels and DDT and its metabolites, Lindane and PCB concentrations in tailfat lipid. Apparently - but not statistically - significantly different levels of DDT and its metabolites, Lindane and PCB concentrations were found in animals from different geographic regions of the State. Higher concentrations of DDT and its metabolites and Lindane were related to the intensity of agricultural activity and elevated PCB levels were mainly found in animals from zones with industrial and hydroelectric developments

  13. Organ- and species-specific accumulation of metals in two land snail species (Gastropoda, Pulmonata)

    In order to evaluate the usefulness of terrestrial gastropods as bioindicators there is a need for studies that simultaneously compare (1) concentrations of metals in reference and polluted plots, (2) species within the same polluted habitat, (3) metal accumulation patterns in different organs and (4) metal accumulation patterns in relation to soil physicochemical properties. This study aims to assess metal accumulation patterns in two land snail species. Instead of analyzing an organism as a whole, investigating the partitioning of metals in different organs can provide information on the actual toxicological relevant fractions. Therefore, concentrations of Ag, Cd, Cr, Cu, Ni and Zn were examined in five different organs of Cepaea nemoralis, as well as in the foot and the body of Succinea putris. Snails were sampled at four polluted dredged sediment disposal localities and three adjacent less polluted reference plots situated along waterways in Flanders, Belgium. Due to the small size and problematic dissection of S. putris only the concentrations in the foot of both species could be compared. For this reason only, C. nemoralis can be described as a better bioindicator species that allows a far more detailed analysis of organ metal accumulation. This study showed that organs other than the digestive gland may be involved in the immobilization and detoxification of metals. Furthermore, pH, soil fractionation (clay %, silt %, sand %) and organic matter, correlate with metal accumulation in organs. However, most often the soil metal concentrations did not correlate with the concentrations found in snail organs. Metal concentrations in organs of both species (1) differed among polluted plots but rarely between polluted and reference plots within a locality, (2) were organ-specific (digestive gland > foot > albumen gland = spermoviduct = ovotestis), (3) were species-specific and (4) depended on the metal type (high Cd and Cu concentrations were observed in the

  14. Organic Carbon Accumulation in Topsoil Following Afforestation with Willow: Emphasis on Leaf Litter Decomposition and Soil Organic Matter Quality

    Benoit Lafleur

    2015-03-01

    Full Text Available Short-rotation intensive cultures (SRICs of willows can potentially sequester carbon (C in soil. However, there is limited information regarding the factors governing soil organic C (Corg accumulation following afforestation. The objectives of this study were to: (i determine whether willow leads to Corg accumulation in the topsoil (0–10 cm two to six years after establishment in five SRICs located along a large climatic/productivity gradient in southern Quebec, and (ii assess the influence of leaf litter decomposition and soil organic matter (OM quality on Corg accumulation in the topsoil. Topsoil Corg concentrations and pools under SRICs were, on average, 25% greater than reference fields, and alkyls concentrations were higher under SRICs. On an annualized basis, Corg accumulation rates in the topsoil varied between 0.4 and 4.5 Mg ha−1 yr−1. Estimated annual litterfall C fluxes were in the same order of magnitude, suggesting that SRICs can accumulate Corg in the topsoil during early years due to high growth rates. Leaf litter decomposition was also related to Corg accumulation rates in the topsoil. It was positively correlated to growing season length, degree-days, and growing season average air and topsoil temperature (r > 0.70, and negatively correlated to topsoil volumetric water content (r = −0.55. Leaf litter decomposition likely occurred more quickly than that of plants in reference fields, and as it progressed, OM became more decay resistant, more stable and accumulated as Corg in the topsoil.

  15. Accumulation of tritium in aquatic organisms through a food chain with three trophic levels

    Accumulation of tritium in aquatic organisms was estimated through a model food chain such as; tritiated water (THO) → diatoms → brine shrimps → Japanese killifish. Tritium accumulations in each organism as organic bound form are expressed as the R value which is defined as the ratio of tritium specific activity in lyophilized organisms (μCi/gH) to that in water (μCi/gH). The maximum R values were 0.5 in diatoms, Chaetoceros gracilis, 0.5 in brine shrimps, Artamia salina, and 0.32 in Japanese killifish, Oryzias latipes under the growing condition where tritium accumulation took place from tritiated water without tritiated diets. Brine shrimps and Japanese killifish, which grew from larvae to adult in tritiated sea water with feeding on tritiated diets (model food chain), had the R value at 0.70 and 0.67 respectively, indicating that more tritium accumulation in consumer populations with tritiated diets than those without tritiated diets. In addition, the R values of each organ of Japanese killifish, of DNA and the nucleotides purified from brine shrimps growing under the condition with or without our model food chain were measured to estimate the tritium distribution in the body or various components of the organism. These results did not indicate the seeking characteristic of tritium to some specific organs of compounds. (author)

  16. Macronutrient composition determines accumulation of persistent organic pollutants from dietary exposure in adipose tissue of mice

    Myrmel, Lene Secher; Fjære, Even; Midtbø, Lisa Kolden;

    2016-01-01

    Accumulation of persistent organic pollutants (POPs) has been linked to adipose tissue expansion. As different nutrients modulate adipose tissue development, we investigated the influence of dietary composition on POP accumulation, obesity development and related disorders. Lifespan was determined...... in mice fed fish-oil-based high fat diets during a long-term feeding trial and accumulation of POPs was measured after 3, 6 and 18months of feeding. Further, we performed dose-response experiments using four abundant POPs found in marine sources, PCB-153, PCB-138, PCB-118 and pp'-DDE as single...

  17. Accumulation of different metals in apple trees organs from an unfertilized orchard

    Working in an unfertilized apple orchard, planted on brown-reddish soil in Baneasa - Bucuresti, the accumulation of different metals in trees organs was studied: leaves, vegetative branches, fruit branches and fruits. The samples were taken from 'Golden delicious' variety, planted at 10 meters, 'Idared' variety, planted at 100 meters and 'Akane' variety, planted at 200 meters from the Bucuresti-Ploiesti motorway. Lead accumulation depended on the distance to the pollution source and organ type. In leaves, lead was found even at 100 m from the road border (11.7 ppm in 'Idared' variety). At 10 m the leaves content was much higher (306 ppm, 'Golden delicious'). Because of the specific metabolism selectivity apple trees didn't accumulate lead into fruit branches and fruits. Copper leaves content varied between 5.85 ppm ('Golden delicious') and 16.2 ppm ('Akane') being lower than the fruits content (8.36 ppm 'Idared' - 23.0 ppm 'Golden delicious'). In apple tree fruit branches the Cu accumulation was 2-3 times higher than in the vegetative branches. The same fruit branches accumulated the highest quantity of zinc (between 67.5 and 83.9 ppm). Fruit contents in zinc (10.0-16.9 ppm) were close to the normal value: 15 ppm, but leave contents (43.3-48.7 ppm) were more than doubled compared to the normal range: 15-20 ppm. The 'Idared' variety accumulated the lowest quantity of nickel in all analyzed organs. Iron accumulation was different in function of the analyzed organ, variety and ion type (Fe2+, Fe3+). The highest Fe3+ content was found in 'Golden delicious' leaves: 547 ppm and the highest Fe2+ content in 'Idared' leaves: 96.0 ppm. The lowest iron content was found in fruits. The manganese content of the analyzed organs varied from 8.32 to 130 ppm. Refs. 4 (author)

  18. The retention mechanism of technetium-99m-HM-PAO

    Neirinckx, R D; Burke, J F; Harrison, R C; Forster, A M; Andersen, A R; Lassen, N A

    1988-01-01

    Preparations of d,l- and meso-hexamethylpropyleneamine oxime (HM-PAO) labeled with technetium-99m were added to rat brain homogenates diluted with phosphate buffer (1:10). The conversion of d,l-HM-PAO to hydrophilic forms took place with an initial rate constant of 0.12 min-1. Incubation of the...... chromatographic characteristics as found in the brain homogenates. The rate constant for the conversion reaction of d,l-HM-PAO in GSH aqueous solution was 208 and 317 L/mol/min in two different assay systems and for meso-HM-PAO the values were 14.7 and 23.2 L/mol/min, respectively. Rat brain has a GSH...... correspondence of values supports the notion that GSH may be important for the in vivo conversion of 99mTc-labeled HM-PAO to hydrophilic forms and may be the mechanism of trapping in brain and other cells. A kinetic model for the trapping of d,l- and meso-HM-PAO in tissue is developed that is based on data of...

  19. Experimental evidence of a xylose-catabolic pathway on the pAO1 megaplasmid of Arthrobacter nicotinovorans

    Marius Mihasan

    2012-09-01

    Full Text Available The pAO1 megaplasmid of A. nicotinovorans consists of 165 ORF's related mainly to nicotine degradation, uptake and utilization of carbohydrates, amino acids and sarcosine. A putative sugar catabolic pathway consisting of 11 ORF's organized as a single operon were previously described. The current work brings experimental data supporting the existence of a D-Xylose catabolic pathway on the pAO1 megaplasmid. When grown on D-xylose containing media, the cells harboring the pAO1 megaplasmid grow to higher cell densities and also express the OxRe protein coded by the megaplasmid. A putative pathway similar to Weimberg pentose pathway is postulated, in which D-xylose is transported in the cell by the ABC-type transport system and then transformed using the putative sugar-dehidrogenase OxRe to D-xylonate, which is further degrated to 2-ketoglutarate and integrated into the general metabolism of the cell

  20. Protective Effect of Melatonin on Aluminum Accumulation in Some Organs of Rats

    Florin MUSELIN

    2015-01-01

    Full Text Available This study emphasizes the protective effect of melatonin against the aluminum accumulation in some organs of rats. Twenty eight male Wistar rats were divided into four groups (n=7 animals for each, one control and three experimental, and aluminum sulphate and melatonin were applied in drinking water for three months as follows: group I: aluminum sulphate (1000 ppb in water, group II: aluminum sulphate (1000 ppb in water and melatonin (10 mg in 100 mL water and group III: melatonin (10 mg in100 mL water. Control group: water. Aluminum was accumulated in liver, kidney, heart, spleen and brain of exposed rats in significantly higher amounts compared to the control group. The findings showed that melatonin administration reduced the aluminum level in studied organs and melatonin had a protective effect against aluminum accumulation.

  1. High accumulation of cobalt-60 by the particular organ or part of some species in mollusca

    A large amounts of samples in marine Cephalopoda and Tridacna were sampled in north west pacific ocean, near Japan. The samples were separated into organs or parts for determination of Co-60 concentration. A peculiar accumulation of Co-60 by the branchial heart of Octopus was also recognized in field condition, but it had become apparent that branchial heart of squid had not same ability. Liver of Cephalopoda had the ability to highly accumulate the Co-60 and specific activity of squid was one order highter than Octopus. The concentration of Cobalt-60 in visceral muss kidney of Tridacna maxima lineally increased with increasing shell length but that in other soft parts was kept constant. After examination of the other papers it was assumed that Co-60 highly accumulated in these organs was transfered by the food chain. (author)

  2. Global metabolic profiling of Arabidopsis Polyamine Oxidase 4 (AtPAO4 loss-of-function mutants exhibiting delayed dark-induced senescence

    Miren Iranzu Sequera-Mutiozabal

    2016-02-01

    Full Text Available Early and more recent studies have suggested that some polyamines (PAs, and particularly spermine (Spm, exhibit anti-senescence properties in plants. In this work, we have investigated the role of Arabidopsis Polyamine Oxidase 4 (PAO4, encoding a PA back-conversion oxidase, during dark-induced senescence. Two independent PAO4 (pao4-1 and pao4-2 loss-of-function mutants have been found that accumulate 10-fold higher Spm, and this associated with delayed entry into senescence under dark conditions. Mechanisms underlying pao4 delayed senescence have been studied using global metabolic profiling by GC-TOF/MS. pao4 mutants exhibit constitutively higher levels of important metabolites involved in redox regulation, central metabolism and signaling that support a priming status against oxidative stress. During senescence, interactions between PAs and oxidative, sugar and nitrogen metabolism have been detected that additively contribute to delayed entry into senescence. Our results indicate the occurrence of metabolic interactions between PAs, particularly Spm, with cell oxidative balance and transport/biosynthesis of amino acids as a strategy to cope with oxidative damage produced during senescence.

  3. The effect of soil macrofauna on organic matter accumulation and soil formation in post mining landscape

    Frouz, Jan

    Cottbus : Brandenburg University of Technology Cottbus, 2002. s. 53. [International Conference - Disturbed Landscapes. 24.09.2002-27.09.2002, Cottbus] Institutional research plan: CEZ:AV0Z6066911 Keywords : soil macrofauna * organic matter accumulation * post mining landscape Subject RIV: EH - Ecology, Behaviour

  4. Organic carbon accumulation capability of two typical tidal wetland soils in Chongming Dongtan, China.

    Zhang, Shiping; Wang, Lei; Hu, Jiajun; Zhang, Wenquan; Fu, Xiaohua; Le, Yiquan; Jin, Fangming

    2011-01-01

    We measured organic carbon input and content of soil in two wetland areas of Chongming Dongtan (Yangtze River Estuary) to evaluate variability in organic carbon accumulation capability in different wetland soils. Observed differences were investigated based on the microbial activity and environmental factors of the soil at the two sites. Results showed that the organic carbon content of wetland soil vegetated with Phragmites australis (site A) was markedly lower than that with P. australis and Spartina alterniflora (site B). Sites differences were due to higher microbial activity at site A, which led to higher soil respiration intensity and greater carbon outputs. This indicated that the capability of organic carbon accumulation of the site B soils was greater than at site A. In addition, petroleum pollution and soil salinity were different in the two wetland soils. After bio-remediation, the soil petroleum pollution at site B was reduced to a similar level of site A. However, the culturable microbial biomass and enzyme activity in the remediated soils were also lower than at site A. These results indicated that greater petroleum pollution at site B did not markedly inhibit soil microbial activity. Therefore, differences in vegetation type and soil salinity were the primary factors responsible for the variation in microbial activity, organic carbon output and organic carbon accumulation capability between site A and site B. PMID:21476345

  5. 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

  6. Cell aggregation of Pseudomonas aeruginosa strain PAO1 as an energy-dependent stress response during growth sodium dodecyl sulfate

    Klebensberger, Janosch; Rui, Oliver; Fritz, Eva; Schink, Bernhard; Philipp, Bodo

    2006-01-01

    Pseudomonas aeruginosa strain PAO1 grew with the detergent sodium dodecyl sulfate (SDS). The growth started with the formation of macroscopic cell aggregates which consisted of respiring cells embedded in an extracellular matrix composed of acidic polysaccharides and DNA. Damaged and uncultivable cells accumulated in these aggregates compared to those cells that remained suspended. We investigated the response of suspended cells to SDS under different conditions. At high energy supply, the ce...

  7. Organic Carbon, Nitrogen and Phosphorus Accumulation Rates in the Soils of the Everglades Mangrove Ecotone

    Smoak, J. M.; Breithaupt, J. L.; Sanders, C. J.

    2015-12-01

    One of the fundamental questions with regard to coastal ecotones relates to their role in the transformation, transport and storage of biogeochemically important constituents and how that role may be altered by climate change. Coastal wetlands provide a range of valuable ecosystem services including sequestering organic carbon (OC) and nutrients in their soils at rates greater than terrestrial ecosystems on a per area basis. As such the Everglades mangrove ecotone, the largest contiguous mangrove forest in North America, is a biogeochemical "hotspot" at the interface of freshwater marsh and the Gulf of Mexico. Over the last one hundred years this region has been impacted by a reduction in freshwater flow and a sea-level rise (SLR) of 2.3 mm/yr which combined to cause a landward shift in the ecotone. This creates an ideal setting to examine climate induced alterations in the mangrove-ecotone biogeochemical cycle. The ability of the Everglades mangrove forest to keep pace with SLR depends largely on the rate of organic matter accumulation as that accumulation is a key contributor to accretion. However, the basic threat from SLR can be exacerbated in some areas by accelerating organic matter mineralization due to increasing salinity. The increase in salinity supplies sulfate which functions as a terminal electron acceptor that soil microbes can utilize to enhance mineralization in the brackish ecotone regions of coastal wetlands. To investigate these processes, we measured mangrove forest soil accretion, OC, N and P accumulation rates over the most recent 10, 50 and 100 year periods (via 210Pb dating) from the Gulf of Mexico to the upper freshwater reaches of the mangrove forest within Everglades National Park. Lower organic carbon accumulation rates compared to the rest of the system were found in the ecotone region most susceptible to enhanced organic matter mineralization.

  8. Study of the influence of different organic pollutants on Cu accumulation by Halimione portulacoides

    Almeida, C. Marisa R.; Claúdia Dias, A.; Mucha, Ana P.; Bordalo, A. A.; Vasconcelos, M. Teresa S. D.

    2009-12-01

    The influence of each of four organic pollutants selected from among those commonly found in coastal areas, 1,1-dichloro-2,2-bis(p-chlorophenyl) ethylene (DDE), monobutyltin (MBT), Triton X-100 and polycyclic aromatic hydrocarbons (PAHs), on Cu accumulation by Halimione portulacoides was investigated. Experiments were carried out in a laboratory setting, either in hydroponics (sediment elutriate) or in a salt marsh sediment ( Cávado River, NW Portugal) soaked in elutriate. Groups of H. portulacoides were exposed to media for 6 days spiked with 10 mg/L Cu(II) and with one of the selected pollutants, at an environmentally realistic concentration. DDE and MBT did not cause any major change on Cu accumulation by H. portulacoides, whereas PAHs slightly increased accumulation only in hydroponics i.e. in the absence of sediment. On the other hand, the non-ionic surfactant Triton X-100 markedly favoured Cu accumulation on plant roots both in the presence and absence of sediment. The addition of DDE, MBT and Triton X-100 also favoured Cu solubility from sediments. Therefore, the simultaneous presence of pollutants from different nature (inorganic and organic) in the estuarine environment may result in a composition of water column, pore water, sediment or biota different of that expected considering the effect of each individual pollutant.

  9. Community Structure Evolution and Enrichment of Glycogen-Accumulating Organisms Producing Polyhydroxyalkanoates from Fermented Molasses▿

    Pisco, Ana R.; Bengtsson, Simon; Werker, Alan; Reis, Maria A. M.; Lemos, Paulo C.

    2009-01-01

    An open mixed culture was enriched with glycogen-accumulating organisms (GAOs) by using a sequencing batch reactor and treating an agroindustrial waste (sugar cane molasses) under cyclic anaerobic-aerobic conditions. Over a 1-year operating period, the culture exhibited a very stable GAO phenotype with an average polyhydroxyalkanoate (PHA) content of 17% total suspended solids. However, the GAO microbial community evolved over the course of operation to a culture exhibiting unusual characteri...

  10. Enrichment of denitrifying glycogen-accumulating organisms in anaerobic/anoxic activated sludge system.

    Zeng, Raymond J; Yuan, Zhiguo; Keller, Jürg

    2003-02-20

    Denitrifying glycogen-accumulating organisms (DGAO) were successfully enriched in a lab-scale sequencing batch reactor (SBR) running with anaerobic/anoxic cycles and acetate feeding during the anaerobic period. Acetate was completely taken up anaerobically, which was accompanied by the consumption of glycogen and the production of poly-beta-hydroxy-alkanoates (PHA). In the subsequent anoxic stage, nitrate or nitrite was utilized as electron acceptor for the oxidation of PHA, resulting in glycogen replenishment and cell growth. The above phenotype showed by the enrichment culture demonstrates the existence of DGAO. Further, it was found that the anaerobic behavior of DGAO could be predicted well by the anaerobic GAO model of Filipe et al. (2001) and Zeng et al. (2002a). The final product of denitrification during anoxic stage was mainly nitrous oxide (N(2)O) rather than N(2). The data strongly suggests that N(2)O production may be caused by the inhibition of nitrous oxide reductase by an elevated level of nitrite accumulated during denitrification. The existence of these organisms is a concern in biological nutrient removal systems that typically have an anaerobic/anoxic/aerobic reactor sequence since they are potential competitors to the polyphosphate-accumulating organisms. PMID:12491525

  11. Deposition and accumulation of airborne organic contaminants in Yosemite National Park, California.

    Mast, M Alisa; Alvarez, David A; Zaugg, Steven D

    2012-03-01

    Deposition and accumulation of airborne organic contaminants in Yosemite National Park were examined by sampling atmospheric deposition, lichen, zooplankton, and lake sediment at different elevations. Passive samplers were deployed in high-elevation lakes to estimate surface-water concentrations. Detected compounds included current-use pesticides chlorpyrifos, dacthal, and endosulfans and legacy compounds chlordane, dichlorodiphenyltrichloroethane-related compounds, dieldrin, hexachlorobenzene, and polychlorinated biphenyls. Concentrations in snow were similar among sites and showed little variation with elevation. Endosulfan concentrations in summer rain appeared to coincide with application rates in the San Joaquin Valley. More than 70% of annual pesticide inputs from atmospheric deposition occurred during the winter, largely because most precipitation falls as snow. Endosulfan and chlordane concentrations in lichen increased with elevation, indicating that mountain cold-trapping might be an important control on accumulation of these compounds. By contrast, chlorpyrifos concentrations were inversely correlated with elevation, indicating that distance from source areas was the dominant control. Sediment concentrations were inversely correlated with elevation, possibly because of the organic carbon content of sediments but also perhaps the greater mobility of organic contaminants at lower elevations. Surface-water concentrations inferred from passive samplers were at sub-parts-per-trillion concentrations, indicating minimal exposure to aquatic organisms from the water column. Concentrations in sediment generally were low, except for dichlorodiphenyldichloroethane in Tenaya Lake, which exceeded sediment guidelines for protection of benthic organisms. PMID:22189687

  12. Process optimization by decoupled control of key microbial populations: distribution of activity and abundance of polyphosphate-accumulating organisms and nitrifying populations in a full-scale IFAS-EBPR plant

    Onnis-Hayden, Annalisa; Majed, Nehreen; Schramm, Andreas;

    2011-01-01

    ammonia concentration becomes limiting. Our results showthat IFAS-EBPR systems enable decoupling of solid residence time (SRT) control for nitrifiers and PAOs that require or prefer conflicting SRT values (e.g. >15 days required for nitrifiers and <5 days preferred for PAOs). Allowing the slow......-growing nitrifiers to attach to the carrier media and the faster-growing phosphorus (P)-removing organisms (and other heterotrophs, e.g. denitrifiers) to be in the suspended mixed liquor (ML), the EBPR-IFAS system facilitates separate SRT controls and overall optimization for both N and P removal processes....

  13. Integrated network modelling for identifying microbial mechanisms of particulate organic carbon accumulation in coastal marine systems

    McDonald, Karlie; Turk, Valentina; Mozetič, Patricija; Tinta, Tinkara; Malfatti, Francesca; Hannah, David; Krause, Stefan

    2016-04-01

    Accumulation of particulate organic carbon (POC) has the potential to change the structure and function of marine ecosystems. High abidance of POC can develop into aggregates, known as marine snow or mucus aggregates that can impair essential marine ecosystem functioning and services. Currently marine POC formation, accumulation and sedimentation processes are being explored as potential pathways to remove CO2 from the atmosphere by CO2 sequestration via fixation into biomass by phytoplankton. However, the current ability of scientists, environmental managers and regulators to analyse and predict high POC concentrations is restricted by the limited understanding of the dynamic nature of the microbial mechanisms regulating POC accumulation events in marine environments. We present a proof of concept study that applies a novel Bayesian Networks (BN) approach to integrate relevant biological and physical-chemical variables across spatial and temporal scales in order to identify the interactions of the main contributing microbial mechanisms regulating POC accumulation in the northern Adriatic Sea. Where previous models have characterised only the POC formed, the BN approach provides a probabilistic framework for predicting the occurrence of POC accumulation by linking biotic factors with prevailing environmental conditions. In this paper the BN was used to test three scenarios (diatom, nanoflagellate, and dinoflagellate blooms). The scenarios predicted diatom blooms to produce high chlorophyll a at the water surface while nanoflagellate blooms were predicted to occur at lower depths (> 6m) in the water column and produce lower chlorophyll a concentrations. A sensitivity analysis identified the variables with the greatest influence on POC accumulation being the enzymes protease and alkaline phosphatase, which highlights the importance of microbial community interactions. The developed proof of concept BN model allows for the first time to quantify the impacts of

  14. Clogging processes caused by biofilms growth and organic particles accumulation in lab-scale vertical flow constructed wetlands

    ZHAO Lianfang; ZHU Wei; TONG Wei

    2009-01-01

    The accumulation of organic matter in substratum pores is regarded as an important factor causing clogging in the subsurface flow constructed wetlands.In this study,the developing process of clogging separately caused by biofilm growth and organic particles accumulation instead of total organic matter accumulation was investigated in two groups of lab-scale vertical flow constructed wetlands (VFCWs) fed with glucose (dissolved organic matter) and starch (particulate organic matter) influent.Results showed that the growth of biofilms within the substratum pores certainly caused remarkable reduction of effective porosity,especially for the strong organic wastewater,whereas its influence on infiltration rate was negligible.It was implied that the most important contribution of biofilm growth to clogging is accelerating the occurrence of clogging.In comparison with biofilm growth,particles accumulation within pores could rapidly reduce infiltration rate besides effective porosity and the clogging occurred in the upper 0-15 cm layer.With approximately equal amount of accumulated organic matter,the effective porosity of the clogged layer in starch-fed systems was far less than that of glucose-fed systems,which indicated that composition and accumulation mode of the accumulated organic matter played an important role in causing clogging besides the amount.According to the results,some related methods to prevent and recover the clogging phenomenon were suggested.

  15. 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

  16. Carbon accumulation in arid croplands of northwest China: pedogenic carbonate exceeding organic carbon

    Wang, Xiujun; Wang, Jiaping; Xu, Minggang; Zhang, Wenju; Fan, Tinglu; Zhang, Juan

    2015-06-01

    Soil carbonate (SIC) exceeds organic carbon (SOC) greatly in arid lands, thus may be important for carbon sequestration. However, field data for quantifying carbonate accumulation have been lacking. This study aims to improve our understanding of SIC dynamics and its role in carbon sequestration. We analyzed two datasets of SOC and SIC and their 13C compositions , one with over 100 soil samples collected recently from various land uses in the Yanqi Basin, Xinjiang, and the other with 18 archived soil samples from a long-term experiment (LTE) in Pingliang, Gansu. The data from the Yanqi Basin showed that SOC had a significant relationship with SIC and pedogenic carbonate (PIC); converting shrub land to cropland increased PIC stock by 5.2 kg C m-2, which was 3.6 times of that in SOC stock. The data from the LTE showed greater accumulation of PIC (21-49 g C m-2 year-1) than SOC (10-39 g C m-2 year-1) over 0-20 cm. Our study points out that intensive cropping in the arid and semi-arid regions leads to an increase in both SOC and PIC. Increasing SOC through straw organic amendments enhances PIC accumulation in the arid cropland of northwestern China.

  17. Accumulation patterns of Cr in Callitriche organs--qualitative and quantitative analysis.

    Augustynowicz, Joanna; Gajewski, Zbigniew; Kostecka-Gugała, Anna; Wróbel, Paweł; Kołton, Anna

    2016-02-01

    The aims of this study were both the qualitative and quantitative analysis of chromium accumulation in the shoots of Callitriche cophocarpa. This globally distributed, submersed macrophyte exhibits outstanding Cr phytoremediation capacity in an aquatic environment. Cr was applied separately for 7 days at two stable forms as Cr(VI) and Cr(III), known from their diverse physicochemical properties and toxicities. The maps of Cr depositions in young leaves, mature leaves, and stems were obtained by micro X-ray fluorescence spectroscopy (μXRF). The detailed analysis of XRF maps was done based on Image-Pro PLUS (Media Cybernetics) software. Cr was accumulated either in trichomes or vascular bundles in respect to the element speciation and the plant organ. The concentration of Cr significantly increased in the following order: Cr(VI) mature leaves < Cr(VI) young leaves = Cr(VI) stems < Cr(III) young leaves ≤ Cr(III) mature leaves ≤ Cr(III) stems. The observed differences in distribution and accumulation of Cr were correlated with the different reduction potential of Cr(VI) by particular plant organs. The reduction of Cr(VI) is considered the main detoxification mechanism of the highly toxic Cr(VI) form. The unique L-band electron resonance spectrometer (L-band EPR) was applied to follow the reduction of Cr(VI) to Cr(III) in the studied material. PMID:26438365

  18. Correlation of resource plays and biodiversity patterns: accumulation of organic-rich shale tracks taxonomic turnover

    Eoff, Jennifer D.

    2012-01-01

    Similar paleogeographic and paleotectonic settings characterize most self-sourced shale hydrocarbon plays. Their deposition occurred within similar orders of magnitude of eustatic events and during geologic periods characterized by “warm” (or transitional) climates and calcitic seas. In addition, the stratigraphic occurrence of shale plays parallels certain historical patterns of marine metazoan biodiversity. Such strong agreement among several correlation tools elucidates why these resources may be limited to discrete intervals of geological time. Correlation of self-sourced shale with biodiversity trends indicates that the factors controlling the deposition of marine organic matter may not be independent of those that induced taxonomic turnover. Paleoecological changes promoted accumulation and preservation of Type II kerogen. Deposition of self-sourced shale appears to correspond to reductions in absolute biodiversity and declining percentages of bioturbating taxa, with concomitant increases in proportions of pelagic taxa relative to infaunal and epifaunal organisms. Whereas upwelling and anoxia may have contributed to the deposition of kerogen in source rocks throughout much of the sedimentary record, diminished consumption of biomass by benthic metazoans likely augmented the preservation of organic carbon during deposition of this shale type. Rapid tectonic-plate reconfiguration induced coeval events, creating basins with sufficiently high rates of accommodation creation necessary to preserve additional organic material accumulating as the heterotrophic benthos suffered in response to rapidly changing environments. Combining sea-level curves, paleogeography, climate, and seawater chemistry provides a first-order approximation of the distribution of potential self-sourced shale in the geologic record. A model that predicts the stratigraphic distribution of self-sourced-shale deposition can aid in exploration of continuous hydrocarbon accumulations in self

  19. Charge injection and accumulation in organic light-emitting diode with PEDOT:PSS anode

    Weis, Martin, E-mail: martin.weis@stuba.sk [Institute of Electronics and Photonics, Slovak University of Technology, Ilkovičova 3, Bratislava 81219 (Slovakia); Otsuka, Takako; Taguchi, Dai; Manaka, Takaaki; Iwamoto, Mitsumasa, E-mail: iwamoto@ome.pe.titech.ac.jp [Department of Physical Electronics, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8552 (Japan)

    2015-04-21

    Organic light-emitting diode (OLED) displays using flexible substrates have many attractive features. Since transparent conductive oxides do not fit the requirements of flexible devices, conductive polymer poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) has been proposed as an alternative. The charge injection and accumulation in OLED devices with PEDOT:PSS anodes are investigated and compared with indium tin oxide anode devices. Higher current density and electroluminescence light intensity are achieved for the OLED device with a PEDOT:PSS anode. The electric field induced second-harmonic generation technique is used for direct observation of temporal evolution of electric fields. It is clearly demonstrated that the improvement in the device performance of the OLED device with a PEDOT:PSS anode is associated with the smooth charge injection and accumulation.

  20. 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.

  1. The accumulation of organic carbon in mineral soils by afforestation of abandoned farmland.

    Xiaorong Wei

    Full Text Available The afforestation of abandoned farmland significantly influences soil organic carbon (OC. However, the dynamics between OC inputs after afforestation and the original OC are not well understood. To learn more about soil OC dynamics after afforestation of farmland, we measured the soil OC content in paired forest and farmland plots in Shaanxi Province, China. The forest plots had been established on farmland 18, 24, 48, 100, and 200 yr previously. The natural (13C abundance of soil organic matter was also analyzed to distinguish between crop- and forest-derived C in the afforested soils. We observed a nonlinear accumulation of total OC in the 0-80 cm depth of the mineral soil across time. Total soil OC accumulated more rapidly under forest stands aged 18 to 48 yr than under forest stands aged 100 or 200 yrs. The rate of OC accumulation was also greater in the 0-10 cm depth than in the 10-80 cm depth. Forest-derived OC in afforested soils also accumulated nonlinearly across time, with the greatest increase in the 0-20 cm depth. Forest-derived OC in afforest soils accounted for 52-86% of the total OC in the 0-10 cm depth, 36-61% of the total OC in the 10-20 cm depth, and 11-50% of the total OC in the 20-80 cm depth. Crop-derived OC concentrations in the 0-20 cm depth decreased slightly after afforestation, but there was no change in crop-derived OC concentrations in the 20-80 cm depth. The results of our study support the claim that afforestation of farmland can sequester atmospheric CO(2 by increasing soil OC stocks. Changes in the OC stocks of mineral soils after afforestation appear to be influenced mainly by the input of forest-derived C rather than by the loss of original OC.

  2. PBDE and PCB accumulation in benthos near marine wastewater outfalls: The role of sediment organic carbon

    Polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) were measured in sediments and benthic invertebrates near submarine municipal outfalls in Victoria and Vancouver, B.C., Canada, two areas with contrasting receiving environments. PBDE concentrations in wastewater exceeded those of the legacy PCBs by eight times at Vancouver and 35 times at Victoria. Total PBDE concentrations in benthic invertebrates were higher near Vancouver than Victoria, despite lower concentrations in sediments, and correlated with organic carbon-normalized concentrations in sediment. Principal Components Analysis indicated uptake of individual PBDE congeners was determined by sediment properties (organic carbon, grain size), while PCB congener uptake was governed by physico-chemical properties (octanol-water partitioning coefficient). Results suggest the utility of sediment quality guidelines for PBDEs and likely PCBs benefit if based on organic carbon-normalized concentrations. Also, where enhanced wastewater treatment increases the PBDEs to particulate organic carbon ratio in effluent, nearfield benthic invertebrates may face increased PBDE accumulation. - Highlights: ► Physical receiving environment affects PBDE bioaccumulation by benthic invertebrates. ► PBDE uptake is correlated with organic-carbon normalized sediment concentrations. ► PBDE and PCB congener uptake are governed by different properties. ► PBDE sediment quality guidelines may benefit by using organic carbon-normalized data. ► Enhanced wastewater treatment may mean increased benthic invertebrate PBDE bioaccumulation. - The physical receiving environment affects the accumulation of PBDEs by benthic invertebrates near submarine municipal outfalls, and uptake of PBDE congeners is governed by different properties than for PCB congeners.

  3. Accumulation of Organic Matter in Infertile Red Soils and Its Ecological Importance

    2000-01-01

    Field experiments on the decomposition of organic materials and the accumulation of organic carbon in infertile red soils were conducted at the Ecological Experimental Station of Red Soil, the Chinese Academy of Sciences, and the potential of CO2 sequestration by reclamation and improving the fertility of these soils was estimated. Results showed that in infertile red soils, the humification coefficients of organic materials were rather high, ranging from 0.28 to 0.63 with an average of 0.43, which was 41% higher than those in corresponding red soils with medium fertility. This was mainly attributed to the high clay content, high acidity and low native organic matter content of infertile red soils. Compared to those in corresponding normal red soils, the decomposition rates of organic materials were significantly lower in infertile red soils in the first 2 years, thereafter no significant difference was observed between those in the two kinds of soils. Depending on the kind and amount of organic manure applied, the soil properties and the rotation systems, annual application of organic manure with a rate of 4 500 to 9 000 kg ha-1 increased the organic carbon content in surface 20 cm of infertile red soils by 2.1~7.5 g kg-1 with an average of 4.7 g kg-1 within the first 5 years. The organic carbon content in infertile red soils which received organic manure annually increased linearly in the first 10 years, thereafter it slowed down, implying that the fertility of the infertile red soils could reach middle or high level in 10 years if the soil was managed properly. It was estimated that through exploitation of wastelands, re-establishment of fuel forests and improvement of soil fertility, soils in red soil region of China could sequester an extra 1.50×1015 g of atmospheric CO2.

  4. Tetrodotoxin--distribution and accumulation in aquatic organisms, and cases of human intoxication.

    Noguchi, Tamao; Arakawa, Osamu

    2008-01-01

    Many pufferfish of the family Tetraodontidae possess a potent neurotoxin, tetrodotoxin (TTX). In marine pufferfish species, toxicity is generally high in the liver and ovary, whereas in brackish water and freshwater species, toxicity is higher in the skin. In 1964, the toxin of the California newt was identified as TTX as well, and since then TTX has been detected in a variety of other organisms. TTX is produced primarily by marine bacteria, and pufferfish accumulate TTX via the food chain that begins with these bacteria. Consequently, pufferfish become non-toxic when they are fed TTX-free diets in an environment in which the invasion of TTX-bearing organisms is completely shut off. Although some researchers claim that the TTX of amphibians is endogenous, we believe that it also has an exogenous origin, i.e., from organisms consumed as food. TTX-bearing animals are equipped with a high tolerance to TTX, and thus retain or accumulate TTX possibly as a biologic defense substance. There have been many cases of human intoxication due to the ingestion of TTX-bearing pufferfish, mainly in Japan, China, and Taiwan, and several victims have died. Several cases of TTX intoxication due to the ingestion of small gastropods, including some lethal cases, were recently reported in China and Taiwan, revealing a serious public health issue. PMID:18728726

  5. Effects of COD to Phosphorus Ratios on the Metabolism of PAOs in Enhanced Biological Phosphorus Removal with Different Carbon Sources

    Tao Jiang; Junguo He; Xiaonan Yang; Jianzheng Li

    2015-01-01

    To elucidate the phosphorus removal and metabolism under various COD/P ratio, a sludge highly enriched in PAOs was used to investigate the impacts of COD/P in batch tests under different carbon supply conditions. Acetate, propionate and a mixture of acetate and propionate at a ratio of 3 ∶ 1 ( COD basis) was used as carbon sources with the COD/P of 20, 15,10 and 5�0 gCOD/gP, respectively. The minimum COD/P ratios for complete P removal were found to be 8�24 gCOD/gP for acetate, 11�40 gCOD/gP for propionate and 9�10 gCOD/gP for the 3 ∶ 1 mixture of acetate and propionate. Converted to a mass basis, all three cases had a very similar ratio of 7�7 gVFA/gP, which represented a useful guide for operation of EBPR plants to identify possible shortages inVFAs. The trend in PHV accumulation during the anaerobic period along with the decrease of COD/P ratios suggested that, PAOs may use the TCA pathway for anaerobic VFA uptake to maintain the required NADH production with reduced glycogen degradation. During the aerobic phase, the glycogen pool was reduced but remained enough compared to the requirement for anaerobic VFA uptake, and the synthesis and degradation of glycogen was not the inhibition factor of PAOs.

  6. Chemical Form Matters: Differential Accumulation of Mercury Following Inorganic and Organic Mercury Exposures in Zebrafish Larvae

    Korbas, Malgorzata; MacDonald, Tracy C.; Pickering, Ingrid J.; George, Graham N.; Krone, Patrick H. (Saskatchewan)

    2013-04-08

    Mercury, one of the most toxic elements, exists in various chemical forms each with different toxicities and health implications. Some methylated mercury forms, one of which exists in fish and other seafood products, pose a potential threat, especially during embryonic and early postnatal development. Despite global concerns, little is known about the mechanisms underlying transport and toxicity of different mercury species. To investigate the impact of different mercury chemical forms on vertebrate development, we have successfully combined the zebrafish, a well-established developmental biology model system, with synchrotron-based X-ray fluorescence imaging. Our work revealed substantial differences in tissue-specific accumulation patterns of mercury in zebrafish larvae exposed to four different mercury formulations in water. Methylmercury species not only resulted in overall higher mercury burdens but also targeted different cells and tissues than their inorganic counterparts, thus revealing a significant role of speciation in cellular and molecular targeting and mercury sequestration. For methylmercury species, the highest mercury concentrations were in the eye lens epithelial cells, independent of the formulation ligand (chloride versus L-cysteine). For inorganic mercury species, in absence of L-cysteine, the olfactory epithelium and kidney accumulated the greatest amounts of mercury. However, with L-cysteine present in the treatment solution, mercuric bis-L-cysteineate species dominated the treatment, significantly decreasing uptake. Our results clearly demonstrate that the common differentiation between organic and inorganic mercury is not sufficient to determine the toxicity of various mercury species.

  7. Peculiarities of radionuclides' accumulation in benthic organisms and fish in the Barents and Kara Seas

    This work contributes to the joint research programme between the Finnish Centre for Radiation and Nuclear Safety and the Murmansk Marine Biological Institute in the Arctic. Attention has been focussed to measuring amounts and locating possible sources of artificial radionuclides in the Russian Arctic Sea area. Sediments, algae, bottom fauna and fish samples were collected during several scientific expeditions in 1993 and 1994. The results on radionuclide accumulation in benthic organisms and fish are presented in this paper. It is concluded that the concentration of 137Cs in benthic fauna and commercial fish and algae of the Barents and Kara Seas is generally low and originates from the global fallout. The highest levels of 137Cs are determined in the animals inhabiting the silty bottom 6 refs., 3 figs

  8. Intracellular Accumulation of Glycine in Polyphosphate-Accumulating Organisms in Activated Sludge, a Novel Storage Mechanism under Dynamic Anaerobic-Aerobic Conditions.

    Nguyen, Hien Thi Thu; Kristiansen, Rikke; Vestergaard, Mette; Wimmer, Reinhard; Nielsen, Per Halkjær

    2015-07-01

    Dynamic anaerobic-aerobic feast-famine conditions are applied to wastewater treatment plants to select polyphosphate-accumulating organisms to carry out enhanced biological phosphorus removal. Acetate is a well-known substrate to stimulate this process, and here we show that different amino acids also are suitable substrates, with glycine as the most promising. (13)C-labeled glycine and nuclear magnetic resonance (NMR) were applied to investigate uptake and potential storage products when activated sludge was fed with glycine under anaerobic conditions. Glycine was consumed by the biomass, and the majority was stored intracellularly as free glycine and fermentation products. Subsequently, in the aerobic phase without addition of external substrate, the stored glycine was consumed. The uptake of glycine and oxidation of intracellular metabolites took place along with a release and uptake of orthophosphate, respectively. Fluorescence in situ hybridization combined with microautoradiography using (3)H-labeled glycine revealed uncultured actinobacterial Tetrasphaera as a dominant glycine consumer. Experiments with Tetrasphaera elongata as representative of uncultured Tetrasphaera showed that under anaerobic conditions it was able to take up labeled glycine and accumulate this and other labeled metabolites to an intracellular concentration of approximately 4 mM. All components were consumed under subsequent aerobic conditions. Intracellular accumulation of amino acids seems to be a novel storage strategy for polyphosphate-accumulating bacteria under dynamic anaerobic-aerobic feast-famine conditions. PMID:25956769

  9. Initial cerebral HM-PAO distribution compared to LCBF: use of a model which considers cerebral HM-PAO trapping kinetics

    The cerebral uptake of [99mTc]-d,l-hexamethylpropyleneamine oxime complex (HM-PAO) was compared to LCBF determined simultaneously with [14C]iodoantipyrine (IAP) using double radionuclide quantitative digital autoradiography. Awake male rats were given intravenous injections of a mixture of 50 microCi IAP and 15 mCi of HM-PAO and killed 20 s after tracer activity had first reached the brain. Two separate autoradiograms were produced from each 20 microns brain section. The autoradiograms were digitized, corrected for cross-contamination, and then converted into images of individual tracer concentration. The diffusible tracer model was used to convert the IAP concentration images into LCBF images. Regional HM-PAO concentration was found not to be linearly related to LCBF as determined with the IAP, and therefore a simple microsphere type model was inadequate in relating HM-PAO uptake to LCBF. A better HM-PAO uptake--LCBF correlation was obtained when the HM-PAO arterial input function was corrected for very rapidly produced, non-cerebrally extracted, metabolites and a kinetic model was used that considered the rate of intracerebral metabolism of HM-PAO to a retained metabolite. Even using this model, however, some differences between HM-PAO uptake and LCBF occurred in certain brain regions. Because these differences were small and the HM-PAO uptake pattern has been shown to be constant for many minutes, HM-PAO can probably be used to estimate LCBF in patients with single positron emission computed tomography (SPECT) imaging

  10. Organ-specific accumulation, transportation, and elimination of methylmercury and inorganic mercury in a low Hg accumulating fish.

    Peng, Xiaoyan; Liu, Fengjie; Wang, Wen-Xiong

    2016-08-01

    Low mercury (Hg) concentrations down to several nanograms Hg per gram of wet tissue are documented in certain fish species such as herbivorous fish, and the underlying mechanisms remain speculative. In the present study, bioaccumulation and depuration patterns of inorganic Hg(II) and methylmercury (MeHg) in a herbivorous rabbitfish Siganus canaliculatus were investigated at organ and subcellular levels following waterborne or dietary exposures. The results showed that the efflux rate constants of Hg(II) and MeHg were 0.104 d(-1) and 0.024 d(-1) , respectively, and are probably the highest rate constants recorded in fish thus far. The dietary MeHg assimilation efficiency (68%) was much lower than those in other fish species (∼90%). The predominant distribution of MeHg in fish muscle was attributable to negligible elimination of MeHg from muscle (< 0) and efficient elimination of MeHg from gills (0.12 d(-1) ), liver (0.17 d(-1) ), and intestine (0.20 d(-1) ), as well as efficient transportation of MeHg from other organs into muscle. In contrast, Hg(II) was much more slowly distributed into muscle but was efficiently eliminated by the intestine (0.13 d(-1) ). Subcellular distribution indicated that some specific membrane proteins in muscle were the primary binding pools for MeHg, and both metallothionein-like proteins and Hg-rich granules were the important components in eliminating both MeHg and Hg(II). Overall, the present study's results suggest that the low tissue Hg concentration in the rabbitfish was partly explained by its unique biokinetics. Environ Toxicol Chem 2016;35:2074-2083. © 2016 SETAC. PMID:26756981

  11. An alternative approach to reconstructing organic matter accumulation with contrasting watershed disturbance histories from lake sediments

    A number of proxies, including carbon to nitrogen ratio (C:N) and stable isotopes (δ13C and δ15N), have been used to reconstruct organic matter (OM) profiles from lake sediments and these proxies individually or in combination cannot clearly discriminate different sources. Here we present an alternative approach to elucidate this problem from lake sediments as a function of watershed scale land use changes. Stable isotope signatures of defined OM sources from the study watersheds, Shawnigan Lake (SHL) and Elk Lake (ELL), were compared with sedimentary proxy records. Results from this study reveal that terrestrial inputs and catchment soil coinciding with the watershed disturbances histories probably contributed in recent trophic enrichment in SHL. In contrast, cultural eutrophication in ELL was partially a result of input from catchment soil (agricultural activities) with significant input from lake primary production as well. Results were consistent in both IsoSource (IsoSource version 1.2 is a Visual Basic program used for source separation, ( (http://www.epa.gov/wed/pages/models/isosource/isosource.htm)) and discriminant analysis (statistical classification technique). - The study shows an alternative approach to reconstruct organic matter accumulation using stable isotopes from lake sediments

  12. Community structure evolution and enrichment of glycogen-accumulating organisms producing polyhydroxyalkanoates from fermented molasses.

    Pisco, Ana R; Bengtsson, Simon; Werker, Alan; Reis, Maria A M; Lemos, Paulo C

    2009-07-01

    An open mixed culture was enriched with glycogen-accumulating organisms (GAOs) by using a sequencing batch reactor and treating an agroindustrial waste (sugar cane molasses) under cyclic anaerobic-aerobic conditions. Over a 1-year operating period, the culture exhibited a very stable GAO phenotype with an average polyhydroxyalkanoate (PHA) content of 17% total suspended solids. However, the GAO microbial community evolved over the course of operation to a culture exhibiting unusual characteristics in producing PHAs comprised of short-chain-length monomers, namely, 3-hydroxybutyrate, 3-hydroxy-2-methylbutyrate, 3-hydroxyvalerate, and 3-hydroxy-2-methylvalerate, and also, up to 31 mol% of the medium-chain-length (MCL) monomer 3-hydroxyhexanoate (3HHx). Microbial community analysis by fluorescence in situ hybridization revealed a concurrent long-term drift in the GAO community balance, from mainly "Candidatus Competibacter phosphatis" to mainly Defluviicoccus vanus-related organisms. The production of 3HHx was confirmed by (13)C nuclear magnetic resonance (NMR) and appeared to be related to the increased presence of D. vanus-related GAOs. These results suggest a broadened spectrum of material, chemical, and mechanical properties that can be achieved for biopolymers produced by open mixed cultures from fermented waste. The increased spectrum of polymer properties brings a wider scope of potential applications. PMID:19465533

  13. Silver nanoparticle accumulation by aquatic organisms – neutron activation as a tool for the environmental fate of nanoparticles tracing

    Asztemborska Monika

    2014-12-01

    Full Text Available Water environments are noted as being some of the most exposed to the influence of toxic nanoparticles (NPs. Therefore, there is a growing need for the investigation of the accumulation and toxicity of NPs to aquatic organisms. In our studies neutron activation followed by gamma spectrometry and liquid scintillation counting were used for studying the accumulation of silver nanoparticles (AgNPs by freshwater larvae of Chironomus and fish Danio rerio. The influence of exposition time, concentration and the source of nanoparticles on the efficiency of AgNP accumulation were studied. It was found that AgNPs are efficiently accumulated by Chironomid larvae for the first 30 hours of exposition; then, the amount of silver nanoparticles decreases. The silver content in larvae increases together with the NP concentration in water. Larvae which have accumulated AgNPs can be a source of nanoparticles for fish and certainly higher levels of Ag in the trophic chain. In comparison with water contamination, silver nanoparticles are more efficiently accumulated if fish are fed with AgNP-contaminated food. Finally, it was concluded that the applied study strategy, including neutron activation of nanoparticles, is very useful technique for tracing the uptake and accumulation of NPs in organisms

  14. Spatial variation of salt-marsh organic and inorganic deposition and organic carbon accumulation: Inferences from the Venice lagoon, Italy

    Roner, M.; D'Alpaos, A.; Ghinassi, M.; Marani, M.; Silvestri, S.; Franceschinis, E.; Realdon, N.

    2016-07-01

    inorganic soil content near the edge is due to the preferential deposition of inorganic sediment from the adjacent creek, and to the rapid decomposition of the relatively large biomass production. The higher organic matter content in the inner part of the marsh results from the small amounts of suspended sediment that makes it to the inner marsh, and to the low decomposition rate which more than compensates for the lower biomass productivity in the low-lying inner zones. Finally, the average soil organic carbon density from the LOI measurements is estimated to be 0.044 g C cm-3. The corresponding average carbon accumulation rate for the San Felice and Rigà salt marshes, 132 g C m-2 yr-1, highlights the considerable carbon stock and sequestration rate associated with coastal salt marshes.

  15. [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

  16. Accumulation kinetics and equilibrium partitioning coefficients for semivolatile organic pollutants in forest litter.

    Nizzetto, Luca; Liu, Xiang; Zhang, Gan; Komprdova, Klara; Komprda, Jiri

    2014-01-01

    Soils are important stores of environmentally cycling semivolatile organic contaminants (SVOCs) and represent relevant atmospheric secondary sources whenever environmental conditions favor re-emission. The exchange between air and soil is controlled by resistances posed by interfacial matrices such as the ubiquitously distributed vegetation litter. For the first time, this study focused on the experimental characterization of accumulation parameters for SVOCs in litter under real field conditions. The logarithm of the litter-air equilibrium partitioning coefficient ranged 6.8-8.9 and had a similar dependence on logKOA as that of plant foliage and soil data. Uptake and release rates were also KOA dependent with values (relevant for real environmental conditions) ranging 30,000-150,000 d(-1) and 0.0004-0.0134 d(-1), respectively. The overall mass transfer coefficient v controlling litter-air exchange (0.03-1.4 cm s(-1)) was consistent with previously reported data of v for foliage in forest canopies after normalization on leaf area index. Obtained data suggest that litter holds the potential for influencing atmospheric fugacity in proximity to soil, likely affecting overall exchange of SVOCs between the soil reservoir and the atmosphere. PMID:24320106

  17. Effect of organic carbon and metal accumulation on the bacterial communities in sulphidogenic sediments.

    Bueche, Matthieu; Junier, Pilar

    2016-06-01

    A unique geochemical setting in Lake Cadagno, Switzerland, has led to the accumulation of insoluble metal sulphides in the sedimentary record as the result of past airborne pollution. This offers an exceptional opportunity to study the effect of these metals on the bacterial communities in sediments, and in particular to investigate further the link between metal contamination and an increase in the populations of endospore-forming bacteria observed previously in other metal-contaminated sediments. A decrease in organic carbon and total bacterial counts was correlated with an increase in the numbers of endospores in the oldest sediment samples, showing the first environmental evidence of a decrease in nutrient availability as a trigger of sporulation. Proteobacteria and Firmicutes were the two dominant bacterial phyla throughout the sediment, the former in an area with high sulphidogenic activity, and the latter in the oldest samples. Even though the dominant Firmicutes taxa were stable along the sediment core and did not vary with changes in metal contamination, the prevalence of some molecular species like Clostridium sp. was positively correlated with metal sulphide concentration. However, this cannot be generalized to all endospore-forming species. Overall, the community composition supports the hypothesis of sporulation as the main mechanism explaining the dominance of endospore formers in the deepest part of the sediment core, while metal contamination in the form of insoluble metal sulphide deposits appears not to be linked with sporulation as a mechanism of metal tolerance in this sulphidogenic ecosystem. PMID:26780045

  18. Anaerobic biodegradability and digestion in accumulation systems for concentrated black water and kitchen organic-wastes.

    Elmitwalli, T A; van Leeuwen, M; Kujawa-Roeleveld, K; Sanders, W; Zeeman, G

    2006-01-01

    The feasibility of two accumulation-systems (AC) for anaerobic digestion and storage of concentrated black water with (AC1) or without (AC2) urine + kitchen organic-wastes was investigated. The waste(water) was collected by two vacuum toilet/transport systems. The influent-total COD of the AC2 (53,000 mg/L) was more concentrated by four times than that of the AC1. The suspended COD represented the major part (71-73%) of influent total COD of the two systems. The batch-experiments results showed a high anaerobic biodegradability of the waste(water) (> 85%). The AC systems demonstrated stable performance. There was no inhibition effect of NH4 and VFA concentration decreased in time. Total COD removal of 58% was achieved in both systems, after 105 days at 20 degrees C. Moreover, if only the supernatant in AC1 is withdrawn and the settled sludge stays for the next runs, only 20% of the influent total COD will be in the supernatant. In AC2, 74% of influent ortho-P was removed by precipitation. Therefore, the settled sludge in the AC2 had a high total-P concentration of 1,300 mg/L. The C:N:P ratios of the supernatant and the sludge were 26:13:1 and 35:4.5:1, respectively, in the AC1, and were 28:14:1 and 32:2.4:1, respectively, in AC2. PMID:16784201

  19. Building Bridges to the Middle Class: The Role of Community-Based Organizations in Asian American Wealth Accumulation

    R. Varisa Patraporn; Deirdre Pfeiffer; Paul Ong

    2010-01-01

    Despite the increasing provision of social and financial services by community-based organizations (CBOs), few studies focus on the roles that Asian American-serving CBOs play in helping their economically and culturally diverse communities accumulate wealth. The authors explore this overlooked sector by interviewing key informants in 30 mostly Asian American asset-building organizations nationwide. Participating CBOs respond to the financial needs of their diverse communities primarily in th...

  20. Impact of organic nutrient load on biomass accumulation, feed channel pressure drop increase and permeate flux decline in membrane systems

    Bucs, Szilard

    2014-12-01

    The influence of organic nutrient load on biomass accumulation (biofouling) and pressure drop development in membrane filtration systems was investigated. Nutrient load is the product of nutrient concentration and linear flow velocity. Biofouling - excessive growth of microbial biomass in membrane systems - hampers membrane performance. The influence of biodegradable organic nutrient load on biofouling was investigated at varying (i) crossflow velocity, (ii) nutrient concentration, (iii) shear, and (iv) feed spacer thickness. Experimental studies were performed with membrane fouling simulators (MFSs) containing a reverse osmosis (RO) membrane and a 31 mil thick feed spacer, commonly applied in practice in RO and nanofiltration (NF) spiral-wound membrane modules. Numerical modeling studies were done with identical feed spacer geometry differing in thickness (28, 31 and 34 mil). Additionally, experiments were done applying a forward osmosis (FO) membrane with varying spacer thickness (28, 31 and 34 mil), addressing the permeate flux decline and biofilm development. Assessed were the development of feed channel pressure drop (MFS studies), permeate flux (FO studies) and accumulated biomass amount measured by adenosine triphosphate (ATP) and total organic carbon (TOC).Our studies showed that the organic nutrient load determined the accumulated amount of biomass. The same amount of accumulated biomass was found at constant nutrient load irrespective of linear flow velocity, shear, and/or feed spacer thickness. The impact of the same amount of accumulated biomass on feed channel pressure drop and permeate flux was influenced by membrane process design and operational conditions. Reducing the nutrient load by pretreatment slowed-down the biofilm formation. The impact of accumulated biomass on membrane performance was reduced by applying a lower crossflow velocity and/or a thicker and/or a modified geometry feed spacer. The results indicate that cleanings can be delayed

  1. The effect of soil macrofauna on organic matter accumulation and soil formation in post-mining landscape

    Frouz, Jan

    Budapest : Institute of Ecology and Botany HAS, 2002. s. 85-86. [European Conference on Restoration Ecology /3./. 25.08.2002-31.08.2002, Budapest] Institutional research plan: CEZ:AV0Z6066911 Keywords : soil macrofauna * organic matter accumulation * post-mining landscape Subject RIV: EH - Ecology, Behaviour

  2. Differences in technetium-99 accumulation and distribution between organs in male and female lobsters collected from Norwegian coastal waters

    In this report, 99Tc results for lobsters caught along the Norwegian coast between 2001 and 2005 are presented. The high accumulation of 99Tc in lobsters compared to other crustecea is confirmed in this report, as well as the clear differences between males and females. Concentration factors have been estimated for each gender and also for different organs. (author)

  3. Weed management practices for organic production of trailing blackberry. II. Accumulation and loss of plant biomass and nutrients

    A study was conducted to assess the impact of cultivar and weed management on accumulation and loss of plant biomass and nutrients during the first 3 years of establishment when using organic fertilizer in trailing blackberry. Treatments included two cultivars, Marion and Black Diamond, each with ei...

  4. Conversion from cropland to short rotation coppice willow and poplar: Accumulation of soil organic carbon

    Georgiadis, Petros; Stupak, Inge; Vesterdal, Lars; Raulund-Rasmussen, Karsten

    2015-04-01

    it was not significant. The increasing soil carbon stocks in SRC stands on former cropland can be attributed to the increased leaf and litter input from the perennial SRC plantations as well as less stimulation of organic matter decomposition after cessation of annual. Initial losses of soil carbon after the land use change have also been reported by other studies, but the soil carbon accumulation high rates suggest that SRC can act as sinks at least for some decades. Our results indicate that a steady state has not yet been reached after 29 years. Key words: Bioenergy,Land Use Change, poplar, Short Rotation Coppice, Soil Organic Carbon, willow,

  5. Pseudomonas aeruginosa PAO1 Pyocin Production Affects Population Dynamics within Mixed-Culture Biofilms▿ †

    Waite, Richard D.; Curtis, Michael A.

    2008-01-01

    Transcriptomic and phenotypic studies showed that pyocins are produced in Pseudomonas aeruginosa PAO1 aerobic and anaerobic biofilms. Pyocin activity was found to be high in slow-growing anaerobic biofilms but transient in aerobic biofilms. Biofilm coculture of strain PAO1 and a pyocin-sensitive isolate showed that pyocin production had a significant impact on bacterial population dynamics, particularly under anaerobic conditions.

  6. Factors controlling accumulation of soil organic carbon along vegetation succession in a typical karst region in Southwest China.

    Liu, Shujuan; Zhang, Wei; Wang, Kelin; Pan, Fujing; Yang, Shan; Shu, Shiyan

    2015-07-15

    Vegetation succession enhances the accumulation of carbon in the soil. However, little is known about the mechanisms underlying soil organic carbon (SOC) accumulation in different vegetation types in the karst region of Southwest China. The goal of this study was to identify and prioritize the effects of environmental parameters, including soil physico-chemical properties, microbial biomass, enzyme activities, and litter characteristics, on SOC accumulation along a vegetation succession sere (grassland, shrubland, secondary forest, and primary forest) in the karst landscape of Southwest China. Relationships between these parameters and SOC were evaluated by redundancy analysis. The results showed that SOC accumulation was significantly different among vegetation types (Pforest). Soil biochemistry and physical characteristics significantly affected the accumulation of SOC. Soil microbial biomass showed a predominant effect on SOC in each of the four vegetation types. In addition, the soil physical property (especially the silt content) was another controlling factor in the early stages (grassland), and urease activity and saccharase activity were important controlling factors in the early-middle and middle-late stages, respectively. Litter characteristics only showed mild effects on SOC accumulation. Variation partitioning analysis showed that the contribution of sole main factors to SOC variation decreased, while the interaction effect among parameters increased along the succession gradient. PMID:25828412

  7. ACCUMULATION OF POLYCHLORINATED ORGANIC CONTAMINANTS FROM SEDIMENT BY THREE BENTHIC MARINE SPECIES

    A laboratory experiment was conducted to measure the accumulation of selected polychlorinated compounds by marine benthos exposed to environmentally contaminated sediment. andworms (Nereis virens), clams (Macoma nasuta), and grass shrimp (Palaemonetes pugio) were exposed to sedim...

  8. Radiopharmacokinetics and incorporation dosimetry from 99mTc-HM-PAO

    After intravenous injection of 185 MBq 99mTc-hexamethylpropyleneamineoxime (HM-PAO) long-time retention measurements were made on four healthy voluntary subjects up to 72 hours. Whole body profiles as a function of time were measured with a whole body counter. From the whole body profiles in man only the total body retention and the retention in the brain could be calculated. For this reason, biokinetic animal data were collected from quantitative organ measurements in mice. The biokinetic animal data were transferred to man as the cumulative activity for the various organs. The mean absorbed dose for selected organs was calculated using the concept of absorbed fractions (MIRD method). Except the thyroid gland the absorbed dose for all selected organs is within the range from 2.8 μGy/MBq for the testes to 10.4 μGy/MBq for the upper large intestinal wall. The thyroid gland receives the highest dose of all organs considered (24.3 μGy/MBq). The absorbed dose to the brain derived from human data (10.3 μGy/MBq) exceeds that derived from animal data by a factor of about 2. (orig.)

  9. A Study on Organic Inclusions in Clastic Reservoir Rocks and Their Application to the Assessment of Oil and Gas Accumulations

    张文淮; 张志坚; 等

    1996-01-01

    Terrigenous clastic reservoir rocks are widespread in China,and nearly all the industrial oil and gas accumulations in eastern China occur in the clastic rocks.The study shows that organic inclusions are mostly distributed in the secondary fissures and pores which were ormed in the process of oil-rock interaction,rather than in the cements or secondary enlargements. The organic inclusions are dominantly organic gas-rich or are composed of pure hydrocarbons.Homogenization temperatures range mainly from 120℃ to 130℃,which shows a relatively high maturity of organic matter.Vertical and horizontal temperature changes provide the grounds for the investigation of basin evolution and thermal fluid-kinetics-model.Fluorescence spectral characteristics o the organic inclusions indicate that oils and gases in the area studied probably have experienced two-stage or two-time migration.Micro-fluorescence rescearch is one of the effective approaches to oil/source correlation and oil migration-stage determination.The abundance and occurrence of organic inclusions is one of the indicators of oil and gas abundance and accumulation in rock layers.With the help of other informatio,organic inclusions can provide the basis for the prospective assessment of oil and gas in clastic reservoir rocks.

  10. Factors controlling accumulation of soil organic carbon along vegetation succession in a typical karst region in Southwest China

    Vegetation succession enhances the accumulation of carbon in the soil. However, little is known about the mechanisms underlying soil organic carbon (SOC) accumulation in different vegetation types in the karst region of Southwest China. The goal of this study was to identify and prioritize the effects of environmental parameters, including soil physico-chemical properties, microbial biomass, enzyme activities, and litter characteristics, on SOC accumulation along a vegetation succession sere (grassland, shrubland, secondary forest, and primary forest) in the karst landscape of Southwest China. Relationships between these parameters and SOC were evaluated by redundancy analysis. The results showed that SOC accumulation was significantly different among vegetation types (P < 0.01) and increased with vegetation succession (from 29.10 g·kg−1 in grassland to 73.92 g·kg−1 in primary forest). Soil biochemistry and physical characteristics significantly affected the accumulation of SOC. Soil microbial biomass showed a predominant effect on SOC in each of the four vegetation types. In addition, the soil physical property (especially the silt content) was another controlling factor in the early stages (grassland), and urease activity and saccharase activity were important controlling factors in the early-middle and middle-late stages, respectively. Litter characteristics only showed mild effects on SOC accumulation. Variation partitioning analysis showed that the contribution of sole main factors to SOC variation decreased, while the interaction effect among parameters increased along the succession gradient. - Highlights: • Vegetation restoration is conducive to soil carbon sequestration in karst areas. • The factors controlling SOC accumulation differed along vegetation succession. • The interaction effect among significant factors became more and more prominent along succession

  11. Factors controlling accumulation of soil organic carbon along vegetation succession in a typical karst region in Southwest China

    Liu, Shujuan [Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125 (China); Huanjiang Observation and Research Station of Karst Ecosystem, Chinese Academy of Sciences, Huanjiang, Guangxi Zhuang Autonomous Region 547100 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Zhang, Wei [Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125 (China); Huanjiang Observation and Research Station of Karst Ecosystem, Chinese Academy of Sciences, Huanjiang, Guangxi Zhuang Autonomous Region 547100 (China); Wang, Kelin, E-mail: kelin@isa.ac.cn [Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125 (China); Huanjiang Observation and Research Station of Karst Ecosystem, Chinese Academy of Sciences, Huanjiang, Guangxi Zhuang Autonomous Region 547100 (China); Pan, Fujing [Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125 (China); Huanjiang Observation and Research Station of Karst Ecosystem, Chinese Academy of Sciences, Huanjiang, Guangxi Zhuang Autonomous Region 547100 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Yang, Shan [Changsha university, Changsha 410003 (China); Shu, Shiyan [Changjiang Project Supervision & Consultancy Co. Ltd, Wuhan 430010 (China); Changjiang Ecology (Hubei) Technology Development LLC, Wuhan 430010 (China)

    2015-07-15

    Vegetation succession enhances the accumulation of carbon in the soil. However, little is known about the mechanisms underlying soil organic carbon (SOC) accumulation in different vegetation types in the karst region of Southwest China. The goal of this study was to identify and prioritize the effects of environmental parameters, including soil physico-chemical properties, microbial biomass, enzyme activities, and litter characteristics, on SOC accumulation along a vegetation succession sere (grassland, shrubland, secondary forest, and primary forest) in the karst landscape of Southwest China. Relationships between these parameters and SOC were evaluated by redundancy analysis. The results showed that SOC accumulation was significantly different among vegetation types (P < 0.01) and increased with vegetation succession (from 29.10 g·kg{sup −1} in grassland to 73.92 g·kg{sup −1} in primary forest). Soil biochemistry and physical characteristics significantly affected the accumulation of SOC. Soil microbial biomass showed a predominant effect on SOC in each of the four vegetation types. In addition, the soil physical property (especially the silt content) was another controlling factor in the early stages (grassland), and urease activity and saccharase activity were important controlling factors in the early-middle and middle-late stages, respectively. Litter characteristics only showed mild effects on SOC accumulation. Variation partitioning analysis showed that the contribution of sole main factors to SOC variation decreased, while the interaction effect among parameters increased along the succession gradient. - Highlights: • Vegetation restoration is conducive to soil carbon sequestration in karst areas. • The factors controlling SOC accumulation differed along vegetation succession. • The interaction effect among significant factors became more and more prominent along succession.

  12. Soil organic carbon accumulation in afforested/abandoned arable fields in Taiwan

    Lin, Yi-Han; Cheng, Chih-Hsin; Huang, Yu-Hsuan

    2016-04-01

    Afforestation or abandonment of arable fields has been proposed as a way to increase terrestrial carbon storage and mitigate anthropogenic carbon emissions. When the arable fields are afforested or abandoned, the accumulation in soil organic carbon (SOC) is a key pool to sequestrate carbon. However, high uncertainties still exist in the tropics and subtropics because of fast SOC turnover rates and variable land use managements in these areas. In this study, a total of eleven sites with afforested/abandoned age over 15 years and elevation ranging from 16 to 2,056 m were investigated. We examined the increments of SOC by comparing with the adjacent tilled (e.g. croplands) and non-tilled (e.g. tea plantation or orchards) fields in two sampling layers, 0 - 10 and 10 - 20 cm in depth. In addition, density fractionation of SOC was also conducted in order to differentiate SOC into light fraction, intra-aggregate fraction, and heavy fraction to gain more information about the mechanism of SOC sequestration. Our results indicated that the increments of SOC concentration and stock varied with elevation, land use management, and soil depth. For the sites with elevation below 500 m, the SOC concentration and stock in the abandoned fields were 14.3 ± 0.9 mg C g‑1 and 14.6 ± 4.6 Mg C ha‑1 higher than the adjacent tilled fields, and 10.2 ± 6.3 mg C g‑1and 6.4 ± 6.2 Mg C ha‑1 higher than the adjacent non-tilled fields for surface 0-10 cm. For the sites with elevation above 500 m, the SOC concentration in the abandoned arable fields were 22.8 ± 12.8 mg C g‑1 higher than the adjacent tilled fields, but the SOC stock might not be different due to high stone content in abandoned field. Moreover, the SOC concentration and stock in abandoned field were not different or even less than non-tilled fields where organic amendments were frequently applied. The increments of SOC for 10-20 cm soils were less evident than those for surface 0-10 cm soils, and the differences were

  13. 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

  14. Safety evaluation of pectin-derived acidic oligosaccharides (pAOS): Genotoxicity and sub-chronic studies

    Garthoff, J.A.; Heemskerk, S.; Hempenius, R.A.; Lina, B.A.R.; Krul, C.A.M.; Koeman, J.H.; Speijers, G.J.A.

    2010-01-01

    Pectin-derived acidic oligosaccharides (pAOS) are non-digestible carbohydrates to be used in infant formulae and medical nutrition. To support its safety, the genotoxic potential of pAOS was evaluated. pAOS was not mutagenic in the Ames test. Positive results were obtained in the chromosome aberrati

  15. 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.

  16. Denitrifying capability and community dynamics of glycogen accumulating organisms during sludge granulation in an anaerobic-aerobic sequencing batch reactor

    Zhang Bin; Xue Bin; Qiu Zhigang; Chen Zhiqiang; Li Junwen; Gong Taishi; Zou Wenci; Wang Jingfeng

    2015-01-01

    Denitrifying capability of glycogen accumulating organisms (GAOs) has received great attention in environmental science and microbial ecology. Combining this ability with granule processes would be an interesting attempt. Here, a laboratory-scale sequencing batch reactor (SBR) was operated to enrich GAOs and enable sludge granulation. The results showed that the GAO granules were cultivated successfully and the granules had denitrifying capability. The batch experiments demonstrated that all ...

  17. Synthesis of the d,I-HM-PAO and formulation of nucleo-equipment for the obtention of 99m Tc-(d,I)-HM-PAO

    Most brain imaging radiopharmaceuticals are conventional hydrophilic compounds that are excluded from entering the normal brain by an intact blood-brain barrier (BBB). Under pathologic conditions, the barrier is disrupted and radiotracer concentrates in the leisure for positive identification. 99m Tc- hexa methyl propylene amine oxime (99m Tc-HM-PAO) is a newer-type lipophilic agent that enter the normal brain through an intact BBB. Studies with this agent offer the promise of measuring cerebral perfusion in the normal and diseased brain. In this paper we present the synthesis and Tc-99m labelling of d,I-HM-PAO. The synthesis of the ligand was carried out by condensation of two molecular equivalents of butanedione monoxime with one molecular equivalent of 1,3 propanediamine provided a bis imine intermediate, which was reduced with sodium borohydride to get the meso and d,I diastereoisomers of HM-PAO. Separation of these was achieved by fractional crystallization. 99m Tc-(d,I)HM-PAO was obtained by stannous ion reduction of Mo-99/Tc-99m generator eluate in the presence of the ligand. Complex radiochemical purity was determined by instant thin layer chromatography and paper chromatography. Finally, we obtained 99m Tc-(d,I)HM-PAO with a high radiochemical yield, in excess of 90%. However, for subsequent clinical studies the preparation has to be done a few minutes before application because our product has a low stability. (Author)

  18. Modern accumulation rates and sources of organic carbon in the NE Gulf of Cadiz (SW Iberian Peninsula)

    Organic carbon (OC) content, elemental (C/N) and isotopic (δ 13C) composition of organic matter (OM) constrain relative contributions from both marine and terrestrial sources to modern sediments in the NE Gulf of Cadiz (GoC) shelf. C/N and (δ 13C) indicate a transition from a dominantly marine to a terrestrial input of OM deposited in Bay of Cadiz and the Guadalquivir prodelta. OC and mass accumulation rates (MARs, based on bulk density and 210Pb-derived sediment MAR) suggest that labile OM from primary productivity accounts for the low OC content and burial rates in sediments in the NE GoC shelf. (author)

  19. Evolution and accumulation of organic foulants on hydrophobic and hydrophilic membrane surfaces in a submerged membrane bioreactor

    Matar, Gerald

    2015-09-07

    Membrane surface modification is attracting more attention to mitigate biofouling in membrane bioreactors (MBRs). Five membranes differing in chemistry and hydrophobic/hydrophilic potential were run in parallel in a lab-scale MBR under the same conditions. Membranes were sampled after 1, 10, 20 and 30 days of MBR operation with synthetic wastewater. Subsequently, accumulated organic foulants were characterised using several chemical analytical tools. Results showed similar development of organic foulants with time, illustrating that membrane surface chemistry did not affect the selection of specific organic foulants. Multivariate analysis showed that biofilm samples clustered according to the day of sampling. The composition of organic foulants shifted from protein-like substances towards humics and polysaccharides-like substances. We propose that to control biofouling in MBRs, one should focus less on the membrane surface chemistry.

  20. Geographic variability in organic carbon stock and accumulation rate in sediments of East and Southeast Asian seagrass meadows

    Miyajima, Toshihiro; Hori, Masakazu; Hamaguchi, Masami; Shimabukuro, Hiromori; Adachi, Hiroshi; Yamano, Hiroya; Nakaoka, Masahiro

    2015-04-01

    Organic carbon (OC) stored in the sediments of seagrass meadows has been considered a globally significant OC reservoir. However, the sparsity and regional bias of studies on long-term OC accumulation in coastal sediments have limited reliable estimation of the capacity of seagrass meadows as a global OC sink. We evaluated the amount and accumulation rate of OC in sediment of seagrass meadows and adjacent areas in East and Southeast Asia. In temperate sites, the average OC concentration in the top 30 cm of sediment was higher in seagrass meadows (780-1080 mmol g-1) than in sediments without seagrass cover (52-430 mmol g-1). The average OC in the top 30 cm of subtropical and tropical seagrass meadow sediments ranged from 140 to 440 mmol g-1. Carbon isotope mass balancing suggested that the contribution of seagrass-derived carbon to OC stored in sediments was often relatively minor (temperate: 10-40%; subtropical: 35-82%; tropical: 4-34%) and correlated to the habitat type, being particularly low in estuarine habitats. Stock of OC in the top meter of sediment of all the studied meadows ranged from 38 to 120 Mg ha-1. The sediment accumulation rates were estimated by radiocarbon dating of six selected cores (0.32-1.34 mm yr-1). The long-term OC accumulation rates calculated from the sediment accumulation rate and the top 30 cm average OC concentration for the seagrass meadows (24-101 kg ha-1 yr-1) were considerably lower than the OC accumulation rates previously reported for Mediterranean Posidonia oceanica meadows (580 kg ha-1 yr-1 on average). Current estimates for the global carbon sink capacity of seagrass meadows, which rely largely on Mediterranean studies, may be considerable overestimations.

  1. Accumulation of polychlorinated organic contaminants from sediment by three benthic marine species

    Pruell, R.J.; Rubinstein, N.I.; Taplin, B.K.; LiVolsi, J.A.; Bowen, R.D.

    1993-01-01

    A laboratory experiment was conducted to measure the accumulation of selected polychlorinated compounds by marine benthos exposed to environmentally contaminated sediment. Sandworms (Nereis virens), clams (Macoma nasuta), and grass shrimp (Palaemonetes pugio) were exposed to sediment collected from the Passaic River, New Jersey. All three species accumulated 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD), 2,3,7,8-tetrachlorodibenzofuran (2,3,7,8-TCDF) and polychlorinated biphenyls (PCBs) from the sediment. In addition, a recently identified sulfur containing analog of tetrachlorinated dibenzofurans. The objectives of the study were to determine the relative bioavailability of 2,3,7,8-TCDD, 2,3,7,8-tetrachlorodibenzofuran (2,3,7,8-TCDF) and selected PCB congeners from bottom sediments as well as to examine the relationship between contaminant concentrations in sediments and biota.

  2. Molecular Characterization of PauR and Its Role in Control of Putrescine and Cadaverine Catabolism through the γ-Glutamylation Pathway in Pseudomonas aeruginosa PAO1

    Chou, Han Ting; Li, Jeng-Yi; Peng, Yu-Chih; Lu, Chung-Dar

    2013-01-01

    Pseudomonas aeruginosa PAO1 grows on a variety of polyamines as the sole source of carbon and nitrogen. Catabolism of polyamines is mediated by the γ-glutamylation pathway, which is complicated by the existence of multiple homologous enzymes with redundant specificities toward different polyamines for a more diverse metabolic capacity in this organism. Through a series of markerless gene knockout mutants and complementation tests, specific combinations of pauABCD (polyamine utilization) genes...

  3. ACCUMULATION OF CHEMICAL ELEMENTS BY ORGANS OF SPARGANIUM ERECTUM L. AND THEIR POTENTIAL USE IN PHYTOREMEDIATION PROCESS

    Agnieszka Edyta Parzych

    2016-01-01

    Full Text Available The study of bottom sediments and organs of Sparganium erectum carried out in the summer of 2014 in the city of Lębork, located in Northern Poland. The aim of this study was to evaluate the content of macroelements and heavy metals in the leaves, rhizomes and roots S. erectum and in bottom sediments of the Łeba River as well as comparison of accumulation and translocation factors of N, P, K, Mg, Ca, Zn, Ni, Cu, Mn, Fe, Cd and Cr in researched organs of aquatic plant. The use of S. erectum for biomonitoring and phytoremediation has also been considered. The results of Mann Whitney U test showed a number of statistically significant differences in the content of chemical elements in the leaves, rhizomes, roots and in bottom sediments. The macroelements are mainly accumulated in leaves and heavy metals are accumulated in roots and rhizomes of S. erectum. Increased Mn and Fe content in roots and rhizomes of S. erectum, in relation this physiological needs, refers to the beneficial effects of this species in the water treatment and sludge from the bottom sediment of manganese and iron compounds. The obtained bioconcentration and translocation factors values allowed to state that S. erectum can be used for phytoremediation of contaminated bottom sediments because retains metals in their roots and limit Mn and Fe mobility from roots and rhizomes to leaves once absorbed by roots of plant.

  4. Hydrocortisone and Vitamin D3 stimulation of 32Psub(i)-phosphate accumulation by organ-cultured chick embryo duodenum

    Either vitamin D3 (or 1 α,25-(OH)2-D3) or hydrocortisone (HC) stimulated phosphate accumulation by organ-cultured embryonic chick duodenum. In combination, these two steroids stimulated phosphate uptake synergistically. Phosphate accumulation appeared to be independent of other vitamin D3-stimulated processes: CaBP concentration, cAMP concentration, or alkaline phosphataseactivity. L-phenylalanine, a reported alkaline phosphate inhibitor, when added to the culture medium progressively inhibited either D3- or HC-stimulated phosphate uptake subsequent to culture, but did not inhibit the synergistic action under these conditions L-phenylalanine had no consistent effect on alkaline phosphotase activity but unexpectedly, greatly inhibited vitamin D3 - stimulated CaBP concentration, but only in the absence of HC. Some limited suggestion of an intestinal phosphoprotein sensitve to either vitamin D3 or HC was observed. (orig.)

  5. 99mTc HM-PAO brain perfusion SPECT in brain death

    We have easily carried out and interpreted 99mTc HM-PAO SPECT in a consecutive series of 40 comatose patients with brain damage, without discontinuing therapy. Brain death was diagnosed in 7 patients, by recognising absence of brain perfusion, as shown by no intracranial radionuclide uptake. In patients in whom perfusion was seen on brain scans, HM-PAO SPECT improved assessment of the extent of injury, which in general was larger than suggested by CT. (orig.)

  6. 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 ...

  7. Fructooligosacharides reduce Pseudomonas aeruginosa PAO1 pathogenicity through distinct mechanisms.

    Mercedes Ortega-González

    Full Text Available Pseudomonas aeruginosa is ubiquitously present in the environment and acts as an opportunistic pathogen on humans, animals and plants. We report here the effects of the prebiotic polysaccharide inulin and its hydrolysed form FOS on this bacterium. FOS was found to inhibit bacterial growth of strain PAO1, while inulin did not affect growth rate or yield in a significant manner. Inulin stimulated biofilm formation, whereas a dramatic reduction of the biofilm formation was observed in the presence of FOS. Similar opposing effects were observed for bacterial motility, where FOS inhibited the swarming and twitching behaviour whereas inulin caused its stimulation. In co-cultures with eukaryotic cells (macrophages FOS and, to a lesser extent, inulin reduced the secretion of the inflammatory cytokines IL-6, IL-10 and TNF-α. Western blot experiments indicated that the effects mediated by FOS in macrophages are associated with a decreased activation of the NF-κB pathway. Since FOS and inulin stimulate pathway activation in the absence of bacteria, the FOS mediated effect is likely to be of indirect nature, such as via a reduction of bacterial virulence. Further, this modulatory effect is observed also with the highly virulent ptxS mutated strain. Co-culture experiments of P. aeruginosa with IEC18 eukaryotic cells showed that FOS reduces the concentration of the major virulence factor, exotoxin A, suggesting that this is a possible mechanism for the reduction of pathogenicity. The potential of these compounds as components of antibacterial and anti-inflammatory cocktails is discussed.

  8. Fructooligosacharides reduce Pseudomonas aeruginosa PAO1 pathogenicity through distinct mechanisms.

    Ortega-González, Mercedes; Sánchez de Medina, Fermín; Molina-Santiago, Carlos; López-Posadas, Rocío; Pacheco, Daniel; Krell, Tino; Martínez-Augustin, Olga; Abdelali, Daddaoua

    2014-01-01

    Pseudomonas aeruginosa is ubiquitously present in the environment and acts as an opportunistic pathogen on humans, animals and plants. We report here the effects of the prebiotic polysaccharide inulin and its hydrolysed form FOS on this bacterium. FOS was found to inhibit bacterial growth of strain PAO1, while inulin did not affect growth rate or yield in a significant manner. Inulin stimulated biofilm formation, whereas a dramatic reduction of the biofilm formation was observed in the presence of FOS. Similar opposing effects were observed for bacterial motility, where FOS inhibited the swarming and twitching behaviour whereas inulin caused its stimulation. In co-cultures with eukaryotic cells (macrophages) FOS and, to a lesser extent, inulin reduced the secretion of the inflammatory cytokines IL-6, IL-10 and TNF-α. Western blot experiments indicated that the effects mediated by FOS in macrophages are associated with a decreased activation of the NF-κB pathway. Since FOS and inulin stimulate pathway activation in the absence of bacteria, the FOS mediated effect is likely to be of indirect nature, such as via a reduction of bacterial virulence. Further, this modulatory effect is observed also with the highly virulent ptxS mutated strain. Co-culture experiments of P. aeruginosa with IEC18 eukaryotic cells showed that FOS reduces the concentration of the major virulence factor, exotoxin A, suggesting that this is a possible mechanism for the reduction of pathogenicity. The potential of these compounds as components of antibacterial and anti-inflammatory cocktails is discussed. PMID:24465697

  9. Methods for detection and visualization of intracellular polymers stored by polyphosphate-accumulating microorganisms.

    Serafim, Luísa S; Lemos, Paulo C; Levantesi, Caterina; Tandoi, Valter; Santos, Helena; Reis, Maria A M

    2002-09-01

    Polyphosphate-accumulating microorganisms (PAOs) are important in enhanced biological phosphorus (P) removal. Considerable effort has been devoted to understanding the biochemical nature of enhanced biological phosphorus removal (EBPR) and it has been shown that intracellular polymer storage plays an important role in PAO's metabolism. The storage capacity of PAOs gives them a competitive advantage over other microorganisms present that are not able to accumulate internal reserves. Intracellular polymers stored by PAOs include polyphosphate (poly-P), polyhydroxyalkanoates (PHAs) and glycogen. Staining procedures for qualitative visualization of polymers by optical microscopy and combinations of these procedures with molecular tools for in situ identification are described here. The strengths and weaknesses of widely used polymer quantification methods that require destruction of samples, are also discussed. Finally, the potential of in vivo nuclear magnetic resonance (NMR) spectroscopy for on-line measurement of intracellular reserves is reported. PMID:12069885

  10. 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

  11. Tetrodotoxin – Distribution and Accumulation in Aquatic Organisms, and Cases of Human Intoxication

    Osamu Arakawa

    2008-05-01

    Full Text Available Many pufferfish of the family Tetraodontidae possess a potent neurotoxin, tetrodotoxin (TTX. In marine pufferfish species, toxicity is generally high in the liver and ovary, whereas in brackish water and freshwater species, toxicity is higher in the skin. In 1964, the toxin of the California newt was identified as TTX as well, and since then TTX has been detected in a variety of other organisms. TTX is produced primarily by marine bacteria, and pufferfish accumulate TTX via the food chain that begins with these bacteria. Consequently, pufferfish become non-toxic when they are fed TTX-free diets in an environment in which the invasion of TTX-bearing organisms is completely shut off. Although some researchers claim that the TTX of amphibians is endogenous, we believe that it also has an exogenous origin, i.e., from organisms consumed as food. TTX-bearing animals are equipped with a high tolerance to TTX, and thus retain or accumulate TTX possibly as a biologic defense substance. There have been many cases of human intoxication due to the ingestion of TTX-bearing pufferfish, mainly in Japan, China, and Taiwan, and several victims have died. Several cases of TTX intoxication due to the ingestion of small gastropods, including some lethal cases, were recently reported in China and Taiwan, revealing a serious public health issue.

  12. The Accumulation of Organic Carbon in Mineral Soils by Afforestation of Abandoned Farmland

    Wei, Xiaorong; Qiu, Liping; Shao, Mingan; Zhang, Xingchang; Gale, William J.

    2012-01-01

    The afforestation of abandoned farmland significantly influences soil organic carbon (OC). However, the dynamics between OC inputs after afforestation and the original OC are not well understood. To learn more about soil OC dynamics after afforestation of farmland, we measured the soil OC content in paired forest and farmland plots in Shaanxi Province, China. The forest plots had been established on farmland 18, 24, 48, 100, and 200 yr previously. The natural 13C abundance of soil organic mat...

  13. Endocrine activity of persistent organic pollutants accumulated in human silicone implants — Dosing in vitro assays by partitioning from silicone

    Gilbert, Dorothea; Mayer, Philipp; Pedersen, Mikael; Vinggaard, Anne Marie

    2015-01-01

    Persistent organic pollutants (POPs) accumulated in human tissues may pose a risk for human health by interfering with the endocrine system. This study establishes a new link between actual human internal POP levels and the endocrine active dose in vitro, applying partitioning-controlled dosing...... increases in progestagen and corticosteroid levels at Cfree of individual POPs in or below the femtomolar range. Silicone acted not only as source of the POPs but also as a sorption sink for lipophilic hormones, stimulating the cellular hormone production. Methodologically, the study showed that silicone...

  14. Organochlorine pesticides accumulated by SPMD-based virtual organisms and feral fish in Three Gorges Reservoir, China

    Organochlorine pesticides (OCPs) accumulated by semipermeable membrane device (SPMD) -based virtual organisms (VOs) and local feral fish were studied in Three Gorges Reservoir (TGR), China. VOs were deployed at seven sites in TGR for two periods in 2009 and 5 species of fish with different living habitats and feeding habits collected in the same periods from two counties in TGR. 28 OCPs were analyzed and the concentration and profile of OCPs in fish were quite different from those in VOs. The lipid-based concentrations of OCPs in fish ranged from 225.7 ng/g lw to 1996.4 ng/g lw which were much higher than those in VOs which ranged from 17.3 to 112.4 ng/g lw. Dichlorodiphenyltrichloroethanes (DDTs) were the prevalent OCPs in the investigated fish, while hexachlorobenzene (HCB) was the dominant compound in VOs. DDT in the few fish sample analyzed was not of concern based on chemical contaminant limits of non-carcinogenic effect. - Highlights: • OCPs contamination in fish was investigated in Three Gorges Reservoir, China. • Comparison of OCPs accumulation was conducted in feral fish and VOs in TGR. • Composition of OCPs in feral fish was significantly different from that in VOs. • DDTs were the prevalent OCPs in fish and were mainly originated from historical usage. - Comparison of OCPs accumulation was conducted in feral fish and VOs in TGR

  15. Production of polyhydroxyalkanoates from fermented sugar cane molasses by a mixed culture enriched in glycogen accumulating organisms.

    Bengtsson, Simon; Pisco, Ana R; Reis, Maria A M; Lemos, Paulo C

    2010-02-01

    Batch production of polyhydroxyalkanoates (PHAs) under aerobic conditions by an open mixed culture enriched in glycogen accumulating organisms (GAOs) with fermented sugar cane molasses as substrate was studied. The produced polymers contained five types of monomers, namely 3-hydroxybutyrate (3HB), 3-hydroxyvalerate (3HV), 3-hydroxy-2-methylbutyrate (3H2MB), 3-hydroxy-2-methylvalerate (3H2MV) and the medium chain length monomer 3-hydroxyhexanoate (3HHx). With fermented molasses as substrate, PHA was produced under concurrent consumption of stored glycogen with yields of 0.47-0.66 C-mol PHA per C-mol of total carbon substrate and with rates up to 0.65 C-mol/C-molX h. In order to investigate the role of glycogen during aerobic PHA accumulation in GAOs, synthetic single volatile fatty acids (VFAs) were used as substrates and it was found that the fate of glycogen was dependent on the type of VFA being consumed. Aerobic PHA accumulation occurred under concurrent glycogen consumption with acetate as substrate and under minor concurrent glycogen production with propionate as substrate. With butyrate and valerate as substrates, PHA accumulation occurred with the glycogen pool unaffected. The composition of the PHA was dependent on the VFA composition of the fermented molasses and was 56-70 mol-% 3HB, 13-43 mol-% 3HV, 1-23 mol-% 3HHx and 0-2 mol-% 3H2MB and 3H2MV. The high polymer yields and production rates suggest that enrichment of GAOs can be a fruitful strategy for mixed culture production of PHA from waste substrates. PMID:19958801

  16. Accumulation of heavy metals in edible organs of different meat products available in the markets of lahore, pakistan

    The present study assessed the accumulation of selected heavy metals (Cd, Cr, Pb and Cu) indifferent organs including brain, heart, lungs, liver, stomach, kidney and flesh (muscles) of several animals commercially available in the market of Lahore, Pakistan. The concentrations found in different organs of chicken, goat and cow ranged between 0.132-2.165 mg/g for Cd, 0.768-2.335 mg/g for Cr, 0.260-1.411 mg/g for Pb and 0.092-1.195 mg/g for Cu. In the absence of national safety standards in respect to the content of heavy metals in foodstuffs, the results obtained were compared with international guidelines and found concentrations considerably higher than the prescribed safe limits. Therefore, immediate attention must be paid to prevent public health risks associated with the presence of toxic heavy metals in the commercially available meat products. (author)

  17. Renal accumulation of [{sup 111}In]DOTATOC in rats: influence of inhibitors of the organic ion transport and diuretics

    Stahl, A.R. [Technische Universitaet Muenchen, Klinikum rechts der Isar, Department of Nuclear Medicine, Munich (Germany); Universitaetsklinikum Essen, Department of Radiology, Essen (Germany); Wagner, B.; Heemann, U.; Lutz, J. [Technische Universitaet Muenchen, Klinikum rechts der Isar, Department of Nephrology, Munich (Germany); Poethko, T.; Perutka, M.; Wester, H.J.; Essler, M.; Schwaiger, M. [Technische Universitaet Muenchen, Klinikum rechts der Isar, Department of Nuclear Medicine, Munich (Germany)

    2007-12-15

    Radiation exposure to the kidney limits therapy with radiometal labelled DOTATOC. This study evaluates the organic anion and cation transport (inhibitors: probenecid and cimetidine/dexamethason) as well as diuresis (furosemide and mannitol) regarding renal uptake of [{sup 111}In]DOTATOC. One hundred eight male Fisher rats were injected with [{sup 111}In]DOTATOC via the tail vein. Prior to activity injection a total of 84 rats underwent injection with probenecid vs. sodium chloride 0.9% (48 rats), cimetidine vs. dexamethasone vs. sodium chloride 0.9% (18 rats), and furosemide vs. mannitol vs. sodium chloride 0.9% (18 rats). Rats were sacrificed at predetermined time points up to 48 h after activity injection. Kidneys, adrenal glands, pancreas, spleen, blood, liver, and muscle were harvested and injected activity per gram tissue was determined. Autoradiographic images of the kidneys were acquired in a total of 24 rats. Probenecid led to a reduction in renal uptake by up to 30% while not significantly changing the activity accumulation in the other organs investigated. This reduction was attributable to the renal cortex (ratio cortex/medulla 1.72 vs. 1.99; p = 0.006). Cimetidine and dexamethasone had no effect in any of the organs. Furosemide led to a 44% increase in renal activity accumulation attributable to enhanced renal medullary uptake (ratio cortex/medulla 1.44 versus 1.69; p = 0.006). Mannitol had no effect on renal activity uptake. Inhibition of the organic anion transport by probenecid may help reduce renal uptake regarding therapy with radiometal labelled DOTATOC. The enhancing effect of furosemide may be unfavourable for therapy. The results must be confirmed by human studies. (orig.)

  18. Characteristics of radionuclide accumulation in benthic organisms and fish of the Barents and Kara Seas

    Artificial radionuclides play a specific role in the hydrochemical, geochemical, and hydrobiological processes that are currently occurring in the western Arctic. The existing data on radioactive contamination of different plant and animal species inhabiting the sea shelf are fragmentary. Hence, it was difficult to follow the transformation of radionuclides during their transmission along food chains, from phyto- and zoo-plankton to benthos, fish, birds, and marine mammals. In 1990-1994, the Murmansk Institute of Marine Biology organized expeditions to collect samples of residues on the sea floor and also of benthos, benthic fish, macrophytes, and other organisms inhabiting the shelf of the Barents and Kara Seas. These samples were tested for cesium-137, cesium-134, strontium-90, plutonium-239, plutonium-240, americium-241, and cobalt-60 in Rovaniemi (Finland) by the regional radiation administration of the Finnish Centre for Radiation and Nuclear Safety. Over 1000 tests were made. Their results provided new data on the content and distribution of these radionuclides among different components of marine ecosystems. 7 refs

  19. Synthesis of the d,I-HM-PAO and formulation of nucleo-equipment for the obtention of {sup 99m} Tc-(d,I)-HM-PAO; Sintesis del d,I-HM-PAO y formulacion de nucleo-equipos para la obtencion de {sup 99m} Tc-(d,I)-HM-PAO

    Lezama C, J.; Ferro F, G.; Alcazar A, P

    1991-09-15

    Most brain imaging radiopharmaceuticals are conventional hydrophilic compounds that are excluded from entering the normal brain by an intact blood-brain barrier (BBB). Under pathologic conditions, the barrier is disrupted and radiotracer concentrates in the leisure for positive identification. {sup 99m} Tc- hexa methyl propylene amine oxime ({sup 99} {sup m} Tc-HM-PAO) is a newer-type lipophilic agent that enter the normal brain through an intact BBB. Studies with this agent offer the promise of measuring cerebral perfusion in the normal and diseased brain. In this paper we present the synthesis and Tc-99m labelling of d,I-HM-PAO. The synthesis of the ligand was carried out by condensation of two molecular equivalents of butanedione monoxime with one molecular equivalent of 1,3 propanediamine provided a bis imine intermediate, which was reduced with sodium borohydride to get the meso and d,I diastereoisomers of HM-PAO. Separation of these was achieved by fractional crystallization. {sup 99m} Tc-(d,I)HM-PAO was obtained by stannous ion reduction of Mo-99/Tc-99m generator eluate in the presence of the ligand. Complex radiochemical purity was determined by instant thin layer chromatography and paper chromatography. Finally, we obtained {sup 99m} Tc-(d,I)HM-PAO with a high radiochemical yield, in excess of 90%. However, for subsequent clinical studies the preparation has to be done a few minutes before application because our product has a low stability. (Author)

  20. Emulsion and accumulation at aqueous/organic interface of mixer-settlers

    The emulsion which results from Di-n-butylphosphoric acid (HDBP) and zirconium (HDBP-Zr emulsion) was studied on the formation ratio to the emulsion of nonsoluble fission product residues (nonsoluble residues emulsion) in the codecontamination cycle without solvent washing. HDBP-Zr emulsion was found three times of nonsoluble residues emulsion by one week's operation of the codecontamination cycle with the spent nuclear fuel burnt to 28,000 MWd/MTU and cooled 1,000 days. In this codecontamination cycle, 1% HDBP was salted out at the aqueous/organic interface as HDBP-Zr emulsion, and 10% HDBP dissolved in the recycling solvent stream as HDBP-U complex. It was found that HDBP-Zr emulsion accelerates the volume growth of nonsoluble residues emulsion by the emulsifying effect. (author)

  1. Accumulated organic matter, litterfall production, and decomposition tell us the status of litter dynamics in forests

    Jae Geun Kim

    2012-06-01

    Full Text Available Litterfall dynamics in forests are assessed by estimating biomass production and decomposition. However, there havebeen few studies on how litter dynamics impact the health and management of ecosystems. Here, a new approach tomeasure and assess ecosystem function is presented based on conventional methods using littertraps, litterbags, andthe mass on the forest floor. To assess the status of litter dynamics, the decay rate (k was estimated from a litterbag experiment,and removal rates (ki were determined from mass balance on the forest floor at 21 sites on three mountainsin South Korea. The k3 (organic mass ratio of Oi and Oe + Oa + A horizons in November values in an equilibrium state inSouth Korea were within the range of k ± 0.174 when considering the annual variation of litterfall production. This studyalso suggests that sampling sites for these types of studies should be in the middle, not at the ends, of steady slopes onthe forest floor.

  2. 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

  3. 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.

  4. 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).

  5. Denitrification characteristics and community distribution of glycogen accumulating organism granules%聚糖菌颗粒污泥的反硝化特性与微生物群落分布

    张斌; 邱志刚; 薛斌; 谌志强; 龚泰石; 王雪; 智维佳; 王景峰

    2014-01-01

    This study aimed to investigate the denitrification ability and microbial ecological characteristic of glycogen-accumulating organisms (GAOs) during sludge granulation.A combined method of reactor process,batch test,microscale techniques and fluorescence in situ hybridization (FISH) was employed to evaluate the denitrification ability of GAOs,to reveal the microstructure of microbial communities and to characterize the distribution of GAOs and polyphosphate-accumulating organisms (PAOs) in different size granules.The results indicated that the adsorption rate of organic compound by sludge was over 92%.The SVI10 of granules stabilized at 30-50 mL g-1,a very low value compared to those measured for inoculating sludge (108.2 mL g-1).The nitrogen removal rate of nitrate and nitrite by GAOs granules reached 65% and 70% respectively,with N2 as the main gaseous product.The granules were tightly packed with a large amount of tetrad-forming organisms (TFOs),with filamentous bacteria serving as the supporting structures for the granules.FISH demonstrated that GAOs were distributed evenly throughout the granular space,whereas PAOs were severely inhibited and presented only in the edge of granules.A labscale sequencing batch reactor (SBR) could be successfully operated for cultivating GAOs granules in alternating anaerobic stirring-discharge-aerobic modes,with the GAOs granules showing excellent denitrifying capability.Therefore GAOs are the predominant member of the microbial population in granules.%为了解聚糖菌在污泥颗粒化中的脱氮能力及其微生物生态特性,采用反应器工艺、批式试验、显微技术和荧光原位杂交技术来评估其反硝化能力,揭示其微生物群落的微观结构,探索聚糖菌和聚磷菌在不同粒径污泥中的分布特征.结果表明,污泥对有机物的吸收率稳定在90%以上.颗粒污泥的沉降指数(SVI10)稳定在30-50 mL g-1,远低于接种污泥的108.2 mL g-1.聚醣菌颗粒污泥对

  6. Effect of soil moisture on sulphur accumulation in overground plant organs and their harm in emmission conditions

    Navara, J.; Horvath, I.; Hauskrecht, I.

    1972-01-01

    The effect of different soil moisture on sulphur accumulation in the overground organs of Fagopyrum esculentum, moench in immission conditions is dealt with in this paper. The results obtained have shown that even under equal soil conditions, equal nutrient supply and age evenness of the analyzed material the total sulphur content of leaves grown in immission conditions (sulphur oxides, hydrogen sulphide, carbon disulphide, etc.) at equal soil moisture was essentially higher when compared with unirrigated plants and corresponded also to the degree of harm and crop reduction of the experimental plants. Therefore it is necessary when utilizing sulphur content of indicating plants, which serves for a large-area diagnosis of vegetation harm with immissions, to take into consideration, in addition to other factors (soil, nutrition, age of plants), the soil moisture as well.

  7. Sedimentological Records of Organic Matter Accumulation in the Inshore Region of the Fly River Clinoform (Papua New Guinea)

    Gisewhite, R.; Goni, M. A.; Clinton, R.; Monacci, N.; McKay, M.; Crockett, J.; Nittrouer, C.

    2004-12-01

    Thirteen kasten cores collected from the northeast and southwest regions of the clinoform topset off the Fly River Delta and from the Umuda Channel were selected for elemental (organic carbon, nitrogen), mineral surface area (SA), stable isotope (d13C and d15N) and biomarker (lignin phenols) analyses. The depth of the cores ranged from 30 to over 250 cm and represent variable periods of depositional history. The average organic carbon content (OC) of sediments ranged from 0.6 to 2 wt. percent, depending on the site location. The highest OC levels were observed in the northeast region off the Fly River Delta, while the lowest levels were found in cores located in the southern offshore region. Average molar organic carbon:nitrogen ratios ranged from 10 to 18, with the lowest C/N ratios found in the sites located to the south of the delta. Average d13C and nitrogen d15N signatures ranged from -26 to -25 per mil and from 1.4 to 2.5 per mil, respectively. Average OC/SA ratios for the sediments in these cores ranged from 0.4 to 1.7 mg C/m2, with the lowest values measured in samples from the Umuda Channel and the most distal site in the northeast region of the topset. Overall, these compositions indicate organic matter accumulation in all these sites is dominated by the burial of terrigenous derived soil organic matter. Down core peaks in C/N and OC/SA ratios indicate the presence of discrete layers enriched in vascular plant detritus. Low OC/SA ratios indicative of extensive decay were only measured in selected sites and in specific horizons. In contrast, most samples were characterized by "normal" organic carbon loadings that are consistent with the active burial and effective preservation of terrigenous organic matter in this region of the Fly River Delta and clinoform. There is little evidence for the preservation of marine-derived organic matter in these deposits. These data will be further interpreted in the context of additional sedimentological data (X

  8. Trace element accumulation and trophic relationships in aquatic organisms of the Sundarbans mangrove ecosystem (Bangladesh).

    Borrell, Asunción; Tornero, Victoria; Bhattacharjee, Dola; Aguilar, Alex

    2016-03-01

    The Sundarbans forest is the largest and one of the most diverse and productive mangrove ecosystems in the world. Located at the northern shoreline of the Bay of Bengal in the Indian Ocean and straddling India and Bangladesh, the mangrove forest is the result of three primary river systems that originate further north and northwest. During recent decades, the Sundarbans have been subject to increasing pollution by trace elements caused by the progressive industrialization and urbanization of the basins of these three rivers. As a consequence, animals and plants dwelling downstream in the mangroves are exposed to these pollutants in varying degrees, and may potentially affect human health when consumed. The aim of the present study was to analyse the concentrations of seven trace elements (Zn, Cu, Cr, Hg, Pb, Cd and As) in 14 different animal and plant species collected in the Sundarbans in Bangladesh to study their transfer through the food web and to determine whether their levels in edible species are acceptable for human consumption. δ(15)N values were used as a proxy of the trophic level. A decrease in Zn, Cu, Pb and Cd levels was observed with increasing trophic position. Trace element concentrations measured in all organisms were, in general, lower than the concentrations obtained in other field studies conducted in the same region. When examined with respect to accepted international standards, the concentrations observed in fish and crustaceans were generally found to be safe for human consumption. However, the levels of Zn in Scylla serrata and Cr and Cd in Harpadon nehereus exceeded the proposed health advisory levels and may be of concern for human health. PMID:26748006

  9. Drainage, liming and fertilization of organic soils. 2. Distribution of macro elements and heavy-metal accumulation

    Mobility, exchangeability and accumulation of macro elements and heavy metals after liming and fertilization of organic soils were studied on three sites, two oligotrophic and one mesotrophic. These were drained, fertilized and/or limed in 1953-1956 and sampled in 1991-1992. Fertilization and liming caused marginal changes in bulk density, N stores and C/N ratios, while percentage ash content increased significantly to 40 cm depth at the two oligotrophic sites and to 10 cm at the mesotrophic site. Applied P was relatively immobile and liming caused more P to accumulate in the surface layer, whereas applied K and Mg were mobile with elevated concentrations being measured to 60 cm depth at the oligotrophic sites. Even if liming reduced the relative exchangeable pools of Fe and Al these elements moved to this depth after combined fertilization and liming, but mobility was less after liming alone. Relative exchangeable pools of K, Ca and Mg were high, of Fe and Al intermediate to low and of S and P low. The relative exchangeable P pools were site and treatment specific. The 'old P pool' of organic soils seemed quite stable and strongly fixed, while the 'new P pool' from fertilizer P probably had higher exchange ratio. Increased stores of Cr, Ni, Sr and Ti resulted from impurities in both fertilizer and lime, Cu from the compound fertilizer, and V and Y probably from the P fertilizer. Stores of Pb were not significantly changed by the treatments; those of Zn was unchanged after liming or even reduced after combined fertilization and liming. The Cu and Pb concentrations were sometimes above the suggested critical levels of toxicity 24 refs, 3 figs, 11 tabs

  10. Carbon storage in Organic Soils (COrS): Quantifying past variations in carbon accumulation in peatlands of South Wales, UK.

    Carless, Donna; Kulessa, Bernd; Street-Perrott, Alayne; Davies, Siwan; Sinnadurai, Paul

    2014-05-01

    Globally, peatlands comprise a vital terrestrial carbon sink, currently estimated to be around 500 PgC (Yu et al., 2011, Gorham, 1991). Within the UK, peatlands represent the single most important terrestrial carbon store (IUCN, 2011). In particular, blanket and raised bogs account for around 23,000 square kilometres or 9.5 percent of the UK land area, with current estimates indicating that they store approximately 3.2 PgC (IUCN, 2011). Recent studies suggest that carbon-sequestration rates have been highly variable during the Holocene (Frolking & Roulet, 2007). Reconstructing these past fluctuations is essential to assess how peatlands will respond to future climate change, particularly the possibility that large amounts of respired below-ground carbon will be released as a result of enhanced rates of decomposition, causing positive climate feedback. Quantitative estimates of past variations in carbon accumulation provide valuable insights into the factors controlling carbon budgets. Recent developments have illustrated how ground-penetrating radar (GPR) can improve constraints on peat thickness (Holden et al., 2002, Warner et al., 1990), facilitating site-specific peat-volume estimates for carbon quantification. We shall present initial results from the COrS project, which brings together a novel combination of geophysical and proxy techniques to reconstruct variations in long-term carbon accumulation in 6 ombrotrophic peat bogs, located across the Brecon Beacons National Park (BBNP), South Wales, UK (51°55'30" N, 3°29'18" W). Detailed GPR surveys are being used to provide comprehensive estimates of total peat extent and thickness at these sites. Combined with surface-elevation data from LiDAR imagery, 3D models are being created, from which total peat-volume estimates will be extracted. Carbon-accumulation rates will be inferred from these bog-volume estimates, coupled with total organic carbon (TOC) measurements and high-resolution radiocarbon dating. In

  11. Distribution of inorganic and organic nutrients in the South Pacific Ocean – evidence for long-term accumulation of organic matter in nitrogen-depleted waters

    F. Cerutti

    2007-08-01

    were two fold higher. Extensive comparison has shown that glass fiber GF/F filters efficiency collected particulate chlorophyll, while a significant fraction of POM (up to 50% passed trough this filter and was retained by 0.2 μm Teflon membrane. The most striking feature was the large accumulation of dissolved organic matter (DOM in the SPG relative to surrounding waters, especially dissolved organic carbon (DOC where concentrations were at levels rarely measured in oceanic waters (>100 μmoles l−1. Due to this large pool of DOM over the whole photic layer of the SPG, integrated values followed an opposite geographical pattern than this of inorganic nutrients with a large accumulation within the centre of the SPG. While suspended particulate matter in the mixed layer had C/N ratio largely conform to Redfield stoichiometry (C/N≈6.6, marked deviations were observed in this excess DOM (C/N≈16 to 23. The existence of C-rich dissolved organic matter is recognized as a feature typical of oligotrophic waters, requiring the over consumption of carbon. Thus, in spite of strong nitrate-depletion leading to low chlorophyll biomass, the closed ecosystem of the SPG can produce a large amount of carbon. The implications of this finding are discussed, the conclusion being that, due to the lack of seasonal vertical mixing and weak lateral advection, the dissolved organic carbon biologically produced can be accumulated and stored in the photic layer for a very long period.

  12. Study of the influence of ionizing radiation on the dynamics of accumulation of anthocyanins, flavonoids and carotenoids in individual organs of Alhagi Pseudalhagi

    Full text : It is known that the formation and accumulation of biologically active substances is a dynamic process. Their content varies in ontogeny plants and depending on environmental factors. In the present work it is studied the dynamics of accumulation of anthocyanins, flavonoids and carotenoids in certain organs of the plant in the budding phase. On the ability to accumulate flavonoids second place is occupied by the stem and flowers of the plant. In a certain amount of flavonoids are presented in plant seeds. In this case the roots of the plant show the least ability for accumulation of flavonoids. Regarding the role of radiation in the process, it should be noted that it plays a minor role in accumulation of flavonoids

  13. Implications of fire-mediated changes in larch forest structure on leaf litter inputs, organic layer accumulation, and permafrost dynamics

    Ganzlin, P.; Alexander, H. D.; Petronio, B.; Natali, S.; Davydov, S.

    2012-12-01

    and moss inhibition. These data suggest that if forest densities increase due to shifting fire regimes, leaf litter inputs would increase, reducing moss and organic layer development. In turn, belowground carbon accumulation would decline and promote greater availability of permafrost carbon to degradation. This degradation holds large potential as a positive feedback to global climate change.

  14. The retention of [99mTc]-d,l-HM-PAO in the human brain after intracarotid bolus injection

    Lassen, N A; Andersen, A R; Friberg, L; Paulson, O B

    1988-01-01

    . Cerebral blood flow (F) was measured using the xenon-133 intracarotid injection method. The first-pass extraction E of HM-PAO was calculated from F using an empiric regression equation. The residue curves for the whole brain after intracarotid HM-PAO injection were analyzed to yield a retention fraction (R...

  15. Regulation of Amidase Formation in Mutants from Pseudomonas aeruginosa PAO Lacking Glutamine Synthetase Activity

    Janssen, Dick B.; Herst, Patricia M.; Joosten, Han M.L.J.; Drift, Chris van der

    1982-01-01

    The formation of amidase was studied in mutants from Pseudomonas aeruginosa PAO lacking glutamine synthetase activity. It appeared that catabolite repression of amidase synthesis by succinate was partially relieved when cellular growth was limited by glutamine. Under these conditions, a correlation

  16. Assessment of persistent organic pollutants accumulation and lipid peroxidation in two reproductive stages of wild silverside (Odontesthes bonariensis).

    Barni, María Florencia Silva; Gonzalez, Mariana; Miglioranza, Karina S B

    2014-01-01

    Persistent organic pollutants (POPs) in streamwater can sometimes exceed the guidelines values reported for biota and human protection in watersheds with intensive agriculture. Oxidative stress and cytotoxicity are some of the markers of exposure to POPs in fish. Accumulation of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) as well as lipid peroxidation (LPO) was assessed in wild silverside (Odontesthes bonariensis) from maturation and pre-spawning stages sampled in a typical soybean growing area. Pollutants were quantified by gas chromatography with electron capture detection and LPO by the method of thiobarbituric acid reactive substances. Concentrations of POPs were in the following order: OCPs>PCBs>PBDEs in all organs and stages. Liver, gills and gonads had the highest OCP concentrations in both sexes and stages with a predominance of endosulfan in all samples. Matured individuals, sampled after endosulfan application period, showed higher endosulfan concentrations than pre-spawning individuals. The predominance of endosulfan sulfate could be due to direct uptake from diet and water column, as well as to the metabolism of the parent compounds in fish. The prevalence of p,p'-DDE in liver would also reflect both the direct uptake and the metabolic transformation of p,p'-DDT to p,p'-DDE by fish. The highest levels of PBDEs and PCBs were found in gills and brain of both stages of growth. The pattern BDE-47>BDE-100 in all samples corresponds to pentaBDE exposure. In the case of PCBs, penta (#101 and 110) and hexa-CB congeners (#153 and 138) dominated in the maturation stages and tri (#18) and tetra-CB (#44 and 52) in pre-spawning stages, suggesting biotransformation or preferential accumulation of heavier congeners during gonadal development. Differences in LPO levels in ovaries were associated with growth dilution and reproductive stage. Differences in LPO levels in gills were related with pesticide

  17. Distribution of inorganic and organic nutrients in the South Pacific Ocean − evidence for long-term accumulation of organic matter in nitrogen-depleted waters

    F. Cerutti

    2008-03-01

    time of particulate carbon in the surface water was only 4–5 days in the upwelling, but up to 30 days in the SPG, where light isotopic δ15N signal noted in the suspended POM suggests that N2-fixation provides a dominant supply of nitrogen to phytoplankton. The most striking feature was the large accumulation of dissolved organic matter (DOM in the SPG compared to the surrounding waters, in particular dissolved organic carbon (DOC where concentrations were at levels rarely measured in oceanic waters (>100 μmoles l−1. Due to this large pool of DOM in the SPG photic layer, integrated values followed a converse geographical pattern to that of inorganic nutrients with a large accumulation in the centre of the SPG. Whereas suspended particulate matter in the mixed layer had a C/N ratio largely conforming to the Redfield stochiometry (C/N≈6.6, marked deviations were observed in this excess DOM (C/N≈16 to 23. The marked geographical trend suggests that a net in situ source exists, mainly due to biological processes. Thus, in spite of strong nitrate-depletion leading to low chlorophyll biomass, the closed ecosystem of the SPG can accumulate large amounts of C-rich dissolved organic matter. The implications of this finding are examined, the conclusion being that, due to weak lateral advection, the biologically produced dissolved organic carbon can be accumulated and stored in the photic layer for very long periods. In spite of the lack of seasonal vertical mixing, a significant part of new production (up to 34%, which was mainly supported by dinitrogen fixation, can be exported to deep waters by turbulent diffusion in terms of DOC. The diffusive rate estimated in the SPG (134 μmolesC m−2 d−1, was quite equivalent to the particles flux measured by sediments traps.

  18. Seasonal changes in metal accumulation and distribution in the organs of Phragmites australis (common reed from Lake Skadar, Montenegro

    Kastratović Vlatko

    2013-01-01

    Full Text Available Due to its ability to accumulate metals, availability throughout the year and its large biomass, Phragmites australis (common reed is suitable for biomonitoring studies for the evaluation of load level of water ecosystem with trace metals. The heavy metals concentration in P.australis tissue can be several ten to several thousand times higher than those in the surrounding water. In this study we examined the content of heavy metals (Cd, Co, Cr, Cu, Mn, Ni, Pb, Zn, Sr and V in sediment, water and different organs of Phragmites australis collected from Lake Skadar, Montenegro, during different seasons of the year 2011. The highest concentrations of Sr were found in the leaves, while the other studied metals showed their highest concentrations in the roots. Thus, P. australis is considered a root bioaccumulation species. For most metals the concentration in roots and stems increases over time until the end of the growing season, and then decreases, while the concentration in leaves increases even after the growing season of the plant. If P. australis is used for phytoremediation purposes, then it should be harvested after the growing season because then the concentration of metals in the aboveground parts is maximal.

  19. Effects of sub-lethal exposure of lead acetate on histopathology of gills, liver, kidney and muscle and its accumulation in these organs of Clarias gariepinus

    Hmoud Fares Alkahem Al-Balawi

    2013-04-01

    Full Text Available The aim of this work was to study the effects of sub-lethal exposure of lead acetate on the histopathology of the gills, liver, kidney and muscle and its accumulation in these organs of Clarias gariepinus. Results showed that lead accumulation in the tissues of C. gariepinus was dependent on the exposure period and lead concentration. Gills and liver were the predominant storage tissue and the order of accumulation in tissues was gill > liver > kidney > muscle. Some structural changes were observed in different organs, especially in the gills of the fishes exposed to lead acetate. Epithelial hypertrophy and epithelial lifting were apparent in the gills of exposed fishes. The degeneration of cytoplasm and secondary lamellae was also observed. Necrosis of hepatocytes was apparent. Glomerular expansion and gaps between the muscular bundles were found in the fishes exposed to lead acetate.

  20. Contrasted accumulation patterns of persistent organic pollutants and mercury in sympatric tropical dolphins from the south-western Indian Ocean.

    Dirtu, Alin C; Malarvannan, Govindan; Das, Krishna; Dulau-Drouot, Violaine; Kiszka, Jeremy J; Lepoint, Gilles; Mongin, Philippe; Covaci, Adrian

    2016-04-01

    Due to their high trophic position and long life span, small cetaceans are considered as suitable bioindicators to monitor the presence of contaminants in marine ecosystems. Here, we document the contamination with persistent organic pollutants (POPs) and total mercury (T-Hg) of spinner (Stenella longirostris, n =21) and Indo-Pacific bottlenose dolphins (Tursiops aduncus, n=32) sampled from the coastal waters of La Réunion (south-western Indian Ocean). In addition, seven co-occurring teleost fish species were sampled and analyzed as well. Blubber samples from living dolphins and muscle from teleosts were analyzed for polychlorinated biphenyls (PCBs), DDT and metabolites (DDTs), chlordanes (CHLs), hexachlorocyclohexanes (HCHs), hexachlorobenzene (HCB), and polybrominated diphenyl ethers (PBDEs). Methoxylated PBDEs (MeO-PBDEs), reported as having a natural origin, were also analyzed. T-Hg levels were measured in blubber and skin biopsies of the two dolphin species. Stable isotopes δ(13)C and δ(15)N values were determined in skin of the dolphins and in the muscle of teleosts. For PCBs, HCHs and T-Hg, concentrations were significantly higher in T. aduncus than in S. longirostris. For other POP levels, intra-species variability was high. MeO-PBDEs were the dominant compounds (55% of the total POPs) in S. longirostris, while PCBs dominated (50% contribution) in T. aduncus. Other contaminants showed similar profiles between the two species. Given the different patterns of POPs and T-Hg contamination and the δ(15)N values observed among analyzed teleosts, dietary and foraging habitat preferences most likely explain the contrasted contaminant profiles observed in the two dolphin species. Levels of each class of contaminants were significantly higher in males than females. Despite their spatial and temporal overlap in the waters of La Réunion, S. longirostris and T. aduncus are differently exposed to contaminant accumulation. PMID:26775007

  1. Cesium accumulation by aquatic organisms at different trophic levels following an experimental release into a small reservoir

    The rates of accumulation and subsequent loss of stable cesium (133Cs) by organisms at different trophic levels within plankton-based and periphyton-based food chains were measured following the addition of 133Cs into a small reservoir near Aiken, South Carolina, USA. An uptake parameter u (L kg-1 d-1 dry mass) and a loss rate parameter k (d-1) were estimated for each organism using time-series measurements of 133Cs concentrations in water and biota, and these parameters were used to estimate maximum concentrations, times to maximum concentrations, and concentration ratios (Cr). The maximum 133Cs concentrations for plankton, periphyton, the insect larva Chaoborus punctipennis, which feeds on plankton, and the snail Helisoma trivolvis, which feeds on periphyton, occurred within the first 14 days following the addition, whereas the maximum concentrations for the fish species Lepomis macrochirus and Micropterus salmoides occurred after 170 days. The Cr based on dry mass for plankton and C. punctipennis were 1220 L kg-1 and 5570 L kg-1, respectively, and were less than the Cr of 8630 L kg-1 for periphyton and 47,700 L kg-1 for H. trivolvis. Although the Cr differed between plankton-based and periphyton-based food chains, they displayed similar levels of biomagnification. Biomagnification was also indicated for fish where the Cr for the mostly nonpiscivorous L. macrochirus of 22,600 L kg-1 was three times less than that for mostly piscivorous M. salmoides of 71,500 L kg-1. Although the Cr for M. salmoides was greater than those for periphyton and H. trivolvis, the maximum 133Cs concentrations for periphyton and H. trivolvis were greater than that for M. salmoides. - Research highlights: → A simple uptake and loss model described the Cs dynamics in all the various biota. → Concentrations of Cs were greater in periphyton than in plankton. → Biota other than fish demonstrated the greatest maximum Cs concentrations. → Concentration ratios were generally consisted

  2. SPET with 99mTc-HM PAO in the study of classic migraine

    Five patients presenting with migraine attacks underwent Electroencephalography (EEC), Computed Tomography (CT) and Single Photon Emission Tomography (SPET) with 99mTc-HM PAO. EEG qand SPET were subsequently repeated in the intercritical period. We observed that two patients only showed non-specific abnormalities in EEG; scans were in all patients; all subjects exhibited diffuse cortical hypoperfusion. A strong correlation was always found between clinical presentation and hemispheric impairment. One patient exhibited asymmetrical perfusion between cerebellum hemispheres; intercritical SPET showed homogeneous distrubution of the radio-tracer in 4 patients. In the last one minimal residual hypoperfusion was observed, although less marked than in the acute phase. Therefore SPET with 99mTc-HM PAO can be reasonably employed as the examination of choice when a migrain attack is clinically suspected, because of its reproducibility and reliability. It can be easily performed in every nuclear medical center supplied with modern tomographic cameras

  3. Clinical applications of brain perfusion imaging with 99mTc-HM-PAO

    200 patients with central nervous system diseases were studied with 99mTc-HM-PAO and SPECT, including Parkinson's disease (PD) 47, Vascular headache 69, CVD 34, Epilepsy 26, Head truma 10, Brain tumor 5 and other 9 cases. Part of them have been compared with the results of MRI, X-CT and EEG. The positivity of SPECT in PD is 61.7% with decrease perfusion in local area of cerebram and basal ganglia and only 4 cases had lower perfusion in cerebellum; in headache is 46.4%, showing variable perfusion patterns; in CVD is 79.4% with decrease perfusion, luxury perfusion and the phenomenon of 'diaschsis'. In epilepsy, the abnormal foci mostly localize in temporal lobe and have close relation to the results of EEG. In brain tumor it also denotes decreased uptake of tracer. The clinicl singnificance of brain perfusion imaging with 99mTc-HM-PAO was discussed

  4. 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.

  5. Group X Aldehyde Dehydrogenases of Pseudomonas aeruginosa PAO1 Degrade Hydrazones

    Taniyama, Kosuke; Itoh, Hideomi; Takuwa, Atsushi; Sasaki, Yasuyuki; Yajima, Shunsuke; Toyofuku, Masanori; Nomura, Nobuhiko; Takaya, Naoki

    2012-01-01

    Hydrazones are natural and synthetic compounds containing a C=N-N moiety. Here we found that the opportunistic pathogen Pseudomonas aeruginosa PAO1 produced NAD+- or NADP+-dependent hydrazone dehydrogenase (HDH), which converts hydrazones to the corresponding hydrazides and acids rather than to the simple hydrolytic product aldehydes. Gene cloning indicated that the HDH is part of the group X aldehyde dehydrogenase (ALDH) family, which is distributed among bacteria, although the physiological...

  6. The Influence of Maggot Excretions on PAO1 Biofilm Formation on Different Biomaterials

    Cazander, Gwendolyn; van Veen, Kiril E. B.; Bouwman, Lee H.; Bernards, Alexandra T.; Jukema, Gerrolt N.

    2008-01-01

    Biofilm formation in wounds and on biomaterials is increasingly recognized as a problem. It therefore is important to focus on new strategies for eradicating severe biofilm-associated infections. The beneficial effects of maggots (Lucilia sericata) in wounds have been known for centuries. We hypothesized sterile maggot excretions and secretions (ES) could prevent, inhibit, and break down biofilms of Pseudomonas aeruginosa (PAO1) on different biomaterials. Therefore, we investigated biofilm fo...

  7. Brain perfusion spect imaging with 99mTc-HM-PAO in Parkinson's disease

    Forty patients with Parkinson's disease were studied using 99mTc-HM-PAO brain perfusion SPECT. 62.5% (25 cases) showed abnormal blood perfusion. Among them 55% showed local decreased blood perfusion of cerebral cortex, 22% showed asymmetric decreased blood perfusion in basal gaglia, 10% showed decreased uptake of tracer in cerebellum. The pathophysiologic basis of the abnormality of brain blood perfusion were briefly discussed

  8. 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...

  9. [Research on Zhang's collated edition of Lei gong pao zhi lun (Master Lei's Discourse on Processing of Chinese Materia Medica)].

    Cheng, Li

    2010-05-01

    Lei gong pao zhi lun (Master Lei's Discourse on Processing of Chinese Materia Medica) collated by Zhang Ji, and printed by Zhang's Yisheng Tang in Chengdu in 1932 was the first collated edition. Its original edition was not Jing shi zheng lei bei ji ben cao (Classified Materia Medica from Historical Classics for Emergency) of the Song Dynasty, but was Xiu shi zhi nan (Instruction for Drug Processing) and Lei gong pao zhi yao xing jie (Explanation on Master Lei's Properties of Drugs Processing) of the Qing Dynasty. The contents of this collated edition was far from Lei gong pao zhi lun with many mistakes, and was not the best edition to study Lei gong pao zhi lun. PMID:21029711

  10. Regulation of ornithine utilization in Pseudomonas aeruginosa (PAO1) is mediated by a transcriptional regulator, OruR.

    Hebert, M.D.; Houghton, J E

    1997-01-01

    We have used transpositional mutagenesis of a proline auxotroph (PAO951) to isolate an ornithine utilization (oru) mutant of Pseudomonas aeruginosa (PAO951-4) that was unable to use ornithine efficiently as the sole carbon and nitrogen source. DNA sequence analysis of the inactivated locus confirmed that the transposon had inserted into a locus whose product demonstrated significant primary sequence homology to members of the AraC family of transcriptional activators. DNA mobility shift assay...

  11. Metagenomic characterization of 'Candidatus Defluviicoccus tetraformis strain TFO71', a tetrad-forming organism, predominant in an anaerobic-aerobic membrane bioreactor with deteriorated biological phosphorus removal.

    Nobu, Masaru K; Tamaki, Hideyuki; Kubota, Kengo; Liu, Wen-Tso

    2014-09-01

    In an acetate-fed anaerobic-aerobic membrane bioreactor with deteriorated enhanced biological phosphorus removal (EBPR), Defluviicoccus-related tetrad-forming organisms (DTFO) were observed to predominate in the microbial community. Using metagenomics, a partial genome of the predominant DTFO, 'Candidatus Defluviicoccus tetraformis strain TFO71', was successfully constructed and characterized. Examining the genome confirmed the presence of genes related to the synthesis and degradation of glycogen and polyhydroxyalkanoate (PHA), which function as energy and carbon storage compounds. TFO71 and 'Candidatus Accumulibacter phosphatis' (CAP) UW-1 and CAP UW-2, representative polyphosphate-accumulating organisms (PAO), have PHA metabolism-related genes with high homology, but TFO71 has unique genes for PHA synthesis, gene regulation and granule management. We further discovered genes encoding DTFO polyphosphate (polyP) synthesis, suggesting that TFO71 may synthesize polyP under untested conditions. However, TFO71 may not activate these genes under EBPR conditions because the retrieved genome does not contain all inorganic phosphate transporters that are characteristic of PAOs (CAP UW-1, CAP UW-2, Microlunatus phosphovorus NM-1 and Tetrasphaera species). As a first step in characterizing EBPR-associated DTFO metabolism, this study identifies important differences between DTFO and PAO that may contribute to EBPR community competition and deterioration. PMID:24428681

  12. Altering young tomato plant growth by nitrate and CO2 preserves the proportionate relation linking long-term organic-nitrogen accumulation to intercepted radiation.

    Adamowicz, Stéphane; Le Bot, Jacques

    2008-01-01

    * A previously published model of crop nitrogen (N) status based on intercepted photosynthetically active radiation (R(i), mol per plant) suggested that plant organic N accumulation is related to R(i) by a constant ratio, defined hereafter as the radiation use efficiency for N (NRUE). The aim of this paper was to compare the effects of N nutrition and CO2 enrichment on NRUE and RUE (radiation use efficiency for biomass accumulation). * In three unrelated glasshouse experiments, tomato plants (Solanum lycopersicum) grown in hydroponics were fed for 28 d (exponential growth) with full solutions containing constant NO3(-) concentrations ([NO3(-)]) ranging from 0.05 to 15 mol m(-3), both under ambient or CO2-enriched (1000 microl l(-1)) air. * Each experiment comprised five harvests. Low [NO3(-)] (organic N acquisition (NRUE) did not depend on C or N nutrition for young plants grown under unstressed conditions. PMID:18761639

  13. The effect of soil macrofauna on litter decomposition and soil organic matter accumulation during soil formation in spoil heaps after brown coal mining: A preliminary results

    Frouz, J. [Academy of Science for Czech Republic, Ceske Budejovice (Czech Republic)

    2002-07-01

    The effect of macrofauna on removal of litter from the soil surface and accumulation of organic matter in the mineral soil layer were studied in two post mining sites planted by alder of different ages (4 and 38 years), using field microcosms, that were either accessible or not to soil macrofauna. The microcosms contained two layers: litter layer (autochthonous alder litter) and mineral layer (clay - spoil material early after mining with low organic matter content). After one year of exposure, no significant effect of macrofauna on total organic carbon loss in whole system (i.e. in both layers pooled) was found. Nevertheless, the distribution of carbon between layers was affected. Macrofauna enhanced C removal from the litter layer and its accumulation in the mineral layer. The accumulation of C in the mineral layer resulted in long term enhancement of microbial biomass and respiration. This indicates that effect of soil fauna on decomposition estimated using litter bags with various mesh size may indicate effect of fauna on litter fragmentation and removal from surface rather than effect on litter mineralization.

  14. Seasonal fluxes and temperature-dependent accumulation of persistent organic pollutants in lakes: The role of internal biogeochemical cycling

    A dynamic flux model for lakes taking into account the interactions between atmospheric depositional and biogeochemical processes (BIODEP model) was used to assess the importance of internal cycling and biogeochemical processes with respect to accumulation of four different polychlorinated biphenyls (PCBs) (congeners 28, 52, 101 and 153) in Lake Redo, a high-altitude lake in the Spanish Pyrenees. To investigate the effect of temperature on sediment accumulation, the model was run at different temperatures and corresponding sediment inventories were plotted vs. reciprocal temperature. In line with measurements from a previous study looking at sediment inventories of 19 European high-altitude lakes (MOLAR study), we found a stronger temperature dependence of lake sediment concentrations for the less volatile/less soluble PCBs. Seasonal and annual mass balances were investigated and highlighted the importance of internal lake processes controlling the differences in sediment accumulation for the different PCB congeners. For example, the higher temperature dependence of sediment inventories for the high chlorinated congeners is due to the fast dynamics of water-to-sediment transport in comparison to atmospheric deposition processes. - A dynamic flux model was used to assess the importance of internal lake processes in controlling sediment accumulation for different PCB congeners.

  15. Studies on the chemical behaviour of radioactive nuclides in fresh water and their accumulation by fresh water organisms

    It is of importance to do the basic investigation on the cycling of radioactive nuclides in terrestrial environments. Up to this time, accumulation, excretion and distribution of radioactive nuclides such as 131I, sup(115m)Cd, 85Sr, 203Hg, 131Ba, 22Na and 58Co in fresh water fish have been investigated. This paper concentrates in accumulation and excretion of 131I, and distribution and excretion of 203Hg-labelled methyl mercury chloride in fresh water fish. It was observed that, under co-existence of IO3-, the concentration factor of 131I concerning fresh water fish came near to that of marine fish as if the accumulation of 131I were stimulated by IO3- ions. Clear difference was recognized on the excretion patterns of 131I between fresh water fish and marine fish. In case of fresh water fish, 131I was excreted much more through kidney than through gills. Biological half-life of 131I from whole body of fresh water fish was about 15 days. Transfer of 203Hg labelled methyl mercury chloride to the brain of carp was investigated by means of abdominal administration of the nuclide. Not so much accumulation was obtained in the brain. Biological half-life of the nuclide from the brain was calculated as 198 days. (author)

  16. Effects of feeding and organism loading rate on PCB accumulation by Lumbriculus variegatus in sediment bioaccumulation testing

    Sediment bioaccumulation test methods published by USEPA and ASTM in 2000 specify that the Lumbriculus variegatus, a freshwater oligochaete, should not be fed during the 28-day exposure and recommends an organism loading rate of total organic carbon in sediment to organism dry we...

  17. Regional cerebrocerebellar perfusion imaging in spinocerebellar degeneration using technetium-99m-HM-PAO

    Tanaka, Makoto; Inoue, Tomio; Kawarabayashi, Takeshi; Hirai, Shunsaku; Sasaki, Yasuhito

    1988-07-01

    A new rediopharmaceutical, technetium-99m hexamethylpropyleneamine oxime (/sup 99m/Tc-HM-PAO), has been reported to cross the blood-brain-barrier and to distribute in brain in proportion to regional blood flow. We report brain imaging with /sup 99m/Tc-HM-PAO using single photon emission computed tomography (SPECT) in 14 patients of olivopontocerebellar atrophy (OPCA), a subclass of spinocerebellar degeneration, and in 5 controls. In order to evaluate cerebellar blood flow semiquantitatively, the count ratio of cerebellar hemispheres to occipital cortex (C/O ratio) was compared to the regional blood flow ratio (PC/O ratio) obtained by quantitative positron emission tomography (PET) performed in 6 of the 14 patients. We also examined correlations between C/O ratio and clinical data such as duration of illness, clinical severity score, laterality of incoordination and atrophy score on X-ray CT. The results favored clinical usefulness of /sup 99m/Tc-HM-PAO. The C/O ratio in OPCA was significantly lower than in controls (p < 0.001) and close to PC/O ratio. In 7 out of 9 patients who showed constant asymmetric neurologic signs, cerebellar radioactivities were more reduced in the side where limbincoodination was more prominent. The C/O ratio and atrophic score on X-ray CT correlated significantly (p < 0.05). In a few cases, however, visible cerebellar hypoperfusion was demonstrated in spite of minimal cerebellar atrophy. There were no correlations between the C/O ratio and the other clinical data. Qualitatively the reconstructed sagittal image easily revealed cerebellar hypoactivity or hypoperfusion in OPCA because the occipital lobe and cerebellum appeared ajacently in a plane. (J.P.N.).

  18. Differential modification of the Pseudomonas aeruginosa PAO1 outer membrane under hydrogen peroxide and gamma ray

    Complete text of publication follows. Objective: Pseudomonas aeruginosa PAO1 is causes opportunistic infections in humans. Studies with animals suggest that an adaptive mechanism is important for the ability of P. aeruginosa PAO1. The adaptive mechanism is protective mechanism against oxidative stress. This mechanism is aimed at preventing by reactive oxygen species. Reactive oxygen species can induce and modulate a variety of biological responses including gene expression. Materials and Methods: Pseudomonas aeruginosa PAO1(a wild-type strain) was grown aerobically with vigorous shaking at 30 deg C in LB broth (Difco). When the optical cells density at 600 nm reached 0.4 that exposed to 0.5-50 mM H2O2 for 30 min and 30-100 Gy Gamma irradiation (60Co, ca.150 TBq of capacity, AECL) for 30 min. For the recovery, the cultures were immediately exchanged fresh media and incubation for 30 min. then, cells were prefixed with 2.5% glutaraldehyde for 30 min at 4 deg C. After two washes by centrifugation at 15,000 X g for 5 min each, the cells were postfixed with 1% osmium tetroxide for 16 h at 24 deg C. The sample was dehydrated with absolute ethanol, stained with 2% uracyl acetate, embedded in Epon resin. Thin sections were stained with lead citrate and uranyl acetate and observed with a electron microscope. Expression level of candidate genes were analyzed using real-time PCR. The amplification program was consist of one cycle at 94 deg C for 30 sec, followed 40 cycles of 94 deg C (5 sec) - 60 deg C (31 sec). Results and Conclusion: In the present study, we have observed differential membrane damage to P. aeruginosa PAO1 cells when exposed to different oxidative stresses such as hydrogen peroxide 0.5-50 mM for 30 min and gamma radiation 30-100 Gy for 30 min using TEM. In order to understand its behaviour, we isolated 3 genes which are related to membrane maintaining. Its transcription level was identified using Real-Time PCR. Each gene was differently expressed under

  19. Molecular cloning and characterization of the recA gene of Pseudomonas aeruginosa PAO

    The recA gene of Pseudomonas aeruginosa PAO has been isolated and introduced into Escherichia coli K-12. Resistance to killing by UV irradiation was restored in several RecA-E. coli K-12 hosts by the P. aeruginosa gene, as was resistance to methyl methanesulfonate. Recombination proficiency was also restored, as measured by HfrH-mediated conjugation and by the ability to propagate Fec-phage lambda derivatives. The cloned P. aeruginosa recA gene restored both spontaneous and mitomycin C-stimulated induction of lambda prophage in lysogens of a recA strain of E. coli K-12

  20. A study of 99mTc-HM-PAO brain SPECT in the senile parkinson's disease

    Thirty-three cases of senile Parkinson's disease (PD) imaged by 99mTc-HM-PAO brain SPECT were reported. 66.7% of the patients had cortical hypoperfusion and 18.2% showed asymmetrical hypoperfusion in the basal ganglia. Such a finding was not related with the Hoehn-Yahr stage and the laterality of motor symptoms. If complicated with dementia, the SPECT brain imaging showed similar pattern in Alzheimer's disease with diffuse hypoperfusion in cortical area reflecting widespread pathological changes in tremor paralysis

  1. Speciation of naturally-accumulated uranium in an organic-rich soil of an alpine region (Switzerland)

    Simona Regenspurg; Margot-Roquier, C.; Harfouche, M.; P. Froidevaux; Steinmann, P.; Junier, P.; Bernier-Latmani, R.

    2010-01-01

    Very high concentrations of uranium (up to 4000 ppm) were found in a natural soil in the Dischma valley, an alpine region in the Grisons canton in Switzerland. The goal of this study was to examine the redox state and the nature of uranium binding in the soil matrix in order to understand the accumulation mechanism. Pore water profiles collected from Dischma soil revealed the establishment of anoxic conditions with increasing soil depth. A combination of chemical extraction methods and spectr...

  2. Quantitative Trait Loci and Inter-Organ Partitioning for Essential Metal and Toxic Analogue Accumulation in Barley

    Reuscher, Stefan; Kolter, Andreas; Hoffmann, Astrid; Pillen, Klaus; Krämer, Ute

    2016-01-01

    The concentrations of both essential nutrients and chemically similar toxic analogues accumulated in cereal grains have a major impact on the nutritional quality and safety of crops. Naturally occurring genetic diversity can be exploited for the breeding of improved varieties through introgression lines (ILs). In this study, multi-element analysis was conducted on vegetative leaves, senesced flag leaves and mature grains of a set of 54 ILs of the wild ancestral Hordeum vulgare ssp. spontaneum...

  3. 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

  4. Cadmium, copper, and lead accumulation and bioconcentration in the vegetative and reproductive organs of Raphanus sativus: implications for plant performance and pollination.

    Hladun, Kristen R; Parker, David R; Trumble, John T

    2015-04-01

    Several studies have found high levels of cadmium (Cd), copper (Cu), and lead (Pb) in honey bee hives located near urbanized or industrial areas. Insect herbivores and pollinators may come in contact with environmental contaminants in the leaves and flowers they forage upon in these areas. Our study quantified which of these metals are accumulated in the tissues of a common weedy plant that can serve as a route of exposure for insects. We grew Raphanus sativus (crop radish) in semi-hydroponic sand culture in the greenhouse. Plants were irrigated with nutrient solutions containing Cd, Cu, or Pb at four concentrations (control, low, medium, high). Plant performance, floral traits, and metal accumulation were measured in various vegetative and reproductive plant organs. Floral traits and flower number were unaffected by all metal treatments. Copper accumulated at the highest concentrations in flowers compared to the other two metals. Copper and Cd had the highest translocation indices, as well as higher bioconcentration factors compared to Pb, which was mostly immobile in the plant. Copper posed the highest risk due to its high mobility within the plant. In particular, accumulation of metals in leaves and flowers suggests that herbivores and pollinators visiting and foraging on these tissues may be exposed to these potentially toxic compounds. PMID:25845355

  5. Sources and accumulation of organic carbon in the Pearl River Estuary surface sediment as indicated by elemental, stable carbon isotopic, and carbohydrate compositions

    He, B.; Dai, M.; Huang, W.; Liu, Q.; Chen, H.; Xu, L.

    2010-10-01

    Organic matter in surface sediments from the upper reach of the Pearl River Estuary and Lingdingyang Bay, as well as the adjacent northern South China Sea shelf was characterized using a variety of techniques, including elemental (C and N) ratio, bulk stable organic carbon isotopic composition (δ13C), and carbohydrate composition analyses. Total organic carbon (TOC) content was 1.21±0.45% in the upper reach, down to 1.00±0.22% in Lingdingyang Bay and to 0.80±0.10% on the inner shelf and 0.58±0.06% on the outer shelf. δ13C values ranged from -25.1‰ to -21.3‰ in Lingdingyang Bay and the South China Sea shelf, with a trend of enrichment seawards. The spatial trend in C/N ratios mirrored that of δ13C, with a substantial decrease in C/N ratio offshore. Total carbohydrate yields ranged from 22.1 to 26.7 mg (100 mg OC)-1, and typically followed TOC concentrations in the estuarine and shelf sediments. Total neutral sugars, as detected by the nine major monosaccharides (lyxose, rhamnose, ribose, arabinose, fucose, xylose, galactose, mannose, and glucose), were between 4.0 and 18.6 mg (100 mg OC)-1 in the same sediments, suggesting that significant amounts of carbohydrates were not neutral aldoses. Using a two end-member mixing model based on δ13C values and C/N ratios, we estimated that the terrestrial organic carbon contribution to the surface sediment TOC was ca. 78±11% for Lingdingyang Bay, 34±4% for the inner shelf, and 5.5±1% for the outer shelf. The molecular composition of the carbohydrate in the surface sediments also suggested that the inner estuary was rich in terrestrially derived carbohydrates but that their contribution decreased offshore. A relatively high abundance of deoxyhexoses in the estuary and shelf indicated a considerable bacterial source of these carbohydrates, implying that sediment organic matter had undergone extensive degradation and/or transformation during transport. Sediment budget based on calculated regional accumulation rates

  6. Sources and accumulation of organic carbon in the Pearl River Estuary surface sediment as indicated by elemental, stable carbon isotopic, and carbohydrate compositions

    B. He

    2010-10-01

    /or transformation during transport. Sediment budget based on calculated regional accumulation rates showed that only ~50% of the influxes of terrestrial organic carbon were accumulated in the estuary. This relatively low accumulation efficiency of terrestrial organic matter as compared to the total suspended solids (accumulation efficiency ~73% suggested significant degradation of the terrestrial organic carbon within the estuarine system after its discharge from the river. This study demonstrated that the combination of the bulk organic matter properties together with the isotopic composition and molecular-level carbohydrate compositions can be an efficient way to track down the source and fate of organic matter in highly dynamic estuarine and coastal systems. The predominance of terrestrially originated organic matter in the sediment and its generally low accumulation efficiency within the estuary is not surprising, and yet it may have important implications in light of the heavy anthropogenic discharges into the Pearl River Estuary during the past thirty years.

  7. Influence of marginal highs on the accumulation of organic carbon along the continental slope off western India

    Rao, B; Veerayya, M.

    0.70 to 5.86%. Highest values of organic carbon are recorded on the marginal highs (5.12-5.86%), followed by shelf margin basin (3.53-4.22%) and the continental slope (1.80-3.84%). The organic carbon content is relatively low in the Arabian Basin (0...

  8. Accumulation of polycyclic aromatic hydrocarbons (PAHs) and oxygenated PAHs (OPAHs) in organic and mineral soil horizons from four U.S. remote forests.

    Obrist, Daniel; Zielinska, Barbara; Perlinger, Judith A

    2015-09-01

    We characterized distributions of 23 polycyclic aromatic hydrocarbons (Σ23PAH) and nine oxygenated PAHs (Σ9OPAH) in four remote forests. We observed highest Σ23PAH and Σ9OPAH concentrations in a coniferous forest in Florida, particularly in organic layers which we attributed to frequent prescribed burning. Across sites, Σ23PAH and Σ9OPAH concentrations strongly increased from surface to humidified organic layers (+1626%) where concentrations reached up to 584 ng g(-1). Concentrations in mineral soils were lower (average 37 ± 8 ng g(-1)); but when standardized per unit organic carbon (OC), PAH/OC and OPAH/OC ratios were at or above levels observed in organic layers. Accumulation in litter and soils (i.e., enrichment factors with depth) negatively correlated with octanol-water partition coefficients (Kow) and therefore was linked to water solubility of compounds. Concentrations of Σ9OPAHs ranged from 6 ± 6 ng g(-1) to 39 ± 25 ng g(-1) in organic layers, and from 3 ± 1 ng g(-1) to 11 ± 3 ng g(-1) in mineral soils, and were significantly and positively correlated to Σ23PAHs concentrations (r(2) of 0.90) across sites and horizons. While OPAH concentrations generally decreased from organic layers to mineral soil horizons, OPAH/OC ratios increased more strongly with depth compared to PAHs, in particular for anthrone, anthraquinone, fluorenone, and acenaphthenequinone. The strong vertical accumulation of OPAH relative to OC was exponentially and negatively correlated to C/N ratios (r(2)=0.67), a measure that often is used for tissue age. In fact, C/N ratios alone explained two-thirds of the variability in OPAH/OC ratios suggesting particularly high retention, sorption, and persistency of OPAHs in old, decomposed carbon fractions. PMID:25929871

  9. SPECIFIC FEATURES OF DISTRIBUTING AND ACCUMULATION Of HEAVY METALS ARE IN ORGANISMS Of THE FISHES BENTOPHAGES Of KREMENCHUG STORAGE POOL

    А. Melnik

    2013-03-01

    Full Text Available Maintenance of heavy metals is investigational in organs and fabrics of the fishes bentophages - bream (Abramis brama L., roach (Rutilus rutilus L. and white bream (Blicca bjoerkna L. of the Kremenchug storage pool. It is set that after maintenance of heavy metals in organs and fabrics in the direction of increase of their concentration it is possible to present such row: bream < white bream < roach.

  10. SPECIFIC FEATURES OF DISTRIBUTING AND ACCUMULATION Of HEAVY METALS ARE IN ORGANISMS Of THE FISHES BENTOPHAGES Of KREMENCHUG STORAGE POOL

    А. Melnik; N. Vlasova; E. Kolos; A. Didenko

    2013-01-01

    Maintenance of heavy metals is investigational in organs and fabrics of the fishes bentophages - bream (Abramis brama L.), roach (Rutilus rutilus L.) and white bream (Blicca bjoerkna L.) of the Kremenchug storage pool. It is set that after maintenance of heavy metals in organs and fabrics in the direction of increase of their concentration it is possible to present such row: bream < white bream < roach.

  11. Effect of nitrofurans and NO generators on biofilm formation by Pseudomonas aeruginosa PAO1 and Burkholderia cenocepacia 370.

    Zaitseva, Julia; Granik, Vladimir; Belik, Alexandr; Koksharova, Olga; Khmel, Inessa

    2009-06-01

    Antibacterial drugs in the nitrofuran series, such as nitrofurazone, furazidin, nitrofurantoin and nifuroxazide, as well as the nitric oxide generators sodium nitroprusside and isosorbide mononitrate in concentrations that do not suppress bacterial growth, were shown to increase the capacity of pathogenic bacteria Pseudomonas aeruginosa PAO1 and Burkholderia cenocepacia 370 to form biofilms. At 25-100microg/ml, nitrofurans 2-2.5-fold enhanced biofilm formation of P. aeruginosa PAO1, and NO donors 3-6-fold. For B. cenocepacia 370, the enhancement was 2-5-fold (nitrofurans) and 4.5-fold (sodium nitroprusside), respectively. PMID:19460431

  12. Application of deformable registration and empirical method to calculate the accumulated dose for normal tissues and organs at risks in lung cancer radiotherapy plans

    Objective: To evaluate the accumulated doses to normal tissues and organs at risks (OARs) of patients with lung cancer in radiotherapy plans by using the deformable registration method, and make comparison with the empirical calculation method. Methods: Ten patients with lung cancer were analyzed retrospectively. 3D-CRT or IMRT plans were designed before treatment. CT to simulator was rescanned and the same treatment plan was redesigned during radiotherapy. Based on the deformable registration method, the Mimvista software was used to calculate the accumulated doses to normal tissues and OARs in two CT images respectively. The empirical estimation algorithm was calculated by the linear relationship between the fractions and the total prescribed dose. Results: The target coverage of patients had no significant difference in two plans. There were no significant differences in all the dose volume parameters for normal tissues and OARs, except the mean dose to right lung (t=2.98, P<0.05) when the the same plan was conducted in position-setting and reposition CT images. Conclusions: The empirical estimation for the accumulated dose could be used to evaluate the dose and volume parameters for normal tissues and OARs in lung cancer by the same plan. (authors)

  13. 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)

  14. Accumulation and distribution of 137Cs in the organic matter of soil during decomposition of forest dead leaves

    The samples of dead leaves, litter, and soil were taken in 1996 in the forest area located in the Ovruch district of the Zhytomyr region, Ukraine and where ground depositions of 137Cs range from 100 to 590 kBq/m2. Radiocaesium activity of all organic fractions of litter decreased in comparison with radioactivity of the same fractions of dead leaves. Only hydrochloric acid hydrolysate of hemicellulose had a very big radioactivity reached 12-32% of radioactivity of samples. Apparently, hydrochloric acid extracted exchangeable 137Cs (11-17%) and joined one with mineral substances. Organic matter content in the soil layer at a depth of 6-12 cm was 3,4%, the main organic fraction components were residues after hydrolysis and humus substances extracted by sodium pyrophosphate - 52.2 and 28.8%, respectively. In the same soil layer, radiocaesium activity was 0.63 kBg/kg

  15. Influence of organic supplements on production of shoot and callus biomass and accumulation of bacoside in Bacopa monniera (L.) Pennell.

    Parale, Anuradha; Barmukh, Rajkumar; Nikam, Tukaram

    2010-01-01

    Production of valuable secondary metabolites through plant cell or organ culture is the best suited alternative to extraction of whole plant material and to increase production of secondary metabolites in in-vitro systems, feeding precursor or intermediate metabolites is an obvious and popular approach. The present investigation was aimed to study the influence of feeding of organic supplements, glycine (0–125 μM), ferulic acid (0–200 μM), phenylalanine (0–200 μM), α-ketoglutaric acid (0–200 ...

  16. Accumulation of sediment, organic matter and trace metals with space and time, in a creek along Mumbai coast, India

    Fernandes, L.; Nayak, G.N.; Ilangovan, D.; Borole, D.V.

    the sediment deposition trend of the area. The data was further processed using factor and cluster analyses. The results indicate that the sediments from site ManI, had finer sediment composition, higher porosity, organic matter and metal contents but exhibited...

  17. [Effects of long-term application of organic fertilizer and superphosphate on accumulation and leaching of Olsen-P in Fluvo-aquic soil].

    Huang, Shao-Min; Guo, Dou-Dou; Zhang, Shui-Qing

    2011-01-01

    Based on a 20-year experiment of fertilization with organic and chemical fertilizers on a Fluvo-aquic soil under wheat-corn cropping system, this paper studied the relationships between Olsen-P concentration in plough layer and crop yields as well as the accumulation and vertical translocation of Olsen-P in soil profile. The results showed that when the Olsen-P concentration in plough layer maintained at 10-40 mg x kg(-1), the grain yields of wheat and corn were higher, whereas when the concentration of Olsen-P in plough layer was higher than 40 mg x kg(-1), it started to leach, which meant that in light loam Fluvo-aquic soil, the threshold value for P leaching might be 40 mg x kg(-1). In the treatments of chemical fertilization (NPK) and corn straw returning (SNPK) with the P application rate of 77-90 kg x hm(-2), the Olsen-P concentration in plough layer was increased by 0.63-0.72 mg x kg(-1) per 100 kg x hm(-2) of applied P, with an annual increment of 0.49-0.65 mg x kg(-1) and needed 45-60 years for reaching the threshold value for P leaching. In the treatments of chemical fertilization combined with manure application (MNPK, MNPK2, and 1.5MNPK), the formula of Olsen-P accumulation in 0-20 cm soil layer were Y(MNPK) = 3.1097x + 6.9615 (R2 = 0.8562), Y(MNPK2) = 2.4765x + 13.563 (R2 = 0.9307), and Y1.5MNPK = 4.506x + 6.4464 (R2 = 0.8862). It might take 8 years to reach the threshold value for Olsen-P leaching when the P application rate in treatment 1.5MNPK was 210 kg x hm(-2), 11 years when the P application rate in treatments MNPK2 and MNPK was 125 and 140 kg x hm(-2). Organic fertilization combined with chemical fertilization increased the Olsen-P accumulation rate being 2.5 times higher than chemical fertilization. Excessive application of organic fertilizer could increase the accumulation and leaching of Olsen-P in soil profile. PMID:21548294

  18. 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.

  19. Environmental monitoring of the area surrounding oil wells in Val d'Agri (Italy): element accumulation in bovine and ovine organs.

    Miedico, Oto; Iammarino, Marco; Paglia, Giuseppe; Tarallo, Marina; Mangiacotti, Michele; Chiaravalle, A Eugenio

    2016-06-01

    In this work, environmental heavy metal contamination in the Val d'Agri area of Southern Italy was monitored, measuring the accumulation of 18 heavy metals (U, Hg, Pb, Cd, As, Sr, Sn, V, Ni, Cr, Mo, Co, Cu, Zn, Ca, Mn, Fe, and Al) in the organs of animals raised in the surrounding area (kidney, lung, and liver of bovine and ovine species). Val d'Agri features various oil processing centers which are potentially a significant source of environmental pollution, making it essential to perform studies that will outline the state of the art on which any recovery plans and interventions may be developed. The analysis was carried out using official and accredited analytical methods based on inductively coupled plasma mass spectrometry, and the measurements were statistically processed in order to give a contribution to risk assessment. Even though five samples showed Pb and Cd concentrations above the limits defined in the European Commission Regulation (EC) No 1881/2006, the mean concentrations of most elements suggest that contamination in this area is low. Consequently, these results also suggest that there is no particular risk for human exposure to toxic trace elements. Nevertheless, the findings of this work confirm that element accumulation in ovine species is correlated with geographical livestock area. Therefore, ovine-specific organs might be used as bioindicators for monitoring contamination by specific toxic elements in exposed areas. PMID:27165602

  20. 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

  1. RothC simulation of carbon accumulation in soil after repeated application of widely different organic amendments

    Peltre, Clément; Christensen, Bent Tolstrup; Dragon, Sophine;

    2012-01-01

    Multi-compartment soil carbon (C) simulation models such as RothC are widely used for predicting changes in C stocks of arable soils. However, rigorous routines for establishing entry pools that account for the diversity of exogenous organic matter (EOM) applied to croplands are still lacking. We...... obtained data on changes in soil C stocks after repeated applications of EOM from four long-term experiments (LTEs): Askov K2 (Denmark, 31 yrs), Qualiagro (France, 11 yrs), SERAIL (France, 14 yrs) and Ultuna (Sweden, 52 yrs). The adjustment of the partition coefficients of total organic C in EOM (EOM......-TOC potentially retained in soil. IROC was derived from the C found in the soluble, lignin + cutin-like and cellulose-like Van Soest fractions and the proportion of EOM-TOC mineralized during 3 days of incubation. Using the EOM partition coefficients derived from these laboratory analyses resulted in Roth...

  2. Use of [/sup 99m/Tc]-HM-PAO in the diagnosis of primary degenerative dementia

    The clinical value of single photon emission computed tomography (SPECT) in the differential diagnosis of dementia due to cerebral atrophy was evaluated by comparing the pattern of distribution [/sup 99m/Tc]-HM-PAO in three dementing conditions. Imaging was carried out in 26 patients with suspected Alzheimer's disease, 14 with dementia of the frontal-lobe type, and 13 with progressive supranuclear palsy. Images were evaluated and reported without knowledge of clinical diagnosis with respect to regions of reduced uptake of tracer. Reduced uptake in the posterior cerebral hemispheres was characteristic of Alzheimer's disease, while selective anterior hemisphere abnormalities characterized both dementia of the frontal-lobe type and progressive supranuclear palsy. The latter conditions could be distinguished on the basis of the appearance of integrity of the rim of the frontal cortex. The technique has an important role in the differentiation of degenerative dementias

  3. Use of (/sup 99m/Tc)-HM-PAO in the diagnosis of primary degenerative dementia

    Testa, H.J.; Snowden, J.S.; Neary, D.; Shields, R.A.; Burjan, A.W.; Prescott, M.C.; Northen, B.; Goulding, P.

    1988-12-01

    The clinical value of single photon emission computed tomography (SPECT) in the differential diagnosis of dementia due to cerebral atrophy was evaluated by comparing the pattern of distribution (/sup 99m/Tc)-HM-PAO in three dementing conditions. Imaging was carried out in 26 patients with suspected Alzheimer's disease, 14 with dementia of the frontal-lobe type, and 13 with progressive supranuclear palsy. Images were evaluated and reported without knowledge of clinical diagnosis with respect to regions of reduced uptake of tracer. Reduced uptake in the posterior cerebral hemispheres was characteristic of Alzheimer's disease, while selective anterior hemisphere abnormalities characterized both dementia of the frontal-lobe type and progressive supranuclear palsy. The latter conditions could be distinguished on the basis of the appearance of integrity of the rim of the frontal cortex. The technique has an important role in the differentiation of degenerative dementias.

  4. Feeding behaviour of Caenorhabditis elegans is an indicator of Pseudomonas aeruginosa PAO1 virulence

    Shawn Lewenza

    2014-08-01

    Full Text Available Caenorhabditis elegans is commonly used as an infection model for pathogenesis studies in Pseudomonas aeruginosa. The standard virulence assays rely on the slow and fast killing or paralysis of nematodes but here we developed a behaviour assay to monitor the preferred bacterial food sources of C. elegans. We monitored the food preferences of nematodes fed the wild type PAO1 and mutants in the type III secretion (T3S system, which is a conserved mechanism to inject secreted effectors into the host cell cytosol. A ΔexsEΔpscD mutant defective for type III secretion served as a preferred food source, while an ΔexsE mutant that overexpresses the T3S effectors was avoided. Both food sources were ingested and observed in the gastrointestinal tract. Using the slow killing assay, we showed that the ΔexsEΔpscD had reduced virulence and thus confirmed that preferred food sources are less virulent than the wild type. Next we developed a high throughput feeding behaviour assay with 48 possible food colonies in order to screen a transposon mutant library and identify potential virulence genes. C. elegans identified and consumed preferred food colonies from a grid of 48 choices. The mutants identified as preferred food sources included known virulence genes, as well as novel genes not identified in previous C. elegans infection studies. Slow killing assays were performed and confirmed that several preferred food sources also showed reduced virulence. We propose that C. elegans feeding behaviour can be used as a sensitive indicator of virulence for P. aeruginosa PAO1.

  5. Using the natural abundance of 13C and 15N to examine soil organic matter accumulated during 100 years of cropping

    The 13C natural abundance technique was applied to soils of a long term experimental field in the study of organic matter turnover. The technique allowed evaluation of soil organic matter (SOM) originating from residues of different cropping systems that partially replaced the native prairie SOM mineralized during 100 years of cropping history. A large pool of the prairie SOM was highly resistant to decay, demonstrating a turnover time of 1000 years. Labile prairie SOM, lost when cultivation was initiated, had a half-life of 11 years. Accumulated SOM that originated from residues of a particular crop demonstrated a similar half-life as it decayed and was replaced by new SOM from residues of a different crop. Apparent turnover time for soil organic carbon calculated from annual input of crop residues to the soil for different cropping systems ranged from 2 years for corn to 6.4 years for timothy sod. The natural abundance of 15N showed significant change for soil treated with chemical fertilizer or manure relative to the control soil. Manure applied to timothy for 100 years contributed 24% of existing soil organic nitrogen. (author). 12 refs, 2 figs, 3 tabs

  6. Effect of sludge age on methanogenic and glycogen accumulating organisms in an aerobic granular sludge process fed with methanol and acetate.

    Pronk, M; Abbas, B; Kleerebezem, R; van Loosdrecht, M C M

    2015-09-01

    The influence of sludge age on granular sludge formation and microbial population dynamics in a methanol- and acetate-fed aerobic granular sludge system operated at 35°C was investigated. During anaerobic feeding of the reactor, methanol was initially converted to methane by methylotrophic methanogens. These methanogens were able to withstand the relatively long aeration periods. Lowering the anaerobic solid retention time (SRT) from 17 to 8 days enabled selective removal of the methanogens and prevented unwanted methane formation. In absence of methanogens, methanol was converted aerobically, while granule formation remained stable. At high SRT values (51 days), γ-Proteobacteria were responsible for acetate removal through anaerobic uptake and subsequent aerobic growth on storage polymers formed [so called metabolism of glycogen-accumulating organisms (GAO)]. When lowering the SRT (24 days), Defluviicoccus-related organisms (cluster II) belonging to the α-Proteobacteria outcompeted acetate consuming γ-Proteobacteria at 35°C. DNA from the Defluviicoccus-related organisms in cluster II was not extracted by the standard DNA extraction method but with liquid nitrogen, which showed to be more effective. Remarkably, the two GAO types of organisms grew separately in two clearly different types of granules. This work further highlights the potential of aerobic granular sludge systems to effectively influence the microbial communities through sludge age control in order to optimize the wastewater treatment processes. PMID:26059251

  7. 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...

  8. 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...

  9. The Accumulation and Histological Effects of The Organometallic Fungicide Propineb on The Organs of Fetuses and Female Rats During Pregnancy

    Güven, Kemal

    1999-01-01

    Dithiocarbamate propineb is an organometal fungicide, which is widely used for the control of diseases in plants. Female Wistar rats were exposed orally to propineb concentrations of 200 and 400 ppm, from the 6th day of gestation up to birth. At 400 ppm, propineb showed a variety of macroscopic (e.g. ptosis and paralysis) and microscopic symptoms in the organs of both fetuses and female rats. We found that the body weights of both one-day old litters and their propineb-treated mothers we...

  10. Expression, purification, crystallization and preliminary crystallographic analysis of PA3885 (TpbA) from Pseudomonas aeruginosa PAO1

    Yang, Wen; Li, Kan; Bai, Yuwei; Zhou, Ruimin; Zhou, Weihong; Bartlam, Mark

    2010-01-01

    PA3885 (TpbA), a tyrosine phosphatase, may function as a balancing factor between biofilm formation and motility in the opportunistic pathogen P. aeruginosa. Here, the expression, purification, crystallization and preliminary crystallographic analysis of PA3885 from P. aeruginosa PAO1 are reported.

  11. Assessment of the arterial input curve for [99mTc]-d,l-HM-PAO by rapid octanol extraction

    Andersen, A R; Friberg, H; Lassen, N A;

    1988-01-01

    The in vitro conversion of the lipophilic molecule [99mTc]-d,l-hexamethylpropyleneamine oxime [( 99mTc]-d,l-HM-PAO) to a hydrophilic form was studied in saline, plasma, and blood at 37 degrees C by paper chromatography and by octanol extraction. The octanol:saline ratio was 79.9. From this value...

  12. Expression of the recA gene of Pseudomonas aeruginosa PAO is inducible by DNA-damaging agents

    Miller, R.V.; Kokjohn, T.A.

    1988-05-01

    Western (immunoblot) analysis using Escherichia coli anti-RecA antiserum revealed that expression of the RecA protein of Pseudomonas aeruginosa PAO is induced upon exposure of the bacterium to UV irradiation or norfloxacin, a quinolone related to nalidixic acid.

  13. Evaluation of Long-Term Application of Organic Residues on Accumulation of Organic Matter and Improvement of Soil Chemical Properties in a Clay Terrace Soil of Bangladesh

    Egashira, Kazuhiko; Han, Jing-Long; Karim, A.J.M. Sirajul; Abu Zofar Md. Moslehuddin; Yamada, Yoshio

    2003-01-01

    The field experiment on the long-term application of organic residues was started in 1988 at the farm of Bangabandhu Shekh Mujibur Rahamn Agricultural University (BSMRAU; named as Institute of Postgraduate Studies in Agriculture (ISPA)until 1998) and is continued until now. Five kinds of organic residues (no-application, rice straw green manure, compost and cowdung) were applied every June to cover soil surface uniformly as a thin layer and incorporated into soil to the depth of 10cm. Rice(Ju...

  14. Accumulation of 137Cs after potassium fertilization in plant organs of Salix viminalis L. and in combusted ash

    The effect of potassium (K) application at a common rate on 137Cs uptake and distribution within basket willow (Salix viminalis L.) and 137Cs activity in willow ash was studied in a three-year field experiment on a sandy soil. Experimental plots fertilized with 60 kg N and 48 kg K per ha were compared with a control with similar N but no K fertilization. There was no significant difference in 137Cs activity concentrations in plants growing on plots with or without fertilizer K. Higher concentrations of 137Cs activity were found in roots and leaves of willow than in stems and cuttings. The highest 137Cs activity concentration was detected in the fine roots (size 0-1 mm). The transfer factor (TFg) of 137Cs in different plant organs varied between 0.1 x 10-3 and 2.6 x 10-3 m2 kg-1. After combustion, 137Cs activity concentrations in ash produced from wood chips from K-fertilized plots were significantly lower than those in ash originating from plots without K fertilization. Fly ash had higher 137Cs concentrations than bottom ash and all ash samples had 137Cs concentrations that were well below the 10 000 Bq kg-1 Swedish limit for spreading on land. -- Highlights: → We studied effect of potassium on 137Cs uptake by basket willow (Salix viminalis). → No significant difference in 137Cs activity in plants was found. → Higher 137Cs activity was found in roots and leaves than in stems and cuttings. → Highest 137Cs activity was detected in fine roots (size 0-1 mm). → Transfer factors of 137Cs in plant organs were 0.1 x 10-3 and 2.6 x 10-3 m2 kg-1.

  15. Use of technetium-99m-HM-PAO in the assessment of patients with dementia and other neuropsychiatric conditions

    One hundred fourteen patients suffering from neuropsychiatric conditions have been studied using 99mTc-labeled hexamethylpropyleneamine oxime (HM-PAO) and single photon emission computed tomography (SPECT). Ninety-one patients had a firm clinical diagnosis while 23 were examined without knowledge of the clinical diagnosis. Of the 91 patients, 51 were suffering from dementia, 25 multi-infarct type and 26 Alzheimer's disease. In 19 of the Alzheimer's patients, a characteristic pattern of decreased perfusion in the parieto-occipital regions was demonstrated while those with multi-infarct type showed varying degrees of irregular uptake in the cerebral cortex. These appearances are similar to those shown with positron emission tomography (PET) and we believe that HM-PAO will provide a widely available method for identifying patients with Alzheimer's disease. Twenty-nine patients were suffering from diseases involving the basal ganglia. Fifteen patients with Parkinson's disease showed no significant abnormality in basal ganglia uptake, while 7 or 8 patients with Huntington's disease who had full examinations showed decreased uptake in the caudate nuclei. Similarly, four of six patients with other basal ganglia diseases showed impaired uptake by basal ganglia, and it is concluded that HM-PAO may be useful for the diagnosis and management of this type of patient. Twenty-three patients received HM-PAO imaging as part of their diagnostic work-up; in 19 of them, detailed follow-up was obtained, which indicated that in 7 cases the result of the HM-PAO scan altered the clinical diagnosis and in 9 cases resulted in a change in management. In the remaining 13 cases, the study was found to be helpful in confirming the diagnosis

  16. The evaluation of collateral cerebral circulation using 99mTc-HM-PAO SPECT during the balloon Matas test

    A balloon Matas test using single-photon emission computed tomography (SPECT) and 99mTC-hexamethyl propyleneamine oxime (99mTc-HM-PAO) was performed to evaluate collateral cerebral circulation during temporary carotid occlusion in 14 patients (6 with internal carotid artery aneurysms, 2 with basilar skull tumors, 5 with neck tumors, and one with traumatic common carotid artery aneurysm). The occlusion sites were internal carotid artery in 12 patients and common carotid artery in 2 patients. The observation of the neurological state, the carotid stump pressure, cerebral angiography for assessing collateral circulation and electroencephalographic (EEG) monitoring were also undertaken in all patients. In four patients, regional cerebral blood flow (rCBF) was measured by xenon-inhalation method and compared with the CBF image by 99mTc-HM-PAO SPECT. The 99mTC-HM-PAO (20 mCi) was injected intravenously 3 minutes before balloon deflation. In all patients, the neurological state and EEG showed no abnormality during the balloon Matas test. Eight patients were considered treatable by the permanent occlusion of the carotid artery. Permanent carotid ligation was carried out in five of these 8 patients, and no neurological deficit occurred. Permanent occlusion of the carotid artery was impossible in 5 patients because of marked reduction of CBF. 99mTc-HM-PAO SPECT should three-dimensional cerebral perfusion pattern. In conclusion, a balloon Matas test using 99mTC-HM-PAO SPECT is a reliable, simple and safe method of evaluating the collateral cerebral circulation. (J.P.N.)

  17. Sources and accumulation of organic carbon in the Pearl River Estuary surface sediment as indicated by elemental, stable carbon isotopic, and carbohydrate compositions

    B. He

    2010-04-01

    Full Text Available Organic matter in surface sediments from the upper reach of the Pearl River Estuary and Lingdingyang Bay, as well as the adjacent northern South China Sea shelf was characterized by a variety of techniques, including elemental (C and N, stable carbon isotopic (δ 13C composition, as well as molecular-level analyses. Total organic carbon (TOC content was 1.61±1.20% in the upper reach down to 1.00±0.22% in Lingdingyang Bay and to 0.80±0.10% on the inner shelf and 0.58±0.06% on the outer shelf. δ13C values ranged from −25.11‰ to −21.28‰ across the studied area, with a trend of enrichment seaward. The spatial trend in C/N ratios mirrored that of δ13C, with a substantial decrease in C/N ratio from 10.9±1.3 in the Lingdingyang Bay surface sediments to 6.5±0.09 in the outer shelf surface sediments. Total carbohydrate yields ranged from 22.1 to 26.7 mg (100 mg OC−1, and typically followed TOC concentrations in the estuarine and shelf sediments, suggesting that the relative abundance of total carbohydrate was fairly constant in TOC. Total neutral sugars as detected by the nine major monosaccharides (lyxose, rhamnose, ribose, arabinose, fucose, xylose, galactose, mannose, and glucose yielded between 4.0 and 18.6 mg (100 mg OC−1 in the same sediments, suggesting that a significant amount of carbohydrates were not neutral aldoses. The bulk organic matter properties, isotopic composition and C/N ratios, combined with molecular-level carbohydrate compositions were used to assess the sources and accumulation of terrestrial organic matter in the Pearl River Estuary and the adjacent northern South China Sea shelf. Results showed a mixture of terrestrial riverine organic carbon with in situ phytoplankton organic carbon in the areas studied. Using a two end-member mixing model based on δ13C values and C/N ratios, we estimated that the terrestrial organic carbon contribution to

  18. The SPECT imaging shows the accumulation of neural progenitor cells into internal organs after systemic administration in middle cerebral artery occlusion rats.

    Lappalainen, Riikka S; Narkilahti, Susanna; Huhtala, Tuulia; Liimatainen, Timo; Suuronen, Tiina; Närvänen, Ale; Suuronen, Riitta; Hovatta, Outi; Jolkkonen, Jukka

    2008-08-01

    The regenerative potential of stem cells from various sources has been under intense investigation in the experimental models of cerebral ischemia. To end up with a restorative therapeutic treatment, it is crucial to get the cell transplants to the site of injury. Here, we evaluated the feasibility of small animal SPECT/CT in assessing the definite accumulation of (111)In-oxine-labeled human embryonic stem (ES) cell-derived neural progenitors and rat hippocampal progenitors after intravenous or intra-arterial administration (femoral vein vs. common carotid artery) in middle cerebral artery occlusion (MCAO) and sham-operated rats. Cell detection was carried out immediately and 24h after the infusion using a SPECT/CT device. The results showed that after intravenous injections both cell types accumulated primarily into internal organs, instead of brain. In contrast, after intra-arterial injection, a weak signal was detected in the ischemic hemisphere. Additional studies showed that the detection sensitivity of SPECT/CT device was approximately 1000 (111)In-oxine-labeled cells and labeling did not affect the cell viability. In conclusion, a small animal SPECT is powerful technique to study the whole body biodistribution of cell-based therapies. Our data showed that intravenous administration is not an optimal route to deliver neural progenitor cell-containing transplants into the brain after MCAO in rats. PMID:18572314

  19. Enhanced energy conversion efficiency from high strength synthetic organic wastewater by sequential dark fermentative hydrogen production and algal lipid accumulation.

    Ren, Hong-Yu; Liu, Bing-Feng; Kong, Fanying; Zhao, Lei; Xing, Defeng; Ren, Nan-Qi

    2014-04-01

    A two-stage process of sequential dark fermentative hydrogen production and microalgal cultivation was applied to enhance the energy conversion efficiency from high strength synthetic organic wastewater. Ethanol fermentation bacterium Ethanoligenens harbinense B49 was used as hydrogen producer, and the energy conversion efficiency and chemical oxygen demand (COD) removal efficiency reached 18.6% and 28.3% in dark fermentation. Acetate was the main soluble product in dark fermentative effluent, which was further utilized by microalga Scenedesmus sp. R-16. The final algal biomass concentration reached 1.98gL(-1), and the algal biomass was rich in lipid (40.9%) and low in protein (23.3%) and carbohydrate (11.9%). Compared with single dark fermentation stage, the energy conversion efficiency and COD removal efficiency of two-stage system remarkably increased 101% and 131%, respectively. This research provides a new approach for efficient energy production and wastewater treatment using a two-stage process combining dark fermentation and algal cultivation. PMID:24582427

  20. Determination of mass accumulation rates for organic carbon, carbonate, metal and sediment on the eastern continental margin of the Black Sea sediments during Late Holocene

    Mass Accumulation Rates (MAR) in Black Sea samples for carbonate, organic carbon and some metal based on 210Pb dating are determined and their interpretation are presented. The samples are recovered from the international cruise 2000 organized by the IAEA as a part of the Marine Environmental Assessment of the Black Sea Region Technical Cooperation Project RER/2/003. In this study only one core (BS-23) located on the eastern continental margin of the Black Sea in water depth of 2168 m is examined. The sediment in these core consist of two units which are from top to bottom: the laminated coccolith marl and micro laminated sapropel units reach in organic carbon. These units were formed after the flooding of the lacustrine Black Sea basin by the Mediterranean waters via the Istanbul strait at 7150 yr BP. The total average MAR for the last 125 years for these site is found as 40.15 g.m-2.yr-1 (26 cm.kyr-1). Considering that the corrected AMS 14C ages, the average linear sedimentation rate for core BS-23 over 2000 yr. are found to be about 1.5 times lower than those for the last 125 yr. determined from the 210Pb data. This suggests that the sediment accumulation rate have significantly increased probably in the last few hundred years as a result of man's impact. The average MARTOC and MARCaCO3 in the upper three cm. of the core (Unit I) representing the last 125 yr. are 1.84 and 15.82 g.m-2.yr-1, respectively, whereas MARTOC and MARCaCO3 values in Unit II are 2.79 and 3.74 g.m-2.yr-1. The high MARCaCO3 in the unit I is caused by the coccolithophore E. huxleyi which forms the white laminae. In the upper part of the sediment, the Ba enrichment indicate a sharp increase in organic productivity that causes eutrophication process over the last 50 yr. Similarly Pb, Zn and Cu exhibit very sharp increase in the top part of the core, reaching more than twice the background values and attesting high metal inputs into the Black Sea during the last half century

  1. Organic UV filters inhibit multixenobiotic resistance (MXR) activity in Tetrahymena thermophila: investigations by the Rhodamine 123 accumulation assay and molecular docking.

    Gao, Li; Yuan, Tao; Cheng, Peng; Zhou, Chuanqi; Ao, Junjie; Wang, Wenhua; Zhang, Haimou

    2016-09-01

    Multixenobiotic resistance (MXR) transporters, which belong to ATP-binding cassette (ABC) family proteins, are present in living organisms as a first line of defense system against xenobiotics and environmental contaminants. The effects of six organic UV filters (4-methyl -benzylidene camphor, 4-MBC; benzophenone-3, BP-3; butyl methoxydibenzoyl-methane, BM-DBM; ethylhexyl methoxy cinnamate, EHMC; octocrylene, OC and homosalate, HMS) on multixenobiotic resistance (MXR) in Tetrahymena thermophila were investigated in this study. It was found that 4-MBC, BP-3 and BM-DBM could significantly inhibit activity of the MXR system, causing concentration dependent accumulation of rhodamine 123; while EHMC, OC and HMS had weak MXR inhibition. The IC50 (50 % inhibition concentration) values of 4-MBC, BP-3 and BM-DBM were 23.54, 40.59 and 26.37 μM, respectively, with inhibitory potentials of 23.1, 13.4 and 20.6 % relative to verapamil (VER, a model inhibitor of P-glycoprotein). Our results firstly provide the evidence for UV filters inhibition effect on MXR in aquatic organisms. In addition, it was revealed by molecular docking analysis that the selected six UV filters can occupy the same binding site on T. thermophila P-gp as VER does; and form H-bonds with residues Ser 328 and/or Asn 281. This study raises the awareness of aquatic ecological risk from the organic UV filters exposure, as they would be involved in potentiating toxic effects by chemosensitizing. PMID:27315091

  2. Sedimentary records of δ13C, δ15N and organic matter accumulation in lakes receiving nutrient-rich mine waters

    Organic C and total N concentrations, C/N ratios, δ15N and δ13C values in 210Pb-dated sediment cores were used to reconstruct historical changes in organic matter (OM) accumulation in three Swedish lakes receiving nutrient-rich mine waters. Ammonium-nitrate-based explosives and sodium cyanide (NaCN) used in gold extraction were the major N sources, while lesser amounts of P originated from apatite and flotation chemicals. The software IsoSource was used to model the relative contribution of soil, terrestrial and littoral vegetation, and phytoplankton detritus in the lake sediments. In one lake the IsoSource modelling failed, suggesting the presence of additional, unknown OM sources. In two of the lakes sedimentary detritus of littoral vegetation and phytoplankton had increased by 15–20% and 20–35%, respectively, since ∼ 1950, when N- and P-rich mine waters began to reach the lakes. Today, phytoplankton is the dominating OM component in these lake sediments, which appears to be a eutrophication effect related to mining operations. Changes in the N isotopic composition of biota, lake water, and sediments related to the use of ammonium-nitrate-based explosives and NaCN were evident in the two studied systems. However, N isotope signals in the receiving waters (δ15N ∼ + 9‰ to + 19‰) were clearly shifted from the primary signal in explosives (δ15N–NO3 = + 3.4 ± 0.3‰; δ15N–NH4 = − 8.0 ± 0.3‰) and NaCN (δ15N = + 1.1 ± 0.5‰), and direct tracing of the primary N isotope signals in mining chemicals was not possible in the receiving waters. Systems where mine waters with a well known discharge history are a major point source of N with well-defined isotopic composition should, however, be suitable for further studies of processes controlling N isotope signatures and their transformation in aquatic systems receiving mine waters. - Highlights: • Historical mining-related changes in organic matter accumulation were revealed. • Macrophyte and

  3. Sedimentary records of δ{sup 13}C, δ{sup 15}N and organic matter accumulation in lakes receiving nutrient-rich mine waters

    Widerlund, Anders, E-mail: Anders.Widerlund@ltu.se; Chlot, Sara; Öhlander, Björn

    2014-07-01

    Organic C and total N concentrations, C/N ratios, δ{sup 15}N and δ{sup 13}C values in {sup 210}Pb-dated sediment cores were used to reconstruct historical changes in organic matter (OM) accumulation in three Swedish lakes receiving nutrient-rich mine waters. Ammonium-nitrate-based explosives and sodium cyanide (NaCN) used in gold extraction were the major N sources, while lesser amounts of P originated from apatite and flotation chemicals. The software IsoSource was used to model the relative contribution of soil, terrestrial and littoral vegetation, and phytoplankton detritus in the lake sediments. In one lake the IsoSource modelling failed, suggesting the presence of additional, unknown OM sources. In two of the lakes sedimentary detritus of littoral vegetation and phytoplankton had increased by 15–20% and 20–35%, respectively, since ∼ 1950, when N- and P-rich mine waters began to reach the lakes. Today, phytoplankton is the dominating OM component in these lake sediments, which appears to be a eutrophication effect related to mining operations. Changes in the N isotopic composition of biota, lake water, and sediments related to the use of ammonium-nitrate-based explosives and NaCN were evident in the two studied systems. However, N isotope signals in the receiving waters (δ{sup 15}N ∼ + 9‰ to + 19‰) were clearly shifted from the primary signal in explosives (δ{sup 15}N–NO{sub 3} = + 3.4 ± 0.3‰; δ{sup 15}N–NH{sub 4} = − 8.0 ± 0.3‰) and NaCN (δ{sup 15}N = + 1.1 ± 0.5‰), and direct tracing of the primary N isotope signals in mining chemicals was not possible in the receiving waters. Systems where mine waters with a well known discharge history are a major point source of N with well-defined isotopic composition should, however, be suitable for further studies of processes controlling N isotope signatures and their transformation in aquatic systems receiving mine waters. - Highlights: • Historical mining-related changes in organic

  4. Kuo Pao Kun’s Zheng He Legend and Multicultural Encounters in Singapore

    Rachel Leng

    2016-08-01

    Full Text Available This paper will examine Kuo Pao Kun’s modern reiteration of the Zheng He theme in his 1995 Singaporean play titled Descendants of the Eunuch Admiral 郑和的后代. The memory of Zheng He and his legacy rooted in an anomalous series of sea expeditions makes him unique in Chinese history and speaks to contemporary issues of multiculturalism, ethnic hybridity, and the geopolitics of migration and diaspora. Kuo reappropriates the Zheng He theme to re-present the eunuch admiral as an ancient paradigm of the modern multicultural man in an increasingly transnational world. Scholars have noted the way Kuo uses storytelling to prompt people in Singapore to show a greater willingness to live together as a multiethnic, multicultural, and multilingual nation. However, I argue that the play’s text reveals more somber and personal undercurrents, where Kuo draws upon an intimate understanding of the classical Chinese Zheng He story to record shrewd observations and articulate concealed shafts of criticism about Singapore’s bureaucracy, intermingled with philosophical reflections addressing contemporary Sinophone lived reality.

  5. [/sup 99m/Tc]-HM-PAO SPECT in Parkinson's disease

    Thirty-six patients affected by Parkinson's disease were studied using single photon emission computed tomography (SPECT) and [/sup 99m/Tc]-HM-PAO as a tracer. The scanning procedure was performed 16-24 h after discontinuation of specific therapy. Tracer activity ratios were determined in 10 pairs of cerebellar, cortical, and subcortical regions. Data were compared with those of 10 age-matched controls. Most of the regions examined did not show any relevant change between parkinsonian and control subjects. Notably, mean activity in striatal regions were similar in the two groups. Increased activity in caudate-putamen was found in patients who were on chronic DOPA therapy. Side-to-side asymmetries in the basal ganglia increased with the severity of the disease. Significant reductions of tracer uptake, from control values, were observed bilaterally in the parietal cortex. These deficits were more pronounced in patients with mental deterioration and in subjects who had been chronically treated with anticholinergic drugs. Parietal perfusion deficits in parkinsonian patients resemble those described in Alzheimer's dementia. These findings suggest that the heterogeneous alterations of regional cerebral blood flow (rCBF) in parkinsonian patients reflect the multifactorial pathophysiology of the disease

  6. An examination of historic inorganic sedimentation and organic matter accumulation in several marsh types within the Mobile Bay and and Mobile-Tensaw River Delta region

    Smith, Christopher G.; Osterman, Lisa E.; Poore, Richard Z.

    2013-01-01

    Mass accumulation rates (MAR; g cm-2 y-1), linear sedimentation rates (LSR; cm y-1), and core geochronology derived from excess lead-210 (210Pb) profiles and inventories measured in six sediment cores collected from marsh sites from the MobileTensaw River Delta and Mobile Bay region record the importance of both continuous and event-driven inorganic sedimentation over the last 120 years. MAR in freshwater marshes varied considerably between sites and through time (0.24 and 1.31 g cm-2 y-1). The highest MARs occurred in the 1950s and 1960s and correspond to record discharge events along the Mobile and Tensaw Rivers. In comparison, MAR at salt marsh sites increased almost threefold over the last 120 years (0.05 to 0.18 g cm-2 y-1 or 0.23 to 0.48 cm y-1). From 1880 to 1960, organic accumulation remained fairly constant (20%), while intermittent pulses of high inorganic sedimentation were observed following 1960. The pulses in inorganic sedimentation coincide with several major hurricanes (e.g., Hurricanes Camille, Fredric, Georges, and Ivan). The nearly threefold increase in MAR in salt marshes during the last 120 years would thus appear to be partially dependent on inorganic sedimentation from storm events. This study shows that while hurricanes, floods, and other natural hazards are well-known threats to human infrastructure and coastal ecosystems, these events also transport sediment to marshes that help abate other pressures such as sea-level rise (SLR) and subsidence.

  7. Intraoperative PaO2 is not related to the development of surgical site infections after major cardiac surgery

    Fierro Inma

    2011-01-01

    Full Text Available Abstract Background The perioperative use of high inspired oxygen fraction (FIO2 for preventing surgical site infections (SSIs has demonstrated a reduction in their incidence in some types of surgery however there exist some discrepancies in this respect. The aim of this study was to analyze the relationship between PaO2 values and SSIs in cardiac patients. Methods We designed a prospective study in which 1,024 patients undergoing cardiac surgery were analyzed. Results SSIs were observed in 5.3% of patients. There was not significant difference in mortality at 30 days between patients with and without SSIs. In the uni and multivariate analysis no differences in function of the inspired oxygen fraction administrated were observed. Conclusions We observed that the PaO2 in adult cardiac surgery patients was not related to SSI rate.

  8. Analysis of physiological (pao/sub 2/, pulse and blood pressure) changes during modified ect under general anaesthesia

    To study the changes in physiological parameters i e PAO2, pulse and blood pressure changes during ECT under GA. Study Design: Quasi-experimental study. Place and Duration of Study: Department of Psychiatry and Department of Anaesthesiology, Combined Military Hospital Abbottabad from Sep 2009 to Feb 2010. Patients and Methods: A total of 50 patients with depression were given four separate ECT sessions each. All patients were anaesthetized using propofol 180-200 mg I/V and suxamethonium 50 mg i e 0.75-1 mg per kg I/V without atropine. They were stratified according to physiological changes including PAO2, pulse and blood pressure at 1, 2 and 5 min after ECT. Oxygen saturation was measured using a pulse oximeter, which measures saturations in the range of 65-100%. Results: Age range was 19-65 years; mean 46 years (SD+-13). Mean diastolic BP before ECT was 84.72 that decreased post ECT ie 78.02 and 77.46 and 74.44 at interval of 1, 2 and 5 minute respectively. Post-ECT pulse and PAO2 behaved similarly. Post ECT systolic BP decreased at 1 and 5 minutes. Pulse rate decreased after ECT. Conclusion: ECT under propofol is one of the most effective and safe modality of treatment for psychiatric patients under the supervision of qualified psychiatrists and anaesthesiologists and it gives more stable hemodynamic changes. (author)

  9. Comparison of technetium-99m-HM-PAO leukocytes with indium-111-oxine leukocytes for localizing intraabdominal sepsis

    Technetium-99m-HM-PAO [(99mTc]HM-PAO) leukocyte and indium-111-oxine (111In-oxine) leukocyte scanning were carried out simultaneously in 41 patients at 4 hr and 24 hr after reinjection to determine whether the 4-hr 99mTc scan could replace the 24-hr 111In scan for detecting intraabdominal sepsis. Abdominal infection was confirmed in 12 cases. The 4-hr 99Tc-leukocyte scan, the 4-hr 111In-leukocyte scan, and the 24-hr 111In-leukocyte scan yielded a sensitivity of 100%, 67%, and 100%, respectively, and a specificity of 62%, 90%, and 86%, respectively. The 24-hr 99mTc-leukocyte scan also produced a sensitivity of 100%, but it was falsely positive in all 29 cases without infection due to physiologic bowel uptake. False-positive 4-hr 99mTc-leukocyte scans were also produced by physiologic bowel uptake in seven cases all of whom had true-negative 4-hr and 24-hr 111In-leukocyte scans. Because of the high incidence of false-positive 4-hr [99mTc]HM-PAO leukocyte scans, it was concluded that they could not replace 24-hr 111In-leukocyte scans for detecting intraabdominal sepsis, and that serial 99mTc leukocyte scans starting earlier than 4 hr after reinjection must be evaluated

  10. A Study on Replacement of HEPA Filter In-place Leak Test Challenge Agent from DOP to PAO in NPP

    Atmosphere cleanup system of nuclear power plants is a gas waste treatment system to minimize the leakage of radioactive materials produced during normal operation and accidents. The HEPA(High Efficiency Particulate Air) filter in this system has the major role to filter the particulate radioactive materials. The leak test method of HEPA filter conforms to the Reg. Guide 1.140 and Reg. Guide 1.52 of USNRC, which were both revised in 2001. The revisions include the permission of alternative challenging aerosol agents besides DOP (dioctyl phthalate) for HEPA filter in-place leak test. US DOE is demanding to stop using DOP since DOP was suspected as a carcinogen. Currently, industries other than nuclear power plants mostly use PAO (polyalpha olefin) as HEPA filter leak test challenge aerosol agent. Due to Reg. Guide 1.140(Rev.2) and 1.52(Rev.2), only DOP has been allowed to be used in nuclear power plants. As a result, nuclear power plant workers have been exposed to mental and physical risks whenever there is HEPA filter in-place leak test. In this paper, the leak test results using DOP and PAO are compared to verify that DOP can be replaced with non-carcinogenic PAO for HEPA filter leak test in nuclear power plants

  11. A Study on Replacement of HEPA Filter In-place Leak Test Challenge Agent from DOP to PAO in NPP

    Lee, S. K.; Kim, K.; Sohn, S. H. [KEPRI, Daejeon (Korea, Republic of); Bae, J. C.; Park, J. S.; Cho, B. H. [KHNP, Yonggwang (Korea, Republic of); Yu, B. J. [KPS, Yonggwang (Korea, Republic of); Hong, S. J. [FNC Tech. Co. Ltd., Seoul (Korea, Republic of); Kang, S. H. [KFTL, Gwangju (Korea, Republic of)

    2008-10-15

    Atmosphere cleanup system of nuclear power plants is a gas waste treatment system to minimize the leakage of radioactive materials produced during normal operation and accidents. The HEPA(High Efficiency Particulate Air) filter in this system has the major role to filter the particulate radioactive materials. The leak test method of HEPA filter conforms to the Reg. Guide 1.140 and Reg. Guide 1.52 of USNRC, which were both revised in 2001. The revisions include the permission of alternative challenging aerosol agents besides DOP (dioctyl phthalate) for HEPA filter in-place leak test. US DOE is demanding to stop using DOP since DOP was suspected as a carcinogen. Currently, industries other than nuclear power plants mostly use PAO (polyalpha olefin) as HEPA filter leak test challenge aerosol agent. Due to Reg. Guide 1.140(Rev.2) and 1.52(Rev.2), only DOP has been allowed to be used in nuclear power plants. As a result, nuclear power plant workers have been exposed to mental and physical risks whenever there is HEPA filter in-place leak test. In this paper, the leak test results using DOP and PAO are compared to verify that DOP can be replaced with non-carcinogenic PAO for HEPA filter leak test in nuclear power plants.

  12. Dictyostelium transcriptional responses to Pseudomonas aeruginosa: common and specific effects from PAO1 and PA14 strains

    Martinez José L

    2008-06-01

    Full Text Available Abstract Background Pseudomonas aeruginosa is one of the most relevant human opportunistic bacterial pathogens. Two strains (PAO1 and PA14 have been mainly used as models for studying virulence of P. aeruginosa. The strain PA14 is more virulent than PAO1 in a wide range of hosts including insects, nematodes and plants. Whereas some of the differences might be attributable to concerted action of determinants encoded in pathogenicity islands present in the genome of PA14, a global analysis of the differential host responses to these P. aeruginosa strains has not been addressed. Little is known about the host response to infection with P. aeruginosa and whether or not the global host transcription is being affected as a defense mechanism or altered in the benefit of the pathogen. Since the social amoeba Dictyostelium discoideum is a suitable host to study virulence of P. aeruginosa and other pathogens, we used available genomic tools in this model system to study the transcriptional host response to P. aeruginosa infection. Results We have compared the virulence of the P. aeruginosa PAO1 and PA14 using D. discoideum and studied the transcriptional response of the amoeba upon infection. Our results showed that PA14 is more virulent in Dictyostelium than PA01using different plating assays. For studying the differential response of the host to infection by these model strains, D. discoideum cells were exposed to either P. aeruginosa PAO1 or P. aeruginosa PA14 (mixed with an excess of the non-pathogenic bacterium Klebsiella aerogenes as food supply and after 4 hours, cellular RNA extracted. A three-way comparison was made using whole-genome D. discoideum microarrays between RNA samples from cells treated with the two different strains and control cells exposed only to K. aerogenes. The transcriptomic analyses have shown the existence of common and specific responses to infection. The expression of 364 genes changed in a similar way upon infection with

  13. Effects of chloride, sulfate and natural organic matter (NOM) on the accumulation and release of trace-level inorganic contaminants from corroding iron.

    Peng, Ching-Yu; Ferguson, John F; Korshin, Gregory V

    2013-09-15

    This study examined effects of varying levels of anions (chloride and sulfate) and natural organic matter (NOM) on iron release from and accumulation of inorganic contaminants in corrosion scales formed on iron coupons exposed to drinking water. Changes of concentrations of sulfate and chloride were observed to affect iron release and, in lesser extent, the retention of representative inorganic contaminants (vanadium, chromium, nickel, copper, zinc, arsenic, cadmium, lead and uranium); but, effects of NOM were more pronounced. DOC concentration of 1 mg/L caused iron release to increase, with average soluble and total iron concentrations being four and two times, respectively, higher than those in the absence of NOM. In the presence of NOM, the retention of inorganic contaminants by corrosion scales was reduced. This was especially prominent for lead, vanadium, chromium and copper whose retention by the scales decreased from >80% in the absence of NOM to copper, chromium, zinc and nickel retained on the surface of iron coupons in the presence of DOC largely retained their mobility and were released readily when ambient water chemistry changed. Vanadium, arsenic, cadmium, lead and uranium retained by the scales were largely unsusceptible to changes of NOM and chloride levels. Modeling indicated that the observed effects were associated with the formation of metal-NOM complexes and effects of NOM on the sorption of the inorganic contaminants on solid phases that are typical for iron corrosion in drinking water. PMID:23863395

  14. 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

  15. 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.

  16. Significant accumulation of persistent organic pollutants and dysregulation in multiple DNA damage repair pathways in the electronic-waste-exposed populations

    Electronic waste (e-waste) has created a worldwide environmental and health problem, by generating a diverse group of hazardous compounds such as persistent organic pollutants (POPs). Our previous studies demonstrated that populations from e-waste exposed region have a significantly higher level of chromosomal aberrancy and incidence of DNA damage. In this study, we further demonstrated that various POPs persisted at a significantly higher concentration in the exposed group than those in the unexposed group. The level of reactive oxygen species and micronucleus rate were also significantly elevated in the exposed group. RNA sequencing analysis revealed 31 genes in DNA damage responses and repair pathways that were differentially expressed between the two groups (Log 2 ratio >1 or <−1). Our data demonstrated that both females and males of the exposed group have activated a series of DNA damage response genes; however many important DNA repair pathways have been dysregulated. Expressions of NEIL1/3 and RPA3, which are critical in initiating base pair and nucleotide excision repairs respectively, have been downregulated in both females and males of the exposed group. In contrast, expression of RNF8, an E3 ligase involved in an error prone non-homologous end joining repair for DNA double strand break, was upregulated in both genders of the exposed group. The other genes appeared to be differentially expressed only when the males or females of the two groups were compared respectively. Importantly, the expression of cell cycle regulatory gene CDC25A that has been implicated in multiple kinds of malignant transformation was significantly upregulated among the exposed males while downregulated among the exposed females. In conclusion, our studies have demonstrated significant correlations between e-waste disposing and POPs accumulation, DNA lesions and dysregulation of multiple DNA damage repair mechanisms in the residents of the e-waste exposed region. - Highlights:

  17. Significant accumulation of persistent organic pollutants and dysregulation in multiple DNA damage repair pathways in the electronic-waste-exposed populations

    He, Xiaobo; Jing, Yaqing; Wang, Jianhai; Li, Keqiu [Basic Medical College, Tianjin Medical University, Tianjin 300070 (China); Yang, Qiaoyun [Department of Occupational and Environmental Health, School of Public Health, Tianjin Medical University, Tianjin 300070 (China); Zhao, Yuxia [Basic Medical College, Tianjin Medical University, Tianjin 300070 (China); Li, Ran [State Key Joint Laboratory for Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering and Center for Environment and Health, Peking University, Beijing 100871 (China); Ge, Jie [Department of Breast Surgery, Tianjin Medical University Cancer Institute and Hospital, Tianjin 300060 (China); Key Laboratory of Breast Cancer Prevention and Treatment of the Ministry of Education, Tianjin Medical University Cancer Institute and Hospital, Tianjin 300060 (China); Qiu, Xinghua, E-mail: xhqiu@pku.edu.cn [State Key Joint Laboratory for Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering and Center for Environment and Health, Peking University, Beijing 100871 (China); Li, Guang, E-mail: lig@tijmu.edu.cn [Basic Medical College, Tianjin Medical University, Tianjin 300070 (China)

    2015-02-15

    Electronic waste (e-waste) has created a worldwide environmental and health problem, by generating a diverse group of hazardous compounds such as persistent organic pollutants (POPs). Our previous studies demonstrated that populations from e-waste exposed region have a significantly higher level of chromosomal aberrancy and incidence of DNA damage. In this study, we further demonstrated that various POPs persisted at a significantly higher concentration in the exposed group than those in the unexposed group. The level of reactive oxygen species and micronucleus rate were also significantly elevated in the exposed group. RNA sequencing analysis revealed 31 genes in DNA damage responses and repair pathways that were differentially expressed between the two groups (Log 2 ratio >1 or <−1). Our data demonstrated that both females and males of the exposed group have activated a series of DNA damage response genes; however many important DNA repair pathways have been dysregulated. Expressions of NEIL1/3 and RPA3, which are critical in initiating base pair and nucleotide excision repairs respectively, have been downregulated in both females and males of the exposed group. In contrast, expression of RNF8, an E3 ligase involved in an error prone non-homologous end joining repair for DNA double strand break, was upregulated in both genders of the exposed group. The other genes appeared to be differentially expressed only when the males or females of the two groups were compared respectively. Importantly, the expression of cell cycle regulatory gene CDC25A that has been implicated in multiple kinds of malignant transformation was significantly upregulated among the exposed males while downregulated among the exposed females. In conclusion, our studies have demonstrated significant correlations between e-waste disposing and POPs accumulation, DNA lesions and dysregulation of multiple DNA damage repair mechanisms in the residents of the e-waste exposed region. - Highlights:

  18. Soil Organic Carbon Accumulation Increases Percentage of Soil Olsen-P to Total P at Two 15-Year Mono-Cropping Systems in Northern China

    SHEN Pu; XIAO Hou-jun; HE Xin-hua; XU Ming-gang; ZHANG Hui-min; PENG Chang; GAO Hong-jun; LIU Hua; XU Yong-mei; QIN Song

    2014-01-01

    Soil organic carbon (SOC) and soil Olsen-P are key soil fertility indexes but information on their relationships is limited particularly under long-term fertilization. We investigated the relationships between SOC and the percentage of soil Olsen-P to total P (PSOPTP) under six different 15-yr (1990-2004) long-term fertilizations at two cropping systems in northern China. These fertilization treatments were (1) unfertilized control (control);(2) chemical nitrogen (N);(3) N plus chemical P (NP);(4) NP plus chemical potassium (NPK);(5) NPK plus animal manure (NPKM) and (6) high NPKM (hNPKM). Compared with their initial values in 1989 at both sites, during the 11th to 15th fertilization years annual mean SOC contents were signiifcantly increased by 39.4-47.0%and 58.9-93.9%at Gongzhuling, Jilin Province, and Urumqi, Xinjiang, China, under the two NPKM fertilizations, respectively, while no signiifcant changes under the no-P or chemical P fertilization. During the 11th to 15th fertilization years, annual mean PSOPTP was respectively increased by 2.6-4.2 and 5.8-14.1 times over the initial values under the two chemical P fertilizations and the two NPKM fertilizations, but was unchanged in their initial levels under the two no-P fertilizations at both sites. Over the 15-yr long-term fertilization SOC signiifcantly positively correlated with PSOPTP (r2=0.55-0.79, P<0.01). We concluded that the combination of chemical P plus manure is an effective way to promote SOC accumulation and the percentage of soil Olsen-P to total P at the two mono-cropping system sites in northern China.

  19. Single photon emission tomography using sup(99m)Tc-HM-PAO in the investigation of dementia

    Single photon emission tomographic imaging of the brain using sup(99m)Tc HM-PAO was carried out in patients with a clinical diagnosis of Alzheimer's disease, non-Alzheimer frontal-lobe dementia, and progressive supranuclear palsy. Independent assessment of reductions in uptake revealed posterior hemisphere abnormalities in the majority of the Alzheimer group, and selective anterior hemisphere abnormalities in both other groups. The findings were consistent with observed patterns of mental impairment. The imaging technique has potential value in the differential diagnosis of primary cerebral atrophy. (author)

  20. Single photon emission tomography using sup(99m)Tc-HM-PAO in the investigation of dementia

    Neary, D.; Snowden, J.S.; Shields, R.A.; Burjan, A.W.I.; Northen, B.; Macdermott, N.; Prescott, M.C.; Testa, H.J.

    1987-09-01

    Single photon emission tomographic imaging of the brain using sup(99m)Tc HM-PAO was carried out in patients with a clinical diagnosis of Alzheimer's disease, non-Alzheimer frontal-lobe dementia, and progressive supranuclear palsy. Independent assessment of reductions in uptake revealed posterior hemisphere abnormalities in the majority of the Alzheimer group, and selective anterior hemisphere abnormalities in both other groups. The findings were consistent with observed patterns of mental impairment. The imaging technique has potential value in the differential diagnosis of primary cerebral atrophy.

  1. Expression, purification, crystallization and preliminary crystallographic analysis of PA3885 (TpbA) from Pseudomonas aeruginosa PAO1

    PA3885 (TpbA), a tyrosine phosphatase, may function as a balancing factor between biofilm formation and motility in the opportunistic pathogen P. aeruginosa. Here, the expression, purification, crystallization and preliminary crystallographic analysis of PA3885 from P. aeruginosa PAO1 are reported. Biofilms are important in cell communication and growth in most bacteria and are also responsible for most human clinical infections and diseases. Quorum-sensing systems have been identified to be crucial for biofilm formation and regulation. PA3885 (TpbA), a tyrosine phosphatase, is reported to convert extracellular quorum-sensing signals into internal gene-cascade reactions that result in reduced biofilm formation in the opportunistic pathogen Pseudomonas aeruginosa. Here, PA3885 from P. aeruginosa PAO1 was expressed, purified and crystallized. Single crystals were studied by X-ray crystallography and native diffraction data were collected to 2.8 Å resolution. These crystals were determined to belong to space group C2. It was not possible to conclusively determine the number of proteins in the asymmetric unit from the preliminary X-ray diffraction data analysis alone and attempts to determine the crystal structure of PA3885 are currently under way

  2. The Sinbad retrotransposon from the genome of the human blood fluke, Schistosoma mansoni, and the distribution of related Pao-like elements

    Morales Maria E

    2005-02-01

    Full Text Available Abstract Background Of the major families of long terminal repeat (LTR retrotransposons, the Pao/BEL family is probably the least well studied. It is becoming apparent that numerous LTR retrotransposons and other mobile genetic elements have colonized the genome of the human blood fluke, Schistosoma mansoni. Results A proviral form of Sinbad, a new LTR retrotransposon, was identified in the genome of S. mansoni. Phylogenetic analysis indicated that Sinbad belongs to one of five discreet subfamilies of Pao/BEL like elements. BLAST searches of whole genomes and EST databases indicated that members of this clade occurred in species of the Insecta, Nematoda, Echinodermata and Chordata, as well as Platyhelminthes, but were absent from all plants, fungi and lower eukaryotes examined. Among the deuterostomes examined, only aquatic species harbored these types of elements. All four species of nematode examined were positive for Sinbad sequences, although among insect and vertebrate genomes, some were positive and some negative. The full length, consensus Sinbad retrotransposon was 6,287 bp long and was flanked at its 5'- and 3'-ends by identical LTRs of 386 bp. Sinbad displayed a triple Cys-His RNA binding motif characteristic of Gag of Pao/BEL-like elements, followed by the enzymatic domains of protease, reverse transcriptase (RT, RNAseH, and integrase, in that order. A phylogenetic tree of deduced RT sequences from 26 elements revealed that Sinbad was most closely related to an unnamed element from the zebrafish Danio rerio and to Saci-1, also from S. mansoni. It was also closely related to Pao from Bombyx mori and to Ninja of Drosophila simulans. Sinbad was only distantly related to the other schistosome LTR retrotransposons Boudicca, Gulliver, Saci-2, Saci-3, and Fugitive, which are gypsy-like. Southern hybridization and bioinformatics analyses indicated that there were about 50 copies of Sinbad in the S. mansoni genome. The presence of ESTs

  3. On the accumulation of organic matter on the southeastern Brazilian continental shelf: a case study based on a sediment core from the shelf off Rio de Janeiro

    Renato da Silva Carreira

    2012-03-01

    Full Text Available Sterol and fatty acid biomarkers and isotopic composition (δ13C and δ15N of bulk organic matter (OM were quantified in a sediment core to characterize the accumulation of autochthonous OM in an area on the continental shelf adjacent to Rio de Janeiro State. In the sediment surface (0-1 cm the concentration of total sterols and fatty acids was at least one order of magnitude higher than that measured deeper down in the core and was dominated by labile and planktonic-derived biomarker compounds. These results suggest, as is confirmed by multivariate statistical analysis, the occurrence of an event of enhanced primary production in the water column and efficient export of particles to the bottom. Similar conditions have been observed at Cabo Frio, located 150 km to the north of our study site, during an upwelling event, suggesting that such events may exert a regional influence on primary production on the south-eastern Brazilian continental shelf. Beyond the signatures from this event, the presence of biomarker compounds from vascular plants suggests the additional influence of an outflow from Guanabara Bay at the study site. These results point to the need for further investigation of the relative influence of physical forcings and continental inputs on the biogeochemical processes on the section of the continental shelf considered in the present study.Marcadores moleculares na classe de lipídios (esterois, ácidos graxos e hidrocarbonetos e a composição isotópica (δ13C e δ15N da matéria orgânica bruta foram quantificados em amostras de um testemunho de sedimento para caracterizar o histórico recente de sedimentação da matéria orgânica na plataforma continental adjacente à Baía de Guanabara, no Estado do Rio de Janeiro. Na superfície do sedimento (0-1 cm, a concentração total de esterois e ácidos graxos foi cerca de uma ordem de grandeza maior do que observado nas camadas mais profundas do sedimento, com predominância de lip

  4. Influence of organic selenium supplementation on the accumulation of toxic and essential trace elements involved in the antioxidant system of chicken

    Pappas, Athanasios C; Zoidis, Evangelos; Georgiou, Constantinos A.; Demiris, Nikolaos; Surai, Peter F; Fegeros, Konstantinos

    2011-01-01

    Abstract The aim of the study was to investigate the interactions between selenium (Se) and some trace elements, both toxic and essential, which are all involved in the antioxidant system. A total of 128 day-old chickens (Gallus gallus, broilers) were used to investigate the effect of Se yeast supplementation on the accumulation of cadmium (Cd), copper (Cu) iron (Fe) and zinc (Zn). There were 4 replicates of 4 dietary treatments: T1 (basal diet with no added Se, analyzed to contain...

  5. Disentangling direct and indirect effects of water table drawdown on above and belowground plant litter decomposition: Consequences for accumulation of organic matter in boreal peatlands.

    Strakova, Petra; PenttilÀ, Timo; Laine, Jukka; Laiho, Raija

    2012-01-01

    Pristine peatlands are carbon (C) accumulating wetland ecosystems sustained by a high water table (WT) and consequent anoxia that slows down decomposition. Persistent WT drawdown as a response to climate and/or land-use change affects decomposition either directly through environmental factors such as increased oxygenation, or indirectly through changes in plant community composition. This study attempts to disentangle the direct and indirect effects of WT drawdown by measuring the relative i...

  6. The effect of drainage on organic matter accumulation and plant communities of high-altitude peatlands in the Colombian tropical Andes

    J.C. Benavides

    2014-04-01

    Full Text Available The tropical Andes store and regulate water outflow that serves nearly 60 million people. Most of the water is for un-managed agricultural irrigation. In this work I report how the drainage of peatlands has adversely affected the development of plant communities and recent carbon accumulation in a páramo massif at 2500 to 3800 m altitude in the northern Andes. I surveyed vegetation and water chemistry in 26 peatlands with differing intensities of drainage. Peat cores to 50 cm from two sites with contrasting drainage histories were dated using 210Pb, and used to compare historical vegetation changes and carbon accumulation rates. (A Species composition was much affected by drainage, which resulted in a reduction in cover of Sphagnum and other peat-forming species, and the encroachment of sedges and Juncus effusus. The ability of peat to store water and carbon was also reduced in drained peatlands. Vegetation records show a shift towards sedge-Juncus communities around 50 years ago when agricultural use of water increased. (B Peat and carbon accumulation rates were lower in drained sites, indicating either greater decomposition rates of the upper peat column or lower production by the changed plant communities. The ecological services offered by peatlands to agrarian communities downstream are important. Measures to prevent peatland destruction are needed urgently.

  7. Antipathogenic potential of marine Bacillus sp. SS4 on N-acyl-homoserine-lactone-mediated virulence factors production in Pseudomonas aeruginosa (PAO1)

    K Syed Musthafa; V Saroja; S Karutha Pandian; A Veera Ravi

    2011-03-01

    Antipathogenic therapy is an outcome of the quorum-sensing inhibition (QSI) mechanism, which targets autoinducer-dependent virulent gene expression in bacterial pathogens. -acyl homoserine lactone (AHL) acts as a key regulator in the production of virulence factors and biofilm formation in Pseudomonas aeruginosa PAO1 and violacein pigment production in Chromobacterium violaceum. In the present study, the marine bacterial strain SS4 showed potential QSI activity in a concentration-dependent manner (0.5–2 mg/ml) against the AHL-mediated violacein production in C. violaceum (33–86%) and biofilm formation (33–88%), total protease (20–65%), LasA protease (59–68%), LasB elastase (36–68%), pyocyanin (17–86%) and pyoverdin productions in PAO1. The light and confocal laser scanning microscopic analyses confirmed the reduction of the biofilm-forming ability of PAO1 when treated with SS4 extract. Furthermore, the antibiofilm potential was confirmed through static biofilm ring assay, in which ethyl acetate extract of SS4 showed concentration-dependent reduction in the biofilm-forming ability of PAO1. Thus, the result of this study clearly reveals the antipathogenic and antibiofilm properties of the bacterial isolate SS4. Through 16S rDNA analysis, the strain SS4 was identified as Bacillus sp. (GenBank Accession Number: GU471751).

  8. Accumulation of dioxins and PCB in house fly larvae (musca domestica) reared in poultry manure and used in feed for organic laying hens

    Nordentoft, Steen; Cederberg, Tommy Licht; Fischer, Christian Holst;

    2014-01-01

    A challenging aspect of organic egg and meat production is provision of a balanced nutrient supply. Some essential amino acids are difficult to provide in sufficient quantities in organic feed and undersupply may lead tolower egg production, slower growth and even cannibalism. Due to these problems...... it is accepted in EU regulations to balance the feed formula by use of synthetic amino acids in the organic production until improved organic sources of amino acids can be provided. In nature insects and insect larvae are important food sources for poultry and the larva of the common house fly (Musca...... domestica) have been shown to be especially rich in the required essential amino and fatty acids. In Northern Europe the larvae can easily be grown in poultry manure locally on the farm where it may be used as a new organic high value protein and fat source for poultry. Eggs from free range hens have...

  9. Biological significance of [14C]phenol accumulation in different organs of a murrel, Channa punctatus, and the common carp, Cyprinus carpio

    Phenol, a ubiquitous component of industrial effluents, is a common pollutant of water resources and a serious threat to fish. The present work demonstrates that a significant amount of phenol is retained by various tissues of the common carp, Cyprinus carpio, and the snake-headed murrel, Channa punctatus. The rate of [14C]phenol accumulation was higher carp than in the murrel. It is suggested that retention of phenol in the brain and ovary may seriously affect the reproductive potential of the fish

  10. A software program for quantitative analysis of alveolar oxygen partial pressure (pAO2) with oxygen-sensitive 3He-MRI

    Purpose: To develop a software tool for quantitative analysis of alveolar oxygen partial pressure (pAO2) as well as its time course during apnea. Material and Methods: T1-relaxation times of hyperpolarized 3He are reduced by paramagnetic oxygen rendering 3He-MRI sensitive to oxygen and thus allowing the assessment of the local oxygen partial pressure in the pulmonary airspaces. Oxygen-related relaxation and loss of polarization by RF-excitation can be discriminated by acquiring two image series with varying interscan delay and/or flip angles. Software was developed to calculate the pAO2 and the decay rate in user-defined regions of interest (ROIs) automatically. Moreover, parameter maps can be calculated. In addition to the analysis of 2-dimensional data sets, the software allows the evaluation of 3-dimensional measurements for the first time. Artifacts due to lung motion were reduced by implementing a motion correction algorithm. Results: The software was successfully applied to data sets from healthy volunteers and from patients with various lung diseases. The parameter maps demonstrated a more homogeneous distribution of pAO2 for the volunteers than for the patients. A regional increase in pAO2 was found in a few patients. Conclusion: the described software allows the absolute quantification of pAO2 as well as its variation over time. In the future therefore, the software may gain importance for detecting mis-matches between ventilation and perfusion, e.g., in patients with pulmonary embolism or chronic obstructive lung diseases. (orig.)