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Sample records for abundant organic acids

  1. Acyl homoserine lactone changes the abundance of proteins and the levels of organic acids associated with stationary phase in Salmonella Enteritidis.

    PubMed

    de Almeida, Felipe Alves; Pimentel-Filho, Natan de Jesus; Carrijo, Lanna Clícia; Bento, Cláudia Braga Pereira; Baracat-Pereira, Maria Cristina; Pinto, Uelinton Manoel; de Oliveira, Leandro Licursi; Vanetti, Maria Cristina Dantas

    2017-01-01

    Quorum sensing (QS) is cell-cell communication mechanism mediated by signaling molecules known as autoinducers (AIs) that lead to differential gene expression. Salmonella is unable to synthesize the AI-1 acyl homoserine lactone (AHL), but is able to recognize AHLs produced by other microorganisms through SdiA protein. Our study aimed to evaluate the influence of AI-1 on the abundance of proteins and the levels of organic acids of Salmonella Enteritidis. The presence of N-dodecyl-homoserine lactone (C12-HSL) did not interfere on the growth or the total amount of extracted proteins of Salmonella. However, the abundance of the proteins PheT, HtpG, PtsI, Adi, TalB, PmgI (or GpmI), Eno, and PykF enhanced while the abundance of the proteins RplB, RplE, RpsB, Tsf, OmpA, OmpC, OmpD, and GapA decreased when Salmonella Enteritidis was anaerobically cultivated in the presence of C12-HSL. Additionally, the bacterium produced less succinic, lactic, and acetic acids in the presence of C12-HSL. However, the concentration of extracellular formic acid reached 20.46 mM after 24 h and was not detected when the growth was in the absence of AI-1. Considering the cultivation period for protein extraction, their abundance, process and function, as well as the levels of organic acids, we observed in cells cultivated in presence of C12-HSL a correlation with what is described in the literature as entry into the stationary phase of growth, mainly related to nitrogen and amino acid starvation and acid stress. Further studies are needed in order to determine the specific role of the differentially abundant proteins and extracellular organic acids secreted by Salmonella in the presence of quorum sensing signaling molecules.

  2. The use of amino acid indices for assessing organic matter quality and microbial abundance in deep-sea Antarctic sediments of IODP Expedition 318

    USGS Publications Warehouse

    Carr, Stephanie A; Mills, Christopher; Mandernack, Kevin W

    2016-01-01

    The Adélie Basin, located offshore of the Wilkes Land margin, experiences unusually high sedimentation rates (~ 2 cm yr− 1) for the Antarctic coast. This study sought to compare depthwise changes in organic matter (OM) quantity and quality with changes in microbial biomass with depth at this high-deposition site and an offshore continental margin site. Sediments from both sites were collected during the International Ocean Drilling (IODP) Program Expedition 318. Viable microbial biomass was estimated from concentrations of bacterial-derived phospholipid fatty acids, while OM quality was assessed using four different amino acid degradation proxies. Concentrations of total hydrolysable amino acids (THAA) measured from the continental margin suggest an oligotrophic environment, with THAA concentrations representing only 2% of total organic carbon with relative proportions of non-protein amino acids β-alanine and γ-aminobutyric acid as high as 40%. In contrast, THAA concentrations from the near-shore Adélie Basin represent 40%–60% of total organic carbon. Concentrations of β-alanine and γ-aminobutyric acid were often below the detection limit and suggest that the OM of the basin as labile. DI values in surface sediments at the Adélie and margin sites were measured to be + 0.78 and − 0.76, reflecting labile and more recalcitrant OM, respectively. Greater DI values in deeper and more anoxic portions of both cores correlated positively with increased relative concentrations of phenylalanine plus tyrosine and may represent a change of redox conditions, rather than OM quality. This suggests that DI values calculated along chemical profiles should be interpreted with caution. THAA concentrations, the percentage of organic carbon (CAA%) and total nitrogen (NAA%) represented by amino acids at both sites demonstrated a significant positive correlation with bacterial abundance estimates. These data suggest that the selective degradation of amino acids, as

  3. Comparing Amino Acid Abundances and Distributions Across Carbonaceous Chondrite Groups

    NASA Technical Reports Server (NTRS)

    Burton, Aaron S.; Callahan, Michael P.; Glavin, Daniel P.; Elsila, Jamie E.; Dworkin, Jason P.

    2012-01-01

    Meteorites are grouped according to bulk properties such as chemical composition and mineralogy. These parameters can vary significantly among the different carbonaceous chondrite groups (CI, CM, CO, CR, CH, CB, CV and CK). We have determined the amino acid abundances of more than 30 primary amino acids in meteorites from each of the eight groups, revealing several interesting trends. There are noticeable differences in the structural diversity and overall abundances of amino acids between meteorites from the different chondrite groups. Because meteorites may have been an important source of amino acids to the prebiotic Earth and these organic compounds are essential for life as we know it, the observed variations of these molecules may have been important for the origins of life.

  4. Constraints on hydrocarbon and organic acid abundances in hydrothermal fluids at the Von Damm vent field, Mid-Cayman Rise (Invited)

    NASA Astrophysics Data System (ADS)

    McDermott, J. M.; Seewald, J.; German, C. R.; Sylva, S. P.

    2013-12-01

    The generation of organic compounds in vent fluids has been of interest since the discovery of seafloor hydrothermal systems, due to implications for the sustenance of present-day microbial populations and their potential role in the origin of life on early Earth. Possible sources of organic compounds in hydrothermal systems include microbial production, thermogenic degradation of organic material, and abiotic synthesis. Abiotic organic synthesis reactions may occur during active circulation of seawater-derived fluids through the oceanic crust or within olivine-hosted fluid inclusions containing carbon-rich magmatic volatiles. H2-rich end-member fluids at the Von Damm vent field on the Mid-Cayman Rise, where fluid temperatures reach 226°C, provide an exciting opportunity to examine the extent of abiotic carbon transformations in a highly reducing system. Our results indicate multiple sources of carbon compounds in vent fluids at Von Damm. An ultramafic-influenced hydrothermal system located on the Mount Dent oceanic core complex at 2350 m depth, Von Damm vent fluids contain H2, CH4, and C2+ hydrocarbons in high abundance relative to basalt-hosted vent fields, and in similar abundance to other ultramafic-hosted systems, such as Rainbow and Lost City. The CO2 content and isotopic composition in end-member fluids are virtually identical to bottom seawater, suggesting that seawater DIC is unchanged during hydrothermal circulation of seawater-derived fluids. Accordingly, end-member CH4 that is present in slightly greater abundance than CO2 cannot be generated from reduction of aqueous CO2 during hydrothermal circulation. We postulate that CH4 and C2+ hydrocarbons that are abundantly present in Von Damm vent fluids reflect leaching of fluids from carbon- and H2-rich fluid inclusions hosted in plutonic rocks. Geochemical modeling of carbon speciation in the Von Damm fluids suggests that the relative abundances of CH4, C2+ hydrocarbons, and CO2 are consistent with

  5. Characterization of relative abundance of lactic acid bacteria species in French organic sourdough by cultural, qPCR and MiSeq high-throughput sequencing methods.

    PubMed

    Michel, Elisa; Monfort, Clarisse; Deffrasnes, Marion; Guezenec, Stéphane; Lhomme, Emilie; Barret, Matthieu; Sicard, Delphine; Dousset, Xavier; Onno, Bernard

    2016-12-19

    In order to contribute to the description of sourdough LAB composition, MiSeq sequencing and qPCR methods were performed in association with cultural methods. A panel of 16 French organic bakers and farmer-bakers were selected for this work. The lactic acid bacteria (LAB) diversity of their organic sourdoughs was investigated quantitatively and qualitatively combining (i) Lactobacillus sanfranciscensis-specific qPCR, (ii) global sequencing with MiSeq Illumina technology and (iii) molecular isolates identification. In addition, LAB and yeast enumeration, pH, Total Titratable Acidity, organic acids and bread specific volume were analyzed. Microbial and physico-chemical data were statistically treated by Principal Component Analysis (PCA) and Hierarchical Ascendant Classification (HAC). Total yeast counts were 6 log10 to 7.6 log10CFU/g while LAB counts varied from 7.2 log10 to 9.6 log10CFU/g. Values obtained by L. sanfranciscensis-specific qPCR were estimated between 7.2 and 10.3 log10CFU/g, except for one sample at 4.4 log10CFU/g. HAC and PCA clustered the sixteen sourdoughs into three classes described by their variables but without links to bakers' practices. L. sanfranciscensis was the dominant species in 13 of the 16 sourdoughs analyzed by Next Generation Sequencing (NGS), by the culture dependent method this species was dominant only in only 10 samples. Based on isolates identification, LAB diversity was higher for 7 sourdoughs with the recovery of L. curvatus, L. brevis, L. heilongjiangensis, L. xiangfangensis, L. koreensis, L. pontis, Weissella sp. and Pediococcus pentosaceus, as the most representative species. L. koreensis, L. heilongjiangensis and L. xiangfangensis were identified in traditional Asian food and here for the first time as dominant in organic sourdough. This study highlighted that L. sanfranciscensis was not the major species in 6/16 sourdough samples and that a relatively high LAB diversity can be observed in French organic sourdough.

  6. Relative abundance of chemical forms of Cu(II) and Cd(II) on soybean roots as influenced by pH, cations and organic acids

    PubMed Central

    Zhou, Qin; Liu, Zhao-dong; Liu, Yuan; Jiang, Jun; Xu, Ren-kou

    2016-01-01

    Little information is available on chemical forms of heavy metals on integrate plant roots. KNO3 (1 M), 0.05M EDTA at pH6 and 0.01 M HCl were used sequentially to extract the exchangeable, complexed and precipitated forms of Cu(II) and Cd(II) from soybean roots and then to investigate chemical form distribution of Cu(II) and Cd(II) on soybean roots. Cu(II) and Cd(II) adsorbed on soybean roots were mainly exchangeable form, followed by complexed form, while their precipitated forms were very low under acidic conditions. Soybean roots had a higher adsorption affinity to Cu(II) than Cd(II), leading to higher toxic of Cu(II) than Cd(II). An increase in solution pH increased negative charge on soybean and thus increased exchangeable Cu(II) and Cd(II) on the roots. Ca2+, Mg2+ and NH4+ reduced exchangeable Cu(II) and Cd(II) levels on soybean roots and these cations showed greater effects on Cd(II) than Cu(II) due to greater adsorption affinity of the roots to Cu(II) than Cd(II). L-malic and citric acids decreased exchangeable and complexed Cu(II) on soybean roots. In conclusion, Cu(II) and Cd(II) mainly existed as exchangeable and complexed forms on soybean roots. Ca2+ and Mg2+ cations and citric and L-malic acids can potentially alleviate Cu(II) and Cd(II) toxicity to plants. PMID:27805020

  7. Relative abundance of chemical forms of Cu(II) and Cd(II) on soybean roots as influenced by pH, cations and organic acids

    NASA Astrophysics Data System (ADS)

    Zhou, Qin; Liu, Zhao-Dong; Liu, Yuan; Jiang, Jun; Xu, Ren-Kou

    2016-11-01

    Little information is available on chemical forms of heavy metals on integrate plant roots. KNO3 (1 M), 0.05M EDTA at pH6 and 0.01 M HCl were used sequentially to extract the exchangeable, complexed and precipitated forms of Cu(II) and Cd(II) from soybean roots and then to investigate chemical form distribution of Cu(II) and Cd(II) on soybean roots. Cu(II) and Cd(II) adsorbed on soybean roots were mainly exchangeable form, followed by complexed form, while their precipitated forms were very low under acidic conditions. Soybean roots had a higher adsorption affinity to Cu(II) than Cd(II), leading to higher toxic of Cu(II) than Cd(II). An increase in solution pH increased negative charge on soybean and thus increased exchangeable Cu(II) and Cd(II) on the roots. Ca2+, Mg2+ and NH4+ reduced exchangeable Cu(II) and Cd(II) levels on soybean roots and these cations showed greater effects on Cd(II) than Cu(II) due to greater adsorption affinity of the roots to Cu(II) than Cd(II). L-malic and citric acids decreased exchangeable and complexed Cu(II) on soybean roots. In conclusion, Cu(II) and Cd(II) mainly existed as exchangeable and complexed forms on soybean roots. Ca2+ and Mg2+ cations and citric and L-malic acids can potentially alleviate Cu(II) and Cd(II) toxicity to plants.

  8. Recovery of organic acids

    DOEpatents

    Verser, Dan W.; Eggeman, Timothy J.

    2009-10-13

    A method is disclosed for the recovery of an organic acid from a dilute salt solution in which the cation of the salt forms an insoluble carbonate salt. A tertiary amine and CO.sub.2 are introduced to the solution to form the insoluble carbonate salt and a complex between the acid and an amine. A water immiscible solvent, such as an alcohol, is added to extract the acid/amine complex from the dilute salt solution to a reaction phase. The reaction phase is continuously dried and a product between the acid and the solvent, such as an ester, is formed.

  9. Recovery of organic acids

    DOEpatents

    Verser, Dan W [Menlo Park, CA; Eggeman, Timothy J [Lakewood, CO

    2011-11-01

    A method is disclosed for the recovery of an organic acid from a dilute salt solution in which the cation of the salt forms an insoluble carbonate salt. A tertiary amine and CO.sub.2 are introduced to the solution to form the insoluble carbonate salt and a complex between the acid and an amine. A water immiscible solvent, such as an alcohol, is added to extract the acid/amine complex from the dilute salt solution to a reaction phase. The reaction phase is continuously dried and a product between the acid and the solvent, such as an ester, is formed.

  10. Binning of shallowly sampled metagenomic sequence fragments reveals that low abundance bacteria play important roles in sulfur cycling and degradation of complex organic polymers in an acid mine drainage community

    NASA Astrophysics Data System (ADS)

    Dick, G. J.; Andersson, A.; Banfield, J. F.

    2007-12-01

    Our understanding of environmental microbiology has been greatly enhanced by community genome sequencing of DNA recovered directly the environment. Community genomics provides insights into the diversity, community structure, metabolic function, and evolution of natural populations of uncultivated microbes, thereby revealing dynamics of how microorganisms interact with each other and their environment. Recent studies have demonstrated the potential for reconstructing near-complete genomes from natural environments while highlighting the challenges of analyzing community genomic sequence, especially from diverse environments. A major challenge of shotgun community genome sequencing is identification of DNA fragments from minor community members for which only low coverage of genomic sequence is present. We analyzed community genome sequence retrieved from biofilms in an acid mine drainage (AMD) system in the Richmond Mine at Iron Mountain, CA, with an emphasis on identification and assembly of DNA fragments from low-abundance community members. The Richmond mine hosts an extensive, relatively low diversity subterranean chemolithoautotrophic community that is sustained entirely by oxidative dissolution of pyrite. The activity of these microorganisms greatly accelerates the generation of AMD. Previous and ongoing work in our laboratory has focused on reconstrucing genomes of dominant community members, including several bacteria and archaea. We binned contigs from several samples (including one new sample and two that had been previously analyzed) by tetranucleotide frequency with clustering by Self-Organizing Maps (SOM). The binning, evaluated by comparison with information from the manually curated assembly of the dominant organisms, was found to be very effective: fragments were correctly assigned with 95% accuracy. Improperly assigned fragments often contained sequences that are either evolutionarily constrained (e.g. 16S rRNA genes) or mobile elements that are

  11. Microorganisms for producing organic acids

    DOEpatents

    Pfleger, Brian Frederick; Begemann, Matthew Brett

    2014-09-30

    Organic acid-producing microorganisms and methods of using same. The organic acid-producing microorganisms comprise modifications that reduce or ablate AcsA activity or AcsA homolog activity. The modifications increase tolerance of the microorganisms to such organic acids as 3-hydroxypropionic acid, acrylic acid, propionic acid, lactic acid, and others. Further modifications to the microorganisms increase production of such organic acids as 3-hydroxypropionic acid, lactate, and others. Methods of producing such organic acids as 3-hydroxypropionic acid, lactate, and others with the modified microorganisms are provided. Methods of using acsA or homologs thereof as counter-selectable markers are also provided.

  12. Distribution and abundance of organic thiols

    NASA Technical Reports Server (NTRS)

    Fahey, R.

    1985-01-01

    The role of glutathione (GSH) in protecting against the toxicity of oxygen and oxygen by products is well established for all eukaryotes studied except Entamoeba histolytica which lacks mitochrondria, chloroplasts, and microtubules. The GSH is not universal among prokaryotes. Entamoeba histolytica does not produce GSH or key enzymes of GSH metabolism. A general method of thiol analysis based upon fluorescent labeling with monobromobimane and HPLC separation of the resulting thiol derivatives was developed to determine the occurrence of GSH and other low molecular weight thiols in bacteria. Glutathione is the major thiol in cyanobacteria and in most bacteria closely related to the purple photosynthetic bacteria, but GSH was not found in archaebacteria, green bacteria, or GRAM positive bacteria. It suggested that glutathione metabolism was incorporated into eukaryotes at the time that mitochondria and chloroplasts were acquired by endosymbiosis. In Gram positive aerobes, coenzyme A occurs at millimolar levels and CoA disulfide reductases are identified. The CoA, rather than glutathione, may function in the oxygen detoxification processes of these organisms.

  13. Nature's starships. I. Observed abundances and relative frequencies of amino acids in meteorites

    SciTech Connect

    Cobb, Alyssa K.; Pudritz, Ralph E. E-mail: pudritz@physics.mcmaster.ca

    2014-03-10

    The class of meteorites called carbonaceous chondrites are examples of material from the solar system which have been relatively unchanged from the time of their initial formation. These meteorites have been classified according to the temperatures and physical conditions of their parent planetesimals. We collate available data on amino acid abundance in these meteorites and plot the concentrations of different amino acids for each meteorite within various meteorite subclasses. We plot average concentrations for various amino acids across meteorites separated by subclass and petrologic type. We see a predominance in the abundance and variety of amino acids in CM2 and CR2 meteorites. The range in temperature corresponding to these subclasses indicates high degrees of aqueous alteration, suggesting aqueous synthesis of amino acids. Within the CM2 and CR2 subclasses, we identify trends in relative frequencies of amino acids to investigate how common amino acids are as a function of their chemical complexity. These two trends (total abundance and relative frequencies) can be used to constrain formation parameters of amino acids within planetesimals. Our organization of the data supports an onion shell model for the temperature structure of planetesimals. The least altered meteorites (type 3) and their amino acids originated near cooler surface regions. The most active amino acid synthesis likely took place at intermediate depths (type 2). The most altered materials (type 1) originated furthest toward parent body cores. This region is likely too hot to either favor amino acid synthesis or for amino acids to be retained after synthesis.

  14. Combined Effects of Ocean Warming and Acidification on Copepod Abundance, Body Size and Fatty Acid Content.

    PubMed

    Garzke, Jessica; Hansen, Thomas; Ismar, Stefanie M H; Sommer, Ulrich

    2016-01-01

    Concerns about increasing atmospheric CO2 concentrations and global warming have initiated studies on the consequences of multiple-stressor interactions on marine organisms and ecosystems. We present a fully-crossed factorial mesocosm study and assess how warming and acidification affect the abundance, body size, and fatty acid composition of copepods as a measure of nutritional quality. The experimental set-up allowed us to determine whether the effects of warming and acidification act additively, synergistically, or antagonistically on the abundance, body size, and fatty acid content of copepods, a major group of lower level consumers in marine food webs. Copepodite (developmental stages 1-5) and nauplii abundance were antagonistically affected by warming and acidification. Higher temperature decreased copepodite and nauplii abundance, while acidification partially compensated for the temperature effect. The abundance of adult copepods was negatively affected by warming. The prosome length of copepods was significantly reduced by warming, and the interaction of warming and CO2 antagonistically affected prosome length. Fatty acid composition was also significantly affected by warming. The content of saturated fatty acids increased, and the ratios of the polyunsaturated essential fatty acids docosahexaenoic- (DHA) and arachidonic acid (ARA) to total fatty acid content increased with higher temperatures. Additionally, here was a significant additive interaction effect of both parameters on arachidonic acid. Our results indicate that in a future ocean scenario, acidification might partially counteract some observed effects of increased temperature on zooplankton, while adding to others. These may be results of a fertilizing effect on phytoplankton as a copepod food source. In summary, copepod populations will be more strongly affected by warming rather than by acidifying oceans, but ocean acidification effects can modify some temperature impacts.

  15. Combined Effects of Ocean Warming and Acidification on Copepod Abundance, Body Size and Fatty Acid Content

    PubMed Central

    Hansen, Thomas; Ismar, Stefanie M. H.; Sommer, Ulrich

    2016-01-01

    Concerns about increasing atmospheric CO2 concentrations and global warming have initiated studies on the consequences of multiple-stressor interactions on marine organisms and ecosystems. We present a fully-crossed factorial mesocosm study and assess how warming and acidification affect the abundance, body size, and fatty acid composition of copepods as a measure of nutritional quality. The experimental set-up allowed us to determine whether the effects of warming and acidification act additively, synergistically, or antagonistically on the abundance, body size, and fatty acid content of copepods, a major group of lower level consumers in marine food webs. Copepodite (developmental stages 1–5) and nauplii abundance were antagonistically affected by warming and acidification. Higher temperature decreased copepodite and nauplii abundance, while acidification partially compensated for the temperature effect. The abundance of adult copepods was negatively affected by warming. The prosome length of copepods was significantly reduced by warming, and the interaction of warming and CO2 antagonistically affected prosome length. Fatty acid composition was also significantly affected by warming. The content of saturated fatty acids increased, and the ratios of the polyunsaturated essential fatty acids docosahexaenoic- (DHA) and arachidonic acid (ARA) to total fatty acid content increased with higher temperatures. Additionally, here was a significant additive interaction effect of both parameters on arachidonic acid. Our results indicate that in a future ocean scenario, acidification might partially counteract some observed effects of increased temperature on zooplankton, while adding to others. These may be results of a fertilizing effect on phytoplankton as a copepod food source. In summary, copepod populations will be more strongly affected by warming rather than by acidifying oceans, but ocean acidification effects can modify some temperature impacts. PMID:27224476

  16. Analysis of Organic Acids.

    ERIC Educational Resources Information Center

    Griswold, John R.; Rauner, Richard A.

    1990-01-01

    Presented are the procedures and a discussion of the results for an experiment in which students select unknown carboxylic acids, determine their melting points, and investigate their solubility behavior in water and ethanol. A table of selected carboxylic acids is included. (CW)

  17. Relative Amino Acid Composition Signatures of Organisms and Environments

    PubMed Central

    Moura, Alexandra; Savageau, Michael A.; Alves, Rui

    2013-01-01

    Background Identifying organism-environment interactions at the molecular level is crucial to understanding how organisms adapt to and change the chemical and molecular landscape of their habitats. In this work we investigated whether relative amino acid compositions could be used as a molecular signature of an environment and whether such a signature could also be observed at the level of the cellular amino acid composition of the microorganisms that inhabit that environment. Methodologies/Principal Findings To address these questions we collected and analyzed environmental amino acid determinations from the literature, and estimated from complete genomic sequences the global relative amino acid abundances of organisms that are cognate to the different types of environment. Environmental relative amino acid abundances clustered into broad groups (ocean waters, host-associated environments, grass land environments, sandy soils and sediments, and forest soils), indicating the presence of amino acid signatures specific for each environment. These signatures correlate to those found in organisms. Nevertheless, relative amino acid abundance of organisms was more influenced by GC content than habitat or phylogeny. Conclusions Our results suggest that relative amino acid composition can be used as a signature of an environment. In addition, we observed that the relative amino acid composition of organisms is not highly determined by environment, reinforcing previous studies that find GC content to be the major factor correlating to amino acid composition in living organisms. PMID:24204807

  18. [Seasonality and contribution to acid rain of the carbon abundance in rainwater].

    PubMed

    Xu, Tao; Song, Zhi-guang; Liu, Jun-feng; Wang, Cui-ping

    2008-02-01

    This paper reports the results from a study of the carbon abundance in rainwater of Guangzhou city, China. The determination of TOC, DOC, POC and PEC helps to study the seasonality of carbon abundance and its contribution to the acid rain. The results display the fact that the average contents of TOC, DOC, POC and PEC are 7.10 mg/L, 3.58 mg/L, 3.60 mg/L and 0.72 mg/L, respectively. These results confirm the deep effect of the organic pollutant to the rain. The seasonality exists in the carbon abundance of rainwater. The contents of TOC and DOC are up to the maximum in spring and the minimum in summer; the contribution of POC to TOC in summer is obviously higher than that in other seasons; and the relative content of POC is clearly higher in dry season than that in wet season. The seasonality reflects the more emission of the total pollutant in spring and the solid particle pollutant in summer than those in other seasons. Moreover, the emission of the organic pollutant from the mobile vehicles is more obvious in dry season than that in wet season. The contents of TOC and DOC have the negative correlation to the pH values, which confirms the contribution effect of the organic pollutant, such as vehicle emission, to the acid rain.

  19. High abundance of Crenarchaeota in a temperate acidic forest soil.

    PubMed

    Kemnitz, Dana; Kolb, Steffen; Conrad, Ralf

    2007-06-01

    The objective of the study was to elucidate the depth distribution and community composition of Archaea in a temperate acidic forest soil. Numbers of Archaea and Bacteria were measured in the upper 18 cm of the soil, and soil cores were sampled on two separate occasions using quantitative PCR targeting 16S rRNA genes. Maximum numbers of Archaea were 0.6-3.8 x 10(8) 16S rRNA genes per gram of dry soil. Numbers of Bacteria were generally higher, but Archaea always accounted for a high percentage of the total gene numbers (12-38%). The archaeal community structure was analysed by the construction of clone libraries and by terminal restriction length polymorphism (T-RFLP) using the same Archaea-specific primers. With the reverse primer labelled, T-RFLP analysis led to the detection of four T-RFs. Three had lengths of 83, 185 and 218 bp and corresponded to uncultured Crenarchaeota. One (447 bp) was assigned to Thermoplasmales. Labelling of the forward primer allowed further separation of the T-RF into Crenarchaeota Group I.1c and Group I.1b, and indicated that Crenarchaeota of the Group I.1c were the predominant 16S rRNA genotype (abundance of Archaea and concentration of ammonia and nitrate decreased with soil depth. Hence it is unclear if the detected Crenarchaeota Group I.1c participated in ammonia oxidation or had another phenotype.

  20. Variations of the abundance and nucleic acid content of heterotrophic bacteria in Beaufort Shelf waters during winter and spring

    NASA Astrophysics Data System (ADS)

    Belzile, Claude; Brugel, Sonia; Nozais, Christian; Gratton, Yves; Demers, Serge

    2008-12-01

    Depth profiles of heterotrophic bacteria abundance were measured weekly over a 6-month period from December to May in Franklin Bay, a 230 m-deep coastal Arctic Ocean site of the southeastern Beaufort Sea. Total bacteria, low nucleic acid (LNA) and high nucleic acid (HNA) bacteria abundances were measured using flow cytometry after SYBR Green I staining. The HNA bacteria abundance in surface waters started to increase 5-6 weeks after phytoplankton growth resumed in spring, increasing from 1 × 10 5 to 3 × 10 5 cells mL - 1 over an 8-week period, with a net growth rate of 0.018 d - 1 . LNA bacteria response was delayed by more than two months relative to the beginning of the phytoplankton biomass accumulation and had a lower net growth rate of 0.013 d - 1 . The marked increase in bacterial abundance occurred before any significant increase in organic matter input from river discharge (as indicated by the unchanged surface water salinity and DOC concentrations), and in the absence of water temperature increase. The abundance of bacteria below the halocline was relatively high until January (up to 5 × 10 5 cells mL - 1 ) but then decreased to values close to 2 × 10 5 cells mL - 1 . The three-fold bacterial abundance increase observed in surface waters in spring was mostly due to HNA bacteria, supporting the idea that these cells are the most active.

  1. Anatomy of a cluster IDP. Part 2: Noble gas abundances, trace element geochemistry, isotopic abundances, and trace organic chemistry of several fragments from L2008#5

    NASA Technical Reports Server (NTRS)

    Thomas, K. L.; Clemett, S. J.; Flynn, G. J.; Keller, L. P.; Mckay, David S.; Messenger, S.; Nier, A. O.; Schlutter, D. J.; Sutton, S. R.; Walker, R. M.

    1994-01-01

    The topics discussed include the following: noble gas content and release temperatures; trace element abundances; heating summary of cluster fragments; isotopic measurements; and trace organic chemistry.

  2. Diversity, abundance, and sex-specific expression of chemosensory proteins in the reproductive organs of the locust Locusta migratoria manilensis.

    PubMed

    Zhou, Xian-Hong; Ban, Li-Ping; Iovinella, Immacolata; Zhao, Li-Jing; Gao, Qian; Felicioli, Antonio; Sagona, Simona; Pieraccini, Giuseppe; Pelosi, Paolo; Zhang, Long; Dani, Francesca Romana

    2013-01-01

    Chemosensory proteins (CSPs) are small soluble proteins often associated with chemosensory organs in insects but include members involved in other functions, such as pheromone delivery and development. Although the CSPs of the sensory organs have been extensively studied, little is known on their functions in other parts of the body. A first screening of the available databases has identified 70 sequences encoding CSPs in the oriental locust Locusta migratoria manilensis. Applying proteomic analysis, we have identified 17 of them abundantly expressed in the female reproductive organs, but only one (CSP91) in male organs. Bacterially expressed CSP91 binds fatty acids with a specificity for oleic and linoleic acid, as well as medium-length alcohols and esters. The same acids have been detected as the main gas chromatographic peaks in the dichloromethane extracts of reproductive organs of both sexes. The abundance and the number of CSPs in female reproductive organs indicates important roles for these proteins. We cannot exclude that different functions can be associated with each of the 17 CSPs, including delivery of semiochemicals, solubilization of hormones, direct control of development, or other unknown tasks.

  3. Organic acids tunably catalyze carbonic acid decomposition.

    PubMed

    Kumar, Manoj; Busch, Daryle H; Subramaniam, Bala; Thompson, Ward H

    2014-07-10

    Density functional theory calculations predict that the gas-phase decomposition of carbonic acid, a high-energy, 1,3-hydrogen atom transfer reaction, can be catalyzed by a monocarboxylic acid or a dicarboxylic acid, including carbonic acid itself. Carboxylic acids are found to be more effective catalysts than water. Among the carboxylic acids, the monocarboxylic acids outperform the dicarboxylic ones wherein the presence of an intramolecular hydrogen bond hampers the hydrogen transfer. Further, the calculations reveal a direct correlation between the catalytic activity of a monocarboxylic acid and its pKa, in contrast to prior assumptions about carboxylic-acid-catalyzed hydrogen-transfer reactions. The catalytic efficacy of a dicarboxylic acid, on the other hand, is significantly affected by the strength of an intramolecular hydrogen bond. Transition-state theory estimates indicate that effective rate constants for the acid-catalyzed decomposition are four orders-of-magnitude larger than those for the water-catalyzed reaction. These results offer new insights into the determinants of general acid catalysis with potentially broad implications.

  4. Endospore abundance and D:L-amino acid modeling of bacterial turnover in holocene marine sediment (Aarhus Bay)

    NASA Astrophysics Data System (ADS)

    Langerhuus, Alice T.; Røy, Hans; Lever, Mark A.; Morono, Yuki; Inagaki, Fumio; Jørgensen, Bo B.; Lomstein, Bente Aa.

    2012-12-01

    In order to study bacterial activity, and turnover times of bacterial necromass and biomass in marine sediment, two stations from the Aarhus Bay, Denmark were analyzed. Sediment cores were up to 11 m deep and covered a timescale from the present to ˜11,000 years ago. Sediment was analyzed for total hydrolysable amino acids (THAA), total hydrolysable amino sugars, the bacterial endospore marker dipicolinic acid (DPA), and amino acid enantiomers (L- and D-form) of aspartic acid. Turnover times of bacterial necromass and vegetative cells, as well as carbon oxidation rates were estimated by use of the D:L-amino acid racemization model. Diagenetic indicators were applied to evaluate the diagenetic state of the sedimentary organic matter. The contribution of amino acids to total organic carbon, and the ratio between the amino acids aspartic acid and glutamic acid, and their respective non protein degradation products, β-alanine and γ-amino butyric acid, all indicated increasing degradation state of the organic matter with sediment depth and age. Quantification of DPA showed that endospores were abundant, and increased with depth relative to vegetative cells. Most of the amino acids (97%) could be ascribed to microbial necromass, i.e. the remains of dead bacterial cells. Model estimates showed that the turnover times of microbial necromass were in the range of 0.5-1 × 105 years, while turnover times of vegetative cells were in the range of tens to hundreds of years. The turnover time of the TOC pool increased with depth in the sediment, indicating that the TOC pool became progressively more refractory and unavailable to microorganisms with depth and age of the organic matter.

  5. On the factors governing the abundance of oxalic acid in tropospheric aerosol particles

    NASA Astrophysics Data System (ADS)

    van Pinxteren, D.; Neusuess, C.; Brüggemann, E.; Gnauk, T.; Müller, K.; Herrmann, H.

    2010-12-01

    Oxalic acid is frequently observed as one of the most abundant single organic compounds in tropospheric particles. Its sources are commonly believed to be of secondary nature. In state-of-the-art multiphase chemistry models, different pathways exist, which can lead to oxalic acid as final product. Anthropogenic hydrocarbon emissions can be photochemically degraded to glyoxal and methyglyoxal, which - after partitioning into deliquescent particles or cloud droplets - are further oxidized via glyoxylic acid to oxalic acid [Herrmann et al., 2005]. A biogenic oxidation pathway starts with isoprene or monoterpene emissions and leads to glycolaldehyde and methylglyoxal via methacrolein and methylvinylketone, followed by aqueous phase oxalic acid formation [Lim et al., 2005]. As suggested by Warneck, 2003, a marine pathway might exist, starting from marine ethene emissions and leading via glycolaldehyde to oxalic acid. The aim of this study was to elucidate from field measurements the importance of each of these pathways. To this aim, oxalic acid concentrations from 144 size-resolved particle samples (5-stage Berner impactor) from different continental and coastal European sampling sites were statistically analyzed using principal component analysis (PCA). Hourly back trajectories were calculated for each sampling interval using the HYSPLIT model [Draxler and Rolph, 2003] and combined in a novel way with global land cover data to yield “residence times” of the sampled air masses above urban, agricultural, forested, and oceanic areas. These residence times served as quantitative proxies for different emission regimes (anthropogenic, biogenic, marine) in the statistical analysis. Additionally, meteorological parameters such as sunflux along the trajectories or mixing layer depth at the sampling site were retrieved from the HYSPLIT output. PCA of the continental dataset retrieved two factors that were connected to the oxalic acid concentrations. A first one showed high

  6. The activated sludge ecosystem contains a core community of abundant organisms.

    PubMed

    Saunders, Aaron M; Albertsen, Mads; Vollertsen, Jes; Nielsen, Per H

    2016-01-01

    Understanding the microbial ecology of a system requires that the observed population dynamics can be linked to their metabolic functions. However, functional characterization is laborious and the choice of organisms should be prioritized to those that are frequently abundant (core) or transiently abundant, which are therefore putatively make the greatest contribution to carbon turnover in the system. We analyzed the microbial communities in 13 Danish wastewater treatment plants with nutrient removal in consecutive years and a single plant periodically over 6 years, using Illumina sequencing of 16S ribosomal RNA amplicons of the V4 region. The plants contained a core community of 63 abundant genus-level operational taxonomic units (OTUs) that made up 68% of the total reads. A core community consisting of abundant OTUs was also observed within the incoming wastewater to three plants. The net growth rate for individual OTUs was quantified using mass balance, and it was found that 10% of the total reads in the activated sludge were from slow or non-growing OTUs, and that their measured abundance was primarily because of immigration with the wastewater. Transiently abundant organisms were also identified. Among them the genus Nitrotoga (class Betaproteobacteria) was the most abundant putative nitrite oxidizer in a number of activated sludge plants, which challenges previous assumptions that Nitrospira (phylum Nitrospirae) are the primary nitrite-oxidizers in activated sludge systems with nutrient removal.

  7. The activated sludge ecosystem contains a core community of abundant organisms

    PubMed Central

    Saunders, Aaron M; Albertsen, Mads; Vollertsen, Jes; Nielsen, Per H

    2016-01-01

    Understanding the microbial ecology of a system requires that the observed population dynamics can be linked to their metabolic functions. However, functional characterization is laborious and the choice of organisms should be prioritized to those that are frequently abundant (core) or transiently abundant, which are therefore putatively make the greatest contribution to carbon turnover in the system. We analyzed the microbial communities in 13 Danish wastewater treatment plants with nutrient removal in consecutive years and a single plant periodically over 6 years, using Illumina sequencing of 16S ribosomal RNA amplicons of the V4 region. The plants contained a core community of 63 abundant genus-level operational taxonomic units (OTUs) that made up 68% of the total reads. A core community consisting of abundant OTUs was also observed within the incoming wastewater to three plants. The net growth rate for individual OTUs was quantified using mass balance, and it was found that 10% of the total reads in the activated sludge were from slow or non-growing OTUs, and that their measured abundance was primarily because of immigration with the wastewater. Transiently abundant organisms were also identified. Among them the genus Nitrotoga (class Betaproteobacteria) was the most abundant putative nitrite oxidizer in a number of activated sludge plants, which challenges previous assumptions that Nitrospira (phylum Nitrospirae) are the primary nitrite-oxidizers in activated sludge systems with nutrient removal. PMID:26262816

  8. Bird diversity and abundance in organic and conventional apple orchards in northern Japan

    PubMed Central

    Katayama, Naoki

    2016-01-01

    Many studies have investigated the benefits of agri-environmental schemes, such as organic farming, on biodiversity conservation in annual systems, but their effectiveness in perennial systems is less well understood, particularly in bird communities in temperate regions of Asia. This study examined the effects of organic farming practices on species richness and abundance of breeding birds in apple orchards in northern Japan. Bird counts were conducted in six pairs of organic and conventional orchards during the breeding season in April and May 2015. The total species richness of birds, estimated by sample- and coverage-based rarefaction and extrapolation curves, was greater in organic orchards than in conventional orchards. Among the three dietary guilds (insectivore, granivore, and omnivore), only insectivorous species were more abundant in organic orchards than in conventional ones. This study offers the first quantitative evidence that organic farming can be beneficial for enhancing the diversity of birds, particularly of insectivores, in fruit orchards in Japan. PMID:27677408

  9. Organic Acid Production by Filamentous Fungi

    SciTech Connect

    Magnuson, Jon K.; Lasure, Linda L.

    2004-05-03

    Many of the commercial production processes for organic acids are excellent examples of fungal biotechnology. However, unlike penicillin, the organic acids have had a less visible impact on human well-being. Indeed, organic acid fermentations are often not even identified as fungal bioprocesses, having been overshadowed by the successful deployment of the β-lactam processes. Yet, in terms of productivity, fungal organic acid processes may be the best examples of all. For example, commercial processes using Aspergillus niger in aerated stirred-tank-reactors can convert glucose to citric acid with greater than 80% efficiency and at final concentrations in hundreds of grams per liter. Surprisingly, this phenomenal productivity has been the object of relatively few research programs. Perhaps a greater understanding of this extraordinary capacity of filamentous fungi to produce organic acids in high concentrations will allow greater exploitation of these organisms via application of new knowledge in this era of genomics-based biotechnology. In this chapter, we will explore the biochemistry and modern genetic aspects of the current and potential commercial processes for making organic acids. The organisms involved, with a few exceptions, are filamentous fungi, and this review is limited to that group. Although yeasts including Saccharomyces cerevisiae, species of Rhodotorula, Pichia, and Hansenula are important organisms in fungal biotechnology, they have not been significant for commercial organic acid production, with one exception. The yeast, Yarrowia lipolytica, and related yeast species, may be in use commercially to produce citric acid (Lopez-Garcia, 2002). Furthermore, in the near future engineered yeasts may provide new commercial processes to make lactic acid (Porro, Bianchi, Ranzi, Frontali, Vai, Winkler, & Alberghina, 2002). This chapter is divided into two parts. The first contains a review of the commercial aspects of current and potential large

  10. Consequences of organic farming and landscape heterogeneity for species richness and abundance of farmland birds.

    PubMed

    Smith, Henrik G; Dänhardt, Juliana; Lindström, Ake; Rundlöf, Maj

    2010-04-01

    It has been suggested that organic farming may benefit farmland biodiversity more in landscapes that have lost a significant part of its former landscape heterogeneity. We tested this hypothesis by comparing bird species richness and abundance during the breeding season in organic and conventional farms, matched to eliminate all differences not directly linked to the farming practice, situated in either homogeneous plains with only a little semi-natural habitat or in heterogeneous farmland landscapes with abundant field borders and semi-natural grasslands. The effect of farm management on species richness interacted with landscape structure, such that there was a positive relationship between organic farming and diversity only in homogeneous landscapes. This pattern was mainly dependent on the species richness of passerine birds, in particular those that were invertebrate feeders. Species richness of non-passerines was positively related to organic farming independent of the landscape context. Bird abundance was positively related to landscape heterogeneity but not to farm management. This was mainly because the abundance of passerines, particularly invertebrate feeders, was positively related to landscape heterogeneity. We suggest that invertebrate feeders particularly benefit from organic farming because of improved foraging conditions through increased invertebrate abundances in otherwise depauperate homogeneous landscapes. Although many seed-eaters also benefit from increased insect abundance, they may also utilize crop seed resources in homogeneous landscapes and conventional farms. The occurrence of an interactive effect of organic farming and landscape heterogeneity on bird diversity will have consequences for the optimal allocation of resources to restore the diversity of farmland birds.

  11. Reduced nitrification and abundance of ammonia-oxidizing bacteria in acidic soil amended with biochar.

    PubMed

    Wang, Zhenyu; Zong, Haiying; Zheng, Hao; Liu, Guocheng; Chen, Lei; Xing, Baoshan

    2015-11-01

    Adding biochar into soils has potential to manipulate soil nitrification process due to its impacts on nitrogen (N) cycling, however, the exact mechanisms underlying the alteration of nitrification process in soils are still not clear. Nitrification in an acidic orchard soil amended with peanut shell biochar (PBC) produced at 400 °C was investigated. Nitrification was weakened by PBC addition due to the decreased NH4(+)-N content and reduced ammonia-oxidizing bacteria (AOB) abundance in PBC-amended soils. Adding phenolic compounds (PHCs) free biochar (PBC-P) increased the AOB abundance and the DGGE band number, indicating that PHCs remaining in the PBC likely reduced AOB abundance and diversity. However, PBC addition stimulated rape growth and increased N bioavailability. Overall, adding PBC could suppress the nitrification process and improve N bioavailability in the agricultural soils, and thus possibly mitigate the environmental negative impacts and improving N use efficiency in the acidic soils added with N fertilizer.

  12. Organic Acid Production by Basidiomycetes

    PubMed Central

    Takao, Shoichi

    1965-01-01

    Sixty-seven strains belonging to 47 species of Basidiomycetes were examined for their acid-producing abilities in glucose media, in both the presence and absence of CaCO3, in stationary and shake cultures. Some strains were found to produce large quantities of oxalic acid. The oxalic acid-producing strains could be separated into two groups. Strains of one group (mostly brown-rot fungi) were able to produce oxalic acid, regardless of whether CaCO3 was present in the medium. Strains of the other group (mostly white-rot fungi) were characterized by their ability to produce oxalic acid only when CaCO3 was added to the medium. With the latter group, shake-culturing was generally more effective than stationary culturing in respect to acid production. In the CaCO3-containing media, Schizophyllum commune, Merulius tremellosus, and Porodisculus pendulus were found to produce substantial amounts of L-malic acid as a main metabolic product, along with small quantities of oxalic and other acids in shake cultures. Especially, S. commune and M. tremellosus may be employed as malic acid-producing species. PMID:5867653

  13. Chemoselective single-site Earth-abundant metal catalysts at metal-organic framework nodes

    NASA Astrophysics Data System (ADS)

    Manna, Kuntal; Ji, Pengfei; Lin, Zekai; Greene, Francis X.; Urban, Ania; Thacker, Nathan C.; Lin, Wenbin

    2016-08-01

    Earth-abundant metal catalysts are critically needed for sustainable chemical synthesis. Here we report a simple, cheap and effective strategy of producing novel earth-abundant metal catalysts at metal-organic framework (MOF) nodes for broad-scope organic transformations. The straightforward metalation of MOF secondary building units (SBUs) with cobalt and iron salts affords highly active and reusable single-site solid catalysts for a range of organic reactions, including chemoselective borylation, silylation and amination of benzylic C-H bonds, as well as hydrogenation and hydroboration of alkenes and ketones. Our structural, spectroscopic and kinetic studies suggest that chemoselective organic transformations occur on site-isolated, electron-deficient and coordinatively unsaturated metal centres at the SBUs via σ-bond metathesis pathways and as a result of the steric environment around the catalytic site. MOFs thus provide a novel platform for the development of highly active and affordable base metal catalysts for the sustainable synthesis of fine chemicals.

  14. Chemoselective single-site Earth-abundant metal catalysts at metal-organic framework nodes.

    PubMed

    Manna, Kuntal; Ji, Pengfei; Lin, Zekai; Greene, Francis X; Urban, Ania; Thacker, Nathan C; Lin, Wenbin

    2016-08-30

    Earth-abundant metal catalysts are critically needed for sustainable chemical synthesis. Here we report a simple, cheap and effective strategy of producing novel earth-abundant metal catalysts at metal-organic framework (MOF) nodes for broad-scope organic transformations. The straightforward metalation of MOF secondary building units (SBUs) with cobalt and iron salts affords highly active and reusable single-site solid catalysts for a range of organic reactions, including chemoselective borylation, silylation and amination of benzylic C-H bonds, as well as hydrogenation and hydroboration of alkenes and ketones. Our structural, spectroscopic and kinetic studies suggest that chemoselective organic transformations occur on site-isolated, electron-deficient and coordinatively unsaturated metal centres at the SBUs via σ-bond metathesis pathways and as a result of the steric environment around the catalytic site. MOFs thus provide a novel platform for the development of highly active and affordable base metal catalysts for the sustainable synthesis of fine chemicals.

  15. Chemoselective single-site Earth-abundant metal catalysts at metal–organic framework nodes

    SciTech Connect

    Manna, Kuntal; Ji, Pengfei; Lin, Zekai; Greene, Francis X.; Urban, Ania; Thacker, Nathan C.; Lin, Wenbin

    2016-08-30

    Earth-abundant metal catalysts are critically needed for sustainable chemical synthesis. Here we report a simple, cheap and effective strategy of producing novel earth-abundant metal catalysts at metal–organic framework (MOF) nodes for broad-scope organic transformations. The straightforward metalation of MOF secondary building units (SBUs) with cobalt and iron salts affords highly active and reusable single-site solid catalysts for a range of organic reactions, including chemoselective borylation, silylation and amination of benzylic C–H bonds, as well as hydrogenation and hydroboration of alkenes and ketones. Our structural, spectroscopic and kinetic studies suggest that chemoselective organic transformations occur on site-isolated, electron-deficient and coordinatively unsaturated metal centres at the SBUs via σ-bond metathesis pathways and as a result of the steric environment around the catalytic site. MOFs thus provide a novel platform for the development of highly active and affordable base metal catalysts for the sustainable synthesis of fine chemicals.

  16. SEASONAL ABUNDANCE OF ORGANIC MOLECULAR MARKERS IN URBAN PARTICULATE MATTER FROM PHILADELPHIA, PA

    EPA Science Inventory

    Organic molecular markers were measured in airborne particulate matter (PM10) from the City of Philadelphia North Broad Street air quality monitoring site to identify the seasonal abundances of key tracer compounds together with their dominant sources. Daily PM10...

  17. Metabolic potential of fatty acid oxidation and anaerobic respiration by abundant members of Thaumarchaeota and Thermoplasmata in deep anoxic peat

    DOE PAGES

    Lin, Xueju; Handley, Kim M.; Gilbert, Jack A.; ...

    2015-12-01

    To probe the metabolic potential of abundant Archaea in boreal peats, we reconstructed two near-complete archaeal genomes, affiliated with Thaumarchaeota group 1.1c (bin Fn1, 8% abundance), which was a genomically unrepresented group, and Thermoplasmata (bin Bg1, 26% abundance), from metagenomic data acquired from deep anoxic peat layers. Each of the near-complete genomes encodes the potential to degrade long-chain fatty acids (LCFA) via β-oxidation. Fn1 has the potential to oxidize LCFA either by syntrophic interaction with methanogens or by coupling oxidation with anaerobic respiration using fumarate as a terminal electron acceptor (TEA). Fn1 is the first Thaumarchaeota genome without an identifiablemore » carbon fixation pathway, indicating that this mesophilic phylum encompasses more diverse metabolisms than previously thought. Furthermore, we report genetic evidence suggestive of sulfite and/or organosulfonate reduction by Thermoplasmata Bg1. In deep peat, inorganic TEAs are often depleted to extremely low levels, yet the anaerobic respiration predicted for two abundant archaeal members suggests organic electron acceptors such as fumarate and organosulfonate (enriched in humic substances) may be important for respiration and C mineralization in peatlands.« less

  18. Metabolic potential of fatty acid oxidation and anaerobic respiration by abundant members of Thaumarchaeota and Thermoplasmata in deep anoxic peat

    SciTech Connect

    Lin, Xueju; Handley, Kim M.; Gilbert, Jack A.; Kostka, Joel E.

    2015-12-01

    To probe the metabolic potential of abundant Archaea in boreal peats, we reconstructed two near-complete archaeal genomes, affiliated with Thaumarchaeota group 1.1c (bin Fn1, 8% abundance), which was a genomically unrepresented group, and Thermoplasmata (bin Bg1, 26% abundance), from metagenomic data acquired from deep anoxic peat layers. Each of the near-complete genomes encodes the potential to degrade long-chain fatty acids (LCFA) via β-oxidation. Fn1 has the potential to oxidize LCFA either by syntrophic interaction with methanogens or by coupling oxidation with anaerobic respiration using fumarate as a terminal electron acceptor (TEA). Fn1 is the first Thaumarchaeota genome without an identifiable carbon fixation pathway, indicating that this mesophilic phylum encompasses more diverse metabolisms than previously thought. Furthermore, we report genetic evidence suggestive of sulfite and/or organosulfonate reduction by Thermoplasmata Bg1. In deep peat, inorganic TEAs are often depleted to extremely low levels, yet the anaerobic respiration predicted for two abundant archaeal members suggests organic electron acceptors such as fumarate and organosulfonate (enriched in humic substances) may be important for respiration and C mineralization in peatlands.

  19. Metabolic potential of fatty acid oxidation and anaerobic respiration by abundant members of Thaumarchaeota and Thermoplasmata in deep anoxic peat.

    PubMed

    Lin, Xueju; Handley, Kim M; Gilbert, Jack A; Kostka, Joel E

    2015-12-01

    To probe the metabolic potential of abundant Archaea in boreal peats, we reconstructed two near-complete archaeal genomes, affiliated with Thaumarchaeota group 1.1c (bin Fn1, 8% abundance), which was a genomically unrepresented group, and Thermoplasmata (bin Bg1, 26% abundance), from metagenomic data acquired from deep anoxic peat layers. Each of the near-complete genomes encodes the potential to degrade long-chain fatty acids (LCFA) via β-oxidation. Fn1 has the potential to oxidize LCFA either by syntrophic interaction with methanogens or by coupling oxidation with anaerobic respiration using fumarate as a terminal electron acceptor (TEA). Fn1 is the first Thaumarchaeota genome without an identifiable carbon fixation pathway, indicating that this mesophilic phylum encompasses more diverse metabolisms than previously thought. Furthermore, we report genetic evidence suggestive of sulfite and/or organosulfonate reduction by Thermoplasmata Bg1. In deep peat, inorganic TEAs are often depleted to extremely low levels, yet the anaerobic respiration predicted for two abundant archaeal members suggests organic electron acceptors such as fumarate and organosulfonate (enriched in humic substances) may be important for respiration and C mineralization in peatlands.

  20. Organic acids in naturally colored surface waters

    USGS Publications Warehouse

    Lamar, William L.; Goerlitz, D.F.

    1966-01-01

    Most of the organic matter in naturally colored surface waters consists of a mixture of carboxylic acids or salts of these acids. Many of the acids color the water yellow to brown; however, not all of the acids are colored. These acids range from simple to complex, but predominantly they are nonvolatile polymeric carboxylic acids. The organic acids were recovered from the water by two techniques: continuous liquid-liquid extraction with n-butanol and vacuum evaporation at 50?C (centigrade). The isolated acids were studied by techniques of gas, paper, and column chromatography and infrared spectroscopy. About 10 percent of the acids recovered were volatile or could be made volatile for gas chromatographic analysis. Approximately 30 of these carboxylic acids were isolated, and 13 of them were individually identified. The predominant part of the total acids could not be made volatile for gas chromatographic analysis. Infrared examination of many column chromatographic fractions indicated that these nonvolatile substances are primarily polymeric hydroxy carboxylic acids having aromatic and olefinic unsaturation. The evidence suggests that some of these acids result from polymerization in aqueous solution. Elemental analysis of the sodium fusion products disclosed the absence of nitrogen, sulfur, and halogens.

  1. Correlation of Sulfuric Acid Hydrate Abundance with Charged Particle Flux at the Surface of Europa

    NASA Astrophysics Data System (ADS)

    Dalton, James B.; Paranicas, C. P.; Cassidy, T. A.; Shirley, J. H.

    2010-10-01

    The trailing hemisphere of Jupiter's moon Europa is bombarded by charged particles trapped within Jupiter's magnetosphere. Sulfur ion implantation and impacting energetic electrons strongly affect the surface chemistry of Europa. Understanding these processes is important for disentangling the extrinsic and intrinsic components of Europa's surface chemistry. In the sulfur cycle model of Carlson et al. (Science 286, 97, 1999), hydrated sulfuric acid represents the dominant reaction product of radiolytic surface modification processes on Europa. In recent compositional investigations employing linear mixture modeling, Dalton et al. (LPSC XV, #2511, 2009) and Shirley et al. (Icarus, in press, 2010) document a well-defined gradient of hydrated sulfuric acid abundance for a study area spanning the leading side - trailing side boundary in Argadnel Regio. Sulfuric acid hydrate abundance in this region increases toward the trailing side apex. Here we compare the derived sulfuric acid hydrate abundances at 41 locations on Europa's surface with independent model results describing 1) the sulfur ion flux (Hendrix et al., 2010, in preparation), and 2) the energetic electron flux, at the same locations. We improve upon the prior calculation of electron energy into the surface of Paranicas et al. (2009, in Europa, U. Arizona, p529; Pappalardo, McKinnon, & Khurana eds.) by incorporating a realistic pitch angle dependence of the distribution. While the sulfur ion implantation and electron energy deposition model distributions differ in important details, both show trailing side gradients similar to that found for the sulfuric acid hydrate. Correlation coefficients exceed 0.9 in comparisons of each of these models with the sulfuric acid hydrate distribution. Our results support models in which the electron energy flux drives reactions that utilize implanted sulfur to produce sulfuric acid hydrate. This work was performed at the California Institute of Technology-Jet Propulsion

  2. Organic acid-tolerant microorganisms and uses thereof for producing organic acids

    DOEpatents

    Pfleger, Brian Frederick; Begemann, Matthew Brett

    2014-05-06

    Organic acid-tolerant microorganisms and methods of using same. The organic acid-tolerant microorganisms comprise modifications that reduce or ablate AcsA activity or AcsA homolog activity. The modifications increase tolerance of the microorganisms to such organic acids as 3-hydroxypropionic acid (3HP), acrylic acid, and propionic acid. Further modifications to the microorganisms such as increasing expression of malonyl-CoA reductase and/or acetyl-CoA carboxylase provide or increase the ability of the microorganisms to produce 3HP. Methods of generating an organic acid with the modified microorganisms are provided. Methods of using acsA or homologs thereof as counter-selectable markers include replacing acsA or homologs thereof in cells with genes of interest and selecting for the cells comprising the genes of interest with amounts of organic acids effective to inhibit growth of cells harboring acsA or the homologs.

  3. High abundances of water-soluble dicarboxylic acids, ketocarboxylic acids and α-dicarbonyls in the mountaintop aerosols over the North China Plain during wheat burning season

    NASA Astrophysics Data System (ADS)

    Kawamura, K.; Tachibana, E.; Okuzawa, K.; Aggarwal, S. G.; Kanaya, Y.; Wang, Z. F.

    2013-08-01

    Aerosol (TSP) samples were collected at the summit of Mount Tai (elevation: 1534 m a.s.l., 36.25° N, 117.10° E) located in the North China Plain using a high-volume air sampler and pre-combusted quartz filters. Sampling was conducted on day/night or 3 h basis in the period from 29 May to 28 June 2006 during the field burning of wheat straw residue and the post-burning season. The filter samples were analyzed for low-molecular-weight dicarboxylic acids, ketoacids and α-dicarbonyls using capillary gas chromatography (GC) and GC-MS employing water extraction and butyl ester derivatization. Molecular distributions of dicarboxylic acids (C2-C11, 220-6070 ng m-3) were characterized by a predominance of oxalic (C2) acid (105-3920 ng m-3) followed by succinic (C4) or malonic (C3) acid. Unsaturated aliphatic diacids, including maleic (M), isomaleic (iM) and fumaric (F) acids, were also detected together with aromatic diacids (phthalic, isophthalic and terephthalic acids). ω-oxocarboxylic acids (C2-C9, 24-610 ng m-3) were detected as the second most abundant compound class with the predominance of glyoxylic acid (11-360 ng m-3), followed by α-ketoacid (pyruvic acid, 3-140 ng m-3) and α-dicarbonyls (glyoxal, 1-230 ng m-3 and methylglyoxal, 2-120 ng m-3). We found that these levels (>6000 ng m-3 for diacids) are several times higher than those reported in Chinese megacities at ground levels. The concentrations of diacids increased from late May to early June, showing a maximum on 7 June, and then significantly decreased during the period 8-11 June, when the wind direction shifted from southerly to northerly. Similar temporal trends were found for ketocarboxylic acids and α-dicarbonyls as well as total carbon (TC) and water-soluble organic carbon (WSOC). The temporal variations of water-soluble organics were interpreted by the direct emission from the field burning of agricultural wastes (wheat straw) in the North China Plain and the subsequent photochemical oxidation of

  4. Links between Ammonia Oxidizer Community Structure, Abundance, and Nitrification Potential in Acidic Soils ▿ †

    PubMed Central

    Yao, Huaiying; Gao, Yangmei; Nicol, Graeme W.; Campbell, Colin D.; Prosser, James I.; Zhang, Limei; Han, Wenyan; Singh, Brajesh K.

    2011-01-01

    Ammonia oxidation is the first and rate-limiting step of nitrification and is performed by both ammonia-oxidizing archaea (AOA) and bacteria (AOB). However, the environmental drivers controlling the abundance, composition, and activity of AOA and AOB communities are not well characterized, and the relative importance of these two groups in soil nitrification is still debated. Chinese tea orchard soils provide an excellent system for investigating the long-term effects of low pH and nitrogen fertilization strategies. AOA and AOB abundance and community composition were therefore investigated in tea soils and adjacent pine forest soils, using quantitative PCR (qPCR), terminal restriction fragment length polymorphism (T-RFLP) and sequence analysis of respective ammonia monooxygenase (amoA) genes. There was strong evidence that soil pH was an important factor controlling AOB but not AOA abundance, and the ratio of AOA to AOB amoA gene abundance increased with decreasing soil pH in the tea orchard soils. In contrast, T-RFLP analysis suggested that soil pH was a key explanatory variable for both AOA and AOB community structure, but a significant relationship between community abundance and nitrification potential was observed only for AOA. High potential nitrification rates indicated that nitrification was mainly driven by AOA in these acidic soils. Dominant AOA amoA sequences in the highly acidic tea soils were all placed within a specific clade, and one AOA genotype appears to be well adapted to growth in highly acidic soils. Specific AOA and AOB populations dominated in soils at particular pH values and N content, suggesting adaptation to specific niches. PMID:21571885

  5. Production of organic acids from kitchen wastes.

    PubMed

    Loh, C W; Fakhru'l-Razi, A; Hassan, M A; Karim, M I

    1999-01-01

    This study involves the production of short-chain organic acids from kitchen wastes as intermediates for the production of biodegradable plastics. Flasks, without mixing were used for the anaerobic conversion of the organic fraction of kitchen wastes into short-chain organic acids. The influence of pH, temperature and addition of sludge cake on the rate of organic acids production and yield were evaluated. Fermentations were carried out in an incubator at different temperatures controlled at 30 degrees C. 40 degrees C, 50 degrees C, 60 degrees C and uncontrolled at room temperature. The pH was also varied at pH 5, 6, 7, and uncontrolled pH. 1.0 M phosphate buffer was used for pH control, and 1.0 M HCl and 1.0 M NaOH were added when necessary. Sludge cake addition enhanced the rate of maximum acids production from 4 days to 1 day. The organic acids produced were maximum at pH 7 and 50 degrees C i.e., 39.84 g/l on the fourth day of fermentation with a yield of 0.87 g/g soluble COD consumed, and 0.84 g/g TVS. The main organic acid produced was lactic acid (65-85%), with small amounts of acetic (10-30%), propionic (5-10%), and butyric (5-20%) acids. The results of this study showed that kitchen wastes could be fermented to high concentration of organic acids, which could be used as substrates for the production of biodegradable plastics.

  6. Organic matter degradation drives benthic cyanobacterial mat abundance on Caribbean coral reefs.

    PubMed

    Brocke, Hannah J; Polerecky, Lubos; de Beer, Dirk; Weber, Miriam; Claudet, Joachim; Nugues, Maggy M

    2015-01-01

    Benthic cyanobacterial mats (BCMs) are impacting coral reefs worldwide. However, the factors and mechanisms driving their proliferation are unclear. We conducted a multi-year survey around the Caribbean island of Curaçao, which revealed highest BCM abundance on sheltered reefs close to urbanised areas. Reefs with high BCM abundance were also characterised by high benthic cover of macroalgae and low cover of corals. Nutrient concentrations in the water-column were consistently low, but markedly increased just above substrata (both sandy and hard) covered with BCMs. This was true for sites with both high and low BCM coverage, suggesting that BCM growth is stimulated by a localised, substrate-linked release of nutrients from the microbial degradation of organic matter. This hypothesis was supported by a higher organic content in sediments on reefs with high BCM coverage, and by an in situ experiment which showed that BCMs grew within days on sediments enriched with organic matter (Spirulina). We propose that nutrient runoff from urbanised areas stimulates phototrophic blooms and enhances organic matter concentrations on the reef. This organic matter is transported by currents and settles on the seabed at sites with low hydrodynamics. Subsequently, nutrients released from the organic matter degradation fuel the growth of BCMs. Improved management of nutrients generated on land should lower organic loading of sediments and other benthos (e.g. turf and macroalgae) to reduce BCM proliferation on coral reefs.

  7. Organic Matter Degradation Drives Benthic Cyanobacterial Mat Abundance on Caribbean Coral Reefs

    PubMed Central

    Brocke, Hannah J.; Polerecky, Lubos; de Beer, Dirk; Weber, Miriam; Claudet, Joachim; Nugues, Maggy M.

    2015-01-01

    Benthic cyanobacterial mats (BCMs) are impacting coral reefs worldwide. However, the factors and mechanisms driving their proliferation are unclear. We conducted a multi-year survey around the Caribbean island of Curaçao, which revealed highest BCM abundance on sheltered reefs close to urbanised areas. Reefs with high BCM abundance were also characterised by high benthic cover of macroalgae and low cover of corals. Nutrient concentrations in the water-column were consistently low, but markedly increased just above substrata (both sandy and hard) covered with BCMs. This was true for sites with both high and low BCM coverage, suggesting that BCM growth is stimulated by a localised, substrate-linked release of nutrients from the microbial degradation of organic matter. This hypothesis was supported by a higher organic content in sediments on reefs with high BCM coverage, and by an in situ experiment which showed that BCMs grew within days on sediments enriched with organic matter (Spirulina). We propose that nutrient runoff from urbanised areas stimulates phototrophic blooms and enhances organic matter concentrations on the reef. This organic matter is transported by currents and settles on the seabed at sites with low hydrodynamics. Subsequently, nutrients released from the organic matter degradation fuel the growth of BCMs. Improved management of nutrients generated on land should lower organic loading of sediments and other benthos (e.g. turf and macroalgae) to reduce BCM proliferation on coral reefs. PMID:25941812

  8. Nanoparticles modified with multiple organic acids

    NASA Technical Reports Server (NTRS)

    Cook, Ronald Lee (Inventor); Luebben, Silvia DeVito (Inventor); Myers, Andrew William (Inventor); Smith, Bryan Matthew (Inventor); Elliott, Brian John (Inventor); Kreutzer, Cory (Inventor); Wilson, Carolina (Inventor); Meiser, Manfred (Inventor)

    2007-01-01

    Surface-modified nanoparticles of boehmite, and methods for preparing the same. Aluminum oxyhydroxide nanoparticles are surface modified by reaction with selected amounts of organic acids. In particular, the nanoparticle surface is modified by reactions with two or more different carboxylic acids, at least one of which is an organic carboxylic acid. The product is a surface modified boehmite nanoparticle that has an inorganic aluminum oxyhydroxide core, or part aluminum oxyhydroxide core and a surface-bonded organic shell. Organic carboxylic acids of this invention contain at least one carboxylic acid group and one carbon-hydrogen bond. One embodiment of this invention provides boehmite nanoparticles that have been surface modified with two or more acids one of which additional carries at least one reactive functional group. Another embodiment of this invention provides boehmite nanoparticles that have been surface modified with multiple acids one of which has molecular weight or average molecular weight greater than or equal to 500 Daltons. Yet, another embodiment of this invention provides boehmite nanoparticles that are surface modified with two or more acids one of which is hydrophobic in nature and has solubility in water of less than 15 by weight. The products of the methods of this invention have specific useful properties when used in mixture with liquids, as filler in solids, or as stand-alone entities.

  9. Nanoparticles modified with multiple organic acids

    DOEpatents

    Cook, Ronald Lee; Luebben, Silvia DeVito; Myers, Andrew William; Smith, Bryan Matthew; Elliott, Brian John; Kreutzer, Cory; Wilson, Carolina; Meiser, Manfred

    2007-07-17

    Surface-modified nanoparticles of boehmite, and methods for preparing the same. Aluminum oxyhydroxide nanoparticles are surface modified by reaction with selected amounts of organic acids. In particular, the nanoparticle surface is modified by reactions with two or more different carboxylic acids, at least one of which is an organic carboxylic acid. The product is a surface modified boehmite nanoparticle that has an inorganic aluminum oxyhydroxide core, or part aluminum oxyhydroxide core and a surface-bonded organic shell. Organic carboxylic acids of this invention contain at least one carboxylic acid group and one carbon-hydrogen bond. One embodiment of this invention provides boehmite nanoparticles that have been surface modified with two or more acids one of which additional carries at least one reactive functional group. Another embodiment of this invention provides boehmite nanoparticles that have been surface modified with multiple acids one of which has molecular weight or average molecular weight greater than or equal to 500 Daltons. Yet, another embodiment of this invention provides boehmite nanoparticles that are surface modified with two or more acids one of which is hydrophobic in nature and has solubility in water of less than 15 by weight. The products of the methods of this invention have specific useful properties when used in mixture with liquids, as filler in solids, or as stand-alone entities.

  10. Organic amendments enhance microbial diversity and abundance of functional genes in Australian Soils

    NASA Astrophysics Data System (ADS)

    Aldorri, Sind; McMillan, Mary; Pereg, Lily

    2016-04-01

    Food and cash crops play important roles in Australia's economy with black, grey and red clay soil, widely use for growing cotton, wheat, corn and other crops in rotation. While the majority of cotton growers use nitrogen and phosphate fertilizers only in the form of agrochemicals, a few experiment with the addition of manure or composted plant material before planting. We hypothesized that the use of such organic amendments would enhance the soil microbial function through increased microbial diversity and abundance, thus contribute to improved soil sustainability. To test the hypothesis we collected soil samples from two cotton-growing farms in close geographical proximity and with mostly similar production practices other than one grower has been using composted plants as organic amendment and the second farmer uses only agrochemicals. We applied the Biolog Ecoplate system to study the metabolic signature of microbial communities and used qPCR to estimate the abundance of functional genes in the soil. The soil treated with organic amendments clearly showed higher metabolic activity of a more diverse range of carbon sources as well as higher abundance of genes involved in the nitrogen and phosphorous cycles. Since microbes undertake a large number of soil functions, the use of organic amendments can contribute to the sustainability of agricultural soils.

  11. Biosynthesis of gallic acid in Rhus typhina: discrimination between alternative pathways from natural oxygen isotope abundance.

    PubMed

    Werner, Roland A; Rossmann, Andreas; Schwarz, Christine; Bacher, Adelbert; Schmidt, Hanns-Ludwig; Eisenreich, Wolfgang

    2004-10-01

    The biosynthetic pathway of gallic acid in leaves of Rhus typhina is studied by oxygen isotope ratio mass spectrometry at natural oxygen isotope abundance. The observed delta18O-values of gallic acid indicate an 18O-enrichment of the phenolic oxygen atoms of more than 30 per thousand above that of the leaf water. This enrichment implies biogenetical equivalence with oxygen atoms of carbohydrates but not with oxygen atoms introduced by monooxygenase activation of molecular oxygen. It can be concluded that all phenolic oxygen atoms of gallic acid are retained from the carbohydrate-derived precursor 5-dehydroshikimate. This supports that gallic acid is synthesized entirely or predominantly by dehydrogenation of 5-dehydroshikimate.

  12. Analysis of Carbohydrate and Fatty Acid Marker Abundance in Ricin Toxin Preparations for Forensic Information

    SciTech Connect

    Colburn, Heather A.; Wunschel, David S.; Kreuzer-Martin, Helen W.; Moran, James J.; Antolick, Kathryn C.; Melville, Angela M.

    2010-07-15

    One challenge in the forensic analysis of ricin samples is determining the method and extent of sample preparation. Ricin purification from the source castor seeds is essentially a protein purification through removal of the non-protein fractions of the seed. Two major, non-protein constituents in the seed are the castor oil and carbohydrates. Ricinoleic acid is a relatively unique fatty acid in nature and is the most abundant component of castor oil, which comprises roughly half the seed weight. The carbohydrate component comprises roughly half of the remaining “mash” left after oil and hull removal. We used derivatization of carbohydrate and fatty acid markers followed by identification and quantification using gas chromatography/mass spectrometry (GC/MS) to assess compositional changes in ricin samples purified by different methods. The loss of ricinoleic acid indicated steps for oil removal had occurred. Changes to the carbohydrate content of the sample were also observed following protein precipitation. The differential loss of arabinose relative to mannose indicated removal of the major carbohydrate fraction of the seed and enrichment of the protein content. Taken together, these changes in fatty acid and carbohydrate abundance are indicative of the preparation method used for each sample.

  13. The Roles of Organic Acids in C4 Photosynthesis.

    PubMed

    Ludwig, Martha

    2016-01-01

    Organic acids are involved in numerous metabolic pathways in all plants. The finding that some plants, known as C4 plants, have four-carbon dicarboxylic acids as the first product of carbon fixation showed these organic acids play essential roles as photosynthetic intermediates. Oxaloacetate (OAA), malate, and aspartate (Asp) are substrates for the C4 acid cycle that underpins the CO2 concentrating mechanism of C4 photosynthesis. In this cycle, OAA is the immediate, short-lived, product of the initial CO2 fixation step in C4 leaf mesophyll cells. The malate and Asp, resulting from the rapid conversion of OAA, are the organic acids delivered to the sites of carbon reduction in the bundle-sheath cells of the leaf, where they are decarboxylated, with the released CO2 used to make carbohydrates. The three-carbon organic acids resulting from the decarboxylation reactions are returned to the mesophyll cells where they are used to regenerate the CO2 acceptor pool. NADP-malic enzyme-type, NAD-malic enzyme-type, and phosphoenolpyruvate carboxykinase-type C4 plants were identified, based on the most abundant decarboxylating enzyme in the leaf tissue. The genes encoding these C4 pathway-associated decarboxylases were co-opted from ancestral C3 plant genes during the evolution of C4 photosynthesis. Malate was recognized as the major organic acid transferred in NADP-malic enzyme-type C4 species, while Asp fills this role in NAD-malic enzyme-type and phosphoenolpyruvate carboxykinase-type plants. However, accumulating evidence indicates that many C4 plants use a combination of organic acids and decarboxylases during CO2 fixation, and the C4-type categories are not rigid. The ability to transfer multiple organic acid species and utilize different decarboxylases has been suggested to give C4 plants advantages in changing and stressful environments, as well as during development, by facilitating the balance of energy between the two cell types involved in the C4 pathway of CO2

  14. The Roles of Organic Acids in C4 Photosynthesis

    PubMed Central

    Ludwig, Martha

    2016-01-01

    Organic acids are involved in numerous metabolic pathways in all plants. The finding that some plants, known as C4 plants, have four-carbon dicarboxylic acids as the first product of carbon fixation showed these organic acids play essential roles as photosynthetic intermediates. Oxaloacetate (OAA), malate, and aspartate (Asp) are substrates for the C4 acid cycle that underpins the CO2 concentrating mechanism of C4 photosynthesis. In this cycle, OAA is the immediate, short-lived, product of the initial CO2 fixation step in C4 leaf mesophyll cells. The malate and Asp, resulting from the rapid conversion of OAA, are the organic acids delivered to the sites of carbon reduction in the bundle-sheath cells of the leaf, where they are decarboxylated, with the released CO2 used to make carbohydrates. The three-carbon organic acids resulting from the decarboxylation reactions are returned to the mesophyll cells where they are used to regenerate the CO2 acceptor pool. NADP-malic enzyme-type, NAD-malic enzyme-type, and phosphoenolpyruvate carboxykinase-type C4 plants were identified, based on the most abundant decarboxylating enzyme in the leaf tissue. The genes encoding these C4 pathway-associated decarboxylases were co-opted from ancestral C3 plant genes during the evolution of C4 photosynthesis. Malate was recognized as the major organic acid transferred in NADP-malic enzyme-type C4 species, while Asp fills this role in NAD-malic enzyme-type and phosphoenolpyruvate carboxykinase-type plants. However, accumulating evidence indicates that many C4 plants use a combination of organic acids and decarboxylases during CO2 fixation, and the C4-type categories are not rigid. The ability to transfer multiple organic acid species and utilize different decarboxylases has been suggested to give C4 plants advantages in changing and stressful environments, as well as during development, by facilitating the balance of energy between the two cell types involved in the C4 pathway of CO2

  15. Hydrothermal Mineral-Assisted Organic Transformations of Carboxylic Acids

    NASA Astrophysics Data System (ADS)

    Johnson, K. N.; Gould, I.; Williams, L. B.; Hartnett, H. E.; Shock, E.

    2014-12-01

    The purpose of our research is to probe the varieties of reactions possible in a hydrothermal system in which both organic compounds and minerals interact. We performed experiments at physical conditions representative of deep-sea and subsurface systems (300°C and 1000 bar) and analyzed the effect of the mineral magnetite (Fe3O4) in systems with carboxylic acids, either phenylacetic acid or hydrocinnamic acid (a.k.a., phenylpropanoic acid). Control experiments were also conducted with the same organic compounds in the absence of magnetite. Whereas previous studies of carboxylic acid reactivity with minerals have focused exclusively on simple molecules such as acetic acid and valeric acid (Bell et al. 1994; McCollom et al. 2003), the carboxylic acids used in our study differ from previous experimental compounds by the addition of a phenyl ring, which allows for the investigation of the specific mechanistic pathways of product formation. Decarboxylation (i.e., RCO2H → RH + CO2) is one of the major reaction pathways for carboxylic acids in hydrothermal conditions without minerals. Under our experimental conditions, decarboxylation leads to the ~80% conversion of phenylacetic acid into toluene within ~50 hours and the ~8% conversion of hydrocinnamic acid to ethyl benzene within ~190 hours. We found that magnetite had a different effect on the two organic compounds studied. In experiments with phenylacetic acid, the presence of magnetite did not enhance the rate of toluene production from decarboxylation but did activate additional product pathways that include diphenyl alkanes, alkenes, and ketones, as well as benzoic acid, a carboxylic acid one carbon length shorter than the parent compound. Magnetite had even more noticeable effects on the hydrocinnamic acid system leading to an increase of its consumption at 190 hours from ~9% in magnetite's absence to ~35% in the mineral's presence. Products of the experiments with magnetite included an enhanced rate of

  16. Influence of pasture-based feeding systems on fatty acids, organic acids and volatile organic flavour compounds in yoghurt.

    PubMed

    Akbaridoust, Ghazal; Plozza, Tim; Trenerry, V Craige; Wales, William J; Auldist, Martin J; Ajlouni, Said

    2015-08-01

    The influence of different pasture-based feeding systems on fatty acids, organic acids and volatile organic flavour compounds in yoghurt was studied. Pasture is the main source of nutrients for dairy cows in many parts of the world, including southeast Australia. Milk and milk products produced in these systems are known to contain a number of compounds with positive effects on human health. In the current study, 260 cows were fed supplementary grain and forage according to one of 3 different systems; Control (a traditional pasture based diet offered to the cows during milking and in paddock), PMR1 (a partial mixed ration which contained the same supplement as Control but was offered to the cows as a partial mixed ration on a feedpad), PMR 2 (a differently formulated partial mixed ration compared to Control and PMR1 which was offered to the cows on a feedpad). Most of the yoghurt fatty acids were influenced by feeding systems; however, those effects were minor on organic acids. The differences in feeding systems did not lead to the formation of different volatile organic flavour compounds in yoghurt. Yet, it did influence the relative abundance of these components.

  17. High abundances of oxalic, azelaic, and glyoxylic acids and methylglyoxal in the open ocean with high biological activity: Implication for secondary OA formation from isoprene

    NASA Astrophysics Data System (ADS)

    Bikkina, Srinivas; Kawamura, Kimitaka; Miyazaki, Yuzo; Fu, Pingqing

    2014-05-01

    Atmospheric dicarboxylic acids (DCA) are a ubiquitous water-soluble component of secondary organic aerosols (SOA), which can act as cloud condensation nuclei (CCN), affecting the Earth's climate. Despite the high abundances of oxalic acid and related compounds in the marine aerosols, there is no consensus on what controls their distributions over the open ocean. Marine biological productivity could play a role in the production of DCA, but there is no substantial evidence to support this hypothesis. Here we present latitudinal distributions of DCA, oxoacids and α-dicarbonyls in the marine aerosols from the remote Pacific. Their concentrations were found several times higher in more biologically influenced aerosols (MBA) than less biologically influenced aerosols. We propose isoprene and unsaturated fatty acids as sources of DCA as inferred from significantly higher abundances of isoprene-SOA tracers and azelaic acid in MBA. These results have implications toward the reassessment of climate forcing feedbacks of marine-derived SOA.

  18. Determination of non-volatile and volatile organic acids in Korean traditional fermented soybean paste (Doenjang).

    PubMed

    Shukla, Shruti; Choi, Tae Bong; Park, Hae-Kyong; Kim, Myunghee; Lee, In Koo; Kim, Jong-Kyu

    2010-01-01

    Organic acids are formed in food as a result of metabolism of large molecular mass compounds. These organic acids play an important role in the taste and aroma of fermented food products. Doenjang is a traditional Korean fermented soybean paste product that provides a major source of protein. The quantitative data for volatile and non-volatile organic acid contents of 18 samples of Doenjang were determined by comparing the abundances of each peak by gas (GC) and high performance liquid chromatography (HPLC). The mean values of volatile organic acids (acetic acid, butyric acid, propionic acid and 3-methyl butanoic acid), determined in 18 Doenjang samples, were found to be 91.73, 29.54, 70.07 and 19.80 mg%, respectively, whereas the mean values of non-volatile organic acids, such as oxalic acid, citric acid, lactic acid and succinic acid, were noted to be 14.69, 5.56, 9.95 and 0.21 mg%, respectively. Malonic and glutaric acids were absent in all the tested samples of Doenjang. The findings of this study suggest that determination of organic acid contents by GC and HPLC can be considered as an affective approach to evaluate the quality characteristics of fermented food products.

  19. Organic Nitrogen-Driven Stimulation of Arbuscular Mycorrhizal Fungal Hyphae Correlates with Abundance of Ammonia Oxidizers.

    PubMed

    Bukovská, Petra; Gryndler, Milan; Gryndlerová, Hana; Püschel, David; Jansa, Jan

    2016-01-01

    Large fraction of mineral nutrients in natural soil environments is recycled from complex and heterogeneously distributed organic sources. These sources are explored by both roots and associated mycorrhizal fungi. However, the mechanisms behind the responses of arbuscular mycorrhizal (AM) hyphal networks to soil organic patches of different qualities remain little understood. Therefore, we conducted a multiple-choice experiment examining hyphal responses to different soil patches within the root-free zone by two AM fungal species (Rhizophagus irregularis and Claroideoglomus claroideum) associated with Medicago truncatula, a legume forming nitrogen-fixing root nodules. Hyphal colonization of the patches was assessed microscopically and by quantitative real-time PCR (qPCR) using AM taxon-specific markers, and the prokaryotic and fungal communities in the patches (pooled per organic amendment treatment) were profiled by 454-amplicon sequencing. Specific qPCR markers were then designed and used to quantify the abundance of prokaryotic taxa showing the strongest correlation with the pattern of AM hyphal proliferation in the organic patches as per the 454-sequencing. The hyphal density of both AM fungi increased due to nitrogen (N)-containing organic amendments (i.e., chitin, DNA, albumin, and clover biomass), while no responses as compared to the non-amended soil patch were recorded for cellulose, phytate, or inorganic phosphate amendments. Abundances of several prokaryotes, including Nitrosospira sp. (an ammonium oxidizer) and an unknown prokaryote with affiliation to Acanthamoeba endosymbiont, which were frequently recorded in the 454-sequencing profiles, correlated positively with the hyphal responses of R. irregularis to the soil amendments. Strong correlation between abundance of these two prokaryotes and the hyphal responses to organic soil amendments by both AM fungi was then confirmed by qPCR analyses using all individual replicate patch samples. Further

  20. Organic Nitrogen-Driven Stimulation of Arbuscular Mycorrhizal Fungal Hyphae Correlates with Abundance of Ammonia Oxidizers

    PubMed Central

    Bukovská, Petra; Gryndler, Milan; Gryndlerová, Hana; Püschel, David; Jansa, Jan

    2016-01-01

    Large fraction of mineral nutrients in natural soil environments is recycled from complex and heterogeneously distributed organic sources. These sources are explored by both roots and associated mycorrhizal fungi. However, the mechanisms behind the responses of arbuscular mycorrhizal (AM) hyphal networks to soil organic patches of different qualities remain little understood. Therefore, we conducted a multiple-choice experiment examining hyphal responses to different soil patches within the root-free zone by two AM fungal species (Rhizophagus irregularis and Claroideoglomus claroideum) associated with Medicago truncatula, a legume forming nitrogen-fixing root nodules. Hyphal colonization of the patches was assessed microscopically and by quantitative real-time PCR (qPCR) using AM taxon-specific markers, and the prokaryotic and fungal communities in the patches (pooled per organic amendment treatment) were profiled by 454-amplicon sequencing. Specific qPCR markers were then designed and used to quantify the abundance of prokaryotic taxa showing the strongest correlation with the pattern of AM hyphal proliferation in the organic patches as per the 454-sequencing. The hyphal density of both AM fungi increased due to nitrogen (N)-containing organic amendments (i.e., chitin, DNA, albumin, and clover biomass), while no responses as compared to the non-amended soil patch were recorded for cellulose, phytate, or inorganic phosphate amendments. Abundances of several prokaryotes, including Nitrosospira sp. (an ammonium oxidizer) and an unknown prokaryote with affiliation to Acanthamoeba endosymbiont, which were frequently recorded in the 454-sequencing profiles, correlated positively with the hyphal responses of R. irregularis to the soil amendments. Strong correlation between abundance of these two prokaryotes and the hyphal responses to organic soil amendments by both AM fungi was then confirmed by qPCR analyses using all individual replicate patch samples. Further

  1. Photoenhanced anaerobic digestion of organic acids

    DOEpatents

    Weaver, Paul F.

    1990-01-01

    A process is described for rapid conversion of organic acids and alcohols anaerobic digesters into hydrogen and carbon dioxide, the optimal precursor substrates for production of methane. The process includes addition of photosynthetic bacteria to the digester and exposure of the bacteria to radiant energy (e.g., solar energy). The process also increases the pH stability of the digester to prevent failure of the digester. Preferred substrates for photosynthetic bacteria are the organic acid and alcohol waste products of fermentative bacteria. In mixed culture with methanogenic bacteria or in defined co-culture with non-aceticlastic methanogenic bacteria, photosynthetic bacteria are capable of facilitating the conversion or organic acids and alcohols into methane with low levels of light energy input.

  2. Chemoselective single-site Earth-abundant metal catalysts at metal–organic framework nodes

    PubMed Central

    Manna, Kuntal; Ji, Pengfei; Lin, Zekai; Greene, Francis X.; Urban, Ania; Thacker, Nathan C.; Lin, Wenbin

    2016-01-01

    Earth-abundant metal catalysts are critically needed for sustainable chemical synthesis. Here we report a simple, cheap and effective strategy of producing novel earth-abundant metal catalysts at metal–organic framework (MOF) nodes for broad-scope organic transformations. The straightforward metalation of MOF secondary building units (SBUs) with cobalt and iron salts affords highly active and reusable single-site solid catalysts for a range of organic reactions, including chemoselective borylation, silylation and amination of benzylic C–H bonds, as well as hydrogenation and hydroboration of alkenes and ketones. Our structural, spectroscopic and kinetic studies suggest that chemoselective organic transformations occur on site-isolated, electron-deficient and coordinatively unsaturated metal centres at the SBUs via σ-bond metathesis pathways and as a result of the steric environment around the catalytic site. MOFs thus provide a novel platform for the development of highly active and affordable base metal catalysts for the sustainable synthesis of fine chemicals. PMID:27574182

  3. A toy model of prebiotic peptide evolution: the possible role of relative amino acid abundances.

    PubMed

    Polanco, Carlos; Buhse, Thomas; Samaniego, José Lino; Castañón González, Jorge Alberto

    2013-01-01

    This paper presents a mathematical-computational toy model based on the assumed dynamic principles of prebiotic peptide evolution. Starting from a pool of amino acid monomers, the model describes in a generalized manner the generation of peptides and their sequential information. The model integrates the intrinsic and dynamic key elements of the initiation of biopolymerization, such as the relative amino acid abundances and polarities, as well as the oligomer reversibility, i.e. fragmentation and recombination, and peptide self-replication. Our modeling results suggest that the relative amino acid abundances, as indicated by Miller-Urey type electric discharge experiments, played a principal role in the early sequential information of peptide profiles. Moreover, the computed profiles display an astonishing similarity to peptide profiles observed in so-called biological common ancestors found in the following three microorganisms; E. coli, M. jannaschii, and S. cereviasiae. The prebiotic peptide fingerprint was obtained by the so-called polarity index method that was earlier reported as a tool for the identification of cationic amphipathic antibacterial short peptides.

  4. Tracing the source of cooking oils with an integrated approach of using stable carbon isotope and fatty acid abundance.

    PubMed

    Liu, Weiguo; Yang, Hong; Wang, Zheng; Liu, Jinzhao

    2012-08-15

    We report a new approach to identify swill-cooked oils that are recycled from tainted food and livestock waste from commercial vegetable and animal oils by means of carbon isotope values and relative abundance of fatty acids. We test this method using 40 cooking oil samples of different types with known sources. We found significant differences in both total organic carbon isotope as well as compound-specific isotope values and fatty acid C(14)/C(18) ratios between commercial vegetable oils refined from C(3) plants (from -35.7 to -27.0‰ and from 0 to 0.15) and animal oils (from -28.3 to -14.3‰ and from 0.1 to 0.6). Tested swill-cooked oils, which were generally refined by mixing with animal waste illegally, fall into a narrow δ(13)C/fatty acid ratio distribution: from -25.9 to -24.1‰ and from 0.1 to 0.2. Our data demonstrate that the index of a cross-plotting between fatty acid δ(13)C values and C(14)/C(18) ratios can be used to distinguish clean commercial cooking oils from illegal swill-cooked oils.

  5. High-resolution NMR of hydrogen in organic solids by DNP enhanced natural abundance deuterium spectroscopy

    NASA Astrophysics Data System (ADS)

    Rossini, Aaron J.; Schlagnitweit, Judith; Lesage, Anne; Emsley, Lyndon

    2015-10-01

    We demonstrate that high field (9.4 T) dynamic nuclear polarization (DNP) at cryogenic (∼100 K) sample temperatures enables the rapid acquisition of natural abundance 1H-2H cross-polarization magic angle spinning (CPMAS) solid-state NMR spectra of organic solids. Spectra were obtained by impregnating substrates with a solution of the stable DNP polarizing agent TEKPol in tetrachloroethane. Tetrachloroethane is a non-solvent for the solids, and the unmodified substrates are then polarized through spin diffusion. High quality natural abundance 2H CPMAS spectra of histidine hydrochloride monohydrate, glycylglycine and theophylline were acquired in less than 2 h, providing direct access to hydrogen chemical shifts and quadrupolar couplings. The spectral resolution of the 2H solid-state NMR spectra is comparable to that of 1H spectra obtained with state of the art homonuclear decoupling techniques.

  6. Determination of Natural 14C Abundances in Dissolved Organic Carbon in Organic-Rich Marine Sediment Porewaters by Thermal Sulfate Reduction

    NASA Astrophysics Data System (ADS)

    Johnson, L.; Komada, T.

    2010-12-01

    The abundances of natural 14C in dissolved organic carbon (DOC) in the marine environment hold clues regarding the processes that influence the biogeochemical cycling of this large carbon reservoir. At present, UV irradiation is the widely accepted method for oxidizing seawater DOC for determination of their 14C abundances. This technique yields precise and accurate values with low blanks, but it requires a dedicated vacuum line, and hence can be difficult to implement. As an alternative technique that can be conducted on a standard preparatory vacuum line, we modified and tested a thermal sulfate reduction method that was previously developed to determine δ13C values of marine DOC (Fry B. et al., 1996. Analysis of marine DOC using a dry combustion method. Mar. Chem., 54: 191-201.) to determine the 14C abundances of DOC in marine sediment porewaters. In this method, the sample is dried in a 100 ml round-bottom Pyrex flask in the presence of excess oxidant (K2SO4) and acid (H3PO4), and combusted at 550 deg.C. The combustion products are cryogenically processed to collect and quantify CO2 using standard procedures. Materials we have oxidized to date range from 6-24 ml in volume, and 95-1500 μgC in size. The oxidation efficiency of this method was tested by processing known amounts of reagent-grade dextrose and sucrose (as examples of labile organic matter), tannic acid and humic acid (as examples of complex natural organic matter), and porewater DOC extracted from organic-rich nearshore sediments. The carbon yields for all of these materials averaged 99±4% (n=18). The 14C abundances of standard materials IAEA C-6 and IAEA C-5 processed by this method using >1mgC aliquots were within error of certified values. The size and the isotopic value of the blank were determined by a standard dilution technique using IAEA C-6 and IAEA C-5 that ranged in size from 150 to 1500 μgC (n=4 and 2, respectively). This yielded a blank size of 6.7±0.7 μgC, and a blank isotopic

  7. Distinctive lipid composition of the copepod Limnocalanus macrurus with a high abundance of polyunsaturated fatty acids.

    PubMed

    Hiltunen, Minna; Strandberg, Ursula; Keinänen, Markku; Taipale, Sami; Kankaala, Paula

    2014-09-01

    We studied the copepod Limnocalanus macrurus for seasonal variation in the composition of fatty acids, wax esters and sterols in large boreal lakes, where it occurs as a glacial-relict. Vast wax ester reserves of Limnocalanus were accumulated in a period of only two months, and comprised mono- and polyunsaturated fatty acids (PUFA) and saturated fatty alcohols. In winter, the mobilization of wax esters was selective, and the proportion of long-chain polyunsaturated wax esters declined first. PUFA accounted for >50% of all fatty acids throughout the year reaching up to ca. 65% during late summer and fall. Long-chain PUFA 20:5n-3 and 22:6n-3 together comprised 17-40% of all fatty acids. The rarely reported C24 and C26 very-long-chain PUFA (VLC-PUFA) comprised 6.2 ± 3.4 % of all fatty acids in August and 2.1 ± 1.7% in September. The VLC-PUFA are presumably synthesized by Limnocalanus from shorter chain-length precursors because they were not found in the potential food sources. We hypothesize that these VLC-PUFA help Limnocalanus to maximize lipid reserves when food is abundant. Sterol content of Limnocalanus, consisting ca. 90% of cholesterol, did not show great seasonal variation. As a lipid-rich copepod with high abundance of PUFA, Limnocalanus is excellent quality food for fish. The VLC-PUFA were also detected in planktivorous fish, suggesting that these compounds can be used as a trophic marker indicating feeding on Limnocalanus.

  8. Constraining the Abundances of Complex Organics in the Inner Regions of Solar-type Protostars

    NASA Astrophysics Data System (ADS)

    Taquet, Vianney; López-Sepulcre, Ana; Ceccarelli, Cecilia; Neri, Roberto; Kahane, Claudine; Charnley, Steven B.

    2015-05-01

    The high abundances of Complex Organic Molecules (COMs) with respect to methanol, the most abundant COM, detected toward low-mass protostars, tend to be underpredicted by astrochemical models. This discrepancy might come from the large beam of the single-dish telescopes, encompassing several components of the studied protostar, commonly used to detect COMs. To address this issue, we have carried out multi-line observations of methanol and several COMs toward the two low-mass protostars NGC 1333-IRAS 2A and -IRAS 4A with the Plateau de Bure interferometer at an angular resolution of 2″, resulting in the first multi-line detection of the O-bearing species glycolaldehyde and ethanol and of the N-bearing species ethyl cyanide toward low-mass protostars other than IRAS 16293. The high number of detected transitions from COMs (more than 40 methanol transitions for instance) allowed us to accurately derive the source size of their emission and the COM column densities. The COM abundances with respect to methanol derived toward IRAS 2A and IRAS 4A are slightly, but not substantitally, lower than those derived from previous single-dish observations. The COM abundance ratios do not vary significantly with the protostellar luminosity, over five orders of magnitude, implying that low-mass hot corinos are quite chemically rich as high-mass hot cores. Astrochemical models still underpredict the abundances of key COMs, such as methyl formate or di-methyl ether, suggesting that our understanding of their formation remains incomplete.

  9. Probabilisitc Geobiological Classification Using Elemental Abundance Distributions and Lossless Image Compression in Recent and Modern Organisms

    NASA Technical Reports Server (NTRS)

    Storrie-Lombardi, Michael C.; Hoover, Richard B.

    2005-01-01

    Last year we presented techniques for the detection of fossils during robotic missions to Mars using both structural and chemical signatures[Storrie-Lombardi and Hoover, 2004]. Analyses included lossless compression of photographic images to estimate the relative complexity of a putative fossil compared to the rock matrix [Corsetti and Storrie-Lombardi, 2003] and elemental abundance distributions to provide mineralogical classification of the rock matrix [Storrie-Lombardi and Fisk, 2004]. We presented a classification strategy employing two exploratory classification algorithms (Principal Component Analysis and Hierarchical Cluster Analysis) and non-linear stochastic neural network to produce a Bayesian estimate of classification accuracy. We now present an extension of our previous experiments exploring putative fossil forms morphologically resembling cyanobacteria discovered in the Orgueil meteorite. Elemental abundances (C6, N7, O8, Na11, Mg12, Ai13, Si14, P15, S16, Cl17, K19, Ca20, Fe26) obtained for both extant cyanobacteria and fossil trilobites produce signatures readily distinguishing them from meteorite targets. When compared to elemental abundance signatures for extant cyanobacteria Orgueil structures exhibit decreased abundances for C6, N7, Na11, All3, P15, Cl17, K19, Ca20 and increases in Mg12, S16, Fe26. Diatoms and silicified portions of cyanobacterial sheaths exhibiting high levels of silicon and correspondingly low levels of carbon cluster more closely with terrestrial fossils than with extant cyanobacteria. Compression indices verify that variations in random and redundant textural patterns between perceived forms and the background matrix contribute significantly to morphological visual identification. The results provide a quantitative probabilistic methodology for discriminating putatitive fossils from the surrounding rock matrix and &om extant organisms using both structural and chemical information. The techniques described appear applicable

  10. CONSTRAINING THE ABUNDANCES OF COMPLEX ORGANICS IN THE INNER REGIONS OF SOLAR-TYPE PROTOSTARS

    SciTech Connect

    Taquet, Vianney; Charnley, Steven B.; López-Sepulcre, Ana; Ceccarelli, Cecilia; Kahane, Claudine; Neri, Roberto

    2015-05-10

    The high abundances of Complex Organic Molecules (COMs) with respect to methanol, the most abundant COM, detected toward low-mass protostars, tend to be underpredicted by astrochemical models. This discrepancy might come from the large beam of the single-dish telescopes, encompassing several components of the studied protostar, commonly used to detect COMs. To address this issue, we have carried out multi-line observations of methanol and several COMs toward the two low-mass protostars NGC 1333-IRAS 2A and -IRAS 4A with the Plateau de Bure interferometer at an angular resolution of 2″, resulting in the first multi-line detection of the O-bearing species glycolaldehyde and ethanol and of the N-bearing species ethyl cyanide toward low-mass protostars other than IRAS 16293. The high number of detected transitions from COMs (more than 40 methanol transitions for instance) allowed us to accurately derive the source size of their emission and the COM column densities. The COM abundances with respect to methanol derived toward IRAS 2A and IRAS 4A are slightly, but not substantitally, lower than those derived from previous single-dish observations. The COM abundance ratios do not vary significantly with the protostellar luminosity, over five orders of magnitude, implying that low-mass hot corinos are quite chemically rich as high-mass hot cores. Astrochemical models still underpredict the abundances of key COMs, such as methyl formate or di-methyl ether, suggesting that our understanding of their formation remains incomplete.

  11. Stability of organic acids on Mars

    NASA Astrophysics Data System (ADS)

    Peeters, Zan; Hudson, R.; Moore, M.

    2009-09-01

    Mars receives an influx of carbonaceous material by fine-grained meteoritic impact of 2.4×105 kg carbon per year. Carbonaceous meteorites are known to contain amino acids, up to 249 ppm in primitive CR type meteorites, with glycine abundances as high as 58 ppm. These meteorite-bound amino acids arrive on Mars and may be distributed over the planet aeolian processes. Once on the surface, amino acids can be degraded rapidly by ultraviolet (UV) photolysis and reactions with oxidizing species such as H, OH, HO2, and H2O2. To test the influence of a water matrix on the stability of glycine on Mars, we have photolysed pure glycine and glycine-water ice mixtures (1:4) with a high-pressure xenon arc lamp that produces a spectrum similar to the solar spectrum on Mars. The ices were photolysed at temperatures relevant to Mars, especially at higher latitudes (100-150 K). For comparison, we repeated these experiments with acetic acid (CH3COOH) and formic acid (HCOOH). In addition, we also photolysed solid carbonic acid (H2CO3), which may be formed on Mars in mixed water and CO2 ices when initiated by solar wind particles. Our results show that carbonic acid is an order of magnitude more stable than formic and acetic acid. The glycine-water mixture did not show any degradation over the course of the photolysis experiment. This work is supported by NASA grant NNG05GL46G and the Goddard Center for Astrobiology.

  12. Nondestructive, in situ, cellular-scale mapping of elemental abundances including organic carbon in permineralized fossils.

    PubMed

    Boyce, C K; Hazen, R M; Knoll, A H

    2001-05-22

    The electron microprobe allows elemental abundances to be mapped at the microm scale, but until now high resolution mapping of light elements has been challenging. Modifications of electron microprobe procedure permit fine-scale mapping of carbon. When applied to permineralized fossils, this technique allows simultaneous mapping of organic material, major matrix-forming elements, and trace elements with microm-scale resolution. The resulting data make it possible to test taphonomic hypotheses for the formation of anatomically preserved silicified fossils, including the role of trace elements in the initiation of silica precipitation and in the prevention of organic degradation. The technique allows one to understand the localization of preserved organic matter before undertaking destructive chemical analyses and, because it is nondestructive, offers a potentially important tool for astrobiological investigations of samples returned from Mars or other solar system bodies.

  13. ANALYSIS OF RICIN TOXIN PREPARATIONS FOR CARBOHYDRATE AND FATTY ACID ABUNDANCE AND ISOTOPE RATIO INFORMATION

    SciTech Connect

    Wunschel, David S.; Kreuzer-Martin, Helen W.; Antolick, Kathryn C.; Colburn, Heather A.; Moran, James J.; Melville, Angela M.

    2009-12-01

    This report describes method development and preliminary evaluation for analyzing castor samples for signatures of purifying ricin. Ricin purification from the source castor seeds is essentially a problem of protein purification using common biochemical methods. Indications of protein purification will likely manifest themselves as removal of the non-protein fractions of the seed. Two major, non-protein, types of biochemical constituents in the seed are the castor oil and various carbohydrates. The oil comprises roughly half the seed weight while the carbohydrate component comprises roughly half of the remaining “mash” left after oil and hull removal. Different castor oil and carbohydrate components can serve as indicators of specific toxin processing steps. Ricinoleic acid is a relatively unique fatty acid in nature and is the most abundant component of castor oil. The loss of ricinoleic acid indicates a step to remove oil from the seeds. The relative amounts of carbohydrates and carbohydrate-like compounds, including arabinose, xylose, myo-inositol fucose, rhamnose, glucosamine and mannose detected in the sample can also indicate specific processing steps. For instance, the differential loss of arabinose relative to mannose and N-acetyl glucosamine indicates enrichment for the protein fraction of the seed using protein precipitation. The methods developed in this project center on fatty acid and carbohydrate extraction from castor samples followed by derivatization to permit analysis by gas chromatography-mass spectrometry (GC-MS). Method descriptions herein include: the source and preparation of castor materials used for method evaluation, the equipment and description of procedure required for chemical derivatization, and the instrument parameters used in the analysis. Two types of derivatization methods describe analysis of carbohydrates and one procedure for analysis of fatty acids. Two types of GC-MS analysis is included in the method development, one

  14. Acidic α-galactosidase is the most abundant nectarin in floral nectar of common tobacco (Nicotiana tabacum)

    PubMed Central

    Zha, Hong-Guang; Flowers, V. Lynn; Yang, Min; Chen, Ling-Yang; Sun, Hang

    2012-01-01

    Background and Aims To date, most floral nectarins (nectar proteins) are reported to function in nectar defence, particularly for insect-pollinated outcrossing species. We compared nectarin composition and abundance in selfing common tobacco (Nicotiana tobaccum) with outcrossing ornamental tobacco plants to elucidate the functional difference of nectarins in different reproductive systems. Methods Common tobacco (CT) nectarins were separated by SDS-PAGE and the N terminus of the most abundant nectarin was sequenced via Edman degradation. The full-length nectarin gene was amplified and cloned from genomic DNA and mRNA with hiTail-PCR and RACE (rapid amplification of cDNA ends), and expression patterns were then investigated in different tissues using semi-quantitative reverse transcriptase PCR. Additionally, high-performance liquid chromatography and enzymatic analyses of nectar sugar composition, and other biochemical traits and functions of the novel nectarin were studied. Key Results The most abundant nectarin in CT nectar is an acidic α-galactosidase, here designated NTα-Gal. This compound has a molecular mass of 40 013 Da and a theoretical pI of 5·33. NTα-Gal has a conserved α-Gal characteristic signature, encodes a mature protein of 364 amino acids and is expressed in different organs. Compared with 27 other melliferous plant species from different families, CT floral nectar demonstrated the highest α-Gal activity, which is inhibited by d-galactose. Raffinose family oligosaccharides were not detected in CT nectar, indicating that NTα-Gal does not function in post-secretory hydrolysis. Moreover, tobacco plant fruits did not develop intact skin with galactose inhibition of NTα-Gal activity in nectar, suggesting that NTα-Gal induces cell-wall surface restructuring during the initial stages of fruit development. Conclusions α-Gal was the most abundant nectarin in selfing CT plants, but was not detected in the nectar of strictly outcrossing sister tobacco

  15. Orchid bees as bio-indicators for organic coffee farms in Costa Rica: does farm size affect their abundance?

    PubMed

    Hedström, Ingemar; Denzel, Andrew; Owens, Gareth

    2006-09-01

    The potential of Euglossini bees, especially Euglossa, as biological indicators of organic vs nonorganic coffee farms was studied in Atenas and San Isidro, Alajuela, Costa Rica using 1.8-cineole as lure. Observations were made for three days at each of four farms and complemented with data from a year of observations. Orchid bees were in greater abundance in the organic farms (t-Student test). However, lower abundances suggest that an organic farm may be negatively affected by the proximity of non-organic farms, depending on its size and distance. Orchid bees may be indicators of organic coffee farms.

  16. Use of commercial organic fertilizer increases the abundance of antibiotic resistance genes and antibiotics in soil.

    PubMed

    Zhou, Xue; Qiao, Min; Wang, Feng-Hua; Zhu, Yong-Guan

    2017-01-01

    The application of manure-based commercial organic fertilizers (COFs) is becoming increasingly extensive because of the expanding market for organic food. The present study examined the effects of repeated applications of chicken or swine manure-based COFs on the fate of antibiotics and antibiotic resistance genes (ARGs) in soil by conducting a soil microcosm experiment. Application of COFs significantly increased antibiotics residues, as well as the relative abundance of ARGs and the integrase gene of class 1 integrons (intΙ1) in soil. Two months after each application, antibiotics and ARGs dissipated in amended soils, but they still remained at an elevated level, compared with the control. And, the accumulation of antibiotics was found due to repeated COF applications. However, the relative abundance of ARGs in most COF-amended soils did not differ significantly between the first application and the repeated application. The results imply that 2 months are not sufficient for ARGs to approach background levels, and that animal manure must be treated more effectively prior to using it in agriculture ecosystems.

  17. The earthworm Aporrectodea caliginosa stimulates abundance and activity of phenoxyalkanoic acid herbicide degraders

    PubMed Central

    Liu, Ya-Jun; Zaprasis, Adrienne; Liu, Shuang-Jiang; Drake, Harold L; Horn, Marcus A

    2011-01-01

    2-Methyl-4-chlorophenoxyacetic acid (MCPA) is a widely used phenoxyalkanoic acid (PAA) herbicide. Earthworms represent the dominant macrofauna and enhance microbial activities in many soils. Thus, the effect of the model earthworm Aporrectodea caliginosa (Oligochaeta, Lumbricidae) on microbial MCPA degradation was assessed in soil columns with agricultural soil. MCPA degradation was quicker in soil with earthworms than without earthworms. Quantitative PCR was inhibition-corrected per nucleic acid extract and indicated that copy numbers of tfdA-like and cadA genes (both encoding oxygenases initiating aerobic PAA degradation) in soil with earthworms were up to three and four times higher than without earthworms, respectively. tfdA-like and 16S rRNA gene transcript copy numbers in soil with earthworms were two and six times higher than without earthworms, respectively. Most probable numbers (MPNs) of MCPA degraders approximated 4 × 105 gdw−1 in soil before incubation and in soil treated without earthworms, whereas MPNs of earthworm-treated soils were approximately 150 × higher. The aerobic capacity of soil to degrade MCPA was higher in earthworm-treated soils than in earthworm-untreated soils. Burrow walls and 0–5 cm depth bulk soil displayed higher capacities to degrade MCPA than did soil from 5–10 cm depth bulk soil, expression of tfdA-like genes in burrow walls was five times higher than in bulk soil and MCPA degraders were abundant in burrow walls (MPNs of 5 × 107 gdw−1). The collective data indicate that earthworms stimulate abundance and activity of MCPA degraders endogenous to soil by their burrowing activities and might thus be advantageous for enhancing PAA degradation in soil. PMID:20740027

  18. Identification, abundance and origin of atmospheric organic particulate matter in a Portuguese rural area

    NASA Astrophysics Data System (ADS)

    Pio, C. A.; Alves, C. A.; Duarte, A. C.

    Respirable suspended particles high-volume samples were collected from a coastal-rural site in the centre of Portugal in August 1997 and their solvent-extractable organic compounds were subjected to characterisation by gas chromatography-mass spectrometry. Particles were also analysed by a thermal/optical technique in order to determine their black and organic carbon content. The total lipid extract yields ranged from 20 to 63 μg m -3, containing mainly aliphatic hydrocarbons such as n-alkanes, acids, alcohols, aldehydes, ketones and polycyclic aromatic hydrocarbons. The higher input of vascular plant wax components was demonstrated by the distribution patterns of the n-alkanes, n-alkanoic acids and n-alkanols homologous series, with C max at C 29, C 22/C 24 and C 30, respectively. The CPI values for these series were in the range 1.8-9.7, being indicative of recent biogenic input from microbial lipid residues and flora epicuticular components. Specific natural constituents (e.g. phytosterols, terpenes, etc.) were identified as molecular markers. Some oxidation products from volatile organic precursors were also present in the aerosols. In addition, all samples had a component of petroleum hydrocarbons representing urban and vehicular emissions probably transported from the nearest cities and from the motorway in the vicinity. This data set could be used to make a mass balance with organic carbon, organic extracts and elutable matter, permitting also the comparison with lipid signatures observed for other regions.

  19. The abiotic degradation of soil organic matter to oxalic acid

    NASA Astrophysics Data System (ADS)

    Studenroth, Sabine; Huber, Stefan; Schöler, H. F.

    2010-05-01

    The abiotic degradation of soil organic matter to volatile organic compounds was studied intensely over the last years (Keppler et al., 2000; Huber et al., 2009). It was shown that soil organic matter is oxidised due to the presence of iron (III), hydrogen peroxide and chloride and thereby produces diverse alkyl halides, which are emitted into the atmosphere. The formation of polar halogenated compounds like chlorinated acetic acids which are relevant toxic environmental substances was also found in soils and sediments (Kilian et al., 2002). The investigation of the formation of other polar halogenated and non-halogenated compounds like diverse mono- and dicarboxylic acids is going to attain more and more importance. Due to its high acidity oxalic acid might have impacts on the environment e.g., nutrient leaching, plant diseases and negative influence on microbial growth. In this study, the abiotic formation of oxalic acid in soil is examined. For a better understanding of natural degradation processes mechanistic studies were conducted using the model compound catechol as representative for structural elements of the humic substances and its reaction with iron (III) and hydrogen peroxide. Iron is one of the most abundant elements on earth and hydrogen peroxide is produced by bacteria or through incomplete reduction of oxygen. To find suitable parameters for an optimal reaction and a qualitative and quantitative analysis method the following reaction parameters are varied: concentration of iron (III) and hydrogen peroxide, time dependence, pH-value and influence of chloride. Analysis of oxalic acid was performed employing an ion chromatograph equipped with a conductivity detector. The time dependent reaction shows a relatively fast formation of oxalic acid, the optimum yield is achieved after 60 minutes. Compared to the concentration of catechol an excess of hydrogen peroxide as well as a low concentration of iron (III) are required. In absence of chloride the

  20. T cell abundance in blood predicts acute organ toxicity in chemoradiotherapy for head and neck cancer

    PubMed Central

    Reichardt, Sybille D.; Rave-Fränk, Margret; Schirmer, Markus A.; Stadelmann, Christine; Canis, Martin; Wolff, Hendrik A.

    2016-01-01

    Treatment of head and neck squamous cell carcinoma (HNSCC) by chemoradiotherapy (CRT) often results in high-grade acute organ toxicity (HGAOT). As these adverse effects impair the patients' quality of life and the feasibility of the planned therapy, we sought to analyze immunological parameters in tumor material and blood samples obtained from 48 HNSCC patients in order to assess the potential to predict the individual acute organ toxicity. T cells in the tumor stroma were enriched in patients developing HGAOT whereas levels of soluble factors in the plasma and gene expression in whole blood did not coincide with the occurrence of acute organ toxicity. In contrast, the frequency and absolute numbers of selected leukocyte subpopulations measured in samples of peripheral blood mononuclear cells (PBMCs) directly before the beginning of CRT were significantly different in patients with HGAOT as compared to those without. When we validated several potential markers including the abundance of T cells in a small prospective study with 16 HNSCC patients, we were able to correctly predict acute organ toxicity in up to 81% of the patients. We conclude that analysis of PBMCs by fluorescence-activated cell sorting (FACS) might be a convenient strategy to identify patients at risk of developing HGAOT caused by CRT, which might allow to adapt the treatment regimen and possibly improve disease outcome. PMID:27589568

  1. Inorganic nitrogen supply and dissolved organic nitrogen abundance across the US Great Plains.

    PubMed

    Mobley, Megan L; Cleary, Matthew J; Burke, Ingrid C

    2014-01-01

    Across US Great Plains grasslands, a gradient of increasing mean annual precipitation from west to east corresponds to increasing aboveground net primary productivity (ANPP) and increasing N-limitation. Previous work has shown that there is no increase in net N mineralization rates across this gradient, leading to the question of where eastern prairie grasses obtain the nitrogen to support production. One as-yet unexamined source is soil organic N, despite abundant literature from other ecosystems showing that plants take up dissolved soil organic N. This study measured KCl-extractable dissolved organic N (DON) in surface soils across the grassland productivity gradient. We found that KCl-extractable DON pools increased from west to east. If available to and used by plants, this DON may help explain the high ANPP in the eastern Great Plains. These results suggest a need for future research to determine whether, in what quantities, and in what forms prairie grasses use organic N to support primary production.

  2. Energy densification of biomass-derived organic acids

    DOEpatents

    Wheeler, M. Clayton; van Walsum, G. Peter; Schwartz, Thomas J.; van Heiningen, Adriaan

    2013-01-29

    A process for upgrading an organic acid includes neutralizing the organic acid to form a salt and thermally decomposing the resulting salt to form an energy densified product. In certain embodiments, the organic acid is levulinic acid. The process may further include upgrading the energy densified product by conversion to alcohol and subsequent dehydration.

  3. Arachidonic acid mediates the formation of abundant alpha-helical multimers of alpha-synuclein

    NASA Astrophysics Data System (ADS)

    Iljina, Marija; Tosatto, Laura; Choi, Minee L.; Sang, Jason C.; Ye, Yu; Hughes, Craig D.; Bryant, Clare E.; Gandhi, Sonia; Klenerman, David

    2016-09-01

    The protein alpha-synuclein (αS) self-assembles into toxic beta-sheet aggregates in Parkinson’s disease, while it is proposed that αS forms soluble alpha-helical multimers in healthy neurons. Here, we have made αS multimers in vitro using arachidonic acid (ARA), one of the most abundant fatty acids in the brain, and characterized them by a combination of bulk experiments and single-molecule Fӧrster resonance energy transfer (sm-FRET) measurements. The data suggest that ARA-induced oligomers are alpha-helical, resistant to fibril formation, more prone to disaggregation, enzymatic digestion and degradation by the 26S proteasome, and lead to lower neuronal damage and reduced activation of microglia compared to the oligomers formed in the absence of ARA. These multimers can be formed at physiologically-relevant concentrations, and pathological mutants of αS form less multimers than wild-type αS. Our work provides strong biophysical evidence for the formation of alpha-helical multimers of αS in the presence of a biologically relevant fatty acid, which may have a protective role with respect to the generation of beta-sheet toxic structures during αS fibrillation.

  4. Predators alter community organization of coral reef cryptofauna and reduce abundance of coral mutualists

    NASA Astrophysics Data System (ADS)

    Stier, A. C.; Leray, M.

    2014-03-01

    Coral reefs are the most diverse marine systems in the world, yet our understanding of the processes that maintain such extraordinary diversity remains limited and taxonomically biased toward the most conspicuous species. Cryptofauna that live deeply embedded within the interstitial spaces of coral reefs make up the majority of reef diversity, and many of these species provide important protective services to their coral hosts. However, we know very little about the processes governing the diversity and composition of these less conspicuous but functionally important species. Here, we experimentally quantify the role of predation in driving the community organization of small fishes and decapods that live embedded within Pocillopora eydouxi, a structurally complex, reef-building coral found widely across the Indo-Pacific. We use surveys to describe the natural distribution of predators, and then, factorially manipulate two focal predator species to quantify the independent and combined effects of predator density and identity on P. eydouxi-dwelling cryptofauna. Predators reduced abundance (34 %), species richness (20 %), and modified species composition. Rarefaction revealed that observed reductions in species richness were primarily driven by changes in abundance. Additionally, the two predator species uniquely affected the beta diversity and composition of the prey assemblage. Predators reduced the abundance and modified the composition of a number of mutualist fishes and decapods, whose benefit to the coral is known to be both diversity- and density-dependent. We predict that the density and identity of predators present within P. eydouxi may substantially alter coral performance in the face of an increased frequency and intensity of natural and anthropogenic stressors.

  5. Dietary omega-3 fatty acids modulate large-scale systems organization in the rhesus macaque brain.

    PubMed

    Grayson, David S; Kroenke, Christopher D; Neuringer, Martha; Fair, Damien A

    2014-02-05

    Omega-3 fatty acids are essential for healthy brain and retinal development and have been implicated in a variety of neurodevelopmental disorders. This study used resting-state functional connectivity MRI to define the large-scale organization of the rhesus macaque brain and changes associated with differences in lifetime ω-3 fatty acid intake. Monkeys fed docosahexaenoic acid, the long-chain ω-3 fatty acid abundant in neural membranes, had cortical modular organization resembling the healthy human brain. In contrast, those with low levels of dietary ω-3 fatty acids had decreased functional connectivity within the early visual pathway and throughout higher-order associational cortex and showed impairment of distributed cortical networks. Our findings illustrate the similarity in modular cortical organization between the healthy human and macaque brain and support the notion that ω-3 fatty acids play a crucial role in developing and/or maintaining distributed, large-scale brain systems, including those essential for normal cognitive function.

  6. Effects of short-chain fatty acid-supplemented total parenteral nutrition on intestinal pro-inflammatory cytokine abundance.

    PubMed

    Milo, L A; Reardon, K A; Tappenden, K A

    2002-09-01

    We examined the effect of short-chain fatty acid-supplemented total parenteral nutrition on proinflammatory cytokine levels in piglets. Piglets (N = 22) received either standard total parenteral nutrition or total parenteral nutrition supplemented with short-chain fatty acids. After seven days of continuous nutrient infusion, proinflammatory cytokine (TNF-alpha, IL-1beta, IL-6) abundance in plasma, jejunal, and ileal samples and small intestinal myeloperoxidase was determined using western blotting. No differences were seen in TNF-alpha small intestinal abundance. IL-1beta was higher in the small intestine of the short-chain fatty acid group (P < 0.05). IL-6 was higher in intestinal samples of the short-chain fatty acid group (P = 0.05), with the ileum having a greater abundance of IL-6 than the jejunum (P < 0.005). No differences in proinflammatory cytokine abundance in the plasma or tissue myeloperoxidase were seen. These results indicate short-chain fatty acids beneficially increase small intestinal abundance of IL-1beta and IL-6 during total parenteral nutrition administration, while not affecting systemic production of these cytokines or intestinal inflammation.

  7. Effect of phenolic acids on glucose and organic acid metabolism by lactic acid bacteria from wine.

    PubMed

    Campos, Francisco M; Figueiredo, Ana R; Hogg, Tim A; Couto, José A

    2009-06-01

    The influence of phenolic (p-coumaric, caffeic, ferulic, gallic and protocatechuic) acids on glucose and organic acid metabolism by two strains of wine lactic acid bacteria (Oenococcus oeni VF and Lactobacillus hilgardii 5) was investigated. Cultures were grown in modified MRS medium supplemented with different phenolic acids. Cellular growth was monitored and metabolite concentrations were determined by HPLC-RI. Despite the strong inhibitory effect of most tested phenolic acids on the growth of O. oeni VF, the malolactic activity of this strain was not considerably affected by these compounds. While less affected in its growth, the capacity of L. hilgardii 5 to degrade malic acid was clearly diminished. Except for gallic acid, the addition of phenolic acids delayed the metabolism of glucose and citric acid in both strains tested. It was also found that the presence of hydroxycinnamic acids (p-coumaric, caffeic and ferulic) increased the yield of lactic and acetic acid production from glucose by O. oeni VF and not by L. hilgardii 5. The results show that important oenological characteristics of wine lactic acid bacteria, such as the malolactic activity and the production of volatile organic acids, may be differently affected by the presence of phenolic acids, depending on the bacterial species or strain.

  8. [Compositions of organic acids in PM10 emission sources in Xiamen urban atmosphere].

    PubMed

    Yang, Bing-Yu; Huang, Xing-Xing; Zheng, An; Liu, Bi-Lian; Wu, Shui-Ping

    2013-01-01

    The possible organic acid emission sources in PM10 in Xiamen urban atmosphere such as cooking, biomass burning, vehicle exhaust and soil/dust were obtained using a re-suspension test chamber. A total of 15 organic acids including dicarboxylic acids, fatty acids and aromatic acids were determined using GC/MS after derivatization with BF3/n-butanol. The results showed that the highest total concentration of 15 organic acids (53%) was found in cooking emission and the average concentration of the sum of linoleic acid and oleic acid was 24% +/- 14%. However, oxalic acid was the most abundant species followed by phthalic acid in gasoline vehicle exhaust. The ratios of adipic to azelaic acid in gasoline combustion emissions were significantly higher than those in other emission sources, which can be used to qualitatively differentiate anthropogenic and biological source of dicarboxylic acids in atmospheric samples. The ratios of malonic to succinic acid in source emissions (except gasoline generator emissions) were lower (0.07-0.44) than ambient PM10 samples (0.61-3.93), which can be used to qualitatively differentiate the primary source and the secondary source of dicarboxylic acids in urban PM10.

  9. Effects of multiple levels of social organization on survival and abundance.

    PubMed

    Ward, Eric J; Semmens, Brice X; Holmes, Elizabeth E; Balcomb Iii, Ken C

    2011-04-01

    Identifying how social organization shapes individual behavior, survival, and fecundity of animals that live in groups can inform conservation efforts and improve forecasts of population abundance, even when the mechanism responsible for group-level differences is unknown. We constructed a hierarchical Bayesian model to quantify the relative variability in survival rates among different levels of social organization (matrilines and pods) of an endangered population of killer whales (Orcinus orca). Individual killer whales often participate in group activities such as prey sharing and cooperative hunting. The estimated age-specific survival probabilities and survivorship curves differed considerably among pods and to a lesser extent among matrilines (within pods). Across all pods, males had lower life expectancy than females. Differences in survival between pods may be caused by a combination of factors that vary across the population's range, including reduced prey availability, contaminants in prey, and human activity. Our modeling approach could be applied to demographic rates for other species and for parameters other than survival, including reproduction, prey selection, movement, and detection probabilities.

  10. Degradation of organic acids by dairy lactic acid bacteria.

    PubMed

    Hegazi, F Z; Abo-Elnaga, I G

    1980-01-01

    One hundred and twelve different strains of lactic acid bacteria, belonging to the genera Leuconostoc, Streptococcus, and Lactobacillus, were examined for the ability to degrade 10 organic acids by detecting gas production, using the conventional Durham tube method. All the strains did not break down succinate, glutarate, 2-oxo-glutarate, and mucate. Malate, citrate, pyruvate, fumarate, tartrate, and gluconate were variably attacked. Streptococcus cremoiris AM2, ML8, and SK11 required glucose to produce gas from citrate, whereas Leuconostoc citrovorum and Streptococcus faecalis did not. Streptococcus cremoris differed from the other streptococci in not producing gas from gluconate. From all lactic acid bacteria examined, only Lactobacillus plantarum formed gas from tartarate. Determination of acetoin and diacetyl proved to be a more reliable evidence for assessing the degradation of pyruvate, compared with detection of gas production. Homofermentative lactobacilli and Leuconostoc citrovorum produced acetoin and diacetyl from pyruvate, whereas beta-bacteria did not, a character that would be of taxonomic value. Streptobacteria degraded pyruvate in the presence of glucose with lactate as the major product together with a mean acetate of 4.1%, ethanol 7.9%, acetoin 1.7%, and diacetyl 2.6% yield on a molar basis after 60 days at 30 degrees C. L. brevis produced acetate and lactate. Formation of diacetyl from pyruvate by lactic acid bacteria may play an important role in flavour development in fermenting dairy products, especially in cheese, where lactic acid bacteria usually predominate, and pyruvate is probably excreted in the breaking down of lactose and in the oxidative deamination of alanine by the accompanying microflora.

  11. Bacterial Growth, Necromass Turnover, And Endospore Abundance In The Deep Subseafloor Sediments Of The Greenland Shelf Using D:L Amino Acid Model.

    NASA Astrophysics Data System (ADS)

    Mhatre, S. S.; Braun, S.; Jaussi, M.; Røy, H.; Jørgensen, B. B.; Lomstein, B. A.

    2015-12-01

    The subsurface realm is colonized by a large number of microorganisms- about 3 × 1029. Microbial cells in these very stable and oligotrophic settings catabolize at a much slower rate than model organisms in nutrient rich cultures. The aim of this work was to use recently developed D:L-amino acid racemization model for studying the turnover times of microbial biomass and microbial necromass in a ~12,000 years old Greenland shelf marine sediment samples. Sediments were analyzed for total hydrolysable amino acids (THAA), the bacterial endospore marker dipicolinic acid (DPA), and amino acid enantiomers of aspartic acid. The percentage amino acid carbon content (%TAAC) and the percentage amino acid nitrogen content (%TAAN) were used for determining the degradation state of the organic matter. Endospores quantified using DPA quantification method were found to be as abundant as vegetative cells. The microbial necromass turnover times were thousand years, and biomass turnover times were in the range of tens to hundred years. Studies with deeper sediment cores will further improve our understanding of the energetic limits of life in the deep biosphere.

  12. Capture and release of acid-gasses with acid-gas binding organic compounds

    DOEpatents

    Heldebrant, David J; Yonker, Clement R; Koech, Phillip K

    2015-03-17

    A system and method for acid-gas capture wherein organic acid-gas capture materials form hetero-atom analogs of alkyl-carbonate when contacted with an acid gas. These organic-acid gas capture materials include combinations of a weak acid and a base, or zwitterionic liquids. This invention allows for reversible acid-gas binding to these organic binding materials thus allowing for the capture and release of one or more acid gases. These acid-gas binding organic compounds can be regenerated to release the captured acid gasses and enable these organic acid-gas binding materials to be reused. This enables transport of the liquid capture compounds and the release of the acid gases from the organic liquid with significant energy savings compared to current aqueous systems.

  13. One-pot synthesis of amino acid precursors with insoluble organic matter in planetesimals with aqueous activity.

    PubMed

    Kebukawa, Yoko; Chan, Queenie H S; Tachibana, Shogo; Kobayashi, Kensei; Zolensky, Michael E

    2017-03-01

    The exogenous delivery of organic molecules could have played an important role in the emergence of life on the early Earth. Carbonaceous chondrites are known to contain indigenous amino acids as well as various organic compounds and complex macromolecular materials, such as the so-called insoluble organic matter (IOM), but the origins of the organic matter are still subject to debate. We report that the water-soluble amino acid precursors are synthesized from formaldehyde, glycolaldehyde, and ammonia with the presence of liquid water, simultaneously with macromolecular organic solids similar to the chondritic IOM. Amino acid products from hydrothermal experiments after acid hydrolysis include α-, β-, and γ-amino acids up to five carbons, for which relative abundances are similar to those extracted from carbonaceous chondrites. One-pot aqueous processing from simple ubiquitous molecules can thus produce a wide variety of meteoritic organic matter from amino acid precursors to macromolecular IOM in chondrite parent bodies.

  14. One-pot synthesis of amino acid precursors with insoluble organic matter in planetesimals with aqueous activity

    PubMed Central

    Kebukawa, Yoko; Chan, Queenie H. S.; Tachibana, Shogo; Kobayashi, Kensei; Zolensky, Michael E.

    2017-01-01

    The exogenous delivery of organic molecules could have played an important role in the emergence of life on the early Earth. Carbonaceous chondrites are known to contain indigenous amino acids as well as various organic compounds and complex macromolecular materials, such as the so-called insoluble organic matter (IOM), but the origins of the organic matter are still subject to debate. We report that the water-soluble amino acid precursors are synthesized from formaldehyde, glycolaldehyde, and ammonia with the presence of liquid water, simultaneously with macromolecular organic solids similar to the chondritic IOM. Amino acid products from hydrothermal experiments after acid hydrolysis include α-, β-, and γ-amino acids up to five carbons, for which relative abundances are similar to those extracted from carbonaceous chondrites. One-pot aqueous processing from simple ubiquitous molecules can thus produce a wide variety of meteoritic organic matter from amino acid precursors to macromolecular IOM in chondrite parent bodies. PMID:28345041

  15. Effect of organic acids on shrimp pathogen, Vibrio harveyi.

    PubMed

    Mine, Saori; Boopathy, Raj

    2011-07-01

    Shrimp farming accounts for more than 40% of the world shrimp production. Luminous vibriosis is a shrimp disease that causes major economic losses in the shrimp industry as a result of massive shrimp kills due to infection. Some farms in the South Asia use antibiotics to control Vibrio harveyi, a responsible pathogen for luminous vibriosis. However, the antibiotic-resistant strain was found recently in many shrimp farms, which makes it necessary to develop alternative pathogen control methods. Short-chain fatty acids are metabolic products of organisms, and they have been used as food preservatives for a long time. Organic acids are also commonly added in feeds in animal husbandry, but not in aquaculture. In this study, growth inhibitory effects of short-chain fatty acids, namely formic acid, acetic acid, propionic acid, and butyric acid, on V. harveyi were investigated. Among four acids, formic acid showed the strongest inhibitory effect followed by acetic acid, propionic acid, and butyric acid. The minimum inhibitory concentration (MIC) of 0.035% formic acid suppressed growth of V. harveyi. The major inhibitory mechanism seems to be the pH effect of organic acids. The effective concentration 50 (EC50) values at 96 h inoculation for all organic acids were determined to be 0.023, 0.041, 0.03, and 0.066% for formic, acetic, propionic, and butyric acid, respectively. The laboratory study results are encouraging to formulate shrimp feeds with organic acids to control vibrio infection in shrimp aquaculture farms.

  16. Acidic organic compounds in beverage, food, and feed production.

    PubMed

    Quitmann, Hendrich; Fan, Rong; Czermak, Peter

    2014-01-01

    Organic acids and their derivatives are frequently used in beverage, food, and feed production. Acidic additives may act as buffers to regulate acidity, antioxidants, preservatives, flavor enhancers, and sequestrants. Beneficial effects on animal health and growth performance have been observed when using acidic substances as feed additives. Organic acids could be classified in groups according to their chemical structure. Each group of organic acids has its own specific properties and is used for different applications. Organic acids with low molecular weight (e.g. acetic acid, lactic acid, and citric acid), which are part of the primary metabolism, are often produced by fermentation. Others are produced more economically by chemical synthesis based on petrochemical raw materials on an industrial scale (e.g. formic acid, propionic and benzoic acid). Biotechnology-based production is of interest due to legislation, consumer demand for natural ingredients, and increasing environmental awareness. In the United States, for example, biocatalytically produced esters for food applications can be labeled as "natural," whereas identical conventional acid catalyst-based molecules cannot. Natural esters command a price several times that of non-natural esters. Biotechnological routes need to be optimized regarding raw materials and yield, microorganisms, and recovery methods. New bioprocesses are being developed for organic acids, which are at this time commercially produced by chemical synthesis. Moreover, new organic acids that could be produced with biotechnological methods are under investigation for food applications.

  17. Aliphatic, Cyclic, and Aromatic Organic Acids, Vitamins, and Carbohydrates in Soil: A Review

    PubMed Central

    Vranova, Valerie; Rejsek, Klement; Formanek, Pavel

    2013-01-01

    Organic acids, vitamins, and carbohydrates represent important organic compounds in soil. Aliphatic, cyclic, and aromatic organic acids play important roles in rhizosphere ecology, pedogenesis, food-web interactions, and decontamination of sites polluted by heavy metals and organic pollutants. Carbohydrates in soils can be used to estimate changes of soil organic matter due to management practices, whereas vitamins may play an important role in soil biological and biochemical processes. The aim of this work is to review current knowledge on aliphatic, cyclic, and aromatic organic acids, vitamins, and carbohydrates in soil and to identify directions for future research. Assessments of organic acids (aliphatic, cyclic, and aromatic) and carbohydrates, including their behaviour, have been reported in many works. However, knowledge on the occurrence and behaviour of D-enantiomers of organic acids, which may be abundant in soil, is currently lacking. Also, identification of the impact and mechanisms of environmental factors, such as soil water content, on carbohydrate status within soil organic matter remains to be determined. Finally, the occurrence of vitamins in soil and their role in biological and biochemical soil processes represent an important direction for future research. PMID:24319374

  18. Aliphatic, cyclic, and aromatic organic acids, vitamins, and carbohydrates in soil: a review.

    PubMed

    Vranova, Valerie; Rejsek, Klement; Formanek, Pavel

    2013-11-10

    Organic acids, vitamins, and carbohydrates represent important organic compounds in soil. Aliphatic, cyclic, and aromatic organic acids play important roles in rhizosphere ecology, pedogenesis, food-web interactions, and decontamination of sites polluted by heavy metals and organic pollutants. Carbohydrates in soils can be used to estimate changes of soil organic matter due to management practices, whereas vitamins may play an important role in soil biological and biochemical processes. The aim of this work is to review current knowledge on aliphatic, cyclic, and aromatic organic acids, vitamins, and carbohydrates in soil and to identify directions for future research. Assessments of organic acids (aliphatic, cyclic, and aromatic) and carbohydrates, including their behaviour, have been reported in many works. However, knowledge on the occurrence and behaviour of D-enantiomers of organic acids, which may be abundant in soil, is currently lacking. Also, identification of the impact and mechanisms of environmental factors, such as soil water content, on carbohydrate status within soil organic matter remains to be determined. Finally, the occurrence of vitamins in soil and their role in biological and biochemical soil processes represent an important direction for future research.

  19. Use of sequential sampling of amphipod abundance to classify the biotic integrity of acid-sensitive lakes

    NASA Astrophysics Data System (ADS)

    France, Robert

    1992-03-01

    A sequential sampling program using previously published zoobenthos data is described for ubiquitous, cost-effective biomonitoring of the effects of lake acidification. Spring densities of the littoral amphipod Hyalella azteca are quantitatively sorted into five abundance catagories. An essential step in the a priori definition of decision criteria is the stratification of proportional densities per unit macrophyte biomass in relation to aqueous total phosphorus concentrations. Density rankings were related to lake acidity and to detailed lake-specific information on patterns of Hyalella life history and acid tolerance. Incorporation of Hyalella abundance as a potential metric for the assessment of the biological integrity of acid-sensitive waters is recommended. The temporal integration of transient changes in spring meltwater chemistry is an important rationale for the development of such biomonitoring procedures.

  20. Role of organic acids in promoting colloidal transport of mercury from mine tailings

    USGS Publications Warehouse

    Slowey, A.J.; Johnson, S.B.; Rytuba, J.J.; Brown, Gordon E.

    2005-01-01

    A number of factors affect the transport of dissolved and paniculate mercury (Hg) from inoperative Hg mines, including the presence of organic acids in the rooting zone of vegetated mine waste. We examined the role of the two most common organic acids in soils (oxalic and citric acid) on Hg transport from such waste by pumping a mixed organic acid solution (pH 5.7) at 1 mL/min through Hg mine tailings columns. For the two total organic acid concentrations investigated (20 ??M and 1 mM), particle-associated Hg was mobilized, with the onset of paniculate Hg transport occurring later for the lower organic acid concentration. Chemical analyses of column effluent indicate that 98 wt % of Hg mobilized from the column was paniculate. Hg speciation was determined using extended X-ray absorption fine structure spectroscopy and transmission electron microscopy, showing that HgS minerals are dominant in the mobilized particles. Hg adsorbed to colloids is another likely mode of transport due to the abundance of Fe-(oxyhydr)oxides, Fe-sulfides, alunite, and jarosite in the tailings to which Hg(II) adsorbs. Organic acids produced by plants are likely to enhance the transport of colloid-associated Hg from vegetated Hg mine tailings by dissolving cements to enable colloid release. ?? 2005 American Chemical Society.

  1. The abundance and organization of polypeptides associated with antigens of the Rh blood group system.

    PubMed

    Gardner, B; Anstee, D J; Mawby, W J; Tanner, M J; von dem Borne, A E

    1991-06-01

    Twelve murine monoclonal antibodies, which react with human red cells of common Rh phenotype but give weak or negative reactions with Rh null erythrocytes, were used in quantitative binding assays and competitive binding assays to investigate the abundance and organization of polypeptides involved in the expression of antigens of the Rh blood group system. Antibodies of the R6A-type (R6A, BRIC-69, BRIC-207) and the 2D10-type (MB-2D10, LA18.18, LA23.40) recognize related structures and 100,000-200,000 molecules of each antibody bind maximally to erythrocytes of common Rh phenotype. Antibodies of the BRIC-125 type (BRICs 32, 122, 125, 126, 168, 211) recognize structures that are unrelated to those recognized by R6A-type and 2D10-type antibodies and between 10,000 and 50,000 antibody molecules bind maximally to erythrocytes of the common Rh phenotype. The binding of antibodies of the R6A-type and the 2D10-type, but not of antibodies of the BRIC-125-type could be partially inhibited by human anti-D antibodies (polyclonal and monoclonal) and a murine anti-e-like antibody. These results are consistent with evidence (Moore & Green 1987; Avent et al., 1988b) that the Rh blood group antigens are associated with a complex that comprises two groups of related polypeptides of M(r) 30,000 and M(r) 35,000-100,000, respectively, and suggest that there are 1-2 x 10(5) copies of this complex per erythrocyte. The polypeptide recognized by antibodies of the BRIC-125 type is likely to be associated with this complex.

  2. Purification Or Organic Acids Using Anion Exchange Chromatography.

    DOEpatents

    Ponnampalam; Elankovan

    2001-09-04

    Disclosed is a cost-effective method for purifying and acidifying carboxylic acids, including organic acids and amino acids. The method involves removing impurities by allowing the anionic form of the carboxylic acid to bind to an anion exchange column and washing the column. The carboxylic anion is displaced as carboxylic acid by washing the resin with a strong inorganic anion. This method is effective in removing organic carboxylic acids and amino acids from a variety of industrial sources, including fermentation broths, hydrolysates, and waste streams.

  3. [Determination of fatty acids and organic acids in Ranunculus ternatus Thunb using GC-MS].

    PubMed

    Chen, Jun; Yao, Cheng; Xia, Li-Ming; Ouyang, Ping-Kai

    2006-08-01

    The determination of fatty acids and organic acids in Chinese medicinal plant Ranunculus ternatus Thunb using GC-MS was studied. The Ranunculus ternatus Thunb from Henan province was cut into less than 20 mesh pieces, then extracted by petroleum ether or ether in refluxing and esteried, and finally was determined using GC-MS. The results show that there are 23 kinds of organic compounds in the Chinese medicinal plant Ranunculus ternatus Thunb from Henan, among which 15 kinds of fatty acids were identified, including myristic acid, palmitic acid, stearic acid, oleic acid, linolenic acid, eicosanoic acid, docosanoic acid etc. The unsaturated fatty acids and oleic acid account for 58.19% and 35.68% of the total organic compounds respectively. The kinds of fatty acid in petroleum ether extract and ether extract are the same.

  4. D-Amino Acids in Living Higher Organisms

    NASA Astrophysics Data System (ADS)

    Fujii, Noriko

    2002-04-01

    The homochirality of biological amino acids (L-amino acids) and of the RNA/DNA backbone (D-ribose) might have become established before the origin of life. It has been considered that D-amino acids and L-sugars were eliminated on the primitive Earth. Therefore, the presence and function of D-amino acids in living organisms have not been studied except for D-amino acids in the cell walls of microorganisms. However, D-amino acids were recently found in various living higher organisms in the form of free amino acids, peptides, and proteins. Free D-aspartate and D-serine are present and may have important physiological functions in mammals. D-amino acids in peptides are well known as opioid peptides and neuropeptides. In protein, D-aspartate residues increase during aging. This review deals with recent advances in the study of D-amino acids in higher organisms.

  5. Decrease in the abundance and viability of oceanic phytoplankton due to trace levels of complex mixtures of organic pollutants.

    PubMed

    Echeveste, Pedro; Dachs, Jordi; Berrojalbiz, Naiara; Agustí, Susana

    2010-09-01

    Long range atmospheric transport and deposition is a significant introduction pathway of organic pollutants to remote oceanic regions, leading to their subsequent accumulation in marine organisms. Persistent organic pollutants (POPs) bioconcentrate in planktonic food webs and these exert a biogeochemical control on the regional and global cycling of POPs. Therefore, an important issue is to determine whether the anthropogenic chemical perturbation of the biosphere introduced by the myriad of organic pollutants present in seawater influences phytoplankton abundance and productivity. The results reported here from five sets of experiments performed in the NE Atlantic Ocean show that there is a toxic effect induced by trace levels of complex mixtures of organic pollutants on phytoplankton oceanic communities. The levels of single pollutant, such as phenanthrene and pyrene, at which lethality of phytoplankton is observed are high in comparison to field levels. Complex mixtures of organic pollutants, however, have an important toxic effect on phytoplankton abundances, viability and concentrations of Chlorophyll a at pollutant concentrations 20-40 folds those found in the open ocean. The toxicity of these complex mixtures of organic pollutants exceeds by 10(3) times the toxicity expected for a single pollutant. Therefore, our results point out the need for a systematic investigation of the influence of complex mixtures of organic hydrophobic pollutants to oceanic phytoplankton communities, a perturbation not accounted for on previous assessments of anthropogenic pressures in the marine environment.

  6. Experimental particle formation rates spanning tropospheric sulfuric acid and ammonia abundances, ion production rates, and temperatures

    NASA Astrophysics Data System (ADS)

    Kürten, Andreas; Bianchi, Federico; Almeida, Joao; Kupiainen-Määttä, Oona; Dunne, Eimear M.; Duplissy, Jonathan; Williamson, Christina; Barmet, Peter; Breitenlechner, Martin; Dommen, Josef; Donahue, Neil M.; Flagan, Richard C.; Franchin, Alessandro; Gordon, Hamish; Hakala, Jani; Hansel, Armin; Heinritzi, Martin; Ickes, Luisa; Jokinen, Tuija; Kangasluoma, Juha; Kim, Jaeseok; Kirkby, Jasper; Kupc, Agnieszka; Lehtipalo, Katrianne; Leiminger, Markus; Makhmutov, Vladimir; Onnela, Antti; Ortega, Ismael K.; Petäjä, Tuukka; Praplan, Arnaud P.; Riccobono, Francesco; Rissanen, Matti P.; Rondo, Linda; Schnitzhofer, Ralf; Schobesberger, Siegfried; Smith, James N.; Steiner, Gerhard; Stozhkov, Yuri; Tomé, António; Tröstl, Jasmin; Tsagkogeorgas, Georgios; Wagner, Paul E.; Wimmer, Daniela; Ye, Penglin; Baltensperger, Urs; Carslaw, Ken; Kulmala, Markku; Curtius, Joachim

    2016-10-01

    Binary nucleation of sulfuric acid and water as well as ternary nucleation involving ammonia are thought to be the dominant processes responsible for new particle formation (NPF) in the cold temperatures of the middle and upper troposphere. Ions are also thought to be important for particle nucleation in these regions. However, global models presently lack experimentally measured NPF rates under controlled laboratory conditions and so at present must rely on theoretical or empirical parameterizations. Here with data obtained in the European Organization for Nuclear Research CLOUD (Cosmics Leaving OUtdoor Droplets) chamber, we present the first experimental survey of NPF rates spanning free tropospheric conditions. The conditions during nucleation cover a temperature range from 208 to 298 K, sulfuric acid concentrations between 5 × 105 and 1 × 109 cm-3, and ammonia mixing ratios from zero added ammonia, i.e., nominally pure binary, to a maximum of 1400 parts per trillion by volume (pptv). We performed nucleation studies under pure neutral conditions with zero ions being present in the chamber and at ionization rates of up to 75 ion pairs cm-3 s-1 to study neutral and ion-induced nucleation. We found that the contribution from ion-induced nucleation is small at temperatures between 208 and 248 K when ammonia is present at several pptv or higher. However, the presence of charges significantly enhances the nucleation rates, especially at 248 K with zero added ammonia, and for higher temperatures independent of NH3 levels. We compare these experimental data with calculated cluster formation rates from the Atmospheric Cluster Dynamics Code with cluster evaporation rates obtained from quantum chemistry.

  7. Gas chromatography-mass spectrometry profiles of urinary organic acids in healthy captive cheetahs (Acinonyx jubatus).

    PubMed

    Tordiffe, Adrian Stephen Wolferstan; van Reenen, Mari; Reyers, Fred; Mienie, Lodewyk Jacobus

    2017-04-01

    In captivity, cheetahs (Acinonyx jubatus) frequently suffer from several unusual chronic diseases that rarely occur in their free-ranging counterparts. In order to develop a better understanding of their metabolism and health we documented the urine organic acids of 41 apparently healthy captive cheetahs, in an untargeted metabolomic study, using gas chromatography-mass spectrometry. A total of 339 organic acids were detected and annotated. Phenolic compounds, thought to be produced by the anaerobic fermentation of aromatic amino acids in the distal colon, as well as their corresponding glycine conjugates, were present in high concentrations. The most abundant organic acids in the cheetahs' urine were an as yet unidentified compound and a novel cadaverine metabolite, tentatively identified as N(1),N(5)-dimethylpentane-1,5-diamine. Pantothenic acid and citramalic acid concentrations correlated negatively with age, while glutaric acid concentrations correlated positively with age, suggesting possible dysregulation of coenzyme A metabolism in older cheetahs. This study provides a baseline of urine organic acid reference values in captive cheetahs and suggests important avenues for future research in this species.

  8. Temporal Variations of Organic Acids in Sumac Fruit

    SciTech Connect

    Robbins, C.; Mulcahy, F.; Somayajula, K.; Edenborn, H.M.

    2006-10-01

    Extracts from staghorn sumac (Rhus typhina) fruits were obtained from fresh fruits obtained from June to October in two successive years. Total acidity, pH, and concentrations of malic and succinic acids determined using liquid chromatography were measured for each extract. Acidity and acid concentrations reached their maxima in late July, and declined slowly thereafter. Malic and succinic acid concentrations in the extracts reached maxima of about 4 and 0.2% (expressed per unit weight of fruit), respectively. Malic and succinic acids were the only organic acids observed in the extracts, and mass balance determinations indicate that these acids are most likely the only ones present in appreciable amounts.

  9. Sensitive determination of nucleic acids using organic nanoparticle fluorescence probes

    NASA Astrophysics Data System (ADS)

    Zhou, Yunyou; Bian, Guirong; Wang, Leyu; Dong, Ling; Wang, Lun; Kan, Jian

    2005-06-01

    This paper describes the preparation of organic nanoparticles by reprecipitation method under sonication and vigorous stirring. Transmission electron microscopy (TEM) was used to characterize the size and size distribution of the luminescent nanoparticles. Their average diameter was about 25 nm with a size variation of ±18%. The fluorescence decay lifetime of the nanoparticles also was determined on a self-equipped fluorospectrometer with laser light source. The lifetime (˜0.09 μs) of nanoparticles is about three times long as that of the monomer. The nanoparticles were in abundant of hydrophilic groups, which increased their miscibility in aqueous solution. These organic nanoparticles have high photochemical stability, excellent resistance to chemical degradation and photodegradation, and a good fluorescence quantum yield (25%). The fluorescence can be efficiently quenched by nucleic acids. Based on the fluorescence quenching of nanoparticles, a fluorescence quenching method was developed for determination of microamounts of nucleic acids by using the nanoparticles as a new fluorescent probe. Under optimal conditions, maximum fluorescence quenching is produced, with maximum excitation and emission wavelengths of 345 and 402 nm, respectively. Under optimal conditions, the calibration graphs are linear over the range 0.4-19.0 μg ml -1 for calf thymus DNA (ct-DNA) and 0.3-19.0 μg ml -1 for fish sperm DNA (fs-DNA). The corresponding detection limits are 0.25 μg ml -1 for ct-DNA and 0.17 μg ml -1 for fs-DNA. The relative standard deviation of six replicate measurements is 1.3-2.1%. The method is simple, rapid and sensitive with wide linear range. The recovery and relative standard deviation are very satisfactory.

  10. The effects of parent-body hydrothermal heating on amino acid abundances in CI-like chondrites

    NASA Astrophysics Data System (ADS)

    Burton, Aaron S.; Grunsfeld, Sarah; Elsila, Jamie E.; Glavin, Daniel P.; Dworkin, Jason P.

    2014-09-01

    We determined the amino acid abundances and enantiomeric compositions of the Antarctic CI1 carbonaceous chondrites Yamato (Y)-86029 and Y-980115, as well as the Ivuna and Orgueil CI1 carbonaceous chondrites by liquid chromatography with fluorescence detection and time-of-flight mass spectrometry. Y-86029 and Y-980115 both show evidence of parent-body heating (500-600 °C) in addition to aqueous alteration, while Ivuna and Orgueil only show evidence for aqueous alteration. In contrast to Ivuna and Orgueil, which each contain ˜70 nmol/g of amino acids in acid-hydrolyzed, water extracts, both heated Yamato CI meteorites contain only low levels of amino acids that were primarily L-enantiomers of proteinogenic amino acids, indicating that they are likely to be terrestrial in origin. Because indigenous amino acids have been found in meteorites that have experienced metamorphic temperatures of >1000 °C with only minimal aqueous alteration, heating alone is not sufficient to explain the lack of amino acids in Y-86029 and Y-980115. Rather, our data suggest that the combination of heating and aqueous alteration has a profound destructive effect on amino acids in meteorites. This finding has implications for the origins of amino acids and other molecules in the early evolution of our solar system.

  11. Terracidiphilus gabretensis gen. nov., sp. nov., an Abundant and Active Forest Soil Acidobacterium Important in Organic Matter Transformation

    PubMed Central

    García-Fraile, Paula; Benada, Oldrich; Cajthaml, Tomáš; Baldrian, Petr

    2015-01-01

    Understanding the activity of bacteria in coniferous forests is highly important, due to the role of these environments as a global carbon sink. In a study of the microbial biodiversity of montane coniferous forest soil in the Bohemian Forest National Park (Czech Republic), we succeeded in isolating bacterial strain S55T, which belongs to one of the most abundant operational taxonomic units (OTUs) in active bacterial populations, according to the analysis of RNA-derived 16S rRNA amplicons. The 16S rRNA gene sequence analysis showed that the species most closely related to strain S55T include Bryocella elongata SN10T (95.4% identity), Acidicapsa ligni WH120T (95.2% identity), and Telmatobacter bradus TPB6017T (95.0% identity), revealing that strain S55T should be classified within the phylum Acidobacteria, subdivision 1. Strain S55T is a rod-like bacterium that grows at acidic pH (3 to 6). Its phylogenetic, genotypic, phenotypic, and chemotaxonomic characteristics indicate that strain S55T corresponds to a new genus within the phylum Acidobacteria; thus, we propose the name Terracidiphilus gabretensis gen. nov., sp. nov. (strain S55T = NBRC 111238T = CECT 8791T). This strain produces extracellular enzymes implicated in the degradation of plant-derived biopolymers. Moreover, analysis of the genome sequence of strain S55T also reveals the presence of enzymatic machinery required for organic matter decomposition. Soil metatranscriptomic analyses found 132 genes from strain S55T being expressed in the forest soil, especially during winter. Our results suggest an important contribution of T. gabretensis S55T in the carbon cycle in the Picea abies coniferous forest. PMID:26546425

  12. Modeling the influence of organic acids on soil weathering

    USGS Publications Warehouse

    Lawrence, Corey R.; Harden, Jennifer W.; Maher, Kate

    2014-01-01

    Biological inputs and organic matter cycling have long been regarded as important factors in the physical and chemical development of soils. In particular, the extent to which low molecular weight organic acids, such as oxalate, influence geochemical reactions has been widely studied. Although the effects of organic acids are diverse, there is strong evidence that organic acids accelerate the dissolution of some minerals. However, the influence of organic acids at the field-scale and over the timescales of soil development has not been evaluated in detail. In this study, a reactive-transport model of soil chemical weathering and pedogenic development was used to quantify the extent to which organic acid cycling controls mineral dissolution rates and long-term patterns of chemical weathering. Specifically, oxalic acid was added to simulations of soil development to investigate a well-studied chronosequence of soils near Santa Cruz, CA. The model formulation includes organic acid input, transport, decomposition, organic-metal aqueous complexation and mineral surface complexation in various combinations. Results suggest that although organic acid reactions accelerate mineral dissolution rates near the soil surface, the net response is an overall decrease in chemical weathering. Model results demonstrate the importance of organic acid input concentrations, fluid flow, decomposition and secondary mineral precipitation rates on the evolution of mineral weathering fronts. In particular, model soil profile evolution is sensitive to kaolinite precipitation and oxalate decomposition rates. The soil profile-scale modeling presented here provides insights into the influence of organic carbon cycling on soil weathering and pedogenesis and supports the need for further field-scale measurements of the flux and speciation of reactive organic compounds.

  13. Microbially induced organic acid underdeposit attack in a gas pipeline

    SciTech Connect

    Dias, O.C.; Bromel, M.C. )

    1990-04-01

    A leaking undersea carbon-steel gas pipeline was investigated, and attack was confined to low areas where water had accumulated.Analyses showed that pitting, which occurred under deposits, was caused by organic acids generated by bacteria. The metabolic activities of anaerobic sporeformers produce these acids. Alkyl amine carboxylic acid and metronidizole were effective deterrents at low concentrations.

  14. Factors controlling the abundance of organic sulfur in flash pyrolyzates of Upper Cretaceous kerogens from Sergipe Basin, Brazil

    USGS Publications Warehouse

    Carmo, A.M.; Stankiewicz, B.A.; Mastalerz, Maria; Pratt, L.M.

    1997-01-01

    The molecular and elemental composition of immature kerogens isolated from Upper Cretaceous marine carbonates from Sergipe Basin, Brazil were investigated using combined pyrolysis-gas chromatography/mass spectrometry and organic petrographic techniques. The kerogens are predominantly composed of reddish-fluorescing amorphous organic matter (AOM) and variable amounts of yellow-fluorescing alginite and liptodetrinite. The abundance of organic sulfur in the kerogens inferred from the ratio 2-ethyl-5-methylthiophene/(1,2-dimethylbenzene + dec-1-ene) in the pyrolyzates is variable and may be related to changes in the type of primary organic input and/or to variations in rates of bacterial sulfate reduction. A concomitant increase in S/C and O/C ratios determined in situ using the electron microprobe is observed in AOM and alginites and may be related to a progressive oxidation of the organic matter during sulfurization. The S/C ratio of the AOM is systematically higher than the S C ratio of the alginites. Combined with a thiophene distribution characteristic of pyrolyzates of Type II organic matter, the higher S/C of AOM in Sergipe kerogens suggests that sulfurization and incorporation of low-molecular weight lipids derived from normal marine organic matter into the kerogen structure predominated over direct sulfurization of highly aliphatic algal biomacromolecules.The molecular and elemental composition of immature kerogens isolated from Upper Cretaceous marine carbonates from Sergipe Basin, Brazil were investigated using combined pyrolysis-gas chromatography/mass spectrometry and organic petrographic techniques. The kerogens are predominantly composed of reddish-fluorescing amorphous organic matter (AOM) and variable amounts of yellow-fluorescing alginite and liptodetrinite. The abundance of organic sulfur in the kerogens inferred from the ratio 2-ethyl-5-methylthiophene/(1,2-dimethylbenzene+dec-1-ene) in the pyrolyzates is variable and may be related to changes in

  15. On the source of organic acid aerosol layers above clouds.

    PubMed

    Sorooshian, Armin; Lu, Miao-Ling; Brechtel, Fred J; Jonsson, Haflidi; Feingold, Graham; Flagan, Richard C; Seinfeld, John H

    2007-07-01

    During the July 2005 Marine Stratus/Stratocumulus Experiment (MASE) and the August-September 2006 Gulf of Mexico Atmospheric Composition and Climate Study (GoMACCS), the Center for Interdisciplinary Remotely-Piloted Aircraft Studies (CIRPAS) Twin Otter probed aerosols and cumulus clouds in the eastern Pacific Ocean off the coast of northern California and in southeastern Texas, respectively. An on-board particle-into-liquid sampler (PILS) quantified inorganic and organic acid species with < or = 5-min time resolution. Ubiquitous organic aerosol layers above cloud with enhanced organic acid levels were observed in both locations. The data suggest that aqueous-phase reactions to produce organic acids, mainly oxalic acid, followed by droplet evaporation is a source of elevated organic acid aerosol levels above cloud. Oxalic acid is observed to be produced more efficiently relative to sulfate as the cloud liquid water content increases, corresponding to larger and less acidic droplets. As derived from large eddy simulations of stratocumulus underthe conditions of MASE, both Lagrangian trajectory analysis and diurnal cloudtop evolution provide evidence that a significant fraction of the aerosol mass concentration above cloud can be accounted for by evaporated droplet residual particles. Methanesulfonate data suggest that entrainment of free tropospheric aerosol can also be a source of organic acids above boundary layer clouds.

  16. Weed seed persistence and microbial abundance in long-term organic and conventional cropping systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Weed seed persistence in soil can be influenced by many factors, including crop management. This research was conducted to determine whether organic management systems with higher organic amendments and soil microbial biomass could reduce weed seed persistence compared to conventional management sy...

  17. Occurrence and abundance of carbohydrates and amino compounds in sequentially extracted labile soil organic matter fractions.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study aimed to investigate the content of carbohydrates and amino compounds in three labile fraction of soil organic matter (SOM). Soil samples were collected from two agricultural fields in southern Italy and the light fraction (LF), the 500–53-µm particulate organic matter (POM) and the mobil...

  18. Accounting for non-independent detection when estimating abundance of organisms with a Bayesian approach

    USGS Publications Warehouse

    Martin, Julien; Royle, J. Andrew; MacKenzie, Darryl I.; Edwards, Holly H.; Kery, Marc; Gardner, Beth

    2011-01-01

    Summary 1. Binomial mixture models use repeated count data to estimate abundance. They are becoming increasingly popular because they provide a simple and cost-effective way to account for imperfect detection. However, these models assume that individuals are detected independently of each other. This assumption may often be violated in the field. For instance, manatees (Trichechus manatus latirostris) may surface in turbid water (i.e. become available for detection during aerial surveys) in a correlated manner (i.e. in groups). However, correlated behaviour, affecting the non-independence of individual detections, may also be relevant in other systems (e.g. correlated patterns of singing in birds and amphibians). 2. We extend binomial mixture models to account for correlated behaviour and therefore to account for non-independent detection of individuals. We simulated correlated behaviour using beta-binomial random variables. Our approach can be used to simultaneously estimate abundance, detection probability and a correlation parameter. 3. Fitting binomial mixture models to data that followed a beta-binomial distribution resulted in an overestimation of abundance even for moderate levels of correlation. In contrast, the beta-binomial mixture model performed considerably better in our simulation scenarios. We also present a goodness-of-fit procedure to evaluate the fit of beta-binomial mixture models. 4. We illustrate our approach by fitting both binomial and beta-binomial mixture models to aerial survey data of manatees in Florida. We found that the binomial mixture model did not fit the data, whereas there was no evidence of lack of fit for the beta-binomial mixture model. This example helps illustrate the importance of using simulations and assessing goodness-of-fit when analysing ecological data with N-mixture models. Indeed, both the simulations and the goodness-of-fit procedure highlighted the limitations of the standard binomial mixture model for aerial

  19. Reactive Distillation for Esterification of Bio-based Organic Acids

    SciTech Connect

    Fields, Nathan; Miller, Dennis J.; Asthana, Navinchandra S.; Kolah, Aspi K.; Vu, Dung; Lira, Carl T.

    2008-09-23

    The following is the final report of the three year research program to convert organic acids to their ethyl esters using reactive distillation. This report details the complete technical activities of research completed at Michigan State University for the period of October 1, 2003 to September 30, 2006, covering both reactive distillation research and development and the underlying thermodynamic and kinetic data required for successful and rigorous design of reactive distillation esterification processes. Specifically, this project has led to the development of economical, technically viable processes for ethyl lactate, triethyl citrate and diethyl succinate production, and on a larger scale has added to the overall body of knowledge on applying fermentation based organic acids as platform chemicals in the emerging biorefinery. Organic acid esters constitute an attractive class of biorenewable chemicals that are made from corn or other renewable biomass carbohydrate feedstocks and replace analogous petroleum-based compounds, thus lessening U.S. dependence on foreign petroleum and enhancing overall biorefinery viability through production of value-added chemicals in parallel with biofuels production. Further, many of these ester products are candidates for fuel (particularly biodiesel) components, and thus will serve dual roles as both industrial chemicals and fuel enhancers in the emerging bioeconomy. The technical report from MSU is organized around the ethyl esters of four important biorenewables-based acids: lactic acid, citric acid, succinic acid, and propionic acid. Literature background on esterification and reactive distillation has been provided in Section One. Work on lactic acid is covered in Sections Two through Five, citric acid esterification in Sections Six and Seven, succinic acid in Section Eight, and propionic acid in Section Nine. Section Ten covers modeling of ester and organic acid vapor pressure properties using the SPEAD (Step Potential

  20. The acid tolerance response of Salmonella typhimurium provides protection against organic acids.

    PubMed

    Baik, H S; Bearson, S; Dunbar, S; Foster, J W

    1996-11-01

    Salmonella typhimurium encounters a variety of acid stress situations during pathogenesis and in the natural environment. These include the extreme low pH encountered in the stomach and a less acidic intestinal environment containing large amounts of organic weak acids (volatile fatty acids). The acid tolerance response (ATR) is a complex defence system that can minimize the lethal effects of extreme low pH (pH3). The data presented illustrate that the ATR can also defend against weak acids such as butyric, acetic or propionic acids. Although an acid shock of pH 4.4 induced the ATR, growth in subinhibitory concentrations of weak acids did not. Various mutations shown to affect tolerance to extreme acid conditions (pH 3) were tested for their effects on tolerance to weak acids. An rpoS mutant lacking the alternative sigma factor sigma s failed to protect cells against weak acids as well as extreme acid pH. The fur (ferric uptake regulator) and atp (Mg(2+)-dependent ATPase) mutants defective in extreme acid tolerance showed no defects in their tolerance to weak acids. Curiously, the atbR mutant that exhibits increased tolerance to extreme acid pH proved sensitive to weak acids. Several insertions that rendered cells sensitive to organic acids were isolated, all of which proved to be linked to the rpoS locus.

  1. Soil compaction and organic matter affect conifer seedling nonmycorrhizal and ectomycorrhizal root tip abundance and diversity. Forest Service research paper

    SciTech Connect

    Amaranthus, M.P.; Page-Dumroese, D.; Harvey, A.; Cazares, E.; Bednar, L.F.

    1996-05-01

    Three levels of organic matter removal (bole only; bole and crowns; and bole, crowns, and forest floor) and three levels of mechanical soil compaction (no compaction, moderate compaction, and severe soil compaction) were studied as they influence Douglas-fir (Pseudotsuga menziesii var. glauca (Beissn.) Franco) and western white pine (Pinus monticola Dougl. ex D. Don) seedlings following outplanting. Moderate and severe soil compaction significantly reduced nonmycorrhizal root tip abundance on both Douglas-fir and western white pine seedlings (p less than or equal to 0.05). Ectomycorrhizal root tip abundance was significantly reduced on Douglas-fir seedlings in severely compacted areas with bole and crowns and bole, crowns, and forest floor removed. Ectomycorrhizal diversity also was significantly reduced on Douglas-fir seedlings in all severely compacted areas.

  2. Recombinant microorganisms for increased production of organic acids

    DOEpatents

    Yi, Jian; Kleff, Susanne; Guettler, Michael V

    2013-04-30

    Disclosed are recombinant microorganisms for producing organic acids. The recombinant microorganisms express a polypeptide that has the enzymatic activity of an enzyme that is utilized in the pentose phosphate cycle. The recombinant microorganism may include recombinant Actinobacillus succinogenes that has been transformed to express a Zwischenferment (Zwf) gene. The recombinant microorganisms may be useful in fermentation processes for producing organic acids such as succinic acid and lactic acid. Also disclosed are novel plasmids that are useful for transforming microorganisms to produce recombinant microorganisms that express enzymes such as Zwf.

  3. Recombinant microorganisms for increased production of organic acids

    DOEpatents

    Yi, Jian [East Lansing, MI; Kleff, Susanne [East Lansing, MI; Guettler, Michael V [Holt, MI

    2012-02-21

    Disclosed are recombinant microorganisms for producing organic acids. The recombinant microorganisms express a polypeptide that has the enzymatic activity of an enzyme that is utilized in the pentose phosphate cycle. The recombinant microorganism may include recombinant Actinobacillus succinogenes that has been transformed to express a Zwischenferment (Zwf) gene. The recombinant microorganisms may be useful in fermentation processes for producing organic acids such as succinic acid and lactic acid. Also disclosed are novel plasmids that are useful for transforming microorganisms to produce recombinant microorganisms that express enzymes such as Zwf.

  4. Organic layer serves as a hotspot of microbial activity and abundance in Arctic tundra soils.

    PubMed

    Lee, Seung-Hoon; Jang, Inyoung; Chae, Namyi; Choi, Taejin; Kang, Hojeong

    2013-02-01

    Tundra ecosystem is of importance for its high accumulation of organic carbon and vulnerability to future climate change. Microorganisms play a key role in carbon dynamics of the tundra ecosystem by mineralizing organic carbon. We assessed both ecosystem process rates and community structure of Bacteria, Archaea, and Fungi in different soil layers (surface organic layer and subsurface mineral soil) in an Arctic soil ecosystem located at Spitsbergen, Svalbard during the summer of 2008 by using biochemical and molecular analyses, such as enzymatic assay, terminal restriction fragment length polymorphism (T-RFLP), quantitative polymerase chain reaction (qPCR), and pyrosequencing. Activity of hydrolytic enzymes showed difference according to soil type. For all three microbial communities, the average gene copy number did not significantly differ between soil types. However, archaeal diversities appeared to differ according to soil type, whereas bacterial and fungal diversity indices did not show any variation. Correlation analysis between biogeochemical and microbial parameters exhibited a discriminating pattern according to microbial or soil types. Analysis of the microbial community structure showed that bacterial and archaeal communities have different profiles with unique phylotypes in terms of soil types. Water content and hydrolytic enzymes were found to be related with the structure of bacterial and archaeal communities, whereas soil organic matter (SOM) and total organic carbon (TOC) were related with bacterial communities. The overall results of this study indicate that microbial enzyme activity were generally higher in the organic layer than in mineral soils and that bacterial and archaeal communities differed between the organic layer and mineral soils in the Arctic region. Compared to mineral soil, peat-covered organic layer may represent a hotspot for secondary productivity and nutrient cycling in this ecosystem.

  5. [Use of organic acids in acne and skin discolorations therapy].

    PubMed

    Kapuścińska, Alicja; Nowak, Izabela

    2015-03-22

    Acne is one of the most frequent skin disorders that occurs in puberty, but often adults also have acne. The most important factors responsible for acne are elevated production of sebum by hyperactive sebaceous glands and blockage of the follicle because of hyperkeratosis [14]. The third etiopathogenic factor of acne is excessive microflora reproduction [8]. The most significant bacterium that is responsible for formation of skin lesions is Propionibacterium acnes, a rod-shaped Gram-positive and aerotolerant anaerobic bacterium. It is estimated that P. acnes is responsible for acne in approximately 80% of people aged 11 to 30 [27,40]. Even healed skin lesions can often cause skin discolorations and scar formation [51]. Exfoliating chemical substances that are commonly used in dermatology and cosmetology are organic acids. Exfoliating treatment using organic acids is called "chemical peeling" and consists of controlled application of those substances on the skin [38]. The depth of exfoliation depends on organic acid concentration, type of substance and contact time with the skin [41]. Using exfoliating agents seems to be helpful in excessive keratinization - one of several factors responsible for acne. Moreover, epidermis exfoliation is a popular method of removing skin discoloration [22]. Considering chemical structure, exfoliating substances that are most often used in cosmetology contain alpha-hydroxyacids (glycolic acid, lactic acid, mandelic acid and citric acid), beta-hydroxyacids (salicylic acid) and other organic acids, such as trichloroacetic acid and pyruvic acid [47]. In this article, a literature review of use of organic acids in acne and skin discoloration therapy is presented.

  6. Selective removal of phosphate for analysis of organic acids in complex samples.

    PubMed

    Deshmukh, Sandeep; Frolov, Andrej; Marcillo, Andrea; Birkemeyer, Claudia

    2015-04-03

    Accurate quantitation of compounds in samples of biological origin is often hampered by matrix interferences one of which occurs in GC-MS analysis from the presence of highly abundant phosphate. Consequently, high concentrations of phosphate need to be removed before sample analysis. Within this context, we screened 17 anion exchange solid-phase extraction (SPE) materials for selective phosphate removal using different protocols to meet the challenge of simultaneous recovery of six common organic acids in aqueous samples prior to derivatization for GC-MS analysis. Up to 75% recovery was achieved for the most organic acids, only the low pKa tartaric and citric acids were badly recovered. Compared to the traditional approach of phosphate removal by precipitation, SPE had a broader compatibility with common detection methods and performed more selectively among the organic acids under investigation. Based on the results of this study, it is recommended that phosphate removal strategies during the analysis of biologically relevant small molecular weight organic acids consider the respective pKa of the anticipated analytes and the detection method of choice.

  7. Survey of organic acid eluents for anion chromatography

    SciTech Connect

    Book, D.E.

    1981-10-01

    Of all the potential eluents surveyed (including aromatic, sulfonic, phosphonic, among other acids), only the carboxylic acids and the nitrophenols are recommended as eluents for anion chromatography. The concentration of the eluent should be in the range 5 x 10/sup -5/ to 1 x 10/sup -3/ M. The eluent should have the same charge as inorganic anions, a higher charge than organic acid samples. Choice of eluents for separation of halides, chloride and sulfate, multivalent inorganic anions, small alkyl acids, and aromatic acids is discussed. (DLC)

  8. Determination of organic acids by CE and CEC methods.

    PubMed

    Klampfl, Christian W

    2007-10-01

    A comprehensive overview of the analysis of low-molecular-mass organic acids employing electromigration methods in the capillary format is given. This review includes papers published since 2003 and can be seen as an update of the review paper published by Galli et al. in 2003. Tables included in this review contain application papers describing the determination of organic acids from a variety of fields like the analysis of food and beverages, environmental samples, samples from clinical origin, and from natural products.

  9. Association Mapping of Main Tomato Fruit Sugars and Organic Acids

    PubMed Central

    Zhao, Jiantao; Xu, Yao; Ding, Qin; Huang, Xinli; Zhang, Yating; Zou, Zhirong; Li, Mingjun; Cui, Lu; Zhang, Jing

    2016-01-01

    Association mapping has been widely used to map the significant associated loci responsible for natural variation in complex traits and are valuable for crop improvement. Sugars and organic acids are the most important metabolites in tomato fruits. We used a collection of 174 tomato accessions composed of Solanum lycopersicum (123 accessions) and S. lycopersicum var cerasiforme (51 accessions) to detect significantly associated loci controlling the variation of main sugars and organic acids. The accessions were genotyped with 182 SSRs spreading over the tomato genome. Association mapping was conducted on the main sugars and organic acids detected by gas chromatography-mass spectrometer (GC-MS) over 2 years using the mixed linear model (MLM). We detected a total of 58 significantly associated loci (P < 0.001) for the 17 sugars and organic acids, including fructose, glucose, sucrose, citric acid, malic acid. These results not only co-localized with several reported QTLs, including fru9.1/PV, suc9.1/PV, ca2.1/HS, ca3.1/PV, ca4.1/PV, and ca8.1/PV, but also provided a list of candidate significantly associated loci to be functionally validated. These significantly associated loci could be used for deciphering the genetic architecture of tomato fruit sugars and organic acids and for tomato quality breeding. PMID:27617019

  10. Metabolic evolution of Escherichia coli strains that produce organic acids

    DOEpatents

    Grabar, Tammy; Gong, Wei; Yocum, R Rogers

    2014-10-28

    This invention relates to the metabolic evolution of a microbial organism previously optimized for producing an organic acid in commercially significant quantities under fermentative conditions using a hexose sugar as sole source of carbon in a minimal mineral medium. As a result of this metabolic evolution, the microbial organism acquires the ability to use pentose sugars derived from cellulosic materials for its growth while retaining the original growth kinetics, the rate of organic acid production and the ability to use hexose sugars as a source of carbon. This invention also discloses the genetic change in the microorganism that confers the ability to use both the hexose and pentose sugars simultaneously in the production of commercially significant quantities of organic acids.

  11. EFFECT OF ACIDITY ON SECONDARY ORGANIC AEROSOL FORMATION FROM ISOPRENE

    EPA Science Inventory

    The effect of particle-phase acidity on secondary organic aerosol (SOA) formation from isoprene is investigated in a laboratory chamber study, in which the acidity of the inorganic seed aerosol was controlled systematically. The observed enhancement in SOA mass concentration is c...

  12. Organic geochemistry of amino acids: Precambrian to recent

    SciTech Connect

    Engel, M.H.; Macko, S.A.

    1985-01-01

    Since the discovery of amino acids in fossils (Abelson, 1954), considerable effort has been made to elucidate the origin and distribution of amino acids in geologic materials. Racemization and decomposition reactions of amino acids and peptides derived via the natural hydrolysis of protein constituents of organisms have been extensively studied. While the ubiquity of amino acids presents a challenge for discerning their indigeneity in geologic samples, careful analyses have resulted in successful applications of amino acid racemization and decomposition reactions for investigations of geochronologic, paleoclimatic, stratigraphic, diagenetic and chemotaxonomic problems for Quaternary age samples. An investigation of amino acids in sediments from Baffin Island fjords indicates that their distribution may also provide data with respect to the relative contributions of marine and terrigenous organic matter to recent sediments. While the absence of unstable amino acids and the presence of racemic amino acids in a sample may preclude very recent contamination, the possibility of retardation of amino acid racemization rates subsequent to geopolymer formation must also be considered. Studies of amino acids in Paleozoic, Mesozoic and early Cenozoic age samples are limited. Precambrian samples, however, have received much attention, given the potential (however slight) for isolating compounds representative of the earliest living systems. A future approach for elucidating the origin(s) of amino acids in ancient samples may be analyses of their individual stable isotopic compositions.

  13. Reactions Between Water Soluble Organic Acids and Nitrates in Atmospheric Aerosols: Recycling of Nitric Acid and Formation of Organic Salts

    SciTech Connect

    Wang, Bingbing; Laskin, Alexander

    2014-03-25

    Atmospheric particles often include a complex mixture of nitrate and secondary organic materials accumulated within the same individual particles. Nitrate as an important inorganic component can be chemically formed in the atmosphere. For instance, formation of sodium nitrate (NaNO3) and calcium nitrate Ca(NO3)2 when nitrogen oxide and nitric acid (HNO3) species react with sea salt and calcite, respectively. Organic acids contribute a significant fraction of photochemically formed secondary organics that can condense on the preexisting nitrate-containing particles. Here, we present a systematic microanalysis study on chemical composition of laboratory generated particles composed of water soluble organic acids and nitrates (i.e. NaNO3 and Ca(NO3)2) investigated using computer controlled scanning electron microscopy with energy dispersive analysis of X-rays (CCSEM/EDX) and Fourier transform infrared micro-spectroscopy (micro-FTIR). The results show that water-soluble organic acids can react with nitrates releasing gaseous HNO3 during dehydration process. These reactions are attributed to acid displacement of nitrate with weak organic acids driven by the evaporation of HNO3 into gas phase due to its relatively high volatility. The reactions result in significant nitrate depletion and formation of organic salts in mixed organic acids/nitrate particles that in turn may affect their physical and chemical properties relevant to atmospheric environment and climate. Airborne nitrate concentrations are estimated by thermodynamic calculations corresponding to various nitrate depletions in selected organic acids of atmospheric relevance. The results indicate a potential mechanism of HNO3 recycling, which may further affect concentrations of gas- and aerosol-phase species in the atmosphere and the heterogeneous reaction chemistry between them.

  14. Interaction of Humic Acids with Organic Toxicants

    NASA Astrophysics Data System (ADS)

    Tchaikovskaya, O. N.; Yudina, N. V.; Maltseva, E. V.; Nechaev, L. V.; Svetlichnyi, V. A.

    2016-08-01

    Interaction of humic acids with polyaromatic hydrocarbons (PAH) (naphthalene and anthracene) and triazole series fungicides (cyproconazole (CC) and tebuconazole (TC)) is investigated by the method of fluorescence quenching depending on the concentration of substances in solutions and their structural features. Humic acids were modified by mechanochemical activation in a planetary mill. The complex character of intermolecular interactions between PAH and fungicides with humic acids, including donor-acceptor and hydrophobic binding, is established. Thermodynamically stable conformations of biocide molecules were estimated using ChemOffice CS Chem3D 8.0 by methods of molecular mechanics (MM2) and molecular dynamics. Biocide molecules with pH 7 are in energetically favorable position when the benzene and triazole rings are almost parallel to each other. After acidification of solutions to pH 4.5, the CC molecule retains the geometry for which donor-acceptor interactions are possible: the benzene ring in the molecule represents the electron donor, and triazole is the acceptor. In this case, the electron density in CC is redistributed easier, which is explained by a smaller number of carbon atoms between the triazole and benzene rings, unlike TC. As a result, the TC triazole ring is protonated to a greater degree, acquiring a positive charge, and enters into donoracceptor interactions with humic acid (HA) samples. The above-indicated bond types allow HA to participate actively in sorption processes and to provide their interaction with biocides and PAH and hence, to act as detoxifying agents for recultivation of the polluted environment.

  15. Molybdenum phosphosulfide: an active, acid-stable, earth-abundant catalyst for the hydrogen evolution reaction.

    PubMed

    Kibsgaard, Jakob; Jaramillo, Thomas F

    2014-12-22

    Introducing sulfur into the surface of molybdenum phosphide (MoP) produces a molybdenum phosphosulfide (MoP|S) catalyst with superb activity and stability for the hydrogen evolution reaction (HER) in acidic environments. The MoP|S catalyst reported herein exhibits one of the highest HER activities of any non-noble-metal electrocatalyst investigated in strong acid, while remaining perfectly stable in accelerated durability testing. Whereas mixed-metal alloy catalysts are well-known, MoP|S represents a more uncommon mixed-anion catalyst where synergistic effects between sulfur and phosphorus produce a high-surface-area electrode that is more active than those based on either the pure sulfide or the pure phosphide. The extraordinarily high activity and stability of this catalyst open up avenues to replace platinum in technologies relevant to renewable energies, such as proton exchange membrane (PEM) electrolyzers and solar photoelectrochemical (PEC) water-splitting cells.

  16. [Inhibition of growth of microscopic fungi with organic acids].

    PubMed

    Conková, E; Para, L; Kocisová, A

    1993-01-01

    Fungicidal effects of five selected organic acids (lactic, acetic, formic, oxalic, and propionic) in concentrations 3, 5, 10, 20 and 50 ml/l on nine selected species of moulds were tested. Lactic and oxalic acids did not prove the satisfactory fungicidal activity in any of the chosen concentrations. The antifungal effect of the other three acids, manifested by the growth inhibition of the tested moulds is shown in Tab. I and it can be expressed by sequence: propionic acid, formic acid, and acetic acid. These acids also had effects only in concentrations 20 ml/l and 50 ml/l. Propionic acid in concentration 20 ml/l inhibited the growth of five moulds (Penicillium glabrum, Aspergillus niger, Fusarium moniliforme, Aspergillus fumigatus, Cladosporium sphaerospermum). In testing of concentration 50 ml/l, the lower fungicidal ability was ascertained only in growth suppression of Aspergillus flavus. The fungicidal activity of formic acid was registered in concentration 20 ml/l in two cases and in concentration 50 ml/l in six cases. Acetic acid inhibited the growth in concentration 50 ml/l only in two cases. Tab. II shows the percentual evaluation of propionic acid and formic acid with regard to their inhibition abilities. The fungicidal efficiency of propionic acid resulting from the experiment is 88.9%.

  17. Can heavy isotopes increase lifespan? Studies of relative abundance in various organisms reveal chemical perspectives on aging

    PubMed Central

    2016-01-01

    Stable heavy isotopes co‐exist with their lighter counterparts in all elements commonly found in biology. These heavy isotopes represent a low natural abundance in isotopic composition but impose great retardation effects in chemical reactions because of kinetic isotopic effects (KIEs). Previous isotope analyses have recorded pervasive enrichment or depletion of heavy isotopes in various organisms, strongly supporting the capability of biological systems to distinguish different isotopes. This capability has recently been found to lead to general decline of heavy isotopes in metabolites during yeast aging. Conversely, supplementing heavy isotopes in growth medium promotes longevity. Whether this observation prevails in other organisms is not known, but it potentially bears promise in promoting human longevity. PMID:27554342

  18. Organic acids as indicators of VOC oxidation: Measurements of formic acid and other gas-phase acids during SOAS

    NASA Astrophysics Data System (ADS)

    Farmer, D.; Brophy, P.; Murschell, T.

    2013-12-01

    Oxidation of volatile organic compounds (VOCs) in the atmosphere affects not only the oxidative capacity of the atmosphere, but also the formation of secondary organic aerosol. Organic acids are produced during VOC oxidation, although additional sources include biomass burning and primary emissions. While some organic acids are semi-volatile and dominantly present in the aerosol phase, formic acid and other small organic acids are dominantly present in the gas phase. The concentrations of these gas-phase organic acids can provide insight into oxidation chemistry. Here, we present measurements made during the Southern Oxidant and Aerosol Study (SOAS) in Centerville, Alabama during the summer of 2013 by a high resolution time-of-flight chemical ionization mass spectrometer (HR-TOF-CIMS) operated in a novel switching reagent ion mode to measure gas phase organic acids with both acetate (CH3COO-) and iodide (I-) reagent ions. Formic acid was quantified using for both ionization schemes using multiple calibration techniques. In this study, we will focus on the impact of anthropogenic pollutants, including nitrogen and sulfur oxides, on oxidation chemistry, and discuss the potential use of organic acids as tracers for atmospheric oxidation chemistry.

  19. Organic Acids Over Equatorial Africa: Results from DECAFE 88

    NASA Astrophysics Data System (ADS)

    Helas, Günter; Bingemer, Heinz; Andreae, Meinrat O.

    1992-04-01

    Gaseous short chain organic acids were measured during the dry season (February) in and above the rain forest of the northern Congo. Samples were taken at ground level and during several flights up to 4 km altitude. The organic acids were concentrated from the atmosphere by using "mist scrubbers," which expose a mist of deionized water to the air to be probed. The organic acids absorbed in the water were subsequently analyzed by ion chromatography. Formic, acetic, and pyruvic acids were identified in the samples. At ground level, average mixing ratios of gaseous formic and acetic acid of 0.5±0.6 and 0.6±0.7 parts per billion by volume (ppbv) (1 s), respectively, were found. Boundary layer mixing ratios, however, were significantly higher (3.7±1.0 and 2.7±0.9 ppbv). This indicates a downward net flux of these atmospheric trace components from the boundary layer to the surface. Free tropospheric samples taken above the cloud convection layer show lower mixing ratios again (0.9±0.3 and 0.7±0.1 ppbv). On the basis of this vertical distribution, direct emission by vegetation is not considered to be the dominant source. Biomass burning and photochemical oxidation of biogenic precursors are the major processes contributing to the enhancement of organic acids observed in the boundary layer. The organic acids parallel the profiles of ozone and CO, which suggests that their generation processes are closely related. Pyruvic acid is not correlated with formic acid, indicating that the oxidation of isoprene is not of major importance. In emissions from biomass fires, CO correlates well with formic and acetic acid, and thus some of the enhancement of organic acids in the boundary layer can be explained due to burning. However, an additional gas phase source for organic acids must exist to explain the observed ratio of formic to acetic acid. This is most likely the ozonolysis of olefins which were released as pyrolysis products from biomass burning.

  20. c-Myc Programs Fatty Acid Metabolism and Dictates Acetyl-CoA Abundance and Fate*

    PubMed Central

    Edmunds, Lia R.; Sharma, Lokendra; Kang, Audry; Lu, Jie; Vockley, Jerry; Basu, Shrabani; Uppala, Radha; Goetzman, Eric S.; Beck, Megan E.; Scott, Donald; Prochownik, Edward V.

    2014-01-01

    myc−/− rat fibroblasts (KO cells) differ from myc+/+ (WT) cells and KO cells with enforced Myc re-expression (KO-Myc cells) with respect to mitochondrial structure and function, utilization of glucose and glutamine as energy-generating substrates, and ATP levels. Specifically, KO cells demonstrate low levels of glycolysis and oxidative phosphorylation, dysfunctional mitochondria and electron transport chain complexes, and depleted ATP stores. We examined here how these cells adapt to their energy-deficient state and how they differ in their uptake and utilization of long- and medium-chain fatty acids such as palmitate and octanoate, respectively. Metabolic tracing of these molecules showed that KO cells preferentially utilize them as β-oxidation substrates and that, rather than directing them into phospholipids, preferentially store them as neutral lipids. KO cell transcriptional profiling and functional assays revealed a generalized up-regulation of pathways involved in fatty acid transport and catabolism as well as evidence that these cells attempt to direct acetyl-CoA into the tricarboxylic acid (TCA) cycle for ATP production rather than utilizing it for anabolic purposes. Additional evidence to support this idea included the finding that AMP-dependent protein kinase was constitutively activated in KO cells. The complex control of pyruvate dehydrogenase, which links glycolysis to the TCA cycle, was also maximized to ensure the conversion of pyruvate to acetyl-CoA. Despite these efforts to maximize acetyl-CoA for energy-generating purposes, its levels remained chronically low in KO cells. This suggests that tumor cells with Myc deregulation might be susceptible to novel therapies that limit acetyl-CoA availability. PMID:25053415

  1. Clinical applications of urinary organic acids. Part 2. Dysbiosis markers.

    PubMed

    Lord, Richard S; Bralley, J Alexander

    2008-12-01

    Part 1 of this series focused on urinary organic acids as markers of detoxification; part 2 focuses on dysbiosis markers. Intestinal microbial growth is accompanied by the release of products of their metabolism that may be absorbed and excreted in urine. Several organic acids are known to be specific products of bacterial metabolic action on dietary polyphenols or unassimilated amino acids or carbohydrates. Associated gastrointestinal or neurological symptoms may result from irritation of the intestinal mucosa or systemic distribution of absorbed neurotoxic products. Detection of abnormally elevated levels of these products is a useful diagnostic tool for patients with gastrointestinal or toxicological symptoms. Test profiles of urinary organic acids associated with microbial overgrowth can include benzoate, hippurate, phenylacetate, phenylpropionate, cresol, hydroxybenzoate, hydroxyphenylacetate, hydroxyphenylpropionate and 3,4-dihydroxyphenylpropionate, indican, tricarballylate, D-lactate, and D-arabinitol. Effective treatments for the associated microbial overgrowths may be directed at reducing microbial populations, introducing favorable microbes, and restoring intestinal mucosal integrity.

  2. Abundance and diversity of total and nitrifying prokaryotes as influenced by biochemical quality of organic inputs combined with mineral nitrogen

    NASA Astrophysics Data System (ADS)

    Muema, Esther; Vanlauwe, Bernard; Röhl, Carolin; Cadisch, Georg; Rasche, Frank

    2014-05-01

    Ammonia-oxidizing bacteria and archaea (AOB, AOA) co-exist in soil, but they respond differently to distinct fertilization strategies in agricultural soils. Accordingly, effects of organic inputs and combination with mineral nitrogen (N) on AOB and AOA remain poorly understood. The aim of this study was to compare soil amendment with contrasting quality of organic inputs (i.e., high quality Tithonia diversifolia (TD; C/N ratio: 13, Lignin: 8.9 %; Polyphenols: 1.7 %), intermediate quality Calliandra calothyrsus (CC; 13; 13; 9.4) and low quality Zea mays (ZM; 59; 5.4; 1.2)), and combination with mineral N on the abundance (i.e., DNA-based gene quantification) and community structure (i.e., T-RFLP analysis) of total bacterial and archaea (16S rRNA gene), as well as AOB and AOA (targeting the amoA gene) communities in a Humic Nitisol. Soils (0-15 cm depth) were sampled prior to the onset of the rainy season in March 2012 in a 10 years old field experiment established in the central highlands of Kenya in 2002. Since the start of the experiment, organic inputs were applied annually at a rate of 4 Mg C ha-1 and mineral N twice a year as calcium ammonium nitrate (5Ca(NO3)2NH4NO3) at a rate of 120 kg N ha-1 growing season-1. Quality of organic inputs posed only a significant effect on the AOB community structure between TD versus ZM and CC versus ZM. Moreover, TD significantly increased the size of AOB over ZM input, while higher abundances for total bacteria, total archaea and AOA were measured in ZM and TD over CC. This was explained by high and available N in TD, but low lignin and polyphenol contents in TD and ZM as opposed to CC. AOB responded sensitively (i.e., complete community structure separation) to mineral N, specifically when combined with low quality ZM. Hence, AOB community was specifically responsive to quality of organic inputs and combination of low organic input with mineral N over AOA and total prokaryotic communities in the studied soil. The results

  3. Abundance and Characterization of Dissolved Organic Carbon in Suburban Streams of Baltimore, Maryland, USA

    NASA Astrophysics Data System (ADS)

    Mora, G.; Fazekas, M.

    2014-12-01

    The contribution of streams and rivers to the carbon cycle is significant, transporting to the oceans ~1.4 Pg C/yr, with dissolved carbon corresponding to as much as 0.7 Pg C/yr. Changes in land use have the potential effect of modifying this flux, particularly in urban areas where impervious areas are common. To investigate the effect of urbanization on riverine carbon transport, we studied four first-order streams in Towson, a suburb of Baltimore, Maryland, USA. The watersheds from the studied streams exhibit different levels of urbanization as measured by the percentage of impervious areas. Samples from these four streams were taken weekly, and several chemical constituents were measured either in the field or in the laboratory. These constituents included nitrate, dissolved organic nitrogen, pH, dissolved organic carbon (DOC), total carbon, dissolved inorganic carbon (DIC), phosphate, the carbon isotopic compositions of DOC and DIC, and fluorescence intensity of the DOC. Results show that DOC concentrations were consistently below 5 mg C/L regardless of the level of imperviousness of the watershed. Similarly, carbon isotope ratios were consistent across the studied streams, with values centered around -26.4 per mil, thus suggesting a significant influx of soil-derived organic carbon originated from C3 plants that are common in the watersheds. Confirming this interpretation, fluorescence spectroscopy data suggest a humic-like origin for the DOC of the streams, thus pointing to the heterotrophic nature of the streams. The combined results suggest that the studied streams exhibit similar DOC concentrations, carbon isotopic values, and fluorescence spectra, despite their level of impervious surfaces in their watersheds.

  4. Abundance of organic compounds photochemically produced in the atmospheres of the Outer Planets

    NASA Technical Reports Server (NTRS)

    Raulin, F.; Bossard, A.; Toupance, G.; Ponnamperuma, C.

    1979-01-01

    Organic photochemical syntheses in the Jovian atmosphere was simulated by irradiating, at 147 nm, gaseous mixtures of methane and ammonia with varying amounts of hydrogen. Some results relevant to the photochemistry of the Jupiter atmosphere at several tens of kilometers above the clouds were obtained: (1) a favorable effect of the pressure of high amounts of H2 on the yield of hydrocarbon synthesis when NH3 is mixed with CH4; (2) a very low yield of synthesis of unsaturated hydrocarbons in such conditions; and (3) the possibility of formation of detectable amounts of HCN and CH3CN.

  5. The highly abundant urinary metabolite urobilin interferes with the bicinchoninic acid assay.

    PubMed

    Sampson, D L; Chng, Y L; Upton, Z; Hurst, C P; Parker, A W; Parker, T J

    2013-11-01

    Estimation of total protein concentration is an essential step in any protein- or peptide-centric analysis pipeline. This study demonstrates that urobilin, a breakdown product of heme and a major constituent of urine, interferes considerably with the bicinchoninic acid (BCA) assay. This interference is probably due to the propensity of urobilin to reduce cupric ions (Cu(2+)) to cuprous ions (Cu(1+)), thus mimicking the reduction of copper by proteins, which the assay was designed to do. In addition, it is demonstrated that the Bradford assay is more resistant to the influence of urobilin and other small molecules. As such, urobilin has a strong confounding effect on the estimate of total protein concentrations obtained by BCA assay and thus this assay should not be used for urinary protein quantification. It is recommended that the Bradford assay be used instead.

  6. Effect of flagellates on free-living bacterial abundance in an organically contaminated aquifer

    USGS Publications Warehouse

    Kinner, N.E.; Harvey, R.W.; Kazmierkiewicz-Tabaka, M.

    1997-01-01

    Little is known about the role of protists in the saturated subsurface. Porous media microcosms containing bacteria and protists, were used to determine whether flagellates from an organically contaminated aquifer could substantively affect the number of free- living bacteria (FLB). When flagellates were present, the 3-40% maximum breakthrough of fluorescent y labelled FLB injected into the microcosms was much lower than the 60-130% observed for killed controls Grazing and clearance rates (3-27 FLB flag-1 h-1 and 12-23 nI flag-1 h-1, respectively) calculated from the data were in the range reported for flagellates in other aqueous environments. The data provide evidence that flagellate bacterivory is an important control on groundwater FLB populations.

  7. [Effects of low molecular weight organic acids on speciation of exogenous Cu in an acid soil].

    PubMed

    Huang, Guo-Yong; Fu, Qing-Ling; Zhu, Jun; Wan, Tian-Ying; Hu, Hong-Qing

    2014-08-01

    In order to ascertain the effect of LMWOA (citric acid, tartaric acid, oxalic acid) on Cu-contaminated soils and to investigate the change of Cu species, a red soil derived from quartz sandstone deposit was added by Cu (copper) in the form of CuSO4 x 5H2O so as to simulate soil Cu pollution, keeping the additional Cu concentrations were 0, 100, 200, 400 mg x kg(-1) respectively. After 9 months, different LMWOA was also added into the simulated soil, keeping the additional LMWOAs in soil were 0, 5, 10, 20 mmol x kg(-1) respectively. After 2 weeks incubation, the modified sequential extraction method on BCR (European Communities Bureau of Reference) was used to evaluate the effects of these LMWOAs on the changes of copper forms in soil. The result showed that the percentage of weak acid dissolved Cu, the most effective form in the soil increased with three organic acids increase in quantity in the simulated polluted soil. And there was a good activation effect on Cu in the soil when organic acid added. Activation effects on Cu increased with concentration of citric acid increasing, but it showed a rise trend before they are basically remained unchanged in the case of tartaric acid and oxalic acid added in the soil. On the contrary, the state of the reduction of copper which was regarded as a complement for effective state decreased with the increased concentration of organic acid in the soil, especially with citric acid. When 20 mmol x kg(-1) oxalic acid and citric acid were added into the soil, the activation effect was the best; whereas for tartaric, the concentration was 10 mmol x kg(-1). In general, the effect on the changes of Cu forms in the soil is citric acid > tartaric acid > oxalic acid.

  8. Ontogenetic change in the abundance of mycosporine-like amino acids in non-zooxanthellate coral larvae

    NASA Astrophysics Data System (ADS)

    Yakovleva, Irina M.; Baird, Andrew H.

    2005-11-01

    Although mycosporine-like amino acids (MAAs) have been extensively investigated in reef-building corals, the sources of these MAAs and the process of their interconversion remain a topic of interest. Here we examined ontogenetic change in the abundance of MAAs in planula larvae of the spawning scleractinian coral Goniastrea retiformis in the absence of zooxanthellae and other dietary input. In order to examine the potential contribution of prokaryotes in the synthesis of MAAs in animal tissue, one group of larvae were treated with the antibiotic rifampicin. High concentrations of MAAs (mycosporine-glycine, shinorine, palythinol, asterina-330), were present in the asymbiotic eggs and adults; however, no MAAs were present in the endosymbiotic zooxanthellae. We documented a steady decline in the total MAA concentrations through time in larvae treated with rifampicin; however, in the absence of antibiotic there was a significant increase in the concentration of MAAs, driven by a sharp increase in the abundance of shinorine and palythinol between day 3 and 7. Our results suggest that MAA synthesis and conversion in G. retiformis larvae occurred in the absence of symbiotic zooxanthellae, and indicate a possible contribution of prokaryotes associated with the animal tissue to these processes.

  9. Surface complexation modeling or organic acid sorption to goethite

    SciTech Connect

    Evanko, C.R.; Dzombak, D.A.

    1999-06-15

    Surface complexation modeling was performed using the Generalized Two-Layer Model for a series of low molecular weight organic acids. Sorption of these organic acids to goethite was investigated in a previous study to assess the influence of particular structural features on sorption. Here, the ability to describe the observed sorption behavior for compounds with similar structural features using surface complexation modeling was investigated. A set of surface reactions and equilibrium constants yielding optimal data fits was obtained for each organic acid over a range of total sorbate concentrations. Surface complexation modeling successfully described sorption of a number of the simple organic acids, but an additional hydrophobic component was needed to describe sorption behavior of some compounds with significant hydrophobic character. These compounds exhibited sorption behavior of some compounds with significant hydrophobic character. These compounds exhibited sorption behavior that was inconsistent with ligand exchange mechanisms since sorption behavior of some compounds with significant hydrophobic character. These compounds exhibited sorption behavior that was inconsistent with ligand exchange mechanisms since sorption did not decrease with increasing total sorbate concentration and/or exceeded surface site saturation. Hydrophobic interactions appeared to be most significant for the compound containing a 5-carbon aliphatic chain. Comparison of optimized equilibrium constants for similar surface species showed that model results were consistent with observed sorption behavior: equilibrium constants were highest for compounds having adjacent carboxylic groups, lower for compounds with adjacent phenolic groups, and lowest for compounds with phenolic groups in the ortho position relative to a carboxylic group. Surface complexation modeling was also performed to fit sorption data for Suwannee River fulvic acid. The data could be described well using reactions and

  10. Surface Complexation Modeling of Organic Acid Sorption to Goethite.

    PubMed

    Evanko; Dzombak

    1999-06-15

    Surface complexation modeling was performed using the Generalized Two-Layer Model for a series of low molecular weight organic acids. Sorption of these organic acids to goethite was investigated in a previous study to assess the influence of particular structural features on sorption. Here, the ability to describe the observed sorption behavior for compounds with similar structural features using surface complexation modeling was investigated. A set of surface reactions and equilibrium constants yielding optimal data fits was obtained for each organic acid over a range of total sorbate concentrations. Surface complexation modeling successfully described sorption of a number of the simple organic acids, but an additional hydrophobic component was needed to describe sorption behavior of some compounds with significant hydrophobic character. These compounds exhibited sorption behavior that was inconsistent with ligand exchange mechanisms since sorption did not decrease with increasing total sorbate concentration and/or exceeded surface site saturation. Hydrophobic interactions appeared to be most significant for the compound containing a 5-carbon aliphatic chain. Comparison of optimized equilibrium constants for similar surface species showed that model results were consistent with observed sorption behavior: equilibrium constants were highest for compounds having adjacent carboxylic groups, lower for compounds with adjacent phenolic groups, and lowest for compounds with phenolic groups in the ortho position relative to a carboxylic group. Surface complexation modeling was also performed to fit sorption data for Suwannee River fulvic acid. The data could be described well using reactions and constants similar to those for pyromellitic acid. This four-carboxyl group compound may be useful as a model for fulvic acid with respect to sorption. Other simple organic acids having multiple carboxylic and phenolic functional groups were identified as potential models for humic

  11. Hydrogen generation from magnesium hydride by using organic acid

    NASA Astrophysics Data System (ADS)

    Ho, Yen-Hsi

    In this paper, the hydrolysis of solid magnesium hydride has been studied with the high concentration of catalyst at the varying temperature. An organic acid (acetic acid, CH3COOH) has been chosen as the catalyst. The study has three objectives: first, using three different weights of MgH 2 react with aqueous solution of acid for the hydrogen generation experiments. Secondly, utilizing acetic acid as the catalyst accelerates hydrogen generation. Third, emphasizing the combination of the three operating conditions (the weight of MgH2, the concentration of acetic acid, and the varying temperature) influence the amount of hydrogen generation. The experiments results show acetic acid truly can increase the rate of hydrogen generation and the weight of MgH2 can affect the amount of hydrogen generation more than the varying temperature.

  12. Distribution of hydrophobic ionogenic organic compounds between octanol and water: Organic acids

    SciTech Connect

    Jafvert, C.T. ); Westall, J.C. ); Grieder, E.; Schwarzenbach, R.P. )

    1990-12-01

    The octanol-water distributions of 10 environmentally significant organic acid compounds were determined as a function of aqueous-phase salt concentration (0.05-0.2 M LiCl, NaCl, KCl, CaCl{sub 2}, or MgCl{sub 2}) and pH. The compounds were pentachlorophenol, 2,3,4,5-tetrachlorophenol, (2,4,5-trichlorophenoxy)acetic acid, 4-chloro-{alpha}-(4-chlorophenyl)benzeneacetic acid, 2-methyl-4,6-dinitrophenol, (2,4-dichlorophenoxy) acetic acid, 4-(2,4-dichlorophenoxy) butanoic acid, 3,6-dichloro-2-methoxybenzoic acid, 2,3,6-trichlorobenzeneacetic acid, and 2-(2,4,5-trichlorophenoxy)propionic acid. The experimental results were interpreted quantitatively with an equilibrium model that accounts for acid dissociation in the aqueous phase and partitioning into the octanol phase by the neutral organic species, free inorganic and organic ions, and ion pairs. The partition constants for the neutral ion pairs correlate well with the partition constants of the neutral acids. Two experiments address the applicability of these octanol-water distribution data to the distribution of ionogenic compounds in the environment: the distribution of 2-methyl-4,6-dinitrophenol on a natural sorbent as a function of salt concentration (NaCl and CaCl{sub 2}) and pH, and competitive adsorption of pentachlorophenol and 2,3,4,5-tetrachlorophenol on an environmental sorbent.

  13. Particulate organic acids in the atmosphere of Italian cities: Are they environmentally relevant?

    NASA Astrophysics Data System (ADS)

    Balducci, Catia; Cecinato, Angelo

    2010-02-01

    Mono- and dicarboxylic n-alkyl acids were extensively investigated in downtown Rome, Italy, and in Montelibretti, ˜30 km NE of the city, during 2005-2007. Congeners ranging from lauric to mellisic, and from succinic to α,ω-docosanedioic acids were evaluated as well as phthalic, palmitoleic and oleic acids, by solvent extraction of airborne particulates followed by derivatization with propanol in the presence of boron trifluoride, and gas chromatographic-mass spectrometric analysis. Shorter measurements were made in Milan, in Taranto, at suburban and rural sites of Italy, and in the polar regions, from 1996 to 2005. The predominance of palmitic and stearic acids observed elsewhere was confirmed, and the behaviour of azelaic and phthalic acids resulted strongly dependent upon the year season. In the urban sites, among the long-chain compounds, the lignoceric acid was usually the most abundant, while the cerotic, montanic and mellisic homologues cumulatively never exceeded 8% of the total. Unlike other contaminants, the concentrations of organic acids remained fairly invariant over the last decade, suggesting that more attention must be paid to them in the future.

  14. Starch Modification by Organic Acids and Their Derivatives: A Review.

    PubMed

    Ačkar, Đurđica; Babić, Jurislav; Jozinović, Antun; Miličević, Borislav; Jokić, Stela; Miličević, Radoslav; Rajič, Marija; Šubarić, Drago

    2015-10-27

    Starch has been an inexhaustible subject of research for many decades. It is an inexpensive, readily-available material with extensive application in the food and processing industry. Researchers are continually trying to improve its properties by different modification procedures and expand its application. What is mostly applied in this view are their chemical modifications, among which organic acids have recently drawn the greatest attention, particularly with respect to the application of starch in the food industry. Namely, organic acids naturally occur in many edible plants and many of them are generally recognized as safe (GRAS), which make them ideal modification agents for starch intended for the food industry. The aim of this review is to give a short literature overview of the progress made in the research of starch esterification, etherification, cross-linking, and dual modification with organic acids and their derivatives.

  15. Determination of the Free Amino Acid, Organic Acid, and Nucleotide in Commercial Vinegars.

    PubMed

    Kong, Yan; Zhang, Li-Li; Sun, Ying; Zhang, Yu-Yu; Sun, Bao-Guo; Chen, Hai-Tao

    2017-03-29

    The selected taste-active compounds in several kinds of commercial vinegar including amino acids, organic acids, and nucleotides were determined by High Performance Liquid Chromatography (HPLC). The results showed that glutamine and alanine, which contribute the umami and sweet taste to the flavor of vinegar, are high in Taste Activity Value (TAV). Acetic acid is the major organic acid in vinegar, making up as much as 91.4% of the total organic acid composition. Nucleotides, which were only detected in 5 brands of commercial vinegar and are both low in TAV, contribute less taste in vinegar. Our research provides a multiple chemical compositional characterization of vinegar and proposes a possibility of classification of different kinds of vinegar.

  16. Influence of dissolved organic carbon content on modelling natural organic matter acid-base properties.

    PubMed

    Garnier, Cédric; Mounier, Stéphane; Benaïm, Jean Yves

    2004-10-01

    Natural organic matter (NOM) behaviour towards proton is an important parameter to understand NOM fate in the environment. Moreover, it is necessary to determine NOM acid-base properties before investigating trace metals complexation by natural organic matter. This work focuses on the possibility to determine these acid-base properties by accurate and simple titrations, even at low organic matter concentrations. So, the experiments were conducted on concentrated and diluted solutions of extracted humic and fulvic acid from Laurentian River, on concentrated and diluted model solutions of well-known simple molecules (acetic and phenolic acids), and on natural samples from the Seine river (France) which are not pre-concentrated. Titration experiments were modelled by a 6 acidic-sites discrete model, except for the model solutions. The modelling software used, called PROSECE (Programme d'Optimisation et de SpEciation Chimique dans l'Environnement), has been developed in our laboratory, is based on the mass balance equilibrium resolution. The results obtained on extracted organic matter and model solutions point out a threshold value for a confident determination of the studied organic matter acid-base properties. They also show an aberrant decreasing carboxylic/phenolic ratio with increasing sample dilution. This shift is neither due to any conformational effect, since it is also observed on model solutions, nor to ionic strength variations which is controlled during all experiments. On the other hand, it could be the result of an electrode troubleshooting occurring at basic pH values, which effect is amplified at low total concentration of acidic sites. So, in our conditions, the limit for a correct modelling of NOM acid-base properties is defined as 0.04 meq of total analysed acidic sites concentration. As for the analysed natural samples, due to their high acidic sites content, it is possible to model their behaviour despite the low organic carbon concentration.

  17. Regulation by organic acids of polysaccharide-mediated microbe-plant interactions.

    PubMed

    Nakata, K; Kobayashi, T; Takiguchi, Y; Yamaguchi, T

    2000-10-01

    A polysaccharide flocculant of Klebsiella pneumoniae H12 has been suggested to mediate microbe-plant interactions with the aid of Ca2+ [K. Nakata et al., Biosci. Biotechnol. Biochem., 64, 459-465, 2000]. Here, two-way regulation of polysaccharide-mediated interactions between K. pneumoniae and Raphanus sativus was studied using organic acids. Namely, 10 mM equivalents of organic acids promoted production of the polysaccharide by the bacterium, but inhibited flocculation of bacterial cells by the polysaccharide. These phenomena were counterbalanced by equi-molar equivalents of Ca2+, suggesting competition for Ca2+ between the carboxylic residues of the polysaccharide and those of the aliphatic acids. By electron microscopy observations, bacterial cell aggregates were sparsely distributed over the main roots and root hairs, had various sizes, and seemed to tightly adhere to root tissues. Their shapes seemed to be distorted and abundant in cavities. In brief, these microscopical observations may be explained by a two-way regulation system of bacterial adhesion to a plant by organic acids.

  18. Metabolic engineering in the biotechnological production of organic acids in the tricarboxylic acid cycle of microorganisms: Advances and prospects.

    PubMed

    Yin, Xian; Li, Jianghua; Shin, Hyun-Dong; Du, Guocheng; Liu, Long; Chen, Jian

    2015-11-01

    Organic acids, which are chemically synthesized, are also natural intermediates in the metabolic pathways of microorganisms, among which the tricarboxylic acid (TCA) cycle is the most crucial route existing in almost all living organisms. Organic acids in the TCA cycle include citric acid, α-ketoglutaric acid, succinic acid, fumaric acid, l-malic acid, and oxaloacetate, which are building-block chemicals with wide applications and huge markets. In this review, we summarize the synthesis pathways of these organic acids and review recent advances in metabolic engineering strategies that enhance organic acid production. We also propose further improvements for the production of organic acids with systems and synthetic biology-guided metabolic engineering strategies.

  19. Bio-based production of organic acids with Corynebacterium glutamicum.

    PubMed

    Wieschalka, Stefan; Blombach, Bastian; Bott, Michael; Eikmanns, Bernhard J

    2013-03-01

    The shortage of oil resources, the steadily rising oil prices and the impact of its use on the environment evokes an increasing political, industrial and technical interest for development of safe and efficient processes for the production of chemicals from renewable biomass. Thus, microbial fermentation of renewable feedstocks found its way in white biotechnology, complementing more and more traditional crude oil-based chemical processes. Rational strain design of appropriate microorganisms has become possible due to steadily increasing knowledge on metabolism and pathway regulation of industrially relevant organisms and, aside from process engineering and optimization, has an outstanding impact on improving the performance of such hosts. Corynebacterium glutamicum is well known as workhorse for the industrial production of numerous amino acids. However, recent studies also explored the usefulness of this organism for the production of several organic acids and great efforts have been made for improvement of the performance. This review summarizes the current knowledge and recent achievements on metabolic engineering approaches to tailor C. glutamicum for the bio-based production of organic acids. We focus here on the fermentative production of pyruvate, L- and D-lactate, 2-ketoisovalerate, 2-ketoglutarate, and succinate. These organic acids represent a class of compounds with manifold application ranges, e.g. in pharmaceutical and cosmetics industry, as food additives, and economically very interesting, as precursors for a variety of bulk chemicals and commercially important polymers.

  20. Sea salt particles react with organic acids in atmosphere

    NASA Astrophysics Data System (ADS)

    Balcerak, Ernie

    2012-10-01

    Sea salt, or sodium chloride (NaCl), particles lofted into the atmosphere by the motion of ocean waves affect atmospheric chemistry; these particles can undergo reactions with trace atmospheric gases and internal mixing with anthropogenic pollutants depositing on particle surface. Several studies have found that NaCl particles in the atmosphere are depleted in chloride and have attributed this to reactions with inorganic acids. However, reactions with inorganic acids do not fully account for the observed chloride depletion in some locations; it has been suggested that organic acids, likely of anthropogenic origin, may also play a role in chloride depletion, but results have been uncertain.

  1. The thermal stability of organic acids in sedimentary basins

    SciTech Connect

    Crossey, L.J. )

    1991-03-01

    Water-soluble organic compounds in subsurface brines directly affect the evolution of porosity and permeability during sedimentary diagenesis. Recent examination of the aqueous thermal degradation of oxalic acid (a naturally occurring dicarboxylic acid) and its anions has implications for the thermal stability of dicarboxylic acids under sedimentary basin conditions. Because the thermal stability of these compounds is pH-dependent, consideration of the dissociation behavior of carboxylic acids as a function of temperature is essential for estimating the longevity of difunctional carboxylic acids. Results of burial history models suggest that dicarboxylic acid species may be long-lived in formation waters. Comparison with other experimental studies of carboxylic acids and their anion indicates that acetate stability is greater than formate stability, which is greater than oxalate stability, which is greater than gallate and malonate stability. In addition to the implications of natural systems, the aqueous degradation behavior is critical in evaluating other types of experimental results; notably mineral dissolution studies performed at elevated temperatures in the presence of organic materials and hydrous pyrolysis experiments involving kerogens.

  2. Effect of inorganic salts on the volatility of organic acids.

    PubMed

    Häkkinen, Silja A K; McNeill, V Faye; Riipinen, Ilona

    2014-12-02

    Particulate phase reactions between organic and inorganic compounds may significantly alter aerosol chemical properties, for example, by suppressing particle volatility. Here, chemical processing upon drying of aerosols comprised of organic (acetic, oxalic, succinic, or citric) acid/monovalent inorganic salt mixtures was assessed by measuring the evaporation of the organic acid molecules from the mixture using a novel approach combining a chemical ionization mass spectrometer coupled with a heated flow tube inlet (TPD-CIMS) with kinetic model calculations. For reference, the volatility, i.e. saturation vapor pressure and vaporization enthalpy, of the pure succinic and oxalic acids was also determined and found to be in agreement with previous literature. Comparison between the kinetic model and experimental data suggests significant particle phase processing forming low-volatility material such as organic salts. The results were similar for both ammonium sulfate and sodium chloride mixtures, and relatively more processing was observed with low initial aerosol organic molar fractions. The magnitude of low-volatility organic material formation at an atmospherically relevant pH range indicates that the observed phenomenon is not only significant in laboratory conditions but is also of direct atmospheric relevance.

  3. [Simultaneous separation of organic acid and organic salts by electrostatic ion chromatography].

    PubMed

    Shen, G J; Yang, R F; Yu, A M

    2001-09-01

    The electrostatic ion chromatographic column was prepared by coating conjugated acid salt micelles on the surface of octadecyl silica stationary phase. Pure water was used as mobile phase, and the conductance detector was connected on-line to electrostatic ion chromatograph. The conditions under which organic acid and organic salts were detected were studied. The mechanism for the above separation is discussed. Sodium benzoate and citric acid in Lichee drink were separated and determined. This method is rapid, simple with little interference and good reproducibility without any pollution since the mobile phase is water. This is an environmental friendly analytical method.

  4. Comparative evaluation of volatiles, phenolics, sugars, organic acids and antioxidant properties of Sel-42 and Tainung papaya varieties.

    PubMed

    Kelebek, Hasim; Selli, Serkan; Gubbuk, Hamide; Gunes, Esma

    2015-04-15

    The present study was designed to determine the phenolic compounds, organic acids, sugars, aroma profiles and antioxidant properties of Sel-42 and Tainung papayas grown in Turkey. High-performance liquid chromatography/electrospray ionisation tandem mass spectrometry (HPLC-ESI-MS/MS) method was used for the phenolic compounds analysis. Twelve phenolic compounds were identified and quantified in the samples. The total phenolic content of Sel-42 was clearly higher than that of Tainung. Protocatechuic acid-hexoside, gallic acid-deoxyhexoside, ferulic acid and chlorogenic acids were the most abundant phenolics in both cultivars. Aroma composition of papaya was analysed by gas chromatography-mass spectrometry (GC-MS). A total of 46 and 42 aroma compounds, including esters, alcohols, terpenes, lactones, acids, carbonyl compounds, and volatile phenols were identified in the Sel-42 and Tainung, respectively. The significant linear correlation was confirmed between the values for the total phenolic content and antioxidant activity of papaya extracts.

  5. Application of organic acids for plant protection against phytopathogens.

    PubMed

    Morgunov, Igor G; Kamzolova, Svetlana V; Dedyukhina, Emilia G; Chistyakova, Tatiana I; Lunina, Julia N; Mironov, Alexey A; Stepanova, Nadezda N; Shemshura, Olga N; Vainshtein, Mikhail B

    2017-02-01

    The basic tendency in the field of plant protection concerns with reducing the use of pesticides and their replacement by environmentally acceptable biological preparations. The most promising approach to plant protection is application of microbial metabolites. In the last years, bactericidal, fungicidal, and nematodocidal activities were revealed for citric, succinic, α-ketoglutaric, palmitoleic, and other organic acids. It was shown that application of carboxylic acids resulted in acceleration of plant development and the yield increase. Of special interest is the use of arachidonic acid in very low concentrations as an inductor (elicitor) of protective functions in plants. The bottleneck in practical applications of these simple, nontoxic, and moderately priced preparations is the absence of industrial production of the mentioned organic acids of required quality since even small contaminations of synthetic preparations decrease their quality and make them dangerous for ecology and toxic for plants, animals, and human. This review gives a general conception on the use of organic acids for plant protection against the most dangerous pathogens and pests, as well as focuses on microbiological processes for production of these microbial metabolites of high quality from available, inexpensive, and renewable substrates.

  6. Formation of Organic Tracers for Isoprene SOA under Acidic Conditions

    EPA Science Inventory

    The chemical compositions of a series of secondary organic aerosol (SOA) samples, formed by irradiating mixtures of isoprene and NO in a smog chamber in the absence or presence of acidic aerosols, were analyzed using derivatization-based GC-MS methods. In addition to the known is...

  7. pH-Dependent sorption of acidic organic chemicals to soil organic matter.

    PubMed

    Tülp, Holger C; Fenner, Kathrin; Schwarzenbach, René P; Goss, Kai-Uwe

    2009-12-15

    Due to their increased polarity, many contemporary biologically active chemicals exhibit acid functions and may thus dissociate to their anionic conjugated base at pH values typically present in the environment. Despite its negative charge, soil organic matter (SOM) has been demonstrated to be the main sorbent in soils, even for the anionic species of organic acids. Nevertheless, few data exist that allow for a systematic interpretation of the sorption of organic acids into SOM. Therefore, in this study, the sorption of the neutral and anionic species of 32 diverse organic acids belonging to nine different chemical groups to SOM was investigated. Partition coefficients were determined from HPLC retention volumes on a column packed with peat, at three Ca(2+)-concentrations and over a pH range of 4.5-7.5. The influence of Ca(2+)-concentrations on anion sorption was small (factor 2 in the usual environmental Ca(2+)-concentration range) and independent of molecular structure. Generally, the organic carbon-water partition coefficients, K(oc), of both the neutral and anionic species increased with increasing molecular size and decreased with increasing polarity. At an environmentally relevant Ca(2+)-concentration of 10 mM, the investigated anions sorbed between a factor of 7-60 less than the corresponding neutral acid. This factor was more homogeneous within a group of structurally related compounds. These results indicate that while similar nonionic interactions seem to govern the partitioning of both the neutral and anionic species into SOM, the electrostatic interactions of the anionic species with SOM are a complex and currently not well understood function of the type of acidic functional group. The HPLC-based, flow through method presented in this study was shown to yield consistent results for a wide range of organic acids in a high-throughput manner. It should therefore prove highly useful in further investigating how different acidic functional groups affect

  8. Acid rain effects on aluminum mobilization clarified by inclusion of strong organic acids

    USGS Publications Warehouse

    Lawrence, G.B.; Sutherland, J.W.; Boylen, C.W.; Nierzwicki-Bauer, S. W.; Momen, B.; Baldigo, Barry P.; Simonin, H.A.

    2007-01-01

    Assessments of acidic deposition effects on aquatic ecosystems have often been hindered by complications from naturally occurring organic acidity. Measurements of pH and ANCG, the most commonly used indicators of chemical effects, can be substantially influenced by the presence of organic acids. Relationships between pH and inorganic Al, which is toxic to many forms of aquatic biota, are also altered by organic acids. However, when inorganic Al concentrations are plotted against ANC (the sum of Ca2+, Mg 2+, Na+, and K+, minus SO42-, NO3-, and Cl-), a distinct threshold for Al mobilization becomes apparent. If the concentration of strong organic anions is included as a negative component of ANC, the threshold occurs at an ANC value of approximately zero, the value expected from theoretical charge balance constraints. This adjusted ANC is termed the base-cation surplus. The threshold relationship between the base-cation surplus and Al was shown with data from approximately 200 streams in the Adirondack region of New York, during periods with low and high dissolved organic carbon concentrations, and for an additional stream from the Catskill region of New York. These results indicate that (1) strong organic anions can contribute to the mobilization of inorganic Al in combination with SO42- and NO 3-, and (2) the presence of inorganic Al in surface waters is an unambiguous indication of acidic deposition effects. ?? 2007 American Chemical Society.

  9. Acid rain effects on aluminum mobilization clarified by inclusion of strong organic acids.

    PubMed

    Lawrence, G B; Sutherland, J W; Boylen, C W; Nierzwicki-Bauer, S W; Momen, B; Baldigo, B P; Simonin, H A

    2007-01-01

    Assessments of acidic deposition effects on aquatic ecosystems have often been hindered by complications from naturally occurring organic acidity. Measurements of pH and ANCG, the most commonly used indicators of chemical effects, can be substantially influenced by the presence of organic acids. Relationships between pH and inorganic Al, which is toxic to many forms of aquatic biota, are also altered by organic acids. However, when inorganic Al concentrations are plotted against ANC (the sum of Ca2+, Mg2+, Na+, and K+, minus S042-, N03-, and Cl-), a distinct threshold for Al mobilization becomes apparent. If the concentration of strong organic anions is included as a negative component of ANC, the threshold occurs at an ANC value of approximately zero, the value expected from theoretical charge balance constraints. This adjusted ANC is termed the base-cation surplus. The threshold relationship between the base-cation surplus and Al was shown with data from approximately 200 streams in the Adirondack region of New York, during periods with low and high dissolved organic carbon concentrations, and for an additional stream from the Catskill region of New York. These results indicate that (1) strong organic anions can contribute to the mobilization of inorganic Al in combination with SO42- and N03-, and (2) the presence of inorganic Al in surface waters is an unambiguous indication of acidic deposition effects.

  10. Removal of lead by apatite and its stability in the presence of organic acids.

    PubMed

    Katoh, Masahiko; Makimura, Akihiko; Sato, Takeshi

    2016-12-01

    In this study, lead sorption and desorption tests were conducted with apatite and organic acids (i.e. citric, malic, and formic acids) to understand lead removal by apatite in the presence of an organic acid and lead dissolution from the lead- and organic-acid-sorbed apatite by such organic acid exposure. The lead sorption test showed that the amount of lead removed by apatite in the presence of organic acid varied depending on the type of acid used. The molar amounts of calcium dissolved from apatite in the presence and absence of organic acid were exactly the same as those of lead removed even under different pH conditions as well as different organic acid concentrations, indicating that the varying amount of lead removal in the presence of different organic acids resulted from the magnitude of the dissolution of apatite and the precipitation of lead phosphate minerals. The percentages of lead dissolved from the organic-acid-sorbed and non-organic-acid-sorbed apatite by all the organic acid extractions were equal and higher than those by water extraction. In particular, the highest extractions were observed in the non-organic-acid-sorbed apatite by citric and malic acids. These results suggest that to immobilize lead by the use of apatite in the presence of organic acids, much more apatite must be added than in the absence of organic acid, and that measures must be taken to ensure that the immobilized lead is not dissolved.

  11. Chronic hypoxia and VEGF differentially modulate abundance and organization of myosin heavy chain isoforms in fetal and adult ovine arteries.

    PubMed

    Hubbell, Margaret C; Semotiuk, Andrew J; Thorpe, Richard B; Adeoye, Olayemi O; Butler, Stacy M; Williams, James M; Khorram, Omid; Pearce, William J

    2012-11-15

    Chronic hypoxia increases vascular endothelial growth factor (VEGF) and thereby promotes angiogenesis. The present study explores the hypothesis that hypoxic increases in VEGF also remodel artery wall structure and contractility through phenotypic transformation of smooth muscle. Pregnant and nonpregnant ewes were maintained at sea level (normoxia) or 3,820 m (hypoxia) for the final 110 days of gestation. Common carotid arteries harvested from term fetal lambs and nonpregnant adults were denuded of endothelium and studied in vitro. Stretch-dependent contractile stresses were 32 and 77% of normoxic values in hypoxic fetal and adult arteries. Hypoxic hypocontractility was coupled with increased abundance of nonmuscle myosin heavy chain (NM-MHC) in fetal (+37%) and adult (+119%) arteries. Conversely, hypoxia decreased smooth muscle MHC (SM-MHC) abundance by 40% in fetal arteries but increased it 123% in adult arteries. Hypoxia decreased colocalization of NM-MHC with smooth muscle α-actin (SM-αA) in fetal arteries and decreased colocalization of SM-MHC with SM-αA in adult arteries. Organ culture with physiological concentrations (3 ng/ml) of VEGF-A(165) similarly depressed stretch-dependent stresses to 37 and 49% of control fetal and adult values. The VEGF receptor antagonist vatalanib ablated VEGF's effects in adult but not fetal arteries, suggesting age-dependent VEGF receptor signaling. VEGF replicated hypoxic decreases in colocalization of NM-MHC with SM-αA in fetal arteries and decreases in colocalization of SM-MHC with SM-αA in adult arteries. These results suggest that hypoxic increases in VEGF not only promote angiogenesis but may also help mediate hypoxic arterial remodeling through age-dependent changes in smooth muscle phenotype and contractility.

  12. Photodissociation of organic molecules in star-forming regions. II. Acetic acid

    NASA Astrophysics Data System (ADS)

    Pilling, S.; Santos, A. C. F.; Boechat-Roberty, H. M.

    2006-04-01

    Fragments from organic molecule dissociation (such as reactive ions and radicals) can form interstellar complex molecules like amino acids. The goal of this work is to experimentally study photoionization and photodissociation processes of acetic acid (CH3COOH), a glycine (NH2CH2COOH) precursor molecule, by soft X-ray photons. The measurements were taken at the Brazilian Synchrotron Light Laboratory (LNLS), employing soft X-ray photons from a toroidal grating monochromator (TGM) beamline (100-310 eV). Mass spectra were obtained using the photoelectron photoion coincidence (PEPICO) method. Kinetic energy distribution and abundances for each ionic fragment have been obtained from the analysis of the corresponding peak shapes in the mass spectra. Absolute photoionization and photodissociation cross sections were also determined. We have found, among the channels leading to ionization, that only 4-6% of CH3COOH survive the strong ionization field. CH3CO^+, COOH+ and CH3+ ions are the main fragments, and the presence of the former may indicate that the production-destruction process of acetic acid in hot molecular cores (HMCs) could decrease the H2O abundance since the net result of this process converts H2O into OH + H^+. The COOH+ ion plays an important role in ion-molecule reactions to form large biomolecules like glycine.

  13. High-throughput quantification of the levels and labeling abundance of free amino acids by liquid chromatography tandem mass spectrometry.

    PubMed

    Cocuron, Jean-Christophe; Tsogtbaatar, Enkhtuul; Alonso, Ana P

    2017-03-24

    Accurate assessment of mass isotopomer distributions (MIDs) of intracellular metabolites, such as free amino acids (AAs), is crucial for quantifying in vivo fluxes. To date, the majority of studies that measured AA MIDs have relied on the analysis of proteinogenic rather than free AAs by: i) GC-MS, which involved cumbersome process of derivatization, or ii) NMR, which requires large quantities of biological sample. In this work, the development and validation of a high-throughput LC-MS/MS method allowing the quantification of the levels and labeling of free AAs is described. Sensitivity in the order of the femtomol was achieved using multiple reaction monitoring mode (MRM). The MIDs of all free AAs were assessed without the need of derivatization, and were validated (except for Trp) on a mixture of unlabeled AA standards. Finally, this method was applied to the determination of the (13)C-labeling abundance in free AAs extracted from maize embryos cultured with (13)C-glutamine or (13)C-glucose. Although Cys was below the limit of detection in these biological samples, the MIDs of a total of 18 free AAs were successfully determined. Due to the increased application of tandem mass spectrometry for (13)C-Metabolic Flux Analysis, this novel method will enable the assessment of more complete and accurate labeling information of intracellular AAs, and therefore a better definition of the fluxes.

  14. Organic acid modeling and model validation: Workshop summary. Final report

    SciTech Connect

    Sullivan, T.J.; Eilers, J.M.

    1992-08-14

    A workshop was held in Corvallis, Oregon on April 9--10, 1992 at the offices of E&S Environmental Chemistry, Inc. The purpose of this workshop was to initiate research efforts on the entitled ``Incorporation of an organic acid representation into MAGIC (Model of Acidification of Groundwater in Catchments) and testing of the revised model using Independent data sources.`` The workshop was attended by a team of internationally-recognized experts in the fields of surface water acid-bass chemistry, organic acids, and watershed modeling. The rationale for the proposed research is based on the recent comparison between MAGIC model hindcasts and paleolimnological inferences of historical acidification for a set of 33 statistically-selected Adirondack lakes. Agreement between diatom-inferred and MAGIC-hindcast lakewater chemistry in the earlier research had been less than satisfactory. Based on preliminary analyses, it was concluded that incorporation of a reasonable organic acid representation into the version of MAGIC used for hindcasting was the logical next step toward improving model agreement.

  15. Organic acid modeling and model validation: Workshop summary

    SciTech Connect

    Sullivan, T.J.; Eilers, J.M.

    1992-08-14

    A workshop was held in Corvallis, Oregon on April 9--10, 1992 at the offices of E S Environmental Chemistry, Inc. The purpose of this workshop was to initiate research efforts on the entitled Incorporation of an organic acid representation into MAGIC (Model of Acidification of Groundwater in Catchments) and testing of the revised model using Independent data sources.'' The workshop was attended by a team of internationally-recognized experts in the fields of surface water acid-bass chemistry, organic acids, and watershed modeling. The rationale for the proposed research is based on the recent comparison between MAGIC model hindcasts and paleolimnological inferences of historical acidification for a set of 33 statistically-selected Adirondack lakes. Agreement between diatom-inferred and MAGIC-hindcast lakewater chemistry in the earlier research had been less than satisfactory. Based on preliminary analyses, it was concluded that incorporation of a reasonable organic acid representation into the version of MAGIC used for hindcasting was the logical next step toward improving model agreement.

  16. Bio-based production of organic acids with Corynebacterium glutamicum

    PubMed Central

    Wieschalka, Stefan; Blombach, Bastian; Bott, Michael; Eikmanns, Bernhard J

    2013-01-01

    The shortage of oil resources, the steadily rising oil prices and the impact of its use on the environment evokes an increasing political, industrial and technical interest for development of safe and efficient processes for the production of chemicals from renewable biomass. Thus, microbial fermentation of renewable feedstocks found its way in white biotechnology, complementing more and more traditional crude oil-based chemical processes. Rational strain design of appropriate microorganisms has become possible due to steadily increasing knowledge on metabolism and pathway regulation of industrially relevant organisms and, aside from process engineering and optimization, has an outstanding impact on improving the performance of such hosts. Corynebacterium glutamicum is well known as workhorse for the industrial production of numerous amino acids. However, recent studies also explored the usefulness of this organism for the production of several organic acids and great efforts have been made for improvement of the performance. This review summarizes the current knowledge and recent achievements on metabolic engineering approaches to tailor C. glutamicum for the bio-based production of organic acids. We focus here on the fermentative production of pyruvate, l-and d-lactate, 2-ketoisovalerate, 2-ketoglutarate, and succinate. These organic acids represent a class of compounds with manifold application ranges, e.g. in pharmaceutical and cosmetics industry, as food additives, and economically very interesting, as precursors for a variety of bulk chemicals and commercially important polymers. Funding Information Work in the laboratories of the authors was supported by the Fachagentur Nachwachsende Rohstoffe (FNR) of the Bundesministerium für Ernährung, Landwirtschaft und Verbraucherschutz (BMELV; FNR Grants 220-095-08A and 220-095-08D; Bio-ProChemBB project, ERA-IB programme), by the Deutsche Bundesstiftung Umwelt (DBU Grant AZ13040/05) and the Evonik Degussa AG. PMID

  17. Various instrumental approaches for determination of organic acids in wines.

    PubMed

    Zeravik, Jiri; Fohlerova, Zdenka; Milovanovic, Miodrag; Kubesa, Ondrej; Zeisbergerova, Marta; Lacina, Karel; Petrovic, Aleksandar; Glatz, Zdenek; Skladal, Petr

    2016-03-01

    Biosensors based on lactate oxidase, sarcosine oxidase and mixture of fumarase and sarcosine oxidase were used for monitoring of organic acids in wine samples. Additionally, tartaric acid was determined by modified colorimetric method based on formation of the vanadate-tartrate complex. The above mentioned methods were used for the analysis of 31 wine samples and obtained data were compared with the results from capillary electrophoresis as a basic standard method. This comparison showed a certain degree of correlation between biosensors and capillary electrophoresis. The provided information pointed to the potential uses of biosensors in the field of winemaking.

  18. Factors governing abundance of hydrolyzable amino acids in the sediments from the N.W. European Continental Margin (47 50°N)

    NASA Astrophysics Data System (ADS)

    Boski, T.; Pessoa, J.; Pedro, P.; Thorez, J.; Dias, J. M. A.; Hall, I. R.

    1998-12-01

    Fifty-six samples representing 6 sediment cores taken along the N.W. European Continental Margin from the shelf, slope and abyssal plain of the Goban Spur and Meriadzek Terrace were quantitatively analysed for total hydrolyzable amino acids (THAA) and clay minerals. In descending order, the five most abundant amino acids making up more than 70% of the total were: aspartic acid, glycine, serine, alanine and glutamic acid. Clay mineral proportions were typical for the N.E. Atlantic, in order of descending abundance: illite, kaolinite, chlorite, smectite and mixed layers. The Meriadzek Terrace area is characterised by fine grain suspension sedimentation with a low pelagic carbonate input and the lowest content of THAA. In contrast, the Goban Spur transect is characterised by much higher carbonate inputs and more vigorous hydrodynamics as judged from granulometry and the high abundance of minerals of shelf and continental origin and a generally higher THAA content. The pelagic portion of THAA deposited at the sea floor is more readily mineralised during early diagenesis than the more `refractory', clay mineral-associated continental portion. Along this margin the average mineralization of THAA down to 25 cm in the sediment is about 54%. There is a significant affinity between chlorites and amino acids which we suggest may involve the formation of ionic bonds between the octahedral layers of the clay and the amino acids.

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

    PubMed

    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.

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

    PubMed Central

    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

  1. Molecular characterization of dissolved organic matter in glacial ice: coupling natural abundance 1H NMR and fluorescence spectroscopy.

    PubMed

    Pautler, Brent G; Woods, Gwen C; Dubnick, Ashley; Simpson, André J; Sharp, Martin J; Fitzsimons, Sean J; Simpson, Myrna J

    2012-04-03

    Glaciers and ice sheets are the second largest freshwater reservoir in the global hydrologic cycle, and the onset of global climate warming has necessitated an assessment of their contributions to sea-level rise and the potential release of nutrients to nearby aquatic environments. In particular, the release of dissolved organic matter (DOM) from glacier melt could stimulate microbial activity in both glacial ecosystems and adjacent watersheds, but this would largely depend on the composition of the material released. Using fluorescence and (1)H NMR spectroscopy, we characterize DOM at its natural abundance in unaltered samples from a number of glaciers that differ in geographic location, thermal regime, and sample depth. Parallel factor analysis (PARAFAC) modeling of DOM fluorophores identifies components in the ice that are predominantly proteinaceous in character, while (1)H NMR spectroscopy reveals a mixture of small molecules that likely originate from native microbes. Spectrofluorescence also reveals a terrestrial contribution that was below the detection limits of NMR; however, (1)H nuclei from levoglucosan was identified in Arctic glacier ice samples. This study suggests that the bulk of the DOM from these glaciers is a mixture of biologically labile molecules derived from microbes.

  2. Computational and Statistical Analyses of Amino Acid Usage and Physico-Chemical Properties of the Twelve Late Embryogenesis Abundant Protein Classes

    PubMed Central

    Jaspard, Emmanuel; Macherel, David; Hunault, Gilles

    2012-01-01

    Late Embryogenesis Abundant Proteins (LEAPs) are ubiquitous proteins expected to play major roles in desiccation tolerance. Little is known about their structure - function relationships because of the scarcity of 3-D structures for LEAPs. The previous building of LEAPdb, a database dedicated to LEAPs from plants and other organisms, led to the classification of 710 LEAPs into 12 non-overlapping classes with distinct properties. Using this resource, numerous physico-chemical properties of LEAPs and amino acid usage by LEAPs have been computed and statistically analyzed, revealing distinctive features for each class. This unprecedented analysis allowed a rigorous characterization of the 12 LEAP classes, which differed also in multiple structural and physico-chemical features. Although most LEAPs can be predicted as intrinsically disordered proteins, the analysis indicates that LEAP class 7 (PF03168) and probably LEAP class 11 (PF04927) are natively folded proteins. This study thus provides a detailed description of the structural properties of this protein family opening the path toward further LEAP structure - function analysis. Finally, since each LEAP class can be clearly characterized by a unique set of physico-chemical properties, this will allow development of software to predict proteins as LEAPs. PMID:22615859

  3. Effects of clofibric acid alone and in combination with 17β-estradiol on mRNA abundance in primary hepatocytes isolated from rainbow trout.

    PubMed

    Sovadinová, I; Liedtke, A; Schirmer, K

    2014-09-01

    Clofibric acid (CA) is the active substance of lipid lowering drugs. It is resistant to degradation, polar in nature, and has been found ubiquitously in the aquatic environment. Though CA is classified as a peroxisomal proliferator in rodents and is considered as a potential endocrine disruptor, little information exists on the effects of CA in aquatic organisms, such as fish. In the present study, we examined the mRNA levels of peroxisome proliferator- and estrogen-sensitive genes on the exposure of primary rainbow trout (Oncorhynchus mykiss) hepatocytes to CA alone and in combination with the natural female sex hormone, 17β-estradiol (E2). Our results demonstrate that rainbow trout hepatocytes are relatively refractory to the effects of CA on the PPAR signaling pathway and lipid metabolism. Moreover, CA did not show recognizable estrogenic activity, but after the induction of vitellogenesis by E2, CA significantly reduced vitellogenin (VTG) mRNA abundance. Apparently, the indirect repression of VTG transcription, independent of estrogen receptors, occurred. The mechanism is not yet clearly understood but may involve disruption of the stabilization of VTG mRNA known to be induced by E2.

  4. Microbiological degradation of organic components in oil shale retort water: organic acids.

    PubMed

    Rogers, J E; Riley, R G; Li, S W; Mann, D C; Wildung, R E

    1981-11-01

    The losses of benzoic acid and a homologous series of both mono- and dibasic aliphatic acids in oil shale retort water were monitored with time (21 days) in liquid culture (4% retort water, vol/vol) inoculated with soil. The organic acids constituted approximately 12% of the dissolved organic carbon in retort water, which served as the sole source of carbon and energy in these studies. The levels of the acids in solution were reduced by 80 to 90% within 9 days of incubation. From mass balance calculations, the decrease in dissolved organic carbon with time of incubation was equal to the formation of CO(2) and bacterial cell carbon. The decrease in the level of the acid components, either from degradation to CO(2) or incorporation into bacteria, would account for approximately 70% of the loss in dissolved organic carbon within the first 9 days of incubation and would account for approximately 50% of the loss over the entire 21-day incubation period.

  5. Change of monochloroacetic acid to biodegradable organic acids by hydrothermal reaction.

    PubMed

    Kim, Kyoungrean; Fujita, Masafumi; Daimon, Hiroyuki; Fujie, Koichi

    2004-04-30

    The feasibility of biodegradability improvement induced from the structural conversion of refractory pollutants by hydrothermal reaction was investigated. Monochloroacetic acid (MCAA) was selected as a preliminary material represented for linear hydrocarbon structured refractory pollutants. Under the tested conditions, MCAA was partially destructed and then converted to biodegradable reaction products by hydrolysis, dehydration and thermal decomposition. The identified products were glycolic acid, citric acid and formic acid. Total organic carbon (TOC) reduction during the structural conversion did not exceed 24%, except the results at the reaction conditions of 350 degrees C and 17 MPa. However, Produced biodegradable organic acids were reduced by thermal decomposition with increasing reaction temperature and time. At the reaction temperature of 250 and 300 degrees C, biodegradability (BOD/COD(Cr)) was reached at 0.51 in 6.9 min and 0.52 in 7.4 min despite the presence of dissociated chlorine ions. The detachment of recalcitrant chlorine ion from MCAA and the production of biodegradable organic acids by hydrothermal reaction were directly related to the biodegradability improvement of reaction products.

  6. Amino Acid, Organic Acid, and Sugar Profiles of 3 Dry Bean (Phaseolus vulgaris L.) Varieties.

    PubMed

    John, K M Maria; Luthria, Devanand

    2015-12-01

    In this study, we compared the amino acid, organic acid and sugar profiles of 3 different varieties of dry beans (black bean [BB], dark red bean [DRB], and cranberry bean [CB]). The efficiency of the 2 commonly used extraction solvents (water and methanol:chloroform:water [2.5:1:1, v/v/v/]) for cultivar differentiation based on their metabolic profile was also investigated. The results showed that the BB contained the highest concentration of amino acids followed by DRB and CB samples. Phenylalanine, a precursor for the biosynthesis of phenolic secondary metabolites was detected at low concentration in CB samples and correlated with the reduced anthocyanins content in CB extract as documented in the published literature. Comparing the extractability of 2 extraction solvents, methanol:chloroform:water (2.5:1:1, v/v/v/) showed higher recoveries of amino acids from 3 beans, whereas, sugars were extracted in higher concentration with water. Analytically, gas chromatography detected sugars (9), amino acids (11), and organic acids (3) in a single run after derivatization of the extracts. In comparison, ion chromatography detected only sugars in a single run without any derivatization step with the tested procedure. Bean samples are better differentiated by the sugar content extracted with water as compared to the aqueous organic solvent extracts using partial least-square discriminant analysis.

  7. External concentration of organic acid anions and pH: key independent variables for studying how organic acids inhibit growth of bacteria in mildly acidic foods.

    PubMed

    Carpenter, C E; Broadbent, J R

    2009-01-01

    Although the mechanisms by which organic acids inhibit growth of bacteria in mildly acidic foods are not fully understood, it is clear that intracellular accumulation of anions is a primary contributor to inhibition of bacterial growth. We hypothesize that intracellular accumulation of anions is driven by 2 factors, external anion concentration and external acidity. This hypothesis follows from basic chemistry principles that heretofore have not been fully applied to studies in the field, and it has led us to develop a novel approach for predicting internal anion concentration by controlling the external concentration of anions and pH. This approach overcomes critical flaws in contemporary experimental design that invariably target concentration of either protonated acid or total acid in the growth media thereby leaving anion concentration to vary depending on the pK(a) of the acids involved. Failure to control external concentration of anions has undoubtedly confounded results, and it has likely led to misleading conclusions regarding the antimicrobial action of organic acids. In summary, we advocate an approach for directing internal anion levels by controlling external concentration of anions and pH because it presents an additional opportunity to study the mechanisms by which organic acids inhibit bacterial growth. Knowledge gained from such studies would have important application in the control of important foodborne pathogens such as Listeria monocytogenes, and may also facilitate efforts to promote the survival in foods or beverages of desirable probiotic bacteria.

  8. Dietary sunflower oil modulates milk fatty acid composition without major changes in adipose and mammary tissue fatty acid profile or related gene mRNA abundance in sheep.

    PubMed

    Castro-Carrera, T; Frutos, P; Leroux, C; Chilliard, Y; Hervás, G; Belenguer, A; Bernard, L; Toral, P G

    2015-04-01

    There are very few studies in ruminants characterizing mammary and adipose tissue (AT) expression of genes and gene networks for diets causing variations in milk fatty acid (FA) composition without altering milk fat secretion, and even less complementing this information with data on tissue FA profiles. This work was conducted in sheep in order to investigate the response of the mammary gland and the subcutaneous and perirenal AT, in terms of FA profile and mRNA abundance of genes involved in lipid metabolism, to a diet known to modify milk FA composition. Ten lactating Assaf ewes were randomly assigned to two treatments consisting of a total mixed ration based on alfalfa hay and a concentrate (60 : 40) supplemented with 0 (control diet) or 25 (SO diet) g of sunflower oil/kg of diet dry matter for 7 weeks. Milk composition, including FA profile, was analysed after 48 days on treatments. On day 49, the animals were euthanized and tissue samples were collected to analyse FA and mRNA abundance of 16 candidate genes. Feeding SO did not affect animal performance but modified milk FA composition. Major changes included decreases in the concentration of FA derived from de novo synthesis (e.g. 12:0, 14:0 and 16:0) and increases in that of long-chain FA (e.g. 18:0, c9-18:1, trans-18:1 isomers and c9,t11-CLA); however, they were not accompanied by significant variations in the mRNA abundance of the studied lipogenic genes (i.e. ACACA, FASN, LPL, CD36, FABP3, SCD1 and SCD5) and transcription factors (SREBF1 and PPARG), or in the constituent FA of mammary tissue. Regarding the FA composition of AT, the little influence of SO did not appear to be linked to changes in gene mRNA abundance (decreases of GPAM and SREBF1 in both tissues, and of PPARG in the subcutaneous depot). Similarly, the great variation between AT (higher contents of saturated FA and trans-18:1 isomers in the perirenal, and of cis-18:1, c9,t11-CLA and n-3 PUFA in the subcutaneous AT) could not be related to

  9. Assessment of bioavailable organic phosphorus in tropical forest soils by organic acid extraction and phosphatase hydrolysis.

    PubMed

    Darch, Tegan; Blackwell, Martin S A; Chadwick, David; Haygarth, Philip M; Hawkins, Jane M B; Turner, Benjamin L

    2016-12-15

    Soil organic phosphorus contributes to the nutrition of tropical trees, but is not accounted for in standard soil phosphorus tests. Plants and microbes can release organic anions to solubilize organic phosphorus from soil surfaces, and synthesize phosphatases to release inorganic phosphate from the solubilized compounds. We developed a procedure to estimate bioavailable organic phosphorus in tropical forest soils by simulating the secretion processes of organic acids and phosphatases. Five lowland tropical forest soils with contrasting properties (pH 4.4-6.1, total P 86-429 mg P kg(- 1)) were extracted with 2 mM citric acid (i.e., 10 μmol g(- 1), approximating rhizosphere concentrations) adjusted to soil pH in a 4:1 solution to soil ratio for 1 h. Three phosphatase enzymes were then added to the soil extract to determine the forms of hydrolysable organic phosphorus. Total phosphorus extracted by the procedure ranged between 3.22 and 8.06 mg P kg(- 1) (mean 5.55 ± 0.42 mg P kg(- 1)), of which on average three quarters was unreactive phosphorus (i.e., organic phosphorus plus inorganic polyphosphate). Of the enzyme-hydrolysable unreactive phosphorus, 28% was simple phosphomonoesters hydrolyzed by phosphomonoesterase from bovine intestinal mucosa, a further 18% was phosphodiesters hydrolyzed by a combination of nuclease from Penicillium citrinum and phosphomonoesterase, and the remaining 51% was hydrolyzed by a broad-spectrum phytase from wheat. We conclude that soil organic phosphorus can be solubilized and hydrolyzed by a combination of organic acids and phosphatase enzymes in lowland tropical forest soils, indicating that this pathway could make a significant contribution to biological phosphorus acquisition in tropical forests. Furthermore, we have developed a method that can be used to assess the bioavailability of this soil organic phosphorus.

  10. Biochar: a green sorbent to sequester acidic organic contaminants

    NASA Astrophysics Data System (ADS)

    Sigmund, Gabriel; Kah, Melanie; Sun, Huichao; Hofmann, Thilo

    2015-04-01

    Biochar is a carbon rich product of biomass pyrolysis that exhibits a high sorption potential towards a wide variety of inorganic and organic contaminants. Because it is a valuable soil additive and a potential carbon sink that can be produced from renewable resources, biochar has gained growing attention for the development of more sustainable remediation strategies. A lot of research efforts have been dedicated to the sorption of hydrophobic contaminants and metals to biochar. Conversely, the understanding of the sorption of acidic organic contaminants remains limited, and questions remain on the influence of biochar characteristics (e.g. ash content) on the sorption behaviour of acidic organic contaminants. To address this knowledge gap, sorption batch experiments were conducted with a series of structurally similar acidic organic contaminants covering a range of dissociation constant (2,4-D, MCPA, 2,4-DB and triclosan). The sorbents selected for experimentation included a series of 10 biochars covering a range of characteristics, multiwalled carbon nanotubes as model for pure carbonaceous phases, and an activated carbon as benchmark. Overall, sorption coefficient [L/kg] covered six orders of magnitude and generally followed the order 2,4-D < MCPA < 2,4-DB < triclosan. Combining comprehensive characterization of the sorbents with the sorption dataset allowed the discussion of sorption mechanisms and driving factors of sorption. Statistical analysis suggests that (i) partitioning was the main driver for sorption to sorbents with small specific surface area (< 25 m²/g), whereas (ii) specific mechanisms dominated sorption to sorbents with larger specific surface area. Results showed that factors usually not considered for the sorption of neutral contaminants play an important role for the sorption of organic acids. The pH dependent lipophilicity ratio (i.e. D instead of Kow), ash content and ionic strength are key factors influencing the sorption of acidic organic

  11. Impacts of oxidation aging on secondary organic aerosol formation, particle growth rate, cloud condensation nuclei abundance, and aerosol climate forcing

    NASA Astrophysics Data System (ADS)

    Yu, F.; Luo, G.

    2014-12-01

    Particle composition measurements indicate that organic aerosol (OA) makes up ~20-90% of submicron particulate mass and secondary OA (SOA) accounts for a large fraction (~ 72 ±21%) of these OA masses at many locations around the globe. The volatility changes of secondary organic gases (SOG) associated with oxidation aging as well as the contribution of highly oxidized low volatile SOG (LV-SOG) to the condensational growth of secondary particles have been found to be important in laboratory and field measurements but are poorly represented in global models. A novel scheme to extend the widely used two-product SOA formation model, by adding a third product arising from the oxidation aging (i.e., LV-SOG) and considering the dynamic transfer of mass from higher to lower volatile products, has been developed and implemented into a global chemical transport model (GEOS-Chem) and a community atmosphere model (CESM-CAM5). The scheme requires only minor changes to the existing two-product SOA formation model and is computationally efficient. With the oxidation rate constrained by laboratory measurements, we show that the new scheme predicts a much higher SOA mass concentrations, improving the agreement with aerosol mass spectrometer SOA measurements. The kinetic condensation of LV-SOG on ultrafine particles, simulated by a size-resolved (sectional) advanced particle microphysics (APM) model incorporated into in GEOS-Chem and CAM5, increases the particle growth rate substantially and improves the agreement of simulated cloud condensation nuclei (CCN) concentrations with observations. Based on GEOS-Chem-APM simulations, the new SOA formation scheme increases global mean low troposphere SOA mass concentration by ~130% and CCN abundance by ~ 15%, and optical depth of secondary particles and coated black carbon and primary organic carbon particles by ~10%. As a result, aerosol radiative cooling effect (direct + first indirect) is enhanced by -0.9 W/m2, with large spatial

  12. Natural abundance 13C and 14C analysis of water-soluble organic carbon in atmospheric aerosols.

    PubMed

    Kirillova, Elena N; Sheesley, Rebecca J; Andersson, August; Gustafsson, Örjan

    2010-10-01

    Water-soluble organic carbon (WSOC) constitutes a large fraction of climate-forcing organic aerosols in the atmosphere, yet the sources of WSOC are poorly constrained. A method was developed to measure the stable carbon isotope (δ(13)C) and radiocarbon (Δ(14)C) composition of WSOC for apportionment between fossil fuel and different biogenic sources. Synthetic WSOC test substances and ambient aerosols were employed to investigate the effect of both modern and fossil carbon contamination and any method-induced isotope fractionation. The method includes extraction of aerosols collected on quartz filters followed by purification and preparation for off-line δ(13)C and Δ(14)C determination. The preparative freeze-drying step for isotope analysis yielded recoveries of only ∼70% for ambient aerosols and WSOC probes. However, the δ(13)C of the WSOC isolates were in agreement with the δ(13)C of the unprocessed starting material, even for the volatile oxalic acid probe (6.59 ± 0.37‰ vs 6.33 ± 0.31‰; 2 sd). A (14)C-fossil phthalic acid WSOC probe returned a fraction modern biomass of <0.008 whereas a (14)C-modern sucrose standard yielded a fraction modern of >0.999, indicating the Δ(14)C-WSOC method to be free of both fossil and contemporary carbon contamination. Application of the δ(13)C/Δ(14)C-WSOC method to source apportion climate-affecting aerosols was illustrated be constraining that WSOC in ambient Stockholm aerosols were 88% of contemporary biogenic C3 plant origin.

  13. Capillary Electrophoresis Analysis of Organic Amines and Amino Acids in Saline and Acidic Samples Using the Mars Organic Analyzer

    NASA Astrophysics Data System (ADS)

    Stockton, Amanda M.; Chiesl, Thomas N.; Lowenstein, Tim K.; Amashukeli, Xenia; Grunthaner, Frank; Mathies, Richard A.

    2009-11-01

    The Mars Organic Analyzer (MOA) has enabled the sensitive detection of amino acid and amine biomarkers in laboratory standards and in a variety of field sample tests. However, the MOA is challenged when samples are extremely acidic and saline or contain polyvalent cations. Here, we have optimized the MOA analysis, sample labeling, and sample dilution buffers to handle such challenging samples more robustly. Higher ionic strength buffer systems with pKa values near pH 9 were developed to provide better buffering capacity and salt tolerance. The addition of ethylaminediaminetetraacetic acid (EDTA) ameliorates the negative effects of multivalent cations. The optimized protocol utilizes a 75 mM borate buffer (pH 9.5) for Pacific Blue labeling of amines and amino acids. After labeling, 50 mM (final concentration) EDTA is added to samples containing divalent cations to ameliorate their effects. This optimized protocol was used to successfully analyze amino acids in a saturated brine sample from Saline Valley, California, and a subcritical water extract of a highly acidic sample from the Río Tinto, Spain. This work expands the analytical capabilities of the MOA and increases its sensitivity and robustness for samples from extraterrestrial environments that may exhibit pH and salt extremes as well as metal ions.

  14. Capillary electrophoresis analysis of organic amines and amino acids in saline and acidic samples using the Mars organic analyzer.

    PubMed

    Stockton, Amanda M; Chiesl, Thomas N; Lowenstein, Tim K; Amashukeli, Xenia; Grunthaner, Frank; Mathies, Richard A

    2009-11-01

    The Mars Organic Analyzer (MOA) has enabled the sensitive detection of amino acid and amine biomarkers in laboratory standards and in a variety of field sample tests. However, the MOA is challenged when samples are extremely acidic and saline or contain polyvalent cations. Here, we have optimized the MOA analysis, sample labeling, and sample dilution buffers to handle such challenging samples more robustly. Higher ionic strength buffer systems with pK(a) values near pH 9 were developed to provide better buffering capacity and salt tolerance. The addition of ethylaminediaminetetraacetic acid (EDTA) ameliorates the negative effects of multivalent cations. The optimized protocol utilizes a 75 mM borate buffer (pH 9.5) for Pacific Blue labeling of amines and amino acids. After labeling, 50 mM (final concentration) EDTA is added to samples containing divalent cations to ameliorate their effects. This optimized protocol was used to successfully analyze amino acids in a saturated brine sample from Saline Valley, California, and a subcritical water extract of a highly acidic sample from the Río Tinto, Spain. This work expands the analytical capabilities of the MOA and increases its sensitivity and robustness for samples from extraterrestrial environments that may exhibit pH and salt extremes as well as metal ions.

  15. Organic acid mediated repression of sugar utilization in rhizobia.

    PubMed

    Iyer, Bhagya; Rajput, Mahendrapal Singh; Jog, Rahul; Joshi, Ekta; Bharwad, Krishna; Rajkumar, Shalini

    2016-11-01

    Rhizobia are a class of symbiotic diazotrophic bacteria which utilize C4 acids in preference to sugars and the sugar utilization is repressed as long as C4 acids are present. This can be manifested as a diauxie when rhizobia are grown in the presence of a sugar and a C4 acid together. Succinate, a C4 acid is known to repress utilization of sugars, sugar alcohols, hydrocarbons, etc by a mechanism termed as Succinate Mediated Catabolite Repression (SMCR). Mechanism of catabolite repression determines the hierarchy of carbon source utilization in bacteria. Though the mechanism of catabolite repression has been well studied in model organisms like E. coli, B. subtilis and Pseudomonas sp., mechanism of SMCR in rhizobia has not been well elucidated. C4 acid uptake is important for effective symbioses while mutation in the sugar transport and utilization genes does not affect symbioses. Deletion of hpr and sma0113 resulted in the partial relief of SMCR of utilization of galactosides like lactose, raffinose and maltose in the presence of succinate. However, no such regulators governing SMCR of glucoside utilization have been identified till date. Though rhizobia can utilize multitude of sugars, high affinity transporters for many sugars are yet to be identified. Identifying high affinity sugar transporters and studying the mechanism of catabolite repression in rhizobia is important to understand the level of regulation of SMCR and the key regulators involved in SMCR.

  16. Acetic acid-induced programmed cell death and release of volatile organic compounds in Chlamydomonas reinhardtii.

    PubMed

    Zuo, Zhaojiang; Zhu, Yerong; Bai, Yanling; Wang, Yong

    2012-02-01

    Acetic acid widely spreads in atmosphere, aquatic ecosystems containing residues and anoxic soil. It can inhibit aquatic plant germination and growth, and even cause programmed cell death (PCD) of yeast. In the present study, biochemical and physiological responses of the model unicellular green algae Chlamydomonas reinhardtii were examined after acetic acid stress. H(2)O(2) burst was found in C. reinhardtii after acetic acid stress at pH 5.0 for 10 min. The photosynthetic pigments were degraded, gross photosynthesis and respiration were disappeared gradually, and DNA fragmentation was also detected. Those results indicated that C. reinhardtii cells underwent a PCD but not a necrotic, accidental cell death event. It was noticed that C. reinhardtii cells in PCD released abundant volatile organic compounds (VOCs) upon acetic acid stress. Therefore, we analyzed the VOCs and tested their effects on other normal cells. The treatment of C. reinhardtii cultures with VOCs reduced the cell density and increased antioxidant enzyme activity. Therefore, a function of VOCs as infochemicals involved in cell-to-cell communication at the conditions of applied stress is suggested.

  17. Reversible Acid Gas Capture Using CO2-Binding Organic Liquids

    SciTech Connect

    Heldebrant, David J.; Koech, Phillip K.; Yonker, Clement R.; Rainbolt, James E.; Zheng, Feng

    2010-08-31

    Acid gas scrubbing technology is predominantly aqueous alkanolamine based. Of the acid gases, CO2, H2S and SO2 have been shown to be reversible, however there are serious disadvantages with corrosion and high regeneration costs. The primary scrubbing system composed of monoethanolamine is limited to 30% by weight because of the highly corrosive solution. This gravimetric limitation limits the CO2 volumetric (≤108 g/L) and gravimetric capacity (≤7 wt%) of the system. Furthermore the scrubbing system has a large energy penalty from pumping and heating the excess water required to dissolve the MEA bicarbonate salt. Considering the high specific heat of water (4 j/g-1K-1), low capacities and the high corrosion we set out to design a fully organic solvent that can chemically bind all acid gases i.e. CO2 as reversible alkylcarbonate ionic liquids or analogues thereof. Having a liquid acid gas carrier improves process economics because there is no need for excess solvent to pump and to heat. We have demonstrated illustrated in Figure 1, that CO2-binding organic liquids (CO2BOLs) have a high CO2 solubility paired with a much lower specific heat (<1.5 J/g-1K-1) than aqueous systems. CO2BOLs are a subsection of a larger class of materials known as Binding Organic Liquids (BOLs). Our BOLs have been shown to reversibly bind and release COS, CS2, and SO2, which we denote COSBOLS, CS2BOLs and SO2BOLs. Our BOLs are highly tunable and can be designed for post or pre-combustion gas capture. The design and testing of the next generation zwitterionic CO2BOLs and SO2BOLs are presented.

  18. Organic acids make Escherichia coli more resistant to pulsed electric fields at acid pH.

    PubMed

    Somolinos, M; García, D; Mañas, P; Condón, S; Pagán, R

    2010-01-01

    Stationary growth phase cells of Escherichiacoli were more pulsed electric fields (PEF) resistant in citrate-phosphate McIlvaine buffer at pH 4.0 than at pH 7.0. The greater PEF resistance was also confirmed in fruit juices of similar acid pH. In this work we studied whether the higher PEF resistance of E. coli at acid pH was due to the low pH itself or to the interaction of the components of the treatment medium with the cells. The protective effect on E. coli cells was due to the presence of organic acids such as citric, acetic, lactic or malic at pH 4.0. The protective effect of citric acid at pH 4.0 depended on its concentration. A linear relationship was observed between the Log(10) of the citric acid concentration and the degree of inactivation. Organic acids contained in laboratory treatment media (citrate-phosphate buffer) or in fruit juices did not sensitize E. coli cells to PEF but, on the contrary, they induced a protective effect that made E. coli cells more resistant at pH 4.0 than at neutral pH. This work could be useful for improving food preservation by PEF technology and it contributes to the knowledge of the mechanism of microbial inactivation by PEF.

  19. Modelling malic acid accumulation in fruits: relationships with organic acids, potassium, and temperature.

    PubMed

    Lobit, Philippe; Genard, Michel; Soing, Patrick; Habib, Robert

    2006-01-01

    Malic acid production, degradation, and storage during fruit development have been modelled. The model assumes that malic acid content is determined essentially by the conditions of its storage in the mesocarp cells, and provides a simplified representation of the mechanisms involved in the accumulation of malate in the vacuole and their regulation by thermodynamic constraints. Solving the corresponding system of equations made it possible to predict the malic acid content of the fruit as a function of organic acids, potassium concentration, and temperature. The model was applied to peach fruit, and parameters were estimated from the data of fruit development monitored over 2 years. The predictions were in good agreement with experimental data. Simulations were performed to analyse the behaviour of the model in response to variations in composition and temperature.

  20. Proton-binding study of standard and reference fulvic acids, humic acids, and natural organic matter

    NASA Astrophysics Data System (ADS)

    Ritchie, Jason D.; Perdue, E. Michael

    2003-01-01

    The acid-base properties of 14 standard and reference materials from the International Humic Substances Society (IHSS) were investigated by potentiometric titration. Titrations were conducted in 0.1 M NaCl under a nitrogen atmosphere, averaging 30 min from start to finish. Concentrations of carboxyl groups and phenolic groups were estimated directly from titration curves. Titration data were also fit to a modified Henderson-Hasselbalch model for two classes of proton-binding sites to obtain "best fit" parameters that describe proton-binding curves for the samples. The model was chosen for its simplicity, its ease of implementation in computer spreadsheets, and its excellent ability to describe the shapes of the titration curves. The carboxyl contents of the IHSS samples are in the general order: terrestrial fulvic acids > aquatic fulvic acids > Suwannee River natural organic matter (NOM) > aquatic humic acids > terrestrial humic acids. Overall, fulvic acids and humic acids have similar phenolic contents; however, all of the aquatically derived samples have higher phenolic contents than the terrestrially derived samples. The acid-base properties of reference Suwannee River NOM are surprisingly similar to those of standard Suwannee River humic acid. Results from titrations in this study were compared with other published results from both direct and indirect titrations. Typically, carboxyl contents for the IHSS samples were in agreement with the results from both methods of titration. Phenolic contents for the IHSS samples were comparable to those determined by direct titrations, but were significantly less than estimates of phenolic content that were based on indirect titrations with Ba(OH) 2 and Ca(OAc) 2. The average phenolic-to-carboxylic ratio of the IHSS samples is approximately 1:4. Models that assume a 1:2 ratio of phenolic-to-carboxylic groups may overestimate the relative contribution of phenolic groups to the acid-base chemistry of humic substances.

  1. Nickel deficiency disrupts metabolism of ureides, amino acids, and organic acids of young pecan foliage.

    PubMed

    Bai, Cheng; Reilly, Charles C; Wood, Bruce W

    2006-02-01

    The existence of nickel (Ni) deficiency is becoming increasingly apparent in crops, especially for ureide-transporting woody perennials, but its physiological role is poorly understood. We evaluated the concentrations of ureides, amino acids, and organic acids in photosynthetic foliar tissue from Ni-sufficient (Ni-S) versus Ni-deficient (Ni-D) pecan (Carya illinoinensis [Wangenh.] K. Koch). Foliage of Ni-D pecan seedlings exhibited metabolic disruption of nitrogen metabolism via ureide catabolism, amino acid metabolism, and ornithine cycle intermediates. Disruption of ureide catabolism in Ni-D foliage resulted in accumulation of xanthine, allantoic acid, ureidoglycolate, and citrulline, but total ureides, urea concentration, and urease activity were reduced. Disruption of amino acid metabolism in Ni-D foliage resulted in accumulation of glycine, valine, isoleucine, tyrosine, tryptophan, arginine, and total free amino acids, and lower concentrations of histidine and glutamic acid. Ni deficiency also disrupted the citric acid cycle, the second stage of respiration, where Ni-D foliage contained very low levels of citrate compared to Ni-S foliage. Disruption of carbon metabolism was also via accumulation of lactic and oxalic acids. The results indicate that mouse-ear, a key morphological symptom, is likely linked to the toxic accumulation of oxalic and lactic acids in the rapidly growing tips and margins of leaflets. Our results support the role of Ni as an essential plant nutrient element. The magnitude of metabolic disruption exhibited in Ni-D pecan is evidence of the existence of unidentified physiological roles for Ni in pecan.

  2. Organic Acids as Hetrotrophic Energy Sources in Hydrothermal Systems

    NASA Astrophysics Data System (ADS)

    Windman, T. O.; Zolotova, N.; Shock, E.

    2004-12-01

    Many thermophilic microbes are heterotrophs, but little is known about the organic compounds present in hydrothermal ecosystems. More is known about what these organisms will metabolize in lab experiments than what they do metabolize in nature. In an effort to bridge this gap, we have begun to incorporate organic analyses into ongoing research on Yellowstone hydrothermal ecosystems. After filtering at least a liter of hot spring water to minimize contamination, samples were collected into sixty-milliliter serum vials containing ultra-pure phosphoric acid, sodium hydroxide, or benzalkonium chloride. Approximately 80 sites were sampled spanning temperatures from 60 to 90°C and pH values from 2 to 9. Analytical data for organic acid anions (including formate, acetate, lactate, and succinate) were obtained by ion chromatography. Preliminary results indicate that concentrations of organic acids anions range from 5 to 300 ppb. These results can be used with other field and lab data (sulfate, sulfide, nitrate, ammonia, bicarbonate, pH, hydrogen) in thermodynamic calculations to evaluate the amounts of energy available in heterotrophic reactions. Preliminary results of such calculations show that sulfate reduction to sulfide coupled to succinate oxidation to bicarbonate yields about 6 kcal per mole of electrons transferred. When formate oxidation to bicarbonate or hydrogen oxidation to water is coupled to sulfate reduction there is less energy available by approximately a factor of two. A comparison with nitrate reduction to ammonia involving succinate and/or formate oxidation reveals several similarities. Using formate to reduce nitrate can yield about as much energy as nitrate reduction with hydrogen (typically 12 to 14 kcal per mole of electrons transferred), but using succinate can yield more than twice as much energy. In fact, reduction of nitrate with succinate can provide more energy than any of the inorganic nitrate reduction reactions involving sulfur, iron

  3. Abundance of volatile and organic species in intermediate temperature fluids from the Von Damm and Piccard deep sea hydrothermal fields, Mid-Cayman Rise

    NASA Astrophysics Data System (ADS)

    McDermott, J. M.; Seewald, J.; Reeves, E. P.; German, C. R.; Sylva, S. P.; Klein, F.

    2012-12-01

    Two recently discovered submarine hydrothermal systems at the ultra-slow spreading Mid-Cayman Rise provide a unique opportunity to investigate how mixing and cooling influence hydrothermal fluid chemistry at the deepest-yet discovered, basalt-hosted Piccard vent field (4960m) and at the Von Damm vent field (2300m), postulated to be ultramafic-hosted. Vent fluids were collected in January 2012 during R/V Atlantis cruise AT18-16 with gas-tight samplers deployed by the ROV Jason II, allowing the characterization and quantification of redox-reactive volatile species and organic compounds. Von Damm vent fluids ranged in temperature from 21 to 226°C, whereas Piccard fluids ranged from 45 to 398°C. A key feature of these systems is the variety of fluids that were actively venting from the seafloor at 100 to 200°C, substantially cooler than the hottest fluids observed at either site. The lower temperatures reflect subsurface seawater mixing and/or conductive heat loss. Fluids venting within this temperature range have rarely been sampled at other systems, and the Cayman fluids thus present an excellent opportunity to study the effect of cooling and mixing processes on enriched volatile species such as H2, H2S, CO2 and CH4. Three dominant processes are thought to affect volatile and organic species in intermediate temperature fluids. These include microbial consumption or production, thermal alteration of biomass, and abiotic reactions. The effect of these processes on fluid compositions carries implications for carbon utilization and metabolic activity of modern microbial populations hosted within hydrothermal mineral deposits and ascending plumes, carbon cycling within hydrothermal systems, and net geochemical fluxes to the ocean. Endmember CO2 concentrations at Von Damm range from slightly enriched relative to seawater in the highest temperature fluids, to measurably depleted in the cooler fluids. Such CO2 depletions have not been previously observed in other acidic

  4. Field enhancement sample stacking for analysis of organic acids in traditional Chinese medicine by capillary electrophoresis.

    PubMed

    Zhu, Qianqian; Xu, Xueqin; Huang, Yuanyuan; Xu, Liangjun; Chen, Guonan

    2012-07-13

    A technique known as field enhancement sample stacking (FESS) and capillary electrophoresis (CE) separation has been developed to analyze and detect organic acids in the three traditional Chinese medicines (such as Portulaca oleracea L., Crataegus pinnatifida and Aloe vera L.). In FESS, a reverse electrode polarity-stacking mode (REPSM) was applied as on-line preconcentration strategy. Under the optimized condition, the baseline separation of eight organic acids (linolenic acid, lauric acid, p-coumaric acid, ascorbic acid, benzoic acid, caffeic acid, succinic acid and fumaric acid) could be achieved within 20 min. Validation parameters of this method (such as detection limits, linearity and precision) were also evaluated. The detection limits ranged from 0.4 to 60 ng/mL. The results indicated that the proposed method was effective for the separation of mixtures of organic acids. Satisfactory recoveries were also obtained in the analysis of these organic acids in the above traditional Chinese medicine samples.

  5. Crystal and molecular structure of eight organic acid-base adducts from 2-methylquinoline and different acids

    NASA Astrophysics Data System (ADS)

    Zhang, Jing; Jin, Shouwen; Tao, Lin; Liu, Bin; Wang, Daqi

    2014-08-01

    Eight supramolecular complexes with 2-methylquinoline and acidic components as 4-aminobenzoic acid, 2-aminobenzoic acid, salicylic acid, 5-chlorosalicylic acid, 3,5-dinitrosalicylic acid, malic acid, sebacic acid, and 1,5-naphthalenedisulfonic acid were synthesized and characterized by X-ray crystallography, IR, mp, and elemental analysis. All of the complexes are organic salts except compound 2. All supramolecular architectures of 1-8 involve extensive classical hydrogen bonds as well as other noncovalent interactions. The results presented herein indicate that the strength and directionality of the classical hydrogen bonds (ionic or neutral) between acidic components and 2-methylquinoline are sufficient to bring about the formation of binary organic acid-base adducts. The role of weak and strong noncovalent interactions in the crystal packing is ascertained. These weak interactions combined, the complexes 1-8 displayed 2D-3D framework structure.

  6. DC diaphragm discharge in water solutions of selected organic acids

    NASA Astrophysics Data System (ADS)

    Vyhnankova, Edita J.; Hammer, Malte U.; Reuter, Stephan; Krcma, Frantisek

    2015-07-01

    Effect of four simple organic acids water solution on a DC diaphragm discharge was studied. Efficiency of the discharge was quantified by the hydrogen peroxide production determined by UV-VIS spectrometry of a H2O2 complex formed with specific titanium reagent. Automatic titration was used to study the pH behaviour after the plasma treatment. Optical emission spectroscopy overview spectra were recorded and detailed spectra of OH band and Hβ line were used to calculate the rotational temperature and comparison of the line profile (reflecting electron concentration) in the acid solutions. Contribution to the topical issue "The 14th International Symposium on High Pressure Low Temperature Plasma Chemistry (HAKONE XIV)", edited by Nicolas Gherardi, Ronny Brandenburg and Lars Stollenwark

  7. Control of Meloidogyne incognita Using Mixtures of Organic Acids

    PubMed Central

    Seo, Yunhee; Kim, Young Ho

    2014-01-01

    This study sought to control the root-knot nematode (RKN) Meloidogyne incognita using benign organo-chemicals. Second-stage juveniles (J2) of RKN were exposed to dilutions (1.0%, 0.5%, 0.2%, and 0.1%) of acetic acid (AA), lactic acid (LA), and their mixtures (MX). The nematode bodies were disrupted severely and moderately by vacuolations in 0.5% of MX and single organic acids, respectively, suggesting toxicity of MX may be higher than AA and LA. The mortality of J2 was 100% at all concentrations of AA and MX and only at 1.0% and 0.5% of LA, which lowered slightly at 0.2% and greatly at 0.1% of LA. This suggests the nematicidal activity of MX may be mostly derived from AA together with supplementary LA toxicity. MX was applied to chili pepper plants inoculated with about 1,000 J2, for which root-knot gall formations and plant growths were examined 4 weeks after inoculation. The root gall formation was completely inhibited by 0.5% MX and standard and double concentrations of fosthiazate; and inhibited 92.9% and 57.1% by 0.2% and 0.1% MX, respectively. Shoot height, shoot weight, and root weight were not significantly (P ≤ 0.05) different among all treatments and the untreated and non-inoculated controls. All of these results suggest that the mixture of the organic acids may have a potential to be developed as an eco-friendly nematode control agent that needs to be supported by the more nematode control experiments in fields. PMID:25506312

  8. Simple method of isolating humic acids from organic soils

    NASA Astrophysics Data System (ADS)

    Ahmed, O.

    2009-04-01

    Humic substances particularly humic acids (HA) play a major role in soil conditioning e.g. erosion control, soil cation exchange capacity, complexation of heavy metal ions and pesticides, carbon and nitrogen cycles, plant growth and reduction of ammonia volatilization from urea. Humified substances such as coal, composts, and peat soils have substantial amounts of HA but the isolation of these acids is expensive, laborious, and time consuming. Factors that affect the quality and yield of HA isolated from these materials include extraction, fractionation, and purification periods. This work developed a simple, rapid, and cost effective method of isolating HA from peat soils. There was a quadratic relationship between extraction period and HA yield. Optimum extraction period was estimated at 4 h instead of the usual range of 12 to 48 h. There was no relationship between fractionation period and HA yield. As such 2 h instead of the usual range of 12 to 24 h fractionation period could be considered optimum. Low ash content (5%), remarkable reduction in K, coupled with the fact that organic C, E4/E6, carboxylic COOH, phenolic OH, and total acidity values of the HA were consistent with those reported by other authors suggest that the HA dealt with were free from mineral matter. This was possible because the distilled water used to purify the HA served as Bronsted-Lowry acid during the purification process of the HA. Optimum purification period using distilled waster was 1 h instead of the usual range of 1 and 7 days (uses HF and HCl and dialysis). Humic acids could be isolated from tropical peat soils within 7 h (i.e. 4 h extraction, 2 h fractionation, and 1 h purification) instead of the existing period of 2 and 7 days. This could facilitate the idea of producing organic fertilizers such as ammonium-humate and potassium-humate from humified substances since techniques devised in this study did not alter the true nature of the HA. Besides, the technique is rapid, simple

  9. 40 CFR 747.195 - Triethanolamine salt of a substituted organic acid.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... organic acid. 747.195 Section 747.195 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Substances § 747.195 Triethanolamine salt of a substituted organic acid. This section identifies activities... subject to this section: P-84-310, triethanolamine salt of a substituted organic acid. (b)...

  10. 40 CFR 721.5465 - Amine salt of organic acid (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Amine salt of organic acid (generic... Substances § 721.5465 Amine salt of organic acid (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as amine salt of organic acid...

  11. 40 CFR 747.195 - Triethanolamine salt of a substituted organic acid.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... organic acid. 747.195 Section 747.195 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Substances § 747.195 Triethanolamine salt of a substituted organic acid. This section identifies activities... subject to this section: P-84-310, triethanolamine salt of a substituted organic acid. (b)...

  12. 40 CFR 721.5465 - Amine salt of organic acid (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Amine salt of organic acid (generic... Substances § 721.5465 Amine salt of organic acid (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as amine salt of organic acid...

  13. 40 CFR 747.195 - Triethanolamine salt of a substituted organic acid.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... organic acid. 747.195 Section 747.195 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Substances § 747.195 Triethanolamine salt of a substituted organic acid. This section identifies activities... subject to this section: P-84-310, triethanolamine salt of a substituted organic acid. (b)...

  14. 40 CFR 721.5465 - Amine salt of organic acid (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Amine salt of organic acid (generic... Substances § 721.5465 Amine salt of organic acid (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as amine salt of organic acid...

  15. 40 CFR 747.195 - Triethanolamine salt of a substituted organic acid.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... organic acid. 747.195 Section 747.195 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Substances § 747.195 Triethanolamine salt of a substituted organic acid. This section identifies activities... subject to this section: P-84-310, triethanolamine salt of a substituted organic acid. (b)...

  16. 40 CFR 747.195 - Triethanolamine salt of a substituted organic acid.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... organic acid. 747.195 Section 747.195 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Substances § 747.195 Triethanolamine salt of a substituted organic acid. This section identifies activities... subject to this section: P-84-310, triethanolamine salt of a substituted organic acid. (b)...

  17. 40 CFR 721.5465 - Amine salt of organic acid (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Amine salt of organic acid (generic... Substances § 721.5465 Amine salt of organic acid (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as amine salt of organic acid...

  18. 40 CFR 721.5465 - Amine salt of organic acid (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Amine salt of organic acid (generic... Substances § 721.5465 Amine salt of organic acid (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as amine salt of organic acid...

  19. Determination of tertiary amines and salts of organic acids in acetic acid by catalytic thermometric titration.

    PubMed

    Vajgand, V J; Gaál, F F

    1967-03-01

    A new method of determination of tertiary amines and salts of organic adds in acetic acid solution, to which about 2 % of water and 8% acetic anhydride are added, is described. After the equivalence point, the excess of perchloric acid catalyses the exothermic reaction of water with acetic anhydride. The end-point is determined from the graph of temperature against volume of added titrant. If a slightly soluble compound is produced during the titration, the precision of the new method is superior to that of the potentiometric method.

  20. Milk phospholipids: Organic milk and milk rich in conjugated linoleic acid compared with conventional milk.

    PubMed

    Ferreiro, T; Gayoso, L; Rodríguez-Otero, J L

    2015-01-01

    CLA-rich milk production included linseed supplement and contained less maize meal than conventional rations and a greater proportion of unsaturated fatty acids and salts. The relative proportions of the phospholipids studied were similar in all 3 types of milk, descending in the order PE>(PC, SM)>PS>PI, with PC being slightly more abundant than SM in organic milk and vice versa in CLA-rich milk.

  1. Seasonal variations and source identification of selected organic acids associated with PM10 in the coastal area of Southeastern China

    NASA Astrophysics Data System (ADS)

    Wu, Shui-Ping; Schwab, James; Liu, Bi-Lian; Li, Tsung-Chang; Yuan, Chung-Shin

    2015-03-01

    PM10 aerosols from the coastal area of Southeastern China were collected from April 2010 to March 2011 and were measured for C2-C10 dicarboxylic acids, phthalic acids (Ph) and five fatty acids (palmitic, stearic, oleic, linoleic and elaidic acids). For all sites and seasons, molecular distributions of diacids were always characterized by a predominance of oxalic acid (C2), with a relative abundance of 68-87%, followed by malonic acid (C3) and by either succinic acid (C4) or phthalic acid (Ph). This observed molecular composition was different from that in Chinese megacities where Ph was significantly higher than C3 and C4 diacids, which was likely due to the less intensive traffic emissions in the coastal area. Seasonal means of total diacids ranged between 394 and 547 ng m- 3 at the coastal urban sites and between 163 and 245 ng m- 3 at off-island sites. These levels were much lower than those reported in Chinese megacities (668-1568 ng m- 3) and slightly lower than those in Jeju Island, Korea (464-744 ng m- 3) but higher than those in marine and continental background locations. In all seasons, saturated fatty acids were significantly higher than unsaturated fatty acids due to their greater photochemical stabilities in the atmosphere. Most organic acids showed higher levels in spring and winter and lower levels in summer and fall, which was likely due to the influence of transport and meteorology. The diagnostic ratios of malonic acid to succinic acid (C3/C4), adipic acid to azelaic acid (C6/C9) and phthalic acid to azelaic acid (Ph/C9) were significantly higher in summer than in winter. These diagnostic ratios in the sampled ambient aerosols were completely different from those in primary emissions, suggesting the importance of photochemical production - especially in summer. The diurnal variations of diacids and fatty acid as well as the diagnostic ratios are associated with higher solar radiation and anthropogenic activities during the daytime. Principal

  2. Abundance of volatile organic compounds in white ash phloem and emerald ash borer larval frass does not attract Tetrastichus planipennisi in a Y-tube olfactometer.

    PubMed

    Chen, Yigen; Ulyshen, Michael D; Poland, Therese M

    2016-10-01

    Many natural enemies employ plant- and/or herbivore-derived signals for host/prey location. The larval parasitoid Tetrastichus planipennisi Yang (Hymenoptera: Eulophidae) is 1 of 3 biocontrol agents currently being released in an effort to control the emerald ash borer (EAB), Agrilus planipennis Fairmaire (Coloeptera: Burprestidae) in North America. To enhance its efficiency, allelochemicals that attract it need to be assessed. In this study, ash phloem volatile organic compounds (VOCs) of black, green, and white ash, and EAB larval frass were compared. Foraging behavior of T. planipennisi females in response to VOCs of white ash or frass from EAB larvae feeding on white ash phloem was tested using a Y-tube olfactometer. Results indicated that the 3 ash species had similar VOC profiles. EAB larval frass generally contained greater levels of VOCs than phloem. Factor analysis indicated that the 11 VOCs could be broadly divided into 2 groups, with α-bisabolol, β-caryophyllene, (E)-2-hexenal, (Z)-3-hexenal, limonene, methyl benzoate, methyl indole-3-acetic acid, methyl jasmonate, methyl salicylate as the first group and the rest (i.e., methyl linoleate and methyl linolenate) as a second. Abundance of VOCs in white ash phloem tissue and frass, nevertheless, did not attract T. planipennisi females. The concealed feeding of EAB larvae might explain the selection for detectable and reliable virbrational signals, instead of undetectable and relatively unreliable VOC cues from phloem and frass, in short-range foraging by T. planipennisi. Alternatively, it is possible that T. planipennisi is not amenable to the Y-tube olfactometer assay employed.

  3. MIG1 Regulates Resistance of Candida albicans against the Fungistatic Effect of Weak Organic Acids

    PubMed Central

    Cottier, Fabien; Tan, Alrina Shin Min; Xu, Xiaoli; Wang, Yue

    2015-01-01

    Candida albicans is the leading cause of fungal infections; but it is also a member of the human microbiome, an ecosystem of thousands of microbial species potentially influencing the outcome of host-fungal interactions. Accordingly, antibacterial therapy raises the risk of candidiasis, yet the underlying mechanism is currently not fully understood. We hypothesize the existence of bacterial metabolites that normally control C. albicans growth and of fungal resistance mechanisms against these metabolites. Among the most abundant microbiota-derived metabolites found on human mucosal surfaces are weak organic acids (WOAs), such as acetic, propionic, butyric, and lactic acid. Here, we used quantitative growth assays to investigate the dose-dependent fungistatic properties of WOAs on C. albicans growth and found inhibition of growth to occur at physiologically relevant concentrations and pH values. This effect was conserved across distantly related fungal species both inside and outside the CTG clade. We next screened a library of transcription factor mutants and identified several genes required for the resistance of C. albicans to one or more WOAs. A single gene, MIG1, previously known for its role in glucose repression, conferred resistance against all four acids tested. Consistent with glucose being an upstream activator of Mig1p, the presence of this carbon source was required for WOA resistance in wild-type C. albicans. Conversely, a MIG1-complemented strain completely restored the glucose-dependent resistance against WOAs. We conclude that Mig1p plays a central role in orchestrating a transcriptional program to fight against the fungistatic effect of this class of highly abundant metabolites produced by the gastrointestinal tract microbiota. PMID:26297702

  4. Carbon-13 natural abundance signatures of long-chain fatty acids to determinate sediment origin: A case study in northeast Austria

    NASA Astrophysics Data System (ADS)

    Mabit, Lionel; Gibbs, Max; Meusburger, Katrin; Toloza, Arsenio; Resch, Christian; Klik, Andreas; Swales, Andrew; Alewell, Christine

    2016-04-01

    - Several recently published information from scientific research have highlighted that compound-specific stable isotope (CSSI) signatures of fatty acids (FAs) based on the measurement of carbon-13 natural abundance signatures showed great promises to identify sediment origin. The authors have used this innovative isotopic approach to investigate the sources of sediment in a three hectares Austrian sub-watershed (i.e. Mistelbach). Through a previous study using the Cs-137 technique, Mabit et al. (Geoderma, 2009) reported a local maximum sedimentation rate reaching 20 to 50 t/ha/yr in the lowest part of this watershed. However, this study did not identify the sources. Subsequently, the deposited sediment at its outlet (i.e. the sediment mixture) and representative soil samples from the four main agricultural fields - expected to be the source soils - of the site were investigated. The bulk delta carbon-13 of the samples and two long-chain FAs (i.e. C22:0 and C24:0) allowed the best statistical discrimination. Using two different mixing models (i.e. IsoSource and CSSIAR v1.00) and the organic carbon content of the soil sources and sediment mixture, the contribution of each source has been established. Results suggested that the grassed waterway contributed to at least 50% of the sediment deposited at the watershed outlet. This study, that will require further validation, highlights that CSSI and Cs-137 techniques are complementary as fingerprints and tracers for establishing land sediment redistribution and could provide meaningful information for optimized decision-making by land managers.

  5. Aluminium Uptake and Translocation in Al Hyperaccumulator Rumex obtusifolius Is Affected by Low-Molecular-Weight Organic Acids Content and Soil pH

    PubMed Central

    Vondráčková, Stanislava; Száková, Jiřina; Drábek, Ondřej; Tejnecký, Václav; Hejcman, Michal; Müllerová, Vladimíra; Tlustoš, Pavel

    2015-01-01

    Background and Aims High Al resistance of Rumex obtusifolius together with its ability to accumulate Al has never been studied in weakly acidic conditions (pH > 5.8) and is not sufficiently described in real soil conditions. The potential elucidation of the role of organic acids in plant can explain the Al tolerance mechanism. Methods We established a pot experiment with R. obtusifolius planted in slightly acidic and alkaline soils. For the manipulation of Al availability, both soils were untreated and treated by lime and superphosphate. We determined mobile Al concentrations in soils and concentrations of Al and organic acids in organs. Results Al availability correlated positively to the extraction of organic acids (citric acid < oxalic acid) in soils. Monovalent Al cations were the most abundant mobile Al forms with positive charge in soils. Liming and superphosphate application were ambiguous measures for changing Al mobility in soils. Elevated transport of total Al from belowground organs into leaves was recorded in both lime-treated soils and in superphosphate-treated alkaline soil as a result of sufficient amount of Ca available from soil solution as well as from superphosphate that can probably modify distribution of total Al in R. obtusifolius as a representative of “oxalate plants.” The highest concentrations of Al and organic acids were recorded in the leaves, followed by the stem and belowground organ infusions. Conclusions In alkaline soil, R. obtusifolius is an Al-hyperaccumulator with the highest concentrations of oxalate in leaves, of malate in stems, and of citrate in belowground organs. These organic acids form strong complexes with Al that can play a key role in internal Al tolerance but the used methods did not allow us to distinguish the proportion of total Al-organic complexes to the free organic acids. PMID:25880431

  6. A laboratory evaluation of the sorption of oil sands naphthenic acids on organic rich soils.

    PubMed

    Janfada, Arash; Headley, John V; Peru, Kerry M; Barbour, S L

    2006-01-01

    The adsorption characteristics of oil sands tailings pond water (OSTPW)-derived naphthenic acids on soils was determined using a batch partitioning method. The adsorption isotherms were found to be linear in all cases. All tests were conducted at 4 degrees C, and at a pH of 8.0 +/- 0.4, which reflects the pH of a tailings settling facility near Fort McMurray, AB. The adsorption characteristics of the naphthenic acids in a synthetic groundwater (SGW) solution was compared to that of the mixture in Milli-Q water. In the presence of SGW, the adsorption coefficient (K(d)) of the mixture of naphthenic acids on soil 1 with a higher organic carbon fraction (f(oc)) was an order of magnitude higher than that observed with the same soil and the Milli-Q water mixture, increasing from 1.9 +/- 0.2 (mL/g) to 17.8 +/- 1.5 (mL/g). The adsorption coefficient of the mixture of naphthenic acids on soil 2, with a lower f(oc), was also observably higher in the SGW mixture, increasing from 1.3 +/- 0.15 (mL/g) to 3.7 +/- 0.2 (mL/g). The relative fractional abundance of the individual naphthenic acids was plotted in order to determine the presence of preferential sorption between individual species within the mixture. It was found that for all Z families (where Z is a measure of the number of rings), naphthenic acids within the carbon number range of 13 to 17 showed preferential sorption. The mixture in SGW showed more pronounced sorption relative to naphthenic acid mixture in Milli-Q water. The results indicate that mixtures of naphthenic acids sorb strongly to soils and that adsorption would be an important attenuating mechanism in groundwater transport. Furthermore, preferential sorption of the individual naphthenic acids is important from a toxicity stand point since different naphthenic acid species have varying degrees of toxicity.

  7. N-15 NMR spectra of naturally abundant nitrogen in soil and aquatic natural organic matter samples of the International Humic Substances Society

    USGS Publications Warehouse

    Thorn, K.A.; Cox, L.G.

    2009-01-01

    The naturally abundant nitrogen in soil and aquatic NOM samples from the International Humic Substances Society has been characterized by solid state CP/MAS 15N NMR. Soil samples include humic and fulvic acids from the Elliot soil, Minnesota Waskish peat and Florida Pahokee peat, as well as the Summit Hill soil humic acid and the Leonardite humic acid. Aquatic samples include Suwannee River humic, fulvic and reverse osmosis isolates, Nordic humic and fulvic acids and Pony Lake fulvic acid. Additionally, Nordic and Suwannee River XAD-4 acids and Suwannee River hydrophobic neutral fractions were analyzed. Similar to literature reports, amide/aminoquinone nitrogens comprised the major peaks in the solid state spectra of the soil humic and fulvic acids, along with heterocyclic and amino sugar/terminal amino acid nitrogens. Spectra of aquatic samples, including the XAD-4 acids, contain resolved heterocyclic nitrogen peaks in addition to the amide nitrogens. The spectrum of the nitrogen enriched, microbially derived Pony Lake, Antarctica fulvic acid, appeared to contain resonances in the region of pyrazine, imine and/or pyridine nitrogens, which have not been observed previously in soil or aquatic humic substances by 15N NMR. Liquid state 15N NMR experiments were also recorded on the Elliot soil humic acid and Pony Lake fulvic acid, both to examine the feasibility of the techniques, and to determine whether improvements in resolution over the solid state could be realized. For both samples, polarization transfer (DEPT) and indirect detection (1H-15N gHSQC) spectra revealed greater resolution among nitrogens directly bonded to protons. The amide/aminoquinone nitrogens could also be observed by direct detection experiments.

  8. N-15 NMR spectra of naturally abundant nitrogen in soil and aquatic natural organic matter samples of the International Humic Substances Society

    SciTech Connect

    Thorn, Kevin A.; Cox, Larry G.

    2009-02-28

    The naturally abundant nitrogen in soil and aquatic NOM samples from the International Humic Substances Society has been characterized by solid state CP/MAS ¹⁵N NMR. Soil samples include humic and fulvic acids from the Elliot soil, Minnesota Waskish peat and Florida Pahokee peat, as well as the Summit Hill soil humic acid and the Leonardite humic acid. Aquatic samples include Suwannee River humic, fulvic and reverse osmosis isolates, Nordic humic and fulvic acids and Pony Lake fulvic acid. Additionally, Nordic and Suwannee River XAD-4 acids and Suwannee River hydrophobic neutral fractions were analyzed. Similar to literature reports, amide/aminoquinone nitrogens comprised the major peaks in the solid state spectra of the soil humic and fulvic acids, along with heterocyclic and amino sugar/terminal amino acid nitrogens. Spectra of aquatic samples, including the XAD-4 acids, contain resolved heterocyclic nitrogen peaks in addition to the amide nitrogens. The spectrum of the nitrogen enriched, microbially derived Pony Lake, Antarctica fulvic acid, appeared to contain resonances in the region of pyrazine, imine and/or pyridine nitrogens, which have not been observed previously in soil or aquatic humic substances by ¹⁵N NMR. Liquid state ¹⁵N NMR experiments were also recorded on the Elliot soil humic acid and Pony Lake fulvic acid, both to examine the feasibility of the techniques, and to determine whether improvements in resolution over the solid state could be realized. For both samples, polarization transfer (DEPT) and indirect detection (¹H–¹⁵N gHSQC) spectra revealed greater resolution among nitrogens directly bonded to protons. The amide/aminoquinone nitrogens could also be observed by direct detection experiments.

  9. Enhanced proton conductivity of Nafion composite membrane by incorporating phosphoric acid-loaded covalent organic framework

    NASA Astrophysics Data System (ADS)

    Yin, Yongheng; Li, Zhen; Yang, Xin; Cao, Li; Wang, Chongbin; Zhang, Bei; Wu, Hong; Jiang, Zhongyi

    2016-11-01

    Design and fabrication of efficient proton transport channels within solid electrolytes is crucial and challenging to new energy-relevant devices such as proton exchange membrane fuel cells (PEMFCs). In this study, the phosphoric acid (H3PO4) molecules are impregnated into SNW-1-type covalent organic frameworks (COFs) via vacuum assisted method. High loading of H3PO4 in SNW-1 and low guest leaching rate are achieved due to the similar diameter between H3PO4 and micropores in SNW-1. Then the COF-based composite membranes are fabricated for the first time with impregnated COFs (H3PO4@SNW-1) and Nafion matrix. For the composite membranes, the acid-base pairs formed between H3PO4@SNW-1 networks and Nafion optimize the interfacial interactions and hydrophilic domains. The acidic -PO3H2 groups in pores of H3PO4@SNW-1 provide abundant proton transfer sites. As a result, the continuous proton transfer channels with low energy barrier are created. At the filler content of 15 wt%, the composite membrane exhibits a superior proton conductivity of 0.0604 S cm-1 at 51% relative humidity and 80 °C. At the same time, the maximum power density of single fuel cell is 60.3% higher than that of the recast Nafion membrane.

  10. The relationship of metals, bifenthrin, physical habitat metrics, grain size, total organic carbon, dissolved oxygen and conductivity to Hyalella sp. abundance in urban California streams.

    PubMed

    Hall, Lenwood W; Anderson, Ronald D

    2013-01-01

    The objectives of this study were to determine the relationship between Hyalella sp. abundance in four urban California streams and the following parameters: (1) 8 bulk metals (As, Cd, Cr, Cu, Pb, Hg, Ni, and Zn) and their associated sediment Threshold Effect Levels (TELs); (2) bifenthrin sediment concentrations; (3) 10 habitat metrics and total score; (4) grain size (% sand, silt and clay); (5) Total Organic Carbon (TOC); (6) dissolved oxygen; and (7) conductivity. California stream data used for this study were collected from Kirker Creek (2006 and 2007), Pleasant Grove Creek (2006, 2007 and 2008), Salinas streams (2009 and 2010) and Arcade Creek (2009 and 2010). Hyalella abundance in the four California streams generally declined when metals concentrations were elevated beyond the TELs. There was also a statistically significant negative relationship between Hyalella abundance and % silt for these 4 California streams as Hyalella were generally not present in silt areas. No statistically significant relationships were reported between Hyalella abundance and metals concentrations, bifenthrin concentrations, habitat metrics, % sand, % clay, TOC, dissolved oxygen and conductivity. The results from this study highlight the complexity of assessing which factors are responsible for determining the abundance of amphipods, such as Hyalella sp., in the natural environment.

  11. [Influences of long-term application of organic and inorganic fertilizers on the composition and abundance of nirS-type denitrifiers in black soil].

    PubMed

    Yin, Chang; Fan, Fen-Liang; Li, Zhao-Jun; Song, A-Lin; Zhu, Ping; Peng, Chang; Liang, Yong-Chao

    2012-11-01

    The objectives of this study were to explore the effects of long-term organic and inorganic fertilizations on the composition and abundance of nirS-type denitrifiers in black soil. Soil samples were collected from 4 treatments (i. e. no fertilizer treatment, CK; organic manure treatment, OM; chemical fertilizer treatment (NPK) and combination of organic and chemical fertilizers treatment (MNPK)) in Gongzhuling Long-term Fertilization Experiment Station. Composition and abundance of nirS-type denitrifiers were analyzed with terminal restriction fragment length polymorphism (T-RFLP) and real-time quantitative PCR (Q-PCR), respectively. Denitrification enzyme activity (DEA) and soil properties were also measured. Application of organic fertilizers (OM and MNPK) significantly increased the DEAs of black soil, with the DEAs in OM and MNPK being 5.92 and 6.03 times higher than that in CK treatment, respectively, whereas there was no significant difference between NPK and CK. OM and MNPK treatments increased the abundances of nirS-type denitrifiers by 2.73 and 3.83 times relative to that of CK treatment, respectively. The abundance of nirS-type denitrifiers in NPK treatment was not significantly different from that of CK. The T-RFLP analysis of nirS genes showed significant differences in community composition between organic and inorganic treatments, with the emergence of a 79 bp T-RF, a significant decrease in relative abundance of the 84 bp T-RF and a loss of the 99 bp T-RF in all organic treatments. Phylogenetic analysis indicated that the airS-type denitrifiers in the black soil were mainly composed of alpha, beta and gamma-Proteobacteria. The 79 bp-type denitrifiers inhabiting exclusively in organic treatments (OM and MNPK) were affiliated to Pseudomonadaceae in gamma-Proteobacteria and Burkholderiales in beta-Proteobacteria. The 84 bp-types were related to Burkholderiales and Rhodocyclales. Correlation analysis indicated that pH, concentrations of total nitrogen

  12. Gamma Peptide Nucleic Acids: As Orthogonal Nucleic Acid Recognition Codes for Organizing Molecular Self-Assembly.

    PubMed

    Sacui, Iulia; Hsieh, Wei-Che; Manna, Arunava; Sahu, Bichismita; Ly, Danith H

    2015-07-08

    Nucleic acids are an attractive platform for organizing molecular self-assembly because of their specific nucleobase interactions and defined length scale. Routinely employed in the organization and assembly of materials in vitro, however, they have rarely been exploited in vivo, due to the concerns for enzymatic degradation and cross-hybridization with the host's genetic materials. Herein we report the development of a tight-binding, orthogonal, synthetically versatile, and informationally interfaced nucleic acid platform for programming molecular interactions, with implications for in vivo molecular assembly and computing. The system consists of three molecular entities: the right-handed and left-handed conformers and a nonhelical domain. The first two are orthogonal to each other in recognition, while the third is capable of binding to both, providing a means for interfacing the two conformers as well as the natural nucleic acid biopolymers (i.e., DNA and RNA). The three molecular entities are prepared from the same monomeric chemical scaffold, with the exception of the stereochemistry or lack thereof at the γ-backbone that determines if the corresponding oligo adopts a right-handed or left-handed helix, or a nonhelical motif. These conformers hybridize to each other with exquisite affinity, sequence selectivity, and level of orthogonality. Recognition modules as short as five nucleotides in length are capable of organizing molecular assembly.

  13. Organic acids in cloud water and rainwater at a mountain site in acid rain areas of South China.

    PubMed

    Sun, Xiao; Wang, Yan; Li, Haiyan; Yang, Xueqiao; Sun, Lei; Wang, Xinfeng; Wang, Tao; Wang, Wenxing

    2016-05-01

    To investigate the chemical characteristics of organic acids and to identify their source, cloud water and rainwater samples were collected at Mount Lu, a mountain site located in the acid rain-affected area of south China, from August to September of 2011 and March to May of 2012. The volume-weighted mean (VWM) concentration of organic acids in cloud water was 38.42 μeq/L, ranging from 7.45 to 111.46 μeq/L, contributing to 2.50 % of acidity. In rainwater samples, organic acid concentrations varied from 12.39 to 68.97 μeq/L (VWM of 33.39 μeq/L). Organic acids contributed significant acidity to rainwater, with a value of 17.66 %. Formic acid, acetic acid, and oxalic acid were the most common organic acids in both cloud water and rainwater. Organic acids had an obviously higher concentration in summer than in spring in cloud water, whereas there was much less discrimination in rainwater between the two seasons. The contribution of organic acids to acidity was lower during summer than during spring in both cloud water (2.20 % in summer vs 2.83 % in spring) and rainwater (12.24 % in summer vs 19.89 % in spring). The formic-to-acetic acid ratio (F/A) showed that organic acids were dominated by primary emissions in 71.31 % of the cloud water samples and whole rainwater samples. Positive matrix factorization (PMF) analysis determined four factors as the sources of organic acids in cloud water, including biogenic emissions (61.8 %), anthropogenic emissions (15.28 %), marine emissions (15.07 %) and soil emissions (7.85 %). The findings from this study imply an indispensable role of organic acids in wet deposition, but organic acids may have a limited capacity to increase ecological risks in local environments.

  14. Characterization of a flood-associated deposit on the Waipaoa River shelf using radioisotopes and terrigenous organic matter abundance and composition

    NASA Astrophysics Data System (ADS)

    Kniskern, Tara A.; Mitra, Siddhartha; Orpin, Alan R.; Harris, Courtney K.; Walsh, J. P.; Corbett, D. R.

    2014-09-01

    An ephemeral oceanic-flood deposit adjacent to a well-studied small mountainous river (SMR), the Waipaoa River in northeastern New Zealand, was characterized using multiple proxies, including radioisotopes (234Th, 7Be, and 210Pb), bulk organic carbon abundance and isotopic signature (%OC, δ13C), as well as a biomarker of terrigenous organic matter (lignin). Field sampling was conducted within two weeks after a 1-in-8 year flood that occurred between January 30 and February 6, 2010. Geochemical analyses indicated that initial deposition of fresh riverine material extended alongshore to the north and south from the river mouth. A comparison of prior- and post-flood 7Be inventories revealed that flood sediments were widely dispersed between 20 and 70 m water depth, accounting for 50-80% of the estimated flood load. Surface (0-2 cm) isotopic carbon values increased with distance from Poverty Bay, positively correlating with total 210Pb activities, potentially reflecting increasing marine influence with water depth. Abundances of sedimentary organic carbon (OC) were 0.18-0.76% dry weight, and the total nitrogen varied from 0.02 to 0.13%. Stable isotope signatures of carbon (δ13COC), nitrogen (δ15N), and lignin abundances (λ6) throughout the study area ranged from -23.6 to -27.7‰, 1.9 to 5.3‰, and 0.93 to 9.0 mg 100 mg OC-1, respectively. The spatial distribution pattern of terrigenous organic matter (OM) abundance and interclass ratios (indicative of freshness of organic matter) varied along and across-shelf. Lignin abundances were high and interclass ratios were low in the southern depocenter and inner shelf areas, suggesting that this zone had recently received vascular-plant enriched OM, minimally altered by shelf-bed mixing processes. In contrast, sediments in the northern depocenter and outer shelf also contained elevated amounts of terrigenous sedimentary OM, but this material was generally lower in lignin abundance and had higher interclass ratios

  15. HPLC method for the simultaneous quantification of the major organic acids in Angeleno plum fruit

    NASA Astrophysics Data System (ADS)

    Wang, Yanwei; Wang, Jing; Cheng, Wei; Zhao, Zhilei; Cao, Jiankang

    2014-08-01

    A method was developed to profile major organic acids in Angeleno fruit by high performance liquid chromatography. Organic acids in plum were extracted by water with ultra- sonication at 50°C for 30 min. The extracts were chromatographed on Waters Atlantis T3 C18 column (4.6 mm×250 mm, 5 μm) with 0.01mol/L sulfuric acid and water as mobile phase, and flow rate was 0.5 ml/min. The column temperature was 40C, and chromatography was monitored by a diode array detector at 210 nm. The result showed that malic acid, citric acid, tartaric acid, oxalic acid, pyruvic acid, acetic acid, succinic acid in Angeleno plum, and the malic acid was the major organic acids. The coefficient of determination of the standard calibration curve is R2 > 0.999. The organic acids recovery ranged from 99.11% for Malic acid to 106.70% for Oxalic acid, and CV (n=6) ranged from 0.95% for Malic acid to 6.23% for Oxalic acid, respectively. The method was accurate, sensitive and feasible in analyzing the organic acids in Angeleno plum.

  16. Sonolysis of Short-Chain Organic Dicarboxylic Acid Solutions

    NASA Astrophysics Data System (ADS)

    Naruke, Yukio; Harada, Hisashi

    2011-07-01

    Sonolyses of C4 (carbon number 4) dicarboxylic acids (succinic acid, maleic acid, and fumaric acid) were performed in aqueous solution. They changed one into the other during sonication, affording carbon-number-conserving transformations. Maleic acid and fumaric acid were produced from saccinic acid by dehydrogenation. Furthermore, malic acid and tartaric acid were obtained by hydroxylation. The sonochemical reaction processes are discussed in terms of the time dependences of products and the addition of radical scavengers. In addition, mutual isomerization of fumaric acid and maleic acid was observed during sonication without the use of mediators.

  17. Terpenylic and Related Lactone-Containing Acids: Novel Monoterpene Secondary Organic Aerosol Tracers with Dimer-Forming Properties

    NASA Astrophysics Data System (ADS)

    Claeys, M.; Iinuma, Y.; Szmigielski, R.; Farhat, Y.; Surratt, J. D.; Blockhuys, F.; van Alsenoy, C.; Böge, O.; Sierau, B.; Gómez-González, Y.; Vermeylen, R.; van der Veken, P.; Shahgholi, M.; Chan, A. W.; Herrmann, H.; Seinfeld, J.; Maenhaut, W.

    2009-12-01

    Blue haze is a natural phenomenon that is observed in forested regions worldwide and is due to the formation of secondary organic aerosol (SOA) particles. While evidence exists for organic molecular clusters in the size range of < 2 nm, the chemical structures of the nucleating particles have remained unresolved. In the present study, novel SOA products from the monoterpene α-pinene with unique dimer-forming properties have been identified as lactone-containing terpenoic acids, i.e., terpenylic (molecular weight (MW) 172), terebic (MW 158) and 2-hydroxyterpenylic acid (MW 188), and diaterpenylic acid acetate (MW 232). The structural characterizations were based on synthesis of reference compounds and detailed interpretation of negative ion electrospray ionization mass spectral [(-)ESI-MS] data, including accurate mass and MSn ion trap measurements. Terpenylic acid and diaterpenylic acid acetate are early oxidation products formed upon both photooxidation and ozonolysis, and are abundant SOA tracers in ambient fine aerosol from coniferous forest sites (e.g., K-puszta, Hungary). Terebic and 2-hydroxyterpenylic acid can be explained by further oxidation of terpenylic acid, and are also prominent tracers in ambient fine aerosol. Quantum chemical calculations support that non-covalent dimer formation involving double hydrogen bonding interactions between carboxyl groups of the monomers is energetically favorable. Lactone-containing terpenoic acids also form through photooxidation from monoterpenes other than α-pinene, i.e., terebic acid from Δ3-carene, and terpenylic, homoterpenylic (MW 186), and terebic acid from β-pinene. A distinct feature of terpenylic acid and related lactone-containing acids is that they can be selectively detected in positive ion (+)ESI-MS, unlike isobaric dicarboxylic terpenoic acids such as norpinic (MW 172) and pinic acid (MW 186). Interestingly, terpenylic, terebic and homoterpenylic acid were already reported in the early German

  18. Strong anion exchange liquid chromatographic separation of protein amino acids for natural 13C-abundance determination by isotope ratio mass spectrometry.

    PubMed

    Abaye, Daniel A; Morrison, Douglas J; Preston, Tom

    2011-02-15

    Amino acids are the building blocks of proteins and the analysis of their (13)C abundances is greatly simplified by the use of liquid chromatography (LC) systems coupled with isotope ratio mass spectrometry (IRMS) compared with gas chromatography (GC)-based methods. To date, various cation exchange chromatography columns have been employed for amino acid separation. Here, we report strong anion exchange chromatography (SAX) coupled to IRMS with a Liquiface interface for amino acid δ(13)C determination. Mixtures of underivatised amino acids (0.1-0.5 mM) and hydrolysates of representative proteins (prawns and bovine serum albumin) were resolved by LC/IRMS using a SAX column and inorganic eluents. Background inorganic carbon content was minimised through careful preparation of alkaline reagents and use of a pre-injector on-line carbonate removal device. SAX chromatography completely resolved 11 of the 16 expected protein amino acids following acid hydrolysis in underivatised form. Basic and neutral amino acids were resolved with 35 mM NaOH in isocratic mode. Elution of the aromatic and acidic amino acids required a higher hydroxide concentration (180 mM) and a counterion (NO 3-, 5-25 mM). The total run time was 70 min. The average δ(13)C precision of baseline-resolved peaks was 0.75‰ (range 0.04 to 1.06‰). SAX is a viable alternative to cation chromatography, especially where analysis of basic amino acids is important. The technology shows promise for (13)C amino acid analysis in ecology, archaeology, forensic science, nutrition and protein metabolism.

  19. Carbohydrate, Organic Acid, and Amino Acid Composition of Bacteroids and Cytosol from Soybean Nodules 1

    PubMed Central

    Streeter, John G.

    1987-01-01

    Metabolites in Bradyrhizobium japonicum bacteroids and in Glycine max (L.) Merr. cytosol from root nodules were analyzed using an isolation technique which makes it possible to estimate and correct for changes in concentration which may occur during bacteroid isolation. Bacteroid and cytosol extracts were fractionated on ion-exchange columns and were analyzed for carbohydrate composition using gas-liquid chromatography and for organic acid and amino acid composition using high performance liquid chromatography. Analysis of organic acids in plant tissues as the phenacyl derivatives is reported for the first time and this approach revealed the presence of several unknown organic acids in nodules. The time required for separation of bacteroids and cytosol was varied, and significant change in concentration of individual compounds during the separation of the two fractions was estimated by calculating the regression of concentration on time. When a statistically significant slope was found, the true concentration was estimated by extrapolating the regression line to time zero. Of 78 concentration estimates made, there was a statistically significant (5% level) change in concentration during sample preparation for only five metabolites: glucose, sucrose, and succinate in the cytosol and d-pinitol and serine in bacteroids. On a mass basis, the major compounds in bacteroids were (descending order of concentration): myo-inositol, d-chiro-inositol, α,α-trehalose, sucrose, aspartate, glutamate, d-pinitol, arginine, malonate, and glucose. On a proportional basis (concentration in bacteroid as percent of concentration in bacteroid + cytosol fractions), the major compounds were: α-aminoadipate (94), trehalose (66), lysine (58), and arginine (46). The results indicate that metabolite concentrations in bacteroids can be reliably determined. PMID:16665774

  20. Recoded organisms engineered to depend on synthetic amino acids.

    PubMed

    Rovner, Alexis J; Haimovich, Adrian D; Katz, Spencer R; Li, Zhe; Grome, Michael W; Gassaway, Brandon M; Amiram, Miriam; Patel, Jaymin R; Gallagher, Ryan R; Rinehart, Jesse; Isaacs, Farren J

    2015-02-05

    Genetically modified organisms (GMOs) are increasingly used in research and industrial systems to produce high-value pharmaceuticals, fuels and chemicals. Genetic isolation and intrinsic biocontainment would provide essential biosafety measures to secure these closed systems and enable safe applications of GMOs in open systems, which include bioremediation and probiotics. Although safeguards have been designed to control cell growth by essential gene regulation, inducible toxin switches and engineered auxotrophies, these approaches are compromised by cross-feeding of essential metabolites, leaked expression of essential genes, or genetic mutations. Here we describe the construction of a series of genomically recoded organisms (GROs) whose growth is restricted by the expression of multiple essential genes that depend on exogenously supplied synthetic amino acids (sAAs). We introduced a Methanocaldococcus jannaschii tRNA:aminoacyl-tRNA synthetase pair into the chromosome of a GRO derived from Escherichia coli that lacks all TAG codons and release factor 1, endowing this organism with the orthogonal translational components to convert TAG into a dedicated sense codon for sAAs. Using multiplex automated genome engineering, we introduced in-frame TAG codons into 22 essential genes, linking their expression to the incorporation of synthetic phenylalanine-derived amino acids. Of the 60 sAA-dependent variants isolated, a notable strain harbouring three TAG codons in conserved functional residues of MurG, DnaA and SerS and containing targeted tRNA deletions maintained robust growth and exhibited undetectable escape frequencies upon culturing ∼10(11) cells on solid media for 7 days or in liquid media for 20 days. This is a significant improvement over existing biocontainment approaches. We constructed synthetic auxotrophs dependent on sAAs that were not rescued by cross-feeding in environmental growth assays. These auxotrophic GROs possess alternative genetic codes that

  1. Recoded organisms engineered to depend on synthetic amino acids

    PubMed Central

    Rovner, Alexis J.; Haimovich, Adrian D.; Katz, Spencer R.; Li, Zhe; Grome, Michael W.; Gassaway, Brandon M.; Amiram, Miriam; Patel, Jaymin R.; Gallagher, Ryan R.; Rinehart, Jesse; Isaacs, Farren J.

    2015-01-01

    Genetically modified organisms (GMOs) are increasingly used in research and industrial systems to produce high-value pharmaceuticals, fuels, and chemicals1. Genetic isolation and intrinsic biocontainment would provide essential biosafety measures to secure these closed systems and enable safe applications of GMOs in open systems2,3, which include bioremediation4 and probiotics5. Although safeguards have been designed to control cell growth by essential gene regulation6, inducible toxin switches7, and engineered auxotrophies8, these approaches are compromised by cross-feeding of essential metabolites, leaked expression of essential genes, or genetic mutations9,10. Here, we describe the construction of a series of genomically recoded organisms (GROs)11 whose growth is restricted by the expression of multiple essential genes that depend on exogenously supplied synthetic amino acids (sAAs). We introduced a Methanocaldococcus jannaschii tRNA:aminoacyl-tRNA synthetase (aaRS) pair into the chromosome of a GRO that lacks all TAG codons and release factor 1, endowing this organism with the orthogonal translational components to convert TAG into a dedicated sense codon for sAAs. Using multiplex automated genome engineering (MAGE)12, we introduced in-frame TAG codons into 22 essential genes, linking their expression to the incorporation of synthetic phenylalanine-derived amino acids. Of the 60 sAA-dependent variants isolated, a notable strain harboring 3 TAG codons in conserved functional residues13 of MurG, DnaA and SerS and containing targeted tRNA deletions maintained robust growth and exhibited undetectable escape frequencies upon culturing ∼1011 cells on solid media for seven days or in liquid media for 20 days. This is a significant improvement over existing biocontainment approaches2,3,6-10. We constructed synthetic auxotrophs dependent on sAAs that were not rescued by cross-feeding in environmental growth assays. These auxotrophic GROs possess alternate genetic

  2. The effect of particle acidity on secondary organic aerosol formation from α-pinene photooxidation under atmospherically relevant conditions

    NASA Astrophysics Data System (ADS)

    Han, Yuemei; Stroud, Craig A.; Liggio, John; Li, Shao-Meng

    2016-11-01

    Secondary organic aerosol (SOA) formation from photooxidation of α-pinene has been investigated in a photochemical reaction chamber under varied inorganic seed particle acidity levels at moderate relative humidity. The effect of particle acidity on SOA yield and chemical composition was examined under high- and low-NOx conditions. The SOA yield (4.2-7.6 %) increased nearly linearly with the increase in particle acidity under high-NOx conditions. In contrast, the SOA yield (28.6-36.3 %) was substantially higher under low-NOx conditions, but its dependency on particle acidity was insignificant. A relatively strong increase in SOA yield (up to 220 %) was observed in the first hour of α-pinene photooxidation under high-NOx conditions, suggesting that SOA formation was more effective for early α-pinene oxidation products in the presence of fresh acidic particles. The SOA yield decreased gradually with the increase in organic mass in the initial stage (approximately 0-1 h) under high-NOx conditions, which is likely due to the inaccessibility to the acidity over time with the coating of α-pinene SOA, assuming a slow particle-phase diffusion of organic molecules into the inorganic seeds. The formation of later-generation SOA was enhanced by particle acidity even under low-NOx conditions when introducing acidic seed particles after α-pinene photooxidation, suggesting a different acidity effect exists for α-pinene SOA derived from later oxidation stages. This effect could be important in the atmosphere under conditions where α-pinene oxidation products in the gas-phase originating in forested areas (with low NOx and SOx) are transported to regions abundant in acidic aerosols such as power plant plumes or urban regions. The fraction of oxygen-containing organic fragments (CxHyO1+ 33-35 % and CxHyO2+ 16-17 %) in the total organics and the O / C ratio (0.52-0.56) of α-pinene SOA were lower under high-NOx conditions than those under low-NOx conditions (39-40, 17-19, and

  3. Long-term variations in abundance and distribution of sulfuric acid vapor in the Venus atmosphere inferred from Pioneer Venus and Magellan radio occultation studies

    NASA Technical Reports Server (NTRS)

    Jenkins, J. M.; Steffes, P. G.

    1992-01-01

    Radio occultation experiments have been used to study various properties of planetary atmospheres, including pressure and temperature profiles, and the abundance profiles of absorbing constituents in those planetary atmospheres. However, the reduction of amplitude data from such experiments to determine abundance profiles requires the application of the inverse Abel transform (IAT) and numerical differentiation of experimental data. These two operations preferentially amplify measurement errors above the true signal underlying the data. A new technique for processing radio occultation data has been developed that greatly reduces the errors in the derived absorptivity and abundance profiles. This technique has been applied to datasets acquired from Pioneer Venus Orbiter radio occultation studies and more recently to experiments conducted with the Magellan spacecraft. While primarily designed for radar studies of the Venus surface, the high radiated power (EIRP) from the Magellan spacecraft makes it an ideal transmitter for measuring the refractivity and absorptivity of the Venus atmosphere by such experiments. The longevity of the Pioneer Venus Orbiter has made it possible to study long-term changes in the abundance and distribution of sulfuric acid vapor, H2SO4(g), in the Venus atmosphere between 1979 and 1992. The abundance of H2SO4(g) can be inferred from vertical profiles of 13-cm absorptivity profiles retrieved from radio occultation experiments. Data from 1979 and 1986-87 suggest that the abundance of H2SO4(g) at latitudes northward of 70 deg decreased over this time period. This change may be due to a period of active volcanism in the late 1970s followed by a relative quiescent period, or some other dynamic process in the Venus atmosphere. While the cause is not certain, such changes must be incorporated into dynamic models of the Venus atmosphere. Potentially, the Magellan spacecraft will extend the results of Pioneer Venus Orbiter and allow the continued

  4. Combined impact of pH and organic acids on iron uptake by Caco-2 cells.

    PubMed

    Salovaara, Susan; Sandberg, Ann-Sofie; Andlid, Thomas

    2003-12-17

    Previous studies have shown that organic acids have an impact on both Fe(II) and Fe(III) uptake in Caco-2 cell. However, to what extent this effect is correlated with the anion of organic acids per se, or with the resulting decrease in pH, has not yet been clarified. Therefore, we studied the effect of five organic acids (tartaric, succinic, citric, oxalic, and propionic acid) on the absorption of Fe(II) and Fe(III) in Caco-2 cells and compared this with sample solutions without organic acids but set to equivalent pH by HCl. The results showed that the mechanisms behind the enhancing effect of organic acids differed for the two forms of iron. For ferric iron the organic acids promoted uptake both by chelation and by lowering the pH, whereas for ferrous iron the promoting effect was caused only by the lowered pH.

  5. Use of Cavity Ring Down Spectroscopy to Characterize Organic Acids and Aerosols Emitted in Biomass Burning

    NASA Astrophysics Data System (ADS)

    Bililign, Solomon; Fiddler, Marc; Singh, Sujeeta

    2012-02-01

    One poorly understood, but significant class of volatile organic compounds (VOC) present in biomass burning is gas-phase organic acids and inorganic acids. These acids are extremely difficult to measure because of their adsorptive nature. Particulates and aerosols are also produced during biomass burning and impact the radiation budget of the Earth and, hence, impact global climate. Use cavity ring down spectroscopy (CRD) to measure absorption cross sections for OH overtone induced photochemistry in some organic acids (acetic acid and peracetic acid) will be presented and planed measurements of optical properties of aerosols composed of mixtures of different absorbing and non-absorbing species using CRD will be discussed.

  6. Amino Acids Hydrolyzed from Animal Carcasses Are a Good Additive for the Production of Bio-organic Fertilizer.

    PubMed

    Liu, Hongjun; Chen, Dandan; Zhang, Ruifu; Hang, Xinnan; Li, Rong; Shen, Qirong

    2016-01-01

    High-quality bio-organic fertilizers (BIOs) cannot be produced without the addition of some proteins. In this study, compound liquid amino acids (CLAA) from animal carcasses were utilized as additives into matured composts to create novel BIOs containing plant growth-promoting rhizobacteria (PGPR). The results showed that adding CLAA and inoculating bacteria meanwhile resulted in failed solid-state fermentation (SSF) due to the higher H(+) contents. While after pre-compost for 4 days before PGPR inoculation, treatments of matured chicken or pig manure added with 0.2 ml g(-1) of CLAA resulted in a maximum biomass of functional strains. Illumine-MiSeq sequencing and Real-Time PCR results showed that the CLAA addition decreased the bacterial abundance and richness, altered the bacterial community structure and changed the relative abundance of some microbial groups. This study offers a high value-added utilization of waste protein resources for producing economical, high-quality BIO.

  7. Water-enhanced solubility of carboxylic acids in organic solvents and its applications to extraction processes

    SciTech Connect

    Starr, J.N.; King, C.J.

    1991-11-01

    The solubilities of carboxylic acids in certain organic solvents increase remarkably with an increasing amount of water in the organic phase. This phenomenon leads to a novel extract regeneration process in which the co-extracted water is selectively removed from an extract, and the carboxylic acid precipitates. This approach is potentially advantageous compared to other regeneration processes because it removes a minor component of the extract in order to achieve a large recovery of acid from the extract. Carboxylic acids of interest include adipic acid, fumaric acid, and succinic acid because of their low to moderate solubilities in organic solvents. Solvents were screened for an increase in acid solubility with increased water concentration in the organic phase. Most Lewis-base solvents were found to exhibit this increased solubility phenomena. Solvents that have a carbonyl functional group showed a very large increase in acid solubility. 71 refs., 52 figs., 38 tabs.

  8. Isolation of organic acids from large volumes of water by adsorption chromatography

    USGS Publications Warehouse

    Aiken, George R.

    1984-01-01

    The concentrations of dissolved organic carbon from most natural waters ranges from 1 to 20 milligrams carbon per liter, of which approximately 75 percent are organic acids. These acids can be chromatographically fractionated into hydrophobic organic acids, such as humic substances, and hydrophilic organic acids. To effectively study any of these organic acids, they must be isolated from other organic and inorganic species, and concentrated. Usually, large volumes of water must be processed to obtain sufficient quantities of material, and adsorption chromatography on synthetic, macroporous resins has proven to be a particularly effective method for this purpose. The use of the nonionic Amberlite XAD-8 and Amberlite XAD-4 resins and the anion exchange resin Duolite A-7 for isolating and concentrating organic acids from water is presented.

  9. Effects of pH adjustment and sodium ions on sour taste intensity of organic acids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Protonated organic acid species have been shown to be the primary stimuli responsible for sour taste of organic acids. However, we have observed that sour taste may be modulated when the pH of acid solutions is raised using sodium hydroxide. Objectives were to evaluate the effect of pH adjustment on...

  10. Single-step analysis of low abundance phosphoamino acids via on-line sample preconcentration with chemical derivatization by capillary electrophoresis.

    PubMed

    Ptolemy, Adam S; Britz-McKibbin, Philip

    2005-09-01

    New strategies for rapid, sensitive and high-throughput analysis of low abundance metabolites in biological samples are required for future metabolomic research. In this report, a direct method for sub-micromolar analyses of phosphoamino acids was developed using on-line sample preconcentration with 9-fluorenylmethyloxycarbonyl chloride (FMOC) derivatization by capillary electrophoresis (CE) and UV detection. Analyte focusing by dynamic pH junction and FMOC labeling efficiency were influenced by several experimental factors including buffer pH, ionic strength, sample injection length and FMOC concentration. About a 200-fold enhancement in concentration sensitivity was achieved under optimal conditions relative to conventional off-line derivatization, as reflected by a detection limit (S/N approximately 3) of 0.1 microM. In-capillary sample preconcentration with chemical labeling by CE offers a unique single-step analytical platform for high-throughput screening of low abundance metabolites without intrinsic chromophores.

  11. Inorganic and organic fertilizers impact the abundance and proportion of antibiotic resistance and integron-integrase genes in agricultural grassland soil.

    PubMed

    Nõlvak, Hiie; Truu, Marika; Kanger, Kärt; Tampere, Mailiis; Espenberg, Mikk; Loit, Evelin; Raave, Henn; Truu, Jaak

    2016-08-15

    Soil fertilization with animal manure or its digestate may facilitate an important antibiotic resistance dissemination route from anthropogenic sources to the environment. This study examines the effect of mineral fertilizer (NH4NO3), cattle slurry and cattle slurry digestate amendment on the abundance and proportion dynamics of five antibiotic resistance genes (ARGs) and two classes of integron-integrase genes (intI1 and intI2) in agricultural grassland soil. Fertilization was performed thrice throughout one vegetation period. The targeted ARGs (sul1, tetA, blaCTX-M, blaOXA2 and qnrS) encode resistance to several major antibiotic classes used in veterinary medicine such as sulfonamides, tetracycline, cephalosporins, penicillin and fluoroquinolones, respectively. The non-fertilized grassland soil contained a stable background of tetA, blaCTX-M and sul1 genes. The type of applied fertilizer significantly affected ARGs and integron-integrase genes abundances and proportions in the bacterial community (p<0.001 in both cases), explaining 67.04% of the abundance and 42.95% of the proportion variations in the grassland soil. Both cattle slurry and cattle slurry digestate proved to be considerable sources of ARGs, especially sul1, as well as integron-integrases. Sul1, intI1 and intI2 levels in grassland soil were elevated in response to each organic fertilizer's application event, but this increase was followed by a stage of decrease, suggesting that microbes possessing these genes were predominantly entrained into soil via cattle slurry or its digestate application and had somewhat limited survival potential in a soil environment. However, the abundance of these three target genes did not decrease to a background level by the end of the study period. TetA was most abundant in mineral fertilizer treated soil and blaCTX-M in cattle slurry digestate amended soil. Despite significantly different abundances, the abundance dynamics of bacteria possessing these genes were

  12. Effects of organic and inorganic acids on phosphorus release from municipal sludge.

    PubMed

    Pakdil, N B; Filibeli, A

    2007-01-01

    This paper reports on the effects of inorganic acids (sulphuric acid, hydrochloric acid, nitric acid) and organic acids (citric acid, oxalic acids) for phosphorus recovery from sludge and struvite precipitation results. It was observed that both inorganic acid and organic acids were effective at phosphorus release. The studies on precipitation of released phosphorus from sludge as magnesium ammonium phosphate (struvite) were also done using nitric and oxalic acids. Phosphorus and heavy metals of leachate were analyzed before and after precipitation. It was observed that heavy metal concentrations in the extracted samples decrease after precipitation. Precipitation was accomplished by using extract derived with nitric acid; however, in oxalic acid applications, it was not achieved. When the chemical constituents of the dried material were examined oxygen, sodium and nitrogen were found to be the major elements.

  13. Mineralogy and Organic Geochemistry of Acid Sulfate Environments from Valles Caldera, New Mexico: Habitability, Weathering and Biosignatures

    NASA Astrophysics Data System (ADS)

    Vogel, M. B.; Des Marais, D. J.; Jahnke, L. L.; Kubo, M.

    2009-12-01

    carbonate minerals. Gypsum from Valles Caldera fumaroles develops in the absence of microbial biofilms and differs from biologically influenced marine gypsum in terms of is highly prismatic morphology, lack of texture, and association with clays, and other sulfates. Studies of Valles gypsum crystals therefore support the uniqueness of the putative morphological biosignatures in marine gypsum. We also assayed organic matter from fumarole encrustations to understand how low pH and sulfate content may discriminate against or enhance preservation of specific classes of organic compounds in acid sulfate environments. Similar to gypsiferous marine environments, organics are characterized by abundant organosulfur complexes. Long chain alkanes (> nC22) are abundant from acid sulfate environments. As with hypersaline marine depositional environments, sulfidation appears to be a major diagenetic pathway for organic matter in acid sulfate environments.

  14. [Effect of low molecular weight organic acids on inorganic phosphorus transformation in red soil and its acidity].

    PubMed

    Hu, Hongqing; Liao, Lixia; Wang, Xinglin

    2002-07-01

    Red soil samples collected from southern Hubei province and northern Jiangxi province were tested to analyze their inorganic phosphorus fractions, pH and active aluminum after incubated with added various organic acids. The results indicated that application of organic acids increased the content of Ca2-P in both red soils, in the order of citric acid > malic acid > succinic acid > acetic acid, did not affect the contents of Ca8-P and Ca10-P, but usually reduced Fe-P, Al-P and O-P. The pH values of the soils treated by organic acids, except for acetic acid, were reduced by 0.65-1.96, compared with the control. Soil active Al extracted with 0.02 mol.L-1 CaCl2 in treatments with citric, malic and succinic acid was 5.7-51.3 times as the control, and Al extracted with 1 mol.L-1 KCl also increased 4.0-67.3 times. However, acetic acid had little influence on active soil Al. It was concluded that in red soils, organic acid could improve phosphorus availability, but enhance the soil toxicity caused by active Al.

  15. Leaching of organic acids from macromolecular organic matter by non-supercritical CO2

    NASA Astrophysics Data System (ADS)

    Sauer, P.; Glombitza, C.; Kallmeyer, J.

    2012-04-01

    The storage of CO2 in underground reservoirs is discussed controversly in the scientific literature. The worldwide search for suitable storage formations also considers coal-bearing strata. CO2 is already injected into seams for enhanced recovery of coal bed methane. However, the effects of increased CO2 concentration, especially on organic matter rich formations, are rarely investigated. The injected CO2 will dissolve in the pore water, causing a decrease in pH and resulting in acidic formation waters. Huge amounts of low molecular weight organic acids (LMWOAs) are chemically bound to the macromolecular matrix of sedimentary organic matter and may be liberated by hydrolysis, which is enhanced by the acidic porewater. Recent investigations outlined the importance of LMWOAs as a feedstock for microbial life in the subsurface [1]. Therefore, injection of CO2 into coal formations may result in enhanced nutrient supply for subsurface microbes. To investigate the effect of high concentrations of dissolved CO2 on the release of LMWOAs from coal we developed an inexpensive high-pressure high temperature system that allows manipulating the partial pressure of dissolved gases at pressures and temperatures up to 60 MPa and 120° C, respectively. In a reservoir vessel, gases are added to saturate the extraction medium to the desired level. Inside the extraction vessel hangs a flexible and inert PVDF sleeve (polyvinylidene fluoride, almost impermeable for gases), holding the sample and separating it from the pressure fluid. The flexibility of the sleeve allows for subsampling without loss of pressure. Coal samples from the DEBITS-1 well, Waikato Basin, NZ (R0 = 0.29, TOC = 30%). were extracted at 90° C and 5 MPa, either with pure or CO2-saturated water. Subsamples were taken at different time points during the extraction. The extracted LMWOAs such as formate, acetate and oxalate were analysed by ion chromatography. Yields of LMWOAs were higher with pure water than with CO2

  16. Atmospheric oxalic acid and related secondary organic aerosols in Qinghai Lake, a continental background site in Tibet Plateau

    NASA Astrophysics Data System (ADS)

    Meng, Jingjing; Wang, Gehui; Li, Jianjun; Cheng, Chunlei; Cao, Junji

    2013-11-01

    Summertime PM2.5 aerosols collected from Qinghai Lake (3200 m a.s.l.), a remote continental site in the northeastern part of Tibetan Plateau, were analyzed for dicarboxylic acids (C2-C11), ketocarboxylic acids and α-dicarbonyals. Oxalic acid (C2) is the dominant dicarboxylic acid in the samples, followed by malonic, succinic and azelaic acids. Total dicarboxylic acids (231 ± 119 ng m-3), ketocarboxylic acids (8.4 ± 4.3 ng m-3), and α-dicarbonyls (2.7 ± 2.1 ng m-3) at the Tibetan background site are 2-5 times less than those detected in lowland areas such as 14 Chinese megacities. Compared to those in other urban and marine areas enhancements in relative abundances of C2/total diacids and diacids-C/WSOC of the PM2.5 samples suggest that organic aerosols in the region are more oxidized due to strong solar radiation. Molecular compositions and air mass trajectories demonstrate that the above secondary organic aerosols in the Qinghai Lake atmosphere are largely derived from long-range transport. Ratios of oxalic acid, glyoxal and methylglyoxal to levoglucosan in PM2.5 aerosols emitted from household burning of yak dung, a major energy source for Tibetan in the region, are 30-400 times lower than those in the ambient air, which further indicates that primary emission from biomass burning is a negligible source of atmospheric oxalic acid and α-dicarbonyls at this background site.

  17. Deletion of glucose oxidase changes the pattern of organic acid production in Aspergillus carbonarius

    PubMed Central

    2014-01-01

    Aspergillus carbonarius has potential as a cell factory for the production of different organic acids. At pH 5.5, A.carbonarius accumulates high amounts of gluconic acid when it grows on glucose based medium whereas at low pH, it produces citric acid. The conversion of glucose to gluconic acid is carried out by secretion of the enzyme, glucose oxidase. In this work, the gene encoding glucose oxidase was identified and deleted from A. carbonarius with the aim of changing the carbon flux towards other organic acids. The effect of genetic engineering was examined by testing glucose oxidase deficient (Δgox) mutants for the production of different organic acids in a defined production medium. The results obtained showed that the gluconic acid accumulation was completely inhibited and increased amounts of citric acid, oxalic acid and malic acid were observed in the Δgox mutants. PMID:25401063

  18. Uptake of Ambient Organic Gases to Acidic Sulfate Aerosols

    NASA Astrophysics Data System (ADS)

    Liggio, J.; Li, S.

    2009-05-01

    The formation of secondary organic aerosols (SOA) in the atmosphere has been an area of significant interest due to its climatic relevance, its effects on air quality and human health. Due largely to the underestimation of SOA by regional and global models, there has been an increasing number of studies focusing on alternate pathways leading to SOA. In this regard, recent work has shown that heterogeneous and liquid phase reactions, often leading to oligomeric material, may be a route to SOA via products of biogenic and anthropogenic origin. Although oligomer formation in chamber studies has been frequently observed, the applicability of these experiments to ambient conditions, and thus the overall importance of oligomerization reactions remain unclear. In the present study, ambient air is drawn into a Teflon smog chamber and exposed to acidic sulfate aerosols which have been formed in situ via the reaction of SO3 with water vapor. The aerosol composition is measured with a High Resolution Aerodyne Aerosol Mass Spectrometer (HR-ToF-AMS), and particle size distributions are monitored with a scanning mobility particle sizer (SMPS). The use of ambient air and relatively low inorganic particle loading potentially provides clearer insight into the importance of heterogeneous reactions. Results of experiments, with a range of sulfate loadings show that there are several competing processes occurring on different timescales. A significant uptake of ambient organic gases to the particles is observed immediately followed by a slow shift towards higher m/z over a period of several hours indicating that higher molecular weight products (possibly oligomers) are being formed through a reactive process. The results suggest that heterogeneous reactions can occur with ambient organic gases, even in the presence of ammonia, which may have significant implications to the ambient atmosphere where particles may be neutralized after their formation.

  19. 40 CFR 747.115 - Mixed mono and diamides of an organic acid.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Mixed mono and diamides of an organic... Substances § 747.115 Mixed mono and diamides of an organic acid. This section identifies activities with... subject to this section: P-84-529, mixed mono and diamides of an organic acid. (b)...

  20. 40 CFR 747.115 - Mixed mono and diamides of an organic acid.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Mixed mono and diamides of an organic... Substances § 747.115 Mixed mono and diamides of an organic acid. This section identifies activities with... subject to this section: P-84-529, mixed mono and diamides of an organic acid. (b)...

  1. 40 CFR 747.115 - Mixed mono and diamides of an organic acid.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Mixed mono and diamides of an organic... Substances § 747.115 Mixed mono and diamides of an organic acid. This section identifies activities with... subject to this section: P-84-529, mixed mono and diamides of an organic acid. (b)...

  2. 40 CFR 747.115 - Mixed mono and diamides of an organic acid.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Mixed mono and diamides of an organic... Substances § 747.115 Mixed mono and diamides of an organic acid. This section identifies activities with... subject to this section: P-84-529, mixed mono and diamides of an organic acid. (b)...

  3. Evaluation of organic acids as fuel cell electrolytes

    SciTech Connect

    Ahmad, J.; Nguyen, T.H.; Foley, R.T.

    1981-11-01

    The electrochemical behavior of methanesulfonic acid, ethanesulfonic acid, and sulfoacetic acid as fuel cell electrolytes was studied in half-cell at various temperatures. The rate of the electro-oxidation of hydrogen at 115/degree/C was very high in methanesulfonic acid. The rate of the electro-oxidation of propane in all three acids was low even at 135/degree/C. Further, there is evidence for adsorption of these acids on the platinum electrode. It is concluded that anhydrous sulfonic acids are not good electrolytes; water solutions are required. Sulfonic acids containing unprotected carbon-hydrogen bonds are adsorbed on platinum and probably decompose during electrolysis. 9 refs.

  4. Spatio-temporal distribution of organic and inorganic pollutants from Lake Geneva (Switzerland) reveals strong interacting effects of sewage treatment plant and eutrophication on microbial abundance.

    PubMed

    Thevenon, Florian; Graham, Neil D; Herbez, Aline; Wildi, Walter; Poté, John

    2011-07-01

    Variation with depth and time of organic matter (carbon, nitrogen, phosphorus), inorganic pollutant (mercury), as well as bacterial abundance and activity, were investigated for the first time in sediment profiles of different parts of Lake Geneva (Switzerland) over the last decades. The highest organic contents (about 32%), mercury concentration (27 mg kg(-1)), bacterial abundance (in order of 9×10(9) cell g(-1) dry sediment), and bacterial activity (1299 Relative Light Units (RLU)) were found in the highly polluted sediments contaminated by the waste water treatment plant (WWTP) discharge, which deposited during the period of cultural eutrophication. Such data, which contrast with the other sampled sites from deeper and more remote parts of the lake, prove that the organic matter and nutrients released from the municipal WWTP have considerable effects on bacterial abundance and activities in freshwater sediments. In fact, the relatively unpolluted deepwater sites and the coastal polluted site show large synchronous increases in bacterial densities linked to the anoxic conditions in the 1970s (lake eutrophication caused by external nutrient input) that subsequently increased the nutrient loading fluxes. These results show that the microbial activities response to natural or human-induced changing limnological conditions (e.g., nutrient supply, oxygen availability, redox conditions) constitutes a threat to the security of water resources, which in turn poses concerns for the world's freshwater resources in the context of global warming and the degradation of water quality (oxygen depletion in the bottom water due to reduced deep waters mixing). Moreover, the accumulation of inorganic pollutants such as high mercury (methyl-mercury) concentration may represent a significant source of toxicity for sediment dwelling organisms.

  5. Effect of ribonucleic acid (RNA) isolation methods on putative reference genes messenger RNA abundance in human spermatozoa.

    PubMed

    Barragán, M; Martínez, A; Llonch, S; Pujol, A; Vernaeve, V; Vassena, R

    2015-07-01

    Although the male gamete participates in a significant proportion of infertility cases, there are currently no proven molecular markers of sperm quality. The search for significant gene expression markers is partially hindered by the lack of a recognized set of reference genes (RGs) to normalize reverse transcription quantitative PCR (RT-qPCR) data across studies. The aim of this study is to define a set of RGs in assisted reproduction patients undergoing different sample collection and RNA isolation methods. Twenty-two normozoospermic men were included in the study. From each man, semen was either cryopreserved by slow freezing or analyzed fresh, and, for each, RNA was extracted with either phenol-free or phenol-based methods. In two cases, both methods were used to isolate RNA. Twenty putative RGs were analyzed and their mRNA abundance across samples was estimated by RT-qPCR. To determine the genes whose steady-state mRNA abundance remains unchanged, three different algorithms (geNorm, BestKeeper and NormFinder) were applied to the qPCR data. We found that RGs such as GAPDH or ACTB, useful in other biological contexts, cannot be used as reference for human spermatozoa. It is possible to compare gene expression from fresh and cryopreserved sperm samples using the same isolation method, while the mRNA abundance of expressed genes becomes different depending on the RNA isolation technique employed. In our conditions, the most appropriate RGs for RT-qPCR analysis were RPLP1, RPL13A, and RPLP2. Published discrepancies in gene expression studies in human spermatozoa may be due in part to inappropriate RGs selection, suggesting a possible different interpretation of PCR data in several reports, which were normalized using unstable RGs.

  6. Comparison of abundances, compositions and sources of elements, inorganic ions and organic compounds in atmospheric aerosols from Xi'an and New Delhi, two megacities in China and India.

    PubMed

    Li, Jianjun; Wang, Gehui; Aggarwal, Shankar G; Huang, Yao; Ren, Yanqin; Zhou, Bianhong; Singh, Khem; Gupta, Prabhat K; Cao, Junji; Zhang, Rong

    2014-04-01

    Wintertime TSP samples collected in the two megacities of Xi'an, China and New Delhi, India were analyzed for elements, inorganic ions, carbonaceous species and organic compounds to investigate the differences in chemical compositions and sources of organic aerosols. The current work is the first time comparing the composition of urban organic aerosols from China and India and discussing their sources in a single study. Our results showed that the concentrations of Ca, Fe, Ti, inorganic ions, EC, PAHs and hopanes in Xi'an are 1.3-2.9 times of those in New Delhi, which is ascribed to the higher emissions of dust and coal burning in Xi'an. In contrast, Cl(-), levoglucosan, n-alkanes, fatty alcohols, fatty acids, phthalates and bisphenol A are 0.4-3.0 times higher in New Delhi than in Xi'an, which is attributed to strong emissions from biomass burning and solid waste incineration. PAHs are carcinogenic while phthalates and bisphenol A are endocrine disrupting. Thus, the significant difference in chemical compositions of the above TSP samples may suggest that residents in Xi'an and New Delhi are exposed to environmental hazards that pose different health risks. Lower mass ratios of octadecenoic acid/octadecanoic acid (C18:1/C18:0) and benzo(a)pyrene/benzo(e)pyrene (BaP/BeP) demonstrate that aerosol particles in New Delhi are photochemically more aged. Mass closure reconstructions of the wintertime TSP indicate that crustal material is the most abundant component of ambient particles in Xi'an and New Delhi, accounting for 52% and 48% of the particle masses, respectively, followed by organic matter (24% and 23% in Xi'an and New Delhi, respectively) and secondary inorganic ions (sulfate, nitrate plus ammonium, 16% and 12% in Xi'an and New Delhi, respectively).

  7. Dynamics of three organic acids (malic, acetic and succinic acid) in sunflower exposed to cadmium and lead.

    PubMed

    Niu, Zhixin; Li, Xiaodong; Sun, Lina; Sun, Tieheng

    2013-01-01

    Sunflower (Helianthus annuus L.) has been considered as a good candidate for bioaccumulation of heavy metals. In the present study, sunflower was used to enrich the cadmium and lead in sand culture during 90 days. Biomass, Cd and Pb uptake, three organic acids and pH in cultures were investigated. Results showed that the existence of Cd and Pb showed different interactions on the organic acids exudation. In single Cd treatments, malic and acetic acids in Cd10 showed an incremental tendency with time. In the mixed treatments of Cd and Pb, malic acids increased when 10 and 40 mg x L(-1) Cd were added into Pb50, but acetic acids in Pb50 were inhibited by Cd addition. The Cd10 supplied in Pb10 stimulated the secretion of malic and succinic acids. Moreover, the Cd or Pb uptake in sunflower showed various correlations with pH and some organic acids, which might be due to the fact that the Cd and Pb interfere with the organic acids secretion in rhizosphere of sunflower, and the changes of organic acids altered the form and bioavailability of Cd and Pb in cultures conversely.

  8. Growth inhibition of Cronobacter spp. strains in reconstituted powdered infant formula acidified with organic acids supported by natural stomach acidity.

    PubMed

    Zhu, S; Schnell, S; Fischer, M

    2013-09-01

    Cronobacter is associated with outbreaks of rare, but life-threatening cases of meningitis, necrotizing enterocolitis, and sepsis in newborns. This study was conducted to determine the effect of organic acids on growth of Cronobacter in laboratory medium and reconstituted powdered infant formula (PIF) as well as the bacteriostatic effect of slightly acidified infant formula when combined with neonatal gastric acidity. Inhibitory effect of seven organic acids on four acid sensitive Cronobacter strains was determined in laboratory medium with broth dilution method at pH 5.0, 5.5 and 6.0. Acetic, butyric and propionic acids were most inhibitive against Cronobacter in the laboratory medium. The killing effect of these three acids was partially buffered in reconstituted PIF. Under neonatal gastric acid condition of pH 5.0, the slightly acidified formula which did not exert inhibition effect solely reduced significantly the Cronobacter populations. A synergistic effect of formula moderately acidified with organic acid combined with the physiological infant gastric acid was visible in preventing the rapid growth of Cronobacter in neonatal stomach. The study contributed to a better understanding of the inhibitory effect of organic acids on Cronobacter growth in different matrixes and provided new ideas in terms of controlling bacteria colonization and translocation by acidified formula.

  9. Anhydrosugar and sugar alcohol organic markers associated with carboxylic acids in particulate matter from incense burning

    NASA Astrophysics Data System (ADS)

    Tsai, Ying I.; Wu, Pei-Ling; Hsu, Yu-Ting; Yang, Chi-Ru

    2010-09-01

    Aerosol from the burning two types of sandalwood-based incense, Hsing Shan and Lao Shan, was analyzed to characterize the chemical profile of total particulate matter emitted. The total particulate matter (PM) mass emission factors were 46.3 ± 2.68 mg g -1 of Hsing Shan incense and 43.7 ± 1.08 mg g -1 of Lao Shan incense. Chemical analysis of emissions from the two types of incense revealed that of the 25 components in four groups characterized, anhydrosugars formed the major group, at 46.7-52.2% w/w of the identified particulate and 1078.3-1169.8 μg g -1 of incense, followed by inorganic salts at 30.4-31.8% w/w of identified particulate and 681.6-734.0 μg g -1 of incense, carboxylic acids at 12.0-17.1% w/w of the identified particulate and 268.6-392.8 μg g -1 of incense, and sugar alcohols at 4.44-5.38% w/w of the identified particulate and 102.3-120.6 μg g -1 of incense. More anhydrosugars and sugar alcohols were emitted from Lao Shan incense than from Hsing Shan incense whereas more carboxylic acids and organic salts were emitted from Hsing Shan than from Lao Shan. These differences were due to structural and functional differences in the young sandalwood used to make Hsing Shan and the aged sandalwood used to make Lao Shan. The anhydrosugar levoglucosan, used as a marker of biomass burning, was always the most abundant species in emitted PM for both incenses ( Lao Shan 21.7 mg g -1 of PM and Hsing Shan 18.7 mg g -1). K + and Cl - were the second most abundant components (K + and Cl - were summed), accounting for 10.6 mg g -1 of Hsing Shan PM and 9.85 mg g -1 of Lao Shan PM. The most abundant carboxylic acids in the emissions were formic, acetic, succinic, glutaric and phthalic acid. The latter is a fragrance ingredient and a potential health hazard and was twice as prevalent in Lao Shan emissions. Xylitol was the most prevalent of the sugar alcohols at 35.7-36.6% w/w of total identified sugar alcohols. These abundant species are potential markers for

  10. Sulfuric acid vapor and other cloud-related gases in the Venus atmosphere - Abundances inferred from observed radio opacity

    NASA Technical Reports Server (NTRS)

    Steffes, P. G.; Eshleman, V. R.

    1982-01-01

    It is suggested that the absorbing characteristics of sulfuric acid vapor appear to reconcile what had been thought to be an inconsistency among measurements and deductions regarding the constituents of the Venus atmosphere and radio occultation, radar reflection, and radio emission measurements of its opacity. Laboratory measurements of sulfuric acid, sulfur dioxide, water vapor, and carbon dioxide are used to model relative contributions to opacity as a function of height in a way that is consistent with observations of the constituents and absorbing properties of the atmosphere. It is concluded that sulfuric acid vapor is likely to be the principal microwave absorber in the 30-50 km altitude range of the middle atmosphere of Venus.

  11. A novel method for isolating and analyzing organic acids in biological cultures

    SciTech Connect

    Polman, K.

    1995-12-31

    Fermentatively produced organic acids have significant potential as chemical feedstocks for the production of various commodity materials. Such acids include acetic and succinic acids. Fermentations frequently result in the simultaneous production of two or more organic acids, and often other fermentation products as well. This necessitates separation of these products from each other, so that quantification and purification can be achieved. A multitude of methodologies for the identification, purification, and quantitation of organic acids has been developed and described; both liquid and gas chromatography have been used for such separations. High-performance liquid chromatography (HPLC) media used for the separation of organic acids have included C18 columns, Aminex HPX-87H (ion-moderated partition resin), TEAP-Si 100 Polyol (strongly basic anion-exchange resin), Dowex 1 (cation-exchange column), Shodex Ionpak KC811, and others. Methodologies for HPLC analysis of organic acids also vary in these aspects: (1) Sample pretreatment (e.g., pretreatment with Sep-Pak C18 cartridges or with DEAE-Sephadex); (2) Mobile-phase composition (e.g., dilute sulfuric acid or formic acid); and (3) Method of organic acid detection (e.g., refractive index or light absorption). In this study, we present a methodology for isolating and quantifying organic acids found in fermentation broths. The methodology is simple, utilizes dual separation chemistries to effect an enhanced separation capacity, and is durable in terms of HPLC column life.

  12. Effects of ruminal infusion of garlic oil on fermentation dynamics, Fatty Acid profile and abundance of bacteria involved in biohydrogenation in rumen of goats.

    PubMed

    Zhu, Zhi; Mao, Shengyong; Zhu, Weiyun

    2012-07-01

    This study aimed to investigate the effects of ruminal infusion of garlic oil (GO) on fermentation dynamics, fatty acid (FA) profile, and abundance of bacteria involved in biohydrogenation in the rumen. Six wethers fitted with ruminal fistula were assigned to two groups for cross-over design with a 14-d interval. Each 30-d experimental period consisted of a 27-d adaptation and a 3-d sample collection. Goats were fed a basal diet without (control) or with GO ruminal infusion (0.8 g/d). Ruminal contents collected before (0 h) and at 2, 4, 6, 8, and 10 h after morning feeding were used for fermentation analysis, and 0 h samples were further used for FA determination and DNA extraction. Garlic oil had no influence on dry matter intakes of concentrate and hay. During ruminal fermentation, GO had no effects on total VFA concentration and individual VFA molar proportions, whereas GO increased the concentrations of ammonia nitrogen and microbial crude protein (p<0.05). Compared with control, GO group took a longer time for total VFA concentration and propionate molar proportion to reach their respective maxima after morning feeding. The ratio of acetate to propionate in control reduced sharply after morning feeding, whereas it remained relatively stable in GO group. Fatty acid analysis showed that GO reduced saturated FA proportion (p<0.05), while increasing the proportions of C18, t11-18:1 (TVA), c9,t11-conjugated linoleic acid (c9,t11-CLA), t10,c12-CLA, and polyunsaturated FA (p<0.05). The values of TVA/(c9,t11-CLA+TVA) and C18:0/(TVA+ C18:0) were reduced by GO (p<0.05). Real-time PCR showed that GO tended to reduce Butyrivibrio proteoclasticus abundance (p = 0.058), whereas GO had no effect on total abundance of the Butyrivibrio group bacteria. A low correlation was found between B. proteoclasticus abundance and C18:0/(TVA+C18:0) (p = 0.910). The changes of fermentation over time suggested a role of GO in delaying the fermentation process and maintaining a relatively

  13. The influence of organic acids in relation to acid deposition in controlling the acidity of soil and stream waters on a seasonal basis.

    PubMed

    Chapman, Pippa J; Clark, Joanna M; Reynolds, Brian; Adamson, John K

    2008-01-01

    Much uncertainty still exists regarding the relative importance of organic acids in relation to acid deposition in controlling the acidity of soil and surface waters. This paper contributes to this debate by presenting analysis of seasonal variations in atmospheric deposition, soil solution and stream water chemistry for two UK headwater catchments with contrasting soils. Acid neutralising capacity (ANC), dissolved organic carbon (DOC) concentrations and the Na:Cl ratio of soil and stream waters displayed strong seasonal patterns with little seasonal variation observed in soil water pH. These patterns, plus the strong relationships between ANC, Cl and DOC, suggest that cation exchange and seasonal changes in the production of DOC and seasalt deposition are driving a shift in the proportion of acidity attributable to strong acid anions, from atmospheric deposition, during winter to predominantly organic acids in summer.

  14. Inhibition of succinic acid production in metabolically engineered Escherichia coli by neutralizing agent, organic acids, and osmolarity.

    PubMed

    Andersson, Christian; Helmerius, Jonas; Hodge, David; Berglund, Kris A; Rova, Ulrika

    2009-01-01

    The economical viability of biochemical succinic acid production is a result of many processing parameters including final succinic acid concentration, recovery of succinate, and the volumetric productivity. Maintaining volumetric productivities >2.5 g L(-1) h(-1) is important if production of succinic acid from renewable resources should be competitive. In this work, the effects of organic acids, osmolarity, and neutralizing agent (NH4OH, KOH, NaOH, K2CO3, and Na2CO3), and Na2CO3) on the fermentative succinic acid production by Escherichia coli AFP184 were investigated. The highest concentration of succinic acid, 77 g L(-1), was obtained with Na2CO3. In general, irrespective of the base used, succinic acid productivity per viable cell was significantly reduced as the concentration of the produced acid increased. Increased osmolarity resulting from base addition during succinate production only marginally affected the productivity per viable cell. Addition of the osmoprotectant glycine betaine to cultures resulted in an increased aerobic growth rate and anaerobic glucose consumption rate, but decreased succinic acid yield. When using NH4OH productivity completely ceased at a succinic acid concentration of approximately 40 g L(-1). Volumetric productivities remained at 2.5 g L(-1) h(-1) for up to 10 h longer when K- or Na-bases where used instead of NH4OH. The decrease in cellular succinic acid productivity observed during the anaerobic phase was found to be due to increased organic acid concentrations rather than medium osmolarity.

  15. Slowly digestible starch influences mRNA abundance of glucose and short-chain fatty acid transporters in the porcine distal intestinal tract.

    PubMed

    Woodward, A D; Regmi, P R; Gänzle, M G; van Kempen, T A T G; Zijlstra, R T

    2012-12-01

    The relationship between starch chemistry and intestinal nutrient transporters is not well characterized. We hypothesized that inclusion of slowly instead of rapidly digestible starch in pig diets will decrease glucose and increase short-chain fatty acid (SCFA) transporter expression in the distal gut. Weaned barrows (n = 32) were fed 4 diets containing 70% starch [ranging from 0 to 63% amylose and from 1.06 (rapidly) to 0.22%/min (slowly) rate of in vitro digestion] at 3 × maintenance energy requirement in a complete randomized block design. Ileal and colon mucosa was collected on day 21 to quantify mRNA abundance of Na(+)-dependent glucose transporter 1 (SGLT1), monocarboxylic acid transporter 1 (MCT1), and Na(+)-coupled monocarboxylate transporter (SMCT). Messenger RNA was extracted and cDNA manufactured prior to relative quantitative reverse transcription PCR. Data were analyzed using the 2(-Δ ΔC)(T) method, with β-actin and glyceraldehyde-3-phosphate dehydrogenase as reference genes, and regression analysis was performed. As in vitro rate of digestion decreased, SGLT1 linearly increased (P < 0.05) in the ileum. Contrary to SGLT1, MCT1 tended to linearly decrease (P = 0.08) in the ileum and increased quadratically (P < 0.001) in the colon with decreasing rate of digestion. Starch digestion rate did not affect SMCT in the ileum; however, colonic SMCT quadratically decreased (P < 0.01) with decreasing rate of digestion. In conclusion, in contrast to our hypothesis, slowly digestible starch increased ileal glucose and decreased ileal SCFA transporter mRNA abundance, possibly due to an increased glucose in the luminal ileum. Effects of starch on colonic SCFA transporter mRNA abundance were inconsistent.

  16. Impact of Fluorescent Lighting on Oxidation of Model Wine Solutions Containing Organic Acids and Iron.

    PubMed

    Grant-Preece, Paris; Barril, Celia; Schmidtke, Leigh M; Clark, Andrew C

    2017-03-22

    Previous studies have provided evidence that light exposure can increase oxygen consumption in wine and that the photodegradation of iron(III) tartrate could contribute to this process. In the present study, model wine solutions containing iron(III) and various organic acids, either alone or combined, were stored in sealed clear glass wine bottles and exposed to light from fluorescent lamps. Dissolved oxygen was monitored, and afterward the organic acid degradation products were determined and the capacity of the solutions to bind sulfur dioxide, the main wine preservative, was assessed. In the dark controls, little or no dissolved oxygen was consumed and the organic acids were stable. In the irradiated solutions, dissolved oxygen was consumed at a rate that was dependent on the specific organic acid present, and the latter were oxidized to various carbonyl compounds. For the solutions containing tartaric acid, malic acid, and/or citric acid, irradiation increased their sulfur dioxide-binding capacity.

  17. Disentangling the interactions between photochemical and bacterial degradation of dissolved organic matter: amino acids play a central role.

    PubMed

    Amado, André M; Cotner, James B; Cory, Rose M; Edhlund, Betsy L; McNeill, Kristopher

    2015-04-01

    Photochemical and bacterial degradation are important pathways to carbon mineralization and can be coupled in dissolved organic matter (DOM) decomposition. However, details of several mechanisms of the coupled photochemical and biological processing of DOM remain too poorly understood to achieve accurate predictions of the impact of these processes on DOM fate and reactivity. The aim of this study was to evaluate how photochemical degradation of amino acids affects bacterial metabolism and whether or not photochemical degradation of DOM competes for amino acids with biological processes. We examined the interactions between photochemical and bacterial degradation dynamics using a mixture of 18 amino acids and examined their dynamics and turnover rates within a larger pool of allochthonous or autochthonous DOM. We observed that photochemical exposure of DOM containing amino acids led to delayed biomass production (even though the final biomass did not differ), most likely due to a need for upregulation of biosynthetic pathways for amino acids that were damaged by photochemically produced reactive oxygen species (ROS). This response was most pronounced in bacterial communities where the abundance of photosensitive amino acids was highest (amended treatments and autochthonous DOM) and least pronounced when the abundance of these amino acids was low (unamended and allochthonous DOM), likely because these bacteria already had these biosynthetic pathways functioning. We observed both a cost and benefit associated with photochemical exposure of DOM. We observed a cost associated with photochemically produced ROS that partially degrade key amino acids and a benefit associated with an increase in the availability of other compounds in the DOM. Bacteria growing on DOM sources that are low in labile amino acids, such as those in terrestrially influenced environments, experience more of the benefits associated with photochemical exposure, whereas bacteria growing in more amino

  18. Teaching Relative Acidity in the Undergraduate Organic Chemistry Course.

    ERIC Educational Resources Information Center

    Traynham, James G.

    1988-01-01

    Described is a teaching method for connecting relative acidity among various species by the use of familiar references. Considered are teaching the acidity of alpha-hydrogens of ketones, alkylation of amides and imides, and others. (CW)

  19. Low-Vacuum Deposition of Glutamic Acid and Pyroglutamic Acid: A Facile Methodology for Depositing Organic Materials beyond Amino Acids.

    PubMed

    Sugimoto, Iwao; Maeda, Shunsaku; Suda, Yoriko; Makihara, Kenji; Takahashi, Kazuhiko

    2014-01-01

    Thin layers of pyroglutamic acid (Pygl) have been deposited by thermal evaporation of the molten L-glutamic acid (L-Glu) through intramolecular lactamization. This deposition was carried out with the versatile handmade low-vacuum coater, which was simply composed of a soldering iron placed in a vacuum degassing resin chamber evacuated by an oil-free diaphragm pump. Molecular structural analyses have revealed that thin solid film evaporated from the molten L-Glu is mainly composed of L-Pygl due to intramolecular lactamization. The major component of the L-Pygl was in β-phase and the minor component was in γ-phase, which would have been generated from partial racemization to DL-Pygl. Electron microscopy revealed that the L-Glu-evaporated film generally consisted of the 20 nm particulates of Pygl, which contained a periodic pattern spacing of 0.2 nm intervals indicating the formation of the single-molecular interval of the crystallized molecular networks. The DL-Pygl-evaporated film was composed of the original DL-Pygl preserving its crystal structures. This methodology is promising for depositing a wide range of the evaporable organic materials beyond amino acids. The quartz crystal resonator coated with the L-Glu-evaporated film exhibited the pressure-sensing capability based on the adsorption-desorption of the surrounding gas at the film surface.

  20. Low-Vacuum Deposition of Glutamic Acid and Pyroglutamic Acid: A Facile Methodology for Depositing Organic Materials beyond Amino Acids

    PubMed Central

    Sugimoto, Iwao; Maeda, Shunsaku; Suda, Yoriko; Makihara, Kenji; Takahashi, Kazuhiko

    2014-01-01

    Thin layers of pyroglutamic acid (Pygl) have been deposited by thermal evaporation of the molten L-glutamic acid (L-Glu) through intramolecular lactamization. This deposition was carried out with the versatile handmade low-vacuum coater, which was simply composed of a soldering iron placed in a vacuum degassing resin chamber evacuated by an oil-free diaphragm pump. Molecular structural analyses have revealed that thin solid film evaporated from the molten L-Glu is mainly composed of L-Pygl due to intramolecular lactamization. The major component of the L-Pygl was in β-phase and the minor component was in γ-phase, which would have been generated from partial racemization to DL-Pygl. Electron microscopy revealed that the L-Glu-evaporated film generally consisted of the 20 nm particulates of Pygl, which contained a periodic pattern spacing of 0.2 nm intervals indicating the formation of the single-molecular interval of the crystallized molecular networks. The DL-Pygl-evaporated film was composed of the original DL-Pygl preserving its crystal structures. This methodology is promising for depositing a wide range of the evaporable organic materials beyond amino acids. The quartz crystal resonator coated with the L-Glu-evaporated film exhibited the pressure-sensing capability based on the adsorption-desorption of the surrounding gas at the film surface. PMID:25254114

  1. The Changes in Color, Soluble Sugars, Organic Acids, Anthocyanins and Aroma Components in "Starkrimson" during the Ripening Period in China.

    PubMed

    Liu, Yulian; Chen, Nianlai; Ma, Zonghuan; Che, Fei; Mao, Juan; Chen, Baihong

    2016-06-22

    "Starkrimson" is a traditional apple cultivar that was developed a long time ago and was widely cultivated in the arid region of the northern Wei River of China. However, little information regarding the quality characteristics of "Starkrimson" fruit has been reported in this area. To elucidate these characteristics, the color, soluble sugars, organic acids, anthocyanins and aroma components were measured during the ripening period through the use of high performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS). The results indicated that the changes in anthocyanin contents took place later than the changes in the Commission International Eclairage (CIE) parameters. Meanwhile, cyanidin 3-galactoside (cy3-gal), fructose, sucrose, glucose and malic acid were the primary organic compounds, and 1-butanol-2-methyl-acetate, 2-hexenal and 1-hexanol were the most abundant aroma components in the skin. Furthermore, rapidly changing soluble sugars and organic acid synchronization took place in the early ripening period, while rapidly changing aroma components occurred later, on the basis of fresh weight. This result suggested that the production of aroma components might be a useful index of apple maturity.

  2. Characteristics of organic acids in the fruit of different pumpkin species.

    PubMed

    Nawirska-Olszańska, Agnieszka; Biesiada, Anita; Sokół-Łętowska, Anna; Kucharska, Alicja Z

    2014-04-01

    The aim of the research was to determine the composition of organic acids in fruit of different cultivars of three pumpkin species. The amount of acids immediately after fruit harvest and after 3 months of storage was compared. The content of organic acids in the examined pumpkin cultivars was assayed using the method of high performance liquid chromatography (HPLC). Three organic acids (citric acid, malic acid, and fumaric acid) were identified in the cultivars, whose content considerably varied depending on a cultivar. Three-month storage resulted in decreased content of the acids in the case of cultivars belonging to Cucurbita maxima and Cucurbita pepo species, while a slight increase was recorded for Cucurbita moschata species.

  3. Organic Acid Excretion in Penicillium ochrochloron Increases with Ambient pH

    PubMed Central

    Vrabl, Pamela; Fuchs, Viktoria; Pichler, Barbara; Schinagl, Christoph W.; Burgstaller, Wolfgang

    2012-01-01

    Despite being of high biotechnological relevance, many aspects of organic acid excretion in filamentous fungi like the influence of ambient pH are still insufficiently understood. While the excretion of an individual organic acid may peak at a certain pH value, the few available studies investigating a broader range of organic acids indicate that total organic acid excretion rises with increasing external pH. We hypothesized that this phenomenon might be a general response of filamentous fungi to increased ambient pH. If this is the case, the observation should be widely independent of the organism, growth conditions, or experimental design and might therefore be a crucial key point in understanding the function and mechanisms of organic acid excretion in filamentous fungi. In this study we explored this hypothesis using ammonium-limited chemostat cultivations (pH 2–7), and ammonium or phosphate-limited bioreactor batch cultivations (pH 5 and 7). Two strains of Penicillium ochrochloron were investigated differing in the spectrum of excreted organic acids. Confirming our hypothesis, the main result demonstrated that organic acid excretion in P. ochrochloron was enhanced at high external pH levels compared to low pH levels independent of the tested strain, nutrient limitation, and cultivation method. We discuss these findings against the background of three hypotheses explaining organic acid excretion in filamentous fungi, i.e., overflow metabolism, charge balance, and aggressive acidification hypothesis. PMID:22493592

  4. Regulating the Skin Permeation Rate of Escitalopram by Ion-pair Formation with Organic Acids.

    PubMed

    Song, Tian; Quan, Peng; Xiang, Rongwu; Fang, Liang

    2016-12-01

    In order to regulate the skin permeation rate (flux) of escitalopram (ESP), ion-pair strategy was used in our work. Five organic acids with different physicochemical properties, benzoic acid (BA), ibuprofen (IB), salicylic acid (SA), benzenesulfonic acid (BSA), and p-aminobenzoic acid (PABA), were employed as counter-ions to regulate the permeation rate of ESP across the rabbit abdominal skin in vitro. The interaction between ESP and organic acids was characterized by FTIR and (13)C NMR spectroscopy. Results showed that all organic acids investigated in this study performed a controlling effect on ESP flux. To further analyze the factors concerned with the permeation capability of ESP-acid complex, a multiple linear regression model was used. It is concluded that the steady-state flux (J) of ESP-acid complexes had a positive correlation with log K o/w (the n-octanol/water partition coefficient of ion-pair complex) and pK a (the acidity of organic acid counter-ion), but a negative correlation with MW (the molecular weight of ion-pair complex). The logK o/w of ion-pair complex is the primary one in all the factors that influence the skin permeation rate of ESP. The results demonstrated that organic acid with appropriate physicochemical properties can be considered as suitable candidate for the transdermal drug delivery of escitalopram.

  5. Stable carbon isotopic compositions of low-molecular-weight dicarboxylic acids, oxocarboxylic acids, α-dicarbonyls, and fatty acids: Implications for atmospheric processing of organic aerosols

    NASA Astrophysics Data System (ADS)

    Zhang, Yan-Lin; Kawamura, Kimitaka; Cao, Fang; Lee, Meehye

    2016-04-01

    Stable carbon isotopic compositions (δ13C) were measured for 23 individual organic species including 9 dicarboxylic acids, 7 oxocarboxylic acids, 1 tricarboxylic acid, 2 α-dicarbonyls, and 4 fatty acids in the aerosols from Gosan background site in East Asia. δ13C values of particle phase glyoxal and methylglyoxal are significantly larger than those previously reported for isoprene and other precursors. The values are consistently less negative in oxalic acid (C2, average -14.1‰), glyoxylic acid (-13.8‰), pyruvic acid (-19.4‰), glyoxal (-13.5‰), and methylglyoxal (-18.6‰) compared to other organic species (e.g., palmitic acid, -26.3‰), which can be explained by the kinetic isotope effects during atmospheric oxidation of pre-aged precursors (e.g., isoprene) and the subsequent gas-particle partitioning after the evaporation of clouds or wet aerosols. The δ13C values of C2 is positively correlated with C2 to organic carbon ratio, indicating that photochemical production of C2 is more pronounced than its degradation during long-range atmospheric transport. The isotopic results also suggest that aqueous phase oxidation of glyoxal and methylglyoxal is a major formation process of oxalic acid via the intermediates such as glyoxylic acid and pyruvic acid. This study provides evidence that organic aerosols are intensively photochemically aged in the western North Pacific rim.

  6. Low-molecular-weight organic acids in the Tibetan Plateau: Results from one-year of precipitation samples at the SET station

    NASA Astrophysics Data System (ADS)

    Liu, Bin; Kang, Shichang; Sun, Jimin; Wan, Xin; Wang, Yongjie; Gao, Shaopeng; Cong, Zhiyuan

    2014-04-01

    Background atmospheric organic acids: formic (F), acetic (A), oxalic (O), and methanesulfonic (MSA, abbreviated to M) acids in the southern Tibetan Plateau (TP), were determined in one-year of precipitation measurements at a remote alpine station. These organic acids were dominated by oxalic (volume-weighted mean of 0.51 μmol l-1)/formic acid (0.38 μmol l-1), followed by acetic acid (0.20 μmol l-1) and MSA (0.10 μmol l-1). Their levels were comparable with those from other remote sites, while they were lower than those found in populated areas. The South Asian monsoon is responsible for the seasonal variation of organic acid concentration: a relative abundance of MSA and lower concentrations of other organic acids (by the dilution effect) in the monsoon season, while opposite in the non-monsoon season. Diverse sources were identified by principal component analysis combined with the corresponding tracers. These were anthropogenic disturbances (which explain 41% of the variance), marine emission (24%), and biogenic emission (16%). Moreover, the variances of F/A, M/(F + A), and O/(F + A) in monsoonal versus non-monsoonal samples, were involved with the changes of sources. Furthermore, these chemical indexes suggest that active photochemistry over the TP was significant for the production of organic acids and consequently enhanced the ratios of M/(F + A) and O/(F + A) in monsoonal rainfalls. The elevated organic compounds within the ascending tropical moisture imply potential significances for the secondary formation of organic acids in the high-altitude and the changes of the Asian monsoon.

  7. [Determination of organic acids in rice wine by ion-exclusion chromatography].

    PubMed

    Lin, Xiaojie; Wei, Wei; He, Zhigang; Lin, Xiaozi

    2014-03-01

    An ion-exclusion chromatographic method for the simultaneous determination of organic acids in rice wine was developed. An IC-Pak Ion Exclusion column (300 mm x 7.8 mm, 7 microm) was used at 50 degrees C. The mobile phases were H2SO4 (phase A) and acetonitrile (phase B) (98:2, v/v) at a flow rate of 0.5 mL/min. The gradient elution program was as follows: 0-40 min, 0.01 mol/L H2SO4 to 0.02 mol/L H2SO4; 40-50 min, 0.01 mol/L H2SO4. The injection volume was 10 microL. The detection wavelength was set at 210 nm. The results showed that oxalic acid, maleic acid, citric acid, tartaric acid, malic acid, ascorbic acid, succinic acid, lactic, fumaric acid, acetic acid, propionic acid, isobutyric acid and butyric acid were completely separated and determined in 30 min. The linear correlation coefficients were above 0.999 7 in the range of 0.001- 1.000 g/L. Under the optimized conditions, the recoveries of organic acids in rice wine were in the range of 93.4% - 103.8% with the relative standard deviations (RSDs, n = 5) of 0.1% - 1.5%. This method is feasible, convenient, fast, accurate and applicable for the quantitative analysis of the organic acids in rice wine.

  8. Alteration of organic matter during infaunal polychaete gut passage and links to sediment organic geochemistry. Part II: Fatty acids and aldoses

    NASA Astrophysics Data System (ADS)

    Woulds, Clare; Middelburg, Jack J.; Cowie, Greg L.

    2014-07-01

    The activities of sediment-dwelling fauna are known to influence the rates of and pathways through which organic matter is cycled in marine sediments, and thus to influence eventual organic carbon burial or decay. However, due to methodological constraints, the role of faunal gut passage in determining the subsequent composition and thus degradability of organic matter is relatively little studied. Previous studies of organic matter digestion by benthic fauna have been unable to detect uptake and retention of specific biochemicals in faunal tissues, and have been of durations too short to fit digestion into the context of longer-term sedimentary degradation processes. Therefore this study aimed to investigate the aldose and fatty acid compositional alterations occurring to organic matter during gut passage by the abundant and ubiquitous polychaetes Hediste diversicolor and Arenicola marina, and to link these to longer-term changes typically observed during organic matter decay. This aim was approached through microcosm experiments in which selected polychaetes were fed with 13C-labelled algal detritus, and organisms, sediments, and faecal pellets were sampled at three timepoints over ∼6 weeks. Samples were analysed for their 13C-labelled aldose and fatty acid contents using GC-MS and GC-IRMS. Compound-selective net accumulation of biochemicals in polychaete tissues was observed for both aldoses and fatty acids, and the patterns of this were taxon-specific. The dominant patterns included an overall loss of glucose and polyunsaturated fatty acids; and preferential preservation or production of arabinose, microbial compounds (rhamnose, fucose and microbial fatty acids), and animal-synthesised fatty acids. These patterns may have been driven by fatty acid essentiality, preferential metabolism of glucose, and A. marina grazing on bacteria. Fatty acid suites in sediments from faunated microcosms showed greater proportions of saturated fatty acids and bacterial markers

  9. Robust and Porous β-Diketiminate-Functionalized Metal–Organic Frameworks for Earth-Abundant-Metal-Catalyzed C–H Amination and Hydrogenation

    SciTech Connect

    Thacker, Nathan C.; Lin, Zekai; Zhang, Teng; Gilhula, James C.; Abney, Carter W.; Lin, Wenbin

    2016-05-27

    We have designed a strategy for postsynthesis installation of the β-diketiminate (NacNac) functionality in a metal–organic framework (MOF) of UiO-topology. Metalation of the NacNac-MOF (I) with earth-abundant metal salts afforded the desired MOF-supported NacNac-M complexes (M = Fe, Cu, and Co) with coordination environments established by detailed EXAFS studies. The NacNac-Fe-MOF catalyst, I•Fe(Me), efficiently catalyzed the challenging intramolecular sp3 C–H amination of a series of alkyl azides to afford α-substituted pyrrolidines. The NacNac-Cu-MOF catalyst, I•Cu(THF), was effective in promoting the intermolecular sp3 C–H amination of cyclohexene using unprotected anilines to provide access to secondary amines in excellent selectivity. Finally, the NacNac-Co-MOF catalyst, I•Co(H), was used to catalyze alkene hydrogenation with turnover numbers (TONs) as high as 700 000. All of the NacNac-M-MOF catalysts were more effective than their analogous homogeneous catalysts and could be recycled and reused without a noticeable decrease in yield. The NacNac-MOFs thus provide a novel platform for engineering recyclable earth-abundant-element-based single-site solid catalysts for many important organic transformations.

  10. Organosulfates and organic acids in Arctic aerosols: speciation, annual variation and concentration levels

    NASA Astrophysics Data System (ADS)

    Hansen, A. M. K.; Kristensen, K.; Nguyen, Q. T.; Zare, A.; Cozzi, F.; Nøjgaard, J. K.; Skov, H.; Brandt, J.; Christensen, J. H.; Ström, J.; Tunved, P.; Krejci, R.; Glasius, M.

    2014-08-01

    Sources, composition and occurrence of secondary organic aerosols in the Arctic were investigated at Zeppelin Mountain, Svalbard, and Station Nord, northeastern Greenland, during the full annual cycle of 2008 and 2010, respectively. Speciation of organic acids, organosulfates and nitrooxy organosulfates - from both anthropogenic and biogenic precursors were in focus. A total of 11 organic acids (terpenylic acid, benzoic acid, phthalic acid, pinic acid, suberic acid, azelaic acid, adipic acid, pimelic acid, pinonic acid, diaterpenylic acid acetate and 3-methyl-1,2,3-butanetricarboxylic acid), 12 organosulfates and 1 nitrooxy organosulfate were identified in aerosol samples from the two sites using a high-performance liquid chromatograph (HPLC) coupled to a quadrupole Time-of-Flight mass spectrometer. At Station Nord, compound concentrations followed a distinct annual pattern, where high mean concentrations of organosulfates (47 ± 14 ng m-3) and organic acids (11.5 ± 4 ng m-3) were observed in January, February and March, contrary to considerably lower mean concentrations of organosulfates (2 ± 3 ng m-3) and organic acids (2.2 ± 1 ng m-3) observed during the rest of the year. At Zeppelin Mountain, organosulfate and organic acid concentrations remained relatively constant during most of the year at a mean concentration of 15 ± 4 ng m-3 and 3.9 ± 1 ng m-3, respectively. However during four weeks of spring, remarkably higher concentrations of total organosulfates (23-36 ng m-3) and total organic acids (7-10 ng m-3) were observed. Elevated organosulfate and organic acid concentrations coincided with the Arctic haze period at both stations, where northern Eurasia was identified as the main source region. Air mass transport from northern Eurasia to Zeppelin Mountain was associated with a 100% increase in the number of detected organosulfate species compared with periods of air mass transport from the Arctic Ocean, Scandinavia and Greenland. The results from this

  11. Electrodeposition of lustrous tin-lead alloys in acidic electrolytes with organic additives

    SciTech Connect

    Selivanova, G.A.; Maksimenko, S.A.; Tyutina, K.M.

    1994-09-01

    Galvanic coatings based on tin-lead alloys are mainly used in radio-engineering and electronic industries to prepare certain products, including printed-circuit boards, for soldering. To improve ecological safety of the proces, the authors studied a new electrolyte for depositing a tin-lead alloy based on nontoxic and abundant perchloric acid, as well as electrolytes based on mono- and trichloroacetic acids.

  12. Formic and Acetic Acid Observations over Colorado by Chemical Ionization Mass Spectrometry and Organic Acids' Role in Air Quality

    NASA Astrophysics Data System (ADS)

    Treadaway, V.; O'Sullivan, D. W.; Heikes, B.; Silwal, I.; McNeill, A.

    2015-12-01

    Formic acid (HFo) and acetic acid (HAc) have both natural and anthropogenic sources and a role in the atmospheric processing of carbon. These organic acids also have an increasing importance in setting the acidity of rain and snow as precipitation nitrate and sulfate concentrations have decreased. Primary emissions for both organic acids include biomass burning, agriculture, and motor vehicle emissions. Secondary production is also a substantial source for both acids especially from biogenic precursors, secondary organic aerosols (SOAs), and photochemical production from volatile organic compounds (VOCs) and oxygenated volatile organic compounds (OVOCs). Chemical transport models underestimate organic acid concentrations and recent research has sought to develop additional production mechanisms. Here we report HFo and HAc measurements during two campaigns over Colorado using the peroxide chemical ionization mass spectrometer (PCIMS). Iodide clusters of both HFo and HAc were recorded at mass-to-charge ratios of 173 and 187, respectively. The PCIMS was flown aboard the NCAR Gulfstream-V platform during the Deep Convective Clouds and Chemistry Experiment (DC3) and aboard the NCAR C-130 during the Front Range Air Pollution and Photochemistry Experiment (FRAPPE). The DC3 observations were made in May and June 2012 extending from the surface to 13 km over the central and eastern United States. FRAPPE observations were made in July and August 2014 from the surface to 7 km over Colorado. DC3 measurements reported here are focused over the Colorado Front Range and complement the FRAPPE observations. DC3 HFo altitude profiles are characterized by a decrease up to 6 km followed by an increase either back to boundary layer mixing ratio values or higher (a "C" shape). Organic acid measurements from both campaigns are interpreted with an emphasis on emission sources (both natural and anthropogenic) over Colorado and in situ photochemical production especially ozone precursors.

  13. Impact of improving dietary amino acid balance for lactating sows on efficiency of dietary amino acid utilization and transcript abundance of genes encoding lysine transporters in mammary tissue.

    PubMed

    Huber, L; de Lange, C F M; Ernst, C W; Krogh, U; Trottier, N L

    2016-11-01

    Lactating multiparous Yorkshire sows ( = 64) were used in 2 experiments to test the hypothesis that reducing dietary CP intake and improving AA balance through crystalline AA (CAA) supplementation improves apparent dietary AA utilization efficiency for milk production and increases transcript abundance of genes encoding Lys transporter proteins in mammary tissue. In Exp. 1, 40 sows were assigned to 1 of 4 diets: 1) high CP (HCP; 16.0% CP, as-fed basis; analyzed concentration), 2) medium-high CP (MHCP; 15.7% CP), 3) medium-low CP (MLCP; 14.3% CP), and 4) low CP (LCP; 13.2% CP). The HCP diet was formulated using soybean meal and corn as the only Lys sources. The reduced-CP diets contained CAA to meet estimated requirements for essential AA that became progressively limiting with reduction in CP concentration, that is, Lys, Ile, Met + Cys, Thr, Trp, and Val. Dietary standardized ileal digestible (SID) Lys concentration was 80% of the estimated requirement. In Exp. 2, 24 sows were assigned to the HCP or LCP diets. In Exp. 1, blood samples were postprandially collected 15 h on d 3, 7, 14, and 18 of lactation and utilization efficiency of dietary AA for milk production was calculated during early (d 3 to 7) and peak (d 14 to 18) lactation. Efficiency values were estimated from daily SID AA intakes and milk AA yield, with corrections for maternal AA requirement for maintenance and AA contribution from body protein losses. In Exp. 2, mammary tissue was biopsied on d 4 and 14 of lactation to determine the mRNA abundance of genes encoding Lys transporter proteins. In peak lactation, Lys, Thr, Trp, and Val utilization efficiency increased with decreasing dietary CP (linear for Trp and Val, < 0.05; in sows fed the MHCP diet vs. sows fed the HCP diet for Lys and Thr, < 0.05). Total essential and nonessential 15-h postprandial serum AA concentrations increased with decreasing dietary CP (linear, = 0.09 and < 0.05, respectively), suggesting increased maternal body protein

  14. Tropospheric chemistry of internally mixed sea salt and organic particles: Surprising reactivity of NaCl with weak organic acids

    NASA Astrophysics Data System (ADS)

    Laskin, Alexander; Moffet, Ryan C.; Gilles, Mary K.; Fast, Jerome D.; Zaveri, Rahul A.; Wang, Bingbing; Nigge, Pascal; Shutthanandan, Janani

    2012-08-01

    Chemical imaging analysis of internally mixed sea salt/organic particles collected onboard the Department of Energy (DOE) G-1 aircraft during the 2010 Carbonaceous Aerosols and Radiative Effects Study (CARES) was performed using electron microscopy and X-ray spectro-microscopy. Substantial chloride depletion in aged sea salt particles was observed, which could not be explained by the known atmospheric reactivity of sea salt with inorganic nitric and sulfuric acids. We present field evidence that chloride components in sea salt particles may effectively react with organic acids releasing HCl gas to the atmosphere, leaving behind particles depleted in chloride and enriched in the corresponding organic salts. While formation of the organic salts products is not thermodynamically favored for bulk aqueous chemistry, these reactions in aerosol are driven by high volatility and evaporation of the HCl product from drying particles. These field observations were corroborated in a set of laboratory experiments where NaCl particles mixed with organic acids were found to be depleted in chloride. Combined together, the results indicate substantial chemical reactivity of sea salt particles with secondary organics that has been largely overlooked in the atmospheric aerosol chemistry. Atmospheric aging, and in particular hydration-dehydration cycles of mixed sea salt/organic particles, may result in formation of organic salts that will modify the acidity, hygroscopic, and optical properties of aged particles.

  15. Tropospheric Chemistry of Internally Mixed Sea Salt and Organic Particles: Surprising Reactivity of NaCl with Weak Organic Acids

    SciTech Connect

    Laskin, Alexander; Moffet, Ryan C.; Gilles, Marry K.; Fast, Jerome D.; Zaveri, Rahul A.; Wang, Bingbing; Nigge, P.; Shutthanandan, Janani I.

    2012-08-03

    Chemical imaging analysis of internally mixed sea salt/organic particles collected on board the Department of Energy (DOE) G-1 aircraft during the 2010 Carbonaceous Aerosols and Radiative Effects Study (CARES) was performed using electron microscopy and X-ray spectro-microscopy techniques. Substantial chloride depletion in aged sea salt particles was observed, which could not be explained by the known atmospheric reactivity of sea salt with inorganic nitric and sulfuric acids. We present field evidence that chloride components in sea salt particles may effectively react with organic acids releasing HCl gas to the atmosphere, leaving behind particles depleted in chloride and enriched in the corresponding organic salts. While formation of the organic salts products is not thermodynamically favored for bulk aqueous chemistry, these reactions in aerosol are driven by high volatility and irreversible evaporation of the HCl product from drying particles. These field observations were corroborated in a set of laboratory experiments where NaCl particles mixed with organic acids were found to be depleted in chloride. Combined together, the results indicate substantial chemical reactivity of sea salt particles with secondary organics that has been largely overlooked in the atmospheric aerosol chemistry. Atmospheric aging, and especially hydration-dehydration cycles of mixed sea salt/organic particles may result in formation of organic salts that will modify acidity, hygroscopic and optical properties of aged particles.

  16. Semicontinuous measurements of organic carbon and acidity during the Pittsburgh air quality study: implications for acid-catalyzed organic aerosol formation

    SciTech Connect

    S. Takahama; C.I. Davidson; S.N. Pandis

    2006-04-01

    Laboratory evidence suggests that inorganic acid seed particles may increase secondary organic aerosol yields secondary organic aerosol (SOA) through heterogeneous chemistry. Additional laboratory studies, however, report that organic acidity generated in the same photochemical process by which SOA is formed may be sufficient to catalyze these heterogeneous reactions. Understanding the interaction between inorganic acidity and SOA mass is important when evaluating emission controls to meet PM2.5 regulations. Semicontinuous measurements of organic carbon (OC), elemental carbon (EC), and inorganic species from the Pittsburgh Air Quality Study were examined to determine if coupling in the variations of inorganic acidity and OC could be detected. Significant enhancements of SOA production could not be detected due to inorganic acidity in Western Pennsylvania most of the time, but its signal might have been lost in the noise. If a causal relationship between inorganic acidity and OC is assumed, reductions in OC for Western Pennsylvania that might result from drastic reductions in inorganic acidity were estimated to be 2 {+-} 4% by a regression technique, and an upper bound for this geographic area was estimated to be 5 {+-} 8% based on calculations from laboratory measurements. 48 refs., 7 figs., 3 tabs.

  17. Dissolution behavior of Caldag lateritic nickel ore subjected to a sequential organic acid leaching method

    NASA Astrophysics Data System (ADS)

    Kursunoglu, Sait; Kaya, Muammer

    2015-11-01

    The dissolution behavior of Caldag lateritic nickel ore subjected to a sequential organic acid leaching method was investigated. The effects of the type of organic acid, acid concentration, leaching time, and leaching temperature on the lateritic nickel ore were examined. Organic acids were used individually prior to sequential leaching. Citric acid was more effective than the other two acids for the selective leaching of nickel and cobalt. An increase in the citric acid concentration negligibly affected the dissolution of the metals, whereas temperature exhibited a strong beneficial effect. Oxalic acid was determined to be the most appropriate organic acid for the second leaching step. After 8 h (4 h + 4 h) of leaching with organic acids (0.5 M citric + 0.5 M oxalic) in sequence at 90°C, 89.63% Ni, 82.89% Co, and 69.63% Fe were leached from the lateritic nickel ore. A sequential citric + oxalic acid leaching method could represent a viable alternative for the dissolution of metals from lateritic nickel ore.

  18. Stable carbon isotopic compositions of low-molecular-weight dicarboxylic acids, oxocarboxylic acids, α-dicarbonyls, and fatty acids: implications for atmospheric processing of organic aerosols

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Kawamura, K.; Cao, F.; Lee, M.

    2015-12-01

    Stable carbon isotopic compositions (δ13C) were measured for 23 individual organic species including 9 dicarboxylic acids, 7 oxocarboxylic acids, 1 tricarboxylic acid, 2 α-dicarbonyls and 4 fatty acids in the aerosols from Gosan background site in East Asia. δ13C of particle-phase glyoxal and methylglyoxal are significantly higher than those previously reported for isoprene and other precursors, associated with isotope fractionation during atmospheric oxidation. 13C is consistently more enriched for oxalic acid (C2), glyoxylic acid, pyruvic acid, glyoxal and methylglyoxal compared to other organic compounds identified, which can be explained by the kinetic isotope effects during aqueous-phase processing and the subsequent gas-particle partitioning after clouds or wet aerosols evaporation δ13C of C2 is positively correlated with C2 and organic carbon ratio, indicating that a photochemical production of C2 is more pronounced than its degradation process during long-range transport. The 13C results also suggest that aqueous-phase oxidation of glyoxal and methylglyoxal is major formation process of oxalic acid production via the major intermediates glyoxylic acid and pyruvic acid. This study provides evidence that organic aerosols are intensively photo-chemically aged in this region.

  19. Hydrogen bonded supramolecular structures of eight organic salts based on 2,6-diaminopyridine, and organic acids

    NASA Astrophysics Data System (ADS)

    Jin, Shouwen; Zhao, Ying; Liu, Bin; Jin, Xiunan; Zhang, Huan; Wen, Xianhong; Liu, Hui; Jin, Li; Wang, Daqi

    2015-11-01

    Here anhydrous and hydrated multi-component organic acid-base salts of 2,6-diaminopyridine have been prepared with the organic acids as trichloroacetic acid, 3,5-dinitrobenzoic acid, 5-nitrosalicylic acid, 3,5-dihydroxybenzoic acid, 5-sulfosalicylic acid, m-phthalic acid, naphthalene-1,5-disulfonic acid, and glutaric acid. The eight crystalline compounds were characterized by X-ray diffraction analysis, infrared (IR), melting point (mp), and elemental analysis. Except salt 4, all structures adopted the hetero R22(8) supramolecular synthon. There were extensive N-H···O/O-H···O/N-H···N/N-H···S hydrogen bonds as well as CH···O, CH-N, CH-π, NH-π, π-π, C-π, Cl-O, and O-O interactions in the supramolecular architectures. The combination of these weak and strong hydrogen bonding associations in the crystal packing led to the formation of the 2D/3D structures.

  20. Organic Acid Concentrations in Rivers Within the Amazon River Drainage Basin

    NASA Astrophysics Data System (ADS)

    Skoog, A.

    2007-12-01

    The composition of the dissolved organic matter pool in both fresh and marine waters is largely unknown. Concentrations of low-molecular-weight organic acids (oxalate, citrate, glycolate, formate, acetate, succinate) have been determined in Brasilian (18 rivers sampled) and Peruvian (19 rivers sampled) rivers within the Amazon River drainage basin. Succinate concentrations were below the detection limit in all rivers. The dominant acid varied among the sampled rivers, indicating that organic acid concentrations depend on river basin characteristics. Organic-acid carbon comprised a highly significant, but variable, fraction of total dissolved carbon, with a range of 3-90%, indicating that organic-acid-derived carbon may be an important source of biologically labile carbon within the Amazon River drainage basin.

  1. Organic acids enhanced decoloration of azo dye in gas phase surface discharge plasma system.

    PubMed

    Wang, Tiecheng; Qu, Guangzhou; Ren, Jingyu; Sun, Qiuhong; Liang, Dongli; Hu, Shibin

    2016-01-25

    A gas phase surface discharge plasma combined with organic acids system was developed to enhance active species mass transfer and dye-containing wastewater treatment efficacy, with Acid Orange II (AO7) as the model pollutant. The effects of discharge voltage and various organic acid additives (acetic acid, lactic acid and nonoic acid) on AO7 decoloration efficiency were evaluated. The experimental results showed that an AO7 decoloration efficiency of approximately 69.0% was obtained within 4 min of discharge plasma treatment without organic acid addition, which was improved to 82.8%, 83.5% and 88.6% within the same treatment time with the addition of acetic acid, lactic acid and nonoic acid, respectively. The enhancement effects on AO7 decoloration efficiency could be attributed to the decrease in aqueous surface tension, improvement in bubble distribution and shape, and increase in ozone equivalent concentration. The AO7 wastewater was biodegradable after discharge plasma treatment with the addition of organic acid. AO7 decomposition intermediates were analyzed by UV-vis spectrometry and GC-MS; 2-naphthol, 1,4-benzoquinone, phthalic anhydride, coumarin, 1,2-naphthoquinone, and 2-formyl-benzoic acid were detected. A possible pathway for AO7 decomposition in this system was proposed.

  2. Thermophysical properties of starch and whey protein composite prepared in presence of organic acid and esters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previously, we prepared starch and protein composite by reactive mixing in presence of various organic acids and found that use of these acid esters resulted in composites with good mechanical properties. In this study, concentration (% w/w) of acid citrates in the starch-protein composites were var...

  3. Annual cycle and spatial trends in fatty acid composition of suspended particulate organic matter across the Beaufort Sea shelf

    NASA Astrophysics Data System (ADS)

    Connelly, Tara L.; Businski, Tara N.; Deibel, Don; Parrish, Christopher C.; Trela, Piotr

    2016-11-01

    Fatty acid profiles of suspended particulate organic matter (POM) were determined over an annual cycle (September 2003 to August 2004) on the Beaufort Sea shelf, Canadian Arctic. Special emphasis was placed on the nutritional quality of the fatty acid pool available to zooplankton by examining spatial and temporal patterns in the proportions of total polyunsaturated fatty acids (PUFA) and the essential fatty acids 22:6n-3 (DHA) and 20:5n-3 (EPA). EPA and DHA were the two most abundant PUFA throughout the study period. A log-ratio multivariate (LRA) analysis revealed strong structure in fatty acid profiles related to season and depth. Dominant fatty acids accounting for the observed trend included 18:5n-3, 18:4n-3, 16:1n-7, 20:5n-3, 18:0 and 20:3n-3. We observed a shift in fatty acid profiles from summer to autumn (e.g., from 16:1n-7 and EPA to 18:5n-3 and 18:4n-3) that likely corresponded to a shift in the relative importance of diatoms versus dinoflagellates, prymnesiophytes and/or prasinophytes to the POM pool. Fatty acid composition during winter was dominated by more refractory saturated fatty acids. A surprising finding was the depth and seasonal trend of 20:3n-3, which was higher in winter, aligned with 18:0 in the LRA, but behaved differently than other n-3 PUFA. We interpret fatty acid profiles during summer to be predominantly driven by phytoplankton inputs, whereas fatty acid profiles in winter were dominated by fatty acids that were left over after consumption and/or were generated by heterotrophs. The highest diatom inputs (EPA, the diatom fatty acid marker), n-3/n-6 ratios, and C16 PUFA index were located in an upwelling region off Cape Bathurst. This study is the first annual time series of fatty acid profiles of POM in Arctic seas, expanding our knowledge of the composition of POM throughout the dark season.

  4. Field and Laboratory Studies of Reactions between Atmospheric Water Soluble Organic Acids and Inorganic Particles

    SciTech Connect

    Wang, Bingbing; Kelly, Stephen T.; Sellon, Rachel E.; Shilling, John E.; Tivanski, Alexei V.; Moffet, Ryan C.; Gilles, Mary K.; Laskin, Alexander

    2013-06-25

    Atmospheric inorganic particles undergo complex heterogeneous reactions that change their physicochemical properties. Depletion of chloride in sea salt particles was reported in previous field studies and was attributed to the acid displacement of chlorides with inorganic acids, such as nitric and sulfuric acids [1-2]. Recently, we showed that NaCl can react with water soluble organic acids (WSOA) and release gaseous hydrochloric acid (HCl) resulting in formation of organic salts [3]. A similar mechanism is also applicable to mixed WSOA/nitrate particles where multi-phase reactions are driven by the volatility of nitric acid. Furthermore, secondary organic material, which is a complex mixture of carboxylic acids, exhibits the same reactivity towards chlorides and nitrates. Here, we present a systematic study of reactions between atmospheric relevant WSOA, SOM, and inorganic salts including NaCl, NaNO3, and Ca(NO3)2 using complementary micro-spectroscopy analysis.

  5. Determination of organic acids in leaves and rinds of Garcinia indica (Desr.) by LC.

    PubMed

    Jayaprakasha, G K; Sakariah, K K

    2002-04-15

    Organic acids in leaves and rinds of Garcinia indica (Kokam) were determined by high-performance liquid chromatography. The major organic acid in leaves and rinds has been found to be (-)-hydroxycitric acid present to the extent of 4.1-4.6 and 10.3-12.7%, respectively, by isocratic elution with 8 mM sulfuric acid as mobile phase with a flow rate of 1.0 ml/min using UV detection at 210 nm. Hydroxycitric acid lactone and citric acid are present in leaves and rinds in minor quantities. This method has been shown to be very reproducible with the coefficient of variation ranging from 2.8 to 4.2%. This is the first report on the composition of organic acids in the leaves and rinds of G. indica by HPLC.

  6. Acyl Meldrum's acid derivatives: application in organic synthesis

    NASA Astrophysics Data System (ADS)

    Janikowska, K.; Rachoń, J.; Makowiec, S.

    2014-07-01

    This review is focused on an important class of Meldrum's acid derivatives commonly known as acyl Meldrum's acids. The preparation methods of these compounds are considered including the recently proposed and rather rarely used ones. The chemical properties of acyl Meldrum's acids are described in detail, including thermal stability and reactions with various nucleophiles. The possible mechanisms of these transformations are analyzed. The bibliography includes 134 references.

  7. Effects of pH adjustment and sodium ions on sour taste intensity of organic acids.

    PubMed

    Neta, E R D; Johanningsmeier, S D; Drake, M A; McFeeters, R F

    2009-01-01

    Protonated organic acid species have been shown to be the primary stimuli responsible for sour taste of organic acids. However, we have observed that sour taste may be modulated when the pH of acid solutions is raised using sodium hydroxide. Objectives were to evaluate the effect of pH adjustment on sour taste of equimolar protonated organic acid solutions and to investigate the potential roles of organic anions and sodium ions on sour taste perception. Despite equal concentrations of protonated acid species, sour taste intensity decreased significantly with increased pH for acetic, lactic, malic, and citric acids (P < 0.05). Total organic anion concentration did not explain the suppression of sour taste in solutions containing a blend of 3 organic acids with constant concentration of protonated organic acid species and hydrogen ions and variable organic anion concentrations (R(2)= 0.480, P = 0.12). Sour taste suppression in these solutions seemed to be more closely related to sodium ions added in the form of NaOH (R(2)= 0.861, P = 0.007). Addition of 20 mM NaCl to acid solutions resulted in significant suppression of sour taste (P = 0.016). However, sour taste did not decrease with further addition of NaCl up to 80 mM. Presence of sodium ions was clearly shown to decrease sour taste of organic acid solutions. Nonetheless, suppression of sour taste in pH adjusted single acid solutions was greater than what would be expected based on the sodium ion concentration alone, indicating an additional suppression mechanism may be involved.

  8. Sea salt aerosols as a reactive surface for inorganic and organic acidic gases in the Arctic troposphere

    NASA Astrophysics Data System (ADS)

    Chi, J. W.; Li, W. J.; Zhang, D. Z.; Zhang, J. C.; Lin, Y. T.; Shen, X. J.; Sun, J. Y.; Chen, J. M.; Zhang, X. Y.; Zhang, Y. M.; Wang, W. X.

    2015-10-01

    Sea salt aerosols (SSA) are dominant particles in the Arctic atmosphere and determine the polar radiative balance. SSA react with acidic pollutants that lead to changes in physical and chemical properties of their surface, which in turn alter their hygroscopic and optical properties. Transmission electron microscopy with energy-dispersive X-ray spectrometry was used to analyze morphology, composition, size, and mixing state of individual SSA at Ny-Ålesund, Svalbard, in summertime. Individual fresh SSA contained cubic NaCl coated by certain amounts of MgCl2 and CaSO4. Individual partially aged SSA contained irregular NaCl coated by a mixture of NaNO3, Na2SO4, Mg(NO3)2, and MgSO4. The comparison suggests the hydrophilic MgCl2 coating in fresh SSA likely intrigued the heterogeneous reactions at the beginning of SSA and acidic gases. Individual fully aged SSA normally had Na2SO4 cores and an amorphous coating of NaNO3. Elemental mappings of individual SSA particles revealed that as the particles ageing Cl gradually decreased, the C, N, O, and S content increased. 12C- mapping from nanoscale secondary ion mass spectrometry indicates that organic matter increased in the aged SSA compared with the fresh SSA. 12C- line scan further shows that organic matter was mainly concentrated on the aged SSA surface. These new findings indicate that this mixture of organic matter and NaNO3 on particle surfaces likely determines their hygroscopic and optical properties. These abundant SSA as reactive surfaces adsorbing inorganic and organic acidic gases can shorten acidic gas lifetime and influence the possible gaseous reactions in the Arctic atmosphere, which need to be incorporated into atmospheric chemical models in the Arctic troposphere.

  9. Natural (15)N Abundance in Key Amino Acids from Lamb Muscle: Exploring a New Horizon in Diet Authentication and Assessment of Feed Efficiency in Ruminants.

    PubMed

    Cantalapiedra-Hijar, Gonzalo; Ortigues-Marty, Isabelle; Schiphorst, Anne-Marie; Robins, Richard J; Tea, Illa; Prache, Sophie

    2016-05-25

    Natural (15)N abundance (δ(15)N) varies between individual amino acids (AAs). We hypothesized that δ(15)N of nontransaminating and essential AAs ("source" AAs, such as phenylalanine) present in animal tissues could be used as a marker of dietary origin, whereas δ(15)N of transaminating AAs ("trophic" AAs, such as glutamic acid) could give more detailed insights into animal feed efficiency. Two diets based on dehydrated Lucerne pellets were tested in growing lambs, which promoted different feed efficiencies. No dietary effects were noted on δ(15)N of any AAs analyzed in lamb muscle. In addition, δ(15)N of phenylalanine was unexpectedly similar to that of glutamic acid, suggesting that δ(15)N of AAs is significantly derived from the metabolism of the rumen microbiota and, thus, are not suited for diet authentication in ruminants. In contrast, the δ(15)N of transaminating AAs facilitates an improved prediction of animal feed efficiency compared to the classical isotopic bulk N analysis.

  10. [Cd uptake in rice cultivars and Cd fractions in soil treated with organic acids and EDTA].

    PubMed

    Zhang, Hai-Bo; Li, Yang-Rui; Xu, Wei-Hong; Chen, Gui-Qing; Wang, Hui-Xian; Han, Gui-Qi; Zhang, Xiao-Jing; Xiong, Zhi-Ting; Zhang, Jin-Zhong; Xie, De-Ti

    2011-09-01

    A pot experiment was conducted to examine the yield, quality and cadmium (Cd) uptake in different rice cultivars, and Cd speciation in soil after exposing to Cd (0, 1 and 5 mg x kg(-1)) in the presence of organic acids and ethylenediamine tetraacetic acid (EDTA). The results showed that general increase in the yield for cultivars Xiushui63 and II you527 was observed. Yield of two rice cultivars were in order of organic acids treatment or organic acids + 1/2EDTA treatment > EDTA treatment. The exchangeable, carbonate related and ferric-manganese oxidation related Cd increased; while organic complexation Cd and residules decreased in the presence of organic acids and EDTA. Cadmium concentrations in grain, straw and roots of both cultivars markedly reduced in the presence of organic acids and EDTA. Grain Cd concentration was the lowest for plants treated with EDTA, followed by organic acids + 1/2EDTA, and the highest Cd concentration in grain was found in the treatment with organic acids. Grain Cd concentration decreased by 9.0% to 49.3% and 16.5% to 30.6% at 1 mg x kg(-1) Cd in the presence of organic acids and EDTA, and by 12.7% to 28.5% and 4.3% to 19.1% at 5 mg x kg(-1) Cd. Cadmium concentration and accumulation in plants and total Cd content in soil were higher in Xiushui63 than in that in II you527. Grain Cd concentration decreased, and yield and quality of two rice cultivars increased at the same time in the presence of organic acids + 1/2EDTA.

  11. Structure of six organic acid-base adducts from 6-bromobenzo[d]thiazol-2-amine and acidic compounds

    NASA Astrophysics Data System (ADS)

    Jin, Shouwen; Zhang, Jing; Wang, Daqi; Tao, Lin; Zhou, Mengjian; Shen, Yinyan; Chen, Quan; Lin, Zhanghui; Gao, Xingjun

    2014-05-01

    Six anhydrous organic acid-base adducts of 6-bromobenzo[d]thiazol-2-amine were prepared with organic acids as 2,4,6-trinitrophenol, salicylic acid, 3,5-dinitrobenzoic acid, 3,5-dinitrosalicylic acid, malonic acid and sebacic acid. The compounds 1-6 were characterized by X-ray diffraction analysis, IR, and elemental analysis. The melting points of all the adducts were given. Of the six adducts, 1, 3, 4, and 5 are organic salts, while 2, and 6 are cocrystals. The supramolecular arrangement in the crystals 2-6 is based on the R22(8) synthon. Analysis of the crystal packing of 1-6 suggests that there are strong NH⋯O, OH⋯N, and OH⋯O hydrogen bonds (charge assisted or neutral) between acid and base components in the supramolecular assemblies. When the hydroxyl group is present in the ortho position of the carboxy, the intramolecular S6 synthon is present, as expected. Besides the classical hydrogen bonding interactions, other noncovalent interactions also play important roles in structure extension. Due to the synergetic effect of these weak interactions, compounds 1-6 display 1D-3D framework structure.

  12. Sorption of vapors of some organic liquids on soil humic acid and its relation to partitioning of organic compounds in soil organic matter

    USGS Publications Warehouse

    Chlou, G.T.; Kile, D.E.; Malcolm, R.L.

    1988-01-01

    Vapor sorption of water, ethanol, benzene, hexane, carbon tetrachloride, 1,1,1-trichloroethane, trichloroethylene, tetrachloroethylene, and 1,2-dibromoethane on (Sanhedron) soil humic acid has been determined at room temperature. Isotherms for all organic liquids are highly linear over a wide range of relative pressure (P/P??), characteristic of the partitioning (dissolution) of the organic compounds in soil humic acid. Polar liquids exhibit markedly greater sorption capacities on soil humic acid than relatively nonpolar liquids, in keeping with the polar nature of the soil humic acid as a partition medium. The limiting sorption (partition) capacities of relatively non-polar liquids are remarkably similar when expressed in terms of volumes per unit weight of soil humic acid. The soil humic acid is found to be about half as effective as soil organic matter in sorption of relatively nonpolar organic compounds. The nearly constant limiting sorption capacity for nonpolar organic liquids with soil humic acid on a volume-to-weight basis and its efficiency in sorption relative to soil organic matter provide a basis for predicting the approximate sorption (partition) coefficients of similar compounds in uptake by soil in aqueous systems.

  13. Effect of petroleum products on the decomposition of soil organic matter as assessed by 13C natural abundance

    NASA Astrophysics Data System (ADS)

    Stelmach, Wioleta; Szarlip, Paweł; Trembaczowski, Andrzej; Bieganowski, Andrzej

    2016-04-01

    Petroleum products are common contaminants in soils due to human activities. They are toxic for microorganisms and threat their functions, including decomposition of soil organic matter (SOM). The direct estimation of altered SOM decomposition - based on the CO2 emission - is impossible after oil contamination, because oil decomposition also contributes to the CO2 release. We used the natural differences in the isotopic signature (δ13C) of SOM and of oil products to partition the total CO2 for both sources and to analyze the suppression of SOM decomposition. The dynamics of 13C fractionation during the mineralization of gasoline and diesel was measured during 42 days. The 13C fractionation varied between -8.8‰ and +3.6‰ within the first 10 days, and stabilized thereafter at about -5.3‰ for gasoline and +3.2‰ for diesel. These 13C fractionations and δ13C values of CO2 emitted from the soil were used for correct partitioning of the total CO2. Contamination with gasoline reduced the CO2 efflux from SOM decomposition by a factor of 25 (from 151 to 6 mg C-CO2 kg-1 soil during 42 days). The negative effect of diesel was much lower: the CO2 efflux from SOM was decreased by less than a factor of 2. The strong effect of gasoline versus diesel reflects the lower absorption of gasoline to mineral particles and the development of a thin film on water surfaces, leading to toxicity for microorganisms. We conclude that the small differences of 13C of SOM and of organic pollutants can be used to partition CO2 fluxes and analyze pollutant effects on SOM decomposition.

  14. Dicarboxylic acids and water-soluble organic carbon in aerosols in New Delhi, India, in winter: Characteristics and formation processes

    NASA Astrophysics Data System (ADS)

    Miyazaki, Yuzo; Aggarwal, Shankar G.; Singh, Khem; Gupta, Prabhat K.; Kawamura, Kimitaka

    2009-10-01

    Day- and nighttime aerosol samples were collected at an urban site in New Delhi, India, in winter 2006-2007. They were studied for low molecular weight dicarboxylic acids and related compounds, as well as total water-soluble organic carbon (TWSOC). High concentrations of diacids (up to 6.03 μg m-3), TWSOC, and OC were obtained, which are substantially higher than those previously observed at other urban sites in Asia. Daytime TWSOC/OC ratio (37%) was on average higher than that in nighttime (25%). In particular, more water-soluble OC (M-WSOC) to TWSOC ratio in daytime (50%) was twice higher than in nighttime (27%), suggesting that aerosols in New Delhi are photochemically more processed in daytime to result in more water-soluble organic compounds. Oxalic acid (C2) was found as the most abundant dicarboxylic acid, followed by succinic (C4) and malonic (C3) acids. Contributions of C2 to M-WSOC were greater (av. 8%) in nighttime than daytime (av. 3%). Positive correlations of C2 with malic acid (hC4), glyoxylic acid (ωC2), and relative humidity suggest that secondary production of C2 probably in aqueous phase is important in nighttime via the oxidation of both longer-chain diacids and ωC2. C2 also showed a positive correlation with potassium (K+) in nighttime, suggesting that the enhanced C2 concentrations are associated with biomass/biofuel burning. More tight, positive correlation between less water-soluble OC (L-WSOC) and K+ was found in both day- and nighttime, suggesting that L-WSOC, characterized by longer chain and/or higher molecular weight compounds, is significantly influenced by primary emissions from biomass/biofuel burning.

  15. Concentration and fractionation of hydrophobic organic acid constituents from natural waters by liquid chromatography

    USGS Publications Warehouse

    Thurman, E.M.; Malcolm, R.L.

    1979-01-01

    A scheme is presented which used adsorption chromatography with pH gradient elution and size-exclusion chromatography to concentrate and separate hydrophobic organic acids from water. A review of chromatographic processes involved in the flow scheme is also presented. Organic analytes which appear in each aqueous fraction are quantified by dissolved organic carbon analysis. Hydrophobic organic acids in a water sample are concentrated on a porous acrylic resin. These acids usually constitute approximately 30-50 percent of the dissolved organic carbon in an unpolluted water sample and are eluted with an aqueous eluent (dilute base). The concentrate is then passed through a column of polyacryloylmorpholine gel, which separates the acids into high- and low-molecular-weight fractions. The high- and low-molecular-weight eluates are reconcentrated by adsorption chromatography, then are eluted with a pH gradient into strong acids (predominately carboxylic acids) and weak acids (predominately phenolic compounds). For standard compounds and samples of unpolluted waters, the scheme fractionates humic substances into strong and weak acid fractions that are separated from the low molecular weight acids. A new method utilizing conductivity is also presented to estimate the acidic components in the methanol fraction.

  16. Changes in abundance of an abscisic acid-responsive, early cysteine-labeled metallothionein transcript during pollen embryogenesis in bread wheat (Triticum aestivum).

    PubMed

    Reynolds, T L; Crawford, R L

    1996-12-01

    A clone for an embryoid-abundant, early cysteine-labeled metallothionein (EcMt) gene has been isolated from a wheat pollen embryoid cDNA library. The transcript of this gene was only expressed in embryogenic microspores, pollen embryoids, and developing zygotic embryos of wheat. Accumulation of the EcMt mRNA showed a direct and positive correlation with an increase of the plant hormone, abscisic acid (ABA) in developing pollen embryoids. Treating cultures with an inhibitor of ABA biosynthesis, fluridone, suppressed not only ABA accumulation but also the appearance of the EcMt gene transcript and the ability of microspores to form embryoids. These results suggest that the EcMt gene may act as a molecular marker for pollen embryogenesis because ABA biosynthesis is accompanied by the increased expression of the EcMt transcript that coincides with the differentiation of pollen embryoids in wheat anther cultures.

  17. Use of organic acids for prevention and removal of Bacillus subtilis biofilms on food contact surfaces.

    PubMed

    Akbas, Meltem Yesilcimen; Cag, Seyda

    2016-10-01

    The efficacies of organic acid (citric, malic, and gallic acids) treatments at 1% and 2% concentrations on prevention and removal of Bacillus subtilis biofilms were investigated in this study. The analyses were conducted on microtitration plates and stainless steel coupons. The biofilm removal activities of these organic acids were compared with chlorine on both surfaces. The results showed that citric acid treatments were as powerful as chlorine treatments for prevention and removal of biofilms. The antibiofilm effects of malic acid treatments were higher than gallic acid and less than citric acid treatment. When the antibiofilm effects of these acids and chlorine on the two surfaces were compared, the prevention and removal of biofilms were measured higher on microtitration plates than those on stainless steel coupons. Higher reductions were obtained by increasing concentrations of sanitizers on 24-hour biofilm with 20-minute sanitizer treatments for removal of biofilms.

  18. Adsorption of organic acids from dilute aqueous solution onto activated carbon

    SciTech Connect

    Wang, S.W.

    1980-06-01

    The radioisotope technique was used to study the removal of organic acid contaminants from dilute aqueous solutions onto activated carbon. Acetic acid, propionic acid, n-butyric acid, n-hexanoic acid and n-heptanoic acid were studied at 278, 298, and 313/sup 0/K. Three bi-solute acid mixtures (acetic and propionic acids, acetic and butanoic acids, and propionic and butanoic acids) were studied at 278 and 298/sup 0/K. Isotherms of the single-solute systems were obtained at three different temperatures in the very dilute concentration region (less than 1% by weight). These data are very important in the prediction of bi-solute equilibrium data. A Polanyi-based competitive adsorption potential theory was used to predict the bi-solute equilibrium uptakes. Average errors between calculated and experimental data ranges from 4% to 14%. It was found that the competitive adsorption potential theory gives slightly better results than the ideal adsorbed solution theory.

  19. Purification, properties and amino acid sequence of a low-Mr abundant seed protein from pea (Pisum sativum L.).

    PubMed

    Gatehouse, J A; Gilroy, J; Hoque, M S; Croy, R R

    1985-01-01

    The seeds of pea (Pisum sativum L.) contain several proteins in the albumin solubility fraction that are significant components of total cotyledonary protein (5-10%) and are accumulated in developing seeds concurrently with storage-protein synthesis. One of these proteins, of low Mr and designated 'Psa LA', has been purified, characterized and sequenced. Psa LA has an Mr of 11000 and contains polypeptides of Mr 6000, suggesting that the protein molecules are dimeric. The amino acid sequence contains 54 residues, with a high content (10/54) of asparagine/aspartate. It has no inhibitory action towards trypsin or chymotrypsin, and is distinct from the inhibitors of those enzymes found in pea seeds, nor does it inhibit hog pancreatic alpha-amylase. The protein contains no methionine, but significant amounts of cysteine (four residues per polypeptide), suggesting a possible role as a sulphur storage protein. However, its sequence is not homologous with low-Mr (2S) storage proteins from castor bean (Ricinus communis) or rape (Brassica napus). Psa LA therefore represents a new type of low-Mr seed protein.

  20. Picoliter droplet-based digital peptide nucleic acid clamp PCR and dielectric sorting for low abundant K-ras mutations

    NASA Astrophysics Data System (ADS)

    Zhang, Huidan; Sperling, Ralph; Rotem, Assaf; Shan, Lianfeng; Heyman, John; Zhang, Yizhe; Weitz, David

    2012-02-01

    Colorectal cancer (CRC) remains the second leading cause of cancer-related mortality in the US, and the 5-year survival of metastatic CRC (mCRC) is less than 10%. Although monoclonal antibodies against epidermal growth factor receptor (EGFR) provide incremental improvements in survival, approximately 40% of mCRC patients with activating KRAS mutations won't benefit from this therapy. Peptide nucleic acid (PNA), a synthetic non-extendable oligonucleotides, can bind strongly to completely complementary wild-type KRAS by Watson-Crick base pairing and suppress its amplification during PCR, while any mutant allele will show unhindered amplification. The method is particularly suitable for the simultaneously detection of several adjoining mutant sites, just as mutations of codons 12 and 13 of KRAS gene where there are totally 12 possible mutation types. In this work, we describe the development and validation of this method, based on the droplet-based digital PCR. Using a microfluidic system, single target DNA molecule is compartmentalized in microdroplets together with PNA specific for wild-type KRAS, thermocycled and the fluorescence of each droplet was detected, followed by sorting and sequencing. It enables the precise determination of all possible mutant KRAS simultaneously, and the precise quantification of a single mutated KRAS in excess background unmutated KRAS.

  1. Abundance and sources of hydrophilic and hydrophobic water-soluble organic carbon at an urban site in Korea in summer.

    PubMed

    Park, Seung Shik; Kim, Ja-Hyun; Jeong, Jae-Uk

    2012-01-01

    In this study, the characteristics of total water-soluble organic carbon (WSOC) and isolated WSOC fractions were examined to gain a better understanding of the pathway of organic aerosol production. 24 h PM(2.5) samples were collected during the summer (July 28-August 28, 2009) at an urban site in Korea. A glass column filled with XAD7HP resin was used to separate the filtered extracts into hydrophilic (WSOC(HPI)) and hydrophobic (WSOC(HPO)) fractions. The origins of air mass pathways arriving at the sampling site were mostly classified into three types, those originating over the East Sea of Korea that passed over the eastern inland urban and industrial regions (type I); those from the marine (western/southwestern/southern marine) and passed over the national industrial complex regions (type II); and those from northeastern China that passed through North Korea and metropolitan areas of South Korea (type III). Measurements showed an increase in the average WSOC fraction of total OC from the type II to III air mass (53 to 64%) periods. Also, higher SO(4)(2-)/SO(x) (=SO(2) + SO(4)(2-)) was observed in the type III air mass (0.70) than those in the types I (0.49) and II (0.43). According to the average values of WSOC/OC and SO(4)(2-)/SO(x), measurements suggest that the aerosols collected during the type III air mass period were more aged or photo-chemically processed than those during the types I and II air mass periods. The relationship between the SO(4)(2-)/SO(x) and WSOC/OC (R(2) = 0.64) suggests that a significant fraction of the observed WSOC at the site could be formed by an oxidation process similar to SO(4)(2-) aerosols, probably the oxidation process using OH radicals, or in-cloud processing. The photochemical production of WSOC(HPO) was also observed to significantly contribute to the total OC.

  2. Microbial Substrate Usage Indicated by C-14 Contents of Phospholipid Fatty Acids From Soil Organic Matter

    NASA Astrophysics Data System (ADS)

    Rethemeyer, J.; Nadeau, M. J.; Grootes, P. M.; Kramer, C.; Gleixner, G.

    2004-05-01

    Phospholipid fatty acids (PLFA's) are generally associated with viable (bacterial) cell membranes. They are thought to be short-lived under normal soil conditions. We compare the C-14 levels in PLFA's obtained from soil samples from the,clean" experimental site at Rotthalmünster (Germany) with those from the agricultural research station at Halle (Germany), where the soil is contaminated with,old" carbon from lignite mining and industry. The most abundant PLFA's were isolated via preparative capillary gas chromatography of their methyl-esters at the Max-Planck Institute, Jena, and their C-14 concentration was determined via accelerator mass spectrometry at the Leibniz-Labor, Kiel. The C-14 levels of three mono-unsaturated fatty acids (n-C17:1, n-C18:1 (and n-C16:1)) are not statistically significant different from those of the contemporaneous atmosphere, indicating these fatty acids were derived from fresh plant material. C-14 levels significantly above those of the atmosphere in three saturated fatty acids (i/a-C15:0, n-C16:0 and cy-C18:0) from the surface soil of Rotthalmünster must derive from carbon fixed from the atmosphere several years earlier, when levels of bomb-C-14, remaining from the atmospheric nuclear weapons tests, especially of the early 1960's, were still higher. Lower C-14 levels in the same compounds from the Halle surface soil indicate the incorporation of "old" contaminant carbon. A below- atmospheric C-14 concentration in n-C18:0 in Rotthalmünster surface soil may reflect the partial incorporation of carbon from older, pre-bomb times. The C-14 concentrations show these PLFA's were synthesized predominantly from recent to sub-recent photosynthetic compounds, while the significant differences in C-14 concentration, observed between the PLFA's, indicate their production from soil organic matter fractions of different (recent) age and C-14 content. The Halle results show "old" carbon may be incorporated into PLFA's and thus reenter the soil

  3. Protective effects of organic acids on survival of Escherichia coli O157:H7 in acidic environments.

    PubMed

    Bjornsdottir, K; Breidt, F; McFeeters, R F

    2006-01-01

    Outbreaks of disease due to acid-tolerant bacterial pathogens in apple cider and orange juice have raised questions about the safety of acidified foods. Using gluconic acid as a noninhibitory low-pH buffer, we investigated the killing of Escherichia coli O157:H7 strains in the presence or absence of selected organic acids (pH of 3.2), with ionic strength adjusted to 0.60 to 0.68. During a 6-h exposure period in buffered solution (pH 3.2), we found that a population of acid-adapted E. coli O157:H7 strains was reduced by 4 log cycles in the absence of added organic acids. Surprisingly, reduced lethality for E. coli O157:H7 was observed when low concentrations (5 mM) of fully protonated acetic, malic, or l-lactic acid were added. Only a 2- to 3-log reduction in cell counts was observed, instead of the 4-log reduction attributed to pH effects in the buffered solution. Higher concentrations of these acids at the same pH aided in the killing of the E. coli cells, resulting in a 6-log or greater reduction in cell numbers. No protective effect was observed when citric acid was added to the E. coli cells. d-Lactic acid had a greater protective effect than other acids at concentrations of 1 to 20 mM. Less than a 1-log decrease in cell numbers occurred during the 6-h exposure to pH 3.2. To our knowledge, this is the first report of the protective effect of organic acids on the survival of E. coli O15:H7 under low-pH conditions.

  4. Identification of urine organic acids for the detection of inborn errors of metabolism using urease and gas chromatography-mass spectrometry (GC-MS).

    PubMed

    Lo, Stanley F; Young, Velta; Rhead, William J

    2010-01-01

    A patient suspected of an inborn error of metabolism will commonly have urine organic acid analysis performed as part of their workup. The traditional urine organic acid method involves extraction of the acidic fraction from urine samples using an organic solvent, derivatization of extracted compounds, and identification using gas chromatography-mass spectrometry (GC-MS). Unfortunately, the extraction step results in the loss of many neutral and positively charged compounds, which may be of interest to metabolic physicians and biochemical geneticists. By replacing the traditional extraction step with an enzymatic treatment of the sample with urease, an abundance of organic molecules are available for separation and quantitation by GC-MS. The urease method is a useful adjunct to newborn screening follow-up and it has the additional benefit of being able to identify many classes of biochemical compounds, such as amino acids, acylglycines, neurotransmitters, and carbohydrates. The method below describes the urease treatment, derivatization, and the organic acids, and other biochemical metabolites that can be identified.

  5. Effect of heavy metals and organic matter on root exudates (low molecular weight organic acids) of herbaceous species: An assessment in sand and soil conditions under different levels of contamination.

    PubMed

    Montiel-Rozas, M M; Madejón, E; Madejón, P

    2016-09-01

    Bioavailability of heavy metals can be modified by different root exudates. Among them, low molecular weight organic acids (LMWOAs) play an important role in this process. Three plant species (Poa annua, Medicago polymorpha and Malva sylvestris), potentially used for phytoremediation, have been assessed for both metal uptake and LMWOAs excretion in contaminated environments with different concentrations of Cd, Cu and Zn. The experiments have been carried out in washed sand and in three contaminated soils where two organic amendments were added (biosolid compost and alperujo compost). The most abundant LMWOAs excreted by all studied plants were oxalic and malic acids, although citric and fumaric acids were also detected. The general tendency was that plants responded to an increase of heavy metal stress releasing higher amounts of LMWOAs. This is an efficient exclusion mechanism reducing the metal uptake and allowing the plant growth at high levels of contamination. In the experiment using wash sand as substrate, the organic acids composition and quantity depended mainly on plant species and metal contamination. M. polymorpha was the species that released the highest concentrations of LMWOAs, both in sand and in soils with no amendment addition, whereas a decrease of these acids was observed with the addition of amendments. Our results established a clear effect of organic matter on the composition and total amount of LMWOAs released. The increase of organic matter and nutrients, through amendments, improved the soil quality reducing phytotoxicity. As a result, organic acids exudates decreased and were solely composed of oxalic acid (except for M. polymorpha). The release of LMWOAs has proved to be an important mechanism against heavy metal stress, unique to each species and modifiable by means of organic amendment addition.

  6. [Simultaneous determination of organic acids and saccharides in lactic acid fermentation broth from biomass using high performance liquid chromatography].

    PubMed

    Ma, Rui; Ouyang, Jia; Li, Xin; Lian, Zhina; Cai, Cong

    2012-01-01

    Abstract: A high performance liquid chromatographic method for the simultaneous determination of organic acids and saccharides in lactic acid fermentation broth from biomass was developed. A Bio-Rad Aminex HPX-87H column was used at 55 degrees C. The mobile phase was 5 mmol/L sulfuric acid solution at a flow rate of 0.6 mL/min. The samples were detected by a refractive index detector (RID). The results showed that six organic acids and three saccharides in fermentation broth were completely separated and determined in 17 min. The linear correlation coefficients were above 0.999 8 in the range of 0.15-5.19 g/L. Under the optimized conditions, the recoveries of the organic acids and saccharides in Rhizopus oryzae fermentation broth at two spiked levels were in the range of 96.91%-103.11% with the relative standard deviations (RSDs, n = 6) of 0.81%-4.61%. This method is fast and accurate for the quantitative analysis of the organic acids and saccharides in microbial fermentation broths.

  7. 15N natural abundance during early and late succession in a middle-European dry acidic grassland.

    PubMed

    Beyschlag, W; Hanisch, S; Friedrich, S; Jentsch, A; Werner, C

    2009-09-01

    delta(15)N and total nitrogen content of above- and belowground tissues of 13 plant species from two successional stages (open pioneer community and ruderal grass stage) of a dry acidic grassland in Southern Germany were analysed, in order to evaluate whether resource use partitioning by niche separation and N input by N(2)-fixing legumes are potential determinants for species coexistence and successional changes. Within each stage, plants from plots with different legume cover were compared. Soil inorganic N content, total plant biomass and delta(15)N values of bulk plant material were significantly lower in the pioneer stage than in the ruderal grass community. The observed delta(15)N differences were rather species- than site-specific. Within both stages, there were also species-specific differences in isotopic composition between above- and belowground plant dry matter. Species-specific delta(15)N signatures may theoretically be explained by (i) isotopic fractionation during microbial-mediated soil N transformations; (ii) isotopic fractionation during plant N uptake or fractionation during plant-mycorrhiza transfer processes; (iii) differences in metabolic pathways and isotopic fractionation within the plant; or (iv) partitioning of available N resources (or pools) among plant groups or differential use of the same resources by different species, which seems to be the most probable route in the present case. A significant influence of N(2)-fixing legumes on the N balance of the surrounding plant community was not detectable. This was confirmed by the results of an independent in situ removal experiment, showing that after 3 years there were no measurable differences in the frequency distribution between plots with and without N(2)-fixing legumes.

  8. Development of gas chromatography analysis of fatty acids in marine organisms.

    PubMed

    Tang, Baokun; Row, Kyung Ho

    2013-08-01

    The gas chromatographic analysis of fatty acids has attracted considerable interest. In this analysis, the common derivatives of fatty acids, such as fatty acid methyl esters, can be detected using a flame ionization detector and the mass spectra can indicate the true structure of fatty acids. This paper reviews gas chromatographic methods for obtaining fatty acids from marine organisms. The stationary phase and detector for applications in gas chromatography are discussed. This article also reviews the components of fatty acids in marine animals, marine plants and marine microorganisms.

  9. Chemical equilibrium of minced turkey meat in organic acid solutions.

    PubMed

    Goli, T; Abi Nakhoul, P; Zakhia-Rozis, N; Trystram, G; Bohuon, P

    2007-02-01

    The distribution of acid (HA), anions (A(-)), free protons (H(3)O(+)) and bound protons (H(b)), in homogenized turkey meat was evaluated at various meat/water mass ratios of (1/4-1/10) during titration with acetic acid (0.25N) or lactic acid (0.2N). H(b) concentration was determined by titration with hydrochloric acid (0.075N) and a correlation for [H(b)]=f(pH) was proposed. A procedure was used to calculate the fractions of the various species in equilibrium, starting from an initial acid concentration in a meat/water system and assuming the accuracy of the pK(a) value of the pure weak acids despite the chemical complexity of meat. Calculated results were in very good agreement (±0.15) with experimental pH values, whatever the acid, meat batch or meat/water mass ratios used. Less than 1% of the total protons were free (H(3)O(+)) and determined the meat pH.

  10. Model-measurement comparison of functional group abundance in α-pinene and 1,3,5-trimethylbenzene secondary organic aerosol formation

    NASA Astrophysics Data System (ADS)

    Ruggeri, Giulia; Bernhard, Fabian A.; Henderson, Barron H.; Takahama, Satoshi

    2016-07-01

    Secondary organic aerosol (SOA) formed by α-pinene and 1,3,5-trimethylbenzene photooxidation under different NOx regimes is simulated using the Master Chemical Mechanism v3.2 (MCM) coupled with an absorptive gas-particle partitioning module. Vapor pressures for individual compounds are estimated with the SIMPOL.1 group contribution model for determining apportionment of reaction products to each phase. We apply chemoinformatic tools to harvest functional group (FG) composition from the simulations and estimate their contributions to the overall oxygen to carbon ratio. Furthermore, we compare FG abundances in simulated SOA to measurements of FGs reported in previous chamber studies using Fourier transform infrared spectroscopy. These simulations qualitatively capture the dynamics of FG composition of SOA formed from both α-pinene and 1,3,5-trimethylbenzene in low-NOx conditions, especially in the first hours after start of photooxidation. Higher discrepancies are found after several hours of simulation; the nature of these discrepancies indicates sources of uncertainty or types of reactions in the condensed or gas phase missing from current model implementation. Higher discrepancies are found in the case of α-pinene photooxidation under different NOx concentration regimes, which are reasoned through the domination by a few polyfunctional compounds that disproportionately impact the simulated FG abundance in the aerosol phase. This manuscript illustrates the usefulness of FG analysis to complement existing methods for model-measurement evaluation.

  11. Stable carbon isotope measurements of atmospheric organic acids in Los Angeles, California

    SciTech Connect

    Sakugawa, H.; Kaplan, I.R.

    1995-06-15

    Atmospheric organic acids are ubiquitous constituents of urban smog and haze and are also present in the atmospheres of rural and largely uninhabited areas (e.g., the Amazon Rain Forest Basin). The authors report here source characterization of atmospheric organic acids in Los Angeles by measurements of their stable carbon isotopic ratios, e.g., {sup 13}C/{sup 12}C({delta}{sup 13}C). The study was performed by separating formic and acetic acids using ion chromatography exclusion (ICE) and isolating milligram quantities of individual organic acids from atmospheric rain samples. Authentic reference samples of formic and acetic acids were used to determine that only a negligible isotope fractionation of {delta}{sup 13}C value occurs after the ICE separation. During 1991-1992, rainwaters were collected in Los Angeles to isolate formic and acetic acids for the isotope measurements. Results presented in this paper demonstrate a significant isotopic difference between the mean {delta}{sup 13}C value for acetic acid ({minus}20.5{per_thousand}) and formic acid ({minus}30.1{per_thousand}). The authors conclude from these results that the formic acid is derived from mixing of formic acid from direct emissions with the acid formed by secondary oxidation processes in the atmosphere, most probably from aldehydes, whereas acetic acid originates only from direct source emissions. 26 refs., 1 fig., 2 tabs.

  12. Stable carbon isotope measurements of atmospheric organic acids in Los Angeles, California

    NASA Astrophysics Data System (ADS)

    Sakugawa, Hiroshi; Kaplan, Isaac R.

    Atmospheric organic acids are ubiquitous constituents of urban smog and haze and are also present in the atmospheres of rural and largely uninhabited areas (e.g., the Amazon Rain Forest Basin). We report here source characterization of atmospheric organic acids in Los Angeles by measurements of their stable carbon isotopic ratios, e.g., 13C/12C(δ13C). The study was performed by separating formic and acetic acids using ion chromatography exclusion (ICE) and isolating milligram quantities of individual organic acids from atmospheric rain samples. Authentic reference samples of formic and acetic acids were used to determine that only a negligible isotope fractionation of δ13C value occurs after the ICE separation. During 1991-1992, rainwaters were collected in Los Angeles to isolate formic and acetic acids for the isotope measurements. Results presented in this paper demonstrate a significant isotopic difference between the mean δ13C value for acetic acid (-20.5‰) and formic acid (-30.1‰). We conclude from these results that the formic acid is derived from mixing of formic acid from direct emissions with the acid formed by secondary oxidation processes in the atmosphere, most probably from aldehydes, whereas acetic acid originates only from direct source emissions.

  13. Kinetic studies of the strengthening effect on liquid hot water pretreatments by organic acids.

    PubMed

    Lyu, Huisheng; Lv, Chunliu; Zhang, Minhua; Liu, Jiatao; Meng, Fanmei; Geng, Zhong Feng

    2017-03-22

    The liquid hot water (LHW) pretreatments would be accelerated by the organic acids produced from the process. In the study, the organic acids included not only acetic acid but also lactic acid during LHW hydrolysis of reeds, at 180-220°C and for 15-135min. The lactic acid was presumably produced from xylose degradation in the pretreatment process. The different organic acids, such as acetic acid, lactic acid and acetic-lactic acids, were used to strengthen the LHW pretreatments for increasing xylose production. Moreover, the work presented kinetic models of xylose and hemicellulose at different conditions, considering the generation of lactic acid. The experimental and kinetic results both indicated that acetic-lactic acids had synergistic catalytic effect on the reaction, which could not only inhibit the degradation of xylose, but also promote the hydrolysis of hemicellulose. Besides, the highest concentration of xylose of 7.323g/L was obtained at 200°C, for 45min and with 1wt% acetic-lactic acids.

  14. Organosulfates and organic acids in Arctic aerosols: speciation, annual variation and concentration levels

    NASA Astrophysics Data System (ADS)

    Hansen, A. M. K.; Kristensen, K.; Nguyen, Q. T.; Zare, A.; Cozzi, F.; Nøjgaard, J. K.; Skov, H.; Brandt, J.; Christensen, J. H.; Ström, J.; Tunved, P.; Krejci, R.; Glasius, M.

    2014-02-01

    Sources, composition and occurrence of secondary organic aerosols (SOA) in the Arctic were investigated at Zeppelin Mountain, Svalbard, and Station Nord, northeast Greenland, during the full annual cycle of 2008 and 2010 respectively. We focused on the speciation of three types of SOA tracers: organic acids, organosulfates and nitrooxy organosulfates from both anthropogenic and biogenic precursors, here presenting organosulfate concentrations and compositions during a full annual cycle and chemical speciation of organosulfates in Arctic aerosols for the first time. Aerosol samples were analysed using High Performance Liquid Chromatography coupled to a quadrupole Time-of-Flight mass spectrometer (HPLC-q-TOF-MS). A total of 11 organic acids (terpenylic acid, benzoic acid, phthalic acid, pinic acid, suberic acid, azelaic acid, adipic acid, pimelic acid, pinonic acid, diaterpenylic acid acetate (DTAA) and 3-methyl-1,2,3-butanetricarboxylic acid (MBTCA)), 12 organosulfates and one nitrooxy organosulfate were identified at the two sites. Six out of the 12 organosulfates are reported for the first time. Concentrations of organosulfates follow a distinct annual pattern at Station Nord, where high concentration were observed in late winter and early spring, with a mean total concentration of 47 (±14) ng m-3, accounting for 7 (±2)% of total organic matter, contrary to a considerably lower organosulfate mean concentration of 2 (±3) ng m-3 (accounting for 1 (±1)% of total organic matter) observed during the rest of the year. The organic acids followed the same temporal trend as the organosulfates at Station Nord; however the variations in organic acid concentrations were less pronounced, with a total mean organic acid concentration of 11.5 (±4) ng m-3 (accounting for 1.7 (±0.6)% of total organic matter) in late winter and early spring, and 2.2 (±1) ng m-3 (accounting for 0.9 (±0.4)% of total organic matter) during the rest of the year. At Zeppelin Mountain

  15. The non-participation of organic sulphur in acid mine drainage generation

    USGS Publications Warehouse

    Casagrande, D.J.; Finkelman, R.B.; Caruccio, F.T.

    1989-01-01

    Acid mine drainage is commonly associated with land disturbances that encounter and expose iron sulphides to oxidising atmospheric conditions. The attendant acidic conditions solubilise a host of trace metals. Within this flow regime the potential exists to contaminate surface drinking water supplies with a variety of trace materials. Accordingly, in evaluating the applications for mines located in the headwaters of water sheds, the pre-mining prediction of the occurrence of acid mine drainage is of paramount importance. There is general agreement among investigators that coal organic sulphur is a nonparticipant in acid mine drainage generation; however, there is no scientific documentation to support this concensus. Using simulated weathering, kinetic, mass balance, petrographic analysis and a peroxide oxidation procedure, coal organic sulphur is shown to be a nonparticipant in acid mine drainage generation. Calculations for assessing the acid-generating potential of a sedimentary rock should not include organic sulphur content. ?? 1989 Sciences and Technology Letters.

  16. Retention and utilization of amino acids in piglets fed ad libitum or restrictively diets supplemented with organic acids.

    PubMed

    Walz, O P; Pallauf, J

    1997-01-01

    In a metabolic trial 4 groups of 8 piglets of 5 kg weight each were kept individually for 45 days (final weight 23 kg) and fed a practical diet. At the beginning of the experiment the body amino acid contents of an additional group of 8 piglets were determined by carcass analysis, and at the end of the experiment the body amino acid contents of the 4 test group piglets (A = control fed ad libitum, B and C = supplement of 1.5% fumaric acid fed ad libitum or restrictively, D = supplement of 1.5% citric acid fed ad libitum) were also analysed. The amino acid retention during the experimental period was determined by difference. The supplements of fumaric or citric acid did not influence the amount of the amino acid retention. The quotient of amino acid retention to amino acid consumed or the "productive amino acid value" was calculated and the maintenance requirements of essential amino acids for piglets were used to estimate the productive amino acid value for both retention and maintenance. The mean amino acid retention amounted to about 56 g/d, i.e. 3.49 g/kg W0.75.d of essential amino acids. The essential amino acid requirements for maintenance was 2.0 g, i.e. 0.29 g/kg W0.75.d, showing a variation of 4% (Leu) to 20% (Met+Cys) when related to the amount of the corresponding amino acid retention. With regard to the amino acid pattern for retention of the nutritionally most important amino acids, the following ratios were found: Lys, 100 (6.27 g/16 g N): Met+Cys, 48 (3.03 g): Thr, 56 (3.49 g): Trp, 13 (0.80 g). The productive amino acid values ranged from 40% (Trp), 55% (Thr), 66% (Met) to 80% (Lys). Under the conditions investigated, neither the supplements of organic acids nor the feed restriction influenced the amino acid utilization.

  17. Anaerobic organic acid metabolism of Candida zemplinina in comparison with Saccharomyces wine yeasts.

    PubMed

    Magyar, Ildikó; Nyitrai-Sárdy, Diána; Leskó, Annamária; Pomázi, Andrea; Kállay, Miklós

    2014-05-16

    Organic acid production under oxygen-limited conditions has been thoroughly studied in the Saccharomyces species, but practically never investigated in Candida zemplinina, which seems to be an acidogenic species under oxidative laboratory conditions. In this study, several strains of C. zemplinina were tested for organic acid metabolism, in comparison with Saccharomyces cerevisiae, Saccharomyces uvarum and Candida stellata, under fermentative conditions. Only C. stellata produced significantly higher acidity in simple minimal media (SM) with low sugar content and two different nitrogen sources (ammonia or glutamic acid) at low level. However, the acid profile differed largely between the Saccharomyces and Candida species and showed inverse types of N-dependence in some cases. Succinic acid production was strongly enhanced on glutamic acid in Saccharomyces species, but not in Candida species. 2-oxoglutarate production was strongly supported on ammonium nitrogen in Candida species, but remained low in Saccharomyces. Candida species, C. stellata in particular, produced more pyruvic acid regardless of N-sources. From the results, we concluded that the anaerobic organic acid metabolisms of C. zemplinina and C. stellata are different from each other and also from that of the Saccharomyces species. In the formation of succinic acid, the oxidative pathway from glutamic acid seems to play little or no role in C. zemplinina. The reductive branch of the TCA cycle, however, produces acidic intermediates (malic, fumaric, and succinic acid) in a level comparable with the production of the Saccharomyces species. An unidentified organic acid, which was produced on glutamic acid only by the Candida species, needs further investigation.

  18. Organic matter in sediment layers of an acidic mining lake as assessed by lipid analysis. Part II: Neutral lipids.

    PubMed

    Poerschmann, Juergen; Koschorreck, Matthias; Górecki, Tadeusz

    2017-02-01

    Natural neutralization of acidic mining lakes is often limited by organic matter. The knowledge of the sources and degradability of organic matter is crucial for understanding alkalinity generation in these lakes. Sediments collected at different depths (surface sediment layer from 0 to 1 cm and deep sediment layer from 4 to 5cm) from an acidic mining lake were studied in order to characterize sedimentary organic matter based on neutral signature markers. Samples were exhaustively extracted, subjected to pre-chromatographic derivatizations and analyzed by GC/MS. Herein, molecular distributions of diagnostic alkanes/alkenes, terpenes/terpenoids, polycyclic aromatic hydrocarbons, aliphatic alcohols and ketones, sterols, and hopanes/hopanoids were addressed. Characterization of the contribution of natural vs. anthropogenic sources to the sedimentary organic matter in these extreme environments was then possible based on these distributions. With the exception of polycyclic aromatic hydrocarbons, combined concentrations across all marker classes proved higher in the surface sediment layer as compared to those in the deep sediment layer. Alkane and aliphatic alcohol distributions pointed to predominantly allochthonous over autochthonous contribution to sedimentary organic matter. Sterol patterns were dominated by phytosterols of terrestrial plants including stigmasterol and β-sitosterol. Hopanoid markers with the ββ-biohopanoid "biological" configuration were more abundant in the surface sediment layer, which pointed to higher bacterial activity. The pattern of polycyclic aromatic hydrocarbons pointed to prevailing anthropogenic input. Pyrolytic makers were likely to due to atmospheric deposition from a nearby former coal combustion facility. The combined analysis of the array of biomarkers provided new insights into the sources and transformations of organic matter in lake sediments.

  19. Bioremediation of Acidic and Metalliferous Drainage (AMD) through organic carbon amendment by municipal sewage and green waste.

    PubMed

    McCullough, Clint D; Lund, Mark A

    2011-10-01

    Pit lakes (abandoned flooded mine pits) represent a potentially valuable water resource in hot arid regions. However, pit lake water is often characterised by low pH with high dissolved metal concentrations resulting from Acidic and Metalliferous Drainage (AMD). Addition of organic matter to pit lakes to enhance microbial sulphate reduction is a potential cost effective remediation strategy. However, cost and availability of suitable organic substrates are often limiting. Nevertheless, large quantities of sewage and green waste (organic garden waste) are often available at mine sites from nearby service towns. We treated AMD pit lake water (pH 2.4) from tropical, North Queensland, Australia, with primary-treated sewage sludge, green waste, and a mixture of sewage and green waste (1:1) in a controlled microcosm experiment (4.5 L). Treatments were assessed at two different rates of organic loading of 16:1 and 32:1 pit water:organic matter by mass. Combined green waste and sewage treatment was the optimal treatment with water pH increased to 5.5 in only 145 days with decreases of dissolved metal concentrations. Results indicated that green waste was a key component in the pH increase and concomitant heavy metal removal. Water quality remediation was primarily due to microbially-mediated sulphate reduction. The net result of this process was removal of sulphate and metal solutes to sediment mainly as monosulfides. During the treatment process NH(3) and H(2)S gases were produced, albeit at below concentrations of concern. Total coliforms were abundant in all green waste-treatments, however, faecal coliforms were absent from all treatments. This study demonstrates addition of low-grade organic materials has promise for bioremediation of acidic waters and warrants further experimental investigation into feasibility at higher scales of application such as pit lakes.

  20. The Effect of Freezing on Thylakoid Membranes in the Presence of Organic Acids

    PubMed Central

    Santarius, Kurt A.

    1971-01-01

    The effect of salts of organic acids on washed and non-washed chloroplast membranes during freezing was investigated. Thylakoids were isolated from spinach leaves (Spinacia oleracea L.) and, prior to freezing, salts of various organic acids or inorganic salts or both were added. Freezing occurred for 3 to 4 hours at −25 C. After thawing membrane integrity was investigated by measuring the activity of cyclic photophosphorylation. At very low NaCl levels (1 to 3 mm, washed thylakoids) salts of organic acids either could not prevent membrane inactivation in the course of freezing (succinate) or were effective only at relatively high concentrations (0.1 m or more of acetate, pyruvate, malate, tartrate, citrate). If NaCl was present at higher concentrations (e.g., 0.1 m) some organic acids, e.g. succinate, malate, tartrate, and citrate, were able to protect frost-sensitive thylakoids at surprisingly low concentrations (10 to 20 mm). Other inorganic salts such as KCl, MgCl2, NaNO3 could also induce protection by organic acids which otherwise were ineffective or poorly effective. For effective protection, a more or less constant ratio between inorganic salt and organic acid or between two or more organic acids had to be maintained. Departure to either side from the optimal ratio led to progressive inactivation. The unspecificity of the protective effect of organic acids suggests that these compounds protect colligatively. There are also indications that, in addition, more specific interaction with the membranes contributes to protection. At temperatures above the freezing point, the presence of salts of organic acids decreased the rate of membrane inactivation by high electrolyte concentrations. PMID:16657754

  1. Biotechnological Production of Organic Acids from Renewable Resources.

    PubMed

    Pleissner, Daniel; Dietz, Donna; van Duuren, Jozef Bernhard Johann Henri; Wittmann, Christoph; Yang, Xiaofeng; Lin, Carol Sze Ki; Venus, Joachim

    2017-03-07

    Biotechnological processes are promising alternatives to petrochemical routes for overcoming the challenges of resource depletion in the future in a sustainable way. The strategies of white biotechnology allow the utilization of inexpensive and renewable resources for the production of a broad range of bio-based compounds. Renewable resources, such as agricultural residues or residues from food production, are produced in large amounts have been shown to be promising carbon and/or nitrogen sources. This chapter focuses on the biotechnological production of lactic acid, acrylic acid, succinic acid, muconic acid, and lactobionic acid from renewable residues, these products being used as monomers for bio-based material and/or as food supplements. These five acids have high economic values and the potential to overcome the "valley of death" between laboratory/pilot scale and commercial/industrial scale. This chapter also provides an overview of the production strategies, including microbial strain development, used to convert renewable resources into value-added products.

  2. Anaerobic microbial dissolution of lead and production of organic acids

    DOEpatents

    Francis, A.J.; Dodge, C.; Chendrayan, K.; Quinby, H.L.

    1987-04-16

    The present invention related to an anaerobic bacterial culture of Clostridium sp. ATCC No. 53464 which solubilizes lead oxide under anaerobic conditions in coal and industrial wastes and therefore presents a method of removing lead from such wastes before they are dumped into the environment. The rat of lead dissolution during logarithmic growth of the bacteria in 40 ml medium containing 3.32 ..mu..moles of lead as lead oxide was 0.042 ..mu..moles m1/sup /-/1/ hr/sup /-/1/. Dissolution of lead oxide by the bacterial isolate is due to the production of metabolites and acidity in the culture medium. The major metabolites are acetic, butyric and lactic acid. The major metabolites are acetic, butyric and lactic acid. Clostridium sp. ATCC No. 53464 can be used in the recovery of the strategic metals from ores and wastes and also for the production of lactic acid for commercial purposes. The process yields large quantities of lactic acid as well as lead complexed in a stable form with said acids. 4 figs., 3 tabs.

  3. Analysis of lipid and fatty acid composition of three species of scorpions with relation to different organs.

    PubMed

    Laino, Aldana; Mattoni, Camilo; Ojanguren-Affilastro, Andrés; Cunningham, Mónica; Fernando Garcia, C

    2015-12-01

    Within arthropods most of the information related to the type of mobilization and storage of lipids is found in insects and crustaceans. Literature is scarce with relation to scorpions. This order is a remarkably important model of the biochemistry, since it is characterized as an animal with very primitive traits which have varied minimally through time. In the present study we characterize and compare lipids and fatty acids present in three species of scorpion: Timogenes elegans, Timogenes dorbignyi, and Brachistosternus ferrugineus, focusing the study on the main organs/tissues involved in the dynamics of lipids. As found in the fat body of insects, hepatopancreas of crustaceans and midgut diverticula of spiders, the hepatopancreas of the three species studied here turned out to be the organ of lipid storage (great quantity of triacylglycerides). With relation to the hemolymph and muscles, a great quantity of phospholipids was observed, which is possibly involved in membrane formation. It is important to highlight that unlike what happens in insects, in scorpions the main circulating energetic lipid is the triacylglyceride. This lipid is found in greater proportion in the hepatopancreas of females, surely for reproduction. The fatty acid of the different organs/tissues analyzed remained constant in the three species studied with certain characteristic patterns, thus observing saturated and unsaturated most abundant fatty acids of C16 and C18. Finally, it could be observed that in T. elegans, T. dorbignyi and B. ferrugineus scorpions, there is a lack of 20:4 that generates a special condition within fatty acids of arthropods.

  4. Mineral vs. Organic Amendments: Microbial Community Structure, Activity and Abundance of Agriculturally Relevant Microbes Are Driven by Long-Term Fertilization Strategies

    PubMed Central

    Francioli, Davide; Schulz, Elke; Lentendu, Guillaume; Wubet, Tesfaye; Buscot, François; Reitz, Thomas

    2016-01-01

    Soil management is fundamental to all agricultural systems and fertilization practices have contributed substantially to the impressive increases in food production. Despite the pivotal role of soil microorganisms in agro-ecosystems, we still have a limited understanding of the complex response of the soil microbiota to organic and mineral fertilization in the very long-term. Here, we report the effects of different fertilization regimes (mineral, organic and combined mineral and organic fertilization), carried out for more than a century, on the structure and activity of the soil microbiome. Organic matter content, nutrient concentrations, and microbial biomass carbon were significantly increased by mineral, and even more strongly by organic fertilization. Pyrosequencing revealed significant differences between the structures of bacterial and fungal soil communities associated to each fertilization regime. Organic fertilization increased bacterial diversity, and stimulated microbial groups (Firmicutes, Proteobacteria, and Zygomycota) that are known to prefer nutrient-rich environments, and that are involved in the degradation of complex organic compounds. In contrast, soils not receiving manure harbored distinct microbial communities enriched in oligotrophic organisms adapted to nutrient-limited environments, as Acidobacteria. The fertilization regime also affected the relative abundances of plant beneficial and detrimental microbial taxa, which may influence productivity and stability of the agroecosystem. As expected, the activity of microbial exoenzymes involved in carbon, nitrogen, and phosphorous mineralization were enhanced by both types of fertilization. However, in contrast to comparable studies, the highest chitinase and phosphatase activities were observed in the solely mineral fertilized soil. Interestingly, these two enzymes showed also a particular high biomass-specific activities and a strong negative relation with soil pH. As many soil parameters

  5. Reduction of Cr (VI) by organic acids in the presence of Al (III).

    PubMed

    Chen, Na; Lan, Yeqing; Wang, Bo; Mao, Jingdong

    2013-09-15

    The effects of Al (III) on the reduction of Cr (VI) by three α-hydroxy acids, tartaric, malic and citric acids, were investigated through batch experiments at pH from 2.5 to 4.0 and temperatures from 25 °C to 35 °C. These reactions could be described as pseudo-zero-order with respect to Cr (VI) when the concentrations of α-hydroxy acids were greatly in excess. The transformation rates of Cr (VI) to Cr (III) in the presence of Al (III) without light were in the decreasing order of tartaric acid>malic acid>citric acid. This order suggested that the two α-hydroxyl groups in tartaric acid could play an important role in the reduction of Cr (VI) by organic acids. The possible mechanism was that the formed complex between organic acids and Al (III) significantly enhanced the reductivity of α-hydroxy acids and further led to the more complicated Cr (VI)-tartaric acid-Al (III) cyclic ester which greatly accelerated the reduction rate. The Cr (VI) reduction reaction rate increased with the decrease of pH but with the increase of Al (III) concentration, tartaric acid concentration, and temperature. As the pH decreased, the increase of [H(+)] led to an increase in {Al(III)H₂Tar₂}(+), the most active species, and thus the enhanced reduction rate.

  6. Top value platform chemicals: bio-based production of organic acids.

    PubMed

    Becker, Judith; Lange, Anna; Fabarius, Jonathan; Wittmann, Christoph

    2015-12-01

    Driven by the quest for sustainability, recent years have seen a tremendous progress in bio-based production routes from renewable raw materials to commercial goods. Particularly, the production of organic acids has crystallized as a competitive and fast-evolving field, related to the broad applicability of organic acids for direct use, as polymer building blocks, and as commodity chemicals. Here, we review recent advances in metabolic engineering and industrial market scenarios with focus on organic acids as top value products from biomass, accessible through fermentation and biotransformation.

  7. An enhanced procedure for measuring organic acids and methyl esters in PM2.5

    NASA Astrophysics Data System (ADS)

    Liu, F.; Duan, F. K.; He, K. B.; Ma, Y. L.; Rahn, K. A.; Zhang, Q.

    2015-11-01

    A solid-phase extraction (SPE) pretreatment procedure allowing organic acids to be separated from methyl esters in fine aerosol has been developed. The procedure first separates the organic acids from fatty acid methyl esters (FAMEs) and other nonacid organic compounds by aminopropyl-based SPE cartridge and then quantifies them by gas chromatography/mass spectrometry. The procedure prevents the fatty acids and dimethyl phthalate from being overestimated, and so allows us to accurately quantify the C4-C11 dicarboxylic acids (DCAs) and the C8-C30 monocarboxylic acids (MCAs). Results for the extraction of DCAs, MCAs, and AMAs in eluate and FAMEs in effluate by SAX and NH2 SPE cartridges exhibited that the NH2 SPE cartridge gave higher extraction efficiency than the SAX cartridge. The recoveries of analytes ranged from 67.5 to 111.3 %, and the RSD ranged from 0.7 to 10.9 %. The resulting correlations between the aliphatic acids and FAMEs suggest that the FAMEs had sources similar to those of the carboxylic acids, or were formed by esterifying carboxylic acids, or that aliphatic acids were formed by hydrolyzing FAMEs. Through extraction and cleanup using this procedure, 17 aromatic acids in eluate were identified and quantified by gas chromatography/tandem mass spectrometry, including five polycyclic aromatic hydrocarbon (PAH): acids 2-naphthoic, biphenyl-4-carboxylic, 9-oxo-9H-fluorene-1-carboxylic, biphenyl-4,4´-dicarboxylic, and phenanthrene-1-carboxylic acid, plus 1,8-naphthalic anhydride. Correlations between the PAH acids and the dicarboxylic and aromatic acids suggested that the first three acids and 1,8-naphthalic anhydride were secondary atmospheric photochemistry products and the last two mainly primary.

  8. Relative efficacy of organic acids and antibiotics as growth promoters in broiler chicken

    PubMed Central

    Bagal, Vikrant Laxman; Khatta, Vinod Kumar; Tewatia, Bachu Singh; Sangwan, Sandeep Kumar; Raut, Subhash Shamrao

    2016-01-01

    Aim: The objective of this study was to evaluate the effect of organic acids as replacer to antibiotics in their various combinations on feed consumption, body weight gain, and feed conversion ratio (FCR) in broiler chicks during different phases of growth. Materials and Methods: Antibiotics and organic acids were incorporated into boiler feed in different combinations to form 10 maize based test diets (T1 to T10). Each test diet was offered to four replicates of 10 birds each constituting a total of 400 birds kept for 45 days. Results: Significantly better effect in terms of body weight gain from supplementation of 1% citric acid and 1% citric acid along with antibiotic was observed throughout the entire study, whereas the effect of tartaric acid supplementation was similar to control group. Citric acid (1%) along with antibiotic supplementation showed highest feed intake during the experimental period. Significantly better FCR was observed in groups supplemented with 1% citric acid and 1% citric acid along with antibiotic followed by antibiotic along with organic acids supplemented group. Conclusion: Growth performance of birds in terms of body weight, body weight gain, and FCR improved significantly in 1% citric acid which was significantly higher than antibiotic supplemented group. 1% citric acid can effectively replace antibiotic growth promoter (chlortetracycline) without affecting growth performance of birds. PMID:27182133

  9. Firing range soils yield a diverse array of fungal isolates capable of organic acid production and Pb mineral solubilization.

    PubMed

    Sullivan, Tarah S; Gottel, Neil R; Basta, Nicholas; Jardine, Philip M; Schadt, Christopher W

    2012-09-01

    Anthropogenic sources of lead contamination in soils include mining and smelting activities, effluents and wastes, agricultural pesticides, domestic garbage dumps, and shooting ranges. While Pb is typically considered relatively insoluble in the soil environment, some fungi may potentially contribute to mobilization of heavy metal cations by means of secretion of low-molecular-weight organic acids (LMWOAs). We sought to better understand the potential for metal mobilization within an indigenous fungal community at an abandoned shooting range in Oak Ridge, TN, where soil Pb contamination levels ranged from 24 to >2,700 mg Pb kg dry soil(-1). We utilized culture-based assays to determine organic acid secretion and Pb-carbonate dissolution of a diverse collection of soil fungal isolates derived from the site and verified isolate distribution patterns within the community by 28S rRNA gene analysis of whole soils. The fungal isolates examined included both ascomycetes and basidiomycetes that excreted high levels (up to 27 mM) of a mixture of LMWOAs, including oxalic and citric acids, and several isolates demonstrated a marked ability to dissolve Pb-carbonate at high concentrations up to 10.5 g liter(-1) (18.5 mM) in laboratory assays. Fungi within the indigenous community of these highly Pb-contaminated soils are capable of LMWOA secretion at levels greater than those of well-studied model organisms, such as Aspergillus niger. Additionally, these organisms were found in high relative abundance (>1%) in some of the most heavily contaminated soils. Our data highlight the need to understand more about autochthonous fungal communities at Pb-contaminated sites and how they may impact Pb biogeochemistry, solubility, and bioavailability, thus consequently potentially impacting human and ecosystem health.

  10. Sea salt aerosols as a reactive surface for inorganic and organic acidic gases in the arctic troposphere

    NASA Astrophysics Data System (ADS)

    Chi, J. W.; Li, W. J.; Zhang, D. Z.; Zhang, J. C.; Lin, Y. T.; Shen, X. J.; Sun, J. Y.; Chen, J. M.; Zhang, X. Y.; Zhang, Y. M.; Wang, W. X.

    2015-06-01

    Sea salt aerosols (SSA) are dominant particles in the arctic atmosphere and determine the polar radiative balance. SSA react with acidic pollutants that lead to changes of physical and chemical properties of their surface, which in turn alter their hygroscopic and optical properties. Transmission electron microscopy with energy-dispersive X-ray spectrometry was used to analyze morphology, composition, size, and mixing state of individual SSA at Ny-Ålesund, Svalbard in summertime. Individual fresh SSA contained cubic NaCl coated by certain amounts of MgCl2 and CaSO4. Individual partially aged SSA contained irregular NaCl coated by a mixture of NaNO3, Na2SO4, Mg(NO3)2, and MgSO4. The comparison suggests the hydrophilic MgCl2 coating in fresh SSA likely intrigued the heterogeneous reactions at the beginning of SSA and acidic gases. Individual fully aged SSA normally had Na2SO4 cores and an amorphous coating of NaNO3. Elemental mappings of individual SSA particles revealed that as the particles ageing Cl gradually decreased but the C, N, O, and S content increased. 12C14N- mapping from nanoscale secondary ion mass spectrometry indicates that organic matter increased in the aged SSA compared with the fresh SSA. 12C14N- line scans further show that organic matter was mainly concentrated on the aged SSA surface. These new findings indicate that this mixture of organic matter and NaNO3 on particle surfaces determines their hygroscopic and optical properties. These abundant SSA, whose reactive surfaces absorb inorganic and organic acidic gases in the arctic troposphere, need to be incorporated into atmospheric chemical models.

  11. Firing Range Soils Yield a Diverse Array of Fungal Isolates Capable of Organic Acid Production and Pb Mineral Solubilization

    PubMed Central

    Sullivan, Tarah S.; Gottel, Neil R.; Basta, Nicholas; Jardine, Philip M.

    2012-01-01

    Anthropogenic sources of lead contamination in soils include mining and smelting activities, effluents and wastes, agricultural pesticides, domestic garbage dumps, and shooting ranges. While Pb is typically considered relatively insoluble in the soil environment, some fungi may potentially contribute to mobilization of heavy metal cations by means of secretion of low-molecular-weight organic acids (LMWOAs). We sought to better understand the potential for metal mobilization within an indigenous fungal community at an abandoned shooting range in Oak Ridge, TN, where soil Pb contamination levels ranged from 24 to >2,700 mg Pb kg dry soil−1. We utilized culture-based assays to determine organic acid secretion and Pb-carbonate dissolution of a diverse collection of soil fungal isolates derived from the site and verified isolate distribution patterns within the community by 28S rRNA gene analysis of whole soils. The fungal isolates examined included both ascomycetes and basidiomycetes that excreted high levels (up to 27 mM) of a mixture of LMWOAs, including oxalic and citric acids, and several isolates demonstrated a marked ability to dissolve Pb-carbonate at high concentrations up to 10.5 g liter−1 (18.5 mM) in laboratory assays. Fungi within the indigenous community of these highly Pb-contaminated soils are capable of LMWOA secretion at levels greater than those of well-studied model organisms, such as Aspergillus niger. Additionally, these organisms were found in high relative abundance (>1%) in some of the most heavily contaminated soils. Our data highlight the need to understand more about autochthonous fungal communities at Pb-contaminated sites and how they may impact Pb biogeochemistry, solubility, and bioavailability, thus consequently potentially impacting human and ecosystem health. PMID:22729539

  12. Phase equilibria and distribution constants of metal ions in diantipyryl alkane-organic acid-hydrochloric acid-water systems

    NASA Astrophysics Data System (ADS)

    Degtev, M. I.; Popova, O. N.; Yuminova, A. A.

    2014-08-01

    The ability of antipyrine and its derivatives (diantipyryl alkanes) to form separating systems in the presence of salicylic (sulfosalicylic) acid and hydrochloric acid and water is studied. The optimum volume of the organic phase, the composition of complexes, and the mechanism for the distribution of metal ions are determined, depending on the concentrations of the main components and the salting-out agent. The complex distribution and extraction constants are calculated.

  13. Screening of organic halogens and identification of chlorinated benzoic acids in carbonaceous meteorites.

    PubMed

    Schöler, Heinz F; Nkusi, Gerard; Niedan, Volker W; Müller, German; Spitthoff, Bianca

    2005-09-01

    The occurrence of halogenated organic compounds measured as a sum parameter and the evidence of chlorinated benzoic acids in four carbonaceous meteorites (Cold Bokkeveld, Murray, Murchison and Orgueil) from four independent fall events is reported. After AOX (Adsorbable organic halogen) and EOX (Extractable organic halogen) screening to quantify organically bound halogens, chlorinated organic compounds were analyzed by gas chromatography. AOX concentrations varying from 124 to 209 microg Cl/g d.w. were observed in carbonaceous meteorites. Ion chromatographic analysis of the distribution of organically bound halogens performed on the Cold Bokkeveld meteorite revealed that chlorinated and brominated organic compounds were extractable, up to 70%, whereas only trace amounts of organofluorines could be extracted. Chlorinated benzoic acids have been identified in carbonaceous meteorite extracts. Their presence and concentrations raise the question concerning the origin of halogenated, especially chlorinated, organic compounds in primitive planetary matter.

  14. Anaerobic microbial dissolution of lead and production of organic acids

    DOEpatents

    Francis, Arokiasamy J.; Dodge, Cleveland; Chendrayan, Krishnachetty; Quinby, Helen L.

    1988-01-01

    The present invention relates to an anaerobic bacterial culture of Clostridium sp. ATCC No. 53464 which solubilizes lead oxide under anaerobic conditions in coal and industrial wastes and therefore presents a method of removing lead from such wastes before they are dumped into the environment. The rate of lead dissolution during logarithmic growth of the bacteria in 40 ml medium containing 3.32 .mu.moles of lead as lead oxide was 0.042 .mu.moles ml.sup.-1 hr.sup.-1. Dissolution of lead oxide by the bacterial isolate is due to the production of metabolites and acidity in the culture medium. The major metabolites are acetic, butyric and lactic acid. Clostridium sp. ATCC No. 53464 can be used in the recovery of strategic metals from ores and wastes and also for the production of lactic acid for commercial purposes. The process yields large quantities of lactic acid as well as lead complexed in a stable form with said acids.

  15. Role of organic acids during processing to improve quality of channel catfish fillets.

    PubMed

    Fernandes, C F; Flick, G J; Cohen, J; Thomas, T B

    1998-04-01

    A microbial preparation derived from aquacultured channel catfish fillets (Ictalurus punctatus) was acidified with 0, 1, 2 and 4% (vol/vol) weak organic and held in an ice bath at 0 degree C to simulate the chilling process. Additionally, catfish fillets were sprayed under varying pressures at 15 degrees C with organic acids to evaluate the efficacy of concentrations of organic acids and spray pressures to ameliorate the microbiological quality. To determine plate counts, the dilution fluid was neutralized to pH 7.2 with 1.0 M NaOH. The aerobic plates counts of microorganisms in the chilling water were monitored over a 20-min interval. Aerobic plate counts were found on the channel catfish fillets before and after spray washing with organic acids. Plates were incubated at 35 degrees C for 48 h. The addition of organic acids tot he microbial preparation used in simulating the chilling process significantly (P < 0.05) reduced the number of bacterial surviving. The number of surviving bacteria in the chilled water decreased with increasing concentration and time of exposure to organic acids. Propionic acid had the most detrimental effect on organisms present in the microfloral preparation followed by acetic and lactic acids. Spray washing of catfish fillets with water did not significantly (P < 0.05) affect the microbial quality of fillets. However, catfish fillets sprayed with organic (lactic and propionic) acids significantly (P < 0.05) reduced the microbial counts by 10-fold. Lactic and propionic acids were not significantly (P > 0.05) different in influencing the aerobic counts of the catfish fillets.

  16. Quantitative detection of Amino Acid, Organic Acid and Sugar using an Electrode-separated Piezoelectric Quartz Crystal

    NASA Astrophysics Data System (ADS)

    Nomura, Toshiaki; Yamamura, Satoshi; Arikawa, Yukihiko

    An electrode-separated piezoelectric quartz crystal (electrode-separated PQC) is constructed with no electrode attached to either side of the quartz plate, but electrodes are separately inserted in the electrolyte solution on both sides of the quartz plate, and are connected to an oscillator. The frequency shifts due to the solution properties and the mass change on the quartz plate is just the same as for a normal piezoelectric quartz crystal (normal PQC) having two electrodes. The electrode-separated PQC will be more useful than the normal PQC because it can be made smaller, higher frequency, and then cheaper. Amino acid, organic acid and sugar are important substances in the alcoholic beverage made by fermentation, such as sake. The Amino acids were determined using electrode-separated PQC coated with chitosan in copper (II) solution. Formation of complex with chitosan on the quartz plate, Cu(II) and amino acid in the sample solution induced the frequency shift of PQC. On the other hand, using non-coated electrode-separated PQC, concentration of organic acid and sugar in the liquid were determined, because the frequency of the crystal filled with the liquid containing organic acid and sugar was shifted with the viscosity and conductivity, respectively.

  17. Microgravity Compatible Reagentless Instrumentation for Detection of Dissolved Organic Acids and Alcohols in Potable Water

    NASA Technical Reports Server (NTRS)

    Akse, James R.; Jan, Darrell L. (Technical Monitor)

    2002-01-01

    The Organic Acid and Alcohol Monitor (OAAM) program has resulted in the successful development of a computer controlled prototype analyzer capable of accurately determining aqueous organic acids and primary alcohol concentrations over a large dynamic range with high sensitivity. Formic, acetic, and propionic acid were accurately determined at concentrations as low as 5 to 10 micrograms/L in under 20 minutes, or as high as 10 to 20 mg/L in under 30 minutes. Methanol, ethanol, and propanol were determined at concentrations as low as 20 to 100 micrograms/L, or as high as 10 mg/L in under 30 minutes. Importantly for space based application, the OAAM requires no reagents or hazardous chemicals to perform these analyses needing only power, water, and CO2 free purge gas. The OAAM utilized two membrane processes to segregate organic acids from interfering ions. The organic acid concentration was then determined based upon the conductiometric signal. Separation of individual organic acids was accomplished using a chromatographic column. Alcohols are determined in a similar manner after conversion to organic acids by sequential biocatalytic and catalytic oxidation steps. The OAAM was designed to allow the early diagnosis of under performing or failing sub-systems within the Water Recovery System (WRS) baselined for the International Space Station (ISS). To achieve this goal, several new technologies were developed over the course of the OAAM program.

  18. In vitro ruminal fermentation of organic acids common in forage.

    PubMed Central

    Russell, J B; Van Soest, P J

    1984-01-01

    Mixed rumen bacteria from cows fed either timothy hay or a 60% concentrate were incubated with 7.5 mM citrate, trans-aconitate, malate, malonate, quinate, and shikimate. Citrate, trans-aconitate, and malate were fermented at faster rates than malonate, quinate, and shikimate. Acetate was the primary fermentation product for all six acids. Quinate and shikimate fermentations gave rist to butyrate, whereas malate and malonate produced significant amounts of propionic acid. High-pressure liquid chromatography of fermentation products from trans-aconitate incubations revealed a compound that was subsequently identified as tricarballylate. As much as 40% of the trans-aconitate acid was converted to tricarballylate, and tricarballylate was fermented slowly. The slow rate of tricarballylate metabolism by mixed rumen bacteria and its potential as a magnesium chelator suggest that tricarballylate formation could be an important factor in the hypomagnesemia that leads to grass tetany. PMID:6696413

  19. The use of supported acidic ionic liquids in organic synthesis.

    PubMed

    Skoda-Földes, Rita

    2014-06-26

    Catalysts obtained by the immobilisation of acidic ionic liquids (ILs) on solid supports offer several advantages compared to the use of catalytically active ILs themselves. Immobilisation may result in an increase in the number of accessible active sites of the catalyst and a reduction of the amount of the IL required. The ionic liquid films on the carrier surfaces provide a homogeneous environment for catalytic reactions but the catalyst appears macroscopically as a dry solid, so it can simply be separated from the reaction mixture. As another advantage, it can easily be applied in a continuous fixed bed reactor. In the present review the main synthetic strategies towards the preparation of supported Lewis acidic and Brønsted acidic ILs are summarised. The most important characterisation methods and structural features of the supported ionic liquids are presented. Their efficiency in catalytic reactions is discussed with special emphasis on their recyclability.

  20. Organic acids in precipitation in the Basque country (North of Spain)

    NASA Astrophysics Data System (ADS)

    Durana, N.; Casado, H.; García, C.; Ezcurra, A.; Lacaux, J. P.; Encinas, D.

    This paper discusses the results of the measurement of organic anions in precipitation collected since July 1989 in Olaeta, a rural village in the Basque Country (North of Spain). In order to gain a deeper knowledge of the characteristics and acids responsible for the free acidity observed in precipitation, a study was started within the EPOCA programme (Estudios en el Pirineo Occidental de la Contaminación Acida), for measuring organic anions: formiate, acetate and propionate. These results show that it was possible to observe organic anions in nearly every event, with a 5% contribution to the anionic total, and with an appreciable seasonal variation in concentration. The maximum contribution of organic acids to free acidity (H +) is 6% in rain events with pH≤5.0. There is significant correlation between acetic acid and inorganic ions of marine origin Cl -, Na + and Mg 2+ which might indicate the importance which the air masses of marine origin are going to have in the concentration of this acid. There is also significant correlation between formic acid and SO 42- and H + ions which might indicate the relatively importance contribution of formic acid to free acidity.

  1. Adsorption of small weak organic acids on goethite: Modeling of mechanisms

    SciTech Connect

    Filius, J.D.; Hiemstra, T.; Riemsdijk, W.H. Van

    1997-11-15

    The adsorption of lactate, oxalate, malonate, phthalate, and citrate has been determined experimentally as a function of concentration, pH, and ionic strength. The data have been described with the CD-MUSIC model of Hiemstra and Van Riemsdijk which allows a distribution of charge of the organic molecule over the surface and the Stern layer. Simultaneously, the concentration, pH, and salt dependency as well as the basic charging behavior of goethite could be described well. On the basis of model calculations, a distinction is made between inner and outer sphere complexation of weak organic acids by goethite. The results indicate that the affinity of the organic acids is dominated by the electrostatic attraction. The intrinsic affinity constants for the exchange reaction of surface water groups and organic acids, expressed per bond, increases with increasing number of reactive groups on the organic molecule. Ion pair formation between noncoordinated carboxylic groups of adsorbed organic acids and cations of the background electrolyte proved to be important for the salt dependency. The knowledge obtained may contribute to the interpretation of the binding of larger organic acids like fulvic and humic acids.

  2. Mobilization of soil-borne arsenic by three common organic acids: Dosage and time effects.

    PubMed

    Onireti, Olaronke O; Lin, Chuxia

    2016-03-01

    A batch experiment was conducted to investigate the mobilization of soil-borne arsenic by three common low-molecular-weight organic acids with a focus on dosage and time effects. The results show that oxalic acid behaved differently from citric acid and malic acid in terms of mobilizing As that was bound to iron compounds. At an equivalent molar concentration, reactions between oxalic acid and soil-borne Fe were kinetically more favourable, as compared to those between either citric acid or malic acid and the soil-borne Fe. It was found that reductive dissolution of soil-borne Fe played a more important role in liberating As, as compared to non-reductive reactions. Prior to the 7th day of the experiment, As mobility increased with increasing dose of oxalic acid while there was no significant difference (P > 0.05) in mobilized As among the treatments with different doses of citric acid or malic acid. The dosage effect on soil-borne As mobilization in the citric acid and malic acid treatments became clear only after the 7th day of the experiment. Soluble Ca present in the soils could cause re-immobilization of As by competing with solution-borne Fe for available organic ligands to form practically insoluble organic compounds of calcium (i.e. calcium oxalate). This resulted in transformation of highly soluble organic complexes of iron (i.e. iron oxalate complexes) into slightly soluble organic compounds of iron (i.e. iron oxalate) or free ferric ion, which then reacted with the solution-borne arsenate ions to form practically insoluble iron arsenates in the latter part of the experiment.

  3. Genomic organization of the human lysosomal acid lipase gene (LIPA)

    SciTech Connect

    Aslandis, C.; Klima, H.; Lackner, K.J.; Schmitz, G. )

    1994-03-15

    Defects in the human lysosomal acid lipase gene are responsible for cholesteryl ester storage disease (CESD) and Wolman disease. Exon skipping as the cause for CESD has been demonstrated. The authors present here a summary of the exon structure of the entire human lysosomal acid lipase gene consisting of 10 exons, together with the sizes of genomic EcoRI and SacI fragments hybridizing to each exon. In addition, the DNA sequence of the putative promoter region is presented. The EMBL accession numbers for adjacent intron sequences are given. 7 refs., 2 figs., 1 tab.

  4. An enhanced procedure for measuring organic acids and methyl esters in PM2.5

    NASA Astrophysics Data System (ADS)

    Liu, F.; Duan, F.; He, K.; Ma, Y.; Rahn, K. A.; Zhang, Q.

    2015-03-01

    We have developed an enhanced analytical procedure to measure organic acids and methyl esters in fine aerosol with much greater specificity and sensitivity than previously available. This capability is important because of these species and their low concentrations, even in highly polluted atmospheres like Beijing, China. The procedure first separates the acids and esters from the other organic compounds with anion-exchange solid- phase extraction (SPE), then, quantifies them by gas chromatography coupled with mass spectrometry. This allows us to accurately quantify the C4-C11 dicarboxylic and the C8-C30 monocarboxylic acids. Then the acids are separated from the esters on an aminopropyl SPE cartridge, whose weak retention isolates and enriches the acids from esters prevents the fatty acids and dimethyl phthalate from being overestimated. The resulting correlations between the aliphatic acids and fatty acid methyl esters (FAMEs) suggest that FAMEs had sources similar to those of the carboxylic acids, or were formed by esterifying carboxylic acids, or that aliphatic acids were formed by hydrolyzing FAMEs. In all, 17 aromatic acids were identified and quantified using this procedure coupled with gas chromatography-tandem mass spectrometry, including the five polycyclic aromatic hydrocarbon (PAH) acids 2-naphthoic, biphenyl-4-carboxylic, 9-oxo-9H-fluorene-1-carboxylic, biphenyl-4,4´-dicarboxylic, and phenanthrene-1-carboxylic acid, plus 1,8-naphthalic anhydride. Correlations between the PAH-acids and the dicarboxylic and aromatic acids indicated that the first three acids and 1,8-naphthalic anhydride were mainly secondary, the last two mainly primary.

  5. Determination of stable carbon isotopes of organic acids and carbonaceous aerosols in the atmosphere.

    PubMed

    Fisseha, R; Saurer, M; Jäggi, M; Szidat, S; Siegwolf, R T W; Baltensperger, U

    2006-01-01

    A wet oxidation method for the compound-specific determination of stable carbon isotopes (delta(13)C) of organic acids in the gas and aerosol phase, as well as of water-soluble organic carbon (WSOC), is presented. Sampling of the organic acids was done using a wet effluent diffusion denuder/aerosol collector (WEDD/AC) coupled to an ion chromatography (IC) system. The method allows for compound-specific stable carbon isotope analysis by collecting different fractions of organic acids at the end of the IC system using a fraction collector. delta(13)C analyses of organic acids were conducted by oxidizing the organic acids with sodium persulfate at a temperature of 100 degrees C and determining the delta(13)C value of the resulting carbon dioxide (CO(2)) with an isotope ratio mass spectrometer. In addition, analysis of delta(13)C of the WSOC was performed for particulate carbon collected on aerosol filters. The WSOC was extracted from the filters using ultrapure water (MQ water), and the dissolved organic carbon was oxidized to CO(2) using the oxidation method. The wet oxidation method has an accuracy of 0.5 per thousand with a precision of +/-0.4 per thousand and provides a quantitative result for organic carbon with a detection limit of 150 ng of carbon.

  6. Abnormal Characteristics of Low Molecular Weight Organic Acids in Surface Water of the Jiaozhou Bay

    NASA Astrophysics Data System (ADS)

    Ding, H.; Liu, Z.; Yang, G.; Sun, L.

    2012-12-01

    Organic acids are important components of dissolved organic matter in sea water. Generally, in oxic sea water, the concentrations of low molecular weight organic acids (LMWOAs), such as formate, acetate and lactate are too low to be analyzed by high performance liquid chromatography (HPLC) directly. Our recent study of Jiaozhou Bay, Shandong, China showed that the concentrations of LMWOAs in the surface sea water were high enough to be quantified by HPLC. In the surface sea water of the bay, three typical LMWOAs----formate, acetate and lactate were identified. Concentrations of formate, lactate and acetate ranged from 1.97 to 5.29μmol/L, 5.79 to 12.77μmol/L and 1.97 to 7.23 μmol/L, respectively. The concentrations of all three organic acids varied dramatically in different areas of the bay. Low concentrations usually occurred in the central region and high concentrations usually occurred along coastal area. The contribution of LMWOAs to dissolved organic carbon (DOC) was significantly higher than published data. On average, total organic acid (TOA, considered as total concentration of the three identified organic acids) accounted for more than 20% of dissolved organic carbon (DOC) in the surface water of the Bay. The high concentrations of LMWOAs and their unusual high contribution to DOC were attributed to human activities such as sewage discharge, aquaculture and etc. along the coastal area.

  7. Protected Organic Acid Blends as an Alternative to Antibiotics in Finishing Pigs

    PubMed Central

    Upadhaya, S. D.; Lee, K. Y.; Kim, I. H.

    2014-01-01

    A total of 120 finishing pigs ([Yorkshire×Landrace]×Duroc) with an average body weight (BW) of 49.72 ±1.72 kg were used in 12-wk trial to evaluate the effects of protected organic acids on growth performance, nutrient digestibility, fecal micro flora, meat quality and fecal gas emission. Pigs were randomly allotted to one of three dietary treatments (10 replication pens with 4 pigs per pen) in a randomly complete block design based on their initial BW. Each dietary treatment consisted of: Control (CON/basal diet), OA1 (basal diet+0.1% organic acids) and OA2 (basal diet+0.2% organic acids). Dietary treatment with protected organic acid blends linearly improved (p<0.001) average daily gain during 0 to 6 week, 6 to 12 week as well as overall with the increase in their inclusion level in the diet. The dry matter, N, and energy digestibility was higher (linear effect, p<0.001) with the increase in the dose of protected organic acid blends during 12 week. During week 6, a decrease (linear effect, p = 0.01) in fecal ammonia contents was observed with the increase in the level of protected organic acid blends on d 3 and d 5 of fermentation. Moreover, acetic acid emission decreased linearly (p = 0.02) on d7 of fermentation with the increase in the level of protected organic acid blends. During 12 weeks, linear decrease (p<0.001) in fecal ammonia on d 3 and d 5 and acetic acid content on d 5 of fermentation was observed with the increase in the level of protected organic acid blends. Supplementation of protected organic acid blends linearly increased the longissimus muscle area with the increasing concentration of organic acids. Moreover, color of meat increased (linear effect, quadratic effect, p<0.001, p<0.002 respectively) and firmness of meat showed quadratic effect (p = 0.003) with the inclusion of increasing level of protected organic acid in the diet. During the 6 week, increment in the level of protected organic acid blends decreased (linear effect, p = 0

  8. Sensitive Amino Acid Composition and Chirality Analysis with the Mars Organic Analyzer (MOA)

    NASA Technical Reports Server (NTRS)

    Skelley, Alison M.; Scherer, James R.; Aubrey, Andrew D.; Grover, William H.; Ivester, Robin H. C.; Ehrenfreund, Pascale; Grunthaner, Frank J.; Bada, Jeffrey L.; Mathies, Richard A.

    2005-01-01

    Detection of life on Mars requires definition of a suitable biomarker and development of sensitive yet compact instrumentation capable of performing in situ analyses. Our studies are focused on amino acid analysis because amino acids are more resistant to decomposition than other biomolecules, and because amino acid chirality is a well-defined biomarker. Amino acid composition and chirality analysis has been previously demonstrated in the lab using microfabricated capillary electrophoresis (CE) chips. To analyze amino acids in the field, we have developed the Mars Organic Analyzer (MOA), a portable analysis system that consists of a compact instrument and a novel multi-layer CE microchip.

  9. Students' Understanding of Acids/Bases in Organic Chemistry Contexts

    ERIC Educational Resources Information Center

    Cartrette, David P.; Mayo, Provi M.

    2011-01-01

    Understanding key foundational principles is vital to learning chemistry across different contexts. One such foundational principle is the acid/base behavior of molecules. In the general chemistry sequence, the Bronsted-Lowry theory is stressed, because it lends itself well to studying equilibrium and kinetics. However, the Lewis theory of…

  10. [Rapid determination of eight organic acids in plant tissue by sequential extraction and high performance liquid chromatography].

    PubMed

    Huang, Tianzhi; Wang, Shijie; Liu Xiuming; Liu, Hong; Wu, Yanyou; Luo Xuqiang

    2014-12-01

    A sequential extraction method was developed to determine different forms of oxalate and seven oxalate-metabolism-related organic acids (glyoxylic acid, tartaric acid, glycolic acid, malic acid, acetic acid, citric acid, succinic acid) in plant tissue. The ultra-pure water was used as the extraction medium to obtain water-soluble oxalic acid and the other seven water-soluble organic acids. After the extraction of the water-soluble organic acids, the residues were extracted by dilute hydrochloric acid successively to get the acid-soluble oxalate which entered the liquid phase. A Hypersil ODS column was used with 5 mmol/L potassium dihydrogen phosphate buffer solution (pH 2. 8) as the mobile phase. The diode array detector was set at 210 nm and the column temperature at 30 °C with the injection volume of 5 µL. The flow rate was controlled at different times which allowed a good and rapid separation of the organic acids and hydrochloric acid. Under these conditions, the linear ranges of the method were 1-2000 mg/L for oxalic acid, 25-2,000 mg/L for acetic acid, and 10-2,000 mg/L for glyoxylic acid, tartaric acid, glycolic acid, malic acid, citric acid and succinic acid, with the correlation coefficients of the eight organic acids ≥ 0. 9996. The average recoveries of the eight organic acids in leaves and roots were 93. 5%-104. 4% and 85. 3%-105. 4% with RSDs of 0. 15% -2.43% and 0. 31%-2. 9% (n=7), respectively. The limits of detection ranged from 1 to 10 ng (S/N=3). The results indicated that the method is accurate, rapid and reproducible for the determination of organic acids in plant samples.

  11. Water-soluble organic carbon, dicarboxylic acids, ketoacids, and α-dicarbonyls in the tropical Indian aerosols

    NASA Astrophysics Data System (ADS)

    Pavuluri, Chandra Mouli; Kawamura, Kimitaka; Swaminathan, T.

    2010-06-01

    Tropical aerosol (PM10) samples (n = 49) collected from southeast coast of India were studied for water-soluble dicarboxylic acids (C2-C12), ketocarboxylic acids (C2-C9), and α-dicarbonyls (glyoxal and methylglyoxal), together with analyses of total carbon (TC) and water-soluble organic carbon (WSOC). Their distributions were characterized by a predominance of oxalic acid followed by terephthalic (t-Ph), malonic, and succinic acids. Total concentrations of diacids (227-1030 ng m-3), ketoacids (16-105 ng m-3), and dicarbonyls (4-23 ng m-3) are comparative to those from other Asian megacities such as Tokyo and Hong Kong. t-Ph acid was found as the second most abundant diacid in the Chennai aerosols. This feature has not been reported previously in atmospheric aerosols. t-Ph acid is most likely derived from the field burning of plastics. Water-soluble diacids were found to contribute 0.4%-3% of TC and 4%-11% of WSOC. Based on molecular distributions and backward air mass trajectories, we found that diacids and related compounds in coastal South Indian aerosols are influenced by South Asian and Indian Ocean monsoons. Organic aerosols are also suggested to be significantly transported long distances from North India and the Middle East in early winter and from Southeast Asia in late winter, but some originate from photochemical reactions over the Bay of Bengal. In contrast, the Arabian Sea, Indian Ocean, and South Indian continent are suggested as major source regions in summer. We also found daytime maxima of most diacids, except for C9 and t-Ph acids, which showed nighttime maxima in summer. Emissions from marine and terrestrial plants, combined with land/sea breezes and in situ photochemical oxidation, are suggested especially in summer as an important factor that controls the composition of water-soluble organic aerosols over the southeast coast of India. Regional emissions from anthropogenic sources are also important in megacity Chennai, but their influence is

  12. Differing Organic Acid Exudation Pattern Explains Calcifuge and Acidifuge Behaviour of Plants

    PubMed Central

    Tyler, Germund; Ström, Lena

    1995-01-01

    Many vascular plant species are unable to colonize calcareous sites. Thus, the floristic composition of adjacent limestone and acid silicate soils differs greatly. The inability of calcifuge plants to establish in limestone sites seems related to a low capacity of such plants to solubilize and absorb Fe or phosphate from these soils. Until now, mechanisms regulating this differing ability of plants to colonize limestone sites have not been elucidated. We propose that contrasting exudation of low-molecular organic acids is a major mechanism involved and show that germinating seeds and young seedlings of limestone plants exude considerably more di- and tricarboxylic acids than calcifuges, which mainly exude monocarboxylic acids. The tricarboxylic citric acid is a powerful extractor of Fe, and the dicarboxylic oxalic acid a very effective extractor of phosphate from limestone soils. Monocarboxylic acids are very weak in these respects. The study is based on ten species from limestone soils and ten species from acid silicate soils. PMID:21247915

  13. Effectiveness of hand sanitizers with and without organic acids for removal of rhinovirus from hands.

    PubMed

    Turner, Ronald B; Fuls, Janice L; Rodgers, Nancy D

    2010-03-01

    These studies evaluated the effectiveness of ethanol hand sanitizers with or without organic acids to remove detectable rhinovirus from the hands and prevent experimental rhinovirus infection. Ethanol hand sanitizers were significantly more effective than hand washing with soap and water. The addition of organic acids to the ethanol provided residual virucidal activity that persisted for at least 4 h. Whether these treatments will reduce rhinovirus infection in the natural setting remains to be determined.

  14. Production of starch with antioxidative activity by baking starch with organic acids.

    PubMed

    Miwa, Shoji; Nakamura, Megumi; Okuno, Michiko; Miyazaki, Hisako; Watanabe, Jun; Ishikawa-Takano, Yuko; Miura, Makoto; Takase, Nao; Hayakawa, Sachio; Kobayashi, Shoichi

    2011-01-01

    A starch ingredient with antioxidative activity, as measured by the DPPH method, was produced by baking corn starch with an organic acid; it has been named ANOX sugar (antioxidative sugar). The baking temperature and time were fixed at 170 °C and 60 min, and the organic acid used was selected from preliminary trials of various kinds of acid. The phytic acid ANOX sugar preparation showed the highest antioxidative activity, but the color of the preparation was almost black; we therefore selected L-tartaric acid which had the second highest antioxidative activity. The antioxidative activity of the L-tartaric acid ANOX sugar preparation was stable against temperature, light, and enzyme treatments (α-amylase and glucoamylase). However, the activity was not stable against variations in water content and pH value. The antioxidative activity of ANOX sugar was stabilized by treating with boiled water or nitrogen gas, or by pH adjustment.

  15. Perturbations of amino acid metabolism associated with glyphosate-dependent inhibition of shikimic acid metabolism affect cellular redox homeostasis and alter the abundance of proteins involved in photosynthesis and photorespiration.

    PubMed

    Vivancos, Pedro Diaz; Driscoll, Simon P; Bulman, Christopher A; Ying, Liu; Emami, Kaveh; Treumann, Achim; Mauve, Caroline; Noctor, Graham; Foyer, Christine H

    2011-09-01

    The herbicide glyphosate inhibits the shikimate pathway of the synthesis of amino acids such as phenylalanine, tyrosine, and tryptophan. However, much uncertainty remains concerning precisely how glyphosate kills plants or affects cellular redox homeostasis and related processes in glyphosate-sensitive and glyphosate-resistant crop plants. To address this issue, we performed an integrated study of photosynthesis, leaf proteomes, amino acid profiles, and redox profiles in the glyphosate-sensitive soybean (Glycine max) genotype PAN809 and glyphosate-resistant Roundup Ready Soybean (RRS). RRS leaves accumulated much more glyphosate than the sensitive line but showed relatively few changes in amino acid metabolism. Photosynthesis was unaffected by glyphosate in RRS leaves, but decreased abundance of photosynthesis/photorespiratory pathway proteins was observed together with oxidation of major redox pools. While treatment of a sensitive genotype with glyphosate rapidly inhibited photosynthesis and triggered the appearance of a nitrogen-rich amino acid profile, there was no evidence of oxidation of the redox pools. There was, however, an increase in starvation-associated and defense proteins. We conclude that glyphosate-dependent inhibition of soybean leaf metabolism leads to the induction of defense proteins without sustained oxidation. Conversely, the accumulation of high levels of glyphosate in RRS enhances cellular oxidation, possibly through mechanisms involving stimulation of the photorespiratory pathway.

  16. Perturbations of Amino Acid Metabolism Associated with Glyphosate-Dependent Inhibition of Shikimic Acid Metabolism Affect Cellular Redox Homeostasis and Alter the Abundance of Proteins Involved in Photosynthesis and Photorespiration1[W][OA

    PubMed Central

    Vivancos, Pedro Diaz; Driscoll, Simon P.; Bulman, Christopher A.; Ying, Liu; Emami, Kaveh; Treumann, Achim; Mauve, Caroline; Noctor, Graham; Foyer, Christine H.

    2011-01-01

    The herbicide glyphosate inhibits the shikimate pathway of the synthesis of amino acids such as phenylalanine, tyrosine, and tryptophan. However, much uncertainty remains concerning precisely how glyphosate kills plants or affects cellular redox homeostasis and related processes in glyphosate-sensitive and glyphosate-resistant crop plants. To address this issue, we performed an integrated study of photosynthesis, leaf proteomes, amino acid profiles, and redox profiles in the glyphosate-sensitive soybean (Glycine max) genotype PAN809 and glyphosate-resistant Roundup Ready Soybean (RRS). RRS leaves accumulated much more glyphosate than the sensitive line but showed relatively few changes in amino acid metabolism. Photosynthesis was unaffected by glyphosate in RRS leaves, but decreased abundance of photosynthesis/photorespiratory pathway proteins was observed together with oxidation of major redox pools. While treatment of a sensitive genotype with glyphosate rapidly inhibited photosynthesis and triggered the appearance of a nitrogen-rich amino acid profile, there was no evidence of oxidation of the redox pools. There was, however, an increase in starvation-associated and defense proteins. We conclude that glyphosate-dependent inhibition of soybean leaf metabolism leads to the induction of defense proteins without sustained oxidation. Conversely, the accumulation of high levels of glyphosate in RRS enhances cellular oxidation, possibly through mechanisms involving stimulation of the photorespiratory pathway. PMID:21757634

  17. Modulation of Acetone-Butanol-Ethanol Fermentation by Carbon Monoxide and Organic Acids

    PubMed Central

    Datta, Rathin; Zeikus, J. G.

    1985-01-01

    Metabolic modulation of acetone-butanol-ethanol fermentation by Clostridium acetobutylicum with carbon monoxide (CO) and organic acids is described. CO, which is a known inhibitor of hydrogenase, was found to be effective in the concentration range of dissolved CO corresponding to a CO partial pressure of 0.1 to 0.2 atm. Metabolic modulation by CO was particularly effective when organic acids such as acetic and butyric acids were added to the fermentation as electron sinks. The uptake of organic acids was enhanced, and increases in butyric acid uptake by 50 to 200% over control were observed. Hydrogen production could be reduced by 50% and the ratio of solvents could be controlled by CO modulation and organic acid addition. Acetone production could be eliminated if desired. Butanol yield could be increased by 10 to 15%. Total solvent yield could be increased 1 to 3% and the electron efficiency to acetone-butanol-ethanol solvents could be increased from 73 to 78% for controls to 80 to 85% for CO- and organic acid-modulated fermentations. Based on these results, the dynamic nature of electron flow in this fermentation has been elucidated and mechanisms for metabolic control have been hypothesized. PMID:16346746

  18. Microbial production of organic acids in aquitard sediments and its role in aquifer geochemistry

    USGS Publications Warehouse

    McMahon, P.B.; Chapelle, F.H.

    1991-01-01

    MICROBIAL activity in aquifers plays an important part in the chemical evolution of ground water1-5. The most important terminal electron-accepting microbial processes in deeply buried anaerobic aquifers are iron reduction, sulphate reduction and methanogenesis5-8, each of which requires simple organic compounds or hydrogen (H2) as electron donors. Until now, the source of these compounds was unknown because the concentrations of dissolved organic carbon and sedimentary organic carbon in aquifers are extremely low9-11. Here we show that rates of microbial fermentation exceed rates of respiration in organic-rich aquitards (low-permeability sediments stratigraphically adjacent to higher-permeability aquifer sediments), resulting in a net accumulation of simple organic acids in pore waters. In aquifers, however, respiration outpaces fermentation, resulting in a net consumption of organic acids. The concentration gradient that develops in response to these two processes drives a net diffusive flux of organic acids from aquitards to aquifers. Diffusion calculations demonstrate that rates of organic acid transport are sufficient to account for observed rates of microbial respiration in aquifers. This overall process effectively links the large pool of sedimentary organic carbon in aquitards to microbial respiration in aquifers, and is a principal mechanism driving groundwater chemistry changes in aquifers.

  19. Development of a microgravity-compatible reagentless organic acid and alcohol monitor (OAAM).

    PubMed

    Akse, J R; Atwater, J E; Holtsnider, J T

    2001-01-01

    The development of a microgravity-compatible analyzer capable of quantifying organic acids in water is described. The analyzer employs "reagentless" solid phase acidification to convert organic acids to the volatile form followed by membrane separation and specific conductance detection to determine organic acids at concentrations between 0.005 and 40 mg/L. In the future, this technology will be extended to the detection of alcohols, which will be oxidized to form the corresponding organic acid and then determined using the same processes. An immobilized enzyme biocatalyst, alcohol oxidase, oxidizes alcohols to form an aldehyde. Oxidation to the corresponding organic acid is then completed over a heterogeneous catalyst. The combined organic acid and alcohol monitor (OAAM) will be utilized to determine levels of both analyte classes at various points within the water recovery system (WRS) baselined for the International Space Station (ISS). These data will improve water quality through enhanced process control, while allowing early diagnosis of potential problems. Grant numbers: NAG9-1081.

  20. Effect of temperature on diauxic growth with glucose and organic acids in Pseudomonas fluorescens.

    PubMed

    Lynch, W H; Franklin, M

    1978-08-01

    Growth of Pseudomonas fluorescens in batch culture with glucose and organic acids resulted in typical diauxic responses at 30 degrees C but no detectable diauxic lag at 5 degrees C. At 30 degrees C, organic acids were preferentially utilized during the first growth phase. Glucose utilization was delayed until onset of the second growth phase. Systems involved in direct uptake and catabolism of glucose responded in a manner compatible with repression by malate and/or its metabolites and induction by glucose and/or its metabolites. The oxidative non-phosphorylated pathway, through gluconate and 2-ketogluconate (2-KG) as intermediates, was not induced during either growth phase. At 5 degrees C, growth with glucose and organic acids was biphasic but without diauxic lag. Organic acids were preferentially utilized during the first growth phase. Although carbon from glucose was not fully catabolized until onset of the second growth phase, glucose was oxidized to and accumulated extracellularly as gluconate and 2-KG during the first growth phase. No significant repression of glucose-catabolizing enzymes was observed during growth with organic acids in the presence of glucose. However, uptake activities for gluconate and 2-KG did not increase significantly until onset of the second growth phase. Thus, at low temperatures, psychotrophic P. fluorescens oxidized glucose to extracellular 2-KG, while growing on preferred carbon sources. The 2-KG was then catabolized after depletion of the organic acid.

  1. Resource recovery from waste LCD panel by hydrothermal transformation of polarizer into organic acids.

    PubMed

    Li, Feng; Bai, Lan; He, Wenzhi; Li, Guangming; Huang, Juwen

    2015-12-15

    Based on the significant advantages of hydrothermal technology, it was applied to treat polarizer from the waste LCD panel with the aim of transforming it into organic acids (mainly acetic acid and lactic acid). Investigation was done to evaluate the effects of different factors on yields of organic acids, including the reaction temperature, reaction time and H2O2 supply, and the degradation process of polarizer was analyzed. Liquid samples were analyzed by GC/MS and HPLC, and solid-phase products were characterized by SEM and FTIR. Results showed that at the condition of temperature 300 °C and reaction time 5 min, the organic materials reached its highest conversion rate of 71.47% by adding 0.2 mL H2O2 and acetic acid was dominant in the products of organic acids with the yield of 6.78%. When not adding H2O2 to the system, the yields of lactic and acetic acid were respectively 4.24% and 3.80% at a nearly equal degree, they are suitable for esterification to form ethyl lactate instead of separating them for this case. In the hydrothermal process, polarizer was first decomposed to monosaccharides, alkane, etc., and then furfural and acids are produced with further decomposition.

  2. Usnic Acid and the Intramolecular Hydrogen Bond: A Computational Experiment for the Organic Laboratory

    ERIC Educational Resources Information Center

    Green, Thomas K.; Lane, Charles A.

    2006-01-01

    A computational experiment is described for the organic chemistry laboratory that allows students to estimate the relative strengths of the intramolecular hydrogen bonds of usnic and isousnic acids, two related lichen secondary metabolites. Students first extract and purify usnic acid from common lichens and obtain [superscript 1]H NMR and IR…

  3. Isolation of hydrophilic organic acids from water using nonionic macroporous resins

    USGS Publications Warehouse

    Aiken, G.R.; McKnight, Diane M.; Thorn, K.A.; Thurman, E.M.

    1992-01-01

    A method has been developed for the isolation of hydrophilic organic acids from aquatic environments using Amberlite* * Use of trade names in this report is for identification purposes only and does not constitute endorsement by the U.S. Geological Survey. XAD-4 resin. The method uses a two column array of XAD-8 and XAD-4 resins in series. The hydrophobic organic acids, composed primarily of aquatic fulvic acid, are removed from the sample on XAD-8, followed by the isolation of the more hydrophilic organic acids on XAD-4. For samples from a number of diverse environments, more of the dissolved organic carbon was isolated on the XAD-8 resin (23-58%) than on the XAD-4 resin (7-25%). For these samples, the hydrophilic acids have lower carbon and hydrogen contents, higher oxygen and nitrogen contents, and are lower in molecular weight than the corresponding fulvic acids. 13C NMR analyses indicate that the hydrophilic acids have a lower concentration of aromatic carbon and greater heteroaliphatic, ketone and carboxyl content than the fulvic acid. ?? 1992.

  4. Phenolic compounds and fatty acid composition of organic and conventional grown pecan kernels

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this study, differences in contents of phenolic compounds and fatty acids in pecan kernels of organically versus conventionally grown pecan cultivars (‘Desirable’, ‘Cheyenne’, and ‘Wichita’) were evaluated. Although we were able to identify nine phenolic compounds (gallic acid, catechol, catechin...

  5. Recovery of nickel and cobalt from organic acid complexes: adsorption mechanisms of metal-organic complexes onto aminophosphonate chelating resin.

    PubMed

    Deepatana, A; Valix, M

    2006-09-21

    This study examined the recovery of nickel and cobalt from organic acid complexes using a chelating aminophosphonate Purolite S950 resin. These metal complexes are generated by bioleaching nickel laterite ores, a commercial nickel and cobalt mineral oxide, with heterotrophic organism and their metabolites or organic acid products. Equilibrium adsorption tests were conducted as a function of Ni and Co concentrations (15-2000 mg/L), solution pH (0.01 and 0.1 M acids) and three metabolic complexing agents (citrate, malate and lactate). It was shown that the adsorption of the various Ni- and Co-complexes on Purolite were quite low, 16-18 and 5.4-9 mg/g of resin, respectively, in comparison to the smaller nickel ions and nickel sulfate. This was attributed to the bulky organic ligands which promoted crowding effect or steric hindrance. The adsorption of these complexes was further hampered by the strong affinity of the resin to H+ ions under acidic conditions. Mechanisms of adsorption, as inferred from the fitted empirical Langmuir and Freundlich models, were correlated to the proposed steric hindrance and competitive adsorption effects. Nickel and cobalt elution from the resin were found be effective and were independent of the type of metal complexes and metal concentrations. This study demonstrated the relative challenges involved in recovering nickel and cobalt from bioleaching solutions.

  6. Oxidative degradation of organic acids conjugated with sulfite oxidation in flue gas desulfurization

    SciTech Connect

    Lee, Y.I.

    1986-01-01

    Organic acid degradation conjugated with sulfite oxidation has been studied under flue gas desulfurization (EGD) conditions. The oxidative degradation constant, k/sub 12/, is defined as the ratio of organic acid degradation rate and sulfite oxidation rate after being normalized by the concentrations of organic acid and dissolved S(IV). K/sub 12/, not significantly affected by pH or dissolved oxygen, is around 10/sup -3/ in the absence of manganese or iron. However, k/sub 12/ is increased by certain transition metals such as Co, Ni, and Fe and is decreased by Mn and halides. Lower dissolved S(IV) magnified these effects. No k/sub 12/ greater than 4 x 10/sup -3/ or smaller than 0.1 x 10/sup -3/ has been observed. A free radical mechanism was proposed to describe the kinetics: (1) sulfate free radical is the major radical responsible to the degradation of organic acid; (2) ferrous generates sulfate radical by reacting with monoxypersulfate to enhance k/sub 12/; (3) manganous consumes sulfate radical to decrease k/sub 12/; (4) dissolved S(IV) competes with ferrous for monoxypersulfate and with manganous for sulfate radical to demonstrate the effects of dissolved S(IV) on k/sub 12/. Hydroxy and sulfonated carboxylic acids degrade approximately three times slower than saturated dicarboxylic acids; while maleic acid, an unsaturated dicarboxylic acid, degraded an order of magnitude faster. A wide spectrum of degradation products of adipic acid were found, including carbon dioxide - the major product, glutaric semialdehyde - the major retained product with low manganese, glutaric acid and valeric acids - the major retained product with high manganese, lower molecular weight mono- and dicarboxylic acids, other carbonyl compounds, and hydrocarbons.

  7. Organic acids and selected nitrogen species for ABLE-3

    NASA Technical Reports Server (NTRS)

    Talbot, Robert W.

    1991-01-01

    The NASA Global Tropospheric Experiment (GTE) executed airborne science missions aboard the NASA Wallops Electra (NA429) in the North American high latitude (greater than 45 deg North) atmosphere during Jul. to Aug. 1988 and Jul. to Aug. 1990. These missions were part of GTE's Atmospheric Boundary Layer Experiment (ABLE). The 1988 mission , ABLE-3A, examined the ecosystems of Alaska as a source and/or sink for important tropospheric gases and particles, and gained new information on the chemical composition of the Arctic atmosphere during the summertime. During 1990 the second high latitude mission, ABLE-3B, focused on the Hudson Bay Lowland and Labrador regions of Canada. Both of these missions provided benchmark data sets on atmosphere biosphere exchange and atmospheric chemistry over largely uninhabited regions of North America. In support of the GTE/ABLE-3A and -3B field missions, the University of New Hampshire flew instrumentation aboard the Wallops Electra research aircraft to provide measurements of the trace gases nitric (HNO3), formic (HCOOH), and acetic (CH3COOH) acid. In addition, measurements were conducted to determine the major water soluble ionic composition of the atmospheric aerosol. For ABLE-3B, groundbased measurements of the acidic trace gases were also performed from the NASA micrometerological tower situated at Schefferville, Laborador. These measurements were aimed at assessing dry deposition of acidic gases to the taiga ecosystem in the Laborador region of Canada.

  8. Interaction between common organic acids and trace nucleation species in the Earth's atmosphere.

    PubMed

    Xu, Yisheng; Nadykto, Alexey B; Yu, Fangqun; Herb, J; Wang, Wei

    2010-01-14

    Atmospheric aerosols formed via nucleation in the Earth's atmosphere play an important role in the aerosol radiative forcing associated directly with global climate changes and public health. Although it is well-known that atmospheric aerosol particles contain organic species, the chemical nature of and physicochemical processes behind atmospheric nucleation involving organic species remain unclear. In the present work, the interaction of common organic acids with molecular weights of 122, 116, 134, 88, 136, and 150 (benzoic, maleic, malic, pyruvic, phenylacetic, and tartaric acids) with nucleation precursors and charged trace species has been investigated. We found a moderate strong effect of the organic species on the stability of neutral and charged ionic species. In most cases, the free energies of the mixed H(2)SO(4)-organic acid dimer formation are within 1-1.5 kcal mol(-1) of the (H(2)SO(4))(NH(3)) formation energy. The interaction of the organic acids with trace ionic species is quite strong, and the corresponding free energies far exceed those of the (H(3)O(+))(H(2)SO(4)) and (H(3)O(+))(H(2)SO(4))(2) formation. These considerations lead us to conclude that the aforementioned organic acids may possess a substantial capability of stabilizing both neutral and positively charged prenucleation clusters, and thus, they should be studied further with regard to their involvement in the gas-to-particle conversion in the Earth's atmosphere.

  9. Detection and structural identification of dissolved organic matter in Antarctic glacial ice at natural abundance by SPR-W5-WATERGATE 1H NMR spectroscopy.

    PubMed

    Pautler, Brent G; Simpson, André J; Simpson, Myrna J; Tseng, Li-Hong; Spraul, Manfred; Dubnick, Ashley; Sharp, Martin J; Fitzsimons, Sean J

    2011-06-01

    Dissolved organic matter (DOM) is ubiquitous in aquatic ecosystems and is derived from various inputs that control its turnover. Glaciers and ice sheets are the second largest water reservoir in the global hydrologic cycle, but little is known about glacial DOM composition or contributions to biogeochemical cycling. Here we employ SPR-W5-WATERGATE (1)H NMR spectroscopy to elucidate and quantify the chemical structures of DOM constituents in Antarctic glacial ice as they exist in their natural state (average DOC of 8 mg/L) without isolation or preconcentration. This Antarctic glacial DOM is predominantly composed of a mixture of small recognizable molecules differing from DOM in marine, lacustrine, and other terrestrial environments. The major constituents detected in three distinct types of glacial ice include lactic and formic acid, free amino acids, and a mixture of simple sugars and amino sugars with concentrations that vary between ice types. The detection of free amino acid and amino sugar monomer components of peptidoglycan within the ice suggests that Antarctic glacial DOM likely originates from in situ microbial activity. As these constituents are normally considered to be biologically labile (fast cycling) in nonglacial environments, accelerated glacier melt and runoff may result in a flux of nutrients into adjacent ecosystems.

  10. Molecular understanding of atmospheric particle formation from sulfuric acid and large oxidized organic molecules

    PubMed Central

    Schobesberger, Siegfried; Junninen, Heikki; Bianchi, Federico; Lönn, Gustaf; Ehn, Mikael; Lehtipalo, Katrianne; Dommen, Josef; Ehrhart, Sebastian; Ortega, Ismael K.; Franchin, Alessandro; Nieminen, Tuomo; Riccobono, Francesco; Hutterli, Manuel; Duplissy, Jonathan; Almeida, João; Amorim, Antonio; Breitenlechner, Martin; Downard, Andrew J.; Dunne, Eimear M.; Flagan, Richard C.; Kajos, Maija; Keskinen, Helmi; Kirkby, Jasper; Kupc, Agnieszka; Kürten, Andreas; Kurtén, Theo; Laaksonen, Ari; Mathot, Serge; Onnela, Antti; Praplan, Arnaud P.; Rondo, Linda; Santos, Filipe D.; Schallhart, Simon; Schnitzhofer, Ralf; Sipilä, Mikko; Tomé, António; Tsagkogeorgas, Georgios; Vehkamäki, Hanna; Wimmer, Daniela; Baltensperger, Urs; Carslaw, Kenneth S.; Curtius, Joachim; Hansel, Armin; Petäjä, Tuukka; Kulmala, Markku; Donahue, Neil M.; Worsnop, Douglas R.

    2013-01-01

    Atmospheric aerosols formed by nucleation of vapors affect radiative forcing and therefore climate. However, the underlying mechanisms of nucleation remain unclear, particularly the involvement of organic compounds. Here, we present high-resolution mass spectra of ion clusters observed during new particle formation experiments performed at the Cosmics Leaving Outdoor Droplets chamber at the European Organization for Nuclear Research. The experiments involved sulfuric acid vapor and different stabilizing species, including ammonia and dimethylamine, as well as oxidation products of pinanediol, a surrogate for organic vapors formed from monoterpenes. A striking resemblance is revealed between the mass spectra from the chamber experiments with oxidized organics and ambient data obtained during new particle formation events at the Hyytiälä boreal forest research station. We observe that large oxidized organic compounds, arising from the oxidation of monoterpenes, cluster directly with single sulfuric acid molecules and then form growing clusters of one to three sulfuric acid molecules plus one to four oxidized organics. Most of these organic compounds retain 10 carbon atoms, and some of them are remarkably highly oxidized (oxygen-to-carbon ratios up to 1.2). The average degree of oxygenation of the organic compounds decreases while the clusters are growing. Our measurements therefore connect oxidized organics directly, and in detail, with the very first steps of new particle formation and their growth between 1 and 2 nm in a controlled environment. Thus, they confirm that oxidized organics are involved in both the formation and growth of particles under ambient conditions. PMID:24101502

  11. Molecular understanding of atmospheric particle formation from sulfuric acid and large oxidized organic molecules.

    PubMed

    Schobesberger, Siegfried; Junninen, Heikki; Bianchi, Federico; Lönn, Gustaf; Ehn, Mikael; Lehtipalo, Katrianne; Dommen, Josef; Ehrhart, Sebastian; Ortega, Ismael K; Franchin, Alessandro; Nieminen, Tuomo; Riccobono, Francesco; Hutterli, Manuel; Duplissy, Jonathan; Almeida, João; Amorim, Antonio; Breitenlechner, Martin; Downard, Andrew J; Dunne, Eimear M; Flagan, Richard C; Kajos, Maija; Keskinen, Helmi; Kirkby, Jasper; Kupc, Agnieszka; Kürten, Andreas; Kurtén, Theo; Laaksonen, Ari; Mathot, Serge; Onnela, Antti; Praplan, Arnaud P; Rondo, Linda; Santos, Filipe D; Schallhart, Simon; Schnitzhofer, Ralf; Sipilä, Mikko; Tomé, António; Tsagkogeorgas, Georgios; Vehkamäki, Hanna; Wimmer, Daniela; Baltensperger, Urs; Carslaw, Kenneth S; Curtius, Joachim; Hansel, Armin; Petäjä, Tuukka; Kulmala, Markku; Donahue, Neil M; Worsnop, Douglas R

    2013-10-22

    Atmospheric aerosols formed by nucleation of vapors affect radiative forcing and therefore climate. However, the underlying mechanisms of nucleation remain unclear, particularly the involvement of organic compounds. Here, we present high-resolution mass spectra of ion clusters observed during new particle formation experiments performed at the Cosmics Leaving Outdoor Droplets chamber at the European Organization for Nuclear Research. The experiments involved sulfuric acid vapor and different stabilizing species, including ammonia and dimethylamine, as well as oxidation products of pinanediol, a surrogate for organic vapors formed from monoterpenes. A striking resemblance is revealed between the mass spectra from the chamber experiments with oxidized organics and ambient data obtained during new particle formation events at the Hyytiälä boreal forest research station. We observe that large oxidized organic compounds, arising from the oxidation of monoterpenes, cluster directly with single sulfuric acid molecules and then form growing clusters of one to three sulfuric acid molecules plus one to four oxidized organics. Most of these organic compounds retain 10 carbon atoms, and some of them are remarkably highly oxidized (oxygen-to-carbon ratios up to 1.2). The average degree of oxygenation of the organic compounds decreases while the clusters are growing. Our measurements therefore connect oxidized organics directly, and in detail, with the very first steps of new particle formation and their growth between 1 and 2 nm in a controlled environment. Thus, they confirm that oxidized organics are involved in both the formation and growth of particles under ambient conditions.

  12. Carborane acids. New "strong yet gentle" acids for organic and inorganic chemistry.

    PubMed

    Reed, Christopher A

    2005-04-07

    Icosahedral carborane anions such as CHB11Cl11- are amongst the least coordinating, most chemically inert anions known. They are also amongst the least basic, so their conjugate acids, H(carborane), are superacids (i.e. stronger than 100% H2SO4). Acidity scale measurements indicate that H(CHB11Cl11) is the strongest pure Brønsted acid presently known, surpassing triflic and fluorosulfuric acid. Nevertheless, it is also an extremely gentle acid--because its conjugate base engages in so little chemistry. Carborane acids separate protic acidity from anion nucleophilicity and destructive oxidative capacity in the conjugate base, to a degree not previously achieved. As a result, many long-sought, highly acidic, reactive cations such as protonated benzene (C6H7+), protonated C60(HC60+), tertiary carbocations (R3C+), vinyl cations (R2C=C(+)-R), silylium ions (R3Si+) and discrete hydronium ions (H3O+, H5O2+ etc.) can be readily isolated as carborane salts and characterized at room temperature by X-ray crystallography.

  13. Control of Listeria monocytogenes in Turkey Deli Loaves using Organic Acids as Formulation Ingredients

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The growth of Listeria monocytogenes (LM) in further processed meat products has become a major concern and an important food safety issue. The meat and poultry industries have incorporated interventions such as organic acids in marinades in order to inhibit the growth of LM. In this study, organic...

  14. Acid-Base Learning Outcomes for Students in an Introductory Organic Chemistry Course

    ERIC Educational Resources Information Center

    Stoyanovich, Carlee; Gandhi, Aneri; Flynn, Alison B.

    2015-01-01

    An outcome-based approach to teaching and learning focuses on what the student demonstrably knows and can do after instruction, rather than on what the instructor teaches. This outcome-focused approach can then guide the alignment of teaching strategies, learning activities, and assessment. In organic chemistry, mastery of organic acid-base…

  15. FcLDP1, a Gene Encoding a Late Embryogenesis Abundant (LEA) Domain Protein, Responds to Brassinosteroids and Abscisic Acid during the Development of Fruits in Fragaria chiloensis

    PubMed Central

    Espinoza, Analía; Contreras, Rodrigo; Zúñiga, Gustavo E.; Herrera, Raúl; Moya-León, María Alejandra; Norambuena, Lorena; Handford, Michael

    2016-01-01

    White Chilean strawberries (Fragaria chiloensis) are non-climacteric fruits, with an exotic color and aroma. In order to discover genes involved in the development of these fruits, we identified a fragment of a gene encoding a late embryogenesis abundant domain protein, FcLDP1, that was expressed in early stages of fruit development, particularly in receptacles. Hormones play key roles in regulating the development of non-climacteric fruits. We show that the brassinosteroid content of the white strawberry varies during development. Additionally, FcLDP1 as well as the closest ortholog in the woodland strawberry, F. vesca (FvLDP1) possess multiple brassinosteroid, as well as abscisic acid (ABA) response motifs in the promoter region, consistent with the response of transiently expressed FcLDP1 promoter-GFP fusions to these hormones, and the rise in FcLDP1 transcript levels in white strawberry fruits treated with brassinosteroids or ABA. These findings suggest that both hormones regulate FcLDP1 expression during the development of white strawberries. PMID:27379111

  16. Uses of phage display in agriculture: sequence analysis and comparative modeling of late embryogenesis abundant client proteins suggest protein-nucleic acid binding functionality.

    PubMed

    Kushwaha, Rekha; Downie, A Bruce; Payne, Christina M

    2013-01-01

    A group of intrinsically disordered, hydrophilic proteins-Late Embryogenesis Abundant (LEA) proteins-has been linked to survival in plants and animals in periods of stress, putatively through safeguarding enzymatic function and prevention of aggregation in times of dehydration/heat. Yet despite decades of effort, the molecular-level mechanisms defining this protective function remain unknown. A recent effort to understand LEA functionality began with the unique application of phage display, wherein phage display and biopanning over recombinant Seed Maturation Protein homologs from Arabidopsis thaliana and Glycine max were used to retrieve client proteins at two different temperatures, with one intended to represent heat stress. From this previous study, we identified 21 client proteins for which clones were recovered, sometimes repeatedly. Here, we use sequence analysis and homology modeling of the client proteins to ascertain common sequence and structural properties that may contribute to binding affinity with the protective LEA protein. Our methods uncover what appears to be a predilection for protein-nucleic acid interactions among LEA client proteins, which is suggestive of subcellular residence. The results from this initial computational study will guide future efforts to uncover the protein protective mechanisms during heat stress, potentially leading to phage-display-directed evolution of synthetic LEA molecules.

  17. FcLDP1, a Gene Encoding a Late Embryogenesis Abundant (LEA) Domain Protein, Responds to Brassinosteroids and Abscisic Acid during the Development of Fruits in Fragaria chiloensis.

    PubMed

    Espinoza, Analía; Contreras, Rodrigo; Zúñiga, Gustavo E; Herrera, Raúl; Moya-León, María Alejandra; Norambuena, Lorena; Handford, Michael

    2016-01-01

    White Chilean strawberries (Fragaria chiloensis) are non-climacteric fruits, with an exotic color and aroma. In order to discover genes involved in the development of these fruits, we identified a fragment of a gene encoding a late embryogenesis abundant domain protein, FcLDP1, that was expressed in early stages of fruit development, particularly in receptacles. Hormones play key roles in regulating the development of non-climacteric fruits. We show that the brassinosteroid content of the white strawberry varies during development. Additionally, FcLDP1 as well as the closest ortholog in the woodland strawberry, F. vesca (FvLDP1) possess multiple brassinosteroid, as well as abscisic acid (ABA) response motifs in the promoter region, consistent with the response of transiently expressed FcLDP1 promoter-GFP fusions to these hormones, and the rise in FcLDP1 transcript levels in white strawberry fruits treated with brassinosteroids or ABA. These findings suggest that both hormones regulate FcLDP1 expression during the development of white strawberries.

  18. Capture and release of mixed acid gasses with binding organic liquids

    DOEpatents

    Heldebrant, David J.; Yonker, Clement R.

    2010-09-21

    Reversible acid-gas binding organic liquid systems that permit separation and capture of one or more of several acid gases from a mixed gas stream, transport of the liquid, release of the acid gases from the ionic liquid and reuse of the liquid to bind more acid gas with significant energy savings compared to current aqueous systems. These systems utilize acid gas capture compounds made up of strong bases and weak acids that form salts when reacted with a selected acid gas, and which release these gases when a preselected triggering event occurs. The various new materials that make up this system can also be included in various other applications such as chemical sensors, chemical reactants, scrubbers, and separators that allow for the specific and separate removal of desired materials from a gas stream such as flue gas.

  19. Abundance of Soil-Borne Entomopathogenic Fungi in Organic and Conventional Fields in the Midwestern USA with an Emphasis on the Effect of Herbicides and Fungicides on Fungal Persistence.

    PubMed

    Clifton, Eric H; Jaronski, Stefan T; Hodgson, Erin W; Gassmann, Aaron J

    2015-01-01

    Entomopathogenic fungi (EPF) are widespread in agricultural fields and help suppress crop pests. These natural enemies may be hindered by certain agronomic practices associated with conventional agriculture including the use of pesticides. We tested whether the abundance of EPF differed between organic and conventional fields, and whether specific cropping practices and soil properties were correlated with their abundance. In one year of the survey, soil from organic fields and accompanying margins had significantly more EPF than conventional fields and accompanying margins. Regression analysis revealed that the percentage of silt and the application of organic fertilizer were positively correlated with EPF abundance; but nitrogen concentration, tillage, conventional fields, and margins of conventional fields were negatively correlated with EPF abundance. A greenhouse experiment in which fungicides and herbicides were applied to the soil surface showed no significant effect on EPF. Though organic fields were perceived to be more suitable environments for EPF, abiotic factors and cropping practices such as tillage may have greater impacts on the abundance of EPF. Also, fungicides and herbicides may not be as toxic to soil-borne EPF as originally thought.

  20. Abundance of Soil-Borne Entomopathogenic Fungi in Organic and Conventional Fields in the Midwestern USA with an Emphasis on the Effect of Herbicides and Fungicides on Fungal Persistence

    PubMed Central

    Clifton, Eric H.; Jaronski, Stefan T.; Hodgson, Erin W.; Gassmann, Aaron J.

    2015-01-01

    Entomopathogenic fungi (EPF) are widespread in agricultural fields and help suppress crop pests. These natural enemies may be hindered by certain agronomic practices associated with conventional agriculture including the use of pesticides. We tested whether the abundance of EPF differed between organic and conventional fields, and whether specific cropping practices and soil properties were correlated with their abundance. In one year of the survey, soil from organic fields and accompanying margins had significantly more EPF than conventional fields and accompanying margins. Regression analysis revealed that the percentage of silt and the application of organic fertilizer were positively correlated with EPF abundance; but nitrogen concentration, tillage, conventional fields, and margins of conventional fields were negatively correlated with EPF abundance. A greenhouse experiment in which fungicides and herbicides were applied to the soil surface showed no significant effect on EPF. Though organic fields were perceived to be more suitable environments for EPF, abiotic factors and cropping practices such as tillage may have greater impacts on the abundance of EPF. Also, fungicides and herbicides may not be as toxic to soil-borne EPF as originally thought. PMID:26191815

  1. Strategies to reduce short-chain organic acids and synchronously establish high-rate composting in acidic household waste.

    PubMed

    Bergersen, Ove; Bøen, Anne S; Sørheim, Roald

    2009-01-01

    The aim of this study was to document whether addition of lime or increased amount of bulking agent would ensure, efficiently, a predictable composting process in acidic SSOW applicable in full scale plants. The results show that both lime addition and increasing the amount of bulking agent relative to waste support the development of high-rate respiration in composting. Both strategies are considered efficient in establishing desired microbial composting processes of acid household waste. Reduction in the content of different organic acids and loss on ignition were higher when more bulking agent was used compared with adding 5% lime to the acidic SSOW. Respiration was completely repressed in samples with 10% lime, where pH remained high. In addition fat and protein seem to degrade faster with increasing amount of bulking agent.

  2. Joint effect of organic acids and inorganic salts on cloud droplet activation

    NASA Astrophysics Data System (ADS)

    Frosch, M.; Prisle, N. L.; Bilde, M.; Varga, Z.; Kiss, G.

    2011-04-01

    We have investigated CCN properties of internally mixed particles composed of one organic acid (oxalic acid dihydrate, succinic acid, adipic acid, citric acid, cis-pinonic acid, or Nordic reference fulvic acid) and one inorganic salt (sodium chloride or ammonium sulphate). Surface tension and water activity of aqueous model solutions with concentrations relevant for CCN activation were measured using a tensiometer and osmometry, respectively. The measurements were used to calculate Köhler curves and critical supersaturations, which were compared to measured critical supersaturations of particles with the same chemical compositions, determined with a cloud condensation nucleus counter. Surfactant surface partitioning was not accounted for. For the aqueous solutions containing cis-pinonic acid and fulvic acid, a depression of surface tension was observed, but for the remaining solutions the effect on surface tension was negligible at concentrations relevant for cloud droplet activation. The surface tension depression of aqueous solutions containing both organic acid and inorganic salt was approximately the same as or smaller than that of aqueous solutions containing the same mass of the corresponding pure organic acids. Water activity was found to be highly dependent on the type and amount of inorganic salt. Sodium chloride was able to decrease water activity more than ammonium sulphate and both inorganic salts are predicted to have a smaller Raoult term than the studied organic acids. Increasing the mass ratio of the inorganic salt led to a decrease in water activity. Water activity measurements were compared to results from the E-AIM model and values estimated from both constant and variable van't Hoff factors. The correspondence between measurements and estimates was overall good, except for highly concentrated solutions. Critical supersaturations calculated with Köhler theory based on measured water activity and surface tension, but not accounting for surface

  3. Effect of organic acids on the growth and fermentation of ethanologenic Escherichia coli LY01

    SciTech Connect

    Zaldivar, J.; Ingram, L.O.

    1999-07-01

    Hemicellulose residues can be hydrolyzed into a sugar syrup using dilute mineral acids. Although this syrup represents a potential feedstock for biofuel production, toxic compounds generated during hydrolysis limit microbial metabolism. Escherichia coli LY01, an ethanologenic biocatalyst engineered to ferment the mixed sugars in hemicellulose syrups, has been tested for resistance to selected organic acids that re present in hemicellulose hydrolysates. Compounds tested include aromatic acids derived from lignin (ferulic, gallic, 4-hydroxybenzoic, syringic, and vanillic acids), acetic acid from the hydrolysis of acetylxylan, and others derived from sugar destruction (furoic, formic, levulinic, and caproic acids). Toxicity was related to hydrophobicity. Combinations of acids were roughly additive as inhibitors of cell growth. When tested at concentrations that inhibited growth by 80%, none appeared to strongly inhibit glycolysis and energy generation, or to disrupt membrane integrity. Toxicity was not markedly affected by inoculum size or incubation temperature. The toxicity of all acids except gallic acid was reduced by an increase in initial pH (from pH 6.0 to pH 7.0 to pH 8.0). Together, these results are consistent with the hypothesis that both aliphatic and mononuclear organic acids inhibit growth and ethanol production in LY01 by collapsing ion gradients and increasing internal anion concentrations.

  4. Halogenated methanesulfonic acids: A new class of organic micropollutants in the water cycle.

    PubMed

    Zahn, Daniel; Frömel, Tobias; Knepper, Thomas P

    2016-09-15

    Mobile and persistent organic micropollutants may impact raw and drinking waters and are thus of concern for human health. To identify such possible substances of concern nineteen water samples from five European countries (France, Switzerland, The Netherlands, Spain and Germany) and different compartments of the water cycle (urban effluent, surface water, ground water and drinking water) were enriched with mixed-mode solid phase extraction. Hydrophilic interaction liquid chromatography - high resolution mass spectrometry non-target screening of these samples led to the detection and structural elucidation of seven novel organic micropollutants. One structure could already be confirmed by a reference standard (trifluoromethanesulfonic acid) and six were tentatively identified based on experimental evidence (chloromethanesulfonic acid, dichloromethanesulfonic acid, trichloromethanesulfonic acid, bromomethanesulfonic acid, dibromomethanesulfonic acid and bromochloromethanesulfonic acid). Approximated concentrations for these substances show that trifluoromethanesulfonic acid, a chemical registered under the European Union regulation REACH with a production volume of more than 100 t/a, is able to spread along the water cycle and may be present in concentrations up to the μg/L range. Chlorinated and brominated methanesulfonic acids were predominantly detected together which indicates a common source and first experimental evidence points towards water disinfection as a potential origin. Halogenated methanesulfonic acids were detected in drinking waters and thus may be new substances of concern.

  5. Alteration of organic matter during infaunal polychaete gut passage and links to sediment organic geochemistry. Part I: Amino acids

    NASA Astrophysics Data System (ADS)

    Woulds, Clare; Middelburg, Jack J.; Cowie, Greg L.

    2012-01-01

    Of the factors which control the quantity and composition of organic matter (OM) buried in marine sediments, the links between infaunal ingestion and gut passage and sediment geochemistry have received relatively little attention. This study aimed to use feeding experiments and novel isotope tracing techniques to quantify amino acid net accumulation and loss during polychaete gut passage, and to link this to patterns of selective preservation and decay in sediments. Microcosms containing either Arenicolamarina or Hediste (formerly Nereis) diversicolor were constructed from defaunated sediment and filtered estuarine water, and maintained under natural temperature and light conditions. They were fed with 13C-labelled diatoms daily for 8 days, and animals were transferred into fresh, un-labelled sediment after ∼20 days. Samples of fauna, microcosm sediment and faecal matter were collected after 8, ∼20 and ∼40 days, and analysed for their bulk isotopic signatures and 13C-labelled amino acid compositions. Bulk isotopic data showed that, consistent with their feeding modes, Hediste assimilated added 13C more quickly, and attained a higher labelling level than Arenicola. Both species retained the added 13C in their biomass even after removal from the food. A principal component analysis of 13C-labelled amino acid mole percentages showed clear differences in composition between the algae, faunal tissues, and sediment plus faecal matter. Further, the two species of polychaete showed different compositions in their tissues. The amino acids phenylalanine, valine, leucine, iso-leucine, threonine and proline showed net accumulation in polychaete tissues. Serine, methionine, lysine, aspartic and glutamic acids and tyrosine were rapidly lost through metabolism, consistent with their presence in easily digestible cell components (as opposed to cell walls which offer physical protection). All sample types (polychaete tissues, sediments and faecal matter) were enriched in

  6. Design of homo-organic acid producing strains using multi-objective optimization.

    PubMed

    Kim, Tae Yong; Park, Jong Myoung; Kim, Hyun Uk; Cho, Kwang Myung; Lee, Sang Yup

    2015-03-01

    Production of homo-organic acids without byproducts is an important challenge in bioprocess engineering to minimize operation cost for separation processes. In this study, we used multi-objective optimization to design Escherichia coli strains with the goals of maximally producing target organic acids, while maintaining sufficiently high growth rate and minimizing the secretion of undesired byproducts. Homo-productions of acetic, lactic and succinic acids were targeted as examples. Engineered E. coli strains capable of producing homo-acetic and homo-lactic acids could be developed by taking this systems approach for the minimal identification of gene knockout targets. Also, failure to predict effective gene knockout targets for the homo-succinic acid production suggests that the multi-objective optimization is useful in assessing the suitability of a microorganism as a host strain for the production of a homo-organic acid. The systems metabolic engineering-based approach reported here should be applicable to the production of other industrially important organic acids.

  7. Water-enhanced solubility of carboxylic acids in organic solvents and its application to extraction processes

    SciTech Connect

    Starr, J.N. ); King, C.J. )

    1992-11-01

    This paper reports on solubilities of carboxylic acids in certain organic solvents which increase sharply as the concentration of water in the solvent increases. This phenomenon leads to a method of regeneration for solvent-extraction processes whereby coextracted water is selectively removed from the extract, such as by stripping, thereby precipitating the acid. The removal of a minor constituent to cause precipitation reduces energy consumption, in contrast with bulk removal of solvent. Solubilities of fumaric acid were measured in a number of organic solvents, with varying amounts of water in the organic phase. Cyclohexanone and methylcyclohexanone were chosen as solvents for which detailed solid-liquid and liquid-liquid equilibria were measured for adipic, fumaric, and succinic acids in the presence of varying concentrations of water, at both 25 and 45[degrees]C. Batch precipitation experiments were performed to demonstrate the processing concept and determine the relative volatility of water to solvent in the presence of carbon.

  8. In vitro susceptibility of Brachyspira hyodysenteriae to organic acids and essential oil components

    PubMed Central

    VANDE MAELE, Lien; HEYNDRICKX, Marc; MAES, Dominiek; DE PAUW, Nele; MAHU, Maxime; VERLINDEN, Marc; HAESEBROUCK, Freddy; MARTEL, An; PASMANS, Frank; BOYEN, Filip

    2015-01-01

    The antibacterial potential of organic acids and essential oil components against Brachyspira hyodysenteriae, the causative pathogen of swine dysentery, was evaluated. Minimum inhibitory concentrations (MIC) of 15 compounds were determined at pH 7.2 and pH 6.0, using a broth microdilution assay. In addition, possible synergism was determined. MIC values for the three tested strains were similar. For organic acids, MIC values at pH 6.0 were lower than at pH 7.2. B. hyodysenteriae was most sensitive to cinnamaldehyde and lauric acid, with MIC values <1.5 mM. Most antibacterial effects of binary combinations were additive, however, for thymol and carvacrol, synergism could be observed. In vitro results demonstrate the antibacterial action of certain essential oil components and organic acids against B. hyodysenteriae. PMID:26369432

  9. Examination of Organic Reactions in UT/LS Aerosols: Temperature Dependence in Sulfuric Acid Solution

    NASA Astrophysics Data System (ADS)

    Iraci, L. T.; Michelsen, R. R.

    2004-12-01

    Sulfuric acid has been used for decades as an industrial catalyst for organic reactions, but its parallel role in atmospheric aerosols is relatively unexplored, despite identification of a wide array of organic compounds in particles. Several recent studies have demonstrated possible reactions in acidic particles, generally involving carbonyl groups (C=O) and leading to the formation of larger molecules. Reactions of oxygenated organic compounds in acidic solution are most often studied near room temperature, while the sulfate particles of the upper troposphere and lower stratosphere are significantly colder. Our studies of ethanal (acetaldehyde) suggest that reactivity in ~50 wt% H2SO4 solutions may be enhanced at lower temperatures, contrary to expectations. We will present temperature-dependent results of acid catalyzed condensation reactions, leading to formation of higher molecular weight products. Implications for aerosol composition and reactivity will be discussed.

  10. Effect of organic acids found in cottonseed hull hydrolysate on the xylitol fermentation by Candida tropicalis.

    PubMed

    Wang, Le; Wu, Dapeng; Tang, Pingwah; Yuan, Qipeng

    2013-08-01

    Five organic acids (acetic, ferulic, 4-hydroxybenzoic, formic and levulinic acids) typically associated in the hemicellulose hydrolysate were selected to study their effects on the xylitol fermentation. The effects of individual and combined additions were independently evaluated on the following parameters: inhibitory concentration; initial cell concentration; pH value; and membrane integrity. The results showed that the toxicities of organic acids were related to their hydrophobility and significantly affected by the fermentative pH value. In addition, it was revealed that the paired combinations of organic acids did not impose synergetic inhibition. Moreover, it was found that the fermentation inhibition could be alleviated with the simple manipulations by increasing the initial cell concentration, raising the initial pH value and minimizing furfural levels by evaporation during the concentration of hydrolysates. The proposed strategies for minimizing the negative effects could be adopted to improve the xylitol fermentation in the industrial applications.

  11. In vitro susceptibility of Brachyspira hyodysenteriae to organic acids and essential oil components.

    PubMed

    Vande Maele, Lien; Heyndrickx, Marc; Maes, Dominiek; De Pauw, Nele; Mahu, Maxime; Verlinden, Marc; Haesebrouck, Freddy; Martel, An; Pasmans, Frank; Boyen, Filip

    2016-02-01

    The antibacterial potential of organic acids and essential oil components against Brachyspira hyodysenteriae, the causative pathogen of swine dysentery, was evaluated. Minimum inhibitory concentrations (MIC) of 15 compounds were determined at pH 7.2 and pH 6.0, using a broth microdilution assay. In addition, possible synergism was determined. MIC values for the three tested strains were similar. For organic acids, MIC values at pH 6.0 were lower than at pH 7.2. B. hyodysenteriae was most sensitive to cinnamaldehyde and lauric acid, with MIC values <1.5 mM. Most antibacterial effects of binary combinations were additive, however, for thymol and carvacrol, synergism could be observed. In vitro results demonstrate the antibacterial action of certain essential oil components and organic acids against B. hyodysenteriae.

  12. Amino Acids Hydrolyzed from Animal Carcasses Are a Good Additive for the Production of Bio-organic Fertilizer

    PubMed Central

    Liu, Hongjun; Chen, Dandan; Zhang, Ruifu; Hang, Xinnan; Li, Rong; Shen, Qirong

    2016-01-01

    High-quality bio-organic fertilizers (BIOs) cannot be produced without the addition of some proteins. In this study, compound liquid amino acids (CLAA) from animal carcasses were utilized as additives into matured composts to create novel BIOs containing plant growth-promoting rhizobacteria (PGPR). The results showed that adding CLAA and inoculating bacteria meanwhile resulted in failed solid-state fermentation (SSF) due to the higher H+ contents. While after pre-compost for 4 days before PGPR inoculation, treatments of matured chicken or pig manure added with 0.2 ml g-1 of CLAA resulted in a maximum biomass of functional strains. Illumine-MiSeq sequencing and Real-Time PCR results showed that the CLAA addition decreased the bacterial abundance and richness, altered the bacterial community structure and changed the relative abundance of some microbial groups. This study offers a high value-added utilization of waste protein resources for producing economical, high-quality BIO. PMID:27574521

  13. Enhanced characterization of oil sands acid-extractable organics fractions using electrospray ionization-high-resolution mass spectrometry and synchronous fluorescence spectroscopy.

    PubMed

    Bauer, Anthony E; Frank, Richard A; Headley, John V; Peru, Kerry M; Hewitt, L Mark; Dixon, D George

    2015-05-01

    The open pit oil sands mining operations north of Fort McMurray, Alberta, Canada, are accumulating tailings waste at a rate approximately equal to 4.9 million m(3) /d. Naphthenic acids are among the most toxic components within tailings to aquatic life, but structural components have largely remained unidentified. In the present study, electrospray ionization high-resolution mass spectrometry (ESI-HRMS) and synchronous fluorescence spectroscopy (SFS) were used to characterize fractions derived from the distillation of an acid-extractable organics (AEO) mixture isolated from oil sands process-affected water (OSPW). Mean molecular weights of each fraction, and their relative proportions to the whole AEO extract, were as follows: fraction 1: 237 Da, 8.3%; fraction 2: 240 Da, 23.8%; fraction 3: 257 Da, 26.7%; fraction 4: 308 Da, 18.9%; fraction 5: 355 Da, 10.0%. With increasing mean molecular weight of the AEO fractions, a concurrent increase occurred in the relative abundance of nitrogen-, sulfur-, and oxygen-containing ions, double-bond equivalents, and degree of aromaticity. Structures present in the higher-molecular-weight fractions (fraction 4 and fraction 5) suggested the presence of heteroatoms, dicarboxyl and dihydroxy groups, and organic acid compounds with the potential to function as estrogens. Because organic acid compositions become dominated by more recalcitrant, higher-molecular-weight acids during natural degradation, these findings are important in the context of oil sands tailings pond water remediation.

  14. Six hydrogen-bonded supramolecular frameworks assembled from organic acids and p-dimethylaminobenzaldehyde

    NASA Astrophysics Data System (ADS)

    Jin, Shouwen; Wang, Lanqing; Lou, Yulei; Liu, Li; Li, Bin; Li, Linyu; Feng, Chao; Liu, Hui; Wang, Daqi

    2016-03-01

    Cocrystallization of the commonly available organic compound, p-dimethylaminobenzaldehyde, with a series of organic acids gave a total of six molecular adducts with the compositions: p-dimethylaminobenzaldehyde : (3,5-dinitrosalicylic acid) [(L) · (Hdsa), Hdsa = 3,5-dinitrosalicylic acid] (1), p-dimethylaminobenzaldehyde : (3-nitrophthalic acid) [(L) · (3-H2npa), 3-H2npa = 3-nitrophthalic acid] (2), p-dimethylaminobenzaldehyde : (4-nitrophthalic acid) [(L) · (4-H2npa), 4-H2npa = 4-nitrophthalic acid] (3), p-dimethylaminobenzaldehyde : (1,5-naphthalenedisulfonic acid) : (NH3)2 [NH4 · (HL) · (nds2-) · NH3, nds- = 1,5-naphthalenedisulfonate] (4), p-dimethylaminobenzaldehyde : (oxalic acid)0.5 [(L) · (H2oa)0.5, H2oa = oxalic acid] (5), and p-dimethylaminobenzaldehyde : (fumaric acid)0.5 [(L) · (H2fum)0.5, H2fum = fumaric acid] (6). The six molecular adducts have been characterized by X-ray diffraction technique, IR, and elemental analysis, and the melting points of all adducts were also reported. And their structural and supramolecular aspects are fully analyzed. Of the six adducts, only 4 is an organic salt and the other five are cocrystals. The crystal packing is interpreted in terms of the strong classical hydrogen bonds as well as other weak non-classical hydrogen bonds. The different families of non-covalent bonds contribute to the stabilization and expansion of the total high-dimensional (2D-3D) frameworks.

  15. Nickel Deficiency Disrupts Metabolism of Ureides, Amino Acids, and Organic Acids of Young Pecan Foliage[OA

    PubMed Central

    Bai, Cheng; Reilly, Charles C.; Wood, Bruce W.

    2006-01-01

    The existence of nickel (Ni) deficiency is becoming increasingly apparent in crops, especially for ureide-transporting woody perennials, but its physiological role is poorly understood. We evaluated the concentrations of ureides, amino acids, and organic acids in photosynthetic foliar tissue from Ni-sufficient (Ni-S) versus Ni-deficient (Ni-D) pecan (Carya illinoinensis [Wangenh.] K. Koch). Foliage of Ni-D pecan seedlings exhibited metabolic disruption of nitrogen metabolism via ureide catabolism, amino acid metabolism, and ornithine cycle intermediates. Disruption of ureide catabolism in Ni-D foliage resulted in accumulation of xanthine, allantoic acid, ureidoglycolate, and citrulline, but total ureides, urea concentration, and urease activity were reduced. Disruption of amino acid metabolism in Ni-D foliage resulted in accumulation of glycine, valine, isoleucine, tyrosine, tryptophan, arginine, and total free amino acids, and lower concentrations of histidine and glutamic acid. Ni deficiency also disrupted the citric acid cycle, the second stage of respiration, where Ni-D foliage contained very low levels of citrate compared to Ni-S foliage. Disruption of carbon metabolism was also via accumulation of lactic and oxalic acids. The results indicate that mouse-ear, a key morphological symptom, is likely linked to the toxic accumulation of oxalic and lactic acids in the rapidly growing tips and margins of leaflets. Our results support the role of Ni as an essential plant nutrient element. The magnitude of metabolic disruption exhibited in Ni-D pecan is evidence of the existence of unidentified physiological roles for Ni in pecan. PMID:16415214

  16. Yearly trend of dicarboxylic acids in organic aerosols from south of Sweden and source attribution

    NASA Astrophysics Data System (ADS)

    Hyder, Murtaza; Genberg, Johan; Sandahl, Margareta; Swietlicki, Erik; Jönsson, Jan Åke

    2012-09-01

    Seven aliphatic dicarboxylic acids (C3-C9) along with phthalic acid, pinic acid and pinonic acid were determined in 35 aerosol (PM10) samples collected over the year at Vavihill sampling station in south of Sweden. Mixture of dichloromethane and methanol (ratio 1:3) was preferred over water for extraction of samples and extraction was assisted by ultrasonic agitation. Analytes were derivatized using N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) containing 1% trimethylsilyl chloride and analyzed using gas chromatography/mass spectrometry. Among studied analytes, azelaic acid was found maximum with an average concentration of 6.0 ± 3.6 ng m-3 and minimum concentration was found for pimelic acid (1.06 ± 0.63 ng m-3). A correlation coefficients analysis was used for defining the possible sources of analytes. Higher dicarboxylic acids (C7-C9) showed a strong correlation with each other (correlation coefficients (r) range, 0.96-0.97). Pinic and pinonic acids showed an increase in concentration during summer. Lower carbon number dicarboxylic acids (C3-C6) and phthalic acid were found strongly correlated, but showed a poor correlation with higher carbon number dicarboxylic acids (C7-C9), suggesting a different source for them. Biomass burning, vehicle exhaust, photo-oxidation of volatile organic compounds (natural and anthropogenic emissions) were possible sources for dicarboxylic acids.

  17. Synergistic effect of thymol and carvacrol combined with chelators and organic acids against Salmonella Typhimurium.

    PubMed

    Zhou, Feng; Ji, Baoping; Zhang, Hong; Jiang, Hui; Yang, Zhiwei; Li, Jingjing; Li, Jihai; Ren, Yali; Yan, Wenjie

    2007-07-01

    To identify synergistic combinations of different food additives, the antimicrobial effects of thymol and carvacrol against Salmonella Typhimurium were assessed alone and in combination with various other preservatives including EDTA, acetic acid, lactic acid, and citric acid. Overall, growth of Salmonella Typhimurium was significantly inhibited in Mueller-Hinton broth containing thymol, carvacrol, EDTA, acetic acid, lactic acid, or citric acid at concentrations of 400 mg/liter, 400 microl/liter, 300 mg/liter, 0.2% (vol/vol), 0.2% (vol/vol), and 0.2% (wt/vol), respectively. The combination of different antimicrobials such as thymol or carvacrol with EDTA, thymol or carvacrol with acetic acid, and thymol or carvacrol with citric acid all resulted in significantly reduced populations of Salmonella Typhimurium. In samples treated with combinations, these antimicrobials had synergistic effects compared with samples treated with thymol, carvacrol, EDTA, acetic acid, or citric acid alone. However, the combined use of lactic acid with thymol or carvacrol did not produce a synergistic effect against Salmonella Typhimurium. Thus, some chelators or organic acids can be used as food preservatives in combination with thymol and carvacrol to reduce the concentrations needed to produce an adequate antimicrobial effect.

  18. Characterization of an organic acid analog model in Adirondack, New York, surface waters

    NASA Astrophysics Data System (ADS)

    Fakhraei, H.; Driscoll, C. T.

    2013-12-01

    Natural waters include a variety of organic matter that differs in composition and functional groups. Dissolved organic matter is important but difficult to characterize acidic and metal binding (e.g., Al) functional groups in chemical equilibrium models. In this study data from Adirondack Lake Survey were used to calibrate an organic acid analog model in order to quantify the influence of organic acids on surface water chemistry. The study sites in the Adirondack region of New York have diverse levels of dissolved organic carbon (DOC), used as a surrogate for organic acids. DOC in 55 Adirondack surface waters varies from 180 μmol C/l (in Little Echo Pond) to 1263 μmol C/l (in Sunday Pond). To reduce the variability inherited in the large raw data set, suite of mean observations was constructed by grouping and averaging measured data into pH intervals of 0.05 pH units from pH 4.15 to 7.3. A chemical equilibrium model, which includes major solutes in natural waters, was linked to an optimization algorithm (genetic algorithm) to calibrate a triprotic organic analog model which includes proton and aluminum binding by adjusting the dissociation constants and site density of DOC. The object of fitting procedure was to simultaneously minimize the discrepancy between observed and simulated pH, acid neutralizing capacity (ANC), organic monomeric aluminum and inorganic monomeric aluminum. A sensitivity analysis on calibrated values indicate that the speciation of the modeled solutes are most responsive to the dissociation constant of AlOrg= Al3+ + Org3- reaction (Org3- represents organic anion), the site density of DOC and the second H+ dissociation constant of the triprotic organic analog (i.e. H2Org- = 2H+ + Org3- reaction).

  19. Microbial production of specialty organic acids from renewable and waste materials.

    PubMed

    Alonso, Saúl; Rendueles, Manuel; Díaz, Mario

    2015-01-01

    Microbial production of organic acids has become a fast-moving field due to the increasing role of these compounds as platform chemicals. In recent years, the portfolio of specialty fermentation-derived carboxylic acids has increased considerably, including the production of glyceric, glucaric, succinic, butyric, xylonic, fumaric, malic, itaconic, lactobionic, propionic and adipic acid through innovative fermentation strategies. This review summarizes recent trends in the use of novel microbial platforms as well as renewable and waste materials for efficient and cost-effective bio-based production of emerging high-value organic acids. Advances in the development of robust and efficient microbial bioprocesses for producing carboxylic acids from low-cost feedstocks are also discussed. The industrial market scenario is also reviewed, including the latest information on the stage of development for producing these emerging bio-products via large-scale fermentation.

  20. The effects of different thermal treatments and organic acid levels on nutrient digestibility in broilers.

    PubMed

    Goodarzi Boroojeni, F; Mader, A; Knorr, F; Ruhnke, I; Röhe, I; Hafeez, A; Männer, K; Zentek, J

    2014-05-01

    Poultry feed is a potential vector for pathogens. Heat processing and organic acid treatments may decontaminate feed and can affect bird performance as well as feed digestibility. The present study was performed to investigate the effect of different thermal treatments including pelleting (P), long-term conditioning at 85°C for 3 min (L), or expanding at 110°C (E110) and 130°C for 3 to 5 s (E130) without or with 0.75 and 1.5% organic acid supplementation (63.75% formic acid, 25.00% propionic acid, and 11.25% water) on performance, nutrient digestibility, and organ weights of broilers. In total, 960 one-day-old broiler chicks were randomly assigned to 8 replicates using a 3 × 4 factorial arrangement. Performance variables were determined, and the relative organ weights and ileal and total amino acid (AA) digestibilities were measured at d 35. The organic acid inclusion linearly improved feed efficiency in the first week (P ≤ 0.05). The acid inclusion levels and thermal treatments had no significant effect on the performance variables at later intervals of the growing period of the birds. The L group showed the lowest ileal AA and CP digestibility. The inclusion of organic acids had a quadratic effect on total and ileal digestibility of isoleucine (P ≤ 0.05), whereas it had no significant effect on the ileal digestibility of other AA and nutrients. The relative weights of the jejunum and small intestine were significantly higher in the E130 group compared with P and L (P ≤ 0.05). In conclusion, our study demonstrated that long-term heat conditioning can decrease ileal nutrient digestibility, whereas pelleting and expansion, independently of organic acid addition, seemed to have no negative impact on broiler performance and nutrient digestibilities. Moreover, adding a blend of organic acids to broiler diets had neither positive nor negative effects on nutrient digestibility and final broiler performance. This indicates the feasibility of short-term thermal

  1. Short interspersed nuclear elements (SINEs) are abundant in Solanaceae and have a family-specific impact on gene structure and genome organization.

    PubMed

    Seibt, Kathrin M; Wenke, Torsten; Muders, Katja; Truberg, Bernd; Schmidt, Thomas

    2016-05-01

    Short interspersed nuclear elements (SINEs) are highly abundant non-autonomous retrotransposons that are widespread in plants. They are short in size, non-coding, show high sequence diversity, and are therefore mostly not or not correctly annotated in plant genome sequences. Hence, comparative studies on genomic SINE populations are rare. To explore the structural organization and impact of SINEs, we comparatively investigated the genome sequences of the Solanaceae species potato (Solanum tuberosum), tomato (Solanum lycopersicum), wild tomato (Solanum pennellii), and two pepper cultivars (Capsicum annuum). Based on 8.5 Gbp sequence data, we annotated 82 983 SINE copies belonging to 10 families and subfamilies on a base pair level. Solanaceae SINEs are dispersed over all chromosomes with enrichments in distal regions. Depending on the genome assemblies and gene predictions, 30% of all SINE copies are associated with genes, particularly frequent in introns and untranslated regions (UTRs). The close association with genes is family specific. More than 10% of all genes annotated in the Solanaceae species investigated contain at least one SINE insertion, and we found genes harbouring up to 16 SINE copies. We demonstrate the involvement of SINEs in gene and genome evolution including the donation of splice sites, start and stop codons and exons to genes, enlargement of introns and UTRs, generation of tandem-like duplications and transduction of adjacent sequence regions.

  2. Design Principles for High H2 Storage Using Chelation of Abundant Transition Metals in Covalent Organic Frameworks for 0-700 bar at 298 K.

    PubMed

    Pramudya, Yohanes; Mendoza-Cortes, Jose L

    2016-11-23

    Physisorption is an effective route to meet hydrogen gas (H2) storage and delivery requirements for transportation because it is fast and fully reversible under mild conditions. However, most current candidates have too small binding enthalpies to H2 which leads to volumetric capacity less than 10 g/L compared to that of the system target of 40 g/L at 298 K. Accurate quantum mechanical (QM) methods were used to determine the H2 binding enthalpy of 5 linkers which were chelated with 11 different transition metals (Tm), including abundant first-row Tm (Sc through Cu), totaling 60 molecular compounds with more than 4 configurations related to the different number of H2 that interact with the molecular compound. It was found that first-row Tm gave similar and sometimes superior van der Waals interactions with H2 than precious Tm. Based on these linkers, 30 new covalent organic frameworks (COFs) were constructed. The H2 uptakes of these new COFs were determined using quantum mechanics (QM)-based force fields and grand canonical Monte Carlo (GCMC) simulations. For the first time, the range for the adsorption pressure was explored for 0-700 bar and 298 K. It was determined that Co-, Ni-, and Fe-based COFs can give high H2 uptake and delivery when compared to bulk H2 on this unexplored range of pressure.

  3. Expanding the modular ester fermentative pathways for combinatorial biosynthesis of esters from volatile organic acids.

    PubMed

    Layton, Donovan S; Trinh, Cong T

    2016-08-01

    Volatile organic acids are byproducts of fermentative metabolism, for example, anaerobic digestion of lignocellulosic biomass or organic wastes, and are often times undesired inhibiting cell growth and reducing directed formation of the desired products. Here, we devised a general framework for upgrading these volatile organic acids to high-value esters that can be used as flavors, fragrances, solvents, and biofuels. This framework employs the acid-to-ester modules, consisting of an AAT (alcohol acyltransferase) plus ACT (acyl CoA transferase) submodule and an alcohol submodule, for co-fermentation of sugars and organic acids to acyl CoAs and alcohols to form a combinatorial library of esters. By assembling these modules with the engineered Escherichia coli modular chassis cell, we developed microbial manufacturing platforms to perform the following functions: (i) rapid in vivo screening of novel AATs for their catalytic activities; (ii) expanding combinatorial biosynthesis of unique fermentative esters; and (iii) upgrading volatile organic acids to esters using single or mixed cell cultures. To demonstrate this framework, we screened for a set of five unique and divergent AATs from multiple species, and were able to determine their novel activities as well as produce a library of 12 out of the 13 expected esters from co-fermentation of sugars and (C2-C6) volatile organic acids. We envision the developed framework to be valuable for in vivo characterization of a repertoire of not-well-characterized natural AATs, expanding the combinatorial biosynthesis of fermentative esters, and upgrading volatile organic acids to high-value esters. Biotechnol. Bioeng. 2016;113: 1764-1776. © 2016 Wiley Periodicals, Inc.

  4. Transport and cycling of iron and hydrogen peroxide in a freshwater stream: Influence of organic acids

    USGS Publications Warehouse

    Scott, D.T.; Runkel, R.L.; McKnight, Diane M.; Voelker, B.M.; Kimball, B.A.; Carraway, E.R.

    2003-01-01

    An in-stream injection of two dissolved organic acids (phthalic and aspartic acids) was performed in an acidic mountain stream to assess the effects of organic acids on Fe photoreduction and H2O2 cycling. Results indicate that the fate of Fe is dependent on a net balance of oxidative and reductive processes, which can vary over a distance of several meters due to changes in incident light and other factors. Solution phase photoreduction rates were high in sunlit reaches and were enhanced by the organic acid addition but were also limited by the amount of ferric iron present in the water column. Fe oxide photoreduction from the streambed and colloids within the water column resulted in an increase in the diurnal load of total filterable Fe within the experimental reach, which also responded to increases in light and organic acids. Our results also suggest that Fe(II) oxidation increased in response to the organic acids, with the result of offsetting the increase in Fe(II) from photoreductive processes. Fe(II) was rapidly oxidized to Fe(III) after sunset and during the day within a well-shaded reach, presumably through microbial oxidation. H2O 2, a product of dissolved organic matter photolysis, increased downstream to maximum concentrations of 0.25 ??M midday. Kinetic calculations show that the buildup of H2O2 is controlled by reaction with Fe(III), but this has only a small effect on Fe(II) because of the small formation rates of H2O2 compared to those of Fe(II). The results demonstrate the importance of incorporating the effects of light and dissolved organic carbon into Fe reactive transport models to further our understanding of the fate of Fe in streams and lakes.

  5. Amino acid transporter mutants of Arabidopsis provides evidence that a non-mycorrhizal plant acquires organic nitrogen from agricultural soil.

    PubMed

    Ganeteg, Ulrika; Ahmad, Iftikhar; Jämtgård, Sandra; Aguetoni-Cambui, Camila; Inselsbacher, Erich; Svennerstam, Henrik; Schmidt, Susanne; Näsholm, Torgny

    2017-03-01

    Although organic nitrogen (N) compounds are ubiquitous in soil solutions, their potential role in plant N nutrition has been questioned. We performed a range of experiments on Arabidopsis thaliana genetically modified to enhance or reduce root uptake of amino acids. Plants lacking expression of the Lysine Histidine Transporter 1 (LHT1) displayed significantly lower contents of (13) C and (15) N label and of U-(13) C5 ,(15) N2 L-glutamine, as determined by liquid chromatography-mass spectrometry when growing in pots and supplied with dually labelled L-glutamine compared to wild type plants and LHT1-overexpressing plants. Slopes of regressions between accumulation of (13) C-labelled carbon and (15) N-labelled N were higher for LHT1-overexpressing plants than wild type plants, while plants lacking expression of LHT1 did not display a significant regression between the two isotopes. Uptake of labelled organic N from soil tallied with that of labelled ammonium for wild type plants and LHT1-overexpressing plants but was significantly lower for plants lacking expression of LHT1. When grown on agricultural soil plants lacking expression of LHT1 had the lowest, and plants overexpressing LHT1 the highest C/N ratios and natural δ(15) N abundance suggesting their dependence on different N pools. Our data show that LHT1 expression is crucial for plant uptake of organic N from soil.

  6. Synthesis and characterisation of Gd2O3 nanocrystals functionalised by organic acids.

    PubMed

    Söderlind, Fredrik; Pedersen, Henrik; Petoral, Rodrigo M; Käll, Per-Olov; Uvdal, Kajsa

    2005-08-01

    Nanocrystals of Gd2O3 have been prepared by various methods, using, e.g., trioctylphosphine oxide (TOPO), diethylene glycol (DEG) or glycine. The crystalline particles were of sizes 5 to 15 nm. Different carboxylic acids, e.g., oleic acid or citric acid, were adsorbed onto the surface of the particles made with DEG. IR measurements show that the molecules coordinate to the Gd2O3 surface via the carboxylate group in a bidentate or bridging manner. The organic-acid/particle complexes were characterised by XRPD, TEM, FTIR, Raman, and XPS.

  7. Bifunctional Organic Polymeric Catalysts with a Tunable Acid-Base Distance and Framework Flexibility

    PubMed Central

    Chen, Huanhui; Wang, Yanan; Wang, Qunlong; Li, Junhui; Yang, Shiqi; Zhu, Zhirong

    2014-01-01

    Acid-base bifunctional organic polymeric catalysts were synthesized with tunable structures. we demonstrated two synthesis approaches for structural fine-tune. In the first case, the framework flexibility was tuned by changing the ratio of rigid blocks to flexible blocks within the polymer framework. In the second case, we precisely adjusted the acid-base distance by distributing basic monomers to be adjacent to acidic monomers, and by changing the chain length of acidic monomers. In a standard test reaction for the aldol condensation of 4-nitrobenzaldehyde with acetone, the catalysts showed good reusability upon recycling and maintained relatively high conversion percentage. PMID:25267260

  8. A note on the prebiotic synthesis of organic acids in carbonaceous meteorites

    NASA Technical Reports Server (NTRS)

    Kerridge, John F.

    1991-01-01

    Strong similarities between monocarboxylic and hydrocarboxylic acids in the Murchison meteorite suggest corresponding similarities in their origins. However, various lines of evidence apparently implicate quite different precursor compounds in the synthesis of the different acids. These seeming inconsistencies can be resolved by postulating that the apparent precursors also share a related origin. Pervasive D enrichment indicates that this origin was in a presolar molecular cloud. The organic acids themselves were probably synthesized in an aqueous environment on an asteroidal parent body, the hydroxy (and amino) acids by means of the Strecker cyanohydrin reaction.

  9. Characterisation of Fe-oxide nanoparticles coated with humic acid and Suwannee River natural organic matter.

    PubMed

    Chekli, Laura; Phuntsho, Sherub; Roy, Maitreyee; Shon, Ho Kyong

    2013-09-01

    Iron oxide nanoparticles are becoming increasingly popular for various applications including the treatment of contaminated soil and groundwater; however, their mobility and reactivity in the subsurface environment are significantly affected by their tendency to aggregate. One solution to overcome this issue is to coat the nanoparticles with dissolved organic matter (DOM). The advantages of DOM over conventional surface modifiers are that DOM is naturally abundant in the environment, inexpensive, non-toxic and readily adsorbed onto the surface of metal oxide nanoparticles. In this study, humic acid (HA) and Suwannee River natural organic matter (SRNOM) were tested and compared as surface modifiers for Fe2O3 nanoparticles (NPs). The DOM-coated Fe2O3 NPs were characterised by various analytical methods including: flow field-flow fractionation (FlFFF), high performance size exclusion chromatography (HPSEC) and Fourier transform infrared spectroscopy (FTIR). The stability of the coated NPs was then evaluated by assessing their aggregation and disaggregation behaviour over time. Results showed that both HA and SRNOM were rapidly and readily adsorbed on the surface of Fe2O3 NPs, providing electrosteric stabilisation over a wide range of pH. HPSEC results showed that the higher molecular weight components of DOM were preferentially adsorbed onto the surface of Fe2O3. As SRNOM consists of macromolecules with a higher molecular weight than HA, the measured size of the SRNOM-coated Fe2O3 NPs was 30% larger than the HA-coated Fe2O3 NPs. FTIR results indicated the occurrence of hydrogen bonding arising from electrostatic interaction between the DOM and Fe2O3 NPs. Finally, a stability study showed that after 14 days, small agglomerates and aggregates were formed. The HA-coated Fe2O3 NPs formed agglomerates which were easily disaggregated using a vortex mixer, with the coated NPs returning to their initial size. However, SRNOM-coated Fe2O3 NPs were only partially disaggregated

  10. Role of Organic Acids in Bioformation of Kaolinite: Results of Laboratory Experiments

    NASA Astrophysics Data System (ADS)

    Bontognali, T. R. R.; Vasconcelos, C.; McKenzie, J. A.

    2012-04-01

    Clay minerals and other solid silica phases have a broad distribution in the geological record and greatly affect fundamental physicochemical properties of sedimentary rocks, including porosity. An increasing number of studies suggests that microbial activity and microbially produced organic acids might play an important role in authigenic clay mineral formation, at low temperatures and under neutral pH conditions. In particular, early laboratory experiments (Linares and Huertas, 1971) reported the precipitation of kaolinite in solutions of SiO2 and Al2O3 with different molar ratios SiO2/Al2O3, together with fulvic acid (a non-characterized mixture of many different acids containing carboxyl and phenolate groups) that was extracted from peat soil. Despite many attempts, these experiments could not be reproduced until recently. Fiore et al. (2011) hypothesized that the non-sterile fulvic acid might have contained microbes that participated in the formation of kaolinite. Using solutions saturated with Si and Al and containing oxalate and/or mixed microbial culture extracted from peat-moss soil, they performed incubation experiments, which produced kaolinite exclusively in solutions containing oxalate and microbes. We proposed to test the role of specific organic acids for kaolinite formation, conducting laboratory experiments at 25˚C, with solutions of sodium silicate, aluminum chloride and various organic compounds (i.e. EDTA, citric acid, succinic acid and oxalic acid). Specific organic acids may stabilize aluminum in octahedral coordination positions, which is crucial for the initial nucleation step. In our experiments, a poorly crystalline mineral that is possibly a kaolinite precursor formed exclusively in the presence of succinic acid. In experiments with other organic compounds, no incorporation of Al was observed, and amorphous silica was the only precipitated phase. In natural environments, succinic acid is produced by a large variety of microbes as an

  11. Spatially-interactive biomolecular networks organized by nucleic acid nanostructures.

    PubMed

    Fu, Jinglin; Liu, Minghui; Liu, Yan; Yan, Hao

    2012-08-21

    Living systems have evolved a variety of nanostructures to control the molecular interactions that mediate many functions including the recognition of targets by receptors, the binding of enzymes to substrates, and the regulation of enzymatic activity. Mimicking these structures outside of the cell requires methods that offer nanoscale control over the organization of individual network components. Advances in DNA nanotechnology have enabled the design and fabrication of sophisticated one-, two- and three-dimensional (1D, 2D, and 3D) nanostructures that utilize spontaneous and sequence-specific DNA hybridization. Compared with other self-assembling biopolymers, DNA nanostructures offer predictable and programmable interactions and surface features to which other nanoparticles and biomolecules can be precisely positioned. The ability to control the spatial arrangement of the components while constructing highly organized networks will lead to various applications of these systems. For example, DNA nanoarrays with surface displays of molecular probes can sense noncovalent hybridization interactions with DNA, RNA, and proteins and covalent chemical reactions. DNA nanostructures can also align external molecules into well-defined arrays, which may improve the resolution of many structural determination methods, such as X-ray diffraction, cryo-EM, NMR, and super-resolution fluorescence. Moreover, by constraint of target entities to specific conformations, self-assembled DNA nanostructures can serve as molecular rulers to evaluate conformation-dependent activities. This Account describes the most recent advances in the DNA nanostructure directed assembly of biomolecular networks and explores the possibility of applying this technology to other fields of study. Recently, several reports have demonstrated the DNA nanostructure directed assembly of spatially interactive biomolecular networks. For example, researchers have constructed synthetic multienzyme cascades by

  12. Isolation and characterization of hyaluronic acid from marine organisms.

    PubMed

    Giji, Sadhasivam; Arumugam, Muthuvel

    2014-01-01

    Hyaluronic acid (HA) being a viscous slippery substance is a multifunctional glue with immense therapeutic applications such as ophthalmic surgery, orthopedic surgery and rheumatology, drug delivery systems, pulmonary pathology, joint pathologies, and tissue engineering. Although HA has been isolated from terrestrial origin (human umbilical cord, rooster comb, bacterial sources, etc.) so far, the increasing interest on this polysaccharide significantly aroused the alternative search from marine sources since it is at the preliminary level. Enthrallingly, marine environments are considered more biologically diverse than terrestrial environments. Although numerous methods have been described for the extraction and purification of HA, the hitch on the isolation methods which greatly influences the yield as well as the molecular weight of the polymer still exists. Adaptation of suitable method is essential in this venture. Stimulated by the developed technology, to sketch the steps involved in isolation and analytical techniques for characterization of this polymer, a brief report on the concerned approach has been reviewed.

  13. Growth and characterization of organic ferroelectric croconic acid thin films

    NASA Astrophysics Data System (ADS)

    Jiang, Xuanyuan; Lu, Haidong; Yin, Yuewei; Enders, Axel; Gruverman, Alexei; Xu, Xiaoshan

    Using vapor phase evaporation, we have studied the growth of the croconic acid (CCA) thin films, at various conditions such as temperature, thickness, growth speed, and substrates. The morphology of thin film was measured by atomic force microscopy (AFM); the ferroelectric property was confirmed by piezoresponse force microscopy (PFM). A critical thickness of 40 nm and optimal temperature of -30 celsius were found for continuous films, while the substrate and growth speed are found to play a minimal role. According to the reflection high energy electron diffraction (RHEED), the CCA films are polycrystalline. For a 40 nm continuous film, the roughness is about 3 nm, while the coercive voltage for the ferroelectric domain switching is approximately 7V. This is the first molecule ferroelectric thin film. The successful growth of continuous CCA films enhances the applications potential of CCA, which is a molecular crystal of ferroelectricity. Supported by NSF through UNL MRSEC (DMR-1420645).

  14. Microbial activity inhibition in chilled mackerel (Scomber scombrus) by employment of an organic acid-icing system.

    PubMed

    Sanjuás-Rey, Minia; Gallardo, José M; Barros-Velázquez, Jorge; Aubourg, Santiago P

    2012-05-01

    The present study concerns Atlantic mackerel (Scomber scombrus) traded as a chilled product. The study was aimed to investigate the effect of including a mixture of organic acids (citric, ascorbic, and lactic) in the icing medium employed during the fish chilled storage. To this end and according to preliminary trials results, an aqueous solution including 0.050% (w/v) of each acid was employed as icing medium; its effect on the microbial activity development in mackerel muscle was monitored for up to 13 d of chilled storage and compared to a counterpart-fish batch kept under traditional water ice considered as control. Results indicated a lower bacterial growth in mackerel muscle subjected to storage in the organic acid-icing system by comparison with control fish. Thus, statistically-significant (P < 0.05) differences between both batches for all 6 microbial groups investigated (aerobes, anaerobes, psychrotrophes, Enterobacteriaceae, lipolytics, and proteolytics) and for 2 chemical indices related to microbial activity development (total volatile bases and trimethylamine) were obtained. The surface wash caused by the melting of the ice during storage and the subsequent antimicrobial effect of such acids on skin microflora of the fish can be invoked as the main reasons for the limited bacterial growth found in the corresponding mackerel muscle.

  15. Acid Gas Capture Using CO2-Binding Organic Liquids

    SciTech Connect

    Heldebrant, David J.; Koech, Phillip K.; Rainbolt, James E.; Zheng, Feng

    2010-11-10

    Current chemical CO2 scrubbing technology is primarily aqueous alkanolamine based. These systems rapidly bind CO2 (forming water-soluble carbamate and bicarbonate salts) however, the process has serious disadvantages. The concentration of monoethanolamine rarely exceeds 30 wt % due to the corrosive nature of the solution, and this reduces the maximum CO2 volumetric (≤108 g/L) and gravimetric capacity (≤7 wt%) of the CO2 scrubber. The ≤30 wt % loading of ethanolamine also means that a large excess of water must be pumped and heated during CO2 capture and release, and this greatly increases the energy requirements especially considering the high specific heat of water (4 j/g-1K-1). Our approach is to switch to organic systems that chemically bind CO2 as liquid alkylcarbonate salts. Our CO2-binding organic liquids have higher CO2 solubility, lower specific heats, potential for less corrosion and lower binding energies for CO2 than aqueous systems. CO2BOLs also reversibly bind and release mixed sulfur oxides. Furthermore the CO2BOL system can be direct solvent replacements for any solvent based CO2 capture systems because they are commercially available reagents and because they are fluids they would not require extensive process re-engineering.

  16. Isotopic composition of Murchison organic compounds: Intramolecular carbon isotope fractionation of acetic acid. Simulation studies of cosmochemical organic syntheses

    NASA Technical Reports Server (NTRS)

    Yuen, G. U.; Cronin, J. R.; Blair, N. E.; Desmarais, D. J.; Chang, S.

    1991-01-01

    Recently, in our laboratories, samples of Murchison acetic acid were decarboxylated successfully and the carbon isotopic composition was measured for the methane released by this procedure. These analyses showed significant differences in C-13/C-12 ratios for the methyl and carboxyl carbons of the acetic acid molecule, strongly suggesting that more than one carbon source may be involved in the synthesis of the Murchison organic compounds. On the basis of this finding, laboratory model systems simulating cosmochemical synthesis are being studied, especially those processes capable of involving two or more starting carbon sources.

  17. The effect of several organic acids on phytate phosphorus hydrolysis in broiler chicks.

    PubMed

    Liem, A; Pesti, G M; Edwards, H M

    2008-04-01

    Supplementation of some organic acids to a P-deficient diet has been shown to improve phytate P utilization. Two experiments were conducted from 0 to 16 d in battery brooders to determine the effect of various organic acids supplementation on phytate P utilization. In both experiments, birds were fed P-deficient corn and soybean meal-based diets. In experiment 1, citric acid, malic acid, fumaric acid, and EDTA were supplemented. Experiment 2 had a 2 x 2 factorial design with 2 sources of Met, 2-hydroxy-4-(methylthio) butanoic acid (HMB) and dl-Met, with or without 500 U/kg of phytase. In experiment 1, the addition of citric, malic, and fumaric acids increased percentage of bone ash, but only the effect of citric acid was significant. The addition of citric and malic acids also significantly increased the retention of P and phytate P (P<0.05). In experiment 2, the addition of phytase to the diet significantly increased 16-d BW gain, feed intake, percentage of bone ash, milligrams of bone ash, phytate P disappearance, and decreased the incidence of P-deficiency rickets. Methionine source did not affect 16-d BW gain, feed intake, feed efficiency, milligrams of bone ash, or P rickets incidence. However, the birds fed HMB had a higher percentage of bone ash and phytate P disappearance compared with the groups fed dl-Met only when phytase was added to the diets. The additions of citric acid and HMB improved phytate P utilization. However, the reason why some organic acids are effective whereas others are not is not apparent.

  18. Joint effect of organic acids and inorganic salts on cloud droplet activation

    NASA Astrophysics Data System (ADS)

    Frosch, M.; Prisle, N. L.; Bilde, M.; Varga, Z.; Kiss, G.

    2010-07-01

    We have investigated CCN properties of internally mixed particles composed of one organic acid (oxalic acid, succinic acid, adipic acid, citric acid, cis-pinonic acid, or nordic reference fulvic acid) and one inorganic salt (sodium chloride or ammonium sulphate). Surface tension and water activity of aqueous model solutions with concentrations relevant for CCN activation were measured using a tensiometer and osmometry, respectively. The measurements were used to calculate Köhler curves, which were compared to measured critical supersaturations of particles with the same chemical compositions, determined with a cloud condensation nucleus counter. Surfactant surface partitioning was not accounted for. For the mixtures containing cis-pinonic acid or fulvic acid, a depression of surface tension was observed, but for the remaining mixtures the effect on surface tension was negligle at concentrations relevant for cloud droplet activation, and water activity was the more significant term in the Köhler equation. The surface tension depression of aqueous solutions containing both organic acid and inorganic salt was approximately the same as or smaller than that of aqueous solutions containing the same mass of the corresponding pure organic acids. Water activity was found to be highly dependent on the type and amount of inorganic salt. Sodium chloride was able to decrease water activity more than ammonium sulphate and both inorganic compounds had a higher effect on water activity than the studied organic acids, and increasing the mass ratio of the inorganic compound led to a decrease in water activity. Water activity measurements were compared to results from the E-AIM model and values estimated from both constant and variable van't Hoff factors to evaluate the performance of these approaches. The correspondence between measuments and estimates was overall good, except for highly concentrated solutions. Critical supersaturations calculated with Köhler theory based on

  19. Effects of organic acids on thermal inactivation of acid and cold stressed Enterococcus faecium.

    PubMed

    Fernández, Ana; Alvarez-Ordóñez, Avelino; López, Mercedes; Bernardo, Ana

    2009-08-01

    In this study the adaptative response to heat (70 degrees C) of Enterococcus faecium using fresh and refrigerated (at 4 degrees C for up to 1 month) stationary phase cells grown in Brain Heart Infusion (BHI) buffered at pH 7.4 (non-acid-adapted cells) and acidified BHI at pH values of 6.4 and 5.4 with acetic, ascorbic, citric, lactic, malic and hydrochloric acids (acid-adapted cells) was evaluated. In all cases, the survival curves obtained were concave upward. A mathematical model based on the Weibull distribution accurately described the inactivation kinetic. The results indicate that previous adaptation to a low pH increased the bacterial heat resistance, whereas the subsequent cold storage of cells reduced E. faecium thermal tolerance. Fresh acid-adapted cells showed t(2.5)-values (time needed to obtain an inactivation level of 2.5 log10 cycles) ranging from 2.57 to 9.51 min, while non-acid-adapted cells showed t(2.5)-values of 1.92 min. The extent of increased heat tolerance varied with the acid examined, resulting in the following order: citric > or = acetic > malic > or = lactic > hydrochloric > or = ascorbic. In contrast, cold storage progressively decreased E. faecium thermal resistance. The t(2.5) values found at the end of the period studied were about 2-3-fold lower than those corresponding to non-refrigerated cells, although this decrease was more marked (about 5-fold) when cells were grown in buffered BHI and BHI acidified at pH 5.4 with hydrochloric acid. These findings highlight the need for a better understanding of microbial response to various preservation stresses in order to increase the efficiency of thermal processes and to indicate the convenience of counterbalancing the benefits of the hurdle concept.

  20. Determination of sugars, organic acids, aroma components, and carotenoids in grapefruit pulps.

    PubMed

    Zheng, Huiwen; Zhang, Qiuyun; Quan, Junping; Zheng, Qiao; Xi, Wanpeng

    2016-08-15

    The composition and content of sugars, organic acids, volatiles and carotenoids, in the pulps of six grapefruit cultivars, were examined by HPLC and GC-MS. The results showed that sucrose was the dominant sugar in grapefruit, making up 40.08-59.68% of the total sugars, and the ratio of fructose to glucose was almost 1:1. Citric acid was the major organic acid and represented 39.10-63.55% of the total organic acids, followed by quininic acid. The ratios of individual sugars and organic acids play an important role in grapefruit taste determination. Monoterpenes and sesquiterpenes were the predominant volatiles in grapefruit, in particular d-limonene and caryophyllene. Caryophyllene, α-humulene, humulen-(v1), β-linalool and tert-butyl 2-methylpropanoate are the characteristic aroma compounds of grapefruit. Although β-carotene is the primary carotenoid in grapefruit, the pulp color is mainly determined by the ratios of zeaxanthin, β-cryptoxanthin and lycopene. Our results provide the first complete chemical characterization of the taste, aroma and color of grapefruit.