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Sample records for anaerobic syntrophic long-chain

  1. Thermosyntropha lipolytica gen. nov., sp. nov., a lipolytic, anaerobic, alkalitolerant, thermophilic bacterium utilizing short- and long-chain fatty acids in syntrophic coculture with a methanogenic archaeum

    SciTech Connect

    Svetlitshnyi, V.; Wiegel, J.; Rainey, F.

    1996-10-01

    Three strains of an anaerobic thermophilic organoheterotrophic lipolytic alkalitolerant bacterium, Thermosyntropha lipolytica gen. nov., sp. nov. (type strain JW/VS-264{sup T}; DSM 11003) were isolated from alkaline hot springs of Lake Bogoria (Kenya). The cells were nonmotile, non-spore forming, straight or slightly curved rods. At 60{degrees}C, the pH range for growth determined at 25{degrees}C [pH{sup 25{degrees}C}] was 7.15 to 9.5, with an optimum between 8.1 and 8.9 (pH{sup 60{degrees}C} of 7.6 and 8.1). At a pH{sup 25{degrees}C} of 8.5 temperature range for growth was from 52 to 70{degrees}C, with an optimum between 60 and 66{degrees}C. The shortest doubling time was around 1 h. In pure culture the bacterium grew in a mineral base medium supplemented with yeast extract, tryptone, Casamino Acids, betaine, and crotonate as carbon sources, producing acetate as a major product and constitutively a lipase. During growth in the presence of olive oil, free long-chain fatty acids were accumulated in the medium but the pure culture syntrophic coculture (Methanobacterium strain JW/VS-M29) the lipolytic bacteria grew on triacylglycerols and linear saturated and unsaturated fatty acids with 4 to 18 carbon atoms, but glycerol was not utilized. Fatty acids with even numbers of carbon atoms were degraded to acetate and methane, while from odd-numbered fatty acids 1 mol of propionate per mol of fatty acid was additionally formed. 16S rDNA sequence analysis identified Syntrophospora and Syntrophomonas spp. as closest phylogenetic neighbors.

  2. Enhancing syntrophic metabolism in up-flow anaerobic sludge blanket reactors with conductive carbon materials.

    PubMed

    Zhao, Zhiqiang; Zhang, Yaobin; Woodard, T L; Nevin, K P; Lovley, D R

    2015-09-01

    Syntrophic metabolism of alcohols and fatty acids is a critical step in anaerobic digestion, which if enhanced can better stabilize the process and enable shorter retention times. Direct interspecies electron transfer (DIET) has recently been recognized as an alternative route to hydrogen interspecies transfer as a mechanism for interspecies syntrophic electron exchange. Therefore, the possibility of accelerating syntrophic metabolism of ethanol in up-flow anaerobic sludge blanket (UASB) reactors by incorporating conductive materials in reactor design was investigated. Graphite, biochar, and carbon cloth all immediately enhanced methane production and COD removal. As the hydraulic retention time was decreased the increased effectiveness of treatment in reactors with conductive materials increased versus the control reactor. When these conductive materials were removed from the reactors rates of syntrophic metabolism declined to rates comparable to the control reactor. These results suggest that incorporating conductive materials in the design of UASB reactors may enhance digester effectiveness. PMID:25989089

  3. Microbial community adaptation influences long-chain fatty acid conversion during anaerobic codigestion of fats, oils, and grease with municipal sludge.

    PubMed

    Ziels, Ryan M; Karlsson, Anna; Beck, David A C; Ejlertsson, Jörgen; Yekta, Sepehr Shakeri; Bjorn, Annika; Stensel, H David; Svensson, Bo H

    2016-10-15

    Codigesting fats, oils, and greases with municipal wastewater sludge can greatly improve biomethane recovery at wastewater treatment facilities. Process loading rates of fats, oils, and greases have been previously tested with little knowledge of the digester microbial community structure, and high transient fat loadings have led to long chain fatty acid (LCFA) accumulation and digester upsets. This study utilized recently-developed quantitative PCR assays for syntrophic LCFA-degrading bacteria along with 16S amplicon sequencing to relate changes in microbial community structure to LCFA accumulation during transient loading increases to an anaerobic codigester receiving waste restaurant oil and municipal wastewater sludge. The 16S rRNA gene concentration of the syntrophic β-oxidizing genus Syntrophomonas increased to ∼15% of the Bacteria community in the codigester, but stayed below 3% in the control digester that was fed only wastewater sludge. Methanosaeta and Methanospirillum were the dominant methanogenic genera enriched in the codigester, and together comprised over 80% of the Archaea community by the end of the experimental period. Constrained ordination showed that changes in the codigester Bacteria and Archaea community structures were related to measures of digester performance. Notably, the effluent LCFA concentration in the codigester was positively correlated to the specific loading rate of waste oil normalized to the Syntrophomonas 16S rRNA concentration. Specific loading rates of 0-1.5 × 10(-12) g VS oil/16S gene copies-day resulted in LCFA concentrations below 30 mg/g TS, whereas LCFA accumulated up to 104 mg/g TS at higher transient loading rates. Based on the community-dependent loading limitations found, enhanced biomethane production from high loadings of fats, oils and greases can be achieved by promoting a higher biomass of slow-growing syntrophic consortia, such as with longer digester solids retention times. This work also

  4. Mechanism, Kinetics and Microbiology of Inhibition Caused by Long-Chain Fatty Acids in Anaerobic Digestion of Algal Biomass

    DOE PAGESBeta

    Ma, Jingwei; Zhao, Quan-Bao; Laurens, Lieve L.; Jarvis, Eric E.; Nagle, Nick J.; Chen, Shulin; Frear, Craig S.

    2015-09-15

    Oleaginous microalgae contain a high level of lipids, which can be extracted and converted to biofuel. The lipid-extracted residue can then be further utilized through anaerobic digestion to produce biogas. However, long-chain fatty acids (LCFAs) have been identified as the main inhibitory factor on microbial activity of anaerobic consortium. In this study, the mechanism of LCFA inhibition on anaerobic digestion of whole and lipid-extracted algal biomass was investigated with a range of calcium concentrations against various inoculum to substrate ratios as a means to alleviate the LCFA inhibition.

  5. Anaerobic hydrocarbon and fatty acid metabolism by syntrophic bacteria and their impact on carbon steel corrosion

    PubMed Central

    Lyles, Christopher N.; Le, Huynh M.; Beasley, William Howard; McInerney, Michael J.; Suflita, Joseph M.

    2014-01-01

    The microbial metabolism of hydrocarbons is increasingly associated with the corrosion of carbon steel in sulfate-rich marine waters. However, how such transformations influence metal biocorrosion in the absence of an electron acceptor is not fully recognized. We grew a marine alkane-utilizing, sulfate-reducing bacterium, Desulfoglaeba alkanexedens, with either sulfate or Methanospirillum hungatei as electron acceptors, and tested the ability of the cultures to catalyze metal corrosion. Axenically, D. alkanexedens had a higher instantaneous corrosion rate and produced more pits in carbon steel coupons than when the same organism was grown in syntrophic co-culture with the methanogen. Since anaerobic hydrocarbon biodegradation pathways converge on fatty acid intermediates, the corrosive ability of a known fatty acid-oxidizing syntrophic bacterium, Syntrophus aciditrophicus was compared when grown in pure culture or in co-culture with a H2-utilizing sulfate-reducing bacterium (Desulfovibrio sp., strain G11) or a methanogen (M. hungatei). The instantaneous corrosion rates in the cultures were not substantially different, but the syntrophic, sulfate-reducing co-culture produced more pits in coupons than other combinations of microorganisms. Lactate-grown cultures of strain G11 had higher instantaneous corrosion rates and coupon pitting compared to the same organism cultured with hydrogen as an electron donor. Thus, if sulfate is available as an electron acceptor, the same microbial assemblages produce sulfide and low molecular weight organic acids that exacerbated biocorrosion. Despite these trends, a surprisingly high degree of variation was encountered with the corrosion assessments. Differences in biomass, initial substrate concentration, rates of microbial activity or the degree of end product formation did not account for the variations. We are forced to ascribe such differences to the metallurgical properties of the coupons. PMID:24744752

  6. Anaerobic hydrocarbon and fatty acid metabolism by syntrophic bacteria and their impact on carbon steel corrosion.

    PubMed

    Lyles, Christopher N; Le, Huynh M; Beasley, William Howard; McInerney, Michael J; Suflita, Joseph M

    2014-01-01

    The microbial metabolism of hydrocarbons is increasingly associated with the corrosion of carbon steel in sulfate-rich marine waters. However, how such transformations influence metal biocorrosion in the absence of an electron acceptor is not fully recognized. We grew a marine alkane-utilizing, sulfate-reducing bacterium, Desulfoglaeba alkanexedens, with either sulfate or Methanospirillum hungatei as electron acceptors, and tested the ability of the cultures to catalyze metal corrosion. Axenically, D. alkanexedens had a higher instantaneous corrosion rate and produced more pits in carbon steel coupons than when the same organism was grown in syntrophic co-culture with the methanogen. Since anaerobic hydrocarbon biodegradation pathways converge on fatty acid intermediates, the corrosive ability of a known fatty acid-oxidizing syntrophic bacterium, Syntrophus aciditrophicus was compared when grown in pure culture or in co-culture with a H2-utilizing sulfate-reducing bacterium (Desulfovibrio sp., strain G11) or a methanogen (M. hungatei). The instantaneous corrosion rates in the cultures were not substantially different, but the syntrophic, sulfate-reducing co-culture produced more pits in coupons than other combinations of microorganisms. Lactate-grown cultures of strain G11 had higher instantaneous corrosion rates and coupon pitting compared to the same organism cultured with hydrogen as an electron donor. Thus, if sulfate is available as an electron acceptor, the same microbial assemblages produce sulfide and low molecular weight organic acids that exacerbated biocorrosion. Despite these trends, a surprisingly high degree of variation was encountered with the corrosion assessments. Differences in biomass, initial substrate concentration, rates of microbial activity or the degree of end product formation did not account for the variations. We are forced to ascribe such differences to the metallurgical properties of the coupons. PMID:24744752

  7. Control of interspecies electron flow during anaerobic digestion: role of floc formation in syntrophic methanogenesis

    SciTech Connect

    Thiele, J.H.; Chartrain, M.; Zeikus, J.G.

    1988-01-01

    The flora of an anaerobic whey-processing chemostat was separated by anaerobic sedimentation techniques into a free-living bacterial fraction and a bacterial floc fraction. The floc fraction constituted a major part (i.e., 57% total protein) of the total microbial population in the digestor, and it accounted for 87% of the total CO/sub 2/-dependent methanogenic activity and 76% of the total ethanol-consuming acetogenic activity. Lactose was degraded by both cellular fractions, but in the free flora fraction it was associated with higher intermediary levels of H/sub 2/, ethanol, butyrate, and propionate production. Electron microscopic analysis of flocs showed bacterial diversity and juxtapositioning of tentative Desulfovibrio and Methanobacterium species without significant microcolony formation. Ethanol, an intermediary product of lactose-hydrolyzing bacteria, was converted to acetate and methane within the flocs by interspecies electron transfer. Ethanol-dependent methane formation was compartmentalized and closely coupled kinetically within the flocs but without significant formation of H/sub 2/ gas. Physical disruption of flocs into fragments of 10- to 20-..mu..m diameter initially increased the H/sub 2/ partial pressure but did not change the carbon transformation kinetic patterns of ethanol metabolism or demonstrate a significant role for H/sub 2/ in CO/sub 2/ reduction to methane. The data demonstrate that floc formation in a whey-processing anaerobic digestor functions in juxtapositioning cells for interspecies electron transfer during syntrophic ethanol conversion into acetate and methane but by a mechanism which was independent of the available dissolved H/sub 2/ gas pool in the ecosystem.

  8. Diverse syntrophic relationships within a microbial community performing anaerobic oxidation of methane and sulfate reduction

    NASA Astrophysics Data System (ADS)

    Wang, F.; Chen, Y.; Zhang, Y.; He, Y.; Xiao, X.

    2012-12-01

    Here we report the metagenome and metatranscriptome analysis of a highly enriched, active AOM-SR (anaerobic oxidation of methane - sulfate reduction) community obtained through a continuous high-pressure bioreactor system. The community has a very high diversity of bacteria, besides SRB within delta-Proteobacteria, gamma-, beta-Proteobacteria and OP1 were found abundant. The archaeal components in the system are rather simple with only ANME2 and Marine Benthic Group D detected. FISH analysis revealed that most ANME cells form cell aggregates with SRB. A complete and functioning methanogenesis pathway from CO2 reduction was identified. Besides the methanogenesis and sulfate reducing pathways, pathways for complete denitrification and nitrogen fixation were also identified and expressed. Single cell aggregates in the community were captured and sequenced. Besides ANME and SRB, a third type of microorganisms were found present in certain cell aggregates, thus provide direct evidence for diverse syntrophic relationships among the microorganisms within the system fueled by AOM-SR.

  9. Anaerobic biodegradation of long-chain n-alkanes under sulfate-reducing conditions

    SciTech Connect

    Caldwell, M.E.; Suflita, J.M.; Garrett, R.M.; Prince, R.C.

    1998-07-15

    The ability of anaerobic microorganisms to degrade a wide variety of crude oil components was investigated using chronically hydrocarbon-contaminated marine sediments as the source of inoculum. When sulfate reduction was the predominant electron-accepting process, gas chromatographic analysis revealed almost complete n-alkane removal (C{sub 15}-C{sub 34}) from a weathered oil within 201 d of incubation. No alteration of the oil was detected in sterile control incubations or when nitrate served as an alternate electron acceptor. The amount of sulfate reduced in the oil-amended nonsterile incubations was more than enough to account for the complete mineralization of the n-alkane fraction of the oil; no loss of this anion was observed in sterile control incubations. The mineralization of the alkanes was confirmed using {sup 14}C-14,15-octacosane (C{sub 28}H{sub 58}), with 97% of the radioactivity recovered as {sup 14}CO{sub 2}. These findings extend the range of hydrocarbons known to be amenable to anaerobic biodegradation. Moreover, the rapid and extensive alteration in the n-alkanes can no longer be considered a defining characteristic of aerobic oil biodegradation processes alone.

  10. Influence of adsorption and anaerobic granular sludge characteristics on long chain fatty acids inhibition process.

    PubMed

    Palatsi, J; Affes, R; Fernandez, B; Pereira, M A; Alves, M M; Flotats, X

    2012-10-15

    The impact of LCFA adsorption on the methanogenic activity was evaluated in batch assays for two anaerobic granular sludges in the presence and absence of bentonite as synthetic adsorbent. A clear inhibitory effect at an oleate (C18:1) concentration of 0.5 g(C18:1) L(-1) was observed for both sludges. Palmitate (C16:0) was confirmed to be the main intermediate of C18:1 degradation in not adapted sludge and its accumulation was further evidenced by fluorescence staining and microscopy techniques. LCFA inhibition could be decreased by the addition of bentonite, reducing the lag-phase and accelerating the kinetics of LCFA degradation, concluding in the importance of the adsorptive nature of the LCFA inhibitory process. Granule morphology and molecular profiling of predominant microorganisms revealed that biomass adaptation to LCFA could modify the intermediates accumulation profiles and process rates. PMID:22841596

  11. Interspecies acetate transfer influences the extent of anaerobic benzoate degradation by syntrophic consortia

    SciTech Connect

    Warikoo, V.; McInerney, M.J.; Suflita, J.M.

    1997-03-01

    Benzoate degradation by an anaerobic, syntrophic bacterium, strain SB, in coculture with Desulfovibrio strain G-11 reached a threshold value which depended on the amount of acetate added, and ranged from about 2.5 to 29.9 {mu}M. Increasing acetate concentrations also uncompetitively inhibited benzoate degradation. The apparent V{sub max} and K{sub m} for benzoate degradation decreased with increasing acetate concentration, but the benzoate degradation capacity (V{sub max}/K{sub m}) of cell suspensions remained comparable. The addition of an acetate-using bacterium to cocultures after the threshold was reached resulted in the degradation of benzoate to below the detection limit. Mathematical simulations showed that the benzoate threshold was not predicted by the inhibitory effect of acetate on benzoate degradation kinetics. With nitrate instead of sulfate as the terminal electron acceptor, no benzoate threshold was observed in the presence of 20 mM acetate even though the degradation capacity was lower with nitrate than with sulfate. When strain SB was grown with a hydrogen-using partner that had a 5-fold lower hydrogen utilization capacity, a 5 to 9-fold lower the benzoate degradation capacity was observed compared to SB/G-11 cocultures. The Gibb`s free energy for benzoate degradation was less negative in cell suspensions with threshold compared to those without threshold. These studies showed that the threshold was not a function of the inhibition of benzoate degradation capacity by acetate, or the toxicity of the undissociated form of acetate. Rather a critical or minimal Gibb`s free energy may exist where thermodynamic constraints preclude further benzoate degradation.

  12. Growth of geobacter sulfurreducens with acetate in syntrophic cooperation with hydrogen-oxidizing anaerobic partners

    PubMed

    Cord-Ruwisch; Lovley; Schink

    1998-06-01

    Pure cultures of Geobacter sulfurreducens and other Fe(III)-reducing bacteria accumulated hydrogen to partial pressures of 5 to 70 Pa with acetate, butyrate, benzoate, ethanol, lactate, or glucose as the electron donor if electron release to an acceptor was limiting. G. sulfurreducens coupled acetate oxidation with electron transfer to an anaerobic partner bacterium in the absence of ferric iron or other electron acceptors. Cocultures of G. sulfurreducens and Wolinella succinogenes with nitrate as the electron acceptor degraded acetate efficiently and grew with doubling times of 6 to 8 h. The hydrogen partial pressures in these acetate-degrading cocultures were considerably lower, in the range of 0.02 to 0.04 Pa. From these values and the concentrations of the other reactants, it was calculated that in this cooperation the free energy change available to G. sulfurreducens should be about -53 kJ per mol of acetate oxidized, assuming complete conversion of acetate to CO2 and H2. However, growth yields (18.5 g of dry mass per mol of acetate for the coculture, about 14 g for G. sulfurreducens) indicated considerably higher energy gains. These yield data, measurement of hydrogen production rates, and calculation of the diffusive hydrogen flux indicated that electron transfer in these cocultures may not proceed exclusively via interspecies hydrogen transfer but may also proceed through an alternative carrier system with higher redox potential, e.g., a c-type cytochrome that was found to be excreted by G. sulfurreducens into the culture fluid. Syntrophic acetate degradation was also possible with G. sulfurreducens and Desulfovibrio desulfuricans CSN but only with nitrate as electron acceptor. These cultures produced cell yields of 4.5 g of dry mass per mol of acetate, to which both partners contributed at about equal rates. These results demonstrate that some Fe(III)-reducing bacteria can oxidize organic compounds under Fe(III) limitation with the production of hydrogen

  13. Enzymes involved in the anaerobic oxidation of n-alkanes: from methane to long-chain paraffins

    PubMed Central

    Callaghan, Amy V.

    2013-01-01

    Anaerobic microorganisms play key roles in the biogeochemical cycling of methane and non-methane alkanes. To date, there appear to be at least three proposed mechanisms of anaerobic methane oxidation (AOM). The first pathway is mediated by consortia of archaeal anaerobic methane oxidizers and sulfate-reducing bacteria (SRB) via “reverse methanogenesis” and is catalyzed by a homolog of methyl-coenzyme M reductase. The second pathway is also mediated by anaerobic methane oxidizers and SRB, wherein the archaeal members catalyze both methane oxidation and sulfate reduction and zero-valent sulfur is a key intermediate. The third AOM mechanism is a nitrite-dependent, “intra-aerobic” pathway described for the denitrifying bacterium, ‘Candidatus Methylomirabilis oxyfera.’ It is hypothesized that AOM proceeds via reduction of nitrite to nitric oxide, followed by the conversion of two nitric oxide molecules to dinitrogen and molecular oxygen. The latter can be used to functionalize the methane via a particulate methane monooxygenase. With respect to non-methane alkanes, there also appear to be novel mechanisms of activation. The most well-described pathway is the addition of non-methane alkanes across the double bond of fumarate to form alkyl-substituted succinates via the putative glycyl radical enzyme, alkylsuccinate synthase (also known as methylalkylsuccinate synthase). Other proposed mechanisms include anaerobic hydroxylation via ethylbenzene dehydrogenase-like enzymes and an “intra-aerobic” denitrification pathway similar to that described for ‘Methylomirabilis oxyfera.’ PMID:23717304

  14. ["Candidatus contubernalis alkalaceticum," an obligately syntrophic alkaliphilic bacterium capable of anaerobic acetate oxidation in a coculture with Desulfonatronum cooperativum].

    PubMed

    Zhilina, T N; Zavarzina, D G; Kolganova, T V; Turova, T P; Zavarzin, G A

    2005-01-01

    From the silty sediments of the Khadyn soda lake (Tuva), a binary sulfidogenic bacterial association capable of syntrophic acetate oxidation at pH 10.0 was isolated. An obligately syntrophic, gram-positive, spore-forming alkaliphilic rod-shaped bacterium performs acetate oxidation in a syntrophic association with a hydrogenotrophic, alkaliphilic sulfate-reducing bacterium; the latter organism was previously isolated and characterized as the new species Desulfonatronum cooperativum. Other sulfate-reducing bacteria of the genera Desulfonatronum and Desulfonatronovibrio can also act as the hydrogenotrophic partner. Apart from acetate, the syntrophic culture can oxidize ethanol, propanol, isopropanol, serine, fructose, and isobutyric acid. Selective amplification of 16S rRNA gene fragments of the acetate-utilizing syntrophic component of the binary culture was performed; it was found to cluster with clones of uncultured gram-positive bacteria within the family Syntrophomonadaceae. The acetate-oxidizing bacterium is thus the first representative of this cluster obtained in a laboratory culture. Based on its phylogenetic position, the new acetate-oxidizing syntrophic bacterium is proposed to be assigned, in a Candidate status, to a new genus and species: "Candidatus Contubernalis alkalaceticum." PMID:16400991

  15. Application of Anaerobic Digestion Model No. 1 to describe the syntrophic acetate oxidation of poultry litter in thermophilic anaerobic digestion.

    PubMed

    Rivera-Salvador, Víctor; López-Cruz, Irineo L; Espinosa-Solares, Teodoro; Aranda-Barradas, Juan S; Huber, David H; Sharma, Deepak; Toledo, J Ulises

    2014-09-01

    A molecular analysis found that poultry litter anaerobic digestion was dominated by hydrogenotrophic methanogens which suggests that bacterial acetate oxidation is the primary pathway in the thermophilic digestion of poultry litter. IWA Anaerobic Digestion Model No. 1 (ADM1) was modified to include the bacterial acetate oxidation process in the thermophilic anaerobic digestion (TAD). Two methods for ADM1 parameter estimation were applied: manual calibration with non-linear least squares (MC-NLLS) and an automatic calibration using differential evolution algorithms (DEA). In terms of kinetic parameters for acetate oxidizing bacteria, estimation by MC-NLLS and DEA were, respectively, km 1.12 and 3.25 ± 0.56 kg COD kg COD(-1)d(-1), KS 0.20 and 0.29 ± 0.018 kg COD m(-3) and Yac-st 0.14 and 0.10 ± 0.016 kg COD kg COD(-1). Experimental and predicted volatile fatty acids and biogas composition were in good agreement. Values of BIAS, MSE or INDEX demonstrate that both methods (MC-NLLS and DEA) increased ADM1 accuracy. PMID:25011081

  16. Anaerobic oxidation of long-chain n-alkanes by the hyperthermophilic sulfate-reducing archaeon, Archaeoglobus fulgidus

    PubMed Central

    Khelifi, Nadia; Amin Ali, Oulfat; Roche, Philippe; Grossi, Vincent; Brochier-Armanet, Céline; Valette, Odile; Ollivier, Bernard; Dolla, Alain; Hirschler-Réa, Agnès

    2014-01-01

    The thermophilic sulfate-reducing archaeon Archaeoglobus fulgidus strain VC-16 (DSM 4304), which is known to oxidize fatty acids and n-alkenes, was shown to oxidize saturated hydrocarbons (n-alkanes in the range C10–C21) with thiosulfate or sulfate as a terminal electron acceptor. The amount of n-hexadecane degradation observed was in stoichiometric agreement with the theoretically expected amount of thiosulfate reduction. One of the pathways used by anaerobic microorganisms to activate alkanes is addition to fumarate that involves alkylsuccinate synthase as a key enzyme. A search for genes encoding homologous enzymes in A. fulgidus identified the pflD gene (locus-tag AF1449) that was previously annotated as a pyruvate formate lyase. A phylogenetic analysis revealed that this gene is of bacterial origin and was likely acquired by A. fulgidus from a bacterial donor through a horizontal gene transfer. Based on three-dimensional modeling of the corresponding protein and molecular dynamic simulations, we hypothesize an alkylsuccinate synthase activity for this gene product. The pflD gene expression was upregulated during the growth of A. fulgidus on an n-alkane (C16) compared with growth on a fatty acid. Our results suggest that anaerobic alkane degradation in A. fulgidus may involve the gene pflD in alkane activation through addition to fumarate. These findings highlight the possible importance of hydrocarbon oxidation at high temperatures by A. fulgidus in hydrothermal vents and the deep biosphere. PMID:24763368

  17. Potential enhancement of direct interspecies electron transfer for syntrophic metabolism of propionate and butyrate with biochar in up-flow anaerobic sludge blanket reactors.

    PubMed

    Zhao, Zhiqiang; Zhang, Yaobin; Holmes, Dawn E; Dang, Yan; Woodard, Trevor L; Nevin, Kelly P; Lovley, Derek R

    2016-06-01

    Promoting direct interspecies electron transfer (DIET) to enhance syntrophic metabolism may be a strategy for accelerating the conversion of organic wastes to methane, but microorganisms capable of metabolizing propionate and butyrate via DIET under methanogenic conditions have yet to be identified. In an attempt to establish methanogenic communities metabolizing propionate or butyrate with DIET, enrichments were initiated with up-flow anaerobic sludge blanket (UASB), similar to those that were previously reported to support communities that metabolized ethanol with DIET that relied on direct biological electrical connections. In the absence of any amendments, microbial communities enriched were dominated by microorganisms closely related to pure cultures that are known to metabolize propionate or butyrate to acetate with production of H2. When biochar was added to the reactors there was a substantial enrichment on the biochar surface of 16S rRNA gene sequences closely related to Geobacter and Methanosaeta species known to participate in DIET. PMID:26967338

  18. Syntrophus aciditrophicus sp. nov., a new anaerobic bacterium that degrades fatty acids and benzoate in syntrophic association with hydrogen-using microorganisms

    NASA Technical Reports Server (NTRS)

    Jackson, B. E.; Bhupathiraju, V. K.; Tanner, R. S.; Woese, C. R.; McInerney, M. J.

    1999-01-01

    Strain SBT is a new, strictly anaerobic, gram-negative, nonmotile, non-sporeforming, rod-shaped bacterium that degrades benzoate and certain fatty acids in syntrophic association with hydrogen/formate-using microorganisms. Strain SBT produced approximately 3 mol of acetate and 0.6 mol of methane per mol of benzoate in coculture with Methanospirillum hungatei strain JF1. Saturated fatty acids, some unsaturated fatty acids, and methyl esters of butyrate and hexanoate also supported growth of strain SBT in coculture with Desulfovibrio strain G11. Strain SBT grew in pure culture with crotonate, producing acetate, butyrate, caproate, and hydrogen. The molar growth yield was 17 +/- 1 g cell dry mass per mol of crotonate. Strain SBT did not grow with fumarate, iron(III), polysulfide, or oxyanions of sulfur or nitrogen as electron acceptors with benzoate as the electron donor. The DNA base composition of strain SBT was 43.1 mol% G+C. Analysis of the 16 S rRNA gene sequence placed strain SBT in the delta-subdivision of the Proteobacteria, with sulfate-reducing bacteria. Strain SBT was most closely related to members of the genus Syntrophus. The clear phenotypic and genotypic differences between strain SBT and the two described species in the genus Syntrophus justify the formation of a new species, Syntrophus aciditrophicus.

  19. Syntrophic interactions and mechanisms underpinning anaerobic methane oxidation: targeted metaproteogenomics, single-cell protein detection and quantitative isotope imaging of microbial consortia

    SciTech Connect

    Orphan, Victoria Jeanne

    2014-11-26

    Syntrophy and mutualism play a central role in carbon and nutrient cycling by microorganisms. Yet, our ability to effectively study symbionts in culture has been hindered by the inherent interdependence of syntrophic associations, their dynamic behavior, and their frequent existence at thermodynamic limits. Now solutions to these challenges are emerging in the form of new methodologies. Developing strategies that establish links between the identity of microorganisms and their metabolic potential, as well as techniques that can probe metabolic networks on a scale that captures individual molecule exchange and processing, is at the forefront of microbial ecology. Understanding the interactions between microorganisms on this level, at a resolution previously intractable, will lead to our greater understanding of carbon turnover and microbial community resilience to environmental perturbations. In this project, we studied an enigmatic syntrophic association between uncultured methane-oxidizing archaea and sulfate-reducing bacteria. This environmental archaeal-bacterial partnership represents a globally important sink for methane in anoxic environments. The specific goals of this project were organized into 3 major tasks designed to address questions relating to the ecophysiology of these syntrophic organisms under changing environmental conditions (e.g. different electron acceptors and nutrients), primarily through the development of microanalytical imaging methods which enable the visualization of the spatial distribution of the partners within aggregates, consumption and exchange of isotopically labeled substrates, and expression of targeted proteins identified via metaproteomics. The advanced tool set developed here to collect, correlate, and analyze these high resolution image and isotope-based datasets from methane-oxidizing consortia has the potential to be widely applicable for studying and modeling patterns of activity and interactions across a broad range of

  20. The electron transfer system of syntrophically grown Desulfovibrio vulgaris

    SciTech Connect

    Walker, C.B.; He, Z.; Yang, Z.K.; Ringbauer, Jr., J.A.; He, Q.; Zhou, J.; Voordouw, G.; Wall, J.D.; Arkin, A.P.; Hazen, T.C.; Stolyar, S.; Stahl, D.A.

    2009-05-01

    Interspecies hydrogen transfer between organisms producing and consuming hydrogen promotes the decomposition of organic matter in most anoxic environments. Although syntrophic couplings between hydrogen producers and consumers are a major feature of the carbon cycle, mechanisms for energy recovery at the extremely low free energies of reactions typical of these anaerobic communities have not been established. In this study, comparative transcriptional analysis of a model sulfate-reducing microbe, Desulfovibrio vulgaris Hildenborough, suggested the use of alternative electron transfer systems dependent upon growth modality. During syntrophic growth on lactate with a hydrogenotrophic methanogen, D. vulgaris up-regulated numerous genes involved in electron transfer and energy generation when compared with sulfate-limited monocultures. In particular, genes coding for the putative membrane-bound Coo hydrogenase, two periplasmic hydrogenases (Hyd and Hyn) and the well-characterized high-molecular weight cytochrome (Hmc) were among the most highly expressed and up-regulated. Additionally, a predicted operon coding for genes involved in lactate transport and oxidation exhibited up-regulation, further suggesting an alternative pathway for electrons derived from lactate oxidation during syntrophic growth. Mutations in a subset of genes coding for Coo, Hmc, Hyd and Hyn impaired or severely limited syntrophic growth but had little affect on growth via sulfate-respiration. These results demonstrate that syntrophic growth and sulfate-respiration use largely independent energy generation pathways and imply that understanding of microbial processes sustaining nutrient cycling must consider lifestyles not captured in pure culture.

  1. The Electron Transfer System of Syntrophically Grown Desulfovibrio vulgaris

    SciTech Connect

    PBD; ENIGMA; GTL; VIMSS; Walker, Christopher B.; He, Zhili; Yang, Zamin K.; Ringbauer Jr., Joseph A.; He, Qiang; Zhou, Jizhong; Voordouw, Gerrit; Wall, Judy D.; Arkin, Adam P.; Hazen, Terry C.; Stolyar, Sergey; Stahl, David A.

    2009-06-22

    Interspecies hydrogen transfer between organisms producing and consuming hydrogen promotes the decomposition of organic matter in most anoxic environments. Although syntrophic couplings between hydrogen producers and consumers are a major feature of the carbon cycle, mechanisms for energy recovery at the extremely low free energies of reactions typical of these anaerobic communities have not been established. In this study, comparative transcriptional analysis of a model sulfate-reducing microbe, Desulfovibrio vulgaris Hildenborough, suggested the use of alternative electron transfer systems dependent upon growth modality. During syntrophic growth on lactate with a hydrogenotrophic methanogen, D. vulgaris up-regulated numerous genes involved in electron transfer and energy generation when compared with sulfate-limited monocultures. In particular, genes coding for the putative membrane-bound Coo hydrogenase, two periplasmic hydrogenases (Hyd and Hyn) and the well-characterized high-molecular weight cytochrome (Hmc) were among the most highly expressed and up-regulated. Additionally, a predicted operon coding for genes involved in lactate transport and oxidation exhibited up-regulation, further suggesting an alternative pathway for electrons derived from lactate oxidation during syntrophic growth. Mutations in a subset of genes coding for Coo, Hmc, Hyd and Hyn impaired or severely limited syntrophic growth but had little affect on growth via sulfate-respiration. These results demonstrate that syntrophic growth and sulfate-respiration use largely independent energy generation pathways and imply that understanding of microbial processes sustaining nutrient cycling must consider lifestyles not captured in pure culture.

  2. Energetics of syntrophic cooperation in methanogenic degradation.

    PubMed Central

    Schink, B

    1997-01-01

    Fatty acids and alcohols are key intermediates in the methanogenic degradation of organic matter, e.g., in anaerobic sewage sludge digestors or freshwater lake sediments. They are produced by classical fermenting bacteria for disposal of electrons derived in simultaneous substrate oxidations. Methanogenic bacteria can degrade primarily only one-carbon compounds. Therefore, acetate, propionate, ethanol, and their higher homologs have to be fermented further to one-carbon compounds. These fermentations are called secondary or syntrophic fermentations. They are endergonic processes under standard conditions and depend on intimate coupling with methanogenesis. The energetic situation of the prokaryotes cooperating in these processes is problematic: the free energy available in the reactions for total conversion of substrate to methane attributes to each partner amounts of energy in the range of the minimum biochemically convertible energy, i.e., 20 to 25 kJ per mol per reaction. This amount corresponds to one-third of an ATP unit and is equivalent to the energy required for a monovalent ion to cross the charged cytoplasmic membrane. Recent studies have revealed that syntrophically fermenting bacteria synthesize ATP by substrate-level phosphorylation and reinvest part of the ATP-bound energy into reversed electron transport processes, to release the electrons at a redox level accessible by the partner bacteria and to balance their energy budget. These findings allow us to understand the energy economy of these bacteria on the basis of concepts derived from the bioenergetics of other microorganisms. PMID:9184013

  3. Multiple Syntrophic Interactions in a Terephthalate-Degrading Methanogenic Consortium

    SciTech Connect

    Lykidis, Athanasios; Chen, Chia-Lung; Tringe, Susannah G.; McHardy, Alice C.; Copeland, Alex 5; Kyrpides, Nikos C.; Hugenholtz, Philip; Liu, Wen-Tso

    2010-08-05

    Terephthalate (TA) is one of the top 50 chemicals produced worldwide. Its production results in a TA-containing wastewater that is treated by anaerobic processes through a poorly understood methanogenic syntrophy. Using metagenomics, we characterized the methanogenic consortium tinside a hyper-mesophilic (i.e., between mesophilic and thermophilic), TA-degrading bioreactor. We identified genes belonging to dominant Pelotomaculum species presumably involved in TA degradation through decarboxylation, dearomatization, and modified ?-oxidation to H{sub 2}/CO{sub 2} and acetate. These intermediates are converted to CH{sub 4}/CO{sub 2} by three novel hyper-mesophilic methanogens. Additional secondary syntrophic interactions were predicted in Thermotogae, Syntrophus and candidate phyla OP5 and WWE1 populations. The OP5 encodes genes capable of anaerobic autotrophic butyrate production and Thermotogae, Syntrophus and WWE1 have the genetic potential to oxidize butyrate to COsub 2}/H{sub 2} and acetate. These observations suggest that the TA-degrading consortium consists of additional syntrophic interactions beyond the standard H{sub 2}-producing syntroph ? methanogen partnership that may serve to improve community stability.

  4. Methanogenic paraffin degradation proceeds via alkane addition to fumarate by 'Smithella' spp. mediated by a syntrophic coupling with hydrogenotrophic methanogens.

    PubMed

    Wawrik, Boris; Marks, Christopher R; Davidova, Irene A; McInerney, Michael J; Pruitt, Shane; Duncan, Kathleen E; Suflita, Joseph M; Callaghan, Amy V

    2016-09-01

    Anaerobic microbial biodegradation of recalcitrant, water-insoluble substrates, such as paraffins, presents unique metabolic challenges. To elucidate this process, a methanogenic consortium capable of mineralizing long-chain n-paraffins (C28 -C50 ) was enriched from San Diego Bay sediment. Analysis of 16S rRNA genes indicated the dominance of Syntrophobacterales (43%) and Methanomicrobiales (26%). Metagenomic sequencing allowed draft genome assembly of dominant uncultivated community members belonging to the bacterial genus Smithella and the archaeal genera Methanoculleus and Methanosaeta. Five contigs encoding homologs of the catalytic subunit of alkylsuccinate synthase (assA) were detected. Additionally, mRNA transcripts for these genes, including a homolog binned within the 'Smithella' sp. SDB genome scaffold, were detected via RT-PCR, implying that paraffins are activated via 'fumarate addition'. Metabolic reconstruction and comparison with genome scaffolds of uncultivated n-alkane degrading 'Smithella' spp. are consistent with the hypothesis that syntrophically growing 'Smithella' spp. may achieve reverse electron transfer by coupling the reoxidation of ETFred to a membrane-bound FeS oxidoreductase functioning as an ETF:menaquinone oxidoreductase. Subsequent electron transfer could proceed via a periplasmic formate dehydrogenase and/or hydrogenase, allowing energetic coupling to hydrogenotrophic methanogens such as Methanoculleus. Ultimately, these data provide fundamental insight into the energy conservation mechanisms that dictate interspecies interactions salient to methanogenic alkane mineralization. PMID:27198766

  5. Peat: home to novel syntrophic species that feed acetate- and hydrogen-scavenging methanogens.

    PubMed

    Schmidt, Oliver; Hink, Linda; Horn, Marcus A; Drake, Harold L

    2016-08-01

    Syntrophic bacteria drive the anaerobic degradation of certain fermentation products (e.g., butyrate, ethanol, propionate) to intermediary substrates (e.g., H2, formate, acetate) that yield methane at the ecosystem level. However, little is known about the in situ activities and identities of these syntrophs in peatlands, ecosystems that produce significant quantities of methane. The consumption of butyrate, ethanol or propionate by anoxic peat slurries at 5 and 15 °C yielded methane and CO2 as the sole accumulating products, indicating that the intermediates H2, formate and acetate were scavenged effectively by syntrophic methanogenic consortia. 16S rRNA stable isotope probing identified novel species/strains of Pelobacter and Syntrophomonas that syntrophically oxidized ethanol and butyrate, respectively. Propionate was syntrophically oxidized by novel species of Syntrophobacter and Smithella, genera that use different propionate-oxidizing pathways. Taxa not known for a syntrophic metabolism may have been involved in the oxidation of butyrate (Telmatospirillum-related) and propionate (unclassified Bacteroidetes and unclassified Fibrobacteres). Gibbs free energies (ΔGs) for syntrophic oxidations of ethanol and butyrate were more favorable than ΔGs for syntrophic oxidation of propionate. As a result of the thermodynamic constraints, acetate transiently accumulated in ethanol and butyrate treatments but not in propionate treatments. Aceticlastic methanogens (Methanosarcina, Methanosaeta) appeared to outnumber hydrogenotrophic methanogens (Methanocella, Methanoregula), reinforcing the likely importance of aceticlastic methanogenesis to the overall production of methane. ΔGs for acetogenesis from H2 to CO2 approximated to -20 kJ mol(-1) when acetate concentrations were low, indicating that acetogens may have contributed to the flow of carbon and reductant towards methane. PMID:26771931

  6. Draft Genome Sequence of the Syntrophic Lactate-Degrading Bacterium Tepidanaerobacter syntrophicus JLT

    PubMed Central

    Matsuura, Norihisa; Ohashi, Akiko; Tourlousse, Dieter M.

    2016-01-01

    We report here a high-quality draft genome sequence of the type strain (JL) of Tepidanaerobacter syntrophicus, an obligately anaerobic and moderately thermophilic bacterium, which is able to perform syntrophic lactate degradation with hydrogenotrophic methanogens. The genome comprises 2.43 Mb in 9 scaffolds, with a G+C content of 38.6%. PMID:26868399

  7. Community Structure in Methanogenic Enrichments Provides Insight into Syntrophic Interactions in Hydrocarbon-Impacted Environments

    PubMed Central

    Fowler, S. Jane; Toth, Courtney R. A.; Gieg, Lisa M.

    2016-01-01

    The methanogenic biodegradation of crude oil involves the conversion of hydrocarbons to methanogenic substrates by syntrophic bacteria and subsequent methane production by methanogens. Assessing the metabolic roles played by various microbial species in syntrophic communities remains a challenge, but such information has important implications for bioremediation and microbial enhanced energy recovery technologies. Many factors such as changing environmental conditions or substrate variations can influence the composition and biodegradation capabilities of syntrophic microbial communities in hydrocarbon-impacted environments. In this study, a methanogenic crude oil-degrading enrichment culture was successively transferred onto the single long chain fatty acids palmitate or stearate followed by their parent alkanes, hexadecane or octadecane, respectively, in order to assess the impact of different substrates on microbial community composition and retention of hydrocarbon biodegradation genes. 16S rRNA gene sequencing showed that a reduction in substrate diversity resulted in a corresponding loss of microbial diversity, but that hydrocarbon biodegradation genes (such as assA/masD encoding alkylsuccinate synthase) could be retained within a community even in the absence of hydrocarbon substrates. Despite substrate-related diversity changes, all communities were dominated by hydrogenotrophic and acetotrophic methanogens along with bacteria including Clostridium sp., members of the Deltaproteobacteria, and a number of other phyla. Microbial co-occurrence network analysis revealed a dense network of interactions amongst syntrophic bacteria and methanogens that were maintained despite changes in the substrates for methanogenesis. Our results reveal the effect of substrate diversity loss on microbial community diversity, indicate that many syntrophic interactions are stable over time despite changes in substrate pressure, and show that syntrophic interactions amongst

  8. Community Structure in Methanogenic Enrichments Provides Insight into Syntrophic Interactions in Hydrocarbon-Impacted Environments.

    PubMed

    Fowler, S Jane; Toth, Courtney R A; Gieg, Lisa M

    2016-01-01

    The methanogenic biodegradation of crude oil involves the conversion of hydrocarbons to methanogenic substrates by syntrophic bacteria and subsequent methane production by methanogens. Assessing the metabolic roles played by various microbial species in syntrophic communities remains a challenge, but such information has important implications for bioremediation and microbial enhanced energy recovery technologies. Many factors such as changing environmental conditions or substrate variations can influence the composition and biodegradation capabilities of syntrophic microbial communities in hydrocarbon-impacted environments. In this study, a methanogenic crude oil-degrading enrichment culture was successively transferred onto the single long chain fatty acids palmitate or stearate followed by their parent alkanes, hexadecane or octadecane, respectively, in order to assess the impact of different substrates on microbial community composition and retention of hydrocarbon biodegradation genes. 16S rRNA gene sequencing showed that a reduction in substrate diversity resulted in a corresponding loss of microbial diversity, but that hydrocarbon biodegradation genes (such as assA/masD encoding alkylsuccinate synthase) could be retained within a community even in the absence of hydrocarbon substrates. Despite substrate-related diversity changes, all communities were dominated by hydrogenotrophic and acetotrophic methanogens along with bacteria including Clostridium sp., members of the Deltaproteobacteria, and a number of other phyla. Microbial co-occurrence network analysis revealed a dense network of interactions amongst syntrophic bacteria and methanogens that were maintained despite changes in the substrates for methanogenesis. Our results reveal the effect of substrate diversity loss on microbial community diversity, indicate that many syntrophic interactions are stable over time despite changes in substrate pressure, and show that syntrophic interactions amongst

  9. Microbial community dynamics and stability during an ammonia-induced shift to syntrophic acetate oxidation.

    PubMed

    Werner, Jeffrey J; Garcia, Marcelo L; Perkins, Sarah D; Yarasheski, Kevin E; Smith, Samuel R; Muegge, Brian D; Stadermann, Frank J; DeRito, Christopher M; Floss, Christine; Madsen, Eugene L; Gordon, Jeffrey I; Angenent, Largus T

    2014-06-01

    Anaerobic digesters rely on the diversity and distribution of parallel metabolic pathways mediated by complex syntrophic microbial communities to maintain robust and optimal performance. Using mesophilic swine waste digesters, we experimented with increased ammonia loading to induce a shift from aceticlastic methanogenesis to an alternative acetate-consuming pathway of syntrophic acetate oxidation. In comparison with control digesters, we observed shifts in bacterial 16S rRNA gene content and in functional gene repertoires over the course of the digesters' 3-year operating period. During the first year, under identical startup conditions, all bioreactors mirrored each other closely in terms of bacterial phylotype content, phylogenetic structure, and evenness. When we perturbed the digesters by increasing the ammonia concentration or temperature, the distribution of bacterial phylotypes became more uneven, followed by a return to more even communities once syntrophic acetate oxidation had allowed the experimental bioreactors to regain stable operation. The emergence of syntrophic acetate oxidation coincided with a partial shift from aceticlastic to hydrogenotrophic methanogens. Our 16S rRNA gene analysis also revealed that acetate-fed enrichment experiments resulted in communities that did not represent the bioreactor community. Analysis of shotgun sequencing of community DNA suggests that syntrophic acetate oxidation was carried out by a heterogeneous community rather than by a specific keystone population with representatives of enriched cultures with this metabolic capacity. PMID:24657858

  10. Single-cell analysis reveals gene-expression heterogeneity in syntrophic dual-culture of Desulfovibrio vulgaris with Methanosarcina barkeri

    NASA Astrophysics Data System (ADS)

    Qi, Zhenhua; Pei, Guangsheng; Chen, Lei; Zhang, Weiwen

    2014-12-01

    Microbial syntrophic metabolism has been well accepted as the heart of how methanogenic and other anaerobic microbial communities function. In this work, we applied a single-cell RT-qPCR approach to reveal gene-expression heterogeneity in a model syntrophic system of Desulfovibrio vulgaris and Methanosarcina barkeri, as compared with the D. vulgaris monoculture. Using the optimized primers and single-cell analytical protocol, we quantitatively determine gene-expression levels of 6 selected target genes in each of the 120 single cells of D. vulgaris isolated from its monoculture and dual-culture with M. barkeri. The results demonstrated very significant cell-to-cell gene-expression heterogeneity for the selected D. vulgaris genes in both the monoculture and the syntrophic dual-culture. Interestingly, no obvious increase in gene-expression heterogeneity for the selected genes was observed for the syntrophic dual-culture when compared with its monoculture, although the community structure and cell-cell interactions have become more complicated in the syntrophic dual-culture. In addition, the single-cell RT-qPCR analysis also provided further evidence that the gene cluster (DVU0148-DVU0150) may be involved syntrophic metabolism between D. vulgaris and M. barkeri. Finally, the study validated that single-cell RT-qPCR analysis could be a valuable tool in deciphering gene functions and metabolism in mixed-cultured microbial communities.

  11. Long-chain polyacetals from plant oils.

    PubMed

    Chikkali, Samir; Stempfle, Florian; Mecking, Stefan

    2012-07-13

    Plant oil-derived α,ω-diacetals are polycondensated to the novel polyacetals [OCH(2) O(CH(2))(y)](n) (y = 19 and 23) with molecular weight of ca. M(n) = 2 × 10(4) g mol(-1). The long methylene sequences provide substantial melt and crystallization temperatures (T(m) = 88 °C and T(c) = 68 °C for y = 23), and rates of hydrolytic degradation are dramatically lower for the long-chain polyacetals versus a shorter chain analogue (y = 12) studied for comparison. PMID:22648983

  12. Thermodynamics and H2 Transfer in a Methanogenic, Syntrophic Community

    PubMed Central

    Hamilton, Joshua J.; Calixto Contreras, Montserrat; Reed, Jennifer L.

    2015-01-01

    Microorganisms in nature do not exist in isolation but rather interact with other species in their environment. Some microbes interact via syntrophic associations, in which the metabolic by-products of one species serve as nutrients for another. These associations sustain a variety of natural communities, including those involved in methanogenesis. In anaerobic syntrophic communities, energy is transferred from one species to another, either through direct contact and exchange of electrons, or through small molecule diffusion. Thermodynamics plays an important role in governing these interactions, as the oxidation reactions carried out by the first community member are only possible because degradation products are consumed by the second community member. This work presents the development and analysis of genome-scale network reconstructions of the bacterium Syntrophobacter fumaroxidans and the methanogenic archaeon Methanospirillum hungatei. The models were used to verify proposed mechanisms of ATP production within each species. We then identified additional constraints and the cellular objective function required to match experimental observations. The thermodynamic S. fumaroxidans model could not explain why S. fumaroxidans does not produce H2 in monoculture, indicating that current methods might not adequately estimate the thermodynamics, or that other cellular processes (e.g., regulation) play a role. We also developed a thermodynamic coculture model of the association between the organisms. The coculture model correctly predicted the exchange of both H2 and formate between the two species and suggested conditions under which H2 and formate produced by S. fumaroxidans would be fully consumed by M. hungatei. PMID:26147299

  13. Magnetite particles triggering a faster and more robust syntrophic pathway of methanogenic propionate degradation.

    PubMed

    Cruz Viggi, Carolina; Rossetti, Simona; Fazi, Stefano; Paiano, Paola; Majone, Mauro; Aulenta, Federico

    2014-07-01

    Interspecies electron transfer mechanisms between Bacteria and Archaea play a pivotal role during methanogenic degradation of organic matter in natural and engineered anaerobic ecosystems. Growing evidence suggests that in syntrophic communities electron transfer does not rely exclusively on the exchange of diffusible molecules and energy carriers such as hydrogen or formate, rather microorganisms have the capability to exchange metabolic electrons in a more direct manner. Here, we show that supplementation of micrometer-size magnetite (Fe3O4) particles to a methanogenic sludge enhanced (up to 33%) the methane production rate from propionate, a key intermediate in the anaerobic digestion of organic matter and a model substrate to study energy-limited syntrophic communities. The stimulatory effect most probably resulted from the establishment of a direct interspecies electron transfer (DIET), based on magnetite particles serving as electron conduits between propionate-oxidizing acetogens and carbon dioxide-reducing methanogens. Theoretical calculations revealed that DIET allows electrons to be transferred among syntrophic partners at rates which are substantially higher than those attainable via interspecies H2 transfer. Besides the remarkable potential for improving anaerobic digestion, which is a proven biological strategy for renewable energy production, the herein described conduction-based DIET could also have a role in natural methane emissions from magnetite-rich soils and sediments. PMID:24901501

  14. The Genome of Syntrophomonas Wolfei: New Insights into Syntrophic Metabolism and Biohydrogen Production

    SciTech Connect

    Sieber, Jessica R; Sims, David R; Han, Cliff F; Kim, E; Lykidis, Athanasios; Lapidus, Alla; McDonald, Erin; Rohlin, Lars; Culley, David E; Gunsalus, Robert; McInerney, Michael J

    2010-08-01

    Syntrophomonas wolfei is a specialist, evolutionarily adapted for syntrophic growth with methanogens and other hydrogen- and/or formate-using microorganisms. This slow growing anaerobe has three putative ribosome RNA operons, each of which has 16S rRNA and 23S rRNA genes of different length and multiple 5S rRNA genes. The genome also contains ten RNA-directed, DNA polymerase genes. Genomic analysis shows that S. wolfei relies solely on the reduction of protons, bicarbonate, or unsaturated fatty acids to re-oxidize reduced cofactors. S. wolfei lacks the genes needed for aerobic or anaerobic respiration and has an exceptionally limited ability to create ion gradients. An ATP synthase and a pyrophosphatase were the only systems detected capable of creating an ion gradient. Multiple homologs for β-oxidation genes were present even though S. wolfei uses a limited range of fatty acids from 4 to 8 carbons in length. S. wolfei, other syntrophic metabolizers with completed genomic sequences, and thermophilic anaerobes known to produce high molar ratios of hydrogen from glucose have genes to produce H2 from NADH by an electron bifurcation mechanism. Comparative genomic analysis also suggests that formate production from NADH may involve electron bifurcation. A membrane-bound, iron-sulfur oxidoreductase found in S. wolfei and Syntrophus aciditrophicus may be uniquely involved in reverse electron transport during syntrophic fatty acid metabolism. The genome sequence of S. wolfei reveals several core reactions that may be characteristic of syntrophic fatty acid metabolism and illustrates how biological systems produce hydrogen from thermodynamically difficult reactions.

  15. Response of a Rice Paddy Soil Methanogen to Syntrophic Growth as Revealed by Transcriptional Analyses

    PubMed Central

    Liu, Pengfei; Yang, Yanxiang; Lü, Zhe

    2014-01-01

    Members of Methanocellales are widespread in paddy field soils and play the key role in methane production. These methanogens feature largely in these organisms' adaptation to low H2 and syntrophic growth with anaerobic fatty acid oxidizers. The adaptive mechanisms, however, remain unknown. In the present study, we determined the transcripts of 21 genes involved in the key steps of methanogenesis and acetate assimilation of Methanocella conradii HZ254, a strain recently isolated from paddy field soil. M. conradii was grown in monoculture and syntrophically with Pelotomaculum thermopropionicum (a propionate syntroph) or Syntrophothermus lipocalidus (a butyrate syntroph). Comparison of the relative transcript abundances showed that three hydrogenase-encoding genes and all methanogenesis-related genes tested were upregulated in cocultures relative to monoculture. The genes encoding formylmethanofuran dehydrogenase (Fwd), heterodisulfide reductase (Hdr), and the membrane-bound energy-converting hydrogenase (Ech) were the most upregulated among the evaluated genes. The expression of the formate dehydrogenase (Fdh)-encoding gene also was significantly upregulated. In contrast, an acetate assimilation gene was downregulated in cocultures. The genes coding for Fwd, Hdr, and the D subunit of F420-nonreducing hydrogenase (Mvh) form a large predicted transcription unit; therefore, the Mvh/Hdr/Fwd complex, capable of mediating the electron bifurcation and connecting the first and last steps of methanogenesis, was predicted to be formed in M. conradii. We propose that Methanocella methanogens cope with low H2 and syntrophic growth by (i) stabilizing the Mvh/Hdr/Fwd complex and (ii) activating formate-dependent methanogenesis. PMID:24837392

  16. Direct interspecies electron transfer accelerates syntrophic oxidation of butyrate in paddy soil enrichments.

    PubMed

    Li, Huijuan; Chang, Jiali; Liu, Pengfei; Fu, Li; Ding, Dewen; Lu, Yahai

    2015-05-01

    Syntrophic interaction occurs during anaerobic fermentation of organic substances forming methane as the final product. H2 and formate are known to serve as the electron carriers in this process. Recently, it has been shown that direct interspecies electron transfer (DIET) occurs for syntrophic CH4 production from ethanol and acetate. Here, we constructed paddy soil enrichments to determine the involvement of DIET in syntrophic butyrate oxidation and CH4 production. The results showed that CH4 production was significantly accelerated in the presence of nanoFe3 O4 in all continuous transfers. This acceleration increased with the increase of nanoFe3 O4 concentration but was dismissed when Fe3 O4 was coated with silica that insulated the mineral from electrical conduction. NanoFe3 O4 particles were found closely attached to the cell surfaces of different morphology, thus bridging cell connections. Molecular approaches, including DNA-based stable isotope probing, revealed that the bacterial Syntrophomonadaceae and Geobacteraceae, and the archaeal Methanosarcinaceae, Methanocellales and Methanobacteriales, were involved in the syntrophic butyrate oxidation and CH4 production. Among them, the growth of Geobacteraceae strictly relied on the presence of nanoFe3 O4 and its electrical conductivity in particular. Other organisms, except Methanobacteriales, were present in enrichments regardless of nanoFe3 O4 amendment. Collectively, our study demonstrated that the nanoFe3 O4 -facilitated DIET occurred in syntrophic CH4 production from butyrate, and Geobacter species played the key role in this process in the paddy soil enrichments. PMID:25059331

  17. Comparative Genomics of Syntrophic Branched-Chain Fatty Acid Degrading Bacteria

    PubMed Central

    Narihiro, Takashi; Nobu, Masaru K.; Tamaki, Hideyuki; Kamagata, Yoichi; Sekiguchi, Yuji; Liu, Wen-Tso

    2016-01-01

    The syntrophic degradation of branched-chain fatty acids (BCFAs) such as 2-methylbutyrate and isobutyrate is an essential step in the production of methane from proteins/amino acids in anaerobic ecosystems. While a few syntrophic BCFA-degrading bacteria have been isolated, their metabolic pathways in BCFA and short-chain fatty acid (SCFA) degradation as well as energy conservation systems remain unclear. In an attempt to identify these pathways, we herein performed comparative genomics of three syntrophic bacteria: 2-methylbutyrate-degrading “Syntrophomonas wolfei subsp. methylbutyratica” strain JCM 14075T (=4J5T), isobutyrate-degrading Syntrophothermus lipocalidus strain TGB-C1T, and non-BCFA-metabolizing S. wolfei subsp. wolfei strain GöttingenT. We demonstrated that 4J5 and TGB-C1 both encode multiple genes/gene clusters involved in β-oxidation, as observed in the Göttingen genome, which has multiple copies of genes associated with butyrate degradation. The 4J5 genome possesses phylogenetically distinct β-oxidation genes, which may be involved in 2-methylbutyrate degradation. In addition, these Syntrophomonadaceae strains harbor various hydrogen/formate generation systems (i.e., electron-bifurcating hydrogenase, formate dehydrogenase, and membrane-bound hydrogenase) and energy-conserving electron transport systems, including electron transfer flavoprotein (ETF)-linked acyl-CoA dehydrogenase, ETF-linked iron-sulfur binding reductase, ETF dehydrogenase (FixABCX), and flavin oxidoreductase-heterodisulfide reductase (Flox-Hdr). Unexpectedly, the TGB-C1 genome encodes a nitrogenase complex, which may function as an alternative H2 generation mechanism. These results suggest that the BCFA-degrading syntrophic strains 4J5 and TGB-C1 possess specific β-oxidation-related enzymes for BCFA oxidation as well as appropriate energy conservation systems to perform thermodynamically unfavorable syntrophic metabolism. PMID:27431485

  18. Ammonia effect on hydrogenotrophic methanogens and syntrophic acetate-oxidizing bacteria.

    PubMed

    Wang, Han; Fotidis, Ioannis A; Angelidaki, Irini

    2015-11-01

    Ammonia-rich substrates can cause inhibition on anaerobic digestion process. Syntrophic acetate-oxidizing bacteria (SAOB) and hydrogenotrophic methanogens are important for the ammonia inhibitory mechanism on anaerobic digestion. The roles and interactions of SAOB and hydrogenotrophic methanogens to ammonia inhibition effect are still unclear. The aim of the current study was to determine the ammonia toxicity levels of various pure strains of SAOB and hydrogenotrophic methanogens. Moreover, ammonia toxicity on the syntrophic-cultivated strains of SAOB and hydrogenotrophic methanogens was tested. Thus, four hydrogenotrophic methanogens (i.e. Methanoculleus bourgensis, Methanobacterium congolense, Methanoculleu thermophilus and Methanothermobacter thermautotrophicus), two SAOB (i.e. Tepidanaerobacter acetatoxydans and Thermacetogenium phaeum) and their syntrophic cultivation were assessed under 0.26, 3, 5 and 7 g NH4 (+)-N L(-1). The results showed that some hydrogenotrophic methanogens were equally, or in some cases, more tolerant to high ammonia levels compared to SAOB. Furthermore, a mesophilic hydrogenotrophic methanogen was more sensitive to ammonia toxicity compared to thermophilic methanogens tested in the study, which is contradicting to the general belief that thermophilic methanogens are more vulnerable to high ammonia loads compared to mesophilic. This unexpected finding underlines the fact that the complete knowledge of ammonia inhibition effect on hydrogenotrophic methanogens is still absent. PMID:26490748

  19. Conductive iron oxide minerals accelerate syntrophic cooperation in methanogenic benzoate degradation.

    PubMed

    Zhuang, Li; Tang, Jia; Wang, Yueqiang; Hu, Min; Zhou, Shungui

    2015-08-15

    Recent studies have suggested that conductive iron oxide minerals can facilitate syntrophic metabolism of the methanogenic degradation of organic matter, such as ethanol, propionate and butyrate, in natural and engineered microbial ecosystems. This enhanced syntrophy involves direct interspecies electron transfer (DIET) powered by microorganisms exchanging metabolic electrons through electrically conductive minerals. Here, we evaluated the possibility that conductive iron oxides (hematite and magnetite) can stimulate the methanogenic degradation of benzoate, which is a common intermediate in the anaerobic metabolism of aromatic compounds. The results showed that 89-94% of the electrons released from benzoate oxidation were recovered in CH4 production, and acetate was identified as the only carbon-bearing intermediate during benzoate degradation. Compared with the iron-free controls, the rates of methanogenic benzoate degradation were enhanced by 25% and 53% in the presence of hematite and magnetite, respectively. This stimulatory effect probably resulted from DIET-mediated methanogenesis in which electrons transfer between syntrophic partners via conductive iron minerals. Phylogenetic analyses revealed that Bacillaceae, Peptococcaceae, and Methanobacterium are potentially involved in the functioning of syntrophic DIET. Considering the ubiquitous presence of iron minerals within soils and sediments, the findings of this study will increase the current understanding of the natural biological attenuation of aromatic hydrocarbons in anaerobic environments. PMID:25827267

  20. Mean field theory for long chain molecules

    NASA Astrophysics Data System (ADS)

    Pereira, Gerald G.

    1996-06-01

    We provide a mathematical formalism for a self-consistent mean field treatment of long chain molecules. The formalism is applied to the case of a neutral polymer under the excluded volume interaction. Upon scaling the problem in the N→∞ limit we find the natural scaling length RN, of the polymer, which is made up of (N+1) monomers or beads, is RN˜N3/5, the well known Flory result. The asymptotics of the problem is dominated by the neighborhood of the turning point, so that a uniformly valid Green's function solution of the differential equations is necessary. In the neighborhood of a point y* the scaled polymer density fN(x), is found to decay sharply. If we let x denote the scaled distance from one end of the chain to a point in space we obtain, for y*-x≳O(N-2/15), a closed form expression for the polymer density viz., fN(x)˜{1/2x2[fN(x)-fN(y*)]1/2} while for x-y*≳O(N-2/15) the density is shown to be, to leading order, zero. Although our results imply the rate of decay of the density at y* is O(N1/5) we are unable to verify this explicitly by calculating fN'(y*). We believe this is due to the inability of the WKB theory to correctly approximate solutions in regions of rapid variation. We suggest remedies for this, so that a complete self-consistent solution may be obtained.

  1. Bacterial Long-Chain Polyunsaturated Fatty Acids: Their Biosynthetic Genes, Functions, and Practical Use.

    PubMed

    Yoshida, Kiyohito; Hashimoto, Mikako; Hori, Ryuji; Adachi, Takumi; Okuyama, Hidetoshi; Orikasa, Yoshitake; Nagamine, Tadashi; Shimizu, Satoru; Ueno, Akio; Morita, Naoki

    2016-01-01

    The nutritional and pharmaceutical values of long-chain polyunsaturated fatty acids (LC-PUFAs) such as arachidonic, eicosapentaenoic and docosahexaenoic acids have been well recognized. These LC-PUFAs are physiologically important compounds in bacteria and eukaryotes. Although little is known about the biosynthetic mechanisms and functions of LC-PUFAs in bacteria compared to those in higher organisms, a combination of genetic, bioinformatic, and molecular biological approaches to LC-PUFA-producing bacteria and some eukaryotes have revealed the notably diverse organization of the pfa genes encoding a polyunsaturated fatty acid synthase complex (PUFA synthase), the LC-PUFA biosynthetic processes, and tertiary structures of the domains of this enzyme. In bacteria, LC-PUFAs appear to take part in specific functions facilitating individual membrane proteins rather than in the adjustment of the physical fluidity of the whole cell membrane. Very long chain polyunsaturated hydrocarbons (LC-HCs) such as hentriacontanonaene are considered to be closely related to LC-PUFAs in their biosynthesis and function. The possible role of LC-HCs in strictly anaerobic bacteria under aerobic and anaerobic environments and the evolutionary relationships of anaerobic and aerobic bacteria carrying pfa-like genes are also discussed. PMID:27187420

  2. Bacterial Long-Chain Polyunsaturated Fatty Acids: Their Biosynthetic Genes, Functions, and Practical Use

    PubMed Central

    Yoshida, Kiyohito; Hashimoto, Mikako; Hori, Ryuji; Adachi, Takumi; Okuyama, Hidetoshi; Orikasa, Yoshitake; Nagamine, Tadashi; Shimizu, Satoru; Ueno, Akio; Morita, Naoki

    2016-01-01

    The nutritional and pharmaceutical values of long-chain polyunsaturated fatty acids (LC-PUFAs) such as arachidonic, eicosapentaenoic and docosahexaenoic acids have been well recognized. These LC-PUFAs are physiologically important compounds in bacteria and eukaryotes. Although little is known about the biosynthetic mechanisms and functions of LC-PUFAs in bacteria compared to those in higher organisms, a combination of genetic, bioinformatic, and molecular biological approaches to LC-PUFA-producing bacteria and some eukaryotes have revealed the notably diverse organization of the pfa genes encoding a polyunsaturated fatty acid synthase complex (PUFA synthase), the LC-PUFA biosynthetic processes, and tertiary structures of the domains of this enzyme. In bacteria, LC-PUFAs appear to take part in specific functions facilitating individual membrane proteins rather than in the adjustment of the physical fluidity of the whole cell membrane. Very long chain polyunsaturated hydrocarbons (LC-HCs) such as hentriacontanonaene are considered to be closely related to LC-PUFAs in their biosynthesis and function. The possible role of LC-HCs in strictly anaerobic bacteria under aerobic and anaerobic environments and the evolutionary relationships of anaerobic and aerobic bacteria carrying pfa-like genes are also discussed. PMID:27187420

  3. Inhibition of Methanogenesis from Acetate in Granular Sludge by Long-Chain Fatty Acids

    PubMed Central

    Koster, Iman W.; Cramer, Albertus

    1987-01-01

    The effect of four saturated long-chain fatty acids (caprylic, capric, lauric, and myristic) and one unsaturated long-chain fatty acid (oleic) on the microbial formation of methane from acetate was investigated in batch anaerobic toxicity assays. The tests were carried out with granular sludge from an upflow anaerobic sludge bed reactor. In this sludge, Methanothrix spp. are the predominant acetoclastic methanogens. Lauric acid appeared to be the most versatile inhibitor: inhibition started at 1.6 mM, and at 4.3 mM the maximum specific acetoclastic methanogenic activity had been reduced to 50%. Caprylic acid appeared to be only slightly inhibitory. Oleic acid was almost as inhibitory as lauric acid. Although adsorption of the inhibitor on the cell wall might play an important role in the mechanism of inhibition, the inhibition was found to be correlated with concentration rather than with the amount per unit of biomass. In practical situations, as in anaerobic waste treatment processes, synergism can be expected to enhance the inhibition of methanogenesis. In the present research a background concentration of lauric acid below its MIC strongly enhanced the toxicity of capric acid and (to an even greater extent) myristic acid. PMID:16347288

  4. Dynamic functional characterization and phylogenetic changes due to Long Chain Fatty Acids pulses in biogas reactors

    PubMed Central

    Kougias, Panagiotis G.; Treu, Laura; Campanaro, Stefano; Zhu, Xinyu; Angelidaki, Irini

    2016-01-01

    The process stability of biogas plants is often deteriorated by the accumulation of Long Chain Fatty Acids (LCFA). The microbial community shifts due to LCFA disturbances have been poorly understood as the molecular techniques used were not able to identify the genome characteristics of uncultured microorganisms, and additionally, the presence of limited number of reference genomes in public databases prevented the comprehension of specific functional roles characterizing these microorganisms. The present study is the first research which deciphers by means of high throughput shotgun sequencing the dynamics of the microbial community during an inhibitory shock load induced by single pulses of unsaturated LCFA at two different concentrations (i.e. 2 g/L-reactor and 3 g/L-reactor). The metagenomic analysis showed that only the microbes associated with LCFA degradation could encode proteins related to “chemotaxis” and “flagellar assembly”, which promoted the ability to move towards the LCFA sources so as to degrade them. Moreover, the syntrophic interactions found between Syntrophomonas sp. together with Methanosarcina sp. were possibly assigned to the menaquinone-electron transfer. Finally, it was proven that a previously exposed to LCFA inoculum is more efficient in the degradation process of LCFA due to the specialization of the microbial consortium. PMID:27353502

  5. Dynamic functional characterization and phylogenetic changes due to Long Chain Fatty Acids pulses in biogas reactors.

    PubMed

    Kougias, Panagiotis G; Treu, Laura; Campanaro, Stefano; Zhu, Xinyu; Angelidaki, Irini

    2016-01-01

    The process stability of biogas plants is often deteriorated by the accumulation of Long Chain Fatty Acids (LCFA). The microbial community shifts due to LCFA disturbances have been poorly understood as the molecular techniques used were not able to identify the genome characteristics of uncultured microorganisms, and additionally, the presence of limited number of reference genomes in public databases prevented the comprehension of specific functional roles characterizing these microorganisms. The present study is the first research which deciphers by means of high throughput shotgun sequencing the dynamics of the microbial community during an inhibitory shock load induced by single pulses of unsaturated LCFA at two different concentrations (i.e. 2 g/L-reactor and 3 g/L-reactor). The metagenomic analysis showed that only the microbes associated with LCFA degradation could encode proteins related to "chemotaxis" and "flagellar assembly", which promoted the ability to move towards the LCFA sources so as to degrade them. Moreover, the syntrophic interactions found between Syntrophomonas sp. together with Methanosarcina sp. were possibly assigned to the menaquinone-electron transfer. Finally, it was proven that a previously exposed to LCFA inoculum is more efficient in the degradation process of LCFA due to the specialization of the microbial consortium. PMID:27353502

  6. Conductive Fe3O4 Nanoparticles Accelerate Syntrophic Methane Production from Butyrate Oxidation in Two Different Lake Sediments

    PubMed Central

    Zhang, Jianchao; Lu, Yahai

    2016-01-01

    Syntrophic methanogenesis is an essential link in the global carbon cycle and a key bioprocess for the disposal of organic waste and production of biogas. Recent studies suggest direct interspecies electron transfer (DIET) is involved in electron exchange in methanogenesis occurring in paddy soils, anaerobic digesters, and specific co-cultures with Geobacter. In this study, we evaluate the possible involvement of DIET in the syntrophic oxidation of butyrate in the enrichments from two lake sediments (an urban lake and a natural lake). The results showed that the production of CH4 was significantly accelerated in the presence of conductive nanoscale Fe3O4 or carbon nanotubes in the sediment enrichments. Observations made with fluorescence in situ hybridization and scanning electron microscope indicated that microbial aggregates were formed in the enrichments. It appeared that the average cell-to-cell distance in aggregates in nanomaterial-amended enrichments was larger than that in aggregates in the non-amended control. These results suggested that DIET-mediated syntrophic methanogenesis could occur in the lake sediments in the presence of conductive materials. Microbial community analysis of the enrichments revealed that the genera of Syntrophomonas, Sulfurospirillum, Methanosarcina, and Methanoregula were responsible for syntrophic oxidation of butyrate in lake sediment samples. The mechanism for the conductive-material-facilitated DIET in butyrate syntrophy deserves further investigation. PMID:27597850

  7. Conductive Fe3O4 Nanoparticles Accelerate Syntrophic Methane Production from Butyrate Oxidation in Two Different Lake Sediments.

    PubMed

    Zhang, Jianchao; Lu, Yahai

    2016-01-01

    Syntrophic methanogenesis is an essential link in the global carbon cycle and a key bioprocess for the disposal of organic waste and production of biogas. Recent studies suggest direct interspecies electron transfer (DIET) is involved in electron exchange in methanogenesis occurring in paddy soils, anaerobic digesters, and specific co-cultures with Geobacter. In this study, we evaluate the possible involvement of DIET in the syntrophic oxidation of butyrate in the enrichments from two lake sediments (an urban lake and a natural lake). The results showed that the production of CH4 was significantly accelerated in the presence of conductive nanoscale Fe3O4 or carbon nanotubes in the sediment enrichments. Observations made with fluorescence in situ hybridization and scanning electron microscope indicated that microbial aggregates were formed in the enrichments. It appeared that the average cell-to-cell distance in aggregates in nanomaterial-amended enrichments was larger than that in aggregates in the non-amended control. These results suggested that DIET-mediated syntrophic methanogenesis could occur in the lake sediments in the presence of conductive materials. Microbial community analysis of the enrichments revealed that the genera of Syntrophomonas, Sulfurospirillum, Methanosarcina, and Methanoregula were responsible for syntrophic oxidation of butyrate in lake sediment samples. The mechanism for the conductive-material-facilitated DIET in butyrate syntrophy deserves further investigation. PMID:27597850

  8. Small nickel nanoparticle arrays from long chain imidazolium ionic liquids

    SciTech Connect

    Yang, Mei; Campbell, Paul S.; Santini, Catherine C.; Mudring, Anja -Verena

    2013-11-08

    A series of six long chain alkyl mono- and bi-cationic imidazolium based salts with bis(trifluoromethylsulfonyl)imide (NTf2–) as the anion were synthesized and characterized. Single crystal structure of 1-methyl-3-octadecylimidazolium bis(trifluoromethylsulfonyl)imide could be obtained by X-ray analysis. All these long chain alkyl imidazolium based ILs were applied in the synthesis of nickel nanoparticles via chemical decomposition of an organometallic precursor of nickel. In these media, spontaneous decomposition of Ni(COD)2 (COD = 1,5-cyclooctadiene) in the absence of H2 occurred giving small NPs (≤4 nm) with narrow size distributions. Interestingly, formation of regularly interspaced NP arrays was also observed in long chain ILs. Lastly, such array formation could be interesting for potential applications such as carbon nanotube growth.

  9. Small nickel nanoparticle arrays from long chain imidazolium ionic liquids

    DOE PAGESBeta

    Yang, Mei; Campbell, Paul S.; Santini, Catherine C.; Mudring, Anja -Verena

    2013-11-08

    A series of six long chain alkyl mono- and bi-cationic imidazolium based salts with bis(trifluoromethylsulfonyl)imide (NTf2–) as the anion were synthesized and characterized. Single crystal structure of 1-methyl-3-octadecylimidazolium bis(trifluoromethylsulfonyl)imide could be obtained by X-ray analysis. All these long chain alkyl imidazolium based ILs were applied in the synthesis of nickel nanoparticles via chemical decomposition of an organometallic precursor of nickel. In these media, spontaneous decomposition of Ni(COD)2 (COD = 1,5-cyclooctadiene) in the absence of H2 occurred giving small NPs (≤4 nm) with narrow size distributions. Interestingly, formation of regularly interspaced NP arrays was also observed in long chain ILs. Lastly,more » such array formation could be interesting for potential applications such as carbon nanotube growth.« less

  10. Quantitative detection of syntrophic fatty acid-degrading bacterial communities in methanogenic environments.

    PubMed

    Mathai, Prince P; Zitomer, Daniel H; Maki, James S

    2015-06-01

    In methanogenic habitats, volatile fatty acids (VFA), such as propionate and butyrate, are major intermediates in organic matter degradation. VFA are further metabolized to H(2), acetate and CO(2) by syntrophic fatty acid-degrading bacteria (SFAB) in association with methanogenic archaea. Despite their indispensable role in VFA degradation, little is known about SFAB abundance and their environmental distribution. To facilitate ecological studies, we developed four novel genus-specific quantitative PCR (qPCR) assays, with primer sets targeting known SFAB: Syntrophobacter, Smithella, Pelotomaculum and Syntrophomonas. Primer set specificity was confirmed using in silico and experimental (target controls, clone libraries and melt-curve analysis) approaches. These qPCR assays were applied to quantify SFAB in a variety of mesophilic methanogenic habitats, including a laboratory propionate enrichment culture, pilot- and full-scale anaerobic reactors, cow rumen, horse faeces, an experimental rice paddy soil, a bog stream and swamp sediments. The highest SFAB 16S rRNA gene copy numbers were found in the propionate enrichment culture and anaerobic reactors, followed by the bog stream and swamp sediment samples. In addition, it was observed that SFAB and methanogen abundance varied with reactor configuration and substrate identity. To our knowledge, this research represents the first comprehensive study to quantify SFAB in methanogenic habitats using qPCR-based methods. These molecular tools will help investigators better understand syntrophic microbial communities in engineered and natural environments. PMID:25814038

  11. 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.

    2015-05-22

    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.

  12. 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. PMID:26000553

  13. Long chain fatty acids and dietary fats in fetal nutrition

    PubMed Central

    Cetin, Irene; Alvino, Gioia; Cardellicchio, Manuela

    2009-01-01

    Long chain polyunsaturated fatty acids are essential nutrients for a healthy diet. The different kinds consumed by the mother during gestation and lactation may influence pregnancy, fetal and also neonatal outcome. The amount of fatty acids transferred from mother to fetus depends not only on maternal metabolism but also on placental function, i.e. by the uptake, metabolism and then transfer of fatty acids to the fetus. The third trimester of gestation is characterized by an increase of long chain polyunsaturated fatty acids in the fetal circulation, in particular docosahexaenoic acid, especially to support brain growth and visual development. These mechanisms may be altered in pathological conditions, such as intrauterine growth restriction and diabetes, when maternal and fetal plasma levels of long chain polyunsaturated fatty acids undergo significant changes. The aim of this review is to describe the maternal and placental factors involved in determining fetal fatty acid availability and metabolism, focusing on the specific role of long chain polyunsaturated fatty acids in normal and pathological pregnancies. PMID:19528253

  14. Radiolabeled dimethyl branched long chain fatty acid for heart imaging

    DOEpatents

    Knapp, Jr., Furn F.; Goodman, Mark M.; Kirsch, Gilbert

    1988-08-16

    A radiolabeled long chain fatty acid for heart imaging that has dimethyl branching at one of the carbons of the chain which inhibits the extent to which oxidation can occur. The closer to the carboxyl the branching is positioned, the more limited the oxidation, thereby resulting in prolonged retention of the radiolabeled compound in the heart.

  15. Sphingoid long chain bases prevent lung infection by Pseudomonas aeruginosa

    PubMed Central

    Pewzner-Jung, Yael; Tavakoli Tabazavareh, Shaghayegh; Grassmé, Heike; Becker, Katrin Anne; Japtok, Lukasz; Steinmann, Jörg; Joseph, Tammar; Lang, Stephan; Tuemmler, Burkhard; Schuchman, Edward H; Lentsch, Alex B; Kleuser, Burkhard; Edwards, Michael J; Futerman, Anthony H; Gulbins, Erich

    2014-01-01

    Cystic fibrosis patients and patients with chronic obstructive pulmonary disease, trauma, burn wound, or patients requiring ventilation are susceptible to severe pulmonary infection by Pseudomonas aeruginosa. Physiological innate defense mechanisms against this pathogen, and their alterations in lung diseases, are for the most part unknown. We now demonstrate a role for the sphingoid long chain base, sphingosine, in determining susceptibility to lung infection by P. aeruginosa. Tracheal and bronchial sphingosine levels were significantly reduced in tissues from cystic fibrosis patients and from cystic fibrosis mouse models due to reduced activity of acid ceramidase, which generates sphingosine from ceramide. Inhalation of mice with sphingosine, with a sphingosine analog, FTY720, or with acid ceramidase rescued susceptible mice from infection. Our data suggest that luminal sphingosine in tracheal and bronchial epithelial cells prevents pulmonary P. aeruginosa infection in normal individuals, paving the way for novel therapeutic paradigms based on inhalation of acid ceramidase or of sphingoid long chain bases in lung infection. PMID:25085879

  16. High-rate anaerobic treatment of Fischer-Tropsch wastewater in a packed-bed biofilm reactor.

    PubMed

    Majone, Mauro; Aulenta, Federico; Dionisi, Davide; D'Addario, Ezio N; Sbardellati, Rosa; Bolzonella, David; Beccari, Mario

    2010-05-01

    This study investigates the anaerobic treatment of an industrial wastewater from a Fischer-Tropsch (FT) process in a continuous-flow packed-bed biofilm reactor operated under mesophilic conditions (35 degrees C). The considered synthetic wastewater has an overall chemical oxygen demand (COD) concentration of around 28g/L, mainly due to alcohols. A gradual increase of the organic load rate (OLR), from 3.4gCOD/L/d up to 20gCOD/L/d, was adopted in order to overcome potential inhibitory effects due to long-chain alcohols (>C6). At the highest applied OLR (i.e., 20gCOD/L/d) and a hydraulic retention time of 1.4d, the COD removal was 96% with nearly complete conversion of the removed COD into methane. By considering a potential of 200tCOD/d to be treated, this would correspond to a net production of electric energy of about 8x10(7)kWh/year. During stable reactor operation, a COD balance and batch tests showed that about 80% of the converted COD was directly metabolized through H(2)(-) and acetate-releasing reactions, which proceeded in close syntrophic cooperation with hydrogenotrophic and acetoclastic methanogenesis (contributing to about 33% and 54% of overall methane production, respectively). Finally, energetic considerations indicated that propionic acid oxidation was the metabolic conversion step most dependent on the syntrophic partnership of hydrogenotrophic methanogens and accordingly the most susceptible to variations of the applied OLR or toxicity effects. PMID:20202665

  17. Assignment of fatty acid-beta-oxidizing syntrophic bacteria to Syntrophomonadaceae fam. nov. on the basis of 16S rRNA sequence analyses

    NASA Technical Reports Server (NTRS)

    Zhao, H.; Yang, D.; Woese, C. R.; Bryant, M. P.

    1993-01-01

    After enrichment from Chinese rural anaerobic digestor sludge, anaerobic, sporing and nonsporing, saturated fatty acid-beta-oxidizing syntrophic bacteria were isolated as cocultures with H2- and formate-utilizing Methanospirillum hungatei or Desulfovibrio sp. strain G-11. The syntrophs degraded C4 to C8 saturated fatty acids, including isobutyrate and 2-methylbutyrate. They were adapted to grow on crotonate and were isolated as pure cultures. The crotonate-grown pure cultures alone did not grow on butyrate in either the presence or the absence of some common electron acceptors. However, when they were reconstituted with M. hungatei, growth on butyrate again occurred. In contrast, crotonate-grown Clostridium kluyveri and Clostridium sticklandii, as well as Clostridium sporogenes, failed to grow on butyrate when these organisms were cocultured with M. hungatei. The crotonate-grown pure subcultures of the syntrophs described above were subjected to 16S rRNA sequence analysis. Several previously documented fatty acid-beta-oxidizing syntrophs grown in pure cultures with crotonate were also subjected to comparative sequence analyses. The sequence analyses revealed that the new sporing and nonsporing isolates and other syntrophs that we sequenced, which had either gram-negative or gram-positive cell wall ultrastructure, all belonged to the phylogenetically gram-positive phylum. They were not closely related to any of the previously known subdivisions in the gram-positive phylum with which they were compared, but were closely related to each other, forming a new subdivision in the phylum. We recommend that this group be designated Syntrophomonadaceae fam. nov.; a description is given.

  18. Genome-guided analysis of physiological capacities of Tepidanaerobacter acetatoxydans provides insights into environmental adaptations and syntrophic acetate oxidation.

    PubMed

    Müller, Bettina; Manzoor, Shahid; Niazi, Adnan; Bongcam-Rudloff, Erik; Schnürer, Anna

    2015-01-01

    This paper describes the genome-based analysis of Tepidanaerobacter acetatoxydans strain Re1, a syntrophic acetate-oxidising bacterium (SAOB). Principal issues such as environmental adaptations, metabolic capacities, and energy conserving systems have been investigated and the potential consequences for syntrophic acetate oxidation discussed. Briefly, in pure culture, T. acetatoxydans grows with different organic compounds and produces acetate as the main product. In a syntrophic consortium with a hydrogenotrophic methanogen, it can also reverse its metabolism and instead convert acetate to formate/H2 and CO2. It can only proceed if the product formed is continuously removed. This process generates a very small amount of energy that is scarcely enough for growth, which makes this particular syntrophy of special interest. As a crucial member of the biogas-producing community in ammonium-rich engineered AD processes, genomic features conferring ammonium resistance, bacterial defense, oxygen and temperature tolerance were found, as well as attributes related to biofilm formation and flocculation. It is likely that T. acetatoxydans can form an electrochemical gradient by putative electron-bifurcating Rnf complex and [Fe-Fe] hydrogenases, as observed in other acetogens. However, genomic deficiencies related to acetogenic metabolism and anaerobic respiration were discovered, such as the lack of formate dehydrogenase and F1F0 ATP synthase. This has potential consequences for the metabolic pathways used under SAO and non-SAO conditions. The two complete sets of bacteriophage genomes, which were found to be encoded in the genome, are also worthy of mention. PMID:25811859

  19. Genome-Guided Analysis of Physiological Capacities of Tepidanaerobacter acetatoxydans Provides Insights into Environmental Adaptations and Syntrophic Acetate Oxidation

    PubMed Central

    Niazi, Adnan; Bongcam-Rudloff, Erik; Schnürer, Anna

    2015-01-01

    This paper describes the genome-based analysis of Tepidanaerobacter acetatoxydans strain Re1, a syntrophic acetate-oxidising bacterium (SAOB). Principal issues such as environmental adaptations, metabolic capacities, and energy conserving systems have been investigated and the potential consequences for syntrophic acetate oxidation discussed. Briefly, in pure culture, T. acetatoxydans grows with different organic compounds and produces acetate as the main product. In a syntrophic consortium with a hydrogenotrophic methanogen, it can also reverse its metabolism and instead convert acetate to formate/H2 and CO2. It can only proceed if the product formed is continuously removed. This process generates a very small amount of energy that is scarcely enough for growth, which makes this particular syntrophy of special interest. As a crucial member of the biogas-producing community in ammonium-rich engineered AD processes, genomic features conferring ammonium resistance, bacterial defense, oxygen and temperature tolerance were found, as well as attributes related to biofilm formation and flocculation. It is likely that T. acetatoxydans can form an electrochemical gradient by putative electron-bifurcating Rnf complex and [Fe-Fe] hydrogenases, as observed in other acetogens. However, genomic deficiencies related to acetogenic metabolism and anaerobic respiration were discovered, such as the lack of formate dehydrogenase and F1F0 ATP synthase. This has potential consequences for the metabolic pathways used under SAO and non-SAO conditions. The two complete sets of bacteriophage genomes, which were found to be encoded in the genome, are also worthy of mention. PMID:25811859

  20. Study of Triheptanoin for Treatment of Long-Chain Fatty Acid Oxidation Disorder

    ClinicalTrials.gov

    2015-04-20

    Very Long-chain acylCoA Dehydrogenase (VLCAD) Deficiency; Carnitine Palmitoyltransferase 2 (CPT2) Deficiency; Mitochondrial Trifunctional Protein (TFP) Deficiency; Long-chain 3 hydroxyacylCoA Dehydrogenase (LCHAD) Deficiency

  1. Long-chain alkane production by the yeast Saccharomyces cerevisiae.

    PubMed

    Buijs, Nicolaas A; Zhou, Yongjin J; Siewers, Verena; Nielsen, Jens

    2015-06-01

    In the past decade industrial-scale production of renewable transportation biofuels has been developed as an alternative to fossil fuels, with ethanol as the most prominent biofuel and yeast as the production organism of choice. However, ethanol is a less efficient substitute fuel for heavy-duty and maritime transportation as well as aviation due to its low energy density. Therefore, new types of biofuels, such as alkanes, are being developed that can be used as drop-in fuels and can substitute gasoline, diesel, and kerosene. Here, we describe for the first time the heterologous biosynthesis of long-chain alkanes by the yeast Saccharomyces cerevisiae. We show that elimination of the hexadecenal dehydrogenase Hfd1 and expression of a redox system are essential for alkane biosynthesis in yeast. Deletion of HFD1 together with expression of an alkane biosynthesis pathway resulted in the production of the alkanes tridecane, pentadecane, and heptadecane. Our study provides a proof of principle for producing long-chain alkanes in the industrial workhorse S. cerevisiae, which was so far limited to bacteria. We anticipate that these findings will be a key factor for further yeast engineering to enable industrial production of alkane based drop-in biofuels, which can allow the biofuel industry to diversify beyond bioethanol. PMID:25545362

  2. 21 CFR 178.3780 - Polyhydric alcohol esters of long chain monobasic acids.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... produced by the reaction of either ethylene glycol or glycerol with long chain monobasic acids containing... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Polyhydric alcohol esters of long chain monobasic... Adjuvants and Production Aids § 178.3780 Polyhydric alcohol esters of long chain monobasic acids....

  3. Unique plasma metabolomic signatures of individuals with inherited disorders of long-chain fatty acid oxidation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Blood and urine acylcarnitine profiles are commonly used to diagnose long-chain fatty acid oxidation disorders (FAOD: i.e., long-chain hydroxy-acyl-CoA dehydrogenase [LCHAD] and carnitine palmitoyltransferase 2 [CPT2] deficiency), but the global metabolic impact of long-chain FAOD has not been repor...

  4. Long-chain terminal alcohols through catalytic CO hydrogenation.

    PubMed

    Xiang, Yizhi; Chitry, Véronique; Liddicoat, Peter; Felfer, Peter; Cairney, Julie; Ringer, Simon; Kruse, Norbert

    2013-05-15

    We show that long-chain 1-alcohols can be produced with high selectivities using heterogeneous CO hydrogenation catalysis. This breakthrough is achieved through the targeted design of "CoCuMn" nanosized core-shell particles using co-precipitation of metal salts into oxalate precursors and subsequent thermal decomposition. Using stoichiometric CO/H2 feeds, the selectivities to 1-alcohols or combined 1-alcohols/1-alkenes are usually higher than 60% and occasionally up to 95%. The Anderson-Schulz-Flory chain-lengthening probabilities for these products are higher than 0.6, but usually below 0.9 so as to optimize the C8-C14 slate as feedstock for plasticizers, lubricants, or detergents. PMID:23634891

  5. Plasma long-chain free fatty acids predict mammalian longevity

    PubMed Central

    Jové, Mariona; Naudí, Alba; Aledo, Juan Carlos; Cabré, Rosanna; Ayala, Victoria; Portero-Otin, Manuel; Barja, Gustavo; Pamplona, Reinald

    2013-01-01

    Membrane lipid composition is an important correlate of the rate of aging of animals and, therefore, the determination of their longevity. In the present work, the use of high-throughput technologies allowed us to determine the plasma lipidomic profile of 11 mammalian species ranging in maximum longevity from 3.5 to 120 years. The non-targeted approach revealed a specie-specific lipidomic profile that accurately predicts the animal longevity. The regression analysis between lipid species and longevity demonstrated that the longer the longevity of a species, the lower is its plasma long-chain free fatty acid (LC-FFA) concentrations, peroxidizability index, and lipid peroxidation-derived products content. The inverse association between longevity and LC-FFA persisted after correction for body mass and phylogenetic interdependence. These results indicate that the lipidomic signature is an optimized feature associated with animal longevity, emerging LC-FFA as a potential biomarker of longevity. PMID:24284984

  6. Toxicity of long chain fatty acids towards acetate conversion by Methanosaeta concilii and Methanosarcina mazei.

    PubMed

    Silva, Sérgio A; Salvador, Andreia F; Cavaleiro, Ana J; Pereira, M Alcina; Stams, Alfons J M; Alves, M Madalena; Sousa, Diana Z

    2016-07-01

    Long-chain fatty acids (LCFA) can inhibit methane production by methanogenic archaea. The effect of oleate and palmitate on pure cultures of Methanosaeta concilii and Methanosarcina mazei was assessed by comparing methane production rates from acetate before and after LCFA addition. For both methanogens, a sharp decrease in methane production (> 50%) was observed at 0.5 mmol L(-1) oleate, and no methane was formed at concentrations higher than 2 mmol L(-1) oleate. Palmitate was less inhibitory than oleate, and M. concilii was more tolerant to palmitate than M. mazei, with 2 mmol L(-1) palmitate causing 11% and 64% methanogenic inhibition respectively. This study indicates that M. concilii and M. mazei tolerate LCFA concentrations similar to those previously described for hydrogenotrophic methanogens. In particular, the robustness of M. concilii might contribute to the observed prevalence of Methanosaeta species in anaerobic bioreactors used to treat LCFA-rich wastewater. PMID:27273786

  7. Two Pathways for Glutamate Biosynthesis in the Syntrophic Bacterium Syntrophus aciditrophicus

    PubMed Central

    Kim, Marie; Le, Huynh M.; Xie, Xiulan; Feng, Xueyang; Tang, Yinjie J.; Mouttaki, Housna; McInerney, Michael J.

    2015-01-01

    The anaerobic metabolism of crotonate, benzoate, and cyclohexane carboxylate by Syntrophus aciditrophicus grown syntrophically with Methanospirillum hungatei provides a model to study syntrophic cooperation. Recent studies revealed that S. aciditrophicus contains Re-citrate synthase but lacks the common Si-citrate synthase. To establish whether the Re-citrate synthase is involved in glutamate synthesis via the oxidative branch of the Krebs cycle, we have used [1-13C]acetate and [1-14C]acetate as well as [13C]bicarbonate as additional carbon sources during axenic growth of S. aciditrophicus on crotonate. Our analyses showed that labeled carbons were detected in at least 14 amino acids, indicating the global utilization of acetate and bicarbonate. The labeling patterns of alanine and aspartate verified that pyruvate and oxaloacetate were synthesized by consecutive carboxylations of acetyl coenzyme A (acetyl-CoA). The isotopomer profile and 13C nuclear magnetic resonance (NMR) spectroscopy of the obtained [13C]glutamate, as well as decarboxylation of [14C]glutamate, revealed that this amino acid was synthesized by two pathways. Unexpectedly, only the minor route used Re-citrate synthase (30 to 40%), whereas the majority of glutamate was synthesized via the reductive carboxylation of succinate. This symmetrical intermediate could have been formed from two acetates via hydration of crotonyl-CoA to 4-hydroxybutyryl-CoA. 4-Hydroxybutyrate was detected in the medium of S. aciditrophicus when grown on crotonate, but an active hydratase could not be measured in cell extracts, and the annotated 4-hydroxybutyryl-CoA dehydratase (SYN_02445) lacks key amino acids needed to catalyze the hydration of crotonyl-CoA. Besides Clostridium kluyveri, this study reveals the second example of a microbial species to employ two pathways for glutamate synthesis. PMID:26431966

  8. Bioaugmentation of Syntrophic Acetate-Oxidizing Culture in Biogas Reactors Exposed to Increasing Levels of Ammonia

    PubMed Central

    Westerholm, Maria; Levén, Lotta

    2012-01-01

    The importance of syntrophic acetate oxidation for process stability in methanogenic systems operating at high ammonia concentrations has previously been emphasized. In this study we investigated bioaugmentation of syntrophic acetate-oxidizing (SAO) cultures as a possible method for decreasing the adaptation period of biogas reactors operating at gradually increased ammonia concentrations (1.5 to 11 g NH4+-N/liter). Whole stillage and cattle manure were codigested semicontinuously for about 460 days in four mesophilic anaerobic laboratory-scale reactors, and a fixed volume of SAO culture was added daily to two of the reactors. Reactor performance was evaluated in terms of biogas productivity, methane content, pH, alkalinity, and volatile fatty acid (VFA) content. The decomposition pathway of acetate was analyzed by isotopic tracer experiments, and population dynamics were monitored by quantitative PCR analyses. A shift in dominance from aceticlastic methanogenesis to SAO occurred simultaneously in all reactors, indicating no influence by bioaugmentation on the prevailing pathway. Higher abundances of Clostridium ultunense and Tepidanaerobacter acetatoxydans were associated with bioaugmentation, but no influence on Syntrophaceticus schinkii or the methanogenic population was distinguished. Overloading or accumulation of VFA did not cause notable dynamic effects on the population. Instead, the ammonia concentration had a substantial impact on the abundance level of the microorganisms surveyed. The addition of SAO culture did not affect process performance or stability against ammonia inhibition, and all four reactors deteriorated at high ammonia concentrations. Consequently, these findings further demonstrate the strong influence of ammonia on the methane-producing consortia and on the representative methanization pathway in mesophilic biogas reactors. PMID:22923397

  9. Two pathways for glutamate biosynthesis in the syntrophic bacterium Syntrophus aciditrophicus.

    PubMed

    Kim, Marie; Le, Huynh M; Xie, Xiulan; Feng, Xueyang; Tang, Yinjie J; Mouttaki, Housna; McInerney, Michael J; Buckel, Wolfgang

    2015-12-01

    The anaerobic metabolism of crotonate, benzoate, and cyclohexane carboxylate by Syntrophus aciditrophicus grown syntrophically with Methanospirillum hungatei provides a model to study syntrophic cooperation. Recent studies revealed that S. aciditrophicus contains Re-citrate synthase but lacks the common Si-citrate synthase. To establish whether the Re-citrate synthase is involved in glutamate synthesis via the oxidative branch of the Krebs cycle, we have used [1-(13)C]acetate and [1-(14)C]acetate as well as [(13)C]bicarbonate as additional carbon sources during axenic growth of S. aciditrophicus on crotonate. Our analyses showed that labeled carbons were detected in at least 14 amino acids, indicating the global utilization of acetate and bicarbonate. The labeling patterns of alanine and aspartate verified that pyruvate and oxaloacetate were synthesized by consecutive carboxylations of acetyl coenzyme A (acetyl-CoA). The isotopomer profile and (13)C nuclear magnetic resonance (NMR) spectroscopy of the obtained [(13)C]glutamate, as well as decarboxylation of [(14)C]glutamate, revealed that this amino acid was synthesized by two pathways. Unexpectedly, only the minor route used Re-citrate synthase (30 to 40%), whereas the majority of glutamate was synthesized via the reductive carboxylation of succinate. This symmetrical intermediate could have been formed from two acetates via hydration of crotonyl-CoA to 4-hydroxybutyryl-CoA. 4-Hydroxybutyrate was detected in the medium of S. aciditrophicus when grown on crotonate, but an active hydratase could not be measured in cell extracts, and the annotated 4-hydroxybutyryl-CoA dehydratase (SYN_02445) lacks key amino acids needed to catalyze the hydration of crotonyl-CoA. Besides Clostridium kluyveri, this study reveals the second example of a microbial species to employ two pathways for glutamate synthesis. PMID:26431966

  10. Long-chain n-3 PUFA: plant v. marine sources.

    PubMed

    Williams, Christine M; Burdge, Graham

    2006-02-01

    Increasing recognition of the importance of the long-chain n-3 PUFA, EPA and DHA, to cardiovascular health, and in the case of DHA to normal neurological development in the fetus and the newborn, has focused greater attention on the dietary supply of these fatty acids. The reason for low intakes of EPA and DHA in most developed countries (0.1-0.5 g/d) is the low consumption of oily fish, the richest dietary source of these fatty acids. An important question is whether dietary intake of the precursor n-3 fatty acid, alpha-linolenic acid (alphaLNA), can provide sufficient amounts of tissue EPA and DHA by conversion through the n-3 PUFA elongation-desaturation pathway. alphaLNA is present in marked amounts in plant sources, including green leafy vegetables and commonly-consumed oils such as rape-seed and soyabean oils, so that increased intake of this fatty acid would be easier to achieve than via increased fish consumption. However, alphaLNA-feeding studies and stable-isotope studies using alphaLNA, which have addressed the question of bioconversion of alphaLNA to EPA and DHA, have concluded that in adult men conversion to EPA is limited (approximately 8%) and conversion to DHA is extremely low (<0.1%). In women fractional conversion to DHA appears to be greater (9%), which may partly be a result of a lower rate of utilisation of alphaLNA for beta-oxidation in women. However, up-regulation of the conversion of EPA to DHA has also been suggested, as a result of the actions of oestrogen on Delta6-desaturase, and may be of particular importance in maintaining adequate provision of DHA in pregnancy. The effect of oestrogen on DHA concentration in pregnant and lactating women awaits confirmation. PMID:16441943

  11. Genomic Analysis of Genes Involved in the Biosynthesis of Very Long Chain Polyunsaturated Fatty Acids in Thraustochytrium sp. 26185.

    PubMed

    Zhao, Xianming; Dauenpen, Meesapyodsuk; Qu, Cunmin; Qiu, Xiao

    2016-09-01

    Thraustochytrium sp. 26185 is a marine protist that can produce a large amount of docosahexaenoic acid (DHA, 22:6n-3), an ω3 very long chain polyunsaturated fatty acid (VLCPUFA) of nutritional importance. However, the mechanism of how this fatty acid is synthesized and assembled into the storage lipid triacylglycerol is unclear. Here we report sequencing of the whole genome and genomic analysis of genes involved in the biosynthesis and assembly of the fatty acids in this species. Genome sequencing produced a total of 2,418,734,139 bp clean sequences with about 62 fold genome coverage. Annotation of the genome sequences revealed 10,797 coding genes. Among them, 10,216 genes could be assigned into 25 KOG classes where 451 genes were specifically assigned to the group of lipid transport and metabolism. Detailed analysis of these genes revealed co-existence of both aerobic pathway and anaerobic pathways for the biosynthesis of DHA in this species. However, in the aerobic pathway, a key gene encoding stearate Δ9 desaturase introducing the first double bond to long chain saturated fatty acid 18:0 was missing from the genome. Genomic survey of genes involved in the acyl trafficking among glycerolipids showed that, unlike plants, this protist did not possess phosphatidylcholine:diacylglycerol cholinephosphotransferase, an important enzyme in bridging two types of glycerolipids, diacylglycerols (DAG) and phosphatidylcholines (PtdCho). These results shed new insight on the biosynthesis and assembly of VLCPUFA in the Thraustochytrium. PMID:27514858

  12. 40 CFR 721.10536 - Long-chain perfluoroalkyl carboxylate chemical substances.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Long-chain perfluoroalkyl carboxylate... Specific Chemical Substances § 721.10536 Long-chain perfluoroalkyl carboxylate chemical substances. (a... paragraph (b)(3) of this section. (3) Manufacture (including import) or processing of the following two...

  13. Genetics Home Reference: very long-chain acyl-CoA dehydrogenase deficiency

    MedlinePlus

    ... metabolize) a group of fats called very long-chain fatty acids. These fatty acids are found in foods and the body's fat tissues. Fatty acids are a major source of energy for the heart and muscles. During periods of fasting, ... of this enzyme, very long-chain fatty acids are not metabolized properly. As a ...

  14. Genetics Home Reference: long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency

    MedlinePlus

    ... These mutations prevent the normal processing of long-chain fatty acids from food and body fat. As a result, these fatty acids are not converted to energy, which can lead to some features of this disorder, ... Long-chain fatty acids or partially metabolized fatty acids may ...

  15. Syntrophic acetate oxidation in industrial CSTR biogas digesters.

    PubMed

    Sun, Li; Müller, Bettina; Westerholm, Maria; Schnürer, Anna

    2014-02-10

    The extent of syntrophic acetate oxidation (SAO) and the levels of known SAO bacteria and acetate- and hydrogen-consuming methanogens were determined in sludge from 13 commercial biogas production plants. Results from these measurements were statistically related to the prevailing operating conditions, through partial least squares (PLS) analysis. This revealed that high abundance of microorganisms involved in SAO was positively correlated with relatively low abundance of aceticlastic methanogens and high concentrations of free ammonia (>160 mg/L) and volatile fatty acids (VFA). Temperature was identified as another influencing factor for the population structure of the syntrophic acetate oxidising bacteria (SAOB). Overall, there was a high abundance of SAOB in the different digesters despite differences in their operating parameters, indicating that SAOB are an enduring and important component of biogas-producing consortia. PMID:24333792

  16. Magnetic properties of cubic FeCo nanoparticles with anisotropic long chain structure

    NASA Astrophysics Data System (ADS)

    Liu, Jinming; Wu, Kai; Wang, Jian-Ping

    2016-05-01

    Cubic FeCo alloy nanoparticles (NPs) with body-centered cubic (bcc) phase were prepared using sputter based gas-condensation method. When the NPs formed long chain assemblies, the magnetic properties were quite different from that of well-dispersed NPs. Most of the well-dispersed NPs were superparamagnetic at room temperature while the long chain NP assemblies were ferromagnetic with coercivities around 765 Oe, which displayed quite different magnetic properties. The ferromagnetism of long chain NPs was from the exchange coupling between NPs, which eventually led to the transition from superparamagnetism (SPM) to superferromagetism (SFM). Zero-field-cooled (ZFC) and field-cooled (FC) curves were obtained and long chain NP assemblies displayed ferromagnetism at the temperature ranging from 10 K to 400 K. Time-dependent remanent magnetic moment curves also indicated that the long chain structure had better thermal stability due to the strong exchange coupling.

  17. Methane Production and Syntrophic Acetate Oxidation in the Florida Everglades

    NASA Astrophysics Data System (ADS)

    Holmes, M. E.; Chanton, J.; Bae, H.; Ogram, A.

    2012-12-01

    Methane production pathways in the Florida Everglades are influenced by factors such as nutrient levels, H2 concentrations, and temperature. Syntrophic acetate oxidizers can outcompete methanogens for acetate when conditions are right (high temperatures and low H2). During syntrophic acetate oxidation (SAO), which becomes more exergonic with increasing temperature, acetate is oxidized to carbon dioxide and H2, which can be utilized to produce methane via CO2 reduction. Everglades soil from along a nutrient gradient was incubated at 25°C and 45°C. The shift to the CO2 reduction pathway for methane formation that would be expected in high temperature incubations due to SAO should result in a decrease in δ13C-CH4 and increase in δ2H-CH4. Instead, we observed higher δ13C and lower δ2H in the methane produced in high temperature incubations. The higher than expected δ13C may be partly explained by lower kinetic isotope effects caused by temperature. Coupling between the syntrophic acetate oxidizers and the CO2 reducers, whereby isotopically light hydrogen from acetate is used in methane formation could lower δ2H-CH4. Separate experiments using 13C-labelled acetate revealed that potential SAO activity is low in soils collected from the Everglades.

  18. Limitation of syntrophic coculture growth by the acetogen.

    PubMed

    Junicke, Helena; Feldman, Hannah; Van Loosdrecht, Mark C M; Kleerebezem, Robbert

    2016-03-01

    The syntrophic cooperation between hydrogen-producing acetogens and hydrogenotrophic methanogens relies on a critical balance between both partners. A recent study, provided several indications for the dependence of the biomass-specific growth rate of a methanogenic coculture on the acetogen. Nevertheless, final experimental proof was lacking since biomass-specific rates were obtained from a descriptive model, and not from direct measurement of individual biomass concentrations. In this study, a recently developed quantitative PCR approach was used to measure the individual biomass concentrations in the coculture of Desulfovibrio sp. G11 and Methanospirillum hungatei JF1 on lactate, formate or both. The model-derived growth yields and biomass-specific rates were successfully validated. Experimental findings identified the acetogen as the growth-limiting partner in the coculture on lactate. While the acetogen was operating at its maximum biomass-specific lactate consumption rate, the hydrogenotrophic methanogen showed a significant overcapacity. Furthermore, this study provides experimental evidence for different growth strategies followed by the syntrophic partners in order to maintain a common biomass-specific growth rate. During syntrophic lactate conversion, the biomass-specific electron transfer rate of Methanospirillum hungatei JF1 was three-fold higher compared to Desulfovibrio sp. G11. This is to compensate for the lower methanogenic biomass yield per electron-mole of substrate, which is dictated by the thermodynamics of the underlying reaction. PMID:26301789

  19. Syntrophic Growth of Desulfovibrio alaskensis Requires Genes for H2 and Formate Metabolism as Well as Those for Flagellum and Biofilm Formation

    PubMed Central

    Bradstock, Peter; Sheik, Cody S.; Diao, Yiwei; Gazioglu, Ozcan; Gorby, Yuri; McInerney, Michael J.

    2015-01-01

    In anaerobic environments, mutually beneficial metabolic interactions between microorganisms (syntrophy) are essential for oxidation of organic matter to carbon dioxide and methane. Syntrophic interactions typically involve a microorganism degrading an organic compound to primary fermentation by-products and sources of electrons (i.e., formate, hydrogen, or nanowires) and a partner producing methane or respiring the electrons via alternative electron accepting processes. Using a transposon gene mutant library of the sulfate-reducing Desulfovibrio alaskensis G20, we screened for mutants incapable of serving as the electron-accepting partner of the butyrate-oxidizing bacterium, Syntrophomonas wolfei. A total of 17 gene mutants of D. alaskensis were identified as incapable of serving as the electron-accepting partner. The genes identified predominantly fell into three categories: membrane surface assembly, flagellum-pilus synthesis, and energy metabolism. Among these genes required to serve as the electron-accepting partner, the glycosyltransferase, pilus assembly protein (tadC), and flagellar biosynthesis protein showed reduced biofilm formation, suggesting that each of these components is involved in cell-to-cell interactions. Energy metabolism genes encoded proteins primarily involved in H2 uptake and electron cycling, including a rhodanese-containing complex that is phylogenetically conserved among sulfate-reducing Deltaproteobacteria. Utilizing an mRNA sequencing approach, analysis of transcript abundance in wild-type axenic and cocultures confirmed that genes identified as important for serving as the electron-accepting partner were more highly expressed under syntrophic conditions. The results imply that sulfate-reducing microorganisms require flagellar and outer membrane components to effectively couple to their syntrophic partners; furthermore, H2 metabolism is essential for syntrophic growth of D. alaskensis G20. PMID:25616787

  20. Draft Genome Sequence of Clostridium ultunense Strain Esp, a Syntrophic Acetate-Oxidizing Bacterium.

    PubMed

    Manzoor, Shahid; Müller, Bettina; Niazi, Adnan; Bongcam-Rudloff, Erik; Schnürer, Anna

    2013-01-01

    Clostridium ultunense strain Esp belongs to the functional group of syntrophic acetate-oxidizing bacteria (SAOB), which have been identified as key organisms for efficient biogas production from protein-rich materials. Genome analysis and comparative genomics might aid us to define physiological features that are essential for maintaining this particular syntrophic lifestyle. PMID:23538905

  1. Draft Genome Sequence of Clostridium ultunense Strain Esp, a Syntrophic Acetate-Oxidizing Bacterium

    PubMed Central

    Manzoor, Shahid; Niazi, Adnan; Bongcam-Rudloff, Erik; Schnürer, Anna

    2013-01-01

    Clostridium ultunense strain Esp belongs to the functional group of syntrophic acetate-oxidizing bacteria (SAOB), which have been identified as key organisms for efficient biogas production from protein-rich materials. Genome analysis and comparative genomics might aid us to define physiological features that are essential for maintaining this particular syntrophic lifestyle. PMID:23538905

  2. Biostimulation induces syntrophic interactions that impact C, S and N cycling in a sediment microbial community

    PubMed Central

    Handley, Kim M; VerBerkmoes, Nathan C; Steefel, Carl I; Williams, Kenneth H; Sharon, Itai; Miller, Christopher S; Frischkorn, Kyle R; Chourey, Karuna; Thomas, Brian C; Shah, Manesh B; Long, Philip E; Hettich, Robert L; Banfield, Jillian F

    2013-01-01

    Stimulation of subsurface microorganisms to induce reductive immobilization of metals is a promising approach for bioremediation, yet the overall microbial community response is typically poorly understood. Here we used proteogenomics to test the hypothesis that excess input of acetate activates complex community functioning and syntrophic interactions among autotrophs and heterotrophs. A flow-through sediment column was incubated in a groundwater well of an acetate-amended aquifer and recovered during microbial sulfate reduction. De novo reconstruction of community sequences yielded near-complete genomes of Desulfobacter (Deltaproteobacteria), Sulfurovum- and Sulfurimonas-like Epsilonproteobacteria and Bacteroidetes. Partial genomes were obtained for Clostridiales (Firmicutes) and Desulfuromonadales-like Deltaproteobacteria. The majority of proteins identified by mass spectrometry corresponded to Desulfobacter-like species, and demonstrate the role of this organism in sulfate reduction (Dsr and APS), nitrogen fixation and acetate oxidation to CO2 during amendment. Results indicate less abundant Desulfuromonadales, and possibly Bacteroidetes, also actively contributed to CO2 production via the tricarboxylic acid (TCA) cycle. Proteomic data indicate that sulfide was partially re-oxidized by Epsilonproteobacteria through nitrate-dependent sulfide oxidation (using Nap, Nir, Nos, SQR and Sox), with CO2 fixed using the reverse TCA cycle. We infer that high acetate concentrations, aimed at stimulating anaerobic heterotrophy, led to the co-enrichment of, and carbon fixation in Epsilonproteobacteria. Results give an insight into ecosystem behavior following addition of simple organic carbon to the subsurface, and demonstrate a range of biological processes and community interactions were stimulated. PMID:23190730

  3. Long-Chain Aliphatic Polymers To Bridge the Gap between Semicrystalline Polyolefins and Traditional Polycondensates.

    PubMed

    Stempfle, Florian; Ortmann, Patrick; Mecking, Stefan

    2016-04-13

    Other than their established short-chain congeners, polycondensates based on long-chain difunctional monomers are often dominated by the long methylene sequences of the repeat units in their solid-state structures and properties. This places them between traditional polycondensates and polyethylenes. The availability of long-chain monomers as a key prerequisite has benefited much from advances in the catalytic conversion of plant oils, via biotechnological and purely chemical approaches, likewise. This has promoted studies of, among others, applications-relevant properties. A comprehensive account is given of long-chain monomer syntheses and the preparation and physical properties, morphologies, mechanical behavior, and degradability of long-chain polyester, polyamides, polyurethanes, polyureas, polyacetals, and polycarbonates. PMID:27023340

  4. Long-Chain Fatty Acid Oxidation Disorders (LC-FAOD) Extension Study for Subjects Previously Enrolled in Triheptanoin Studies.

    ClinicalTrials.gov

    2016-02-26

    Carnitine Palmitoyltransferase (CPT I or CPT II) Deficiency; Very Long Chain Acyl-CoA Dehydrogenase (VLCAD) Deficiency; Long-chain 3-hydroxy-acyl-CoA Dehydrogenase (LCHAD) Deficiency; Trifunctional Protein (TFP) Deficiency; Carnitine-acylcarnitine Translocase (CACT) Deficiency

  5. Strain hardening in startup shear of long-chain branched polymer solutions.

    PubMed

    Liu, Gengxin; Cheng, Shiwang; Lee, Hyojoon; Ma, Hongwei; Xu, Hongde; Chang, Taihyun; Quirk, Roderic P; Wang, Shi-Qing

    2013-08-01

    We show for the first time that entangled polymeric liquids containing long-chain branching can exhibit strain hardening upon startup shear. As the significant long-chain branching impedes chain disentanglement, Gaussian coils between entanglements can deform to reach the finite extensibility limit where the intrachain retraction force exceeds the value expected from the usual conformational entropy loss evaluated based on Gaussian chain statistics. The phenomenon is expected to lead to further theoretical understanding. PMID:23971617

  6. X-linked adrenoleukodystrophy with non-diagnostic plasma very long chain fatty acids.

    PubMed Central

    Kennedy, C R; Allen, J T; Fensom, A H; Steinberg, S J; Wilson, R

    1994-01-01

    Measurement of plasma very long chain fatty acids is widely recognised as a sensitive screening test for X-linked adrenoleukodystrophy (X-ALD). This test has particular importance because of the highly variable clinical expression of X-ALD. In this affected family the progressive childhood form of X-ALD was accompanied by "non-diagnostic" concentrations of plasma very long chain fatty acids. The implications for diagnosis of X-ALD are discussed. PMID:8006665

  7. Syntrophic Degradation of Lactate in Methanogenic Co-cultures

    SciTech Connect

    Meyer, Birte; Stahl, David

    2010-05-17

    In environments where the amount of the inorganic electron acceptors (oxygen, nitrate, sulfate, sulfur oroxidized metal ions (Fe3+;Mn4+) is insufficient for complete breakdown of organic matter, methane is formed as the major reduced end product. In such methanogenic environments organic acids are degraded by syntrophic associations of fermenting, acetogenic bacteria (e.g., sulfate-reducing bacteria (SRB) as"secondary fermenters") and methanogenic archaea. In these consortia, the conversion of lactate to acetate, CO2 and methane depends on the cooperating activities of both metabolically distinct microbial groups that are tightly linked by the need to maintain the exchanged metabolites (hydrogenandformate) at very low concentrations.

  8. Energetics and kinetics of anaerobic aromatic and fatty acid degradation. Progress report, November 1993--November 1994

    SciTech Connect

    McInerney, M.J.

    1994-12-06

    Factors influencing the rate and extent of benzoate degradation by the anaerobic syntrophic consortia were studied. Nonlinear regression analysis showed that the cause of the benzoate threshold was not a diminished benzoate degradation capacity. Analysis of cocultures with hydrogen users that differed in their hydrogen utilization capacities showed that the threshold did not depend on the kinetic properties of the syntrophic partner. These data support a thermodynamic explanation for the threshold, and exclude the possibility that a change in the affinity of the enzyme system due to acetate inhibition caused the threshold. Modeling studies showed that the threshold value could be predicted from the concentrations of the end products, assuming a critical Gibb`s free energy value. This work shows that interspecies acetate transfer is important in controlling the extent of metabolism by syntrophic organisms.

  9. Comparing activated carbon of different particle sizes on enhancing methane generation in upflow anaerobic digester.

    PubMed

    Xu, Suyun; He, Chuanqiu; Luo, Liwen; Lü, Fan; He, Pinjing; Cui, Lifeng

    2015-11-01

    Two sizes of conductive particles, i.e. 10-20 mesh granulated activated carbon (GAC) and 80-100 mesh powdered activated carbon (PAC) were added into lab-scale upflow anaerobic sludge blanket reactors, respectively, to testify their enhancement on the syntrophic metabolism of alcohols and volatile fatty acids (VFAs) in 95days operation. When OLR increased to more than 5.8gCOD/L/d, the differences between GAC/PAC supplemented reactors and the control reactor became more significant. The introduction of activated carbon could facilitate the enrichment of methanogens and accelerate the startup of methanogenesis, as indicated by enhanced methane yield and substrate degradation. High-throughput pyrosequencing analysis showed that syntrophic bacteria and Methanosarcina sp. with versatile metabolic capability increased in the tightly absorbed fraction on the PAC surface, leading to the promoted syntrophic associations. Thus PAC prevails over than GAC for methanogenic reactor with heavy load. PMID:26298405

  10. Long-chain Acylcarnitines Reduce Lung Function by Inhibiting Pulmonary Surfactant.

    PubMed

    Otsubo, Chikara; Bharathi, Sivakama; Uppala, Radha; Ilkayeva, Olga R; Wang, Dongning; McHugh, Kevin; Zou, Ye; Wang, Jieru; Alcorn, John F; Zuo, Yi Y; Hirschey, Matthew D; Goetzman, Eric S

    2015-09-25

    The role of mitochondrial energy metabolism in maintaining lung function is not understood. We previously observed reduced lung function in mice lacking the fatty acid oxidation enzyme long-chain acyl-CoA dehydrogenase (LCAD). Here, we demonstrate that long-chain acylcarnitines, a class of lipids secreted by mitochondria when metabolism is inhibited, accumulate at the air-fluid interface in LCAD(-/-) lungs. Acylcarnitine accumulation is exacerbated by stress such as influenza infection or by dietary supplementation with l-carnitine. Long-chain acylcarnitines co-localize with pulmonary surfactant, a unique film of phospholipids and proteins that reduces surface tension and prevents alveolar collapse during breathing. In vitro, the long-chain species palmitoylcarnitine directly inhibits the surface adsorption of pulmonary surfactant as well as its ability to reduce surface tension. Treatment of LCAD(-/-) mice with mildronate, a drug that inhibits carnitine synthesis, eliminates acylcarnitines and improves lung function. Finally, acylcarnitines are detectable in normal human lavage fluid. Thus, long-chain acylcarnitines may represent a risk factor for lung injury in humans with dysfunctional fatty acid oxidation. PMID:26240137

  11. Proteomic analysis reveals metabolic and regulatory systems involved in the syntrophic and axenic lifestyle of Syntrophomonas wolfei

    SciTech Connect

    Sieber, Jessica R.; Crable, Bryan R.; Sheik, Cody S.; Hurst, Gregory B.; Rohlin, Lars; Gunsalus, Robert P.; McInerney, Michael J.

    2015-02-11

    We report that microbial syntrophy is a vital metabolic interaction necessary for the complete oxidation of organic biomass to methane in all-anaerobic ecosystems. However, this process is thermodynamically constrained and represents an ecosystem-level metabolic bottleneck. To gain insight into the physiology of this process, a shotgun proteomics approach was used to quantify the protein landscape of the model syntrophic metabolizer, Syntrophomonas wolfei, grown axenically and syntrophically with Methanospirillum hungatei. Remarkably, the abundance of most proteins as represented by normalized spectral abundance factor (NSAF) value changed very little between the pure and coculture growth conditions. Among the most abundant proteins detected were GroEL and GroES chaperonins, a small heat shock protein, and proteins involved in electron transfer, beta-oxidation, and ATP synthesis. Several putative energy conservation enzyme systems that utilize NADH and ferredoxin were present. The abundance of an EtfAB2 and the membrane-bound iron-sulfur oxidoreductase (Swol_0698 gene product) delineated a potential conduit for electron transfer between acyl-CoA dehydrogenases and membrane redox carriers. Proteins detected only when S. wolfei was grown with M. hungatei included a zinc-dependent dehydrogenase with a GroES domain, whose gene is present in genomes in many organisms capable of syntrophy, and transcriptional regulators responsive to environmental stimuli or the physiological status of the cell. In conclusion, the proteomic analysis revealed an emphasis on macromolecular stability and energy metabolism by S. wolfei and presence of regulatory mechanisms responsive to external stimuli and cellular physiological status.

  12. Proteomic analysis reveals metabolic and regulatory systems involved in the syntrophic and axenic lifestyle of Syntrophomonas wolfei

    PubMed Central

    Sieber, Jessica R.; Crable, Bryan R.; Sheik, Cody S.; Hurst, Gregory B.; Rohlin, Lars; Gunsalus, Robert P.; McInerney, Michael J.

    2015-01-01

    Microbial syntrophy is a vital metabolic interaction necessary for the complete oxidation of organic biomass to methane in all-anaerobic ecosystems. However, this process is thermodynamically constrained and represents an ecosystem-level metabolic bottleneck. To gain insight into the physiology of this process, a shotgun proteomics approach was used to quantify the protein landscape of the model syntrophic metabolizer, Syntrophomonas wolfei, grown axenically and syntrophically with Methanospirillum hungatei. Remarkably, the abundance of most proteins as represented by normalized spectral abundance factor (NSAF) value changed very little between the pure and coculture growth conditions. Among the most abundant proteins detected were GroEL and GroES chaperonins, a small heat shock protein, and proteins involved in electron transfer, beta-oxidation, and ATP synthesis. Several putative energy conservation enzyme systems that utilize NADH and ferredoxin were present. The abundance of an EtfAB2 and the membrane-bound iron-sulfur oxidoreductase (Swol_0698 gene product) delineated a potential conduit for electron transfer between acyl-CoA dehydrogenases and membrane redox carriers. Proteins detected only when S. wolfei was grown with M. hungatei included a zinc-dependent dehydrogenase with a GroES domain, whose gene is present in genomes in many organisms capable of syntrophy, and transcriptional regulators responsive to environmental stimuli or the physiological status of the cell. The proteomic analysis revealed an emphasis on macromolecular stability and energy metabolism by S. wolfei and presence of regulatory mechanisms responsive to external stimuli and cellular physiological status. PMID:25717324

  13. Proteomic analysis reveals metabolic and regulatory systems involved in the syntrophic and axenic lifestyle of Syntrophomonas wolfei

    DOE PAGESBeta

    Sieber, Jessica R.; Crable, Bryan R.; Sheik, Cody S.; Hurst, Gregory B.; Rohlin, Lars; Gunsalus, Robert P.; McInerney, Michael J.

    2015-02-11

    We report that microbial syntrophy is a vital metabolic interaction necessary for the complete oxidation of organic biomass to methane in all-anaerobic ecosystems. However, this process is thermodynamically constrained and represents an ecosystem-level metabolic bottleneck. To gain insight into the physiology of this process, a shotgun proteomics approach was used to quantify the protein landscape of the model syntrophic metabolizer, Syntrophomonas wolfei, grown axenically and syntrophically with Methanospirillum hungatei. Remarkably, the abundance of most proteins as represented by normalized spectral abundance factor (NSAF) value changed very little between the pure and coculture growth conditions. Among the most abundant proteins detectedmore » were GroEL and GroES chaperonins, a small heat shock protein, and proteins involved in electron transfer, beta-oxidation, and ATP synthesis. Several putative energy conservation enzyme systems that utilize NADH and ferredoxin were present. The abundance of an EtfAB2 and the membrane-bound iron-sulfur oxidoreductase (Swol_0698 gene product) delineated a potential conduit for electron transfer between acyl-CoA dehydrogenases and membrane redox carriers. Proteins detected only when S. wolfei was grown with M. hungatei included a zinc-dependent dehydrogenase with a GroES domain, whose gene is present in genomes in many organisms capable of syntrophy, and transcriptional regulators responsive to environmental stimuli or the physiological status of the cell. In conclusion, the proteomic analysis revealed an emphasis on macromolecular stability and energy metabolism by S. wolfei and presence of regulatory mechanisms responsive to external stimuli and cellular physiological status.« less

  14. The Role of Long Chain Fatty Acids and Their Epoxide Metabolites in Nociceptive Signaling

    PubMed Central

    Wagner, Karen; Vito, Steve; Inceoglu, Bora; Hammock, Bruce D.

    2014-01-01

    Lipid derived mediators contribute to inflammation and the sensing of pain. The contributions of omega-6 derived prostanoids in enhancing inflammation and pain sensation are well known. Less well explored are the opposing anti-inflammatory and analgesic effects of the omega-6 derived epoxyeicosatrienoic acids. Far less has been described about the epoxidized metabolites derived from omega-3 long chain fatty acids. The epoxide metabolites are turned over rapidly with enzymatic hydrolysis by the soluble epoxide hydrolase being the major elimination pathway. Despite this, the overall understanding of the role of lipid mediators in the pathology of chronic pain is growing. Here we review the role of long chain fatty acids and their metabolites in alleviating both acute and chronic pain conditions. We focus specifically on the epoxidized metabolites of omega-6 and omega-3 long chain fatty acids as well as a novel strategy to modulate their activity in vivo. PMID:25240260

  15. Toxicants inhibiting anaerobic digestion: a review.

    PubMed

    Chen, Jian Lin; Ortiz, Raphael; Steele, Terry W J; Stuckey, David C

    2014-12-01

    Anaerobic digestion is increasingly being used to treat wastes from many sources because of its manifold advantages over aerobic treatment, e.g. low sludge production and low energy requirements. However, anaerobic digestion is sensitive to toxicants, and a wide range of compounds can inhibit the process and cause upset or failure. Substantial research has been carried out over the years to identify specific inhibitors/toxicants, and their mechanism of toxicity in anaerobic digestion. In this review we present a detailed and critical summary of research on the inhibition of anaerobic processes by specific organic toxicants (e.g., chlorophenols, halogenated aliphatics and long chain fatty acids), inorganic toxicants (e.g., ammonia, sulfide and heavy metals) and in particular, nanomaterials, focusing on the mechanism of their inhibition/toxicity. A better understanding of the fundamental mechanisms behind inhibition/toxicity will enhance the wider application of anaerobic digestion. PMID:25457225

  16. Biostimulation induces syntrophic interactions that impact C, S and N cycling in a sediment microbial community

    SciTech Connect

    Handley, KM; Verberkmoes, Nathan C; Steefel, Carl I; Sharon, I; Williams, Ken; Miller, CS; Frischkorn, Kyle C; Chourey, Karuna; Thomas, Brian; Shah, Manesh B; Long, Phil; Hettich, Robert {Bob} L; Banfield, Jillian F.

    2013-01-01

    Stimulation of subsurface microorganisms to induce reductive immobilization of metals is a promising approach for bioremediation, yet the overall microbial community response is typically poorly understood. Here we used community proteogenomics to test the hypothesis that excess input of acetate activates syntrophic interactions among autotrophs and heterotrophs. A flow-through sediment column was incubated in a groundwater well of an acetate-amended aquifer. Genomic sequences from the community recovered during microbial sulfate reduction were used to econstruct, de novo, near-complete genomes for Desulfobacter (Deltaproteobacteria) and relatives of Sulfurovum and Sulfurimonas (Epsilonproteobacteria), and Bacteroidetes. Partial genomes were obtained for Clostridiales (Firmicutes) and Desulfuromonadales-like Deltaproteobacteria. The majority of proteins identified by mass spectrometry corresponded to Desulfobacter-like species, and demonstrate the role of this organism in sulfate reduction (Dsr and APS), nitrogen-fixation (Nif) and acetate oxidation to CO2 during amendment. Results suggest less abundant Desulfuromonadales and Bacteroidetes also actively contributed to CO2 production via the TCA cycle. Proteomic data indicate that sulfide was partially re-oxidized by Epsilonproteobacteria through nitrate-dependent sulfide oxidation (using Nap, Nir, Nos, SQR and Sox), with CO2 fixed using the reverse TCA cycle. Modeling shows that this reaction was thermodynamically possible, and kinetically favorable relative to acetate-dependent denitrification. We conclude that high-levels of carbon amendment aimed to stimulate anaerobic heterotrophy led to carbon fixation in co-dependent chemoautotrophs. These results have implications for understanding complex ecosystem behavior, and show that high levels of organic carbon supplementation can expand the range of microbial functionalities accessible for ecosystem manipulation.

  17. The Thermotoga maritima Phenotype Is Impacted by Syntrophic Interaction with Methanococcus jannaschii in Hyperthermophilic Coculture†

    PubMed Central

    Johnson, M. R.; Conners, S. B.; Montero, C. I.; Chou, C. J.; Shockley, K. R.; Kelly, R. M.

    2006-01-01

    Significant growth phase-dependent differences were noted in the transcriptome of the hyperthermophilic bacterium Thermotoga maritima when it was cocultured with the hyperthermophilic archaeon Methanococcus jannaschii. For the mid-log-to-early-stationary-phase transition of a T. maritima monoculture, 24 genes (1.3% of the genome) were differentially expressed twofold or more. In contrast, methanogenic coculture gave rise to 292 genes differentially expressed in T. maritima at this level (15.5% of the genome) for the same growth phase transition. Interspecies H2 transfer resulted in three- to fivefold-higher T. maritima cell densities than in the monoculture, with concomitant formation of exopolysaccharide (EPS)-based cell aggregates. Differential expression of specific sigma factors and genes related to the ppGpp-dependent stringent response suggests involvement in the transition into stationary phase and aggregate formation. Cell aggregation was growth phase dependent, such that it was most prominent during mid-log phase and decayed as cells entered stationary phase. The reduction in cell aggregation was coincidental with down-regulation of genes encoding EPS-forming glycosyltranferases and up-regulation of genes encoding β-specific glycosyl hydrolases; the latter were presumably involved in hydrolysis of β-linked EPS to release cells from aggregates. Detachment of aggregates may facilitate colonization of new locations in natural environments where T. maritima coexists with other organisms. Taken together, these results demonstrate that syntrophic interactions can impact the transcriptome of heterotrophs in methanogenic coculture, and this factor should be considered in examining the microbial ecology in anaerobic environments. PMID:16391122

  18. Cardiac Hypertrophy in Mice with Long-Chain Acyl-CoA Dehydrogenase (LCAD) or Very Long-Chain Acyl-CoA Dehydrogenase (VLCAD) Deficiency

    PubMed Central

    Cox, Keith B.; Liu, Jian; Tian, Liqun; Barnes, Stephen; Yang, Qinglin; Wood, Philip A.

    2009-01-01

    Cardiac hypertrophy is a common finding in human patients with inborn errors of long-chain fatty acid oxidation. Mice with either very long-chain acyl-CoA dehydrogenase deficiency (VLCAD−/−) or long-chain acyl-CoA dehydrogenase deficiency (LCAD−/−) develop cardiac hypertrophy. Cardiac hypertrophy, initially measured using heart/body weight ratios, was manifested most severely in LCAD−/− male mice. VLCAD−/− mice, as a group, showed a mild increase in normalized cardiac mass (8.8% hypertrophy compared to all wild-type [WT] mice). In contrast, LCAD−/− mice as a group showed more severe cardiac hypertrophy (32.2% increase compared to all WT mice). Based on a clear male predilection, we investigated the role of dietary plant estrogenic compounds commonly found in mouse diets due to soy or alfalfa components providing natural phytoestrogens or isoflavones in cardioprotection of LCAD−/− mice. Male LCAD−/− mice fed an isoflavone-free test diet had more severe cardiac hypertrophy (58.1% hypertrophy compared to WT mice fed the same diet. There were no significant differences in the female groups fed any of the diets. Echocardiography measurement performed on male LCAD deficient mice fed a standard diet at ~3 months of age confirmed the substantial cardiac hypertrophy in these mice compared with WT controls. Left ventricular wall thickness of interventricular septum and posterior wall was remarkably increased in LCAD−/− mice compared with that of WT controls. Accordingly, the calculated LV mass after normalization to body weight was increased about 40% in the LCAD−/− mice compared with WT mice. In summary, we found that metabolic cardiomyopathy, expressed as hypertrophy, developed in mice due to either VLCAD deficiency or LCAD deficiency; however, LCAD deficiency was the most profound and appeared to be attenuated either by endogenous estrogen in females or phytoestrogens in the diet as isoflavones in males. PMID:19736549

  19. 21 CFR 178.3780 - Polyhydric alcohol esters of long chain monobasic acids.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Polyhydric alcohol esters of long chain monobasic acids. 178.3780 Section 178.3780 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: ADJUVANTS, PRODUCTION AIDS, AND SANITIZERS...

  20. 21 CFR 178.3780 - Polyhydric alcohol esters of long chain monobasic acids.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Polyhydric alcohol esters of long chain monobasic acids. 178.3780 Section 178.3780 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: ADJUVANTS, PRODUCTION AIDS, AND SANITIZERS...

  1. 21 CFR 178.3780 - Polyhydric alcohol esters of long chain monobasic acids.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyhydric alcohol esters of long chain monobasic acids. 178.3780 Section 178.3780 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: ADJUVANTS, PRODUCTION AIDS, AND SANITIZERS...

  2. 21 CFR 178.3780 - Polyhydric alcohol esters of long chain monobasic acids.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Polyhydric alcohol esters of long chain monobasic acids. 178.3780 Section 178.3780 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: ADJUVANTS, PRODUCTION AIDS, AND SANITIZERS...

  3. Long-chain n-3 fatty acids - New anabolic compounds improving protein metabolism

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previous animal studies demonstrated that chronic feeding of long-chain n-3 polyunsaturated fatty acids (LCn-3PUFA) that modifies muscle membrane fatty acid composition promotes protein anabolism by blunting the age-associated deterioration in insulin sensitivity. The current study assessed, as a pr...

  4. Treatment recommendations in long-chain fatty acid oxidation defects: consensus from a workshop.

    PubMed

    Spiekerkoetter, U; Lindner, M; Santer, R; Grotzke, M; Baumgartner, M R; Boehles, H; Das, A; Haase, C; Hennermann, J B; Karall, D; de Klerk, H; Knerr, I; Koch, H G; Plecko, B; Röschinger, W; Schwab, K O; Scheible, D; Wijburg, F A; Zschocke, J; Mayatepek, E; Wendel, U

    2009-08-01

    Published data on treatment of fatty acid oxidation defects are scarce. Treatment recommendations have been developed on the basis of observations in 75 patients with long-chain fatty acid oxidation defects from 18 metabolic centres in Central Europe. Recommendations are based on expert practice and are suggested to be the basis for further multicentre prospective studies and the development of approved treatment guidelines. Considering that disease complications and prognosis differ between different disorders of long-chain fatty acid oxidation and also depend on the severity of the underlying enzyme deficiency, treatment recommendations have to be disease-specific and depend on individual disease severity. Disorders of the mitochondrial trifunctional protein are associated with the most severe clinical picture and require a strict fat-reduced and fat-modified (medium-chain triglyceride-supplemented) diet. Many patients still suffer acute life-threatening events or long-term neuropathic symptoms despite adequate treatment, and newborn screening has not significantly changed the prognosis for these severe phenotypes. Very long-chain acyl-CoA dehydrogenase deficiency recognized in neonatal screening, in contrast, frequently has a less severe disease course and dietary restrictions in many patients may be loosened. On the basis of the collected data, recommendations are given with regard to the fat and carbohydrate content of the diet, the maximal length of fasting periods and the use of l-carnitine in long-chain fatty acid oxidation defects. PMID:19452263

  5. 77 FR 48924 - Perfluoroalkyl Sulfonates and Long-Chain Perfluoroalkyl Carboxylate Chemical Substances; Proposed...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-15

    ... 10, 2006 (71 FR 12311) (FRL-7740-6) (Ref. 17), and also refer to December 30, 2009 Long-Chain... substances? On October 18, 2000, EPA published in the Federal Register a proposed SNUR (65 FR 62319) (FRL... final rule was published in the Federal Register on March 11, 2002 (67 FR 11008) (FRL-6823-6), for...

  6. Long-chain polyunsaturated fatty acids in chronic childhood disorders: panacea, promising, or placebo

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Long-chain polyunsaturated fatty acids (LCPUFA, or LCP) include the essential fatty acids alpha-linolenic acid (ALA, 18:3 n-3) and linoleic acid (LA, 18:2 n-6) as well as a number of metabolites of both, including eicosapentaenoic acid (EPA, 20:5n-3), docosahexaenoic acid (DHA, 22:6n-3), and arachid...

  7. Clerodane diterpenoids, long chain esters of coumaric acid and other compounds from Baccharis myrsinites.

    PubMed

    Li, C J; Ahmed, A A; Arias, A C; Mabry, T J

    1997-06-01

    A new clerodane diterpenoid and two new long chain esters of trans- and cis-coumaric acid, in addition to known triterpenoids and one known clerodane diterpenoid, have been isolated and characterized from Baccharis myrsinites. The structures were determined by spectroscopic techniques. PMID:9190087

  8. LIPID CLASS DISTRIBUTION OF HIGHLY UNSATURATED LONG CHAIN FATTY ACIDS IN MARINE DINOFLAGELLATES.

    EPA Science Inventory

    The very long chain highly unsaturated C28 fatty acids, octacosaheptaenoic [28:7(n-6)] and octacosaoctaenoic acid [28:8(n-3)], were found to be associated with phospholipids, obtained by fractionation of total lipid extracts into distinct lipid classes, in 4 and 6, respectively, ...

  9. Long-chain Diols as a Lacustrine Paleothermometer: Calibration, Caveats, and Future Possibilities

    NASA Astrophysics Data System (ADS)

    Phelps, S. R.; Russell, J. M.; Loomis, S. E.

    2013-12-01

    The fractional abundances of long-chain alkyl 1,13-, 1,14-, and 1,15-diols and the long-chain diol index (LDI) are a novel and promising tool for marine paleotemperature reconstructions. However, little is known about the precise organismal source of these compounds or the efficacy of this paleotemperature proxy in lacustrine environments. Here we analyzed the distribution of long-chain diols in surface-sediment samples from 38 East African lakes and compare them to climatic and limnological parameters, including mean annual air temperature (MAAT), lake water conductivity, pH, nutrient content, and morphometry. Fractional abundances of C32 1,15-diols showed the strongest correlation with MAAT across the entire dataset. Strong correlations were also found between individual diol fractional abundances and pH and phosphorus, but correlation between the LDI and temperature was low (r2 = 0.193, p = 0.012). We used stepwise forward selection (SFS) to develop a multivariate linear regression between the fractional abundances of a combination of long-chain diols and MAAT (r2 = 0.8, p < 0.001). Application of the LDI as well as this new temperature calibration to a sediment core from Lake Tanganyika indicate a cooling of 4°C from LGM to present, suggesting that long-chain diols may not provide accurate temperature reconstructions in large, warm, tropical lakes. However, by splitting the dataset into 'cold' and 'warm' lakes and developing SFS regressions for these lake subsets, we found a strong linear correlation between diol relative abundances and temperature in the 'cold' lakes subset, suggesting diols may be a valuable temperature proxy in cold, high elevation tropical lakes.

  10. Assessment of hydrogen metabolism in commercial anaerobic digesters.

    PubMed

    Kern, Tobias; Theiss, Juliane; Röske, Kerstin; Rother, Michael

    2016-05-01

    Degradation of biomass in the absence of exogenous electron acceptors via anaerobic digestion involves a syntrophic association of a plethora of anaerobic microorganisms. The commercial application of this process is the large-scale production of biogas from renewable feedstock as an alternative to fossil fuels. After hydrolysis of polymers, monomers are fermented to short-chain fatty acids and alcohols, which are further oxidized to acetate. Carbon dioxide, molecular hydrogen (H2), and acetate generated during the process are converted to methane by methanogenic archaea. Since many of the metabolic pathways as well as the syntrophic interactions and dependencies during anaerobic digestion involve formation, utilization, or transfer of H2, its metabolism and the methanogenic population were assessed in various samples from three commercial biogas plants. Addition of H2 significantly increased the rate of methane formation, which suggested that hydrogenotrophic methanogenesis is not a rate-limiting step during biogas formation. Methanoculleus and Methanosarcina appeared to numerically dominate the archaeal population of the three digesters, but their proportion and the Bacteria-to-Archaea ratio did not correlate with the methane productivity. Instead, hydrogenase activity in cell-free extracts from digester sludge correlated with methane productivity in a positive fashion. Since most microorganisms involved in biogas formation contain this activity, it approximates the overall anaerobic metabolic activity and may, thus, be suitable for monitoring biogas reactor performance. PMID:26995607

  11. Ecoengineering high rate anaerobic digestion systems: analysis of improved syntrophic biomethanation catalysts.

    PubMed

    Thiele, J H; Wu, W M; Jain, M K; Zeikus, J G

    1990-04-25

    High performance biomethanation granules with operational specific COD removal rates of 7 kg COD removed/kg SS/d were obtained by ecoengineering conventional, granular, UASB digester sludge using a designed protocol of starvation and selection on a defined volatile fatty acid (VFA) based mineral medium. Addition of low (0.15 mM) sulfate levels to this VFA medium increased the maximum shock-load COD removal rate of the ecoengineered biomethanation granules to 9 kg COD/kg SS/d with specific acetate, propionate, and butyrate removal rates of 111, 28, and 64 mol/g SS/d. Addition of moderate (26 mM) calcium levels inhibited growth and altered the structure of granules. The general cellular, growth, stability, and performance features of these ecoengineered granules are described and discussed in relation to their use as improved biomethanation starter cultures. PMID:18588244

  12. Differential cytotoxicity of long-chain bases for human oral gingival epithelial keratinocytes, oral fibroblasts, and dendritic cells.

    PubMed

    Mehalick, Leslie A; Poulsen, Christopher; Fischer, Carol L; Lanzel, Emily A; Bates, Amber M; Walters, Katherine S; Cavanaugh, Joseph E; Guthmiller, Janet M; Johnson, Georgia K; Wertz, Philip W; Brogden, Kim A

    2015-12-01

    Long-chain bases, found in the oral cavity, have potent antimicrobial activity against oral pathogens. In an article associated with this dataset, Poulson and colleagues determined the cytotoxicities of long-chain bases (sphingosine, dihydrosphingosine, and phytosphingosine) for human oral gingival epithelial (GE) keratinocytes, oral gingival fibroblasts (GF), dendritic cells (DC), and squamous cell carcinoma (SCC) cell lines [1]. Poulson and colleagues found that GE keratinocytes were more resistant to long-chain bases as compared to GF, DC, and SCC cell lines [1]. In this study, we assess the susceptibility of DC to lower concentrations of long chain bases. 0.2-10.0 µM long-chain bases and GML were not cytotoxic to DC; 40.0-80.0 µM long-chain bases, but not GML, were cytotoxic for DC; and 80.0 µM long-chain bases were cytotoxic to DC and induced cellular damage and death in less than 20 mins. Overall, the LD50 of long-chain bases for GE keratinocytes, GF, and DC were considerably higher than their minimal inhibitory concentrations for oral pathogens, a finding important to pursuing their future potential in treating periodontal and oral infections. PMID:26550599

  13. Cracking of long-chain alkyl aromatics on USY zeolite catalysts

    SciTech Connect

    Corma, A. ); Miguel, P.J.; Orchilles, A.V. ); Koermer, G.S. )

    1992-05-01

    Long-chain alkyl aromatics are important precursors for FCC gasoline. It is well known that for short-chain alkyl aromatics like cumene the dominant cracking process is simple alkyl aryl cleavage. In contrast the authors have found that for long-chain alkyl aromatics like 1-phenylheptane, cracking over in situ USY catalysts is much more complex. Cracking in a long alkyl side chain results in a carbenium ion that isomerizes easily and gives self-alkylation of the aromatic ring. Self-alkylation produces coke precursors and heavy gasoline aromatics. Product selectivities vary with zeolite unit cell size in ways that are rationalized on the basis of decreasing acid site density and zeolite adsorption properties.

  14. Long Chain N-acyl Homoserine Lactone Production by Enterobacter sp. Isolated from Human Tongue Surfaces

    PubMed Central

    Yin, Wai-Fong; Purmal, Kathiravan; Chin, Shenyang; Chan, Xin-Yue; Chan, Kok-Gan

    2012-01-01

    We report the isolation of N-acyl homoserine lactone-producing Enterobacter sp. isolate T1-1 from the posterior dorsal surfaces of the tongue of a healthy individual. Spent supernatants extract from Enterobacter sp. isolate T1-1 activated the biosensor Agrobacterium tumefaciens NTL4(pZLR4), suggesting production of long chain AHLs by these isolates. High resolution mass spectrometry analysis of these extracts confirmed that Enterobacter sp. isolate T1-1 produced a long chain N-acyl homoserine lactone, namely N-dodecanoyl-homoserine lactone (C12-HSL). To the best of our knowledge, this is the first isolation of Enterobacter sp., strain T1-1 from the posterior dorsal surface of the human tongue and N-acyl homoserine lactones production by this bacterium. PMID:23202161

  15. Synthesis, characterization and comparative evaluation of phenoxy ring containing long chain gemini imidazolium and pyridinium amphiphiles.

    PubMed

    Bhadani, Avinash; Kataria, Hardeep; Singh, Sukhprit

    2011-09-01

    Two series of phenoxy ring containing long chain imidazolium and pyridinium based gemini amphiphiles have been synthesized from renewable cardanol oil having different spacers (i. e. -S-(CH(2))(n)-S-, where n is 2, 3, 4 & 6). Critical micelle concentration (cmc) of these new gemini amphiphiles has been determined by conductivity method. Further, these new cationic amphiphiles have been evaluated for their DNA binding capability by agarose gel electrophoresis, ethidium bromide exclusion experiments and transmission electron microscopy (TEM). The cytotoxicity of these new amphiphiles have been evaluated by MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Comparative studies of these phenoxy ring containing long chain gemini imidazolium amphiphiles and their pyridinium analogues depicted low cmc values of the later but greater DNA interaction capability and low cytotoxicity of the former series of amphiphiles. PMID:21676409

  16. Long-chain polynucleotide filler for skin rejuvenation: efficacy and complications in five patients.

    PubMed

    Park, Kui Young; Seok, Joon; Rho, Nark Kyoung; Kim, Beom Joon; Kim, Myeung Nam

    2016-01-01

    Aging well has become the new target of preventative medicine, and aesthetic dermatology can contribute to this request. The polynucleotide (PN) containing products not only fill the space, but improve tissue regeneration, resulting in more natural tissue regeneration. Five Korean women received four times injections of long-chain PN filler in two-week intervals for skin rejuvenation. About 0.05 mL of material was injected in 40 points of one-side cheek. The pore and skin thickness were markedly improved in the patients in their 30s, whereas skin tone, melanin, wrinkles, and sagging were noticeably improved for patients in their 40s. There are no serious side effects. In conclusion, intradermal long-chain PN filler injection seems to be an effective and safe treatment for skin rejuvenation. PMID:26814448

  17. Anaerobic bioprocessing of organic wastes.

    PubMed

    Verstraete, W; de Beer, D; Pena, M; Lettinga, G; Lens, P

    1996-05-01

    Anaerobic digestion of dissolved, suspended and solid organics has rapidly evolved in the last decades but nevertheless still faces several scientific unknowns. In this review, some fundamentals of bacterial conversions and adhesion are addressed initially. It is argued in the light of ΔG-values of reactions, and in view of the minimum energy quantum per mol, that anaerobic syntrophs must have special survival strategies in order to support their existence: redistributing the available energy between the partners, reduced end-product fermentation reactions and special cell-to-cell physiological interactions. In terms of kinetics, it appears that both reaction rates and residual substrate thresholds are strongly related to minimum ΔG-values. These new fundamental insights open perspectives for efficient design and operation of anaerobic bioprocesses. Subsequently, an overview is given of the current anaerobic biotechnology. For treating wastewaters, a novel and high performance new system has been introduced during the last decade; the upflow anaerobic sludge blanket system (UASB). This reactor concept requires anaerobic consortia to grow in a dense and eco-physiologically well-organized way. The microbial principles of such granular sludge growth are presented. Using a thermodynamic approach, the formation of different types of aggregates is explained. The application of this bioprocess in worldwide wastewater treatment is indicated. Due to the long retention times of the active biomass, the UASB is also suitable for the development of bacterial consortia capable of degrading xenobiotics. Operating granular sludge reactors at high upflow velocities (5-6 m/h) in expanded granular sludge bed (EGSB) systems enlarges the application field to very low strength wastewaters (chemical oxygen demand < 1 g/l) and psychrophilic temperatures (10°C). For the treatment of organic suspensions, there is currently a tendency to evolve from the conventional mesophilic

  18. Serum long-chain omega-3 polyunsaturated fatty acids and risk of orthostatic hypotension.

    PubMed

    Nyantika, Asenath N; Tuomainen, Tomi-Pekka; Kauhanen, Jussi; Voutilainen, Sari; Virtanen, Jyrki K

    2016-07-01

    Long-chain omega-3 polyunsaturated fatty acids (PUFAs) from fish have been shown to lower blood pressure. However, there is little information about the association with orthostatic hypotension, for which hypertension is a risk factor. We investigated the associations between serum long-chain omega-3 PUFAs and orthostatic hypotension in 1666 middle-aged or older men and women free of cardiovascular disease (CVD), diabetes or hypertension in 1998-2001 in the Kuopio Ischemic Heart Disease Risk Factor Study (KIHD) in eastern Finland. We also investigated the associations with mercury exposure, a major source of which is fish, and which has been associated with higher CVD risk in KIHD. Orthostatic hypotension was defined as decrease in systolic blood pressure of at least 20 mm Hg or diastolic blood pressure of at least 10 mm Hg within 1 min of standing. Orthostatic hypotension was found in 146 participants (8.8%). The mean serum concentrations were 1.67% (s.d. 0.92) for eicosapentaenoic acid, 0.79% (s.d. 0.16) for docosapentaenoic acid (DPA) and 2.78 (s.d. 0.92) for docosahexaenoic acid of all serum fatty acids. The mean pubic hair mercury concentration was 1.5 μg g(-1) (s.d. 1.6). We did not find statistically significant associations between the serum long-chain omega-3 PUFAs or pubic hair mercury and risk of orthostatic hypotension, except for DPA. Those in the highest vs. the lowest serum DPA tertile had multivariate-adjusted 41% lower odds for orthostatic hypotension (95% confidence interval 7-63%, P-trend=0.02). Serum long-chain omega-3 PUFAs or mercury exposure were not associated with the risk of orthostatic hypotension, except for the inverse association with DPA. PMID:26911234

  19. Genes involved in long-chain alkene biosynthesis in Micrococcus luteus

    SciTech Connect

    Beller, Harry R.; Goh, Ee-Been; Keasling, Jay D.

    2010-01-07

    Aliphatic hydrocarbons are highly appealing targets for advanced cellulosic biofuels, as they are already predominant components of petroleum-based gasoline and diesel fuels. We have studied alkene biosynthesis in Micrococcus luteus ATCC 4698, a close relative of Sarcina lutea (now Kocuria rhizophila), which four decades ago was reported to biosynthesize iso- and anteiso branched, long-chain alkenes. The underlying biochemistry and genetics of alkene biosynthesis were not elucidated in those studies. We show here that heterologous expression of a three-gene cluster from M. luteus (Mlut_13230-13250) in a fatty-acid overproducing E. coli strain resulted in production of long-chain alkenes, predominantly 27:3 and 29:3 (no. carbon atoms: no. C=C bonds). Heterologous expression of Mlut_13230 (oleA) alone produced no long-chain alkenes but unsaturated aliphatic monoketones, predominantly 27:2, and in vitro studies with the purified Mlut_13230 protein and tetradecanoyl-CoA produced the same C27 monoketone. Gas chromatography-time of flight mass spectrometry confirmed the elemental composition of all detected long-chain alkenes and monoketones (putative intermediates of alkene biosynthesis). Negative controls demonstrated that the M. luteus genes were responsible for production of these metabolites. Studies with wild-type M. luteus showed that the transcript copy number of Mlut_13230-13250 and the concentrations of 29:1 alkene isomers (the dominant alkenes produced by this strain) generally corresponded with bacterial population over time. We propose a metabolic pathway for alkene biosynthesis starting with acyl-CoA (or -ACP) thioesters and involving decarboxylative Claisen condensation as a key step, which we believe is catalyzed by OleA. Such activity is consistent with our data and with the homology (including the conserved Cys-His-Asn catalytic triad) of Mlut_13230 (OleA) to FabH (?-ketoacyl-ACP synthase III), which catalyzes decarboxylative Claisen condensation during

  20. Long-chain acylcarnitines determine ischaemia/reperfusion-induced damage in heart mitochondria.

    PubMed

    Liepinsh, Edgars; Makrecka-Kuka, Marina; Volska, Kristine; Kuka, Janis; Makarova, Elina; Antone, Unigunde; Sevostjanovs, Eduards; Vilskersts, Reinis; Strods, Arnis; Tars, Kaspars; Dambrova, Maija

    2016-05-01

    The accumulation of long-chain fatty acids (FAs) and their CoA and carnitine esters is observed in the ischaemic myocardium after acute ischaemia/reperfusion. The aim of the present study was to identify harmful FA intermediates and their detrimental mechanisms of action in mitochondria and the ischaemic myocardium. In the present study, we found that the long-chain acyl-CoA and acylcarnitine content is increased in mitochondria isolated from an ischaemic area of the myocardium. In analysing the FA derivative content, we discovered that long-chain acylcarnitines, but not acyl-CoAs, accumulate at concentrations that are harmful to mitochondria. Acylcarnitine accumulation in the mitochondrial intermembrane space is a result of increased carnitine palmitoyltransferase 1 (CPT1) and decreased carnitine palmitoyltransferase 2 (CPT2) activity in ischaemic myocardium and it leads to inhibition of oxidative phosphorylation, which in turn induces mitochondrial membrane hyperpolarization and stimulates the production of reactive oxygen species (ROS) in cardiac mitochondria. Thanks to protection mediated by acyl-CoA-binding protein (ACBP), the heart is much better guarded against the damaging effects of acyl-CoAs than against acylcarnitines. Supplementation of perfusion buffer with palmitoylcarnitine (PC) before occlusion resulted in a 2-fold increase in the acylcarnitine content of the heart and increased the infarct size (IS) by 33%. A pharmacologically induced decrease in the mitochondrial acylcarnitine content reduced the IS by 44%. Long-chain acylcarnitines are harmful FA intermediates, accumulating in ischaemic heart mitochondria and inducing inhibition of oxidative phosphorylation. Therefore, decreasing the acylcarnitine content via cardioprotective drugs may represent a novel treatment strategy. PMID:26936967

  1. Measuring long chain alkanes in diesel engine exhaust by thermal desorption PTR-MS

    NASA Astrophysics Data System (ADS)

    Erickson, M. H.; Gueneron, M.; Jobson, B. T.

    2014-01-01

    A method using thermal desorption sampling and analysis by proton transfer reaction mass spectrometry (PTR-MS) to measure long chain alkanes (C12-C18) and other larger organics associated with diesel engine exhaust emissions is described. Long chain alkanes undergo dissociative proton transfer reactions forming a series of fragment ions with formula CnH2n+1. The PTR-MS is insensitive to n-alkanes less than C8 but displays an increasing sensitivity for larger alkanes. Fragment ion distribution and sensitivity is a function of drift conditions. At 80 Td the most abundant ion fragments from C10 to C16 n-alkanes were m/z 57, 71 and 85. The mass spectrum of gasoline and diesel fuel at 80 Td displayed ion group patterns that can be related to known fuel constituents, such as alkanes, alkylbenzenes and cycloalkanes, and other compound groups that are inferred from molecular weight distributions such as dihydronapthalenes and naphthenic monoaromatics. It is shown that thermal desorption sampling of gasoline and diesel engine exhausts at 80 Td allows for discrimination against volatile organic compounds, allowing for quantification of long chain alkanes from the abundance of CnH2n+1 fragment ions. The total abundance of long chain alkanes in diesel engine exhaust was measured to be similar to the total abundance of C1-C4 alkylbenzene compounds. The abundance patterns of compounds determined by thermal desorption sampling may allow for emission profiles to be developed to better quantify the relative contributions of diesel and gasoline exhaust emissions on organic compounds concentrations in urban air.

  2. The Influence of Shear Thinning on Elongation Hardening of Long-Chain Branched Polypropylene

    NASA Astrophysics Data System (ADS)

    Breuer, Gerold; Schausberger, Alois

    2008-07-01

    Long-chain branched polypropylenes show pronounced strain hardening in elongation. This property, important for various applications is strongly reduced by shear applied to the melt before elongation. In this work the influence of shear history on the rheological properties of blends from a linear (L-PP) and a long-chain branched (LCB-PP) polypropylene was studied in detail. Shear thinning is produced in a cone-plate device and the annealing of it is recorded by the storage modulus, G'(ω), immediately after applying the shear deformation. In the case of L-PP this recovery function is simple exponential, whereas additional relaxation processes are found with the presence of LCB-PP in the blend. In order to investigate the elongational behaviour after various shear histories the sheared sample is removed from the cone-plate system, compressed into a flat sheet and quenched very fast to ensure residual shear thinning. Constant elongation rate experiments have been performed using a uniaxial extensional rheometer, the SER universal testing platform where the tensile stress growth coefficient, ηE+(t,ɛ˙0), is recorded. Shear thinning reduces elongation hardening reversible. The annealing of this reduction depends on the shear history and the degree of long chain branching.

  3. Substrate specificity of a long-chain alkylamine-degrading Pseudomonas sp isolated from activated sludge

    PubMed Central

    Louwerse, Annemarie; van der Togt, Bert

    2007-01-01

    A bacterium strain BERT, which utilizes primary long-chain alkylamines as nitrogen, carbon and energy source, was isolated from activated sludge. This rod-shaped motile, Gram-negative strain was identified as a Pseudomonas sp. The substrate spectrum of this Pseudomonas strain BERT includes primary alkylamines with alkyl chains ranging from C3 to C18, and dodecyl-1,3-diaminopropane. Amines with alkyl chains ranging from 8 to 14 carbons were the preferred substrates. Growth on dodecanal, dodecanoic acid and acetic acid and simultaneous adaptation studies indicated that this bacterium initiates degradation through a Calkyl–N cleavage. The cleavage of alkylamines to the respective alkanals in Pseudomonas strain BERT is mediated by a PMS-dependent alkylamine dehydrogenase. This alkylamine dehydrogenase produces stoichiometric amounts of ammonium from octylamine. The PMS-dependent alkylamine was found to oxidize a broad range of long-chain alkylamines. PMS-dependent long-chain aldehyde dehydrogenase activity was also detected in cell-free extract of Pseudomonas strain BERT grown on octylamine. The proposed pathway for the oxidation of alkylamine in strain BERT proceeds from alkylamine to alkanal, and then to the fatty acid. PMID:17492358

  4. Unique plasma metabolomic signatures of individuals with inherited disorders of long-chain fatty acid oxidation.

    PubMed

    McCoin, Colin S; Piccolo, Brian D; Knotts, Trina A; Matern, Dietrich; Vockley, Jerry; Gillingham, Melanie B; Adams, Sean H

    2016-05-01

    Blood and urine acylcarnitine profiles are commonly used to diagnose long-chain fatty acid oxidation disorders (FAOD: i.e., long-chain hydroxy-acyl-CoA dehydrogenase [LCHAD] and carnitine palmitoyltransferase 2 [CPT2] deficiency), but the global metabolic impact of long-chain FAOD has not been reported. We utilized untargeted metabolomics to characterize plasma metabolites in 12 overnight-fasted individuals with FAOD (10 LCHAD, two CPT2) and 11 healthy age-, sex-, and body mass index (BMI)-matched controls, with the caveat that individuals with FAOD consume a low-fat diet supplemented with medium-chain triglycerides (MCT) while matched controls consume a typical American diet. In plasma 832 metabolites were identified, and partial least squared-discriminant analysis (PLS-DA) identified 114 non-acylcarnitine variables that discriminated FAOD subjects and controls. FAOD individuals had significantly higher triglycerides and lower specific phosphatidylethanolamines, ceramides, and sphingomyelins. Differences in phosphatidylcholines were also found but the directionality differed by metabolite species. Further, there were few differences in non-lipid metabolites, indicating the metabolic impact of FAOD specifically on lipid pathways. This analysis provides evidence that LCHAD/CPT2 deficiency significantly alters complex lipid pathway flux. This metabolic signature may provide new clinical tools capable of confirming or diagnosing FAOD, even in subjects with a mild phenotype, and may provide clues regarding the biochemical and metabolic impact of FAOD that is relevant to the etiology of FAOD symptoms. PMID:26907176

  5. Metagenomic Analyses Reveal the Involvement of Syntrophic Consortia in Methanol/Electricity Conversion in Microbial Fuel Cells

    PubMed Central

    Yamamuro, Ayaka; Kouzuma, Atsushi; Abe, Takashi; Watanabe, Kazuya

    2014-01-01

    Methanol is widely used in industrial processes, and as such, is discharged in large quantities in wastewater. Microbial fuel cells (MFCs) have the potential to recover electric energy from organic pollutants in wastewater; however, the use of MFCs to generate electricity from methanol has not been reported. In the present study, we developed single-chamber MFCs that generated electricity from methanol at the maximum power density of 220 mW m−2 (based on the projected area of the anode). In order to reveal how microbes generate electricity from methanol, pyrosequencing of 16S rRNA-gene amplicons and Illumina shotgun sequencing of metagenome were conducted. The pyrosequencing detected in abundance Dysgonomonas, Sporomusa, and Desulfovibrio in the electrolyte and anode and cathode biofilms, while Geobacter was detected only in the anode biofilm. Based on known physiological properties of these bacteria, it is considered that Sporomusa converts methanol into acetate, which is then utilized by Geobacter to generate electricity. This speculation is supported by results of shotgun metagenomics of the anode-biofilm microbes, which reconstructed relevant catabolic pathways in these bacteria. These results suggest that methanol is anaerobically catabolized by syntrophic bacterial consortia with electrodes as electron acceptors. PMID:24852573

  6. Anaerobic bacteria

    MedlinePlus

    Anaerobic bacteria are bacteria that do not live or grow when oxygen is present. In humans, these ... Goldstein EJ. Diseases caused by non-spore forming anaerobic bacteria. In: Goldman L, Schafer AI, eds. Goldman's ...

  7. Performance of anaerobic granules for degradation of pentachlorophenol.

    PubMed Central

    Wu, W M; Bhatnagar, L; Zeikus, J G

    1993-01-01

    Anaerobic granules degrading pentachlorophenol (PCP) with specific PCP removal activity up to 14.6 mg/g of volatile suspended solids per day were developed in a laboratory-scale anaerobic upflow sludge blanket reactor at 28 degrees C, by using a mixture of acetate, propionate, butyrate, and methanol as the carbon source. The reactor was able to treat synthetic wastewater containing 40 to 60 mg of PCP per liter at a volumetric loading rate of up to 90 mg/liter of reactor volume per day, with a hydraulic retention time of 10.8 to 15 h. PCP removal of more than 99% was achieved. Results of adsorption of PCP by granular biomass indicated that the PCP removal by the granules was due to biodegradation rather than adsorption. A radiotracer assay demonstrated that the PCP-degrading granules mineralized [14C]PCP to 14CH4 and 14CO2. Toxicity test results indicated that syntrophic propionate degraders and acetate-utilizing methanogens were more sensitive to PCP than syntrophic butyrate degraders. The PCP-degrading granules also exhibited a higher tolerance to the inhibition caused by PCP for methane production and degradation of acetate, propionate, and butyrate, compared with anaerobic granules unadapted to PCP. PMID:8434908

  8. Syntrophic growth via quinone-mediated interspecies electron transfer

    PubMed Central

    Smith, Jessica A.; Nevin, Kelly P.; Lovley, Derek R.

    2015-01-01

    The mechanisms by which microbial species exchange electrons are of interest because interspecies electron transfer can expand the metabolic capabilities of microbial communities. Previous studies with the humic substance analog anthraquinone-2,6-disulfonate (AQDS) suggested that quinone-mediated interspecies electron transfer (QUIET) is feasible, but it was not determined if sufficient energy is available from QUIET to support the growth of both species. Furthermore, there have been no previous studies on the mechanisms for the oxidation of anthrahydroquinone-2,6-disulfonate (AHQDS). A co-culture of Geobacter metallireducens and G. sulfurreducens metabolized ethanol with the reduction of fumarate much faster in the presence of AQDS, and there was an increase in cell protein. G. sulfurreducens was more abundant, consistent with G. sulfurreducens obtaining electrons from acetate that G. metallireducens produced from ethanol, as well as from AHQDS. Co-cultures initiated with a citrate synthase-deficient strain of G. sulfurreducens that was unable to use acetate as an electron donor also metabolized ethanol with the reduction of fumarate and cell growth, but acetate accumulated over time. G. sulfurreducens and G. metallireducens were equally abundant in these co-cultures reflecting the inability of the citrate synthase-deficient strain of G. sulfurreducens to metabolize acetate. Evaluation of the mechanisms by which G. sulfurreducens accepts electrons from AHQDS demonstrated that a strain deficient in outer-surface c-type cytochromes that are required for AQDS reduction was as effective at QUIET as the wild-type strain. Deletion of additional genes previously implicated in extracellular electron transfer also had no impact on QUIET. These results demonstrate that QUIET can yield sufficient energy to support the growth of both syntrophic partners, but that the mechanisms by which electrons are derived from extracellular hydroquinones require further investigation. PMID

  9. Alkenone temperature and salinity: An evaluation of long chain C37 alkenone in Lake Qinghai, China

    NASA Astrophysics Data System (ADS)

    Liu, W.; Liu, Z.; Fu, M.; An, Z.

    2007-12-01

    In recently years, the alkenone unsaturation index (Uk'37=C37:.2/(C37:2+ C37:3)) has been used to reconstructed paleo-temperature for lacustrine sediments. However, few studies have addressed whether the relative abundance of the C37:4 alkenone to the total C37 production (C37:4 percent) can reflect surface salinity changes in lake systems. Here we present the distribution of C37 long chain alkenone of modern lake sediments in Qinghai Lake, Qing-Tibet Plateau, to evaluate significance of abundance change of long chain C37 alkenone as an indicator of lake paleo-enviromental evolution. A group of surface sediments from different locations in the lake have been analyzed in this study. The results of long chain C37 alkenone from 28 surface sediments analyses shown relative abundance of C37:4 alkenone to total C37 production (C37:4 percent) change from 14.5 to 48.6 percent and the abundance of C37:4 alkenone is increasing with decreasing salinity of lake water. For the salinity lake in land, we suggested the relative abundance of C37:4 alkenone in lake sediments may be a indicator of paleo-silinity; We have also found that Uk'37 values are weakly correlated with salinity and C37:4 percent changes, implying that potential minor contributions of temperature and salinity effects to C37:4 percent and Uk'37 respectively cannot be excluded in this study. However, since these contributions are weak, we suggest that the C37:4 percent proxy can be used to reconstruct paleo-salinity changes at a regional scale, especially in lake systems, while Uk'37 remains as a powerful tool for reconstructions of paleo-temperature changes in the lake systems.

  10. Treatment of Essential Tremor with Long-Chain Alcohols: Still Experimental or Ready for Prime Time?

    PubMed Central

    Haubenberger, Dietrich; Nahab, Fatta B.; Voller, Bernhard; Hallett, Mark

    2014-01-01

    Aim To review current literature on long-chain alcohols and their derivatives as novel pharmacotherapy for the treatment of essential tremor (ET). Background Currently available and recommended pharmacotherapies for ET are often limited by suboptimal treatment effects, frequent adverse effects, and drug interactions. While ethanol is reported to profoundly decrease tremor severity in the majority of patients with ET, preclinical experience suggests that long-chain alcohols such as 1-octanol might lead to a comparable tremor reduction without ethanol’s typical side effects of sedation and intoxication. Here, we review the literature on the first clinical trials on 1-octanol and its metabolite octanoic acid (OA) for the treatment of ET. Methods The literature on preclinical and clinical trials on long-chain alcohols as well as OA was reviewed and summarized, and an outlook given on next phases of development. Discussion 1-octanol was demonstrated to be safe and effective in a double-blind, placebo-controlled low-dose trial, and open-label data showed excellent tolerability and dose-dependent efficacy up to 128 mg/kg. Despite 1-octanol’s efficacy, its future viability as an effective therapy is limited by its pharmacological properties that require large volumes to be orally administered. Pharmacokinetic data indicate that OA is the active metabolite of 1-octanol. Preclinical efficacy data for OA are positive, and human pilot data demonstrated excellent safety as well as efficacy in secondary outcome measures of tremor amplitudes. OA also has more favorable pharmacological properties for drug delivery; hence, OA may be worth developing as a pharmaceutical. PMID:24587968

  11. A Long-Chain Flavodoxin Protects Pseudomonas aeruginosa from Oxidative Stress and Host Bacterial Clearance

    PubMed Central

    Moyano, Alejandro J.; Krapp, Adriana R.; Mondotte, Juan A.; Bocco, José L.; Saleh, Maria-Carla; Carrillo, Néstor; Smania, Andrea M.

    2014-01-01

    Long-chain flavodoxins, ubiquitous electron shuttles containing flavin mononucleotide (FMN) as prosthetic group, play an important protective role against reactive oxygen species (ROS) in various microorganisms. Pseudomonas aeruginosa is an opportunistic pathogen which frequently has to face ROS toxicity in the environment as well as within the host. We identified a single ORF, hereafter referred to as fldP (for flavodoxin from P . aeruginosa), displaying the highest similarity in length, sequence identity and predicted secondary structure with typical long-chain flavodoxins. The gene was cloned and expressed in Escherichia coli. The recombinant product (FldP) could bind FMN and exhibited flavodoxin activity in vitro. Expression of fldP in P. aeruginosa was induced by oxidative stress conditions through an OxyR-independent mechanism, and an fldP-null mutant accumulated higher intracellular ROS levels and exhibited decreased tolerance to H2O2 toxicity compared to wild-type siblings. The mutant phenotype could be complemented by expression of a cyanobacterial flavodoxin. Overexpression of FldP in a mutT-deficient P. aeruginosa strain decreased H2O2-induced cell death and the hypermutability caused by DNA oxidative damage. FldP contributed to the survival of P. aeruginosa within cultured mammalian macrophages and in infected Drosophila melanogaster, which led in turn to accelerated death of the flies. Interestingly, the fldP gene is present in some but not all P. aeruginosa strains, constituting a component of the P. aeruginosa accessory genome. It is located in a genomic island as part of a self-regulated polycistronic operon containing a suite of stress-associated genes. The collected results indicate that the fldP gene encodes a long-chain flavodoxin, which protects the cell from oxidative stress, thereby expanding the capabilities of P. aeruginosa to thrive in hostile environments. PMID:24550745

  12. Relationship between orbital energy gaps and excitation energies for long-chain systems.

    PubMed

    Tsuneda, Takao; Singh, Raman K; Nakata, Ayako

    2016-06-15

    The difference between the excitation energies and corresponding orbital energy gaps, the exciton binding energy, is investigated based on time-dependent (TD) density functional theory (DFT) for long-chain systems: all-trans polyacetylenes and linear oligoacenes. The optimized geometries of these systems indicate that bond length alternations significantly depend on long-range exchange interactions. In TDDFT formalism, the exciton binding energy comes from the two-electron interactions between occupied and unoccupied orbitals through the Coulomb-exchange-correlation integral kernels. TDDFT calculations show that the exciton binding energy is significant when long-range exchange interactions are involved. Spin-flip (SF) TDDFT calculations are then carried out to clarify double-excitation effects in these excitation energies. The calculated SF-TDDFT results indicate that double-excitation effects significantly contribute to the excitations of long-chain systems. The discrepancies between the vertical ionization potential minus electron affinity (IP-EA) values and the HOMO-LUMO excitation energies are also evaluated for the infinitely long polyacetylene and oligoacene using the least-square fits to estimate the exciton binding energy of infinitely long systems. It is found that long-range exchange interactions are required to give the exciton binding energy of the infinitely long systems. Consequently, it is concluded that long-range exchange interactions neglected in many DFT calculations play a crucial role in the exciton binding energies of long-chain systems, while double-excitation correlation effects are also significant to hold the energy balance of the excitations. © 2016 Wiley Periodicals, Inc. PMID:27010365

  13. The intracellular parasite Toxoplasma gondii depends on the synthesis of long chain and very long-chain unsaturated fatty acids not supplied by the host cell

    PubMed Central

    Ramakrishnan, Srinivasan; Docampo, Melissa D.; MacRae, James I.; Ralton, Julie E.; Rupasinghe, Thusitha; McConville, Malcolm J.; Striepen, Boris

    2015-01-01

    SUMMARY Apicomplexa are parasitic protozoa that cause important human diseases including malaria, cryptosporidiosis and toxoplasmosis. The replication of these parasites within their target host cell is dependent on both salvage as well as de novo synthesis of fatty acids. In T. gondii, fatty acid synthesis via the apicoplast-localized FASII is essential for pathogenesis, while the role of two other fatty acid biosynthetic complexes remains unclear. Here we demonstrate that the ER-localized fatty acid elongation (ELO) is essential for parasite growth. Conditional knock-down of the non-redundant hydroxyacyl-CoA dehydratase and enoyl-CoA reductase enzymes in the ELO pathway severely repressed intracellular parasite growth. 13C-glucose and 13C-acetate labeling and comprehensive lipidomic analyses of these mutants showed a selective defect in synthesis of unsaturated long and very long chain fatty acids (LCFAs and VLCFAs) and depletion of phosphatidylinositol and phosphatidylethanolamine species containing unsaturated LCFAs and VLCFAs. This requirement for ELO pathway was by-passed by supplementing the media with specific fatty acids, indicating active, but inefficient import of host fatty acids. Our experiments highlight a gap between the fatty acid needs of the parasite and availability of specific fatty acids in the host cell that the parasite has to close using a dedicated synthesis and modification pathway. PMID:25825226

  14. Genes Involved in Long-Chain Alkene Biosynthesis in Micrococcus luteus▿

    PubMed Central

    Beller, Harry R.; Goh, Ee-Been; Keasling, Jay D.

    2010-01-01

    Aliphatic hydrocarbons are highly appealing targets for advanced cellulosic biofuels, as they are already predominant components of petroleum-based gasoline and diesel fuels. We have studied alkene biosynthesis in Micrococcus luteus ATCC 4698, a close relative of Sarcina lutea (now Kocuria rhizophila), which 4 decades ago was reported to biosynthesize iso- and anteiso-branched, long-chain alkenes. The underlying biochemistry and genetics of alkene biosynthesis were not elucidated in those studies. We show here that heterologous expression of a three-gene cluster from M. luteus (Mlut_13230-13250) in a fatty acid-overproducing Escherichia coli strain resulted in production of long-chain alkenes, predominantly 27:3 and 29:3 (no. carbon atoms: no. C 000000000000 000000000000 000000000000 111111111111 000000000000 111111111111 000000000000 000000000000 000000000000 C bonds). Heterologous expression of Mlut_13230 (oleA) alone produced no long-chain alkenes but unsaturated aliphatic monoketones, predominantly 27:2, and in vitro studies with the purified Mlut_13230 protein and tetradecanoyl-coenzyme A (CoA) produced the same C27 monoketone. Gas chromatography-time of flight mass spectrometry confirmed the elemental composition of all detected long-chain alkenes and monoketones (putative intermediates of alkene biosynthesis). Negative controls demonstrated that the M. luteus genes were responsible for production of these metabolites. Studies with wild-type M. luteus showed that the transcript copy number of Mlut_13230-13250 and the concentrations of 29:1 alkene isomers (the dominant alkenes produced by this strain) generally corresponded with bacterial population over time. We propose a metabolic pathway for alkene biosynthesis starting with acyl-CoA (or-ACP [acyl carrier protein]) thioesters and involving decarboxylative Claisen condensation as a key step, which we believe is catalyzed by OleA. Such activity is consistent with our data and with the homology (including the

  15. Peanut consumption increases levels of plasma very long chain fatty acids in humans.

    PubMed

    Lam, Christina; Wong, Derek; Cederbaum, Stephen; Lim, Bennie; Qu, Yong

    2012-11-01

    Peanut consumption has been suspected of raising plasma very long chain fatty acid (VLCFA) levels in humans. The effect of peanut consumption on VLCFAs was studied in six human subjects. After 3 to 4h of peanut butter ingestion, plasma C26:0 and C26:0/C22:0 were found to be significantly elevated to levels seen in patients with peroxisomal disorders. These levels returned to normal within 12h. Peanut consumption needs to be accounted for when interpreting VLCFAs. PMID:22864056

  16. A Novel Protocol to Analyze Short- and Long-Chain Fatty Acids Using Nonaqueous Microchip Capillary Electrophoresis

    NASA Technical Reports Server (NTRS)

    Cable, M. L.; Stockton, A. M.; Mora, Maria F; Willis, P. A.

    2013-01-01

    We propose a new protocol to identify and quantify both short- and long-chain saturated fatty acids in samples of astrobiological interest using non-aqueous microchip capillary electrophoresis (micronNACE) with laser induced fluorescence (LIF).

  17. An Open-label Phase 2 Study of UX007 (Triheptanoin) in Subjects With Long-Chain Fatty Acid Oxidation Disorders (LC-FAOD)

    ClinicalTrials.gov

    2015-12-15

    Long-chain Fatty Acid Oxidation Disorders (LC-FAOD); Carnitine Palmitoyltransferase (CPT II) Deficiency; Very Long Chain Acyl-CoA Dehydrogenase (VLCAD) Deficiency; Longchain 3-hydroxy-acyl-CoA Dehydrogenase (LCHAD) Deficiency; Trifunctional Protein (TFP) Deficiency

  18. The association of serum long-chain n-3 PUFA and hair mercury with exercise cardiac power in men.

    PubMed

    Tajik, Behnam; Kurl, Sudhir; Tuomainen, Tomi-Pekka; Virtanen, Jyrki K

    2016-08-01

    Long-chain n-3 PUFA from fish and exercise capacity are associated with CVD risk. Fish, especially large and old predatory fish, may contain Hg, which may attenuate the inverse association of long-chain n-3 PUFA with CVD. However, the associations of long-chain n-3 PUFA or Hg exposure with exercise capacity are not well known. We aimed to evaluate the associations of serum long-chain n-3 PUFA EPA, docosapentaenoic acid (DPA) and DHA and hair Hg with exercise cardiac power (ECP, a ratio of VO2max:maximal systolic blood pressure (SBP) during an exercise test), a measure for exercise capacity. For this, data from the population-based Kuopio Ischaemic Heart Disease Risk Factor Study were analysed cross-sectionally in order to determine the associations between serum long-chain n-3 PUFA, hair Hg and ECP in 1672 men without CVD, aged 42-60 years. After multivariate adjustments, serum total long-chain n-3 PUFA concentration was associated with higher ECP and VO2max (P trend across quartiles=0·04 and P trend=0·02, respectively), but not with maximal SBP (P trend=0·69). Associations were generally similar when EPA, DPA and DHA were evaluated individually. Hair Hg was not associated with ECP, VO2max or maximal SBP. However, the associations of total long-chain n-3 PUFA (P interaction=0·03) and EPA (P interaction=0·02) with higher VO2max were stronger among men with lower hair Hg. Higher serum long-chain n-3 PUFA concentration, mainly a marker for fish consumption in this study population, was associated with higher ECP and VO2max in middle-aged men from eastern Finland. PMID:27255152

  19. Identification of long chain specific aldehyde reductase and its use in enhanced fatty alcohol production in E. coli.

    PubMed

    Fatma, Zia; Jawed, Kamran; Mattam, Anu Jose; Yazdani, Syed Shams

    2016-09-01

    Long chain fatty alcohols have wide application in chemical industries and transportation sector. There is no direct natural reservoir for long chain fatty alcohol production, thus many groups explored metabolic engineering approaches for its microbial production. Escherichia coli has been the major microbial platform for this effort, however, terminal endogenous enzyme responsible for converting fatty aldehydes of chain length C14-C18 to corresponding fatty alcohols is still been elusive. Through our in silico analysis we selected 35 endogenous enzymes of E. coli having potential of converting long chain fatty aldehydes to fatty alcohols and studied their role under in vivo condition. We found that deletion of ybbO gene, which encodes NADP(+) dependent aldehyde reductase, led to >90% reduction in long chain fatty alcohol production. This feature was found to be strain transcending and reinstalling ybbO gene via plasmid retained the ability of mutant to produce long chain fatty alcohols. Enzyme kinetic study revealed that YbbO has wide substrate specificity ranging from C6 to C18 aldehyde, with maximum affinity and efficiency for C18 and C16 chain length aldehyde, respectively. Along with endogenous production of fatty aldehyde via optimized heterologous expression of cyanobaterial acyl-ACP reductase (AAR), YbbO overexpression resulted in 169mg/L of long chain fatty alcohols. Further engineering involving modulation of fatty acid as well as of phospholipid biosynthesis pathway improved fatty alcohol production by 60%. Finally, the engineered strain produced 1989mg/L of long chain fatty alcohol in bioreactor under fed-batch cultivation condition. Our study shows for the first time a predominant role of a single enzyme in production of long chain fatty alcohols from fatty aldehydes as well as of modulation of phospholipid pathway in increasing the fatty alcohol production. PMID:27134112

  20. Plasmodium falciparum Sir2A preferentially hydrolyzes medium and long chain fatty acyl lysine

    PubMed Central

    Zhu, Anita Y.; Zhou, Yeyun; Khan, Saba; Deitsch, Kirk W.; Hao, Quan; Lin, Hening

    2011-01-01

    Plasmodium falciparum Sir2A (PfSir2A), a member of the sirtuin family of nicotinamide adenine dinucleotide-dependent deacetylases, has been shown to regulate the expression of surface antigens to evade the detection by host immune surveillance. It is thought that PfSir2A achieves this by deacetylating histones. However, the deacetylase activity of PfSir2A is weak. Here we present enzymology and structural evidences supporting that PfSir2A catalyzes the hydrolysis of medium and long chain fatty acyl groups from lysine residues more efficiently. Furthermore, P. falciparum proteins are found to contain such fatty acyl lysine modifications that can be removed by purified PfSir2A in vitro. Together, the data suggest that the physiological function of PfSir2A in antigen variation may be achieved by removing medium and long chain fatty acyl groups from protein lysine residues. The robust activity of PfSir2A would also facilitate the development of PfSir2A inhibitors, which may have therapeutic value in malaria treatment. PMID:21992006

  1. Long-chain amine-templated synthesis of gallium sulfide and gallium selenide nanotubes

    NASA Astrophysics Data System (ADS)

    Seral-Ascaso, A.; Metel, S.; Pokle, A.; Backes, C.; Zhang, C. J.; Nerl, H. C.; Rode, K.; Berner, N. C.; Downing, C.; McEvoy, N.; Muñoz, E.; Harvey, A.; Gholamvand, Z.; Duesberg, G. S.; Coleman, J. N.; Nicolosi, V.

    2016-06-01

    We describe the soft chemistry synthesis of amine-templated gallium chalcogenide nanotubes through the reaction of gallium(iii) acetylacetonate and the chalcogen (sulfur, selenium) using a mixture of long-chain amines (hexadecylamine and dodecylamine) as a solvent. Beyond their role as solvent, the amines also act as a template, directing the growth of discrete units with a one-dimensional multilayer tubular nanostructure. These new materials, which broaden the family of amine-stabilized gallium chalcogenides, can be tentatively classified as direct large band gap semiconductors. Their preliminary performance as active material for electrodes in lithium ion batteries has also been tested, demonstrating great potential in energy storage field even without optimization.We describe the soft chemistry synthesis of amine-templated gallium chalcogenide nanotubes through the reaction of gallium(iii) acetylacetonate and the chalcogen (sulfur, selenium) using a mixture of long-chain amines (hexadecylamine and dodecylamine) as a solvent. Beyond their role as solvent, the amines also act as a template, directing the growth of discrete units with a one-dimensional multilayer tubular nanostructure. These new materials, which broaden the family of amine-stabilized gallium chalcogenides, can be tentatively classified as direct large band gap semiconductors. Their preliminary performance as active material for electrodes in lithium ion batteries has also been tested, demonstrating great potential in energy storage field even without optimization. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr01663d

  2. Retinal very long-chain PUFAs: new insights from studies on ELOVL4 protein

    PubMed Central

    Agbaga, Martin-Paul; Mandal, Md Nawajes A.; Anderson, Robert E.

    2010-01-01

    Compared with other mammalian tissues, retina is highly enriched in PUFA. Long-chain PUFA (LC-PUFA; C18-C24) are essential FAs that are enriched in the retina and are necessary for maintenance of normal retinal development and function. The retina, brain, and sperm also contain very LC-PUFA (VLC-PUFA; >C24). Although VLC-PUFA were discovered more than two decades ago, very little is known about their biosynthesis and functional roles in the retina. This is due mainly to intrinsic difficulties associated with working on these unusually long polyunsaturated hydrocarbon chains and their existence in small amounts. Recent studies on the FA elongase elongation of very long chain fatty acids-4 (ELOVL4) protein, however, suggest that VLC-PUFA probably play some uniquely important roles in the retina as well as the other tissues. Mutations in the ELOVL4 gene are found in patients with autosomal dominant Stargardt disease. Here, we review the recent literature on VLC-PUFA with special emphasis on the elongases responsible for their synthesis. We focus on a novel elongase, ELOVL4, involved in the synthesis of VLC-PUFA, and the importance of these FAs in maintaining the structural and functional integrity of retinal photoreceptors. PMID:20299492

  3. Measurement of Long-Chain Fatty Acyl-CoA Synthetase Activity.

    PubMed

    Füllekrug, Joachim; Poppelreuther, Margarete

    2016-01-01

    Long-chain fatty acyl-CoA synthetases (ACS) are a family of essential enzymes of lipid metabolism, activating fatty acids by thioesterification with coenzyme A. Fatty acyl-CoA molecules are then readily utilized for the biosynthesis of storage and membrane lipids, or for the generation of energy by ß-oxidation. Acyl-CoAs also function as transcriptional activators, allosteric inhibitors, or precursors for inflammatory mediators. Recent work suggests that ACS enzymes may drive cellular fatty acid uptake by metabolic trapping, and may also regulate the channeling of fatty acids towards specific metabolic pathways. The implication of ACS enzymes in widespread lipid associated diseases like type 2 diabetes has rekindled interest in this protein family. Here, we describe in detail how to measure long-chain fatty acyl-CoA synthetase activity by a straightforward radiometric assay. Cell lysates are incubated with ATP, coenzyme A, Mg(2+), and radiolabeled fatty acid bound to BSA. Differential phase partitioning of fatty acids and acyl-CoAs is exploited to quantify the amount of generated acyl-CoA by scintillation counting. The high sensitivity of this assay also allows the analysis of small samples like patient biopsies. PMID:26552674

  4. Conversion of raw lignocellulosic biomass into branched long-chain alkanes through three tandem steps.

    PubMed

    Li, Chunrui; Ding, Daqian; Xia, Qineng; Liu, Xiaohui; Wang, Yanqin

    2016-07-01

    Synthesis of branched long-chain alkanes from renewable biomass has attracted intensive interest in recent years, but the feedstock for this synthesis is restricted to platform chemicals. Here, we develop an effective and energy-efficient process to convert raw lignocellulosic biomass (e.g., corncob) into branched diesel-range alkanes through three tandem steps for the first time. Furfural and isopropyl levulinate (LA ester) were prepared from hemicellulose and cellulose fractions of corncob in toluene/water biphasic system with added isopropanol, which was followed by double aldol condensation of furfural with LA ester into C15 oxygenates and the final hydrodeoxygenation of C15 oxygenates into branched long-chain alkanes. The core point of this tandem process is the addition of isopropanol in the first step, which enables the spontaneous transfer of levulinic acid (LA) into the toluene phase in the form of LA ester through esterification, resulting in LA ester co-existing with furfural in the same phase, which is the basis for double aldol condensation in the toluene phase. Moreover, the acidic aqueous phase and toluene can be reused and the residues, including lignin and humins in aqueous phase, can be separated and carbonized to porous carbon materials. PMID:27241180

  5. Phs1 and the Synthesis of Very Long Chain Fatty Acids Are Required for Ballistospore Formation

    PubMed Central

    Ianiri, Giuseppe; Abhyankar, Ritika; Kihara, Akio; Idnurm, Alexander

    2014-01-01

    The production and dissemination of spores by members of the fungal kingdom is a major reason for the success of this eukaryotic lineage in colonizing most terrestrial ecosystems. Ballistospores are a type of spore produced by basidiomycete fungi, such as the mushrooms and plant pathogenic rusts. These spores are forcefully discharged through a unique liquid-drop fusion mechanism, enabling the aerosolization of these particles that can contribute to plant disease and human allergies. The genes responsible for this process are unknown due to technical challenges in studying many of the fungi that produce ballistospores. Here, we applied newly-developed techniques in a forward genetic screen to identify genes required for ballistospore formation or function in a tractable red yeast, a species of Sporobolomyces. One strain bearing a mutation in the PHS1 gene was identified as a mirror mutant. PHS1 encodes 3-hydroxyacyl-CoA dehydratase required for the third step in very long chain fatty acid biosynthesis. The Sporobolomyces PHS1 gene complements the essential functions of a S. cerevisiae phs1 mutant. The Sporobolomyces phs1 mutant strain has less dehydratase activity and a reduction in very long chain fatty acids compared to wild type. The mutant strain also exhibits sensitivity to cell wall stress agents and loss of shooting due to a delay in ballistospore formation, indicating that the role of Phs1 in spore dissemination may be primarily in cellular integrity. PMID:25148260

  6. Long-chain polyunsaturated fatty acids and the pathophysiology of myalgic encephalomyelitis (chronic fatigue syndrome).

    PubMed

    Puri, B K

    2007-02-01

    Evidence is put forward to suggest that myalgic encephalomyelitis, also known as chronic fatigue syndrome, may be associated with persistent viral infection. In turn, such infections are likely to impair the ability of the body to biosynthesise n-3 and n-6 long-chain polyunsaturated fatty acids by inhibiting the delta-6 desaturation of the precursor essential fatty acids--namely, alpha-linolenic acid and linoleic acid. This would, in turn, impair the proper functioning of cell membranes, including cell signalling, and have an adverse effect on the biosynthesis of eicosanoids from the long-chain polyunsaturated fatty acids dihomo-gamma-linolenic acid, arachidonic acid and eicosapentaenoic acid. These actions might offer an explanation for some of the symptoms and signs of myalgic encephalomyelitis. A potential therapeutic avenue could be offered by bypassing the inhibition of the enzyme delta-6-desaturase by treatment with virgin cold-pressed non-raffinated evening primrose oil, which would supply gamma-linolenic acid and lipophilic pentacyclic triterpenes, and with eicosapentaenoic acid. The gamma-linolenic acid can readily be converted into dihomo-gamma-linolenic acid and thence arachidonic acid, while triterpenes have important free radical scavenging, cyclo-oxygenase and neutrophil elastase inhibitory activities. Furthermore, both arachidonic acid and eicosapentaenoic acid are, at relatively low concentrations, directly virucidal. PMID:16935966

  7. Interfacial properties of mixed films of long-chain organics at the air-water interface

    NASA Astrophysics Data System (ADS)

    Gilman, Jessica B.; Tervahattu, Heikki; Vaida, Veronica

    Organic molecules residing at the air-water interface of atmospheric aerosols will have a critical and direct effect on the aerosols' chemical, physical, and optical properties. It is important to study the interfacial properties of such compounds in order to accurately assess these effects. In this study, the compositions of two organic binary films at the air-water interface were monitored as a function of exposure time to the ambient atmosphere. One film was composed of tetracosanoic acid (lignoceric acid, CH 3(CH 2) 22COOH) and nonacosane (C 29H 60), and the second film was composed of octadecanoic acid (stearic acid, CH 3(CH 2) 16COOH) and octadecane (C 18H 38). These films were used as simplified proxies for the organic coating on atmospheric aerosols. The effect of lengthening the hydrocarbon chain on the interfacial longevity of the compounds in the mixed organic film at the air-aqueous interface was determined. The results show that octadecane in a mixed film desorbs from the interface after 72 h while octadecanoic acid remains. For nonacosane, further lengthening of the carbon chain greatly increased its interfacial longevity so that it was comparable with the fatty acids, which remained stable at the interface for at least 144 h. These results are used to explain the preponderance of long-chain fatty acids on the surfaces of collected aerosols and give insight into the degree to which the presence of other long-chain organics may affect the aerosol's chemical and physical properties.

  8. Mouse very long-chain acyl-CoA synthetase in X-linked adrenoleukodystrophy.

    PubMed

    Heinzer, Ann K; Kemp, Stephan; Lu, Jyh-Feng; Watkins, Paul A; Smith, Kirby D

    2002-08-01

    X-linked adrenoleukodystrophy (X-ALD) is a neurodegenerative disorder characterized by accumulation of very long-chain fatty acids (VLCFA). This accumulation has been attributed to decreased VLCFA beta-oxidation and peroxisomal very long-chain acyl-CoA synthetase (VLCS) activity. The X-ALD gene, ABCD1, encodes a peroxisomal membrane ATP binding cassette transporter, ALDP, that is hypothesized to affect VLCS activity in peroxisomes by direct interaction with the VLCS enzyme. Recently, a VLCS gene that encodes a protein with significant sequence identity to known rat and human peroxisomal VLCS protein has been identified in mice. We find that the mouse VLCS gene (Vlcs) encodes an enzyme (Vlcs) with VLCS activity that localizes to peroxisomes and is expressed in X-ALD target tissues. We show that the expression of Vlcs in the peroxisomes of X-ALD mouse fibroblasts improves VLCFA beta-oxidation in these cells, implying a role for this enzyme in the biochemical abnormality of X-ALD. X-ALD mice, which accumulate VLCFA in tissues, show no change in the expression of Vlcs, the subcellular localization of Vlcs, or general peroxisomal VLCS activity. These observations imply that ALDP is not necessary for the proper expression or localization of Vlcs protein, and the control of VLCFA levels does not depend on the direct interaction of Vlcs and ALDP. PMID:12048192

  9. High orientation of long chain branched poly (lactic acid) with enhanced blood compatibility and bionic structure.

    PubMed

    Li, Zhengqiu; Ye, Lin; Zhao, Xiaowen; Coates, Phil; Caton-Rose, Fin; Martyn, Michasel

    2016-05-01

    Highly oriented poly (lactic acid) (PLA) with bionic microgrooves was fabricated through solid hot drawing technology for further improving the mechanical properties and blood biocompatibility of PLA. In order to enhance the melt strength and thus obtain high orientation degree, long chain branched PLA was prepared at first through a two-step ring-opening reaction during processing. Linear viscoelasticity combined with branch-on-branch model was used to predict probable compositions and chain topologies of the products, and it was found that the molecular weight of PLA increased and topological structures with star like chain with three arms and tree-like chain with two generations formed during reactive processing, and consequently draw ratio as high as1200% can be achieved during the subsequent hot stretching. With the increase of draw ratio, the tensile strength and orientation degree of PLA increased dramatically. Long chain branching and orientation could significantly enhance the blood compatibility of PLA by prolonging clotting time and decreasing platelet activation. Microgrooves can be observed on the surface of the oriented PLA which were similar to the intimal layer of blood vessel, and such bionic structure resulted from the formation of the oriented shish kebab-like crystals along the draw direction. PMID:26743130

  10. First Genome Sequence of a Syntrophic Acetate-Oxidizing Bacterium, Tepidanaerobacter acetatoxydans Strain Re1.

    PubMed

    Manzoor, Shahid; Bongcam-Rudloff, Erik; Schnürer, Anna; Müller, Bettina

    2013-01-01

    Syntrophic acetate-oxidizing bacteria (SAOB) have been identified as key organisms for efficient biogas production from protein-rich materials. Tepidanaerobacter acetatoxydans is the first reported SAOB for which the genome has been sequenced. Genome analysis will aid us in understanding the mechanisms regulating syntrophy, particularly energy-conserving and electron transfer mechanisms. PMID:23469343

  11. First Genome Sequence of a Syntrophic Acetate-Oxidizing Bacterium, Tepidanaerobacter acetatoxydans Strain Re1

    PubMed Central

    Manzoor, Shahid; Bongcam-Rudloff, Erik; Schnürer, Anna

    2013-01-01

    Syntrophic acetate-oxidizing bacteria (SAOB) have been identified as key organisms for efficient biogas production from protein-rich materials. Tepidanaerobacter acetatoxydans is the first reported SAOB for which the genome has been sequenced. Genome analysis will aid us in understanding the mechanisms regulating syntrophy, particularly energy-conserving and electron transfer mechanisms. PMID:23469343

  12. DISTINCT TRANSCRIPTIONAL REGULATION OF LONG-CHAIN ACYL-COA SYNTHETASE ISOFORMS AND CYTOSOLIC THIOESTERASE 1 IN THE RODENT HEART BY FATTY ACIDS AND INSULIN

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The molecular mechanism(s) responsible for channeling long-chain fatty acids (LCFAs) into oxidative versus nonoxidative pathways is (are) poorly understood in the heart. Intracellular LCFAs are converted to long-chain fatty acyl-CoAs (LCFA-CoAs) by a family of long-chain acyl-CoA synthetases (ACSLs)...

  13. Archaeal and anaerobic methane oxidizer communities in the Sonora Margin cold seeps, Guaymas Basin (Gulf of California)

    PubMed Central

    Vigneron, Adrien; Cruaud, Perrine; Pignet, Patricia; Caprais, Jean-Claude; Cambon-Bonavita, Marie-Anne; Godfroy, Anne; Toffin, Laurent

    2013-01-01

    Cold seeps, located along the Sonora Margin transform fault in the Guaymas Basin, were extensively explored during the ‘BIG' cruise in June 2010. They present a seafloor mosaic pattern consisting of different faunal assemblages and microbial mats. To investigate this mostly unknown cold and hydrocarbon-rich environment, geochemical and microbiological surveys of the sediments underlying two microbial mats and a surrounding macrofaunal habitat were analyzed in detail. The geochemical measurements suggest biogenic methane production and local advective sulfate-rich fluxes in the sediments. The distributions of archaeal communities, particularly those involved in the methane cycle, were investigated at different depths (surface to 18 cm below the sea floor (cmbsf)) using complementary molecular approaches, such as Automated method of Ribosomal Intergenic Spacer Analysis (ARISA), 16S rRNA libraries, fluorescence in situ hybridization and quantitative polymerase chain reaction with new specific primer sets targeting methanogenic and anaerobic methanotrophic lineages. Molecular results indicate that metabolically active archaeal communities were dominated by known clades of anaerobic methane oxidizers (archaeal anaerobic methanotroph (ANME)-1, -2 and -3), including a novel ‘ANME-2c Sonora' lineage. ANME-2c were found to be dominant, metabolically active and physically associated with syntrophic Bacteria in sulfate-rich shallow sediment layers. In contrast, ANME-1 were more prevalent in the deepest sediment samples and presented a versatile behavior in terms of syntrophic association, depending on the sulfate concentration. ANME-3 were concentrated in small aggregates without bacterial partners in a restricted sediment horizon below the first centimetres. These niche specificities and syntrophic behaviors, depending on biological surface assemblages and environmental availability of electron donors, acceptors and carbon substrates, suggest that ANME could support

  14. Synergistic effects of the chitosan addition and polysaccharides-EPS on the formation of anaerobic granules.

    PubMed

    Hudayah, N; Suraraksa, B; Chaiprasert, P

    2016-11-01

    Concomitant early granulation with chitosan addition under a syntroph-specific substrate and enhancement of extracellular polymeric substances (EPS) production were aimed at to build anaerobic granules with high syntrophic activities in a short period. Two laboratory-scale upflow anaerobic sludge blanket reactors were operated as control (R1) and chitosan addition (R2) reactors during early granulation (phase 1). Chitosan decreased the negativity of microbial surface charges (zeta potential) to -10.5 mV on day 58 which led to increases in average diameter sizes, nuclei and granule ratio of approximately 115 µm, 55.1% and 8.2%, respectively. While zeta potential in R1 slightly changed, this resulted in less microbial aggregation. Although microbial aggregation in R2 was rapidly triggered by chitosan addition during phase 1, its structure was clumpy with rough surface due to lack of EPS. Substrate switching to glucose increased polysaccharides-EPS during phase 2 which was synergistically improved on the structural characteristics of microbial aggregate in R2, that is, more spherical and compact, with a smoother surface. Rapid-growth microorganism was also boosted, which then dominated the outer layer of the aggregate. The Archaea clumps were observed at a deeper layer and were surrounded by Eubacteria, presumably acetogens, indicating a syntrophic relationship due to substrate association between these microbial groups. PMID:27553457

  15. Sources and proxy potential of long chain alkyl diols in lacustrine environments

    NASA Astrophysics Data System (ADS)

    Rampen, Sebastiaan W.; Datema, Mariska; Rodrigo-Gámiz, Marta; Schouten, Stefan; Reichart, Gert-Jan; Sinninghe Damsté, Jaap S.

    2014-11-01

    Long chain 1,13- and 1,15-alkyl diols form the base of a number of recently proposed proxies used for climate reconstruction. However, the sources of these lipids and environmental controls on their distribution are still poorly constrained. We have analyzed the long chain alkyl diol (LCD) composition of cultures of ten eustigmatophyte species, with three species from different families grown at various temperatures, to identify the effect of species composition and growth temperature on the LCD distribution. The results were compared with the LCD distribution of sixty-two lake surface sediments, and with previously reported LCD distributions from marine environments. The different families within the Eustigmatophyceae show distinct LCD patterns, with the freshwater family Eustigmataceae most closely resembling LCD distributions in both marine and lake environments. Unlike the other two eustigmatophyte families analyzed (Monodopsidaceae and Goniochloridaceae), C28 and C30 1,13-alkyl diols and C30 and C32 1,15-alkyl diols are all relatively abundant in the family Eustigmataceae, while the mono-unsaturated C32 1,15-alkyl diol was below detection limit. In contrast to the marine environment, LCD distributions in lakes did not show a clear relationship with temperature. The Long chain Diol Index (LDI), a proxy previously proposed for sea surface temperature reconstruction, showed a relatively weak correlation (R2 = 0.33) with mean annual air temperature used as an approximation for annual mean surface temperature of the lakes. A much-improved correlation (R2 = 0.74, p-value <0.001) was observed applying a multiple linear regression analysis between LCD distributions and lake temperatures reconstructed using branched tetraether lipid distributions. The obtained regression model provides good estimates of temperatures for cultures of the family Eustigmataceae, suggesting that algae belonging to this family have an important role as a source for LCDs in lacustrine

  16. Determination of the fractions of syntrophically oxidized acetate in a mesophilic methanogenic reactor through an (12)C and (13)C isotope-based kinetic model.

    PubMed

    Gehring, Tito; Niedermayr, Andrea; Berzio, Stephan; Immenhauser, Adrian; Wichern, Marc; Lübken, Manfred

    2016-10-01

    In order to accurately describe the carbon flow in anaerobic digestion processes, this work investigates the acetate degradation pathways through the use of stable carbon isotope analysis and a mathematical model. Batch assays using labeled (13)C acetate were employed to distinguish the acetate consumption through methanogenic Archaea and acetate-oxidizing Bacteria. Suspended and sessile biomass, with over 400 days of retention time, from a mesophilic (36.5 °C) upflow anaerobic filter was used as inocula in these assays. A three-process model for acetoclastic methanogenesis and syntrophic acetate oxidation (SAO) was developed to allow for a precise quantification of the SAO contribution. The model distinguishes carbon atoms in light and heavy isotopes, (12)C and (13)C, respectively, which permitted the simulation of the isotope ratios variation in addition to gas production, gas composition and acetate concentrations. The model indicated oxidized fractions of acetate between 7 and 18%. Due to the low free ammonia inhibition potential for the acetoclastic methanogens in these assays these findings point to the biomass retention times as a driven factor for the SAO pathway. The isotope-based kinetic model developed here also describes the δ(13)C variations in unlabeled assays accurately and has the potential to determine biological (13)C fractionation factors. PMID:27390036

  17. Thermophilic anaerobic digestion of thermal pretreated sludge: role of microbial community structure and correlation with process performances.

    PubMed

    Gagliano, M C; Braguglia, C M; Gianico, A; Mininni, G; Nakamura, K; Rossetti, S

    2015-01-01

    Thermal hydrolysis pretreatment coupled with Thermophilic Anaerobic Digestion (TAD) for Waste Activated Sludge (WAS) treatment is a promising combination to improve biodegradation kinetics during stabilization. However, to date there is a limited knowledge of the anaerobic biomass composition and its impact on TAD process performances. In this study, the structure and dynamics of the microbial communities selected in two semi-continuous anaerobic digesters, fed with untreated and thermal pretreated sludge, were investigated. The systems were operated for 250 days at different organic loading rate. 16S rRNA gene clonal analysis and Fluorescence In Situ Hybridization (FISH) analyses allowed us to identify the majority of bacterial and archaeal populations. Proteolytic Coprothermobacter spp. and hydrogenotrophic Methanothermobacter spp. living in strict syntrophic association were found to dominate in TAD process. The establishment of a syntrophic proteolytic pathway was favoured by the high temperature of the process and enhanced by the thermal pretreatment of the feeding sludge. Proteolytic activity, alone or with thermal pretreatment, occurred during TAD as proven by increasing concentration of soluble ammonia and soluble COD (sCOD) during the process. However, the availability of a readily biodegradable substrate due to pretreatment allowed to significant sCOD removals (more than 55%) corresponding to higher biogas production in the reactor fed with thermal pretreated sludge. Microbial population dynamics analysed by FISH showed that Coprothermobacter and Methanothermobacter immediately established a stable syntrophic association in the reactor fed with pretreated sludge in line with the overall improved TAD performances observed under these conditions. PMID:25462756

  18. Long-Chain Omega-3 Oils–An Update on Sustainable Sources

    PubMed Central

    Nichols, Peter D.; Petrie, James; Singh, Surinder

    2010-01-01

    Seafood is currently the best and generally a safe source of long-chain (LC, (≥C20) omega-3 oils amongst the common food groups. LC omega-3 oils are also obtained in lower amounts per serve from red meat, egg and selected other foods. As global population increases the opportunities to increase seafood harvest are limited, therefore new alternate sources are required. Emerging sources include microalgae and under-utilized resources such as Southern Ocean krill. Prospects for new land plant sources of these unique and health-benefiting oils are also particularly promising, offering hope for alternate and sustainable supplies of these key oils, with resulting health, social, economic and environmental benefits. PMID:22254042

  19. Long-chain amine-templated synthesis of gallium sulfide and gallium selenide nanotubes.

    PubMed

    Seral-Ascaso, A; Metel, S; Pokle, A; Backes, C; Zhang, C J; Nerl, H C; Rode, K; Berner, N C; Downing, C; McEvoy, N; Muñoz, E; Harvey, A; Gholamvand, Z; Duesberg, G S; Coleman, J N; Nicolosi, V

    2016-06-01

    We describe the soft chemistry synthesis of amine-templated gallium chalcogenide nanotubes through the reaction of gallium(iii) acetylacetonate and the chalcogen (sulfur, selenium) using a mixture of long-chain amines (hexadecylamine and dodecylamine) as a solvent. Beyond their role as solvent, the amines also act as a template, directing the growth of discrete units with a one-dimensional multilayer tubular nanostructure. These new materials, which broaden the family of amine-stabilized gallium chalcogenides, can be tentatively classified as direct large band gap semiconductors. Their preliminary performance as active material for electrodes in lithium ion batteries has also been tested, demonstrating great potential in energy storage field even without optimization. PMID:27221399

  20. Short-term phenotypic plasticity in long-chain cuticular hydrocarbons.

    PubMed

    Thomas, Melissa L; Simmons, Leigh W

    2011-10-22

    Cuticular hydrocarbons provide arthropods with the chemical equivalent of the visually extravagant plumage of birds. Their long chain length, together with the number and variety of positions in which methyl branches and double bonds occur, provide cuticular hydrocarbons with an extraordinary level of information content. Here, we demonstrate phenotypic plasticity in an individual's cuticular hydrocarbon profile. Using solid-phase microextraction, a chemical technique that enables multiple sampling of the same individual, we monitor short-term changes in cuticular hydrocarbon profiles of individual crickets, Teleogryllus oceanicus, in response to a social challenge. We experimentally manipulate the dominance status of males and find that dominant males, on losing fights with other dominant males, change their hydrocarbon profile to more closely resemble that of a subordinate. This result demonstrates that cuticular hydrocarbons can be far more responsive to changes in social dominance than previously realized. PMID:21367785

  1. Long-chain polyunsaturated fatty acid sources and evaluation of their nutritional and functional properties

    PubMed Central

    Abedi, Elahe; Sahari, Mohammad Ali

    2014-01-01

    Recent studies have clearly shown the importance of polyunsaturated fatty acids (as essential fatty acids) and their nutritional value for human health. In this review, various sources, nutritional properties, and metabolism routes of long-chain polyunsaturated fatty acids (LC-PUFA) are introduced. Since the conversion efficiency of linoleic acid (LA) to arachidonic acid (AA) and also α-linolenic acid (ALA) to docosahexaenoic acid (DHA) and eicosatetraenoic acid (EPA) is low in humans, looking for the numerous sources of AA, EPA and EPA fatty acids. The sources include aquatic (fish, crustaceans, and mollusks), animal sources (meat, egg, and milk), plant sources including 20 plants, most of which were weeds having a good amount of LC-PUFA, fruits, herbs, and seeds; cyanobacteria; and microorganisms (bacteria, fungi, microalgae, and diatoms). PMID:25473503

  2. Isolation and characterization of a novel thermophilic Bacillus strain degrading long-chain n-alkanes.

    PubMed

    Wang, Lei; Tang, Yun; Wang, Shuo; Liu, Ru-Lin; Liu, Mu-Zhi; Zhang, Yan; Liang, Feng-Lai; Feng, Lu

    2006-08-01

    A thermophilic Bacillus strain NG80-2 growing within the temperature range of 45-73 degrees C (optimum at 65 degrees C) was isolated from a deep subterranean oil-reservoir in northern China. The strain was able to utilize crude oil and liquid paraffin as the sole carbon sources for growth, and the growth with crude oil was accompanied by the production of an unknown emulsifying agent. Further examination showed that NG80-2 degraded and utilized only long-chain (C15-C36) n-alkanes, but not short-chain (C8-C14) n-alkanes and those longer than C40. Based on phenotypic and phylogenic analyses, NG80-2 was identified as Geobacillus thermodenitrificans. The strain NG80-2 may be potentially used for oily-waste treatment at elevated temperature, a condition which greatly accelerates the biodegradation rate, and for microbial enhancing oil recovery process. PMID:16604274

  3. Inhibition of Long Chain Fatty Acyl-CoA Synthetase (ACSL) and Ischemia Reperfusion Injury

    PubMed Central

    Prior, Allan M.; Zhang, Man; Blakeman, Nina; Datta, Palika; Pham, Hung; Young, Lindon H.; Weis, Margaret T.; Hua, Duy H.

    2014-01-01

    Various triacsin C analogs, containing different alkenyl chains and carboxylic acid bioisoteres including 4-aminobenzoic acid, isothiazolidine dioxide, hydroxylamine, hydroxytriazene, and oxadiazolidine dione, were synthesized and their inhibitions of long chain fatty acyl-CoA synthetase (ACSL) were examined. Two methods, a cell-based assay of ACSL activity and an in situ [14C]-palmitate incorporation into extractable lipids were used to study the inhibition. Using an in vivo leukocyte recruitment inhibition protocol, the translocation of one or more cell adhesion molecules from the cytoplasm to the plasma membrane on either the endothelium or leukocyte or both was inhibited by inhibitors 1, 9, and triacsin C. The results suggest that inhibition of ACSL may attenuate the vascular inflammatory component associated with ischemia reperfusion injury and lead to a decrease of infarct expansion. PMID:24480468

  4. Protein kinase C inhibition by sphingoid long-chain bases: effects on secretion in human neutrophils

    SciTech Connect

    Wilson, E.; Arnold, R.R.; Merrill, A.H.; Lambeth, J.D.

    1987-05-01

    Sphingoid long-chain bases (sphinganine and sphingosine(So)) have recently been shown to inhibit protein kinase C (PK-C) in vitro and to block activation of the oxidative burst in intact neutrophils (PMN) by inhibiting this enzyme. In the present study, the authors have used So to investigate the role of protein kinase C in stimulus-induced secretion of PMN granule contents. Secretion of the specific granule component lactoferrin (Lf) is completely inhibited by pretreatment with So when either PMA or fLMP is used as the secretogogue. Secretion of lysozyme, a component of both the azurophilic and specific granules, is completely inhibited by So when PMA is used, but only 40% inhibited with fMLP. The secretion of the azurophilic granule markers US -glucuronidase and myeloperoxidase was not affected by So regardless of the agonist used. Data indicate that both PK-C-dependent and -independent pathways participate in the neutrophil secretory response.

  5. Very long chain fatty acid and lipid signaling in the response of plants to pathogens

    PubMed Central

    Raffaele, Sylvain; Leger, Amandine

    2009-01-01

    Recent findings indicate that lipid signaling is essential for plant resistance to pathogens. Besides oxylipins and unsaturated fatty acids known to play important signaling functions during plant-pathogen interactions, the very long chain fatty acid (VLCFA) biosynthesis pathway has been recently associated to plant defense through different aspects. VLCFAs are indeed required for the biosynthesis of the plant cuticle and the generation of sphingolipids. Elucidation of the roles of these lipids in biotic stress responses is the result of the use of genetic approaches together with the identification of the genes/proteins involved in their biosynthesis. This review focuses on recent observations which revealed the complex function of the cuticle and cuticle-derived signals, and the key role of sphingolipids as bioactive molecules involved in signal transduction and cell death regulation during plant-pathogen interactions. PMID:19649180

  6. The orosensory recognition of long-chain fatty acids in rats.

    PubMed

    Tsuruta, M; Kawada, T; Fukuwatari, T; Fushiki, T

    1999-04-01

    To determine the selectivity of long-chain fatty acid (LCFA) in the oral cavity, short-term (5 min) two-bottle tests were conducted in rats. Fifteen male Wistar rats were given oleic acid, linoleic acid, linolenic acid, and their derivatives. All compounds used were 99% pure. The concentration of test fluids was made 1% in 0.3% xanthan gum to minimize postingestive and textural effects. The rats preferred LCFA fluids to the control of 0.3% xanthan gum solution. The preference order of LCFA was linolenic acid > linoleic acid > oleic acid. Four LCFA derivatives (methyl oleate, oleyl alcohol, methyl linoleate, and linolyl alcohol), triolein, and capric acid were not preferred to LCFA, but LCFA derivatives were preferred to the control of xanthan gum solution. These studies suggest that rats select LCFA from olfactory or gustatory cues that are related to both the carbon chain and carboxylate group. PMID:10336155

  7. Aggregation behavior of long-chain piperidinium ionic liquids in ethylammonium nitrate.

    PubMed

    Dai, Caili; Du, Mingyong; Liu, Yifei; Wang, Shilu; Zhao, Jianhui; Chen, Ang; Peng, Dongxu; Zhao, Mingwei

    2014-01-01

    Micelles formed by the long-chain piperidinium ionic liquids (ILs) N-alkyl-N-methylpiperidinium bromide of general formula CnPDB (n = 12, 14, 16) in ethylammonium nitrate (EAN) were investigated through surface tension and dissipative particle dynamics (DPD) simulations. Through surface tension measurements, the critical micelle concentration (cmc), the effectiveness of surface tension reduction (Πcmc), the maximum excess surface concentration (Гmax) and the minimum area occupied per surfactant molecule (Amin) can be obtained. A series of thermodynamic parameters (DG0 m, DH0 m and DS0 m) of micellization can be calculated and the results showed that the micellization was entropy-driven. In addition, the DPD simulation was performed to simulate the whole aggregation process behavior to better reveal the micelle formation process. PMID:25474288

  8. Long-chain acyl-homoserine lactones from Methylobacterium mesophilicum: synthesis and absolute configuration.

    PubMed

    Pomini, Armando M; Cruz, Pedro L R; Gai, Cláudia; Araújo, Welington L; Marsaioli, Anita J

    2009-12-01

    The acyl-homoserine lactones (acyl-HSLs) produced by Methylobacterium mesophilicum isolated from orange trees infected with the citrus variegated chlorosis (CVC) disease have been studied, revealing the occurrence of six long-chain acyl-HSLs, i.e., the saturated homologues (S)-N-dodecanoyl (1) and (S)-N-tetradecanoyl-HSL (5), the uncommon odd-chain N-tridecanoyl-HSL (3), the new natural product (S)-N-(2E)-dodecenoyl-HSL (2), and the rare unsaturated homologues (S)-N-(7Z)-tetradecenoyl (4) and (S)-N-(2E,7Z)-tetradecadienyl-HSL (6). The absolute configurations of all HSLs were determined as 3S. Compounds 2 and 6 were synthesized for the first time. Antimicrobial assays with synthetic acyl-HSLs against Gram-positive bacterial endophytes co-isolated with M. mesophilicum from CVC-infected trees revealed low or no antibacterial activity. PMID:19919062

  9. Two novel COLVI long chains in zebrafish that are essential for muscle development.

    PubMed

    Ramanoudjame, Laetitia; Rocancourt, Claire; Lainé, Jeanne; Klein, Arnaud; Joassard, Lucette; Gartioux, Corine; Fleury, Marjory; Lyphout, Laura; Kabashi, Edor; Ciura, Sorana; Cousin, Xavier; Allamand, Valérie

    2015-12-01

    Collagen VI (COLVI), a protein ubiquitously expressed in connective tissues, is crucial for structural integrity, cellular adhesion, migration and survival. Six different genes are recognized in mammalians, encoding six COLVI-chains that assemble as two 'short' (α1, α2) and one 'long' chain (theoretically any one of α3-6). In humans, defects in the most widely expressed heterotrimer (α123), due to mutations in the COL6A1-3 genes, cause a heterogeneous group of neuromuscular disorders, collectively termed COLVI-related muscle disorders. Little is known about the function(s) of the recently described α4-6 chains and no mutations have been detected yet. In this study, we characterized two novel COLVI long chains in zebrafish that are most homologous to the mammalian α4 chain; therefore, we named the corresponding genes col6a4a and col6a4b. These orthologues represent ancestors of the mammalian Col6a4-6 genes. By in situ hybridization and RT-qPCR, we unveiled a distinctive expression kinetics for col6a4b, compared with the other col6a genes. Using morpholino antisense oligonucleotides targeting col6a4a, col6a4b and col6a2, we modelled partial and complete COLVI deficiency, respectively. All morphant embryos presented altered muscle structure and impaired motility. While apoptosis was not drastically increased, autophagy induction was defective in all morphants. Furthermore, motoneuron axon growth was abnormal in these morphants. Importantly, some phenotypical differences emerged between col6a4a and col6a4b morphants, suggesting only partial functional redundancy. Overall, our results further confirm the importance of COLVI in zebrafish muscle development and may provide important clues for potential human phenotypes associated with deficiency of the recently described COLVI-chains. PMID:26362255

  10. Significance of long-chain polyunsaturated fatty acids (PUFAs) for the development and behaviour of children.

    PubMed

    Schuchardt, Jan Philipp; Huss, Michael; Stauss-Grabo, Manuela; Hahn, Andreas

    2010-02-01

    omega-6 and omega-3 polyunsaturated fatty acids (PUFAs) play a central role in the normal development and functioning of the brain and central nervous system. Long-chain PUFAs (LC-PUFAs) such as eicosapentaenoic acid (EPA, C20:5omega-3), docosahexaenoic acid (DHA, C22:6omega-3) and arachidonic acid (AA, C20:4omega-6), in particular, are involved in numerous neuronal processes, ranging from effects on membrane fluidity to gene expression regulation. Deficiencies and imbalances of these nutrients, not only during the developmental phase but throughout the whole life span, have significant effects on brain function. Numerous observational studies have shown a link between childhood developmental disorders and omega-6:omega-3 fatty acid imbalances. For instance, neurocognitive disorders such as attention-deficit hyperactivity disorder (ADHD), dyslexia, dyspraxia and autism spectrum disorders are often associated with a relative lack of omega-3 fatty acids. In addition to a high omega-6 fatty acid intake and, in many cases, an insufficient supply of omega-3 fatty acids among the population, evidence is increasing to suggest that PUFA metabolism can be impaired in individuals with ADHD. In this context, PUFA imbalances are being discussed as potential risk factors for neurodevelopmental disorders. Another focus is whether the nutritive PUFA requirements-especially long-chain omega-3 fatty acid requirements-are higher among some individuals. Meanwhile, several controlled studies investigated the clinical benefits of LC-PUFA supplementation in affected children and adolescents, with occasionally conflicting results. PMID:19672626

  11. Biodiscovery of new Australian thraustochytrids for production of biodiesel and long-chain omega-3 oils.

    PubMed

    Lee Chang, Kim Jye; Dunstan, Graeme A; Abell, Guy C J; Clementson, Lesley A; Blackburn, Susan I; Nichols, Peter D; Koutoulis, Anthony

    2012-03-01

    Heterotrophic growth of thraustochytrids has potential in co-producing a feedstock for biodiesel and long-chain (LC, ≥C(20)) omega-3 oils. Biodiscovery of thraustochytrids from Tasmania (temperate) and Queensland (tropical), Australia, covered a biogeographic range of habitats including fresh, brackish, and marine waters. A total of 36 thraustochytrid strains were isolated and separated into eight chemotaxonomic groups (A-H) based on fatty acid (FA) and sterol composition which clustered closely with four different genera obtained by 18S rDNA molecular identification. Differences in the relative proportions (%FA) of long-chain C(20), C(22), omega-3, and omega-6 polyunsaturated fatty acids (PUFA), including docosahexaenoic acid (DHA), docosapentaenoic acid, arachidonic acid, eicosapentaenoic acid (EPA), and saturated FA, as well as the presence of odd-chain PUFA (OC-PUFA) were the major factors influencing the separation of these groups. OC-PUFA were detected in temperate strains of groups A, B, and C (Schizochytrium and Thraustochytrium). Group D (Ulkenia) had high omega-3 LC-PUFA (53% total fatty acids (TFA)) and EPA up to 11.2% TFA. Strains from groups E and F (Aurantiochytrium) contained DHA levels of 50-61% TFA after 7 days of growth in basal medium at 20 °C. Groups G and H (Aurantiochytrium) strains had high levels of 15:0 (20-30% TFA) and the sum of saturated FA was in the range of 32-51%. β,β-Carotene, canthaxanthin, and astaxanthin were identified in selected strains. Phylogenetic and chemotaxonomic groupings demonstrated similar patterns for the majority of strains. Our results demonstrate the potential of these new Australian thraustochytrids for the production of biodiesel in addition to omega-3 LC-PUFA-rich oils. PMID:22252264

  12. Biology, ecology, and biotechnological applications of anaerobic bacteria adapted to environmental stresses in temperature, pH, salinity, or substrates.

    PubMed Central

    Lowe, S E; Jain, M K; Zeikus, J G

    1993-01-01

    Anaerobic bacteria include diverse species that can grow at environmental extremes of temperature, pH, salinity, substrate toxicity, or available free energy. The first evolved archaebacterial and eubacterial species appear to have been anaerobes adapted to high temperatures. Thermoanaerobes and their stable enzymes have served as model systems for basic and applied studies of microbial cellulose and starch degradation, methanogenesis, ethanologenesis, acetogenesis, autotrophic CO2 fixation, saccharidases, hydrogenases, and alcohol dehydrogenases. Anaerobes, unlike aerobes, appear to have evolved more energy-conserving mechanisms for physiological adaptation to environmental stresses such as novel enzyme activities and stabilities and novel membrane lipid compositions and functions. Anaerobic syntrophs do not have similar aerobic bacterial counterparts. The metabolic end products of syntrophs are potent thermodynamic inhibitors of energy conservation mechanisms, and they require coordinated consumption by a second partner organism for species growth. Anaerobes adapted to environmental stresses and their enzymes have biotechnological applications in organic waste treatment systems and chemical and fuel production systems based on biomass-derived substrates or syngas. These kinds of anaerobes have only recently been examined by biologists, and considerably more study is required before they are fully appreciated by science and technology. Images PMID:8336675

  13. BMI Affects the Relationship between Long Chain N-3 Polyunsaturated Fatty Acid Intake and Stroke Risk: a Meta-Analysis.

    PubMed

    Cheng, Pengfei; Huang, Wen; Bai, Shunjie; Wu, Yu; Yu, Jia; Zhu, Xiaofeng; Qi, Zhiguo; Shao, Weihua; Xie, Peng

    2015-01-01

    We performed a meta-analysis to clarify the relationship between long chain n-3 polyunsaturated fatty acid (PUFA) intake and stroke risk. Relevant studies were identified by searching online databases through May 2015. Log relative risks (RRs) of the highest versus the lowest for cohort studies were weighed by the inverse variance method to obtain pooled RRs. Fourteen prospective cohort studies including 514,483 individuals and 9,065 strokes were included. The pooled RR of overall stroke risk for long chain n-3 PUFA intake was 0.87 [95% confidence interval (CI), 0.79-0.95]. Stratification analysis showed that higher long chain n-3 PUFAs intake was associated with reduced fatal stroke risk (RR = 0.84; 95% CI, 0.73-0.97), reduced stroke risk for BMI < 24 (RR = 0.86; 95% CI, 0.75-0.98) and reduced stroke risk for females (RR = 0.81; 95% CI, 0.71-0.92), but was not associated with stroke risk for either BMI ≥ 24 or men. This meta-analysis reveals that higher long chain n-3 PUFA intake is inversely associated with risk of stroke morbidity and mortality with BMI and sex as key factors influencing this risk. Individuals should be encouraged to manage their body weight while increasing their intake of long chain n-3 PUFAs. PMID:26369699

  14. Biosynthesis of triacylglycerols containing very long chain monounsaturated acyl moieties in developing seeds. [Lunaria annua L. ; Sinapis alba L

    SciTech Connect

    Fehling, E.; Murphy, D.J.; Mukherjee, K.D. )

    1990-10-01

    Particulate (15,000g) fractions from developing seeds of honesty (Lunaria annua L.) and mustard (Sinapis alba L.) synthesize radioactive very long chain monounsaturated fatty acids (gadoleic, erucic, and nervonic) from (1-{sup 14}C)oleoyl-CoA and malonyl-CoA or from oleoyl-CoA and (2-{sup 14}C)malonyl-CoA. The very long chain monounsaturated fatty acids are rapidly channeled to triacylglycerols and other acyl lipids without intermediate accumulation of their CoA thioesters. When (1-{sup 14}C)oleoyl-CoA is used as the radioactive substrate, phosphatidylcholines and other phospholipids are most extensively radiolabeled by oleoyl moieties rather than by very long chain monounsaturated acyl moieties. When (2-{sup 14}C)malonyl-CoA is used as the radioactive substrate, no radioactive oleic acid is formed and the newly synthesized very long chain monounsaturated fatty acids are extensively incorporated into phosphatidylcholines and other phospholipids as well as triacylglycerols. The pattern of labeling of the key intermediates of the Kennedy pathway, e.g. lysophosphatidic acids, phosphatidic acids, and diacylglycerols by the newly synthesized very long chain monounsaturated fatty acids is consistent with the operation of this pathway in the biosynthesis of triacylglycerols.

  15. BMI Affects the Relationship between Long Chain N-3 Polyunsaturated Fatty Acid Intake and Stroke Risk: a Meta-Analysis

    PubMed Central

    Cheng, Pengfei; Huang, Wen; Bai, Shunjie; Wu, Yu; Yu, Jia; Zhu, Xiaofeng; Qi, Zhiguo; Shao, Weihua; Xie, Peng

    2015-01-01

    We performed a meta-analysis to clarify the relationship between long chain n-3 polyunsaturated fatty acid (PUFA) intake and stroke risk. Relevant studies were identified by searching online databases through May 2015. Log relative risks (RRs) of the highest versus the lowest for cohort studies were weighed by the inverse variance method to obtain pooled RRs. Fourteen prospective cohort studies including 514,483 individuals and 9,065 strokes were included. The pooled RR of overall stroke risk for long chain n-3 PUFA intake was 0.87 [95% confidence interval (CI), 0.79–0.95]. Stratification analysis showed that higher long chain n-3 PUFAs intake was associated with reduced fatal stroke risk (RR = 0.84; 95% CI, 0.73–0.97), reduced stroke risk for BMI < 24 (RR = 0.86; 95% CI, 0.75–0.98) and reduced stroke risk for females (RR = 0.81; 95% CI, 0.71–0.92), but was not associated with stroke risk for either BMI ≥ 24 or men. This meta-analysis reveals that higher long chain n-3 PUFA intake is inversely associated with risk of stroke morbidity and mortality with BMI and sex as key factors influencing this risk. Individuals should be encouraged to manage their body weight while increasing their intake of long chain n-3 PUFAs. PMID:26369699

  16. Microbial population dynamics during start-up and overload conditions of anaerobic digesters treating municipal solid waste and sewage sludge.

    PubMed

    McMahon, Katherine D; Zheng, Dandan; Stams, Alfons J M; Mackie, Roderick I; Raskin, Lutgarde

    2004-09-30

    Microbial population dynamics were investigated during start-up and during periods of overload conditions in anaerobic co-digesters treating municipal solid waste and sewage sludge. Changes in community structure were monitored using ribosomal RNA-based oligonucleotide probe hybridization to measure the abundance of syntrophic propionate-oxidizing bacteria (SPOB), saturated fatty acid-beta-oxidizing syntrophs (SFAS), and methanogens. These changes were linked to traditional performance parameters such as biogas production and volatile fatty acid (VFA) concentrations. Digesters with high levels of Archaea started up successfully. Methanosaeta concilii was the dominant aceticlastic methanogen in these systems. In contrast, digesters that experienced a difficult start-up period had lower levels of Archaea with proportionally more abundant Methanosarcina spp. Syntrophic propionate-oxidizing bacteria and saturated fatty acid-beta-oxidizing syntrophs were present at low levels in all digesters, and SPOB appeared to play a role in stabilizing propionate levels during start-up of one digester. Digesters with a history of poor performance tolerated a severe organic overload event better than digesters that had previously performed well. It is hypothesized that higher levels of SPOB and SFAS and their methanogenic partners in previously unstable digesters are responsible for this behavior. PMID:15334409

  17. Communities stimulated with ethanol to perform direct interspecies electron transfer for syntrophic metabolism of propionate and butyrate.

    PubMed

    Zhao, Zhiqiang; Zhang, Yaobin; Yu, Qilin; Dang, Yan; Li, Yang; Quan, Xie

    2016-10-01

    Direct interspecies electron transfer (DIET) has been considered as an alternative to interspecies H2 transfer (IHT) for syntrophic metabolism, but the microorganisms capable of metabolizing the key intermediates, such as propionate and butyrate, via DIET have yet to be described. A strategy of culturing the enrichments with ethanol as a DIET substrate to stimulate the communities for the syntrophic metabolism of propionate and/or butyrate was proposed in this study. The results showed that the syntrophic propionate and/or butyrate degradation was significantly improved in the ethanol-stimulated reactor when propionate/butyrate was the sole carbon source. The conductivity of the ethanol-stimulated enrichments was as 5 folds (for propionate)/76 folds (for butyrate) as that of the traditional enrichments (never ethanol fed). Microbial community analysis revealed that Geobacter species known to proceed DIET were only detected in the ethanol-stimulated enrichments. Together with the significant increase of Methanosaeta and Methanosarcina species in these enrichments, the potential DIET between Geobacter and Methanosaeta or Methanosarcina species might be established to improve the syntrophic propionate and/or butyrate degradation. Further experiments demonstrated that granular activated carbon (GAC) could improve the syntrophic metabolism of propionate and/or butyrate of the ethanol-stimulated enrichments, while almost no effects on the traditional enrichments. Also, the high H2 partial pressure could inhibit the syntrophic propionate and/or butyrate degradation of the traditional enrichments, but its effect on that of the ethanol-stimulated enrichments was negligible. PMID:27403870

  18. ANAEROBIC BIODEGRADATION OF VEGETABLE OIL AND ITS METABOLIC INTERMEDIATES IN OIL-ENRICHED FRESHWATER SEDIMENTS

    EPA Science Inventory

    Anaerobic biodegradation of vegetable oil in freshwater sediments is strongly inhibited by high concentrations of oil, but the presence of ferric hydroxide relieves the inhibition. The effect of ferric hydroxide is not due to physical or chemical interactions with long-chain fatt...

  19. Identification and characterization of a long-chain fatty acid transporter in the sophorolipid-producing strain Starmerella bombicola.

    PubMed

    Li, Jiashan; Xia, Chengqiang; Fang, Xiaoran; Xue, Haizhao; Song, Xin

    2016-08-01

    The sophorolipid-producing strain Starmerella bombicola CGMCC 1576 has a remarkable ability to produce sophorolipids (SLs) under the acidic and lactonic forms with almost equal proportion. In this study, we found the gene encoding for the long-chain acyl-CoA synthetase (ALCS). This enzyme was putatively identified as a membrane-bound long-chain fatty acid transport protein and contributed to the uptake of long-chain fatty acids. Disruption of the alcs gene resulted in an impaired growth of the alcs-deleted mutant in minimal media containing different fatty acids (C12:0, C14:0, C16:0, C18:0, C22:0, and C24:0) as the sole carbon source and led to a dramatic decrease in the uptake of the fluorescent-tagged long-chain fatty acid analogue-boron dipyrromethene difluoride dodecanoic acid (BODIPY-3823). The absence of this alcs gene caused obvious phenotype changes. Compared with the wild-type strain, the yield and compositions of the SLs produced by the gene-deleted mutant of ∆alcs::six showed almost no lactonic form of SLs, and the acidic SLs were composed of medium-chain. The ALCS enzyme was heterologously expressed in Escherichia coli JM109 (DE3) with pMAL-c2x-alcs. The enzyme was purified through a maltose-binding protein (MBP) affinity chromatography column and was confirmed to be homogeneous by SDS-PAGE. The recombinant enzyme could catalyze the formation of the long-chain acyl-CoA when the long-chain fatty acids and the coenzyme A were used as substrates. PMID:27183996

  20. Management and outcome in 75 individuals with long-chain fatty acid oxidation defects: results from a workshop.

    PubMed

    Spiekerkoetter, U; Lindner, M; Santer, R; Grotzke, M; Baumgartner, M R; Boehles, H; Das, A; Haase, C; Hennermann, J B; Karall, D; de Klerk, H; Knerr, I; Koch, H G; Plecko, B; Röschinger, W; Schwab, K O; Scheible, D; Wijburg, F A; Zschocke, J; Mayatepek, E; Wendel, U

    2009-08-01

    At present, long-chain fatty acid oxidation (FAO) defects are diagnosed in a number of countries by newborn screening using tandem mass spectrometry. In the majority of cases, affected newborns are asymptomatic at time of diagnosis and acute clinical presentations can be avoided by early preventive measures. Because evidence-based studies on management of long-chain FAO defects are lacking, we carried out a retrospective analysis of 75 patients from 18 metabolic centres in Germany, Switzerland, Austria and the Netherlands with special regard to treatment and disease outcome. Dietary treatment is effective in many patients and can prevent acute metabolic derangements and prevent or reverse severe long-term complications such as cardiomyopathy. However, 38% of patients with very long-chain acyl-CoA dehydrogenase (VLCAD) deficiency had intermittent muscle weakness and pain despite adhering to therapy. Seventy-six per cent of patients with disorders of the mitochondrial trifunctional protein (TFP)-complex including long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) deficiency, had long-term myopathic symptoms. Of these, 21% had irreversible peripheral neuropathy and 43% had retinopathy. The main principle of treatment was a fat-reduced and fat-modified diet. Fat restriction differed among patients with different enzyme defects and was strictest in disorders of the TFP-complex. Patients with a medium-chain fat-based diet received supplementation of essential long-chain fatty acids. l-Carnitine was supplemented in about half of the patients, but in none of the patients with VLCAD deficiency identified by newborn screening. In summary, in this cohort the treatment regimen was adapted to the severity of the underlying enzyme defect and thus differed among the group of long-chain FAO defects. PMID:19399638

  1. Microbial community dynamics in batch high-solid anaerobic digestion of food waste under mesophilic conditions.

    PubMed

    Yi, Jing; Dong, Bin; Xue, Yonggang; Li, Ning; Gao, Peng; Zhao, Yuxin; Dai, Lingling; Dai, Xiaohu

    2014-02-28

    Microbial community shifts, associated with performance data, were investigated in an anaerobic batch digester treating high-solid food waste under mesophilic conditions using, a combination of molecular techniques and chemical analysis methods. The batch process was successfully operated with an organic removal efficiency of 44.5% associated with a biogas yield of 0.82 L/g VSremoval. Microbial community structures were examined by denaturing gel gradient electrophoresis. Clostridium and Symbiobacterium organisms were suggested to be mainly responsible for the organic matter catabolism in hydrolysis and acidogenesis reactions. The dynamics of archaeal and methanogenic populations were monitored using real-time PCR targeting 16S rRNA genes. Methanosarcina was the predominant methanogen, suggesting that the methanogenesis took place mainly via an aceticlastic pathway. Hydrogenotrophic methanogens were also supported in high-solid anaerobic digestion of food waste through syntrophism with syntrophic bacterium. Microbial community shifts showed good agreement with the performance parameters in anaerobic digestion, implying the possibility of diagnosing a high-solid anaerobic digestion process by monitoring microbial community shifts. On the other hand, the batch results could be relevant to the start-up period of a continuous system and could also provide useful information to set up a continuous operation. PMID:24150490

  2. Microscale and nanoscale hierarchical structured mesh films with superhydrophobic and superoleophilic properties induced by long-chain fatty acids

    NASA Astrophysics Data System (ADS)

    Wang, Shutao; Song, Yanlin; Jiang, Lei

    2007-01-01

    Inspired by the lotus effect, we fabricate new microscale and nanoscale hierarchical structured copper mesh films by a simple electrochemical deposition. After modification of the long-chain fatty acid monolayer, these films show superhydrophobic and superoleophilic properties, which could be used for the effective separation of oil and water. The length of the fatty acid chain strongly influences the surface wettability of as-prepared films. It is confirmed that the cooperative effect of the hierarchical structure of the copper film and the nature of the long-chain fatty acid contribute to this unique surface wettability.

  3. Quantification of syntrophic acetate-oxidizing microbial communities in biogas processes.

    PubMed

    Westerholm, Maria; Dolfing, Jan; Sherry, Angela; Gray, Neil D; Head, Ian M; Schnürer, Anna

    2011-08-01

    Changes in communities of syntrophic acetate-oxidizing bacteria (SAOB) and methanogens caused by elevated ammonia levels were quantified in laboratory-scale methanogenic biogas reactors operating at moderate temperature (37°C) using quantitative polymerase chain reaction (qPCR). The experimental reactor was subjected to gradually increasing ammonia levels (0.8-6.9 g NH4 (+) -N l(-1) ), whereas the level of ammonia in the control reactor was kept low (0.65-0.90 g NH4 (+) -N l(-1) ) during the entire period of operation (660 days). Acetate oxidation in the experimental reactor, indicated by increased production of (14) CO2 from acetate labelled in the methyl carbon, occurred when ammonia levels reached 5.5 and 6.9 g NH4 (+) -N l(-1) . Syntrophic acetate oxidizers targeted by newly designed qPCR primers were Thermacetogenium phaeum, Clostridium ultunense, Syntrophaceticus schinkii and Tepidanaerobacter acetatoxydans. The results showed a significant increase in abundance of all these bacteria except T. phaeum in the ammonia-stressed reactor, coincident with the shift to syntrophic acetate oxidation. As the abundance of the bacteria increased, a simultaneous decrease was observed in the abundance of aceticlastic methanogens from the families Methanosaetaceae and Methanosarcinaceae. qPCR analyses of sludge from two additional high ammonia processes, in which methane production from acetate proceeded through syntrophic acetate oxidation (reactor SB) or through aceticlastic degradation (reactor DVX), demonstrated that SAOB were significantly more abundant in the SB reactor than in the DVX reactor. PMID:23761313

  4. Quantification of syntrophic acetate-oxidizing microbial communities in biogas processes

    PubMed Central

    Westerholm, Maria; Dolfing, Jan; Sherry, Angela; Gray, Neil D; Head, Ian M; Schnürer, Anna

    2011-01-01

    Changes in communities of syntrophic acetate-oxidizing bacteria (SAOB) and methanogens caused by elevated ammonia levels were quantified in laboratory-scale methanogenic biogas reactors operating at moderate temperature (37°C) using quantitative polymerase chain reaction (qPCR). The experimental reactor was subjected to gradually increasing ammonia levels (0.8–6.9 g NH4+-N l−1), whereas the level of ammonia in the control reactor was kept low (0.65–0.90 g NH4+-N l−1) during the entire period of operation (660 days). Acetate oxidation in the experimental reactor, indicated by increased production of 14CO2 from acetate labelled in the methyl carbon, occurred when ammonia levels reached 5.5 and 6.9 g NH4+-N l−1. Syntrophic acetate oxidizers targeted by newly designed qPCR primers were Thermacetogenium phaeum, Clostridium ultunense, Syntrophaceticus schinkii and Tepidanaerobacter acetatoxydans. The results showed a significant increase in abundance of all these bacteria except T. phaeum in the ammonia-stressed reactor, coincident with the shift to syntrophic acetate oxidation. As the abundance of the bacteria increased, a simultaneous decrease was observed in the abundance of aceticlastic methanogens from the families Methanosaetaceae and Methanosarcinaceae. qPCR analyses of sludge from two additional high ammonia processes, in which methane production from acetate proceeded through syntrophic acetate oxidation (reactor SB) or through aceticlastic degradation (reactor DVX), demonstrated that SAOB were significantly more abundant in the SB reactor than in the DVX reactor. PMID:23761313

  5. Variation among Desulfovibrio species in electron transfer systems used for syntrophic growth.

    PubMed

    Meyer, Birte; Kuehl, Jennifer; Deutschbauer, Adam M; Price, Morgan N; Arkin, Adam P; Stahl, David A

    2013-03-01

    Mineralization of organic matter in anoxic environments relies on the cooperative activities of hydrogen producers and consumers linked by interspecies electron transfer in syntrophic consortia that may include sulfate-reducing species (e.g., Desulfovibrio). Physiological differences and various gene repertoires implicated in syntrophic metabolism among Desulfovibrio species suggest considerable variation in the biochemical basis of syntrophy. In this study, comparative transcriptional and mutant analyses of Desulfovibrio alaskensis strain G20 and Desulfovibrio vulgaris strain Hildenborough growing syntrophically with Methanococcus maripaludis on lactate were used to develop new and revised models for their alternative electron transfer and energy conservation systems. Lactate oxidation by strain G20 generates a reduced thiol-disulfide redox pair(s) and ferredoxin that are energetically coupled to H(+)/CO(2) reduction by periplasmic formate dehydrogenase and hydrogenase via a flavin-based reverse electron bifurcation process (electron confurcation) and a menaquinone (MQ) redox loop-mediated reverse electron flow involving the membrane-bound Qmo and Qrc complexes. In contrast, strain Hildenborough uses a larger number of cytoplasmic and periplasmic proteins linked in three intertwining pathways to couple H(+) reduction to lactate oxidation. The faster growth of strain G20 in coculture is associated with a kinetic advantage conferred by the Qmo-MQ-Qrc loop as an electron transfer system that permits higher lactate oxidation rates under elevated hydrogen levels (thereby enhancing methanogenic growth) and use of formate as the main electron-exchange mediator (>70% electron flux), as opposed to the primarily hydrogen-based exchange by strain Hildenborough. This study further demonstrates the absence of a conserved gene core in Desulfovibrio that would determine the ability for a syntrophic lifestyle. PMID:23264581

  6. Flexibility of syntrophic enzyme systems in Desulfovibrio species ensures their adaptation capability to environmental changes.

    PubMed

    Meyer, Birte; Kuehl, Jennifer V; Deutschbauer, Adam M; Arkin, Adam P; Stahl, David A

    2013-11-01

    The mineralization of organic matter in anoxic environments relies on the cooperative activities of hydrogen producers and consumers obligately linked by interspecies metabolite exchange in syntrophic consortia that may include sulfate reducing species such as Desulfovibrio. To evaluate the metabolic flexibility of syntrophic Desulfovibrio to adapt to naturally fluctuating methanogenic environments, we studied Desulfovibrio alaskensis strain G20 grown in chemostats under respiratory and syntrophic conditions with alternative methanogenic partners, Methanococcus maripaludis and Methanospirillum hungatei, at different growth rates. Comparative whole-genome transcriptional analyses, complemented by G20 mutant strain growth experiments and physiological data, revealed a significant influence of both energy source availability (as controlled by dilution rate) and methanogen on the electron transfer systems, ratios of interspecies electron carriers, energy generating systems, and interspecies physical associations. A total of 68 genes were commonly differentially expressed under syntrophic versus respiratory lifestyle. Under low-energy (low-growth-rate) conditions, strain G20 further had the capacity to adapt to the metabolism of its methanogenic partners, as shown by its differing gene expression of enzymes involved in the direct metabolic interactions (e.g., periplasmic hydrogenases) and the ratio shift in electron carriers used for interspecies metabolite exchange (hydrogen/formate). A putative monomeric [Fe-Fe] hydrogenase and Hmc (high-molecular-weight-cytochrome c3) complex-linked reverse menaquinone (MQ) redox loop become increasingly important for the reoxidation of the lactate-/pyruvate oxidation-derived redox pair, DsrC(red) and Fd(red), relative to the Qmo-MQ-Qrc (quinone-interacting membrane-bound oxidoreductase; quinone-reducing complex) loop. Together, these data underscore the high enzymatic and metabolic adaptive flexibility that likely sustains

  7. Flexibility of Syntrophic Enzyme Systems in Desulfovibrio Species Ensures Their Adaptation Capability to Environmental Changes

    PubMed Central

    Meyer, Birte; Kuehl, Jennifer V.; Deutschbauer, Adam M.; Arkin, Adam P.

    2013-01-01

    The mineralization of organic matter in anoxic environments relies on the cooperative activities of hydrogen producers and consumers obligately linked by interspecies metabolite exchange in syntrophic consortia that may include sulfate reducing species such as Desulfovibrio. To evaluate the metabolic flexibility of syntrophic Desulfovibrio to adapt to naturally fluctuating methanogenic environments, we studied Desulfovibrio alaskensis strain G20 grown in chemostats under respiratory and syntrophic conditions with alternative methanogenic partners, Methanococcus maripaludis and Methanospirillum hungatei, at different growth rates. Comparative whole-genome transcriptional analyses, complemented by G20 mutant strain growth experiments and physiological data, revealed a significant influence of both energy source availability (as controlled by dilution rate) and methanogen on the electron transfer systems, ratios of interspecies electron carriers, energy generating systems, and interspecies physical associations. A total of 68 genes were commonly differentially expressed under syntrophic versus respiratory lifestyle. Under low-energy (low-growth-rate) conditions, strain G20 further had the capacity to adapt to the metabolism of its methanogenic partners, as shown by its differing gene expression of enzymes involved in the direct metabolic interactions (e.g., periplasmic hydrogenases) and the ratio shift in electron carriers used for interspecies metabolite exchange (hydrogen/formate). A putative monomeric [Fe-Fe] hydrogenase and Hmc (high-molecular-weight-cytochrome c3) complex-linked reverse menaquinone (MQ) redox loop become increasingly important for the reoxidation of the lactate-/pyruvate oxidation-derived redox pair, DsrCred and Fdred, relative to the Qmo-MQ-Qrc (quinone-interacting membrane-bound oxidoreductase; quinone-reducing complex) loop. Together, these data underscore the high enzymatic and metabolic adaptive flexibility that likely sustains Desulfovibrio

  8. Variation among Desulfovibrio Species in Electron Transfer Systems Used for Syntrophic Growth

    PubMed Central

    Meyer, Birte; Kuehl, Jennifer; Deutschbauer, Adam M.; Price, Morgan N.; Arkin, Adam P.

    2013-01-01

    Mineralization of organic matter in anoxic environments relies on the cooperative activities of hydrogen producers and consumers linked by interspecies electron transfer in syntrophic consortia that may include sulfate-reducing species (e.g., Desulfovibrio). Physiological differences and various gene repertoires implicated in syntrophic metabolism among Desulfovibrio species suggest considerable variation in the biochemical basis of syntrophy. In this study, comparative transcriptional and mutant analyses of Desulfovibrio alaskensis strain G20 and Desulfovibrio vulgaris strain Hildenborough growing syntrophically with Methanococcus maripaludis on lactate were used to develop new and revised models for their alternative electron transfer and energy conservation systems. Lactate oxidation by strain G20 generates a reduced thiol-disulfide redox pair(s) and ferredoxin that are energetically coupled to H+/CO2 reduction by periplasmic formate dehydrogenase and hydrogenase via a flavin-based reverse electron bifurcation process (electron confurcation) and a menaquinone (MQ) redox loop-mediated reverse electron flow involving the membrane-bound Qmo and Qrc complexes. In contrast, strain Hildenborough uses a larger number of cytoplasmic and periplasmic proteins linked in three intertwining pathways to couple H+ reduction to lactate oxidation. The faster growth of strain G20 in coculture is associated with a kinetic advantage conferred by the Qmo-MQ-Qrc loop as an electron transfer system that permits higher lactate oxidation rates under elevated hydrogen levels (thereby enhancing methanogenic growth) and use of formate as the main electron-exchange mediator (>70% electron flux), as opposed to the primarily hydrogen-based exchange by strain Hildenborough. This study further demonstrates the absence of a conserved gene core in Desulfovibrio that would determine the ability for a syntrophic lifestyle. PMID:23264581

  9. The Staphylococcus aureus Response to Unsaturated Long Chain Free Fatty Acids: Survival Mechanisms and Virulence Implications

    PubMed Central

    Kenny, John G.; Ward, Deborah; Josefsson, Elisabet; Jonsson, Ing-Marie; Hinds, Jason; Rees, Huw H.; Lindsay, Jodi A.; Tarkowski, Andrej; Horsburgh, Malcolm J.

    2009-01-01

    Staphylococcus aureus is an important human commensal and opportunistic pathogen responsible for a wide range of infections. Long chain unsaturated free fatty acids represent a barrier to colonisation and infection by S. aureus and act as an antimicrobial component of the innate immune system where they are found on epithelial surfaces and in abscesses. Despite many contradictory reports, the precise anti-staphylococcal mode of action of free fatty acids remains undetermined. In this study, transcriptional (microarrays and qRT-PCR) and translational (proteomics) analyses were applied to ascertain the response of S. aureus to a range of free fatty acids. An increase in expression of the σB and CtsR stress response regulons was observed. This included increased expression of genes associated with staphyloxanthin synthesis, which has been linked to membrane stabilisation. Similarly, up-regulation of genes involved in capsule formation was recorded as were significant changes in the expression of genes associated with peptidoglycan synthesis and regulation. Overall, alterations were recorded predominantly in pathways involved in cellular energetics. In addition, sensitivity to linoleic acid of a range of defined (sigB, arcA, sasF, sarA, agr, crtM) and transposon-derived mutants (vraE, SAR2632) was determined. Taken together, these data indicate a common mode of action for long chain unsaturated fatty acids that involves disruption of the cell membrane, leading to interference with energy production within the bacterial cell. Contrary to data reported for other strains, the clinically important EMRSA-16 strain MRSA252 used in this study showed an increase in expression of the important virulence regulator RNAIII following all of the treatment conditions tested. An adaptive response by S. aureus of reducing cell surface hydrophobicity was also observed. Two fatty acid sensitive mutants created during this study were also shown to diplay altered pathogenesis as assessed

  10. Anaerobic bacteria

    MedlinePlus

    Brook I, Goldstein EJ. Diseases caused by non-spore forming anaerobic bacteria. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine . 25th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 297. Stedman's Online ...

  11. High contents of very long-chain polyunsaturated fatty acids in different moss species.

    PubMed

    Beike, Anna K; Jaeger, Carsten; Zink, Felix; Decker, Eva L; Reski, Ralf

    2014-02-01

    Polyunsaturated fatty acids (PUFAs) are important cellular compounds with manifold biological functions. Many PUFAs are essential for the human diet and beneficial for human health. In this study, we report on the high amounts of very long-chain (vl) PUFAs (≥C₂₀) such as arachidonic acid (AA) in seven moss species. These species were established in axenic in vitro culture, as a prerequisite for comparative metabolic studies under highly standardized laboratory conditions. In the model organism Physcomitrella patens, tissue-specific differences in the fatty acid compositions between the filamentous protonema and the leafy gametophores were observed. These metabolic differences correspond with differential gene expression of fatty acid desaturase (FADS)-encoding genes in both developmental stages, as determined via microarray analyses. Depending on the developmental stage and the species, AA amounts for 6-31 %, respectively, of the total fatty acids. Subcellular localization of the corresponding FADS revealed the endoplasmic reticulum as the cellular compartment for AA synthesis. Our results show that vlPUFAs are highly abundant metabolites in mosses. Standardized cultivation techniques using photobioreactors along with the availability of the P. patens genome sequence and the high rate of homologous recombination are the basis for targeted metabolic engineering in moss. The potential of producing vlPUFAs of interest from mosses will be highlighted as a promising area in plant biotechnology. PMID:24170342

  12. Effect of headgroup-substrate interactions on the thermal behavior of long-chain amphiphiles

    NASA Astrophysics Data System (ADS)

    Singla, Saranshu; Zhu, He; Dhinojwala, Ali

    The structure of amphiphilic molecules at liquid/solid and solid/solid interfaces is relevant in understanding lubrication, colloid stabilization, chromatography, and nucleation. Here, we characterize the interfacial structures of long chain amphiphilic molecules with different head groups (OH, COOH, NH2) using interface-sensitive sum frequency generation (SFG) spectroscopy. The behavior of these self-assembled monolayers (SAMs) on sapphire substrate is recorded in situ as a function of temperature (above and below bulk Tm) using SFG. Previous studies using synchrotron X-ray reflectivity and SFG show that the melting point of an ordered hexadecanol monolayer is around 30°C above its bulk Tm. The thermal stability of the monolayer is explained due to strong hydrogen bonding interactions between the head-group and the sapphire substrate. The strength of these hydrogen-bonding interactions between substrate and different head groups is calculated using the Badger-Bauer equation. Below Tm, the ordered monolayer influenced the structure of the interfacial crystalline layer, and the transition from monolayer to the bulk crystalline phases. The results with different head groups will be presented.

  13. Susceptibility of synthetic long-chain alkylbenzenes to degradation in reducing marine sediments.

    PubMed

    Eganhouse, Robert P; Pontolillo, James

    2008-09-01

    Long-chain alkylbenzenes (LCABs) synthesized for production of alkylbenzene sulfonate surfactants have been used as molecular markers of anthropogenic waste for 25 years. Synthetic LCABs comprise two classes, the tetrapropylene-based alkylbenzenes (TABs) and the linear alkylbenzenes (LABs). LABs supplanted TABs in the mid-1960s because of improved biodegradability of their sulfonated analogs. Use of LCABs for molecular stratigraphy depends on their preservation in sediments over decadal time scales. Most laboratory and field studies suggest that LABs degrade rapidly under aerobic conditions but are resistant to degradation when oxygen is absent. However, recent work indicates that LABs may not be as persistent under reducing conditions as previously thought. To assess the potential for degradation of LCABs in reducing sediments, box cores collected in 1992 and 2003 near a submarine wastewater outfall system were analyzed using gas chromatography/mass spectrometry. The TABs were effectively preserved; differences between whole-core inventories were within analytical error. By contrast whole-core inventories of the LABs decreased by about 50-60% during the same time interval. Based on direct comparison of chemical inventories in coeval core sections, LAB transformation rates are estimated at 0.07 +/- 0.01 yr(-1). These results indicate that caution should be exercised when using synthetic LCABs for reconstruction of depositional records. PMID:18800502

  14. A Model for the Interfacial Kinetics of Phospholipase D Activity on Long-Chain Lipids

    PubMed Central

    Majd, Sheereen; Yusko, Erik C.; Yang, Jerry; Sept, David; Mayer, Michael

    2013-01-01

    The membrane-active enzyme phospholipase D (PLD) catalyzes the hydrolysis of the phosphodiester bond in phospholipids and plays a critical role in cell signaling. This catalytic reaction proceeds on lipid-water interfaces and is an example of heterogeneous catalysis in biology. Recently we showed that planar lipid bilayers, a previously unexplored model membrane for these kinetic studies, can be used for monitoring interfacial catalytic reactions under well-defined experimental conditions with chemical and electrical access to both sides of the lipid membrane. Employing an assay that relies on the conductance of the pore-forming peptide gramicidin A to monitor PLD activity, the work presented here reveals the kinetics of hydrolysis of long-chain phosphatidylcholine lipids in situ. We have developed an extension of a basic kinetic model for interfacial catalysis that includes product activation and substrate depletion. This model describes the kinetic behavior very well and reveals two kinetic parameters, the specificity constant and the interfacial quality constant. This approach results in a simple and general model to account for product accumulation in interfacial enzyme kinetics. PMID:23823233

  15. Analysis of Long-Chain Unsaturated Fatty Acids by Ionic Liquid Gas Chromatography.

    PubMed

    Weatherly, Choyce A; Zhang, Ying; Smuts, Jonathan P; Fan, Hui; Xu, Chengdong; Schug, Kevin A; Lang, John C; Armstrong, Daniel W

    2016-02-17

    Four ionic liquid (IL) columns, SLB-IL59, SLB-IL60, SLB-IL65, and SLB-IL111, were evaluated for more rapid analysis or improved resolution of long-chain methyl and ethyl esters of omega-3, omega-6, and additional positional isomeric and stereoisomeric blends of fatty acids found in fish oil, flaxseed oil, and potentially more complicated compositions. The three structurally distinct IL columns provided shorter retention times and more symmetric peak shapes for the fatty acid methyl or ethyl esters than a conventional polyethylene glycol column (PEG), resolving cis- and trans-fatty acid isomers that coeluted on the PEG column. The potential for improved resolution of fatty acid esters is important for complex food and supplement applications, where different forms of fatty acid can be incorporated. Vacuum ultraviolet detection contributed to further resolution for intricate mixtures containing cis- and trans-isomers, as exemplified in a fatty acid blend of shorter chain C18:1 esters with longer chain polyunsaturated fatty acid (PUFA) esters. PMID:26852774

  16. Interdigitation of long-chain sphingomyelin induces coupling of membrane leaflets in a cholesterol dependent manner.

    PubMed

    Róg, Tomasz; Orłowski, Adam; Llorente, Alicia; Skotland, Tore; Sylvänne, Tuulia; Kauhanen, Dimple; Ekroos, Kim; Sandvig, Kirsten; Vattulainen, Ilpo

    2016-02-01

    It has been a long-standing question how the two leaflets in a lipid bilayer modulate each others' physical properties. In this paper, we discuss how this interaction may take place through interdigitation. We use atomistic molecular dynamics simulations to consider asymmetric lipid membrane models whose compositions are based on the lipidomics data determined for exosomes released by PC-3 prostate cancer cells. The simulations show interdigitation to be exceptionally strong for long-chain sphingomyelin (SM) molecules. In asymmetric membranes the amide-linked chain of SM is observed to extend deep into the opposing membrane leaflet. Interestingly, we find that the conformational order of the amide-linked SM chain increases the deeper it penetrates to the opposing leaflet. Analysis of this finding reveals that the amide-linked SM chain interacts favorably with the lipid chains in the opposite leaflet, and that cholesterol modulates the effect of SM interdigitation by influencing the conformational order of lipid hydrocarbon chains in the opposing (cytosolic) leaflet. PMID:26654782

  17. Long-chain fatty acids act as protonophoric uncouplers of oxidative phosphorylation in rat liver mitochondria.

    PubMed

    Schönfeld, P; Schild, L; Kunz, W

    1989-12-01

    The effect of long-chain fatty acids (LCFA) on respiration and transmembrane potential (delta psi) in the resting state, and the rate of delta psi dissipation [d delta psi/dt)i) was investigated with oligomycin-inhibited rat liver mitochondria using succinate (plus rotenone) as substrate. The results obtained were compared with those of classical protonophores such as 2,4-dinitrophenol (DNP) and 4,5,6,7-tetrachloro-2-trifluoromethylbenzimidazole (TTFB). The effects of oleate or palmitate and that of DNP or TTFB on respiration and delta psi can be described by a common force-flow relationship. These facts all in all are not compatible with a decoupler-type uncoupling mechanism of LCFA; still, they indicate that the latter are protonophores. Moreover, the oleate-induced increase in the rate of delta psi dissipation closely correlates with that in respiration, suggesting that the uncoupling activity and the protonophoric activity of LCFA are interrelated. Carboxyatractyloside (CAT) exerted only a small inhibitory effect on oleate-induced respiration and delta psi dissipation, indicating that the adenine nucleotide translocase contributes to the uncoupling effect of LCFA to a minor extent only. Proton transport through the lipid region of the membrane as mediated by permeation of the protonated and deprotonated forms of LCFA is interpreted as the main process of the uncoupling of LCFA. PMID:2556180

  18. A comparison of medium-chain and long-chain triglycerides in surgical patients.

    PubMed

    Jiang, Z M; Zhang, S Y; Wang, X R; Yang, N F; Zhu, Y; Wilmore, D

    1993-02-01

    Available lipid emulsions made from soybean or safflower oil are classified as long-chain triglycerides (LCT). In contrast, medium-chain triglyceride (MCT) emulsions have different physical properties and are metabolized by other biochemical pathways. To compare the differences between these two fat emulsions, the authors studied 12 surgical patients and 6 volunteers. These subjects were randomly assigned to receive parenteral nutrition with MCT or LCT emulsion. Measurement of arterial and venous concentration differences across the forearm demonstrated that muscle utilization was significantly improved with MCT administration. There was also a trend toward improved nitrogen balance in the MCT group, and less weight loss in the postoperative period also was observed in this group. During the fat clearance test, the serum ketone concentrations were significantly higher in the MCT than the LCT group. The improvement in nitrogen retention may be associated with increasing ketone and insulin levels. Fat emulsions containing 50% MCT are safe for use in parenteral nutrition and may provide an alternate fuel that improves protein metabolism. PMID:8439215

  19. Finding long chains in kidney exchange using the traveling salesman problem.

    PubMed

    Anderson, Ross; Ashlagi, Itai; Gamarnik, David; Roth, Alvin E

    2015-01-20

    As of May 2014 there were more than 100,000 patients on the waiting list for a kidney transplant from a deceased donor. Although the preferred treatment is a kidney transplant, every year there are fewer donors than new patients, so the wait for a transplant continues to grow. To address this shortage, kidney paired donation (KPD) programs allow patients with living but biologically incompatible donors to exchange donors through cycles or chains initiated by altruistic (nondirected) donors, thereby increasing the supply of kidneys in the system. In many KPD programs a centralized algorithm determines which exchanges will take place to maximize the total number of transplants performed. This optimization problem has proven challenging both in theory, because it is NP-hard, and in practice, because the algorithms previously used were unable to optimally search over all long chains. We give two new algorithms that use integer programming to optimally solve this problem, one of which is inspired by the techniques used to solve the traveling salesman problem. These algorithms provide the tools needed to find optimal solutions in practice. PMID:25561535

  20. Long Chain Molecules in the Molten State: Surface Adsorption, Near Surface Structure, and Mutual-Diffusion

    NASA Astrophysics Data System (ADS)

    Zhao, Xiaofeng

    1993-01-01

    The surface segregation in a binary mixture of polymer due to surface energy difference or end-grafting is studied. The surface energy difference induced segregation is compared with the mean-field theory. The end-labeling of chains strengthens the ability of the chain to bind to the surface, and the stretching of the end grafted chains is proved to be a controlling fact limiting the brush density. The structure of a chain near a surface needs to be known in order to make more quantitative analysis. Such knowledge is currently not available although a reflecting surface model is proposed. We also studied the mutual-diffusion of compatible linear chains. It is observed that the broadening of the interfacial width scales as the 1/4 power of the diffusion time for a time scale much longer than the reptation time. It is speculated that the anomalous behavior is either due to small molecular residue in the sample or due to the long chain nature of the polymer itself. If the former possibility can be ruled out, the validity of applying the reptation model to polymer diffusion over small distances might be under challenge. Dynamic secondary ion mass spectrometry (SIMS) is an established technique and its application in polymer science has been around for quite some time. However, the quantitative application in depth profiling was so far not very successful. The technique is reviewed and procedures that ensure correct extraction of depth profiles from raw SIMS data are discussed.

  1. Susceptibility of synthetic long-chain alkylbenzenes to degradation in reducing marine sediments

    USGS Publications Warehouse

    Eganhouse, Robert P.; Pontolillo, James

    2008-01-01

    Long-chain alkylbenzenes (LCABs) synthesized for production of alkylbenzene sulfonate surfactants have been used as molecular markers of anthropogenic waste for 25 years. Synthetic LCABs comprise two classes, the tetrapropylene-based alkylbenzenes (TABs) and the linear alkylbenzenes (LABs). LABs supplanted TABs in the mid-1960s because of improved biodegradability of their sulfonated analogs. Use of LCABs for molecular stratigraphy depends on their preservation in sediments over decadal time scales. Most laboratory and field studies suggest that LABs degrade rapidly under aerobic conditions but are resistant to degradation when oxygen is absent. However, recent work indicates that LABs may not be as persistent under reducing conditions as previously thought. To assess the potential for degradation of LCABs in reducing sediments, box cores collected in 1992 and 2003 near a submarine wastewater outfall system were analyzed using gas chromatography/mass spectrometry. The TABs were effectively preserved; differences between whole-core inventories were within analytical error. By contrast, whole-core inventories of the LABs decreased by about 50-60% during the same time interval. Based on direct comparison of chemical inventories in coeval core sections, LAB transformation rates are estimated at 0.07 ±. 0.01 yr-1. These results indicate that caution should be exercised when using synthetic LCABs for reconstruction of depositional records.

  2. Role of Long-Chain Omega-3 Fatty Acids in Psychiatric Practice.

    PubMed

    McNamara, Robert K; Strawn, Jeffrey R

    2013-04-01

    Nutrition plays a minor role in psychiatric practice which is currently dominated by a pharmacological treatment algorithm. An accumulating body of evidence has implicated deficits in the dietary essential long-chain omega-3 (LCn-3) fatty acids, eicosapenaenoic acid (EPA) and docosahexaenoic acid (DHA), in the pathophysiology of several major psychiatric disorders. LCn-3 fatty acids have an established long-term safety record in the general population, and existing evidence suggests that increasing LCn-3 fatty acid status may reduce the risk for cardiovascular disease morbidity and mortality. LCn-3 fatty acid supplementation has been shown to augment the therapeutic efficacy of antidepressant, mood-stabilizer, and second generation antipsychotic medications, and may additionally mitigate adverse cardiometabolic side-effects. Preliminary evidence also suggests that LCn-3 fatty acid supplementation may be efficacious as monotherapy for primary and early secondary prevention and for perinatal symptoms. The overall cost-benefit ratio endorses the incorporation of LCn-3 fatty acids into psychiatric treatment algorithms. The recent availability of laboratory facilities that specialize in determining blood LCn-3 fatty acid status and emerging evidence-based consensus guidelines regarding safe and efficacious LCn-3 fatty acid dose ranges provide the infrastructure necessary for implementation. This article outlines the rationale for incorporating LCn-3 fatty acid treatment into psychiatric practice. PMID:23607087

  3. Enzymatic characterization of ELOVL1, a key enzyme in very long-chain fatty acid synthesis.

    PubMed

    Schackmann, Martin J A; Ofman, Rob; Dijkstra, Inge M E; Wanders, Ronald J A; Kemp, Stephan

    2015-02-01

    X-linked adrenoleukodystrophy (X-ALD) is a neurometabolic disease that is caused by mutations in the ABCD1 gene. ABCD1 protein deficiency impairs peroxisomal very long-chain fatty acid (VLCFA) degradation resulting in increased cytosolic VLCFA-CoA levels, which are further elongated by the VLCFA-specific elongase, ELOVL1. In adulthood, X-ALD most commonly manifests as a gradually progressive myelopathy (adrenomyeloneuropathy; AMN) without any curative or disease modifying treatments. We recently showed that bezafibrate reduces VLCFA accumulation in X-ALD fibroblasts by inhibiting ELOVL1. Although, in a clinical trial, bezafibrate was unable to lower VLCFA levels in plasma or lymphocytes in X-ALD patients, inhibition of ELOVL1 remains an attractive therapeutic option. In this study, we investigated the kinetic characteristics of ELOVL1 using X-ALD fibroblasts and microsomal fractions from ELOVL1 over-expressing HEK293 cell lines and analyzed the inhibition kinetics of a series of fibrates. Our data show that the CoA esters of bezafibrate and gemfibrozil reduce chain elongation by specifically inhibiting ELOVL1. These fibrates can therefore serve as lead compounds for the development of more potent and more specific inhibitors for ELOVL1. PMID:25499606

  4. Suppression of adipose lipolysis by long-chain fatty acid analogs.

    PubMed

    Kalderon, Bella; Azazmeh, Narmen; Azulay, Nili; Vissler, Noam; Valitsky, Michael; Bar-Tana, Jacob

    2012-05-01

    Agonist-induced lipolysis of adipose fat is robustly inhibited by insulin or by feedback inhibition by the long-chain fatty acids (LCFA) produced during lipolysis. However, the mode of action of LCFA in suppressing adipose lipolysis is not clear. β,β'-Tetramethyl hexadecanedioic acid (Mββ/ EDICA16) is a synthetic LCFA that is neither esterified into lipids nor β-oxidized, and therefore, it was exploited for suppressing agonist-induced lipolysis in analogy to natural LCFA. Mββ is shown here to suppress isoproterenol-induced lipolysis in the rat in vivo as well as in 3T3-L1 adipocytes. Inhibition of isoproterenol-induced lipolysis is due to decrease in isoproterenol-induced cAMP with concomitant inhibition of the phosphorylation of hormone-sensitive lipase and perilipin by protein kinase A. Suppression of cellular cAMP levels is accounted for by inhibition of the adenylate cyclase due to suppression of Raf1 expression by Mββ-activated AMPK. Suppression of Raf1 is further complemented by induction of components of the unfolded-protein-response by Mββ. Our findings imply genuine inhibition of agonist-induced adipose lipolysis by LCFA, independent of their β-oxidation or reesterification. Mββ suppression of agonist-induced lipolysis and cellular cAMP levels independent of the insulin transduction pathway may indicate that synthetic LCFA could serve as insulin mimetics in the lipolysis context under conditions of insulin resistance. PMID:22338010

  5. Long chain lipid based tamoxifen NLC. Part I: preformulation studies, formulation development and physicochemical characterization.

    PubMed

    Shete, Harshad; Patravale, Vandana

    2013-09-15

    Tamoxifen citrate (Tmx) was formulated in nanostructured lipid carrier system (NLC) using long chain solid lipids (LCSL) and oils (LCO) with the aim to target lymphatic system to improve its bioavailability in plasma and lymphnode (initial sites for metastasis) and reduce its drug associated toxicity. Tamoxifen loaded NLC (Tmx-NLC) was formulated using solvent diffusion technique. Preformulation studies comprised evaluation of drug-excipients compatibility. Solubility of Tmx was screened in LCSL and LCO, surfactants and co-surfactants to identify NLC components. Surfactant co-surfactant combinations were studied for their ability to stabilize the system. Tmx-NLC was physicochemically characterized by TEM, DSC, XRD, and FTIR studies. Drug-excipients chemical compatibility study facilitated anticipation of excipients induced oxidative degradation of Tmx. Suitable storage condition below 30°C could stabilize Tmx. Tmx-NLC with >90% entrapment efficiency and 215.60 ± 7.98 nm particle size were prepared and freeze dried. Freeze dried Tmx-NLC could withstand various gastrointestinal tract (GI) media (pH 1.2, pH 3.5, pH 4.5, pH 6.8, pH 7.4). Dissolution profile of Tmx-NLC in various media showed sustained release pattern irrespective of pH of medium. No significant change in characteristics of Tmx-NLC was observed after 3 months of accelerated stability studies. PMID:23535345

  6. Subcell-matched epitaxy of normal long chain compounds on polyethylene. I. on the (110) plane

    NASA Astrophysics Data System (ADS)

    Okihara, Takumi; Kawaguchi, Akiyoshi; Ohara, Masayoshi; Katayama, Ken-ichi

    1990-11-01

    Polyethylene films with surfaces bounded by {110} planes were prepared. On the film surfaces, various normal long chain compounds, such as normal paraffins (n-C nG 2 n+2 ) with n of 23 through 50, alcohols (n-C nH 2 n+1 OH) and carboxylic aci ds ( -C n-1 H 2 n-1 COOH) were epitaxially crystallized from solution, melt, and vapor phase. The molecular chains are lying down parallel to the chain axis of polyethylene when crystallized at low temperatures, exhibiting different crystalline modifications. Irrespective of the nature of the compound, the epitaxial relationships were explained in terms of a common lattice coincidence between orthorhombic subcells of the compounds and the unit cell of polyethylene: (110) sc∥(110) PE, [001] sc∥[001] PE, where sc a nd PE denote the subcells of the compounds and the polyethylene, respectively. By contrast, when crystallized at high temperatures from the vapor phase and the melt, the molecules stood normal on or tilted to the substrate, keeping the relations of (001) basal plane of the unit cell of the compounds parallel to (110) PE and the [110] direction parallel to the [001] direction of polyethylene.

  7. Extracorporeal membrane oxygenation promotes long chain fatty acid oxidation in the immature swine heart in vivo

    SciTech Connect

    Kajimoto, Masaki; O'Kelly-Priddy, Colleen M.; Ledee, Dolena R.; Xu, Chun; Isern, Nancy G.; Olson, Aaron; Portman, Michael A.

    2013-09-01

    Extracorporeal membrane oxygenation (ECMO) supports infants and children with severe cardiopulmonary compromise. Nutritional support for these children includes provision of medium- and long-chain fatty acids (FAs). However, ECMO induces a stress response, which could limit the capacity for FA oxidation. Metabolic impairment could induce new or exacerbate existing myocardial dysfunction. Using a clinically relevant piglet model, we tested the hypothesis that ECMO maintains the myocardial capacity for FA oxidation and preserves myocardial energy state. Provision of 13-Carbon labeled medium-chain FA (octanoate), longchain free FAs (LCFAs), and lactate into systemic circulation showed that ECMO promoted relative increases in myocardial LCFA oxidation while inhibiting lactate oxidation. Loading of these labeled substrates at high dose into the left coronary artery demonstrated metabolic flexibility as the heart preferentially oxidized octanoate. ECMO preserved this octanoate metabolic response, but also promoted LCFA oxidation and inhibited lactate utilization. Rapid upregulation of pyruvate dehydrogenase kinase-4 (PDK4) protein appeared to participate in this metabolic shift during ECMO. ECMO also increased relative flux from lactate to alanine further supporting the role for pyruvate dehydrogenase inhibition by PDK4. High dose substrate loading during ECMO also elevated the myocardial energy state indexed by phosphocreatine to ATP ratio. ECMO promotes LCFA oxidation in immature hearts, while maintaining myocardial energy state. These data support the appropriateness of FA provision during ECMO support for the immature heart.

  8. Enhancing enzymatic hydrolysis of xylan by adding sodium lignosulfonate and long-chain fatty alcohols.

    PubMed

    Lou, Hongming; Yuan, Long; Qiu, Xueqing; Qiu, Kexian; Fu, Jinguo; Pang, Yuxia; Huang, Jinhao

    2016-01-01

    Sodium lignosulfonate (SXSL) and long-chain fatty alcohols (LFAs) could enhance the enzymatic hydrolysis of xylan, and the compound of SXSL and LFAs have synergies on the enzymatic hydrolysis. SXSL shows a strong enhancement in buffer pH range from 4.0 to 6.0. The enhancement increased with the SXSL dosage and the xylanase loading. The cellulose and lignin in corncob substrate could not only adsorb xylanase nonproductively, but also seriously reduce the accessibility of xylanase on xylan to impede the enzymatic hydrolysis of xylan. Cellulase could break the plant cell wall structure of corncob and make additives work better. The xylose yield of corncob at 72h increased from 59.4% to 73.7% by adding the compound of 5g/L SXSL and 0.01% (v/v) n-decanol, which was higher than that without cellulase and additives by 30.7%. Meanwhile, the glucose yield at 72h of corncob increased from 45.8% to 62.3%. PMID:26476164

  9. Effects of Long Chain Fatty Acid Synthesis and Associated Gene Expression in Microalga Tetraselmis sp

    PubMed Central

    Adarme-Vega, T. Catalina; Thomas-Hall, Skye R.; Lim, David K. Y.; Schenk, Peer M.

    2014-01-01

    With the depletion of global fish stocks, caused by high demand and effective fishing techniques, alternative sources for long chain omega-3 fatty acids are required for human nutrition and aquaculture feeds. Recent research has focused on land-based cultivation of microalgae, the primary producers of omega-3 fatty acids in the marine food web. The effect of salinity on fatty acids and related gene expression was studied in the model marine microalga, Tetraselmis sp. M8. Correlations were found for specific fatty acid biosynthesis and gene expression according to salinity and the growth phase. Low salinity was found to increase the conversion of C18:4 stearidonic acid (SDA) to C20:4 eicosatetraenoic acid (ETA), correlating with increased transcript abundance of the Δ-6-elongase-encoding gene in salinities of 5 and 10 ppt compared to higher salinity levels. The expression of the gene encoding β-ketoacyl-coenzyme was also found to increase at lower salinities during the nutrient deprivation phase (Day 4), but decreased with further nutrient stress. Nutrient deprivation also triggered fatty acids synthesis at all salinities, and C20:5 eicosapentaenoic acid (EPA) increased relative to total fatty acids, with nutrient starvation achieving a maximum of 7% EPA at Day 6 at a salinity of 40 ppt. PMID:24901700

  10. Opportunities to enhance alternative sources of long-chain n-3 fatty acids within the diet.

    PubMed

    Delarue, Jacques; Guriec, Nathalie

    2014-08-01

    Health benefits or advocated health benefits of long-chain (LC) n-3 PUFA are better known by medical doctors as well as by consumers, so that consumption increases. In addition, the development of aquaculture requires more fishmeal and fish oil. Humanisation of care of companion animals is also associated with addition of LC n-3 PUFA in pet foods. The risk of the increased demand for LC n-3 PUFA is the excess harvesting of natural sources, especially of marine origin (oily fishes, krill). In order to improve sustainability, alternative sources of LC n-3 PUFA have been developed. These alternative sources are: (a) terrestrial plants naturally or genetically enriched in stearidonic acid (SDA), which bypasses the first limiting step of (i.e. ∆6 desaturase) of the biosynthesis of LC n-3 PUFA; (b) single-cell oils rich in LC n-3 PUFA (microalgae, Escherichia coli) and krill. Currently, plants rich in SDA are expensive, metabolic engineering is unfavourably accepted by consumers in many countries, cultivation of microalgae is very expensive even though their ability (for some of them) to synthesise biofuels could induce a decrease in industrial costs, and Antarctic krill harvest must be restricted. Thus, it is difficult to predict their real development in the future. PMID:24886839

  11. Long-chain omega-3 from low-trophic-level fish provides value to farmed seafood

    PubMed Central

    Bibus, Douglas M

    2015-01-01

    Low-trophic-level fish are a crucial source of long-chain (LC) omega-3 fatty acids for farmed fish and humans. Many farm-raised fish species have a clear need for these nutrients. Farmed fish deposit the LC omega-3s in their flesh and transfer them up the food chain. However, the content of LC omega-3s in farm-raised seafood continues to decline, while the content of shorter-chain plant-sourced omega-3s, and pro-inflammtory omega-6s continue to increase. This reduces its nutritional worth. The value of low-trophic-level fish is often viewed merely as its price at the dock. Some reports and metrics steer public attention towards the mass balance between quantities of low-trophic-level fish and farmed seafood. However, the the nutritional value of seafood is more important than its mere quantities. The role of low-trophic-level fish in human nutrition, health, and wellbeing is a fundamental component of its economic value to society. PMID:26097289

  12. Antibacterial effects of long-chain polyphosphates on selected spoilage and pathogenic bacteria.

    PubMed

    Obritsch, Jeremy A; Ryu, Dojin; Lampila, Lucina E; Bullerman, Lloyd B

    2008-07-01

    The antimicrobial activities of four long-chain food-grade polyphosphates were studied at concentrations allowed in the food industry (<5,000 ppm) in defined basal media by determining the inhibition of growth of three gram-negative and four gram-positive spoilage and pathogenic bacteria. Both generation time and lag phase of Escherichia coli K-12, E. coli O157: H7, and Salmonella Typhimurium were increased with all of the polyphosphates tested. Bacillus subtilis and Staphylococcus aureus were more sensitive to polyphosphates, but not in all cases, with multiphased growth. The growth of Lactobacillus plantarum was inhibited by polyphosphates at concentrations above 750 ppm, but the lag time of Listeria monocytogenes was shortened by the presence of polyphosphates. No single polyphosphate was maximally inhibitory against all bacteria. Polyphosphates with chain lengths of 12 to 15 were significantly different from those with chain lengths of 18 to 21 depending on the organism and concentrations of polyphosphate used. Overall, higher polyphosphate concentrations resulted in greater inhibition of bacterial growth. PMID:18680939

  13. Partitioning of long-chain alcohols into lipid bilayers: implications for mechanisms of general anesthesia.

    PubMed Central

    Franks, N P; Lieb, W R

    1986-01-01

    Alcohols act as anesthetics only up to a certain chain length, beyond which their biological activity disappears. Although the molecular nature of general anesthetic target sites remains unknown, presently available data support the hypothesis that this "cutoff" in anesthetic activity could be due to a corresponding cutoff in the absorption of long-chain alcohols into lipid-bilayer portions of nerve membranes. To test this hypothesis, we have developed an extremely sensitive biological assay, based on inhibition of the light-emitting firefly luciferase reaction, which is capable of measuring lipid-bilayer/buffer partition coefficients K for very lipid soluble compounds. Contrary to the hypothesis and reported data, we find a strictly linear increase in log(K) as the chain length increases [delta(delta G0)CH2 = - 3.63 kJ/mol] for the primary alcohols from decanol to pentadecanol, with no hint of a cutoff. The fact that alcohols continue to partition into lipid bilayers long after their biological activity has ceased is consistent with the view that the primary target sites in general anesthesia are proteins rather than the lipid-bilayer portions of nerve membranes. PMID:3460084

  14. Self-Assembly of Bilayer Vesicles Made of Saturated Long Chain Fatty Acids.

    PubMed

    Douliez, Jean-Paul; Houssou, Bérénice Houinsou; Fameau, A-Laure; Navailles, Laurence; Nallet, Frédéric; Grélard, Axelle; Dufourc, Erick J; Gaillard, Cédric

    2016-01-19

    Saturated long chain fatty acids (sLCFA, e.g., C14:0, C16:0, and C18:0) are potentially the greenest and cheapest surfactants naturally available. However, because aqueous sodium soaps of sLCFA are known to crystallize, the self-assembly of stable bilayer vesicles has not been reported yet. Here, by using such soaps in combination with guanidine hydrochloride (GuHCl), which has been shown recently to prevent crystallization, we were capable of producing stable bilayer vesicles made of sLCFA. The phase diagrams were established for a variety of systems showing that vesicles can form in a broad range of composition and pH. Both solid state NMR and small-angle neutron scattering allowed demonstrating that in such vesicles sLCFA are arranged in a bilayer structure which exhibits similar dynamic and structural properties as those of phospholipid membranes. We expect these vesicles to be of interest as model systems of protocells and minimal cells but also for various applications since fatty acids are potentially substitutes to phospholipids, synthetic surfactants, and polymers. PMID:26700689

  15. Long-chain carboxylic acids in pyrolysates of Green River kerogen

    NASA Technical Reports Server (NTRS)

    Kawamura, K.; Tannenbaum, E.; Huizinga, B. J.; Kaplan, I. R.

    1986-01-01

    Long-chain fatty acids (C10-C32), as well as C14-C21 isoprenoid acids (except for C18), have been identified in anhydrous and hydrous pyrolyses products of Green River kerogen (200-400 degrees C, 2-1000 hr). These kerogen-released fatty acids are characterized by a strong even/odd predominance (CPI: 4.8-10.2) with a maximum at C16 followed by lesser amounts of C18 and C22 acids. This distribution is different from that of unbound and bound geolipids extracted from Green River shale. The unbound fatty acids show a weak even/odd predominance (CPI: 1.64) with a maximum at C14, and bound fatty acids display an even/odd predominance (CPI: 2.8) with maxima at C18 and C30. These results suggest that fatty acids were incorporated into kerogen during sedimentation and early diagenesis and were protected from microbial and chemical changes over geological periods of time. Total quantities of fatty acids produced during heating of the kerogen ranged from 0.71 to 3.2 mg/g kerogen. Highest concentrations were obtained when kerogen was heated with water for 100 hr at 300 degrees C. Generally, their amounts did not decrease under hydrous conditions with increase in temperature or heating time, suggesting that significant decarboxylation did not occur under the pyrolysis conditions used, although hydrocarbons were extensively generated.

  16. Long-chain polyunsaturated fatty acid status in obesity: a systematic review and meta-analysis.

    PubMed

    Fekete, K; Györei, E; Lohner, S; Verduci, E; Agostoni, C; Decsi, T

    2015-06-01

    Long-chain polyunsaturated fatty acid (LCPUFA) status has recently been related to the pathogenesis of obesity. Our aims were to systematically review observational studies investigating LCPUFA status from different blood compartments in overweight or obese subjects and to assess the relationship between LCPUFA profile and obesity. The Ovid MEDLINE, Scopus and Cochrane Library CENTRAL databases were searched from inception to January 2014. The meta-analysis showed significant differences in the LCPUFA composition of total plasma lipids, plasma phospholipids and plasma cholesteryl esters between overweight or obese subjects and controls. Dihomo-γ-linolenic acid (DGLA) values were significantly higher in overweight or obese subjects compared with controls in all the investigated biomarkers. In addition, the DGLA/linoleic acid ratio (surrogate parameter for Δ6 desaturase activity) in plasma phospholipids was significantly elevated (mean difference [MD]: 0.05; 95% confidence interval [CI]: 0.02, 0.08; n = 280), while the arachidonic acid/DGLA ratio (surrogate parameter for Δ5 desaturase activity) was significantly decreased (MD: -0.55; 95% CI: -0.71, -0.39; n = 347) in overweight or obese subjects compared with controls. The results of the present meta-analysis confirm that LCPUFA profile is altered in obesity and suggest that the differences observed in desaturase activities may be responsible for the disturbed LCPUFA metabolism in obesity. PMID:25828602

  17. Genetically engineering cyanobacteria to convert CO₂, water, and light into the long-chain hydrocarbon farnesene.

    PubMed

    Halfmann, Charles; Gu, Liping; Gibbons, William; Zhou, Ruanbao

    2014-12-01

    Genetically engineered cyanobacteria offer a shortcut to convert CO2 and H2O directly into biofuels and high value chemicals for societal benefits. Farnesene, a long-chained hydrocarbon (C15H24), has many applications in lubricants, cosmetics, fragrances, and biofuels. However, a method for the sustainable, photosynthetic production of farnesene has been lacking. Here, we report the photosynthetic production of farnesene by the filamentous cyanobacterium Anabaena sp. PCC 7120 using only CO2, mineralized water, and light. A codon-optimized farnesene synthase gene was chemically synthesized and then expressed in the cyanobacterium, enabling it to synthesize farnesene through its endogenous non-mevalonate (MEP) pathway. Farnesene excreted from the engineered cyanobacterium volatilized into the flask head space and was recovered by adsorption in a resin column. The maximum photosynthetic productivity of farnesene was 69.1 ± 1.8 μg·L(-1)·O.D.(-1)·d(-1). Compared to the wild type, the farnesene-producing cyanobacterium also exhibited a 60 % higher PSII activity under high light, suggesting increased farnesene productivity in such conditions. We envision genetically engineered cyanobacteria as a bio-solar factory for photosynthetic production of a wide range of biofuels and commodity chemicals. PMID:25301585

  18. Fat Metabolism in Higher Plants XXXVI: Long Chain Fatty Acid Synthesis in Germinating Peas 1

    PubMed Central

    Macey, Michael J. K.; Stumpf, P. K.

    1968-01-01

    A low lipid, high starch containing tissue, namely cotyledons of germinating pea seedlings was examined for its capacity to synthesize fatty acid. Intact tissue slices readily incorporate acetate-14C into fatty acids from C16 to C24. Although crude homogenates synthesize primarily 16:0 and 18:0 from malonyl CoA, subsequent fractionation into a 10,000g pellet, a 105g pellet and supernatant (soluble synthetase) revealed that the 105g pellet readily synthesizes C16 to C28 fatty acids whereas the 10,000g and the supernatant synthesize primarily C16 and C18. All systems require acyl carrier protein (ACP), TPNH, DPNH if malonyl CoA is the substrate and ACP, Mg2+, CO2, ATP, TPNH, and DPNH if acetyl CoA is the substrate. The cotyledons of germinating pea seedlings appear to have a soluble synthetase and 10,000g particles for the synthesis of C16 and C18 fatty acid, and 105g particles which specifically synthesize the very long chain fatty acid from malonyl CoA, presumably via malonyl ACP. PMID:16656949

  19. Gating of the mitochondrial permeability transition pore by long chain fatty acyl analogs in vivo.

    PubMed

    Samovski, Dmitri; Kalderon, Bella; Yehuda-Shnaidman, Einav; Bar-Tana, Jacob

    2010-03-01

    The role played by long chain fatty acids (LCFA) in promoting energy expenditure is confounded by their dual function as substrates for oxidation and as putative classic uncouplers of mitochondrial oxidative phosphorylation. LCFA analogs of the MEDICA (MEthyl-substituted DICarboxylic Acids) series are neither esterified into lipids nor beta-oxidized and may thus simulate the uncoupling activity of natural LCFA in vivo, independently of their substrate role. Treatment of rats or cell lines with MEDICA analogs results in low conductance gating of the mitochondrial permeability transition pore (PTP), with 10-40% decrease in the inner mitochondrial membrane potential. PTP gating by MEDICA analogs is accounted for by inhibition of Raf1 expression and kinase activity, resulting in suppression of the MAPK/RSK1 and the adenylate cyclase/PKA transduction pathways. Suppression of RSK1 and PKA results in a decrease in phosphorylation of their respective downstream targets, Bad(Ser-112) and Bad(Ser-155). Decrease in Bad(Ser-112, Ser-155) phosphorylation results in increased binding of Bad to mitochondrial Bcl2 with concomitant displacement of Bax, followed by PTP gating induced by free mitochondrial Bax. Low conductance PTP gating by LCFA/MEDICA may account for their thyromimetic calorigenic activity in vivo. PMID:20037159

  20. Wetting and spreading of long-chain ZDOL polymer nanodroplet on graphene-coated amorphous carbon

    NASA Astrophysics Data System (ADS)

    Sorkin, V.; Zhang, Y. W.

    2014-12-01

    Wetting transparency/translucency/opacity of graphene recently has attracted great interest. The underlying mechanisms and physics for simple liquid droplets containing small molecules on graphene coated crystalline substrates have been studied extensively. However, the behavior of more complicated polymeric droplets on graphene coated amorphous substrates has not been explored. In this work, we perform molecular dynamics simulations to examine the wetting of long-chain ZDOL polymeric droplet on graphene coated amorphous hydrogenated diamond-like carbon or DLCH. We find that at room temperature, the droplet adopts a nearly spherical cap shape with no protruding foot on bare DLCH, and a complex multi-layered structure is formed at the droplet-substrate interface. With addition of graphene layers, externally, the height of the droplet decreases and the protruding foot at the droplet edge appears and grows in size; while internally, the complex multi-layered structure near the droplet-substrate interface remains, but the density distribution for the formed layers becomes increasingly non-uniform. A steady state of the droplet is attained when the number of graphene layers reaches three. These changes can be explained by the interactions between the droplet and substrate across the number of graphene layers. Therefore, it is concluded that the graphene monolayer and bilayer are translucent, while trilayer and above are opaque from the wetting point of view.

  1. Long chain n-3 polyunsaturated fatty acids decrease feelings of anger in substance abusers

    PubMed Central

    Buydens-Branchey, Laure; Branchey, Marc

    2008-01-01

    It has been suggested that low levels of n-3 polyunsaturated fatty acids (PUFAs) play a role in the pathophysiology of some psychiatric disorders. In light of the existence of strong associations between high-frequency and high-severity aggressive behaviors and substance use disorders and of our observation that substance abusers have poor dietary habits, the possibility that the administration of supplements of n-3 PUFAs would decrease their anger levels was explored. A life long history of aggressive behaviors and problems with the law was obtained in 24 patients. Thirteen patients received on a daily basis capsules containing 3 g of n-3 PUFAs (EPA+DHA). Eleven patients received placebo capsules. The trial was double-blind, randomized, and lasted 3 months. An anger scale was administered at baseline and every month thereafter. Six PUFA group patients and eight placebo group patients were followed for an additional 3 months after treatment discontinuation. Four patients in each group had a history of assaultive behavior. The baseline fish and n-3 PUFA intakes of these 8 patients were significantly lower than those of the non-aggressive patients. When given for 3 months, n-3 PUFAs were superior to placebo in diminishing anger scores. These scores remained decreased for 3 months following treatment discontinuation. These data provide further support to emerging evidence indicating that supplementation with long-chain n-3 PUFAs could be beneficial in the treatment of some individuals with aggressive tendencies. PMID:17900705

  2. Alternative Sources of n-3 Long-Chain Polyunsaturated Fatty Acids in Marine Microalgae

    PubMed Central

    Martins, Dulce Alves; Custódio, Luísa; Barreira, Luísa; Pereira, Hugo; Ben-Hamadou, Radhouan; Varela, João; Abu-Salah, Khalid M.

    2013-01-01

    The main source of n-3 long-chain polyunsaturated fatty acids (LC-PUFA) in human nutrition is currently seafood, especially oily fish. Nonetheless, due to cultural or individual preferences, convenience, geographic location, or awareness of risks associated to fatty fish consumption, the intake of fatty fish is far from supplying the recommended dietary levels. The end result observed in most western countries is not only a low supply of n-3 LC-PUFA, but also an unbalance towards the intake of n-6 fatty acids, resulting mostly from the consumption of vegetable oils. Awareness of the benefits of LC-PUFA in human health has led to the use of fish oils as food supplements. However, there is a need to explore alternatives sources of LC-PUFA, especially those of microbial origin. Microalgae species with potential to accumulate lipids in high amounts and to present elevated levels of n-3 LC-PUFA are known in marine phytoplankton. This review focuses on sources of n-3 LC-PUFA, namely eicosapentaenoic and docosahexaenoic acids, in marine microalgae, as alternatives to fish oils. Based on current literature, examples of marketed products and potentially new species for commercial exploitation are presented. PMID:23807546

  3. Long-chain Omega-3 Fatty Acids and Optimization of Cognitive Performance

    PubMed Central

    Muldoon, Matthew F.; Ryan, Christopher M.; Yao, Jeffrey K.; Conklin, Sarah M.; Manuck, Stephen B.

    2016-01-01

    Low consumption of the omega-3 fatty acids, eicosapentaenoic (EPA) and docosahexaenonic acids (DHA), is linked to delayed brain development and, in late life, increased risk for Alzheimers Disease. The current review focuses on cognitive functioning during mid-life and summarizes available scientific evidence relevant to the hypothesis that adequate dietary consumption of the long-chain, omega-3 fatty acids is necessary for optimal cognitive performance. Taken together, the findings suggest that raising the currently low consumption among healthy adults may improve some aspects of cognitive performance. Nonetheless, evidence from randomized clinical trials is comparatively sparse and leaves unclear: a) whether such effects are clinically significant, b) whether effects of EPA and DHA differ, c) which dimensions of cognitive function are affected, d) the dose-response relationships, or e) the time course of the response. Clarification of these issues through both laboratory and clinical investigations is a priority given the broad implications for public health, as well as for military personnel and other positions of high performance demand and responsibility. PMID:25373092

  4. Rotational isomerism and physical properties of long-chain molecules in solid states

    NASA Astrophysics Data System (ADS)

    Kobayashi, M.

    1985-01-01

    Rotational isomerism occurring in solid state of organic long-chain compounds, including synthetic linear polymers, have been concerned in connection with the macroscopic physical properties of bulk materials. The conformational order in the non-crystalline part of polyethylene has been investigated by Raman spectra, and related to the elastic behaviors of bulk samples. In the solid-state phase transition induced by mechanical forces of poly(butylene terephthalate) the macroscopic strain has been related directly to the conformational conversion of the molecules. Concerning the piezoelectric and pyroelectric activities of poly(vinylidene fluoride), polymorphism, phase transition, and structural change on the poling process have been investigated. A ferroelectric-paraelectric phase transition has been found for a series of copolymers of vinylidene fluoride and trifluoroethylene. On the phase transition a great change in molecular conformation is accompanied with the scrambling of the dipolar orientation. This is the characteristic of polymer ferroelectrics in which the dipolar units are linked with each other by covalent bonds in a molecular chain. Spectroscopic evidences are presented indicating that the thermodynamic stability of polymorphs of n-fatty acids is closely related to the rotational isomerism occurring in the carboxyl groups.

  5. A 5-month open study with long-chain polyunsaturated fatty acids in dyslexia.

    PubMed

    Lindmark, Lars; Clough, Peter

    2007-12-01

    This open pilot study investigated effects of a docosahexaenoic acid (DHA)-rich supplement on learning ability in a group of 20 dyslexic children in Sweden. Children formally diagnosed as dyslexic took eight capsules per day of a long-chain polyunsaturated fatty acid (LC-PUFA) supplement containing high-DHA fish oil and evening primrose oil. Subjective assessments by the children and their parents were completed at baseline and 6, 12, and 20 weeks after supplementation. Quantitative evaluation by word-chain test was completed before and after 4 months of supplementation to measure word decoding (speed of reading) and letter decoding (motoric-perceptual speed). Subjective parent and child assessments showed increasing numbers of positive responders over time in reading speed, general schoolwork, and overall perceived benefit. Significant improvements were observed in reading speed and motor-perceptual velocity. Thirteen of 17 children had a significant improvement on the word-chain test (P < .04). Reading speed improved by 60% from 1.76 +/- 0.29 before the study to 2.82 +/- 0.36 after supplementation (P < .01 by Wilcoxon sign test). Motoric-perceptual velocity improved by 23% from a stanine value of 3.76 +/- 0.42 to 4.65 +/- 0.66 after supplementation (P < .05 by Wilcoxon sign test). Thus LC-PUFA supplementation for 5 months provides positive and clear beneficial effect on variables usually impaired by dyslexia. PMID:18158838

  6. Quantitative Profiling of Long-Chain Bases by Mass Tagging and Parallel Reaction Monitoring

    PubMed Central

    Ejsing, Christer S.; Bilgin, Mesut; Fabregat, Andreu

    2015-01-01

    Long-chain bases (LCBs) are both intermediates in sphingolipid metabolism and potent signaling molecules that control cellular processes. To understand how regulation of sphingolipid metabolism and levels of individual LCB species impinge upon physiological and pathophysiological processes requires sensitive and specific assays for monitoring these molecules. Here we describe a shotgun lipidomics method for quantitative profiling of LCB molecules. The method employs a “mass-tag” strategy where LCBs are chemically derivatized with deuterated methyliodide (CD3I) to produce trimethylated derivatives having a positively charged quaternary amine group. This chemical derivatization minimizes unwanted in-source fragmentation of LCB analytes and prompts a characteristic trimethylaminium fragment ion that enables sensitive and quantitative profiling of LCB molecules by parallel reaction monitoring on a hybrid quadrupole time-of-flight mass spectrometer. Notably, the strategy provides, for the first time, a routine for monitoring endogenous 3-ketosphinganine molecules and distinguishing them from more abundant isomeric sphingosine molecules. To demonstrate the efficacy of the methodology we report an in-depth characterization of the LCB composition of yeast mutants with defective sphingolipid metabolism and the absolute levels of LCBs in mammalian cells. The strategy is generic, applicable to other types of mass spectrometers and can readily be applied as an additional routine in workflows for global lipidome quantification and for functional studies of sphingolipid metabolism. PMID:26660097

  7. Flow-induced Crystallization of Long Chain Aliphatic Polyamides under a Complex Flow Field

    NASA Astrophysics Data System (ADS)

    Dong, Xia; Gao, Yunyun; Wang, Lili; Wang, Dujin

    The present work deals with the flow-induced multiple orientations and crystallization structure of polymer melts under a complex flow field. This complex flow field is characteristic of the consistent coupling of extensional ``pulse'' and closely followed shear flow in a narrow channel. Utilizing an ingenious combination of an advanced micro-injection device and long chain aliphatic polyamides, the flow-induced crystallization morphology was well preserved for ex-situ synchrotron micro-focused wide angle X-ray scattering as well as small angle X-ray scattering. The experimental results clearly indicate that the effect of extensional pulse on the polymer melt is restrained and further diminished due to either the transverse tumble of fountain flow or the rapid retraction of stretched high molecular weight tails. However, the residual shish-kebab structures in the core layer of the far-end of channel suggest that the effect of extensional pulse should be considered in the small-scaled geometries or under the high strain rate condition. The authors thank the financial support from MOST (2013BAE02B02, 2014CB643600) and NSFC(21574140).

  8. pH-Tunable wormlike micelles based on an ultra-long-chain "pseudo" gemini surfactant.

    PubMed

    Feng, Yujun; Chu, Zonglin

    2015-06-21

    Smart surfactant wormlike micelles (SWLMs), responsive to external stimuli, are a particularly recent area of development, yet highly promising, given the versatility of the materials but simplicity of the design. Here, we developed a pH-switchable wormlike micellar system based on a "pseudo" gemini surfactant (named as EAMA) formed by a mixture of N-erucamido-N,N-dimethylamine (UC22AMPM) and maleic acid with a molar ratio of 2 : 1, and compared the "pseudo" gemini worm system with UC22AMPM in the presence of hydrochloric acid (EAHCl). It was found that both maleic acid and hydrochloric acid can protonate the ultra-long-chain tertiary amine into a quaternary ammonium surfactant, thereby forming wormlike micelles; however, much stronger viscoelastic behavior was evidenced in the maleic acid system because one protonated maleic acid molecule can "bridge" two quaternized UC22AMPM molecules via electrostatic attraction. In contrast, the EAHCl system just shows a "mono" quaternary ammonium feature with a weak viscosity buildup. In addition, the maleic acid-based worm system was found to be more thermo-sensitive than conventional wormlike micelles, which also originates due to its "pseudo" gemini architecture. PMID:25959441

  9. Synthesis of Long-Chain Acyl-CoA in Chloroplast Envelope Membranes 1

    PubMed Central

    Joyard, Jacques; Stumpf, Paul K.

    1981-01-01

    The chloroplast envelope is the site of a very active long-chain acylcoenzyme A (CoA) synthetase. Furthermore, we have recently shown that an acyl CoA thioesterase is also associated with envelope membrane (Joyard J, PK Stumpf 1980 Plant Physiol 65: 1039-1043). To clarify the interacting roles of both the acyl-CoA thioesterase and the acyl-CoA synthetase, the formation of acyl-CoA in envelope membranes was examined with different techniques which permitted the measurement of the actual rates of acyl-CoA formation. Using [14C]ATP or [14C]oleic acid as labeled substrates, it can be shown that the envelope acyl-CoA synthetase required both Mg2+ and dithiothreitol. Triton X-100 slightly stimulated the activity. The specificity of the acyl-CoA synthetase was determined either with [14C]ATP or with [3H]CoA as substrates. The results obtained in both cases were similar, that is, as substrates, the unsaturated fatty acids were more effective than saturated fatty acids, the velocity of the reaction increased from lauric acid to palmitic acid, and the maximum velocity was obtained with unsaturated C18 fatty acids. The results obtained suggest that the acyl-CoA thioesterase associated with envelope membranes could be an ultimate control to prevent the transport (outside of the chloroplast) or the insertion (into chloroplast lipids) of fatty acids with chains shorter than C16. PMID:16661656

  10. Mitigation of Inflammation-Induced Mood Dysregulation by Long-Chain Omega-3 Fatty Acids

    PubMed Central

    McNamara, Robert K.

    2015-01-01

    Although evidence suggests that chronic elevations in immune-inflammatory signaling can precipitate mood symptoms in a subset of individuals, associated risk and resilience mechanisms remain poorly understood. Long-chain omega-3 (LCn-3) fatty acids, including eicosapentaenic acid (EPA) and docosahexaenoic acid (DHA), have anti-inflammatory and inflammation-resolving properties which maintain immune-inflammatory signaling homeostasis. Cross-sectional evidence suggests that the mood disorders major depressive disorder and bipolar disorder are associated with low EPA and/or DHA biostatus, elevations in the LCn-6/LCn-3 fatty acid ratio, and elevated levels of pro-inflammatory eicosanoids, cytokines, and acute-phase proteins. Medications that are effective for reducing depressive symptoms or stabilizing manic-depressive oscillations may act in part by down-regulating immune-inflammatory signaling and are augmented by anti-inflammatory medications. Recent prospective longitudinal evidence suggests that elevations in the LCn-6/LCn-3 fatty acid ratio are a modifiable risk factor for the development of mood symptoms, including depression and irritability, in response to immune-inflammatory signaling. Together these data suggest that increasing LCn-3 fatty acid intake and biostatus represents a feasible strategy to mitigate the negative impact of elevated immune-inflammatory signaling on mood stability. PMID:26400435

  11. STATISTICAL EVALUATION OF AN ANALYTICAL GC/MS METHOD FOR THE DETERMINATION OF LONG CHAIN FATTY ACIDS

    EPA Science Inventory

    In-depth evaluation of an analytical method to detect and quantify long chain fatty acids (C8 - C16) at trace level concentrations (25-1000 µg/l) is presented. The method requires derivatization of the acids with methanolic boron trifluoride, separation, and...

  12. Treatment of cardiomyopathy and rhabdomyolysis in long-chain fat oxidation disorders using an anaplerotic odd-chain triglyceride

    PubMed Central

    Roe, Charles R.; Sweetman, Lawrence; Roe, Diane S.; David, France; Brunengraber, Henri

    2002-01-01

    The current dietary treatment of long-chain fatty acid oxidation defects (high carbohydrate with medium-even-chain triglycerides and reduced amounts of long-chain fats) fails, in many cases, to prevent cardiomyopathy, rhabdomyolysis, and muscle weakness. We hypothesized that the apparent defect in energy production results from a depletion of the catalytic intermediates of the citric acid cycle via leakage through cell membranes (cataplerosis). We further hypothesized that replacing dietary medium-even-chain fatty acids (precursors of acetyl-CoA) by medium-odd-chain fatty acids (precursors of acetyl-CoA and anaplerotic propionyl-CoA) would restore energy production and improve cardiac and skeletal muscle function. We fed subjects with long-chain defects a controlled diet in which the fat component was switched from medium-even-chain triglycerides to triheptanoin. In three patients with very-long-chain acyl-CoA dehydrogenase deficiency, this treatment led rapidly to clinical improvement that included the permanent disappearance of chronic cardiomyopathy, rhabdomyolysis, and muscle weakness (for more than 2 years in one child), and of rhabdomyolysis and weakness in the others. There was no evidence of propionyl overload in these patients. The treatment has been well tolerated for up to 26 months and opens new avenues for the management of patients with mitochondrial fat oxidation disorders. PMID:12122118

  13. Long-chain fatty acid combustion rate is associated with unique metabolite profiles in skeletal muscle mitochondria

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Incomplete or limited long-chain fatty acid (LCFA) combustion in skeletal muscle has been associated with insulin resistance. Signals that are responsive to shifts in LCFA beta-oxidation rate or degree of intramitochondrial catabolism are hypothesized to regulate second messenger systems downstream...

  14. Treatment of cardiomyopathy and rhabdomyolysis in long-chain fat oxidation disorders using an anaplerotic odd-chain triglyceride.

    PubMed

    Roe, Charles R; Sweetman, Lawrence; Roe, Diane S; David, France; Brunengraber, Henri

    2002-07-01

    The current dietary treatment of long-chain fatty acid oxidation defects (high carbohydrate with medium-even-chain triglycerides and reduced amounts of long-chain fats) fails, in many cases, to prevent cardiomyopathy, rhabdomyolysis, and muscle weakness. We hypothesized that the apparent defect in energy production results from a depletion of the catalytic intermediates of the citric acid cycle via leakage through cell membranes (cataplerosis). We further hypothesized that replacing dietary medium-even-chain fatty acids (precursors of acetyl-CoA) by medium-odd-chain fatty acids (precursors of acetyl-CoA and anaplerotic propionyl-CoA) would restore energy production and improve cardiac and skeletal muscle function. We fed subjects with long-chain defects a controlled diet in which the fat component was switched from medium-even-chain triglycerides to triheptanoin. In three patients with very-long-chain acyl-CoA dehydrogenase deficiency, this treatment led rapidly to clinical improvement that included the permanent disappearance of chronic cardiomyopathy, rhabdomyolysis, and muscle weakness (for more than 2 years in one child), and of rhabdomyolysis and weakness in the others. There was no evidence of propionyl overload in these patients. The treatment has been well tolerated for up to 26 months and opens new avenues for the management of patients with mitochondrial fat oxidation disorders. PMID:12122118

  15. Dietary long-chain polyunsaturated fatty acids upregulate expression of FADS3 transcripts.

    PubMed

    Reardon, Holly T; Hsieh, Andrea T; Park, Woo Jung; Kothapalli, Kumar S D; Anthony, Joshua C; Nathanielsz, Peter W; Brenna, J Thomas

    2013-01-01

    The fatty acid desaturase (FADS) gene family at 11q12-13.1 includes FADS1 and FADS2, both known to mediate biosynthesis of omega-3 and omega-6 long-chain polyunsaturated fatty acids (LCPUFA). FADS3 is a putative desaturase due to its sequence similarity with FADS1 and FADS2, but its function is unknown. We have previously described 7 FADS3 alternative transcripts (AT) and 1 FADS2 AT conserved across multiple species. This study examined the effect of dietary LCPUFA levels on liver FADS gene expression in vivo and in vitro, evaluated by qRT-PCR. Fourteen baboon neonates were randomized to three diet groups for their first 12 weeks of life, C: Control, no LCPUFA, L: 0.33% docosahexaenoic acid (DHA)/0.67% arachidonic acid (ARA) (w/w); and L3: 1.00% DHA/0.67% ARA (w/w). Liver FADS1 and both FADS2 transcripts were downregulated by at least 50% in the L3 group compared to controls. In contrast, FADS3 AT were upregulated (L3 > C), with four transcripts significantly upregulated by 40% or more. However, there was no evidence for a shift in liver fatty acids to coincide with increased FADS3 expression. Significant upregulation of FADS3 AT was also observed in human liver-derived HepG2 cells after DHA or ARA treatment. The PPARγ antagonist GW9662 prevented FADS3 upregulation, while downregulation of FADS1 and FADS2 was unaffected. Thus, FADS3 AT were directly upregulated by LCPUFA by a PPARγ-dependent mechanism unrelated to regulation of other desaturases. This opposing pattern and mechanism of regulation suggests a dissimilar function for FADS3 AT compared to other FADS gene products. PMID:22398025

  16. Dietary n-3 long chain polyunsaturated fatty acids in allergy prevention and asthma treatment.

    PubMed

    Willemsen, Linette E M

    2016-08-15

    The rise in non-communicable diseases, such as allergies, in westernized countries links to changes in lifestyle and diet. N-3 long chain polyunsaturated fatty acids (LCPUFA) present in marine oils facilitate a favorable milieu for immune maturation and may contribute to allergy prevention. N-3 LCPUFA can suppress innate and adaptive immune activation and induce epigenetic changes. Murine studies convincingly show protective effects of fish oil, a source of n-3 LCPUFA, in food allergy and asthma models. Observational studies in human indicate that high dietary intake of n-3 LCPUFA and low intake of n-6 PUFA may protect against the development of allergic disease early in life. High n-6 PUFA intake is also associated with an increased asthma risk while n-3 LCPUFA may be protective and reduce symptoms. The quality of the marine oil used has impact on efficacy of allergy prevention and several observations link in particular n-3 LCPUFA DHA to allergy suppression. Randomized controlled trials indicate that optimal timing, duration and dosage of n-3 LC-PUFA is required to exert an allergy protective effect. Supplementation during early pregnancy and lactation has shown promising results regarding allergy prevention. However these findings should be confirmed in a larger cohort. Although clinical trials in asthma patients reveal no consistent clinical benefits of n-3 LCPUFA supplementation on lung function, it can suppress airway inflammation. Future food-pharma approaches may reveal whether adjunct therapy with dietary n-3 LCPUFA can improve allergy prevention or immunotherapy via support of allergen specific oral tolerance induction or contribute to the efficacy of drug therapy for asthma patients. PMID:27041644

  17. Impact of medium and long chain triglycerides consumption on appetite and food intake in overweight men

    PubMed Central

    St-Onge, Marie-Pierre; Mayrsohn, Brian; O’Keeffe, Majella; Kissileff, Harry R.; Choudhury, Arindam Roy; Laferrère, Blandine

    2014-01-01

    Background Medium chain triglycerides (MCT) enhance thermogenesis and may reduce food intake relative to long chain triglycerides (LCT). The goal of this study was to establish the effects of MCT on appetite and food intake and determine whether differences were due to differences in hormone concentrations. Methods Two randomized, crossover studies were conducted in which overweight men consumed 20 g of MCT or corn oil (LCT) at breakfast. Blood samples were obtained over 3 h. In Study 1 (n=10), an ad lib lunch was served after 3 h. In Study 2 (n=7), a pre-load containing 10 g of test oil was given at 3 h and lunch was served 1 h later. Linear mixed model analyses were performed to determine the effects of MCT and LCT oil on change in hormones and metabolites from fasting, adjusting for body weight. Correlations were computed between differences in hormones just before the test meals and differences in intakes after the two oils for Study 1 only. Results Food intake at the lunch test meal after the MCT pre-load (Study 2) was (mean ± SEM) 532 ± 389 kcal vs. 804 ± 486 kcal after LCT (P < 0.05). MCT consumption resulted in a lower rise in triglycerides (P = 0.014) and glucose (P = 0.066) and a higher rise in peptide YY (P = 0.017) and leptin (P = 0.036) compared to LCT (combined data). Correlations between differences in hormone levels (GLP-1, PYY) and differences in food intake were in the opposite direction to expectations. Conclusions MCT consumption reduced food intake acutely but this does not seem to be mediated by changes in GLP-1, PYY, and insulin. PMID:25074387

  18. Drug Discovery Opportunities and Challenges at G Protein Coupled Receptors for Long Chain Free Fatty Acids

    PubMed Central

    Holliday, Nicholas D.; Watson, Sarah-Jane; Brown, Alastair J. H.

    2011-01-01

    Discovery of G protein coupled receptors for long chain free fatty acids (FFAs), FFA1 (GPR40) and GPR120, has expanded our understanding of these nutrients as signaling molecules. These receptors have emerged as important sensors for FFA levels in the circulation or the gut lumen, based on evidence from in vitro and rodent models, and an increasing number of human studies. Here we consider their promise as therapeutic targets for metabolic disease, including type 2 diabetes and obesity. FFA1 directly mediates acute FFA-induced glucose-stimulated insulin secretion in pancreatic beta-cells, while GPR120 and FFA1 trigger release of incretins from intestinal endocrine cells, and so indirectly enhance insulin secretion and promote satiety. GPR120 signaling in adipocytes and macrophages also results in insulin sensitizing and beneficial anti-inflammatory effects. Drug discovery has focused on agonists to replicate acute benefits of FFA receptor signaling, with promising early results for FFA1 agonists in man. Controversy surrounding chronic effects of FFA1 on beta-cells illustrates that long term benefits of antagonists also need exploring. It has proved challenging to generate highly selective potent ligands for FFA1 or GPR120 subtypes, given that both receptors have hydrophobic orthosteric binding sites, which are not completely defined and have modest ligand affinity. Structure activity relationships are also reliant on functional read outs, in the absence of robust binding assays to provide direct affinity estimates. Nevertheless synthetic ligands have already helped dissect specific contributions of FFA1 and GPR120 signaling from the many possible cellular effects of FFAs. Approaches including use of fluorescent ligand binding assays, and targeting allosteric receptor sites, may improve further pre-clinical ligand development at these receptors, to exploit their unique potential to target multiple facets of diabetes. PMID:22649399

  19. Relationship between plasma free fatty acid, intramyocellular triglycerides and long-chain acylcarnitines in resting humans

    PubMed Central

    Kanaley, Jill A; Shadid, Samyah; Sheehan, Michael T; Guo, ZengKui; Jensen, Michael D

    2009-01-01

    We hypothesized that plasma non-esterified fatty acids (NEFA) are trafficked directly to intramyocellular long-chain acylcarnitines (imLCAC) rather than transiting intramyocellular triglycerides (imTG) on the way to resting muscle fatty acid oxidation. Overnight fasted adults (n= 61) received intravenous infusions of [U-13C]palmitate (0400–0830 h) and [U-13C]oleate (0800–1400 h) labelling plasma NEFA, imTG, imLCAC and im-non-esterified FA (imNEFA). Two muscle biopsies (0830 and 1400 h) were performed following 6 h, overlapping, sequential palmitate/oleate tracer infusions. Enrichment of plasma palmitate was ∼15 times greater than enrichment of imTG, imNEFA-palmitate and im-palmitoyl-carnitine. Fatty acid enrichment in LCAC was correlated with imTG and imNEFA; there was a significant correlation between imTG concentrations and imLCAC concentrations in women (r= 0.51, P= 0.005), but not men (r= 0.30, P= 0.11). We estimated that ∼11% of NEFA were stored in imTG. imTG NEFA storage was correlated only with NEFA concentrations (r= 0.52, P= 0.004) in women and with (r= 0.45, P= 0.02) in men. At rest, plasma NEFA are trafficked largely to imTG before they enter LCAC oxidative pools; thus, imTG are an important, central pool that regulates the delivery of fatty acids to the intracellular environment. Factors relating to plasma NEFA storage into imTG differ in men and women. PMID:19858228

  20. Nutritional regulation of long-chain PUFA biosynthetic genes in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Gregory, Melissa K; Collins, Robert O; Tocher, Douglas R; James, Michael J; Turchini, Giovanni M

    2016-05-28

    Most studies on dietary vegetable oil in rainbow trout (Oncorhynchus mykiss) have been conducted on a background of dietary EPA (20 : 5n-3) and DHA (22 : 6n-3) contained in the fishmeal used as a protein source in aquaculture feed. If dietary EPA and DHA repress their endogenous synthesis from α-linolenic acid (ALA, 18 : 3n-3), then the potential of ALA-containing vegetable oils to maintain tissue EPA and DHA has been underestimated. We examined the effect of individual dietary n-3 PUFA on the expression of the biosynthetic genes required for metabolism of ALA to DHA in rainbow trout. A total of 720 juvenile rainbow trout were allocated to twenty-four experimental tanks and assigned one of eight diets. The effect of dietary ALA, EPA or DHA, in isolation or in combination, on hepatic expression of fatty acyl desaturase (FADS)2a(Δ6), FADS2b(Δ5), elongation of very long-chain fatty acid (ELOVL)5 and ELOVL2 was examined after 3 weeks of dietary intervention. The effect of these diets on liver and muscle phospholipid PUFA composition was also examined. The expression levels of FADS2a(Δ6), ELOVL5 and ELOVL2 were highest when diets were high in ALA, with no added EPA or DHA. Under these conditions ALA was readily converted to tissue DHA. Dietary DHA had the largest and most consistent effect in down-regulating the gene expression of all four genes. The ELOVL5 expression was the least responsive of the four genes to dietary n-3 PUFA changes. These findings should be considered when optimising aquaculture feeds containing vegetable oils and/or fish oil or fishmeal to achieve maximum DHA synthesis. PMID:26987422

  1. Long-chain alkenone patterns in the Baltic Sea - An ocean-freshwater transition

    NASA Astrophysics Data System (ADS)

    Schulz, Hans-Martin; Schöner, Anne; Emeis, Kay-Christian

    2000-02-01

    Two different patterns of long-chain alkenones are found in surficial sediments of the Baltic Sea, which is the largest brackish water body on Earth. One pattern occurs in surficial sediments from the Western Baltic Sea where surface-water salinitiy is in excess of 7.7 PSU. It corresponds to the pattern produced by the marine coccolithophorid Emiliania huxleyi with a suite of C 37 di- to tetra-unsaturated methyl ketones and C 38 di- and tri-unsaturated methyl and ethyl ketones. A second pattern, resembling that found in lake sediments in lacking C 38 methyl ketones and having distinctly higher C 37:4 methyl ketone concentrations, dominates in surficial sediments of the eastern and northern Baltic Sea, where salinities are lower than 7.7 PSU. Correspondence of sea-surface temperature (SST) estimates from the U37K and U37K' indices (using marine calibrations) with mean SST in the euphotic zone from July-August (the main haptophyte growth season) is poor. Thus, these indices are not applicable as sedimentary thermometers in surficial sediments of the Baltic Sea. The different patterns may either reflect the salinity-dependent occurrence of specific alkenone producers or changes in the alkenone biosynthesis due to physiological stress caused by salinity variations. Furthermore, advection of saline and oxygenated North Sea water may transport marine algal material characterized by a marine E. huxleyi-like alkenone pattern into the western Baltic Sea, thus covering the signature of the local alkenone producers with a Baltic Sea pattern.

  2. Metabolic engineering of the omega-3 long chain polyunsaturated fatty acid biosynthetic pathway into transgenic plants.

    PubMed

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

    2012-04-01

    Omega-3 (ω-3) very long chain polyunsaturated fatty acids (VLC-PUFAs) such as eicosapentaenoic acid (EPA; 20:5 Δ5,8,11,14,17) and docosahexaenoic acid (DHA; 22:6 Δ4,7,10,13,16,19) have been shown to have significant roles in human health. Currently the primary dietary source of these fatty acids are marine fish; however, the increasing demand for fish and fish oil (in particular the expansion of the aquaculture industry) is placing enormous pressure on diminishing marine stocks. Such overfishing and concerns related to pollution in the marine environment have directed research towards the development of a viable alternative sustainable source of VLC-PUFAs. As a result, the last decade has seen many genes encoding the primary VLC-PUFA biosynthetic activities identified and characterized. This has allowed the reconstitution of the VLC-PUFA biosynthetic pathway in oilseed crops, producing transgenic plants engineered to accumulate ω-3 VLC-PUFAs at levels approaching those found in native marine organisms. Moreover, as a result of these engineering activities, knowledge of the fundamental processes surrounding acyl exchange and lipid remodelling has progressed. The application of new technologies, for example lipidomics and next-generation sequencing, is providing a better understanding of seed oil biosynthesis and opportunities for increasing the production of unusual fatty acids. Certainly, it is now possible to modify the composition of plant oils successfully, and, in this review, the most recent developments in this field and the challenges of producing VLC-PUFAs in the seed oil of higher plants will be described. PMID:22291131

  3. Omega-3 long chain fatty acid "bioavailability": a review of evidence and methodological considerations.

    PubMed

    Ghasemifard, Samaneh; Turchini, Giovanni M; Sinclair, Andrew J

    2014-10-01

    This review considers the bioavailability of different forms of omega-3 long chain polyunsaturated fatty acids (n-3 LC-PUFA), including ethyl esters (EEs), free fatty acids (FFAs), triacylglycerols (TAGs) and phospholipids (PLs). The retrieved studies include short-term and longer-term studies in humans, and a number of animal studies, which were highly heterogeneous in their design making it difficult to draw substantiated conclusions. The apparent bioavailability (as defined by the authors of these studies) seems to be lowest for the EE form and highest for the FFA form, whilst no conclusion can be made for TAG versus PL from human data. Animal studies suggest that there are substantial differences in the bioavailability of PL form of LC-PUFA compared with the TAG form. This apparent limited knowledge and understanding is fundamentally driven by methodological limitations of these studies. The major limitations with the studies to date include: (between studies) loose definition of the term "bioavailability", lack of standardisation of analytical methodology, and differences in which blood compartment was analysed; (within a study) failure to provide equal amounts the n-3 LC-PUFA of the different forms being compared, failure to provide the dose of n-3 LC-PUFA on a body weight basis, failure to measure fatty acid excretion, failure to control the total fat intake, and failure to adequately power the studies from a statistical point of view. This review has laid out a set of suggestions and criteria for conducting future studies on the bioavailability of different chemical forms of n-3 LC-PUFA. PMID:25218856

  4. Controlled formation of ag nanoparticles by means of long-chain sodium polyacrylates in dilute solution.

    PubMed

    Huber, Klaus; Witte, Thomas; Hollmann, Jutta; Keuker-Baumann, Susanne

    2007-02-01

    A new tool is presented to control formation of Ag nanoparticles. Small amounts of silver ions were added to dilute solutions of long-chain sodium polyacrylates (NaPA). Four NaPA samples covering a molar mass regime of 97 kD < or = Mw < or = 650 kD have been used. With amounts of added Ag(+) as low as 1-2% of the COO(-) groups of the polyanionic chains, significant changes could already be induced in the NaPA coils with 650 kD. If the NaPA concentration was kept below 0.1 g/L, the coils with 650 kD exhibited a significant coil shrinking in stable solutions. At larger NaPA concentrations, addition of Ag+ initiates an aggregation of the polyacrylate coils toward compact structures. Coil shrinking and aggregation was revealed by means of time-resolved static light scattering. If exposed to UV-radiation, small Ag particles formed within the shrunken anionic polyacrylate coils. The Ag nanoparticles were identified by means of an enhanced light scattering and a characteristic plasmon absorption band around 410 nm. No such Ag particle formation could be observed even at 5 times larger concentrations of Ag(+) and NaPA if the two smallest polyacrylate samples have been used under otherwise equal conditions. This molar mass sensitive response of NaPA to Ag(+)-addition suggests an interesting phenomenon: if the coil size of the NaPa chains, which act as Ag(+) collectors, is large enough, local Ag(+) concentration in these coil-shaped Ag(+) containers exceeds a critical value, and irradiation with UV generates Ag nanoparticles. PMID:17263389

  5. Antibacterial activity of long-chain polyunsaturated fatty acids against Propionibacterium acnes and Staphylococcus aureus.

    PubMed

    Desbois, Andrew P; Lawlor, Keelan C

    2013-11-01

    New compounds are needed to treat acne and superficial infections caused by Propionibacterium acnes and Staphylococcus aureus due to the reduced effectiveness of agents used at present. Long-chain polyunsaturated fatty acids (LC-PUFAs) are attracting attention as potential new topical treatments for Gram-positive infections due to their antimicrobial potency and anti-inflammatory properties. This present study aimed to investigate the antimicrobial effects of six LC-PUFAs against P. acnes and S. aureus to evaluate their potential to treat infections caused by these pathogens. Minimum inhibitory concentrations were determined against P. acnes and S. aureus, and the LC-PUFAs were found to inhibit bacterial growth at 32-1024 mg/L. Generally, P. acnes was more susceptible to the growth inhibitory actions of LC-PUFAs, but these compounds were bactericidal only for S. aureus. This is the first report of antibacterial activity attributed to 15-hydroxyeicosapentaenoic acid (15-OHEPA) and 15-hydroxyeicosatrienoic acid (HETrE), while the anti-P. acnes effects of the six LC-PUFAs used herein are novel observations. During exposure to the LC-PUFAs, S. aureus cells were killed within 15-30 min. Checkerboard assays demonstrated that the LC-PUFAs did not antagonise the antimicrobial potency of clinical agents used presently against P. acnes and S. aureus. However, importantly, synergistic interactions against S. aureus were detected for combinations of benzoyl peroxide with 15-OHEPA, dihomo-γ-linolenic acid (DGLA) and HETrE; and neomycin with 15-OHEPA, DGLA, eicosapentaenoic acid, γ-linolenic acid and HETrE. In conclusion, LC-PUFAs warrant further evaluation as possible new agents to treat skin infections caused by P. acnes and S. aureus, especially in synergistic combinations with antimicrobial agents already used clinically. PMID:24232668

  6. Antibacterial Activity of Long-Chain Polyunsaturated Fatty Acids against Propionibacterium acnes and Staphylococcus aureus

    PubMed Central

    Desbois, Andrew P.; Lawlor, Keelan C.

    2013-01-01

    New compounds are needed to treat acne and superficial infections caused by Propionibacterium acnes and Staphylococcus aureus due to the reduced effectiveness of agents used at present. Long-chain polyunsaturated fatty acids (LC-PUFAs) are attracting attention as potential new topical treatments for Gram-positive infections due to their antimicrobial potency and anti-inflammatory properties. This present study aimed to investigate the antimicrobial effects of six LC-PUFAs against P. acnes and S. aureus to evaluate their potential to treat infections caused by these pathogens. Minimum inhibitory concentrations were determined against P. acnes and S. aureus, and the LC-PUFAs were found to inhibit bacterial growth at 32–1024 mg/L. Generally, P. acnes was more susceptible to the growth inhibitory actions of LC-PUFAs, but these compounds were bactericidal only for S. aureus. This is the first report of antibacterial activity attributed to 15-hydroxyeicosapentaenoic acid (15-OHEPA) and 15-hydroxyeicosatrienoic acid (HETrE), while the anti-P. acnes effects of the six LC-PUFAs used herein are novel observations. During exposure to the LC-PUFAs, S. aureus cells were killed within 15–30 min. Checkerboard assays demonstrated that the LC-PUFAs did not antagonise the antimicrobial potency of clinical agents used presently against P. acnes and S. aureus. However, importantly, synergistic interactions against S. aureus were detected for combinations of benzoyl peroxide with 15-OHEPA, dihomo-γ-linolenic acid (DGLA) and HETrE; and neomycin with 15-OHEPA, DGLA, eicosapentaenoic acid, γ-linolenic acid and HETrE. In conclusion, LC-PUFAs warrant further evaluation as possible new agents to treat skin infections caused by P. acnes and S. aureus, especially in synergistic combinations with antimicrobial agents already used clinically. PMID:24232668

  7. The possible role of long-chain, omega-3 fatty acids in human brain phylogeny.

    PubMed

    Chamberlain, J G

    1996-01-01

    I propose that one of the key factors in human encephalization was increased HUFA intake, especially long-chain, omega-3 fatty acids from aquatic and terrestial meat source. This provided the needed neural membrane fluidity and transmitter/receptor functions for rapid acquisition of more advanced human traits and allowed the expansion of H. erectus into more northern climates. The human brain initially could build ecophenotypically, or adaptive/directed mutationally upon previously evolved mammalian sensor/motor structures, and could rapidly expand cognitive functions within a few million years; as more niches were invaded, more brain diversity was needed to guarantee reproductive success. The metabolically expensive and expanding brain was nutritionally and biochemically set, as it were, for rapid accommodation to tool making, rock throwing, culture language, electronics, and the eventual endless discussion and writings about the brain itself, the evolution of consciousness, and the mid-bran problem [107]. All of this fits, no matter which theory of human evolution one adheres to--i.e., out of Africa, multiregional, etc.--or even the precis fossil chronology [108]. This proposal, based as it is on known facts and certain assumptions appears logical, simple, and satisfying, but it may be wrong. Yet Charles Darwin himself would have approved, because as he so aptly said: false facts are highly injurious to the progress of science, for they often endure long; but false views, if supported by some evidence do little harm for everyone takes a salutory pleasure in providing their falseness; and when this is done our path toward error is closed and the road to truth is often opened. [109]. PMID:8657555

  8. On the appearance of traffic jams in a long chain with a shortcut in the bulk

    NASA Astrophysics Data System (ADS)

    Bunzarova, N. Zh.; Pesheva, N. C.; Brankov, J. G.

    2015-11-01

    The Totally Asymmetric Simple Exclusion Process (TASEP) is studied on open long chains with a shunted section between two simple chain segments in the maximum current phase. The reference case, when the two branches are chosen with equal probability, is considered. The conditions for the occurrence of traffic jams and their properties are investigated both within the effective rates approximation and by extensive Monte Carlo simulations for arbitrary length of the shortcut. Our main results are: (1) For any length of the shortcut and any values of the external rates in the domain of the maximum current phase, there exists a position of the shortcut where the shunted segment is in a phase of coexistence with a completely delocalized domain wall; (2) The main features of the coexistence phase and the density profiles in the whole network are well described by the domain wall theory. Apart from the small inter-chain correlations, they depend only on the current through the shortcut; (3) The model displays unexpected features: (a) the current through the longer shunted segment is larger than the current through the shortcut, and (b) the delocalized domain wall in the coexistence phase of the long shunted segment induces similar behavior even in shortcuts containing a small number of sites; (4) From the viewpoint of vehicular traffic, most comfortable conditions for the drivers are provided when the shortcut is shifted downstream from the position of coexistence, when both the shunted segment and the shortcut exhibit low-density lamellar flow. Most unfavorable is the opposite case of upstream shifted shortcut, when both the shunted segment and the shortcut are in a high-density phase describing congested traffic of slowly moving cars. The above results are relevant also to phenomena like crowding of molecular motors moving along twisted protofilaments.

  9. Omega-3 long-chain fatty acids strongly induce angiopoietin-like 4 in humans.

    PubMed

    Brands, Myrte; Sauerwein, Hans P; Ackermans, Mariette T; Kersten, Sander; Serlie, Mireille J

    2013-03-01

    Angiopoietin-like 4 (ANGPTL4) is a regulator of LPL activity. In this study we examined whether different fatty acids have a differential effect on plasma ANGPTL4 levels during hyperinsulinemia in healthy lean males. In 10 healthy lean males, 3 hyperinsulinemic euglycemic clamps were performed during concomitant 6 h intravenous infusion of soybean oil (Intralipid® rich in PUFA), olive oil (Clinoleic® rich in MUFA) and control saline. In 10 other healthy lean males, 2 hyperinsulinemic clamps were performed during infusion of a mixed lipid emulsion containing a mixture of fish oil (FO), medium-chain triglycerides (MCTs), and long-chain triglycerides (LCTs) (FO/MCT/LCT; SMOFlipid®) or saline. FFA levels of approximately 0.5 mmol/l were reached during each lipid infusion. Plasma ANGPTL4 decreased during hyperinsulinemia by 32% (18-52%) from baseline. This insulin-mediated decrease in ANGPTL4 concentrations was partially reduced during concomitant infusion of olive oil and completely blunted during concomitant infusion of soybean oil and FO/MCT/LCT. The reduction in insulin sensitivity was similar between all lipid infusions. In accordance, incubation of rat hepatoma cells with the polyunsaturated fatty acid C22:6 increased ANGPTL4 expression by 70-fold, compared with 27-fold by the polyunsaturated fatty acid C18:2, and 15-fold by the monounsaturated fatty acid C18:1. These results suggest that ANGPTL4 is strongly regulated by fatty acids in humans, and is also dependent on the type of fatty acid. PMID:23319744

  10. Synthesis of Long-Chain Chitooligosaccharides by a Hypertransglycosylating Processive Endochitinase of Serratia proteamaculans 568

    PubMed Central

    Purushotham, Pallinti

    2012-01-01

    We describe the heterologous expression and characterization of a 407-residue single-domain glycosyl hydrolase family 18 chitinase (SpChiD) from Gram-negative Serratia proteamaculans 568 that has unprecedented catalytic properties. SpChiD was optimally active at pH 6.0 and 40°C, where it showed a Km of 83 mg ml−1, a kcat of 3.9 × 102 h−1, and a kcat/Km of 4.7 h mg−1 ml−1 on colloidal chitin. On chitobiose, the Km, kcat, and kcat/Km were 203 μM, 1.3 × 102 h−1, and 0.62 h−1 μM−1, respectively. Hydrolytic activity on chitooligosaccharides (CHOS) and colloidal chitin indicated that SpChiD was an endo-acting processive enzyme, with the unique ability to convert released chitobiose to N-acetylglucosamine, the major end product. SpChiD showed hyper transglycosylation (TG) with trimer-hexamer CHOS substrates, generating considerable amounts of long-chain CHOS. The TG activity of SpChiD was dependent on both the length and concentration of the oligomeric substrate and also on the enzyme concentration. The length and amount of accumulated TG products increased with increases in the length of the substrate and its concentration and decreased with increases in the enzyme concentration. The SpChiD bound to insoluble and soluble chitin substrates despite the absence of accessory domains. Sequence alignments and structural modeling indicated that SpChiD would have a deep substrate-binding groove lined with aromatic residues, which is characteristic of processive enzymes. SpChiD shows a combination of properties that seems rare among family 18 chitinases and that may resemble the properties of human chitotriosidase. PMID:22685288

  11. Neurorestorative targets of dietary long-chain omega-3 fatty acids in neurological injury.

    PubMed

    Figueroa, Johnny D; De Leon, Marino

    2014-08-01

    Long-chain omega-3 polyunsaturated fatty acids (LC-O3PUFAs) exhibit therapeutic potential for the treatment and prevention of the neurological deficits associated with spinal cord injury (SCI). However, the mechanisms implicated in these protective responses remain unclear. The objective of the present functional metabolomics study was to identify and define the dominant metabolic pathways targeted by dietary LC-O3PUFAs. Sprague-Dawley rats were fed rodent purified chows containing menhaden fish oil-derived LC-O3PUFAs for 8 weeks before being subjected to sham or spinal cord contusion surgeries. We show, through untargeted metabolomics, that dietary LC-O3PUFAs regulate important biochemical signatures associated with amino acid metabolism and free radical scavenging in both the injured and sham-operated spinal cord. Of particular significance, the spinal cord metabolome of animals fed with LC-O3PUFAs exhibited reduced glucose levels (-48 %) and polar uncharged/hydrophobic amino acids (less than -20 %) while showing significant increases in the levels of antioxidant/anti-inflammatory amino acids and peptides metabolites, including β-alanine (+24 %), carnosine (+33 %), homocarnosine (+27 %), kynurenine (+88 %), when compared to animals receiving control diets (p < 0.05). Further, we found that dietary LC-O3PUFAs impacted the levels of neurotransmitters and the mitochondrial metabolism, as evidenced by significant increases in the levels of N-acetylglutamate (+43 %) and acetyl CoA levels (+27 %), respectively. Interestingly, this dietary intervention resulted in a global correction of the pro-oxidant metabolic profile that characterized the SCI-mediated sensorimotor dysfunction. In summary, the significant benefits of metabolic homeostasis and increased antioxidant defenses unlock important neurorestorative pathways of dietary LC-O3PUFAs against SCI. PMID:24740740

  12. Polymorphism of a long-chain cycloparaffin (CH2)120.

    PubMed

    Ihn, K J; Tsuji, M; Kawaguchi, A; Katayama, K

    1992-01-15

    The polymorphism of a long-chain cycloparaffin (CH2)120 and chain packing in its crystals were discussed on the basis of some results obtained mainly by transmission electron microscopy. Monoclinic and orthorhombic single crystals of (CH2)120 were isothermally grown together from a dilute solution in p-xylene. Lozenge-shaped orthorhombic single crystals were more frequently observed than lath-shaped monoclinic ones. The basal surfaces of orthorhombic and monoclinic single crystal platelets were decorated with vapor-deposited polyethylene [PE]. Orthorhombic single crystals of (CH2)120 with the (110) twin boundary and monoclinic ones with the (100) twin boundary were also observed. Rod-like edge-on crystals of (CH2)120 were grown from a dilute p-xylene solution onto the (001) surface of alkali halides. The crystal system of the (CH2)120 edge-on crystals depended on the kind of substrate. The monoclinic crystal was grown on NaCl, the orthorhombic one on KBr and KCl. The monoclinic form of (CH2)120 edge-on crystal was transformed to the orthorhombic one by annealing on NaCl. In both monoclinic and orthorhombic edge-on crystals, the molecular plane determined by two zigzag stems in a molecule of (CH2)120 was parallel to the substrate surface and the molecular axis (crystallographic c-axis) was perpendicular to the longer side of the rod-like edge-on crystals. The sub-cell dimensions of the stem chains in both forms of (CH2)120 crystals were very similar to those of monoclinic and orthorhombic PE crystals, respectively. PMID:1372192

  13. PTH1 Receptor Is Involved in Mediating Cellular Response to Long-Chain Polyunsaturated Fatty Acids

    PubMed Central

    Chachisvilis, Mirianas

    2012-01-01

    The molecular pathways by which long chain polyunsaturated fatty acids (LCPUFA) influence skeletal health remain elusive. Both LCPUFA and parathyroid hormone type 1 receptor (PTH1R) are known to be involved in bone metabolism while any direct link between the two is yet to be established. Here we report that LCPUFA are capable of direct, PTH1R dependent activation of extracellular ligand-regulated kinases (ERK). From a wide range of fatty acids studied, varying in chain length, saturation, and position of double bonds, eicosapentaenoic (EPA) and docosahexaenoic fatty acids (DHA) caused the highest ERK phosphorylation. Moreover, EPA potentiated the effect of parathyroid hormone (PTH(1–34)) in a superagonistic manner. EPA or DHA dependent ERK phosphorylation was inhibited by the PTH1R antagonist and by knockdown of PTH1R. Inhibition of PTH1R downstream signaling molecules, protein kinases A (PKA) and C (PKC), reduced EPA and DHA dependent ERK phosphorylation indicating that fatty acids predominantly activate G-protein pathway and not the β-arrestin pathway. Using picosecond time-resolved fluorescence microscopy and a genetically engineered PTH1R sensor (PTH-CC), we detected conformational responses to EPA similar to those caused by PTH(1–34). PTH1R antagonist blocked the EPA induced conformational response of the PTH-CC. Competitive binding studies using fluorescence anisotropy technique showed that EPA and DHA competitively bind to and alter the affinity of PTH1 receptor to PTH(1–34) leading to a superagonistic response. Finally, we showed that EPA stimulates protein kinase B (Akt) phosphorylation in a PTH1R-dependent manner and affects the osteoblast survival pathway, by inhibiting glucocorticoid-induced cell death. Our findings demonstrate for the first time that LCPUFAs, EPA and DHA, can activate PTH1R receptor at nanomolar concentrations and consequently provide a putative molecular mechanism for the action of fatty acids in bone. PMID:23300710

  14. Neurorestorative targets of dietary long-chain omega-3 fatty acids in neurological injury

    PubMed Central

    Figueroa, Johnny D.; De Leon, Marino

    2014-01-01

    Long-chain omega-3 polyunsaturated fatty acids (LC-O3PUFAs) exhibit therapeutic potential for the treatment and prevention of the neurological deficits associated with spinal cord injury (SCI). However, the mechanisms implicated in these protective responses remain unclear. The objective of the present functional metabolomics study was to identify and define the dominant metabolic pathways targeted by dietary LC-O3PUFAs. Sprague-Dawley rats were fed rodent purified chows containing menhaden fish oil-derived LC-O3PUFAs for 8 weeks before being subjected to sham or spinal cord contusion surgeries. We show, through untargeted metabolomics, that dietary LC-O3PUFAs regulate important biochemical signatures associated with amino acid metabolism and free radical scavenging in both the injured and sham-operated spinal cord. Of particular significance, the spinal cord metabolome of animals fed with LC-O3PUFAs exhibited reduced glucose levels (−48%) and polar uncharged/hydrophobic amino acids (<−20%) while showing significant increases in the levels of antioxidant/anti-inflammatory amino acids and peptides metabolites, including β-alanine (+24%), carnosine (+33%), homocarnosine (+27%), kynurenine (+88%), when compared to animals receiving control diets (p < 0.05). Further, we found that dietary LC-O3PUFAs impacted the levels of neurotransmitters and the mitochondrial metabolism, as evidenced by significant increases in the levels of N-acetylglutamate (+43%) and acetyl-CoA levels (+27%), respectively. Interestingly, this dietary intervention resulted in a global correction of the pro-oxidant metabolic profile that characterized the SCI-mediated sensorimotor dysfunction. In summary, the significant benefits of metabolic homeostasis and increased antioxidant defenses unlock important neurorestorative pathways of dietary LC-O3PUFAs against SCI. PMID:24740740

  15. Energetics and kinetics of anaerobic aromatic and fatty acid degradation. Progress report, March 1992--June 1995

    SciTech Connect

    McInerney M.J.

    1995-06-23

    Factors affecting the rate and extent of benzoate degradation by anaerobic syntrophic consortia were studied. Cocultures of a syntrophic benzoate degrader, strain SB, with a hydrogen/formate-using sulfate reducer degraded benzoate to a threshold that depended on the amount of substrate and acetate present. The benzoate threshold was not a function of the inhibition of benzoate degradation capacity by acetate or the toxicity of the undissociated form of acetate. Rather, a critical or minimal Gibb`s free energy value may exist where thermodynamic constraints preclude further benzoate degradation. A sensitive assay to detect low formate concentrations was developed to measure the formate levels when the benzoate threshold was reached. We showed that increased acetate concentrations, even when hydrogen and formate levels are low, affects the extent of benzoate degradation, implicating the importance of interspecies acetate transfer. In addition to benzoate, various saturated and unsaturated fatty acids, 2-methylbutyrate, and methyl esters of fatty acids supported growth in coculture with a hydrogen-using partner. SB is the only syntrophic bacterium known to use both benzoate and fatty acids. Phylogenetic analysis showed that SB clustered with sulfate reducers in the delta subclass of the Proteobacteria. SB grew well in coculture with Desulfoarculus baarsii, a sulfate reducer that uses formate but not hydrogen. This unequivocally shows that SB can grow by interspecies formate transfer.

  16. Assessing the role of spatial structure on cell-specific activity and interactions within uncultured methane-oxidizing syntrophic consortia (Invited)

    NASA Astrophysics Data System (ADS)

    Orphan, V. J.; McGlynn, S.; Chadwick, G.; Dekas, A.; Green-Saxena, A.

    2013-12-01

    Sulfate-coupled anaerobic oxidation of methane is catalysed through symbiotic associations between archaea and sulphate-reducing bacteria and represents the dominant sink for methane in the oceans. These methane-oxidizing symbiotic consortia form well-structured multi-celled aggregations in marine methane seeps, where close spatial proximity is believed to be essential for efficient exchange of substrates between syntrophic partners. The nature of this interspecies metabolic relationship is still unknown however there are a number of hypotheses regarding the electron carrying intermediate and ecophysiology of the partners, each of which should be affected by, and influence, the spatial arrangement of archaeal and bacterial cells within aggregates. To advance our understanding of the role of spatial structure within naturally occurring environmental consortia, we are using spatial statistical methods combined with fluorescence in situ hybridization and high-resolution nanoscale secondary ion mass spectrometry (FISH-nanoSIMS) to quantify the effect of spatial organization and intra- and inter-species interactions on cell-specific microbial activity within these diverse archaeal-bacterial partnerships.

  17. Anaerobic Process.

    PubMed

    Li, Wei-Zun; Qian, Yang; Chang, Chein-Chi; Ju, Meiting

    2015-10-01

    A review of the literature published in 2014 on the focus of Anaerobic Process. It is divided into the following sections. •Pretreatment •Organic waste •multiple-stage co-digestion •Process Methodology and Technology. PMID:26420080

  18. Identification of long-chain perfluorinated acids in biota from the Canadian Arctic.

    PubMed

    Martin, Jonathan W; Smithwick, Marla M; Braune, Birgit M; Hoekstra, Paul F; Muir, Derek C G; Mabury, Scott A

    2004-01-15

    Recently it was discovered that humans and animals from various urban and remote global locations contained a novel class of persistent fluorinated contaminants, the most pervasive of which was perfluorooctane sulfonate (PFOS). Lower concentrations of perfluorooctanoate, perfluorohexane sulfonate, and heptadecafluorooctane sulfonamide have also been detected in various samples. Although longer perfluoroalkyl carboxylates (PFCAs) are used in industry and have been detected in fish following a spill of aqueous film forming foam, no studies have been conducted to examine the widespread occurrence of long-chain PFCAs (e.g., CF3(CF2)xCOO-, where x > 6). To provide a preliminary assessment of fluorinated contaminants, including PFCAs, in the Canadian Arctic, polar bears, ringed seals, arctic fox, mink, common loons, northern fulmars, black guillemots, and fish were collected at various locations in the circumpolar region. PFOS was the major contaminant detected in most samples and in polar bear liver was the most prominent organohalogen (mean PFOS = 3.1 microg/g wet weight) compared to individual polychlorinated biphenyl congeners, chlordane, or hexachlorocyclohexane-related chemicals in fat. Using two independent mass spectral techniques, it was confirmed that all samples also contained ng/g concentrations of a homologous series of PFCAs, ranging in length from 9 to 15 carbons. Sum concentrations of PFCAs (sum(PFCAs)) were lower than total PFOS equivalents (sum(PFOS)) in all samples except for mink. In mink, perfluorononanoate (PFNA) concentrations exceeded PFOS concentrations, indicating that PFNA and other PFCAs should be considered in future risk assessments. Mammals feeding at higher trophic levels had greater concentrations of PFOS and PFCAs than mammals feeding at lower trophic positions. In general, odd-length PFCAs exceeded the concentration of even-length PFCAs, and concentrations decreased with increasing chain length in mammals. PFOS and PFCA concentrations

  19. Fatigue and fracture toughness of acrylic bone cements modified with long-chain amine activators.

    PubMed

    Deb, S; Lewis, G; Janna, S W; Vazquez, B; San Roman, J

    2003-11-01

    The composition of acrylic bone cement has been identified as one of the important parameters affecting its mechanical properties and may, in turn, ultimately influence the longevity of a cemented arthroplasty. Our aim in this study was to determine the influence of change of one compositional variable, the activator, on the fatigue performance and fracture toughness of specimens of the fully cured cement. To that end, three sets of cements were prepared, containing either the conventional activator, 4-N,N dimethyl p-toluidine (DMPT), or novel ones that are tertiary amines based on long-chain fatty acids, that is, 4-N,N dimethylaminobenzyl oleate (DMAO) and 4-N,N dimethylaminobenzyl laurate (DMAL). In the fatigue tests, the specimens were subjected to tension-tension loading, and the results (number of cycles to failure, Nf) were analyzed using the linearized form of the three-parameter Weibull equation. The fracture toughness (KIc) tests were conducted with rectangular compact tension specimens. All fracture surfaces were subsequently examined with scanning electron microscopy. We found that the Weibull mean fatigue lives for specimens fabricated using the DMPT, DMAL, and DMAO containing cements were 272,823, 453,551, and 583,396 cycles, respectively. The corresponding values for KIc were 1.94 +/- 0.05, 2.06 +/- 0.09, and 2.00 +/- 0.07 MPa radical m, respectively. Statistical analyses showed that for both the DMAL- and DMAO-containing cements, the mean values of Nf were significantly higher compared to the corresponding value for the DMPT-containing cement (Mann-Whitney test; alpha < 0.10). This result is attributed to the higher molecular weights of the former cements compared to the latter. The same trend was found for the mean KIc values (Mann-Whitney test; alpha < 0.05), with the trend being explained in terms of the differences seen in the crack morphologies. These results thus demonstrate that these novel amines are viable alternatives to DMPT for

  20. Plasma lipidomics analysis finds long chain cholesteryl esters to be associated with Alzheimer's disease

    PubMed Central

    Proitsi, P; Kim, M; Whiley, L; Pritchard, M; Leung, R; Soininen, H; Kloszewska, I; Mecocci, P; Tsolaki, M; Vellas, B; Sham, P; Lovestone, S; Powell, J F; Dobson, R J B; Legido-Quigley, C

    2015-01-01

    There is an urgent need for the identification of Alzheimer's disease (AD) biomarkers. Studies have now suggested the promising use of associations with blood metabolites as functional intermediate phenotypes in biomedical and pharmaceutical research. The aim of this study was to use lipidomics to identify a battery of plasma metabolite molecules that could predict AD patients from controls. We performed a comprehensive untargeted lipidomic analysis, using ultra-performance liquid chromatography/mass spectrometry on plasma samples from 35 AD patients, 40 elderly controls and 48 individuals with mild cognitive impairment (MCI) and used multivariate analysis methods to identify metabolites associated with AD status. A combination of 10 metabolites could discriminate AD patients from controls with 79.2% accuracy (81.8% sensitivity, 76.9% specificity and an area under curve of 0.792) in a novel test set. Six of the metabolites were identified as long chain cholesteryl esters (ChEs) and were reduced in AD (ChE 32:0, odds ratio (OR)=0.237, 95% confidence interval (CI)=0.10–0.48, P=4.19E−04; ChE 34:0, OR=0.152, 95% CI=0.05–0.37, P=2.90E−04; ChE 34:6, OR=0.126, 95% CI=0.03–0.35, P=5.40E−04; ChE 32:4, OR=0.056, 95% CI=0.01–0.24, P=6.56E−04 and ChE 33:6, OR=0.205, 95% CI=0.06–0.50, P=2.21E−03, per (log2) metabolite unit). The levels of these metabolites followed the trend control>MCI>AD. We, additionally, found no association between cholesterol, the precursor of ChE and AD. This study identified new ChE molecules, involved in cholesterol metabolism, implicated in AD, which may help identify new therapeutic targets; although, these findings need to be replicated in larger well-phenotyped cohorts. PMID:25585166

  1. Evolution of the syntrophic interaction between Desulfovibrio vulgaris and Methanosarcina barkeri: involvement of an ancient horizontal gene transfer

    SciTech Connect

    Scholten, Johannes C.; Culley, David E.; Brockman, Fred J.; Wu, Gang; Zhang, Weiwen

    2007-01-05

    The sulfate reducing bacteria Desulfovibrio vulgaris and the methanogenic archaea Methanosarcina barkeri can grow syntrophically on lactate. In this study, three functionally unknown genes of D. vulgaris, DVU2103, DVU2104 and DVU2108, were found to be up-regulated 2-4 fold following the lifestyle shift from syntroph to sulfatereducer; moreover, none of these genes were regulated when D. vulgaris was grown alone in various pure culture conditions. These results suggest that these genes may play roles related to the lifestyle change of D. vulgaris from syntroph to sulfate reducer. This hypothesis is further supported by phylogenomic analyses showing that homologies of these genes were only narrowly present in several groups of bacteria, most of which are restricted to a syntrophic life-style, such as Pelobacter carbinolicus, Syntrophobacter fumaroxidans, Syntrophomonas wolfei and Syntrophus aciditrophicus. Phylogenetic analysis showed that the genes tended to be clustered with archaeal genera, and they were rooted on archaeal species in the phylogenetic trees, suggesting that they originated from an archaeal methanogen and were horizontally transferred to a common ancestor of delta- Proteobacteria, Clostridia and Thermotogae. While lost in most species during evolution, these genes appear to have been retained in bacteria capable of syntrophic relationships, probably due to their providing a selective advantage. In addition, no significant bias in codon and amino acid usages was detected between these genes and the rest of the D. vulgaris genome, suggesting these gene transfers may have occurred early in the evolutionary history so that sufficient time has elapsed to allow an adaptation to the codon and amino acid usages of D. vulgaris. This report provides novel insights into the origin and evolution of bacterial genes involved in the syntrophic lifestyle.

  2. Identification and Biological Activities of Long-Chain Peptaibols Produced by a Marine-Derived Strain of Trichoderma longibrachiatum.

    PubMed

    Mohamed-Benkada, Mustapha; François Pouchus, Yves; Vérité, Philippe; Pagniez, Fabrice; Caroff, Nathalie; Ruiz, Nicolas

    2016-05-01

    Six long-chain peptaibols, 1 - 6, were identified from agar cultures of a marine-derived Trichoderma longibrachiatum Rifai strain (MMS151) isolated from blue mussels. The structure elucidation was carried out using electrospray ionization ion trap mass spectrometry (ESI-IT-MS) and GC/EI-MS. The long-chain peptaibols exhibited the general building scheme Ac-Aib-Ala-Aib-Ala-Aib-XXX-Gln-Aib-Vxx-Aib-Gly-XXX-Aib-Pro-Vxx-Aib-XXX-Gln-Gln-Pheol and were similar or identical to recurrent 20-residue peptaibols produced by Trichoderma spp. Three new sequences were identified and were called longibrachins A-0, A-II-a, and A-IV-b. The isolated peptaibols were assayed for cytotoxic, antibacterial, and antifungal activities, and acute toxicity on Dipteran larvae. PMID:27009018

  3. Inborn Errors of Long Chain Fatty Acid β-Oxidation Link Neural Stem Cell Self-Renewal to Autism

    PubMed Central

    Xie, Zhigang; Jones, Albert; Deeney, Jude T; Hur, Seong Kwon; Bankaitis, Vytas A

    2016-01-01

    SUMMARY Inborn errors of metabolism (IEMs) occur with high incidence in human populations. Especially prevalent among these are inborn deficiencies in fatty acid β-oxidation (FAO) clinically associated with developmental neuropsychiatric disorders, including autism. We now report that neural stem cell (NSC)-autonomous insufficiencies in activity of TMLHE (an autism-risk factor that supports long-chain FAO by catalyzing carnitine biosynthesis), of CPT1A (enzyme required for long-chain FAO transport into mitochondria), or of fatty acid mobilization from lipid droplets reduced NSC pools in mouse embryonic neocortex. Lineage tracing experiments demonstrated that reduced flux through the FAO pathway potentiated NSC symmetric differentiating divisions at the expense of self-renewing stem cell division modes. The collective data reveal a key role for FAO in controlling NSC-to-IPC transition in mammalian embryonic brain, and suggest NSC self-renewal as a cellular mechanism underlying the association between IEMs and autism. PMID:26832401

  4. Activation of a novel long-chain free fatty acid generation and export system in mitochondria of diabetic rat hearts.

    PubMed

    Gerber, Lamar K; Aronow, Bruce J; Matlib, Mohammed A

    2006-12-01

    A number of reports indicate that a long-chain free fatty acid export system may be operating in mitochondria. In this study, we sought evidence of its existence in rat heart mitochondria. To determine its potential role, we also sought evidence of its activation or inhibition in streptozotocin (STZ)-induced diabetic rat heart mitochondria. If confirmed, it could be a novel mechanism for regulation of long-chain fatty acid oxidation (FAO) in mitochondria. To obtain evidence of its existence, we tested whether heart mitochondria presented with palmitoyl-carnitine can generate and export palmitate. We found that intact mitochondria indeed generate and export palmitate. We have also found that the rates of these processes are markedly higher in STZ-diabetic rat heart mitochondria, in which palmitoyl-carnitine oxidation is also increased. Since mitochondrial thioesterase-1 (MTE-1) hydrolyzes acyl-CoA to CoA-SH + free fatty acid, and uncoupling protein-3 (UCP-3), reconstituted in liposomes, transports free fatty acids, we examined whether these proteins are also increased in STZ-diabetic rat heart mitochondria. We found that both of these proteins are indeed increased. Gene expression profile analysis revealed striking expression of mitochondrial long-chain fatty acid transport and oxidation genes, accompanying overexpression of MTE-1 and UCP-3 in STZ-diabetic rat hearts. Our findings provide the first direct evidence for the existence of a long-chain free fatty acid generation and export system in mitochondria and its activation in STZ-diabetic rat hearts in which FAO is enhanced. We suggest that its activation may facilitate, and inhibition may limit, enhancement of FAO. PMID:16855217

  5. Beta-oxidation of very-long-chain fatty acids and their coenzyme A derivatives by human skin fibroblasts.

    PubMed

    Singh, H; Derwas, N; Poulos, A

    1987-05-01

    The beta-oxidation of lignoceric acid (C24:0), hexacosanoic acid (C26:0), and their coenzyme A derivatives was investigated in human skin fibroblast homogenates. The cofactor requirements for oxidation of lignoceric acid and hexacosanoic acid were identical but were different from their coenzyme A derivatives. For example, lignoceric acid and hexacosanoic acid oxidation was strictly ATP dependent whereas the oxidation of the corresponding coenzyme A derivatives was ATP independent. Also the rate of oxidation of coenzyme A derivatives of lignoceric acid or hexacosanoic acid was much higher compared to the free fatty acids. In patients with Zellweger's syndrome, X-linked adrenoleukodystrophy and infantile Refsum's disease, the beta-oxidation of lignoceric and hexacosanoic acids was defective whereas the oxidation of their corresponding coenzyme A derivatives was nearly normal. The results presented in this communication suggest strongly that the beta-oxidation of very-long-chain fatty acids occurs exclusively in peroxisomes. However, the coenzyme A derivatives of very-long-chain fatty acids can be oxidized in mitochondria as well as in peroxisomes. The inability of the mitochondrial system to oxidize free fatty acids may be due to its inability to convert them to their corresponding coenzyme A derivatives. Our results suggest that a specific very-long-chain fatty acyl CoA synthetase may be required for the activation of the free fatty acids and that this synthetase may be deficient in patients with Zellweger's syndrome and possibly X-linked adrenoleukodystrophy, as well. The results presented suggest that substrate specificity and the subcellular localization of the synthetase may regulate the beta-oxidation of very-long-chain fatty acids in the cell. PMID:2437859

  6. Intakes of long-chain n-3 polyunsaturated fatty acids and fish in relation to measurements of subclinical atherosclerosis

    PubMed Central

    He, Ka; Liu, Kiang; Daviglus, Martha L.; Mayer-Davis, Elisabeth; Jenny, Nancy Swords; Jiang, Rui; Ouyang, Pamela; Steffen, Lyn M.; Siscovick, David; Wu, Colin; Barr, R. Graham; Tsai, Michael; Burke, Gregory L.

    2014-01-01

    Background Data on the relations of different types of fish meals and long-chain n-3 polyunsaturated fatty acids (n-3 PUFAs) with measures of atherosclerosis are sparse. Objective We examined intakes of long-chain n-3 PUFAs and fish in relation to clinical measures of subclinical atherosclerosis. Design A cross-sectional study was conducted in 5,488 multiethnic adults aged 45–84 years and free of clinical cardiovascular disease. Diet was assessed using self-administered food frequency questionnaires. Subclinical atherosclerosis was determined by common carotid intima-media thickness (cCIMT, >80th percentile), internal CIMT (iCIMT, >80th percentile), coronary artery calcium score (CAC, >0) or ankle-brachial index (ABI, <0.90), respectively. Results After adjustment for potential confounders, intakes of long-chain n-3 PUFAs and non-fried (broiled, steamed, baked or raw) fish were inversely related to subclinical atherosclerosis determined by cCIMT but not iCIMT, CAC or ABI. The multivariable odds ratio comparing the highest to the lowest quartile of dietary exposures in relation to subclinical atherosclerosis determined by cCIMT was 0.69 (95% CI: 0.55, 0.86; p for trend<0.01) for n-3 PUFA intake, 0.80 (95% CI: 0.64, 1.01; p=0.054) for non-fried fish and 0.90 (95% CI: 0.73, 1.10; p=0.33) for fried fish consumption. Conclusions This study indicates that dietary intake of long-chain n-3 PUFAs or non-fried fish is associated with lower prevalence of subclinical atherosclerosis classified by cCIMT although significant changes in iCIMT, CAC and ABI were not observed. Our findings also suggest that the association of fish and atherosclerosis may vary depending on the type of fish meal consumed and the measures of atherosclerosis. PMID:18842801

  7. Structure and Mechanism of an Arabidopsis Medium/Long-Chain-Length Prenyl Pyrophosphate Synthase1[W][OA

    PubMed Central

    Hsieh, Fu-Lien; Chang, Tao-Hsin; Ko, Tzu-Ping; Wang, Andrew H.-J.

    2011-01-01

    Prenyltransferases (PTSs) are involved in the biosynthesis of terpenes with diverse functions. Here, a novel PTS from Arabidopsis (Arabidopsis thaliana) is identified as a trans-type polyprenyl pyrophosphate synthase (AtPPPS), which forms a trans-double bond during each homoallylic substrate condensation, rather than a homomeric C10-geranyl pyrophosphate synthase as originally proposed. Biochemical and genetic complementation analyses indicate that AtPPPS synthesizes C25 to C45 medium/long-chain products. Its close relationship to other long-chain PTSs is also uncovered by phylogenetic analysis. A mutant of contiguous surface polar residues was produced by replacing four charged surface amino acids with alanines to facilitate the crystallization of the enzyme. The crystal structures of AtPPPS determined here in apo and ligand-bound forms further reveal an active-site cavity sufficient to accommodate the medium/long-chain products. The two monomers in each dimer adopt different conformations at the entrance of the active site depending on the binding of substrates. Taken together, these results suggest that AtPPPS is endowed with a unique functionality among the known PTSs. PMID:21220764

  8. Crystallization of the C-terminal domain of the mouse brain cytosolic long-chain acyl-CoA thioesterase

    SciTech Connect

    Serek, Robert; Forwood, Jade K.; Hume, David A.; Martin, Jennifer L.; Kobe, Bostjan

    2006-02-01

    The C-terminal domain of the mouse long-chain acyl-CoA thioesterase has been expressed in bacteria and crystallized by vapour diffusion. The crystals diffract to 2.4 Å resolution. The mammalian long-chain acyl-CoA thioesterase, the enzyme that catalyses the hydrolysis of acyl-CoAs to free fatty acids, contains two fused 4HBT (4-hydroxybenzoyl-CoA thioesterase) motifs. The C-terminal domain of the mouse long-chain acyl-CoA thioesterase (Acot7) has been expressed in bacteria and crystallized. The crystals were obtained by vapour diffusion using PEG 2000 MME as precipitant at pH 7.0 and 290 K. The crystals have the symmetry of space group R32 (unit-cell parameters a = b = 136.83, c = 99.82 Å, γ = 120°). Two molecules are expected in the asymmetric unit. The crystals diffract to 2.4 Å resolution using the laboratory X-ray source and are suitable for crystal structure determination.

  9. The IWA Anaerobic Digestion Model No 1 (ADM1).

    PubMed

    Batstone, D J; Keller, J; Angelidaki, I; Kalyuzhnyi, S V; Pavlostathis, S G; Rozzi, A; Sanders, W T M; Siegrist, H; Vavilin, V A

    2002-01-01

    The IWA Anaerobic Digestion Modelling Task Group was established in 1997 at the 8th World Congress on Anaerobic Digestion (Sendai, Japan) with the goal of developing a generalised anaerobic digestion model. The structured model includes multiple steps describing biochemical as well as physicochemical processes. The biochemical steps include disintegration from homogeneous particulates to carbohydrates, proteins and lipids; extracellular hydrolysis of these particulate substrates to sugars, amino acids, and long chain fatty acids (LCFA), respectively; acidogenesis from sugars and amino acids to volatile fatty acids (VFAs) and hydrogen; acetogenesis of LCFA and VFAs to acetate; and separate methanogenesis steps from acetate and hydrogen/CO2. The physico-chemical equations describe ion association and dissociation, and gas-liquid transfer. Implemented as a differential and algebraic equation (DAE) set, there are 26 dynamic state concentration variables, and 8 implicit algebraic variables per reactor vessel or element. Implemented as differential equations (DE) only, there are 32 dynamic concentration state variables. PMID:12188579

  10. Anaerobic sealing

    SciTech Connect

    Hayre, J.

    1986-05-01

    Anaerobic sealants offer an alternative to conventional methods of joint repair on mains operating at low and medium pressures. The method does not require highly skilled personnel who are diligent in ensuring that the necessary standards of preparation and seal application are achieved. British Gas' experience has shown that lead joints that do not contain yarn or where the yarn has deteriorated are difficult to seal. The evidence so far indicates that yarn is important in ensuring that the low viscosity sealant rapidly wicks around the joint during the injection operation. It is obvious that more research and development is needed in this field, but anaerobic sealing of leaking joints in an effective, innovative method of joint repair.

  11. Functional genomic study of the environmentally important Desulfovibrio /Methanococcus syntrophic co-culture.

    NASA Astrophysics Data System (ADS)

    Mukhopadhyay, A.

    2008-12-01

    The use of microbe-oriented bioremediation for ameliorating extensive environmental pollution has fostered fundamental and applied studies of environmentally relevant microorganisms such as Desulfovibrio vulgaris, Shewanella oneidensis and Geobacter metallireducens.. Concurrently, there has been an increasing appreciation that the physiology of these organisms in pure culture is not necessarily representative of its activities in the environment. To enable a better understanding of microbial physiology under more environmentally relevant conditions, the syntrophic growth between the sulfate reducing bacterium, D. vulgaris and the hydrogenotrophic methanogen, Methanococcus maripaludis serves as an ideal system for laboratory studies. Cell wide analyses using transcript, proteomics and metabolite analysis have been widely used to understand cellular activity at a molecular level. Using D. vulgaris and M. maripaludis arrays, and the iTRAQ proteomics method, we studied the physiology of the D. vulgaris / M. maripaludis syntrophic co- cultures. The results from this study allowed us to identify differences in cellular response in mono-culture vs. co-culture growth for both D. vulgaris and M. maripaludis.

  12. Quantification of syntrophic fatty acid-{beta}-oxidizing bacteria in a mesophilic biogas reactor by oligonucleotide probe hybridization

    SciTech Connect

    Hansen, K.H.; Ahring, B.K.; Raskin, L.

    1999-11-01

    Small-subunit rRNA sequences were obtained for two saturated fatty acid-{beta}-oxidizing syntrophic bacteria, Syntrophomonas sapovorans and Syntrophomonas wolfei LYB, and sequence analysis confirmed their classification as members of the family Syntrophomonadaceae. S.wolfei LYB was closely related to S.wolfei subsp. solfei, but S. sapovorans did not cluster with the other members of the genus Syntrophomonas. Five oligonucleotide probes targeting the small-subunit rRNA of different groups within the family Syntrophomonadaceae, which contains all currently known saturated fatty acid-{beta}-oxidizing syntrophic bacteria, were developed and characterized. The probes were designed to be specific at the family, genus, and species levels and were characterized by temperature-of-dissociation and specificity studies. To demonstrate the usefulness of the probes for the detection and quantification of saturated fatty acid-{beta}-oxidizing syntrophic bacteria in methanogenic environments, the microbial community structure of a sample from a full-scale biogas plant was determined. Hybridization results with probes for syntrophic bacteria and methanogens were compared to specific methanogenic activities and microbial numbers determined with most-probable-number estimates. Most of the methanogenic rRNA was comprised of Methanomicrobiales rRNA, suggesting that members of this order served as the main hydrogen-utilizing microorganisms. Between 0.2 and 1% of the rRNA was attributed to the Syntrophomonadaceae, or which the majority was accounted for by the genus Syntrophomonas.

  13. Quantification of Syntrophic Fatty Acid-β-Oxidizing Bacteria in a Mesophilic Biogas Reactor by Oligonucleotide Probe Hybridization

    PubMed Central

    Hansen, Kaare H.; Ahring, Birgitte K.; Raskin, Lutgarde

    1999-01-01

    Small-subunit rRNA sequences were obtained for two saturated fatty acid-β-oxidizing syntrophic bacteria, Syntrophomonas sapovorans and Syntrophomonas wolfei LYB, and sequence analysis confirmed their classification as members of the family Syntrophomonadaceae. S. wolfei LYB was closely related to S. wolfei subsp. wolfei, but S. sapovorans did not cluster with the other members of the genus Syntrophomonas. Five oligonucleotide probes targeting the small-subunit rRNA of different groups within the family Syntrophomonadaceae, which contains all currently known saturated fatty acid-β-oxidizing syntrophic bacteria, were developed and characterized. The probes were designed to be specific at the family, genus, and species levels and were characterized by temperature-of-dissociation and specificity studies. To demonstrate the usefulness of the probes for the detection and quantification of saturated fatty acid-β-oxidizing syntrophic bacteria in methanogenic environments, the microbial community structure of a sample from a full-scale biogas plant was determined. Hybridization results with probes for syntrophic bacteria and methanogens were compared to specific methanogenic activities and microbial numbers determined with most-probable-number estimates. Most of the methanogenic rRNA was comprised of Methanomicrobiales rRNA, suggesting that members of this order served as the main hydrogen-utilizing microorganisms. Between 0.2 and 1% of the rRNA was attributed to the Syntrophomonadaceae, of which the majority was accounted for by the genus Syntrophomonas. PMID:10543784

  14. Global transcriptomics analysis of the Desulfovibrio vulgaris change from syntrophic growth with Methanosarcina barkeri to sulfidogenic metabolism

    SciTech Connect

    Plugge, Caroline M.; Scholten, Johannes C.; Culley, David E.; Nie, Lei; Brockman, Fred J.; Zhang, Weiwen

    2010-09-01

    Abstract Desulfovibrio vulgaris is a metabolically flexible microorganism. It can use sulfate as electron acceptor to catabolize a variety of substrates, or in the absence of sulfate can utilize organic acids and alcohols by forming a syntrophic association with hydrogen scavenging partner to relieve inhibition by hydrogen. These alternativemetabolic types increase the chance of survival for D. vulgaris in environments where one of the potential external electron acceptors becomes depleted. In this work, whole-genome D. vulgaris microarrays were used to determine relative transcript levels as D. vulgaris shifted its metabolism from syntroph in a lactate-oxidizing dual-culture with Methanosarcina barkeri to a sulfidogenic metabolism. Syntrophic dual-cultures were grown in two independent chemostats and perturbation was introduced after six volume changes with the addition of sulfate. The results showed that 132 genes were differentially expressed in D. vulgaris 2 hours after addition of sulfate. Functional analyses suggested that genes involved in cell envelope and energy metabolism were the most regulated when comparing syntrophic and sulfidogenic metabolism. Up-regulation was observed for genes encoding ATPase and the membrane-integrated energy conserving hydrogenase (Ech) when cells shifted to a sulfidogenic metabolism. A five-gene cluster encoding several lipo- and membrane-bound proteins was down-regulated when cells were shifted to a sulfidogenic metabolism. Interestingly, this gene cluster has orthologs found only in another syntrophic bacterium Syntrophobacter fumaroxidans and four recently sequenced Desulfovibrio strains. This study also identified several novel c-type cytochrome encoding genes which may be involved in the sulfidogenic metabolism.

  15. PREECLAMPSIA IS ASSOCIATED WITH COMPROMISED MATERNAL SYNTHESIS OF LONG CHAIN POLYUNSATURATED FATTY ACIDS LEADING TO OFFSPRING DEFICIENCY

    PubMed Central

    Mackay, Vanessa A; Huda, Shahzya S; Stewart, Frances M; Tham, Kahmeng; McKenna, Louise A; Martin, Iain; Jordan, Fiona; Brown, E Ann; Hodson, Leanne; Greer, Ian A; Meyer, Barbara J; Freeman, Dilys J

    2013-01-01

    Obesity and excessive lipolysis are implicated in preeclampsia. Intrauterine growth restriction is associated with low maternal body mass index and decreased lipolysis. Our aim was to assess how maternal and offspring fatty acid metabolism is altered in mothers in the third trimester of pregnancy with preeclampsia (n=62) or intrauterine growth restriction (n=23) compared to healthy pregnancies (n=164). Markers of lipid metabolism and erythrocyte fatty acid concentrations were measured. Maternal adipose tissue fatty acid composition and mRNA expression of adipose tissue fatty acid metabolizing enzymes and placental fatty acid transporters were compared. Mothers with preeclampsia had higher plasma triglyceride (21%, p<0.001) and non-esterified fatty acid (50%, p<0.001) concentrations than Controls. Concentrations of major n-6 and n-3 long chain polyunsaturated fatty acids in erythrocytes were 23-60% lower (all p<0.005) in preeclampsia and intrauterine growth restriction mothers and offspring compared to Controls. Subcutaneous adipose tissue Δ-5 and Δ-6 desaturase and very long chain fatty acid elongase mRNA expression was lower in preeclampsia than Controls [Control 3.38(2.96) vs preeclampsia 1.83(1.91), p=0.030; 3.33(2.25) vs 1.03(0.96), p<0.001; 0.40 (0.81) vs 0.00 (0.00), p=0.038 (square root) expression relative to control gene respectively]. Low maternal and fetal long chain polyunsaturated fatty acid concentrations in preeclampsia may be the result of decreased maternal synthesis. PMID:22949531

  16. Anti-inflammatory coumarins with short- and long-chain hydrophobic groups from roots of Angelica dahurica cv. Hangbaizhi.

    PubMed

    Wei, Wei; Wu, Xiu-Wen; Deng, Gai-Gai; Yang, Xiu-Wei

    2016-03-01

    The (1)H NMR-guided fractionation of a cyclohexane soluble portion of the 75% ethanolic extract of the roots of Angelica dahurica cv. Hangbaizhi led to the isolation of two coumarins, namely, 5-(3"-hydroxy-3"-methylbutyl)-8-hydroxyfuranocoumarin, and isobyakangelicin hydrate-3"-ethyl ether, and ten coumarins with short- or long-chain hydrophobic groups, namely, andafocoumarins A-J. Their structures were elucidated by extensive spectroscopic analyses. The absolute configurations of the C-2" secondary alcohols in ten of these compounds were deduced via the circular dichroism data of the in situ formed [Rh2(OCOCF3)4] complex, and oxidation reactions were utilized to determine location of the double bonds in the lipid chain of andafocoumarins H and I, respectively. The long-chain hydrophobic group of andafocoumarin J was determined by the method of chemical degradation and GC-MS analysis. It was the first time that coumarins with short- or long-chain hydrophobic groups in this plant had been comprehensively investigated. All isolates were assayed for their inhibitory effect against nitric oxide (NO) production in a lipopolysaccharide (LPS)-activated RAW264.7 macrophage cell line, among which andafocoumarins A and B exhibited a potent inhibition on LPS-activated NO production with IC50 values of 19.7 and 13.9 μM, respectively, indicating their stronger inhibitory activity than l-N(6)-(1-iminoethyl)-lysine (IC50=23.7 μM), a selective inhibitor of inducible nitric oxide synthase. PMID:26775737

  17. Identification of Novel Genes Involved in Long-Chain n-Alkane Degradation by Acinetobacter sp. Strain DSM 17874▿

    PubMed Central

    Throne-Holst, Mimmi; Wentzel, Alexander; Ellingsen, Trond E.; Kotlar, Hans-Kristian; Zotchev, Sergey B.

    2007-01-01

    Acinetobacter sp. strain DSM 17874 is capable of utilizing n-alkanes with chain lengths ranging from that of decane (C10H22) to that of tetracontane (C40H82) as a sole carbon source. Two genes encoding AlkB-type alkane hydroxylase homologues, designated alkMa and alkMb, have been shown to be involved in the degradation of n-alkanes with chain lengths of from 10 to 20 C atoms in this strain. Here, we describe a novel high-throughput screening method and the screening of a transposon mutant library to identify genes involved in the degradation of n-alkanes with C chain lengths longer than 20, which are solid at 30°C, the optimal growth temperature for Acinetobacter sp. strain DSM 17874. A library consisting of approximately 6,800 Acinetobacter sp. strain DSM 17874 transposon mutants was constructed and screened for mutants unable to grow on dotriacontane (C32H66) while simultaneously showing wild-type growth characteristics on shorter-chain n-alkanes. For 23 such mutants isolated, the genes inactivated by transposon insertion were identified. Targeted inactivation and complementation studies of one of these genes, designated almA and encoding a putative flavin-binding monooxygenase, confirmed its involvement in the strain's metabolism of long-chain n-alkanes. To our knowledge, almA represents the first cloned gene shown to be involved in the bacterial degradation of long-chain n-alkanes of 32 C's and longer. Genes encoding AlmA homologues were also identified in other long-chain n-alkane-degrading Acinetobacter strains. PMID:17400787

  18. Very Long-Chain Acyl-CoA Synthetase 3: Overexpression and Growth Dependence in Lung Cancer

    PubMed Central

    Pei, Zhengtong; Fraisl, Peter; Shi, Xiaohai; Gabrielson, Edward; Forss-Petter, Sonja; Berger, Johannes; Watkins, Paul A.

    2013-01-01

    Lung cancer is the leading cause of cancer deaths worldwide. In the United States, only one in six lung cancer patients survives five years after diagnosis. These statistics may improve if new therapeutic targets are identified. We previously reported that an enzyme of fatty acid metabolism, very long-chain acyl-CoA synthetase 3 (ACSVL3), is overexpressed in malignant glioma, and that depleting glioblastoma cells of ACSVL3 diminishes their malignant properties. To determine whether ACSVL3 expression was also increased in lung cancer, we studied tumor histologic sections and lung cancer cell lines. Immunohistochemical analysis of normal human lung showed moderate ACSVL3 expression only in bronchial epithelial cells. In contrast, all of 69 different lung tumors tested, including adeno-, squamous cell, large cell, and small cell carcinomas, had robustly elevated ACSVL3 levels. Western blot analysis of lung cancer cell lines derived from these tumor types also had significantly increased ACSVL3 protein compared to normal bronchial epithelial cells. Decreasing the growth rate of lung cancer cell lines did not change ACSVL3 expression. However, knocking down ACSVL3 expression by RNA interference reduced cell growth rates in culture by 65–76%, and the ability of tumor cells to form colonies in soft agar suspension by 65–80%. We also conducted studies to gain a better understanding of the biochemical properties of human ACSVL3. ACSVL3 mRNA was detected in many human tissues, but the expression pattern differed somewhat from that of the mouse. The enzyme activated long- and very long-chain saturated fatty acid substrates, as well as long-chain mono- and polyunsaturated fatty acids to their respective coenzyme A derivatives. Endogenous human ACSVL3 protein was found in a punctate subcellular compartment that partially colocalized with mitochondria as determined by immunofluorescence microscopy and subcellular fractionation. From these studies, we conclude that ACSVL3 is

  19. Rheological properties of long-chain branched chlorinated poly(isobutylene-co-isoprene)-graft-polybutadiene terpolymers (CIIR-g-BR)

    NASA Astrophysics Data System (ADS)

    Sendorek, Jerzy (George)

    Anionically polymerized "living" polybutadiene (BR) was grafted onto chlorinated poly(isobutylene-co-isoprene) (CIIR) to form a series of elastomeric graft copolymers (CIIR-g-BR) of comb-type, long-chain branching structure (LCB) with systematically varying length and number of branches. A comprehensive program of analytical characterization of the structure and morphology of these materials using SEC/DRI-DV, NMR, FT-IR, DSC, TGA, TEM and other techniques, was designed to determine all relevant structural variables and parameters, as well as to exclude the presence of the potential compositional interferences (gel, residual solvent, unattached branch parent polymer, etc.) for intended correlations between branching structure and rheological properties. The principal branching characteristics of comb-like long-chain branched structures were derived from the stoichiometry of the grafting reaction, confirmed by compositional analysis using a combination of NMR/FT-IR/SEC and supplemented by SEC characterization of the parent linear polymers constituting the backbone (CIIR) and the branch of the graft (BR), respectively. Linear viscoelastic properties of these materials were determined by a Rheometrics Mechanical Spectrometer (RMS-800) using small amplitude, dynamic (sinusoidal oscillatory) shear. These measurements were supplemented by Rubber Process Analyzer (RPA 2000sp{TM}) testing in a comparable range of strain amplitudes, frequencies and temperatures. Stress relaxation experiments, following small amplitude step-strain in shear, complemented the dynamic mechanical measurement. Non-linear viscoelastic properties in shear were investigated in a series of isothermal strain and frequency sweeps using large strain (up to 800%) oscillations (RPA 2000), and by stress following a large-amplitude (˜75%) step shear strain, using the Dynamic Stress Relaxometer (DSR). An insight into the morphology of the grafts by means of the TEM and DSC has been compared to the results of

  20. Organosulfate Formation through the Heterogeneous Reaction of Sulfur Dioxide with Unsaturated Fatty Acids and Long-Chain Alkenes.

    PubMed

    Passananti, Monica; Kong, Lingdong; Shang, Jing; Dupart, Yoan; Perrier, Sébastien; Chen, Jianmin; Donaldson, D James; George, Christian

    2016-08-22

    The heterogeneous reaction between SO2 and unsaturated compounds results in the efficient production of organosulfates for several fatty acids and long-chain alkenes. The presence of an acid group, the physical state of the reactants (solid or liquid), the nature of the double bond (cis, trans, terminal), and the use of light irradiation all have an impact on the reaction rate. The reaction was investigated using different set-ups (coated flow tube, aerosol flow tube, and diffuse reflectance infrared Fourier transform cell). The reaction products were identified by high-resolution mass spectrometry and the impact of this reaction on organosulfate formation in the atmosphere is discussed. PMID:27458109

  1. Surface passivation of (100) GaSb using self-assembled monolayers of long-chain octadecanethiol

    NASA Astrophysics Data System (ADS)

    Papis-Polakowska, E.; Kaniewski, J.; Jurenczyk, J.; Jasik, A.; Czuba, K.; Walkiewicz, A. E.; Szade, J.

    2016-05-01

    The passivation of (100) GaSb surface was investigated by means of the long-chain octadecanethiol (ODT) self-assembled monolayer (SAM). The properties of ODT SAM on (100) GaSb were characterized by the atomic force microscopy using Kelvin probe force microscopy mode and X-ray photoelectron spectroscopy. The chemical treatment of 10mM ODT-C2H5OH has been applied to the passivation of a type-II superlattice InAs/GaSb photodetector. The electrical measurements indicate that the current density was reduced by one order of magnitude as compared to an unpassivated photodetector.

  2. Anaerobic 2-propanol degradation in anoxic paddy soil and the possible role of methanogens in its degradation.

    PubMed

    Tonouchi, Akio

    2004-08-01

    The anaerobic degradation of 2-propanol in anoxic paddy soil was studied with soil cultures and a 2-propanol-utilizing methanogen. Acetone was the first and the major intermediate involved in the methanogenic degradation of 2-propanol. Analyses with a methanogenesis inhibitor, bacteria antibiotics, and the addition of H2 to the gas phase revealed that 2-propanol oxidation to acetone directly occurred using 2-propanol-utilizing methanogens, but not with H2-producing syntrophic bacteria, for which the removal of acetone is required for complete 2-propanol oxidation. The 2-propanol-utilizing strain IIE1, which is phylogenetically closely related to Methanoculleus palmolei, was isolated from paddy soil, and the potential role of the strain in 2-propanol degradation was investigated. 2-Propanol is one of the representative fermentation intermediates in anaerobic environments. This is the first report on the anaerobic 2-propanol degradation process. PMID:15297909

  3. Use of PCR-DGGE based molecular methods to assessment of microbial diversity during anaerobic treatment of antibiotic combinations.

    PubMed

    Aydin, Sevcan; Shahi, Aiyoub; Ozbayram, E Gozde; Ince, Bahar; Ince, Orhan

    2015-09-01

    As it is currently often not know how anaerobic bioreactors, e.g. for biogas production, react if the substrate is contaminated by toxic compounds like antibiotics. This study evaluated how anaerobic sequencing batch reactors were affected by amendments of different antibiotics and stepwise increasing concentrations. The compositions of microbial community were determined in the seed sludge using 16S rRNA gene clone libraries and PCR-DGGE analyses were used for the detection of microbial community changes upon antibiotics additions. According to PCR-DGGE results, the syntrophic interaction of acetogens and methanogens is critical to the performance of the reactors. Failure to maintain the stability of these microorganisms resulted in a decrease in the performance and stability of the anaerobic reactors. Assessment of DGGE data is also useful for suggesting the potential to control ultimate microbial community structure, especially derived from Gram-negative bacteria, through bioaugmentation to successful for antibiotic biodegradation. PMID:26101963

  4. Microbial Ecology of Anaerobic Digesters: The Key Players of Anaerobiosis

    PubMed Central

    Ali Shah, Fayyaz; Mahmood, Qaisar; Maroof Shah, Mohammad; Pervez, Arshid; Ahmad Asad, Saeed

    2014-01-01

    Anaerobic digestion is the method of wastes treatment aimed at a reduction of their hazardous effects on the biosphere. The mutualistic behavior of various anaerobic microorganisms results in the decomposition of complex organic substances into simple, chemically stabilized compounds, mainly methane and CO2. The conversions of complex organic compounds to CH4 and CO2 are possible due to the cooperation of four different groups of microorganisms, that is, fermentative, syntrophic, acetogenic, and methanogenic bacteria. Microbes adopt various pathways to evade from the unfavorable conditions in the anaerobic digester like competition between sulfate reducing bacteria (SRB) and methane forming bacteria for the same substrate. Methanosarcina are able to use both acetoclastic and hydrogenotrophic pathways for methane production. This review highlights the cellulosic microorganisms, structure of cellulose, inoculum to substrate ratio, and source of inoculum and its effect on methanogenesis. The molecular techniques such as DGGE (denaturing gradient gel electrophoresis) utilized for dynamic changes in microbial communities and FISH (fluorescent in situ hybridization) that deal with taxonomy and interaction and distribution of tropic groups used are also discussed. PMID:24701142

  5. Structures of microbial communities found in anaerobic batch runs that produce methane from propionic acid--Seeded from full-scale anaerobic digesters above a certain threshold.

    PubMed

    Kim, Woong; Shin, Seung Gu; Han, Gyuseong; Cho, Kyungjin; Hwang, Seokhwan

    2015-11-20

    The volatile fatty acid propionate inhibits anaerobic digestion during organic waste treatments. To examine potential microbial interactions that accelerate propionate oxidation, anaerobic digestion systems seeded with various types of anaerobic sludge were analyzed. Seed samples were collected from 10 different full-scale anaerobic reactors in South Korea. Propionate oxidation was estimated as the methane production rate per gram of propionate used per day. Two domestic sewage sludge showed the highest methane production rate values, 109.1 ± 4.2 and 74.5 ± 8.6 mL CH4/(g propionate ∙ d). A food waste recycling wastewater source exhibited the lowest methane production rate, 33.2 ± 2.6 mL CH4/(g propionate ∙ d). To investigate how the microbial community structure affected propionate oxidation, qualitative molecular analyses were carried out using denaturing gradient gel electrophoresis. Methanosaeta concilii, an aceticlastic methanogen, was detected in most batch runs. Smithella propionica, a unique propionate oxidizer and simultaneous producer of acetate, was found in domestic sewage sludge sources showing the highest methane production rate; in contrast, Desulfobulbus rhabdoformis, a sulfate reducer coupled with the consumption of acetate to be used as a precursor of methane, was observed in food waste recycling wastewater sludge source showing the lowest methane production rate. Thus, we propose that S. propionica, a syntrophic acetate producer using propionate, might cooperate with aceticlastic methanogens for high methane production during anaerobic digestion that included propionate. PMID:26450560

  6. Effect of community structure on the kinetics of anaerobic degradation of aromatic compounds. Progress report, March 1989--June 1991

    SciTech Connect

    McInerney, M.J.

    1991-06-01

    The physiology of fatty acid metabolism and the kinetics of benzoate degradation by anaerobic syntrophic bacteria were studied. We have shown that: a threshold for benzoate degradation by a syntrophic coculture of Syntrophus buswellii and Desulfovibrio strain G11 exists and the value of the threshold depends on the amount of benzoate and acetate suggesting a thermodynamic limitation. Syntrophomonas wolfei has the enzymatic ability to produce formate and that low levels of formate are made during growth in pure culture with crotonate or in coculture with butyrate. However, the high specific activities of hydrogenase compared to formate dehydrogenase indicate that hydrogen rather than formate is the intermediate involved in the interspecies transfer of reducing equivalents. We have isolated Syntrophus buswellii and a novel anaerobic bacteria that catalyzes an aryl-ether cleavage reaction using crotonate as the energy source. Several novel obligately halophilic anaerobes from hypersaline oil reservoir brines were isolated and characterized. Two of these degraded pyrogallate with the production of acetate. We have shown that S. wolfei synthesizes poly-{beta}hydroxyalkanoate (PHA) by two routes, directly from a {beta}-oxidation intermediate without cleaving a C-C bond and by the condensation of two acetyl-CoA molecules. The formation of D-3-hydroxyacyl-CoA needed for PHA synthesis occurs by the activity of a acetoacetyl-CoA reductase rather than a enoyl-CoA hydratase. The genes for PHA synthesis in S. wolfei have been cloned into Escherichia coli.

  7. Long-chain polyunsaturated fatty acid biosynthesis in chordates: Insights into the evolution of Fads and Elovl gene repertoire.

    PubMed

    Castro, L Filipe C; Tocher, Douglas R; Monroig, Oscar

    2016-04-01

    Long-chain polyunsaturated fatty acids (LC-PUFA) are major components of complex lipid molecules and are also involved in numerous critical biological processes. Studies conducted mainly in vertebrates have demonstrated that LC-PUFA can be biosynthesized through the concerted action of two sets of enzymes, namely fatty acyl desaturases (Fads) and elongation of very long-chain fatty acid (Elovl) proteins. While LC-PUFA research is a thriving field, mainly focused on human health, an integrated view regarding the evolution of LC-PUFA biosynthetic genetic machinery in chordates is yet to be produced. Particularly important is to understand whether lineage specific life history trajectories, as well as major biological transitions, or particular genomic processes such as genome duplications have impacted the evolution of LC-PUFA biosynthetic pathways. Here we review the gene repertoire of Fads and Elovl in chordate genomes and the diversity of substrate specificities acquired during evolution. We take advantage of the magnitude of genomic and functional data to show that combination duplication processes and functional plasticity have generated a wide diversity of physiological capacities in extant lineages. A clear evolutionary framework is provided, which will be instrumental for the full clarification of functional capacities between the various vertebrate groups. PMID:26769304

  8. Intake levels of dietary long-chain PUFAs modify the association between genetic variation in FADS and LDL-C.

    PubMed

    Hellstrand, S; Sonestedt, E; Ericson, U; Gullberg, B; Wirfält, E; Hedblad, B; Orho-Melander, M

    2012-06-01

    Polymorphisms of the FA desaturase (FADS) gene cluster have been associated with LDL, HDL, and triglyceride concentrations. Because FADS converts α-linolenic acid (ALA) and linoleic acid into PUFAs, we investigated the interaction between different PUFA intakes and the FADS polymorphism rs174547 (T>C) on fasting blood lipid and lipoprotein concentrations. We included 4,635 individuals (60% females, 45-68 years) from the Swedish population-based Malmö Diet and Cancer cohort. Dietary intakes were assessed by a modified diet history method including 7-day registration of cooked meals. The C-allele of rs174547 was associated with lower LDL concentration (P = 0.03). We observed significant interaction between rs174547 and long-chain ω-3 PUFA intakes on LDL (P = 0.01); the C-allele was only associated with lower LDL among individuals in the lowest tertile of long-chain ω-3 PUFA intakes (P < 0.001). In addition, significant interaction was observed between rs174547 and the ratio of ALA and linoleic FA intakes on HDL (P = 0.03). However, no significant associations between the C-allele and HDL were detected within the intake tertiles of the ratio. Our findings suggest that dietary intake levels of different PUFAs modify the associated effect of genetic variation in FADS on LDL and HDL. PMID:22451038

  9. CYP4F2 affects phenotypic outcome in adrenoleukodystrophy by modulating the clearance of very long-chain fatty acids.

    PubMed

    van Engen, Catherine E; Ofman, Rob; Dijkstra, Inge M E; van Goethem, Tessa Jacobs; Verheij, Eveline; Varin, Jennifer; Vidaud, Michel; Wanders, Ronald J A; Aubourg, Patrick; Kemp, Stephan; Barbier, Mathieu

    2016-10-01

    X-linked adrenoleukodystrophy (ALD) is a severe neurodegenerative disorder caused by the accumulation of very long-chain fatty acids (VLCFA) due to mutations in the ABCD1 gene. The phenotypic spectrum ranges from a fatal cerebral demyelinating disease in childhood (cerebral ALD) to a progressive myelopathy without cerebral involvement in adulthood (adrenomyeloneuropathy). Because ABCD1 mutations have no predictive value with respect to clinical outcome a role for modifier genes was postulated. We report that the CYP4F2 polymorphism rs2108622 increases the risk of developing cerebral ALD in Caucasian patients. The rs2108622 polymorphism (c.1297G>A) results in an amino acid substitution valine for methionine at position 433 (p.V433M). Using cellular models of VLCFA accumulation, we show that p.V433M decreases the conversion of VLCFA into very long-chain dicarboxylic acids by ω-oxidation, a potential escape route for the deficient peroxisomal β-oxidation of VLCFA in ALD. Although p.V433M does not affect the catalytic activity of CYP4F2 it reduces CYP4F2 protein levels markedly. These findings open perspectives for therapeutic interventions in a disease with currently limited treatment options. PMID:27425035

  10. Substrate availability for long-chain base formation as a regulator of hepatic sphingolipid and cholesterol biosynthesis

    SciTech Connect

    Messmer, T.O.; Merrill, A.H. Jr.

    1986-03-05

    The de novo biosynthesis of the sphinganine and sphingosine backbones of sphingolipids was studied with isolated rat hepatocytes and established liver cell lines. The rate of incorporation of radiolabel from (/sup 14/C)-serine by intact cells was half maximal at 0.3 mM, which is similar to the K/sub m/ of the initial enzyme of this pathway and in vivo concentrations of this substrate. Long-chain base biosynthesis was stimulated by another precursor, palmitic acid, but other fatty acids were inhibitory. Hepatocytes isolated from fed and fasted rats had different rates of sphingolipid formation, which may also reflect the relative levels of palmitoyl-CoA. These results established that the availability of the precursors of long-chain base formation, serine and palmitic acid, is a major factor in the regulation of this pathway. Since sphingomyelin biosynthesis could be modified, its relationship to cholesterol metabolism was also examined. Both hepatocytes and cultured liver cells in high serine (0.6mM) had increased incorporation of (/sup 14/C)-acetate into cholesterol (13%, P < 0.05 and 50%, P < 0.01, respectively). These results indicate that sphingolipid and cholesterol biosynthesis are coordinately regulated, perhaps because these lipids are located in similar membranes and lipoproteins.

  11. Long-chain bases of sphingolipids are transported into cells via the acyl-CoA synthetases.

    PubMed

    Narita, Tomomi; Naganuma, Tatsuro; Sase, Yurie; Kihara, Akio

    2016-01-01

    Transport of dietary lipids into small-intestinal epithelial cells is pathologically and nutritionally important. However, lipid uptake remains an almost unexplored research area. Although we know that long-chain bases (LCBs), constituents of sphingolipids, can enter into cells efficiently, the molecular mechanism of LCB uptake is completely unclear. Here, we found that the yeast acyl-CoA synthetases (ACSs) Faa1 and Faa4 are redundantly involved in LCB uptake. In addition to fatty acid-activating activity, transporter activity toward long-chain fatty acids (LCFAs) has been suggested for ACSs. Both LCB and LCFA transports were largely impaired in faa1Δ faa4Δ cells. Furthermore, LCB and LCFA uptakes were mutually competitive. However, the energy dependency was different for their transports. Sodium azide/2-deoxy-D-glucose treatment inhibited import of LCFA but not that of LCB. Furthermore, the ATP-AMP motif mutation FAA1 S271A largely impaired the metabolic activity and LCFA uptake, while leaving LCB import unaffected. These results indicate that only LCFA transport requires ATP. Since ACSs do not metabolize LCBs as substrates, Faa1 and Faa4 are likely directly involved in LCB transport. Furthermore, we revealed that ACSs are also involved in LCB transport in mammalian cells. Thus, our findings provide strong support for the hypothesis that ACSs directly transport LCFAs. PMID:27136724

  12. Glucosylceramide having a novel tri-unsaturated long-chain base from the spermatozoa of the starfish, Asterias amurensis.

    PubMed

    Irie, A; Kubo, H; Hoshi, M

    1990-04-01

    Glucosylceramide (Glc beta 1-1Cer) was isolated from the spermatozoa of the starfish, Asterias amurensis. The long-chain bases of the glycolipid consisted of dihydroxy (d18:2, d18:3, d19:3, and d22:2), and trihydroxy (t22:1) types. Long-chain aldehydes derived from them were analyzed mainly by proton nuclear-magnetic resonance to determine the detailed structures. Two of the tri-unsaturated bases were identified as (4E,8E,10E)-2-amino-4,8,10-octadecatriene-1,3-di ol (d18:3) and (4E,8E,10E)-2-amino-9-methyl-4,8,10-octadecatriene+ ++-1,3-diol (d19:3), which is a novel base. Both d22:2 and t22:1 had a cis double bond at the C9 or C13 position. All fatty acids were 2-hydroxylated (C14-C25): Most of them were saturated and unbranched. About 10% was mono-unsaturated and unbranched (C22-C25), while saturated but branched (iso- and anteiso-types) C15-C18 acids were found as minor components. The main fatty acids, which summed up to more than 93% of the fatty acids in the glucosylceramide, were n-14h:0, n-15h:0, n-16h:0, n-17h:0, n-18h:0, and n-24h:1. PMID:2358431

  13. Identification of a Long-Chain Polyunsaturated Fatty Acid Acyl-Coenzyme A Synthetase from the Diatom Thalassiosira pseudonana1

    PubMed Central

    Tonon, Thierry; Qing, Renwei; Harvey, David; Li, Yi; Larson, Tony Robert; Graham, Ian Alexander

    2005-01-01

    The draft genome of the diatom Thalassiosira pseudonana was searched for DNA sequences showing homology with long-chain acyl-coenzyme A synthetases (LACSs), since the corresponding enzyme may play a key role in the accumulation of health-beneficial polyunsaturated fatty acids (PUFAs) in triacylglycerol. Among the candidate genes identified, an open reading frame named TplacsA was found to be full length and constitutively expressed during cell cultivation. The predicted amino acid sequence of the corresponding protein, TpLACSA, exhibited typical features of acyl-coenzyme A (acyl-CoA) synthetases involved in the activation of long-chain fatty acids. Feeding experiments carried out in yeast (Saccharomyces cerevisiae) transformed with the algal gene showed that TpLACSA was able to activate a number of PUFAs, including eicosapentaenoic acid and docosahexaenoic acid (DHA). Determination of acyl-CoA synthetase activities by direct measurement of acyl-CoAs produced in the presence of different PUFA substrates showed that TpLACSA was most active toward DHA. Heterologous expression also revealed that TplacsA transformants were able to incorporate more DHA in triacylglycerols than the control yeast. PMID:15821149

  14. Long-chain bases of sphingolipids are transported into cells via the acyl-CoA synthetases

    PubMed Central

    Narita, Tomomi; Naganuma, Tatsuro; Sase, Yurie; Kihara, Akio

    2016-01-01

    Transport of dietary lipids into small-intestinal epithelial cells is pathologically and nutritionally important. However, lipid uptake remains an almost unexplored research area. Although we know that long-chain bases (LCBs), constituents of sphingolipids, can enter into cells efficiently, the molecular mechanism of LCB uptake is completely unclear. Here, we found that the yeast acyl-CoA synthetases (ACSs) Faa1 and Faa4 are redundantly involved in LCB uptake. In addition to fatty acid-activating activity, transporter activity toward long-chain fatty acids (LCFAs) has been suggested for ACSs. Both LCB and LCFA transports were largely impaired in faa1Δ faa4Δ cells. Furthermore, LCB and LCFA uptakes were mutually competitive. However, the energy dependency was different for their transports. Sodium azide/2-deoxy-D-glucose treatment inhibited import of LCFA but not that of LCB. Furthermore, the ATP-AMP motif mutation FAA1 S271A largely impaired the metabolic activity and LCFA uptake, while leaving LCB import unaffected. These results indicate that only LCFA transport requires ATP. Since ACSs do not metabolize LCBs as substrates, Faa1 and Faa4 are likely directly involved in LCB transport. Furthermore, we revealed that ACSs are also involved in LCB transport in mammalian cells. Thus, our findings provide strong support for the hypothesis that ACSs directly transport LCFAs. PMID:27136724

  15. Long-chain acyl-CoA synthetase 4 modulates prostaglandin E2 release from human arterial smooth muscle cells

    PubMed Central

    Golej, Deidre L.; Askari, Bardia; Kramer, Farah; Barnhart, Shelley; Vivekanandan-Giri, Anuradha; Pennathur, Subramaniam; Bornfeldt, Karin E.

    2011-01-01

    Long-chain acyl-CoA synthetases (ACSLs) catalyze the thioesterification of long-chain FAs into their acyl-CoA derivatives. Purified ACSL4 is an arachidonic acid (20:4)-preferring ACSL isoform, and ACSL4 is therefore a probable regulator of lipid mediator production in intact cells. Eicosanoids play important roles in vascular homeostasis and disease, yet the role of ACSL4 in vascular cells is largely unknown. In the present study, the ACSL4 splice variant expressed in human arterial smooth muscle cells (SMCs) was identified as variant 1. To investigate the function of ACSL4 in SMCs, ACSL4 variant 1 was overexpressed, knocked-down by small interfering RNA, or its enzymatic activity acutely inhibited in these cells. Overexpression of ACSL4 resulted in a markedly increased synthesis of arachidonoyl-CoA, increased 20:4 incorporation into phosphatidylethanolamine, phosphatidylinositol, and triacylglycerol, and reduced cellular levels of unesterified 20:4. Accordingly, secretion of prostaglandin E2 (PGE2) was blunted in ACSL4-overexpressing SMCs compared with controls. Conversely, acute pharmacological inhibition of ACSL4 activity resulted in increased release of PGE2. However, long-term downregulation of ACSL4 resulted in markedly reduced PGE2 secretion. Thus, ACSL4 modulates PGE2 release from human SMCs. ACSL4 may regulate a number of processes dependent on the release of arachidonic acid-derived lipid mediators in the arterial wall. PMID:21242590

  16. Long-Chain Acyl CoA Synthetase 4A regulates Smad activity and dorsoventral patterning in the zebrafish embryo

    PubMed Central

    Miyares, Rosa Linda; Stein, Cornelia; Renisch, Björn; Anderson, Jennifer Lynn; Hammerschmidt, Matthias; Farber, Steven Arthur

    2013-01-01

    Summary Long-chain polyunsaturated fatty acids (LC-PUFA) and their metabolites are critical players in cell biology and embryonic development. Here we show that long-chain acyl CoA synthetase 4a (Acsl4a), an LC-PUFA activating enzyme, is essential for proper patterning of the zebrafish dorsoventral axis. Loss of Acsl4a results in dorsalized embryos due to attenuated Bmp signaling. We demonstrate that Acsl4a modulates the activity of Smad transcription factors, the downstream mediators of Bmp signaling. Acsl4a promotes the inhibition of p38 MAPK and the Akt-mediated inhibition of glycogen synthase kinase 3 (GSK3), critical inhibitors of Smad activity. Consequently, introduction of a constitutively active Akt can rescue the dorsalized phenotype of Acsl4a deficient embryos. Our results reveal a critical role for Acsl4a in modulating Bmp-Smad activity and provide a potential avenue for LC-PUFAs to influence a variety of developmental processes. PMID:24332754

  17. Modelling the effect of the antimicrobial tylosin on the performance of an anaerobic sequencing batch reactor.

    PubMed

    Shimada, T; Zilles, J L; Morgenroth, E; Raskin, L

    2008-01-01

    A laboratory-scale anaerobic sequencing batch reactor (ASBR) was fed a synthetic wastewater containing glucose to study the effects of the antimicrobial tylosin on treatment performance. Measurements of methane, volatile fatty acids, and COD concentrations suggested that the addition of 1.67 mg/L and 167 mg/l of tylosin to the synthetic wastewater inhibited propionate oxidizing syntrophic bacteria and aceticlastic methanogens. The latter is presumed to be an indirect effect. A modified version of the IWA Anaerobic Digestion Model No. 1 (ADM1) with extensions for microbial storage and hydrolysis of reserve carbohydrates, and tylosin liquid-solid mass transfer and inhibition adequately described the dynamic profiles observed in the ASBR. PMID:18547919

  18. Anaerobic Thermophiles

    PubMed Central

    Canganella, Francesco; Wiegel, Juergen

    2014-01-01

    The term “extremophile” was introduced to describe any organism capable of living and growing under extreme conditions. With the further development of studies on microbial ecology and taxonomy, a variety of “extreme” environments have been found and an increasing number of extremophiles are being described. Extremophiles have also been investigated as far as regarding the search for life on other planets and even evaluating the hypothesis that life on Earth originally came from space. The first extreme environments to be largely investigated were those characterized by elevated temperatures. The naturally “hot environments” on Earth range from solar heated surface soils and water with temperatures up to 65 °C, subterranean sites such as oil reserves and terrestrial geothermal with temperatures ranging from slightly above ambient to above 100 °C, to submarine hydrothermal systems with temperatures exceeding 300 °C. There are also human-made environments with elevated temperatures such as compost piles, slag heaps, industrial processes and water heaters. Thermophilic anaerobic microorganisms have been known for a long time, but scientists have often resisted the belief that some organisms do not only survive at high temperatures, but actually thrive under those hot conditions. They are perhaps one of the most interesting varieties of extremophilic organisms. These microorganisms can thrive at temperatures over 50 °C and, based on their optimal temperature, anaerobic thermophiles can be subdivided into three main groups: thermophiles with an optimal temperature between 50 °C and 64 °C and a maximum at 70 °C, extreme thermophiles with an optimal temperature between 65 °C and 80 °C, and finally hyperthermophiles with an optimal temperature above 80 °C and a maximum above 90 °C. The finding of novel extremely thermophilic and hyperthermophilic anaerobic bacteria in recent years, and the fact that a large fraction of them belong to the Archaea has

  19. Anaerobic thermophiles.

    PubMed

    Canganella, Francesco; Wiegel, Juergen

    2014-01-01

    The term "extremophile" was introduced to describe any organism capable of living and growing under extreme conditions. With the further development of studies on microbial ecology and taxonomy, a variety of "extreme" environments have been found and an increasing number of extremophiles are being described. Extremophiles have also been investigated as far as regarding the search for life on other planets and even evaluating the hypothesis that life on Earth originally came from space. The first extreme environments to be largely investigated were those characterized by elevated temperatures. The naturally "hot environments" on Earth range from solar heated surface soils and water with temperatures up to 65 °C, subterranean sites such as oil reserves and terrestrial geothermal with temperatures ranging from slightly above ambient to above 100 °C, to submarine hydrothermal systems with temperatures exceeding 300 °C. There are also human-made environments with elevated temperatures such as compost piles, slag heaps, industrial processes and water heaters. Thermophilic anaerobic microorganisms have been known for a long time, but scientists have often resisted the belief that some organisms do not only survive at high temperatures, but actually thrive under those hot conditions. They are perhaps one of the most interesting varieties of extremophilic organisms. These microorganisms can thrive at temperatures over 50 °C and, based on their optimal temperature, anaerobic thermophiles can be subdivided into three main groups: thermophiles with an optimal temperature between 50 °C and 64 °C and a maximum at 70 °C, extreme thermophiles with an optimal temperature between 65 °C and 80 °C, and finally hyperthermophiles with an optimal temperature above 80 °C and a maximum above 90 °C. The finding of novel extremely thermophilic and hyperthermophilic anaerobic bacteria in recent years, and the fact that a large fraction of them belong to the Archaea has definitely

  20. Competition and coexistence between a syntrophic consortium and a metabolic generalist, and its effect on productivity.

    PubMed

    Stump, Simon M; Klausmeier, Christopher A

    2016-09-01

    Syntrophic interactions, where species consume metabolites excreted by others, are common in microbial communities, and have uses in synthetic biology. Syntrophy is likely to arise when trade-offs favor an organism that specializes on particular metabolites, rather than all possible metabolites. Several trade-offs have been suggested; however, few models consider different trade-offs to test which are most consistent with observed patterns. Here, we develop a differential equation model to study competition between a syntrophic processing chain, where each microbe can perform one step in metabolizing an initial resource to a final state, and a metabolic generalist that can perform all metabolic functions. We also examine how competition affects the production of the final metabolic compound. We find that competitive outcomes can be predicted by a generalization of the R(⁎)-rule and relative nonlinearity. Therefore, the species that can persist at the lowest resource level is the competitive dominant in a constant environment, and species can coexist by partitioning variation in resources. We derive a simple rule for predicting production rates of the final metabolite, and show that competition may not maximize final metabolite production. We show that processing chains are inherently less efficient, because resources are lost during each step of the process. Our results also suggest which trade-offs are capable of explaining certain empirical observations. For example, processing chains appear to be more common in nutrient-rich environments; our model suggests that a specificity trade-off and an affinity-yield trade-off would not predict this, but a yield-maximum growth trade-off might. PMID:27320679

  1. The quantitative significance of Syntrophaceae and syntrophic partnerships in methanogenic degradation of crude oil alkanes

    PubMed Central

    Gray, N D; Sherry, A; Grant, R J; Rowan, A K; Hubert, C R J; Callbeck, C M; Aitken, C M; Jones, D M; Adams, J J; Larter, S R; Head, I M

    2011-01-01

    Libraries of 16S rRNA genes cloned from methanogenic oil degrading microcosms amended with North Sea crude oil and inoculated with estuarine sediment indicated that bacteria from the genera Smithella (Deltaproteobacteria, Syntrophaceace) and Marinobacter sp. (Gammaproteobacteria) were enriched during degradation. Growth yields and doubling times (36 days for both Smithella and Marinobacter) were determined using qPCR and quantitative data on alkanes, which were the predominant hydrocarbons degraded. The growth yield of the Smithella sp. [0.020 g(cell-C)/g(alkane-C)], assuming it utilized all alkanes removed was consistent with yields of bacteria that degrade hydrocarbons and other organic compounds in methanogenic consortia. Over 450 days of incubation predominance and exponential growth of Smithella was coincident with alkane removal and exponential accumulation of methane. This growth is consistent with Smithella's occurrence in near surface anoxic hydrocarbon degrading systems and their complete oxidation of crude oil alkanes to acetate and/or hydrogen in syntrophic partnership with methanogens in such systems. The calculated growth yield of the Marinobacter sp., assuming it grew on alkanes, was [0.0005 g(cell-C)/g(alkane-C)] suggesting that it played a minor role in alkane degradation. The dominant methanogens were hydrogenotrophs (Methanocalculus spp. from the Methanomicrobiales). Enrichment of hydrogen-oxidizing methanogens relative to acetoclastic methanogens was consistent with syntrophic acetate oxidation measured in methanogenic crude oil degrading enrichment cultures. qPCR of the Methanomicrobiales indicated growth characteristics consistent with measured rates of methane production and growth in partnership with Smithella. PMID:21914097

  2. The potential use of n-alkanes, long-chain alcohols and long-chain fatty acids as diet composition markers: indoor validation with sheep and herbage species from the rangeland of Inner Mongolia of China.

    PubMed

    Lin, L J; Zhu, X Y; Jiang, C; Luo, H L; Wang, H; Zhang, Y J; Hong, F Z

    2012-03-01

    To investigate the potential use of n-alkanes (alkanes), long-chain alcohols (alcohols) and long-chain fatty acids (acids) for estimating the diet composition of sheep, in a feeding trial. A total of 18 sheep were assigned randomly to three different diets (diet A, diet B and diet C) containing up to eight herbage species (Leymus chinensis, Leymus dasystachys, Elymus sibiricum, Chenopodium album, Puccinellia chinampoensis, Medicago sativa, Saussurea sinuata and Bromus inermis). Faecal recoveries of alkanes, alcohols and acids were determined, and diet compositions were estimated using different combinations of alkanes, alcohols and acids. The faecal concentrations of individual alkanes, alcohols and acids were corrected using the mean recovery of the dietary treatment that the respective animal belonged to (diet recovery), or the mean recovery across all dietary treatments (general recovery). In general, diets did not affect the faecal recovery values for alkanes, alcohols and acids, and no difference in accuracy was found between diet composition estimates based on dietary recovery and general recovery. The accuracy of diet composition estimates declined as the number of dietary components increased from four to eight herbage species (P < 0.001). Better (P < 0.05) estimates of diet composition were obtained with the combinations of two or three marker types instead of alkanes alone. Moreover, results showed that excluding minor diet components from the calculations decreased (P < 0.05) the accuracy of diet composition estimates, whereas including extra non-grazed herbage species did not reduce (P > 0.05) the quality of diet composition estimates. These results confirmed the usefulness of alkanes, alcohols and acids as markers for determining complex diet composition of sheep. However, a negative impact on the accuracy of diet composition estimates, caused by missing minor diet components from the calculation of diet composition, could happen when plant wax markers

  3. A 90 kyr upwelling record from the northwestern Indian Ocean using a novel long-chain diol index

    NASA Astrophysics Data System (ADS)

    Rampen, Sebastiaan W.; Schouten, Stefan; Koning, Erica; Brummer, Geert-Jan A.; Sinninghe Damsté, Jaap S.

    2008-11-01

    Presently, upwelling is of major importance for driving primary productivity in the Arabian Sea but its intensity in the past is not well constrained. Here we used long-chain 1,14-alkane diols, specific lipids of diatoms of the genus Proboscia, as new proxies to reconstruct upwelling conditions in the Arabian Sea. Variations in the seasonal lipid fluxes were determined using sediment traps in the Somalia upwelling system deployed 80 km off the coast on the Somali continental slope (NIOP 905, 10°45.444'N / 51°56.655'E) at 1265 m water depth, 268 m above the sea floor and 270 km off the coast in the deep Somali Basin south of Socotra (NIOP 915, 10°43.068'N / 53°34.422'E), at 3047 m depth, 1000 m above the sea floor. Highest fluxes of C 28 and C 30 1,14-diols (up to almost 600 µg m - 2 day - 1 ) were only observed during nutricline shoaling at the onset of the Southwest monsoon (SWM), prior to massive upwelling. By contrast, fluxes of C 30 1,15-diols, derived from as yet undefined biological sources, only increased marginally during the SWM and also during the Northeast monsoon (NEM), when, instead of upwelling, enhanced vertical mixing led to a second productivity pulse. Sediment core NIOP 905 taken at the continental slope site showed strong fluctuations in relative concentrations of long-chain 1,14- and 1,15-diols with time, which we quantified as the summed concentrations of C 28 and C 30 1,14-diols divided by the summed concentrations of C 28 and C 30 1,14-diols and C 30 1,15-diols. This diol index follows the same trend as other upwelling intensity records from the Arabian Sea that are based on sea surface temperature reconstructions, organic carbon content, barium/aluminium ratios, and abundance and stable isotope composition of specific foraminiferal species. The diol index was relatively high during the Holocene (ca. 0.7) but much lower during the Late Glacial Maximum (ca. 0.2). It was generally low during the last Glacial but elevated values were found

  4. Thermodynamic Interactions between Polystyrene and Long-Chain Poly(n-Alkyl Acrylates) Derived from Plant Oils.

    PubMed

    Wang, Shu; Robertson, Megan L

    2015-06-10

    Vegetable oils and their fatty acids are promising sources for the derivation of polymers. Long-chain poly(n-alkyl acrylates) and poly(n-alkyl methacrylates) are readily derived from fatty acids through conversion of the carboxylic acid end-group to an acrylate or methacrylate group. The resulting polymers contain long alkyl side-chains with around 10-22 carbon atoms. Regardless of the monomer source, the presence of alkyl side-chains in poly(n-alkyl acrylates) and poly(n-alkyl methacrylates) provides a convenient mechanism for tuning their physical properties. The development of structured multicomponent materials, including block copolymers and blends, containing poly(n-alkyl acrylates) and poly(n-alkyl methacrylates) requires knowledge of the thermodynamic interactions governing their self-assembly, typically described by the Flory-Huggins interaction parameter χ. We have investigated the χ parameter between polystyrene and long-chain poly(n-alkyl acrylate) homopolymers and copolymers: specifically we have included poly(stearyl acrylate), poly(lauryl acrylate), and their random copolymers. Lauryl and stearyl acrylate were chosen as model alkyl acrylates derived from vegetable oils and have alkyl side-chain lengths of 12 and 18 carbon atoms, respectively. Polystyrene is included in this study as a model petroleum-sourced polymer, which has wide applicability in commercially relevant multicomponent polymeric materials. Two independent methods were employed to measure the χ parameter: cloud point measurements on binary blends and characterization of the order-disorder transition of triblock copolymers, which were in relatively good agreement with one another. The χ parameter was found to be independent of the alkyl side-chain length (n) for large values of n (i.e., n > 10). This behavior is in stark contrast to the n-dependence of the χ parameter predicted from solubility parameter theory. Our study complements prior work investigating the interactions between

  5. Activation of Short and Long Chain Fatty Acid Sensing Machinery in the Ileum Lowers Glucose Production in Vivo.

    PubMed

    Zadeh-Tahmasebi, Melika; Duca, Frank A; Rasmussen, Brittany A; Bauer, Paige V; Côté, Clémence D; Filippi, Beatrice M; Lam, Tony K T

    2016-04-15

    Evidence continues to emerge detailing the myriad of ways the gut microbiota influences host energy homeostasis. Among the potential mechanisms, short chain fatty acids (SCFAs), the byproducts of microbial fermentation of dietary fibers, exhibit correlative beneficial metabolic effects in humans and rodents, including improvements in glucose homeostasis. The underlying mechanisms, however, remain elusive. We here report that one of the main bacterially produced SCFAs, propionate, activates ileal mucosal free fatty acid receptor 2 to trigger a negative feedback pathway to lower hepatic glucose production in healthy rats in vivo We further demonstrate that an ileal glucagon-like peptide-1 receptor-dependent neuronal network is necessary for ileal propionate and long chain fatty acid sensing to regulate glucose homeostasis. These findings highlight the potential to manipulate fatty acid sensing machinery in the ileum to regulate glucose homeostasis. PMID:26896795

  6. Multi-lamellar vesicle formation in a long-chain nonionic surfactant: C16E4/D2O system.

    PubMed

    Gentile, Luigi; Mortensen, Kell; Rossi, Cesare Oliviero; Olsson, Ulf; Ranieri, Giuseppe A

    2011-10-01

    The temperature dependent rheological and structural behavior of a long-chain C(16)E(4) (tetraethylene glycol monohexadecyl ether) surfactant in D(2)O has been studied within the regime of low shear range. In the absence of shear flow, the system forms a lamellar liquid crystalline phase at relatively high temperatures. The present paper reports on the shear-induced multi-lamellar vesicle (MLV) formation in C(16)E(4)/D(2)O at 40 wt.% of surfactant in the temperature range of 40-55 °C. The transition from planar lamellar structure to multi-lamellar vesicles has been investigated by time-resolved experiments combining rheology and nuclear magnetic resonance (rheo-NMR), rheo small-angle neutron scattering (rheo-SANS) and rheometry. The typical transient viscosity behavior of MLV formation has been discovered at low shear rate value of 0.5s(-1). PMID:21767850

  7. Metabolic engineering of Phaeodactylum tricornutum for the enhanced accumulation of omega-3 long chain polyunsaturated fatty acids☆

    PubMed Central

    Hamilton, Mary L.; Haslam, Richard P.; Napier, Johnathan A.; Sayanova, Olga

    2014-01-01

    We have engineered the diatom Phaeodactylum tricornutum to accumulate the high value omega-3 long chain polyunsaturated fatty acid docosahexaenoic acid (DHA). This was achieved by the generation of transgenic strains in which the Δ5-elongase from the picoalga Ostreococcus tauri was expressed to augment the endogenous fatty acid biosynthetic pathway. Expression of the heterologous elongase resulted in an eight-fold increase in docosahexaenoic acid content, representing a marked and valuable change in the fatty acid profile of this microalga. Importantly, DHA was shown to accumulate in triacylglycerols, with several novel triacylglycerol species being detected in the transgenic strains. In a second iteration, co-expression of an acyl-CoA-dependent Δ6-desaturase with the Δ5-elongase further increased DHA levels. Together, this demonstrates for the first time the potential of using iterative metabolic engineering to optimise omega-3 content in algae. PMID:24333273

  8. X-ray Scattering Studies of Long-Chain Alkanol Monolayers at the Water-Hexane Interface

    SciTech Connect

    Schlossman, Mark L.; Tikhonov, Aleksey M.

    2006-01-17

    X-ray reflectivity and interfacial tension measurements demonstrate that long-chain alkanol monolayers at the water-hexane interface exhibit a well defined chain disorder and partial hexane mixing into the monolayer, in contrast to alkanol monolayers at the water-vapor interface that consist of close-packed rigid rod molecules. At the water-hexane interface triacontanol molecules form a condensed phase with progressive disordering of the chain from the -CH{sub 2}OH to the -CH{sub 3} group. At this interface the density in the head-group region is 10 to 15% greater than bulk water, an effect not seen for the ordered monolayer at the water-vapor interface. Monolayers of shorter length alkanols (consisting of 20, 22, and 24 carbons) and variations with temperature are also discussed.

  9. TORC1 inhibits GSK3-mediated Elo2 phosphorylation to regulate very long chain fatty acid synthesis and autophagy.

    PubMed

    Zimmermann, Christine; Santos, Aline; Gable, Kenneth; Epstein, Sharon; Gururaj, Charulatha; Chymkowitch, Pierre; Pultz, Dennis; Rødkær, Steven V; Clay, Lorena; Bjørås, Magnar; Barral, Yves; Chang, Amy; Færgeman, Nils J; Dunn, Teresa M; Riezman, Howard; Enserink, Jorrit M

    2013-11-27

    Very long chain fatty acids (VLCFAs) are essential fatty acids with multiple functions, including ceramide synthesis. Although the components of the VLCFA biosynthetic machinery have been elucidated, how their activity is regulated to meet the cell's metabolic demand remains unknown. The goal of this study was to identify mechanisms that regulate the rate of VLCFA synthesis, and we discovered that the fatty acid elongase Elo2 is regulated by phosphorylation. Elo2 phosphorylation is induced upon inhibition of TORC1 and requires GSK3. Expression of nonphosphorylatable Elo2 profoundly alters the ceramide spectrum, reflecting aberrant VLCFA synthesis. Furthermore, VLCFA depletion results in constitutive activation of autophagy, which requires sphingoid base phosphorylation. This constitutive activation of autophagy diminishes cell survival, indicating that VLCFAs serve to dampen the amplitude of autophagy. Together, our data reveal a function for TORC1 and GSK3 in the regulation of VLCFA synthesis that has important implications for autophagy and cell homeostasis. PMID:24239358

  10. A computational search for lipases that can preferentially hydrolyze long-chain omega-3 fatty acids from fish oil triacylglycerols.

    PubMed

    Kamal, Md Zahid; Barrow, Colin J; Rao, Nalam Madhusudhana

    2015-04-15

    Consumption of long-chain omega-3 fatty acids is known to decrease the risk of major cardiovascular events. Lipases, a class of triacylglycerol hydrolases, have been extensively tested to concentrate omega-3 fatty acids from fish oils, under mild enzymatic conditions. However, no lipases with preference for omega-3 fatty acids selectivity have yet been discovered or developed. In this study we performed an exhaustive computational study of substrate-lipase interactions by docking, both covalent and non-covalent, for 38 lipases with a large number of structured triacylglycerols containing omega-3 fatty acids. We identified some lipases that have potential to preferentially hydrolyze omega-3 fatty acids from structured triacylglycerols. However omega-3 fatty acid preferences were found to be modest. Our study provides an explanation for absence of reports of lipases with omega-3 fatty acid hydrolyzing ability and suggests methods for developing these selective lipases. PMID:25466121

  11. Atlantic salmon (Salmo salar L.) as a net producer of long-chain marine ω-3 fatty acids.

    PubMed

    Sanden, Monica; Stubhaug, Ingunn; Berntssen, Marc H G; Lie, Øyvind; Torstensen, Bente E

    2011-12-14

    The objective of the present study was to investigate the effects of replacing high levels of marine ingredients with vegetable raw materials and with emphasis on lipid metabolism and net production of long-chain polyunsaturated ω-3 fatty acids (EPA + DHA). Atlantic salmon were fed three different replacement vegetable diets and one control marine diet before sensory attributes, β-oxidation capacity, and fatty acid productive value (FAPV) of ingested fatty acids (FAs) were evaluated. Fish fed the high replacement diet had a net production of 0.8 g of DHA and a FAPV of 142%. Fish fed the marine diet had a net loss of DHA. The present work shows that Atlantic salmon can be a net producer of marine DHA when dietary fish oil is replaced by vegetable oil with minor effects on sensory attributes and lipid metabolism. PMID:22017199

  12. Development and pathomechanisms of cardiomyopathy in very long-chain acyl-CoA dehydrogenase deficient (VLCAD(-/-)) mice.

    PubMed

    Tucci, Sara; Flögel, Ulrich; Hermann, Sven; Sturm, Marga; Schäfers, Michael; Spiekerkoetter, Ute

    2014-05-01

    Hypertrophic cardiomyopathy is a typical manifestation of very long-chain acyl-CoA dehydrogenase deficiency (VLCADD), the most common long-chain β-oxidation defects in humans; however in some patients cardiac function is fully compensated. Cardiomyopathy may also be reversed by supplementation of medium-chain triglycerides (MCT). We here characterize cardiac function of VLCAD-deficient (VLCAD(-/-)) mice over one year. Furthermore, we investigate the long-term effect of a continuous MCT diet on the cardiac phenotype. We assessed cardiac morphology and function in VLCAD(-/-) mice by in vivo MRI. Cardiac energetics were measured by (31)P-MRS and myocardial glucose uptake was quantified by positron-emission-tomography (PET). Metabolic adaptations were identified by the expression of genes regulating glucose and lipid metabolism using real-time-PCR. VLCAD(-/-) mice showed a progressive decrease in heart function over 12 months accompanied by a reduced phosphocreatine-to-ATP-ratio indicative of chronic energy deficiency. Long-term MCT supplementation aggravated the cardiac phenotype into dilated cardiomyopathy with features similar to diabetic heart disease. Cardiac energy production and function in mice with a β-oxidation defect cannot be maintained with age. Compensatory mechanisms are insufficient to preserve the cardiac energy state over time. However, energy deficiency by impaired β-oxidation and long-term MCT induce cardiomyopathy by different mechanisms. Cardiac MRI and MRS may be excellent tools to assess minor changes in cardiac function and energetics in patients with β-oxidation defects for preventive therapy. PMID:24530811

  13. Systematic investigations on the biodegradation and viscosity reduction of long chain hydrocarbons using Pseudomonas aeruginosa and Pseudomonas fluorescens.

    PubMed

    Sakthipriya, N; Doble, Mukesh; Sangwai, Jitendra S

    2016-03-01

    The use of microorganisms has been researched extensively for possible applications related to hydrocarbon degradation in the petroleum industry. However, attempts to improve the effect of microorganisms on the viscosity of hydrocarbons, which find potential use in the development of robust models for biodegradation, have been rarely documented. This study investigates the degradation of long chain hydrocarbons, such as hexadecane and eicosane using Pseudomonas fluorescens PMMD3 (P. fluorescens) and Pseudomonas aeruginosa CPCL (P. aeruginosa). P. aeruginosa used here is isolated from petroleum contaminated sediments and the P. fluorescens is from the coastal area, and both have hydrocarbon degrading genes. The degradation of hydrocarbons is studied using carbon profiling and reduction in viscosity pre- and post-degradation of hydrocarbons. The carbon profiling has been obtained using gas chromatography-mass spectroscopy (GC-MS), and Fourier transform infrared spectrometer (FTIR) results. GC-MS results have indicated an improved biodegradation of hydrocarbons by 77-93% in one day. The yield coefficients of biomass (YX/S) for P. aeruginosa and P. fluorescens using hexadecane as a carbon source are 1.35 and 0.81 g g(-1), and the corresponding values with eicosane are 0.84 and 0.88 g g(-1). The viscosity of hexadecane is reduced by the order of 53 and 47%, while that of eicosane was reduced by 53 and 65%, using P. aeruginosa and P. fluorescens, respectively. This study also presents information on the activity of enzymes responsible for the hydrocarbon degradation. Pseudomonas species have shown their use in potential applications for bioremediation, oil-spill treatment, and flow assurance. We believe that this study will also provide stringent tests for possible model development for the bioremediation of long chain paraffins suitable for oilfield applications. PMID:26875795

  14. Climate warming is predicted to reduce omega-3, long-chain, polyunsaturated fatty acid production in phytoplankton.

    PubMed

    Hixson, Stefanie M; Arts, Michael T

    2016-08-01

    Phytoplankton are the main source of energy and omega-3 (n-3) long-chain essential fatty acids (EFA) in aquatic ecosystems. Their growth and biochemical composition are affected by surrounding environmental conditions, including temperature, which continues to increase as a result of climate warming. Increasing water temperatures may negatively impact the production of EFA by phytoplankton through the process of homeoviscous adaptation. To investigate this, we conducted an exploratory data synthesis with 952 fatty acid (FA) profiles from six major groups of marine and freshwater phytoplankton. Temperature was strongly correlated with a decrease in the proportion of n-3 long-chain polyunsaturated FA (LC-PUFA) and an increase in omega-6 FA and saturated FA. Based on linear regression models, we predict that global n-3 LC-PUFA production will be reduced by 8.2% for eicosapentaenoic acid (EPA) and 27.8% for docosahexaenoic acid (DHA) with an increase in water temperature of 2.5 °C. Using a previously published estimate of the global production of EPA by diatoms, which contribute to most of the world's supply of EPA, we predict a loss of 14.2 Mt of EPA annually as a result of ocean warming. The n-3 LC-PUFA are vitally important for an array of key physiological functions in aquatic and terrestrial organisms, and these FA are mainly produced by phytoplankton. Therefore, reduced production of these EFA, as a consequence of climate warming, is predicted to negatively affect species that depend on these compounds for optimum physiological function. Such profound changes in the biochemical composition of phytoplankton cell membranes can lead to cascading effects throughout the world's ecosystems. PMID:27070119

  15. Diets containing long-chain n-3 polyunsaturated fatty acids affect behaviour differently during development than ageing in mice.

    PubMed

    Carrié, I; Guesnet, P; Bourre, J M; Francès, H

    2000-04-01

    The effect of a standard diet providing essential fatty acids enriched in fish oil or palm oil was studied in young, mature and old mice. Two groups of pregnant and lactating OF1 mice were fed on diets with or without high levels of long-chain n-3 polyunsaturated fatty acids. Offspring were maintained on these diets after weaning. The litter size did not differ. The weight increased more quickly in fish-oil-fed mice than palm-oil-fed mice. The fish-oil diet induced a significant increase in exploratory activity in young mice which was not found in mature and old mice. The level of locomotor activity was significantly higher in young, no different in mature, and lower in old fish-oil-fed mice than in controls. Habituation, the simpler form of learning, occurred to the same extent in the two diet groups. For the place learning protocol of the Morris water maze there was no difference between the two diet groups; however, in the probe trial, the mature fish-oil-fed mice remembered the situation well compared with the control mice. In the active avoidance test, on the first day of acquisition the young fish-oil-fed mice made more avoidances than control mice, whereas in contrast, mature and old-fish-fed mice made less avoidances than control mice. These results suggest a positive effect on arousal and learning ability of a diet enriched in long chain n-3 polyunsaturated fatty acids in young mice and a detrimental effect in old mice. PMID:10858702

  16. Peroxisomal multifunctional protein-2 deficiency causes neuroinflammation and degeneration of Purkinje cells independent of very long chain fatty acid accumulation.

    PubMed

    Verheijden, Simon; Bottelbergs, Astrid; Krysko, Olga; Krysko, Dmitri V; Beckers, Lien; De Munter, Stephanie; Van Veldhoven, Paul P; Wyns, Sabine; Kulik, Wim; Nave, Klaus-Armin; Ramer, Matt S; Carmeliet, Peter; Kassmann, Celia M; Baes, Myriam

    2013-10-01

    Although peroxisome biogenesis and β-oxidation disorders are well known for their neurodevelopmental defects, patients with these disorders are increasingly diagnosed with neurodegenerative pathologies. In order to investigate the cellular mechanisms of neurodegeneration in these patients, we developed a mouse model lacking multifunctional protein 2 (MFP2, also called D-bifunctional protein), a central enzyme of peroxisomal β-oxidation, in all neural cells (Nestin-Mfp2(-/-)) or in oligodendrocytes (Cnp-Mfp2(-/-)) and compared these models with an already established general Mfp2 knockout. Nestin-Mfp2 but not Cnp-Mfp2 knockout mice develop motor disabilities and ataxia, similar to the general mutant. Deterioration of motor performance correlates with the demise of Purkinje cell axons in the cerebellum, which precedes loss of Purkinje cells and cerebellar atrophy. This closely mimics spinocerebellar ataxias of patients affected with mild peroxisome β-oxidation disorders. However, general knockouts have a much shorter life span than Nestin-Mfp2 knockouts which is paralleled by a disparity in activation of the innate immune system. Whereas in general mutants a strong and chronic proinflammatory reaction proceeds throughout the brain, elimination of MFP2 from neural cells results in minor neuroinflammation. Neither the extent of the inflammatory reaction nor the cerebellar degeneration could be correlated with levels of very long chain fatty acids, substrates of peroxisomal β-oxidation. In conclusion, MFP2 has multiple tasks in the adult brain, including the maintenance of Purkinje cells and the prevention of neuroinflammation but this is not mediated by its activity in oligodendrocytes nor by its role in very long chain fatty acid degradation. PMID:23777740

  17. fadD deletion and fadL overexpression in Escherichia coli increase hydroxy long-chain fatty acid productivity.

    PubMed

    Bae, Jin H; Park, Beom Gi; Jung, Eunok; Lee, Pyung-Gang; Kim, Byung-Gee

    2014-11-01

    A major problem of long-chain fatty acid (LCFA) hydroxylation using Escherichia coli is that FadD (long-chain fatty acyl-CoA synthetase), which is necessary for exogenous LCFA transport, also initiates cellular consumption of LCFA. In this study, an effective method to prevent the cellular consumption of LCFA without impairing its transport is proposed. The main idea is that a heterologous enzyme which consumes LCFA can replace FadD in LCFA transport. For the model heterologous enzyme, CYP153A from Marinobacter aquaeolei, which converts palmitic acid into ω-hydroxy palmitic acid, was expressed in E. coli. When fadD was deleted from an E. coli strain, CYP153A indeed maintained the ability to transport LCFA. A disadvantage of fadD deletion mutant is the fact that FadD deficiency downregulates the transcription of fadL (outer membrane LCFA transporter) via FadR (fatty acid metabolism regulator protein), was solved by fadL overexpression from a plasmid. In addition, the overexpression of fadL was able to offset catabolite repression on fadL, allowing glucose to be used as the primary carbon source. In conclusion, the strain with fadD deletion and fadL overexpression showed 5.5-fold increase in productivity compared to the wild-type strain, converting 2.6 g/L (10.0 mM) of palmitic acid into 2.4 g/L (8.8 mM) of ω-hydroxy palmitic acid in a shake flask. This simple genetic manipulation can be applied to any LCFA hydroxylation using E. coli. PMID:25117545

  18. Long-chain ω-3 fatty acid intake and endometrial cancer risk in the Women’s Health Initiative12345

    PubMed Central

    Brasky, Theodore M; Rodabough, Rebecca J; Liu, Jingmin; Kurta, Michelle L; Wise, Lauren A; Orchard, Tonya S; Cohn, David E; Belury, Martha A; White, Emily; Manson, JoAnn E; Neuhouser, Marian L

    2015-01-01

    Background: Inflammation may be important in endometrial cancer development. Long-chain ω-3 (n–3) polyunsaturated fatty acids (LCω-3PUFAs) may reduce inflammation and, therefore, reduce cancer risk. Because body mass is associated with both inflammation and endometrial cancer risk, it may modify the association of fat intake on risk. Objective: We examined whether intakes of LCω-3PUFAs were associated with endometrial cancer risk overall and stratified by body size and histologic subtype. Design: Women were n = 87,360 participants of the Women’s Health Initiative Observational Study and Clinical Trials who were aged 50–79 y, had an intact uterus, and completed a baseline food-frequency questionnaire. After 13 y of follow-up, n = 1253 incident invasive endometrial cancers were identified. Cox regression models were used to estimate HRs and 95% CIs for the association of intakes of individual ω-3 fatty acids and fish with endometrial cancer risk. Results: Intakes of individual LCω-3PUFAs were associated with 15–23% linear reductions in endometrial cancer risk. In women with body mass index (BMI; in kg/m2) <25, those in the upper compared with lowest quintiles of total LCω-3PUFA intake (sum of eicosapentaenoic, docosapentaenoic, and docosahexaenoic acids) had significantly reduced endometrial cancer risk (HR: 0.59; 95% CI: 0.40, 0.82; P-trend = 0.001), whereas there was little evidence of an association in overweight or obese women. The reduction in risk observed in normal-weight women was further specific to type I cancers. Conclusions: Long-chain ω-3 intake was associated with reduced endometrial cancer risk only in normal-weight women. Additional studies that use biomarkers of ω-3 intake are needed to more accurately estimate their effects on endometrial cancer risk. This trial was registered at clinicaltrials.gov as NCT00000611. PMID:25739930

  19. Solubilisation of poorly water-soluble drugs during in vitro lipolysis of medium- and long-chain triacylglycerols.

    PubMed

    Christensen, Janne Ørskov; Schultz, Kirsten; Mollgaard, Birgitte; Kristensen, Henning Gjelstrup; Mullertz, Anette

    2004-11-01

    The partitioning of poorly soluble drugs into an aqueous micellar phase was exploited using an in vitro lipid digestion model, simulating the events taking place during digestion of acylglycerols in the duodenum. The aqueous micellar phase was isolated after ultracentrifugation of samples obtained at different degrees of triacylglycerol hydrolysis. Flupentixol, 1'-[4-[1-(4-fluorophenyl)-1-H-indol-3-yl]-1-butyl]spiro[iso-benzofuran-1(3H), 4' piperidine] (LU 28-179) and probucol were studied. The effect of the alkyl chain length of the triacylglycerol was studied using a medium-chain triacylglycerol (MCT) and a long-chain triacylglycerol (LCT), respectively. In general, an oil solution was used as the lipid source in the model. Samples were analysed in regard to micellar size, lipid composition and drug concentration. During lipolysis, the content of lipolytic products in the aqueous micellar phase increased. The micellar size (R(H) approximately 3 nm) only increased when long-chain lipolytic products were incorporated in the mixed micelles (R(H) approximately 7.8 nm). Flupentixol was quickly transferred to the mixed micelles due to high solubility in this phase (100% released). A tendency towards higher solubilisation of LU 28-179, when it was administered in the LCT (approximately 24% released) compared to when it was administered in the MCT (approximately 15% released) at 70% hydrolysis, and a lagphase was observed. There was no difference in the solubilisation of probucol using MCT or LCT ( approximately 20% released), respectively. Differences in the physicochemical properties of the drugs resulted in differences in their distribution between the phases arising during lipolysis. PMID:15489130

  20. Crystal structures of SIRT3 reveal that the α2-α3 loop and α3-helix affect the interaction with long-chain acyl lysine.

    PubMed

    Gai, Wei; Li, He; Jiang, Hualiang; Long, Yaqiu; Liu, Dongxiang

    2016-09-01

    SIRT1-7 play important roles in many biological processes and age-related diseases. In addition to a NAD(+) -dependent deacetylase activity, they can catalyze several other reactions, including the hydrolysis of long-chain fatty acyl lysine. To study the binding modes of sirtuins to long-chain acyl lysines, we solved the crystal structures of SIRT3 bound to either a H3K9-myristoylated- or a H3K9-palmitoylated peptide. Interaction of SIRT3 with the palmitoyl group led to unfolding of the α3-helix. The myristoyl and palmitoyl groups bind to the C-pocket and an allosteric site near the α3-helix, respectively. We found that the residues preceding the α3-helix determine the size of the C-pocket. The flexibility of the α2-α3 loop and the plasticity of the α3-helix affect the interaction with long-chain acyl lysine. PMID:27501476

  1. Rhizobial homologs of the fatty acid transporter FadL facilitate perception of long-chain acyl-homoserine lactone signals

    PubMed Central

    Krol, Elizaveta; Becker, Anke

    2014-01-01

    Quorum sensing (QS) using N-acyl homoserine lactones (AHLs) as signal molecules is a common strategy used by diverse Gram-negative bacteria. A widespread mechanism of AHL sensing involves binding of these molecules by cytosolic LuxR-type transcriptional regulators, which requires uptake of external AHLs. The outer membrane is supposed to be an efficient barrier for diffusion of long-chain AHLs. Here we report evidence that in Sinorhizobium meliloti, sensing of AHLs with acyl chains composed of 14 or more carbons is facilitated by the outer membrane protein FadLSm, a homolog of the Escherichia coli FadLEc long-chain fatty acid transporter. The effect of fadLSm on AHL sensing was more prominent for longer and more hydrophobic signal molecules. Using reporter gene fusions to QS target genes, we found that fadLSm increased AHL sensitivity and accelerated the course of QS. In contrast to FadLEc, FadLSm did not support uptake of oleic acid, but did contribute to growth on palmitoleic acid. FadLSm homologs from related symbiotic α-rhizobia and the plant pathogen Agrobacterium tumefaciens differed in their ability to facilitate long-chain AHL sensing or to support growth on oleic acid. FadLAt was found to be ineffective toward long-chain AHLs. We obtained evidence that the predicted extracellular loop 5 of FadLSm and further α-rhizobial FadL proteins contains determinants of specificity to long-chain AHLs. Replacement of a part of loop 5 by the corresponding region from α-rhizobial FadL proteins transferred sensitivity for long-chain AHLs to FadLAt. PMID:25002473

  2. One carbon metabolism in anaerobic bacteria: Regulation of carbon and electron flow during organic acid production

    SciTech Connect

    Zeikus, J.G.; Jain, M.

    1993-12-31

    The project deals with understanding the fundamental biochemical mechanisms that physiologically control and regulate carbon and electron flow in anaerobic chemosynthetic bacteria that couple metabolism of single carbon compounds and hydrogen to the production of organic acids (formic, acetic, butyric, and succinic) or methane. The authors compare the regulation of carbon dioxide and hydrogen metabolism by fermentation, enzyme, and electron carrier analysis using Butyribacterium methylotrophicum, Anaeroblospirillum succiniciproducens, Methanosarcina barkeri, and a newly isolated tri-culture composed of a syntrophic butyrate degrader strain IB, Methanosarcina mazei and Methanobacterium formicicum as model systems. To understand the regulation of hydrogen metabolism during butyrate production or acetate degradation, hydrogenase activity in B. methylotrophicum or M. barkeri is measured in relation to growth substrate and pH; hydrogenase is purified and characterized to investigate number of hydrogenases; their localization and functions; and, their sequences are determined. To understand the mechanism for catabolic CO{sub 2} fixation to succinate the PEP carboxykinase enzyme and gene of A. succiniciproducens are purified and characterized. Genetically engineered strains of Escherichia coli containing the phosphoenolpyruvate (PEP) carboxykinase gene are examined for their ability to produce succinate in high yield. To understand the mechanism of fatty acid degradation by syntrophic acetogens during mixed culture methanogenesis formate and hydrogen production are characterized by radio tracer studies. It is intended that these studies provide strategies to improve anaerobic fermentations used for the production of organic acids or methane and, new basic understanding on catabolic CO{sub 2} fixation mechanisms and on the function of hydrogenase in anaerobic bacteria.

  3. Sex Differences in Long Chain Fatty Acid Utilization and Fatty Acid Binding Protein Concentration in Rat Liver

    PubMed Central

    Ockner, Robert K.; Burnett, David A.; Lysenko, Nina; Manning, Joan A.

    1979-01-01

    Female sex and estrogen administration are associated with increased hepatic production of triglyceride-rich lipoproteins; the basis for this has not been fully elucidated. Inasmuch as hepatic lipoprotein production is also influenced by FFA availability and triglyceride biosynthesis, we investigated sex differences in FFA utilization in rat hepatocyte suspensions and in the components of the triglyceride biosynthetic pathway. Isolated adult rat hepatocyte suspensions were incubated with albumin-bound [14C]oleate for up to 15 min. At physiological and low oleate concentrations, cells from females incorporated significantly more 14C into glycerolipids, especially triglycerides, and into oxidation products than did male cells, per milligram cell protein. At 0.44 mM oleate, incorporation into triglycerides in female cells was approximately twice that in male cells. Comparable sex differences were observed in cells from fasted animals and when [14C]-glycerol incorporation was measured. At higher oleate concentrations, i.e., fatty acid:albumin mole ratios in excess of 2:1, these sex differences were no longer demonstrable, suggesting that maximal rates of fatty acid esterification and oxidation were similar in female and male cells. In female and male hepatic microsomes, specific activities of long chain acyl coenzyme A synthetase, phosphatidate phosphohydrolase, and diglyceride acyltransferase were similar, but glycerol-3-phosphate acyltransferase activity was slightly greater in females at certain substrate concentrations. Microsomal incorporation of [14C]oleate into total glycerolipids was not significantly greater in females. In further contrast to intact cells, microsomal incorporation of [14C]oleate into triglycerides, although significantly greater in female microsomes, accounted for only a small fraction of the fatty acid esterified. The binding affinity and stoichiometry of partially purified female hepatic fatty acid binding protein (FABP) were similar to

  4. Influence of an n-3 long-chain polyunsaturated fatty acid-enriched diet on experimentally induced synovitis in horses.

    PubMed

    Ross-Jones, T N; McIlwraith, C W; Kisiday, J D; Hess, T M; Hansen, D K; Black, J

    2016-06-01

    Dietary n-3 long-chain polyunsaturated fatty acid (LCPUFA) supplementation has previously been shown to modify joint-related inflammation in several species, although information in the horse is lacking. We investigated whether dietary supplementation with n-3 LCPUFA would modify experimentally induced synovitis in horses. Twelve, skeletally mature, non-pregnant mares were randomly assigned to either a control diet (CONT) or an n-3 long-chain fatty acid-enriched treatment diet (N3FA) containing 40 g/day of n-3 LCPUFA for 91 days. Blood samples taken on days 0, 30, 60 and 90, and synovial fluid collected on days 0 and 90 were processed for lipid composition. On day 91, joint inflammation was stimulated using an intra-articular (IA) injection of 100 ng of recombinant equine IL-1beta (reIL-1β). Synovial fluid samples taken at post-injection hours (PIH) 0, 4, 8 and 24 were analysed for prostaglandin E2 (PGE2 ), matrix metalloproteinase (MMP) activity and routine cytology. Synovium and articular cartilage samples collected at PIH 8 were analysed for gene expression of MMP 1 and MMP 13, interleukin-1beta (IL-1β), cyclooxygenase 2 (COX-2), tumour necrosis factor-alpha and the aggrecanases, a disintegrin and metalloprotease with thrombospondin motifs (ADAMTS)-4 and ADAMTS-5. A 90-day feeding period of n-3 LCPUFA increased serum phospholipid and synovial fluid lipid compositions of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) compared to CONT horses. The reIL-1β injection caused an inflammatory response; however, there was no effect of dietary treatment on synovial fluid PGE2 content and MMP activity. Synovial tissue collected from N3FA horses exhibited lower expression of ADAMTS-4 compared to CONT horses. Despite the presence of EPA and DHA in the synovial fluid of N3FA horses, dietary n-3 LCPUFA supplementation did not modify synovial fluid biomarkers compared to CONT horses; however, the lower ADAMTS-4 mRNA expression in N3FA synovium warrants further

  5. Effect of methanogenic substrates on anaerobic oxidation of methane and sulfate reduction by an anaerobic methanotrophic enrichment

    PubMed Central

    Jagersma, Christian G.; Khadem, Ahmad F.; Stams, Alfons J. M.; Lens, Piet N. L.

    2010-01-01

    Anaerobic oxidation of methane (AOM) coupled to sulfate reduction (SR) is assumed to be a syntrophic process, in which methanotrophic archaea produce an interspecies electron carrier (IEC), which is subsequently utilized by sulfate-reducing bacteria. In this paper, six methanogenic substrates are tested as candidate-IECs by assessing their effect on AOM and SR by an anaerobic methanotrophic enrichment. The presence of acetate, formate or hydrogen enhanced SR, but did not inhibit AOM, nor did these substrates trigger methanogenesis. Carbon monoxide also enhanced SR but slightly inhibited AOM. Methanol did not enhance SR nor did it inhibit AOM, and methanethiol inhibited both SR and AOM completely. Subsequently, it was calculated at which candidate-IEC concentrations no more Gibbs free energy can be conserved from their production from methane at the applied conditions. These concentrations were at least 1,000 times lower can the final candidate-IEC concentration in the bulk liquid. Therefore, the tested candidate-IECs could not have been produced from methane during the incubations. Hence, acetate, formate, methanol, carbon monoxide, and hydrogen can be excluded as sole IEC in AOM coupled to SR. Methanethiol did inhibit AOM and can therefore not be excluded as IEC by this study. PMID:20445975

  6. First insights into the syntrophic acetate-oxidizing bacteria – a genetic study

    PubMed Central

    Müller, Bettina; Sun, Li; Schnürer, Anna

    2013-01-01

    Syntrophic acetate-oxidizing bacteria have been identified as key organisms for efficient biogas production from protein-rich materials. They normally grow as lithotrophs or heterotrophs, producing acetate through the Wood–Ljungdahl pathway, but when growing in syntrophy with methanogens, they reportedly reverse this pathway and oxidize acetate to hydrogen and carbon dioxide. However, the biochemical and regulatory mechanisms behind the shift and the way in which the bacteria regain energy remain unknown. In a genome-walking approach, starting with degenerated primers, we identified those gene clusters in Syntrophaceticus schinkii, Clostridium ultunense, and Tepidanaerobacter acetatoxydans that comprise the formyltetrahydrofolate synthetase gene (fhs), encoding a key enzyme of the Wood–Ljungdahl pathway. We also discovered that the latter two harbor two fhs alleles. The fhs genes are phylogenetically separated and in the case of S. schinkii functionally linked to sulfate reducers. The T. acetatoxydans fhs1 cluster combines features of acetogens, sulfate reducers, and carbon monoxide oxidizers and is organized as a putative operon. The T. acetatoxydans fhs2 cluster encodes Wood–Ljungdahl pathway enzymes, which are also known to be involved in C1 carbon metabolism. Isolation of the enzymes illustrated that both formyltetrahydrofolate synthetases of T. acetatoxydans were functionally active. However, only fhs1 was expressed, confirming bidirectional usage of the pathway. PMID:23239474

  7. Syntrophic degradation of proteinaceous materials by the thermophilic strains Coprothermobacter proteolyticus and Methanothermobacter thermautotrophicus.

    PubMed

    Sasaki, Kengo; Morita, Masahiko; Sasaki, Daisuke; Nagaoka, Jun; Matsumoto, Norio; Ohmura, Naoya; Shinozaki, Hiraku

    2011-11-01

    Protein is a major component of organic solid wastes, and therefore, it is necessary to further elucidate thermophilic protein degradation process. The effects of hydrogenotrophic methanogens on protein degradation were investigated using the proteolytic bacterial strain CT-1 that was isolated from a methanogenic thermophilic (55°C) packed-bed reactor degrading artificial garbage slurry. Strain CT-1 was closely related to Coprothermobacter proteolyticus, which is frequently found in methanogenic reactors degrading organic solid wastes. Strain CT-1 was cultivated in the absence or presence of Methanothermobacter thermautotrophicus by using 3 kinds of proteinaceous substrates. Degradation rates of casein, gelatin, and bovine serum albumin were higher in co-cultures than in monocultures. Strain CT-1 showed faster growth in co-cultures than in monocultures. M. thermautotrophicus comprised 5.5-6.0% of the total cells in co-culture. Increased production of ammonia and acetate was observed in co-cultures than in monocultures, suggesting that addition of M. thermautotrophicus increases the products of protein degradation. Hydrogen produced in the monocultures was converted to methane in co-cultures. These results suggest that thermophilic proteolytic bacteria find it favorable to syntrophically degrade protein in a methanogenic environment, and that it is important to retain hydrogen-scavenging methanogens within the reactor. PMID:21802987

  8. Dynamic energy budgets in syntrophic symbiotic relationships between heterotrophic hosts and photoautotrophic symbionts.

    PubMed

    Muller, Erik B; Kooijman, Sebastiaan A L M; Edmunds, Peter J; Doyle, Francis J; Nisbet, Roger M

    2009-07-01

    In this paper we develop and investigate a dynamic energy budget (DEB) model describing the syntrophic symbiotic relationship between a heterotrophic host and an internal photoautotrophic symbiont. The model specifies the flows of matter and energy among host, symbiont and environment with minimal complexity and uses the concept of synthesizing units to describe smoothly the assimilation of multiple limiting factors, in particular inorganic carbon and nitrogen, and irradiance. The model has two passive regulation mechanisms: the symbiont shares only photosynthate that it cannot use itself, and the host delivers only excess nutrients to the symbiont. With parameter values plausible for scleractinian corals, we show that these two regulation mechanisms suffice to obtain a stable symbiotic relationship under constant ambient conditions, provided those conditions support sustenance of host and symbiont. Furthermore, the symbiont density in the host varies relatively little as a function of ambient food density, inorganic nitrogen and irradiance. This symbiont density tends to increase with light deprivation or nitrogen enrichment, either directly or via food. We also investigate the relative benefit each partner derives from the relationship and conclude that this relationship may shift from mutualism to parasitism as environmental conditions change. PMID:19285512

  9. Brain white matter development is associated with a human-specific haplotype increasing the synthesis of long chain fatty acids.

    PubMed

    Peters, Bart D; Voineskos, Aristotle N; Szeszko, Philip R; Lett, Tristram A; DeRosse, Pamela; Guha, Saurav; Karlsgodt, Katherine H; Ikuta, Toshikazu; Felsky, Daniel; John, Majnu; Rotenberg, David J; Kennedy, James L; Lencz, Todd; Malhotra, Anil K

    2014-04-30

    The genetic and molecular pathways driving human brain white matter (WM) development are only beginning to be discovered. Long chain polyunsaturated fatty acids (LC-PUFAs) have been implicated in myelination in animal models and humans. The biosynthesis of LC-PUFAs is regulated by the fatty acid desaturase (FADS) genes, of which a human-specific haplotype is strongly associated with ω-3 and ω-6 LC-PUFA concentrations in blood. To investigate the relationship between LC-PUFA synthesis and human brain WM development, we examined whether this FADS haplotype is associated with age-related WM differences across the life span in healthy individuals 9-86 years of age (n = 207). Diffusion tensor imaging was performed to measure fractional anisotropy (FA), a putative measure of myelination, of the cerebral WM tracts. FADS haplotype status was determined with a single nucleotide polymorphism (rs174583) that tags this haplotype. Overall, normal age-related WM differences were observed, including higher FA values in early adulthood compared with childhood, followed by lower FA values across older age ranges. However, individuals homozygous for the minor allele (associated with lower LC-PUFA concentrations) did not display these normal age-related WM differences (significant age × genotype interactions, p(corrected) < 0.05). These findings suggest that LC-PUFAs are involved in human brain WM development from childhood into adulthood. This haplotype and LC-PUFAs may play a role in myelin-related disorders of neurodevelopmental origin. PMID:24790207

  10. Shear-induced enhancements of crystallization kinetics and morphological transformation for long chain branched polylactides with different branching degrees

    NASA Astrophysics Data System (ADS)

    Wang, Junyang; Bai, Jing; Zhang, Yaqiong; Fang, Huagao; Wang, Zhigang

    2016-06-01

    The effects of long chain branching (LCB) degree on the shear-induced isothermal crystallization kinetics of a series of LCB polylactides (LCB PLAs) have been investigated by using rotational rheometer, polarized optical microscopy (POM) and scanning electron microscopy (SEM). Dynamic viscoelastic properties obtained by small-amplitude oscillatory shear (SAOS) tests indicate that LCB PLAs show more broadened relaxation time spectra with increasing LCB degree. Upon a pre-shear at the shear rate of 1 s‑1 LCB PLAs show much faster crystallization kinetics than linear PLA and the crystallization kinetics is enhanced with increasing LCB degree. By modeling the system as a suspension the quantitative evaluation of nucleation density can be derived from rheological experiments. The nucleation density is greatly enhanced with increasing LCB degree and a saturation in shear time is observed. Crystalline morphologies for LCB PLAs observed by POM and SEM demonstrate the enhancement of nucleation density with increasing LCB degree and a transformation from spherulitic to orientated crystalline morphologies. The observation can be ascribed to longer relaxation time of the longest macromolecular chains and broadened, complex relaxation behaviors due to the introduction of LCB into PLA, which is essential in stabilizing the orientated crystal nuclei after pre-shear.

  11. [Differences in percent composition of long chain polyunsaturated fatty acids in maternal-fetal erythrocytes in term and preterm infants].

    PubMed

    Araya Araya, J; Rojas García, M; Fernández Fraile, P; Mateluna Acevedo, A

    1998-09-01

    The content and distribution of long-chain polyunsaturated fatty acids (LCP) of maternal-fetal erythrocytes phospholipids was investigated. Blood samples from healthy pregnant women were taken from maternal veins and umbilical cord at spontaneous delivery time. Two groups were segregated and compared in terms of fetuses gestational age: preterm delivery (32-34 weeks) and term delivery (40 weeks). The results showed that in erythrocytes of term newborn the content of LCP omega 6 and omega 3; particularly 20:4w6 (ARA) and 22:6w3 (DHA), were found to be statistically higher than their respective mother. However, in preterm newborns, all LCP from phospholipids erythrocytes were found to be statistically lower than in their mother. Comparing the content of ARA and DHA between the newborn groups, it observed that only DHA was decreased in preterm group. Women who delivered premature babies showed a blood ratio ARA/DHA higher than those who delivered term-babies. From this study and considering previous information it can be suggested that a high content of ARA and ARA/DHA ratio in maternal and fetal erythrocytes may considered an early risk signal of preterm delivery. PMID:9951532

  12. A carbon nanotube/poly [Ni-(Protoporphyrin IX)] composite for amperometric detection of long chain aliphatic amines.

    PubMed

    Carballo, Romina; Rinaldi, Ana L; Dabas, Paula C; Rezzano, Irene N

    2015-08-01

    Poly [Ni-Protoporphyrin] film (pNiPP), containing multiwall carbon nanotubes (MWCNT) was used to cover a glassy carbon electrode. The hybrid material (pNiPP/MWCNT) successfully combines the permselectivity of pNiPP with the high conductivity of MWCNT. The modified electrode was used to perform amperometric detection of long chain aliphatic amines (LCAA) in order to prevent the passivation effect of the aliphatic chain. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) demonstrated that the pNiPP/MWCNT facilitates the electron transfer reaction. The charge transfer resistance (Rct) values were significantly lower by up to one order of magnitude compared to the bare electrode. Differential pulse polarography (DPP) showed a marked decrease of the overpotential generated by the aliphatic chain. The calibration of the amperometric peak area vs. concentrations of derivatized LCAA exhibits a linear response within the range of 0.018 and 28 μM and correlation coefficient (R(2)) higher than 0.999 (n=5). The quantitation limit of the pNiPP/MWCNT electrode is about 400 times lower than the UV-visible detection. RSD of 7.2%, 5.8%, 2.5% and 2.3% was obtained for concentrations of 0.028, 0.28, 2.8 and 28 μM of ferrocenyl octadecylamine. A solution of sphingosine, 0.23 μM, was exclusively detected with HPLC-ECD with pNiPP/MWCNT electrode. PMID:25827578

  13. Altered Energetics of Exercise Explain Risk of Rhabdomyolysis in Very Long-Chain Acyl-CoA Dehydrogenase Deficiency.

    PubMed

    Diekman, E F; Visser, G; Schmitz, J P J; Nievelstein, R A J; de Sain-van der Velden, M; Wardrop, M; Van der Pol, W L; Houten, S M; van Riel, N A W; Takken, T; Jeneson, J A L

    2016-01-01

    Rhabdomyolysis is common in very long-chain acyl-CoA dehydrogenase deficiency (VLCADD) and other metabolic myopathies, but its pathogenic basis is poorly understood. Here, we show that prolonged bicycling exercise against a standardized moderate workload in VLCADD patients is associated with threefold bigger changes in phosphocreatine (PCr) and inorganic phosphate (Pi) concentrations in quadriceps muscle and twofold lower changes in plasma acetyl-carnitine levels than in healthy subjects. This result is consistent with the hypothesis that muscle ATP homeostasis during exercise is compromised in VLCADD. However, the measured rates of PCr and Pi recovery post-exercise showed that the mitochondrial capacity for ATP synthesis in VLCADD muscle was normal. Mathematical modeling of oxidative ATP metabolism in muscle composed of three different fiber types indicated that the observed altered energy balance during submaximal exercise in VLCADD patients may be explained by a slow-to-fast shift in quadriceps fiber-type composition corresponding to 30% of the slow-twitch fiber-type pool in healthy quadriceps muscle. This study demonstrates for the first time that quadriceps energy balance during exercise in VLCADD patients is altered but not because of failing mitochondrial function. Our findings provide new clues to understanding the risk of rhabdomyolysis following exercise in human VLCADD. PMID:26881790

  14. An efficient method for isolating individual long-chain alkenones for compound-specific hydrogen isotope analysis.

    PubMed

    D'Andrea, William J; Liu, Zhonghui; Da Rosa Alexandre, Marcelo; Wattley, Sarah; Herbert, Timothy D; Huang, Yongsong

    2007-05-01

    Hydrogen isotope ratios (2H/H or D/H) of long-chain unsaturated ketones (alkenones) preserved in lake and marine sediments hold great promise for paleoclimate studies. However, compound-specific hydrogen isotope analysis of individual alkenones has not been possible due to chromatographic coelution of alkenones with the same carbon chain length but different numbers of double bonds. Published studies have only reported the deltaD values of the mixture of coeluting alkenones. We developed an efficient procedure to isolate individual alkenones based on double-bond numbers using silica gel impregnated with silver nitrate. The chromatographic procedure is simple, inexpensive, and highly reproducible, offers 87-100% sample recovery, and allows for the first time hydrogen isotopic measurement on individual alkenones. deltaD values of specific di-, tri- and tetraunsaturated C37 alkenones produced by an Emiliania huxleyi culture, as well as those isolated from Greenland lake sediments, differ consecutively by 43-65 per thousand. These findings suggest that alkenones with different numbers of carbon-carbon double bonds express significantly different deltaD values and that coelution of different alkenones may lead to erroneous source water deltaD reconstructions. Our alkenone isolation approach opens a new avenue for paleoclimate reconstructions using hydrogen isotope ratios of individual alkenones. PMID:17391004

  15. Long-chain bases, phosphatidic acid, MAPKs, and reactive oxygen species as nodal signal transducers in stress responses in Arabidopsis

    PubMed Central

    Saucedo-García, Mariana; Gavilanes-Ruíz, Marina; Arce-Cervantes, Oscar

    2015-01-01

    Due to their sessile condition, plants have developed sensitive, fast, and effective ways to contend with environmental changes. These mechanisms operate as informational wires conforming extensive and intricate networks that are connected in several points. The responses are designed as pathways orchestrated by molecules that are transducers of protein and non-protein nature. Their chemical nature imposes selective features such as specificity, formation rate, and generation site to the informational routes. Enzymes such as mitogen-activated protein kinases and non-protein, smaller molecules, such as long-chain bases, phosphatidic acid, and reactive oxygen species are recurrent transducers in the pleiotropic responses to biotic and abiotic stresses in plants. In this review, we considered these four components as nodal points of converging signaling pathways that start from very diverse stimuli and evoke very different responses. These pleiotropic effects may be explained by the potentiality that every one of these four mediators can be expressed from different sources, cellular location, temporality, or magnitude. Here, we review recent advances in our understanding of the interplay of these four specific signaling components in Arabidopsis cells, with an emphasis on drought, cold and pathogen stresses. PMID:25763001

  16. Chlamydia trachomatis growth and development requires the activity of host Long-chain Acyl-CoA Synthetases (ACSLs)

    PubMed Central

    Recuero-Checa, Maria A.; Sharma, Manu; Lau, Constance; Watkins, Paul A.; Gaydos, Charlotte A.; Dean, Deborah

    2016-01-01

    The obligate-intracellular pathogen Chlamydia trachomatis (Ct) has undergone considerable genome reduction with consequent dependence on host biosynthetic pathways, metabolites and enzymes. Long-chain acyl-CoA synthetases (ACSLs) are key host-cell enzymes that convert fatty acids (FA) into acyl-CoA for use in metabolic pathways. Here, we show that the complete host ACSL family [ACSL1 and ACSL3–6] translocates into the Ct membrane-bound vacuole, termed inclusion, and remains associated with membranes of metabolically active forms of Ct throughout development. We discovered that three different pharmacologic inhibitors of ACSL activity independently impede Ct growth in a dose-dependent fashion. Using an FA competition assay, host ACSLs were found to activate Ct branched-chain FAs, suggesting that one function of the ACSLs is to activate Ct FAs and host FAs (recruited from the cytoplasm) within the inclusion. Because the ACSL inhibitors can deplete lipid droplets (LD), we used a cell line where LD synthesis was switched off to evaluate whether LD deficiency affects Ct growth. In these cells, we found no effect on growth or on translocation of ACSLs into the inclusion. Our findings support an essential role for ACSL activation of host-cell and bacterial FAs within the inclusion to promote Ct growth and development, independent of LDs. PMID:26988341

  17. Altered development and function of the placental regions in preeclampsia and its association with long-chain polyunsaturated fatty acids.

    PubMed

    Rani, Alka; Wadhwani, Nisha; Chavan-Gautam, Preeti; Joshi, Sadhana

    2016-09-01

    The placenta is an essential organ formed during pregnancy that mainly transfers nutrients from the mother to the fetus. Nutrients taken up by the placenta are required for its own growth and development and to optimize fetal growth. Hence, placental function is an important determinant of pregnancy outcome. Among various nutrients, fatty acids, especially long-chain polyunsaturated fatty acids (LCPUFAs), including omega 3 and omega 6 fatty acids, are essential for placental development from the time of implantation. Studies have associated these LCPUFAs with placental development through their roles in regulating oxidative stress, angiogenesis, and inflammation, which may in turn influence their transfer to the fetus. The placenta has a heterogeneous morphology with variable regional vasculature, oxidative stress, and LCPUFA levels in healthy pregnancies depending upon the location within the placenta. However, these regional structural and functional parameters are found to be disturbed in pathological conditions, such as preeclampsia (PE), thereby affecting pregnancy outcome. Hence, the alterations in LCPUFA metabolism and transport in different regions of the PE placenta as compared with normal placenta could potentially be contributing to the pathological features of PE. The regional variations in development and function of the placenta and its possible association with placental LCPUFA metabolism and transport in normal and PE pregnancies are discussed in this review. WIREs Dev Biol 2016, 5:582-597. doi: 10.1002/wdev.238 For further resources related to this article, please visit the WIREs website. PMID:27239793

  18. Assessment of crude glycerol for Enhanced Biological Phosphorus Removal: Stability and role of long chain fatty acids.

    PubMed

    Tayà, Carlota; Guerrero, Javier; Suárez-Ojeda, María Eugenia; Guisasola, Albert; Baeza, Juan Antonio

    2015-12-01

    Enhanced Biological Phosphorus Removal (EBPR) of urban wastewaters is usually limited by the available carbon source required by Polyphosphate Accumulating Organisms (PAO). External carbon sources as volatile fatty acids (VFA) or other pure organic compounds have been tested at lab scale demonstrating its ability to enhance PAO activity, but the application of this strategy at full-scale WWTPs is not cost-effective. The utilization of industrial by-products with some of these organic compounds provides lower cost, but it has the possible drawback of having inhibitory or toxic compounds to PAO. This study is focused on the utilization of crude glycerol, the industrial by-product generated in the biodiesel production, as a possible carbon source to enhance EBPR in carbon-limited urban wastewaters. Crude glycerol has non-negligible content of other organic compounds as methanol, salts, VFA and long chain fatty acids (LCFA). VFA and methanol have been demonstrated to enhance PAO activity, but there is no previous study about the effect of LCFA on PAO. This work presents the operation of an EBPR SBR system using crude glycerol as sole carbon source, studying also its long-term stability. The effect of LCFA is evaluated at short and long-term operation, demonstrating for the first time EBPR activity with LCFA as sole carbon source and its long-term failure due to the increased hydrophobicity of the sludge. PMID:26092200

  19. Application of novel catalytic-ceramic-filler in a coupled system for long-chain dicarboxylic acids manufacturing wastewater treatment.

    PubMed

    Wu, Suqing; Qi, Yuanfeng; Fan, Chunzhen; He, Shengbing; Dai, Bibo; Huang, Jungchen; Zhou, Weili; Gao, Lei

    2016-02-01

    To gain systematic technology for long-chain dicarboxylic acids (LDCA) manufacturing wastewater treatment, catalytic micro-electrolysis (CME) coupling with adsorption-biodegradation sludge (AB) process was studied. Firstly, novel catalytic-ceramic-filler was prepared from scrap iron, clay and copper sulfate solution and packed in the CME reactor. To remove residual n-alkane and LDCA, the CME reactor was utilized for LDCA wastewater pretreatment. The results revealed that about 94% of n-alkane, 98% of LDCA and 84% of chemical oxygen demand (COD) were removed by the aerated CME reactor at the optimum hydraulic retention time (HRT) of 3.0 h. In this process, catalysis from Cu and montmorillonites played an important role in improving the contaminants removal. Secondly, to remove residual COD in the wastewater, AB process was designed for the secondary biological treatment, about 90% of the influent COD could be removed by biosorption, bio-flocculation and biodegradation effects. Finally, the effluent COD (about 150 mg L(-1)) discharged from the coupled CME-AB system met the requirement of the national discharged standard (COD ≤ 300 mg L(-1)). All of these results suggest that the coupled CME-AB system is a promising technology due to its high-efficient performance, and has the potential to be applied for the real LDCA wastewater treatment. PMID:26619310

  20. Development of a human health oral risk factor for long chain petroleum hydrocarbons. Final report, May-October 1994

    SciTech Connect

    Staats, D.A.

    1994-10-01

    The primary objective of the research presented herein was to develop oral risk factors for long chain petroleum hydrocarbons (LCPHs). Literature searches were conducted on petroleum products and specific LCPHs. Over 5,000 references were identified and over 100 references were reviewed. Information was collected on the chemical composition and analysis of total petroleum hydrocarbons (TPH); the environmental regulation of TPH in soils; the weathering of TPH in soils; risk factors previously developed for neat petroleum products and four LCPHs; and on the toxicity of LCPHs. Oral reference doses were developed for nonane, decane, C10-C11 isoparaffmic hydrocarbon dearomatized white spirit C11 -C12, mineral oil, and petroleum wax. Gaps in the data necessary for the development of risk factors for LCPHs were identified and suggestions were made for future research to elucidate risk assessment at petroleum contamination sites. In addition, four DoD sites were identified for potential demonstration of risk assessment and risk-based cleanup versus cleanup based on regulatory standards for soils.

  1. ECERIFERUM2-LIKE Proteins Have Unique Biochemical and Physiological Functions in Very-Long-Chain Fatty Acid Elongation1[OPEN

    PubMed Central

    Haslam, Tegan M.; Haslam, Richard; Thoraval, Didier; Pascal, Stéphanie; Delude, Camille; Domergue, Frédéric; Fernández, Aurora Mañas; Beaudoin, Frédéric; Napier, Johnathan A.; Kunst, Ljerka; Joubès, Jérôme

    2015-01-01

    The extension of very-long-chain fatty acids (VLCFAs) for the synthesis of specialized apoplastic lipids requires unique biochemical machinery. Condensing enzymes catalyze the first reaction in fatty acid elongation and determine the chain length of fatty acids accepted and produced by the fatty acid elongation complex. Although necessary for the elongation of all VLCFAs, known condensing enzymes cannot efficiently synthesize VLCFAs longer than 28 carbons, despite the prevalence of C28 to C34 acyl lipids in cuticular wax and the pollen coat. The eceriferum2 (cer2) mutant of Arabidopsis (Arabidopsis thaliana) was previously shown to have a specific deficiency in cuticular waxes longer than 28 carbons, and heterologous expression of CER2 in yeast (Saccharomyces cerevisiae) demonstrated that it can modify the acyl chain length produced by a condensing enzyme from 28 to 30 carbon atoms. Here, we report the physiological functions and biochemical specificities of the CER2 homologs CER2-LIKE1 and CER2-LIKE2 by mutant analysis and heterologous expression in yeast. We demonstrate that all three CER2-LIKEs function with the same small subset of condensing enzymes, and that they have different effects on the substrate specificity of the same condensing enzyme. Finally, we show that the changes in acyl chain length caused by each CER2-LIKE protein are of substantial importance for cuticle formation and pollen coat function. PMID:25596184

  2. Tumor-suppressive functions of long-chain acyl-CoA synthetase 4 in gastric cancer.

    PubMed

    Ye, Xiaojuan; Zhang, Yi; Wang, Xiao; Li, Yandong; Gao, Yong

    2016-04-01

    Long chain acyl CoA synthetase 4 (ACSL4) is a key enzyme in fatty acid metabolism with marked preference for arachidonic acid (AA). Recent reports have implicated its crucial roles in tumorigenesis. However in gastric cancer (GC), the expression and function of ACSL4 remain unclear. In the present study, we identified ACSL4 as a potential tumor suppressor in GC. The ACSL4 expression in GC samples was evaluated by real-time PCR and immunohistochemistry. The results indicated that the mRNA and protein levels of ACSL4 were frequently downregulated in cancer tissues compared with the adjacent non-cancerous mucosa control tissues. Cell-based functional assays exhibited that ectopic expression of ACSL4 inhibits cell growth, colony formation and cell migration, whereas ACSL4 knockdown enhanced these effects. In a nude mice model, ACSL4 knockdown also promoted subcutaneous xenografts' growth in vivo. Moreover, western blot analysis revealed that ACSL4 expression had a significant effect on FAK and P21 protein level. These findings suggest that ACSL4 plays a tumor-suppressive role and could be a potential therapeutic target in GC. PMID:26949059

  3. Following the flux of long-chain bases through the sphingolipid pathway in vivo using mass spectrometry.

    PubMed

    Martínez-Montañés, Fernando; Schneiter, Roger

    2016-05-01

    Sphingolipids are essential components of the plasma membrane. Their synthesis is tightly controlled by regulatory proteins, which impinge on the rate-limiting step of the pathway, the condensation of serine and palmitoyl-CoA to long-chain base (LCB). The subsequent conversion of LCB to ceramide by ceramide synthase (CerS) is also tightly regulated, because both the accumulation of LCB as well as an excess of ceramide is toxic. Here we describe an in vivo assay to monitor the flux of LCB through the sphingolipid pathway in yeast. Cells are provided with nonnatural odd-chain sphingosine analogs, C17-dihydrosphingosine or C17-phytosphingosine (PHS), and their incorporation into ceramide and more complex sphingolipids is monitored by mass spectrometry. Incorporation of C17-PHS is time and concentration dependent, is inhibited by fumonisin B1, an inhibitor of CerS, and greatly reduced in double mutant cells lacking components of the CerS, Lac1 and Lag1. The resulting C17-ceramides are further metabolized to more complex sphingolipids, inositol phosphorylceramide and mannosylinositol phosphorylceramide), indicating that the tracer can be used to decipher the regulation of later steps of the pathway. In support of this notion, we show that mutants lacking the Orm proteins, regulators of the rate-limiting step of the pathway, display increased steady-state levels of these intermediates without affecting their rate of synthesis. PMID:26977056

  4. Surface active molecules: preparation and properties of long chain n-acyl-l-alpha-amino-omega-guanidine alkyl acid derivatives.

    PubMed

    Infante, R; Dominguez, J G; Erra, P; Julia, R; Prats, M

    1984-12-01

    Synopsis A new route for the synthesis of long chain N(alpha)-acyl-l-alpha-amino-omega-guamdine alkyl acid derivatives, with cationic or amphoteric character has been established. The general formula of these compounds is shown below. A physico-chemical and antimicrobial study of these products as a function of the alkyl ester or sodium salt (R), the straight chain length of the fatty acid residue (x) and the number of carbons between the omega-guanidine and omega-carboxyl group (n) has been investigated. The water solubility, surface tension, critical micelle concentration (c.m.c.) and minimum inhibitory concentration (MIC) against Gram-positive and Gram-negative bacteria (including Pseudomonas) has been determined. Dicyclohexylcarbodiimide has been used to condense fatty acids and alpha-amino-omega-guanidine alkyl acids. In these conditions protection of the omega-guanidine group is not necessary. The main characteristic of this synthetic procedure is the use of very mild experimental conditions (temperature, pH) to form the amide linkage which leads to pure optical compounds in high yield in the absence of electrolytes. The results show that some structural modifications, particularly the protection of the carboxyl group, promote variations of the surfactant and antimicrobial properties. Only those molecules with the blocked carboxyl group (cationic molecules, where R = Me, Et or Pr) showed a good surfactant and antimicrobial activity. When the carboxyl group was unprotected (amphoteric molecules, where R = Na(+)) the resulting compounds were inactive. PMID:19467126

  5. Role of perinatal long-chain omega-3 fatty acids in cortical circuit maturation: Mechanisms and implications for psychopathology.

    PubMed

    McNamara, Robert K; Vannest, Jennifer J; Valentine, Christina J

    2015-03-22

    Accumulating translational evidence suggests that the long-chain omega-3 fatty acid docosahexaenoic acid (DHA) plays a role in the maturation and stability of cortical circuits that are impaired in different recurrent psychiatric disorders. Specifically, rodent and cell culture studies find that DHA preferentially accumulates in synaptic and growth cone membranes and promotes neurite outgrowth, dendritic spine stability, and synaptogenesis. Additional evidence suggests that DHA may play a role in microglia-mediated synaptic pruning, as well as myelin development and resilience. In non-human primates n-3 fatty acid insufficiency during perinatal development leads to widespread deficits in functional connectivity in adult frontal cortical networks compared to primates raised on DHA-fortified diet. Preterm delivery in non-human primates and humans is associated with early deficits in cortical DHA accrual. Human preterm birth is associated with long-standing deficits in myelin integrity and cortical circuit connectivity and increased risk for attention deficit/hyperactivity disorder (ADHD), mood, and psychotic disorders. In general, ADHD and mood and psychotic disorders initially emerge during rapid periods of cortical circuit maturation and are characterized by DHA deficits, myelin pathology, and impaired cortical circuit connectivity. Together these associations suggest that early and uncorrected deficits in fetal brain DHA accrual may represent a modifiable risk factor for cortical circuit maturation deficits in psychiatric disorders, and could therefore have significant implications for informing early intervention and prevention strategies. PMID:25815252

  6. Meta-Analysis of Long-Chain Omega-3 Polyunsaturated Fatty Acids (LCω-3PUFA) and Prostate Cancer

    PubMed Central

    Alexander, Dominik D.; Bassett, Julie K.; Weed, Douglas L.; Barrett, Erin Cernkovich; Watson, Heather; Harris, William

    2015-01-01

    We conducted a systematic review and meta-analysis to estimate the potential association between LCω-3PUFAs and prostate cancer (PC). A comprehensive literature search was performed through 2013 to identify prospective studies that examined dietary intakes of long-chain omega-3 polyunsaturated fatty acids (LCω-3PUFA) or blood biomarkers of LCω-3PUFA status and risk of PC. Random-effects meta-analyses were conducted to generate summary relative risk estimates (SRREs) for LCω-3PUFAs and total PC, and by stage and grade. Subgroup analyses were also conducted for specific fatty acids and other study characteristics. Twelve self-reported dietary intake and 9 biomarker studies from independent study populations were included in the analysis, with 446,243 and 14,897 total participants, respectively. No association between LCω-3PUFAs and total PC was observed (SRRE = 1.00, 95% CI: 0.93–1.09) for the dietary intake studies (high vs. low LCω-3PUFAs category comparison) or for the biomarker studies (SRRE of 1.07, 95% CI: 0.94–1.20). In general, most summary associations for the dietary intake studies were in the inverse direction, whereas the majority of summary associations for the biomarker studies were in the positive direction, but all were weak in magnitude. The results from this meta-analysis do not support an association between LCω-3PUFAs and PC. PMID:25826711

  7. Interactions of a very long chain fatty acid with model membranes and serum albumin. Implications for the pathogenesis of adrenoleukodystrophy.

    PubMed Central

    Ho, J K; Moser, H; Kishimoto, Y; Hamilton, J A

    1995-01-01

    Adrenoleukodystrophy (ALD) is an inherited disorder of fatty acid metabolism marked by accumulation of very long chain saturated fatty acids (VLCFA), especially the 26-carbon acid, hexacosanoic acid (HA), in membranes and tissues. We have studied interactions of 13C-enriched HA with model membranes (phospholipid bilayer vesicles) and bovine serum albumin (BSA) by 13C NMR spectroscopy to compare properties of HA with those of typical dietary fatty acids. In phospholipid bilayers the carboxyl group of HA is localized in the aqueous interface, with an apparent pKa (7.4) similar to other fatty acids; the acyl chain must then penetrate very deeply into the membrane. Desorption of HA from vesicles (t1+2 = 3 h) is orders of magnitude slower than shorter chain fatty acids. In mixtures of vesicles and BSA, HA partitions much more favorably to phospholipid bilayers than typical fatty acids. BSA binds a maximum of only 1 mole of HA at one binding site. Calorimetric experiments show strong perturbations of acyl chains of phospholipids by HA. We predict that disruptive effects of VLCFA on cell membrane structure and function may explain the neurological manifestations of ALD patients. These effects will be further amplified by slow desorption of VLCFA from membranes and by the ineffective binding to serum albumin. PMID:7657817

  8. Altered Energetics of Exercise Explain Risk of Rhabdomyolysis in Very Long-Chain Acyl-CoA Dehydrogenase Deficiency

    PubMed Central

    Diekman, E. F.; Visser, G.; Schmitz, J. P. J.; Nievelstein, R. A. J.; de Sain-van der Velden, M.; Wardrop, M.; Van der Pol, W. L.; Houten, S. M.; van Riel, N. A. W.; Takken, T.; Jeneson, J. A. L.

    2016-01-01

    Rhabdomyolysis is common in very long-chain acyl-CoA dehydrogenase deficiency (VLCADD) and other metabolic myopathies, but its pathogenic basis is poorly understood. Here, we show that prolonged bicycling exercise against a standardized moderate workload in VLCADD patients is associated with threefold bigger changes in phosphocreatine (PCr) and inorganic phosphate (Pi) concentrations in quadriceps muscle and twofold lower changes in plasma acetyl-carnitine levels than in healthy subjects. This result is consistent with the hypothesis that muscle ATP homeostasis during exercise is compromised in VLCADD. However, the measured rates of PCr and Pi recovery post-exercise showed that the mitochondrial capacity for ATP synthesis in VLCADD muscle was normal. Mathematical modeling of oxidative ATP metabolism in muscle composed of three different fiber types indicated that the observed altered energy balance during submaximal exercise in VLCADD patients may be explained by a slow-to-fast shift in quadriceps fiber-type composition corresponding to 30% of the slow-twitch fiber-type pool in healthy quadriceps muscle. This study demonstrates for the first time that quadriceps energy balance during exercise in VLCADD patients is altered but not because of failing mitochondrial function. Our findings provide new clues to understanding the risk of rhabdomyolysis following exercise in human VLCADD. PMID:26881790

  9. Echium oil provides no benefit over linseed oil for (n-3) long-chain PUFA biosynthesis in rainbow trout.

    PubMed

    Cleveland, Benjamin J; Francis, David S; Turchini, Giovanni M

    2012-08-01

    The implementation of alternative lipid sources for use in aquaculture is of considerable interest globally. However, the possible benefit of using stearidonic acid (SDA)-rich fish oil (FO) alternatives has led to scientific confusion. Two hundred and forty rainbow trout (Oncorhynchus mykiss) were fed 1 of 4 diets (3 replicate tanks/treatment) containing either FO, linseed oil (LO), echium oil, or mixed vegetable oil (72% LO, 23% sunflower oil, and 6% canola oil) as the dietary lipid source (16.5%) for 73 d to investigate the competition and long-chain PUFA (LC-PUFA) biosynthesis between the fatty acid substrates α-linolenic acid (ALA) and SDA. SDA was more efficiently bioconverted to LC-PUFA compared with ALA. However, when the dietary lipid sources were directly compared, the increased provision of C18 PUFA within the LO diet resulted in no significant differences in (n-3) LC-PUFA content compared with fish fed the other diets. This study therefore shows that, rather than the previously speculated substrate competition, the limiting process in the apparent in vivo (n-3) LC-PUFA biosynthesis appears to be substrate availability. Rainbow trout fed the SDA- and ALA-rich dietary lipid sources subsequently had similar significant reductions in (n-3) LC-PUFA compared with fish fed the FO diet, therefore providing no additional dietary benefit on (n-3) LC-PUFA concentrations. PMID:22739372

  10. Fatty Acid Oxidation Mediated by Acyl-CoA Synthetase Long Chain 3 Is Required for Mutant KRAS Lung Tumorigenesis.

    PubMed

    Padanad, Mahesh S; Konstantinidou, Georgia; Venkateswaran, Niranjan; Melegari, Margherita; Rindhe, Smita; Mitsche, Matthew; Yang, Chendong; Batten, Kimberly; Huffman, Kenneth E; Liu, Jingwen; Tang, Ximing; Rodriguez-Canales, Jaime; Kalhor, Neda; Shay, Jerry W; Minna, John D; McDonald, Jeffrey; Wistuba, Ignacio I; DeBerardinis, Ralph J; Scaglioni, Pier Paolo

    2016-08-01

    KRAS is one of the most commonly mutated oncogenes in human cancer. Mutant KRAS aberrantly regulates metabolic networks. However, the contribution of cellular metabolism to mutant KRAS tumorigenesis is not completely understood. We report that mutant KRAS regulates intracellular fatty acid metabolism through Acyl-coenzyme A (CoA) synthetase long-chain family member 3 (ACSL3), which converts fatty acids into fatty Acyl-CoA esters, the substrates for lipid synthesis and β-oxidation. ACSL3 suppression is associated with depletion of cellular ATP and causes the death of lung cancer cells. Furthermore, mutant KRAS promotes the cellular uptake, retention, accumulation, and β-oxidation of fatty acids in lung cancer cells in an ACSL3-dependent manner. Finally, ACSL3 is essential for mutant KRAS lung cancer tumorigenesis in vivo and is highly expressed in human lung cancer. Our data demonstrate that mutant KRAS reprograms lipid homeostasis, establishing a metabolic requirement that could be exploited for therapeutic gain. PMID:27477280

  11. Shear-induced enhancements of crystallization kinetics and morphological transformation for long chain branched polylactides with different branching degrees

    PubMed Central

    Wang, Junyang; Bai, Jing; Zhang, Yaqiong; Fang, Huagao; Wang, Zhigang

    2016-01-01

    The effects of long chain branching (LCB) degree on the shear-induced isothermal crystallization kinetics of a series of LCB polylactides (LCB PLAs) have been investigated by using rotational rheometer, polarized optical microscopy (POM) and scanning electron microscopy (SEM). Dynamic viscoelastic properties obtained by small-amplitude oscillatory shear (SAOS) tests indicate that LCB PLAs show more broadened relaxation time spectra with increasing LCB degree. Upon a pre-shear at the shear rate of 1 s−1 LCB PLAs show much faster crystallization kinetics than linear PLA and the crystallization kinetics is enhanced with increasing LCB degree. By modeling the system as a suspension the quantitative evaluation of nucleation density can be derived from rheological experiments. The nucleation density is greatly enhanced with increasing LCB degree and a saturation in shear time is observed. Crystalline morphologies for LCB PLAs observed by POM and SEM demonstrate the enhancement of nucleation density with increasing LCB degree and a transformation from spherulitic to orientated crystalline morphologies. The observation can be ascribed to longer relaxation time of the longest macromolecular chains and broadened, complex relaxation behaviors due to the introduction of LCB into PLA, which is essential in stabilizing the orientated crystal nuclei after pre-shear. PMID:27246803

  12. Role of perinatal long-chain omega-3 fatty acids in cortical circuit maturation: Mechanisms and implications for psychopathology

    PubMed Central

    McNamara, Robert K; Vannest, Jennifer J; Valentine, Christina J

    2015-01-01

    Accumulating translational evidence suggests that the long-chain omega-3 fatty acid docosahexaenoic acid (DHA) plays a role in the maturation and stability of cortical circuits that are impaired in different recurrent psychiatric disorders. Specifically, rodent and cell culture studies find that DHA preferentially accumulates in synaptic and growth cone membranes and promotes neurite outgrowth, dendritic spine stability, and synaptogenesis. Additional evidence suggests that DHA may play a role in microglia-mediated synaptic pruning, as well as myelin development and resilience. In non-human primates n-3 fatty acid insufficiency during perinatal development leads to widespread deficits in functional connectivity in adult frontal cortical networks compared to primates raised on DHA-fortified diet. Preterm delivery in non-human primates and humans is associated with early deficits in cortical DHA accrual. Human preterm birth is associated with long-standing deficits in myelin integrity and cortical circuit connectivity and increased risk for attention deficit/hyperactivity disorder (ADHD), mood, and psychotic disorders. In general, ADHD and mood and psychotic disorders initially emerge during rapid periods of cortical circuit maturation and are characterized by DHA deficits, myelin pathology, and impaired cortical circuit connectivity. Together these associations suggest that early and uncorrected deficits in fetal brain DHA accrual may represent a modifiable risk factor for cortical circuit maturation deficits in psychiatric disorders, and could therefore have significant implications for informing early intervention and prevention strategies. PMID:25815252

  13. Glucose Regulates Hypothalamic Long-chain Fatty Acid Metabolism via AMP-activated Kinase (AMPK) in Neurons and Astrocytes*

    PubMed Central

    Taïb, Bouchra; Bouyakdan, Khalil; Hryhorczuk, Cécile; Rodaros, Demetra; Fulton, Stephanie; Alquier, Thierry

    2013-01-01

    Hypothalamic controls of energy balance rely on the detection of circulating nutrients such as glucose and long-chain fatty acids (LCFA) by the mediobasal hypothalamus (MBH). LCFA metabolism in the MBH plays a key role in the control of food intake and glucose homeostasis, yet it is not known if glucose regulates LCFA oxidation and esterification in the MBH and, if so, which hypothalamic cell type(s) and intracellular signaling mechanisms are involved. The aim of this study was to determine the impact of glucose on LCFA metabolism, assess the role of AMP-activated Kinase (AMPK), and to establish if changes in LCFA metabolism and its regulation by glucose vary as a function of the kind of LCFA, cell type, and brain region. We show that glucose inhibits palmitate oxidation via AMPK in hypothalamic neuronal cell lines, primary hypothalamic astrocyte cultures, and MBH slices ex vivo but not in cortical astrocytes and slice preparations. In contrast, oleate oxidation was not affected by glucose or AMPK inhibition in MBH slices. In addition, our results show that glucose increases palmitate, but not oleate, esterification into neutral lipids in neurons and MBH slices but not in hypothalamic astrocytes. These findings reveal for the first time the metabolic fate of different LCFA in the MBH, demonstrate AMPK-dependent glucose regulation of LCFA oxidation in both astrocytes and neurons, and establish metabolic coupling of glucose and LCFA as a distinguishing feature of hypothalamic nuclei critical for the control of energy balance. PMID:24240094

  14. Heterotrophic Production of Omega-3 Long-Chain Polyunsaturated Fatty Acids by Trophically Converted Marine Diatom Phaeodactylum tricornutum

    PubMed Central

    Hamilton, Mary L.; Powers, Stephen; Napier, Johnathan A.; Sayanova, Olga

    2016-01-01

    We have created via metabolic engineering a heterotrophic strain of Phaeodactylum tricornutum that accumulates enhanced levels of the high value omega-3 long chain polyunsaturated fatty acid (LC-PUFAs) docosahexaenoic acid (DHA). This was achieved by generation of transgenic strains in which the Δ5-elongase from Ostreococcus tauri was co-expressed with a glucose transporter from the moss Physcomitrella patens. This double transformant has the capacity to grow in the dark in liquid medium supplemented with glucose and accumulate substantial levels of omega-3 LC-PUFAs. The effects of glucose concentrations on growth and LC-PUFA production of wild type and transformed strains cultivated in the light and dark were studied. The highest omega-3 LC-PUFAs accumulation was observed in cultures grown under mixotrophic conditions in the presence of 1% glucose (up to 32.2% of total fatty acids, TFA). Both DHA and EPA are detected at high levels in the neutral lipids of transgenic cells grown under phototrophic conditions, averaging 36.5% and 23.6% of TFA, respectively. This study demonstrates the potential for P. tricornutum to be developed as a viable commercial strain for both EPA and DHA production under mixo- and heterotrophic conditions. PMID:27005636

  15. Specific and differential inhibition of very-long-chain fatty acid elongases from Arabidopsis thaliana by different herbicides

    PubMed Central

    Trenkamp, Sandra; Martin, William; Tietjen, Klaus

    2004-01-01

    In higher plants, very-long-chain fatty acids (VLCFAs) are the main constituents of hydrophobic polymers that prevent dessication at the leaf surface and provide stability to pollen grains. Of the 21 genes encoding VLCFA elongases (VLCFAEs) from Arabidopsis thaliana, 17 were expressed heterologously in Saccharomyces cerevisiae. Six VLCFAEs, including three known elongases (FAE1, KCS1, and KCS2) and three previously uncharacterized gene products (encoded by At5g43760, At1g04220, and At1g25450) were found to be enzymatically active with endogenous yeast fatty acid substrates and to some extent with externally supplied unsaturated substrates. The spectrum of VLCFAs accumulated in expressing yeast strains was determined by gas chromatography/mass spectrometry. Marked specificity was found among elongases tested with respect to their elongation products, which encompassed saturated and monounsaturated fatty acids 20–30 carbon atoms in length. The active VLCFAEs revealed highly distinct patterns of differential sensitivity to oxyacetamides, chloroacetanilides, and other compounds tested, whereas yeast endogenous VLCFA production, which involves its unrelated elongase (ELO) in sphingolipid synthesis, was unaffected. Several compounds inhibited more than one VLCFAE, and some inhibited all six active enzymes. These findings pinpoint VLCFAEs as the target of the widely used K3 class herbicides, which have been in commercial use for 50 years, provide important clues as to why spontaneous resistance to this class is rare, and point to complex patterns of substrate specificity and product spectrum among members of the Arabidopsis VLCFAE family. PMID:15277688

  16. Medium and Long Chain Fatty Acids Differentially Modulate Apoptosis and Release of Inflammatory Cytokines in Human Liver Cells.

    PubMed

    Li, Lumin; Wang, Baogui; Yu, Ping; Wen, Xuefang; Gong, Deming; Zeng, Zheling

    2016-06-01

    Medium chain fatty acids (MCFA) can be more easily absorbed and supply energy more rapidly than long chain fatty acids (LCFA). However, little is known about the inflammatory response by the treatment of MCFA in human liver cells. Thus this study used human liver cells (LO2) to evaluate the effects of MCFA on apoptosis and inflammatory response. Tetrazolim-based colorimetric assay and lactate dehydrogenase assay were used to measure the viability of LO2 cells, isolated spleens and liver cells from BALB/C mice. Inverted fluorescence microscopy and flow cytometry were used to assess the cell apoptosis. Activity of superoxide dismutase and malondialdehyde level were measured to determine the oxidative damage. mRNA or protein levels of classical pro-inflammatory cytokines were analyzed by quantitative real-time polymerase chain reaction (qPCR), enzyme-linked immunosorbent assay and western blotting. The results showed that the liver cells treated with the fatty acids at 200 μM for 24 h exhibited good viability. Fatty acids induced inflammatory cytokines at transcriptional and translational levels to a lesser extent than lipopolysaccharide. LCFA (oleic acid) up-regulated tumor necrosis fator-α, monocyte chemoattractant-1 and interleukin-1β while down-regulated IL-6 and IL-8 secretion to a higher extent than MCFA in mRNA and protein levels. These findings suggested that MCFA may induce apoptosis to a less extent and exert more gentle inflammation than LCFA in human liver cells. PMID:27145239

  17. The chloroplast membrane associated ceQORH putative quinone oxidoreductase reduces long-chain, stress-related oxidized lipids.

    PubMed

    Curien, Gilles; Giustini, Cécile; Montillet, Jean-Luc; Mas-Y-Mas, Sarah; Cobessi, David; Ferrer, Jean-Luc; Matringe, Michel; Grechkin, Alexander; Rolland, Norbert

    2016-02-01

    Under oxidative stress conditions the lipid constituents of cells can undergo oxidation whose frequent consequence is the production of highly reactive α,β-unsaturated carbonyls. These molecules are toxic because they can add to biomolecules (such as proteins and nucleic acids) and several enzyme activities cooperate to eliminate these reactive electrophile species. CeQORH (chloroplast envelope Quinone Oxidoreductase Homolog, At4g13010) is associated with the inner membrane of the chloroplast envelope and imported into the organelle by an alternative import pathway. In the present study, we show that the recombinant ceQORH exhibits the activity of a NADPH-dependent α,β-unsaturated oxoene reductase reducing the double bond of medium-chain (C⩾9) to long-chain (18 carbon atoms) reactive electrophile species deriving from poly-unsaturated fatty acid peroxides. The best substrates of ceQORH are 13-lipoxygenase-derived γ-ketols. γ-Ketols are spontaneously produced in the chloroplast from the unstable allene oxide formed in the biochemical pathway leading to 12-oxo-phytodienoic acid, a precursor of the defense hormone jasmonate. In chloroplasts, ceQORH could detoxify 13-lipoxygenase-derived γ-ketols at their production sites in the membranes. This finding opens new routes toward the understanding of γ-ketols role and detoxification. PMID:26678323

  18. Long Chain Fatty Acid Acylated Derivatives of Quercetin-3-O-Glucoside as Antioxidants to Prevent Lipid Oxidation

    PubMed Central

    Warnakulasuriya, Sumudu N.; Ziaullah; Rupasinghe, H.P. Vasantha

    2014-01-01

    Flavonoids have shown promise as natural plant-based antioxidants for protecting lipids from oxidation. It was hypothesized that their applications in lipophilic food systems can be further enhanced by esterification of flavonoids with fatty acids. Quercetin-3-O-glucoside (Q3G) was esterified individually with six selected long chain fatty acids: stearic acid (STA), oleic acid (OLA), linoleic acid (LNA), α-linolenic acid (ALA), eicosapentaenoic acid (EPA) and decosahexaenoic acid (DHA), using Candida antarctica B lipase as the biocatalyst. The antioxidant activity of esterified flavonoids was evaluated using lipid oxidation model systems of poly-unsaturated fatty acids-rich fish oil and human low density lipoprotein (LDL), in vitro. In the oil-in-water emulsion, Q3G esters exhibited 50% to 100% inhibition in primary oxidation and 30% to 75% inhibition in secondary oxidation. In bulk oil, Q3G esters did not provide considerable protection from lipid oxidation; however, Q3G demonstrated more than 50% inhibition in primary oxidation. EPA, DHA and ALA esters of Q3G showed significantly higher inhibition in Cu2+- and peroxyl radical-induced LDL oxidation in comparison to Q3G. PMID:25384198

  19. Identification and quantification of triacylglycerols containing n-3 long-chain polyunsaturated fatty acids in bovine milk.

    PubMed

    Liu, Zhiqian; Moate, Peter; Ezerniks, Vilnis; Cocks, Benjamin G; Rochfort, Simone

    2015-12-01

    The n-3 long-chain polyunsaturated fatty acids (LC-PUFA) are low-abundance components in milk fat, but have great potential in promoting human health. A comprehensive survey on triacylglycerol (TAG) molecular species in milk that contain at least one type of n-3 LC-PUFA, namely eicosapentaenoic acid, docosahexaenoic acid, and docosapentaenoic acid, was conducted in this work using HPLC-linear trap quadrupole-Orbitrap and HPLC-triple quadrupole mass spectrometry techniques. A total of 51 TAG species that contain n-3 LC-PUFA have been identified in bovine milk and their structures assigned. The TAG species containing docosahexaenoic acid were found in much smaller number and at much lower abundance compared with the other 2 types of TAG. An HPLC-triple quadrupole mass spectrometry-based method was developed, which provides relative quantification of all these TAG species in a run of 36 min. Application of this method to the quantification of n-3 LC-PUFA-incorporated TAG in 32 individual animal milk samples allowed us to determine variation between animals, identify strong metabolic relationships between TAG species, and reveal negative effect of a grape marc supplement on the accumulation of eicosapentaenoic acid in milk. PMID:26476942

  20. Coexpression of multiple genes reconstitutes two pathways of very long-chain polyunsaturated fatty acid biosynthesis in Pichia pastoris.

    PubMed

    Kim, Sun Hee; Roh, Kyung Hee; Kim, Kwang-Soo; Kim, Hyun Uk; Lee, Kyeong-Ryeol; Kang, Han-Chul; Kim, Jong-Bum

    2014-09-01

    The introduction of novel traits to cells often requires the stable coexpression of multiple genes within the same cell. Herein, we report that C22 very long-chain polyunsaturated fatty acids (VLC-PUFAs) were synthesized from C18 precursors by reactions catalyzed by delta 6-desaturase, an ELOVL5 involved in VLC-PUFA elongation, and delta 5-desaturase. The coexpression of McD6DES, AsELOVL5, and PtD5DES encoding the corresponding enzymes, produced docosatetraenoic acid (C22:4 n-6) and docosapentaenoic acid (C22:5 n-3), as well as arachidonic acid (C20:4 n-6) and eicosapentaenoic acid (C20:5 n-3) in the methylotrophic yeast Pichia pastoris. The expression of each gene increased within 24 h, with high transcript levels after induction with 0.5 or 1 % methanol. High levels of the newly expressed VLC-PUFAs occurred after 144 h. This expression system exemplifies the recent progress and future possibilities of the metabolic engineering of VLC-PUFAs in oilseed crops. PMID:24863294

  1. Elevation of 20-carbon long chain bases due to a mutation in serine palmitoyltransferase small subunit b results in neurodegeneration

    PubMed Central

    Zhao, Lihong; Spassieva, Stefka; Gable, Kenneth; Gupta, Sita D.; Shi, Lan-Ying; Wang, Jieping; Bielawski, Jacek; Hicks, Wanda L.; Krebs, Mark P.; Naggert, Juergen; Hannun, Yusuf A.; Dunn, Teresa M.; Nishina, Patsy M.

    2015-01-01

    Sphingolipids typically have an 18-carbon (C18) sphingoid long chain base (LCB) backbone. Although sphingolipids with LCBs of other chain lengths have been identified, the functional significance of these low-abundance sphingolipids is unknown. The LCB chain length is determined by serine palmitoyltransferase (SPT) isoenzymes, which are trimeric proteins composed of two large subunits (SPTLC1 and SPTLC2 or SPTLC3) and a small subunit (SPTssa or SPTssb). Here we report the identification of an Sptssb mutation, Stellar (Stl), which increased the SPT affinity toward the C18 fatty acyl-CoA substrate by twofold and significantly elevated 20-carbon (C20) LCB production in the mutant mouse brain and eye, resulting in surprising neurodegenerative effects including aberrant membrane structures, accumulation of ubiquitinated proteins on membranes, and axon degeneration. Our work demonstrates that SPT small subunits play a major role in controlling SPT activity and substrate affinity, and in specifying sphingolipid LCB chain length in vivo. Moreover, our studies also suggest that excessive C20 LCBs or C20 LCB-containing sphingolipids impair protein homeostasis and neural functions. PMID:26438849

  2. Improving rheology and enzymatic hydrolysis of high-solid corncob slurries by adding lignosulfonate and long-chain fatty alcohols.

    PubMed

    Lou, Hongming; Wu, Shun; Li, Xiuli; Lan, Tianqing; Yang, Dongjie; Pang, Yuxia; Qiu, Xueqing; Li, Xuehui; Huang, Jinhao

    2014-08-20

    The effects of lignosulfonate (SXSL) and long-chain fatty alcohols (LFAs) on the rheology and enzymatic hydrolysis of high-solid corncob slurries were investigated. The application of 2.5% (w/w) SXSL increased the substrate enzymatic digestibility (SED) of high-solid corncob slurries at 72 h from 31.7 to 54.0%, but meanwhile it increased the slurry's yield stress and complex viscosity to make the slurry difficult to stir and pump. The smallest molecular weight (MW) SXSL fraction had the strongest enhancement on SED. The SXSL fraction with large MW had a negative effect on rheology. n-Octanol (C8) and n-decanol (C10) improved the rheological properties of high-solid slurry and are strong enough to counteract the negative effect of SXSL. Furthermore, C8 and C10 clearly enhanced the enzymatic hydrolysis of high-solid corncob slurries with and without SXSL. A mechanism was proposed to explain the observed negative effect of SXSL and the positive effect of LFAs on the rheological properties. PMID:25111907

  3. Short-Term Long Chain Omega3 Diet Protects from Neuroinflammatory Processes and Memory Impairment in Aged Mice

    PubMed Central

    Joffre, Corinne; Costes, Laurence; Aubert, Agnès; Grégoire, Stéphane; Bretillon, Lionel; Layé, Sophie

    2012-01-01

    Regular consumption of food enriched in omega3 polyunsaturated fatty acids (ω3 PUFAs) has been shown to reduce risk of cognitive decline in elderly, and possibly development of Alzheimer's disease. Docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) are the most likely active components of ω3-rich PUFAs diets in the brain. We therefore hypothesized that exposing mice to a DHA and EPA enriched diet may reduce neuroinflammation and protect against memory impairment in aged mice. For this purpose, mice were exposed to a control diet throughout life and were further submitted to a diet enriched in EPA and DHA during 2 additional months. Cytokine expression together with a thorough analysis of astrocytes morphology assessed by a 3D reconstruction was measured in the hippocampus of young (3-month-old) and aged (22-month-old) mice. In addition, the effects of EPA and DHA on spatial memory and associated Fos activation in the hippocampus were assessed. We showed that a 2-month EPA/DHA treatment increased these long-chain ω3 PUFAs in the brain, prevented cytokines expression and astrocytes morphology changes in the hippocampus and restored spatial memory deficits and Fos-associated activation in the hippocampus of aged mice. Collectively, these data indicated that diet-induced accumulation of EPA and DHA in the brain protects against neuroinflammation and cognitive impairment linked to aging, further reinforcing the idea that increased EPA and DHA intake may provide protection to the brain of aged subjects. PMID:22662127

  4. Crystal structure of Pseudomonas fluorescens mannitol 2-dehydrogenase: evidence for a very divergent long-chain dehydrogenase family.

    PubMed

    Kavanagh, Kathryn L; Klimacek, Mario; Nidetzky, Bernd; Wilson, David K

    2003-02-01

    Mannitol 2-dehydrogenase from Pseudomonas fluorescens (pfMDH) is a secondary alcohol dehydrogenase that catalyzes the reversible NAD(P)-dependent oxidation of D-mannitol to D-fructose, D-arabinitol to D-xylulose, and D-sorbitol to L-sorbose. It is a member of the mostly prokaryotic family of long-chain mannitol dehydrogenases that so far includes 66 members. Unlike other alcohol and polyol dehydrogenases that utilize metal cofactors or a conserved active-site tyrosine for catalysis, an invariant lysine is the general base. The crystal structure of pfMDH in a binary complex with NAD(H) and a ternary complex with NAD(H) and D-mannitol have been determined to 1.7 and 1.8 A resolution respectively. Comparison of secondary structure assignment to sequence alignments suggest the shortest members of this family, mannitol-1-phosphate 5-dehydrogenases, retain core elements but lack secondary structural components found on the surface of pfMDH. The elements predicted to be absent are distributed throughout the primary sequence, implying that a simple truncation or fusion did not occur. The closest structural neighbors are 6-phosphogluconate dehydrogenase, UDP-glucose dehydrogenase, N-(1-D-carboxyethyl)-L-norvaline dehydrogenase, and glycerol-3-phosphate dehydrogenase. Although sequence identity is only a barely recognizable 7-10%, conservation of secondary structural elements as well as homologous residues that are contributed to the active site indicates they may be related by divergent evolution. PMID:12604241

  5. Impact of sustainable feeds on omega-3 long-chain fatty acid levels in farmed Atlantic salmon, 2006-2015.

    PubMed

    Sprague, M; Dick, J R; Tocher, D R

    2016-01-01

    As the global population and its demand for seafood increases more of our fish will come from aquaculture. Farmed Atlantic salmon are a global commodity and, as an oily fish, contain a rich source of the health promoting long-chain omega-3 fatty acids, eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids. Replacing the traditional finite marine ingredients, fishmeal and fish oil, in farmed salmon diets with sustainable alternatives of terrestrial origin, devoid of EPA and DHA, presents a significant challenge for the aquaculture industry. By comparing the fatty acid composition of over 3,000 Scottish Atlantic salmon farmed between 2006 and 2015, we find that terrestrial fatty acids have significantly increased alongside a decrease in EPA and DHA levels. Consequently, the nutritional value of the final product is compromised requiring double portion sizes, as compared to 2006, in order to satisfy recommended EPA + DHA intake levels endorsed by health advisory organisations. Nevertheless, farmed Scottish salmon still delivers more EPA + DHA than most other fish species and all terrestrial livestock. Our findings highlight the global shortfall of EPA and DHA and the implications this has for the human consumer and examines the potential of microalgae and genetically modified crops as future sources of these important fatty acids. PMID:26899924

  6. Heterotrophic Production of Omega-3 Long-Chain Polyunsaturated Fatty Acids by Trophically Converted Marine Diatom Phaeodactylum tricornutum.

    PubMed

    Hamilton, Mary L; Powers, Stephen; Napier, Johnathan A; Sayanova, Olga

    2016-03-01

    We have created via metabolic engineering a heterotrophic strain of Phaeodactylum tricornutum that accumulates enhanced levels of the high value omega-3 long chain polyunsaturated fatty acid (LC-PUFAs) docosahexaenoic acid (DHA). This was achieved by generation of transgenic strains in which the Δ5-elongase from Ostreococcus tauri was co-expressed with a glucose transporter from the moss Physcomitrella patens. This double transformant has the capacity to grow in the dark in liquid medium supplemented with glucose and accumulate substantial levels of omega-3 LC-PUFAs. The effects of glucose concentrations on growth and LC-PUFA production of wild type and transformed strains cultivated in the light and dark were studied. The highest omega-3 LC-PUFAs accumulation was observed in cultures grown under mixotrophic conditions in the presence of 1% glucose (up to 32.2% of total fatty acids, TFA). Both DHA and EPA are detected at high levels in the neutral lipids of transgenic cells grown under phototrophic conditions, averaging 36.5% and 23.6% of TFA, respectively. This study demonstrates the potential for P. tricornutum to be developed as a viable commercial strain for both EPA and DHA production under mixo- and heterotrophic conditions. PMID:27005636

  7. Unsaturated Long Chain Free Fatty Acids Are Input Signals of the Salmonella enterica PhoP/PhoQ Regulatory System*

    PubMed Central

    Viarengo, Gastón; Sciara, Mariela I.; Salazar, Mario O.; Kieffer, Pablo M.; Furlán, Ricardo L. E.; García Véscovi, Eleonora

    2013-01-01

    The Salmonella enterica serovar Typhimurium PhoP/PhoQ system has largely been studied as a paradigmatic two-component regulatory system not only to dissect structural and functional aspects of signal transduction in bacteria but also to gain knowledge about the versatile devices that have evolved allowing a pathogenic bacterium to adjust to or counteract environmental stressful conditions along its life cycle. Mg2+ limitation, acidic pH, and the presence of cationic antimicrobial peptides have been identified as cues that the sensor protein PhoQ can monitor to reprogram Salmonella gene expression to cope with extra- or intracellular challenging conditions. In this work, we show for the first time that long chain unsaturated free fatty acids (LCUFAs) present in Salmonella growth medium are signals specifically detected by PhoQ. We demonstrate that LCUFAs inhibit PhoQ autokinase activity, turning off the expression of the PhoP-dependent regulon. We also show that LCUFAs exert their action independently of their cellular uptake and metabolic utilization by means of the β-oxidative pathway. Our findings put forth the complexity of input signals that can converge to finely tune the activity of the PhoP/PhoQ system. In addition, they provide a new potential biochemical platform for the development of antibacterial strategies to fight against Salmonella infections. PMID:23782700

  8. Atypical surface behavior of ceramides with nonhydroxy and 2-hydroxy very long-chain (C28-C32) PUFAs.

    PubMed

    Peñalva, Daniel A; Oresti, Gerardo M; Dupuy, Fernando; Antollini, Silvia S; Maggio, Bruno; Aveldaño, Marta I; Fanani, María L

    2014-03-01

    Unique species of ceramide (Cer) with very-long-chain polyunsaturated fatty acid (VLCPUFA), mainly 28-32 carbon atoms, 4-5 double bonds, in nonhydroxy and 2-hydroxy forms (n-V Cer and h-V Cer, respectively), are generated in rat spermatozoa from the corresponding sphingomyelins during the acrosomal reaction. The aim of this study was to determine the properties of these sperm-distinctive ceramides in Langmuir monolayers. Individual Cer species were isolated by HPLC and subjected to analysis of surface pressure, surface potential, and Brewster angle microscopy (BAM) as a function of molecular packing. In comparison with known species of Cer, n-V Cer and h-V Cer species showed much larger mean molecular areas and increased molecular dipole moments in liquid expanded phases, which suggest bending and partial hydration of the double bonded portion of the VLCPUFA. The presence of the 2-hydoxyl group induced a closer molecular packing in h-V Cer than in their chain-matched n-V Cer. In addition, all these Cer species showed liquid-expanded to liquid-condensed transitions at room temperature. Existence of domain segregation was confirmed by BAM. Additionally, thermodynamic analysis suggests a phase transition close to the physiological temperature for VLCPUFA-Cers if organized as bulk dispersions. PMID:24315999

  9. A novel enzyme-linked immunosorbent assay for ethynylestradiol using a long-chain biotinylated EE2 derivative.

    PubMed

    Schneider, Christian; Schöler, Heinz F; Schneider, Rudolf J

    2004-04-01

    Ethynylestradiol (EE2) is one of the most potent endocrine disrupting compounds capable to induce estrogenic effects even at trace level concentrations in the aquatic environment. Methods for detecting EE2 in such concentrations are generally based on GC or HPLC coupled to at least one mass spectrometer. Another approach are immunoassays and sensor systems but for most designs, derivatives of EE2 are required (e.g. for coupling to carrier proteins, enzyme or fluorescent labels, etc.). Here we present the straightforward synthesis and complete characterization of a new long-chain biotinylated EE2 derivative. The new EE2 derivative is used as tracer in a direct competitive enzyme-linked immunosorbent assay (ELISA) for the determination of EE2. With pure water, the limit of detection (LOD, signal-to-noise ratio, S/N = 3) and the test midpoint were found to be 14 and 136 ng l(-1), respectively. Cross reactivity (CR) was tested for 10 endogenous steroids and the BSA-conjugate used for immunization, as well as a synthetic precursor of the conjugate. Among the naturally occurring compounds, CR was determined to be maximum for metabolites of EE2 conjugated at ring-position 3 (17% and 37% for 3-glucuronide and 3-sulphate, respectively). Assay stability was tested against humic substances and organic solvents. Increasing amounts of organic solvents in the sample caused a clear decrease in sensitivity, presence of humic substances lead to an overestimation of EE2. PMID:15183690

  10. Long-chain acyl-CoA synthetase in fatty acid metabolism involved in liver and other diseases: An update

    PubMed Central

    Yan, Sheng; Yang, Xue-Feng; Liu, Hao-Lei; Fu, Nian; Ouyang, Yan; Qing, Kai

    2015-01-01

    Long-chain acyl-CoA synthetase (ACSL) family members include five different ACSL isoforms, each encoded by a separate gene and have multiple spliced variants. ACSLs on endoplasmic reticulum and mitochondrial outer membrance catalyze fatty acids with chain lengths from 12 to 20 carbon atoms to form acyl-CoAs, which are lipid metabolic intermediates and involved in fatty acid metabolism, membrane modifications and various physiological processes. Gain- or loss-of-function studies have shown that the expression of individual ACSL isoforms can alter the distribution and amount of intracellular fatty acids. Changes in the types and amounts of fatty acids, in turn, can alter the expression of intracellular ACSLs. ACSL family members affect not only the proliferation of normal cells, but the proliferation of malignant tumor cells. They also regulate cell apoptosis through different signaling pathways and molecular mechanisms. ACSL members have individual functions in fatty acid metabolism in different types of cells depending on substrate preferences, subcellular location and tissue specificity, thus contributing to liver diseases and metabolic diseases, such as fatty liver disease, obesity, atherosclerosis and diabetes. They are also linked to neurological disorders and other diseases. However, the mechanisms are unclear. This review addresses new findings in the classification and properties of ACSLs and the fatty acid metabolism-associated effects of ACSLs in diseases. PMID:25834313

  11. Hepatic long-chain acyl-CoA synthetase 5 mediates fatty acid channeling between anabolic and catabolic pathways.

    PubMed

    Bu, So Young; Mashek, Douglas G

    2010-11-01

    Long-chain acyl-CoA synthetases (ACSLs) and fatty acid transport proteins (FATPs) activate fatty acids (FAs) to acyl-CoAs prior to their downstream metabolism. Of numerous ACSL and FATP isoforms, ACSL5 is expressed predominantly in tissues with high rates of triacylglycerol (TAG) synthesis, suggesting it may have an anabolic role in lipid metabolism. To characterize the role of ACSL5 in hepatic energy metabolism, we used small interference RNA (siRNA) to knock down ACSL5 in rat primary hepatocytes. Compared with cells transfected with control siRNA, suppression of ACSL5 expression significantly decreased FA-induced lipid droplet formation. These findings were further extended with metabolic labeling studies showing that ACSL5 knockdown resulted in decreased [1-(14)C]oleic acid or acetic acid incorporation into intracellular TAG, phospholipids, and cholesterol esters without altering FA uptake or lipogenic gene expression. ACSL5 knockdown also decreased hepatic TAG secretion proportionate to the observed decrease in neutral lipid synthesis. ACSL5 knockdown did not alter lipid turnover or mediate the effects of insulin on lipid metabolism. Hepatocytes treated with ACSL5 siRNA had increased rates of FA oxidation without changing PPAR-α activity and target gene expression. These results suggest that ACSL5 activates and channels FAs toward anabolic pathways and, therefore, is an important branch point in hepatic FA metabolism. PMID:20798351

  12. Fluorinated alternatives to long-chain perfluoroalkyl carboxylic acids (PFCAs), perfluoroalkane sulfonic acids (PFSAs) and their potential precursors.

    PubMed

    Wang, Zhanyun; Cousins, Ian T; Scheringer, Martin; Hungerbühler, Konrad

    2013-10-01

    Since 2000 there has been an on-going industrial transition to replace long-chain perfluoroalkyl carboxylic acids(PFCAs), perfluoroalkane sulfonic acids (PFSAs) and their precursors. To date, information on these replacements including their chemical identities, however, has not been published or made easily accessible to the public, hampering risk assessment and management of these chemicals. Here we review information on fluorinated alternatives in the public domain. We identify over 20 fluorinated substances that are applied in [i] fluoropolymer manufacture, [ii] surface treatment of textile, leather and carpets, [iii] surface treatment of food contact materials,[iv] metal plating, [v] fire-fighting foams, and [vi] other commercial and consumer products.We summarize current knowledge on their environmental releases, persistence, and exposure of biota and humans. Based on the limited information available, it is unclear whether fluorinated alternatives are safe for humans and the environment.We identify three major data gaps that must be filled to perform meaningful risk assessments and recommend generation of the missing data through cooperation among all stakeholders (industry, regulators, academic scientists and the public). PMID:24660230

  13. Specificity of 1-triacontanol as a plant growth stimulator and inhibition of its effect by other long-chain compounds.

    PubMed

    Jones, J; Wert, V; Ries, S

    1979-01-01

    The effect of several analogs of 1-triacontanol (TRIA), differing in C-chain length (16-32), the position of the hydroxyl group and the terminal functional group, were tested alone and in combination with TRIA on the growth of rice (Oryza sativa L.), maize (Zea mays L.) and tomato (Lycopersicon esculentum Mill.) seedlings. Applied alone, none of the compounds caused an increase in growth; thus, chain length (30 C) and presence and position (terminal) of the hydroxyl group appear to be specific for the growth-promoting activity of TRIA. When applied simultaneously with TRIA, all analogs inhibited the response to the latter in all three test plants, whether applied in the nutrient solution, as foliar spray or by seed soaking. 1-Octacosanol inhibited the response of rice seedlings to 2.3 x 10(-8) M TRIA at concentrations as low as 2.4 x 10(-12) M. Thus preparations of TRIA and application equipment must be free from trace amounts of other long-chain compounds if they are to be used to increase plant growth. PMID:24407259

  14. Structural advantage of sugar beet α-glucosidase to stabilize the Michaelis complex with long-chain substrate.

    PubMed

    Tagami, Takayoshi; Yamashita, Keitaro; Okuyama, Masayuki; Mori, Haruhide; Yao, Min; Kimura, Atsuo

    2015-01-16

    The α-glucosidase from sugar beet (SBG) is an exo-type glycosidase. The enzyme has a pocket-shaped active site, but efficiently hydrolyzes longer maltooligosaccharides and soluble starch due to lower Km and higher kcat/Km for such substrates. To obtain structural insights into the mechanism governing its unique substrate specificity, a series of acarviosyl-maltooligosaccharides was employed for steady-state kinetic and structural analyses. The acarviosyl-maltooligosaccharides have a longer maltooligosaccharide moiety compared with the maltose moiety of acarbose, which is known to be the transition state analog of α-glycosidases. The clear correlation obtained between log Ki of the acarviosyl-maltooligosaccharides and log(Km/kcat) for hydrolysis of maltooligosaccharides suggests that the acarviosyl-maltooligosaccharides are transition state mimics. The crystal structure of the enzyme bound with acarviosyl-maltohexaose reveals that substrate binding at a distance from the active site is maintained largely by van der Waals interactions, with the four glucose residues at the reducing terminus of acarviosyl-maltohexaose retaining a left-handed single-helical conformation, as also observed in cycloamyloses and single helical V-amyloses. The kinetic behavior and structural features suggest that the subsite structure suitable for the stable conformation of amylose lowers the Km for long-chain substrates, which in turn is responsible for higher specificity of the longer substrates. PMID:25451917

  15. Impact of sustainable feeds on omega-3 long-chain fatty acid levels in farmed Atlantic salmon, 2006–2015

    PubMed Central

    Sprague, M.; Dick, J.R.; Tocher, D.R.

    2016-01-01

    As the global population and its demand for seafood increases more of our fish will come from aquaculture. Farmed Atlantic salmon are a global commodity and, as an oily fish, contain a rich source of the health promoting long-chain omega-3 fatty acids, eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids. Replacing the traditional finite marine ingredients, fishmeal and fish oil, in farmed salmon diets with sustainable alternatives of terrestrial origin, devoid of EPA and DHA, presents a significant challenge for the aquaculture industry. By comparing the fatty acid composition of over 3,000 Scottish Atlantic salmon farmed between 2006 and 2015, we find that terrestrial fatty acids have significantly increased alongside a decrease in EPA and DHA levels. Consequently, the nutritional value of the final product is compromised requiring double portion sizes, as compared to 2006, in order to satisfy recommended EPA + DHA intake levels endorsed by health advisory organisations. Nevertheless, farmed Scottish salmon still delivers more EPA + DHA than most other fish species and all terrestrial livestock. Our findings highlight the global shortfall of EPA and DHA and the implications this has for the human consumer and examines the potential of microalgae and genetically modified crops as future sources of these important fatty acids. PMID:26899924

  16. Competitive effects of long-chain-triglyceride emulsion on the metabolism of medium-chain-triglyceride emulsions.

    PubMed

    Cotter, R; Johnson, R C; Young, S K; Lin, L I; Rowe, W B

    1989-10-01

    This study was conducted to assess the potential metabolic competitive interactions of intravenous medium-chain-triglyceride (MCT) and long-chain-triglyceride (LCT) lipid emulsions. To assess this competition increasing concentrations of LCT emulsion were added to an intravenous dose of MCT emulsion of 3.0 g/kg body wt up to a maximum dose of 3.0 g LCTs/kg body wt. Blood samples were assessed for competitive interactions by analyzing the following metabolites: glucose, insulin, lactate, pyruvate, ketones (acetoacetate, beta-hydroxybutyrate), elimination of triglycerides, and free fatty acids. Evaluation of the data showed a strong competitive interaction between the MCT and LCT emulsions. This competition was evident as soon as LCTs were added to the MCT infusions and appeared to favor LCTs for removal and metabolism over MCTs. This appears to indicate that there is a peripheral, strong affinity site for LCT removal and metabolism and a shared peripheral site and specific visceral site for MCT removal and metabolism. PMID:2679038

  17. Effect of Long-Chain Polyunsaturated Fatty Acid Supplementation on Neurodevelopmental Outcome in Full-Term Infants

    PubMed Central

    Hadders-Algra, Mijna

    2010-01-01

    It takes more than 20 years before the human brain obtains its complex, adult configuration. Most dramatic developmental changes occur prenatally and early postnatally. During development, long-chain polyunsaturated fatty acids (LCPUFA) such as doxosahexaenoic acid (DHA) and arachidonic acid (AA) are accreted in the brain. Since breastfeeding is associated with a better developmental outcome than formula feeding, and human milk in contrast to traditional standard formula contains LCPUFA, the question arose whether LCPUFA supplementation of infant formula may promote the neurodevelopmental outcome. The current paper reviews the evidence available in full-term infants. It concludes that postnatal supplementation of formula with LCPUFA is associated with a beneficial effect on short-term neurodevelopmental outcome. However, no evidence is available that LCPUFA supplementation enhances neurodevelopmental outcome in full-term infants beyond the age of four months. Nevertheless, it should be realized that very limited information is available on the effect of LCPUFA supplementation on neurodevelopmental outcome at school age or later. It is conceivable that effects of LCPUFA supplementation first emerge or re-emerge at school age when more complex neural functions are expressed. PMID:22254056

  18. Unsaturated long chain free fatty acids are input signals of the Salmonella enterica PhoP/PhoQ regulatory system.

    PubMed

    Viarengo, Gastón; Sciara, Mariela I; Salazar, Mario O; Kieffer, Pablo M; Furlán, Ricardo L E; García Véscovi, Eleonora

    2013-08-01

    The Salmonella enterica serovar Typhimurium PhoP/PhoQ system has largely been studied as a paradigmatic two-component regulatory system not only to dissect structural and functional aspects of signal transduction in bacteria but also to gain knowledge about the versatile devices that have evolved allowing a pathogenic bacterium to adjust to or counteract environmental stressful conditions along its life cycle. Mg(2+) limitation, acidic pH, and the presence of cationic antimicrobial peptides have been identified as cues that the sensor protein PhoQ can monitor to reprogram Salmonella gene expression to cope with extra- or intracellular challenging conditions. In this work, we show for the first time that long chain unsaturated free fatty acids (LCUFAs) present in Salmonella growth medium are signals specifically detected by PhoQ. We demonstrate that LCUFAs inhibit PhoQ autokinase activity, turning off the expression of the PhoP-dependent regulon. We also show that LCUFAs exert their action independently of their cellular uptake and metabolic utilization by means of the β-oxidative pathway. Our findings put forth the complexity of input signals that can converge to finely tune the activity of the PhoP/PhoQ system. In addition, they provide a new potential biochemical platform for the development of antibacterial strategies to fight against Salmonella infections. PMID:23782700

  19. Effect of medium/ω-6 long chain triglyceride-based emulsion on leucocyte death and inflammatory gene expression

    PubMed Central

    Cury-Boaventura, M F; Gorjão, R; Martins de Lima, T; Fiamoncini, J; Godoy, A B P; Deschamphs, F C; Soriano, F G; Curi, R

    2011-01-01

    Lipid emulsion (LE) containing medium/ω-6 long chain triglyceride-based emulsion (MCT/ω-6 LCT LE) has been recommended in the place of ω-6 LCT-based emulsion to prevent impairment of immune function. The impact of MCT/ω-6 LCT LE on lymphocyte and neutrophil death and expression of genes related to inflammation was investigated. Seven volunteers were recruited and infusion of MCT/ω-6 LCT LE was performed for 6 h. Four volunteers received saline and no change was found. Blood samples were collected before, immediately afterwards and 18 h after LE infusion. Lymphocytes and neutrophils were studied immediately after isolation and after 24 and 48 h in culture. The following determinations were carried out: plasma-free fatty acids, triacylglycerol and cholesterol concentrations, plasma fatty acid composition, neutral lipid accumulation in lymphocytes and neutrophils, signs of lymphocyte and neutrophil death and lymphocyte expression of genes related to inflammation. MCT/ω-6 LCT LE induced lymphocyte and neutrophil death. The mechanism for MCT/ω-6 LCT LE-dependent induction of leucocyte death may involve changes in neutral lipid content and modulation of expression of genes related to cell death, proteolysis, cell signalling, inflammatory response, oxidative stress and transcription. PMID:21682721

  20. Cholestyramine alters the lipid and energy metabolism of chicks fed dietary medium- or long-chain triacylglycerol.

    PubMed

    Mabayo, R T; Furuse, M; Murai, A; Okumura, J

    1995-09-01

    The effects of cholestyramine, a bile acid binding polymer, on the lipid and energy metabolism of chicks given dietary medium-chain triacylglycerol (MCT) or long-chain triacylglycerol (LCT) were investigated. Chicks (from 8 to 17 days of age) were fed diets containing MCT or LCT at 200 g oil/kg diet with or without 2% cholestyramine under equalized feeding conditions. An adjusted LCT diet was formulated in order to supply another group with daily nutrients and dietary metabolizable energy (ME) equal to MCT groups, except for corn starch. ME intakes of chicks given MCT or LCT diets were reduced by cholestyramine; consequently, fat and energy retention was reduced, though the reduction was more drastic in chicks fed LCT. This was caused by a change in amounts of the fecal excretion of fat and bile acids. Cholestyramine enhanced the excretion of octanoic acid (8:0) in the feces, which suggests that bile acids are needed for 8:0 absorption. Cholestyramine affects the utilization of dietary MCT and LCT by lowering fat and energy retention in chicks. However, the effect of cholestyramine on MCT utilization was smaller than its effect on utilization of LCT. PMID:8577228

  1. Biogas production using anaerobic groundwater containing a subterranean microbial community associated with the accretionary prism.

    PubMed

    Baito, Kyohei; Imai, Satomi; Matsushita, Makoto; Otani, Miku; Sato, Yu; Kimura, Hiroyuki

    2015-09-01

    In a deep aquifer associated with an accretionary prism, significant methane (CH₄) is produced by a subterranean microbial community. Here, we developed bioreactors for producing CH₄ and hydrogen (H₂) using anaerobic groundwater collected from the deep aquifer. To generate CH₄, the anaerobic groundwater amended with organic substrates was incubated in the bioreactor. At first, H₂ was detected and accumulated in the gas phase of the bioreactor. After the H₂ decreased, rapid CH₄ production was observed. Phylogenetic analysis targeting 16S rRNA genes revealed that the H₂ -producing fermentative bacterium and hydrogenotrophic methanogen were predominant in the reactor. The results suggested that syntrophic biodegradation of organic substrates by the H₂ -producing fermentative bacterium and the hydrogenotrophic methanogen contributed to the CH₄ production. For H₂ production, the anaerobic groundwater, amended with organic substrates and an inhibitor of methanogens (2-bromoethanesulfonate), was incubated in a bioreactor. After incubation for 24 h, H₂ was detected from the gas phase of the bioreactor and accumulated. Bacterial 16S rRNA gene analysis suggested the dominance of the H₂ -producing fermentative bacterium in the reactor. Our study demonstrated a simple and rapid CH4 and H2 production utilizing anaerobic groundwater containing an active subterranean microbial community. PMID:25267392

  2. Biogas production using anaerobic groundwater containing a subterranean microbial community associated with the accretionary prism

    PubMed Central

    Baito, Kyohei; Imai, Satomi; Matsushita, Makoto; Otani, Miku; Sato, Yu; Kimura, Hiroyuki

    2015-01-01

    In a deep aquifer associated with an accretionary prism, significant methane (CH4) is produced by a subterranean microbial community. Here, we developed bioreactors for producing CH4 and hydrogen (H2) using anaerobic groundwater collected from the deep aquifer. To generate CH4, the anaerobic groundwater amended with organic substrates was incubated in the bioreactor. At first, H2 was detected and accumulated in the gas phase of the bioreactor. After the H2 decreased, rapid CH4 production was observed. Phylogenetic analysis targeting 16S rRNA genes revealed that the H2-producing fermentative bacterium and hydrogenotrophic methanogen were predominant in the reactor. The results suggested that syntrophic biodegradation of organic substrates by the H2-producing fermentative bacterium and the hydrogenotrophic methanogen contributed to the CH4 production. For H2 production, the anaerobic groundwater, amended with organic substrates and an inhibitor of methanogens (2-bromoethanesulfonate), was incubated in a bioreactor. After incubation for 24 h, H2 was detected from the gas phase of the bioreactor and accumulated. Bacterial 16S rRNA gene analysis suggested the dominance of the H2-producing fermentative bacterium in the reactor. Our study demonstrated a simple and rapid CH4 and H2 production utilizing anaerobic groundwater containing an active subterranean microbial community. PMID:25267392

  3. Long-chain n-3 fatty acids enhance neonatal insulin-regulated protein metabolism in piglets by differentially altering muscle lipid composition

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study investigated the role of long-chain n-3 polyunsaturated fatty acids (LCn-3PUFAs) of muscle phospholipids in the regulation of neonatal metabolism. Twenty-eight piglets were weaned at 2 days of age and raised on one of two milk formulas that consisted of either a control formula supplying ...

  4. Effects of Long-Chain Polyunsaturated Fatty Acid Supplementation of Infant Formula on Cognition and Behaviour at 9 Years of Age

    ERIC Educational Resources Information Center

    de Jong, Corina; Kikkert, Hedwig K.; Fidler, Vaclav; Hadders-Algra, Mijna

    2012-01-01

    Aim: Long-chain polyunsaturated fatty acid (LCPUFA) supplementation of infant formula may have a beneficial effect on cognitive development. This study aimed to investigate the effect of LCPUFA formula supplementation primarily on cognition and secondarily on behaviour at age 9 years. Special attention was paid to the potentially modifying effect…

  5. Three Randomized Controlled Trials of Early Long-Chain Polyunsaturated Fatty Acid Supplementation on Means-End Problem Solving in 9-Month-Olds

    ERIC Educational Resources Information Center

    Drover, James; Hoffman, Dennis R.; Castaneda, Yolanda S.; Morale, Sarah E.; Birch, Eileen E.

    2009-01-01

    This study examines whether feeding infants formula supplemented with long-chain polyunsaturated fatty acids (LCPUFA) improves cognitive function of 9-month-olds. Participants included 229 infants from 3 randomized controlled trials. Children received either formula supplemented with docosahexaenoic acid and arachidonic acid, or a control formula…

  6. Changes in cholesterol homeostasis modify the response of F1B hamsters to dietary very long chain n-3 and n-6 polyunsaturated fatty acids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The plasma lipoprotein response of F1B Golden-Syrian hamsters fed diets high in very long chain (VLC) n-3 PUFA is paradoxical to that observed in humans. This anomaly is attributed, in part, to low lipoprotein lipase activity and dependent on cholesterol status. To further elucidate the mechanism(...

  7. Long-chain acylcarnitines activate cell stress and myokine release in C2C12 myotubes: calcium-dependent and independent effects

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Acylcarnitines, important lipid biomarkers reflective of acyl-CoA status, are metabolites that possess bioactive and inflammatory properties. This study examined the potential for long-chain acylcarnitines to activate cellular inflammatory, stress and death pathways in a skeletal muscle model. Diffe...

  8. Nanohybrids of Mg/Al layered double hydroxide and long-chain (C18) unsaturated fatty acid anions: Structure and sorptive properties

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Long-chain (C18) unsaturated fatty acid anions, elaidate (ELA), oleate (OLE), linoleate (LINO), and linolenate (LINOLEN), were intercalated into Mg/Al (3:1) layered double hydroxide (LDH) and the resultant organo-LDH nanohybrid materials were characterized and subsequently evaluated as sorbents of s...

  9. Development and enteral long-chain n-3 fatty acids differentially alters muscle intracellular pools of free amino acids in the neonate piglet

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recent studies suggest that feeding long-chain n-3 fatty acids (LCn-3FA) in the diet may blunt the developmental reduction in insulin sensitivity and anabolism in the neonate piglet. To examine the effect of LCn-3FA on protein anabolism, 2-day-old piglets (n=28) were weaned and assigned to one of t...

  10. Link between capacity for current production and syntrophic growth in Geobacter species

    PubMed Central

    Rotaru, Amelia-Elena; Woodard, Trevor L.; Nevin, Kelly P.; Lovley, Derek R.

    2015-01-01

    Electrodes are unnatural electron acceptors, and it is yet unknown how some Geobacter species evolved to use electrodes as terminal electron acceptors. Analysis of different Geobacter species revealed that they varied in their capacity for current production. Geobacter metallireducens and G. hydrogenophilus generated high current densities (ca. 0.2 mA/cm2), comparable to G. sulfurreducens. G. bremensis, G. chapellei, G. humireducens, and G. uraniireducens, produced much lower currents (ca. 0.05 mA/cm2) and G. bemidjiensis was previously found to not produce current. There was no correspondence between the effectiveness of current generation and Fe(III) oxide reduction rates. Some high-current-density strains (G. metallireducens and G. hydrogenophilus) reduced Fe(III)-oxides as fast as some low-current-density strains (G. bremensis, G. humireducens, and G. uraniireducens) whereas other low-current-density strains (G. bemidjiensis and G. chapellei) reduced Fe(III) oxide as slowly as G. sulfurreducens, a high-current-density strain. However, there was a correspondence between the ability to produce higher currents and the ability to grow syntrophically. G. hydrogenophilus was found to grow in co-culture with Methanosarcina barkeri, which is capable of direct interspecies electron transfer (DIET), but not with Methanospirillum hungatei capable only of H2 or formate transfer. Conductive granular activated carbon (GAC) stimulated metabolism of the G. hydrogenophilus – M. barkeri co-culture, consistent with electron exchange via DIET. These findings, coupled with the previous finding that G. metallireducens and G. sulfurreducens are also capable of DIET, suggest that evolution to optimize DIET has fortuitously conferred the capability for high-density current production to some Geobacter species. PMID:26284037

  11. Toxicity and biodegradability of olive mill wastewaters in batch anaerobic digestion

    SciTech Connect

    Hamdi, M. Universite de Provence, Marseille )

    1992-11-01

    The anaerobic biodegradability and toxicity of olive mill wastewaters (OMW) were studied in batch anaerobic digestion experiments. Anaerobic digestion of OMW or the supernatant of its centrifugation, the methane production was achieved at up to 5-15% (V/V) dilution corresponding to only 5-20 g/L COD. The washed suspended solids of OMW were toxic at up to 80 g/L COD; however, the kinetic of biodegradability of OMW or the supernatant was faster than for suspended solids, which are constituted mealy of cellulose and lignin. The darkly colored polyphenols induce the problem of biodegradation of OMW, whereas the long chain fatty acids (LCFA), tannins and simple phenolic compounds are responsible for its toxicity for methanogenic bacteria. 26 refs., 4 figs., 1 tab.

  12. Anthocyanins do not influence long-chain n-3 fatty acid status: studies in cells, rodents and humans.

    PubMed

    Vauzour, David; Tejera, Noemi; O'Neill, Colette; Booz, Valeria; Jude, Baptiste; Wolf, Insa M A; Rigby, Neil; Silvan, Jose Manuel; Curtis, Peter J; Cassidy, Aedin; de Pascual-Teresa, Sonia; Rimbach, Gerald; Minihane, Anne Marie

    2015-03-01

    Increased tissue status of the long-chain n-3 polyunsaturated fatty acids (LC n-3 PUFA), eicosapentaenoic (EPA) and docosahexaenoic acid (DHA) is associated with cardiovascular and cognitive benefits. Limited epidemiological and animal data suggest that flavonoids, and specifically anthocyanins, may increase EPA and DHA levels, potentially by increasing their synthesis from the shorter-chain n-3 PUFA, α-linolenic acid. Using complimentary cell, rodent and human studies we investigated the impact of anthocyanins and anthocyanin-rich foods/extracts on plasma and tissue EPA and DHA levels and on the expression of fatty acid desaturase 2 (FADS2), which represents the rate limiting enzymes in EPA and DHA synthesis. In experiment 1, rats were fed a standard diet containing either palm oil or rapeseed oil supplemented with pure anthocyanins for 8 weeks. Retrospective fatty acid analysis was conducted on plasma samples collected from a human randomized controlled trial where participants consumed an elderberry extract for 12 weeks (experiment 2). HepG2 cells were cultured with α-linolenic acid with or without select anthocyanins and their in vivo metabolites for 24 h and 48 h (experiment 3). The fatty acid composition of the cell membranes, plasma and liver tissues were analyzed by gas chromatography. Anthocyanins and anthocyanin-rich food intake had no significant impact on EPA or DHA status or FADS2 gene expression in any model system. These data indicate little impact of dietary anthocyanins on n-3 PUFA distribution and suggest that the increasingly recognized benefits of anthocyanins are unlikely to be the result of a beneficial impact on tissue fatty acid status. PMID:25573539

  13. Unsaturation of very-long-chain ceramides protects plant from hypoxia-induced damages by modulating ethylene signaling in Arabidopsis.

    PubMed

    Xie, Li-Juan; Chen, Qin-Fang; Chen, Mo-Xian; Yu, Lu-Jun; Huang, Li; Chen, Liang; Wang, Feng-Zhu; Xia, Fan-Nv; Zhu, Tian-Ren; Wu, Jian-Xin; Yin, Jian; Liao, Bin; Shi, Jianxin; Zhang, Jian-Hua; Aharoni, Asaph; Yao, Nan; Shu, Wensheng; Xiao, Shi

    2015-03-01

    Lipid remodeling is crucial for hypoxic tolerance in animals, whilst little is known about the hypoxia-induced lipid dynamics in plants. Here we performed a mass spectrometry-based analysis to survey the lipid profiles of Arabidopsis rosettes under various hypoxic conditions. We observed that hypoxia caused a significant increase in total amounts of phosphatidylserine, phosphatidic acid and oxidized lipids, but a decrease in phosphatidylcholine (PC) and phosphatidylethanolamine (PE). Particularly, significant gains in the polyunsaturated species of PC, PE and phosphatidylinositol, and losses in their saturated and mono-unsaturated species were evident during hypoxia. Moreover, hypoxia led to a remarkable elevation of ceramides and hydroxyceramides. Disruption of ceramide synthases LOH1, LOH2 and LOH3 enhanced plant sensitivity to dark submergence, but displayed more resistance to submergence under light than wild type. Consistently, levels of unsaturated very-long-chain (VLC) ceramide species (22:1, 24:1 and 26:1) predominantly declined in the loh1, loh2 and loh3 mutants under dark submergence. In contrast, significant reduction of VLC ceramides in the loh1-1 loh3-1 knockdown double mutant and lacking of VLC unsaturated ceramides in the ads2 mutants impaired plant tolerance to both dark and light submergences. Evidence that C24:1-ceramide interacted with recombinant CTR1 protein and inhibited its kinase activity in vitro, enhanced ER-to-nucleus translocation of EIN2-GFP and stabilization of EIN3-GFP in vivo, suggests a role of ceramides in modulating CTR1-mediated ethylene signaling. The dark submergence-sensitive phenotypes of loh mutants were rescued by a ctr1-1 mutation. Thus, our findings demonstrate that unsaturation of VLC ceramides is a protective strategy for hypoxic tolerance in Arabidopsis. PMID:25822663

  14. Mechano-switchable, luminescent gels derived from salts of a long-chained, fatty-acid gelator.

    PubMed

    Zhang, Mohan; Weiss, Richard G

    2016-07-27

    Stimulus-responsive molecular gel systems, based on metal salts of a luminescent gelator, 9,10-dioxooctadecanoic acid (DODA), are reported. These salts are structurally the simplest metallo-gelators of which we are aware that exhibit controllable mechano-responsive and luminescent properties. Aggregation is more favored by the metal salts than for DODA itself. However, gelation ability differs dramatically depending on the metal ion: whereas the salts with zinc(ii) and calcium(ii) are inefficient gelators, those with nickel(ii) and copper(ii) can gelate various aromatic liquids, alkanes, and long-chained alcohols. Unlike the DODA gels, no aggregation-induced shift in the positions of the emission spectra of the metal salts could be observed as the sols were transformed to their gel phases. Gels of both nickel(ii) and copper(ii) salts in benzonitrile are among the few known examples with crystalline networks and exhibiting thixotropic behavior. However, there are significant differences in their abilities to recover the initial viscoelastic properties. Structural data for the solid and gel states lead us to conclude that differences among the gelating abilities can be attributed principally to the specific nature of interactions of the salts at their head groups. They appear to control the mechanical and emissive properties of the gels as well as whether the initial aggregation of the salts in the sol phases will support the growth of 1D objects that are capable of maintaining strong contacts, leading to 3D networks and gel formation. Overall, the results provide a facile strategy for the design of luminescent materials with controllable mechano-responsiveness by modifying the metal ions within fibrillar assemblies. PMID:27400800

  15. Analysis of fluorotelomer alcohols, fluorotelomer acids, and short- and long-chain perfluorinated acids in water and biota.

    PubMed

    Taniyasu, Sachi; Kannan, Kurunthachalam; So, Man Ka; Gulkowska, Anna; Sinclair, Ewan; Okazawa, Tsuyoshi; Yamashita, Nobuyoshi

    2005-11-01

    Fluorotelomer alcohols and fluorotelomer acids have been proposed as a source of the perfluorinated carboxylic acids found in remote marine locations. To examine the sources and fate of perfluorinated acids in the environment, a method to determine a wide range of poly- and perfluorinated acids in environmental and biological matrices is needed. In this study, a method has been developed to measure a suite of neutral and acidic fluorochemicals including, fluorotelomer alcohols, fluorotelomer acids, and short- and long-chain perfluorinated acids, in water and biological samples. The method involves solid-phase extraction with weak anion exchange (WAX) cartridges, followed by sequential elution with sodium acetate buffer, methanol, and 0.1% NH4OH in methanol. For biological samples, prior to solid-phase extraction, tissues are digested in 0.5N potassium hydroxide/methanol, diluted in water, and passed through the WAX cartridge. Neutral compounds and telomer alcohols are separated from other poly- and perfluorinated acids. The method is robust (i.e., capable of measuring neutral and acidic compounds), and can be applied for the analysis of a range of poly- and perfluorinated acids, including telomer alcohols, telomer acids, perfluoroalkylcarboxylates, and perfluoroalkylsulfonates in water and biota. With the use of high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), a method detection limit in the range of several tens to hundreds of parts-per-quadrillion (pg/L) in water and at a few tens to hundreds of parts-per-trillion (pg/g) levels in biological matrices can be achieved. PMID:16233874

  16. Microchip Non-Aqueous Capillary Electrophoresis (MicronNACE) Method to Analyze Long-Chain Primary Amines

    NASA Technical Reports Server (NTRS)

    Willis, Peter A.; Mora, Maria; Cable, Morgan L.; Stockton, Amanda M.

    2012-01-01

    A protocol was developed as a first step in analyzing the complex organic aerosols present on Saturn's moon Titan, as well as the analogues of these aerosols (tholins) made on Earth. Labeling of primary amines using Pacific Blue succinimidyl ester is effected in ethanol with 25 mM triethylamine to maintain basic conditions. This reaction is allowed to equilibrate for at least one hour. Separation of the labeled primary amines is performed in ethanol with 1.05 M acetic acid, and 50 mM ammonium acetate in a commercial two-layer glass device with a standard crossmicrochannel measuring 50 microns wide by 20 microns deep. Injection potentials are optimized at 2 kV from the sample (negative) to the waste well (positive), with slight bias applied to the other two wells ( 0.4 and 0.8 V) to pinch the injection plug for the 30-s injection. Separation is performed at a potential of 5 kV along the channel, which has an effective separation distance of 7 cm. The use of ethanol in this method means that long-chain primary amines can be dissolved. Due to the low pH of the separation buffer, electro-osmotic flow (EOF) is minimized to allow for separation of both short-chain and longchain amines. As the freezing point of ethanol is much lower than water, this protocol can perform separations at temperatures lower than 0 C, which would not be possible in aqueous phase. This is of particular importance when considering in situ sampling of Titan aerosols, where unnecessary heating of the sample (even to room temperature) would lead to decomposition or unpredictable side reactions, which would make it difficult to characterize the sample appropriately.

  17. Adult medication-free schizophrenic patients exhibit long-chain omega-3 Fatty Acid deficiency: implications for cardiovascular disease risk.

    PubMed

    McNamara, Robert K; Jandacek, Ronald; Rider, Therese; Tso, Patrick; Dwivedi, Yogesh; Pandey, Ghanshyam N

    2013-01-01

    Deficiency in long-chain omega-3 (LCn - 3) fatty acids, eicosapentaenoic acid (EPA, 20:5n - 3) and docosahexaenoic acid (DHA, 22:6n - 3), has been implicated in the pathoetiology of cardiovascular disease, a primary cause of excess premature mortality in patients with schizophrenia (SZ). In the present study, we determined erythrocyte EPA + DHA levels in adult medication-free patients SZ (n = 20) and age-matched healthy controls (n = 24). Erythrocyte EPA + DHA composition exhibited by SZ patients (3.5%) was significantly lower than healthy controls (4.5%, -22%, P = 0.007). The majority of SZ patients (72%) exhibited EPA+DHA levels ≤4.0% compared with 37% of controls (Chi-square, P = 0.001). In contrast, the omega-6 fatty acid arachidonic acid (AA, 20:4n - 6) (+9%, P = 0.02) and the AA:EPA + DHA ratio (+28%, P = 0.0004) were significantly greater in SZ patients. Linoleic acid (18:2n - 6) was significantly lower (-12%, P = 0.009) and the erythrocyte 20:3/18:2 ratio (an index of delta6-desaturase activity) was significantly elevated in SZ patients. Compared with same-gender controls, EPA + DHA composition was significantly lower in male (-19%, P = 0.04) but not female (-13%, P = 0.33) SZ patients, whereas the 20:3/18:2 ratio was significantly elevated in both male (+22%, P = 0.008) and female (+22%, P = 0.04) SZ patients. These results suggest that the majority of SZ patients exhibit low LCn - 3 fatty acid levels which may place them at increased risk for cardiovascular morbidity and mortality. PMID:23533712

  18. Dietary long-chain PUFA in the form of TAG or phospholipids influence lymph lipoprotein size and composition in piglets.

    PubMed

    Amate, Laura; Gil, Angel; Ramírez, María

    2002-10-01

    Several sources of long-chain PUFA (LCP) are currently available for infant formula supplementation. These oils differ in their FA composition, the chemical form of the FA esters [TAG or phospholipids (PL)], and presence of other lipid components. These differences may affect LCP absorption, distribution, and metabolic fate after ingestion. The purpose of this study was to evaluate the influence of different chemical forms of dietary LCP on the composition of lymph lipoproteins. Eighteen pigs (5 d old) were bottle-fed different diets for 2 wk: a control diet (C), a diet containing LCP as TAG from tuna and fungal oils (TF-TAG), or a diet containing LCP as PL from egg yolk (E-PL). We measured lipid and FA composition of lymph, main lymph fractions (TAG or PL), and the particle size of lymph lipoproteins. The average diameter of lymph lipoproteins was significantly lower in the E-PL group compared with the control and TF-TAG groups (C: 3902 +/- 384 A; TF-TAG: 3773 +/- 384 A; E-PL: 2370 +/- 185 A). Arachidonic acid and DHA contents in lymph and lymph-TAG were significantly higher in the TF-TAG group compared to the E-PL group (0.50 +/- 0.03 and 0.24 +/- 0.03 g/100 g vs. 0.29 +/- 0.04 and 0.12 +/- 0.03 g/100 g, respectively). The addition to the diet of LCP in the form of TAG or PL affected the size of intestinal lipoproteins and also led to a different distribution of these FA in lymph lipoproteins. PMID:12530557

  19. Long Chain Alcohols Produced by Trichoderma citrinoviride Have Phagodeterrent Activity against the Bird Cherry-Oat Aphid Rhopalosiphum padi

    PubMed Central

    Ganassi, Sonia; Grazioso, Pasqualina; De Cristofaro, Antonio; Fiorentini, Fabio; Sabatini, Maria Agnese; Evidente, Antonio; Altomare, Claudio

    2016-01-01

    In this study we report the effects of fungal metabolites isolated from cultures of the fungus Trichoderma citrinoviride ITEM 4484 on the feeding preference of the aphid Rhopalosiphum padi, a major pest of cereal crops. Different phagodeterrent metabolites were purified by a combination of direct and reverse phase column chromatography and thin-layer chromatography. Chemical investigations, by spectroscopic and chemical methods, led to the identification of different long chain primary alcohols (LCOHs) of the general formula R-OH, wherein R is a long, unbranched, unsubstituted, linear aliphatic group. LCOHs have been reported as components of lepidopteran pheromone blends, but their phagodeterrent effect to aphids is herein reported for the first time. The effects of LCOHs on R. padi were studied by behavioral and electrophysiological bioassays. Feeding preference tests that were carried out with winged and wingless morphs of R. padi showed that LCOHs had high phagodeterrent activity and restrained aphids from settling on treated leaves at a concentration as low as 0.15 mM (0.036 g/l). The results of different electrophysiological analyses indicated that taste receptor neurons located on the aphid tarsomeres were involved in the LCOHs perception. Behavioral assays carried out with some commercial agrochemicals, including azadirachtin A, pyrethrum and a mineral oil-based product, in combination with 1-hexadecanol, the LCOH most abundantly produced by T. citrinoviride ITEM 4484, showed that these different active principles could be applied together, resulting in a useful increase of the phagodeterrent effect. The data shown indicate that these compounds can be profitably utilized for novel applications in biotechnical control of aphid pests. Furthermore, the tested LCOHs have no chiral centers and therefore can be obtained with good yield and at low cost through chemical synthesis, as well as from natural sources. PMID:27014220

  20. Structural identification of long-chain polyamines associated with diatom biosilica in a Southern Ocean sediment core

    NASA Astrophysics Data System (ADS)

    Bridoux, Maxime C.; Ingalls, Anitra E.

    2010-07-01

    Long-chain polyamines (LCPAs) constitute a new family of natural organic compounds that have recently been isolated and characterized from the biosilicified cell walls of diatom cultures. To date, diatom-specific polyamines have not been investigated from the marine environment and their fate in the environment is entirely unknown. Here, we report a series of LCPAs in a diatom frustule-rich sediment core (TNO57-13 PC4), originating from the Atlantic sector of the Southern Ocean and spanning from the Holocene to the Last Glacial Maximum (LGM). Liquid chromatography with electrospray ionization mass spectrometry (LC-ESI-MS) revealed a complex mixture of linear polyamines with at least 28 individual molecular species. Ion trap mass fragmentation studies, combined with high resolution Time of Flight (TOF) mass spectrometry showed that the polyamine pool consisted of a series of N-methylated propylamine compounds attached to a putrescine moiety, with individual LCPAs varying in chain length and degree of methylation. The structural similarity between LCPAs extracted from the diatom-rich sediment core and those extracted from the frustules of cultured diatoms suggests that sedimentary LCPAs are derived from diatom frustules. We hypothesize that these intrinsically labile organic molecular fossils are protected from diagenesis by encapsulation within the frustule. These compounds constitute a new class of biomarkers that could potentially be indicators of diatom species distribution. Isotopic analysis of LCPAs could be used to improve age models for sediment cores that lack calcium carbonate and to improve current interpretations of diatom-based paleoproxies, including diatom-bound nitrogen isotopes.

  1. Anthocyanins do not influence long-chain n-3 fatty acid status: studies in cells, rodents and humans☆

    PubMed Central

    Vauzour, David; Tejera, Noemi; O'Neill, Colette; Booz, Valeria; Jude, Baptiste; Wolf, Insa M.A.; Rigby, Neil; Silvan, Jose Manuel; Curtis, Peter J.; Cassidy, Aedin; de Pascual-Teresa, Sonia; Rimbach, Gerald; Minihane, Anne Marie

    2015-01-01

    Increased tissue status of the long-chain n-3 polyunsaturated fatty acids (LC n-3 PUFA), eicosapentaenoic (EPA) and docosahexaenoic acid (DHA) is associated with cardiovascular and cognitive benefits. Limited epidemiological and animal data suggest that flavonoids, and specifically anthocyanins, may increase EPA and DHA levels, potentially by increasing their synthesis from the shorter-chain n-3 PUFA, α-linolenic acid. Using complimentary cell, rodent and human studies we investigated the impact of anthocyanins and anthocyanin-rich foods/extracts on plasma and tissue EPA and DHA levels and on the expression of fatty acid desaturase 2 (FADS2), which represents the rate limiting enzymes in EPA and DHA synthesis. In experiment 1, rats were fed a standard diet containing either palm oil or rapeseed oil supplemented with pure anthocyanins for 8 weeks. Retrospective fatty acid analysis was conducted on plasma samples collected from a human randomized controlled trial where participants consumed an elderberry extract for 12 weeks (experiment 2). HepG2 cells were cultured with α-linolenic acid with or without select anthocyanins and their in vivo metabolites for 24 h and 48 h (experiment 3). The fatty acid composition of the cell membranes, plasma and liver tissues were analyzed by gas chromatography. Anthocyanins and anthocyanin-rich food intake had no significant impact on EPA or DHA status or FADS2 gene expression in any model system. These data indicate little impact of dietary anthocyanins on n-3 PUFA distribution and suggest that the increasingly recognized benefits of anthocyanins are unlikely to be the result of a beneficial impact on tissue fatty acid status. PMID:25573539

  2. Very-long-chain fatty acids restrict regeneration capacity by confining pericycle competence for callus formation in Arabidopsis.

    PubMed

    Shang, Baoshuan; Xu, Chongyi; Zhang, Xixi; Cao, Huifen; Xin, Wei; Hu, Yuxin

    2016-05-01

    The already differentiated organs in plants have a remarkable capacity to regenerate new individuals under culture conditions. Plant in vitro regeneration practically starts with the induction of a pluripotent cell mass, the callus, from detached organs on auxin-rich callus-inducing medium (CIM), which is generally required for subsequent regeneration of new bodies. Recent studies show that CIM-induced callus formation occurs from the pericycle or pericycle-like cells through a root developmental pathway, whereas the signals involved in governing callus-forming capacity of pericycle cells remain unknown. Here we report that very-long-chain fatty acids (VLCFAs) play a critical role in confining the pericycle competence for callus formation and thus the regeneration capacity of Arabidopsis By genetic screening, we identified the callus formation-related 1 (cfr1) mutant, which bypasses the inhibition of callus-forming capacity in roots by solitary-root (slr/iaa14). We show that CFR1 encodes 3-ketoacyl-CoA synthase 1 (KCS1), which catalyzes a rate-limiting step of VLCFA biosynthesis. Our biochemical and genetic analyses demonstrate that VLCFAs restrict the pericycle competence for callus formation, at least in part, by regulating the transcription of Aberrant Lateral Root Formation 4 (ALF4). Moreover, we provide evidence that VLCFAs act as cell layer signals to mediate the pericycle competence for callus formation. Taken together, our results identify VLCFAs or their derivatives as the confining signals for mediating the pericycle competence for callus formation and thus the regeneration capacity of plant organs. PMID:27092001

  3. Concentrations and abundance ratios of long-chain alkenones and glycerol dialkyl glycerol tetraethers in sinking particles south of Java

    NASA Astrophysics Data System (ADS)

    Chen, Wenwen; Mohtadi, Mahyar; Schefuß, Enno; Mollenhauer, Gesine

    2016-06-01

    In this study, we obtained concentrations and abundance ratios of long-chain alkenones and glycerol dialkyl glycerol tetraethers (GDGTs) in a one-year time-series of sinking particles collected with a sediment trap moored from December 2001 to November 2002 at 2200 m water depth south of Java in the eastern Indian Ocean. We investigate the seasonality of alkenone and GDGT fluxes as well as the potential habitat depth of the Thaumarchaeota producing the GDGTs entrained in sinking particles. The alkenone flux shows a pronounced seasonality and ranges from 1 μg m-2 d-1 to 35 μg m-2 d-1. The highest alkenone flux is observed in late September during the Southeast monsoon, coincident with high total organic carbon fluxes as well as high net primary productivity. Flux-weighted mean temperature for the high flux period using the alkenone-based sea-surface temperature (SST) index U37K‧ is 26.7 °C, which is similar to satellite-derived Southeast (SE) monsoon SST (26.4 °C). The GDGT flux displays a weaker seasonality than that of the alkenones. It is elevated during the SE monsoon period compared to the Northwest (NW) monsoon and intermonsoon periods (approximately 2.5 times), which is probably related to seasonal variation of the abundance of Thaumarchaeota, or to enhanced export of GDGTs by aggregation with sinking phytoplankton detritus. Flux-weighted mean temperature inferred from the GDGT-based TEX86H index is 26.2 °C, which is 1.8 °C lower than mean annual (ma) SST but similar to SE monsoon SST. As the time series of TEX86H temperature estimates, however, does not record a strong seasonal amplitude, we infer that TEX86H reflects ma upper thermocline temperature at approximately 50 m water depth.

  4. A Peroxisomal Long-Chain Acyl-CoA Synthetase from Glycine max Involved in Lipid Degradation

    PubMed Central

    Jiang, Bingjun; Sun, Xuegang; Gu, Shoulai; Han, Tianfu; Hou, Wensheng

    2014-01-01

    Seed storage oil, in the form of triacylglycerol (TAG), is degraded to provide carbon and energy during germination and early seedling growth by the fatty acid β-oxidation in the peroxisome. Although the pathways for lipid degradation have been uncovered, understanding of the exact involved enzymes in soybean is still limited. Long-chain acyl-CoA synthetase (ACSL) is a critical enzyme that activates free fatty acid released from TAG to form the fatty acyl-CoA. Recent studies have shown the importance of ACSL in lipid degradation and synthesis, but few studies were focused on soybean. In this work, we cloned a ACSL gene from soybean and designated it as GmACSL2. Sequence analysis revealed that GmACSL2 encodes a protein of 733 amino acid residues, which is highly homologous to the ones in other higher plants. Complementation test showed that GmACSL2 could restore the growth of an ACS-deficient yeast strain (YB525). Co-expression assay in Nicotiana benthamiana indicated that GmACSL2 is located at peroxisome. Expression pattern analysis showed that GmACSL2 is highly expressed in germinating seedling and strongly induced 1 day after imbibition, which indicate that GmACSL2 may take part in the seed germination. GmACSL2 overexpression in yeast and soybean hairy root severely reduces the contents of the lipids and fatty acids, compared with controls in both cells, and enhances the β-oxidation efficiency in yeast. All these results suggest that GmACSL2 may take part in fatty acid and lipid degradation. In conclusion, peroxisomal GmACSL2 from Glycine max probably be involved in the lipid degradation during seed germination. PMID:24992019

  5. Neurophysiologic measures of auditory function in fish consumers: associations with long chain polyunsaturated fatty acids and methylmercury

    PubMed Central

    Dziorny, Adam C.; Orlando, Mark S.; Strain, J. J.; Davidson, Philip W.; Myers, Gary J.

    2012-01-01

    Background Determining if associations exist between child neurodevelopment and environmental exposures, especially low level or background ones, is challenging and dependent upon being able to measure specific and sensitive endpoints. Psychometric or behavioral measures of CNS function have traditionally been used in such studies, but do have some limitations. Auditory neurophysiologic measures examine different nervous system structures and mechanisms, have fewer limitations, can more easily by quantified, and might be helpful testing additions. To date, their use in human epidemiological studies has been limited. We reviewed the use of auditory brainstem responses (ABR) and otoacoustic emissions (OAE) in studies designed to determine the relationship of exposures to methyl mercury (MeHg) and nutrients from fish consumption with neurological development. We included studies of experimental animals and humans in an effort to better understand the possible benefits and risks of fish consumption. Objectives We reviewed the literature on the use of ABR and OAE to measure associations with environmental exposures that result from consuming a diet high in fish. We focused specifically on long chain polyunsaturated fatty acids (LCPUFA) and MeHg. Methods We performed a comprehensive review of relevant studies using web-based search tools and appropriate search terms. Results Gestational exposure to both LCPUFA and MeHg has been reported to influence the developing auditory system. In experimental studies supplemental LCPUFA is reported to prolong ABR latencies and human studies also suggest an association. Experimental studies of acute and gestational MeHg exposure are reported to prolong ABR latencies and impair hair cell function. In humans, MeHg exposure is reported to prolong ABR latencies, but the impact on hair cell function is unknown. Conclusion The auditory system can provide objective measures and may be useful in studying exposures to nutrients and toxicants

  6. Effects of hypo- and hyperthyroidism on rat liver microsomal long-chain fatty acyl-CoA synthetase and hydrolase

    SciTech Connect

    Dang, A.Q.; Faas, F.H.; Carter, W.J.

    1986-05-01

    The effects of hyperthyroidism (hyperT/sub 3/), (tri-iodothryonine (T/sub 3/) injected rats), and hypothyroidism (hypoT/sub 3/) (thyroidectomized rats) on the activation of fatty acids by a microsomal long-chain fatty acyl-CoA (LCA-CoA) synthetase and the degradation of LCA-CoA by a microsomal LCA-CoA hydrolase was determined. MAS was assayed by measuring the (1-/sup 14/C)-palmitate or -1-/sup 14/C) oleate incorporated into its water soluble CoA ester. MAH was assayed spectrophotomerically by following the reduction of 5',5'-dithiobis-(2-nitrobenzoic acid) by the CoA released from palmitoyl-CoA or oleoyl-CoA. Enzyme activities are given as mean (nmoles/mg/min) +/- SEM. MAS activities were decreased 36-44% (p < 0.01) in both hypoT/sub 3/ and hyperT/sub 3/ (controls = 101 +/- 4 (n = 11, (1-/sup 14/C)-palmitate) of 72 +/- 2 (n = 5,(1-/sup 14/C)oleate)). These decreases may contribute to the decreased triacelyglycerol (TG) and phospholipid contents in the hyperT/sub 3/ liver and the decreased clearance rate of plasma TG in the hypoT/sub 3/. MAH was decreased 27-42% (p<0.01) only in hypoT/sub 3/ (controls = 77 +/- 3 (n = 11, palmitoyl-CoA) or 45 +/- 1 (n = 5, oleoyl-CoA)). This decrease was corrected by T/sub 3/ treatment. Since the decreased MAH would increase the availability of LCA-CoA, it may contribute to the increased TG synthesis in hypoT/sub 3/.

  7. Moderate carnitine depletion and long-chain fatty acid oxidation, exercise capacity, and nitrogen balance in the rat.

    PubMed

    Heinonen, O J; Takala, J

    1994-09-01

    Carnitine plays a central role in lipid metabolism by transporting long-chain fatty acids into the mitochondria for beta-oxidation. Reduction of carnitine concentration does not automatically imply that functional carnitine deficiency exists with direct consequences on energy metabolism. In our experimental model, we reduced tissue concentrations of carnitine to levels that are comparable to those in patients with various metabolic disorders with secondary carnitine deficiency and did a study on the in vivo effects of moderate carnitine depletion on palmitate oxidation, exercise capacity, and nitrogen balance. Thirty rats were divided into a carnitine-depleted group (group I) and pair-fed controls (group II). Carnitine depletion resulting in a 48% reduction of tissue carnitine concentrations was induced by feeding ad libitum a carnitine-free oral diet consisting of parenteral nutrition solutions. Palmitate oxidation was measured by collecting expired 14CO2 after an intraperitoneal injection of [1-14C]palmitate, and exercise capacity was determined by having the rats swim to exhaustion. Despite the 48% depletion of carnitine in serum, muscle, and liver, there were no differences in cumulative palmitate oxidation in 3 h (group I, 40 +/- 7%; group II, 37 +/- 9% of injected activity), swimming time to exhaustion (group I, 8.1 +/- 2.8 h; group II, 7.7 +/- 3.6 h), or nitrogen balance (group I, 1.1 +/- 0.5 g of nitrogen/kg/d; group II, 1.2 +/- 0.5 g of nitrogen/kg/d). We conclude that carnitine depletion of 48% has no effect on palmitate oxidation, exercise capacity, or nitrogen balance in the rats studied. PMID:7808823

  8. Effect of medium- and long-chain triglyceride infusion on lipoprotein and hepatic lipase in healthy subjects.

    PubMed

    Nordenström, J; Neeser, G; Olivecrona, T; Wahren, J

    1991-12-01

    Plasma lipolytic activity and hydrolysis of intravenous fat were studied in six healthy subjects during infusion of a long-chain triglyceride (LCT) fat emulsion (Intralipid 20%) or of a medium-chain triglyceride (MCT)/LCT emulsion (Lipofundin MCT 20%). The fat emulsions were infused continuously at a rate of 0.17 g triglyceride kg-1 body weight (BW)h-1 for 6 h in random order at 7-day intervals. A continuous infusion of glucose (0.18 g kg-1 BW h-1) was administered for a period of 7 h and was started 1 h before the lipid infusion. Infusions of both types of fat increased plasma triglyceride (TG), free fatty acid (FFA) and lipoprotein lipase (LPL) levels and steady-state values were present during the 3rd to 5th h of infusion. MCT/LCT infusion resulted in higher plasma levels at steady-state of TG (3.63 +/- 0.45 [SEM] vs 2.73 +/- 0.45 mmol l-1; P less than 0.05), FFA (1.05 +/- 0.08 vs 0.54 +/- 0.04 mmol l-1; P less than 0.01) and LPL (4.6 +/- 0.6 vs 2.6 +/- 0.5 mU ml-1; P less than 0.05) in comparison with LCT administration. There was a positive correlation between plasma LPL activity and TG concentration (r = 0.77; P less than 0.001) when data for the two infusions were combined. Although the same amount of fat was infused on a weight basis, the molar infusion rate was 40% higher with MCT/LCT than with LCT infusion, due to differences in molecular weights (634 vs 885 Da).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1778219

  9. Evaluating the potential of long chain n-alkanes and n-carboxylic acids as biomarkers for past vegetation

    NASA Astrophysics Data System (ADS)

    Lanny, Verena; Zech, Roland; Eglinton, Timothy

    2014-05-01

    Leaf waxes, such as long chain n-alkanes and n-carboxylic acids, may have a great potential for the reconstruction of past environmental and climate conditions (e.g. (Zech R. et al., 2013). While n-C27 and n-C29 alkanes often predominantly occur in trees and shrubs, n-C31 and n-C33 are more abundant in grasses and herbs. However, little is known about chain-length distributions of n-carboxylic acids, and very few studies have systematically investigated leaf waxes in top soils. We analyzed n-alkanes and n-carboxylic acids in ~100 litter and topsoil samples from Southern Germany to Sweden. Our results show that sites under deciduous trees often contain a lot of C27 n-alkanes and C28 n-carboxylic acids. Coniferous sites are characterized by dominance in n-alkanes C29 and C31 and have relatively high concentrations of n-carboxylic acids C22 and C24. Grass sites show a Cmax at C31 for n-alkanes and at C24 or C26 for n-carboxylic acids. Differences in homologue patterns are most pronounced in the litter samples, but are well preserved also in the topsoils (0-3 cm depth, a little less in the lower topsoils from 3-10 cm). Our results illustrate the potential of combining n-alkane and n-carboxylic acid analyses for paleo-vegetation reconstructions, yet indicate that the degree of degradation may have to be taken into consideration (Zech M. et al., 2013). References: Zech, M. et al. (2013) Quat. Int. 296, 108-116. Zech, R. et al. (2013) Palaeo3, 387, 165-175.

  10. Genetic basis of long-chain aliphatic hydrocarbon biosynthesis in bacteria. Final technical report, July 7, 1981-January 6, 1983

    SciTech Connect

    Kloos, W.E.

    1983-01-01

    A variety of Micrococcus species, some related Arthrobacter, and Pseudomonas maltophilia are among the few bacteria which produce significant quantities of long chain aliphatic hydrocarbons. It was the purpose of this investigation to initiate studies aimed at understanding the genetic basis of aliphatic hydrocarbon production. Results have shown that some strains of several of the Micrococcus species carry plasmids, but they appear not to be associated with hydrocarbon production. Clearly, plasmids are not required for hydrocarbon biosynthesis, as many plasmidless strains produce large quantities of hydrocarbons with normal species-specific profiles. This is the first report on the occurrence of plasmids in Micrococcus species such as M. roseus, M. varians, M. kristinae, M. agilis, M. nishinomiyaensis, and unnamed, nonhuman primate Micrococcus spp. It is also the first report on aliphatic hydrocarbon production in M. agilis and the above nonhuman primate species. Although hydrocarbon production is not specifically under plasmid control, micrococcal plasmids may be able to serve as vectors for cloned hydrocarbon biosynthesis genes and ultimately used in the genetic engineering of this important group of organisms. For this reason, we initiated studies on the nucleotide sequence relationships, restriction enzyme digestion, and marking of several of the more interesting plasmids. Results have indicated that within species some plasmids share considerable nucleotide sequence homology. It is recommended that future investigations on these organisms should focus on unraveling the hydrocarbon biosynthetic pathway(s), isolating and characterizing the various enzymes involved with hydrocarbon biosynthesis, isolating and cloning the various chromosomal genes controlling these enzymes, and exploring genetic transfer (exchange) systems. Expression of micrococcal hydrocarbon genes in other organisms should also be evaluated.

  11. Omega-3 long-chain fatty acids strongly induce angiopoietin-like 4 in humans12[S

    PubMed Central

    Brands, Myrte; Sauerwein, Hans P.; Ackermans, Mariette T.; Kersten, Sander; Serlie, Mireille J.

    2013-01-01

    Angiopoietin-like 4 (ANGPTL4) is a regulator of LPL activity. In this study we examined whether different fatty acids have a differential effect on plasma ANGPTL4 levels during hyperinsulinemia in healthy lean males. In 10 healthy lean males, 3 hyperinsulinemic euglycemic clamps were performed during concomitant 6 h intravenous infusion of soybean oil (Intralipid® rich in PUFA), olive oil (Clinoleic® rich in MUFA) and control saline. In 10 other healthy lean males, 2 hyperinsulinemic clamps were performed during infusion of a mixed lipid emulsion containing a mixture of fish oil (FO), medium-chain triglycerides (MCTs), and long-chain triglycerides (LCTs) (FO/MCT/LCT; SMOFlipid®) or saline. FFA levels of approximately 0.5 mmol/l were reached during each lipid infusion. Plasma ANGPTL4 decreased during hyperinsulinemia by 32% (18–52%) from baseline. This insulin-mediated decrease in ANGPTL4 concentrations was partially reduced during concomitant infusion of olive oil and completely blunted during concomitant infusion of soybean oil and FO/MCT/LCT. The reduction in insulin sensitivity was similar between all lipid infusions. In accordance, incubation of rat hepatoma cells with the polyunsaturated fatty acid C22:6 increased ANGPTL4 expression by 70-fold, compared with 27-fold by the polyunsaturated fatty acid C18:2, and 15-fold by the monounsaturated fatty acid C18:1. These results suggest that ANGPTL4 is strongly regulated by fatty acids in humans, and is also dependent on the type of fatty acid. PMID:23319744

  12. Unsaturation of Very-Long-Chain Ceramides Protects Plant from Hypoxia-Induced Damages by Modulating Ethylene Signaling in Arabidopsis

    PubMed Central

    Yu, Lu-Jun; Huang, Li; Chen, Liang; Wang, Feng-Zhu; Xia, Fan-Nv; Zhu, Tian-Ren; Wu, Jian-Xin; Yin, Jian; Liao, Bin; Shi, Jianxin; Zhang, Jian-Hua; Aharoni, Asaph; Yao, Nan; Shu, Wensheng; Xiao, Shi

    2015-01-01

    Lipid remodeling is crucial for hypoxic tolerance in animals, whilst little is known about the hypoxia-induced lipid dynamics in plants. Here we performed a mass spectrometry-based analysis to survey the lipid profiles of Arabidopsis rosettes under various hypoxic conditions. We observed that hypoxia caused a significant increase in total amounts of phosphatidylserine, phosphatidic acid and oxidized lipids, but a decrease in phosphatidylcholine (PC) and phosphatidylethanolamine (PE). Particularly, significant gains in the polyunsaturated species of PC, PE and phosphatidylinositol, and losses in their saturated and mono-unsaturated species were evident during hypoxia. Moreover, hypoxia led to a remarkable elevation of ceramides and hydroxyceramides. Disruption of ceramide synthases LOH1, LOH2 and LOH3 enhanced plant sensitivity to dark submergence, but displayed more resistance to submergence under light than wild type. Consistently, levels of unsaturated very-long-chain (VLC) ceramide species (22:1, 24:1 and 26:1) predominantly declined in the loh1, loh2 and loh3 mutants under dark submergence. In contrast, significant reduction of VLC ceramides in the loh1-1 loh3-1 knockdown double mutant and lacking of VLC unsaturated ceramides in the ads2 mutants impaired plant tolerance to both dark and light submergences. Evidence that C24:1-ceramide interacted with recombinant CTR1 protein and inhibited its kinase activity in vitro, enhanced ER-to-nucleus translocation of EIN2-GFP and stabilization of EIN3-GFP in vivo, suggests a role of ceramides in modulating CTR1-mediated ethylene signaling. The dark submergence-sensitive phenotypes of loh mutants were rescued by a ctr1-1 mutation. Thus, our findings demonstrate that unsaturation of VLC ceramides is a protective strategy for hypoxic tolerance in Arabidopsis. PMID:25822663

  13. Cell proliferation and long chain polyunsaturated fatty acid metabolism in a cell line from southern bluefin tuna (Thunnus maccoyii).

    PubMed

    Scholefield, Andrew M; Schuller, Kathryn A

    2014-07-01

    Southern bluefin tuna (SBT, Thunnus maccoyii) aquaculture is a highly valuable industry, but research on these fish is hampered by strict catch quotas and the limited success of captive breeding. To address these limitations, we have developed a SBT cell line (SBT-E1) and here we report on fatty acid metabolism in this cell line. The SBT-E1 cells proliferated well in standard Leibovitz's L-15 cell culture medium containing fetal bovine serum (FBS) as the source of fatty acids. Decreasing the FBS concentration decreased the cell proliferation. Addition of the C(18) polyunsaturated fatty acids (PUFA) α-linolenic acid (ALA, 18:3n-3) or linoleic acid (LNA, 18:2n-6) to the cell culture medium had little effect on the proliferation of the cells, whereas addition of the long-chain PUFA (LC-PUFA) arachidonic acid (ARA, 20:4n-6), eicosapentaenoic acid (EPA, 20:5n-3) or docosahexaenoic acid (DHA, 22:6n-3) significantly reduced the proliferation of the cells, especially at higher concentrations and especially for DHA. Addition of vitamin E to the culture medium overcame this effect, suggesting that it was due to oxidative stress. The fatty acid profiles of the total lipid from the cells reflected those of the respective culture media with little evidence for desaturation or elongation of any of the fatty acids. The only exceptions were EPA and ARA, which showed substantial elongation to 22:5n-3 and 22:4n-6, respectively, and DHA, which was significantly enriched in the cells compared with the culture medium. The results are discussed in light of the dietary PUFA requirements of SBT in the wild and in aquaculture. PMID:24825740

  14. Long-chain polyunsaturated fatty acids stimulate cellular fatty acid uptake in human placental choriocarcinoma (BeWo) cells.

    PubMed

    Johnsen, G M; Weedon-Fekjaer, M S; Tobin, K A R; Staff, A C; Duttaroy, A K

    2009-12-01

    Supplementation of long-chain polyunsaturated fatty acids (LCPUFAs) is advocated during pregnancy in some countries although very little information is available on their effects on placental ability to take up these fatty acids for fetal supply to which the fetal growth and development are critically dependent. To identify the roles of LCPUFAs on placental fatty acid transport function, we examined the effects of LCPUFAs on the uptake of fatty acids and expression of fatty acid transport/metabolic genes using placental trophoblast cells (BeWo). Following 24 h incubation of these cells with 100 microM of LCPUFAs (arachidonic acid, 20:4n-6, eicosapentaenoic acid, 20:5n-3, or docosahexaenoic acid, 22:6n-3), the cellular uptake of [(14)C] fatty acids was increased by 20-50%, and accumulated fatty acids were preferentially incorporated into phospholipid fractions. Oleic acid (OA, 18:1n-9), on the other hand, could not stimulate fatty acid uptake. LCPUFAs and OA increased the gene expression of ADRP whilst decreased the expression of ASCL3, ACSL4, ACSL6, LPIN1, and FABP3 in these cells. However, LCPUFAs but not OA increased expression of ACSL1 and ACSL5. Since acyl-CoA synthetases are involved in cellular uptake of fatty acids via activation for their channelling to lipid metabolism and/or for storage, the increased expression of ACSL1 and ACLS5 by LCPUFAs may be responsible for the increased fatty acid uptake. These findings demonstrate that LCPUFA may function as an important regulator of general fatty acid uptake in trophoblast cells and may thus have impact on fetal growth and development. PMID:19880178

  15. Long Chain Alcohols Produced by Trichoderma citrinoviride Have Phagodeterrent Activity against the Bird Cherry-Oat Aphid Rhopalosiphum padi.

    PubMed

    Ganassi, Sonia; Grazioso, Pasqualina; De Cristofaro, Antonio; Fiorentini, Fabio; Sabatini, Maria Agnese; Evidente, Antonio; Altomare, Claudio

    2016-01-01

    In this study we report the effects of fungal metabolites isolated from cultures of the fungus Trichoderma citrinoviride ITEM 4484 on the feeding preference of the aphid Rhopalosiphum padi, a major pest of cereal crops. Different phagodeterrent metabolites were purified by a combination of direct and reverse phase column chromatography and thin-layer chromatography. Chemical investigations, by spectroscopic and chemical methods, led to the identification of different long chain primary alcohols (LCOHs) of the general formula R-OH, wherein R is a long, unbranched, unsubstituted, linear aliphatic group. LCOHs have been reported as components of lepidopteran pheromone blends, but their phagodeterrent effect to aphids is herein reported for the first time. The effects of LCOHs on R. padi were studied by behavioral and electrophysiological bioassays. Feeding preference tests that were carried out with winged and wingless morphs of R. padi showed that LCOHs had high phagodeterrent activity and restrained aphids from settling on treated leaves at a concentration as low as 0.15 mM (0.036 g/l). The results of different electrophysiological analyses indicated that taste receptor neurons located on the aphid tarsomeres were involved in the LCOHs perception. Behavioral assays carried out with some commercial agrochemicals, including azadirachtin A, pyrethrum and a mineral oil-based product, in combination with 1-hexadecanol, the LCOH most abundantly produced by T. citrinoviride ITEM 4484, showed that these different active principles could be applied together, resulting in a useful increase of the phagodeterrent effect. The data shown indicate that these compounds can be profitably utilized for novel applications in biotechnical control of aphid pests. Furthermore, the tested LCOHs have no chiral centers and therefore can be obtained with good yield and at low cost through chemical synthesis, as well as from natural sources. PMID:27014220

  16. Long chain polyunsaturated fatty acids alter oxytocin signaling and receptor density in cultured pregnant human myometrial smooth muscle cells.

    PubMed

    Kim, Paul Y; Zhong, Miao; Kim, Yoon-Sun; Sanborn, Barbara M; Allen, Kenneth G D

    2012-01-01

    Epidemiological studies and interventional clinical trials indicate that consumption of long chain n-3 polyunsaturated fatty acids (LC n-3 PUFA) such as docosahexaenoic acid (DHA) lengthen gestational duration. Although the mechanisms are not well understood, prostaglandins (PG) of the 2-series are known to play a role in the initiation and progress of labor. In animal studies, modest DHA provision has been shown to reduce placental and uterine PGE(2) and PGF(2α), matrix metalloproteinase (MMP)-2 and MMP-9 expression, and placental collagenase activity. However, modulation of PG biosynthesis may not account for all the effects of LC n-3 PUFAs in labor. We investigated one potential PG-independent mechanism of LC PUFA action using cultured pregnant human myometrial smooth muscle cells. Our goal was to characterize the effect of LC PUFA treatment on oxytocin signaling, a potent uterotonic hormone involved in labor. The addition of 10 µM-100 µM DHA or arachidonic acid (AA) to the culture media for 48 h resulted in dose dependent enrichment of these fatty acids in membrane lipid. DHA and AA significantly inhibited phosphatidylinositol turnover and [Ca(2+)](i) mobilization with oxytocin stimulation compared to bovine serum albumin control and equimolar oleic acid. DHA and AA significantly reduced oxytocin receptor membrane concentration without altering binding affinity or rate of receptor internalization. These findings demonstrate a role for LC n-3 PUFAs in regulation of oxytocin signaling and provide new insight into additional mechanisms pertaining to reports of dietary fish and fish oil consumption prolonging gestation. PMID:22848573

  17. Theoretical dietary modelling of Australian seafood species to meet long-chain omega 3 fatty acid dietary recommendations

    PubMed Central

    Grieger, Jessica A.; McLeod, Catherine; Chan, Lily; Miller, Michelle D.

    2013-01-01

    Background Several agencies recommend seafood to be consumed 2–3 times per week. In Australia, there is a lack of nutrient composition data for seafood species and it is not known whether including different seafood species in a diet would provide sufficient long-chain omega 3 fatty acids (LC n–3 PUFA) to meet various national recommendations. Objective To utilise recent nutrient composition data for major Australian seafood groups (n=24) with the addition of two tuna options (total n=26) to: (1) determine whether including these species into a diet based on the Australian Guide to Healthy Eating (AGHE) will achieve LC n–3 PUFA recommendations [Adequate Intake (AI: 160 mg/d men, 90 mg/d women)], Suggested Dietary Target (SDT), 500 mg/d Heart Foundation (HF) recommendation and (2) determine the weekly number of servings of seafood to meet recommendations using either lower fat (n=23, <10% total fat) or higher fat (n=3, ≥10% total fat) seafood. Design Two simulation models incorporated all 26 species of seafood or only lower fat seafood into a diet based on the AGHE. Two further models identified the number of servings of lower or higher fat seafood required to meet recommendations. Results Including 2 and 3 servings/week of any seafood would enable 89% of women and 66% of men to meet the AI. Including only lower fat seafood would enable 83% of women and 47% of men to meet the AI. Half a serving/week of higher fat seafood would enable 100% of men and women to meet the AI. Conclusions Including the recommended 2–3 servings of seafood/week requires at least some higher fat seafood to be consumed in order for most men and women to meet the AI. Further messages and nutrition resources are needed which provide options on how to increase intake of LC n–3 PUFA, specifically through consumption of the higher fat seafood. PMID:24179469

  18. Sphingolipid Long-Chain Base Synthesis in Plants (Characterization of Serine Palmitoyltransferase Activity in Squash Fruit Microsomes).

    PubMed Central

    Lynch, D. V.; Fairfield, S. R.

    1993-01-01

    The activity of serine palmitoyltransferase (palmitoyl-coenzyme A [CoA]:L-serine [Ser]-C-palmitoyltransferase [decarboxylating], EC 2.3.1.50), the enzyme catalyzing the first step in the synthesis of the long-chain base required for sphingolipid assembly, has been characterized in a plant system. Enzyme activity in a microsomal membrane fraction from summer squash fruit (Cucurbita pepo L. cv Early Prolific Straightneck) was assayed by monitoring the incorporation of L-[3H]Ser into the chloroform-soluble product, 3-ketosphinganine. Addition of NADPH to the assay system resulted in the conversion of 3-ketosphinganine to sphinganine. The apparent Km for Ser was approximately 1.8 mM. The enzyme exhibited a strong preference for palmitoyl-CoA, with optimal activity at a substrate concentration of 200 [mu]M. Pyridoxal 5[prime]-phosphate was required as a coenzyme. The pH optimum was 7.6, and the temperature optimum was 36 to 40[deg]C. Enzyme activity was greatest in the microsomal fraction obtained by differential centrifugation and was localized to the endoplasmic reticulum using marker enzymes. Two known mechanism-based inhibitors of the mammalian enzyme, L-cycloserine and [beta]-chloro-L-alanine, were effective inhibitors of enzyme activity in squash microsomes. Changes in enzyme activity with size (age) of squash fruit were observed. The results from this study suggest that the properties and catalytic mechanism of Ser palmitoyltransferase from squash are similar to those of the animal, fungal, and bacterial enzyme in most respects. The specific activity of the enzyme in squash microsomes ranged from 0.57 to 0.84 nmol min-1 mg-1 of protein, values 2- to 20-fold higher than those previously reported for preparations from animal tissues. PMID:12232036

  19. Amino acid sequences of two novel long-chain neurotoxins from the venom of the sea snake Laticauda colubrina.

    PubMed

    Kim, H S; Tamiya, N

    1982-11-01

    From the venom of a population of the sea snake Laticauda colubrina from the Solomon Islands, a neurotoxic component, Laticauda colubrina a (toxin Lc a), was isolated in 16.6% (A280) yield. Similarly, from the venom of a population of L. colubrina from the Philippines, a neurotoxic component, Laticauda colubrina b (toxin Lc b), was obtained in 10.0% (A280) yield. The LD50 values of these toxins were 0.12 microgram/g body wt. on intramuscular injection in mice. Toxins Lc a and Lc b were each composed of molecules containing 69 amino acid residues with eight half-cystine residues. The complete amino acid sequences of these two toxins were elucidated. Toxins Lc a and Lc b are different from each other at five positions of their sequences, namely at positions 31 (Phe/Ser), 32 (Leu/Ile), 33 (Lys/Arg), 50 (Pro/Arg) and 53 (Asp/His) (residues in parentheses give the residues in toxins Lc a and Lc b respectively). Toxins Lc a and Lc b have a novel structure in that they have only four disulphide bridges, although the whole amino acid sequences are homologous to those of other known long-chain neurotoxins. It is remarkable that toxins Lc a and Lc b are not coexistent at the detection error of 6% of the other toxin. Populations of Laticauda colubrina from the Solomon Islands and from the Philippines have either toxin Lc a or toxin Lc b and not both of them. PMID:7159381

  20. Associations of maternal long chain polyunsaturated fatty acids, methyl mercury, and infant development in the Seychelles Child Development Nutrition Study

    PubMed Central

    Strain, J.J.; Davidson, Philip W.; Bonham, Maxine P.; Duffy, Emeir M.; Stokes-Riner, Abbie; Thurston, Sally W.; Wallace, Julie M.W.; Robson, Paula J.; Shamlaye, Conrad F.; Georger, Lesley A.; Sloane-Reeves, Jean; Cernichiari, Elsa; Canfield, Richard L.; Cox, Christopher; Huang, Li Shan; Janciuras, Joanne; Myers, Gary J.; Clarkson, Thomas W.

    2008-01-01

    Fish consumption during gestation can provide the fetus with long chain polyunsaturated fatty acids (LCPUFA) and other nutrients essential for growth and development of the brain. However, fish consumption also exposes the fetus to the neurotoxicant, methyl mercury (MeHg). We studied the association between these fetal exposures and early child development in the Seychelles Child Development Nutrition Study (SCDNS). Specifically, we examined a priori models of Ω-3 and Ω-6 LCPUFA measures in maternal serum to test the hypothesis that these LCPUFA families before or after adjusting for prenatal MeHg exposure would reveal associations with child development assessed by the BSID-II at ages 9 and 30 months. There were 229 children with complete outcome and covariate data available for analysis. At 9 months, the PDI was positively associated with total Ω-3 LCPUFA and negatively associated with the ratio of Ω-6/Ω-3 LCPUFA. These associations were stronger in models adjusted for prenatal MeHg exposure. Secondary models suggested that the MeHg effect at 9 months varied by the ratio of Ω-6/Ω-3 LCPUFA. There were no significant associations between LCPUFA measures and the PDI at 30 months. There were significant adverse associations, however, between prenatal MeHg and the 30 month PDI when the LCPUFA measures were included in the regression analysis. The BSID-II Mental Developmental Index (MDI) was not associated with any exposure variable. These data support the potential importance to child development of prenatal availability of Ω-3 LCPUFA present in fish and of LCPUFA in the overall diet. Furthermore, they indicate that the beneficial effects of LCPUFA can obscure the determination of adverse effects of prenatal MeHg exposure in longitudinal observational studies. PMID:18590765

  1. Energetics and kinetics of anaerobic aromatic and fatty acid degradation

    SciTech Connect

    McInerney, M.J.

    1992-11-16

    The kinetics of benzoate degradation by the anaerobic syntrophic bacterium, Syntrophus buswellii, was studied in coculture with Desulfovibrio strain G11. The threshold value for benzoate degradation was dependent on the acetate concentration with benzoate threshold values ranging from 2.4 [mu]M at 20 mM acetate to 30.0 [mu]M at 65 mM acetate. Increasing acetate concentrations also inhibited the rate of benzoate degradation with a apparent K[sub i] for acetate inhibition of 7.0 mM. Lower threshold values were obtained when nitrate rather than sulfate was the terminal electron acceptor. These data are consistent with a thermodynamic explanation for the threshold, and suggest that there is a minimum Gibbs free energy value required for the degradation of benzoate. An acetoacetyl-CoA thiolase has been isolated from Syntrophomonas wolfei; it is apparently a key enzyme controlling the synthesis of poly-B-hydroxyalkanoate from acetyl-CoA in this organism. Kinetic characterization of the acetoacetyl-CoA thiolase from S. wolfei showed that it is similar in its structural, kinetic, and apparent regulatory properties to other biosynthetic acetoacetyl-CoA thiolases from phylogenetically distinct bacteria that synthesize PHA. Intracellular concentrations of CoA and acetyl-CoA are believed to be critical factors regulating the activity of the acetoacetyl-CoA thiolase in S. wolfei. We have also isolated and characterized several new halophilic anaerobic fermentative anaerobes. Phylogenetic analysis indicates that one of these bacteria is a new species in the genus, Haloanaerobium. Two other species appear to be members of the genus, Halobacteroides. Several halophilic acetoclastic methanogenic bacteria have also been isolated and their physiological properties are currently under investigation. We have also isolated an acetate-using dissimilatory iron-reducing bacterium.

  2. Succession of lignocellulolytic bacterial consortia bred anaerobically from lake sediment.

    PubMed

    Korenblum, Elisa; Jiménez, Diego Javier; van Elsas, Jan Dirk

    2016-03-01

    Anaerobic bacteria degrade lignocellulose in various anoxic and organically rich environments, often in a syntrophic process. Anaerobic enrichments of bacterial communities on a recalcitrant lignocellulose source were studied combining polymerase chain reaction-denaturing gradient gel electrophoresis, amplicon sequencing of the 16S rRNA gene and culturing. Three consortia were constructed using the microbiota of lake sediment as the starting inoculum and untreated switchgrass (Panicum virgatum) (acid or heat) or treated (with either acid or heat) as the sole source of carbonaceous compounds. Additionally, nitrate was used in order to limit sulfate reduction and methanogenesis. Bacterial growth took place, as evidenced from 3 to 4 log unit increases in the 16S rRNA gene copy numbers as well as direct cell counts through three transfers on cleaned and reused substrate placed in fresh mineral medium. After 2 days, Aeromonas bestiarum-like organisms dominated the enrichments, irrespective of the substrate type. One month later, each substrate revealed major enrichments of organisms affiliated with different species of Clostridium. Moreover, only the heat-treated substrate selected Dysgonomonas capnocytophagoides-affiliated bacteria (Bacteroidetes). Towards the end of the experiment, members of the Proteobacteria (Aeromonas, Rhizobium and/or Serratia) became dominant in all three types of substrates. A total of 160 strains was isolated from the enrichments. Most of the strains tested (78%) were able to grow anaerobically on carboxymethyl cellulose and xylan. The final consortia yield attractive biological tools for the depolymerization of recalcitrant lignocellulosic materials and are proposed for the production of precursors of biofuels. PMID:26875750

  3. Metatranscriptome of an Anaerobic Benzene-Degrading, Nitrate-Reducing Enrichment Culture Reveals Involvement of Carboxylation in Benzene Ring Activation

    PubMed Central

    Luo, Fei; Gitiafroz, Roya; Devine, Cheryl E.; Gong, Yunchen; Hug, Laura A.; Raskin, Lutgarde

    2014-01-01

    The enzymes involved in the initial steps of anaerobic benzene catabolism are not known. To try to elucidate this critical step, a metatranscriptomic analysis was conducted to compare the genes transcribed during the metabolism of benzene and benzoate by an anaerobic benzene-degrading, nitrate-reducing enrichment culture. RNA was extracted from the mixed culture and sequenced without prior mRNA enrichment, allowing simultaneous examination of the active community composition and the differential gene expression between the two treatments. Ribosomal and mRNA sequences attributed to a member of the family Peptococcaceae from the order Clostridiales were essentially only detected in the benzene-amended culture samples, implicating this group in the initial catabolism of benzene. Genes similar to each of two subunits of a proposed benzene-carboxylating enzyme were transcribed when the culture was amended with benzene. Anaerobic benzoate degradation genes from strict anaerobes were transcribed only when the culture was amended with benzene. Genes for other benzoate catabolic enzymes and for nitrate respiration were transcribed in both samples, with those attributed to an Azoarcus species being most abundant. These findings indicate that the mineralization of benzene starts with its activation by a strict anaerobe belonging to the Peptococcaceae, involving a carboxylation step to form benzoate. These data confirm the previously hypothesized syntrophic association between a benzene-degrading Peptococcaceae strain and a benzoate-degrading denitrifying Azoarcus strain for the complete catabolism of benzene with nitrate as the terminal electron acceptor. PMID:24795366

  4. Microbial Ecology in Anaerobic Digestion at Agitated and Non-Agitated Conditions

    PubMed Central

    Tian, Zhuoli; Cabrol, Léa; Ruiz-Filippi, Gonzalo; Pullammanappallil, Pratap

    2014-01-01

    To investigate the distribution and dynamics of microbial community in anaerobic digestion at agitated and non-agitated condition, 454 pyrosequencing of 16s rRNA was conducted. It revealed the distinct community compositions between the two digesters and their progressive shifting over time. Methanogens and syntrophic bacteria were found much less abundant in the agitated digester, which was mainly attributed to the presence of bacterial genera Acetanaerobacterium and Ruminococcus with relatively high abundance. The characterization of the microbial community corroborated the digestion performance affected at the agitated condition, where lower methane yield and delayed methane production rate were observed. This was further verified by the accumulation of propionic acid in the agitated digester. PMID:25313520

  5. Energetics and kinetics of anaerobic aromatic and fatty acid degradation. Progress report, November 1992--November 1993

    SciTech Connect

    McInerney, M.J.

    1993-11-12

    The kinetics of benzoate degradation by the anaerobic syntrophic bacterium, Syntrophus buswellii, in coculture with different sulfate reducers was studied with sulfate or nitrate as the electron acceptor. A threshold value for benzoate degradation dependent on the acetate concentration was observed with sulfate, but not nitrate, as the electron acceptor. No threshold was observed in tricultures containing an acetate-using sulfate reducer. The addition of the acetate-using sulfate reducer to cocultures that had degraded benzoate to its threshold value resulted in further degradation of benzoate to levels below the analytical detection limit (ca. 200 nM). These data are consistent with a thermodynamic explanation for the threshold, and exclude the possibility that the threshold was the result of the inhibitory action of the undissociated form of acetate.

  6. Association between fish consumption, long chain omega 3 fatty acids, and risk of cerebrovascular disease: systematic review and meta-analysis

    PubMed Central

    Chowdhury, Rajiv; Stevens, Sarah; Gorman, Donal; Pan, An; Warnakula, Samantha; Chowdhury, Susmita; Ward, Heather; Johnson, Laura; Crowe, Francesca; Hu, Frank B

    2012-01-01

    Objective To clarify associations of fish consumption and long chain omega 3 fatty acids with risk of cerebrovascular disease for primary and secondary prevention. Design Systematic review and meta-analysis. Data sources Studies published before September 2012 identified through electronic searches using Medline, Embase, BIOSIS, and Science Citation Index databases. Eligibility criteria Prospective cohort studies and randomised controlled trials reporting on associations of fish consumption and long chain omega 3 fatty acids (based on dietary self report), omega 3 fatty acids biomarkers, or supplementations with cerebrovascular disease (defined as any fatal or non-fatal ischaemic stroke, haemorrhagic stroke, cerebrovascular accident, or transient ischaemic attack). Both primary and secondary prevention studies (comprising participants with or without cardiovascular disease at baseline) were eligible. Results 26 prospective cohort studies and 12 randomised controlled trials with aggregate data on 794 000 non-overlapping people and 34 817 cerebrovascular outcomes were included. In cohort studies comparing categories of fish intake the pooled relative risk for cerebrovascular disease for 2-4 servings a week versus ≤1 servings a week was 0.94 (95% confidence intervals 0.90 to 0.98) and for ≥5 servings a week versus 1 serving a week was 0.88 (0.81 to 0.96). The relative risk for cerebrovascular disease comparing the top thirds of baseline long chain omega 3 fatty acids with the bottom thirds for circulating biomarkers was 1.04 (0.90 to 1.20) and for dietary exposures was 0.90 (0.80 to 1.01). In the randomised controlled trials the relative risk for cerebrovascular disease in the long chain omega 3 supplement compared with the control group in primary prevention trials was 0.98 (0.89 to 1.08) and in secondary prevention trials was 1.17 (0.99 to 1.38). For fish or omega 3 fatty acids the estimates for ischaemic and haemorrhagic cerebrovascular events were broadly

  7. Elemental copper nanoparticle toxicity to different trophic groups involved in anaerobic and anoxic wastewater treatment processes.

    PubMed

    Gonzalez-Estrella, Jorge; Puyol, Daniel; Gallagher, Sara; Sierra-Alvarez, Reyes; Field, Jim A

    2015-04-15

    Elemental copper nanoparticles (Cu(0) NPs) are potentially inhibitory to the different key microbial trophic groups involved in biological wastewater treatment processes. Cu-based NPs are known to be toxic to methanogens at low concentrations. However, very little is known about the toxic effect of Cu(0) NPs on other microbial groups involved in either upper trophic levels of anaerobic digestion or anoxic nitrogen removal processes. This study evaluated the toxicity of Cu(0) NPs to glucose fermentation, syntrophic propionate oxidation and denitrification in shaken batch bioassays with soluble substrates. Batch experiments were also supplemented with CuCl2 to evaluate the inhibitory impact of soluble Cu(II) ions. Syntrophic propionate oxidation and glucose fermentation were the least and most inhibited processes with inhibition constant (Ki) values of 0.202 and 0.047 mM of added Cu(0) NPs, respectively. Further analyses revealed that the Ki values calculated as a function of the free soluble Cu concentration were <0.003 mM for every biological process tested and most of these Ki values were similar in order of magnitude regardless of whether the Cu source was CuCl2 or Cu(0) NPs. The results taken as a whole indicate that Cu(0) NPs are toxic to all the microbial processes studied. Therefore, Cu(0) NPs can potentially be an important inhibitor of anaerobic wastewater treatment processes that rely on these trophic groups. The evidence suggests that the inhibitory impact of Cu(0) NPs was mainly due to the release of toxic Cu(II) ions originating from the corrosion and dissolution of Cu(0) NPs. PMID:25634735

  8. Long-Chain Fatty Acid Combustion Rate Is Associated with Unique Metabolite Profiles in Skeletal Muscle Mitochondria

    PubMed Central

    Seifert, Erin L.; Fiehn, Oliver; Bezaire, Véronic; Bickel, David R.; Wohlgemuth, Gert; Adams, Sean H.; Harper, Mary-Ellen

    2010-01-01

    Background/Aim Incomplete or limited long-chain fatty acid (LCFA) combustion in skeletal muscle has been associated with insulin resistance. Signals that are responsive to shifts in LCFA β-oxidation rate or degree of intramitochondrial catabolism are hypothesized to regulate second messenger systems downstream of the insulin receptor. Recent evidence supports a causal link between mitochondrial LCFA combustion in skeletal muscle and insulin resistance. We have used unbiased metabolite profiling of mouse muscle mitochondria with the aim of identifying candidate metabolites within or effluxed from mitochondria and that are shifted with LCFA combustion rate. Methodology/Principal Findings Large-scale unbiased metabolomics analysis was performed using GC/TOF-MS on buffer and mitochondrial matrix fractions obtained prior to and after 20 min of palmitate catabolism (n = 7 mice/condition). Three palmitate concentrations (2, 9 and 19 µM; corresponding to low, intermediate and high oxidation rates) and 9 µM palmitate plus tricarboxylic acid (TCA) cycle and electron transport chain inhibitors were each tested and compared to zero palmitate control incubations. Paired comparisons of the 0 and 20 min samples were made by Student's t-test. False discovery rate were estimated and Type I error rates assigned. Major metabolite groups were organic acids, amines and amino acids, free fatty acids and sugar phosphates. Palmitate oxidation was associated with unique profiles of metabolites, a subset of which correlated to palmitate oxidation rate. In particular, palmitate oxidation rate was associated with distinct changes in the levels of TCA cycle intermediates within and effluxed from mitochondria. Conclusions/Significance This proof-of-principle study establishes that large-scale metabolomics methods can be applied to organelle-level models to discover metabolite patterns reflective of LCFA combustion, which may lead to identification of molecules linking muscle fat

  9. Modulation of blood oxylipin levels by long-chain omega-3 fatty acid supplementation in hyper- and normolipidemic men

    PubMed Central

    Schuchardt, Jan Philipp; Schmidt, Simone; Kressel, Gaby; Willenberg, Ina; Hammock, Bruce D; Hahn, Andreas; Schebb, Nils Helge

    2014-01-01

    Introduction Long chain omega-3 polyunsaturated fatty acids (LC n-3 PUFA) such as EPA and DHA have been shown to possess beneficial health effects, and it is believed that many of their effects are mediated by their oxygenated products (oxylipins). Recently, we have shown that serum levels of several hydroxy, epoxy, and dihydroxy FAs are dependent on the individual status of the parent FAs in a cohort of normo- and hyperlipidemic subjects. So far, the effect of an increased dietary LC n-3 PUFA intake on hydroxy, epoxy, and dihydroxy FA levels has not been investigated in subjects with mild combined hyperlipidemia. Subjects and Methods In the present study, we compared oxylipin patterns of 10 hyperlipidemic (cholesterol >200 mg/dl; triglyceride >150 mg/ml) and 10 normolipidemic men in response to twelve weeks of LC n-3 PUFA intake (1.14 g DHA and 1.56 g EPA). Levels of 44 free hydroxy, epoxy and dihydroxy FAs were analyzed in serum by LC-MS. Additionally, oxylipin levels were compared with their parent PUFA levels in erythrocyte membranes; a biomarker for the individual PUFA status. Results Differences in the oxylipin pattern between normo- and hyperlipidemic subjects were minor before and after treatment. In all subjects, levels of EPA-derived oxylipins (170–4,800 pM) were considerably elevated after LC n-3 PUFA intake (150–1,400 %), the increase of DHA-derived oxylipins (360–3,900 pM) was less pronounced (30–130 %). The relative change of EPA in erythrocyte membranes is strongly correlated (r ≥ 0.5; p<0.05) with the relative change of corresponding epoxy and dihydroxy FA serum levels. The effect on arachidonic acid (AA)-derived oxylipin levels (140–27,100 pM) was inconsistent. Discussion and Conclusions The dietary LC PUFA composition has a direct influence on the endogenous oxylipin profile, including several highly biological active EPA- and DHA-derived lipid mediators. The shift in oxylipin pattern appears to be dependent on the initial LC PUFA

  10. The impact of dietary long-chain polyunsaturated fatty acids on bone and cartilage in gilts and sows.

    PubMed

    O'Connor-Robison, C I; Spencer, J D; Orth, M W

    2014-10-01

    Dietary long-chain PFO including arachidonic acid (ARA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) are precursors for several inflammatory mediators. The objective of this study was to characterize the effects of dietary PFO supplementation on bone, cartilage, and synovial fluid in 2 ages of pigs. Sows and gilts were fed either control corn/soybean meal based diets or the control diet supplemented with PFO from Gromega (PFO; JBS United, Sheridan, IN). Sows were fed their diets for 24.5 mo and slaughtered at 43 mo while gilts were fed their diets from weaning until slaughter at 111 kg. Cartilage was harvested from both humeroulnar joints of 14 sows (7/treatment) and 16 gilts (8/treatment) within 30 h of slaughter for fatty acid analysis and explant cultures. Synovial fluid was collected from the carpal joints of each pig postmortem. The right fused radius/ulna was collected for computed tomography (CT) analysis. Cortical width and density were determined and trabecular density was measured at the distal radius. Cartilage explants were allocated to 24-well culture plates with 2 discs per well and cultured over 72 h at 37°C in serum-free Dulbecco's modified Eagle's medium: nutrient mixture F-12 (Ham) medium. Six wells/pig were treated with 10 ng/mL of recombinant porcine interleukin-1 (rpIL-1). At 24, 48, and 72 h of culture, media were removed and reserved for analysis of proteoglycans, nitric oxide (NO), and PGE2 concentrations. The CT scans of the radius/ulna from gilts revealed no differences for cortical width and bone density. Sows fed PFO had greater cortical width of the proximal ulna (P < 0.05) and decreased cortical width of the distal radius (P < 0.05). Sows fed PFO had increased DHA (P < 0.01) and a decrease in the omega-6 to omega-3 ratio (P < 0.05) in cartilage. Gilts fed PFO had increased DHA (P < 0.01), C22:1 (P < 0.01), and docosapentaenoic acid (P < 0.01) and a tendency for increased EPA (P = 0.093) concentrations in cartilage

  11. N2O5 Hydrolysis on a Liquid Surface Coated by Long Chain Fatty Acid and Alcohol monolayers

    NASA Astrophysics Data System (ADS)

    Cosman, L. M.; Knopf, D. A.; Bertram, A. K.

    2006-12-01

    Heterogeneous reactions between aerosol particles and gas phase species play a crucial role in the atmosphere and can influence the composition of the atmosphere. Heterogeneous reactions of N2O5 with aqueous particles have a significant effect on the global NOx budget, which influences tropospheric concentrations of O3 and OH. The hydrolysis of N2O5 on sulfuric acid particles has been studied extensively and is found to be very efficient. However, surface active organic molecules are common constituents of aqueous atmospheric particles and their effect on heterogeneous reactions is still poorly understood. Previous studies have shown that organic coatings on atmospheric droplets can change the uptake of gaseous species substantially. It is important to know heterogeneous reaction rates for the hydrolysis of N2O5 on organic coated aqueous particles in order to accurately predict the oxidative capacity of the troposphere. Here we present the investigation of heterogeneous reactions of N2O5 on aqueous sulfuric acid coated by an organic monolayer. A new parallel plate flow reactor (PPFR) has been developed to allow heterogeneous reactions to be studied on a planar aqueous surface coated with an organic monolayer. In addition, a theoretical framework has been developed to derive heterogeneous kinetics taking into consideration the effects of diffusion. The PPFR coupled to a chemical ionization mass spectrometer was employed to measure reactive uptake coefficients for N2O5 on aqueous H2SO4 solutions coated with long chain fatty acids and alcohols. One key feature of this new technique is the ability to characterize the monolayer prior to kinetic measurements to determine the surface pressure and packing density of the organic molecules on the surface. Monolayers of octadecanol, hexadecanol, stearic acid, and phytanic acid were studied on 60 wt % H2SO4 solutions at 274 K. It was found that a monolayer of octadecanol reduced the uptake coefficient of N2O5 with H2SO4 by

  12. Towards the Industrial Production of Omega-3 Long Chain Polyunsaturated Fatty Acids from a Genetically Modified Diatom Phaeodactylum tricornutum

    PubMed Central

    Hamilton, Mary L.; Warwick, Joanna; Terry, Anya; Allen, Michael J.; Napier, Johnathan A.; Sayanova, Olga

    2015-01-01

    The marine diatom Phaeodactylum tricornutum can accumulate up to 30% of the omega-3 long chain polyunsaturated fatty acid (LC-PUFA) eicosapentaenoic acid (EPA) and, as such, is considered a good source for the industrial production of EPA. However, P. tricornutum does not naturally accumulate significant levels of the more valuable omega-3 LC-PUFA docosahexaenoic acid (DHA). Previously, we have engineered P. tricornutum to accumulate elevated levels of DHA and docosapentaenoic acid (DPA) by overexpressing heterologous genes encoding enzyme activities of the LC-PUFA biosynthetic pathway. Here, the transgenic strain Pt_Elo5 has been investigated for the scalable production of EPA and DHA. Studies have been performed at the laboratory scale on the cultures growing in up to 1 L flasks a 3.5 L bubble column, a 550 L closed photobioreactor and a 1250 L raceway pond with artificial illumination. Detailed studies were carried out on the effect of different media, carbon sources and illumination on omega-3 LC-PUFAs production by transgenic strain Pt_Elo5 and wild type P. tricornutum grown in 3.5 L bubble columns. The highest content of DHA (7.5% of total fatty acids, TFA) in transgenic strain was achieved in cultures grown in seawater salts, Instant Ocean (IO), supplemented with F/2 nutrients (F2N) under continuous light. After identifying the optimal conditions for omega-3 LC-PUFA accumulation in the small-scale experiments we compared EPA and DHA levels of the transgenic strain grown in a larger fence-style tubular photobioreactor and a raceway pond. We observed a significant production of DHA over EPA, generating an EPA/DPA/DHA profile of 8.7%/4.5%/12.3% of TFA in cells grown in a photobioreactor, equivalent to 6.4 μg/mg dry weight DHA in a mid-exponentially growing algal culture. Omega-3 LC-PUFAs production in a raceway pond at ambient temperature but supplemented with artificial illumination (110 μmol photons m-2s-1) on a 16:8h light:dark cycle, in natural seawater

  13. Optimisation of stir-bar sorptive extraction (SBSE), targeting medium and long-chain free fatty acids in cooked ham exudates.

    PubMed

    Benet, Iu; Ibañez, Carles; Guàrdia, Maria Dolors; Solà, Josep; Arnau, Jacint; Roura, Eugeni

    2015-10-15

    The purpose of our research was to optimise the extraction conditions of the stir-bar sorptive extraction (SBSE) targeting the identification of lipid compounds particularly medium and long-chain free fatty acids in cooked cured pork ham exudates. The analytical conditions of extraction (including sample volume, extraction time, stirring speed, pH and dilution of the sample) were checked using the Simplex method approach. As a result of the SBSE optimisation, improved detection limits and linear ranges for hexanoic, heptanoic, octanoic, nonanoic, decanoic, dodecanoic and tetradecanoic fatty acids were obtained. When comparing results with those obtained by the commonly used SPME methodology, optimisation of SBSE achieved better results for volatile compounds of low volatility, such as medium and long-chain free fatty acids, whereas compounds with high volatility and polarity were only detected by SPME. SBSE also confirmed its potential as a tool to help identify undesirable contaminants/residues in meat products. PMID:25952843

  14. Fabrication and spectroscopic properties of Langmuir Blodgett films of novel zinc complexes with long chain mono (hexadecyl, octadecyl, eicosyl, and docosyl) phthalate

    NASA Astrophysics Data System (ADS)

    Xu, Bing; Yan, Bing

    2007-08-01

    In this paper, some novel long chain amphiphillic monoester molecules were designed to afford double functions: film-formation and luminescent sensitization. Subsequently, organized molecular films of zinc complexes with these functional ligands formulated as ZnL 2 were fabricated by the Langmuir-Blodgett film (LB) technology, where L denoted the long chain carboxylic ligands monohexadecyl phthalate (16-Phth), monooctadecyl phthalate (18-Phth), monoeicosyl phthalate (20-Phth) and monodocosyl phthalate (22-Phth). The average molecular area was obtained according to the π-A isotherms. The layer structure of the LB films was demonstrated by low-angle X-ray diffraction and the average layer spacing were obtained according to the Bragg equation. The characteristic luminescence behaviors of LB films have been discussed compared with those of their corresponding solid complexes.

  15. Draft Genome Sequence of Syntrophomonas wolfei subsp. methylbutyratica Strain 4J5T (JCM 14075), a Mesophilic Butyrate- and 2-Methylbutyrate-Degrading Syntroph

    PubMed Central

    Nobu, Masaru K.; Tamaki, Hideyuki; Kamagata, Yoichi; Liu, Wen-Tso

    2016-01-01

    Syntrophomonas wolfei subsp. methylbutyratica strain 4J5T (=JCM 14075T) is a mesophilic bacterium capable of degrading butyrate and 2-methylbutyrate through syntrophic cooperation with a partner methanogen. The draft genome sequence is 3.2 Mb, with a G+C content of 45.5%. PMID:26941138

  16. Inhibition of serine palmitoyltransferase in vitro and long-chain base biosynthesis in intact Chinese hamster ovary cells by. beta. -chloroalanine

    SciTech Connect

    Medlock, K.A.; Merrill, A.H. Jr.

    1988-09-06

    The effects of ..beta..-chloroalanine (..beta..-Cl-alanine) on the serine palmitoyltransferase activity and the de novo biosynthesis of sphinganine and sphingenine were investigated in vitro with rat liver microsomes and in vivo with intact Chinese hamster ovary (CHO) cells. The inhibition in vitro was rapid, irreversible, and concentration and time dependent and apparently involved the active site because inactivation only occurred with ..beta..-Cl-L-alanine and was blocked by L-serine. These are characteristics of mechanism-based (suicide) inhibition. Serine palmitoyltransferase (SPT) was also inhibited when intact CHO cells were incubated with ..beta..-Cl-alanine and this treatment inhibited (/sup 14/C)serine incorporation into long-chain bases by intact cells. The concentration dependence of the loss of SPT activity and of long-chain base synthesis was identical. The effects of ..beta..-Cl-alanine appeared to occur with little perturbation of other cell functions: the cells exhibited no loss in cell viability, (/sup 14/C)serine uptake was not blocked, total lipid biosynthesis from (/sup 14/C)acetic acid was not decreased (nor was the appearance of radiolabel in cholesterol and phosphatidylcholine), and (/sup 3/H)thymidine incorporation into DNA was not affected. There appeared to be little effect on protein synthesis based on the incorporation of (/sup 3/H)leucine, which was only decreased by 14%. Although ..beta..-Cl-L-alanine is known to inhibit other pyridoxal 5'-phosphate dependent enzymes, alanine and aspartate transaminases were not inhibited under these conditions. These results establish the close association between the activity of serine palmitoyltransferase and the cellular rate of long-chain base formation and indicate that ..beta..-Cl-alanine and other mechanism-based inhibitors might be useful to study alterations in cellular long-chain base synthesis.

  17. X-ray characterization of self-assembled long-chain phosphatidylcholine/bile salt/silica mesostructured films with nanoscale homogeneity.

    PubMed

    Dunphy, Darren R; Garcia, Fred L; Jiang, Zhang; Strzalka, Joseph; Wang, Jin; Brinker, C Jeffrey

    2011-02-14

    A bile salt (sodium taurodeoxycholate, NaTDC) was used to prevent phase separation between silica and lipid in self-assembled long-chain diacyl phosphatidylcholine/SiO(2) films. Phase diagrams for NaTDC/didecanoyl phosphatidylcholine/SiO(2) and NaTDC/egg phosphatidylcholine/SiO(2) films were investigated through grazing-incidence small-angle X-ray scattering at a synchrotron source. PMID:21135947

  18. Associations of long-chain ω-3 fatty acids and fish intake with endometrial cancer risk in the VITamins And Lifestyle cohort123

    PubMed Central

    Brasky, Theodore M; Neuhouser, Marian L; Cohn, David E; White, Emily

    2014-01-01

    Background: Inflammation plays an important role in endometrial cancer etiology. Long-chain ω-3 (n−3) polyunsaturated fatty acids (PUFAs), derived from marine sources, are thought to be antiinflammatory; however, several studies of fish consumption suggest an increase in risk. Objective: This study examined whether intakes of long-chain ω-3 PUFAs, including eicosapentaenoic acid (EPA; 20:5ω-3) and docosahexaenoic acid (DHA; 22:6ω-3), from diet and supplements and intake of fish are associated with endometrial cancer risk. Design: Between 2000 and 2002, 22,494 women aged 50–76 y, living in western Washington State, were recruited to the VITamins And Lifestyle cohort study. Incident endometrial cancers (n = 263) were identified through the Surveillance, Epidemiology, and End Results cancer registry after 9 y of follow-up. Multivariable-adjusted HRs and 95% CIs for the association of intakes of individual long-chain ω-3 PUFAs and fish with endometrial cancer risk were estimated by using Cox proportional hazards. Results: Women in the highest compared with the lowest quintile of dietary EPA + DHA intake had a 79% increased risk of endometrial cancer (95% CI: 16%, 175%; P-trend = 0.026). Results were similar for EPA and DHA measured individually and for fish intake. When data were stratified by body mass index (in kg/m2; <25 or ≥25), increases in risk of long-chain ω-3 PUFAs were restricted to overweight and obese women, and statistically significant reductions in risk were observed for normal-weight women. Conclusions: The overall increased risk reported here confirms the findings of several prior observational studies of fish intake, which observed similar increases in risk. Randomized trials are needed to confirm these findings. PMID:24500149

  19. Identification of an arylalkylamine N-acyltransferase from Drosophila melanogaster that catalyzes the formation of long-chain N-acylserotonins

    PubMed Central

    Dempsey, Daniel R.; Jeffries, Kristen A.; Anderson, Ryan L.; Carpenter, Anne-Marie; Ospina, Santiago Rodriguez; Merkler, David J.

    2014-01-01

    Arylalkylamine N-acyltransferase-like 22 (AANATL2) from Drosophila melanogaster was expressed and shown to catalyze the formation of long-chain N-acylserotonins and N-acydopamines. Subsequent identification of endogenous amounts of N-acylserotonins and colocalization of these fatty acid amides and AANATL2 transcripts gives supporting evidence that AANATL2 has a role in the biosynthetic formation of these important cell signalling lipids. PMID:24444601

  20. Long-chain SFA at the sn-1, 3 positions of TAG reduce body fat deposition in C57BL/6 mice.

    PubMed

    Gouk, Shiou Wah; Cheng, Sit Foon; Mok, Josephine Shiueh Lian; Ong, Augustine Soon Hock; Chuah, Cheng Hock

    2013-12-14

    The present study aimed to determine the effect of positional distribution of long-chain SFA in TAG, especially at the sn-1, 3 positions, on fat deposition using the C57BL/6 mouse model. Throughout the 15 weeks of the study, mice were fed with diets fortified with palm olein (POo), chemically interesterified POo (IPOo) and soyabean oil (SOY). Mice receiving the SOY-enriched diet gained significantly higher amounts of subcutaneous fat (P= 0·011) and total fat (P= 0·013) compared with the POo group, despite similar body mass gain being recorded. During normalisation with food consumption to obtain the fat:feed ratio, mice fed with the POo-enriched diet exhibited significantly lower visceral (P= 0·044), subcutaneous (P= 0·006) and total (P= 0·003) fat:feed than those fed with the SOY-enriched diet. It is noteworthy that mice fed with the IPOo-enriched diet gained 14·3 % more fat per food consumed when compared with the POo group (P= 0·013), despite their identical total fatty acid compositions. This was mainly attributed to the higher content of long-chain SFA at the sn-1, 3 positions of TAG in POo, which results in delayed absorption after deacylation as evidenced by the higher amounts of long-chain SFA excreted in the faeces of mice fed with the POo-enriched diet. Negative correlations were found between the subcutaneous, visceral as well as total fat accretion per food consumption and the total SFA content at the sn-1, 3 positions, while no relationships were found for MUFA and PUFA. The present results show that the positional distribution of long-chain SFA exerts a more profound effect on body fat accretion than the total SFA content. PMID:23756564

  1. Impact of Ammonium on Syntrophic Organohalide-Respiring and Fermenting Microbial Communities.

    PubMed

    Delgado, Anca G; Fajardo-Williams, Devyn; Kegerreis, Kylie L; Parameswaran, Prathap; Krajmalnik-Brown, Rosa

    2016-01-01

    Syntrophic interactions between organohalide-respiring and fermentative microorganisms are critical for effective bioremediation of halogenated compounds. This work investigated the effect of ammonium concentration (up to 4 g liter(-1) NH4 (+)-N) on trichloroethene-reducing Dehalococcoides mccartyi and Geobacteraceae in microbial communities fed lactate and methanol. We found that production of ethene by D. mccartyi occurred in mineral medium containing ≤2 g liter(-1) NH4 (+)-N and in landfill leachate. For the partial reduction of trichloroethene (TCE) to cis-dichloroethene (cis-DCE) at ≥1 g liter(-1) NH4 (+)-N, organohalide-respiring dynamics shifted from D. mccartyi and Geobacteraceae to mainly D. mccartyi. An increasing concentration of ammonium was coupled to lower metabolic rates, longer lag times, and lower gene abundances for all microbial processes studied. The methanol fermentation pathway to acetate and H2 was conserved, regardless of the ammonium concentration provided. However, lactate fermentation shifted from propionic to acetogenic at concentrations of ≥2 g liter(-1) NH4 (+)-N. Our study findings strongly support a tolerance of D. mccartyi to high ammonium concentrations, highlighting the feasibility of organohalide respiration in ammonium-contaminated subsurface environments. IMPORTANCE Contamination with ammonium and chlorinated solvents has been reported in numerous subsurface environments, and these chemicals bring significant challenges for in situ bioremediation. Dehalococcoides mccartyi is able to reduce the chlorinated solvent trichloroethene to the nontoxic end product ethene. Fermentative bacteria are of central importance for organohalide respiration and bioremediation to provide D. mccartyi with H2, their electron donor, acetate, their carbon source, and other micronutrients. In this study, we found that high concentrations of ammonium negatively correlated with rates of trichloroethene reductive dehalogenation and

  2. Impact of Ammonium on Syntrophic Organohalide-Respiring and Fermenting Microbial Communities

    PubMed Central

    Fajardo-Williams, Devyn; Kegerreis, Kylie L.; Parameswaran, Prathap

    2016-01-01

    ABSTRACT Syntrophic interactions between organohalide-respiring and fermentative microorganisms are critical for effective bioremediation of halogenated compounds. This work investigated the effect of ammonium concentration (up to 4 g liter−1 NH4+-N) on trichloroethene-reducing Dehalococcoides mccartyi and Geobacteraceae in microbial communities fed lactate and methanol. We found that production of ethene by D. mccartyi occurred in mineral medium containing ≤2 g liter−1 NH4+-N and in landfill leachate. For the partial reduction of trichloroethene (TCE) to cis-dichloroethene (cis-DCE) at ≥1 g liter−1 NH4+-N, organohalide-respiring dynamics shifted from D. mccartyi and Geobacteraceae to mainly D. mccartyi. An increasing concentration of ammonium was coupled to lower metabolic rates, longer lag times, and lower gene abundances for all microbial processes studied. The methanol fermentation pathway to acetate and H2 was conserved, regardless of the ammonium concentration provided. However, lactate fermentation shifted from propionic to acetogenic at concentrations of ≥2 g liter−1 NH4+-N. Our study findings strongly support a tolerance of D. mccartyi to high ammonium concentrations, highlighting the feasibility of organohalide respiration in ammonium-contaminated subsurface environments. IMPORTANCE Contamination with ammonium and chlorinated solvents has been reported in numerous subsurface environments, and these chemicals bring significant challenges for in situ bioremediation. Dehalococcoides mccartyi is able to reduce the chlorinated solvent trichloroethene to the nontoxic end product ethene. Fermentative bacteria are of central importance for organohalide respiration and bioremediation to provide D. mccartyi with H2, their electron donor, acetate, their carbon source, and other micronutrients. In this study, we found that high concentrations of ammonium negatively correlated with rates of trichloroethene reductive dehalogenation and

  3. Resting state electroencephalographic correlates with red cell long-chain fatty acids, memory performance and age in adolescent boys with attention deficit hyperactivity disorder.

    PubMed

    Sumich, Alexander; Matsudaira, Toshiko; Gow, Rachel V; Ibrahimovic, Almira; Ghebremeskel, Kebreab; Crawford, Michael; Taylor, Eric

    2009-12-01

    Abnormal fatty acid status has been implicated in the aetiology of attention deficit hyperactivity disorder (ADHD). Delayed maturation in ADHD may result in raised frontal low frequency (theta) electroencephalographic activity (EEG) and a reduction in posterior high frequency (beta, alpha) activity. The current study used sequential linear regression to investigate the association between age, resting-state EEG and levels of long-chain polyunsaturated omega-3 and omega-6 fatty acids in red blood cells in 46 adolescent boys with ADHD symptoms. Docosahexaenoic acid (DHA) levels were positively associated with fast frequency activity: alpha during eyes-open and beta during eyes-closed conditions. Frontal theta activity during both eyes-open and eyes-closed conditions was inversely associated with age and positively associated with eicosapentaenoic acid (EPA) levels. Alpha activity correlated positively with performance on fluency for categories (semantic memory). Theta activity correlated inversely with performance on delayed (25 min) verbal memory (recall + recognition/2). No associations were observed between long-chain omega-6 and EEG measures. Results support differential associations for DHA and EPA with fast and slow EEG activity respectively. Results support EEG activity as an objective biomarker of neural function associated with long-chain omega-3 fatty acids in ADHD. PMID:19627997

  4. Real-Time Tracking of BODIPY-C12 Long-Chain Fatty Acid in Human Term Placenta Reveals Unique Lipid Dynamics in Cytotrophoblast Cells

    PubMed Central

    Louey, Samantha; Varlamov, Oleg; Thornburg, Kent

    2016-01-01

    While the human placenta must provide selected long-chain fatty acids to support the developing fetal brain, little is known about the mechanisms underlying the transport process. We tracked the movement of the fluorescently labeled long-chain fatty acid analogue, BODIPY-C12, across the cell layers of living explants of human term placenta. Although all layers took up the fatty acid, rapid esterification of long-chain fatty acids and incorporation into lipid droplets was exclusive to the inner layer cytotrophoblast cells rather than the expected outer syncytiotrophoblast layer. Cytotrophoblast is a progenitor cell layer previously relegated to a repair role. As isolated cytotrophoblasts differentiated into syncytialized cells in culture, they weakened their lipid processing capacity. Syncytializing cells suppress previously active genes that regulate fatty-acid uptake (SLC27A2/FATP2, FABP4, ACSL5) and lipid metabolism (GPAT3, LPCAT3). We speculate that cytotrophoblast performs a previously unrecognized role in regulating placental fatty acid uptake and metabolism. PMID:27124483

  5. Real-Time Tracking of BODIPY-C12 Long-Chain Fatty Acid in Human Term Placenta Reveals Unique Lipid Dynamics in Cytotrophoblast Cells.

    PubMed

    Kolahi, Kevin; Louey, Samantha; Varlamov, Oleg; Thornburg, Kent

    2016-01-01

    While the human placenta must provide selected long-chain fatty acids to support the developing fetal brain, little is known about the mechanisms underlying the transport process. We tracked the movement of the fluorescently labeled long-chain fatty acid analogue, BODIPY-C12, across the cell layers of living explants of human term placenta. Although all layers took up the fatty acid, rapid esterification of long-chain fatty acids and incorporation into lipid droplets was exclusive to the inner layer cytotrophoblast cells rather than the expected outer syncytiotrophoblast layer. Cytotrophoblast is a progenitor cell layer previously relegated to a repair role. As isolated cytotrophoblasts differentiated into syncytialized cells in culture, they weakened their lipid processing capacity. Syncytializing cells suppress previously active genes that regulate fatty-acid uptake (SLC27A2/FATP2, FABP4, ACSL5) and lipid metabolism (GPAT3, LPCAT3). We speculate that cytotrophoblast performs a previously unrecognized role in regulating placental fatty acid uptake and metabolism. PMID:27124483

  6. Ingestion of a single serving of saury alters postprandial levels of plasma n-3 polyunsaturated fatty acids and long-chain monounsaturated fatty acids in healthy human adults

    PubMed Central

    2012-01-01

    Background Saury oil contains considerable amounts of n-3 polyunsaturated fatty acids (PUFA) and monounsaturated fatty acids (MUFA) with long aliphatic tails (>18C atoms). Ingestion of saury oil reduces the risk of developing metabolic syndrome concomitant with increases in n-3 PUFA and long-chain MUFA in plasma and organs of mice. We therefore evaluated changes in postprandial plasma fatty acid levels and plasma parameters in healthy human subjects after ingestion of a single meal of saury. Findings Five healthy human adults ingested 150 g of grilled saury. Blood was collected before the meal and at 2, 6, and 24 hr after the meal, and plasma was prepared. Plasma levels of eicosapentaenoic acid, docosahexaenoic acid, and long-chain MUFA (C20:1 and C22:1 isomers combined) increased significantly throughout the postprandial period compared with the pre-meal baseline. Postprandial plasma insulin concentration increased notably, and plasma levels of glucose and free fatty acids decreased significantly and subsequently returned to the pre-meal levels. Conclusions Our study suggests that a single saury meal may alter the postprandial plasma levels of n-3 PUFA and long-chain MUFA in healthy human subjects. PMID:22846384

  7. Hydrocarbon binding by proteins: structures of protein binding sites for ≥C10 linear alkanes or long-chain alkyl and alkenyl groups.

    PubMed

    Park, Jiyong; Pham, Hung V; Mogensen, Kristian; Solling, Theis Ivan; Bennetzen, Martin Vad; Houk, K N

    2015-01-16

    In order to identify potential de novo enzyme templates for the cleavage of C–C single bonds in long-chain hydrocarbons, we analyzed protein structures that bind substrates containing alkyl and alkenyl functional groups. A survey of ligand-containing protein structures deposited in the Protein Data Bank resulted in 874 entries, consisting of 194 unique ligands that have ≥10 carbons in a linear chain. Fatty acids and phospholipids are the most abundant types of ligands. Hydrophobic amino acids forming α-helical structures frequently line the binding pockets. Occupation of these binding sites was evaluated by calculating both the buried surface area and volume employed by the ligands; these quantities are similar to those computed for drug–protein complexes. Surface complementarity is relatively low due to the nonspecific nature of the interaction between the long-chain hydrocarbons and the hydrophobic amino acids. The selected PDB structures were annotated on the basis of their SCOP and EC identification numbers, which will facilitate design template searches based on structural and functional homologies. Relatively low surface complementarity and ∼55% volume occupancy, also observed in synthetic-host, alkane-guest systems, suggest general principles for the recognition of long-chain linear hydrocarbons. PMID:25526284

  8. Oxidative stability of fish and algae oils containing long-chain polyunsaturated fatty acids in bulk and in oil-in-water emulsions.

    PubMed

    Frankel, Edwin N; Satué-Gracia, Teresa; Meyer, Anne S; German, J Bruce

    2002-03-27

    The oxidative stability of long-chain polyunsaturated fatty acid (PUFA) and docosahexaenoic acid (DHA)-containing fish and algae oils varies widely according to their fatty acid composition, the physical and colloidal states of the lipids, the contents of tocopherols and other antioxidants, and the presence and activity of transition metals. Fish and algal oils were initially much more stable to oxidation in bulk systems than in the corresponding oil-in-water emulsions. The oxidative stability of emulsions cannot, therefore, be predicted on the basis of stability data obtained with bulk long-chain PUFA-containing fish oils and DHA-containing algal oils. The relatively high oxidative stability of an algal oil containing 42% DHA was completely lost after chromatographic purification to remove tocopherols and other antioxidants. Therefore, this evidence does not support the claim that DHA-rich oils from algae are unusually stable to oxidation. Addition of ethylenediaminetetraacetic acid (EDTA) prevented oxidation of both fish and algal oil emulsions without added iron and at low iron:EDTA molar concentrations. EDTA, however, promoted the oxidation of the corresponding emulsions that contained high iron:EDTA ratios. Therefore, to be effective as a metal chelator, EDTA must be added at molar concentrations higher than that of iron to inhibit oxidation of foods containing long-chain PUFA from either fish or algae and fortified with iron. PMID:11902962

  9. Characterization of a long-chain fatty acid-CoA ligase 1 gene and association between its SNPs and growth traits in the clam Meretrix meretrix.

    PubMed

    Dai, Ping; Huan, Pin; Wang, Hongxia; Lu, Xia; Liu, Baozhong

    2015-07-25

    Long-chain fatty acid-CoA ligases (ACSLs) play crucial roles in fatty acid (FA) metabolism. They convert free long-chain FA into acyl-CoAs, which are key intermediates in both anabolic and catabolic pathways. A long-chain fatty acid-CoA ligase gene was cloned in the clam Meretrix meretrix (MmeACSL1), with a full-length cDNA of 1865 bp encoding 475 amino acids. Its expression was only detected in hepatopancreas by semi-quantitative reverse transcription PCR. Expression level of MmeACSL1 exhibited a significant increase in a starvation experiment (P<0.05). This indicates that MmeACSL1 plays an important role in normal metabolism of M. meretrix and may be involved in energy supply and storage. Two exon SNPs and six intron SNPs were developed in this gene by direct sequencing. A marker-trait association analysis showed that five of these SNPs were significantly associated with growth traits (P<0.05). Also, haplotypes comprised of the five SNPs were revealed to be significantly growth-related (P<0.05), which further corroborates the relationship of this gene to growth traits of M. meretrix. PMID:25900031

  10. Measurement of stable isotopic enrichment and concentration of long-chain fatty acyl-carnitines in tissue by HPLC-MS.

    PubMed

    Sun, Dayong; Cree, Melanie G; Zhang, Xiao-Jun; Bøersheim, Elisabet; Wolfe, Robert R

    2006-02-01

    We have developed a new method for the simultaneous measurements of stable isotopic tracer enrichments and concentrations of individual long-chain fatty acyl-carnitines in muscle tissue using ion-pairing high-performance liquid chromatography-electrospray ionization quadrupole mass spectrometry in the selected ion monitoring (SIM) mode. Long-chain fatty acyl-carnitines were extracted from frozen muscle tissue samples by acetonitrile/methanol. Baseline separation was achieved by reverse-phase HPLC in the presence of the volatile ion-pairing reagent heptafluorobutyric acid. The SIM capability of a single quadrupole mass analyzer allows further separation of the ions of interest from the sample matrixes, providing very clean total and selected ion chromatograms that can be used to calculate the stable isotopic tracer enrichment and concentration of long-chain fatty acyl-carnitines in a single analysis. The combination of these two separation techniques greatly simplifies the sample preparation procedure and increases the detection sensitivity. Applying this protocol to biological muscle samples proves it to be a very sensitive, accurate, and precise analytical tool. PMID:16301738

  11. Long-chain 3-hydroxyacyl-coenzyme A dehydrogenase deficiency with the G1528C mutation: clinical presentation of thirteen patients.

    PubMed

    Tyni, T; Palotie, A; Viinikka, L; Valanne, L; Salo, M K; von Döbeln, U; Jackson, S; Wanders, R; Venizelos, N; Pihko, H

    1997-01-01

    Long-chain 3-hydroxyacyl-coenzyme A (CoA) dehydrogenase is one of three enzyme activities of the mitochondrial trifunctional protein. We report the clinical findings of 13 patients with long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency. At presentation the patients had had hypoglycemia, cardiomyopathy, muscle hypotonia, and hepatomegaly during the first 2 years of life. Seven patients had recurrent metabolic crises, and six patients had a steadily progressive course. Two patients had cholestatic liver disease, which is uncommon in beta-oxidation defects. One patient had peripheral neuropathy, and six patients had retinopathy with focal pigmentary aggregations or retinal hypopigmentation. All patients were homozygous for the common mutation G1528C. However, the enoyl-CoA hydratase and 3-ketoacyl-CoA thiolase activities of the mitochondrial trifunctional protein were variably decreased in skin fibroblasts. Dicarboxylic aciduria was detected in 9 of 10 patients, and most patients had lactic acidosis, increased serum creatine kinase activities, and low serum carnitine concentration. Neuroradiologically there was bilateral periventricular or focal cortical lesions in three patients, and brain atrophy in one. Only one patient, who has had dietary treatment for 9 years, is alive at the age of 14 years; all others died before they were 2 years of age. Recognition of the clinical features of long-chain 3-hydroxyacyl-CoA deficiency is important for the early institution of dietary management, which may alter the otherwise invariably poor prognosis. PMID:9003853

  12. Anaerobic bag culture method.

    PubMed

    Rosenblatt, J E; Stewart, P R

    1975-06-01

    In a new method of anaerobic culture, a transparent, gas-impermeable bag is used and the anaerobic environment is established with copper sulfate-saturated steel wool. An Alka-Seltzer tablet generates carbon dioxide. The agar plate surface can be inspected through the bag at any time without interrupting the anaerobic atmosphere or disturbing other specimens. Methylene blue indicator strips are completely reduced by 4 h after the bag is set up and have remained reduced for as long as 3 weeks. Growth of 16 different stock culture anaerobes was generally equivalent by the bag and GasPak jar methods. Yield and growth of anaerobic isolates also were equivalent with 7 of 10 clinical specimens; from the other 3 specimens, 13 isolates were recovered, 5 by both the bag and jar methods and the rest by one method or the other. No consistent differences were found between the anaerobic bag and GasPak jar methods in the yield of anaerobes from clinical specimens. Early growth (24 h of incubation) of anaerobes from one specimen was detected with the bag method. PMID:1100671

  13. Anaerobic bag culture method.

    PubMed Central

    Rosenblatt, J E; Stewart, P R

    1975-01-01

    In a new method of anaerobic culture, a transparent, gas-impermeable bag is used and the anaerobic environment is established with copper sulfate-saturated steel wool. An Alka-Seltzer tablet generates carbon dioxide. The agar plate surface can be inspected through the bag at any time without interrupting the anaerobic atmosphere or disturbing other specimens. Methylene blue indicator strips are completely reduced by 4 h after the bag is set up and have remained reduced for as long as 3 weeks. Growth of 16 different stock culture anaerobes was generally equivalent by the bag and GasPak jar methods. Yield and growth of anaerobic isolates also were equivalent with 7 of 10 clinical specimens; from the other 3 specimens, 13 isolates were recovered, 5 by both the bag and jar methods and the rest by one method or the other. No consistent differences were found between the anaerobic bag and GasPak jar methods in the yield of anaerobes from clinical specimens. Early growth (24 h of incubation) of anaerobes from one specimen was detected with the bag method. Images PMID:1100671

  14. Anaerobic thermophilic culture

    DOEpatents

    Ljungdahl, Lars G.; Wiegel, Jurgen K. W.

    1981-01-01

    A newly discovered thermophilic anaerobe is described that was isolated in a biologically pure culture and designated Thermoanaerobacter ethanolicus ATCC 3/550. T. Ethanolicus is cultured in aqueous nutrient medium under anaerobic, thermophilic conditions and is used in a novel process for producing ethanol by subjecting carbohydrates, particularly the saccharides, to fermentation action of the new microorganism in a biologically pure culture.

  15. Full scale field demonstration of unheated anaerobic contact stabilization

    SciTech Connect

    Sykes, R.M.; Fan, K.S.

    1983-09-01

    A full scale field demonstration of unheated anaerobic digestion, including both solids recycle and solids nonrecycle processes, was conducted at the Jackson Pike Wastewater Treatment Plant at Columbus, Ohio. Two digesters (locally called Tanks 4E and 6E) at this facility were used for this purpose. In the experimental system, the operating temperature was reduced gradually from 91/sup 0/F to 63/sup 0/F. There were eight periods in the Recycle Phase and four periods in the Nonrecycle Phase. Gas production, solids destruction, volatile fatty acid variation, alkalinity, and pH were monitored in each period. In addition, grease, long-chain fatty acids, and foaming were intensively investigated at the last two periods, C and D, of the Nonrecycle Phase. The objectives of this research were: (1) evaluation of the unheated anaerobic digestion in full scale field units, and (2) and development of criteria for design and operation of a cold anaerobic digester. 48 references, 41 figures, 84 tables.

  16. Key players and team play: anaerobic microbial communities in hydrocarbon-contaminated aquifers.

    PubMed

    Kleinsteuber, Sabine; Schleinitz, Kathleen M; Vogt, Carsten

    2012-05-01

    Biodegradation of anthropogenic pollutants in shallow aquifers is an important microbial ecosystem service which is mainly brought about by indigenous anaerobic microorganisms. For the management of contaminated sites, risk assessment and control of natural attenuation, the assessment of in situ biodegradation and the underlying microbial processes is essential. The development of novel molecular methods, "omics" approaches, and high-throughput techniques has revealed new insight into complex microbial communities and their functions in anoxic environmental systems. This review summarizes recent advances in the application of molecular methods to study anaerobic microbial communities in contaminated terrestrial subsurface ecosystems. We focus on current approaches to analyze composition, dynamics, and functional diversity of subsurface communities, to link identity to activity and metabolic function, and to identify the ecophysiological role of not yet cultured microbes and syntrophic consortia. We discuss recent molecular surveys of contaminated sites from an ecological viewpoint regarding degrader ecotypes, abiotic factors shaping anaerobic communities, and biotic interactions underpinning the importance of microbial cooperation for microbial ecosystem services such as contaminant degradation. PMID:22476263

  17. Anaerobic specimen transport device.

    PubMed Central

    Wilkins, T D; Jimenez-Ulate, F

    1975-01-01

    A device is described and evaluated for the anaerobic transport of clinical specimens. The device limits the amount of oxygen entering with the sample to a maximum of 2%, which is rapidly removed by reacting with hydrogen in the presence of a palladium catalyst. The viability on swabs of 12 species of anaerobes, four strains of facultative anaerobes and a strain of Pseudomonas aeruginosa, was maintained during the length of the tests (24 or 48 h). The results demonstrated that this device protected even the more oxygen-sensitive clinical anaerobes from death due to oxygen exposure. This device can be used for swabs as well as for anaerobic collection and liquid and solid specimens. Images PMID:1104656

  18. Anaerobic degradation of linoleic oleic acids

    SciTech Connect

    Lalman, J.A.; Bagley, D.M.

    1999-07-01

    The anaerobic degradation of linoleic (C18:2) and oleic (C18:1) acids was examined in batch experiments. By-product distribution depended on both the type of long chain fatty acid added and initial substrate concentration. Major by-products were palmitic (C16), myristic (C14) and acetic acids. Trace quantities of palmitoleic (C16:1) and lauric (C12) acids were observed together with larger amounts of palmitic (C16), myristic (C14) and hexanoic (C6) acids in cultures incubated with 100 mg/L linoleic (C18:2) acid. Bio-hydrogenation of C18 fatty acids was not necessary for the {beta}-oxidation mechanism to proceed. Aceticlastic methanogenic inhibition was observed in cultures inoculated with greater than 50 mg/L linoleic (C18:2) acid. In cultures incubated with greater than 50 mg/L oleic (C18:1) acid, aceticlastic methanogenic inhibition was observed for a short time period.

  19. Organic intermediates in the anaerobic biodegradation of coal to methane under laboratory conditions

    USGS Publications Warehouse

    Orem, W.H.; Voytek, M.A.; Jones, E.J.; Lerch, H.E.; Bates, A.L.; Corum, M.D.; Warwick, P.D.; Clark, A.C.

    2010-01-01

    Organic intermediates in coal fluids produced by anaerobic biodegradation of geopolymers in coal play a key role in the production of methane in natural gas reservoirs. Laboratory biodegradation experiments on sub-bituminous coal from Texas, USA, were conducted using bioreactors to examine the organic intermediates relevant to methane production. Production of methane in the bioreactors was linked to acetate accumulation in bioreactor fluid. Long chain fatty acids, alkanes (C19-C36) and various low molecular weight aromatics, including phenols, also accumulated in the bioreactor fluid and appear to be the primary intermediates in the biodegradation pathway from coal-derived geopolymers to acetate and methane. ?? 2010.

  20. Stable carbon isotope discrimination in rice field soil during acetate turnover by syntrophic acetate oxidation or acetoclastic methanogenesis

    NASA Astrophysics Data System (ADS)

    Conrad, Ralf; Klose, Melanie

    2011-03-01

    Rice fields are an important source for the greenhouse gas methane. In Italian rice field soil CH 4 is produced either by hydrogenotrophic and acetoclastic methanogenesis, or by hydrogenotrophic methanogenesis and syntrophic acetate oxidation when temperatures are below and above about 40-45 °C, respectively. In order to see whether these acetate consumption pathways differently discriminate the stable carbon isotopes of acetate, we measured the δ 13C of total acetate and acetate-methyl as well as the δ 13C of CO 2 and CH 4 in rice field soil that had been pre-incubated at 45 °C and then shifted to different temperatures between 25 and 50 °C. Acetate transiently accumulated to about 6 mM, which is about one-third of the amount of CH 4 produced, irrespective of the incubation temperature and the CH 4 production pathway involved. However, the patterns of δ 13C of the CH 4 and CO 2 produced were different at low (25, 30, 35 °C) versus high (40, 45, 50 °C) temperatures. These patterns were consistent with CH 4 being exclusively formed by hydrogenotrophic methanogenesis at high temperatures, and by a combination of acetoclastic and hydrogenotrophic methanogenesis at low temperatures. The patterns of δ 13C of total acetate and acetate-methyl were also different at high versus low temperatures, indicating the involvement of different pathways of production and consumption of acetate at the two temperature regimes. Isotope fractionation during consumption of the methyl group of acetate was more pronounced at low ( α = 1.010-1.025) than at high ( α = 1.0-1.01) temperatures indicating that acetoclastic methanogenesis exhibits a stronger isotope effect than syntrophic acetate oxidation. Small amounts of propionate also transiently accumulated and were analyzed for δ 13C. The δ 13C values slightly increased (by about 10‰) during production and consumption of propionate, but were not affected by incubation temperature. Collectively, our results showed distinct

  1. Anaerobic Digestion and its Applications

    EPA Science Inventory

    Anaerobic digestion is a natural biological process. The initials "AD" may refer to the process of anaerobic digestion, or the built systems of anaerobic digesters. While there are many kinds of digesters, the biology is basically the same for all. Anaerobic digesters are built...

  2. The Role of Benzoate in Anaerobic Degradation of Terephthalate

    PubMed Central

    Kleerebezem, Robbert; Pol, Look W. Hulshoff; Lettinga, Gatze

    1999-01-01

    The effects of acetate, benzoate, and periods without substrate on the anaerobic degradation of terephthalate (1,4-benzene-dicarboxylate) by a syntrophic methanogenic culture were studied. The culture had been enriched on terephthalate and was capable of benzoate degradation without a lag phase. When incubated with a mixture of benzoate and terephthalate, subsequent degradation with preference for benzoate was observed. Both benzoate and acetate inhibited the anaerobic degradation of terephthalate. The observed inhibition is partially irreversible, resulting in a decrease (or even a complete loss) of the terephthalate-degrading activity after complete degradation of benzoate or acetate. Irreversible inhibition was characteristic for terephthalate degradation only because the inhibition of benzoate degradation by acetate could well be described by reversible noncompetitive product inhibition. Terephthalate degradation was furthermore irreversibly inhibited by periods without substrate of only a few hours. The inhibition of terephthalate degradation due to periods without substrate could be overcome through incubation of the culture with a mixture of benzoate and terephthalate. In this case no influence of a period without substrate was observed. Based on these observations it is postulated that decarboxylation of terephthalate, resulting in the formation of benzoate, is strictly dependent on the concomitant fermentation of benzoate. In the presence of higher concentrations of benzoate, however, benzoate is the favored substrate over terephthalate, and the culture loses its ability to degrade terephthalate. In order to overcome the inhibition of terephthalate degradation by benzoate and acetate, a two-stage reactor system is suggested for the treatment of wastewater generated during terephthalic acid production. PMID:10049877

  3. The effects of elevated CO2 concentration on competitive interaction between aceticlastic and syntrophic methanogenesis in a model microbial consortium

    PubMed Central

    Kato, Souichiro; Yoshida, Rina; Yamaguchi, Takashi; Sato, Tomoyuki; Yumoto, Isao; Kamagata, Yoichi

    2014-01-01

    Investigation of microbial interspecies interactions is essential for elucidating the function and stability of microbial ecosystems. However, community-based analyses including molecular-fingerprinting methods have limitations for precise understanding of interspecies interactions. Construction of model microbial consortia consisting of defined mixed cultures of isolated microorganisms is an excellent method for research on interspecies interactions. In this study, a model microbial consortium consisting of microorganisms that convert acetate into methane directly (Methanosaeta thermophila) and syntrophically (Thermacetogenium phaeum and Methanothermobacter thermautotrophicus) was constructed and the effects of elevated CO2 concentrations on intermicrobial competition were investigated. Analyses on the community dynamics by quantitative RT-PCR and fluorescent in situ hybridization targeting their 16S rRNAs revealed that high concentrations of CO2 have suppressive effects on the syntrophic microorganisms, but not on the aceticlastic methanogen. The pathways were further characterized by determining the Gibbs free energy changes (ΔG) of the metabolic reactions conducted by each microorganism under different CO2 concentrations. The ΔG value of the acetate oxidation reaction (T. phaeum) under high CO2 conditions became significantly higher than -20 kJ per mol of acetate, which is the borderline level for sustaining microbial growth. These results suggest that high concentrations of CO2 undermine energy acquisition of T. phaeum, resulting in dominance of the aceticlastic methanogen. This study demonstrates that investigation on model microbial consortia is useful for untangling microbial interspecies interactions, including competition among microorganisms occupying the same trophic niche in complex microbial ecosystems. PMID:25400628

  4. Efficient metabolic exchange and electron transfer within a syntrophic trichloroethene-degrading coculture of Dehalococcoides mccartyi 195 and Syntrophomonas wolfei.

    PubMed

    Mao, Xinwei; Stenuit, Benoit; Polasko, Alexandra; Alvarez-Cohen, Lisa

    2015-03-01

    Dehalococcoides mccartyi 195 (strain 195) and Syntrophomonas wolfei were grown in a sustainable syntrophic coculture using butyrate as an electron donor and carbon source and trichloroethene (TCE) as an electron acceptor. The maximum dechlorination rate (9.9 ± 0.1 μmol day(-1)) and cell yield [(1.1 ± 0.3) × 10(8) cells μmol(-1) Cl(-)] of strain 195 maintained in coculture were, respectively, 2.6 and 1.6 times higher than those measured in the pure culture. The strain 195 cell concentration was about 16 times higher than that of S. wolfei in the coculture. Aqueous H2 concentrations ranged from 24 to 180 nM during dechlorination and increased to 350 ± 20 nM when TCE was depleted, resulting in cessation of butyrate fermentation by S. wolfei with a theoretical Gibbs free energy of -13.7 ± 0.2 kJ mol(-1). Carbon monoxide in the coculture was around 0.06 μmol per bottle, which was lower than that observed for strain 195 in isolation. The minimum H2 threshold value for TCE dechlorination by strain 195 in the coculture was 0.6 ± 0.1 nM. Cell aggregates during syntrophic growth were observed by scanning electron microscopy. The interspecies distances to achieve H2 fluxes required to support the measured dechlorination rates were predicted using Fick's law and demonstrated the need for aggregation. Filamentous appendages and extracellular polymeric substance (EPS)-like structures were present in the intercellular spaces. The transcriptome of strain 195 during exponential growth in the coculture indicated increased ATP-binding cassette transporter activities compared to the pure culture, while the membrane-bound energy metabolism related genes were expressed at stable levels. PMID:25576615

  5. Efficient Metabolic Exchange and Electron Transfer within a Syntrophic Trichloroethene-Degrading Coculture of Dehalococcoides mccartyi 195 and Syntrophomonas wolfei

    PubMed Central

    Mao, Xinwei; Stenuit, Benoit; Polasko, Alexandra

    2015-01-01

    Dehalococcoides mccartyi 195 (strain 195) and Syntrophomonas wolfei were grown in a sustainable syntrophic coculture using butyrate as an electron donor and carbon source and trichloroethene (TCE) as an electron acceptor. The maximum dechlorination rate (9.9 ± 0.1 μmol day−1) and cell yield [(1.1 ± 0.3) × 108 cells μmol−1 Cl−] of strain 195 maintained in coculture were, respectively, 2.6 and 1.6 times higher than those measured in the pure culture. The strain 195 cell concentration was about 16 times higher than that of S. wolfei in the coculture. Aqueous H2 concentrations ranged from 24 to 180 nM during dechlorination and increased to 350 ± 20 nM when TCE was depleted, resulting in cessation of butyrate fermentation by S. wolfei with a theoretical Gibbs free energy of −13.7 ± 0.2 kJ mol−1. Carbon monoxide in the coculture was around 0.06 μmol per bottle, which was lower than that observed for strain 195 in isolation. The minimum H2 threshold value for TCE dechlorination by strain 195 in the coculture was 0.6 ± 0.1 nM. Cell aggregates during syntrophic growth were observed by scanning electron microscopy. The interspecies distances to achieve H2 fluxes required to support the measured dechlorination rates were predicted using Fick's law and demonstrated the need for aggregation. Filamentous appendages and extracellular polymeric substance (EPS)-like structures were present in the intercellular spaces. The transcriptome of strain 195 during exponential growth in the coculture indicated increased ATP-binding cassette transporter activities compared to the pure culture, while the membrane-bound energy metabolism related genes were expressed at stable levels. PMID:25576615

  6. Membrane controlled anaerobic digestion

    NASA Astrophysics Data System (ADS)

    Omstead, D. R.

    In response to general shortages of energy, examination of the anaerboic digestion process as a potential source of a combustible, methane-rich fuel has intensified in recent years. It has been suggested that orgaic intermediates (such as fatty acids), produced during digestion, might also be recovered for use as chemical feedstocks. This investigation has been concerned with combining ultrafiltration separation techniques with anaerobic digestion for the development of a process in which the total production of acetic acid (the most valuable intermediate in anaerobic digestion) and methane are optimized. Enrichment cultures, able to utilize glucose as a sole carbon source, were adapted from sewage digesting cultures using conventional techniques. An ultrafiltration system was constructed and coupled to an anaerobic digester culture vessel which contained the glucose enrichment. The membrane controlled anaerobic digester appears to show promise as a means of producing high rates of both methane gas and acetic acid.

  7. Anaerobic brain abscess

    PubMed Central

    Sudhaharan, Sukanya; Chavali, Padmasri

    2016-01-01

    Background and Objectives: Brain abscess remains a potentially fatal central nervous system (CNS) disease, especially in developing countries. Anaerobic abscess is difficult to diagnose because of cumbersome procedures associated with the isolation of anaerobes. Materials and Methods: This is a hospital-based retrospective microbiological analysis of 430 brain abscess materials (purulent aspirates and/or tissue), for anaerobic organisms, that were received between 1987–2014, by the Microbiology Laboratory in our Institute. Results: Culture showed growth of bacteria 116/430 (27%) of the cases of which anaerobes were isolated in 48/116 (41.1%) of the cases. Peptostreptococcus (51.4 %), was the predominant organism isolated in four cases followed by Bacteroides and Peptococcus species. Conclusion: Early diagnosis and detection of these organisms would help in the appropriate management of these patients. PMID:27307977

  8. Increased Long Chain acyl-Coa Synthetase Activity and Fatty Acid Import Is Linked to Membrane Synthesis for Development of Picornavirus Replication Organelles

    PubMed Central

    Scott, Alison J.; Ford, Lauren A.; Pei, Zhengtong; Watkins, Paul A.; Ernst, Robert K.; Belov, George A.

    2013-01-01

    All positive strand (+RNA) viruses of eukaryotes replicate their genomes in association with membranes. The mechanisms of membrane remodeling in infected cells represent attractive targets for designing future therapeutics, but our understanding of this process is very limited. Elements of autophagy and/or the secretory pathway were proposed to be hijacked for building of picornavirus replication organelles. However, even closely related viruses differ significantly in their requirements for components of these pathways. We demonstrate here that infection with diverse picornaviruses rapidly activates import of long chain fatty acids. While in non-infected cells the imported fatty acids are channeled to lipid droplets, in infected cells the synthesis of neutral lipids is shut down and the fatty acids are utilized in highly up-regulated phosphatidylcholine synthesis. Thus the replication organelles are likely built from de novo synthesized membrane material, rather than from the remodeled pre-existing membranes. We show that activation of fatty acid import is linked to the up-regulation of cellular long chain acyl-CoA synthetase activity and identify the long chain acyl-CoA syntheatse3 (Acsl3) as a novel host factor required for polio replication. Poliovirus protein 2A is required to trigger the activation of import of fatty acids independent of its protease activity. Shift in fatty acid import preferences by infected cells results in synthesis of phosphatidylcholines different from those in uninfected cells, arguing that the viral replication organelles possess unique properties compared to the pre-existing membranes. Our data show how poliovirus can change the overall cellular membrane homeostasis by targeting one critical process. They explain earlier observations of increased phospholipid synthesis in infected cells and suggest a simple model of the structural development of the membranous scaffold of replication complexes of picorna-like viruses, that may be

  9. An alternate pathway to long-chain polyunsaturates: the FADS2 gene product Δ8-desaturates 20:2n-6 and 20:3n-3

    PubMed Central

    Park, Woo Jung; Kothapalli, Kumar S. D.; Lawrence, Peter; Tyburczy, Cynthia; Brenna, J. Thomas

    2009-01-01

    The mammalian Δ6-desaturase coded by fatty acid desaturase 2 (FADS2; HSA11q12-q13.1) catalyzes the first and rate-limiting step for the biosynthesis of long-chain polyunsaturated fatty acids. FADS2 is known to act on at least five substrates, and we hypothesized that the FADS2 gene product would have Δ8-desaturase activity. Saccharomyces cerevisiae transformed with a FADS2 construct from baboon neonate liver cDNA gained the function to desaturate 11,14-eicosadienoic acid (20:2n-6) and 11,14,17-eicosatrienoic acid (20:3n-3) to yield 20:3n-6 and 20:4n-3, respectively. Competition experiments indicate that Δ8-desaturation favors activity toward 20:3n-3 over 20:2n-6 by 3-fold. Similar experiments show that Δ6-desaturase activity is favored over Δ8-desaturase activity by 7-fold and 23-fold for n-6 (18:2n-6 vs 20:2n-6) and n-3 (18:3n-3 vs 20:3n-3), respectively. In mammals, 20:3n-6 is the immediate precursor of prostaglandin E1 and thromboxane B1. 20:3n-6 and 20:4n-3 are also immediate precursors of long-chain polyunsaturated fatty acids arachidonic acid and eicosapentaenoic acid, respectively. These findings provide unequivocal molecular evidence for a novel alternative biosynthetic route to long-chain polyunsaturated fatty acids in mammals from substrates previously considered to be dead-end products. PMID:19202133

  10. Long-chain omega-3 fatty acids, fibrates and niacin as therapeutic options in the treatment of hypertriglyceridemia: a review of the literature.

    PubMed

    Ito, Matthew K

    2015-10-01

    Hypertriglyceridemia affects approximately 33% of the US population. Elevated triglyceride levels are independently associated with cardiovascular disease (CVD) risk, and severe hypertriglyceridemia is a risk factor for acute pancreatitis. Guidelines for the management of severe hypertriglyceridemia (≥5.6 mmol/L [≥500 mg/dL]) recommend immediate use of triglyceride-lowering agents; however, statins remain the first line of therapy for the management of mild to moderate hypertriglyceridemia (1.7-5.6 mmol/L [150-499 mg/dL]). Statins primarily target elevated low-density lipoprotein cholesterol levels, but have also been shown to reduce mean triglyceride levels by up to 18% (or 43% in patients with triglyceride levels≥3.1 mmol/L [≥273 mg/dL]). However, individuals with hypertriglyceridemia may need additional reduction in triglyceride-rich lipoproteins and remnant particles to further reduce residual CVD risk. A number of guidelines recommend the addition of fibrates, niacin, or long-chain omega-3 fatty acids if elevated triglyceride or non-high-density lipoprotein cholesterol levels persist despite the use of high-intensity statin therapy. This review evaluates the impact of fibrates, niacin, and long-chain omega-3 fatty acids on lipid profiles and cardiovascular outcomes in patients with hypertriglyceridemia. It also assesses the adverse effects and drug-drug interactions associated with these triglyceride-lowering agents, because although they have all been shown to effectively reduce triglyceride levels in patients with hypertriglyceridemia, they differ with regard to their associated benefit-risk profiles. Long-chain omega-3 fatty acids may be a well-tolerated and effective alternative to fibrates and niacin, yet further large-scale clinical studies are required to evaluate their effects on cardiovascular outcomes and CVD risk reduction in patients with hypertriglyceridemia. PMID:26296750

  11. Effects of short-term and long-term treatment with medium- and long-chain triglycerides ketogenic diet on cortical spreading depression in young rats.

    PubMed

    de Almeida Rabello Oliveira, Marcela; da Rocha Ataíde, Terezinha; de Oliveira, Suzana Lima; de Melo Lucena, Ana Luíza; de Lira, Carla Emmanuela Pereira Rodrigues; Soares, Anderson Acioli; de Almeida, Clarissa Beatriz Santos; Ximenes-da-Silva, Adriana

    2008-03-21

    The ketogenic diet (KD) is a high fat and low carbohydrate and protein diet. It is used in the clinical treatment of epilepsy, in order to decrease cerebral excitability. KD is usually composed by long-chain triglycerides (LCT) while medium-chain triglycerides (MCT) diet is beginning to be used in some clinical treatment of disorders of pyruvate carboxylase enzyme and long-chain fatty acid oxidation. Our study aimed to analyze the effects of medium- and long-chain KD on cerebral electrical activity, analyzing the propagation of the phenomenon of cortical spreading depression (CSD). Three groups of weaned rats (21 days old) received, for 7 weeks, either a control (AIN-93G diet), or a MCT-KD (rich in triheptanoin oil), or a LCT-KD (rich in soybean oil). They were compared to another three groups (21 days old) receiving the same diets for just 10 days. CSD propagation was evaluated just after ending the dietary treatments. Results showed that short-term KD treatment resulted in a significant reduction of the CSD velocity of propagation (control group: 4.02+/-1.04mm/min; MCT-KD: 0.81+/-1.46mm/min and LCT-KD: 2.26+/-0.41mm/min) compared to the control group. However, long-term treatment with both KDs had no effect on the CSD velocity (control group: 3.10+/-0.41mm/min, MCT-KD: 2.91+/-1.62mm/min, LCT-KD: 3.02+/-2.26mm/min) suggesting that both short-term KDs have a positive effect in decreasing brain cerebral excitability in young animals. These data show for the first time that triheptanoin has an effect on central nervous system. PMID:18281154

  12. Evaluating the potential impact of proton carriers on syntrophic propionate oxidation

    NASA Astrophysics Data System (ADS)

    Juste-Poinapen, Natacha M. S.; Turner, Mark S.; Rabaey, Korneel; Virdis, Bernardino; Batstone, Damien J.

    2015-12-01

    Anaerobic propionic acid degradation relies on interspecies electron transfer (IET) between propionate oxidisers and electron acceptor microorganisms, via either molecular hydrogen, formate or direct transfers. We evaluated the possibility of stimulating direct IET, hence enhancing propionate oxidation, by increasing availability of proton carriers to decrease solution resistance and reduce pH gradients. Phosphate was used as a proton carrying anion, and chloride as control ion together with potassium as counter ion. Propionic acid consumption in anaerobic granules was assessed in a square factorial design with ratios (1:0, 2:1, 1:1, 1:2 and 0:1) of total phosphate (TP) to Cl-, at 1X, 10X, and 30X native conductivity (1.5 mS.cm-1). Maximum specific uptake rate, half saturation, and time delay were estimated using model-based analysis. Community profiles were analysed by fluorescent in situ hybridisation and 16S rRNA gene pyrosequencing. The strongest performance was at balanced (1:1) ratios at 10X conductivity where presumptive propionate oxidisers namely Syntrophobacter and Candidatus Cloacamonas were more abundant. There was a shift from Methanobacteriales at high phosphate, to Methanosaeta at low TP:Cl ratios and low conductivity. A lack of response to TP, and low percentage of presumptive electroactive organisms suggested that DIET was not favoured under the current experimental conditions.

  13. Evaluating the potential impact of proton carriers on syntrophic propionate oxidation

    PubMed Central

    Juste-Poinapen, Natacha M. S.; Turner, Mark S.; Rabaey, Korneel; Virdis, Bernardino; Batstone, Damien J.

    2015-01-01

    Anaerobic propionic acid degradation relies on interspecies electron transfer (IET) between propionate oxidisers and electron acceptor microorganisms, via either molecular hydrogen, formate or direct transfers. We evaluated the possibility of stimulating direct IET, hence enhancing propionate oxidation, by increasing availability of proton carriers to decrease solution resistance and reduce pH gradients. Phosphate was used as a proton carrying anion, and chloride as control ion together with potassium as counter ion. Propionic acid consumption in anaerobic granules was assessed in a square factorial design with ratios (1:0, 2:1, 1:1, 1:2 and 0:1) of total phosphate (TP) to Cl−, at 1X, 10X, and 30X native conductivity (1.5 mS.cm−1). Maximum specific uptake rate, half saturation, and time delay were estimated using model-based analysis. Community profiles were analysed by fluorescent in situ hybridisation and 16S rRNA gene pyrosequencing. The strongest performance was at balanced (1:1) ratios at 10X conductivity where presumptive propionate oxidisers namely Syntrophobacter and Candidatus Cloacamonas were more abundant. There was a shift from Methanobacteriales at high phosphate, to Methanosaeta at low TP:Cl ratios and low conductivity. A lack of response to TP, and low percentage of presumptive electroactive organisms suggested that DIET was not favoured under the current experimental conditions. PMID:26670292

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

    PubMed Central

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

    2015-01-01

    The global consumption of fish oils currently exceeds one million tonnes, with the natural de novo source of these important fatty acids forming the base of marine foodwebs. Here we describe the first field-based evaluation of a terrestrial source of these essential nutrients, synthesised in the seeds of transgenic Camelina sativa plants via the heterologous reconstitution of the omega-3 long chain polyunsaturated fatty acid biosynthetic pathway. Our data demonstrate the robust nature of this novel trait, and the feasibility of making fish oils in genetically modified crops. Moreover, to our knowledge, this is the most complex example of plant genetic engineering to undergo environmental release and field evaluation. PMID:27066395

  15. Isolation of cytotoxic glucoerebrosides and long-chain bases from sea cucumber Cucumaria frondosa using high speed counter-current chromatography.

    PubMed

    Xu, Jie; Guo, Shuang; Du, Lei; Wang, Yu-Ming; Sugawara, Tatsuya; Hirata, Takashi; Xue, Chang-Hu

    2013-01-01

    Total glucocerebrosides of the sea cucumber Cucumaria frondosa (CFC) have been isolated from the less polar lipid fraction of the chloroform-methanol extract using high speed counter-current chromatography (HSCCC) with a two-phase solvent system composed of petroleum ether-methanol-water (5:4:1, v/v). Three glucocerebroside molecular species (CFC-1, CFC-2 and CFC-3) were isolated from crude total cerebrosides with repeated column chromatography. The structures of these three glucocerebroside molecular species were determined on the basis of chemical and spectroscopic evidence: fatty acids were mainly saturated (C22:0 and C18:0), monounsaturated (C24:1 and C20:1) and α-hydroxyl fatty acids (C24:1h, C23:0h, C23:1h and C22:0h), the structures of long-chain bases were dihydroxy (d17:1, d18:2 and d18:1) and trihydroxy (t17:0 and t16:0), and the glycosylation was glucose. High purity long-chain bases of sea cucumber Cucumaria frondosa (CF-LCB) were prepared from total lipids by HSCCC with a two-phase solvent system composed of n-hexane-methyl tert butyl ether-methanol-water (1:1:2:1, v/v). Compare with traditional preparative methods, the method of HSCCC is short cycle, high yield and less solvent consumption. The composition analysis of CF-LCB showed that the ratio of d18:2 and d17:1 was approximately 2:1. The four glucocerebrosides and long-chain bases from sea cucumber Cucumaria frondosa were evaluated for activity in vitro assays for the cytotoxic activities against Caco-2 colon cancer cells. The results indicated that both glucocerebrosides and long-chain bases exhibited an inhibitory effect on cell proliferation. Moreover, CFC-3 was most effective in four glucocerebrosides to Caco-2 cell viability. The inhibition effect of CF-LCB was much stronger than glucocerebrosides. PMID:23470440

  16. Anaerobic Codigestion of Sludge: Addition of Butcher's Fat Waste as a Cosubstrate for Increasing Biogas Production.

    PubMed

    Martínez, E J; Gil, M V; Fernandez, C; Rosas, J G; Gómez, X

    2016-01-01

    Fat waste discarded from butcheries was used as a cosubstrate in the anaerobic codigestion of sewage sludge (SS). The process was evaluated under mesophilic and thermophilic conditions. The codigestion was successfully attained despite some inhibitory stages initially present that had their origin in the accumulation of volatile fatty acids (VFA) and adsorption of long-chain fatty acids (LCFA). The addition of a fat waste improved digestion stability and increased biogas yields thanks to the higher organic loading rate (OLR) applied to the reactors. However, thermophilic digestion was characterized by an effluent of poor quality and high VFA content. Results from spectroscopic analysis suggested the adsorption of lipid components onto the anaerobic biomass, thus disturbing the complete degradation of substrate during the treatment. The formation of fatty aggregates in the thermophilic reactor prevented process failure by avoiding the exposure of biomass to the toxic effect of high LCFA concentrations. PMID:27071074

  17. Adaption of microbial community during the start-up stage of a thermophilic anaerobic digester treating food waste.

    PubMed

    Wu, Bo; Wang, Xing; Deng, Ya-Yue; He, Xiao-Lan; Li, Zheng-Wei; Li, Qiang; Qin, Han; Chen, Jing-Tao; He, Ming-Xiong; Zhang, Min; Hu, Guo-Quan; Yin, Xiao-Bo

    2016-10-01

    A successful start-up enables acceleration of anaerobic digestion (AD) into steady state. The microbial community influences the AD performance during the start-up. To investigate how microbial communities changed during the start-up, microbial dynamics was analyzed via high-throughput sequencing in this study. The results confirmed that the AD was started up within 25 d. Thermophilic methanogens and bacterial members functioning in hydrolysis, acidogenesis, and syntrophic oxidation became predominant during the start-up stage, reflecting a quick adaption of microorganisms to operating conditions. Such predominance also indicated the great contribution of these members to the fast start-up of AD. Redundancy analysis confirmed that the bacterial abundance significantly correlated with AD conditions. The stable ratio of hydrogenotrophic methanogens to aceticlastic methanogens is also important to maintain the stability of the AD process. This work will be helpful to understand the contribution of microbial community to the start-up of AD. PMID:27251412

  18. Evaluation and characterization during the anaerobic digestion of high-strength kitchen waste slurry via a pilot-scale anaerobic membrane bioreactor.

    PubMed

    Xiao, Xiaolan; Huang, Zhenxing; Ruan, Wenquan; Yan, Lintao; Miao, Hengfeng; Ren, Hongyan; Zhao, Mingxing

    2015-10-01

    The anaerobic digestion of high-strength kitchen waste slurry via a pilot-scale anaerobic membrane bioreactor (AnMBR) was investigated at two different operational modes, including no sludge discharge and daily sludge discharge of 20 L. The AnMBR provided excellent and reliable permeate quality with high COD removal efficiencies over 99%. The obvious accumulations of long chain fatty acids (LCFAs) and Ca(2+) were found in the anaerobic digester by precipitation and agglomeration. Though the physicochemical process contributed to attenuating the free LCFAs toxicity on anaerobic digestion, the digestion efficiency was partly influenced for the low bioavailability of those precipitates. Moreover, higher organic loading rate (OLR) of 5.8 kg COD/(m(3) d) and digestion efficiency of 78% were achieved as the AnMBR was stably operated with sludge discharge, where the membrane fouling propensity was also alleviated, indicating the crucial significance of SRT control on the treatment of high-strength kitchen waste slurry via AnMBRs. PMID:26141283

  19. Methanogenesis facilitated by geobiochemical iron cycle in a novel syntrophic methanogenic microbial community.

    PubMed

    Jiang, Shenghua; Park, Sunhwa; Yoon, Younggun; Lee, Ji-Hoon; Wu, Wei-Min; Phuoc Dan, Nguyen; Sadowsky, Michael J; Hur, Hor-Gil

    2013-09-01

    Production and emission of methane have been increasing concerns due to its significant effect on global climate change and the carbon cycle. Here we report facilitated methane production from acetate by a novel community of methanogens and acetate oxidizing bacteria in the presence of poorly crystalline akaganeite slurry. Comparative analyses showed that methanogenesis was significantly enhanced by added akaganeite and acetate was mostly stoichiometrically converted to methane. Electrons produced from anaerobic acetate oxidation are transferred to akaganeite nanorods that likely prompt the transformation into goethite nanofibers through a series of biogeochemical processes of soluble Fe(II) readsorption and Fe(III) reprecipitation. The methanogenic archaea likely harness the biotransformation of akaganeite to goethite by the Fe(III)-Fe(II) cycle to facilitate production of methane. These results provide new insights into biogeochemistry of iron minerals and methanogenesis in the environment, as well as the development of sustainable methods for microbial methane production. PMID:23919295

  20. Genetic adaptation of fatty-acid metabolism: a human-specific haplotype increasing the biosynthesis of long-chain omega-3 and omega-6 fatty acids.

    PubMed

    Ameur, Adam; Enroth, Stefan; Johansson, Asa; Zaboli, Ghazal; Igl, Wilmar; Johansson, Anna C V; Rivas, Manuel A; Daly, Mark J; Schmitz, Gerd; Hicks, Andrew A; Meitinger, Thomas; Feuk, Lars; van Duijn, Cornelia; Oostra, Ben; Pramstaller, Peter P; Rudan, Igor; Wright, Alan F; Wilson, James F; Campbell, Harry; Gyllensten, Ulf

    2012-05-01

    Omega-3 and omega-6 long-chain polyunsaturated fatty acids (LC-PUFAs) are essential for the development and function of the human brain. They can be obtained directly from food, e.g., fish, or synthesized from precursor molecules found in vegetable oils. To determine the importance of genetic variability to fatty-acid biosynthesis, we studied FADS1 and FADS2, which encode rate-limiting enzymes for fatty-acid conversion. We performed genome-wide genotyping (n = 5,652 individuals) and targeted resequencing (n = 960 individuals) of the FADS region in five European population cohorts. We also analyzed available genomic data from human populations, archaic hominins, and more distant primates. Our results show that present-day humans have two common FADS haplotypes-defined by 28 closely linked SNPs across 38.9 kb-that differ dramatically in their ability to generate LC-PUFAs. No independent effects on FADS activity were seen for rare SNPs detected by targeted resequencing. The more efficient, evolutionarily derived haplotype appeared after the lineage split leading to modern humans and Neanderthals and shows evidence of positive selection. This human-specific haplotype increases the efficiency of synthesizing essential long-chain fatty acids from precursors and thereby might have provided an advantage in environments with limited access to dietary LC-PUFAs. In the modern world, this haplotype has been associated with lifestyle-related diseases, such as coronary artery disease. PMID:22503634

  1. Medium-chain versus long-chain triacylglycerol emulsion hydrolysis by lipoprotein lipase and hepatic lipase: Implications for the mechanisms of lipase action

    SciTech Connect

    Deckelbaum, R.J. ); Hamilton, J.A.; Butbul, E.; Gutman, A. ); Moser, A. ); Bengtsson-Olivecrona, G.; Olivecrona, T. ); Carpentier, Y.A. )

    1990-02-06

    To explore how enzyme affinities and enzyme activities regulate hydrolysis of water-insoluble substrates, the authors compared hydrolysis of phospholipid-stabilized emulsions of medium-chain (MCT) versus long-chain triacylglycerols (LCT). Because substrate solubility at the emulsion surface might modulate rates of hydrolysis, the ability of egg yolk phosphatidylcholine to solubilize MCT was examined by NMR spectroscopy. Chemical shift measurements showed that 11 mol % of ({sup 13}C)carbonyl enriched trioctanoin was incorporated into phospholipid vesicles as a surface component. Line widths of trioctanoin surface peaks were half that of LCT, and relaxation times, T{sub 1}, were also shorter for trioctanoin, showing greater mobility for MCT in phospholipid. In assessing the effects of these differences in solubility on lipolysis, they found that both purified bovine milk lipoprotein lipase and human hepatic lipase hydrolyzed MCT at rates at least 2-fold higher than for LCT. Differences in affinity were also demonstrated in mixed incubations where increasing amounts of LCT emulsion resulted in decreased hydrolysis of MCT emulsions. These results suggest that despite lower enzyme affinity for MCT emulsions, shorter chain triacylglycerols are more readily hydrolyzed by lipoprotein and hepatic lipases than long-chain triacylglycerols because of greater MCT solubility and mobility at the emulsion-water interface.

  2. One-step production of long-chain hydrocarbons from waste-biomass-derived chemicals using bi-functional heterogeneous catalysts.

    PubMed

    Wen, Cun; Barrow, Elizabeth; Hattrick-Simpers, Jason; Lauterbach, Jochen

    2014-02-21

    In this study, we demonstrate the production of long-chain hydrocarbons (C8+) from 2-methylfuran (2MF) and butanal in a single step reactive process by utilizing a bi-functional catalyst with both acid and metallic sites. Our approach utilizes a solid acid for the hydroalkylation function and as a support as well as a transition metal as hydrodeoxygenation catalyst. A series of solid acids was screened, among which MCM-41 demonstrated the best combination of activity and stability. Platinum nanoparticles were then incorporated into the MCM-41. The Pt/MCM-41 catalyst showed 96% yield for C8+ hydrocarbons and the catalytic performance was stable over four reaction cycles of 20 hour each. The reaction pathways for the production of long-chain hydrocarbons is probed with a combination of infrared spectroscopy and steady-state reaction experiments. It is proposed that 2MF and butanal go through hydroalkylation first on the acid site followed by hydrodeoxygenation to produce the hydrocarbon fuels. PMID:24394495

  3. Effect of triacylglycerols containing medium- and long-chain fatty acids on serum triacylglycerol levels and body fat in college athletes.

    PubMed

    Takeuchi, Hiroyuki; Kasai, Michio; Taguchi, Nobuo; Tsuji, Hiroaki; Suzuki, Masashige

    2002-04-01

    Triacylglycerols containing medium- and long-chain fatty acids (TML) have medium- and long-chain fatty acids in the same molecule. The effects of dietary TML on serum lipid levels and body fat were studied in six young men belonging to a university rowing club. A double-blind crossover study was performed in which for 3 wk the subjects ingested a liquid diet containing 20 g/d of soybean oil or TML in addition to their regular diets. Throughout the study, they were asked to keep their usual lifestyle, including diet and physical activity. The body composition of the subjects was measured weekly. Blood samples were taken at 0, 2, and 3 wk of each treatment period. There was no significant difference in energy intake between the soybean oil diet period and the TML diet period. The rate of variation of serum triacylglycerol concentration was significantly lower after a consumption of the TML liquid diet for 3 wk compared with the soybean oil liquid diet. The rate of variation of body fat mass was also significantly lower after a consumption of the TML liquid diet for 3 wk compared with the soybean oil liquid diet. However, the serum cholesterol concentration did not change significantly during either dietary treatment. These results suggest that TML, compared with soybean oil, may have the potential to prevent hypertriglyceridemia and obesity caused by consumption of a high-fat diet. PMID:12171430

  4. Different effects of short- and long-chained fructans on large intestinal physiology and carcinogen-induced aberrant crypt foci in rats.

    PubMed

    Poulsen, Morten; Mølck, Anne-Marie; Jacobsen, Bodil Lund

    2002-01-01

    Inulin-type fructans, which are nondigestible carbohydrates, have been shown to modulate the number of induced preneoplastic lesions in the colon as well as the colonic microflora in laboratory animals. The present study was designed to investigate the effect of a short- and long-chained inulin-type fructan on 1,2-dimethylhydrazine dihydrochloride-induced aberrant crypt foci (ACF) in the rat colon. In addition, the present study investigated the influence of chain length, dietary level (5% or 15%), and duration of feeding (5 or 10 wk) on the following intestinal parameters supposed to be involved in the development of ACF: microflora, short-chain fatty acids, pH, and cell proliferation. A 3-wk pretreatment period with both fructans was included. Feeding the long-chained fructan (5% or 15%) significantly inhibited the numbers of small and total ACF after 5 and 10 wk. The short-chained fructan (15%) inhibited the number of small and total ACF after 5 and 10 wk but significantly increased the numbers of medium and large ACF after 10 wk. In conclusion, the effect on ACF outcome was influenced by the chain length of the fructans. PMID:12416260

  5. Novel genes encoding six kinds of three-finger toxins in Ophiophagus hannah (king cobra) and function characterization of two recombinant long-chain neurotoxins

    PubMed Central

    Li, Jing; Zhang, Huayuan; Liu, Jing; Xu, Kangsen

    2006-01-01

    Three-finger toxins are a family of low-molecular-mass toxins (<10 kDa) having very similar three-dimensional structure