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Terms modified by C18 Selected AbstractsIntegrated Microanalytical System Coupling Permeation Liquid Membrane and Voltammetry for Trace Metal Speciation.ELECTROANALYSIS, Issue 10 2004Optimization, Technical Description Abstract A new minicell coupling the liquid-liquid extraction technique called permeation liquid membrane (PLM) with an integrated Ir-based Hg-plated microelectrode array for voltammetric detection has been developed for the speciation of heavy metals in natural waters. Lead and cadmium have been used as model compounds. The PLM consists of a carrier (0.1,M 22DD+0.1,M lauric acid) dissolved in 1,:,1 mixture of toluene/phenylhexane held in the small pores (30,nm) of a hydrophobic polypropylene membrane (Celgard 2500). One side of this membrane is in contact with a flowing source solution, containing the metal ions of interest. An acceptor or strip solution (pyrophosphate) is placed on the other side of the PLM with the microelectrode array placed at 480,,m of the PLM. The analyte is transported by the carrier from the source solution to the strip solution. The originality of the new minicell is that accumulation in the strip solution is voltammetrically followed by the integrated microelectrode array in real time, and at low concentration level, using square-wave anodic stripping voltammetry (SWASV). In order to protect the Hg microelectrodes from the adsorption of the hydrophobic carrier, the microelectrodes are embedded in a thin gel layer (280,,m) of 1.5% LGL agarose gel containing 10% of hydrophobic silica particles C18. The choice of optimum conditions is discussed in details in this article. Due to the very small effective strip volume of the new cell (less than 1,,L), high enrichment factor can be obtained (e.g., 330 for Pb) after 2,hours of accumulation. No deaeration of the solutions is required for SWASV measurements. Detection limits under these conditions are 2,pM and 75,pM for Pb and Cd, respectively, using a voltammetric deposition time of 5,min. In addition, no fouling effects were observed with natural water samples. [source] Analysis of urinary metabolites for metabolomic study by pressurized CECELECTROPHORESIS, Issue 23 2007Guoxiang Xie Abstract A new approach for the metabolomic study of urinary samples using pressurized CEC (pCEC) with gradient elution is proposed as an alternative chromatographic separation tool with higher degree of resolution, selectivity, sensitivity, and efficiency. The pCEC separation of urinary samples was performed on a RP column packed with C18, 5,,m particles with an ACN/water mobile phase containing TFA. The effects of the acid modifiers, applied voltage, mobile phase, and detection wavelength were systematically evaluated using eight spiked standards, as well as urine samples. A typical analytical trial of urine samples from Sprague Dawley (S.D.) rats exposed to high-energy diet was carried out following sample pretreatment. Significant differences in urinary metabolic profiles were observed between the high energy diet-induced obesity rats and the healthy control rats at the 6th,wk postdose. Multivariate statistical analysis revealed the differential metabolites in response to the diet, which were partially validated with the putative standards. This work suggests that such a pCEC-based separation and analysis method may provide a new and cost-effective platform for metabolomic study uniquely positioned between the conventional chromatographic tools such as HPLC, and hyphenated analytical techniques such as LC-MS. [source] Development of HPLC and NACE methods for the simultaneous determination of benzoic and sorbic acids in sour snap beans containing oilELECTROPHORESIS, Issue 22 2007Po Han Abstract The practical methods were developed for the simultaneous determination of benzoic acid (BA) and sorbic acid (SA) in sour snap bean samples containing oil. BA and SA in the samples were extracted by ultrasonication with water, followed by cleanup procedures with precipitation for removing the potential proteins and with petroleum ether liquid,liquid extraction for removing the edible oil contained in the samples. The HPLC method was developed using Supelco C18 (250,mm×4.6,mm id, 5,,m) as column, MeOH,20,mM NH4Ac (25:75 v/v) at 1.0,mL/min as the mobile phase and 230,nm as the detection wavelength. The optimal NACE method was established with a running buffer of 20.0,mM NH4Ac in 95% MeOH (pH*,10.6), and an applied voltage of ,30,kV over a capillary of 50,,m id×48.5,cm (40,cm to the detector window), which gave a baseline separation of BA and SA, and as well as of the blank matrix within ca. 10,min. Both HPLC and NACE methods gave the relatively lower limits of quantification at about 0.01,0.02 and 0.04,0.05,mg/kg, respectively, whereas the overall recoveries were larger than 85.0%. The proposed methods have been successfully applied to measure 15 real sour bean samples and the content profile of BA and SA in sour bean samples was obtained and evaluated. [source] Separation of Nile Blue-labelled fatty acids by CE with absorbance detection using a red light-emitting diodeELECTROPHORESIS, Issue 8 2007Michael C. Breadmore Dr. Abstract The separation of fatty acids derivatised with Nile Blue (NB) by CE with detection using a red light-emitting diode (LED) was examined. NB was selected as the derivatisation agent due to its high molar absorption coefficient of 76,000,M,1cm,1 at 633,nm, making it well suited for sensitive absorbance detection using a red 635,nm LED. NB-labelled fatty acids were separated by both MEKC using SDS micelles, i -PrOH and n -BuOH and by NACE in a number of solvents including MeOH, EtOH and ACN. The sensitivity of NACE was superior to MEKC, with detection limits of 5×10,7,7×10,7,M obtained for each acid, approximately 20 times lower than the MEKC method. The NACE detection limits are approximately 100 times lower than previous reports on the separation of fatty acids by CE using indirect absorbance detection, ten times lower than using indirect fluorescence detection and are inferior only to those obtained using precapillary derivatisation and direct fluorescence detection. The efficiency of the NACE method was also superior to MEKC and allowed the separation of unsaturated fatty acids to be examined, although it was not possible to baseline-resolve linoleic (C18:2) and linolenic (C18:3) acids in a reasonable time. The method was used to analyse the fatty acid profile of two edible oils, namely sunflower and sesame oils, after alkali hydrolysis, where it was possible to identify both the saturated and unsaturated fatty acids in each sample. [source] Capillary electrochromatography with monolithic silica column:,I.ELECTROPHORESIS, Issue 3 2003Preparation of silica monoliths having surface-bound octadecyl moieties, applications to the separation of neutral, charged species, their chromatographic characterization Abstract Monolithic silica columns with surface-bound octadecyl (C18) moieties have been prepared by a sol-gel process in 100 ,m ID fused-silica capillaries for reversed-phase capillary electrochromatography of neutral and charged species. The reaction conditions for the preparation of the C18-silica monoliths were optimized for maximum surface coverage with octadecyl moieties in order to maximize retention and selectivity toward neutral and charged solutes with a sufficiently strong electroosmotic flow (>,2 mm/s) to yield rapid analysis time. Furthermore, the effect of the pore-tailoring process on the silica monoliths was performed over a wide range of treatment time with 0.010 M ammonium hydroxide solution in order to determine the optimum time and conditions that yield mesopores of narrow pore size distribution that result in high separation efficiency. Under optimum column fabrication conditions and optimum mobile phase composition and flow velocity, the average separation efficiency reached 160,000 plates/m, a value comparable to that obtained on columns packed with 3 ,m C18-silica particles with the advantages of high permeability and virtually no bubble formation. The optimized monolithic C18-silica columns were evaluated for their retention properties toward neutral and charged analytes over a wide range of mobile phase compositions. A series of dimensionless retention parameters were evaluated and correlated to solute polarity and electromigration property. A dimensionless mobility modulus was introduced to describe charged solute migration and interaction behavior with the monolithic C18-silica in a counterflow regime during capillary electrochromatography (CEC )separations. The mobility moduli correlated well with the solute hydrophobic character and its charge-to-mass ratio. [source] Acute toxicity of fatty acids to the freshwater green alga Selenastrum capricornutumENVIRONMENTAL TOXICOLOGY, Issue 5 2003Yasushi Kamaya Abstract The acute toxicity of fatty acids (C14 to C18) commonly found in wood was determined by the standard algal growth inhibition test using the freshwater green alga Selenastrum capricornutum. Toxicity, quantified as IC50 values, varied depending on the number of total carbons and double bonds. Of the tested acids, oleic (cis -9-octadecenoic) acid showed the highest toxicity (72-h IC50 = 0.47 mg/L) to the alga, and triolein, a triglyceride of oleic acid, showed no apparent toxicity. Further examination of a series of C18:1 acids with a double bond at the 6, 11, or 12 position revealed that both double-bond position and cis or trans configuration affected toxicity. The 72-h IC50 data for these fatty acids and related compounds seemed to correlate well with the melting point (mp), showing two separate linear relationships: at mp < 35°C toxicity increased with increasing melting point, and at mp > 40°C toxicity decreased with melting point. © 2003 Wiley Periodicals, Inc. Environ Toxicol 18: 289,294, 2003. [source] Partitioning of copper at concentrations below the marine water quality criteria,ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 5 2001Anthony J. Paulson Abstract Partitioning of Cu between the aqueous and particulate phases and among their components was examined in six ambient Puget Sound, Washington State, USA, samples (6,10 nM Cu). Most of the particulate Cu (4,12% of the total Cu) was associated with particulate organic matter, and resulted in distribution coefficients (Kd) ranging between 104,55 and 105,1. For the dissolved phase, the portion of Cu extracted by C18 -packed cartridges averaged 44% (+ 11%). Radioactive 64Cu was added to these samples to total stable Cu concentrations (17,33 nM). After 24 h of equilibration, the portion of 64Cu associated with the particulate matter in five of the six samples (Kd between 1047 and 1053) was an average of 70% higher than that of natural Cu in the ambient samples. In contrast, only 19 ± 7% of the 64Cu was extracted by C18 -packed cartridges. The partitioning of natural Cu and 64Cu onto particles was not significantly different when the equilibria were based on dissolved Cu passing through the C18 cartridges. Further research is warranted on utilizing the hydrophilic component of the dissolved phase as a parameter on which water quality criteria are based. [source] Polycyclic aromatic hydrocarbons, aliphatic hydrocarbons, trace elements, and monooxygenase activity in birds nesting on the North Platte River, Casper, Wyoming, USAENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 3 2001Thomas W. Custer Abstract Tree swallow (Tachycineta bicolor) and house wren (Troglodytes aedon) eggs and chicks were collected near a refinery site on the North Platte River, Casper, Wyoming, USA and at a reference site 10 km upstream. Total polycyclic aromatic hydrocarbon (PAH) concentrations in swallow and wren chicks were higher at the refinery site than at the reference site. Polycyclic aromatic hydrocarbon concentrations in sediment and chick dietary samples were consistent with these findings. The general lack of methylated PAHs in sediment, diet, and bird carcasses suggested that the PAHs were derived from combustion and not from petroleum. The predominance of odd-numbered aliphatic hydrocarbons and the low ratios (,0.25) of pristane:n -C17 and phytane:n -C18 in chick and diet samples also suggested that swallow and wren chicks were not being chronically exposed to petroleum. Mean ethoxyresorufin- O -dealkylase and benzyloxyresorufin- O -dealkylase activities in tree swallow livers averaged nine times higher at the refinery site than at the reference site and were probably induced by exposure to PAHs. Trace element concentrations in eggs and livers of swallows and wrens were similar or greater at the reference site than at the refinery site. Selenium, strontium, and boron concentrations were elevated in eggs and livers of swallows and wrens at both the refinery and reference sites. [source] Structure,activity relationships for acute and chronic toxicity of alcohol ether sulfatesENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 3 2000Scott D. Dyer Abstract Acoholethersulfates(AES)areanionicsurfactantscommonlyusedinconsumerproducts. Commercial AES alkyl chain lengths range from C12 to C18, with ethoxylate (EO) units ranging from 1 to 5. Alkyl sulfate is a special case of AES with no EO units. Acute and chronic toxicity tests using Ceriodaphnia dubia via a novel flowthrough method were conducted with 18 AES compounds to derive SARs for effects assessment. In general, acute toxicity (48-h LC50) increased with increased alkyl carbon chain length and decreased with increased numbers of EO units. Parabolic structure,chronic (7-d) toxicity relationships were observed for endpoints such as the no-observed-effect concentration, lowest-observed-effect concentration, maximum acceptable toxicant concentration, EC20, and EC50. A linear relationship of the fractional negative-charged surface area (FNSA-3) with acute toxicity was also determined. FNSA-3 refers primarily to the polar head group of AES and secondarily to the alkyl chain. Seventy percent of the variance in the chronic data was addressed with a quadratic equation relating toxicity to alkyl chain length and EO units. Alternatively, the molecular descriptors FNSA-3 and S3P (3,p, which is the simple, third-order path index) were also found to address most of the data nonlinearity. A chronic test conducted with a mixture of four AES components indicated additivity, leading to the support of the performance of an effects assessment of AES as a mixture. [source] Effects of Valproate on Acylcarnitines in Children with Epilepsy Using ESI-MS/MSEPILEPSIA, Issue 1 2007Tamara Werner Summary:,Purpose: To determine the influence of valproate (VPA) treatment on acylcarnitines in children with epilepsy. Methods: Determination of acylcarnitines (including free carnitine and acylcarnitines from C2 to C18) in dried blood spot specimens using tandem-mass spectrometry. Longitudinal study of changes in acylcarnitines in children under VPA treatment without pretreatment (group 1) or with pretreatment with other antiepileptic drugs (group 2) before the start of VPA treatment at an early and a late treatment interval (12,66, 90,260 days after the beginning of treatment, respectively). Cross-sectional comparison of these two VPA groups and of a group receiving carbamazepine monotherapy (group 3) with controls. Results: Acylcarnitines in epileptic patients before VPA therapy did not differ from control values. In group 1, decreases of C0 (,26%), C2 (,12%), C16 (,31%), C18 (,41%), Ctotal (,10%), increases of C5OH (+31%), C8 (+33%) in the early treatment interval, and decreases of C16 (,21%), C18 (,42%), and increases of C2 (+26%), C5OH (+44%) in the late treatment interval were significant. In group 2, both in the longitudinal and the cross-sectional study, only a decrease of C18 (,41%, ,43%, respectively) in the late treatment interval was found. In group 3, no significant changes have been observed. Conclusions: We could prove changes in acylcarnitine subspecies, which were associated with VPA treatment in children with epilepsy. The treatment interval with the most marked changes coincides with the interval of highest risk for VPA-induced hepatotoxicity. The observed specific acylcarnitine pattern might point to the impaired intermediary metabolism that is responsible for VPA-induced hepatotoxicity. [source] Fatty acid incorporation in endothelial cells and effects on endothelial nitric oxide synthaseEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 9 2007S. Couloubaly Abstract Background The nature of fatty acids provided by the diet as well as plasma lipid metabolism can modify the composition and properties of plasma membrane and thus the activity of membrane proteins. In humans, as well as in experimental models, diabetes is associated with both an alteration in serum lipid profile and a documented endothelial dysfunction. This in vitro study investigated on an immortalized human endothelial cell line (EA.hy 926) the specific effects of several free fatty acids (FFAs) on the composition of cellular membranes and the regulation of endothelial nitric oxide synthase (eNOS). Materials and methods 0·1% of lipid deprived serum was added to the incubation medium with 25 mm glucose in order to study the effects of individual fatty acids: myristic acid, palmitic acid, stearic acid, oleic acid or linoleic acid at 100 µm bound with albumin. The effects of the FFAs on the endothelial nitric oxide synthase were investigated on mRNA level by quantitative PCR, on protein level and Ser1177 phosphorylation by Western blot and on enzymatic activity on living cells using radiolabelled arginine. Results Free linoleic acid increased the membrane content in n-6 fatty acids (mainly C18: n-6 and its metabolites) with a decrease in saturated and monounsaturated fatty acids. These conditions decreased the basal eNOS activity and reduced the phosphorylation of eNOS-Ser1177 due to activation by histamine. Free palmitic acid enriched the membranes with 16 : 0 with a slight decrease in monounsaturated fatty acids. These conditions increased eNOS activation without increasing Ser1177 phosphorylation upon histamine activation. The addition of the other FFAs also resulted in modifications of membrane composition, which did not to affect eNOS-Ser1177 phosphorylation. Conclusion Among the fatty acids used, only modification of the membrane composition due to linoleic acid supply disturbed the basal enzymatic activity and Ser1177 phosphorylation of eNOS in a way that limited the role of histamine activation. Linoleic acid might involve the dysfunction of both eNOS basal activity and its phosphorylation status and may then contribute to an impaired vasodilatation in vivo. [source] Oxidative stability and acceptability of camelina oil blended with selected fish oilsEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 8 2010Deirdre Ní Eidhin Abstract The effects of blending camelina oil with a number of fish oils on oxidative stability and fishy odour were evaluated. Camelina oil was found to be more stable than tuna oil, ,omega-3' fish oil and salmon oil as indicated by predominantly lower ,-anisidine (AV), thiobarbituric acid reactive substances (TBARS) and conjugated triene levels (CT) during storage at 60,°C for 20,days (p,<,0.05). Peroxide values (PV) were similar for all oils until Day 13 when values for camelina oil were higher. Values for blends of the fish oils (50, 25, 15, 5%) with camelina oil were generally between those of their respective bulk oils indicating a dilution effect. Camelina oil had a similar odour score (p,<,0.05) to sunflower oil (9.2 and 9.6, respectively) indicating, as expected, an absence of fishy odours. In comparison, the fish oils had lower scores of 6.1 to 6.6 (p,<,0.05) indicating mild to moderate fishy odours. Odour scores were improved at the 25% fish oil levels (p,<,0.05) and were not different to camelina oil at the 15 or 5% levels (p,<,0.05). Practical applications: Camelina oil is a potentially important functional food ingredient providing beneficial n-3 PUFA. Oil extracted from Camelina sativa seeds contains greater than 50% polyunsaturated fatty acids of which 35-40% is ,-linolenic acid (C18:3,3, ALA), an essential omega-3 fatty acid 1. While EPA and DHA from fish oils are more potent nutritionally, they are less stable than ALA. This work evaluated innovative blends of fish oil with camelina oil for stability and acceptability. The results demonstrate that there is potential for use of blends of camelina oil with fish oils in food products, as the results show some benefits in terms of reduction of fishy odours. Such information could be valuable in relation to formulation of food products containing high levels of n-3 PUFA from both plant and fish sources. [source] Polymers from renewable resources: Bulk ATRP of fatty alcohol-derived methacrylatesEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 9 2008Gökhan Çayli Abstract Copper-mediated atom transfer radical polymerization (ATRP) of lauryl methacrylate (LMA) and other long-chain methacrylates was investigated in bulk at 35,°C by using CuCl/N,N,N,,N,,N,, -pentamethyldiethylenetriamine (PMDETA)/tricaprylylmethylammonium chloride (Aliquat®336) as the catalyst system and ethyl 2-bromoisobutyrate (EBIB) as the initiator. The investigated monomers can be derived from fatty alcohols and are therefore an important renewable resource for a sustainable development of our future. The amounts of ligand, Aliquat®336 and CuCl were optimized and the effect of their concentrations on the control of the polymerization and the observed conversions were investigated. It was found that a molar ratio of EBIB/CuCl/Ligand/Aliquat®336 of 1,:,1,:,3,:,1 provided the highest conversions of LMA and the best controlled polymerizations. These optimized conditions allowed for the synthesis of poly(lauryl methcarylate)s with different targeted DP (25, 50, 75, 100, 120, 240, and 500), including high-molecular-weight polymers with narrow molecular weight distributions. In addition, methacrylate monomers were prepared from fatty alcohols (capric, myristic, palmitic, stearic) and polymerized using the developed procedure to obtain polymers with the same DP and different chain lengths (C10, C12, C14, C16, and C18) of pending alkyl groups. Finally, the thermal properties of these polymers were examined by differential scanning calorimetry and thermogravimetric analysis. [source] Altered fatty acid pattern of phospholipids and triglycerides in the submandibular gland of ,3-depleted ratsEUROPEAN JOURNAL OF ORAL SCIENCES, Issue 2 2007Christine Delporte Alteration of the phospholipid (PL) and triglyceride (TG) fatty acid pattern was recently documented in several organs of rats depleted in long-chain polyunsaturated ,3 fatty acid (,3 rats). This study extends such a knowledge to the submandibular gland. The total PL and TG content of the salivary gland was not different in control and ,3 rats. The sole ,3 fatty acids found in ,3 rats (C22:5,3 and C22:6,3) were present at levels 3,12 times lower than in control rats. The C22:5,3/C22:6,3 ratio was increased threefold in ,3 rats. The PL and TG C16:0/C16:1,7 and C18:0/C18:1,9 ratios were decreased in ,3 rats. The conversion of C18:2,6 to C20:4,6 and C22:4,6 appeared facilitated in the ,3 rats. Some of these rats were injected intravenously, 60,120 min before killing, with either a medium-chain triglyceride:fish oil emulsion or a control medium-chain triglyceride:olive oil emulsion. The former emulsion increased the PL C22:5,3 and C22:6,3 content and prevented the age-related decrease in C16:0/C16:1,7 and C18:0/C18:1,9 ratios otherwise also recorded in PL. In conclusion, these findings document an increased activity of ,9-desaturase, a more efficient conversion of C18:2,6 to its metabolites, and an impaired generation of C22:6,3 from C22:5,3 in ,3 rats. [source] Synthesis of the L-Acid (C1,C18) Fragment of Pamamycin-593 and De- N -methylpamamycin-579EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 29 2008Ayako Miura Abstract The L-acid (C1,C18) fragment of pamamycin-593 and de- N -methylpamamycin-579, strong aerial mycelium-inducers of Streptomyces alboniger, was synthesized using a cis -selective iodoetherification and a nucleophilic addition of a cerium acetylide to an aldehyde as the key steps. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source] Sulfatide with short fatty acid dominates in astrocytes and neuronsFEBS JOURNAL, Issue 8 2006Giorgis Isaac Glycosphingolipids are located in cell membranes and the brain is especially enriched. We speculated that the subcellular location of glycosphingolipids depends on their fatty acid chain length because their sugar residues are constant, whereas fatty acid chain length can vary within the same molecule. To test this hypothesis we analysed the glycosphingolipid sulfatide, which is highly abundant in myelin and has mostly long fatty acids. We used a negative ion electrospray tandem mass spectrometry precursor ion scan to analyse the molecular species of sulfatide in cultured astrocytes and a mouse model of the human disease metachromatic leukodystrophy. In these arylsulfatase A (ASA)-deficient mice sulfatide accumulates intracellularly in neurons and astrocytes. Immunocytochemistry was also performed on cultured astrocytes and analysed using confocal laser scanning microscopy. Analyses of the molecular species showed that cultured astrocytes contained sulfatide with a predominance of stearic acid (C18), which was located in large intracellular vesicles throughout the cell body and along the processes. The same was seen in ASA-deficient mice, which accumulated a higher proportion (15 mol% compared with 8 mol% in control mice) of sulfatide with stearic acid. We conclude that the major fatty acid composition of sulfatide differs between white and grey matter, with neurons and astrocytes containing mostly short-chain fatty acids with an emphasis on stearic acid. Based on our results, we speculate that the fatty acid chain length of sulfatide might determine its intracellular (short chain) or extracellular (long chain) location and thereby its functions. [source] Vibrio owensii sp. nov., isolated from cultured crustaceans in AustraliaFEMS MICROBIOLOGY LETTERS, Issue 2 2010Ana Cano-Gómez Abstract Two bacterial strains (DY05T and 47666-1) were isolated in Queensland, Australia, from diseased cultured crustaceans Panulirus ornatus and Penaeus monodon, respectively. On the basis of 16S rRNA gene sequence identity, the strains were shown to belong to the Harveyi clade of the genus Vibrio. Multilocus sequence analysis using five housekeeping genes (rpoA, pyrH, topA, ftsZ and mreB) showed that the strains form a monophyletic group with 94.4% concatenated sequence identity to the closest species. DNA,DNA hybridization experiments showed that strains DY05T and 47666-1 had 76% DNA similarity to each other, but <70% to their closest neighbours Vibrio harveyi LMG 4044T (,55%), Vibrio campbellii LMG 11216T (,52%) and Vibrio rotiferianus LMG 21460T (,46%). Strains DY05T and 47666-1 could be differentiated from their relatives on the basis of several phenotypic characteristics. The major fatty acids were C15:0 iso 2-OH and/or C16:1,7, C16:0, C18:1,7 and C14:0. Based on the polyphasic evidence presented here, it can be concluded that strains DY05T and 47666-1 belong to the same novel species of the genus Vibrio, for which the name Vibrio owensii sp. nov. is proposed. The type strain is DY05T (=JCM 16517T=ACM 5300T). [source] Significance of the KlLAC1 gene in glucosylceramide production by Kluyveromyces lactisFEMS YEAST RESEARCH, Issue 6 2008Naoya Takakuwa Abstract Each of the 12 genes involved in the synthesis of glucosylceramide was overexpressed in cells of Kluyveromyces lactis to construct a strain accumulating a high quantity of glucosylceramide. Glucosylceramide was doubled by the KlLAC1 gene, which encodes ceramide synthase, and not by 11 other genes, including the KlLAG1 gene, a homologue of KlLAC1. Disruption of the KlLAC1 gene reduced the content below the detection level. Heterologous expression of the KlLAC1 gene in the cells of Saccharomyces cerevisiae caused the accumulation of ceramide, composed of C18 fatty acid. The KlLAC1 protein preferred long-chain (C18) fatty acids to very-long-chain (C26) fatty acids for condensation with sphingoid bases and seemed to supply a ceramide moiety as the substrate for the formation of glucosylceramide. When the amino acid sequences of ceramide synthase derived from eight yeast species were compared, LAC1 proteins from five species producing glucosylceramide were clearly discriminated from those of the other three species and all LAG1 proteins. The LAC1 protein of K. lactis is the enzyme that plays a crucial role in the synthesis of glucosylceramide. [source] Time-of-flight secondary ion mass spectrometry analysis of the application of a cationic conditioner to ,clean' hairINTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Issue 5 2004A. Harvey In this study the applicability of the surface-sensitive Time-of-flight secondary ion mass spectrometry (ToF-SIMS) technique to hair analysis and associated aqueous processing is evaluated. ToF-SIMS analysis of ,as received' human hair indicates the presence of silicones, anionic surfactants, and cationic conditioners, from previous treatments, on the fiber surface. Cleaning of the hair with SLS or SLES results in adsorption of the surfactants onto the fiber surface. In particular, the more non-polar surfactant components have greater substantivity for the fiber surface, as indicated by the relative increase in their ToF-SIMS intensity. Application of the Incroquat Behenyl 18-MEA conditioner to both ,virgin' and bleached hair results in the adsorption of the cationic C18, C20, C22, and C21 surfactant components onto the hair surface. The ToF-SIMS data indicate higher levels of conditioner on the bleached hair relative to the undamaged hair. [source] Some chemical and microbiological properties of ghee produced in Eastern AnatoliaINTERNATIONAL JOURNAL OF DAIRY TECHNOLOGY, Issue 3 2008AYSEGUL KIRAZCI Some properties of 30 ghee samples produced in Eastern Anatolia in Turkey were evaluated. Lipolytic bacteria and yeast,mould counts ranged from undetectable to 9.9 × 105 and 6.9 × 105 cfu/g, respectively. Most of the samples showed higher free fatty acids (FFA) and peroxide values (PV) than the limits mentioned in International Dairy Federation standards. Storage at 5°C for 30 days was not sufficient to stop the lipolytic and yeast,mould growth and lipid oxidation of the samples. Ghee samples with considerably higher trans -C18 : 1 and trans -C18 : 2 fatty acids contents were considered to be adulterated with hydrogenated oils. It is recommended that specific attention should be given to technology transfer and the education of traditional dairy product manufacturers. [source] Lipid compounds of human Wharton's jelly and their alterations in preeclampsiaINTERNATIONAL JOURNAL OF EXPERIMENTAL PATHOLOGY, Issue 1 2010Lech Romanowicz Summary Wharton's jelly is a myxomatous substance which surrounds the umbilical cord vessels protecting them against extension, bending, twisting and compression. Very low number of cells in this tissue produce high amounts of extracellular matrix; collagen, hyaluronate and proteoglycans which bind large quantities of peptide growth factors (PGFs). Preeclampsia (the most common pregnancy-associated syndrome) is accompanied by a significant reduction in hyaluronate and a concomitant increase in sulphated glycosaminoglycans/proteoglycans content in Wharton's jelly. Such a phenomenon corresponds to an ,early ageing' of this tissue. We have evaluated the lipid composition of Wharton's jelly and its alteration in preeclampsia. Thin layer chromatography and high-performance liquid chromatography were employed. It was found that Wharton's jelly contains free fatty acids (FFA), mono-, di- and triacylglycerols, free cholesterol and its esters. The characteristic feature is the presence of relatively high amounts of unsaturated fatty acids, including those (C18:2 and C18:3) which are nutritionally essential. Preeclampsia is associated with a slight increase in the total fatty acid content in Wharton's jelly and with marked changes in the proportional relationships between various lipids. A distinct decrease in the amounts of FFA was observed with a concomitant increase in monoacylglycerols and cholesterol esters. At least in some cases the effects exerted by PGFs are mediated by the lipid second messengers. Thus it is possible that alterations in lipid compounds of Wharton's jelly may participate in the deregulation of various cell functions, including overproduction of sulphated glycosaminoglycans or down-regulation of enzymes which participate in their degradation. [source] Detecting vegetable oil adulteration in hazelnut paste (Corylus avellana L.)INTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 3 2009Josep Serra Bonvehi Summary The possibilities of detecting hazelnut paste adulterated with refined and non-refined vegetable oils have been studied. Research was focussed mainly on peanut, high oleic-acid sunflower, corn and soybean oils which have a similar composition to hazelnut oil. The analytical procedures to detect fatty acid (FA), triacylglycerol (TAG) and tocopherol profiles as indicators of adulteration were determined. The better indicators experimentally determined were seven FA (palmitic, stearic, linoleic, linolenic, arachidonic, behenic and lignoceric acids) and different TAG with three unsaturated FA (the code letters used for FA are: P = C16:0; S = C18:0; O = C18:1; L = C18:2;; Ln = C18:3) (LLLn, LLL and OOO), two unsaturated FA (POL, PLL and SOO), and one unsaturated FA (PPL). As expected, when refined vegetable oils were added to hazelnut paste, the increment of stigmasta-3,5-diene allowed detection at levels of 2% oil added. Limits of detection were measured using standard and adulterated hazelnut with different amounts of non-refined vegetable oils added (5%, 10%, 20% and 30%). The distribution of tocopherols and tocotrienols is highly useful, except in the case of added sunflower oil. The differences between the experimental and theoretical values of the TAG with equivalent carbon number (,ECN) of 42 does not improve the detection limit of hazelnut paste adulterated with peanut or sunflower oils. Similarly, tocopherols usually added to refined vegetable oils as an antioxidant were also determined. [source] Wheat Cellular Membrane Thermotolerance Under Heat StressJOURNAL OF AGRONOMY AND CROP SCIENCE, Issue 2 2010A. S. Dias Abstract Four genotypes of Triticum aestivum L. and Triticum turgidum subsp. durum chosen according to their genetic background diversity were subjected to heat stress after anthesis. Membrane permeability, lipid peroxidation and fatty acids (C14:0, C16:0, C16:1c, C16:1t, C18:0, C18:1, C18:2 and C18:3) were quantified. The estimation of the quantum yield of non-cyclic photosynthetic electron transport was used as well as a test system to further evaluate the implications on thylakoid functioning. It was found differences within bread and durum wheat species concerning the capability to cope with high temperatures at the stage of grain filling. The genotype Sever showed high thermal sensitivity concerning membrane lipid peroxidation and membrane permeability, as evaluated by the increased production of ethylene and MDA, as well as by the impact on TFA (at the middle term of grain filling). In the durum wheat genotypes, differences were also found, with TE 9306 displaying high membrane stability, with no increases on membrane permeability, MDA and ethylene content. In this way, the observed changes on TFA in this genotype might have constituted a mechanism to allow qualitative lipid changes, reflected in lower unsaturation level of membrane FAs which is a positive trait under high temperatures. [source] The influence of dietary linoleic and , -linolenic acid on body composition and the activities of key enzymes of hepatic lipogenesis and fatty acid oxidation in mice,JOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 1-2 2007M. Javadi Summary We have recently suggested that feeding the C18 polyunsaturated fatty acid, , -linolenic acid (ALA), instead of linoleic acid (LA) reduced body fat in mice. However, the difference in body fat did not reach statistical significance, which prompted us to carry out this study using more animals and diets with higher contents of ALA and LA so that the contrast would be greater. The diets contained either 12% (w/w) LA and 3% ALA or 12% ALA and 4% LA. A low-fat diet was used as control. The diets were fed for 35 days. The proportion of body fat was not influenced by the type of dietary fatty acid. Plasma total cholesterol and phospholipids were significantly lower in ALA-fed mice than in mice fed LA. Activities of enzymes in the fatty acid oxidation pathway were significantly raised by these two diets when compared with the control diet. , -Linolenic acid vs. LA did not affect fatty acid oxidation enzymes. In mice fed the diet with LA activities of enzymes of de novo fatty acid synthesis were significantly decreased when compared with mice fed the control diet. , -Linolenic acid vs. LA feeding did not influence lipogenic enzymes. It is concluded that feeding mice for 35 days with diets either rich in LA or ALA did not significantly influence body composition. [source] Effect of dietary linoleic acid concentration and vitamin E supplementation on cell desquamation and susceptibility to oxidative damage of pig jejunal mucosaJOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 1-2 2001C. J. López Bote Sixty Large White × Great York pigs weighing approximately 60 kg were individually fed on six experimental diets. The experiment was organized in a 3 × 2 factorial arrangement design with three different fat sources and a basal or supplemented (200 mg/kg diet) level of ,-tocopheryl acetate. All diets contained the same concentration of saturated fatty acids (15 ± 0.2 g/kg dry matter) but differed in the concentration of C18 : 2 (14 ± 0.5, 18 ± 0.4 and 21 ± 0.6 g/kg) and monounsaturated fatty acids (19 ± 0.2, 15 ± 1.2 and 10 ± 1.3 g/kg). No effect of dietary treatment was observed on weight gain and feed consumption. A histological study of the jejunal mucosa showed lower cell desquamation in groups containing a supplemental level of ,-tocopheryl acetate (p=0.080). A higher cell desquamation was found in the groups fed diets containing the higher concentration of C18 : 2 (p=0.087). We also observed an interaction effect (p < 0.001) of dietary fat source and vitamin E supplementation on jejunal cell desquamation in which the effect of dietary vitamin E was lower when diets with a low concentration of C18 : 2 were administered. In vitro- induced oxidation of jejunal mucosa homogenates was lower in pigs fed diets supplemented with ,-tocopheryl acetate (p < 0.002). The dietary concentration of C18 : 2 significantly affected oxidation of pig jejunal mucosa (p < 0.002). [source] An oil-degrading bacterium: Rhodococcus erythropolis strain 3C-9 and its biosurfactantsJOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2007F. Peng Abstract Aims:, To isolate a biosurfactant-producing bacterium and find new products within its culture. Methods and Results:, A biosurfactant-producing bacterium identified as Rhodococcus erythropolis (3C-9 strain) was isolated from seaside soil. When n -hexadecane was supplied as the sole carbon source, two types of biosurfactants (free fatty acids and glycolipids) were detected in the supernatant of the bacterial culture by use of thin layer chromatography (TLC). Gas chromatography,mass spectrometry (GC,MS) analysis revealed that the former consisted of at least 12 free fatty acids of chain lengths from C9 to C22; and the latter contained 2 kinds of glycolipids (a glucolipid and a trehalose lipid), which were detected by use of TLC, as well as GC,MS. The hydrophobic moieties of both glycolipids consisted of seven types of straight-chain fatty acids of varying compositions, with chain lengths ranging from C10 to C18. It was also noted that biosurfactants of strain 3C-9 were produced in a manner that was growth-related and cannot be synthesized from water-soluble substrates. The effects to enhance the solubility of polycyclic aromatic hydrocarbons and the degradation rate of hexadecane were also tested. Conclusions:, The biosurfactants produced by strain 3C-9 of R. erythropolis included two kinds of glycolipids, as well as free fatty acids. These biosurfactants were notably different from those of previously reported Rhodococcus species, both in terms of their structure and chemical composition. Significance and Impact of the Study:, Strain 3C-9 of R. erythropolis is a competitive candidate for use in oil spill cleanup operations, or in new biosurfactant exploration. The findings in this report show that Rhodococcus is a natural reservoir of new biosurfactants. [source] Bile salts and cholesterol induce changes in the lipid cell membrane of Lactobacillus reuteriJOURNAL OF APPLIED MICROBIOLOGY, Issue 1 2003M.P. Taranto Abstract Aims: The objective of this study was to evaluate the effect of bile salts and cholesterol in the lipid profile of Lactobacillus reuteri CRL 1098 and to determine the relationship existing between these changes: the in vitro removal of cholesterol and the tolerance of the cells to acid and cold stress. Methods and Results:Lactobacillus reuteri CRL 1098 was grown in the following media: MRS (deMan Rogosa Sharpe; MC, control medium), MB (MC with bile salts), MCH (MC with sterile cholesterol) and MBCH (MC with bile salts and cholesterol). Fatty acids were determined by analytical gas,liquid chromatography, and phospholipids and glycolipids by colorimetric techniques. The cells from different culture media were subjected to cold and acid stress. The MB cultures displayed a decrease in phospholipids and a low ratio of saturated : unsaturated fatty acids. The presence of the unusual C18 : 0,10-OH and C18 : 0,10-oxo fatty acids was the prominent characteristic of the bile salts growing cells. The relative increase in glycolipids and the changes in the fatty acids profiles of the MB cells would be responsible for the cholesterol remotion. The changes induced by bile salts in the lipid profile did not improve the tolerance of L. reuteri CRL 1098 to freezing and acid stress. Conclusions: The changes in lipid profiles reported in this study would play a key role in the response of Lactobacilli to environmental stress. Significance and Impact of the Study: This work provides useful information about the effect of bile salts on the cell membrane of L. reuteri, a probiotic enterolactobacillus. The steady-state response of the cells subjected to bile stress seems to be the appropriate model for evaluating the bacterial behaviour in detergent-containing gastrointestinal tracts, where the bile salts stress would presumably be continuous. [source] Hydrocarbon degradation by thermophilic Nocardia otitidiscaviarum strain TSH1: physiological aspectsJOURNAL OF BASIC MICROBIOLOGY, Issue 6 2007Majid Zeinali Abstract Indigenous thermophilic hydrocarbon degraders are of special significance for the bioremediation of oil-contaminated desert soils with ambient temperature of 45,50 °C. The first objective of this study was to demonstrate the hydrocarbon-degrading capability of Nocardia otitidiscaviarum TSH1 (DSM 45036) which grows optimally at 50 °C. Analysis of the metabolic profile of the strain TSH1 showed that it could metabolize phenol, intermediate-chain-length n -alkanes and some polycyclic aromatic hydrocarbons (PAHs) ranging in size from two to four fused rings efficiently, but not toluene and xylene. N. otitidiscaviarum TSH1 was able to survive and grow at phenol concentrations up to 875 mg l,1. For the first time, the physiological response of a thermophilic Nocardia strain to poorly available hydrophobic compounds was also investigated. When grown on a mineral salt medium with hexadecane, N. otitidiscaviarum TSH1 showed very high affinity for the organic phase. Additionally, PAH-grown cells were considerably hydrophobic. The capacity of PAH-utilizing N. otitidiscaviarum TSH1 isolate to produce biosurfactants was also investigated. Fatty acids (C14,C18) were detected by GC-MS analysis during bacterial growth in PAH supplemented mineral media. High cell surface hydrophobicity and capability of N. otitidiscaviarum TSH1 to degrade different hydrocarbons at 50 °C may make it an ideal candidate to treat oil-contaminated desert soils. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] INHIBITION OF MICROORGANISMS IN SALAD DRESSING BY SUCROSE AND METHYLGLUCOSE FATTY ACID MONOESTERSJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 4 2003CHING-MIAO YANG The antimicrobial activity of sucrose and methylglucose esters of medium to long chain fatty acids was studied with two microorganisms involved in the spoilage of salad dressings, Zygosaccharomyces bailii and Lactobacillus fructivorans. The microorganisms were inhibited to various degrees by 0.1, 0.5, and 1.0% synthesized sucrose or methylglucose monoesters using a modified broth dilution method. Sucrose monoesters were most inhibitory when the esterified fatty acid was myristic (C14) or palmitic acid (C16). Methylglucose monoesters with lauric (C12) or myristic acid (C14) exhibited greater inhibition than those with longer chain fatty acids. The least inhibition was generally observed with sucrose and methylglucose oleate (C18:1). Sucrose monoesters were usually more inhibitory than methylglucose monoesters of the same fatty acid, especially for palmitic and stearic (C18) acids. In salad dressing, 1% sucrose monoesters of lauric, myristic, or palmitic acid significantly (P < 0.05) inhibited the growth of Z. bailii and L. fructivorans, and were comparable with or more effective than 0.1% sodium benzoate. Z. bailii growth was nearly completely inhibited by sucrose laurate, myristate and palmitate by 9 days of salad dressing storage. Sucrose monoesters did not delay the lag phase of L. [source] Fatty Acid Composition of Beef Intermuscular, Sheep Tail, Beef Kidney Fats and Its Effects on Shelf Life and Quality Properties of KavurmaJOURNAL OF FOOD SCIENCE, Issue 2 2009. Aksu ABSTRACT:, The effects of beef intermuscular (BIF), beef kidney (BKF), and sheep tail fats (STF) and storage time on fatty acid composition, the thiobarbituric acid reactive substances (TBARS), free fatty acids (FFA), pH and L*, a*, and b* values, and Enterobacteriaceae counts of sliced vacuum-packaged Kavurma were investigated. Kavurma was made from fresh beef which contained different amounts of melted BIF, BKF, STF, and salt as 10 groups. The Kavurma was sliced 3 to 4 cm thick and was vacuum packed and stored at 4 ± 0.5 °C for 360 d. Animal fat groups (BIF, STF, and BKF) had a statistically significant difference (P < 0.01) in terms of both fatty acid composition and total saturated and unsaturated fatty acids. Used animal fat types and levels in Kavurma production had a significant effect on unsaturated fatty acid composition (except for C18:1n9t) (P < 0.01). C18:1n9c was the dominant fatty acid in all Kavurma groups, and the highest C18:1n9c was determined for 50% STF + 50% BKF (group 6). TBARS and FFA values were affected by the treatment (P < 0.01) and storage time (P < 0.01). The lowest TBARS value was found in group 10 (30% BIF + 35% STF + 35% BKF). There was a significant (P < 0.01) difference in FFA content in Kavurma between 0 and 180 and 360 d, and this value increased during storage time. The a* values of Kavurma decreased during storage, and the greatest decrease was determined between days 0 and 180 of storage. Enterobacteriaceae counts were determined to be under the detectable level in all Kavurma groups during storage. [source] | |||||||||||||||||||||||||||||||||||||