Odd Carbon Chain Research Articles

Simultaneous medium chain carboxylic acids and 1,3-propanediol production in a bioaugmented lactate-based chain elongation induced with glycerol

The objective was to investigate the impact of the bioaugmentation on chain elongation process using glycerol, lactate and lactose as substrates in an open culture fermentation. In the batch trials the highest selectivity for chain elongation product, i.e. caproate, was observed in trials inoculated with co-culture of Megasphaera elsdenii and Eubacterium limosum grown on glycerol (28.6%), and in non-bioaugmented open culture run on lactose + lactate (14.8%). The results showed that E. limosum, out of two bioaugmented strains, was able to survive in the open culture. A continuous open culture fermentation of glycerol led to caproate and 1,3-propanediol (1,3-PDO) formation, while lactate addition led to 1,3-PDO and short chain carboxylates production. Moving the process into batch mode triggered even-carbon chain elongation. Presence of E. limosum promoted odd-carbon chain elongation and valerate production. Imaging flow cytometry combined with machine learning enabled the discrimination of Eubacterium cells from other microbial strains during the process.

2-Heptanone, 2-nonanone, and 2-undecanone confer oxidation off-flavor in cow milk storage

Flavor sensation is one of the most prevalent characteristics of food industries and an important consumer preference regulator of dairy products. So far, many volatile compounds have been identified, and their molecular mechanisms conferring overall flavor formation have been reported extensively. However, little is known about the critical flavor compound of a specific sensory experience in terms of oxidized off-flavor perception. Therefore, the present study aimed to compare the variation in sensory qualities and volatile flavors in full-fat UHT milk (FFM) and low-fat UHT milk (LFM) samples under different natural storage conditions (0, 4, 18, 25, 30, or 37°C for 15 and 30 d) and determine the main component causing flavor deterioration in the FFM and LFM samples using sensory evaluation, electronic nose, and headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS). In addition, the Pearson correlation between the volatile flavor components and oxidative off-flavors was analyzed and validated by sensory reconstitution studies. Compared with the LFM samples, the FFM samples showed a higher degree of quality deterioration with increased storage temperature. Methyl ketones of odd carbon chains (i.e., 2-heptanone, 2-nonanone, 2-undecanone, 2-tridecanone, and 2-pentadecanone) reached a maximum content in the FFM37 samples over 30 d storage. The combined results of the Pearson correlation and sensory recombination study indicated that 2-heptanone, 2-nonanone, and 2-undecanone conferred off-flavor perception. Overall, the present study results provide potential target components for detecting and developing high-quality dairy products and lay a foundation for specific sensory flavor compound exploration in the food industry.

Optimizing Molecular Structure for Trimethylolpropane Ester-Insulating Oil: Achieving High Fluidity and Stability

Synthetic ester exhibits a unique combination of advantages, including remarkable oxidation stability similar to mineral oil, as well as high flash point and biodegradability of natural ester, which makes it a promising insulating fluid alternative for transformers. In this work, a series of medium-chain fatty acid trimethylolpropane (TMP) esters (MTE) were prepared by esterification of a mixture of TMP blended with 3 saturated medium-chain fatty acids (C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">8</sub> , C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">9</sub> , and C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sub> ). The MTEs were synthesized via a vacuum esterification method with the following optimized reaction conditions: 1 wt.% p-toluenesulfonic acid (TsOH) as catalyst, reaction temperature of 120 °C, internal air pressure of 5 kPa, and the acid:TMP molar ratio of 3.2:1. The MTEs were obtained through a rationally designed purification procedure. By characterizing the physical and electrical properties of the 9 MTEs, it is found that the viscosity of MTEs increases with increasing mean molecular weight, the pour point decreases with increasing C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">9</sub> content, and the flash point slightly increases with inscreasing C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sub> content. The C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">8</sub> with a relatively short carbon chain and C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">9</sub> with an odd carbon chain may be beneficial for enhancing the oxidation stability of MTEs, whereas the AC breakdown voltage of the MTEs shows a negligible correlation with the fatty acid ratios.

Revisiting to N‐alkylation of multi‐dentate amines ligand for ATRP

AbstractThe ligands role in normal atom transfer radical polymerization (ATRP) is not only for controlling the system but also regulate the rate of polymerization depending the solubility in the reaction media. Solubility of the catalyst/ligand complexes in organic media is of particular importance to attain homogeneous polymerization conditions. The linear multi‐dentate amine ligands with a long aliphatic chain on the nitrogen atoms provide solubility of its metal complexes in organic solvents. However, the increasing length of the alkyl substituents induces steric effects and can alter the redox potential of the metal center. Herein, to understand the effect of alkyl length, we report the synthesis of tri‐, tetra‐dentate linear amine ligands, diethylenetriamine, triethylenetetramine having n‐alkyl halides containing odd carbon chain lengths (C3H7‐, C5H9‐), respectively. Well‐defined polymers were obtained in ATRP of S and MMA using synthesized ligands. Apparently, increasing the alkyl chain length was sufficient to provide homogeneous ATRP medium, which was not achieved with methyl‐substituted ligands (e.g., pentamethyldiethylenetriamine, PMDETA and hexamethyltriethylenetetramine, HMTETA). In combining ATRP results for odd (synthesized) and even carbon number alkylated ligands (literature), linear decreasing trend was observed on apparent rate constant (kpapp) by the increasing the alkyl chain length.

Synthesis, Structural and Theoretical Analyses of C≡N···I Halogen-Bonded Liquid Crystalline Complexes of 4-Cyano-4′-alkoxy Biphenyl Systems

A series of 4-cyano-4′-alkoxybiphenyl compounds were synthesized by varying the spacer chain lengths (−CH2−)n, where n = 3–10, for the systematic study of a halogen-bonded (XB) complex with 1,4-diiodotetrafluoro benzene. The XB liquid crystalline complexes obtained from the liquid-assisted grinding method were characterized by FTIR, Raman, DSC, and PXRD studies. Further, C≡N···I XB interaction was established by single-crystal X-ray diffraction analysis. The odd-even analysis has suggested that the even carbon chain length containing XB liquid crystalline complexes shows slightly higher alteration in their isotropic temperature compared to the odd carbon chain lengths of such complexes. Furthermore, it is interesting to note that the higher alkyl chain complexes (n = 6–10) showed liquid crystalline temperature at lower values with respect to their ligands. The Hirshfeld and energy framework analyses have also been carried out to assess the stability and percentage contribution of XB noncovalent interaction. The frontier molecular orbital, noncovalent interaction, molecular electrostatic potential, and QTAIM analysis were performed using DFT to evaluate the nature of XB in these halogen-bonded liquid crystalline systems.

Lipidomics of facial sebum in the comparison between acne and non-acne adolescents with dark skin

Lipidomics is advantageous in the study of sebum perturbations occurring in acne. An extended evaluation of the sebum lipid profiles in acne-prone sebaceous areas is lacking in dark skin. Yet, there is a void space in understanding how the building blocks of sebum lipids, i.e. individual fatty acids (FAs), are intertwined with acne-prone skin. We aimed to determine the sebum lipidome in facial areas of adolescents with and without acne in Nigeria. A cross-sectional analytical study was conducted in 60 adolescents/young adults divided in 30 acne patients (15F, 15M) and 30 age and sex-matched controls. Sebum samples obtained from foreheads and cheeks were analysed separately by gas chromatography–mass spectrometry (GCMS) and thin layer chromatography (HPTLC). Distributions of sebum components were investigated with multivariate ANOVA-simultaneous component analysis (ASCA). Sebum incretion in acne was paralleled by significantly higher abundance of triglycerides, wax esters, and squalene together with monounsaturated FAs (MUFAs), and straight chain saturated FAs (SFAs), especially those with odd-carbon chain, i.e. C13:0, C15:0, and C17:0. Profiling weight/weight percentage of individual components revealed that, in acne, the free FAs (FFAs) array was shifted towards higher relative abundance of the SFAs C15:0, C16:0, and C17:0 and lower percentage of the anteiso-branched FFAs with 12, 14, 16, and 18 carbons. In acne patients, MUFAs and PUFAs were quantitatively increased and decreased on foreheads and cheeks, respectively. Relative abundance of fatty alcohols was decreased in acne independent on the site. The results indicated that acne associates with site-specific derangement of the pathways regulating the balance among odd straight-chain and branched-chain SFAs, MUFAs, which included sapienate (C16:1n-10), PUFAs, and squalene.

The effect of cultivar and harvest season on the n-alkane and the n-alkene composition of virgin olive oil

Linear hydrocarbons such as n-alkanes and n-alkenes are contained in the unsaponifiable fraction and are one of the less studied class of components in olive oil. This work was conducted in two subsequent harvest seasons (2016–2017 and 2017–2018) and attentioned the oils of nine olive cultivars: Cassanese, Coratina, Itrana, Leccino, Nociara, Ottobratica, Pendolino, Picholine and Sinopolese grown in the same geographical area (Rizziconi) of the region of Calabria (South Italy). Seven out of the nine cultivars were allochthonous for the geographical area where the experiment was conducted. Height n-alkanes with odd-carbon chain number, seven n-alkanes with even-carbon chain number and three n-alkenes were detected in the following elution order: heneicosane, docosane, tricosene, tricosane, tetracosene, tetracosane, pentacosene, pentacosane, hexacosane, heptacosane, octacosane, nonacosane, triacontane, entriacontane, dotriacontane, tritriacontane, tetratriacontane, pentatriacontane. The cultivar variable produced very high significant differences, this was particularly evident for Sinopolese oil showing a total n-alkanes and n-alkenes content of 260 and 290 mg/kg respectively for the first and the second harvest season, whereas Ottobratica and Picholine oils contained less than 100 mg/kg and Cassanese and Itrana oils contained less than 50 mg/kg. The highest n-alkene content was found in the oil of Ottobratica 1.97–161 mg/kg, Picholine 2.34–1.99 mg/kg and in Sinopolese 1.93–2.91 mg/kg. The odd/even ratio was less than 3 for Picholine and Sinopolese and less than 5 for all other cultivars. Docosane was 12.30 and 17.61 mg/kg for Sinopolese and less than 2 mg/kg for all other cultivars. Harvest season did not influence significantly the n-alkanes and n-alkenes content.

Structural basis of quinolone derivatives, inhibition of type I and II topoisomerases and inquiry into the relevance of bioactivity in odd or even branches with molecular docking study

The structural modification of quinolone derivatives has been a hot spot in recent years, especially the modification of the N-1 position, which is the part that this article focuses on. In this paper, series of synthesized quinoline quaternary ammonium salts with odd and even carbon number alkyl groups in N-1 position were used to explain the influence of the alkyl side chain on activity. With respect to all the recently synthesized twenty products, the biological activity results exhibited significant antitumor and antibacterial activity with obvious differences in the target alkyliodine substituted compounds and the antibacterial activities apparently had the prominent odd-carbon number predominance. Compound 8-((4-(benzyloxy)phenyl)amino)-7-(ethoxycarbonyl)-5-propyl-[1,3]dioxolo[4,5-g]quinolin-5-ium (4d) was found to be the most potent derivative with IC50 values of 4 ± 0.88, 4 ± 0.42, 14±1.96, and 32±3.66 against A-549, Hela, SGC-7901, and L-02 cells, respectively, stronger than the positive control 5-FU and MTX. Furthermore, it had the most potent bacterial inhibitory activity of MIC value against E. coli (ATCC 29213) and Staphylococcus aureus (ATCC 8739) at 3.125 nmol mL−1. With respect to molecular simulations, in order to illustrate the possible mechanism of the difference between the series of compounds in the even or odd carbon chain alkyliodine substitution, this paper simulated the conceivable mode and explained the main interactions. Finally, we could find that the position and proportion of hydrogen bonds and other interactions in each series were regarded as the main reasons for this difference in activity.

Exogenous addition of alkanoic acids enhanced production of antifungal lipopeptides in Bacillus amyloliquefaciens Pc3.

The bacterium, Bacillus amyloliquefaciens Pc3, was previously isolated from Antarctic seawater and has been found to show antagonistic activity against the fungus, Rhizoctonia solani ACCC 36316, which causes a severe disease known as Sclerotinia sclerotiorum in rapeseed plants. Bacillus lipopeptides had been widely used as biocontrol agents for plant diseases. In this study, we isolated 11 lipopeptide compounds from B. amyloliquefaciens Pc3 culture broth via reversed-phase high-performance liquid chromatography (RP-HPLC) and used matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) to identify these as iturin A (C14, C15, C16, C17), fengycin B (C14, C15, C16, C17), and surfactin (C14, C15, C16). We further found that the addition of exogenous alkanoic acids, including myristic acid, pentadecanoic acid, palmitic acid, heptadecanoic acid, octadecanoic acid, and nonadecanoic acid, to the bacterial growth media could promote lipopeptide production and enhance the antifungal activities of crude lipopeptide extracts from B. amyloliquefaciens Pc3. In addition, the transcriptional levels of three lipopeptide synthesis genes, ituD, fenA, and srfA-A, and two fatty acid metabolism-related genes, FabI, which encodes enoyl-ACP reductase, and FadB, which encodes enoyl-CoA hydratase, were found to be upregulated in cells grown with exogenous alkanoic acids. Among the six alkanoic acids tested, those with odd carbon chain lengths had a greater effect on lipopeptide production, antifungal activity, and target gene upregulation than those with even carbon chain lengths. These results provide a practical approach for the efficient production of lipopeptides in Bacillus amyloliquefaciens Pc3.

Fatty acid synthesis pathway provides lipid precursors for rhamnolipid biosynthesis in Burkholderia thailandensis E264

Rhamnolipid production was monitored for a period of 216 h using different substrates in Pseudomonas aeruginosa PAO1 and Burkholderia thailandensis E264 which showed comparable crude yields attained by both after 216 h. The crude yield for P. aeruginosa, however, was significantly higher at the early stages of fermentation (72 or 144 h). Additionally, P. aeruginosa produced rhamnolipid with odd and even carbon chain lipid moieties using odd carbon chain fatty acid substrates (up to 45.97 and 67.57%, respectively). In contrast, B. thailandensis produced rhamnolipid with predominantly even carbon chain lipid moieties (up to 99.26). These results indicate the use of the fatty acid synthesis (FAS II) pathway as the main source of lipid precursors in rhamnolipid biosynthesis by B. thailandensis. Isotope tracing using 0.25% stearic acid – d35 + 1% glycerol as carbon substrate showed a single pattern of deuterium incorporation: with predominantly less than 15 deuterium atoms incorporated into a single Di-C14-C14 rhamnolipid molecule. This further indicates that the FAS II pathway is the main source of the lipid precursor in rhamnolipid biosynthesis by B. thailandensis. The pathogenicity of these strains was also assessed, and results showed that B. thailandensis is significantly less pathogenic than P. aeruginosa with an LC50 at 24 h > 2500, approximately three logs higher than P. aeruginosa using the Galleria mellonella larva model.

Proposal of a Linear Retention Index System for Improving Identification Reliability of Triacylglycerol Profiles in Lipid Samples by Liquid Chromatography Methods.

The retention index system was proposed in 1958 by Kováts. It is based on the correlation between the retention time of the analytes and the ones of a series of reference standards, making retention data dependent on the chromatographic phenomenon only, viz., on the three-term interaction analyte-stationary phase-mobile phase. Particularly in GC, because the mobile phase has a negligible influence, the retention of the analytes depends almost entirely on the stationary phase and it is as independent as possible from operating conditions. This makes retention index databases usable in samples identification at both the intra- and interlaboratory levels. The scope of this research was to create a similar identification system in LC, where the identification of unknowns is still a challenge because of the unavailability of spectral databases related to the low reproducibility of mass spectra generated by means of the atmospheric pressure ionization technique normally interfaced to LC. Lipid compounds, specifically triacylglycerols, were selected as target analytes mainly due to their regular chromatographic LC profile under reversed phase conditions. The odd carbon chain number triacylglycerol series from trinonain to trinonadecanoin was chosen as the basis of the retention index scale and a database of 209 triacylglycerols was built. For this purpose an ultra high-performance LC method, able to maximize the baseline separation of triacylglycerols in different real-world samples (vegetable oils, fish, and milk samples) was developed.

Most favorable cumulenic structures in iron-capped linear carbon chains are short singlet odd-carbon dications: a theoretical view.

Iron-capped, linear-carbon-chain dications have been investigated at the M06L/DZP level of quantum chemistry in order to determine their structural and electronic properties, focusing on differences between chains containing odd and even numbers of carbon atoms. Such differences result from changes in the electronic states and the acetylenic or cumulenic nature of the carbon chain. Interestingly, the short even-carbon chains exhibit distinct properties, but upon chain lengthening undergo a transition to structures similar to those of odd-carbon chains, with a turning point around [FeC10Fe]2+. On the other hand, the less extensively investigated short odd-carbon chains, such as [FeC5Fe]2+, [FeC7Fe]2+ and [FeC9Fe]2+, due to synthetic difficulty, are predicted to exhibit more exceptional properties than the short even-carbon chains in every aspect, such as excellent back bonding as well as more cumulenic and more nearly linear structures. This theoretical study suggests that more experimental work should be considered on metal-capped, short linear odd-carbon chains as potential building blocks for novel electronic and optical materials.

Calorimetric investigation on three-ring chain ethylene-bridge liquid crystalline compounds with terminal odd carbon chain

The stabilities and the phase transition sequences of two ethylene-bridge fluorinated liquid crystals have been examined using the differential scanning calorimeter; and the repeatability and reliability for these phase transitions also have been verified. Furthermore, we report molar heat capacities of these two fluorinated liquid crystals measured using a Quantum Design physical properties measurement system with specific heat option within the temperature range from 1.9 to 300 K. The heat capacities of these two compounds increase with the temperature increasing, and no thermal anomalies have been found in the entire temperature region; and also the heat capacity values of 5-BB2B-F are larger than those of 3-BB2B-F due to the molecular weight difference even though they are homologous. The experimental data have been fitted to a function of T with a series of theoretical and empirical models for the proper temperature ranges. Thermodynamic function values \(C_{\text{p,m}}^{0} ,\Delta_{ 0}^{{\text{T}}} S_{\text{m}}^{\text{o}}\) and \(\Delta_{ 0}^{\text{T}} H_{\text{m}}^{\text{o}}\) at T = (0.5–300) K have been calculated based on these fitting results. The standard molar heat capacities, entropies and enthalpies of 3-BB2B-F and 5-BB2B-F at 298.15 K and 0.1 MPa have been determined to be \(C_{\text{p,m}}^{\text{o}}\) = (450.02 ± 4.50) J K−1 mol−1 and (478.08 ± 4.78) J K−1 mol−1, \(S_{\text{m}}^{\text{o}}\) = (443.91 ± 4.44) J K−1 mol−1 and (486.85 ± 4.87) J K−1 mol−1 and \(H_{\text{m}}^{\text{o}}\) = (66.47 ± 0.66) kJ mol−1 and (72.66 ± 0.73) kJ mol−1, respectively.

Dietary Cerebroside from Sea Cucumber (Stichopus japonicus): Absorption and Effects on Skin Barrier and Cecal Short-Chain Fatty Acids.

Sphingolipids from marine sources have attracted more attention recently because of their distinctive structures and expected functions. In this study, the content and components of cerebroside from sea cucumber Stichopus japonicus were analyzed. The absorption of cerebroside from S.japonicus was investigated with an in vivo lipid absorption assay. The result revealed that S.japonicus is a rich source of cerebroside that contained considerable amounts of odd carbon chain sphingoid bases. The cumulative recoveries of d17:1- and d19:2-containing cerebrosides were 0.31 ± 0.16 and 0.32 ± 0.10%, respectively, for 24 h after administration. To the best of the authors' knowledge, this is the first work that shows sphingolipids from a marine source could be absorbed in vivo and incorporated into ceramides. In addition, dietary supplementation with sea cucumber cerebroside to hairless mouse improved the skin barrier function and increased short-chain fatty acids in cecal contents, which have shown beneficial effects on the host.

Sugar and volatile fatty acids dynamic during anaerobic treatment of olive mill wastewater

ABSTRACTBiogas production has been the main route used to exploit olive mill wastewater (OMW), after pretreatment and/or in combination with other effluents, but more recently the production of chemicals and biopolymers by biotechnological routes has deserved increasing attention by the scientific community. The present paper aims to explore the potential of fresh OMW as a source of volatile fatty acids (VFAs) and biogas. The time profile of VFAs production and the corresponding sugar consumption was followed by high-performance liquid chromatography, in batch anaerobic assays. The experimental results have revealed the very high potential of the OMW for the production of VFAs, mainly due to the high sugar concentration in the effluent (37.8 g/L) and its complete conversion into VFAs, in a time period of 2–3 days. The most abundant VFAs were acetic (48–50%), n-butanoic (12–27%), iso-pentanoic (12–14%) and propanoic (5–13%). The ratio of VFA containing even and odd carbon chains increased with the reduction in the initial chemical oxygen demand concentration of the samples used in the experiments. The conversion of the VFAs to biogas was inhibited at concentrations of 3.5 g/L of VFAs.

Fatty acid profiling reveals a trophic link between mangrove leaf litter biofilms and the post-larvae of giant tiger shrimp Penaeus monodon

AEI Aquaculture Environment Interactions Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections AEI 6:1-10 (2014) - DOI: https://doi.org/10.3354/aei00117 FEATURE ARTICLEFatty acid profiling reveals a trophic link between mangrove leaf litter biofilms and the post-larvae of giant tiger shrimp Penaeus monodon Warima C. Gatune1,2,3,*, Ann Vanreusel1, Renison Ruwa2, Peter Bossier4, Marleen De Troch1 1Ghent University, Biology Department, Marine Biology, Campus Sterre, Krijgslaan 281-S8, 9000 Ghent, Belgium 2Kenya Marine and Fisheries Research Institute, PO Box 80100, 81651 Mombasa, Kenya 3Karatina University, School of Natural Resources and Environmental Studies, PO Box 1957-10101, Karatina, Kenya 4Ghent University, Faculty of Bioscience Engineering, Laboratory of Aquaculture and Artemia Reference Centre, Rozier 44, 9000 Ghent, Belgium *Corresponding author: kgatune@yahoo.com ABSTRACT: Shrimp ponds integrated with mangroves intercept leaf litter which may contribute to the bioenergetics of shrimps. Since fatty acids (FAs) determine the nutritive value of shrimp food, we analyzed and compared the FA profiles of post-larvae (PL) of Penaeus monodon fed with decomposing litter of Rhizophora mucronata, the associated biofilm, or a nutritionally optimized compound food. Three nutritionally important stages of decomposition (1, 5, and 10 wk) were tested. FA levels of PL at the start of the experiment were used as controls. As litter decomposed, saturated FAs decreased, whereas monounsaturated FAs (MUFAs) and polyunsaturated FAs (PUFAs) increased. PUFA concentrations were higher in biofilm than in the litter. PL fed with litter and biofilm food had higher MUFAs, arachidonic acid (ARA), and eicosapentaenoic acid (EPA) compared to PL fed with a compound food. However, PL fed with compound food had higher linoleic acid and docosahexaenoic acid (DHA). PL fed with 5 wk decomposed litter and its biofilm had a high concentration of bacterial odd carbon chain FAs. FAs in shrimp tissue reflected the FA profiles of the food sources in all treatments, with biofilm and compound food showing a better match. We conclude that (1) mangrove biofilm is a potential source of essential FAs to PL, especially providing ARA, EPA, and DHA; (2) biofilm on mangrove leaf litter may upgrade the nutritional value of PL for their consumers, including humans; and (3) efforts should be made to promote periphytic biofilms in integrated mangrove-shrimp culture practices. KEY WORDS: Biofilm · Fatty acid · Shrimp · Silvoculture · Kenya Full text in pdf format Information about this Feature Article NextCite this article as: Gatune WC, Vanreusel A, Ruwa R, Bossier P, De Troch M (2014) Fatty acid profiling reveals a trophic link between mangrove leaf litter biofilms and the post-larvae of giant tiger shrimp Penaeus monodon . Aquacult Environ Interact 6:1-10. https://doi.org/10.3354/aei00117Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in AEI Vol. 6, No. 1. Online publication date: November 11, 2014 Print ISSN: 1869-215X; Online ISSN: 1869-7534 Copyright © 2014 Inter-Research.

Growth kinetics, effect of carbon substrate in biosynthesis of mcl-PHA by Pseudomonas putida Bet001.

Growth associated biosynthesis of medium chain length poly-3-hydroxyalkanoates (mcl-PHA) in Pseudomonas putida Bet001 isolated from palm oil mill effluent was studied. Models with substrate inhibition terms described well the kinetics of its growth. Selected fatty acids (C8:0 to C18:1) and ammonium were used as carbon and nitrogen sources during growth and PHA biosynthesis, resulting in PHA accumulation of about 50 to 69% (w/w) and PHA yields ranging from 10.12 g L(-1) to 15.45 g L(-1), respectively. The monomer composition of the PHA ranges from C4 to C14, and was strongly influenced by the type of carbon substrate fed. Interestingly, an odd carbon chain length (C7) monomer was also detected when C18:1 was fed. Polymer showed melting temperature (T m) of 42.0 (± 0.2) °C, glass transition temperature (T g) of -1.0 (± 0.2) °C and endothermic melting enthalpy of fusion (ΔHf) of 110.3 (± 0.1) J g(-1). The molecular weight (M w) range of the polymer was relatively narrow between 55 to 77 kDa.

Odd–even dependence of rectifying behavior in carbon chains modified diphenyl–dimethyl molecule

Using density functional theory and non-equilibrium Green’s function formalism, we investigate the effects of asymmetric nonequi-length carbon chains on the electron transport properties of diphenyl–dimethyl molecule. The results show significant odd–even dependence: the rectification appears only in the hybrid nanostructure with odd carbon chain on one side and even carbon chain on the other side, while it is negligible in those with odd/even carbon chain on both sides. The mechanism for the odd–even dependence of rectification is analyzed by the bias-dependent transmission spectra, evolution of molecular orbital levels, their spatial distributions, and projected density of states with the applied bias.

Short-chain chlorinated paraffins (SCCPs) in surface soil from a background area in China: occurrence, distribution, and congener profiles

Short-chain chlorinated paraffins (SCCPs) are extremely complex technical mixtures of polychlorinated n-alkanes with carbon chain lengths from C10 to C13 and chlorine content between 49 and 70%. SCCPs are under consideration for inclusion in the Stockholm Convention on persistent organic pollutants. SCCPs have been used extensively in industrial production, but little is known about the pollution level in soil environment in China. In this study, levels and distribution of SCCPs in soil samples from Chongming Island were analyzed. Concentrations of total SCCPs in soil samples ranged from 0.42 to 420 ng g(-1), with a median of 9.6 ng g(-1). The ubiquitous occurrence of SCCPs in Chongming Island implied that long-range atmospheric transport and soil-air exchange may be the most important pathways for SCCP contamination in the background area. The localized SCCP contamination could be derived from an unidentified source. Hierarchical cluster analysis indicated that C13- and C11-congeners were predominant in most soils and C10- and C12-congeners dominated in the remaining soils. Cl7- and Cl8-congeners were on the average the most dominant chlorine congeners in nearly all soils. Principal component analysis suggested that the separation of even and odd carbon chain congeners occurred during long-range atmospheric transport and aging in soil in the study area.

Comparative study of serine-plasmalogens in human retina and optic nerve: identification of atypical species with odd carbon chains

The objective of this work was to detect and identify phosphatidylserine plasmalogen species in human ocular neurons represented by the retina and the optic nerve. Plasmalogens (vinyl-ether bearing phospholipids) are commonly found in the forms of phosphatidylcholine and phosphatidylethanolamine in numerous mammalian cell types, including the retina. Although their biological functions are unclear, the alteration of cellular plasmalogen content has been associated with several human disorders such as rhizomelic chondrodysplasia punctata Type 2 and primary open-angle glaucoma. By using liquid chromatography coupled to high-resolution and tandem mass spectrometry, we have identified for the first time several species of phosphatidylserine plasmalogens, including atypical forms having moieties with odd numbers of carbons and unsaturation in sn-2 position. Structural elucidation of the potential phosphatidylserine ether linked species was pursued by performing MS(3) experiments, and three fragments are proposed as marker ions to deduce which fatty acid is linked as ether or ester on the glycerol backbone. Interpretation of the fragmentation patterns based on this scheme enabled the assignment of structures to the m/z values, thereby identifying the phosphatidylserine plasmalogens.