Soil bio-functioning under <Emphasis Type="Italic">Acacia nilotica</Emphasis> var. <Emphasis Type="Italic">tomentosa</Emphasis> protected forest along the Senegal River

Acacia nilotica var. tomentosa trees from the Diarra protected forest located in the Senegal River valley were identified for the assessment of both biological nitrogen fixation, using the natural abundance method, and soil bio-functioning parameters (nodulation, root biomass, total microbial biomass, and potential N mineralization). The presence and the genetic diversity of indigenous rhizobia nodulating A. nilotica var. tomentosa was also investigated, taking into account distance from the trunk (0, 1, 2, and 3 m) and depth (0–25, 25–50, and 50–75 cm). Surprisingly, no nodules on the trees root systems were found, whereas under laboratory conditions the presence of indigenous rhizobia nodulating A. nilotica var. tomentosa was demonstrated in the analyzed soils (90% of the nodules harvested on the trapped plants were occupied by the same Inter-Genic Spacer (IGS) group, IGS1). There was no significant influence of trees and/or depth on total microbial biomass and potentials of nitrogen mineralization. Some assumptions were formulated on the possible combined effect of flooding, which usually occurs annually during 4–7 months, and the clayey soils in the Diara forests. Although a deeply natural nodulation of A. nilotica var. tomentosa trees by indigenous rhizobia is not excluded, but it still remains to be demonstrated.     

Reaction selectivity of <Emphasis Type="Italic">rhizomucor miehei</Emphasis> lipase as influenced by monoacylation of <Emphasis Type="Italic">sn</Emphasis>-glycerol

Reaction selectivities were determined in multicompetitive reactions mediated by Rhizomucor miehei (RM) lipase at water activity of 0.19 in hexane. Saturated FA (C4–C18 even chain) and oleic acid (C18∶1) were reacted with a single alcohol, glycerol, or α-or β-MAG containing C4, C10, C16, or C18∶1 individually as alcohol cosubstrate. Similar patterns of broad FA selectivity toward C8–C18 FA were generally observed for esterification into specific acylglycerol (AG) pools with the different α/β-CX-MAG cosubstrates. Exceptions were enrichment of C18 in the MAG pool with α-C16-MAG substrate, and a general suppression of C4/C6 FA reactivity and a specific discrimination toward >C8 FA incorporation into the TAG pool, both for reactions with α-C10- and α-C16-MAG. RM lipase selectivity toward MAG was in descending order: β-C18∶1-MAG>α/β-C4-MAG∼β-C10-MAG∼β-C16-MAG>α-C18∶1-MAG >α-C10-MAG∼α-C16-MAG. Selectivity in channeling CX of the original CX-MAG substrates into higher AG species was in descending order: α-C10-MAG∼α-C16-MAG>β-C10-MAGβ-C16-MAG>α-C18∶1-MAG>β-C18∶1-MAG∼ α/β-C4-MAG. Aside from their characteristic FA selectivity, Burkholderia cepacia (PS-30) and RM lipases behaved similarly in terms of MAG selectivity as well as a general conservation of FA selectivity throughout the sequential steps of TAG assembly from FA and glycerol for processes designed to yield specifically structured TAG.     

<Emphasis Type="Italic">trans</Emphasis> Fatty Acid Content of Canadian Margarines Prior to Mandatory <Emphasis Type="Italic">trans</Emphasis> Fat Labelling

Dietary trans fatty acids (TFA) are of major concern because of their adverse effects on blood lipid levels and coronary heart disease. In Canada, margarines were significant sources of TFA during the 1980s and 1990s. However, this is expected to change with increased public awareness over their adverse health effects and the introduction of new legislature to include TFA content on the Nutritional Facts table of food labels. In this study, the TFA content of the top-selling 29 Canadian margarines, which represented 96.3% of the market share, was determined by capillary gas-liquid chromatography in order to assess the influence of regulatory development during the 3-year transition period between the announcement of new food labelling regulations in Canada that require mandatory declaration of the trans fat content in most pre-packaged foods in January 2003 and its enforcement on 12 December 2005. The 29 margarines included 15 tub margarines made from non-hydrogenated vegetable oils (NHVO-tub margarines), 11 tub margarines made from partially hydrogenated vegetable oils (PHVO-tub margarines) and three print margarines, which were also made from partially hydrogenated vegetable oils (PHVO-print margarines). The 15 NHVO tub-margarines accounted for 71% of the total margarine market share and generally contained less than 2% TFA (mean value 0.9 ± 0.3% of total fatty acids). The mean total TFA contents of PHVO-tub margarines and PHVO-print margarines, were 20.0 ± 4.5% and 39.6 ± 3.5%, and their market shares were 19.3 and 6.0%, respectively. Although during the last 10 years, increasing number of soft tub margarines that contained very little trans fats have been made available in Canada, the PHVO-tub- and -print margarines still contain high levels of trans fats similar to those margarines that were sold in the 1990s. The market share data suggest that the margarines prepared using NHVO and containing almost no TFA were preferred by Canadians over those margarines prepared using PHVO, even before the mandatory declaration of TFA content came into effect on 12 December 2005.     

Temperature programmed desorption of <Emphasis Type="Italic">n</Emphasis>-hexane and <Emphasis Type="Italic">n</Emphasis>-heptane from MFI and FAU zeolites

TPD studies of n-hexane and n-heptane from NaX, Y and ZSM-5 (Na⁺ or H⁺ exchanged) in the experimental system with a TCD detector were performed, using pure He or He/n-alkane mixture as a carrier gas. The TPD profiles with one desorption peak for Y and two peaks for ZSM-5, measured using He/hydrocarbon mixture, were similar to the previously reported equilibrated thermodesorption results. TPD profiles were accurately fitted with a model based on the equilibrium control of the desorption and the adsorption functions derived from the Langmuir or dual site Langmuir isotherms.     

Synthesis and Antioxidancy of Some <Emphasis Type="Italic">n</Emphasis>-Alkyl, <Emphasis Type="Italic">t</Emphasis>-Alkyl,Homologous and Isomeric Lipidic Alkylthiobisphenols

To study the relationship between structure and properties of members of the lipidic thiobis phenol series, as extreme pressure additives in lubricants, a series of homologous compounds has been synthesised by the reaction of alkylphenols with sulphur dichloride. The isomeric n-nonylphenols have been reacted to form the C9 isomeric 2,2′-and 4,4′-thiobisphenols. Longer alkyl side-chains resulted mainly in the formation of 4,4′-thiobisphenols and some of the 2,2′ isomer. With short alkyl, particularly t-alkyl side-chains, steric hindrance resulted in the 2,2′-compound. Additive studies have indicated that the longer chain 4,4′ compounds possessed antioxidant properties comparable and superior to former commercial branched chain 2,2′ compounds produced from petrochemical intermediates. Lipidic alkylthiobisphenols: Long chain phenols, Part 40b (Part 40a, ref 6).     

Electrochemical oxidation of <Emphasis Type="Italic">p</Emphasis>-sulfonated calix[8]arene

The water-soluble p-sulfonated sodium salt of calix[8]arene (III) was synthesized. The product was characterized by FT-IR, NMR and UV–Vis spectra.Then the electrochemical behaviors of p-sulfonated sodium salt of calix[8]arene in NaAc+HAc (pH = 4) buffer solution was studied. In aqueous solution, p-sulfonated calix[8]arene can be oxidized when the potential is more than 0.7 V vs SCE. It was confirmed that the reaction was a two-electron irreversible electrochemical reaction. The transfer coefficient, α, was measured as 0.7. At 25°, the diffusion coefficient of p-sulfonated calix[8]arene was determined as 8.6 × 10⁻⁷ cm² s⁻¹. The diffusion activation energy of p-sulfonated calix[8]arene was 18.9 kJ mol⁻¹ at pH = 4.     

Production of 14-Oxo-<Emphasis Type="Italic">cis</Emphasis>-11-eicosenoic Acid from Lesquerolic Acid by <Emphasis Type="Italic">Sphingobacterium multivorum</Emphasis> NRRL B-23212

The objective of this study was to explore the extent of microbial conversion of lesquerolic acid (14-hydroxy-cis-11-eicosenoic acid; LQA) by whole cell catalysis and to identify the newly converted products. Among compost isolates including NRRL strains B-23212 (Sphingobacterium multivorum), B-23213 (Acinetobacter sp.), B-23257 (Enterobacter cloacae B), B-23259 (Escherichia sp.) and B-23260 (Pseudomonas aeruginosa) the S. multivorum strain was the only microorganism that converted LQA to produce a new product identified as 14-oxo-cis-11-eicosenoic acid by GC-MS and NMR analyses. The conversion yield was 47.4% in 48 h at 200 rpm and 28°C in small shake flask experiments. In comparison, both Acinetobacter and Pseudomonas strains failed to convert LQA to major new products but used LQA apparently as an energy source during fermentation. For structural analysis, 6.88 g of 14-oxo-cis-11-eicosenoic acid was produced from converting 11 g LQA (a 62% yield) in 72 h at 200 rpm and 28 °C in Fernbach flasks using 18-h-old NRRL B-23212 cultures and an improved medium that also contained EDTA and glycerol in lieu of glucose as carbon source. NRRL B-23212 was further identified by 16S rRNA gene sequence analysis as a unique strain of S. multivorum. Therefore, S. multivorum NRRL B-23212 possesses an enzymatic activity presumably a secondary alcohol dehydrogenase for converting LQA to produce 14-oxo-cis-11-eicosenoic acid, a first report that demonstrates the functional modification of LQA by whole cell catalysis.     

Adsorption of Bovine Serum Albumine Onto Poly (<Emphasis Type="Italic">N</Emphasis>-<Emphasis Type="Italic">t</Emphasis>-Butylacrylamide-co-Acrylamide/Maleic Acid) Hydrogels

In the present study, a series of ionic poly(N-t-butylacrylamide-co-acrylamide) [P(NTBA-co-AAm)] hydrogels were synthesized by free-radical crosslinking copolymerization of N-t-butylacrylamide (NTBA) and acrylamide (AAm) monomers in fixed amount, but changing amount of maleic acid (MA) comonomer in methanol using N,N-methylene-bis-acrylamide (BAAm) as the crosslinker, ammonium persulfate (APS) as the initiator, and N,N,N′,N′-tetramethylethylenediamine (TEMED) as the activator. The swelling behavior of these hydrogels was analyzed in buffer solutions at various pHs. The prepared hydrogels also were investigated swelling-deswelling transition in water depending on the temperature. For the bovine serum albumin (BSA) adsorption, the effect of pH, temperature, initial protein concentration and adsorption rate were investigated. Maximum BSA adsorption was observed at pH 5.0 which is close to the isoelectric pH of BSA (pH 4.8). The highest adsorption rate was achieved in about 12 h. and also, maximum BSA adsorption was found at +5°C.     

Electrochemical behavior of a new <Emphasis Type="Italic">s</Emphasis>-triazine-based dendrimer

The electrochemical behavior of a new G-2-s-triazine-based dendrimer, 2,4,6-tris-{4-{4,6-bis-{4-{4,6-bis-[(1S,2S)-1,3-dihydroxy-1-(4-nitrophenyl)-prop-2-ylamino]-s-triazin-2-yl}-piperazin-1-yl}-s-triazin-2-yl}-piperazin-1-yl}-s-triazine, (I), was studied in dimethylsulfoxide solution by cyclic voltammetry, on platinum and graphite electrodes. The electrochemical properties of I were compared with that of one of its precursor, N-{4,6-bis{4-{4,6-bis[(1S,2S)-1,3-dihydroxy-1-(4-nitrophenyl)-prop-2-ylamino]-s-triazin-2-yl}-piperazin-1-yl}-triazin-2-yl}-piperazine), (II), together with that of the starting material, (1S,2S)-2-amino-1-(4-nitrophenyl)-propane-1,3-diol (“p-nitrophenylserinol”), (III).     

Inhibition of melanogenesis and melanin transportation by <Emphasis Type="Italic">Gynostemma pentaphyllum</Emphasis>

The extract of Gynostemma pentaphyllum was tested to control the melanogenesis in B16 melanoma. Cytotoxic effect by the extract was observed when the dose concentration was higher than 2 mg/L. Most of the inhibitory effect was obtained by the reduced accumulation of extra-cellular melanin. When the extract was dosed as 2 mg/L, the extra-cellular melanin produced was only 24% of the control. Proteome analysis with 2-D PAGE showed that various proteins involved in melanogenesis were down-regulated by Gynostemma pentaphyllum. In addition to other proteins related to the intra-cellular melanogenesis, Rab-27b and Rab-38 could explain the remarkable decrease in extra-cellular melanin accumulation by reduced melanin transfer to keratinocyte.     

Condensation enthalpies of <Emphasis Type="Italic">n</Emphasis>-hexane in micelle-templated mesoporous silicas

The isosteric enthalpies of adsorption of n-hexane on ordered mesoporous silica of pore diameter between 3 and 10 nm have been measured. The heat of capillary condensation increases when mesopores are smaller. Capillary condensation of n-hexane in 3 nm mesopores is 20% more exothermic than the condensation on a flat liquid surface. The results are in good agreement with a model which takes into account the energetic contribution of the interface between the adsorbed layer and the vapour phase.     

Fatty Acid Composition of Selected Fresh Water Gammarids (<Emphasis Type="Italic">Amphipoda</Emphasis>, <Emphasis Type="Italic">Crustacea</Emphasis>): A Potentially Innovative Source of Omega-3 LC PUFA

The aim of this work was to estimate the content and composition of n-3 long chain polyunsaturated fatty acids in selected gammarid species commonly occurring in fresh waters of Central and Western Europe. Five gammarid species were investigated, two native, one old invader consider as semi-native and two Ponto-Caspian species invading the area in the last decade. Lipid content of evaluated species ranged from 75 to 130 g kg⁻¹ of dry weight. Significant amounts of n-3 LC PUFA were found in the lipid fraction of analyzed gammarids 11–23% of total fatty acids, especially in the Ponto-Caspian species. The main n-3 fatty acid was EPA—up to 16% of total fatty acids. The ratio of n-6 to n-3 was nutritionally desirable, especially in the case of the Ponto-Caspian species. The results obtained and growing biomass of gammarids observed in fresh waters of Central and Western Europe, as well as the rapid depletion of sea fish communities leads us to the idea that these gammarids might be considered as a innovative source of n-3 LC PUFA for nutritional, pharmaceutical and animal feeding purposes.     

Electro-oxidation of rutin in the presence of <Emphasis Type="Italic">p</Emphasis>-toluenesulfinic acid

We report the electrochemical oxidation of rutin in acetonitrile-sodium phosphate (4:1 (v/v); pH 2.0) in the presence of p-toluenesulfinic acid. Cyclic voltammetry and controlled potential electrolysis were used to study rutin electro-oxidation and to prepare the sulfone derivatives. Chromatographic methods were employed to separate the products and IR, ¹H NMR, ¹³C NMR, MS and microanalysis to their characterization. Data from cyclic voltammetry allow the identification of three rutin oxidation processes in the presence of p-toluenesulfinic acid (E _p^I = 0.56 V, E _p^II = 0.81 V and E _p^III = 1.32 V). Only the electrode process around peak I was exhaustively studied. The first oxidation step leads to the formation of the corresponding o-quinone, which participates in a Michael addition reaction with the p-toluenesulfinic acid, forming the 6′(4-methylphenylsulfonyl)rutin and 6′(4-methylphenylsulfonyl)quercetin as majority products.     

Full-Press Oil Extraction of <Emphasis Type="Italic">Cuphea</Emphasis> (PSR23) Seeds

Cuphea PSR23, a semi-domesticated, high-capric-acid hybrid from Cuphea viscosissima × Cuphea lanceolata, is being developed as a potential commercial alternative source of medium-chain fatty acids. The present study evaluated the effects of initial seed moisture and final moisture contents of cooked flaked seed on Cuphea’s pressing characteristics and the quality of the extracted oil. Seeds with 9 and 12% initial moisture contents (MC) were flaked and cooked at different residence times to produce cooked seeds with MC of 3.0–5.5%. Cooked seeds were pressed using a laboratory screw press. Eighty and 84% oil were extracted from cooked seeds with 5.5 and 3.0% MC, respectively. The seeds with 9% initial MC exhibited lower pressing load increase (9.1 per 1% decrease in MC) than the seeds with 12% initial MC (16.4 per 1% decrease in MC). The pressing rate decreased by 3% as the cooked flaked seed MC decreased. The amount of foots in the oil increased from 3 to 6.6% and chlorophyll content increased from 200 to 260 ppm as cooked flaked seed MC decreased from 5.5 to 3.0%. FFA contents were 2.5% for all treatments MC studied. The phosphatide content increased as the cooked flaked seed MC decreased but the amounts were still within the levels of water-degummed oil. This paper may contain brand names that are necessary to report factually on available data; however, the USDA neither guarantees nor warrants the standard of the product, and the use of the name by USDA implies no approval of the product to the exclusion of others that may also be suitable.     

Application of poly(<Emphasis Type="Italic">o</Emphasis>-phenylenediamine) in rechargeable cells

The electrochemical synthesis of poly(o -phenylenediamine) (PoPD) from an aqueous medium was suitably modified by controlling the switching potential to enhance the growth of the polymer. The charge–discharge data for the cell Zn/1 M ZnSO₄ (pH 4)/PoPD are presented. The polymer was modified by incorporating Pt microparticles into its matrix during electropolymerization. The PoPD-Pt composite electrode was also characterized as a cathode active material in aqueous cells.     

Highly selective and sensitive Th<Superscript>4+</Superscript>-PVC-based membrane sensor based on 2-(diphenylphosphorothioyl)-<Emphasis Type="Italic">N</Emphasis>′,<Emphasis Type="Italic">N</Emphasis>′-diphenylacetamide

A Th⁴⁺ ion-selective membrane sensor was fabricated from poly (vinyl chloride) (PVC) matrix membrane containing 2-(diphenylphosphorothioyl)-N′,N′-diphenyl acetamide (DPTD) as a neutral carrier, potassium tetrakis (p-chlorophenyl) borate (KTpClPB) as anionic excluder and o-nitrophenyloctyl ether (NPOE) as a plasticizing solvent mediator. The effects of the membrane composition, pH and additive anionic influence on the response properties were investigated. The sensor, comprising 30% PVC, 63% solvent mediator, 4% ionophore and 3% anionic additive demonstrates the best potentiometric response characteristics. It displays Nernstian behavior (15.2 ± 0.5 mV per decade) over the concentration range 1.0 × 10⁻²–1.0 × 10⁻⁶ M. The detection limit of the electrode is 6.3 × 10⁻⁷ M (∼140 ng/ml). The response time of the electrode is 30 s .The sensor can be used in the pH range 3.0–9.0 for about 6 weeks. The membrane sensor was used as an indicator electrode in the potentiometric titration of Th⁴⁺ ions with EDTA. It was successfully applied to the determination of thorium ions in binary mixture.     

Electrochemical oxidation of an acid dye by active chlorine generated using Ti/Sn<Subscript>(1−<Emphasis Type="Italic">x</Emphasis>)</Subscript>Ir<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>O<Subscript>2</Subscript> electrodes

The generation of active chlorine on Ti/Sn_(1−x)Ir _x O₂ anodes, with different compositions of Ir (x = 0.01, 0.05, 0.10 and 0.30 ), was investigated by controlled current density electrolysis. Using a low concentration of chloride ions (0.05 mol L⁻¹) and a low current density (5 mA cm⁻²) it was possible to produce up to 60 mg L⁻¹ of active chlorine on a Ti/Sn_0.99Ir_0.01O₂ anode. The feasibility of the discoloration of a textile acid azo dye, acid red 29 dye (C.I. 16570), was also investigated with in situ electrogenerated active chlorine on Ti/Sn_(1−x)Ir _x O₂ anodes. The best conditions for 100% discoloration and maximum degradation (70% TOC reduction) were found to be: NaCl pH 4, 25 mA cm⁻² and 6 h of electrolysis. It is suggested that active chlorine generation and/or powerful oxidants such as chlorine radicals and hydroxyl radicals are responsible for promoting faster dye degradation. Rate constants calculated from color decay versus time reveal a zero order reaction at dye concentrations up to 1.0 × 10⁻⁴ mol L⁻¹. Effects of other electrolytes, dye concentration and applied density currents also have been investigated and are discussed.     

Enhanced biosurfactant production by <Emphasis Type="Italic">Corynebacterium alkanolyticum</Emphasis> ATCC 21511 using self-cycling fermentation

Enhanced biosurfactant production by Corynebacterium alkanolyticum ATCC 21511 was accomplished in a self-cycling fermenter (SCF) on a hexadecane substrate. The phospholipid biosurfactant produced during each cycle could be monitored rapidly using fluorescence spectroscopy. By optimizing the cycling pattern of the SCF, significantly better yields of biosurfactant were obtained than previously reported for this microorganism. It was also possible to virtually eliminate the hydrocarbon residue in the product. Harvest concentrations of 1.9 g L⁻¹ were obtained by using a two-stage fermentation. The first step was the growth of C. alkanolyticum in an SCF to yield a harvest of synchronous cells. These cells were transferred to a second vessel for the production stage. The concentration of biosurfactant could be further increased to 2.7 g L⁻¹ by the addition of more hexadecane at the beginning of the second stage.     

Medium optimization of <Emphasis Type="Italic">Rhodococcus erythropolis</Emphasis> LSSE8-1 by Taguchi methodology for petroleum biodesulfurization

High production of Rhodoccus erythropolis LSSE8-1 and its application for the treatment of diesel oils was investigated. Culture conditions were optimized by Taguchi orthogonal array experimental design methodology. High cell density cultivation of biocatalyst with pH control and fed-batch feeding strategies was further validated in a fermentor with the optimal factors. Cell concentration of 23.9 g dry cells/L was obtained after 96 h cultivation. The resting cells and direct fermentation suspension were applied for deep desulfurization of hydrodesulfurized diesel oils. It was observed that the sulfur content of the diesel decreased from 248 to 51 μg/g by two consecutive biodesulfurizations. It implied that the biodesulfurization process can be simplified by directly mixing cell cultivation suspension with diesel oil. The biocatalyst developed with the Taguchi method has the potential to be applied to produce ultra-low-sulfur petroleum oils.     

<Emphasis Type="Italic">In situ</Emphasis> analysis of high temperature characteristics of prismatic polymer lithium - ion batteries

A systematic approach to understanding the safety fundamentals of Li-ion batteries was undertaken. Firstly, we present thermal characterization experiments of charged prismatic polymer lithium-ion batteries (PLBs). These cells, at different state of charge (SOC), were tested inside an accelerated rate calorimeter (ARC) to determine the onset-of-thermal runaway (OTR) temperatures. In addition, the thermally activated components of these cells were followed by monitoring both the impedance (at 1 kHz) and the open circuit voltage (OCV) as a function of temperature. An increase in the impedance was observed at around 133 °C corresponding to the polyethylene separator shutdown. Secondly, an original in situac impedance measurement was performed over a wide range of frequencies instead of 1 kHz when the battery was heated from ambient to 130 °C. Resulting impedance spectra were modeled using an appropriate equivalent circuit. It is concluded that the high frequency and the low frequency semicircles observed in the impedance spectra are due to processes occurring the anode/electrolyte and cathode/electrolyte interfaces, respectively. The activation energy E _a was found in the ranges of 0.4–0.6 and 0.36–0.53 eV, for cathode and anode processes, respectively. In addition, it is assumed that change in the electrolyte composition is the main factor responsible for the rise in the cell impedance at high temperatures.