n-Butanol

Project ID

1542

Category

IRIS

Added on

Dec. 14, 2010, 3:50 p.m.

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Journal Article

Abstract  Earlier studies had indicated that beta-amino butyric acid (BABA) treatment of pearl millet seeds influenced seedling vigor and protected seedlings from downy mildew disease caused by the oomycetous biotrophic fungus Sclerospora graminicola. Application of 50 mM BABA reduced disease severity and offered protection against S. graminicola of similar to 74%. The protection induced was durable and operative during the vegetative and reproductive growth periods of the crop. In the present study an attempt was made to understand the biochemical basis for this protection. A close association was found between BABA-induced protection and increased accumulation of defence-related proteins like phenylalanine ammonia lyase, peroxidase, beta-1,3-glucanase and cell wall hydroxyproline-rich glycoproteins (HRGP). Isoelectric focusing of beta-1,3-glucanases indicated the presence of several isoforms, of which isoforms of pI 9.6 and 8.8 were markedly increased in BABA-treated seedlings upon S. graminicola infection. Increased accumulation of hydroxyproline-rich glycoproteins was also observed at 9 h after inoculation in these samples. Western blots with MAC 265, a monoclonal antibody against pea HRGP identified a 17-kDa HRGP molecule that significantly increased in concentration in BABA- treated pearl millet seedlings as a response to S. graminicola infection. The postinfectional protection offered by BABA involved induction of defence responses which were comparable to the highly resistant cultivar.

Journal Article

Abstract  INTRODUCTION: Non-volatile oleoresins from neotropical Burseraceae are traditionally used for craft, technological and medicinal purposes. The crude resin is usually sold in popular markets of the forest communities. Adding value to this rainforest raw material requires establishing its composition.

OBJECTIVE: To analyse the resin composition from different Burseraceae species and establish a minimally reproducible profile by gas chromatography, in order to parameterise its quality control.

METHODOLOGY: Crude oleoresin samples of 10 Protium and Trattinnickia species and a commercial blend were subjected to hydrodistillation to remove volatile compounds. The chloroform-soluble residues were methylated, analysed by GC-FID (flame ionisation detection), and individual components were identified by analysing their mass fragmentation pattern in GC-MS and comparison with data from the literature. The blend solubility was assayed in 30 non-chlorinated solvents at three different proportions.

RESULTS: The resins consisted exclusively of triterpenes, showing a common predominance of four major compounds in all the samples, corresponding to α-amyrin, β-amyrin, α-amyrenone and β-amyrenone. This profile was complemented with minor amounts of the tetracyclic β-elemolic and α-elemolic acids, maniladiol, brein and other oxidised trace compounds. The better solvents for the resin were those chemically bearing more than four carbon atoms, as n-butyl acetate, 2-ethoxyethanol and isopropanol. The crude resin blend sold contained around 10% of insoluble material that was constituted by up to 70% inorganic residues mixed with humic acid derivatives, as attested by ash analysis and IR spectroscopy, respectively.

CONCLUSION: The experimental results, complemented by a general inspection of the literature, demonstrated a systematically reproducible triterpene profile in Protium and Trattinnickia species.

DOI
Journal Article

Abstract  Herein we report on the development of a novel and efficient approach to the restriction of the conformational mobility of calix[6]arenes. The method involves the addition of tertiary alcohols to calix[6]arenes with one, three and six cyanomethoxy groups attached to the lower rim under modified Ritter reaction conditions. Alkylation of monocyanomethoxy-p-tertbutylcalix[6]arene (1) and 37,39,41-trimethoxy-38,40,42- tricyanomethoxy-p-tert-butylcalix[6]arene (2) with 3-R-1-adamantanols (R = H, CH2COOH) in trifluoroacetic acid afforded the corresponding mono- and triamides with conelike conformations, The partial alkylation of hexanitrile derivatives showed unexpected regioselectivity. Addition of 1-adamantanol or tert-butyl alcohol to hexacyanomethoxy-p-X-calix[6]arenes 3a-c (X = tert-butyl, 1-adamantyl, 3-methoxycarbonylmethyl-1-adamantyl) gave 37,40-dinitrile-38,39,41,42-tetraamides as the major products. These tetraamides are conformationally restricted in solution over a wide range of temperatures and adopt a flattened 1,2,3-alternate conformation, as shown by 2D and variable-temperature NMR experiments. ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006).

WoS
Journal Article

Abstract  The U.S. Renewable Fuel Standard has made it a requirement to increase the production of ethanol and advanced biofuels to 36 billion gallons by 2022. Ethanol will be capped at 15 billion gallons, which leaves 21 billion gallons to come from other sources, such as butanol. Butanol has a higher energy density and lower affinity for water than ethanol. Moreover, alcohol fueled engines in general have been shown to positively affect engine-out emissions of oxides of nitrogen and carbon monoxide compared to their gasoline fueled counterparts. In light of these developments the variety and blend levels of oxygenated constituents is likely to increase in the foreseeable future.

The effect on engine-out emissions for total hydrocarbons (THC) is less clear due to the relative insensitivity of the flame ionization detector (FID) toward alcohols and aldehydes. It is well documented that hydrocarbon (HC) measurement using a conventional FID in presence of oxygenates in the engine exhaust stream can lead to a misinterpretation of HC emissions trends for alcohol fuel blends. Characterization of the exhaust stream for all expected hydrocarbon constituents is required to accurately determine the actual concentration of unburned fuel components in the exhaust. In addition to a conventional exhaust emissions bench, this characterization requires supplementary instrumentation capable of hydrocarbon speciation and response factor independent quantification. Although required for certification testing, this sort of instrumentation is not yet widely available in engine development facilities. Therefore an attempt is made to empirically determine an oxygenate fuel, FID correction factor. Exhaust emissions of an engine fueled with several blends of gasoline and ethanol, n-Butanol and iso-Butanol were characterized using both a conventional FID and an FTIR. Based on these results, a response factor predicting the actual hydrocarbon emissions, based solely on FID results as a function of alcohol type and content, is presented. Finally the correlation derived from data presented in this study is compared to equations and results found in the literature.

Journal Article

Abstract  A novel method was evaluated for preparation of hydrophobic drugs cyclodextrin (CD) complex in this study. To obtain sterilized drug-CD complex lyophilized powder for injection or other purpose, the CD solution in water and the hydrophobic drug in tertiary butyl alcohol (TBA) were mixed in a suitable volume ratio, filtered through 0.22 mu m millpores, and subsequently freeze-dried. A high drug concentration was obtained in the co-solvent due to the good solvency of TBA, which is miscible with water in any proportion, for hydrophobic drugs. Moreover, TBA could be removed rapidly and completely by freeze-drying because of its high vapor pressure and high melting point. The chemical stability of some labile active compounds was also improved in TBA-water co-solvent. Based on the data from differential scanning calormetry (DSC) and X-ray diffractometry (XRD), drug was amorphous in freeze-dried complex. The fourier transform infrared spectra indicated drug-CD interaction was present in drug-CD complex. An enhanced dissolution rate was also obtained in drug-CD complex. These results proved drug-CD complex had been formed after this technique. Thus, this report provided a simple, efficient, and economic technique for preparation of hydrophobic drugs CD complex, which may be useful practically in modifying hydrophobic drugs physicochemical properties and improving their absorption and pharmacodynamics.

Journal Article

Abstract  Nutty flavor in Cheddar cheese is desirable, and recent research demonstrated that 2- and 3-methyl butanal and 2-methyl propanal were primary sources of nutty flavors in Cheddar. Because malty strains of Lac-tococcus lactis (formerly Streptococcus lactis var. malti-genes) are characterized by the efficient production of these and other Strecker aldehydes during growth, this study investigated the influence of a malty L. lactis adjunct culture on nutty flavor development in Cheddar cheese. Cheeses made with different adjunct levels (0, 10(4) cfu/mL, and 10(5) cfu/mL) were ripened at 5 or 13 degrees C and analyzed after 1 wk, 4 mo, and 8 mo by a combination of instrumental and sensory methods to characterize nutty flavor development. Cheeses ripened at 13 degrees C developed aged flavors (brothy, sulfur, and nutty flavors) more rapidly than cheeses held at 5 degrees C. Additionally, cheeses made with the adjunct culture showed more rapid and more intense nutty flavor development than control cheeses. Cheeses that had higher intensities of nutty flavors also had a higher concentration of 2/3-methyl butanal and 2-methyl propanal compared with control cheeses, which again confirmed that these compounds are a source of nutty flavor in Cheddar cheese. Results from this study provide a simple methodology for cheese manufacturers to obtain consistent nutty flavor in Cheddar cheese.

Journal Article

Abstract  Since advances in the ABE (acetone-butanol-ethanol) fermentation process in recent Years have led to significant increases in its productivity and yields, the production of butanol and its use in motor vehicles have become an option worth evaluating. This study estimates the potential life-cycle energy and emission effects associated with using bio-butanol as a transportation fuel. It employs a well-to-wheels (WTW) analysis tool: the Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) model. The estimates of life-cycle energy use and greenhouse gas (GHG) emissions are based on an Aspen Plus(R) simulation for a corn-to-butanol production process. which describes grain processing, fermentation, and product separation. Bio-butanol-related WTW activities include corn farming, corn transportation, butanol production, butanol transportation, and vehicle operation. hi this study, we also analyzed the bio-acetone that is coproduced with bio-butanol as an alternative to petroleum-based acetone. We then compared the results for bio-butanol with those of conventional gasoline. Our study shows that driving vehicles fueled with corn-based butanol produced by the current ABE fermentation process could result in substantial fossil energy savings (39%-56%) and avoid large percentage of the GHG emission burden, Yielding a 32%-48% reduction relative to using conventional gasoline. On energy basis, a bushel of corn produces less liquid fuel from the ABE process than that from the corn ethanol dry mill process. The coproduction of a significant portion of acetone from the current ABE fermentation presents a challenge. A market analysis of acetone, as well as research and development on robust alternative technologies and processes that minimize acetone while increase the butanol yield. should be conducted.

DOI
Journal Article

Abstract  A novel and highly practical one-pot synthesis of indigo from indole via 3-position selective oxidation and dimerization of the indole framework was developed. Using 0.1 mol % of molybdenum complex and 2.2 equivalents of cumene hydroperoxide in tert-butyl alcohol, the reaction was complete in 7 h and pure indigo was obtained in 81% yield as a deep-blue solid just by filtration. The described one-step method renders the pure indigo readily available on a large scale using only inexpensive raw materials.

DOI
Journal Article

Abstract  The queens of many social insects produce pheromones that influence the behaviour and physiology of colony members. Pheromones produced by queens have long been considered as the prime factor inhibiting the differentiation of new reproductive individuals. A volatile pheromone consisting of a blend of n-butyl-n-butyrate and 2-methyl-1- butanol comprises a queen pheromone that inhibits the differentiation of female neotenic reproductives (secondary queens) of a termite Reticulitermes speratus. 2-Methyl-1-butanol is the first chiral molecule to be identified as a primer pheromone in social insects, which presents the intriguing question of whether enantiomeric composition plays a role in caste regulation. In the present study, we report that the (R)- and (S)-enantiomers and the racemic mixture of 2- methyl-1-butanol show significant inhibitory effects on the differentiation of new female neotenics in combination with n-butyl-n-butyrate, whereas no significant difference in inhibitory activity is observed among them. These results suggests that termites recognize 2-methyl-1- butanol as a queen signal but they do not distinguish between the stereostructures of the enantiomers.

Journal Article

Abstract  An investigation of the basic factors which govern the microemulsion EKC (MEEKC) and MEKC for the separation of four benzoylurea (BU) insecticides and their four analogs was carried out. In MEEKC, the separation of eight BU compounds was optimized by changing the microemulsion composition, such as concentration of SDS, octane, n-butanol, and isopropanol percentages, as well as capillary temperature. Separation optimization was also carried out for MEKC, showing that ACN and a high level of another additive gamma-CD were needed to achieve effective separation of these analytes. Although separation with baseline resolution was achieved by either MEEKC or MEKC methods, the separation selectivity resulting from the proposed MEEKC method was completely different from that of MEKC. In addition, analytical time in MEEKC was longer than that in MEKC, but in view of theoretical plate numbers, detection limits, and reproducibility, both methods were effective for the analysis of BU insecticides and their analogs.

WoS
Journal Article

Abstract  For inkjet printing, pigment inks are suitable for all kinds of fibre, the printing procedure is simple without both pretreatment and after-treatment. In the future, the research and development of pigment ink will be the main trend of the inkjet printing technology. In this paper, the influence of polyhydric alcohol, surfactant, de foaming agent on ink performance, such as viscosity, surface tension and so on, was analyzed. The compatibility of polyhydric alcohols such as 1, 3-propanediol, diethylene glycol, 1, 6-hexylene glycol, glycerine with pigment ink has been researched, and effect of the amount of polyhydric alcohols on the viscosity and surface tension of ink was discussed. The function of surfactants OP-7,OP-10 and OP-15 in ink has been analyzed, the results show that surfactant OP-7 and OP-10 could decrease the surface tension of inks below 30mN/m when the amount used about 1.0% or lower by weight. The efficiency of reducing surface tension falls down in the sequence of the surfactants OP-7, OP-10 and OP-15. The effect of the amount of surfactant on the viscosity was not very significant. The defoaming effect of n-butyl alcohol on pigment ink has also researched in this paper.

Journal Article

Abstract  With the incessant fluctuations in oil prices and increasing stress from environmental pollution, renewed attention is being paid to the microbial production of biofuels from renewable sources. As a gasoline substitute, butanol has advantages over traditional fuel ethanol in terms of energy density and hygroscopicity. A variety of cheap substrates have been successfully applied in the production of biobutanol, highlighting the commercial potential of biobutanol development. In this review, in order to better understand the process of acetone-butanol-ethanol production, traditional clostridia fermentation is discussed. Sporulation is probably induced by solvent formation, and the molecular mechanism leading to the initiation of sporulation and solventogenesis is also investigated. Different strategies are employed in the metabolic engineering of clostridia that aim to enhancing solvent production, improve selectivity for butanol production, and increase the tolerance of clostridia to solvents. However, it will be hard to make breakthroughs in the metabolic engineering of clostridia for butanol production without gaining a deeper understanding of the genetic background of clostridia and developing more efficient genetic tools for clostridia. Therefore, increasing attention has been paid to the metabolic engineering of E. coli for butanol production. The importation and expression of a non-clostridial butanol-producing pathway in E. coli is probably the most promising strategy for butanol biosynthesis. Due to the lower butanol titers in the fermentation broth, simultaneous fermentation and product removal techniques have been developed to reduce the cost of butanol recovery. Gas stripping is the best technique for butanol recovery found so far.

Journal Article

Abstract  Genetic evidence suggests that indole-3-butyric acid (IBA) is converted to the active auxin indole-3-acetic acid (IAA) by removal of two side-chain methylene units in a process similar to fatty acid beta-oxidation. Previous studies implicate peroxisomes as the site of IBA metabolism, although the enzymes that act in this process are still being identified. Here, we describe two IBA-response mutants, ibr1 and ibr10. Like the previously described ibr3 mutant, which disrupts a putative peroxisomal acyl-CoA oxidase/dehydrogenase, ibr1 and ibr10 display normal IAA responses and defective IBA responses. These defects include reduced root elongation inhibition, decreased lateral root initiation, and reduced IBA-responsive gene expression. However, peroxisomal energy-generating pathways necessary during early seedling development are unaffected in the mutants. Positional cloning of the genes responsible for the mutant defects reveals that IBR1 encodes a member of the short-chain dehydrogenase/reductase family and that IBR10 resembles enoyl-CoA hydratases/isomerases. Both enzymes contain C-terminal peroxisomal-targeting signals, consistent with IBA metabolism occurring in peroxisomes. We present a model in which IBR3, IBR10, and IBR1 may act sequentially in peroxisomal IBA beta-oxidation to IAA.

Journal Article

Abstract  Recent advances in systems biology, omics, and computational studies allow us to carry out data mining for improving biofuel production bioprocesses. Of particular interest are bioprocesses that center on microbial capabilities to biotransform both the hexose and pentose fractions present in crop residues. This called for a systematic exploration of the components of the media to obtain higher-density cultures and more-productive fermentation operations than are currently found. By using a meta-analysis approach of the transcriptional responses to butanol stress, we identified the nutritional requirements of solvent-tolerant strain Clostridium beijerinckii SA-1 (ATCC 35702). The nutritional requirements identified were later validated using the chemostat pulse-and-shift technique. C. beijerinckii SA-1 was cultivated in a two-stage single-feed-stream continuous production system to test the proposed validated medium formulation, and the coutilization of D-glucose and D-xylose was evaluated by taking advantage of the well-known ability of solventogenic clostridia to utilize a large variety of carbon sources such as mono-, oligo-, and polysaccharides containing pentose and hexose sugars. Our results indicated that C. beijerinckii SA-1 was able to coferment hexose/pentose sugar mixtures in the absence of a glucose repression effect. In addition, our analysis suggests that the solvent and acid resistance mechanisms found in this strain are differentially regulated compared to strain NRRL B-527 and are outlined as the basis of the analysis toward optimizing butanol production.

DOI
Journal Article

Abstract  Volatile metabolites from headspace gas of carrot cv. Vita-treat inoculated with water or four different pathogens Botrytis cinerea, Erwinia carotovora subsp. carotovora, Aspergillus niger and Fusarium avenaceum were profiled using gas chromatography and mass spectrometry to develop a technology to discriminate diseases. The inoculation of carrot roots with water or different pathogens released a total of 137 different volatile metabolites. Among them, 39 compounds were relatively consistent and 11 were specific to one or more diseases/inoculations. E. carotovora subsp. carotovora produced seven disease-specific metabolites: 1-butanol, 3-methyl; 1-pentanol; 1-propanol, 2-methyl; 2,3-butanedione; boronic acid, ethyl; butane, 1-methoxy-3-methyl; and ethane, ethoxy. Some metabolites were disease/inoculation discriminatory and were not detected in all treatments: 1,2-dimethoxy-ethene was common in carrots inoculated with E. carotovora subsp. carotovora and B. cinerea, while 2-butanone, 3-chloro-4-hydroxy-1,4-diphenyl was common in carrots inoculated with E. carotovora subsp. carotovora, F. avenaceum and water-inoculated control. The significant mass ions, based on univariate analysis, from a total of 150 (46-195 m/z) and compounds from a total of 32 were further subjected to stepwise discriminant analysis and discriminant analysis. The models for 3 days after inoculation (DAI) were better than those for 6 DAI and 3 + 6 DAI, where up to 90% of the observations were correctly classified into respective inoculations. The disease-discriminatory compounds from different diseases/inoculations and discriminant analysis models developed here have the potential for the early detection and discrimination of postharvest diseases of carrot cv. Vita-treat, after validation under commercial conditions.

Journal Article

Abstract  Previously, we reported that IFN-gamma and TNF-alpha downregulate the expression of the human Na(+)/H(+) exchanger (NHE)3 gene by modulating Sp1/Sp3 transcription factors in C2BBe1 cells. It is reported that butyrate inhibits IFN-gamma and TNF-alpha signaling pathways. In this study, we have investigated the effect of sodium butyrate (NaB) and IFN-gamma/TNF-alpha on human NHE3 promoter activity. In transient transfection studies, NaB (5 mM) led to 10-fold stimulation of NHE3 promoter activity after incubation for 24 h. With 5'-deletion analysis, the NaB-responsive region was mapped to the NHE3 core promoter, bp -95 to + 5, which we had shown previously to confer responsiveness to IFN-gamma/TNF-alpha. The stimulatory effect of NaB on the NHE3 promoter was reduced by 60% in the presence of IFN-gamma/TNF-alpha. Mutually, the repressive effect of these cytokines was attenuated by NaB. Knockdown of Sp1 and Sp3 expression with small interfering RNA (siRNA) resulted in a significant resistance to NaB effects. NaB treatment showed no effect on Sp1 and Sp3 protein expression as assessed by Western blot analyses. Gel mobility shift assays with nuclear proteins from NaB-treated cells showed enhanced binding of Sp1 and Sp3 to the NHE3 promoter. The phosphatase inhibitor okadaic acid (200 nM) blocked the stimulatory effect of NaB on the NHE3 promoter. NaB effects on the NHE3 promoter were significantly attenuated by protein phosphatase (PP)1alpha- and PP2Aalpha-specific siRNA transfection. Our data suggest that the differential regulation of NHE3 gene expression by NaB and IFN-gamma/TNF-alpha is mediated through alternative pathways that converge on Sp1/Sp3.

Journal Article

Abstract  The apple maggot fly, Rhagoletis pomonella, infests several hawthorn species in the southern USA. Here, we tested the hypothesis that these populations could serve as reservoirs for fruit odor discrimination behaviors facilitating sympatric host race formation and speciation, specifically the recent shift from downy hawthorn (Crataegus mollis) to domestic apple (Malus domestica) in the northern USA. Coupled gas chromatography and electroantennographic detection (GC-EAD), gas chromatography with mass spectrometry (GC-MS), and flight tunnel bioassays were used to identify the behaviorally active natal fruit volatile blends for three of the five major southern hawthorns: C. opaca (western mayhaw), C. aestivalis (eastern mayhaw), and C. rufula (a possible hybrid between C. opaca and C. aestivalis). A 6-component blend was developed for C. opaca (3-methylbutan-1-ol [44%], pentyl acetate [6%], butyl butanoate [6%], propyl hexanoate [6%], butyl hexanoate [26%], and hexyl butanoate [12%]); an 8-component blend for C. aestivalis (3-methylbutan-1-ol [2%], butyl acetate [47%], pentyl acetate [2%], butyl butanoate [12%], propyl hexanoate [1%], butyl hexanoate [25%], hexyl butanoate [9%], and pentyl hexanoate [2%]); and a 9-component blend for C. rufula (3-methylbutan-1-ol [1%], butyl acetate [57%], 3-methylbutyl acetate [3%], butyl butanoate [5%], propyl hexanoate [1%], hexyl propionate [1%], butyl hexanoate [23%], hexyl butanoate [6%], and pentyl hexanoate [3%]). Crataegus aestivalis and C. opaca-origin flies showed significantly higher levels of upwind directed flight to their natal blend in flight tunnel assays compared to the non-natal blend and previously developed apple, northern downy hawthorn, and flowering dogwood blends. Eastern and western mayhaw flies also were tested to the C. rufula blend, with eastern flies displaying higher levels of upwind flight compared with the western flies, likely due to the presence of butyl acetate in the C. aestivalis and C. rufula blends, an agonist compound for eastern mayhaw-origin flies, but a behavioral antagonist for western flies. The results discount the possibility that the apple fly was "pre-assembled" and originated via a recent introduction of southern mayhaw flies predisposed to accepting apple. Instead, the findings are consistent with the possibility of southern mayhaw-infesting fly host races. However, mayhaw fruits do emit several volatiles found in apple. It is, therefore, possible that the ability of the fly to evolve a preference for apple volatiles, although not the entire blend, stemmed, in part, from standing variation related to the presence of these compounds in southern mayhaw fruit.

Journal Article

Abstract  BACKGROUND: Predictable and adequate transgene expression is essential for clinical gene therapy. Several studies have focused on optimization of transgene expression. In this study the effect of sodium butyrate (NaB) and a ubiquitous chromatin opening element (UCOE) on short-term gene expression after adenovirus-mediated gene transfer in fibroblastic interface cells from periprosthetic tissue in loosened orthopedic implants is investigated.

METHODS: Cultures of diploid human interface cells from four patients were infected with an adenovirus type-5 vector that carries the luciferase gene driven by the cytomegalovirus (CMV) promoter as a reporter. In addition, viruses with a UCOE were evaluated. Twenty-four hours after infection NaB was added in concentrations of 0 to 9 mM. Luciferase activity was tested after a further 24 h.

RESULTS: NaB in a concentration of 6 mM caused a 7- to 16-fold increase in reporter gene expression compared to control condition. There was no difference in reporter gene expression when cells were infected with Ad.1.5UCOE-CMV.Luc compared to Ad.CMV.Luc. A combination of NaB and a UCOE had no advantage over NaB alone.

CONCLUSIONS: Addition of NaB results in a marked increase in transgene expression in cultured cells. This would allow the enhancement of the expression of the transgene, without requiring a higher vector dose. Butyrate administration could not be substituted by inclusion of UCOEs in the vector. It remains to be established whether the effective concentrations of butyrate can be obtained in vivo.

DOI
Journal Article

Abstract  The population balance model is a useful tool for the design and prediction of a range of processes that involve dispersed phases and particulates. The inverse problem method for the droplet population balance model is applied to estimate coalescences parameters for two-phase liquid-liquid systems. This is undertaken for two systems, namely toluene/water and n-butyl acetate/water in a rotating disc contactor (RDC), using a droplet population balance model. In the literature, the estimation procedure applied to this problem is often based on the deterministic optimization approach. These methods generate instabilities near a local minimum, inevitably requiring information about the derivatives at each iteration. To overcome these limitations, a method providing an estimate for the coalescences parameters is proposed. It is based on a simple and adapted structure of the genetic algorithm, for this particular problem. The agreement between the experimental observations and the simulations is encouraging and, in particular, the models used have proven to be suitable for the prediction of hold-up and Sauter diameter profiles for these systems. Finally, these results demonstrate that the optimization procedure proposed is very convenient for estimating the coalescences parameters for extraction column systems.

Journal Article

Abstract  DL-beta-amino-butyric acid (BABA) has been found to protect potato plants against late blight caused by Phytophthora infestans. This paper compares gene expression profiles of a potato clone harboring horizontal resistance to P. infestans in response to BABA and the pathogen by using cDNA-amplified fragment length polymorphism (cDNA-AFLP), aiming at fudermental elucidation of molecular mechanisms of BABA induced resistance (BABA-IR). In total, 101 transcript derived fragments (TDFs) showed significant differential expression among the treated and their respective control samples. About half of differentially expressed fragments (49) were overlapped in both BABA and P. infestans induction systems, and homology analysis showed that these TDFs in common involved in signaling, cell wall strengthening and synthesis of antimicrobial compounds, reflecting both BABA-IR and the natural resistance shared similar defense mechanisms to a great extent. Analysis of the transcription profiles demonstrated that an early activation of plant basal defense system could be crucial for BABA-IR. Some differentially expressed TDFs homologous to genes encoding proteins related to jasmonic acid-and salicylic acid-dependent signaling pathways, were up-regulated by BABA. Similar genes associated with these pathways were also identified in the pathogen inoculated samples, reinforcing that the extensive cross-talk between BABA-IR and horizontal resistance may be important to coordinate the genes responsible for P. infestans infection in potato.

Journal Article

Abstract  Wheat seedlings (Triticum durum Desf.) were incubated in 100muM Cu(2+) for different periods of time ranging from 1min up to 16h. Following metal addition a rapid intake of copper ions into the roots was observed. Cu(2+) induced an accumulation of both phosphatidic acid and phosphatidylbutanol within 1min of incubation, the latter indicating a very rapid induction of phospholipase D (PLD) activity. The highest PLD stimulation was detected after 2h from copper addition and decreased almost to the initial value at increasing times. Cycloheximide treatment of roots lowered phosphatidylbutanol accumulation because of a reduced PLD activity. The expression profile of a T. durum putative PLD-encoding gene showed a peak after 1h of treatment as well, indicating that enhanced gene expression contributed to the increase in PLD activity. In the absence of copper ions, roots treated with the G protein activator mastoparan showed increases in phosphatidic acid and phosphatidylbutanol similar to those detected with the metal. PLD activity was also stimulated by cholera toxin. Two putatively G protein alpha subunit encoding sequences were isolated and no significant differences in transcription activity following Cu(2+) addition were observed. In copper-treated roots an early production of superoxide generated both by total and membrane-bound NADPH oxidase occurred. The G protein inhibitor suramin as well as the PLD antagonist 1-butanol abolished copper-induced superoxide production.

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Journal Article

Abstract  The non-wine Saccharomyces cerevisiae strain of 96581 was found to be a promising candidate for the production of white wine. It produced wines with fusel alcohols that were 57% higher than those produced by the wine yeasts studied and was also more efficient in the production of 2-phenethyl acetate and 3-methyl-1-butanol acetate. This study also shows that there is a difference in the ester-formation efficiency for acetates relative to C6, C8 and C10 fatty acid esters for all the studied yeast strains. Therefore, it supports the view that other unidentified enzymes besides those regulated by ATF1 and ATF2 genes are involved in the production of ethyl esters of C6-C10 fatty acids. DNA analysis of the 25S, 18S, 5.8S and 5S ribosomal DNA genes in these strains showed high conservation. Despite the closely related nature of these yeast strains, the chemical profiles of the wines produced were significantly different.

Journal Article

Abstract  Reactive oxygen species and redox signaling undergo synergistic and antagonistic interactions with phytohormones to regulate protective responses of plants against biotic and abiotic stresses. However, molecular insight into the nature of this crosstalk remains scarce. We demonstrate that the hydrogen peroxide-responsive UDP-glucosyltransferase UGT74E2 of Arabidopsis thaliana is involved in the modulation of plant architecture and water stress response through its activity toward the auxin indole-3-butyric acid (IBA). Biochemical characterization of recombinant UGT74E2 demonstrated that it strongly favors IBA as a substrate. Assessment of indole-3-acetic acid (IAA), IBA, and their conjugates in transgenic plants ectopically expressing UGT74E2 indicated that the catalytic specificity was maintained in planta. In these transgenic plants, not only were IBA-Glc concentrations increased, but also free IBA levels were elevated and the conjugated IAA pattern was modified. This perturbed IBA and IAA homeostasis was associated with architectural changes, including increased shoot branching and altered rosette shape, and resulted in significantly improved survival during drought and salt stress treatments. Hence, our results reveal that IBA and IBA-Glc are important regulators of morphological and physiological stress adaptation mechanisms and provide molecular evidence for the interplay between hydrogen peroxide and auxin homeostasis through the action of an IBA UGT.

DOI
Journal Article

Abstract  Herein, we fabricated MWCNT-OH adsorbed electrospun nylon 6,6 nanofibers by electrospinning and dip coating method. The amount of MWCNT-OH adsorbed to the pure electrospun nylon 6,6 nanofibers was 0.056 Mt. The electrical conductivity of MWCNT-OH adsorbed electrospun nylon 6,6 nanofibers was 5.24 x 10(-3) S cm(-1). We also investigated the sensing properties of MWCNT-OH adsorbed electrospun nylon 6,6 nanofibers by measuring its response upon exposure to low molecular weight alcohol vapours such as methanol, ethanol, 1-propanol, and 1-butanol. The changes of the electrical resistance of MWCNT-OH adsorbed electrospun nylon 6,6 nanofibers were demonstrated on the basis of hydrogen bonds among the alcohol vapours and hydroxyl groups (-OH) on MWCNT-OH, and amide groups (-NHCO-) in nylon 6,6. The fabricated sensor showed good reversible and reproducible responses upon the cyclic test. (C) 2010 Elsevier B.V. All rights reserved.

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